Hurricane Calvin Forecast Discussion Number 17

2 years ago
Issued at 1100 AM HST Sat Jul 15 2023 000 WTPZ43 KNHC 152033 TCDEP3 Hurricane Calvin Discussion Number 17 NWS National Hurricane Center Miami FL EP032023 1100 AM HST Sat Jul 15 2023 The satellite appearance of Calvin has shown some ill effects today from cooler SSTs and some drier air in its surrounding environment. A 1512 UTC SSMIS 89 GHz passive microwave image of the hurricane showed the eyewall was open to the east, where a dry slot was noted earlier wrapping around that portion of the circulation. Since then, the eye has become a bit warmer and more pronounced in infrared satellite imagery, and some deeper inner-core convection has wrapped around the center. The latest objective and subjective satellite intensity estimates range from 77-90 kt. Based on a blend of these data and recent satellite trends, the initial intensity is held at 85 kt for this advisory. Weakening is expected during the next few days as the cyclone moves into a drier and more stable air mass over sub-26C SSTs. In fact, model-simulated satellite imagery from the GFS and ECMWF suggest Calvin could lose most, or briefly all, of its convection once it enters the central Pacific basin. However, the underlying SSTs become slightly warmer between 48-96 h while the deep-layer shear diagnosed by the global models is low to moderate. Therefore, it seems that Calvin could regenerate new bursts of convection on its approach to Hawaii, which is shown by the global and hurricane models. Therefore, the NHC forecast keeps Calvin a tropical cyclone through 96 h. Regardless of its status, the cyclone appears likely to maintain some tropical-storm-force winds in the northern portion of its circulation as it approaches Hawaii. The global model fields suggest the system will be close to opening into a trough by or shortly after day 5. The long-term motion of Calvin is westward at 280/14 kt. A westward to west-northwestward motion will continue through the forecast period as the cyclone is steered by a mid-level ridge entrenched over the eastern Pacific. Calvin is forecast to cross 140W and enter the central Pacific basin on Monday morning and approach the Hawaiian Islands on Tuesday into early Wednesday. The various track models continue to bring Calvin near or over the Big Island of Hawaii, but exactly where it will track relative to the island is still unclear given the cross-track spread noted at day 3 and beyond. The updated NHC forecast has been adjusted slightly faster than the previous one, but otherwise very little change was made. KEY MESSAGES: 1. Calvin is forecast to move across the central Pacific Ocean and approach the Hawaiian Islands early next week. It is too early to determine the exact location and magnitude of potential impacts given uncertainties in the track, intensity, and structure of Calvin as it approaches the islands. Interests in Hawaii should closely monitor the latest forecast updates. FORECAST POSITIONS AND MAX WINDS INIT 15/2100Z 15.0N 130.4W 85 KT 100 MPH 12H 16/0600Z 15.6N 132.7W 75 KT 85 MPH 24H 16/1800Z 16.3N 135.8W 65 KT 75 MPH 36H 17/0600Z 16.8N 139.0W 55 KT 65 MPH 48H 17/1800Z 17.3N 142.5W 50 KT 60 MPH 60H 18/0600Z 17.7N 146.2W 45 KT 50 MPH 72H 18/1800Z 18.3N 149.9W 40 KT 45 MPH 96H 19/1800Z 19.4N 156.8W 35 KT 40 MPH 120H 20/1800Z 20.5N 164.0W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ Forecaster Reinhart
NHC Webmaster

Hurricane Calvin Wind Speed Probabilities Number 17

2 years ago
Issued at 2100 UTC SAT JUL 15 2023 000 FOPZ13 KNHC 152033 PWSEP3 HURRICANE CALVIN WIND SPEED PROBABILITIES NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032023 2100 UTC SAT JUL 15 2023 AT 2100Z THE CENTER OF HURRICANE CALVIN WAS LOCATED NEAR LATITUDE 15.0 NORTH...LONGITUDE 130.4 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 85 KTS...100 MPH...155 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 SAT 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 SAT 06Z SUN 18Z SUN 06Z MON 18Z MON 18Z TUE 18Z WED PERIODS TO TO TO TO TO TO TO 06Z SUN 18Z SUN 06Z MON 18Z MON 18Z TUE 18Z WED 18Z THU FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT 15N 130W 34 99 X(99) X(99) X(99) X(99) X(99) X(99) 15N 130W 50 99 X(99) X(99) X(99) X(99) X(99) X(99) 15N 130W 64 97 X(97) X(97) X(97) X(97) X(97) X(97) 15N 135W 34 3 55(58) 1(59) X(59) X(59) X(59) X(59) 15N 135W 50 1 6( 7) X( 7) X( 7) X( 7) X( 7) X( 7) 15N 135W 64 X 1( 1) X( 1) X( 1) X( 1) X( 1) X( 1) 20N 135W 34 1 3( 4) 1( 5) X( 5) X( 5) X( 5) X( 5) 15N 140W 34 X 2( 2) 8(10) 6(16) X(16) X(16) X(16) 20N 140W 34 X X( X) 4( 4) 2( 6) 1( 7) X( 7) X( 7) 15N 145W 34 X X( X) X( X) 2( 2) 4( 6) X( 6) X( 6) 20N 145W 34 X X( X) X( X) 2( 2) 7( 9) X( 9) X( 9) 15N 150W 34 X X( X) X( X) X( X) 3( 3) X( 3) X( 3) 20N 150W 34 X X( X) X( X) X( X) 11(11) 2(13) X(13) 20N 151W 34 X X( X) X( X) X( X) 6( 6) 6(12) X(12) BUOY 51004 34 X X( X) X( X) X( X) 3( 3) 8(11) X(11) 20N 154W 34 X X( X) X( X) X( X) 1( 1) 9(10) X(10) HILO 34 X X( X) X( X) X( X) X( X) 9( 9) 1(10) 18N 156W 34 X X( X) X( X) X( X) X( X) 5( 5) 1( 6) SOUTH POINT 34 X X( X) X( X) X( X) X( X) 7( 7) 1( 8) 21N 156W 34 X X( X) X( X) X( X) X( X) 4( 4) 1( 5) KAILUA-KONA 34 X X( X) X( X) X( X) X( X) 6( 6) 1( 7) KAHULUI 34 X X( X) X( X) X( X) X( X) 4( 4) 1( 5) 21N 158W 34 X X( X) X( X) X( X) X( X) 2( 2) 2( 4) HANA 34 X X( X) X( X) X( X) X( X) 5( 5) 1( 6) LANAI CITY 34 X X( X) X( X) X( X) X( X) 4( 4) 1( 5) KAUNAKAKAI 34 X X( X) X( X) X( X) X( X) 3( 3) 1( 4) BUOY 51002 34 X X( X) X( X) X( X) X( X) 2( 2) 1( 3) HONOLULU 34 X X( X) X( X) X( X) X( X) 2( 2) 2( 4) JOINT BASE PHH 34 X X( X) X( X) X( X) X( X) 2( 2) 2( 4) 20N 160W 34 X X( X) X( X) X( X) X( X) 1( 1) 5( 6) NIIHAU 34 X X( X) X( X) X( X) X( X) X( X) 3( 3) 21N 160W 34 X X( X) X( X) X( X) X( X) X( X) 4( 4) BUOY 51003 34 X X( X) X( X) X( X) X( X) X( X) 4( 4) $$ FORECASTER REINHART
NHC Webmaster

Hurricane Calvin Public Advisory Number 17

2 years ago
Issued at 1100 AM HST Sat Jul 15 2023 000 WTPZ33 KNHC 152033 TCPEP3 BULLETIN Hurricane Calvin Advisory Number 17 NWS National Hurricane Center Miami FL EP032023 1100 AM HST Sat Jul 15 2023 ...CALVIN MOVING WESTWARD OVER OPEN WATERS... ...EXPECTED TO MOVE INTO THE CENTRAL PACIFIC BASIN EARLY MONDAY... SUMMARY OF 1100 AM HST...2100 UTC...INFORMATION ----------------------------------------------- LOCATION...15.0N 130.4W ABOUT 1445 MI...2325 KM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA ABOUT 1660 MI...2670 KM E OF HILO HAWAII MAXIMUM SUSTAINED WINDS...100 MPH...155 KM/H PRESENT MOVEMENT...W OR 280 DEGREES AT 16 MPH...26 KM/H MINIMUM CENTRAL PRESSURE...975 MB...28.80 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. Interests in Hawaii should monitor the progress of Calvin. DISCUSSION AND OUTLOOK ---------------------- At 1100 AM HST (2100 UTC), the center of Hurricane Calvin was located near latitude 15.0 North, longitude 130.4 West. Calvin is moving toward the west near 16 mph (26 km/h), and this general motion at a similar or slightly faster forward speed is expected during the next few days. Maximum sustained winds are near 100 mph (155 km/h) with higher gusts. Weakening is forecast through early next week. Hurricane-force winds extend outward up to 25 miles (35 km) from the center and tropical-storm-force winds extend outward up to 105 miles (165 km). The estimated minimum central pressure is 975 mb (28.80 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Calvin can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP3 and WMO header WTPZ43 KNHC and on the web at hurricanes.gov/text/miatcdep3.shtml SURF: Swells generated by Calvin are expected to begin reaching the Hawaiian Islands early next week. 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 500 PM HST. $$ Forecaster Reinhart
NHC Webmaster

Hurricane Calvin Forecast Advisory Number 17

2 years ago
Issued at 2100 UTC SAT JUL 15 2023 665 WTPZ23 KNHC 152032 TCMEP3 HURRICANE CALVIN FORECAST/ADVISORY NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032023 2100 UTC SAT JUL 15 2023 NOTICE... LAND-BASED TROPICAL CYCLONE WATCHES AND WARNINGS ARE NO LONGER INCLUDED IN THE TROPICAL CYCLONE FORECAST/ADVISORY...(TCM). CURRENT LAND-BASED COASTAL WATCHES AND WARNINGS CAN BE FOUND IN THE MOST RECENTLY ISSUED TROPICAL CYCLONE PUBLIC ADVISORY...(TCP). HURRICANE CENTER LOCATED NEAR 15.0N 130.4W AT 15/2100Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE WEST OR 280 DEGREES AT 14 KT ESTIMATED MINIMUM CENTRAL PRESSURE 975 MB MAX SUSTAINED WINDS 85 KT WITH GUSTS TO 105 KT. 64 KT....... 20NE 15SE 15SW 20NW. 50 KT....... 50NE 30SE 30SW 40NW. 34 KT....... 90NE 80SE 70SW 90NW. 12 FT SEAS..180NE 120SE 120SW 180NW. 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 15.0N 130.4W AT 15/2100Z AT 15/1800Z CENTER WAS LOCATED NEAR 14.8N 129.7W FORECAST VALID 16/0600Z 15.6N 132.7W MAX WIND 75 KT...GUSTS 90 KT. 64 KT... 15NE 10SE 10SW 15NW. 50 KT... 40NE 30SE 30SW 40NW. 34 KT... 90NE 70SE 60SW 90NW. FORECAST VALID 16/1800Z 16.3N 135.8W MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 10NE 0SE 0SW 10NW. 50 KT... 30NE 20SE 20SW 30NW. 34 KT... 80NE 60SE 50SW 80NW. FORECAST VALID 17/0600Z 16.8N 139.0W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 30NE 0SE 0SW 20NW. 34 KT... 80NE 50SE 40SW 70NW. FORECAST VALID 17/1800Z 17.3N 142.5W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 20NE 0SE 0SW 20NW. 34 KT... 70NE 40SE 30SW 60NW. FORECAST VALID 18/0600Z 17.7N 146.2W MAX WIND 45 KT...GUSTS 55 KT. 34 KT... 60NE 30SE 20SW 50NW. FORECAST VALID 18/1800Z 18.3N 149.9W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 60NE 20SE 20SW 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 19/1800Z 19.4N 156.8W MAX WIND 35 KT...GUSTS 45 KT. OUTLOOK VALID 20/1800Z 20.5N 164.0W...POST-TROP/REMNT LOW MAX WIND 30 KT...GUSTS 40 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 15.0N 130.4W NEXT ADVISORY AT 16/0300Z $$ FORECASTER REINHART
NHC Webmaster

SPC Jul 15, 2023 2000 UTC Day 1 Convective Outlook

2 years ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sat Jul 15 2023 Valid 152000Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHERN HIGH PLAINS... ...SUMMARY... Severe thunderstorms are expected across the High Plains of eastern New Mexico into the Texas South Plains today, where isolated very large hail and significant damaging wind gusts will be possible. Isolated strong to severe storms may also be noted from the Tennessee and Ohio Valley region to the mid-Atlantic and northeast states. ...ArklaTex into northern TX... A plume of deep moisture with PWAT over 2.00" remains across the area, and visible imagery shows signs of convection developing from southeast OK into southwest AR. Given strong instability, locally strong downbursts or marginal hail will be possible, and the Marginal Risk has been expanded into southwest AR. Farther west into northern TX, strong heating south of the area of cloudiness is leading to increasing CU fields, and isolated downbursts will be possible with any storms that form in this area as well. For more information see forthcoming mesoscale discussion 1566. ..Jewell.. 07/15/2023 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jul 15 2023/ ...Eastern NM/West TX... An outflow boundary resulting from overnight storms extended from northeast NM into the southern TX Panhandle this morning, and was continuing to move west towards the higher terrain of northeast NM. Clearing/heating of a moist air mass to the north of this boundary, in combination with mid-level lapse rates of around 8 deg C/km, will result in MLCAPE of 1500 to 2000 J/kg by afternoon. Large scale forcing is subtle, but thunderstorm development is expected over the mountains of northeast NM, with storms spreading southeastward toward the TX Panhandle this evening. Northwesterly mid-level flow will result in ample shear for supercells capable of large to very large hail initially, with damaging winds becoming increasingly likely as storms congeal into a southeast-moving MCS with time. A small significant hail area has been introduced where initial supercell development is most probable, and a significant wind area has been introduced based on the 12z HREF CAM guidance and where higher confidence exists in 65 kt/75 mph gusts occurring. ...Ohio Valley/Appalachians to Northeast... Broadly cyclonic upper-level flow will persist over much of the eastern U.S. today. Thunderstorms are expected to develop, or diurnally intensify, along and ahead of a cold front as it moves steadily east this afternoon. In addition, somewhat greater coverage is expected in association with a mid-level impulse moving east through KY/TN. A rather broad area will exist of at least moderate MLCAPE and sufficient mid-level flow for some degree of storm organization, and the Marginal Risk has been expanded east across portions the mid-Atlantic and northeast states. Where pockets of greater heating can occur, locally higher MLCAPE and steep low-level lapse rates will support a risk for damaging wind gusts. ...Central Nebraska... Thunderstorms may develop in the 10z-12z time frame Sunday morning within a low-level warm/moist advection regime over central NE. Although some potential for strong storms will exist, have opted not to introduce a Marginal Risk area with this outlook due to concerns regarding the degree of elevated instability. Read more

SPC Jul 15, 2023 2000 UTC Day 1 Convective Outlook

2 years ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sat Jul 15 2023 Valid 152000Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHERN HIGH PLAINS... ...SUMMARY... Severe thunderstorms are expected across the High Plains of eastern New Mexico into the Texas South Plains today, where isolated very large hail and significant damaging wind gusts will be possible. Isolated strong to severe storms may also be noted from the Tennessee and Ohio Valley region to the mid-Atlantic and northeast states. ...ArklaTex into northern TX... A plume of deep moisture with PWAT over 2.00" remains across the area, and visible imagery shows signs of convection developing from southeast OK into southwest AR. Given strong instability, locally strong downbursts or marginal hail will be possible, and the Marginal Risk has been expanded into southwest AR. Farther west into northern TX, strong heating south of the area of cloudiness is leading to increasing CU fields, and isolated downbursts will be possible with any storms that form in this area as well. For more information see forthcoming mesoscale discussion 1566. ..Jewell.. 07/15/2023 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jul 15 2023/ ...Eastern NM/West TX... An outflow boundary resulting from overnight storms extended from northeast NM into the southern TX Panhandle this morning, and was continuing to move west towards the higher terrain of northeast NM. Clearing/heating of a moist air mass to the north of this boundary, in combination with mid-level lapse rates of around 8 deg C/km, will result in MLCAPE of 1500 to 2000 J/kg by afternoon. Large scale forcing is subtle, but thunderstorm development is expected over the mountains of northeast NM, with storms spreading southeastward toward the TX Panhandle this evening. Northwesterly mid-level flow will result in ample shear for supercells capable of large to very large hail initially, with damaging winds becoming increasingly likely as storms congeal into a southeast-moving MCS with time. A small significant hail area has been introduced where initial supercell development is most probable, and a significant wind area has been introduced based on the 12z HREF CAM guidance and where higher confidence exists in 65 kt/75 mph gusts occurring. ...Ohio Valley/Appalachians to Northeast... Broadly cyclonic upper-level flow will persist over much of the eastern U.S. today. Thunderstorms are expected to develop, or diurnally intensify, along and ahead of a cold front as it moves steadily east this afternoon. In addition, somewhat greater coverage is expected in association with a mid-level impulse moving east through KY/TN. A rather broad area will exist of at least moderate MLCAPE and sufficient mid-level flow for some degree of storm organization, and the Marginal Risk has been expanded east across portions the mid-Atlantic and northeast states. Where pockets of greater heating can occur, locally higher MLCAPE and steep low-level lapse rates will support a risk for damaging wind gusts. ...Central Nebraska... Thunderstorms may develop in the 10z-12z time frame Sunday morning within a low-level warm/moist advection regime over central NE. Although some potential for strong storms will exist, have opted not to introduce a Marginal Risk area with this outlook due to concerns regarding the degree of elevated instability. Read more

SPC Day 2 Fire Weather Outlook

2 years ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0233 PM CDT Sat Jul 15 2023 Valid 161200Z - 171200Z The previous forecast remains on track. No changes were made. ..Marsh.. 07/15/2023 .PREV DISCUSSION... /ISSUED 0126 AM CDT Sat Jul 15 2023/ ...Synopsis... An upper-level trough will move into the Northwest on Sunday. At the surface a lee trough will develop to the east of the Cascades. ...Columbia Basin Vicinity... Mid-level winds will increase through the day across Oregon/Washington. The mid-level jet, however, will not overspread the region until late Sunday into Monday morning. During the afternoon, surface winds will increase in the lee of the Cascades as the surface trough deepens. Winds will be the strongest within the Cascade gaps and Columbia Gorge. Winds in these locations could reach 15-20 mph (locally higher) with winds becoming lighter into the Columbia Basin itself. RH will fall to 15-20%. A few hours of elevated fire weather are expected within the terrain features with locally elevated conditions possible within the Basin. ...Northern Nevada... With mid-level flow increasing from the south/southwest, a period of marginally elevated meteorological conditions will be possible within northern Nevada. Fuels are not critically dry at present and, given the relatively weak winds, only locally elevated conditions are expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

2 years ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0233 PM CDT Sat Jul 15 2023 Valid 161200Z - 171200Z The previous forecast remains on track. No changes were made. ..Marsh.. 07/15/2023 .PREV DISCUSSION... /ISSUED 0126 AM CDT Sat Jul 15 2023/ ...Synopsis... An upper-level trough will move into the Northwest on Sunday. At the surface a lee trough will develop to the east of the Cascades. ...Columbia Basin Vicinity... Mid-level winds will increase through the day across Oregon/Washington. The mid-level jet, however, will not overspread the region until late Sunday into Monday morning. During the afternoon, surface winds will increase in the lee of the Cascades as the surface trough deepens. Winds will be the strongest within the Cascade gaps and Columbia Gorge. Winds in these locations could reach 15-20 mph (locally higher) with winds becoming lighter into the Columbia Basin itself. RH will fall to 15-20%. A few hours of elevated fire weather are expected within the terrain features with locally elevated conditions possible within the Basin. ...Northern Nevada... With mid-level flow increasing from the south/southwest, a period of marginally elevated meteorological conditions will be possible within northern Nevada. Fuels are not critically dry at present and, given the relatively weak winds, only locally elevated conditions are expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Jul 15, 2023 1730 UTC Day 2 Convective Outlook

2 years ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234 PM CDT Sat Jul 15 2023 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM KANSAS INTO NORTHWEST MISSOURI... ...SUMMARY... Scattered severe hail and wind is possible from the central Plains eastward into Illinois. Isolated strong storms will be possible over the Northeast. ...Synopsis... An unseasonably strong upper cyclone will remain over much of Ontario and into the Great Lakes, with strong northwest flow over much of the area extending southwestward into the central Plains. Cool temperatures aloft will also accompany this regime, with 500 mb temperatures to -10 C as far south as I-70. A leading meridional upper wave will eject northeastward across New England during the day, enhancing shear over New England. However, temperatures aloft will be relatively warm. Counteracting this warmth aloft will be robust low-level moisture with dewpoints firmly in the 70s F. Deep-layer southerly winds will maintain lift through warm advection processes, while enhancing low-level shear ahead of an elongated surface trough extending southward into VA/NC. To the west, a more prominent wave will rotate southeastward across the upper MS valley and into parts of IL, IN and Lower MI, with a notable increase in lift/differential divergence. Moisture ahead of the wind shift from KS into IA will not be as robust as previous days, but steep lapse rates will counteract this negative factor and likely result in scattered severe hail or wind. ...Central Plains eastward into IL... Early day storms are forecast over parts of southeast NE, and outflows will likely accompany this activity. Strong heating will combine with the cool air aloft ahead of this activity to either reinvigorate these storms or more likely produce new storms, especially extending southwestward into KS along I-70. Here, moderate instability as well as lengthy, straight hodographs will favor cells capable of hail initially, with merging outflow producing damaging gusts. As such, the area has been upgraded to a Slight Risk. Other sporadic hail cores are possible farther east into IA/MO/IL, where shear will favor cellular mode with 40 kt deep-layer shear. ...Much of the Northeast... Areas of rain and storms are likely to be ongoing from VA northward into NY and southern New England with bands of convection possible oriented SSW to NNE. Given the long duration of storms throughout the period, chances for locally strong gusts or even a brief/weak tornado have been extended eastward into southern New England where high dewpoints along with marginal 0-1 SRH up to 100 m2/s2 may support transient areas of rotation within the more prolonged bands/zones of convection. ..Jewell.. 07/15/2023 Read more

SPC Jul 15, 2023 1730 UTC Day 2 Convective Outlook

2 years ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234 PM CDT Sat Jul 15 2023 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM KANSAS INTO NORTHWEST MISSOURI... ...SUMMARY... Scattered severe hail and wind is possible from the central Plains eastward into Illinois. Isolated strong storms will be possible over the Northeast. ...Synopsis... An unseasonably strong upper cyclone will remain over much of Ontario and into the Great Lakes, with strong northwest flow over much of the area extending southwestward into the central Plains. Cool temperatures aloft will also accompany this regime, with 500 mb temperatures to -10 C as far south as I-70. A leading meridional upper wave will eject northeastward across New England during the day, enhancing shear over New England. However, temperatures aloft will be relatively warm. Counteracting this warmth aloft will be robust low-level moisture with dewpoints firmly in the 70s F. Deep-layer southerly winds will maintain lift through warm advection processes, while enhancing low-level shear ahead of an elongated surface trough extending southward into VA/NC. To the west, a more prominent wave will rotate southeastward across the upper MS valley and into parts of IL, IN and Lower MI, with a notable increase in lift/differential divergence. Moisture ahead of the wind shift from KS into IA will not be as robust as previous days, but steep lapse rates will counteract this negative factor and likely result in scattered severe hail or wind. ...Central Plains eastward into IL... Early day storms are forecast over parts of southeast NE, and outflows will likely accompany this activity. Strong heating will combine with the cool air aloft ahead of this activity to either reinvigorate these storms or more likely produce new storms, especially extending southwestward into KS along I-70. Here, moderate instability as well as lengthy, straight hodographs will favor cells capable of hail initially, with merging outflow producing damaging gusts. As such, the area has been upgraded to a Slight Risk. Other sporadic hail cores are possible farther east into IA/MO/IL, where shear will favor cellular mode with 40 kt deep-layer shear. ...Much of the Northeast... Areas of rain and storms are likely to be ongoing from VA northward into NY and southern New England with bands of convection possible oriented SSW to NNE. Given the long duration of storms throughout the period, chances for locally strong gusts or even a brief/weak tornado have been extended eastward into southern New England where high dewpoints along with marginal 0-1 SRH up to 100 m2/s2 may support transient areas of rotation within the more prolonged bands/zones of convection. ..Jewell.. 07/15/2023 Read more

Eastern North Pacific Tropical Weather Outlook

2 years ago

611
ABPZ20 KNHC 151722
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Sat Jul 15 2023

For the eastern North Pacific...east of 140 degrees west longitude:

Active Systems:
The National Hurricane Center is issuing advisories on Hurricane
Calvin, located more than 1300 miles west-southwest of the southern
tip of the Baja California peninsula.

South of Southwestern Mexico:
An area of low pressure could form well south of the coast of
southwestern Mexico during the next several days. Some gradual
development of this system is possible thereafter as it moves
generally west-northwestward over the central portion of the eastern
Pacific basin.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.

$$
Forecaster Reinhart

NHC Webmaster

SPC MD 1553

2 years ago
MD 1553 CONCERNING SEVERE THUNDERSTORM WATCH 491...493... FOR PORTIONS OF CENTRAL MISSOURI
Mesoscale Discussion 1553 NWS Storm Prediction Center Norman OK 0500 PM CDT Fri Jul 14 2023 Areas affected...Portions of central Missouri Concerning...Severe Thunderstorm Watch 491...493... Valid 142200Z - 142330Z The severe weather threat for Severe Thunderstorm Watch 491, 493 continues. SUMMARY...A threat for severe wind gusts will likely extend into central/east-central Missouri. There is some uncertainty how far east the organized bowing segment will progress. DISCUSSION...Long radar/satellite loops indicate outflow from prior convection has reached near the I-70 corridor in Missouri. A cluster of convection has developed north-northwest of St. Louis in a weakly sheared environment. Outflow has quickly spread away from this cluster. The well-organized bowing structure (with a history of measured severe gusts and wind damage) now in the eastern Kansas City suburbs should continue to the east likely just south of the primary outflow boundary where the airmass has at least slowly tried to recover this afternoon. The overall eastern extent of the severe threat with the bowing segment is somewhat in doubt given the outflow from the weak convection that may spread southward ahead of it. Shear should at least modestly increase with time given the approach of an upstream shortwave trough. The thermodynamic environment and storm-scale organization trends will likely be the modulators of the severe threat duration. ..Wendt.. 07/14/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LSX...SGF...EAX... LAT...LON 38409427 38549452 38749447 39069428 39269406 39219372 39189320 39059239 38889137 38529092 38279104 38159163 38179290 38259388 38409427 Read more

SPC Severe Thunderstorm Watch 493

2 years ago
WW 493 SEVERE TSTM AR MO OK 142155Z - 150500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 493 NWS Storm Prediction Center Norman OK 455 PM CDT Fri Jul 14 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northwest Arkansas Central and Southern Missouri Northern and Central Oklahoma * Effective this Friday afternoon from 455 PM until Midnight CDT. * Primary threats include... Widespread damaging winds likely with isolated significant gusts to 85 mph possible Scattered large hail and isolated very large hail events to 2 inches in diameter possible A tornado or two possible SUMMARY...Multiple intense clusters of storms will continue to move southeastward into and across northern Oklahoma and central/southern Missouri, and eventually northwest Arkansas this evening. Corridors of wind damage and potentially significant-strength wind gusts can be expected, especially across northern Oklahoma and perhaps southwest Missouri. The severe thunderstorm watch area is approximately along and 65 statute miles north and south of a line from 80 miles west southwest of Alva OK to 50 miles east southeast of Springfield MO. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU3). 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. && OTHER WATCH INFORMATION...CONTINUE...WW 490...WW 491...WW 492... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 75 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 30030. ...Guyer Read more

SPC Severe Thunderstorm Watch 492 Status Reports

2 years ago
WW 0492 Status Updates
STATUS REPORT ON WW 492 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..DEAN..07/14/23 ATTN...WFO...DVN...LOT...ILX...MKX...ARX... STATUS REPORT FOR WS 492 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC007-011-015-017-037-057-067-071-073-085-095-099-103-107-109- 111-123-125-129-131-137-141-143-155-161-167-169-171-175-177-179- 187-195-201-203-142240- IL . ILLINOIS COUNTIES INCLUDED ARE BOONE BUREAU CARROLL CASS DE KALB FULTON HANCOCK HENDERSON HENRY JO DAVIESS KNOX LA SALLE LEE LOGAN MCDONOUGH MCHENRY MARSHALL MASON MENARD MERCER MORGAN OGLE PEORIA PUTNAM ROCK ISLAND SANGAMON SCHUYLER SCOTT STARK STEPHENSON TAZEWELL WARREN WHITESIDE WINNEBAGO WOODFORD IAC031-045-057-061-087-097-103-105-111-113-115-139-163-183- 142240- IA . IOWA COUNTIES INCLUDED ARE Read more

SPC Severe Thunderstorm Watch 492

2 years ago
WW 492 SEVERE TSTM IA IL MO WI 142050Z - 150300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 492 NWS Storm Prediction Center Norman OK 350 PM CDT Fri Jul 14 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Iowa Western and northern Illinois Extreme northeast Missouri Southern Wisconsin * Effective this Friday afternoon and evening from 350 PM until 1000 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Scattered large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...Widely scattered severe thunderstorms will continue to develop and move east across the watch area through early this evening. Damaging wind gusts and hail will be the primary severe weather risks. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 45 miles east of Quincy IL to 40 miles northwest of Janesville WI. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). 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. && OTHER WATCH INFORMATION...CONTINUE...WW 490...WW 491... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 27020. ...Bunting Read more

SPC MD 1552

2 years ago
MD 1552 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PARTS OF THE CENTRAL/SOUTHERN HIGH PLAINS
Mesoscale Discussion 1552 NWS Storm Prediction Center Norman OK 0400 PM CDT Fri Jul 14 2023 Areas affected...Parts of the central/southern High Plains Concerning...Severe potential...Watch possible Valid 142100Z - 142300Z Probability of Watch Issuance...60 percent SUMMARY...The severe-storm risk will increase across the central and southern High Plains during the next few hours. A watch may eventually be needed for parts of the area. DISCUSSION...Latest visible satellite imagery and surface observations indicate a surface boundary/wind shift extending east-northeastward from northeastern NM into southwestern KS, where it intersects a southward-moving outflow boundary associated with an MCS farther east. In the near-term, an isolated thunderstorm is attempting to deepen along the wind shift in northeastern NM, where a long/straight hodograph and steep deep-layer lapse rates will support supercells capable of large hail and severe gusts. Farther east, boundary-layer cumulus is deepening across parts of southwestern KS into the OK Panhandle ahead of the southward-advancing outflow, and additional thunderstorm development is possible here during the next few hours. Similar to northeastern NM, a moderately unstable air mass and around 40-50 kt of effective shear will support organized storms including supercells capable of large hail and damaging winds. Convective evolution is somewhat unclear across this area, though current thinking is that a watch may eventually be needed for parts of the area. ..Weinman/Bunting.. 07/14/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN...DDC...AMA...PUB...ABQ... LAT...LON 35770211 35940291 36220366 36570386 36980378 37260337 37760251 38070170 38070127 37950084 36959963 36639939 36159939 35819970 35710044 35770211 Read more

SPC Severe Thunderstorm Watch 491 Status Reports

2 years ago
WW 0491 Status Updates
STATUS REPORT ON WW 491 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 WSW FLV TO 15 E STJ TO 20 ENE CDJ. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1551 ..GLEASON..07/14/23 ATTN...WFO...EAX...SGF... STATUS REPORT FOR WS 491 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC011-021-037-091-103-107-121-209-142140- KS . KANSAS COUNTIES INCLUDED ARE BOURBON CHEROKEE CRAWFORD JOHNSON LEAVENWORTH LINN MIAMI WYANDOTTE MOC011-013-015-021-025-033-037-039-047-049-057-077-083-085-095- 097-101-107-109-117-159-165-167-177-185-195-217-142140- MO . MISSOURI COUNTIES INCLUDED ARE BARTON BATES BENTON BUCHANAN CALDWELL CARROLL CASS CEDAR CLAY CLINTON DADE GREENE HENRY HICKORY JACKSON JASPER JOHNSON LAFAYETTE LAWRENCE LIVINGSTON PETTIS Read more