Aikyam-Lab/Synoptic-Bench huggingface dataset:
A SFC TROF OF LOW PRESSURE WILL ORIENT ITSELF ALONG THE NM AND TX STATE LINE THIS AFTERNOON. WHICH WILL LIKELY IMPINGE ON A SWD MOVG COLD FRONT. WITH MINOR DIFFERENCES ON COLD FRONTAL TIMING. SFC COLD FRONT WILL SETTLE TO A POSITION JUST SOUTH AND WEST OF THE FCST AREA ON WEDNESDAY.
THE COLD FRONT IS THEN EXPECTED TO PUSH INTO SOUTH FLORIDA LATER TODAY WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING AND PUSHING INTO THE AREA AHEAD OF THE FRONT BEGINNING LATE THIS MORNING. COVERAGE OF SHOWERS AND THUNDERSTORMS SHOULD BEGIN TO SLOWLY DECREASE TOWARD THE END OF THE WEEK AND INTO THE WEEKEND AS STRONG UPPER RIDGING IS STILL EXPECTED TO BUILD INTO THE EASTERN GULF OF MEXICO.
WINDY CONDITIONS WILL BE THE HIGHLIGHT FOR TUESDAY AS UPPER AND LOWER LEVEL JETS INTENSIFY ACROSS IL. THE UPPER TROUGH WILL REMAIN ENTRENCHED ACROSS THE GREAT LAKES FOR THE REST OF THE WEEK, PROVIDING SUSTAINED NW FLOW AND COOLER THAN NORMAL CONDITIONS. REINFORCING COLD AIR BEHIND THE COLD FRONT WILL KEEP HIGHS FOR THE REMAINDER OF THE WEEK IN THE UPPER 50S TO NEAR 60, WITH OVERNIGHT LOWS IN THE 30S.
AND A W COAST RIDGE THAT MAKES SLOW BY STEADY PROGRESS INTO THE INTERMOUNTAIN W. THIS TROF WILL TURN SE AND HEAD INTO THE MIDWEST TONIGHT. ALSO A CLOSED LOW WILL UNDERCUT AN AMPLIFIED RIDGE TO THE WEST. HIGH PRESSURE BUILDS IN BEHIND A COLD FRONT. THE SURFACE PRESSURE GRADIENT IS RATHER STRONG BEHIND THE COLD FRONT AND I HAVE BUMPED UP WIND SPEEDS MANUALLY DIRECTLY BEHIND THE COLD FRONT PASSAGE TUESDAY NIGHT. WIND SHOULD BECOME RELATIVELY LIGHT TOWARD DAWN FOR MOST AREAS AS THE INCREASED WIND SPEED WILL BE PRIMARILY JUST BEHIND THE COLD FRONT.
I HAVE KEPT MOST OF THE HIGHER POP VALUES ALONG AND SOUTH OF HIGHWAY 50 AS THIS AREA IS CLOSER IN PROXIMITY TO THE AFOREMENTIONED FRONTOGENESIS. TOMORROW: WARMER TEMPERATURES ARE IN STORE FOR TOMORROW. A WEAK WARM FRONT MOVES NORTHWARD TOMORROW, WITH SLIGHTLY WARMER 850-HPA TEMPS IN ITS WAKE. BY TUESDAY EVENING, A DEEP UPPER LEVEL LOW PRESSURE SYSTEM WILL BE OVER THE WESTERN GREAT LAKES REGION. WEAK UPPER LEVEL DISTURBANCES MOVING FROM THE ROCKIES OVER A WEAK SOUTHERN PLAINS RIDGE WILL COMBINE WITH ISENTROPIC LIFT OVER THE FRONTAL ZONE TO BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS TO PORTIONS OF SOUTHWEST AND SOUTH CENTRAL KANSAS.
THE SHORT TERM OFFERS MORE OF THE SAME OVER THE NEXT FEW DAYS WITH A FETCH THAT ROUNDS THE LOW TO THE EAST. THE CANADIAN HIGH PRESSURE RIDGE CONTINUES TO SLOWLY BUILD FOR WEDNESDAY.
617 AM EDT TUE APR 21 2015 A COLD FRONT WILL MOVE THROUGH THE AREA TODAY WITH SHOWERS AND MAYBE A THUNDERSTORM.
THE HIGHEST PROBABILITY OF FOG WILL BE FOR EASTERN AND SOUTHERN PORTIONS OF THE LARAMIE VALLEY. LOOKS LIKE ENOUGH INSTABILITY IN THE THETA E RIDGE ACROSS OUR FAR SOUTHWEST COUNTIES FOR ISOLATED TO WIDELY SCATTERED EARLY EVENING SHOWERS OVER SOUTHERN CARBON AND ALBANY COUNTIES. TRANSITORY RIDGING ALOFT MOVES OVERHEAD.
646 AM EDT TUE APR 21 2015 HIGH PRESSURE WILL BUILD OVER THE AREA TODAY BRINGING FAIR AND DRIER CONDITIONS.
ALTHOUGH CANNOT RULE OUT A FEW MORE STORMS DEVELOPING AHEAD OF A COLD FRONT THAT IS PUSHING ACROSS THE AREA. THE COLD FRONT CAUSING ALL THIS TROUBLE WILL MOVE THROUGH THE REMAINDER OF THE CWFA BY THE MID TO LATE EVENING. HIGH PRESSURE AND A DRIER AIRMASS WILL SETTLE OVER THE CWFA. WEAK SHORT WAVES IN THE WESTERLY UPPER FLOW AND A WEAK COLD FRONT BRING AT LEAST A SLIGHT CHANCE FOR PRECIPITATION BACK INTO THE NORTH BY LATE WEDNESDAY.
609 AM EDT TUE APR 21 2015 A TROUGH/SECONDARY COLD FRONT WILL MOVE ACROSS THE AREA LATE TODAY USHERING IN MUCH COOLER CONDTIONS. WILL CONTINUE WITH CHANCE POPS ACROSS THE FORECAST AREA THIS EVENING INTO THE OVERNIGHT AS THE TROUGH (OR WEAK FRONT) SWINGS SOUTH OF THE AREA. COOLER AIRMASS MOVES OVER THE AREA BY WEDNESDAY MORNING.
1158 PM MDT MON APR 20 2015 DURING THE EVENING AND INTO THE OVERNIGHT HOURS A WEAK UPPER LEVEL SHORT WAVE TROUGH MOVES ACROSS THE AREA. OVERNIGHT TEMPERATURES WILL BE COOL AGAIN WITH SOME AREAS EXPECTED TO BE NEAR FREEZING AROUND SUNRISE. DAYTIME TEMPERATURES ON TUESDAY WILL CONTINUE TO WARM INTO THE LOWER 70S AHEAD OF THE NEXT COLD FRONT EXPECTED TO PUSH INTO THE AREA BY TUESDAY EVENING. SOUTHEASTERLY RETURN FLOW GETS UNDERWAY IN THE LOW LEVELS WEDNESDAY WITH INCREASING CLOUDS.
143 AM CDT TUE APR 21 2015 A PASSING WAVE IN THE MEAN BROAD CYCLONE'S TROF WILL ALLOW FRONTOGENETIC FORCING/ASSOCIATED POPS TO REDEVELOP AND SPREAD ALONG THE LOWER OHIO RIVER VALLEY LATER TODAY-TONIGHT. SO POPS WILL END WEST TO EAST AS HIGH PRESSURE BUILDS ACROSS THE MIDDLE AND UPPER MISSISSIPPI VALLEY AT THE SURFACE. SOME DIRTY OVERRUN OF THE HIGH FROM THE SOUTH MAY WARRANT A SMALL CHANCE POP REAPPEARANCE THERE WED NIGHT. OTHERWISE WE'LL CLOSE OUT THE SHORT TERM MAINLY DRY/UNDER THE INFLUENCE OF THE HIGH. WEAKER SYSTEMS WILL AFFECT THE LOWER 48. SHOULD BE A MID LEVEL TROF/LOW MOVING FROM THE SW U.
Today will be the warmest day of the week as the high pressure ridge shifts directly over the Northern Rockies. However this all appears to change on Wednesday as a rather strong and significantly colder cut of low pressure system drifts into Washington and towards Montana. The passage of a very slow moving cold front ahead of this upper low will team with peak heating to produce widespread showers and thunderstorms across much of the Northern Rockies. Models continue to struggle with the path and strength of the cut-off low as it exits into Canada.
651 AM EDT TUE APR 21 2015 A COLD FRONT WILL MOVE THROUGH THE AREA TODAY WITH SHOWERS AND MAYBE A THUNDERSTORM.
HIGH PRESSURE OVER THE SOUTHEAST U. WEST WINDS VEER AROUND TO THE EAST TONIGHT AS THE RIDGE AXIS OF THE HIGH PRESSURE REMAINS NORTH OF CENTRAL FLORIDA. PSG OF MINOR DISTURBANCES EMBEDDED IN UPR FLOW COMBINED WITH SOMEWHAT FAVORABLE MOISTURE AND HEATING WL ALLOW FOR DEVELOPMENT OF DIURNALLY FOCUSED SHOWERS AND ISOLD TS WED-THU WITH DECREASING CHCS FRI-SAT AS A TRANSITORY RIDGE OVER THE GULF BUILDS EWD OVER THE REGION. HIGH PRESSURE BUILDS IN FROM THE SOUTHEAST U.
416 AM MDT TUE APR 21 2015 CORRECTED FOR TYPO THE PATTERN OVER THE WEST FEATURES A RIDGE OVER THE PACIFIC NORTHWEST ABOVE A CLOSED LOW OFF THE COAST OF SOUTHERN CALIFORNIA.
236 AM MST TUE APR 21 2015 THE REGION WILL GET ONE MORE DAY OF ABOVE NORMAL TEMPERATURES BEFORE A BROAD AREA OF LOW PRESSURE BRINGS CHANGES STARTING ON WEDNESDAY.
436 AM EDT TUE APR 21 2015 A COLD FRONT WILL MOVE THROUGH THE AREA TODAY WITH SHOWERS AND MAYBE A THUNDERSTORM.
FLIGHT WEATHER SHOULD REMAIN VFR THROUGH THE PERIOD WITH SOME DRIER AIR BUILDING IN ON WESTERLY FLOW IN THE LOW LEVELS. THERE MAY BE A COUPLE PERIODS WHERE THERE WILL BE SOME BKN AC AS WEAK SHORT WAVE ENERGY ROTATES THROUGH THE BASE OF A LONG WAVE TROUGH HOLDING ITS POSITION OVER THE GREAT LAKES BUT NO CEILINGS EXPECTED BELOW SIX THOUSAND FEET.
352 AM EDT TUE APR 21 2015 A TROUGH/SECONDARY COLD FRONT WILL MOVE ACROSS THE AREA LATE TODAY USHERING IN MUCH COOLER CONDTIONS. WILL CONTINUE WITH CHANCE POPS ACROSS THE FORECAST AREA THIS EVENING INTO THE OVERNIGHT AS THE TROUGH (OR WEAK FRONT) SWINGS SOUTH OF THE AREA. COOLER AIRMASS MOVES OVER THE AREA BY WEDNESDAY MORNING.
THE COLD FRONT WHICH HELPED DRIVE MUCH OF THE STRONG CONVECTIVE ACTIVITY EARLY MON. AS HIGH PRESSURE MAKES ITS WAY EWD ACROSS THE GULF REGION. BEFORE WARMER CONDITIONS/MOISTURE GRADUALLY RETURN TO THE AREA WED. HIGH PRESSURE AND A DRY AIRMASS ACROSS THE REGION WILL PROVIDE FOR VFR CONDITIONS THRU THE FCST PERIOD.
144 AM EDT TUE APR 21 2015 A WAVE OF LOW PRESSURE WILL MOVE ACROSS THE REGION OVERNIGHT. WEAK HIGH PRESSURE WILL FOLLOW FOR TUESDAY. A COLD FRONT WILL PASS ON WEDNESDAY. THIS WILL KEEP THE WARM FRONT JUST SOUTH OF MOST OF THE LCL AREA. TSTMS DEVELOPED NEAR THE TRIPLE POINT OF THE APPROACHING LOW EAST OF THE OCCLUDED FRONT AND ALONG AND NORTH OF THE WARM FRONT. HIGHS COULD BE A LITTLE WARMER THAN FCST ON WED DEPENDING ON THE AMT OF CLOUD COVER AND SPEED OF THE DEVELOPING SHWRS AHEAD OF THE FRONT. LIFR/VLIFR CONDS IN FOG/DRIZZLE UNTIL COLD FRONT BEGINS TO WORK ITS WAY ACROSS THE TERMINALS IN THE MORNING. CONDS IMPROVE TO VFR BEHIND THE PASSAGE OF THE COLD FRONT.
STILL A DECENT HEIGHT/PRESSURE GRADIENT IN PLACE BETWEEN LARGELY BAROTROPIC LOW PRESSURE NEAR JAMES BAY AND ANTICYCLONE ACROSS THE GULF COAST. DEGREE OF MOISTURE AVAILABLE IS VERY MUCH IN QUESTION AND REMAINS A SIGNIFICANT LIMITING FACTOR FOR PRECIP DEVELOPMENT BUT SHREDS OF VORTICITY ROTATING AROUND LARGE CLOSED LOW COULD PROVIDE JUST ENOUGH MIDLEVEL CONVERGENCE/SATURATION TO WARRANT A FEW ISOLATED SPRINKLES/SHOWERS. HWVR POTENTIAL PITFALL EXISTS IN FRI NIGHT-SAT TIME FRAME W/BOTH HANDLING/PLACEMENT OF NWWD ORIENTED MID LVL TROUGH AXIS EXTENDING BACK INTO THE NRN PLAINS AND NEWD EJECTION OF SRN STREAM SW LOCATED OFF THE SRN CA COAST THIS MORNING. LOW LEVEL DRY AIR ADVECTION IN THE WAKE OF LARGE CYCLONE OVER ONTARIO WILL ENSURE VFR CONDITIONS THROUGH THE PERIOD.
246 AM EDT TUE APR 21 2015 LOW PRESSURE WILL APPROACH FROM THE SOUTHWEST OVERNIGHT AND CROSS THE REGION LATER TUESDAY. UPPER LEVEL LOW PRESSURE FROM THE GREAT LAKES WILL THEN KEEP UNSETTLED CONDITIONS THROUGH THE LATE WEEK. XCPT THE HIGHEST CNTRL ME HIGHLANDS AND MT KATAHDIN TRRN.
407 AM CDT TUE APR 21 2015 A CONTINENTAL TYPE AIRMASS WILL CONTINUE ACROSS THE FORECAST AREA TODAY AS HIGH PRESSURE AT THE SURFACE MOVES ACROSS THE LOWER MISSISSIPPI VALLEY.
TROUGH APPROACHING FROM THE PACIFIC NORTHWEST WILL INCREASE AVAILABLE MOISTURE AND MAKE THE ATMOSPHERE MORE AND MORE UNSTABLE FROM DAY TO DAY UNTIL IT ARRIVES WED NIGHT.
159 AM EDT TUE APR 21 2015 A COLD FRONT WILL FINISH CROSSING THE REGION OVERNIGHT. WARM SECTOR IS MANAGING TO SNEAK IN JUST AHEAD WITH DEWPOINTS NOW BUMPING INTO THE LOW-MID 50S. SHEAR WILL CONTRIBUTE TO THIS BY ALLOWING FOR A FEW ROTATING MESOCYCLONES. SHOWERS AND THUNDERSTORMS ARE MOVING INTO WESTERN NYS ATTM AS THE UPPER LEVEL TROF BEGINS MOVING INTO THE REGION.
409 AM MDT TUE APR 21 2015 THE PATTERN OVER THE WEST FEATURES A RIDGE OVER THE PACIFIC NORTHWEST ABOVE A CLOSE LOW OFF THE COAST OF SOUTHERN CALIFORNIA.
151 AM EDT TUE APR 21 2015 LOW PRESSURE WILL LINGER NORTH OF THE GREAT LAKES THROUGH WEDNESDAY.
SFC RIDGING CONTINUES TO EDGE INTO THE REGION FROM THE WEST ALLOWING WINDS TO DECOUPLE QUICKLY WITH MOST SITES NEAR CALM AS OF 02Z.
WILL LIKELY BE A BIT COOLER WHEN IT DOES RAIN AND WARMER WHEN IT DOES NOT. AS A STRONG COLD FRONT APPROACHES FROM THE NORTH.
353 AM CDT Tue Apr 21 2015 Deep upper low over the Great Lakes was making slow eastward progress early this morning with likely a few small scale waves rotating around it through the Northern and Central Plains. At least minor amounts of EPV along the moist layer allowing some showers to form aloft, with weak returns on radar showing some very light precip reaching to the lower troposphere. Cold front via a stronger wave rotating around the low arrives this evening and makes quick south progress through the state tonight.
HIGH PRESSURE ALOFT WILL BUILD EAST INTO THE GREAT BASIN TODAY. A LOW PRESSURE SYSTEM OFF THE SOUTHERN CALIFORNIA COAST WILL ALSO MOVE INLAND TODAY.
EARLY MORNING WATER VAPOR IMAGERY/RAP ANALYSIS SHOWED THE CIRCULATION AROUND A CLOSED LOW SPINNING OVER THE UPPER MISSISSIPPI VALLEY AND WESTERN GREAT LAKES REGION. ANOTHER SLIGHTLY COOLER THAN NORMAL AND LOW RELATIVE HUMIDITY DAY IS ON TAP AS SITES TOP OUT IN THE MID TO UPPER 70S. THIS WILL HELP PROVIDE WARMER MORNING LOWS BUT ANOTHER NIGHT OF COOLER THAN NORMAL TEMPERATURES IS EXPECTED.
THE CLOSED UPPER LOW WAS MEANDERING AROUND NW MN AT 19Z WITH EMBEDDED PIECES OF SHORT WAVE ENERGY ROTATING THROUGH THE FORECAST AREA. EXPECT MORE PIECES OF SHORT WAVE ENERGY TO MOVE THROUGH THE FORECAST AREA AS THE UPPER LOW TRAVELS TO THE WESTERN EDGE OF UPPER MI. THE UPPER LOW DRIFTS OVER TO EASTERN LAKE SUPERIOR BY 00Z WEDNESDAY.
617 AM EDT TUE APR 21 2015 LOW PRESSURE WILL DRIVE AN OCCLUDED FRONT ACROSS THE REGION TODAY PRECEDED BY LOCALLY HEAVY RAIN AND SCATTERED THUNDERSTORMS.
311 AM MDT TUE APR 21 2015 NORTHWEST FLOW CONTINUES ACROSS THE CENTRAL PLAINS THROUGH TONIGHT AHEAD OF A RIDGE BUILDING INTO THE ROCKIES.
312 AM CDT TUE APR 21 2015 LATEST SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES ACROSS THE MID STATE WITH OBS INDICATING COOLER TEMPERATURES THAN WE HAVE SEEN IN A WHILE WITH CURRENT READINGS IN THE 40S. 00Z MODELS INDICATE SOUTHWEST FLOW WILL INCREASE AT THE SURFACE AND ALOFT TODAY AHEAD OF A COLD FRONT APPROACHING FORM THE NORTHWEST.
500 AM MDT TUE APR 21 2015 12Z TAF CYCLE WEAK UPPER RIDGE WITH RESIDUAL MID LEVEL MOISTURE TO RESULT IN ISOLD CONVECTION AFT 18Z MAINLY OVR HIGHER TERRAIN AND NE NM WHERE A SURFACE BOUNDARY WILL EVENTUALLY MATERIALIZE.
342 AM CDT TUE APR 21 2015 UPPER LEVEL LOW NEAR DULUTH WILL BEGIN TO MOVE EAST TODAY. WITH THE CLOUDS HAVING BEEN SHIFTING A BIT SOUTHWEST WITH TIME DURING THE NIGHT AS AN IMPULSE DROPS BACK SOUTH AROUND THE UPPER LOW. AS THE UPPER LOW MOVES EAST LOOK FOR THE CLOUDS TO GRADUALLY CLEAR FROM WEST TO EAST THIS AFTN INTO ERN ND AND THEN THIS EVENING INTO NW MN.
150 AM EDT TUE APR 21 2015 HIGH PRESSURE WILL BUILD OVER THE AREA TODAY BRINGING FAIR AND DRIER CONDITIONS.
357 AM CDT TUE APR 21 2015 AN ARCTIC COLD FRONT ACROSS NORTH DAKOTA WILL BACK INTO THE FCST AREA THIS AFTN PRODUCING SOME CLOUDINESS. BY 12Z WEDNESDAY A SMALL AREA OF HIGH PRESSURE HAS SETTLED OVER NCNTL NEB WHICH SHOULD PRODUCE LOWS IN THE 20S. THE MODELS SUGGEST ANY CLOUD COVER WOULD LIE ACROSS THE PANHANDLE AND SOUTHWEST NEB WHICH WOULD HOLD UP LOWS IN THE LOWER 30S. THE RADAR RETURNS ACROSS NORTH DAKOTA MOVE EAST OF THE FCST AREA IN THE NAM MODEL WHILE THE HRRR SHOWS TOO MUCH DRY AIR IN THE LOWER LEVELS FOR ANYTHING MORE THAN SPRINKLES THIS AFTN AND TONIGHT. MEANWHILE AN UPPER LEVEL LOW LIFTS TOWARDS THE DESERT SW.
EARLY THIS MORNING THE COLD FRONT ACROSS SE GA AND NE FL WILL CONTINUE TO SHIFT SEWD WITH ASSOCD RICH LOW LEVEL MOISTURE.
300 AM EDT TUE APR 21 2015 HIGH PRESSURE WILL BUILD OVER THE AREA TODAY BRINGING FAIR AND DRIER CONDITIONS.
THE LARGE UPPER LOW WILL SLOWLY MOVE ACROSS THE NRN GREAT LAKES AND ONTARIO CANADA THROUGH THE PERIOD. THE PRESSURE GRADIENT AND STEEP LOW LEVEL LAPSE WILL MAINTAIN BRISK WLY WINDS THAT WILL TURN NWLY TNT WITH THE PASSAGE OF ANOTHER COLD FRONT.
ANOTHER LOW PRESSURE SYSTEM WILL MOVE SOUTH ALONG THE COAST WEDNESDAY AND THROUGH THE END OF THE WEEK. THE NEXT TROUGH WAS ALONG 136W THIS MORNING. WITH THE THREAT OF CONVECTION CONTINUING THROUGH WEDNESDAY AS AN UPPER- LEVEL LOW CLOSES OFF IN THE BASE OF THE TROUGH WEST OF BAJA CALIFORNIA.
120 AM EDT TUE APR 21 2015 LOW PRESSURE WILL APPROACH FROM THE SOUTHWEST OVERNIGHT AND CROSS THE REGION LATER TUESDAY. UPPER LEVEL LOW PRESSURE FROM THE GREAT LAKES WILL THEN KEEP UNSETTLED CONDITIONS THROUGH THE LATE WEEK. XCPT THE HIGHEST CNTRL ME HIGHLANDS AND MT KATAHDIN TRRN.
429 AM EDT TUE APR 21 2015 UPPER AIR PATTERN CONSISTS OF A 500 MB LOW OVER THE UPPER GREAT LAKES EMBEDDED IN A TROUGH ACROSS THE GREAT LAKES REGION. LOOKS LIKE THERE COULD BE SOME INSTABILITY SHOWERS TODAY WITH THE UPPER LOW OVERHEAD AND ALSO A LAKE BREEZE CONTRIBUTION IN THE EASTERN CWA WHICH WILL ENHANCE THE SHOWERS AND THIS WAS ALREADY COVERED IN THE POPS. NORTHWEST LAKE EFFECT SNOW BELTS WILL HAVE THE HIGHEST POPS FOR THIS FORECAST PERIOD AND THERE WILL BE SOME ACCUMULATING SNOW ON THE GRASS THIS FORECAST PERIOD WITH 2 INCHES IN THE WEST FOR TODAY AND UP TO 3 INCHES TONIGHT.
TODAY THROUGH WEDNESDAY NIGHT CURRENT SURFACE ANALYSIS SHOWS A COLD FRONT STRETCHING FROM WESTERN ND TO SOUTHEAST SD. WITH HIGH PRESSURE OVER THE CANADIAN PRAIRIE PROVS. UPPER LEVEL ANALYSIS SHOWS LARGE TROF COVERING MUCH OF THE CENTRAL AND EASTERN CONUS. SOME COOLER AIR WILL BACK INTO NORTHERN AND EASTERN PORTIONS OF THE CWA TODAY AS THE COLD FRONT SLIDES SLOWLY SOUTHWEST ACROSS THE CWA DURING THE DAY. HIGHS SHOULD GENERALLY RANGE FROM AROUND 50 ACROSS PORTIONS OF FAR NORTHWEST SD TO THE LOWER 60S ACROSS NORTHEAST WY AND FAR SOUTHWEST SD. ALLOWING WARMER AIR TO PUSH FURTHER NORTH AND EAST DURING THE DAY. WINDS WILL TURN SOUTHEASTERLY LATER TONIGHT AND PERSIST INTO WEDNESDAY AS HIGH PRESSURE PASSES TO THE NORTH AND EAST OF THE REGION.
313 AM CDT TUE APR 21 2015 A PASSING WAVE IN THE MEAN BROAD CYCLONE'S TROF WILL ALLOW FRONTOGENETIC FORCING/ASSOCIATED POPS TO REDEVELOP AND SPREAD ALONG THE LOWER OHIO RIVER VALLEY LATER TODAY-TONIGHT. SO POPS WILL END WEST TO EAST AS HIGH PRESSURE BUILDS ACROSS THE MIDDLE AND UPPER MISSISSIPPI VALLEY AT THE SURFACE. SOME DIRTY OVERRUN OF THE HIGH FROM THE SOUTH MAY WARRANT A SMALL CHANCE POP REAPPEARANCE THERE WED NIGHT. OTHERWISE WE'LL CLOSE OUT THE SHORT TERM MAINLY DRY/UNDER THE INFLUENCE OF THE HIGH.
1240 PM CDT TUE JUL 21 2015 HIGH PRESSURE BUILDING INTO THE MIDWEST BEHIND A COLD FRONT THAT PASSED THROUGH CENTRAL IL OVERNIGHT WILL BRING COOLER AND DRIER CONDITIONS TODAY. OUR WEATHER TODAY WILL FEATURE PLEASANTLY WARM TEMPERATURES AND LOWER HUMIDITY LEVELS AS HIGH PRESSURE SETTLES IN FROM THE NORTHWEST THIS AFTERNOON. HIGH PRESSURE BUILDING BACK INTO THE REGION FOR THE SHORT TERM BRINGING A DRIER FORECAST AND A LESS MUGGY AIRMASS. TEMPS JUST BELOW NORMAL FOR THE NEXT TWO DAYS BEHIND TODAYS COLD FRONT. WIDE UPPER RIDGE OVER THE SOUTHERN THIRD OF THE CONUS STARTING TO AMPLIFY A BIT TOWARDS THE END OF THE WEEK.
114 PM EDT TUE JUL 21 2015 SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS ALONG A PASSING COLD FRONT THIS AFTERNOON WILL BE FOLLOWED BY DRY WEATHER AND SEASONAL TEMPERATURES THE REMAINDER OF THE WEEK. THE COLD FRONT ACCOMPANIED BY SHOWERS AND ISOLATED THUNDERSTORMS IS PROGRESSING THROUGH THE FORECAST AREA AND IS TIMED TO PASS THROUGH THE REGION BY THIS EVENING. DRY AIR ENTRAINMENT IN THE WAKE OF THE FRONT IS EXPECTED TO BRING COMFORTABLE CONDITIONS WITH A CLEAR SKY TONIGHT AS HIGH PRESSURE STRENGTHENS. HIGH PRESSURE WILL BE THE DOMINANT THROUGH THE SECOND HALF OF THE WEEK.
QUIET WEATHER IS EXPECTED ACROSS SOUTHERN WISCONSIN THIS EVENING AND WEDNESDAY AS RIDGING ALOFT AND HIGH PRESSURE AT THE SURFACE CONTINUE TO AFFECT THE REGION. THE HIGH OVER THE REGION SHOULD KEEP WINDS LIGHT OVERNIGHT.
146 PM EDT TUE JUL 21 2015 A COLD FRONT WILL ENHANCE A LINE OF SHOWERS AND THUNDERSTORMS ACROSS NORTHERN NEW YORK THIS MORNING AND ACROSS VERMONT THIS AFTERNOON.
THE FORECAST AREA WILL REMAIN ALONG THE SOUTHERN EXTENT OF A BROAD UPPER LEVEL TROUGH RESULTING IN WEST-NORTHWESTERLY FLOW ALOFT. A LEE SIDE TROUGH WILL REMAIN OVER THE AREA AT THE SURFACE THROUGH TONIGHT WHILE A FRONTAL BOUNDARY APPROACHES FROM THE OHIO VALLEY.
426 PM EDT TUE JUL 21 2015 AVIATION SECTION UPDATED HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH THE END OF THE WEEK. COURTESY OF HIGH PRESSURE. MODEL DATA SUGGEST UPPER HEIGHTS WILL BEGIN TO RISE DURING THIS PERIOD AS UPPER TROUGH OVER THE GREAT LAKES WILL LIFT OFF INTO NEW ENGLAND ON WEDNESDAY. AND SOUTHERN PLAINS RIDGE EXPANDS INTO THE MIDWEST.
SW FLOW AHEAD OF BROAD TROUGH TO OUR WEST WILL PULL DEEPER SUB TROPICAL MOISTURE FROM THE REMNANTS OF DELORES FURTHER NORTH INTO THE ROCKIES. SHEAR BEGINS TO INCREASE AS WELL AS JET MAX ASSOCIATED WITH TROUGH SLIDES INTO THE NORTHERN ROCKIES.
UPPER RIDGE REMAINS IN CONTROL. BUT MAYBE A DEGREE HIGHER OUT TO THE WEST WHERE THE BOUNDARY LAYER TEMPERATURES ARE A BIT WARMER.
THE AMOUNT OF CAPE THAT WILL BECOME AVAILABLE WILL DEPEND ON HOW MUCH ADDITIONS SURFACE HEATING CAN BE ACHIEVED AS TEMPS ARE COOLER THAN EXPECTED THIS AFTERNOON DUE TO CLOUD COVER THAT LINGERED INTO MID DAY. THE RIDGE WILL SLOWLY PUSH BACK INTO THE REGION MAKING WAY FOR HEIGHT RISES TOMORROW WHICH WILL GREATLY DECREASE STORM CHANCES ACROSS THE FA TOMORROW AFTERNOON. THE BEST CHANCES WILL BE IN OUR WESTERN ZONES WHICH WILL BE LOCATED NEAR THE WESTERN EDGE OF THE RIDGE.
/ISSUED 735 AM EDT TUE JUL 21 2015/ THE UPPER RIDGE OVER THE TX/LA REGION WILL GRADUALLY SLIDE WESTWARD DURING THE SHORT TERM AS A TROUGH DEEPENS INTO THE GREAT LAKES AREA.
12Z SOUNDING SHOWS SIGNIFICANT CONVECTIVE OVERTURNING WITH VERY SHALLOW LOW LEVEL MOISTURE AND A MARKED DECREASE IN MOISTURE JUST ABOVE THAT THROUGHOUT THE LOW LEVELS. MID LEVEL HEIGHTS RISE AS RIDGE ONCE AGAIN AMPLIFIES.
246 PM CDT TUE JUL 21 2015 UPPER LVL RIDGE HAS BROKEN DOWN SLIGHTLY AS NW FLOW ALOFT HAS BROUGHT AN OUTFLOW BOUNDARY INTO SOUTHERN AR. THIS FLATTENING OF THE RIDGE WILL ONLY BE TEMPORARY. WITH RIDGE ONCE AGAIN EXPANDING NWD. THE GULF REMAINS QUIET EXCEPT FOR AN UPPER LOW NEAR THE YUCATAN. A WEAK COLD FRONT IS ON APPROACH AND WILL BACK DOOR OVER AR AND MAY SHIFT SFC WINDS FM SW TO NE FOR KELD/KMLU LATE WED.
Cooler but drier and locally breezy conditions are expected across the Inland Northwest for today. Dry and breezy conditions are the main concern through the evening as cooler maritime air spills over the Cascades following the passage of last night's cold front. Gusts in the 30-35 mph range should be common as the afternoon upslope winds over the Cascades break allowing cooler, dense air to spill through the Cascade gaps.
1226 PM CDT TUE JUL 21 2015 HIGH PRESSURE ENCOMPASSES THE ENTIRE NORTH CENTRAL U. CLEAR SKIES AND LOW HUMIDITY WILL PREVAIL TODAY WITH HIGH TEMPERATURES SLIGHTLY BELOW NORMAL IN THE LOW 80S. MID LEVEL MOISTURE WILL INCREASE TONIGHT ON THE WESTERN PERIPHERY OF THE HIGH.
253 PM CDT TUE JUL 21 2015 HIGH PRESSURE SLOWLY MOVING EAST THROUGH THE CWA WHICH HAS LEAD TO A BEAUTIFUL DAY. HIGH PRESSURE WILL KEEP WINDS LIGHT THE LONGEST IN NORTHWEST IOWA SO LOWS WILL BE COOLEST THERE. CENTRAL SOUTH DAKOTA WILL SEE A SOUTHERLY GRADIENT INCREASE SO LOWS WILL BE WARMER. TRANSITIONING INTO A WARMER MORE HUMID AND MORE UNSTABLE.
THE MARINE LAYER THAT RETURNED OVERNIGHT HAS KEPT MOSTLY CLOUDY CONDITIONS ALONG MANY COASTAL AREAS WHERE TEMPERATURES HAVE BEEN A GOOD 10 DEGREES COOLER COMPARED TO YESTERDAY. CHANCES FOR CONVECTION DIMINISH TONIGHT AS A MID/UPPER LEVEL TROUGH APPROACHES FROM THE NORTH.
STILL MAY SEE SOME ADDITIONAL DEVELOPMENT WITH DAYTIME HEATING AS HIGH PRESSURE EXITS TO THE EAST AND ELONGATED LOW PRESSURE REMAINS JUST WEST OF THE STATE. UPPER LEVEL RIDGING THEN BUILDS OVER THE PLAINS STATES.
SOMEWHAT FLAT UPPER RIDGE OVER THE SOUTHERN U. HAS NOW KICKED SHOWERS AND STORMS OFF OVER THE HIGHER TERRAIN AND ADJACENT PLAINS. MODELS INDICATE THAT THE UPPER RIDGE WILL START TO STRENGTHEN AND BUILD INTO COLORADO. AND 80S FOR THE HIGH VALLEYS. \/HODANISH PLENTY OF MOISTURE IN PLACE TO CONTINUE WIDESPREAD CONVECTION OVER AND NEAR THE HIGHER TERRAIN THIS EVE.
OTHERWISE CLEAR SKIES TO DEVELOP TONIGHT UNDER LIGHT WINDS AS THE HIGH PRESSURE RIDGE SETTLES OVER THE AREA. QUIET CONDITIONS TO CONTINUE INTO AT LEAST THE START OF WEDNESDAY AS HIGH PRESSURE DRIFTS OVER THE REGION. THIS CONVERGENT REGION WAS BETWEEN TWO HIGHS PRESSURE AREAS AND APPEARS TO BE AN EXTENSION OF A WARM FRONT DEVELOPING OVER THE NORTHERN PLAINS LIFTING NORTHWARD.
BUT STAYING SOUTH OF IA WITH SHORT WAVE RIDGING APPROACHING FROM KS/NE/SD.
350 PM EDT TUE JUL 21 2015 UPPER LAKES IS STILL WITHIN THE INFLUENCE OF TROUGHING ALOFT WITH COOLER AIR ALOFT.
207 PM EDT TUE JUL 21 2015 SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS ALONG A PASSING COLD FRONT THIS AFTERNOON WILL BE FOLLOWED BY DRY WEATHER AND SEASONAL TEMPERATURES THE REMAINDER OF THE WEEK. THE COLD FRONT ACCOMPANIED BY SHOWERS AND ISOLATED THUNDERSTORMS IS PROGRESSING THROUGH THE FORECAST AREA AND IS TIMED TO PASS THROUGH THE REGION BY THIS EVENING. DRY AIR ENTRAINMENT IN THE WAKE OF THE FRONT IS EXPECTED TO BRING COMFORTABLE CONDITIONS WITH A CLEAR SKY TONIGHT AS HIGH PRESSURE STRENGTHENS. HIGH PRESSURE WILL BE THE DOMINANT THROUGH THE SECOND HALF OF THE WEEK.
TEMPERATURES WEDNESDAY WILL BE SEVEREAL DEGREES COOLER ON THE OTHER SIDE OF THIS FRONT. WITH HEAT INDICES IN THE LOWER TO MID 90S. UPPER RIDGING REMAIN OVER SOUTHERN PLAINS WITH UPPER TROUGH ACROSS THE EASTERN SEA-BOARD.
235 PM EDT TUE JUL 21 2015 A COLD FRONT CROSSES TONIGHT. DRY HIGH PRESSURE FOR WEDNESDAY INTO THE WEEKEND. A REAL COLD FRONT DROPS RAPIDLY SOUTHEAST ACROSS THE AREA TONIGHT. THEN FOLLOWED BY A MUCH COOLER AND DRIER AIRMASS. MODELS INDICATE DRIER LOW LEVEL AIR FLOWING IN AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. AND EXPECT A SUN FILLED WEDNESDAY WITH MUCH COOLER AND DRIER AIR DESPITE THE SUNSHINE. LOOK FOR HIGHS IN THE LOWER 80S WEDNESDAY. HIGH PRESSURE WILL PROVIDE A TRANQUIL END TO THE WORK WEEK.