Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/25/14
AREA FORECAST DISCUSSION
NWS PUEBLO CO
534 PM MST MON FEB 24 2014
.UPDATE...
ISSUED AT 520 PM MST MON FEB 24 2014
UPDATED FORECAST TO END RED FLAG WARNING AND BLOWING DUST
ADVISORIES. ALSO BUMPED UP TIMING OF FRONT INTO SOUTHEAST COLORADO
TRENDING FORECAST TOWARDS THE FASTER HRRR. GUSTS IN NORTHEAST
COLORADO ARE AROUND 30-40KTS BEHIND THE FRONT...AND TEMPERATURES ARE IN
THE UPPER 20S. HRRR BRINGS THE FRONT THROUGH MOST OF SOUTHEAST
COLORADO BY 03Z...AND SHOULD BRING A STARK CHANGE ONCE IT BLOWS
THROUGH. GRIDS ATTEMPT TO FINE TUNE THESE DETAILS BETTER. -KT
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 252 PM MST MON FEB 24 2014
CURRENTLY...WESTERLY FLOW HAS ALLOWED FOR STRONG MIXING THIS
AFTERNOON ACROSS THE I-25 CORRIDOR. THIS HAS HELP TEMPERATURES RISE
INTO THE UPPER 60S TO LOWER 70S. WINDS ARE GUSTY...WITH GUSTS 25 TO
35 KTS SO FAR...ESPECIALLY OVER THE SOUTHERN I-25 CORRIDOR.
HUMIDITY VALUES ARE ALSO RUNNING AROUND 10 PERCENT AND EXTREME FIRE
DANGER IS PRESENT. HAVE NOT SEEN ANY REPORTS OF BLOWING DUST YET
BUT THERE WILL LIKELY BE SOME IN WIND PRONE AREAS...FROM PUEBLO TO
TRINIDAD. FURTHER EAST...CLOUDS AND LIGHT EASTERLY FLOW HAVE HELD
TEMPERATURES DOWN THIS AFTERNOON...WITH MID 40S FOR LA JUNTA AND
LAMAR. HOW WARM IT GETS DOWN THE FAR EASTERN ARKANSAS RIVER BASIN
WILL DEPEND ON CLEARING AND HOW FAR WESTERLIES PUSH THE WARMER AIR.
TONIGHT...A STRONG COLD FRONT CURRENTLY ENTERING NORTHERN COLORADO
WILL PROGRESS QUICKLY SOUTH ACROSS THE EASTERN PLAINS THIS EVENING.
EXPECT BREEZY NORTH WINDS BEHIND THE FRONT WHICH WILL ADVECT COLD
AIR INTO THE REGION. EXPECT TEMPERATURES TO FALL RAPIDLY BEHIND THE
FRONT. ONCE THE FRONT PASSES...EXPECT LOW LEVEL FLOW TO SWING
SOUTHEASTERLY. THIS WILL ALLOW LOW STRATUS AND FOG TO DEVELOP OVER
PORTIONS OF THE EASTERN PLAINS LATE TONIGHT INTO TUESDAY MORNING.
WHILE THE AIR MASS IS SHALLOW...PATCHY AREAS OF FREEZING DRIZZLE CAN
NOT BE RULED OUT AS WELL. ANY FOG OR FREEZING DRIZZLE COULD HAMPER
DRIVING CONDITIONS ACROSS EL PASO COUNTY...AND DOWN THE ARKANSAS
RIVER BASIN FOR TUESDAY MORNINGS COMMUTE. LIGHT SNOW IS EXPECTED TO
MOVE INTO THE CENTRAL MOUNTAINS AFTER MIDNIGHT WITH A QUICK INCH
POSSIBLE BY TUESDAY MORNING.
TUESDAY...THE MAIN FORECAST CHALLENGE WILL BE TEMPERATURES. HAVE
TRENDED AFTERNOON HIGHS DOWN WITH MOST AREAS STRUGGLING TO MAKE IT
OUT OF THE 30S ACROSS THE EASTERN PLAINS. THE EXCEPTION WILL LIKELY
BE THE LEE SLOPES OF THE EASTERN MOUNTAINS...WHERE SOME AFTERNOON
MIXING AND CLEARING OF CLOUD COVER WILL HELP BOOST HIGHS INTO THE
40S. IF CLOUDS CAN CLEAR...AND WE SEE BETTER AFTERNOON MIXING THAN
IS ANTICIPATED...AREAS OVER THE PLAINS COULD BE A BIT WARMER. BY
THE LATE AFTERNOON...ANOTHER COLD FRONT WILL PUSH SOUTH INTO EASTERN
COLORADO. ALL MODELS DEVELOP LIGHT PRECIPITATION ACROSS THE PALMER
DIVIDE BY MID AFTERNOON...AND SPREAD IT SOUTH INTO THE HIGHWAY 50
CORRIDOR BY SUNSET. AREAS OVER TELLER COUNTY WILL LIKELY SEE AN
INCH OR SO OF SNOW DURING THE LATE AFTERNOON. SNOW WILL BE LIGHT
OVER THE CENTRAL MOUNTAINS DURING THE MORNING HOURS AND PICK UP IN
INTENSITY DURING THE AFTERNOON. AN ADDITIONAL 1 TO 3 INCHES ARE
POSSIBLE BY TUESDAY EVENING FOR THE CENTRAL MOUNTAINS. MOZLEY
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 252 PM MST MON FEB 24 2014
...WEEKEND STORM STILL LOOKS GOOD...ESPECIALLY FOR THE CONTDVD...
TUESDAY NIGHT...
DISTURBANCE WILL BE MOVING ACROSS THE AREA AND WILL LIKELY BRING
SOME LIGHT SNOW TO AREAS GENERALLY NORTH OF A LINE FROM SALIDA TO
PUEBLO TO LAMAR. BEST CHANCE OF PRECIP WILL BE OVER THE CENTRAL MTNS
AND THE PIKES PEAK REGION. SNOWFALL AMOUNTS OVER THE C MTNS WILL BE
2-4" WITH 1-3" OVER TELLER COUNTY AND POSSIBLY AN INCH OR TWO OVER N
EL PASO COUNTY. THERE COULD BE SOME COMMUTING ISSUES IN EL PASO
COUNTY LATE TOMORROW AFTERNOON. THIS WILL BE A QUICK MOVING EVENT
AND BY SUNRISE WED WE SHOULD BE SEEING CLEARING SKIES OVER MOST OF
THE REGION.
WED-WED NITE...
AREA WILL BE IN-BETWEEN SYSTEMS. SNOW SHOWERS WILL BE POSSIBLE OVER
THE CONTDVD WITH OTHER AREAS DRY. TEMPS WED WILL BE
SEASONABLE...U40S/L50S PLAINS.
THU INTO EARLY FRI...
FIRST PACIFIC SYSTEM MOVES ACROSS REGION. SKIES WILL CLOUD UP DURING
THE DAY THU WITH PRECIP INCREASING OVER THE MTNS DURING THE DAY.
SNOW WILL PICK UP IN INTENSITY LATE THU OVER THE CONTDVD AND
COULD BE LOCALLY HEAVY AT TIMES THU NITE BEFORE DECREASING EARLY
FRIDAY. SOME PRECIP WILL BE POSSIBLE OVER THE PLAINS...WITH THE
BEST CHANCE OVER EL PASO AND THE FAR EASTERN PLAINS...ESPECIALLY
KIOWA COUNTY. TEMPS COULD BE TRICKY THURSDAY AS A BOUNDARY WILL
LIKELY LIE ACROSS THE PLAINS EXTENDING FROM ROUGHLY KIM TO
PUEBLO...AREAS E OF THIS LINE COULD SEE A CLOUDY COOL DAY WHILE
AREAS WEST OF THIS LINE MAY BE QUITE WARM...WINDY AND DRY...WITH FIRE
WX CONCERNS POSSIBLE ESPECIALLY DOWN ON THE RATON MESA.
LATE FRIDAY INTO EARLY SUNDAY...
A MORE SIGNIFICANT PACIFIC SYSTEM WILL MOVE ACROSS THE REGION. THIS
SYSTEM HAS THE POTENTIAL TO BRING HEAVY SNOWS TO THE CONTDVD
REGION...AND LATEST MODEL RUNS ARE STARTING TO SHOW MORE SIGNIF
QPF. HPC SHOWING 1-3" LIQUID OVER THE MTNS DURING THIS TIME. A
BETTER CHANCE OF PRECIP WILL OCCUR ON THE PLAINS SATURDAY/SAT NITE
AS MUCH COLDER AIR WILL BE MOVING INTO THE REGION AS THE PACIFIC
STORM MOVES ACROSS. THIS COMBO OF COLDER UPSLOPE AND FORCING ALOFT
SHOULD ALLOW FOR SOME SNOW ON THE PLAINS. BEST CHANCE WILL BE
NORTH OF HIWAY 50. I DO ANTICIPATE TRAVEL INTO THE MTNS THIS
WEEKEND WILL BE A BIT TEDIOUS...BUT THERE IS NOT MUCH WIND WITH
THIS SYSTEM SO BLOWING SNOW WILL BE LESS OF A CONCERN.
IT SHOULD BE NOTED THAT THE GFS IS MORE INTENSE WITH THIS SYSTEM
THEN THE LESS AMPLIFIED EC MODEL...HOWEVER BOTH MODELS HAVE GOOD QPF
FOR THE MTNS.
LOOKING A BIT BEYOND...GFS SHOWS ANOTHER SHARP TROUGH COMING ACROSS
LATE MONDAY INTO EARLY TUESDAY WHILE EC SHOWS A MUCH WEAKER SYSTEM.
LONG RANGE DISCUSSIONS WERE LEANING MORE TOWARDS THE EC GUIDANCE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 252 PM MST MON FEB 24 2014
KALS...VFR CONDITIONS THROUGH THE NEXT 24 HOURS WITH DIURNALLY
DRIVEN WINDS.
KCOS...WINDS HAVE BEEN SLOW TO INCREASE THIS AFTERNOON AND HAVE
STARTED TO GUST FROM THE WEST TO 25 KTS. THIS WILL CONTINUE THROUGH
THIS AFTERNOON. A COLD FRONT WILL DROP SOUTH ACROSS THE TERMINAL
THIS EVENING WITH A NORTHERLY WIND SHIFT THROUGH THE EVENING. EXPECT
FLOW TO TURN SOUTHEASTERLY BY 09Z TONIGHT WHICH WILL USHER IN LOW
STRATUS AND FOG PRODUCING MVFR TO IFR CONDITIONS INTO TUESDAY MID
MORNING. A SECONDARY COLD FRONT WILL MOVE SOUTH ACROSS THE TERMINAL
BY TUESDAY AFTERNOON. SNOW WILL LIKELY DEVELOP BEHIND THE COLD
FRONT BY 00Z/WED WITH REDUCED CIGS AND VIS.
KPUB...WEST WINDS WITH GUSTS TO 25 KTS WILL CONTINUE THIS AFTERNOON.
AREAS OF BLOWING DUST WILL BE POSSIBLE THIS AFTERNOON IN AREAS
AROUND THE TERMINAL. A COLD FRONT WILL MOVE SOUTH ACROSS THE
TERMINAL THIS EVENING WITH A NORTHERLY WIND SHIFT. FLOW WILL SHIFT
EASTERLY BY 09Z WITH LOW STRATUS AND FOG DEVELOPING THROUGH TUESDAY
MORNING PRODUCING MVFR TO IFR CONDITIONS. CONDITIONS SHOULD IMPROVE
BY MID MORNING TUESDAY WITH A RETURN TO VFR. A SECOND COLD FRONT
WILL MOVE ACROSS THE AREA BY TUESDAY EVENING WITH LOWERED CIGS AND A
SMALL CHANCE FOR SNOW TUESDAY NIGHT. MOZLEY
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KT
SHORT TERM...MOZLEY
LONG TERM...HODANISH
AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS PUEBLO CO
323 PM MST SUN FEB 23 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 300 PM MST SUN FEB 23 2014
CURRENTLY...LOW STRATUS HAS SLOWLY ERODED TO LEAVE SUNNY SKIES
ACROSS SOUTHERN COLORADO THIS AFTERNOON. TEMPERATURES HAVE BEEN
HIGHLY DEPENDENT ON WIND...WHERE ITS WESTERLY...TEMPERATURES HAVE
WARMED INTO THE 40S TO LOW 50S...WHERE ITS EASTERLY THEY HAVE
REMAINED IN THE 30S. EXPECT A COUPLE OF MORE DEGREES OF WARMING FOR
MOST AREAS...WITH THE EXCEPTION OF THE I-25 CORRIDOR...WHERE RAPID
WARM UPS ARE POSSIBLE AS WESTERLIES TRY AND MAKE IT EAST.
TONIGHT...BROAD NORTHWEST FLOW WILL ENCOMPASS THE REGION THROUGH THE
SHORT TERM. THE MAIN QUESTION WILL BE THE DEGREE OF LOW STRATUS
SLOSHING BACK WEST ACROSS THE PLAINS TONIGHT. FOLLOWED THE HRRR AND
LOCAL WRF...WHICH KEEPS STRATUS OUT ALONG THE KANSAS BORDER WITH
LITTLE PROGRESSION WEST. THE CAVEAT WILL BE HOW QUICKLY LEE TROUGH
DEVELOPS AND LOW LEVEL WESTERLY FLOW. BOTH THE HRRR AND WRF HAVE
WESTERLIES PICKING UP BY MIDNIGHT AND SHIFTING CLEAR OUT TO THE
KANSAS BORDER BY 10-11Z. THIS SHOULD ALLOW FOR RAPID CLEARING OF
ANY STRATUS OUT EAST BY DAYBREAK. IF THE LEE TROUGHING IS SLOWER TO
DEVELOP THAN MODELS PROJECT...STRATUS COULD MAKE IT MUCH FURTHER
WEST AND IMPACT THE WARMING EXPECTED BY SUNRISE. OVERNIGHT LOWS
WILL GENERALLY BE IN THE 20S ACROSS THE REGION...WITH SOME LOWER 30S
FOR THE BANANA BELT.
MONDAY...BROAD NORTHWEST FLOW ALOFT CONTINUES WITH DRY CONDITIONS
FOR SOUTHERN COLORADO. THE MAIN CONCERNS WILL BE BREEZY AFTERNOON
WINDS LEADING TO AREAS OF BLOWING DUST AND ELEVATED FIRE WEATHER
CONCERNS. STRONG MIXING BY THE AFTERNOON WILL BRING WIDESPREAD WIND
GUSTS TO NEAR 30 MPH ALONG THE LEE SLOPES...EAST INTO THE I-25
CORRIDOR. THESE GUSTY WINDS WILL LIKELY PRODUCE AREAS OF BLOWING
DUST...ESPECIALLY IN DUST PRONE AREAS SOUTH AND NORTH OF
PUEBLO...CREATING HAZARDOUS DRIVING CONDITIONS. IN
ADDITION...HUMIDITY VALUES ARE EXPECTED TO FALL INTO THE 10-15
PERCENT RANGE...AND WHEN COMBINED WITH THE GUSTY WINDS...WILL
PRODUCE DANGEROUS FIRE WEATHER CONDITIONS...PARTICULARLY ALONG THE
SOUTHERN I-25 CORRIDOR. EXPECT THE MIXING TO HELP BOOST
TEMPERATURES FOR TOMORROW WITH HIGHS TOPPING OUT IN THE LOWER TO MID
60S FOR THE LOWER ELEVATIONS. MOZLEY
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 300 PM MST SUN FEB 23 2014
...ACTIVE WX PATTERN AS PACIFIC STORMS BEGIN TO AFFECT THE REGION...
MON NITE-INTO WED...
CANADIAN HIGH PRESSURE WILL AFFECT THE HI PLAINS DURING THIS TIME
PERIOD WITH PERSISTENT UPSLOPE FLOW OVER THE PLAINS. A SHORTWAVE
ALOFT IN THE NW FLOW WILL MOVE ACROSS TUE
AFTERNOON/EVENING...AND THIS DISTURBANCE WILL BRING A CHANCE OF
RAIN AND SNOW TO THE PLAINS. FOR NOW PAINTED POPS IN THE HIGH
ISOLATED/LOW END SCATTERED CATEGORY. WITH THE MOIST UPSLOPE FLOW
EXPECT AN EXTENDED PERIOD OF CLOUDINESS TO AFFECT THE PLAINS. BY
LATER WED...SFC FLOW WILL TRANSITION TO SOUTHERLY AND THIS
SHOULD DECREASE THE CLOUDINESS. THE ONLY POSSIBLE EXCEPTION WILL
BE THE COS AREA WHERE THE SOUTHERLY FLOW MAY KEEP THE CLOUDS IN
PLACE UNTIL LATE MORNING. PERSISTENT SNOW SHOWERS WILL BE POSSIBLE
ACROSS THE C MTNS FROM MON NITE-EARLY WED
THURSDAY...
THE FIRST IN A SERIES OF PACIFIC WEATHER SYSTEMS WILL BEGIN TO
AFFECT THE REGION. VALLEY RAIN SHOWERS AND SNOW IN THE MTNS WILL
AFFECT THE CONTDVD BY THU LATE MORNING OR EARLY AFTERNOON AND
INCREASE THU AFTERNOON AND NITE. GIVEN THE QUALITY
MOISTURE...INSTABILITY...UPSLOPE FLOW AND FORCING...WE WILL LIKELY
SEE SNOWFALL AMOUNTS REQUIRING HILITES (WINTER STORM WARNING?) FOR
THE CONTDVD.
LATE THU NITE INTO FRIDAY...
UPSLOPE FLOW DEVELOPS ON THE PLAINS AND WE WILL SEE COOLER
WX...CLOUDINESS AND A CHANCE OF SOME PRECIP RETURNING TO THE LOWER
ELEVATIONS.
WEEKEND...
FRI NITE INTO EARLY SATURDAY A BRIEF RIDGE WILL BUILD ALOFT
DECREASING THE CLOUDS AND ENDING THE PRECIP...BUT ANOTHER STRONGER
PACIFIC STORM WILL BE QUICKLY MOVING IN. AS THIS PACIFIC STORM MOVES
TOWARDS THE CONTDVD...ANOTHER REINFORCING CANADIAN HIGH PRESSURE
SYSTEM WILL BE MOVING DOWN THE PLAINS...AND WILL BE AFFECTING THE
LOWER ELEVATIONS BY LATER SATURDAY MORNING. SNOW WILL DEVELOP ONCE
AGAIN OVER THE MTNS DURING THE DAY SATURDAY WITH PRECIP DEVELOPING
ON THE PLAINS LATE SAT AFTERNOON/EVENING. GUIDANCE AT THIS TIME IS
FAVORING THE PALMER DVD BUT I WOULD NOT BE TOO SURPRISED IF ALL OF
THE PLAINS RECEIVE SOME PRECIP SAT NITE INTO SUNDAY AS THE MIDLVL
TROUGH MOVES OVER THE REGION. OVERALL METEOROLOGICAL CONDITIONS
FOR THIS WEEKENDS STORM LOOK PRETTY GOOD GIVEN THAT THE COLD AIR
WILL ALREADY BE IN PLACE AS THE DYNAMICS MOVE OVER THE REGION. FOR
NOW I GOT TEMPS IN THE 30S AND 40S FOR THE WEEKEND WITH SLIGHT/LOW
END SCT POPS FOR THE AREA. I WOULD NOT BE TOO SURPRISED IF THE
TEMPS ARE LOWERED AND THE POPS ARE INCREASED AS WE GET CLOSER TO
THIS EVENT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 300 PM MST SUN FEB 23 2014
VFR CONDITIONS THROUGH THE NEXT 24 HOURS AT ALL THREE TERMINALS.
WESTERLY WINDS ARE FORECAST TO DEVELOP AT KPUB WITH GUSTS TO 30 KTS
POSSIBLE MONDAY AFTERNOON. MOZLEY
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY AFTERNOON
FOR COZ228>230.
&&
$$
SHORT TERM...MOZLEY
LONG TERM...HODANISH
AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1033 AM MST SUN FEB 23 2014
.UPDATE...
&&
.SHORT TERM...LOW CLOUDS AND AREAS OF FOG RELUCTANT TO DISSIPATE OVER
THE SOUTH PLATTE BASIN...INCLUDING NORTHERN AND CENTRAL PORTIONS
OF THE I-25 CORRIDOR. ALTHOUGH VSBYS ARE BEGINNING TO IMPROVE SUCH
AS THE CHANGE AT DIA FROM 1/4 MILE TO 2 MILES IN THE PAST FEW
MINS.SLOWEST TO CLEAR OUT WILL BE AREAS ACROSS THE NORTHEAST
CORNER WHERE NEW BLANKET OF SNOW WILL CONTINUE TO CHILL THE BNDRY
LAYER AND WITH THE HIGHER CLOUD DECK GENERATED BY THE NEARBY JET
WILL CONTINUE TO BLOCK OUT SUNSHINE. MEANWHILE...DRAMATIC
CLEARING WAS UNDERWAY OVER AND NEAR THE HIGHER TERRAIN TO THE
SOUTH AND SOUTHEAST OF DENVER WITH DRIER AIR MIXING DOWN OFF THE
FOOTHILLS AND ALOFT. AT PRESENT RATE SHOULD SEE CLEARING SPREADING
NORTHWARD OVER THE REMAINDER OF THE DENVER METRO AREA OVER THE
NEXT COUPLE OF HOURS..AND THE FOG DISSIPATING IN MOST AREAS BY
NOON OR SHORTLY THEREAFTER. BECAUSE OF THE SLOW CLEARING...FELT IT
NECESSARY TO LOWER HIGH TEMPERATURES ON THE PLAINS BY AT LEAST A
FEW DEGS UP AGAINST THE FOOTHILLS...AND AS MUCH AS 5-10 DEG F
FARTHER OUT ON THE PLAINS IN THE CLOUDY AREAS. FURTHERMORE...HAVE
OBSERVED A MODEST JUMP IN WIND SPEEDS AT FRONT RANGE RECORDING
PAST COUPLE OF HOURS. RUC AND NAM ALSO SHOW THIS TREND. SO NUDGED
UP SPEEDS IN THIS AREA FOR THE REMAINDER OF THE DAY. COULD SEE
GUSTSAROUND 50 MPH IN PARTS OF THE FOOTHILLS... WITH POSSIBLE
GUSTS AROUND 65 MPH ON THE HIGHER PEAKS.
TONIGHT...MODELS SHOW A RETURN OF BOUNDARY LAYER MOISTURE UP THE
SOUTH PLATTE RIVER BASIN WITH EAST-SOUTHEAST LOW-LEVEL FLOW.
RH FIELDS INDICATE NEAR SATURATED AIR IN THE AREA OVERNIGHT. SO
INTRODUCED AREAS OF FOG AND LOW CLOUDS FOR AREAS ROUGHLY NORTH AND
EAST OF THE DENVER AREA FOR MOST OF TONIGHT. DOWNSLOPE FLOW OFF
THE FOOTHILLS SHOULD KEEP THE LOW CLOUDS AND FOG OUT OF THE
DENVER METRO AREA...EXCEPT PERHAPS ITS FAR NORTHERN SUBURBS AND
COMMUNITIES.
.AVIATION...ILS-IFR CONDITIONS DUE TO LOW CIGS AND FOG AT DENVER
AREA AIRPORTS EXPECTED THROUGH 1830Z...THEN GRADUAL IMPROVEMENT
FROM THE SOUTH AND WEST AS DRIER AIR MOVES DOWN OF THE FOOTHILLS
AND PALMER DIVIDE. COULD SEE VFR CONDITIONS AT BJC AND APA BY 19Z
OR 20Z. WHEREAS...DIA MAY CONTINUE TO SEE IFR CONDITIONS THROUGH
19Z...THEN A GRADUAL LIFT IN CIGS AND VSBYS THEREAFTER WITH LIGHT
SFC WINDS GRADUALLY BECOMING EAST-SOUTHEAST IN DIRECTION. SHOULD
SEE CLEARING OVERNIGHT...HOWEVER...PATCHY LOW CLOUDS AND FOG MAY
FORM AGAIN IN THE DIA AREA AFTER 04Z TONIGHT...WITH VSBYS
POSSIBLY AS LOW AS 3 MILES IN PATCHY FOG.
&&
.PREV DISCUSSION... /ISSUED 417 AM MST SUN FEB 23 2014/
SHORT TERM...SNOW IS LIFTING TO THE ENE ABOUT AS EXPECTED WITH
DRIER AIR ALOFT MOVING IN. STILL DECENT SNOW RIGHT ALONG THE
NORTHERN BORDER AND OVER THE NORTHERN MOUNTAINS FOR A FEW MORE
HOURS. ADVISORIES ARE SET TO EXPIRE AT 6 AM AND THAT LOOKS ABOUT
RIGHT. MEANWHILE THERE IS A SOLID STRATUS DECK ON THE PLAINS AND
WITH SOUTHEAST WINDS DEVELOPING EXPECT THAT THIS WILL HANG ON
LONGER THAN WE HAD PREVIOUSLY FORECAST. COULD BE A RAGGED EDGE TO
THIS CLOUD DECK OVER THE DENVER AREA COMPLICATING THE FORECAST. WE
HAVE HAD SOME PLACES WHERE IT HAS CLEARED AND THE STRATUS FILLED
IN AT A LOWER HEIGHT...AND STILL A FEW PATCHES OF LOWER CLOUDS
BENEATH IT...NOTABLY FROM GREELEY INTO DIA. NOT SO SURE OF THE
DENSE FOG AT THE AIRPORT...BUT IN GENERAL EXPECTING PERSISTENCE
FOR MUCH OF THE MORNING WITH A SLOW BURN OFF THE REST OF THE DAY.
WE ARE ALREADY SHOWING QUITE A TEMPERATURE GRADIENT FROM DENVER
TOWARD THE NORTHEAST CORNER OF THE STATE...WHICH WILL BE ENHANCED
BY BOTH THE TIMING OF THE CLEARING AND THE NEW SNOW COVER. IF THE
CLEARING IS MUCH SLOWER WE COULD BE TOO WARM IN DENVER.
FOR TONIGHT...THERE COULD BE SOME STRATUS LINGERING/REDEVELOPING
OR ADVECTING INTO THE EASTERN BORDER AREA AS SOUTHERLY WINDS
CONTINUE. OTHERWISE RELATIVELY CLEAR SKIES SHOULD ALLOW
TEMPERATURES TO DROP FAIRLY WELL DESPITE SOME WIND AND THE WARMING
ALOFT. DROPPED FORECAST LOWS JUST SLIGHTLY. ALSO ADDED SOME MORE
WIND TO THE MOUNTAINS AS THE FLOW ALOFT INCREASES AGAIN AND WE MAY
START TO GET A MOUNTAINTOP INVERSION FOR A BETTER EAST SLOPE WAVE
LATE TONIGHT.
LONG TERM...IT IS ALL WEST-NORTHWESTERLY FLOW ALOFT FOR THE
FORECAST AREA MONDAY THROUGH TUESDAY NIGHT. THE JET MAXIMUM
GENERALLY STAYS JUST NORTHEAST OF COLORADO THROUGH THE PERIOD.
THE SYNOPTIC SCALE ENERGY IS QUITE WEAK ALL FOUR PERIODS. THE
BOUNDARY LAYER FLOW IS DOWNSLOPING SOUTHWESTERLY MONDAY INTO THE
AFTERNOON. A COLD FRONT COMES IN MONDAY AFTERNOON...WITH UPSLOPE
BEHIND IT FOR THE PLAINS AND FOOTHILLS THROUGH MUCH OF MONDAY
NIGHT. ANOTHER COLD FRONT MOVES IN TUESDAY MORNING WITH PRETTY
DECENT UPSLOPE TUESDAY AFTERNOON INTO THE EARLY EVENING. NORMAL
DRAINAGE WIND PATTERNS SEEM REASONABLE LATER TUESDAY NIGHT. FOR
MOISTURE...THERE ISN`T A LOT AROUND ON MONDAY EARLY...BUT IT
STARTS TO INCREASE IN THE AFTERNOON. IT GETS DEEPER OVER THE
MOUNTAINS MONDAY NIGHT...AND THERE IS SOME IN THE LOWER LEVELS
OVER THE PLAINS. MOISTURE INCREASES ON TUESDAY AND IT IS PRETTY
DEEP OVER ALL THE CWA TUESDAY AFTERNOON THROUGH TUESDAY MIDNIGHT
..THEN IT DECREASES. THE QPF FIELDS HAVE A TAD OF MEASURABLE
SNOWFALL OVER THE NORTHERN CWA MONDAY LATE DAY INTO THE EVENING.
BETTER MEASURABLE SNOW COVERING MUCH OF THE CWA IS PROGGED ON
TUESDAY FROM 18Z INTO 06Z TUESDAY EVENING. MODELS ARE ALL OVER THE
PLACE WHEN COMPARED TO ONE ANOTHER. FOR POPS...WILL UP THEM ON
TUESDAY FOR MOST OF THE CWA. THERE WILL BE NONE FOR MONDAY...AND A
TAD MONDAY NIGHT. FOR TEMPERATURES...WILL BE A BIT WARMER THAN
TODAY. TUESDAY LOOKS TO BE CONSIDERABLY COLDER. THE NAM MOS HAS A
HIGH OF 55 F FOR DIA TUESDAY...THE ECMWF MOS HAS 24 F. FOR THE
LATER DAYS...WEDNESDAY THROUGH SATURDAY...MODELS SHOW WEAKENING
NORTHWESTERLY FLOW ALOFT WEDNESDAY...WITH A DYING UPPER RIDGE
MOVING IN WEDNESDAY NIGHT. THERE IS A WEAK UPPER TROUGH FOR LATE
THURSDAY. STRONGER WEST-NORTHWESTERLY FLOW ALOFT IS IN PLACE
FRIDAY...THEN SOUTHWESTERLY FLOW ALOFT ON SATURDAY WITH A
DEVELOPING TROUGH TO THE WEST. CONFIDENCE IS A BIT SHAKY.
AVIATION...EXPECT STRATUS TO LINGER IN THE DENVER AREA THROUGH
16Z-18Z...WITH SLOWER CLEARING ON THE EASTERN PLAINS. SUSPECT THE
DENSE FOG AT KDEN AT THIS TIME IS NOT WIDESPREAD...BUT WITH LIGHT
NE WINDS AND POSSIBLY CLOUDS ABOVE IT THERE COULD BE LIFR
CONDITIONS THERE AS LATE AS 16Z. VFR CONDITIONS SHOULD DEVELOP BY
18Z AND CONTINUE THROUGH TONIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....RJK
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS ALBANY NY
951 PM EST MON FEB 24 2014
.SYNOPSIS...
AN ARCTIC AIR MASS WILL BE IN PLACE THIS WEEK WITH BELOW NORMAL
TEMPERATURES. A SERIES OF DISTURBANCES ASSOCIATED WITH AN UPPER
LEVEL LOW WILL PRODUCE SCATTERED SNOW SHOWERS AND FLURRIES INTO THE
MID WEEK. A CLIPPER LOW ON WEDNESDAY WILL PRODUCE MORE WIDESPREAD
SNOW SHOWERS...AS IT PASSES ACROSS THE SOUTHERN QUEBEC AND NORTHERN
NEW YORK BORDER...WITH A REINFORCING SHOT OF ARCTIC AIR.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 950 PM EST...LAKE EFFECT SNOW SHOWERS HAVE BEEN SLOWLY
ORGANIZING SOMEWHAT BETTER OVER THE PAST FEW HOURS OVER PORTIONS
OF OSWEGO/ONEIDA COUNTIES...BUT STILL ARE MAINLY FRAGMENTED BANDS
FARTHER EAST ACROSS THE SOUTHWEST ADIRONDACKS AND NORTHERN MOHAWK
VALLEY. TRENDS IN THE HRRR AND HIRES WRF INDICATE THESE FRAGMENTED
BANDS WILL DRIFT SOUTH INTO SOUTHERN HERKIMER COUNTY...WHERE A
LAKE EFFECT SNOW ADVISORY REMAINS IN EFFECT. HOWEVER...THE LATEST
MODEL REFLECTIVITY TRENDS SHOW BANDS WEAKENING CONSIDERABLY AFTER
1 AM. WILL LEAVE UP ADVISORY FOR NOW...BUT WILL MONITOR TRENDS FOR
POSSIBLE CANCELLATION BEFORE 6 AM.
INVERSION HEIGHTS ARE MARGINAL UPSTREAM AT KSYR/KRME/KUCA AT 6-7
KFT AGL WITH A 280-290 DEG LOW-LEVEL TRAJ. THE INSTABILITY CLASS
IS CONDITIONAL TO MODERATE WITH NARROW FRAGMENTED LAKE BANDS
EXTENDING DOWNSTREAM INTO THE WESTERN MOHAWK VALLEY. WILL
CONTINUE TO MENTION SLIGHT TO LOW CHC POPS MAINLY WEST OF THE
HUDSON RIVER VALLEY...EXCEPT HIGH CHANCE TO LIKELY POPS FOR THE
WESTERN MOHAWK VALLEY AND A PORTION OF THE SOUTHWEST ADIRONDACKS
WHERE LAKE EFFECT ACTIVITY WILL BE MORE PRONOUNCED.
H850 TEMPS WILL BE IN THE -17C TO -20C RANGE WITH THE COLD
ADVECTION IN THE WAKE OF THE SFC TROUGH. EXPECT LOWS TO BE IN THE
UPPER SINGLE DIGITS AND TEENS FROM THE CAPITAL DISTRICT SOUTH AND
EAST...WITH SINGLE DIGITS TO A FEW BELOW ZERO READINGS /SRN DACKS/ OVER
THE NRN TIER. BRISK W/NW WINDS WILL GENERATE WIND CHILLS 10 TO 15
BELOW ZERO OVER THE SRN DACKS...AND GENERALLY 5 BELOW TO 5 ABOVE
IN MOST OTHER LOCATIONS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
TUESDAY...ANY ORGANIZED LAKE EFFECT ACTIVITY DIMINISHES DUE TO THE
LOWERING INVERSION. HOWEVER...LAKE MOISTURE WILL STILL BE
UTILIZED...AS A WEAK MID LEVEL DISTURBANCE MAY FOCUS ISOLATED TO
SCATTERED SNOW SHOWERS AGAIN DURING DURING THE MORNING INTO THE
AFTERNOON...WITH THE BETTER CHANCE OF SNOWFALL IN THE AFTERNOON
ALONG THE WRN SPINE OF THE WRN DACKS...SRN GREENS...NRN-CNTRL
TACONICS AND BERKSHIRES. THE WESTERLY UPSLOPE SNOW SHOWERS AND
FLURRIES MAY PRODUCE LIGHT SNOW AMOUNTS OF A COATING TO AN INCH OR
TWO. H850 TEMPS WILL BE RUNNING 1 TO 2 STANDARD DEVIATIONS BELOW
NORMAL ACCORDING TO THE LATEST GEFS. TEMPS WILL STILL RUN ABOUT 10
DEGREES OR SO BELOW NORMAL. OUR FORECAST FAVORS THE COLD NAM MOS
MAX TEMPS WITH TEENS OVER THE SRN DACKS. LOWER TO M20S OVER THE
REST OF THE FCST AREA...EXCEPT U20S OVER THE MID HUDSON
VALLEY...SRN TACONICS...AND NW CT.
TUE NIGHT...A CLIPPER LOW APPROACHES FROM THE NRN GREAT LAKES
REGION...AND SE ONTARIO. THIS CLIPPER WILL TAP SOME LAKE EFFECT
MOISTURE...AS THE FLOW BACKS TO SOUTHWEST. THERE IS SOME SYNOPTIC
LIFT WITH THIS SYSTEM. OROGRAPHIC AND LOW-LEVEL CONVERGENCE MAY
PROMOTE A PERIOD OF LIGHT SNOW ESPECIALLY NORTH AND WEST OF THE
CAPITAL REGION. A BURST OF LAKE EFFECT OR LAKE ENHANCED SNOWFALL
MAY OCCUR OVER THE WRN DACKS/WRN MOHAWK VALLEY AROUND MIDNIGHT AND
THEREAFTER. 1-4 INCHES OF SNOWFALL MAY BE POSSIBLE...ESPECIALLY
OVER THE WRN DACKS BY WED MORNING. WITH THE WEAK THERMAL
ADVECTION...SLIGHT OR LOW CHANCES OF SNOW SHOWERS SPREAD EASTWARD
ACROSS THE FCST AREA AFTER MIDNIGHT. LOWS WILL RANGE FROM THE
SINGLE DIGITS OVER THE NW PORTION OF THE FCST AREA TO TEENS FROM
THE MOHAWK VALLEY/CAPITAL REGION SOUTH AND EAST.
WED-WED NIGHT...THE CLIPPER MOVES N/NE OF NRN NY OVER SRN QUEBEC
BY NOON. ANOTHER LOW PRESSURE SYSTEM FORMS WELL OFF THE MID
ATLANTIC COAST. A PERIOD OF SNOW SHOWERS OR LIGHT SNOW WILL IMPACT
THE REGION DURING THE MORNING INTO THE EARLY PM AHEAD OF THE
ARCTIC FRONT. CHC POPS WERE USED FOR THE ENTIRE AREA. SNOW ACCUMS
OF A COATING TO AN INCH WILL BE POSSIBLE. ARCTIC AIR POURS BACK
INTO THE REGION WITH H850 TEMPS FALLING TO -19C TO -23C OVER THE
FCST AREA...AND THE GEFS INDICATE THESE VALUES WILL BE 2 TO 3
STANDARD DEVIATIONS BELOW NORMAL. THE STRONG COLD ADVECTION SWEEPS
THROUGH BEFORE NIGHTFALL. AFTER HIGHS IN THE TEENS AND 20S WITH
BLUSTERY CONDITIONS...LOWS WILL BE ZERO TO 5 BELOW OVER THE SRN
DACKS AND PARTS OF THE LAKE GEORGE REGION....AND SINGLE DIGITS
ELSEWHERE. UPSLOPE AND LAKE EFFECT SNOW SHOWERS WILL CONTINUE IN
THE AFTERNOON...AND THEN TAPER SNOW SHOWERS NORTH AND WEST OF THE
TRI CITIES WITH ANOTHER DISTURBANCE APPROACHING FROM THE UPPER
GREAT LAKES REGION. WIND CHILLS VALUES MAY NOT HIT ADVISORY LEVELS
WED NIGHT DUE TO A WEAKENING WIND FIELD...BUT MAY HIT ADVISORY
LEVELS OVER SOME OF THE MTN ZONES THU NIGHT/FRI MORNING.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
A SERIES OF EMBEDDED SHORTWAVES WILL MOVE ABOUT THE BASE OF A LARGE
UPPER LEVEL TROUGH THAT WILL PROVIDE CHANCES OF SOME PRECIPITATION
THROUGHOUT THE EXTENDED PERIOD. THE UPPER LEVEL FLOW PATTERN WILL
BEGIN TO SLOWLY TRANSITION INTO A ZONAL PATTERN WITH COLD AIR STILL
IN PLACE AS WE GO THE THE END OF THE EXTENDED PERIOD.
THURSDAY INTO FRIDAY...COLD NORTHWESTERLY FLOW WITH BELOW AVERAGE
TEMPERATURES WITH T850 BETWEEN -20C TO -24C AND T925 TEMPS BETWEEN
-16C AND -20C WILL BE LOCKED INTO THE REGION. A NEGATIVE TILTED
SHORTWAVE TROUGH WITHIN THE UPPER LEVEL FLOW WITH THE AXIS OVER THE
NY/CANADA BORDER WILL PROVIDE THE CHANCE OF SNOW SHOWERS ESPECIALLY
AREAS NORTH AND WEST OF THE IMMEDIATE CAPITAL REGION NEAR THE UPPER
LEVEL TROUGH AS WE GO THURSDAY NIGHT INTO FRIDAY MORNING. A STEEP
GRADIENT IN ISOBARS WILL ALSO PRODUCE GUSTY NORTHWEST WINDS
WITH GUSTS NEAR 30 MPH POSSIBLE ESPECIALLY IN THE HIGHEST TERRAIN.
TEMPERATURES ON THURSDAY WILL RANGE FROM THE LOWER 20S TO UPPER 20S
WHICH WILL FALL TO LOWER TEENS IN THE HIGH TERRAIN TO NEAR 20 IN
VALLEY LOCATIONS ON FRIDAY. LOW TEMPERATURES ON THURSDAY WILL BE
VERY COLD WITH VALUES RANGING FROM 10 BELOW TO NEAR ZERO IN THE HIGH
TERRAIN TO AROUND ZERO TO 5 ABOVE FOR THE VALLEY AREAS.
FRIDAY NIGHT THROUGH MONDAY...COLD AIR FROM CANADA WITH
NORTHWESTERLY WINDS WILL CONTINUE WITH SERIES OF UPPER LEVEL TROUGHS
CONTINUING TO MOVE WEST TO EAST ACROSS OUR AREA WITH AREAS OF WEAK
HIGH PRESSURE IN BETWEEN THE PASSING DISTURBANCES AS THE UPPER LEVEL
WAVE OSCILLATES AROUND THE LARGE UPPER LEVEL LOW IN NORTHERN QUEBEC.
THE NEXT CHANCE OF SNOW SHOWERS ACCORDING TO THE LATEST 12Z MODELS
AND NUMERICAL GUIDANCE WILL BE DURING THE DAY ON SATURDAY AS ANOTHER
WAVE OF LOW PRESSURE MOVES RIGHT OVER OUR REGION ACCORDING TO THE
LATEST TRENDS. CHANCE OF SNOW SHOWERS WILL BE IN THE FORECAST AT
THIS TIME AS THE TRACK AND INTENSITY AGREEMENT BETWEEN THE MODELS
SHOW LOW CONFIDENCE AT THIS TIME. A SURFACE HIGH PRESSURE WILL WORK
INTO THE AREA ON SUNDAY GIVING TRANQUIL WEATHER CONDITIONS. AS WE GO
INTO MONDAY...THE MODELS DO DIFFER IN OUR NEXT WEATHER SYSTEM WITH
ITS TRACK AND INTENSITY. THIS WILL HAVE TO BE MONITORED WITH FUTURE
UPDATES TO THE FORECAST. HIGH TEMPERATURES FROM SATURDAY INTO MONDAY
WILL REMAIN BELOW AVERAGE WITH TEMPERATURES RANGING FROM THE MID
TEENS TO MID 20S. LOW TEMPERATURES WILL ALSO BE VERY COLD FOR THIS
TIME OF YEAR WITH TEMPERATURE 10 BELOW ZERO TO NEAR ZERO FOR THE
LAKE GEORGE SARATOGA REGION POINTS NORTH AND WEST AND ALSO IN THE
HIGH TERRAIN OF NEW ENGLAND AND WITH LOW TEMPERATURES OF 0 TO 5 IN
THE IMMEDIATE CAPITAL REGION AND VALLEY LOCATIONS.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
MAINLY VFR CONDITIONS WITH CIGS AROUND 3500-5000 FEET ARE
EXPECTED AT THE TERMINALS THROUGH THE 24 HOUR PERIOD ENDING 00Z
WEDNESDAY. THE ONLY EXCEPTION WILL BE A LOW PROBABILITY FOR A
PASSING SNOW SHOWER OR TWO. SNOW SHOWERS HAVE BEEN DIMINISHING IN
COVERAGE THIS EVENING WITH LOSS OF DAYTIME HEATING.
HOWEVER...THERE IS STILL A CHANCE FOR A FEW LAKE ENHANCED SNOW
SHOWERS TONIGHT INTO EARLY TUESDAY MORNING. WILL MENTION VCSH AT
THE ALB/KPSF/KGFL TERMINALS TO ACCOUNT FOR THIS CHANCE. ANY SNOW
SHOWER COULD BRIEFLY RESULT IN MVFR/IFR CONDITIONS...BUT
PROBABILITY OF OCCURRENCE IS TOO LOW TO MENTION EXPLICITLY IN
TAFS.
WEST-NORTHWEST WINDS WILL INITIALLY BE AROUND 10-15 KT WITH GUSTS
TO 25 KT ESPECIALLY AT KALB/KPSF...WITH WIND SPEEDS DECREASING TO
AROUND 5-10 KT AFTER MIDNIGHT. WIND SPEEDS WILL INCREASE AGAIN BY
MID MORNING TUESDAY TO AROUND 10-15 KT WITH SOME GUSTS NEAR 20 KT.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. WINDY. CHANCE OF SHSN.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF SHSN.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
&&
.HYDROLOGY...
AN ARCTIC AIR MASS WILL REMAIN ACROSS THE HYDRO SERVICE AREA FOR
THE ENTIRE WEEK WHICH WILL ALLOW ICE TO REFORM...THICKEN...AND
STRENGTHEN ON AREA RIVERS AND LAKES THROUGH THE WEEK. LIGHT
PRECIPITATION IS EXPECTED DURING THE WEEK...AND ANY THAT DOES
OCCUR WILL BE IN THE FORM OF SNOW SHOWERS OR LIGHT SNOW. NO HYDRO
IMPACTS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5 DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST TUESDAY FOR NYZ038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...JPV/WASULA
SHORT TERM...WASULA
LONG TERM...LFM
AVIATION...JPV
HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
650 PM EST MON FEB 24 2014
.SYNOPSIS...
AN ARCTIC AIR MASS WILL BE IN PLACE THIS WEEK WITH BELOW NORMAL
TEMPERATURES. A SERIES OF DISTURBANCES ASSOCIATED WITH AN UPPER
LEVEL LOW WILL PRODUCE SCATTERED SNOW SHOWERS AND FLURRIES INTO THE
MID WEEK. A CLIPPER LOW ON WEDNESDAY WILL PRODUCE MORE WIDESPREAD
SNOW SHOWERS...AS IT PASSES ACROSS THE SOUTHERN QUEBEC AND NORTHERN
NEW YORK BORDER...WITH A REINFORCING SHOT OF ARCTIC AIR.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 650 PM EST...NOT MANY CHANGES NEEDED WITH THIS FORECAST
UPDATE. CELLULAR SNOW SHOWER ACTIVITY HAS BEEN DECREASING IN
COVERAGE AND INTENSITY THIS EVENING AFTER SUNSET. THIS TREND
SHOULD CONTINUE OVERNIGHT..EXCEPT FOR THE CONTINUED THREAT FOR
LAKE EFFECT SNOW SHOWERS TO IMPACT AREAS FROM THE SOUTHWEST
ADIRONDACKS SOUTHWARD TO THE MOHAWK VALLEY. THE MOST CONCENTRATED
ACTIVITY IS EXPECTED TO BE ACROSS SOUTHERN HERKIMER COUNTY...WHERE
A LAKE EFFECT SNOW ADVISORY REMAINS IN EFFECT. WE DID LOWER
EXPECTED SNOWFALL TOTALS SLIGHTLY TO 3 TO 6 INCHES...SINCE
ACTIVITY HAS BEEN RATHER DISORGANIZED THUS FAR.
INVERSION HEIGHTS ARE MARGINAL UPSTREAM AT KSYR/KRME/KUCA AT 6-7
KFT AGL WITH A 280-290 DEG LOW-LEVEL TRAJ. THE INSTABILITY CLASS
IS CONDITIONAL TO MODERATE WITH THE POSSIBILITY OF NARROW
FRAGMENTED LAKE BANDS EXTENDING DOWNSTREAM INTO SRN HERKIMER
SUPPORTED BY THE LOCAL HIRESWRF COLUMNAR REF PRODUCT BTWN 00Z-03Z.
THE LATEST HRRR 3-KM REF PRODUCT ALSO KEYS INTO THIS AREA.
GENERALLY...SLIGHT TO LOW CHC POPS HAVE BEEN FORECAST TONIGHT WEST
OF THE HUDSON RIVER VALLEY...EXCEPT HIGH CHANCE TO LIKELY POPS FOR
THE WESTERN MOHAWK VALLEY AND A PORTION OF THE SOUTHWEST
ADIRONDACKS WHERE LAKE EFFECT ACTIVITY WILL BE MORE PRONOUNCED.
H850 TEMPS WILL BE IN THE -17C TO -20C RANGE WITH THE COLD
ADVECTION IN THE WAKE OF THE SFC TROUGH. EXPECT LOWS TO BE IN THE
UPPER SINGLE DIGITS AND TEENS FROM THE CAPITAL DISTRICT SOUTH AND
EAST...WITH SINGLE DIGITS TO A FEW BELOW ZERO READINGS /SRN DACKS/ OVER
THE NRN TIER. BRISK W/NW WINDS WILL GENERATE WIND CHILLS 10 TO 15
BELOW ZERO OVER THE SRN DACKS...AND GENERALLY 5 BELOW TO 5 ABOVE
IN MOST OTHER LOCATIONS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
TUESDAY...ANY ORGANIZED LAKE EFFECT ACTIVITY DIMINISHES DUE TO THE
LOWERING INVERSION. HOWEVER...LAKE MOISTURE WILL STILL BE
UTILIZED...AS A WEAK MID LEVEL DISTURBANCE MAY FOCUS ISOLATED TO
SCATTERED SNOW SHOWERS AGAIN DURING DURING THE MORNING INTO THE
AFTERNOON...WITH THE BETTER CHANCE OF SNOWFALL IN THE AFTERNOON
ALONG THE WRN SPINE OF THE WRN DACKS...SRN GREENS...NRN-CNTRL
TACONICS AND BERKSHIRES. THE WESTERLY UPSLOPE SNOW SHOWERS AND
FLURRIES MAY PRODUCE LIGHT SNOW AMOUNTS OF A COATING TO AN INCH OR
TWO. H850 TEMPS WILL BE RUNNING 1 TO 2 STANDARD DEVIATIONS BELOW
NORMAL ACCORDING TO THE LATEST GEFS. TEMPS WILL STILL RUN ABOUT 10
DEGREES OR SO BELOW NORMAL. OUR FORECAST FAVORS THE COLD NAM MOS
MAX TEMPS WITH TEENS OVER THE SRN DACKS. LOWER TO M20S OVER THE
REST OF THE FCST AREA...EXCEPT U20S OVER THE MID HUDSON
VALLEY...SRN TACONICS...AND NW CT.
TUE NIGHT...A CLIPPER LOW APPROACHES FROM THE NRN GREAT LAKES
REGION...AND SE ONTARIO. THIS CLIPPER WILL TAP SOME LAKE EFFECT
MOISTURE...AS THE FLOW BACKS TO SOUTHWEST. THERE IS SOME SYNOPTIC
LIFT WITH THIS SYSTEM. OROGRAPHIC AND LOW-LEVEL CONVERGENCE MAY
PROMOTE A PERIOD OF LIGHT SNOW ESPECIALLY NORTH AND WEST OF THE
CAPITAL REGION. A BURST OF LAKE EFFECT OR LAKE ENHANCED SNOWFALL
MAY OCCUR OVER THE WRN DACKS/WRN MOHAWK VALLEY AROUND MIDNIGHT AND
THEREAFTER. 1-4 INCHES OF SNOWFALL MAY BE POSSIBLE...ESPECIALLY
OVER THE WRN DACKS BY WED MORNING. WITH THE WEAK THERMAL
ADVECTION...SLIGHT OR LOW CHANCES OF SNOW SHOWERS SPREAD EASTWARD
ACROSS THE FCST AREA AFTER MIDNIGHT. LOWS WILL RANGE FROM THE
SINGLE DIGITS OVER THE NW PORTION OF THE FCST AREA TO TEENS FROM
THE MOHAWK VALLEY/CAPITAL REGION SOUTH AND EAST.
WED-WED NIGHT...THE CLIPPER MOVES N/NE OF NRN NY OVER SRN QUEBEC
BY NOON. ANOTHER LOW PRESSURE SYSTEM FORMS WELL OFF THE MID
ATLANTIC COAST. A PERIOD OF SNOW SHOWERS OR LIGHT SNOW WILL IMPACT
THE REGION DURING THE MORNING INTO THE EARLY PM AHEAD OF THE
ARCTIC FRONT. CHC POPS WERE USED FOR THE ENTIRE AREA. SNOW ACCUMS
OF A COATING TO AN INCH WILL BE POSSIBLE. ARCTIC AIR POURS BACK
INTO THE REGION WITH H850 TEMPS FALLING TO -19C TO -23C OVER THE
FCST AREA...AND THE GEFS INDICATE THESE VALUES WILL BE 2 TO 3
STANDARD DEVIATIONS BELOW NORMAL. THE STRONG COLD ADVECTION SWEEPS
THROUGH BEFORE NIGHTFALL. AFTER HIGHS IN THE TEENS AND 20S WITH
BLUSTERY CONDITIONS...LOWS WILL BE ZERO TO 5 BELOW OVER THE SRN
DACKS AND PARTS OF THE LAKE GEORGE REGION....AND SINGLE DIGITS
ELSEWHERE. UPSLOPE AND LAKE EFFECT SNOW SHOWERS WILL CONTINUE IN
THE AFTERNOON...AND THEN TAPER SNOW SHOWERS NORTH AND WEST OF THE
TRI CITIES WITH ANOTHER DISTURBANCE APPROACHING FROM THE UPPER
GREAT LAKES REGION. WIND CHILLS VALUES MAY NOT HIT ADVISORY LEVELS
WED NIGHT DUE TO A WEAKENING WIND FIELD...BUT MAY HIT ADVISORY
LEVELS OVER SOME OF THE MTN ZONES THU NIGHT/FRI MORNING.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
A SERIES OF EMBEDDED SHORTWAVES WILL MOVE ABOUT THE BASE OF A LARGE
UPPER LEVEL TROUGH THAT WILL PROVIDE CHANCES OF SOME PRECIPITATION
THROUGHOUT THE EXTENDED PERIOD. THE UPPER LEVEL FLOW PATTERN WILL
BEGIN TO SLOWLY TRANSITION INTO A ZONAL PATTERN WITH COLD AIR STILL
IN PLACE AS WE GO THE THE END OF THE EXTENDED PERIOD.
THURSDAY INTO FRIDAY...COLD NORTHWESTERLY FLOW WITH BELOW AVERAGE
TEMPERATURES WITH T850 BETWEEN -20C TO -24C AND T925 TEMPS BETWEEN
-16C AND -20C WILL BE LOCKED INTO THE REGION. A NEGATIVE TILTED
SHORTWAVE TROUGH WITHIN THE UPPER LEVEL FLOW WITH THE AXIS OVER THE
NY/CANADA BORDER WILL PROVIDE THE CHANCE OF SNOW SHOWERS ESPECIALLY
AREAS NORTH AND WEST OF THE IMMEDIATE CAPITAL REGION NEAR THE UPPER
LEVEL TROUGH AS WE GO THURSDAY NIGHT INTO FRIDAY MORNING. A STEEP
GRADIENT IN ISOBARS WILL ALSO PRODUCE GUSTY NORTHWEST WINDS
WITH GUSTS NEAR 30 MPH POSSIBLE ESPECIALLY IN THE HIGHEST TERRAIN.
TEMPERATURES ON THURSDAY WILL RANGE FROM THE LOWER 20S TO UPPER 20S
WHICH WILL FALL TO LOWER TEENS IN THE HIGH TERRAIN TO NEAR 20 IN
VALLEY LOCATIONS ON FRIDAY. LOW TEMPERATURES ON THURSDAY WILL BE
VERY COLD WITH VALUES RANGING FROM 10 BELOW TO NEAR ZERO IN THE HIGH
TERRAIN TO AROUND ZERO TO 5 ABOVE FOR THE VALLEY AREAS.
FRIDAY NIGHT THROUGH MONDAY...COLD AIR FROM CANADA WITH
NORTHWESTERLY WINDS WILL CONTINUE WITH SERIES OF UPPER LEVEL TROUGHS
CONTINUING TO MOVE WEST TO EAST ACROSS OUR AREA WITH AREAS OF WEAK
HIGH PRESSURE IN BETWEEN THE PASSING DISTURBANCES AS THE UPPER LEVEL
WAVE OSCILLATES AROUND THE LARGE UPPER LEVEL LOW IN NORTHERN QUEBEC.
THE NEXT CHANCE OF SNOW SHOWERS ACCORDING TO THE LATEST 12Z MODELS
AND NUMERICAL GUIDANCE WILL BE DURING THE DAY ON SATURDAY AS ANOTHER
WAVE OF LOW PRESSURE MOVES RIGHT OVER OUR REGION ACCORDING TO THE
LATEST TRENDS. CHANCE OF SNOW SHOWERS WILL BE IN THE FORECAST AT
THIS TIME AS THE TRACK AND INTENSITY AGREEMENT BETWEEN THE MODELS
SHOW LOW CONFIDENCE AT THIS TIME. A SURFACE HIGH PRESSURE WILL WORK
INTO THE AREA ON SUNDAY GIVING TRANQUIL WEATHER CONDITIONS. AS WE GO
INTO MONDAY...THE MODELS DO DIFFER IN OUR NEXT WEATHER SYSTEM WITH
ITS TRACK AND INTENSITY. THIS WILL HAVE TO BE MONITORED WITH FUTURE
UPDATES TO THE FORECAST. HIGH TEMPERATURES FROM SATURDAY INTO MONDAY
WILL REMAIN BELOW AVERAGE WITH TEMPERATURES RANGING FROM THE MID
TEENS TO MID 20S. LOW TEMPERATURES WILL ALSO BE VERY COLD FOR THIS
TIME OF YEAR WITH TEMPERATURE 10 BELOW ZERO TO NEAR ZERO FOR THE
LAKE GEORGE SARATOGA REGION POINTS NORTH AND WEST AND ALSO IN THE
HIGH TERRAIN OF NEW ENGLAND AND WITH LOW TEMPERATURES OF 0 TO 5 IN
THE IMMEDIATE CAPITAL REGION AND VALLEY LOCATIONS.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
MAINLY VFR CONDITIONS WITH CIGS AROUND 3500-5000 FEET ARE
EXPECTED AT THE TERMINALS THROUGH THE 24 HOUR PERIOD ENDING 00Z
WEDNESDAY. THE ONLY EXCEPTION WILL BE A LOW PROBABILITY FOR A
PASSING SNOW SHOWER OR TWO. SNOW SHOWERS HAVE BEEN DIMINISHING IN
COVERAGE THIS EVENING WITH LOSS OF DAYTIME HEATING.
HOWEVER...THERE IS STILL A CHANCE FOR A FEW LAKE ENHANCED SNOW
SHOWERS TONIGHT INTO EARLY TUESDAY MORNING. WILL MENTION VCSH AT
THE ALB/KPSF/KGFL TERMINALS TO ACCOUNT FOR THIS CHANCE. ANY SNOW
SHOWER COULD BRIEFLY RESULT IN MVFR/IFR CONDITIONS...BUT
PROBABILITY OF OCCURRENCE IS TOO LOW TO MENTION EXPLICITLY IN
TAFS.
WEST-NORTHWEST WINDS WILL INITIALLY BE AROUND 10-15 KT WITH GUSTS
TO 25 KT ESPECIALLY AT KALB/KPSF...WITH WIND SPEEDS DECREASING TO
AROUND 5-10 KT AFTER MIDNIGHT. WIND SPEEDS WILL INCREASE AGAIN BY
MID MORNING TUESDAY TO AROUND 10-15 KT WITH SOME GUSTS NEAR 20 KT.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. WINDY. CHANCE OF SHSN.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF SHSN.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
&&
.HYDROLOGY...
AN ARCTIC AIR MASS WILL REMAIN ACROSS THE HYDRO SERVICE AREA FOR
THE ENTIRE WEEK WHICH WILL ALLOW ICE TO REFORM...THICKEN...AND
STRENGTHEN ON AREA RIVERS AND LAKES THROUGH THE WEEK. LIGHT
PRECIPITATION IS EXPECTED DURING THE WEEK...AND ANY THAT DOES
OCCUR WILL BE IN THE FORM OF SNOW SHOWERS OR LIGHT SNOW. NO HYDRO
IMPACTS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5 DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST TUESDAY FOR NYZ038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...JPV/WASULA
SHORT TERM...WASULA
LONG TERM...LFM
AVIATION...JPV
HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS MIAMI FL
858 PM EST MON FEB 24 2014
.UPDATE...
MAINLY TRANQUIL CONDITIONS PREVAIL ACROSS THE REGION THIS EVENING.
BY THE EARLY MORNING HOURS PATCHY FOG IS EXPECTED ACROSS THE
REGION AGAIN...MAINLY ACROSS THE INTERIOR REGIONS AND WEST.
NO SIGNIFICANT CHANGES WERE REQUIRED TO THE FORECAST.
60
&&
.PREV DISCUSSION... /ISSUED 628 PM EST MON FEB 24 2014/
AVIATION...
CONDITIONS SHOULD BE MOSTLY QUIET TONIGHT, WITH THE EXCEPTION OF A
STRAY, LIGHT SHOWER THAT COULD DEVELOP. OTHERWISE, VFR CONDITIONS
FOR THE EASTERN TAF SITES. THE EXCEPTION MAY BE KTMB, WHERE SOME
SOME FOG COULD DEVELOP. HOWEVER, THE IS TOO MUCH UNCERTAINTY TO
PUT A MENTION IN THE TAF AT THIS TIME. ALSO, KAPF MAY SEE SOME
FOG. THERE IS A BETTER CHANCE FOR NAPLES, THUS A MENTION OF LIGHT
FOG IN THE TAF FOR TONIGHT. TOMORROW WILL SEE A CHANCE OF SHOWERS
AND MAYBE A THUNDERSTORM FOR THE EASTERN HALF OF SOUTH FLORIDA.
FOR NOW, JUST A VCSH TO REFLECT THIS. WINDS WILL GO LIGHT AND
VARIABLE TONIGHT. THEY MAY BE DELAYED IN PICKING UP OUT OF THE
WEST TO SOUTHWEST TOMORROW BETWEEN 5 AND 10 KTS. KFLL MAYBE THE
EXCEPTION WHERE A WEAK SEA BREEZE MAY BRING THE WINDS TO A MORE
SOUTH SOUTH EASTERLY DIRECTION BY LATE MORNING OR EARLY AFTERNOON.
PREV DISCUSSION... /ISSUED 246 PM EST MON FEB 24 2014/
DISCUSSION...
A WEAK COLD FRONT CURRENTLY DRAPED ACROSS NORTHERN FLORIDA IS
EXPECTED TO SLOWLY PUSH TO THE SOUTH THROUGH THE AFTERNOON AND
EVENING. AS IT DOES...A FEW SHOWERS AND POSSIBLY AN ISOLATED
THUNDERSTORM OR TWO MAY DEVELOP ACROSS MAINLY THE EAST COASTAL AREAS
ENHANCED BY A WEAK SEA BREEZE THAT MAY DEVELOP. LATEST HRRR WINDS
DEPICT A WEAK SEA BREEZE ALONG MAINLY THE BROWARD AND PALM BEACH
COUNTY COASTS.
MODELS DEPICT THE COLD FRONT AND ACCOMPANYING DEEPER MOISTURE FIELD
TO BECOME NEARLY STATIONARY ACROSS SOUTH FLORIDA THROUGH TUESDAY
WITH RAIN CHANCES REMAINING ALONG WITH LIGHT AND VARIABLE WINDS.
KEPT SLIGHT CHANCES FOR THUNDERSTORMS TUESDAY AFTERNOON ALONG THE
NORTHERN INTERIOR AND EAST COAST AS WELL WITH THE LINGERING BOUNDARY
IN THE AREA. BY TUESDAY NIGHT INTO EARLY WEDNESDAY...THE FRONT IS
EXPECTED TO BASICALLY WASH OUT IN PLACE. FLOW WILL THEN QUICKLY
BECOME SOUTHWEST AND INCREASE LATE WEDNESDAY OUT AHEAD OF ANOTHER
COLD FRONT POSITIONED ACROSS THE NORTHERN GULF OF MEXICO. THIS FRONT
LOOKS TO BE A BIT STRONGER THAN THE LAST ONE AND SHOULD PUSH THROUGH
SOUTH FLORIDA BY EARLY THURSDAY MORNING WITH BETTER CHANCES FOR
SHOWERS. DID NOT INCLUDE A THUNDER MENTION AT THIS TIME DUE TO THE
TIMING OF THE FRONT BEING DURING THE EARLY MORNING HOURS...ACCORDING
TO THE ECMWF. THE GFS SOLUTION IS A BIT SLOWER BRINGING THE FRONT
INTO SOUTH FLORIDA LATER IN THE AFTERNOON. IF THIS SOLUTION PANS
OUT...THE COMBINATION OF FRONTAL FORCING AND DAYTIME HEATING WOULD
YIELD THUNDERSTORM DEVELOPMENT. WILL NEED TO WATCH SUBSEQUENT MODEL
RUNS CLOSELY FOR TIMING CHANGES.
SHOWERS WILL LINGER THROUGH FRIDAY BEFORE DRY WEATHER RETURNS FOR
THE WEEKEND. UPPER RIDGING WILL THEN BUILD ACROSS THE AREA FROM THE
SOUTH KEEPING TEMPERATURES ABOVE NORMAL.
MARINE...
WINDS OF 10 KNOTS OR LESS ARE EXPECTED TO CONTINUE ACROSS THE
REGIONAL WATERS WITH SEAS OF 2 FEET OR LESS. A COLD FRONT IS
FORECAST TO AFFECT THE REGIONAL WATERS EARLY THURSDAY WITH AN
INCREASE IN WINDS AND SEAS EXPECTED. HOWEVER...HAZARDOUS SEAS ARE
NOT FORECAST FOR THIS PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 67 81 63 82 / 20 30 10 20
FORT LAUDERDALE 69 82 66 82 / 20 30 10 20
MIAMI 69 83 67 83 / 20 30 10 20
NAPLES 64 79 62 80 / 10 20 - 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...60/BD
AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS MIAMI FL
628 PM EST MON FEB 24 2014
.AVIATION...
CONDITIONS SHOULD BE MOSTLY QUIET TONIGHT, WITH THE EXCEPTION OF A
STRAY, LIGHT SHOWER THAT COULD DEVELOP. OTHERWISE, VFR CONDITIONS
FOR THE EASTERN TAF SITES. THE EXCEPTION MAY BE KTMB, WHERE SOME
SOME FOG COULD DEVELOP. HOWEVER, THE IS TOO MUCH UNCERTAINTY TO
PUT A MENTION IN THE TAF AT THIS TIME. ALSO, KAPF MAY SEE SOME
FOG. THERE IS A BETTER CHANCE FOR NAPLES, THUS A MENTION OF LIGHT
FOG IN THE TAF FOR TONIGHT. TOMORROW WILL SEE A CHANCE OF SHOWERS
AND MAYBE A THUNDERSTORM FOR THE EASTERN HALF OF SOUTH FLORIDA.
FOR NOW, JUST A VCSH TO REFLECT THIS. WINDS WILL GO LIGHT AND
VARIABLE TONIGHT. THEY MAY BE DELAYED IN PICKING UP OUT OF THE
WEST TO SOUTHWEST TOMORROW BETWEEN 5 AND 10 KTS. KFLL MAYBE THE
EXCEPTION WHERE A WEAK SEA BREEZE MAY BRING THE WINDS TO A MORE
SOUTH SOUTH EASTERLY DIRECTION BY LATE MORNING OR EARLY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 246 PM EST MON FEB 24 2014/
DISCUSSION...
A WEAK COLD FRONT CURRENTLY DRAPED ACROSS NORTHERN FLORIDA IS
EXPECTED TO SLOWLY PUSH TO THE SOUTH THROUGH THE AFTERNOON AND
EVENING. AS IT DOES...A FEW SHOWERS AND POSSIBLY AN ISOLATED
THUNDERSTORM OR TWO MAY DEVELOP ACROSS MAINLY THE EAST COASTAL AREAS
ENHANCED BY A WEAK SEA BREEZE THAT MAY DEVELOP. LATEST HRRR WINDS
DEPICT A WEAK SEA BREEZE ALONG MAINLY THE BROWARD AND PALM BEACH
COUNTY COASTS.
MODELS DEPICT THE COLD FRONT AND ACCOMPANYING DEEPER MOISTURE FIELD
TO BECOME NEARLY STATIONARY ACROSS SOUTH FLORIDA THROUGH TUESDAY
WITH RAIN CHANCES REMAINING ALONG WITH LIGHT AND VARIABLE WINDS.
KEPT SLIGHT CHANCES FOR THUNDERSTORMS TUESDAY AFTERNOON ALONG THE
NORTHERN INTERIOR AND EAST COAST AS WELL WITH THE LINGERING BOUNDARY
IN THE AREA. BY TUESDAY NIGHT INTO EARLY WEDNESDAY...THE FRONT IS
EXPECTED TO BASICALLY WASH OUT IN PLACE. FLOW WILL THEN QUICKLY
BECOME SOUTHWEST AND INCREASE LATE WEDNESDAY OUT AHEAD OF ANOTHER
COLD FRONT POSITIONED ACROSS THE NORTHERN GULF OF MEXICO. THIS FRONT
LOOKS TO BE A BIT STRONGER THAN THE LAST ONE AND SHOULD PUSH THROUGH
SOUTH FLORIDA BY EARLY THURSDAY MORNING WITH BETTER CHANCES FOR
SHOWERS. DID NOT INCLUDE A THUNDER MENTION AT THIS TIME DUE TO THE
TIMING OF THE FRONT BEING DURING THE EARLY MORNING HOURS...ACCORDING
TO THE ECMWF. THE GFS SOLUTION IS A BIT SLOWER BRINGING THE FRONT
INTO SOUTH FLORIDA LATER IN THE AFTERNOON. IF THIS SOLUTION PANS
OUT...THE COMBINATION OF FRONTAL FORCING AND DAYTIME HEATING WOULD
YIELD THUNDERSTORM DEVELOPMENT. WILL NEED TO WATCH SUBSEQUENT MODEL
RUNS CLOSELY FOR TIMING CHANGES.
SHOWERS WILL LINGER THROUGH FRIDAY BEFORE DRY WEATHER RETURNS FOR
THE WEEKEND. UPPER RIDGING WILL THEN BUILD ACROSS THE AREA FROM THE
SOUTH KEEPING TEMPERATURES ABOVE NORMAL.
MARINE...
WINDS OF 10 KNOTS OR LESS ARE EXPECTED TO CONTINUE ACROSS THE
REGIONAL WATERS WITH SEAS OF 2 FEET OR LESS. A COLD FRONT IS
FORECAST TO AFFECT THE REGIONAL WATERS EARLY THURSDAY WITH AN
INCREASE IN WINDS AND SEAS EXPECTED. HOWEVER...HAZARDOUS SEAS ARE
NOT FORECAST FOR THIS PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 67 81 63 82 / 20 30 10 20
FORT LAUDERDALE 69 82 66 82 / 20 30 10 20
MIAMI 69 83 67 83 / 20 30 10 20
NAPLES 64 79 62 80 / 10 20 - 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...60/BD
AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
525 AM EST Sun Feb 23 2014
...Small Hail and Frequent Lightning Possible Along the Panhandle
Coast This Morning...
.Mesoscale Update...
A cluster of storms off of the panhandle coast will move ashore
over the next hour or so. These storms have been producing
frequent lightning, heavy rain, and may contain some small hail.
As the morning progresses, the hail threat will diminish and the
focus will shift to primarily heavy rain. See previous discussions
below.
&&
.Prev Discussion [355 AM EST]...
.Near Term [Through Today]...
The large scale pattern is highlighted by a persistent broad trough
over much of Conus. This leaves nearly zonal flow over NE Gulf
region. However a series of shortwaves will continue to move Ewd
providing increasing clouds and just enough lift that when combined
with surface features will maintain an unsettled weather pattern
today. Mid-High clouds streaming Ewd overnight assocd with lead
shortwave moving Ewd across mid-South will cross NE Gulf region
later today with the forecast area in the right entrance region of
the upper jet. At surface...in response to Ewd moving shortwave...
W-E warm front located across the Nrn Gulf waters Ewd across N/Cntrl
FL overnight will lift Nwd to coast by sunrise then to vcnty of I-10
during the day with light Sly flow in its wake. Upstream cold front
across mid-South around sunrise moves SEWD to Ern TN/N-Cntrl AL/Srn
MS by sundown with WAA and isentropic upglide spreading over our
area. Early radar showing leading edge of moisture approaching wrn
most Panhandle waters.
Patchy to areas of fog initially south of I-10 will accompany rain
and spread E/N thru the day. The combination of upper and lower
features will yield an expansive area of showers with isolated to
sct thunderstorms (highest Panhandle waters) moving SW-NE to reach
our Wrn CWA around sunrise and then progress EWD. Afternoon dew
point will rise from mid 60s coast to upper 50s Nrn tier AL/GA
counties. This depicted well in HRRR and other High Res guidance.
Limited mid-level lapse rates and a relatively cool boundary layer
should limit the potential for any strong storms. Best chance per
CAM would be Panhandle waters. However, with the upper flow parallel
to the warm boundary, main concern is training of cells is possible
with locally heavy rainfall possible especially during the aftn QPF
south of FL border exceeding 1 inch. Will go with 70-30% W-E POP
gradient in morning then 80-40% in the afternoon. Temperatures will
be tricky, depending on the eventual position of the warm front and
the coverage of the rainfall. However, expect warmest temperatures
along and south of I-10 (lower 70s), with lower to mid 60s for much
of SE AL and SW GA.
.Short Term [Tonight Through Tuesday]...
By the time the evening rolls around, the polar jet max will be
racing east and the northern stream trough will dip a bit deeper
into the Southeast. This will act to better stack the frontal
system as surface high pressure presses a cold front into our
region. The surface cold front will merge with Sunday`s warm front
and settle in over north Florida before deep layer zonal flow sets
in and stalls the frontal system once again. As the two fronts
merge, and the system stacks, we`ll likely see a brief uptick in
shower activity along the surface front. Expect rainfall to be
much lighter than Sunday afternoon as the surge of more tropical-
like moisture will have moved east.
On Monday, a southern stream impulse will be lifting north
through the northern Gulf, eventually aligning with the surface
front and pressing the northern stream trough back to the north
out of our area. Exactly where the surface front will be is a bit
uncertain, though the most likely scenario would place the front
along or south of I-10 in north Florida, possibly as far south as
the extreme northern Gulf. Should the surface front be positioned
across north Florida, things could become interesting with respect
to the potential for an isolated strong storm. Due to the limited
tropospheric penetration of the southern stream impulse, the mid-
level cooler/drier air will not be forced as aggressively to the
north. This will effectively steepen mid-level lapse rates across
the Tri-State region with deep layer shear around 60 knots more
than sufficient to support organized updrafts. In the other
corner, slightly warmer mid/upper level temps where the northern
stream trough has retreated a bit, will essentially cap the
potential for deep moist convection, though as the southern stream
impulse moves away, cooler mid/upper temps may slide back south late
in the day, eroding the cap. Bottom line is that there is a very low
potential for strong storms on Monday, though should convection
get going, and should the mid/upper level cap erode the potential
exists for a storm or two to produce gusty winds and possibly some
small hail.
Tuesday, is really the more interesting day as a more potent
southern stream impulse races east out of Texas, through the lower
MS Valley and into the southeast by the late afternoon. Should we
be able to mix out the mid-level cap early enough that the
shortwave is overhead, we`d be able to tap into some rather steep
lapse rates and strong deep layer shear. This could support the
development of more severe level storms with the threat for
damaging winds and hail.
So, through Tuesday expect showers and isolated storms to be
around. Most likely across north Florida Monday, spreading further
inland and increasing in coverage on Tuesday. The potential for a
strong storm or two exists on Monday, with a chance for severe
storms on Tuesday. Uncertainty remains very high regarding strong
to severe storms, as my lengthy discussion above lays out all of
the variables that must align just right. Expect above average
temperatures, in the middle to even upper 70s in some spots, both
Monday and Tuesday.
.Long Term [Tuesday Night Through Sunday]...
A cold front will move through Wednesday with a chance of showers
and thunderstorms. Behind the front high pressure will build in
bringing cooler temperatures and drier air. The models differ with
a series of low pressure systems at the end of the period. The GFS
has precipitation moving across central Florida Friday and a low
developing off the East coast near Georgia and South Carolina
followed by another low forming over Texas. The Euro has a Gulf
low forming near the Texas/Louisiana border Friday night then
moving across north Florida Saturday.
.Aviation...
[Through 06Z Monday]
MVFR CIGS should develop during the predawn hours or shortly after
sunrise at ECP, TLH and VLD, lowering to IFR CIGS during
the morning hours. There will be a chance of MVFR CIGS at DHN and
ABY during the day tomorrow as well. With a prolonged rain event
any improvement in evening VSBYS/CIGS will begin to again lower
after 02z and winds die off. Rain and isold thunderstorms will move
in from the west during the morning. Heaviest rain and thunderstorm
activity will likely be focused in Florida Panhandle particularly at
ECP, but also possibly affecting TLH. Main impact would be through
reduced visibility due to very heavy rain. Thunderstorms may also
linger at ECP or TLH south of warm front for several hours in the
afternoon.
.Marine...
Generally low winds and seas will prevail through mid-week until a
cold front passes through the northern Gulf increasing winds to
advisory levels temporarily on Wednesday. Low winds and seas will
return to finish out the week.
.Fire Weather...
With increased rain chances thru tonight, no red flag conditions are
expected and none is forecast through mid-next week.
.Hydrology...
There is a potential for heavy rainfall this afternoon with the
heaviest rain likely confined to north Florida, especially along
and west of the Apalachicola River. Widespread average totals will
be around 1-2 inches with isolated spots possibly receiving up to
3 to 5 inches. Flash flooding will likely not be a concern as
these basins should be able to accommodate the expected rainfall
amounts. In areas where heavy rainfall is expected, rivers may
reach minor flood stage Monday or Tuesday. The Apalachicola at
Blountstown is forecast to reach minor flood stage Sunday morning.
For the latest hydrology information, please monitor:
www.water.weather.gov/ahps2/index.php?wfo=tae
&&
.Preliminary Point Temps/PoPs...
Tallahassee 69 59 75 54 74 / 80 70 40 10 50
Panama City 67 60 70 57 69 / 80 70 40 20 50
Dothan 64 56 73 51 71 / 70 50 10 10 50
Albany 65 55 73 49 72 / 70 50 10 10 40
Valdosta 70 58 75 53 73 / 70 70 40 10 40
Cross City 73 60 75 57 75 / 50 70 40 10 50
Apalachicola 67 61 69 58 67 / 60 70 40 10 50
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...HARRIGAN
SHORT TERM...HARRIGAN
LONG TERM...WESTON
AVIATION...BLOCK
MARINE...HARRIGAN
FIRE WEATHER...BLOCK
HYDROLOGY...HARRIGAN/WESTON
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
355 AM EST Sun Feb 23 2014
...Heavy Rain Possible Across the Florida Panhandle Today...
.Near Term [Through Today]...
The large scale pattern is highlighted by a persistent broad trough
over much of Conus. This leaves nearly zonal flow over NE Gulf
region. However a series of shortwaves will continue to move Ewd
providing increasing clouds and just enough lift that when combined
with surface features will maintain an unsettled weather pattern
today. Mid-High clouds streaming Ewd overnight assocd with lead
shortwave moving Ewd across mid-South will cross NE Gulf region
later today with the forecast area in the right entrance region of
the upper jet. At surface...in response to Ewd moving shortwave...
W-E warm front located across the Nrn Gulf waters Ewd across N/Cntrl
FL overnight will lift Nwd to coast by sunrise then to vcnty of I-10
during the day with light Sly flow in its wake. Upstream cold front
across mid-South around sunrise moves SEWD to Ern TN/N-Cntrl AL/Srn
MS by sundown with WAA and isentropic upglide spreading over our
area. Early radar showing leading edge of moisture approaching wrn
most Panhandle waters.
Patchy to areas of fog initially south of I-10 will accompany rain
and spread E/N thru the day. The combination of upper and lower
features will yield an expansive area of showers with isolated to
sct thunderstorms (highest Panhandle waters) moving SW-NE to reach
our Wrn CWA around sunrise and then progress EWD. Afternoon dew
point will rise from mid 60s coast to upper 50s Nrn tier AL/GA
counties. This depicted well in HRRR and other High Res guidance.
Limited mid-level lapse rates and a relatively cool boundary layer
should limit the potential for any strong storms. Best chance per
CAM would be Panhandle waters. However, with the upper flow parallel
to the warm boundary, main concern is training of cells is possible
with locally heavy rainfall possible especially during the aftn QPF
south of FL border exceeding 1 inch. Will go with 70-30% W-E POP
gradient in morning then 80-40% in the afternoon. Temperatures will
be tricky, depending on the eventual position of the warm front and
the coverage of the rainfall. However, expect warmest temperatures
along and south of I-10 (lower 70s), with lower to mid 60s for much
of SE AL and SW GA.
.Short Term [Tonight Through Tuesday]...
By the time the evening rolls around, the polar jet max will be
racing east and the northern stream trough will dip a bit deeper
into the Southeast. This will act to better stack the frontal
system as surface high pressure presses a cold front into our
region. The surface cold front will merge with Sunday`s warm front
and settle in over north Florida before deep layer zonal flow sets
in and stalls the frontal system once again. As the two fronts
merge, and the system stacks, we`ll likely see a brief uptick in
shower activity along the surface front. Expect rainfall to be
much lighter than Sunday afternoon as the surge of more tropical-
like moisture will have moved east.
On Monday, a southern stream impulse will be lifting north
through the northern Gulf, eventually aligning with the surface
front and pressing the northern stream trough back to the north
out of our area. Exactly where the surface front will be is a bit
uncertain, though the most likely scenario would place the front
along or south of I-10 in north Florida, possibly as far south as
the extreme northern Gulf. Should the surface front be positioned
across north Florida, things could become interesting with respect
to the potential for an isolated strong storm. Due to the limited
tropospheric penetration of the southern stream impulse, the mid-
level cooler/drier air will not be forced as aggressively to the
north. This will effectively steepen mid-level lapse rates across
the Tri-State region with deep layer shear around 60 knots more
than sufficient to support organized updrafts. In the other
corner, slightly warmer mid/upper level temps where the northern
stream trough has retreated a bit, will essentially cap the
potential for deep moist convection, though as the southern stream
impulse moves away, cooler mid/upper temps may slide back south late
in the day, eroding the cap. Bottom line is that there is a very low
potential for strong storms on Monday, though should convection
get going, and should the mid/upper level cap erode the potential
exists for a storm or two to produce gusty winds and possibly some
small hail.
Tuesday, is really the more interesting day as a more potent
southern stream impulse races east out of Texas, through the lower
MS Valley and into the southeast by the late afternoon. Should we
be able to mix out the mid-level cap early enough that the
shortwave is overhead, we`d be able to tap into some rather steep
lapse rates and strong deep layer shear. This could support the
development of more severe level storms with the threat for
damaging winds and hail.
So, through Tuesday expect showers and isolated storms to be
around. Most likely across north Florida Monday, spreading further
inland and increasing in coverage on Tuesday. The potential for a
strong storm or two exists on Monday, with a chance for severe
storms on Tuesday. Uncertainty remains very high regarding strong
to severe storms, as my lengthy discussion above lays out all of
the variables that must align just right. Expect above average
temperatures, in the middle to even upper 70s in some spots, both
Monday and Tuesday.
.Long Term [Tuesday Night Through Sunday]...
A cold front will move through Wednesday with a chance of showers
and thunderstorms. Behind the front high pressure will build in
bringing cooler temperatures and drier air. The models differ with
a series of low pressure systems at the end of the period. The GFS
has precipitation moving across central Florida Friday and a low
developing off the East coast near Georgia and South Carolina
followed by another low forming over Texas. The Euro has a Gulf
low forming near the Texas/Louisiana border Friday night then
moving across north Florida Saturday.
&&
.Aviation...
[Through 06Z Monday]
MVFR CIGS should develop during the predawn hours or shortly after
sunrise at ECP, TLH and VLD, lowering to IFR CIGS during
the morning hours. There will be a chance of MVFR CIGS at DHN and
ABY during the day tomorrow as well. With a prolonged rain event
any improvement in evening VSBYS/CIGS will begin to again lower
after 02z and winds die off. Rain and isold thunderstorms will move
in from the west during the morning. Heaviest rain and thunderstorm
activity will likely be focused in Florida Panhandle particularly at
ECP, but also possibly affecting TLH. Main impact would be through
reduced visibility due to very heavy rain. Thunderstorms may also
linger at ECP or TLH south of warm front for several hours in the
afternoon.
&&
.Marine...
Generally low winds and seas will prevail through mid-week until a
cold front passes through the northern Gulf increasing winds to
advisory levels temporarily on Wednesday. Low winds and seas will
return to finish out the week.
&&
.Fire Weather...
With increased rain chances thru tonight, no red flag conditions are
expected and none is forecast through mid-next week.
&&
.Hydrology...
There is a potential for heavy rainfall this afternoon with the
heaviest rain likely confined to north Florida, especially along
and west of the Apalachicola River. Widespread average totals will
be around 1-2 inches with isolated spots possibly receiving up to
3 to 5 inches. Flash flooding will likely not be a concern as
these basins should be able to accommodate the expected rainfall
amounts. In areas where heavy rainfall is expected, rivers may
reach minor flood stage Monday or Tuesday. The Apalachicola at
Blountstown is forecast to reach minor flood stage Sunday morning.
For the latest hydrology information, please monitor:
www.water.weather.gov/ahps2/index.php?wfo=tae
&&
.Preliminary Point Temps/PoPs...
Tallahassee 69 59 75 54 74 / 70 70 40 10 50
Panama City 67 60 70 57 69 / 80 70 40 20 50
Dothan 64 56 73 51 71 / 70 50 10 10 50
Albany 65 55 73 49 72 / 70 50 10 10 40
Valdosta 70 58 75 53 73 / 70 70 40 10 40
Cross City 73 60 75 57 75 / 50 70 40 10 50
Apalachicola 67 61 69 58 67 / 60 70 40 10 50
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...BLOCK
SHORT TERM...HARRIGAN
LONG TERM...WESTON
AVIATION...BLOCK
MARINE...HARRIGAN
FIRE WEATHER...BLOCK
HYDROLOGY...HARRIGAN/WESTON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
155 PM CST SUN FEB 23 2014
.DISCUSSION...
213 AM CST
TODAY...
BROAD SFC RIDGE STRETCHES FROM THE NORTHERN PLAINS SOUTHEAST
THROUGH THE WESTERN OHIO VALLEY. THIS HAS RESULTED IN A LIGHT
NORTHWEST FLOW ACROSS NORTHERN IL/NORTHWEST IN EARLY THIS MORNING.
BAROCLINIC ZONE REMAINS ORIENTED FROM CENTRAL MO STRETCHING
NORTHEAST THROUGH CENTRAL IL/IN AND DRIFTING SOUTHEAST. IR IMAGERY
SHOWS THE AREA OF CLOUDS WELL...ASSOCIATED WITH THIS BAND OF
PRECIP. THEN JUST WEST OF THIS FEATURE WAS YET ANOTHER WEAK MID-
LVL WAVE THAT HAD ANOTHER AREA OF MID/UPR LVL MOISTURE ASSOCIATED
WITH IT AND WAS SLIDING EAST...BEING STEERED BY THE SEMI-ZONAL
FLOW IN THE MID-LVLS.
TEMPS THIS MORNING WILL HOVER AROUND THE TEENS FOR THE BULK OF THE
FORECAST AREA...PERHAPS HOLDING IN UPR TEENS/LOW 20S FOR THE
SOUTHERN CWFA. OTHERWISE FOR TODAY HIGH PRESSURE WILL PUSH THIS AREA
OF CLOUDS THIS MORNING TO THE SOUTH...AND ALLOW FOR A DRY DAY. SKIES
WILL EVENTUALLY BECOME P-CLOUDY BY MIDDAY...WITH HIGHS WARMING
MAINLY INTO THE 20S. CLOSER TO 30 FOR THE FAR SOUTHERN CWFA.
THEN FOR TONIGHT...HIGH PRESSURE WILL CONTINUE TO HOLD ACROSS THE
FORECAST AREA AND LIMIT CLOUD COVER. JUST NORTH OF THE AREA
THOUGH...AND CLOSER TO A STRONGER MID-LVL VORT WILL BE THICKER CLOUD
COVER. WINDS WILL GENERALLY REMAIN LIGHT FROM THE NORTHWEST...WHICH
COUPLED WITH 850MB TEMPS HOVERING ARND -10 TO -12 DEG C SHOULD LIMIT
HOW COOL TEMPS RADIATE OVERNIGHT. SO HAVE ONLY NUDGED TEMPS DOWN A
LITTLE...GENERALLY IN THE SINGLE DIGITS ABOVE ZERO. COULD SEE SOME
OF THE TRADITIONALLY COOLER LOCATIONS DIP TO ARND ZERO BY DAYBREAK
MON.
CONFIDENCE...HIGH.
MONDAY THROUGH TUESDAY...
500MB TROUGH AXIS OVER THE GREAT LAKES REGION PUSHES EAST...WITH AN
AREA OF WEAK RIDGING ARRIVING MIDDAY MON OVER THE FORECAST AREA.
HOWEVER GIVEN THE SEMI-ZONAL FLOW...WHICH IS GENERALLY A MORE
PROGRESSIVE SETUP...THE NEXT WAVE CONTINUES TO BE PROGGED FOR
ARRIVAL MON LATE AFTN/EVE. LATEST FORECAST GUIDANCE HAS CONTINUED TO
SUGGEST THE MID-LVL HEIGHT RISES MAY BE A LITTLE SLOWER TO DEPART
THE REGION...WHICH WOULD LIKELY HAVE AN INFLUENCE ON THE WEAK WAVE
ARRIVING POSSIBLY LATER. THE MAIN TIMING DOES APPEAR TO BE
CONSISTENT WITH JUST AFT 00Z TUE...AND GIVEN THE PREV-DISCUSSED
PROGRESSIVE FLOW...SKIES WILL THICKEN RATHER QUICKLY AND CIGS WILL
LOWER WITH EASE. LOCAL MODEL INDICATES A SLIGHTLY LATER ARRIVAL AND
CLOSER TO 6Z TUE...BUT ALSO IS INDICATING THE WAVE WILL BE WEAKENING
UPON ARRIVAL. CONFIDENCE ON THIS WAVE WEAKENING AS IT ARRIVES IS
VERY LOW...GIVEN THE DECENT MID-LVL FORCING ASSOCIATED. TEMPS
CONTINUE TO BE COOL ENOUGH TO SUPPORT LGT SNOW FOR THE AREA...AND
EXPECT SLR ARND 15:1 TO 18:1. THIS WILL LIKELY PRODUCE A QUICK 1 TO
2 INCHES OF SNOWFALL ACROSS MOST OF THE CWFA. BY 12-15Z TUE...THE
BULK OF THE WAVE/SNOW WILL BE PUSHING EAST AND COMING TO AN END.
THEN FOR TUE...500MB TROUGH AXIS ARRIVES AS AN ARCTIC AIRMASS
CONTINUES TO PUSH SOUTH FROM CANADA TOWARDS THE UPPER MIDWEST TUE
AFTN. CURRENTLY EXPECT HIGHS TUE TO HOLD IN THE TEENS/LOW
20S...HOWEVER BY TUE NGT THE BOUNDARY WILL BE PUSHING ACROSS THE
FORECAST AREA AND TEMPS WILL BE DROPPING TO A FEW DEGREES BELOW
ZERO.
CONFIDENCE...HIGH.
CONFIDENCE IN SNOW ACCUMS MON EVE/OVERNIGHT...HIGH.
WEDNESDAY THROUGH SUNDAY...
ENSEMBLES AND OPERATIONAL SOLUTIONS HAVE CONTINUED TO BE IN GOOD
AGREEMENT WITH THE ARRIVAL OF YET ANOTHER ARCTIC AIRMASS. BY WED THE
500MB TROUGH AXIS WILL BE OVERHEAD. CURRENT PROGS INDICATE TEMPS IN
MID-LVLS WILL HOVER ARND -20 TO -25 DEG C. WHEN APPLYING THIS
TOWARDS LOCAL CLIMATE WHICH LIKELY YIELD HIGH TEMPS WED IN THE
SINGLE DIGITS ABOVE ZERO TO POSSIBLY THE LOW TEENS. SFC RIDGE WILL
BE SLIDING OVER THE AREA AS WELL...WHICH SHOULD LIMIT HOW MUCH LOWER
WIND CHILL VALUES WILL BE WED. THEN FOR WED NGT...FLOW GRADUALLY
TURNS WESTERLY IN THE LLVLS. A WEAK SHORTWAVE IS PROGGED TO CLIP THE
NORTHERN GREAT LAKES REGION...HOWEVER EXPECT GENERALLY DRY WEATHER
FOR THE FORECAST AREA WED/WED NGT.
FOR THE REMAINDER OF THE EXTENDED PERIODS...ENSEMBLES REMAIN IN
DECENT AGREEMENT WITH YET ANOTHER SFC RIDGE SLIDING SOUTHEAST FROM
CENTRAL CANADA TOWARDS THE PLAINS AND STRETCHING EAST TO THE WESTERN
GREAT LAKES THUR. THIS SHOULD HELP TO MAINTAIN UNSEASONABLY COLD
CONDS FOR THE FORECAST AREA...WITH TEMPS STRUGGLING TO WARM BEYOND
THE LOW/MID TEENS THUR AFTN.
STRONG VORTEX BEGINS TO LIFT NORTHEAST THUR NGT/FRI...WITH SOME
MODERATION TO TEMPS POISED FOR THE END OF THE WEEK INTO THE FIRST
HALF OF NEXT WEEKEND. ALTHOUGH THIS IS RELATIVE...AS TEMPS WILL
CONTINUE TO BE UNSEASONABLY COOL IN THE TEENS/LOW 20S. GUIDANCE IS
SUGGESTING THE SOUTHERN STREAM WILL BECOME ACTIVE YET AGAIN IN THE
LATER PERIODS...AND INDICATES THE PRECIP WILL REMAIN SOUTH OF THE
CWFA. ALTHOUGH COULD SEE SOME ADJUSTMENTS TO THE PLACEMENT OF EACH
SOUTHERN STREAM WAVE.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NONE.
JEE
//DISCUSSION...UPDATED 18Z...
A LARGE SURFACE RIDGE STRETCHES THROUGH THE TERMINALS THIS AFTN
AND IT WILL REMAIN STATIONARY THROUGH THE PERIOD. VFR CONDITIONS
ARE EXPECTED WITH GUSTY W TO NW WINDS THIS AFTN...ARND 18 KT.
GUSTS SUBSIDE THIS EVENING WITH W TO NW WINDS 10-12KT CONTINUING.
GUSTS REDEVELOP BY MID MONDAY MORNING BUT ONLY TO 16 KT. THE
GRADIENT THEN SLACKENS RESULTING IN SUSTAINED 10 KT WEST WINDS
LATE IN THE AFTERNOON. CLOUD COVER WILL THICKEN AS WELL LATE
MONDAY AFTERNOON BUT REMAIN VFR.
LOOKING AHEAD...SNOW IS STILL EXPECTED MONDAY NIGHT INTO TUESDAY
WITH LIGHT ACCUMULATIONS POSSIBLE.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...SNOW LIKELY WITH LIGHT ACCUMULATIONS POSSIBLE.
TUESDAY THROUGH SATURDAY...VFR LIKELY.
BMD
&&
.MARINE...
154 PM CST
LOW PRESSURE CENTERED NEAR JAMES BAY THIS AFTERNOON CONTINUES TO
WEAKEN THIS AFTERNOON. HOWEVER...A BROAD EXPANSIVE RIDGE OF SURFACE
HIGH PRESSURE...EXTENDING FROM THE NORTHERN PLAINS EAST
SOUTHEASTWARD ACROSS THE OHIO VALLEY...IS PRODUCING AN ENHANCED
PRESSURE GRADIENT ACROSS LAKE MICHIGAN. THIS WILL CONTINUE TO
SUPPORT WESTERLY WINDS UP TO 30 KT AT TIMES INTO TONIGHT. GIVEN THAT
SOME OF THESE STRONG WINDS WILL ALSO SET UP ACROSS THE SOUTHERN TIP
OF LAKE MICHIGAN TONIGHT...IT APPEARS WAVES IN THE ICE FREE AREAS OF
NORTHWESTERN INDIANA WILL GET WAVES OVER 4 FEET THROUGH MONDAY.
THEREFORE A SMALL CRAFT ADVISORY WILL BE ISSUED FOR LATE TONIGHT
THROUGH MONDAY EVENING...MAINLY FOR THE NEAR SHORE AREAS EAST OF
GARY INDIANA.
A COUPLE OF CLIPPER TYPE SYSTEMS ARE EXPECTED TO DROP
SOUTHEASTWARD ACROSS THE LAKES REGION THIS WEEK. THE FIRST...WILL
DROP ACROSS SOUTHEASTERN ONTARIO LATE TUESDAY INTO TUESDAY NIGHT.
THIS LOOKS TO RESULT IN AN ENHANCEMENT TO THE WIND FIELD AS A COLD
FRONT DROPS ACROSS THE LAKE LATE TUESDAY AND TURNS TO WINDS OUT OF
THE NORTHWEST UP TO AROUND 30 KT FOR A PERIOD TUESDAY NIGHT INTO
EARLY WEDNESDAY. ANOTHER FAST MOVING CLIPPER SYSTEM IS EXPECTED TO
QUICKLY MOVE IN ACROSS THE GREAT LAKES REGION BY LATE WEDNESDAY.
THIS WILL RESULT IN BACKING WINDS OUT OF THE WEST-SOUTHWEST DURING
THE DAY WEDNESDAY AS SURFACE HIGH PRESSURE SETS UP ACROSS SOUTH
CENTRAL CONUS. WIND SPEEDS DURING THIS PERIOD APPEAR THAT THEY WILL
REACH GALE FORCE IN THE 35 TO 40 KT RANGE. THE WINDS WILL THAN SHIFT
BACK OUT OF THE NORTHWEST WEDNESDAY NIGHT AS ANOTHER STRONG COLD
FRONT PUSHES ACROSS THE LAKE. THESE NORTHWESTERLY WINDS COULD REMAIN
NEAR GALE FORCE FOR A SHORT PERIOD INTO EARLY THURSDAY...BUT AS HIGH
PRESSURE SETS UP OVER THE LAKE ON THURSDAY...WINDS WILL ABATE
SIGNIFICANTLY LATER IN THE DAY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
1128 AM CST Sun Feb 23 2014
.DISCUSSION...
ISSUED 956 AM CST Sun Feb 23 2014
Lingering band of light snow in the southeast CWA has pushed into
Indiana. Radar mosaics still showing quite a few returns along the
I-70 corridor, but these are mostly elevated as surface obs are
showing cloud heights of 7000 feet or higher, so little more than
flurries anticipated the remainder of the morning. Persistent mid
level clouds continue to stream over the remainder of the forecast
area and should continue through the afternoon. Lowered
temperatures a couple degrees across the southeast CWA as they
had continued to slip downward as the snow began a few hours ago,
but the forecast over the remainder of the area still is in decent
shape.
Geelhart
&&
.AVIATION...
ISSUED 1125 AM CST Sun Feb 23 2014
VFR conditions expected through the period, with ceilings
generally above 10,000 feet. Most likely period for skies to be
clear will be 06-12Z. After that, mid-level clouds will rapidly
increase from the northwest Monday morning ahead of the next
clipper system, although any associated precipitation is not
expected until early evening. Northwest winds to persist through
the period, due to high pressure over the Dakotas.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 330 AM CST Sun Feb 23 2014
SHORT TERM...Today through Wednesday night
Surface cold front has pressed south of the Ohio River into NW AR
while 1042 mb arctic high pressure over Alberta was nosing into
the central and northern plains. Colder air easing south into
central IL early this morning with temps slipping through the 20s
over central IL and low to mid 30s in southeast IL. Temps as cold
as 19F at Galesburg and Lacon. Frontogenetic forecasting close to
850 mb boundary near I-70 had band of light snow that diminished
east into central IN past few hours with dusting to as much as 1
inch between I-72 and I-70. Will carry just slight chance of light
snow this morning over southeast IL per HRRR model run. Radar
mosaic shows light pcpn returns and mainly virga over northern MO
into NW counties. RUC & HRRR keeps most of this very light snow
west of central IL this morning but could be a few flurries this
morning into central IL. Clouds to decrease from the north during
the afternoon and linger longest in southeast IL. Much colder
highs today range from mid 20s from Peoria and Bloomington north
to 35-40F over southeast IL with Lawrenceville near 40F.
Arctic high pressure noses into the mid MS river valley tonight
and brings fair skies and cold lows of 5-10F from Lincoln north
and mid to upper teens in southeast IL. Clouds increase Monday
morning ahead of northern stream clipper system which digs into
the Midwest Monday night. Slowed down chances of light snow Monday
afternoon as central IL appear dry through sunset Monday with best
chances of light snow arriving Monday night northern half of CWA.
Generally less than 1 inch of snow with northern IL having as much
as 1-2 inches of snow possible. Highs Monday again in mid 20s
north and mid to upper 30s in southeast IL. Lows Monday night in
the teens central IL and lower 20s southeast IL. Chances of light
snow NE of central IL by Tuesday morning. Highs Tue range from
lower 20s northern areas to mid 30s in southeast IL.
Core of arctic high pressure settles into MO by 18Z/noon Wed and
brings even colder air into the region during middle of the week.
Lows overnight Tue night into early Wed morning could reach zero
to 5 below NW of IL river with single digit lows over much of
central IL and far southeast IL around 10F. Highs Wed in the mid
teens NE to lower 20s SW and SE areas. Lows Wed night again in the
single digits over northern half of CWA and lower teens south.
LONG TERM...Thursday through Saturday night
Temps modify slightly during end of week but still average below
normal through next weekend. The 8-14 day outlook for Mar 2-8 has
60-70% chance of below normal temperatures and 40% chance of above
normal precipitation, which has been the normal for this winter.
Generally dry and cold conditions expected late this week into
next weekend. Though ECMWF and GEM models show some light QPF
Friday while heavier QPF passes south of IL Friday. GFS model is
dry over IL on Friday. Stayed close to ALLblend pops late this
week and into the weekend which is dry.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1120 AM CST SUN FEB 23 2014
.DISCUSSION...
213 AM CST
TODAY...
BROAD SFC RIDGE STRETCHES FROM THE NORTHERN PLAINS SOUTHEAST
THROUGH THE WESTERN OHIO VALLEY. THIS HAS RESULTED IN A LIGHT
NORTHWEST FLOW ACROSS NORTHERN IL/NORTHWEST IN EARLY THIS MORNING.
BAROCLINIC ZONE REMAINS ORIENTED FROM CENTRAL MO STRETCHING
NORTHEAST THROUGH CENTRAL IL/IN AND DRIFTING SOUTHEAST. IR IMAGERY
SHOWS THE AREA OF CLOUDS WELL...ASSOCIATED WITH THIS BAND OF
PRECIP. THEN JUST WEST OF THIS FEATURE WAS YET ANOTHER WEAK MID-
LVL WAVE THAT HAD ANOTHER AREA OF MID/UPR LVL MOISTURE ASSOCIATED
WITH IT AND WAS SLIDING EAST...BEING STEERED BY THE SEMI-ZONAL
FLOW IN THE MID-LVLS.
TEMPS THIS MORNING WILL HOVER AROUND THE TEENS FOR THE BULK OF THE
FORECAST AREA...PERHAPS HOLDING IN UPR TEENS/LOW 20S FOR THE
SOUTHERN CWFA. OTHERWISE FOR TODAY HIGH PRESSURE WILL PUSH THIS AREA
OF CLOUDS THIS MORNING TO THE SOUTH...AND ALLOW FOR A DRY DAY. SKIES
WILL EVENTUALLY BECOME P-CLOUDY BY MIDDAY...WITH HIGHS WARMING
MAINLY INTO THE 20S. CLOSER TO 30 FOR THE FAR SOUTHERN CWFA.
THEN FOR TONIGHT...HIGH PRESSURE WILL CONTINUE TO HOLD ACROSS THE
FORECAST AREA AND LIMIT CLOUD COVER. JUST NORTH OF THE AREA
THOUGH...AND CLOSER TO A STRONGER MID-LVL VORT WILL BE THICKER CLOUD
COVER. WINDS WILL GENERALLY REMAIN LIGHT FROM THE NORTHWEST...WHICH
COUPLED WITH 850MB TEMPS HOVERING ARND -10 TO -12 DEG C SHOULD LIMIT
HOW COOL TEMPS RADIATE OVERNIGHT. SO HAVE ONLY NUDGED TEMPS DOWN A
LITTLE...GENERALLY IN THE SINGLE DIGITS ABOVE ZERO. COULD SEE SOME
OF THE TRADITIONALLY COOLER LOCATIONS DIP TO ARND ZERO BY DAYBREAK
MON.
CONFIDENCE...HIGH.
MONDAY THROUGH TUESDAY...
500MB TROUGH AXIS OVER THE GREAT LAKES REGION PUSHES EAST...WITH AN
AREA OF WEAK RIDGING ARRIVING MIDDAY MON OVER THE FORECAST AREA.
HOWEVER GIVEN THE SEMI-ZONAL FLOW...WHICH IS GENERALLY A MORE
PROGRESSIVE SETUP...THE NEXT WAVE CONTINUES TO BE PROGGED FOR
ARRIVAL MON LATE AFTN/EVE. LATEST FORECAST GUIDANCE HAS CONTINUED TO
SUGGEST THE MID-LVL HEIGHT RISES MAY BE A LITTLE SLOWER TO DEPART
THE REGION...WHICH WOULD LIKELY HAVE AN INFLUENCE ON THE WEAK WAVE
ARRIVING POSSIBLY LATER. THE MAIN TIMING DOES APPEAR TO BE
CONSISTENT WITH JUST AFT 00Z TUE...AND GIVEN THE PREV-DISCUSSED
PROGRESSIVE FLOW...SKIES WILL THICKEN RATHER QUICKLY AND CIGS WILL
LOWER WITH EASE. LOCAL MODEL INDICATES A SLIGHTLY LATER ARRIVAL AND
CLOSER TO 6Z TUE...BUT ALSO IS INDICATING THE WAVE WILL BE WEAKENING
UPON ARRIVAL. CONFIDENCE ON THIS WAVE WEAKENING AS IT ARRIVES IS
VERY LOW...GIVEN THE DECENT MID-LVL FORCING ASSOCIATED. TEMPS
CONTINUE TO BE COOL ENOUGH TO SUPPORT LGT SNOW FOR THE AREA...AND
EXPECT SLR ARND 15:1 TO 18:1. THIS WILL LIKELY PRODUCE A QUICK 1 TO
2 INCHES OF SNOWFALL ACROSS MOST OF THE CWFA. BY 12-15Z TUE...THE
BULK OF THE WAVE/SNOW WILL BE PUSHING EAST AND COMING TO AN END.
THEN FOR TUE...500MB TROUGH AXIS ARRIVES AS AN ARCTIC AIRMASS
CONTINUES TO PUSH SOUTH FROM CANADA TOWARDS THE UPPER MIDWEST TUE
AFTN. CURRENTLY EXPECT HIGHS TUE TO HOLD IN THE TEENS/LOW
20S...HOWEVER BY TUE NGT THE BOUNDARY WILL BE PUSHING ACROSS THE
FORECAST AREA AND TEMPS WILL BE DROPPING TO A FEW DEGREES BELOW
ZERO.
CONFIDENCE...HIGH.
CONFIDENCE IN SNOW ACCUMS MON EVE/OVERNIGHT...HIGH.
WEDNESDAY THROUGH SUNDAY...
ENSEMBLES AND OPERATIONAL SOLUTIONS HAVE CONTINUED TO BE IN GOOD
AGREEMENT WITH THE ARRIVAL OF YET ANOTHER ARCTIC AIRMASS. BY WED THE
500MB TROUGH AXIS WILL BE OVERHEAD. CURRENT PROGS INDICATE TEMPS IN
MID-LVLS WILL HOVER ARND -20 TO -25 DEG C. WHEN APPLYING THIS
TOWARDS LOCAL CLIMATE WHICH LIKELY YIELD HIGH TEMPS WED IN THE
SINGLE DIGITS ABOVE ZERO TO POSSIBLY THE LOW TEENS. SFC RIDGE WILL
BE SLIDING OVER THE AREA AS WELL...WHICH SHOULD LIMIT HOW MUCH LOWER
WIND CHILL VALUES WILL BE WED. THEN FOR WED NGT...FLOW GRADUALLY
TURNS WESTERLY IN THE LLVLS. A WEAK SHORTWAVE IS PROGGED TO CLIP THE
NORTHERN GREAT LAKES REGION...HOWEVER EXPECT GENERALLY DRY WEATHER
FOR THE FORECAST AREA WED/WED NGT.
FOR THE REMAINDER OF THE EXTENDED PERIODS...ENSEMBLES REMAIN IN
DECENT AGREEMENT WITH YET ANOTHER SFC RIDGE SLIDING SOUTHEAST FROM
CENTRAL CANADA TOWARDS THE PLAINS AND STRETCHING EAST TO THE WESTERN
GREAT LAKES THUR. THIS SHOULD HELP TO MAINTAIN UNSEASONABLY COLD
CONDS FOR THE FORECAST AREA...WITH TEMPS STRUGGLING TO WARM BEYOND
THE LOW/MID TEENS THUR AFTN.
STRONG VORTEX BEGINS TO LIFT NORTHEAST THUR NGT/FRI...WITH SOME
MODERATION TO TEMPS POISED FOR THE END OF THE WEEK INTO THE FIRST
HALF OF NEXT WEEKEND. ALTHOUGH THIS IS RELATIVE...AS TEMPS WILL
CONTINUE TO BE UNSEASONABLY COOL IN THE TEENS/LOW 20S. GUIDANCE IS
SUGGESTING THE SOUTHERN STREAM WILL BECOME ACTIVE YET AGAIN IN THE
LATER PERIODS...AND INDICATES THE PRECIP WILL REMAIN SOUTH OF THE
CWFA. ALTHOUGH COULD SEE SOME ADJUSTMENTS TO THE PLACEMENT OF EACH
SOUTHERN STREAM WAVE.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* NONE.
JEE
//DISCUSSION...UPDATED 18Z...
A LARGE SURFACE RIDGE STRETCHES THROUGH THE TERMINALS THIS AFTN
AND IT WILL REMAIN STATIONARY THROUGH THE PERIOD. VFR CONDITIONS
ARE EXPECTED WITH GUSTY W TO NW WINDS THIS AFTN...ARND 18 KT.
GUSTS SUBSIDE THIS EVENING WITH W TO NW WINDS 10-12KT CONTINUING.
GUSTS REDEVELOP BY MID MONDAY MORNING BUT ONLY TO 16 KT. THE
GRADIENT THEN SLACKENS RESULTING IN SUSTAINED 10 KT WEST WINDS
LATE IN THE AFTERNOON. CLOUD COVER WILL THICKEN AS WELL LATE
MONDAY AFTERNOON BUT REMAIN VFR.
LOOKING AHEAD...SNOW IS STILL EXPECTED MONDAY NIGHT INTO TUESDAY
WITH LIGHT ACCUMULATIONS POSSIBLE.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...SNOW LIKELY WITH LIGHT ACCUMULATIONS POSSIBLE.
TUESDAY THROUGH SATURDAY...VFR LIKELY.
BMD
&&
.MARINE...
302 AM CST
MODERATE WEST TO NORTHWEST WINDS ARE EXPECTED TO CONTINUE THROUGH
THE REMAINDER OF THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK ACROSS
LAKE MICHIGAN ON THE EASTERN PERIPHERY OF A STRONG RIDGE THAT
EXTENDS FROM THE CANADIAN ROCKIES INTO THE OHIO VALLEY. WINDS WILL
GENERALLY BE IN THE 20 TO 30 KT RANGE THROUGH TUESDAY...THEN A
SERIES OF LOWS WILL DROP FROM CANADA INTO THE GREAT LAKES
REGION...THE STRONGEST OF WHICH WILL BE WEDNESDAY NIGHT. A SURGE OF
ARCTIC AIR WILL OVERSPREAD THE WESTERN LAKES BEHIND THIS LOW AND A
PERIOD OF NORTHWESTERLY GALES IS POSSIBLE...ALONG WITH FREEZING
SPRAY. THE RIDGE WILL START TO BUILD CLOSER TO LAKE MICHIGAN LATER
IN THE WEEK AND INTO THE WEEKEND WITH WINDS DIMINISHING.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
957 AM CST Sun Feb 23 2014
.DISCUSSION...
ISSUED 956 AM CST Sun Feb 23 2014
Lingering band of light snow in the southeast CWA has pushed into
Indiana. Radar mosaics still showing quite a few returns along the
I-70 corridor, but these are mostly elevated as surface obs are
showing cloud heights of 7000 feet or higher, so little more than
flurries anticipated the remainder of the morning. Persistent mid
level clouds continue to stream over the remainder of the forecast
area and should continue through the afternoon. Lowered
temperatures a couple degrees across the southeast CWA as they
had continued to slip downward as the snow began a few hours ago,
but the forecast over the remainder of the area still is in decent
shape.
Geelhart
&&
.AVIATION...
ISSUED 540 AM CST Sun Feb 23 2014
VFR conditions will prevail at all TAF sites next 24hrs. Mid
clouds around 9kft will overspread all sites this morning and
remain over the area/sites through the morning and into the
afternoon. Models indicate that the clouds will slide south away
from the TAF sites this afternoon, but satellite loop/trends show
clouds moving due east. So will keep at least BKN mid clouds over
the area into this evening. Then skies will clear around midnight.
Winds will be northerly to start and then shifts to northwesterly
as a high pressure ridge pushes into the area late this afternoon
and into the evening.
Auten
&&
.PREV DISCUSSION...
ISSUED 330 AM CST Sun Feb 23 2014
SHORT TERM...Today through Wednesday night
Surface cold front has pressed south of the Ohio River into NW AR
while 1042 mb arctic high pressure over Alberta was nosing into
the central and northern plains. Colder air easing south into
central IL early this morning with temps slipping through the 20s
over central IL and low to mid 30s in southeast IL. Temps as cold
as 19F at Galesburg and Lacon. Frontogenetic forecasting close to
850 mb boundary near I-70 had band of light snow that diminished
east into central IN past few hours with dusting to as much as 1
inch between I-72 and I-70. Will carry just slight chance of light
snow this morning over southeast IL per HRRR model run. Radar
mosaic shows light pcpn returns and mainly virga over northern MO
into NW counties. RUC & HRRR keeps most of this very light snow
west of central IL this morning but could be a few flurries this
morning into central IL. Clouds to decrease from the north during
the afternoon and linger longest in southeast IL. Much colder
highs today range from mid 20s from Peoria and Bloomington north
to 35-40F over southeast IL with Lawrenceville near 40F.
Arctic high pressure noses into the mid MS river valley tonight
and brings fair skies and cold lows of 5-10F from Lincoln north
and mid to upper teens in southeast IL. Clouds increase Monday
morning ahead of northern stream clipper system which digs into
the Midwest Monday night. Slowed down chances of light snow Monday
afternoon as central IL appear dry through sunset Monday with best
chances of light snow arriving Monday night northern half of CWA.
Generally less than 1 inch of snow with northern IL having as much
as 1-2 inches of snow possible. Highs Monday again in mid 20s
north and mid to upper 30s in southeast IL. Lows Monday night in
the teens central IL and lower 20s southeast IL. Chances of light
snow NE of central IL by Tuesday morning. Highs Tue range from
lower 20s northern areas to mid 30s in southeast IL.
Core of arctic high pressure settles into MO by 18Z/noon Wed and
brings even colder air into the region during middle of the week.
Lows overnight Tue night into early Wed morning could reach zero
to 5 below NW of IL river with single digit lows over much of
central IL and far southeast IL around 10F. Highs Wed in the mid
teens NE to lower 20s SW and SE areas. Lows Wed night again in the
single digits over northern half of CWA and lower teens south.
LONG TERM...Thursday through Saturday night
Temps modify slightly during end of week but still average below
normal through next weekend. The 8-14 day outlook for Mar 2-8 has
60-70% chance of below normal temperatures and 40% chance of above
normal precipitation, which has been the normal for this winter.
Generally dry and cold conditions expected late this week into
next weekend. Though ECMWF and GEM models show some light QPF
Friday while heavier QPF passes south of IL Friday. GFS model is
dry over IL on Friday. Stayed close to ALLblend pops late this
week and into the weekend which is dry.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
543 AM CST SUN FEB 23 2014
.DISCUSSION...
213 AM CST
TODAY...
BROAD SFC RIDGE STRETCHES FROM THE NORTHERN PLAINS SOUTHEAST
THROUGH THE WESTERN OHIO VALLEY. THIS HAS RESULTED IN A LIGHT
NORTHWEST FLOW ACROSS NORTHERN IL/NORTHWEST IN EARLY THIS MORNING.
BAROCLINIC ZONE REMAINS ORIENTED FROM CENTRAL MO STRETCHING
NORTHEAST THROUGH CENTRAL IL/IN AND DRIFTING SOUTHEAST. IR IMAGERY
SHOWS THE AREA OF CLOUDS WELL...ASSOCIATED WITH THIS BAND OF
PRECIP. THEN JUST WEST OF THIS FEATURE WAS YET ANOTHER WEAK MID-
LVL WAVE THAT HAD ANOTHER AREA OF MID/UPR LVL MOISTURE ASSOCIATED
WITH IT AND WAS SLIDING EAST...BEING STEERED BY THE SEMI-ZONAL
FLOW IN THE MID-LVLS.
TEMPS THIS MORNING WILL HOVER AROUND THE TEENS FOR THE BULK OF THE
FORECAST AREA...PERHAPS HOLDING IN UPR TEENS/LOW 20S FOR THE
SOUTHERN CWFA. OTHERWISE FOR TODAY HIGH PRESSURE WILL PUSH THIS AREA
OF CLOUDS THIS MORNING TO THE SOUTH...AND ALLOW FOR A DRY DAY. SKIES
WILL EVENTUALLY BECOME P-CLOUDY BY MIDDAY...WITH HIGHS WARMING
MAINLY INTO THE 20S. CLOSER TO 30 FOR THE FAR SOUTHERN CWFA.
THEN FOR TONIGHT...HIGH PRESSURE WILL CONTINUE TO HOLD ACROSS THE
FORECAST AREA AND LIMIT CLOUD COVER. JUST NORTH OF THE AREA
THOUGH...AND CLOSER TO A STRONGER MID-LVL VORT WILL BE THICKER CLOUD
COVER. WINDS WILL GENERALLY REMAIN LIGHT FROM THE NORTHWEST...WHICH
COUPLED WITH 850MB TEMPS HOVERING ARND -10 TO -12 DEG C SHOULD LIMIT
HOW COOL TEMPS RADIATE OVERNIGHT. SO HAVE ONLY NUDGED TEMPS DOWN A
LITTLE...GENERALLY IN THE SINGLE DIGITS ABOVE ZERO. COULD SEE SOME
OF THE TRADITIONALLY COOLER LOCATIONS DIP TO ARND ZERO BY DAYBREAK
MON.
CONFIDENCE...HIGH.
MONDAY THROUGH TUESDAY...
500MB TROUGH AXIS OVER THE GREAT LAKES REGION PUSHES EAST...WITH AN
AREA OF WEAK RIDGING ARRIVING MIDDAY MON OVER THE FORECAST AREA.
HOWEVER GIVEN THE SEMI-ZONAL FLOW...WHICH IS GENERALLY A MORE
PROGRESSIVE SETUP...THE NEXT WAVE CONTINUES TO BE PROGGED FOR
ARRIVAL MON LATE AFTN/EVE. LATEST FORECAST GUIDANCE HAS CONTINUED TO
SUGGEST THE MID-LVL HEIGHT RISES MAY BE A LITTLE SLOWER TO DEPART
THE REGION...WHICH WOULD LIKELY HAVE AN INFLUENCE ON THE WEAK WAVE
ARRIVING POSSIBLY LATER. THE MAIN TIMING DOES APPEAR TO BE
CONSISTENT WITH JUST AFT 00Z TUE...AND GIVEN THE PREV-DISCUSSED
PROGRESSIVE FLOW...SKIES WILL THICKEN RATHER QUICKLY AND CIGS WILL
LOWER WITH EASE. LOCAL MODEL INDICATES A SLIGHTLY LATER ARRIVAL AND
CLOSER TO 6Z TUE...BUT ALSO IS INDICATING THE WAVE WILL BE WEAKENING
UPON ARRIVAL. CONFIDENCE ON THIS WAVE WEAKENING AS IT ARRIVES IS
VERY LOW...GIVEN THE DECENT MID-LVL FORCING ASSOCIATED. TEMPS
CONTINUE TO BE COOL ENOUGH TO SUPPORT LGT SNOW FOR THE AREA...AND
EXPECT SLR ARND 15:1 TO 18:1. THIS WILL LIKELY PRODUCE A QUICK 1 TO
2 INCHES OF SNOWFALL ACROSS MOST OF THE CWFA. BY 12-15Z TUE...THE
BULK OF THE WAVE/SNOW WILL BE PUSHING EAST AND COMING TO AN END.
THEN FOR TUE...500MB TROUGH AXIS ARRIVES AS AN ARCTIC AIRMASS
CONTINUES TO PUSH SOUTH FROM CANADA TOWARDS THE UPPER MIDWEST TUE
AFTN. CURRENTLY EXPECT HIGHS TUE TO HOLD IN THE TEENS/LOW
20S...HOWEVER BY TUE NGT THE BOUNDARY WILL BE PUSHING ACROSS THE
FORECAST AREA AND TEMPS WILL BE DROPPING TO A FEW DEGREES BELOW
ZERO.
CONFIDENCE...HIGH.
CONFIDENCE IN SNOW ACCUMS MON EVE/OVERNIGHT...HIGH.
WEDNESDAY THROUGH SUNDAY...
ENSEMBLES AND OPERATIONAL SOLUTIONS HAVE CONTINUED TO BE IN GOOD
AGREEMENT WITH THE ARRIVAL OF YET ANOTHER ARCTIC AIRMASS. BY WED THE
500MB TROUGH AXIS WILL BE OVERHEAD. CURRENT PROGS INDICATE TEMPS IN
MID-LVLS WILL HOVER ARND -20 TO -25 DEG C. WHEN APPLYING THIS
TOWARDS LOCAL CLIMATE WHICH LIKELY YIELD HIGH TEMPS WED IN THE
SINGLE DIGITS ABOVE ZERO TO POSSIBLY THE LOW TEENS. SFC RIDGE WILL
BE SLIDING OVER THE AREA AS WELL...WHICH SHOULD LIMIT HOW MUCH LOWER
WIND CHILL VALUES WILL BE WED. THEN FOR WED NGT...FLOW GRADUALLY
TURNS WESTERLY IN THE LLVLS. A WEAK SHORTWAVE IS PROGGED TO CLIP THE
NORTHERN GREAT LAKES REGION...HOWEVER EXPECT GENERALLY DRY WEATHER
FOR THE FORECAST AREA WED/WED NGT.
FOR THE REMAINDER OF THE EXTENDED PERIODS...ENSEMBLES REMAIN IN
DECENT AGREEMENT WITH YET ANOTHER SFC RIDGE SLIDING SOUTHEAST FROM
CENTRAL CANADA TOWARDS THE PLAINS AND STRETCHING EAST TO THE WESTERN
GREAT LAKES THUR. THIS SHOULD HELP TO MAINTAIN UNSEASONABLY COLD
CONDS FOR THE FORECAST AREA...WITH TEMPS STRUGGLING TO WARM BEYOND
THE LOW/MID TEENS THUR AFTN.
STRONG VORTEX BEGINS TO LIFT NORTHEAST THUR NGT/FRI...WITH SOME
MODERATION TO TEMPS POISED FOR THE END OF THE WEEK INTO THE FIRST
HALF OF NEXT WEEKEND. ALTHOUGH THIS IS RELATIVE...AS TEMPS WILL
CONTINUE TO BE UNSEASONABLY COOL IN THE TEENS/LOW 20S. GUIDANCE IS
SUGGESTING THE SOUTHERN STREAM WILL BECOME ACTIVE YET AGAIN IN THE
LATER PERIODS...AND INDICATES THE PRECIP WILL REMAIN SOUTH OF THE
CWFA. ALTHOUGH COULD SEE SOME ADJUSTMENTS TO THE PLACEMENT OF EACH
SOUTHERN STREAM WAVE.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* NONE
//DISCUSSION...UPDATED 12Z...
A RIDGE OF HIGH PRESSURE EXTENDS FROM THE NORTHERN PLAINS INTO
CENTRAL ILLINOIS EARLY THIS MORNING AND WILL REMAIN RELATIVELY
STATIONARY THROUGH THE FORECAST PERIOD PROVIDING QUIET WEATHER WITH
VFR CONDITIONS AND WNW WINDS. A FEW GUSTS INTO THE HIGH TEENS TO
AROUND 20 KT ARE POSSIBLE THIS AFTERNOON AND EARLY EVENING...THEN
SHOULD TAPER MID TO LATE IN THE EVENING. THE NEXT CHANCE FOR ANY
SIGNIFICANT WEATHER IMPACTS APPEARS TO BE MONDAY NIGHT INTO TUESDAY
WHEN SNOW WILL MOVE ACROSS THE AREA WITH LIGHT ACCUMULATIONS
POSSIBLE.
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...SNOW LIKELY WITH LIGHT ACCUMULATIONS POSSIBLE.
TUESDAY THROUGH SATURDAY...VFR LIKELY.
BMD
&&
.MARINE...
302 AM CST
MODERATE WEST TO NORTHWEST WINDS ARE EXPECTED TO CONTINUE THROUGH
THE REMAINDER OF THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK ACROSS
LAKE MICHIGAN ON THE EASTERN PERIPHERY OF A STRONG RIDGE THAT
EXTENDS FROM THE CANADIAN ROCKIES INTO THE OHIO VALLEY. WINDS WILL
GENERALLY BE IN THE 20 TO 30 KT RANGE THROUGH TUESDAY...THEN A
SERIES OF LOWS WILL DROP FROM CANADA INTO THE GREAT LAKES
REGION...THE STRONGEST OF WHICH WILL BE WEDNESDAY NIGHT. A SURGE OF
ARCTIC AIR WILL OVERSPREAD THE WESTERN LAKES BEHIND THIS LOW AND A
PERIOD OF NORTHWESTERLY GALES IS POSSIBLE...ALONG WITH FREEZING
SPRAY. THE RIDGE WILL START TO BUILD CLOSER TO LAKE MICHIGAN LATER
IN THE WEEK AND INTO THE WEEKEND WITH WINDS DIMINISHING.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
540 AM CST Sun Feb 23 2014
.DISCUSSION...
ISSUED 330 AM CST Sun Feb 23 2014
SHORT TERM...Today through Wednesday night
Surface cold front has pressed south of the Ohio River into nw AR
while 1042 mb arctic high pressure over Alberta was nosing into
the central and northern plains. Colder air easing south into
central IL early this morning with temps slipping through the 20s
over central IL and low to mid 30s in southeast IL. Temps as cold
as 19F at Galesburg and Lacon. Frontogenetic forecasting close to
850 mb boundary near I-70 had band of light snow that diminished
east into central IN past few hours with dusting to as much as 1
inch between I-72 and I-70. Will carry just slight chance of light
snow this morning over southeast IL per HRRR model run. Radar
mosaic shows light pcpn returns and mainly virga over northern MO
into nw counties. RUC & HRRR keeps most of this very light snow
west of central IL this morning but could be a few flurries this
morning into central IL. Clouds to decrease from the north during
the afternoon and linger longest in southeast IL. Much colder
highs today range from mid 20s from Peoria and Bloomington north
to 35-40F over southeast IL with Lawrenceville near 40F.
Arctic high pressure noses into the mid MS river valley tonight
and brings fair skies and cold lows of 5-10F from Lincoln north
and mid to upper teens in southeast IL. Clouds increase Monday
morning ahead of northern stream clipper system which digs into
the Midwest Monday night. Slowed down chances of light snow Monday
afternoon as central IL appear dry through sunset Monday with best
chances of light snow arriving Monday night northern half of CWA.
Generally less than 1 inch of snow with northern IL having as much
as 1-2 inches of snow possible. Highs Monday again in mid 20s
north and mid to upper 30s in southeast IL. Lows Monday night in
the teens central IL and lower 20s southeast IL. Chances of light
snow ne of central IL by Tuesday morning. Highs Tue range from
lower 20s northern areas to mid 30s in southeast IL.
Core of arctic high pressure settles into MO by 18Z/noon Wed and
brings even colder air into the region during middle of the week.
Lows overnight Tue night into early Wed morning could reach zero
to 5 below nw of IL river with single digit lows over much of
central IL and far southeast IL around 10F. Highs Wed in the mid
teens ne to lower 20s sw and se areas. Lows Wed night again in the
single digits over northern half of CWA and lower teens south.
LONG TERM...Thursday through Saturday night
Temps modify slightly during end of week but still average below
normal through next weekend. The 8-14 day outlook for Mar 2-8 has
60-70% chance of below normal temperatures and 40% chance of above
normal precipitation, which has been the normal for this winter.
Generally dry and cold conditions expected late this week into
next weekend. Though ECMWF and GEM models show some light qpf
Friday while heavier qpf passes south of IL Friday. GFS model is
dry over IL on Friday. Stayed close to ALLblend pops late this
week and into the weekend which is dry.
07
&&
.AVIATION...
ISSUED 540 AM CST Sun Feb 23 2014
VFR conditions will prevail at all TAF sites next 24hrs. Mid
clouds around 9kft will overspread all sites this morning and
remain over the area/sites through the morning and into the
afternoon. Models indicate that the clouds will slide south away
from the TAF sites this afternoon, but satellite loop/trends show
clouds moving due east. So will keep at least BKN mid clouds over
the area into this evening. Then skies will clear around midnight.
Winds will be northerly to start and then shifts to northwesterly
as a high pressure ridge pushes into the area late this afternoon
and into the evening.
Auten
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
214 AM CST SUN FEB 23 2014
.DISCUSSION...
213 AM CST
TODAY...
BROAD SFC RIDGE STRETCHES FROM THE NORTHERN PLAINS SOUTHEAST
THROUGH THE WESTERN OHIO VALLEY. THIS HAS RESULTED IN A LIGHT
NORTHWEST FLOW ACROSS NORTHERN IL/NORTHWEST IN EARLY THIS MORNING.
BAROCLINIC ZONE REMAINS ORIENTED FROM CENTRAL MO STRETCHING
NORTHEAST THROUGH CENTRAL IL/IN AND DRIFTING SOUTHEAST. IR IMAGERY
SHOWS THE AREA OF CLOUDS WELL...ASSOCIATED WITH THIS BAND OF
PRECIP. THEN JUST WEST OF THIS FEATURE WAS YET ANOTHER WEAK MID-
LVL WAVE THAT HAD ANOTHER AREA OF MID/UPR LVL MOISTURE ASSOCIATED
WITH IT AND WAS SLIDING EAST...BEING STEERED BY THE SEMI-ZONAL
FLOW IN THE MID-LVLS.
TEMPS THIS MORNING WILL HOVER AROUND THE TEENS FOR THE BULK OF THE
FORECAST AREA...PERHAPS HOLDING IN UPR TEENS/LOW 20S FOR THE
SOUTHERN CWFA. OTHERWISE FOR TODAY HIGH PRESSURE WILL PUSH THIS AREA
OF CLOUDS THIS MORNING TO THE SOUTH...AND ALLOW FOR A DRY DAY. SKIES
WILL EVENTUALLY BECOME P-CLOUDY BY MIDDAY...WITH HIGHS WARMING
MAINLY INTO THE 20S. CLOSER TO 30 FOR THE FAR SOUTHERN CWFA.
THEN FOR TONIGHT...HIGH PRESSURE WILL CONTINUE TO HOLD ACROSS THE
FORECAST AREA AND LIMIT CLOUD COVER. JUST NORTH OF THE AREA
THOUGH...AND CLOSER TO A STRONGER MID-LVL VORT WILL BE THICKER CLOUD
COVER. WINDS WILL GENERALLY REMAIN LIGHT FROM THE NORTHWEST...WHICH
COUPLED WITH 850MB TEMPS HOVERING ARND -10 TO -12 DEG C SHOULD LIMIT
HOW COOL TEMPS RADIATE OVERNIGHT. SO HAVE ONLY NUDGED TEMPS DOWN A
LITTLE...GENERALLY IN THE SINGLE DIGITS ABOVE ZERO. COULD SEE SOME
OF THE TRADITIONALLY COOLER LOCATIONS DIP TO ARND ZERO BY DAYBREAK
MON.
CONFIDENCE...HIGH.
MONDAY THROUGH TUESDAY...
500MB TROUGH AXIS OVER THE GREAT LAKES REGION PUSHES EAST...WITH AN
AREA OF WEAK RIDGING ARRIVING MIDDAY MON OVER THE FORECAST AREA.
HOWEVER GIVEN THE SEMI-ZONAL FLOW...WHICH IS GENERALLY A MORE
PROGRESSIVE SETUP...THE NEXT WAVE CONTINUES TO BE PROGGED FOR
ARRIVAL MON LATE AFTN/EVE. LATEST FORECAST GUIDANCE HAS CONTINUED TO
SUGGEST THE MID-LVL HEIGHT RISES MAY BE A LITTLE SLOWER TO DEPART
THE REGION...WHICH WOULD LIKELY HAVE AN INFLUENCE ON THE WEAK WAVE
ARRIVING POSSIBLY LATER. THE MAIN TIMING DOES APPEAR TO BE
CONSISTENT WITH JUST AFT 00Z TUE...AND GIVEN THE PREV-DISCUSSED
PROGRESSIVE FLOW...SKIES WILL THICKEN RATHER QUICKLY AND CIGS WILL
LOWER WITH EASE. LOCAL MODEL INDICATES A SLIGHTLY LATER ARRIVAL AND
CLOSER TO 6Z TUE...BUT ALSO IS INDICATING THE WAVE WILL BE WEAKENING
UPON ARRIVAL. CONFIDENCE ON THIS WAVE WEAKENING AS IT ARRIVES IS
VERY LOW...GIVEN THE DECENT MID-LVL FORCING ASSOCIATED. TEMPS
CONTINUE TO BE COOL ENOUGH TO SUPPORT LGT SNOW FOR THE AREA...AND
EXPECT SLR ARND 15:1 TO 18:1. THIS WILL LIKELY PRODUCE A QUICK 1 TO
2 INCHES OF SNOWFALL ACROSS MOST OF THE CWFA. BY 12-15Z TUE...THE
BULK OF THE WAVE/SNOW WILL BE PUSHING EAST AND COMING TO AN END.
THEN FOR TUE...500MB TROUGH AXIS ARRIVES AS AN ARCTIC AIRMASS
CONTINUES TO PUSH SOUTH FROM CANADA TOWARDS THE UPPER MIDWEST TUE
AFTN. CURRENTLY EXPECT HIGHS TUE TO HOLD IN THE TEENS/LOW
20S...HOWEVER BY TUE NGT THE BOUNDARY WILL BE PUSHING ACROSS THE
FORECAST AREA AND TEMPS WILL BE DROPPING TO A FEW DEGREES BELOW
ZERO.
CONFIDENCE...HIGH.
CONFIDENCE IN SNOW ACCUMS MON EVE/OVERNIGHT...HIGH.
WEDNESDAY THROUGH SUNDAY...
ENSEMBLES AND OPERATIONAL SOLUTIONS HAVE CONTINUED TO BE IN GOOD
AGREEMENT WITH THE ARRIVAL OF YET ANOTHER ARCTIC AIRMASS. BY WED THE
500MB TROUGH AXIS WILL BE OVERHEAD. CURRENT PROGS INDICATE TEMPS IN
MID-LVLS WILL HOVER ARND -20 TO -25 DEG C. WHEN APPLYING THIS
TOWARDS LOCAL CLIMATE WHICH LIKELY YIELD HIGH TEMPS WED IN THE
SINGLE DIGITS ABOVE ZERO TO POSSIBLY THE LOW TEENS. SFC RIDGE WILL
BE SLIDING OVER THE AREA AS WELL...WHICH SHOULD LIMIT HOW MUCH LOWER
WIND CHILL VALUES WILL BE WED. THEN FOR WED NGT...FLOW GRADUALLY
TURNS WESTERLY IN THE LLVLS. A WEAK SHORTWAVE IS PROGGED TO CLIP THE
NORTHERN GREAT LAKES REGION...HOWEVER EXPECT GENERALLY DRY WEATHER
FOR THE FORECAST AREA WED/WED NGT.
FOR THE REMAINDER OF THE EXTENDED PERIODS...ENSEMBLES REMAIN IN
DECENT AGREEMENT WITH YET ANOTHER SFC RIDGE SLIDING SOUTHEAST FROM
CENTRAL CANADA TOWARDS THE PLAINS AND STRETCHING EAST TO THE WESTERN
GREAT LAKES THUR. THIS SHOULD HELP TO MAINTAIN UNSEASONABLY COLD
CONDS FOR THE FORECAST AREA...WITH TEMPS STRUGGLING TO WARM BEYOND
THE LOW/MID TEENS THUR AFTN.
STRONG VORTEX BEGINS TO LIFT NORTHEAST THUR NGT/FRI...WITH SOME
MODERATION TO TEMPS POISED FOR THE END OF THE WEEK INTO THE FIRST
HALF OF NEXT WEEKEND. ALTHOUGH THIS IS RELATIVE...AS TEMPS WILL
CONTINUE TO BE UNSEASONABLY COOL IN THE TEENS/LOW 20S. GUIDANCE IS
SUGGESTING THE SOUTHERN STREAM WILL BECOME ACTIVE YET AGAIN IN THE
LATER PERIODS...AND INDICATES THE PRECIP WILL REMAIN SOUTH OF THE
CWFA. ALTHOUGH COULD SEE SOME ADJUSTMENTS TO THE PLACEMENT OF EACH
SOUTHERN STREAM WAVE.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NONE
//DISCUSSION...UPDATED 06Z...
QUIET WEATHER DAY ON TAP THIS TAF PERIOD WITH VFR CONDITIONS AND WNW
WINDS THROUGHOUT THE PERIOD. A FEW GUSTS INTO THE HIGH TEENS TO
AROUND 20 KT ARE POSSIBLE DURING THE AFTERNOON AND EVENING
SUNDAY...THEN SHOULD TAPER MID TO LATE IN THE EVENING. THE NEXT
CHANCE FOR WEATHER IMPACTS APPEARS TO BE MONDAY NIGHT INTO TUESDAY
WHEN SNOW WILL MOVE ACROSS THE AREA.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR LIKELY DURING DAYTIME THEN LIGHT SNOW BECOMING
LIKELY MONDAY NIGHT WITH MVFR LIKELY...IFR POSSIBLE.
TUESDAY...CHANCE OF LIGHT SNOW EARLY AM. THEN VFR LIKELY.
WEDNESDAY THROUGH FRIDAY...VFR LIKELY.
RC
&&
.MARINE...
148 PM CST
LOW PRESSURE CENTERED NEAR JAMES BAY THIS AFTERNOON CONTINUES TO
PRODUCE WINDS OF 25 TO 30 KT ACROSS THE LAKE THIS AFTERNOON. THIS
LOW WILL GRADUALLY WEAKEN THROUGH THE REMAINDER OF THE WEEKEND.
HOWEVER...WESTERLY WINDS WILL CONTINUE IN THE 20 TO 30 KT RANGE
SUNDAY INTO MONDAY AS THE SURFACE GRADIENT REMAINS ELEVATED IN
ADVANCE OF A BROAD RIDGE OF SURFACE HIGH PRESSURE EXTENDING FROM THE
NORTHERN PLAINS TO THE OHIO VALLEY.
THE NEXT POTENTIAL HEADLINE WORTHY WIND EVENT WILL BE AROUND THE
MIDDLE OF NEXT WEEK. A FEW CLIPPER TYPE SYSTEMS ARE EXPECTED TO DROP
SOUTHEASTWARD ACROSS THE LAKES REGION DURING THIS PERIOD. OF THESE
NUMEROUS CLIPPER SYSTEMS...IT APPEARS THAT A POTENT ONE WILL
DROP ACROSS THE REGION WEDNESDAY NIGHT. THIS SYSTEM COULD PRODUCE A
PERIOD OF SOUTHWESTERLY GALES ON WEDNESDAY...FOLLOWED BY A PERIOD OF
POTENTIALLY HIGH END NORTHWESTERLY GALES IN ITS WAKE WEDNESDAY NIGHT
INTO THURSDAY. WITH ANOTHER DEEP ARCTIC SURGE OF COLD AIR EXPECTED
IN THE WAKE OF THIS SECOND CLIPPER...THERE WILL ALSO LIKELY BE
SIGNIFICANT FREEZING SPRAY IN CONJUNCTION WITH THE STRONG
NORTHWESTERLY GALES WEDNESDAY NIGHT INTO THURSDAY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1140 PM CST Sat Feb 22 2014
.DISCUSSION...
ISSUED 636 PM CST Sat Feb 22 2014
Made a few quick updates to the forecast to better reflect current
trends, mainly to tighten the POP gradient across central Illinois.
Radar continues to indicate the narrow band of precipitation
remaining focused along a Jacksonville to Danville line. Latest
run of the HRRR shows very little movement of the band until 04z
when it slowly sinks southeastward. As a result, have increased
POPs to categorical within the band itself and have removed all
mention of POPs further north in the Peoria area and further south
from Effingham southward. With surface temps in the middle to
upper 30s initially, precip has started as rain at most sites, but
is quickly transitioning to wet snow as evaporative cooling takes
place within the surface-based layer. Based on gradual eastward
shift of precip area and current temps above freezing, think snow
accumulations will remain light. 1 to 2 inches still look reasonable
across the E/NE KILX CWA, mainly from Decatur northeastward
through Champaign to Danville, with little or no accumulation
elsewhere around the area. Zone update has already been issued.
Barnes
&&
.AVIATION...
ISSUED 1140 PM CST Sat Feb 22 2014
Persistent band of snow has now shifted southeast of the KILX
terminals, so VFR conditions are expected through the entire 06z
TAF period. Winds will remain northerly at less than 10kt tonight
through Sunday afternoon before backing to northwesterly by
evening. Only mid/upper-level clouds are expected as weak
disturbances embedded within broad northwesterly flow aloft pass
through the area over the next 24 hours.
Barnes
&&
.PREV DISCUSSION...
ISSUED 300 PM CST Sat Feb 22 2014
Light snow or flurries will return this afternoon and this evening
across most of the area. Measurable snow will be mainly confined
to areas east of I-55, with an inch or two possible closer to
Indiana east of Champaign to Mattoon. The next chance of snow
beyond that appears to be late Monday and Monday night north of
Lincoln to Champaign as the next shortwave moves across N IL.
Dry conditions are expected the remainder of the forecast, with a
dry cold frontal passage Wed night ushering in reinforcing cold
air. Below normal temperatures will prevail for much of this 7-day
forecast.
SHORT TERM...Tonight through Monday.
A band of mid-level frontogenesis north of the stationary front
along I-70 will create some lift that will be enhanced by steep
mid-level lapse rates. That should give the virga a boost in
saturating the lower levels. Flurries already started at PIA
around 2 pm after several hours of virga. Satellite pics show a
baroclinic leaf developing ahead of the weak low pressure over
western Missouri. That low is projected to slide east along the
boundary, which should further enhance the thermo-dynamic forcing.
Meso-scale bands of precip are being advertised by the HRRR and
NMM-east. Light snow will be north of Mattoon to Paris with some
rain or rain-snow mix south of there. We could see an inch or two
of snow where the band of snow rotates and lingers across our
east-central counties...bounded by a line from Decatur to
Hoopeston in the north and Taylorville to Mattoon to Paris in the
south. Even in this late hour, many differences exist with the
placement and intensity of any meso-scale bands of precip late
this afternoon and evening. The GFS and Canadian GEM are more
aggressive with snow, while the NAM is the weakest and the ECMWF
is in the middle. We increased PoPs to categorical and likely in
areas with an inch or more snow possible, with high chance
bordering that. Accums are a tough call with this much dry air to
overcome, but forcing looks strong enough for a short duration to
get some light accumulation.
Precip should progress eastward after midnight, and come to an end
for our counties by 3 am. Colder air will begin to advance into C
IL with the surface high, which should help lows across the north
drop into the teens. Clouds will temper the cool-down, as southern
areas remain in the low 30s.
The 12z Canadian has increased potential for snow or rn/sn as a
shortwave advances east, just north of the stationary front. The
ECMWF is also showing some forcing across our southern counties,
but lower RH and no precip. After coord with offices to the south,
we decided to just add sprinkles and flurries for now on Sunday.
Mostly clear skies for much of Sunday night will provide better
radiational cooling conditions, and lows will respond by dropping
into the single digits north of Peoria.
Monday afternoon and evening will see a 125kt jet at 250mb help
push a shortwave across northern IL. Light snow will develop
mainly north of a line from Rushville to Champaign...with a
dusting along the line to as much as an inch from Galesburg to
El Paso. The NAM is the main outlier with this period of snow,
with much less forcing and farther south than the
GFS/ECMWF/Canadian. We went with consensus and increased PoPs to
likely across Knox to Woodford counties Monday eve.
LONG TERM...Tuesday through Saturday.
We are not expected any measurable precip through the extended
forecast as colder air prevails. A dry cold frontal passage on Wed
night will aid in keeping temps well below normal. Lows will dip
below zero across our northern area on Tuesday night, and get very
close to zero in the north Wed night and Thurs night. Highs will
struggle to climb out of the teens north of I-72 on Wed. Gradual
warming will develop from Thurs to Saturday, but even Saturday`s
highs will range from mid 20s north to mid 30s south, or about 10
to 15 deg below normal.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1230 AM EST SUN FEB 23 2014
.SYNOPSIS...
ISSUED AT 608 PM EST SAT FEB 22 2014
SNOW WILL BE POSSIBLE OVERNIGHT MAINLY NEAR AND SOUTH OF HIGHWAY
24. ANY MIXED PRECIPITATION WILL QUICKLY CHANGE OVER TO ALL SNOW
THIS EVENING AS COOLER AIR FILTERS IN. IT WILL LIKELY REMAIN DRY
TONIGHT OVER EXTREME NORTHERN INDIANA AND SOUTHWEST LOWER
MICHIGAN. CANADIAN HIGH PRESSURE WILL BRING COOL AND DRY
CONDITIONS ON SUNDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 421 PM EST SAT FEB 22 2014
MODELS CONTINUE TO SHOW STRONG SIGNAL FOR NARROW...SHORT DURATION
MESOSCALE SNOW THIS EVENING INTO THE OVERNIGHT HOURS. RELIED HEAVILY
ON HIRES GUIDANCE GIVEN SMALL SCALE NATURE TO THIS EVENT. PREVIOUS
SHIFT LOCKED ONTO EVENT AND ADJUSTMENTS MADE BASED ON LATEST
HRRR...RAP13 AND 12Z ARW EAST AND ARW NMM. RESULT IS A LITTLE
NORTHWARD ADJUST TO POPS AND SNOW BUT NOT BY MUCH. THE HIGHWAY 24
CORRIDOR AND SOUTH STILL APPEAR IN LINE FOR A GENERAL 1 TO 3 WITH
SMALL EMBEDDED AREA OF 2 TO 5 WITH ANY MESOBANDING THAT SETS UP.
STRONG MID LEVEL FORCING DEPICTED WITH OMEGA FIELDS IN THE 15 TO 20
UBAR/S RANGE. FGEN FORCING STILL IMPRESSIVE IN THIS SAME AREA WITH
MESOBANDING POTENTIAL SEEN ON VERTICAL CROSS SECTIONS. HIRES
GUIDANCE HAS BEEN PICKING UP ON THIS WITH SOME IMPRESSIVE LIFT AND
QPF AMOUNTS THIS EVENING BETWEEN ONE QUARTER AND ONE HALF INCH NEAR
AND SOUTH OF HIGHWAY 24. INITIAL CONCERNS WITH DRIER LOW LEVEL AIR
AND MOISTURE GOING INTO SATURATION CONTINUE. LITTLE PCPN HAS BEEN NOTED
THROUGH 19Z UPSTREAM WHERE SOME OF THE HIRES GUIDANCE HAS BEEN
SHOWING UP TO A TENTH OF AN INCH LIQUID ALREADY. RADAR MOSAIC HAS
SHOWN MID LEVEL RETURNS BUT FEW IF ANY SURFACE REPORTS. SATELLITE
SHOWS COOLING CLOUD TOPS AND A SHORT WAVE APPROACHING. COUPLED JET
STREAKS EXPECTED OVER AREA BY 00Z AND AS THESE FEATURES COME
TOGETHER EXPECT PCPN TO BEGIN SATURATING AND REACHING GROUND.
HAVE LEANED AWAY FROM THE HIGHER END QPF GIVEN POOR EARLY
PERFORMANCE UPSTREAM AND FOCUSED MORE ON A BLEND OF THE MID RANGE
VALUES. 16Z HRRR DEPICTION OF SNOW DEVELOPING FROM NEAR KLAF TO KFWA
BY 23Z REASONABLE AND SIMILAR TO LATEST RAP13. BRIEF PERIOD OF RAIN
AT ONSET POSSIBLE WITH LOW LEVEL THERMAL FIELDS ABOVE FREEZING.
HOWEVER...EVAPORATIVE COOLING EXPECTED TO QUICKLY COOL VERY SHALLOW
WARM LAYER AND QUICKLY TRANSITION TO ALL SNOW. DISCUSSION WITH WPC
AGREED WITH A GENERAL 1 TO 2 INCHES AND SMALLER AREA OF 2 TO 4
POSSIBLE WITH EXACT LOCATION REMAINING A BIT UNCERTAIN GIVEN SMALL
SCALE BUT INTENSE FORCING. WOULD NOT RULE OUT A FEW 5 INCH REPORTS
BUT WOULD EXPECT THIS TO BE VERY ISOLATED IN A NARROW BAND. TIMING
SUGGEST HEAVIEST SNOW BETWEEN ABOUT 00Z AND 05Z WITH QUICK ENDING
FROM WEST TO EAST. EXPECT A RATHER SHARP GRADIENT ON NORTHERN
PERIPHERY OF SNOW AND THIS WILL LIKELY NEED SOME ADJUSTMENT THIS
EVENING ONCE SNOW DEVELOPS AND TRENDS ASSESSED.
DRIER AND COOLER AIR MOVES IN LATE TONIGHT AND FOR SUNDAY.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 421 PM EST SAT FEB 22 2014
A DOMINANT UPSTREAM RIDGE WILL NOT START TO BREAK DOWN UNTIL LATE
THIS WEEK ALLOWING FOR A VERY COLD UPCOMING PERIOD WITH FLOW COMING
FROM THE CANADIAN INTERIOR. OVERALL...THE GFS AND ECMWF WERE
STRUGGLING WITH RUN TO RUN CONSISTENCY IN HANDLING THE TIMING AND
EXTEND OF SUCCESSIVE SURGES OF ARCTIC AIR...ESPECIALLY LATE THIS
UPCOMING WEEK. HOWEVER...THE CANADIAN GEM AND ITS ENSEMBLES HAVE
KEPT A VERY CONSISTENT SIGNAL FOR THE PAST SEVERAL RUNS HANDLING THE
COLD AIR WITH THE ENSEMBLE MEDIAN STAYING 20 TO 25 DEGREES BELOW
NORMAL FROM TUESDAY THROUGH SUNDAY. FOR THIS PACKAGE...GIVEN THIS
VARIABILITY AMONG THE ECMWF AND GFS...BUT STRONG SIGNAL FROM THE
CANADIAN GEM AND ANALOGS...KEPT TEMPERATURES COLD WITH VIRTUALLY NO
CHANGES FROM THE PREVIOUS FORECAST FOR WEDNESDAY THROUGH THE END OF
THE WEEK. THE ECMWF WAS COLDER AGAIN WITH THE 12Z RUN...WITH 850 MB
TEMPS NEAR -27C SATURDAY. GIVEN THE CLIMATOLOGICAL EXTREMES OF THESE
TEMPERATURES...KEPT HIGHS MAINLY IN THE TEENS WEDNESDAY THROUGH
SATURDAY WITH LOWS IN THE SINGLE DIGITS ABOVE ZERO...TO A LITTLE
BELOW ZERO THURSDAY NIGHT. THESE HIGHS AND LOWS ARE WELL IN LINE
WITH THE LATEST CANADIAN GEM/EPS GRAMS. OTHERWISE...KEPT THE
FORECAST DRY EXCEPT FOR A CHANCE FOR SNOW MONDAY NIGHT WITH THE
ARRIVAL OF A WEAK UPPER LEVEL TROF. THE ECMWF...ALTHOUGH STRUGGLING
LATE IN THE FORECAST PERIOD...HAS A GOOD HANDLE ON A WEAK UPSTREAM
SHORTWAVE THAT SHOULD ARRIVE MONDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1230 AM EST SUN FEB 23 2014
ACTIVE FRONTAL BOUNDARY REMAINS JUST SOUTH OF KFWA AND LITTLE
NORTHWARD MOVEMENT IS EXPECTED THROUGH THE REST OF THE NIGHT. IN
FACT...RECENT RADAR RETURNS ARE BEGINNING TO WEAKEN AND EXPECT
SNOWFALL TO CONTINUE WINDING DOWN OVER THE NEXT FEW HOURS AS
PARENT JET FORCING LIFTS NORTHEAST. THEREFORE EXPECT VFR
CONDITIONS TO CONTINUE THROUGH MUCH OF THE PERIOD AS CANADIAN
RIDGE AXIS BUILDS INTO THE OHIO VALLEY. OUTSIDE CHANCE OF A FEW
STRATOCU DURING THE DAY BUT DRY LOW LEVELS WILL BE DIFFICULT TO
OVERCOME AND MAY BE ABLE TO REMOVE MENTION ALTOGETHER WITH THE 12Z
ISSUANCE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...KG
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1114 AM CST SUN FEB 23 2014
.UPDATE...
ISSUED AT 516 AM CST SUN FEB 23 2014
RADAR TRENDS THE PAST SEVERAL HOURS SHOW A SLOW WEAKENING OF
RETURNS ACROSS NORTHERN MISSOURI. KSTJ AND KCNK HAVE BEEN THE ONLY
OBSERVATION SITES THAT HAVE REPORTED ANY SNOW. RAP MODEL TRENDS
CONTINUE TO SHOW A SUBSTANTIAL DRY LAYER BELOW 850MB IN THE
FORECAST SOUNDINGS.
A COUPLE OF FLURRIES CANNOT BE RULED OUT SOUTH OF A KTVK TO KMQB
LINE EARLY THIS MORNING. BASED ON RADAR TRENDS...A DRY FORECAST
STILL LOOKS REASONABLE.
&&
.SYNOPSIS...
ISSUED AT 300 AM CST SUN FEB 23 2014
06Z SFC ANALYSIS HAS A FRONTAL BOUNDARY FROM THE OHIO VALLEY INTO
THE SOUTHERN PLAINS. A WEAK TROF RAN THROUGH THE GREAT LAKES WHILE
HIGH PRESSURE WAS OVER THE NORTHERN PLAINS. DEW POINTS WERE IN THE
SINGLE DIGITS AND TEENS FROM THE NORTHERN PLAINS INTO THE UPPER
MIDWEST WITH 20S AND 30S FROM THE SOUTHERN GREAT LAKES AND OHIO
VALLEY INTO THE REMAINDER OF THE PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CST SUN FEB 23 2014
THE NEXT WEAK DISTURBANCE ALOFT IS MOVING FROM THE PLAINS INTO THE
LOWER MISSOURI VALLEY. ALTHOUGH RADAR RETURNS LOOK IMPRESSIVE...NO
REPORTING STATION INDICATES PRECIPITATION REACHING THE GROUND.
FORECAST SOUNDINGS INDICATE A VERY DRY ATMOSPHERE WILL REMAIN IN
PLACE ACROSS THE AREA TODAY AND TONIGHT AS HIGH PRESSURE SLOWLY
BUILDS INTO THE MIDWEST.
AT THE VERY WORST A FEW FLURRIES MIGHT BE SEEN ACROSS THE EXTREME
SOUTHERN AREAS EARLY THIS MORNING. OTHERWISE DRY CONDITIONS WILL BE
SEEN ACROSS THE AREA TODAY AND TONIGHT. TEMPERATURES WILL AVERAGE
BELOW NORMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 300 AM CST SUN FEB 23 2014
CONTINUED VERY COLD WITH NEAR RECORD LOW TEMPERATURES WITH LIGHT
SNOW LIKELY MANY AREAS ON MONDAY.
OVERVIEW...LITTLE SENSIBLE WEATHER ISSUES BESIDES LIGHT SNOW AND
FLURRIES WITH NEXT INFUSION OF ARCTIC AIR ARRIVING ON MONDAY. LOW
LEVEL THERMAL AND MOISTURE FIELDS SUGGESTS A 70/30 MIX OF HI-RES
ECMWF WITH GFS. DEEP NW CYCLONIC FLOW KEEPS ARCTIC AIR IN PLACE
DAYS 2 THROUGH 7 WITH LITTLE SENSIBLE WEATHER ISSUES. LOW LEVEL
THERMAL FIELDS SUPPORT NEAR RECORD TO RECORD LOW MINS WEDNESDAY AM
AND POSSIBLY AGAIN TOWARD FRIDAY DEPENDING ON HIGH PRESSURE TRACKS.
MONDAY...UPPED POPS TO LIKELY...MOSTLY MONDAY EVENING WITH CENTRAL
1/3 OR MORE OF FORECAST AREA TO RECEIVE 2 TO 3 HOURS OF LIGHT SNOW
AS WEAK DISTURBANCE PASSES. LOCAL TOOLS AND TECHNIQUES SUGGEST .5
TO LOCALLY NEAR 1 INCH OF A POWDERY DRY SNOW WITH LWE OF 20:1 OR MORE.
FAR NORTH AND SOUTH SECTIONS MAY RECEIVE MORE OF A DUSTING OF FLURRIES.
TEMPERATURES IN THE TEENS NORTH TO MID/UPPER 20S FAR SOUTH SECTIONS.
MONDAY NIGHT...LOWS AS A CHALLENGE AS CLEARING SHOULD OCCUR AFTER
MIDNIGHT NW TO NEAR DAYBREAK SE SECTIONS. HENCE...MINS NEAR ZERO ARE
SUGGESTED TO MID TEENS SE SECTIONS. LATER SHIFTS MAY NEED TO CHANGE
THESE VALUES BY 5+ DEGREES IF CLEARING IS EARLIER OR DELAYED.
TUESDAY...MUCH COLDER AIR TO RESULT IN NEARLY STEADY TEMPERATURES
WITH NW WINDS OF 10 TO 20 MPH TO KEEP WIND CHILLS IN SINGLE DIGITS
SE TO NEGATIVE SINGLE DIGITS NW SECTIONS DESPITE FAIR SKIES. TUESDAY
NIGHT...WINDS TO BECOME NEARLY CALM TOWARD DAYBREAK WITH STRONG AND
SHALLOW INVERSION. LOWS SHOULD BE NEAR OR BREAK RECORDS AS DESCRIBED
IN CLIMATE SECTION BELOW. THIS SUPPORTS -13 TO +4 SE WITH FAVORED
LOCATIONS MAY NEED TO TRIMMED EVEN FURTHER BY 2 TO 5 DEGREES IF
SEVERAL HOURS OF CALM TO NEARLY CALM WINDS AND CLEAR SKIES OCCUR.
THIS MAY RESULT IN WIND CHILLS WELL BELOW -20 DEGREES INTO LATE
MORNING.
WEDNESDAY THROUGH SATURDAY...CONTINUED QUITE COLD AND FAIR TO MOSTLY
FAIR AND GENERALLY DRY WITH LOWS WELL BELOW NORMAL BY 15 TO 20 DEGREES.
THIS SUPPORTS HIGHS MOSTLY IN THE TEENS WITH SOME UPPER SINGLE DIGITS
POSSIBLE NORTH AND LOWS SINGLE DIGITS AND POSSIBLY WELL INTO THE NEGATIVE
SINGLE DIGITS NORTH SECTIONS. NEXT WAVE OFF CALIFORNIA MAY REQUIRE
ADDING SNOW FRIDAY NIGHT AND ESPECIALLY SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1109 AM CST SUN FEB 23 2014
A STALLED RIDGE OF HIGH PRESSURE WILL KEEP VFR CONDITIONS IN PLACE
THROUGH MONDAY MORNING. AN UPPER LEVEL DISTURBANCE WILL RACE OUT
OF THE NORTHERN ROCKIES AND THROUGH THE PLAINS TONIGHT AND MONDAY
SPREADING LIGHT SNOW OVER REGION MONDAY AFTERNOON AND EVENING
CAUSING A DETERIORATION IN FLIGHT CONDITIONS.
&&
.CLIMATE...
ISSUED AT 300 AM CST SUN FEB 23 2014
RECORD LOWS FOR FEBRUARY 26...
MOLINE.........-14 IN 1963
CEDAR RAPIDS...-08 IN 1950
DUBUQUE........-10 IN 1980
BURLINGTON.....-11 IN 1950
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...NICHOLS
AVIATION...DLF
CLIMATE...NICHOLS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
528 AM CST SUN FEB 23 2014
.UPDATE...
ISSUED AT 516 AM CST SUN FEB 23 2014
RADAR TRENDS THE PAST SEVERAL HOURS SHOW A SLOW WEAKENING OF
RETURNS ACROSS NORTHERN MISSOURI. KSTJ AND KCNK HAVE BEEN THE ONLY
OBSERVATION SITES THAT HAVE REPORTED ANY SNOW. RAP MODEL TRENDS
CONTINUE TO SHOW A SUBSTANTIAL DRY LAYER BELOW 850MB IN THE
FORECAST SOUNDINGS.
A COUPLE OF FLURRIES CANNOT BE RULED OUT SOUTH OF A KTVK TO KMQB
LINE EARLY THIS MORNING. BASED ON RADAR TRENDS...A DRY FORECAST
STILL LOOKS REASONABLE.
&&
.SYNOPSIS...
ISSUED AT 300 AM CST SUN FEB 23 2014
06Z SFC ANALYSIS HAS A FRONTAL BOUNDARY FROM THE OHIO VALLEY INTO
THE SOUTHERN PLAINS. A WEAK TROF RAN THROUGH THE GREAT LAKES WHILE
HIGH PRESSURE WAS OVER THE NORTHERN PLAINS. DEW POINTS WERE IN THE
SINGLE DIGITS AND TEENS FROM THE NORTHERN PLAINS INTO THE UPPER
MIDWEST WITH 20S AND 30S FROM THE SOUTHERN GREAT LAKES AND OHIO
VALLEY INTO THE REMAINDER OF THE PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CST SUN FEB 23 2014
THE NEXT WEAK DISTURBANCE ALOFT IS MOVING FROM THE PLAINS INTO THE
LOWER MISSOURI VALLEY. ALTHOUGH RADAR RETURNS LOOK IMPRESSIVE...NO
REPORTING STATION INDICATES PRECIPITATION REACHING THE GROUND.
FORECAST SOUNDINGS INDICATE A VERY DRY ATMOSPHERE WILL REMAIN IN
PLACE ACROSS THE AREA TODAY AND TONIGHT AS HIGH PRESSURE SLOWLY
BUILDS INTO THE MIDWEST.
AT THE VERY WORST A FEW FLURRIES MIGHT BE SEEN ACROSS THE EXTREME
SOUTHERN AREAS EARLY THIS MORNING. OTHERWISE DRY CONDITIONS WILL BE
SEEN ACROSS THE AREA TODAY AND TONIGHT. TEMPERATURES WILL AVERAGE
BELOW NORMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 300 AM CST SUN FEB 23 2014
CONTINUED VERY COLD WITH NEAR RECORD LOW TEMPERATURES WITH LIGHT
SNOW LIKELY MANY AREAS ON MONDAY.
OVERVIEW...LITTLE SENSIBLE WEATHER ISSUES BESIDES LIGHT SNOW AND
FLURRIES WITH NEXT INFUSION OF ARCTIC AIR ARRIVING ON MONDAY. LOW
LEVEL THERMAL AND MOISTURE FIELDS SUGGESTS A 70/30 MIX OF HI-RES
ECMWF WITH GFS. DEEP NW CYCLONIC FLOW KEEPS ARCTIC AIR IN PLACE
DAYS 2 THROUGH 7 WITH LITTLE SENSIBLE WEATHER ISSUES. LOW LEVEL
THERMAL FIELDS SUPPORT NEAR RECORD TO RECORD LOW MINS WEDNESDAY AM
AND POSSIBLY AGAIN TOWARD FRIDAY DEPENDING ON HIGH PRESSURE TRACKS.
MONDAY...UPPED POPS TO LIKELY...MOSTLY MONDAY EVENING WITH CENTRAL
1/3 OR MORE OF FORECAST AREA TO RECEIVE 2 TO 3 HOURS OF LIGHT SNOW
AS WEAK DISTURBANCE PASSES. LOCAL TOOLS AND TECHNIQUES SUGGEST .5
TO LOCALLY NEAR 1 INCH OF A POWDERY DRY SNOW WITH LWE OF 20:1 OR MORE.
FAR NORTH AND SOUTH SECTIONS MAY RECEIVE MORE OF A DUSTING OF FLURRIES.
TEMPERATURES IN THE TEENS NORTH TO MID/UPPER 20S FAR SOUTH SECTIONS.
MONDAY NIGHT...LOWS AS A CHALLENGE AS CLEARING SHOULD OCCUR AFTER
MIDNIGHT NW TO NEAR DAYBREAK SE SECTIONS. HENCE...MINS NEAR ZERO ARE
SUGGESTED TO MID TEENS SE SECTIONS. LATER SHIFTS MAY NEED TO CHANGE
THESE VALUES BY 5+ DEGREES IF CLEARING IS EARLIER OR DELAYED.
TUESDAY...MUCH COLDER AIR TO RESULT IN NEARLY STEADY TEMPERATURES
WITH NW WINDS OF 10 TO 20 MPH TO KEEP WIND CHILLS IN SINGLE DIGITS
SE TO NEGATIVE SINGLE DIGITS NW SECTIONS DESPITE FAIR SKIES. TUESDAY
NIGHT...WINDS TO BECOME NEARLY CALM TOWARD DAYBREAK WITH STRONG AND
SHALLOW INVERSION. LOWS SHOULD BE NEAR OR BREAK RECORDS AS DESCRIBED
IN CLIMATE SECTION BELOW. THIS SUPPORTS -13 TO +4 SE WITH FAVORED
LOCATIONS MAY NEED TO TRIMMED EVEN FURTHER BY 2 TO 5 DEGREES IF
SEVERAL HOURS OF CALM TO NEARLY CALM WINDS AND CLEAR SKIES OCCUR.
THIS MAY RESULT IN WIND CHILLS WELL BELOW -20 DEGREES INTO LATE
MORNING.
WEDNESDAY THROUGH SATURDAY...CONTINUED QUITE COLD AND FAIR TO MOSTLY
FAIR AND GENERALLY DRY WITH LOWS WELL BELOW NORMAL BY 15 TO 20 DEGREES.
THIS SUPPORTS HIGHS MOSTLY IN THE TEENS WITH SOME UPPER SINGLE DIGITS
POSSIBLE NORTH AND LOWS SINGLE DIGITS AND POSSIBLY WELL INTO THE NEGATIVE
SINGLE DIGITS NORTH SECTIONS. NEXT WAVE OFF CALIFORNIA MAY REQUIRE
ADDING SNOW FRIDAY NIGHT AND ESPECIALLY SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 516 AM CST SUN FEB 23 2014
VFR CONDITIONS WILL BE SEEN THROUGH 12Z/24 AS A WEAK DISTURBANCE
MOVES ACROSS MISSOURI AND HIGH PRESSURE BUILDS SOUTH FROM CANADA.
&&
.CLIMATE...
ISSUED AT 300 AM CST SUN FEB 23 2014
RECORD LOWS FOR FEBRUARY 26...
MOLINE.........-14 IN 1963
CEDAR RAPIDS...-08 IN 1950
DUBUQUE........-10 IN 1980
BURLINGTON.....-11 IN 1950
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...NICHOLS
AVIATION...08
CLIMATE...NICHOLS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
745 PM MST MON FEB 24 2014
.UPDATE...
ISSUED AT 742 PM MST MON FEB 24 2014
JUST ISSUED AN UPDATE TO LOWER MINS WITH SOME LOCATIONS ALREADY
GETTING CLOSE TO THE FORECAST. COLD ADVECTION MORE AGGRESSIVE THAN WHAT
THE CURRENT MODEL OUTPUT IS SAYING. USING CURRENT READINGS AND THE
LATEST HRRR TO MAKE THE ADJUSTMENT.
UPDATE ISSUED AT 556 PM MST MON FEB 24 2014
JUST COMPLETED AN UPDATE. MAIN CHANGE WAS THE WINDS. COLD FRONT
GOING THROUGH THE AREA AT THIS TIME WITH STRONG 3 HOUR PRESSURE
RISES AND TIGHT GRADIENT BEHIND IT. SO WINDS WERE INCREASED INTO
THE BREEZY TO WINDY CATEGORY. BY MID EVENING THE WINDS SHOULD
DECREASE WITH LIGHTER WINDS AFTER MIDNIGHT. MINOR ADJUSTMENT WAS
ALSO MADE TO THE SKY COVER TO INCREASE IT A LITTLE FASTER THAN
WHAT THE GRIDS DEPICTED.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 215 PM MST MON FEB 24 2014
MAIN FOCUS FOR THE SHORT TERM TODAY IS THE TEMPERATURES AND
PRECIPITATION CHANCES OVERNIGHT AND TOMORROW. TEMPERATURES TODAY
HAVE RISEN INTO THE MID 30S OVER THE NORTHEAST PORTIONS OF THE CWA
WHILE FURTHER WEST TEMPERATURES HAVE RISEN INTO THE LOW 60S IN
FLAGLER COLORADO ASSOCIATED WITH A WARM FRONT IN EASTERN COLORADO. THE
NORTHEAST PORTION OF THE CWA WILL REMAIN ON THE COOL SIDE WITH
HIGHS IN THE LOW 20S WHILE THE WEST/SOUTHWEST PORTIONS OF THE CWA
COOL DOWN SIGNIFICANTLY FROM TODAY TO TOMORROW WITH HIGHS
STRUGGLING TO REACH 30 AS A BACK DOOR COLD FRONT MOVES THROUGH
OVERNIGHT. BEHIND THE COLD FRONT...CLOUD COVER WILL INCREASE AND
THERE WILL BE A CHANCE FOR SNOW FLURRIES MOVING IN FROM THE
NORTHEAST. FOR TEMPERATURES AND PRECIPITATION...WENT WITH A BLEND
OF NAM...SREF...AND HRRR. BUFKIT SOUNDINGS BECOME SATURATED
SLIGHTLY ABOVE THE SURFACE AND BECOME DRIER TOWARDS THE SURFACE.
SINCE THE TEMPERATURE PROFILE IS BELOW ZERO AND THE COLUMN IS
FAIRLY SATURATED...CHANGED PRECIPITATION TYPE TO FLURRIES FROM
FREEZING FOG...FROM THE PREVIOUS FORECAST...SINCE THIS SEEMS MORE
LIKELY. FLURRIES SHOULD TAPER OFF AROUND 12Z AS SURFACE HIGH
PRESSURE SLIDES INTO THE CWA.
THE PERIOD OF NO PRECIPITATION TOMORROW MORNING WILL BE RATHER
SHORT-LIVED AS THE NEXT COLD FRONT AND SHORT WAVE TROUGH MOVE
INTO THE CWA. 700MB FRONTOGENESIS SHOWS A DECENT AREA OF LIFT
TRAVERSING THE NORTHERN AND WESTERN PORTIONS OF THE CWA. INCLUDED
CHANCE POPS FOR SNOW STARTING AT 17Z IN EXTREME NORTHERN PORTIONS
OF THE CWA FROM NORTHERN YUMA COUNTY EAST TO NORTHERN RED WILLOW
COUNTY. AS THE AREA OF FRONTOGENESIS MOVES FROM NORTHEAST TO THE
SOUTH-SOUTHWEST...THE CHANCE OF SNOW WILL CONTINUE INTO TUESDAY
NIGHT. ACCUMULATIONS WILL BE AROUND A TENTH OF INCH SOUTH OF
HIGHWAY 36 TO AN INCH OVER AREAS NORTH OF HIGHWAY 36.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 305 AM MST MON FEB 24 2014
TUESDAY EVENING AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE AREA.
AHEAD OF THE TROUGH AXIS THE RIGHT ENTRANCE OF THE 500-300 MB JET
STREAK AND 700-300MB FRONTOGENESIS WILL MOVE OVER THE AREA. HAVE
NOTICED THE FRONTOGENESIS HAS STRENGTHENED IN THE LATEST MODEL RUNS
GIVING ADDED CONFIDENCE THAT SNOWFALL WILL DEVELOP. SOUNDINGS
ACROSS THE AREA CONTINUE TO SHOW THE DENDRITIC LAYER ONLY A FEW
THOUSAND FEET OFF THE GROUND. WITH A DEEPLY SATURATED ENVIRONMENT
AND THE DENDRITIC ZONE NEAR THE SURFACE...CONTINUE TO THINK THE
LARGE SCALE LIFT AHEAD OF THE TROUGH WILL ALLOW SNOWFALL TO
DEVELOP. DUE TO THE LOW DEW POINTS IN THE TEENS AM THINKING THE
SNOW WILL BE FAIRLY DRY. DUE TO THE QUICK PASSAGE OF THE TROUGH AM
THINKING SNOW ACCUMULATIONS WILL BE FAIRLY SMALL. AFTER MIDNIGHT
THE TROUGH WILL BE SOUTHEAST OF THE AREA. BEHIND THE TROUGH SKIES
WILL CLEAR AND WINDS WILL BECOME LIGHT...ALLOWING TEMPERATURES TO
FALL NEAR THE DEW POINT.
WEDNESDAY AND WEDNESDAY NIGHT A WARM FRONT WILL MOVE THROUGH THE
AREA DURING THE MORNING ALLOWING TEMPERATURES WARM TO NEAR
NORMAL. OVERNIGHT A COLD FRONT WILL MOVE INTO THE NORTHEAST PART OF
THE AREA...COOLING TEMPERATURES TO AROUND 10 DEGREES BEHIND IT.
THURSDAY THROUGH MONDAY WILL BE DOMINATED BY CHANCES FOR SNOW AS
SEVERAL UPPER LEVEL SHORT WAVE TROUGHS MOVE ACROSS THE AREA. THE
FIRST TROUGH WILL MOVE THROUGH THURSDAY NIGHT...WITH THE MAJORITY OF
THE LIFT FROM THE TROUGH REMAINING SOUTH OF THE AREA...HOWEVER
MODELS SHOW A LARGE PLUME OF 1000-500MB MOISTURE MOVING SOUTHEAST
OVER THE AREA AS THE SMALLER SCALE TROUGH MOVES THROUGH. FRIDAY
THERE MAY BE SOME LINGERING SNOW IN THE MORNING AS THE TROUGH MOVES
OUT OF THE AREA. FRIDAY NIGHT THROUGH THE WEEKEND THE LONG WAVE
TROUGH OVER THE NORTHERN PART OF THE COUNTRY CONTINUES TO DIRECT
1000-500MB MOISTURE OVER THE AREA...ALLOWING CHANCES FOR SNOW TO
CONTINUE THROUGH THE WEEKEND AS ANOTHER STRONGER TROUGH MOVES IN
FROM THE WEST. THIS STRONGER TROUGH WILL MOVE OVER THE AREA
SUNDAY. BY MONDAY THE TROUGH WILL BE EAST OF THE AREA CAUSING
CHANCES FOR SNOW TO COME TO AN END.
TEMPERATURES FOR THE PERIOD WILL BE NEAR TO BELOW NORMAL. THURSDAY
AND FRIDAY THE COLD FRONT WILL WOBBLE EAST TO WEST ACROSS THE AREA.
FRIDAY NIGHT THE FRONT WILL BE PUSHED EAST AS THE LONG WAVE TROUGH
OVER THE NORTHERN PLAINS MOVES SOUTHWARD. BEHIND THE FRONT MUCH
COOLER AIR WILL MOVE INTO THE AREA...WITH TEMPERATURES 10-20 DEGREES
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 443 PM MST MON FEB 24 2014
COMPLICATED SET OF TAFS DUE TO MULTIPLE FRONTAL PASSAGES AND
VARIABLE LOWER LEVEL CLOUD COVER. INITIAL COLD FRONT WILL GO
THROUGH AT THE BEGINNING OF THIS PERIOD. WINDS WILL BECOME GUSTY
FOR A SHORT PERIOD OF TIME WITH MVFR CEILINGS FOLLOWING VERY CLOSE
BEHIND THE FRONT. BY LATE EVENING THE GUSTINESS WILL DECREASE WITH
MVFR OR JUST ABOVE MVFR CEILINGS EXPECTED. THIS LASTS UNTIL THE
NEXT FROPA WHICH OCCURS IN THE MIDDLE OF THE DAY.
AT THAT TIME THE WINDS WILL BECOME GUSTY ONCE AGAIN AND CONTINUE
THROUGH THE END OF THIS PERIOD. KGLD WILL STAY VFR BUT KMCK WILL
BECOME MVFR WITH LIGHT SNOW EXPECTED AT THE SAME TIME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...ALW/JSL
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1225 PM MST SUN FEB 23 2014
.UPDATE...
ISSUED AT 1225 PM MST SUN FEB 23 2014
HAVE CANCELLED THE DENSE FOG ADVISORY AS VISIBILITIES HAVE IMPROVED
A BIT ABOVE 1/4 MILE.
FREEZING DRIZZLE BEING REPORTED...SEEMS TO BE CONFINED TO AREAS
WHERE SFC RH ABOVE 90-95 PERCENT SO HAVE INCLUDED. TO THE EAST
DRIER AIR AND HIGHER T/TD SPREADS ARE LIMITING FREEZING DRIZZLE
POTENTIAL. MAY SEE ANOTHER HOUR OR TWO OF FREEZING DRIZZLE BEFORE
THINGS COME TO AN END FOR TODAY. NOT MUCH HAS CHANGED WITH MAX
TEMPS TODAY IN THE MID 20S WITH LOW 30S ACROSS THE FAR SOUTHWEST
THROUGH WEST.
UPDATE ISSUED AT 1009 AM MST SUN FEB 23 2014
CONDITIONS HAVE NOT CHANGED OVER THE PAST HOUR AND A HALF AND 15Z
RUC CONTINUES TO SUPPORT WIDESPREAD LOW CLOUDS WITH FOG ACROSS THE
AREA FOR THE REST OF THE DAY. HAVE ADJUSTED GRIDS ACCORDINGLY. IN
THE GOODLAND AREA VISIBILITIES CONTINUE AROUND ONE QUARTER MILE
WITH WEB CAMS AND METARS AROUND THE AREA SHOWING VISIBILITIES
HIGHER. SINCE CONDITIONS ARE NOT EXPECTED TO CHANGE MUCH HAVE GONE
AHEAD AND ISSUED A DENSE FOG ADVISORY FOR SHERMAN COUNTY TIL 20Z.
MAY HAVE TO GO LONGER BUT WILL WAIT AND SEE ON THAT.
UPDATE ISSUED AT 850 AM MST SUN FEB 23 2014
ENTIRE FORECAST AREA ENTRENCHED IN STRATUS THIS MORNING WITH
EAST/NORTHEAST WINDS EAST OF THE CO/KS BORDER AND SOUTHEAST WINDS
ACROSS FAR EASTERN COLORADO. FOG ALSO BEING REPORTED ACROSS THE
WESTERN 2/3 OF THE AREA WITH LOCALLY DENSE FOG IN THE GOODLAND
AREA.
LATEST RUC HAS AN EXCELLENT GRASP OF THE STRATUS AND PER THE 12Z
RUN KEEPS IT OVER THE AREA FOR THE ENTIRE DAY. THE HRRR BREAKS UP
THE STRATUS OVER PARTS OF FAR EASTERN COLORADO BUT KEEPS IT OVER
THE REST OF THE AREA THROUGH THE DAY AS WELL. SHOULD THESE
SCENARIOS VERIFY TEMPERATURES WONT MOVE MUCH FROM WHERE THEY ARE
NOW AND WOULD BE SEVERAL DEGREES BELOW PREVIOUS FORECAST.
12Z NAM BOUNDARY LAYER RH ALSO HAD A GOOD HANDLE ON AREAL COVERAGE
OF STRATUS BUT BY 18Z LIFTS IT/DISSIPATES IT FROM SOUTH TO NORTH
ALLOWING MORE HEATING AND WARMER TEMPERATURES THAN THE RUC/HRRR.
FOR THE FIRST OF WHAT WILL LIKELY BE SEVERAL UPDATES HAVE TRENDED
TOWARD THE RUC/HRRR GIVEN THE EASTERLY COMPONENT TO THE WINDS ALL
DAY WHICH IS NOT REAL FAVORABLE FOR RAPID STRATUS DISSIPATION AS
THE NAM WOULD SUGGEST. HAVE LOWERED HIGH TEMPERATURES TO THE
MID/UPPER 20S ACROSS THE NORTHEAST AND EAST (WHERE LOW CLOUDS
EXPECTED LONGER) AND LOW TO MID 30S ACROSS THE FAR SOUTH THROUGH
SOUTHWEST AND WEST WHERE SOME DISSIPATION WOULD BE MOST LIKELY BUT
NOT CERTAIN AT THIS POINT.
HAVE ALSO BEEFED UP THE FOG PER LOCAL OBSERVATIONS. NONE OF THE
MODELS HANDLING THIS VERY WELL...HOPEFULLY THE 15Z RUC WILL LATCH
ON TO IT AND GIVE SOME BETTER GUIDANCE.
MORE UPDATES LIKELY TO COME LATER.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 314 AM MST SUN FEB 23 2014
UPPER FLOW WILL BE NORTHWEST THROUGH TUESDAY NIGHT. SURFACE HIGH
PRESSURE WILL BE OVER THE REGION TODAY AND TONIGHT. HIGH PRESSURE
WILL DRIFT EAST MONDAY AS LOW PRESSURE MOVES INTO EASTERN COLORADO.
A COLD FRONT WILL PUSH SOUTH MONDAY NIGHT FOLLOWED BY HIGH PRESSURE
TUESDAY AND TUESDAY NIGHT.
CURRENT RADAR SHOWING DECREASING TREND OF SNOW RETURNS OVER THE
NORTH IN THE CURRENT WINTER WEATHER ADVISORY. FRONTOGENESIS EXITS
THE AREA AND DO NOT EXPECT ANYTHING MORE THAN LIGHT SNOW THIS
MORNING AND EVEN LESS OF AN AREA THIS AFTERNOON AS DYNAMICS MOVE OUT
OF THE AREA. PLAN TO CANCEL THE WINTER WEATHER ADVISORY AT ZONES
ISSUANCE. DEWPOINT DEPRESSIONS ARE NARROWING TO LESS THAN 3 DEGREES
AND BOUNDARY LAYER RH IS PROGGED TO INCREASE TO OVER 90 PERCENT SO
HAVE INCLUDED SOME PATCHY FREEZING FOG THIS MORNING OVER ALL BUT THE
NORTHEAST FA.
FORECAST SOUNDINGS ACROSS THE FA TONIGHT INDICATE THE POSSIBILITY OF
SOME STRATUS AND FOG BUT MOISTURE IS TOO SHALLOW TO INDICATE
FREEZING DRIZZLE. PLAN TO PULL THE FREEZING DRIZZLE AND CONSIDER
SOME MENTION OF FOG OVERNIGHT INTO MONDAY MORNING. POPS WILL BE NIL
MONDAY DUE TO SUBSIDENCE AND LACK OF MOISTURE. THERE IS SOME WEAK
FORCING ACROSS THE NORTHERN ZONES MONDAY NIGHT/TUESDAY MORNING AND
MOISTURE INCREASES SO CANNOT RULE OUT A SLIGHT CHANCE OF LIGHT SNOW
OR FLURRIES. FOR TUESDAY AFTERNOON/TUESDAY NIGHT...THE GFS IS FASTER
WITH BRINGING DYNAMICS INTO THE FA THAN THE NAM. FOR NOW WILL OPT
FOR THE GFS TO STAY CONSISTENT WITH SURROUNDING OFFICES. HOWEVER DUE
TO THE TIMING DIFFERENCES WILL KEEP POPS IN THE SLIGHT CHANCE/CHANCE
RANGE.
MAX TEMPERATURES TODAY WILL BE IN THE MID 30S EXCEPT FOR WESTERN
PORTIONS OF EASTERN COLORADO WHERE SOME LOWER 40S WILL BE POSSIBLE.
TEMPERATURES WILL WARM INTO THE 40S WITH SOME MID 50S POSSIBLE IN
THE SOUTHWEST PORTION OF THE FA. TUESDAY WILL BE COLDER BEHIND THE
FRONT WITH READINGS IN THE UPPER 20S AND LOW 30S. MIN TEMPERATURES
TONIGHT WILL FALL INTO THE LOWER 20S AND INTO THE TEENS MONDAY AND
TUESDAY NIGHTS.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 236 AM MST SUN FEB 23 2014
A RETURN OF BELOW NORMAL TEMPERATURES WILL BE THE MAIN
CHARACTERISTIC OF THE EXTENDED FORECAST WITH A FEW PERIODS OF SNOW
POSSIBLE. MODELS INDICATE THAT NORTHWEST FLOW IS THE PRIMARY UPPER
LEVEL PATTERN ACROSS THE TRI-STATE AREA WITH A LARGE TROUGH OVER THE
EASTERN UNITED STATES AND A RIDGE TO THE WEST. WITH THIS PATTERN IN
PLACE...THE GATE IS OPEN FOR COLD CANADIAN AIR TO MOVE IN. THIS
PATTERN IS SIMILAR TO THE EXTENDED VERY COLD OUTBREAK OBSERVED
EARLIER THIS MONTH. THE COLD WEATHER IS NOT EXPECTED TO REACH THAT
EXTENT AGAIN BUT WELL BELOW NORMAL TEMPERATURES SHOULD BE EXPECTED.
THE FORECAST INITIALIZATION PROCEDURE PROVIDED TEMPERATURES THAT
SEEMED UNREASONABLY WARM FOR THIS TYPE OF PATTERN. THE EUROPEAN
SEEMS MOST REASONABLE AND IS SUPPORTED BY THE CANADIAN MODEL. THE
OPERATIONAL GFS HAS 850 MB TEMPS IN THE SAME BALLPARK AS THE
EUROPEAN HOWEVER MEX GUIDANCE IS 10 TO NEARLY 20 DEGREES WARMER FOR
FRIDAY AND SATURDAY. AS A RESULT...TEMPERATURES WERE NUDGED DOWN A
FEW DEGREES BUT FORECAST IS STILL PROBABLY TOO WARM.
AS FOR PRECIPITATION...THERE ARE TWO CHANCES AT WINTRY PRECIP DURING
THE EXTENDED PERIOD. FOR WEDNESDAY...THE UPPER LEVEL DISTURBANCE
THAT WILL BRING SNOW FOR TUESDAY NIGHT SHOULD BE CLEAR OF THE REGION
WITH HIGH PRESSURE BUILDING IN. ADVERTISED DRY CONDITIONS FOR
WEDNESDAY BUT A FEW FLURRIES MAY LINGER DEPENDING ON SPEED AND
MOVEMENT OF THIS SYSTEM. THE FIRST CHANCE FOR PRECIPITATION IN THE
EXTENDED FORECAST IS ANTICIPATED ON THURSDAY NIGHT INTO FRIDAY. THIS
CHANCE COMES AS A STRONGER DISTURBANCE IN THE NORTHWEST FLOW
TRANSITIONS ACROSS THE REGION. MODELS DISAGREE SOMEWHAT IN THE
PLACEMENT AND MOVEMENT OF THIS SYSTEM SO HAVE ONLY GONE SLIGHT
CHANCE TO LOW CHANCE POPS FOR THURSDAY NIGHT. DUE TO THE SPEED OF
THIS SYSTEM...AN EXTENDED PERIOD OF ACCUMULATING SNOW IS NOT
EXPECTED. IT IS ALSO POSSIBLE THIS SYSTEM MOVES SOUTH OF THE AREA
WITH NO SNOW AS THE BEST FORCING APPEARS TO REMAIN SOUTH.
THE SECOND...MORE SIGNIFICANT CHANCE OF PRECIPITATION COMES FOR NEXT
WEEKEND. THROUGH 00Z SATURDAY...THE EUROPEAN...CANADIAN AND GFS
MODELS ARE IN DECENT AGREEMENT ON A 500 MB LOW COMING INTO
CALIFORNIA. THE GFS AND EUROPEAN MODELS THEN BRING THIS SYSTEM
ACROSS THE ROCKIES ON SATURDAY AND INTO THE HIGH PLAINS SUNDAY.
THESE TYPES OF SYSTEMS ARE TYPICALLY RESPONSIBLE FOR LARGER SNOW
AMOUNTS SO WILL NEED TO MONITOR THIS SYSTEM CLOSELY. AS WITH ANY
EXTENDED FORECAST...MODELS CAN AND OFTEN DO CHANGE THEIR SOLUTIONS
THIS FAR OUT. HOWEVER...WITH BOTH MODELS PICKING UP ON IT AND
PROJECTING A SIMILAR SOLUTION...THIS MAY HAVE A LITTLE MORE WEIGHT
TO IT THAN A TYPICAL EXTENDED FORECAST STORM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1031 AM MST SUN FEB 23 2014
THIS TAF PERIOD WILL BE A MESSY ONE AS A STATIONARY FRONT TO THE
WEST OF THE TRI STATE AREA WILL KEEP CONDITIONS OVERCAST THROUGH
MOST OF THE TAF PERIOD FOR BOTH TERMINALS. PINNING DOWN
VISIBILITIES FOR KGLD AND CEILING HEIGHTS FOR BOTH TERMINALS WAS A
BIT TOUGH WITH MODEL GUIDANCE DIFFERING A LOT.
REDUCED VISIBILITIES EXPECTED TO CONTINUE AT KGLD FOR THE REST OF
THE MORNING AND INTO THE EARLY AFTERNOON HOURS BEFORE CONDITIONS
IMPROVE TO MVFR. A BRIEF BREAK WILL OCCUR AROUND SUNDOWN WITH
IMPROVED CONDITIONS BEFORE OVERCAST CONDITIONS AND REDUCED
VISIBILITIES RETURN FOR OVERNIGHT.
OVERCAST CONDITIONS AT KMCK WILL CONTINUE INTO TONIGHT. SOME AREAS
OF PATCHY FOG AROUND THE TERMINAL WILL DEVELOP...SO MENTIONED MVFR
CONDITIONS FOR VISIBILITY. CONDITIONS WILL IMPROVE TO VFR BY MID
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...FS
LONG TERM...RRH
AVIATION...MK
AREA FORECAST DISCUSSION
NWS WICHITA KS
1213 PM CST SUN FEB 23 2014
...UPDATED FOR AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 1210 PM CST SUN FEB 23 2014
STRATUS DECK THAT COVERS NORTHERN TWO-THIRDS OF KANSAS NOT BEING
HANDLED WELL BY LARGER-SCALE MODELS...THOUGH RUC AND HRRR APPEAR
TO BE CAPTURING THE SITUATION THE BEST. PERSISTENT CLOUDS WILL HAVE
IMPACT ON TEMPERATURES AND WINDS...AND HAVE ADJUSTED BOTH
DOWNWARD...FOR NORTH CENTRAL COUNTIES IN THE CWA. RUC LOW LEVEL
RH/ISENTROPIC FIELDS SUGGESTS EDGE OF CLOUD DECK TO REMAIN NORTH
AND WEST OF WICHITA/NE I-35 CORRIDOR...SO ONLY MINOR CHANGES IN
FORECAST FOR SOUTH-CENTRAL AND SOUTHEAST PORTIONS OF THE CWA.
SF
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 343 AM CST SUN FEB 23 2014
A SHORTWAVE TROUGH WAS MOVING EAST-SOUTHEAST ACROSS THE CENTRAL
ROCKIES AND INTO THE CENTRAL PLAINS EARLY THIS MORNING WHILE AN
EXPANSIVE AREA OF MID-LEVEL FRONTOGENESIS WAS PRESENT DOWNSTREAM
ALONG THE KANSAS AND NEBRASKA STATE LINE. THIS WAS SUPPORTING A LARGE
AREA OF LIGHT SNOW WHICH IS EXPECTED TO REMAIN NORTH OF THE
FORECAST AREA BEFORE DIMINISHING TOWARD THE MIDDLE OF THE DAY. AT
THE SURFACE, A COLD FRONT WAS LOCATED ACROSS THE SOUTHERN PLAINS
WHILE NORTHEAST WINDS RESULTED IN LOW LEVEL COLD AIR ADVECTION
ACROSS ALL OF THE CENTRAL PLAINS STATES. THIS WILL RESULT IN BELOW
NORMAL TEMPERATURES RETURNING TO THE FORECAST AREA TODAY.
THE INITIAL COOL DOWN WILL BE SHORT-LIVED AS SOUTHERLY FLOW RETURNS
TO THE CENTRAL PLAINS ON MONDAY ALLOWING TEMPERATURES TO RETURN TO
SEASONABLE VALUES IN THE UPPER 40S/AROUND 50. A PROGRESSIVE
NORTHWEST MID/UPPER LEVEL FLOW REGIME WILL DRIVE ANOTHER CLIPPER
SYSTEM ACROSS THE NORTHERN PLAINS LATE MONDAY SENDING ANOTHER SURGE
OF MODIFIED ARCTIC AIR SOUTH ACROSS THE CENTRAL PLAINS INTO TUESDAY.
HIGHS MAY STRUGGLE TO REACH 30 ACROSS PORTIONS OF WESTERN AND
CENTRAL KANSAS WHILE SOUTHEAST KANSAS MAY CLIMB TO NEAR 40. A SUBTLE
SHORTWAVE TROUGH MAY ALLOW FOR A PERIOD OF LIGHT SNOW OR FLURRIES ON
TUESDAY HOWEVER CONFIDENCE REMAINS TOO LOW TO INCREASE POPS UP AT THIS
TIME. SURFACE HIGH PRESSURE WILL SETTLE OVER THE AREA TUESDAY NIGHT
ALLOWING FOR STRONG RADIATIONAL COOLING AND TRENDED LOWS DOWN WITH
VALUES IN THE TEENS ANTICIPATED.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 343 AM CST SUN FEB 23 2014
MODERATING TEMPERATURES ARE EXPECTED WED-THU AS NORTHWEST
MID/UPPER FLOW PREVAILS ACROSS THE CENTRAL CONUS. THE MID/UPPER
RIDGE ANCHORED ACROSS THE SOUTHWEST IS PROGGED TO FLATTEN ON
THURSDAY AS A MORE VIGOROUS TROUGH MOVES OVER THE GREAT BASIN
AREA. ANOTHER COLD FRONT IS PROGGED TO MOVE SOUTH ACROSS THE
NORTHERN AND CENTRAL PLAINS ON THURSDAY BRINGING AN END TO THE
WARMING TREND ALTHOUGH THE CHANCES FOR MEASURABLE PRECIPITATION
APPEAR TO REMAIN LOW AT THIS TIME. THERE REMAINS SOME POTENTIAL
FOR LIGHT PRECIPITATION BUT HIGHER PROBABILITIES APPEAR TO REMAIN
SOUTH AND EAST OF THE AREA AND MAINTAINED A SEASONABLY COOL AND
DRY FORECAST FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1210 PM CST SUN FEB 23 2014
MVFR CIGS WILL LINGER AT KRSL...KSLN AND KHUT FOR HALF OR MORE OF
THE FIRST PERIOD OF THE FORECAST CYCLE. PERISTENT STRATUS DECK THAT
ENVELOPES THE NORTHERN TWO-THIRDS OF KANSAS... NOT HANDLED WELL
BY MAJORITY OF FORECAST MODELS...BUT AS MENTIONED IN UPDATE
SECTION...BOTH RUC/HRRR APPEAR TO REINITALIZED AND CAPTURED
SITUATION. LATEST VISIBLE IMAGERY SHOWING SOME BREAKS IN THE
STRATUS...BUT TRENDED TOWARD MORE PESSIMISTIC SOLUTION OF KEEPING
MVFR CIGS AT KRSL...KSLN AND KHUT THROUGH 22-23 UTC. AS SURFACE
/LOW-LEVEL FLOW VEERS TO AN EASTERLY COMPONENT AFT 00 UTC...EXPECT
CIGS TO RETREAT WEST OF AFOREMENTIONED TAF SITES. BY 06 UTC...EXPECT
VFR CIGS AND VSBYS TO PREVAIL AT ALL TERMINAL SITES. NORTHEAST WINDS
WILL VEER THROUGH THE FORECAST PERIOD...BECOMING EAST TO SOUTHEAST
BY 12 UTC/24.
SF
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 44 24 49 26 / 0 0 10 10
HUTCHINSON 38 20 48 24 / 0 10 10 10
NEWTON 40 22 46 24 / 0 10 10 10
ELDORADO 44 23 47 26 / 0 0 10 10
WINFIELD-KWLD 48 24 49 28 / 0 0 10 10
RUSSELL 33 22 49 19 / 10 10 10 10
GREAT BEND 34 20 50 22 / 10 10 10 10
SALINA 35 22 46 22 / 10 10 10 10
MCPHERSON 36 22 47 24 / 10 10 10 10
COFFEYVILLE 49 23 49 31 / 0 0 10 10
CHANUTE 45 23 46 26 / 0 10 10 10
IOLA 44 24 45 25 / 0 10 10 10
PARSONS-KPPF 48 23 48 28 / 0 0 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1101 AM MST SUN FEB 23 2014
.UPDATE...
ISSUED AT 1009 AM MST SUN FEB 23 2014
CONDITIONS HAVE NOT CHANGED OVER THE PAST HOUR AND A HALF AND 15Z
RUC CONTINUES TO SUPPORT WIDESPREAD LOW CLOUDS WITH FOG ACROSS THE
AREA FOR THE REST OF THE DAY. HAVE ADJUSTED GRIDS ACCORDINGLY. IN
THE GOODLAND AREA VISIBILITIES CONTINUE AROUND ONE QUARTER MILE
WITH WEB CAMS AND METARS AROUND THE AREA SHOWING VISIBILITIES
HIGHER. SINCE CONDITIONS ARE NOT EXPECTED TO CHANGE MUCH HAVE GONE
AHEAD AND ISSUED A DENSE FOG ADVISORY FOR SHERMAN COUNTY TIL 20Z.
MAY HAVE TO GO LONGER BUT WILL WAIT AND SEE ON THAT.
UPDATE ISSUED AT 850 AM MST SUN FEB 23 2014
ENTIRE FORECAST AREA ENTRENCHED IN STRATUS THIS MORNING WITH
EAST/NORTHEAST WINDS EAST OF THE CO/KS BORDER AND SOUTHEAST WINDS
ACROSS FAR EASTERN COLORADO. FOG ALSO BEING REPORTED ACROSS THE
WESTERN 2/3 OF THE AREA WITH LOCALLY DENSE FOG IN THE GOODLAND
AREA.
LATEST RUC HAS AN EXCELLENT GRASP OF THE STRATUS AND PER THE 12Z
RUN KEEPS IT OVER THE AREA FOR THE ENTIRE DAY. THE HRRR BREAKS UP
THE STRATUS OVER PARTS OF FAR EASTERN COLORADO BUT KEEPS IT OVER
THE REST OF THE AREA THROUGH THE DAY AS WELL. SHOULD THESE
SCENARIOS VERIFY TEMPERATURES WONT MOVE MUCH FROM WHERE THEY ARE
NOW AND WOULD BE SEVERAL DEGREES BELOW PREVIOUS FORECAST.
12Z NAM BOUNDARY LAYER RH ALSO HAD A GOOD HANDLE ON AREAL COVERAGE
OF STRATUS BUT BY 18Z LIFTS IT/DISSIPATES IT FROM SOUTH TO NORTH
ALLOWING MORE HEATING AND WARMER TEMPERATURES THAN THE RUC/HRRR.
FOR THE FIRST OF WHAT WILL LIKELY BE SEVERAL UPDATES HAVE TRENDED
TOWARD THE RUC/HRRR GIVEN THE EASTERLY COMPONENT TO THE WINDS ALL
DAY WHICH IS NOT REAL FAVORABLE FOR RAPID STRATUS DISSIPATION AS
THE NAM WOULD SUGGEST. HAVE LOWERED HIGH TEMPERATURES TO THE
MID/UPPER 20S ACROSS THE NORTHEAST AND EAST (WHERE LOW CLOUDS
EXPECTED LONGER) AND LOW TO MID 30S ACROSS THE FAR SOUTH THROUGH
SOUTHWEST AND WEST WHERE SOME DISSIPATION WOULD BE MOST LIKELY BUT
NOT CERTAIN AT THIS POINT.
HAVE ALSO BEEFED UP THE FOG PER LOCAL OBSERVATIONS. NONE OF THE
MODELS HANDLING THIS VERY WELL...HOPEFULLY THE 15Z RUC WILL LATCH
ON TO IT AND GIVE SOME BETTER GUIDANCE.
MORE UPDATES LIKELY TO COME LATER.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 314 AM MST SUN FEB 23 2014
UPPER FLOW WILL BE NORTHWEST THROUGH TUESDAY NIGHT. SURFACE HIGH
PRESSURE WILL BE OVER THE REGION TODAY AND TONIGHT. HIGH PRESSURE
WILL DRIFT EAST MONDAY AS LOW PRESSURE MOVES INTO EASTERN COLORADO.
A COLD FRONT WILL PUSH SOUTH MONDAY NIGHT FOLLOWED BY HIGH PRESSURE
TUESDAY AND TUESDAY NIGHT.
CURRENT RADAR SHOWING DECREASING TREND OF SNOW RETURNS OVER THE
NORTH IN THE CURRENT WINTER WEATHER ADVISORY. FRONTOGENESIS EXITS
THE AREA AND DO NOT EXPECT ANYTHING MORE THAN LIGHT SNOW THIS
MORNING AND EVEN LESS OF AN AREA THIS AFTERNOON AS DYNAMICS MOVE OUT
OF THE AREA. PLAN TO CANCEL THE WINTER WEATHER ADVISORY AT ZONES
ISSUANCE. DEWPOINT DEPRESSIONS ARE NARROWING TO LESS THAN 3 DEGREES
AND BOUNDARY LAYER RH IS PROGGED TO INCREASE TO OVER 90 PERCENT SO
HAVE INCLUDED SOME PATCHY FREEZING FOG THIS MORNING OVER ALL BUT THE
NORTHEAST FA.
FORECAST SOUNDINGS ACROSS THE FA TONIGHT INDICATE THE POSSIBILITY OF
SOME STRATUS AND FOG BUT MOISTURE IS TOO SHALLOW TO INDICATE
FREEZING DRIZZLE. PLAN TO PULL THE FREEZING DRIZZLE AND CONSIDER
SOME MENTION OF FOG OVERNIGHT INTO MONDAY MORNING. POPS WILL BE NIL
MONDAY DUE TO SUBSIDENCE AND LACK OF MOISTURE. THERE IS SOME WEAK
FORCING ACROSS THE NORTHERN ZONES MONDAY NIGHT/TUESDAY MORNING AND
MOISTURE INCREASES SO CANNOT RULE OUT A SLIGHT CHANCE OF LIGHT SNOW
OR FLURRIES. FOR TUESDAY AFTERNOON/TUESDAY NIGHT...THE GFS IS FASTER
WITH BRINGING DYNAMICS INTO THE FA THAN THE NAM. FOR NOW WILL OPT
FOR THE GFS TO STAY CONSISTENT WITH SURROUNDING OFFICES. HOWEVER DUE
TO THE TIMING DIFFERENCES WILL KEEP POPS IN THE SLIGHT CHANCE/CHANCE
RANGE.
MAX TEMPERATURES TODAY WILL BE IN THE MID 30S EXCEPT FOR WESTERN
PORTIONS OF EASTERN COLORADO WHERE SOME LOWER 40S WILL BE POSSIBLE.
TEMPERATURES WILL WARM INTO THE 40S WITH SOME MID 50S POSSIBLE IN
THE SOUTHWEST PORTION OF THE FA. TUESDAY WILL BE COLDER BEHIND THE
FRONT WITH READINGS IN THE UPPER 20S AND LOW 30S. MIN TEMPERATURES
TONIGHT WILL FALL INTO THE LOWER 20S AND INTO THE TEENS MONDAY AND
TUESDAY NIGHTS.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 236 AM MST SUN FEB 23 2014
A RETURN OF BELOW NORMAL TEMPERATURES WILL BE THE MAIN
CHARACTERISTIC OF THE EXTENDED FORECAST WITH A FEW PERIODS OF SNOW
POSSIBLE. MODELS INDICATE THAT NORTHWEST FLOW IS THE PRIMARY UPPER
LEVEL PATTERN ACROSS THE TRI-STATE AREA WITH A LARGE TROUGH OVER THE
EASTERN UNITED STATES AND A RIDGE TO THE WEST. WITH THIS PATTERN IN
PLACE...THE GATE IS OPEN FOR COLD CANADIAN AIR TO MOVE IN. THIS
PATTERN IS SIMILAR TO THE EXTENDED VERY COLD OUTBREAK OBSERVED
EARLIER THIS MONTH. THE COLD WEATHER IS NOT EXPECTED TO REACH THAT
EXTENT AGAIN BUT WELL BELOW NORMAL TEMPERATURES SHOULD BE EXPECTED.
THE FORECAST INITIALIZATION PROCEDURE PROVIDED TEMPERATURES THAT
SEEMED UNREASONABLY WARM FOR THIS TYPE OF PATTERN. THE EUROPEAN
SEEMS MOST REASONABLE AND IS SUPPORTED BY THE CANADIAN MODEL. THE
OPERATIONAL GFS HAS 850 MB TEMPS IN THE SAME BALLPARK AS THE
EUROPEAN HOWEVER MEX GUIDANCE IS 10 TO NEARLY 20 DEGREES WARMER FOR
FRIDAY AND SATURDAY. AS A RESULT...TEMPERATURES WERE NUDGED DOWN A
FEW DEGREES BUT FORECAST IS STILL PROBABLY TOO WARM.
AS FOR PRECIPITATION...THERE ARE TWO CHANCES AT WINTRY PRECIP DURING
THE EXTENDED PERIOD. FOR WEDNESDAY...THE UPPER LEVEL DISTURBANCE
THAT WILL BRING SNOW FOR TUESDAY NIGHT SHOULD BE CLEAR OF THE REGION
WITH HIGH PRESSURE BUILDING IN. ADVERTISED DRY CONDITIONS FOR
WEDNESDAY BUT A FEW FLURRIES MAY LINGER DEPENDING ON SPEED AND
MOVEMENT OF THIS SYSTEM. THE FIRST CHANCE FOR PRECIPITATION IN THE
EXTENDED FORECAST IS ANTICIPATED ON THURSDAY NIGHT INTO FRIDAY. THIS
CHANCE COMES AS A STRONGER DISTURBANCE IN THE NORTHWEST FLOW
TRANSITIONS ACROSS THE REGION. MODELS DISAGREE SOMEWHAT IN THE
PLACEMENT AND MOVEMENT OF THIS SYSTEM SO HAVE ONLY GONE SLIGHT
CHANCE TO LOW CHANCE POPS FOR THURSDAY NIGHT. DUE TO THE SPEED OF
THIS SYSTEM...AN EXTENDED PERIOD OF ACCUMULATING SNOW IS NOT
EXPECTED. IT IS ALSO POSSIBLE THIS SYSTEM MOVES SOUTH OF THE AREA
WITH NO SNOW AS THE BEST FORCING APPEARS TO REMAIN SOUTH.
THE SECOND...MORE SIGNIFICANT CHANCE OF PRECIPITATION COMES FOR NEXT
WEEKEND. THROUGH 00Z SATURDAY...THE EUROPEAN...CANADIAN AND GFS
MODELS ARE IN DECENT AGREEMENT ON A 500 MB LOW COMING INTO
CALIFORNIA. THE GFS AND EUROPEAN MODELS THEN BRING THIS SYSTEM
ACROSS THE ROCKIES ON SATURDAY AND INTO THE HIGH PLAINS SUNDAY.
THESE TYPES OF SYSTEMS ARE TYPICALLY RESPONSIBLE FOR LARGER SNOW
AMOUNTS SO WILL NEED TO MONITOR THIS SYSTEM CLOSELY. AS WITH ANY
EXTENDED FORECAST...MODELS CAN AND OFTEN DO CHANGE THEIR SOLUTIONS
THIS FAR OUT. HOWEVER...WITH BOTH MODELS PICKING UP ON IT AND
PROJECTING A SIMILAR SOLUTION...THIS MAY HAVE A LITTLE MORE WEIGHT
TO IT THAN A TYPICAL EXTENDED FORECAST STORM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1031 AM MST SUN FEB 23 2014
THIS TAF PERIOD WILL BE A MESSY ONE AS A STATIONARY FRONT TO THE
WEST OF THE TRI STATE AREA WILL KEEP CONDITIONS OVERCAST THROUGH
MOST OF THE TAF PERIOD FOR BOTH TERMINALS. PINNING DOWN
VISIBILITIES FOR KGLD AND CEILING HEIGHTS FOR BOTH TERMINALS WAS A
BIT TOUGH WITH MODEL GUIDANCE DIFFERING A LOT.
REDUCED VISIBILITIES EXPECTED TO CONTINUE AT KGLD FOR THE REST OF
THE MORNING AND INTO THE EARLY AFTERNOON HOURS BEFORE CONDITIONS
IMPROVE TO MVFR. A BRIEF BREAK WILL OCCUR AROUND SUNDOWN WITH
IMPROVED CONDITIONS BEFORE OVERCAST CONDITIONS AND REDUCED
VISIBILITIES RETURN FOR OVERNIGHT.
OVERCAST CONDITIONS AT KMCK WILL CONTINUE INTO TONIGHT. SOME AREAS
OF PATCHY FOG AROUND THE TERMINAL WILL DEVELOP...SO MENTIONED MVFR
CONDITIONS FOR VISIBILITY. CONDITIONS WILL IMPROVE TO VFR BY MID
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...DENSE FOG ADVISORY UNTIL 1 PM MST THIS AFTERNOON FOR KSZ013.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...FS
LONG TERM...RRH
AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1011 AM MST SUN FEB 23 2014
.UPDATE...
ISSUED AT 1009 AM MST SUN FEB 23 2014
CONDITIONS HAVE NOT CHANGED OVER THE PAST HOUR AND A HALF AND 15Z
RUC CONTINUES TO SUPPORT WIDESPREAD LOW CLOUDS WITH FOG ACROSS THE
AREA FOR THE REST OF THE DAY. HAVE ADJUSTED GRIDS ACCORDINGLY. IN
THE GOODLAND AREA VISIBILITIES CONTINUE AROUND ONE QUARTER MILE
WITH WEB CAMS AND METARS AROUND THE AREA SHOWING VISIBILITIES
HIGHER. SINCE CONDITIONS ARE NOT EXPECTED TO CHANGE MUCH HAVE GONE
AHEAD AND ISSUED A DENSE FOG ADVISORY FOR SHERMAN COUNTY TIL 20Z.
MAY HAVE TO GO LONGER BUT WILL WAIT AND SEE ON THAT.
UPDATE ISSUED AT 850 AM MST SUN FEB 23 2014
ENTIRE FORECAST AREA ENTRENCHED IN STRATUS THIS MORNING WITH
EAST/NORTHEAST WINDS EAST OF THE CO/KS BORDER AND SOUTHEAST WINDS
ACROSS FAR EASTERN COLORADO. FOG ALSO BEING REPORTED ACROSS THE
WESTERN 2/3 OF THE AREA WITH LOCALLY DENSE FOG IN THE GOODLAND
AREA.
LATEST RUC HAS AN EXCELLENT GRASP OF THE STRATUS AND PER THE 12Z
RUN KEEPS IT OVER THE AREA FOR THE ENTIRE DAY. THE HRRR BREAKS UP
THE STRATUS OVER PARTS OF FAR EASTERN COLORADO BUT KEEPS IT OVER
THE REST OF THE AREA THROUGH THE DAY AS WELL. SHOULD THESE
SCENARIOS VERIFY TEMPERATURES WONT MOVE MUCH FROM WHERE THEY ARE
NOW AND WOULD BE SEVERAL DEGREES BELOW PREVIOUS FORECAST.
12Z NAM BOUNDARY LAYER RH ALSO HAD A GOOD HANDLE ON AREAL COVERAGE
OF STRATUS BUT BY 18Z LIFTS IT/DISSIPATES IT FROM SOUTH TO NORTH
ALLOWING MORE HEATING AND WARMER TEMPERATURES THAN THE RUC/HRRR.
FOR THE FIRST OF WHAT WILL LIKELY BE SEVERAL UPDATES HAVE TRENDED
TOWARD THE RUC/HRRR GIVEN THE EASTERLY COMPONENT TO THE WINDS ALL
DAY WHICH ISNT REAL FAVORABLE FOR RAPID STRATUS DISSIPATION AS THE
NAM WOULD SUGGEST. HAVE LOWERED HIGH TEMPERATURES TO THE MID/UPPER
20S ACROSS THE NORTHEAST AND EAST (WHERE LOW CLOUDS EXPECTED
LONGER) AND LOW TO MID 30S ACROSS THE FAR SOUTH THROUGH SOUTHWEST
AND WEST WHERE SOME DISSIPATION WOULD BE MOST LIKELY BUT NOT
CERTAIN AT THIS POINT.
HAVE ALSO BEEFED UP THE FOG PER LOCAL OBSERVATIONS. NONE OF THE
MODELS HANDLING THIS VERY WELL...HOPEFULLY THE 15Z RUC WILL LATCH
ON TO IT AND GIVE SOME BETTER GUIDANCE.
MORE UPDATES LIKELY TO COME LATER.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 314 AM MST SUN FEB 23 2014
UPPER FLOW WILL BE NORTHWEST THROUGH TUESDAY NIGHT. SURFACE HIGH
PRESSURE WILL BE OVER THE REGION TODAY AND TONIGHT. HIGH PRESSURE
WILL DRIFT EAST MONDAY AS LOW PRESSURE MOVES INTO EASTERN COLORADO.
A COLD FRONT WILL PUSH SOUTH MONDAY NIGHT FOLLOWED BY HIGH PRESSURE
TUESDAY AND TUESDAY NIGHT.
CURRENT RADAR SHOWING DECREASING TREND OF SNOW RETURNS OVER THE
NORTH IN THE CURRENT WINTER WEATHER ADVISORY. FRONTOGENESIS EXITS
THE AREA AND DO NOT EXPECT ANYTHING MORE THAN LIGHT SNOW THIS
MORNING AND EVEN LESS OF AN AREA THIS AFTERNOON AS DYNAMICS MOVE OUT
OF THE AREA. PLAN TO CANCEL THE WINTER WEATHER ADVISORY AT ZONES
ISSUANCE. DEWPOINT DEPRESSIONS ARE NARROWING TO LESS THAN 3 DEGREES
AND BOUNDARY LAYER RH IS PROGGED TO INCREASE TO OVER 90 PERCENT SO
HAVE INCLUDED SOME PATCHY FREEZING FOG THIS MORNING OVER ALL BUT THE
NORTHEAST FA.
FORECAST SOUNDINGS ACROSS THE FA TONIGHT INDICATE THE POSSIBILITY OF
SOME STRATUS AND FOG BUT MOISTURE IS TOO SHALLOW TO INDICATE
FREEZING DRIZZLE. PLAN TO PULL THE FREEZING DRIZZLE AND CONSIDER
SOME MENTION OF FOG OVERNIGHT INTO MONDAY MORNING. POPS WILL BE NIL
MONDAY DUE TO SUBSIDENCE AND LACK OF MOISTURE. THERE IS SOME WEAK
FORCING ACROSS THE NORTHERN ZONES MONDAY NIGHT/TUESDAY MORNING AND
MOISTURE INCREASES SO CANNOT RULE OUT A SLIGHT CHANCE OF LIGHT SNOW
OR FLURRIES. FOR TUESDAY AFTERNOON/TUESDAY NIGHT...THE GFS IS FASTER
WITH BRINGING DYNAMICS INTO THE FA THAN THE NAM. FOR NOW WILL OPT FOR
THE GFS TO STAY CONSISTENT WITH SURROUNDING OFFICES. HOWEVER DUE TO
THE TIMING DIFFERENCES WILL KEEP POPS IN THE SLIGHT CHANCE/CHANCE
RANGE.
MAX TEMPERATURES TODAY WILL BE IN THE MID 30S EXCEPT FOR WESTERN
PORTIONS OF EASTERN COLORADO WHERE SOME LOWER 40S WILL BE POSSIBLE.
TEMPERATURES WILL WARM INTO THE 40S WITH SOME MID 50S POSSIBLE IN
THE SOUTHWEST PORTION OF THE FA. TUESDAY WILL BE COLDER BEHIND THE
FRONT WITH READINGS IN THE UPPER 20S AND LOW 30S. MIN TEMPERATURES
TONIGHT WILL FALL INTO THE LOWER 20S AND INTO THE TEENS MONDAY AND
TUESDAY NIGHTS.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 236 AM MST SUN FEB 23 2014
A RETURN OF BELOW NORMAL TEMPERATURES WILL BE THE MAIN
CHARACTERISTIC OF THE EXTENDED FORECAST WITH A FEW PERIODS OF SNOW
POSSIBLE. MODELS INDICATE THAT NORTHWEST FLOW IS THE PRIMARY UPPER
LEVEL PATTERN ACROSS THE TRI-STATE AREA WITH A LARGE TROUGH OVER THE
EASTERN UNITED STATES AND A RIDGE TO THE WEST. WITH THIS PATTERN IN
PLACE...THE GATE IS OPEN FOR COLD CANADIAN AIR TO MOVE IN. THIS PATTERN
IS SIMILAR TO THE EXTENDED VERY COLD OUTBREAK OBSERVED EARLIER THIS
MONTH. THE COLD WEATHER IS NOT EXPECTED TO REACH THAT EXTENT AGAIN
BUT WELL BELOW NORMAL TEMPERATURES SHOULD BE EXPECTED. THE FORECAST
INITIALIZATION PROCEDURE PROVIDED TEMPERATURES THAT SEEMED
UNREASONABLY WARM FOR THIS TYPE OF PATTERN. THE EUROPEAN SEEMS MOST
REASONABLE AND IS SUPPORTED BY THE CANADIAN MODEL. THE OPERATIONAL
GFS HAS 850 MB TEMPS IN THE SAME BALLPARK AS THE EUROPEAN HOWEVER
MEX GUIDANCE IS 10 TO NEARLY 20 DEGREES WARMER FOR FRIDAY AND
SATURDAY. AS A RESULT...TEMPERATURES WERE NUDGED DOWN A FEW DEGREES
BUT FORECAST IS STILL PROBABLY TOO WARM.
AS FOR PRECIPITATION...THERE ARE TWO CHANCES AT WINTRY PRECIP DURING
THE EXTENDED PERIOD. FOR WEDNESDAY...THE UPPER LEVEL DISTURBANCE
THAT WILL BRING SNOW FOR TUESDAY NIGHT SHOULD BE CLEAR OF THE REGION
WITH HIGH PRESSURE BUILDING IN. ADVERTISED DRY CONDITIONS FOR
WEDNESDAY BUT A FEW FLURRIES MAY LINGER DEPENDING ON SPEED AND
MOVEMENT OF THIS SYSTEM. THE FIRST CHANCE FOR PRECIPITATION IN THE
EXTENDED FORECAST IS ANTICIPATED ON THURSDAY NIGHT INTO FRIDAY. THIS
CHANCE COMES AS A STRONGER DISTURBANCE IN THE NORTHWEST FLOW
TRANSITIONS ACROSS THE REGION. MODELS DISAGREE SOMEWHAT IN THE
PLACEMENT AND MOVEMENT OF THIS SYSTEM SO HAVE ONLY GONE SLIGHT
CHANCE TO LOW CHANCE POPS FOR THURSDAY NIGHT. DUE TO THE SPEED OF
THIS SYSTEM...AN EXTENDED PERIOD OF ACCUMULATING SNOW IS NOT
EXPECTED. IT IS ALSO POSSIBLE THIS SYSTEM MOVES SOUTH OF THE AREA
WITH NO SNOW AS THE BEST FORCING APPEARS TO REMAIN SOUTH.
THE SECOND...MORE SIGNIFICANT CHANCE OF PRECIPITATION COMES FOR NEXT
WEEKEND. THROUGH 00Z SATURDAY...THE EUROPEAN...CANADIAN AND GFS
MODELS ARE IN DECENT AGREEMENT ON A 500 MB LOW COMING INTO
CALIFORNIA. THE GFS AND EUROPEAN MODELS THEN BRING THIS SYSTEM
ACROSS THE ROCKIES ON SATURDAY AND INTO THE HIGH PLAINS SUNDAY. THESE
TYPES OF SYSTEMS ARE TYPICALLY RESPONSIBLE FOR LARGER SNOW AMOUNTS
SO WILL NEED TO MONITOR THIS SYSTEM CLOSELY. AS WITH ANY EXTENDED
FORECAST...MODELS CAN AND OFTEN DO CHANGE THEIR SOLUTIONS THIS FAR
OUT. HOWEVER...WITH BOTH MODELS PICKING UP ON IT AND PROJECTING A
SIMILAR SOLUTION...THIS MAY HAVE A LITTLE MORE WEIGHT TO IT THAN A
TYPICAL EXTENDED FORECAST STORM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 438 AM MST SUN FEB 23 2014
SOME IFR AND LIFR CONDITIONS WILL CONTINUE THIS MORNING AT KGLD AND KMCK
BEHIND AN EXITING SHORTWAVE. CONDITIONS SHOULD IMPROVE TO MVFR AT
KGLD THIS AFTERNOON BUT WILL DROP BACK DOWN TO IFR TONIGHT AS FOG
AND STRATUS OVERTAKE THE AREA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...DENSE FOG ADVISORY FROM 6 PM TO 7 PM MST THIS EVENING FOR KSZ013.
DENSE FOG ADVISORY UNTIL 1 PM MST THIS AFTERNOON FOR KSZ013.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...FS
LONG TERM...RRH
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
850 AM MST SUN FEB 23 2014
.UPDATE...
ISSUED AT 850 AM MST SUN FEB 23 2014
ENTIRE FORECAST AREA ENTRENCHED IN STRATUS THIS MORNING WITH
EAST/NORTHEAST WINDS EAST OF THE CO/KS BORDER AND SOUTHEAST WINDS
ACROSS FAR EASTERN COLORADO. FOG ALSO BEING REPORTED ACROSS THE
WESTERN 2/3 OF THE AREA WITH LOCALLY DENSE FOG IN THE GOODLAND
AREA.
LATEST RUC HAS AN EXCELLENT GRASP OF THE STRATUS AND PER THE 12Z
RUN KEEPS IT OVER THE AREA FOR THE ENTIRE DAY. THE HRRR BREAKS UP
THE STRATUS OVER PARTS OF FAR EASTERN COLORADO BUT KEEPS IT OVER
THE REST OF THE AREA THROUGH THE DAY AS WELL. SHOULD THESE
SCENARIOS VERIFY TEMPERATURES WONT MOVE MUCH FROM WHERE THEY ARE
NOW AND WOULD BE SEVERAL DEGREES BELOW PREVIOUS FORECAST.
12Z NAM BOUNDARY LAYER RH ALSO HAD A GOOD HANDLE ON AREAL COVERAGE
OF STRATUS BUT BY 18Z LIFTS IT/DISSIPATES IT FROM SOUTH TO NORTH
ALLOWING MORE HEATING AND WARMER TEMPERATURES THAN THE RUC/HRRR.
FOR THE FIRST OF WHAT WILL LIKELY BE SEVERAL UPDATES HAVE TRENDED
TOWARD THE RUC/HRRR GIVEN THE EASTERLY COMPONENT TO THE WINDS ALL
DAY WHICH ISNT REAL FAVORABLE FOR RAPID STRATUS DISSIPATION AS THE
NAM WOULD SUGGEST. HAVE LOWERED HIGH TEMPERATURES TO THE MID/UPPER
20S ACROSS THE NORTHEAST AND EAST (WHERE LOW CLOUDS EXPECTED
LONGER) AND LOW TO MID 30S ACROSS THE FAR SOUTH THROUGH SOUTHWEST
AND WEST WHERE SOME DISSIPATION WOULD BE MOST LIKELY BUT NOT
CERTAIN AT THIS POINT.
HAVE ALSO BEEFED UP THE FOG PER LOCAL OBSERVATIONS. NONE OF THE
MODELS HANDLING THIS VERY WELL...HOPEFULLY THE 15Z RUC WILL LATCH
ON TO IT AND GIVE SOME BETTER GUIDANCE.
MORE UPDATES LIKELY TO COME LATER.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 314 AM MST SUN FEB 23 2014
UPPER FLOW WILL BE NORTHWEST THROUGH TUESDAY NIGHT. SURFACE HIGH
PRESSURE WILL BE OVER THE REGION TODAY AND TONIGHT. HIGH PRESSURE
WILL DRIFT EAST MONDAY AS LOW PRESSURE MOVES INTO EASTERN COLORADO.
A COLD FRONT WILL PUSH SOUTH MONDAY NIGHT FOLLOWED BY HIGH PRESSURE
TUESDAY AND TUESDAY NIGHT.
CURRENT RADAR SHOWING DECREASING TREND OF SNOW RETURNS OVER THE
NORTH IN THE CURRENT WINTER WEATHER ADVISORY. FRONTOGENESIS EXITS
THE AREA AND DO NOT EXPECT ANYTHING MORE THAN LIGHT SNOW THIS
MORNING AND EVEN LESS OF AN AREA THIS AFTERNOON AS DYNAMICS MOVE OUT
OF THE AREA. PLAN TO CANCEL THE WINTER WEATHER ADVISORY AT ZONES
ISSUANCE. DEWPOINT DEPRESSIONS ARE NARROWING TO LESS THAN 3 DEGREES
AND BOUNDARY LAYER RH IS PROGGED TO INCREASE TO OVER 90 PERCENT SO
HAVE INCLUDED SOME PATCHY FREEZING FOG THIS MORNING OVER ALL BUT THE
NORTHEAST FA.
FORECAST SOUNDINGS ACROSS THE FA TONIGHT INDICATE THE POSSIBILITY OF
SOME STRATUS AND FOG BUT MOISTURE IS TOO SHALLOW TO INDICATE
FREEZING DRIZZLE. PLAN TO PULL THE FREEZING DRIZZLE AND CONSIDER
SOME MENTION OF FOG OVERNIGHT INTO MONDAY MORNING. POPS WILL BE NIL
MONDAY DUE TO SUBSIDENCE AND LACK OF MOISTURE. THERE IS SOME WEAK
FORCING ACROSS THE NORTHERN ZONES MONDAY NIGHT/TUESDAY MORNING AND
MOISTURE INCREASES SO CANNOT RULE OUT A SLIGHT CHANCE OF LIGHT SNOW
OR FLURRIES. FOR TUESDAY AFTERNOON/TUESDAY NIGHT...THE GFS IS FASTER
WITH BRINGING DYNAMICS INTO THE FA THAN THE NAM. FOR NOW WILL OPT FOR
THE GFS TO STAY CONSISTENT WITH SURROUNDING OFFICES. HOWEVER DUE TO
THE TIMING DIFFERENCES WILL KEEP POPS IN THE SLIGHT CHANCE/CHANCE
RANGE.
MAX TEMPERATURES TODAY WILL BE IN THE MID 30S EXCEPT FOR WESTERN
PORTIONS OF EASTERN COLORADO WHERE SOME LOWER 40S WILL BE POSSIBLE.
TEMPERATURES WILL WARM INTO THE 40S WITH SOME MID 50S POSSIBLE IN
THE SOUTHWEST PORTION OF THE FA. TUESDAY WILL BE COLDER BEHIND THE
FRONT WITH READINGS IN THE UPPER 20S AND LOW 30S. MIN TEMPERATURES
TONIGHT WILL FALL INTO THE LOWER 20S AND INTO THE TEENS MONDAY AND
TUESDAY NIGHTS.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 236 AM MST SUN FEB 23 2014
A RETURN OF BELOW NORMAL TEMPERATURES WILL BE THE MAIN
CHARACTERISTIC OF THE EXTENDED FORECAST WITH A FEW PERIODS OF SNOW
POSSIBLE. MODELS INDICATE THAT NORTHWEST FLOW IS THE PRIMARY UPPER
LEVEL PATTERN ACROSS THE TRI-STATE AREA WITH A LARGE TROUGH OVER THE
EASTERN UNITED STATES AND A RIDGE TO THE WEST. WITH THIS PATTERN IN
PLACE...THE GATE IS OPEN FOR COLD CANADIAN AIR TO MOVE IN. THIS PATTERN
IS SIMILAR TO THE EXTENDED VERY COLD OUTBREAK OBSERVED EARLIER THIS
MONTH. THE COLD WEATHER IS NOT EXPECTED TO REACH THAT EXTENT AGAIN
BUT WELL BELOW NORMAL TEMPERATURES SHOULD BE EXPECTED. THE FORECAST
INITIALIZATION PROCEDURE PROVIDED TEMPERATURES THAT SEEMED
UNREASONABLY WARM FOR THIS TYPE OF PATTERN. THE EUROPEAN SEEMS MOST
REASONABLE AND IS SUPPORTED BY THE CANADIAN MODEL. THE OPERATIONAL
GFS HAS 850 MB TEMPS IN THE SAME BALLPARK AS THE EUROPEAN HOWEVER
MEX GUIDANCE IS 10 TO NEARLY 20 DEGREES WARMER FOR FRIDAY AND
SATURDAY. AS A RESULT...TEMPERATURES WERE NUDGED DOWN A FEW DEGREES
BUT FORECAST IS STILL PROBABLY TOO WARM.
AS FOR PRECIPITATION...THERE ARE TWO CHANCES AT WINTRY PRECIP DURING
THE EXTENDED PERIOD. FOR WEDNESDAY...THE UPPER LEVEL DISTURBANCE
THAT WILL BRING SNOW FOR TUESDAY NIGHT SHOULD BE CLEAR OF THE REGION
WITH HIGH PRESSURE BUILDING IN. ADVERTISED DRY CONDITIONS FOR
WEDNESDAY BUT A FEW FLURRIES MAY LINGER DEPENDING ON SPEED AND
MOVEMENT OF THIS SYSTEM. THE FIRST CHANCE FOR PRECIPITATION IN THE
EXTENDED FORECAST IS ANTICIPATED ON THURSDAY NIGHT INTO FRIDAY. THIS
CHANCE COMES AS A STRONGER DISTURBANCE IN THE NORTHWEST FLOW
TRANSITIONS ACROSS THE REGION. MODELS DISAGREE SOMEWHAT IN THE
PLACEMENT AND MOVEMENT OF THIS SYSTEM SO HAVE ONLY GONE SLIGHT
CHANCE TO LOW CHANCE POPS FOR THURSDAY NIGHT. DUE TO THE SPEED OF
THIS SYSTEM...AN EXTENDED PERIOD OF ACCUMULATING SNOW IS NOT
EXPECTED. IT IS ALSO POSSIBLE THIS SYSTEM MOVES SOUTH OF THE AREA
WITH NO SNOW AS THE BEST FORCING APPEARS TO REMAIN SOUTH.
THE SECOND...MORE SIGNIFICANT CHANCE OF PRECIPITATION COMES FOR NEXT
WEEKEND. THROUGH 00Z SATURDAY...THE EUROPEAN...CANADIAN AND GFS
MODELS ARE IN DECENT AGREEMENT ON A 500 MB LOW COMING INTO
CALIFORNIA. THE GFS AND EUROPEAN MODELS THEN BRING THIS SYSTEM
ACROSS THE ROCKIES ON SATURDAY AND INTO THE HIGH PLAINS SUNDAY. THESE
TYPES OF SYSTEMS ARE TYPICALLY RESPONSIBLE FOR LARGER SNOW AMOUNTS
SO WILL NEED TO MONITOR THIS SYSTEM CLOSELY. AS WITH ANY EXTENDED
FORECAST...MODELS CAN AND OFTEN DO CHANGE THEIR SOLUTIONS THIS FAR
OUT. HOWEVER...WITH BOTH MODELS PICKING UP ON IT AND PROJECTING A
SIMILAR SOLUTION...THIS MAY HAVE A LITTLE MORE WEIGHT TO IT THAN A
TYPICAL EXTENDED FORECAST STORM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 438 AM MST SUN FEB 23 2014
SOME IFR AND LIFR CONDITIONS WILL CONTINUE THIS MORNING AT KGLD AND KMCK
BEHIND AN EXITING SHORTWAVE. CONDITIONS SHOULD IMPROVE TO MVFR AT
KGLD THIS AFTERNOON BUT WILL DROP BACK DOWN TO IFR TONIGHT AS FOG
AND STRATUS OVERTAKE THE AREA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...FS
LONG TERM...RRH
AVIATION...FS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
259 PM EST SUN FEB 23 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THIS EVENING BRINGING LIGHT RAIN AND
LIGHT SNOW TO LOCATIONS SOUTH OF INTERSTATE 70. COLD WEATHER IS
PREDICTED FOR MOST OF THE WEEK WITH A RETURN OF ARCTIC AIR. NO
SIGNIFICANT SNOW ACCUMULATION IS FORECAST THIS WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
SURFACE TROUGH AXIS CONTINUES TO HAVE A TOUGH TIME SQUEEZING OUT
MOISTURE. STILL FEEL WITH APPROACHING S/W TROUGH AND PASSAGE OF
LOWER TROPOPAUSE HEIGHTS THAT LIGHT ACTIVITY IS A GOOD BET FOR A
3-5 HR WINDOW. TIGHTENED UP POP GRADIENT AND MAINTAINED LIGHT
RA/SN QUALIFIER FOR LOCATIONS S OF I-70. USED HRRR TO PINPOINT
HIGHEST POPS OF 22-03Z. QPF AMOUNTS WILL BE A FEW HUNDREDTHS AND
EVEN WITH SNOW RATIOS HIGHER THAN CLIMO STILL THINK ANY LOCATION
WILL BE HARD PRESSED TO GET MORE THAN AN INCH.
A BREAK IN THE WEATHER OVERNIGHT THROUGH MOST OF MONDAY AS WE
AWAIT MID LVL HEIGHT FALLS AND ACCOMPANYING MID LVL IMPULSE TO
INVADE FROM THE N. CHC POPS N OF I-80 AT THIS TIME SEEM PRUDENT
GIVEN QUESTIONABLE MOISTURE ESPECIALLY WITH A FROZEN LAKE ERIE.
WINDS WILL BE THE MAIN STORY MONDAY WITH GUSTS ECLIPSING 20 MPH IN
THE AFTERNOON.
ICE JAMS REMAIN A CONCERN. WITH TEMPERATURES FALLING BELOW
FREEZING THIS EVENING AND CONTINUING THE NEXT SEVERAL DAYS THE
THREAT OF ICE JAM FLOODING WILL DECREASE. ONLY TO AGAIN BE RE-
VISITED IN MARCH WHEN WE WARM WELL ABOVE FREEZING.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
LOW CONFIDENCE IN THE SHORT TERM PERIOD WITH SEVERAL ROUNDS OF SNOW
SHOWERS POSSIBLE TUES AND THEN AGAIN WEDS. MODELS STILL HAVING A
DIFFICULT TIME IN HANDLING THESE SHORTWAVES...ESPECIALLY THE WEDS
SYSTEM. THE NAM/GFS IS A LITTLE SLOWER AND LESS PROGRESSIVE THAN THE
SREF/ECMWF SOLNS. STICKING WITH MORE OF A BLEND THAN DETERMINISTIC
APPROACH WITH THIS UPDATE...LIMITING SNOW SHOWER PROBABILITIES TO
THE CHC RANGE.
WITH OUR AREA REMAINING UNDER THE INFLUENCE OF THE BROAD TROUGH OVER
THE ERN CONUS...NW FLOW ALOFT WILL KEEP TEMPERATURES COLDER THAN
AVERAGE. WILL REMAIN ON THE COLDER SIDE OF GUIDANCE THROUGH MIDWEEK.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
WINTER CONTINUES IN THE LONG TERM. ONCE AGAIN...ARCTIC AIR WILL
SETTLE IN THE EAST FOR THE SECOND HALF OF THE WEEK. REALLY NO
SYSTEMS TO HIT ON FOR PRECIP...JUST THE CROSSING OF A WEAK FRONT
THURSDAY.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
HIGH CONFIDENCE FORECAST.
VFR CONDITIONS WILL CONTINUE THROUGH THE NEXT 24 HOURS...SAVE FOR
BVI WHERE BKN STRATOCU WILL OCCUR THROUGH THE EARLY AFTERNOON. A
COLD FRONT WILL CROSS THE REGION WITH LITTLE FAN FAR AT AREA
TERMINALS. MOST LIKELY IMPACTED LOCATIONS ARE MGW/LBE WHERE VFR
-RASN COULD OCCUR BTWN 20Z-0Z.
TONIGHT ALL TERMINALS RETURN TO VFR UNDER A BKN MID DECK WHICH
WILL YIELD TO SCT CI. WINDS WILL INCREASE MONDAY MORNING WITH THE
APPROACH OF AN UPPER AIR SYSTEM DIVING DOWN FROM THE GREAT LAKES.
GUSTS COULD EXCEED 20KTS AT FKL AND DUJ.
.OUTLOOK..../18Z MONDAY THROUGH FRIDAY/...
THE PASSING OF A STRONG UPPER AIR DISTURBANCE TUESDAY NIGHT INTO
WEDNESDAY WILL BRING RESTRICTIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
229 PM EST SUN FEB 23 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THIS EVENING BRINGING LIGHT RAIN AND
LIGHT SNOW TO LOCATIONS SOUTH OF INTERSTATE 70. COLD WEATHER IS
PREDICTED FOR MOST OF THE WEEK WITH A RETURN OF ARCTIC AIR. NO
SIGNIFICANT SNOW ACCUMULATION IS FORECAST THIS WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
SURFACE TROUGH AXIS CONTINUES TO HAVE A TOUGH TIME SQUEEZING OUT
MOISTURE. STILL FEEL WITH APPROACHING S/W TROUGH AND PASSAGE OF
LOWER TROPOPAUSE HEIGHTS THAT LIGHT ACTIVITY IS A GOOD BET FOR A
3-5 HR WINDOW. TIGHTENED UP POP GRADIENT AND MAINTAINED LIGHT
RA/SN QUALIFIER FOR LOCATIONS S OF I-70. USED HRRR TO PINPOINT
HIGHEST POPS OF 22-03Z. QPF AMOUNTS WILL BE A FEW HUNDREDTHS AND
EVEN WITH SNOW RATIOS HIGHER THAN CLIMO STILL THINK ANY LOCATION
WILL BE HARD PRESSED TO GET MORE THAN AN INCH.
A BREAK IN THE WEATHER OVERNIGHT THROUGH MOST OF MONDAY AS WE
AWAIT MID LVL HEIGHT FALLS AND ACCOMPANYING MID LVL IMPULSE TO
INVADE FROM THE N. CHC POPS N OF I-80 AT THIS TIME SEEM PRUDENT
GIVEN QUESTIONABLE MOISTURE ESPECIALLY WITH A FROZEN LAKE ERIE.
WINDS WILL BE THE MAIN STORY MONDAY WITH GUSTS ECLIPSING 20 MPH IN
THE AFTERNOON.
ICE JAMS REMAIN A CONCERN. WITH TEMPERATURES FALLING BELOW
FREEZING THIS EVENING AND CONTINUING THE NEXT SEVERAL DAYS THE
THREAT OF ICE JAM FLOODING WILL DECREASE. ONLY TO AGAIN BE RE-
VISITED IN MARCH WHEN WE WARM WELL ABOVE FREEZING.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
LOW CONFIDENCE FOR TUESDAY`S FORECAST DUE TO DIFFERING MODEL
SOLUTIONS WITH ANOTHER UPPER LEVEL WAVE. WILL GO WITH A MIDDLE OF
THE ROAD FORECAST...MEANING CHANCE POPS FOR SNOW SHOWERS.
AREA WILL BE WELL BACK INTO THE COLD PATTERN BY TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
WINTER CONTINUES IN THE LONG TERM. ONCE AGAIN...ARCTIC AIR WILL
SETTLE IN THE EAST FOR THE SECOND HALF OF THE WEEK. REALLY NO
SYSTEMS TO HIT ON FOR PRECIP...JUST THE CROSSING OF A WEAK FRONT
THURSDAY.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
HIGH CONFIDENCE FORECAST.
VFR CONDITIONS WILL CONTINUE THROUGH THE NEXT 24 HOURS...SAVE FOR
BVI WHERE BKN STRATOCU WILL OCCUR THROUGH THE EARLY AFTERNOON. A
COLD FRONT WILL CROSS THE REGION WITH LITTLE FAN FAR AT AREA
TERMINALS. MOST LIKELY IMPACTED LOCATIONS ARE MGW/LBE WHERE VFR
-RASN COULD OCCUR BTWN 20Z-0Z.
TONIGHT ALL TERMINALS RETURN TO VFR UNDER A BKN MID DECK WHICH
WILL YIELD TO SCT CI. WINDS WILL INCREASE MONDAY MORNING WITH THE
APPROACH OF AN UPPER AIR SYSTEM DIVING DOWN FROM THE GREAT LAKES.
GUSTS COULD EXCEED 20KTS AT FKL AND DUJ.
.OUTLOOK..../18Z MONDAY THROUGH FRIDAY/...
THE PASSING OF A STRONG UPPER AIR DISTURBANCE TUESDAY NIGHT INTO
WEDNESDAY WILL BRING RESTRICTIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
644 PM EST MON FEB 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 357 PM EST MON FEB 24 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PERSISTENT...COLD
NW FLOW DOMINATING THE GREAT LKS BTWN RDG ALONG THE W COAST AND
CLOSED LO OVER QUEBEC/TROF IN ERN NAMERICA. COMBINATION OF SHRTWV
EMBEDDED IN NW FLOW ALF...DEEPER MSTR SHOWN ON THE 12Z INL RAOB...
H85 TEMPS IN THE -18C TO -21C RANGE AND SOME OPEN WATER ON LK SUP
HAS RESULTED IN SOME GENERALLY LGT LES IN AREAS FAVORED BY THE LLVL
WNW FLOW. OVER THE INTERIOR...SOME DIURNAL CU/SC HAVE DVLPD IN
RATHER MOIST AIRMASS WITH INCRSG SUN ANGLE CAUSING SOME LLVL
DESTABILIZATION. BTWN THE SHRTWV MOVING THRU THE UPR LKS EARLY THIS
AFTN AND ANOTHER STRONGER DISTURBANCE STRETCHING FM NEAR LK WINNIPEG
INTO THE NRN PLAINS/ACCOMPANYING -SN MOVING THRU THE DAKOTAS...
SHRTWV RDG/AXIS OF DRIER MID LVL AIR IS BRINGING GENERALLY MOSUNNY
WX TO MUCH OF MN EXCEPT THE ARROWHEAD. YET ANOTHER SHRTWV IS
DROPPING SWD FM THE NW TERRITORIES OF CANADA INTO NRN SASKATCHEWAN/
MANITOBA.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LES TRENDS AND TEMPS
ASSOCIATED WITH THE STEADY PARADE OF DISTURBANCES EMBEDDED IN NW
FLOW ALF.
TNGT...WITH APRCH AND PASSAGE OF SHRTWV RDG LATER THIS AFTN AND THIS
EVNG/ACCOMPANYING DEEP LYR QVECTOR DVGC AND SUBSIDENCE...EXPECT
LINGERING LES TO AT LEAST DIMINISH IN INTENSITY/COVERAGE FOR A TIME.
BUT AS SHRTWV NOW MOVING INTO THE NRN PLAINS SHIFTS TO THE SE
TNGT...AREA OF ACCOMPANYING DEEP LYR QVECTOR CNVGC/MORE MSTR AND SFC
COLD FNT ARE FCST TO IMPACT THE AREA MAINLY AFT MIDNGT. ALTHOUGH ALL
MODELS SHOW THE ACCOMPANYING SYNOPTIC SCALE PCPN PASSING TO THE S OF
THE CWA CLOSER TO CORE OF UPR DVGC ON CYC SIDE OF H3 JET MAX...
EXPECT AN INCRS IN LES COVERAGE NEAR LK SUP OVERNGT. TEMPS COULD
FALL OFF QUICKLY THIS EVNG OVER AT LEAST THE INTERIOR NEAR THE WI
BORDER AS AXIS OF DRIER AIR AT LEAST BRIEFLY MOVES OVHD BEFORE
THICKER CLDS ASSOCIATED WITH DISTURBANCE NEAR LK WINNIPEG ARRIVE
LATER.
TUE...WHILE THERE MAY BE SOME MID LVL DRYING/SUBSIDENCE EARLY ON TUE
WITH A PERIOD OF QVECTOR DVGC FOLLOWING THE DEPARTING DISTURBANCE...
SHRTWV NOW DROPPING S INTO SASKATCHEWAN/MANITOBA IS FCST TO BRING A
RETRUN OF MORE DYNAMIC SUPPORT/SOME DEEPER MSTR BY THE AFTN...
ESPECIALLY OVER THE NE HALF OF THE CWA. SO EXPECT INCRSG LES POPS
AGAIN IN THE WNW WIND SN BELTS NEAR THE LK. GIVEN H85 TEMPS FALLING
AOB -25C BY LATE IN THE DAY CAUSING THE NEAR ELIMINATION OF THE DGZ
AS WELL AS CONSIDERABLE ICE COVER OVER LK SUP...EXPECT SN AMOUNTS TO
BE RELATIVELY LIGHT. TUE WL BE ANOTHER UNSEASONABLY COLD DAY. TENDED
TOWARD THE LO END OF GUIDANCE FOR MAX TEMPS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 406 PM EST MON FEB 24 2014
THE FIRST IN A SERIES OF UPPER LEVEL DISTURBANCES THAT WILL BRING
COLDER AIR TO THE AREA WILL BE SWEEPING ACROSS UPPER MICHIGAN
TUESDAY AFTERNOON AND EARLY TUESDAY EVENING. THIS SHORTWAVE WILL
USHER IN SLIGHTLY COLDER 850MB TEMPS ON TUESDAY NIGHT (-28C) AND
WITH WINDS OUT OF THE NORTHWEST...WOULD EXPECT AT LEAST A BRIEF
PERIOD OF LIGHT TO MODERATE LAKE EFFECT SNOW IN THE NORTHWEST WINDS
SNOW BELTS DURING THE EVENING. BUT MODELS ARE SHOWING DRY AIR ABOVE
850MB MOVING IN QUICKLY AFTER 06Z WEDNESDAY...SO THAT SHOULD CUT OUT
THE INTENSITY HEADING INTO THE OVERNIGHT HOURS. GETTING A GOOD
HANDLE ON ICE COVER OVER THE WESTERN LAKE TODAY...WITH OPEN WATER
GENERALLY NORTHWEST OF A LINE FROM THE APOSTLE ISLANDS TO TERRACE
BAY ONTARIO. THAT GAP OF 30-40MI IS PLENTY TO SUPPORT LAKE EFFECT
CLOUDS AND SNOW...WHICH HAS BEEN SEEN THIS MORNING OVER WESTERN
UPPER MICHIGAN. THEREFORE...WILL CONTINUE TO SHOW LIKELY POPS IN
THE NORTHWEST WIND AREAS OVER THE WEST IN THE EVENING AND DIMINISH
SLIGHTLY OVERNIGHT WITH THE INCREASING DRY AIR AND BACKING WINDS
ASSOCIATED WITH A WEAK HIGH PRESSURE RIDGE. THE EAST IS A LITTLE
MORE COMPLICATED...SINCE THE ONLY POCKET OF OPEN WATER IS THE AREA
TO THE EAST OF THE KEWEENAW PENINSULA AND SOUTH TO MARQUETTE. WITH
THE NORTHWEST WINDS...THAT WOULD SUPPORT THE HIGHEST POPS/AMOUNTS
OVER ALGER COUNTY AND THINK FARTHER EAST INTO LUCE COUNTY (EVEN THE
EASTERN THIRD OF ALGER COUNTY) WOULD SEE LESS ACCUMULATION AND MORE
SCATTERED SNOW SHOWERS WITH THE AMOUNT OF ICE THE BANDS ORIGINATING
NORTHEAST OF ISLE ROYALE WOULD HAVE TO PASS OVER.
THE WEAK HIGH PRESSURE WILL SLIDE ACROSS THE U.P. LATE TUESDAY
NIGHT AND WEDNESDAY MORNING...AS THE NEXT SHORTWAVE AND LOW
PRESSURE SYSTEM DIVE SOUTHEAST OUT OF WESTERN ONTARIO WEDNESDAY
AFTERNOON AND ACROSS LAKE SUPERIOR AT 998MB ON WEDNESDAY EVENING.
THE BEST SNOW ASSOCIATED WITH THIS LOW AND SHORTWAVE WILL LIKELY BE
NEAR THE SURFACE LOW WITH THE LOWER LEVEL DRY AIR BEING PULL
NORTHEAST ACROSS UPPER MICHIGAN. ANY SYNOPTIC SNOW SHOULD BE LIGHT
AND ONLY CREATE A LIGHT DUSTING...MAINLY NEAR LAKE SUPERIOR. BUT
BEHIND THE LOW...EXPECT ANOTHER OPPORTUNITY FOR LAKE EFFECT SNOW IN
NORTHWEST TO NORTH-NORTHWEST WIND AREAS. THE 925MB WINDS WILL BE
FAIRLY STRONG (35KTS) BEHIND THE FRONT AND WILL LIKELY LIMIT THE
RESIDENCE TIME OVER THE 30-40MI STRETCH OF OPEN WATER. WOULD EXPECT
THIS TO LIMIT SNOWFALL AMOUNTS EVEN THOUGH DELTA-T VALUES ARE
NEARING 30-32 AND INVERSION HEIGHTS ARE BETWEEN 10-14KFT. ALTHOUGH
SNOW AMOUNTS MAY NOT BE TOO SIGNIFICANT...THINK THE PERIOD OF VERY
GUSTY NORTHWEST WINDS ON THE BACK SIDE OF THE LOW (GUSTS NEAR LAKE
SUPERIOR OF 30-40KTS NEAR LAKE SUPERIOR FROM ONTONAGON TO WHITEFISH
POINT) WILL CREATE A SIGNIFICANT CONCERN FOR WIDESPREAD BLOWING AND
DRIFTING SNOW. HAVE TRENDED WINDS UP 5-10KTS FOR THIS PERIOD WITH
THE CONSISTENCY IN THE MODELS ON THIS WINDY IDEA. WILL ALSO ADD A
MENTION OF THE POTENTIAL FOR CONSIDERABLE BLOWING AND DRIFTING SNOW
NEAR LAKE SUPERIOR IN THE HWO THAT WILL DEVELOP WEDNESDAY NIGHT
AND CONTINUE INTO THURSDAY MORNING. ADD FINE FLAKE SNOW FALLING WITH
THE BLOWING SNOW SHOULD EASILY CREATE VISIBILITIES OF 1/2MI OR
LESS IN THE KEWEENAW. THE GUSTY WINDS WILL COMBINE WITH TEMPERATURES
BELOW ZERO ON THURSDAY MORNING TO ALSO CREATE A CONCERN FOR WIND
CHILL HEADLINES FOR A GOOD PORTION OF UPPER MICHIGAN. CURRENT
FORECAST HAS WIND CHILL VALUES OF -25 TO -35 DEGREES AND WITH THE
POTENTIAL FOR BLOWING SNOW IT COULD EVENTUALLY BE TIED TOGETHER WITH
A WINTER WX ADVISORY.
ONCE AGAIN...A HIGH PRESSURE RIDGE (FROM A HIGH MOVING INTO THE
UPPER MISSISSIPPI VALLEY) WILL QUICKLY MOVE OVER UPPER MICHIGAN ON
THURSDAY AFTERNOON INTO THURSDAY NIGHT. THIS SHOULD RAPIDLY
DIMINISH WINDS OVER THE AREA DURING THE AFTERNOON. MODELS CONTINUE
TO SHOW HIGHS ONLY REACHING AROUND 0 DEGREES ON THURSDAY...WHICH
WOULD PUT SEVERAL COLD HIGH TEMPERATURE RECORDS IN JEOPARDY SINCE
MOST ARE IN THE MID SINGLE DIGITS ABOVE ZERO. FOR THE LONG PERIOD OF
RECORD SITES...MOST OF THOSE RECORDS DATE BACK TO THE LATE 1800S AND
EARLY 1900S. WOULD EXPECT SKIES TO CLEAR OUT AWAY FROM ANY LAKE
EFFECT NEAR LAKE SUPERIOR THURSDAY AFTERNOON AND CONTINUE INTO
THURSDAY NIGHT. THINK THIS WILL LEAD TO A VERY COLD NIGHT ACROSS THE
AREA AND WILL CONTINUE TO SHOW LOWS IN THE 10S TO MID 20S BELOW ZERO
(COLDEST INTERIOR COLD SPOTS).
ANOTHER SHORTWAVE WILL ROUND THE EASTERN CANADA UPPER TROUGH ON
FRIDAY AND DIVE SOUTHEAST ACROSS UPPER MICHIGAN FRIDAY NIGHT. THE
COLD AIR ASSOCIATED WITH THIS WAVE WILL LEAD TO ANOTHER DAY OF
HIGHS ABOUT 30 DEGREES BELOW NORMAL ON SATURDAY. LAKE EFFECT
POTENTIAL CONTINUES FRIDAY NIGHT INTO SATURDAY...BUT WORRIED THAT
THE VERY COLD TEMPS AND LIGHT WINDS ON THURSDAY NIGHT INTO FRIDAY
WILL LEAD TO A FAST ICE UP OF THE OPEN AREAS AND CUT OFF LAKE
EFFECT. WILL GO WITH SLIGHT AND LOW CHANCE POPS AT THIS POINT DUE TO
THE UNCERTAINTY. EXTENDED MODELS ARE SHOWING A TREND TOWARDS MORE
ZONAL FLOW AND GRADUALLY WARMING TEMPERATURES SUNDAY AND HEADING
INTO NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 643 PM EST MON FEB 24 2014
AFTER A PERIOD OF VFR CONDITIONS THIS EVENING AT KIWD AND MOSTLY
MVFR AT KCMX...ANOTHER DISTURBANCE WILL BRING AN UPTICK IN LAKE
EFFECT SHSN AND BLSN LATER TONIGHT...WITH VIS FALLING INTO THE IFR
RANGE. WHILE PREVAILING IFR CONDITIONS WILL LIKELY PERSIST AT KCMX
THRU TUE...INCREASING SUBSIDENCE IN THE AFTN MAY HELP KIWD IMPROVE
TO MVFR. AT KSAW...DOWNSLOPE WESTERLY WINDS WILL WORK TO MAINTAIN
VFR CONDITIONS INTO THE MORNING. DAYTIME HEATING WILL THEN LIKELY
RESULT IN AN MVFR CIG DEVELOPING AT KSAW WITH THE ARRIVAL OF MORE
UNSTABLE AIR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EST MON FEB 24 2014
WEST TO NORTHWEST WINDS OF 15-25KTS WILL CONTINUE TONIGHT THROUGH
TUESDAY NIGHT...BUT THEN BACK ON WEDNESDAY MORNING AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. A TIGHTENING GRADIENT AHEAD OF
THAT LOW COULD LEAD TO A FEW GALE FORCE GUSTS TO 35KTS AROUND
MID-DAY WEDNESDAY. THEN AS THE LOW DROPS SOUTHEAST ACROSS EASTERN
LAKE SUPERIOR ON WEDNESDAY EVENING...EXPECT A RAPID SWITCH AND
INCREASE IN THE WINDS FROM THE NORTHWEST AND CURRENT THOUGHT IS
THAT MUCH OF THE LAKE WILL SEE GALE FORCE GUSTS TO 35-40KTS. A HIGH
PRESSURE RIDGE WILL QUICKLY MOVE OVER THE AREA THURSDAY
AFTERNOON/NIGHT AND WEAKEN THE WINDS. ANOTHER TROUGH MOVING THROUGH
ON FRIDAY NIGHT WILL INCREASE WINDS BACK TO 15-25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
439 PM EST SUN FEB 23 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 435 PM EST SUN FEB 23 2014
THE UPPER GREAT LAKES REGION IS UNDER THE INFLUENCE OF A UPPER
LOW SPINNING OVER EASTERN ONTARIO AT THIS TIME. THIS UPPER LOW HAS
BEEN ROTATING MID LEVEL MOISTURE SOUTHEAST ACROSS THE REGION TODAY
AS SEEN IN WATER VAPOR IMAGERY AND REPRESENTED ON THE 12Z KINL
SOUNDING. WITH THE OPEN WATER OVER PORTIONS OF WESTERN LAKE
SUPERIOR...MOISTURE FROM THE UPPER LOW...AND RAP ANALYZED 850MB
TEMPS AROUND -22C...HAVE BEEN SEEING LAKE CLOUDS AND LIGHT SNOW
SHOWERS ON WEBCAMS AND SATELLITE OVER NORTHERN ONTONAGON...HOUGHTON
AND KEWEENAW COUNTIES. THERE WAS ONE STRONGER BAND THAT STRETCHED
FROM NORTHERN HOUGHTON COUNTY TO JUST NORTH OF GRAND MARAIS. WHERE
THE RADAR CAN SAMPLE IT IT WAS INDICATING SNOWFALL RATES AROUND
0.5-1 INCH AN HOUR SOUTH EAST OF STANNARD ROCK WHERE IT HAS BEEN
AIDED BY ANOTHER AREA OF OPEN WATER. AS WINDS HAVE BEEN SLOWLY
SHIFTING TO THE NORTHWEST...THIS BAND HAS BEEN SHIFTING SOUTH
THROUGH THE DAY...BUT DID GET A REPORT FROM WHITEFISH POINT OF AN
ESTIMATED 6-8 INCHES OF SNOW. WOULD EXPECT AMOUNTS THAT HIGH IN
NORTHERN LUCE COUNTY WITH THE MOVEMENT BUT THINK AMOUNTS IN THE 1-3
INCH RANGE ARE REASONABLE SINCE THIS MORNING.
AS THE UPPER TROUGH AND SURFACE LOW SHIFT EAST TONIGHT...IT WILL
SWEEP A WEAK SHORTWAVE AND SFC-850MB TROUGH SOUTHEAST ACROSS LAKE
SUPERIOR. THESE TROUGHS WILL ACT TO PROVIDE MORE LOW LEVEL MOISTURE
OVER THE REGION TONIGHT INTO MONDAY MORNING AND TURN THE LOW LEVEL
WINDS TO THE NORTHWEST. 850MB TEMPS OF -23C WILL LEAD TO PLENTY OF
OVER THE LAKE INSTABILITY WHERE THERE IS OPEN WATER (INVERSION
HEIGHTS TO 6-7KFT). THERE IS A LITTLE BIT OF AN UNCERTAINTY ON
THE ICE COVERAGE...BUT BASED OFF YESTERDAY/S MODIS IMAGE AND
LOCATION OF LAKE CLOUDS TODAY...IT APPEARS THERE IS DECENT OPEN
WATER FROM TWO HARBORS MINNESOTA TO ISLE ROYALE...THEN
EAST-NORTHEAST OF ISLE ROYALE TO NORTHERN LAKE SUPERIOR AND ALSO TO
THE EAST OF THE KEWEENAW AND TOWARDS MARQUETTE. WHERE ICE CAN BE
MADE OUT...THERE HAS BEEN DECENT MOVEMENT WITH THE WEST-NORTHWEST
WINDS OF 20-30KTS. WITH WEAKENING WINDS INCREASING THE RESIDENCE
TIME OVER THE 20-30MI AREA OF OPEN WATER OVER THE WEST
TONIGHT...THINK THAT WILL BE ENOUGH FOR LIGHT AND OCCASIONALLY
MODERATE LAKE EFFECT SNOWS TO OCCUR FROM CALUMET SOUTHWEST TO
IRONWOOD AND WILL CONTINUE TO SHOW LIKELY AND LOW DEFINITE POPS
FOR THOSE AREAS TONIGHT. NORTH OF CALUMET IS A LITTLE UNCERTAIN ONCE
WINDS TURN TO THE NORTHWEST DUE TO MORE ICE BETWEEN ISLE ROYALE AND
THUNDER BAY AND SMALLER GAPS IN THE FIRST 10-15MI SOUTHEAST FROM
ISLE ROYALE. THEREFORE...WILL HAVE THE POPS LOWER INTO THE LOW END
LIKELY CATEGORY ONCE THE WINDS TURN TO THE NORTHWEST.
OVERALL...SNOWFALL AMOUNTS SHOULD BE LIGHT AND IN THE 1-4 INCH
RANGE. GUSTY THIS EVENING (TO 35MPH)...BUT WITH THE LOW WEAKENING
AND SHIFTING EAST TONIGHT...SHOULD SEE A GRADUAL DIMINISHING TREND
TO THE WINDS. THIS WILL LEADING TO IMPROVING VISIBILITIES FROM THE
BLOWING SNOW OVER THE KEWEENAW PENINSULA. SINCE WE ARE STILL
GETTING REPORTS FROM OBS/WEBCAMS/SPOTTERS OF VISIBILITIES BELOW
1/2MI AT TIMES...DECIDED TO EXTEND THE ADVISORY UNTIL MIDNIGHT.
THIS WILL COVER THE EVENING TRAVEL PERIOD BEFORE THE WINDS DIMINISH
OVERNIGHT.
FARTHER EAST...THE MAIN AREA OF CONCERN WILL BE OVER NORTHERN
LUCE AND THEN TRANSITIONING INTO ALGER COUNTY DUE TO THE FAVORABLE
FETCH ACROSS THE OPEN WATER THAT LIKELY COVERS A DECENT PORTION OF
LSZ265. WITH NORTHWEST WINDS AND PROBABLY SOME LAND BREEZE
INFLUENCE...WOULD THINK THERE WOULD BE SOME ENHANCED LAKE EFFECT
BAND AFFECTING THE COUNTY AND GRADUALLY TRANSITIONED THE BAND
SOUTHWEST THIS EVENING TO AROUND AND JUST EAST OF MUNISING AREA
OVERNIGHT. WITH A POTENTIAL FETCH OF 80MI AND SOME UPSTREAM
MOISTENING OVER THE WESTERN LAKE...WOULDN/T BE SURPRISED IF THERE
ARE SOME LOCALIZED 4 INCH AMOUNTS ESPECIALLY IF THE BAND STALLS IN
AN AREA FOR A FEW HOURS. EAST OF THERE...THE AMOUNT OF ICE COVERAGE
WILL LIKELY LIMIT AMOUNTS AND ONLY HAVE VALUES IN THE 1 TO MAYBE 2
INCH RANGE.
WILL START TO SEE THE AFFECT OF RIDGING UPSTREAM THROUGH THE DAY
TOMORROW AS THE UPPER LOW SHIFTS EAST. THIS WILL LEAD TO INCREASING
850MB TEMPERATURES (ALONG WITH SOME DRYING AND BACKING WINDS) FROM
WEST TO EAST...ESPECIALLY IN THE AFTERNOON. THUS...WILL FOLLOW THAT
TREND FOR POPS AND SNOWFALL AMOUNTS THROUGH THE DAY. HIGHS TOMORROW
WILL BE IN THE LOW-MID TEENS OVER MUCH OF THE AREA. THIS LOOKS TO
BE THE WARMEST HIGHS FOR THE REST OF THE WORK WEEK.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 435 PM EST SUN FEB 23 2014
THE CWA WILL BE DOMINATED BY LOW WIND CHILLS...AND LIGHT TO MODERATE
LES FOR AREAS DOWNWIND OF W TO NW FLOW OVER GAPS IN THE CONSIDERABLE
LAKE ICE COVER.
MON NIGHT...THE STRONGEST 850-500 MB QVECTOR CONV AND
LOWER LEVEL WAA/ISENTROPIC LIFT ASSOCIATED WITH THE FIRST IN A SERIES
OF SHORTWAVE TROUGHS IS EXPECTED TO REMAIN WELL TO THE SOUTH THROUGH
IA INTO SRN WI AND NRN IL. WRLY FLOW LES BANDS WILL SHIFT SLIGHTLY AS
WINDS VEER TO WNW BEHIND A WEAK SFC TROUGH. WITH CONTINUED
UNCERTAINTY ON THE EXTENT OF OPEN WATER AND INVERSION HEIGHTS ONLY
AROUND 5K FT...MENTIONED LIKELY POPS BUT WITH FCST SNOWFALL AMOUNTS
ONLY OF AROUND AN INCH OR TWO.
TUE INTO TUE NIGHT...THE MODELS SUGGEST ANOTHER SHRTWV WITH AN ARCTIC
FRONT BRINGING IN EVEN COLDER AIR WILL MOVE THROUGH BY LATE TUE INTO
TUE NIGHT. WINDS WILL VEER TO THE NW PUSHING THE LIGHT LES OVER A
GRATER PORTION OF THE ERN CWA. WITH MIN TEMPS DROPPING INTO THE -4F
TO -14F RANGE...WIND CHILLS SHOULD ALSO FALL INTO THE -20 TO -30
RANGE.
WED-FRI...A STRONGER SHRTWV WILL MOVE THROUGH THE NRN LAKES AS THE
POLAR TROUGH MOVES INTO NRN ONTARIO. WINDS ARE EXPECTED TO VEER TO
THE NW TO NNW BEHIND THIS FEATURE AS 850 MB TEMPS DROP TO AROUND
-31C THU. WITH THE STRONGER NW WINDS...THE LOWEST WIND CHILLS ARE
EXPECTED THU MORNING INTO THE -25 TO -35 RANGE EVEN THOUGH THERE MAY
SOME MODIFICATION OVER THE MOSTLY FROZEN LAKE. WITH LIGHTER WINDS
AND FEW CLOUDS BY FRI AS THE ARCTIC HIGH SETTLES OVER THE
AREA...TEMPS SHOULD DROP AT LEAST INTO THE -15 TO -25 RANGE OVER
MUCH OF THE CWA...WITH SOME -30S EVEN POSSIBLE FOR TRADITIONAL COLD
SPOTS.
SAT-SUN...THERE IS GREATER UNCERTAINTY WITH ANY INDIVIDUAL SHRTWVS
BUT WITH THE POLAR TROUGH LINGERING NEAR JAMES BAY...ANOTHER BOUT OF
LOWER 850 MB TEMPS AND HIGHER WINDS MAY MOVE IN BY SAT WITH
DIMINISHING WINDS AND CONTINUED COLD ON SUN WITH THE ARCTIC RIDGE
DOMINATING THE NRN LAKES. BY THE WEEKEND...THE ICE COVER IS LIKELY
TO SOLIDIFY...REDUCING LES CHANCES/AMOUNTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1248 PM EST SUN FEB 23 2014
COLD AIR AND INCREASING MOISTURE ROTATING AROUND A LOW PRESSURE
SYSTEM NEAR HUDSON BAY WILL LEAD TO CONTINUED GUSTY WESTERLY WINDS
THIS AFTERNOON. WITH SOME OPEN WATER OVER WESTERN LAKE
SUPERIOR...LAKE EFFECT SNOW SHOWERS HAVE BEEN OCCURRING IN THE WEST
WIND SNOW BELTS AND LARGELY AFFECTING KCMX FOR MUCH OF THIS
AFTERNOON. BUT AS A WEAK TROUGH MOVES THROUGH LATE THIS AFTERNOON
AND DURING THE EVENING...EXPECT WINDS TO TURN MORE FAVORABLE FOR
LAKE EFFECT AT KIWD AND HAVE LOWER VISIBILITIES. BUT THIS TURN IN
THE WINDS COULD INFLUENCE KCMX SNOWFALL...AS THERE WILL BE MORE OF
AN ICE SHADOW DUE TO THE INCREASED ICE NEAR ISLE ROYALE. MAINLY
IMPROVED VISIBILITIES DUE TO THE WEAKENING WINDS AND IF ICE
COVERAGE IS LESS THAN EXPECTED...VISIBILITIES MAY BE LOWER THAN
EXPECTED. AN APPROACHING HIGH PRESSURE RIDGE ON MONDAY AFTERNOON
MAY LEAD TO AN IMPROVEMENT IN CONDITIONS AT KIWD/KCMX LATE IN THE
TAF PERIOD.
AT KSAW...WEST TO NORTHWEST FLOW ISN/T TOO FAVORABLE FOR LESS THAN
VFR CONDITIONS FROM LAKE EFFECT BUT WITH THE EXPECTED INCREASE IN
MOISTURE WITH THE TROUGH DID LOWER TO MVFR CEILINGS AS THE TROUGH
MOVES THROUGH. HAVE A FEELING THE DOWNSLOPING FLOW WILL LEAD TO
VALUES RIGHT ON THE EDGE OF VFR/MVFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 435 PM EST SUN FEB 23 2014
THE WEAKENING LOW NEAR HUDSON BAY WILL COMBINE WITH A HIGH PRESSURE
RIDGE MOVING THROUGH THE NORTHERN PLAINS AND MID MISSISSIPPI VALLEY
TO LEAD TO GRADUALLY DECREASING WEST TO NORTHWEST WINDS OVER LAKE
SUPERIOR TONIGHT THROUGH MONDAY NIGHT. HAVE BEEN SEEING THE GALES
PERSISTING OVER THE EASTERN PART OF LAKE SUPERIOR ON THE STANNARD
ROCK AND GRANITE ISLAND OBS THIS AFTERNOON...BUT WITH UPSTREAM OBS
GENERALLY IN THE 30KT RANGE...WOULD EXPECT THE EASTERN SITES TO
COME DOWN SHORTLY. THUS...WILL ALLOW THE GALE WARNING OVER THE
EASTERN LAKE TO EXPIRE AT 00Z AND HAVE ALREADY CANCELLED THE
WESTERN LAKE. EVEN WITH THIS DIMINISHMENT...THERE WILL LIKELY BE
ENOUGH OF A GRADIENT TO KEEP WINDS IN THE 15 TO 30KT RANGE FOR MUCH
OF THE FORECAST PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ001-
003.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ265>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
338 AM EST SUN FEB 23 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 410 PM EST SAT FEB 22 2014
THE LOW THAT BROUGHT THE SNOW AND MIXED PRECIPITATION TO THE AREA
THURSDAY EVENING INTO FRIDAY HAS BECOME STATIONARY NEAR CAPE
HENRIETTA MARIA BETWEEN HUDSON BAY AND JAMES BAY. THIS NEARLY
STATIONARY LOW WILL COMBINE WITH A 1028MB HIGH PRESSURE RIDGE
SLIDING SOUTHEAST FROM A HIGH IN THE CANADIAN ROCKIES AND INTO THE
NORTHERN PLAINS AND MID MISSISSIPPI VALLEY TO CREATE A TIGHT
PRESSURE GRADIENT OVER THE UPPER GREAT LAKES THROUGH TONIGHT AND
PART OF SUNDAY. THUS...THE WINDS AND RESULTING BLOWING SNOW (MAINLY
OVER THE KEWEENAW) WILL BE THE PRIMARY CONCERN FOR TONIGHT INTO
SUNDAY.
WITH THIS TIGHT PRESSURE GRADIENT REMAINING IN PLACE FOR MUCH OF
THE NIGHT AND COLDER AIR ALOFT SPILLING INTO THE REGION...WOULD
EXPECT THE GUSTY CONDITIONS TO REMAIN THROUGH AT LEAST THE FIRST
HALF OF THE NIGHT. EVEN OVER THE LAST COUPLE OF HOURS...WINDS AT
KCMX HAVE FALLEN TO ONLY 35-40MPH. UPSTREAM AT ISLE ROYALE...WINDS
ARE STILL GUSTING TO SIMILAR VALUES AND WITH MODELS SHOWING GUSTS
TO 35KTS THROUGH BETWEEN 06-12Z...WILL FOLLOW THAT IDEA FOR THE
KEWEENAW TONIGHT. SINCE MUCH OF THE SNOW HAS DIMINISHED AT
KCMX...SEEING MORE OF A SPOTTY NATURE TO THE WORST VISIBILITIES ON
WEBCAMS AND THE KCMX OBS. THUS...THINKING THAT THE GOING ENDING
TIME FOR THE BLIZZARD WARNING IS REASONABLE AND THE EVENING SHIFT
WILL BE ABLE TO LET IT EXPIRE. THE QUESTION IS WHETHER A ADVISORY
WILL BE NEEDED TO COVER THE LINGERING BLOWING/DRIFTING SNOW OR IF
IT COULD BE COVERED BY AN SPS. ALMOST LEANING TOWARDS AN SPS...BUT
WILL ALLOW EVENING SHIFT TO SEE HOW VISIBILITIES ARE DOING OVER THE
NEXT FEW HOURS AND THEN DECIDE. WITH THE CLEARING SKIES AND LITTLE
VSBY RESTRICTIONS ON WEBCAMS IN GOGEBIC/ONTONAGON COUNTIES...HAVE
CANCELLED THE EXISTING WINTER WX ADVISORY FOR THERE.
OVER THE REST OF THE AREA...A SHORTWAVE THAT WAS OVER WESTERN
ONTARIO THIS MORNING HAS SHIFTED EAST-SOUTHEAST AND IS MOVING
ACROSS FAR NORTHERN LAKE SUPERIOR. WITH THIS TRACK...IT LOOKS LIKE
THE DEEPER MOISTURE WILL HOLD OFF MOVING SOUTH OVER THE CWA UNTIL
LATE TONIGHT AND ESPECIALLY INTO SUNDAY AFTERNOON. THUS...THINK
MUCH OF THE CLOUDS AND SNOW CHANCES FOR MUCH OF THE SHORT TERM
PERIOD WILL DEPEND ON LAKE EFFECT. WITH RAP ANALYZED 850MB TEMPS
AROUND -17C AND MODELS SHOWING THAT FALLING TO -23C BY 00Z
MONDAY...THERE IS PLENTY OF OVER LAKE INSTABILITY IF WATER IS
PRESENT ON LAKE SUPERIOR. TODAY/S MODIS IMAGE SHOWS SOME OPEN WATER
THAT HAS DEVELOPED OFF THE ARROWHEAD OF MINNESOTA AND ALSO TO THE
EAST OF THE KEWEENAW. THEREFORE...WITH THE WESTERLY 925MB WINDS
EXPECTED TONIGHT...HAVE FOCUSED CLOUD COVER AND SLIGHT TO LOW
CHANCE POPS IN THE AREAS DOWNWIND OF THOSE PATCHES OF OPEN WATER.
THIS MAINLY AFFECTS THE KEWEENAW PENINSULA. WITH WINDS SHIFTING A
LITTLE MORE TO THE NORTHWEST ON SUNDAY AFTERNOON...HAVE SLOWLY
TRANSITIONED POPS TOWARDS THAT DIRECTION. DIDN/T PUT MUCH FOR
SNOWFALL AMOUNTS (ONLY AROUND AN INCH OR SO) INTO THE FORECAST DUE
TO THE STRENGTH OF THE WINDS LIKELY LIMITING FETCH ACROSS THE OPEN
WATER.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 338 AM EST SUN FEB 23 2014
BIGGEST ISSUES IN THE LONG TERM ARE WITH THE RETURN OF EXTREMELY
COLD AIR AND LIGHT-MODERATE LES.
FOR LES CONSIDERATIONS...SOME BREAK UP OF LAKE SUPERIOR ICE HAS
OCCURRED OVER THE LAST COUPLE OF DAYS WITH THE STRONG WLY WINDS.
THIS WILL ALLOW FOR INCREASED LES ACTIVITY OVER THE NEXT WEEK.
MON WILL SEE DIMINISHING NW FLOW LES POPS AS A RIDGE PASSES OVERHEAD
AND 850MB TEMPS DECREASE FROM THE MID 20S TO MID TEENS BELOW ZERO.
WILL SEE SEVERAL PIECES OF ENERGY MOVING THROUGH THE REGION OVER THE
NEXT WEEK...EACH ONE PULLING DOWN MORE COLD AIR UNTIL A POLAR LOW
MOVES TO NEAR JAMES BAY BY 12Z THU. 850MB TEMPS AOB -30C MOVE INTO
THE AREA THU NIGHT INTO THE WEEKEND. THIS WILL LEAD TO VERY COLD
TEMPERATURES YET AGAIN. THU LOOKS TO SEE THE COLDEST HIGH TEMPS IN
THE SINGLE DIGITS AND TUE NIGHT SHOULD BE COLDEST. WILL LIKELY BREAK
RECORD LOW HIGH TEMPERATURES THIS WEEK...AND POSSIBLY SOME DAILY
RECORD LOWS.
SOME LIGHT TO MODERATE SNOWFALL IS POSSIBLE AT TIMES THROUGH THE
NEXT WEEK...BUT GREATER OF THE CONFIDENCE VERY UNCERTAIN SO DID NOT
MAKE SIGNIFICANT CHANGES TO THE PREVIOUS FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM EST SAT FEB 22 2014
WITH WEAKENING LOW PRES REMAINING IN THE VCNTY OF FAR NRN
ONTARIO/JAMES BAY AND HIGH PRES CONTINUING TO RIDGE SE FROM THE SRN
CANADIAN ROCKIES TO THE MID MISSISSIPPI VALLEY...BLUSTERY WESTERLY
WINDS WILL CONTINUE FOR MUCH OF THIS FCST PERIOD AT
KIWD/KCMX/KSAW...BUT ESPECIALLY AT THE MORE EXPOSED KCMX SITE. WITH
WINDS GUSTING OVER 30KT AT KCMX OVERNIGHT THRU THE AFTN...BLSN WILL
LIKELY KEEP PREVAILING VIS IN THE LIFR CATEGORY. EXPECT SOME
FLUCTUATION WITH VIS IMPROVING TO IFR FOR BRIEF PERIODS AS WELL AS
FALLING TO VLIFR. WITH THE WESTERLY WINDS AND SOME GAPS IN THE ICE
OVER WESTERN LAKE SUPERIOR...THERE WILL BE OCNL -SHSN AT
KCMX...WHICH WILL ASSIST THE LOWER VISIBILITIES. DISTURBANCE SHOULD
INCREASE -SHSN FREQUENCY TODAY...AND THIS MAY RESULT IN VIS FALLING
MORE FREQUENTLY TO BLO 1/2SM. THERE SHOULD BE SOME IMPROVEMENT TO
IFR THIS EVENING AS WINDS VEER MORE TO THE NW AND DIMINISH SOME...
RESULTING IN LESS BLSN.
AT KIWD/KSAW...SRN EDGE OF STRATOCU/MVFR CIGS WILL BE NEAR KIWD
OVERNIGHT WHILE DOWNSLOPE WESTERLY WINDS WILL HELP TO MAINTAIN VFR
CONDITIONS AT KSAW. DEEPER MOISTURE/DISTURBANCE ROTATING INTO THE
AREA DURING THE DAY TODAY SHOULD PRODUCE A MORE SOLID MVFR CLOUD
DECK AS WELL AS SOME -SHSN/FLURRIES. AFTER THE STRONG WINDS OF
RECENT DAYS...THERE MAY BE SUFFICIENT OPEN WATER OVER WRN LAKE
SUPERIOR TO SUPPORT IFR CONDITIONS IN -SHSN AT KIWD THIS EVENING AS
WINDS VEER MORE TO THE NW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 334 AM EST SUN FEB 23 2014
LOW PRESSURE OVER JAMES BAY TODAY WILL EXIT INTO QUEBEC TONIGHT.
EXPECT HIGH PRESSURE ACROSS SASKATCHEWAN TODAY TO SINK ACROSS THE
PLAINS STATES TUESDAY NIGHT INTO WEDNESDAY...ALLOWING A RIDGE TO
PASS OVER LAKE SUPERIOR TUESDAY AND TUESDAY NIGHT. W GALES 35-40KTS
WILL CONTINUE TODAY OVER PORTIONS OF MAINLY CENTRAL AND E LAKE
SUPERIOR IN BETWEEN THE EXITING LOW...AND NEARING HIGH PRESSURE FROM
THE NW.
LOW PRESSURE OVER NW MANITOBA WEDNESDAY MORNING WILL SWING ACROSS
LAKE SUPERIOR WEDNESDAY AFTERNOON AND EVENING BEFORE EXITING TO THE
NEW ENGLAND STATES. HIGH PRESSURE OVER CENTRAL CANADA AND ND
THURSDAY MORNING WILL BROADEN ACROSS THE UPPER GREAT LAKES THURSDAY
NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR MIZ001-
003.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
LSZ240>246-263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
335 AM EST SUN FEB 23 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 410 PM EST SAT FEB 22 2014
THE LOW THAT BROUGHT THE SNOW AND MIXED PRECIPITATION TO THE AREA
THURSDAY EVENING INTO FRIDAY HAS BECOME STATIONARY NEAR CAPE
HENRIETTA MARIA BETWEEN HUDSON BAY AND JAMES BAY. THIS NEARLY
STATIONARY LOW WILL COMBINE WITH A 1028MB HIGH PRESSURE RIDGE
SLIDING SOUTHEAST FROM A HIGH IN THE CANADIAN ROCKIES AND INTO THE
NORTHERN PLAINS AND MID MISSISSIPPI VALLEY TO CREATE A TIGHT
PRESSURE GRADIENT OVER THE UPPER GREAT LAKES THROUGH TONIGHT AND
PART OF SUNDAY. THUS...THE WINDS AND RESULTING BLOWING SNOW (MAINLY
OVER THE KEWEENAW) WILL BE THE PRIMARY CONCERN FOR TONIGHT INTO
SUNDAY.
WITH THIS TIGHT PRESSURE GRADIENT REMAINING IN PLACE FOR MUCH OF
THE NIGHT AND COLDER AIR ALOFT SPILLING INTO THE REGION...WOULD
EXPECT THE GUSTY CONDITIONS TO REMAIN THROUGH AT LEAST THE FIRST
HALF OF THE NIGHT. EVEN OVER THE LAST COUPLE OF HOURS...WINDS AT
KCMX HAVE FALLEN TO ONLY 35-40MPH. UPSTREAM AT ISLE ROYALE...WINDS
ARE STILL GUSTING TO SIMILAR VALUES AND WITH MODELS SHOWING GUSTS
TO 35KTS THROUGH BETWEEN 06-12Z...WILL FOLLOW THAT IDEA FOR THE
KEWEENAW TONIGHT. SINCE MUCH OF THE SNOW HAS DIMINISHED AT
KCMX...SEEING MORE OF A SPOTTY NATURE TO THE WORST VISIBILITIES ON
WEBCAMS AND THE KCMX OBS. THUS...THINKING THAT THE GOING ENDING
TIME FOR THE BLIZZARD WARNING IS REASONABLE AND THE EVENING SHIFT
WILL BE ABLE TO LET IT EXPIRE. THE QUESTION IS WHETHER A ADVISORY
WILL BE NEEDED TO COVER THE LINGERING BLOWING/DRIFTING SNOW OR IF
IT COULD BE COVERED BY AN SPS. ALMOST LEANING TOWARDS AN SPS...BUT
WILL ALLOW EVENING SHIFT TO SEE HOW VISIBILITIES ARE DOING OVER THE
NEXT FEW HOURS AND THEN DECIDE. WITH THE CLEARING SKIES AND LITTLE
VSBY RESTRICTIONS ON WEBCAMS IN GOGEBIC/ONTONAGON COUNTIES...HAVE
CANCELLED THE EXISTING WINTER WX ADVISORY FOR THERE.
OVER THE REST OF THE AREA...A SHORTWAVE THAT WAS OVER WESTERN
ONTARIO THIS MORNING HAS SHIFTED EAST-SOUTHEAST AND IS MOVING
ACROSS FAR NORTHERN LAKE SUPERIOR. WITH THIS TRACK...IT LOOKS LIKE
THE DEEPER MOISTURE WILL HOLD OFF MOVING SOUTH OVER THE CWA UNTIL
LATE TONIGHT AND ESPECIALLY INTO SUNDAY AFTERNOON. THUS...THINK
MUCH OF THE CLOUDS AND SNOW CHANCES FOR MUCH OF THE SHORT TERM
PERIOD WILL DEPEND ON LAKE EFFECT. WITH RAP ANALYZED 850MB TEMPS
AROUND -17C AND MODELS SHOWING THAT FALLING TO -23C BY 00Z
MONDAY...THERE IS PLENTY OF OVER LAKE INSTABILITY IF WATER IS
PRESENT ON LAKE SUPERIOR. TODAY/S MODIS IMAGE SHOWS SOME OPEN WATER
THAT HAS DEVELOPED OFF THE ARROWHEAD OF MINNESOTA AND ALSO TO THE
EAST OF THE KEWEENAW. THEREFORE...WITH THE WESTERLY 925MB WINDS
EXPECTED TONIGHT...HAVE FOCUSED CLOUD COVER AND SLIGHT TO LOW
CHANCE POPS IN THE AREAS DOWNWIND OF THOSE PATCHES OF OPEN WATER.
THIS MAINLY AFFECTS THE KEWEENAW PENINSULA. WITH WINDS SHIFTING A
LITTLE MORE TO THE NORTHWEST ON SUNDAY AFTERNOON...HAVE SLOWLY
TRANSITIONED POPS TOWARDS THAT DIRECTION. DIDN/T PUT MUCH FOR
SNOWFALL AMOUNTS (ONLY AROUND AN INCH OR SO) INTO THE FORECAST DUE
TO THE STRENGTH OF THE WINDS LIKELY LIMITING FETCH ACROSS THE OPEN
WATER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 410 PM EST SAT FEB 22 2014
NO MAJOR CHANGES EXPECTED TO THE LONG TERM FORECAST WITH MUCH BELOW
NORMAL TEMPERATURES AND OCCASIONAL LIGHT SNOW CLOSE TO LAKE
SUPERIOR. WITH THE ARCTIC AIRMASS ONCE AGAIN BUILDING ACROSS HUDSON
BAY...THE COLDEST TEMPERATURES STILL LOOK TO BE WED-FRI WITH TEMPS
STRUGGLING TO RISE ABOVE ZERO ONCE AGAIN.
AS FOR THE DETAILS...THE DEEP LOW PRESSURE OVER JAMES BAY WILL
CONTINUE TO FILL SUNDAY NIGHT THEN FINALLY MOVE EAST BY MONDAY IN
RESPONSE TO A UPPER SHORT WAVE ROTATING AROUND THE UPPER LOW AND
THROUGH THE REGION. THIS WILL ALLOW PBL WINDS TO VEER TO THE NW
SUNDAY NIGHT. THIS VEERING OF WIND COMBINED WITH WEAK UPWARD MOTION
ASSOCIATED WITH THE UPPER SHORT WAVE AND DEEPER MOISTURE SHOULD
ALLOW FOR SOME LAKE EFFECT SNOW TO SPREAD A LITTLE FURTHER WEST
PERHAPS TO THE ALGER/MARQUETTE COUNTY BORDER. IN ADDITION...LES
SHOULD INCREASE ACROSS THE ENTIRE AREA NEAR LAKE SUPERIOR BUT THIS
IS HIGHLY DEPENDENT ON THE FLUXES OVER THE SEMI-OPEN AREAS OF LAKE
SUPERIOR. ONE WOULD THINK THAT WITH THE WIND OVER THE PAST FEW DAYS
THAT THE ICE ON THE LAKE HAS BROKEN UP SOME. IN FACT...TODAY/S MODIS
IMAGERY INDICATES THAT SEVERAL LARGER BREAKS HAVE OPENED ACROSS THE
WESTERN LAKE AS WELL AS EAST OF THE KEWEENAW. IN FACT...WOULD NOT BE
SHOCKED TO SEE A LITTLE MINI BAND OF ENHANCED LES JUST EAST OF THE
KEWEENAW ORIENTED INTO FAR WESTERN ALGER COUNTY...ESPECIALLY IF WE
CAN SEE ENHANCED LAKE BREEZE CONVERGENCE AS THE WINDS VEER TO NW.
FOR NOW...WILL RAISE POPS TO 50 PCT ACROSS ALL OF ALGER INTO LUCE
COUNTIES AND RAISE POPS TO CHC CATEGORY IN ERN MQT COUNTY. BEHIND
THIS SHORT WAVE...LIGHT LES WILL CONTINUE IN THE KEWEENAW AND INTO
ALGER/LUCE COUNTIES WITH NORTHWESTERLY CYCLONIC FLOW. ONCE
AGAIN...IT IS STILL UNCLEAR IF FLUXES WILL INCREASE ENOUGH TO
GENERATE LES OFF THE LAKE. AS SUCH...WILL CONTINUE WITH JUST CHANCE
POPS. WINDS BACK TO WNW TUE AHEAD OF A WEAK SFC TROUGH...WHICH
SHOULD ALLOW ANY LES TO SHIFT OFFSHORE EXCEPT FOR THE KEWEENAW.
THE EXTENDED PERIOD...WED-SAT...CONTINUES TO LOOK EXTREMELY COLD.
THE 12Z NWP CONTINUES TO BE IN VERY GOOD AGREEMENT IN SHOWING THE
ARCTIC FRONT MOVING THROUGH THE UPPER GREAT LAKES WED NIGHT INTO THU
MORNING...OPENING THE DOOR FOR ARCTIC AIR TO MOVE ACROSS THE REGION.
MODELS STILL SHOW 850MB TEMPS DROPPING TO -30 TO -34C BY THU EVENING
WHICH WILL CAUSE TEMPS TO STRUGGLE TO RISE ABOVE ZERO DURING THE
DAY. SFC HIGH PRESSURE IS FCST TO QUICKLY BUILD ACROSS THE AREA THU
NIGHT WHICH SHOULD ALLOW FOR EXCELLENT RADIATIVE COOLING...THUS
DROPPING SFC TEMPS TO -20F OR LOWER. IF THE SKIES CLEAR AND WINDS GO
LIGHT...THIS COULD BE ONE OF THOSE SITUATIONS SIMILAR TO EARLY MARCH
2003 WHERE NWS MQT SAW A MIN TEMP OF -31F. FOR NOW...WILL GO WITH
LOWS FRIDAY MORNING -20 TO -25 BELOW. PERHAPS SOME MODERATION IN
TEMPS BY SATURDAY WITH SLIGHT 850MB WARMING...BUT THE WINDS WILL
ALSO BE INCREASING AS THE ARCTIC HIGH STRENGTHENS LEADING TO A
TIGHTENING PRES GRADIENT ACROSS THE AREA. AS SUCH...APPARENT TEMPS
WILL NOT FEEL MUCH DIFFERENT INTO THE WEEKEND. JUST TO NOTE...THE
LATEST CFS /CLIMATE FORECAST SYSTEM/ GUIDANCE SHOWS MUCH OF MARCH
WITH BELOW NORMAL TEMPERATURES...
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM EST SAT FEB 22 2014
WITH WEAKENING LOW PRES REMAINING IN THE VCNTY OF FAR NRN
ONTARIO/JAMES BAY AND HIGH PRES CONTINUING TO RIDGE SE FROM THE SRN
CANADIAN ROCKIES TO THE MID MISSISSIPPI VALLEY...BLUSTERY WESTERLY
WINDS WILL CONTINUE FOR MUCH OF THIS FCST PERIOD AT
KIWD/KCMX/KSAW...BUT ESPECIALLY AT THE MORE EXPOSED KCMX SITE. WITH
WINDS GUSTING OVER 30KT AT KCMX OVERNIGHT THRU THE AFTN...BLSN WILL
LIKELY KEEP PREVAILING VIS IN THE LIFR CATEGORY. EXPECT SOME
FLUCTUATION WITH VIS IMPROVING TO IFR FOR BRIEF PERIODS AS WELL AS
FALLING TO VLIFR. WITH THE WESTERLY WINDS AND SOME GAPS IN THE ICE
OVER WESTERN LAKE SUPERIOR...THERE WILL BE OCNL -SHSN AT
KCMX...WHICH WILL ASSIST THE LOWER VISIBILITIES. DISTURBANCE SHOULD
INCREASE -SHSN FREQUENCY TODAY...AND THIS MAY RESULT IN VIS FALLING
MORE FREQUENTLY TO BLO 1/2SM. THERE SHOULD BE SOME IMPROVEMENT TO
IFR THIS EVENING AS WINDS VEER MORE TO THE NW AND DIMINISH SOME...
RESULTING IN LESS BLSN.
AT KIWD/KSAW...SRN EDGE OF STRATOCU/MVFR CIGS WILL BE NEAR KIWD
OVERNIGHT WHILE DOWNSLOPE WESTERLY WINDS WILL HELP TO MAINTAIN VFR
CONDITIONS AT KSAW. DEEPER MOISTURE/DISTURBANCE ROTATING INTO THE
AREA DURING THE DAY TODAY SHOULD PRODUCE A MORE SOLID MVFR CLOUD
DECK AS WELL AS SOME -SHSN/FLURRIES. AFTER THE STRONG WINDS OF
RECENT DAYS...THERE MAY BE SUFFICIENT OPEN WATER OVER WRN LAKE
SUPERIOR TO SUPPORT IFR CONDITIONS IN -SHSN AT KIWD THIS EVENING AS
WINDS VEER MORE TO THE NW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 334 AM EST SUN FEB 23 2014
LOW PRESSURE OVER JAMES BAY TODAY WILL EXIT INTO QUEBEC TONIGHT.
EXPECT HIGH PRESSURE ACROSS SASKATCHEWAN TODAY TO SINK ACROSS THE
PLAINS STATES TUESDAY NIGHT INTO WEDNESDAY...ALLOWING A RIDGE TO
PASS OVER LAKE SUPERIOR TUESDAY AND TUESDAY NIGHT. W GALES 35-40KTS
WILL CONTINUE TODAY OVER PORTIONS OF MAINLY CENTRAL AND E LAKE
SUPERIOR IN BETWEEN THE EXITING LOW...AND NEARING HIGH PRESSURE FROM
THE NW.
LOW PRESSURE OVER NW MANITOBA WEDNESDAY MORNING WILL SWING ACROSS
LAKE SUPERIOR WEDNESDAY AFTERNOON AND EVENING BEFORE EXITING TO THE
NEW ENGLAND STATES. HIGH PRESSURE OVER CENTRAL CANADA AND ND
THURSDAY MORNING WILL BROADEN ACROSS THE UPPER GREAT LAKES THURSDAY
NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR MIZ001-
003.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
LSZ240>246-263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...MRD
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1153 PM EST SAT FEB 22 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 410 PM EST SAT FEB 22 2014
THE LOW THAT BROUGHT THE SNOW AND MIXED PRECIPITATION TO THE AREA
THURSDAY EVENING INTO FRIDAY HAS BECOME STATIONARY NEAR CAPE
HENRIETTA MARIA BETWEEN HUDSON BAY AND JAMES BAY. THIS NEARLY
STATIONARY LOW WILL COMBINE WITH A 1028MB HIGH PRESSURE RIDGE
SLIDING SOUTHEAST FROM A HIGH IN THE CANADIAN ROCKIES AND INTO THE
NORTHERN PLAINS AND MID MISSISSIPPI VALLEY TO CREATE A TIGHT
PRESSURE GRADIENT OVER THE UPPER GREAT LAKES THROUGH TONIGHT AND
PART OF SUNDAY. THUS...THE WINDS AND RESULTING BLOWING SNOW (MAINLY
OVER THE KEWEENAW) WILL BE THE PRIMARY CONCERN FOR TONIGHT INTO
SUNDAY.
WITH THIS TIGHT PRESSURE GRADIENT REMAINING IN PLACE FOR MUCH OF
THE NIGHT AND COLDER AIR ALOFT SPILLING INTO THE REGION...WOULD
EXPECT THE GUSTY CONDITIONS TO REMAIN THROUGH AT LEAST THE FIRST
HALF OF THE NIGHT. EVEN OVER THE LAST COUPLE OF HOURS...WINDS AT
KCMX HAVE FALLEN TO ONLY 35-40MPH. UPSTREAM AT ISLE ROYALE...WINDS
ARE STILL GUSTING TO SIMILAR VALUES AND WITH MODELS SHOWING GUSTS
TO 35KTS THROUGH BETWEEN 06-12Z...WILL FOLLOW THAT IDEA FOR THE
KEWEENAW TONIGHT. SINCE MUCH OF THE SNOW HAS DIMINISHED AT
KCMX...SEEING MORE OF A SPOTTY NATURE TO THE WORST VISIBILITIES ON
WEBCAMS AND THE KCMX OBS. THUS...THINKING THAT THE GOING ENDING
TIME FOR THE BLIZZARD WARNING IS REASONABLE AND THE EVENING SHIFT
WILL BE ABLE TO LET IT EXPIRE. THE QUESTION IS WHETHER A ADVISORY
WILL BE NEEDED TO COVER THE LINGERING BLOWING/DRIFTING SNOW OR IF
IT COULD BE COVERED BY AN SPS. ALMOST LEANING TOWARDS AN SPS...BUT
WILL ALLOW EVENING SHIFT TO SEE HOW VISIBILITIES ARE DOING OVER THE
NEXT FEW HOURS AND THEN DECIDE. WITH THE CLEARING SKIES AND LITTLE
VSBY RESTRICTIONS ON WEBCAMS IN GOGEBIC/ONTONAGON COUNTIES...HAVE
CANCELLED THE EXISTING WINTER WX ADVISORY FOR THERE.
OVER THE REST OF THE AREA...A SHORTWAVE THAT WAS OVER WESTERN
ONTARIO THIS MORNING HAS SHIFTED EAST-SOUTHEAST AND IS MOVING
ACROSS FAR NORTHERN LAKE SUPERIOR. WITH THIS TRACK...IT LOOKS LIKE
THE DEEPER MOISTURE WILL HOLD OFF MOVING SOUTH OVER THE CWA UNTIL
LATE TONIGHT AND ESPECIALLY INTO SUNDAY AFTERNOON. THUS...THINK
MUCH OF THE CLOUDS AND SNOW CHANCES FOR MUCH OF THE SHORT TERM
PERIOD WILL DEPEND ON LAKE EFFECT. WITH RAP ANALYZED 850MB TEMPS
AROUND -17C AND MODELS SHOWING THAT FALLING TO -23C BY 00Z
MONDAY...THERE IS PLENTY OF OVER LAKE INSTABILITY IF WATER IS
PRESENT ON LAKE SUPERIOR. TODAY/S MODIS IMAGE SHOWS SOME OPEN WATER
THAT HAS DEVELOPED OFF THE ARROWHEAD OF MINNESOTA AND ALSO TO THE
EAST OF THE KEWEENAW. THEREFORE...WITH THE WESTERLY 925MB WINDS
EXPECTED TONIGHT...HAVE FOCUSED CLOUD COVER AND SLIGHT TO LOW
CHANCE POPS IN THE AREAS DOWNWIND OF THOSE PATCHES OF OPEN WATER.
THIS MAINLY AFFECTS THE KEWEENAW PENINSULA. WITH WINDS SHIFTING A
LITTLE MORE TO THE NORTHWEST ON SUNDAY AFTERNOON...HAVE SLOWLY
TRANSITIONED POPS TOWARDS THAT DIRECTION. DIDN/T PUT MUCH FOR
SNOWFALL AMOUNTS (ONLY AROUND AN INCH OR SO) INTO THE FORECAST DUE
TO THE STRENGTH OF THE WINDS LIKELY LIMITING FETCH ACROSS THE OPEN
WATER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 410 PM EST SAT FEB 22 2014
NO MAJOR CHANGES EXPECTED TO THE LONG TERM FORECAST WITH MUCH BELOW
NORMAL TEMPERATURES AND OCCASIONAL LIGHT SNOW CLOSE TO LAKE
SUPERIOR. WITH THE ARCTIC AIRMASS ONCE AGAIN BUILDING ACROSS HUDSON
BAY...THE COLDEST TEMPERATURES STILL LOOK TO BE WED-FRI WITH TEMPS
STRUGGLING TO RISE ABOVE ZERO ONCE AGAIN.
AS FOR THE DETAILS...THE DEEP LOW PRESSURE OVER JAMES BAY WILL
CONTINUE TO FILL SUNDAY NIGHT THEN FINALLY MOVE EAST BY MONDAY IN
RESPONSE TO A UPPER SHORT WAVE ROTATING AROUND THE UPPER LOW AND
THROUGH THE REGION. THIS WILL ALLOW PBL WINDS TO VEER TO THE NW
SUNDAY NIGHT. THIS VEERING OF WIND COMBINED WITH WEAK UPWARD MOTION
ASSOCIATED WITH THE UPPER SHORT WAVE AND DEEPER MOISTURE SHOULD
ALLOW FOR SOME LAKE EFFECT SNOW TO SPREAD A LITTLE FURTHER WEST
PERHAPS TO THE ALGER/MARQUETTE COUNTY BORDER. IN ADDITION...LES
SHOULD INCREASE ACROSS THE ENTIRE AREA NEAR LAKE SUPERIOR BUT THIS
IS HIGHLY DEPENDENT ON THE FLUXES OVER THE SEMI-OPEN AREAS OF LAKE
SUPERIOR. ONE WOULD THINK THAT WITH THE WIND OVER THE PAST FEW DAYS
THAT THE ICE ON THE LAKE HAS BROKEN UP SOME. IN FACT...TODAY/S MODIS
IMAGERY INDICATES THAT SEVERAL LARGER BREAKS HAVE OPENED ACROSS THE
WESTERN LAKE AS WELL AS EAST OF THE KEWEENAW. IN FACT...WOULD NOT BE
SHOCKED TO SEE A LITTLE MINI BAND OF ENHANCED LES JUST EAST OF THE
KEWEENAW ORIENTED INTO FAR WESTERN ALGER COUNTY...ESPECIALLY IF WE
CAN SEE ENHANCED LAKE BREEZE CONVERGENCE AS THE WINDS VEER TO NW.
FOR NOW...WILL RAISE POPS TO 50 PCT ACROSS ALL OF ALGER INTO LUCE
COUNTIES AND RAISE POPS TO CHC CATEGORY IN ERN MQT COUNTY. BEHIND
THIS SHORT WAVE...LIGHT LES WILL CONTINUE IN THE KEWEENAW AND INTO
ALGER/LUCE COUNTIES WITH NORTHWESTERLY CYCLONIC FLOW. ONCE
AGAIN...IT IS STILL UNCLEAR IF FLUXES WILL INCREASE ENOUGH TO
GENERATE LES OFF THE LAKE. AS SUCH...WILL CONTINUE WITH JUST CHANCE
POPS. WINDS BACK TO WNW TUE AHEAD OF A WEAK SFC TROUGH...WHICH
SHOULD ALLOW ANY LES TO SHIFT OFFSHORE EXCEPT FOR THE KEWEENAW.
THE EXTENDED PERIOD...WED-SAT...CONTINUES TO LOOK EXTREMELY COLD.
THE 12Z NWP CONTINUES TO BE IN VERY GOOD AGREEMENT IN SHOWING THE
ARCTIC FRONT MOVING THROUGH THE UPPER GREAT LAKES WED NIGHT INTO THU
MORNING...OPENING THE DOOR FOR ARCTIC AIR TO MOVE ACROSS THE REGION.
MODELS STILL SHOW 850MB TEMPS DROPPING TO -30 TO -34C BY THU EVENING
WHICH WILL CAUSE TEMPS TO STRUGGLE TO RISE ABOVE ZERO DURING THE
DAY. SFC HIGH PRESSURE IS FCST TO QUICKLY BUILD ACROSS THE AREA THU
NIGHT WHICH SHOULD ALLOW FOR EXCELLENT RADIATIVE COOLING...THUS
DROPPING SFC TEMPS TO -20F OR LOWER. IF THE SKIES CLEAR AND WINDS GO
LIGHT...THIS COULD BE ONE OF THOSE SITUATIONS SIMILAR TO EARLY MARCH
2003 WHERE NWS MQT SAW A MIN TEMP OF -31F. FOR NOW...WILL GO WITH
LOWS FRIDAY MORNING -20 TO -25 BELOW. PERHAPS SOME MODERATION IN
TEMPS BY SATURDAY WITH SLIGHT 850MB WARMING...BUT THE WINDS WILL
ALSO BE INCREASING AS THE ARCTIC HIGH STRENGTHENS LEADING TO A
TIGHTENING PRES GRADIENT ACROSS THE AREA. AS SUCH...APPARENT TEMPS
WILL NOT FEEL MUCH DIFFERENT INTO THE WEEKEND. JUST TO NOTE...THE
LATEST CFS /CLIMATE FORECAST SYSTEM/ GUIDANCE SHOWS MUCH OF MARCH
WITH BELOW NORMAL TEMPERATURES...
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM EST SAT FEB 22 2014
WITH WEAKENING LOW PRES REMAINING IN THE VCNTY OF FAR NRN
ONTARIO/JAMES BAY AND HIGH PRES CONTINUING TO RIDGE SE FROM THE SRN
CANADIAN ROCKIES TO THE MID MISSISSIPPI VALLEY...BLUSTERY WESTERLY
WINDS WILL CONTINUE FOR MUCH OF THIS FCST PERIOD AT
KIWD/KCMX/KSAW...BUT ESPECIALLY AT THE MORE EXPOSED KCMX SITE. WITH
WINDS GUSTING OVER 30KT AT KCMX OVERNIGHT THRU THE AFTN...BLSN WILL
LIKELY KEEP PREVAILING VIS IN THE LIFR CATEGORY. EXPECT SOME
FLUCTUATION WITH VIS IMPROVING TO IFR FOR BRIEF PERIODS AS WELL AS
FALLING TO VLIFR. WITH THE WESTERLY WINDS AND SOME GAPS IN THE ICE
OVER WESTERN LAKE SUPERIOR...THERE WILL BE OCNL -SHSN AT
KCMX...WHICH WILL ASSIST THE LOWER VISIBILITIES. DISTURBANCE SHOULD
INCREASE -SHSN FREQUENCY TODAY...AND THIS MAY RESULT IN VIS FALLING
MORE FREQUENTLY TO BLO 1/2SM. THERE SHOULD BE SOME IMPROVEMENT TO
IFR THIS EVENING AS WINDS VEER MORE TO THE NW AND DIMINISH SOME...
RESULTING IN LESS BLSN.
AT KIWD/KSAW...SRN EDGE OF STRATOCU/MVFR CIGS WILL BE NEAR KIWD
OVERNIGHT WHILE DOWNSLOPE WESTERLY WINDS WILL HELP TO MAINTAIN VFR
CONDITIONS AT KSAW. DEEPER MOISTURE/DISTURBANCE ROTATING INTO THE
AREA DURING THE DAY TODAY SHOULD PRODUCE A MORE SOLID MVFR CLOUD
DECK AS WELL AS SOME -SHSN/FLURRIES. AFTER THE STRONG WINDS OF
RECENT DAYS...THERE MAY BE SUFFICIENT OPEN WATER OVER WRN LAKE
SUPERIOR TO SUPPORT IFR CONDITIONS IN -SHSN AT KIWD THIS EVENING AS
WINDS VEER MORE TO THE NW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 PM EST SAT FEB 22 2014
A TIGHT PRESSURE GRADIENT BETWEEN A LOW NEAR HUDSON BAY AND A HIGH
PRESSURE RIDGE MOVING INTO THE MID MISSISSIPPI VALLEY WILL CONTINUE
TO PRODUCE WESTERLY GALE FORCE GUSTS TO 35-40KTS TONIGHT. AS THE
LOW WEAKENS ON SUNDAY...THE GRADIENT WILL WEAKEN AND LEAD TO WINDS
DROPPING TO 30KTS. NORTHWESTERLY WINDS WILL CONTINUE SUNDAY NIGHT
INTO THE FIRST HALF OF THE UPCOMING WORK WEEK...WITH GUSTS UP TO
25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 5 PM EST SUNDAY FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST /6 AM CST/ SUNDAY FOR LSZ240>246-
263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...MRD
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1129 AM CST SUN FEB 23 2014
.UPDATE...CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE
TODAY FOR MAINLY THE SE CWA. WILL LEAVE THE FLASH FLOOD WATCH IN
EFFECT FOR THE EXTREME SE CWA AS LATEST HIRES MODELS INDICATE A QUICK
INCH OF RAIN COULD BE POSSIBLE. TEMPERATURES LATE THIS AM WERE MAINLY
IN THE UPPER 50S TO AROUND 60. HIGH TEMPS THIS AFTERNOON WILL BE
PLEASANT...MAINLY IN THE LOWER 70S. THE ONLY CHANGES TO THE CURRENT
FORECAST WERE TO CUT POPS SOME FOR TODAY ACROSS THE CENTRAL AND
PORTIONS OF THE SOUTHERN CWA...AND TO ADJUST THE HOURLY TEMPS TO
ACCOUNT FOR THE LATEST TRENDS. /27/
&&
.AVIATION...MVFR CIG WL LIKELY IMPACT AREAS ALONG/S OF I-20 THIS
MORNING BEFORE VFR CIG TRY AND RETURN AFTER 15Z OR SO. ONLY
EXCEPTION MAY VERY WELL BE NEAR HBG/PIB WHERE PERSISTENT SHRA/TSRA
BRING AT LEAST INTERMITTENT MVFR/IFR CIG AND VSBY THRU MOST OF THE
DAYLIGHT HRS. THE HEAVY RAINS NEAR HBG/PIB WL COME TO AN END BY
EARLY EVENING AS THIS ACTIVITY PUSHES E. A COLD FRONT WL START
CROSSING THE ARKLAMISS FROM THE N AROUND 22Z PASSING THRU THE
PIB/HBG AREA AROUND 06-08Z TONIGHT. NLY WINDS WL BECOME A BIT GUSTY
IN WAKE OF THE FRONT...BUT LIGHTER WINDS WL RETURN DURING THE DAY
MON. /BK/15/
&&
.PREV DISCUSSION... /ISSUED 400 AM CST SUN FEB 23 2014/
SHORT TERM...TODAY THROUGH MONDAY NIGHT...LOW LEVEL WARM/MOIST
ADVECTION IS UNDERWAY ALONG THE GULF COAST THIS MORNING EVIDENT BY
INCREASING COVERAGE OF SHOWER AND THUNDERSTORM ACTIVITY ACROSS
EASTERN LA/SOUTHERN MS. FURTHER NORTH...AN ADVANCING COLD FRONT IS
ANALYZED ON THE NORTHERN FRINGES OF THE TN VALLEY WHICH IS PROGGED
TO CROSS THE ARKLAMISS STARTING LATE THIS AFTERNOON. PRIMARY CONCERN
FOR TODAY IS THE RISK FOR HEAVY RAINS ALONG THE HWY 98
CORRIDOR...AND THUNDERSTORMS THAT COULD PRODUCE SOME NICKEL TO
QUARTER SIZE HAIL ALONG AND SOUTH OF HWY 84. 00Z NMM/ARW/LOCAL WRF
OUTPUT SHOW THE AFOREMENTIONED SHOWER/THUNDER ACTIVITY EXPANDING
INTO SOUTHERN ZONES BY MID MORNING AND GRADUALLY COMING TO AN END BY
LATE AFTERNOON/EARLY EVENING.
THE GUIDANCE HAS BEEN CONSISTENT SHOWING MID LEVEL LAPSE RATES
CLIMBING INTO THE 6.5-7.5C/KM RANGE SOUTH OF I-20 AS THE LOW LEVEL
WARM AIR SURGES IN...WITH SHOWALTER INDICES IN THE -2 TO -4C RANGE
INDICATIVE OF ELEVATED CONVECTION POTENTIAL GIVEN RELATIVELY COOL
PBL PER BUFR SOUNDINGS. WHILE LOW LEVEL WINDS LOOK TO VEER WESTERLY
BY DAYBREAK...A PASSING MID/UPPER LEVEL JET STREAK JUST TO OUR NORTH
WILL PROVIDE NEEDED ASCENT FOR CONVECTION AS THE RIGHT ENTRANCE
REGION OF THIS FEATURE PASSES. A FEW DEEPER THUNDERSTORM CORES SEEM
REASONABLE GIVEN THE SYNOPTIC SETUP AND WILL KEEP THE MENTION OF
SOME QUARTER SIZE HAIL IN THE HWO FOR TODAY.
OF EQUAL (IF NOT GREATER) CONCERN IS THE POTENTIAL FOR SOME LOCALLY
HIGH RAINFALL TOTALS ALONG HWY 98 COME LATE AFTERNOON. LOCAL WRF
OUTPUT SHOWS A SWATH OF 3-5 INCHES ACROSS MARION/LAMAR/FORREST
COUNTIES BETWEEN 12Z AND 22Z...WHILE THE HI-RES NMM/ARW SHOW
SIMILARLY ALARMING TOTALS OF ANYWHERE FROM 2-4 INCHES DURING THE
SAME TIME. GIVEN PW VALUES CLIMBING NEAR/JUST ABOVE 1.5 IN ACROSS
THIS AREA BY MID DAY (RIGHT AT THE 99TH PERCENTILE FOR FEB) AND THE
CONVECTIVE NATURE OF THE ACTIVITY THESE KINDS OF TOTALS SEEM QUITE
REASONABLE. THE BIGGEST QUESTION MARK IS JUST WHERE IS THE HEAVIEST
AXIS GOING TO SET UP. THE HRRR HAS BEEN TOYING WITH THE BEST AXIS
REMAINING CLOSER TO THE COAST ON A FEW RUNS...BUT SHOWS 2-3 IN
ALONG/SOUTH OF HWY 98 ON OTHERS. GIVEN THE HEAVY RAINS WE SAW ACROSS
THIS AREA A COUPLE DAYS AGO AND THE COINCIDENT HEAVY RAIN AXIS SHOWN
IN THE HI-RES ARW/NMM/LOCAL WRF FEEL THE RISK FOR FLASH FLOODING IS
GREAT ENOUGH TO WARRANT A FLASH FLOOD WATCH THROUGH 22Z. BY EARLY
EVENING THE BETTER FORCING WILL SHIFT EAST WHICH WILL SHUNT DEEPER
CONVECTION AND ASSOCIATED HEAVY RAIN RISK EAST AS WELL.
OTHER THAN SOME LIGHT SHOWER ACTIVITY SOUTH OF I-20 THE OVERNIGHT
HOURS LOOK PRETTY QUIET AS THE COLD FRONT CROSSES THE REGION. QUIET
CONDITIONS LOOK TO PREVAIL THROUGH MONDAY NIGHT...ALTHOUGH IT`S NOT
COMPLETELY OUT OF THE QUESTION THAT A FEW LIGHT SHOWERS COULD
DEVELOP ACROSS THE DELTA EARLY TUE MORNING AS A JET STREAK IN THE
PERSISTENT WESTERLY FLOW ALOFT NOSES IN. AS FOR TEMPS/POPS...LOWERED
MAV GUIDANCE FOR THIS AFTERNOON ACROSS SOUTHEASTERN AREAS GIVEN THE
HIGH CHANCES FOR RAIN/CLOUDS THROUGH THE DAY. ALSO RAISED OVERNIGHT
LOWS FOR TUE MORNING TOWARD THE WARMER NAM/ECMWF MOS NUMBERS AND RAW
GFS OUTPUT. POPS FOR TODAY WERE RAISED QUITE A BIT NEAR HBG. /BK/
LONG TERM...TUESDAY THROUGH SUNDAY...BELOW NORMAL TEMPERATURES ARE
EXPECTED FOR THE WORK WEEK WITH NEAR NORMAL TEMPERATURES RETURNING
FOR THE WEEKEND. RAIN WILL SPREAD ACROSS THE CWA TUESDAY ASSOCIATED
WITH A SFC LOW OVER THE SOUTHERN PLAINS AND A COLD FRONT DROPPING
THROUGH THE REGION. THE ECMWF CONTINUES TO GENERATE MORE RAINFALL
THAN MODEL CONSENSUS WOULD SUGGEST OVER THE SOUTHERN PORTION OF OUR
CWA WHERE MORE THAN AN INCH TOTAL COULD FALL BY WEDNESDAY MORNING.
THE ARCTIC AIR WILL BE FILTERING INTO OUR CWA TUESDAY NIGHT AS THE
RAIN ENDS FROM THE NORTHWEST. THE LIGHT RAIN LOOKS TO MIX WITH OR
BRIEFLY CHANGE OVER TO LIGHT SNOW BEFORE ENDING EARLY WEDNESDAY
MORNING ALONG THE HIGHWAY 82 CORRIDOR. TEMPERATURES WILL REMAIN
ABOVE FREEZING AND BOTTOM OUT IN THE MID 30S ALONG THE HIGHWAY 82
CORRIDOR SO NO ACCUMULATION ON ROADWAYS IS CURRENTLY ANTICIPATED. NO
SIGNIFICANT PRECIPITATION IS EXPECTED AFTER SUNRISE WEDNESDAY. THE
STRONG CAA WILL HOLD HIGH TEMPERATURES IN THE 40S ACROSS MUCH OF THE
NORTHERN HALF OF THE AREA. THE ASSOCIATED SURFACE HIGH WILL BECOME
CENTERED OVER OUR CWA WEDNESDAY NIGHT AND THEN SHIFT EAST OF OUR CWA
THURSDAY AFTERNOON. THIS WILL SET UP THE COLDEST MORNING OF THE
FORECAST PERIOD THURSDAY MORNING WHERE LOWER 20S WILL BE COMMON IN
THE NORTH TO AROUND 30 DEGREES IN THE SOUTH. DRY WEATHER WILL
CONTINUE THURSDAY BUT A DISTURBANCE WILL DROP OVER THE SOUTHERN
PLAINS THURSDAY NIGHT AND HELP DEVELOP A SURFACE LOW. WAA AHEAD OF
THIS SYSTEM WILL BRING RAIN BACK INTO OUR WESTERN ZONES THURSDAY
NIGHT. THE ECMWF IS FASTER THAN THE GFS AND ENSEMBLES BUT CONSENSUS
BRINGS THE SHORTWAVE AND SFC LOW OVER OUR WESTERN ZONES BY FRIDAY
EVENING AND SHIFT THE SYSTEM EAST OF OUR CWA SATURDAY. DRY WEATHER
LOOKS TO RETURN SATURDAY AND LAST THROUGH MUCH OF SUNDAY. ANOTHER
DISTURBANCE WILL DROP OVER THE SOUTHERN PLAINS SUNDAY AND INCREASE
OUR RAIN CHANCES AGAIN SUNDAY NIGHT. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 73 46 60 48 / 13 13 0 5
MERIDIAN 74 47 63 46 / 20 13 0 6
VICKSBURG 73 44 58 47 / 13 11 0 5
HATTIESBURG 70 55 67 50 / 89 16 0 9
NATCHEZ 70 49 59 49 / 20 17 0 7
GREENVILLE 69 36 55 42 / 7 7 0 7
GREENWOOD 74 38 55 43 / 8 8 0 4
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...FLASH FLOOD WATCH UNTIL 4 PM CST THIS AFTERNOON FOR MSZ072>074.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION....CORRECTED
NWS JACKSON MS
400 AM CST SUN FEB 23 2014
.SHORT TERM...TODAY THROUGH MONDAY NIGHT...LOW LEVEL WARM/MOIST
ADVECTION IS UNDERWAY ALONG THE GULF COAST THIS MORNING EVIDENT BY
INCREASING COVERAGE OF SHOWER AND THUNDERSTORM ACTIVITY ACROSS
EASTERN LA/SOUTHERN MS. FURTHER NORTH...AN ADVANCING COLD FRONT IS
ANALYZED ON THE NORTHERN FRINGES OF THE TN VALLEY WHICH IS PROGGED
TO CROSS THE ARKLAMISS STARTING LATE THIS AFTERNOON. PRIMARY CONCERN
FOR TODAY IS THE RISK FOR HEAVY RAINS ALONG THE HWY 98
CORRIDOR...AND THUNDERSTORMS THAT COULD PRODUCE SOME NICKEL TO
QUARTER SIZE HAIL ALONG AND SOUTH OF HWY 84. 00Z NMM/ARW/LOCAL WRF
OUTPUT SHOW THE AFOREMENTIONED SHOWER/THUNDER ACTIVITY EXPANDING
INTO SOUTHERN ZONES BY MID MORNING AND GRADUALLY COMING TO AN END BY
LATE AFTERNOON/EARLY EVENING.
THE GUIDANCE HAS BEEN CONSISTENT SHOWING MID LEVEL LAPSE RATES
CLIMBING INTO THE 6.5-7.5C/KM RANGE SOUTH OF I-20 AS THE LOW LEVEL
WARM AIR SURGES IN...WITH SHOWALTER INDICES IN THE -2 TO -4C RANGE
INDICATIVE OF ELEVATED CONVECTION POTENTIAL GIVEN RELATIVELY COOL
PBL PER BUFR SOUNDINGS. WHILE LOW LEVEL WINDS LOOK TO VEER WESTERLY
BY DAYBREAK...A PASSING MID/UPPER LEVEL JET STREAK JUST TO OUR NORTH
WILL PROVIDE NEEDED ASCENT FOR CONVECTION AS THE RIGHT ENTRANCE
REGION OF THIS FEATURE PASSES. A FEW DEEPER THUNDERSTORM CORES SEEM
REASONABLE GIVEN THE SYNOPTIC SETUP AND WILL KEEP THE MENTION OF
SOME QUARTER SIZE HAIL IN THE HWO FOR TODAY.
OF EQUAL (IF NOT GREATER) CONCERN IS THE POTENTIAL FOR SOME LOCALLY
HIGH RAINFALL TOTALS ALONG HWY 98 COME LATE AFTERNOON. LOCAL WRF
OUTPUT SHOWS A SWATH OF 3-5 INCHES ACROSS MARION/LAMAR/FORREST
COUNTIES BETWEEN 12Z AND 22Z...WHILE THE HI-RES NMM/ARW SHOW
SIMILARLY ALARMING TOTALS OF ANYWHERE FROM 2-4 INCHES DURING THE
SAME TIME. GIVEN PW VALUES CLIMBING NEAR/JUST ABOVE 1.5 IN ACROSS
THIS AREA BY MID DAY (RIGHT AT THE 99TH PERCENTILE FOR FEB) AND THE
CONVECTIVE NATURE OF THE ACTIVITY THESE KINDS OF TOTALS SEEM QUITE
REASONABLE. THE BIGGEST QUESTION MARK IS JUST WHERE IS THE HEAVIEST
AXIS GOING TO SET UP. THE HRRR HAS BEEN TOYING WITH THE BEST AXIS
REMAINING CLOSER TO THE COAST ON A FEW RUNS...BUT SHOWS 2-3 IN
ALONG/SOUTH OF HWY 98 ON OTHERS. GIVEN THE HEAVY RAINS WE SAW ACROSS
THIS AREA A COUPLE DAYS AGO AND THE COINCIDENT HEAVY RAIN AXIS SHOWN
IN THE HI-RES ARW/NMM/LOCAL WRF FEEL THE RISK FOR FLASH FLOODING IS
GREAT ENOUGH TO WARRANT A FLASH FLOOD WATCH THROUGH 22Z. BY EARLY
EVENING THE BETTER FORCING WILL SHIFT EAST WHICH WILL SHUNT DEEPER
CONVECTION AND ASSOCIATED HEAVY RAIN RISK EAST AS WELL.
OTHER THAN SOME LIGHT SHOWER ACTIVITY SOUTH OF I-20 THE OVERNIGHT
HOURS LOOK PRETTY QUIET AS THE COLD FRONT CROSSES THE REGION. QUIET
CONDITIONS LOOK TO PREVAIL THROUGH MONDAY NIGHT...ALTHOUGH IT`S NOT
COMPLETELY OUT OF THE QUESTION THAT A FEW LIGHT SHOWERS COULD
DEVELOP ACROSS THE DELTA EARLY TUE MORNING AS A JET STREAK IN THE
PERSISTENT WESTERLY FLOW ALOFT NOSES IN. AS FOR TEMPS/POPS...LOWERED
MAV GUIDANCE FOR THIS AFTERNOON ACROSS SOUTHEASTERN AREAS GIVEN THE
HIGH CHANCES FOR RAIN/CLOUDS THROUGH THE DAY. ALSO RAISED OVERNIGHT
LOWS FOR TUE MORNING TOWARD THE WARMER NAM/ECMWF MOS NUMBERS AND RAW
GFS OUTPUT. POPS FOR TODAY WERE RAISED QUITE A BIT NEAR HBG. /BK/
.LONG TERM...TUESDAY THROUGH SUNDAY...BELOW NORMAL TEMPERATURES ARE
EXPECTED FOR THE WORK WEEK WITH NEAR NORMAL TEMPERATURES RETURNING
FOR THE WEEKEND. RAIN WILL SPREAD ACROSS THE CWA TUESDAY ASSOCIATED
WITH A SFC LOW OVER THE SOUTHERN PLAINS AND A COLD FRONT DROPPING
THROUGH THE REGION. THE ECMWF CONTINUES TO GENERATE MORE RAINFALL
THAN MODEL CONSENSUS WOULD SUGGEST OVER THE SOUTHERN PORTION OF OUR
CWA WHERE MORE THAN AN INCH TOTAL COULD FALL BY WEDNESDAY MORNING.
THE ARCTIC AIR WILL BE FILTERING INTO OUR CWA TUESDAY NIGHT AS THE
RAIN ENDS FROM THE NORTHWEST. THE LIGHT RAIN LOOKS TO MIX WITH OR
BRIEFLY CHANGE OVER TO LIGHT SNOW BEFORE ENDING EARLY WEDNESDAY
MORNING ALONG THE HIGHWAY 82 CORRIDOR. TEMPERATURES WILL REMAIN
ABOVE FREEZING AND BOTTOM OUT IN THE MID 30S ALONG THE HIGHWAY 82
CORRIDOR SO NO ACCUMULATION ON ROADWAYS IS CURRENTLY ANTICIPATED. NO
SIGNIFICANT PRECIPITATION IS EXPECTED AFTER SUNRISE WEDNESDAY. THE
STRONG CAA WILL HOLD HIGH TEMPERATURES IN THE 40S ACROSS MUCH OF THE
NORTHERN HALF OF THE AREA. THE ASSOCIATED SURFACE HIGH WILL BECOME
CENTERED OVER OUR CWA WEDNESDAY NIGHT AND THEN SHIFT EAST OF OUR CWA
THURSDAY AFTERNOON. THIS WILL SET UP THE COLDEST MORNING OF THE
FORECAST PERIOD THURSDAY MORNING WHERE LOWER 20S WILL BE COMMON IN
THE NORTH TO AROUND 30 DEGREES IN THE SOUTH. DRY WEATHER WILL
CONTINUE THURSDAY BUT A DISTURBANCE WILL DROP OVER THE SOUTHERN
PLAINS THURSDAY NIGHT AND HELP DEVELOP A SURFACE LOW. WAA AHEAD OF
THIS SYSTEM WILL BRING RAIN BACK INTO OUR WESTERN ZONES THURSDAY
NIGHT. THE ECMWF IS FASTER THAN THE GFS AND ENSEMBLES BUT CONSENSUS
BRINGS THE SHORTWAVE AND SFC LOW OVER OUR WESTERN ZONES BY FRIDAY
EVENING AND SHIFT THE SYSTEM EAST OF OUR CWA SATURDAY. DRY WEATHER
LOOKS TO RETURN SATURDAY AND LAST THROUGH MUCH OF SUNDAY. ANOTHER
DISTURBANCE WILL DROP OVER THE SOUTHERN PLAINS SUNDAY AND INCREASE
OUR RAIN CHANCES AGAIN SUNDAY NIGHT. /22/
&&
.AVIATION...MVFR CIG WL LIKELY IMPACT AREAS ALONG/S OF I-20 EARLY
THIS MORNING BEFORE VFR CIG TRY AND RETURN AFTER 15Z OR SO. ONLY
EXCEPTION MAY VERY WELL BE NEAR HBG/PIB WHERE PERSISTENT SHRA/TSRA
BRING AT LEAST INTERMITTENT MVFR/IFR CIG AND VSBY THRU MOST OF THE
DAYLIGHT HRS. THE HEAVY RAINS NEAR HBG/PIB WL COME TO AN END BY
EARLY EVENING AS THIS ACTIVITY PUSHES E. A COLD FRONT WL START
CROSSING THE ARKLAMISS FROM THE N AROUND 22Z PASSING THRU THE
PIB/HBG AREA AROUND 06-08Z TONIGHT. NLY WINDS WL BECOME A BIT GUSTY
IN WAKE OF THE FRONT...BUT LIGHTER WINDS WL RETURN DURING THE DAY
MON. /BK/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 73 46 60 48 / 31 13 0 5
MERIDIAN 74 47 63 46 / 35 13 0 6
VICKSBURG 73 44 58 47 / 26 11 0 5
HATTIESBURG 70 55 67 50 / 90 16 0 9
NATCHEZ 70 49 59 49 / 39 17 0 7
GREENVILLE 69 36 55 42 / 7 7 0 7
GREENWOOD 74 38 55 43 / 7 8 0 4
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR MSZ072>074.
LA...NONE.
AR...NONE.
&&
$$
BK/22/BK
AREA FORECAST DISCUSSION
NWS BILLINGS MT
228 PM MST SUN FEB 23 2014
.SHORT TERM...VALID FOR MON AND TUE...
ONLY MINOR CHANGES IN THE SHORT TERM FORECAST AS THE WINTER STORM
FOR THE AREA REMAINS RIGHT ON TRACK.
SO FAR THIS AFTERNOON...THE STORM IS EVOLVING AS EXPECTED. THE
OVERRUNNING PATTERN SETUP EARLY THIS MORNING AS HAS BEEN RESULTING
IN STEADY LIGHT SNOW FOR CENTRAL AND WESTERN ZONES...WHERE A
COUPLE INCHES OF SNOW HAS FALLEN ALREADY TODAY. THE MORE DYNAMIC
AND MOISTURE RICH PORTION OF THE STORM WILL MOVE INTO THE AREA
THIS EVENING AND CONTINUE OVERNIGHT TONIGHT. THE DYNAMIC WAVE THAT
WILL LEAD TO THIS ENHANCED SNOWFALL OVERNIGHT IS CURRENTLY SEEN ON
WV IMAGERY OVER SOUTHERN BRITISH COLUMBIA. THE MOISTURE RICH
PACIFIC AIR AHEAD OF THE WAVE CAN NOW BE SEEN ON WV IMAGERY
OVER IDAHO AND JUST STARTING TO PUSH INTO FAR WESTERN MONTANA.
SNOW RATES WILL INCREASE AS THIS MOISTURE AND ENHANCED SYNOPTIC
LIFT SLIDE INTO THE AREA LATE THIS AFTERNOON / EARLY THIS EVENING.
OVERNIGHT...THE WAVE WILL SLIDE SOUTH AND EAST TOWARD THE FORECAST
AREA...PRODUCING STRONG QG FORCING OVER THE AREA THROUGH MONDAY
MORNING. BY LATE MONDAY MORNING / EARLY MONDAY AFTERNOON...THE
WAVE WILL PUSH EAST INTO THE DAKOTAS AND SNOW RATES WILL BECOME
SIMILAR TO THOSE WE HAVE SEEN TODAY AS THE ONLY REMAINING FORCING
MECHANISM WILL BE THE ISENTROPIC ASSENT OVER THE COLD AIR.
SINCE THE FORECAST IS PLAYING OUT AS EXPECTED SO FAR AND MODELS
REMAIN CONSISTENT WITH QPF AMOUNTS...HAVE NOT MADE ANY SIGNIFICANT
ADJUSTMENTS TO QPF / SNOW AMOUNTS WITH THIS FORECAST UPDATE.
TEMPERATURES WILL REMAIN FAIRLY STEADY THROUGH THE AFTERNOON TODAY
AND DROP SLIGHTLY FOR THE DAY TOMORROW AS SLIGHTLY COLDER 850 MB
TEMPERATURES SLIDE INTO THE AREA BEHIND THE PASSING WAVE. THUS
HIGH TEMPERATURES IN THE SINGLE DIGITS TO AROUND TEN ARE EXPECTED
TOMORROW. LOWS OVERNIGHT TONIGHT WONT DROP SIGNIFICANTLY AS CLOUD
COVER WITH THE CONTINUOUS PRECIPITATION WILL PREVENT ANY
RADIATIONAL COOLING.
THE SECONDARY WAVE THAT MOVES INTO THE AREA MONDAY NIGHT / TUESDAY
MORNING REMAINS ON TRACK. HOWEVER...MODELS ARE HINTING AT SLIGHTLY
BETTER MOISTURE AVAILABILITY ALONG THE FOOTHILLS AND MOUNTAINS
THAN PREVIOUSLY EXPECTED. THUS HAVE FURTHER INCREASED
POPS...MAINLY SOUTH OF BILLINGS ALONG THE FOOTHILLS. HAVE ALSO
INCREASE SNOW AMOUNTS TO SHOW A FEW ADDITIONAL INCHES OF
ACCUMULATION POSSIBLE THROUGH EARLY TUESDAY MORNING. ONCE THE
SHORTWAVE RAPIDLY DEPARTS THE AREA TUESDAY AFTERNOON...THE AREA
WILL FINALLY DRY OUT AND ALL PRECIPITATION CHANCES WILL END. THE
OTHER EFFECT THE SHORTWAVE WILL HAVE IS TO BRING A REINFORCING
SHOT OF COLD AIR INTO THE AREA THROUGH THE DAY TUESDAY...WHICH
WILL KEEP OUT HIGH TEMPERATURES FROM GETTING OUT THE TEENS IN
MOST LOCATIONS. ALSO FOR LOCATIONS TOWARD MILES CITY AND
BAKER...CLOUD COVER WILL ALREADY BE DECREASING BY TUESDAY
MORNING...THUS TUESDAY MORNING COULD SEE THE COLDEST OVERNIGHT LOW
TEMPERATURES.
CHURCH
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
MAIN MESSAGE FOR THE EXTENDED FORECAST IS STILL FOCUSED ON THE
HUDSON BAY LOW AND A RIDGE OF HIGH PRESSURE ANCHORED ALONG THE
WEST COAST THROUGH THE ENTIRE WEEK. THIS PATTERN WILL ALLOW ARCTIC
AIR TO PUSH SOUTH OUT OF CANADA ALONG WITH SHORT WAVE ENERGY TO
MOVE ACROSS OUR AREA WITH NORTHERLY FLOW ALOFT. THE ONLY BREAK IN
THE COLD WEATHER WILL BE ON WEDNESDAY AS BOTH GFS AND ECMWF BRING
850 MB TEMPERATURES OF 0C TO +2C INTO THE AREA. GUIDANCE IS GOING
WITH UPPER 30S TO LOWER 40S ON WEDNESDAY BUT BELIEVE SNOW COVER
WILL BE SUFFICIENT ENOUGH TO LIMIT MUCH HEATING AND HAVE CONTINUED
HIGH TEMPERATURES IN THE LOWER 30S.
HAVE GONE MAINLY WITH THE ECMWF MODEL FOR THURSDAY AS IT PUSHES
AN ARCTIC COLD FRONT THROUGH OUR AREA DURING THE MORNING HOURS.
GFS IS ABOUT 6 HOURS BEHIND THE EC AND GIVEN THE DEPTH OF THE COLD
AIR...BELIEVE EC HAS A BETTER HANDLE ON THE TIMING OF THE FRONT.
ANOTHER SURGE OF ARCTIC AIR WILL MOVE INTO THE AREA OVER THE
WEEKEND WHICH WILL KEEP OUR TEMPERATURES WELL BELOW NORMAL FOR
THIS TIME OF THE YEAR. STRONG BAROCLINIC ZONE/FRONTOGENESIS AND
UPSLOPE FLOW DEVELOPING WITH EACH SURGE OF ARCTIC AIR AND THIS
FORCING WILL PRODUCE PERIODS OF SNOW. THE BEST AREAS OF
ACCUMULATING SNOWFALL WILL BE OVER OUR WESTERN AND CENTRAL ZONES.
AFTERNOON TEMPERATURES FRIDAY AND SATURDAY WILL ONLY BE IN THE
TEENS WEST TO SINGLE DIGITS EAST. SATURDAY NIGHT LOOKS TO BE THE
COLDEST WITH READINGS AT ALL LOCATIONS BELOW ZERO. RICHMOND
&&
.AVIATION...
IFR TO VLIFR WILL BE WIDESPREAD TONIGHT THROUGH MONDAY AS HEAVY
SNOWFALL IS EXPECTED AT ALL FLIGHT TERMINALS. HEAVY SNOW WILL
BRING MOUNTAIN OBSCURATIONS. THE SNOW WILL BEGIN TO TAPER OFF BY
MONDAY AFTERNOON. RICHMOND
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 002/009 905/014 003/032 015/022 009/013 903/007 906/011
+9/S 62/S 00/U 26/S 64/S 44/S 43/S
LVM 002/011 902/020 005/037 017/034 013/018 003/012 903/017
++/S 85/S 00/U 26/S 64/S 45/S 44/S
HDN 003/008 906/013 903/032 009/021 007/012 906/008 909/013
+9/S 62/S 00/U 16/S 64/S 44/S 43/S
MLS 901/006 906/009 902/027 004/017 002/008 909/003 910/007
+8/S 10/B 00/U 12/S 23/S 34/S 43/S
4BQ 003/008 905/010 902/032 007/022 005/011 905/007 907/011
+9/S 21/B 00/U 12/S 23/S 34/S 43/S
BHK 906/001 910/005 905/026 902/016 902/006 913/003 913/008
+9/S 10/B 00/U 01/B 12/S 33/S 43/S
SHR 006/010 906/015 001/034 014/029 010/015 000/014 903/020
++/S 75/S 00/U 13/S 43/S 34/S 43/S
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER STORM WARNING IN EFFECT UNTIL 6 AM MST TUESDAY FOR
ZONES 28>31-34>36-38>42-56>58-63>68.
WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MST TUESDAY FOR
ZONES 32-33-37.
WY...WINTER STORM WARNING IN EFFECT UNTIL 6 AM MST TUESDAY FOR
ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
Area Forecast Discussion...UPDATED
National Weather Service Missoula MT
1115 AM MST Sun Feb 23 2014
.UPDATE...Allowed the winter weather advisory for Lemhi County to expire.
&&
.DISCUSSION...Web cams across Lemhi County have shown improvement
this morning with some blue skies down by Gimore Summit. There
will continue to be some light snow there in the next 24 hours,
but light accumulations are expected.
Water vapor imagery is indicating that Pacific moisture is pushing
in over Washington and Oregon State. This is an encouraging sign
for the arrival of the precipitation by this afternoon. Also the
trend of the last several runs of the high resolution HRRR model
is showing an increase in coverage of snow across Clearwater
County and northeastern Idaho County, and west-central Montana by mid-
afternoon. This matches the moderately strong warming aloft, the
aforementioned moisture influx and strengthening of the upper
level jet to provide ample lift. This is giving us good confidence
for snowfall rates to increase, potentially to 1+ inch per hour at
times in all the areas that have a winter storm warning out.
There is also indication that there will be a 2nd push of arctic
air late this evening which would strengthen the gap winds through
places like Helmville, Highway 200, I-90, Hellgate Canyon which
would create white-out and very difficult driving conditions at
times.
&&
.AVIATION...A significant winter storm will be moving in today
causing widespread mountain obscuration, low ceilings/visibility
across north central Idaho and western Montana. The light snow
this morning is expected to slowly increase in intensity by mid
morning. For this afternoon, the snow could become quite heavy at
times especially at KMSO and KBTM with the heaviest snow expected
between 23/2000z and 24/0600z. KSMN is expected to see mainly
light snow with short periods of moderate snow during the morning
hours. The light to moderate snow will be tapering off in the
afternoon. KGPI will see light snow showers develop around
23/1500z which will combine with gusty northeast winds to cause
mainly impacts to visibility. Gusty northeast to east winds are
expected to develop across most of western Montana by this
afternoon further impacting visibility.
&&
.PREV DISCUSSION... /ISSUED 443 AM MST Sun Feb 23 2014/
..HEAVY SNOW...HAZARDOUS TRAVEL CONDITIONS TODAY THROUGH MONDAY...
DISCUSSION...
The first part of a significant winter storm has arrived over the
Northern Rockies this morning. Light snow will be present through
much of this morning, with minor accumulations throughout the
region. Be aware, this snow event will only be getting warmed up
this morning. Area roads will begin to deteriorate, with snow and
ice cover creating hazardous travel conditions. However, travel
conditions will only get worse through the day.
THE MAIN SNOW EVENT...
Beginning this afternoon, snow rates across west central Montana
and north central Idaho will quickly increase. Snowfall rates of 1
to 2 inches per hour will be common at both low and high
elevations. The epicenter of the heavy snow remains the Interstate
90 corridor through much of western Montana and Highway 93
northward and southward from Missoula. Snowfall will eventually
become unmanageable by road crews this afternoon, with possible
crippling winter travel conditions developing. Periods of heavy
snow, blowing snow (winds gusting to 40 mph in open areas and
within east-west canyons), low visibility, slick roads, disabled vehicles
in deep snow, and very cold windchill (negative 10 to negative 20
degrees) will all be present, increasing local travel misery. If
you must travel late this afternoon through midday Monday,
consider traveling with items necessary for winter survival in the
event of becoming stuck in the snow.
Snow will slowly diminish throughout Monday, leaving a cold
airmass along the Continental Divide and across northwest Montana.
Travel will likely remain challenging through Monday as well, as
road crews continue to work on clearing travel routes.
Tuesday through Thursday... Residual moisture will be lingering
around western Montana and north central Idaho and will slowly
start to dry out late Tuesday as the high pressure builds in from
the west. Clear skies, light winds and fresh snowfall will help
the temperatures plummet Tue night setting up a very cold
Wednesday morning. By Thursday, another pacific system will be
moving bringing another round of precipitation.
Long range models continue to hint at another arctic push by the
end of this week. This arctic push could potentially be stronger
than the current one so stay tuned!
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...WINTER STORM WARNING until 11 AM MST Monday Butte/Blackfoot
Region...Potomac/Seeley Lake Region.
WINTER STORM WARNING until 11 AM MST Monday Bitterroot/Sapphire
Mountains...Lower Clark Fork Region.
WINTER STORM WARNING until 11 AM MST Monday Missoula/Bitterroot
Valleys.
WINTER STORM WARNING until 11 AM MST Monday Flathead/Mission
Valleys.
WINTER WEATHER ADVISORY until 5 AM MST Monday Kootenai/Cabinet
Region...West Glacier Region.
ID...WINTER STORM WARNING until 10 AM PST Monday Northern Clearwater
Mountains...Southern Clearwater Mountains.
WINTER WEATHER ADVISORY until 10 AM PST Monday Lower Hells
Canyon/Salmon River Region...Orofino/Grangeville Region.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1153 AM CST SUN FEB 23 2014
.UPDATE...
ISSUED AT 625 AM CST SUN FEB 23 2014
JUST GOT A REPORT OF 6 INCHES SNOWFALL IN OGALLALA. ADDITIONAL
SNOWFALL THIS MORNING WOULD LIKELY PUT THAT COUNTY IN THE 6 INCHES
IN 12 HOUR CRITERIA. AN ADDITIONAL 2 INCHES WOULD PUT THEM IN THE
8 INCHES IN 24 HOUR CRITERIA. A WARNING HAS BEEN ISSUED FOR THAT
COUNTY.
UPDATE ISSUED AT 538 AM CST SUN FEB 23 2014
THE METAR AT KOGA IS SHOWING 1 MILE VSBY WITH MODERATE SNOW. THE
NEDOR CAMS IN DEUEL COUNTY SHOW SIGNIFICANT ON THE GROUND AND
STILL FALLING AS THE SECOND DISTURBANCE OPERATES ON THE CHEYENNE
DIVIDE THIS MORNING. GIVEN THE 8 PM 5 INCH SNOWFALL REPORT FROM
THE COOP OBSERVER AT BIG SPRINGS...WINTER STORM CONDITIONS ARE
LIKELY UNDERWAY IN DEUEL COUNTY. SO A WINTER STORM WARNING HAS
BEEN ISSUED FOR THAT COUNTY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CST SUN FEB 23 2014
ROAD SURFACES IN MANY AREAS CROSSED THE FREEZING MARK OVERNIGHT
AND THE SNOW MELTED AN REFROZE PRODUCING HAZARDOUS TRAVEL SO THE
WINTER WEATHER ADVISORY CONTINUES THIS MORNING.
AS ADVERTISED BY THE HIGH RESOLUTION MODELS...THE NAM...ARF...NMM
AND SREF...A COUPLED JET DEVELOPED ACROSS THE FORECAST AREA. THE
HEAVY SNOW WAS LOCALIZED ACROSS CHASE AND HAYES COUNTIES AND
PERHAPS A FEW OTHER AREAS. THE MODELS IN GENERAL SHOWED FAIR
SKILL FORECASTING THIS BUT NEAR ZERO SKILL IN LOCATION. 50 MILES
OF FORECAST ERROR WITH THE LOCATION. THE NAM BOUNCED AROUND
FAVORING CNTL LINCOLN COUNTY...THEN SRN LINCOLN COUNTY AND THEN
KEITH COUNTY. MODEL SKILL IN PREDICTING THE LOCATION OF MESOSCALE
HEAVY SNOW BANDS WAS POOR. THE WINTER STORM WARNING FOR CHASE AND
HAYES COUNTIES CONTINUES THIS MORNING. THE RADAR OUT OF KGLD
CONTINUES TO SHOW LIGHT TO MODERATE SNOW AS THIS FORMERLY HEAVY
BAND OF SNOW IS WEAKENING.
THE LATEST RADAR OUT OF KCYS IN CONJUNCTION WITH THE RAP AND NAM
MODELS SUGGESTS A SECOND BAND OF LIGHT TO MODERATE SNOW WILL MOVE
INTO WRN NEBRASKA THIS MORNING AND THEN LIFT SLOWLY NORTH AS A
DEVELOPING WARM FRONT THIS AFTERNOON AND TONIGHT. BARRING THE
DEVELOPMENT OF AN ORGANIZED HEAVY SNOW BAND...IT IS BELIEVED
SNOWFALL AMOUNTS TODAY WILL BE AN INCH OR LESS USING A 13 TO 1
RATIO WHICH HAS BEEN THE PREVAILING MARKER OUTSIDE OF THE HEAVY
SNOW BAND WHICH DEVELOPED ACROSS FAR SOUTHERN NEBRASKA LAST NIGHT.
THUS FAR...KLBF MEASURED 0.19 INCHES OF LIQUID WITH ABOUT 2
INCHES OF SNOWFALL. AN ADDITIONAL 0.08 IS FORECAST TODAY FOR A
TOTAL OF 0.27 INCHES. YESTERDAYS MODEL MEDIAN QPF WHICH WAS USED
FOR THE FORECAST WAS 0.28. THUS THE ACCURACY OF THE SNOWFALL
FORECAST HINGES ON THE SNOW TO WATER RATIO WHICH IS HIGHLY
DEPENDENT ON DEEP LIFT TO PRODUCE HIGH RATIOS.
THE COBB METHODOLOGY CONTINUES TO ADVERTISE VERY HIGH RATIOS OF
17 TO 20 TO 1 TODAY AND TONIGHT. THESE RATIOS ARE SUSPECT AND
LIKELY BIASED TOWARD THE DEVELOPMENT OF DEEP VERTICAL LIFT SO 13
TO 1 WAS USED TODAY. THE HIGH COBB RATIOS WERE USED
TONIGHT...NEAR 20 TO 1 AT KVTN...BUT HPC HAS OUTLOOKED THIS AREA
FOR SLIGHT RISK OF 4 INCHES OF ACCUMULATION. THE MEDIAN QPF AT
KVTN IS ABOUT 0.15 INCHES AND THE FORECAST IS FOR 0.15. THE 20 TO
1 RATIO THEN PRODUCES 3 INCHES OF SNOW FOR VALENTINE.
THE NAM SUGGESTS GENERALLY MODERATE LIFT AND MID LEVEL
FRONTOGENESIS TONIGHT ACROSS THE NORTH...NO WHERE NEAR THE
STRENGTH EXHIBITED BY THE COUPLED JET STRUCTURE SATURDAY NIGHT
ACROSS THE SOUTH BUT THERE IS POTENTIAL FOR A PERIOD OF MODERATE
SNOW AS THERE IS BANDING POTENTIAL. GIVEN THE UNCERTAINTIES OF
FCSTING BANDED SNOW...A MIDDLE OF THE ROAD FORECAST IS IN PLACE
FOR THE NORTH TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 353 AM CST SUN FEB 23 2014
MONDAY MORNING WILL CONTINUE TO SEE SNOW ACROSS THE NORTHERN PART
OF THE CWA AS THE NEXT WAVE CONTINUES TO PUSH ACROSS S DAKOTA AND
NORTHEAST NEB. MODELS ARE IN FAIR AGREEMENT WITH THE BAND OF SNOW
TO LINGER THROUGH MONDAY MORNING THEN DIMINISHES FOR THE
AFTERNOON. HIGHEST AMOUNTS OF ADDITIONAL SNOW LIKELY AROUND AN
INCH IN THE MORNING BEFORE BECOMING LIGHT AND PUSHING EAST.
HOWEVER YET ANOTHER DISTURBANCE IS FORECAST TO TRACK ACROSS THE
HIGH PLAINS FOR LATE MONDAY INTO TUESDAY. COLD ARCTIC HIGH
PRESSURE WILL BEGIN TO PUSH ACROSS SOUTHERN CANADA BY MONDAY
EVENING. THIS WILL BRING IN SOME DRIER AIR ACROSS THE NORTHERN
PLAINS WITH THE MAIN SNOW BANDING EXPECTED ACROSS THE SOUTHWESTERN
PART OF THE CWA. DEPTH OF THE DENDRITIC GROWTH ZONE IS FAIRLY
DEEP...HOWEVER THE BEST OMEGA IS ACROSS THE HIGHER TERRAIN TO THE
WEST. WILL HAVE TO OVER COME A SOMEWHAT DRY LOWER LEVEL WITH TOP
DOWN SATURATION...ALTHOUGH SHOULD RESULT IN AROUND AN INCH OR TWO
OF SNOW. IF A BAND OF SNOW BECOMES MORE STATIONARY...WHICH IS NOT
SUGGESTED AT THIS TIME BY THE MODELS...BUT AFTER SEE LAST NIGHTS
BAND CAN NOT BE RULED OUT...ANOTHER ADVISORY FOR 2 TO 4 INCHES
WOULD BE WARRANTED.
THE COLD HIGH PRESSURE WILL BEGIN TO BE NOTICES WITH TEMPS
FALLING TO NEAR ZERO FOR TUESDAY MORNING. TUESDAY AFTERNOON AS
THE SNOW DIMINISHES FROM THE NORTH...CLOUDS WILL BE ON THE
DECREASE. COLD ARCTIC AIR WILL SPREAD ACROSS THE AREA WITH HIGHS
STRUGGLING INTO THE 20S. BY TUESDAY NIGHT THE DISTURBANCE WILL BE
SE AND CLEARING SKIES ASSOCIATED WITH THE SFC HIGH WILL COMBINE
WITH THE SNOW PACK TO PRODUCE A VERY COLD LATE FEBRUARY NIGHT.
WIDESPREAD SINGLE DIGITS...AND MOST NOT TO FAR FROM ZERO. LOCALLY
BELOW ZERO STILL POSSIBLE...HOWEVER CENTER OF THE HIGH IS OVER
HEAD CLOSER TO MIDNIGHT SO TEMPS MIGHT BEGIN TO CLIMB OR AT LEAST
HOLD STEADY FOR THE EARLY MORNING HOURS.
SW WINDS DEVELOP FOR WED...ON THE BACK SIDE OF THE HIGH...WITH
WARMER AIR TO PUSH ACROSS THE AREA. HIGHS WARM INTO THE
30S...HOWEVER SNOW PACK COULD PLAY A ROLL IN TEMPS BELOW GUIDANCE.
REST OF THE WORK WEEK WILL CONTINUES TO SEE A RIDGE ACROSS THE
SOUTHERN ROCKIES WHICH TRAILS TO THE NW INTO THE PAC NORTHWEST.
THIS FAVORS A NORTHWEST FLOW AND PROGRESSIVE CLIPPER SYSTEM AND ON
AND OFF CLOUDS AND MAYBE SOME LIGHT SNOW. BY THE WEEKEND BOTH THE
GFS AND THE EC ARE CARVING A TROUGH ACROSS THE WESTERN CONUS WITH
MORE ZONAL FLOW EAST OF THE ROCKIES. WILL CONTINUE TO MONITOR THIS
SYSTEM WHICH MODELS EJECT ONTO THE PLAINS LATE SATURDAY INTO
SUNDAY. STILL A WEEK OUT BUT SOMETHING TO MONITOR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1147 AM CST SUN FEB 23 2014
MOSTLY MVFR CONDITIONS/CEILINGS ARE EXPECTED THROUGH THIS TAF
PERIOD. SOME DRYING OF THE ATMOSPHERE MAY ALLOW FOR VFR ACROSS
NORTH CENTRAL NEBRASKA THIS AFTERNOON. ANOTHER DISTURBANCE WILL
DROP SOUTHEAST TONIGHT WITH SNOW REDEVELOPING ACROSS WESTERN
NEBRASKA THIS EVENING...AND THEN SPREADING EAST INTO NORTH CENTRAL
AND CENTRAL NEBRASKA LATER TONIGHT INTO MONDAY. WINDS THROUGH THE
PERIOD WILL REMAIN LIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NEZ022>025-035>038-058-059.
WINTER STORM WARNING UNTIL 11 AM MST THIS MORNING FOR NEZ056-057.
&&
$$
UPDATE...CDC
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...TAYLOR
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
630 AM CST SUN FEB 23 2014
.UPDATE...
ISSUED AT 625 AM CST SUN FEB 23 2014
JUST GOT A REPORT OF 6 INCHES SNOWFALL IN OGALLALA. ADDITIONAL
SNOWFALL THIS MORNING WOULD LIKELY PUT THAT COUNTY IN THE 6 INCHES
IN 12 HOUR CRITERIA. AN ADDITIONAL 2 INCHES WOULD PUT THEM IN THE
8 INCHES IN 24 HOUR CRITERIA. A WARNING HAS BEEN ISSUED FOR THAT
COUNTY.
UPDATE ISSUED AT 538 AM CST SUN FEB 23 2014
THE METAR AT KOGA IS SHOWING 1 MILE VSBY WITH MODERATE SNOW. THE
NEDOR CAMS IN DEUEL COUNTY SHOW SIGNIFICANT ON THE GROUND AND
STILL FALLING AS THE SECOND DISTURBANCE OPERATES ON THE CHEYENNE
DIVIDE THIS MORNING. GIVEN THE 8 PM 5 INCH SNOWFALL REPORT FROM
THE COOP OBSERVER AT BIG SPRINGS...WINTER STORM CONDITIONS ARE
LIKELY UNDERWAY IN DEUEL COUNTY. SO A WINTER STORM WARNING HAS
BEEN ISSUED FOR THAT COUNTY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CST SUN FEB 23 2014
ROAD SURFACES IN MANY AREAS CROSSED THE FREEZING MARK OVERNIGHT
AND THE SNOW MELTED AN REFROZE PRODUCING HAZARDOUS TRAVEL SO THE
WINTER WEATHER ADVISORY CONTINUES THIS MORNING.
AS ADVERTISED BY THE HIGH RESOLUTION MODELS...THE NAM...ARF...NMM
AND SREF...A COUPLED JET DEVELOPED ACROSS THE FORECAST AREA. THE
HEAVY SNOW WAS LOCALIZED ACROSS CHASE AND HAYES COUNTIES AND
PERHAPS A FEW OTHER AREAS. THE MODELS IN GENERAL SHOWED FAIR
SKILL FORECASTING THIS BUT NEAR ZERO SKILL IN LOCATION. 50 MILES
OF FORECAST ERROR WITH THE LOCATION. THE NAM BOUNCED AROUND
FAVORING CNTL LINCOLN COUNTY...THEN SRN LINCOLN COUNTY AND THEN
KEITH COUNTY. MODEL SKILL IN PREDICTING THE LOCATION OF MESOSCALE
HEAVY SNOW BANDS WAS POOR. THE WINTER STORM WARNING FOR CHASE AND
HAYES COUNTIES CONTINUES THIS MORNING. THE RADAR OUT OF KGLD
CONTINUES TO SHOW LIGHT TO MODERATE SNOW AS THIS FORMERLY HEAVY
BAND OF SNOW IS WEAKENING.
THE LATEST RADAR OUT OF KCYS IN CONJUNCTION WITH THE RAP AND NAM
MODELS SUGGESTS A SECOND BAND OF LIGHT TO MODERATE SNOW WILL MOVE
INTO WRN NEBRASKA THIS MORNING AND THEN LIFT SLOWLY NORTH AS A
DEVELOPING WARM FRONT THIS AFTERNOON AND TONIGHT. BARRING THE
DEVELOPMENT OF AN ORGANIZED HEAVY SNOW BAND...IT IS BELIEVED
SNOWFALL AMOUNTS TODAY WILL BE AN INCH OR LESS USING A 13 TO 1
RATIO WHICH HAS BEEN THE PREVAILING MARKER OUTSIDE OF THE HEAVY
SNOW BAND WHICH DEVELOPED ACROSS FAR SOUTHERN NEBRASKA LAST NIGHT.
THUS FAR...KLBF MEASURED 0.19 INCHES OF LIQUID WITH ABOUT 2
INCHES OF SNOWFALL. AN ADDITIONAL 0.08 IS FORECAST TODAY FOR A
TOTAL OF 0.27 INCHES. YESTERDAYS MODEL MEDIAN QPF WHICH WAS USED
FOR THE FORECAST WAS 0.28. THUS THE ACCURACY OF THE SNOWFALL
FORECAST HINGES ON THE SNOW TO WATER RATIO WHICH IS HIGHLY
DEPENDENT ON DEEP LIFT TO PRODUCE HIGH RATIOS.
THE COBB METHODOLOGY CONTINUES TO ADVERTISE VERY HIGH RATIOS OF
17 TO 20 TO 1 TODAY AND TONIGHT. THESE RATIOS ARE SUSPECT AND
LIKELY BIASED TOWARD THE DEVELOPMENT OF DEEP VERTICAL LIFT SO 13
TO 1 WAS USED TODAY. THE HIGH COBB RATIOS WERE USED
TONIGHT...NEAR 20 TO 1 AT KVTN...BUT HPC HAS OUTLOOKED THIS AREA
FOR SLIGHT RISK OF 4 INCHES OF ACCUMULATION. THE MEDIAN QPF AT
KVTN IS ABOUT 0.15 INCHES AND THE FORECAST IS FOR 0.15. THE 20 TO
1 RATIO THEN PRODUCES 3 INCHES OF SNOW FOR VALENTINE.
THE NAM SUGGESTS GENERALLY MODERATE LIFT AND MID LEVEL
FRONTOGENESIS TONIGHT ACROSS THE NORTH...NO WHERE NEAR THE
STRENGTH EXHIBITED BY THE COUPLED JET STRUCTURE SATURDAY NIGHT
ACROSS THE SOUTH BUT THERE IS POTENTIAL FOR A PERIOD OF MODERATE
SNOW AS THERE IS BANDING POTENTIAL. GIVEN THE UNCERTAINTIES OF
FCSTING BANDED SNOW...A MIDDLE OF THE ROAD FORECAST IS IN PLACE
FOR THE NORTH TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 353 AM CST SUN FEB 23 2014
MONDAY MORNING WILL CONTINUE TO SEE SNOW ACROSS THE NORTHERN PART
OF THE CWA AS THE NEXT WAVE CONTINUES TO PUSH ACROSS S DAKOTA AND
NORTHEAST NEB. MODELS ARE IN FAIR AGREEMENT WITH THE BAND OF SNOW
TO LINGER THROUGH MONDAY MORNING THEN DIMINISHES FOR THE
AFTERNOON. HIGHEST AMOUNTS OF ADDITIONAL SNOW LIKELY AROUND AN
INCH IN THE MORNING BEFORE BECOMING LIGHT AND PUSHING EAST.
HOWEVER YET ANOTHER DISTURBANCE IS FORECAST TO TRACK ACROSS THE
HIGH PLAINS FOR LATE MONDAY INTO TUESDAY. COLD ARCTIC HIGH
PRESSURE WILL BEGIN TO PUSH ACROSS SOUTHERN CANADA BY MONDAY
EVENING. THIS WILL BRING IN SOME DRIER AIR ACROSS THE NORTHERN
PLAINS WITH THE MAIN SNOW BANDING EXPECTED ACROSS THE SOUTHWESTERN
PART OF THE CWA. DEPTH OF THE DENDRITIC GROWTH ZONE IS FAIRLY
DEEP...HOWEVER THE BEST OMEGA IS ACROSS THE HIGHER TERRAIN TO THE
WEST. WILL HAVE TO OVER COME A SOMEWHAT DRY LOWER LEVEL WITH TOP
DOWN SATURATION...ALTHOUGH SHOULD RESULT IN AROUND AN INCH OR TWO
OF SNOW. IF A BAND OF SNOW BECOMES MORE STATIONARY...WHICH IS NOT
SUGGESTED AT THIS TIME BY THE MODELS...BUT AFTER SEE LAST NIGHTS
BAND CAN NOT BE RULED OUT...ANOTHER ADVISORY FOR 2 TO 4 INCHES
WOULD BE WARRANTED.
THE COLD HIGH PRESSURE WILL BEGIN TO BE NOTICES WITH TEMPS
FALLING TO NEAR ZERO FOR TUESDAY MORNING. TUESDAY AFTERNOON AS
THE SNOW DIMINISHES FROM THE NORTH...CLOUDS WILL BE ON THE
DECREASE. COLD ARCTIC AIR WILL SPREAD ACROSS THE AREA WITH HIGHS
STRUGGLING INTO THE 20S. BY TUESDAY NIGHT THE DISTURBANCE WILL BE
SE AND CLEARING SKIES ASSOCIATED WITH THE SFC HIGH WILL COMBINE
WITH THE SNOW PACK TO PRODUCE A VERY COLD LATE FEBRUARY NIGHT.
WIDESPREAD SINGLE DIGITS...AND MOST NOT TO FAR FROM ZERO. LOCALLY
BELOW ZERO STILL POSSIBLE...HOWEVER CENTER OF THE HIGH IS OVER
HEAD CLOSER TO MIDNIGHT SO TEMPS MIGHT BEGIN TO CLIMB OR AT LEAST
HOLD STEADY FOR THE EARLY MORNING HOURS.
SW WINDS DEVELOP FOR WED...ON THE BACK SIDE OF THE HIGH...WITH
WARMER AIR TO PUSH ACROSS THE AREA. HIGHS WARM INTO THE
30S...HOWEVER SNOW PACK COULD PLAY A ROLL IN TEMPS BELOW GUIDANCE.
REST OF THE WORK WEEK WILL CONTINUES TO SEE A RIDGE ACROSS THE
SOUTHERN ROCKIES WHICH TRAILS TO THE NW INTO THE PAC NORTHWEST.
THIS FAVORS A NORTHWEST FLOW AND PROGRESSIVE CLIPPER SYSTEM AND ON
AND OFF CLOUDS AND MAYBE SOME LIGHT SNOW. BY THE WEEKEND BOTH THE
GFS AND THE EC ARE CARVING A TROUGH ACROSS THE WESTERN CONUS WITH
MORE ZONAL FLOW EAST OF THE ROCKIES. WILL CONTINUE TO MONITOR THIS
SYSTEM WHICH MODELS EJECT ONTO THE PLAINS LATE SATURDAY INTO
SUNDAY. STILL A WEEK OUT BUT SOMETHING TO MONITOR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 513 AM CST SUN FEB 23 2014
VFR IS EXPECTED ALONG AND EAST OF HIGHWAY 183 TODAY. MIXED VFR/IFR
IN SNOW AND CIGS IS EXPECTED WEST OF HWY 183.
THE ONGOING SNOW ACROSS WRN NEBRASKA IS EXPECTED TO CONTINUE THIS
MORNING AND LIFT SLOWLY NORTH INTO NRN NEB THIS AFTERNOON. TONIGHT
IT IS EXPECTED TO MOVE EAST THROUGH NRN NEB. IFR SHOULD BE FAIRLY
WIDESPREAD IN THIS AREA OF SNOW WITH CONDITIONS WORSENING
WESTWARD.
MVFR CIGS ARE EXPECTED ELSEWHERE TONIGHT BUT THIS COULD TURN OUT
TO BE VFR AT OVC035-040 AS THE MODEL CONSENSUS COULD BE
FORECASTING CIG HEIGHTS TOO LOW.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NEZ022>025-035>038-058-059-071.
WINTER STORM WARNING UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ056-
057-069-070.
&&
$$
UPDATE...CDC
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
546 AM CST SUN FEB 23 2014
.UPDATE...
ISSUED AT 538 AM CST SUN FEB 23 2014
THE METAR AT KOGA IS SHOWING 1 MILE VSBY WITH MODERATE SNOW. THE
NEDOR CAMS IN DEUEL COUNTY SHOW SIGNIFICANT ON THE GROUND AND
STILL FALLING AS THE SECOND DISTURBANCE OPERATES ON THE CHEYENNE
DIVIDE THIS MORNING. GIVEN THE 8 PM 5 INCH SNOWFALL REPORT FROM
THE COOP OBSERVER AT BIG SPRINGS...WINTER STORM CONDITIONS ARE
LIKELY UNDERWAY IN DEUEL COUNTY. SO A WINTER STORM WARNING HAS
BEEN ISSUED FOR THAT COUNTY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CST SUN FEB 23 2014
ROAD SURFACES IN MANY AREAS CROSSED THE FREEZING MARK OVERNIGHT
AND THE SNOW MELTED AN REFROZE PRODUCING HAZARDOUS TRAVEL SO THE
WINTER WEATHER ADVISORY CONTINUES THIS MORNING.
AS ADVERTISED BY THE HIGH RESOLUTION MODELS...THE NAM...ARF...NMM
AND SREF...A COUPLED JET DEVELOPED ACROSS THE FORECAST AREA. THE
HEAVY SNOW WAS LOCALIZED ACROSS CHASE AND HAYES COUNTIES AND
PERHAPS A FEW OTHER AREAS. THE MODELS IN GENERAL SHOWED FAIR
SKILL FORECASTING THIS BUT NEAR ZERO SKILL IN LOCATION. 50 MILES
OF FORECAST ERROR WITH THE LOCATION. THE NAM BOUNCED AROUND
FAVORING CNTL LINCOLN COUNTY...THEN SRN LINCOLN COUNTY AND THEN
KEITH COUNTY. MODEL SKILL IN PREDICTING THE LOCATION OF MESOSCALE
HEAVY SNOW BANDS WAS POOR. THE WINTER STORM WARNING FOR CHASE AND
HAYES COUNTIES CONTINUES THIS MORNING. THE RADAR OUT OF KGLD
CONTINUES TO SHOW LIGHT TO MODERATE SNOW AS THIS FORMERLY HEAVY
BAND OF SNOW IS WEAKENING.
THE LATEST RADAR OUT OF KCYS IN CONJUNCTION WITH THE RAP AND NAM
MODELS SUGGESTS A SECOND BAND OF LIGHT TO MODERATE SNOW WILL MOVE
INTO WRN NEBRASKA THIS MORNING AND THEN LIFT SLOWLY NORTH AS A
DEVELOPING WARM FRONT THIS AFTERNOON AND TONIGHT. BARRING THE
DEVELOPMENT OF AN ORGANIZED HEAVY SNOW BAND...IT IS BELIEVED
SNOWFALL AMOUNTS TODAY WILL BE AN INCH OR LESS USING A 13 TO 1
RATIO WHICH HAS BEEN THE PREVAILING MARKER OUTSIDE OF THE HEAVY
SNOW BAND WHICH DEVELOPED ACROSS FAR SOUTHERN NEBRASKA LAST NIGHT.
THUS FAR...KLBF MEASURED 0.19 INCHES OF LIQUID WITH ABOUT 2
INCHES OF SNOWFALL. AN ADDITIONAL 0.08 IS FORECAST TODAY FOR A
TOTAL OF 0.27 INCHES. YESTERDAYS MODEL MEDIAN QPF WHICH WAS USED
FOR THE FORECAST WAS 0.28. THUS THE ACCURACY OF THE SNOWFALL
FORECAST HINGES ON THE SNOW TO WATER RATIO WHICH IS HIGHLY
DEPENDENT ON DEEP LIFT TO PRODUCE HIGH RATIOS.
THE COBB METHODOLOGY CONTINUES TO ADVERTISE VERY HIGH RATIOS OF
17 TO 20 TO 1 TODAY AND TONIGHT. THESE RATIOS ARE SUSPECT AND
LIKELY BIASED TOWARD THE DEVELOPMENT OF DEEP VERTICAL LIFT SO 13
TO 1 WAS USED TODAY. THE HIGH COBB RATIOS WERE USED
TONIGHT...NEAR 20 TO 1 AT KVTN...BUT HPC HAS OUTLOOKED THIS AREA
FOR SLIGHT RISK OF 4 INCHES OF ACCUMULATION. THE MEDIAN QPF AT
KVTN IS ABOUT 0.15 INCHES AND THE FORECAST IS FOR 0.15. THE 20 TO
1 RATIO THEN PRODUCES 3 INCHES OF SNOW FOR VALENTINE.
THE NAM SUGGESTS GENERALLY MODERATE LIFT AND MID LEVEL
FRONTOGENESIS TONIGHT ACROSS THE NORTH...NO WHERE NEAR THE
STRENGTH EXHIBITED BY THE COUPLED JET STRUCTURE SATURDAY NIGHT
ACROSS THE SOUTH BUT THERE IS POTENTIAL FOR A PERIOD OF MODERATE
SNOW AS THERE IS BANDING POTENTIAL. GIVEN THE UNCERTAINTIES OF
FCSTING BANDED SNOW...A MIDDLE OF THE ROAD FORECAST IS IN PLACE
FOR THE NORTH TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 353 AM CST SUN FEB 23 2014
MONDAY MORNING WILL CONTINUE TO SEE SNOW ACROSS THE NORTHERN PART
OF THE CWA AS THE NEXT WAVE CONTINUES TO PUSH ACROSS S DAKOTA AND
NORTHEAST NEB. MODELS ARE IN FAIR AGREEMENT WITH THE BAND OF SNOW
TO LINGER THROUGH MONDAY MORNING THEN DIMINISHES FOR THE
AFTERNOON. HIGHEST AMOUNTS OF ADDITIONAL SNOW LIKELY AROUND AN
INCH IN THE MORNING BEFORE BECOMING LIGHT AND PUSHING EAST.
HOWEVER YET ANOTHER DISTURBANCE IS FORECAST TO TRACK ACROSS THE
HIGH PLAINS FOR LATE MONDAY INTO TUESDAY. COLD ARCTIC HIGH
PRESSURE WILL BEGIN TO PUSH ACROSS SOUTHERN CANADA BY MONDAY
EVENING. THIS WILL BRING IN SOME DRIER AIR ACROSS THE NORTHERN
PLAINS WITH THE MAIN SNOW BANDING EXPECTED ACROSS THE SOUTHWESTERN
PART OF THE CWA. DEPTH OF THE DENDRITIC GROWTH ZONE IS FAIRLY
DEEP...HOWEVER THE BEST OMEGA IS ACROSS THE HIGHER TERRAIN TO THE
WEST. WILL HAVE TO OVER COME A SOMEWHAT DRY LOWER LEVEL WITH TOP
DOWN SATURATION...ALTHOUGH SHOULD RESULT IN AROUND AN INCH OR TWO
OF SNOW. IF A BAND OF SNOW BECOMES MORE STATIONARY...WHICH IS NOT
SUGGESTED AT THIS TIME BY THE MODELS...BUT AFTER SEE LAST NIGHTS
BAND CAN NOT BE RULED OUT...ANOTHER ADVISORY FOR 2 TO 4 INCHES
WOULD BE WARRANTED.
THE COLD HIGH PRESSURE WILL BEGIN TO BE NOTICES WITH TEMPS
FALLING TO NEAR ZERO FOR TUESDAY MORNING. TUESDAY AFTERNOON AS
THE SNOW DIMINISHES FROM THE NORTH...CLOUDS WILL BE ON THE
DECREASE. COLD ARCTIC AIR WILL SPREAD ACROSS THE AREA WITH HIGHS
STRUGGLING INTO THE 20S. BY TUESDAY NIGHT THE DISTURBANCE WILL BE
SE AND CLEARING SKIES ASSOCIATED WITH THE SFC HIGH WILL COMBINE
WITH THE SNOW PACK TO PRODUCE A VERY COLD LATE FEBRUARY NIGHT.
WIDESPREAD SINGLE DIGITS...AND MOST NOT TO FAR FROM ZERO. LOCALLY
BELOW ZERO STILL POSSIBLE...HOWEVER CENTER OF THE HIGH IS OVER
HEAD CLOSER TO MIDNIGHT SO TEMPS MIGHT BEGIN TO CLIMB OR AT LEAST
HOLD STEADY FOR THE EARLY MORNING HOURS.
SW WINDS DEVELOP FOR WED...ON THE BACK SIDE OF THE HIGH...WITH
WARMER AIR TO PUSH ACROSS THE AREA. HIGHS WARM INTO THE
30S...HOWEVER SNOW PACK COULD PLAY A ROLL IN TEMPS BELOW GUIDANCE.
REST OF THE WORK WEEK WILL CONTINUES TO SEE A RIDGE ACROSS THE
SOUTHERN ROCKIES WHICH TRAILS TO THE NW INTO THE PAC NORTHWEST.
THIS FAVORS A NORTHWEST FLOW AND PROGRESSIVE CLIPPER SYSTEM AND ON
AND OFF CLOUDS AND MAYBE SOME LIGHT SNOW. BY THE WEEKEND BOTH THE
GFS AND THE EC ARE CARVING A TROUGH ACROSS THE WESTERN CONUS WITH
MORE ZONAL FLOW EAST OF THE ROCKIES. WILL CONTINUE TO MONITOR THIS
SYSTEM WHICH MODELS EJECT ONTO THE PLAINS LATE SATURDAY INTO
SUNDAY. STILL A WEEK OUT BUT SOMETHING TO MONITOR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 513 AM CST SUN FEB 23 2014
VFR IS EXPECTED ALONG AND EAST OF HIGHWAY 183 TODAY. MIXED VFR/IFR
IN SNOW AND CIGS IS EXPECTED WEST OF HWY 183.
THE ONGOING SNOW ACROSS WRN NEBRASKA IS EXPECTED TO CONTINUE THIS
MORNING AND LIFT SLOWLY NORTH INTO NRN NEB THIS AFTERNOON. TONIGHT
IT IS EXPECTED TO MOVE EAST THROUGH NRN NEB. IFR SHOULD BE FAIRLY
WIDESPREAD IN THIS AREA OF SNOW WITH CONDITIONS WORSENING
WESTWARD.
MVFR CIGS ARE EXPECTED ELSEWHERE TONIGHT BUT THIS COULD TURN OUT
TO BE VFR AT OVC035-040 AS THE MODEL CONSENSUS COULD BE
FORECASTING CIG HEIGHTS TOO LOW.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NEZ022>025-035>038-057>059-071.
WINTER STORM WARNING UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ056-
069-070.
&&
$$
UPDATE...CDC
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
514 AM CST SUN FEB 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CST SUN FEB 23 2014
ROAD SURFACES IN MANY AREAS CROSSED THE FREEZING MARK OVERNIGHT
AND THE SNOW MELTED AN REFROZE PRODUCING HAZARDOUS TRAVEL SO THE
WINTER WEATHER ADVISORY CONTINUES THIS MORNING.
AS ADVERTISED BY THE HIGH RESOLUTION MODELS...THE NAM...ARF...NMM
AND SREF...A COUPLED JET DEVELOPED ACROSS THE FORECAST AREA. THE
HEAVY SNOW WAS LOCALIZED ACROSS CHASE AND HAYES COUNTIES AND
PERHAPS A FEW OTHER AREAS. THE MODELS IN GENERAL SHOWED FAIR
SKILL FORECASTING THIS BUT NEAR ZERO SKILL IN LOCATION. 50 MILES
OF FORECAST ERROR WITH THE LOCATION. THE NAM BOUNCED AROUND
FAVORING CNTL LINCOLN COUNTY...THEN SRN LINCOLN COUNTY AND THEN
KEITH COUNTY. MODEL SKILL IN PREDICTING THE LOCATION OF MESOSCALE
HEAVY SNOW BANDS WAS POOR. THE WINTER STORM WARNING FOR CHASE AND
HAYES COUNTIES CONTINUES THIS MORNING. THE RADAR OUT OF KGLD
CONTINUES TO SHOW LIGHT TO MODERATE SNOW AS THIS FORMERLY HEAVY
BAND OF SNOW IS WEAKENING.
THE LATEST RADAR OUT OF KCYS IN CONJUNCTION WITH THE RAP AND NAM
MODELS SUGGESTS A SECOND BAND OF LIGHT TO MODERATE SNOW WILL MOVE
INTO WRN NEBRASKA THIS MORNING AND THEN LIFT SLOWLY NORTH AS A
DEVELOPING WARM FRONT THIS AFTERNOON AND TONIGHT. BARRING THE
DEVELOPMENT OF AN ORGANIZED HEAVY SNOW BAND...IT IS BELIEVED
SNOWFALL AMOUNTS TODAY WILL BE AN INCH OR LESS USING A 13 TO 1
RATIO WHICH HAS BEEN THE PREVAILING MARKER OUTSIDE OF THE HEAVY
SNOW BAND WHICH DEVELOPED ACROSS FAR SOUTHERN NEBRASKA LAST NIGHT.
THUS FAR...KLBF MEASURED 0.19 INCHES OF LIQUID WITH ABOUT 2
INCHES OF SNOWFALL. AN ADDITIONAL 0.08 IS FORECAST TODAY FOR A
TOTAL OF 0.27 INCHES. YESTERDAYS MODEL MEDIAN QPF WHICH WAS USED
FOR THE FORECAST WAS 0.28. THUS THE ACCURACY OF THE SNOWFALL
FORECAST HINGES ON THE SNOW TO WATER RATIO WHICH IS HIGHLY
DEPENDENT ON DEEP LIFT TO PRODUCE HIGH RATIOS.
THE COBB METHODOLOGY CONTINUES TO ADVERTISE VERY HIGH RATIOS OF
17 TO 20 TO 1 TODAY AND TONIGHT. THESE RATIOS ARE SUSPECT AND
LIKELY BIASED TOWARD THE DEVELOPMENT OF DEEP VERTICAL LIFT SO 13
TO 1 WAS USED TODAY. THE HIGH COBB RATIOS WERE USED
TONIGHT...NEAR 20 TO 1 AT KVTN...BUT HPC HAS OUTLOOKED THIS AREA
FOR SLIGHT RISK OF 4 INCHES OF ACCUMULATION. THE MEDIAN QPF AT
KVTN IS ABOUT 0.15 INCHES AND THE FORECAST IS FOR 0.15. THE 20 TO
1 RATIO THEN PRODUCES 3 INCHES OF SNOW FOR VALENTINE.
THE NAM SUGGESTS GENERALLY MODERATE LIFT AND MID LEVEL
FRONTOGENESIS TONIGHT ACROSS THE NORTH...NO WHERE NEAR THE
STRENGTH EXHIBITED BY THE COUPLED JET STRUCTURE SATURDAY NIGHT
ACROSS THE SOUTH BUT THERE IS POTENTIAL FOR A PERIOD OF MODERATE
SNOW AS THERE IS BANDING POTENTIAL. GIVEN THE UNCERTAINTIES OF
FCSTING BANDED SNOW...A MIDDLE OF THE ROAD FORECAST IS IN PLACE
FOR THE NORTH TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 353 AM CST SUN FEB 23 2014
MONDAY MORNING WILL CONTINUE TO SEE SNOW ACROSS THE NORTHERN PART
OF THE CWA AS THE NEXT WAVE CONTINUES TO PUSH ACROSS S DAKOTA AND
NORTHEAST NEB. MODELS ARE IN FAIR AGREEMENT WITH THE BAND OF SNOW
TO LINGER THROUGH MONDAY MORNING THEN DIMINISHES FOR THE
AFTERNOON. HIGHEST AMOUNTS OF ADDITIONAL SNOW LIKELY AROUND AN
INCH IN THE MORNING BEFORE BECOMING LIGHT AND PUSHING EAST.
HOWEVER YET ANOTHER DISTURBANCE IS FORECAST TO TRACK ACROSS THE
HIGH PLAINS FOR LATE MONDAY INTO TUESDAY. COLD ARCTIC HIGH
PRESSURE WILL BEGIN TO PUSH ACROSS SOUTHERN CANADA BY MONDAY
EVENING. THIS WILL BRING IN SOME DRIER AIR ACROSS THE NORTHERN
PLAINS WITH THE MAIN SNOW BANDING EXPECTED ACROSS THE SOUTHWESTERN
PART OF THE CWA. DEPTH OF THE DENDRITIC GROWTH ZONE IS FAIRLY
DEEP...HOWEVER THE BEST OMEGA IS ACROSS THE HIGHER TERRAIN TO THE
WEST. WILL HAVE TO OVER COME A SOMEWHAT DRY LOWER LEVEL WITH TOP
DOWN SATURATION...ALTHOUGH SHOULD RESULT IN AROUND AN INCH OR TWO
OF SNOW. IF A BAND OF SNOW BECOMES MORE STATIONARY...WHICH IS NOT
SUGGESTED AT THIS TIME BY THE MODELS...BUT AFTER SEE LAST NIGHTS
BAND CAN NOT BE RULED OUT...ANOTHER ADVISORY FOR 2 TO 4 INCHES
WOULD BE WARRANTED.
THE COLD HIGH PRESSURE WILL BEGIN TO BE NOTICES WITH TEMPS
FALLING TO NEAR ZERO FOR TUESDAY MORNING. TUESDAY AFTERNOON AS
THE SNOW DIMINISHES FROM THE NORTH...CLOUDS WILL BE ON THE
DECREASE. COLD ARCTIC AIR WILL SPREAD ACROSS THE AREA WITH HIGHS
STRUGGLING INTO THE 20S. BY TUESDAY NIGHT THE DISTURBANCE WILL BE
SE AND CLEARING SKIES ASSOCIATED WITH THE SFC HIGH WILL COMBINE
WITH THE SNOW PACK TO PRODUCE A VERY COLD LATE FEBRUARY NIGHT.
WIDESPREAD SINGLE DIGITS...AND MOST NOT TO FAR FROM ZERO. LOCALLY
BELOW ZERO STILL POSSIBLE...HOWEVER CENTER OF THE HIGH IS OVER
HEAD CLOSER TO MIDNIGHT SO TEMPS MIGHT BEGIN TO CLIMB OR AT LEAST
HOLD STEADY FOR THE EARLY MORNING HOURS.
SW WINDS DEVELOP FOR WED...ON THE BACK SIDE OF THE HIGH...WITH
WARMER AIR TO PUSH ACROSS THE AREA. HIGHS WARM INTO THE
30S...HOWEVER SNOW PACK COULD PLAY A ROLL IN TEMPS BELOW GUIDANCE.
REST OF THE WORK WEEK WILL CONTINUES TO SEE A RIDGE ACROSS THE
SOUTHERN ROCKIES WHICH TRAILS TO THE NW INTO THE PAC NORTHWEST.
THIS FAVORS A NORTHWEST FLOW AND PROGRESSIVE CLIPPER SYSTEM AND ON
AND OFF CLOUDS AND MAYBE SOME LIGHT SNOW. BY THE WEEKEND BOTH THE
GFS AND THE EC ARE CARVING A TROUGH ACROSS THE WESTERN CONUS WITH
MORE ZONAL FLOW EAST OF THE ROCKIES. WILL CONTINUE TO MONITOR THIS
SYSTEM WHICH MODELS EJECT ONTO THE PLAINS LATE SATURDAY INTO
SUNDAY. STILL A WEEK OUT BUT SOMETHING TO MONITOR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 513 AM CST SUN FEB 23 2014
VFR IS EXPECTED ALONG AND EAST OF HIGHWAY 183 TODAY. MIXED VFR/IFR
IN SNOW AND CIGS IS EXPECTED WEST OF HWY 183.
THE ONGOING SNOW ACROSS WRN NEBRASKA IS EXPECTED TO CONTINUE THIS
MORNING AND LIFT SLOWLY NORTH INTO NRN NEB THIS AFTERNOON. TONIGHT
IT IS EXPECTED TO MOVE EAST THROUGH NRN NEB. IFR SHOULD BE FAIRLY
WIDESPREAD IN THIS AREA OF SNOW WITH CONDITIONS WORSENING
WESTWARD.
MVFR CIGS ARE EXPECTED ELSEWHERE TONIGHT BUT THIS COULD TURN OUT
TO BE VFR AT OVC035-040 AS THE MODEL CONSENSUS COULD BE
FORECASTING CIG HEIGHTS TOO LOW.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NEZ022>025-035>038-056>059-071.
WINTER STORM WARNING UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ069-
070.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
356 AM CST SUN FEB 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CST SUN FEB 23 2014
ROAD SURFACES IN MANY AREAS CROSSED THE FREEZING MARK OVERNIGHT
AND THE SNOW MELTED AN REFROZE PRODUCING HAZARDOUS TRAVEL SO THE
WINTER WEATHER ADVISORY CONTINUES THIS MORNING.
AS ADVERTISED BY THE HIGH RESOLUTION MODELS...THE NAM...ARF...NMM
AND SREF...A COUPLED JET DEVELOPED ACROSS THE FORECAST AREA. THE
HEAVY SNOW WAS LOCALIZED ACROSS CHASE AND HAYES COUNTIES AND
PERHAPS A FEW OTHER AREAS. THE MODELS IN GENERAL SHOWED FAIR
SKILL FORECASTING THIS BUT NEAR ZERO SKILL IN LOCATION. 50 MILES
OF FORECAST ERROR WITH THE LOCATION. THE NAM BOUNCED AROUND
FAVORING CNTL LINCOLN COUNTY...THEN SRN LINCOLN COUNTY AND THEN
KEITH COUNTY. MODEL SKILL IN PREDICTING THE LOCATION OF MESOSCALE
HEAVY SNOW BANDS WAS POOR. THE WINTER STORM WARNING FOR CHASE AND
HAYES COUNTIES CONTINUES THIS MORNING. THE RADAR OUT OF KGLD
CONTINUES TO SHOW LIGHT TO MODERATE SNOW AS THIS FORMERLY HEAVY
BAND OF SNOW IS WEAKENING.
THE LATEST RADAR OUT OF KCYS IN CONJUNCTION WITH THE RAP AND NAM
MODELS SUGGESTS A SECOND BAND OF LIGHT TO MODERATE SNOW WILL MOVE
INTO WRN NEBRASKA THIS MORNING AND THEN LIFT SLOWLY NORTH AS A
DEVELOPING WARM FRONT THIS AFTERNOON AND TONIGHT. BARRING THE
DEVELOPMENT OF AN ORGANIZED HEAVY SNOW BAND...IT IS BELIEVED
SNOWFALL AMOUNTS TODAY WILL BE AN INCH OR LESS USING A 13 TO 1
RATIO WHICH HAS BEEN THE PREVAILING MARKER OUTSIDE OF THE HEAVY
SNOW BAND WHICH DEVELOPED ACROSS FAR SOUTHERN NEBRASKA LAST NIGHT.
THUS FAR...KLBF MEASURED 0.19 INCHES OF LIQUID WITH ABOUT 2
INCHES OF SNOWFALL. AN ADDITIONAL 0.08 IS FORECAST TODAY FOR A
TOTAL OF 0.27 INCHES. YESTERDAYS MODEL MEDIAN QPF WHICH WAS USED
FOR THE FORECAST WAS 0.28. THUS THE ACCURACY OF THE SNOWFALL
FORECAST HINGES ON THE SNOW TO WATER RATIO WHICH IS HIGHLY
DEPENDENT ON DEEP LIFT TO PRODUCE HIGH RATIOS.
THE COBB METHODOLOGY CONTINUES TO ADVERTISE VERY HIGH RATIOS OF
17 TO 20 TO 1 TODAY AND TONIGHT. THESE RATIOS ARE SUSPECT AND
LIKELY BIASED TOWARD THE DEVELOPMENT OF DEEP VERTICAL LIFT SO 13
TO 1 WAS USED TODAY. THE HIGH COBB RATIOS WERE USED
TONIGHT...NEAR 20 TO 1 AT KVTN...BUT HPC HAS OUTLOOKED THIS AREA
FOR SLIGHT RISK OF 4 INCHES OF ACCUMULATION. THE MEDIAN QPF AT
KVTN IS ABOUT 0.15 INCHES AND THE FORECAST IS FOR 0.15. THE 20 TO
1 RATIO THEN PRODUCES 3 INCHES OF SNOW FOR VALENTINE.
THE NAM SUGGESTS GENERALLY MODERATE LIFT AND MID LEVEL
FRONTOGENESIS TONIGHT ACROSS THE NORTH...NO WHERE NEAR THE
STRENGTH EXHIBITED BY THE COUPLED JET STRUCTURE SATURDAY NIGHT
ACROSS THE SOUTH BUT THERE IS POTENTIAL FOR A PERIOD OF MODERATE
SNOW AS THERE IS BANDING POTENTIAL. GIVEN THE UNCERTAINTIES OF
FCSTING BANDED SNOW...A MIDDLE OF THE ROAD FORECAST IS IN PLACE
FOR THE NORTH TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 353 AM CST SUN FEB 23 2014
MONDAY MORNING WILL CONTINUE TO SEE SNOW ACROSS THE NORTHERN PART
OF THE CWA AS THE NEXT WAVE CONTINUES TO PUSH ACROSS S DAKOTA AND
NORTHEAST NEB. MODELS ARE IN FAIR AGREEMENT WITH THE BAND OF SNOW
TO LINGER THROUGH MONDAY MORNING THEN DIMINISHES FOR THE
AFTERNOON. HIGHEST AMOUNTS OF ADDITIONAL SNOW LIKELY AROUND AN
INCH IN THE MORNING BEFORE BECOMING LIGHT AND PUSHING EAST.
HOWEVER YET ANOTHER DISTURBANCE IS FORECAST TO TRACK ACROSS THE
HIGH PLAINS FOR LATE MONDAY INTO TUESDAY. COLD ARCTIC HIGH
PRESSURE WILL BEGIN TO PUSH ACROSS SOUTHERN CANADA BY MONDAY
EVENING. THIS WILL BRING IN SOME DRIER AIR ACROSS THE NORTHERN
PLAINS WITH THE MAIN SNOW BANDING EXPECTED ACROSS THE SOUTHWESTERN
PART OF THE CWA. DEPTH OF THE DENDRITIC GROWTH ZONE IS FAIRLY
DEEP...HOWEVER THE BEST OMEGA IS ACROSS THE HIGHER TERRAIN TO THE
WEST. WILL HAVE TO OVER COME A SOMEWHAT DRY LOWER LEVEL WITH TOP
DOWN SATURATION...ALTHOUGH SHOULD RESULT IN AROUND AN INCH OR TWO
OF SNOW. IF A BAND OF SNOW BECOMES MORE STATIONARY...WHICH IS NOT
SUGGESTED AT THIS TIME BY THE MODELS...BUT AFTER SEE LAST NIGHTS
BAND CAN NOT BE RULED OUT...ANOTHER ADVISORY FOR 2 TO 4 INCHES
WOULD BE WARRANTED.
THE COLD HIGH PRESSURE WILL BEGIN TO BE NOTICES WITH TEMPS
FALLING TO NEAR ZERO FOR TUESDAY MORNING. TUESDAY AFTERNOON AS
THE SNOW DIMINISHES FROM THE NORTH...CLOUDS WILL BE ON THE
DECREASE. COLD ARCTIC AIR WILL SPREAD ACROSS THE AREA WITH HIGHS
STRUGGLING INTO THE 20S. BY TUESDAY NIGHT THE DISTURBANCE WILL BE
SE AND CLEARING SKIES ASSOCIATED WITH THE SFC HIGH WILL COMBINE
WITH THE SNOW PACK TO PRODUCE A VERY COLD LATE FEBRUARY NIGHT.
WIDESPREAD SINGLE DIGITS...AND MOST NOT TO FAR FROM ZERO. LOCALLY
BELOW ZERO STILL POSSIBLE...HOWEVER CENTER OF THE HIGH IS OVER
HEAD CLOSER TO MIDNIGHT SO TEMPS MIGHT BEGIN TO CLIMB OR AT LEAST
HOLD STEADY FOR THE EARLY MORNING HOURS.
SW WINDS DEVELOP FOR WED...ON THE BACK SIDE OF THE HIGH...WITH
WARMER AIR TO PUSH ACROSS THE AREA. HIGHS WARM INTO THE
30S...HOWEVER SNOW PACK COULD PLAY A ROLL IN TEMPS BELOW GUIDANCE.
REST OF THE WORK WEEK WILL CONTINUES TO SEE A RIDGE ACROSS THE
SOUTHERN ROCKIES WHICH TRAILS TO THE NW INTO THE PAC NORTHWEST.
THIS FAVORS A NORTHWEST FLOW AND PROGRESSIVE CLIPPER SYSTEM AND ON
AND OFF CLOUDS AND MAYBE SOME LIGHT SNOW. BY THE WEEKEND BOTH THE
GFS AND THE EC ARE CARVING A TROUGH ACROSS THE WESTERN CONUS WITH
MORE ZONAL FLOW EAST OF THE ROCKIES. WILL CONTINUE TO MONITOR THIS
SYSTEM WHICH MODELS EJECT ONTO THE PLAINS LATE SATURDAY INTO
SUNDAY. STILL A WEEK OUT BUT SOMETHING TO MONITOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1128 PM CST SAT FEB 22 2014
VISIBILITY WILL CONTINUE TO BE LESS THAN 3SM THROUGH THE NIGHT FOR
THE AREA ALONG AND SOUTHWEST OF A BBW-TIF-IEN LINE WITH LOCALIZED
VISIBILITY AT OR BELOW 1SM IN THE SOUTHWEST ALONG AND SOUTH OF AN
OGA-LBF LINE. CEILING WILL CONTINUE TO BE 1000-2000 FEET AGL IN
THE SOUTHWEST THROUGH AT LEAST SUNDAY EVENING 03Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NEZ022>025-035>038-056>059-071.
WINTER STORM WARNING UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ069-
070.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1147 PM CST SAT FEB 22 2014
.UPDATE...
ISSUED AT 939 PM CST SAT FEB 22 2014
PER COORDINATION AND WHERE CURRENT SNOW BAND IS SETTING UP...HAVE
EXPANDED WINTER WEATHER ADVISORY TO INCLUDE FURNAS AND HARLAN COUNTIES.
UPDATE ISSUED AT 859 PM CST SAT FEB 22 2014
COMPLICATED FORECAST AS WE HEAD INTO TONIGHT AS TO WHERE SNOW
BANDS WILL SET UP. HAVE BEEN MONITORING SNOW BAND ACROSS WESTERN
NEB WHICH HAS MIGRATED EASTWARD EARLY THIS EVENING. DRIER AIR TO
THE EAST HAS BEEN SLOW TO OVERCOME BUT A SNOW BAND HAS MANAGED TO
MOVE IN AND IS ORIENTED W/E GENERALLY FM KLBF TO KLXN TO KHDE AND
POINTS JUST TO THE SOUTH. THE SNOW IS ALIGNED FAIRLY WELL WITH THE MID
LEVEL FRONTOGENESIS WHICH IS PRIMARILY PROGGED ALONG OUR WESTERN
CWA THROUGH THE FIRST PART OF THE NIGHT. HAVE EXPANDED OUR CURRENT
WINTER WX ADVISORY TO INCLUDE PHELPS AND KEARNEY COUNTIES WHERE
SNOW HAS COMMENCED AND A LONGER DURATION OF SNOW IS EXPECTED. AS
WE HEAD INTO TONIGHT WE SEE AN INCREASE IN ISENTROPIC LIFT AS
INDICATED ON THE 290K SURFACE AND THE LIFT PERSISTS FOR SEVERAL
HOURS...INTO SUNDAY MORNING. THE UPPER JET STREAK NOSES ACROSS
WESTERN NEB SUNDAY MORNING WITH LIFT CONTINUING SUNDAY MORNING IN
LFQ OF JET. ONE OF THE MORE NOTABLE CHANGES IN THE LATEST MODEL
RUNS THAT SNOW IS EXPECTED TO PERSIST LONGER SUNDAY MORNING WITH
ADDITIONAL LIGHT ACCUMULATIONS POSSIBLE. SNOW AMOUNTS WILL BE
DEPENDENT UPON SNOW BANDS WITH SEVERAL INCHES...AND LOCALLY HEAVY
SNOWFALL POSSIBLE WITHIN THE BANDS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 407 PM CST SAT FEB 22 2014
...ABOVE NORMAL UNCERTAINTY TONIGHT IN A SWATH OF SNOW THAT COULD
END UP DUMPING 6-8 INCHES "IF" THE WORST CASE UNFOLDS...
ALOFT: VERY LOW AMPLITUDE WNW CYCLONIC FLOW WILL REMAIN OVER THE
CNTRL PLAINS THRU SUN. WV IMAGERY SHOWS A SUBTLE SHORTWAVE TROF
OVER BRITISH COLUMBIA. PART OF THIS TROF WILL RACE THRU TONIGHT.
SURFACE: A COLD FRONT MOVED THRU LAST NIGHT AND CURRENTLY
EXTENDED FROM ST. LOUIS-OKLAHOMA CITY-LUBBOCK TX. THIS FRONT WILL
SLOWLY SAG DEEPER INTO TX/AR BY SUNSET SUNDAY.
MEANWHILE...CANADIAN HIGH PRES WILL GRADUALLY BUILD S THRU THE
PLAINS.
REST OF THIS AFTERNOON: INCREASING CLOUDS OVER S-CNTRL NEB WILL
OBSCURE THE SUN WHILE N-CNTRL KS SHOULD SEE A NICE END TO THE DAY.
HIGH TEMPS WILL OCCUR 4-5 PM.
TONIGHT: BECOMING CLOUDY WITH A BAND OF SNOW DEVELOPING ACROSS
THE FCST AREA AND IT COULD BECOME HEAVY IN A VERY NARROW SWATH
OVER S-CNTRL NEB. PROBABILITIES OF NO SNOW AT ALL ARE HIGHEST OVER
N-CNTRL KS.
THIS WILL BE A JET STREAK DRIVEN EVENT AS WIND/MASS ADJUSTMENTS
RESULT IN WARM AIR ADVECTION AND FRONTOGENESIS /FGEN/ ON THE
FRONT THAT MOVED THRU LAST NIGHT. CROSS SECTIONS INDICATE MID-
LEVEL UPRIGHT INSTABILITY AND LIFT WILL BE STRONG IN THE DENDRITIC
GROWTH ZONE /DGZ/.
SEVERAL SCENARIOS ARE POSSIBLE TONIGHT AND WE WILL REALLY NOT KNOW
WHICH ONE IS RIGHT UNTIL WE SEE THIS UNFOLD. THIS FCST IS FRAUGHT
WITH UNCERTAINTY AND WE ARE ADMITTEDLY CONSERVATIVE ON SNOW
AMOUNTS AND THE AERIAL EXTENT OF THE ADVISORY. BE PREPARED FOR
ADJUSTMENTS LATER THIS EVENING AND TONIGHT THAT COULD RESULT IN
DRAMATICALLY INCREASING OR DECREASING AMOUNTS FOR YOUR AREA.
09Z AND 15Z SREF PROBABILITIES FOR .25" ARE HIGHEST IN THE
ADVISORY AREA. THE 15Z PROBS FOR .25" ARE HIGHER THAN 09Z AND THE
70% CHANCE OF .25" NOW EXTENDS E TO GRI. THE 19Z RAP SUPPORTS
THIS. A CHECK OF THE 18Z NAM HAS .25" TO HASTINGS.
SNOW TOTALS: GENERALLY 1-3" OVER S-CNTRL NEB. 2-3" FROM THE
TRI-CITIES WESTWARD...AND 3-4" PRIMARILY OVER DAWSON COUNTY. THIS
IS OUR BEST STAB USING A BLEND THE 00Z/06Z/12Z MULTI-MODEL QPF.
THAT PRESENTS A PROBLEM. TOO MUCH AVERAGING SHOULD HIT THE SWATH
OF SNOW CORRECTLY...BUT IT MAY BE TOO BROAD COMPARED TO REALITY
AND FCST AMOUNTS MAY NOT BE HIGH ENOUGH.
SNOW-LIQUID RATIOS: USED PRIMARILY 15:1 THRU THE EVENING AND
CLOSE TO 20:1 AFTER MIDNIGHT. GIVEN THE STRENGTH OF THE LIFT IN
THE DGZ... THESE RATIOS COULD ALSO BE CONSERVATIVE.
POSSIBLE WEAKNESSES IN TONIGHT/S FCST:
1) WE MAY BE TOO BROAD WITH THE EDGES OF THE SNOW BAND...I.E. IT
MAY BE MORE NARROW THAN DEPICTED.
2) DO WE HAVE THE HIGHEST POPS IN THE RIGHT LOCATION? THE HI-RES
GEM HAS THE BAND BETWEEN I-80 AND THE KS BORDER. WE ARE IN THE
I-80 CORRIDOR.
3) DEWPOINTS MAY BE TOO HIGH N OF I-80. DEWPOINTS IN THE SINGLE
DIGITS ARE AS CLOSE AS O`NEILL. ADVECTION OF THIS VERY DRY AIR
WILL PLAY A ROLE IN LIMITING THE NRN EXTENT OF THE BAND.
4) ARE AMOUNTS HIGH ENOUGH? WOULD NOT BE SURPRISED TO SEE A
NARROW STRIP OF WARNING LEVEL SNOW /6-8"/ SOMEWHERE GIVEN THE
RATIOS WE ARE LIKELY TO SEE.
UNCERTAINTY: PLEASE KEEP IN MIND THAT THERE ARE SOME AREAS THAT
HAVE SNOW IN THE FCST...BUT WILL SEE NO SNOW AT ALL. THIS
ESPECIALLY APPLIES IF THE FCST PROBABILITY OF SNOW AT YOUR
LOCATION IS 40% OR BELOW. THERE WILL BE A SHARP CUT-OFF ON THE NRN
AND SRN FRINGES OF THIS BAND. THE SMALL SCALE NATURE OF THIS BAND
IS PROBLEMATIC FOR PINNING DOWN DETAILS...BUT THIS COULD END UP A
WARNING LEVEL EVENT FOR SOME COUNTIES.
LOW TEMPS WERE FROM CONSENSUS OF 2M TEMPS WHICH RAISED TEMPS
SEVERAL DEGREES.
SUN: FGEN LIFTS N AND MID-LEVELS DRY OUT WITH STABILITY RETURNING.
PATCHES OF LIGHT SNOW WILL LINGER THRU MID-MORNING...BUT THE
ACCUMULATING SNOW WILL ESSENTIALLY BE OVER. PLENTY OF CLOUDS WILL
REMAIN AND A FEW FLURRIES COULD REDEVELOP N AND W OF THE TRI-
CITIES IN THE AFTERNOON.
HIGH TEMPS HAVE A LOT OF CONTINUITY WITH THE 4 AM GID FCST. THE
ONLY CHANGE WAS TO NUDGE TEMPS DOWN E OF HWY 281.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 407 PM CST SAT FEB 22 2014
THE BIG STORY WILL BE THE WELL BELOW NORMAL TEMPERATURES ALONG
WITH SEVERAL CHANCES OF WINTRY PRECIPITATION. HIGH TEMPERATURES
THROUGH THE PERIOD WILL GENERALLY AVERAGE 10 TO 15 DEGREES BELOW
NORMAL.
SUNDAY NIGHT AND MONDAY...MID LEVEL ISENTROPIC LIFT WILL RESULT
IN SOME LOW END LIGHT SNOW CHANCES PRIMARILY ACROSS OUR NORTHERN
ZONES WITH THE BETTER SNOW CHANCES WELL NORTH OF OUR FORECAST AREA
ACROSS SOUTH DAKOTA. ALTHOUGH NOT IN THE OFFICIAL FORECAST AS OF
RIGHT NOW...WILL ALSO NEED TO WATCH OUT FOR THE POSSIBILITY OF
LIGHT FREEZING DRIZZLE ACROSS OUR NORTHERN AND WESTERN ZONES LATE
SUNDAY NIGHT INTO EARLY MONDAY MORNING. ANY FREEZING DRIZZLE WOULD
PRIMARILY BE CONFINED TO OUR WESTERN AND NORTHERN ZONES. THE 12Z
GFS AND ECMWF DO NOT REALLY SHOW MUCH IN THE WAY OF FREEZING
DRIZZLE POTENTIAL...BUT THE 12Z AND 18Z NAM DO INDICATE SOME
POTENTIAL WITH LOW LEVEL SATURATION BENEATH A DRY MID LEVEL. THE
NAM IS STILL A BIT OF AN OUTLIER AND THE POTENTIAL EVEN IN THE NAM
IS SO MARGINAL THAT WE WILL CONTINUE TO LEAVE FREEZING DRIZZLE OUT
OF THE FORECAST FOR NOW. ANY SNOW AMOUNTS WOULD LIKELY BE VERY
LIGHT AND LESS THAN ONE HALF INCH.
MONDAY NIGHT THROUGH TUESDAY...A SHORTWAVE TROUGH WILL TRACK
SOUTHEAST OUT OF CANADA. ASSOCIATED UPPER JET DYNAMICS AND A
PROGRESSIVE BAND OF MID LEVEL FRONTOGENESIS WILL LEAD TO
ADDITIONAL CHANCES FOR LIGHT SNOW. NOT EXPECTING MUCH SNOW AT
THIS TIME WITH MOST PLACES SEEING FLURRIES UP TO 1 INCH. COLDER
AIR WILL FILTER IN ON TUESDAY WITH HIGHS STUCK IN THE 20S FOR MOST
AREAS.
WEDNESDAY THROUGH SATURDAY...WILL TRANSITION FROM A NORTHWESTERLY
FLOW PATTERN TO A MORE ZONAL PATTERN...WITH PERHAPS EVEN THE
DEVELOPMENT OF A TROUGH OVER THE WESTERN CONUS LATE IN THE PERIOD.
OVERALL...THIS IS MORE LIKELY BE A DRY AND COOL PERIOD FOR OUR
FORECAST AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1139 PM CST SAT FEB 22 2014
DETERIORATING CONDITIONS ARE ANTICIPATED AT KGRI OVER THE NEXT FEW
HOURS AS LIGHT SNOW OVERTAKES THE TERMINAL. WHILE WINDS WILL NOT
BE PARTICULARLY STRONG...COULD SEE VSBYS DROP DOWN TO NEAR 2SM IN
HEAVIER BANDS OF SNOW AS THEY DEVELOP AND CEILINGS LOWER TO NEAR
1500FT. OTHERWISE...SNOWFALL SHOULD BEGIN TO TAPER OFF DURING THE
LATER MORNING HOURS...WITH MVFR CEILINGS ANTICIPATED TO PERSIST
FOR MUCH OF THE DAY BEHIND THIS DEPARTING DISTURBANCE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR NEZ060-061-
072>074-082-083.
KS...NONE.
&&
$$
UPDATE...FAY
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1242 AM EST SUN FEB 23 2014
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL BRING THE CHANCE FOR SNOW SHOWERS
LATE TONIGHT...AND RAIN OR SNOW SHOWERS ON SUNDAY. COLDER AIR
WILL RETURN FOR THE BEGINNING OF THE WORK WEEK WITH LAKE EFFECT
SNOWS OVER CENTRAL NEW YORK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
8 PM UPDATE... THE CURRENT FCST IS IN FAIRLY GOOD SHAPE...SO ONLY RELATIVELY
SMALL CHGS WERE MADE ATTM.
RGNL RADAR IMAGERY SHOWS A NARROW BAND OF LGT PCPN (MAINLY -SN)
EXTENDING FROM CNTRL IL-NRN IN-NRN OH-NW PA THIS EVE. THE LATEST
RUC-13 AND HRRR OUTPUT APPEAR TO BE DOING A REASONABLY GOOD JOB
HANDLING THE EVOLUTION OF THIS PCPN SO FAR. BOTH MODELS SUGGEST IT
WILL STREAK INTO THE TWIN TIERS BY 06-09Z...THEN EXIT BY ARND 15Z
SUN MRNG...UNDERNEATH DECENT 850-700 MB FGEN FORCING. THE MAIN
FACTORS GOING AGAINST PCPN DVLPMT LOCALLY ARE DRY LOW-LVL AIR TO
OVERCOME INITIALLY...AND ALSO NON-DESCRIPT JET DYNAMICS.
OVERALL...WE FELT THE COURSE OF LEAST REGRET WAS TO BUMP POPS UP
TO LIKELY VALUES WHERE WE HAVE SOME LGT SNOW ACCUMS MENTIONED LTR
TNT INTO EARLY SUN (MOSTLY ACRS NY`S SRN TIER...WITH MAX AMTS
GENERALLY 1" OR LESS). SHSN SHOULD DIMINISH QUICKLY TO FLRYS LTR
SUN MRNG...THEN END ALTOGETHER BY MIDDAY.
OTHWS...OUR TEMP/DEW PT GRIDS WERE MASSAGED SLIGHTLY THIS EVE...TO
BEST REFLECT THE LATEST OBSERVATIONAL TRENDS.
PREV DISC... 330 PM UPDATE...
WEAK DISTURBANCE OVER THE OHIO VALLEY CREATING LIGHT PRECIPITATION
OVER IL/IN WILL MOVE OUR WAY TONIGHT. I FOUND ONE OB TO THE WEST
SHOWING 2 1/2SM IN SNOW. BASED ON THIS AND MODEL QPF...NOT
EXPECTING MUCH MORE THAN A LIGHT DUSTING OF SNOW TONIGHT
ESPECIALLY NEAR OR JUST NORTH OF THE NY/PA LINE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
330 PM UPDATE...
DISTURBANCE ABOVE MAY CONTINUE A FEW SNOW SHOWERS INTO MIDDAY
SUNDAY BEFORE ENDING AS A SPRINKLE OR FLURRY. NOT EXPECTING MUCH.
BIGGER STORY WILL BE MUCH COLDER AIR BUILDING IN SUNDAY NIGHT AND
LASTING THROUGH TUESDAY. LAKE SNOWS LOOK LIKELY WITH A FLOW
SETTLING IN BETWEEN 290 AND 270. ONE LIMITING FACTOR AT LEAST
DURING THE DAY MAY DIURNAL EFFECTS. TAKE MONDAY AFTERNOON FOR
EXAMPLE WITH NAM BUFKIT PROFILES SHOWING SURFACE BASED CAPE OF
ABOVE 40 J/KG. BASED ON LOCAL RESEARCH, THESE VALUES COUPLED WITH
LOW TO MODERATE SHEAR WOULD PROMOTE MORE OF A DIFFUSE BAND OR OPEN
CELLULAR SNOW SHOWERS DURING THE AFTERNOON THAN A WELL DEFINED
BAND. WITH THAT IN MIND TRIED TO SHOW THE BEST ACCUMS OF AT LEAST
A FEW INCHES DURING THE NIGHTTIME AND EARLY PART OF THE DAY. COULD
SEE NEEDING AN ADVISORY AT SOME POINT DOWN THE ROAD BUT A WARNING
DOES NOT SEEM LIKELY...THUS AFTER COORDINATION WITH BUFFALO NO
LAKE EFFECT WATCH AT THIS POINT. HIGHS GENERALLY IN THE 20S
THROUGH TUESDAY. I DIDN`T TOUCH TUESDAYS HIGHS OF IN THE 20S. I
DID NOTICE MODEL GUIDANCE, ALMOST ALL OF IT, IS IN THE TEENS. WILL
BE INTERESTING TO SEE WHAT HAPPENS AS 925S SUPPORT OUR HIGHS OF 20S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MEDIUM RANGE MODELS CONTINUE TO SHOW EXCELLENT AGREEMENT THROUGH
THE EXTENDED PERIOD BOTH ALOFT AND AT THE SFC. IN GENERAL THE
PERIOD WILL BE VERY COLD WITH TEMPS RUNNING 15 TO 25 DEGREES
BELOW SEASONAL NORMALS. TUESDAY NIGHT INTO WED, MODELS INDICATE SFC
LOW PRES WELL OFF THE MID ATLANTIC COAST WITH THE GFS FURTHER OUT
TO SEA THAN THE ECMWF. CURRENT MODEL TREND IS FOR AN EVEN MORE
EASTERLY TRACK SO WILL CONTINUE WITH JUST CHC POPS THROUGH THIS
PERIOD. REST OF FORECAST LOOKS PRIMARILY DRY WITH SCATTERED LAKE
EFFECT SNOW SHOWERS AND FLURRIES EAST/SOUTHEAST OF LAKE ONTARIO.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
06Z UPDATE...
VFR AT ALL SITES WITH NARROW BAND OF MID-LVL CLOUDS ACRS NY
TERMINALS. THIS NARROW BAND IS ASSOCIATED WITH LIGHT SNOW BUT IS
EXPECTED TO WEAKEN AS IT MOVES OFF TO THE EAST. THUS HAVE KEPT
MVFR TEMPO/D INTO KITH/KELM AND KBGM FROM 08Z-12Z AT TERMINALS BUT
HAVE BROUGHT VSBYS UP TO 5SM. IF TREND OF WEAKENING CONTINUES,
WILL REMOVE COMPLETELY BUT NOT CONFIDENT ENOUGH AS IT CONTINUES TO
BE ON TERMINALS` DOORSTEP.
FURTHER NORTH AT KSYR AND KRME EXPECT VFR THROUGH THE NEXT 24
HOURS, THOUGH APPEARS THAT LAKE EFFECT WILL TRY TO DEVELOP AFTER
MIDNIGHT. HOWEVER WHERE THIS SETS UP REMAINS IN QUESTION AND WILL
EVALUATE MORE FOR 12Z ISSUANCE.
ANOTHER WAVE WILL ZIP ACROSS PENNSYLVANIA LATE TONIGHT AND MAY
BRING LIGHT SNOW TO AVP, THUS HAVE INCLUDED PROB30 MENTION BETWEEN
03Z AND 06Z. NORTHWEST FLOW BEHIND WAVE WILL KICK IN ACROSS NY
TERMINALS AFTER 00Z AND THIS MAY LEAD TO MVFR CIGS DEVELOPING AT
KITH TOWARD 06Z MON.
WSW WINDS AROUND 10KTS TONIGHT WILL CONTINUE THROUGH THE DAY.
OUTLOOK...
LATE SUN NGT THROUGH TUE ATN...MVFR/IFR RESTRICTIONS IN LAKE
EFFECT -SHSN CNTRL NY TERMINALS.
TUE NGT THROUGH THU...RESTRICTIONS POSSIBLE IN SCATTERED SNOW
SHWRS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN/MLJ
SHORT TERM...HEDEN
LONG TERM...RRM
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
521 PM EST SUN FEB 23 2014
.SYNOPSIS...
FAST WESTERLY FLOW ALOFT WILL CONTAIN SEVERAL WEAK...AN GENERALLY
MOISTURE STARVED UPPER AIR DISTURBANCES WHICH WILL CROSS THE
REGION THROUGH TUESDAY. A STRONGER DISTURBANCE DIVING SOUTHEAST FROM
THE UPPER MIDWEST WILL INTERACT WITH A STALLED-OUT FRONT ACROSS THE
SOUTHEASTERN U.S. AND HELP TO SPIN-UP AN AREA OF LOW PRESSURE ALONG
THE OUTER BANKS OF NORTH CAROLINA. A LIGHT...ACCUMULATING SNOW IS
POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY. A BLAST OF ARCTIC AIR
WILL FOLLOW FOR LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SEVERAL STRIPES OF MAINLY MID AND HIGH CLOUDS WERE PRESENT ACROSS
THE FCST AREA THIS AFTERNOON...WITH NO PRECIP NOTED OVER THE PAST
SEVERAL HOURS...AND NONE EXPECTED FOR THE NEXT 1-2 HRS.
A THICKENING...AND MORE EXTENSIVE CLOUD SHIELD /ASSOCIATED WITH THE
PASSAGE OF THE LEFT EXIT REGION OF A 130 KT JET OVER A QUASI STNRY
850 MB FRONTAL BOUNDARY/ WILL QUICKLY OVERSPREAD THE CENTRAL AND
WESTERN MTNS LATE THIS AFTERNOON...REACHING THE LOWER SUSQ VALLEY
AROUND OR SHORTLY BEFORE DUSK.
SHORT TERM...HIGH RES MODELS SHOW A RANGE OF SOLUTIONS WITH RESPECT
TO THE AMOUNT AND AREAL COVERAGE OF LIGHT MIXED PRECIP /THEN SNOW/
LATE TODAY THROUGH EARLY TONIGHT ACROSS MAINLY THE SOUTHERN HALF OF
PENN.
15Z-17Z HRRR HAS BEEN THE MOST AGGRESSIVE OF ALL OPERATIONAL MODELS
/AND NEAR THE HIGH END OF THE SREF PLUMES/ BRINGING A GENERAL 1-3
TENTHS OF LEQ PRECIP TO THE SOUTHERN THIRD TO HALF OF THE STATE LATE
TODAY THROUGH ABOUT MIDNIGHT...WHILE THE LATEST HIGH-RES WRF ARW
AND OPERATIONAL NAM PAINTS VERY LITTLE OR NO QPF TO THE EAST OF THE
LAURELS.
SREF DISPLAYS A GOOD COMPROMISE AT THIS POINT...INDICATING A FEW TO
SEVERAL HUNDREDTHS OF QPF ACROSS MUCH OF CENTRAL AND SERN PA...WITH
OVER A TENTH OF AN INCH ACROSS THE LAURELS.
THE P-TYPE THROUGH 00Z WILL BE EITHER PLAIN RAIN /SE ZONES/ OR A
LIGHT RAIN AND LIGHT SNOW MIX IN THE CENTRAL MTS /WHERE 925 MB WET
BULB TEMPS WILL RIGHT AROUND 0C/...BUT MAINLY SNOW IN THE HIGHER
ELEVATIONS.
ALL OF THIS TRANSLATES INTO THE LIKELIHOOD OF AN INCH OR TWO OF SNOW
ACROSS CAMBRIA AND SOMERSET COUNTY TONIGHT /LOCALLY 3 INCHES
POSSIBLE ON THE RIDGES WETS OF RT 219/...WHILE THE CENTRAL AND
SOUTHERN VALLEYS SEE A DUSTING TO PERHAPS A LITTLE OVER ONE HALF OF
AN INCH. EXPECT LITTLE OR NO SNOW TO THE NORTH OF INTERSTATE 80 LATE
TODAY AND TONIGHT. IT/S OFTEN A TRICKY CALL TRYING TO FORECAST THESE
WEAKLY FORCED...MOISTURE STARVED MESOSCALE EVENTS.
VERY LATE TONIGHT...ANY LINGERING PRECIP WILL BE IN THE FORM OF SNOW
SHOWERS AND CONFINED TO THE LAURELS.
TEMPS FOR THE REST OF THIS AFTN WILL BE IN THE 40S TO NEAR 50F IN
THE SOUTHEAST...BUT THE THICKENING CLOUDS WILL HOLD THE MAXES UNDER
40F OVER THE WRN MTNS. THIS WILL BE THE START OF THE DOWNTURN TO OUR
TEMPS.
COLDER AIR WILL BE ADVECTING INTO THE NW. LAKE ERIE IS PRETTY MUCH
FROZEN...SO MOISTURE FLUX WILL BE LOW. HOWEVER...THE MOISTURE FROM
THE OTHER LAKES UNDER THE CYCLONIC FLOW ALOFT WILL BE ABLE TO
GENERATE PLENTY OF CLOUDS AND A FEW SHSN WITH LOCALIZED LIGHT ACCUMS
OF AN INCH OR LESS. MINS TONIGHT /RANGING FROM 10-15F ACROSS THE
MTNS...AND LOWER TO MID 20S IN THE SE/ WILL BE NEAR NORMAL IN THE
SOUTH BUT ABOUT 5F BELOW NORMAL IN THE NRN MTS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
A RELATIVELY FLAT SHORTWAVE AND ASSOCIATED 850-700 MB THERMAL TROUGH
SLIDES EAST ACROSS THE CWA MONDAY. THERE WILL BE PLENTY OF CLOUDS
ACROSS THE NORTH AND WEST. LAKE EFFECT...AND OROGRAPHIC STRATUS AND
STRATO CU CLOUD LAYER TEMPS WILL BE SMACK IN THE MIDDLE OF THE
FAVORABLE THERMAL RIBBON FOR DENDRITIC GROWTH...SO EXPECT TO SEE
OCCASIONAL FLURRIES AND SCTD MTN SNOW SHOWERS WITH AREAS OF LIGHT
ACCUMS...MAINLY ON THE RIDGES OF THE LAURELS...AND NW MTNS TO THE
WEST OF ROUTE 219.
PERHAPS THE MOST NOTICEABLE WEATHER ELEMENT MONDAY WILL BE THE GUSTY
WNW WIND. SUSTAINED SPEEDS OF 15 TO 20 MPH AND GUSTS INTO THE L30S
ARE LIKELY. MAX TEMPS WILL VARY FROM THE UPPER TEENS TO AROUND 20F
IN THE NW. THE SE WILL HAVE SOME DOWNSLOPE AND LIKELY PLENTY OF
SUNSHINE /75-90 PERCENT SUN/ BUT A -14C 8H TEMP WILL MEAN THAT IT
WILL STRUGGLE TO GET INTO THE M30S.
WIND CHILLS WILL RANGE FROM ZERO TO 5 ABOVE AT TIMES ACROSS THE NW
MTNS AND LAURELS...TO AROUND 20F IN THE LOWER SUSQ VALLEY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
THE WORK WEEK WILL SEE THE RETURN OF COLDER AIR AND STRONG
NORTHWESTERLY FLOW. TEMPERATURES WILL GET SUCCESSIVELY COLDER AS
THE WEEK PROGRESSES. A RIDGE WILL RE- ESTABLISH ITSELF OVER THE
FAR WESTERN UNITED STATES...WHICH SHOULD ALLOW COLDER AIR TO PUSH
SOUTHWARD INTO THE GREAT LAKES AND NORTHEASTERN UNITED STATES.
A WEAK CLIPPER SHOULD GLANCE THE NORTHERN HALF OF PA MONDAY NIGHT
INTO TUESDAY. THIS SHOULD BRING SOME LIGHT SNOW TO THE NW
MTNS...AND FURTHER DECREASE TEMPERATURES.
A WEAK SHORT WAVE WILL FOLLOW IN ITS WAKE...WHICH SHOULD BRING
ANOTHER CHANCE FOR SNOW TO THE CENTRAL AND NW MTNS.
THE NEXT CHANCE FOR MORE WIDESPREAD SNOW WILL BE WEDNESDAY...AS A
DEEPENING TROUGH WILL SWING THROUGH THE MIDWEST. MOST OF THE
MOISTURE WILL REMAIN OFF THE COAST. HOWEVER...GIVEN THE COLD AIR
MASS...COUPLED WITH THE MOIST SOUTHWESTERLY FLOW COULD ALLOW FOR ANOTHER
ROUND OF SNOW ACROSS PENNSYLVANIA WEDNESDAY. THERE IS STILL SOME
VARIANCES ON SNOW AMOUNT AND POSITION SO HAVE LEFT BROAD POPS
WEDNESDAY. THIS SYSTEM SHOULD QUICKLY EXIT THE REGION WEDNESDAY
EVENING. HAVE KEPT POPS MAINLY IN THE 30-40 PERCENT RANGE THROUGH
MUCH OF THIS PERIOD...THOUGH HAVE INCREASED IT THROUGHOUT THE
LAURELS AND THE NW MTNS...DUE TO THE UPSLOPE FLOW ENHANCEMENT.
THE LONG RANGE MODELS ARE SHOWING A BRIEF WARMUP AT THE END OF THE
WORK WEEK. HOWEVER TEMPERATURES SHOULD REMAIN BELOW
FREEZING...AND WILL DROP BACK DOWN NEXT WEEKEND.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
BAND OF LGT RAIN/SNOW SHOWERS WILL STREAK ACRS THE SRN AIRFIELDS
THRU 03-06Z...ACCOMPANIED MVFR TO LOW END VFR CONDS TO THE E OF
THE MTNS. ELEVATION FACTOR AT JST RESULTING IN LOWER CONDS WITH IFR
TO EVEN LIFR FOR A BRIEF TIME THIS EVE. KEPT MDT/LNS JUST ABOVE
MVFR ALTHOUGH A PERIOD OF MVFR IS PSBL AFT 00Z. HIRES ENSEMBLE
MEAN SHIFTS ALL PCPN E OF THE AIRSPACE BY 09Z. TO THE NORTH...
EXPECT VFR BKN CIGS 050-100 TO PREVAIL INTO TNGT. A MORE TYPICAL
POST-FRONTAL NW FLOW PATTERN WILL DEVELOP INTO MONDAY WITH GUSTY
WNW WINDS AND -SHSN INVOF BFD BY MORNING.
SEVERAL WEAK DISTURBANCES ALOFT WILL ROTATE THROUGH THE REGION
INTO EARLY NEXT WEEK...AS A BROAD AND INCREASINGLY COLD CYCLONIC
FLOW PATTERN GRIPS MUCH OF THE NERN U.S. COASTAL LOW PRES WILL
DEVELOP NEAR OBX AND LIFT NEWD ON WED. A MAINLY DRY COLD FROPA
WILL REINFORCE THE COLD AIRMASS ON THURS. A GULF COAST SYSTEM MAY
AFFECT THE AREA BY NEXT FRI/SAT.
OUTLOOK...
MON...MVFR/SHSN NW. VFR ELSEWHERE.
TUE-WED...MVFR-IFR PSBL WITH -SN.
THURS...MVFR/SNSH NW. VFR ELSEWHERE.
FRI...RESTRICTIONS PSBL INTO FRI NGT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...CERU/EVANEGO
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
357 PM EST SUN FEB 23 2014
.SYNOPSIS...
FAST WESTERLY FLOW ALOFT WILL CONTAIN SEVERAL WEAK...AN GENERALLY
MOISTURE STARVED UPPER AIR DISTURBANCES WHICH WILL CROSS THE
REGION THROUGH TUESDAY. A STRONGER DISTURBANCE DIVING SOUTHEAST FROM
THE UPPER MIDWEST WILL INTERACT WITH A STALLED-OUT FRONT ACROSS THE
SOUTHEASTERN U.S. AND HELP TO SPIN-UP AN AREA OF LOW PRESSURE ALONG
THE OUTER BANKS OF NORTH CAROLINA. A LIGHT...ACCUMULATING SNOW IS
POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY. A BLAST OF ARCTIC AIR
WILL FOLLOW FOR LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SEVERAL STRIPES OF MAINLY MID AND HIGH CLOUDS WERE PRESENT ACROSS
THE FCST AREA THIS AFTERNOON...WITH NO PRECIP NOTED OVER THE PAST
SEVERAL HOURS...AND NONE EXPECTED FOR THE NEXT 1-2 HRS.
A THICKENING...AND MORE EXTENSIVE CLOUD SHIELD /ASSOCIATED WITH THE
PASSAGE OF THE LEFT EXIT REGION OF A 130 KT JET OVER A QUASI STNRY
850 MB FRONTAL BOUNDARY/ WILL QUICKLY OVERSPREAD THE CENTRAL AND
WESTERN MTNS LATE THIS AFTERNOON...REACHING THE LOWER SUSQ VALLEY
AROUND OR SHORTLY BEFORE DUSK.
SHORT TERM...HIGH RES MODELS SHOW A RANGE OF SOLUTIONS WITH RESPECT
TO THE AMOUNT AND AREAL COVERAGE OF LIGHT MIXED PRECIP /THEN SNOW/
LATE TODAY THROUGH EARLY TONIGHT ACROSS MAINLY THE SOUTHERN HALF OF
PENN.
15Z-17Z HRRR HAS BEEN THE MOST AGGRESSIVE OF ALL OPERATIONAL MODELS
/AND NEAR THE HIGH END OF THE SREF PLUMES/ BRINGING A GENERAL 1-3
TENTHS OF LEQ PRECIP TO THE SOUTHERN THIRD TO HALF OF THE STATE LATE
TODAY THROUGH ABOUT MIDNIGHT...WHILE THE LATEST HIGH-RES WRF ARW
AND OPERATIONAL NAM PAINTS VERY LITTLE OR NO QPF TO THE EAST OF THE
LAURELS.
SREF DISPLAYS A GOOD COMPROMISE AT THIS POINT...INDICATING A FEW TO
SEVERAL HUNDREDTHS OF QPF ACROSS MUCH OF CENTRAL AND SERN PA...WITH
OVER A TENTH OF AN INCH ACROSS THE LAURELS.
THE P-TYPE THROUGH 00Z WILL BE EITHER PLAIN RAIN /SE ZONES/ OR A
LIGHT RAIN AND LIGHT SNOW MIX IN THE CENTRAL MTS /WHERE 925 MB WET
BULB TEMPS WILL RIGHT AROUND 0C/...BUT MAINLY SNOW IN THE HIGHER
ELEVATIONS.
ALL OF THIS TRANSLATES INTO THE LIKELIHOOD OF AN INCH OR TWO OF SNOW
ACROSS CAMBRIA AND SOMERSET COUNTY TONIGHT /LOCALLY 3 INCHES
POSSIBLE ON THE RIDGES WETS OF RT 219/...WHILE THE CENTRAL AND
SOUTHERN VALLEYS SEE A DUSTING TO PERHAPS A LITTLE OVER ONE HALF OF
AN INCH. EXPECT LITTLE OR NO SNOW TO THE NORTH OF INTERSTATE 80 LATE
TODAY AND TONIGHT. IT/S OFTEN A TRICKY CALL TRYING TO FORECAST THESE
WEAKLY FORCED...MOISTURE STARVED MESOSCALE EVENTS.
VERY LATE TONIGHT...ANY LINGERING PRECIP WILL BE IN THE FORM OF SNOW
SHOWERS AND CONFINED TO THE LAURELS.
TEMPS FOR THE REST OF THIS AFTN WILL BE IN THE 40S TO NEAR 50F IN
THE SOUTHEAST...BUT THE THICKENING CLOUDS WILL HOLD THE MAXES UNDER
40F OVER THE WRN MTNS. THIS WILL BE THE START OF THE DOWNTURN TO OUR
TEMPS.
COLDER AIR WILL BE ADVECTING INTO THE NW. LAKE ERIE IS PRETTY MUCH
FROZEN...SO MOISTURE FLUX WILL BE LOW. HOWEVER...THE MOISTURE FROM
THE OTHER LAKES UNDER THE CYCLONIC FLOW ALOFT WILL BE ABLE TO
GENERATE PLENTY OF CLOUDS AND A FEW SHSN WITH LOCALIZED LIGHT ACCUMS
OF AN INCH OR LESS. MINS TONIGHT /RANGING FROM 10-15F ACROSS THE
MTNS...AND LOWER TO MID 20S IN THE SE/ WILL BE NEAR NORMAL IN THE
SOUTH BUT ABOUT 5F BELOW NORMAL IN THE NRN MTS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
A RELATIVELY FLAT SHORTWAVE AND ASSOCIATED 850-700 MB THERMAL TROUGH
SLIDES EAST ACROSS THE CWA MONDAY. THERE WILL BE PLENTY OF CLOUDS
ACROSS THE NORTH AND WEST. LAKE EFFECT...AND OROGRAPHIC STRATUS AND
STRATO CU CLOUD LAYER TEMPS WILL BE SMACK IN THE MIDDLE OF THE
FAVORABLE THERMAL RIBBON FOR DENDRITIC GROWTH...SO EXPECT TO SEE
OCCASIONAL FLURRIES AND SCTD MTN SNOW SHOWERS WITH AREAS OF LIGHT
ACCUMS...MAINLY ON THE RIDGES OF THE LAURELS...AND NW MTNS TO THE
WEST OF ROUTE 219.
PERHAPS THE MOST NOTICEABLE WEATHER ELEMENT MONDAY WILL BE THE GUSTY
WNW WIND. SUSTAINED SPEEDS OF 15 TO 20 MPH AND GUSTS INTO THE L30S
ARE LIKELY. MAX TEMPS WILL VARY FROM THE UPPER TEENS TO AROUND 20F
IN THE NW. THE SE WILL HAVE SOME DOWNSLOPE AND LIKELY PLENTY OF
SUNSHINE /75-90 PERCENT SUN/ BUT A -14C 8H TEMP WILL MEAN THAT IT
WILL STRUGGLE TO GET INTO THE M30S.
WIND CHILLS WILL RANGE FROM ZERO TO 5 ABOVE AT TIMES ACROSS THE NW
MTNS AND LAURELS...TO AROUND 20F IN THE LOWER SUSQ VALLEY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
THE WORK WEEK WILL SEE THE RETURN OF COLDER AIR AND STRONG
NORTHWESTERLY FLOW. TEMPERATURES WILL GET SUCCESSIVELY COLDER AS
THE WEEK PROGRESSES. A RIDGE WILL RE- ESTABLISHE ITSELF OVER THE
FAR WESTERN UNITED STATES...WHICH SHOULD ALLOW COLDER AIR TO PUSH
SOUTHWARD INTO THE GREAT LAKES AND NORTHEASTERN UNITED STATES.
A WEAK CLIPPER SHOULD GLANCE THE NORTHERN HALF OF PA MONDAY NIGHT
INTO TUESDAY. THIS SHOULD BRING SOME LIGHT SNOW TO THE NW
MTNS...AND FURTHER DECREASE TEMPERATURES.
A WEAK SHORT WAVE WILL FOLLOW IN ITS WAKE...WHICH SHOULD BRING
ANOTHER CHANCE FOR SNOW TO THE CENTRAL AND NW MTNS.
THE NEXT CHANCE FOR MORE WIDESPREAD SNOW WILL BE WEDNESDAY...AS A
DEEPENING TROUGH WILL SWING THROUGH THE MIDWEST. MOST OF THE
MOISTURE WILL REMAIN OFF THE COAST. HOWEVER...GIVEN THE COLD AIR
MASS...COUPLED WITH THE MOIST SOUTHWESTERLY FLOW COULD ALLOW FOR ANOTHER
ROUND OF SNOW ACROSS PENNSYLVANIA WEDNESDAY. THERE IS STILL SOME
VARIANCES ON SNOW AMOUNT AND POSITION SO HAVE LEFT BROAD POPS
WEDNESDAY. THIS SYSTEM SHOULD QUICKLY EXIT THE REGION WEDNESDAY
EVENING. HAVE KEPT POPS MAINLY IN THE 30-40 PERCENT RANGE THROUGH
MUCH OF THIS PERIOD...THOUGH HAVE INCREASED IT THROUGHOUT THE
LAURELS AND THE NW MTNS...DUE TO THE UPSLOPE FLOW ENHANCEMENT.
THE LONG RANGE MODELS ARE SHOWING A BRIEF WARMUP AT THE END OF THE
WORK WEEK. HOWEVER TEMPERATURES SHOULD REMAIN BELOW
FREEZING...AND WILL DROP BACK DOWN NEXT WEEKEND.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
SFC COLD FRONT HAS PUSHED TO THE SOUTH OF THE PENN/MD BORDER AT
MIDDAY. INCREASING DEEP LAYER LIFT WILL CAUSE CLOUDS TO OVERSPREAD
THE LAUREL HIGHLANDS AND NW MTNS LATE THIS AFTERNOON...AND THE REST
OF THE REGION TONIGHT.
INCREASING...DOWNSLOPE WESTERLY FLOW OF AROUND 10 KTS WILL COMBINE
WITH THE MODERATE TEMPS ALOFT TO PRODUCE BREAKS IN THE LAYERED MID
AND HIGH CLOUDS BUT NOTHING MORE THAN A SPRINKLE OR PASSING FLURRY
THIS AFTERNOON.
PERIODS OF MVFR...AND EVEN SOME BRIEF IFR...WILL DEVELOP IN SNOW
SHOWERS /MAINLY ACROSS THE LAUREL HIGHLANDS LATE TODAY...AND
TONIGHT/. SOMEWHAT LOWER PROBABILITY EXISTS FOR THESE FLIGHT
REDUCTIONS SPREADING INTO THE KMDT AND KLNS AREAS TONIGHT. KEPT
VSBYS JUST A TAD ABOVE MVFR AT KMDT...KLNS AND KTHV AS SOME AREAS
OF LIGHT RAIN/SNOW SPREAD ACROSS THE REGION THIS EVENING UNTIL
AROUND 05Z.
ELSEWHERE...ACROSS MUCH OF CENTRAL AND NRN PENN...GENERALLY VFR BKN
CIGS WILL PREVAIL WITH JUST SOME SPOTTY LIGHT RAIN/SNOW
SHOWERS...CHANGING TO SNOW SHOWERS TONIGHT.
OUTLOOK...
MON...MVFR/SHSN NW. VFR ELSEWHERE.
TUE...MVFR-IFR PSBL IN -SHSN. VFR ELSEWHERE.
WED...PSBL REDUCTIONS DUE TO LOW PRES DEVELOPING OVR NC MOVG
NEWD.
THUR...MVFR/SNSH NW. VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...CERU/EVANEGO
AVIATION...LAMBERT/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
231 PM EST SUN FEB 23 2014
.SYNOPSIS...
FAST WESTERLY FLOW ALOFT WILL CONTAIN SEVERAL WEAK...AN GENERALLY
MOISTURE STARVED UPPER AIR DISTURBANCES WHICH WILL CROSS THE
REGION THROUGH TUESDAY. A STRONGER DISTURBANCE DIVING SOUTHEAST FROM
THE UPPER MIDWEST WILL INTERACT WITH A STALLED-OUT FRONT ACROSS THE
SOUTHEASTERN U.S. AND HELP TO SPIN-UP AN AREA OF LOW PRESSURE ALONG
THE OUTER BANKS OF NORTH CAROLINA. A LIGHT...ACCUMULATING SNOW IS
POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY. A BLAST OF ARCTIC AIR
WILL FOLLOW FOR LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SEVERAL STRIPES OF MAINLY MID AND HIGH CLOUDS WERE PRESENT ACROSS
THE FCST AREA THIS AFTERNOON...WITH NO PRECIP NOTED OVER THE PAST
SEVERAL HOURS...AND NONE EXPECTED FOR THE NEXT 1-2 HRS.
A THICKENING...AND MORE EXTENSIVE CLOUD SHIELD /ASSOCIATED WITH THE
PASSAGE OF THE LEFT EXIT REGION OF A 130 KT JET OVER A QUASI STNRY
850 MB FRONTAL BOUNDARY/ WILL QUICKLY OVERSPREAD THE CENTRAL AND
WESTERN MTNS LATE THIS AFTERNOON...REACHING THE LOWER SUSQ VALLEY
AROUND OR SHORTLY BEFORE DUSK.
SHORT TERM...HIGH RES MODELS SHOW A RANGE OF SOLUTIONS WITH RESPECT
TO THE AMOUNT AND AREAL COVERAGE OF LIGHT MIXED PRECIP /THEN SNOW/
LATE TODAY THROUGH EARLY TONIGHT ACROSS MAINLY THE SOUTHERN HALF OF
PENN.
15Z-17Z HRRR HAS BEEN THE MOST AGGRESSIVE OF ALL OPERATIONAL MODELS
/AND NEAR THE HIGH END OF THE SREF PLUMES/ BRINGING A GENERAL 1-3
TENTHS OF LEQ PRECIP TO THE SOUTHERN THIRD TO HALF OF THE STATE LATE
TODAY THROUGH ABOUT MIDNIGHT...WHILE THE LATEST HIGH-RES WRF ARW
AND OPERATIONAL NAM PAINTS VERY LITTLE OR NO QPF TO THE EAST OF THE
LAURELS.
SREF DISPLAYS A GOOD COMPROMISE AT THIS POINT...INDICATING A FEW TO
SEVERAL HUNDREDTHS OF QPF ACROSS MUCH OF CENTRAL AND SERN PA...WITH
OVER A TENTH OF AN INCH ACROSS THE LAURELS.
THE P-TYPE THROUGH 00Z WILL BE EITHER PLAIN RAIN /SE ZONES/ OR A
LIGHT RAIN AND LIGHT SNOW MIX IN THE CENTRAL MTS /WHERE 925 MB WET
BULB TEMPS WILL RIGHT AROUND 0C/...BUT MAINLY SNOW IN THE HIGHER
ELEVATIONS.
ALL OF THIS TRANSLATES INTO THE LIKELIHOOD OF AN INCH OR TWO OF SNOW
ACROSS CAMBRIA AND SOMERSET COUNTY TONIGHT /LOCALLY 3 INCHES
POSSIBLE ON THE RIDGES WETS OF RT 219/...WHILE THE CENTRAL AND
SOUTHERN VALLEYS SEE A DUSTING TO PERHAPS A LITTLE OVER ONE HALF OF
AN INCH. EXPECT LITTLE OR NO SNOW TO THE NORTH OF INTERSTATE 80 LATE
TODAY AND TONIGHT. IT/S OFTEN A TRICKY CALL TRYING TO FORECAST THESE
WEAKLY FORCED...MOISTURE STARVED MESOSCALE EVENTS.
VERY LATE TONIGHT...ANY LINGERING PRECIP WILL BE IN THE FORM OF SNOW
SHOWERS AND CONFINED TO THE LAURELS.
TEMPS FOR THE REST OF THIS AFTN WILL BE IN THE 40S TO NEAR 50F IN
THE SOUTHEAST...BUT THE THICKENING CLOUDS WILL HOLD THE MAXES UNDER
40F OVER THE WRN MTNS. THIS WILL BE THE START OF THE DOWNTURN TO OUR
TEMPS.
COLDER AIR WILL BE ADVECTING INTO THE NW. LAKE ERIE IS PRETTY MUCH
FROZEN...SO MOISTURE FLUX WILL BE LOW. HOWEVER...THE MOISTURE FROM
THE OTHER LAKES UNDER THE CYCLONIC FLOW ALOFT WILL BE ABLE TO
GENERATE PLENTY OF CLOUDS AND A FEW SHSN WITH LOCALIZED LIGHT ACCUMS
OF AN INCH OR LESS. MINS TONIGHT /RANGING FROM 10-15F ACROSS THE
MTNS...AND LOWER TO MID 20S IN THE SE/ WILL BE NEAR NORMAL IN THE
SOUTH BUT ABOUT 5F BELOW NORMAL IN THE NRN MTS.
&&
.SHORT TERM /MONDAY/...
A RELATIVELY FLAT SHORTWAVE AND ASSOCIATED 850-700 MB THERMAL TROUGH
SLIDES EAST ACROSS THE CWA MONDAY. THERE WILL BE PLENTY OF CLOUDS
ACROSS THE NORTH AND WEST. LAKE EFFECT...AND OROGRAPHIC STRATUS AND
STRATO CU CLOUD LAYER TEMPS WILL BE SMACK IN THE MIDDLE OF THE
FAVORABLE THERMAL RIBBON FOR DENDRITIC GROWTH...SO EXPECT TO SEE
OCCASIONAL FLURRIES AND SCTD MTN SNOW SHOWERS WITH AREAS OF LIGHT
ACCUMS...MAINLY ON THE RIDGES OF THE LAURELS...AND NW MTNS TO THE
WEST OF ROUTE 219.
PERHAPS THE MOST NOTICEABLE WEATHER ELEMENT MONDAY WILL BE THE GUSTY
WNW WIND. SUSTAINED SPEEDS OF 15 TO 20 MPH AND GUSTS INTO THE L30S
ARE LIKELY. MAX TEMPS WILL VARY FROM THE UPPER TEENS TO AROUND 20F
IN THE NW. THE SE WILL HAVE SOME DOWNSLOPE AND LIKELY PLENTY OF
SUNSHINE /75-90 PERCENT SUN/ BUT A -14C 8H TEMP WILL MEAN THAT IT
WILL STRUGGLE TO GET INTO THE M30S.
WIND CHILLS WILL RANGE FROM ZERO TO 5 ABOVE AT TIMES ACROSS THE NW
MTNS AND LAURELS...TO AROUND 20F IN THE LOWER SUSQ VALLEY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
THE WORK WEEK WILL SEE THE RETURN OF COLDER AIR AND STRONG
NORTHWESTERLY FLOW. TEMPERATURES WILL GET SUCCESSIVELY COLDER AS
THE WEEK PROGRESSES. AS A RIDGE RE- ESTABLISHES ITSELF OVER THE
FAR WESTERN UNITED STATES...ALLOWING COLDER AIR TO PUSH SOUTHWARD
INTO THE GREAT LAKES AND NORTHEASTERN UNITED STATES.
A SECOND SYSTEM COULD SPREAD ANOTHER ROUND OF LIGHT SNOW ACROSS
PENNSYLVANIA EARLY TUESDAY...WITH A POTENTIALLY MORE SIGNIFICANT
SYSTEM POSSIBLY BRINGING ADDITIONAL SNOW TO THE REGION TUES NIGHT
INTO WEDNESDAY. KEPT POPS IN THE 30-40 PERCENT RANGE THROUGH MUCH
OF THIS PERIOD...AS CONFIDENCE IN THE TIMING AND DETAILS OF THESE
SYSTEMS IS LOW AT THIS RANGE.
THE 12Z GEFS SHOWS 850 TEMPS DROPPING TO -2SD FOR THU AND FRI...SO
IT LOOKS LIKE A COLD END TO NEXT WEEK IS IN STORE.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
SFC COLD FRONT HAS PUSHED TO THE SOUTH OF THE PENN/MD BORDER AT
MIDDAY. INCREASING DEEP LAYER LIFT WILL CAUSE CLOUDS TO OVERSPREAD
THE LAUREL HIGHLANDS AND NW MTNS LATE THIS AFTERNOON...AND THE REST
OF THE REGION TONIGHT.
INCREASING...DOWNSLOPE WESTERLY FLOW OF AROUND 10 KTS WILL COMBINE
WITH THE MODERATE TEMPS ALOFT TO PRODUCE BREAKS IN THE LAYERED MID
AND HIGH CLOUDS BUT NOTHING MORE THAN A SPRINKLE OR PASSING FLURRY
THIS AFTERNOON.
PERIODS OF MVFR...AND EVEN SOME BRIEF IFR...WILL DEVELOP IN SNOW
SHOWERS /MAINLY ACROSS THE LAUREL HIGHLANDS LATE TODAY...AND
TONIGHT/. SOMEWHAT LOWER PROBABILITY EXISTS FOR THESE FLIGHT
REDUCTIONS SPREADING INTO THE KMDT AND KLNS AREAS TONIGHT. KEPT
VSBYS JUST A TAD ABOVE MVFR AT KMDT...KLNS AND KTHV AS SOME AREAS
OF LIGHT RAIN/SNOW SPREAD ACROSS THE REGION THIS EVENING UNTIL
AROUND 05Z.
ELSEWHERE...ACROSS MUCH OF CENTRAL AND NRN PENN...GENERALLY VFR BKN
CIGS WILL PREVAIL WITH JUST SOME SPOTTY LIGHT RAIN/SNOW
SHOWERS...CHANGING TO SNOW SHOWERS TONIGHT.
OUTLOOK...
MON...MVFR/SHSN NW. VFR ELSEWHERE.
TUE...MVFR-IFR PSBL IN -SHSN. VFR ELSEWHERE.
WED...PSBL REDUCTIONS DUE TO LOW PRES DEVELOPING OVR NC MOVG
NEWD.
THUR...MVFR/SNSH NW. VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...CERU/EVANEGO
AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
923 PM CST MON FEB 24 2014
.UPDATE...
CLOUDS HAVE DEVELOPED QUICKLY OVER ARKANSAS THIS EVENING AS WARM
AIR IS OVERRUNNING THE COLDER AIR AT THE SFC. THE CLOUDS HAVE
PUSHED EAST AND NOW COVER MUCH OF THE MIDSOUTH. THE WEAK OVERRUNNING
PATTERN WILL PRODUCE AREAS OF LIGHT RAIN OVER MAINLY NORTH
MISSISSIPPI OVERNIGHT. TEMPERATURES HAVE EITHER HELD STEADY OR
HAVE GONE UP A COUPLE OF DEGREES SINCE THE CLOUDS HAVE PUSHED IN.
WILL UPDATE TO REMOVE MENTION OF SNOW AS TEMPERATURES WILL REMAIN
WELL ABOVE FREEZING AT AND ABOVE THE SFC TO KEEP PRECIPITATION
RAIN. WILL ALSO ADJUST SKY CONDITIONS TO CLOUDY. WILL KEEP 20 POPS
FROM MEMPHIS SOUTHWARD BUT LATEST HRRR INDICATES THAT MORE
DEVELOPMENT COULD OCCUR THAN OTHER MODELS ARE SUGGESTING. IF IT
PANS OUT THEN HIGHER POPS MAY BE NEEDED. WILL CONTINUE TO MONITOR
AND FUTURE UPDATES MAY BE NEEDED.
KRM
&&
.DISCUSSION... /ISSUED 329 PM CST MON FEB 24 2014/
TEMPERATURES ACROSS THE MIDSOUTH RANGE FROM THE MIDDLE 40S TO
MIDDLE 50S AROUND 10 TO 15 DEGREES COOLER THAN THEY WERE AT THIS
TIME YESTERDAY. MOST OF THE MIDSOUTH HAS SEEN ABUNDANT SUNSHINE
DURING THE DAY TODAY...BUT HIGH CLOUDS ARE NOW OVERSPREADING NORTH
MISSISSIPPI. SKIES WILL TURN MOSTLY CLOUDY ACROSS MOST OF THE
REGION OVERNIGHT KEEPING TEMPERATURES FROM COOLING QUITE AS MUCH
AS LAST NIGHT. MORNING LOWS TOMORROW WILL BE IN THE 30S ACROSS
MOST OF THE REGION...AND ABOVE FREEZING FOR THE SOUTHERN HALF OF
THE FORECAST AREA INCLUDING THE MEMPHIS METRO AREA.
TOMORROW...SURFACE WINDS WILL SHIFT MORE EASTERLY WITH WEST TO
NORTHWEST FLOW SETTING UP ALOFT. A STRONG MID LEVEL DISTURBANCE
WILL TRACK FROM NORTH TEXAS ACROSS ARKANSAS INTO NORTH MISSISSIPPI
LATE TOMORROW THROUGH EARLY WEDNESDAY. THERE IS SOME QUESTION
REGARDING HOW MUCH MOISTURE WILL STILL BE AVAILABLE LATE TUESDAY
NIGHT WHEN SUBFREEZING TEMPERATURES ARRIVE...ESPECIALLY IN WEST
TENNESSEE...THE MISSOURI BOOTHEEL AND NORTHEAST ARKANSAS FOR
FROZEN PRECIPITATION...BUT AT LEAST A BRIEF PERIOD OF SNOW OR A
RAIN SNOW MIX LOOKS POSSIBLE AREA WIDE. THE BEST CHANCE OF
ACCUMULATING SNOW LOOKS TO BE ACROSS NORTH MISSISSIPPI...BUT HERE
TEMPERATURES COLD ENOUGH FOR SNOW WILL NOT LIKELY ARRIVE UNTIL
WELL AFTER MIDNIGHT...OR EVEN UNTIL AROUND SUNRISE. DO NOT
ANTICIPATE THE NEED FOR ANY WINTER STORM
WARNINGS/WATCHES/ADVISORIES AT THIS TIME. HPC WINTER WEATHER
PRODUCTS DO NOT INCLUDE ANY FREEZING OR FROZEN PRECIPITATION.
MODELS LIQUID EQUIVALENT PRECIPITATION IS GENERALLY ONE TENTH OF
AN INCH OR LESS WHICH SHOULD NOT TRANSLATE TO MORE THAN A DUSTING
OF SNOW...AND THAT IS IN A BEST CASE SCENARIO WHERE ALL
PRECIPITATION FALLS AS SNOW AND IT DOES NOT MELT.
SURFACE HIGH PRESSURE WILL BUILD IN QUICKLY ON WEDNESDAY.
CONSIDERABLE SUNSHINE IS LIKELY BY THE EARLY AFTERNOON HOURS...BUT
NORTHERLY WIND WILL CURB AFTERNOON HIGHS KEEPING ALL OF THE
MIDSOUTH IN THE 30S...AND THE COLDEST LOCATIONS BELOW FREEZING.
THURSDAY WILL BEGIN VERY COLD WITH TEMPERATURES GENERALLY BETWEEN
15 AND 25 DEGREES BUT WARM INTO THE MID TO UPPER 40S DURING THE
AFTERNOON.
ANOTHER CHANCE OF PRECIPITATION WILL MOVE IN FRIDAY...GUIDANCE
SUGGESTS MULTIPLE PHASE CHANGES BETWEEN RAIN AND SNOW...OR A MIX
OF THE TWO AS TEMPERATURES WARM DURING THE DAY AND THEN COOL OFF
AGAIN FRIDAY NIGHT. THE OVERALL PATTERN LOOKS FAIRLY GOOD FOR A
MIDSOUTH SNOWFALL. A SURFACE LOW WILL TRACK FROM NORTH TEXAS
ACROSS CENTRAL ARKANSAS...BUT AT THIS TIME THICKNESSES DO NOT
SUPPORT ALL SNOW AND ACTUALLY RISE BY 30 METERS OR SO FROM MIDDAY
FRIDAY THROUGH MIDNIGHT. THE ECMWF SOLUTION IS EVEN WARMER THAN
THE GFS AND WOULD RESULT IN ALL RAIN.
SATURDAY LOOKS DRY WITH HIGHS RANGING FROM THE UPPER 30S TO UPPER
40S ACROSS MOST OF THE REGION. YET ANOTHER BRIEF CHANCE OF SNOW IS
IN THE FORECAST EARLY SUNDAY..MAINLY ACROSS NORTHERN...AREAS IF
MOISTURE ARRIVES BEFORE TEMPERATURES WARM. HIGHS SUNDAY SHOULD BE
WELL ABOVE FREEZING SO ANY SNOW THAT DOES FALL WILL MELT QUICKLY.
EARLY NEXT WEEK LOOKS WARMER AND RAINY.
&&
.AVIATION...
00Z TAF CYCLE
A DECK OF STRATOCU WILL PUSH INTO THE MIDSOUTH THIS EVENING.
EXPECT CIGS TO REMAIN VFR IN THE 3500-4500FT RANGE OVERNIGHT.
THERE IS SOME RISK OF MVFR CIGS AND A FEW SHRAS TOWARD BUT NOT
CONFIDENT ENOUGH TO MENTION IN TAFS ATTM. AS DRY AIR MOVES IN FROM
THE NORTH ON TUESDAY CLOUDS WILL CLEAR OUT OF KJBR AND
KMKL...AND AFTER THIS TAF PERIOD FOR KMEM AND KTUP. WINDS WILL
GENERALLY BE NE AT 5 KTS OVERNIGHT INCREASING TO 8-10 KTS TUESDAY.
SJM
&&
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1121 AM CST SUN FEB 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CST SUN FEB 23 2014
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING FROM THE EASTERN PACIFIC INTO ALASKA...A BROAD UPPER
LOW OVER THE CANADIAN ARCHIPELAGO...AND BROAD TROUGHING ACROSS ALL
OF SOUTHERN CANADA INTO THE UPPER MIDWEST. SHORTWAVES OF NOTE FOR
THIS FORECAST INCLUDE ONE OVER WEST CENTRAL BRITISH COLUMBIA...ONE
OVER CENTRAL ALBERTA...AND THE LAST AS PART OF THE UPPER LOW ON THE
WESTERN SIDE OF THE CANADIAN ARCHIPELAGO. A NORTHWEST 925MB FLOW
CONTINUES TO GRADUALLY DRAW COLDER IN OUT OF CANADA TOWARDS THE
FORECAST AREA...NOTED BY THE 00Z MPX SOUNDING AT -15C. THAT SAME
SOUNDING ALSO CONTINUES TO DEPICT PLENTY OF DRY AIR...RESULTING IN
CLEAR SKIES EARLY THIS MORNING. COMBINATION OF THE CLEAR SKIES AND
COOLING 925MB TEMPS HAS ALLOWED TEMPERATURES TO DROP INTO THE SINGLE
DIGITS ABOVE ZERO. IF THE 5 TO 15 MPH BREEZE WAS NOT PRESENT TO KEEP
THE AIR MIXED...TEMPERATURES WOULD PROBABLY BE A LOT COLDER.
OVERALL LITTLE CHANGE IS PROGGED BY MODELS TO OCCUR IN THE NEXT 24
HOURS IN TERMS OF THE UPPER LEVEL PATTERN OVER THE UPPER MIDWEST AND
THE FORECAST AREA. WE STILL REMAIN UNDER THE INFLUENCE OF A DRY
NORTHWEST LOW TO MID LEVEL FLOW...WHICH SHOULD HELP KEEP SKIES
MAINLY CLEAR THROUGH TODAY AND MUCH OF TONIGHT. THERE ARE SOME
INDICATIONS OF CIRRUS APPROACHING LOCATIONS WEST OF THE MISSISSIPPI
RIVER LATE TONIGHT...BUT THATS REALLY ABOUT IT FOR CLOUDS.
925MB TEMPS TODAY ARE FORECAST TO RANGE BETWEEN -13 AND -16C...ABOUT
1-2C COLDER THAN YESTERDAY. THEREFORE...WE SHOULD SEE HIGHS JUST
SLIGHTLY COOLER THAN YESTERDAY. SKIES STAYING CLEAR THROUGH
MUCH OF TONIGHT PLUS 925MB TEMPS FALLING TO -14 TO -19C...COLDEST
OVER WISCONSIN...SHOULD ALLOW FOR LOWS IN MOST LOCATIONS IN THE
SINGLE DIGITS BELOW ZERO. AGAIN...THERE LOOKS TO BE A PERSISTENT
NORTHWEST BREEZE THROUGH TONIGHT HELPING TO PREVENT DECOUPLING.
STILL...THE TYPICAL COLD SPOTS COULD TRY TO APPROACH -10F. WIND
CHILLS LOOK TO GET CLOSE TO ADVISORY CRITERIA...BUT TOO MARGINAL AT
THIS POINT TO ISSUE AN ADVISORY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 301 AM CST SUN FEB 23 2014
THE 2 MAIN IMPACTS REMAIN FOR THE LONG TERM...
1. POTENTIAL FOR SOME SNOW LATE MONDAY AFTERNOON AND NIGHT
2. THE BITTER COLD AIR...ESPECIALLY TUESDAY NIGHT AND BEYOND.
REGARDING IMPACT NUMBER 1...THE SHORTWAVES CURRENTLY OVER CENTRAL
BRITISH COLUMBIA AND ALBERTA REMAIN PROGGED TO PHASE TOGETHER OVER
THE DAKOTAS ON MONDAY...THEN QUICKLY SLIDE THROUGH THE FORECAST AREA
AROUND 06Z TUESDAY. MOISTURE IS LACKING FOR THESE SHORTWAVES...WITH
PRECIPITABLE WATER CLIMBING TO 0.1-0.2 OF AN INCH. HOWEVER...SOME
WEAK ISENTROPIC LIFT ON THE 275-280K SURFACES COMBINED WITH DPVA
AHEAD OF THE SHORTWAVES SHOULD BE ENOUGH TO SQUEEZE OUT SOME LIGHT
SNOW. SNOW SHOULD BE SOMEWHAT FLUFFY...THOUGH THE BULK OF THE LIFT
LOOKS TO OCCUR ABOVE THE DENDRITIC GROWTH ZONE. TIMING WISE...MODELS
CONTINUE TO SLOW DOWN THE SNOW MOVING INTO THE AREA...WITH THE
23.00Z NAM/GFS/CANADIAN/ECMWF KEEPING MUCH OF THE SNOW WEST OF THE
AREA PRIOR TO 00Z TUESDAY. ITS MORE OF A MONDAY NIGHT SNOW NOW. DID
RAISE CHANCES UP FOR MONDAY EVENING WEST OF THE MISSISSIPPI RIVER
WITH GOOD MODEL AGREEMENT FOR THE SNOW THEN. AFTER 06Z MONDAY...
MODELS DIVERGE ON HOW MUCH SNOW MIGHT BE LEFT WITH THE 23.00Z
GFS/CANADIAN DRY WHEREAS THE NAM AND ECMWF STILL HAVE SOME SNOW
LEFT. SPLIT THE DIFFERENCE AND HAVE SOME 20-30 PERCENT CHANCES FOR
NOW. IT APPEARS MUCH OF THIS HAS TO DO WITH THE TIMING OF THE PHASED
SHORTWAVE.
NOW IMPACT NUMBER 2...THE COLD. IN THE WAKE OF MONDAY NIGHTS
SHORTWAVE TROUGH...925MB TEMPS FALL TO -15 TO -20C. A SECOND AND
MORE POTENT COLD SURGE REMAINS PROGGED TO PLUNGE INTO THE AREA
TUESDAY NIGHT...DROPPING 925MB TEMPS TO -23 TO -25C BY 12Z
WEDNESDAY. THIS SURGE IS BEHIND THAT SHORTWAVE CURRENTLY OVER THE
CANADIAN ARCHIPELAGO. WIND CHILL ADVISORIES SEEM ALL BUT LIKELY
TUESDAY NIGHT INTO WEDNESDAY MORNING. A BRIEF BOUT OF WARM ADVECTION
IS SUGGESTED FOR WEDNESDAY AHEAD OF AN ARCTIC COLD FRONT
DROPPING SOUTH OUT OF CANADA...THOUGH IT APPEARS A BRISK WEST WIND
WILL ACCOMPANY IT. THEN ITS BACK TO THE COLD AS ANOTHER IMPRESSIVE
SURGE OF ARCTIC AIR DIVES SOUTH INTO THE REGION FOR THURSDAY ON
SOME BRISK NORTHWEST WINDS. 925MB TEMPS FROM THE 23.00Z GFS AND
ECMWF DROP TO -23 TO -27C BY 12Z THURSDAY...WHILE 850MB TEMPS
APPROACH -30C ACROSS OUR NORTH. THESE READINGS ARE NEARLY 3 STANDARD
DEVIATIONS BELOW NORMAL. BEYOND THURSDAY...MODELS BEGIN TO DIVERGE
A BIT WITH THE HANDLING OF THE COLD AIR. THE 23.00Z GFS TRIES TO
MODIFY THE COLD AIR SOMEWHAT FROM THE FLOW BECOMING MORE ZONAL
ACROSS THE NORTHERN TIER OF THE U.S.. THE 23.00Z ECMWF ALONG WITH
EXTRAPOLATION OF THE CANADIAN HAS THAT SAME ZONAL FLOW...JUST A
SMIDGE FURTHER SOUTH...WHICH RESULTS IN A CONTINUATION OF THE DEEP
FREEZE. FOR THE FORECAST LEANED A BIT CLOSER TOWARDS THE ECMWF.
OVERALL FOR TEMPERATURES TUESDAY THROUGH SATURDAY...STAYED CLOSE TO
A CONSENSUS OF 30 DAY BIAS CORRECTED GUIDANCE...WHICH PERFORMED WELL
IN PAST COLD SPELLS THIS WINTER. THURSDAY NIGHT COULD BE VERY COLD
WITH A SURFACE RIDGE PARKED OVERHEAD. WOULD NOT BE SURPRISED IF
SOME OF THE TYPICAL COLD SPOTS TO APPROACH -30F.
GIVEN HOW DEEP SOME OF THE FROST IS ALREADY...WATER MAINS UNDER
ROADS WILL NEED TO BE WATCHED CLOSELY. LUCKILY THE HIGHER SUN ANGLE
CAN HEAT THE TOP OF THE ROAD SURFACES MORE NOW THAN IN JANUARY...BUT
STILL THIS COLD AIR WILL NOT BE GOOD. THERE ARE STRONG INDICATIONS
TOO FROM THE CFS THAT THE BELOW NORMAL WEATHER COULD PERSIST THROUGH
ALL OF MARCH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1121 AM CST SUN FEB 23 2014
PLAN ON VFR CONDITIONS THROUGH THE PERIOD. HIGH PRESSURE
REMAINING ANCHORED ACROSS THE NORTHERN PLAINS THROUGH TOMORROW
WILL KEEP NORTHWESTERLY WINDS 10 TO 15 KTS AT THE TAF SITES. FOR
THIS AFTERNOON...25 KT GUSTS AT KRST DUE TO MIXING UP TO 925 MB
WILL SUBSIDE BY SUNSET. HOWEVER A TIGHT ENOUGH PRESSURE GRADIENT
WILL REMAIN IN PLACE TONIGHT TO KEEP BOUNDARY LAYER FROM
DECOUPLING. HIGH LEVEL CLOUDS AROUND 15 KFT SHOULD SPILL EASTWARD
OVER THE AREA LATE TOMORROW MORNING IN ADVANCE OF A PASSING
SHORTWAVE.
&&
.CLIMATE...
ISSUED AT 301 AM CST SUN FEB 23 2014
GIVEN ALL THE COLD AIR TO ROUND OUT THE MONTH OF FEBRUARY...HERE IS
HOW FEBRUARY AND THE WINTER WOULD STACK UP BASED ON THE CURRENT
FORECAST...
...FOR THE MONTH OF FEBRUARY...
LA CROSSE... 9.5 AVERAGE TEMPERATURE...4TH COLDEST
COLDER FEBRUARYS...
1873... 3.9
1936... 4.3
1899... 9.4
ROCHESTER... 6.9 AVERAGE TEMPERATURE...4TH COLDEST
COLDER FEBRUARYS...
1936... 0.5
1979... 5.7
1917... 6.0
...FOR THE WINTER...DECEMBER THROUGH FEBRUARY...
LA CROSSE... 11.6 AVERAGE TEMPERATURE...5TH COLDEST
COLDER WINTERS...
1872-1873... 8.4
1874-1875... 10.5
1977-1978... 11.4
1935-1936... 11.4
ROCHESTER... 8.9 AVERAGE TEMPERATURE...5TH COLDEST
COLDER WINTERS...
1978-1979... 5.6
1886-1887... 5.9
1935-1936... 8.1
1977-1978... 8.7
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION...ZT
CLIMATE......AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
530 AM CST SUN FEB 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CST SUN FEB 23 2014
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING FROM THE EASTERN PACIFIC INTO ALASKA...A BROAD UPPER
LOW OVER THE CANADIAN ARCHIPELAGO...AND BROAD TROUGHING ACROSS ALL
OF SOUTHERN CANADA INTO THE UPPER MIDWEST. SHORTWAVES OF NOTE FOR
THIS FORECAST INCLUDE ONE OVER WEST CENTRAL BRITISH COLUMBIA...ONE
OVER CENTRAL ALBERTA...AND THE LAST AS PART OF THE UPPER LOW ON THE
WESTERN SIDE OF THE CANADIAN ARCHIPELAGO. A NORTHWEST 925MB FLOW
CONTINUES TO GRADUALLY DRAW COLDER IN OUT OF CANADA TOWARDS THE
FORECAST AREA...NOTED BY THE 00Z MPX SOUNDING AT -15C. THAT SAME
SOUNDING ALSO CONTINUES TO DEPICT PLENTY OF DRY AIR...RESULTING IN
CLEAR SKIES EARLY THIS MORNING. COMBINATION OF THE CLEAR SKIES AND
COOLING 925MB TEMPS HAS ALLOWED TEMPERATURES TO DROP INTO THE SINGLE
DIGITS ABOVE ZERO. IF THE 5 TO 15 MPH BREEZE WAS NOT PRESENT TO KEEP
THE AIR MIXED...TEMPERATURES WOULD PROBABLY BE A LOT COLDER.
OVERALL LITTLE CHANGE IS PROGGED BY MODELS TO OCCUR IN THE NEXT 24
HOURS IN TERMS OF THE UPPER LEVEL PATTERN OVER THE UPPER MIDWEST AND
THE FORECAST AREA. WE STILL REMAIN UNDER THE INFLUENCE OF A DRY
NORTHWEST LOW TO MID LEVEL FLOW...WHICH SHOULD HELP KEEP SKIES
MAINLY CLEAR THROUGH TODAY AND MUCH OF TONIGHT. THERE ARE SOME
INDICATIONS OF CIRRUS APPROACHING LOCATIONS WEST OF THE MISSISSIPPI
RIVER LATE TONIGHT...BUT THATS REALLY ABOUT IT FOR CLOUDS.
925MB TEMPS TODAY ARE FORECAST TO RANGE BETWEEN -13 AND -16C...ABOUT
1-2C COLDER THAN YESTERDAY. THEREFORE...WE SHOULD SEE HIGHS JUST
SLIGHTLY COOLER THAN YESTERDAY. SKIES STAYING CLEAR THROUGH
MUCH OF TONIGHT PLUS 925MB TEMPS FALLING TO -14 TO -19C...COLDEST
OVER WISCONSIN...SHOULD ALLOW FOR LOWS IN MOST LOCATIONS IN THE
SINGLE DIGITS BELOW ZERO. AGAIN...THERE LOOKS TO BE A PERSISTENT
NORTHWEST BREEZE THROUGH TONIGHT HELPING TO PREVENT DECOUPLING.
STILL...THE TYPICAL COLD SPOTS COULD TRY TO APPROACH -10F. WIND
CHILLS LOOK TO GET CLOSE TO ADVISORY CRITERIA...BUT TOO MARGINAL AT
THIS POINT TO ISSUE AN ADVISORY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 301 AM CST SUN FEB 23 2014
THE 2 MAIN IMPACTS REMAIN FOR THE LONG TERM...
1. POTENTIAL FOR SOME SNOW LATE MONDAY AFTERNOON AND NIGHT
2. THE BITTER COLD AIR...ESPECIALLY TUESDAY NIGHT AND BEYOND.
REGARDING IMPACT NUMBER 1...THE SHORTWAVES CURRENTLY OVER CENTRAL
BRITISH COLUMBIA AND ALBERTA REMAIN PROGGED TO PHASE TOGETHER OVER
THE DAKOTAS ON MONDAY...THEN QUICKLY SLIDE THROUGH THE FORECAST AREA
AROUND 06Z TUESDAY. MOISTURE IS LACKING FOR THESE SHORTWAVES...WITH
PRECIPITABLE WATER CLIMBING TO 0.1-0.2 OF AN INCH. HOWEVER...SOME
WEAK ISENTROPIC LIFT ON THE 275-280K SURFACES COMBINED WITH DPVA
AHEAD OF THE SHORTWAVES SHOULD BE ENOUGH TO SQUEEZE OUT SOME LIGHT
SNOW. SNOW SHOULD BE SOMEWHAT FLUFFY...THOUGH THE BULK OF THE LIFT
LOOKS TO OCCUR ABOVE THE DENDRITIC GROWTH ZONE. TIMING WISE...MODELS
CONTINUE TO SLOW DOWN THE SNOW MOVING INTO THE AREA...WITH THE
23.00Z NAM/GFS/CANADIAN/ECMWF KEEPING MUCH OF THE SNOW WEST OF THE
AREA PRIOR TO 00Z TUESDAY. ITS MORE OF A MONDAY NIGHT SNOW NOW. DID
RAISE CHANCES UP FOR MONDAY EVENING WEST OF THE MISSISSIPPI RIVER
WITH GOOD MODEL AGREEMENT FOR THE SNOW THEN. AFTER 06Z MONDAY...
MODELS DIVERGE ON HOW MUCH SNOW MIGHT BE LEFT WITH THE 23.00Z
GFS/CANADIAN DRY WHEREAS THE NAM AND ECMWF STILL HAVE SOME SNOW
LEFT. SPLIT THE DIFFERENCE AND HAVE SOME 20-30 PERCENT CHANCES FOR
NOW. IT APPEARS MUCH OF THIS HAS TO DO WITH THE TIMING OF THE PHASED
SHORTWAVE.
NOW IMPACT NUMBER 2...THE COLD. IN THE WAKE OF MONDAY NIGHTS
SHORTWAVE TROUGH...925MB TEMPS FALL TO -15 TO -20C. A SECOND AND
MORE POTENT COLD SURGE REMAINS PROGGED TO PLUNGE INTO THE AREA
TUESDAY NIGHT...DROPPING 925MB TEMPS TO -23 TO -25C BY 12Z
WEDNESDAY. THIS SURGE IS BEHIND THAT SHORTWAVE CURRENTLY OVER THE
CANADIAN ARCHIPELAGO. WIND CHILL ADVISORIES SEEM ALL BUT LIKELY
TUESDAY NIGHT INTO WEDNESDAY MORNING. A BRIEF BOUT OF WARM ADVECTION
IS SUGGESTED FOR WEDNESDAY AHEAD OF AN ARCTIC COLD FRONT
DROPPING SOUTH OUT OF CANADA...THOUGH IT APPEARS A BRISK WEST WIND
WILL ACCOMPANY IT. THEN ITS BACK TO THE COLD AS ANOTHER IMPRESSIVE
SURGE OF ARCTIC AIR DIVES SOUTH INTO THE REGION FOR THURSDAY ON
SOME BRISK NORTHWEST WINDS. 925MB TEMPS FROM THE 23.00Z GFS AND
ECMWF DROP TO -23 TO -27C BY 12Z THURSDAY...WHILE 850MB TEMPS
APPROACH -30C ACROSS OUR NORTH. THESE READINGS ARE NEARLY 3 STANDARD
DEVIATIONS BELOW NORMAL. BEYOND THURSDAY...MODELS BEGIN TO DIVERGE
A BIT WITH THE HANDLING OF THE COLD AIR. THE 23.00Z GFS TRIES TO
MODIFY THE COLD AIR SOMEWHAT FROM THE FLOW BECOMING MORE ZONAL
ACROSS THE NORTHERN TIER OF THE U.S.. THE 23.00Z ECMWF ALONG WITH
EXTRAPOLATION OF THE CANADIAN HAS THAT SAME ZONAL FLOW...JUST A
SMIDGE FURTHER SOUTH...WHICH RESULTS IN A CONTINUATION OF THE DEEP
FREEZE. FOR THE FORECAST LEANED A BIT CLOSER TOWARDS THE ECMWF.
OVERALL FOR TEMPERATURES TUESDAY THROUGH SATURDAY...STAYED CLOSE TO
A CONSENSUS OF 30 DAY BIAS CORRECTED GUIDANCE...WHICH PERFORMED WELL
IN PAST COLD SPELLS THIS WINTER. THURSDAY NIGHT COULD BE VERY COLD
WITH A SURFACE RIDGE PARKED OVERHEAD. WOULD NOT BE SURPRISED IF
SOME OF THE TYPICAL COLD SPOTS TO APPROACH -30F.
GIVEN HOW DEEP SOME OF THE FROST IS ALREADY...WATER MAINS UNDER
ROADS WILL NEED TO BE WATCHED CLOSELY. LUCKILY THE HIGHER SUN ANGLE
CAN HEAT THE TOP OF THE ROAD SURFACES MORE NOW THAN IN JANUARY...BUT
STILL THIS COLD AIR WILL NOT BE GOOD. THERE ARE STRONG INDICATIONS
TOO FROM THE CFS THAT THE BELOW NORMAL WEATHER COULD PERSIST THROUGH
ALL OF MARCH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY)
ISSUED AT 530 AM CST SUN FEB 23 2014
DRY/COLD CANADIAN HIGH PRESSURE...WITH RIDGING INTO IA...WILL REMAIN
CENTERED OVER ALB/SASKAT TODAY/TONIGHT...WITH GOOD VFR CONDITIONS
EXPECTED THRU THE PERIOD INTO MONDAY. A MODEST PRESSURE GRADIENT
WILL REMAIN OVER THE AREA...FOR WEST TO NORTHWEST WINDS MOSTLY IN
THE 10 TO 15 KT RANGE THRU TONIGHT. STEEP LOW LEVEL LAPSE RATES AND
SOME DEEPER MIXING TO NEAR 925MB THIS AFTERNOON LOOKS TO RESULT IN
SOME GUSTINESS OF THE WINDS THIS AFTERNOON...MAINLY AT THE HIGHER
ELEVATION/OPEN COUNTRY SITES LIKE KRST. CONTINUED THE MENTION OF
WIND GUSTS AT KRST IN THE 19Z-24Z TIMEFRAME.
&&
.CLIMATE...
ISSUED AT 301 AM CST SUN FEB 23 2014
GIVEN ALL THE COLD AIR TO ROUND OUT THE MONTH OF FEBRUARY...HERE IS
HOW FEBRUARY AND THE WINTER WOULD STACK UP BASED ON THE CURRENT
FORECAST...
...FOR THE MONTH OF FEBRUARY...
LA CROSSE... 9.5 AVERAGE TEMPERATURE...4TH COLDEST
COLDER FEBRUARYS...
1873... 3.9
1936... 4.3
1899... 9.4
ROCHESTER... 6.9 AVERAGE TEMPERATURE...4TH COLDEST
COLDER FEBRUARYS...
1936... 0.5
1979... 5.7
1917... 6.0
...FOR THE WINTER...DECEMBER THROUGH FEBRUARY...
LA CROSSE... 11.6 AVERAGE TEMPERATURE...5TH COLDEST
COLDER WINTERS...
1872-1873... 8.4
1874-1875... 10.5
1977-1978... 11.4
1935-1936... 11.4
ROCHESTER... 8.9 AVERAGE TEMPERATURE...5TH COLDEST
COLDER WINTERS...
1978-1979... 5.6
1886-1887... 5.9
1935-1936... 8.1
1977-1978... 8.7
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RRS
CLIMATE......AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
301 AM CST SUN FEB 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CST SUN FEB 23 2014
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING FROM THE EASTERN PACIFIC INTO ALASKA...A BROAD UPPER
LOW OVER THE CANADIAN ARCHIPELAGO...AND BROAD TROUGHING ACROSS ALL
OF SOUTHERN CANADA INTO THE UPPER MIDWEST. SHORTWAVES OF NOTE FOR
THIS FORECAST INCLUDE ONE OVER WEST CENTRAL BRITISH COLUMBIA...ONE
OVER CENTRAL ALBERTA...AND THE LAST AS PART OF THE UPPER LOW ON THE
WESTERN SIDE OF THE CANADIAN ARCHIPELAGO. A NORTHWEST 925MB FLOW
CONTINUES TO GRADUALLY DRAW COLDER IN OUT OF CANADA TOWARDS THE
FORECAST AREA...NOTED BY THE 00Z MPX SOUNDING AT -15C. THAT SAME
SOUNDING ALSO CONTINUES TO DEPICT PLENTY OF DRY AIR...RESULTING IN
CLEAR SKIES EARLY THIS MORNING. COMBINATION OF THE CLEAR SKIES AND
COOLING 925MB TEMPS HAS ALLOWED TEMPERATURES TO DROP INTO THE SINGLE
DIGITS ABOVE ZERO. IF THE 5 TO 15 MPH BREEZE WAS NOT PRESENT TO KEEP
THE AIR MIXED...TEMPERATURES WOULD PROBABLY BE A LOT COLDER.
OVERALL LITTLE CHANGE IS PROGGED BY MODELS TO OCCUR IN THE NEXT 24
HOURS IN TERMS OF THE UPPER LEVEL PATTERN OVER THE UPPER MIDWEST AND
THE FORECAST AREA. WE STILL REMAIN UNDER THE INFLUENCE OF A DRY
NORTHWEST LOW TO MID LEVEL FLOW...WHICH SHOULD HELP KEEP SKIES
MAINLY CLEAR THROUGH TODAY AND MUCH OF TONIGHT. THERE ARE SOME
INDICATIONS OF CIRRUS APPROACHING LOCATIONS WEST OF THE MISSISSIPPI
RIVER LATE TONIGHT...BUT THATS REALLY ABOUT IT FOR CLOUDS.
925MB TEMPS TODAY ARE FORECAST TO RANGE BETWEEN -13 AND -16C...ABOUT
1-2C COLDER THAN YESTERDAY. THEREFORE...WE SHOULD SEE HIGHS JUST
SLIGHTLY COOLER THAN YESTERDAY. SKIES STAYING CLEAR THROUGH
MUCH OF TONIGHT PLUS 925MB TEMPS FALLING TO -14 TO -19C...COLDEST
OVER WISCONSIN...SHOULD ALLOW FOR LOWS IN MOST LOCATIONS IN THE
SINGLE DIGITS BELOW ZERO. AGAIN...THERE LOOKS TO BE A PERSISTENT
NORTHWEST BREEZE THROUGH TONIGHT HELPING TO PREVENT DECOUPLING.
STILL...THE TYPICAL COLD SPOTS COULD TRY TO APPROACH -10F. WIND
CHILLS LOOK TO GET CLOSE TO ADVISORY CRITERIA...BUT TOO MARGINAL AT
THIS POINT TO ISSUE AN ADVISORY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 301 AM CST SUN FEB 23 2014
THE 2 MAIN IMPACTS REMAIN FOR THE LONG TERM...
1. POTENTIAL FOR SOME SNOW LATE MONDAY AFTERNOON AND NIGHT
2. THE BITTER COLD AIR...ESPECIALLY TUESDAY NIGHT AND BEYOND.
REGARDING IMPACT NUMBER 1...THE SHORTWAVES CURRENTLY OVER CENTRAL
BRITISH COLUMBIA AND ALBERTA REMAIN PROGGED TO PHASE TOGETHER OVER
THE DAKOTAS ON MONDAY...THEN QUICKLY SLIDE THROUGH THE FORECAST AREA
AROUND 06Z TUESDAY. MOISTURE IS LACKING FOR THESE SHORTWAVES...WITH
PRECIPITABLE WATER CLIMBING TO 0.1-0.2 OF AN INCH. HOWEVER...SOME
WEAK ISENTROPIC LIFT ON THE 275-280K SURFACES COMBINED WITH DPVA
AHEAD OF THE SHORTWAVES SHOULD BE ENOUGH TO SQUEEZE OUT SOME LIGHT
SNOW. SNOW SHOULD BE SOMEWHAT FLUFFY...THOUGH THE BULK OF THE LIFT
LOOKS TO OCCUR ABOVE THE DENDRITIC GROWTH ZONE. TIMING WISE...MODELS
CONTINUE TO SLOW DOWN THE SNOW MOVING INTO THE AREA...WITH THE
23.00Z NAM/GFS/CANADIAN/ECMWF KEEPING MUCH OF THE SNOW WEST OF THE
AREA PRIOR TO 00Z TUESDAY. ITS MORE OF A MONDAY NIGHT SNOW NOW. DID
RAISE CHANCES UP FOR MONDAY EVENING WEST OF THE MISSISSIPPI RIVER
WITH GOOD MODEL AGREEMENT FOR THE SNOW THEN. AFTER 06Z MONDAY...
MODELS DIVERGE ON HOW MUCH SNOW MIGHT BE LEFT WITH THE 23.00Z
GFS/CANADIAN DRY WHEREAS THE NAM AND ECMWF STILL HAVE SOME SNOW
LEFT. SPLIT THE DIFFERENCE AND HAVE SOME 20-30 PERCENT CHANCES FOR
NOW. IT APPEARS MUCH OF THIS HAS TO DO WITH THE TIMING OF THE PHASED
SHORTWAVE.
NOW IMPACT NUMBER 2...THE COLD. IN THE WAKE OF MONDAY NIGHTS
SHORTWAVE TROUGH...925MB TEMPS FALL TO -15 TO -20C. A SECOND AND
MORE POTENT COLD SURGE REMAINS PROGGED TO PLUNGE INTO THE AREA
TUESDAY NIGHT...DROPPING 925MB TEMPS TO -23 TO -25C BY 12Z
WEDNESDAY. THIS SURGE IS BEHIND THAT SHORTWAVE CURRENTLY OVER THE
CANADIAN ARCHIPELAGO. WIND CHILL ADVISORIES SEEM ALL BUT LIKELY
TUESDAY NIGHT INTO WEDNESDAY MORNING. A BRIEF BOUT OF WARM ADVECTION
IS SUGGESTED FOR WEDNESDAY AHEAD OF AN ARCTIC COLD FRONT
DROPPING SOUTH OUT OF CANADA...THOUGH IT APPEARS A BRISK WEST WIND
WILL ACCOMPANY IT. THEN ITS BACK TO THE COLD AS ANOTHER IMPRESSIVE
SURGE OF ARCTIC AIR DIVES SOUTH INTO THE REGION FOR THURSDAY ON
SOME BRISK NORTHWEST WINDS. 925MB TEMPS FROM THE 23.00Z GFS AND
ECMWF DROP TO -23 TO -27C BY 12Z THURSDAY...WHILE 850MB TEMPS
APPROACH -30C ACROSS OUR NORTH. THESE READINGS ARE NEARLY 3 STANDARD
DEVIATIONS BELOW NORMAL. BEYOND THURSDAY...MODELS BEGIN TO DIVERGE
A BIT WITH THE HANDLING OF THE COLD AIR. THE 23.00Z GFS TRIES TO
MODIFY THE COLD AIR SOMEWHAT FROM THE FLOW BECOMING MORE ZONAL
ACROSS THE NORTHERN TIER OF THE U.S.. THE 23.00Z ECMWF ALONG WITH
EXTRAPOLATION OF THE CANADIAN HAS THAT SAME ZONAL FLOW...JUST A
SMIDGE FURTHER SOUTH...WHICH RESULTS IN A CONTINUATION OF THE DEEP
FREEZE. FOR THE FORECAST LEANED A BIT CLOSER TOWARDS THE ECMWF.
OVERALL FOR TEMPERATURES TUESDAY THROUGH SATURDAY...STAYED CLOSE TO
A CONSENSUS OF 30 DAY BIAS CORRECTED GUIDANCE...WHICH PERFORMED WELL
IN PAST COLD SPELLS THIS WINTER. THURSDAY NIGHT COULD BE VERY COLD
WITH A SURFACE RIDGE PARKED OVERHEAD. WOULD NOT BE SURPRISED IF
SOME OF THE TYPICAL COLD SPOTS TO APPROACH -30F.
GIVEN HOW DEEP SOME OF THE FROST IS ALREADY...WATER MAINS UNDER
ROADS WILL NEED TO BE WATCHED CLOSELY. LUCKILY THE HIGHER SUN ANGLE
CAN HEAT THE TOP OF THE ROAD SURFACES MORE NOW THAN IN JANUARY...BUT
STILL THIS COLD AIR WILL NOT BE GOOD. THERE ARE STRONG INDICATIONS
TOO FROM THE CFS THAT THE BELOW NORMAL WEATHER COULD PERSIST THROUGH
ALL OF MARCH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1110 PM CST SAT FEB 22 2014
VERY LITTLE CHANGE IN CONDITIONS EXPECTED THROUGH SUNDAY EVENING.
HIGH PRESSURE WILL REMAIN CENTERED OVER SASKATCHEWAN WITH THE
RIDGE FROM THE HIGH EXTENDING SOUTHEAST INTO IOWA AND MISSOURI
WHILE LOW PRESSURE REMAINS CENTERED NEAR HUDSONS BAY. THE GRADIENT
BETWEEN THESE TWO FEATURES WILL KEEP THE WINDS OUT OF THE WEST TO
NORTHWEST AT SPEEDS OF 10 TO 15 KNOTS. COULD GET A LITTLE GUSTY
SUNDAY AFTERNOON AT KRST AND HAVE INCLUDED THESE IN THE FORECAST
BEFORE THE INVERSION DEVELOPS AND CUTS OFF THE MIXING EARLY IN THE
EVENING.
&&
.CLIMATE...
ISSUED AT 301 AM CST SUN FEB 23 2014
GIVEN ALL THE COLD AIR TO ROUND OUT THE MONTH OF FEBRUARY...HERE IS
HOW FEBRUARY AND THE WINTER WOULD STACK UP BASED ON THE CURRENT
FORECAST...
...FOR THE MONTH OF FEBRUARY...
LA CROSSE... 9.5 AVERAGE TEMPERATURE...4TH COLDEST
COLDER FEBRUARYS...
1873... 3.9
1936... 4.3
1899... 9.4
ROCHESTER... 6.9 AVERAGE TEMPERATURE...4TH COLDEST
COLDER FEBRUARYS...
1936... 0.5
1979... 5.7
1917... 6.0
...FOR THE WINTER...DECEMBER THROUGH FEBRUARY...
LA CROSSE... 11.6 AVERAGE TEMPERATURE...5TH COLDEST
COLDER WINTERS...
1872-1873... 8.4
1874-1875... 10.5
1977-1978... 11.4
1935-1936... 11.4
ROCHESTER... 8.9 AVERAGE TEMPERATURE...5TH COLDEST
COLDER WINTERS...
1978-1979... 5.6
1886-1887... 5.9
1935-1936... 8.1
1977-1978... 8.7
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
CLIMATE...AJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
716 PM MST MON FEB 24 2014
.UPDATE...
ISSUED AT 714 PM MST MON FEB 24 2014
HAD TO DO AN UPDATE ON MIN TEMPERATURES THIS EVENING...ESPECIALLY
EAST OF THE LARAMIE RANGE. TEMPERATURES AT THE OFFICE HERE IN
CHEYENNE ALREADY AT 9 AND DROPPING WITH SIGLE DIGITS IN THE
PANHANDLE. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 345 PM MST MON FEB 24 2014
FRONT HAS PASSED ACROSS THE PLAINS WITH NORTHERLY WINDS AND LOW
CLOUDS FILLING IN BEHIND IT. THERE WAS A DRAMATIC DROP IN TEMPS
ALONG THE COLORADO BORDER WITH THE FROPA...AS PREFRONTAL
DOWNSLOPING WESTERLY WINDS WERE REPLACED BY THE COLD NORTHERLIES.
SOME LIGHT SNOW HAS BEEN REPORTED AT CHADRON OVER THE PAST FEW
HOURS WITH GENERALLY DEEPER LAYER LIFT STRETCHING FROM THE
NORTHERN PANHANDLE OFF TO THE NORTHEAST. COULD BE SOME LIGHT SNOW
SHOWERS ACROSS THE PLAINS OVERNIGHT WITH LLVL LIFT...BUT
ACCUMULATIONS WILL BE REALLY LIGHT. THE OTHER STORY THIS AFTN IS
THAT THE WINDS HAVE FINALLY WEAKENED ACROSS THE ARLINGTON AREA AND
LARAMIE VALLEY. STILL COULD BE SOME GUSTS TO 40-50 MPH THROUGH
SUNSET BUT WITH RAPID PRESSURE RISES TO THE EAST OF THE LARAMIE
RANGE AND THE 700MB CAG-CPR GRADIENT DROPPING TO 40 METERS BY 12Z
TUES...NOT EXPECTING THE STRONG WESTERLY WINDS TO RETURN TO THE
WIND PRONE AREAS THROUGH AT LEAST THE SHORT TERM.
THE MODELS STILL SHOW A SHORTWAVE DROPPING SOUTHEASTWARD FROM
MONTANA INTO NEBRASKA DURING THE DAY ON TUESDAY. THERE WILL BE
ABOUT A 6-HR PERIOD FROM LATE TUESDAY MORNING INTO THE AFTERNOON
THAT SNOW WILL BE LIKELY ACROSS THE CWA. THIS IS SHAPING UP TO BE
A WIDESPREAD LIGHT SNOWFALL EVENT...WITH MANY LOWER ELEVATION
LOCATIONS GETTING 1 TO 4 INCHES. THE SHORT DURATION OF THE EVENT
ALONG WITH WEAKER UPWARD MOTION THROUGH THE LOW AND MID LEVELS
(COMPARED TO THIS PAST WEEKEND EVENT) SHOULD KEEP MOST AREAS BELOW
ADVISORY LEVEL AMOUNTS. THE MTNS WILL GENERALLY SEE 5 TO 7 INCHES.
SNOW QUICKLY ENDS BY EVENING AS SUBSIDENCE KICKS IN BEHIND THE
SHORTWAVE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 345 PM MST MON FEB 24 2014
THE MEDIUM RANGE WILL BE CONSIST OF THE TALE OF TWO AIR MASSES. THE
FIRST AIR MASS WILL YIELD A RELATIVELY BENIGN PERIOD WEDNESDAY AND
THURSDAY AS NORTHWEST FLOW DRIES AND BECOMES LESS CYCLONIC. AT THE
SFC...THE QUASISTATIONARY BOUNDARY WILL RETREAT TO THE EAST BOTH OF
THESE DAYS AS WELL. SO ALTHOUGH SOMEWHAT BREEZY...EXPECT MOSTLY DRY
CONDITIONS TO PREVAIL FOR BOTH DAYS WITH HIGH TEMPERATURES GENERALLY
IN THE 40S OVR SE WY AND 30S OVR THE WRN NEBRASKA PANHANDLE.
THIS ALL WILL BEGIN TO CHANGE ON THURSDAY AS SHORTWAVE ENERGY DIVES
SOUTHEAST THRU THE FOUR CORNERS. MOISTURE ASSOCIATED WITH THIS FTR
WILL BRING A RETURN TO PRECIP CHANCES AREAS ALONG AND WEST OF THE
LARAMIE RANGE. ADDITIONALLY...SFC PRESSURE FALLS TO THE SOUTH
COMBINED WITH THE NEXT ARCTIC PINWHEELING AROUND THE HUDSON BAY LOW
WILL RESULT IN STRONG LLVL CAA AND RESULTANT FROPA. 12Z MODELS ARE
CONSISTENT IN FROPA TIMING OCCURRING FRIDAY MORNING. THIS COLD FRONT
WILL AGAIN PULL UP STATIONARY NR THE DIVIDE AS THE ARCTIC AIR MASS
HANGS UP ON THE TERRAIN. ALOFT...WEST/SOUTHWEST FLOW FILLED WITH
PACIFIC MOISTURE WILL PERSISTENTLY OVER-RUN THIS LLVL COLD DOME
SETTING THE STAGE FOR WHAT LOOKS TO BE A SNOWY PERIOD BEGINNING LATE
THURSDAY THROUGH SATURDAY NIGHT. DETAILS ARE STILL TOO BLURRY TO
START TALKING ABOUT ACCUMULATIONS JUST YET...BUT GIVEN THE EVENTS
LONG DURATION WOULD EXPECT MODERATE SNOW AMOUNTS AT A MINIMUM. HAVE
CONTINUED TO BOOST SNOW CHANCES DURING THIS PERIOD PRETTY MUCH
AREA-WIDE AS CONFIDENCE GROWS. THE OTHER IMPACT FROM FROPA WILL BE
THE VERY COLD AIR ASSOCIATED WITH THE ARCTIC AIR MASS. AREAS
NORTHEAST OF THE NORTH PLATTE RIVER VALLEY WILL ONLY REACH THE LOWER
20S ON FRIDAY AND SINGLE DIGITS ON SATURDAY AND SUNDAY.
THE PATTERN WILL BECOME LESS ACTIVE AND MORE ZONAL FOR LATE IN THE
WEEKEND AND EARLY NEXT WEEK. HOWEVER...DID KEEP SMALL SNOW CHANCES
GOING FOR THIS LATTER PERIODS AS THE MODELS ARE STILL MEANDERING
THAT BOUNDARY IN THE VICINITY OF THE FRONT RANGE. TEMPERATURES TRY
TO EVER SO SLOWLY WARM MONDAY...BUT WILL STILL REMAIN BELOW
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY AFTERNOON)
ISSUED AT 417 PM MST MON FEB 24 2014
TRICKY FORECAST FOR THE 00Z TAFS. GUIDANCE SHOWING WINDS TURNING
MORE WESTERLY...WHICH WOULD CLEAR OUT MOST CEILINGS. BUT HERE AT
KCYS...DO NOT THINK THAT WILL HAPPEN. WINDS TURN MORE
SOUTHEASTERLY...WHICH IS A GOOD IFR PRODUCER HERE. HRRR GUIDANCE
CONFIRMS THAT AS WELL WITH IFR/LIFR CONTINUING WELL PAST 08Z
TONIGHT. WILL FOLLOW ITS GUIDANCE ON THE TAFS. RADAR MOSAIC
SHOWING THE KCDR SHOULD STAY DOWN FOR A WHILE IN LIGHT TO MODERATE
SNOW AS WELL. FOR TUESDAY...ANOTHER PUSH OF THE ARCTIC BOUNDARY TO
THE SOUTHWEST WILL BRING WIDESPREAD IFR/LIFR INTO THE PANHANDLE
AND SOUTHEAST WYOMING AS THE FRONT PUSHES WEST OF THE LARAMIE
RANGE.
&&
.FIRE WEATHER...
ISSUED AT 345 PM MST MON FEB 24 2014
NO FIRE WEATHER CONCERNS THROUGH THE END OF THE WEEK. WIDESPREAD
SNOW COVER STILL EXISTS ACROSS MUCH OF THE NEBRASKA PANHANDLE.
ANOTHER ROUND OF SNOW IS EXPECTED TUESDAY MORNING THROUGH THE
EVENING. TEMPERATURES WILL GENERALLY BE BELOW NORMAL THROUGH THE
UPCOMING WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLAYCOMB
SHORT TERM...FINCH
LONG TERM...HAHN
AVIATION...CLAYCOMB
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
421 PM MST MON FEB 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 345 PM MST MON FEB 24 2014
FRONT HAS PASSED ACROSS THE PLAINS WITH NORTHERLY WINDS AND LOW
CLOUDS FILLING IN BEHIND IT. THERE WAS A DRAMATIC DROP IN TEMPS
ALONG THE COLORADO BORDER WITH THE FROPA...AS PREFRONTAL
DOWNSLOPING WESTERLY WINDS WERE REPLACED BY THE COLD NORTHERLIES.
SOME LIGHT SNOW HAS BEEN REPORTED AT CHADRON OVER THE PAST FEW
HOURS WITH GENERALLY DEEPER LAYER LIFT STRETCHING FROM THE
NORTHERN PANHANDLE OFF TO THE NORTHEAST. COULD BE SOME LIGHT SNOW
SHOWERS ACROSS THE PLAINS OVERNIGHT WITH LLVL LIFT...BUT
ACCUMULATIONS WILL BE REALLY LIGHT. THE OTHER STORY THIS AFTN IS
THAT THE WINDS HAVE FINALLY WEAKENED ACROSS THE ARLINGTON AREA AND
LARAMIE VALLEY. STILL COULD BE SOME GUSTS TO 40-50 MPH THROUGH
SUNSET BUT WITH RAPID PRESSURE RISES TO THE EAST OF THE LARAMIE
RANGE AND THE 700MB CAG-CPR GRADIENT DROPPING TO 40 METERS BY 12Z
TUES...NOT EXPECTING THE STRONG WESTERLY WINDS TO RETURN TO THE
WIND PRONE AREAS THROUGH AT LEAST THE SHORT TERM.
THE MODELS STILL SHOW A SHORTWAVE DROPPING SOUTHEASTWARD FROM
MONTANA INTO NEBRASKA DURING THE DAY ON TUESDAY. THERE WILL BE
ABOUT A 6-HR PERIOD FROM LATE TUESDAY MORNING INTO THE AFTERNOON
THAT SNOW WILL BE LIKELY ACROSS THE CWA. THIS IS SHAPING UP TO BE
A WIDESPREAD LIGHT SNOWFALL EVENT...WITH MANY LOWER ELEVATION
LOCATIONS GETTING 1 TO 4 INCHES. THE SHORT DURATION OF THE EVENT
ALONG WITH WEAKER UPWARD MOTION THROUGH THE LOW AND MID LEVELS
(COMPARED TO THIS PAST WEEKEND EVENT) SHOULD KEEP MOST AREAS BELOW
ADVISORY LEVEL AMOUNTS. THE MTNS WILL GENERALLY SEE 5 TO 7 INCHES.
SNOW QUICKLY ENDS BY EVENING AS SUBSIDENCE KICKS IN BEHIND THE
SHORTWAVE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 345 PM MST MON FEB 24 2014
THE MEDIUM RANGE WILL BE CONSIST OF THE TALE OF TWO AIR MASSES. THE
FIRST AIR MASS WILL YIELD A RELATIVELY BENIGN PERIOD WEDNESDAY AND
THURSDAY AS NORTHWEST FLOW DRIES AND BECOMES LESS CYCLONIC. AT THE
SFC...THE QUASISTATIONARY BOUNDARY WILL RETREAT TO THE EAST BOTH OF
THESE DAYS AS WELL. SO ALTHOUGH SOMEWHAT BREEZY...EXPECT MOSTLY DRY
CONDITIONS TO PREVAIL FOR BOTH DAYS WITH HIGH TEMPERATURES GENERALLY
IN THE 40S OVR SE WY AND 30S OVR THE WRN NEBRASKA PANHANDLE.
THIS ALL WILL BEGIN TO CHANGE ON THURSDAY AS SHORTWAVE ENERGY DIVES
SOUTHEAST THRU THE FOUR CORNERS. MOISTURE ASSOCIATED WITH THIS FTR
WILL BRING A RETURN TO PRECIP CHANCES AREAS ALONG AND WEST OF THE
LARAMIE RANGE. ADDITIONALLY...SFC PRESSURE FALLS TO THE SOUTH
COMBINED WITH THE NEXT ARCTIC PINWHEELING AROUND THE HUDSON BAY LOW
WILL RESULT IN STRONG LLVL CAA AND RESULTANT FROPA. 12Z MODELS ARE
CONSISTENT IN FROPA TIMING OCCURRING FRIDAY MORNING. THIS COLD FRONT
WILL AGAIN PULL UP STATIONARY NR THE DIVIDE AS THE ARCTIC AIR MASS
HANGS UP ON THE TERRAIN. ALOFT...WEST/SOUTHWEST FLOW FILLED WITH
PACIFIC MOISTURE WILL PERSISTENTLY OVER-RUN THIS LLVL COLD DOME
SETTING THE STAGE FOR WHAT LOOKS TO BE A SNOWY PERIOD BEGINNING LATE
THURSDAY THROUGH SATURDAY NIGHT. DETAILS ARE STILL TOO BLURRY TO
START TALKING ABOUT ACCUMULATIONS JUST YET...BUT GIVEN THE EVENTS
LONG DURATION WOULD EXPECT MODERATE SNOW AMOUNTS AT A MINIMUM. HAVE
CONTINUED TO BOOST SNOW CHANCES DURING THIS PERIOD PRETTY MUCH
AREA-WIDE AS CONFIDENCE GROWS. THE OTHER IMPACT FROM FROPA WILL BE
THE VERY COLD AIR ASSOCIATED WITH THE ARCTIC AIR MASS. AREAS
NORTHEAST OF THE NORTH PLATTE RIVER VALLEY WILL ONLY REACH THE LOWER
20S ON FRIDAY AND SINGLE DIGITS ON SATURDAY AND SUNDAY.
THE PATTERN WILL BECOME LESS ACTIVE AND MORE ZONAL FOR LATE IN THE
WEEKEND AND EARLY NEXT WEEK. HOWEVER...DID KEEP SMALL SNOW CHANCES
GOING FOR THIS LATTER PERIODS AS THE MODELS ARE STILL MEANDERING
THAT BOUNDARY IN THE VICINITY OF THE FRONT RANGE. TEMPERATURES TRY
TO EVER SO SLOWLY WARM MONDAY...BUT WILL STILL REMAIN BELOW
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY AFTERNOON)
ISSUED AT 417 PM MST MON FEB 24 2014
TRICKY FORECAST FOR THE 00Z TAFS. GUIDANCE SHOWING WINDS TURNING
MORE WESTERLY...WHICH WOULD CLEAR OUT MOST CEILINGS. BUT HERE AT
KCYS...DO NOT THINK THAT WILL HAPPEN. WINDS TURN MORE
SOUTHEASTERLY...WHICH IS A GOOD IFR PRODUCER HERE. HRRR GUIDANCE
CONFIRMS THAT AS WELL WITH IFR/LIFR CONTINUING WELL PAST 08Z
TONIGHT. WILL FOLLOW ITS GUIDANCE ON THE TAFS. RADAR MOSAIC
SHOWING THE KCDR SHOULD STAY DOWN FOR A WHILE IN LIGHT TO MODERATE
SNOW AS WELL. FOR TUESDAY...ANOTHER PUSH OF THE ARCTIC BOUNDARY TO
THE SOUTHWEST WILL BRING WIDESPREAD IFR/LIFR INTO THE PANHANDLE
AND SOUTHEAST WYOMING AS THE FRONT PUSHES WEST OF THE LARAMIE
RANGE.
&&
.FIRE WEATHER...
ISSUED AT 345 PM MST MON FEB 24 2014
NO FIRE WEATHER CONCERNS THROUGH THE END OF THE WEEK. WIDESPREAD
SNOW COVER STILL EXISTS ACROSS MUCH OF THE NEBRASKA PANHANDLE.
ANOTHER ROUND OF SNOW IS EXPECTED TUESDAY MORNING THROUGH THE
EVENING. TEMPERATURES WILL GENERALLY BE BELOW NORMAL THROUGH THE
UPCOMING WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...HAHN
AVIATION...CLAYCOMB
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1032 PM MST MON FEB 24 2014
.UPDATE...
ISSUED AT 520 PM MST MON FEB 24 2014
UPDATED FORECAST TO END RED FLAG WARNING AND BLOWING DUST
ADVISORIES. ALSO BUMPED UP TIMING OF FRONT INTO SOUTHEAST COLORADO
TRENDING FORECAST TOWARDS THE FASTER HRRR. GUSTS IN NORTHEAST
COLORADO ARE AROUND 30-40KTS BEHIND THE FRONT...AND TEMPERATURES ARE IN
THE UPPER 20S. HRRR BRINGS THE FRONT THROUGH MOST OF SOUTHEAST
COLORADO BY 03Z...AND SHOULD BRING A STARK CHANGE ONCE IT BLOWS
THROUGH. GRIDS ATTEMPT TO FINE TUNE THESE DETAILS BETTER. -KT
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 252 PM MST MON FEB 24 2014
CURRENTLY...WESTERLY FLOW HAS ALLOWED FOR STRONG MIXING THIS
AFTERNOON ACROSS THE I-25 CORRIDOR. THIS HAS HELP TEMPERATURES RISE
INTO THE UPPER 60S TO LOWER 70S. WINDS ARE GUSTY...WITH GUSTS 25 TO
35 KTS SO FAR...ESPECIALLY OVER THE SOUTHERN I-25 CORRIDOR.
HUMIDITY VALUES ARE ALSO RUNNING AROUND 10 PERCENT AND EXTREME FIRE
DANGER IS PRESENT. HAVE NOT SEEN ANY REPORTS OF BLOWING DUST YET
BUT THERE WILL LIKELY BE SOME IN WIND PRONE AREAS...FROM PUEBLO TO
TRINIDAD. FURTHER EAST...CLOUDS AND LIGHT EASTERLY FLOW HAVE HELD
TEMPERATURES DOWN THIS AFTERNOON...WITH MID 40S FOR LA JUNTA AND
LAMAR. HOW WARM IT GETS DOWN THE FAR EASTERN ARKANSAS RIVER BASIN
WILL DEPEND ON CLEARING AND HOW FAR WESTERLIES PUSH THE WARMER AIR.
TONIGHT...A STRONG COLD FRONT CURRENTLY ENTERING NORTHERN COLORADO
WILL PROGRESS QUICKLY SOUTH ACROSS THE EASTERN PLAINS THIS EVENING.
EXPECT BREEZY NORTH WINDS BEHIND THE FRONT WHICH WILL ADVECT COLD
AIR INTO THE REGION. EXPECT TEMPERATURES TO FALL RAPIDLY BEHIND THE
FRONT. ONCE THE FRONT PASSES...EXPECT LOW LEVEL FLOW TO SWING
SOUTHEASTERLY. THIS WILL ALLOW LOW STRATUS AND FOG TO DEVELOP OVER
PORTIONS OF THE EASTERN PLAINS LATE TONIGHT INTO TUESDAY MORNING.
WHILE THE AIR MASS IS SHALLOW...PATCHY AREAS OF FREEZING DRIZZLE CAN
NOT BE RULED OUT AS WELL. ANY FOG OR FREEZING DRIZZLE COULD HAMPER
DRIVING CONDITIONS ACROSS EL PASO COUNTY...AND DOWN THE ARKANSAS
RIVER BASIN FOR TUESDAY MORNINGS COMMUTE. LIGHT SNOW IS EXPECTED TO
MOVE INTO THE CENTRAL MOUNTAINS AFTER MIDNIGHT WITH A QUICK INCH
POSSIBLE BY TUESDAY MORNING.
TUESDAY...THE MAIN FORECAST CHALLENGE WILL BE TEMPERATURES. HAVE
TRENDED AFTERNOON HIGHS DOWN WITH MOST AREAS STRUGGLING TO MAKE IT
OUT OF THE 30S ACROSS THE EASTERN PLAINS. THE EXCEPTION WILL LIKELY
BE THE LEE SLOPES OF THE EASTERN MOUNTAINS...WHERE SOME AFTERNOON
MIXING AND CLEARING OF CLOUD COVER WILL HELP BOOST HIGHS INTO THE
40S. IF CLOUDS CAN CLEAR...AND WE SEE BETTER AFTERNOON MIXING THAN
IS ANTICIPATED...AREAS OVER THE PLAINS COULD BE A BIT WARMER. BY
THE LATE AFTERNOON...ANOTHER COLD FRONT WILL PUSH SOUTH INTO EASTERN
COLORADO. ALL MODELS DEVELOP LIGHT PRECIPITATION ACROSS THE PALMER
DIVIDE BY MID AFTERNOON...AND SPREAD IT SOUTH INTO THE HIGHWAY 50
CORRIDOR BY SUNSET. AREAS OVER TELLER COUNTY WILL LIKELY SEE AN
INCH OR SO OF SNOW DURING THE LATE AFTERNOON. SNOW WILL BE LIGHT
OVER THE CENTRAL MOUNTAINS DURING THE MORNING HOURS AND PICK UP IN
INTENSITY DURING THE AFTERNOON. AN ADDITIONAL 1 TO 3 INCHES ARE
POSSIBLE BY TUESDAY EVENING FOR THE CENTRAL MOUNTAINS. MOZLEY
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 252 PM MST MON FEB 24 2014
...WEEKEND STORM STILL LOOKS GOOD...ESPECIALLY FOR THE CONTDVD...
TUESDAY NIGHT...
DISTURBANCE WILL BE MOVING ACROSS THE AREA AND WILL LIKELY BRING
SOME LIGHT SNOW TO AREAS GENERALLY NORTH OF A LINE FROM SALIDA TO
PUEBLO TO LAMAR. BEST CHANCE OF PRECIP WILL BE OVER THE CENTRAL MTNS
AND THE PIKES PEAK REGION. SNOWFALL AMOUNTS OVER THE C MTNS WILL BE
2-4" WITH 1-3" OVER TELLER COUNTY AND POSSIBLY AN INCH OR TWO OVER N
EL PASO COUNTY. THERE COULD BE SOME COMMUTING ISSUES IN EL PASO
COUNTY LATE TOMORROW AFTERNOON. THIS WILL BE A QUICK MOVING EVENT
AND BY SUNRISE WED WE SHOULD BE SEEING CLEARING SKIES OVER MOST OF
THE REGION.
WED-WED NITE...
AREA WILL BE IN-BETWEEN SYSTEMS. SNOW SHOWERS WILL BE POSSIBLE OVER
THE CONTDVD WITH OTHER AREAS DRY. TEMPS WED WILL BE
SEASONABLE...U40S/L50S PLAINS.
THU INTO EARLY FRI...
FIRST PACIFIC SYSTEM MOVES ACROSS REGION. SKIES WILL CLOUD UP DURING
THE DAY THU WITH PRECIP INCREASING OVER THE MTNS DURING THE DAY.
SNOW WILL PICK UP IN INTENSITY LATE THU OVER THE CONTDVD AND
COULD BE LOCALLY HEAVY AT TIMES THU NITE BEFORE DECREASING EARLY
FRIDAY. SOME PRECIP WILL BE POSSIBLE OVER THE PLAINS...WITH THE
BEST CHANCE OVER EL PASO AND THE FAR EASTERN PLAINS...ESPECIALLY
KIOWA COUNTY. TEMPS COULD BE TRICKY THURSDAY AS A BOUNDARY WILL
LIKELY LIE ACROSS THE PLAINS EXTENDING FROM ROUGHLY KIM TO
PUEBLO...AREAS E OF THIS LINE COULD SEE A CLOUDY COOL DAY WHILE
AREAS WEST OF THIS LINE MAY BE QUITE WARM...WINDY AND DRY...WITH FIRE
WX CONCERNS POSSIBLE ESPECIALLY DOWN ON THE RATON MESA.
LATE FRIDAY INTO EARLY SUNDAY...
A MORE SIGNIFICANT PACIFIC SYSTEM WILL MOVE ACROSS THE REGION. THIS
SYSTEM HAS THE POTENTIAL TO BRING HEAVY SNOWS TO THE CONTDVD
REGION...AND LATEST MODEL RUNS ARE STARTING TO SHOW MORE SIGNIF
QPF. HPC SHOWING 1-3" LIQUID OVER THE MTNS DURING THIS TIME. A
BETTER CHANCE OF PRECIP WILL OCCUR ON THE PLAINS SATURDAY/SAT NITE
AS MUCH COLDER AIR WILL BE MOVING INTO THE REGION AS THE PACIFIC
STORM MOVES ACROSS. THIS COMBO OF COLDER UPSLOPE AND FORCING ALOFT
SHOULD ALLOW FOR SOME SNOW ON THE PLAINS. BEST CHANCE WILL BE
NORTH OF HIWAY 50. I DO ANTICIPATE TRAVEL INTO THE MTNS THIS
WEEKEND WILL BE A BIT TEDIOUS...BUT THERE IS NOT MUCH WIND WITH
THIS SYSTEM SO BLOWING SNOW WILL BE LESS OF A CONCERN.
IT SHOULD BE NOTED THAT THE GFS IS MORE INTENSE WITH THIS SYSTEM
THEN THE LESS AMPLIFIED EC MODEL...HOWEVER BOTH MODELS HAVE GOOD QPF
FOR THE MTNS.
LOOKING A BIT BEYOND...GFS SHOWS ANOTHER SHARP TROUGH COMING ACROSS
LATE MONDAY INTO EARLY TUESDAY WHILE EC SHOWS A MUCH WEAKER SYSTEM.
LONG RANGE DISCUSSIONS WERE LEANING MORE TOWARDS THE EC GUIDANCE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1023 PM MST MON FEB 24 2014
STRATUS EVIDENT IN FOG PRODUCTS WILL BE SPREADING WESTWARD INTO
THE KCOS AND KPUB TERMINALS BETWEEN 06Z AND 07Z. CIGS WILL LIKELY
DROP INTO THE IFR CATEGORY BY 08Z...AND COULD EVEN HIT LIFR
CATEGORY TOWARDS 12Z. FORECAST WILL BE CHALLENGING TOMORROW WITH
REGARD TO TIMING OF THE CLEARING OF THE STRATUS. MODELS HINT AT
CIGS BREAKING BY 16Z...BUT WITH SOUTHEAST FLOW CONTINUING OPTED TO
HOLD ON TO IFR CIGS UNTIL 18Z. TIMING WILL LIKELY NEED TO BE
FINE TUNED FURTHER AS HIGH RES MODELS CONTINUE TO RESOLVE THE
SITUATION. ANOTHER COLD FRONT WILL BLAST SOUTHWARD ACROSS THE KCOS
TERMINAL AROUND 22Z AND THROUGH KPUB BY 23Z. NORTH WIND GUSTS TO
40 TO 45 KTS WILL BE POSSIBLE WITH FRONTAL PASSAGE. CIGS SHOULD
QUICKLY LOWER INTO THE MVFR CATEGORY WITH -SN POSSIBLE AT KCOS BY
00Z. ONLY LIGHT ACCUMULATIONS EXPECTED OVERNIGHT AT KCOS AND KPUB
TERMINALS...WITH AMOUNTS RANGING FROM A DUSTING TO 1/2 INCH.
KALS WILL REMAIN VFR WITH WINDS GENERALLY UNDER 10 KTS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KT
SHORT TERM...MOZLEY
LONG TERM...HODANISH
AVIATION...KT
AREA FORECAST DISCUSSION
NWS ALBANY NY
1234 AM EST TUE FEB 25 2014
.SYNOPSIS...
AN ARCTIC AIR MASS WILL BE IN PLACE THIS WEEK WITH BELOW NORMAL
TEMPERATURES. A SERIES OF DISTURBANCES ASSOCIATED WITH AN UPPER
LEVEL LOW WILL PRODUCE SCATTERED SNOW SHOWERS AND FLURRIES INTO THE
MID WEEK. A CLIPPER LOW ON WEDNESDAY WILL PRODUCE MORE WIDESPREAD
SNOW SHOWERS...AS IT PASSES ACROSS THE SOUTHERN QUEBEC AND NORTHERN
NEW YORK BORDER...WITH A REINFORCING SHOT OF ARCTIC AIR.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF MIDNIGHT EST...LAKE EFFECT SNOW SHOWERS HAVE BEEN SLOWLY
ORGANIZING SOMEWHAT BETTER OVER THE PAST FEW HOURS OVER PORTIONS
OF OSWEGO/ONEIDA COUNTIES...BUT STILL ARE MAINLY FRAGMENTED BANDS
FARTHER EAST ACROSS THE MOHAWK VALLEY INTO THE GREATER CAPITAL DISTRICT.
TRENDS IN THE HRRR AND HIRES WRF INDICATE THESE FRAGMENTED BANDS
WILL DRIFT SOUTH INTO SOUTHERN HERKIMER COUNTY...WHERE A LAKE
EFFECT SNOW ADVISORY REMAINS IN EFFECT. HOWEVER...THE LATEST MODEL
REFLECTIVITY TRENDS SHOW BANDS WEAKENING CONSIDERABLY AFTER 1 AM.
WILL LEAVE UP ADVISORY FOR NOW...BUT WILL MONITOR TRENDS FOR
POSSIBLE CANCELLATION BEFORE 6 AM.
INVERSION HEIGHTS ARE MARGINAL UPSTREAM AT KSYR/KRME/KUCA AT 6-7
KFT AGL WITH A 280-290 DEG LOW-LEVEL TRAJ. THE INSTABILITY CLASS
IS CONDITIONAL TO MODERATE WITH NARROW FRAGMENTED LAKE BANDS
EXTENDING DOWNSTREAM INTO THE WESTERN MOHAWK VALLEY. WILL
CONTINUE TO MENTION SLIGHT TO LOW CHC POPS MAINLY WEST OF THE
HUDSON RIVER VALLEY...EXCEPT HIGH CHANCE TO LIKELY POPS FOR THE
WESTERN MOHAWK VALLEY AND A PORTION OF THE SOUTHWEST ADIRONDACKS
WHERE LAKE EFFECT ACTIVITY WILL BE MORE PRONOUNCED.
H850 TEMPS WILL BE IN THE -17C TO -20C RANGE WITH THE COLD
ADVECTION IN THE WAKE OF THE SFC TROUGH. EXPECT LOWS TO BE IN THE
UPPER SINGLE DIGITS AND TEENS FROM THE CAPITAL DISTRICT SOUTH AND
EAST...WITH SINGLE DIGITS TO A FEW BELOW ZERO READINGS /SRN DACKS/ OVER
THE NRN TIER. BRISK W/NW WINDS WILL GENERATE WIND CHILLS 10 TO 15
BELOW ZERO OVER THE SRN DACKS...AND GENERALLY 5 BELOW TO 5 ABOVE
IN MOST OTHER LOCATIONS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
TUESDAY...ANY ORGANIZED LAKE EFFECT ACTIVITY DIMINISHES DUE TO THE
LOWERING INVERSION. HOWEVER...LAKE MOISTURE WILL STILL BE
UTILIZED...AS A WEAK MID LEVEL DISTURBANCE MAY FOCUS ISOLATED TO
SCATTERED SNOW SHOWERS AGAIN DURING DURING THE MORNING INTO THE
AFTERNOON...WITH THE BETTER CHANCE OF SNOWFALL IN THE AFTERNOON
ALONG THE WRN SPINE OF THE WRN DACKS...SRN GREENS...NRN-CNTRL
TACONICS AND BERKSHIRES. THE WESTERLY UPSLOPE SNOW SHOWERS AND
FLURRIES MAY PRODUCE LIGHT SNOW AMOUNTS OF A COATING TO AN INCH OR
TWO. H850 TEMPS WILL BE RUNNING 1 TO 2 STANDARD DEVIATIONS BELOW
NORMAL ACCORDING TO THE LATEST GEFS. TEMPS WILL STILL RUN ABOUT 10
DEGREES OR SO BELOW NORMAL. OUR FORECAST FAVORS THE COLD NAM MOS
MAX TEMPS WITH TEENS OVER THE SRN DACKS. LOWER TO M20S OVER THE
REST OF THE FCST AREA...EXCEPT U20S OVER THE MID HUDSON
VALLEY...SRN TACONICS...AND NW CT.
TUE NIGHT...A CLIPPER LOW APPROACHES FROM THE NRN GREAT LAKES
REGION...AND SE ONTARIO. THIS CLIPPER WILL TAP SOME LAKE EFFECT
MOISTURE...AS THE FLOW BACKS TO SOUTHWEST. THERE IS SOME SYNOPTIC
LIFT WITH THIS SYSTEM. OROGRAPHIC AND LOW-LEVEL CONVERGENCE MAY
PROMOTE A PERIOD OF LIGHT SNOW ESPECIALLY NORTH AND WEST OF THE
CAPITAL REGION. A BURST OF LAKE EFFECT OR LAKE ENHANCED SNOWFALL
MAY OCCUR OVER THE WRN DACKS/WRN MOHAWK VALLEY AROUND MIDNIGHT AND
THEREAFTER. 1-4 INCHES OF SNOWFALL MAY BE POSSIBLE...ESPECIALLY
OVER THE WRN DACKS BY WED MORNING. WITH THE WEAK THERMAL
ADVECTION...SLIGHT OR LOW CHANCES OF SNOW SHOWERS SPREAD EASTWARD
ACROSS THE FCST AREA AFTER MIDNIGHT. LOWS WILL RANGE FROM THE
SINGLE DIGITS OVER THE NW PORTION OF THE FCST AREA TO TEENS FROM
THE MOHAWK VALLEY/CAPITAL REGION SOUTH AND EAST.
WED-WED NIGHT...THE CLIPPER MOVES N/NE OF NRN NY OVER SRN QUEBEC
BY NOON. ANOTHER LOW PRESSURE SYSTEM FORMS WELL OFF THE MID
ATLANTIC COAST. A PERIOD OF SNOW SHOWERS OR LIGHT SNOW WILL IMPACT
THE REGION DURING THE MORNING INTO THE EARLY PM AHEAD OF THE
ARCTIC FRONT. CHC POPS WERE USED FOR THE ENTIRE AREA. SNOW ACCUMS
OF A COATING TO AN INCH WILL BE POSSIBLE. ARCTIC AIR POURS BACK
INTO THE REGION WITH H850 TEMPS FALLING TO -19C TO -23C OVER THE
FCST AREA...AND THE GEFS INDICATE THESE VALUES WILL BE 2 TO 3
STANDARD DEVIATIONS BELOW NORMAL. THE STRONG COLD ADVECTION SWEEPS
THROUGH BEFORE NIGHTFALL. AFTER HIGHS IN THE TEENS AND 20S WITH
BLUSTERY CONDITIONS...LOWS WILL BE ZERO TO 5 BELOW OVER THE SRN
DACKS AND PARTS OF THE LAKE GEORGE REGION....AND SINGLE DIGITS
ELSEWHERE. UPSLOPE AND LAKE EFFECT SNOW SHOWERS WILL CONTINUE IN
THE AFTERNOON...AND THEN TAPER SNOW SHOWERS NORTH AND WEST OF THE
TRI CITIES WITH ANOTHER DISTURBANCE APPROACHING FROM THE UPPER
GREAT LAKES REGION. WIND CHILLS VALUES MAY NOT HIT ADVISORY LEVELS
WED NIGHT DUE TO A WEAKENING WIND FIELD...BUT MAY HIT ADVISORY
LEVELS OVER SOME OF THE MTN ZONES THU NIGHT/FRI MORNING.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
A SERIES OF EMBEDDED SHORTWAVES WILL MOVE ABOUT THE BASE OF A LARGE
UPPER LEVEL TROUGH THAT WILL PROVIDE CHANCES OF SOME PRECIPITATION
THROUGHOUT THE EXTENDED PERIOD. THE UPPER LEVEL FLOW PATTERN WILL
BEGIN TO SLOWLY TRANSITION INTO A ZONAL PATTERN WITH COLD AIR STILL
IN PLACE AS WE GO THE THE END OF THE EXTENDED PERIOD.
THURSDAY INTO FRIDAY...COLD NORTHWESTERLY FLOW WITH BELOW AVERAGE
TEMPERATURES WITH T850 BETWEEN -20C TO -24C AND T925 TEMPS BETWEEN
-16C AND -20C WILL BE LOCKED INTO THE REGION. A NEGATIVE TILTED
SHORTWAVE TROUGH WITHIN THE UPPER LEVEL FLOW WITH THE AXIS OVER THE
NY/CANADA BORDER WILL PROVIDE THE CHANCE OF SNOW SHOWERS ESPECIALLY
AREAS NORTH AND WEST OF THE IMMEDIATE CAPITAL REGION NEAR THE UPPER
LEVEL TROUGH AS WE GO THURSDAY NIGHT INTO FRIDAY MORNING. A STEEP
GRADIENT IN ISOBARS WILL ALSO PRODUCE GUSTY NORTHWEST WINDS
WITH GUSTS NEAR 30 MPH POSSIBLE ESPECIALLY IN THE HIGHEST TERRAIN.
TEMPERATURES ON THURSDAY WILL RANGE FROM THE LOWER 20S TO UPPER 20S
WHICH WILL FALL TO LOWER TEENS IN THE HIGH TERRAIN TO NEAR 20 IN
VALLEY LOCATIONS ON FRIDAY. LOW TEMPERATURES ON THURSDAY WILL BE
VERY COLD WITH VALUES RANGING FROM 10 BELOW TO NEAR ZERO IN THE HIGH
TERRAIN TO AROUND ZERO TO 5 ABOVE FOR THE VALLEY AREAS.
FRIDAY NIGHT THROUGH MONDAY...COLD AIR FROM CANADA WITH
NORTHWESTERLY WINDS WILL CONTINUE WITH SERIES OF UPPER LEVEL TROUGHS
CONTINUING TO MOVE WEST TO EAST ACROSS OUR AREA WITH AREAS OF WEAK
HIGH PRESSURE IN BETWEEN THE PASSING DISTURBANCES AS THE UPPER LEVEL
WAVE OSCILLATES AROUND THE LARGE UPPER LEVEL LOW IN NORTHERN QUEBEC.
THE NEXT CHANCE OF SNOW SHOWERS ACCORDING TO THE LATEST 12Z MODELS
AND NUMERICAL GUIDANCE WILL BE DURING THE DAY ON SATURDAY AS ANOTHER
WAVE OF LOW PRESSURE MOVES RIGHT OVER OUR REGION ACCORDING TO THE
LATEST TRENDS. CHANCE OF SNOW SHOWERS WILL BE IN THE FORECAST AT
THIS TIME AS THE TRACK AND INTENSITY AGREEMENT BETWEEN THE MODELS
SHOW LOW CONFIDENCE AT THIS TIME. A SURFACE HIGH PRESSURE WILL WORK
INTO THE AREA ON SUNDAY GIVING TRANQUIL WEATHER CONDITIONS. AS WE GO
INTO MONDAY...THE MODELS DO DIFFER IN OUR NEXT WEATHER SYSTEM WITH
ITS TRACK AND INTENSITY. THIS WILL HAVE TO BE MONITORED WITH FUTURE
UPDATES TO THE FORECAST. HIGH TEMPERATURES FROM SATURDAY INTO MONDAY
WILL REMAIN BELOW AVERAGE WITH TEMPERATURES RANGING FROM THE MID
TEENS TO MID 20S. LOW TEMPERATURES WILL ALSO BE VERY COLD FOR THIS
TIME OF YEAR WITH TEMPERATURE 10 BELOW ZERO TO NEAR ZERO FOR THE
LAKE GEORGE SARATOGA REGION POINTS NORTH AND WEST AND ALSO IN THE
HIGH TERRAIN OF NEW ENGLAND AND WITH LOW TEMPERATURES OF 0 TO 5 IN
THE IMMEDIATE CAPITAL REGION AND VALLEY LOCATIONS.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AN UPPER LEVEL DISTURBANCE WILL PASS SOUTH OF THE REGION LATER THIS
MORNING INTO EARLY AFTERNOON.
MAINLY VFR CONDITIONS WITH CIGS AROUND 3500-5000 FEET ARE
EXPECTED AT THE TERMINALS THROUGH THE 24 HOUR PERIOD ENDING 06Z
WEDNESDAY. HOWEVER...THE COMBINATION OF SOME LAKE EFFECT
MOISTURE...AND ALSO THE AFOREMENTIONED UPPER LEVEL IMPULSE PASSING
SOUTH OF THE REGION...SHOULD ALLOW FOR AT LEAST SOME
ISOLATED/SCATTERED SNOW SHOWERS TO OCCUR THROUGH MUCH OF TUESDAY.
IN THE NEAR TERM...THE BAND OF SNOW SHOWERS CURRENTLY ACROSS THE
MOHAWK VALLEY REGION IS EXPECTED TO CONTINUE SHIFTING SLOWLY
SOUTH...AND WEAKEN. HOWEVER...A FEW FILAMENTS OF SNOW SHOWERS MAY
STILL REACH KALB AND KPSF THROUGH 08Z/TUE. THIS COULD LEAD TO BRIEF
REDUCTIONS IN VSBY INTO THE MVFR/IFR RANGE.
THEN...AFTER DAYBREAK...SNOW SHOWERS SHOULD INCREASE IN AREAL
COVERAGE ONCE AGAIN...PEAKING LATER THIS MORNING INTO THE MID
AFTERNOON. AGAIN...OVERALL COVERAGE SHOULD BE SCATTERED...BUT SHOULD
ANY IMPACT THE TAF SITES...VSBYS COULD DROP INTO THE IFR RANGE. THE
SNOW SHOWERS SHOULD DECREASE IN AREAL COVERAGE AFTER 20Z/TUE AS THE
DISTURBANCE STARTS TO MOVE AWAY FROM THE REGION...AND LAKE EFFECT
ACTIVITY DECREASES.
WEST-NORTHWEST WINDS WILL DECREASE SLIGHTLY TO AROUND 8-12 KT
THROUGH DAYBREAK...ALTHOUGH MAY STILL OCCASIONALLY GUST UP TO 15-20
KT...ESP AT KALB AND KPSF. WIND SPEEDS WILL INCREASE AGAIN BY MID
MORNING TUESDAY TO 10-15 KT WITH SOME GUSTS OF AROUND 25
KT...STRONGEST AT KALB AND KPSF DUE TO FUNNELING EFFECT DOWN THE
MOHAWK RIVER VALLEY.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. WINDY. CHANCE OF SHSN.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF SHSN.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
&&
.HYDROLOGY...
AN ARCTIC AIR MASS WILL REMAIN ACROSS THE HYDRO SERVICE AREA FOR
THE ENTIRE WEEK WHICH WILL ALLOW ICE TO REFORM...THICKEN...AND
STRENGTHEN ON AREA RIVERS AND LAKES THROUGH THE WEEK. LIGHT
PRECIPITATION IS EXPECTED DURING THE WEEK...AND ANY THAT DOES
OCCUR WILL BE IN THE FORM OF SNOW SHOWERS OR LIGHT SNOW. NO HYDRO
IMPACTS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5 DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST EARLY THIS MORNING
FOR NYZ038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...11/JPV/WASULA
SHORT TERM...WASULA
LONG TERM...LFM
AVIATION...KL/JPV
HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1213 AM EST TUE FEB 25 2014
.SYNOPSIS...
AN ARCTIC AIR MASS WILL BE IN PLACE THIS WEEK WITH BELOW NORMAL
TEMPERATURES. A SERIES OF DISTURBANCES ASSOCIATED WITH AN UPPER
LEVEL LOW WILL PRODUCE SCATTERED SNOW SHOWERS AND FLURRIES INTO THE
MID WEEK. A CLIPPER LOW ON WEDNESDAY WILL PRODUCE MORE WIDESPREAD
SNOW SHOWERS...AS IT PASSES ACROSS THE SOUTHERN QUEBEC AND NORTHERN
NEW YORK BORDER...WITH A REINFORCING SHOT OF ARCTIC AIR.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF MIDNIGHT EST...LAKE EFFECT SNOW SHOWERS HAVE BEEN SLOWLY
ORGANIZING SOMEWHAT BETTER OVER THE PAST FEW HOURS OVER PORTIONS
OF OSWEGO/ONEIDA COUNTIES...BUT STILL ARE MAINLY FRAGMENTED BANDS
FARTHER EAST ACROSS THE MOHAWK VALLEY INTO THE GREATER CAPITAL DISTRICT.
TRENDS IN THE HRRR AND HIRES WRF INDICATE THESE FRAGMENTED BANDS
WILL DRIFT SOUTH INTO SOUTHERN HERKIMER COUNTY...WHERE A LAKE
EFFECT SNOW ADVISORY REMAINS IN EFFECT. HOWEVER...THE LATEST MODEL
REFLECTIVITY TRENDS SHOW BANDS WEAKENING CONSIDERABLY AFTER 1 AM.
WILL LEAVE UP ADVISORY FOR NOW...BUT WILL MONITOR TRENDS FOR
POSSIBLE CANCELLATION BEFORE 6 AM.
INVERSION HEIGHTS ARE MARGINAL UPSTREAM AT KSYR/KRME/KUCA AT 6-7
KFT AGL WITH A 280-290 DEG LOW-LEVEL TRAJ. THE INSTABILITY CLASS
IS CONDITIONAL TO MODERATE WITH NARROW FRAGMENTED LAKE BANDS
EXTENDING DOWNSTREAM INTO THE WESTERN MOHAWK VALLEY. WILL
CONTINUE TO MENTION SLIGHT TO LOW CHC POPS MAINLY WEST OF THE
HUDSON RIVER VALLEY...EXCEPT HIGH CHANCE TO LIKELY POPS FOR THE
WESTERN MOHAWK VALLEY AND A PORTION OF THE SOUTHWEST ADIRONDACKS
WHERE LAKE EFFECT ACTIVITY WILL BE MORE PRONOUNCED.
H850 TEMPS WILL BE IN THE -17C TO -20C RANGE WITH THE COLD
ADVECTION IN THE WAKE OF THE SFC TROUGH. EXPECT LOWS TO BE IN THE
UPPER SINGLE DIGITS AND TEENS FROM THE CAPITAL DISTRICT SOUTH AND
EAST...WITH SINGLE DIGITS TO A FEW BELOW ZERO READINGS /SRN DACKS/ OVER
THE NRN TIER. BRISK W/NW WINDS WILL GENERATE WIND CHILLS 10 TO 15
BELOW ZERO OVER THE SRN DACKS...AND GENERALLY 5 BELOW TO 5 ABOVE
IN MOST OTHER LOCATIONS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
TUESDAY...ANY ORGANIZED LAKE EFFECT ACTIVITY DIMINISHES DUE TO THE
LOWERING INVERSION. HOWEVER...LAKE MOISTURE WILL STILL BE
UTILIZED...AS A WEAK MID LEVEL DISTURBANCE MAY FOCUS ISOLATED TO
SCATTERED SNOW SHOWERS AGAIN DURING DURING THE MORNING INTO THE
AFTERNOON...WITH THE BETTER CHANCE OF SNOWFALL IN THE AFTERNOON
ALONG THE WRN SPINE OF THE WRN DACKS...SRN GREENS...NRN-CNTRL
TACONICS AND BERKSHIRES. THE WESTERLY UPSLOPE SNOW SHOWERS AND
FLURRIES MAY PRODUCE LIGHT SNOW AMOUNTS OF A COATING TO AN INCH OR
TWO. H850 TEMPS WILL BE RUNNING 1 TO 2 STANDARD DEVIATIONS BELOW
NORMAL ACCORDING TO THE LATEST GEFS. TEMPS WILL STILL RUN ABOUT 10
DEGREES OR SO BELOW NORMAL. OUR FORECAST FAVORS THE COLD NAM MOS
MAX TEMPS WITH TEENS OVER THE SRN DACKS. LOWER TO M20S OVER THE
REST OF THE FCST AREA...EXCEPT U20S OVER THE MID HUDSON
VALLEY...SRN TACONICS...AND NW CT.
TUE NIGHT...A CLIPPER LOW APPROACHES FROM THE NRN GREAT LAKES
REGION...AND SE ONTARIO. THIS CLIPPER WILL TAP SOME LAKE EFFECT
MOISTURE...AS THE FLOW BACKS TO SOUTHWEST. THERE IS SOME SYNOPTIC
LIFT WITH THIS SYSTEM. OROGRAPHIC AND LOW-LEVEL CONVERGENCE MAY
PROMOTE A PERIOD OF LIGHT SNOW ESPECIALLY NORTH AND WEST OF THE
CAPITAL REGION. A BURST OF LAKE EFFECT OR LAKE ENHANCED SNOWFALL
MAY OCCUR OVER THE WRN DACKS/WRN MOHAWK VALLEY AROUND MIDNIGHT AND
THEREAFTER. 1-4 INCHES OF SNOWFALL MAY BE POSSIBLE...ESPECIALLY
OVER THE WRN DACKS BY WED MORNING. WITH THE WEAK THERMAL
ADVECTION...SLIGHT OR LOW CHANCES OF SNOW SHOWERS SPREAD EASTWARD
ACROSS THE FCST AREA AFTER MIDNIGHT. LOWS WILL RANGE FROM THE
SINGLE DIGITS OVER THE NW PORTION OF THE FCST AREA TO TEENS FROM
THE MOHAWK VALLEY/CAPITAL REGION SOUTH AND EAST.
WED-WED NIGHT...THE CLIPPER MOVES N/NE OF NRN NY OVER SRN QUEBEC
BY NOON. ANOTHER LOW PRESSURE SYSTEM FORMS WELL OFF THE MID
ATLANTIC COAST. A PERIOD OF SNOW SHOWERS OR LIGHT SNOW WILL IMPACT
THE REGION DURING THE MORNING INTO THE EARLY PM AHEAD OF THE
ARCTIC FRONT. CHC POPS WERE USED FOR THE ENTIRE AREA. SNOW ACCUMS
OF A COATING TO AN INCH WILL BE POSSIBLE. ARCTIC AIR POURS BACK
INTO THE REGION WITH H850 TEMPS FALLING TO -19C TO -23C OVER THE
FCST AREA...AND THE GEFS INDICATE THESE VALUES WILL BE 2 TO 3
STANDARD DEVIATIONS BELOW NORMAL. THE STRONG COLD ADVECTION SWEEPS
THROUGH BEFORE NIGHTFALL. AFTER HIGHS IN THE TEENS AND 20S WITH
BLUSTERY CONDITIONS...LOWS WILL BE ZERO TO 5 BELOW OVER THE SRN
DACKS AND PARTS OF THE LAKE GEORGE REGION....AND SINGLE DIGITS
ELSEWHERE. UPSLOPE AND LAKE EFFECT SNOW SHOWERS WILL CONTINUE IN
THE AFTERNOON...AND THEN TAPER SNOW SHOWERS NORTH AND WEST OF THE
TRI CITIES WITH ANOTHER DISTURBANCE APPROACHING FROM THE UPPER
GREAT LAKES REGION. WIND CHILLS VALUES MAY NOT HIT ADVISORY LEVELS
WED NIGHT DUE TO A WEAKENING WIND FIELD...BUT MAY HIT ADVISORY
LEVELS OVER SOME OF THE MTN ZONES THU NIGHT/FRI MORNING.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
A SERIES OF EMBEDDED SHORTWAVES WILL MOVE ABOUT THE BASE OF A LARGE
UPPER LEVEL TROUGH THAT WILL PROVIDE CHANCES OF SOME PRECIPITATION
THROUGHOUT THE EXTENDED PERIOD. THE UPPER LEVEL FLOW PATTERN WILL
BEGIN TO SLOWLY TRANSITION INTO A ZONAL PATTERN WITH COLD AIR STILL
IN PLACE AS WE GO THE THE END OF THE EXTENDED PERIOD.
THURSDAY INTO FRIDAY...COLD NORTHWESTERLY FLOW WITH BELOW AVERAGE
TEMPERATURES WITH T850 BETWEEN -20C TO -24C AND T925 TEMPS BETWEEN
-16C AND -20C WILL BE LOCKED INTO THE REGION. A NEGATIVE TILTED
SHORTWAVE TROUGH WITHIN THE UPPER LEVEL FLOW WITH THE AXIS OVER THE
NY/CANADA BORDER WILL PROVIDE THE CHANCE OF SNOW SHOWERS ESPECIALLY
AREAS NORTH AND WEST OF THE IMMEDIATE CAPITAL REGION NEAR THE UPPER
LEVEL TROUGH AS WE GO THURSDAY NIGHT INTO FRIDAY MORNING. A STEEP
GRADIENT IN ISOBARS WILL ALSO PRODUCE GUSTY NORTHWEST WINDS
WITH GUSTS NEAR 30 MPH POSSIBLE ESPECIALLY IN THE HIGHEST TERRAIN.
TEMPERATURES ON THURSDAY WILL RANGE FROM THE LOWER 20S TO UPPER 20S
WHICH WILL FALL TO LOWER TEENS IN THE HIGH TERRAIN TO NEAR 20 IN
VALLEY LOCATIONS ON FRIDAY. LOW TEMPERATURES ON THURSDAY WILL BE
VERY COLD WITH VALUES RANGING FROM 10 BELOW TO NEAR ZERO IN THE HIGH
TERRAIN TO AROUND ZERO TO 5 ABOVE FOR THE VALLEY AREAS.
FRIDAY NIGHT THROUGH MONDAY...COLD AIR FROM CANADA WITH
NORTHWESTERLY WINDS WILL CONTINUE WITH SERIES OF UPPER LEVEL TROUGHS
CONTINUING TO MOVE WEST TO EAST ACROSS OUR AREA WITH AREAS OF WEAK
HIGH PRESSURE IN BETWEEN THE PASSING DISTURBANCES AS THE UPPER LEVEL
WAVE OSCILLATES AROUND THE LARGE UPPER LEVEL LOW IN NORTHERN QUEBEC.
THE NEXT CHANCE OF SNOW SHOWERS ACCORDING TO THE LATEST 12Z MODELS
AND NUMERICAL GUIDANCE WILL BE DURING THE DAY ON SATURDAY AS ANOTHER
WAVE OF LOW PRESSURE MOVES RIGHT OVER OUR REGION ACCORDING TO THE
LATEST TRENDS. CHANCE OF SNOW SHOWERS WILL BE IN THE FORECAST AT
THIS TIME AS THE TRACK AND INTENSITY AGREEMENT BETWEEN THE MODELS
SHOW LOW CONFIDENCE AT THIS TIME. A SURFACE HIGH PRESSURE WILL WORK
INTO THE AREA ON SUNDAY GIVING TRANQUIL WEATHER CONDITIONS. AS WE GO
INTO MONDAY...THE MODELS DO DIFFER IN OUR NEXT WEATHER SYSTEM WITH
ITS TRACK AND INTENSITY. THIS WILL HAVE TO BE MONITORED WITH FUTURE
UPDATES TO THE FORECAST. HIGH TEMPERATURES FROM SATURDAY INTO MONDAY
WILL REMAIN BELOW AVERAGE WITH TEMPERATURES RANGING FROM THE MID
TEENS TO MID 20S. LOW TEMPERATURES WILL ALSO BE VERY COLD FOR THIS
TIME OF YEAR WITH TEMPERATURE 10 BELOW ZERO TO NEAR ZERO FOR THE
LAKE GEORGE SARATOGA REGION POINTS NORTH AND WEST AND ALSO IN THE
HIGH TERRAIN OF NEW ENGLAND AND WITH LOW TEMPERATURES OF 0 TO 5 IN
THE IMMEDIATE CAPITAL REGION AND VALLEY LOCATIONS.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
MAINLY VFR CONDITIONS WITH CIGS AROUND 3500-5000 FEET ARE
EXPECTED AT THE TERMINALS THROUGH THE 24 HOUR PERIOD ENDING 00Z
WEDNESDAY. THE ONLY EXCEPTION WILL BE A LOW PROBABILITY FOR A
PASSING SNOW SHOWER OR TWO. SNOW SHOWERS HAVE BEEN DIMINISHING IN
COVERAGE THIS EVENING WITH LOSS OF DAYTIME HEATING.
HOWEVER...THERE IS STILL A CHANCE FOR A FEW LAKE ENHANCED SNOW
SHOWERS TONIGHT INTO EARLY TUESDAY MORNING. WILL MENTION VCSH AT
THE ALB/KPSF/KGFL TERMINALS TO ACCOUNT FOR THIS CHANCE. ANY SNOW
SHOWER COULD BRIEFLY RESULT IN MVFR/IFR CONDITIONS...BUT
PROBABILITY OF OCCURRENCE IS TOO LOW TO MENTION EXPLICITLY IN
TAFS.
WEST-NORTHWEST WINDS WILL INITIALLY BE AROUND 10-15 KT WITH GUSTS
TO 25 KT ESPECIALLY AT KALB/KPSF...WITH WIND SPEEDS DECREASING TO
AROUND 5-10 KT AFTER MIDNIGHT. WIND SPEEDS WILL INCREASE AGAIN BY
MID MORNING TUESDAY TO AROUND 10-15 KT WITH SOME GUSTS NEAR 20 KT.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. WINDY. CHANCE OF SHSN.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF SHSN.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
&&
.HYDROLOGY...
AN ARCTIC AIR MASS WILL REMAIN ACROSS THE HYDRO SERVICE AREA FOR
THE ENTIRE WEEK WHICH WILL ALLOW ICE TO REFORM...THICKEN...AND
STRENGTHEN ON AREA RIVERS AND LAKES THROUGH THE WEEK. LIGHT
PRECIPITATION IS EXPECTED DURING THE WEEK...AND ANY THAT DOES
OCCUR WILL BE IN THE FORM OF SNOW SHOWERS OR LIGHT SNOW. NO HYDRO
IMPACTS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5 DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST EARLY THIS MORNING
FOR NYZ038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...11/JPV/WASULA
SHORT TERM...WASULA
LONG TERM...LFM
AVIATION...JPV
HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS MIAMI FL
1245 AM EST TUE FEB 25 2014
.AVIATION...
VFR CONDITIONS SHOULD PERSIST THROUGH THE BULK OF THE TAF PERIOD
WITH LIGHT WINDS. ALTHOUGH FOG IS CERTAINLY NOT OUT OF QUESTION
FOR TMB AND APF BY DAYBREAK TODAY...THE LATEST IR SATELLITE
IMAGERY CONTINUES TO SHOW PLENTY OF UPPER-LEVEL CLOUDS STREAMING
WEST TO EAST OVER THE AREA THAT WILL REDUCE THESE CHANCES. LATER
TODAY...THE BEST SHRA/TSTM CHANCES WILL REMAIN ALONG THE EAST
COAST SITES THROUGH THE AFTERNOON AND EARLY EVENING HOURS.
&&
.PREV DISCUSSION... /ISSUED 858 PM EST MON FEB 24 2014/
UPDATE...
MAINLY TRANQUIL CONDITIONS PREVAIL ACROSS THE REGION THIS EVENING.
BY THE EARLY MORNING HOURS PATCHY FOG IS EXPECTED ACROSS THE
REGION AGAIN...MAINLY ACROSS THE INTERIOR REGIONS AND WEST.
NO SIGNIFICANT CHANGES WERE REQUIRED TO THE FORECAST.
60
PREV DISCUSSION... /ISSUED 628 PM EST MON FEB 24 2014/
AVIATION...
CONDITIONS SHOULD BE MOSTLY QUIET TONIGHT, WITH THE EXCEPTION OF A
STRAY, LIGHT SHOWER THAT COULD DEVELOP. OTHERWISE, VFR CONDITIONS
FOR THE EASTERN TAF SITES. THE EXCEPTION MAY BE KTMB, WHERE SOME
SOME FOG COULD DEVELOP. HOWEVER, THE IS TOO MUCH UNCERTAINTY TO
PUT A MENTION IN THE TAF AT THIS TIME. ALSO, KAPF MAY SEE SOME
FOG. THERE IS A BETTER CHANCE FOR NAPLES, THUS A MENTION OF LIGHT
FOG IN THE TAF FOR TONIGHT. TOMORROW WILL SEE A CHANCE OF SHOWERS
AND MAYBE A THUNDERSTORM FOR THE EASTERN HALF OF SOUTH FLORIDA.
FOR NOW, JUST A VCSH TO REFLECT THIS. WINDS WILL GO LIGHT AND
VARIABLE TONIGHT. THEY MAY BE DELAYED IN PICKING UP OUT OF THE
WEST TO SOUTHWEST TOMORROW BETWEEN 5 AND 10 KTS. KFLL MAYBE THE
EXCEPTION WHERE A WEAK SEA BREEZE MAY BRING THE WINDS TO A MORE
SOUTH SOUTH EASTERLY DIRECTION BY LATE MORNING OR EARLY AFTERNOON.
PREV DISCUSSION... /ISSUED 246 PM EST MON FEB 24 2014/
DISCUSSION...
A WEAK COLD FRONT CURRENTLY DRAPED ACROSS NORTHERN FLORIDA IS
EXPECTED TO SLOWLY PUSH TO THE SOUTH THROUGH THE AFTERNOON AND
EVENING. AS IT DOES...A FEW SHOWERS AND POSSIBLY AN ISOLATED
THUNDERSTORM OR TWO MAY DEVELOP ACROSS MAINLY THE EAST COASTAL AREAS
ENHANCED BY A WEAK SEA BREEZE THAT MAY DEVELOP. LATEST HRRR WINDS
DEPICT A WEAK SEA BREEZE ALONG MAINLY THE BROWARD AND PALM BEACH
COUNTY COASTS.
MODELS DEPICT THE COLD FRONT AND ACCOMPANYING DEEPER MOISTURE FIELD
TO BECOME NEARLY STATIONARY ACROSS SOUTH FLORIDA THROUGH TUESDAY
WITH RAIN CHANCES REMAINING ALONG WITH LIGHT AND VARIABLE WINDS.
KEPT SLIGHT CHANCES FOR THUNDERSTORMS TUESDAY AFTERNOON ALONG THE
NORTHERN INTERIOR AND EAST COAST AS WELL WITH THE LINGERING BOUNDARY
IN THE AREA. BY TUESDAY NIGHT INTO EARLY WEDNESDAY...THE FRONT IS
EXPECTED TO BASICALLY WASH OUT IN PLACE. FLOW WILL THEN QUICKLY
BECOME SOUTHWEST AND INCREASE LATE WEDNESDAY OUT AHEAD OF ANOTHER
COLD FRONT POSITIONED ACROSS THE NORTHERN GULF OF MEXICO. THIS FRONT
LOOKS TO BE A BIT STRONGER THAN THE LAST ONE AND SHOULD PUSH THROUGH
SOUTH FLORIDA BY EARLY THURSDAY MORNING WITH BETTER CHANCES FOR
SHOWERS. DID NOT INCLUDE A THUNDER MENTION AT THIS TIME DUE TO THE
TIMING OF THE FRONT BEING DURING THE EARLY MORNING HOURS...ACCORDING
TO THE ECMWF. THE GFS SOLUTION IS A BIT SLOWER BRINGING THE FRONT
INTO SOUTH FLORIDA LATER IN THE AFTERNOON. IF THIS SOLUTION PANS
OUT...THE COMBINATION OF FRONTAL FORCING AND DAYTIME HEATING WOULD
YIELD THUNDERSTORM DEVELOPMENT. WILL NEED TO WATCH SUBSEQUENT MODEL
RUNS CLOSELY FOR TIMING CHANGES.
SHOWERS WILL LINGER THROUGH FRIDAY BEFORE DRY WEATHER RETURNS FOR
THE WEEKEND. UPPER RIDGING WILL THEN BUILD ACROSS THE AREA FROM THE
SOUTH KEEPING TEMPERATURES ABOVE NORMAL.
MARINE...
WINDS OF 10 KNOTS OR LESS ARE EXPECTED TO CONTINUE ACROSS THE
REGIONAL WATERS WITH SEAS OF 2 FEET OR LESS. A COLD FRONT IS
FORECAST TO AFFECT THE REGIONAL WATERS EARLY THURSDAY WITH AN
INCREASE IN WINDS AND SEAS EXPECTED. HOWEVER...HAZARDOUS SEAS ARE
NOT FORECAST FOR THIS PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 63 82 65 / 30 10 20 40
FORT LAUDERDALE 82 66 82 69 / 30 10 20 30
MIAMI 83 67 83 69 / 30 10 20 30
NAPLES 79 62 80 66 / 20 - 20 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...84/AK
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS GOODLAND KS
224 AM MST TUE FEB 25 2014
.UPDATE...
ISSUED AT 742 PM MST MON FEB 24 2014
JUST ISSUED AN UPDATE TO LOWER MINS WITH SOME LOCATIONS ALREADY
GETTING CLOSE TO THE FORECAST. COLD ADVECTION MORE AGGRESSIVE THAN WHAT
THE CURRENT MODEL OUTPUT IS SAYING. USING CURRENT READINGS AND THE
LATEST HRRR TO MAKE THE ADJUSTMENT.
UPDATE ISSUED AT 556 PM MST MON FEB 24 2014
JUST COMPLETED AN UPDATE. MAIN CHANGE WAS THE WINDS. COLD FRONT
GOING THROUGH THE AREA AT THIS TIME WITH STRONG 3 HOUR PRESSURE
RISES AND TIGHT GRADIENT BEHIND IT. SO WINDS WERE INCREASED INTO
THE BREEZY TO WINDY CATEGORY. BY MID EVENING THE WINDS SHOULD
DECREASE WITH LIGHTER WINDS AFTER MIDNIGHT. MINOR ADJUSTMENT WAS
ALSO MADE TO THE SKY COVER TO INCREASE IT A LITTLE FASTER THAN
WHAT THE GRIDS DEPICTED.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 215 PM MST MON FEB 24 2014
MAIN FOCUS FOR THE SHORT TERM TODAY IS THE TEMPERATURES AND
PRECIPITATION CHANCES OVERNIGHT AND TOMORROW. TEMPERATURES TODAY
HAVE RISEN INTO THE MID 30S OVER THE NORTHEAST PORTIONS OF THE CWA
WHILE FURTHER WEST TEMPERATURES HAVE RISEN INTO THE LOW 60S IN
FLAGLER COLORADO ASSOCIATED WITH A WARM FRONT IN EASTERN COLORADO. THE
NORTHEAST PORTION OF THE CWA WILL REMAIN ON THE COOL SIDE WITH
HIGHS IN THE LOW 20S WHILE THE WEST/SOUTHWEST PORTIONS OF THE CWA
COOL DOWN SIGNIFICANTLY FROM TODAY TO TOMORROW WITH HIGHS
STRUGGLING TO REACH 30 AS A BACK DOOR COLD FRONT MOVES THROUGH
OVERNIGHT. BEHIND THE COLD FRONT...CLOUD COVER WILL INCREASE AND
THERE WILL BE A CHANCE FOR SNOW FLURRIES MOVING IN FROM THE
NORTHEAST. FOR TEMPERATURES AND PRECIPITATION...WENT WITH A BLEND
OF NAM...SREF...AND HRRR. BUFKIT SOUNDINGS BECOME SATURATED
SLIGHTLY ABOVE THE SURFACE AND BECOME DRIER TOWARDS THE SURFACE.
SINCE THE TEMPERATURE PROFILE IS BELOW ZERO AND THE COLUMN IS
FAIRLY SATURATED...CHANGED PRECIPITATION TYPE TO FLURRIES FROM
FREEZING FOG...FROM THE PREVIOUS FORECAST...SINCE THIS SEEMS MORE
LIKELY. FLURRIES SHOULD TAPER OFF AROUND 12Z AS SURFACE HIGH
PRESSURE SLIDES INTO THE CWA.
THE PERIOD OF NO PRECIPITATION TOMORROW MORNING WILL BE RATHER
SHORT-LIVED AS THE NEXT COLD FRONT AND SHORT WAVE TROUGH MOVE
INTO THE CWA. 700MB FRONTOGENESIS SHOWS A DECENT AREA OF LIFT
TRAVERSING THE NORTHERN AND WESTERN PORTIONS OF THE CWA. INCLUDED
CHANCE POPS FOR SNOW STARTING AT 17Z IN EXTREME NORTHERN PORTIONS
OF THE CWA FROM NORTHERN YUMA COUNTY EAST TO NORTHERN RED WILLOW
COUNTY. AS THE AREA OF FRONTOGENESIS MOVES FROM NORTHEAST TO THE
SOUTH-SOUTHWEST...THE CHANCE OF SNOW WILL CONTINUE INTO TUESDAY
NIGHT. ACCUMULATIONS WILL BE AROUND A TENTH OF INCH SOUTH OF
HIGHWAY 36 TO AN INCH OVER AREAS NORTH OF HIGHWAY 36.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 224 AM MST TUE FEB 25 2014
THE ANTICIPATED PROLONGED PERIOD OF BELOW NORMAL TEMPERATURES IS
STILL ON TRACK FOR THIS WEEKEND INTO NEXT WEEK. UNFORTUNATELY...
MODEL DISAGREEMENT HAS INCREASED FOR THE 00Z SUITE OF MODEL GUIDANCE
SO CONFIDENCE IN TIMING OF PRECIPITATION CHANCES...TO WHAT EXTENT
THE TEMPERATURES WILL PLUNGE AND WHEN...IF AT ALL...A WARMING TREND
WILL BEGIN.
THERE WILL BE AT LEAST TWO CHANCES FOR PRECIPITATION IN THE EXTENDED
FORECAST PERIOD. THESE CHANCES COME AS TWO UPPER LEVEL DISTURBANCES
MOVE ACROSS THE HIGH PLAINS. THE FIRST DISTURBANCE PASSES THROUGH
FRIDAY INTO FRIDAY NIGHT. IT STILL APPEARS AS THOUGH THE MAIN LIFT
AND FORCING WITH THIS SYSTEM REMAINS TO THE SOUTH. HOWEVER...WITH A
STALLED FRONTAL BOUNDARY LINGERING SOMEWHERE ACROSS EAST COLORADO
AND WEST KANSAS...WOULD NOT BE SURPRISED IF THE LIFT ALONG THE FRONT
ALLOWED FOR SLIGHTLY HIGHER CHANCES OF PRECIPITATION. THE QUESTION
REMAINS OF WHERE EXACTLY THIS FRONTAL BOUNDARY WILL BE LOCATED.
THE SECOND UPPER LEVEL DISTURBANCE PASSES THROUGH SATURDAY INTO
SUNDAY. THE OVERALL SOLUTIONS FOR THIS SYSTEM HAVE CHANGED AND NOW
PROJECT A STRONG 500 MB TROUGH MOVING ONTO THE CALIFORNIA COAST
BEFORE WEAKENING AS IT CROSSES THE ROCKIES. THEN...THE WEAKER 500 MB
TROUGH BECOMES ENGULFED IN ANOTHER STRONGER 500 MB COMING SOUTHEAST
FROM CANADA AND EVENTUALLY MOVES THROUGH THE HIGH PLAINS AS A WEAKER
OPEN WAVE. WHILE PRECIPITATION CHANCES ARE STILL DECENT...THERE ARE
SOME CONCERNS THAT THIS SYSTEM COULD BYPASS THE REGION COMPLETELY.
MODEL DISAGREEMENT BECOMES A MUCH LARGER PROBLEM FROM SUNDAY NIGHT
ONWARDS. THE EUROPEAN BRINGS A RETURN TO ZONAL FLOW ACROSS THE
UNITED STATES. THIS TYPE OF PATTERN IS FAVORABLE FOR SOUTHWEST FLOW
AND WARMER TEMPERATURES TO RETURN. THE GFS KEEPS A LARGER UPPER
LEVEL TROUGH OVER THE PLAINS WITH ANOTHER STRONG ARCTIC HIGH MOVING
SOUTH...REINFORCING THE COLDER AIR. HAVE SIDED WITH THE GFS FOR THIS
RUN AS THE EUROPEAN HAS MADE A DRASTIC CHANGE FROM THE 00Z RUN
YESTERDAY. THEREFORE...KEPT THE COLDER AIR IN THE TRI-STATE AREA
WITH SLIGHT CHANCES FOR PRECIP AS SUGGESTED BY THE CR INITIALIZATION
PROCEDURE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1043 PM MST MON FEB 24 2014
EARLY IN THE PERIOD...KGLD WILL START OUT AT MVFR AND BECOME VFR
BY 12Z. THEN BOTH KGLD AND KMCK STAY VFR UNTIL EARLY AFTERNOON
WHEN MVFR CONDITIONS WILL DEVELOP AT KMCK. THOSE MVFR CONDITIONS
REMAIN UNTIL 02Z WHEN THE SNOW ENDS. AT KGLD...MVFR BEGINS NEAR
00Z AND WILL LAST TO ALMOST 06Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...ALW/JSL
LONG TERM...RRH
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1047 PM MST MON FEB 24 2014
.UPDATE...
ISSUED AT 742 PM MST MON FEB 24 2014
JUST ISSUED AN UPDATE TO LOWER MINS WITH SOME LOCATIONS ALREADY
GETTING CLOSE TO THE FORECAST. COLD ADVECTION MORE AGGRESSIVE THAN WHAT
THE CURRENT MODEL OUTPUT IS SAYING. USING CURRENT READINGS AND THE
LATEST HRRR TO MAKE THE ADJUSTMENT.
UPDATE ISSUED AT 556 PM MST MON FEB 24 2014
JUST COMPLETED AN UPDATE. MAIN CHANGE WAS THE WINDS. COLD FRONT
GOING THROUGH THE AREA AT THIS TIME WITH STRONG 3 HOUR PRESSURE
RISES AND TIGHT GRADIENT BEHIND IT. SO WINDS WERE INCREASED INTO
THE BREEZY TO WINDY CATEGORY. BY MID EVENING THE WINDS SHOULD
DECREASE WITH LIGHTER WINDS AFTER MIDNIGHT. MINOR ADJUSTMENT WAS
ALSO MADE TO THE SKY COVER TO INCREASE IT A LITTLE FASTER THAN
WHAT THE GRIDS DEPICTED.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 215 PM MST MON FEB 24 2014
MAIN FOCUS FOR THE SHORT TERM TODAY IS THE TEMPERATURES AND
PRECIPITATION CHANCES OVERNIGHT AND TOMORROW. TEMPERATURES TODAY
HAVE RISEN INTO THE MID 30S OVER THE NORTHEAST PORTIONS OF THE CWA
WHILE FURTHER WEST TEMPERATURES HAVE RISEN INTO THE LOW 60S IN
FLAGLER COLORADO ASSOCIATED WITH A WARM FRONT IN EASTERN COLORADO. THE
NORTHEAST PORTION OF THE CWA WILL REMAIN ON THE COOL SIDE WITH
HIGHS IN THE LOW 20S WHILE THE WEST/SOUTHWEST PORTIONS OF THE CWA
COOL DOWN SIGNIFICANTLY FROM TODAY TO TOMORROW WITH HIGHS
STRUGGLING TO REACH 30 AS A BACK DOOR COLD FRONT MOVES THROUGH
OVERNIGHT. BEHIND THE COLD FRONT...CLOUD COVER WILL INCREASE AND
THERE WILL BE A CHANCE FOR SNOW FLURRIES MOVING IN FROM THE
NORTHEAST. FOR TEMPERATURES AND PRECIPITATION...WENT WITH A BLEND
OF NAM...SREF...AND HRRR. BUFKIT SOUNDINGS BECOME SATURATED
SLIGHTLY ABOVE THE SURFACE AND BECOME DRIER TOWARDS THE SURFACE.
SINCE THE TEMPERATURE PROFILE IS BELOW ZERO AND THE COLUMN IS
FAIRLY SATURATED...CHANGED PRECIPITATION TYPE TO FLURRIES FROM
FREEZING FOG...FROM THE PREVIOUS FORECAST...SINCE THIS SEEMS MORE
LIKELY. FLURRIES SHOULD TAPER OFF AROUND 12Z AS SURFACE HIGH
PRESSURE SLIDES INTO THE CWA.
THE PERIOD OF NO PRECIPITATION TOMORROW MORNING WILL BE RATHER
SHORT-LIVED AS THE NEXT COLD FRONT AND SHORT WAVE TROUGH MOVE
INTO THE CWA. 700MB FRONTOGENESIS SHOWS A DECENT AREA OF LIFT
TRAVERSING THE NORTHERN AND WESTERN PORTIONS OF THE CWA. INCLUDED
CHANCE POPS FOR SNOW STARTING AT 17Z IN EXTREME NORTHERN PORTIONS
OF THE CWA FROM NORTHERN YUMA COUNTY EAST TO NORTHERN RED WILLOW
COUNTY. AS THE AREA OF FRONTOGENESIS MOVES FROM NORTHEAST TO THE
SOUTH-SOUTHWEST...THE CHANCE OF SNOW WILL CONTINUE INTO TUESDAY
NIGHT. ACCUMULATIONS WILL BE AROUND A TENTH OF INCH SOUTH OF
HIGHWAY 36 TO AN INCH OVER AREAS NORTH OF HIGHWAY 36.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 305 AM MST MON FEB 24 2014
TUESDAY EVENING AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE AREA.
AHEAD OF THE TROUGH AXIS THE RIGHT ENTRANCE OF THE 500-300 MB JET
STREAK AND 700-300MB FRONTOGENESIS WILL MOVE OVER THE AREA. HAVE
NOTICED THE FRONTOGENESIS HAS STRENGTHENED IN THE LATEST MODEL RUNS
GIVING ADDED CONFIDENCE THAT SNOWFALL WILL DEVELOP. SOUNDINGS
ACROSS THE AREA CONTINUE TO SHOW THE DENDRITIC LAYER ONLY A FEW
THOUSAND FEET OFF THE GROUND. WITH A DEEPLY SATURATED ENVIRONMENT
AND THE DENDRITIC ZONE NEAR THE SURFACE...CONTINUE TO THINK THE
LARGE SCALE LIFT AHEAD OF THE TROUGH WILL ALLOW SNOWFALL TO
DEVELOP. DUE TO THE LOW DEW POINTS IN THE TEENS AM THINKING THE
SNOW WILL BE FAIRLY DRY. DUE TO THE QUICK PASSAGE OF THE TROUGH AM
THINKING SNOW ACCUMULATIONS WILL BE FAIRLY SMALL. AFTER MIDNIGHT
THE TROUGH WILL BE SOUTHEAST OF THE AREA. BEHIND THE TROUGH SKIES
WILL CLEAR AND WINDS WILL BECOME LIGHT...ALLOWING TEMPERATURES TO
FALL NEAR THE DEW POINT.
WEDNESDAY AND WEDNESDAY NIGHT A WARM FRONT WILL MOVE THROUGH THE
AREA DURING THE MORNING ALLOWING TEMPERATURES WARM TO NEAR
NORMAL. OVERNIGHT A COLD FRONT WILL MOVE INTO THE NORTHEAST PART OF
THE AREA...COOLING TEMPERATURES TO AROUND 10 DEGREES BEHIND IT.
THURSDAY THROUGH MONDAY WILL BE DOMINATED BY CHANCES FOR SNOW AS
SEVERAL UPPER LEVEL SHORT WAVE TROUGHS MOVE ACROSS THE AREA. THE
FIRST TROUGH WILL MOVE THROUGH THURSDAY NIGHT...WITH THE MAJORITY OF
THE LIFT FROM THE TROUGH REMAINING SOUTH OF THE AREA...HOWEVER
MODELS SHOW A LARGE PLUME OF 1000-500MB MOISTURE MOVING SOUTHEAST
OVER THE AREA AS THE SMALLER SCALE TROUGH MOVES THROUGH. FRIDAY
THERE MAY BE SOME LINGERING SNOW IN THE MORNING AS THE TROUGH MOVES
OUT OF THE AREA. FRIDAY NIGHT THROUGH THE WEEKEND THE LONG WAVE
TROUGH OVER THE NORTHERN PART OF THE COUNTRY CONTINUES TO DIRECT
1000-500MB MOISTURE OVER THE AREA...ALLOWING CHANCES FOR SNOW TO
CONTINUE THROUGH THE WEEKEND AS ANOTHER STRONGER TROUGH MOVES IN
FROM THE WEST. THIS STRONGER TROUGH WILL MOVE OVER THE AREA
SUNDAY. BY MONDAY THE TROUGH WILL BE EAST OF THE AREA CAUSING
CHANCES FOR SNOW TO COME TO AN END.
TEMPERATURES FOR THE PERIOD WILL BE NEAR TO BELOW NORMAL. THURSDAY
AND FRIDAY THE COLD FRONT WILL WOBBLE EAST TO WEST ACROSS THE AREA.
FRIDAY NIGHT THE FRONT WILL BE PUSHED EAST AS THE LONG WAVE TROUGH
OVER THE NORTHERN PLAINS MOVES SOUTHWARD. BEHIND THE FRONT MUCH
COOLER AIR WILL MOVE INTO THE AREA...WITH TEMPERATURES 10-20 DEGREES
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1043 PM MST MON FEB 24 2014
EARLY IN THE PERIOD...KGLD WILL START OUT AT MVFR AND BECOME VFR
BY 12Z. THEN BOTH KGLD AND KMCK STAY VFR UNTIL EARLY AFTERNOON
WHEN MVFR CONDITIONS WILL DEVELOP AT KMCK. THOSE MVFR CONDITIONS
REMAIN UNTIL 02Z WHEN THE SNOW ENDS. AT KGLD...MVFR BEGINS NEAR
00Z AND WILL LAST TO ALMOST 06Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...ALW/JSL
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1159 PM EST MON FEB 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 357 PM EST MON FEB 24 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PERSISTENT...COLD
NW FLOW DOMINATING THE GREAT LKS BTWN RDG ALONG THE W COAST AND
CLOSED LO OVER QUEBEC/TROF IN ERN NAMERICA. COMBINATION OF SHRTWV
EMBEDDED IN NW FLOW ALF...DEEPER MSTR SHOWN ON THE 12Z INL RAOB...
H85 TEMPS IN THE -18C TO -21C RANGE AND SOME OPEN WATER ON LK SUP
HAS RESULTED IN SOME GENERALLY LGT LES IN AREAS FAVORED BY THE LLVL
WNW FLOW. OVER THE INTERIOR...SOME DIURNAL CU/SC HAVE DVLPD IN
RATHER MOIST AIRMASS WITH INCRSG SUN ANGLE CAUSING SOME LLVL
DESTABILIZATION. BTWN THE SHRTWV MOVING THRU THE UPR LKS EARLY THIS
AFTN AND ANOTHER STRONGER DISTURBANCE STRETCHING FM NEAR LK WINNIPEG
INTO THE NRN PLAINS/ACCOMPANYING -SN MOVING THRU THE DAKOTAS...
SHRTWV RDG/AXIS OF DRIER MID LVL AIR IS BRINGING GENERALLY MOSUNNY
WX TO MUCH OF MN EXCEPT THE ARROWHEAD. YET ANOTHER SHRTWV IS
DROPPING SWD FM THE NW TERRITORIES OF CANADA INTO NRN SASKATCHEWAN/
MANITOBA.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LES TRENDS AND TEMPS
ASSOCIATED WITH THE STEADY PARADE OF DISTURBANCES EMBEDDED IN NW
FLOW ALF.
TNGT...WITH APRCH AND PASSAGE OF SHRTWV RDG LATER THIS AFTN AND THIS
EVNG/ACCOMPANYING DEEP LYR QVECTOR DVGC AND SUBSIDENCE...EXPECT
LINGERING LES TO AT LEAST DIMINISH IN INTENSITY/COVERAGE FOR A TIME.
BUT AS SHRTWV NOW MOVING INTO THE NRN PLAINS SHIFTS TO THE SE
TNGT...AREA OF ACCOMPANYING DEEP LYR QVECTOR CNVGC/MORE MSTR AND SFC
COLD FNT ARE FCST TO IMPACT THE AREA MAINLY AFT MIDNGT. ALTHOUGH ALL
MODELS SHOW THE ACCOMPANYING SYNOPTIC SCALE PCPN PASSING TO THE S OF
THE CWA CLOSER TO CORE OF UPR DVGC ON CYC SIDE OF H3 JET MAX...
EXPECT AN INCRS IN LES COVERAGE NEAR LK SUP OVERNGT. TEMPS COULD
FALL OFF QUICKLY THIS EVNG OVER AT LEAST THE INTERIOR NEAR THE WI
BORDER AS AXIS OF DRIER AIR AT LEAST BRIEFLY MOVES OVHD BEFORE
THICKER CLDS ASSOCIATED WITH DISTURBANCE NEAR LK WINNIPEG ARRIVE
LATER.
TUE...WHILE THERE MAY BE SOME MID LVL DRYING/SUBSIDENCE EARLY ON TUE
WITH A PERIOD OF QVECTOR DVGC FOLLOWING THE DEPARTING DISTURBANCE...
SHRTWV NOW DROPPING S INTO SASKATCHEWAN/MANITOBA IS FCST TO BRING A
RETRUN OF MORE DYNAMIC SUPPORT/SOME DEEPER MSTR BY THE AFTN...
ESPECIALLY OVER THE NE HALF OF THE CWA. SO EXPECT INCRSG LES POPS
AGAIN IN THE WNW WIND SN BELTS NEAR THE LK. GIVEN H85 TEMPS FALLING
AOB -25C BY LATE IN THE DAY CAUSING THE NEAR ELIMINATION OF THE DGZ
AS WELL AS CONSIDERABLE ICE COVER OVER LK SUP...EXPECT SN AMOUNTS TO
BE RELATIVELY LIGHT. TUE WL BE ANOTHER UNSEASONABLY COLD DAY. TENDED
TOWARD THE LO END OF GUIDANCE FOR MAX TEMPS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 406 PM EST MON FEB 24 2014
THE FIRST IN A SERIES OF UPPER LEVEL DISTURBANCES THAT WILL BRING
COLDER AIR TO THE AREA WILL BE SWEEPING ACROSS UPPER MICHIGAN
TUESDAY AFTERNOON AND EARLY TUESDAY EVENING. THIS SHORTWAVE WILL
USHER IN SLIGHTLY COLDER 850MB TEMPS ON TUESDAY NIGHT (-28C) AND
WITH WINDS OUT OF THE NORTHWEST...WOULD EXPECT AT LEAST A BRIEF
PERIOD OF LIGHT TO MODERATE LAKE EFFECT SNOW IN THE NORTHWEST WINDS
SNOW BELTS DURING THE EVENING. BUT MODELS ARE SHOWING DRY AIR ABOVE
850MB MOVING IN QUICKLY AFTER 06Z WEDNESDAY...SO THAT SHOULD CUT OUT
THE INTENSITY HEADING INTO THE OVERNIGHT HOURS. GETTING A GOOD
HANDLE ON ICE COVER OVER THE WESTERN LAKE TODAY...WITH OPEN WATER
GENERALLY NORTHWEST OF A LINE FROM THE APOSTLE ISLANDS TO TERRACE
BAY ONTARIO. THAT GAP OF 30-40MI IS PLENTY TO SUPPORT LAKE EFFECT
CLOUDS AND SNOW...WHICH HAS BEEN SEEN THIS MORNING OVER WESTERN
UPPER MICHIGAN. THEREFORE...WILL CONTINUE TO SHOW LIKELY POPS IN
THE NORTHWEST WIND AREAS OVER THE WEST IN THE EVENING AND DIMINISH
SLIGHTLY OVERNIGHT WITH THE INCREASING DRY AIR AND BACKING WINDS
ASSOCIATED WITH A WEAK HIGH PRESSURE RIDGE. THE EAST IS A LITTLE
MORE COMPLICATED...SINCE THE ONLY POCKET OF OPEN WATER IS THE AREA
TO THE EAST OF THE KEWEENAW PENINSULA AND SOUTH TO MARQUETTE. WITH
THE NORTHWEST WINDS...THAT WOULD SUPPORT THE HIGHEST POPS/AMOUNTS
OVER ALGER COUNTY AND THINK FARTHER EAST INTO LUCE COUNTY (EVEN THE
EASTERN THIRD OF ALGER COUNTY) WOULD SEE LESS ACCUMULATION AND MORE
SCATTERED SNOW SHOWERS WITH THE AMOUNT OF ICE THE BANDS ORIGINATING
NORTHEAST OF ISLE ROYALE WOULD HAVE TO PASS OVER.
THE WEAK HIGH PRESSURE WILL SLIDE ACROSS THE U.P. LATE TUESDAY
NIGHT AND WEDNESDAY MORNING...AS THE NEXT SHORTWAVE AND LOW
PRESSURE SYSTEM DIVE SOUTHEAST OUT OF WESTERN ONTARIO WEDNESDAY
AFTERNOON AND ACROSS LAKE SUPERIOR AT 998MB ON WEDNESDAY EVENING.
THE BEST SNOW ASSOCIATED WITH THIS LOW AND SHORTWAVE WILL LIKELY BE
NEAR THE SURFACE LOW WITH THE LOWER LEVEL DRY AIR BEING PULL
NORTHEAST ACROSS UPPER MICHIGAN. ANY SYNOPTIC SNOW SHOULD BE LIGHT
AND ONLY CREATE A LIGHT DUSTING...MAINLY NEAR LAKE SUPERIOR. BUT
BEHIND THE LOW...EXPECT ANOTHER OPPORTUNITY FOR LAKE EFFECT SNOW IN
NORTHWEST TO NORTH-NORTHWEST WIND AREAS. THE 925MB WINDS WILL BE
FAIRLY STRONG (35KTS) BEHIND THE FRONT AND WILL LIKELY LIMIT THE
RESIDENCE TIME OVER THE 30-40MI STRETCH OF OPEN WATER. WOULD EXPECT
THIS TO LIMIT SNOWFALL AMOUNTS EVEN THOUGH DELTA-T VALUES ARE
NEARING 30-32 AND INVERSION HEIGHTS ARE BETWEEN 10-14KFT. ALTHOUGH
SNOW AMOUNTS MAY NOT BE TOO SIGNIFICANT...THINK THE PERIOD OF VERY
GUSTY NORTHWEST WINDS ON THE BACK SIDE OF THE LOW (GUSTS NEAR LAKE
SUPERIOR OF 30-40KTS NEAR LAKE SUPERIOR FROM ONTONAGON TO WHITEFISH
POINT) WILL CREATE A SIGNIFICANT CONCERN FOR WIDESPREAD BLOWING AND
DRIFTING SNOW. HAVE TRENDED WINDS UP 5-10KTS FOR THIS PERIOD WITH
THE CONSISTENCY IN THE MODELS ON THIS WINDY IDEA. WILL ALSO ADD A
MENTION OF THE POTENTIAL FOR CONSIDERABLE BLOWING AND DRIFTING SNOW
NEAR LAKE SUPERIOR IN THE HWO THAT WILL DEVELOP WEDNESDAY NIGHT
AND CONTINUE INTO THURSDAY MORNING. ADD FINE FLAKE SNOW FALLING WITH
THE BLOWING SNOW SHOULD EASILY CREATE VISIBILITIES OF 1/2MI OR
LESS IN THE KEWEENAW. THE GUSTY WINDS WILL COMBINE WITH TEMPERATURES
BELOW ZERO ON THURSDAY MORNING TO ALSO CREATE A CONCERN FOR WIND
CHILL HEADLINES FOR A GOOD PORTION OF UPPER MICHIGAN. CURRENT
FORECAST HAS WIND CHILL VALUES OF -25 TO -35 DEGREES AND WITH THE
POTENTIAL FOR BLOWING SNOW IT COULD EVENTUALLY BE TIED TOGETHER WITH
A WINTER WX ADVISORY.
ONCE AGAIN...A HIGH PRESSURE RIDGE (FROM A HIGH MOVING INTO THE
UPPER MISSISSIPPI VALLEY) WILL QUICKLY MOVE OVER UPPER MICHIGAN ON
THURSDAY AFTERNOON INTO THURSDAY NIGHT. THIS SHOULD RAPIDLY
DIMINISH WINDS OVER THE AREA DURING THE AFTERNOON. MODELS CONTINUE
TO SHOW HIGHS ONLY REACHING AROUND 0 DEGREES ON THURSDAY...WHICH
WOULD PUT SEVERAL COLD HIGH TEMPERATURE RECORDS IN JEOPARDY SINCE
MOST ARE IN THE MID SINGLE DIGITS ABOVE ZERO. FOR THE LONG PERIOD OF
RECORD SITES...MOST OF THOSE RECORDS DATE BACK TO THE LATE 1800S AND
EARLY 1900S. WOULD EXPECT SKIES TO CLEAR OUT AWAY FROM ANY LAKE
EFFECT NEAR LAKE SUPERIOR THURSDAY AFTERNOON AND CONTINUE INTO
THURSDAY NIGHT. THINK THIS WILL LEAD TO A VERY COLD NIGHT ACROSS THE
AREA AND WILL CONTINUE TO SHOW LOWS IN THE 10S TO MID 20S BELOW ZERO
(COLDEST INTERIOR COLD SPOTS).
ANOTHER SHORTWAVE WILL ROUND THE EASTERN CANADA UPPER TROUGH ON
FRIDAY AND DIVE SOUTHEAST ACROSS UPPER MICHIGAN FRIDAY NIGHT. THE
COLD AIR ASSOCIATED WITH THIS WAVE WILL LEAD TO ANOTHER DAY OF
HIGHS ABOUT 30 DEGREES BELOW NORMAL ON SATURDAY. LAKE EFFECT
POTENTIAL CONTINUES FRIDAY NIGHT INTO SATURDAY...BUT WORRIED THAT
THE VERY COLD TEMPS AND LIGHT WINDS ON THURSDAY NIGHT INTO FRIDAY
WILL LEAD TO A FAST ICE UP OF THE OPEN AREAS AND CUT OFF LAKE
EFFECT. WILL GO WITH SLIGHT AND LOW CHANCE POPS AT THIS POINT DUE TO
THE UNCERTAINTY. EXTENDED MODELS ARE SHOWING A TREND TOWARDS MORE
ZONAL FLOW AND GRADUALLY WARMING TEMPERATURES SUNDAY AND HEADING
INTO NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1158 PM EST MON FEB 24 2014
A COUPLE OF DISTURBANCES PASSING THRU THE AREA...ONE OVERNIGHT AND
THE SECOND THIS AFTN...WILL BRING AN UPTICK IN LAKE EFFECT SHSN AND
BLSN AT KIWD/KCMX...THOUGH THERE IS SOME CONCERN WITH HOW FAST ICE
MAY BE EXPANDING INTO THE OPEN WATER AREAS THAT DEVELOPED OVER WRN
LAKE SUPERIOR DUE TO STRONG WINDS OVER THE LAST SEVERAL DAYS.
ASSUMING ENOUGH OPEN WATER REMAINS...IFR CONDITIONS SHOULD DEVELOP
AT KCMX OVERNIGHT WITH IFR CONDITIONS MOST LIKELY TODAY IN
ASSOCIATION WITH SECOND DISTURBANCE. WHILE THERE MAY BE SOME
-SHSN/MVFR CONDITIONS LATER IN THE NIGHT AT KIWD...IFR CONDITIONS
WILL MORE LIKELY DEVELOP THIS AFTN AS WINDS VEER TOWARD THE NW WITH
SECOND DISTURBANCE. AT KSAW...DOWNSLOPE WESTERLY WINDS WILL WORK TO
MAINTAIN VFR CONDITIONS INTO THE MORNING. DAYTIME HEATING WILL THEN
LIKELY RESULT IN AN MVFR CIG DEVELOPING WITH THE ARRIVAL OF MORE
UNSTABLE AIR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EST MON FEB 24 2014
WEST TO NORTHWEST WINDS OF 15-25KTS WILL CONTINUE TONIGHT THROUGH
TUESDAY NIGHT...BUT THEN BACK ON WEDNESDAY MORNING AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. A TIGHTENING GRADIENT AHEAD OF
THAT LOW COULD LEAD TO A FEW GALE FORCE GUSTS TO 35KTS AROUND
MID-DAY WEDNESDAY. THEN AS THE LOW DROPS SOUTHEAST ACROSS EASTERN
LAKE SUPERIOR ON WEDNESDAY EVENING...EXPECT A RAPID SWITCH AND
INCREASE IN THE WINDS FROM THE NORTHWEST AND CURRENT THOUGHT IS
THAT MUCH OF THE LAKE WILL SEE GALE FORCE GUSTS TO 35-40KTS. A HIGH
PRESSURE RIDGE WILL QUICKLY MOVE OVER THE AREA THURSDAY
AFTERNOON/NIGHT AND WEAKEN THE WINDS. ANOTHER TROUGH MOVING THROUGH
ON FRIDAY NIGHT WILL INCREASE WINDS BACK TO 15-25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
300 AM CST TUE FEB 25 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 259 AM CST TUE FEB 25 2014
CLOUDS AND OCCASIONAL FLURRIES ARE LINGERING IN THE AREA. SUBJECTIVE
00Z UPPER AIR ANALYSIS INDICATES UPPER-LEVEL SHORTWAVE TROUGH NEAR
THE SD/ND BORDER...WITH 500MB HEIGHT FALLS UP TO 90M AHEAD OF IT IN
EASTERN SD. 08Z WATER VAPOR AND RAP 1.5 PVU PRESSURE INDICATE
STRONG UPPER-LEVEL TROUGH DIGGING THROUGH IA THIS MORNING...WITH
SECONDARY SHORTWAVE UPSTREAM IN NORTHERN MT. STRONGEST UPPER-LEVEL
JET EXTENDED FROM MT THROUGH WESTERN SD INTO EASTERN NEB/IA AND
EASTWARD ACROSS THE MID-ATLANTIC. MUCH COLDER AIR WAS FILTERING
INTO THE PLAINS IN WAKE OF THE TROUGH...WITH 850MB TEMPERATURES -20C
OR COLDER IN ND/MT AND UPPER TEENS BELOW ZERO SPILLING INTO SD.
MAIN FORECAST CONCERN IS POTENTIAL FOR LIGHT SNOW TO CLIP THE
SOUTHWEST CWA TODAY...THEN ONE MORE DAY OF MODERATE TEMPERATURES
BEFORE THE COLD AIR PLUNGES INTO THE PLAINS. WEAK LIFT IN THE
DENDRITIC ZONE WILL EXIT THE AREA BY THIS MORNING...AND FLURRIES
SHOULD END FOR A TIME. SECOND...WEAKER SHORTWAVE WILL SLIDE THROUGH
THE NORTHERN ROCKIES TOWARD WESTERN/CENTRAL NEB TODAY...WITH WEAK
FRONTOGENETIC BAND AROUND 700-650MB SETTING UP FROM WESTERN TO SOUTH
CENTRAL NEB THIS AFTERNOON. SHOULD SEE SNOW WITH THAT BAND...BUT
EASTERN EXTENT IS IN QUESTION AS BETTER SUPPORT REMAINS WEST OF THE
AREA...AND DRIER LOW-LEVEL AIR BELOW THE MORE SATURATED MID-LEVELS
MAY HINDER MEASURABLE SNOW. HAVE CONTINUED TO INDICATE SLIGHT CHANCE
OF SNOW IN SOUTHEAST NEB THIS AFTERNOON...TAPERING AWAY BY THIS
EVENING.
WESTERLY WINDS RETURN TO THE AREA ON WEDNESDAY. WHILE SNOW ON THE
GROUND WILL HINDER TEMPERATURES IN THE NORTHERN CWA...THE COUPLE OF
TENTHS THAT FELL ELSEWHERE ARE NOT LIKELY TO COUNTERACT THE
FAVORABLE MIXING WINDS. HAVE KEPT TEMPS ABOVE GUIDANCE IN THE 30S
ACROSS MOST OF THE AREA...AS THE LAST DAY THAT COULD RISE ABOVE
FREEZING FOR QUITE SOME TIME. REINFORCING COLD AIR ARRIVES ON
WEDNESDAY NIGHT/THURSDAY AS A COLD AND DRY HIGH PRESSURE SLIDES OUT
OF THE DAKOTAS/MN INTO WESTERN IA. MID-LEVEL WARM AIR ADVECTION IS
PROGGED TO DEVELOP ON THE WESTERN SIDE OF THE HIGH ON THURSDAY
NIGHT...BUT GIVEN DRY AIR FEEDING IN FROM THE EAST...BELIEVE PRECIP
WILL BE HELD AT BAY THROUGH 12Z FRIDAY. MODELS HAVE TRENDED IN THAT
DIRECTION AS WELL...WITH ALL SOLUTIONS BUT THE NAM NOW DRY FOR
THURSDAY NIGHT. HAVE REMOVED POPS ACROSS THE AREA.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 259 AM CST TUE FEB 25 2014
ALTHOUGH THERE IS A BRIEF ATTEMPT AT MODERATION ON FRIDAY...PATTERN
TURNS COLDER THROUGH THE WEEKEND/MONDAY...WITH MUCH BELOW
NORMAL TEMPERATURES AND CHANCES OF LIGHT SNOW PERSISTING.
GOOD AGREEMENT BETWEEN 00Z GFS/ECMWF IN A DECENT H7 LOW/TROUGH
MOVING ALONG KS BORDER FRIDAY BRINGING MODEST SNOW CHANCES TO MUCH
OF THE FA...ESPECIALLY CNTRL/SRN ZONES. AFTER THAT THE COLD AIR IS
REINFORCED OVER THE NRN/CENTRAL PLAINS AS SEVERAL LOBES PIVOT AROUND
HUDSON BAY LOW SENDING COLD HIGH PRESSURE SOUTHWARD. MEANWHILE...
THE MID LEVEL FLOW OVER THE PLAINS REMAINS MORE WRLY AND EVEN
SWRLY AT TIMES. THUS PERIODS OF SNOW CHANCES WILL
PERSIST...ALTHOUGH NO MAJOR SYSTEMS WERE CURRENTLY SUGGESTED FOR
FA BY 00Z MODELS. BASED ON 00Z RUNS OF GFS/ECMWF IT DOES APPEAR
SOMEWHAT OF A LULL POSSIBLE FRIDAY NIGHT OVER MUCH OF THE
AREA...SATURDAY ACROSS THE SOUTH AND THEN MOST OF THE REGION BY
MONDAY. PRECIPITATION MENTION DURING THOSE TIMES WAS KEPT MOSTLY
IN THE SLIGHT CHANCE CATEGORY...ALTHOUGH WITH MID LEVEL
TEMPERATURES FAVORABLE FOR ICE CRYSTAL GENERATION IT WOULD NOT
TAKE MUCH TO GENERATE AREAS OF LIGHT SNOW ANY OF THOSE PERIODS IF
MOISTURE IS PRESENT. WITH H85 TEMPERATURES OF -15 TO -25 FORECAST
TO SAG SWD THROUGH FA SAT/SUN...MAX TEMPERATURES MAY REMAIN IN
SINGLE DIGITS MANY AREAS SATURDAY AND POSSIBLY EVEN SUNDAY NRN
ZONES WITH MEX/ECE GUIDANCE POSSIBLY INFLUENCED BY CLIMO WITH
NORMAL HIGHS NOW APPROACHING OR EXCEEDING 40 DEGREES F. TRIMMED
BACK HIGHS A BIT SATURDAY/SUNDAY. LEFT LOWS MOSTLY ALONE FOR
NOW...SINGLE DIGITS EITHER SIDE OF ZERO F...AS CLOUD INFLUENCES
ENOUGH OF A THREAT WITH THE WEST OR POSSIBLY SW MID LEVEL FLOW
RIDING OVER COLD LOW LEVEL FLOW.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1118 PM CST MON FEB 24 2014
MVFR CEILINGS WILL LINGER OVERNIGHT...ESPECIALLY AT KOFK AND KOMA.
SNOW SHOULD GRADUALLY END BUT SOME RESTRICTIONS MAY OCCUR UNTIL AT
LEAST 09Z. NORTH OR NORTHWEST WINDS CONTINUE TO INCREASE AS THE
COLD FRONT PUSHES SOUTHEASTWARD. WINDS WILL DECREASE TUESDAY
MORNING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MAYES
LONG TERM...CHERMOK
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
308 AM CST TUE FEB 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN FORECAST CONCERN WILL BE WIND CHILL HEADLINES. EARLY
MORNING SURFACE ANALYSIS SHOWS SURFACE HIGH PRESSURE STRETCHING
FROM EASTERN MONTANA INTO SOUTHEAST SOUTH DAKOTA. TEMPERATURES
EARLY THIS MORNING WERE IN THE SINGLE DIGITS AND TEENS BELOW ZERO
WITH WINDS OF 5 TO 10 MPH. THIS HAS DROPPED WIND CHILLS INTO
ADVISORY LEVELS ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA...THE EXCEPTION BEING FAR WEST CENTRAL NORTH DAKOTA WHERE
WINDS REMAIN WEAKEST.
THE FAR SOUTHWEST HAS ALSO SEEN AN INCREASE IN MID AND HIGH LEVEL
CLOUDS EARLY THIS MORNING HELPING TEMPERATURES GAIN A FEW DEGREES
OVER THE PAST COUPLE OF HOURS. NOT CONFIDENT THAT TREND WILL
CONTINUE SINCE THE LATEST HRRR SUGGESTS THE CLOUDS WILL SINK SOUTH
AGAIN THIS MORNING. OVERALL...THE WIND CHILL HEADLINE IS STILL
SUPPORTED BY THE LATEST OBSERVATIONS AND WILL NOT MAKE ANY CHANGES
TO IT.
WIND CHILLS WILL AGAIN BE THE MAIN CONCERN TONIGHT WITH LOWS OF 5
TO 15 BELOW AND WIND SPEEDS OF 10 MPH...INCREASING TO NEAR 20 MPH
OVERNIGHT. THIS AGAIN DROPS WIND CHILLS IN THE 25 TO 35 BELOW
RANGE ACROSS MUCH OF THE NORTH AND EAST. WILL KEEP THINGS SIMPLE
AND NOT ISSUE ADDITIONAL HEADLINES...BUT EXPECT LATER SHIFTS WILL
LIKELY NEED TO CONSIDER THAT POSSIBILITY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN HIGHLIGHTS FOR THE EXTENDED WILL BE THE WELL BELOW NORMAL
TEMPERATURES AND SNOW CHANCES THIS WEEKEND. MODELS ARE IN FAIRLY
GOOD AGREEMENT SO USED A BLEND FOR THIS PACKAGE.
WEDNESDAY STILL LOOKS TO BE THE WARMEST DAY OF THE WEEK WITH HIGHS
GENERALLY FROM THE TEENS EAST TO THE MID 20S SOUTHWEST.
HOWEVER...IT WILL ALSO BE THE WINDIEST DAY OF THE PERIOD AS HIGH
PRESSURE SURGES INTO THE REGION. SNOW FROM MONDAY`S EVENT COMBINED
WITH THESE WINDS SHOULD GENERATE PATCHY TO AREAS OF BLOWING
SNOW...MAINLY ON WEDNESDAY AFTERNOON. WINDS WILL DECREASE RAPIDLY
WEDNESDAY NIGHT AS HIGH PRESSURE SETTLES ACROSS THE REGION. COLD
AND DRY CONDITIONS WILL CONTINUE ACROSS THE REGION THURSDAY AS
HIGH PRESSURE SHIFTS EAST OF THE REGION.
BY FRIDAY...A REINFORCING COLD FRONT WILL PUSH THROUGH THE
NORTHERN PLAINS...WITH A BAROCLINIC ZONE SETTING UP OVER
SOUTHWESTERN NORTH DAKOTA. THIS WILL GENERATE A SLIGHT CHANCE FOR
SNOW OVER SOUTHWESTERN NORTH DAKOTA FRIDAY INTO FRIDAY NIGHT.
A SHORTWAVE ROTATING OVER THE NORTHERN ROCKIES AND INTO THE
NORTHERN PLAINS THIS WEEKEND IS PROGGED TO LIFT THE SNOW CHANCES
NORTH SATURDAY AND SUNDAY. HOWEVER...GIVEN THE WEAK UPPER LEVEL
FORCING...SNOW AMOUNTS ARE EXPECTED TO REMAIN FAIRLY LIGHT.
AS THE UPPER WAVE DEPARTS THE STATE MONDAY...DRY CONDITIONS ARE
EXPECTED BY THE BEGINNING OF THE NEXT WORK WEEK. COLD TEMPERATURE
ARE FORECAST TO CONTINUE AS WELL WITH HIGHS IN THE SINGLE DIGITS
ABOVE ZERO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 308 AM CST TUE FEB 25 2014
EARLY MORNING SATELLITE IMAGERY SHOWS VFR CONDITIONS WITH MAINLY
CLEAR SKIES ACROSS THE TAF LOCATIONS. EXPECT VFR CONDITIONS TO
REMAIN IN PLACE...HOWEVER SCATTERED TO BROKEN CLOUDS AROUND 3500
FT ACROSS SOUTHERN SASKATCHEWAN / MANITOBA COULD MOVE INTO
NORTHERN AERODROMES BY 12Z...WORKING THEIR WAY SOUTH THROUGH THE
MORNING. WILL SHOW THE CLOUDS PROGRESSION ACROSS THE TAF
LOCATIONS...WITH MAINLY CLEAR SKIES PREVAILING ONCE THEY EXIT.
WINDS SHOULD BE LIGHT THIS MORNING...BUT WILL BECOME MORE STEADY
FROM THE NORTHWEST AFTER SUNRISE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST /9 AM MST/ THIS MORNING FOR
NDZ001>005-009>013-018>023-025-033>037-040>048-050-051.
&&
$$
SHORT TERM...CK
LONG TERM...TM
AVIATION...CK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1245 AM CST TUE FEB 25 2014
.UPDATE...
ISSUED AT 1245 AM CST TUE FEB 25 2014
EARLY MORNING SURFACE ANALYSIS SHOWED HIGH PRESSURE STRETCHING
FROM EASTERN MONTANA INTO CENTRAL SOUTH SOUTH DAKOTA. WINDS HAVE
BECOME LIGHT DUE TO THE PLACEMENT OF THE RIDGE AXIS...HOWEVER
DUE TO VERY COLD TEMPERATURES...WIND CHILLS ARE STILL REACHING
ADVISORY LEVELS. THE EXCEPTION REMAINS IN THE FAR WEST CENTRAL
PORTION OF THE STATE IN THE HEART OF THE RIDGE AXIS WHERE WINDS
ARE WEAKEST. DID NOT MAKE ANY ADJUSTMENTS TO THE WIND CHILL
ADVISORY SINCE IT STILL LOOKS APPROPRIATELY PLACED.
MADE MINOR ADJUSTMENTS TO CLOUDS OVERNIGHT WITH MID AND HIGH LEVEL
CLOUDS MOVING ACROSS SOUTHWEST NORTH DAKOTA. THIS IS PICKED UP
WELL BY THE LATEST HRRR WHICH SUGGESTS THINNING CLOUDS AGAIN AFTER
SUNRISE TUESDAY.
UPDATE ISSUED AT 829 PM CST MON FEB 24 2014
LATEST SURFACE ANALYSIS AND SATELLITE IMAGERY SHOWS GENERALLY
CLEAR SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA. TEMPERATURES
ARE COOLING MUCH QUICKER ACROSS THE NORTHWEST WITH CROSBY ALREADY
AT 11 BELOW. UPSTREAM DEW POINTS NEAR 20 BELOW AND ADJUSTED MIN
TEMPERATURES IN THE UPPER TEENS BELOW ZERO OVERNIGHT FOR THE
NORTH. THIS RESULTED IN THE EXPANSION OF THE WIND CHILL
ADVISORY...NOW COVERING DIVIDE AND WILLIAMS COUNTIES. FARTHER
UPSTREAM...SCT/BKN CLOUDS AT 4000FT TO 5000FT IN CENTRAL
SASKATCHEWAN AND MANITOBA ARE SLIDING SOUTHEAST IN ASSOCIATION
WITH A WEAK SURFACE COLD FRONT AND AN H85 COLD POCKET. A LINEAR
EXTRAPOLATION WOULD PUT THIS AREA OF CLOUDS INTO OUR NORTHERN
ZONES BETWEEN 10Z AND 12Z TUESDAY. THIS MAY POSSIBLY WARM
TEMPERATURES ABOVE WIND CHILL ADVISORY CRITERIA AND WILL PASS THIS
ONTO THE MID SHIFT. ELSEWHERE...COOLED TEMPERATURES A FEW MORE
DEGREES OVERNIGHT WITH WIND CHILL ADVISORY TEMPERATURES SOLIDLY IN
PLACE EXCEPT IN THE FAR WEST. UPDATES TO THE TEXT PRODUCTS
FORTHCOMING.
UPDATE ISSUED AT 553 PM CST MON FEB 24 2014
THE LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH NOW INTO THE
JAMES RIVER VALLEY WITH THE TAIL END OF VERTICAL MOTION/LIGHT SNOW
OVER OAKES. THE CURRENT POP GRIDS HAVE THIS HANDLED WELL AS THE
PRECIPITATION WILL END WITHIN THE NEXT HOUR OR TWO. SKY CONDITION
IS TRENDING MOSTLY CLEAR UPSTREAM. AN H85 COLD POCKET/TROUGH
ASSOCIATED WITH -24C TEMPERATURES NORTH OF MANITOBA WILL SAG SOUTH
INTO NORTHERN NORTH DAKOTA AFTER MIDNIGHT...AND INTO SOUTH CENTRAL
BY MID TUESDAY MORNING. LAPSE RATES IN THE 925MB-H85 LAYER ARE
WEAK...BUT TIME HEIGHT/RH CROSS SECTIONS SHOW A BRIEF PERIOD/3 HRS
OF PARTLY CLOUDY TO MOSTLY CLOUDY CONDITIONS TUESDAY MORNING.
UPSTREAM OBS IN CENTRAL SASKATCHEWAN AND MANITOBA CONFIRM THIS.
THE CURRENT WIND CHILL ADVISORY IS ON TRACK AND WILL MONITOR THIS
EVENING...BUT NOT EXPECTING ANY SIGNIFICANT CHANGES TO CURRENT
FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 307 PM CST MON FEB 24 2014
MAIN FORECAST ISSUES ARE LIGHT SNOW AFFECTING THE SOUTHEAST
THROUGH LATE AFTERNOON AND CONTINUED COLD CONDITIONS OVERNIGHT. WV
IMAGERY SHOWED SHORTWAVE IN NORTHWEST FLOW MOVING ACROSS ND THIS
AFTERNOON WITH WEAK INVERTED SURFACE TROUGH NUDGING INTO
SOUTH CENTRAL ND SUPPORTING AREA OF LIGHT SNOW. VIS IMAGERY SHOWS
BACK EDGE OF CLOUD COVER STEADILY PROGRESSING SOUTHEASTWARD WITH
CLEAR SKIES NOW OVER MUCH OF WESTERN AND NORTHERN ND.
ANY LINGERING SNOW SHOULD QUICKLY DEPART THE SOUTHEAST BY EARLY
EVENING. ACCUMULATIONS HAVE BEEN LIGHT...GENERALLY LESS THAN AN
INCH DESPITE SURFACE OBS SHOWING VISIBILITY DOWN TO A MILE FOR
SEVERAL HOURS. TONIGHT...SURFACE RIDGE BUILDS IN FROM THE
NORTHWEST WITH SURFACE WINDS MOST AREAS 10 TO 15 MPH...A LITTLE
LIGHTER ACROSS THE WEST. WIND CHILL VALUES MOST AREAS FALL INTO
THE ADVISORY CATEGORY...SO HAVE ISSUED A WIND CHILL ADVISORY FOR
ALL BUT WEST CENTRAL AND NORTHWEST SECTIONS.
DRY AND COLD CONDITIONS CONTINUE ON TUESDAY AS SURFACE HIGH CENTER
SINKS TO EASTERN MONTANA/WESTERN ND DURING THE DAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 307 PM CST MON FEB 24 2014
THE MAIN FORECAST ISSUES DURING THE LONG TERM PERIOD ARE
TEMPERATURES AND WIND CHILLS...WITH THE EXCEPTION OF A WARMER AND
WINDIER DAY ON WEDNESDAY.
ON TUESDAY NIGHT AN ARCTIC HIGH PRESSURE DOME WILL BE EXITING THE
AREA TO THE SOUTHEAST AS A CLIPPER LOW PRESSURE SYSTEM NEAR HUDSON
BAY DROPS SOUTHEAST QUICKLY...DRAGGING A COLD FRONT SOUTH ACROSS
NORTH DAKOTA DURING THE DAYTIME WEDNESDAY. AHEAD OF THE COLD
FRONT...SOUTHWEST WINDS WILL INCREASE AND ALLOW SOME WARM ADVECTION
INTO THE STATE. TEMPERATURES SHOULD BE ABLE TO RECOVER TO NEAR 10
ABOVE IN THE TURTLE MOUNTAINS...REACH THE TEENS ALONG AND EAST OF
THE MISSOURI RIVER...AND MAKE IT INTO THE 20S SOUTH AND WEST OF THE
MISSOURI RIVER. THE SOUTHWEST WINDS WILL INCREASE AND BECOME
NORTHWEST AT 15 TO 25 MPH SOUTHWEST - AND NORTHWEST AT 25 TO 30 MPH
IN CENTRAL NORTH DAKOTA. BLOWING SNOW MAY BE AN ISSUE WEDNESDAY
AFTERNOON FROM THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER BASIN.
WITH THE EXCEPTION OF THE BRIEF WARM-UP ON WEDNESDAY...TEMPERATURES
WILL REMAIN WELL BELOW NORMAL THROUGH THE PERIOD AS A LARGE UPPER
TROUGH CONTINUES TO PROVIDE A STEADY STREAM OF ARCTIC AIR INTO NORTH
DAKOTA. CONSIDERING WINDS AND OVERNIGHT/EARLY MORNING
TEMPERATURES...SATURDAY MORNING AND SUNDAY MORNING ARE STILL
FORECAST TO BE THE COLDEST PERIODS...WITH WIND CHILLS OF 40 BELOW OR
COLDER ACROSS THE NORTHERN COUNTIES. WIND CHILL HEADLINES WILL
LIKELY BE NEEDED OTHER DAYS AS WELL.
SNOW CHANCES THROUGH MOST OF THE PERIOD WILL BE LOW...WITH THE
EXCEPTION OF SATURDAY NIGHT IN THE FAR SOUTHWEST AND SOUTH
CENTRAL...WHERE SOME LIGHT AMOUNTS ARE POSSIBLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1245 AM CST TUE FEB 25 2014
EARLY MORNING SATELLITE IMAGERY SHOWS VFR CONDITIONS WITH MAINLY
CLEAR SKIES ACROSS THE TAF LOCATIONS. GENERALLY EXPECT VFR
CONDITIONS TO REMAIN IN PLACE...HOWEVER SCATTERED TO BROKEN
CLOUDS AROUND 3500 FT ACROSS SOUTHERN SASKATCHEWAN / MANITOBA WILL
MOVE INTO NORTHERN AERODROMES BY 12Z...WORKING THEIR WAY SOUTH
THROUGH THE MORNING. WILL SHOW THE CLOUDS PROGRESSION ACROSS THE
TAF LOCATIONS...WITH MAINLY CLEAR SKIES PREVAILING ONCE THEY EXIT.
WINDS SHOULD BE LIGHT THIS MORNING...BUT WILL BECOME MORE STEADY
FROM THE NORTHWEST AFTER SUNRISE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST /9 AM MST/ THIS MORNING FOR
NDZ001>005-009>013-018>023-025-033>037-040>048-050-051.
&&
$$
UPDATE...CK
SHORT TERM...JNS
LONG TERM...JV
AVIATION...CK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
352 AM EST TUE FEB 25 2014
.SYNOPSIS...
UPPER LEVEL DISTURBANCE CROSSES FIRST THING THIS MORNING. ARCTIC
FRONTS CROSS TONIGHT AND THURSDAY. WEAK LOW PRESSURE CROSSES ON
SATURDAY. A STRONGER LOW PRESSURE SYSTEM APPROACHES ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER LEVEL SYSTEM IMPACTING NRN PORTION OF THE AREA EARLY THIS
MORNING AS RR ENTRANCE REGION OF JET AND FRONTOGENETIC FORCING CROSS
IN THE BAROCLINIC ZONE AROUND 12Z. AREA RADAR SHOWED THAT
PRECIPITATION WAS NOT YET REACHING THE GROUND SAVE FOR THE HIGHER
TERRAIN OF NRN WV. THIS SHOULD CHANGE TOWARD DAWN AS LOW LEVELS
EVENTUALLY MOISTEN.
WITH THE DRY AIR AT THE START...AND THE FAST PACE OF THE MI AND
UPPER LEVEL SYSTEM...AMNTS WILL BE LIMITED...MAINTAINED PREVIOUS
FCST OF LESS THAN AN INCH NRN LOWLANDS...1-2 INCHES IN THE NRN WV
MOUNTAINS WHERE THE SNOW WAS ALREADY REACHING THE GROUND.
ARCTIC FRONT DRIVEN BY UPPER LEVEL S/W TROUGH AND A MUCH MORE STOUT
JET MAX...CROSSES TONIGHT. UPSLOPE SNOW WILL SET UP OVERNIGHT IN
THE COLD ADVECTION BEHIND THE FRONT. FRONTOGENETIC FORCING EARLY ON
MAY GENERATE AN AREA OF SNOW UPSTREAM THAT MOVES INTO SRN PORTIONS
OF THE FCST AREA FROM THE W. IF THE POTENTIAL FOR THIS FEATURE TO
PRODUCE ACCUMULATING SNOW INCREASES...THEN AN ADVISORY FOR SNOW MAY
BE NEEDED FOR THE SRN LOWLANDS. HWO MENTION CONTINUES. THX JKL AND
MRX FOR COORD ON THIS.
BLENDED IN MET FOR HIGHS TODAY AND BIAS CORRECTED MET FOR LOWS
TONIGHT...CONTINUING THE COLDER TREND. SLOWED FALL OF TEMPERATURES
TONIGHT UNTIL LATER AS THE FRONT GOES BY.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
TRANSITION TO A QUIETER...BUT MUCH COLDER PATTERN IN THE SHORT TERM.
INITIAL COLD FRONT PUSHING EAST THROUGH CWA AT BEGINNING OF
PERIOD...WITH LIGHT SNOW SHOWERS LINGERING...MAINLY ACROSS MOUNTAIN
ZONES FOR REMAINDER OF DAY WEDNESDAY...WITH ONLY LIGHT ADDITIONAL
ACCUMULATIONS EXPECTED. THIS WILL BE THE FIRST SHOT OF COLD
AIR...WITH 850MB TEMPS DIPPING TO AROUND -16C THURSDAY MORNING. MADE
LITTLE CHANGES TO PREVIOUS LOW TEMPERATURE FORECAST THURSDAY
MORNING...WHICH PLACES MANY LOWLAND COUNTIES IN THE LOWER
TEENS...AND SINGLE DIGITS TO BELOW ZERO ACROSS THE MOUNTAINS. A
SECONDARY FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA ON THURSDAY.
BULK OF PRECIPITATION WILL REMAIN TO THE NORTH OF THE CWA...ALTHOUGH
NORTHERN ZONES COULD SEE A FEW FLURRIES WITH PASSAGE. WITH FRONTAL
PASSAGE...MUCH COLDER AIR WILL MOVE INTO THE AREA...WITH 850MB TEMPS
DIPPING DOWN TO AROUND -22C. AS A RESULT...ELECTED TO LOWER
TEMPERATURES SIGNIFICANTLY FRIDAY MORNING FROM PREVIOUS
FORECAST...PLACING MANY MOUNTAINOUS LOCATIONS BELOW ZERO...WITH
SINGLE DIGITS ACROSS THE LOWLANDS...CONSIDERING COLDER AIR
MASS...ALONG WITH FAVORABLE RADIATIONAL COOLING CONDITIONS.
WITH THE COLDER AIR IN PLACE...NORTHERN MOUNTAIN ZONES MAY NEED WIND
CHILL HEADLINES BOTH THURSDAY AND FRIDAY MORNINGS. AT THIS
POINT...DOESNT APPEAR TO BE NECESSARY ACROSS LOWLANDS. WILL CONTINUE
TO HIGHLIGHT IN THE HWO.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE WILL BE IN CONTROL THURSDAY NIGHT INTO FRIDAY WITH DRY
AND COOL CONDITIONS.
MODELS BRING A MID LEVEL SHORTWAVE EMBEDDED IN THE SOUTHERN STREAM
FRIDAY NIGHT INTO SATURDAY. ADJUSTED CHANCE POPS ACROSS THE AREA
WITH THIS FEATURE. WITH THE GFS AND ECMWF SHOWING FREEZING LINE AT
H85 ACROSS AND SOUTH OF OUR CWA...WONT BE SURPRISED TO SEE PCPN
FALLING AS SNOW. THIS SHORTWAVE EXITS SATURDAY WITH LINGERING SNOW
SHOWERS OVER THE EASTERN MOUNTAINS THROUGH AT LEAST SATURDAY
AFTERNOON.
BROAD SURFACE HIGH PRESSURE BUILD FROM THE UPPER CENTRAL
PLAINS...SOUTHEAST ACROSS THE OH VALLEY INTO WV SATURDAY NIGHT INTO
SUNDAY. WITH ZONAL FLOW EXPECTED ALOFT...THE AREA SHOULD STAY
RELATIVELY DRY SATURDAY NIGHT INTO SUNDAY.
THE FORECAST CHALLENGE ARRIVE WITH THE NEXT LOW PRESSURE SYSTEM.
BOTH THE GFS AND ECMWF BRING A SURFACE LOW PRESSURE CROSSING OUR CWA
DIAGONALLY FROM SOUTHWEST TO NORTHEAST SUNDAY OR MONDAY. THE PROBLEM
IS THAT THE ECMWF IS ABOUT 24 HOURS FASTER THAN THE GFS. TRIED TO
COMPROMISE IN BETWEEN BOTH SOLUTION IN TERMS OF POPS. EITHER
WAY...STRONG SOUTHWEST FLOW IS EXPECTED AHEAD OF THE LOW TO BRING
WARM AIR ADVECTION AND STRONG GUSTY WINDS. BOTH MODELS INDICATE 60
TO 70 KNOTS AT H85. AS MANY SPRING LOW SYSTEMS BRINGING STRONG
SOUTHWEST FLOW...EXPECT WARMER THAN GUIDANCE TEMPERATURES WITH THIS
SYSTEM. WENT WITH HPC WHICH IS WARMER THAN ALL AVAILABLE GUIDANCE
WITH THIS LOW. IN TERMS OF POPS...LEANED TOWARDS THE GFS SLOWER
SOLUTION AND INTRODUCED LIKELY POPS ON MONDAY.
TWEAKED HPC GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
AN UPPER LEVEL SYSTEM WILL BRING SNOW FROM THE MIDDLE OHIO VALLEY
EWD TO THE NORTHERN WV MOUNTAINS...AFFECTING THE NORTHERN 3 TAF
SITES EARLY TUE MORNING. SNOW IS LIKELY TO BRING IFR VSBY BEGINNING
NEAR 12Z TUE...A LITTLE EARLIER PKB AND A LITTLE LATER EKN. EXPECT
3-4 HOURS OF IFR VSBY IN SNOW...EXCEPT UP TO 6 HRS EKN...IMPROVING
TO MVFR AROUND 18Z TUE THERE. EXPECT MAINLY MVFR CIGS ALTHOUGH
BRIEF IFR CIGS ARE POSSIBLE. FARTHER S...EXPECT VFR WITH STRATOCU
4-5 KFT.
RETURN TO VFR N SHOULD BE AROUND MIDDAY...EXCEPT EKN...WHERE
IMPROVEMENT TO VFR VSBY TAKES UNTIL AROUND 20Z TUE...MVFR STRATOCU
MAY HANG ON THERE THROUGHOUT THE TAF PERIOD. FARTHER S...STRATOCU
VANISHES LATER TUE AFTERNOON BUT RETURNS LATE TUE NT...AS AN ARCTIC
FRONT ARRIVES FROM THE NW.
LIGHT W TO NW SFC FLOW BECOMES A BIT GUSTY DURING THE DAY
TUE...BEFORE DIMINISHING A BIT TUE NT. LIGHT TO MODERATE W FLOW
ALOFT BECOMES LIGHT W TUE AFTERNOON...AND THEN BEGINS TO STRENGTHEN
FROM THE NW LATE TUE NT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM HIGH.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF LIGHT SNOW AND ASSOCIATED
CATEGORY CHANGES MAY VARY. IFR CIGS COULD NOT BE RULED OUT N TUE
MORNING. EKN CIGS MAY IMPROVE TO VFR FOR A TIME TUE EVENING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 02/25/14
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY H H H H H H H M M M H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY H H H H H M M M M M M M
PKB CONSISTENCY H H H L L M M M M M M H
CKB CONSISTENCY H H H H H M M M M M M L
AFTER 06Z WEDNESDAY...
BRIEF IFR POSSIBLE OVERNIGHT TUESDAY NIGHT INTO EARLY WEDNESDAY IN
SNOW ASSOCIATED WITH AN ARCTIC FRONT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM
SHORT TERM...SL
LONG TERM...ARJ
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1113 PM CST MON FEB 24 2014
.DISCUSSION...
UPDATED FOR 06Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 923 PM CST MON FEB 24 2014/
UPDATE...
CLOUDS HAVE DEVELOPED QUICKLY OVER ARKANSAS THIS EVENING AS WARM
AIR IS OVERRUNNING THE COLDER AIR AT THE SFC. THE CLOUDS HAVE
PUSHED EAST AND NOW COVER MUCH OF THE MIDSOUTH. THE WEAK OVERRUNNING
PATTERN WILL PRODUCE AREAS OF LIGHT RAIN OVER MAINLY NORTH
MISSISSIPPI OVERNIGHT. TEMPERATURES HAVE EITHER HELD STEADY OR
HAVE GONE UP A COUPLE OF DEGREES SINCE THE CLOUDS HAVE PUSHED IN.
WILL UPDATE TO REMOVE MENTION OF SNOW AS TEMPERATURES WILL REMAIN
WELL ABOVE FREEZING AT AND ABOVE THE SFC TO KEEP PRECIPITATION
RAIN. WILL ALSO ADJUST SKY CONDITIONS TO CLOUDY. WILL KEEP 20 POPS
FROM MEMPHIS SOUTHWARD BUT LATEST HRRR INDICATES THAT MORE
DEVELOPMENT COULD OCCUR THAN OTHER MODELS ARE SUGGESTING. IF IT
PANS OUT THEN HIGHER POPS MAY BE NEEDED. WILL CONTINUE TO MONITOR
AND FUTURE UPDATES MAY BE NEEDED.
KRM
DISCUSSION... /ISSUED 329 PM CST MON FEB 24 2014/
TEMPERATURES ACROSS THE MIDSOUTH RANGE FROM THE MIDDLE 40S TO
MIDDLE 50S AROUND 10 TO 15 DEGREES COOLER THAN THEY WERE AT THIS
TIME YESTERDAY. MOST OF THE MIDSOUTH HAS SEEN ABUNDANT SUNSHINE
DURING THE DAY TODAY...BUT HIGH CLOUDS ARE NOW OVERSPREADING NORTH
MISSISSIPPI. SKIES WILL TURN MOSTLY CLOUDY ACROSS MOST OF THE
REGION OVERNIGHT KEEPING TEMPERATURES FROM COOLING QUITE AS MUCH
AS LAST NIGHT. MORNING LOWS TOMORROW WILL BE IN THE 30S ACROSS
MOST OF THE REGION...AND ABOVE FREEZING FOR THE SOUTHERN HALF OF
THE FORECAST AREA INCLUDING THE MEMPHIS METRO AREA.
TOMORROW...SURFACE WINDS WILL SHIFT MORE EASTERLY WITH WEST TO
NORTHWEST FLOW SETTING UP ALOFT. A STRONG MID LEVEL DISTURBANCE
WILL TRACK FROM NORTH TEXAS ACROSS ARKANSAS INTO NORTH MISSISSIPPI
LATE TOMORROW THROUGH EARLY WEDNESDAY. THERE IS SOME QUESTION
REGARDING HOW MUCH MOISTURE WILL STILL BE AVAILABLE LATE TUESDAY
NIGHT WHEN SUBFREEZING TEMPERATURES ARRIVE...ESPECIALLY IN WEST
TENNESSEE...THE MISSOURI BOOTHEEL AND NORTHEAST ARKANSAS FOR
FROZEN PRECIPITATION...BUT AT LEAST A BRIEF PERIOD OF SNOW OR A
RAIN SNOW MIX LOOKS POSSIBLE AREA WIDE. THE BEST CHANCE OF
ACCUMULATING SNOW LOOKS TO BE ACROSS NORTH MISSISSIPPI...BUT HERE
TEMPERATURES COLD ENOUGH FOR SNOW WILL NOT LIKELY ARRIVE UNTIL
WELL AFTER MIDNIGHT...OR EVEN UNTIL AROUND SUNRISE. DO NOT
ANTICIPATE THE NEED FOR ANY WINTER STORM
WARNINGS/WATCHES/ADVISORIES AT THIS TIME. HPC WINTER WEATHER
PRODUCTS DO NOT INCLUDE ANY FREEZING OR FROZEN PRECIPITATION.
MODELS LIQUID EQUIVALENT PRECIPITATION IS GENERALLY ONE TENTH OF
AN INCH OR LESS WHICH SHOULD NOT TRANSLATE TO MORE THAN A DUSTING
OF SNOW...AND THAT IS IN A BEST CASE SCENARIO WHERE ALL
PRECIPITATION FALLS AS SNOW AND IT DOES NOT MELT.
SURFACE HIGH PRESSURE WILL BUILD IN QUICKLY ON WEDNESDAY.
CONSIDERABLE SUNSHINE IS LIKELY BY THE EARLY AFTERNOON HOURS...BUT
NORTHERLY WIND WILL CURB AFTERNOON HIGHS KEEPING ALL OF THE
MIDSOUTH IN THE 30S...AND THE COLDEST LOCATIONS BELOW FREEZING.
THURSDAY WILL BEGIN VERY COLD WITH TEMPERATURES GENERALLY BETWEEN
15 AND 25 DEGREES BUT WARM INTO THE MID TO UPPER 40S DURING THE
AFTERNOON.
ANOTHER CHANCE OF PRECIPITATION WILL MOVE IN FRIDAY...GUIDANCE
SUGGESTS MULTIPLE PHASE CHANGES BETWEEN RAIN AND SNOW...OR A MIX
OF THE TWO AS TEMPERATURES WARM DURING THE DAY AND THEN COOL OFF
AGAIN FRIDAY NIGHT. THE OVERALL PATTERN LOOKS FAIRLY GOOD FOR A
MIDSOUTH SNOWFALL. A SURFACE LOW WILL TRACK FROM NORTH TEXAS
ACROSS CENTRAL ARKANSAS...BUT AT THIS TIME THICKNESSES DO NOT
SUPPORT ALL SNOW AND ACTUALLY RISE BY 30 METERS OR SO FROM MIDDAY
FRIDAY THROUGH MIDNIGHT. THE ECMWF SOLUTION IS EVEN WARMER THAN
THE GFS AND WOULD RESULT IN ALL RAIN.
SATURDAY LOOKS DRY WITH HIGHS RANGING FROM THE UPPER 30S TO UPPER
40S ACROSS MOST OF THE REGION. YET ANOTHER BRIEF CHANCE OF SNOW IS
IN THE FORECAST EARLY SUNDAY..MAINLY ACROSS NORTHERN...AREAS IF
MOISTURE ARRIVES BEFORE TEMPERATURES WARM. HIGHS SUNDAY SHOULD BE
WELL ABOVE FREEZING SO ANY SNOW THAT DOES FALL WILL MELT QUICKLY.
EARLY NEXT WEEK LOOKS WARMER AND RAINY.
&&
.AVIATION...
06Z TAF CYCLE
A DECK OF STRATOCU WILL CONTINUE ACROSS THE MIDSOUTH OVERNIGHT.
EXPECT CIGS TO REMAIN VFR IN THE 3500-4500FT RANGE OVERNIGHT WITH
A FEW SHRAS AT KMEM AND KTUP. THERE IS SOME RISK OF MVFR CIGS AT
KMEM LATER TONIGHT BUT NOT CONFIDENT ENOUGH TO MENTION IN TAFS
ATTM. AS DRY AIR MOVES IN FROM THE NORTH ON TUESDAY CLOUDS WILL
CLEAR OUT OF KJBR AND KMKL WHILE REMAINING AT KMEM AND KTUP.
WINDS WILL GENERALLY BE NE AT 5 KTS OVERNIGHT INCREASING TO 8-10
KTS TUESDAY...AND TO 10-14 KTS TUESDAY EVENING.
SJM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 40 54 29 36 / 20 10 60 10
MKL 34 50 24 32 / 10 10 40 0
JBR 34 49 25 34 / 10 10 40 0
TUP 40 57 32 39 / 20 10 60 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
316 AM CST TUE FEB 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CST TUE FEB 25 2014
MAIN FORECAST CONCERNS THIS PACKAGE...COLD TEMPERATURES AND NEED FOR
WIND CHILL HEADLINES TONIGHT.
DATA ANALYSIS AT 06Z HAD COLD...CANADIAN HIGH PRESSURE OVER THE
DAKOTAS WITH RIDGING ACROSS IA/IL. WV IMAGERY SHOWED THE SHORTWAVE
NEAR A KDLH-KDBQ LINE MOVING QUICKLY EAST ACROSS THE UPPER MIDWEST.
AREA RADARS SHOWING THE -SN WEST OF THIS LINE DISSIPATING/ENDING
RATHER QUICKLY EARLY THIS MORNING. TEMPS ACROSS THE AREA AS OF 06Z
MOSTLY IN THE ZERO TO 10F ABOVE RANGE. CLEARING SKIES BEHIND THE
SHORTWAVE ALREADY SPREADING INTO SOUTHWEST MN AND KMSP AREA...WITH
TEMPS FALLING TO ZERO TO -10F RANGE AND WIND CHILLS -15 TO -30.
25.00Z MODELS INITIALIZED QUITE WELL AND OFFER SIMILAR SOLUTIONS FOR
TODAY AND TONIGHT AS THE NEXT ONE DROPS ACROSS THE REGION THIS
AFTERNOON/EVENING. TREND FAVORS A TIGHTENING COMPROMISE CONSENSUS
ON THE TIMING/ STRENGTH OF THESE FEATURES. CHECK OF OBS VS. MODEL
DATA AT 06Z SHOWED MODELS TO BE GOOD WITH THE -SN MOVING/
DISSIPATING ACROSS THE AREA EARLY THIS MORNING. PER WV IMAGERY
MODELS APPEARED GOOD WITH THE SHORTWAVE DETAILS OVER NOAM/EASTERN
PAC...WITH NO ONE MODEL LOOKING BETTER THAN THE OTHERS. MODEL 850MB
RH PROGS DOING A DECENT JOB WITH THE DECREASING CLOUDS SPREADING
SOUTHEAST ACROSS MN EARLY THIS MORNING...WHILE ALL MODELS WERE TOO
ROBUST WITH THE POST- TROUGH 925MB MOISTURE ACROSS MUCH OF MN/
NEARBY AREAS. GIVEN THE TIGHT CONSENSUS...FAVORED A MODEL/ENSEMBLE
BLEND WITH SHORT-TERM FCST CONFIDENCE ON THE GOOD SIDE.
FOR THE SHORT TERM...ROUNDS OF LOW LEVEL COLD ADVECTION WILL SPREAD
ACROSS THE AREA THIS MORNING BEHIND DEPARTING WAVE NUMBER ONE AND
THIS EVENING BEHIND WAVE/TROUGH NUMBER TWO. FOLLOWING SO CLOSELY
BEHIND THE STRONGER WAVE FROM EARLY THIS MORNING...THE SECOND
SHORTWAVE HAS LIMITED MOISTURE ABOVE 850MB TO WORK WITH AND
TODAY/TONIGHT CONTINUE TO TREND DRY. SOME STEEPER LOW LEVEL LAPSE
RATES WITH MIXING TO 900-875MB INDICATED FOR THIS AFTERNOON...ALONG
WITH SOME 925MB MOISTURE. SCT STRATO-CU EXPECTED ACROSS THE AREA FOR
THE MID/LATE AFTERNOON HOURS. SOME STRONGER WINDS ACROSS MUCH OF THE
AREA FOR THIS AFTERNOON WITH A TIGHTER PRESSURE GRADIENT AND THE
DEEPER MIXING. CONTINUED THE MENTION OF SOME BLOWING/DRIFTING SNOW
ESPECIALLY ACROSS THE OPEN AREAS OF SOUTHEAST MN/NORTHEAST IA.
LOW TEMPS TRICKY TONIGHT. COLDEST OF THE LOW LEVEL AIR MOVES
ACROSS THE FCST AREA AROUND 06Z WITH 925MB TEMPS IN THE -21C TO
-23C RANGE...WITH LOW LEVEL WARM ADVECTION SPREADING INTO THE AREA
BY 12Z. MDT GRADIENT WINDS OF 10-15MPH LOOK TO REMAIN OVER THE
THRU MIDNIGHT...ONLY DIMINISHING LATE AS A WEAK SFC RIDGE AXIS
SLIDES ACROSS THE AREA. MIXED 925MB TEMPS WOULD ONLY SUPPORT LOWS
IN THE ZERO TO -10F RANGE...BUT WITH MOSTLY CLEAR SKIES AND
POTENTIAL FOR SOME DECOUPLING LATE...LEFT LOWS MOSTLY IN THE -10F
TO -15F RANGE. SUB ZERO TEMPS COMBINED WITH THE WINDS OF 10-15MPH
PRODUCE WIDESPREAD WIND CHILLS IN THE -20 TO -35 RANGE LATE THIS
EVENING THRU MUCH OF WED MORNING THUS WILL BE ISSUED A WIND CHILL
ADVISORY FOR 03Z TO 17Z WED. USED THE BLEND OF GUIDANCE HIGHS/LOWS
FOR TODAY/TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 315 AM CST TUE FEB 25 2014
MAIN FORECAST CONCERNS FOR WEDNESDAY THROUGH THURSDAY NIGHT...
CONTINUED COLD TEMPERATURES...-SN CHANCES WED AFTERNOON/EVENING.
MODEL RUNS OF 25.00Z REMAIN IN RATHER GOOD AND IMPROVING AGREEMENT
FOR THE WED THRU THU NIGHT PERIOD. TREND IS STRONGER WITH A
SHORTWAVE TROUGH TO DROP ACROSS THE GREAT LAKES WED AFTERNOON/NIGHT
AND DRIVE ANOTHER ARCTIC FRONT SOUTH ACROSS THE REGION. GIVEN THE
TIGHT AND TIGHTENING MODEL CONSENSUS...FCST CONFIDENCE IN THE WED
THRU THU NIGHT PERIOD IS GOOD.
THIS NEXT STRONGER SHORTWAVE TROUGH DROPS SOUTH TOWARD LK SUPERIOR
WED WITH FALLING SFC PRESSURES AND A TIGHTENING PRESSURE GRADIENT AS
THE SFC TROUGH WITH THE SHORTWAVE MOVES SOUTH INTO THE REGION.
RATHER STRONG 925-850MB WARM ADVECTION SPREADS ACROSS THE FCST
AREA WED WITH 925MB TEMPS WARMING INTO THE -10C TO -14C RANGE BY
LATE AFTERNOON. TIGHTER PRESSURE GRADIENT LOOKS TO RESULT IN WEST
TO SOUTHWEST WINDS OF 15-30MPH AND GUSTY FOR THE
AFTERNOON...RESULTING IN WHAT SHOULD BE GOOD MIXING AND A DIURNAL
TEMP RISE OF AS MUCH AS 30F OR MORE AT SOME LOCATIONS. ENOUGH WIND
FOR BLOWING/DRIFTING SNOW AGAIN IN THE OPEN COUNTRY AREAS WED
AFTERNOON/EVENING. WITH DITCHES ALREADY FULL OF DRIFTED
SNOW...SOME ROADS LIKELY TO BE IMPACTED BY ANY DRIFTING WED
AFTERNOON. WIND CHILLS WILL REMAIN IN THE -20 TO -35 RANGE MUCH OF
THE MORNING WITH THE TEMP RISE BEING OFFSET BY THE INCREASING
WINDS. WIND CHILLS DONT LOOK TO RISE ABOVE -20 UNTIL TEMPS WARM TO
AROUND +5F. SOME INCREASE OF 925-700MB MOISTURE INDICATED WITH
APPROACH/PASSING OF THE LOWER LEVEL TROUGH/FRONT WED
AFTERNOON/EVENING. MORE SATURATION INDICATED IN THE COOLER COLUMN
OVER THE NORTHEAST END OF THE FCST AREA AND INCLUDED A SMALL -SN/
FLURRY CHANCE THOSE AREAS WED AFTERNOON/EVENING. ARCTIC AIR SURGES
BACK INTO THE AREA WED NIGHT BEHIND THIS TROUGH/FRONT WITH 925MB
TEMPS BACK IN THE -24C TO -28C RANGE BY 12Z THU. GRADIENT WINDS IN
THE 10-20MPH RANGE WED NIGHT...TO KEEP THE BOUNDARY LAYER MIXED
AND LOWS FROM BOTTOMING OUT TOO FAR...BUT SENDS WIND CHILLS BACK
INTO THE -20 TO -35 RANGE BY 12Z THU WITH ANOTHER WIND CHILL
ADVISORY NEEDED LATE WED NIGHT/THU MORNING.
LOW LEVEL COLD ADVECTION CONTINUES THU WITH LITTLE DIURNAL TEMP
RECOVERY. MIXED 925MB TEMPS ONLY SUPPORT MOST HIGHS IN THE ZERO TO
+5F RANGE THU. CENTER OF THE ARCTIC HIGH SETTLES ACROSS THE AREA THU
NIGHT. SOME 850MB WARM ADVECTION PROGGED TO SPREAD IN LATE THU
NIGHT...BUT STRONG RADIATIONAL COOLING EXPECTED WED NIGHT WITH A
DECOUPLED BOUNDARY LAYER AND CLEAR/MOSTLY CLEAR SKIES AND THE ARCTIC
AIRMASS OVER THE AREA. SOME LOWS IN THE NORMALLY COLDER SHELTERED
LOCATIONS OF CENTRAL/NORTH CENTRAL WI COULD APPROACH -30F. SOME
INCREASE OF CLOUDS WEST OF THE MS RIVER LATE THU NIGHT MAY KEEP LOWS
A BIT WARMER THERE. ALL IN ALL...FAVORED A BLEND OF THE GUIDANCE
HIGHS/LOWS FOR WED THRU THU NIGHT BUT DID TREND TOWARD COLDER OF
GUIDANCE LOWS THU NIGHT ALONG/NORTHEAST OF I-94.
FOR FRIDAY THROUGH MONDAY.../DAYS 4 TO 7/...
MAIN FORECAST CONCERNS THIS PERIOD...SNOW CHANCES FRI/SUN/MON...
COLD TEMPERATURES THRU THE PERIOD.
MEDIUM RANGE MODEL RUNS OF 25.00Z IN SURPRISINGLY GOOD AGREEMENT FRI
INTO SAT NIGHT AS THE PATTERN TRANSITIONS TO MORE WESTERLY THRU SAT
THEN TOWARD SOUTHWESTERLY OVER THE CENTRAL CONUS SAT NIGHT. MODEL
DIFFERENCES INCREASE THRU SUN/MON WITH STRENGTH/TIMING OF SHORTWAVE
TROUGHS THRU THE FLOW AND ACROSS THE CENTRAL CONUS. RUN-TO-RUN
CONSISTENCY ON THE LOWER SIDE BY SUN/MON SO NO ONE MODEL LOOKS
FAVORED OVER THE OTHERS. SIDED WITH THE MODEL/ENSEMBLE CONSENSUS...
WITH FCST CONFIDENCE IN -SN CHANCES AVERAGE FRI/SAT THEN BELOW
AVERAGE SUN/MON. CONFIDENCE IS GOOD FOR TEMPS TO REMAIN BELOW NORMAL.
AN INCREASE OF MOISTURE...FROM THE SYSTEM THAT COMES INTO CA WED/WED
NIGHT...ACCOMPANIES THE LOWER LEVEL WARM ADVECTION THAT SPREADS
ACROSS THE AREA FRI...MORE ROBUST IN THE GFS/CAN-GEM SOLUTIONS. 20-
35 PERCENT -SN CHANCES ACROSS MAINLY THE SOUTH HALF OF THE FCST AREA
ON FRI LOOK REASONABLE. SOME MOISTURE FROM THE SYSTEM THAT CRASHES
ONSHORE INTO CA FRI/FRI NIGHT LOOKS TO OVERRUN THE COLD DOME OVER
THE AREA ALREADY FRI AFTERNOON/NIGHT. SMALL -SN CHANCES THESE
PERIODS ALSO REASONABLE FOR NOW PENDING A BETTER CONSENSUS ON WHAT
ARE DAY 5 DETAILS. BY DAYS 6/7 MODEL DIFFERENCES WOULD HAVE LARGE
IMPACTS ON THE SENSIBLE WEATHER. FASTER ECMWF WOULD LIMIT -SN
CHANCES TO SUN WITH ARCTIC HIGH PRESSURE BUILDING BACK IN FOR MON.
SLOWER GFS WOULD KEEP -SN IN THE FCST BOTH SUN/MON...WITH SOME
MODERATION OF TEMPS THESE PERIODS. AGAIN WITH NO ONE MODEL FAVORITE
AND LOWER CONFIDENCE BY SUN/MON STAYED WITH THE MODEL/ENSEMBLE
CONSENSUS FOR BOTH TEMPS AND -SN CHANCES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1136 PM CST MON FEB 24 2014
THE LIGHT SNOW WITH THE SHORT WAVE TROUGH HAS BEEN HOLDING TOGETHER
THIS EVENING AND MAKING STEADY EASTWARD PROGRESS. THE VISIBILITY IN
THE SNOW BRIEFLY DROPS DOWN TO MVFR FOR A COUPLE OF HOURS WHILE THE
CEILINGS ARE A LITTLE MORE VARIABLE...EITHER STAYING VFR OR ALSO
DIPPING TO MVFR. WILL SHOW THE SNOW MOVING OUT OF KRST SHORTLY AFTER
06Z AND AROUND 08Z AT KLSE WHICH IS VERY SIMILAR TO THE TRENDS OF
THE LATEST COUPLE RUNS OF THE HRRR WHICH SEEMS TO HAVE A PRETTY GOOD
HANDLE ON THE SNOW. IR SATELLITE SHOWS THE BACK EDGE OF THE CLOUDS
ALREADY ABOUT HALF TO THREE QUARTERS OF THE WAY ACROSS MINNESOTA.
WILL SHOW THE CLOUDS CLEARING OUT OF KRST BEFORE 12Z AND JUST AFTER
AT KLSE...BUT CONCERNED THAT THESE TRENDS COULD BE TOO SLOW. ONCE
THE CLOUDS CLEAR OUT...VFR CONDITIONS FOR THE REST OF THE PERIOD
WITH NORTHWEST WINDS BETWEEN 10 AND 15 KNOTS AS HIGH PRESSURE SLIDES
SOUTHEAST FROM THE CANADIAN ROCKIES INTO THE MIDWEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM 8 PM THIS EVENING TO 11 AM CST
WEDNESDAY FOR WIZ017-029-032>034-041>044-053>055-061.
MN...WIND CHILL ADVISORY FROM 8 PM THIS EVENING TO 11 AM CST
WEDNESDAY FOR MNZ079-086>088-094>096.
IA...WIND CHILL ADVISORY FROM 8 PM THIS EVENING TO 11 AM CST
WEDNESDAY FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1136 PM CST MON FEB 24 2014
.SHORT TERM...(TONIGHT AND TUESDAY)
ISSUED AT 215 PM CST MON FEB 24 2014
WATERVAPOR SATELLITE IMAGERY DEPICTING A SHORTWAVE TRACKING
SOUTHEAST OVER THE NORTHERN PLAINS. A BAND OF SNOW EXTENDS FROM THE
PLAINS INTO WESTERN IA...FOCUSED ALONG A REGION OF LOW LEVEL
FRONTOGENETICS. HRRR/RAP13/NAM12 KEEP THE MAIN BODY OF SNOW ON A
SOUTHEAST TRACK...ACROSS WESTERN/SOUTHERN IA. SOME LIGHT SNOW
ASSOCIATED WITH THE SHORTWAVE OVER SD THOUGH...AND EXPECT THIS TO
WORK OVER THE FORECAST AREA THIS EVENING...EXITING OVERNIGHT. COULD
BE SOME MINOR ACCUMS...GENERALLY LESS THAN 1/2 INCH...SOUTH OF I-90.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 215 PM CST MON FEB 24 2014
ARCTIC AIR WILL TAKE UP RESIDENCE ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY YET AGAIN...BRINGING BITTER TO DANGEROUSLY COLD TEMPERATURES.
ECMWF 850 MB TEMP ANOMALIES RUN FROM -2 TO -3 THROUGH THE WEEK.
AMPLIFIED UPPER LEVEL RIDGE OVER THE WEST COAST WILL GIVE ARCTIC AIR
EASY ACCESS SOUTH...AND ALSO PROVIDE AN AVENUE FOR VARIOUS BITS OF
UPPER LEVEL ENERGY. WITH A SFC HIGH EXPECTED TO BE OVERHEAD TUE/THU
NIGHTS...WED/FRI MORNINGS LOOK TO BE THE COLDEST OF THE WEEK. ANY
KIND OF STIRRING IN THE WINDS WILL MAKE IT FEEL 10 TO 15 DEGREES
COLDER. WIND CHILL ADVISORIES WILL BE NEEDED FOR WED/THU MORNING.
WINDS MUCH LESS FRI MORNING - SO SOME UNCERTAINTY FOR AN ADV THERE.
ANY WAY YOU LOOK AT IT...FEBRUARY IS GOING TO END ON A VERY COLD
NOTE.
THERE IS SOME HOPE BY THE END OF THE WEEKEND...AS UPPER LEVEL
TROUGHING IS EXPECTED TO PUSH INTO THE WEST COAST...WHICH WOULD HELP
BREAK DOWN THE RIDGE. OUR FLOW WOULD BECOME A BIT MORE ZONAL...
PUSHING THE VERY COLD AIR BACK NORTH. TEMPS WOULD MODERATE A
BIT...BUT STILL STAY BELOW NORMAL.
AS FOR PCPN CHANCES...GFS/ECMWF/NAM IN DECENT CONSENSUS WITH TAKING
PIECES OF SHORTWAVE ENERGY EITHER NORTH OR SOUTH OF THE HEART OF THE
FORECAST AREA. SOME GLANCING BLOWS ARE POSSIBLE...AND WITH
VARIABILITY IN THIS KIND OF FLOW...PLACEMENT AND TIMING OF ANY FEATURE
COULD CHANGE.
FIRST SHORTWAVE THAT COULD BRING SOME LIGHT SNOW COMES WED
NIGHT...WITH ALL THE MODELS DRIVING A TROUGH ACROSS THE NORTHERN
GREAT LAKES. GOOD AMOUNT OF QG CONVERGENCE IN THE 850-300 MB
LAYER...HOLDING MOSTLY ACROSS NORTHERN PORTIONS OF MN/WI. DECENT
SWATH OF LOW LEVEL WARM AIR ADVECTION SWEEPING AHEAD OF THE
ASSOCIATED COLD FRONT DURING THE DAY WED. ENOUGH DYNAMICS FOR
SNOW...BUT SATURATION IS GOING TO BE A LIMITING FACTOR. RH FIELDS
AND NORTHEAST-SOUTHWEST RUNNING X-SECTIONS SHOW A DEARTH OF
MOISTURE...EITHER CONFINED TO THE MID LEVELS...OR BELOW 850 MB. NOT
FAVORABLE FOR PCPN PRODUCTION. THAT SAID...LOCATIONS ALONG AND
NORTH/EAST OF I-94 SHOULD AT LEAST HAVE A SHOT FOR SOME LIGHT
SNOW/FLURRIES. ACCUMS WOULD BE MINIMAL.
BOTH MODELS WANT TO BRING A SHORTWAVE WEST-EAST OVER THE SOUTHERN
PLAINS FRI. NOT MUCH IMPACT FROM THIS FEATURE ITSELF...BUT WARM AIR
ADVECTION AND A DEFORMATION REGION NORTH OF THE WAVE COULD RESULT IN
SOME LIGHT SNOW FOR NORTHEAST IA/SOUTHERN WI. ANOTHER SHORTWAVE IS
SLATED TO DRIVE ACROSS IA SAT NIGHT/SUN...WHICH COULD BRING SOME
LIGHT SNOW TO AREAS SOUTH OF I-90. WILL SIDE WITH CONSENSUS POPS FOR
NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1136 PM CST MON FEB 24 2014
THE LIGHT SNOW WITH THE SHORT WAVE TROUGH HAS BEEN HOLDING
TOGETHER THIS EVENING AND MAKING STEADY EASTWARD PROGRESS. THE
VISIBILITY IN THE SNOW BRIEFLY DROPS DOWN TO MVFR FOR A COUPLE OF
HOURS WHILE THE CEILINGS ARE A LITTLE MORE VARIABLE...EITHER
STAYING VFR OR ALSO DIPPING TO MVFR. WILL SHOW THE SNOW MOVING OUT
OF KRST SHORTLY AFTER 06Z AND AROUND 08Z AT KLSE WHICH IS VERY
SIMILAR TO THE TRENDS OF THE LATEST COUPLE RUNS OF THE HRRR WHICH
SEEMS TO HAVE A PRETTY GOOD HANDLE ON THE SNOW. IR SATELLITE SHOWS
THE BACK EDGE OF THE CLOUDS ALREADY ABOUT HALF TO THREE QUARTERS
OF THE WAY ACROSS MINNESOTA. WILL SHOW THE CLOUDS CLEARING OUT OF
KRST BEFORE 12Z AND JUST AFTER AT KLSE...BUT CONCERNED THAT THESE
TRENDS COULD BE TOO SLOW. ONCE THE CLOUDS CLEAR OUT...VFR
CONDITIONS FOR THE REST OF THE PERIOD WITH NORTHWEST WINDS BETWEEN
10 AND 15 KNOTS AS HIGH PRESSURE SLIDES SOUTHEAST FROM THE
CANADIAN ROCKIES INTO THE MIDWEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1023 PM MST MON FEB 24 2014
.UPDATE...
ISSUED AT 714 PM MST MON FEB 24 2014
HAD TO DO AN UPDATE ON MIN TEMPERATURES THIS EVENING...ESPECIALLY
EAST OF THE LARAMIE RANGE. TEMPERATURES AT THE OFFICE HERE IN
CHEYENNE ALREADY AT 9 AND DROPPING WITH SINGLE DIGITS IN THE
PANHANDLE. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 345 PM MST MON FEB 24 2014
FRONT HAS PASSED ACROSS THE PLAINS WITH NORTHERLY WINDS AND LOW
CLOUDS FILLING IN BEHIND IT. THERE WAS A DRAMATIC DROP IN TEMPS
ALONG THE COLORADO BORDER WITH THE FROPA...AS PREFRONTAL
DOWNSLOPING WESTERLY WINDS WERE REPLACED BY THE COLD NORTHERLIES.
SOME LIGHT SNOW HAS BEEN REPORTED AT CHADRON OVER THE PAST FEW
HOURS WITH GENERALLY DEEPER LAYER LIFT STRETCHING FROM THE
NORTHERN PANHANDLE OFF TO THE NORTHEAST. COULD BE SOME LIGHT SNOW
SHOWERS ACROSS THE PLAINS OVERNIGHT WITH LLVL LIFT...BUT
ACCUMULATIONS WILL BE REALLY LIGHT. THE OTHER STORY THIS AFTN IS
THAT THE WINDS HAVE FINALLY WEAKENED ACROSS THE ARLINGTON AREA AND
LARAMIE VALLEY. STILL COULD BE SOME GUSTS TO 40-50 MPH THROUGH
SUNSET BUT WITH RAPID PRESSURE RISES TO THE EAST OF THE LARAMIE
RANGE AND THE 700MB CAG-CPR GRADIENT DROPPING TO 40 METERS BY 12Z
TUES...NOT EXPECTING THE STRONG WESTERLY WINDS TO RETURN TO THE
WIND PRONE AREAS THROUGH AT LEAST THE SHORT TERM.
THE MODELS STILL SHOW A SHORTWAVE DROPPING SOUTHEASTWARD FROM
MONTANA INTO NEBRASKA DURING THE DAY ON TUESDAY. THERE WILL BE
ABOUT A 6-HR PERIOD FROM LATE TUESDAY MORNING INTO THE AFTERNOON
THAT SNOW WILL BE LIKELY ACROSS THE CWA. THIS IS SHAPING UP TO BE
A WIDESPREAD LIGHT SNOWFALL EVENT...WITH MANY LOWER ELEVATION
LOCATIONS GETTING 1 TO 4 INCHES. THE SHORT DURATION OF THE EVENT
ALONG WITH WEAKER UPWARD MOTION THROUGH THE LOW AND MID LEVELS
(COMPARED TO THIS PAST WEEKEND EVENT) SHOULD KEEP MOST AREAS BELOW
ADVISORY LEVEL AMOUNTS. THE MTNS WILL GENERALLY SEE 5 TO 7 INCHES.
SNOW QUICKLY ENDS BY EVENING AS SUBSIDENCE KICKS IN BEHIND THE
SHORTWAVE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 345 PM MST MON FEB 24 2014
THE MEDIUM RANGE WILL BE CONSIST OF THE TALE OF TWO AIR MASSES. THE
FIRST AIR MASS WILL YIELD A RELATIVELY BENIGN PERIOD WEDNESDAY AND
THURSDAY AS NORTHWEST FLOW DRIES AND BECOMES LESS CYCLONIC. AT THE
SFC...THE QUASISTATIONARY BOUNDARY WILL RETREAT TO THE EAST BOTH OF
THESE DAYS AS WELL. SO ALTHOUGH SOMEWHAT BREEZY...EXPECT MOSTLY DRY
CONDITIONS TO PREVAIL FOR BOTH DAYS WITH HIGH TEMPERATURES GENERALLY
IN THE 40S OVR SE WY AND 30S OVR THE WRN NEBRASKA PANHANDLE.
THIS ALL WILL BEGIN TO CHANGE ON THURSDAY AS SHORTWAVE ENERGY DIVES
SOUTHEAST THRU THE FOUR CORNERS. MOISTURE ASSOCIATED WITH THIS FTR
WILL BRING A RETURN TO PRECIP CHANCES AREAS ALONG AND WEST OF THE
LARAMIE RANGE. ADDITIONALLY...SFC PRESSURE FALLS TO THE SOUTH
COMBINED WITH THE NEXT ARCTIC PINWHEELING AROUND THE HUDSON BAY LOW
WILL RESULT IN STRONG LLVL CAA AND RESULTANT FROPA. 12Z MODELS ARE
CONSISTENT IN FROPA TIMING OCCURRING FRIDAY MORNING. THIS COLD FRONT
WILL AGAIN PULL UP STATIONARY NR THE DIVIDE AS THE ARCTIC AIR MASS
HANGS UP ON THE TERRAIN. ALOFT...WEST/SOUTHWEST FLOW FILLED WITH
PACIFIC MOISTURE WILL PERSISTENTLY OVER-RUN THIS LLVL COLD DOME
SETTING THE STAGE FOR WHAT LOOKS TO BE A SNOWY PERIOD BEGINNING LATE
THURSDAY THROUGH SATURDAY NIGHT. DETAILS ARE STILL TOO BLURRY TO
START TALKING ABOUT ACCUMULATIONS JUST YET...BUT GIVEN THE EVENTS
LONG DURATION WOULD EXPECT MODERATE SNOW AMOUNTS AT A MINIMUM. HAVE
CONTINUED TO BOOST SNOW CHANCES DURING THIS PERIOD PRETTY MUCH
AREA-WIDE AS CONFIDENCE GROWS. THE OTHER IMPACT FROM FROPA WILL BE
THE VERY COLD AIR ASSOCIATED WITH THE ARCTIC AIR MASS. AREAS
NORTHEAST OF THE NORTH PLATTE RIVER VALLEY WILL ONLY REACH THE LOWER
20S ON FRIDAY AND SINGLE DIGITS ON SATURDAY AND SUNDAY.
THE PATTERN WILL BECOME LESS ACTIVE AND MORE ZONAL FOR LATE IN THE
WEEKEND AND EARLY NEXT WEEK. HOWEVER...DID KEEP SMALL SNOW CHANCES
GOING FOR THIS LATTER PERIODS AS THE MODELS ARE STILL MEANDERING
THAT BOUNDARY IN THE VICINITY OF THE FRONT RANGE. TEMPERATURES TRY
TO EVER SO SLOWLY WARM MONDAY...BUT WILL STILL REMAIN BELOW
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY EVENING)
ISSUED AT 1017 PM MST MON FEB 24 2014
TRICKY FORECAST CONTINUES OVERNIGHT. WINDS ARE PRETTY MUCH CALM
HERE AT KCYS WITH SOUTHEASTERLY WINDS JUST TO OUR SOUTH AND OVER
AT KLAR. SHOULD OUR WINDS TURN SOUTHEAST HERE AT KCYS...WE WILL GO
DOWN ONCE AGAIN IN UPSLOPING FLOW. HRRR KEEPS LOWER CEILINGS DOWN
ON THE COLORADO SIDE OF THE WYO HILL...BUT DO THINK THERE IS A
SMALL WINDOW WHERE KCYS COULD SEE A SOUTHEAST WIND FOR A TIME.
ADDED TEMPO IFR CONDITIONS HERE AT KCYS BASED ON THESE WINDS. SOME
MVFR OUT IN THE PANHANDLE NEAR CHADRON AND SIDNEY OVERNIGHT.
ATTENTION TURNS TO LOWERING CONDITIONS TUESDAY AS SNOW BECOMES
WIDESPREAD. BEING OBSERVED ON MOSAIC RADAR RIGHT NOW OVER
SOUTHWESTERN MONTANA AND NORTHWESTERN WYOMING. THIS IS FROM A
DISTURBANCE THAT WILL RIDE DOWN ALONG THE FRONT TO OUR WEST. DO
THINK MOST AIRPORTS WILL SEE A PERIOD OF IFR CONDITIONS TUESDAY
MID MORNING THROUGH THE AFTERNOON HOURS.
&&
.FIRE WEATHER...
ISSUED AT 345 PM MST MON FEB 24 2014
NO FIRE WEATHER CONCERNS THROUGH THE END OF THE WEEK. WIDESPREAD
SNOW COVER STILL EXISTS ACROSS MUCH OF THE NEBRASKA PANHANDLE.
ANOTHER ROUND OF SNOW IS EXPECTED TUESDAY MORNING THROUGH THE
EVENING. TEMPERATURES WILL GENERALLY BE BELOW NORMAL THROUGH THE
UPCOMING WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLAYCOMB
SHORT TERM...FINCH
LONG TERM...HAHN
AVIATION...CLAYCOMB
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1008 AM EST TUE FEB 25 2014
.SYNOPSIS...
UNSEASONABLY COLD WEATHER WILL CONTINUE RIGHT INTO THIS WEEKEND.
THERE WILL BE A FEW OPPORTUNITIES FOR SOME SNOW SHOWERS...BUT NO
MAJOR STORMS ARE EXPECTED THIS WEEK AND DRY WEATHER WILL DOMINATE.
A MORE SIGNIFICANT STORM MAY AFFECT OUR REGION BY THE LATE PORTION
OF THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
CLOUDS HAVE OVERSPREAD THE REGION THIS MORNING AND WILL PERSIST
THROUGH THE AFTERNOON GIVEN ABUNDANT 850 MB RH. MID LEVEL
SHORTWAVE AND SFC TROF MOVES THROUGH THIS AFTERNOON AND WILL
BRING A FEW SNOW SHOWERS/FLURRIES. HOWEVER...AREAL COVERAGE SHOULD
BE LIMITED AS LOWEST LEVELS ARE QUITE DRY WITH DEWPOINTS WELL DOWN
INTO THE SINGLE NUMBERS AND LOW LEVEL LAPSE RATES ARE NOT QUITE AS
ROBUST AS YESTERDAY. HRRR SHOWING JUST A FEW LIGHT SNOW SHOWERS
THIS AFTERNOON AND WILL SCALE POPS BACK TO ISOLD. MAX TEMPS WILL
BE MOSTLY IN THE 20S TO AROUND 30 IN THE COASTAL PLAIN.
PREVIOUS DISCUSSION...
25/00Z GUIDANCE SUITE IS IN GOOD AGREEMENT...SO SEE NO MAJOR
REASON TO DEVIATE MUCH FROM THE CONSENSUS PATTERN FOR TODAY.
ANOTHER FAST MOVING SHORTWAVE WILL BE MOVING THROUGH OUR REGION
LATER TODAY. THERE SHOULD BE ENOUGH LOW LEVEL MOISTURE FOR A
REPEAT OF DIURNAL STRATOCUMULUS CLOUDS DEVELOPING. WE STILL CANNOT
COMPLETELY RULE OUT A FEW INTERIOR FLURRIES/SNOW SHOWERS. THESE
WOULD BE MAINLY CONFINED CLOSE TO THE BERKSHIRES...WHERE THERE IS
SOME ADDITIONAL MOISTURE BEING PROVIDED FROM LAKE ONTARIO. DRY
AIR IN THE LOWEST LEVELS WILL BE A LIMITING FACTOR DESPITE STEEP
LOW LEVEL LAPSE RATES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT...A MORE AMPLIFIED NORTHERN STREAM SHORTWAVE WILL BE
APPROACHING FROM THE GREAT LAKES. WEAK RIDGING AHEAD OF THIS
FEATURE WILL RESULT IN MAINLY DRY CONDITIONS.
WEDNESDAY...THE MODELS ARE IN GENERAL AGREEMENT THAT LOW
PRESSURE EMERGING OFF THE MID ATLANTIC COAST WILL PASS WELL
SOUTHEAST OF THE BENCHMARK. THERE IS STILL A NORTHERN STREAM
SHORTWAVE...WHICH ALSO PRODUCES A WEAK SURFACE WAVE. THIS FEATURE
WILL HAVE LIMITED MOISTURE.
THIS SETS UP A BRIEF WINDOW WEDNESDAY MORNING INTO WEDNESDAY
AFTERNOON WHERE CONDITIONS ARE FAVORABLE ENOUGH WITHIN THE PRIME
SNOW GROWTH REGION TO GET DECENT SNOW ACCUMULATION. STILL THINKING
MOST OF SOUTHERN NEW ENGLAND WILL BE AN INCH OR LESS...WITH A FEW
SPOTS TOWARD CAPE COD AND THE ISLANDS SEEING UP TO 2 INCHES OR SO.
MANY OF THE SNOW SHOWERS WILL BE EXITING THE COAST BY MID TO LATE
AFTERNOON AS DRIER MID LEVEL AIR RUSHES INTO THE REGION.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
*/ HIGHLIGHTS...
- UNSEASONABLY COLD TEMPERATURES PREVAIL THROUGHOUT THE FORECAST
- LIGHT SNOW FOR THURSDAY UNDER BLUSTERY WINDS
- WIND CHILL ADVISORIES MAY BE NEEDED FOR FRIDAY MORNING
- ANOTHER SHOT OF LIGHT SNOW SATURDAY
- A MORE SIGNIFICANT STORM APPEARING LIKELY SUNDAY INTO MONDAY
*/ OVERVIEW AND MODEL PREFERENCE...
CONSIDERING THE PROXIMITY AND EVOLUTION OF THE POLAR LOW COMBINED
WITH WESTERN CONUS RIDGING...A PROGRESSIVE FLOW PATTERN IS FAVORED.
SOME UNCERTAINTY AS TO THE DOWNSTREAM RIDGE STRENGTH ASSOCIATED WITH
THE NORTH-CENTRAL ATLANTIC HIGH...YET ENSEMBLE MEMBERS IN GOOD
AGREEMENT OF A SLIGHTLY +NAO. ANTICIPATING AN ACTIVE WEATHER PATTERN
WITH TROUGHING PREFERRED OVER THE NE CONUS. GREATEST UNCERTAINTY
LIES IN INDIVIDUAL MORPHOLOGY OF DISTURBANCES AND SUBSEQUENT SURFACE
OUTCOMES. THOUGH A MODEL-WEIGHTED CONSENSUS BLEND APPROACH HAS BEEN
CONDUCTED WITH THIS FORECAST...WILL OUTLINE OVERALL CONFIDENCE IN
THE DISCUSSION BELOW.
*/ DAY-TO-DAY DETAILS...
WEDNESDAY NIGHT INTO THURSDAY NIGHT...
POLAR WAVE INVOKES A CLIPPER LOW ACROSS THE NORTHERN GREAT LAKES
INTO NORTHERN NEW ENGLAND. ATTENDANT ARCTIC FRONT IS THE FOCUS FOR
LIGHT SNOW ACTIVITY. CONSIDERING THE DISTURBANCE IS CUT-OFF FROM SUB-
TROPICAL MOISTURE AND IS MORE CONTINENTAL POLAR WITH REGARDS TO
AIRMASS...MAIN CONCERN IS UPON BLUSTERY WINDS AND ARCTIC AIR.
BOUNDARY LAYER MIXING POTENTIALLY ALL THE WAY TO H7 AHEAD OF THE
FRONT THURSDAY AND IMMEDIATELY IN WAKE OF THE FRONT BY THURSDAY
EVENING WILL ALLOW FOR THE MIX-DOWN OF 30 TO 40 MPH GUSTS AT THE
SURFACE /INITIALLY SOUTHWESTERLY TURNING WESTERLY BEHIND THE FRONT/.
COMBINING THIS ALONG WITH UNSEASONABLY COLD TEMPERATURES /H85 AROUND
-20C BY FRIDAY MORNING/ AND THERE IS MODERATE CONFIDENCE TOWARDS THE
ISSUANCE OF WIND CHILL ADVISORIES OVER THE NORTH AND WEST INTERIOR
HIGH TERRAIN /ESPECIALLY FOR THURSDAY NIGHT INTO FRIDAY MORNING/.
LOW CONFIDENCE TOWARDS THE NEED FOR WIND ADVISORIES...FEEL WIND
GUSTS WILL REMAIN BELOW THRESHOLDS. WINDS DIMINISH TOWARDS FRIDAY
MORNING.
LIKELY GALES OVER THE WATERS WITH THE NEED FOR FREEZING SPRAY
ADVISORIES WITH COLD OCEAN TEMPERATURES. HIGH CONFIDENCE. LOWS IN
THE SINGLE DIGITS WITH HIGHS IN THE LOW- TO MID-20S.
FRIDAY INTO FRIDAY NIGHT...
ARCTIC HIGH PRESSURE BUILDS OVER THE REGION WITH UNSEASONABLY COLD
AIR. WITH H85 TEMPERATURES AROUND -20C DURING THE DAY...EXPECTING
HIGHS AROUND THE UPPER-TEENS TO LOW 20S. POSSIBLE WIND CHILL
ADVISORIES FOR THE MORNING SHOULD DROP OFF AS SURFACE TEMPERATURES MODERATE
AND WINDS BECOME LIGHT AND VARIABLE.
WILL KEEP THE FORECAST PERIOD DRY. INCREASING CLOUDS LATE AHEAD OF
THE WEEKEND DISTURBANCE IN ADDITION TO SOUTHWEST FLOW ALOFT AND
MODERATING TEMPERATURE TREND WHICH WILL ALLOW FOR SLIGHTLY WARMER
OVERNIGHT LOWS.
SATURDAY INTO SATURDAY NIGHT...
WEAK PACIFIC WAVE DISTURBANCE ABLE TO TAP INTO GULF MOISTURE IS
SEEMINGLY DEAMPLIFIED UNDER THE WEIGHT OF A REINFORCING ARCTIC FRONT
AND ACCOMPANYING HIGH PRESSURE. NOT EXPECTING MUCH THREAT WITH THE
WEAK NATURE OF THE SYSTEM...SOME LIGHT SNOW POSSIBLE WITH THE
POTENTIAL OF OCEAN-EFFECT SNOWS IN WAKE OF THE ARCTIC FRONT...
OTHERWISE WILL SEE THE CONTINUANCE OF UNSEASONABLY COLD TEMPS.
SUNDAY AND BEYOND...
CONSIDERING ENSEMBLE MEANS...HAVE HIGH CONFIDENCE OF A LOW FROM THE
GULF COAST LIFTING NORTHWARD THROUGH THE OHIO RIVER VALLEY TOWARDS
THE SOUTH-COAST OF NEW ENGLAND. BUT VARIANCE AND SPREAD AMONG MODEL
SOLUTIONS IS STILL TOO HIGH TOWARDS KNOWING EXACT OUTCOMES. EVEN THE
DETERMINISTIC ECMWF HAS RUN-TO-RUN WOBBLES IN THE LOW TRACK AND
POSITION THAT MAKE FOR VARYING FORECASTS. WILL AWAIT BETTER MODEL
CONSENSUS BEFORE GOING ANY FURTHER ON THE DETAILS.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH WEDNESDAY/...
12Z UPDATE...
VFR. SCT-BKN CIGS 040-080 WITH GUSTY W/NW WINDS UP TO 30 KTS THE
STRONGEST OF WHICH WILL BE MID-MORNING INTO THIS EVENING. THERE IS
THE POTENTIAL FOR -SN AND HAVE GONE AHEAD WITH A TEMPO MENTION
ALONG WITH MVFR VSBYS. MAY BE GOING A BIT ABOVE AND BEYOND WITH
THIS MENTION. COULD POTENTIALLY SEE -SN...BUT HARDLY ANY VSBY
IMPACT SHOULD -SN BE JUST FLURRIES.
MODERATE CONFIDENCE WEDNESDAY...MAINLY DUE TO TIMING. A PERIOD OF
MVFR CIGS/VSBYS IS LIKELY DURING THE DAY IN SOME SNOW SHOWERS.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. MODERATE CONFIDENCE WITH
TEMPO -SN.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. MODERATE CONFIDENCE WITH
TEMPO -SN.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...MODERATE CONFIDENCE.
MVFR-IFR WITH -SN. SW WINDS GUSTING UP TO AROUND 35 KTS DURING THE
DAY THURSDAY...BACKING WESTERLY BY EVENING AND DIMINISHING TOWARDS
MORNING.
FRIDAY INTO FRIDAY NIGHT...MODERATE CONFIDENCE.
VFR. LIGHT AND VARIABLE WINDS. INCREASING MID- TO HIGH-CLOUDS LATE.
SATURDAY INTO SATURDAY NIGHT...MODERATE CONFIDENCE.
MVFR-IFR WITH -SN. BREEZY SOUTHWEST WINDS BACKING W/NW TOWARDS
EVENING.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH WEDNESDAY...HIGH CONFIDENCE.
GUSTY WEST TO NORTHWEST WINDS CONTINUES ACROSS THE COASTAL WATERS.
SMALL CRAFT ADVISORIES WILL CONTINUE. PRESSURE GRADIENT IS A
LITTLE WEAKER TODAY...SO WILL DROP THE ADVISORIES FOR BOSTON
HARBOR AND NARRAGANSETT BAY. A BIT OF A LULL EXPECTED THIS
MORNING ACROSS THE OTHER NEAR SHORE WATERS...BUT NOT ENOUGH OF ONE
TO DROP THE ADVISORY COMPLETELY. WOULD JUST HAVE TO REISSUE ONE
LATER THIS MORNING AND AFTERNOON AS WINDS PICK UP AGAIN.
WINDS WILL EVENTUALLY DIMINISH BELOW 25 KT TONIGHT...BEFORE
INCREASING AGAIN WEDNESDAY. ROUGH SEAS WILL BE SLOWER TO SUBSIDE
TONIGHT...ESPECIALLY ACROSS THE OUTER COASTAL WATERS. INCREASING
WINDS SHOULD RESULT IN BUILDING SEAS FOR WEDNESDAY...ESPECIALLY
TOWARDS THE OUTER WATERS. AREAS OF FREEZING SPRAY EXPECTED.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...HIGH CONFIDENCE.
SOUTHWEST GALES AHEAD OF A FRONT WITH WIND GUSTS UP TO 40 KTS...
CONTINUING WHILE BACKING WESTERLY WITH FRONTAL PASSAGE...GRADUALLY
DIMINISHING TOWARDS FRIDAY MORNING. COMBINED WITH SEAS AND COLD
OCEAN TEMPERATURES AND THERE IS THE LIKELY NEED FOR FREEZING SPRAY
ADVISORIES AS MODERATE FREEZING SPRAY IS ANTICIPATED. LIGHT SNOW
ALSO POSSIBLE WHICH MAY MAKE FOR VISIBILITY RESTRICTIONS ON THE
WATERS.
FRIDAY INTO FRIDAY NIGHT...MODERATE CONFIDENCE.
HIGH PRESSURE BUILDS OVER THE WATERS THROUGH THE DAY. BOTH THE
THREAT OF FREEZING SPRAY AND GALE-FORCE WINDS DROP TOWARDS MIDDAY.
SEAS ALLOWED TO DIMINISH. SMALL-CRAFT ADVISORIES LIKELY.
SATURDAY INTO SATURDAY NIGHT...MODERATE CONFIDENCE.
BREEZY SOUTHWEST FLOW TURNING W/NW WITH AN ARCTIC FRONTAL PASSAGE BY
EVENING. WINDS ARE ANTICIPATED TO REMAIN BELOW 25 KTS. SEAS LIKELY
TO AMPLIFY WITH FETCH. LIGHT SNOW ALSO POSSIBLE WHICH COULD MAKE FOR
VISIBILITY RESTRICTIONS ON THE WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR
ANZ230>237-251.
SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...BELK/KJC
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...BELK/SIPPRELL
MARINE...BELK/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1031 AM EST TUE FEB 25 2014
.UPDATE...FOG HAS LIFTED BUT AREAS OF LOW CLOUDS CONTINUE
ESPECIALLY OVER OUR SOUTHERN ZONES. THESE CLOUDS ARE ERODING FROM
THE EDGES AS SURFACE HEATING CONTINUES. MADE SOME TWEAKS TO THE
SKY COVER GRIDS.
WE CURRENTLY HAVE 20 PERCENT SHOWER CHANCES IN THE FORECAST FOR
THE AFTERNOON HOURS. LOOKING AT THE LATEST SUITE OF GLOBAL
MODELS...THE VAST MAJORITY OF SHOWERS WILL BE TO THE EAST OF OUR
FORECAST AREA...PERHAPS CLIPPING HIGHLANDS COUNTY. THE HRRR ON THE
OTHER HAND DEVELOPS SHOWERS ALONG THE CONVERGENT BOUNDARY
ASSOCIATED WITH THE DECAYED FRONT. THIS BOUNDARY IS MOVING
SOUTHEAST THROUGH HILLSBOROUGH COUNTY NOW...SO EVEN IF SHOWERS DO
DEVELOP...IT SHOULD STAY DRY TO THE NORTH. FOR THIS
UPDATE...REMOVED RAIN CHANCES FROM MANATEE COUNTY NORTHWARD ALONG
THE COAST BUT LEFT SLIGHT CHANCES IN FROM LEE AND CHARLOTTE
COUNTIES NORTHEAST ACROSS DESOTO AND HIGHLANDS.
THE GRIDDED FORECAST DATABASE HAS BEEN UPDATED. THE TEXT ZONE
FORECASTS WILL BE OUT SHORTLY.
&&
.AVIATION...
CONDITIONS CONTINUE TO IMPROVE FOR KTPA...KPIE...KLAL...AND KSRQ AND
GENERAL VFR CONDITIONS CAN BE ANTICIPATED FOR THE REST OF THE DAY
AND EVENING. IMPROVEMENT HAS BEEN SLOWER FURTHER SOUTH TOWARD KPGD
AND KRSW. EXPECT IFR/MVFR RESTRICTIONS FOR THESE TERMINALS TO LIFT
BY MIDDAY WITH VFR THEN PREVAILING THROUGH THE EVENING. AREAS OF
CIG/VIS RESTRICTIONS ARE EXPECTED TO REDEVELOP AFTER MIDNIGHT INTO
THE FIRST FEW DAYLIGHT HOURS OF WEDNESDAY.
&&
.MARINE...
SOME PATCHY SEA FOG MAY BE OCCURRING JUST OFFSHORE BUT DEW POINT
TEMPERATURES HAVE FALLEN BELOW THE SEA SURFACE TEMPERATURES.
CHANCES ARE THAT MUCH OF WHAT WE SEE ON SATELLITE IMAGERY IS
SITTING ABOVE THE SURFACE AS A LOW STRATUS LAYER. THE GENERAL
TREND HAS BEEN FOR DECREASING COVERAGE SO WILL NOT INCLUDE FOG IN
THE UPDATE.
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...JILLSON
AVIATION...MROCZKA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1001 AM EST TUE FEB 25 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BE OVER THE AREA THROUGH TODAY. A GULF
COAST LOW PRESSURE SYSTEM WILL MOVE EAST THROUGH GEORGIA AND
FLORIDA TONIGHT INTO WEDNESDAY BRINGING A CHANCE OF RAIN TO
OUR AREA. DRY AND COOLER WEATHER IS EXPECTED THURSDAY AND FRIDAY
WITH ANOTHER CHANCE OF RAIN EARLY SATURDAY WITH A FAST MOVING
SYSTEM.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK SURFACE HIGH PRESSURE REMAINS OVER THE AREA TODAY AS A
DE-AMPLIFYING SHORTWAVE TROUGH MOVES EASTWARD ACROSS THE TENNESSEE
VALLEY AND CROSSES THE FORECAST AREA LATER TODAY. RADAR SHOWING
CLUSTER OF SHOWERS OVER NORTH GEORGIA MOVING TOWARD THE PIEDMONT
AND CSRA. AIR MASS IS RELATIVELY DRY IN THE LOW LEVELS SO EXPECT
PRECIPITATION TO DIMINISH TO THE EAST. LATEST HRRR GUIDANCE HOWEVER
SUGGESTS A FEW SHOWERS WILL MOVE INTO THE PIEDMONT AND POSSIBLY
MIDLANDS LATER THIS MORNING...SO INCREASED POPS TO CHANCE/SLIGHT
CHANCE WEST OF CAE...QPF WILL BE LIGHT. TEMPERATURES WILL BE
SLIGHTLY COOLER THAN ON MONDAY DUE TO THE INCREASING CLOUDS...IN
THE 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
CHANCES OF RAIN INCREASE TONIGHT AS BROAD UPPER TROUGH SINKS
ACROSS THE GREAT LAKES AND OHIO VALLEY REGION DRIVING A COLD FRONT
THROUGH THE FORECAST AREA EARLY WEDNESDAY MORNING BEFORE HIGH
PRESSURE BUILDS IN AT THE SURFACE BEHIND THE FRONT WEDNESDAY
AFTERNOON. WESTERLY LOW LEVEL FLOW AHEAD OF THE SHORTWAVE AND
FRONT IS FORECAST TO BACK MORE SOUTHWESTERLY THIS EVENING ALLOWING
FOR ATMOSPHERIC MOISTURE TO INCREASE WITH FLOW OFF THE WESTERN
GULF OF MEXICO. HOWEVER...THE TIME FRAME FOR SIGNIFICANT MOISTURE
TO MOVE INTO THE REGION BEFORE THE FRONT ARRIVES IS SHORT AND A
LIMITING FACTOR DESPITE MODERATE UPPER DYNAMICS ARRIVING AROUND
THE 12Z TIME FRAME AS THE NORTHERN AND SOUTHERN STREAM JETS COUPLE
TO PROVIDE STRONG OMEGA AND UPWARD VERTICAL MOTION OVER THE
FORECAST AREA.
HAVE INCREASED POPS A BIT TO LOW LIKELY ACROSS THE SOUTHEASTERN
MIDLANDS AND CSRA FROM LATE TONIGHT INTO WEDNESDAY MORNING WITH A
GRADIENT TO LOWER POPS TO THE NORTHWEST WHERE MOISTURE WILL NOT BE
AS GREAT. STILL FIGURE THE BEST TIME FRAME FOR HIGHEST POPS WILL
BE FROM 09Z-15Z WITH CHANCES OF RAIN DECREASING FROM NORTHWEST TO
SOUTHEAST THROUGH THE DAY WEDNESDAY. TEMPERATURES WILL BE MUCH
COOLER WEDNESDAY COMPARED TO TUESDAY WITH COLD ADVECTION TAKING
PLACE DURING THE DAY DESPITE SOME CLEARING SKIES BY AFTERNOON.
COOL AND DRY SURFACE HIGH PRESSURE BUILDS OVER THE AREA WEDNESDAY
NIGHT INTO THURSDAY PROVIDING DRY WEATHER AND BELOW NORMAL
TEMPERATURES. LOWS WEDNESDAY NIGHT WILL BE QUITE COOL AND THE
COLDEST WE HAVE SEEN IN A COUPLE OF WEEK AS TEMPERATURES FALL INTO
THE 20S. HIGHS ON THURSDAY UNDER MOSTLY SUNNY SKIES WILL BE IN THE
MID TO UPPER 50S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MEDIUM RANGE GUIDANCE HAS REMAINED FAIRLY CONSISTENT SHOWING
ANOTHER FAST MOVING UPPER TROUGH CROSSING THE FORECAST AREA FRIDAY
NIGHT AND SATURDAY BRINGING ANOTHER CHANCE OF RAIN TO THE REGION.
THE TRACK OF THE SYSTEM AND ASSOCIATED MOISTURE APPEAR TO BE A BIT
FURTHER NORTH SO HAVE LOWERED POPS A BIT THIS PERIOD. MODEL TRENDS
OF A DEVELOPING STORM SYSTEM OVER THE PLAINS SUN/MON LEAD TO
SOUTHWESTERLY FLOW ALOFT OVER THE SOUTHEAST AND POSSIBLE WARM
ADVECTION IN THE LOWER LEVELS. HAVE TRENDED TEMPERATURES A BIT
WARMER ON THESE DAYS BUT IF TRENDS CONTINUE THESE TEMPERATURES MAY
NEED TO CONTINUE TO BE RAISED WARMER. HOWEVER THIS IS A LOW
CONFIDENCE FORECAST GIVEN PLENTY OF SPREAD IN THE ENSEMBLES AND
DIFFERENCES IN TIMING OF THE OPERATIONAL RUNS.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS STILL FORECAST THROUGH THE TAF PERIOD.
SCATTERED STRATO-CU AND MID LEVEL CLOUDS WILL SPREAD ACROSS THE
AREA THROUGH THE AFTERNOON. PATCHY LIGHT SHOWERS OVER THE UPSTATE
AND NORTH GEORGIA WILL WEAKEN AS THEY MOVE EAST INTO DRIER AIR
MASS. LATEST RAP AND NAM INDICATING BRIEF GUSTY WINDS WEST BEHIND
WEAK SHORT WAVE TROUGH THIS AFTERNOON.
INTO THE OVERNIGHT PERIOD...MODELS AND BUFKIT SOUNDINGS SHOWING
MOISTURE CONTINUING TO INCREASE IN THE MID LEVELS...WHICH SHOULD
HELP TO LOWER THE CEILINGS AND CAUSE THEM TO GO MORE BROKEN LATE
THIS EVENING AND OVERNIGHT...ALTHOUGH THEY SHOULD STILL REMAIN IN
THE VFR CATEGORY. MODELS ALSO BEGINNING TO INDICATE WEAK LIFT
ASSOCIATED WITH AN APPROACHING FRONT AFTER 06Z TONIGHT...WITH AN
INCREASING CHANCE FOR RAIN SHOWERS. HAVE INCLUDED 6SM -RA
BEGINNING AT 06Z AT AGS/DNL...AND AFTER 08Z AT CAE/CUB/OGB FOR
THIS INCREASED CHANCE FOR RAIN. CONFIDENCE NOT EXTREMELY HIGH YET
FOR ANY KIND OF SIGNIFICANT RAINFALL. WINDS WILL BE LIGHT AND
VARIABLE THROUGH 17Z...THEN BECOME WESTERLY AROUND 7 KNOTS FOR THE
AFTERNOON AND EARLY EVENING...THEN BACK TO LIGHT AND VARIABLE
AFTER SUNSET.
EXTENDED AVIATION OUTLOOK... WIDESPREAD MVFR...POSSIBLE
IFR...CONDITIONS EXPECTED BY WEDNESDAY MORNING THROUGH MID-DAY
WEDNESDAY ASSOCIATED WITH A FRONTAL SYSTEM CROSSING THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
810 AM EST TUE FEB 25 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BE OVER THE AREA THROUGH TODAY. A GULF
COAST LOW PRESSURE SYSTEM WILL MOVE EAST THROUGH GEORGIA AND
FLORIDA TONIGHT INTO WEDNESDAY BRINGING A CHANCE OF RAIN TO
OUR AREA. DRY AND COOLER WEATHER IS EXPECTED THURSDAY AND FRIDAY
WITH ANOTHER CHANCE OF RAIN EARLY SATURDAY WITH A FAST MOVING
SYSTEM.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK SURFACE HIGH PRESSURE REMAINS OVER THE AREA TODAY AS A
DE-AMPLIFYING SHORTWAVE TROUGH MOVES EASTWARD ACROSS THE TENNESSEE
VALLEY AND CROSSES THE FORECAST AREA LATER TODAY. RADAR SHOWING
CLUSTER OF SHOWERS OVER NORTH GEORGIA MOVING TOWARD THE PIEDMONT
AND CSRA. AIR MASS IS RELATIVELY DRY IN THE LOW LEVELS SO EXPECT
PRECIPITATION TO DIMINISH TO THE EAST. LATEST HRRR GUIDANCE HOWEVER
SUGGESTS A FEW SHOWERS WILL MOVE INTO THE PIEDMONT AND POSSIBLY
MIDLANDS LATER THIS MORNING...SO INCREASED POPS TO CHANCE/SLIGHT
CHANCE WEST OF CAE...QPF WILL BE LIGHT. TEMPERATURES WILL BE
SLIGHTLY COOLER THAN ON MONDAY DUE TO THE INCREASING CLOUDS...IN
THE 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
CHANCES OF RAIN INCREASE TONIGHT AS BROAD UPPER TROUGH SINKS
ACROSS THE GREAT LAKES AND OHIO VALLEY REGION DRIVING A COLD FRONT
THROUGH THE FORECAST AREA EARLY WEDNESDAY MORNING BEFORE HIGH
PRESSURE BUILDS IN AT THE SURFACE BEHIND THE FRONT WEDNESDAY
AFTERNOON. WESTERLY LOW LEVEL FLOW AHEAD OF THE SHORTWAVE AND
FRONT IS FORECAST TO BACK MORE SOUTHWESTERLY THIS EVENING ALLOWING
FOR ATMOSPHERIC MOISTURE TO INCREASE WITH FLOW OFF THE WESTERN
GULF OF MEXICO. HOWEVER...THE TIME FRAME FOR SIGNIFICANT MOISTURE
TO MOVE INTO THE REGION BEFORE THE FRONT ARRIVES IS SHORT AND A
LIMITING FACTOR DESPITE MODERATE UPPER DYNAMICS ARRIVING AROUND
THE 12Z TIME FRAME AS THE NORTHERN AND SOUTHERN STREAM JETS COUPLE
TO PROVIDE STRONG OMEGA AND UPWARD VERTICAL MOTION OVER THE
FORECAST AREA.
HAVE INCREASED POPS A BIT TO LOW LIKELY ACROSS THE SOUTHEASTERN
MIDLANDS AND CSRA FROM LATE TONIGHT INTO WEDNESDAY MORNING WITH A
GRADIENT TO LOWER POPS TO THE NORTHWEST WHERE MOISTURE WILL NOT BE
AS GREAT. STILL FIGURE THE BEST TIME FRAME FOR HIGHEST POPS WILL
BE FROM 09Z-15Z WITH CHANCES OF RAIN DECREASING FROM NORTHWEST TO
SOUTHEAST THROUGH THE DAY WEDNESDAY. TEMPERATURES WILL BE MUCH
COOLER WEDNESDAY COMPARED TO TUESDAY WITH COLD ADVECTION TAKING
PLACE DURING THE DAY DESPITE SOME CLEARING SKIES BY AFTERNOON.
COOL AND DRY SURFACE HIGH PRESSURE BUILDS OVER THE AREA WEDNESDAY
NIGHT INTO THURSDAY PROVIDING DRY WEATHER AND BELOW NORMAL
TEMPERATURES. LOWS WEDNESDAY NIGHT WILL BE QUITE COOL AND THE
COLDEST WE HAVE SEEN IN A COUPLE OF WEEK AS TEMPERATURES FALL INTO
THE 20S. HIGHS ON THURSDAY UNDER MOSTLY SUNNY SKIES WILL BE IN THE
MID TO UPPER 50S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MEDIUM RANGE GUIDANCE HAS REMAINED FAIRLY CONSISTENT SHOWING
ANOTHER FAST MOVING UPPER TROUGH CROSSING THE FORECAST AREA FRIDAY
NIGHT AND SATURDAY BRINGING ANOTHER CHANCE OF RAIN TO THE REGION.
THE TRACK OF THE SYSTEM AND ASSOCIATED MOISTURE APPEAR TO BE A BIT
FURTHER NORTH SO HAVE LOWERED POPS A BIT THIS PERIOD. MODEL TRENDS
OF A DEVELOPING STORM SYSTEM OVER THE PLAINS SUN/MON LEAD TO
SOUTHWESTERLY FLOW ALOFT OVER THE SOUTHEAST AND POSSIBLE WARM
ADVECTION IN THE LOWER LEVELS. HAVE TRENDED TEMPERATURES A BIT
WARMER ON THESE DAYS BUT IF TRENDS CONTINUE THESE TEMPERATURES MAY
NEED TO CONTINUE TO BE RAISED WARMER. HOWEVER THIS IS A LOW
CONFIDENCE FORECAST GIVEN PLENTY OF SPREAD IN THE ENSEMBLES AND
DIFFERENCES IN TIMING OF THE OPERATIONAL RUNS.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS STILL FORECAST THROUGH THE TAF PERIOD.
HIGH CLOUDINESS WILL CONTINUE TO MOVE ACROSS THE REGION THROUGH THE
PERIOD AS WEAK UPPER LEVEL WAVES MOVE THROUGH THE MAIN FLOW ALOFT.
SOME MID-LEVEL MOISTURE WILL ATTEMPT TO MOVE EAST OF THE MOUNTAINS
THROUGH THE DAY...BUT DOWNSLOPING FLOW SHOULD HELP TO KEEP ANY LOW
AND MID CLOUDS SCATTERED AT BEST AND SHOULD HELP DISSIPATE ANY LIGHT
SHOWERS EAST OF THE MOUNTAINS. INTO THE OVERNIGHT PERIOD...MODELS
AND BUFKIT SOUNDINGS SHOWING MOISTURE CONTINUING TO INCREASE IN THE
MID LEVELS...WHICH SHOULD HELP TO LOWER THE CEILINGS AND CAUSE THEM
TO GO MORE BROKEN LATE THIS EVENING AND OVERNIGHT...ALTHOUGH THEY
SHOULD STILL REMAIN IN THE VFR CATEGORY. MODELS ALSO BEGINNING TO
INDICATE WEAK LIFT ASSOCIATED WITH AN APPROACHING FRONT AFTER 06Z
TONIGHT...WITH AN INCREASING CHANCE FOR RAIN SHOWERS. HAVE INCLUDED
6SM -RA BEGINNING AT 06Z AT AGS/DNL...AND AFTER 08Z AT CAE/CUB/OGB
FOR THIS INCREASED CHANCE FOR RAIN. CONFIDENCE NOT EXTREMELY HIGH
YET FOR ANY KIND OF SIGNIFICANT RAINFALL. WINDS WILL BE LIGHT AND
VARIABLE THROUGH 17Z...THEN BECOME WESTERLY AROUND 7 KNOTS FOR THE
AFTERNOON AND EARLY EVENING...THEN BACK TO LIGHT AND VARIABLE AFTER
SUNSET.
EXTENDED AVIATION OUTLOOK... WIDESPREAD MVFR...POSSIBLE
IFR...CONDITIONS EXPECTED BY WEDNESDAY MORNING THROUGH MID-DAY
WEDNESDAY ASSOCIATED WITH A FRONTAL SYSTEM CROSSING THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
646 AM EST TUE FEB 25 2014
.PREV DISCUSSION... /ISSUED 422 AM EST TUE FEB 25 2014/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
SURFACE ARCTIC HIGH PRESSURE CONTINUES TO MOVE SOUTHEAST THROUGH THE
PLAIN STATES ATTM AND IS EXPECTED TO SURGE INTO THE REGION LATE TUES
NIGHT INTO EARLY WED. AT THE SAME TIME A WEAK DISTURBANCE WILL BE
ROTATING THROUGH THE SOUTHERN PERIPHERY OF THE LARGER VORTEX
DROPPING SOUTH INTO THE GREAT LAKES REGION. FORECAST CHALLENGE IS
TIMING WRT MOISTURE OVERRUNNING THE COLD AIR BEHIND THE FRONT AND
THE SMALL WINDOW OF OPPORTUNITY FOR SNOW OR A RASN MIX. FROM ROME
TO CARTERSVILLE TO GAINESVILLE....NAM AND GFS FORECAST SOUNDINGS
SHOW MODEST SATURATION BETWEEN 06Z AND 12Z WED AND TEMPS AT OR BELOW
FREEZING INDICATING A A RASN MIX AT THE ONSET AND CHANGING TO ALL
SNOW...ALBEIT LIGHT..BY 09Z AND ENDING BY 12Z. MODELS STRUGGLING TO
LIFT MOISTURE FURTHER NORTH ACROSS FAR NORTH GA...HOWEVER...MODEL
SOUNDINGS MUCH COLDER THERE SO WHATEVER PRECIP WOULD FALL SHOULD BE
ALL OR MOSTLY SNOW. ISENTROPIC ANALYSIS IN THE GFS AT THE 300K LEVEL
FROM 06Z TO 12Z DOES SHOW SOME LIFT WITHIN A SATURATED LAYER AOA
700MB SO PRECIP CERTAINLY CANNOT BE RULED OUT FAR NORTH GA.
OVERALL...ALL MODEL QPFS ARE VERY LIGHT...I.E. LESS THAN 0.1IN OF
LIQUID FOR MOST AREAS NORTH OF I20 SO TOTAL SNOW AMOUNTS SHOULD
REMAIN LESS THAN 0.5IN MOST LOCATIONS. HOWEVER..THAT DOESNT MEAN THE
THREAT IS NEGLIGIBLE. HAVE TENDED TO NOT BUY INTO GUIDANCE TEMPS
OVERNIGHT DURING THE PRECIP PERIOD DUE TO THE LIKELIHOOD OF
WETBULBING SO HAVE TRENDED TEMPS CLOSER TO THE WEBBULB TEMPS
OVERNIGHT WED. THIS METHOD DROPS THE FREEZING LINE DOWN TO THE
NORTH ATL METRO WITH THE ATL METRO HOVERING IN THE 33 TO 34 RANGE.
WITH THE PRECIP FALLING OVERNIGHT AND WETBULB TEMPS RIGHT AROUND
FREEZING...CANNOT RULE OUT SOME BLACK ICE PROBLEMS PARTICULARLY FAR
NORTH METRO AND ALL OF NORTH GA..BUT WILL HAVE TO WATCH FUTURE RUNS
TO GET A HANDLE OF THE TIMING OF COLDER AND DRIER AIR ADVANCEMENT
INTO THE REGION. FURTHER SOUTH IN THE I20 CORRIDOR THINK MOST
PRECIP WILL BE A COLD RAIN BUT HAVE KEPT A FLURRY/RAIN MIX IN FOR
THE ATL METRO FOR A 2 TO 3 HOUR PERIOD WHERE THAT CANNOT BE RULED
OUT GIVEN THE TEMP PROFILE DURING THE 09Z TO 12Z WINDOW. DO NOT
EXPECT ANY IMPACTS FROM THAT UNLESS THE COLD AIR ADVANCES A BIT
FASTER THAN CURRENT PROJECTIONS. DEF WORTH KEEPING AN EYE ON TO SEE
MODEL TRENDS.
SOUTH OF I20..PRECIP CHANCES ARE MUCH HIGHER AND IN THE LIKELY
CATEGORY THROUGH EARLY TO MID AM WED BEFORE CLEARING OUT AREA WIDE
BY EARLY AFTN.
STRONG NORTHWEST WINDS MOVING IN DURING THE DAY WEDNESDAY WITH 15 TO
20 DEGREE BELOW NORMAL TEMPS EXPECTED.
30
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
ARCTIC HIGH PRESSURE BUILDS INTO THE REGION BEHIND THE SHORT-TERM
FRONTAL PASSAGE...WITH TEMPERATURES NOTICEABLY COOLER THAN EARLIER
IN THE WEEK. THIS HIGH PRESSURE REMAINS IN PLACE THROUGH THE
LATTER HALF OF THE WEEK AHEAD OF THE NEXT DISTURBANCE MOVING IN
EARLY SATURDAY...WITH GRADUALLY WARMING TEMPERATURES EXTENDED
PERIOD MODEL CONSENSUS GENERALLY GOOD WITH THIS EARLY WEEKEND
SYSTEM...AND HAVE CONTINUED WITH CHANCE POPS ACROSS A LARGE
PORTION OF THE CWA FOR FRIDAY NIGHT INTO SATURDAY MORNING...WITH
THE BEST CHANCES IN FAR NW GA. HIGH PRESSURE RETURNS TO THE AREA
SUNDAY...AND IT IS AT THIS POINT THAT EXTENDED MODEL SOLUTIONS
DIVERGE AND UNCERTAINTY INCREASES. THE ECMWF PULLS THE FRONT
THROUGH THE STATE LATE SUNDAY NIGHT...WHILE THE GFS DELAYS THE
ONSET UNTIL LATE MONDAY NIGHT...AFTER THE EUROPEAN CLEARS THE
PRECIPITATION FROM THE AREA. HAVE GENERALLY GONE WITH CHANCE POPS
SUNDAY NIGHT THROUGH THE DAY TUESDAY TO ACCOUNT FOR THE VARIED
SOLUTIONS...AND EXPECT AS WE GET IN TO LATE WEEK THE DURATION THE
CHANCE POPS WITH THIS FRONT WILL DECREASE.
JUST AS THE MODELS DIFFER IN THE PRECIP TIMING FOR LATE WEEKEND
AND EARLY NEXT WEEK...SO DO THE TEMPERATURES. HAVE RAISED SUNDAY
TEMPERATURES A FEW DEGREES FROM THE PREVIOUS FORECAST TO ACCOUNT
FOR THE EXPECTED SOUTHERLY FLOW AHEAD OF THE FRONTAL PASSAGE AND
THICKNESSES SUPPORTIVE OF HIGHS IN THE MID TO UPPER 60S. EVEN THE
CURRENT FORECAST TEMPERATURES MAY BE TOO COOL.
31
&&
.AVIATION...
12Z UPDATE...
NO MAJOR CHANGES FROM PREVIOUS FORECAST THINKING. WAS TEMPTED TO
ADD VCSH OR A TEMPO GROUP IN FOR THE BAND OF RAIN MOVING EAST-SOUTHEAST
OUT OF ALABAMA INTO NORTH GA. LATEST HRRR RUNS EVAPORATE THAT AREA
QUICKLY AS IT IMPEDES UPON DRY AIR ALOFT OVER GA. PREVIOUS RUNS
MAINTAINED SOME SHOWER ACTIVITY INTO THE I20 CORRIDOR. HAVE TAKEN
MENTION OF RAIN OUT THIS MORNING THINKING THAT IT WILL DRY UP AS
THE HRRR SUGGESTS...BUT MAY HAVE LATER SHIFTS AMEND IF IT DOES NOT
AS QUICKLY. OVERALL...MODELS DID NOT HANDLE THAT AREA WELL. CIGS
INCREASE THROUGH THE DAY...PARTICULARLY AFTER 16Z TO 18Z FOR MOST
TAF SITES. CONTINUED WITH PROB30 SHRA INTO MOST LOCATIONS 23Z TO
00Z AND EXPECT A GRADUAL INCREASE IN SHOWER ACTIVITY PARTICULARLY
AFTER 06Z THROUGH 12Z WITH A PRIME PERIOD 08Z THRU 11Z. HAVE
INSERTED SHRA AS PREVAILING FOR ATL DURING THAT TIME...AM STILL
HESITANT TO PUT A RASN MIX IN FOR ATLANTA AS ATL SEEMS TO BE THE
SOUTHERN EXTENT WHERE THERE WOULD BE ANY OR EVEN A SLIGHT CHANCE
FOR THAT TO OCCUR BASED ON LATEST FORECAST SOUNDINGS. WILL WAIT TO
SEE LATER RUNS AS CONFIDENCE STILL LOW. RMG TO GVL APPEARS TO HAVE
A HIGHER PROB OF SEEING A RASN MIX ALTHOUGH TOTAL AMOUNTS WILL BE
LOWER. BEST WINDOW FOR THIS...IF IT OCCURS PER NAM AND GFS
SOUNDINGS..IS 08Z TO 11Z.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON PRECIP NOT MAKING IT TO ATL THIS MORNING.
MEDIUM ON CIGS AND TIMING OF PRECIP ONSET TONIGHT.
HIGH ALL OTHER ELEMENTS.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 67 35 51 27 / 10 60 50 5
ATLANTA 63 33 43 25 / 10 60 50 0
BLAIRSVILLE 57 30 41 20 / 40 30 20 0
CARTERSVILLE 61 32 42 21 / 20 50 30 0
COLUMBUS 70 43 48 28 / 5 80 70 5
GAINESVILLE 62 32 46 26 / 10 50 30 0
MACON 72 45 49 26 / 5 70 70 5
ROME 59 32 41 20 / 30 50 30 0
PEACHTREE CITY 64 35 46 22 / 10 70 50 0
VIDALIA 75 50 52 36 / 5 60 80 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...30
LONG TERM....31
AVIATION...30
AREA FORECAST DISCUSSION...CORRECTED
NWS BOISE ID
327 AM MST TUE FEB 25 2014
.SHORT TERM...TODAY THROUGH WEDNESDAY...UPDATED HIGH TEMPERATURES
AS MORNING WEATHER BALLOON SOUNDING INDICATED ANOTHER 3 TO 5
DEGREES OF WARMING BELOW 10K FT MSL. /END UPDATE/ DEEP MOISTURE
AXIS ACROSS OREGON AND CENTRAL IDAHO WILL COMBINE WITH AN UPPER
LEVEL TROUGH DROPPING THROUGH THE NORTHERN ROCKIES FOR NUMEROUS
SHOWERS ACROSS THE WEST CENTRAL MOUNTAINS MAINLY THIS MORNING.
CLOUDINESS WILL DECREASE ACROSS SOUTHERN AREAS SO EXPECT ANOTHER
MILD LATE AFTERNOON WITH HIGHS IN THE 50S TO AROUND 60. PWAT ARE
ABOVE NORMAL AT 0.50 INCHES VS 0.33 INCHES BUT AMOUNTS WON`T BE
ENOUGH FOR ANY HEADLINES...MORE LIKE A HIGH POP/LOW QPF EVENT. THE
MORNING SNOW LEVEL AROUND 5500 FEET WILL RESULT IN A RAIN/SNOW MIX
AT MCCALL FROM 5 TO 9 AM THEN CHANGE BACK TO RAIN BEFORE TAPERING
THIS EVENING. HRRR AND 0Z/6Z NAM KEEP BANDED SHOWERS GOING AT
VARIOUS LOCATIONS ACROSS NE OREGON OR CENTRAL IDAHO THIS AFTERNOON
SO HAVE SCATTERED SHOWERS LATER TODAY IN THE HIGHER TERRAIN OF THE
PAYETTE NF/BOISE NF AS WELL AS SOUTH PARTS OF THE WALLOWA WHITMAN
FOREST IN OREGON. AS THE UPPER LEVEL RIDGE MOVES OVER THE AREA
TONIGHT THROUGH WEDNESDAY MORNING EXPECT DRY WX. WEDNESDAY...IN
THE AFTERNOON OVER OREGON AND LATE AFTERNOON OVER THE SW IDAHO
MOUNTAINS THERE SHOULD BE ENOUGH MOISTURE AN LIFT AHEAD OF THE
NEXT INCOMING SYSTEM FOR LOW CHANCES OF RAIN...AND HIGH MOUNTAIN
SNOW ABOVE 6500-7200 FEET. TEMPERATURES PEAK WEDNESDAY AROUND 8-12
DEGREES ABOVE NORMAL.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...FORECAST REMAINS ON
TRACK FOR AN ACTIVE PATTERN THROUGH EARLY NEXT WEEK. THE FIRST ROUND
OF PRECIPITATION WILL BEGIN WEDNESDAY NIGHT THROUGH THURSDAY AS A
WEAK UPPER TROUGH MOVES ACROSS THE REGION FROM THE SOUTHWEST TO
NORTHEAST. SNOW LEVELS REMAIN ABOVE 6000 FEET FOR MODERATE SNOW
ACCUMULATIONS ON THE MOUNTAIN PEAKS. LIGHT RAIN AMOUNTS EXPECTED IN
THE VALLEYS. A BRIEF BREAK ON FRIDAY WILL BE FOLLOWED BY MORE
SHOWERS OVER THE WEEKEND AS AN UPPER LEVEL TROUGH CROSSES CALIFORNIA
AND MOVES OVER THE GREAT BASIN. A MAJORITY OF GUIDANCE FAVORS THE
WARMER ECMWF INCLUDING MOST OF THE GFS ENSEMBLES MAKING THE
OPERATIONAL GFS THE ODD MODEL OUT. THE UPPER LOW WEAKENS AND SPLITS
AS IT MOVES INLAND ACROSS CALIFORNIA ON FRIDAY. THE NORTHERN SPLIT
MOVES ACROSS THE REGION ON SATURDAY KEEPING THE ARCTIC COLD FRONT
NORTH AND EAST OF THE AREA. EXPECT PRECIPITATION ACROSS THE AREA
THROUGH MONDAY WITH THE MOUNTAINS BEST CHANCE FOR SNOW ON SUNDAY.
TEMPERATURES WILL BE NEAR NORMAL TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...MVFR CONDITIONS IN RAIN AND SNOW MAINLY ACROSS THE WEST
CENTRAL AND BOISE MOUNTAINS OF IDAHO AND THE HIGHER TERRAIN OF BAKER
COUNTY TODAY. PRECIPITATION WILL BE MOSTLY RAIN EVEN AT KBKE AND
KMYL WITH A MIX OF RAIN AND SNOW POSSIBLE THROUGH 15Z.
ELSEWHERE...VFR CONDITIONS WITH BROKEN TO OVERCAST CEILINGS RANGING
FROM 5K-10K FEET AGL ALONG WITH AREAS OF MOUNTAIN OBSCURATION.
SURFACE WINDS 10-15 KTS FROM THE WEST-NORTHWEST. WINDS ALOFT WILL BE
WESTERLY AROUND 20 KNOTS UP THROUGH 10K FEET MSL.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
SHORT TERM...VM
LONG TERM....JS
AVIATION.....JS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
523 AM CST TUE FEB 25 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 259 AM CST TUE FEB 25 2014
CLOUDS AND OCCASIONAL FLURRIES ARE LINGERING IN THE AREA. SUBJECTIVE
00Z UPPER AIR ANALYSIS INDICATES UPPER-LEVEL SHORTWAVE TROUGH NEAR
THE SD/ND BORDER...WITH 500MB HEIGHT FALLS UP TO 90M AHEAD OF IT IN
EASTERN SD. 08Z WATER VAPOR AND RAP 1.5 PVU PRESSURE INDICATE
STRONG UPPER-LEVEL TROUGH DIGGING THROUGH IA THIS MORNING...WITH
SECONDARY SHORTWAVE UPSTREAM IN NORTHERN MT. STRONGEST UPPER-LEVEL
JET EXTENDED FROM MT THROUGH WESTERN SD INTO EASTERN NEB/IA AND
EASTWARD ACROSS THE MID-ATLANTIC. MUCH COLDER AIR WAS FILTERING
INTO THE PLAINS IN WAKE OF THE TROUGH...WITH 850MB TEMPERATURES -20C
OR COLDER IN ND/MT AND UPPER TEENS BELOW ZERO SPILLING INTO SD.
MAIN FORECAST CONCERN IS POTENTIAL FOR LIGHT SNOW TO CLIP THE
SOUTHWEST CWA TODAY...THEN ONE MORE DAY OF MODERATE TEMPERATURES
BEFORE THE COLD AIR PLUNGES INTO THE PLAINS. WEAK LIFT IN THE
DENDRITIC ZONE WILL EXIT THE AREA BY THIS MORNING...AND FLURRIES
SHOULD END FOR A TIME. SECOND...WEAKER SHORTWAVE WILL SLIDE THROUGH
THE NORTHERN ROCKIES TOWARD WESTERN/CENTRAL NEB TODAY...WITH WEAK
FRONTOGENETIC BAND AROUND 700-650MB SETTING UP FROM WESTERN TO SOUTH
CENTRAL NEB THIS AFTERNOON. SHOULD SEE SNOW WITH THAT BAND...BUT
EASTERN EXTENT IS IN QUESTION AS BETTER SUPPORT REMAINS WEST OF THE
AREA...AND DRIER LOW-LEVEL AIR BELOW THE MORE SATURATED MID-LEVELS
MAY HINDER MEASURABLE SNOW. HAVE CONTINUED TO INDICATE SLIGHT CHANCE
OF SNOW IN SOUTHEAST NEB THIS AFTERNOON...TAPERING AWAY BY THIS
EVENING.
WESTERLY WINDS RETURN TO THE AREA ON WEDNESDAY. WHILE SNOW ON THE
GROUND WILL HINDER TEMPERATURES IN THE NORTHERN CWA...THE COUPLE OF
TENTHS THAT FELL ELSEWHERE ARE NOT LIKELY TO COUNTERACT THE
FAVORABLE MIXING WINDS. HAVE KEPT TEMPS ABOVE GUIDANCE IN THE 30S
ACROSS MOST OF THE AREA...AS THE LAST DAY THAT COULD RISE ABOVE
FREEZING FOR QUITE SOME TIME. REINFORCING COLD AIR ARRIVES ON
WEDNESDAY NIGHT/THURSDAY AS A COLD AND DRY HIGH PRESSURE SLIDES OUT
OF THE DAKOTAS/MN INTO WESTERN IA. MID-LEVEL WARM AIR ADVECTION IS
PROGGED TO DEVELOP ON THE WESTERN SIDE OF THE HIGH ON THURSDAY
NIGHT...BUT GIVEN DRY AIR FEEDING IN FROM THE EAST...BELIEVE PRECIP
WILL BE HELD AT BAY THROUGH 12Z FRIDAY. MODELS HAVE TRENDED IN THAT
DIRECTION AS WELL...WITH ALL SOLUTIONS BUT THE NAM NOW DRY FOR
THURSDAY NIGHT. HAVE REMOVED POPS ACROSS THE AREA.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 259 AM CST TUE FEB 25 2014
ALTHOUGH THERE IS A BRIEF ATTEMPT AT MODERATION ON FRIDAY...PATTERN
TURNS COLDER THROUGH THE WEEKEND/MONDAY...WITH MUCH BELOW
NORMAL TEMPERATURES AND CHANCES OF LIGHT SNOW PERSISTING.
GOOD AGREEMENT BETWEEN 00Z GFS/ECMWF IN A DECENT H7 LOW/TROUGH
MOVING ALONG KS BORDER FRIDAY BRINGING MODEST SNOW CHANCES TO MUCH
OF THE FA...ESPECIALLY CNTRL/SRN ZONES. AFTER THAT THE COLD AIR IS
REINFORCED OVER THE NRN/CENTRAL PLAINS AS SEVERAL LOBES PIVOT AROUND
HUDSON BAY LOW SENDING COLD HIGH PRESSURE SOUTHWARD. MEANWHILE...
THE MID LEVEL FLOW OVER THE PLAINS REMAINS MORE WRLY AND EVEN
SWRLY AT TIMES. THUS PERIODS OF SNOW CHANCES WILL
PERSIST...ALTHOUGH NO MAJOR SYSTEMS WERE CURRENTLY SUGGESTED FOR
FA BY 00Z MODELS. BASED ON 00Z RUNS OF GFS/ECMWF IT DOES APPEAR
SOMEWHAT OF A LULL POSSIBLE FRIDAY NIGHT OVER MUCH OF THE
AREA...SATURDAY ACROSS THE SOUTH AND THEN MOST OF THE REGION BY
MONDAY. PRECIPITATION MENTION DURING THOSE TIMES WAS KEPT MOSTLY
IN THE SLIGHT CHANCE CATEGORY...ALTHOUGH WITH MID LEVEL
TEMPERATURES FAVORABLE FOR ICE CRYSTAL GENERATION IT WOULD NOT
TAKE MUCH TO GENERATE AREAS OF LIGHT SNOW ANY OF THOSE PERIODS IF
MOISTURE IS PRESENT. WITH H85 TEMPERATURES OF -15 TO -25 FORECAST
TO SAG SWD THROUGH FA SAT/SUN...MAX TEMPERATURES MAY REMAIN IN
SINGLE DIGITS MANY AREAS SATURDAY AND POSSIBLY EVEN SUNDAY NRN
ZONES WITH MEX/ECE GUIDANCE POSSIBLY INFLUENCED BY CLIMO WITH
NORMAL HIGHS NOW APPROACHING OR EXCEEDING 40 DEGREES F. TRIMMED
BACK HIGHS A BIT SATURDAY/SUNDAY. LEFT LOWS MOSTLY ALONE FOR
NOW...SINGLE DIGITS EITHER SIDE OF ZERO F...AS CLOUD INFLUENCES
ENOUGH OF A THREAT WITH THE WEST OR POSSIBLY SW MID LEVEL FLOW
RIDING OVER COLD LOW LEVEL FLOW.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 520 AM CST TUE FEB 25 2014
AS HIGH PRESSURE BUILDS SOUTH INTO NRN NEBRASKA THIS MORNING MVFR
CIGS SHOULD CONTINUE TO CLEAR SOUTH OF KLNK/KOMA AND LIGHT SNOW
SHOULD ALSO END. HOWEVER...MID LEVEL CLOUDS...GENERALLY WITH ANY
CIGS ABV FL070...WILL SPREAD/DEVELOP ESE INTO ERN NEBR LATER THIS
MORNING THROUGH THIS AFTERNOON AS A DISTURBANCE MOVES ACROSS THE
STATE. SOME LIGHT SNOW COULD DEVELOP AS WELL...BUT INDICATIONS AT
12Z TAF ISSUANCE TIME WERE THAT ANY SIGNIFICANT IMPACT WOULD BE W
THROUGH S OF TAF SITES THUS NO MENTION WAS MADE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MAYES
LONG TERM...CHERMOK
AVIATION...CHERMOK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
923 AM EST TUE FEB 25 2014
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT OFF THE VIRGINIA COAST TODAY. A COLD
FRONT WILL MOVE ACROSS THE AREA TONIGHT INTO WEDNESDAY...BRINGING
SOME SHOWERS. COLD HIGH PRESSURE WILL BRING WELL BELOW NORMAL
TEMPERATURES FROM WEDNESDAY INTO THE WEEKEND. A SIGNIFICANT WARM-
UP IS POSSIBLE FOR EARLY NEXT WEEK...ALONG WITH INCREASING RAIN
CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9:30 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
A RATHER COMPLEX 24 HOURS IS AHEAD OF US WEATHER WISE. SURFACE HIGH
PRESSURE IS MOVING OFF THE DELMARVA COAST THIS MORNING...WITH
VEERING WINDS ALREADY OBSERVED OFFSHORE AT THE FRYING PAN SHOALS
BUOY. WARM FRONTOGENESIS IS OCCURRING JUST OFFSHORE AS THE AIRMASS
QUICKLY MODIFIES OVER RELATIVELY WARM WATER TEMPS. UP AT 300 MB
THERE ARE TWO BRANCHES OF THE JET DISCERNIBLE: THE POLAR JET LIES
ACROSS THE CENTRAL APPALACHIANS AND MID-ATLANTIC REGION...WHILE
THE SUBTROPICAL JET COMES OUT OF NORTHERN MEXICO AND CROSSES THE
GULF COAST. CIRRUS CLOUDS COVERING THE CAROLINAS EARLY THIS
MORNING ARE DUE TO A WEAK DISTURBANCE IN THE SUBTROPICAL JET OVER
NORTHERN FLORIDA THAT SHOULD BE OFFSHORE IN THE NEXT FEW HOURS.
A SECOND SUBTROPICAL JET DISTURBANCE WILL MOVE THROUGH THE
SOUTHERN MS VALLEY THIS AFTERNOON. OUR OFFSHORE WARM FRONT WILL BE
DRAWN INLAND TODAY BY SURFACE PRESSURE FALLS OCCURRING AHEAD OF
THIS DISTURBANCE. WITH SEVERAL HOURS OF MOSTLY SUNNY SKIES
EXPECTED THIS MORNING THIS SHOULD ALLOW TEMPERATURES TO RISE INTO
THE 60S AND LOWER 70S BY EARLY AFTERNOON...WARMEST SOUTH OF
FLORENCE AND CONWAY. DURING THE MID AND LATE AFTERNOON MOISTURE
WILL INCREASE FROM THE WEST BETWEEN 850 AND 700 MB. COUPLED WITH
MODEST ISENTROPIC LIFT ALONG THE 295K THETA SURFACE THIS COULD
PRODUCE ISOLATED SHOWERS. POPS ARE LIMITED TO 20 PERCENT AND
MAINLY FOR COASTAL LOCATIONS.
THIS EVENING THE BEST PRESSURE FALLS WILL SHIFT OFFSHORE AS A MUCH
STRONGER POLAR JET DISTURBANCE APPROACHES FROM THE NORTHWEST. THIS
WILL TAKE THE WARM FRONT ACROSS EAST-CENTRAL NORTH CAROLINA AND
PUSH IT SOUTHWARD AS A COLD FRONT BEHIND A DEEPENING SURFACE LOW
OFFSHORE...WITH COOLER AIR SURGING SOUTHWARD TO THE SANTEE RIVER
OVERNIGHT. ISENTROPIC FIELDS INDICATE LITTLE POTENTIAL FOR
PRECIPITATION DURING THE EVENING HOURS...HOWEVER INCREASING LIFT
AGAIN ALONG THE 295K THETA SURFACE VERY LATE TONIGHT SHOULD
PRODUCE AN AREA OF SHOWERS ACROSS SOUTH CAROLINA SPREADING TO THE
NC/SC COAST BY DAYBREAK.
BOTH THE 06Z GFS AND NAM LOOK WARMER WITH DAYTIME TEMPS TODAY THAN
THEIR 00Z COUNTERPARTS DID. THE INTER MODEL DIFFERENCES BETWEEN THE
NEW GFS AND NAM HAVE DECREASED RELATIVE TO THE LARGER DIFFERENCES
DISPLAYED ON THE 00Z RUNS WHERE THE GFS APPEARED MUCH TOO COLD.
BASED ON THIS TREND AND THE LATEST FEW RUNS OF THE RUC I HAVE
RAISED HIGH TEMP FORECASTS TODAY...EXPANDING THE AREA OF LOWER 70S
IN THE KINGSTREE-GEORGETOWN-CONWAY AREA THIS AFTERNOON. UPPER 60S
ARE FORECAST FOR MOST AREAS EAST OF I-95 AND SOUTH OF
ELIZABETHTOWN. LOWER TO MID 60S ARE STILL EXPECTED NORTH OF
FLORENCE...DILLON... ELIZABETHTOWN AND WATHA.
FOR TONIGHT: THE 00Z NAM MODEL APPEARS TO HAVE A BETTER HANDLE ON
THE DEVELOPMENT AND MOVEMENT OF THE WARM FRONT TODAY AND THE
OFFSHORE LOW TONIGHT. THE NAM`S MAX/MIN TEMPERATURES ALSO APPEAR
BETTER THAN THE GFS... ALTHOUGH IT IS CURIOUS WHY BOTH THE NAM AND
GFS MOS PRODUCTS ARE SO COOL WITH HIGHS TODAY GIVEN RAW MODELS
RUNNING SEVERAL DEGREES WARMER. MY FORECAST HIGHS ARE WARMER THAN
NAM OR GFS MOS... PARTICULARLY NEAR THE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...COLD FRONT WILL BE DRAPED ALONG OR JUST
SOUTH AND OFFSHORE OF THE CWA AT THE START OF THE PERIOD. MOST
DIFFICULT PART OF THE FORECAST WILL BE HOW THE INTERACTION OF THIS
BOUNDARY AND SOME ENHANCED MOISTURE RETURN WILL AFFECT THE CWA
WITH RAINFALL ON WEDNESDAY. THE COLD FRONT WILL MOVE ONLY VERY
SLOWLY SOUTHWARD AS THE REGION REMAINS BENEATH THE BASE OF THE
EASTERN TROUGH...THUS FLOW BECOMES NEARLY BOUNDARY-PARALLEL ON
WEDNESDAY. AS THIS FRONT STALLS NEAR THE AREA...MOISTURE INCREASES
ALONG IT...AND SOME WEAK LIFT DUE TO MID-LEVEL IMPULSES WILL TRY
TO SPAWN SOME POST-FRONTAL RAINFALL ACROSS THE CWA. NAM/GFS ARE
WETTER AND IN BETTER AGREEMENT THAN THE ECMWF...SO WILL LEAN MORE
ON THESE MODELS FOR PRECIP POTENTIAL ON WEDNESDAY. THE BEST
CHANCES FOR PRECIP WILL BE ALONG THE SE THIRD OF THE CWA...CLOSEST
TO THE BOUNDARY AND WHERE ISENTROPIC LIFT FROM 290-300K IS
FOCUSED...BUT SREF PROBS SUGGEST AT LEAST 60% 12-HR CHANCE OF 0.01
QPF ACROSS THE ENTIRE CWA. INHERITED POP HAS LIKELY ACROSS THE
EAST WITH HIGH-CHC WEST...AND WILL BUMP THESE NUMBERS BUT KEEP
WITHIN THE SAME CATEGORIES FOR WEDNESDAY. HIGHEST CHANCES WILL BE
WED MORNING INTO THE AFTN...DROPPING FROM NW TO SE THROUGH THE EVE
AS THE FRONT DRIFTS SLOWLY AWAY AND THE MID-LEVEL IMPULSE PUSHES
EASTWARD.
WHILE THE WEAK CAA...CLOUDS...AND RAIN WILL KEEP TEMPS WEDNESDAY
WELL BELOW NORMAL...AROUND 50 FOR HIGHS...SKY CONDITIONS WILL
CLEAR RAPIDLY WED NIGHT. AT THE SAME TIME...HIGH PRESSURE FROM THE
WEST WILL CONTINUE TO RIDGE TOWARDS THE AREA. A RELATIVELY WEAK
PRESSURE GRADIENT WED NIGHT WILL LEAVE ONLY LIGHT NORTH WINDS
AHEAD OF THIS HIGH PRESSURE...WHICH COMBINED WITH CLEARING SKY
CONDITIONS WILL CREATE A COLD NIGHT INTO THU MORNING...AND EXPECT
NEARLY THE ENTIRE AREA TO FALL BELOW FREEZING...WITH MID 20S
POSSIBLE IN THE TYPICALLY COLDER SPOTS.
SUBTLE AIR MASS MODIFICATION OCCURS THURSDAY THANKS TO SURFACE
HIGH PRESSURE RIDGE AXIS BULGING UP TOWARDS THE MID-ATLANTIC. THIS
WILL BE SOMEWHAT OFFSET BY CONTINUED LOW THICKNESSES SOUTH OF THE
COLD 5H VORTEX ACROSS NEW ENGLAND...AND THUS WHILE THURSDAY WILL
BE WARMER THAN WEDNESDAY...TEMPS WILL STAY BELOW NORMAL...RISING
ONLY INTO THE MID 50S...WITH A FEW UPPER 50S POSSIBLE NEAR THE
SOUTH SANTEE RIVER. A RENEWED SURGE OF COLD AIR IS NOW PROGGED FOR
THURSDAY NIGHT AS A SECONDARY DRY COLD FRONT CROSSES AHEAD OF
ARCTIC HIGH PRESSURE DROPPING OUT OF CANADA. THIS WILL CREATE A
COLD AND BREEZY NIGHT THURSDAY NIGHT...AS LOW DROP ONCE AGAIN TO
FREEZING OR BELOW...WITH EVEN COLDER APPARENT TEMPS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...COLD TO START THE EXTENDED AS ARCTIC HIGH
PRESSURE DEVELOPS INTO A WEDGE ALONG THE EAST COAST. THIS WILL
CREATE COOL NE WINDS INTO THE FIRST HALF OF THE WKND...WITH TEMPS
REMAINING SOLIDLY BELOW CLIMO FOR THE END OF FEBRUARY. WHILE
GUIDANCE HAS BEEN ADVERTISING A SOUTHERN STREAM LOW FOR SEVERAL
DAYS NOW...THIS FEATURE HAS BECOME LESS INTENSE...AND NOW THE
SURFACE REFLECTION HAS BASICALLY DISAPPEARED THANKS TO WEAKER MID-
LEVEL FORCING AND BAROCLINIC INSTABILITY. STILL...THERE IS AT
LEAST DECENT POTENTIAL FOR SOME SHOWERS ON SATURDAY BENEATH THE
MID-LEVEL IMPULSE...BUT OVERALL QPF LOOKS LIMITED.
ADDITIONALLY...WITH THE COOL AIR IN PLACE WITHIN THE WEDGE...THIS
OVERRUNNING SCENARIO MAY PROMOTE A MIXED P-TYPE EVENT...ESPECIALLY
WELL INLAND. TEMPS WILL BE MARGINAL AT-BEST FOR ANYTHING OTHER
THAN THAT LIQUID...AND WILL KEEP -RW AS WX TYPE FOR NOW...BUT
THERE IS AT LEAST A SMALL CHANCE FOR SOME FROZEN PRECIP FRIDAY
NIGHT/SAT AM.
GUIDANCE DIFFERS CONSIDERABLY INTO THE BEGINNING OF NEXT WEEK. GFS
BREAKS DOWN THE WEDGE QUICKLY AS MID-LEVEL RIDGING
DEVELOPS...CENTERED OFF THE FLORIDA COAST. ECMWF SHOWS A SIMILAR
PROCESS BUT WITH A SLOWER TEMPORAL EVOLUTION. THIS CAUSES 15+
DEGREE TEMP DIFFERENCES IN THE FORECASTS FOR NEXT WEEK. A QUICK
GLANCE AT SOME OF THE ENSEMBLES SUGGESTS THAT THE OP-GFS IS WELL
TOO WARM AS IT IS ON THE HIGH SIDE OF ALL ITS ENSEMBLE
THICKNESSES. STILL...THE UPPER PATTERN FAVORS WEDGE BREAKDOWN AND
AT LEAST A MARGINAL WARMUP SUN/MON...SO WILL BUMP TEMPS TOWARDS
AND ABOVE CLIMO FOR EARLY NEXT WEEK. A MORE IMPRESSIVE LOW
PRESSURE SYSTEM MAY APPROACH MONDAY...AND WILL KEEP INHERITED CHC
POP ATTM.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
OF 12Z...CURRENTLY VFR CONDITIONS PREVAIL ACROSS THE CWA WITH MID
TO HIGH CLOUDS MOVING OVERHEAD. LIGHT AND VARIABLE WINDS WILL
SHIFT TO THE SOUTH AND THEN SOUTHWEST BY MIDDAY AS A DEVELOPING
WARM FRONT OFFSHORE MOVES NORTHWARD. TIME-HEIGHT ANALYSIS SHOWS
INCREASING LOW TO MID LEVEL MOISTURE THIS AFTERNOON...AND WILL
KEEP VCSH FOR THE COASTAL SITES AS AN ISOLATED SHOWER CANNOT BE
RULED OUT. EXPECT SOUTHWEST WINDS AROUND 10 KTS THROUGH THE
AFTERNOON HOURS. THIS PATTERN WILL QUICKLY CHANGE THIS EVENING AS
LOW PRESSURE DEVELOPS OFF THE NC/VA COAST. THE WINDS OVERNIGHT
WILL BECOME N-NE ON THE BACK SIDE OF THIS LOW. LOW CLOUDS AND RAIN
CHANCES WILL INCREASE TOWARD DAYBREAK AS THE COLD FRONT REMAINS
DRAPED JUST TO OUR SOUTH. KFLO/KLBT MAY SEE MVFR CIGS DEVELOP BY
THE END OF THE VALID PERIOD AS A REGION OF ISENTROPIC LIFT AND -RA
SPREADS INTO OUR INLAND ZONES.
EXTENDED OUTLOOK...RAIN WITH MVFR CIGS ON WEDNESDAY. VFR THURSDAY
AND FRIDAY. CHANCE OF RAIN/MVFR ON SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 9:30 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
SEASONS WILL CHANGE AT LEAST TWICE ACROSS THE COASTAL WATERS TODAY
AS A FRONT WAVERS ACROSS THE AREA. A WARM FRONT DEVELOPING ACROSS
THE COASTAL WATERS SHOULD PUSH INLAND LATER THIS MORNING...WITH
EAST WINDS VEERING TO THE SOUTH. WINDS SPEEDS WILL INCREASE TO
10-15 KNOTS AS DIRECTIONS CONTINUE TO VEER SOUTHWESTERLY DURING
THE AFTERNOON. THIS VEERING SHOULD BE IN RESPONSE TO FALLING
PRESSURES AS LOW PRESSURE DEVELOPS ALONG THE COAST TODAY...THEN
OFFSHORE THIS EVENING. CLOCKWISE WINDS BLOWING AROUND THIS LOW
SHOULD PUSH THE WARM FRONT BACK SOUTHWARD AS A COLD FRONT THIS
EVENING. THE FRONT MAY PRESS ALL THE WAY TO THE SANTEE
RIVER...WITH NORTH TO NORTHEAST WINDS STRONGEST ACROSS THE NC
WATERS CLOSEST TO THE POSITION OF THE LOW.
SEAS CURRENTLY RANGE FROM 2-3 FEET WITH DOMINANT PERIODS AROUND 9
SECONDS IN SOUTHEAST SWELL. A SMALL SHORT PERIOD CHOP WILL DEVELOP
IN THE SOUTH-SOUTHWEST WIND BEHIND THE WARM FRONT...WITH CONFUSED
SEAS FOR A PERIOD THIS EVENING AS WINDS SHIFT TO THE NORTH AS THE
FRONT IS PUSHED ACROSS AGAIN. TOTAL SEA HEIGHTS WILL PROBABLY NOT
EXCEED 4 FEET AT ANY POINT THROUGH TONIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...COLD FRONT MOVING OFFSHORE AT THE START OF
THE PERIOD WILL DRIFT SOUTH OF THE AREA INTO THURSDAY...WITH
NORTHERLY WINDS INCREASING TO 15-20 KTS...AND REMAINING AT THESE
SPEEDS INTO THURSDAY MORNING. THESE WINDS WILL EASE AND BACK TO
THE SW ON THURSDAY AS A RIDGE OF HIGH PRESSURE BRIEFLY ENVELOPS
THE AREA...BUT WILL QUICKLY RETURN TO THE NORTH AT 15-20 KTS AT
THE END OF THE PERIOD AS A SECOND COLD SURGE MOVES ACROSS THE
WATERS. EVEN THOUGH WINDS WILL BE GUSTY ON WEDNESDAY...THE
NORTHERLY COMPONENT WILL INHIBIT SUBSTANTIAL WAVE GROWTH...AND
THUS SEAS WILL RISE TO PEAK AT 3-5 FT WEDNESDAY EVE...BEFORE
FALLING BACK TO 1-3 FT DURING THURSDAY. RENEWED AMPLIFICATION IS
EXPECTED AT THE END OF THE SHORT TERM AS THE WINDS ONCE AGAIN RISE
FROM THE NORTH...WITH WAVE HEIGHTS BECOMING 2-4 FT BY FRIDAY
MORNING.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 300 AM TUESDAY...DEVELOPING WEDGE OF HIGH PRESSURE EXTENDING
DOWN THE EAST COAST WILL CREATE A PROLONGED PERIOD OF NE WINDS
OVER THE COASTAL WATERS...AND CAUTIONARY STATEMENTS MAY BE
REQUIRED ON FRIDAY. STRENGTHENING WEDGE FRIDAY FORCES A PINCHED
PRESSURE GRADIENT...AND NE WINDS RISE TO AROUND 20 KTS ALL OF
FRIDAY...DRIVING SEAS UP TO 4-5 FT...EXCEPT SW OF BRUNSWICK COUNTY
WHERE THE WAVE SHADOW REGION WILL PERMIT ONLY MUCH SMALLER WAVE
HEIGHTS. GRADIENT WILL EASE AT LEAST MARGINALLY ON
SATURDAY...ALLOWING NE WINDS TO FALL TO 10-15 KTS...WITH SEAS
FOLLOWING TO 2-4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...REK/TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...TRA
MARINE...REK/TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
636 AM EST TUE FEB 25 2014
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT OFF THE VIRGINIA COAST TODAY. A COLD FRONT
WILL MOVE ACROSS THE AREA TONIGHT INTO WEDNESDAY BRINGING SOME
SHOWERS. COLD HIGH PRESSURE WILL BRING WELL BELOW NORMAL
TEMPERATURES WEDNESDAY AND INTO THE WEEKEND. A SIGNIFICANT WARM-UP
IS POSSIBLE FOR EARLY NEXT WEEK...ALONG WITH INCREASING RAIN CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 63AM TUESDAY...A RATHER COMPLEX 24 HOURS IS AHEAD OF US
WEATHERWISE. SURFACE HIGH PRESSURE IS MOVING OFF THE DELMARVA COAST
THIS MORNING...WITH VEERING WINDS ALREADY OBSERVED OFFSHORE AT THE
FRYING PAN SHOALS BUOY. WARM FRONTOGENESIS IS OCCURRING JUST
OFFSHORE AS THE AIRMASS QUICKLY MODIFIES OVER RELATIVELY WARM WATER
TEMPS. UP AT 300 MB THERE ARE TWO BRANCHES OF THE JET DISCERNIBLE:
THE POLAR JET LIES ACROSS THE CENTRAL APPALACHIANS AND MID-ATLANTIC
REGION...WHILE THE SUBTROPICAL JET COMES OUT OF NORTHERN MEXICO AND
CROSSES THE GULF COAST. CIRRUS CLOUDS COVERING THE CAROLINAS EARLY
THIS MORNING ARE DUE TO A WEAK DISTURBANCE IN THE SUBTROPICAL JET
OVER NORTHERN FLORIDA THAT SHOULD BE OFFSHORE IN THE NEXT FEW HOURS.
A SECOND SUBTROPICAL JET DISTURBANCE WILL MOVE THROUGH THE SOUTHERN
MS VALLEY THIS AFTERNOON. OUR OFFSHORE WARM FRONT WILL BE DRAWN
INLAND TODAY BY SURFACE PRESSURE FALLS OCCURRING AHEAD OF THIS
DISTURBANCE. WITH SEVERAL HOURS OF MOSTLY SUNNY SKIES EXPECTED THIS
MORNING THIS SHOULD ALLOW TEMPERATURES TO RISE INTO THE 60S AND
LOWER 70S BY EARLY AFTERNOON...WARMEST SOUTH OF FLORENCE AND CONWAY.
DURING THE MID AND LATE AFTERNOON MOISTURE WILL INCREASE FROM THE
WEST BETWEEN 850 AND 700 MB. COUPLED WITH MODEST ISENTROPIC LIFT
ALONG THE 295K THETA SURFACE THIS COULD PRODUCE ISOLATED SHOWERS.
POPS ARE LIMITED TO 20 PERCENT AND MAINLY FOR COASTAL LOCATIONS.
THIS EVENING THE BEST PRESSURE FALLS WILL SHIFT OFFSHORE AS A MUCH
STRONGER POLAR JET DISTURBANCE APPROACHES FROM THE NORTHWEST. THIS
WILL TAKE THE WARM FRONT ACROSS EAST-CENTRAL NORTH CAROLINA AND PUSH
IT SOUTHWARD AS A COLD FRONT BEHIND A DEEPENING SURFACE LOW
OFFSHORE...WITH COOLER AIR SURGING SOUTHWARD TO THE SANTEE RIVER
OVERNIGHT. ISENTROPIC FIELDS INDICATE LITTLE POTENTIAL FOR
PRECIPITATION DURING THE EVENING HOURS...HOWEVER INCREASING LIFT
AGAIN ALONG THE 295K THETA SURFACE VERY LATE TONIGHT SHOULD PRODUCE
AN AREA OF SHOWERS ACROSS SOUTH CAROLINA SPREADING TO THE NC/SC
COAST BY DAYBREAK.
BOTH THE 06Z GFS AND NAM LOOK WARMER WITH DAYTIME TEMPS TODAY THAN
THEIR 00Z COUNTERPARTS DID. THE INTERMODEL DIFFERENCES BETWEEN THE
NEW GFS AND NAM HAVE DECREASED RELATIVE TO THE LARGER DIFFERENCES
DISPLAYED ON THE 00Z RUNS WHERE THE GFS APPEARED MUCH TOO COLD.
BASED ON THIS TREND AND THE LATEST FEW RUNS OF THE RUC I HAVE RAISED
HIGH TEMP FORECASTS TODAY...EXPANDING THE AREA OF LOWER 70S IN THE
KINGSTREE-GEORGETOWN-CONWAY AREA THIS AFTERNOON. UPPER 60S ARE
FORECAST FOR MOST AREAS EAST OF I-95 AND SOUTH OF ELIZABETHTOWN.
LOWER TO MID 60S ARE STILL EXPECTED NORTH OF FLORENCE...DILLON...
ELIZABETHTOWN AND WATHA.
FOR TONIGHT: THE 00Z NAM MODEL APPEARS TO HAVE A BETTER HANDLE ON
THE DEVELOPMENT AND MOVEMENT OF THE WARM FRONT TODAY AND THE
OFFSHORE LOW TONIGHT. THE NAM`S MAX/MIN TEMPERATURES ALSO APPEAR
BETTER THAN THE GFS... ALTHOUGH IT IS CURIOUS WHY BOTH THE NAM AND
GFS MOS PRODUCTS ARE SO COOL WITH HIGHS TODAY GIVEN RAW MODELS
RUNNING SEVERAL DEGREES WARMER. MY FORECAST HIGHS ARE WARMER THAN
NAM OR GFS MOS... PARTICULARLY NEAR THE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...COLD FRONT WILL BE DRAPED ALONG OR JUST SOUTH
AND OFFSHORE OF THE CWA AT THE START OF THE PERIOD. MOST DIFFICULT
PART OF THE FORECAST WILL BE HOW THE INTERACTION OF THIS BOUNDARY
AND SOME ENHANCED MOISTURE RETURN WILL AFFECT THE CWA WITH RAINFALL
ON WEDNESDAY. THE COLD FRONT WILL MOVE ONLY VERY SLOWLY SOUTHWARD AS
THE REGION REMAINS BENEATH THE BASE OF THE EASTERN TROUGH...THUS
FLOW BECOMES NEARLY BOUNDARY-PARALLEL ON WEDNESDAY. AS THIS FRONT
STALLS NEAR THE AREA...MOISTURE INCREASES ALONG IT...AND SOME WEAK
LIFT DUE TO MID-LEVEL IMPULSES WILL TRY TO SPAWN SOME POST-FRONTAL
RAINFALL ACROSS THE CWA. NAM/GFS ARE WETTER AND IN BETTER AGREEMENT
THAN THE ECMWF...SO WILL LEAN MORE ON THESE MODELS FOR PRECIP
POTENTIAL ON WEDNESDAY. THE BEST CHANCES FOR PRECIP WILL BE ALONG
THE SE THIRD OF THE CWA...CLOSEST TO THE BOUNDARY AND WHERE
ISENTROPIC LIFT FROM 290-300K IS FOCUSED...BUT SREF PROBS SUGGEST AT
LEAST 60% 12-HR CHANCE OF 0.01 QPF ACROSS THE ENTIRE CWA. INHERITED
POP HAS LIKELY ACROSS THE EAST WITH HIGH-CHC WEST...AND WILL BUMP
THESE NUMBERS BUT KEEP WITHIN THE SAME CATEGORIES FOR WEDNESDAY.
HIGHEST CHANCES WILL BE WED MORNING INTO THE AFTN...DROPPING FROM NW
TO SE THROUGH THE EVE AS THE FRONT DRIFTS SLOWLY AWAY AND THE
MID-LEVEL IMPULSE PUSHES EASTWARD.
WHILE THE WEAK CAA...CLOUDS...AND RAIN WILL KEEP TEMPS WEDNESDAY
WELL BELOW NORMAL...AROUND 50 FOR HIGHS...SKY CONDITIONS WILL CLEAR
RAPIDLY WED NIGHT. AT THE SAME TIME...HIGH PRESSURE FROM THE WEST
WILL CONTINUE TO RIDGE TOWARDS THE AREA. A RELATIVELY WEAK PRESSURE
GRADIENT WED NIGHT WILL LEAVE ONLY LIGHT NORTH WINDS AHEAD OF THIS
HIGH PRESSURE...WHICH COMBINED WITH CLEARING SKY CONDITIONS WILL
CREATE A COLD NIGHT INTO THU MORNING...AND EXPECT NEARLY THE ENTIRE
AREA TO FALL BELOW FREEZING...WITH MID 20S POSSIBLE IN THE TYPICALLY
COLDER SPOTS.
SUBTLE AIR MASS MODIFICATION OCCURS THURSDAY THANKS TO SURFACE HIGH
PRESSURE RIDGE AXIS BULGING UP TOWARDS THE MID-ATLANTIC. THIS WILL
BE SOMEWHAT OFFSET BY CONTINUED LOW THICKNESSES SOUTH OF THE COLD 5H
VORTEX ACROSS NEW ENGLAND...AND THUS WHILE THURSDAY WILL BE WARMER
THAN WEDNESDAY...TEMPS WILL STAY BELOW NORMAL...RISING ONLY INTO THE
MID 50S...WITH A FEW UPPER 50S POSSIBLE NEAR THE SOUTH SANTEE RIVER.
A RENEWED SURGE OF COLD AIR IS NOW PROGGED FOR THURSDAY NIGHT AS A
SECONDARY DRY COLD FRONT CROSSES AHEAD OF ARCTIC HIGH PRESSURE
DROPPING OUT OF CANADA. THIS WILL CREATE A COLD AND BREEZY NIGHT
THURSDAY NIGHT...AS LOW DROP ONCE AGAIN TO FREEZING OR BELOW...WITH
EVEN COLDER APPARENT TEMPS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...COLD TO START THE EXTENDED AS ARCTIC HIGH
PRESSURE DEVELOPS INTO A WEDGE ALONG THE EAST COAST. THIS WILL
CREATE COOL NE WINDS INTO THE FIRST HALF OF THE WKND...WITH TEMPS
REMAINING SOLIDLY BELOW CLIMO FOR THE END OF FEBRUARY. WHILE
GUIDANCE HAS BEEN ADVERTISING A SOUTHERN STREAM LOW FOR SEVERAL DAYS
NOW...THIS FEATURE HAS BECOME LESS INTENSE...AND NOW THE SURFACE
REFLECTION HAS BASICALLY DISAPPEARED THANKS TO WEAKER MID-LEVEL
FORCING AND BAROCLINIC INSTABILITY. STILL...THERE IS AT LEAST DECENT
POTENTIAL FOR SOME SHOWERS ON SATURDAY BENEATH THE MID-LEVEL
IMPULSE...BUT OVERALL QPF LOOKS LIMITED. ADDITIONALLY...WITH THE
COOL AIR IN PLACE WITHIN THE WEDGE...THIS OVERRUNNING SCENARIO MAY
PROMOTE A MIXED P-TYPE EVENT...ESPECIALLY WELL INLAND. TEMPS WILL BE
MARGINAL AT-BEST FOR ANYTHING OTHER THAN THAT LIQUID...AND WILL KEEP
-RW AS WX TYPE FOR NOW...BUT THERE IS AT LEAST A SMALL CHANCE FOR
SOME FROZEN PRECIP FRIDAY NIGHT/SAT AM.
GUIDANCE DIFFERS CONSIDERABLY INTO THE BEGINNING OF NEXT WEEK. GFS
BREAKS DOWN THE WEDGE QUICKLY AS MID-LEVEL RIDGING
DEVELOPS...CENTERED OFF THE FLORIDA COAST. ECMWF SHOWS A SIMILAR
PROCESS BUT WITH A SLOWER TEMPORAL EVOLUTION. THIS CAUSES 15+ DEGREE
TEMP DIFFERENCES IN THE FORECASTS FOR NEXT WEEK. A QUICK GLANCE AT
SOME OF THE ENSEMBLES SUGGESTS THAT THE OP-GFS IS WELL TOO WARM AS
IT IS ON THE HIGH SIDE OF ALL ITS ENSEMBLE THICKNESSES. STILL...THE
UPPER PATTERN FAVORS WEDGE BREAKDOWN AND AT LEAST A MARGINAL WARMUP
SUN/MON...SO WILL BUMP TEMPS TOWARDS AND ABOVE CLIMO FOR EARLY NEXT
WEEK. A MORE IMPRESSIVE LOW PRESSURE SYSTEM MAY APPROACH
MONDAY...AND WILL KEEP INHERITED CHC POP ATTM.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
OF 12Z...CURRENTLY VFR CONDITIONS PREVAIL ACROSS THE CWA WITH MID TO
HIGH CLOUDS MOVING OVERHEAD. LIGHT AND VARIABLE WINDS WILL SHIFT TO
THE SOUTH AND THEN SOUTHWEST BY MIDDAY AS A DEVELOPING WARM FRONT
OFFSHORE MOVES NORTHWARD. TIME-HEIGHT ANALYSIS SHOWS INCREASING LOW
TO MID LEVEL MOISTURE THIS AFTERNOON...AND WILL KEEP VCSH FOR THE
COASTAL SITES AS AN ISOLATED SHOWER CANNOT BE RULED OUT. EXPECT
SOUTHWEST WINDS AROUND 10 KTS THROUGH THE AFTERNOON HOURS. THIS
PATTERN WILL QUICKLY CHANGE THIS EVENING AS LOW PRESSURE DEVELOPS
OFF THE NC/VA COAST. THE WINDS OVERNIGHT WILL BECOME N-NE ON THE
BACK SIDE OF THIS LOW. LOW CLOUDS AND RAIN CHANCES WILL INCREASE
TOWARD DAYBREAK AS THE COLD FRONT REMAINS DRAPED JUST TO OUR SOUTH.
KFLO/KLBT MAY SEE MVFR CIGS DEVELOP BY THE END OF THE VALID PERIOD
AS A REGION OF ISENTROPIC LIFT AND -RA SPREADS INTO OUR INLAND ZONES.
EXTENDED OUTLOOK...RAIN WITH MVFR CIGS ON WEDNESDAY. VFR THURSDAY
AND FRIDAY. CHANCE OF RAIN/MVFR ON SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM TUESDAY...SEASONS WILL CHANGE AT LEAST TWICE ACROSS
THE COASTAL WATERS TODAY AS A FRONT WAVERS ACROSS THE AREA. A WARM
FRONT DEVELOPING ACROSS THE COASTAL WATERS SHOULD PUSH INLAND LATER
THIS MORNING...WITH EAST WINDS VEERING TO THE SOUTH. WINDS
SPEEDS WILL INCREASE TO 10-15 KNOTS AS DIRECTIONS CONTINUE TO VEER
SOUTHWESTERLY DURING THE AFTERNOON. THIS VEERING SHOULD BE IN
RESPONSE TO FALLING PRESSURES AS LOW PRESSURE DEVELOPS ALONG THE
COAST TODAY...THEN OFFSHORE THIS EVENING. CLOCKWISE WINDS BLOWING
AROUND THIS LOW SHOULD PUSH THE WARM FRONT BACK SOUTHWARD AS A COLD
FRONT THIS EVENING. THE FRONT MAY PRESS ALL THE WAY TO THE SANTEE
RIVER...WITH NORTH TO NORTHEAST WINDS STRONGEST ACROSS THE NC WATERS
CLOSEST TO THE POSITION OF THE LOW.
SEAS CURRENTLY RANGE FROM 2-3 FEET WITH DOMINANT PERIODS AROUND 9
SECONDS IN SOUTHEAST SWELL. A SMALL SHORT PERIOD CHOP WILL DEVELOP
IN THE SOUTH-SOUTHWEST WIND BEHIND THE WARM FRONT...WITH CONFUSED
SEAS FOR A PERIOD THIS EVENING AS WINDS SHIFT TO THE NORTH AS THE
FRONT IS PUSHED ACROSS AGAIN. TOTAL SEA HEIGHTS WILL PROBABLY NOT
EXCEED 4 FEET AT ANY POINT THROUGH TONIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...COLD FRONT MOVING OFFSHORE AT THE START OF
THE PERIOD WILL DRIFT SOUTH OF THE AREA INTO THURSDAY...WITH
NORTHERLY WINDS INCREASING TO 15-20 KTS...AND REMAINING AT THESE
SPEEDS INTO THURSDAY MORNING. THESE WINDS WILL EASE AND BACK TO THE
SW ON THURSDAY AS A RIDGE OF HIGH PRESSURE BRIEFLY ENVELOPS THE
AREA...BUT WILL QUICKLY RETURN TO THE NORTH AT 15-20 KTS AT THE END
OF THE PERIOD AS A SECOND COLD SURGE MOVES ACROSS THE WATERS. EVEN
THOUGH WINDS WILL BE GUSTY ON WEDNESDAY...THE NORTHERLY COMPONENT
WILL INHIBIT SUBSTANTIAL WAVE GROWTH...AND THUS SEAS WILL RISE TO
PEAK AT 3-5 FT WEDNESDAY EVE...BEFORE FALLING BACK TO 1-3 FT DURING
THURSDAY. RENEWED AMPLIFICATION IS EXPECTED AT THE END OF THE SHORT
TERM AS THE WINDS ONCE AGAIN RISE FROM THE NORTH...WITH WAVE HEIGHTS
BECOMING 2-4 FT BY FRIDAY MORNING.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 300 AM TUESDAY...DEVELOPING WEDGE OF HIGH PRESSURE EXTENDING
DOWN THE EAST COAST WILL CREATE A PROLONGED PERIOD OF NE WINDS OVER
THE COASTAL WATERS...AND CAUTIONARY STATEMENTS MAY BE REQUIRED ON
FRIDAY. STRENGTHENING WEDGE FRIDAY FORCES A PINCHED PRESSURE
GRADIENT...AND NE WINDS RISE TO AROUND 20 KTS ALL OF
FRIDAY...DRIVING SEAS UP TO 4-5 FT...EXCEPT SW OF BRUNSWICK COUNTY
WHERE THE WAVE SHADOW REGION WILL PERMIT ONLY MUCH SMALLER WAVE
HEIGHTS. GRADIENT WILL EASE AT LEAST MARGINALLY ON
SATURDAY...ALLOWING NE WINDS TO FALL TO 10-15 KTS...WITH SEAS
FOLLOWING TO 2-4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
638 AM CST TUE FEB 25 2014
.UPDATE...
ISSUED AT 637 AM CST TUE FEB 25 2014
THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE REQUIRED.
ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN FORECAST CONCERN WILL BE WIND CHILL HEADLINES. EARLY
MORNING SURFACE ANALYSIS SHOWS SURFACE HIGH PRESSURE STRETCHING
FROM EASTERN MONTANA INTO SOUTHEAST SOUTH DAKOTA. TEMPERATURES
EARLY THIS MORNING WERE IN THE SINGLE DIGITS AND TEENS BELOW ZERO
WITH WINDS OF 5 TO 10 MPH. THIS HAS DROPPED WIND CHILLS INTO
ADVISORY LEVELS ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA...THE EXCEPTION BEING FAR WEST CENTRAL NORTH DAKOTA WHERE
WINDS REMAIN WEAKEST.
THE FAR SOUTHWEST HAS ALSO SEEN AN INCREASE IN MID AND HIGH LEVEL
CLOUDS EARLY THIS MORNING HELPING TEMPERATURES GAIN A FEW DEGREES
OVER THE PAST COUPLE OF HOURS. NOT CONFIDENT THAT TREND WILL
CONTINUE SINCE THE LATEST HRRR SUGGESTS THE CLOUDS WILL SINK SOUTH
AGAIN THIS MORNING. OVERALL...THE WIND CHILL HEADLINE IS STILL
SUPPORTED BY THE LATEST OBSERVATIONS AND WILL NOT MAKE ANY CHANGES
TO IT.
WIND CHILLS WILL AGAIN BE THE MAIN CONCERN TONIGHT WITH LOWS OF 5
TO 15 BELOW AND WIND SPEEDS OF 10 MPH...INCREASING TO NEAR 20 MPH
OVERNIGHT. THIS AGAIN DROPS WIND CHILLS IN THE 25 TO 35 BELOW
RANGE ACROSS MUCH OF THE NORTH AND EAST. WILL KEEP THINGS SIMPLE
AND NOT ISSUE ADDITIONAL HEADLINES...BUT EXPECT LATER SHIFTS WILL
LIKELY NEED TO CONSIDER THAT POSSIBILITY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN HIGHLIGHTS FOR THE EXTENDED WILL BE THE WELL BELOW NORMAL
TEMPERATURES AND SNOW CHANCES THIS WEEKEND. MODELS ARE IN FAIRLY
GOOD AGREEMENT SO USED A BLEND FOR THIS PACKAGE.
WEDNESDAY STILL LOOKS TO BE THE WARMEST DAY OF THE WEEK WITH HIGHS
GENERALLY FROM THE TEENS EAST TO THE MID 20S SOUTHWEST.
HOWEVER...IT WILL ALSO BE THE WINDIEST DAY OF THE PERIOD AS HIGH
PRESSURE SURGES INTO THE REGION. SNOW FROM MONDAY`S EVENT COMBINED
WITH THESE WINDS SHOULD GENERATE PATCHY TO AREAS OF BLOWING
SNOW...MAINLY ON WEDNESDAY AFTERNOON. WINDS WILL DECREASE RAPIDLY
WEDNESDAY NIGHT AS HIGH PRESSURE SETTLES ACROSS THE REGION. COLD
AND DRY CONDITIONS WILL CONTINUE ACROSS THE REGION THURSDAY AS
HIGH PRESSURE SHIFTS EAST OF THE REGION.
BY FRIDAY...A REINFORCING COLD FRONT WILL PUSH THROUGH THE
NORTHERN PLAINS...WITH A BAROCLINIC ZONE SETTING UP OVER
SOUTHWESTERN NORTH DAKOTA. THIS WILL GENERATE A SLIGHT CHANCE FOR
SNOW OVER SOUTHWESTERN NORTH DAKOTA FRIDAY INTO FRIDAY NIGHT.
A SHORTWAVE ROTATING OVER THE NORTHERN ROCKIES AND INTO THE
NORTHERN PLAINS THIS WEEKEND IS PROGGED TO LIFT THE SNOW CHANCES
NORTH SATURDAY AND SUNDAY. HOWEVER...GIVEN THE WEAK UPPER LEVEL
FORCING...SNOW AMOUNTS ARE EXPECTED TO REMAIN FAIRLY LIGHT.
AS THE UPPER WAVE DEPARTS THE STATE MONDAY...DRY CONDITIONS ARE
EXPECTED BY THE BEGINNING OF THE NEXT WORK WEEK. COLD TEMPERATURE
ARE FORECAST TO CONTINUE AS WELL WITH HIGHS IN THE SINGLE DIGITS
ABOVE ZERO.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 637 AM CST TUE FEB 25 2014
EARLY MORNING SATELLITE IMAGERY SHOWS VFR CONDITIONS ACROSS NORTH
DAKOTA. WILL CARRY VFR AT ALL TERMINAL LOCATIONS...HOWEVER HAVE
SOME CONCERN CLOUDS COULD DEVELOP TODAY AS A BAND OF H925-H85
MOISTURE MOVES ACROSS NORTH DAKOTA. THE HRRR EVEN SUGGESTS THERE
IS SOME POTENTIAL FOR MVFR CEILINGS FROM LATE MORNING INTO THE
AFTERNOON ACROSS THE WEST...POSSIBLY IMPACTING WILLISTON AND
DICKINSON. HAVE FORECAST SCATTERED CLOUDS AROUND 3500 FT...BUT DID
NOT NOT CARRY A CEILING SINCE FORECAST SOUNDINGS SUGGEST ANY
AVAILABLE MOISTURE SHOULD BE SHALLOW. WINDS WILL START LIGHT...BUT
WILL INCREASE FROM FROM THE NORTHWEST LATER THIS MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST /9 AM MST/ THIS MORNING FOR
NDZ001>005-009>013-018>023-025-033>037-040>048-050-051.
&&
$$
UPDATE...TM
SHORT TERM...CK
LONG TERM...TM
AVIATION...CK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
855 AM EST TUE FEB 25 2014
.SYNOPSIS...
UPPER LEVEL DISTURBANCE CROSSES FIRST THING THIS MORNING. ARCTIC
FRONTS CROSS TONIGHT AND THURSDAY. WEAK LOW PRESSURE CROSSES ON
SATURDAY. A STRONGER LOW PRESSURE SYSTEM APPROACHES ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
945 AM UPDATE...
OVERACHIEVER THIS MORNING WITH NUMEROUS 2 INCH REPORTS WITH
NUMEROUS ACCIDENTS ACROSS SE OH AND N WV. ISSUED A WINTER WX
ADVISORY FOR 1 TO 3 INCHES OF SNOW AND HIGH IMPACT TO TRAVEL GIVEN
MORNING COMMUTE. SOME LOCAL HIGHER AMOUNTS DEFINITELY POSSIBLE
ALONG US 33 ROUTE AND ALONG I79 CORRIDOR. ISSUED SPS I64 COUNTIES
IN NE KY/C WV FOR UP TO AN INCH JUST N OF I64 CORRIDOR. NEAR TERM
MODELS HAVE LOW BALLED THE QPF COMPARED TO WHAT HAS ACTUALLY OCCUR
ED. THEY ALSO HAVE NOT BEEN FAR ENOUGH S WITH TRACK OF THIS BAND
OF SN. HOPING THIS TRACKS MORE E THAN S NEXT HR TO KEEP IT OUT OF
HTS AND CRW. ALL OF THIS SHOULD TAPER OFF BY 16Z.
PREV DISCN...
UPPER LEVEL SYSTEM IMPACTING NRN PORTION OF THE AREA EARLY THIS
MORNING AS RR ENTRANCE REGION OF JET AND FRONTOGENETIC FORCING CROSS
IN THE BAROCLINIC ZONE AROUND 12Z. AREA RADAR SHOWED THAT
PRECIPITATION WAS NOT YET REACHING THE GROUND SAVE FOR THE HIGHER
TERRAIN OF NRN WV. THIS SHOULD CHANGE TOWARD DAWN AS LOW LEVELS
EVENTUALLY MOISTEN.
WITH THE DRY AIR AT THE START...AND THE FAST PACE OF THE MI AND
UPPER LEVEL SYSTEM...AMNTS WILL BE LIMITED...MAINTAINED PREVIOUS
FCST OF LESS THAN AN INCH NRN LOWLANDS...1-2 INCHES IN THE NRN WV
MOUNTAINS WHERE THE SNOW WAS ALREADY REACHING THE GROUND.
ARCTIC FRONT DRIVEN BY UPPER LEVEL S/W TROUGH AND A MUCH MORE STOUT
JET MAX...CROSSES TONIGHT. UPSLOPE SNOW WILL SET UP OVERNIGHT IN
THE COLD ADVECTION BEHIND THE FRONT. FRONTOGENETIC FORCING EARLY ON
MAY GENERATE AN AREA OF SNOW UPSTREAM THAT MOVES INTO SRN PORTIONS
OF THE FCST AREA FROM THE W. IF THE POTENTIAL FOR THIS FEATURE TO
PRODUCE ACCUMULATING SNOW INCREASES...THEN AN ADVISORY FOR SNOW MAY
BE NEEDED FOR THE SRN LOWLANDS. HWO MENTION CONTINUES. THX JKL AND
MRX FOR COORD ON THIS.
BLENDED IN MET FOR HIGHS TODAY AND BIAS CORRECTED MET FOR LOWS
TONIGHT...CONTINUING THE COLDER TREND. SLOWED FALL OF TEMPERATURES
TONIGHT UNTIL LATER AS THE FRONT GOES BY.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
TRANSITION TO A QUIETER...BUT MUCH COLDER PATTERN IN THE SHORT TERM.
INITIAL COLD FRONT PUSHING EAST THROUGH CWA AT BEGINNING OF
PERIOD...WITH LIGHT SNOW SHOWERS LINGERING...MAINLY ACROSS MOUNTAIN
ZONES FOR REMAINDER OF DAY WEDNESDAY...WITH ONLY LIGHT ADDITIONAL
ACCUMULATIONS EXPECTED. THIS WILL BE THE FIRST SHOT OF COLD
AIR...WITH 850MB TEMPS DIPPING TO AROUND -16C THURSDAY MORNING. MADE
LITTLE CHANGES TO PREVIOUS LOW TEMPERATURE FORECAST THURSDAY
MORNING...WHICH PLACES MANY LOWLAND COUNTIES IN THE LOWER
TEENS...AND SINGLE DIGITS TO BELOW ZERO ACROSS THE MOUNTAINS. A
SECONDARY FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA ON THURSDAY.
BULK OF PRECIPITATION WILL REMAIN TO THE NORTH OF THE CWA...ALTHOUGH
NORTHERN ZONES COULD SEE A FEW FLURRIES WITH PASSAGE. WITH FRONTAL
PASSAGE...MUCH COLDER AIR WILL MOVE INTO THE AREA...WITH 850MB TEMPS
DIPPING DOWN TO AROUND -22C. AS A RESULT...ELECTED TO LOWER
TEMPERATURES SIGNIFICANTLY FRIDAY MORNING FROM PREVIOUS
FORECAST...PLACING MANY MOUNTAINOUS LOCATIONS BELOW ZERO...WITH
SINGLE DIGITS ACROSS THE LOWLANDS...CONSIDERING COLDER AIR
MASS...ALONG WITH FAVORABLE RADIATIONAL COOLING CONDITIONS.
WITH THE COLDER AIR IN PLACE...NORTHERN MOUNTAIN ZONES MAY NEED WIND
CHILL HEADLINES BOTH THURSDAY AND FRIDAY MORNINGS. AT THIS
POINT...DOESNT APPEAR TO BE NECESSARY ACROSS LOWLANDS. WILL CONTINUE
TO HIGHLIGHT IN THE HWO.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE WILL BE IN CONTROL THURSDAY NIGHT INTO FRIDAY WITH DRY
AND COOL CONDITIONS.
MODELS BRING A MID LEVEL SHORTWAVE EMBEDDED IN THE SOUTHERN STREAM
FRIDAY NIGHT INTO SATURDAY. ADJUSTED CHANCE POPS ACROSS THE AREA
WITH THIS FEATURE. WITH THE GFS AND ECMWF SHOWING FREEZING LINE AT
H85 ACROSS AND SOUTH OF OUR CWA...WONT BE SURPRISED TO SEE PCPN
FALLING AS SNOW. THIS SHORTWAVE EXITS SATURDAY WITH LINGERING SNOW
SHOWERS OVER THE EASTERN MOUNTAINS THROUGH AT LEAST SATURDAY
AFTERNOON.
BROAD SURFACE HIGH PRESSURE BUILD FROM THE UPPER CENTRAL
PLAINS...SOUTHEAST ACROSS THE OH VALLEY INTO WV SATURDAY NIGHT INTO
SUNDAY. WITH ZONAL FLOW EXPECTED ALOFT...THE AREA SHOULD STAY
RELATIVELY DRY SATURDAY NIGHT INTO SUNDAY.
THE FORECAST CHALLENGE ARRIVE WITH THE NEXT LOW PRESSURE SYSTEM.
BOTH THE GFS AND ECMWF BRING A SURFACE LOW PRESSURE CROSSING OUR CWA
DIAGONALLY FROM SOUTHWEST TO NORTHEAST SUNDAY OR MONDAY. THE PROBLEM
IS THAT THE ECMWF IS ABOUT 24 HOURS FASTER THAN THE GFS. TRIED TO
COMPROMISE IN BETWEEN BOTH SOLUTION IN TERMS OF POPS. EITHER
WAY...STRONG SOUTHWEST FLOW IS EXPECTED AHEAD OF THE LOW TO BRING
WARM AIR ADVECTION AND STRONG GUSTY WINDS. BOTH MODELS INDICATE 60
TO 70 KNOTS AT H85. AS MANY SPRING LOW SYSTEMS BRINGING STRONG
SOUTHWEST FLOW...EXPECT WARMER THAN GUIDANCE TEMPERATURES WITH THIS
SYSTEM. WENT WITH HPC WHICH IS WARMER THAN ALL AVAILABLE GUIDANCE
WITH THIS LOW. IN TERMS OF POPS...LEANED TOWARDS THE GFS SLOWER
SOLUTION AND INTRODUCED LIKELY POPS ON MONDAY.
TWEAKED HPC GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
AN UPPER LEVEL SYSTEM WAS BRINGING SNOW FROM THE MIDDLE OHIO VALLEY
EWD TO THE NORTHERN WV MOUNTAINS...AFFECTING THE NORTHERN 3 TAF
SITES...EARLY THIS MORNING. SNOW WILL CONTINUE TO BRING IFR VSBY AT
TIMES THIS MORNING. EXPECT 3-4 HOURS OF IFR VSBY IN SNOW...EXCEPT
UP TO 6 HRS EKN...IMPROVING TO MVFR AROUND 18Z TODAY THERE. EXPECT
MAINLY MVFR CIGS ALTHOUGH BRIEF IFR CIGS ARE POSSIBLE. FARTHER
S...EXPECT VFR WITH STRATOCU 4-5 KFT.
RETURN TO VFR N SHOULD BE AROUND MIDDAY...EXCEPT EKN...WHERE
IMPROVEMENT TO VFR VSBY TAKES UNTIL AROUND 20Z TODAY...MVFR STRATOCU
MAY HANG ON THERE THROUGHOUT THE TAF PERIOD. FARTHER S...STRATOCU
VANISHES LATER THIS AFTERNOON BUT RETURNS LATE TONIGHT...AS AN
ARCTIC FRONT ARRIVES FROM THE NW. THIS SHOULD RESULT IN MVFR IN
SNOW ALL SITES E OF THE OHIO RIVER BY DAWN WED...EVEN IFR AT BKW.
LIGHT W TO NW SFC FLOW BECOMES A BIT GUSTY DURING THE DAY
TODAY...BEFORE DIMINISHING A BIT THIS EVENING. SFC FLOW WILL
INCREASE AGAIN BEHIND THE COLD FRONT OVERNIGHT TONIGHT. LIGHT TO
MODERATE W FLOW ALOFT BECOMES LIGHT W TUE AFTERNOON...AND THEN
BEGINS TO STRENGTHEN FROM THE NW OVERNIGHT TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF LIGHT SNOW AND ASSOCIATED
CATEGORY CHANGES MAY VARY. IFR CIGS COULD NOT BE RULED OUT N THIS
MORNING. EKN CIGS MAY IMPROVE TO VFR FOR A TIME THIS EVENING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY M M M M M M H H H H H H
PKB CONSISTENCY L L H H H H H H H H H H
CKB CONSISTENCY H H L H L H H H H H H H
AFTER 12Z WEDNESDAY...
BRIEF IFR POSSIBLE INTO EARLY WEDNESDAY IN SNOW BEHIND AN ARCTIC
FRONT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
WVZ007>011-016>020-028>032-038>040-046-047.
OH...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
OHZ075-076-083>087.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM/30
SHORT TERM...SL
LONG TERM...ARJ
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
555 AM EST TUE FEB 25 2014
.SYNOPSIS...
UPPER LEVEL DISTURBANCE CROSSES FIRST THING THIS MORNING. ARCTIC
FRONTS CROSS TONIGHT AND THURSDAY. WEAK LOW PRESSURE CROSSES ON
SATURDAY. A STRONGER LOW PRESSURE SYSTEM APPROACHES ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
545 AM UPDATE...
ADJUSTED POPS SLIGHTLY SWD / EARLIER AND HAVE SLIGHTLY HIGHER SNOW
AMNTS THIS MORNING. GILMER CO SCHOOLS REPORTED A COATING AT 415
AM. FCST OTHERWISE ON TRACK.
PREV DISCN...
UPPER LEVEL SYSTEM IMPACTING NRN PORTION OF THE AREA EARLY THIS
MORNING AS RR ENTRANCE REGION OF JET AND FRONTOGENETIC FORCING CROSS
IN THE BAROCLINIC ZONE AROUND 12Z. AREA RADAR SHOWED THAT
PRECIPITATION WAS NOT YET REACHING THE GROUND SAVE FOR THE HIGHER
TERRAIN OF NRN WV. THIS SHOULD CHANGE TOWARD DAWN AS LOW LEVELS
EVENTUALLY MOISTEN.
WITH THE DRY AIR AT THE START...AND THE FAST PACE OF THE MI AND
UPPER LEVEL SYSTEM...AMNTS WILL BE LIMITED...MAINTAINED PREVIOUS
FCST OF LESS THAN AN INCH NRN LOWLANDS...1-2 INCHES IN THE NRN WV
MOUNTAINS WHERE THE SNOW WAS ALREADY REACHING THE GROUND.
ARCTIC FRONT DRIVEN BY UPPER LEVEL S/W TROUGH AND A MUCH MORE STOUT
JET MAX...CROSSES TONIGHT. UPSLOPE SNOW WILL SET UP OVERNIGHT IN
THE COLD ADVECTION BEHIND THE FRONT. FRONTOGENETIC FORCING EARLY ON
MAY GENERATE AN AREA OF SNOW UPSTREAM THAT MOVES INTO SRN PORTIONS
OF THE FCST AREA FROM THE W. IF THE POTENTIAL FOR THIS FEATURE TO
PRODUCE ACCUMULATING SNOW INCREASES...THEN AN ADVISORY FOR SNOW MAY
BE NEEDED FOR THE SRN LOWLANDS. HWO MENTION CONTINUES. THX JKL AND
MRX FOR COORD ON THIS.
BLENDED IN MET FOR HIGHS TODAY AND BIAS CORRECTED MET FOR LOWS
TONIGHT...CONTINUING THE COLDER TREND. SLOWED FALL OF TEMPERATURES
TONIGHT UNTIL LATER AS THE FRONT GOES BY.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
TRANSITION TO A QUIETER...BUT MUCH COLDER PATTERN IN THE SHORT TERM.
INITIAL COLD FRONT PUSHING EAST THROUGH CWA AT BEGINNING OF
PERIOD...WITH LIGHT SNOW SHOWERS LINGERING...MAINLY ACROSS MOUNTAIN
ZONES FOR REMAINDER OF DAY WEDNESDAY...WITH ONLY LIGHT ADDITIONAL
ACCUMULATIONS EXPECTED. THIS WILL BE THE FIRST SHOT OF COLD
AIR...WITH 850MB TEMPS DIPPING TO AROUND -16C THURSDAY MORNING. MADE
LITTLE CHANGES TO PREVIOUS LOW TEMPERATURE FORECAST THURSDAY
MORNING...WHICH PLACES MANY LOWLAND COUNTIES IN THE LOWER
TEENS...AND SINGLE DIGITS TO BELOW ZERO ACROSS THE MOUNTAINS. A
SECONDARY FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA ON THURSDAY.
BULK OF PRECIPITATION WILL REMAIN TO THE NORTH OF THE CWA...ALTHOUGH
NORTHERN ZONES COULD SEE A FEW FLURRIES WITH PASSAGE. WITH FRONTAL
PASSAGE...MUCH COLDER AIR WILL MOVE INTO THE AREA...WITH 850MB TEMPS
DIPPING DOWN TO AROUND -22C. AS A RESULT...ELECTED TO LOWER
TEMPERATURES SIGNIFICANTLY FRIDAY MORNING FROM PREVIOUS
FORECAST...PLACING MANY MOUNTAINOUS LOCATIONS BELOW ZERO...WITH
SINGLE DIGITS ACROSS THE LOWLANDS...CONSIDERING COLDER AIR
MASS...ALONG WITH FAVORABLE RADIATIONAL COOLING CONDITIONS.
WITH THE COLDER AIR IN PLACE...NORTHERN MOUNTAIN ZONES MAY NEED WIND
CHILL HEADLINES BOTH THURSDAY AND FRIDAY MORNINGS. AT THIS
POINT...DOESNT APPEAR TO BE NECESSARY ACROSS LOWLANDS. WILL CONTINUE
TO HIGHLIGHT IN THE HWO.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE WILL BE IN CONTROL THURSDAY NIGHT INTO FRIDAY WITH DRY
AND COOL CONDITIONS.
MODELS BRING A MID LEVEL SHORTWAVE EMBEDDED IN THE SOUTHERN STREAM
FRIDAY NIGHT INTO SATURDAY. ADJUSTED CHANCE POPS ACROSS THE AREA
WITH THIS FEATURE. WITH THE GFS AND ECMWF SHOWING FREEZING LINE AT
H85 ACROSS AND SOUTH OF OUR CWA...WONT BE SURPRISED TO SEE PCPN
FALLING AS SNOW. THIS SHORTWAVE EXITS SATURDAY WITH LINGERING SNOW
SHOWERS OVER THE EASTERN MOUNTAINS THROUGH AT LEAST SATURDAY
AFTERNOON.
BROAD SURFACE HIGH PRESSURE BUILD FROM THE UPPER CENTRAL
PLAINS...SOUTHEAST ACROSS THE OH VALLEY INTO WV SATURDAY NIGHT INTO
SUNDAY. WITH ZONAL FLOW EXPECTED ALOFT...THE AREA SHOULD STAY
RELATIVELY DRY SATURDAY NIGHT INTO SUNDAY.
THE FORECAST CHALLENGE ARRIVE WITH THE NEXT LOW PRESSURE SYSTEM.
BOTH THE GFS AND ECMWF BRING A SURFACE LOW PRESSURE CROSSING OUR CWA
DIAGONALLY FROM SOUTHWEST TO NORTHEAST SUNDAY OR MONDAY. THE PROBLEM
IS THAT THE ECMWF IS ABOUT 24 HOURS FASTER THAN THE GFS. TRIED TO
COMPROMISE IN BETWEEN BOTH SOLUTION IN TERMS OF POPS. EITHER
WAY...STRONG SOUTHWEST FLOW IS EXPECTED AHEAD OF THE LOW TO BRING
WARM AIR ADVECTION AND STRONG GUSTY WINDS. BOTH MODELS INDICATE 60
TO 70 KNOTS AT H85. AS MANY SPRING LOW SYSTEMS BRINGING STRONG
SOUTHWEST FLOW...EXPECT WARMER THAN GUIDANCE TEMPERATURES WITH THIS
SYSTEM. WENT WITH HPC WHICH IS WARMER THAN ALL AVAILABLE GUIDANCE
WITH THIS LOW. IN TERMS OF POPS...LEANED TOWARDS THE GFS SLOWER
SOLUTION AND INTRODUCED LIKELY POPS ON MONDAY.
TWEAKED HPC GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AN UPPER LEVEL SYSTEM WAS BRINGING SNOW FROM THE MIDDLE OHIO VALLEY
EWD TO THE NORTHERN WV MOUNTAINS...AFFECTING THE NORTHERN 3 TAF
SITES...EARLY THIS MORNING. SNOW WILL CONTINUE TO BRING IFR VSBY AT
TIMES THIS MORNING. EXPECT 3-4 HOURS OF IFR VSBY IN SNOW...EXCEPT
UP TO 6 HRS EKN...IMPROVING TO MVFR AROUND 18Z TODAY THERE. EXPECT
MAINLY MVFR CIGS ALTHOUGH BRIEF IFR CIGS ARE POSSIBLE. FARTHER
S...EXPECT VFR WITH STRATOCU 4-5 KFT.
RETURN TO VFR N SHOULD BE AROUND MIDDAY...EXCEPT EKN...WHERE
IMPROVEMENT TO VFR VSBY TAKES UNTIL AROUND 20Z TODAY...MVFR STRATOCU
MAY HANG ON THERE THROUGHOUT THE TAF PERIOD. FARTHER S...STRATOCU
VANISHES LATER THIS AFTERNOON BUT RETURNS LATE TONIGHT...AS AN
ARCTIC FRONT ARRIVES FROM THE NW. THIS SHOULD RESULT IN MVFR IN
SNOW ALL SITES E OF THE OHIO RIVER BY DAWN WED...EVEN IFR AT BKW.
LIGHT W TO NW SFC FLOW BECOMES A BIT GUSTY DURING THE DAY
TODAY...BEFORE DIMINISHING A BIT THIS EVENING. SFC FLOW WILL
INCREASE AGAIN BEHIND THE COLD FRONT OVERNIGHT TONIGHT. LIGHT TO
MODERATE W FLOW ALOFT BECOMES LIGHT W TUE AFTERNOON...AND THEN
BEGINS TO STRENGTHEN FROM THE NW OVERNIGHT TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF LIGHT SNOW AND ASSOCIATED
CATEGORY CHANGES MAY VARY. IFR CIGS COULD NOT BE RULED OUT N THIS
MORNING. EKN CIGS MAY IMPROVE TO VFR FOR A TIME THIS EVENING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY M M L M M M M M M H H H
PKB CONSISTENCY M M M L L M H H H H H H
CKB CONSISTENCY M M M M M L M L H H H H
AFTER 12Z WEDNESDAY...
BRIEF IFR POSSIBLE INTO EARLY WEDNESDAY IN SNOW BEHIND AN ARCTIC
FRONT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM
SHORT TERM...SL
LONG TERM...ARJ
AVIATION...TRM
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
614 AM PST TUE FEB 25 2014
.SYNOPSIS...HIGH PRESSURE ALOFT CENTERED OVER THE PACIFIC NORTHWEST
WILL STRENGTHEN TODAY AS A DEEP LOW PRESSURE SYSTEM REMAINS WELL
OFFSHORE AND MUCH COLDER NORTH FLOW ALOFT RESIDES OVER THE NORTHERN
ROCKIES. OFFSHORE LOW-LEVEL FLOW THROUGH THE COLUMBIA GORGE WILL
CONTINUE THROUGH TONIGHT...THEN GRADUALLY WEAKEN WEDNESDAY. RESIDUAL
COLD AIR NEAR HOOD RIVER AND IN THE UPPER HOOD RIVER VALLEY TODAY
WILL MAINTAIN THREAT OF MIXED PRECIPITATION THIS MORNING. THE RIDGE
SHIFTS TO THE EAST WEDNESDAY AS AN UPPER LOW SWINGS TOWARD SOUTHWEST
OREGON. RAIN SPREADS INTO THE SOUTH ZONES WEDNESDAY EVENING THEN
EXPANDS NORTH WEDNESDAY NIGHT. A LOW PRESSURE AREA REMAINS PARKED OFF
THE NRN CALIFORNIA COAST THURSDAY AND FRIDAY WITH THE BEST THREAT OF
PRECIPITATION OVER THE SOUTH. UNSETTLED AND POSSIBLY QUITE COOL
WEATHER WILL RETURN FOR THE COMING WEEKEND.
&&
UPDATED MARINE DISCUSSION
.SHORT TERM...TUESDAY THROUGH THURSDAY...A RATHER COMPLEX LARGE-SCALE
PATTERN CONTINUES OVER THE PAC NW TODAY. THE MAIN FEATURES OF NOTE
EARLY THIS MORNING INCLUDE AN ELONGATED FRONTAL ZONE ASSOCIATED WITH
A LOW OUT NEAR 44N 145W AND A 500 MB RIDGE AXIS CENTERED OVER WRN
WASHINGTON AND OREGON. HOWEVER...THE RIDGE IS NOT STRONG ENOUGH TO
PREVENT MOISTURE FROM SPREADING NWD IN THE SLY FLOW ALOFT. WATER
VAPOR IMAGERY SHOWS A CONVERGENT BAND OF MOISTURE OVER NRN OREGON AND
SRN WA. COMPLICATING MATTERS IS COLD NLY FLOW DIVING INTO ERN WA. THE
END RESULT IS OFFSHORE LOW-LEVEL FLOW THROUGH THE COLUMBIA GORGE. A
SENSOR IN CORBETT REGISTERED WIND GUSTS TO NEAR 70 MPH BETWEEN 9 AND
10Z. TEMPERATURES IN THE UPPER HOOD RIVER VALLEY WERE RUNNING CLOSE
TO FREEZING JUST BEFORE 10Z.
THE 03Z RUN OF THE HRRR SHOWS THE MOISTURE BAND DRIFTING N OF THE
COLUMBIA RIVER BY 14Z. WILL NEED TO KEEP A MENTION OF MIXED PRECIP
NEAR K4S2 AND IN THE UPPER HOOD RIVER VALLEY THIS MORNING. NAM
SOUNDING FOR A POINT NEAR K4S2 SHOWS A FREEZING-RAIN PROFILE AT 17Z.
HOWEVER...IT APPEARS THE MODEL IS TOO COLD AT THE SURFACE COMPARED TO
CURRENT READINGS. ALL IN ALL...PRECIP IS EXPECTED TO DIMINISH ACROSS
THE NRN ZONES AS THE DAY PROGRESSES. NAM MAINTAINS ABOUT -8 TO -10 MB
KTTD-KDLS GRADIENT TODAY. LOCAL WIND STUDY SUGGESTS WIND GUSTS 65-75
MPH ARE LIKELY AT THE MOST WIND-PRONE AREAS AT THE WEST END OF THE
COLUMBIA GORGE WITH THAT GRADIENT MAGNITUDE. QUITE A CONTRAST IN HIGH
TEMPS TODAY AS WELL. K4S2 WILL BE LUCKY TO REACH 40 DEG WHILE THE SRN
INTERIOR VALLEYS WILL BE IN THE LOW 60S.
TONIGHT AND WED LOOK TO BE DRY AS THE H5 RIDGE STRENGTHENS A BIT IN
RESPONSE TO THE DEEPENING LOW PRES OUT NEAR 140W. THE AIR MASS WILL
BE RATHER MILD AND MOIST IN THE LOWER LEVELS...LEADING TO LOWLAND FOG
TONIGHT. THE OFFSHORE LOW-LEVEL FLOW STARTS TO WANE WED AS THE COLDER
AIR IS FORCED FURTHER EAST. THE NEXT BATCH OF PRECIP ENTERS SW OREGON
WED AFTERNOON AND REACHES THE SWRN ZONES LATE WED AFTERNOON OR WED
EVENING. MODELS DIFFER ON THE UPPER LOW PLACEMENT ...WITH THE ECMWF
FURTHER N...OFF THE SRN OREGON COAST...COMPARED TO THE GFS. MODELS
ARE DEPICTING SOME SORT OF DEFORMATION ZONE SETTING UP WED NIGHT THEN
DRIFTING N INTO SRN WA BY 18Z THU. BUMPED UP POPS WED NIGHT...
ESPECIALLY OVER THE SRN HALF OF THE AREA. MAY NEED TO INCREASE THEM
EVEN MORE SHOULD MODELS MAINTAIN THEIR CURRENT TRENDS. WEISHAAR
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
THURSDAY NIGHT THROUGH MONDAY...SPLIT FLOW WILL PREVAIL THROUGH THE
PERIOD. EXPECT NEAR NORMAL TEMPERATURES AND PRECIPITATION THROUGH
FRIDAY AS A WEAK UPPER LEVEL LOW PRESSURE SYSTEM MOVES INTO THE
REGION AND DISSIPATES THURSDAY NIGHT. A MORE ORGANIZED UPPER LOW
OFFSHORE WILL APPROACH THE AREA FRIDAY...HOWEVER IT LOOKS TO BE
PUSHED SOUTHWARD INTO SOUTHWESTERN OREGON/NORTHERN CALIFORNIA BY A
DEVELOPING UPPER TROUGH/SHORT WAVE THAT WILL DIVE SOUTH OUT OF
CANADA. THIS UPPER TROUGH WILL NEED TO BE MONITORED. AT THIS TIME
MODELS ARE IN FAIR AGREEMENT THAT THE UPPER TROUGH WILL BRING A SURGE
OF COLD AIR INTO THE CWA VIA THE COLUMBIA GORGE LATE FRIDAY INTO
SATURDAY. IN ADDITION...BOTH THE ECMWF AND TO A LESSER EXTENT THE GFS
DEVELOP A SURFACE LOW OFFSHORE FRIDAY NIGHT...FURTHER INDUCING COLD
OFFSHORE FLOW AND POTENTIALLY ENTRAINING MOISTURE FROM THE
AFOREMENTIONED UPPER LOW TO THE SOUTH AND ADVECTING IT NORTHWARD. ALL
IN ALL...THERE IS POTENTIAL FOR SNOW OR FREEZING RAIN SATURDAY
THROUGH MONDAY FROM PDX EAST INTO THE GORGE. HOWEVER... PLENTY OF
UNCERTAINTY REMAINS. FORECASTER CONFIDENCE IS VERY LOW AT THIS TIME
ABOUT WHETHER TEMPERATURES WILL IN FACT BE COLD ENOUGH... OR IF THE
COLD AIR AND MOISTURE WILL BE COINCIDENT. BB
&&
.AVIATION...MOSTLY VFR CONDITIONS EARLY THIS MORNING EXCEPT FOR
PATCHY MVFR TO IFR CIGS IN THE CENTRAL AND SOUTHERN WILLAMETTE
VALLEY AND ALONG THE COLUMBIA RIVER NEAR KKLS. THE IFR CONDITIONS
HAVE BEEN FAIRLY ISOLATED TO VCNTY OF KEUG SO FAR. EXPECT IFR
CONDITIONS TO CONTINUE THERE THROUGH THIS MORNING. DEW POINT
DEPRESSIONS SUGGEST THAT OTHER VALLEY LOCATIONS WILL SEE SOME FOG
AND HAVE TEMPORARY MVFR-IFR CONDITIONS THIS MORNING...ESPECIALLY
WHERE THERE IS CALM WINDS. HIGH CLOUDS STREAMING OVER SHOULD
MINIMIZE RADIATION COOLING AND DO NOT EXPECT THE FOG TO BE
WIDESPREAD.
EAST WINDS WILL DOMINATE TODAY AND TONIGHT WITH
NORTHERLY WINDS THROUGH THE CENTRAL WILLAMETTE VALLEY. THE WINDS
WILL BE GUSTY NEAR KTTD WITH GUSTS OF 40 KT LIKELY THIS AFTERNOON
AND EVENING. THE WINDS SHOULD KEEP MOST AREAS VFR EXCEPT FOR THE
MORE SHELTERED AREAS LIKE KEUG...KHIO AND KKLS WHERE THERE WILL BE
PERIODS OF REDUCED VSBYS DUE TO FOG THIS MORNING AND POSSIBLY
AGAIN LATE TONIGHT.
KPDX AND APPROACHES...VFR CONDITIONS EXPECTED TODAY. EAST WINDS AT
THE AIRPORT TODAY WITH POSSIBLE GUSTS UP TO 25 KT THIS AFTERNOON
AND EVENING. HARTLEY
&&
.MARINE UPDATE...EAST WINDS ARE STRONGER AROUND THE COLUMBIA RIVER
ENTRANCE AREA AS BUOY #29 HAS BEEN REPORTING WINDS OF 15 TO 20 KT
WITH GUSTS TO CLOSE TO 30 KT. ALTHOUGH THESE WINDS ARE PROBABLY NOT
WIDESPREAD...THINK THEY WILL BE ENOUGH FAR REACHING TO JUSTIFY A
SMALL CRAFT ADVISORY. THE STRONGEST WINDS WILL BE AROUND THE
ENTRANCE OF THE COLUMBIA RIVER AND NORTHWARD.
PREVIOUS MARINE DISCUSSION...HIGH PRESSURE INLAND COMBINED WITH LOW
PRESSURE OVER THE NE PACIFIC HAS RESULTED IN EAST TO SOUTHEAST WINDS
OVER THE WATERS. THE OFFSHORE WINDS ARE STRONGEST TO THE NORTH
ESPECIALLY NEAR THE ENTRANCE OF THE COLUMBIA RIVER. THE SURFACE
PRESSURE GRADIENT WILL CONTINUE TO STRENGTHEN TODAY AND AREAS NORTH
OF CANNON BEACH MAY HAVE AN OCCASIONAL GUST TO 25 KT. DO NOT THINK
THAT THESE GUSTS WILL BE WIDESPREAD OR FREQUENT ENOUGH TO WARRANT AN
ADVISORY..BUT WILL MONITOR THE WINDS CLOSELY IN CASE AN UPDATE IS
NECESSARY.
SEAS BECOME COMPLICATED TUESDAY THROUGH THURSDAY AS MULTIPLE LOWS
WEST AND SOUTHWEST OF THE WATERS WILL GENERATE A VARIETY OF SWELL
TRAINS THROUGH THE WATERS. THE SWELL HEIGHTS OF THE INDIVIDUAL
TRAINS ARE GENERALLY LESS THAN 5 FEET. OVERALL WAVE HEIGHTS WILL
GENERALLY BE BETWEEN 6 AND 9 FEET TONIGHT THROUGH THURSDAY
COMPILED BY A LONG PERIOD SW SWELL AND A SHORTER PERIOD W SWELL.
THE SEAS IN THE SOUTHERN WATERS MAY BE SLIGHTLY STRONGER AND AN
ADVISORY FOR SEAS MAY BE NECESSARY FOR AREAS SOUTH OF CASCADE HEAD
WEDNESDAY AND WEDNESDAY NIGHT. HARTLEY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM THIS EVENING FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
208 AM PST TUE FEB 25 2014
.SYNOPSIS...HIGH PRESSURE ALOFT CENTERED OVER THE PACIFIC NORTHWEST
WILL STRENGTHEN TODAY AS A DEEP LOW PRESSURE SYSTEM REMAINS WELL
OFFSHORE AND MUCH COLDER NORTH FLOW ALOFT RESIDES OVER THE NORTHERN
ROCKIES. OFFSHORE LOW-LEVEL FLOW THROUGH THE COLUMBIA GORGE WIL
CONTINUE THROUGH TONIGHT...THEN GRADUALLY WEAKEN WEDNESDAY. RESIDUAL
COLD AIR NEAR HOOD RIVER AND IN THE UPPER HOOD RIVER VALLEY TODAY
WILL MAINTAIN THREAT OF MIXED PRECIPITATION THIS MORNING. THE RIDGE
SHIFTS TO THE EAST WEDNESDAY AS AN UPPER LOW SWINGS TOWARD SOUTHWEST
OREGON. RAIN SPREADS INTO THE SOUTH ZONES WEDNESDAY EVENING THEN
EXPANDS NORTH WEDNESDAY NIGHT. A LOW PRESSURE AREA REMAINS PARKED OFF
THE NRN CALIFORNIA COAST THURSDAY AND FRIDAY WITH THE BEST THREAT OF
PRECIPITATION OVER THE SOUTH. UNSETTLED AND POSSIBLY QUITE COOL
WEATHER WILL RETURN FOR THE COMING WEEKEND.
&&
.SHORT TERM...TUESDAY THROUGH THURSDAY...A RATHER COMPLEX LARGE-SCALE
PATTERN CONTINUES OVER THE PAC NW TODAY. THE MAIN FEATURES OF NOTE
EARLY THIS MORNING INCLUDE AN ELONGATED FRONTAL ZONE ASSOCIATED WITH
A LOW OUT NEAR 44N 145W AND A 500 MB RIDGE AXIS CENTERED OVER WRN
WASHINGTON AND OREGON. HOWEVER...THE RIDGE IS NOT STRONG ENOUGH TO
PREVENT MOISTURE FROM SPREADING NWD IN THE SLY FLOW ALOFT. WATER
VAPOR IMAGERY SHOWS A CONVERGENT BAND OF MOISTURE OVER NRN OREGON AND
SRN WA. COMPLICATING MATTERS IS COLD NLY FLOW DIVING INTO ERN WA. THE
END RESULT IS OFFSHORE LOW-LEVEL FLOW THROUGH THE COLUMBIA GORGE. A
SENSOR IN CORBETT REGISTERED WIND GUSTS TO NEAR 70 MPH BETWEEN 9 AND
10Z. TEMPERATURES IN THE UPPER HOOD RIVER VALLEY WERE RUNNING CLOSE
TO FREEZING JUST BEFORE 10Z.
THE 03Z RUN OF THE HRRR SHOWS THE MOISTURE BAND DRIFTING N OF THE
COLUMBIA RIVER BY 14Z. WILL NEED TO KEEP A MENTION OF MIXED PRECIP
NEAR K4S2 AND IN THE UPPER HOOD RIVER VALLEY THIS MORNING. NAM
SOUNDING FOR A POINT NEAR K4S2 SHOWS A FREEZING-RAIN PROFILE AT 17Z.
HOWEVER...IT APPEARS THE MODEL IS TOO COLD AT THE SURFACE COMPARED TO
CURRENT READINGS. ALL IN ALL...PRECIP IS EXPECTED TO DIMINISH ACROSS
THE NRN ZONES AS THE DAY PROGRESSES. NAM MAINTAINS ABOUT -8 TO -10 MB
KTTD-KDLS GRADIENT TODAY. LOCAL WIND STUDY SUGGESTS WIND GUSTS 65-75
MPH ARE LIKELY AT THE MOST WIND-PRONE AREAS AT THE WEST END OF THE
COLUMBIA GORGE WITH THAT GRADIENT MAGNITUDE. QUITE A CONTRAST IN HIGH
TEMPS TODAY AS WELL. K4S2 WILL BE LUCKY TO REACH 40 DEG WHILE THE SRN
INTERIOR VALLEYS WILL BE IN THE LOW 60S.
TONIGHT AND WED LOOK TO BE DRY AS THE H5 RIDGE STRENGTHENS A BIT IN
RESPONSE TO THE DEEPENING LOW PRES OUT NEAR 140W. THE AIR MASS WILL
BE RATHER MILD AND MOIST IN THE LOWER LEVELS...LEADING TO LOWLAND FOG
TONIGHT. THE OFFSHORE LOW-LEVEL FLOW STARTS TO WANE WED AS THE COLDER
AIR IS FORCED FURTHER EAST. THE NEXT BATCH OF PRECIP ENTERS SW OREGON
WED AFTERNOON AND REACHES THE SWRN ZONES LATE WED AFTERNOON OR WED
EVENING. MODELS DIFFER ON THE UPPER LOW PLACEMENT ...WITH THE ECMWF
FURTHER N...OFF THE SRN OREGON COAST...COMPARED TO THE GFS. MODELS
ARE DEPICTING SOME SORT OF DEFORMATION ZONE SETTING UP WED NIGHT THEN
DRIFTING N INTO SRN WA BY 18Z THU. BUMPED UP POPS WED NIGHT...
ESPECIALLY OVER THE SRN HALF OF THE AREA. MAY NEED TO INCREASE THEM
EVEN MORE SHOULD MODELS MAINTAIN THEIR CURRENT TRENDS. WEISHAAR
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
THURSDAY NIGHT THROUGH MONDAY...SPLIT FLOW WILL PREVAIL THROUGH THE
PERIOD. EXPECT NEAR NORMAL TEMPERATURES AND PRECIPITATION THROUGH
FRIDAY AS A WEAK UPPER LEVEL LOW PRESSURE SYSTEM MOVES INTO THE
REGION AND DISSIPATES THURSDAY NIGHT. A MORE ORGANIZED UPPER LOW
OFFSHORE WILL APPROACH THE AREA FRIDAY...HOWEVER IT LOOKS TO BE
PUSHED SOUTHWARD INTO SOUTHWESTERN OREGON/NORTHERN CALIFORNIA BY A
DEVELOPING UPPER TROUGH/SHORT WAVE THAT WILL DIVE SOUTH OUT OF
CANADA. THIS UPPER TROUGH WILL NEED TO BE MONITORED. AT THIS TIME
MODELS ARE IN FAIR AGREEMENT THAT THE UPPER TROUGH WILL BRING A SURGE
OF COLD AIR INTO THE CWA VIA THE COLUMBIA GORGE LATE FRIDAY INTO
SATURDAY. IN ADDITION...BOTH THE ECMWF AND TO A LESSER EXTENT THE GFS
DEVELOP A SURFACE LOW OFFSHORE FRIDAY NIGHT...FURTHER INDUCING COLD
OFFSHORE FLOW AND POTENTIALLY ENTRAINING MOISTURE FROM THE
AFOREMENTIONED UPPER LOW TO THE SOUTH AND ADVECTING IT NORTHWARD. ALL
IN ALL...THERE IS POTENTIAL FOR SNOW OR FREEZING RAIN SATURDAY
THROUGH MONDAY FROM PDX EAST INTO THE GORGE. HOWEVER... PLENTY OF
UNCERTAINTY REMAINS. FORECASTER CONFIDENCE IS VERY LOW AT THIS TIME
ABOUT WHETHER TEMPERATURES WILL IN FACT BE COLD ENOUGH... OR IF THE
COLD AIR AND MOISTURE WILL BE COINCIDENT. BB
&&
.AVIATION...MOSTLY VFR CONDITIONS EARLY THIS MORNING EXCEPT FOR
PATCHY MVFR TO IFR CIGS IN THE CENTRAL AND SOUTHERN WILLAMETTE
VALLEY AND ALONG THE COLUMBIA RIVER NEAR KKLS. THE IFR CONDITIONS
HAVE BEEN FAIRLY ISOLATED TO VCNTY OF KEUG SO FAR. EXPECT IFR
CONDITIONS TO CONTINUE THERE THROUGH THIS MORNING. DEW POINT
DEPRESSIONS SUGGEST THAT OTHER VALLEY LOCATIONS WILL SEE SOME FOG
AND HAVE TEMPORARY MVFR-IFR CONDITIONS THIS MORNING...ESPECIALLY
WHERE THERE IS CALM WINDS. HIGH CLOUDS STREAMING OVER SHOULD
MINIMIZE RADIATION COOLING AND DO NOT EXPECT THE FOG TO BE
WIDESPREAD.
EAST WINDS WILL DOMINATE TODAY AND TONIGHT WITH
NORTHERLY WINDS THROUGH THE CENTRAL WILLAMETTE VALLEY. THE WINDS
WILL BE GUSTY NEAR KTTD WITH GUSTS OF 40 KT LIKELY THIS AFTERNOON
AND EVENING. THE WINDS SHOULD KEEP MOST AREAS VFR EXCEPT FOR THE
MORE SHELTERED AREAS LIKE KEUG...KHIO AND KKLS WHERE THERE WILL BE
PERIODS OF REDUCED VSBYS DUE TO FOG THIS MORNING AND POSSIBLY
AGAIN LATE TONIGHT.
KPDX AND APPROACHES...VFR CONDITIONS EXPECTED TODAY. EAST WINDS AT
THE AIRPORT TODAY WITH POSSIBLE GUSTS UP TO 25 KT THIS AFTERNOON
AND EVENING. HARTLEY
&&
.MARINE...HIGH PRESSURE INLAND COMBINED WITH LOW PRESSURE OVER THE NE
PACIFIC HAS RESULTED IN EAST TO SOUTHEAST WINDS OVER THE WATERS.
THE OFFSHORE WINDS ARE STRONGEST TO THE NORTH ESPECIALLY NEAR THE
ENTRANCE OF THE COLUMBIA RIVER. THE SURFACE PRESSURE GRADIENT WILL
CONTINUE TO STRENGTHEN TODAY AND AREAS NORTH OF CANNON BEACH MAY
HAVE AN OCCASIONAL GUST TO 25 KT. DO NOT THINK THAT THESE GUSTS
WILL BE WIDESPREAD OR FREQUENT ENOUGH TO WARRANT AN ADVISORY..BUT
WILL MONITOR THE WINDS CLOSELY IN CASE AN UPDATE IS NECESSARY.
SEAS BECOME COMPLICATED TUESDAY THROUGH THURSDAY AS MULTIPLE LOWS
WEST AND SOUTHWEST OF THE WATERS WILL GENERATE A VARIETY OF SWELL
TRAINS THROUGH THE WATERS. THE SWELL HEIGHTS OF THE INDIVIDUAL
TRAINS ARE GENERALLY LESS THAN 5 FEET. OVERALL WAVE HEIGHTS WILL
GENERALLY BE BETWEEN 6 AND 9 FEET TONIGHT THROUGH THURSDAY
COMPILED BY A LONG PERIOD SW SWELL AND A SHORTER PERIOD W SWELL.
THE SEAS IN THE SOUTHERN WATERS MAY BE SLIGHTLY STRONGER AND AN
ADVISORY FOR SEAS MAY BE NECESSARY FOR AREAS SOUTH OF CASCADE HEAD
WEDNESDAY AND WEDNESDAY NIGHT. HARTLEY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
557 AM CST TUE FEB 25 2014
.DISCUSSION...
SEE 12Z AVIATION DISCUSSION.
&&
.AVIATION...
A WEAK BOUNDARY EXTENDS EAST TO WEST ACROSS TEXAS TO A WEAK AREA
OF LOW PRESSURE OVER SOUTHWEST TEXAS. WATER VAPOR IMAGERY SHOWS A
DISTURBANCE APPROACHING SOUTHEAST TEXAS SO FEEL LIFT WILL INCREASE
AND COUPLED WITH ABUNDANT LOW LEVEL MOISTURE SHOULD ALLOW FOR AT
LEAST SCT SHRA TODAY. LEANED A BIT TOWARD THE HRRR BUT IT LOOKS A
BIT OVERDONE. LIFR/IFR CONDS TO PREVAIL FOR MUCH OF THE MORNING
WITH SOME IMPROVEMENT IN THE AFTN. A COLD FRONT WILL CROSS THE
AREA TONIGHT. ADDED TSRA FOR LATE AFTN/TONIGHT AS INSTABILITY
INCREASES. MODELS ALL ON THE SAME PAGE FOR A STEADY WIDESPREAD
RAIN ON WED MORNING AS ANOTHER DISTURBANCE INTERACTS WITH THE 850
MB BOUNDARY. 43
&&
.PREV DISCUSSION... /ISSUED 456 AM CST TUE FEB 25 2014/
DISCUSSION...
FOG HAS FORMED THIS MORNING ACROSS THE AREA WITH IT BEING MOST
DENSE ACROSS THE SOUTHERN HALF OF THE CWA. A WARM FRONT REMAINS
JUST SOUTH OF THE DALLAS- FORT WORTH AREA NEAR CORSICANA THIS
MORNING. AT 500MB A SHORTWAVE WAS ANALYZED AND IS FORECASTED TO
PUSH OFF TOWARDS THE SOUTHEAST TODAY WITH A SECONDARY SHORTWAVE
EXPECTED TO DROP DOWN THIS AFTERNOON INTO MONTANA. THIS SECONDARY
SHORTWAVE WILL DROP FAR ENOUGH SOUTH TO PUSH A FRONT THROUGH THE
AREA AROUND MIDNIGHT WEDNESDAY MORNING. WITH THE FRONTAL PASSAGE
WILL COME THE CHANCE OF RAIN. EARLY MORNING AMDAR SOUNDINGS SHOWS
A BREAKABLE CAP IN PLACE AT 800MB WITH THE SOUNDING SATURATED
BELOW 800MB. PWAT VALUES ARE ALREADY AROUND 1.3" ACCORDING TO THE
GPS MET SITE AND ARE FORECASTED TO RISE TO AROUND 1.60" AS
SUPPORTED BY THE NAM AND GFS. DURING THE AFTERNOON TODAY POCKETS
OF PVA WILL BE MOVING ACROSS THE AREA WHICH SHOULD HELP TO PROVIDE
SOME LIFT. WIDESPREAD LIFT WILL DEVELOP AS THE FRONT APPROACHES
AND WITH INSTABILITY AND MOISTURE IN PLACE RAIN LOOKS LIKELY LATE
TUESDAY NIGHT INTO WEDNESDAY MORNING. THE ONLY THING LACKING
INITIALLY TUESDAY AFTERNOON IS SUPPORT FROM THE UPPER LEVEL JET.
TUESDAY AFTERNOON THE UPPER LEVEL JET WILL TAKE ON AN ANTICYCLONIC
CURVATURE. WITH SOUTHEAST TEXAS BEING ON THE RIGHT SIDE OF THE JET
THIS WOULD FAVOR UPPER LEVEL CONVERGENCE.
THE BEST CHANCE OF RAIN LOOKS TO COME WEDNESDAY MORNING AS A
PLETHORA OF ITEMS START TO COME INTO PHASE. THE SHORTWAVE
MENTIONED ABOVE WILL INITIALLY DIVE TO THE SOUTH BEFORE HEADING
OFF TO THE EAST ALLOWING THE 850MB FRONT TO SLOW DOWN AND/ OR
STALL OVER SOUTHEAST TEXAS. THE SUBTROPICAL JET WILL ALSO LOOSE
ITS ANTICYCLONIC CURVATURE AND BEGIN TO STRENGTHEN AND MOVE OFF TO
THE EAST. THIS WOULD PUT SOUTHEAST TEXAS IN A RRQ OR DIVERGENT
REGION. PWAT VALUES ALSO REMAIN AROUND THE 1.50" MARK. AVERAGE PWAT
VALUES FOR THIS TIME OF YEAR IS ABOUT 1.15" FOR SOUTHEAST TEXAS.
TWO STANDARD DEVIATIONS ABOVE NORMAL IS AROUND 1.60". MOST OF THE
RAINFALL WILL LIKELY OCCUR WHERE THE 850MB FRONT STALLS. THE ECMWF
STALLS THE 850 FRONT IN OUR NORTHERN ZONES WEDNESDAY MORNING
BEFORE WASHING IT OUT. THE NAM AND GFS FOLLOW CLOSELY WITH THE
ECMWF.
THURSDAY MORNING LOOKS TO BE COLD AS SURFACE HIGH PRESSURE SETTLES
OVERHEAD. AS OF NOW LOOKS THAT CLOUDS WILL HANG AROUND WHICH
SHOULD HELP KEEP TEMPERATURES UP A BIT. THURSDAY AFTERNOON SURFACE
HIGH PRESSURE WILL BEGIN TO QUICKLY PULL OFF TO THE EAST AS THE
NEXT UPPER LEVEL DISTURBANCE APPROACHES THE SOUTHERN CALIFORNIA
COAST. THE GFS HOLDS UP THE DISTURBANCE WHILE THE ECMWF KEEPS A
MORE PROGRESSIVE PATTERN. THE MORE PROGRESSIVE EURO ALSO PUSHES A
FRONT THROUGH MONDAY MORNING WHILE THE GFS HOLDS THE FRONT OFF TO
LATE MONDAY EARLY TUESDAY MORNING. FOR NOW HAVE LEANED TOWARDS THE
ECMWF WHICH HAS PERFORMED WELL THIS WINTER. 23
MARINE...
WARM MOIST FLOWING OVER RELATIVELY COOL SHELF WATERS WILL MAINTAIN
PERIODS OF SEA FOG TODAY INTO THIS EVENING. PLATFORMS OFFSHORE
CONTINUE TO REPORT DENSE FOG SO WILL MAINTAIN THE DENSE FOG ADVISORY
FOR ALL WATERS THROUGH 18Z. A COLD FRONT WILL CROSS THE COASTAL
WATERS EARLY WEDNESDAY MORNING. AN ABRUPT WIND SHIFT SHOULD END THE
SEA FOG. WINDS WILL QUICKLY INCREASE AND A SMALL CRAFT ADVISORY WILL
LIKELY BE REQUIRED FOR WEDNESDAY. THE GRADIENT IS EXPECTED TO WEAKEN
WED NIGHT INTO THURSDAY. ONSHORE WINDS RETURN ON THURSDAY AND
WILL PERSIST THROUGH THE WEEKEND. WIND SPEEDS WILL GRADUALLY
INCREASE TOWARD THE END OF THE WEEK WITH MODERATE TO STRONG
ONSHORE WINDS EXPECTED NEXT WEEKEND. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 69 43 45 34 58 / 70 70 60 30 10
HOUSTON (IAH) 70 47 49 37 59 / 70 70 70 30 10
GALVESTON (GLS) 69 53 54 42 57 / 60 70 70 40 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: BRAZORIA...CHAMBERS...FORT BEND...
GALVESTON...HARRIS...JACKSON...LIBERTY...MATAGORDA...
WHARTON.
GM...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
230 PM MST TUE FEB 25 2014
.SYNOPSIS...
DRY WESTERLY FLOW IS EXPECTED TO CONTINUE INTO EARLY FRIDAY ACROSS
THE REGION...KEEPING TEMPERATURES ABOVE NORMAL...RISING INTO THE
UPPER 70S TO LOWER 80S EACH DAY ACROSS THE LOWER DESERTS...WITH
PERIODS OF HIGH CLOUDS PASSING OVERHEAD FROM TIME TO TIME. A
DRAMATIC CHANGE IN THE WEATHER IS THEN EXPECTED FROM LATE FRIDAY
INTO THE UPCOMING WEEKEND AS A STRONG...AND WET PACIFIC STORM MOVES
INTO THE DESERT SOUTHWEST. THIS STORM IS EXPECTED TO BRING
WIDESPREAD SIGNIFICANT RAINFALL...AND MUCH COOLER TEMPERATURES TO
THE REGION.
&&
.DISCUSSION...
SUBTROPICAL MOISTURE IN THE FORM OF MID AND HIGH CLOUDS CONTINUES TO
STREAM NORTHEASTWARD ACROSS SOUTHERN AZ AHEAD OF A WEAK VORT MAX
NORTH OF PUERTO PENASCO. LATEST RADAR IMAGERY SHOWS SOME WEAK ECHOES
ACROSS SE AZ AND HI-RES WRF GUIDANCE ALONG WITH THE HRRR SUGGEST
SPRINKLES MAY CLIP PORTIONS OF EASTERN MARICOPA...PINAL AND SOUTHERN
GILA COUNTIES THROUGH LATE THIS AFTERNOON. SOMEWHAT OF A CLEARING
TREND FROM WEST TO EAST IS ANTICIPATED OVERNIGHT...THOUGH AREAS OF
CIRRUS WILL STILL BE PREVALENT.
WEDNESDAY...SHORT-WAVE RIDGE BECOMES REESTABLISHED ACROSS THE DESERT
SOUTHWEST. LATEST MODEL CONSENSUS INDICATES THAT THICKER HIGH CLOUDS
ASSOCIATED WITH THE NEXT PACIFIC TROUGH WILL SLIDE THROUGH MAINLY
NORTHERN AZ IN THE AFTERNOON. THE INCREASED INSOLATION SHOULD YIELD
HIGH TEMPERATURES A FEW DEGREES WARMER THAN THOSE OBSERVED TUESDAY
AND STILL ABOVE NORMAL.
&&
.PREVIOUS DISCUSSION...
THURSDAY...
MODELS CONTINUE TO BRING A WEAK SHORTWAVE EASTWARD INTO THE GREAT
BASIN/4-CORNERS REGION DURING THE DAY ON THURSDAY. ALTHOUGH THE
LATEST MODEL RUNS STILL KEEP MOST OF THE MOISTURE AND DYNAMICS WELL
TO OUR NORTH...THE LATEST GEM AND EURO MODEL SUITES NOW ARE
FORECASTING A SLIGHT CHANCE FOR SPRINKLES...OR LIGHT SHOWERS OVER
THE HIGHEST ELEVATIONS OF SOUTHERN GILA COUNTY...AS THE CLOUD BASES
LOWER TO AROUND...OR JUST BELOW 10K FEET BRIEFLY ON THURSDAY.
THUS...HAVE INCREASED POPS OVER THAT REGION INTO THE SLIGHT CHANCE
RANGE TO REFLECT THESE CHANGES. HOWEVER...IT STILL APPEARS THAT THE
MAIN IMPACTS FROM THIS SYSTEM WILL BE ONLY TO BRING GUSTY WINDS TO
SOUTHEAST CA WEDNESDAY AFTERNOON AND EVENING...AND TO INCREASE
CLOUDINESS OVER THE REGION.
FRIDAY AND SATURDAY...
IT NOW APPEARS THAT IT IS ALMOST CERTAIN THAT WE WILL SEE A MAJOR
CHANGE IN THE WEATHER FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.
IN FACT...ALL OF THE LATEST MODEL RUNS ARE EVEN MORE BULLISH WITH
THIS SYSTEM THEN THEY WERE ON PREVIOUS RUNS. THERE IS NOW EXCELLENT
AGREEMENT BETWEEN THE EURO...GFS...AND GEM THAT THIS SYSTEM...WHICH
IS NOW TRACKING EASTWARD ACROSS THE CENTRAL PACIFIC SOUTH OF THE
ALEUTIAN CHAIN...WILL NOW PICK UP COPIOUS AMOUNTS OF MOISTURE AS IT
INTERACTS WITH A VERY STRONG (180KT) PACIFIC JET THAT EXTENDS ALL
THE WAY EASTWARD FROM SOUTHERN JAPAN (130E) TO NORTHEAST OF HAWAII
(ABOUT 150W). ALL THREE MODELS NOW PUSH THE SYSTEM INLAND
EARLIER...INTO SOUTHERN CA BY FRIDAY MORNING...THEN SLOWLY ACROSS
OUR CWA FROM LATE FRIDAY INTO EARLY SUNDAY. LATEST GFS PWAT
FORECASTS NOW PUSH A PLUME OF 1 INCH OR GREATER PWATS INTO...AND
ACROSS OUR CWA LATE FRIDAY AND SATURDAY. BOTH THE GFS AND EURO
FORECAST SOUNDINGS FOR KPHX ARE NOW SHOWING A VERY DEEP NEARLY
SATURATED MOISTURE LAYER...ALL THE WAY FROM THE SFC TO 35K FEET
MOVING IN ON SATURDAY...WITH STRONG SW-LY WINDS THROUGH THE ENTIRE
COLUMN...SOMETHING WE DON/T SEE VERY OFTEN AROUND HERE.
ALL THREE MODELS HAVE ALSO GREATLY INCREASED THEIR QPF FORECASTS.
THEY NOW ARE FORECASTING STORM TOTAL RAINFALL AMOUNTS OF 0.25-0.50
OF AN INCH FOR THE LOWER ELEVATIONS OF SE CA AND SW AZ...0.75-1.25
INCH FOR JOSHUA TREE NB AND ACROSS THE LOWER ELEVATIONS OF
SOUTH-CENTRAL ARIZONA...AND 1 TO 2 INCHES ACROSS THE HIGHER TERRAIN
OF SOUTH-CENTRAL ARIZONA. ALTHOUGH WIDESPREAD HYDRO ISSUES ARE VERY
UNLIKELY...DUE TO THE VERY DRY ANTECEDENT CONDITIONS...THERE WOULD
BE LIKELY SOME SMALL STREAM AND URBAN FLOODING ISSUES IF THESE
RAINFALL AMOUNTS DUE VERIFY.
BASED ON THESE UPDATED FORECAST...I HAVE GREATLY INCREASED POPS
ACROSS OUR WESTERN ZONES LATE FRIDAY AND PUSHED POPS INTO THE LIKELY
TO CATEGORICAL RANGE FOR MUCH OF OUR CWA ON SATURDAY. IN
ADDITION...I HAVE LOWERED HIGH TEMPS FURTHER ACROSS SOUTH-CENTRAL
ARIZONA ON SATURDAY...INTO THE LOW TO MID 60S AS THE LIKELY STEADY
RAIN AND THICK CLOUD COVER SHOULD KEEP TEMPS WELL BELOW NORMAL...A
RATHER RAW AND WET DAY FOR A VERY BUSY SLATE OF OUTDOOR ACTIVITIES
THAT ARE PLANNED ACROSS THE GREATER PHX AREA. ON THE OTHER
HAND...SNOWFALL CONCERNS ACROSS OUR CWA APPEAR TO BE A
NON-ISSUE...AS THE SUBTROPICAL ORIGIN OF THE AIRMASS IS EXPECTED TO
KEEP SNOW LEVELS MAINLY AOA 7000FT. AHEAD OF THE SYSTEM...WE ALSO
NOW EXPECT STRONG SOUTH TO SOUTHWESTERLY WINDS ON FRIDAY AFTERNOON
ACROSS SOUTHEAST CA AND THE LOWER CO RIVER VALLEY...WITH WIND SPEEDS
APPROACHING ADVISORY CRITERIA AT SOME LOCATIONS.
SUNDAY THROUGH TUESDAY...
SOME LINGERING SHOWERS ARE LIKELY ON SUNDAY...AND MAYBE EVEN INTO
MONDAY ACROSS SOUTH-CENTRAL ARIZONA AS GENERAL TROUGHINESS HANGS
BACK OVER OUR REGION...BUT FURTHER SIGNIFICANT RAINFALL IS NOW
EXPECTED AT THIS TIME. NEXT TUESDAY SHOULD SEE WARMER...AND DRIER
CONDITIONS AS RIDGING ATTEMPTS TO REBUILD BACK OVER THE DESERT
SOUTHWEST.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
CONTINUED HIGH PRESSURE ALOFT TODAY INTO WEDNESDAY...HOWEVER IT WILL
BE A DIRTY RIDGE ALLOWING CONSIDERABLE MID/HI CLOUDS TO OVERSPREAD
THE TERMINALS. EXPECT SCT-BKN MID AND HI LEVEL DECKS FROM 12K FEET
ON UP NEXT 24 HOURS...WITH THE DEEPEST MOISTURE ACROSS THE CENTRAL
AZ DESERT TAF SITES. WINDS TO REMAIN QUITE LIGHT AND VARIABLE WITH
WEAK DIURNAL SIGNALS AT KIWA AND KPHX TODAY AND TONIGHT. NO AVIATION
CONCERNS NEXT 24 HOURS AT ANY AIRFIELD.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
A FAST MOVING DISTURBANCE PASSING BY TO THE NORTH WILL LEAD TO
AFTERNOON BREEZY CONDITIONS THURSDAY...AND CAUSE HUMIDITIES TO
BECOME ELEVATED WITH MOST DESERTS CLIMBING ABOVE 20 PERCENT.
OTHERWISE HIGH TEMPERATURES WILL STAY ABOVE SEASONAL NORMALS. HIGH
PRESSURE ALOFT WILL BRIEFLY RETURN FRIDAY FOR CONTINUED ABOVE NORMAL
HIGH TEMPERATURES...HOWEVER MOISTURE WILL INCREASE FROM THE WEST
AHEAD OF AN APPROACHING WET PACIFIC LOW PRESSURE SYSTEM...AND A
CHANCE OF SHOWERS WILL DEVELOP ACROSS THE WESTERN DESERTS DURING THE
AFTERNOON HOURS. BREEZY TO WINDY CONDITIONS WILL ALSO DEVELOP BY
AFTERNOON...ESPECIALLY FROM THE COLORADO RIVER VALLEY WESTWARD. MUCH
COOLER AND VERY MOIST AND UNSETTLED CONDITIONS ARE EXPECTED THIS
WEEKEND AS THE AFOREMENTIONED PACIFIC LOW MOVES EASTWARD AND ACROSS
THE AREA...BRINGING PERIODS OF RAIN OR RAIN SHOWERS TO BOTH THE
DESERTS AND HIGHER TERRAIN...BEGINNING FRIDAY NIGHT AND CONTINUING
ALL THE WAY INTO SUNDAY. BREEZY CONDITIONS WILL ACCOMPANY THIS
PASSING SYSTEM BOTH SATURDAY AND SUNDAY. ON MONDAY...A SOMEWHAT
DRIER NORTHWEST FLOW ALOFT WILL BUILD INTO THE AREA BEHIND THE
EXITING LOW PRESSURE SYSTEM...LEADING TO LESS WIND AND SLIGHT
WARMING WHICH WILL BRING HIGH TEMPERATURES BACK TOWARDS SEASONAL
NORMALS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...PERCHA
AVIATION...CB
FIRE WEATHER...CB
AREA FORECAST DISCUSSION
NWS TUCSON AZ
215 PM MST TUE FEB 25 2014
.SYNOPSIS...VARIABLE CLOUDS WITH A FEW SPRINKLES OR LIGHT SHOWERS
POSSIBLE INTO WEDNESDAY. A FEW MOUNTAIN SHOWERS POSSIBLE THURSDAY AS
A SYSTEM BRUSHES BY TO OUR NORTH. THEN...A STRONGER...WETTER AND
COOLER PACIFIC STORM SYSTEM WILL BRING GUSTY WINDS FRIDAY AND
SATURDAY WITH VALLEY RAIN AND MOUNTAIN SNOW OVER THE WEEKEND...ALONG
WITH MUCH COOLER TEMPERATURES.
&&
.DISCUSSION...INCREASING MID AND UPPER LEVEL MOISTURE IN SOUTHERLY
TO SOUTHWESTERLY FLOW HAS BROUGHT VIRGA AND SPRINKLES TO THE AREA
EARLY THIS AFTERNOON. SOUTHERLY TO SOUTHWESTERLY FLOW HAS PUSHED THE
PRECIPITABLE WATER UP TO AROUND .6 WITH .8 VALUES CREEPING INTO
NORTHERN SONORA. HRRR CONTINUES TO FOCUS BEST CHANCE OF MEASURABLE
PRECIP ACROSS SOUTHERN AREAS. VERY LIGHT QPF VALUES BUT SPRINKLES TO
LIGHT SHOWERS WILL BECOME MORE COMMON LATER THIS AFTERNOON AND
EVENING.
PARTIAL CLEARING FROM THE WEST IN THE EARLY MORNING HOURS...BUT WE
COULD STILL SEE A FEW SPRINKLES WEDNESDAY AS SOME MID LEVEL MOISTURE
REMAINS IN PLACE.
LATEST MODEL SUITES...ENSEMBLE MEANS AND MEASURE OF PREDICTABILITY
GREATLY INCREASING FOR THE WEEKEND SYSTEM. WE`LL START OUT WITH
GUSTY WINDS AND POTENTIAL BLOWING DUST ISSUES FRIDAY AFTERNOON AHEAD
OF THE SYSTEM.
SOME TIMING ISSUES BUT DECENT DYNAMICS AND ROBUST MOISTURE FIELDS
FROM A STRONG AND COOL PACIFIC STORM IS EXPECTED TO BRING OUR BEST
CHANCE OF SIGNIFICANT RAINFALL SINCE MID DECEMBER. ACTUALLY THIS
STORM LOOKS WETTER THAN THE DECEMBER STORMS...PERHAPS AS HEAVY AS
THE WET NOVEMBER SYSTEMS. STRONG UPSLOPE SHOULD INITIATE LIGHTER
SHOWER ACTIVITY EARLY SATURDAY. INITIAL IMPULSE LIFTS THROUGH
SATURDAY AFTERNOON FOLLOWED QUICKLY BY REINFORCING ENERGY SATURDAY
NIGHT. THE TRAJECTORY OF THIS REINFORCING ENERGY IS CURRENTLY
EXPECTED TO BULLSEYE SOUTHEAST ARIZONA SATURDAY NIGHT INTO SUNDAY
MORNING. IT`S EARLY BUT WE`LL LIKELY END UP WITH SOME WINTER
HEADLINES IN THE MOUNTAINS FOR EXCESSIVE SNOWFALL. SNOW LEVELS
FALLING TOWARD THE 6500 FT LEVEL SATURDAY NIGHT. EARLIEST ESTIMATES
OF QPF VALUES IN EXCESS OF 1/2 INCH IN VALLEYS WITH POTENTIAL OVER
AN INCH IN SOME LOCATIONS. HIGH CONFIDENCE FOR POP FORECAST WITH 70
IN VALLEYS AND 100 IN MOUNTAINS...BUT STILL MEDIUM CONFIDENCE FOR
HEAVY QPF VALUES.
&&
.AVIATION...FORECAST PERIOD THROUGH 27/00Z.
BKN-OVC CLOUDS AOA 10K FT AGL WILL CONTINUE ACROSS SE AZ THROUGH
26/09Z WITH PARTIAL CLEARING WED MORNING. SCT 6-8K FT ABOVE VALLEY
FLOORS AND OBSCURED MT TOPS IN ISOLD -SHRA ARE MOST LIKELY BTWN
26/00Z AND 26/06Z. SURFACE WIND GENERALLY LESS THAN 10 KTS THRU
26/21Z ALTHOUGH GUSTS 15-20 KTS PSBL NEAR -SHRA. WESTERLY WINDS
10-15KT WED AFT 26/21Z. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...SEVERAL DISTURBANCES WILL MOVE ACROSS THE REGION
OVER THE NEXT WEEK. THE FIRST TWO MAY BRING LIGHT SHOWERS THIS
EVENING INTO THURSDAY. ASSOCIATED PERIODS OF CLOUD COVER WILL KEEP
DAYTIME TEMPERATURES COOLER THAN OF LATE...ALTHOUGH THEY WILL REMAIN
ABOVE NORMAL. NIGHTTIME TEMPERATURES WILL ALSO BE ABOVE NORMAL THE
NEXT FEW NIGHTS.
WIDESPREAD SIGNIFICANT PRECIPITATION IS NOT EXPECTED UNTIL A
STRONGER PACIFIC STORM SYSTEM APPROACHES SOUTHERN ARIZONA LATE THIS
WEEK WITH THE BEST CHANCE FOR PRECIPITATION LOOKING LIKE SATURDAY.
BREEZY TO WINDY CONDITIONS ARE FORECAST IN ADVANCE OF THIS SYSTEM
FROM THURSDAY THROUGH SATURDAY AND COOLER TEMPERATURES WILL
ACCOMPANY THE PRECIPITATION THIS WEEKEND.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
MEYER/DROZD
AREA FORECAST DISCUSSION
NWS TUCSON AZ
925 AM MST TUE FEB 25 2014
.SYNOPSIS...A PLUME OF TROPICAL MOISTURE WILL BRING AREAS OF LIGHT
SHOWERS OR SPRINKLES TO PARTS OF SOUTHEAST ARIZONA INTO WEDNESDAY.
IT WILL ALSO BE COOLER TODAY...ESPECIALLY FOR ANY AREAS THAT SEE THE
LIGHT PRECIPITATION. A FEW MOUNTAIN SHOWERS POSSIBLE THURSDAY AS A
SYSTEM BRUSHES BY TO OUR NORTH. THEN...A STRONGER AND COOLER PACIFIC
STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW...MUCH COOLER
TEMPERATURES AND GUSTY WINDS THIS WEEKEND.
&&
.DISCUSSION...INCREASING MID AND UPPER LEVEL MOISTURE IN SOUTHERLY
TO SOUTHWESTERLY FLOW THIS MORNING. 12Z KTWC SOUNDING HAD A
PRECIPITABLE WATER OF .47 INCHES BUT LATEST BLENDED SATELLITE TRENDS
ARE OVER .5 WITH 1 INCH VALUES DOWN AROUND HERMOSILLO. WITH THE
UPWARD TREND EXPECTED TO CONTINUE WE WILL LIKELY APPROACH 3/4 OF
AN INCH LATER TODAY AND THIS EVENING. VERY LIGHT QPF VALUES BUT
SPRINKLES TO VERY LIGHT SHOWERS WILL BE COMMON AFTER 1 PM OR SO.
LATEST HRRR REFLECTS THIS WELL AND CURRENT FORECAST HANDLES THINGS
FINE. TEMPERATURE COLUMN SUPPORTS ANOTHER 80 TODAY BUT WITH THE
MOISTURE INCREASE AND LACK OF SOLAR INSOLATION SOMETHING IN THE
LOWER 70S IS MORE LIKELY.
LATEST MODEL TRENDS GREATLY INCREASING CONFIDENCE FOR WEEKEND
SYSTEM. 12Z NAM DOVETAILS NICELY INTO STRONG SYSTEM FOR OUR AREA
OVER THE WEEKEND ON 00Z ECMWF TRENDS. NEW GFS HAS A MORE SIGNIFICANT
MOISTURE FIELD FOR OUR PART OF THE STATE. WE WILL LIKELY HIT THE
WEEKEND FORECAST HARDER WITH THE AFTERNOON PACKAGE.
&&
.PREV DISCUSSION...FORECAST PROBLEMS FOR TODAY WILL BE THE POTENTIAL
FOR MEASURABLE RAIN AND HIGHS THIS AFTERNOON. SATELLITE IMAGERY THIS
MORNING SHOWED A SIGNIFICANT BATCH OF TROPICAL MOISTURE APPROACHING
THE AREA FROM THE SW. THIS MOISTURE WILL OVERSPREAD THE AREA THIS
MORNING. THE WEAK DISTURBANCE SEEN WELL OFF THE NRN BAJA COAST THIS
MORNING WILL MOVE ACROSS SRN AZ/NRN SONORA THIS AFTERNOON INTO THIS
EVENING. THE WEAK DYNAMICS ASSOCIATED WITH THIS DISTURBANCE WILL
PRODUCE LOTS OF VIRGA... SPRINKLES AND LIGHT MEASURABLE SHOWERS. QPF
VALUES WILL BE RATHER LIGHT...MOSTLY LESS THAN 0.05". COULD SEE UP
TO A TENTH IN THE HUACHUCAS AND CHIRICAHUAS. BEST CHANCES FOR
MEASURABLE WILL BE FROM TUCSON SOUTH AND EAST. THE OTHER MAIN
FORECAST PROBLEM OF THE DAY IS TEMPERATURES. LATEST MOS GUIDANCE
ALONG WITH 850-700 MB THICKNESS NUMBERS SUGGEST MUCH COOLER THAN
CURRENT FORECAST ESPECIALLY IN AREAS THAT WILL HAVE LOTS OF CLOUD
COVER AND LIGHT SHOWERS. THE LAST FIVE MOS GUIDANCE RUNS FROM GFS
MODEL HAVE BEEN GOING COOLER WITH EACH RUN. HAVE TO TAKE THAT IS
CONSIDERATION BUT NOT GO AS COLD AS THE GFS IS SUGGESTING THIS
AFTERNOON. FOR EXAMPLE 68 FOR TUCSON AND 66 FOR DOUGLAS. DECIDED TO
CUT HIGHS 4-8 DEGREES FROM INHERITED FORECAST IN AREAS WHERE PRECIP
IS POSSIBLE. WARM NATURE OF THIS MOISTURE WILL KEEP SNOW LEVELS
ABOVE MOUNTAIN PEAKS. LOT TO SAY FOR A LIGHT PRECIP EVENT...BUT ITS
BEEN AWHILE.
NEXT TROF WILL PASS THROUGH THE STATE ON THURSDAY...BRINGING A
SLIGHT CHANCE OF SHOWERS TO THE EAST CENTRAL MOUNTAINS.
SLIGHTLY WARMER FRIDAY AS SHORT WAVE RIDGE PASSES THROUGH IN ADVANCE
OF STRONGER PACIFIC STORM. THIS STORM WILL IMPACT THE AREA THIS
WEEKEND WITH WIDESPREAD VALLEY RAIN AND MOUNTAIN SNOW. AT THIS TIME
LOOKS LIKE SNOW LEVELS COULD BE AS LOW AS THE 6500-7000 FOOT LEVEL
WITH SIGNIFICANT AMOUNTS LIKELY. QPF VALUES COULD BE IN THE 0.20" TO
0.75" RANGE IN THE VALLEYS AND OVER AN INCH IN THE MOUNTAINS. STAY
TUNED AS THIS GETS FINE TUNED AS THE WEEK PROGRESSES. HIGHS THIS
WEEKEND WILL BE MUCH COOLER WITH HIGHS ON SATURDAY 8-11 DEGREES
COOLER THAN FRIDAY AND THEY WILL BE BELOW NORMAL FOR THE FIRST SINCE
THE FIRST 7 DAYS OF FEBRUARY.
&&
.AVIATION...FORECAST PERIOD THROUGH 26/18Z.
BKN-OVC CLOUDS AOA 10K FT AGL WILL CONTINUE ACROSS SE AZ THROUGH
26/09Z WITH PARTIAL CLEARING WED MORNING. SCT 6-8K FT ABOVE VALLEY
FLOORS AND OBSCURED MT TOPS IN ISOLD -SHRA ARE MOST LIKELY BTWN
25/21Z AND 26/06Z. SURFACE WIND GENERALLY LESS THAN 10 KTS THRU
26/18Z ALTHOUGH GUSTS 15-20 KTS PSBL NEAR -SHRA. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...SEVERAL DISTURBANCES WILL MOVE ACROSS THE REGION
OVER THE NEXT WEEK. THE FIRST TWO MAY BRING LIGHT SHOWERS TODAY INTO
THURSDAY. ASSOCIATED PERIODS OF CLOUD COVER WILL KEEP DAYTIME
TEMPERATURES COOLER THAN OF LATE...ALTHOUGH THEY WILL REMAIN ABOVE
NORMAL. NIGHTTIME TEMPERATURES WILL ALSO BE ABOVE NORMAL THE NEXT
FEW NIGHTS.
WIDESPREAD SIGNIFICANT PRECIPITATION IS NOT EXPECTED UNTIL A
STRONGER PACIFIC STORM SYSTEM APPROACHES SOUTHERN ARIZONA LATE THIS
WEEK WITH THE BEST CHANCE FOR PRECIPITATION LOOKING LIKE SATURDAY.
BREEZY CONDITIONS ARE FORECAST IN ADVANCE OF THIS SYSTEM FROM
THURSDAY THROUGH SATURDAY AND COOLER TEMPERATURES WILL ACCOMPANY
THE PRECIPITATION THIS WEEKEND.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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MEYER/DROZD
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
910 AM MST TUE FEB 25 2014
.SYNOPSIS...
DRY WESTERLY FLOW IS EXPECTED TO CONTINUE INTO EARLY FRIDAY ACROSS
THE REGION...KEEPING TEMPERATURES ABOVE NORMAL...RISING INTO THE
UPPER 70S TO LOW 80S EACH DAY ACROSS THE LOWER DESERTS...WITH
PERIODS OF HIGH CLOUDS PASSING OVERHEAD FROM TIME TO TIME. A
DRAMATIC CHANGE IN THE WEATHER IS THEN EXPECTED FROM LATE FRIDAY
INTO THE UPCOMING WEEKEND AS A VERY STRONG...AND WET PACIFIC STORM
MOVES INTO THE DESERT SOUTHWEST. THIS STORM IS EXPECTED TO BRING
WIDESPREAD SIGNIFICANT RAINFALL...AND MUCH COOLER TEMPERATURES TO
THE REGION.
&&
.DISCUSSION...
SUBTROPICAL MOISTURE IN THE FORM OF MID AND HIGH CLOUDS CONTINUES TO
STREAM NORTHEASTWARD ACROSS SOUTHERN AZ AHEAD OF A WEAK VORT MAX
NEAR PUERTO PENASCO. LATEST RADAR IMAGERY SHOWS SOME WEAK ECHOES
ACROSS SE AZ AND HI-RES WRF GUIDANCE ALONG WITH THE HRRR SUGGEST
SPRINKLES MAY CLIP PORTIONS OF EASTERN MARICOPA...PINAL AND SOUTHERN
GILA COUNTIES. FORECAST HAS BEEN UPDATED THIS MORNING TO INCREASE
CLOUD COVER AND ADD THE MENTION OF SLIGHT CHANCE SPRINKLES THROUGH
LATE THIS AFTERNOON. OTHERWISE...THE FORECAST REMAIN IN GOOD SHAPE.
&&
.PREVIOUS DISCUSSION...
TODAY THROUGH WEDNESDAY NIGHT...
DRY WESTERLY FLOW ALOFT WILL CONTINUE OVER THE REGION RESULTING IN A
CONTINUATION OF UNSEASONABLY WARM TEMPERATURES ALONG WITH PERIODS OF
HIGH CLOUDS FROM TIME-TO-TIME...AND LIGHT WINDS.
THURSDAY...
MODELS CONTINUE TO BRING A WEAK SHORTWAVE EASTWARD INTO THE GREAT
BASIN/4-CORNERS REGION DURING THE DAY ON THURSDAY. ALTHOUGH THE
LATEST MODEL RUNS STILL KEEP MOST OF THE MOISTURE AND DYNAMICS WELL
TO OUR NORTH...THE LATEST GEM AND EURO MODEL SUITES NOW ARE
FORECASTING A SLIGHT CHANCE FOR SPRINKLES...OR LIGHT SHOWERS OVER
THE HIGHEST ELEVATIONS OF SOUTHERN GILA COUNTY...AS THE CLOUD BASES
LOWER TO AROUND...OR JUST BELOW 10K FEET BRIEFLY ON THURSDAY.
THUS...HAVE INCREASED POPS OVER THAT REGION INTO THE SLIGHT CHANCE
RANGE TO REFLECT THESE CHANGES. HOWEVER...IT STILL APPEARS THAT THE
MAIN IMPACTS FROM THIS SYSTEM WILL BE ONLY TO BRING GUSTY WINDS TO
SOUTHEAST CA WEDNESDAY AFTERNOON AND EVENING...AND TO INCREASE
CLOUDINESS OVER THE REGION.
FRIDAY AND SATURDAY...
IT NOW APPEARS THAT IT IS ALMOST CERTAIN THAT WE WILL SEE A MAJOR
CHANCE IN THE WEATHER FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.
IN FACT...ALL OF THE LATEST MODEL RUNS ARE EVEN MORE BULLISH WITH
THIS SYSTEM THEN THEY WERE ON PREVIOUS RUNS. THERE IS NOW EXCELLENT
AGREEMENT BETWEEN THE EURO...GFS...AND GEM THAT THIS SYSTEM...WHICH
IS NOW TRACKING EASTWARD ACROSS THE CENTRAL PACIFIC SOUTH OF THE
ALEUTIAN CHAIN...WILL NOW PICK UP COPIOUS AMOUNTS OF MOISTURE AS IT
INTERACTS WITH A VERY STRONG (180KT) PACIFIC JET THAT EXTENDS ALL
THE WAY EASTWARD FROM SOUTHERN JAPAN (130E) TO NORTHEAST OF HAWAII
(ABOUT 150W). ALL THREE MODELS NOW PUSH THE SYSTEM INLAND
EARLIER...INTO SOUTHERN CA BY FRIDAY MORNING...THEN SLOWLY ACROSS
OUR CWA FROM LATE FRIDAY INTO EARLY SUNDAY. LATEST GFS PWAT
FORECASTS NOW PUSH A PLUME OF 1 INCH OR GREATER PWATS INTO...AND
ACROSS OUR CWA LATE FRIDAY AND SATURDAY. BOTH THE GFS AND EURO
FORECAST SOUNDINGS FOR KPHX ARE NOW SHOWING A VERY DEEP NEARLY
SATURATED MOISTURE LAYER...ALL THE WAY FROM THE SFC TO 35K FEET
MOVING IN ON SATURDAY...WITH STRONG SW-LY WINDS THROUGH THE ENTIRE
COLUMN...SOMETHING WE DON/T SEE VERY OFTEN AROUND HERE.
ALL THREE MODELS HAVE ALSO GREATLY INCREASED THEIR QPF FORECASTS.
THEY NOW ARE FORECASTING STORM TOTAL RAINFALL AMOUNTS OF 0.25-0.50
OF AN INCH FOR THE LOWER ELEVATIONS OF SE CA AND SW AZ...0.75-1.25
INCH FOR JOSHUA TREE NB AND ACROSS THE LOWER ELEVATIONS OF
SOUTH-CENTRAL ARIZONA...AND 1 TO 2 INCHES ACROSS THE HIGHER TERRAIN
OF SOUTH-CENTRAL ARIZONA. ALTHOUGH WIDESPREAD HYDRO ISSUES ARE VERY
UNLIKELY...DUE TO THE VERY DRY ANTECEDENT CONDITIONS...THERE WOULD
BE LIKELY SOME SMALL STREAM AND URBAN FLOODING ISSUES IF THESE
RAINFALL AMOUNTS DUE VERIFY.
BASED ON THESE UPDATED FORECAST...I HAVE GREATLY INCREASED POPS
ACROSS OUR WESTERN ZONES LATE FRIDAY AND PUSHED POPS INTO THE LIKELY
TO CATEGORICAL RANGE FOR MUCH OF OUR CWA ON SATURDAY. IN
ADDITION...I HAVE LOWERED HIGH TEMPS FURTHER ACROSS SOUTH-CENTRAL
ARIZONA ON SATURDAY...INTO THE LOW TO MID 60S AS THE LIKELY STEADY
RAIN AND THICK CLOUD COVER SHOULD KEEP TEMPS WELL BELOW NORMAL...A
RATHER RAW AND WET DAY FOR A VERY BUSY SLATE OF OUTDOOR ACTIVITIES
THAT ARE PLANNED ACROSS THE GREATER PHX AREA. ON THE OTHER
HAND...SNOWFALL CONCERNS ACROSS OUR CWA APPEAR TO BE A
NON-ISSUE...AS THE SUBTROPICAL ORIGIN OF THE AIRMASS IS EXPECTED TO
KEEP SNOW LEVELS MAINLY AOA 7000FT. AHEAD OF THE SYSTEM...WE ALSO
NOW EXPECT STRONG SOUTH TO SOUTHWESTERLY WINDS ON FRIDAY AFTERNOON
ACROSS SOUTHEAST CA AND THE LOWER CO RIVER VALLEY...WITH WIND SPEEDS
APPROACHING ADVISORY CRITERIA AT SOME LOCATIONS.
SUNDAY THROUGH TUESDAY...
SOME LINGERING SHOWERS ARE LIKELY ON SUNDAY...AND MAYBE EVEN INTO
MONDAY ACROSS SOUTH-CENTRAL ARIZONA AS GENERAL TROUGHINESS HANGS
BACK OVER OUR REGION...BUT FURTHER SIGNIFICANT RAINFALL IS NOW
EXPECTED AT THIS TIME. NEXT TUESDAY SHOULD SEE WARMER...AND DRIER
CONDITIONS AS RIDGING ATTEMPTS TO REBUILD BACK OVER THE DESERT
SOUTHWEST.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
CONTINUED HIGH PRESSURE ALOFT TODAY INTO WEDNESDAY...HOWEVER IT WILL
BE A DIRTY RIDGE ALLOWING CONSIDERABLE MID/HI CLOUDS TO OVERSPREAD
THE TERMINALS. EXPECT SCT-BKN MID AND HI LEVEL DECKS FROM 12K FEET
ON UP NEXT 24 HOURS...WITH THE DEEPEST MOISTURE ACROSS THE CENTRAL
AZ DESERT TAF SITES. WINDS TO REMAIN QUITE LIGHT AND VARIABLE WITH
WEAK DIURNAL SIGNALS AT KIWA AND KPHX TODAY AND TONIGHT. NO AVIATION
CONCERNS NEXT 24 HOURS AT ANY AIRFIELD.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
A FAST MOVING DISTURBANCE PASSING BY TO THE NORTH WILL LEAD TO
AFTERNOON BREEZY CONDITIONS THURSDAY...AND CAUSE HUMIDITIES TO
BECOME ELEVATED WITH MOST DESERTS CLIMBING ABOVE 20 PERCENT.
OTHERWISE HIGH TEMPERATURES WILL STAY ABOVE SEASONAL NORMALS. HIGH
PRESSURE ALOFT WILL BRIEFLY RETURN FRIDAY FOR CONTINUED ABOVE NORMAL
HIGH TEMPERATURES...HOWEVER MOISTURE WILL INCREASE FROM THE WEST
AHEAD OF AN APPROACHING WET PACIFIC LOW PRESSURE SYSTEM...AND A
CHANCE OF SHOWERS WILL DEVELOP ACROSS THE WESTERN DESERTS DURING THE
AFTERNOON HOURS. BREEZY TO WINDY CONDITIONS WILL ALSO DEVELOP BY
AFTERNOON...ESPECIALLY FROM THE COLORADO RIVER VALLEY WESTWARD. MUCH
COOLER AND VERY MOIST AND UNSETTLED CONDITIONS ARE EXPECTED THIS
WEEKEND AS THE AFOREMENTIONED PACIFIC LOW MOVES EASTWARD AND ACROSS
THE AREA...BRINGING PERIODS OF RAIN OR RAIN SHOWERS TO BOTH THE
DESERTS AND HIGHER TERRAIN...BEGINNING FRIDAY NIGHT AND CONTINUING
ALL THE WAY INTO SUNDAY. BREEZY CONDITIONS WILL ACCOMPANY THIS
PASSING SYSTEM BOTH SATURDAY AND SUNDAY. ON MONDAY...A SOMEWHAT
DRIER NORTHWEST FLOW ALOFT WILL BUILD INTO THE AREA BEHIND THE
EXITING LOW PRESSURE SYSTEM...LEADING TO LESS WIND AND SLIGHT
WARMING WHICH WILL BRING HIGH TEMPERATURES BACK TOWARDS SEASONAL
NORMALS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...PERCHA
AVIATION...CB
FIRE WEATHER...CB
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
252 PM MST TUE FEB 25 2014
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 252 PM MST TUE FEB 25 2014
SHORT TERM FORECAST THROUGH THIS EVENING IS BASED ON RAP MODEL TRENDS
THAT SNOW WILL EXPAND SOUTHWARD OVER ROUTT COUNTY EARLY THIS
AFTERNOON. AS OF 21Z...STEAMBOAT LAKE WEB CAM INDICATE THAT SNOW
HAS REACHED HAHNS PEAK VICINITY...BUT NO MOUNTAIN TOP OBSCURATION
NEAR STEAMBOAT SPRINGS. EXPECT THIS TO CHANGE WITHIN THE NEXT
COUPLE OF HOURS AS LEADING EDGE OF BAROCLINIC ZONE AND DECENT
GRADIENT NORTHWEST FLOW LEADS TO OROGRAPHIC SNOW OVER THE MT
ZIRKEL WILDERNESS AREA AND THE PARK RANGE. RAP MODEL INDICATES
RAIN/SNOW BAND MAY EXTEND AS FAR WEST AS MAYBELL AND MEEKER LATE
THIS AFTERNOON AS THE MOISTURE BAND SLIDES SOUTH AND EAST.
PRIMARY CONCERN IS THAT THE AMPLIFYING UPSTREAM RIDGE AXIS HAS
PINCHED OFF THE PACIFIC MOISTURE STREAM INTO NORTHWEST COLORADO...
THIS IS EVIDENT ON THE SATELLITE IMAGES. NOT SURE WHETHER THE
FORECASTED SNOW AMOUNTS FOR THE PARK RANGE WILL REACH THE UPPER
RANGE OF AROUND 7 INCHES...BUT RAP QPF STILL INDICATE THAT A FEW
INCHES OF SNOW REMAIN POSSIBLE. WITH SNOW OBSERVED AT RIVERTON
AND LANDER IN WEST CENTRAL WYOMING...GIVING CREDENCE THAT THE SNOW
IS ON THE WAY. LESSER AMOUNTS OF SNOW IS ANTICIPATED FOR THE FLAT
TOP MOUNTAINS AND GORE RANGE (VAIL PASS)...DO NOT THINK THAT AN
EXPANSION OF THE WINTER WEATHER ADVISORY IS NECESSARY. MOISTURE
STREAM SLIDES EAST AFTER MIDNIGHT WITH MID LEVEL DRY STABLE AIR
ADVECTING INTO NORTHWEST COLORADO...THIS WILL SHUT DOWN OROGRAPHIC
SNOW FAIRLY QUICKLY LATE TONIGHT.
FOR THE SERN HALF OF THE FORECAST AREA THROUGH TONIGHT...CLEAR AND
DRY WEATHER IS EXPECTED FOR THE NEXT 12 TO 18 HOURS.
WEST COAST RIDGE SHIFTS INLAND ON WEDNESDAY BUT BROAD ISENTROPIC
UPGLIDE WILL RESULT IN AN INCREASE OF MID/HIGH LEVEL CLOUDS FROM
THE SOUTHWEST. NAM AND GFS SHOWING HINTS OF MOUNTAIN TOP SPOTTY
SNOW WEDNESDAY AFTERNOON AND NIGHT. SOMETIMES THIS IS OVERDONE BUT
THE TREND WILL BE FOR INCREASING CLOUDS WITH CIRROSTRATUS EVOLVING
INTO ALTOSTRATUS. WITH THE INCREASED CLOUD COVER...EXPECT
RELATIVELY MILD CONDITIONS WEDNESDAY NIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 252 PM MST TUE FEB 25 2014
THE FORECAST AREA COMES UNDER THE INFLUENCE OF THE SUBTROPICAL JET
THROUGH THE WEEKEND. THIS TYPICALLY BRINGS BETTER MOISTURE BUT
MILDER TEMPERATURES WITH ASSOCIATED STORMS. BREEZY TO WINDY
CONDITIONS ARE EXPECTED IN THE MTNS AND HIGH VALLEYS...INTO THE
LOWER VALLEYS WITH SHOWERS.
THURSDAY...A TRANSIENT RIDGE PASSES IN THE EARLY AFTERNOON WITH
DEEPENING MOISTURE IN SW FLOW. 700MB SPECIFIC HUMIDITIES CLIMB TO
4 G/KG IN THE AFTERNOON. THERE IS SOME MODEL DISAGREEMENT ON
TEMPERATURES AND SNOW LEVELS. A COMPROMISE PUTS THE SNOW LEVELS
AROUND 7500FT/8500FT NORTH/SOUTH. THE DEEPEST MOISTURE IS IN THE
SOUTHERN-CENTRAL MTNS. MARGINAL INSTABILITY PRODUCES AREAS OF
STRONGER SHOWERS AND BRIEFLY LOWER SNOW LEVELS.
THURSDAY NIGHT...THE BEST FORCING OCCURS AS THE SUBTROPICAL JET
PUSHES INTO THE SOUTH THEN LIFTS INTO THE CENTRAL ZONES. SNOW
LEVELS LOWER INTO THE NORTHERN VALLEYS...TO 7500FT SOUTH.
FRIDAY IS A BRIEF BREAK UNDER AS A LOCAL RIDGE IS AMPLIFIED AHEAD
OF THE NEXT STRONG STORM BRINGING WARM ADVECTION. MOISTURE REMAINS
AT 4 G/KG SO SHOWERS INCREASE INTO THE AFTERNOON.
FRIDAY NIGHT-SATURDAY NIGHT...THE NEXT SUBTROPICAL JET STREAK LIFTS
THE EASTERN UTAH FRIDAY NIGHT THEN ACROSS WESTERN COLORADO ON
SATURDAY. AGAIN THERE IS A CONVECTIVE COMPONENT FRIDAY NIGHT INTO
SATURDAY. THERE IS AGAIN A CONVECTIVE COMPONENT TO THIS STORM.
SNOWFALL WILL FAVOR THE SOUTHERN AND CENTRAL MTNS. SNOW LEVELS
AROUND 7000FT. SATURDAY NIGHT IS TROUGH PASSAGE WITH NW FLOW
DEVELOPING. SNOW LEVEL DROPS TO AROUND 5000FT BUT WILL FAVOR THE
NW-FACING SLOPES OF THE COLORADO MTNS.
SUNDAY-TUESDAY...ARE NOW A FLAT ZONAL FLOW WITH THE POLAR FRONT
JET SETTLING INTO WYOMING THEN RAKING THE NORTH ON MONDAY. EXPECT
COOLER TEMPERATURES THROUGH THESE PERIODS WITH THE BEST SNOWFALL
FAVORING THE NORTHERN MTNS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 252 PM MST TUE FEB 25 2014
VFR PREVAILS AT ALL TAF SITES THROUGH THE PERIOD. THERE IS A 10 TO 20
PERCENT CHANCE OF -SN AT KASE AND KEGE BETWEEN 00Z AND 12Z
TONIGHT.
WIDESPREAD LIGHT SNOW IS EXPECTED EAST OF A LINE FROM DWX-KSBS-10E
KEGE-10E KASE FROM 20Z THIS AFTERNOON THROUGH 06Z THIS EVENING.
EXPECT MOUNTAIN OBSCURATIONS WITH LOW CIGS/VIS FROM LIGHT SNOW AND
FOG. SLOW IMPROVEMENT IS EXPECTED AFTER 06Z WITH NO MOUNTAIN
OBSCURATIONS AFTER 15Z.
MID/HIGH LEVEL CLOUDS INCREASE ON WEDNESDAY WITH ISOLATED MOUNTAIN
TOP FLURRIES. THIS SHOULD HAVE NO IMPACT AT MOUNTAIN AIRPORT
SITES.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 8 AM MST WEDNESDAY ABOVE 9000 FEET
FOR THE COZ004.
UT...NONE.
&&
$$
SHORT TERM...PF
LONG TERM...JOE
AVIATION...PF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1252 PM EST TUE FEB 25 2014
.SYNOPSIS...
UNSEASONABLY COLD WEATHER WILL CONTINUE RIGHT INTO THIS WEEKEND.
THERE WILL BE A FEW OPPORTUNITIES FOR SOME SNOW SHOWERS...BUT NO
MAJOR STORMS ARE EXPECTED THIS WEEK AND DRY WEATHER WILL DOMINATE.
A MORE SIGNIFICANT STORM MAY AFFECT OUR REGION BY THE LATE PORTION
OF THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1250 PM UPDATE...
CURRENT FORECAST ON TRACK. CONTINUED RISK FOR A FEW FLURRIES/SNOW
SHOWERS AS SHORTWAVE SWINGS THROUGH BUT DRY AIR IN THE LOW LEVELS
WILL BE A LIMITING FACTOR.
PREVIOUS DISCUSSION...
CLOUDS HAVE OVERSPREAD THE REGION THIS MORNING AND WILL PERSIST
THROUGH THE AFTERNOON GIVEN ABUNDANT 850 MB RH. MID LEVEL
SHORTWAVE AND SFC TROF MOVES THROUGH THIS AFTERNOON AND WILL BRING
A FEW SNOW SHOWERS/FLURRIES. HOWEVER...AREAL COVERAGE SHOULD BE
LIMITED AS LOWEST LEVELS ARE QUITE DRY WITH DEWPOINTS WELL DOWN
INTO THE SINGLE NUMBERS AND LOW LEVEL LAPSE RATES ARE NOT QUITE AS
ROBUST AS YESTERDAY. HRRR SHOWING JUST A FEW LIGHT SNOW SHOWERS
THIS AFTERNOON AND WILL SCALE POPS BACK TO ISOLD. MAX TEMPS WILL
BE MOSTLY IN THE 20S TO AROUND 30 IN THE COASTAL PLAIN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT...A MORE AMPLIFIED NORTHERN STREAM SHORTWAVE WILL BE
APPROACHING FROM THE GREAT LAKES. WEAK RIDGING AHEAD OF THIS
FEATURE WILL RESULT IN MAINLY DRY CONDITIONS.
WEDNESDAY...THE MODELS ARE IN GENERAL AGREEMENT THAT LOW
PRESSURE EMERGING OFF THE MID ATLANTIC COAST WILL PASS WELL
SOUTHEAST OF THE BENCHMARK. THERE IS STILL A NORTHERN STREAM
SHORTWAVE...WHICH ALSO PRODUCES A WEAK SURFACE WAVE. THIS FEATURE
WILL HAVE LIMITED MOISTURE.
THIS SETS UP A BRIEF WINDOW WEDNESDAY MORNING INTO WEDNESDAY
AFTERNOON WHERE CONDITIONS ARE FAVORABLE ENOUGH WITHIN THE PRIME
SNOW GROWTH REGION TO GET DECENT SNOW ACCUMULATION. STILL THINKING
MOST OF SOUTHERN NEW ENGLAND WILL BE AN INCH OR LESS...WITH A FEW
SPOTS TOWARD CAPE COD AND THE ISLANDS SEEING UP TO 2 INCHES OR SO.
MANY OF THE SNOW SHOWERS WILL BE EXITING THE COAST BY MID TO LATE
AFTERNOON AS DRIER MID LEVEL AIR RUSHES INTO THE REGION.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
*/ HIGHLIGHTS...
- UNSEASONABLY COLD TEMPERATURES PREVAIL THROUGHOUT THE FORECAST
- LIGHT SNOW FOR THURSDAY UNDER BLUSTERY WINDS
- WIND CHILL ADVISORIES MAY BE NEEDED FOR FRIDAY MORNING
- ANOTHER SHOT OF LIGHT SNOW SATURDAY
- A MORE SIGNIFICANT STORM APPEARING LIKELY SUNDAY INTO MONDAY
*/ OVERVIEW AND MODEL PREFERENCE...
CONSIDERING THE PROXIMITY AND EVOLUTION OF THE POLAR LOW COMBINED
WITH WESTERN CONUS RIDGING...A PROGRESSIVE FLOW PATTERN IS FAVORED.
SOME UNCERTAINTY AS TO THE DOWNSTREAM RIDGE STRENGTH ASSOCIATED WITH
THE NORTH-CENTRAL ATLANTIC HIGH...YET ENSEMBLE MEMBERS IN GOOD
AGREEMENT OF A SLIGHTLY +NAO. ANTICIPATING AN ACTIVE WEATHER PATTERN
WITH TROUGHING PREFERRED OVER THE NE CONUS. GREATEST UNCERTAINTY
LIES IN INDIVIDUAL MORPHOLOGY OF DISTURBANCES AND SUBSEQUENT SURFACE
OUTCOMES. THOUGH A MODEL-WEIGHTED CONSENSUS BLEND APPROACH HAS BEEN
CONDUCTED WITH THIS FORECAST...WILL OUTLINE OVERALL CONFIDENCE IN
THE DISCUSSION BELOW.
*/ DAY-TO-DAY DETAILS...
WEDNESDAY NIGHT INTO THURSDAY NIGHT...
POLAR WAVE INVOKES A CLIPPER LOW ACROSS THE NORTHERN GREAT LAKES
INTO NORTHERN NEW ENGLAND. ATTENDANT ARCTIC FRONT IS THE FOCUS FOR
LIGHT SNOW ACTIVITY. CONSIDERING THE DISTURBANCE IS CUT-OFF FROM SUB-
TROPICAL MOISTURE AND IS MORE CONTINENTAL POLAR WITH REGARDS TO
AIRMASS...MAIN CONCERN IS UPON BLUSTERY WINDS AND ARCTIC AIR.
BOUNDARY LAYER MIXING POTENTIALLY ALL THE WAY TO H7 AHEAD OF THE
FRONT THURSDAY AND IMMEDIATELY IN WAKE OF THE FRONT BY THURSDAY
EVENING WILL ALLOW FOR THE MIX-DOWN OF 30 TO 40 MPH GUSTS AT THE
SURFACE /INITIALLY SOUTHWESTERLY TURNING WESTERLY BEHIND THE FRONT/.
COMBINING THIS ALONG WITH UNSEASONABLY COLD TEMPERATURES /H85 AROUND
-20C BY FRIDAY MORNING/ AND THERE IS MODERATE CONFIDENCE TOWARDS THE
ISSUANCE OF WIND CHILL ADVISORIES OVER THE NORTH AND WEST INTERIOR
HIGH TERRAIN /ESPECIALLY FOR THURSDAY NIGHT INTO FRIDAY MORNING/.
LOW CONFIDENCE TOWARDS THE NEED FOR WIND ADVISORIES...FEEL WIND
GUSTS WILL REMAIN BELOW THRESHOLDS. WINDS DIMINISH TOWARDS FRIDAY
MORNING.
LIKELY GALES OVER THE WATERS WITH THE NEED FOR FREEZING SPRAY
ADVISORIES WITH COLD OCEAN TEMPERATURES. HIGH CONFIDENCE. LOWS IN
THE SINGLE DIGITS WITH HIGHS IN THE LOW- TO MID-20S.
FRIDAY INTO FRIDAY NIGHT...
ARCTIC HIGH PRESSURE BUILDS OVER THE REGION WITH UNSEASONABLY COLD
AIR. WITH H85 TEMPERATURES AROUND -20C DURING THE DAY...EXPECTING
HIGHS AROUND THE UPPER-TEENS TO LOW 20S. POSSIBLE WIND CHILL
ADVISORIES FOR THE MORNING SHOULD DROP OFF AS SURFACE TEMPERATURES MODERATE
AND WINDS BECOME LIGHT AND VARIABLE.
WILL KEEP THE FORECAST PERIOD DRY. INCREASING CLOUDS LATE AHEAD OF
THE WEEKEND DISTURBANCE IN ADDITION TO SOUTHWEST FLOW ALOFT AND
MODERATING TEMPERATURE TREND WHICH WILL ALLOW FOR SLIGHTLY WARMER
OVERNIGHT LOWS.
SATURDAY INTO SATURDAY NIGHT...
WEAK PACIFIC WAVE DISTURBANCE ABLE TO TAP INTO GULF MOISTURE IS
SEEMINGLY DEAMPLIFIED UNDER THE WEIGHT OF A REINFORCING ARCTIC FRONT
AND ACCOMPANYING HIGH PRESSURE. NOT EXPECTING MUCH THREAT WITH THE
WEAK NATURE OF THE SYSTEM...SOME LIGHT SNOW POSSIBLE WITH THE
POTENTIAL OF OCEAN-EFFECT SNOWS IN WAKE OF THE ARCTIC FRONT...
OTHERWISE WILL SEE THE CONTINUANCE OF UNSEASONABLY COLD TEMPS.
SUNDAY AND BEYOND...
CONSIDERING ENSEMBLE MEANS...HAVE HIGH CONFIDENCE OF A LOW FROM THE
GULF COAST LIFTING NORTHWARD THROUGH THE OHIO RIVER VALLEY TOWARDS
THE SOUTH-COAST OF NEW ENGLAND. BUT VARIANCE AND SPREAD AMONG MODEL
SOLUTIONS IS STILL TOO HIGH TOWARDS KNOWING EXACT OUTCOMES. EVEN THE
DETERMINISTIC ECMWF HAS RUN-TO-RUN WOBBLES IN THE LOW TRACK AND
POSITION THAT MAKE FOR VARYING FORECASTS. WILL AWAIT BETTER MODEL
CONSENSUS BEFORE GOING ANY FURTHER ON THE DETAILS.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH WEDNESDAY NIGHT/...
THROUGH TONIGHT...HIGH CONFIDENCE. VFR. CIGS 040-080 WITH GUSTY
W/NW WINDS UP TO 25 KT THIS AFTERNOON. LOW PROB FOR A FEW FLURRIES
AND BRIEF MVFR VSBYS. CLEARING SKIES AND DIMINISHING WIND THIS
EVENING. MID LEVEL CLOUDS RETURN LATE TONIGHT.
WEDNESDAY...HIGH CONFIDENCE. MAINLY VFR...BUT A PERIOD OF MVFR
POSSIBLE AS SNOW SHOWERS MOVE THROUGH THE REGION DURING MORNING
AND EARLY AFTERNOON. LOW PROB OF BRIEF IFR IN ANY HEAVIER
SQUALLS. PARTIAL CLEARING AFT 18Z FROM WEST TO EAST. WEST WIND
GUSTS 20-25 KT DEVELOPING IN THE AFTERNOON.
WEDNESDAY NIGHT...HIGH CONFIDENCE. VFR.
KBOS TERMINAL...LOW CONFIDENCE IN ANY FLURRIES THIS AFTERNOON.
HIGHER CONFIDENCE FOR A PERIOD OF SNOW SHOWERS WEDNESDAY.
KBDL TERMINAL...LOW CONFIDENCE IN ANY FLURRIES THIS AFTERNOON.
HIGHER CONFIDENCE FOR A PERIOD OF SNOW SHOWERS WEDNESDAY.
OUTLOOK...THURSDAY THROUGH SATURDAY NIGHT...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...MODERATE CONFIDENCE.
MVFR-IFR WITH -SN. SW WINDS GUSTING UP TO AROUND 35 KTS DURING THE
DAY THURSDAY...BACKING WESTERLY BY EVENING AND DIMINISHING TOWARDS
MORNING.
FRIDAY INTO FRIDAY NIGHT...MODERATE CONFIDENCE.
VFR. LIGHT AND VARIABLE WINDS. INCREASING MID- TO HIGH-CLOUDS LATE.
SATURDAY INTO SATURDAY NIGHT...MODERATE CONFIDENCE.
MVFR-IFR WITH -SN. BREEZY SOUTHWEST WINDS BACKING W/NW TOWARDS
EVENING.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH WEDNESDAY...HIGH CONFIDENCE.
GUSTY WEST TO NORTHWEST WINDS CONTINUES ACROSS THE COASTAL WATERS.
SMALL CRAFT ADVISORIES WILL CONTINUE. PRESSURE GRADIENT IS A
LITTLE WEAKER TODAY...SO WILL DROP THE ADVISORIES FOR BOSTON
HARBOR AND NARRAGANSETT BAY. A BIT OF A LULL EXPECTED THIS
MORNING ACROSS THE OTHER NEAR SHORE WATERS...BUT NOT ENOUGH OF ONE
TO DROP THE ADVISORY COMPLETELY. WOULD JUST HAVE TO REISSUE ONE
LATER THIS MORNING AND AFTERNOON AS WINDS PICK UP AGAIN.
WINDS WILL EVENTUALLY DIMINISH BELOW 25 KT TONIGHT...BEFORE
INCREASING AGAIN WEDNESDAY. ROUGH SEAS WILL BE SLOWER TO SUBSIDE
TONIGHT...ESPECIALLY ACROSS THE OUTER COASTAL WATERS. INCREASING
WINDS SHOULD RESULT IN BUILDING SEAS FOR WEDNESDAY...ESPECIALLY
TOWARDS THE OUTER WATERS. AREAS OF FREEZING SPRAY EXPECTED.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...HIGH CONFIDENCE.
SOUTHWEST GALES AHEAD OF A FRONT WITH WIND GUSTS UP TO 40 KTS...
CONTINUING WHILE BACKING WESTERLY WITH FRONTAL PASSAGE...GRADUALLY
DIMINISHING TOWARDS FRIDAY MORNING. COMBINED WITH SEAS AND COLD
OCEAN TEMPERATURES AND THERE IS THE LIKELY NEED FOR FREEZING SPRAY
ADVISORIES AS MODERATE FREEZING SPRAY IS ANTICIPATED. LIGHT SNOW
ALSO POSSIBLE WHICH MAY MAKE FOR VISIBILITY RESTRICTIONS ON THE
WATERS.
FRIDAY INTO FRIDAY NIGHT...MODERATE CONFIDENCE.
HIGH PRESSURE BUILDS OVER THE WATERS THROUGH THE DAY. BOTH THE
THREAT OF FREEZING SPRAY AND GALE-FORCE WINDS DROP TOWARDS MIDDAY.
SEAS ALLOWED TO DIMINISH. SMALL-CRAFT ADVISORIES LIKELY.
SATURDAY INTO SATURDAY NIGHT...MODERATE CONFIDENCE.
BREEZY SOUTHWEST FLOW TURNING W/NW WITH AN ARCTIC FRONTAL PASSAGE BY
EVENING. WINDS ARE ANTICIPATED TO REMAIN BELOW 25 KTS. SEAS LIKELY
TO AMPLIFY WITH FETCH. LIGHT SNOW ALSO POSSIBLE WHICH COULD MAKE FOR
VISIBILITY RESTRICTIONS ON THE WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR
ANZ230>237-251.
SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...KJC
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...KJC/SIPPRELL
MARINE...BELK/SIPPRELL
AREA FORECAST DISCUSSION
NWS BOISE ID
948 AM MST TUE FEB 25 2014
.DISCUSSION...FRONT REMAINS STATIONARY JUST TO THE NORTH OF THE
CWA THIS MORNING. MOISTURE AND SHOWERS ALONG THE FRONT WILL
DECREASE AS AN UPPER RIDGE AXIS TO OUR WEST BUILDS INTO OUR AREA.
RADAR ALREADY SHOWING A DECREASING TREND IN SHOWER COVERAGE ACROSS
THE NORTH AND THAT TREND WILL CONTINUE THROUGH THE AFTERNOON.
MORNING UPDATE WILL INCLUDE LOWER POPS AND LOWER QPF AMOUNTS
TODAY.
&&
.AVIATION...EXPECT MVFR/LOCAL LIFR CONDITIONS IN RAIN AND SNOW
OVER THE WEST CENTRAL IDAHO AND BOISE MOUNTAINS AND THE HIGHER
TERRAIN OF BAKER COUNTY THIS MORNING. SNOW LEVEL WILL BE NEAR 5K
FT MSL. CONDITIONS WILL GRADUALLY IMPROVE THROUGH THE
AFTERNOON...WITH MAINLY VFR TONIGHT. ELSEWHERE VFR WILL PREVAIL
WITH BROKEN TO OVERCAST CEILINGS ABOVE 10K FT MSL. SURFACE WINDS
WILL BE LIGHT. WINDS ALOFT WILL BE NORTHWEST UP TO 25 KTS AT 10K
FT MSL.
&&
.PREV DISCUSSION...
SHORT TERM...TODAY THROUGH WEDNESDAY...UPDATED HIGH TEMPERATURES
AS MORNING WEATHER BALLOON SOUNDING INDICATED ANOTHER 3 TO 5
DEGREES OF WARMING BELOW 10K FT MSL. /END UPDATE/ DEEP MOISTURE
AXIS ACROSS OREGON AND CENTRAL IDAHO WILL COMBINE WITH AN UPPER
LEVEL TROUGH DROPPING THROUGH THE NORTHERN ROCKIES FOR NUMEROUS
SHOWERS ACROSS THE WEST CENTRAL MOUNTAINS MAINLY THIS MORNING.
CLOUDINESS WILL DECREASE ACROSS SOUTHERN AREAS SO EXPECT ANOTHER
MILD LATE AFTERNOON WITH HIGHS IN THE 50S TO AROUND 60. PWAT ARE
ABOVE NORMAL AT 0.50 INCHES VS 0.33 INCHES BUT AMOUNTS WON`T BE
ENOUGH FOR ANY HEADLINES...MORE LIKE A HIGH POP/LOW QPF EVENT. THE
MORNING SNOW LEVEL AROUND 5500 FEET WILL RESULT IN A RAIN/SNOW MIX
AT MCCALL FROM 5 TO 9 AM THEN CHANGE BACK TO RAIN BEFORE TAPERING
THIS EVENING. HRRR AND 0Z/6Z NAM KEEP BANDED SHOWERS GOING AT
VARIOUS LOCATIONS ACROSS NE OREGON OR CENTRAL IDAHO THIS AFTERNOON
SO HAVE SCATTERED SHOWERS LATER TODAY IN THE HIGHER TERRAIN OF THE
PAYETTE NF/BOISE NF AS WELL AS SOUTH PARTS OF THE WALLOWA WHITMAN
FOREST IN OREGON. AS THE UPPER LEVEL RIDGE MOVES OVER THE AREA
TONIGHT THROUGH WEDNESDAY MORNING EXPECT DRY WX. WEDNESDAY...IN
THE AFTERNOON OVER OREGON AND LATE AFTERNOON OVER THE SW IDAHO
MOUNTAINS THERE SHOULD BE ENOUGH MOISTURE AN LIFT AHEAD OF THE
NEXT INCOMING SYSTEM FOR LOW CHANCES OF RAIN...AND HIGH MOUNTAIN
SNOW ABOVE 6500-7200 FEET. TEMPERATURES PEAK WEDNESDAY AROUND 8-12
DEGREES ABOVE NORMAL.
LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...FORECAST REMAINS ON
TRACK FOR AN ACTIVE PATTERN THROUGH EARLY NEXT WEEK. THE FIRST ROUND
OF PRECIPITATION WILL BEGIN WEDNESDAY NIGHT THROUGH THURSDAY AS A
WEAK UPPER TROUGH MOVES ACROSS THE REGION FROM THE SOUTHWEST TO
NORTHEAST. SNOW LEVELS REMAIN ABOVE 6000 FEET FOR MODERATE SNOW
ACCUMULATIONS ON THE MOUNTAIN PEAKS. LIGHT RAIN AMOUNTS EXPECTED IN
THE VALLEYS. A BRIEF BREAK ON FRIDAY WILL BE FOLLOWED BY MORE
SHOWERS OVER THE WEEKEND AS AN UPPER LEVEL TROUGH CROSSES CALIFORNIA
AND MOVES OVER THE GREAT BASIN. A MAJORITY OF GUIDANCE FAVORS THE
WARMER ECMWF INCLUDING MOST OF THE GFS ENSEMBLES MAKING THE
OPERATIONAL GFS THE ODD MODEL OUT. THE UPPER LOW WEAKENS AND SPLITS
AS IT MOVES INLAND ACROSS CALIFORNIA ON FRIDAY. THE NORTHERN SPLIT
MOVES ACROSS THE REGION ON SATURDAY KEEPING THE ARCTIC COLD FRONT
NORTH AND EAST OF THE AREA. EXPECT PRECIPITATION ACROSS THE AREA
THROUGH MONDAY WITH THE MOUNTAINS BEST CHANCE FOR SNOW ON SUNDAY.
TEMPERATURES WILL BE NEAR NORMAL TO SLIGHTLY ABOVE NORMAL.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...BW
AVIATION.....JT
PREV SHORT TERM...VM
PREV LONG TERM....JS
AREA FORECAST DISCUSSION...CORRECTED
NWS GOODLAND KS
200 PM MST TUE FEB 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 113 PM MST TUE FEB 25 2014
MAIN FOCUS IN THE SHORT TERM WAS TEMPERATURES TODAY THROUGH
TOMORROW AND PRECIPITATION THIS AFTERNOON AND OVERNIGHT. HIGH
TEMPERATURES THIS AFTERNOON WERE ADJUSTED SINCE SOME LOCATIONS
REACHED THEIR HIGHS AROUND 18/19Z. AFTER 18Z COLDER AIR MOVED INTO
NORTHERN LOCATIONS WHERE TEMPERATURES HAVE REMAINED FAIRLY
STAGNANT OR INCREASED BY A DEGREE OR TWO. PORTIONS OF NORTHWEST
KANSAS AND EASTERN COLORADO ALONG AND SOUTH OF I-70 HAVE SEEN
TEMPERATURES IN THE UPPER TEENS TO MID 20S...BUT THIS APPEARS TO
BE THE PEAK OF TODAY`S HIGH TEMPERATURES AS THE COLDER AIR BEGINS
TO MOVE IN. SNOW HAS DEVELOPED OVER SOUTHWEST NEBRASKA AND IS
MOVING INTO NORTHWEST KANSAS ASSOCIATED WITH A FAIRLY STRONG AREA
OF FRONTOGENESIS. AS THE SHORTWAVE TROUGH IN MONTANA CONTINUES TO
PUSH SOUTHEAST AND THE STRONG AREA OF FRONTOGENESIS MOVES
SOUTHEAST AND THEN SOUTH...SNOWFALL WILL CONTINUE THROUGH THE
EVENING OVER MOST OF THE TRI-STATE REGION. THIS WILL BE A QUICK
MOVING WAVE AND THE GFS...NAM...AND RAP ALL SHOW PRECIPITATION OUT
OF THE FORECAST AREA BY 06Z. SINCE THE SYSTEM MOVES QUICKLY...SNOW
ACCUMULATIONS WILL ONLY BE AROUND HALF AN INCH SOUTH AND EAST TO 2
INCHES NORTH AND NORTHWEST. CLOUD COVER WILL STICK AROUND A LITTLE
AFTER 06Z...WITH MOST OF THE CWA BEING CLEAR BY 15Z. LOWS TONIGHT
WILL DROP DOWN INTO THE SINGLE DIGITS AS HIGH PRESSURE SETTLES
INTO THE CWA. NORTHERN AREAS WILL SEE LOWS AROUND 1 DEGREE ABOVE
ZERO TO NEAR ZERO WHILE AREAS FURTHER SOUTH AND WEST WILL SEE LOWS
AROUND 5 TO 10 ABOVE ZERO.
AS SURFACE HIGH PRESSURE SLIDES EAST-SOUTHEAST...ANOTHER SHORTWAVE
TROUGH WILL MOVE THROUGH. NO PRECIPITATION IS EXPECTED WITH THE
NEXT TROUGH SINCE DRIER AIR MOVES IN SO HAVE KEPT THE FORECAST DRY
FOR TOMORROW. TEMPERATURES WILL BE DIVIDED WITH HIGHS OVER THE
NORTHERN HALF OF THE TRI-STATE REGION IN THE UPPER 30S TO NEAR 40
AND THE SOUTHERN HALF/SOUTH-SOUTHWEST PORTION OF THE TRI-STATE
REGION IN THE LOW TO MID 40S. MODELS MAY HAVE BEEN PICKING UP ON
THE SNOW COVER IN THE NORTHERN AREA OF THE CWA WHICH IS WHY THE
TEMPERATURES THERE ARE A BIT LOWER. USED A COMBINATION OF CONSALL
AND SREF FOR TOMORROW`S TEMPERATURES TO TREND THEM DOWNWARD IN THE
SOUTHERN PORTIONS OF THE CWA SINCE THEY SEEMED TO BE TOO HIGH TO
ACCOUNT FOR ANY SNOWFALL THOSE AREAS MIGHT RECEIVE TONIGHT. WEST
TO SOUTHWEST WINDS TOMORROW COULD ALSO BECOME BREEZY AROUND 18Z AS
THE SHORTWAVE TROUGH PASSES THROUGH AND DAYTIME MIXING
INCREASES...BUT ONLY HAVE SUSTAINED WINDS AROUND 10 TO 20 MPH
WITH GUSTS AROUND 25 TO 30 MPH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 224 AM MST TUE FEB 25 2014
WEDNESDAY NIGHT-THURSDAY...PROGRESSIVE SHORTWAVE RIDGE SHOULD HELP
KEEP DRY CONDITIONS IN PLACE THROUGH THESE PERIODS...WITH A SLIGHT
MODERATION OF THE AIR MASS OVER OUR CWA AS STATIONARY FRONT ALONG
FRONT RANGE LIFTS EAST WITH LEE TROUGH DEVELOPMENT. HIGH TEMPS
THURSDAY SHOULD BE NEAR NORMAL FOR WESTERN LOCATIONS (MID 40S TO
NEAR 50F)...WITH COOLER TEMPS IN THE MID/UPPER 30S FURTHER
NORTHEAST.
THURSDAY NIGHT-FRIDAY...NEXT IN A SERIES OF QUICK MOVING SHORTWAVE
TROUGHS WILL MOVE ACROSS THE REGION WITH ARCTIC AIR MASS DROPPING
BACK OVER WESTERN KS. BEST CHANCE FOR MEASURABLE SNOW APPEARS TO BE
LATE THURSDAY NIGHT THROUGH FRIDAY MORNING...WHEN MODELS ARE
ADVERTISING BETTER LARGE SCALE ASCENT. TIMING OF COLD FRONT IS A
LITTLE SLOWER WITH MAIN CAA FRIDAY AFTERNOON...WHICH MAY RESULT IN
QUITE A GRADIENT FROM THE NORTH-SOUTH OVER OUR CWA (LIKELY FALLING
TEMPS ACROSS THE NORTH).
FRIDAY NIGHT-TUESDAY...DESPITE DIFFERENCES IN THE LARGE SALE PATTERN
THROUGH THE EXTENDED PERIODS...MODELS HAVE COME INTO BETTER
AGREEMENT ON STUBBORN ARCTIC AIR MASS REMAINING IN PLACE OVER OUR
CWA...WITH ECMWF NOW TRENDING EVEN COLDER THAN THE LAST 3 RUNS OF
THE GFS. REGARDING LARGE SCALE PATTERN...ECMWF SHOWS MORE OF A
QUASI-ZONAL PATTERN WITH LOWER HEIGHTS SHIFTED SOUTH...WHILE GFS
SHOWS MORE OF A SPLIT FLOW PATTERN WITH THE NORTHERN STREAM HOLDING
MORE INFLUENCE OVER OUR CWA. EITHER SOLUTION FAVORS REINFORCING SHOTS
OF COLD ARCTIC AND AND PROLONGED BELOW NORMAL TEMPERATURES THROUGH AT
LEAST EARLY NEXT WEEK...ALONG WITH A SERIES OF QUICK MOVING
SHORTWAVES PASSING THROUGH THE REGION.
I TRENDED HIGH/LOW TEMPS DOWN TO ACCOUNT FOR THE COLDER PATTERN
CURRENT MODEL RUNS ARE ZEROING IN ON. EXPECTED CLOUD COVER
COMPLICATING HIGHS/LOWS...AND THERE ARE STILL DIFFERENCES BETWEEN
MODELS ON MAGNITUDE OF COOLING...SO I DID NOT FAVOR THE COLDEST
GUIDANCE DURING THIS UPDATE. THE TYPE OF AIR MASS CURRENTLY
ADVERTISED BY EVEN THE "WARMER" GFS WOULD SUPPORT OVERNIGHT LOWS IN
THE SINGLE DIGITS BELOW ZERO OVER PARTS OF OUR CWA DESPITE CLOUD
COVER (AND IF WE CLEAR OUT MUCH COLDER THAN THIS). CLOUDS COULD
LIMIT DAYTIME WARMING...AND ONGOING FORECAST OF TEENS-LOW 20S FOR
HIGHS MAY BE OPTIMISTIC. REGARDING PRECIP CHANCES...MANY OF THE
PERIODS IN THE EXTENDED HAVE SLIGHT CHANCE-CHANCE POPS...AND I DIDNT
SEE THE NEED TO REMOVE THESE BASED ON THE ACTIVE PATTERN ALOFT...AND
LINGERING BAROCLINIC ZONE ACROSS EASTERN COLORADO. BEST CHANCE FOR
MEASURABLE SNOW IN THESE PERIODS DOES APPEAR TO BE SAT-SAT NIGHT
WHEN A SLIGHTLY STRONGER SHORTWAVE TROUGH MOVES OUT OF THE SW US
ACROSS THE SOUTHERN PLAINS. THERE IS LITTLE IN THE WAY OF MOISTURE
RETURN/MOISTURE ADVECTION...SO ANY SNOWFALL WE SEE THROUGH THESE
PERIODS SHOULD BE ON THE LIGHT SIDE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1044 AM MST TUE FEB 25 2014
A STATIONARY BOUNDARY TO THE WEST OF THE TRI STATE AREA WILL
CONTINUE TO TO BRING OVERCAST CONDITIONS TO THE TRI STATE AREA. A
COLD FRONT WILL MOVE THROUGH THE HIGH PLAINS ABOUT 0Z...WHICH WILL
BRING SOME CHANCES FOR LIGHT SNOW SHOWERS TO BOTH TERMINALS. SOME
GUIDANCE HAS VISIBILITIES IN THE SNOW SHOWERS REDUCED INTO THE IFR
CATEGORY...BUT WAS NOT CONFIDENT ENOUGH AT THIS POINT TO DROP
VISIBILITIES QUITE YET IN THIS FORECAST.
SNOW SHOULD TAPER OFF AFTER 6Z...AND A HIGH PRESSURE WILL MOVE
INTO THE AREA TO PROVIDE VFR CONDITIONS AND DECREASING CLOUD COVER
FOR THE REST OF THE TAF PERIOD AFTER 10Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...ALW/JSL
LONG TERM...DR
AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
157 PM MST TUE FEB 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 113 PM MST TUE FEB 25 2014
MAIN FOCUS IN THE SHORT TERM WAS TEMPERATURES TODAY THROUGH
TOMORROW AND PRECIPITATION THIS AFTERNOON AND OVERNIGHT. HIGH
TEMPERATURES THIS AFTERNOON WERE ADJUSTED SINCE SOME LOCATIONS
REACHED THEIR HIGHS AROUND 18/19Z. AFTER 18Z COLDER AIR MOVED INTO
NORTHERN LOCATIONS WHERE TEMPERATURES HAVE REMAINED FAIRLY
STAGNANT OR INCREASED BY A DEGREE OR TWO. PORTIONS OF NORTHWEST
KANSAS AND EASTERN COLORADO ALONG AND SOUTH OF I-70 HAVE SEEN
TEMPERATURES IN THE UPPER TEENS TO MID 20S...BUT THIS APPEARS TO
BE THE PEAK OF TODAY`S HIGH TEMPERATURES AS THE COLDER AIR BEGINS
TO MOVE IN. SNOW HAS DEVELOPED OVER SOUTHWEST NEBRASKA AND IS
MOVING INTO NORTHWEST KANSAS ASSOCIATED WITH A FAIRLY STRONG AREA
OF FRONTOGENESIS. AS THE SHORTWAVE TROUGH IN MONTANA CONTINUES TO
PUSH SOUTHEAST AND THE STRONG AREA OF FRONTOGENESIS MOVES
SOUTHEAST AND THEN SOUTH...SNOWFALL WILL CONTINUE THROUGH THE
EVENING OVER MOST OF THE TRI-STATE REGION. THIS WILL BE A QUICK
MOVING WAVE AND THE GFS...NAM...AND RAP ALL SHOW PRECIPITATION OUT
OF THE FORECAST AREA BY 06Z. SINCE THE SYSTEM MOVES QUICKLY...SNOW
ACCUMULATIONS WILL ONLY BE AROUND HALF AN INCH SOUTH AND EAST TO 2
INCHES NORTH AND NORTHWEST. CLOUD COVER WILL STICK AROUND A LITTLE
AFTER 06Z...WITH MOST OF THE CWA BEING CLEAR BY 15Z. LOWS TONIGHT
WILL DROP DOWN INTO THE SINGLE DIGITS AS HIGH PRESSURE SETTLES
INTO THE CWA. NORTHERN AREAS WILL SEE LOWS AROUND 1 DEGREE ABOVE
ZERO TO NEAR ZERO WHILE AREAS FURTHER SOUTH AND WEST WILL SEE LOWS
AROUND 5 TO 10 ABOVE ZERO.
AS SURFACE HIGH PRESSURE SLIDES EAST-SOUTHEAST...ANOTHER SHORTWAVE
TROUGH WILL MOVE THROUGH. NO PRECIPITATION IS EXPECTED WITH THE
NEXT TROUGH SINCE DRIER AIR MOVES IN SO HAVE KEPT THE FORECAST DRY
FOR TOMORROW. TEMPERATURES WILL BE DIVIDED WITH HIGHS OVER THE
NORTHERN HALF OF THE TRI-STATE REGION IN THE UPPER 30S TO NEAR 40
AND THE SOUTHERN HALF/SOUTH-SOUTHWEST PORTION OF THE TRI-STATE
REGION IN THE LOW TO MID 40S. MODELS MAY HAVE BEEN PICKING UP ON
THE SNOW COVER IN THE NORTHERN AREA OF THE CWA WHICH IS WHY THE
TEMPERATURES THERE ARE A BIT LOWER. USED A COMBINATION OF CONSALL
AND SREF FOR TOMORROW`S TEMPERATURES TO TREND THEM DOWNWARD IN THE
SOUTHERN PORTIONS OF THE CWA SINCE THEY SEEMED TO BE TOO HIGH TO
ACCOUNT FOR ANY SNOWFALL THOSE AREAS MIGHT RECEIVE TONIGHT. WEST
TO SOUTHWEST WINDS TOMORROW COULD ALSO BECOME BREEZY AROUND 18Z AS
THE SHORTWAVE TROUGH PASSES THROUGH AND DAYTIME MIXING INCREASES...BUT ONLY
HAVE SUSTAINED WINDS AROUND 10 TO 20 MPH WITH GUSTS AROUND 25 TO
30 MPH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 224 AM MST TUE FEB 25 2014
WEDNESDAY NIGHT-THURSDAY...PROGRESSIVE SHORTWAVE RIDGE SHOULD HELP
KEEP DRY CONDITIONS IN PLACE THROUGH THESE PERIODS...WITH A SLIGHT
MODERATION OF THE AIR MASS OVER OUR CWA AS STATIONARY FRONT ALONG
FRONT RANGE LIFTS EAST WITH LEE TROUGH DEVELOPMENT. HIGH TEMPS
THURSDAY SHOULD BE NEAR NORMAL FOR WESTERN LOCATIONS (MID 40S TO
NEAR 50F)...WITH COOLER TEMPS IN THE MID/UPPER 30S FURTHER
NORTHEAST.
THURSDAY NIGHT-FRIDAY...NEXT IN A SERIES OF QUICK MOVING SHORTWAVE
TROUGHS WILL MOVE ACROSS THE REGION WITH ARCTIC AIR MASS DROPPING
BACK OVER WESTERN KS. BEST CHANCE FOR MEASURABLE SNOW APPEARS TO BE
LATE THURSDAY NIGHT THROUGH FRIDAY MORNING...WHEN MODELS ARE
ADVERTISING BETTER LARGE SCALE ASCENT. TIMING OF COLD FRONT IS A
LITTLE SLOWER WITH MAIN CAA FRIDAY AFTERNOON...WHICH MAY RESULT IN
QUITE A GRADIENT FROM THE NORTH-SOUTH OVER OUR CWA (LIKELY FALLING
TEMPS ACROSS THE NORTH).
FRIDAY NIGHT-TUESDAY...DESPITE DIFFERENCES IN THE LARGE SALE PATTERN
THROUGH THE EXTENDED PERIODS...MODELS HAVE COME INTO BETTER
AGREEMENT ON STUBBORN ARCTIC AIR MASS REMAINING IN PLACE OVER OUR
CWA...WITH ECMWF NOW TRENDING EVEN COLDER THAN THE LAST 3 RUNS OF
THE GFS. REGARDING LARGE SCALE PATTERN...ECMWF SHOWS MORE OF A
QUASI-ZONAL PATTERN WITH LOWER HEIGHTS SHIFTED SOUTH...WHILE GFS
SHOWS MORE OF A SPLIT FLOW PATTERN WITH THE NORTHERN STREAM HOLDING
MORE INFLUENCE OVER OUR CWA. EITHER SOLUTION FAVORS REINFORCING SHOTS
OF COLD ARCTIC AND AND PROLONGED BELOW NORMAL TEMPERATURES THROUGH AT
LEAST EARLY NEXT WEEK...ALONG WITH A SERIES OF QUICK MOVING
SHORTWAVES PASSING THROUGH THE REGION.
I TRENDED HIGH/LOW TEMPS DOWN TO ACCOUNT FOR THE COLDER PATTERN
CURRENT MODEL RUNS ARE ZEROING IN ON. EXPECTED CLOUD COVER
COMPLICATING HIGHS/LOWS...AND THERE ARE STILL DIFFERENCES BETWEEN
MODELS ON MAGNITUDE OF COOLING...SO I DID NOT FAVOR THE COLDEST
GUIDANCE DURING THIS UPDATE. THE TYPE OF AIR MASS CURRENTLY
ADVERTISED BY EVEN THE "WARMER" GFS WOULD SUPPORT OVERNIGHT LOWS IN
THE SINGLE DIGITS BELOW ZERO OVER PARTS OF OUR CWA DESPITE CLOUD
COVER (AND IF WE CLEAR OUT MUCH COLDER THAN THIS). CLOUDS COULD
LIMIT DAYTIME WARMING...AND ONGOING FORECAST OF TEENS-LOW 20S FOR
HIGHS MAY BE OPTIMISTIC. REGARDING PRECIP CHANCES...MANY OF THE
PERIODS IN THE EXTENDED HAVE SLIGHT CHANCE-CHANCE POPS...AND I DIDNT
SEE THE NEED TO REMOVE THESE BASED ON THE ACTIVE PATTERN ALOFT...AND
LINGERING BAROCLINIC ZONE ACROSS EASTERN COLORADO. BEST CHANCE FOR
MEASURABLE SNOW IN THESE PERIODS DOES APPEAR TO BE SAT-SAT NIGHT
WHEN A SLIGHTLY STRONGER SHORTWAVE TROUGH MOVES OUT OF THE SW US
ACROSS THE SOUTHERN PLAINS. THERE IS LITTLE IN THE WAY OF MOISTURE
RETURN/MOISTURE ADVECTION...SO ANY SNOWFALL WE SEE THROUGH THESE
PERIODS SHOULD BE ON THE LIGHT SIDE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1044 AM MST TUE FEB 25 2014
A STATIONARY BOUNDARY TO THE WEST OF THE TRI STATE AREA WILL
CONTINUE TO TO BRING OVERCAST CONDITIONS TO THE TRI STATE AREA. A
COLD FRONT WILL MOVE THROUGH THE HIGH PLAINS ABOUT 0Z...WHICH WILL
BRING SOME CHANCES FOR LIGHT SNOW SHOWERS TO BOTH TERMINALS. SOME
GUIDANCE HAS VISIBILITIES IN THE SNOW SHOWERS REDUCED INTO THE IFR
CATEGORY...BUT WAS NOT CONFIDENT ENOUGH AT THIS POINT TO DROP
VISIBILITIES QUITE YET IN THIS FORECAST.
SNOW SHOULD TAPER OFF AFTER 6Z...AND A HIGH PRESSURE WILL MOVE
INTO THE AREA TO PROVIDE VFR CONDITIONS AND DECREASING CLOUD COVER
FOR THE REST OF THE TAF PERIOD AFTER 10Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...ALW/JSL
LONG TERM...DR
AVIATION...MK
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
212 PM EST TUE FEB 25 2014
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE TRACKS ACROSS THE MID ATLANTIC THIS
AFTERNOON. HIGH PRESSURE BRIEFLY BUILDS INTO THE AREA THIS
EVENING AHEAD OF ANOTHER QUICK MOVING TROUGH...WHICH TRACKS ACROSS
THE REGION WEDNESDAY MORNING. HIGH PRESSURE RETURNS WEDNESDAY
NIGHT AND THURSDAY. A STRONG COLD FRONT DROPS THROUGH THE REGION
THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A MID-LEVEL TROUGH WILL MOVE ACROSS THE NORTHERN MID ATLANTIC
THIS AFTN. LATEST RUC SHOWS A COUPLE OF VORTICITY MAXES...DECENT
LIFT AND LO LVL MOISTURE...WILL SWING FM THE OH VALLEY EWRD ACRS
NRN VA/MD/DE THIS AFTN. BASED ON THIS SCENARIO...HAVE UPDATED TO A
SLGT CHC OF SNOW ACRS THE NRN THIRD OF THE AREA...GENERALLY ALNG
AND N OF A FARMVILLE...TO RICHMOND...TO MELFA LINE. NO
ACCUMULATION IS EXPECTED. THIS SLGT CHC WILL END FM W TO E FM ARND
MIDDAY THRU THE AFTN. WILL CONTINUE WITH A SLGT CHC OF -RA OVER
SE PORTIONS. CLOUD COVER WILL LIMIT HIGH TEMPERATURES...WITH LOW-
LEVEL THICKNESSES SUPPORTING UPPER 30S TO AROUND 40 NE...TO THE
UPPER 40S TO AROUND 50 SW.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
THE MID/UPPER LEVEL FLOW PATTERN REMAINS ZONAL TONIGHT INTO
WEDNESDAY. ANOTHER QUICK MOVING SHORTWAVE TROUGH RACES ACROSS THE
MID ATLANTIC REGION LATE TONIGHT INTO WEDNESDAY MORNING...AFTER HIGH
PRESSURE BRIEFLY RETURNS THIS EVENING. PARTIAL CLEARING THIS EVENING
WILL ALLOW LOWS TO DROP INTO THE MID 20S N...TO LOW 30S SE. CLOUDS
QUICKLY INCREASE AGAIN AFTER MIDNIGHT ALLOWING TEMPERATURES TO
BECOME STEADY.
THIS TROUGH IS A LITTLE MORE VIGOROUS AND DIGS SOMEWHAT FARTHER S.
STILL THE PATTERN IS VERY PROGRESSIVE AND LIMITED WITH RESPECT TO
MOISTURE...SO NOT MUCH MORE THAN A ~3HR WINDOW FOR PRECIP IS
EXPECTED. LOW-LEVEL THICKNESSES WILL BE RATHER COLD...SO MAINLY -SN
IS EXPECTED FROM THE SW PIEDMONT TO THE EASTERN SHORE...WITH A MIX
OF -RA/SN IN THE TIDEWATER AND NE NC...AND MAINLY -RA FOR THE
IMMEDIATE ATLANTIC COAST. ANY ACCUMULATION (GENERALLY 0.5IN OR
LESS) WILL BE CONFINED FROM THE NW PIEDMONT COUNTIES TO THE LOWER MD
EASTERN SHORE WHERE SURFACE TEMPERATURES WILL BE THE COLDEST. DRYING
QUICKLY OVERSPREADS THE AREA FROM WEST TO EAST WEDNESDAY AFTERNOON.
HIGHS SHOULD RANGE FROM THE MID 30S OVER THE LOWER MD EASTERN
SHORE...TO THE MID 40S FROM THE RIC METRO S AND W.
DRY AND BREEZY CONDITIONS DEVELOP THURSDAY AFTER A CHILLY MORNING.
HIGHS SHOULD RISE INTO THE MID 40S N...TO LOW 50S S...AFTER MORNING
LOWS IN THE MID TEENS TO LOW 20S. A GUSTY WSW WIND OF 15-20
MPH...WITH GUSTS TO 25 MPH IS EXPECTED DURING THE AFTERNOON.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
25/00Z ECMWF ALONG WITH THE 25/00Z AND 06Z GFS EACH BRING MOST OF
THE AKQ CWA INTO THE WARM SECTOR NEXT MONDAY. THIS WILL HAVE A
SIGNIFICANT IMPACT ON TEMPERATURE (POTENTIALLY MUCH WARMER) AND
PRECIP-TYPE I.E. A WINTRY MIX VERSUS ALL RAIN. CONTINUITY WILL BE
MAINTAINED AT THIS TIME (COOLER SOLUTION)...BUT IT IS WORTHWHILE TO
MENTION THAT CONFIDENCE IS LOW WITH RESPECT TO THE LATTER PORTION
OF THE EXTENDED PERIOD.
PREVIOUS DISCUSSION...
COLDER WITH BELOW NORMAL TEMPS. A SPLIT FLOW WILL LEAD TO QUICK
SYSTM MOVEMENTS AND PERIODIC PCPN CHCS THRU PRD. LEANED TOWARD THE
ECMWF WITH RESPECT TO SFC FEATURES.
CANADIAN HIGH PRESSURE KEEPS IT DRY BUT COLD FRIDAY. LOWS THURS
NIGHT IN THE L-M20S XCPT A FEW UPR TEENS NRMLY COLDER SPOTS. HIGHS
FRI M30S-L40S. NEXT IN A SERIES OF SRN STREAM S/W`S PROGGED TO TRACK
ACROSS THE SOUTHERN MID ATLNTC REGION FRI NIGHT AND SAT. LATEST MODEL
GUIDANCE WANTS TO SHEAR THE PCPN OUT AS IT CROSSES THE MTS FRI NIGHT
WHILE TRACKING AN AREA OF MSTR FROM SRN VA ACROSS THE CAROLINAS LATE
FRI NITE AND SAT MORN. UPSHOT HERE WILL BE YET ANTHR SYSTM WITH LGT
AMOUNTS OF QPF. P-TYPE ISSUES ARISE GIVEN SFC TMPS AOB FREEZING AND
CRITICAL THICKNESSES. WILL CARRY LOW CHC POPS FOR SNOW NWRN HALF OF
FA...A BUFFER ZONE OF SNOW/SLEET DOWN TO VA/NC BORDER WITH A RAIN
SLEET MIX ACROSS NC LATE FRI NITE. LOWS M20S-L30S. CHC LIQUID POPS
ACROSS SERN SCTNS OF FA WITH A BUFFER ZONE OF MIXED RAIN/SNOW FRTHR
NW SAT MORNING. PCPN ENDS MOST AREAS ARND NOON XCPT SOME LINGERING
RAIN CHCS AT THE COAST SAT AFTRN. HIGHS IN THE 40S.
ANTHR CANADIAN HIGH PRESSURE BUILDS INTO THE AREA SAT NIGHT THROUGH
SUNDAY NITE. DRY AND COLD WITH LOWS SAT NITE UPR TEENS-M20S. HIGHS
SUN M-U30S. LOWS SUN NIGHT IN THE 20S.
MODELS INDCTG ANTHR COMPLICATED SYSTM POISED TO MAKE A BEELINE FOR
THE MID ATLNTC RGN MONDAY. HIGH PRS TO THE NORTH ALLOWS FOR A WEDGE
TO SET UP AHEAD OF A MOISTURE LADEN SYSTM DVLPNG ACROSS THE DEEP
SOUTH. THE LOW PROGGED TO LIFT NORTH ACROSS THE RGN LATE MONDAY
ALONG WITH A COLD FRONTAL PASSAGE. MOISTURE PROGGED TO RIDE UP OVER
THE WEDGE PRODUCING A VARIETY OF WX ACROSS THE RGN SUN NITE AND MON
MORN WITH PCPN BCMG RAIN OVR ERN HALF OF FA MON. TO ERLY TO GET
SPECIFIC...BUT THIS SYSTM DOES BEAR WATCHING FOR THE PTNTL OF A
WINTER MIX OF PCPN SUNDAY NIGHT THROUGH MONDAY MORN. LOWS SUN NITE
25-30. HIGHS MON IN THE 30S AND 40S.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AN UPPER LEVEL DISTURBANCE PASSING ACROSS NORTHERN VA HAS HELPED
TO THICKEN/LOWER CLOUD DECK ACROSS THE AREA AND GENERATE A BAND OF
LIGHT TO MODERATE SNOW ACROSS THE LOWER MD EASTERN SHORE. RADAR
TRENDS INDICATE THAT THE BAND WILL ONLY AFFECT KSBY THROUGH 20Z.
VIS SATELLITE SHOWS CLEARING BEHIND THE WAVE...SO EXPECT CEILINGS
ACROSS THE AREA TO LIFT/CLEAR BY THIS EVENING.
LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST TUESDAY NIGHT INTO
WEDNESDAY MORNING...LIFTING OFFSHORE OF THE MID-ATLANTIC COAST
WEDNESDAY. THERE REMAINS THE POTENTIAL FOR A QUICK SHOT OF WINTRY
PRECIP OVER THE REGION LATE TUES NIGHT INTO EARLY WEDS MORNING.
ACCUMULATING SNOW IS EXPECT GENERALLY NORTH OF KRIC...INCLUDING
KSBY. ELSEWHERE...LIGHT RAIN WILL TRANSITION TO SNOW EARLY WEDS
MORNING. IFR CIGS/VSBYS APPEAR POSSIBLE ATTM EARLY WEDS MORNING AT
ALL TAF SITES. GUSTY NW WINDS ARE ALSO EXPECTED...ESPECIALLY NEAR
THE COAST. HIGH PRESSURE RETURNS WEDS AFTERNOON INTO THURSDAY
BEFORE A FAST MOVING CLIPPER COLD FRONT CROSSES THE REGION THURS.
&&
.MARINE...
HIGH PRESSURE BUILDS OVER THE WATERS TODAY...RESULTING IN SUB-SCA
CONDITIONS. SUB-SCA CONDITIONS CONTINUE INTO WEDS AS A COLD FRONT
APPROACHES FROM THE WEST. COLD FRONT WILL CROSS THE WATERS EARLY
WEDS AFTERNOON AS LOW PRESSURE LIFTS NEWD OFF THE SE COAST.
STRENGTHENING PRESSURE GRADIENT BTWN LOW PRESSURE OFF THE COAST AND
HIGH PRESSURE IN THE MIDWEST WILL COMBINE WITH CAA FOR POSSIBLE SCA
CONDITIONS WEDS AFTERNOON INTO WEDS EVENING. LOW-LEVEL WINDS LOOK
MARGINAL...BUT ANTICIPATE CAA TO BE STRONG ENOUGH TO PRODUCE SCA.
WILL HOLD OFF ON HEADLINES AS ITS LATE 3RD-EARLY 4TH PERIOD AND
CONDITIONS REMAIN MARGINAL. LOW PRESSURE LIFTS WELL OFFSHORE WEDS
NIGHT AS HIGH PRESSURE BUILDS IN FROM THE WEST. FLOW RETURNS TO THE
WSW THURS AS THE NEXT FRONT APPROACHES FROM THE WEST. FRONT WILL
CROSS THE WATERS LATE THURS. SCA CONDITIONS APPEAR LIKELY BEFORE THE
FRONT LATE WEDS MORNING AS THE GRADIENT STRENGTHENS...AND AFTER THE
FRONT AS CAA PRODUCES A STRONG NLY SURGE. HIGH PRESSURE QUICKLY
BUILDS OVER THE WATERS LATE THURS NIGHT...ENDING SCA CONDITIONS.
HIGH PRESSURE WILL REMAIN WEDGED OVER THE WATERS THROUGH THE
WEEKEND.
&&
.FIRE WEATHER...
PRECIPITATION HAS AVERAGED BELOW NORMAL DURING THE PAST WEEK.
ADDITIONALLY MINIMUM RH VALUES RANGED FROM 20-25% FROM THE EASTERN
VA PIEDMONT TO THE LOWER MD EASTERN SHORE SATURDAY AND SUNDAY...AND
FELL TO 15-20% MONDAY. THE ONLY EXCEPTIONS HAVE BEEN FAR SE VA AND
NE NC EAST OF THE CHOWAN RIVER. THIS HAS ALLOWED FINE FUELS TO DRY.
RAIN AND/OR SNOW IS POSSIBLE LATE TUESDAY NIGHT THROUGH WEDNESDAY
MORNING...WITH A LIGHT ACCUMULATION OF SNOW POSSIBLE FROM THE
NORTHERN NECK TO THE EASTERN SHORE. HOWEVER...PRECIPITATION AMOUNTS
WILL GENERALLY BE LESS THAN A TENTH OF AN INCH. DRY AIR QUICKLY
RETURNS WEDNESDAY AFTERNOON. BY THURSDAY AFTERNOON...MINIMUM RH
VALUES OF 15-25% ARE POSSIBLE ALONG WITH A SOUTHWEST WIND AROUND 15
MPH...WITH GUSTS TO 25 MPH AHEAD OF A COLD FRONT. THE NET RESULT IS
THE POTENTIAL FOR ENHANCED FIRE DANGER THURSDAY AFTERNOON. THE
PRIMARY QUESTION WILL BE WHETHER OR NOT THE PRESENCE OF DRY FINE
FUELS CAN OFFSET THE LIMITING FACTORS OF MOIST SOIL AND MOIST LARGER
FUELS. ADDITIONALLY...ENHANCED FIRE DANGER WILL BE ALL BUT
ELIMINATED ACROSS NE PORTIONS IF A LIGHT SNOW ACCUMULATION OCCURS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ/TMG
SHORT TERM...AJZ
LONG TERM...AJZ/MPR
AVIATION...SAM/DAP
MARINE...SAM
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
410 PM EST TUE FEB 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 PM EST TUE FEB 25 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A FAMILIAR PATTERN
FEATURING A DEEP UPR TROF OVER ERN NAMERICA DOWNSTREAM OF A RDG
ALONG THE W COAST. SHRTWV EMBEDDED IN THE NW FLOW IS STREAKING SEWD
THRU ONTARIO JUST N OF LK SUP. COLD FNT ASSOCIATED WITH THIS
DISTURBANCE HAS PASSED THRU THE CWA...AND H85 TEMPS AS LO AS -25C TO
-28C ARE PUSHING INTO UPR MI IN THE LLVL W FLOW. ALTHOUGH THERE IS A
GOOD DEAL OF ICE ON LK SUP...AREAS OF OPEN WATER OVER THE FAR WRN LK
AND OVER THE SCENTRAL E OF THE KEWEENAW HAVE ALLOWED A GOOD DEAL OF
LK CLD/SOME -SHSN TO FORM IN THE LLVL CAD. THE LK CLDS/SHSN APPEAR
TO BE MOST WDSPRD OVER THE NE HALF OF THE AREA CLOSER TO THE SHRTWV
PASSING THRU ONTARIO/ACCOMANPANYING DYNAMIC SUPPORT AND DEEPER MSTR.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LK EFFECT CLD/SHSN
TRENDS AND TEMPS/NEED FOR WIND CHILL HEADLINES.
LATE THIS AFTN/TNGT...AS THE H925 FLOW VEERS MORE TO THE NW THRU 00Z
IN THE WAKE OF SHRTWV PASSING BY TO THE N...EXPECT LK EFFECT
CLDS/SHSN TO SPREAD FARTHER TO THE S AND INLAND IN THE PRESENCE OF
LENGTHENING DAYTIME HEATING DESPITE DNVA/DEEP LYR QVECTOR DVGC IN
THE WAKE OF THE SHRTWV PASSAGE. H85 THERMAL TROF WITH TEMPS DOWN TO
-28/-29C IS FCST TO SHIFT THRU THE CWA BTWN 06Z-12Z AS THE LLVL FLOW
BACKS TO THE W BTWN SFC HI PRES SINKING TOWARD THE MID MS RIVER
VALLEY AND NEXT VIGOROUS SHRTWV DROPPING SEWD THRU SCENTRAL CANADA.
WITH A PERIOD OF LARGER SCALE QVECTOR DVGC...EXPECT CLRG OVER THE
INTERIOR...ALLOWING SFC TEMPS TO FALL WELL BLO ZERO AND INTO THE
TEENS BLO ZERO AT SOME PLACES UNDER DRY AIRMASS WITH PWAT UNDER 0.10
INCH. ALTHOUGH THERE ARE QUESTIONS AS TO WHETHER SFC WINDS WL
CONSISTENTLY SATISFY THE 10 MPH SPEED THRESHOLD FOR A WIND CHILL
ADVY...PLAN TO ISSUE AN ADVY FOR THE COLDER NW HALF OF THE CWA WITH
FAIRLY SHARP PRES GRADIENT/H925 WINDS IN THE 20-30KT RANGE UNDER H85
THERMAL TROF ENHANCING MIXING. LK EFFECT CLDS/-SHSN WL SHIFT FM THE
NW WIND SN BELTS BACK INTO AREAS IMPACTED BY W WINDS LATE TNGT.
ABSENCE OF DGZ WITHIN VERY COLD AIRMASS AND ICE COVER WL LIMIT SN
ACCUMS.
WED...AREA OF DEEP LYR QVECTOR CNVGC IN ADVANCE OF SHRTWV/SFC LO
DIGGING SEWD THRU NW ONTARIO WL OVERSPREAD UPR MI NW-SE BY EARLY
AFTN. IN THE ABSENCE OF ANY SGNFT MSTR INFLOW...SUSPECT DRYNESS OF
ANTECEDENT AIRMASS WL BE A SGNFT IMPEDIMENT TO OUTBRREAK OF PCPN. AS
THE FLOW SHIFTS TO THE SW...THERE IS POTENTIAL FOR SOME LK
MOISTENING/ENHANCEMENT OFF OF LK MI. BUT EXTENSIVE/GROWING ICE COVER
OVER THE N HALF OF LK MI WL TEND TO MITIGATE THIS IMPACT. TENDED
TOWARD THE HIER CHC/LIKELY POPS OVER THE NE HALF OF THE CWA TOWARD
SHARPER ISENTROPIC ASCENT ON THE 270K SFC /NEAR H7/ AND ALSO LATE IN
THE DAY OVER THE W WITH EXPECTED ARRIVAL OF ENHANCED LLVL CNVGC
ASSOCIATED WITH COLD FNT ATTENDANT TO CLIPPER LO REACHING NE LK SUP
BY 00Z THU.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 409 PM EST TUE FEB 25 2014
ANOTHER WAVE FROM THE TROUGH OVER EASTERN CANADA WILL BE QUICKLY
DIVING SOUTHEAST ACROSS THE UPPER GREAT LAKES REGION ON WEDNESDAY
EVENING. A 1000MB LOW WILL BE DROPPING SOUTHEAST ACROSS
NORTHEASTERN LAKE SUPERIOR AND THEN INTENSIFYING TO 995MB AS IT
MOVES OVER THE GEORGIAN BAY BY 12Z THURSDAY. MODELS CONTINUE TO BE
FAIRLY CONSISTENT WITH THE TRACK/INTENSITY/TIMING OF THE
LOW...WHICH LENDS CONFIDENCE TO THE FORECAST...ESPECIALLY WITH THE
WINDS. THE COMBINATION OF COLD AIR ADVECTION AND STRONG PRESSURE
RISES (10MB/6HR) BEHIND THE LOW BETWEEN 06Z AND 15Z THURSDAY SHOULD
LEAD TO A PERIOD OF GUSTY WINDS ACROSS MUCH OF UPPER MICHIGAN. THE
WORST CONDITIONS WILL BE IN THE EXPOSED AREAS NEAR LAKE SUPERIOR
FROM ONTONAGON EASTWARD. OVER THE KEWEENAW AND THEN AREAS FROM
MARQUETTE EASTWARD...MODELS ARE SHOWING 925MB WINDS IN THE 35-45KT
RANGE WITH THE HIGHEST VALUES FROM THE TIP OF THE KEWEENAW TO ALGER
COUNTY. WITH THE PASSAGE OF THE COLD FRONT ON WEDNESDAY
EVENING...THINK THERE WILL BE A PERIOD OF LIGHT SNOW BUT
ACCUMULATIONS SHOULD BE LESS THAN .5IN IN MOST AREAS. ALTHOUGH THIS
WON/T AMOUNT TO MUCH...IT WILL LEAD TO SOME BLOWING/DRIFTING SNOW.
THE WORST CONDITIONS WILL AGAIN BE OVER THE KEWEENAW...WHICH
ALREADY HAS LARGE MOUNDS/DRIFTS ON THE EDGES OF ROADWAYS THAT SHOULD
EASILY REDEVELOP OVER THE ROADS WITH THE STRONG WINDS AND A LITTLE
BIT OF SNOW. FARTHER EAST...THERE HAS BEEN SOME LIGHT LAKE EFFECT
AND WITH ICE REDEVELOPING EAST OF THE KEWEENAW THERE SHOULD BE AN
OPEN/FLAT AREA FOR THE SNOW TO MOVE ACROSS AND IMPACT ALGER COUNTY.
WITH M-28 EXPOSED TO THE LAKE EAST AND BETTER ICE COVERAGE EAST OF
SHOT POINT...THINK THERE WILL BE A GOOD POTENTIAL FOR
BLOWING/DRIFTING SNOW CAUSING ISSUES ON THE ROAD THROUGH MUNISING.
THE COLD AIR RECENTLY HAS LEAD TO ICE SPREADING OVER THE OPEN AREAS
THE DEVELOPED A COUPLE DAYS AGO AND FORTUNATELY...THINK THIS WILL
LIMIT THE AMOUNT OF LAKE EFFECT WITH THE NORTHWEST WINDS BEHIND THE
LOW WED NIGHT INTO THURSDAY. ALSO...WITH A HIGH PRESSURE RIDGE
QUICKLY MOVING IN TO THE U.P. FROM WEST TO EAST THURSDAY MORNING
INTO THURSDAY AFTERNOON...IT SHOULD DO TWO THINGS. BRING DRIER AIR
AND LIMIT THE ANY LAKE EFFECT INTENSITY AND ALSO LEAD TO QUICKLY
WEAKENING WINDS.
WITH THE PRECIPITATION...WIND...AND ALSO COLD
TEMPERATURES...HEADLINES WILL LIKELY BE NEEDED OVER ALL OF UPPER
MICHIGAN WEDNESDAY NIGHT INTO THURSDAY MORNING. WIND CHILL
TEMPERATURES ARE CURRENTLY FORECAST IN THE -25 TO -40 DEGREE RANGE
AND PUTS SOME NORTHERN AREAS ON BORDERLINE WIND CHILL WARNING
CRITERIA. OTHERWISE...THINK THE ENTIRE U.P. WOULD NEED A WIND CHILL
ADVISORY. SECOND...WITH THE REDUCED VISIBILITIES NEAR LAKE SUPERIOR
FROM FALLING/BLOWING/DRIFTING SNOW...WILL LIKELY NEED AT LEAST A
WINTER WEATHER ADVISORY FOR THE KEWEENAW PENINSULA AND ALGER COUNTY.
THE WINDS AND VISIBILITIES WILL LIKELY PRODUCE BRIEF PERIODS OF
BLIZZARD CONDITIONS IN THE KEWEENAW...BUT WITH THE MODELS ONLY
SHOWING A PEAK PERIOD OF 6HRS OF THE WORST WINDS AND IT LARGELY
BEING OVERNIGHT BEFORE QUICKLY DIMINISHING...FEEL IMPACT WON/T
BE AS BAD AS PREVIOUS EVENT AND WON/T ISSUE A BLIZZARD WATCH. WINDS
WILL LIKELY BE WORSE OVER ALGER COUNTY...BUT THERE IS MORE
UNCERTAINTY WITH THE VISIBILITY ASPECT OF THE CRITERIA WITH THE
LIMITED SNOWFALL SINCE THE RA/FZRA FROM LAST THURSDAY NIGHT (ALONG
WITH GENERALLY NEW ICE UPSTREAM ON LAKE SUPERIOR AND LIMITED SNOW
COVER). THUS...THINK ANY BLIZZARD CONDITIONS WOULD BE PATCHY AND
WOULD SUPPORT MORE OF A WINTER WX ADVISORY.
STILL LOOKS TO BE A RECORD BREAKING COLD DAY ON THURSDAY...WITH
MODELS KEEPING MUCH OF THE AREA AROUND OR BELOW FREEZING FOR HIGHS.
THAT SEEMS PRETTY REASONABLE WITH THE POCKET OF COLD 850MB TEMPS
(-30C) DIRECTLY OVER THE AREA. THIS IS SIMILAR TO 850MB TEMPS FROM
JANUARY 27TH AND HIGHS THAT DAY WERE IN THE SINGLE DIGITS BELOW
ZERO OVER THE WEST AND AT OR JUST ABOVE FREEZING OVER THE EAST. AS
MENTIONED YESTERDAY...ALL-TIME COLDEST HIGH TEMP RECORDS FOR FEB
27TH ARE GENERALLY IN THE MID SINGLE DIGITS ABOVE ZERO (WITH AT
LEAST 6 DATING BACK BEFORE 1925). WITH COLD AIR IN PLACE AND A HIGH
PRESSURE RIDGE PRODUCING LIGHT WINDS...EXPECT A VERY COLD NIGHT
THURSDAY NIGHT AND WILL CONTINUE TO GO WITH THE LOW END OF GUIDANCE
WHICH PLACES MUCH OF THE AREA BETWEEN -15 AND -30 BELOW. THIS
ALSO HAS THE POTENTIAL FOR BEING RECORD LOWS AT SEVERAL
LOCATIONS...AS LONG AS THE HIGH CLOUDS DON/T COME IN TOO QUICKLY
FROM THE SOUTHWEST.
THE HIGH PRESSURE RIDGE WILL SLIDE EAST ON FRIDAY AS ANOTHER
SHORTWAVE ROUNDING THE EASTERN CANADA TROUGH APPROACHES. A WEAK
INVERTED TROUGH (FROM A LOW IN THE SOUTHERN PLAINS) WILL SLIDE
ACROSS THE AREA ON FRIDAY EVENING AND BRING THE POTENTIAL FOR LIGHT
SNOW. IT DOES APPEAR TO BE OUT AHEAD OF THE MAIN FORCING FROM THE
SHORTWAVE...SO UPPER LEVEL SUPPORT WILL BE LIMITED AND KEEP SNOW
ACCUMULATIONS GENERALLY UNDER AN INCH. MODELS VARY ON HOW MUCH COLD
AIR SPILLS IN BEHIND THIS TROUGH...BUT IT STILL LOOKS LIKE HIGHS ON
SATURDAY WILL BE WELL BELOW NORMAL AND AT OR JUST ABOVE ZERO. THERE
IS ALSO CONCERN FOR LAKE EFFECT SNOW WITH THE COLD AIR PRESENT...BUT
WOULD EXPECT MUCH OF THE LAKE TO BE FROZEN OVER WITH THE COLD AIR
OVER THE PREVIOUS COUPLE OF DAYS AND LIGHT WINDS THURSDAY NIGHT.
THEREFORE...WILL KEEP POPS FOR SATURDAY IN THE SLIGHT CHANCE AND LOW
END CHANCE CATEGORY FOR LOCATIONS NEAR LAKE SUPERIOR. HIGH PRESSURE
BUILDING IN SATURDAY NIGHT AND REMAINING INTO SUNDAY SHOULD LEAD TO
DRY CONDITIONS.
FOR THE FIRST PART OF NEXT WEEK...THE UPPER TROUGH IN EASTERN
CANADA DOES LOOK TO WEAKEN SOME AND BEGIN TO PULL NORTHEAST TOWARDS
THE END OF THE WORK WEEK. OUR CLOSE PROXIMITY TO THIS TROUGH WILL
KEEP THE MAIN STORM TRACK AND WARMER AIR WELL TO THE SOUTH OF THE
AREA...BUT WE COULD STILL SEE WEAK WAVES SLIDING THROUGH. WOULD
EXPECT LAKE SUPERIOR TO BE NEARLY ICE COVERED...SO WILL LIMIT ANY
MENTION OF LAKE EFFECT POPS TO SLIGHT CHANCES AT MOST. AS FOR
TEMPS...SHOULD SEE A SLOW/GRADUAL WARMING TREND THROUGH THE WORK
WEEK...BUT TEMPS WILL STILL BE WELL BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1237 PM EST TUE FEB 25 2014
CMX...GUSTY NW FLOW OF VERY COLD AIR WL RESULT IN LIFR CONDITIONS AT
THIS EXPOSED LOCATION THRU THIS EVNG. WITH SOME DECREASE IN WIND/
BLSN TNGT...EXPECT SOME IMPROVEMENT TO IFR CONDITIONS. AS THE FLOW
BACKS FURTHER TO THE SW ON WED AHEAD OF NEXT DISTURBANCE...THERE WL
LIKELY BE A PERIOD OF VFR CONDITIONS ON WED MRNG.
IWD...A WIND VEERING TO THE NW WL ALLOW SOME LK CLDS/SHSN TO BRING
MVFR CONDITIONS TO THIS LOCATION LATER THIS AFTN/THRU THE EVNG.
OTHERWISE...VFR CONDITONS WL PREDOMINATE.
SAW...MARGINAL MVFR TO VFR CIGS WL PREDOMINATE THRU THIS EVNG WITH A
NW FLOW OF VERY COLD AIR. AS THE FLOW BACKS TO THE W AND SW LATER
TNGT INTO WED...VFR WX WL RETURN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EST TUE FEB 25 2014
NW WINDS UP TO 25-30 KTS LATE TODAY UNDER SHARP PRES GRADIENT
BETWEEN SFC HI OVER THE NCENTRAL PLAINS AND LO PRES IN EASTERN
ONTARIO WILL SLOWLY BACK TO THE SW ON WED AS THE HI MOVES INTO THE
MID MS RIVER VALLEY AND ANOTHER LO PRES SYSTEM DIVES SE INTO NW
ONTARIO. THERE MAY BE SOME GALE FORCE GUSTS TO 35 KTS OVER THE W
HALF OF THE LAKE WHERE FUNNELING OF THIS FLOW RESULTS IN SPEED
ENHANCEMENT. ONCE THE LO SHIFTS TO THE E OF THE LAKE ON WED NIGHT
AS THE PRES GRADIENT TIGHTENS AGAIN E OF HI PRES MOVING INTO THE
NORTHERN PLAINS...N GALES UP TO 35-45 KTS WILL DEVELOP OVER THE
ENTIRE LAKE. THE CLOSER APPROACH OF THE HI CENTER AND WEAKER PRES
GRADIENT WILL CAUSE THE GALES TO DIMINISH W TO E ON THU. ISSUED A
GALE WATCH FOR THE ENTIRE LAKE. EXPECT WINDS UNDER 25 KTS THE REST
OF THE FORECAST PERIOD WITH A RELATIVELY WEAK PRES GRADIENT
DOMINATING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY FROM MIDNIGHT EST /11 PM CST/ TONIGHT TO 10
AM EST /9 AM CST/ WEDNESDAY FOR MIZ001>005-009>011-084.
LAKE SUPERIOR...
GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY AFTERNOON
FOR LSZ243>245-248>251-264>267.
GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING FOR
LSZ162-240>242-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
400 PM EST TUE FEB 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 PM EST TUE FEB 25 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A FAMILIAR PATTERN
FEATURING A DEEP UPR TROF OVER ERN NAMERICA DOWNSTREAM OF A RDG
ALONG THE W COAST. SHRTWV EMBEDDED IN THE NW FLOW IS STREAKING SEWD
THRU ONTARIO JUST N OF LK SUP. COLD FNT ASSOCIATED WITH THIS
DISTURBANCE HAS PASSED THRU THE CWA...AND H85 TEMPS AS LO AS -25C TO
-28C ARE PUSHING INTO UPR MI IN THE LLVL W FLOW. ALTHOUGH THERE IS A
GOOD DEAL OF ICE ON LK SUP...AREAS OF OPEN WATER OVER THE FAR WRN LK
AND OVER THE SCENTRAL E OF THE KEWEENAW HAVE ALLOWED A GOOD DEAL OF
LK CLD/SOME -SHSN TO FORM IN THE LLVL CAD. THE LK CLDS/SHSN APPEAR
TO BE MOST WDSPRD OVER THE NE HALF OF THE AREA CLOSER TO THE SHRTWV
PASSING THRU ONTARIO/ACCOMANPANYING DYNAMIC SUPPORT AND DEEPER MSTR.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LK EFFECT CLD/SHSN
TRENDS AND TEMPS/NEED FOR WIND CHILL HEADLINES.
LATE THIS AFTN/TNGT...AS THE H925 FLOW VEERS MORE TO THE NW THRU 00Z
IN THE WAKE OF SHRTWV PASSING BY TO THE N...EXPECT LK EFFECT
CLDS/SHSN TO SPREAD FARTHER TO THE S AND INLAND IN THE PRESENCE OF
LENGTHENING DAYTIME HEATING DESPITE DNVA/DEEP LYR QVECTOR DVGC IN
THE WAKE OF THE SHRTWV PASSAGE. H85 THERMAL TROF WITH TEMPS DOWN TO
-28/-29C IS FCST TO SHIFT THRU THE CWA BTWN 06Z-12Z AS THE LLVL FLOW
BACKS TO THE W BTWN SFC HI PRES SINKING TOWARD THE MID MS RIVER
VALLEY AND NEXT VIGOROUS SHRTWV DROPPING SEWD THRU SCENTRAL CANADA.
WITH A PERIOD OF LARGER SCALE QVECTOR DVGC...EXPECT CLRG OVER THE
INTERIOR...ALLOWING SFC TEMPS TO FALL WELL BLO ZERO AND INTO THE
TEENS BLO ZERO AT SOME PLACES UNDER DRY AIRMASS WITH PWAT UNDER 0.10
INCH. ALTHOUGH THERE ARE QUESTIONS AS TO WHETHER SFC WINDS WL
CONSISTENTLY SATISFY THE 10 MPH SPEED THRESHOLD FOR A WIND CHILL
ADVY...PLAN TO ISSUE AN ADVY FOR THE COLDER NW HALF OF THE CWA WITH
FAIRLY SHARP PRES GRADIENT/H925 WINDS IN THE 20-30KT RANGE UNDER H85
THERMAL TROF ENHANCING MIXING. LK EFFECT CLDS/-SHSN WL SHIFT FM THE
NW WIND SN BELTS BACK INTO AREAS IMPACTED BY W WINDS LATE TNGT.
ABSENCE OF DGZ WITHIN VERY COLD AIRMASS AND ICE COVER WL LIMIT SN
ACCUMS.
WED...AREA OF DEEP LYR QVECTOR CNVGC IN ADVANCE OF SHRTWV/SFC LO
DIGGING SEWD THRU NW ONTARIO WL OVERSPREAD UPR MI NW-SE BY EARLY
AFTN. IN THE ABSENCE OF ANY SGNFT MSTR INFLOW...SUSPECT DRYNESS OF
ANTECEDENT AIRMASS WL BE A SGNFT IMPEDIMENT TO OUTBRREAK OF PCPN. AS
THE FLOW SHIFTS TO THE SW...THERE IS POTENTIAL FOR SOME LK
MOISTENING/ENHANCEMENT OFF OF LK MI. BUT EXTENSIVE/GROWING ICE COVER
OVER THE N HALF OF LK MI WL TEND TO MITIGATE THIS IMPACT. TENDED
TOWARD THE HIER CHC/LIKELY POPS OVER THE NE HALF OF THE CWA TOWARD
SHARPER ISENTROPIC ASCENT ON THE 270K SFC /NEAR H7/ AND ALSO LATE IN
THE DAY OVER THE W WITH EXPECTED ARRIVAL OF ENHANCED LLVL CNVGC
ASSOCIATED WITH COLD FNT ATTENDANT TO CLIPPER LO REACHING NE LK SUP
BY 00Z THU.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 518 AM EST TUE FEB 25 2014
VERY COLD...LIGHT-MODERATE SNOW...AND VERY STRONG WINDS WILL BE THE
MAIN STORIES FOR THIS LONG TERM SECTION.
MULTIPLE SHORTWAVES SLIDING ACROSS THE AREA IN THE FAST 500MB W-NW
FLOW WILL RESULT IN A MOSTLY CLOUDY SKY FOR MUCH OF THE PERIOD...AND
GENERALLY LIGHT SNOW. SNOW WILL VARY SIGNIFICANTLY MAINLY DUE THE
THE NEARLY FROZEN...OR QUICKLY RE-FREEZING LAKE SUPERIOR.
WILL START OFF WEDNESDAY MORNING UNDER NW FLOW ALOFT...AND A SLIGHT
RIDGE AT THE SFC WITH DIMINISHING CHANCES OF LES. PLENTY OF CLOUDS
WILL REMAIN AS THE NEXT SFC LOW/SHORTWAVE NEAR FROM THE NW. THE
DEEPENING SFC LOW OVER CENTRAL ONTARIO AT 18Z WILL SINK ACROSS THE
KEWEENAW AND E LAKE SUPERIOR BY 00Z THURSDAY. INCREASING SW WINDS OF
10-20KTS AHEAD OF THE LOW WILL QUICKLY SHIFT BACK TO THE NW LATE
WEDNESDAY AFTERNOON INTO THE EARLY EVENING HOURS. THE MAIN 500MB LOW
WILL BE ABLE TO SINK TO NE LAKE SUPERIOR BY 06Z THURSDAY...WITH VERY
LOW 850MB TEMPS OF -30 TO -36C STRETCHING FROM W UPPER MI THROUGH
MUCH OF LAKE HURON. VERY STRONG WINDS WILL ALLOW FOR SIGNIFICANT
BLOWING AND DRIFTING SNOW ACROSS THE KEWEENAW PENINSULA BRIEFLY ON
SW WINDS EARLY WEDNESDAY AFTERNOON...AND THEN ON NW WINDS WEDNESDAY
NIGHT INTO THURSDAY MORNING WITH IMPRESSIVE MOMENTUM TRANSFER VALUES
OF NEAR 33-40KT. WITH THESE KIND OF WINDS WE COULD SEE NEAR BLIZZARD
CONDITIONS...DESPITE NEW SNOW OF GENERALLY 2IN OR LESS OVER THE
KEWEENAW PENINSULA AND E OF MARQUETTE ALONG M-28 THROUGH
MUNISING...AND THEN E TO GRAND MARAIS. LOW WIND CHILLS OF 20 TO NEAR
40 BELOW ZERO WILL BE POSSIBLE AS SFC TEMPS FALL INTO THE TEENS
BELOW ZERO OVER THE W HALF OF UPPER MI.
BITTERLY COLD CONDITIONS WILL CONTINUE THROUGH SUNDAY...WITH RECORD
BREAKING TEMPERATURES POSSIBLE THURSDAY THROUGH FRIDAY MORNING. AS A
RESULT...WILL KEEP THE MAINLY CHANCE POPS OR LESS BEYOND
THURSDAY...DUE TO THE UNKNOWN ICE BREAKAGE FROM THE STRONG WINDS
WEDNESDAY/THURSDAY...AND RE-FREEZING THAT COULD BE POSSIBLE IN THIS
VERY COLD AIRMASS. COLDEST MORNING LOOKS TO BE THURSDAY NIGHT/FRIDAY
MORNING...WITH TEMPS BOTTOMING OUT NEAR 25 BELOW OVER THE INTERIOR W
HALF. HOWEVER...WITH HIGH PRESSURE OVERHEAD...AND WINDS GENERALLY
5KTS OR LESS WIND CHILLS WILL STILL BE COLD BUT NOT QUITE AS DRASTIC.
THERE IS STILL ENOUGH VARIANCE IN THE MODELS FROM THE WEEKEND ON TO
RESULT IN A MORE MEDIUM TO LOWER CONFIDENCE IN THE FCST. WAS A
LITTLE CONCERNED WITH THE 24/18Z RUN OF THE GFS CAME IN WITH A
1020MB SFC LOW OVER THE E HALF OF UPPER MI AT 06Z SATURDAY. THE
25/00Z GFS SHOVED IT FARTHER TO THE S MUCH QUICKER. THEN THE LATEST
ECMWF CAME IN WITH A SOLUTION CLOSER TO THE ORIGINAL/SLOWER 24/18Z
GFS...WITH THE ORIGINAL PLAN WAS TO HAVE THE STRONG SFC HIGH SURGING
IN FROM S CANADA AND THE CENTRAL PLAINS. HAVE KEPT WITH A MODEL
BLEND IN THE ONGOING FCST...BUT AS NOTED CONFIDENCE IS
DIMINISHING...WITH SIGNIFICANT IMPLICATIONS TO SKY
COVER/TEMPS/WINDS/WIND CHILLS/AND WX. AT 12Z 850MB TEMPS OFF THE
ECMWF WENT FROM A CWA AVERAGE -30 TO -24C...WITH THE COLDEST AIR NOW
LIKELY STAYING N ACROSS ONTARIO. WILL KEEP THE MENTION OF COLD
TEMPS/LOW WIND CHILLS IN THE HWO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1237 PM EST TUE FEB 25 2014
CMX...GUSTY NW FLOW OF VERY COLD AIR WL RESULT IN LIFR CONDITIONS AT
THIS EXPOSED LOCATION THRU THIS EVNG. WITH SOME DECREASE IN WIND/
BLSN TNGT...EXPECT SOME IMPROVEMENT TO IFR CONDITIONS. AS THE FLOW
BACKS FURTHER TO THE SW ON WED AHEAD OF NEXT DISTURBANCE...THERE WL
LIKELY BE A PERIOD OF VFR CONDITIONS ON WED MRNG.
IWD...A WIND VEERING TO THE NW WL ALLOW SOME LK CLDS/SHSN TO BRING
MVFR CONDITIONS TO THIS LOCATION LATER THIS AFTN/THRU THE EVNG.
OTHERWISE...VFR CONDITONS WL PREDOMINATE.
SAW...MARGINAL MVFR TO VFR CIGS WL PREDOMINATE THRU THIS EVNG WITH A
NW FLOW OF VERY COLD AIR. AS THE FLOW BACKS TO THE W AND SW LATER
TNGT INTO WED...VFR WX WL RETURN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 AM EST TUE FEB 25 2014
A FEW POCKETS OF FREEZING SPRAY WILL BE POSSIBLE WEDNESDAY INTO
THURSDAY MORNING ACROSS THE OPEN WATERS OF WESTERN LAKE SUPERIOR. A
FEW SOUTHWESTERLY GALE FORCE GUSTS TO 35 KNOTS ARE POSSIBLE AROUND
MID DAY WEDNESDAY ACROSS THE WEST HALF OF LAKE SUPERIOR. BEHIND A
LOW PRESSURE SYSTEM WEDNESDAY NIGHT THROUGH THURSDAY
MORNING...NORTHWESTERLY GALES TO 35 TO 40 KNOTS ARE EXPECTED OVER
MUCH OF LAKE SUPERIOR. A GALE WATCH MAY BE NEEDED FOR WEDNESDAY
NIGHT AND THURSDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY FROM MIDNIGHT EST /11 PM CST/ TONIGHT TO 10
AM EST /9 AM CST/ WEDNESDAY FOR MIZ001>005-009>011-084.
LAKE SUPERIOR...
GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY AFTERNOON
FOR LSZ243>245-248>251-264>267.
GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING FOR
LSZ162-240>242-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1134 AM CST TUE FEB 25 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 259 AM CST TUE FEB 25 2014
CLOUDS AND OCCASIONAL FLURRIES ARE LINGERING IN THE AREA. SUBJECTIVE
00Z UPPER AIR ANALYSIS INDICATES UPPER-LEVEL SHORTWAVE TROUGH NEAR
THE SD/ND BORDER...WITH 500MB HEIGHT FALLS UP TO 90M AHEAD OF IT IN
EASTERN SD. 08Z WATER VAPOR AND RAP 1.5 PVU PRESSURE INDICATE
STRONG UPPER-LEVEL TROUGH DIGGING THROUGH IA THIS MORNING...WITH
SECONDARY SHORTWAVE UPSTREAM IN NORTHERN MT. STRONGEST UPPER-LEVEL
JET EXTENDED FROM MT THROUGH WESTERN SD INTO EASTERN NEB/IA AND
EASTWARD ACROSS THE MID-ATLANTIC. MUCH COLDER AIR WAS FILTERING
INTO THE PLAINS IN WAKE OF THE TROUGH...WITH 850MB TEMPERATURES -20C
OR COLDER IN ND/MT AND UPPER TEENS BELOW ZERO SPILLING INTO SD.
MAIN FORECAST CONCERN IS POTENTIAL FOR LIGHT SNOW TO CLIP THE
SOUTHWEST CWA TODAY...THEN ONE MORE DAY OF MODERATE TEMPERATURES
BEFORE THE COLD AIR PLUNGES INTO THE PLAINS. WEAK LIFT IN THE
DENDRITIC ZONE WILL EXIT THE AREA BY THIS MORNING...AND FLURRIES
SHOULD END FOR A TIME. SECOND...WEAKER SHORTWAVE WILL SLIDE THROUGH
THE NORTHERN ROCKIES TOWARD WESTERN/CENTRAL NEB TODAY...WITH WEAK
FRONTOGENETIC BAND AROUND 700-650MB SETTING UP FROM WESTERN TO SOUTH
CENTRAL NEB THIS AFTERNOON. SHOULD SEE SNOW WITH THAT BAND...BUT
EASTERN EXTENT IS IN QUESTION AS BETTER SUPPORT REMAINS WEST OF THE
AREA...AND DRIER LOW-LEVEL AIR BELOW THE MORE SATURATED MID-LEVELS
MAY HINDER MEASURABLE SNOW. HAVE CONTINUED TO INDICATE SLIGHT CHANCE
OF SNOW IN SOUTHEAST NEB THIS AFTERNOON...TAPERING AWAY BY THIS
EVENING.
WESTERLY WINDS RETURN TO THE AREA ON WEDNESDAY. WHILE SNOW ON THE
GROUND WILL HINDER TEMPERATURES IN THE NORTHERN CWA...THE COUPLE OF
TENTHS THAT FELL ELSEWHERE ARE NOT LIKELY TO COUNTERACT THE
FAVORABLE MIXING WINDS. HAVE KEPT TEMPS ABOVE GUIDANCE IN THE 30S
ACROSS MOST OF THE AREA...AS THE LAST DAY THAT COULD RISE ABOVE
FREEZING FOR QUITE SOME TIME. REINFORCING COLD AIR ARRIVES ON
WEDNESDAY NIGHT/THURSDAY AS A COLD AND DRY HIGH PRESSURE SLIDES OUT
OF THE DAKOTAS/MN INTO WESTERN IA. MID-LEVEL WARM AIR ADVECTION IS
PROGGED TO DEVELOP ON THE WESTERN SIDE OF THE HIGH ON THURSDAY
NIGHT...BUT GIVEN DRY AIR FEEDING IN FROM THE EAST...BELIEVE PRECIP
WILL BE HELD AT BAY THROUGH 12Z FRIDAY. MODELS HAVE TRENDED IN THAT
DIRECTION AS WELL...WITH ALL SOLUTIONS BUT THE NAM NOW DRY FOR
THURSDAY NIGHT. HAVE REMOVED POPS ACROSS THE AREA.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 259 AM CST TUE FEB 25 2014
ALTHOUGH THERE IS A BRIEF ATTEMPT AT MODERATION ON FRIDAY...PATTERN
TURNS COLDER THROUGH THE WEEKEND/MONDAY...WITH MUCH BELOW
NORMAL TEMPERATURES AND CHANCES OF LIGHT SNOW PERSISTING.
GOOD AGREEMENT BETWEEN 00Z GFS/ECMWF IN A DECENT H7 LOW/TROUGH
MOVING ALONG KS BORDER FRIDAY BRINGING MODEST SNOW CHANCES TO MUCH
OF THE FA...ESPECIALLY CNTRL/SRN ZONES. AFTER THAT THE COLD AIR IS
REINFORCED OVER THE NRN/CENTRAL PLAINS AS SEVERAL LOBES PIVOT AROUND
HUDSON BAY LOW SENDING COLD HIGH PRESSURE SOUTHWARD. MEANWHILE...
THE MID LEVEL FLOW OVER THE PLAINS REMAINS MORE WRLY AND EVEN
SWRLY AT TIMES. THUS PERIODS OF SNOW CHANCES WILL
PERSIST...ALTHOUGH NO MAJOR SYSTEMS WERE CURRENTLY SUGGESTED FOR
FA BY 00Z MODELS. BASED ON 00Z RUNS OF GFS/ECMWF IT DOES APPEAR
SOMEWHAT OF A LULL POSSIBLE FRIDAY NIGHT OVER MUCH OF THE
AREA...SATURDAY ACROSS THE SOUTH AND THEN MOST OF THE REGION BY
MONDAY. PRECIPITATION MENTION DURING THOSE TIMES WAS KEPT MOSTLY
IN THE SLIGHT CHANCE CATEGORY...ALTHOUGH WITH MID LEVEL
TEMPERATURES FAVORABLE FOR ICE CRYSTAL GENERATION IT WOULD NOT
TAKE MUCH TO GENERATE AREAS OF LIGHT SNOW ANY OF THOSE PERIODS IF
MOISTURE IS PRESENT. WITH H85 TEMPERATURES OF -15 TO -25 FORECAST
TO SAG SWD THROUGH FA SAT/SUN...MAX TEMPERATURES MAY REMAIN IN
SINGLE DIGITS MANY AREAS SATURDAY AND POSSIBLY EVEN SUNDAY NRN
ZONES WITH MEX/ECE GUIDANCE POSSIBLY INFLUENCED BY CLIMO WITH
NORMAL HIGHS NOW APPROACHING OR EXCEEDING 40 DEGREES F. TRIMMED
BACK HIGHS A BIT SATURDAY/SUNDAY. LEFT LOWS MOSTLY ALONE FOR
NOW...SINGLE DIGITS EITHER SIDE OF ZERO F...AS CLOUD INFLUENCES
ENOUGH OF A THREAT WITH THE WEST OR POSSIBLY SW MID LEVEL FLOW
RIDING OVER COLD LOW LEVEL FLOW.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1130 AM CST TUE FEB 25 2014
A FEW MVFR CIGS AND VISIBILITIES ARE POSSIBLE AT KLNK INITIALLY AS
A BAND OF SNOW SLIDES SOUTH ACROSS THE TAF SITE. OTHERWISE...KOFK
AND KOMA SHOULD REMAIN VFR THROUGHOUT THE TAF CYCLE. HIGH PRESSURE
WILL BUILD SOUTHEAST ACROSS THE AREA OVERNIGHT. NORTHWEST SFC
WINDS WILL DIMINISH AND SKIES WILL CLEAR. SFC WINDS WILL TURN TO
THE SOUTHWEST LATE WEDNESDAY MORNING AND BECOME GUSTY TO NEAR 20
TO 25 KTS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MAYES
LONG TERM...CHERMOK
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1220 PM EST TUE FEB 25 2014
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT OFF THE VIRGINIA COAST TODAY. A COLD
FRONT WILL MOVE ACROSS THE AREA TONIGHT INTO WEDNESDAY...BRINGING
SOME SHOWERS. COLD HIGH PRESSURE WILL BRING WELL BELOW NORMAL
TEMPERATURES FROM WEDNESDAY INTO THE WEEKEND. A SIGNIFICANT WARM-
UP IS POSSIBLE FOR EARLY NEXT WEEK...ALONG WITH INCREASING RAIN
CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 PM TUESDAY...TEMPERATURES HAVE JUMPED UP MUCH HIGHER
THAN EXPECTED ALONG THE COAST AS IT APPEARS THE DEVELOPING WARM
FRONT HAS PUSHED ASHORE. HAVE ADJUSTED FORECAST ACCORDINGLY. BASED
ON LATEST GUIDANCE AND TRENDS HAVE ALSO REMOVED SLIGHT CHANCE POPS
FOR LATER THIS AFTERNOON. ANTICIPATE MINIMAL TWEAKS TO THE
OVERNIGHT FORECAST WITH THE MID-AFTERNOON UPDATE. PREVIOUS
DISCUSSION FOLLOWS:
A RATHER COMPLEX 24 HOURS IS AHEAD OF US WEATHER WISE. SURFACE HIGH
PRESSURE IS MOVING OFF THE DELMARVA COAST THIS MORNING...WITH
VEERING WINDS ALREADY OBSERVED OFFSHORE AT THE FRYING PAN SHOALS
BUOY. WARM FRONTOGENESIS IS OCCURRING JUST OFFSHORE AS THE AIRMASS
QUICKLY MODIFIES OVER RELATIVELY WARM WATER TEMPS. UP AT 300 MB
THERE ARE TWO BRANCHES OF THE JET DISCERNIBLE: THE POLAR JET LIES
ACROSS THE CENTRAL APPALACHIANS AND MID-ATLANTIC REGION...WHILE
THE SUBTROPICAL JET COMES OUT OF NORTHERN MEXICO AND CROSSES THE
GULF COAST. CIRRUS CLOUDS COVERING THE CAROLINAS EARLY THIS
MORNING ARE DUE TO A WEAK DISTURBANCE IN THE SUBTROPICAL JET OVER
NORTHERN FLORIDA THAT SHOULD BE OFFSHORE IN THE NEXT FEW HOURS.
A SECOND SUBTROPICAL JET DISTURBANCE WILL MOVE THROUGH THE
SOUTHERN MS VALLEY THIS AFTERNOON. OUR OFFSHORE WARM FRONT WILL BE
DRAWN INLAND TODAY BY SURFACE PRESSURE FALLS OCCURRING AHEAD OF
THIS DISTURBANCE. WITH SEVERAL HOURS OF MOSTLY SUNNY SKIES
EXPECTED THIS MORNING THIS SHOULD ALLOW TEMPERATURES TO RISE INTO
THE 60S AND LOWER 70S BY EARLY AFTERNOON...WARMEST SOUTH OF
FLORENCE AND CONWAY. DURING THE MID AND LATE AFTERNOON MOISTURE
WILL INCREASE FROM THE WEST BETWEEN 850 AND 700 MB. COUPLED WITH
MODEST ISENTROPIC LIFT ALONG THE 295K THETA SURFACE THIS COULD
PRODUCE ISOLATED SHOWERS. POPS ARE LIMITED TO 20 PERCENT AND
MAINLY FOR COASTAL LOCATIONS.
THIS EVENING THE BEST PRESSURE FALLS WILL SHIFT OFFSHORE AS A MUCH
STRONGER POLAR JET DISTURBANCE APPROACHES FROM THE NORTHWEST. THIS
WILL TAKE THE WARM FRONT ACROSS EAST-CENTRAL NORTH CAROLINA AND
PUSH IT SOUTHWARD AS A COLD FRONT BEHIND A DEEPENING SURFACE LOW
OFFSHORE...WITH COOLER AIR SURGING SOUTHWARD TO THE SANTEE RIVER
OVERNIGHT. ISENTROPIC FIELDS INDICATE LITTLE POTENTIAL FOR
PRECIPITATION DURING THE EVENING HOURS...HOWEVER INCREASING LIFT
AGAIN ALONG THE 295K THETA SURFACE VERY LATE TONIGHT SHOULD
PRODUCE AN AREA OF SHOWERS ACROSS SOUTH CAROLINA SPREADING TO THE
NC/SC COAST BY DAYBREAK.
BOTH THE 06Z GFS AND NAM LOOK WARMER WITH DAYTIME TEMPS TODAY THAN
THEIR 00Z COUNTERPARTS DID. THE INTER MODEL DIFFERENCES BETWEEN THE
NEW GFS AND NAM HAVE DECREASED RELATIVE TO THE LARGER DIFFERENCES
DISPLAYED ON THE 00Z RUNS WHERE THE GFS APPEARED MUCH TOO COLD.
BASED ON THIS TREND AND THE LATEST FEW RUNS OF THE RUC I HAVE
RAISED HIGH TEMP FORECASTS TODAY...EXPANDING THE AREA OF LOWER 70S
IN THE KINGSTREE-GEORGETOWN-CONWAY AREA THIS AFTERNOON. UPPER 60S
ARE FORECAST FOR MOST AREAS EAST OF I-95 AND SOUTH OF
ELIZABETHTOWN. LOWER TO MID 60S ARE STILL EXPECTED NORTH OF
FLORENCE...DILLON... ELIZABETHTOWN AND WATHA.
FOR TONIGHT: THE 00Z NAM MODEL APPEARS TO HAVE A BETTER HANDLE ON
THE DEVELOPMENT AND MOVEMENT OF THE WARM FRONT TODAY AND THE
OFFSHORE LOW TONIGHT. THE NAM`S MAX/MIN TEMPERATURES ALSO APPEAR
BETTER THAN THE GFS... ALTHOUGH IT IS CURIOUS WHY BOTH THE NAM AND
GFS MOS PRODUCTS ARE SO COOL WITH HIGHS TODAY GIVEN RAW MODELS
RUNNING SEVERAL DEGREES WARMER. MY FORECAST HIGHS ARE WARMER THAN
NAM OR GFS MOS... PARTICULARLY NEAR THE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...COLD FRONT WILL BE DRAPED ALONG OR JUST
SOUTH AND OFFSHORE OF THE CWA AT THE START OF THE PERIOD. MOST
DIFFICULT PART OF THE FORECAST WILL BE HOW THE INTERACTION OF THIS
BOUNDARY AND SOME ENHANCED MOISTURE RETURN WILL AFFECT THE CWA
WITH RAINFALL ON WEDNESDAY. THE COLD FRONT WILL MOVE ONLY VERY
SLOWLY SOUTHWARD AS THE REGION REMAINS BENEATH THE BASE OF THE
EASTERN TROUGH...THUS FLOW BECOMES NEARLY BOUNDARY-PARALLEL ON
WEDNESDAY. AS THIS FRONT STALLS NEAR THE AREA...MOISTURE INCREASES
ALONG IT...AND SOME WEAK LIFT DUE TO MID-LEVEL IMPULSES WILL TRY
TO SPAWN SOME POST-FRONTAL RAINFALL ACROSS THE CWA. NAM/GFS ARE
WETTER AND IN BETTER AGREEMENT THAN THE ECMWF...SO WILL LEAN MORE
ON THESE MODELS FOR PRECIP POTENTIAL ON WEDNESDAY. THE BEST
CHANCES FOR PRECIP WILL BE ALONG THE SE THIRD OF THE CWA...CLOSEST
TO THE BOUNDARY AND WHERE ISENTROPIC LIFT FROM 290-300K IS
FOCUSED...BUT SREF PROBS SUGGEST AT LEAST 60% 12-HR CHANCE OF 0.01
QPF ACROSS THE ENTIRE CWA. INHERITED POP HAS LIKELY ACROSS THE
EAST WITH HIGH-CHC WEST...AND WILL BUMP THESE NUMBERS BUT KEEP
WITHIN THE SAME CATEGORIES FOR WEDNESDAY. HIGHEST CHANCES WILL BE
WED MORNING INTO THE AFTN...DROPPING FROM NW TO SE THROUGH THE EVE
AS THE FRONT DRIFTS SLOWLY AWAY AND THE MID-LEVEL IMPULSE PUSHES
EASTWARD.
WHILE THE WEAK CAA...CLOUDS...AND RAIN WILL KEEP TEMPS WEDNESDAY
WELL BELOW NORMAL...AROUND 50 FOR HIGHS...SKY CONDITIONS WILL
CLEAR RAPIDLY WED NIGHT. AT THE SAME TIME...HIGH PRESSURE FROM THE
WEST WILL CONTINUE TO RIDGE TOWARDS THE AREA. A RELATIVELY WEAK
PRESSURE GRADIENT WED NIGHT WILL LEAVE ONLY LIGHT NORTH WINDS
AHEAD OF THIS HIGH PRESSURE...WHICH COMBINED WITH CLEARING SKY
CONDITIONS WILL CREATE A COLD NIGHT INTO THU MORNING...AND EXPECT
NEARLY THE ENTIRE AREA TO FALL BELOW FREEZING...WITH MID 20S
POSSIBLE IN THE TYPICALLY COLDER SPOTS.
SUBTLE AIR MASS MODIFICATION OCCURS THURSDAY THANKS TO SURFACE
HIGH PRESSURE RIDGE AXIS BULGING UP TOWARDS THE MID-ATLANTIC. THIS
WILL BE SOMEWHAT OFFSET BY CONTINUED LOW THICKNESSES SOUTH OF THE
COLD 5H VORTEX ACROSS NEW ENGLAND...AND THUS WHILE THURSDAY WILL
BE WARMER THAN WEDNESDAY...TEMPS WILL STAY BELOW NORMAL...RISING
ONLY INTO THE MID 50S...WITH A FEW UPPER 50S POSSIBLE NEAR THE
SOUTH SANTEE RIVER. A RENEWED SURGE OF COLD AIR IS NOW PROGGED FOR
THURSDAY NIGHT AS A SECONDARY DRY COLD FRONT CROSSES AHEAD OF
ARCTIC HIGH PRESSURE DROPPING OUT OF CANADA. THIS WILL CREATE A
COLD AND BREEZY NIGHT THURSDAY NIGHT...AS LOW DROP ONCE AGAIN TO
FREEZING OR BELOW...WITH EVEN COLDER APPARENT TEMPS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 AM TUESDAY...COLD TO START THE EXTENDED AS ARCTIC HIGH
PRESSURE DEVELOPS INTO A WEDGE ALONG THE EAST COAST. THIS WILL
CREATE COOL NE WINDS INTO THE FIRST HALF OF THE WKND...WITH TEMPS
REMAINING SOLIDLY BELOW CLIMO FOR THE END OF FEBRUARY. WHILE
GUIDANCE HAS BEEN ADVERTISING A SOUTHERN STREAM LOW FOR SEVERAL
DAYS NOW...THIS FEATURE HAS BECOME LESS INTENSE...AND NOW THE
SURFACE REFLECTION HAS BASICALLY DISAPPEARED THANKS TO WEAKER MID-
LEVEL FORCING AND BAROCLINIC INSTABILITY. STILL...THERE IS AT
LEAST DECENT POTENTIAL FOR SOME SHOWERS ON SATURDAY BENEATH THE
MID-LEVEL IMPULSE...BUT OVERALL QPF LOOKS LIMITED.
ADDITIONALLY...WITH THE COOL AIR IN PLACE WITHIN THE WEDGE...THIS
OVERRUNNING SCENARIO MAY PROMOTE A MIXED P-TYPE EVENT...ESPECIALLY
WELL INLAND. TEMPS WILL BE MARGINAL AT-BEST FOR ANYTHING OTHER
THAN THAT LIQUID...AND WILL KEEP -RW AS WX TYPE FOR NOW...BUT
THERE IS AT LEAST A SMALL CHANCE FOR SOME FROZEN PRECIP FRIDAY
NIGHT/SAT AM.
GUIDANCE DIFFERS CONSIDERABLY INTO THE BEGINNING OF NEXT WEEK. GFS
BREAKS DOWN THE WEDGE QUICKLY AS MID-LEVEL RIDGING
DEVELOPS...CENTERED OFF THE FLORIDA COAST. ECMWF SHOWS A SIMILAR
PROCESS BUT WITH A SLOWER TEMPORAL EVOLUTION. THIS CAUSES 15+
DEGREE TEMP DIFFERENCES IN THE FORECASTS FOR NEXT WEEK. A QUICK
GLANCE AT SOME OF THE ENSEMBLES SUGGESTS THAT THE OP-GFS IS WELL
TOO WARM AS IT IS ON THE HIGH SIDE OF ALL ITS ENSEMBLE
THICKNESSES. STILL...THE UPPER PATTERN FAVORS WEDGE BREAKDOWN AND
AT LEAST A MARGINAL WARMUP SUN/MON...SO WILL BUMP TEMPS TOWARDS
AND ABOVE CLIMO FOR EARLY NEXT WEEK. A MORE IMPRESSIVE LOW
PRESSURE SYSTEM MAY APPROACH MONDAY...AND WILL KEEP INHERITED CHC
POP ATTM.
&&
.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
AS OF 18Z...VISIBLE SATELLITE IMAGERY SHOWS LOW AND MID LEVEL CLOUDS
APPROACHING FROM THE WEST ASSOCIATED WITH A NARROW BAND OF
ISENTROPIC LIFT. WILL MENTION VCSH FOR ALL TERMS AS RADAR SHOWS SOME
VERY LIGHT RETURNS OFF TO OUR WEST...BUT ANY -RA THAT DOES DEVELOP
SHOULD HAVE LIMITED AVIATION IMPACTS. EXPECT VFR THROUGH THE AFTN
HOURS WITH WEST-SOUTHWEST WINDS AROUND 10 KTS. THE PATTERN WILL
QUICKLY CHANGE THIS EVENING AS LOW PRESSURE DEVELOPS OFF THE NC/VA
COAST. THIS LOW WILL PUSH A COLD FRONT THROUGH OUR CWA TONIGHT AS
SURFACE WINDS SHIFT FROM WEST TO NORTHEAST. THE LATEST NAM SOUNDINGS
SUPPORT AT LEAST MVFR CIGS DEVELOPING ACROSS MUCH OF THE AREA BY
DAYBREAK. CIGS AT THE COASTAL TERMS MAY DROP BELOW 1KFT...BUT SINCE
CONFIDENCE IS LOW ATTM...WILL JUST MENTION SCT IFR STRATUS WITH MVFR
CIGS. BY 12Z...RAIN WILL BECOME MORE WIDESPREAD WITH ANOTHER ROUND
OF MOIST ISENTROPIC LIFT AS THE FRONT LINGERS TO OUR SOUTH.
EXTENDED OUTLOOK...VFR THURSDAY AND FRIDAY. CHANCE OF RAIN/MVFR ON
SATURDAY. VFR SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 PM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
SEASONS WILL CHANGE AT LEAST TWICE ACROSS THE COASTAL WATERS TODAY
AS A FRONT WAVERS ACROSS THE AREA. A WARM FRONT DEVELOPING ACROSS
THE COASTAL WATERS SHOULD PUSH INLAND LATER THIS MORNING...WITH
EAST WINDS VEERING TO THE SOUTH. WINDS SPEEDS WILL INCREASE TO
10-15 KNOTS AS DIRECTIONS CONTINUE TO VEER SOUTHWESTERLY DURING
THE AFTERNOON. THIS VEERING SHOULD BE IN RESPONSE TO FALLING
PRESSURES AS LOW PRESSURE DEVELOPS ALONG THE COAST TODAY...THEN
OFFSHORE THIS EVENING. CLOCKWISE WINDS BLOWING AROUND THIS LOW
SHOULD PUSH THE WARM FRONT BACK SOUTHWARD AS A COLD FRONT THIS
EVENING. THE FRONT MAY PRESS ALL THE WAY TO THE SANTEE
RIVER...WITH NORTH TO NORTHEAST WINDS STRONGEST ACROSS THE NC
WATERS CLOSEST TO THE POSITION OF THE LOW.
SEAS CURRENTLY RANGE FROM 2-3 FEET WITH DOMINANT PERIODS AROUND 9
SECONDS IN SOUTHEAST SWELL. A SMALL SHORT PERIOD CHOP WILL DEVELOP
IN THE SOUTH-SOUTHWEST WIND BEHIND THE WARM FRONT...WITH CONFUSED
SEAS FOR A PERIOD THIS EVENING AS WINDS SHIFT TO THE NORTH AS THE
FRONT IS PUSHED ACROSS AGAIN. TOTAL SEA HEIGHTS WILL PROBABLY NOT
EXCEED 4 FEET AT ANY POINT THROUGH TONIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...COLD FRONT MOVING OFFSHORE AT THE START OF
THE PERIOD WILL DRIFT SOUTH OF THE AREA INTO THURSDAY...WITH
NORTHERLY WINDS INCREASING TO 15-20 KTS...AND REMAINING AT THESE
SPEEDS INTO THURSDAY MORNING. THESE WINDS WILL EASE AND BACK TO
THE SW ON THURSDAY AS A RIDGE OF HIGH PRESSURE BRIEFLY ENVELOPS
THE AREA...BUT WILL QUICKLY RETURN TO THE NORTH AT 15-20 KTS AT
THE END OF THE PERIOD AS A SECOND COLD SURGE MOVES ACROSS THE
WATERS. EVEN THOUGH WINDS WILL BE GUSTY ON WEDNESDAY...THE
NORTHERLY COMPONENT WILL INHIBIT SUBSTANTIAL WAVE GROWTH...AND
THUS SEAS WILL RISE TO PEAK AT 3-5 FT WEDNESDAY EVE...BEFORE
FALLING BACK TO 1-3 FT DURING THURSDAY. RENEWED AMPLIFICATION IS
EXPECTED AT THE END OF THE SHORT TERM AS THE WINDS ONCE AGAIN RISE
FROM THE NORTH...WITH WAVE HEIGHTS BECOMING 2-4 FT BY FRIDAY
MORNING.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 300 AM TUESDAY...DEVELOPING WEDGE OF HIGH PRESSURE EXTENDING
DOWN THE EAST COAST WILL CREATE A PROLONGED PERIOD OF NE WINDS
OVER THE COASTAL WATERS...AND CAUTIONARY STATEMENTS MAY BE
REQUIRED ON FRIDAY. STRENGTHENING WEDGE FRIDAY FORCES A PINCHED
PRESSURE GRADIENT...AND NE WINDS RISE TO AROUND 20 KTS ALL OF
FRIDAY...DRIVING SEAS UP TO 4-5 FT...EXCEPT SW OF BRUNSWICK COUNTY
WHERE THE WAVE SHADOW REGION WILL PERMIT ONLY MUCH SMALLER WAVE
HEIGHTS. GRADIENT WILL EASE AT LEAST MARGINALLY ON
SATURDAY...ALLOWING NE WINDS TO FALL TO 10-15 KTS...WITH SEAS
FOLLOWING TO 2-4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...REK/TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...BJR
MARINE...REK/TRA/JDW
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1253 PM CST TUE FEB 25 2014
.UPDATE...
ISSUED AT 1253 PM CST TUE FEB 25 2014
NO SIGNIFICANT CHANGES TO FORECAST WITH COLD CONDITIONS AND SUNNY
SKIES CONTINUING. WILL CONTINUE TO LOOK FOR AREAS NEEDING WIND
CHILL ADVISORY TONIGHT AS WELL AS POSSIBLE WIND ADVISORY FOR
EASTERN AREAS TOMORROW.
UPDATE ISSUED AT 1010 AM CST TUE FEB 25 2014
MAIN CHANGES FOR UPDATE WERE TO DECREASE SKY COVER AND ALLOW THE
WIND CHILL ADVISORY TO EXPIRE. WIND CHILLS VALUES HAD COME UP MOST
AREAS AND THE COLDEST NORTHERN LOCATIONS CONTINUE TO SEE GRADUALLY
INCREASING TEMPS...THOUGH A COLD DAY STILL EXPECTED WITH SINGLE
DIGIT HIGHS. MAIN CONCERNS LOOKING FORWARD ARE WIND CHILLS AGAIN
TONIGHT AND STRONGER WINDS ON WEDNESDAY...PARTICULARLY ACROSS THE
EAST.
UPDATE ISSUED AT 637 AM CST TUE FEB 25 2014
THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE REQUIRED.
ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN FORECAST CONCERN WILL BE WIND CHILL HEADLINES. EARLY
MORNING SURFACE ANALYSIS SHOWS SURFACE HIGH PRESSURE STRETCHING
FROM EASTERN MONTANA INTO SOUTHEAST SOUTH DAKOTA. TEMPERATURES
EARLY THIS MORNING WERE IN THE SINGLE DIGITS AND TEENS BELOW ZERO
WITH WINDS OF 5 TO 10 MPH. THIS HAS DROPPED WIND CHILLS INTO
ADVISORY LEVELS ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA...THE EXCEPTION BEING FAR WEST CENTRAL NORTH DAKOTA WHERE
WINDS REMAIN WEAKEST.
THE FAR SOUTHWEST HAS ALSO SEEN AN INCREASE IN MID AND HIGH LEVEL
CLOUDS EARLY THIS MORNING HELPING TEMPERATURES GAIN A FEW DEGREES
OVER THE PAST COUPLE OF HOURS. NOT CONFIDENT THAT TREND WILL
CONTINUE SINCE THE LATEST HRRR SUGGESTS THE CLOUDS WILL SINK SOUTH
AGAIN THIS MORNING. OVERALL...THE WIND CHILL HEADLINE IS STILL
SUPPORTED BY THE LATEST OBSERVATIONS AND WILL NOT MAKE ANY CHANGES
TO IT.
WIND CHILLS WILL AGAIN BE THE MAIN CONCERN TONIGHT WITH LOWS OF 5
TO 15 BELOW AND WIND SPEEDS OF 10 MPH...INCREASING TO NEAR 20 MPH
OVERNIGHT. THIS AGAIN DROPS WIND CHILLS IN THE 25 TO 35 BELOW
RANGE ACROSS MUCH OF THE NORTH AND EAST. WILL KEEP THINGS SIMPLE
AND NOT ISSUE ADDITIONAL HEADLINES...BUT EXPECT LATER SHIFTS WILL
LIKELY NEED TO CONSIDER THAT POSSIBILITY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN HIGHLIGHTS FOR THE EXTENDED WILL BE THE WELL BELOW NORMAL
TEMPERATURES AND SNOW CHANCES THIS WEEKEND. MODELS ARE IN FAIRLY
GOOD AGREEMENT SO USED A BLEND FOR THIS PACKAGE.
WEDNESDAY STILL LOOKS TO BE THE WARMEST DAY OF THE WEEK WITH HIGHS
GENERALLY FROM THE TEENS EAST TO THE MID 20S SOUTHWEST.
HOWEVER...IT WILL ALSO BE THE WINDIEST DAY OF THE PERIOD AS HIGH
PRESSURE SURGES INTO THE REGION. SNOW FROM MONDAY`S EVENT COMBINED
WITH THESE WINDS SHOULD GENERATE PATCHY TO AREAS OF BLOWING
SNOW...MAINLY ON WEDNESDAY AFTERNOON. WINDS WILL DECREASE RAPIDLY
WEDNESDAY NIGHT AS HIGH PRESSURE SETTLES ACROSS THE REGION. COLD
AND DRY CONDITIONS WILL CONTINUE ACROSS THE REGION THURSDAY AS
HIGH PRESSURE SHIFTS EAST OF THE REGION.
BY FRIDAY...A REINFORCING COLD FRONT WILL PUSH THROUGH THE
NORTHERN PLAINS...WITH A BAROCLINIC ZONE SETTING UP OVER
SOUTHWESTERN NORTH DAKOTA. THIS WILL GENERATE A SLIGHT CHANCE FOR
SNOW OVER SOUTHWESTERN NORTH DAKOTA FRIDAY INTO FRIDAY NIGHT.
A SHORTWAVE ROTATING OVER THE NORTHERN ROCKIES AND INTO THE
NORTHERN PLAINS THIS WEEKEND IS PROGGED TO LIFT THE SNOW CHANCES
NORTH SATURDAY AND SUNDAY. HOWEVER...GIVEN THE WEAK UPPER LEVEL
FORCING...SNOW AMOUNTS ARE EXPECTED TO REMAIN FAIRLY LIGHT.
AS THE UPPER WAVE DEPARTS THE STATE MONDAY...DRY CONDITIONS ARE
EXPECTED BY THE BEGINNING OF THE NEXT WORK WEEK. COLD TEMPERATURE
ARE FORECAST TO CONTINUE AS WELL WITH HIGHS IN THE SINGLE DIGITS
ABOVE ZERO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1253 PM CST TUE FEB 25 2014
VFR CONDITIONS EXPECTED AT ALL SITES AS HIGH PRESSURE AND CLEAR
SKIES DOMINATE INTO WEDNESDAY. STRONGER WINDS WILL DEVELOP ON
WEDNESDAY...ESPECIALLY ACROSS THE EAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JNS
SHORT TERM...CK
LONG TERM...TM
AVIATION...JNS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1010 AM CST TUE FEB 25 2014
.UPDATE...
ISSUED AT 1010 AM CST TUE FEB 25 2014
MAIN CHANGES FOR UPDATE WERE TO DECREASE SKY COVER AND ALLOW THE
WIND CHILL ADVISORY TO EXPIRE. WIND CHILLS VALUES HAD COME UP MOST
AREAS AND THE COLDEST NORTHERN LOCATIONS CONTINUE TO SEE GRADUALLY
INCREASING TEMPS...THOUGH A COLD DAY STILL EXPECTED WITH SINGLE
DIGIT HIGHS. MAIN CONCERNS LOOKING FORWARD ARE WIND CHILLS AGAIN
TONIGHT AND STRONGER WINDS ON WEDNESDAY...PARTICULARLY ACROSS THE
EAST.
UPDATE ISSUED AT 637 AM CST TUE FEB 25 2014
THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE REQUIRED.
ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN FORECAST CONCERN WILL BE WIND CHILL HEADLINES. EARLY
MORNING SURFACE ANALYSIS SHOWS SURFACE HIGH PRESSURE STRETCHING
FROM EASTERN MONTANA INTO SOUTHEAST SOUTH DAKOTA. TEMPERATURES
EARLY THIS MORNING WERE IN THE SINGLE DIGITS AND TEENS BELOW ZERO
WITH WINDS OF 5 TO 10 MPH. THIS HAS DROPPED WIND CHILLS INTO
ADVISORY LEVELS ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA...THE EXCEPTION BEING FAR WEST CENTRAL NORTH DAKOTA WHERE
WINDS REMAIN WEAKEST.
THE FAR SOUTHWEST HAS ALSO SEEN AN INCREASE IN MID AND HIGH LEVEL
CLOUDS EARLY THIS MORNING HELPING TEMPERATURES GAIN A FEW DEGREES
OVER THE PAST COUPLE OF HOURS. NOT CONFIDENT THAT TREND WILL
CONTINUE SINCE THE LATEST HRRR SUGGESTS THE CLOUDS WILL SINK SOUTH
AGAIN THIS MORNING. OVERALL...THE WIND CHILL HEADLINE IS STILL
SUPPORTED BY THE LATEST OBSERVATIONS AND WILL NOT MAKE ANY CHANGES
TO IT.
WIND CHILLS WILL AGAIN BE THE MAIN CONCERN TONIGHT WITH LOWS OF 5
TO 15 BELOW AND WIND SPEEDS OF 10 MPH...INCREASING TO NEAR 20 MPH
OVERNIGHT. THIS AGAIN DROPS WIND CHILLS IN THE 25 TO 35 BELOW
RANGE ACROSS MUCH OF THE NORTH AND EAST. WILL KEEP THINGS SIMPLE
AND NOT ISSUE ADDITIONAL HEADLINES...BUT EXPECT LATER SHIFTS WILL
LIKELY NEED TO CONSIDER THAT POSSIBILITY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN HIGHLIGHTS FOR THE EXTENDED WILL BE THE WELL BELOW NORMAL
TEMPERATURES AND SNOW CHANCES THIS WEEKEND. MODELS ARE IN FAIRLY
GOOD AGREEMENT SO USED A BLEND FOR THIS PACKAGE.
WEDNESDAY STILL LOOKS TO BE THE WARMEST DAY OF THE WEEK WITH HIGHS
GENERALLY FROM THE TEENS EAST TO THE MID 20S SOUTHWEST.
HOWEVER...IT WILL ALSO BE THE WINDIEST DAY OF THE PERIOD AS HIGH
PRESSURE SURGES INTO THE REGION. SNOW FROM MONDAY`S EVENT COMBINED
WITH THESE WINDS SHOULD GENERATE PATCHY TO AREAS OF BLOWING
SNOW...MAINLY ON WEDNESDAY AFTERNOON. WINDS WILL DECREASE RAPIDLY
WEDNESDAY NIGHT AS HIGH PRESSURE SETTLES ACROSS THE REGION. COLD
AND DRY CONDITIONS WILL CONTINUE ACROSS THE REGION THURSDAY AS
HIGH PRESSURE SHIFTS EAST OF THE REGION.
BY FRIDAY...A REINFORCING COLD FRONT WILL PUSH THROUGH THE
NORTHERN PLAINS...WITH A BAROCLINIC ZONE SETTING UP OVER
SOUTHWESTERN NORTH DAKOTA. THIS WILL GENERATE A SLIGHT CHANCE FOR
SNOW OVER SOUTHWESTERN NORTH DAKOTA FRIDAY INTO FRIDAY NIGHT.
A SHORTWAVE ROTATING OVER THE NORTHERN ROCKIES AND INTO THE
NORTHERN PLAINS THIS WEEKEND IS PROGGED TO LIFT THE SNOW CHANCES
NORTH SATURDAY AND SUNDAY. HOWEVER...GIVEN THE WEAK UPPER LEVEL
FORCING...SNOW AMOUNTS ARE EXPECTED TO REMAIN FAIRLY LIGHT.
AS THE UPPER WAVE DEPARTS THE STATE MONDAY...DRY CONDITIONS ARE
EXPECTED BY THE BEGINNING OF THE NEXT WORK WEEK. COLD TEMPERATURE
ARE FORECAST TO CONTINUE AS WELL WITH HIGHS IN THE SINGLE DIGITS
ABOVE ZERO.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 637 AM CST TUE FEB 25 2014
EARLY MORNING SATELLITE IMAGERY SHOWS VFR CONDITIONS ACROSS NORTH
DAKOTA. WILL CARRY VFR AT ALL TERMINAL LOCATIONS...HOWEVER HAVE
SOME CONCERN CLOUDS COULD DEVELOP TODAY AS A BAND OF H925-H85
MOISTURE MOVES ACROSS NORTH DAKOTA. THE HRRR EVEN SUGGESTS THERE
IS SOME POTENTIAL FOR MVFR CEILINGS FROM LATE MORNING INTO THE
AFTERNOON ACROSS THE WEST...POSSIBLY IMPACTING WILLISTON AND
DICKINSON. HAVE FORECAST SCATTERED CLOUDS AROUND 3500 FT...BUT DID
NOT NOT CARRY A CEILING SINCE FORECAST SOUNDINGS SUGGEST ANY
AVAILABLE MOISTURE SHOULD BE SHALLOW. WINDS WILL START LIGHT...BUT
WILL INCREASE FROM FROM THE NORTHWEST LATER THIS MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JNS
SHORT TERM...CK
LONG TERM...TM
AVIATION...CK
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
333 PM CST TUE FEB 25 2014
.DISCUSSION...
FRONT IS NOW PUSHING INTO NRN PORTIONS OF SE TX. SHOULD BE BETWEEN
I-10 AND THE COAST AROUND MIDNIGHT AND OFF THE BEACHES BY 4AM
(EFFECTIVELY ENDING SEA FOG ISSUES FOR A FEW DAYS). STARTING TO
SEE SOME SCT PRECIP DEVELOP ACROSS S PARTS OF THE AREA AND EXPECT
IT TO GRADUALLY INCREASE IN COVERAGE AHEAD OF, AND ESPECIALLY
BEHIND, THE FRONT. HRRR MODEL AND TO A DEGREE NAM12 HAS DONE
FAIRLY WELL WITH RAINFALL DEPICTION (OR LACK THEREOF) SO FAR TODAY
AND SHORT TERM FCST WAS TRENDED THAT WAY. GFS/ECMWF HAVE BEEN
HORRIBLY OVERDONE BOTH IN COVERAGE & AMOUNTS UP TO THIS TIME.
PERIODS OF PRECIP WILL LIKELY CONTINUE THRU WED IN ASSOCIATION
WITH H85 FRONT AND UPPER IMPULSES RIDING FURTHER OVERHEAD IN THE
WRLY FLOW ALOFT. CONSIDERING STRONG CAA, CLOUDINESS AND PRECIP THE HIGHS
FOR THE 24 HOUR PERIOD WILL OCCUR AROUND MIDNIGHT FOLLOWED BY
FALLING AND/OR STEADY TEMPS IN THE 40S WED. RAIN SHOULD TAPER OFF
WED EVENING.
COOL WX CONTINUES THURS BUT ONSHORE WIND WILL BE RESUMING AS HIGH
PRES MOVES EAST AND NEXT SHORTWAVE STARTS DIGGING SEWD DOWN THE
4-CORNERS AREA. THIS DISTURBANCE ISN`T AS IMPRESSIVE AS PREVIOUS
DAYS AND DON`T ANTICIPATE MUCH OF AN IMPACT HERE AS IT MOVES ALONG
THE RED RIVER FRIDAY...AS BEST ENERGY WILL BE WELL NORTH AND A
CAP SHOULD BE IN PLACE. FURTHER LOWERED POPS.
WARMING TREND CONTINUES THRU THE WEEKEND WITH ONSHORE FLOW IN
PLACE. APPEARS THAT WE`LL PROBABLY HAVE ANOTHER COASTAL FOG EVENT
BUT LOOKS LIKE MARDI GRAS PARADES SHOULD OTHERWISE BE DRY PRIOR TO
MID TO LATE SUNDAY AFTN. NEXT STORM SYSTEM APPROACHES FROM THE
WEST LATE IN THE WEEKEND AND KEPT 20-40% POPS IN PLACE SUN AFTN/NIGHT
AHEAD OF THE NEXT FRONT THAT`LL BE MOVING THRU SUNDAY NIGHT OR
MONDAY. KNOCKED TEMPS DOWN EARLY NEXT WEEK (MAYBE NOT ENOUGH) AS
1040+MB HIGH DROPS INTO THE PLAINS. 47
&&
.MARINE...
SEA FOG WILL CONTINUE OVER THE GULF WATERS THIS AFTERNOON. AM
EXPECTING THE FOG TO REDEVELOP AND BECOME DENSE OVER THE BAYS LATER
THIS AFTERNOON AND EVENING. THE FOG WILL CLEAR OUT BETWEEN MIDNIGHT
AND SUNRISE AS A COLD FRONT PUSHES THROUGH THE BAYS AND OFF THE
COAST. THE MODELS HAVE BEEN FAIRLY CONSISTENT THE PAST FEW DAYS AND
AM FAIRLY CONFIDENT ON THE TIMING. EXPECT THE FRONT TO MOVE THROUGH
THE BAYS BY AROUND 3 AM AND THEN BEYOND 20 NM OFFSHORE BY 4 AM. THE
12Z MODEL RUN AND GUIDANCE FROM THIS MORNING FORECASTED SLIGHTLY
HIGHER WINDS...INDICATING THAT SMALL CRAFT ADVISORIES ARE LIKELY FOR
THE GULF WATERS AND MATAGORDA BAY. WOULD NOT BE SURPRISED IF WINDS
INCREASE TO BETWEEN 20 AND 25 KNOTS FOR AT LEAST MOST OF THE LOWER
PART OF GALVESTON BAY...ALSO. EXPECT THE NORTHEASTERLY WINDS TO
DIMINISH WEDNESDAY NIGHT AND THURSDAY. ANOTHER FOG EVENT MAY DEVELOP
BY LATE THIS WEEK AS ONSHORE REDEVELOPS. 40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 43 43 33 57 42 / 70 60 20 10 10
HOUSTON (IAH) 49 49 36 59 43 / 70 70 30 10 10
GALVESTON (GLS) 54 54 42 55 53 / 70 60 40 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 4 AM CST WEDNESDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20
TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$