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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0215 PM CDT Thu Jul 13 2023 Valid 141200Z - 151200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 07/13/2023 .PREV DISCUSSION... /ISSUED 1216 AM CDT Thu Jul 13 2023/ ...Synopsis... The Southwest mid-level high will shift westward on Friday with very warm temperatures expected across much of the region and generally light winds. This will keep fire weather concerns low, though a few locally enhanced breezes may bring briefly Elevated concerns. Given the localized nature of this threat, no areas were included. The extremely warm temperatures and mostly sunny skies will work to further dry already critically dry fuels across much of the Southwest. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

The Scottsdale City Council unanimously agreed to ban natural grass in front of future single-family homes as the water shortage in the region made it essential to conserve water. The new ordinance takes effect for new houses constructed or permitted after August 15. In June, limits were placed on construction in the Phoenix area, due to groundwater depletion. CNN (Atlanta, Ga.), July 13, 2023

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Jul 13 2023 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF KANSAS...OKLAHOMA...AND SOUTHWEST MISSOURI... ...SUMMARY... Thunderstorms producing damaging wind and sporadic hail are forecast over much of the central Plains on Friday. Isolated damaging gusts or marginal hail will also be possible over parts of the Mid Atlantic and southern New England, and into parts of the southern High Plains. ...Synopsis... A large upper low will remain over Canada, with an upper ridge over the Southwest. In between, moderate northwest flow aloft will persist over the Plains. To the east, various weaker embedded waves will affect parts of the OH Valley, Mid Atlantic, and Great Lakes. Moisture will remain plentiful east of the Rockies, with the only exception the northern Plains and upper MS Valley where drier air will spread in from the northwest. ...Much of the central Plains... Storms are forecast to be ongoing over NE Friday morning near a stationary front and where low-level theta-e will be substantial. Some of these storms could have hail relatively early in the day, with an increasing threat throughout the day as the storms and the boundary push south into KS where heating will occur. Large hail is most likely with the initial activity, with a strong model signal of an MCS eventually pushing south/southeast into OK and southwest MO late. Damaging winds, as well as heavy rain, will become the primary concern. ..NC into southern New England... A deep-layer moist plume will remain in place with 850 mb winds out of the south/southwest, and a weak surface trough from the Carolinas into southern New England. Little heating will be needed to uncap the air mass, with storms focused over NC and VA during the day where lapse rates will be steepest. Another area of focus will be over southern New England where southerly winds will bring 70s F dewpoints northward across MA. Shear will not be very strong but veering winds with height may favor a few cells producing marginal hail. ...Upper Great Lakes/MI area... Moistening will occur over Lower MI during the day as with a west/southwest low-level wind regime, beneath cool midlevel temperatures and 500 mb winds over 40 kt. Strong heating will occur, which when combined with the rising dewpoints out of the southwest will yield plentiful instability. Scattered storms are expected to form over interior Lower MI during the late afternoon by virtue of weak convergence and an uncapped air mass, and lengthy straight hodographs will favor cellular storm mode with hail possible. ..Jewell.. 07/13/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Jul 13 2023 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF KANSAS...OKLAHOMA...AND SOUTHWEST MISSOURI... ...SUMMARY... Thunderstorms producing damaging wind and sporadic hail are forecast over much of the central Plains on Friday. Isolated damaging gusts or marginal hail will also be possible over parts of the Mid Atlantic and southern New England, and into parts of the southern High Plains. ...Synopsis... A large upper low will remain over Canada, with an upper ridge over the Southwest. In between, moderate northwest flow aloft will persist over the Plains. To the east, various weaker embedded waves will affect parts of the OH Valley, Mid Atlantic, and Great Lakes. Moisture will remain plentiful east of the Rockies, with the only exception the northern Plains and upper MS Valley where drier air will spread in from the northwest. ...Much of the central Plains... Storms are forecast to be ongoing over NE Friday morning near a stationary front and where low-level theta-e will be substantial. Some of these storms could have hail relatively early in the day, with an increasing threat throughout the day as the storms and the boundary push south into KS where heating will occur. Large hail is most likely with the initial activity, with a strong model signal of an MCS eventually pushing south/southeast into OK and southwest MO late. Damaging winds, as well as heavy rain, will become the primary concern. ..NC into southern New England... A deep-layer moist plume will remain in place with 850 mb winds out of the south/southwest, and a weak surface trough from the Carolinas into southern New England. Little heating will be needed to uncap the air mass, with storms focused over NC and VA during the day where lapse rates will be steepest. Another area of focus will be over southern New England where southerly winds will bring 70s F dewpoints northward across MA. Shear will not be very strong but veering winds with height may favor a few cells producing marginal hail. ...Upper Great Lakes/MI area... Moistening will occur over Lower MI during the day as with a west/southwest low-level wind regime, beneath cool midlevel temperatures and 500 mb winds over 40 kt. Strong heating will occur, which when combined with the rising dewpoints out of the southwest will yield plentiful instability. Scattered storms are expected to form over interior Lower MI during the late afternoon by virtue of weak convergence and an uncapped air mass, and lengthy straight hodographs will favor cellular storm mode with hail possible. ..Jewell.. 07/13/2023 Read more

000
ABPZ20 KNHC 131733
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Thu Jul 13 2023

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

Active Systems:
The National Hurricane Center is issuing advisories on recently
upgraded Hurricane Calvin, located about 850 miles 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 early to middle part of next week.
Some gradual development of this system is possible thereafter as it
moves westward to west-northwestward over the central potion of the
eastern Pacific basin.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.

$$
Forecaster Berg

Campfires were not permitted in the Mt. Hood National Forest and Columbia River Gorge National Scenic Area, starting Monday, July 10, due to dry and hot conditions. Gorge News Center (Chenoweth, Ore.), July 6, 2023

MD 1507 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF NORTHERN/EASTERN MO INTO A SMALL PART OF WESTERN IL
Mesoscale Discussion 1507 NWS Storm Prediction Center Norman OK 0459 PM CDT Wed Jul 12 2023 Areas affected...Parts of northern/eastern MO into a small part of western IL Concerning...Severe potential...Watch unlikely Valid 122159Z - 122330Z Probability of Watch Issuance...20 percent SUMMARY...Storms may intensify into early evening as they move southeastward, with a threat of isolated hail and damaging gusts. DISCUSSION...Thunderstorms have recently developed in northern MO. Based on satellite and mesoanalysis data, this activity is clearly elevated, and likely will remain so in the short term, given substantial MLCINH across the region. However, even for elevated convection that is likely based around 800 mb, MUCAPE in excess of 1500 J/kg and sufficient deep-layer shear (supported by rather strong midlevel west-northwesterlies) conditionally favor the potential for a few organized storms. If any stronger cells/clusters can mature and be sustained into the early evening, some severe threat may evolve with this activity. Steep midlevel lapse rates will favor some hail potential, while a relatively warm and well-mixed boundary layer could support isolated damaging gusts, despite the relatively strong MLCINH. Uncertainty remains rather high regarding the evolution of this convection into the early evening, given its elevated nature and relative lack of stronger large-scale ascent across the area. Watch issuance is currently considered unlikely, but will become possible if organized storms develop or appear imminent. ..Dean/Guyer.. 07/12/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LSX...EAX... LAT...LON 38009052 39109345 39569350 39899337 39789219 39569145 39249070 39049034 38648961 38388969 38109003 38009052 Read more

WW 0477 Status Updates
STATUS FOR WATCH 0477 HAS NOT BEEN ISSUED YET Read more

WW 477 TORNADO IL IN LM 122050Z - 130300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 477 NWS Storm Prediction Center Norman OK 350 PM CDT Wed Jul 12 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Northern Illinois Extreme northwest Indiana Lake Michigan * Effective this Wednesday afternoon and evening from 350 PM until 1000 PM CDT. * Primary threats include... A few tornadoes and a couple intense tornadoes possible Scattered damaging wind gusts to 70 mph possible Isolated very large hail events to 2 inches in diameter possible SUMMARY...Isolated supercell severe thunderstorms are expected to develop and move east-southeast with a risk for a few tornadoes, large hail and damaging thunderstorm wind gusts. The potential also exists for a strong tornado or two to occur. The tornado watch area is approximately along and 45 statute miles north and south of a line from 35 miles southwest of Rockford IL to 10 miles north northeast of Valparaiso IN. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and 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. && AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 28030. ...Bunting Read more

5-Day Uncertainty Track last updated Wed, 12 Jul 2023 20:37:44 GMT


Wind Speed Probabilities last updated Wed, 12 Jul 2023 21:23:00 GMT

Issued at 1100 AM HST Wed Jul 12 2023 000 WTPZ43 KNHC 122035 TCDEP3 Tropical Storm Calvin Discussion Number 5 NWS National Hurricane Center Miami FL EP032023 1100 AM HST Wed Jul 12 2023 Tropical Storm Calvin continues to strengthen this morning, with an improved structure on hi-res GOES visible satellite imagery. A curved band is beginning to wrap around the center, however, the band has not yet completely filled in around the northern side. Subjective satellite Dvorak estimates from TAFB and SAB were T3.5/55 kt and T3.0/45 kt, respectively, while the latest objective estimates from SATCON and ADT are higher than 55 kt. Given the improved structure on satellite, the initial intensity is raised to 55 kt for this advisory based on a blend of the various intensity estimates. Calvin is in a conducive environment for strengthening, with light-to-moderate vertical wind shear, and warm sea surface temperatures. Steady strengthening is forecast the next several days, with Calvin potentially becoming a hurricane later tonight. Rapid intensification (RI) guidance has increased on this cycle and now shows a roughly 3-in-10 chance for RI to occur during the next 24 hours. Therefore, the NHC intensity forecast is near the upper end of the guidance, and the peak intensity has been slightly raised from the previous forecast. By the weekend, Calvin is expected to cross over cooler SSTs which will likely cause gradual weakening through the remainder of the forecast period. Calvin is moving westward or 275/15 kt. A strong ridge located to the north of Calvin will continue to steer the cyclone westward to west-northwestward throughout the forecast period. Model guidance is in fairly good agreement with the track--the main difference is the forward speed of Calvin with some models moving the storm a little faster (particularly HCCA). The updated NHC track forecast lies near the center of the guidance envelope, but is a little on the faster side of forecast ensembles. FORECAST POSITIONS AND MAX WINDS INIT 12/2100Z 12.8N 113.8W 55 KT 65 MPH 12H 13/0600Z 12.9N 115.9W 65 KT 75 MPH 24H 13/1800Z 13.1N 118.6W 75 KT 85 MPH 36H 14/0600Z 13.6N 121.3W 85 KT 100 MPH 48H 14/1800Z 14.3N 124.3W 85 KT 100 MPH 60H 15/0600Z 14.9N 127.3W 80 KT 90 MPH 72H 15/1800Z 15.6N 130.4W 75 KT 85 MPH 96H 16/1800Z 16.8N 136.7W 60 KT 70 MPH 120H 17/1800Z 17.8N 143.7W 50 KT 60 MPH $$ Forecaster Kelly/Berg

Issued at 2100 UTC WED JUL 12 2023 000 FOPZ13 KNHC 122035 PWSEP3 TROPICAL STORM CALVIN WIND SPEED PROBABILITIES NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032023 2100 UTC WED JUL 12 2023 AT 2100Z THE CENTER OF TROPICAL STORM CALVIN WAS LOCATED NEAR LATITUDE 12.8 NORTH...LONGITUDE 113.8 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 55 KTS...65 MPH...100 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 WED 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 WED 06Z THU 18Z THU 06Z FRI 18Z FRI 18Z SAT 18Z SUN PERIODS TO TO TO TO TO TO TO 06Z THU 18Z THU 06Z FRI 18Z FRI 18Z SAT 18Z SUN 18Z MON FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT 10N 120W 34 X 2( 2) 2( 4) X( 4) X( 4) X( 4) X( 4) 15N 120W 34 X 4( 4) 37(41) 1(42) X(42) X(42) X(42) 15N 120W 50 X 1( 1) 7( 8) X( 8) X( 8) X( 8) X( 8) 15N 120W 64 X X( X) 2( 2) X( 2) X( 2) X( 2) X( 2) 10N 125W 34 X X( X) 1( 1) 2( 3) 1( 4) X( 4) X( 4) 15N 125W 34 X X( X) 3( 3) 63(66) 22(88) X(88) X(88) 15N 125W 50 X X( X) X( X) 30(30) 27(57) X(57) X(57) 15N 125W 64 X X( X) X( X) 12(12) 21(33) X(33) X(33) 20N 125W 34 X X( X) X( X) 1( 1) 1( 2) 1( 3) X( 3) 15N 130W 34 X X( X) X( X) 1( 1) 69(70) 4(74) X(74) 15N 130W 50 X X( X) X( X) X( X) 35(35) 3(38) X(38) 15N 130W 64 X X( X) X( X) X( X) 16(16) 2(18) X(18) 20N 130W 34 X X( X) X( X) X( X) 4( 4) 3( 7) X( 7) 15N 135W 34 X X( X) X( X) X( X) 2( 2) 30(32) 1(33) 15N 135W 50 X X( X) X( X) X( X) X( X) 11(11) X(11) 15N 135W 64 X X( X) X( X) X( X) X( X) 4( 4) X( 4) 20N 135W 34 X X( X) X( X) X( X) X( X) 10(10) 1(11) 15N 140W 34 X X( X) X( X) X( X) X( X) 4( 4) 11(15) 15N 140W 50 X X( X) X( X) X( X) X( X) X( X) 3( 3) 20N 140W 34 X X( X) X( X) X( X) X( X) 3( 3) 13(16) 20N 140W 50 X X( X) X( X) X( X) X( X) X( X) 4( 4) 15N 145W 34 X X( X) X( X) X( X) X( X) X( X) 6( 6) 20N 145W 34 X X( X) X( X) X( X) X( X) X( X) 9( 9) $$ FORECASTER KELLY/BERG

Issued at 1100 AM HST Wed Jul 12 2023 595 WTPZ33 KNHC 122034 TCPEP3 BULLETIN Tropical Storm Calvin Advisory Number 5 NWS National Hurricane Center Miami FL EP032023 1100 AM HST Wed Jul 12 2023 ...CALVIN STRENGTHENING... ...FORECAST TO BECOME A HURRICANE TONIGHT... SUMMARY OF 1100 AM HST...2100 UTC...INFORMATION ----------------------------------------------- LOCATION...12.8N 113.8W ABOUT 745 MI...1195 KM SSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H PRESENT MOVEMENT...W OR 275 DEGREES AT 17 MPH...28 KM/H MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 1100 AM HST (2100 UTC), the center of Tropical Storm Calvin was located near latitude 12.8 North, longitude 113.8 West. Calvin is moving toward the west near 17 mph (28 km/h), and this motion is expected to continue the next several days. Maximum sustained winds have increased to near 65 mph (100 km/h) with higher gusts. Additional strengthening is forecast during the next couple of days, and Calvin is forecast to become a hurricane tonight. Tropical-storm-force winds extend outward up to 60 miles (95 km) from the center. The estimated minimum central pressure is 1000 mb (29.53 inches). HAZARDS AFFECTING LAND ---------------------- None NEXT ADVISORY ------------- Next complete advisory at 500 PM HST. $$ Forecaster Kelly/Berg

...CALVIN STRENGTHENING... ...FORECAST TO BECOME A HURRICANE TONIGHT... As of 11:00 AM HST Wed Jul 12 the center of Calvin was located near 12.8, -113.8 with movement W at 17 mph. The minimum central pressure was 1000 mb with maximum sustained winds of about 65 mph.

Issued at 2100 UTC WED JUL 12 2023 000 WTPZ23 KNHC 122033 TCMEP3 TROPICAL STORM CALVIN FORECAST/ADVISORY NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032023 2100 UTC WED JUL 12 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). TROPICAL STORM CENTER LOCATED NEAR 12.8N 113.8W AT 12/2100Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE WEST OR 275 DEGREES AT 15 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1000 MB MAX SUSTAINED WINDS 55 KT WITH GUSTS TO 65 KT. 50 KT....... 30NE 0SE 0SW 30NW. 34 KT....... 50NE 40SE 30SW 40NW. 12 FT SEAS.. 90NE 0SE 0SW 45NW. 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 113.8W AT 12/2100Z AT 12/1800Z CENTER WAS LOCATED NEAR 12.7N 113.1W FORECAST VALID 13/0600Z 12.9N 115.9W MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 10NE 0SE 0SW 5NW. 50 KT... 40NE 10SE 10SW 30NW. 34 KT... 60NE 50SE 40SW 60NW. FORECAST VALID 13/1800Z 13.1N 118.6W MAX WIND 75 KT...GUSTS 90 KT. 64 KT... 15NE 0SE 0SW 10NW. 50 KT... 50NE 20SE 20SW 40NW. 34 KT... 80NE 60SE 50SW 80NW. FORECAST VALID 14/0600Z 13.6N 121.3W MAX WIND 85 KT...GUSTS 105 KT. 64 KT... 15NE 5SE 5SW 10NW. 50 KT... 60NE 20SE 20SW 50NW. 34 KT...110NE 60SE 60SW 90NW. FORECAST VALID 14/1800Z 14.3N 124.3W MAX WIND 85 KT...GUSTS 105 KT. 64 KT... 20NE 5SE 5SW 20NW. 50 KT... 60NE 30SE 30SW 50NW. 34 KT...110NE 70SE 70SW 90NW. FORECAST VALID 15/0600Z 14.9N 127.3W MAX WIND 80 KT...GUSTS 100 KT. 50 KT... 60NE 30SE 30SW 40NW. 34 KT...120NE 70SE 70SW 90NW. FORECAST VALID 15/1800Z 15.6N 130.4W MAX WIND 75 KT...GUSTS 90 KT. 50 KT... 50NE 30SE 20SW 40NW. 34 KT... 90NE 60SE 60SW 90NW. 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 16/1800Z 16.8N 136.7W MAX WIND 60 KT...GUSTS 75 KT. OUTLOOK VALID 17/1800Z 17.8N 143.7W MAX WIND 50 KT...GUSTS 60 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 12.8N 113.8W NEXT ADVISORY AT 13/0300Z $$ FORECASTER KELLY/BERG

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Wed Jul 12 2023 Valid 122000Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN ILLINOIS/FAR NORTHWESTERN INDIANA...AND PARTS OF EASTERN KANSAS INTO MISSOURI... ...SUMMARY... Severe thunderstorms remain possible across much of Missouri, Illinois, and adjacent portions of the central Plains and Midwest this afternoon through tonight. A few tornadoes should occur this afternoon and evening across parts of northern Illinois into far northwestern Indiana, with a strong tornado possible. Otherwise, damaging winds and large hail should occur with intense thunderstorms that develop, with some potential for significant (75+ mph) severe winds and very large hail across parts of Missouri and Kansas. ...20Z Update... Primary change with this update was to introduce higher tornado probabilities in a narrow corridor across northern IL and far northwestern IN, including Chicago. Recent VWPs from KLOT show impressive low-level shear (0-1 km 35-40+ kt) and enlarged/curved low-level hodographs associated with a focused low-level jet. In the wake of a remnant MCS and lessening precipitation shield, it appears increasingly likely based on recent visible satellite imagery and surface observations that sufficient destabilization to support surface-based convection will occur across this region over the next few hours. Given the very favorable low-level and deep-layer shear available, concern has increased that any supercell which forms in this environment will be capable of producing a tornado. Some potential will exist for a strong tornado as effective SRH strengthens to around 250-350 m2/s2 along/near the developing warm front. The Slight Risk has also been expanded northward in southern Lower MI to account for a small bowing cluster which may develop. No changes have been made to the Enhanced Risk across parts of eastern KS into MO. 18Z sounding from TOP showed warm low/mid-level temperatures and a cap which should continue to inhibit robust convection for at least a couple more hours. Still, intense thunderstorm development is expected later this evening in tandem with a modestly strengthening low-level jet. ..Gleason.. 07/12/2023 .PREV DISCUSSION... /ISSUED 1140 AM CDT Wed Jul 12 2023/ ...Northern IL/southern WI east to northwest OH/southern lower MI... Current MCS continues a general weakening trend based on IR cloud tops, radar trends and recent reports. Air mass recovery in the wake of the morning convection currently appears plausible, aided by a modestly enhanced low-level jet later this afternoon and evening. Steepening mid-level lapse rates will contribute to moderate/pockets of strong MLCAPE this afternoon, and coupled with 40-50 kts of deep-layer shear would result in a favorable parameter space for supercell development by late afternoon/early evening with all severe hazards possible. Will introduce a small 5 percent tornado probability area across this region, where forecast sounding hodograph structure appears most favorable for low-level rotation/tornado potential east of a weak surface low. ...KS/MO/OK this evening... Redevelopment of severe storms appears probable late this afternoon/early evening in the vicinity of an outflow boundary that continues to slow its southward motion across northern portions of KS/MO. Strong/locally extreme MLCAPE is anticipated near/south of this boundary with substantial shear in the cloud-bearing layer. Storms that develop will likely initially possess supercell characteristics with severe hail (possibly significant) and wind, with eventual upscale growth into one or two MCSs capable of potentially significant severe gusts. The Enhanced Risk area has been reoriented based on expected outflow boundary location later this afternoon and a consensus of 12z CAM guidance/HREF ensemble max probabilities. ...IN/OH into New England... A surface quasistationary front currently extends from northern IN into NY and New England. Substantial heating is underway east of the front, which should allow for destabilization and scattered afternoon thunderstorm development. This area lies along the southern fringe of stronger west/southwesterly flow aloft, with 25-35 knots of deep-layer shear. This may be sufficient for a few strong storms later today capable of gusty/damaging winds. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Wed Jul 12 2023 Valid 122000Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN ILLINOIS/FAR NORTHWESTERN INDIANA...AND PARTS OF EASTERN KANSAS INTO MISSOURI... ...SUMMARY... Severe thunderstorms remain possible across much of Missouri, Illinois, and adjacent portions of the central Plains and Midwest this afternoon through tonight. A few tornadoes should occur this afternoon and evening across parts of northern Illinois into far northwestern Indiana, with a strong tornado possible. Otherwise, damaging winds and large hail should occur with intense thunderstorms that develop, with some potential for significant (75+ mph) severe winds and very large hail across parts of Missouri and Kansas. ...20Z Update... Primary change with this update was to introduce higher tornado probabilities in a narrow corridor across northern IL and far northwestern IN, including Chicago. Recent VWPs from KLOT show impressive low-level shear (0-1 km 35-40+ kt) and enlarged/curved low-level hodographs associated with a focused low-level jet. In the wake of a remnant MCS and lessening precipitation shield, it appears increasingly likely based on recent visible satellite imagery and surface observations that sufficient destabilization to support surface-based convection will occur across this region over the next few hours. Given the very favorable low-level and deep-layer shear available, concern has increased that any supercell which forms in this environment will be capable of producing a tornado. Some potential will exist for a strong tornado as effective SRH strengthens to around 250-350 m2/s2 along/near the developing warm front. The Slight Risk has also been expanded northward in southern Lower MI to account for a small bowing cluster which may develop. No changes have been made to the Enhanced Risk across parts of eastern KS into MO. 18Z sounding from TOP showed warm low/mid-level temperatures and a cap which should continue to inhibit robust convection for at least a couple more hours. Still, intense thunderstorm development is expected later this evening in tandem with a modestly strengthening low-level jet. ..Gleason.. 07/12/2023 .PREV DISCUSSION... /ISSUED 1140 AM CDT Wed Jul 12 2023/ ...Northern IL/southern WI east to northwest OH/southern lower MI... Current MCS continues a general weakening trend based on IR cloud tops, radar trends and recent reports. Air mass recovery in the wake of the morning convection currently appears plausible, aided by a modestly enhanced low-level jet later this afternoon and evening. Steepening mid-level lapse rates will contribute to moderate/pockets of strong MLCAPE this afternoon, and coupled with 40-50 kts of deep-layer shear would result in a favorable parameter space for supercell development by late afternoon/early evening with all severe hazards possible. Will introduce a small 5 percent tornado probability area across this region, where forecast sounding hodograph structure appears most favorable for low-level rotation/tornado potential east of a weak surface low. ...KS/MO/OK this evening... Redevelopment of severe storms appears probable late this afternoon/early evening in the vicinity of an outflow boundary that continues to slow its southward motion across northern portions of KS/MO. Strong/locally extreme MLCAPE is anticipated near/south of this boundary with substantial shear in the cloud-bearing layer. Storms that develop will likely initially possess supercell characteristics with severe hail (possibly significant) and wind, with eventual upscale growth into one or two MCSs capable of potentially significant severe gusts. The Enhanced Risk area has been reoriented based on expected outflow boundary location later this afternoon and a consensus of 12z CAM guidance/HREF ensemble max probabilities. ...IN/OH into New England... A surface quasistationary front currently extends from northern IN into NY and New England. Substantial heating is underway east of the front, which should allow for destabilization and scattered afternoon thunderstorm development. This area lies along the southern fringe of stronger west/southwesterly flow aloft, with 25-35 knots of deep-layer shear. This may be sufficient for a few strong storms later today capable of gusty/damaging winds. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0125 PM CDT Wed Jul 12 2023 Valid 131200Z - 141200Z Minor refinements were made to the elevated area across parts of northwest Arizona into far southeast Nevada, based on the latest guidance. Otherwise, the previous forecast remains on track. See the discussion below for more details. ..Karstens.. 07/12/2023 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 12 2023/ ...Synopsis... The Southwest mid-level high will increase amplitude and re-center itself on Thursday across Arizona with much warmer temperatures and gradual drying of the mid-level moisture plume. Winds will generally be below Elevated or Critical thresholds with a few localized breezes and Elevated areas possible. HREF ensemble guidance does include a better chance for more widespread sustained Elevated fire weather conditions across the Arizona/Utah border. Within this region, afternoon relative humidity reductions to 10-15 percent and sustained winds around 15 mph will be possible. An Elevated delineation was added with this outlook to cover this risk. ...Please see www.spc.noaa.gov/fire for graphic product... Read more