Aikyam-Lab/Synoptic-Bench huggingface dataset:
145 AM EDT SUN AUG 16 2015 A WEAK UPPER LEVEL LOW WILL MOVE SOUTHWEST OF THE REGION TONIGHT INTO SUNDAY. THE UPPER LEVEL LOW WILL CONTINUE RETROGRADING TO THE SOUTHWEST DURING THE DAY ON SUNDAY. THIS WILL LEND ITSELF TO A WARMER DAY ACROSS THE AREA WITH HIGHS EXPECTED TO BE IN THE UPPER 80S.
THE REGION REMAINS IN AN AREA OF MID LEVEL TROUGHING BETWEEN A RIDGE OFF THE SOUTHEASTERN US COAST CENTERED TO THE SOUTH OF BERMUDA AND ANOTHER RIDGE CENTERED OVER THE DESERT SOUTHWEST OF THE CONUS. THIS SW CONUS RIDGE HAS BUILD NORTHEAST INTO THE GREAT LAKES REGION. A RIDGE OF HIGH PRESSURE EXTENDS FROM THE MID ATLANTIC STATES INTO THE APPALACHIANS.
CONVECTION WAS ALONG OR AHEAD OF COLD FRONT SLOWLY APPROACHING FORM THE NORTHERN PLAINS. THIS COLD FRONT WILL BE THE PRIMARY FEATURE FOR THE AREA TONIGHT INTO MONDAY. CLOUDS WORKING INTO NORTH CENTRAL WISCONSIN THIS AFTERNOON AHEAD OF THE FRONT WILL PRODUCE SLIGHTLY COOLER TEMPS AND HEAT INDEX NUMBERS. ATTENTION THEN TURNS TO THE CONVECTION WITH THE COLD FRONT PASSAGE. WILL TREND WITH THE HIGHER POPS ACROSS THE SOUTH HALF OF THE FORECAST AREA MONDAY AND DIMINISH FOR THE NORTH AS THE FRONT SHIFTS SOUTH.
A COLD FRONT WILL APPROACH THE AREA LATE IN THE WEEK. MAXIMUM TEMPERATURES A DEGREE OR 2 WARMER THAN YESTERDAY WILL RESULT IN READINGS VERY CLOSE TO EXPECTATIONS FOR MID AUGUST. ATLANTIC RIDGING WILL ALLOW FOR THE RETURN OF WARMER AND MORE HUMID CONDITIONS AS A SOUTHERLY RETURN FLOW TAKES HOLD. A WEAK WARM FRONT WILL LIFT NORTH TUE/WED AS THE FLOW INCREASES AND THE RIDGE ALOFT SHARPENS. HIGHER DEWPOINTS WILL ONLY ALLOW LOWS TO DROP INTO THE LOWER TO MID 70S. BERMUDA HIGH PRESSURE WILL BE ANCHORED OFFSHORE THROUGH THE PERIOD WITH WEAK RIDGING ALOFT ACROSS THE SOUTHEAST. AS THE WEAK WARM FRONT LIFTS FURTHER N ON WED. WILL SHOW POPS DECREASING AS WE MOVE INTO LATE WEEK WITH THE PIEDMONT TROUGH AND SEABREEZE THE ONLY APPARENT TRIGGERING MECHANISMS FOR SHOWERS AND THUNDERSTORMS.
418 AM MDT SUN AUG 16 2015 WATER VAPOR AND THETA SURFACES SEEM TO SUGGEST THE MOISTURE CIRCULATING THE SUBTROPICAL RIDGE IS ORIGINATING MORE FROM THE TROPICS THAN THE MONSOONAL REGION. THIS CENTRAL RIDGE IS LOCATED OVER THE LOWER DESERT SOUTHWEST EARLY THIS MORNING BUT IS ABOUT TO BE RELOCATING WESTWARD TO SOUTHERN CALI OVER THE NEXT 48 HRS. EXPECT RIDGE TOP CLOUDS TO BEGIN TO BLOSSOM BY EARLY AFTERNOON AS THE TERRAIN CIRCULATIONS AND MID LEVEL INSTABILITY STRENGTHENS.
HIGH PRESSURE TO REMAIN NORTH OF FLORIDA AND WILL KEEP CENTRAL FLORIDA IN A DEEP MOIST EASTERLY FLOW PATTERN. MESOSCALE PROCESSES SUCH AS SEA/LAKE BREEZES AND OUTFLOW BOUNDARIES FROM STORMS ALL INTERACTING WITH EACH OTHER PRODUCE SCATTERED TO NUMEROUS SHOWERS AND STORMS SUN AFTERNOON AND EVENING HIGHS IN THE UPPER 80S/AROUND 90 AT THE COAST AND THE LOWER 90S IN THE INTERIOR.
EXPECT THIS TO CONTINUE THIS MORNING WITH THE FRONT BANKING UP AGAINST THE HIGHER TERRAIN BY THIS AFTERNOON. CAPPING CREATED BY THE LOW LEVEL COOLER AIR MASS MAY HINDER ACTIVITY UNTIL LATER THIS EVENING WHEN AN IMPULSE APPROACHES THE AREA. HIGH TEMPS AROUND 20 DEGREES COOLER OVER THE PLAINS TODAY.
310 AM CDT SUN AUG 16 2015 (Today and Tonight) A broad upper level high will be centered over the Desert Southwest today and will move further west over the northern Baja. Through tonight, the forecast area will be situated between the upper high to our west and an inverted upper trough stretching from the Texas Gulf coast northeast over the lower Mississippi Valley to our east. Afternoon highs will be in the mid to upper 90s with morning lows tomorrow in the lower 70s.
THIS ACTIVITY IS ALSO CO-LOCATED WITH A SHEAR AXIS/UPPER LOW ON WATER VAPOR IMAGERY. THIS ELONGATED UPPER TROUGH FROM ALONG THE TX COAST NE THROUGH THE MISS RIVER VALLEY WILL BE THE MAIN REASON FOR THUNDERSTORM CHANCES GOING THROUGH THE REST OF THE WEEK.
A DRY NORTHWEST FLOW ALOFT WILL REMAIN OVER THE AREA WITH AN UPPER LEVEL RIDGE OFF THE WEST COAST AND AN UPPER LEVEL TROUGH TO OUR EAST. A DRY COLD FRONT WILL MOVE THROUGH ON MONDAY. UPPER LEVEL RIDGE OFF THE WEST COAST WILL KEEP REGION IN DRY NORTHWESTERLY FLOW ALOFT.
142 AM EDT SUN AUG 16 2015 WEAK HIGH PRESSURE WILL CONTINUE TO RESIDE OVER THE AREA INTO SUNDAY. UPPER LEVEL RIDGING PRODUCES A CAPPED ENVIRONMENT OVER MUCH OF THE FORECAST AREA SUNDAY. MAX TEMPERATURES WILL CONTINUE TO BE IN THE LOWER 90S WITH OVERNIGHT LOWS SUNDAY NIGHT A BIT WARMER AROUND 70 DEGREES. UPPER LEVEL HIGH PRESSURE WILL CONTINUE BUILDING INTO THE FORECAST AREA WITH A BROAD TROUGH LOCATED OVER THE CENTRAL US.
TODAY THROUGH MONDAY NIGHT UPPER LEVEL ANALYSIS HAS RIDGING OVER THE FAR SW CONUS WITH BROAD TROF ACROSS THE NORTHERN ROCKIES AND FAR NORTHERN PLAINS. LOW PRESSURE IS LOCATED ACROSS EASTERN SOUTH DAKOTA WITH COLD FRONT TRAILING ACROSS FAR SOUTHWEST SOUTH DAKOTA. BROAD UPPER LEVEL TROF WILL SLOWLY SHIFT EAST. WITH SURFACE COLD FRONT SAGGING SOUTH INTO NEBRASKA. HIGH TEMPERATURES TODAY WILL BE MUCH COOLER THAN YESTERDAY. AXIS OF UPPER LEVEL TROF WILL MOVE INTO THE AREA LATE IN THE DAY. PRECIP CHANCES INCREASE ACROSS THE ENTIRE AREA LATE MONDAY INTO MONDAY NIGHT AS THE UPPER TROF AXIS SHIFTS EAST.
THE HIGH PRESSURE THAT HAS KEPT MOST OF THE AREA DRY AND HOT FOR THE LAST FEW WEEKS IS NOW AROUND THE FOUR CORNERS REGION OF THE WESTERN UNITED STATES. ACROSS THE MISSISSIPPI RIVER VALLEY A TROUGH IS SETTING UP. THE SOUTHERN EDGE OF THIS TROUGH EXTENDS DOWN TO THE TEXAS LOUISIANA BORDER.
AN UPPER LEVEL RIDGE WILL CAUSE TEMPERATURES TO RISE WELL ABOVE NORMAL WITH HIGHS INTO THE UPPER 80S TO AROUND 90 DEGREES. A NARROW UPPER LEVEL RIDGE WILL BUILD OVER THE REGION TODAY. LATEST ECMWF HAS TRENDED AWAY FROM PRIOR/12 UTC PLAINS TROF ENERGY CUTOFF. A NARROW UPPER LEVEL RIDGE WILL BUILD OVER THE AREA TODAY AND SHOULD LIMIT STORM DEVELOPMENT.
A BROAD UPPER LEVEL TROUGH COVERS THE PACIFIC NORTHWEST AND NORTHERN ROCKIES WITH HIGH PRESSURE OVER CALIFORNIA AND THE GREAT BASIN. AT THE SURFACE, A THERMAL TROUGH IS DEVELOPING ALONG THE CALIFORNIA COAST AND SPREADING NORTH. THE HIGH TODAY IN BROOKINGS WAS 84. THE THERMAL TROUGH BREAKS DOWN A BIT LATER TODAY BUT RE-ESTABLISHES ON MONDAY.
OVERNIGHT LOWS WILL COOL INTO THE UPPER 60S TO THE LOWER 70S. HOWEVER, THE HIGH-RESOLUTION MODELS STILL SUGGEST SOME ISOLATED CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. SKIES SHOULD CLEAR OUT TOMORROW NIGHT WITH LOWS IN THE UPPER 60S TO THE LOWER 70S.
244 AM EDT SUN AUG 16 2015 HIGH PRESSURE BUILDS OVER THE REGION TODAY. THE HIGH WILL SHIFT THE THE COAST THIS WEEK AND BRING SUMMERTIME HEAT AND HUMIDITY THROUGH THE WEEK. HIGH PRESSURE BUILDS IN AT THE SURFACE. THE GFS AND ECMWF SHOW LOW PRESSURE LINGING ALOFT ALONG THE SOUTH COAST. HIGH PRESSURE WOULD SUGGEST CLEAR SKIES AND LIGHT WINDS. THE UPPER LOW AND A CORE OF COOLER TEMPS MIGHT SUGGEST SOME INSTABILITY ESPECIALLY ALONG THE SOUTH COAST. THE MIXED LAYER WILL REACH TO NEAR 825 MB SO MAX SURFACE TEMPS SHOULD BE A COUPLE OF DEGREES WARMER THAN INDICATED BY 850 MB TEMPS. HIGH PRESSURE OFFSHORE WILL MAINTAIN FAIR AND HUMID CONDITIONS.
THIS IS LIKELY RELATED TO A MID AND UPPER LEVEL LOW THAT IS SLOWLY MOVING EAST TO WEST ACROSS OUR REGION. AFTER THE UPPER LEVEL LOW MOVES INTO SOUTH TEXAS ON MONDAY.
A COLD FRONT WILL APPROACH THE AREA LATE IN THE WEEK. GIVEN THE LOW DEWPOINTS FOR THIS TIME OF YEAR.
water vapor imagery revealing broad upper ridging extending northeast across the Lwr Missouri Valley from parent high pressure located across the Desert Southwest. while our area remains in- between systems as a small scale disturbance continues to slowly drift south across the lower Ohio and Tennessee Vlys. Not a whole lot of change to today/s forecast as previously mentioned upper ridging and presence of dry air aloft will provide another sunny day with temps warming into the upper 80s to lower 90s. cold front to very slowly settle south into the upper Miss Vly as high pressure strengthens across the Northern Plains. overall low- level jet strength again looks weak so precip chances will be highest along the Iowa state line where low-level convergence into the inverted trough will likely be greatest.
AN UPPER LEVEL TROUGH CONTINUES OVER WESTERN CANADA LEAVING THE PACIFIC NORTHWEST IN A COOL BUT DRY CYCLONIC FLOW.
AN UPPER LEVEL RIDGE WILL CAUSE TEMPERATURES TO RISE ABOVE NORMAL TODAY WITH HIGHS WELL UP INTO THE 80S TO AROUND 90 DEGREES. OTRWS MID LVL RIDGE BLDS THROUGH THE PD. ENCROACHING MID LVL RIDGE AND LACK OF GUIDANCE SIGNAL WILL DEFER AN INSERTION AT THIS POINT.
517 AM EDT SUN AUG 16 2015 A STRENGTHENING RIDGE WILL BUILD INTO THE REGION OVER THE NEXT SEVERAL DAYS. THE RIDGE BUILDING IN FROM THE MIDWEST AND LOWER LAKES WILL PROVIDE ANOTHER WARM AND DRY DAY. THE UPPER RIDGE THAT STARTS TO DAY OVERHEAD WILL SLIDE OFF TO OUR EAST BY EVENING. THE PATTERN OVER THE EASTERN US WILL FAVOR A MEAN UPPER RIDGE WHICH WILL HANG TOUGH ALONG THE EASTERN SEABOARD.
648 AM EDT SUN AUG 16 2015 SOME OF THE WARMEST AIR OF THE SUMMER WILL BE OVER THE REGION THE NEXT FEW DAYS, AS HIGH PRESSURE EXPANDS OUT OF THE MIDWEST.
A WEAK UPPER TROUGH AXIS CURRENTLY STRETCHES FROM KY EASTWARD TOWARD THE MID ATLANTIC STATES.
351 AM EDT SUN AUG 16 2015 AN UPPER TROUGH WILL PERSIST ALONG THE LOWER MS VALLEY THROUGH THE SHORT TERM. AN INCREASE IN SOUTHERLY WINDS ON MONDAY WILL BRING A SURGE OF DEEPER MOISTURE NORTHWARD INTO THE FORECAST AREA AHEAD OF THE UPPER TROUGH.
401 AM CDT SUN AUG 16 2015 AN ELONGATED TROUGH EXTENDING FROM THE MID MISSISSIPPI VALLEY TO THE TEXAS COASTAL REGION WILL INCH WESTWARD TOWARDS NORTH TEXAS WHILE A MID AND UPPER RIDGE CURRENTLY CENTERED OVER ARIZONA HEADS FOR SOUTHERN CALIFORNIA.
121 AM EDT SUN AUG 16 2015 HIGH PRESSURE REMAINS OVER THE REGION THROUGH SUNDAY. HIGH PRESSURE REMAINS OVER THE REGION TONIGHT. MODELS NOT PICKING UP ON THE HIGHER DP TMPS CRNTLY BEING REPORTED W OF I95. COOLEST OVR INTERIOR SERN SCTNS WHERE DP TMPS ARE THE LOWEST. A MID/UPPER LEVEL ANTICYCLONE WILL REMAIN ANCHORED OVER THE MID- ATLANTIC REGION SUNDAY AND MONDAY. THE HIGH NUDGES OFFSHORE MONDAY AND THIS WILL ALLOW FOR SOME MODEST RETURN OF LOW- LEVEL MOISTURE. THE CURRENT EXPECTATION IS THAT HIGH PRESSURE ALOFT WILL SUPPRESS ANY SEA- BREEZE CONVECTION ACROSS NE NC/SE VA. HIGHS MONDAY RISE INTO THE LOW 90S INLAND.
THERE IS A COLD FRONT MOVING SOUTHEAST WITH A DECENT LOW LEVEL JET RUNNING INTO IT. FORCED BY THE COLD FRONT. THE COLD FRONT IS BEGINNING TO WORK THROUGH CORSON COUNTY /WITH BASICALLY STATIONARY PRE-FRONTAL SURFACE TROF STILL HANGING TOUGH FURTHER EAST FROM APPX KMBG TO KPIR/ CONDITIONS BEHIND THE COLD FRONT ARE JUST A TEENY-TINY BIT COOLER. FOR NOW WILL MAINTAIN CHC POPS ALONG COLD FRONT WITH CAP WEAKENING OVER TIME.
UPPER RIDGING REMAINS SITUATED FROM THE DESERT SW INTO TO CENTRAL HIGH PLAINS. A COLD FRONT STRETCHES FROM EASTERN ND DOWN INTO WY WITH HIGH PRESSURE REMAINING OVER THE MID-ATLANTIC STATES. COLD FRONT IS EXPECTED TO CONTINUE PUSHING SOUTH TODAY AND BY THE EARLY EVENING WILL BE SITUATED FROM NORTHERN IA DOWN INTO EXTREME NW KS. CONFIDENCE IN AREAL COVERAGE IS LOW AS THE COLD FRONT WASHES OUT OVER NORTHERN KS. THE COLD FRONT IS THEN EXPECTED TO MOVE THROUGH TUE AFTERNOON-EVENING AND WILL PROVIDE A MORE FOCUSED CHANCE FOR STORMS AS IT PUSHES SOUTH.
352 AM CDT SUN AUG 16 2015 UPPER RIDGE WILL HOLD SWAY TODAY INTO MONDAY.
FOR SUNDAY SHRA/TSRA WILL ONCE AGAIN DEVELOP DUE TO DAYTIME HEATING AND AN UPPER TROF ACROSS THE REGION.
DEEP LAYER RIDGING IS STILL EXPECTED TO BE THE DOMINANT SYNOPTIC FEATURE ACROSS THE AREA THROUGH THE UPCOMING WEEK AS IT GRADUALLY SLIDES TO THE WEST FROM THE WESTERN ATLANTIC EVENTUALLY CENTERING OVER THE EASTERN GULF OF MEXICO.
STRONG UPPER LEVEL HIGH PRESSURE WILL MAINTAIN VERY HOT AND DRY CONDITIONS ACROSS MUCH OF THE REGION TODAY. A COOLING TREND WILL BEGIN MONDAY AND CONTINUE THROUGH MIDWEEK AS HIGH PRESSURE WEAKENS AND ONSHORE FLOW STRENGTHENS.
A weak upper level trough will be the dominant weather feature today and Monday, but impacts will be relatively minor. The air mass will be just a little cooler than normal under this feature. Weak westerly flow aloft, and slight ridging, will develop through the middle of the week, allowing temperatures to rise back to near normal mid-August levels.
400 AM EDT SUN AUG 16 2015 HIGH PRESSURE WILL GRADUALLY SLIDE EASTWARD AWAY FROM THE REGION OVER THE NEXT FEW DAYS BUT WILL RETAIN OVERALL CONTROL THROUGH MIDWEEK. A COLD FRONT MAY APPROACH THE AREA FROM THE NORTHWEST LATE IN THE WEEK. A WEAK TROUGH AXIS EXTENDS ALONG THE EASTERN SEABOARD. ATTACHING TO A CLOSED LOW OVER THE LOWER OHIO VALLEY.
144 AM EDT SUN AUG 16 2015 HIGH PRESSURE DOMINATES WITH WEAK WIND FLOW TODAY.
243 AM EDT SUN AUG 16 2015 SOME OF THE WARMEST AIR OF THE SUMMER WILL BE OVER THE REGION THE NEXT FEW DAYS, AS HIGH PRESSURE EXPANDS OUT OF THE MIDWEST.
418 AM EDT SUN AUG 16 2015 A STRENGTHENING RIDGE WILL BUILD INTO THE REGION OVER THE NEXT SEVERAL DAYS. THE RIDGE BUILDING IN FROM THE MIDWEST AND LOWER LAKES WILL PROVIDE ANOTHER WARM AND DRY DAY. THE UPPER RIDGE THAT STARTS TO DAY OVERHEAD WILL SLIDE OFF TO OUR EAST BY EVENING. THE PATTERN OVER THE EASTERN US WILL FAVOR A MEAN UPPER RIDGE WHICH WILL HANG TOUGH ALONG THE EASTERN SEABOARD.
OVERNIGHT LOWS A FEW DEGREES WARMER THEN LAST NIGHT WITH SUBTLE WARM ADVECTION TODAY AND ABOVE BOUNDARY LAYER TONIGHT. CURRENTLY HAVE AN AREA OF LOW PRESSURE CENTERED ACROSS SRN MANITOBA AND SASKATCHEWAN. THIS WILL PUSH INTO SOUTHERN ONTARIO SUNDAY EVENING WITH THE ASSOCIATED COLD FRONT TO PUSH INTO NORTHWESTERN IOWA AND THE NORTHWESTERN CWA BY LATE SUNDAY.
Although the flow aloft will remain fairly weak across the Western High Plains, steep low/mid level lapse rates and SBCAPE values in excess of 1000 J/KG will be enough to support thunderstorms in the vicinity of the trough axis and approaching cold front. Look for highs up into the lower to mid 90s(F) once again this afternoon. The potential for severe weather will increase as well as dynamic support aloft becomes more favorable as a +70kt jet core streams east across the Colorado Rockies into the high plains.
A LONG WAVE UPPER LEVEL KICKER TROUGH IS JUST OFF THE PACIFIC NORTHWEST COAST AND THE KICKEE FORMER CUTOFF LOW IS NOW LIFTING NORTH THROUGH NORTHWEST NEVADA. THE TROUGH WILL MOVE ONSHORE THIS EVENING. THE TROUGH WILL PARTIALLY SHEAR AS IT DOES SO. THE ASSOCIATED COLD FRONT IS NOW MOVING THROUGH THE AREA. IT WILL BE A LOT COOLER TODAY. THE PARTIAL SHEARING WILL ACT TO SLOW THE UPPER TROUGH DOWN.
SUBJECTIVE 12Z UPPER AIR ANALYSIS INDICATES CONTINUED EASTERN US UPPER-LEVEL TROUGH. WESTERN RIDGE. 850MB RIDGE AXIS EXTENDED FROM EASTERN TX THROUGH THE IA/NEB BORDER AND THE DAKOTAS.
WEAK SOUTHEASTERLY FLOW ON THE BACKSIDE OF THE RIDGE CONTINUED ACROSS WESTERN NEBRASKA. UPPER RIDGING WILL BUILD INTO WRN NEBR THROUGH TONIGHT AS AN UPPER TROUGH MOVES INLAND FROM THE WEST COAST. MUCH WARMER H85 TEMPS MOVE INTO WRN NEBR TONIGHT WARMING TO 13C-16C BY 12Z SUNDAY.
Tonite, the High pressure center will slide southeastward across the Quad State and center near KEVV by 12z Sunday.
AIDED IN PART BY AN AMPLIFIED H5 RIDGE THAT SHIFTS EASTWARD FROM THE EASTERN ROCKIES OUT INTO THE CENTRAL PLAINS DURING THIS TIME. MODELS DO BRING A CUTOFF UPPER LOW SOUTHWARD ALONG THE PACIFIC COASTLINE AS WELL DURING THE AFOREMENTIONED TIMEFRAME. BUT WITH THE REGION SEEING HIGH PRESSURE DOMINATING THE AREA/S WEATHER. BLOCKING ANY MOISTURE FROM THE CUTOFF TO MOVE EAST THRU THE ROCKIES THE CWA WILL SEE NO CHANCE FOR RAIN AS A RESULT. THE LEE-SIDE TROUGH WILL SHIFT EASTWARD OFF THE FRONT RANGE LATE IN THE DAY SUNDAY SETTING UP OVER WESTERN PORTIONS OF THE CWA.
WARMING TREND CONTINUES WITH A RIDGE ALOFT MOVING OVERHEAD.
LOW PRESSURE ALOFT WILL BRING THE POSSIBILITY OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS AND DESERTS THROUGH SUNDAY.
358 PM EDT SAT OCT 17 2015 A DEEP UPPER LEVEL TROUGH OVER EASTERN CANADA AND THE NORTHEAST CONUS WILL BRING BELOW NORMAL TEMPERATURES TO CENTRAL PA THIS WEEKEND. WIDESPREAD NIGHTTIME FREEZING CONDITIONS WILL LIKELY END THE GROWING SEASON. THE 850MB THERMAL TROUGH /-4C TO -8C/ WILL MOVE THROUGH ON SUNDAY WITH ONE MORE DAY OF SEASONABLY COLD.
HIGH PRESSURE OVER THE EASTERN DAKOTAS WILL CONTINUE TO MOVE EAST TODAY AS LOW PRESSURE DEVELOPS IN THE LEE OF THE NORTHERN ROCKIES. AN H5 RIDGE ACROSS THE WESTERN UNITED STATES WILL BEGIN BUILDING INTO THE NORTHERN PLAINS.
303 PM EDT SAT OCT 17 2015 COLD CANADIAN HIGH PRESSURE GIVES WIDESPREAD FROST AND FREEZE TONIGHT AND SUNDAY MORNING.
Unseasonably warm today, followed by rainy, cooler. Snow levels will stay high enough that only a light dusting could be possible in the highest terrain.
1212 PM CDT SAT OCT 17 2015 TEMPERATURES THIS MORNING HAVE CLIMBED BACK TO THE FREEZING MARK OR ABOVE ACROSS ALMOST THE ENTIRE AREA.
HIGH PRESSURE. RADIATIONAL COOLING TONIGHT WILL ALLOW FOR TEMPS TO DROP AT OR BELOW FREEZING IN MANY PLACES ON NORTHERN PLATEAU. WITH HIGH TEMPS IN THE LOWER 50S TO LOWER 60S. WARMER TEMPERATURES ARE EXPECTED SUNDAY NIGHT.
315 PM CDT SAT OCT 17 2015 TEMPS IN THE LOWER TO MID 80S THIS AFTERNOON WITH CIRRUS MOVING ACROSS SE AREAS. THIS WILL SET THE STAGE FOR A HEAVY RAINFALL THREAT AS A DEEP MID/UPPER TROUGH APPROACHES FROM THE WEST. THIS LOW WILL CAUSE A TIGHT SFC PRESSURE GRADIENT ACROSS THE UPPER COAST AND ALLOW FOR INCREASING WINDS AND GOOD INFLOW.
WITH THE GREATEST CHANCE NORTH OF I-80 AND IN THE RIDGES. HIGH PRESSURE WILL START TO BUILD OVER THE OHIO VALLEY SUNDAY.
AN UPPER LEVEL LOW OFFSHORE OF SOUTHERN OREGON WILL CONTINUE THE THREAT FOR SHOWERS THROUGH THE WEEKEND AS IT SLOWLY MOVES INLAND.
HIGH PRESSURE WILL BE SETTLING SOUTHEAST INTO THE MID MISSISSIPPI VALLEY WITH LIGHT SOUTHERLY FLOW LIFTING INTO CENTRAL IOWA.
PERIODS OF SHOWERS ARE THEN ANTICIPATED TO CONTINUE SUNDAY AS THE TROUGH AND EMBEDDED CLOSED LOW DRAWS EVER CLOSER.
UPPER LOW LIFTING INTO THE GREAT BASIN THIS AFTERNOON.
A COLD FRONT WILL PASS OVER THE FORECAST AREA TODAY BRINGING THE POSSIBILITY OF SHOWERS AND THUNDERSTORMS. DRY WEATHER WILL RETURN ON SUNDAY AS HIGH PRESSURE BUILDS IN OVER THE EAST PACIFIC.
MOST LOCATIONS WILL GET SUBFREEZING BY DAWN SUNDAY.
232 PM EDT SAT OCT 17 2015 A DEEP UPPER LEVEL TROUGH OVER EASTERN CANADA AND THE NORTHEAST CONUS WILL BRING BELOW NORMAL TEMPERATURES TO CENTRAL PA THIS WEEKEND. WIDESPREAD NIGHTTIME FREEZING CONDITIONS WILL LIKELY END THE GROWING SEASON. THE 850MB THERMAL TROUGH /-4C TO -8C/ WILL MOVE THROUGH ON SUNDAY WITH ONE MORE DAY OF SEASONABLY COLD.
RELATIVELY HIGH AMPLITUDE UPPER LEVEL RIDGE OVER MT/SASK WILL FLATTEN AND MOVE OVER THE AREA SUN. UPPER TROUGH OFF THE WEST COAST OF NORTH AMERICA WILL SHEAR OFF AND CREATE A SPLIT FLOW OVER NORTH AMERICA WITH NORTHERN STREAM OVER SOUTHERN CANADA AND SOUTHERN STREAM OVER THE SOUTHERN STATES. UPPER TROUGH OFF THE WEST COAST WILL MOVE ACROSS SOUTHERN CANADA MON AND SEND A COLD FRONT INTO THE AREA LATE SUN/EARLY MON.
345 PM CDT SAT OCT 17 2015 12Z UPPER AIR ANALYSIS SHOWED A BROAD UPPER LEVEL RIDGE AXIS EXTENDING FROM WEST CENTRAL TEXAS TO THE NORTHWEST OVER THE IDAHO/MONTANA BORDER. IMPINGING UPON THE UPPER RIDGE AXIS. A COOL START TO THE DAY COMBINED WITH SOME CIRRUS CLOUDS OVER THE REGION HAVE KEPT AFTERNOON TEMPERATURES A BIT COOLER.
UPPER LEVEL WINDS ARE NORTHWESTERLY ON THE BACK SIDE OF THE TROUGH MOVING ACROSS THE EAST COAST. THIS WILL KEEP RH IN THE LOWER 20S THIS AFTERNOON.
Dew points remain very dry with readings from the low 20s in some eastern Ozarks locations to the low 30s out west. We are expecting lows to dip down into the low to mid 30s once again out there, and would not be surprised to see some valleys dip into the upper 20s again like last night. Will not be going with Freeze Warning as only isolated areas (mainly low lying areas) are expected to dip below freezing and a hard freeze is not expected there either. Warm up is expected to begin on Sunday as we see upper level ridge begin to nudge eastward into our area along with low level warm advection with the departing Canadian air mass to the east.
Radiational cooling should allow much of the region to bottom out in the lower 30s with widespread frost, and parts of southeast Missouri and southern Illinois closer to 30. Current frost advisory has much of this covered well, and will change the aforementioned SE MO and SRN IL to a freezing warning where the coldest readings are expected. trof moving into the Atlantic, upper ridging into the Nation's midsection and deep trofing aloft in the western CONUS.
430 PM EDT SAT OCT 17 2015 LOW PRESSURE WILL TRACK EAST THROUGH THE MARITIMES TONIGHT.
/ISSUED 257 PM CDT SAT OCT 17 2015/ Surface ridging is providing a seasonally cool and dry day across the region.
210 PM PDT SAT OCT 17 2015 LOW PRESSURE ALOFT WILL BRING THE POSSIBILITY OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS AND DESERTS THROUGH SUNDAY.
MAIN AVIATION ISSUE WILL CONTINUE TO BE ELEVATED NERLY WINDS WITH TIGHT GRADIENT/CAA BEHIND DEPARTING COLD FRONT. HIGH PRESSURE CONTINUES TO BUILD IN BEHIND A COLD FRONT WHICH WAS MOVING OFF OUR LOUISIANA AND SOUTHEAST TEXAS OFFSHORE COASTAL WATERS. COLD AIR ADVECTION OFFSET BY DAYTIME FALL SOLAR INSOLATION SHOULD RESULT IN AFTERNOON TEMPERATURES AROUND 8-12 DEGREES COOLER THAN YESTERDAY. HIGH PRESSURE WORKING INTO THE REGION IN THE WAKE OF OUR LATEST FRONTAL PASSAGE WILL YIELD NORTHEASTERLY WINDS. /ISSUED 431 AM CDT SAT OCT 17 2015/ WINDS HAVE REMAIN UP OVERNIGHT AND THIS HAS HELP MIX THE LOWER ATMOSPHERE ENOUGH TO HOLD TEMPERATURES IN THE LOWER 60S. CLEAR SKIES WILL PREVAIL TODAY OVER THE REGION AS HIGH PRESSURE ALOFT AND AT THE SURFACE WILL DOMINATE THE WEATHER PATTERN OVER THE WEEKEND AND INTO THE COMING WEEK AHEAD.
A LONG WAVE UPPER LEVEL KICKER TROUGH IS JUST OFF THE PACIFIC NORTHWEST COAST AND THE KICKEE FORMER CUTOFF LOW IS NOW LIFTING NORTH THROUGH NORTHWEST NEVADA. THE TROUGH WILL MOVE ONSHORE THIS EVENING. THE TROUGH WILL PARTIALLY SHEAR AS IT DOES SO. THE ASSOCIATED COLD FRONT WILL MOVE ONSHORE LATER TODAY. IT WILL BE A LOT COOLER TODAY. THE PARTIAL SHEARING WILL ACT TO SLOW THE UPPER TROUGH DOWN.
WEAK COLD FRONT, STALLED BOUNDARY, SITS JUST TO THE NORTH OF OUR REGION WILL SLOWLY SLINK THROUGH OUR NECK OF THE WOODS LATER THIS MORNING BRINGING A NOTICEABLY DRIER AIRMASS WITH IT. DEWPOINTS ARE EXPECTED TO MIX OUT DURING PEAK HEATING INTO THE UPPER-50S IN A LOT OF PLACES, WHILE THE EASTERLY ONSHORE FLOW KEEPS THEM A TOUCH WARMER, BUT NOT UNCOMFORTABLE, IN THE LOW-60S ALONG THE COAST.
159 PM EDT SAT OCT 17 2015 COLD CANADIAN HIGH PRESSURE GIVES WIDESPREAD FROST AND FREEZE TONIGHT AND SUNDAY MORNING.
WITH COOLER AND QUITE DRY AIR. EARLY MORNING TEMPS WERE IN THE LOWS 40S NORTH.
With the pressure gradient relaxing as center of the high approaches, winds will taper off under clear skies, allowing for radiational cooling to send temperatures into the 20s for most rural locations, and into the lower 30s for more urban areas. Even so, temperatures will remain 10 to 15 degrees below normal, with readings from the lower 50s to around 60. As the high continues its eastward progression, return southerly flow will initiate a moderation in temperatures overnight, but not before temperatures again dip into the 30s.
RIDGING WILL MOVE OVERHEAD COMPLETE WITH HEIGHT RISES. SURFACE RIDGING WILL BEGIN TO LOOSEN ITS GRIP TODAY WITH WEAK SURFACE CYCLOGENESIS IN SOUTHEASTERN COLORADO.
AND THE SLIGHTLY WARMER TEMPERATURES AND BREEZY SOUTHWEST WINDS EXPECTED DURING THE DAY SUNDAY. UPPER LEVEL RIDGE AXIS CURRENTLY SITUATED OVER MINNESOTA WILL SHIFT TO THE EAST TONIGHT WITH THE TRAILING EDGE OF THE COLD AIR MASS LINGERING OVER PORTIONS OF THE WRN GREAT LAKES AND COMBINING WITH CLEAR SKIES AND CALM/LIGHT WINDS TO PRODUCE TEMPERATURES IN THE 20S ONCE AGAIN. AS THE HIGH PRESSURE MOVES EWD ON SUNDAY. A WARMER AIR MASS WILL BEGIN TO ADVECT IN FROM THE SW. THE DRY AIR MASS UNDER THE RIDGE WILL ALLOW SKIES TO REMAIN MOSTLY SUNNY THROUGH THE DAY SUNDAY. TEMPERATURES WILL ALSO BE A BIT COOLER AROUND THE LAKE AND COOK COUNTY AREA. WITH UPPER LEVEL RIDGING ACROSS THE NORTHLAND.
SHORT TERM: (Through Late This Afternoon) As expected temperatures are dropping into the middle to upper 30s as high pressure builds into the central CONUS.
HIGH PRESSURE AT THE SURFACE AND ALOFT IS PRODUCING CLEAR SKIES ACROSS THE NORTHERN PLAINS LATE THIS AFTERNOON. EVEN WITH THE WARMER TEMPERATURES WE ARE STILL SEEING LOWEST HUMIDITIES AROUND 35 PERCENT IN THE JAMES RIVER VALLEY SUNDAY AFTERNOON.