Aikyam-Lab/Synoptic-Bench huggingface dataset:
1147 AM CST WED JAN 21 2015 HIGH PRESSURE CONTINUES OVER THE AREA THIS MORNING. HIGH PRESSURE IS OVER THE NORTHERN ROCKIES THIS MORNING AND WILL KEEP THINGS DRY OVER THE FORECAST AREA TODAY AND MOST OF TONIGHT. BY LATE TONIGHT LOW PRESSURE DEVELOPS OVER SOUTH TEXAS. AS THE LOW GETS CLOSER TO THE FORECAST AREA THERE WILL BE A BETTER CHANCE OF LIGHT RAIN. PRECIPITATION WILL CONTINUE TO FALL OVER THE REGION AND WITH TEMPERATURES DROPPING CLOSE TO FREEZING THERE COULD BE A MIX OF RAIN AND SNOW ESPECIALLY OVER NORTHERN SECTIONS OF THE FORECAST AREA.
A ridge of high pressure aloft currently centered just inland of the West Coast will gradually shift east today, maintaining a dry and stable northerly flow aloft over the region through tonight.
DEEPENING 500 MB TROUGH DIGGING FROM THE SOUTHWEST UNITED STATES TOWARD THE TEXAS BIG BEND AND STATIONARY FRONT NORTH OF THE AREA AGAIN BECOMING MOBILE WILL RESULT IN INCREASED PRECIPITATION CHANCES WITHIN THE BRO CWFA THE NEXT 24 HOURS. COLD FRONT PUSHES FROM WEST TO EAST THROUGH DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY WHILE THE 500 MB TROUGH CONTINUES TO ADVANCE INTO TEXAS. BUT WILL BE TEMPERED BY THE ADVANCE OF THE COLD FRONT. THE APPROACH OF HIGH PRESSURE FROM THE UPR VALLEY WILL HELP DEFINE A COASTAL TROUGH OFFSHORE. AND BETTER LIFT SHOULD OCCUR ALONG THE WESTERN EDGE AS IT SHIFTS FARTHER OFFSHORE AHEAD OF THE SURGING HIGH PRESSURE.
HIGH AND MIDLEVEL CLOUDS WILL BE INCREASING THROUGH THE DAY AS THE APPROACHING LOW PRESSURE SYSTEM MOVES EAST ACROSS TX.
DUE TO TEMPERATURES HOVERING ONLY A COUPLE OF DEGREES BELOW FREEZING AT MOST LOCATIONS. ALSO FOLLOWED THE WARMER MOS VALUES FOR THAT PERIOD.
KLRD MAY REMAIN DRY THURS MRNG AS A COLD FRONT SLIDES THRU THE AREA.
WE ARE FINALLY STARTING TO SEE A CHANGEOVER AND EXPECT THIS TREND TO CONTINUE AS TEMPERATURES FALL TO NEAR FREEZING. STILL THINKING THE HIGHEST SNOWFALL AMOUNTS WILL OCCUR IN THIS AREA AS THERE IS A GOOD POSSIBILITY THAT A DISTINCT SNOW BAND WITH HEAVIER SNOW WILL SET UP SOMEWHERE BETWEEN VEGA. CURRENT TEMPERATURES ARE QUITE WARM IN THE 40S SO IT WILL TAKE SOME TIME TO COOL THINGS DOWN TO NEAR OR AT FREEZING EVEN AFTER SUNSET.
THIS EVENING THROUGH THURSDAY NIGHT UPPER LEVEL ANALYSIS HAS POSITIVELY TILTED TROF ACROSS THE CENTRAL CONUS WITH HIGH AMPLITUDE RIDGE MOVING ONTO THE WEST COAST. UPPER TROF AXIS ACROSS THE NORTHERN PLAINS IS JUST SHIFTING SOUTH OF THE DAKOTAS. TAIL END OF WEAK COLD FRONT REMAINS ACROSS SOUTHERN SOUTH DAKOTA WITH HIGH PRESSURE BUILDING IN FROM THE NORTH. UPPER TROF QUICKLY SHIFTS SOUTHEAST AS RIDGE BUILDS ACROSS THE ROCKIES. UPPER RIDGE QUICKLY BUILDS INTO THE NORTHERN PLAINS AS SOUTHWEST BOUNDARY LAYER FLOW PICKS UP. UPPER RIDGE CONTINUES TO BUILD INTO THE NORTHERN PLAINS THURSDAY NIGHT.
343 PM EST WED JAN 21 2015 A TROUGH WILL BE ACROSS OHIO AND WESTERN PENNSYLVANIA TONIGHT AND THURSDAY MORNING BEFORE A RIDGE BUILDS IN.
18Z SFC ANALYSIS HAS A WEAK LOW EAST OF KMLI WITH A BOUNDARY/TROF EAST ACROSS ILLINOIS AND ANOTHER FROM THE LOW INTO NORTHERN IOWA. A COLD FRONT RAN FROM THE STRAITS OF MACKINAC INTO SOUTHWEST WISCONSIN AND THEN ACROSS NORTHERN IOWA.
AREAS OF FLURRIES OR FREEZING DRIZZLE ARE EXPECTED ON EITHER SIDE OF THE BAND OF SNOW SHOWERS. STILL THINK FLURRIES AND FREEZING DRIZZLE WILL END FROM NORTH TO SOUTH THROUGH EARLY EVENING. THERE WAS SOME LIGHT SNOW ACROSS THE INTERNATIONAL BORDER REGION AS A WEAK COLD FRONT MOVES THROUGH THAT AREA. THERE HAS ALSO BEEN SOME PATCHY FREEZING DRIZZLE BUT NO ROAD ISSUES AT THIS POINT.
DETERIORATING WEATHER CONDITIONS WILL OCCUR AT ALL TERMINAL SITES THRU 12Z THURSDAY AS AN UPPER LEVEL LOW PRESSURE STORM SYSTEM AFFECTS THE REGION. TODAY AND TONIGHT EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWS AND UPPER-LEVEL TROUGH OVER THE GREAT BASIN. IN THIS AREA TEMPERATURES WILL BE NEAR OR BELOW THE FREEZING MARK.
211 PM CST WED JAN 21 2015 UPPER LOW CURRENTLY MOVING THROUGH AZ WILL CONTINUE TO PUSH EASTWARD ESPECIALLY ACROSS EAST CENTRAL/SOUTHEAST OKLAHOMA. FORECAST POINT SOUNDINGS ACROSS EAST CENTRAL OK SUGGEST LOW LEVEL TEMPERATURES PROFILES WILL FALL TO NEAR FREEZING IN THE HEAVIER PRECIP TONIGHT WITH THE POTENTIAL FOR RAIN TO TRANSITION TO SNOW.
WILL SEE LITTLE CHANGE IN THE HIGH TEMPERATURES FOR TODAY. IT SHOULD BE A COUPLE DEGREES COOLER ACROSS MOST OF THE CWA. BUT THE SE PART OF THE CWA MAY BE A FEW DEGREES WARMER THAN YESTERDAY. HOWEVER THERE IS A SLIGHT POSSIBILITY THAT SOME EVAPORATIVE COOLING AT THE ONSET COULD BRING A RAIN/SNOW MIX IN THE HIGHEST ELEVATIONS OF THE NORTH MOUNTAINS. HOWEVER WITH TEMPS REMAINING ABOVE FREEZING DO NOT EXPECT ANY ACCUMULATION THURSDAY NIGHT.
AT THE SURFACE, A WEAK COLD FRONT WILL SLOWLY MOVE THROUGH NORTHERN AND CENTRAL FLORIDA THIS AFTERNOON. HIGH PRESSURE TONIGHT BEHIND THIS FRONT THROUGH THE SOUTHEAST CONUS, WILL BE RESPONSIBLE FOR A MORE CONSISTENT EASTERLY BREEZY INTO THURSDAY MORNING.
ACTIVE ERN PACIFIC/WRN CANADA FLOW WILL CONTINUE TO DEVELOP AND REINFORCE ERN CONUS MEAN TROUGH.
The NAM is significantly cooler than the GFS, probably too cool as it produces quite a bit more dynamic cooling than the GFS does.
SIGNIFICANT WINTER STORM TO IMPACT THE SOUTH PLAINS REGION THIS MESHING OF NORTHERN STREAM UPPER TROUGH DIGGING SOUTH INTO THE SOUTHERN ROCKIES AND SOUTHERN STREAM SYSTEM MIGRATING ACROSS THE DESERT SOUTHWEST CONTINUES TO TAKE SHAPE THIS AFTERNOON. A RAIN/SNOW MIX SHOULD CONTINUE EAST OF THE CAPROCK ESCARPMENT THURSDAY AS DIURNAL HEATING ATTEMPTS TO WARM TEMPERATURES INTO THE LOW-MID 30S.
258 PM CST Wed Jan 21 2015 Quiet weather is expected to continue across the region for the next several days as a longwave trough sinks down the High Plains and eventually exits later this week. Cooler air associated with the trough has already begun filtering into the region; however, surface heating has not only allowed temperatures to climb into upper 40s to lower 50s, but has also resulted in enough low-level instability to produce a fairly widespread cu field across much of the CWA.
However, we will have the potential for some of this rain to possibly mix with snow as soundings continue to show cooling aloft, and temperatures will approach freezing mainly west of a Sweetwater, to Anson, to Throckmorton line. In these areas, if enough of the precipitation can change to snow and is heavy enough, there could be light accumulations on bridges, overpasses, other elevated surfaces, and some grassy areas. Although the upper level low will continue to approach the area tomorrow, better lift will affect areas to our east and south.
AN UPPER LEVEL TROUGH IS MOVING EAST ACROSS ARIZONA WHILE ANOTHER UPPER LEVEL TROUGH IS DROPPING SOUTH ACROSS THE GREAT BASIN. HOWEVER PATCHY RAIN WILL PERSIST INTO THURSDAY NIGHT AS THE GREAT BASIN TROUGH APPROACHES WESTERN TEXAS.
1139 AM CST WED JAN 21 2015 LOW PRESSURE OVER NORTHEASTERN IA WILL MOVE TO THE UPPER OH RIVER VALLEY THIS AFTERNOON. HIGH PRESSURE WILL DOMINATE THE AREA TONIGHT INTO THE WEEKEND.
HIGH PRESSURE EXTENDS FROM THE NORTHERN INTERMOUNTAIN INTO THE CENTRAL HIGH PLAINS. LOW PRESSURE IS STRENGTHENING OVER EXTREME SW TX INTO SOUTHERN NM. STRONG NW FLOW IS THEN EXPECTED TO TAKE UP RESIDENCE OVER THE PLAINS FOR THE WEEKEND AS UPPER RIDGING STRENGTHENS OVER THE WESTERN CONUS SETTING UP A VERY STABLE PNA PATTERN.
A WEAK UPPER LEVEL DISTURBANCE PASSING THROUGH THE RIDGE ON THURSDAY IS NOT EXPECTED TO CONTAIN ENOUGH ENERGY TO BREAK THE INVERSION.
BUT COULD STALL AS UPPER LEVEL TROUGH DIGS THROUGH THE 4 CORNERS. MAINLY THE HIGHER TERRAIN SOUTH OF INTERSTATE 70. UPPER LEVEL LOW WILL BE OVER THE SOUTHERN ROCKIES COME THURSDAY MORNING.
140 PM EST WED JAN 21 2015 A PRESSURE RIDGE WILL BE NORTH OF THE FORECAST AREA TONIGHT AND THURSDAY. AN INCREASE IN MOISTURE WILL OCCUR THURSDAY NIGHT AHEAD OF LOW PRESSURE DEVELOPING NEAR THE TEXAS GULF COAST.
1248 PM EST WED JAN 21 2015 A LARGE AREA OF HIGH PRESSURE OVER EASTERN CANADA AND THE NORTHEAST PLENTY OF SUNSHINE. A LOW PRESSURE SYSTEM WILL PASS TO OUR SOUTH ON THURSDAY WITH ONLY CLOUDS EXPECTED AND TEMPERATURES A FEW DEGREES BELOW SEASONAL NORMALS.
Northwest flow pattern persists over the area today while a fairly strong short wave trough is developing over the four corners through Thursday morning.
1234 PM EST WED JAN 21 2015 LOW PRESSURE WILL MOVE ACROSS THE AREA TODAY. HIGH PRESSURE WILL BUILD IN TO END THE WEEK. ENDED UP EXTENDING FREEZING RAIN ADVISORY UNTIL 11 AM AS SHALLOW LAYER OF WARM AIR AROUND H925 CONTINUES TO CAUSE SUFFICIENT MELTING FOR FZRA. THOUGH BROAD UPR TROFG WL RMN KEEPING CHCS FOR SNW SHWRS IN THE FCST. MDLS HAVE TRENDED FURTHER NW WITH THE WRN SHEILD OF PCPN ASSOCIATED WITH THE LOW. THE FIRST HALF OF NXT WEEK CONTS TO LK UNSETTLED AND DREARY WITH MDLS MAINTAINING A HIGH AMPLITUDE TROF OVR ERN NORTH AMERICA WITH SHRTWVS PROGRESSING THROUGH THE BASE.
REMOVED FREEZING FOG WORDING FROM THE SHASTA VALLEY AS OBS FROM KSIY AND KMHS BOTH SHOW CLEAR SKIES. FOR MORE DETAILS ON THE WEAK FRONT AND THE REDEVELOPING RIDGE, SEE THE PREVIOUS DISCUSSION BELOW. THE THERMAL TROUGH WILL WEAKEN AND SHIFT TO THE SOUTH TODAY, ALLOWING WINDS AND SEAS TO DIMINISH.
A VERTICALLY STACKED LOW PRESSURE SYSTEM OVER NE IA WAS MOVG ESE EARLY THIS MORNING. A LIGHT MIX OF SNOW AND FREEZING DRIZZLE WAS OCCURRING SW OF A LINE FROM CWA-PCZ-OSH. AS THE UPPER LOW SHIFTS THROUGH FAR SOUTHERN WI THIS MORNING. THIS WILL COME TO AN END AS HIGH PRESSURE BUILDS INTO THE REGION LATE TONIGHT. THIS HIGH.
DESPITE THE COOLER AIR MASS. THIS WILL SET THE STAGE FOR SOME RIDGE/VALLEY TEMPERATURE SPLITS TONIGHT. OPTED TO STAY ABOVE GUIDANCE AGAIN FOR THURSDAY AND GO WITH HIGHS NEAR SEASONABLE VALUES IN THE LOW TO MID 40S.
303 PM EST WED JAN 21 2015 HIGH PRESSURE WILL BUILD BY TO OUR NORTH TONIGHT.
325 PM EST WED JAN 21 2015 HIGH PRESSURE WILL BUILD ACROSS THE REGION TONIGHT.
LIGHT SNOW SHOWER ACTIVITY HAS ENDED IN FAR EASTERN MT AS STRONG UPPER LEVEL RIDGE BUILDS IN FROM THE WEST. THIS RIDGE WILL BRING DRY WEATHER THROUGH TOMORROW. LEE SIDE TROF WILL CONTINUE THRU TONIGHT.
200 PM PST WED JAN 21 2015 A HIGH PRESSURE RIDGE WILL BUILD OFF THE COAST THE REST OF THIS WEEK.
NORTH WINDS WILL PREVAIL THROUGHOUT THE DAY AS HIGH PRESSURE BUILDS INTO THE REGION. DESPITE THE PASSAGE OF A COLD FRONT. CLEAR SKIES AND NORTH-NORTHWEST TO NORTH-NORTHEAST WINDS AROUND 5-10 KTS ARE EXPECTED THIS AFTERNOON BEHIND A COLD FRONT. GIVEN THE HIGH CLOUDS AND DRY LOW-LEVELS OF THE ATMOSPHERE. CIGS WILL GRADUALLY LOWER THURSDAY MORNING AS LOW PRESSURE BEGINS TO DEVELOP OFF THE TEXAS GULF COAST.
WITH LIGHT WINDS AND A COOLER AIRMASS IN PLACE ACROSS THE REGION. WITH SLIGHTLY WARMER AIR BEGINNING TO ADVECT IN FROM THE WEST DURING THE LATE AFTERNOON HOURS. BECAUSE THIS WARMER AIRMASS WILL LIKELY NOT REACH THE LOCAL AREA UNTIL LATE IN THE DAY. WITH HIGHS CLIMBING INTO THE LOWER AND MIDDLE 40S IN MOST LOCATIONS. THE EC/GFS/GEM ENSEMBLE MEANS ALL MAINTAIN A WRN USA RIDGE/ERN USA TROF. THE STRONGEST OF THESE TROFS WILL SLIDE BY SAT NIGHT. ASSOCIATED WITH A 160 KT JET STREAK CURVING AROUND THE TOP TO THE WRN RIDGE. MAINTAINED CONTINUITY WITH PREVIOUS SHIFT ON THE SLIGHT CHANCE OF SPRINKLES WITH PASSAGE OF THE SFC TROF. SUN: EVEN BETTER S AND W OF THE TRI-CITIES WHERE TEMPS WILL CLIMB EVEN WARMER. EITHER WAY TEMPS WILL BE WARMER THAN NORMAL.
AT THE TIME OF THIS WRITING, AN UPPER LOW CONTINUED TO MATURE AS IT WAS APPROACHING WESTERN ARIZONA.
141 PM CST THU FEB 19 2015 AT H5 LARGE CLOSED LOW OVER THE NORTHEAST CONUS SENDING FRIGID ARCTIC ACROSS THE EASTERN CONUS WITH RECORD LOWS ACROSS THE EASTERN SEABOARD. RIDGING INTO THE WESTERN CONUS WITH THE HIGH PLAINS JUST ON THE EDGE OF THE COLDEST AIR. SHOWERS TO DEVELOP ALONG THE HIGHER TERRAIN OF THE PANHANDLE IN UPGLIDE AND ISENTROPIC LIFT.
THEN LATE TONIGHT AS THE LOW STARTS DROPPING SOUTHEAST INTO EASTERN NORTH DAKOTA. WITH AN INVERTED TROUGH INTO NORTHWEST NORTH DAKOTA.
TEMPS RUNNING ROUGHLY 2-4 DEGREES WARMER THAN THIS TIME YESTERDAY AT MANY PLACES AND BUMPED UP MAX TEMP GRID ACCORDINGLY. WATER VAPOR IMAGERY AND H5 ANALYSIS SHOW THE UPSTREAM RIDGE BEING TOPPED OFF BY PACIFIC ENERGY. THE MODELS ARE IN AGREEMENT THAT A COLD FRONT WILL BE FORCED INTO THE NORTHWEST CWA BY LATE MORNING. PTYPE COULD BE AN ISSUE IN THE AFTERNOON AS GUIDANCE SUGGEST TEMPERATURES STAYING IN THE LOW TO MID 40S. IF HEAVIER PRECIPITATION DEVELOPS TEMPERATURES COULD QUICKLY DROP AND BRING SNOW TO THE LOWER ELEVATIONS. THEN TOWARD THE ELKS BY LATE AFTERNOON AS THE ASCENT SWINGS THROUGH NORTHERN COLORADO ON THE WAY TO THE HIGH PLAINS.
312 PM CST THU FEB 19 2015 THE BIGGEST ISSUE TONIGHT AND INTO FRIDAY MORNING WILL BE THE POTENTIAL FOR FREEZING DRIZZLE AND POSSIBLY FREEZING LIGHT RAIN ACROSS PORTIONS OF EASTERN OKLAHOMA AND WESTERN ARKANSAS AS MOISTURE SURGES NORTH IN ADVANCE OF AN APPROACHING STORM SYSTEM. THE POTENTIAL FOR FREEZING DRIZZLE/FREEZING LIGHT RAIN WILL EXIST MAINLY NORTH OF A FORT SMITH TO TULSA LINE. THERE IS ALSO THE POTENTIAL THAT THE PRECIPITATION WILL NOT BEGIN BEFORE THE TEMPERATURE RISES ABOVE FREEZING. THE COLD FRONT IS EXPECTED TO COME THROUGH EASTERN OKLAHOMA AND WESTERN MUCH FASTER THAT WHAT WAS THOUGHT YESTERDAY.
Over the next 24 hours, a large scale trough develops over the Rockies as the long wave ridge amplifies off of the west coast.
1142 AM CST THU FEB 19 2015 FAST NORTHWESTERLY FLOW ALOFT WILL CONTINUE OVER THE REGION IN BETWEEN A DEEP TROUGH TO OUR EAST AND RIDGING TO OUR WEST. MOISTURE WILL BE THE LIMITING FACTOR EARLY TODAY WITH DRY HIGH PRESSURE OVERHEAD.
1141 AM CST Thu Feb 19 2015 /18Z TAFS/ Strong lee trough will continue the next 24 hours, bringing up IFR to MVFR ceilings tonight, from south to north. With persistent lee trough and developing 35 KT 850 MB winds by 6Z, winds are not expected to decouple this evening. Lee trough will develop today, resulting in a tightening pressure gradient and a corresponding increase in surface winds.
AS LOW LEVEL MOISTURE RETURNS THIS EVENING IN RESPONSE TO LOW PRESSURE OUT WEST. AS A STRONG COLD FRONT ADVANCES SOUTHEAST ACROSS THE REGION.
The persistent ridge of high pressure over the Western US has been flattened slightly as a weak system moves through the Pacific Northwest. Temperatures over the mountains and along the peripheries of the Central Valley will warm up nicely today with continued high pressure. The lower elevations of the Valley will likely be much slower to warm today with dreary conditions likely persisting into the afternoon. The aforementioned Pacific Northwest trough is expected to elongate and deepen over the Great Basin over the course of the next several days.
THE NAM WAS FOLLOWED FOR FRIDAY'S HIGHS, YIELDING TEMPERATURES RIGHT AROUND 50 DEGREES, TO MUCH WARMER UPPER 60S IN THE EXTREME SOUTHWEST. MEDIUM RANGE MODELS INDICATE THE FIRST IMPULSE EJECTING OUT OF THE ROCKIES INTO THE HIGH PLAINS FRIDAY NIGHT HELPING TO USHER A COLD FRONT SOUTHWARD ACROSS WESTERN KANSAS OVERNIGHT.
346 PM CST THU FEB 19 2015 HIGH PRESSURE SYSTEM THAT HAS BEEN RIDGING DOWN INTO THE FORECAST AREA TODAY IS BEGINNING TO MOVE OFF TO THE EAST WITH LIGHT RETURN FLOW OFF THE GULF SHOWING UP OVER THE FAR SOUTHWEST ZONES. THE HIGH WILL CONTINUE TO MOVE OFF TO THE EAST WITH LOW PRESSURE DEVELOPING OVER WEST TEXAS.
AND DELAYING THE ONSET OF MEASURABLE PRECIPITATION FOR MOST AREAS UNTIL TEMPERATURES HAVE A CHANCE TO GET UP ABOVE FREEZING MID-MORNING FRIDAY. BUT MODEL SOUNDINGS SHOW QUITE THE DRY LAYER IN THE LOW LEVELS. SURFACE TEMPERATURES ARE EXPECTED TO BE (AND REMAIN) ABOVE FREEZING IN MOST AREAS. IT IS THIS AREA THAT I HAVE THE MOST CONCERN ABOUT THE MODELS IMPROPERLY HANDLING THE LOW LEVEL MOISTURE PROFILE FRIDAY NIGHT. AND THE LOW LEVEL OF CONFIDENCE IN WINTER PRECIP CAUSING ANY IMPACT AT ALL. IF THERE IS SOME FREEZING RAIN IN THOSE NORTHEAST COUNTIES FRIDAY NIGHT.
ONCE THIS TROF PASSES. THERE WILL BE A SUBSTANTIAL DECREASE IN CLOUDS ONCE THIS TROF PASSES.
HIGH PRESSURE WILL BE MOVING OFF TO THE EAST TONIGHT WITH MOISTURE INCREASING ACROSS THE REGION OUT AHEAD OF THE NEXT WEATHER SYSTEM. THIS LOOKS TO START OUT AS A RAIN AND FREEZING RAIN MIX DURING THE AM HOURS ACROSS THE NORTHWEST DELTA. HIGHS TOMORROW WILL RANGE FROM THE LOWER 40S NE TO THE LOWER 60S SW. RAIN WILL CONTINUE FRIDAY NIGHT AS A WARM FRONT PUSHES INTO THE CWA. FREEZING PRECIP WILL NOT BE A CONCERN FRIDAY NIGHT AS WARMER AIR CONTINUES TO MOVE IN.
A COLD FRONT WILL PUSH INTO THE PANHANDLES LATE THIS AFTERNOON AND INTO THE EARLY EVENING WHICH WILL VEER THE WINDS TO THE NORTH BUT ALSO REDUCE SPEEDS TO LESS THAN 10 KNOTS. THE MAIN AVIATION CONCERN WILL BE THE PASSAGE OF A WEAK COLD FRONT THIS EVENING.
357 PM CST THU FEB 19 2015 (Tonight and Friday) A lee trough and a developing 30-40 Knot 850 MB low level jet this evening will keep winds from decoupling.
EAST TO NORTHEAST FLOW AROUND THE HIGH WILL KEEP A DRY AIR MASS IN PLACE. SFC OBS INDICATE THAT THE EXPECTED COLD FRONT HAS INDEED PASSED THE AREA WITH NERLY WINDS NOW PREVAILING AT ALL TAF SITES. COLD FRONT IS BEGINNING TO MOVE THROUGH SOUTHERN LOUISIANA.
/ISSUED 625 AM MST Thu Feb 19 2015/ FXUS65 KTFX 191325 AFDTFX NATIONAL WEATHER SERVICE GREAT FALLS MT 625 AM MST Thu Feb 19 2015 The high wind warning has been cancelled for the Rocky Mountain Front as wind speeds have dropped well below criteria for a high wind warning.
330 PM CST THU FEB 19 2015 WARM FRONT IS PRESSING EASTWARD AT THIS TIME. NOT SURE WHY TEMPERATURES WOULD PLUMMET ALL THAT MUCH WITH THIS KIND OF SOUTHERLY FLOW AND THE WARM FRONT NOT STALLING. THEREFORE TRENDED TOWARD THE WARMER READINGS WHICH WERE RAW ECMWF VALUES BLENDED WITH MOS CONSENSUS. NOW ONTO THE WARM FRONTAL SNOW. BONE DRY AIR IN THE LOW LEVELS. BEHIND THE WARM FRONT.
353 PM EST THU FEB 19 2015 WIDESPREAD LIGHT SNOWS AND SNOW SHOWERS WILL CONTINUE TONIGHT AS LOW PRESSURE OVER EASTERN MAINE MOVES INTO THE CANADIAN MARITIMES BY FRIDAY MORNING.
417 PM EST THU FEB 19 2015 COLD AND WINDY DAY IN STORE FOR THE REGION AS AN AREA HIGH PRESSURE IS OVER US. ESP AS LL THERMAL TROUGH IS SLOW TO BREAK DOWN TIED TO BACKING LL FLW AFT MIDNIGHT. HWVR BASED ON POSITION OF ARCTIC RIDGE AND VARIABLE BUT DEEMED SUFFICIENTLY DEEP SNOWPACK ACRS THE AREA. RECORDS ARE AS FOLLOWS: KSBN KFWA 19TH -11/1936 -7/1978 20TH -6/1929 -7/1904 ARCTIC HIGH SHIFTS OFF THE MID ATL COAST ON FRI AS H5 HGTS FLATTEN CONSIDERABLY UPSTREAM OF VIGOROUS CYCLONE LIFTING NWD UP ACRS THE CANADIAN MARITIMES.
THE LOW CLOUDS AND FOG COULD LINGER INTO EARLY AFTERNOON. OFFSHORE HIGH PRESSURE AND A THERMAL TROUGH NEAR THE COAST WILL BOTH STRENGTHEN OVER THE NEXT SEVERAL DAYS.
WITH THE CENTER OF THE HIGH PRESSURE AREA RIDGING SOUTHWARD AT THIS TIME. HAVE LEFT OUT OF THE KMSL TAF GIVEN THE LOW PROBABILITY ATTM.
128 PM EST THU FEB 19 2015 A COLD PRESSURE RIDGE WILL EXTEND THROUGH THE FORECAST AREA TONIGHT AND FRIDAY.
1259 PM EST THU FEB 19 2015 HIGH PRESSURE AND A VERY COLD AIRMASS WILL REMAIN OVER THE REGION TODAY THROUGH FRIDAY.
EXPECT LOWER VFR/MVFR CEILINGS TO RETURN DURING THE LATTER HALF OF THE CURRENT TAF PERIOD AS THE LOWER LAYERS OF THE ATMS CONTINUE TO MOISTEN. EXPECT VFR CONDITIONS TO PREVAIL TODAY THROUGH TONIGHT AS THE 500MB TROUGH ACROSS THE EASTERN UNITED STATES COAST CONTINUES TO PROVIDE SUBSIDENCE ACROSS THE RIO GRANDE VALLEY. 500MB RIDGE ACROSS THE WESTERN UNITED STATES AND A 500MB TROUGH ACROSS THE EASTERN U. THE NORTHWEST FLOW ALOFT WILL CONTINUE ACROSS SOUTH TEXAS TONIGHT INTO FRIDAY EVEN AS A 500MB TROUGH BEGINS TO DEVELOP ACROSS THE WESTERN U. AS THE UPPER RIDGE ACROSS THE WESTERN U. MOVES EASTWARD AND LOW PRESSURE DEVELOPS ACROSS NORTHWEST TX. THE PRESSURE GRADIENT WILL INCREASE ACROSS THE LOWER TX COAST FRIDAY AS A RESULT. EXPECT WARMER TEMPERATURES TODAY AND FRIDAY WITH BREEZY CONDITIONS AND A SLIGHT CHANCE OF SHOWERS ACROSS THE COASTAL WATERS FRIDAY.
ONE MORE WARM DAY CAN BE EXPECTED UNTIL FRIDAY NIGHT COLD FRONT BRINGS MUCH COOLER AIR INTO THE PANHANDLES.
SOME FINE MIST MIGHT ALSO BE POSSIBLE WITH THE LOW CLOUD COVER. EXPECT SEASONAL TEMPERATURES THE NEXT COUPLE DAYS WITH WARMER THAN NORMAL MIN TEMPS TONIGHT. UPPER TROUGHING OVER THE EASTERN US PULLS FARTHER EAST TO LEAVE A MORE ZONAL PATTERN OVER TX.
148 PM PST THU FEB 19 2015 HIGH PRESSURE WILL REMAIN ALONG THE WEST COAST THROUGH THE END OF THE WEEK.
AND A VERY STRONG COLD FRONT. SOUTHERLY FLOW WILL CONTINUE TO ESTABLISH ITSELF ACROSS THE AREA TONIGHT IN RESPONSE TO THIS TROUGH. SOUTHERLY WINDS WILL PROMOTE LOW TEMPERATURES WARMER THAN WE/VE SEEN OVER THE PAST FEW MORNINGS /TEMPERATURES BOTTOMING OUT IN THE UPPER 40S TO MID 50S/.
MOISTURE ADVECTION IN THE LOWER LEVELS WILL COMMENCE TONIGHT AS A TROUGH AXIS DEEPENS ON THE LEE SIDE OF THE ROCKIES. DEEP SOUTHERLY FLOW WILL PROVIDE ENOUGH LIFT TO SATURATE THE LOW-LEVEL COLUMN AFTER MIDNIGHT TONIGHT.
High pressure ridge moving over the region tonight.
SOME DRIZZLE OR FREEZING DRIZZLE WILL BE POSSIBLE BY LATE FRIDAY MORNING. LOCATIONS IN WEST CENTRAL / NORTHWEST AR MAY SEE SOME SUB-FREEZING TEMPS & LIGHT FREEZING RAIN OR DRIZZLE INTO FRIDAY MORNING.
354 PM EST THU FEB 19 2015 WIDESPREAD LIGHT SNOWS AND SNOW SHOWERS WILL CONTINUE TONIGHT AS LOW PRESSURE OVER EASTERN MAINE MOVES INTO THE CANADIAN MARITIMES BY FRIDAY MORNING.
1105 AM EST THU FEB 19 2015 A PRESSURE RIDGE BEHIND THE FRONT WILL EXTEND THROUGH THE FORECAST AREA FRIDAY.
Keep in mind that widespread MVFR/IFR ceilings and visibilities in snow could develop from KGTF /ISSUED 625 AM MST Thu Feb 19 2015/ FXUS65 KTFX 191325 AFDTFX NATIONAL WEATHER SERVICE GREAT FALLS MT 625 AM MST Thu Feb 19 2015 The high wind warning has been cancelled for the Rocky Mountain Front as wind speeds have dropped well below criteria for a high wind warning.
WITH THE CENTER OF THE HIGH PRESSURE AREA RIDGING SOUTHWARD AT THIS TIME.
THE PRECIP SHOULD TAPER OFF BY MID MORNING AND WE WILL SEE DECREASING CLOUDS MOVE SOUTH AS ARCTIC HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS. THE HIGH WILL CONTINUE INTO TONIGHT AS THE MAIN UPPER TROUGH CONTINUES TO DIG SOUTHEASTWARD. WINDS WILL DECREASE AS THE CENTER OF THE HIGH MOVES DOWN INTO WESTERN ND. THE COLD HIGH PRESSURE WILL REMAIN THROUGH THURSDAY WITH HIGHS JUST ABOVE ZERO.
315 AM PST WED FEB 25 2015 A FAST MOVING DRY COLD FRONT WILL PASS THROUGH THE SIERRA AND NORTHWEST NEVADA LATE TODAY, THOUGH WILL HAVE LITTLE IMPACT. A DEVELOPING STORM SYSTEM IN THE NORTHEAST PACIFIC IS LIKELY TO BRING RAIN, SNOW, AND COOLER TEMPERATURES TO THE REGION BY THE END OF THE WEEK AND START OF THE WEEKEND.
HAVE RAISED FREEZING RAIN ACCUMULATIONS ACROSS THE WARNING AREA GIVEN THAT IT IS THE PREDOMINANT PRECIP TYPE RIGHT NOW ALONG AND NORTH OF THE CORRIDOR. AS THE UPPER LEVEL TROUGH ACCELERATES INTO OUR REGION LATER THIS AFTN. UNDER THE CENTER AND NORTH OF THE TROUGH.
A cold front with northerly winds will begin moving through the area around 04z. A strong upper low moving across the area this morning will quickly pass to the east putting the region on the east edge of a West Coast ridge and a and on the west side of a broad trough over the center of the country.
THIS WILL ALLOW FOR A COLD FRONT TO MOVE INTO CENTRAL FLORIDA OVERNIGHT AND THERE COULD BE ANOTHER ROUND OF FOG ACROSS SOUTH FLORIDA. LIGHT SW WINDS THIS MORNING BECOME S-SE AND BECOME GUSTY AT TIMES THIS AFTERNOON AS LOW PRESSURE IN THE GULF MOVES EAST AND INCREASES THE PRESSURE GRADIENT ACROSS SOUTH FLORIDA. COLD FRONT WILL REACH NORTH- CENTRAL FLORIDA BY EARLY THURSDAY, WITH ASSOCIATED PRECIPITATION LIKELY REMAINING NORTH OF LAKE OKEECHOBEE THROUGH 12Z THURSDAY. DEEP MOIST SOUTHERLY FLOW WILL INCREASE LATE TODAY AS AN AREA OF LOW PRESSURE ACROSS THE NORTHERN GULF OF MEXICO PUSHES TO THE NORTHEAST AND DEEPENS. AS THE LOW CONTINUES TO PUSH NORTHEAST AND TOWARD THE CAROLINA COAST. IT WILL DRAG A COLD FRONT THROUGH THE AREA DURING THE DAY THURSDAY.
724 AM EST WED FEB 25 2015 A LOW PRESSURE AREA OVER QUEBEC WILL PASS NORTH OF THE REGION TODAY. THIS LOW PRESSURE AREA WILL BRING ANOTHER ARCTIC COLD FRONT THROUGH THE REGION TODAY ALONG WITH A CHANCE OF SNOW SHOWERS. A RIDGE OF HIGH PRESSURE WILL BUILD EAST FROM THE GREAT LAKES ON THURSDAY AND WILL REMAIN OVER THE NORTH COUNTRY THROUGH THIS WEEKEND. THIS IS THE ARCTIC COLD FRONT APPROACHING THE REGION AT THIS TIME. SOUTHERLY WINDS AND CLOUD COVER HELPING TO KEEP TEMPERATURES MUCH WARMER THAN THEY WERE 24 HOURS AGO. EXPECTING A CHANCE OF SNOW SHOWERS WITH THE COLD FRONTAL PASSAGE.