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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1049 AM CDT Tue Aug 13 2019 Valid 131700Z - 141200Z ...NO CRITICAL AREAS... The previous forecast remains on track, with no changes or additions made. Please see below for details. ..Squitieri.. 08/13/2019 .PREV DISCUSSION... /ISSUED 1208 AM CDT Tue Aug 13 2019/ ...Synopsis... The synoptic pattern will continue to be generally unfavorable for fire weather concerns today. Weak, quasi-zonal flow aloft will extend across the northern tier of the CONUS today. Additionally, flow across dry areas of the West will remain relatively light outside of localized, terrain-favored areas. Given the minimal fire weather concerns, no highlights will be introduced for this outlook. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1049 AM CDT Tue Aug 13 2019 Valid 131700Z - 141200Z ...NO CRITICAL AREAS... The previous forecast remains on track, with no changes or additions made. Please see below for details. ..Squitieri.. 08/13/2019 .PREV DISCUSSION... /ISSUED 1208 AM CDT Tue Aug 13 2019/ ...Synopsis... The synoptic pattern will continue to be generally unfavorable for fire weather concerns today. Weak, quasi-zonal flow aloft will extend across the northern tier of the CONUS today. Additionally, flow across dry areas of the West will remain relatively light outside of localized, terrain-favored areas. Given the minimal fire weather concerns, no highlights will be introduced for this outlook. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1049 AM CDT Tue Aug 13 2019 Valid 131700Z - 141200Z ...NO CRITICAL AREAS... The previous forecast remains on track, with no changes or additions made. Please see below for details. ..Squitieri.. 08/13/2019 .PREV DISCUSSION... /ISSUED 1208 AM CDT Tue Aug 13 2019/ ...Synopsis... The synoptic pattern will continue to be generally unfavorable for fire weather concerns today. Weak, quasi-zonal flow aloft will extend across the northern tier of the CONUS today. Additionally, flow across dry areas of the West will remain relatively light outside of localized, terrain-favored areas. Given the minimal fire weather concerns, no highlights will be introduced for this outlook. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Tue Aug 13 15:31:03 UTC 2019.

Issued at 800 AM PDT Tue Aug 13 2019 000 WTPZ44 KNHC 131433 TCDEP4 Post-Tropical Cyclone Henriette Discussion Number 7 NWS National Hurricane Center Miami FL EP092019 800 AM PDT Tue Aug 13 2019 The system has been devoid of deep convection for about 12 hours, and therefore, it has degenerated into a remnant low. The post-tropical cyclone is moving through an environment of dry, stable air and over cooler SSTs, which should cause the low to dissipate in a day or so. The motion is west-northwestward, or 285/10 kt. A low-level ridge to the north of the system should steer Henriette's remnants on a west-northwestward to westward heading until dissipation. The official track forecast is close to the multi-model consensus, TVCE. This is the last NHC advisory on Henriette. For additional information on the remnant low please see High Seas Forecasts issued by the National Weather Service, under AWIPS header NFDHSFEPI, WMO header FZPN02 KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php FORECAST POSITIONS AND MAX WINDS INIT 13/1500Z 21.4N 116.1W 25 KT 30 MPH...POST-TROPICAL 12H 14/0000Z 21.8N 117.8W 20 KT 25 MPH...POST-TROP/REMNT LOW 24H 14/1200Z 22.0N 120.0W 15 KT 15 MPH...POST-TROP/REMNT LOW 36H 15/0000Z...DISSIPATED $$ Forecaster Pasch

Issued at 1500 UTC TUE AUG 13 2019 000 FOPZ14 KNHC 131432 PWSEP4 POST-TROPICAL CYCLONE HENRIETTE WIND SPEED PROBABILITIES NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092019 1500 UTC TUE AUG 13 2019 AT 1500Z THE CENTER OF POST-TROPICAL CYCLONE HENRIETTE WAS LOCATED NEAR LATITUDE 21.4 NORTH...LONGITUDE 116.1 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 25 KTS...30 MPH...45 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 12Z TUE 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 12Z TUE 00Z WED 12Z WED 00Z THU 12Z THU 12Z FRI 12Z SAT PERIODS TO TO TO TO TO TO TO 00Z WED 12Z WED 00Z THU 12Z THU 12Z FRI 12Z SAT 12Z SUN FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT $$ FORECASTER PASCH

Issued at 800 AM PDT Tue Aug 13 2019 000 WTPZ34 KNHC 131432 TCPEP4 BULLETIN Post-Tropical Cyclone Henriette Advisory Number 7 NWS National Hurricane Center Miami FL EP092019 800 AM PDT Tue Aug 13 2019 ...HENRIETTE BECOMES A REMNANT LOW... ...THIS IS THE LAST ADVISORY... SUMMARY OF 800 AM PDT...1500 UTC...INFORMATION ---------------------------------------------- LOCATION...21.4N 116.1W ABOUT 410 MI...660 KM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H PRESENT MOVEMENT...WNW OR 285 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 800 AM PDT (1500 UTC), the center of Post-Tropical Cyclone Henriette was located near latitude 21.4 North, longitude 116.1 West. The post-tropical cyclone is moving toward the west-northwest near 12 mph (19 km/h) and a west-northwestward to westward motion is expected over the next day or so. Maximum sustained winds are near 30 mph (45 km/h) with higher gusts. The cyclone is expected to dissipate tomorrow. The estimated minimum central pressure is 1008 mb (29.77 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- This is the last public advisory issued by the National Hurricane Center on this system. For additional information on the remnant low please see High Seas Forecasts issued by the National Weather Service, under AWIPS header NFDHSFEPI, WMO header FZPN02 KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php $$ Forecaster Pasch

...HENRIETTE BECOMES A REMNANT LOW... ...THIS IS THE LAST ADVISORY... As of 8:00 AM PDT Tue Aug 13 the center of Henriette was located near 21.4, -116.1 with movement WNW at 12 mph. The minimum central pressure was 1008 mb with maximum sustained winds of about 30 mph.

Issued at 1500 UTC TUE AUG 13 2019 000 WTPZ24 KNHC 131431 TCMEP4 POST-TROPICAL CYCLONE HENRIETTE FORECAST/ADVISORY NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092019 1500 UTC TUE AUG 13 2019 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. POST-TROPICAL CYCLONE CENTER LOCATED NEAR 21.4N 116.1W AT 13/1500Z POSITION ACCURATE WITHIN 25 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT 10 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1008 MB MAX SUSTAINED WINDS 25 KT WITH GUSTS TO 35 KT. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 21.4N 116.1W AT 13/1500Z AT 13/1200Z CENTER WAS LOCATED NEAR 21.3N 115.6W FORECAST VALID 14/0000Z 21.8N 117.8W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 14/1200Z 22.0N 120.0W...POST-TROP/REMNT LOW MAX WIND 15 KT...GUSTS 25 KT. FORECAST VALID 15/0000Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 21.4N 116.1W THIS IS THE LAST FORECAST/ADVISORY ISSUED BY THE NATIONAL HURRICANE CENTER ON THIS SYSTEM. FOR ADDITIONAL INFORMATION ON THE REMNANT LOW PLEASE SEE HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFEPI AND WMO HEADER FZPN02 KWBC. $$ FORECASTER PASCH

MD 1721 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF WESTERN/CENTRAL NE
Mesoscale Discussion 1721 NWS Storm Prediction Center Norman OK 0856 AM CDT Tue Aug 13 2019 Areas affected...Portions of western/central NE Concerning...Severe potential...Watch unlikely Valid 131356Z - 131530Z Probability of Watch Issuance...20 percent SUMMARY...An isolated large hail risk may continue this morning with ongoing thunderstorms. Watch issuance is unlikely in the short term. DISCUSSION...A pair of elevated supercells has evolved this morning in southern Cherry County NE within a warm air advection regime maximized around 700 mb. Short-term guidance, including the latest run of the RAP, suggests that 25-35 kt of southwesterly flow centered around 700 mb may persist through the rest of the morning. These winds, along with 35-40 kt of effective bulk shear, could maintain storm intensities as they develop southeastward along an instability gradient present across western/central NE. Isolated large hail will remain the primary threat for the next couple of hours given a stable near-surface layer noted on the 12Z sounding from LBF. Regardless, this hail threat will likely remain too isolated to justify watch issuance in the short term (through the rest of the morning). But, the severe threat will likely increase later today across parts of southern/western NE as the atmosphere destabilizes and surface-based storms develop. ..Gleason/Grams.. 08/13/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...CYS... LAT...LON 42580301 42870292 42910242 42280099 41710028 41140025 40740043 40740117 41310187 41990253 42580301 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 AM CDT Tue Aug 13 2019 Valid 131300Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS VA...AND THIS AFTERNOON/EVENING ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS EXTENDING WESTWARD FROM THE MID-ATLANTIC ACROSS TN... ...SUMMARY... Scattered severe thunderstorms with damaging winds are expected across the southern Middle Atlantic into the Tennessee Valley. Severe thunderstorms with very large hail and damaging winds should also develop across the central High Plains. ...Synopsis... The primary larger-scale features today are northern stream troughs moving east-southeastward over Quebec and ND/MN, though a separate/weaker belt of westerlies is located farther south from the central Plains across the OH Valley to the Mid-Atlantic. Within this southern flow belt, diffuse MCVs are progressing east-southeastward over MO/IL and OH/WV, with ongoing convection in multiple clusters through this corridor. The stronger storms along the lower OH River are producing a cold pool and will likely persist until at least late morning, with the southward extent of the outflow likely demarcating the zone of afternoon redevelopment of storms this afternoon across TN. A few damaging gusts will be the main threats with multicell clusters/line segments in an environment of rich low-level moisture and moderate buoyancy along the southern edge of the 25-35 kt midlevel flow. The ongoing convection from southern OH to WV has shown signs of weakening slowly this morning. Still, residual clouds and some rain will slow surface heating from roughly 15-19z across central/northern VA, with the more probable zone of stronger destabilization along the southern fringe of the morning clouds/rain in the vicinity of southern VA. Upstream VWPs reveal 40 kt midlevel flow as low as 4 km above ground level over southern OH/eastern KY/WV, and this somewhat stronger flow will translate over VA this afternoon with the remnant MCV. Will maintain the 30% wind/Enhanced risk area in this update, though the influence of clouds on destabilization through early afternoon will likely modulate additional storm development this afternoon, and potentially reduce the severe threat. ...Central High Plains this afternoon through early tonight... A low-level upslope flow regime will establish today across eastern CO, prior to a weak reinforcing frontal surge overnight. South of an ongoing band of elevated storms driven by midlevel warm advection/frontogenesis, the low levels will warm and MLCAPE is expected to increase to 2000-3000 J/kg by mid-late afternoon. Deep-layer vertical shear will be favorable for supercells from northeast CO/northwest KS northward. Surface-based storm development is expected 21-00z across northeast CO along a surface trough on the northeast edge of the steeper low-level lapse rates and deeper mixing. The initial storms will likely be discrete supercells capable of producing isolated very large hail and perhaps a tornado or two. Convection may grow into a larger cluster this evening and propagate southward into a weak nocturnal low-level jet across far eastern CO/western KS, with a continuing threat for damaging winds into early tonight. ...Upper MS Valley area this afternoon... A midlevel shortwave trough over eastern ND this morning will move southeastward over MN/western WI by this evening. Ascent preceding the midlevel trough will coincide with daytime heating and low-level convergence along a weak northwest-southeast oriented front, which will support thunderstorm development this afternoon. Boundary-layer dewpoints in the 60s and afternoon surface temperatures approaching 80 F will drive MLCAPE of 1000-1500 J/kg, in an environment with effective bulk shear near 40 kt. The net result will be the potential for a few organized/supercell storms capable of producing isolated damaging winds/large hail. An isolated tornado may also occur with storms moving southeastward along the boundary, where low-level shear and vertical vorticity will be larger. ..Thompson/Kerr.. 08/13/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 AM CDT Tue Aug 13 2019 Valid 131300Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS VA...AND THIS AFTERNOON/EVENING ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS EXTENDING WESTWARD FROM THE MID-ATLANTIC ACROSS TN... ...SUMMARY... Scattered severe thunderstorms with damaging winds are expected across the southern Middle Atlantic into the Tennessee Valley. Severe thunderstorms with very large hail and damaging winds should also develop across the central High Plains. ...Synopsis... The primary larger-scale features today are northern stream troughs moving east-southeastward over Quebec and ND/MN, though a separate/weaker belt of westerlies is located farther south from the central Plains across the OH Valley to the Mid-Atlantic. Within this southern flow belt, diffuse MCVs are progressing east-southeastward over MO/IL and OH/WV, with ongoing convection in multiple clusters through this corridor. The stronger storms along the lower OH River are producing a cold pool and will likely persist until at least late morning, with the southward extent of the outflow likely demarcating the zone of afternoon redevelopment of storms this afternoon across TN. A few damaging gusts will be the main threats with multicell clusters/line segments in an environment of rich low-level moisture and moderate buoyancy along the southern edge of the 25-35 kt midlevel flow. The ongoing convection from southern OH to WV has shown signs of weakening slowly this morning. Still, residual clouds and some rain will slow surface heating from roughly 15-19z across central/northern VA, with the more probable zone of stronger destabilization along the southern fringe of the morning clouds/rain in the vicinity of southern VA. Upstream VWPs reveal 40 kt midlevel flow as low as 4 km above ground level over southern OH/eastern KY/WV, and this somewhat stronger flow will translate over VA this afternoon with the remnant MCV. Will maintain the 30% wind/Enhanced risk area in this update, though the influence of clouds on destabilization through early afternoon will likely modulate additional storm development this afternoon, and potentially reduce the severe threat. ...Central High Plains this afternoon through early tonight... A low-level upslope flow regime will establish today across eastern CO, prior to a weak reinforcing frontal surge overnight. South of an ongoing band of elevated storms driven by midlevel warm advection/frontogenesis, the low levels will warm and MLCAPE is expected to increase to 2000-3000 J/kg by mid-late afternoon. Deep-layer vertical shear will be favorable for supercells from northeast CO/northwest KS northward. Surface-based storm development is expected 21-00z across northeast CO along a surface trough on the northeast edge of the steeper low-level lapse rates and deeper mixing. The initial storms will likely be discrete supercells capable of producing isolated very large hail and perhaps a tornado or two. Convection may grow into a larger cluster this evening and propagate southward into a weak nocturnal low-level jet across far eastern CO/western KS, with a continuing threat for damaging winds into early tonight. ...Upper MS Valley area this afternoon... A midlevel shortwave trough over eastern ND this morning will move southeastward over MN/western WI by this evening. Ascent preceding the midlevel trough will coincide with daytime heating and low-level convergence along a weak northwest-southeast oriented front, which will support thunderstorm development this afternoon. Boundary-layer dewpoints in the 60s and afternoon surface temperatures approaching 80 F will drive MLCAPE of 1000-1500 J/kg, in an environment with effective bulk shear near 40 kt. The net result will be the potential for a few organized/supercell storms capable of producing isolated damaging winds/large hail. An isolated tornado may also occur with storms moving southeastward along the boundary, where low-level shear and vertical vorticity will be larger. ..Thompson/Kerr.. 08/13/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 AM CDT Tue Aug 13 2019 Valid 131300Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS VA...AND THIS AFTERNOON/EVENING ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS EXTENDING WESTWARD FROM THE MID-ATLANTIC ACROSS TN... ...SUMMARY... Scattered severe thunderstorms with damaging winds are expected across the southern Middle Atlantic into the Tennessee Valley. Severe thunderstorms with very large hail and damaging winds should also develop across the central High Plains. ...Synopsis... The primary larger-scale features today are northern stream troughs moving east-southeastward over Quebec and ND/MN, though a separate/weaker belt of westerlies is located farther south from the central Plains across the OH Valley to the Mid-Atlantic. Within this southern flow belt, diffuse MCVs are progressing east-southeastward over MO/IL and OH/WV, with ongoing convection in multiple clusters through this corridor. The stronger storms along the lower OH River are producing a cold pool and will likely persist until at least late morning, with the southward extent of the outflow likely demarcating the zone of afternoon redevelopment of storms this afternoon across TN. A few damaging gusts will be the main threats with multicell clusters/line segments in an environment of rich low-level moisture and moderate buoyancy along the southern edge of the 25-35 kt midlevel flow. The ongoing convection from southern OH to WV has shown signs of weakening slowly this morning. Still, residual clouds and some rain will slow surface heating from roughly 15-19z across central/northern VA, with the more probable zone of stronger destabilization along the southern fringe of the morning clouds/rain in the vicinity of southern VA. Upstream VWPs reveal 40 kt midlevel flow as low as 4 km above ground level over southern OH/eastern KY/WV, and this somewhat stronger flow will translate over VA this afternoon with the remnant MCV. Will maintain the 30% wind/Enhanced risk area in this update, though the influence of clouds on destabilization through early afternoon will likely modulate additional storm development this afternoon, and potentially reduce the severe threat. ...Central High Plains this afternoon through early tonight... A low-level upslope flow regime will establish today across eastern CO, prior to a weak reinforcing frontal surge overnight. South of an ongoing band of elevated storms driven by midlevel warm advection/frontogenesis, the low levels will warm and MLCAPE is expected to increase to 2000-3000 J/kg by mid-late afternoon. Deep-layer vertical shear will be favorable for supercells from northeast CO/northwest KS northward. Surface-based storm development is expected 21-00z across northeast CO along a surface trough on the northeast edge of the steeper low-level lapse rates and deeper mixing. The initial storms will likely be discrete supercells capable of producing isolated very large hail and perhaps a tornado or two. Convection may grow into a larger cluster this evening and propagate southward into a weak nocturnal low-level jet across far eastern CO/western KS, with a continuing threat for damaging winds into early tonight. ...Upper MS Valley area this afternoon... A midlevel shortwave trough over eastern ND this morning will move southeastward over MN/western WI by this evening. Ascent preceding the midlevel trough will coincide with daytime heating and low-level convergence along a weak northwest-southeast oriented front, which will support thunderstorm development this afternoon. Boundary-layer dewpoints in the 60s and afternoon surface temperatures approaching 80 F will drive MLCAPE of 1000-1500 J/kg, in an environment with effective bulk shear near 40 kt. The net result will be the potential for a few organized/supercell storms capable of producing isolated damaging winds/large hail. An isolated tornado may also occur with storms moving southeastward along the boundary, where low-level shear and vertical vorticity will be larger. ..Thompson/Kerr.. 08/13/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 AM CDT Tue Aug 13 2019 Valid 131300Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS VA...AND THIS AFTERNOON/EVENING ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS EXTENDING WESTWARD FROM THE MID-ATLANTIC ACROSS TN... ...SUMMARY... Scattered severe thunderstorms with damaging winds are expected across the southern Middle Atlantic into the Tennessee Valley. Severe thunderstorms with very large hail and damaging winds should also develop across the central High Plains. ...Synopsis... The primary larger-scale features today are northern stream troughs moving east-southeastward over Quebec and ND/MN, though a separate/weaker belt of westerlies is located farther south from the central Plains across the OH Valley to the Mid-Atlantic. Within this southern flow belt, diffuse MCVs are progressing east-southeastward over MO/IL and OH/WV, with ongoing convection in multiple clusters through this corridor. The stronger storms along the lower OH River are producing a cold pool and will likely persist until at least late morning, with the southward extent of the outflow likely demarcating the zone of afternoon redevelopment of storms this afternoon across TN. A few damaging gusts will be the main threats with multicell clusters/line segments in an environment of rich low-level moisture and moderate buoyancy along the southern edge of the 25-35 kt midlevel flow. The ongoing convection from southern OH to WV has shown signs of weakening slowly this morning. Still, residual clouds and some rain will slow surface heating from roughly 15-19z across central/northern VA, with the more probable zone of stronger destabilization along the southern fringe of the morning clouds/rain in the vicinity of southern VA. Upstream VWPs reveal 40 kt midlevel flow as low as 4 km above ground level over southern OH/eastern KY/WV, and this somewhat stronger flow will translate over VA this afternoon with the remnant MCV. Will maintain the 30% wind/Enhanced risk area in this update, though the influence of clouds on destabilization through early afternoon will likely modulate additional storm development this afternoon, and potentially reduce the severe threat. ...Central High Plains this afternoon through early tonight... A low-level upslope flow regime will establish today across eastern CO, prior to a weak reinforcing frontal surge overnight. South of an ongoing band of elevated storms driven by midlevel warm advection/frontogenesis, the low levels will warm and MLCAPE is expected to increase to 2000-3000 J/kg by mid-late afternoon. Deep-layer vertical shear will be favorable for supercells from northeast CO/northwest KS northward. Surface-based storm development is expected 21-00z across northeast CO along a surface trough on the northeast edge of the steeper low-level lapse rates and deeper mixing. The initial storms will likely be discrete supercells capable of producing isolated very large hail and perhaps a tornado or two. Convection may grow into a larger cluster this evening and propagate southward into a weak nocturnal low-level jet across far eastern CO/western KS, with a continuing threat for damaging winds into early tonight. ...Upper MS Valley area this afternoon... A midlevel shortwave trough over eastern ND this morning will move southeastward over MN/western WI by this evening. Ascent preceding the midlevel trough will coincide with daytime heating and low-level convergence along a weak northwest-southeast oriented front, which will support thunderstorm development this afternoon. Boundary-layer dewpoints in the 60s and afternoon surface temperatures approaching 80 F will drive MLCAPE of 1000-1500 J/kg, in an environment with effective bulk shear near 40 kt. The net result will be the potential for a few organized/supercell storms capable of producing isolated damaging winds/large hail. An isolated tornado may also occur with storms moving southeastward along the boundary, where low-level shear and vertical vorticity will be larger. ..Thompson/Kerr.. 08/13/2019 Read more

000
ABPZ20 KNHC 131141
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Tue Aug 13 2019

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

The National Hurricane Center is issuing advisories on recently
downgraded Tropical Depression Henriette, located a few hundred
miles west-southwest of the southern tip of the Baja California
peninsula.

Disorganized showers and thunderstorms located about 1100 miles
southwest of the southern tip of the Baja California peninsula are
associated with an elongated trough of low pressure. Environmental
conditions are forecast to be conducive for gradual development
during the next few days, and a tropical depression is likely to
form later this week while the system moves west-northwestward at
10 to 15 mph.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...high...70 percent.

A broad area of low pressure is forecast to form south or
southeast of the southeastern coast of Mexico late this week.
Environmental conditions are expected to be conducive for gradual
development of the system over the weekend.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Pasch

000
ABNT20 KNHC 131122
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Tue Aug 13 2019

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Tropical cyclone formation is not expected during the next 5 days.

$$
Forecaster Avila

5-Day Uncertainty Track last updated Tue, 13 Aug 2019 08:33:37 GMT


Wind Speed Probabilities last updated Tue, 13 Aug 2019 15:24:25 GMT

...HENRIETTE WEAKENING QUICKLY... ...EXPECTED TO BECOME A REMNANT LOW LATER TODAY... As of 2:00 AM PDT Tue Aug 13 the center of Henriette was located near 21.1, -115.2 with movement WNW at 13 mph. The minimum central pressure was 1008 mb with maximum sustained winds of about 30 mph.

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0245 AM CDT Tue Aug 13 2019 Valid 161200Z - 211200Z ...DISCUSSION... An area of moderate westerlies aloft will remain over the northern CONUS on Fri/D4 and Sat/D5, but will lift north into Canada during the Sun/D6-Sat/D7 period. During that time, an upper ridge will build over the West with the high centered over AZ. On Fri/D4, the GFS indicates a low-amplitude shortwave trough moving from WY across SD, NE, and into IA, with an associated cold front, but the ECMWF is less amplified with this feature. In addition, there are major discrepancies with latitudinal placement of the larger instability (KS vs NE). As such, predictability is too low for Friday, though severe weather is possible (mainly wind gusts) in this general region. For the period from Sat/D5 into Sun/D6, ample moisture and instability will remain from the central Plains into the mid and upper MS Valley as a larger trough amplification occurs over south-central Canada, extending south into the northern Plains. Aside from timing issues amongst the various models with this trough, daily cycles of thunderstorms further decrease predictability regarding the best threat corridors. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0245 AM CDT Tue Aug 13 2019 Valid 161200Z - 211200Z ...DISCUSSION... An area of moderate westerlies aloft will remain over the northern CONUS on Fri/D4 and Sat/D5, but will lift north into Canada during the Sun/D6-Sat/D7 period. During that time, an upper ridge will build over the West with the high centered over AZ. On Fri/D4, the GFS indicates a low-amplitude shortwave trough moving from WY across SD, NE, and into IA, with an associated cold front, but the ECMWF is less amplified with this feature. In addition, there are major discrepancies with latitudinal placement of the larger instability (KS vs NE). As such, predictability is too low for Friday, though severe weather is possible (mainly wind gusts) in this general region. For the period from Sat/D5 into Sun/D6, ample moisture and instability will remain from the central Plains into the mid and upper MS Valley as a larger trough amplification occurs over south-central Canada, extending south into the northern Plains. Aside from timing issues amongst the various models with this trough, daily cycles of thunderstorms further decrease predictability regarding the best threat corridors. Read more