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SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0448 PM CDT Thu Jun 12 2025 Valid 141200Z - 201200Z Strong flow aloft over much of the western CONUS is expected through the forecast period as sub-tropical ridging shifts eastward. This will favor dry surface conditions and increasingly strong wind fields across the Great Basin and lee of the Cascades. Additionally, isolated thunderstorms are possible through this weekend and into next week. Fire-weather conditions are expected to increase through next week. ...Northwest and Great Basin... Westerly mid-level flow will continue over the Northwest and Great Basin this weekend and much of next week. Dry downslope winds are likely D3/Saturday atop drying fuels. With westerly downslope flow of 15-20 mph overlapped with RH below 20%, elevated fire-weather conditions are likely in the lee of the Sierra and through the western Columbia Basin. Some localized threat may persist in the lee of the Sierra and Cascade Gaps D4/Sunday. The strongest winds aloft are likely to coincide with the passage of several stronger embedded shortwaves passing through next week. The most significant of these appears to be D5/Monday. More widespread winds of 20-30 mph with RH below 20% are likely across the western and central Great Basin. However, fuels farther south are less receptive. This casts some uncertainty on how widespread fire-weather concerns will be early next week. Still, enhanced mid-level flow and favorable fire-weather pattern will likely continue through the remainder of the extended forecast period. ...Dry Thunderstorms... Continued troughing over the West will support isolated thunderstorm chances late this weekend and into early next week across the northern Great Basin and Northwest. Weak inland transport of mid-level Pacific moisture should support weak buoyancy with very dry surface conditions. Isolated lightning and a few drier storms are possible, especially D5/Monday and D6/Tuesday. Thereafter, more wetting rainfall appears likely across the Northwest as a cold front approaches. ..Lyons.. 06/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0448 PM CDT Thu Jun 12 2025 Valid 141200Z - 201200Z Strong flow aloft over much of the western CONUS is expected through the forecast period as sub-tropical ridging shifts eastward. This will favor dry surface conditions and increasingly strong wind fields across the Great Basin and lee of the Cascades. Additionally, isolated thunderstorms are possible through this weekend and into next week. Fire-weather conditions are expected to increase through next week. ...Northwest and Great Basin... Westerly mid-level flow will continue over the Northwest and Great Basin this weekend and much of next week. Dry downslope winds are likely D3/Saturday atop drying fuels. With westerly downslope flow of 15-20 mph overlapped with RH below 20%, elevated fire-weather conditions are likely in the lee of the Sierra and through the western Columbia Basin. Some localized threat may persist in the lee of the Sierra and Cascade Gaps D4/Sunday. The strongest winds aloft are likely to coincide with the passage of several stronger embedded shortwaves passing through next week. The most significant of these appears to be D5/Monday. More widespread winds of 20-30 mph with RH below 20% are likely across the western and central Great Basin. However, fuels farther south are less receptive. This casts some uncertainty on how widespread fire-weather concerns will be early next week. Still, enhanced mid-level flow and favorable fire-weather pattern will likely continue through the remainder of the extended forecast period. ...Dry Thunderstorms... Continued troughing over the West will support isolated thunderstorm chances late this weekend and into early next week across the northern Great Basin and Northwest. Weak inland transport of mid-level Pacific moisture should support weak buoyancy with very dry surface conditions. Isolated lightning and a few drier storms are possible, especially D5/Monday and D6/Tuesday. Thereafter, more wetting rainfall appears likely across the Northwest as a cold front approaches. ..Lyons.. 06/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0448 PM CDT Thu Jun 12 2025 Valid 141200Z - 201200Z Strong flow aloft over much of the western CONUS is expected through the forecast period as sub-tropical ridging shifts eastward. This will favor dry surface conditions and increasingly strong wind fields across the Great Basin and lee of the Cascades. Additionally, isolated thunderstorms are possible through this weekend and into next week. Fire-weather conditions are expected to increase through next week. ...Northwest and Great Basin... Westerly mid-level flow will continue over the Northwest and Great Basin this weekend and much of next week. Dry downslope winds are likely D3/Saturday atop drying fuels. With westerly downslope flow of 15-20 mph overlapped with RH below 20%, elevated fire-weather conditions are likely in the lee of the Sierra and through the western Columbia Basin. Some localized threat may persist in the lee of the Sierra and Cascade Gaps D4/Sunday. The strongest winds aloft are likely to coincide with the passage of several stronger embedded shortwaves passing through next week. The most significant of these appears to be D5/Monday. More widespread winds of 20-30 mph with RH below 20% are likely across the western and central Great Basin. However, fuels farther south are less receptive. This casts some uncertainty on how widespread fire-weather concerns will be early next week. Still, enhanced mid-level flow and favorable fire-weather pattern will likely continue through the remainder of the extended forecast period. ...Dry Thunderstorms... Continued troughing over the West will support isolated thunderstorm chances late this weekend and into early next week across the northern Great Basin and Northwest. Weak inland transport of mid-level Pacific moisture should support weak buoyancy with very dry surface conditions. Isolated lightning and a few drier storms are possible, especially D5/Monday and D6/Tuesday. Thereafter, more wetting rainfall appears likely across the Northwest as a cold front approaches. ..Lyons.. 06/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0448 PM CDT Thu Jun 12 2025 Valid 141200Z - 201200Z Strong flow aloft over much of the western CONUS is expected through the forecast period as sub-tropical ridging shifts eastward. This will favor dry surface conditions and increasingly strong wind fields across the Great Basin and lee of the Cascades. Additionally, isolated thunderstorms are possible through this weekend and into next week. Fire-weather conditions are expected to increase through next week. ...Northwest and Great Basin... Westerly mid-level flow will continue over the Northwest and Great Basin this weekend and much of next week. Dry downslope winds are likely D3/Saturday atop drying fuels. With westerly downslope flow of 15-20 mph overlapped with RH below 20%, elevated fire-weather conditions are likely in the lee of the Sierra and through the western Columbia Basin. Some localized threat may persist in the lee of the Sierra and Cascade Gaps D4/Sunday. The strongest winds aloft are likely to coincide with the passage of several stronger embedded shortwaves passing through next week. The most significant of these appears to be D5/Monday. More widespread winds of 20-30 mph with RH below 20% are likely across the western and central Great Basin. However, fuels farther south are less receptive. This casts some uncertainty on how widespread fire-weather concerns will be early next week. Still, enhanced mid-level flow and favorable fire-weather pattern will likely continue through the remainder of the extended forecast period. ...Dry Thunderstorms... Continued troughing over the West will support isolated thunderstorm chances late this weekend and into early next week across the northern Great Basin and Northwest. Weak inland transport of mid-level Pacific moisture should support weak buoyancy with very dry surface conditions. Isolated lightning and a few drier storms are possible, especially D5/Monday and D6/Tuesday. Thereafter, more wetting rainfall appears likely across the Northwest as a cold front approaches. ..Lyons.. 06/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0448 PM CDT Thu Jun 12 2025 Valid 141200Z - 201200Z Strong flow aloft over much of the western CONUS is expected through the forecast period as sub-tropical ridging shifts eastward. This will favor dry surface conditions and increasingly strong wind fields across the Great Basin and lee of the Cascades. Additionally, isolated thunderstorms are possible through this weekend and into next week. Fire-weather conditions are expected to increase through next week. ...Northwest and Great Basin... Westerly mid-level flow will continue over the Northwest and Great Basin this weekend and much of next week. Dry downslope winds are likely D3/Saturday atop drying fuels. With westerly downslope flow of 15-20 mph overlapped with RH below 20%, elevated fire-weather conditions are likely in the lee of the Sierra and through the western Columbia Basin. Some localized threat may persist in the lee of the Sierra and Cascade Gaps D4/Sunday. The strongest winds aloft are likely to coincide with the passage of several stronger embedded shortwaves passing through next week. The most significant of these appears to be D5/Monday. More widespread winds of 20-30 mph with RH below 20% are likely across the western and central Great Basin. However, fuels farther south are less receptive. This casts some uncertainty on how widespread fire-weather concerns will be early next week. Still, enhanced mid-level flow and favorable fire-weather pattern will likely continue through the remainder of the extended forecast period. ...Dry Thunderstorms... Continued troughing over the West will support isolated thunderstorm chances late this weekend and into early next week across the northern Great Basin and Northwest. Weak inland transport of mid-level Pacific moisture should support weak buoyancy with very dry surface conditions. Isolated lightning and a few drier storms are possible, especially D5/Monday and D6/Tuesday. Thereafter, more wetting rainfall appears likely across the Northwest as a cold front approaches. ..Lyons.. 06/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0448 PM CDT Thu Jun 12 2025 Valid 141200Z - 201200Z Strong flow aloft over much of the western CONUS is expected through the forecast period as sub-tropical ridging shifts eastward. This will favor dry surface conditions and increasingly strong wind fields across the Great Basin and lee of the Cascades. Additionally, isolated thunderstorms are possible through this weekend and into next week. Fire-weather conditions are expected to increase through next week. ...Northwest and Great Basin... Westerly mid-level flow will continue over the Northwest and Great Basin this weekend and much of next week. Dry downslope winds are likely D3/Saturday atop drying fuels. With westerly downslope flow of 15-20 mph overlapped with RH below 20%, elevated fire-weather conditions are likely in the lee of the Sierra and through the western Columbia Basin. Some localized threat may persist in the lee of the Sierra and Cascade Gaps D4/Sunday. The strongest winds aloft are likely to coincide with the passage of several stronger embedded shortwaves passing through next week. The most significant of these appears to be D5/Monday. More widespread winds of 20-30 mph with RH below 20% are likely across the western and central Great Basin. However, fuels farther south are less receptive. This casts some uncertainty on how widespread fire-weather concerns will be early next week. Still, enhanced mid-level flow and favorable fire-weather pattern will likely continue through the remainder of the extended forecast period. ...Dry Thunderstorms... Continued troughing over the West will support isolated thunderstorm chances late this weekend and into early next week across the northern Great Basin and Northwest. Weak inland transport of mid-level Pacific moisture should support weak buoyancy with very dry surface conditions. Isolated lightning and a few drier storms are possible, especially D5/Monday and D6/Tuesday. Thereafter, more wetting rainfall appears likely across the Northwest as a cold front approaches. ..Lyons.. 06/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0448 PM CDT Thu Jun 12 2025 Valid 141200Z - 201200Z Strong flow aloft over much of the western CONUS is expected through the forecast period as sub-tropical ridging shifts eastward. This will favor dry surface conditions and increasingly strong wind fields across the Great Basin and lee of the Cascades. Additionally, isolated thunderstorms are possible through this weekend and into next week. Fire-weather conditions are expected to increase through next week. ...Northwest and Great Basin... Westerly mid-level flow will continue over the Northwest and Great Basin this weekend and much of next week. Dry downslope winds are likely D3/Saturday atop drying fuels. With westerly downslope flow of 15-20 mph overlapped with RH below 20%, elevated fire-weather conditions are likely in the lee of the Sierra and through the western Columbia Basin. Some localized threat may persist in the lee of the Sierra and Cascade Gaps D4/Sunday. The strongest winds aloft are likely to coincide with the passage of several stronger embedded shortwaves passing through next week. The most significant of these appears to be D5/Monday. More widespread winds of 20-30 mph with RH below 20% are likely across the western and central Great Basin. However, fuels farther south are less receptive. This casts some uncertainty on how widespread fire-weather concerns will be early next week. Still, enhanced mid-level flow and favorable fire-weather pattern will likely continue through the remainder of the extended forecast period. ...Dry Thunderstorms... Continued troughing over the West will support isolated thunderstorm chances late this weekend and into early next week across the northern Great Basin and Northwest. Weak inland transport of mid-level Pacific moisture should support weak buoyancy with very dry surface conditions. Isolated lightning and a few drier storms are possible, especially D5/Monday and D6/Tuesday. Thereafter, more wetting rainfall appears likely across the Northwest as a cold front approaches. ..Lyons.. 06/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

5-Day Uncertainty Track last updated Thu, 12 Jun 2025 20:45:45 GMT


Wind Speed Probabilities last updated Thu, 12 Jun 2025 21:22:02 GMT

MD 1263 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF DEEP SOUTH TEXAS
Mesoscale Discussion 1263 NWS Storm Prediction Center Norman OK 0345 PM CDT Thu Jun 12 2025 Areas affected...portions of deep south Texas Concerning...Severe potential...Watch unlikely Valid 122045Z - 122145Z Probability of Watch Issuance...5 percent SUMMARY...Marginal risk for severe wind through the afternoon. DISCUSSION...A broken line of storms continues across deep south Texas, producing occasional gusts 40-50 mph. Outflow has largely moved out ahead of the storms on the western flank. However, portions of the line moving through Corpus Christi appear to be more aligned with the outflow. This will gradually shift offshore in the next hour. Agitated cumulus can be seen on visible in the vicinity of the southward moving outflow. Additional storms my develop along the boundary with potential for gusty winds. Overall, the temporal and limited spatial area of the threat will preclude the need for watch issuance. ..Thornton/Guyer.. 06/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CRP...BRO... LAT...LON 26439883 27659911 28169848 28229750 28119716 27759721 27239738 27039739 26789736 26459750 26249769 26169794 26199823 26379882 26439883 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

WW 0410 Status Updates
STATUS REPORT ON WW 410 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..DEAN..06/12/25 ATTN...WFO...BOU...LBF...CYS...FSD...ABR...UNR... STATUS REPORT FOR WS 410 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC075-087-095-115-123-122240- CO . COLORADO COUNTIES INCLUDED ARE LOGAN MORGAN PHILLIPS SEDGWICK WELD NEC005-007-013-017-029-031-033-045-049-069-075-091-101-103-105- 117-123-135-157-161-165-171-122240- NE . NEBRASKA COUNTIES INCLUDED ARE ARTHUR BANNER BOX BUTTE BROWN CHASE CHERRY CHEYENNE DAWES DEUEL GARDEN GRANT HOOKER KEITH KEYA PAHA KIMBALL MCPHERSON MORRILL PERKINS SCOTTS BLUFF SHERIDAN SIOUX THOMAS SDC003-015-017-023-053-073-085-095-121-123-122240- Read more

WW 0410 Status Updates
STATUS REPORT ON WW 410 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..DEAN..06/12/25 ATTN...WFO...BOU...LBF...CYS...FSD...ABR...UNR... STATUS REPORT FOR WS 410 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC075-087-095-115-123-122240- CO . COLORADO COUNTIES INCLUDED ARE LOGAN MORGAN PHILLIPS SEDGWICK WELD NEC005-007-013-017-029-031-033-045-049-069-075-091-101-103-105- 117-123-135-157-161-165-171-122240- NE . NEBRASKA COUNTIES INCLUDED ARE ARTHUR BANNER BOX BUTTE BROWN CHASE CHERRY CHEYENNE DAWES DEUEL GARDEN GRANT HOOKER KEITH KEYA PAHA KIMBALL MCPHERSON MORRILL PERKINS SCOTTS BLUFF SHERIDAN SIOUX THOMAS SDC003-015-017-023-053-073-085-095-121-123-122240- Read more

WW 0410 Status Updates
STATUS REPORT ON WW 410 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..DEAN..06/12/25 ATTN...WFO...BOU...LBF...CYS...FSD...ABR...UNR... STATUS REPORT FOR WS 410 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC075-087-095-115-123-122240- CO . COLORADO COUNTIES INCLUDED ARE LOGAN MORGAN PHILLIPS SEDGWICK WELD NEC005-007-013-017-029-031-033-045-049-069-075-091-101-103-105- 117-123-135-157-161-165-171-122240- NE . NEBRASKA COUNTIES INCLUDED ARE ARTHUR BANNER BOX BUTTE BROWN CHASE CHERRY CHEYENNE DAWES DEUEL GARDEN GRANT HOOKER KEITH KEYA PAHA KIMBALL MCPHERSON MORRILL PERKINS SCOTTS BLUFF SHERIDAN SIOUX THOMAS SDC003-015-017-023-053-073-085-095-121-123-122240- Read more

WW 410 SEVERE TSTM CO NE SD WY 122055Z - 130500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 410 NWS Storm Prediction Center Norman OK 255 PM MDT Thu Jun 12 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Colorado Western and Northern Nebraska Southern South Dakota Southeast Wyoming * Effective this Thursday afternoon and evening from 255 PM until 1100 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible Scattered damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...Severe thunderstorms are expected to continue to develop regionally mainly near a southwest/northeast-oriented front, with an unstable air mass and moderately strong wind profiles supporting supercells and hail/wind potential, and possibly even a brief tornado. The severe thunderstorm watch area is approximately along and 75 statute miles north and south of a line from 40 miles east southeast of Chamberlain SD to 75 miles south southwest of Torrington WY. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 26025. ...Guyer Read more

5-Day Uncertainty Track last updated Thu, 12 Jun 2025 20:45:45 GMT


Wind Speed Probabilities last updated Thu, 12 Jun 2025 21:22:02 GMT

WW 0410 Status Updates
STATUS FOR WATCH 0410 HAS NOT BEEN ISSUED YET Read more

No watches are valid as of Thu Jun 12 20:48:01 UTC 2025.

5-Day Uncertainty Track last updated Thu, 12 Jun 2025 20:45:45 GMT


Wind Speed Probabilities last updated Thu, 12 Jun 2025 20:45:45 GMT

Issued at 2100 UTC THU JUN 12 2025 384 FOPZ14 KNHC 122044 PWSEP4 POTENTIAL TROPICAL CYCLONE FOUR-E WIND SPEED PROBABILITIES NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042025 2100 UTC THU JUN 12 2025 AT 2100Z THE CENTER OF POTENTIAL TROPICAL CYCLONE FOUR-E WAS LOCATED NEAR LATITUDE 11.3 NORTH...LONGITUDE 100.2 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 18Z THU 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 18Z THU 06Z FRI 18Z FRI 06Z SAT 18Z SAT 18Z SUN 18Z MON PERIODS TO TO TO TO TO TO TO 06Z FRI 18Z FRI 06Z SAT 18Z SAT 18Z SUN 18Z MON 18Z TUE FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT ISLAS MARIAS 34 X X( X) X( X) X( X) 2( 2) 1( 3) X( 3) 15N 105W 34 X 1( 1) 7( 8) 34(42) 10(52) X(52) X(52) 15N 105W 50 X X( X) X( X) 8( 8) 6(14) X(14) X(14) 15N 105W 64 X X( X) X( X) 2( 2) 2( 4) X( 4) X( 4) MANZANILLO 34 X X( X) 1( 1) 2( 3) 5( 8) X( 8) X( 8) L CARDENAS 34 X X( X) 3( 3) 4( 7) 2( 9) X( 9) X( 9) ZIHUATANEJO 34 X 1( 1) 2( 3) 3( 6) 1( 7) X( 7) X( 7) 15N 100W 34 X 4( 4) 5( 9) 1(10) X(10) X(10) X(10) ACAPULCO 34 X 1( 1) 2( 3) 1( 4) 1( 5) X( 5) X( 5) P MALDONADO 34 X 1( 1) 1( 2) 1( 3) X( 3) X( 3) X( 3) 15N 110W 34 X X( X) X( X) X( X) 5( 5) 2( 7) X( 7) 20N 110W 34 X X( X) X( X) X( X) 4( 4) 2( 6) X( 6) ISLA SOCORRO 34 X X( X) X( X) X( X) 6( 6) 10(16) X(16) $$ FORECASTER KELLY

Issued at 300 PM CST Thu Jun 12 2025 661 WTPZ44 KNHC 122044 TCDEP4 Potential Tropical Cyclone Four-E Discussion Number 1 NWS National Hurricane Center Miami FL EP042025 300 PM CST Thu Jun 12 2025 Showers and thunderstorms associated with an area of low pressure located south of Mexico, that the National Hurricane Center has been monitoring have increased and are showing signs of organization. While some mid-level rotation is evident in visible satellite images near the northeast edge of ongoing convection, the low-level circulation remains broad and elongated. However, the system is expected to become a tropical storm tonight or tomorrow, and it is possible that it will bring tropical storm conditions to land areas within the next 36 to 48 hours. Therefore, the National Hurricane Center is initiating Potential Tropical Cyclone advisories for this disturbance. The initial motion is more uncertain than normal since the system is still in the formative stage, but the best estimate is west-northwestward at about 6 kt. A northwestward to west-northwestward motion is anticipated during the next few days as the system moves parallel to the coast of southwestern Mexico, being steered by a mid-level ridge. Model guidance is in fairly good agreement with the overall track evolution, although minor track shifts may cause greater impacts to the coast of Mexico. The NHC forecast lies near the simple consensus aids. Since the disturbance currently lacks a well-defined center, users are reminded that the track forecast uncertainty is typically larger in these situations, and future track adjustments may be required. The models suggest a more well-defined center should develop overnight or tomorrow. Once the system becomes better organized and develops an inner core, the environmental conditions appear favorable for strengthening during the next couple of days, with warm sea surface temperatures and abundant moisture. However, the system will be dealing with some easterly to northeasterly wind shear. The NHC forecast shows steady strengthening over the next few days, although there are some guidance aids such as HCCA and the hurricane regional models that lie above the current NHC forecast. Given some uncertainty in how quickly the system consolidates and the limiting wind shear, the NHC forecast lies near the simple intensity consensus aids. Beyond day 4, environmental conditions will become hostile which should lead to weakening, and the system should struggle to produce convection moving into cooler SSTs and a more stable air mass. The current NHC forecast has the system becoming a remnant low at that time, and calls for dissipation by day 5. Based on the NHC forecast, Tropical Storm Watches have been issued for portions of southwestern Mexico. KEY MESSAGES: 1. The outer bands of Potential Tropical Cyclone Four-E may bring locally heavy rainfall to the Mexican states of Guerrero, Michoacan, 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 12/2100Z 11.3N 100.2W 30 KT 35 MPH...POTENTIAL TROP CYCLONE 12H 13/0600Z 12.0N 100.4W 35 KT 40 MPH...TROPICAL CYCLONE 24H 13/1800Z 13.3N 101.3W 45 KT 50 MPH 36H 14/0600Z 14.3N 102.7W 55 KT 65 MPH 48H 14/1800Z 15.5N 104.3W 60 KT 70 MPH 60H 15/0600Z 16.5N 106.2W 60 KT 70 MPH 72H 15/1800Z 17.1N 108.2W 50 KT 60 MPH 96H 16/1800Z 17.3N 112.2W 30 KT 35 MPH...POST-TROPICAL 120H 17/1800Z...DISSIPATED $$ Forecaster Kelly

Issued at 300 PM CST Thu Jun 12 2025 448 WTPZ34 KNHC 122044 TCPEP4 BULLETIN Potential Tropical Cyclone Four-E Advisory Number 1 NWS National Hurricane Center Miami FL EP042025 300 PM CST Thu Jun 12 2025 ...DISTURBANCE HAS THE POTENTIAL TO BRING TROPICAL STORM FORCE WINDS TO COASTAL SOUTHWESTERN MEXICO... ...TROPICAL STORM WATCHES ISSUED FOR MEXICO... SUMMARY OF 300 PM CST...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...11.3N 100.2W ABOUT 450 MI...725 KM SSE OF ZIHUATANEJO MEXICO MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H PRESENT MOVEMENT...WNW OR 295 DEGREES AT 7 MPH...11 KM/H MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Mexico has issued a Tropical Storm Watch for the coast of Mexico from Tecpan De Galeana to Manzanillo. 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. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 300 PM CST (2100 UTC), the disturbance was centered near latitude 11.3 North, longitude 100.2 West. The system is moving toward the west-northwest near 7 mph (11 km/h). A west-northwest to northwestward motion is expected during the next few days. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Strengthening is expected during the next few days, and the system is forecast to become a tropical storm on Friday and continue strengthening 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, Michoacan, 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 by 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 PM CST. Next complete advisory at 900 PM CST. $$ Forecaster Kelly