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SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0740 AM CDT Fri Jun 13 2025 Valid 131300Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon and evening across parts of Montana, extending southward across portions of the central/southern High Plains. The greatest concentration of severe thunderstorms should occur across central/eastern Montana, where large to very large hail, severe winds, and perhaps a few tornadoes are anticipated. ...Northern Rockies/High Plains... A closed upper low will remain centered off the coast of British Columbia today, as multiple low-amplitude mid-level shortwave troughs advance eastward across the Pacific Northwest to the northern Rockies. A seasonably moist low-level airmass is already in place this morning across much of MT, with surface dewpoints generally in the 50s. Daytime heating and modestly steepened mid-level lapse rates will aid in the development of moderate instability by this afternoon, mainly from central MT eastward. 35-50 kt of west-southwesterly mid-level flow associated with the shortwave troughs should support similar values of deep-layer shear, with RAP forecast soundings showing long/straight hodographs at mid/upper levels. Large-scale ascent attendant to the shortwave troughs will likely encourage robust convective development by early afternoon (18-20Z), initially over the higher terrain of the northern Rockies. This activity is forecast to quickly become supercellular given moderate to strong effective bulk shear. The favorable lapse rates and hodographs at mid/upper levels should support a threat for scattered large to isolated very large (2+ inch diameter) hail with this initially cellular activity. By mid to late afternoon into early evening, some clustering/upscale growth is anticipated across eastern MT and vicinity as low-level southeasterly flow gradually strengthens. A greater threat for severe/damaging winds, with isolated gusts of 75+ mph, remains apparent across this area. The tornado threat is less clear, as the boundary layer is forecast to become rather well mixed this afternoon. Still, modestly increasing low-level shear this evening may support some threat for a few tornadoes. ...Central/Southern High Plains into Western Arkansas... Elevated convection ongoing this morning across western OK in a modest low-level warm advection regime may pose a limited severe threat until it diminishes later this morning. Otherwise, at least scattered thunderstorms should develop over the higher terrain of the central Rockies and subsequently spread eastward into the adjacent High Plains this afternoon and evening. Mid-level west-southwesterly flow is generally expected to weaken with southward extent across the central High Plains. But, sufficient directional shear should still exist to support some updraft organization, including the potential for a few supercells across eastern WY/CO into western SD/NE/KS. Isolated large hail will be a threat with any convection that can remain at least semi-discrete, while severe winds may occur with one or more clusters that eventually develop. Convection is expected to become more isolated and less organized with southward extent into the southern High Plains, but it may still pose some hail/wind threat given sufficient instability and steepened low/mid-level lapse rates. Somewhat stronger northwesterly mid-level flow should also be in place across OK into western AR on the back side of an upper trough over the lower/mid MS Valley. While forcing will remain weak/nebulous across this region, a conditionally favorable environment for severe thunderstorms will exist. ...Lower Mississippi Valley/Southeast into the Ohio Valley... A weak mid-level trough will advance slowly eastward from the Ozarks to the lower MS and OH Valleys through the period. Around 25-35 kt of southwesterly mid-level flow will be present over these regions as filtered daytime heating of a rather moist low-level airmass occurs today. Even though lapse rates aloft are forecast to remain poor, sufficient instability and deep-layer shear should exist to support an isolated threat for mainly damaging winds this afternoon and early evening as low-level lapse rates steepen. A Marginal Risk has been included with this update across parts of the lower MS Valley/Southeast into the OH Valley, where confidence in loosely organized clusters occurring is greatest. ..Gleason/Kerr.. 06/13/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0740 AM CDT Fri Jun 13 2025 Valid 131300Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon and evening across parts of Montana, extending southward across portions of the central/southern High Plains. The greatest concentration of severe thunderstorms should occur across central/eastern Montana, where large to very large hail, severe winds, and perhaps a few tornadoes are anticipated. ...Northern Rockies/High Plains... A closed upper low will remain centered off the coast of British Columbia today, as multiple low-amplitude mid-level shortwave troughs advance eastward across the Pacific Northwest to the northern Rockies. A seasonably moist low-level airmass is already in place this morning across much of MT, with surface dewpoints generally in the 50s. Daytime heating and modestly steepened mid-level lapse rates will aid in the development of moderate instability by this afternoon, mainly from central MT eastward. 35-50 kt of west-southwesterly mid-level flow associated with the shortwave troughs should support similar values of deep-layer shear, with RAP forecast soundings showing long/straight hodographs at mid/upper levels. Large-scale ascent attendant to the shortwave troughs will likely encourage robust convective development by early afternoon (18-20Z), initially over the higher terrain of the northern Rockies. This activity is forecast to quickly become supercellular given moderate to strong effective bulk shear. The favorable lapse rates and hodographs at mid/upper levels should support a threat for scattered large to isolated very large (2+ inch diameter) hail with this initially cellular activity. By mid to late afternoon into early evening, some clustering/upscale growth is anticipated across eastern MT and vicinity as low-level southeasterly flow gradually strengthens. A greater threat for severe/damaging winds, with isolated gusts of 75+ mph, remains apparent across this area. The tornado threat is less clear, as the boundary layer is forecast to become rather well mixed this afternoon. Still, modestly increasing low-level shear this evening may support some threat for a few tornadoes. ...Central/Southern High Plains into Western Arkansas... Elevated convection ongoing this morning across western OK in a modest low-level warm advection regime may pose a limited severe threat until it diminishes later this morning. Otherwise, at least scattered thunderstorms should develop over the higher terrain of the central Rockies and subsequently spread eastward into the adjacent High Plains this afternoon and evening. Mid-level west-southwesterly flow is generally expected to weaken with southward extent across the central High Plains. But, sufficient directional shear should still exist to support some updraft organization, including the potential for a few supercells across eastern WY/CO into western SD/NE/KS. Isolated large hail will be a threat with any convection that can remain at least semi-discrete, while severe winds may occur with one or more clusters that eventually develop. Convection is expected to become more isolated and less organized with southward extent into the southern High Plains, but it may still pose some hail/wind threat given sufficient instability and steepened low/mid-level lapse rates. Somewhat stronger northwesterly mid-level flow should also be in place across OK into western AR on the back side of an upper trough over the lower/mid MS Valley. While forcing will remain weak/nebulous across this region, a conditionally favorable environment for severe thunderstorms will exist. ...Lower Mississippi Valley/Southeast into the Ohio Valley... A weak mid-level trough will advance slowly eastward from the Ozarks to the lower MS and OH Valleys through the period. Around 25-35 kt of southwesterly mid-level flow will be present over these regions as filtered daytime heating of a rather moist low-level airmass occurs today. Even though lapse rates aloft are forecast to remain poor, sufficient instability and deep-layer shear should exist to support an isolated threat for mainly damaging winds this afternoon and early evening as low-level lapse rates steepen. A Marginal Risk has been included with this update across parts of the lower MS Valley/Southeast into the OH Valley, where confidence in loosely organized clusters occurring is greatest. ..Gleason/Kerr.. 06/13/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0740 AM CDT Fri Jun 13 2025 Valid 131300Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon and evening across parts of Montana, extending southward across portions of the central/southern High Plains. The greatest concentration of severe thunderstorms should occur across central/eastern Montana, where large to very large hail, severe winds, and perhaps a few tornadoes are anticipated. ...Northern Rockies/High Plains... A closed upper low will remain centered off the coast of British Columbia today, as multiple low-amplitude mid-level shortwave troughs advance eastward across the Pacific Northwest to the northern Rockies. A seasonably moist low-level airmass is already in place this morning across much of MT, with surface dewpoints generally in the 50s. Daytime heating and modestly steepened mid-level lapse rates will aid in the development of moderate instability by this afternoon, mainly from central MT eastward. 35-50 kt of west-southwesterly mid-level flow associated with the shortwave troughs should support similar values of deep-layer shear, with RAP forecast soundings showing long/straight hodographs at mid/upper levels. Large-scale ascent attendant to the shortwave troughs will likely encourage robust convective development by early afternoon (18-20Z), initially over the higher terrain of the northern Rockies. This activity is forecast to quickly become supercellular given moderate to strong effective bulk shear. The favorable lapse rates and hodographs at mid/upper levels should support a threat for scattered large to isolated very large (2+ inch diameter) hail with this initially cellular activity. By mid to late afternoon into early evening, some clustering/upscale growth is anticipated across eastern MT and vicinity as low-level southeasterly flow gradually strengthens. A greater threat for severe/damaging winds, with isolated gusts of 75+ mph, remains apparent across this area. The tornado threat is less clear, as the boundary layer is forecast to become rather well mixed this afternoon. Still, modestly increasing low-level shear this evening may support some threat for a few tornadoes. ...Central/Southern High Plains into Western Arkansas... Elevated convection ongoing this morning across western OK in a modest low-level warm advection regime may pose a limited severe threat until it diminishes later this morning. Otherwise, at least scattered thunderstorms should develop over the higher terrain of the central Rockies and subsequently spread eastward into the adjacent High Plains this afternoon and evening. Mid-level west-southwesterly flow is generally expected to weaken with southward extent across the central High Plains. But, sufficient directional shear should still exist to support some updraft organization, including the potential for a few supercells across eastern WY/CO into western SD/NE/KS. Isolated large hail will be a threat with any convection that can remain at least semi-discrete, while severe winds may occur with one or more clusters that eventually develop. Convection is expected to become more isolated and less organized with southward extent into the southern High Plains, but it may still pose some hail/wind threat given sufficient instability and steepened low/mid-level lapse rates. Somewhat stronger northwesterly mid-level flow should also be in place across OK into western AR on the back side of an upper trough over the lower/mid MS Valley. While forcing will remain weak/nebulous across this region, a conditionally favorable environment for severe thunderstorms will exist. ...Lower Mississippi Valley/Southeast into the Ohio Valley... A weak mid-level trough will advance slowly eastward from the Ozarks to the lower MS and OH Valleys through the period. Around 25-35 kt of southwesterly mid-level flow will be present over these regions as filtered daytime heating of a rather moist low-level airmass occurs today. Even though lapse rates aloft are forecast to remain poor, sufficient instability and deep-layer shear should exist to support an isolated threat for mainly damaging winds this afternoon and early evening as low-level lapse rates steepen. A Marginal Risk has been included with this update across parts of the lower MS Valley/Southeast into the OH Valley, where confidence in loosely organized clusters occurring is greatest. ..Gleason/Kerr.. 06/13/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0740 AM CDT Fri Jun 13 2025 Valid 131300Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon and evening across parts of Montana, extending southward across portions of the central/southern High Plains. The greatest concentration of severe thunderstorms should occur across central/eastern Montana, where large to very large hail, severe winds, and perhaps a few tornadoes are anticipated. ...Northern Rockies/High Plains... A closed upper low will remain centered off the coast of British Columbia today, as multiple low-amplitude mid-level shortwave troughs advance eastward across the Pacific Northwest to the northern Rockies. A seasonably moist low-level airmass is already in place this morning across much of MT, with surface dewpoints generally in the 50s. Daytime heating and modestly steepened mid-level lapse rates will aid in the development of moderate instability by this afternoon, mainly from central MT eastward. 35-50 kt of west-southwesterly mid-level flow associated with the shortwave troughs should support similar values of deep-layer shear, with RAP forecast soundings showing long/straight hodographs at mid/upper levels. Large-scale ascent attendant to the shortwave troughs will likely encourage robust convective development by early afternoon (18-20Z), initially over the higher terrain of the northern Rockies. This activity is forecast to quickly become supercellular given moderate to strong effective bulk shear. The favorable lapse rates and hodographs at mid/upper levels should support a threat for scattered large to isolated very large (2+ inch diameter) hail with this initially cellular activity. By mid to late afternoon into early evening, some clustering/upscale growth is anticipated across eastern MT and vicinity as low-level southeasterly flow gradually strengthens. A greater threat for severe/damaging winds, with isolated gusts of 75+ mph, remains apparent across this area. The tornado threat is less clear, as the boundary layer is forecast to become rather well mixed this afternoon. Still, modestly increasing low-level shear this evening may support some threat for a few tornadoes. ...Central/Southern High Plains into Western Arkansas... Elevated convection ongoing this morning across western OK in a modest low-level warm advection regime may pose a limited severe threat until it diminishes later this morning. Otherwise, at least scattered thunderstorms should develop over the higher terrain of the central Rockies and subsequently spread eastward into the adjacent High Plains this afternoon and evening. Mid-level west-southwesterly flow is generally expected to weaken with southward extent across the central High Plains. But, sufficient directional shear should still exist to support some updraft organization, including the potential for a few supercells across eastern WY/CO into western SD/NE/KS. Isolated large hail will be a threat with any convection that can remain at least semi-discrete, while severe winds may occur with one or more clusters that eventually develop. Convection is expected to become more isolated and less organized with southward extent into the southern High Plains, but it may still pose some hail/wind threat given sufficient instability and steepened low/mid-level lapse rates. Somewhat stronger northwesterly mid-level flow should also be in place across OK into western AR on the back side of an upper trough over the lower/mid MS Valley. While forcing will remain weak/nebulous across this region, a conditionally favorable environment for severe thunderstorms will exist. ...Lower Mississippi Valley/Southeast into the Ohio Valley... A weak mid-level trough will advance slowly eastward from the Ozarks to the lower MS and OH Valleys through the period. Around 25-35 kt of southwesterly mid-level flow will be present over these regions as filtered daytime heating of a rather moist low-level airmass occurs today. Even though lapse rates aloft are forecast to remain poor, sufficient instability and deep-layer shear should exist to support an isolated threat for mainly damaging winds this afternoon and early evening as low-level lapse rates steepen. A Marginal Risk has been included with this update across parts of the lower MS Valley/Southeast into the OH Valley, where confidence in loosely organized clusters occurring is greatest. ..Gleason/Kerr.. 06/13/2025 Read more

5-Day Uncertainty Track last updated Fri, 13 Jun 2025 11:34:20 GMT


Wind Speed Probabilities last updated Fri, 13 Jun 2025 09:21:39 GMT

Issued at 600 AM CST Fri Jun 13 2025 872 WTPZ34 KNHC 131134 TCPEP4 BULLETIN Potential Tropical Cyclone Four-E Intermediate Advisory Number 3A NWS National Hurricane Center Miami FL EP042025 600 AM CST Fri Jun 13 2025 ...DISTURBANCE BECOMING BETTER ORGANIZED AND EXPECTED TO BECOME A TROPICAL STORM LATER TODAY... ...TROPICAL STORM WATCH REMAINS IN EFFECT FOR THE COAST OF SOUTHWESTERN MEXICO... SUMMARY OF 600 AM CST...1200 UTC...INFORMATION ---------------------------------------------- LOCATION...13.4N 101.3W ABOUT 295 MI...475 KM S OF ZIHUATANEJO MEXICO MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H PRESENT MOVEMENT...NNW OR 335 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Watch is in effect for... * Tecpan De Galeana to Manzanillo A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. A Tropical Storm Warning may be required for portions of the watch area later today. The Tropical Storm Watch may need to be extended northward later today. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 600 AM CST (1200 UTC), the disturbance was centered near latitude 13.4 North, longitude 101.3 West. The system is moving toward the north-northwest near 9 mph (15 km/h). A turn toward the northwest is expected later today, with a turn toward the west-northwest forecast by Sunday. On the forecast track, the disturbance is forecast to move parallel to, but offshore of, the southwestern coast of Mexico. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Strengthening is expected during the next couple of days. The system is forecast to become a tropical storm later today and continue strengthening on Saturday as it moves parallel to the coast of southwestern Mexico. * Formation chance through 48 hours...high ...near 100 percent. * Formation chance through 7 days...high...near 100 percent. The estimated minimum central pressure is 1006 mb (29.71 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Potential Tropical Cyclone Four-E can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP4 and WMO header WTPZ44 KNHC. RAINFALL: Rainfall totals of 2 to 4 inches, with localized amounts up to 6 inches, are possible across portions of the Mexican states of Guerrero, Michoacán, and Colima through this weekend. This rainfall may lead to areas of flooding and mudslides. For a complete depiction of forecast rainfall associated with Potential Tropical Cyclone Four-E, please see the National Weather Service Storm Total Rainfall Graphic available at hurricanes.gov/graphics_ep4.shtml?rainqpf WIND: Tropical storm conditions are possible within the watch area on Saturday. SURF: Swells generated by Potential Tropical Cyclone Four-E will affect portions of the coast of southwestern Mexico during the next few days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 900 AM CST. $$ Forecaster Kelly

...DISTURBANCE BECOMING BETTER ORGANIZED AND EXPECTED TO BECOME A TROPICAL STORM LATER TODAY... ...TROPICAL STORM WATCH REMAINS IN EFFECT FOR THE COAST OF SOUTHWESTERN MEXICO... As of 6:00 AM CST Fri Jun 13 the center of Four-E was located near 13.4, -101.3 with movement NNW at 9 mph. The minimum central pressure was 1006 mb with maximum sustained winds of about 35 mph.

000
ABPZ20 KNHC 131118
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Fri Jun 13 2025

For the eastern and central North Pacific east of 180 longitude:

Active Systems:
The National Hurricane Center is issuing advisories on Potential
Tropical Cyclone Four-E, located in the eastern Pacific basin off
the coast of southwestern Mexico.
* Formation chance through 48 hours...high...near 100 percent.
* Formation chance through 7 days...high...near 100 percent.

Offshore of Central America and Southern Mexico:
An area of low pressure is forecast to develop late this weekend or
early next week near the coast of Central America. Environmental
conditions appear conducive for some gradual development of this
system as it moves west-northwestward near the coasts of Central
America and southern Mexico.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...30 percent.

&&
Public Advisories on Potential Tropical Cyclone Four-E are issued
under WMO header WTPZ34 KNHC and under AWIPS header MIATCPEP4.
Forecast/Advisories on Potential Tropical Cyclone Four-E are issued
under WMO header WTPZ24 KNHC and under AWIPS header MIATCMEP4.

$$
Forecaster Gibbs/Kelly

5-Day Uncertainty Track last updated Fri, 13 Jun 2025 08:34:06 GMT


Wind Speed Probabilities last updated Fri, 13 Jun 2025 09:21:39 GMT

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Fri Jun 13 2025 Valid 161200Z - 211200Z ...DISCUSSION... ...Monday/Day 4 to Wednesday/Day 6... A mid-level ridge across the Great Plains is forecast to become less amplified on Monday, as multiple shortwave troughs move through westerly flow across the north-central states. A moist airmass is forecast across much of the central and northern Plains, where moderate to strong instability appears likely to develop by afternoon. Along the northern edge of the stronger instability, scattered convective initiation is expected. The instability, combined with moderate deep-layer shear, should support a severe threat. Large hail and severe wind gusts will be possible during the afternoon and evening. The mid-level ridge is forecast to move eastward into the Missouri Valley on Tuesday, as a trough moves into the Rockies. At the surface, a moist airmass is forecast from the central Plains into the Missouri Valley, where moderate to strong instability appears likely to develop by afternoon. Large-scale ascent ahead of the approaching trough is forecast to move into the central Plains Tuesday evening. As a result, a large area of thunderstorms is forecast to develop from northern Kansas into much of Nebraska. Model forecasts suggest that moderate deep-layer shear will be in place, which would support a large hail and wind-damage threat. The mid-level trough is forecast to move across the Great Plains on Wednesday. A moist airmass is forecast to remain in place to the east of the trough across the lower Missouri and Mississippi Valleys. Ahead of the trough, moderate instability is forecast by afternoon. Thunderstorm development is expected with this unstable airmass from eastern Kansas northeastward into the mid to upper Mississippi Valley. A severe threat will be possible. The greatest potential for severe storms could be from northern Missouri into southern Wisconsin, along and near the axis of a low-level jet. ...Thursday/Day 7 and Friday/Day 8... From Thursday into Friday, the mid-level trough, and an associated cold front, is forecast to move from the mid Mississippi Valley to the Eastern Seaboard. A moist and unstable airmass should be in place ahead of the trough. Thunderstorm development will be possible along parts of the front, and across the warm sector. Although a severe threat may develop as instability increases during the day, the timing of the front remains questionable and predictability is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Fri Jun 13 2025 Valid 161200Z - 211200Z ...DISCUSSION... ...Monday/Day 4 to Wednesday/Day 6... A mid-level ridge across the Great Plains is forecast to become less amplified on Monday, as multiple shortwave troughs move through westerly flow across the north-central states. A moist airmass is forecast across much of the central and northern Plains, where moderate to strong instability appears likely to develop by afternoon. Along the northern edge of the stronger instability, scattered convective initiation is expected. The instability, combined with moderate deep-layer shear, should support a severe threat. Large hail and severe wind gusts will be possible during the afternoon and evening. The mid-level ridge is forecast to move eastward into the Missouri Valley on Tuesday, as a trough moves into the Rockies. At the surface, a moist airmass is forecast from the central Plains into the Missouri Valley, where moderate to strong instability appears likely to develop by afternoon. Large-scale ascent ahead of the approaching trough is forecast to move into the central Plains Tuesday evening. As a result, a large area of thunderstorms is forecast to develop from northern Kansas into much of Nebraska. Model forecasts suggest that moderate deep-layer shear will be in place, which would support a large hail and wind-damage threat. The mid-level trough is forecast to move across the Great Plains on Wednesday. A moist airmass is forecast to remain in place to the east of the trough across the lower Missouri and Mississippi Valleys. Ahead of the trough, moderate instability is forecast by afternoon. Thunderstorm development is expected with this unstable airmass from eastern Kansas northeastward into the mid to upper Mississippi Valley. A severe threat will be possible. The greatest potential for severe storms could be from northern Missouri into southern Wisconsin, along and near the axis of a low-level jet. ...Thursday/Day 7 and Friday/Day 8... From Thursday into Friday, the mid-level trough, and an associated cold front, is forecast to move from the mid Mississippi Valley to the Eastern Seaboard. A moist and unstable airmass should be in place ahead of the trough. Thunderstorm development will be possible along parts of the front, and across the warm sector. Although a severe threat may develop as instability increases during the day, the timing of the front remains questionable and predictability is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Fri Jun 13 2025 Valid 161200Z - 211200Z ...DISCUSSION... ...Monday/Day 4 to Wednesday/Day 6... A mid-level ridge across the Great Plains is forecast to become less amplified on Monday, as multiple shortwave troughs move through westerly flow across the north-central states. A moist airmass is forecast across much of the central and northern Plains, where moderate to strong instability appears likely to develop by afternoon. Along the northern edge of the stronger instability, scattered convective initiation is expected. The instability, combined with moderate deep-layer shear, should support a severe threat. Large hail and severe wind gusts will be possible during the afternoon and evening. The mid-level ridge is forecast to move eastward into the Missouri Valley on Tuesday, as a trough moves into the Rockies. At the surface, a moist airmass is forecast from the central Plains into the Missouri Valley, where moderate to strong instability appears likely to develop by afternoon. Large-scale ascent ahead of the approaching trough is forecast to move into the central Plains Tuesday evening. As a result, a large area of thunderstorms is forecast to develop from northern Kansas into much of Nebraska. Model forecasts suggest that moderate deep-layer shear will be in place, which would support a large hail and wind-damage threat. The mid-level trough is forecast to move across the Great Plains on Wednesday. A moist airmass is forecast to remain in place to the east of the trough across the lower Missouri and Mississippi Valleys. Ahead of the trough, moderate instability is forecast by afternoon. Thunderstorm development is expected with this unstable airmass from eastern Kansas northeastward into the mid to upper Mississippi Valley. A severe threat will be possible. The greatest potential for severe storms could be from northern Missouri into southern Wisconsin, along and near the axis of a low-level jet. ...Thursday/Day 7 and Friday/Day 8... From Thursday into Friday, the mid-level trough, and an associated cold front, is forecast to move from the mid Mississippi Valley to the Eastern Seaboard. A moist and unstable airmass should be in place ahead of the trough. Thunderstorm development will be possible along parts of the front, and across the warm sector. Although a severe threat may develop as instability increases during the day, the timing of the front remains questionable and predictability is low. Read more

5-Day Uncertainty Track last updated Fri, 13 Jun 2025 08:34:06 GMT


Wind Speed Probabilities last updated Fri, 13 Jun 2025 08:34:06 GMT

5-Day Uncertainty Track last updated Fri, 13 Jun 2025 08:34:06 GMT


Wind Speed Probabilities last updated Fri, 13 Jun 2025 08:34:06 GMT

Issued at 0900 UTC FRI JUN 13 2025 533 FOPZ14 KNHC 130832 PWSEP4 POTENTIAL TROPICAL CYCLONE FOUR-E WIND SPEED PROBABILITIES NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042025 0900 UTC FRI JUN 13 2025 AT 0900Z THE CENTER OF POTENTIAL TROPICAL CYCLONE FOUR-E WAS LOCATED NEAR LATITUDE 12.8 NORTH...LONGITUDE 100.8 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 30 KTS...35 MPH...55 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) PACIFIC DAYLIGHT TIME (PDT)...SUBTRACT 7 HOURS FROM Z TIME HAWAIIAN STANDARD TIME (HST)...SUBTRACT 10 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 06Z FRI AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 06Z FRI 18Z FRI 06Z SAT 18Z SAT 06Z SUN 06Z MON 06Z TUE PERIODS TO TO TO TO TO TO TO 18Z FRI 06Z SAT 18Z SAT 06Z SUN 06Z MON 06Z TUE 06Z WED FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT ISLAS MARIAS 34 X X( X) X( X) 2( 2) 1( 3) X( 3) X( 3) 15N 105W 34 X 4( 4) 28(32) 5(37) X(37) X(37) X(37) 15N 105W 50 X X( X) 5( 5) 1( 6) X( 6) X( 6) X( 6) MANZANILLO 34 X 1( 1) 2( 3) 5( 8) X( 8) X( 8) X( 8) L CARDENAS 34 X 1( 1) 3( 4) 1( 5) 1( 6) X( 6) X( 6) ZIHUATANEJO 34 X 1( 1) 3( 4) 1( 5) X( 5) X( 5) X( 5) 15N 100W 34 1 1( 2) 1( 3) X( 3) X( 3) X( 3) X( 3) 15N 110W 34 X X( X) X( X) 3( 3) 2( 5) X( 5) X( 5) 20N 110W 34 X X( X) X( X) 1( 1) 6( 7) X( 7) X( 7) ISLA SOCORRO 34 X X( X) X( X) 1( 1) 17(18) 4(22) X(22) ISLA SOCORRO 50 X X( X) X( X) X( X) 3( 3) 1( 4) X( 4) ISLA CLARION 34 X X( X) X( X) X( X) 1( 1) 5( 6) X( 6) $$ FORECASTER BEVEN

Issued at 300 AM CST Fri Jun 13 2025 372 WTPZ44 KNHC 130832 TCDEP4 Potential Tropical Cyclone Four-E Discussion Number 3 NWS National Hurricane Center Miami FL EP042025 300 AM CST Fri Jun 13 2025 Satellite imagery and scatterometer data indicate that the disturbance is gradually becoming better organized, with the convective banding increasing and the circulation becoming better defined. However, the system does not yet have either enough organized convection or a sufficiently well-defined circulation to be considered a tropical cyclone. The scatterometer data showed 25-30 kt winds about 120 n mi south and southeast of the center, so the initial intensity remains 30 kt. The initial motion is a somewhat uncertain 335/8 kt. Satellite imagery shows that the depression is currently south of a mid- to upper-level trough over Texas and northern Mexico and southeast of a mid- to upper-level ridge over Baja California and the adjacent Pacific. The dynamical models forecast that the trough will weaken and move eastward during the next 2-3 days, with the ridge building eastward to the north of the system. This evolution should cause the disturbance to turn northwestward later today, followed by a west-northwestward and westward motion later in the forecast period. The forecast guidance is in good agreement with this scenario, and the new forecast track is close to the various consensus models and just a little north of the previous track. There is a possibility of erratic motion today as the system gets better organized, and this may affect how close the system will come to the coast of Mexico. The forecast track keeps the system over warm sea surface temperatures for the next 36-48 h. However, a combination of the broad structure and moderate easterly vertical wind shear is likely to slow the development. The new intensity guidance is a little lower than for the previous forecast, and the forecast peak intensity of 60 kt is near the high end of the guidance envelope. After 48 h, cooler waters and drier mid-level air will lead to steady weakening, and the system is forecast to dissipate by 120 h. KEY MESSAGES: 1. The outer bands of Potential Tropical Cyclone Four-E may bring locally heavy rainfall to the Mexican states of Guerrero, Michoacán, and Colima through this weekend. Isolated flooding and mudslides, especially in areas of steep terrain, are possible. 2. The disturbance is forecast to be at tropical storm strength when it moves near the southwestern coast of Mexico on Saturday. Tropical storm conditions are possible over portions of that area. FORECAST POSITIONS AND MAX WINDS INIT 13/0900Z 12.8N 100.8W 30 KT 35 MPH...POTENTIAL TROP CYCLONE 12H 13/1800Z 13.7N 101.5W 35 KT 40 MPH...TROPICAL CYCLONE 24H 14/0600Z 14.9N 103.0W 45 KT 50 MPH 36H 14/1800Z 16.0N 104.6W 55 KT 65 MPH 48H 15/0600Z 16.9N 106.5W 60 KT 70 MPH 60H 15/1800Z 17.4N 108.6W 50 KT 60 MPH 72H 16/0600Z 17.6N 110.5W 40 KT 45 MPH 96H 17/0600Z 18.0N 114.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 18/0600Z...DISSIPATED $$ Forecaster Beven

...DISTURBANCE EXPECTED TO BECOME A TROPICAL STORM LATER TODAY... ...TROPICAL STORM WATCH REMAINS IN EFFECT FOR THE COAST OF SOUTHWESTERN MEXICO... As of 3:00 AM CST Fri Jun 13 the center of Four-E was located near 12.8, -100.8 with movement NNW at 9 mph. The minimum central pressure was 1006 mb with maximum sustained winds of about 35 mph.

Issued at 300 AM CST Fri Jun 13 2025 250 WTPZ34 KNHC 130832 TCPEP4 BULLETIN Potential Tropical Cyclone Four-E Advisory Number 3 NWS National Hurricane Center Miami FL EP042025 300 AM CST Fri Jun 13 2025 ...DISTURBANCE EXPECTED TO BECOME A TROPICAL STORM LATER TODAY... ...TROPICAL STORM WATCH REMAINS IN EFFECT FOR THE COAST OF SOUTHWESTERN MEXICO... SUMMARY OF 300 AM CST...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...12.8N 100.8W ABOUT 340 MI...550 KM S OF ZIHUATANEJO MEXICO MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H PRESENT MOVEMENT...NNW OR 335 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Watch is in effect for... * Tecpan De Galeana to Manzanillo A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. A Tropical Storm Warning may be required for portions of the watch area later today. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 300 AM CST (0900 UTC), the disturbance was centered near latitude 12.8 North, longitude 100.8 West. The system is moving toward the north-northwest near 9 mph (15 km/h). A turn toward the northwest is expected later today, with a turn toward the west-northwest forecast by Sunday. On the forecast track, the disturbance is forecast to move parallel to, but offshore of, the southwestern coast of Mexico. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Strengthening is expected during the next couple of days. The system is forecast to become a tropical storm later today and continue strengthening on Saturday as it moves parallel to the coast of southwestern Mexico. * Formation chance through 48 hours...high...90 percent. * Formation chance through 7 days...high...90 percent. The estimated minimum central pressure is 1006 mb (29.71 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Potential Tropical Cyclone Four-E can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP4 and WMO header WTPZ44 KNHC. RAINFALL: Rainfall totals of 2 to 4 inches, with localized amounts up to 6 inches, are possible across portions of the Mexican states of Guerrero, Michoacán, and Colima through this weekend. This rainfall may lead to areas of flooding and mudslides. For a complete depiction of forecast rainfall associated with Potential Tropical Cyclone Four-E, please see the National Weather Service Storm Total Rainfall Graphic available at hurricanes.gov/graphics_ep4.shtml?rainqpf WIND: Tropical storm conditions are possible within the watch area on Saturday. SURF: Swells generated by Potential Tropical Cyclone Four-E will affect portions of the coast of southwestern Mexico during the next few days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 600 AM CST. Next complete advisory at 900 AM CST. $$ Forecaster Beven

...DISTURBANCE EXPECTED TO BECOME A TROPICAL STORM LATER TODAY... ...TROPICAL STORM WATCH REMAINS IN EFFECT FOR THE COAST OF SOUTHWESTERN MEXICO... As of 09:00 UTC FRI JUN 13 2025 the center of Four-E was located near 12.8, -100.8 with movement NNW at 9 mph. The minimum central pressure was 1006 mb with maximum sustained winds of about 35 mph.

Issued at 0900 UTC FRI JUN 13 2025 000 WTPZ24 KNHC 130831 TCMEP4 POTENTIAL TROPICAL CYCLONE FOUR-E FORECAST/ADVISORY NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042025 0900 UTC FRI JUN 13 2025 POTENTIAL TROP CYCLONE CENTER LOCATED NEAR 12.8N 100.8W AT 13/0900Z POSITION ACCURATE WITHIN 40 NM PRESENT MOVEMENT TOWARD THE NORTH-NORTHWEST OR 335 DEGREES AT 8 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1006 MB MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 12.8N 100.8W AT 13/0900Z AT 13/0600Z CENTER WAS LOCATED NEAR 12.3N 100.6W FORECAST VALID 13/1800Z 13.7N 101.5W...TROPICAL CYCLONE MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 60NE 80SE 60SW 0NW. FORECAST VALID 14/0600Z 14.9N 103.0W MAX WIND 45 KT...GUSTS 55 KT. 34 KT...100NE 120SE 120SW 70NW. FORECAST VALID 14/1800Z 16.0N 104.6W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 30NE 30SE 20SW 20NW. 34 KT...140NE 140SE 120SW 100NW. FORECAST VALID 15/0600Z 16.9N 106.5W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 30NE 40SE 30SW 20NW. 34 KT...130NE 110SE 100SW 100NW. FORECAST VALID 15/1800Z 17.4N 108.6W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 30NE 20SE 0SW 20NW. 34 KT...100NE 70SE 60SW 70NW. FORECAST VALID 16/0600Z 17.6N 110.5W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 60NE 40SE 40SW 50NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 100 NM ON DAY 4 AND 125 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 17/0600Z 18.0N 114.0W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. OUTLOOK VALID 18/0600Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 12.8N 100.8W INTERMEDIATE PUBLIC ADVISORY...WTNT34 KNHC/MIATCPEP4...AT 13/1200Z NEXT ADVISORY AT 13/1500Z $$ FORECASTER BEVEN