Aikyam-Lab/Synoptic-Bench huggingface dataset:
WATER VAPOR IMAGERY SHOWS TROUGH AXIS STILL THROUGH SE TX BUT A CLOSED UPPER LOW HAS DEVELOPED MORE OVER THE RIO GRANDE VALLEY THAN OVER SE TX. THINK THE LOW HAS DROPPED A LITTLE FARTHER SOUTH AND WEST THAN WAS FORECAST WHICH HAS LIMITED LARGE SCALE ASCENT OVER THE REGION. THE GFS/NAM RUNS HAVE THIS HIGHER MOISTURE SLOWLY SLIDING INTO SE TX BUT LOOK FOR THE BULK OF THE HIGHER MOISTURE TO MOVE INTO E TX AND W LA TODAY. GFS/NAM/ECMWF ARE ALL IN PRETTY GOOD AGREEMENT WITH A STRONG UPPER LOW DEVELOPING OVER THE PLAINS TODAY INTO WED. THIS IS ALSO WHEN THE UPPER LOW OVER S TX BEGINS TO PUSH MORE TO THE NE AND SHEAR OUT WITH A COUPLE PIECES OF VORTICITY ADVECTING OVER SE TX.
HIGH PRESSURE RIDGE WILL SINK FROM NORTHEAST OF THE REGION TO EAST OF THE REGION TODAY. THIS WILL ALSO ALLOW A WEAK TROUGH TO APPROACH SOUTHEAST GA.
TEMPERATURES WILL BE COOLER TODAY BEHIND A COLD FRONT.
THE MAIN QUESTION TONIGHT IS HOW FAR NORTH TO GO WITH THE HIGHER POPS. CURRENT SURFACE ANALYSIS PLACES COOL HIGH PRESSURE OVER THE NORTHERN PLAINS. UPPER LEVEL ANALYSIS PLACES BROAD TROUGH OVER THE NORTH-CENTRAL CONUS WITH POTENT SHORT WAVE DIGGING OVER THE NORTHERN ROCKIES INTO THE PLAINS. THIS WILL CONTINUE TO KEEP THE HIGHEST CHANCES ALONG THE SOUTHERN TIER OF THE STATE. WHILE AREAS TO THE NORTH MAY PUSH INTO THE LOWER 70S. AS A BROAD UPPER LEVEL TROUGH CONTINUES DIGGING EASTWARD ACROSS THE NORTHERN PLAINS.
HIGHS DECREASING A FEW DEGREES TODAY TO THE LOW TO MID 80S. MOST OF THE SYNOPTIC MODELS ARE IN GENERAL AGREEMENT WITH THE DIGGING OF THE UPPER TROUGH OVER THE DAKOTAS. FORMING A CLOSED LOW IN SOUTH DAKOTA BY THIS EVENING BEFORE IT HOOKS NORTHEAST ACROSS MINNESOTA ON WEDNESDAY. THE ECMWF AND CANADIAN MODELS ARE A BIT STRONGER WITH THE ATTENDANT SURFACE CYCLONE. GENERAL CONSENSUS REMAINS WITH TRACKING THE SURFACE COLD FRONT THROUGH THE FORECAST AREA EARLY WEDNESDAY MORNING PRECEDED BY THE INITIAL WAVE OF SHOWERS AND THUNDERSTORMS. THE HIGHER RESOLUTION MODELS SHOW SOME BREAKS BETWEEN INDIVIDUAL LINES OF STORMS.
123 AM EDT TUE AUG 18 2015 HIGH PRESSURE WILL CONTINUE TO MOVE OFF TO THE EAST AS A DIFFUSE WARM FRONT LIFTS NORTH OF THE AREA TUESDAY.
SFC CYCLOGENESIS WILL TAKE PLACE OVER THE CENTRAL PLAINS WITH THE CENTER OF THE LOW MOVING CLOSE TO THE NEBRASKA/KANSAS BORDER THROUGH THE DAY TUESDAY. STRONG ISENTROPIC UPGLIDE IN WAA REGIME AHEAD OF THE LOW SHOULD PROVIDE CONTINUED SHOWERS AND TSTMS THROUGHOUT THE MORNING /EARLY AFTERNOON HOURS ACROSS THE FORECAST AREA. AS THE LOW DRIFTS EAST OVER THE CWA TUESDAY AFTERNOON. A STRONG COLD FRONT BEHIND THE LOW WILL PROVIDE CONTINUED CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE DAY TIME HOURS. MOST OF THIS PCPN AROUND THE BACKSIDE OF THE LOW SHOULD MOVE OUT BY TUESDAY NIGHT LEAVING BRISK NORTHWEST WINDS THROUGH THE OVERNIGHT. WEDNESDAY LOOKS DRY BUT COOLER AS UPPER TROUGH AXIS DIGS ACROSS THE SOUTHERN PLAINS REGION.
THE FIRST IN A SERIES OF UPPER LEVEL TROUGHS WILL ROTATE ACROSS THE CENTRAL/NORTHERN PLAINS TODAY AND OUR NORTHERN ZONES WILL LIKELY GET BRUSHED BY THE LEAD TROUGH WHICH SHOULD RESULT IN SCATTERED CONVECTION ACROSS OUR NORTHERN MOST ZONES.
658 AM EDT TUE AUG 18 2015 A SLOW MOVING COLD FRONT WILL STALL ACROSS NORTHERN MAINE LATER TODAY THROUGH TONIGHT. A WEAK COLD FRONT WILL SLOWLY MOVE SOUTH AND STALL ACROSS NORTHERN MAINE THIS AFTERNOON. HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER TO MID 80S ACROSS NORTHERN AREAS AND ALONG THE DOWNEAST COAST. LOW TEMPERATURES TONIGHT WILL GENERALLY RANGE FROM THE LOWER TO MID 60S ACROSS THE FORECAST AREA. HIGH PRESSURE WILL REMAIN TO THE EAST OF NEW ENGLAND WHILE INTENSE LOW PRESSURE MOVES NORTHWARD THROUGH THE WESTERN GREAT LAKES.
A COLD FRONT WILL MOVE THROUGH THE PLAINS TUESDAY SCATTERED THUNDERSTORMS WILL DEVELOP AHEAD OF THIS FRONT. AR HAS BEEN IN BETWEEN UPPER HIGH PRESSURE RIDGING TO THE SE AND A W TO NW UPPER FLOW OVER THE UPPER PLAINS.
THE FLORIDA PENINSULA REMAINS UNDERNEATH A DEEP EAST- WEST ORIENTED RIDGE WITH ITS AXIS ACROSS NORTH/CENTRAL FLORIDA. LITTLE CHANGE IN THE POSITION OF THE RIDGE.
UPPER RIDGING CENTERED OVER SOUTHERN CALIFORNIA AT 00Z WEDNESDAY IS PROJECTED TO TRANSITION TO SOUTHERN NEW MEXICO BY THE WEEKEND WHILE FORECAST DISTRICT REMAINS IN NORTHWESTERLY TO ZONAL UPPER FLOW INTO THE WEEKEND.
Hot weather continues across most of the interior of NorCal today as strong ridging extending from the Gulf of Alaska to the Desert Southwest remains overhead. The exception will be the Delta and southern Sacramento Valley where the return of the Delta Breeze will bring cooler temperatures today.
441 AM EDT TUE AUG 18 2015 ANALYSIS THIS MORNING REVEALS A LOWER-TROPOSPHERIC RIDGE EXTENDING ACROSS THE SUBTROPICAL NORTH ATLANTIC TO NORTHERN FLORIDA. AND UNSTABLE EASTERLY FLOW REGIME SOUTH OF THE RIDGE AXIS. A HIGH PRESSURE RIDGE WILL EXTEND ACROSS THE SOUTHEASTERN UNITED STATES TODAY THROUGH WEDNESDAY. THE RIDGE WILL SHIFT SOUTHWARD ACROSS THE FLORIDA PENINSULA.
TODAY THROUGH WEDNESDAY NIGHT UPPER LEVEL ANALYSIS HAS STRONG TROF MOVING ACROSS THE NORTHERN PLAINS. LOW PRESSURE IS LOCATED ACROSS THE NEBRASKA PANHANDLE. WITH WEAK INVERTED TROF INTO CENTRAL SOUTH DAKOTA. RAIN SHOWERS WILL DIMINISH ACROSS THE AREA TONIGHT AS COOL HIGH PRESSURE MOVES INTO THE NORTHERN PLAINS. WITH SOME 30S POSSIBLE ACROSS THE HIGHER BLACK HILLS. UPPER LEVEL TROF/LOW MOVES THROUGH MINNESOTA AS WEAK RIDGING DEVELOPS ACROSS THE NORTHERN ROCKIES. HIGH PRESSURE REMAINS OVER THE AREA WEDNESDAY NIGHT. INTO THE LOWER TO MID 50S MOST LOCATIONS.
307 AM MDT TUE AUG 18 2015 AN UPPER LEVEL TROUGH OVER WYOMING WILL MOVE INTO THE CENTRAL PLAINS TODAY. A COLD FRONT ASSOCIATED WITH THIS SYSTEM IS PUSHING SOUTHEAST ACROSS COLORADO AT THIS TIME. ENOUGH MOISTURE SHOULD LINGER IN THE LOW LEVELS FOR AREAS OF LOW CLOUDS. IT WILL BE COOL TODAY WITH HIGHS IN THE LOWER 70S FOR MOST OF NORTHEAST COLORADO. WEDNESDAY WILL SEE THE EXITING TROUGH TO THE EAST WITH INCREASED SUBSIDENCE BEHIND IT HELPING TO DRY THINGS OUT OVER THE REGION. TEMPERATURES LIKE TUESDAY WILL BE WELL BELOW NORMAL WITH HIGHS STAYING IN THE LOWER 70S.
Could see showers and storms form out of the ahead of the cold front across Haskell and Throckmorton Counties by Wednesday morning as the front moves across the Red River.
500 AM EDT TUE AUG 18 2015 A SLOW MOVING COLD FRONT WILL STALL ACROSS NORTHERN MAINE LATER TODAY THROUGH TONIGHT. A WEAK COLD FRONT WILL SLOWLY MOVE SOUTH AND STALL ACROSS NORTHERN MAINE THIS AFTERNOON. HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER TO MID 80S ACROSS NORTHERN AREAS AND ALONG THE DOWNEAST COAST. LOW TEMPERATURES TONIGHT WILL GENERALLY RANGE FROM THE LOWER TO MID 60S ACROSS THE FORECAST AREA. HIGH PRESSURE WILL REMAIN TO THE EAST OF NEW ENGLAND WHILE INTENSE LOW PRESSURE MOVES NORTHWARD THROUGH THE WESTERN GREAT LAKES.
341 AM PDT TUE AUG 18 2015 HIGH PRESSURE ALOFT WILL WEAKEN AND MOVE SOUTH OF SOUTHERN CALIFORNIA AS A TROUGH OF LOW PRESSURE MOVES INLAND THROUGH THE PACIFIC NORTHWEST.
LOW PRESSURE WILL CONTINUE TO DEEPEN ACROSS THE CENTRAL PLAINS TODAY.
THE SUBTROPICAL RIDGE WILL MOVE WEST OF ARIZONA ALLOWING A DRY NORTHWEST FLOW TO SET UP OVER THE STATE.
THE DRY COLD FRONT WORKED THROUGH THE I-70 CORRIDOR AROUND 8-10PM. WITH UPSTREAM TROUGH OVER THE NRN ROCKIES APPROACHING THE CENTRAL ROCKIES. STORMS WILL NOT BE FAVORED IN THIS REGION AS THE MOIST ENVIRONMENT GETS PUSHED EASTWARD BY UPSTREAM TROUGH. COOLER AND MUCH DRIER AIR UNDER NW FLOW OVER THE AREA TUESDAY AND TUESDAY NIGHT SHOULD RESULT IN MAX TEMPERATURES 5-10 DEGREES F LOWER THAN TODAY.
SLOWLY INCREASING FROM WEST TO EAST WITH APPROACH OF LEAD SHORT WAVE AND FORCING WITH 850 MB WINDS BACKING TO THE SOUTH BY 18Z AHEAD OF DEEPENING TROUGH TO THE WEST. WITH UPPER 70S TO LOWER 80S INLAND WITH THE WARMER TEMPERATURES CLOSE TO THE WI/IL BORDER. FORECAST CONFIDENCE MEDIUM MODELS VARY WITH TIMING AND LOCATION OF 500 MB TROUGH AS IT CLOSES OFF OVER THE EASTERN DAKOTAS THIS AFTERNOON/EVENING AND REACHES SRN OR CENTRAL MN BY WED MORNING. DIFFLUENT UPPER FLOW OVERSPREADS AREA THIS EVENING AHEAD OF 100-110KT UPPER JET MAX ROUNDING BASE OF TROUGH THAT PUNCHES INTO WRN WI BY 12Z WED.
MOISTURE WILL CONTINUE TO STREAM NORTH TONIGHT AND INTERACT WITH AN UPPER TROF. HIGHS WILL GENERALLY BE IN THE LOWER AND MIDDLE 80S. IT WILL BE A WARM AND MUGGY NIGHT WITH LOWS IN THE LOWER 70S.
A SECONDARY VORT MAX THEN MOVES THROUGH THE BASE OF THE TROUGH ON WED/WED NIGHT AND DRIVES A COLD FRONT THROUGH MO/IL. DEPENDING ON THE SPEED OF THE COLD FRONT ON WED AND ON THE AMOUNT OF CLOUDINESS AHEAD OF THE FRONT, THERE MAY BE ENOUGH INSTABILITY ACROSS THE SOUTHEASTERN CWA TO TAP INTO 40-50 KTS OF 0-6KM SHEAR FOR A FEW STRONG TO SEVERE THUNDERSTORMS ON WED AFTN.
WATER VAPOR SHOWS THE MID/UPPER LEVEL LOW SOUTH OF COAHUILA WITH A SHEAR AXIS EXTENDING TO THE NORTHEAST INTO THE BRUSH COUNTRY. LOW LEVEL FLOW HAS STRENGTHENED TO 20-25 KNOTS AS LOW PRESSURE DEEPENS OVER THE SOUTHERN HIGH PLAINS. BUT MODELS KEEP THE HIGHER MOISTURE OFFSHORE TODAY WITH LIMITED CONVECTION EXPECTED INLAND.
In its wake, drier northwest winds will move in by late morning/midday, with the cold front pushing farther southeast into south-central KS late in the afternoon. We cooled off highs a bit more with the front moving in a bit faster than originally thought, with highs generally in the lower 80s for most locations (with the exception being far south central KS where highs will top out around 89-92F). For Wednesday, a strong upper level trough will be moving east across the Upper Midwest and Missouri Valley region.
327 AM EDT TUE AUG 18 2015 WARM AND HUMID AIR WILL REMAIN OVER NEW ENGLAND FOR THE NEXT SEVERAL DAYS AS A RIDGE OF HIGH PRESSURE BUILDS OVER THE REGION.
A STRONG AREA OF HIGH PRESSURE OVER SOUTHERN CALIFORNIA WILL GRADUALLY GIVE WAY TO A BROAD AREA OF LOW PRESSURE DROPPING DOWN FROM THE NORTHWEST AFTER WEDNESDAY. HIGHS MAY BE A DEGREE OR TWO LOWER WEDNESDAY AS HEIGHTS LOWER SLIGHTLY IN RESPONSE TO THE TROUGH DROPPING DOWN FROM THE NORTHWEST.
AND WEDNESDAY THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COLD FRONT STRETCHING ACROSS SOUTHWEST TO EAST-CENTRAL WISCONSIN EARLY THIS MORNING. AS LOW PRESSURE CONSOLIDATES OVER THE CENTRAL PLAINS. THE PRIMARY COLD FRONT IS PROJECTED TO STALL OVER CENTRAL AND EAST- CENTRAL WISCONSIN. A STRONG AREA OF LOW PRESSURE WILL LIFT NORTHEAST TOWARDS MINNEAPOLIS WHILE PUSHING A COLD FRONT INTO SOUTHWEST OR CENTRAL WISCONSIN BY 12Z WED. THE MOST POTENT SWATH OF STORMS SHOULD ARRIVE LATE IN THE NIGHT AHEAD OF THE COLD FRONT AND CLOSED MID-LEVEL CIRCULATION. LOW PRESSURE WILL SLOWLY MOVE NORTHEAST OVER FAR NORTHWEST WISCONSIN AS THE COLD FRONT SWEEPS ACROSS NORTH-CENTRAL AND NORTHEAST WISCONSIN.
355 AM EDT TUE AUG 18 2015 THE SOUTH FLOW ASSOCIATED WITH OFFSHORE HIGH PRESSURE WILL BRING HIGH MOISTURE TO THE FORECAST AREAS THROUGH MUCH OF THE WEEK. DEEP SOUTHERLY FLOW AROUND AN AREA OF HIGH PRESSURE CENTERED OFFSHORE WILL HOLD A VERY MOIST AIRMASS ACROSS THE REGION. WENT WITH PERSISTENCE FOR OVERNIGHT LOWS IN THE LOWER 70S. OUR AREA WILL BE BETWEEN SYSTEMS WITH HIGH PRESSURE OFFSHORE AND A COLD FRONT OVER THE MISSISSIPPI RIVER VALLEY. MOSTLY CLOUDY SKIES WILL HELP KEEP MAX TEMPS IN THE LOWER 90S AND OVERNIGHT LOWS IN THE 70 TO 75 DEGREE RANGE.
WITH HIGH PRESSURE CENTERED OVER NORTHERN ND AND SOUTHERN SK. UPPER LEVEL ANALYSIS SHOWS TROF OVER THE UPPER MIDWEST. THERE ARE SOME DIFFERENCES ON TIMING AND EVOLUTION OF UPPER LOW AS IT CROSSES. HIGHS ON TUESDAY WILL ONLY BE IN THE LOW TO MID 60S ACROSS THE PLAINS. AS THE DEVELOPING UPPER LOW WRAPS UP TO THE EAST.
CHANCES OF RAIN WILL BE LOW TUESDAY AS THE AREA REMAINS ON THE BACK SIDE OF THE DEPARTING UPPER LEVEL LOW. BY WEDNESDAY A STRONG UPPER LEVEL LOW WILL BE APPROACHING THE AREA BRINGING BETTER CHANCES OF RAIN WITH IT.
THE CLOUD COVERAGE WILL CONTINUE TO INCREASE THIS MORNING AS THE STRONG LOW PRESSURE AREA APPROACHES MN. THE NAM/ECMWF ARE SIMILAR WITH THE MOVEMENT OF THE LOW WHILE THE GFS IS DIFFERENT. THE LOW PRESSURE CENTER WILL CONTINUE TO DEEPEN AND WILL BE NEAR THE TWIN CITIES BY 06Z. THE HEAVY RAIN WILL TAPER OFF BY MORNING BUT IT WILL CONTINUE TO RAIN MOST OF THE DAY WEDNESDAY AS THE LOW PRESSURE CENTER MOVES THROUGH NW WI.
206 AM PDT TUE AUG 18 2015 DRY WEATHER WILL CONTINUE THIS WEEK AS HIGH PRESSURE REMAINS IN CONTROL.
HIGH PRESSURE ALOFT AND WEAK LOW LEVEL OFFSHORE FLOW WILL BRING WARM WEATHER TODAY AND WEDNESDAY.
646 AM EDT TUE AUG 18 2015 HIGH PRESSURE REMAINS OFFSHORE OVER THE NEXT FEW DAYS AS A LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT APPROACH FROM THE WEST.
TEMPERATURES WILL BE WELL ABOVE NORMAL THROUGH THE MIDDLE OF THE WEEK AS A STRONG RIDGE OF HIGH PRESSURE BUILDS OVER THE STATE.
HIGHS WILL GENERALLY BE 3 TO 7 DEGREES COOLER THAN YESTERDAY.
146 AM EDT TUE AUG 18 2015 ATLANTIC HIGH PRESSURE WILL PREVAIL INTO LATE WEEK WHILE AN INLAND TROUGH OF LOW PRESSURE AND WEAK COLD FRONT EVENTUALLY APPROACH FROM THE NORTHWEST.
A PERSISTENT RIDGE OFF THE PAC COAST OF WASHINGTON IN CONJUNCTION WITH A TROUGH CENTERED OVER THE CENTER OF THE CONUS WILL KEEP THE PAC NW IN NW FLOW ALOFT. A SHORT WAVE TROUGH IS MOVING SE ACROSS MONTANA TODAY. WEAK RIDGING ALOFT WILL RESULT IN WARMER CONDITIONS WED WITH STILL WEAKER WINDS.
HIGHS TODAY WILL RANGE FROM THE UPPER 70S ALONG THE VIRGINIA/KENTUCKY BORDER TO THE LOWER 80S ELSEWHERE ACROSS THE AREA.
125 AM EDT TUE AUG 18 2015 HAZY, WARM AND HUMID LATE SUMMER WEATHER WILL CONTINUE ACROSS THE REGION THROUGH WEDNESDAY AS STRONG HIGH PRESSURE REMAINS IN CONTROL OF REGIONAL CONDITIONS.
125 AM EDT TUE AUG 18 2015 SHOWERS AND THUNDERSTORMS WILL CONTINUE OVERNIGHT AS A WEAKENING UPPER LEVEL DISTURBANCE MOVES THROUGH THE OHIO VALLEY AND INTO THE LOWER GREAT LAKES REGION.
THE UPPER LOW CONTINUES TO DRIFT SOUTHWEST INTO NORTHERN MEXICO WITH A VERY WEAK SHEAR AXIS CUTTING ACROSS THE MIDDLE OF SOUTH TEXAS.
146 AM EDT TUE AUG 18 2015 THE SOUTH FLOW ASSOCIATED WITH OFFSHORE HIGH PRESSURE WILL BRING HIGH MOISTURE TO THE FORECAST AREAS THROUGH MUCH OF THE WEEK. THE MOISTURE IS ASSOCIATED WITH THE SOUTH FLOW CIRCULATING AROUND OFFSHORE HIGH PRESSURE. 25 OF AN INCH THROUGH TONIGHT WITH THE HIGHER AMOUNTS MAINLY TOWARDS THE UPSTATE. OVERNIGHT LOWS GENERALLY IN THE LOWER 70S. UPPER LEVEL RIDGE WILL RETROGRADE WESTWARD AND PW VALUES WILL REMAIN HIGH THROUGH THE PERIOD. MODELS KEEP UPPER LEVEL RIDGE TO THE WEST OF THE AREA WITH WEAK NORTHWEST FLOW OVER SC. A COUPLE OF WEAK SHORT WAVES WILL MOVE THROUGH WITH A COLD FRONT APPROACHING TOWARD THE END OF THE PERIOD. MOISTURE WILL BE ON THE INCREASE DURING THE TAF PERIOD ASSOCIATED WITH THE SOUTH FLOW ON THE BACKSIDE OF OFFSHORE HIGH PRESSURE.
THIS MORNING CLUSTER OF SHOWERS AND THUNDERSTORMS ACROSS THE NORTH WILL CONTINUE EAST WITH THE HIGHER POPS FOCUSED NORTH OF HIGHWAY 2.
202 AM EDT TUE AUG 18 2015 HIGH PRESSURE WILL REMAIN OVER THE WESTERN ATLANTIC THROUGH WEDNESDAY. WHILE A SERIES OF LOW PRESSURE TROUGHS DEVELOP OVER THE REGION. A COLD FRONT WILL MOVE VERY SLOWLY EAST.
304 AM CDT TUE AUG 18 2015 Main focus in the near term is the potential for showers and thunderstorms, especially late tonight through Wednesday night, as a seasonally strong mid level trough approaches from the Plains. Starting with today, the weak upper low responsible for the mainly diurnal shower and thunderstorm activity the last few days has shifted east of the region. The chance for showers and thunderstorms will diminish from west to east Wednesday night as a cold front passes through the area.
AN UPPER LEVEL TROUGHING PATTERN WAS IN PLACE OVER THE GREATER CONUS/NORTH AMERICAN DOMAIN. THE UPPER RIDGE THAT PROVIDED VERY WARM AND DRY WEATHER OVER THE SOUTHERN STATES LAST WEEK HAS SHIFTED FURTHER TO THE WEST. THE NORTHERN STREAM WAS BRINGING A TROUGH SOUTHWARD FROM THE NORTHERN GREAT BASIN TO THE SE PLAINS. WEAK/BROAD HIGH PRESSURE ALONG THE ATLANTIC COAST PROVIDED A SOUTHERLY FLOW.
A DECENT LATE-SUMMER COLD FRONT WILL BRING A TASTE OF FALL FOR WEDNESDAY. A REINFORCING SURGE OF COOLER AIR WILL MAKE IT THROUGH THE PANHANDLES OVERNIGHT TONIGHT.
THE UPPER LEVEL TROUGH SHOULD REACH WESTERN SD LATER THIS EVENING AND THE MISSOURI RIVER VALLEY BY 9Z. WITH S/W RIDGING DEVELOPING ACROSS THE NORTHERN PLAINS EARLY IN THE PERIOD. HOWEVER ANOTHER FAIRLY STRONG TROF WILL MOVE ACROSS THE NORTHERN PLAINS EARLY IN THE WEEKEND.
346 AM CDT TUE AUG 18 2015 LATEST WATER VAPOR IMAGERY CONTINUES TO SHOW A WEAKNESS IN THE MID AND UPPER LEVELS IN THE FORM OF A TROUGH/SHEAR AXIS.
A COLD FRONT CURRENTLY EXTENDS FROM NORTHERN LOWER MICHIGAN THROUGH SOUTHERN IOWA AND INTO CENTRAL COLORADO. THE COLD FRONT WILL START TO MOVE SOUTHEAST AND REACH INTO NORTHWEST ARKANSAS LATE TONIGHT. AS THE COLD FRONT GETS CLOSER SHOWERS AND THUNDERSTORMS WILL INCREASE IN COVERAGE WITH THE BEST CHANCE OF THUNDERSTORMS OVER PORTIONS OF NORTHEAST ARKANSAS. ON WEDNESDAY AS THE COLD FRONT MOVES SLOWLY THROUGH ARKANSAS MORE SHOWERS AND THUNDERSTORMS WILL DEVELOP AND MOVE ACROSS THE FORECAST AREA. TEMPERATURES WILL BE A LITTLE COOLER ON WEDNESDAY WITH MORE CLOUDS OVER THE REGION WITH HIGHS IN THE LOW TO MID 80S. BY WEDNESDAY NIGHT THE COLD FRONT MOVES THROUGH THE FORECAST AREA WITH MORE SHOWERS AND THUNDERSTORMS EXPECTED.
AND AS BROAD UPPER LEVEL TROUGHING APPROACHES AND MOVES THRU THE REGION WED NIGHT INTO THU. AS INFLUENCES FROM BROAD UPPER LEVEL TROUGH BISECTING THE CNTRL U. HIGHS WILL BE A FEW DEGREES BELOW SEASONAL NORMAL VALUES GENERALLY RANGING IN THE LOW TO MID 80S.
318 AM CDT TUE AUG 18 2015 A BROAD UPPER TROUGH IS PRESENT ACROSS THE COUNTRY WITH A PIECE OF ENERGY DIVING INTO THE BASE OF THE TROUGH OVER THE CENTRAL PLAINS. THIS MCS IS AHEAD OF A PIECE OF ENERGY THAT IS DIVING INTO THE BASE OF THE TROUGH THAT IS DISLODGING THE SURFACE FRONT. IN ADDITION A SECONDARY WAVE WILL ROTATE DOWNWARD INTO THE BASE OF THE TROUGH AND BRING A POTENTIAL FOR SCATTERED SHOWERS BY MORNING FROM THE WEST.
A DEEPENING UPPER-LEVEL LOW PRESSURE SYSTEM CURRENTLY MOVING OUT INTO THE NORTHERN AND CENTRAL PLAINS WILL BEGIN TO HAVE AN EFFECT ON THE FORECAST AREA LATER THIS MORNING. AN UNSEASONABLY STRONG COLD FRONT WILL MOVE ACROSS THE AREA OVERNIGHT TONIGHT.
In its wake, drier northwest winds will move in by late morning/midday, with the cold front pushing farther southeast into south-central KS late in the afternoon. We cooled off highs a bit more with the front moving in a bit faster than originally thought, with highs generally in the lower 80s for most locations (with the exception being far south central KS where highs will top out around 89-92F).
THE LOW WILL NOT MOVE MUCH AND BRING WEAK DISTURBANCES THOUGH THE AREA. WILL CONTINUE THE MUGGY NIGHTS WITH LOWS IN THE LOWER TO MIS 70S. HIGHS FRIDAY LOOK TO BE FROM THE MID 80S EAST TO THE LOWER 90S WEST.
THEN MOVING NORTHWARD OVERNIGHT AS THE LOW LEVEL SOUTHEAST FLOW INCREASES UPSLOPE AND MOISTURE. AS THE LARGE SCALE UPPER LEVEL LOW MOVES OVER SOUTHERN NEVADA.
THE LOCAL AREA IS UNDER HIGH PRESSURE TONIGHT WITH A STRONG LOW OFF THE COAST OF SOUTH CAROLINA.
THE FLOW PATTERN OUT OF THE SW BEGINS TO TURN A BIT MORE ACTIVE ON FRI ACROSS THE LOWER MS VALLEY AS THE UPPER RIDGE PATTERN OVER THE NRN GULF BEGINS TO DRIFT EWD. RAIN CHANCES STILL LOOK TO REMAIN PRETTY MUCH NIL OVER THE LOCAL AREA WHERE THE INFLUENCE OF THE UPPER RIDGE WILL HAVE A BIT MORE OF AN EFFECT. AS A STRONGER COLD FRONT OUT OF THE SRN PLAINS PUSHES EWD INTO THE LOWER MS/TN VALLEY REGIONS. SLIGHTLY COOLER AIR MAY THEN BRIEFLY MOVE INTO THE REGION ON WED.
UPPER LOW CONTINUES TO DIVE SOUTH THROUGH CALIFORNIA. AMPLE MOISTURE AND INSTABILITY WRAPPING AROUND THE CORE OF THE LOW EXTENDS EASTWARD INTO NORTHERN NEVADA.
827 PM EDT THU MAY 7 2015 HIGH PRESSURE JUST OFFSHORE TO OUR EAST WILL HEAD FARTHER OUT INTO THE WESTERN ATLANTIC THROUGH THE WEEKEND. LOW PRESSURE WILL REMAIN NEARLY STATIONARY NEAR THE CAROLINAS THIS WEEKEND.
/ISSUED 259 PM CDT THU MAY 7 2015/ RIDGING ALOFT AND A SOUTHERLY BOUNDARY LAYER FLOW HAS MADE FOR ANOTHER WARM DAY OUT THERE. THIS IS LIKELY CONTINUE FRIDAY AS WE REMAIN UNDER THE INFLUENCE OF THE RIDGE ALOFT. WE COULD SEE A COUPLE DEGREES WARMER ON FRIDAY. AND WITH THE RIDGE ALOFT SUPPRESSING GROWTH.
1256 AM EDT FRI MAY 8 2015 MID/UPPER RIDGE HOLDS IN PLACE WITH WEAK STEERING FLOW.
TEMPS DROPPED WITH THE PASSAGE OF A GUST FRONT AHEAD OF THE LINE OF RAIN, BUT THE SYNOPTIC COLD FRONT REMAINS WEST OF ILLINOIS. COLD FRONT JUST NW OF IA INTO CENTRAL KS TO PUSH INTO SE IA AND NW MO BY SUNRISE FRI.
Closed upper level low pressure will continue to dive south across southern California before starting to eject east by later Friday. At the surface, low pressure will remain nearly stationary across the Texas Panhandle. A dry line will trail south from the low with a semi-stationary frontal boundary extending east-northeast from the low into northeastern Kansas and northwestern Missouri. A few of the stronger storms could produce sub-severe hail/winds, but instability/deep layer shear will be a bit on the low side to support a severe threat.
1048 PM EDT THU MAY 7 2015 A COLD FRONT WILL MOVE SOUTHWEST ACROSS THE REGION OVERNIGHT WHILE AN UPPER DISTURBANCE CROSSES NORTHERN AREAS.
MAINLY OVER THE HIGHER TERRAIN. RELATIVELY MILD CONDITIONS EXPECTED OVERNIGHT AS CLOUD COVER MOVING IN OUT OF THE SOUTHEAST SHOULD HELP KEEP TEMPERATURES IN THE LOW 60S TO UPPER 50S ACROSS THE REGION. UPPER RIDGE WILL REMAIN IN PLACE THROUGH THE REST OF THE NEAR TERM. WITH DIURNAL SHOWERS AND STORMS AGAIN POSSIBLE IN THE RIDGES. LARGE SCALE PATTERN LOOKS TO STAY RATHER STAGNANT THROUGH THE PERIOD AS RIDGE REMAINS OVERHEAD.
THE UPPER LEVEL RIDGE THAT HAS PREVAILED ACROSS THE ENTIRE MID SOUTH OVER THE PAST WEEK OR SO WAS BEGINNING TO BREAK DOWN SOME ACROSS WESTERN PORTIONS OF THE FORECAST AREA. SURFACE ANALYSIS THIS AFTERNOON PLACES A COLD FRONT OVER THE NORTHERN/CENTRAL PLAINS AND A DRYLINE EXTENDING SOUTH ACROSS THE TEXAS PANHANDLE AND WEST TEXAS.
AN AREA OF LOW PRESSURE OVER NORTHERN MINNESOTA WILL EXIT THE REGION TONIGHT. AN AREA OF HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE NORTHWEST LATE TONIGHT. THIS HIGH PRESSURE WILL BRING DRY.
THE UPPER LOW DEEPENING OVER CA CONTINUES TO SEND SHORT WAVE ENERGY EAST TO THE PLAINS.
18Z SFC ANALYSIS SHOWS WEAK HIGH PRESSURE IN PLACE OVER EASTERN KENTUCKY AND TENNESSEE WHILE A LARGE AREA OF LOW PRESSURE IS FOUND TO THE WEST. LOW PRESSURE OFF THE SOUTHEAST COAST HAS SENT SOME HIGH CLOUDS UP THIS WAY WHICH SEEMS TO HAVE DELAYED THE CONVECTIVE INITIALIZATION FOR AN HOUR OR TWO IN THE HIGHER TERRAIN EAST OF HERE. TEMPERATURES ARE QUITE WARM THROUGH THE AREA WITH READINGS IN THE LOW TO MID 80S WHILE DEWPOINTS ARE GENERALLY IN THE LOW TO MID 50S. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM THOUGH THERE IS AN EMBEDDED UPPER LOW OFF THE SOUTHEAST COAST.
AS H5 LOW (CURRENTLY OVER CNTL CA) EJECTS INTO THE PLAINS LATER THIS WEEKEND AND RIDGE SHIFTS FURTHER EAST.
HIGH PRESSURE WILL BUILD OVER THE PACIFIC NORTHWEST BRINGING PERIODS OF LOW CLOUDS AND BREEZY CONDITIONS ALONG THE COAST.
753 PM EDT THU MAY 7 2015 LOW PRESSURE OFF THE SOUTH CAROLINA COAST WILL SLOWLY DRIFT NORTHWARD THEN STALL TONIGHT OFFSHORE OF THE MYRTLE BEACH AREA.
MID LEVEL S/W TROUGH IS PROG TO ADVECT ACROSS OUR NW ZONES BY LATE IN THE NIGHT AND POSSIBLY AID IN CONVECTIVE INITIATION IF INCREASE IN ASCENT IS LARGE ENOUGH TO OVERCOME STRONG CINH VALUES.
THE LOW CIGS MAY BE SCOURED LATE TONIGHT/AFTER DAYBREAK FRIDAY. THE LOW CIGS THAT DEVELOP LATE WILL ONLY SLOWLY LIFT BY LATE MORNING/MIDDAY FRIDAY BEFORE BECOMING VFR. SHWRS AND ISOLD TSTMS ARE A BIT MORE CONCENTRATED TODAY THAN IN PREVIOUS DAYS DUE TO THE RETREATING UPPER RIDGE TO OUR EAST AND STRONGER DIVERGENCE ALOFT.
WITH WEAK RIDGING BUILDING INTO THE CWA. STRONG UPPER LOW IS CROSSING CALIFORNIA AND MAKING ITS WAY INTO THE GREAT BASIN. QUIET WEATHER IS EXPECTED TONIGHT AS HIGH PRESSURE REMAINS IN CONTROL. KEEPING COOLER TEMPERATURES ACROSS THE CWA. EXCEPT ACROSS THE HIGHER BLACK HILLS WHERE RAIN WILL CHANGE TO SNOW LATE FRI NIGHT.
801 PM EDT THU MAY 7 2015 HIGH PRESSURE WILL BUILD OVER THE NORTHERN MID-ATLANTIC THROUGH TONIGHT. LOW PRESSURE OFF THE CAROLINA COAST WILL APPROACH THE COASTLINE FRIDAY BEFORE GRADUALLY ERODING THIS WEEKEND.
957 PM EDT THU MAY 7 2015 HIGH PRESSURE JUST OFFSHORE TO OUR EAST WILL HEAD FARTHER OUT INTO THE WESTERN ATLANTIC THROUGH THE WEEKEND. LOW PRESSURE WILL REMAIN NEARLY STATIONARY NEAR THE CAROLINAS THIS WEEKEND.