Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/03/14
AREA FORECAST DISCUSSION
NWS RENO NV
334 AM PST SAT FEB 1 2014
.SYNOPSIS...
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE UPCOMING WEEK.
WEAK LOW PRESSURE AND COLD FRONT PASSAGES MAY BRING LIGHT SNOW
SHOWERS AT TIMES SUNDAY THROUGH MONDAY, BUT LITTLE OR NO ACCUMULATION
IS EXPECTED. STRONGER LOW PRESSURE AND INCREASING PACIFIC MOISTURE
COULD BRING ADDITIONAL CHANCES FOR SNOW LATER IN THE WEEK AND
INTO NEXT WEEKEND.
&&
.SHORT TERM...
LOCALIZED LIGHT SNOW AROUND LEE VINING AND JUNE LAKE APPEARS TO
HAVE ENDED BASED ON MOST RECENT WEB CAMERA AND INFRARED SATELLITE
IMAGES. ONLY OTHER WEATHER CONCERN TODAY IS PATCHY FREEZING FOG
THIS MORNING. SO FAR ONLY KTRK HAS REPORTED ANY REDUCTION IN
VISIBILITY. HRRR GUIDANCE FAVORS AN AREA OF FOG DEVELOPING IN THE
CARSON SINK INCLUDING FALLON DURING THE NEXT FEW HOURS, AND
PERSISTING UNTIL MIDDAY. AT THIS TIME, WILL KEEP MENTION OF
PATCHY FOG IN THIS AREA AND PARTS OF THE SNOW COVERED CARSON
VALLEY, ALONG WITH THE USUAL SIERRA VALLEYS NEAR AND NORTH OF
TRUCKEE.
OTHERWISE, DRY AND MOSTLY CLEAR CONDITIONS WILL PREVAIL TODAY
WITH SHORTWAVE RIDGE OVERHEAD. TEMPERATURES WILL ONLY BE ABLE TO
SLOWLY RISE TO AROUND 40 DEGREES OVER MUCH OF WESTERN NEVADA, WITH
SNOW COVERED AREAS UP TO 5 DEGREES COOLER.
FOR TONIGHT, LOW PRESSURE IS EXPECTED TO APPROACH THE NORTHERN
CALIFORNIA COAST. AHEAD OF THIS LOW, MID-HIGH LEVEL CLOUD COVER IS
LIKELY TO INCREASE AND THICKEN AS PACIFIC MOISTURE AND UPPER LEVEL
DIVERGENCE SPREADS OVER NORTHERN CA AND WESTERN NV. THIS WILL
LIMIT RADIATIONAL COOLING IN VALLEYS COMPARED TO EARLY THIS
MORNING, BUT TEMPERATURES WILL REMAIN CHILLY WITH LOWS MAINLY IN
THE TEENS TO LOWER 20S.
FOR SUNDAY AND SUNDAY NIGHT, THIS LOW IS PROJECTED TO CONTINUE
MOVING SOUTH ALONG THE CALIFORNIA COAST. WHILE THE MAIN
PRECIPITATION AREA WILL STAY WEST OF THE SIERRA, A DEFORMATION
ZONE SETTING UP OVER THE SIERRA LOOKS TO PROVIDE ENOUGH FORCING TO
PRODUCE SOME LIGHT SNOW SHOWERS MAINLY NEAR THE CREST. A FEW SNOW
SHOWERS ARE ALSO POSSIBLE IN FAR NORTHWEST NEVADA NEAR THE OREGON
BORDER AS A SEPARATE WEAK SHORTWAVE BRUSHES ACROSS EASTERN OREGON.
BY MONDAY AND MONDAY NIGHT, ANOTHER SHORTWAVE OVER THE NORTHWEST
US WILL TRACK SOUTHEAST, WITH A BACK DOOR COLD FRONT SLIDING SOUTH
ACROSS NEVADA. THERE IS SOME UNCERTAINTY AS TO HOW FAR WEST SNOW
SHOWERS WILL DEVELOP ALONG THE FRONT, ALTHOUGH THE OVERALL
GUIDANCE CONSENSUS SEEMS TO FAVOR A BETTER CHANCE OF LIGHT SNOW
SHOWERS BACKING INTO MORE OF WESTERN NEVADA. MOST OF THE REGION
ALREADY HAD A MENTION OF SNOW SHOWERS FOR MONDAY, WHICH WILL BE
EXTENDED INTO MONDAY NIGHT BASED ON THIS TREND. MJD
.LONG TERM...TUESDAY THROUGH SATURDAY...
LOW PRESSURE REMAINS OVER THE NORTHERN GREAT BASIN NEXT WEEK WITH
CONTINUED NORTHWEST FLOW ALOFT OVER NORTHERN CA/NV. TEMPERATURES
WILL REMAIN FAIRLY COLD THROUGH THE WEEK WITH COLD AIR ALOFT AND
NORTH WINDS LIMITING THE WARMING IN THE VALLEYS. THIS COLD AIR ALOFT
WILL ALSO PREVENT THE DEVELOPMENT OF STRONG INVERSIONS, RESULTING
IN FAVORABLE AIR QUALITY THROUGH NEXT WEEK.
MODELS ARE IN GOOD AGREEMENT WITH ANOTHER SHORTWAVE TROUGH DROPPING
THROUGH THE PAC NW WITH A BACK-DOOR COLD FRONT MOVING THROUGH THE
GREAT BASIN ON THURSDAY-FRIDAY. THE LATEST GFS IS ALSO SHOWING
CONVECTIVE SNOW SHOWERS ALONG THE FRONT THAT COULD POSSIBLY BRING
SNOW ACCUMULATIONS TO THE VALLEY FLOORS OF NORTHERN NEVADA ON
THURSDAY AND THURSDAY NIGHT. INTRODUCED A SLIGHT CHANCE OF SNOW
SHOWERS FOR THIS FRONTAL PASSAGE, WITH GFS/ECMWF SHOWING GOOD PRECIP
AGREEMENT AND STRONG FRONTOGENESIS. THIS COLD FRONT WILL ALSO BRING
ANOTHER REINFORCING COLD SHOT OF AIR WITH HIGH TEMPS ONLY IN THE
20S-30S ON FRIDAY.
MEDIUM RANGE MODELS ARE ALSO COMING INTO GOOD AGREEMENT (PRETTY GOOD
FOR THIS FAR OUT) WITH ADDITIONAL MOISTURE REACHING THE PAC NW AND
NORTHERN CA COAST NEXT WEEKEND. THIS COMES AS THE EASTERN PACIFIC
RIDGE GETS PINCHED OFF OVER THE BERING SEA AND ALLOWS A DEEP LOW
PRESSURE ANOMALY TO SET UP OVER THE GULF OF ALASKA (NEGATIVE PNA).
THIS SYNOPTIC PATTERN WOULD BE FAVORABLE FOR SEEING ADDITIONAL
PRECIP IN THE SIERRA FOR NEXT WEEKEND AND INTO THE FOLLOWING
WEEK. HOON
&&
.AVIATION...
MVFR/IFR FZFG THIS MORNING AT KTRK. ABOUT A 50 PERCENT CHANCE OF
FZFG AT KTRK FOR SUNDAY MORNING, WHICH WILL DEPEND ON HOW QUICKLY
THICKER CIRRUS SPREADS INTO THE SIERRA. OTHERWISE, VFR CONDITIONS
WITH LIGHT WINDS AT OTHER AREA TERMINALS. HOON
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
835 PM MST SUN FEB 2 2014
.UPDATE...
&&
.AVIATION...WK DENVER CYCLONE IS SITTING OVER DIA WITH LOW CLOUDS
AND FOG BEGINNING TO WRAP AROUND IT SWRN WELD COUNTY. IF WINDS AT
DIA SWITCH TO A MORE WNW COMPONENT DURING THE NEXT FEW HOURS THEN
THAT WOULD INCREASE THE CHANCES OF DENSE FOG. LATEST HRRR SWITCHES
WIND TO WNW FOR A FEW HOURS AROUND 05Z AND THEN BACK TO SWLY BY
09Z. THUS THERE LOOKS LIKE A 4 HOUR WINDOW FOR POTENTIAL DENSE
FOG AT DIA.
&&
.PREV DISCUSSION... /ISSUED 648 PM MST SUN FEB 2 2014/
UPDATE...
SHORT TERM...TEMPS HAVE ALREADY REACHED PREVIOUS MIN TEMP FCST SO
HAVE LOWERED THEM TO MATCH CURRENT TRENDS. AREAS OF PATCHY FOG HAS
DEVELOPED ALONG THE FRONT RANGE AND NERN PLAINS AND MAY BECOME
MORE WIDESPREAD IN THE NEXT FEW HOURS WITH SOME DENSE FOG POSSIBLE
AVIATION...CEILINGS HAVE DROPPED TO 200 FT WITH VISIBILITIES DOWN
TO 2 MILES. WILL LIKELY SEE SOME DENSE FOG AT SOME POINT IN THE
NEXT FEW HOURS. MAY SEE LOW CLOUDS AND FOG LINGER THRU 11Z.
PREV DISCUSSION... /ISSUED 401 PM MST SUN FEB 2 2014/
UPDATE...
AVIATION...SOME CONCERN THAT DENSE FOG MAY DEVELOP EARLY THIS
EVENING IN THE 02Z-07Z TIMEFRAME ALONG THE FRONT RANGE AND OVER
THE PLAINS ALONG THE PLATTE RIVER VALLEY. LATEST SFC OBS SHOW
VISIBILITIES IN HAZE ALREADY DROPPING DOWN TO 4-5 MILES. WILL
MENTION A TEMPO GROUP IN THE NEXT TAF FOR VISIBILITIES IN THE 1-3
MILE RANGE AT BJC AND DIA BETWEEN 02Z AND 06Z TO START WITH.
PREV DISCUSSION... /ISSUED 258 PM MST SUN FEB 2 2014/
SHORT TERM...A WEAK UPPER LEVEL HIGH PRESSURE RIDGE WILL CONTINUE
TO PROPAGATE EASTWARD OVER NORTH CENTRAL AND NORTHEAST COLORADO
THIS EVENING...MOSTLY CLEAR SKIES...STRONG SURFACE BASED
INVERSIONS AND VERY COLD TEMPERATURES. LOW LYING AREAS SUCH AS
ALONG CREEKS AND RIVER BOTTOMS MAY ONCE AGAIN SEE POCKETS OF
SHALLOW FOG FORM THIS EVENING. BUT NOTHING LIKE THE WIDESPREAD
FOG WE SAW LAST NIGHT DUE TO DRIER BOUNDARY LAYER CONDITIONS...A
SLIGHTLY STRONGER DRAINAGE FLOW AND WITH THE INCREASE IN HIGH
CLOUDS EXPECTED LATER TONIGHT. SUB-ZERO AND SINGLE DIGIT LOW
TEMPERATURES WILL STILL PREVAIL TONIGHT...READINGS WELL BELOW
AVERAGE FOR THE DATE. ON MONDAY THE UPPER RIDGE MOVES EAST AS A
SHORTWAVE TROUGH DROPS IN OVER UTAH AND WESTERN COLORADO. WINDS
ALOFT BECOME SOUTHWESTERLY. PACIFIC MOISTURE CARRIED ALONG BY
THIS FLOW WILL SPREAD OVER COLORADO DURING THE DAY CREATING MOSTLY
CLOUDY TO OVERCAST SKIES BY MIDDAY. MODELS INDICATE AREAS OF LIGHT
QPF AND SNOW ACCUMULATION POPPING UP IN MTN AREAS MOSTLY WEST OF
THE DIVIDE IN THE MORNING...AND GREATER COVERAGE DURING THE
AFTERNOON WITH AN INCREASE IN DEEP LAYER QG ASCENT AND STEEPENING
LAPSE RATES. GOING WITH LIKELY POPS IN THE MTN ZONES BY AFTERNOON
AND CHANCE POPS FOR THE MOUNTAIN VALLEYS. HOWEVER NEW SNOW
ACCUMULATIONS SHOULD BE ON THE LIGHT SIDE UP TO THIS POINT. AREAS
EAST OF THE MOUNTAINS SHOULD REMAIN DRY DURING THE NEXT 24 HOURS
WITH SOUTHWEST FLOW ALOFT AND A WEST-SOUTHWESTERLY LOW-LEVEL FLOW
DOWNSLOPING OFF THE FRONT RANGE AND PALMER DIVIDE. HOWEVER THE
PLAINS WILL ALSO SEE A STEADY INCREASE IN MID AND HIGH-LEVEL
CLOUDS THROUGH THE DAY. TEMPERATURES ON MONDAY WILL BE MORE
UNIFORM IN COVERAGE DUE TO MORE WIND AND CLOUD COVER. READINGS
STILL WELL BELOW AVERAGE FOR THE DATE.
LONG TERM...UPPER LOW WHICH IS NOW OVER THE NORTHERN CALIFORNIA
COAST WILL MOVE INLAND OVER THE DESERT SOUTHWEST ON MONDAY AND
TRACK INTO THE TEXAS PANHANDLE BY EARLY TUESDAY. AN ASSOCIATED
COLD FRONT WILL MOVE OVER NORTHEAST COLORADO MONDAY NIGHT WITH
SHALLOW UPSLOPE FLOW DEVELOPING DURING THE NIGHT. THE BRUNT OF
THE FORCING WILL BE WELL SOUTH OF BOU CWA BUT STILL SOME LIGHT TO
MODERATE ASCENT EXPECTED OVER MUCH OF THE CWA. MAIN CHANGE TO
FORECAST WAS TO INCREASE POPS TO LIKELY OVER MUCH OF THE PLAINS
AND FOOTHILLS FOR LATE MONDAY NIGHT AND TUESDAY WITH AMPLE
MOISTURE...UPSLOPE AND WEAK ASCENT. OVERALL SNOWFALL AMOUNTS WILL
BE ON THE LIGHTER SIDE WITH HEAVIEST AMOUNTS DRAPED OVER THE
PALMER DIVIDE. STILL NO HILITES EXPECTED AWAY FROM THE BRUNT OF
THE UPWARD FORCING.
A MUCH COLDER AIRMASS WILL SLIDE IN BEHIND THIS WAVE FOR TUESDAY
THROUGH THURSDAY WITH HIGH TEMPERATURES ONLY IN THE SINGLE DIGITS
AND LOWS AT NIGHT DROPPING BELOW ZERO. THERE MAY BE CONTINUED
VERY LIGHT SNOW ON WEDNESDAY AND THURSDAY WITH SHALLOW UPSLOPE
FLOW AND SOME OVERRUNNING MOISTURE STREAMING IN FROM THE WEST.
NEXT BIGGER POTENTIAL STORM LOOMS FOR FRIDAY NIGHT AND SATURDAY
BUT LONG RANGE MODELS ARE QUITE VARIED IN THEIR SOLUTIONS. THE
EUROPEAN IS FURTHER SOUTH AND DEVELOPS A CLOSED LOW NEAR THE 4
CORNERS BEFORE LIFTING OUT OVER THE PLAINS ON SATURDAY AS AN OPEN
WAVE. THE GFS IS A BIT FASTER BUT HAS TRENDED FURTHER WEST OVER
THE PAST FEW RUNS. HAVE INCREASED POPS A BIT FOR LATE FRI NIGHT AS
STILL POTENTIAL IT MAY DIG FURTHER SOUTH AND CONSOLIDATE.
AVIATION...VFR CONDITIONS WILL CONTINUE AT DENVER AREA TERMINALS
THROUGH MONDAY AFTERNOON. CLEAR SKIES THIS EVENING WILL BEGIN
FILLING WITH HIGH CLOUDS LATE TONIGHT AND LOWER MID-LEVEL CLOUDS
ON MONDAY. HOWEVER CLOUD BASES SHOULD REMAIN ABOVE 8000 FEET AGL
THROUGH 00Z/TUE. NO PRECIPITION ANTICIPATED DURING THIS 24 HOUR
PERIOD. WINDS LIGHT AND VARIABLE REST OF THIS AFTERNOON...BECOMING
DRAINAGE AT SPEEDS UNDER 10 KTS OVERNIGHT. ON MONDAY...PREVAILING
WINDS WILL BE SOUTH-SOUTHWEST 6-12KTS FOR MOST OF THE DAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM....ENTREKIN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
629 PM MST SUN FEB 2 2014
.UPDATE...
ISSUED AT 614 PM MST SUN FEB 2 2014
UPGRADED THE WINTER STORM WATCHES TO WARNINGS FOR OUR CENTRAL AND
SOUTHERN MOUNTAIN ZONES OF WESTERN COLORADO AND THE MOUNTAINS OF
SE UTAH. THIS WAS MAINLY DONE BECAUSE THE ONSET TIMES FOR SNOWFALL
WILL OCCUR DURING THE FIRST PERIOD...LATER TONIGHT. FORECAST
SNOWFALL AMOUNTS FOR THE WARNED MOUNTAIN ZONES STILL SEEM
REASONABLE.
WILL NEED TO TAKE A LOOK AT SOME OTHER ZONES WHERE WE PRESENTLY
HAVE BORDERLINE ADVISORY CRITERIA SNOWFALL AMOUNTS IN THE
FORECAST.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 308 PM MST SUN FEB 2 2014
TWO WEATHER SYSTEMS BLEND TOGETHER TO FORM THE NEXT WINTER STORM
TO IMPACT THE REGION. IN THE NEAR TERM...THE CIRCULATION OVER
CENTRAL CALIFORNIA IS PROGGED TO DROP SOUTHEAST INTO ARIZONA ON
MONDAY. A DEFORMATION ZONE DEVELOPS OVER WEST CENTRAL COLORADO
WHERE THE NRN AND SRN STREAM MEGRE. HIGH CLOUDS SPREAD FROM THE
SOUTHWEST THIS EVENING WITH THE MID LEVEL MOISTURE ARRIVING LATE
TONIGHT. THE RAP MODEL SHOWS THE THREAT OF SNOW IN THE WESTERN
SLOPE MOUNTAIN BEGINNING AFTER MIDNIGHT...BUT DYNAMICAL ASCENT
DOES NOT REACH SOUTHWEST COLORADO UNTIL MONDAY MORNING. SNOW
EXPANDS AND ENCOMPASSES THE MOUNTAIN AREAS BY NOONTIME MONDAY.
STATIC STABILITY IS LOW WITH MODEL DATA DEPICTING SOME CAPE
VALUES. THIS SUGGESTS THAT DEVELOPING SNOW CLOUDS WILL HAVE SOME
UPDRAFTS THAT SHOULD ENHANCE THE OROGRAPHIC AND DYNAMICAL
COMPONENTS. SURFACE PROGS SHOWS A BROAD AREA OF LOW PRESSURE
CENTERED OVER SOUTHWEST COLORADO. GIVEN THESE FACTORS...BELIEVE
THAT HOISTING THE WINTER STORM WATCH IS THE PRUDENT THING TO DO.
HIGH COUNTRY QPF VALUES SUPPORT AREAS OF WARNING CRITERIA BEING
REACHED BY TUESDAY AFTERNOON. EXPECT SOME SNOW TO EXPAND INTO THE
LOWER VALLEYS AND LATER SHIFTS MAY NEED TO CONSIDER ADDING WINTER
WEATHER ADVISORIES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 308 PM MST SUN FEB 2 2014
AN AMPLIFIED EASTERN PACIFIC/ALASKAN RIDGE IN THE WEST AND A STRONG
BERMUDA HIGH OVER THE CARIBBEAN WILL KEEP A BROAD...ACTIVE TROF
ACROSS MUCH OF THE CONUS THIS WEEK. THE PACIFIC JET IN THE BASE OF
THIS TROF WILL DIVE FROM THE PACIFIC NORTHWEST INTO THE DESERT
SOUTHWEST BEFORE ARCING BACK INTO THE UPPER MIDWEST THROUGH MUCH OF
THIS PERIOD. MORE ORGANIZED PIECES OF ENERGY MOVING THROUGH THE FLOW
WILL FORCE THE JET TO BECOME MORE CYCLONICALLY CURVED NEAR THE 4
CORNERS AT EACH END OF THE NEW WORK WEEK...WHICH WILL ADD SOME
ADDITIONAL ASCENT OVER OUR REGION. WITH THE JET TO OUR
SOUTH...COLD TEMPERATURES WILL BE IN PLACE. THIS COULD LEAVE HIGH
TEMPERATURES SOME 20 DEGREES BELOW NORMAL ACROSS PORTIONS OF THE
CWA. PIECES OF UNORGANIZED AND ORGANIZED ENERGY AND PACIFIC
MOISTURE PUSHED ALONG WITH THE JET WILL ALSO BRING PERIODS OF
SNOW...HEAVY AT TIMES...TO OUR CWA MOUNTAINS WITH VALLEYS LIKELY
TO SEE SOME WHITE STUFF AS WELL.
TUESDAY MORNING THE FIRST OF THE MORE ORGANIZED SYSTEMS WILL BE OVER
THE CWA. THE PACIFIC WAVE WILL HAVE MOVED INTO THE SOUTHERN PLAINS
BY SUNRISE...BUT THE UPSTREAM ARCTIC WAVE WILL BE SWINGING ACROSS
THE WYOMING AND NORTHERN COLORADO ROCKIES THROUGH THE DAY. 290K
MOISTURE TRANSPORT VECTORS SHOW THIS WAVE BRINGING IN ADDITIONAL
MOISTURE AND PWAT TOPS OUT AT NEAR .25 INCH. THIS IS HALF OF LAST
WEEK BUT WITH STRONGER INSTABILITY IN PLACE...IT SHOULD BE ABLE TO
CONTINUE THE THREAT OF MODERATE TO HEAVY MOUNTAIN SNOW SHOWERS
THROUGH THE DAY. CROSS SECTIONS SHOW NEG EPV NEAR MOUNTAIN LEVEL
WITH WESTERLY OROGRAPHICS HELPING TO RELEASE THIS INSTABILITY.
MODELS ALSO SUGGEST THIS WAVE WILL BE GIVING THE TRUE ARCTIC FRONT
A SHOVE SOUTHWARD INTO NORTHWEST COLORADO THROUGH THE AFTERNOON.
TEMPERATURES COULD VERY WELL BE DROPPING THROUGH THE MID TEENS
NORTH OF HIGHWAY 40 AFTER MID DAY. THIS FRONT WOULD ALSO SERVE AS
ADDITIONAL LOW LEVEL FOCUS FOR SNOW IN THE NORTHERN VALLEYS WHERE
DENDRITIC TEMPERATURES WILL BECOME MORE FAVORABLE FOR LOW DENSITY
SNOW PRODUCTION.
A SHORT LULL CAN BE EXPECTED LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING IN THE WAKE OF THIS WAVE. THETA SURFACES REVEAL PACIFIC
MOISTURE ENTRAINING IN THE FLOW OVER THE GREAT BASIN. FAVORABLE
OROGRAPHICS THROUGH A SATURATED DENDRITIC LAYER OVER THE HIGH
COUNTRY LOOKS TO KEEP LIGHT SNOW PROCESSES GOING...WITH AFTERNOON
INSTABILITY BOOSTING RATES AT TIMES. IT COULD BE A PROLONGED PERIOD
OF LIGHT SNOW FOR MANY AREAS BUT AT THIS TIME UNSURE OF IMPACTS
SUITED FOR WINTER HEADLINES. LARGE SCALE ASCENT...MOISTURE AND
INSTABILITY ALL GET A STRONG BOOST BY FRIDAY AS AGAIN WEST COAST
ENERGY MERGES OVER THE ROCKIES. THIS STORM HAS THE POTENTIAL TO
BRING ANOTHER ROUND OF SIGNIFICANT SNOW THE REGION THROUGH GOING
INTO THE WEEKEND. THIS STORM IS MUCH COLDER AND NOT AS MOIST BUT
TEMPERATURES SUGGEST THE LOWER DENSITY SNOW WILL BE EASIER TO PILE
UP. THERE IS ALSO A DEEPER FOCUS FOR ASCENT WITH A COLD FRONT
PUSHING THROUGH THE CWA FRIDAY EVENING...STAY TUNED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 308 PM MST SUN FEB 2 2014
VFR CONDITIONS WILL PREVAIL UNTIL ABOUT 09Z...THEN CIGS WILL BEGIN
TO LOWER ACROSS SOUTHWEST AND WEST CENTRAL COLORADO WITH
INCREASING -SN FORMING OVER THE PEAKS. MOUNTAIN TOPS BECOME
OBSCURED BY 14Z WITH VIS 5SM -SN AT KTEX. CONDITIONS WILL SLOWLY
DETERIORATE AT SKI COUNTRY TAF SITES WITH IFR CIGS/VIS POSSIBLE FROM
PASSING BANDS OF SNOW...ESPECIALLY AFTER 18Z. THERE IS A 30
PERCENT CHANCE THAT SNOW WILL IMPACT LOWER ELEVATED TAF SITES SUCH
AS KGJT...KMTJ AND KRIL AS WELL.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING FROM 3 AM MONDAY TO 11 PM MST TUESDAY
COZ009-013-018-019.
WINTER STORM WARNING FROM 5 AM MONDAY TO 11 PM MST TUESDAY
ABOVE 7500 FEET FOR COZ017.
WINTER STORM WARNING FROM 5 AM MONDAY TO 11 PM MST TUESDAY
COZ010-012.
UT...WINTER STORM WARNING FROM 5 AM MONDAY TO 11 PM MST TUESDAY ABOVE
7500 FEET FOR UTZ028.
&&
$$
UPDATE...JRP
SHORT TERM...PF
LONG TERM...15
AVIATION...PF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
712 PM EST SUN FEB 2 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE OFF THE SOUTH COAST THIS EVENING...THEN
STALL WELL SOUTH OF NEW ENGLAND OVERNIGHT. LOW PRESSURE WILL MOVE
ALONG THIS FRONT...BRINGING A PERIOD OF LIGHT SNOW ACROSS
SOUTHEASTERN NEW ENGLAND LATE TONIGHT AND MONDAY. A SIGNIFICANT
WINTER STORM IS EXPECTED TO IMPACT SOUTHERN NEW ENGLAND TUESDAY
NIGHT INTO WEDNESDAY. DETAILS OF THIS SYSTEM ARE STILL UNCERTAIN.
BELOW NORMAL TEMPERATURES THEN PREVAIL THROUGH THE END OF THIS
WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
7 PM UPDATE...
SURFACE COLD FRONT STRUGGLING TO PUSH EAST ACROSS SOUTHERN NEW
ENGLAND THIS EVENING. AS OF 7 PM...THIS FRONT WAS LOCATED ACROSS
SOUTHEAST MA AND SOUTHERN RI. THIS BOUNDARY IS EXPECTED TO MOVE
JUST OFFSHORE OVERNIGHT.
ADJUSTED PRECIPITATION CHANCES THIS EVENING INTO MONDAY MORNING.
02/21Z HRRR MATCHED OUR EXPECTATIONS THE BEST...SO USED IT AS A
GUIDE FOR THOSE ADJUSTMENTS.
OTHERWISE...JUST BROUGHT NEAR-TERM CONDITIONS BACK INTO LINE WITH
OBSERVED TRENDS.
PREVIOUS DISCUSSION...
COLD FRONT SLOWLY CROSSING INTO CENTRAL NEW ENGLAND AT 21Z. LINE
OF SHOWERS OUT WELL AHEAD OF THIS FRONT PUSHING THROUGH CENTRAL
AND S MA INTO RI/N CT...THOUGH TENDING TO WEAKEN AS MOST OF THE
LIFT HAS MOVED OFFSHORE. GENERALLY LESS THAN ONE TENTH OF AN INCH
OF RAIN HAS FALLEN ACROSS CENTRAL AND NORTHERN AREAS THROUGH 21Z.
TEMPS ROSE THROUGH THE MID 50S ACROSS E MA...INCLUDING A RECORD
TYING 55 DEGREES AT KBOS.
EXPECT FRONT TO CONTINUE TO SLOW PUSH S THIS EVENING...MOVING OFF
THE S COAST BY AROUND MIDNIGHT WITH ANY LEFTOVER SHOWERS
DISSIPATING. CLOUDS WILL LINGER THOUGH AS MOISTURE FROM NEXT
SYSTEM BEGINS TO FORM WELL SW OF THE REGION.
ALREADY NOTING SOME MID LEVEL CLOUD ENHANCEMENT ON THE LATEST
WATER VAPOR SATELLITE IMAGERY ACROSS THE S CENTRAL STATES AS IT
STARTS TO SHIFT NE. SHORT RANGE MODELS CONTINUE TO SIGNAL A
DEVELOPING H85 RRQ JET UP TO 50-60 KT INTO THE DEVELOPING LOW AS
IT MOVES ACROSS THE CAROLINAS OVERNIGHT. WILL START TO SEE LEADING
EDGE OF THE MOISTURE FROM THE LOW WORK INTO S COASTAL AREAS. HAVE
BROUGHT CHANCE POPS IN. TEMPS WILL BE BORDERLINE BETWEEN RAIN AND
SNOW. CARRIED A MIX TO START.
COLDER AIR DOES FILTER IN BEHIND THE FRONT AS H85 TEMPS FALL TO -1C
TO -5C BY 12Z MON. EXPECT OVERNIGHT LOWS TO FALL BACK TO THE MID TO
UPPER 20S WELL INLAND TO AROUND FREEZING ALONG THE S COAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
AS THE SHORT WAVE MOVES OFF THE MID ATLC COAST...QUESTION WILL BE
HOW FAR N WILL THE MAIN PART OF THE MOISTURE WORK N INTO THE
REGION. SHORT RANGE MODELS HAVE BEEN TRENDING A BIT FURTHER N
WITH THIS SYSTEM...BUT NOTING THAT THE H85 TEMPS CONTINUE TO DROP
DURING THE DAY WHICH WOULD INDICATE THAT DRIER AIR WILL WORK IN
ESPECIALLY ACROSS CENTRAL AND NORTHERN AREAS. WILL LIKELY SEE A
PRETTY SHARP CUTOFF FOR THE PRECIP LINE...AND SHOULD BE MAINLY
SNOW. EXPECT TEMPS TO BE RIGHT AROUND FREEZING WHEN THE HEAVIEST
PRECIP MOVES IN...BASED ON WET BULB TEMPS WHERE THE PRECIP FALLS
STEADIEST. HIGHEST QPF AMOUNTS EXPECTED TO BE BETWEEN 0.15 AND
0.35 INCHES ACROSS NE CT/RI/SE MA...WITH LIGHT AMOUNTS UP TO THE
MASS PIKE. SHOULD REMAIN MAINLY DRY N OF THE PIKE.
LOOKS LIKE THE SNOW-TO-LIQUID RATIO SHOULD BE RIGHT AROUND 10 TO
1...SO HAVE SNOWFALL AMOUNTS GENERALLY IN THE 1 TO 3 INCH RANGE
WITH THE HIGHEST AMOUNTS OCCURRING ACROSS SW RI AT THIS POINT.
WITH THE SNOW PROBABILITIES AROUND 50 PERCENT FOR UP TO 4
INCHES...NOT GREATLY CONFIDENT FOR AN ADVISORY AT THIS TIME.
DECIDED TO HOLD OFF ISSUING A WINTER WEATHER ADVISORY FOR SW RI
AND ALLOW THE MID SHIFT TO GET A LOOK AT THE LATEST MODEL TRENDS
TO SEE IF MORE SNOW DOES WORK INTO THE S COAST.
MONDAY NIGHT...
LOW MOVES OFFSHORE RATHER QUICKLY...THOUGH SOME MODELS ARE TRYING
TO LAG PRECIP BACK ACROSS RI/SE MA INTO MON NIGHT. HAVE CARRIED
CHANCE POPS FOR S COASTAL AREAS EARLY...THEN SHOULD PUSH OFFSHORE.
CLEARING SKIES WILL WORK IN FROM N-S OVERNIGHT...BUT SOME CLOUDS
MAY LINGER ACROSS THE OUTER CAPE UNTIL AROUND DAYBREAK. ANOTHER
BATCH OF COLD AIR WORKS IN...BUT EXPECT TEMPS TO BE CLOSE OR JUST
A BIT ABOVE SEASONAL NORMS. OVERNIGHT LOWS FALL BACK TO THE MID
TEENS WELL INLAND TO AROUND 30 ON THE OUTER CAPE AND NANTUCKET.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
* HIGHLIGHTS...
- SEASONABLE AND QUIET TUESDAY
- A SIGNIFICANT WINTER STORM EXPECTED TUESDAY NIGHT INTO WEDNESDAY
- BELOW-NORMAL CONDITIONS AND DRY LATE THIS WEEK
- VERY LOW CONFIDENCE FOR NEXT WEEKEND INTO EARLY NEXT WEEK
* OVERVIEW...
WHILE THERE IS CONFIDENCE IN THE FORECAST THROUGH MOST OF THIS
WEEK...THERE IS VERY LITTLE CONFIDENCE FOR NEXT WEEKEND AND BEYOND.
FORECAST MODEL GUIDANCE EXHIBITS A GREAT DEAL OF VARIANCE IN
HANDLING ENERGY IN VICINITY TO THE GULF OF THE ALASKA...WHICH WILL
HAVE SIGNIFICANT IMPLICATIONS ON DOWNSTREAM OUTCOMES.
* MODEL PREFERENCE...
02/12Z GUIDANCE COMING INTO BETTER AGREEMENT REGARDING THE TRACK OF
A POTENTIALLY SIGNIFICANT WINTER STORM MID WEEK. BETTER DOES NOT
NECESSARILY TRANSLATE TO WELL. MOST OF THE GLOBAL MODELS...
INCLUDING THE GFS...ECMWF AND CANADIAN...NOW KEEP THE TRACK OF A
DEVELOPING SECONDARY LOW PRESSURE SOUTH OF NEW ENGLAND AND MOVE IT
ESSENTIALLY EAST TO WEST ALONG 40N. THE 02/12Z NAM...WHICH IS WRF
BASED...AND 02/15Z SREF...WHICH IS HEAVILY WRF BASED...TRACK THIS
LOW PRESSURE OVER THE CAPE AND ISLANDS WEDNESDAY AFTERNOON.
WHILE THIS IS HIGH PRESSURE RIDGING OVER EASTER CANADA...AS WELL AS
A FAIRLY STRONG COLD AIR DAMMING SIGNATURE ALONG THE EAST SLOPES OF
THE APPALACHIANS...IT IS NOT THE MASSIVE COLD DOME OF A CLOSED OFF
HIGH PRESSURE. AT THIS TIME...WE CONTINUE TO FAVOR THE MORE
SOUTHERN TRACK SUPPORTED BY THE GLOBAL MODELS. THAT SAID...EVEN
THESE MODELS ATTEMPT TO BRING ABOVE FREEZING AIR NORTHWARD INTO
SOUTHERN NEW ENGLAND BY WEDNESDAY AFTERNOON.
* DETAILS...
TUESDAY...
HIGH PRESSURE SWEEPS ACROSS THE REGION. LIGHT AND VARIABLE WINDS.
ANTICIPATING MOSTLY CLEAR AND SEASONABLE CONDITIONS WITH INCREASING
CIRRUS LATE IN THE DAY.
TUESDAY NIGHT INTO WEDNESDAY NIGHT...
JUST ABOUT ALL OF THE MODEL GUIDANCE CONTINUES TO ADVERTISE A
SECONDARY LOW PRESSURE DEVELOPING OFF THE DELMARVA PENINSULA TUESDAY
NIGHT. WHERE THIS LOW PRESSURE MOVES HEADING INTO WEDNESDAY IS
STILL IN QUESTION. HAVE HIGH CONFIDENCE THERE WILL BE MEASURABLE
PRECIPITATION DURING THIS PERIOD...AND THAT ALL OF SOUTHERN NEW
ENGLAND WILL SEE AT LEAST SOME SNOW. ALL THAT REMAINS IS
DETERMINING WHAT TYPE AND HOW MUCH OF EACH TYPE.
GFS MODEL SOUNDINGS SHOW A LAYER BETWEEN 5-10 KFT AROUND FREEZING BY
WEDNESDAY AFTERNOON...MAINLY ACROSS THE SOUTH COAST OF MA AND RI.
DEPENDING ON PRECIPITATION INTENSITY...CANNOT RULE OUT A TRANSITION
TO ALL RAIN ACROSS THE CAPE AND ISLANDS. WILL HAVE TO WAIT AT LEAST
ANOTHER DAY BEFORE THE DETAILS FOR HOW FAR NORTH THE MIXING ZONE
GETS COME INTO BETTER FOCUS. AT THIS POINT...THINKING AREAS EAST OF
I-95 IN MA AND RI WILL BE AT RISK FOR SOME MIXING.
IT DOES APPEAR THE WEDNESDAY MORNING COMMUTE WILL BE IMPACTED BY
SNOW ACROSS MOST OF SOUTHERN NEW ENGLAND. CONDITIONS WITHIN THE
DENDRITIC SNOW GROWTH REGION ARE NOT AS FAVORABLE BY WEDNESDAY
AFTERNOON...SO THE EVENING COMMUTE MIGHT NOT BE AS BAD.
WEDNESDAY NIGHT THROUGH THE END OF THIS WEEK...
SOME LIGHT SNOW LINGERS TO THE REAR OF THE DEPARTING STORM SYSTEM.
OTHERWISE WEST-NORTHWEST FLOW ADVECTS ARCTIC AIR ACROSS THE REGION.
ANTICIPATE BELOW-NORMAL TEMPERATURES.
NEXT WEEKEND...
CONSIDERABLE VARIABILITY IN ENSEMBLE MEMBERS CONCERNING THE HANDLING
OF POLAR- AND PACIFIC-ORIGIN WAVES IN VICINITY OF THE GULF OF
ALASKA. THE UNCERTAINTY IN UPSTREAM TRENDS LENDS TO VERY LITTLE
CONFIDENCE IN WHAT WILL OCCUR DOWNSTREAM. THE ENSEMBLES FROM THE
GFS AND ECMWF...AS WELL AS THEIR OPERATIONAL RUNS...ALL ADVERTISE
ANOTHER POTENTIAL STORM SOMETIME NEXT WEEKEND. THE TIMING VARIES
GREATLY. INTRODUCED A CHANCE OF PRECIPITATION FOR NEXT WEEKEND...
BUT THE DETAILS WILL NEED TO BE WORKED OUT WITH TIME.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY NIGHT/...
HIGH CONFIDENCE TONIGHT AND MONDAY NIGHT. MODERATE CONFIDENCE
MONDAY.
TONIGHT...MAINLY VFR. CIGS LOWERING TO MVFR-IFR ALONG IMMEDIATE S
COAST AND THE ISLANDS AFTER 09Z. LOCAL IFR EARLY ACROSS KACK WHICH
SHOULD IMPROVE BEHIND A COLD FRONT.
MONDAY...EXPECT CONDITIONS TO DETERIORATE ESPECIALLY ACROSS N
CT/RI/SE MA WITH SNOW AND/OR RAIN. EXPECT IFR TO LOCAL LIFR
CIGS/VSBYS POSSIBLE ESPECIALLY FOR THE S COASTAL TERMINALS. N OF
THE MASS PIKE...MAINLY VFR.
MONDAY NIGHT...MAY SEE SOME MVFR CONDITIONS LINGERING ALONG THE S
COAST...THEN WILL IMPROVE. OTHERWISE...MAINLY VFR.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK FOR TUESDAY INTO FRIDAY...MODERATE OVERALL CONFIDENCE.
TUESDAY...HIGH CONFIDENCE.
VFR WITH LIGHT W/NW WINDS.
TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.
DETERIORATING CONDITIONS. IFR-VLIFR WITH SNOW. POTENTIAL FOR FZRA
AND SLEET. INCREASING E/NE FLOW STRONGEST ALONG THE E/SE SHORE.
WEDNESDAY NIGHT INTO FRIDAY...HIGH CONFIDENCE.
IMPROVING VFR. -SN LINGERS INITIALLY FOR SOUTHEAST TERMINALS WITH
POTENTIAL IFR IMPACTS. OTHERWISE CIGS/VSBYS LIFTING. BRISK W/NW
WINDS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY NIGHT/...MODERATE CONFIDENCE.
TONIGHT...
LIGHT SW WINDS WILL SHIFT TO W-NW EARLY AS A COLD FRONT SLOWLY
MOVES OFFSHORE. WINDS WILL BEGIN TO VEER TO N TOWARD DAYBREAK.
MONDAY...
EXPECT WINDS TO SHIFT TO N-NE AS LOW PRES PASSES WELL S OF NEW
ENGLAND. MAY SEE GUSTS UP TO 20 KT AND SEAS MAY REACH 5 FT AGAIN
DURING THE DAY ON THE OUTER WATERS. VSBY RESTRICTIONS IN RAIN
AND/OR SNOW THROUGH MOST OF THE DAY MAINLY S OF BOSTON.
MONDAY NIGHT...
AS THE LOW MOVES OFFSHORE...EXPECT WINDS BACKING TO N. MAY SEE
SOME GUSTS UP TO 25 KT WITH SEAS AROUND 5 FT ON THE OUTER WATERS.
LEFTOVER RAIN OR SNOW MAY REDUCE VISIBILITIES MAINLY BEFORE
MIDNIGHT.
OUTLOOK...TUESDAY THROUGH FRIDAY...
TUESDAY...HIGH CONFIDENCE. RELATIVELY LIGHT WINDS AND SEAS.
TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.
WINTRY MIX OF FOR THE NEAR SHORE WATERS WITH MAINLY RAIN OVER THE
WATERS. BRISK E/NE WINDS WITH GUSTS UP TO 30 KTS TURNING N LATE.
INCREASING WAVE HEIGHTS OVER ALL WATERS. LOW CONFIDENCE ON GALES.
WEDNESDAY NIGHT INTO FRIDAY...HIGH CONFIDENCE.
WINDS AND SEAS DIMINISHING. W/NW FLOW BRISK AT TIMES AND COLDER AIR
BUILDING OVER THE WATERS ALONG WITH WAVE ACTION WILL PRESENT A SMALL
THREAT FOR FREEZING SPRAY.
&&
.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES WILL REMAIN RELATIVELY HIGH MONDAY. THERE IS
THE POSSIBILITY FOR SOME SPLASHOVER DURING THE AFTERNOON HIGH
TIDE ALONG PORTIONS OF THE SOUTH SHORE. WINDS ARE NOT EXPECTED TO
BE VERY STRONG...SO SURGE VALUES OF LESS THAN 1 FOOT ARE EXPECTED.
THIS WILL NEED TO BE MONITORED OVER THE NEXT 24 HOURS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/EVT
NEAR TERM...EVT
SHORT TERM...EVT
LONG TERM...BELK
AVIATION...BELK/EVT
MARINE...BELK/EVT
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1001 PM EST SUN FEB 2 2014
.SYNOPSIS...
THE ACTIVE WEATHER PATTERN CONTINUES THIS WEEK. A LOW PRESSURE
SYSTEM WILL LIFT NE OFF THE MID ATLANTIC COAST JUST SOUTH OF OUR
REGION TOMORROW...BRINGING OUR FIRST ROUND OF WINTRY PRECIPITATION
THIS WEEK. HIGH PRESSURE WILL FOLLOW MONDAY NIGHT AND TUESDAY BEFORE
ANOTHER LOW PRESSURE SYSTEM FROM THE TENNESSEE RIVER VALLEY BRINGS A
WINTRY MIX TO THE REGION TUESDAY NIGHT AND WEDNESDAY. MORE HIGH
PRESSURE IS EXPECTED THURSDAY AND FRIDAY BEFORE ONE MORE LOW MOVES
INTO THE REGION ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
WINTER STORM WARNING EXPANDED NORTH AND WEST AND IF YOU BELIEVE
THE NAM...NOT ENOUGH! WE`LL AWAIT 00Z/3 GFS AND WWD GUIDANCE
BEFORE ANY MORE CHANGES. WE ADDED A TIER OF ADVISORY ON THE
SOUTHERN EDGE OF WARNING AREA BUT AM LESS CONFIDENT THERE OF
ADVY.
MY CONCERN IS PHILLY NORTH TO ALLENTOWN AND NEW BRUNSWICK.
ITS HARD TO BELIEVE THE VOLUME OF 00Z/3 NAM QPF.
SNOW GROWTH LOOKS VERY GOOD (20MB AT -14C) ON THE NAM NOW IN MOST
OF OUR AREA...E PA AND NW NJ CENTERED JUST NW OF I95 AT 12Z MOVES
JUST SE OF I95 AT 15Z AND OUT TO SEA AT 18Z. THIS HAS ME THINKING
A 2-3 HR OF 1/4 S+ IN MANY AREAS DURING THE MORNING. THE GFS NEEDS
TO CONFIRM BUT I AM PREPARED TO SEE THAT DEVELOP.
FOR THOSE QUESTIONING THE WARM THICKNESS AND FCSTG HEAVY SNOW...THAT
BOTHERS ME AS WELL BUT MY INTERPRETATION OF PCPN MICROPHYSICS IS
IF THE COLUMN IS AT OR BELOW ZERO AND SEEDED WITH CRYSTALS FROM
ABV... ANY ZL-/IP- ZR- CHANGES TO SNOW. THE THICKNESS IS HIGH
BECAUSE THE ONCOMING SHORT WAVE IS WEAK (70M HFC) AND HEIGHTS
(850-700 THICKNESS WARM) ARE HIGH LEAVING THE ENTIRE COLUMN AT
MARGINAL JUST SUBZERO IN THE I95 AREA NWD. CIRRUS UPSTREAM IN THE
OHIO AND TENNESSEE VALLEY AS SEEN ON 02Z SATELLITE IMAGERY IS YOUR
SEEDER.
THE DRIVERS FOR THE LIFT APPEAR TO ME TO BE THE 180 KT 250MB JET
STREAK THRU MAINE AT 12Z MONDAY AND THE SW 850 WIND OF 50-55KT IN
W NC AT 12Z MONDAY PUSHING 9C 850 DEWPOINT OUR WAY...WITH
TREMENDOUS CONVERGENCE ALONG THE MASON DIXON LINE AT 12Z MONDAY.
WATCH FOR POSSIBLE POWER PROBLEMS IN THE 6 INCH WET SNOW ZONE DOWN
HERE SOMEWHERE IN S CENTRAL NJ WHERE POWER OUTAGES MAY DEVELOP?
THERE IS INCREASING CONCERN THAT ANY PRECIPITATION BEGINNING AS
RAIN NORTH AND WEST OF PHILADELPHIA BETWEEN 2 AM AND 5 AM WILL
QUICKLY CHANGE TO SNOW WITH POSSIBLY A BRIEF VERY PERIOD OF SLEET
IN THE TRANSITION. LATEST 18Z/2 GFS AND NAM THERMAL PROFILES HAVE
THE ENTIRE VERTICAL THERMAL STRUCTURE BELOW FREEZING BY 11Z! THE
QUESTION ARE THE MODELS TOO COLD TOO FAST? EVEN THE ECMWF HAS AN
ENTIRELY FREEZING COLUMN AT 11Z!
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
**HIGH IMPACT HEAVY SNOW EXPECTED FOR 2 TO 5 HOURS MONDAY MORNING
IN THE WARNING AREA**
18Z NAM/GFS MODEL GUIDANCE IS NOW IN AGREEMENT ON AN AXIS OF LARGE
DENDRITE GROWTH AT 12Z FROM SOUTHEAST PA THROUGH NORTHERN MARYLAND.
IT WILL BE DIFFICULT TO BELIEVE WE DONT SEE A COUPLE OF HOURS OF
1/4S+ IN THE WARNING AREA NEAR OR JUST AFTER DAYBREAK. WHILE THIS
IS MODELED GUIDANCE...WE THINK IT PROBABLE SINCE THE TWO NCEP
PRIMARY MODELS WE USE ARE IN AGREEMENT. THIS AXIS OF HEAVY SNOW
SLIPS EWD PASSING OFF THE COAST BY 1PM.
SNOW WATER EQUIVALENTS MAY ONLY BE 10 TO 1 AND SO WE WONT INFLATE
AMOUNTS... BUT SW RATIO MAY MAKE THIS MORE DIFFICULT TO REMOVE
AFTER THE STORM.
WE CHECKED THE NAM 21Z TEMPS AND THEY ARE BASICALLY WITHIN 2F OF
THE 18Z PREDICTION ALONG AND N OF I80.
SNOW GROWTH LOOKS VERY GOOD (20MB AT -14C) ON THE NAM NOW IN MOST
OF OUR AREA...E PA AND NW NJ CENTERED JUST NW OF I95 AT 12Z MOVES
JUST SE OF I95 AT 15Z AND OUT TO SEA AT 18Z. THIS HAS ME THINKING
A 2-3 HR OF 1/4 S+ IN MANY AREAS DURING THE MORNING. THE GFS NEEDS
TO CONFIRM BUT I AM PREPARED TO SEE THAT DEVELOP.
FOR THOSE QUESTIONING THE WARM THICKNESS AND FCSTG HEAVY SNOW...THAT
BOTHERS ME AS WELL BUT MY INTERPRETATION OF PCPN MICROPHYSICS IS
IF THE COLUMN IS AT OR BELOW ZERO AND SEEDED WITH CRYSTALS FROM
ABV... ANY ZL-/IP- ZR- CHANGES TO SNOW. THE THICKNESS IS HIGH
BECAUSE THE ONCOMING SHORT WAVE IS WEAK (70M HFC) AND HEIGHTS
(850-700 THICKNESS WARM) ARE HIGH LEAVING THE ENTIRE COLUMN AT
MARGINAL JUST SUBZERO IN THE I95 AREA NWD. CIRRUS UPSTREAM IN THE
OHIO AND TENNESSEE VALLEY AS SEEN ON 02Z SATELLITE IMAGERY IS YOUR
SEEDER.
THE DRIVERS FOR THE LIFT APPEAR TO ME TO BE THE 180 KT 250MB JET
STREAK THRU MAINE AT 12Z MONDAY AND THE SW 850 WIND OF 50-55KT IN
W NC AT 12Z MONDAY PUSHING 9C 850 DEWPOINT OUR WAY...WITH
TREMENDOUS CONVERGENCE ALONG THE MASON DIXON LINE AT 12Z MONDAY.
WATCH FOR POSSIBLE POWER PROBLEMS IN THE 6 INCH WET SNOW ZONE DOWN
HERE SOMEWHERE IN S CENTRAL NJ WHERE POWER OUTAGES MAY DEVELOP?
LATEST 21Z/2 RAP HAS 3 NEW INCHES OF SNOW BETWEEN 9Z AND 15Z IN THE
POCONOS AND 2 INCHES THROUGHOUT NNJ THOUGH ONLY 1 INCH NEAR I95 IN
PHILADELPHIA. IF THE STRONG FGEN DOES NOT MATERIALIZE AS NOW MODELED
THEN SNOW TOTALS WILL BE MARKEDLY LESS BUT AS IT STANDS NOW...
WHILE THE OVERALL SNOW EVENT WILL NOT BE CONSIDERED ANYTHING SPECIAL...
ITS ACCUMULATION WITHIN A RELATIVELY SHORT PERIOD OF TIME MAKES THIS
MUCH HIGHER IMPACT.
FROM THE EARLIER DISCUSSION BELOW
THE BIGGEST ISSUE WITH THIS SYSTEM, AS MENTIONED ABOVE, IS THE
LOW-LEVEL TEMPERATURES, INCLUDING THE BOUNDARY LAYER. THE FRONT
THAT WILL INCH THROUGH TONIGHT DOES NOT APPEAR TO BE A TRUE ARCTIC
FRONT AS TEMPERATURES BEHIND IT HAVE NOT PLUMMETED AS FAST AS THEY
WOULD OTHERWISE.
THE NAM HAS BEEN SLOWLY MOVING ITS BETTER FGEN FORCING FURTHER TO
THE SOUTH THE PAST COUPLE OF RUNS WHILE THE GFS KEEPS IT NEARBY,
MOSTLY OVER PHL. BUFKIT SOUNDINGS SHOW THE BEST SNOW GROWTH HAPPENS
LATE MORNING WHEN HELP FROM THE JET DYNAMICS PROPELS THE VVS
STRONGER AND THE BEST OMEGA MOVES IN PLACE. THIS IS WHEN THE BETTER
ACCUMULATING SNOWFALL WILL OCCUR AND THERE COULD BE SOME RATES
AROUND AN 1 OR 2 AN HOUR. THAT BEING SAID, THIS SYSTEM IS NOT
LOLLY-GAGGING DOWN TO FIRST, AS IT IT RAPIDLY PULLING AWAY SO ANY
BANDING THAT TAKE PLACE WILL BE TRANSIENT. WILL HAVE TO KEEP AN EYE
ON HOW THE RAIN/SNOW LINE PROGRESSES TONIGHT AND TOMORROW MORNING
AND WE COULD COME CLOSE TO WARNING AMOUNTS OUTSIDE THE CURRENT
WARNING AREAS.
THE SYSTEM MOVES OFFSHORE BY THE AFTERNOON HOURS AND PULLS TOWARDS
THE EAST-NORTHEAST PUTTING AN END TO THE SNOW BY THE LATE AFTERNOON
HOURS. TEMPERATURES SHOULD REMAIN RELATIVELY STEADY UNDER THE
INITIAL SNOWFALL AND THEN DROP ONCE THE HEAVIER QPF KICKS IN. THE
DAYTIME HIGH SHOULD BE REACHED SHORTLY AFTER MIDNIGHT TONIGHT AND
THE LOW SHOULD OCCUR LATE TOMORROW EVENING.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIODS ARE STILL FOCUSED ON TWO MAIN EVENTS.
FIRST...THE LOW LIFTING NE TUESDAY NIGHT INTO WEDNESDAY. THE BIGGEST
QUESTION WITH THIS SYSTEM WILL BE THE TRACK OF THE LOW. IF THE TRACK
IS JUST SOUTH OF THE REGION...ON SHORE FLOW IN THE COLD SECTOR COULD
RESULT IN WIDESPREAD ICING. IF THE TRACK IS BISECTING OUR REGION AS
INDICATED BY THE GFS...THE ICING CONCERNS WILL BE PRIMARILY CONFINED
TO THE HIGHER TERRAIN IN EASTERN PA...WITH MOSTLY RAIN EXPECTED FROM
THE DELAWARE RIVER VALLEY AND EAST. THIS WILL BE HARD TO RESOLVE
WITH MUCH CONFIDENCE AT THIS TIME...ESPECIALLY GIVEN HOW POORLY SOME
MODELS INITIALIZED TODAY WITH FEATURES IN THE NEAR TERM. MODEL
SOUNDINGS FROM BOTH SOLUTIONS WITH THE TRACK OF THE LOW SHOW THE
MOIST LAYER TOO SHALLOW FOR ANY SIGNIFICANT SNOW GROWTH REGION IN
THE CLOUD...WITH THE POSSIBLE EXCEPTION OF THE POCONOS. THE MAIN
COLD FRONT LOOKS TO PUSH THROUGH THE REGION AFTER MOST OF THE
PRECIPITATION HAS ENDED.
BY THURSDAY...FLOW ALOFT TRANSITIONS TO ZONAL AS A SURFACE RIDGE
BUILDS IN FROM THE WEST. IN THE WAKE OF THE COLD FRONT
HOWEVER...TEMPERATURES WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL.
THE LATTER PART OF THE LONG TERM PERIOD WILL BEGIN RELATIVELY QUIET,
BUT ON THE COLD SIDE, AS HIGH PRESSURE EXTENDS ACROSS THE REGION
FROM THURSDAY NIGHT THROUGH THE DAYTIME FRIDAY. FOR THE MOST PART,
WE USED WPC TEMP GUIDANCE FOR THIS TIME FRAME, WITH A FEW LOCAL
ADJUSTMENTS. MINIMUM TEMPERATURES THURSDAY NIGHT ARE EXPECTED TO
MOSTLY BE IN THE TEENS ACROSS THE FORECAST AREA, WITH HIGH
TEMPERATURES FRIDAY MAINLY RANGING FROM THE MID 20S NORTH TO THE MID
30S SOUTH.
INTO NEXT WEEKEND, THE OVERALL PATTERN LOOKS MORE ACTIVE, WITH
ANOTHER STORM SYSTEM AFFECTING THE REGION AS HIGH PRESSURE MOVES
AWAY TO THE NORTHEAST. THERE ARE SOME NOTICEABLE DIFFERENCES IN
MODEL SOLUTIONS FOR NEXT WEEKEND, INCLUDING BETWEEN THE ECMWF AND
GFS. IN GENERAL, WE FAVORED THE ECMWF A LITTLE MORE AT THIS TIME,
BUT WE HOPE TO SEE MORE CONSISTENCY IN MODEL SOLUTIONS AS WE GET
CLOSER IN TIME TO REFINE THE DETAILS RELATED TO THIS STORM SYSTEM.
DEPENDING ON STORM TRACK AND TIMING, THIS LOOKS TO BE ANOTHER MIXED
PRECIPITATION EVENT FOR SATURDAY INTO SUNDAY, CREATING THE POTENTIAL
FOR HAZARDOUS TRAVEL.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE CEILINGS WILL GRADUALLY LOWER TO MVFR FROM WEST TO EAST ACROSS
THE REGION AS LOW PRESSURE APPROACHES FROM THE SOUTHWEST, WITH
KABE AND KRDG LOWERING BY LATE THIS EVENING AND THE REMAINDER OF
THE TERMINALS LOWERING DURING THE OVERNIGHT. THE ONSET OF
PRECIPITATION IS EXPECTED AROUND MIDNIGHT OR WITHIN A FEW HOURS OF
MIDNIGHT, BEGINNING BRIEFLY AS LIGHT RAIN BEFORE BECOMING A
RAIN/SNOW MIX. THE COLUMN LOOKS TO BE COLD ENOUGH IN RECENT MODEL
RUNS TO PROVIDE A PRETTY QUICK CHANGE-OVER TO SNOW FOR KABE/KRDG
AND THEN ALSO FOR THE KPHL METRO TERMINALS, MOST LIKELY PRIOR TO
DAYBREAK. ONCE THE CHANGE-OVER TO SNOW OCCURS, CIGS/VSBYS LIKELY
DROP TO IFR, AND WE HAVE INCLUDED A WINDOW MONDAY MORNING OF 1/4
TO 1/2 MILE VSBYS IN +SN OR SN, AS MODEL GUIDANCE IS SHOWING THE
POTENTIAL FOR A PERIOD OF MODERATE TO HEAVY SNOW. OVERALL, WINDS
WILL BECOME MORE NORTHERLY TO NORTH-NORTHEAST, REMAINING IN THE 5
TO 10 KNOT RANGE. THE PRIMARY IMPACTS WILL BE THROUGH MIDDAY TO
EARLY AFTERNOON...WITH PRECIPITATION EXITING THE REGION LATE MONDAY
AFTERNOON. IMPROVEMENT TO VFR IS EXPECTED DURING MONDAY EVENING.
PLOWING OPERATIONS PROBABLY NEEDED WITH SUBSTANTIAL AIR TRAVEL DELAYS
IF NOT A POSSIBLE BRIEF CLOSING OF RUNWAYS IS EXPECTED FROM KPHL
KILG THROUGH KTTN NORTHWESTWARD DURING MID MORNING MONDAY.
OUTLOOK...
TUESDAY...MAINLY VFR THROUGH THE DAY. MVFR CONDITIONS WITH RA FOR
KPHL...KPNE...KTTN...KILG...KMIV...AND KACY WILL BE POSSIBLE TUESDAY
NIGHT INTO WEDNESDAY. AT KRDG AND KABE...EXPECT FZRA REDUCING
VISIBILITIES AND CEILINGS TO MVFR...OR POSSIBLY IFR.
WEDNESDAY...MAINLY MVFR WITH THE PRECIPITATION WHICH WILL BE ENDING
LATE IN THE DAY...THEN VFR. FZRA SHOULD TRANSITION TO RA MID DAY
WEDNESDAY AT KRDG AND KABE.
THURSDAY...PRIMARILY VFR EXPECTED.
FRIDAY...PRIMARILY VFR EXPECTED.
&&
.MARINE...
BASED ON RECENT MODEL DATA, BUFKIT SOUNDINGS, AND SOME WAVEWATCH
GUIDANCE, WE DECIDED TO RAISE A SMALL CRAFT ADVISORY FOR OUR
SOUTHERN ATLANTIC COASTAL WATERS, FROM GREAT EGG INLET SOUTH TO
FENWICK ISLAND, AND ALSO FOR THE SOUTHERN DELAWARE BAY. WIND GUSTS
AND SEAS MAY BE MARGINAL, BUT WE DO EXPECT TO SEE SOME GUSTS IN
THE 25 TO 30 KNOT RANGE, WITH SEAS ALONG THE COASTAL WATERS
NEARING 5 FEET. FOR THE REMAINDER OF OUR COASTAL WATERS NORTH OF
GREAT EGG INLET TO SANDY HOOK, WE EXPECT WIND GUSTS TO BE
PRIMARILY UNDER 25 KNOTS, WITH SEAS IN THE 3 TO 4 FOOT RANGE
THROUGH THE MONDAY AND MONDAY NIGHT PERIODS.
OUTLOOK...
TUESDAY...SUB-SCA CONDITIONS EXPECTED.
WEDNESDAY...WINDS AND SEAS EXPECTED TO REACH SCA CONDITIONS AS A LOW
MOVES TOWARDS THE REGION.
THURSDAY...SUB-SCA CONDITIONS EXPECTED.
FRIDAY...SUB-SCA CONDITIONS EXPECTED.
&&
.HYDROLOGY...
CURRENT RIVER ICE CONDITIONS...ALL RIVERS IN THE HSA REPORT AT LEAST
SOME ICE COVER, WITH MANY COMPLETELY ICE COVERED. MANY GAGE READINGS
SHOW ICE EFFECTS.
ICE JAMS...SOLID ICE COVER IS NOT NECESSARILY AN ICE JAM. AN ICE JAM
IS DEFINED AS A RESTRICTION. IF WATER IF FLOWING UNDERNEATH THE ICE,
AND NOT CAUSING THE WATER TO BACK UP, THE ICE COVER IS NOT CONSIDERED
A JAM.
ICE BREAK UP...THE TWO MAIN FACTORS THAT QUICKLY CAUSE ICE TO BREAK
UP ARE RUNOFF AND TEMPERATURES, WITH RUNOFF BEING A MORE SIGNIFICANT
FACTOR. WHEN WATER LEVELS RISE, IT LIFTS THE ICE, FRACTURES IT, AND
DISLODGES IT FROM THE RIVER BANKS.
SO LET`S TAKE A LOOK AT TEMPERATURES AND RAINFALL(WHICH LEADS TO
RUNOFF).
TEMPERATURES...
MONDAY...LOWS IN THE HIGH TEENS TO AROUND 30. HIGHS IN THE UPPER
20S TO UPPER 30S.
TUESDAY...LOWS IN THE TEENS TO MID 20S. HIGHS IN THE 30S TO LOW
40S.
WEDNESDAY...LOWS IN THE MID 20S TO MID 30S. HIGHS IN THE 30S
AND 40S.
RAINFALL...THERE IS A CHANCE OF PRECIPITATION (MOSTLY RAIN)
TUESDAY NIGHT INTO WEDNESDAY. IT COULD START OFF AS SNOW AND ICE
FOR THE NORTHERN HALF OF HSA. EARLY QPF VALUES LATE TUESDAY INTO
WEDNESDAY ARE IN EXCESS OF 1.00 INCH WHICH WOULD CAUSE SIGNIFICANT
RUNOFF.
FUTURE ICE CONDITIONS...WHILE ICE RELEASES AND POSSIBLE JAMS ARE
HARD TO PREDICT, WE FEEL WITHOUT ANY SIGNIFICANT RUNOFF THIS WEEKEND,
THE WARMER DAYTIME TEMPERATURES ALONE WILL NOT BREAK UP THE ICE.
INSTEAD, WE FEEL THE ICE WILL SOFTEN AND MELT.
AT THIS TIME, THERE IS MORE OF A CONCERN FOR THE MIDDLE OF NEXT WEEK
AS DAYTIME HIGHS ARE FORECAST TO CLIMB ABOVE FREEZING AND A HEAVIER
RAINFALL IS EXPECTED TO MOVE INTO THE AREA.
STILL, BECAUSE RIVER ICE IS UNPREDICTABLE, PLEASE CONTINUE TO
MONITOR YOUR NEARBY STREAMS AND RIVERS AND NOTIFY THE APPROPRIATE
PERSONNEL IF YOU SHOULD SEE ANY FLOODING AND/OR AN ICE JAM OCCURRING.
&&
.CLIMATE...
THE CLIS FOR 2/2/14 WILL HAVE THE 12Z SNOW DEPTH ADDED AT 130AM EST
MONDAY.
RECORD DAILY SNOWFALL: WHILE NOT FORECAST ...THERE IS A CHANCE
ONE OR 2 OF THESE VALUES "MAY" BE APPROACHED TO WITHIN 1 INCH.
FEBRUARY 3
KABE 7.3 1961
KACY 4.2 1961
KPHL 8.0 1886
KILG 6.7 1961
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY FROM 4 AM TO 5 PM EST MONDAY FOR
PAZ054-055-060>062-105.
WINTER STORM WARNING FROM 5 AM TO 5 PM EST MONDAY FOR PAZ070-
071-101>104-106.
NJ...WINTER WEATHER ADVISORY FROM 4 AM TO 5 PM EST MONDAY FOR
NJZ001-007>010.
WINTER WEATHER ADVISORY FROM 9 AM TO 5 PM EST MONDAY FOR
NJZ021-022.
WINTER STORM WARNING FROM 5 AM TO 5 PM EST MONDAY FOR NJZ012-
013-015>020-026-027.
WINTER WEATHER ADVISORY FROM 7 AM TO 5 PM EST MONDAY FOR
NJZ014.
DE...WINTER WEATHER ADVISORY FROM 9 AM TO 5 PM EST MONDAY FOR
DEZ002.
WINTER STORM WARNING FROM 5 AM TO 5 PM EST MONDAY FOR DEZ001.
MD...WINTER WEATHER ADVISORY FROM 9 AM TO 5 PM EST MONDAY FOR
MDZ012-015.
WINTER STORM WARNING FROM 5 AM TO 5 PM EST MONDAY FOR MDZ008.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM MONDAY TO 7 AM EST TUESDAY FOR
ANZ453>455.
SMALL CRAFT ADVISORY FROM 7 AM MONDAY TO 1 AM EST TUESDAY FOR
ANZ431.
&&
$$
SYNOPSIS...JOHNSON
NEAR TERM...DRAG
SHORT TERM...DRAG/HEAVENER
LONG TERM...JOHNSON/KLINE
AVIATION...JOHNSON/KLINE
MARINE...JOHNSON/KLINE
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
928 PM EST SUN FEB 2 2014
.SYNOPSIS...
THE ACTIVE WEATHER PATTERN CONTINUES THIS WEEK. A LOW PRESSURE
SYSTEM WILL LIFT NE OFF THE MID ATLANTIC COAST JUST SOUTH OF OUR
REGION TOMORROW...BRINGING OUR FIRST ROUND OF WINTRY PRECIPITATION
THIS WEEK. HIGH PRESSURE WILL FOLLOW MONDAY NIGHT AND TUESDAY BEFORE
ANOTHER LOW PRESSURE SYSTEM FROM THE TENNESSEE RIVER VALLEY BRINGS A
WINTRY MIX TO THE REGION TUESDAY NIGHT AND WEDNESDAY. MORE HIGH
PRESSURE IS EXPECTED THURSDAY AND FRIDAY BEFORE ONE MORE LOW MOVES
INTO THE REGION ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
WINTER STORM WARNING EXPANDED NORTH AND WEST AND IF YOU BELIEVE
THE NAM...NOT ENOUGH! WE`LL AWAIT 00Z/3 GFS AND WWD GUIDANCE
BEFORE ANY MORE CHANGES. WE ADDED A TIER OF ADVISORY ON THE
SOUTHERN EDGE OF WARNING AREA BUT AM LESS CONFIDENT THERE OF
ADVY.
MY CONCERN IS PHILLY NORTH TO ALLENTOWN AND NEW BRUNSWICK.
ITS HARD TO BELIEVE THE VOLUME OF 00Z/3 NAM QPF.
SNOW GROWTH LOOKS VERY GOOD (20MB AT -14C) ON THE NAM NOW IN MOST
OF OUR AREA...E PA AND NW NJ CENTERED JUST NW OF I95 AT 12Z MOVES
JUST SE OF I95 AT 15Z AND OUT TO SEA AT 18Z. THIS HAS ME THINKING
A 2-3 HR OF 1/4 S+ IN MANY AREAS DURING THE MORNING. THE GFS NEEDS
TO CONFIRM BUT I AM PREPARED TO SEE THAT DEVELOP.
FOR THOSE QUESTIONING THE WARM THICKNESS AND FCSTG HEAVY SNOW...THAT
BOTHERS ME AS WELL BUT MY INTERPRETATION OF PCPN MICROPHYSICS IS
IF THE COLUMN IS AT OR BELOW ZERO AND SEEDED WITH CRYSTALS FROM
ABV... ANY ZL-/IP- ZR- CHANGES TO SNOW. THE THICKNESS IS HIGH
BECAUSE THE ONCOMING SHORT WAVE IS WEAK (70M HFC) AND HEIGHTS
(850-700 THICKNESS WARM) ARE HIGH LEAVING THE ENTIRE COLUMN AT
MARGINAL JUST SUBZERO IN THE I95 AREA NWD. CIRRUS UPSTREAM IN THE
OHIO AND TENNESSEE VALLEY AS SEEN ON 02Z SATELLITE IMAGERY IS YOUR
SEEDER.
THE DRIVERS FOR THE LIFT APPEAR TO ME TO BE THE 180 KT 250MB JET
STREAK THRU MAINE AT 12Z MONDAY AND THE SW 850 WIND OF 50-55KT IN
W NC AT 12Z MONDAY PUSHING 9C 850 DEWPOINT OUR WAY...WITH
TREMENDOUS CONVERGENCE ALONG THE MASON DIXON LINE AT 12Z MONDAY.
WATCH FOR POSSIBLE POWER PROBLEMS IN THE 6 INCH WET SNOW ZONE DOWN
HERE SOMEWHERE IN S CENTRAL NJ WHERE POWER OUTAGES MAY DEVELOP?
THERE IS INCREASING CONCERN THAT ANY PRECIPITATION BEGINNING AS
RAIN NORTH AND WEST OF PHILADELPHIA BETWEEN 2 AM AND 5 AM WILL
QUICKLY CHANGE TO SNOW WITH POSSIBLY A BRIEF VERY PERIOD OF SLEET
IN THE TRANSITION. LATEST 18Z/2 GFS AND NAM THERMAL PROFILES HAVE
THE ENTIRE VERTICAL THERMAL STRUCTURE BELOW FREEZING BY 11Z! THE
QUESTION ARE THE MODELS TOO COLD TOO FAST? EVEN THE ECMWF HAS AN
ENTIRELY FREEZING COLUMN AT 11Z!
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
**HIGH IMPACT HEAVY SNOW EXPECTED FOR 2 TO 5 HOURS MONDAY MORNING
IN THE WARNING AREA**
18Z NAM/GFS MODEL GUIDANCE IS NOW IN AGREEMENT ON AN AXIS OF LARGE
DENDRITE GROWTH AT 12Z FROM SOUTHEAST PA THROUGH NORTHERN MARYLAND.
IT WILL BE DIFFICULT TO BELIEVE WE DONT SEE A COUPLE OF HOURS OF
1/4S+ IN THE WARNING AREA NEAR OR JUST AFTER DAYBREAK. WHILE THIS
IS MODELED GUIDANCE...WE THINK IT PROBABLE SINCE THE TWO NCEP
PRIMARY MODELS WE USE ARE IN AGREEMENT. THIS AXIS OF HEAVY SNOW
SLIPS EWD PASSING OFF THE COAST BY 1PM.
SNOW WATER EQUIVALENTS MAY ONLY BE 10 TO 1 AND SO WE WONT INFLATE
AMOUNTS... BUT SW RATIO MAY MAKE THIS MORE DIFFICULT TO REMOVE
AFTER THE STORM.
WE CHECKED THE NAM 21Z TEMPS AND THEY ARE BASICALLY WITHIN 2F OF
THE 18Z PREDICTION ALONG AND N OF I80.
SNOW GROWTH LOOKS VERY GOOD (20MB AT -14C) ON THE NAM NOW IN MOST
OF OUR AREA...E PA AND NW NJ CENTERED JUST NW OF I95 AT 12Z MOVES
JUST SE OF I95 AT 15Z AND OUT TO SEA AT 18Z. THIS HAS ME THINKING
A 2-3 HR OF 1/4 S+ IN MANY AREAS DURING THE MORNING. THE GFS NEEDS
TO CONFIRM BUT I AM PREPARED TO SEE THAT DEVELOP.
FOR THOSE QUESTIONING THE WARM THICKNESS AND FCSTG HEAVY SNOW...THAT
BOTHERS ME AS WELL BUT MY INTERPRETATION OF PCPN MICROPHYSICS IS
IF THE COLUMN IS AT OR BELOW ZERO AND SEEDED WITH CRYSTALS FROM
ABV... ANY ZL-/IP- ZR- CHANGES TO SNOW. THE THICKNESS IS HIGH
BECAUSE THE ONCOMING SHORT WAVE IS WEAK (70M HFC) AND HEIGHTS
(850-700 THICKNESS WARM) ARE HIGH LEAVING THE ENTIRE COLUMN AT
MARGINAL JUST SUBZERO IN THE I95 AREA NWD. CIRRUS UPSTREAM IN THE
OHIO AND TENNESSEE VALLEY AS SEEN ON 02Z SATELLITE IMAGERY IS YOUR
SEEDER.
THE DRIVERS FOR THE LIFT APPEAR TO ME TO BE THE 180 KT 250MB JET
STREAK THRU MAINE AT 12Z MONDAY AND THE SW 850 WIND OF 50-55KT IN
W NC AT 12Z MONDAY PUSHING 9C 850 DEWPOINT OUR WAY...WITH
TREMENDOUS CONVERGENCE ALONG THE MASON DIXON LINE AT 12Z MONDAY.
WATCH FOR POSSIBLE POWER PROBLEMS IN THE 6 INCH WET SNOW ZONE DOWN
HERE SOMEWHERE IN S CENTRAL NJ WHERE POWER OUTAGES MAY DEVELOP?
LATEST 21Z/2 RAP HAS 3 NEW INCHES OF SNOW BETWEEN 9Z AND 15Z IN THE
POCONOS AND 2 INCHES THROUGHOUT NNJ THOUGH ONLY 1 INCH NEAR I95 IN
PHILADELPHIA. IF THE STRONG FGEN DOES NOT MATERIALIZE AS NOW MODELED
THEN SNOW TOTALS WILL BE MARKEDLY LESS BUT AS IT STANDS NOW...
WHILE THE OVERALL SNOW EVENT WILL NOT BE CONSIDERED ANYTHING SPECIAL...
ITS ACCUMULATION WITHIN A RELATIVELY SHORT PERIOD OF TIME MAKES THIS
MUCH HIGHER IMPACT.
FROM THE EARLIER DISCUSSION BELOW
THE BIGGEST ISSUE WITH THIS SYSTEM, AS MENTIONED ABOVE, IS THE
LOW-LEVEL TEMPERATURES, INCLUDING THE BOUNDARY LAYER. THE FRONT
THAT WILL INCH THROUGH TONIGHT DOES NOT APPEAR TO BE A TRUE ARCTIC
FRONT AS TEMPERATURES BEHIND IT HAVE NOT PLUMMETED AS FAST AS THEY
WOULD OTHERWISE.
THE NAM HAS BEEN SLOWLY MOVING ITS BETTER FGEN FORCING FURTHER TO
THE SOUTH THE PAST COUPLE OF RUNS WHILE THE GFS KEEPS IT NEARBY,
MOSTLY OVER PHL. BUFKIT SOUNDINGS SHOW THE BEST SNOW GROWTH HAPPENS
LATE MORNING WHEN HELP FROM THE JET DYNAMICS PROPELS THE VVS
STRONGER AND THE BEST OMEGA MOVES IN PLACE. THIS IS WHEN THE BETTER
ACCUMULATING SNOWFALL WILL OCCUR AND THERE COULD BE SOME RATES
AROUND AN 1 OR 2 AN HOUR. THAT BEING SAID, THIS SYSTEM IS NOT
LOLLY-GAGGING DOWN TO FIRST, AS IT IT RAPIDLY PULLING AWAY SO ANY
BANDING THAT TAKE PLACE WILL BE TRANSIENT. WILL HAVE TO KEEP AN EYE
ON HOW THE RAIN/SNOW LINE PROGRESSES TONIGHT AND TOMORROW MORNING
AND WE COULD COME CLOSE TO WARNING AMOUNTS OUTSIDE THE CURRENT
WARNING AREAS.
THE SYSTEM MOVES OFFSHORE BY THE AFTERNOON HOURS AND PULLS TOWARDS
THE EAST-NORTHEAST PUTTING AN END TO THE SNOW BY THE LATE AFTERNOON
HOURS. TEMPERATURES SHOULD REMAIN RELATIVELY STEADY UNDER THE
INITIAL SNOWFALL AND THEN DROP ONCE THE HEAVIER QPF KICKS IN. THE
DAYTIME HIGH SHOULD BE REACHED SHORTLY AFTER MIDNIGHT TONIGHT AND
THE LOW SHOULD OCCUR LATE TOMORROW EVENING.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIODS ARE STILL FOCUSED ON TWO MAIN EVENTS.
FIRST...THE LOW LIFTING NE TUESDAY NIGHT INTO WEDNESDAY. THE BIGGEST
QUESTION WITH THIS SYSTEM WILL BE THE TRACK OF THE LOW. IF THE TRACK
IS JUST SOUTH OF THE REGION...ON SHORE FLOW IN THE COLD SECTOR COULD
RESULT IN WIDESPREAD ICING. IF THE TRACK IS BISECTING OUR REGION AS
INDICATED BY THE GFS...THE ICING CONCERNS WILL BE PRIMARILY CONFINED
TO THE HIGHER TERRAIN IN EASTERN PA...WITH MOSTLY RAIN EXPECTED FROM
THE DELAWARE RIVER VALLEY AND EAST. THIS WILL BE HARD TO RESOLVE
WITH MUCH CONFIDENCE AT THIS TIME...ESPECIALLY GIVEN HOW POORLY SOME
MODELS INITIALIZED TODAY WITH FEATURES IN THE NEAR TERM. MODEL
SOUNDINGS FROM BOTH SOLUTIONS WITH THE TRACK OF THE LOW SHOW THE
MOIST LAYER TOO SHALLOW FOR ANY SIGNIFICANT SNOW GROWTH REGION IN
THE CLOUD...WITH THE POSSIBLE EXCEPTION OF THE POCONOS. THE MAIN
COLD FRONT LOOKS TO PUSH THROUGH THE REGION AFTER MOST OF THE
PRECIPITATION HAS ENDED.
BY THURSDAY...FLOW ALOFT TRANSITIONS TO ZONAL AS A SURFACE RIDGE
BUILDS IN FROM THE WEST. IN THE WAKE OF THE COLD FRONT
HOWEVER...TEMPERATURES WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL.
THE LATTER PART OF THE LONG TERM PERIOD WILL BEGIN RELATIVELY QUIET,
BUT ON THE COLD SIDE, AS HIGH PRESSURE EXTENDS ACROSS THE REGION
FROM THURSDAY NIGHT THROUGH THE DAYTIME FRIDAY. FOR THE MOST PART,
WE USED WPC TEMP GUIDANCE FOR THIS TIME FRAME, WITH A FEW LOCAL
ADJUSTMENTS. MINIMUM TEMPERATURES THURSDAY NIGHT ARE EXPECTED TO
MOSTLY BE IN THE TEENS ACROSS THE FORECAST AREA, WITH HIGH
TEMPERATURES FRIDAY MAINLY RANGING FROM THE MID 20S NORTH TO THE MID
30S SOUTH.
INTO NEXT WEEKEND, THE OVERALL PATTERN LOOKS MORE ACTIVE, WITH
ANOTHER STORM SYSTEM AFFECTING THE REGION AS HIGH PRESSURE MOVES
AWAY TO THE NORTHEAST. THERE ARE SOME NOTICEABLE DIFFERENCES IN
MODEL SOLUTIONS FOR NEXT WEEKEND, INCLUDING BETWEEN THE ECMWF AND
GFS. IN GENERAL, WE FAVORED THE ECMWF A LITTLE MORE AT THIS TIME,
BUT WE HOPE TO SEE MORE CONSISTENCY IN MODEL SOLUTIONS AS WE GET
CLOSER IN TIME TO REFINE THE DETAILS RELATED TO THIS STORM SYSTEM.
DEPENDING ON STORM TRACK AND TIMING, THIS LOOKS TO BE ANOTHER MIXED
PRECIPITATION EVENT FOR SATURDAY INTO SUNDAY, CREATING THE POTENTIAL
FOR HAZARDOUS TRAVEL.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE CEILINGS WILL GRADUALLY LOWER TO MVFR FROM WEST TO EAST ACROSS
THE REGION AS LOW PRESSURE APPROACHES FROM THE SOUTHWEST, WITH
KABE AND KRDG LOWERING BY LATE THIS EVENING AND THE REMAINDER OF
THE TERMINALS LOWERING DURING THE OVERNIGHT. THE ONSET OF
PRECIPITATION IS EXPECTED AROUND MIDNIGHT OR WITHIN A FEW HOURS OF
MIDNIGHT, BEGINNING BRIEFLY AS LIGHT RAIN BEFORE BECOMING A
RAIN/SNOW MIX. THE COLUMN LOOKS TO BE COLD ENOUGH IN RECENT MODEL
RUNS TO PROVIDE A PRETTY QUICK CHANGE-OVER TO SNOW FOR KABE/KRDG
AND THEN ALSO FOR THE KPHL METRO TERMINALS, MOST LIKELY PRIOR TO
DAYBREAK. ONCE THE CHANGE-OVER TO SNOW OCCURS, CIGS/VSBYS LIKELY
DROP TO IFR, AND WE HAVE INCLUDED A WINDOW MONDAY MORNING OF 1/4
TO 1/2 MILE VSBYS IN +SN OR SN, AS MODEL GUIDANCE IS SHOWING THE
POTENTIAL FOR A PERIOD OF MODERATE TO HEAVY SNOW. OVERALL, WINDS
WILL BECOME MORE NORTHERLY TO NORTH-NORTHEAST, REMAINING IN THE 5
TO 10 KNOT RANGE. THE PRIMARY IMPACTS WILL BE THROUGH MIDDAY TO
EARLY AFTERNOON...WITH PRECIPITATION EXITING THE REGION LATE MONDAY
AFTERNOON. IMPROVEMENT TO VFR IS EXPECTED DURING MONDAY EVENING.
PLOWING OPERATIONS PROBABLY NEEDED WITH SUBSTANTIAL AIR TRAVEL DELAYS
IF NOT A POSSIBLE BRIEF CLOSING OF RUNWAYS IS EXPECTED FROM KPHL
KILG THROUGH KTTN NORTHWESTWARD DURING MID MORNING MONDAY.
OUTLOOK...
TUESDAY...MAINLY VFR THROUGH THE DAY. MVFR CONDITIONS WITH RA FOR
KPHL...KPNE...KTTN...KILG...KMIV...AND KACY WILL BE POSSIBLE TUESDAY
NIGHT INTO WEDNESDAY. AT KRDG AND KABE...EXPECT FZRA REDUCING
VISIBILITIES AND CEILINGS TO MVFR...OR POSSIBLY IFR.
WEDNESDAY...MAINLY MVFR WITH THE PRECIPITATION WHICH WILL BE ENDING
LATE IN THE DAY...THEN VFR. FZRA SHOULD TRANSITION TO RA MID DAY
WEDNESDAY AT KRDG AND KABE.
THURSDAY...PRIMARILY VFR EXPECTED.
FRIDAY...PRIMARILY VFR EXPECTED.
&&
.MARINE...
THE CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
CRITERIA THROUGH TONIGHT. A WEAKENING COLD FRONT WILL BE ARRIVING
THROUGH TODAY, HOWEVER IT SHOULD TEND TO STALL FOR A TIME AS IT
NEARS THE COAST. THIS WILL RESULT IN THE SOUTHERLY FLOW TURNING
MORE WESTERLY TOWARD EVENING. THERE WILL BE SOME FOG EARLY THIS
MORNING, HOWEVER MOST OF IT SHOULD BE CLOSER TO THE COAST AND
MAINLY FROM THE COAST OF NORTHERN OCEAN COUNTY ON NORTHWARD. THE
FLOW WILL THEN SHIFT TO THE NORTHWEST AND NORTH TONIGHT AS OUR
NEXT STORM SYSTEM APPROACHES. SEAS GENERALLY RUNNING AROUND 3 FEET
ON THE OCEAN AND 1 TO 2 FEET ON DELAWARE BAY.
OUTLOOK...
TUESDAY...SUB-SCA CONDITIONS EXPECTED.
WEDNESDAY...WINDS AND SEAS EXPECTED TO REACH SCA CONDITIONS AS A LOW
MOVES TOWARDS THE REGION.
THURSDAY...SUB-SCA CONDITIONS EXPECTED.
FRIDAY...SUB-SCA CONDITIONS EXPECTED.
&&
.HYDROLOGY...
CURRENT RIVER ICE CONDITIONS...ALL RIVERS IN THE HSA REPORT AT LEAST
SOME ICE COVER, WITH MANY COMPLETELY ICE COVERED. MANY GAGE READINGS
SHOW ICE EFFECTS.
ICE JAMS...SOLID ICE COVER IS NOT NECESSARILY AN ICE JAM. AN ICE JAM
IS DEFINED AS A RESTRICTION. IF WATER IF FLOWING UNDERNEATH THE ICE,
AND NOT CAUSING THE WATER TO BACK UP, THE ICE COVER IS NOT CONSIDERED
A JAM.
ICE BREAK UP...THE TWO MAIN FACTORS THAT QUICKLY CAUSE ICE TO BREAK
UP ARE RUNOFF AND TEMPERATURES, WITH RUNOFF BEING A MORE SIGNIFICANT
FACTOR. WHEN WATER LEVELS RISE, IT LIFTS THE ICE, FRACTURES IT, AND
DISLODGES IT FROM THE RIVER BANKS.
SO LET`S TAKE A LOOK AT TEMPERATURES AND RAINFALL(WHICH LEADS TO
RUNOFF).
TEMPERATURES...
MONDAY...LOWS IN THE HIGH TEENS TO AROUND 30. HIGHS IN THE UPPER
20S TO UPPER 30S.
TUESDAY...LOWS IN THE TEENS TO MID 20S. HIGHS IN THE 30S TO LOW
40S.
WEDNESDAY...LOWS IN THE MID 20S TO MID 30S. HIGHS IN THE 30S
AND 40S.
RAINFALL...THERE IS A CHANCE OF PRECIPITATION (MOSTLY RAIN)
TUESDAY NIGHT INTO WEDNESDAY. IT COULD START OFF AS SNOW AND ICE
FOR THE NORTHERN HALF OF HSA. EARLY QPF VALUES LATE TUESDAY INTO
WEDNESDAY ARE IN EXCESS OF 1.00 INCH WHICH WOULD CAUSE SIGNIFICANT
RUNOFF.
FUTURE ICE CONDITIONS...WHILE ICE RELEASES AND POSSIBLE JAMS ARE
HARD TO PREDICT, WE FEEL WITHOUT ANY SIGNIFICANT RUNOFF THIS WEEKEND,
THE WARMER DAYTIME TEMPERATURES ALONE WILL NOT BREAK UP THE ICE.
INSTEAD, WE FEEL THE ICE WILL SOFTEN AND MELT.
AT THIS TIME, THERE IS MORE OF A CONCERN FOR THE MIDDLE OF NEXT WEEK
AS DAYTIME HIGHS ARE FORECAST TO CLIMB ABOVE FREEZING AND A HEAVIER
RAINFALL IS EXPECTED TO MOVE INTO THE AREA.
STILL, BECAUSE RIVER ICE IS UNPREDICTABLE, PLEASE CONTINUE TO
MONITOR YOUR NEARBY STREAMS AND RIVERS AND NOTIFY THE APPROPRIATE
PERSONNEL IF YOU SHOULD SEE ANY FLOODING AND/OR AN ICE JAM OCCURRING.
&&
.CLIMATE...
THE CLIS FOR 2/2/14 WILL HAVE THE 12Z SNOW DEPTH ADDED AT 130AM EST
MONDAY.
RECORD DAILY SNOWFALL: WHILE NOT FORECAST ...THERE IS A CHANCE
ONE OR 2 OF THESE VALUES "MAY" BE APPROACHED TO WITHIN 1 INCH.
FEBRUARY 3
KABE 7.3 1961
KACY 4.2 1961
KPHL 8.0 1886
KILG 6.7 1961
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY FROM 4 AM TO 5 PM EST MONDAY FOR
PAZ054-055-060>062-105.
WINTER STORM WARNING FROM 5 AM TO 5 PM EST MONDAY FOR PAZ070-
071-101>104-106.
NJ...WINTER WEATHER ADVISORY FROM 4 AM TO 5 PM EST MONDAY FOR
NJZ001-007>010.
WINTER STORM WARNING FROM 5 AM TO 5 PM EST MONDAY FOR NJZ012-
013-015>020-026-027.
WINTER WEATHER ADVISORY FROM 9 AM TO 5 PM EST MONDAY FOR
NJZ021-022.
WINTER WEATHER ADVISORY FROM 7 AM TO 5 PM EST MONDAY FOR
NJZ014.
DE...WINTER STORM WARNING FROM 5 AM TO 5 PM EST MONDAY FOR DEZ001.
WINTER WEATHER ADVISORY FROM 9 AM TO 5 PM EST MONDAY FOR
DEZ002.
MD...WINTER STORM WARNING FROM 5 AM TO 5 PM EST MONDAY FOR MDZ008.
WINTER WEATHER ADVISORY FROM 9 AM TO 5 PM EST MONDAY FOR
MDZ012-015.
MARINE...NONE.
&&
$$
SYNOPSIS...JOHNSON
NEAR TERM...DRAG 928P
SHORT TERM...DRAG/HEAVENER 92P
LONG TERM...JOHNSON/KLINE
AVIATION...JOHNSON/KLINE 928P
MARINE...HEAVENER/JOHNSON
HYDROLOGY...
CLIMATE...928P
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
802 PM EST SUN FEB 2 2014
.SYNOPSIS...
THE ACTIVE WEATHER PATTERN CONTINUES THIS WEEK. A LOW PRESSURE
SYSTEM WILL LIFT NE OFF THE MID ATLANTIC COAST JUST SOUTH OF OUR
REGION TOMORROW...BRINGING OUR FIRST ROUND OF WINTRY PRECIPITATION
THIS WEEK. HIGH PRESSURE WILL FOLLOW MONDAY NIGHT AND TUESDAY BEFORE
ANOTHER LOW PRESSURE SYSTEM FROM THE TENNESSEE RIVER VALLEY BRINGS A
WINTRY MIX TO THE REGION TUESDAY NIGHT AND WEDNESDAY. MORE HIGH
PRESSURE IS EXPECTED THURSDAY AND FRIDAY BEFORE ONE MORE LOW MOVES
INTO THE REGION ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
WINTER STORM WARNING IN AFFECT FOR THE PHILADELPHIA METRO AREA WITH
WINTER WEATHER ADVISORIES IN PLACE FURTHER NORTH AND WEST OF THIS
THROUGH TOMORROW EVENING. MORE IN THE SHORT TERM SECTION BELOW.
555 PM NOTE: WE ARE REVIEWING GUIDANCE FOR A POTENTIAL SLIGHT
UPGRADE IN AMOUNTS AND SLIGHT EXPANSION NORTHWESTWARD IN THE
WARNING CONFIGURATION AND POSSIBLY ADDING A LAYER OF ADVY ALONG
THE SOUTH BORDER OF THE WARNING. WE`LL HAVE WHATEVER CHANGES WE
ARE CONFIDENT OF...COMPLETED BY 8 PM. THE ONE ZONE WE ARE VERY
CONFIDENT OF UPGRADING TO A WARNING IS WESTERN CHESTER COUNTY TO
BRIDGE WITH THE STATE COLLEGE LATEST UPDATE FOR LANCASTER COUNTY.
THE PSEUDO-ARCTIC FRONT TO OUR WEST-NORTHWEST WILL CONTINUE TO
SLOWLY SLIDE THROUGH THE REGION TODAY PROVIDING SOME CHANCES FOR
SHOWERS, MOSTLY LIQUID AS THERMAL PROFILES CONTINUE TO SHOW LOW-
LEVEL WARMING TAKING PLACE. THE MAJORITY OF THE ENERGY ASSOCIATED
WITH THE FRONT CONTINUES TO REMAIN ACROSS OUR NORTHWESTERN ZONES
AND THIS IS WHERE WE WILL CONTINUE WITH THE HIGHER CHANCES FOR
RAIN TONIGHT THEN TRANSITIONING TO A MIX LATER THIS EVENING AS
SOME COLD AIR STARTS TO SEEP INTO THE REGION.
THERE IS INCREASING CONCERN THAT ANY PRECIPITATION BEGINNING AS RAIN
NORTH AND WEST OF PHILADELPHIA BETWEEN 2 AM AND 5 AM WILL QUICKLY
CHANGE TO SNOW WITH POSSIBLY A BRIEF VERY PERIOD OF SLEET IN THE
TRANSITION. LATEST 18Z/2 GFS AND NAM THERMAL PROFILES HAVE THE
ENTIRE VERTICAL THERMAL STRUCTURE BELOW FREEZING BY 10Z! THE
QUESTION ARE THE MODELS TOO COLD TOO FAST? EVEN THE ECMWF HAS AN
ENTIRELY FREEZING COLUMN AT 11Z!
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
**HIGH IMPACT HEAVY SNOW EXPECTED FOR 2 TO 5 HOURS MONDAY MORNING
IN THE WARNING AREA**
18Z NAM/GFS MODEL GUIDANCE IS NOW IN AGREEMENT ON AN AXIS OF LARGE
DENDRITE GROWTH AT 12Z FROM SOUTHEAST PA THROUGH NORTHERN MARYLAND.
IT WILL BE DIFFICULT TO BELIEVE WE DONT SEE A COUPLE OF HOURS OF
1/4S+ IN THE WARNING AREA NEAR OR JUST AFTER DAYBREAK. WHILE THIS
IS MODELED GUIDANCE...WE THINK IT PROBABLE SINCE THE TWO NCEP
PRIMARY MODELS WE USE ARE IN AGREEMENT. THIS AXIS OF HEAVY SNOW
SLIPS EWD PASSING OFF THE COAST BY 1PM.
SNOW WATER EQUIVALENTS MAY ONLY BE 10 TO 1 AND SO WE WONT INFLATE
AMOUNTS... BUT SW RATIO MAY MAKE THIS MORE DIFFICULT TO REMOVE
AFTER THE STORM.
WE CHECKED THE NAM 21Z TEMPS AND THEY ARE BASICALLY WITHIN 2F OF
THE 18Z PREDICTION ALONG AND N OF I80.
LATEST 21Z/2 RAP HAS 3 NEW INCHES OF SNOW BETWEEN 9Z AND 15Z IN THE
POCONOS AND 2 INCHES THROUGHOUT NNJ THOUGH ONLY 1 INCH NEAR I95 IN
PHILADELPHIA. IF THE STRONG FGEN DOES NOT MATERIALIZE AS NOW MODELED
THEN SNOW TOTALS WILL BE MARKEDLY LESS BUT AS IT STANDS NOW...
WHILE THE OVERALL SNOW EVENT WILL NOT BE CONSIDERED ANYTHING SPECIAL...
ITS ACCUMULATION WITHIN A RELATIVELY SHORT PERIOD OF TIME MAKES THIS
MUCH HIGHER IMPACT.
FROM THE EARLIER DISCUSSION BELOW
THE OPEN/STABLE WAVE CONTINUES TO TRUCK ALONG THE STALLING
FRONTAL BOUNDARY TO THE SOUTH OF THE REGION TOMORROW MORNING.
THE NEW 12Z MODELS ARE IN AND THE UPPER AIR INITIALIZATION SHOWS
THEY ARE ALL A TAD DEEPER WITH THE SHORTWAVE ACROSS THE TEXAS
PANHANDLE AND COLDER IN THE LOW-LEVELS UPSTREAM...THIS WILL CAUSE A
GREATER UNCERTAINTY TO PTYPE TRANSITION KEEPING THE COLDER AIR
FURTHER WEST FOR A LONGER PERIOD OF TIME. FROM THE WORDS OF A FAMOUS
WEATHERMAN, "IT`S GON` RAIN, SLEET, SNOW"!, JUST A MATTER OF
LOCATION AND TIMING NOW.
ALL THE MODELS TAKE A SIMILAR TRACK WITH THE MID-LEVEL FEATURE AND
THE SURFACE INFLECTION. FOR THE MOST PART THE NEW GUIDANCE PAINTS A
PRETTY HEFTY AMOUNT OF QPF ACROSS THE REGION WITH A BAND OF NEARLY
EIGHT TENTHS FROM PHILLY SOUTHWARD, WHERE WE GET CLOSER TO AN INCH.
THE BIGGEST ISSUE WITH THIS SYSTEM, AS MENTIONED ABOVE, IS THE
LOW-LEVEL TEMPERATURES, INCLUDING THE BOUNDARY LAYER. THE FRONT THAT
WILL INCH THROUGH TONIGHT DOES NOT APPEAR TO BE A TRUE ARCTIC FRONT
AS TEMPERATURES BEHIND IT HAVE NOT PLUMMETED AS FAST AS THEY WOULD
OTHERWISE.
THE NAM HAS BEEN SLOWLY MOVING ITS BETTER FGEN FORCING FURTHER TO
THE SOUTH THE PAST COUPLE OF RUNS WHILE THE GFS KEEPS IT NEARBY,
MOSTLY OVER PHL. BUFKIT SOUNDINGS SHOW THE BEST SNOW GROWTH HAPPENS
LATE MORNING WHEN HELP FROM THE JET DYNAMICS PROPELS THE VVS
STRONGER AND THE BEST OMEGA MOVES IN PLACE. THIS IS WHEN THE BETTER
ACCUMULATING SNOWFALL WILL OCCUR AND THERE COULD BE SOME RATES
AROUND AN 1 OR 2 AN HOUR. THAT BEING SAID, THIS SYSTEM IS NOT
LOLLY-GAGGING DOWN TO FIRST, AS IT IT RAPIDLY PULLING AWAY SO ANY
BANDING THAT TAKE PLACE WILL BE TRANSIENT. WILL HAVE TO KEEP AN EYE
ON HOW THE RAIN/SNOW LINE PROGRESSES TONIGHT AND TOMORROW MORNING
AND WE COULD COME CLOSE TO WARNING AMOUNTS OUTSIDE THE CURRENT
WARNING AREAS.
THE SYSTEM MOVES OFFSHORE BY THE AFTERNOON HOURS AND PULLS TOWARDS
THE EAST-NORTHEAST PUTTING AN END TO THE SNOW BY THE LATE AFTERNOON
HOURS. TEMPERATURES SHOULD REMAIN RELATIVELY STEADY UNDER THE
INITIAL SNOWFALL AND THEN DROP ONCE THE HEAVIER QPF KICKS IN. THE
DAYTIME HIGH SHOULD BE REACHED SHORTLY AFTER MIDNIGHT TONIGHT AND
THE LOW SHOULD OCCUR LATE TOMORROW EVENING.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIODS ARE STILL FOCUSED ON TWO MAIN EVENTS.
FIRST...THE LOW LIFTING NE TUESDAY NIGHT INTO WEDNESDAY. THE BIGGEST
QUESTION WITH THIS SYSTEM WILL BE THE TRACK OF THE LOW. IF THE TRACK
IS JUST SOUTH OF THE REGION...ON SHORE FLOW IN THE COLD SECTOR COULD
RESULT IN WIDESPREAD ICING. IF THE TRACK IS BISECTING OUR REGION AS
INDICATED BY THE GFS...THE ICING CONCERNS WILL BE PRIMARILY CONFINED
TO THE HIGHER TERRAIN IN EASTERN PA...WITH MOSTLY RAIN EXPECTED FROM
THE DELAWARE RIVER VALLEY AND EAST. THIS WILL BE HARD TO RESOLVE
WITH MUCH CONFIDENCE AT THIS TIME...ESPECIALLY GIVEN HOW POORLY SOME
MODELS INITIALIZED TODAY WITH FEATURES IN THE NEAR TERM. MODEL
SOUNDINGS FROM BOTH SOLUTIONS WITH THE TRACK OF THE LOW SHOW THE
MOIST LAYER TOO SHALLOW FOR ANY SIGNIFICANT SNOW GROWTH REGION IN
THE CLOUD...WITH THE POSSIBLE EXCEPTION OF THE POCONOS. THE MAIN
COLD FRONT LOOKS TO PUSH THROUGH THE REGION AFTER MOST OF THE
PRECIPITATION HAS ENDED.
BY THURSDAY...FLOW ALOFT TRANSITIONS TO ZONAL AS A SURFACE RIDGE
BUILDS IN FROM THE WEST. IN THE WAKE OF THE COLD FRONT
HOWEVER...TEMPERATURES WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL.
THE LATTER PART OF THE LONG TERM PERIOD WILL BEGIN RELATIVELY QUIET,
BUT ON THE COLD SIDE, AS HIGH PRESSURE EXTENDS ACROSS THE REGION
FROM THURSDAY NIGHT THROUGH THE DAYTIME FRIDAY. FOR THE MOST PART,
WE USED WPC TEMP GUIDANCE FOR THIS TIME FRAME, WITH A FEW LOCAL
ADJUSTMENTS. MINIMUM TEMPERATURES THURSDAY NIGHT ARE EXPECTED TO
MOSTLY BE IN THE TEENS ACROSS THE FORECAST AREA, WITH HIGH
TEMPERATURES FRIDAY MAINLY RANGING FROM THE MID 20S NORTH TO THE MID
30S SOUTH.
INTO NEXT WEEKEND, THE OVERALL PATTERN LOOKS MORE ACTIVE, WITH
ANOTHER STORM SYSTEM AFFECTING THE REGION AS HIGH PRESSURE MOVES
AWAY TO THE NORTHEAST. THERE ARE SOME NOTICEABLE DIFFERENCES IN
MODEL SOLUTIONS FOR NEXT WEEKEND, INCLUDING BETWEEN THE ECMWF AND
GFS. IN GENERAL, WE FAVORED THE ECMWF A LITTLE MORE AT THIS TIME,
BUT WE HOPE TO SEE MORE CONSISTENCY IN MODEL SOLUTIONS AS WE GET
CLOSER IN TIME TO REFINE THE DETAILS RELATED TO THIS STORM SYSTEM.
DEPENDING ON STORM TRACK AND TIMING, THIS LOOKS TO BE ANOTHER MIXED
PRECIPITATION EVENT FOR SATURDAY INTO SUNDAY, CREATING THE POTENTIAL
FOR HAZARDOUS TRAVEL.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE CEILINGS WILL GRADUALLY LOWER TO MVFR FROM WEST TO EAST ACROSS
THE REGION AS LOW PRESSURE APPROACHES FROM THE SOUTHWEST, WITH
KABE AND KRDG LOWERING BY LATE THIS EVENING AND THE REMAINDER OF
THE TERMINALS LOWERING DURING THE OVERNIGHT. THE ONSET OF
PRECIPITATION IS EXPECTED AROUND MIDNIGHT OR WITHIN A FEW HOURS OF
MIDNIGHT, BEGINNING BRIEFLY AS LIGHT RAIN BEFORE BECOMING A
RAIN/SNOW MIX. THE COLUMN LOOKS TO BE COLD ENOUGH IN RECENT MODEL
RUNS TO PROVIDE A PRETTY QUICK CHANGE-OVER TO SNOW FOR KABE/KRDG
AND THEN ALSO FOR THE KPHL METRO TERMINALS, MOST LIKELY PRIOR TO
DAYBREAK. ONCE THE CHANGE-OVER TO SNOW OCCURS, CIGS/VSBYS LIKELY
DROP TO IFR, AND WE HAVE INCLUDED A WINDOW MONDAY MORNING OF 1/4
TO 1/2 MILE VSBYS IN +SN OR SN, AS MODEL GUIDANCE IS SHOWING THE
POTENTIAL FOR A PERIOD OF MODERATE TO HEAVY SNOW. OVERALL, WINDS
WILL BECOME MORE NORTHERLY TO NORTH-NORTHEAST, REMAINING IN THE 5
TO 10 KNOT RANGE. THE PRIMARY IMPACTS WILL BE THROUGH MIDDAY TO
EARLY AFTERNOON...WITH PRECIPITATION EXITING THE REGION LATE MONDAY
AFTERNOON. IMPROVEMENT TO VFR IS EXPECTED DURING MONDAY EVENING.
OUTLOOK...
TUESDAY...MAINLY VFR THROUGH THE DAY. MVFR CONDITIONS WITH RA FOR
KPHL...KPNE...KTTN...KILG...KMIV...AND KACY WILL BE POSSIBLE TUESDAY
NIGHT INTO WEDNESDAY. AT KRDG AND KABE...EXPECT FZRA REDUCING
VISIBILITIES AND CEILINGS TO MVFR...OR POSSIBLY IFR.
WEDNESDAY...MAINLY MVFR WITH THE PRECIPITATION WHICH WILL BE ENDING
LATE IN THE DAY...THEN VFR. FZRA SHOULD TRANSITION TO RA MID DAY
WEDNESDAY AT KRDG AND KABE.
THURSDAY...PRIMARILY VFR EXPECTED.
FRIDAY...PRIMARILY VFR EXPECTED.
&&
.MARINE...
THE CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
CRITERIA THROUGH TONIGHT. A WEAKENING COLD FRONT WILL BE ARRIVING
THROUGH TODAY, HOWEVER IT SHOULD TEND TO STALL FOR A TIME AS IT
NEARS THE COAST. THIS WILL RESULT IN THE SOUTHERLY FLOW TURNING
MORE WESTERLY TOWARD EVENING. THERE WILL BE SOME FOG EARLY THIS
MORNING, HOWEVER MOST OF IT SHOULD BE CLOSER TO THE COAST AND
MAINLY FROM THE COAST OF NORTHERN OCEAN COUNTY ON NORTHWARD. THE
FLOW WILL THEN SHIFT TO THE NORTHWEST AND NORTH TONIGHT AS OUR
NEXT STORM SYSTEM APPROACHES. SEAS GENERALLY RUNNING AROUND 3 FEET
ON THE OCEAN AND 1 TO 2 FEET ON DELAWARE BAY.
OUTLOOK...
TUESDAY...SUB-SCA CONDITIONS EXPECTED.
WEDNESDAY...WINDS AND SEAS EXPECTED TO REACH SCA CONDITIONS AS A LOW
MOVES TOWARDS THE REGION.
THURSDAY...SUB-SCA CONDITIONS EXPECTED.
FRIDAY...SUB-SCA CONDITIONS EXPECTED.
&&
.HYDROLOGY...
CURRENT RIVER ICE CONDITIONS...ALL RIVERS IN THE HSA REPORT AT LEAST
SOME ICE COVER, WITH MANY COMPLETELY ICE COVERED. MANY GAGE READINGS
SHOW ICE EFFECTS.
ICE JAMS...SOLID ICE COVER IS NOT NECESSARILY AN ICE JAM. AN ICE JAM
IS DEFINED AS A RESTRICTION. IF WATER IF FLOWING UNDERNEATH THE ICE,
AND NOT CAUSING THE WATER TO BACK UP, THE ICE COVER IS NOT CONSIDERED
A JAM.
ICE BREAK UP...THE TWO MAIN FACTORS THAT QUICKLY CAUSE ICE TO BREAK
UP ARE RUNOFF AND TEMPERATURES, WITH RUNOFF BEING A MORE SIGNIFICANT
FACTOR. WHEN WATER LEVELS RISE, IT LIFTS THE ICE, FRACTURES IT, AND
DISLODGES IT FROM THE RIVER BANKS.
SO LET`S TAKE A LOOK AT TEMPERATURES AND RAINFALL(WHICH LEADS TO
RUNOFF).
TEMPERATURES...
MONDAY...LOWS IN THE HIGH TEENS TO AROUND 30. HIGHS IN THE UPPER
20S TO UPPER 30S.
TUESDAY...LOWS IN THE TEENS TO MID 20S. HIGHS IN THE 30S TO LOW
40S.
WEDNESDAY...LOWS IN THE MID 20S TO MID 30S. HIGHS IN THE 30S
AND 40S.
RAINFALL...THERE IS A CHANCE OF PRECIPITATION (MOSTLY RAIN)
TUESDAY NIGHT INTO WEDNESDAY. IT COULD START OFF AS SNOW AND ICE
FOR THE NORTHERN HALF OF HSA. EARLY QPF VALUES LATE TUESDAY INTO
WEDNESDAY ARE IN EXCESS OF 1.00 INCH WHICH WOULD CAUSE SIGNIFICANT
RUNOFF.
FUTURE ICE CONDITIONS...WHILE ICE RELEASES AND POSSIBLE JAMS ARE
HARD TO PREDICT, WE FEEL WITHOUT ANY SIGNIFICANT RUNOFF THIS WEEKEND,
THE WARMER DAYTIME TEMPERATURES ALONE WILL NOT BREAK UP THE ICE.
INSTEAD, WE FEEL THE ICE WILL SOFTEN AND MELT.
AT THIS TIME, THERE IS MORE OF A CONCERN FOR THE MIDDLE OF NEXT WEEK
AS DAYTIME HIGHS ARE FORECAST TO CLIMB ABOVE FREEZING AND A HEAVIER
RAINFALL IS EXPECTED TO MOVE INTO THE AREA.
STILL, BECAUSE RIVER ICE IS UNPREDICTABLE, PLEASE CONTINUE TO
MONITOR YOUR NEARBY STREAMS AND RIVERS AND NOTIFY THE APPROPRIATE
PERSONNEL IF YOU SHOULD SEE ANY FLOODING AND/OR AN ICE JAM OCCURRING.
&&
.CLIMATE...
THE CLIS FOR 2/2/14 WILL HAVE THE 12Z SNOW DEPTH ADDED AT 130AM EST
MONDAY.
RECORD DAILY SNOWFALL: WHILE NOT FORECAST ...THERE IS A SMALL CHANCE
ONE OR 2 OF THESE VALUES "MAY" BE APPROACHED TO WITHIN 1 INCH.
FEBRUARY 3
KABE 7.3 1961
KACY 4.2 1961
KPHL 8.0 1886
KILG 6.7 1961
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY FROM 6 AM TO 7 PM EST MONDAY FOR
PAZ054-055-060>062-101-103-105.
WINTER STORM WARNING FROM 6 AM TO 7 PM EST MONDAY FOR PAZ070-
071-102-104-106.
NJ...WINTER WEATHER ADVISORY FROM 6 AM TO 7 PM EST MONDAY FOR
NJZ001-007>010-012>015.
WINTER STORM WARNING FROM 6 AM TO 7 PM EST MONDAY FOR
NJZ016>020-026-027.
DE...WINTER STORM WARNING FROM 6 AM TO 7 PM EST MONDAY FOR DEZ001.
MD...WINTER STORM WARNING FROM 6 AM TO 7 PM EST MONDAY FOR MDZ008.
MARINE...NONE.
&&
$$
SYNOPSIS...JOHNSON
NEAR TERM...DRAG/HEAVENER
SHORT TERM...DRAG/HEAVENER
LONG TERM...JOHNSON/KLINE
AVIATION...JOHNSON/KLINE
MARINE...HEAVENER/JOHNSON
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
144 PM CST SAT FEB 1 2014
.DISCUSSION...
1053 AM CST
WE WILL BE CANCELING HEADLINES ACROSS FAR NORTHERN ILLINOIS AS IT
APPEARS THE MAIN AXIS OF PRECIPITATION WILL BE MAINLY CONFINED ALONG
AND SOUTH OF A CHICAGO TO MENDOTA LINE FOR THE REST OF THE DAY.
WE ARE STILL LIKELY TO SEE SOME MODERATE PRECIP RATES AT
TIMES...ESPECIALLY SOUTH THROUGH THE DAY AS FGEN CONTINUES TO
PROVIDE AMPLE FORCING FOR ASCENT. FREEZING RAIN CONTINUES TO BE THE
MAIN CONCERN FROM PNT...THROUGH IKK TO VPZ AND POINTS SOUTH. STILL
APPEARS THAT ICE ACCUMULATIONS COULD REACH UP AROUND A QUARTER INCH
ACROSS THESE AREAS. TEMPERATURES REMAIN RIGHT AT OR JUST ABOVE
FREEZING ACROSS FAR SOUTHEASTERN SECTIONS OF THE AREA...SO IT IS
LIKELY THAT AT LEAST SOME MINOR ICE ACCUMULATIONS WILL OCCUR HERE AS
WELL OVER THE NEXT COUPLE HOURS.
COLDER AIR WILL FILTER BACK IN ACROSS EAST CENTRAL ILLINOIS AND
NORTHWESTERN INDIANA BY MID TO LATE AFTERNOON AND THIS SHOULD ALLOW
THE WINTER MIX TO CHANCE BACK OVER TO SNOW. SOME MINOR SNOW
ACCUMULATIONS ARE POSSIBLE BEFORE THE SNOW ENDS THERE.
IN THE CHICAGO METRO AREA...THERE WILL CONTINUE TO BE ADDITIONAL
PERIODS OF LIGHT TO MODERATE SNOW THROUGH AT MID TO LATE
AFTERNOON...AND THIS COULD PRODUCE ANOTHER INCH OR TWO OF SNOW.
THIS COMBINED WITH AMOUNTS OF 3 TO 5 INCHES ON THE GROUND ALREADY
COULD PUSH AMOUNTS CLOSE TO 6 INCHES. THEREFORE...I WILL LEAVE THE
WARNING IN PLACE FOR MOST OF THE CHICAGO AREA MINUS THE NORTHERN
AND FAR WESTERN SUBURBS.
KJB
//PREV DISCUSSION...
333 AM CST
THIS MORNING...
WINTER STORM CONTINUES TO DEVELOP EARLY THIS MORNING AFTER A LULL
OVERNIGHT...HOWEVER STRONG WARM AIR ADVECTION UPSTREAM OF THE
FORECAST AREA COUPLED WITH A POTENT LLVL FORCING IS GENERATING A
NARROW CHANNEL OF INTENSE PRECIPITATION.
MUCH OF THE OVERNIGHT HOURS HAD A LULL...LARGELY IN PART TO THE
QUASI-STATIONARY SFC RIDGE JUST NORTH OF THE FORECAST AREA. THIS
RESULTED IN A CONTINUED FEED OF DRIER LLVL AIR INTO NORTHERN
IL/NORTHWEST IN. THE LEADING EDGE OF THE COLDER CLOUDS CONTINUED TO
BE ERODED AS IT PUSHED NORTHEAST INTO THE PESKY ANTI-CYCLONIC
FEATURE. MEANWHILE WELL UPSTREAM OF THE FORECAST AREA IN EASTERN
KANSAS/NORTHEAST OKLAHOMA...WHERE STRONG FGEN FORCING AND
CYCLOGENESIS WAS TAKING PLACE...A NARROW CHANNEL OF INTENSE
PRECIPITATION WAS NOTED FROM SFC OBS INDICATING M1/4SM VSBYS WITH
+SN. BY 9Z THIS MORNING THIS AREA OF PRECIP HAD QUICKLY EXPANDED
NORTHEAST...AS A LARGE SLUG OF WATER VAPOR PUSHED INTO NORTHEAST
IA/NORTHWEST IL/NORTHEAST MO. LOCAL RADAR NOTED STEADILY INCREASING
RETURNS BY 9Z OVER THE FORECAST AREA...WITH A HANDFUL OF POINTS
ALONG AND WEST OF A STERLING TO PONTIAC LINE BEGINNING TO REPORT LGT
SNOW.
THEN THE CHALLENGE BEGINS FOR MID-MORNING THRU MIDDAY...WITH RESPECT
TO HOW MUCH FREEZING RAIN THE SOUTHERN PORTIONS OF THE CWFA RECEIVE.
THEN TO THE NORTH OF THIS...HOW MUCH SNOW. DUE TO THE PESKY SFC
RIDGE TO THE NORTH...THE BETTER PUSH OF WARMER LLVL AIR HAS REMAINED
WELL SOUTH ACROSS SOUTHERN IL WHERE SFC TEMPS ARE HOVERING EARLY
THIS MORNING ARND 32 DEGREES. HOWEVER EXPECT WITH THE RAPID GROWTH
AND EXPANSION OF THE MODERATE SNOW OVERSPREADING NORTHERN IL BY
11-14Z...TEMPS SOUTH OF LASALLE TO KANKAKEE WILL BEGIN TO WARM INTO
THE UPR 20S.
MOST GUIDANCE MEMBERS HAVE BACKED OFF ON THE QPF TOTALS FOR
TDY...LARGELY DUE TO THE LULL OVERNIGHT AND WITH THE WAVE AT 850MB
REMAINING OPEN AND PROGRESSIVE...THIS APPEARS TO MAKE SOME SENSE.
HOWEVER WITH THE IMPRESSIVE DYNAMICS GOING ON UPSTREAM EARLY THIS
MORNING...IT IS DIFFICULT TO MAKE TOO MANY CHANGES. THE ONE AREA
THAT CONFIDENCE IS SLIGHTLY HIGHER ON IS THAT SNOWFALL TOTALS MAY
FALL JUST UNDER EARLIER THINKING. HAVE HELD ONTO THE CURRENT WINTER
STORM WARNING AND ADVISORIES...BUT FEEL IT WILL BE MORE IN LINE WITH
THE HIGHEST SNOWFALL TOTALS AROUND 5 TO 8". LOCAL HI-RES WRF OUTPUT
SUGGESTS THE AXIS OF BETTER QPF AND SNOWFALL WOULD FALL FURTHER
SOUTH THEN CURRENT THINKING...OR ALONG A LASALLE/PONTIAC TO SOUTH
CHICAGO/MICHIGAN CITY LINE. COBB OUTPUT FOR A HANDFUL OF POINTS
INDICATE GENERALLY AROUND 5 TO 7".
AS FOR FREEZING RAIN...THE STRONG WARM AIR ADVECTION NOTED EARLY
THIS MORNING UPSTREAM OF THE FORECAST AREA...IS SHOWING UP IN THE
MODEL SOUNDINGS ACROSS THE SOUTHERN CWFA. HOWEVER PROFILES ONLY HUG
THE 0 DEG ISOTHERM...SUGGESTING THAT PERHAPS ONLY A PARTIAL MELT
WILL OCCUR. GIVEN THE STRONG FORCING THAT IS ANTICIPATED...WILL
CONTINUE TO OPT FOR A FULL MELT IN THE SOUTHERN CWFA WITH P-TYPE
CHANGING TO FZRA OR A PERIOD OF RA LATER THIS MORNING THRU EARLY
AFTN.
THE BULK OF THE SNOW WILL BE SLOWER TO END THIS AFTN FROM WEST TO
EAST...AS HIGH PRESSURE ACROSS THE NORTHERN PLAINS DRIFTS EAST
THROUGHOUT THE DAY. COULD SEE THE NEED FOR LGT SNOW LINGERING ACROSS
THE WESTERN CWFA INTO THE LATE AFTN HOURS BEFORE ENDING. TEMPS FOR
THE BULK OF THE CWFA WILL WARM INTO THE MID/UPR 20S...WITH AREAS
ALONG AND SOUTH OF LASALLE TO CHICAGO SEEING TEMPS ARND 30 TO THE
LOWER 30S. CLOSER TO GIBSON CITY TO DEMOTTE TEMPS MAY WARM INTO THE
UPR 30S.
BEACHLER
SUNDAY THROUGH MONDAY...
SURFACE HIGH WILL TRANSLATE EASTWARD FROM THE CENTRAL PLAINS ACROSS
THE MID MISSISSIPPI VALLEY WHICH IN COMBINATION WITH SHORTWAVE
RIDGING ALOFT WILL PROVIDE DRY ALBEIT COOL WEATHER THROUGH THE
PERIOD. H85 TEMPS BOTTOM OUT AROUND -12C AND EXPECT SURFACE TEMPS TO
ONLY BE ABLE TO WARM INTO THE MID TEENS SUNDAY AFTERNOON. SUNDAY
NIGHT THE RIDGE AXIS WILL MOVE OVERHEAD AND SKIES SHOULD BE MOSTLY
CLEAR SETTING UP A FAVORABLE RADIATIONAL COOLING SETUP RESULTING IN
LOWS ONCE AGAIN FALLING BELOW ZERO FOR MUCH OF THE CWA. SURFACE HIGH
STAYS OVER THE AREA ON MONDAY BUT OUR NEXT SYSTEM DEVELOPING OVER
THE SOUTHERN PLAINS WILL BEGIN TO LIFT THE H85 BAROCLINIC ZONE
TOWARDS THE AREA. EXPECT CLOUD COVER TO INCREASE ON MONDAY AS
ISENTROPIC ASCENT OVERSPREADS THE AREA.
TUESDAY AND TUESDAY NIGHT...
CLOSED CIRCULATION READILY APPARENT OVER THE NORTH PACIFIC THIS
MORNING WILL REACH THE SOUTHERN PLAINS BY EARLY TUESDAY...THEN LIFT
INTO THE MID MISSISSIPPI VALLEY BY LATE TUESDAY EVENING. SURFACE LOW
WILL BEGIN TO DEEPEN EARLY TUESDAY OVER ARKLATEX THEN LIFT INTO THE
MID TO UPPER MISSISSIPPI VALLEY BY TUESDAY EVENING. THIS IS IN LINE
WITH PREVIOUS RUNS WITH FAIRLY DECENT AGREEMENT BETWEEN THE MODELS
THIS FAR OUT. TOP-DOWN SATURATION IS EXPECTED TO OCCUR AHEAD OF THE
LOW TUESDAY IN THE WARM ADVECTION...THEN DEFORMATION ZONE WITH THE
HEAVIEST SNOWFALL IS EXPECTED TO MOVE OVER THE AREA TUESDAY EVENING
AND TUESDAY NIGHT. CONTINUE TO SUSPECT THAT GUIDANCE IS SPREADING
THE PRECIP TOO FAR NORTHWEST AND EXPECT THAT A SHARPER CUTOFF IN THE
ACCUMULATING SNOW WILL OCCUR THAN MODELS ARE DEPICTING GIVEN THE
TRACK OF THE LOW. FOR THIS REASON PREFER A SOLUTION SIMILAR TO THE
GEM WHICH KEEPS THE AXIS OF HEAVIEST SNOW ALONG AND SOUTH OF THE
I-80 CORRIDOR...AGAIN BASED ON THE CURRENT PROJECTED SURFACE LOW
PATH. WITH THE UPPER WAVE STILL OFFSHORE...WE`LL LIKELY SEE SOME
ADJUSTMENTS IN THE TRACK IN THE COMING DAYS SO THERE WILL BE
REFINEMENTS...THOUGH SEVERAL INCHES APPEAR FAVORABLE ESPECIALLY IN
THE SOUTHERN PORTIONS OF THE FORECAST AREA.
WEDNESDAY THROUGH FRIDAY...
STRONG 1040MB+ HIGH IS EXPECTED TO BUILD INTO THE PLAINS WITH
RIDGING EXTENDING TOWARDS THE OHIO VALLEY BY THE END OF THE WEEK.
THIS SHOULD RESULT IN ANOTHER DRY PERIOD WITH WELL BELOW NORMAL
TEMPERATURES. UPPER AIR PATTERN BECOMES MORE ZONAL OVERHEAD WITH
SOME UNDULATIONS IN THE WEST COAST TROUGH...EVENTUALLY RESULTING IN
DOWNSTREAM AMPLIFICATION OF THE RIDGE ACROSS THE CENTRAL CONUS.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LIGHT SNOW CONTINUES THROUGH THE AFTERNOON. OCCASIONAL IFR
VIS/CIG POSSIBLE THROUGH MID-AFTERNOON...THEN IMPROVING MVFR
CONDITIONS EXPECTED THROUGH EARLY EVENING.
* PATCHY MVFR CIGS MAY LINGER THROUGH THIS EVENING.
* NORTH-NORTHEAST WINDS NEAR 10 KT GRADUALLY BACKING NORTH-
NORTHWEST BY MID-LATE AFTERNOON. WINDS INCREASE AROUND 10-12 KT
LATE AFTERNOON AND EVENING BECOMING MORE NORTHWEST WITH TIME.
RATZER
//DISCUSSION...UPDATED 18Z...
SURFACE LOW PRESSURE CENTERED OVER DECATUR IL AT 17Z...AND WILL
CONTINUE TO MOVE TO THE EAST-NORTHEAST TOWARD LAKE ERIE BY THIS
EVENING. MAIN AREA OF HEAVIER PRECIPITATION WAS OCCURRING
ALONG/SOUTH OF A KUIN-KPNT-KJXN...WITH MAINLY LIGHTER SNOW
LINGERING ACROSS NORTHERN IL TERMINALS AND KGYY. A SERIES OF MID-
LEVEL DISTURBANCES AND THE ELONGATED NATURE OF THE LOW LEVEL
FRONTAL ZONE WILL MAINTAIN LIGHT SNOW ACROSS THE AREA THROUGH THE
AFTERNOON HOURS...BEFORE SHIFTING FURTHER OFF TO THE SOUTHEAST
EARLY THIS EVENING AND ALLOWING PRECIP TO END. FOR THIS AFTERNOON
CONDITIONS ARE EXPECTED TO RANGE FROM VFR/HIGH-END MVFR FAR
NORTHWEST AT KRFD...WITH LOW-MVFR/OCNL IFR AT DPA/ORD/MDW/GYY
WHERE MORE FREQUENT/SLIGHTLY MORE INTENSE SNOW BANDS WILL OCCUR
CLOSER TO LOW TRACK AND ELEVATED FRONTAL ZONE. OCCASIONAL VIS DOWN
TO 1 TO 1 1/2SM LIKELY FOR ORD/MDW...WITH ANYTHING LOWER THAN THAT
EXPECTED TO BE VERY BRIEF IF IT OCCURS. FORCING GRADUALLY SHIFTS
SOUTHEAST LATE THIS AFTERNOON AND EVENING...ALLOWING LIGHT SNOW TO
DIMINISH AND CIGS TO IMPROVE TO OVERALL MVFR OR PERHAPS EVEN
MVFR/OCNL VFR.
AS FOR WINDS...WITH THE LOW CENTER PASSING SOUTH OF THE TERMINALS
EARLY THIS AFTERNOON WINDS WILL BACK FROM NORTHEAST TO NORTH-
NORTHWEST...AND EVENTUALLY MORE NORTHWEST BY THIS EVENING. SPEEDS
GENERALLY AROUND 10 KT...WITH A FEW GUSTS OF 12-15 KT POSSIBLE AS
COOLER AIR SPREADS IN LATE TODAY/THIS EVENING.
MODEST NORTHWEST WINDS/VFR CONDITIONS EXPECTED SUNDAY.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM-HIGH CONFIDENCE IN SNOW TRENDS...AND ASSOCIATED IMPACT ON
VIS/CIGS THROUGH THIS AFTERNOON.
* HIGH CONFIDENCE IN WIND TRENDS.
* MEDIUM-LOW CONFIDENCE IN MVFR CIGS PERSISTING OVERNIGHT.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
12Z...
SUNDAY NIGHT-MONDAY...VFR.
TUESDAY...SNOW AND IFR LIKELY ESPECIALLY DURING THE AFTERNOON AND
NIGHT. EAST FLOW.
WEDNESDAY...CHC OF SNOW AND IFR.
THURSDAY...VFR LIKELY.
FRIDAY...SLGT CHC OF SNOW DURING THE NIGHT.
MTF
&&
.MARINE...
255 AM CST
HIGH PRESSURE ACROSS THE CENTRAL PART OF THE LAKE EARLY THIS MORNING
WILL GET SHOVED NORTHWARD AS LOW PRESSURE MOVES FROM THE OZARKS
NORTHEAST TO NEAR LAKE ERIE BY THIS EVENING. THIS WILL DEVELOP A
NORTHERLY WIND BY MIDDAY AND LEAD TO A PROGRESSIVE INCREASE IN
SPEED THROUGH THE DAY. WINDS SHOULD MAXIMIZE UP TO 25 KT TONIGHT
INTO SUNDAY MORNING AS THE LAKE FINDS ITSELF WITHIN THE PRESSURE
GRADIENT BEHIND THE LOW AND AN INCOMING HIGH FROM THE NORTHERN
PLAINS. HIGH PRESSURE CENTERED JUST TO THE SOUTH OF LAKE SUNDAY
NIGHT THROUGH MONDAY NIGHT SHOULD HAVE CONDITIONS GENERALLY
TRANQUIL OVER THE LAKE IN THAT TIME. A LARGER SYSTEM HAS BEEN
SHOWN FOR SEVERAL DAYS IN COMPUTER MODEL GUIDANCE TO DEVELOP FROM
THE SOUTHERN PLAINS NORTHEASTWARD TUESDAY THROUGH WEDNESDAY. THIS
WILL INEVITABLY SHIFT SOME NORTH/SOUTH AT TIMES IN FUTURE
RUNS...BUT EVEN CONSIDERING THAT THERE IS DECENT POTENTIAL FOR
APPROACHING NORTHERLY GALES ACROSS THE LAKE WITHIN THAT PERIOD.
LOOKING AT VISIBLE SATELLITE BACK ON FRIDAY...IT APPEARED THROUGH
THE VEIL OF CIRRUS THAT ICE COVERAGE OVER THE LAKE LIKELY HAD
SHRUNK SOMEWHAT FROM THE LAST ANALYSIS...PROBABLY AS A RESULT OF
STRONG WINDS ON THURSDAY. DID NOT GET TOO FANCY BUT MINIMIZED THE
ICE COVERAGE SLIGHTLY WHICH RESULTED IN SLIGHTLY HIGHER WAVES IN
THE OPEN WATER FORECAST. NORTHWEST INDIANA WILL SEE A STRONG
ONSHORE COMPONENT TONIGHT AND CONDITIONS CLOSE TO SMALL CRAFT
ADVISORY CRITERIA WILL LIKELY EXIST. WAVES WOULD MORE THAN LIKELY
BE AT LEVEL WITHOUT ICE...BUT WITH ICE COVERAGE DAMPENING THEM
SOME...WILL NOT BE HOISTING AN ADVISORY FOR TONIGHT.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032 UNTIL 6 PM SATURDAY.
WINTER WEATHER ADVISORY...ILZ033-ILZ039 UNTIL 6 PM SATURDAY.
IN...WINTER STORM WARNING...INZ001-INZ002 UNTIL 6 PM SATURDAY.
WINTER WEATHER ADVISORY...INZ010-INZ011-INZ019 UNTIL 6 PM
SATURDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1158 AM CST Sat Feb 1 2014
.DISCUSSION...
ISSUED 1105 AM CST Sat Feb 1 2014
Very minor updates to the grids as the low pressure center moves
up and through central Illinois slightly ahead of schedule. With
the track of the low moving up just south of the Interstate 55
corridor, the cold air is wrapping around the storm and dropping
temps to the SW, with Jacksonville dropping over the last two obs.
As a result, have adjusted the wintry mix through the center of
the CWA a touch and extended a bit to the SE for later this
afternoon. Have also extended the NWrn edge of the winter wx
advisory through 00z to cover the mix precip and the cooler air
countering the WAA to the south and east. Delineation btwn
FZRA/SN/RA not as distinct and as a result, the slushy mix and
fzra potential with the cold air moving in behind the low and to
the sw of the center...the potential is increasing. Though the
moisture and radar returns to the west and southwest are
dropping...fzdz will still be an issue. That being said, the NAM
and the HRRR redevelops the precip SE of I-55 through the
afternoon. Update out momentarily.
&&
.AVIATION...
ISSUED 1115 AM CST Sat Feb 1 2014
Not much in the way of changes overall. Low center moving up and
across the area, wrapping cold air around the storm and possibly
resulting in a quicker change over to fzra or sn at SPI this
afternoon. WAA from south on the east side of IL slowing on its
progression to the north, leaving BMI in fzra through the evening.
Any warm up above freezing will likely be brief. DEC and CMI above
freezing at the sfc. Most TAF sites in Central IL dropped to
LIFR...IFR vis, with some exceptions. Winds eventually coming
around to more N/NWrly as the system moves out this afternoon.
Precip will also switch over to all sn as storm exits btwn 00z and
06z. Maintaining an MVFR cig through 18z per time heights of GFS
and NAM...although there is a brief break in the llvl moisture on HRRR
btwn 12z and 15z. However...should the breaks materialize...vis
drops will be significant problem. Will be watching the t/td
spread to the NW closely through the afternoon...but vis may be a
significant problem after 06z.
HJS
&&
.PREV DISCUSSION...
ISSUED 335 AM CST Sat Feb 1 2014
Models seem to be in fairly good agreement with the current
system, but continue to have timing issues with the next system
early next week...in the first part of the extended. The main
concerns this package do include the system today through tonight,
and then the system for Tuesday and Tue night. Overall, models
agree that a southwest flow will continue through the short term
period and into the long term period as well.
SHORT TERM...Today through Monday
The first system will move through the area today with a mix of
freezing rain and sleet across the mid section, snow north, and
all rain to the southeast where temps are slightly above freezing.
Based on radar trends the heaviest pcpn appears to be along and
north of I-72, with lighter amounts to the south. So the winter
storm warning will continue today with freezing rain, sleet and
snow across the warning area. The winter weather advisory will
also continue for areas along I-72 where minor ice accumulations
will occur. As the system moves northeast into the area,
temperatures will warm causing the freezing rain to change to all
rain. Timing for when this will occur is tricky, though it appears
it will occur toward the later part of the morning. As the system
continues to move northeast, colder air will get pulled around to
the back side of the system and change the pcpn to all snow.
Heaviest snowfall amounts will be along and northwest of the
Illinois river. Beyond tonight, conditions wild be dry as high
pressure builds into the area for the remainder of the weekend.
Temperatures will be warmer today, but then cool again as colder
air moves into the area behind the system and before the next
system.
LONG TERM...Monday night through Friday
The next system will affect the area sometime Tuesday and Tue
night as it approaches from the southwest. Current forecasts
indicate that the pcpn with this system will be all snow. Models
remain slightly different on timing of the snow, but all agree
that its coming, so pops have been increased to likely. Current
indications and forecast tracks would place the heaviest snow band
north of I-72 through the period. Then dry weather will return for
the remainder of the week.
Temperatures through the period will remain cold with coldest
temperatures expected Wed night through Thur night.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING until 6 PM CST this evening FOR ILZ027>031-
036>038-040>043-047>050.
WINTER WEATHER ADVISORY until 6 PM CST this evening FOR ILZ044-
045-051>053.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1139 AM CST SAT FEB 1 2014
.DISCUSSION...
1053 AM CST
WE WILL BE CANCELING HEADLINES ACROSS FAR NORTHERN ILLINOIS AS IT
APPEARS THE MAIN AXIS OF PRECIPITATION WILL BE MAINLY CONFINED ALONG
AND SOUTH OF A CHICAGO TO MENDOTA LINE FOR THE REST OF THE DAY.
WE ARE STILL LIKELY TO SEE SOME MODERATE PRECIP RATES AT
TIMES...ESPECIALLY SOUTH THROUGH THE DAY AS FGEN CONTINUES TO
PROVIDE AMPLE FORCING FOR ASCENT. FREEZING RAIN CONTINUES TO BE THE
MAIN CONCERN FROM PNT...THROUGH IKK TO VPZ AND POINTS SOUTH. STILL
APPEARS THAT ICE ACCUMULATIONS COULD REACH UP AROUND A QUARTER INCH
ACROSS THESE AREAS. TEMPERATURES REMAIN RIGHT AT OR JUST ABOVE
FREEZING ACROSS FAR SOUTHEASTERN SECTIONS OF THE AREA...SO IT IS
LIKELY THAT AT LEAST SOME MINOR ICE ACCUMULATIONS WILL OCCUR HERE AS
WELL OVER THE NEXT COUPLE HOURS.
COLDER AIR WILL FILTER BACK IN ACROSS EAST CENTRAL ILLINOIS AND
NORTHWESTERN INDIANA BY MID TO LATE AFTERNOON AND THIS SHOULD ALLOW
THE WINTER MIX TO CHANCE BACK OVER TO SNOW. SOME MINOR SNOW
ACCUMULATIONS ARE POSSIBLE BEFORE THE SNOW ENDS THERE.
IN THE CHICAGO METRO AREA...THERE WILL CONTINUE TO BE ADDITIONAL
PERIODS OF LIGHT TO MODERATE SNOW THROUGH AT MID TO LATE
AFTERNOON...AND THIS COULD PRODUCE ANOTHER INCH OR TWO OF SNOW.
THIS COMBINED WITH AMOUNTS OF 3 TO 5 INCHES ON THE GROUND ALREADY
COULD PUSH AMOUNTS CLOSE TO 6 INCHES. THEREFORE...I WILL LEAVE THE
WARNING IN PLACE FOR MOST OF THE CHICAGO AREA MINUS THE NORTHERN
AND FAR WESTERN SUBURBS.
KJB
//PREV DISCUSSION...
333 AM CST
THIS MORNING...
WINTER STORM CONTINUES TO DEVELOP EARLY THIS MORNING AFTER A LULL
OVERNIGHT...HOWEVER STRONG WARM AIR ADVECTION UPSTREAM OF THE
FORECAST AREA COUPLED WITH A POTENT LLVL FORCING IS GENERATING A
NARROW CHANNEL OF INTENSE PRECIPITATION.
MUCH OF THE OVERNIGHT HOURS HAD A LULL...LARGELY IN PART TO THE
QUASI-STATIONARY SFC RIDGE JUST NORTH OF THE FORECAST AREA. THIS
RESULTED IN A CONTINUED FEED OF DRIER LLVL AIR INTO NORTHERN
IL/NORTHWEST IN. THE LEADING EDGE OF THE COLDER CLOUDS CONTINUED TO
BE ERODED AS IT PUSHED NORTHEAST INTO THE PESKY ANTI-CYCLONIC
FEATURE. MEANWHILE WELL UPSTREAM OF THE FORECAST AREA IN EASTERN
KANSAS/NORTHEAST OKLAHOMA...WHERE STRONG FGEN FORCING AND
CYCLOGENESIS WAS TAKING PLACE...A NARROW CHANNEL OF INTENSE
PRECIPITATION WAS NOTED FROM SFC OBS INDICATING M1/4SM VSBYS WITH
+SN. BY 9Z THIS MORNING THIS AREA OF PRECIP HAD QUICKLY EXPANDED
NORTHEAST...AS A LARGE SLUG OF WATER VAPOR PUSHED INTO NORTHEAST
IA/NORTHWEST IL/NORTHEAST MO. LOCAL RADAR NOTED STEADILY INCREASING
RETURNS BY 9Z OVER THE FORECAST AREA...WITH A HANDFUL OF POINTS
ALONG AND WEST OF A STERLING TO PONTIAC LINE BEGINNING TO REPORT LGT
SNOW.
THEN THE CHALLENGE BEGINS FOR MID-MORNING THRU MIDDAY...WITH RESPECT
TO HOW MUCH FREEZING RAIN THE SOUTHERN PORTIONS OF THE CWFA RECEIVE.
THEN TO THE NORTH OF THIS...HOW MUCH SNOW. DUE TO THE PESKY SFC
RIDGE TO THE NORTH...THE BETTER PUSH OF WARMER LLVL AIR HAS REMAINED
WELL SOUTH ACROSS SOUTHERN IL WHERE SFC TEMPS ARE HOVERING EARLY
THIS MORNING ARND 32 DEGREES. HOWEVER EXPECT WITH THE RAPID GROWTH
AND EXPANSION OF THE MODERATE SNOW OVERSPREADING NORTHERN IL BY
11-14Z...TEMPS SOUTH OF LASALLE TO KANKAKEE WILL BEGIN TO WARM INTO
THE UPR 20S.
MOST GUIDANCE MEMBERS HAVE BACKED OFF ON THE QPF TOTALS FOR
TDY...LARGELY DUE TO THE LULL OVERNIGHT AND WITH THE WAVE AT 850MB
REMAINING OPEN AND PROGRESSIVE...THIS APPEARS TO MAKE SOME SENSE.
HOWEVER WITH THE IMPRESSIVE DYNAMICS GOING ON UPSTREAM EARLY THIS
MORNING...IT IS DIFFICULT TO MAKE TOO MANY CHANGES. THE ONE AREA
THAT CONFIDENCE IS SLIGHTLY HIGHER ON IS THAT SNOWFALL TOTALS MAY
FALL JUST UNDER EARLIER THINKING. HAVE HELD ONTO THE CURRENT WINTER
STORM WARNING AND ADVISORIES...BUT FEEL IT WILL BE MORE IN LINE WITH
THE HIGHEST SNOWFALL TOTALS AROUND 5 TO 8". LOCAL HI-RES WRF OUTPUT
SUGGESTS THE AXIS OF BETTER QPF AND SNOWFALL WOULD FALL FURTHER
SOUTH THEN CURRENT THINKING...OR ALONG A LASALLE/PONTIAC TO SOUTH
CHICAGO/MICHIGAN CITY LINE. COBB OUTPUT FOR A HANDFUL OF POINTS
INDICATE GENERALLY AROUND 5 TO 7".
AS FOR FREEZING RAIN...THE STRONG WARM AIR ADVECTION NOTED EARLY
THIS MORNING UPSTREAM OF THE FORECAST AREA...IS SHOWING UP IN THE
MODEL SOUNDINGS ACROSS THE SOUTHERN CWFA. HOWEVER PROFILES ONLY HUG
THE 0 DEG ISOTHERM...SUGGESTING THAT PERHAPS ONLY A PARTIAL MELT
WILL OCCUR. GIVEN THE STRONG FORCING THAT IS ANTICIPATED...WILL
CONTINUE TO OPT FOR A FULL MELT IN THE SOUTHERN CWFA WITH P-TYPE
CHANGING TO FZRA OR A PERIOD OF RA LATER THIS MORNING THRU EARLY
AFTN.
THE BULK OF THE SNOW WILL BE SLOWER TO END THIS AFTN FROM WEST TO
EAST...AS HIGH PRESSURE ACROSS THE NORTHERN PLAINS DRIFTS EAST
THROUGHOUT THE DAY. COULD SEE THE NEED FOR LGT SNOW LINGERING ACROSS
THE WESTERN CWFA INTO THE LATE AFTN HOURS BEFORE ENDING. TEMPS FOR
THE BULK OF THE CWFA WILL WARM INTO THE MID/UPR 20S...WITH AREAS
ALONG AND SOUTH OF LASALLE TO CHICAGO SEEING TEMPS ARND 30 TO THE
LOWER 30S. CLOSER TO GIBSON CITY TO DEMOTTE TEMPS MAY WARM INTO THE
UPR 30S.
BEACHLER
SUNDAY THROUGH MONDAY...
SURFACE HIGH WILL TRANSLATE EASTWARD FROM THE CENTRAL PLAINS ACROSS
THE MID MISSISSIPPI VALLEY WHICH IN COMBINATION WITH SHORTWAVE
RIDGING ALOFT WILL PROVIDE DRY ALBEIT COOL WEATHER THROUGH THE
PERIOD. H85 TEMPS BOTTOM OUT AROUND -12C AND EXPECT SURFACE TEMPS TO
ONLY BE ABLE TO WARM INTO THE MID TEENS SUNDAY AFTERNOON. SUNDAY
NIGHT THE RIDGE AXIS WILL MOVE OVERHEAD AND SKIES SHOULD BE MOSTLY
CLEAR SETTING UP A FAVORABLE RADIATIONAL COOLING SETUP RESULTING IN
LOWS ONCE AGAIN FALLING BELOW ZERO FOR MUCH OF THE CWA. SURFACE HIGH
STAYS OVER THE AREA ON MONDAY BUT OUR NEXT SYSTEM DEVELOPING OVER
THE SOUTHERN PLAINS WILL BEGIN TO LIFT THE H85 BAROCLINIC ZONE
TOWARDS THE AREA. EXPECT CLOUD COVER TO INCREASE ON MONDAY AS
ISENTROPIC ASCENT OVERSPREADS THE AREA.
TUESDAY AND TUESDAY NIGHT...
CLOSED CIRCULATION READILY APPARENT OVER THE NORTH PACIFIC THIS
MORNING WILL REACH THE SOUTHERN PLAINS BY EARLY TUESDAY...THEN LIFT
INTO THE MID MISSISSIPPI VALLEY BY LATE TUESDAY EVENING. SURFACE LOW
WILL BEGIN TO DEEPEN EARLY TUESDAY OVER ARKLATEX THEN LIFT INTO THE
MID TO UPPER MISSISSIPPI VALLEY BY TUESDAY EVENING. THIS IS IN LINE
WITH PREVIOUS RUNS WITH FAIRLY DECENT AGREEMENT BETWEEN THE MODELS
THIS FAR OUT. TOP-DOWN SATURATION IS EXPECTED TO OCCUR AHEAD OF THE
LOW TUESDAY IN THE WARM ADVECTION...THEN DEFORMATION ZONE WITH THE
HEAVIEST SNOWFALL IS EXPECTED TO MOVE OVER THE AREA TUESDAY EVENING
AND TUESDAY NIGHT. CONTINUE TO SUSPECT THAT GUIDANCE IS SPREADING
THE PRECIP TOO FAR NORTHWEST AND EXPECT THAT A SHARPER CUTOFF IN THE
ACCUMULATING SNOW WILL OCCUR THAN MODELS ARE DEPICTING GIVEN THE
TRACK OF THE LOW. FOR THIS REASON PREFER A SOLUTION SIMILAR TO THE
GEM WHICH KEEPS THE AXIS OF HEAVIEST SNOW ALONG AND SOUTH OF THE
I-80 CORRIDOR...AGAIN BASED ON THE CURRENT PROJECTED SURFACE LOW
PATH. WITH THE UPPER WAVE STILL OFFSHORE...WE`LL LIKELY SEE SOME
ADJUSTMENTS IN THE TRACK IN THE COMING DAYS SO THERE WILL BE
REFINEMENTS...THOUGH SEVERAL INCHES APPEAR FAVORABLE ESPECIALLY IN
THE SOUTHERN PORTIONS OF THE FORECAST AREA.
WEDNESDAY THROUGH FRIDAY...
STRONG 1040MB+ HIGH IS EXPECTED TO BUILD INTO THE PLAINS WITH
RIDGING EXTENDING TOWARDS THE OHIO VALLEY BY THE END OF THE WEEK.
THIS SHOULD RESULT IN ANOTHER DRY PERIOD WITH WELL BELOW NORMAL
TEMPERATURES. UPPER AIR PATTERN BECOMES MORE ZONAL OVERHEAD WITH
SOME UNDULATIONS IN THE WEST COAST TROUGH...EVENTUALLY RESULTING IN
DOWNSTREAM AMPLIFICATION OF THE RIDGE ACROSS THE CENTRAL CONUS.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LIGHT SNOW CONTINUES THROUGH THE AFTERNOON. OCCASIONAL IFR
VIS/CIG POSSIBLE THROUGH MID-AFTERNOON...THEN IMPROVING MVFR
CONDITIONS EXPECTED THROUGH EARLY EVENING.
* PATCHY MVFR CIGS MAY LINGER THROUGH THIS EVENING.
* NORTH-NORTHEAST WINDS NEAR 10 KT GRADUALLY BACKING NORTH-
NORTHWEST BY MID-AFTERNOON. WINDS INCREASE AROUND 10-12 KT LATE
AFTERNOON AND EVENING BECOMING MORE NORTHWEST WITH TIME.
RATZER
//DISCUSSION...UPDATED 18Z...
SURFACE LOW PRESSURE CENTERED OVER DECATUR IL AT 17Z...AND WILL
CONTINUE TO MOVE TO THE EAST-NORTHEAST TOWARD LAKE ERIE BY THIS
EVENING. MAIN AREA OF HEAVIER PRECIPITATION WAS OCCURRING
ALONG/SOUTH OF A KUIN-KPNT-KJXN...WITH MAINLY LIGHTER SNOW
LINGERING ACROSS NORTHERN IL TERMINALS AND KGYY. A SERIES OF MID-
LEVEL DISTURBANCES AND THE ELONGATED NATURE OF THE LOW LEVEL
FRONTAL ZONE WILL MAINTAIN LIGHT SNOW ACROSS THE AREA THROUGH THE
AFTERNOON HOURS...BEFORE SHIFTING FURTHER OFF TO THE SOUTHEAST
EARLY THIS EVENING AND ALLOWING PRECIP TO END. FOR THIS AFTERNOON
CONDITIONS ARE EXPECTED TO RANGE FROM VFR/HIGH-END MVFR FAR
NORTHWEST AT KRFD...WITH LOW-MVFR/OCNL IFR AT DPA/ORD/MDW/GYY
WHERE MORE FREQUENT/SLIGHTLY MORE INTENSE SNOW BANDS WILL OCCUR
CLOSER TO LOW TRACK AND ELEVATED FRONTAL ZONE. OCCASIONAL VIS DOWN
TO 1 TO 1 1/2SM LIKELY FOR ORD/MDW...WITH ANYTHING LOWER THAN THAT
EXPECTED TO BE VERY BRIEF IF IT OCCURS. FORCING GRADUALLY SHIFTS
SOUTHEAST LATE THIS AFTERNOON AND EVENING...ALLOWING LIGHT SNOW TO
DIMINISH AND CIGS TO IMPROVE TO OVERALL MVFR OR PERHAPS EVEN
MVFR/OCNL VFR.
AS FOR WINDS...WITH THE LOW CENTER PASSING SOUTH OF THE TERMINALS
EARLY THIS AFTERNOON WINDS WILL BACK FROM NORTHEAST TO NORTH-
NORTHWEST...AND EVENTUALLY MORE NORTHWEST BY THIS EVENING. SPEEDS
GENERALLY AROUND 10 KT...WITH A FEW GUSTS OF 12-15 KT POSSIBLE AS
COOLER AIR SPREADS IN LATE TODAY/THIS EVENING.
MODEST NORTHWEST WINDS/VFR CONDITIONS EXPECTED SUNDAY.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM-HIGH CONFIDENCE IN SNOW TRENDS...AND ASSOCIATED IMPACT ON
VIS/CIGS THROUGH THIS AFTERNOON.
* HIGH CONFIDENCE IN WIND TRENDS.
* MEDIUM-LOW CONFIDENCE IN MVFR CIGS PERSISTING OVERNIGHT.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
12Z...
SUNDAY NIGHT-MONDAY...VFR.
TUESDAY...SNOW AND IFR LIKELY ESPECIALLY DURING THE AFTERNOON AND
NIGHT. EAST FLOW.
WEDNESDAY...CHC OF SNOW AND IFR.
THURSDAY...VFR LIKELY.
FRIDAY...SLGT CHC OF SNOW DURING THE NIGHT.
MTF
&&
.MARINE...
255 AM CST
HIGH PRESSURE ACROSS THE CENTRAL PART OF THE LAKE EARLY THIS MORNING
WILL GET SHOVED NORTHWARD AS LOW PRESSURE MOVES FROM THE OZARKS
NORTHEAST TO NEAR LAKE ERIE BY THIS EVENING. THIS WILL DEVELOP A
NORTHERLY WIND BY MIDDAY AND LEAD TO A PROGRESSIVE INCREASE IN
SPEED THROUGH THE DAY. WINDS SHOULD MAXIMIZE UP TO 25 KT TONIGHT
INTO SUNDAY MORNING AS THE LAKE FINDS ITSELF WITHIN THE PRESSURE
GRADIENT BEHIND THE LOW AND AN INCOMING HIGH FROM THE NORTHERN
PLAINS. HIGH PRESSURE CENTERED JUST TO THE SOUTH OF LAKE SUNDAY
NIGHT THROUGH MONDAY NIGHT SHOULD HAVE CONDITIONS GENERALLY
TRANQUIL OVER THE LAKE IN THAT TIME. A LARGER SYSTEM HAS BEEN
SHOWN FOR SEVERAL DAYS IN COMPUTER MODEL GUIDANCE TO DEVELOP FROM
THE SOUTHERN PLAINS NORTHEASTWARD TUESDAY THROUGH WEDNESDAY. THIS
WILL INEVITABLY SHIFT SOME NORTH/SOUTH AT TIMES IN FUTURE
RUNS...BUT EVEN CONSIDERING THAT THERE IS DECENT POTENTIAL FOR
APPROACHING NORTHERLY GALES ACROSS THE LAKE WITHIN THAT PERIOD.
LOOKING AT VISIBLE SATELLITE BACK ON FRIDAY...IT APPEARED THROUGH
THE VEIL OF CIRRUS THAT ICE COVERAGE OVER THE LAKE LIKELY HAD
SHRUNK SOMEWHAT FROM THE LAST ANALYSIS...PROBABLY AS A RESULT OF
STRONG WINDS ON THURSDAY. DID NOT GET TOO FANCY BUT MINIMIZED THE
ICE COVERAGE SLIGHTLY WHICH RESULTED IN SLIGHTLY HIGHER WAVES IN
THE OPEN WATER FORECAST. NORTHWEST INDIANA WILL SEE A STRONG
ONSHORE COMPONENT TONIGHT AND CONDITIONS CLOSE TO SMALL CRAFT
ADVISORY CRITERIA WILL LIKELY EXIST. WAVES WOULD MORE THAN LIKELY
BE AT LEVEL WITHOUT ICE...BUT WITH ICE COVERAGE DAMPENING THEM
SOME...WILL NOT BE HOISTING AN ADVISORY FOR TONIGHT.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-ILZ012-
ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032
UNTIL 6 PM SATURDAY.
WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ033-ILZ039 UNTIL 6 PM
SATURDAY.
IN...WINTER STORM WARNING...INZ001-INZ002 UNTIL 6 PM SATURDAY.
WINTER WEATHER ADVISORY...INZ010-INZ011-INZ019 UNTIL 6 PM
SATURDAY.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1114 AM CST Sat Feb 1 2014
.DISCUSSION...
ISSUED 1105 AM CST Sat Feb 1 2014
Very minor updates to the grids as the low pressure center moves
up and through central Illinois slightly ahead of schedule. With
the track of the low moving up just south of the Interstate 55
corridor, the cold air is wrapping around the storm and dropping
temps to the SW, with Jacksonville dropping over the last two obs.
As a result, have adjusted the wintry mix through the center of
the CWA a touch and extended a bit to the SE for later this
afternoon. Have also extended the NWrn edge of the winter wx
advisory through 00z to cover the mix precip and the cooler air
countering the WAA to the south and east. Delineation btwn
FZRA/SN/RA not as distinct and as a result, the slushy mix and
fzra potential with the cold air moving in behind the low and to
the sw of the center...the potential is increasing. Though the
moisture and radar returns to the west and southwest are
dropping...fzdz will still be an issue. That being said, the NAM
and the HRRR redevelops the precip SE of I-55 through the
afternoon. Update out momentarily.
HJS
&&
.AVIATION...
ISSUED 554 AM CST Sat Feb 1 2014
IFR ceilings/visbys expected today, as low pressure tracks through
the area. Precip type will be tricky as warmer air flows northward
ahead of the approaching system. Models continue to show a
pronounced warm layer aloft, resulting in mainly freezing rain at
the KILX TAF sites early this morning. The exception will be KPIA
where snow will be the dominant precip type throughout the entire
event. Given surface temps already approaching the freezing mark,
have transitioned the precip to rain at KDEC/KCMI by 14z and at
KSPI by 15z. Will maintain freezing rain into the afternoon at
KBMI thanks tp slightly colder temps. As low pulls away and winds
become northwesterly, precip will change to light snow across the
board late this afternoon into the evening. Models suggest a
secondary wave moving along the departing front will keep chances
for light snow alive until shortly after midnight when precip
finally tapers off and comes to an end.
Barnes
&&
.PREV DISCUSSION...
ISSUED 335 AM CST Sat Feb 1 2014
Models seem to be in fairly good agreement with the current
system, but continue to have timing issues with the next system
early next week...in the first part of the extended. The main
concerns this package do include the system today through tonight,
and then the system for Tuesday and Tue night. Overall, models
agree that a southwest flow will continue through the short term
period and into the long term period as well.
SHORT TERM...Today through Monday
The first system will move through the area today with a mix of
freezing rain and sleet across the mid section, snow north, and
all rain to the southeast where temps are slightly above freezing.
Based on radar trends the heaviest pcpn appears to be along and
north of I-72, with lighter amounts to the south. So the winter
storm warning will continue today with freezing rain, sleet and
snow across the warning area. The winter weather advisory will
also continue for areas along I-72 where minor ice accumulations
will occur. As the system moves northeast into the area,
temperatures will warm causing the freezing rain to change to all
rain. Timing for when this will occur is tricky, though it appears
it will occur toward the later part of the morning. As the system
continues to move northeast, colder air will get pulled around to
the back side of the system and change the pcpn to all snow.
Heaviest snowfall amounts will be along and northwest of the
Illinois river. Beyond tonight, conditions wild be dry as high
pressure builds into the area for the remainder of the weekend.
Temperatures will be warmer today, but then cool again as colder
air moves into the area behind the system and before the next
system.
LONG TERM...Monday night through Friday
The next system will affect the area sometime Tuesday and Tue
night as it approaches from the southwest. Current forecasts
indicate that the pcpn with this system will be all snow. Models
remain slightly different on timing of the snow, but all agree
that its coming, so pops have been increased to likely. Current
indications and forecast tracks would place the heaviest snow band
north of I-72 through the period. Then dry weather will return for
the remainder of the week.
Temperatures through the period will remain cold with coldest
temperatures expected Wed night through Thur night.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING until 6 PM CST this evening FOR ILZ027>031-
036>038-040>043-047>050.
WINTER WEATHER ADVISORY until 6 PM CST this evening FOR ILZ044-
045-051>053.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
547 PM EST SAT FEB 1 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 406 PM EST SAT FEB 1 2014
RAIN WILL CHANGE BACK TO A WINTRY MIX AND THEN SNOW TONIGHT AS
COLDER AIR RETURNS WITH THE PASSAGE OF A FRONTAL BOUNDARY. HIGH
PRESSURE WILL TRACK THROUGH THE REGION WITH COLD DRY WEATHER FOR THE
EARLY PART OF THE WEEK. A LARGE STORM SYSTEM WILL TRACK THROUGH THE
OHIO VALLEY TUESDAY AND WEDNESDAY...BRINGING THE POTENTIAL FOR
ACCUMULATING SNOW AND ICE. AFTER A BRIEF RESPITE...YET ANOTHER STORM
MAY BRING MORE SNOW FOR FRIDAY AND SATURDAY.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 406 PM EST SAT FEB 1 2014
RAIN SHOWERS CONTINUE TO IMPACT THE NORTHWEST HALF OF THE FORECAST
AREA THIS AFTERNOON. QUITE THE TEMPERATURE GRADIENT AT 20Z AS WARM
ADVECTION HAS DRAWN MUCH WARMER AIR INTO THE OHIO VALLEY. TEMPS
RANGED FROM THE MID/UPPER 30S OVER THE NORTHERN WABASH VALLEY TO THE
LOWER 50S OVER FAR SOUTHERN COUNTIES.
STARTING OFF A NEW MONTH WITH THE SAME OLD STORY...ANOTHER SHOT OF
WINTRY WEATHER TONIGHT AS COLDER AIR SPILLS BACK INTO CENTRAL
INDIANA BEHIND A COLD FRONT. THE FRONT WILL MOVE SOUTHEAST ACROSS
THE FORECAST AREA TONIGHT BUT AT A SLOW PACE AS THE BOUNDARY BECOMES
NEARLY STATIONARY TO THE MEAN UPPER FLOW. THE RESULT FROM THIS WILL
BE FOR NEAR SURFACE COOLING TO COMMENCE AT A FASTER PACE THAN THE
ADVECTION OF BOUNDARY LAYER COOLING OVER THE PRECIP SHIELD BEGINNING
OVER THE NORTHWEST THIS EVENING...EXPANDING SOUTHEAST ACROSS THE
FORECAST AREA OVERNIGHT.
LOW LEVEL THERMAL PROFILES BECOMING INCREASINGLY SUPPORTIVE OF A
MESSIER TRANSITION PERIOD OF 1-3 HOURS WITH A WINTRY MIX OF FREEZING
RAIN...SLEET AND SNOW BEFORE THE COLUMN COOLS ENOUGH TO SUPPORT ALL
SNOW. CURRENT HRRR EVEN HINTS AT THE POTENTIAL FOR SOME BANDING TO
SNOW OVER NORTHWEST COUNTIES THIS EVENING WHICH MAY SERVE TO
TRANSFER TO SNOW MORE QUICKLY AND PRODUCE ACCUMS OF 1 TO 2 INCHES
WITH EVEN LOCALLY HIGHER AMOUNTS ACROSS THE NORTHERN WABASH VALLEY.
FURTHER SOUTH AND EAST...EXPECT LIGHT ACCUMS OF ICE AND SNOW. OTHER
THAN FAR SOUTHEAST COUNTIES... EXPECT PRECIP FALLING AS ALL SNOW
OVER MOST AREAS AFTER 08-09Z. LIGHT SNOW WILL END FROM THE NORTHWEST
LATE TONIGHT.
HAVE CHOSEN TO ISSUE AN SPS FOR TONIGHT TO HIGHLIGHT THE LIGHT
SNOW/ICE ACCUMS AND POTENTIAL FOR SLICK SPOTS WITH REFREEZING AS
TEMPS FALL. AT THIS POINT...UNCERTAINTY REMAINS JUST TOO HIGH TO
WARRANT ISSUING AN ADVISORY AS TIMING OF THE CHANGEOVER AND EXTENT
OF TIME A CERTAIN PRECIP TYPE FALLS WILL BE CRITICAL IN DETERMINING
SNOW AND ICE AMOUNTS. EVENING SHIFT WILL CONTINUE TO MONITOR AND
ADJUST AS NEEDED.
TEMPS...USED NAM HOURLIES FOR TEMPS OVER THE NEXT SEVERAL HOURS AS
THEY FALL IN THE WAKE OF THE FRONTAL PASSAGE. MOS GUIDANCE LOOKED
REASONABLE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
ISSUED AT 406 PM EST SAT FEB 1 2014
FORECAST CHALLENGES FOCUS ON POPS FOR SUNDAY AS FRONTAL BOUNDARY
SLOWLY SAGS SOUTH THROUGH THE OHIO VALLEY. IN ADDITION...A SECONDARY
WAVE WILL TRACK ALONG THE FRONT OVER THE TENNESSEE AND LOWER OHIO
VALLEYS SUNDAY NIGHT AND EARLY MONDAY. MODEL GUIDANCE CONTINUES TO
SLOWLY SHIFT THE NORTHERN EDGE OF THE MOISTURE SHIELD NORTH...WITH
SOME SUGGESTIONS THAT LIGHT SNOW MAY MANAGE TO GET NORTH OF THE OHIO
RIVER AND INTO FAR SOUTHERN INDIANA FOR A PERIOD OF TIME SUNDAY
NIGHT. WHILE THE SLOWER DEPARTURE OF THE FRONT WILL WARRANT
LINGERING POPS OVER THE SOUTHEAST HALF OF THE FORECAST AREA SUNDAY
MORNING...WILL MAINTAIN DRY FORECAST FROM EARLY AFTERNOON SUNDAY ON
WITH DEEPER FORCING AND MOISTURE ASSOCIATED WITH THE WAVE REMAINING
ALONG AND SOUTH OF THE OHIO RIVER. ANY ADDITIONAL SHIFTS NORTH
HOWEVER WITH FUTURE MODEL RUNS WILL LIKELY REQUIRE INTRODUCING LOW
CHANCES FOR SNOW SUNDAY NIGHT OVER FAR SOUTHERN COUNTIES.
A BROAD AREA OF HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE
WEST MONDAY MORNING AND SHOULD SERVE TO FINALLY PUSH THE FRONT
FURTHER SOUTH AND EAST AND AWAY FROM THE OHIO VALLEY. WITH MODEL
SOUNDINGS INDICATING PRESENCE OF SUBSIDENCE AND DRIER AIR ANTICIPATE
PLENTY OF SUNSHINE MONDAY. MID AND HIGH LEVEL CLOUD COVER WILL BEGIN
TO INCREASE FROM THE SOUTHWEST MONDAY NIGHT AS THE STORM SYSTEM THAT
WILL IMPACT THE REGION LATER ON TUESDAY INTO WEDNESDAY ORGANIZES
OVER TEXAS AND THE WESTERN GULF.
TEMPS...GENERALLY LEANED TOWARDS THE COLDER MAVMOS THROUGH THE
PERIOD WHICH MATCHED MORE CLOSELY WITH THE LOW LEVEL THERMALS. COULD
SEE QUITE THE TEMP GRADIENT NORTH TO SOUTH FOR LOWS SUNDAY
NIGHT...WITH LOWS NEAR ZERO IN THE NORTHERN WABASH VALLEY WHERE
SKIES WILL BE PARTLY CLOUDY AND THE POTENTIAL FOR A COUPLE INCHES OF
SNOW ON THE GROUND WOULD HELP TEMPS TUMBLE. CLOUD SHIELD FROM
SURFACE WAVE TRACKING TO THE SOUTH SUNDAY NIGHT WILL KEEP TEMPS UP A
BIT FROM I-70 SOUTH...POSSIBLY ONLY FALLING TO AROUND 20 IN THE
EXTREME SOUTH.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
ISSUED AT 257 PM EST SAT FEB 1 2014
FOCUS REMAINS POSSIBLE WINTER STORM TUESDAY INTO WEDNESDAY.
CONTINUE TO PREFER A BLEND OF GUIDANCE WITH LESS RELIANCE ON
SOMEWHAT LESS CONSISTENT GFS. GFS LOW TRACK HAS SHIFTED SLIGHTLY
SOUTHEAST AND EURO SLIGHTLY NORTHWEST...ALTHOUGH EURO REMAINS
CONSISTENTLY THE COLDER MODEL AND GFS WARMER ODDLY ENOUGH. GFS
ENSEMBLE MEMBERS REMAIN LOOSELY CLUSTERED BUT AROUND A FURTHER
SOUTHEAST TRACK THAN PREVIOUS DAYS...BUT THIS HAS YET TO TRANSLATE
TO A COLDER SOLUTION IN THE LOW LEVELS.
AS SUCH...WILL CONTINUE WITH ALL SNOW MAINLY NORTH/NORTHWEST OF
INDY...WITH A CHANCE OF SLEET/FREEZING RAIN MIXING IN A SWATH
SOUTH OF THIS...AND FREEZING RAIN/SLEET WITH A CHANCE OF SNOW
ACROSS THE FAR SOUTH LATE TUESDAY INTO TUESDAY EVENING. ALL PRECIP
AFTER 06Z WEDNESDAY LIKELY SNOW OR QUICKLY TRANSITIONING TO SNOW.
MESOSCALE FEATURES WILL BE IN PLAY AND AS SUCH AMOUNTS REMAIN VERY
DIFFICULT TO PINPOINT. BANDING WILL BE AN ISSUE WHICH COULD IMPACT
BOTH AMOUNTS AND PRECIP TYPE OWING TO DYNAMIC EFFECTS.
MESSAGE REMAINS THE SAME. CENTRAL INDIANA RESIDENTS SHOULD BE
PREPARED FOR A POSSIBLE WINTER STORM BEGINNING TUESDAY AND
CONTINUING INTO EARLY WEDNESDAY WITH THE POTENTIAL FOR
ACCUMULATING SNOW AND SLEET/ICE.
&&
.AVIATION /DISCUSSION FOR THE 020000Z TAFS/...
ISSUED AT 547 PM EST SAT FEB 1 2014
DIFFICULT FORECAST WITH RESPECT TO PRECIPITATION TYPES AND CHANGE
OVER TIMING AS SHARP COLD FRONT WILL BE PASSING OVER THE TAF SITES
DURING THE NEXT SEVERAL HOURS WITH LIFTING OVER THE FRONT CONTINUING
WELL INTO THE EARLY MORNING HOURS ON SUNDAY.
COLD FRONT HAS PASSED THROUGH KLAF...WITH SHORT TERM MODEL DATA
SUGGESTING FRONT WILL CLEAR THE REMAINING TAF SITES BY 020200Z. COLD
ADVECTION LOOKS FAIRLY STRONG...WITH MODELS SUGGESTING THE ELEVATED
WARM LAYER DISAPPEARING WITHING ABOUT 4-6 HOURS AFTER FRONTAL
PASSAGE...SUGGESTING A CHANGEOVER TO SNOW BY THAT TIME. WILL USE
THIS THINKING TO TIME THE CHANGEOVER AT THE TAF SITES TONIGHT. GOOD
POTENTIAL FOR A PERIOD OF FREEZING RAIN/SLEET AS WELL EMBEDDED
WITHIN THE TRANSITION ZONE. APPEARS SURFACE FREEZING LINE WILL BE
CLOSE TO KLAF BY ISSUANCE TIME...SO WILL START THAT SITE WITH
FREEZING RAIN.
OTHERWISE...GENERALLY EXPECTING AREAS OF IFR VISIBILITY RESTRICTIONS
IN RAIN AND FOG AHEAD OF THE FRONT...WITH IFR CEILINGS AROUND
005-006 AGL ALONG WITH IFR VISIBILITY RESTRICTIONS ONCE THE
PRECIPITATION CHANGES OVER TO SNOW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM...NIELD
AVIATION...JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
534 PM EST SAT FEB 1 2014
.SYNOPSIS...
ISSUED AT 526 PM EST SAT FEB 1 2014
A SLOW MOVING UPPER LEVEL SYSTEM WILL SHIFT EASTWARD
TONIGHT...EVENTUALLY SHIFTING PRECIPITATION EAST OF THE AREA LATE
TONIGHT INTO EARLY SUNDAY MORNING. COLDER AIR FILTERING INTO THE
REGION TONIGHT WILL ALLOW FOR PRECIPITATION TO CHANGEOVER TO SNOW
BEFORE ENDING ACROSS NORTHEAST INDIANA...NORTHWEST OHIO...AND
SOUTHEAST LOWER MICHIGAN. QUIET CONDITIONS ARE EXPECTED ON SUNDAY
AND MONDAY AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION.
HOWEVER...A STRONG STORM SYSTEM IS EXPECTED TO ORGANIZE ACROSS THE
SOUTHERN ROCKIES ON MONDAY...AND THEN BRING A POTENTIAL OF SOME
SIGNIFICANT SNOWFALL TO THE REGION FROM TUESDAY THROUGH EARLY WEDNESDAY.
&&
.SHORT TERM...(THROUGH TONIGHT)
ISSUED AT 337 PM EST SAT FEB 1 2014
...MESSY AFTERNOON/EVENING ON TAP FOR THE AREA...
AS OF 230 PM...LOCATIONS SOUTH OF A KANKAKEE...TO GOSHEN TO ANGOLA
LINE WERE SEEING ALL RAIN AS TEMPERATURES WERE IN THE MIDDLE 30S TO
NEAR 40 (FAR SOUTHEAST). PRIOR TO MIXING/SWITCHOVER...NUMEROUS
REPORTS OF 3 TO 5 INCHES OF SNOW CAME IN ACROSS THE WARNING AREA
WITH ANYWHERE FROM 1 TO 4 INCHES. BROAD AREA OF LOW PRESSURE WAS
LOCATED SOMEWHERE NEAR WHITE COUNTY...A BIT FURTHER NORTHWEST THAN
EXPECTED. RUC HAS BEEN HANDLING MANY OF THE FINER DETAILS QUITE WELL
AND WAS USED ALMOST EXCLUSIVELY FOR THE FORECAST INTO THIS EVENING.
THE LOW SHOULD TRACK ACROSS THE CENTRAL PORTIONS OF THE CWA BUT
ALSO SHOWING A FASTER TREND SO PREVIOUSLY THOUGHT CHANGE OVER TIMES
STILL LOOK REASONABLE. AS THE TRANSITION COMMENCES A BRIEF PERIOD OF
SLEET/FREEZING RAIN MAY OCCUR. ONCE THIS OCCURS...SEVERAL HOURS OF
SNOW IS EXPECTED WITH ADDITIONAL QPF VALUES OF ROUGHLY ONE QUARTER
INCH OR SO IN FAR NW AREAS TO A BAND OF THREE QUARTERS OF AN INCH OR
MORE IN SE HALF OR SO. MUCH OF THIS HEAVIER PRECIP WILL FALL IN THE
FORM OF RAIN...BUT MUCH LIKE FURTHER NW A QUARTER TO THIRD OF AN
INCH WILL LIKELY FALL AS SNOW. JUST AS WAS THE CASE EARLIER
TODAY...TOO MUCH UNCERTAINTY CONTINUES IN TRANSITION TO WARRANT ANY
HEADLINE CHANGES. IT COULD BE CLOSE FOR FULL WARNING CRITERIA BEING
MET IN SOME AREAS...BUT WARNING WAS ISSUED FOR A COMBINATION OF
EARLIER SNOW AND EXPECTED SNOW BEHIND THE LOW SO SHOULD WORK OUT FOR
THE MOST PART. FURTHER UPDATES AND REFINEMENTS ARE LIKELY INTO THIS
EVENING. NEEDLESS TO SAY...ONCE TEMPS START TO FALL..ROAD CONDITIONS
WILL BECOME MESSY AND VERY SLIPPERY WELL INTO THE OVERNIGHT HOURS.
&&
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 337 PM EST SAT FEB 1 2014
ENERGETIC IMPULSE LADEN FLW EMBEDDED WITHIN PROJECTED NEG PNA PATTN
ACRS NOAM SPELLS HIGH IMPACT WX ACRS THE OH VALLEY THIS PD. OF NOTE
CONTS TO BE W/SYS SEEN THIS AFTN ON VAPOR OUT NR 42N/137W WHICH DIGS
SEWD INTO NRN BAHA ON MON AND THEN LIFTS OUT THROUGH THE LWR OH
VALLEY AS LARGER SCALE ARCTIC STREAM SW DROPS SWD INTO THE WRN US.
PRONOUNCED POLAR RIDGING BLDG IN WAKE OF SHRT TERM SYS PASSAGE TO
PROVIDE A BRIEF DRY BUT COLD RESPITE FROM WINTERS ONSLAUGHT. HWVR
DEEP SRN PLAINS EJECTION POINT AND STG GOMEX RTN FLW INTO SRN
PERIPHERY OF RETREATING SFC RIDGE LOOK TO PROVIDE FOR SIG CYCLONE
DVLPMNT OVR THE LWR MS VALLEY EARLY TUE AND UP THROUGH THE ERN OH
VALLEY ON WED AS EXEMPLIFIED IN STABLE SPECTRAL TRACK. DETAILS AS
YET TO BE IRONED OUT BUT SIG IMPACTS XPCD BOTH W/WIND AND SNOW
PARTICULARLY TUE AFTN-WED AM.
OTRWS ARCTIC RIDGE BLDS EWD OUT OF THE PLAINS THU-FRI W/VERY COLD
TEMPS YET LOOKS TO SET THE STAGE FOR YET ANOTHER SIG OH VALLEY
CYCLONE NXT WEEKEND AS DEEP WRN TROUGH RELOADS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 526 PM EST SAT FEB 1 2014
PRIMARY AVIATION FORECAST CONCERN THIS EVENING WILL BE ONGOING
PRECIP EVENT AND PRECIP TYPE CHANGEOVER TIMING AT KFWA.
A LOW LEVEL THERMAL RIDGE HAS ADVECTED INTO THE AREA ALLOWING FOR
MOST OF NORTHERN INDIANA TO HAVE SWITCHED OVER TO A PERIOD OF RAIN
THIS AFTERNOON. SFC REFLECTION OF THIS SYSTEM HAS SHIFTED INTO
SOUTHEAST LOWER MICHIGAN WHICH HAS ALLOWED FOR WIND SHIFT TO THE
NORTHWEST ACROSS NORTH CENTRAL INDIANA INCLUDING KSBN. THIS WIND
SHIFT WILL PROGRESS SOUTHEASTWARD THIS EVENING ALLOWING COLDER AND
DRIER LOW LEVEL AIR TO ADVECT SOUTHEASTWARD. A VORT MAX ACROSS
EASTERN IOWA/NORTHWEST ILLINOIS WILL LIFT INTO LOWER MICHIGAN
LATER THIS EVENING WHICH SHOULD LEAD TO SOME ENHANCEMENT OF LOW
LEVEL FRONTOGENESIS ACROSS THE AREA THIS EVENING AND SLOW WEST TO
EAST PROGRESSION OF BACK EDGE OF PRECIP. CHANGEOVER BACK TO SNOW
EXPECTED AT KFWA AROUND THE 01Z TIMEFRAME...WITH A BRIEF PERIOD OF
SOME SLEET POSSIBLE EARLY THIS EVENING. A QUICK COUPLE OF INCHES
OF SNOW COULD FALL AT KFWA THIS EVENING DEPENDING ON EXACT TIMING
OF CHANGEOVER AND ORIENTATION OF POTENTIAL FRONTOGENESIS BANDS...BUT
CONFIDENCE IN ACCUMULATIONS AT KFWA ARE QUITE LOW AT THIS TIME
GIVEN HIGH INITIAL WET BULB TEMPS. BULK OF PRECIP SHOULD SHIFT
EAST OF KFWA AFTER 06Z. IFR/TEMPO LIFR CONDS SHOULD IMPROVE TO
LOWER END MVFR OVERNIGHT...WITH FURTHER IMPROVEMENT EXPECTED ON
SUNDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 1 AM EST /MIDNIGHT CST/ SUNDAY FOR
INZ003>005-012-014.
MI...WINTER STORM WARNING UNTIL 1 AM EST SUNDAY FOR MIZ077>080.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MARSILI
SHORT TERM...FISHER
LONG TERM...T
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
406 PM EST SAT FEB 1 2014
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED
BELOW.
&&
.SYNOPSIS...
ISSUED AT 406 PM EST SAT FEB 1 2014
RAIN WILL CHANGE BACK TO A WINTRY MIX AND THEN SNOW TONIGHT AS
COLDER AIR RETURNS WITH THE PASSAGE OF A FRONTAL BOUNDARY. HIGH
PRESSURE WILL TRACK THROUGH THE REGION WITH COLD DRY WEATHER FOR THE
EARLY PART OF THE WEEK. A LARGE STORM SYSTEM WILL TRACK THROUGH THE
OHIO VALLEY TUESDAY AND WEDNESDAY...BRINGING THE POTENTIAL FOR
ACCUMULATING SNOW AND ICE. AFTER A BRIEF RESPITE...YET ANOTHER STORM
MAY BRING MORE SNOW FOR FRIDAY AND SATURDAY.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 406 PM EST SAT FEB 1 2014
RAIN SHOWERS CONTINUE TO IMPACT THE NORTHWEST HALF OF THE FORECAST
AREA THIS AFTERNOON. QUITE THE TEMPERATURE GRADIENT AT 20Z AS WARM
ADVECTION HAS DRAWN MUCH WARMER AIR INTO THE OHIO VALLEY. TEMPS
RANGED FROM THE MID/UPPER 30S OVER THE NORTHERN WABASH VALLEY TO THE
LOWER 50S OVER FAR SOUTHERN COUNTIES.
STARTING OFF A NEW MONTH WITH THE SAME OLD STORY...ANOTHER SHOT OF
WINTRY WEATHER TONIGHT AS COLDER AIR SPILLS BACK INTO CENTRAL
INDIANA BEHIND A COLD FRONT. THE FRONT WILL MOVE SOUTHEAST ACROSS
THE FORECAST AREA TONIGHT BUT AT A SLOW PACE AS THE BOUNDARY BECOMES
NEARLY STATIONARY TO THE MEAN UPPER FLOW. THE RESULT FROM THIS WILL
BE FOR NEAR SURFACE COOLING TO COMMENCE AT A FASTER PACE THAN THE
ADVECTION OF BOUNDARY LAYER COOLING OVER THE PRECIP SHIELD BEGINNING
OVER THE NORTHWEST THIS EVENING...EXPANDING SOUTHEAST ACROSS THE
FORECAST AREA OVERNIGHT.
LOW LEVEL THERMAL PROFILES BECOMING INCREASINGLY SUPPORTIVE OF A
MESSIER TRANSITION PERIOD OF 1-3 HOURS WITH A WINTRY MIX OF FREEZING
RAIN...SLEET AND SNOW BEFORE THE COLUMN COOLS ENOUGH TO SUPPORT ALL
SNOW. CURRENT HRRR EVEN HINTS AT THE POTENTIAL FOR SOME BANDING TO
SNOW OVER NORTHWEST COUNTIES THIS EVENING WHICH MAY SERVE TO
TRANSFER TO SNOW MORE QUICKLY AND PRODUCE ACCUMS OF 1 TO 2 INCHES
WITH EVEN LOCALLY HIGHER AMOUNTS ACROSS THE NORTHERN WABASH VALLEY.
FURTHER SOUTH AND EAST...EXPECT LIGHT ACCUMS OF ICE AND SNOW. OTHER
THAN FAR SOUTHEAST COUNTIES... EXPECT PRECIP FALLING AS ALL SNOW
OVER MOST AREAS AFTER 08-09Z. LIGHT SNOW WILL END FROM THE NORTHWEST
LATE TONIGHT.
HAVE CHOSEN TO ISSUE AN SPS FOR TONIGHT TO HIGHLIGHT THE LIGHT
SNOW/ICE ACCUMS AND POTENTIAL FOR SLICK SPOTS WITH REFREEZING AS
TEMPS FALL. AT THIS POINT...UNCERTAINTY REMAINS JUST TOO HIGH TO
WARRANT ISSUING AN ADVISORY AS TIMING OF THE CHANGEOVER AND EXTENT
OF TIME A CERTAIN PRECIP TYPE FALLS WILL BE CRITICAL IN DETERMINING
SNOW AND ICE AMOUNTS. EVENING SHIFT WILL CONTINUE TO MONITOR AND
ADJUST AS NEEDED.
TEMPS...USED NAM HOURLIES FOR TEMPS OVER THE NEXT SEVERAL HOURS AS
THEY FALL IN THE WAKE OF THE FRONTAL PASSAGE. MOS GUIDANCE LOOKED
REASONABLE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
ISSUED AT 406 PM EST SAT FEB 1 2014
FORECAST CHALLENGES FOCUS ON POPS FOR SUNDAY AS FRONTAL BOUNDARY
SLOWLY SAGS SOUTH THROUGH THE OHIO VALLEY. IN ADDITION...A SECONDARY
WAVE WILL TRACK ALONG THE FRONT OVER THE TENNESSEE AND LOWER OHIO
VALLEYS SUNDAY NIGHT AND EARLY MONDAY. MODEL GUIDANCE CONTINUES TO
SLOWLY SHIFT THE NORTHERN EDGE OF THE MOISTURE SHIELD NORTH...WITH
SOME SUGGESTIONS THAT LIGHT SNOW MAY MANAGE TO GET NORTH OF THE OHIO
RIVER AND INTO FAR SOUTHERN INDIANA FOR A PERIOD OF TIME SUNDAY
NIGHT. WHILE THE SLOWER DEPARTURE OF THE FRONT WILL WARRANT
LINGERING POPS OVER THE SOUTHEAST HALF OF THE FORECAST AREA SUNDAY
MORNING...WILL MAINTAIN DRY FORECAST FROM EARLY AFTERNOON SUNDAY ON
WITH DEEPER FORCING AND MOISTURE ASSOCIATED WITH THE WAVE REMAINING
ALONG AND SOUTH OF THE OHIO RIVER. ANY ADDITIONAL SHIFTS NORTH
HOWEVER WITH FUTURE MODEL RUNS WILL LIKELY REQUIRE INTRODUCING LOW
CHANCES FOR SNOW SUNDAY NIGHT OVER FAR SOUTHERN COUNTIES.
A BROAD AREA OF HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE
WEST MONDAY MORNING AND SHOULD SERVE TO FINALLY PUSH THE FRONT
FURTHER SOUTH AND EAST AND AWAY FROM THE OHIO VALLEY. WITH MODEL
SOUNDINGS INDICATING PRESENCE OF SUBSIDENCE AND DRIER AIR ANTICIPATE
PLENTY OF SUNSHINE MONDAY. MID AND HIGH LEVEL CLOUD COVER WILL BEGIN
TO INCREASE FROM THE SOUTHWEST MONDAY NIGHT AS THE STORM SYSTEM THAT
WILL IMPACT THE REGION LATER ON TUESDAY INTO WEDNESDAY ORGANIZES
OVER TEXAS AND THE WESTERN GULF.
TEMPS...GENERALLY LEANED TOWARDS THE COLDER MAVMOS THROUGH THE
PERIOD WHICH MATCHED MORE CLOSELY WITH THE LOW LEVEL THERMALS. COULD
SEE QUITE THE TEMP GRADIENT NORTH TO SOUTH FOR LOWS SUNDAY
NIGHT...WITH LOWS NEAR ZERO IN THE NORTHERN WABASH VALLEY WHERE
SKIES WILL BE PARTLY CLOUDY AND THE POTENTIAL FOR A COUPLE INCHES OF
SNOW ON THE GROUND WOULD HELP TEMPS TUMBLE. CLOUD SHIELD FROM
SURFACE WAVE TRACKING TO THE SOUTH SUNDAY NIGHT WILL KEEP TEMPS UP A
BIT FROM I-70 SOUTH...POSSIBLY ONLY FALLING TO AROUND 20 IN THE
EXTREME SOUTH.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
ISSUED AT 257 PM EST SAT FEB 1 2014
FOCUS REMAINS POSSIBLE WINTER STORM TUESDAY INTO WEDNESDAY.
CONTINUE TO PREFER A BLEND OF GUIDANCE WITH LESS RELIANCE ON
SOMEWHAT LESS CONSISTENT GFS. GFS LOW TRACK HAS SHIFTED SLIGHTLY
SOUTHEAST AND EURO SLIGHTLY NORTHWEST...ALTHOUGH EURO REMAINS
CONSISTENTLY THE COLDER MODEL AND GFS WARMER ODDLY ENOUGH. GFS
ENSEMBLE MEMBERS REMAIN LOOSELY CLUSTERED BUT AROUND A FURTHER
SOUTHEAST TRACK THAN PREVIOUS DAYS...BUT THIS HAS YET TO TRANSLATE
TO A COLDER SOLUTION IN THE LOW LEVELS.
AS SUCH...WILL CONTINUE WITH ALL SNOW MAINLY NORTH/NORTHWEST OF
INDY...WITH A CHANCE OF SLEET/FREEZING RAIN MIXING IN A SWATH
SOUTH OF THIS...AND FREEZING RAIN/SLEET WITH A CHANCE OF SNOW
ACROSS THE FAR SOUTH LATE TUESDAY INTO TUESDAY EVENING. ALL PRECIP
AFTER 06Z WEDNESDAY LIKELY SNOW OR QUICKLY TRANSITIONING TO SNOW.
MESOSCALE FEATURES WILL BE IN PLAY AND AS SUCH AMOUNTS REMAIN VERY
DIFFICULT TO PINPOINT. BANDING WILL BE AN ISSUE WHICH COULD IMPACT
BOTH AMOUNTS AND PRECIP TYPE OWING TO DYNAMIC EFFECTS.
MESSAGE REMAINS THE SAME. CENTRAL INDIANA RESIDENTS SHOULD BE
PREPARED FOR A POSSIBLE WINTER STORM BEGINNING TUESDAY AND
CONTINUING INTO EARLY WEDNESDAY WITH THE POTENTIAL FOR
ACCUMULATING SNOW AND SLEET/ICE.
&&
.AVIATION /DISCUSSION FOR THE 01/21Z KIND TAF UPDATE/...
ISSUED AT 333 PM EST SAT FEB 1 2014
MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS. NO
OTHER CHANGES NEEDED AT THIS TIME. PREVIOUS AVIATION DISCUSSION
FOLLOWS...
FLUCTUATING MVFR/IFR CONDITIONS IN PRECIP THIS AFTERNOON APPEAR
LIKELY TO DETERIORATE TO WIDESPREAD IFR AND PERHAPS LIFR AS LOW
PRESSURE PASSES THROUGH THE AREA AND DRAGS THE FRONTAL BOUNDARY
THROUGH THE SITES THIS EVENING.
FORECAST SOUNDINGS INDICATE THAT THERE MAY BE A FEW HOUR PERIOD OF
MIXED PRECIPITATION AS THE FRONT MOVES THROUGH THE AREA AND COLD
ADVECTION BEGINS AGAIN. THIS WILL LIKELY START AROUND 22-00Z AT
LAF...02-03Z IND/HUF...AND AROUND 04-05Z AT BMG.
WINDS WILL BECOME NORTHWESTERLY/NORTHERLY AND CHANGEOVER TO SNOW
WILL COMPLETE IN THOSE FEW HOURS...AND CONDITIONS WILL BECOME
WIDESPREAD IFR OR WORSE. SNOW WILL END NEAR DAYBREAK MOST SITES..
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM...NIELD
AVIATION...NIELD/JH
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FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
339 PM EST SAT FEB 1 2014
.SYNOPSIS...
ISSUED AT 537 AM EST SAT FEB 1 2014
LOW PRESSURE WILL TRACK THROUGH NORTHERN INDIANA TODAY BRINGING
HEAVY SNOW TO NORTHWEST INDIANA AND FAR SOUTHWEST LOWER MICHIGAN.
FARTHER SOUTHEAST A WINTRY MIX WILL OCCUR. AREAS...GENERALLY
ALONG AND SOUTHEAST OF A MONTICELLO...WARSAW...ANGOLA INDIAN TO
HILLSDALE MICHIGAN LINE WILL LIKELY SEE ALL THE PRECIPITATION
CHANGE OVER TO RAIN THIS AFTERNOON. A TRANSITION BACK TO A LIGHT
WINTRY MIX IS THEN EXPECTED AS THE STORM SYSTEM QUICKLY DEPARTS
INTO SOUTHEAST MICHIGAN. ANOTHER STORM SYSTEM IS THEN EXPECTED TO
AFFECT PORTIONS OF THE GREAT LAKES AND OHIO VALLEY REGION BY NEXT
TUESDAY AFTERNOON INTO WEDNESDAY.
&&
.SHORT TERM...(THROUGH TONIGHT)
ISSUED AT 337 PM EST SAT FEB 1 2014
...MESSY AFTERNOON/EVENING ON TAP FOR THE AREA...
AS OF 230 PM...LOCATIONS SOUTH OF A KANKAKEE...TO GOSHEN TO ANGOLA
LINE WERE SEEING ALL RAIN AS TEMPERATURES WERE IN THE MIDDLE 30S TO
NEAR 40 (FAR SOUTHEAST). PRIOR TO MIXING/SWITCHOVER...NUMEROUS
REPORTS OF 3 TO 5 INCHES OF SNOW CAME IN ACROSS THE WARNING AREA
WITH ANYWHERE FROM 1 TO 4 INCHES. BROAD AREA OF LOW PRESSURE WAS
LOCATED SOMEWHERE NEAR WHITE COUNTY...A BIT FURTHER NORTHWEST THAN
EXPECTED. RUC HAS BEEN HANDLING MANY OF THE FINER DETAILS QUITE WELL
AND WAS USED ALMOST EXCLUSIVELY FOR THE FORECAST INTO THIS EVENING.
THE LOW SHOULD TRACK ACROSS THE CENTRAL PORTIONS OF THE CWA BUT
ALSO SHOWING A FASTER TREND SO PREVIOUSLY THOUGHT CHANGE OVER TIMES
STILL LOOK REASONABLE. AS THE TRANSITION COMMENCES A BRIEF PERIOD OF
SLEET/FREEZING RAIN MAY OCCUR. ONCE THIS OCCURS...SEVERAL HOURS OF
SNOW IS EXPECTED WITH ADDITIONAL QPF VALUES OF ROUGHLY ONE QUARTER
INCH OR SO IN FAR NW AREAS TO A BAND OF THREE QUARTERS OF AN INCH OR
MORE IN SE HALF OR SO. MUCH OF THIS HEAVIER PRECIP WILL FALL IN THE
FORM OF RAIN...BUT MUCH LIKE FURTHER NW A QUARTER TO THIRD OF AN
INCH WILL LIKELY FALL AS SNOW. JUST AS WAS THE CASE EARLIER
TODAY...TOO MUCH UNCERTAINTY CONTINUES IN TRANSITION TO WARRANT ANY
HEADLINE CHANGES. IT COULD BE CLOSE FOR FULL WARNING CRITERIA BEING
MET IN SOME AREAS...BUT WARNING WAS ISSUED FOR A COMBINATION OF
EARLIER SNOW AND EXPECTED SNOW BEHIND THE LOW SO SHOULD WORK OUT FOR
THE MOST PART. FURTHER UPDATES AND REFINEMENTS ARE LIKELY INTO THIS
EVENING. NEEDLESS TO SAY...ONCE TEMPS START TO FALL..ROAD CONDITIONS
WILL BECOME MESSY AND VERY SLIPPERY WELL INTO THE OVERNIGHT HOURS.
&&
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 337 PM EST SAT FEB 1 2014
ENERGETIC IMPULSE LADEN FLW EMBEDDED WITHIN PROJECTED NEG PNA PATTN
ACRS NOAM SPELLS HIGH IMPACT WX ACRS THE OH VALLEY THIS PD. OF NOTE
CONTS TO BE W/SYS SEEN THIS AFTN ON VAPOR OUT NR 42N/137W WHICH DIGS
SEWD INTO NRN BAHA ON MON AND THEN LIFTS OUT THROUGH THE LWR OH
VALLEY AS LARGER SCALE ARCTIC STREAM SW DROPS SWD INTO THE WRN US.
PRONOUNCED POLAR RIDGING BLDG IN WAKE OF SHRT TERM SYS PASSAGE TO
PROVIDE A BRIEF DRY BUT COLD RESPITE FROM WINTERS ONSLAUGHT. HWVR
DEEP SRN PLAINS EJECTION POINT AND STG GOMEX RTN FLW INTO SRN
PERIPHERY OF RETREATING SFC RIDGE LOOK TO PROVIDE FOR SIG CYCLONE
DVLPMNT OVR THE LWR MS VALLEY EARLY TUE AND UP THROUGH THE ERN OH
VALLEY ON WED AS EXEMPLIFIED IN STABLE SPECTRAL TRACK. DETAILS AS
YET TO BE IRONED OUT BUT SIG IMPACTS XPCD BOTH W/WIND AND SNOW
PARTICULARLY TUE AFTN-WED AM.
OTRWS ARCTIC RIDGE BLDS EWD OUT OF THE PLAINS THU-FRI W/VERY COLD
TEMPS YET LOOKS TO SET THE STAGE FOR YET ANOTHER SIG OH VALLEY
CYCLONE NXT WEEKEND AS DEEP WRN TROUGH RELOADS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1236 PM EST SAT FEB 1 2014
ATTN THIS PD FOCUSED ON NEWD TRANSLATION OF UPSTREAM EMBEDDED JET
MAXIMA ALOFT OVR SWRN MO THIS AFTN. VIGOROUS LL WWA STILL IN
PROGRESS EWD OF EJECTING FLAT SFC WAVE OVR ERN IL AND YIELDING
WIDESPREAD IFR CONDS IN MOD-HVY PCPN ACRS THE TERMINALS. WARM NOSE
HAD PUSHED WELL NORTH OF KFWA BUT HOLDING JUST SOUTH OF KSBN AND XPC
LTL CHG THROUGH MID AFTN. HWVR RAPID LL CAA XPCD TO DVLP IN WAKE OF
NEWD PROGRESSING SFC WAVE WHICH WILL RESULT IN A CHG OVR BACK TO
SNOW THIS EVENING AT KFWA. IN FACT VIGOROUS MID LVL DEFORMATION
XPCD TO DVLP ALOFT THIS EVENING SWD OF EJECTING SPD MAX THROUGH THE
SRN LAKES AND LEAD TO SVRL HR PD OF MOD-HVY SNOW AT KFWA THIS EVENING
AND KSBN THIS AFTN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 1 AM EST /MIDNIGHT CST/ SUNDAY FOR
INZ003>005-012-014.
WINTER WEATHER ADVISORY UNTIL 1 AM EST SUNDAY FOR INZ006>008-013-
015-016-020-022.
MI...WINTER STORM WARNING UNTIL 1 AM EST SUNDAY FOR MIZ077>080.
WINTER WEATHER ADVISORY UNTIL 1 AM EST SUNDAY FOR MIZ081.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MURPHY
SHORT TERM...FISHER
LONG TERM...T
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1237 PM EST SAT FEB 1 2014
.SYNOPSIS...
ISSUED AT 537 AM EST SAT FEB 1 2014
LOW PRESSURE WILL TRACK THROUGH NORTHERN INDIANA TODAY BRINGING
HEAVY SNOW TO NORTHWEST INDIANA AND FAR SOUTHWEST LOWER MICHIGAN.
FARTHER SOUTHEAST A WINTRY MIX WILL OCCUR. AREAS...GENERALLY
ALONG AND SOUTHEAST OF A MONTICELLO...WARSAW...ANGOLA INDIAN TO
HILLSDALE MICHIGAN LINE WILL LIKELY SEE ALL THE PRECIPITATION
CHANGE OVER TO RAIN THIS AFTERNOON. A TRANSITION BACK TO A LIGHT
WINTRY MIX IS THEN EXPECTED AS THE STORM SYSTEM QUICKLY DEPARTS
INTO SOUTHEAST MICHIGAN. ANOTHER STORM SYSTEM IS THEN EXPECTED TO
AFFECT PORTIONS OF THE GREAT LAKES AND OHIO VALLEY REGION BY NEXT
TUESDAY AFTERNOON INTO WEDNESDAY.
&&
.UPDATE...
ISSUED AT 1013 AM EST SAT FEB 1 2014
SOME SIGNIFICANT CHANGES TO THE FORECAST TO UPGRADE PORTIONS OF
THE ADVISORY TO A WARNING AND EXTEND SOUTHERN EXTENT OF ADVISORY.
AS EXPECTED A MESSY SITUATION WAS UNFOLDING ACROSS THE REGION. ALL
SNOW WAS BEING REPORTED ACROSS NW QUARTER TO THIRD OF THE FORECAST
AREA WITH INCH PER HOUR RATES. SOCIAL MEDIA AND SPOTTER REPORTS
ALREADY SHOWING 3 TO 5 INCHES OF SNOW IN BOTH THE PREVIOUS AND NOW
EXTENDED WARNING AREA AND MORE TO COME. RAP HAD A STELLAR HANDLE
ON THERMAL PROFILES WITH ALL RAIN NOW BEING REPORTED NEAR AND
SOUTHEAST OF FT WAYNE AND A MIXTURE OF SNOW/SLEET/FREEZING RAIN
NORTHWEST OF THIS AREA. AT THE OFFICE WE ENCOUNTERED A PERIOD OF
SILVER DOLLAR SIZE FLAKES THAT QUICKLY ACCUMULATED A FEW INCHES OF
SNOW. REFLECTIVITY VALUES ON THE RADAR ARE CRAZY WITH SOME PUSHING
50 DBZ AS MELTING LAYER AND VERY WET SLEET/SNOWFLAKES BEING PICKED
UP. CHANGES WERE MADE IN SFC TEMPS AND QPF WITH SNOW NOW EXPECTED
MUCH OF THE DAY ALONG AND NORTHWEST OF A LINE FROM KNOX TO ELKHART
TO COLDWATER AND A MIXTURE SOUTHEAST OF THIS LINE AND NORTHWEST OF
A LOGANSPORT TO FORT WAYNE TO NAPOLEON LINE. SOUTHEAST OF THIS
FINAL LINE PRECIP SHOULD REMAIN ALL RAIN INTO LATE AFTERNOON.
WHILE TEMPS ARE ABOVE FREEZING IN SE AREAS LAW ENFORCEMENT
OFFICIALS ARE REPORTING ICING STILL OCCURRING DESPITE TEMPS OF 33
TO 36 DEGREES AS EXTREMELY COLD SURFACES WERE STRUGGLING TO
WARM...AS I HAD FEARED YESTERDAY. ADVISORY HAS BEEN EXTENDED TO
18Z TO GIVE TIME FOR THE ICE TO MELT OFF AND WILL RECONSIDER
HEADLINES IN A FEW HOURS.
WHILE UPSTREAM RADAR TRENDS DO DECREASE...RUC INDICATES A
REDEVELOPMENT OF PRECIP AS CONVECTION ACROSS CENTRAL INDIANA MOVES
EAST AND ALLOWS BETTER FLOW OF THETA E BACK INTO THE AREA. WILL
NEED TO WATCH CHANGE OVER LATER TODAY INTO THIS EVENING THAT COULD
CAUSE FURTHER ISSUES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 537 AM EST SAT FEB 1 2014
A SURFACE LOW OVER NW ARKANSAS WILL RACE NORTHEAST INTO THE
WESTERN GREAT LAKES REGION TODAY. LOW LEVEL MOISTURE FLUX FROM THE
SOUTHWEST WILL INCREASE RAPIDLY WITH SIGNIFICANT LIFT INDICATED ON
THE 290K NAM ISENTROPIC SFC. HAVE BLENDED A NUMBER OF MODELS
YIELDING A SFC LOW TRACK FROM SOUTH OF LAF TO NEAR TOL. THERE WILL
BE A TIGHT THERMAL GRADIENT IN THE LOW LEVELS ACROSS THE AREA. THE
NAM BUFKIT PROFILE AT AOH SHOWS THE WARM LAYER AT 5C...WHICH WILL
BE SUFFICIENT TO MELT ALL THE SNOW IN THE LOWER LAYERS DURING THE
MIDDLE OF THE DAY. HOWEVER... THE LATEST NAM/06Z RUN KEEPS SBN ALL
SNOW WITH THE ENTIRE PROFILE BELOW 0C. A TIER OF COUNTIES
SOUTHWEST OF THE WARNING MAY NEED TO BE UPGRADED IF THE PROFILE IS
NOT WARM ENOUGH TO MIX AT SBN. CONCERN FOR A FOOT OF SNOW THERE
WITH 295K ISENTROPIC SFC PUSHING 6 G/KG. THE GARCIA METHOD HAS
WORKED VERY WELL WITH THE PAST 2 BIG SNOW EVENTS HERE
RECENTLY...AND NOW SHOWS SNOW AMOUNT COULD BE NEAR A FOOT OVER FAR
SW LOWER MICH INTO NRN INDIANA. CROSS SECTIONS SHOW EQUIV POT VORT
VERY FAVORABLE FOR MESOBANDING WITH THE DENDRITIC GROWTH ZONE
RIGHT THROUGH THE MIDDLE OF MAX LIFT WITH SIGNIFICANT
FRONTOGENESIS BELOW THE EPV. IN THE SHORTER TERM...INCREASING SFC
PRESSURE FALLS OVER NE IL INDICATED WARM AIR ADVECTION WAS
INCREASING...WHICH IS ALSO REFLECTED ON KLOT AND KILX VAD WIND
PROFILES. PRECIPITATION SHOULD BECOME MIXED...AND THEN CHANGE TO
JUST RAIN WERE SFC TEMPERATURES RISE ABOVE FREEZING.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 537 AM EST SAT FEB 1 2014
QUIET/NIL SENSIBLE WX FOR SUN/MON AS SWRN CANADIAN ANTICYCLONE
SPILLS ALONG SEWD ACRS HIGH PLAINS AND INTO CNTL CONUS DY2...SRN
GRTLKS/MID MS VLY ON DY3. LARGE BREADTH OF DRY/COLD/SUBSIDENT
AIRMASS SUGGESTS SOME GAINS MADE WITH CONTD TREND OF SLIGHTLY COLDER
MIN TEMPS AND CERTAINLY A MORE RAPID EVENING PLUMMET.
LEAD UPSTREAM WAVE /SUBSEQUENT TO NEAR TERM CONSIDERATIONS/IN
VIGOROUS NRN STREAM REGIME TO DIG EWD THROUGH AZ/MM IN HIGHLY
POSITIVE TILT FASHION...WITH SFC CYCLOGENESIS SEQUESTERED WELL SOUTH
ALONG SRN GULF SUN/MON. DECISIVELY/PERSISTENT SPECTRAL MODEL
CONSISTENCY WRT STRONG CNTL PAC VORTEX TO IMPINGE ON NRN CAL
COASTLINE BY F48...THEREAFTER PHASING WITH NRN BC AND POLEWARD
VORTICIES DYS3/4. OPTIMAL GOMEX FEED PRESENTS BY MIDDAY TUE WITH
WIDE BREADTH OF 1000-850 MB MIXING RATIOS GTE 4 G/KG FM SRN PLAINS
THROUGH OZARKS EWD THROUGH OHIO VLY TO MIDATL RGN. GIVEN INITIAL
HIGH 925MB CPDS OF 200-300 MB ACRS CWA DAYBREAK TUE HAVE SHIFTED
TIMING OF EVENT START/HIR POPS TO LATTER HALF OF DAY...CULMINATING
WITH BULK OF SNOW EVENT SET FOR OVERNIGHT PD FOLLOWED WITH SOME
TEMPORAL DETAIL OF PULLOUT WED. STORM TRACK CLUSTERING FM LA MIDDAY
TUE THROUGH TN VLY TO UPR OH VLY/SWRN PA BY 12 UTC WED. GFS COBB
GIVES INKLING OF SIG SNOW EVENT AND WILL CONT TO HIGHLIGHT IN HWO.
WHILE STRICTLY COBB TOTALS ATTM MIGHT SUGGEST RATHER LOW CONFIDENCE
OF EVENTUAL WARNING EVENT/GTE 8 INCHES/24 HRS WITH 4.5-5.5 DAY
EVENT...CERTAINLY I285-290K ISENT ASCENT/MOISTURE TAP/OPPOSITIONAL
PRE/POST SYSTEM RELATIVE FLOW AND DEEP/WEAK STATIC STABILITY WITHIN
UVM PROFILES...ALL BELIES POTNLY SIG AMOUNTS AND BEGS CLOSE ATTN TO
SUBSEQUENT MODEL EVOLUTION. HINT OF GFS I290K TROWAL DEVELOPMENT
ALSO OF NOTE...ESPCLY SHOULD LATER HIR RES MODELS TARGET SIMILARLY.
IN WAKE OF SYSTEM...FAVOR COLDER/LOWER END GUIDANCE AS BROAD NRN
CONUS TROFFING TO AFFORD LONG LIVED ARCTIC AIRMASS TO SPILL FM NRN
HIGH PLAINS INTO ERN CONUS. HAVE QUELLED POPS LATE IN FCST PD WITH
DISCREPANCIES OF EVENTUAL SEWD KICK OF NRN INTMTN REGN STORM
SYSTEM...MORE LIKELY DY8 BYND GIVEN SYSTEM APPEARS CUTOFF INTO LATE
NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1236 PM EST SAT FEB 1 2014
ATTN THIS PD FOCUSED ON NEWD TRANSLATION OF UPSTREAM EMBEDDED JET
MAXIMA ALOFT OVR SWRN MO THIS AFTN. VIGOROUS LL WWA STILL IN
PROGRESS EWD OF EJECTING FLAT SFC WAVE OVR ERN IL AND YIELDING
WIDESPREAD IFR CONDS IN MOD-HVY PCPN ACRS THE TERMINALS. WARM NOSE
HAD PUSHED WELL NORTH OF KFWA BUT HOLDING JUST SOUTH OF KSBN AND XPC
LTL CHG THROUGH MID AFTN. HWVR RAPID LL CAA XPCD TO DVLP IN WAKE OF
NEWD PROGRESSING SFC WAVE WHICH WILL RESULT IN A CHG OVR BACK TO
SNOW THIS EVENING AT KFWA. IN FACT VIGOROUS MID LVL DEFORMATION
XPCD TO DVLP ALOFT THIS EVENING SWD OF EJECTING SPD MAX THROUGH THE
SRN LAKES AND LEAD TO SVRL HR PD OF MOD-HVY SNOW AT KFWA THIS EVENING
AND KSBN THIS AFTN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
INZ006>009-013-015>018-020-022>027-032>034.
WINTER STORM WARNING UNTIL 10 PM EST /9 PM CST/ THIS EVENING FOR
INZ003>005-012-014.
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ081.
WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MIZ077>080.
OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ001-
002-004-005-015-016-024-025.
LM...NONE.
&&
$$
UPDATE...FISHER
SYNOPSIS...MURPHY
SHORT TERM...SKIPPER
LONG TERM...MURPHY
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1023 AM EST SAT FEB 1 2014
.SYNOPSIS...
ISSUED AT 537 AM EST SAT FEB 1 2014
LOW PRESSURE WILL TRACK THROUGH NORTHERN INDIANA TODAY BRINGING
HEAVY SNOW TO NORTHWEST INDIANA AND FAR SOUTHWEST LOWER MICHIGAN.
FARTHER SOUTHEAST A WINTRY MIX WILL OCCUR. AREAS...GENERALLY
ALONG AND SOUTHEAST OF A MONTICELLO...WARSAW...ANGOLA INDIAN TO
HILLSDALE MICHIGAN LINE WILL LIKELY SEE ALL THE PRECIPITATION
CHANGE OVER TO RAIN THIS AFTERNOON. A TRANSITION BACK TO A LIGHT
WINTRY MIX IS THEN EXPECTED AS THE STORM SYSTEM QUICKLY DEPARTS
INTO SOUTHEAST MICHIGAN. ANOTHER STORM SYSTEM IS THEN EXPECTED TO
AFFECT PORTIONS OF THE GREAT LAKES AND OHIO VALLEY REGION BY NEXT
TUESDAY AFTERNOON INTO WEDNESDAY.
&&
.UPDATE...
ISSUED AT 1013 AM EST SAT FEB 1 2014
SOME SIGNIFICANT CHANGES TO THE FORECAST TO UPGRADE PORTIONS OF
THE ADVISORY TO A WARNING AND EXTEND SOUTHERN EXTENT OF ADVISORY.
AS EXPECTED A MESSY SITUATION WAS UNFOLDING ACROSS THE REGION. ALL
SNOW WAS BEING REPORTED ACROSS NW QUARTER TO THIRD OF THE FORECAST
AREA WITH INCH PER HOUR RATES. SOCIAL MEDIA AND SPOTTER REPORTS
ALREADY SHOWING 3 TO 5 INCHES OF SNOW IN BOTH THE PREVIOUS AND NOW
EXTENDED WARNING AREA AND MORE TO COME. RAP HAD A STELLAR HANDLE
ON THERMAL PROFILES WITH ALL RAIN NOW BEING REPORTED NEAR AND
SOUTHEAST OF FT WAYNE AND A MIXTURE OF SNOW/SLEET/FREEZING RAIN
NORTHWEST OF THIS AREA. AT THE OFFICE WE ENCOUNTERED A PERIOD OF
SILVER DOLLAR SIZE FLAKES THAT QUICKLY ACCUMULATED A FEW INCHES OF
SNOW. REFLECTIVITY VALUES ON THE RADAR ARE CRAZY WITH SOME PUSHING
50 DBZ AS MELTING LAYER AND VERY WET SLEET/SNOWFLAKES BEING PICKED
UP. CHANGES WERE MADE IN SFC TEMPS AND QPF WITH SNOW NOW EXPECTED
MUCH OF THE DAY ALONG AND NORTHWEST OF A LINE FROM KNOX TO ELKHART
TO COLDWATER AND A MIXTURE SOUTHEAST OF THIS LINE AND NORTHWEST OF
A LOGANSPORT TO FORT WAYNE TO NAPOLEON LINE. SOUTHEAST OF THIS
FINAL LINE PRECIP SHOULD REMAIN ALL RAIN INTO LATE AFTERNOON.
WHILE TEMPS ARE ABOVE FREEZING IN SE AREAS LAW ENFORCEMENT
OFFICIALS ARE REPORTING ICING STILL OCCURRING DESPITE TEMPS OF 33
TO 36 DEGREES AS EXTREMELY COLD SURFACES WERE STRUGGLING TO
WARM...AS I HAD FEARED YESTERDAY. ADVISORY HAS BEEN EXTENDED TO
18Z TO GIVE TIME FOR THE ICE TO MELT OFF AND WILL RECONSIDER
HEADLINES IN A FEW HOURS.
WHILE UPSTREAM RADAR TRENDS DO DECREASE...RUC INDICATES A
REDEVELOPMENT OF PRECIP AS CONVECTION ACROSS CENTRAL INDIANA MOVES
EAST AND ALLOWS BETTER FLOW OF THETA E BACK INTO THE AREA. WILL
NEED TO WATCH CHANGE OVER LATER TODAY INTO THIS EVENING THAT COULD
CAUSE FURTHER ISSUES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 537 AM EST SAT FEB 1 2014
A SURFACE LOW OVER NW ARKANSAS WILL RACE NORTHEAST INTO THE
WESTERN GREAT LAKES REGION TODAY. LOW LEVEL MOISTURE FLUX FROM THE
SOUTHWEST WILL INCREASE RAPIDLY WITH SIGNIFICANT LIFT INDICATED ON
THE 290K NAM ISENTROPIC SFC. HAVE BLENDED A NUMBER OF MODELS
YIELDING A SFC LOW TRACK FROM SOUTH OF LAF TO NEAR TOL. THERE WILL
BE A TIGHT THERMAL GRADIENT IN THE LOW LEVELS ACROSS THE AREA. THE
NAM BUFKIT PROFILE AT AOH SHOWS THE WARM LAYER AT 5C...WHICH WILL
BE SUFFICIENT TO MELT ALL THE SNOW IN THE LOWER LAYERS DURING THE
MIDDLE OF THE DAY. HOWEVER... THE LATEST NAM/06Z RUN KEEPS SBN ALL
SNOW WITH THE ENTIRE PROFILE BELOW 0C. A TIER OF COUNTIES
SOUTHWEST OF THE WARNING MAY NEED TO BE UPGRADED IF THE PROFILE IS
NOT WARM ENOUGH TO MIX AT SBN. CONCERN FOR A FOOT OF SNOW THERE
WITH 295K ISENTROPIC SFC PUSHING 6 G/KG. THE GARCIA METHOD HAS
WORKED VERY WELL WITH THE PAST 2 BIG SNOW EVENTS HERE
RECENTLY...AND NOW SHOWS SNOW AMOUNT COULD BE NEAR A FOOT OVER FAR
SW LOWER MICH INTO NRN INDIANA. CROSS SECTIONS SHOW EQUIV POT VORT
VERY FAVORABLE FOR MESOBANDING WITH THE DENDRITIC GROWTH ZONE
RIGHT THROUGH THE MIDDLE OF MAX LIFT WITH SIGNIFICANT
FRONTOGENESIS BELOW THE EPV. IN THE SHORTER TERM...INCREASING SFC
PRESSURE FALLS OVER NE IL INDICATED WARM AIR ADVECTION WAS
INCREASING...WHICH IS ALSO REFLECTED ON KLOT AND KILX VAD WIND
PROFILES. PRECIPITATION SHOULD BECOME MIXED...AND THEN CHANGE TO
JUST RAIN WERE SFC TEMPERATURES RISE ABOVE FREEZING.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 537 AM EST SAT FEB 1 2014
QUIET/NIL SENSIBLE WX FOR SUN/MON AS SWRN CANADIAN ANTICYCLONE
SPILLS ALONG SEWD ACRS HIGH PLAINS AND INTO CNTL CONUS DY2...SRN
GRTLKS/MID MS VLY ON DY3. LARGE BREADTH OF DRY/COLD/SUBSIDENT
AIRMASS SUGGESTS SOME GAINS MADE WITH CONTD TREND OF SLIGHTLY COLDER
MIN TEMPS AND CERTAINLY A MORE RAPID EVENING PLUMMET.
LEAD UPSTREAM WAVE /SUBSEQUENT TO NEAR TERM CONSIDERATIONS/IN
VIGOROUS NRN STREAM REGIME TO DIG EWD THROUGH AZ/MM IN HIGHLY
POSITIVE TILT FASHION...WITH SFC CYCLOGENESIS SEQUESTERED WELL SOUTH
ALONG SRN GULF SUN/MON. DECISIVELY/PERSISTENT SPECTRAL MODEL
CONSISTENCY WRT STRONG CNTL PAC VORTEX TO IMPINGE ON NRN CAL
COASTLINE BY F48...THEREAFTER PHASING WITH NRN BC AND POLEWARD
VORTICIES DYS3/4. OPTIMAL GOMEX FEED PRESENTS BY MIDDAY TUE WITH
WIDE BREADTH OF 1000-850 MB MIXING RATIOS GTE 4 G/KG FM SRN PLAINS
THROUGH OZARKS EWD THROUGH OHIO VLY TO MIDATL RGN. GIVEN INITIAL
HIGH 925MB CPDS OF 200-300 MB ACRS CWA DAYBREAK TUE HAVE SHIFTED
TIMING OF EVENT START/HIR POPS TO LATTER HALF OF DAY...CULMINATING
WITH BULK OF SNOW EVENT SET FOR OVERNIGHT PD FOLLOWED WITH SOME
TEMPORAL DETAIL OF PULLOUT WED. STORM TRACK CLUSTERING FM LA MIDDAY
TUE THROUGH TN VLY TO UPR OH VLY/SWRN PA BY 12 UTC WED. GFS COBB
GIVES INKLING OF SIG SNOW EVENT AND WILL CONT TO HIGHLIGHT IN HWO.
WHILE STRICTLY COBB TOTALS ATTM MIGHT SUGGEST RATHER LOW CONFIDENCE
OF EVENTUAL WARNING EVENT/GTE 8 INCHES/24 HRS WITH 4.5-5.5 DAY
EVENT...CERTAINLY I285-290K ISENT ASCENT/MOISTURE TAP/OPPOSITIONAL
PRE/POST SYSTEM RELATIVE FLOW AND DEEP/WEAK STATIC STABILITY WITHIN
UVM PROFILES...ALL BELIES POTNLY SIG AMOUNTS AND BEGS CLOSE ATTN TO
SUBSEQUENT MODEL EVOLUTION. HINT OF GFS I290K TROWAL DEVELOPMENT
ALSO OF NOTE...ESPCLY SHOULD LATER HIR RES MODELS TARGET SIMILARLY.
IN WAKE OF SYSTEM...FAVOR COLDER/LOWER END GUIDANCE AS BROAD NRN
CONUS TROFFING TO AFFORD LONG LIVED ARCTIC AIRMASS TO SPILL FM NRN
HIGH PLAINS INTO ERN CONUS. HAVE QUELLED POPS LATE IN FCST PD WITH
DISCREPANCIES OF EVENTUAL SEWD KICK OF NRN INTMTN REGN STORM
SYSTEM...MORE LIKELY DY8 BYND GIVEN SYSTEM APPEARS CUTOFF INTO LATE
NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 642 AM EST SAT FEB 1 2014
CONTD FOCUS ON PRIAMRILY IFR MET CONDS ACRS NRN IN.. AT KSBN AS
HVR SNOW UPSTREAM ARRIVES SFC VSBYS TO PLUMMET. COLDER THERMAL
PROFILE COULD SUPPORT ALL SNOW AS PRIMARY PTYPE THROUGH THE DAY.
DEEPENING WARMER AIR ALOFT SHOULD HOWEVER PROVIDE CHANGEOVER AT
KFWA AROUND 14 UTC WITH ENTIRELY LIQUID BY ERLY AFTN...THEN
TRANSITIONING BACK THROUGH MIXED PRECIP AS COLDER AIR DRAWS IN
BEHIND SFC LOW AS IT TRACKS BTWN KSBN/KFWA THIS AFTN AND THEN INTO
SERN MI.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
INZ006>009-013-015>018-020-022>027-032>034.
WINTER STORM WARNING UNTIL 10 PM EST /9 PM CST/ THIS EVENING FOR
INZ003>005-012-014.
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ081.
WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MIZ077>080.
OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ001-
002-004-005-015-016-024-025.
LM...NONE.
&&
$$
UPDATE...FISHER
SYNOPSIS...MURPHY
SHORT TERM...SKIPPER
LONG TERM...MURPHY
AVIATION...MURPHY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
401 PM CST Sat Feb 1 2014
...Updated for long term discussion...
.SYNOPSIS...
ISSUED AT 1103 AM CST SAT FEB 1 2014
At 12z Saturday an upper level trough was located over northern
British Columbia and a closed upper low was located off the coast
of the Pacific Northwest. East of this closed upper low...50 to 70
meter 12hr 500mb height rises were observed along the west coast
of Northern California and Oregon. Further east a 500mb trough
extended from the Northern Plains to southwest Utah/northwest
Arizona. A 700mb baroclinic zone/area of deformation was located
ahead of this upper level trough and stretched from northeast New
Mexico to southern Iowa. A 850mb ridge axis was located across
western Kansas. 850mb temperatures at 12z Saturday ranged from -6c
at Dodge City to -12c at Rapid City, SD and the winds were
northerly at 20 to 30kts. At the surface a stationary front at 12z
was located from central Texas to southeast Missouri.
&&
.SHORT TERM...(This evening through Sunday)
ISSUED AT 156 PM CST SAT FEB 1 2014
RAP, NAM, and GFS were all in good agreement in keeping the 700mb
baroclinic zone nearly stationary through midnight as the upper
level trough approaches western Kansas. Moisture and frontogenesis
will be improving along this baroclinic zone early tonight which
will give way to a chance/slight chance for some light snow across
portions of southwest Kansas. Will therefore mention a chance of
light snow overnight along this baroclinic zone as the upper level
trough crosses the central plains. Any snow accumulations
overnight will be light and average less than one inch.
Breaks of sunshine can be expected by Sunday afternoon as
subsidence and drier air air returns to western Kansas behind the
upper level through that will be moving across eastern Kansas.
Temperatures will still be unseasonably cool based 850mb
temperatures at 00z Monday. Using this as a guide the highs on
Sunday are expected to generally range from the upper 20s to lower
30s.
.LONG TERM...(Sunday night through Saturday)
ISSUED AT 353 PM CST SAT FEB 1 2014
A long wave trough will be generally situated across central and
western North America through February 8th. Individual shortwave
troughs will progress around the southern periphery of the
longwave trough, resulting in periodic bouts of winter weather
for western Kansas. Also, a strong surge of arctic air will slowly
invade the central and northern plains by mid to late next week,
resulting in bitterly cold temperatures and wind chills.
An open shortwave trough will approach from the southwest by
Monday night and Tuesday. Isentropic lift ahead of this feature
should result in widespread snow, with several inches of
accumulation likely. The location of the heaviest snow will surely
change with each model run, and is just not possible to nail down
this far out. However, given that the system is open and fairly
progressive, the best chance for heavier snow should be from Dodge
City eastward, with lesser potential in far western Kansas.
After a seasonal day Sunday with highs in the 30s and 40s, cold
advection and evaporational cooling will result in highs
in the 20s by Tuesday. Much colder air by Wednesday and Thursday
will result in highs in the single digits and teens, especially
since the large scale pattern will be conducive to low level
upslope flow and low clouds. Thus, diurnal ranges should be
fairly small, with lows not getting too out of control due to cloud
cover. After a break Wednesday, isentropic upglide will redevelop
by Wednesday night and persist into early Friday ahead of the next
upper level trough, resulting in areas of light accumulating snow
that will just add to what will already be on the ground. Temperatures
will remain cold through Friday and Saturday. Even after Saturday,
given the snow cover, temperatures will be very slow to moderate.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1103 AM CST SAT FEB 1 2014
12z BUFR soundings and 14z HRRR indicating MVFR ceilings can be
expected this afternoon as 900mb to 850mb moisture improves across
western Kansas. These MVFR ceiling will give way to VFR conditions
after 03z as an area of high pressure at the surface builds into
the area from the north and the area of low level moisture moves
south/southwest into southeast Colorado and northern Oklahoma.
North to northeast winds will be at 10 to 15kts today and then
subside to 10kts or less after 00z Sunday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 9 30 14 38 / 10 0 10 10
GCK 7 29 14 40 / 20 10 10 10
EHA 12 31 17 44 / 20 10 10 10
LBL 11 31 16 42 / 20 10 10 10
HYS 5 28 12 35 / 10 0 10 10
P28 13 30 15 39 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Burgert
LONG TERM...Finch
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
158 PM CST Sat Feb 1 2014
...Updated short term discussion...
.SYNOPSIS...
ISSUED AT 1103 AM CST SAT FEB 1 2014
At 12z Saturday an upper level trough was located over northern
British Columbia and a closed upper low was located off the coast
of the Pacific Northwest. East of this closed upper low...50 to 70
meter 12hr 500mb height rises were observed along the west coast
of Northern California and Oregon. Further east a 500mb trough
extended from the Northern Plains to southwest Utah/northwest
Arizona. A 700mb baroclinic zone/area of deformation was located
ahead of this upper level trough and stretched from northeast New
Mexico to southern Iowa. A 850mb ridge axis was located across
western Kansas. 850mb temperatures at 12z Saturday ranged from -6c
at Dodge City to -12c at Rapid City, SD and the winds were
northerly at 20 to 30kts. At the surface a stationary front at 12z
was located from central Texas to southeast Missouri.
&&
.SHORT TERM...(This evening through Sunday)
ISSUED AT 156 PM CST SAT FEB 1 2014
RAP, NAM, and GFS were all in good agreement in keeping the 700mb
baroclinic zone nearly stationary through midnight as the upper
level trough approaches western Kansas. Moisture and frontogenesis
will be improving along this baroclinic zone early tonight which
will give way to a chance/slight chance for some light snow across
portions of southwest Kansas. Will therefore mention a chance of
light snow overnight along this baroclinic zone as the upper level
trough crosses the central plains. Any snow accumulations
overnight will be light and average less than one inch.
Breaks of sunshine can be expected by Sunday afternoon as
subsidence and drier air air returns to western Kansas behind the
upper level through that will be moving across eastern Kansas.
Temperatures will still be unseasonably cool based 850mb
temperatures at 00z Monday. Using this as a guide the highs on
Sunday are expected to generally range from the upper 20s to lower
30s.
.LONG TERM...(Sunday through Friday)
ISSUED AT 344 AM CST SAT FEB 1 2014
The Monday Night-Tuesday storm continues to be the main focus of the
forecast. The global models are coming into a bit better focus
tracking a mid-level potential vorticity (PV) anomaly from southern
California early Monday to far southwest New Mexico by late Monday
Night...and lifting northeast through West Texas and into western
Oklahoma by midday Tuesday. This is a favorable track for southwest
Kansas moderate-heavy precipitation. The complicating factor will
be moisture return...as moisture will be poor across Texas. By early
Tuesday, Gulf of Mexico moisture will finally be taken in by the
mid-latitude cyclone and that is when moderate to heavy
precipitation rates will increase. From a timing standpoint, the
southwest Kansas region will be on the southwest periphery of the
storm by the time adequate moisture becomes involved. Despite the
moisture deficiency for at least half of the event, we are still
looking at a solid 3 to 6 inch event across much of the forecast
area from late Monday Night into Tuesday Afternoon. Strong cold air
advection in the low levels will occur by midday Tuesday, and the
increased pressure rises and gradient will result in an increase in
north surface winds. Wind speeds of 18 to 22 knots sustained will
likely occur by afternoon, especially west of highway 183, and
blowing/drifting snow will likely become an issue. We added some
areas blowing snow in the grids for the afternoon portion of the
Tuesday period.
In other areas of the forecast, Sunday Night and Monday temperatures
were increased given the increase in southerly winds and low level
warm advection ahead of the approaching storm. In fact, Monday could
be quite mild especially across the far southwest region with some
highs in the mid 40s possible in the Elkhart and Liberal areas.
Following the storm, the ECMWF model is suggesting some bitterly
cold temperatures Wednesday and Thursday with 850mb temperatures in
the -17 to -21F range. The fresh arctic airmass and expected snow
cover will lead to limited modification of the airmass. The latest
AllBlend guidance had highs in the mid teens for both Wednesday and
Thursday...and this may be too warm! We went ahead and lowered
these a couple degrees, especially considering that the ECMWF model
is suggesting highs both days in the single digits along and north
of the Arkansas River. We should see at least one night with lows
below zero. With snow cover, this could be setting up for the
coldest days/nights of the winter thus far.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1103 AM CST SAT FEB 1 2014
12z BUFR soundings and 14z HRRR indicating MVFR ceilings can be
expected this afternoon as 900mb to 850mb moisture improves across
western Kansas. These MVFR ceiling will give way to VFR conditions
after 03z as an area of high pressure at the surface builds into
the area from the north and the area of low level moisture moves
south/southwest into southeast Colorado and northern Oklahoma.
North to northeast winds will be at 10 to 15kts today and then
subside to 10kts or less after 00z Sunday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 9 30 14 36 / 10 0 10 10
GCK 7 29 14 38 / 10 10 10 10
EHA 12 31 17 42 / 20 10 10 10
LBL 11 31 16 40 / 20 10 10 10
HYS 5 28 12 33 / 10 0 10 10
P28 13 30 15 37 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Burgert
LONG TERM...Umscheid
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS WICHITA KS
1143 AM CST SAT FEB 1 2014
.UPDATE...
ISSUED AT 1101 AM CST SAT FEB 1 2014
CURRENT SATELLITE IMAGERY SHOWS SOME CLOUD ENHANCEMENTS FROM UPPER
JET DYNAMICS SPREADING ACROSS SOUTHERN KANSAS...AND LOOKING AT
TRENDS OF LOCAL RADAR VAD WIND PROFILERS ECHOS IN THE MID-LEVELS
WERE GRADUALLY WORKING DOWNWARD. THIS COULD GIVE WAY TO A SEEDER-
FEEDER PROCESS IN THE ATMOSPHERE AND GENERATE SOME LIGHT SNOW OR
FLURRIES ACROSS SOUTHERN KANSAS FOR THE AFTERNOON HOURS...AND
LINGER INTO THE EVENING HOURS. A TRACE TO A LIGHT DUSTING OF SNOW
IS POSSIBLE WITH THIS ACTIVITY.
JAKUB
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 328 AM CST SAT FEB 1 2014
TODAY:
THE MIXED PRECIPITATION IS EXPECTED TO COME TO AN END THIS MORNING.
THE LATEST GUIDANCE HAS THE BULK OF THE PRECIPITATION EXITING INTO
MISSOURI NOT LONG AFTER THIS ISSUANCE...AND ON THE WHOLE THAT LOOKS
TO BE CLOSE TO WHAT IS OCCURRING. A DOWNWARD TREND IN PRECIPITATION
IS BEING OBSERVED AS OF THIS ISSUANCE...AND EXPECT THAT TO PERSIST.
ANY RESIDUAL PRECIPITATION WILL CONTINUE TO BE A MIX. THE LAST FEW
RUNS OF THE HRRR DEVELOP A BAND OF PRECIPITATION DURING THE
AFTERNOON HOURS OVER SOUTH CENTRAL KANSAS...BUT THIS IS THE ONLY
GUIDANCE TO SUGGEST THIS. THUS...HAVE TAPERED POPS TO END ACROSS
THE AREA THIS MORNING. EXPECT CLOUDS TO PERSIST AND TEMPERATURES TO
BE LIMITED IN UPWARD EXPANSE...HIGHS IN THE 20S AND LOW 30S
EXPECTED.
BILLINGS WRIGHT
TONIGHT:
WOULD NORMALLY EXPECT A VERY COLD NIGHT WITH GOOD RADIATIONAL
COOLING...BUT LINGERING CLOUDS ACROSS THE SOUTH WILL MAKE MINIMUMS
A BIT TRICKY. WILL SHADE LOWER IN THE NORTH WHERE FRESH SNOW AND
CLEARING IS MOST LIKELY. IF IT CLEAR AND SMOOTH EARLY...MAY NOT BE
COOL ENOUGH.
SUN-MON:
FAST MOVING SYSTEM ACROSS OK HAS TRENDED SOUTH FROM 24HRS
AGO...WITH PRECIPITATION CHANCES ALONG OK BORDER CONTINUE TO DECR.
HOWEVER STILL EXPECT MODEST INCREASE IN CLOUDS FROM SHORTWAVE
DURING THE DAY. TEMPERATURES SUN NIGHT WILL BE TRICKY WITH WEAK
RETURN FLOW DEVELOPING ACROSS WESTERN HALF...SO EARLY LOW IS
POSSIBLE. RETURN FLOW DEVELOPS IN EARNEST DURING THE DAY BUT
INFLUX OF CLOUDS SHOULD TEMPER WARMUP. -HOWERTON
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 328 AM CST SAT FEB 1 2014
MODELS OVERALL STILL IN FAIRLY GOOD AGREEMENT WITH PATTERN CHANGE
AND RESULTANT ACTIVE WEATHER REGIME. PRECIPITATION WILL LIKELY
START WITH FIRST SYSTEM ON MON NIGHT AND CONTINUE THROUGHOUT TUE.
ACCUMULATING/ADVISORY CRITERIA SNOW LOOKS PROBABLE AT THIS
POINT...ESPECIALLY WITH PROLONGED PERIOD OF SNOW. PRECIPITATION
SHOULD WIND DOWN DURING THE EVENING AS 1040+MILLIBAR SURFACE HIGH
SETTLES INTO THE AREA. BOTH GFS/ECMWF SUGGEST THAT CLOUDS MAY
LINGER...OTHERWISE WOULD BE ADAMANT ABOUT DROPPING TEMPERATURES
EVEN MORE FROM THU MORNING-FRI MORNING. SOME TIME ON FRI...MODELS
ARE NOT IN AGREEMENT ON THIS...RETURN SURFACE FLOW DEVELOPS ALONG
WITH MASSIVE/IMPRESSIVE 850MB RETURN FLOW. TEMPERATURES DO APPEAR TO
BE COLD ENOUGH WITH THIS EVENT TO KEEP PRECIPITATION TYPE AS ALL
SNOW. -HOWERTON
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1137 AM CST SAT FEB 1 2014
LOW CLOUDS WILL GRADUALLY MOVE EASTWARD FOR TODAY AND CEILING
HEIGHTS WILL RISE SLOWLY FROM MVFR TO VFR CATEGORY BY DARK OVER
SOUTHERN KANSAS. SOME LIGHT SNOW IS POSSIBLE ACROSS SOUTHERN
KANSAS FOR THIS AFTERNOON/EVENING BUT SHOULD HAVE LITTLE AFFECT
DUE TO THE LIGHT NATURE. MEANWHILE...NORTHERLY WINDS LOOK TO GET A
LITTLE UPTICK FOR LATE THIS AFTERNOON AND EVENING...AS SURFACE
HIGH PRESSURE BUILDS SOUTHWARD INTO THE REGION. VFR CONDITIONS
LOOK TO PREVAIL ON SUNDAY.
JAKUB
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 29 12 30 11 / 10 10 10 0
HUTCHINSON 30 10 30 11 / 10 10 10 0
NEWTON 29 9 29 10 / 10 10 10 0
ELDORADO 29 11 29 9 / 10 10 10 0
WINFIELD-KWLD 30 14 30 12 / 30 10 10 10
RUSSELL 30 3 29 10 / 0 10 10 0
GREAT BEND 30 5 30 11 / 0 10 10 0
SALINA 29 4 30 8 / 10 10 10 0
MCPHERSON 29 8 30 10 / 10 10 10 0
COFFEYVILLE 31 17 30 15 / 30 10 10 10
CHANUTE 29 14 28 8 / 30 10 10 10
IOLA 29 13 27 7 / 20 10 10 10
PARSONS-KPPF 30 14 29 11 / 30 10 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1109 AM CST SAT FEB 1 2014
.UPDATE...
ISSUED AT 1101 AM CST SAT FEB 1 2014
CURRENT SATELLITE IMAGERY SHOWS SOME CLOUD ENHANCEMENTS FROM UPPER
JET DYNAMICS SPREADING ACROSS SOUTHERN KANSAS...AND LOOKING AT
TRENDS OF LOCAL RADAR VAD WIND PROFILERS ECHOS IN THE MID-LEVELS
WERE GRADUALLY WORKING DOWNWARD. THIS COULD GIVE WAY TO A SEEDER-
FEEDER PROCESS IN THE ATMOSPHERE AND GENERATE SOME LIGHT SNOW OR
FLURRIES ACROSS SOUTHERN KANSAS FOR THE AFTERNOON HOURS...AND
LINGER INTO THE EVENING HOURS. A TRACE TO A LIGHT DUSTING OF SNOW
IS POSSIBLE WITH THIS ACTIVITY.
JAKUB
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 328 AM CST SAT FEB 1 2014
TODAY:
THE MIXED PRECIPITATION IS EXPECTED TO COME TO AN END THIS MORNING.
THE LATEST GUIDANCE HAS THE BULK OF THE PRECIPITATION EXITING INTO
MISSOURI NOT LONG AFTER THIS ISSUANCE...AND ON THE WHOLE THAT LOOKS
TO BE CLOSE TO WHAT IS OCCURRING. A DOWNWARD TREND IN PRECIPITATION
IS BEING OBSERVED AS OF THIS ISSUANCE...AND EXPECT THAT TO PERSIST.
ANY RESIDUAL PRECIPITATION WILL CONTINUE TO BE A MIX. THE LAST FEW
RUNS OF THE HRRR DEVELOP A BAND OF PRECIPITATION DURING THE
AFTERNOON HOURS OVER SOUTH CENTRAL KANSAS...BUT THIS IS THE ONLY
GUIDANCE TO SUGGEST THIS. THUS...HAVE TAPERED POPS TO END ACROSS
THE AREA THIS MORNING. EXPECT CLOUDS TO PERSIST AND TEMPERATURES TO
BE LIMITED IN UPWARD EXPANSE...HIGHS IN THE 20S AND LOW 30S
EXPECTED.
BILLINGS WRIGHT
TONIGHT:
WOULD NORMALLY EXPECT A VERY COLD NIGHT WITH GOOD RADIATIONAL
COOLING...BUT LINGERING CLOUDS ACROSS THE SOUTH WILL MAKE MINIMUMS
A BIT TRICKY. WILL SHADE LOWER IN THE NORTH WHERE FRESH SNOW AND
CLEARING IS MOST LIKELY. IF IT CLEAR AND SMOOTH EARLY...MAY NOT BE
COOL ENOUGH.
SUN-MON:
FAST MOVING SYSTEM ACROSS OK HAS TRENDED SOUTH FROM 24HRS
AGO...WITH PRECIPITATION CHANCES ALONG OK BORDER CONTINUE TO DECR.
HOWEVER STILL EXPECT MODEST INCREASE IN CLOUDS FROM SHORTWAVE
DURING THE DAY. TEMPERATURES SUN NIGHT WILL BE TRICKY WITH WEAK
RETURN FLOW DEVELOPING ACROSS WESTERN HALF...SO EARLY LOW IS
POSSIBLE. RETURN FLOW DEVELOPS IN EARNEST DURING THE DAY BUT
INFLUX OF CLOUDS SHOULD TEMPER WARMUP. -HOWERTON
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 328 AM CST SAT FEB 1 2014
MODELS OVERALL STILL IN FAIRLY GOOD AGREEMENT WITH PATTERN CHANGE
AND RESULTANT ACTIVE WEATHER REGIME. PRECIPITATION WILL LIKELY
START WITH FIRST SYSTEM ON MON NIGHT AND CONTINUE THROUGHOUT TUE.
ACCUMULATING/ADVISORY CRITERIA SNOW LOOKS PROBABLE AT THIS
POINT...ESPECIALLY WITH PROLONGED PERIOD OF SNOW. PRECIPITATION
SHOULD WIND DOWN DURING THE EVENING AS 1040+MILLIBAR SURFACE HIGH
SETTLES INTO THE AREA. BOTH GFS/ECMWF SUGGEST THAT CLOUDS MAY
LINGER...OTHERWISE WOULD BE ADAMANT ABOUT DROPPING TEMPERATURES
EVEN MORE FROM THU MORNING-FRI MORNING. SOME TIME ON FRI...MODELS
ARE NOT IN AGREEMENT ON THIS...RETURN SURFACE FLOW DEVELOPS ALONG
WITH MASSIVE/IMPRESSIVE 850MB RETURN FLOW. TEMPERATURES DO APPEAR TO
BE COLD ENOUGH WITH THIS EVENT TO KEEP PRECIPITATION TYPE AS ALL
SNOW. -HOWERTON
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 545 AM CST SAT FEB 1 2014
THE BIGGEST AVIATION CONCERN OF FREEZING PRECIPITATION HAS MAINLY
ENDED ACROSS THE AREA. SOME RESIDUAL FREEZING DRIZZLE COULD STILL
IMPACT KCNU THROUGH THE NEXT FEW HOURS. BEYOND THE FREEZING
PRECIP...LOW CEILINGS WILL BE THE BIGGEST CHALLENGE. THE SHORT
TERM GUIDANCE IS PERSISTENT WITH LOW CEILINGS ACROSS THE AREA.
HAVE KEPT MVFR CEILINGS ACROSS MUCH OF THE AREA FOR MUCH OF THE
FORECAST. BY TONIGHT...DRYER AIR WILL BE PUSHING IN AT THE LOW
LEVELS...AND CEILINGS WILL LIFT TO VFR. TAFS ARE PESSIMISTIC WITH
CEILING HEIGHT...SO COULD SEE SOME AMENDMENTS IF CONDITIONS ARE
BETTER THAN ANTICIPATED.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 29 12 30 11 / 10 10 10 0
HUTCHINSON 30 10 30 11 / 10 10 10 0
NEWTON 29 9 29 10 / 10 10 10 0
ELDORADO 29 11 29 9 / 10 10 10 0
WINFIELD-KWLD 30 14 30 12 / 30 10 10 10
RUSSELL 30 3 29 10 / 0 10 10 0
GREAT BEND 30 5 30 11 / 0 10 10 0
SALINA 29 4 30 8 / 10 10 10 0
MCPHERSON 29 8 30 10 / 10 10 10 0
COFFEYVILLE 31 17 30 15 / 30 10 10 10
CHANUTE 29 14 28 8 / 30 10 10 10
IOLA 29 13 27 7 / 20 10 10 10
PARSONS-KPPF 30 14 29 11 / 30 10 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR KSZ098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1105 AM CST Sat Feb 1 2014
...Updated synopsis and aviation discussion...
.SYNOPSIS...
ISSUED AT 1103 AM CST SAT FEB 1 2014
At 12z Saturday an upper level trough was located over northern
British Columbia and a closed upper low was located off the coast
of the Pacific Northwest. East of this closed upper low...50 to 70
meter 12hr 500mb height rises were observed along the west coast
of Northern California and Oregon. Further east a 500mb trough
extended from the Northern Plains to southwest Utah/northwest
Arizona. A 700mb baroclinic zone/area of deformation was located
ahead of this upper level trough and stretched from northeast New
Mexico to southern Iowa. A 850mb ridge axis was located across
western Kansas. 850mb temperatures at 12z Saturday ranged from -6c
at Dodge City to -12c at Rapid City, SD and the winds were
northerly at 20 to 30kts. At the surface a stationary front at 12z
was located from central Texas to southeast Missouri.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 200 AM CST SAT FEB 1 2014
Short range models indicate the upper level trough in the
Intermountain West digging further southeast into the Desert
Southwest today. Meanwhile, near the surface, a large area of
arctic high pressure will sink south-southeastward across the
Dakotas today, then further down into Kansas tonight bringing
colder and much drier air into the region. This will result in
fairly dry conditions across central and much of western Kansas
through Saturday night. However, there is an outside chance
extreme southwest Kansas may see a few flurries this evening
as an easterly upslope flow sets up across southeastern Colorado
and northeastern New Mexico. This will occur where a zone of
increased low level convergence will develop between the arctic
high approaching from the north and a surface low set up from
west Texas into southern New Mexico.
As for temperatures, the arctic high pressure moving southward
across the Dakotas into the Central Plains will help reinforce the
cold air mass already in place across the Western High Plains today.
As a result, similar high temperatures from yesterday are likely
again today with highs only up into the 20s(F) to possibly the lower
to mid 30s(F). The arctic high will center itself across much of
Kansas tonight lowering H85 temperatures even further as clouds
begin to scatter out somewhat from the northeast. Expect lows down
into the single digits(F) north near the I-70 corridor to possibly
the Teens(F) closer to the Oklahoma border.
.LONG TERM...(Sunday through Friday)
ISSUED AT 344 AM CST SAT FEB 1 2014
The Monday Night-Tuesday storm continues to be the main focus of the
forecast. The global models are coming into a bit better focus
tracking a mid-level potential vorticity (PV) anomaly from southern
California early Monday to far southwest New Mexico by late Monday
Night...and lifting northeast through West Texas and into western
Oklahoma by midday Tuesday. This is a favorable track for southwest
Kansas moderate-heavy precipitation. The complicating factor will
be moisture return...as moisture will be poor across Texas. By early
Tuesday, Gulf of Mexico moisture will finally be taken in by the
mid-latitude cyclone and that is when moderate to heavy
precipitation rates will increase. From a timing standpoint, the
southwest Kansas region will be on the southwest periphery of the
storm by the time adequate moisture becomes involved. Despite the
moisture deficiency for at least half of the event, we are still
looking at a solid 3 to 6 inch event across much of the forecast
area from late Monday Night into Tuesday Afternoon. Strong cold air
advection in the low levels will occur by midday Tuesday, and the
increased pressure rises and gradient will result in an increase in
north surface winds. Wind speeds of 18 to 22 knots sustained will
likely occur by afternoon, especially west of highway 183, and
blowing/drifting snow will likely become an issue. We added some
areas blowing snow in the grids for the afternoon portion of the
Tuesday period.
In other areas of the forecast, Sunday Night and Monday temperatures
were increased given the increase in southerly winds and low level
warm advection ahead of the approaching storm. In fact, Monday could
be quite mild especially across the far southwest region with some
highs in the mid 40s possible in the Elkhart and Liberal areas.
Following the storm, the ECMWF model is suggesting some bitterly
cold temperatures Wednesday and Thursday with 850mb temperatures in
the -17 to -21F range. The fresh arctic airmass and expected snow
cover will lead to limited modification of the airmass. The latest
AllBlend guidance had highs in the mid teens for both Wednesday and
Thursday...and this may be too warm! We went ahead and lowered
these a couple degrees, especially considering that the ECMWF model
is suggesting highs both days in the single digits along and north
of the Arkansas River. We should see at least one night with lows
below zero. With snow cover, this could be setting up for the
coldest days/nights of the winter thus far.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1103 AM CST SAT FEB 1 2014
12z BUFR soundings and 14z HRRR indicating MVFR ceilings can be
expected this afternoon as 900mb to 850mb moisture improves across
western Kansas. These MVFR ceiling will give way to VFR conditions
after 03z as an area of high pressure at the surface builds into
the area from the north and the area of low level moisture moves
south/southwest into southeast Colorado and northern Oklahoma.
North to northeast winds will be at 10 to 15kts today and then
subside to 10kts or less after 00z Sunday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 29 10 29 14 / 10 10 0 10
GCK 30 9 29 14 / 10 10 0 10
EHA 31 12 29 17 / 10 10 0 10
LBL 31 12 31 16 / 10 10 10 10
HYS 28 5 27 12 / 0 10 0 10
P28 31 12 30 15 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...JJohnson
LONG TERM...Umscheid
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS WICHITA KS
545 AM CST SAT FEB 1 2014
.UPDATE...
ISSUED AT 545 AM CST SAT FEB 1 2014
PRECIPITATION ACROSS THE AREA CONTINUES ON A DOWN TREND...OR HAS
COMPLETELY CEASED. CANCELLING CENTRAL KANSAS COUNTIES FROM THE
WINTER WEATHER ADVISORY AS THE HAZARDOUS WEATHER HAS EXITED THE
AREA. WILL CONTINUE TO WATCH THE REMAINDER OF THE AREA TO SEE IF
IT CAN BE CANCELLED BEFORE ITS 9AM EXPIRATION TIME.
BILLINGS WRIGHT
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 328 AM CST SAT FEB 1 2014
TODAY:
THE MIXED PRECIPITATION IS EXPECTED TO COME TO AN END THIS MORNING.
THE LATEST GUIDANCE HAS THE BULK OF THE PRECIPITATION EXITING INTO
MISSOURI NOT LONG AFTER THIS ISSUANCE...AND ON THE WHOLE THAT LOOKS
TO BE CLOSE TO WHAT IS OCCURRING. A DOWNWARD TREND IN PRECIPITATION
IS BEING OBSERVED AS OF THIS ISSUANCE...AND EXPECT THAT TO PERSIST.
ANY RESIDUAL PRECIPITATION WILL CONTINUE TO BE A MIX. THE LAST FEW
RUNS OF THE HRRR DEVELOP A BAND OF PRECIPITATION DURING THE
AFTERNOON HOURS OVER SOUTH CENTRAL KANSAS...BUT THIS IS THE ONLY
GUIDANCE TO SUGGEST THIS. THUS...HAVE TAPERED POPS TO END ACROSS
THE AREA THIS MORNING. EXPECT CLOUDS TO PERSIST AND TEMPERATURES TO
BE LIMITED IN UPWARD EXPANSE...HIGHS IN THE 20S AND LOW 30S
EXPECTED.
BILLINGS WRIGHT
TONIGHT:
WOULD NORMALLY EXPECT A VERY COLD NIGHT WITH GOOD RADIATIONAL
COOLING...BUT LINGERING CLOUDS ACROSS THE SOUTH WILL MAKE MINIMUMS
A BIT TRICKY. WILL SHADE LOWER IN THE NORTH WHERE FRESH SNOW AND
CLEARING IS MOST LIKELY. IF IT CLEAR AND SMOOTH EARLY...MAY NOT BE
COOL ENOUGH.
SUN-MON:
FAST MOVING SYSTEM ACROSS OK HAS TRENDED SOUTH FROM 24HRS
AGO...WITH PRECIPITATION CHANCES ALONG OK BORDER CONTINUE TO DECR.
HOWEVER STILL EXPECT MODEST INCREASE IN CLOUDS FROM SHORTWAVE
DURING THE DAY. TEMPERATURES SUN NIGHT WILL BE TRICKY WITH WEAK
RETURN FLOW DEVELOPING ACROSS WESTERN HALF...SO EARLY LOW IS
POSSIBLE. RETURN FLOW DEVELOPS IN EARNEST DURING THE DAY BUT
INFLUX OF CLOUDS SHOULD TEMPER WARMUP. -HOWERTON
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 328 AM CST SAT FEB 1 2014
MODELS OVERALL STILL IN FAIRLY GOOD AGREEMENT WITH PATTERN CHANGE
AND RESULTANT ACTIVE WEATHER REGIME. PRECIPITATION WILL LIKELY
START WITH FIRST SYSTEM ON MON NIGHT AND CONTINUE THROUGHOUT TUE.
ACCUMULATING/ADVISORY CRITERIA SNOW LOOKS PROBABLE AT THIS
POINT...ESPECIALLY WITH PROLONGED PERIOD OF SNOW. PRECIPITATION
SHOULD WIND DOWN DURING THE EVENING AS 1040+MILLIBAR SURFACE HIGH
SETTLES INTO THE AREA. BOTH GFS/ECMWF SUGGEST THAT CLOUDS MAY
LINGER...OTHERWISE WOULD BE ADAMANT ABOUT DROPPING TEMPERATURES
EVEN MORE FROM THU MORNING-FRI MORNING. SOME TIME ON FRI...MODELS
ARE NOT IN AGREEMENT ON THIS...RETURN SURFACE FLOW DEVELOPS ALONG
WITH MASSIVE/IMPRESSIVE 850MB RETURN FLOW. TEMPERATURES DO APPEAR TO
BE COLD ENOUGH WITH THIS EVENT TO KEEP PRECIPITATION TYPE AS ALL
SNOW. -HOWERTON
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 545 AM CST SAT FEB 1 2014
THE BIGGEST AVIATION CONCERN OF FREEZING PRECIPITATION HAS MAINLY
ENDED ACROSS THE AREA. SOME RESIDUAL FREEZING DRIZZLE COULD STILL
IMPACT KCNU THROUGH THE NEXT FEW HOURS. BEYOND THE FREEZING
PRECIP...LOW CEILINGS WILL BE THE BIGGEST CHALLENGE. THE SHORT
TERM GUIDANCE IS PERSISTENT WITH LOW CEILINGS ACROSS THE AREA.
HAVE KEPT MVFR CEILINGS ACROSS MUCH OF THE AREA FOR MUCH OF THE
FORECAST. BY TONIGHT...DRYER AIR WILL BE PUSHING IN AT THE LOW
LEVELS...AND CEILINGS WILL LIFT TO VFR. TAFS ARE PESSIMISTIC WITH
CEILING HEIGHT...SO COULD SEE SOME AMENDMENTS IF CONDITIONS ARE
BETTER THAN ANTICIPATED.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 32 12 30 11 / 20 10 10 0
HUTCHINSON 32 10 30 11 / 20 10 10 0
NEWTON 31 9 29 10 / 20 10 10 0
ELDORADO 31 11 29 9 / 20 10 10 0
WINFIELD-KWLD 32 14 30 12 / 20 10 10 10
RUSSELL 29 3 29 10 / 10 0 10 0
GREAT BEND 31 5 30 11 / 10 10 10 0
SALINA 30 4 30 8 / 20 0 10 0
MCPHERSON 31 8 30 10 / 20 0 10 0
COFFEYVILLE 33 17 30 15 / 20 10 10 10
CHANUTE 30 14 28 8 / 20 10 10 10
IOLA 30 13 27 7 / 20 10 10 10
PARSONS-KPPF 31 14 29 11 / 20 10 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR
KSZ051>053-067>072-082-083-091>096-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
333 AM CST SAT FEB 1 2014
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 328 AM CST SAT FEB 1 2014
TODAY:
THE MIXED PRECIPITATION IS EXPECTED TO COME TO AN END THIS MORNING.
THE LATEST GUIDANCE HAS THE BULK OF THE PRECIPITATION EXITING INTO
MISSOURI NOT LONG AFTER THIS ISSUANCE...AND ON THE WHOLE THAT LOOKS
TO BE CLOSE TO WHAT IS OCCURRING. A DOWNWARD TREND IN PRECIPITATION
IS BEING OBSERVED AS OF THIS ISSUANCE...AND EXPECT THAT TO PERSIST.
ANY RESIDUAL PRECIPITATION WILL CONTINUE TO BE A MIX. THE LAST FEW
RUNS OF THE HRRR DEVELOP A BAND OF PRECIPITATION DURING THE
AFTERNOON HOURS OVER SOUTH CENTRAL KANSAS...BUT THIS IS THE ONLY
GUIDANCE TO SUGGEST THIS. THUS...HAVE TAPERED POPS TO END ACROSS
THE AREA THIS MORNING. EXPECT CLOUDS TO PERSIST AND TEMPERATURES TO
BE LIMITED IN UPWARD EXPANSE...HIGHS IN THE 20S AND LOW 30S
EXPECTED.
BILLINGS WRIGHT
TONIGHT:
WOULD NORMALLY EXPECT A VERY COLD NIGHT WITH GOOD RADIATIONAL
COOLING...BUT LINGERING CLOUDS ACROSS THE SOUTH WILL MAKE MINIMUMS
A BIT TRICKY. WILL SHADE LOWER IN THE NORTH WHERE FRESH SNOW AND
CLEARING IS MOST LIKELY. IF IT CLEAR AND SMOOTH EARLY...MAY NOT BE
COOL ENOUGH.
SUN-MON:
FAST MOVING SYSTEM ACROSS OK HAS TRENDED SOUTH FROM 24HRS
AGO...WITH PRECIPITATION CHANCES ALONG OK BORDER CONTINUE TO DECR.
HOWEVER STILL EXPECT MODEST INCREASE IN CLOUDS FROM SHORTWAVE
DURING THE DAY. TEMPERATURES SUN NIGHT WILL BE TRICKY WITH WEAK
RETURN FLOW DEVELOPING ACROSS WESTERN HALF...SO EARLY LOW IS
POSSIBLE. RETURN FLOW DEVELOPS IN EARNEST DURING THE DAY BUT
INFLUX OF CLOUDS SHOULD TEMPER WARMUP. -HOWERTON
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 328 AM CST SAT FEB 1 2014
MODELS OVERALL STILL IN FAIRLY GOOD AGREEMENT WITH PATTERN CHANGE
AND RESULTANT ACTIVE WEATHER REGIME. PRECIPITATION WILL LIKELY
START WITH FIRST SYSTEM ON MON NIGHT AND CONTINUE THROUGHOUT TUE.
ACCUMULATING/ADVISORY CRITERIA SNOW LOOKS PROBABLE AT THIS
POINT...ESPECIALLY WITH PROLONGED PERIOD OF SNOW. PRECIPITATION
SHOULD WIND DOWN DURING THE EVENING AS 1040+MILLIBAR SURFACE HIGH
SETTLES INTO THE AREA. BOTH GFS/ECMWF SUGGEST THAT CLOUDS MAY
LINGER...OTHERWISE WOULD BE ADAMENT ABOUT DROPPING TEMPERATURES
EVEN MORE FROM THU MORNING-FRI MORNING. SOME TIME ON FRI...MODELS
ARE NOT IN AGREEMENT ON THIS...RETURN SURFACE FLOW DEVELOPS ALONG
WITH MASSIVE/IMPRESSIVE 850MB RETURN FLOW. TEMPERATURES DO APPEAR TO
BE COLD ENOUGH WITH THIS EVENT TO KEEP PRECIPITATION TYPE AS ALL
SNOW. -HOWERTON
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1017 PM CST FRI JAN 31 2014
ALL AREAS TO BE IFR THRU SAT MORNING (12Z-15Z) WITH A WIDESPREAD
WINTRY MIX FREQUENTLY REDUCING VSBYS TO 1-2SM. IN CNTRL KS VSBYS
WOULD BE THE MORE DOMINANT PLAYER IN KSLN & KRSL BEING PLACED IN
IFR STATUS. AS A NE-SW ORIENTED MID-LVL TROF CONTINUES TO PUSH E
TOWARD THE KS/MO BORDER SAT AFTERNOON...THE WEAK SFC LOW & COLD
FRONT WILL GET FORCED SE TO BRING WINTRY MIX TO A QUICK END OVER
MOST AREAS BY 12Z...BY WHICH TIME CIGS IN MOST AREAS WILL HAVE
CLEARED THE 1,000FT HURDLE WITH 1,200-1,500FT DECKS PREVALENT FROM
15Z ONWARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 32 12 30 11 / 20 10 10 0
HUTCHINSON 32 10 30 11 / 20 10 10 0
NEWTON 31 9 29 10 / 20 10 10 0
ELDORADO 31 11 29 9 / 20 10 10 0
WINFIELD-KWLD 32 14 30 12 / 20 10 10 10
RUSSELL 29 3 29 10 / 10 0 10 0
GREAT BEND 31 5 30 11 / 10 10 10 0
SALINA 30 4 30 8 / 20 0 10 0
MCPHERSON 31 8 30 10 / 20 0 10 0
COFFEYVILLE 33 17 30 15 / 20 10 10 10
CHANUTE 30 14 28 8 / 20 10 10 10
IOLA 30 13 27 7 / 20 10 10 10
PARSONS-KPPF 31 14 29 11 / 20 10 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ032-
033-047>053-067>072-082-083-091>096-098>100.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1055 PM EST SUN FEB 2 2014
.UPDATE...
ISSUED AT 1045 PM EST SUN FEB 2 2014
HAVE UPDATED THE FORECAST...INCLUDING SNOW AMOUNTS. THIS ALSO
INVOLVED ADDING IN SLEET AND POCKETS OF FREEZING RAIN FOR TIMES OF
LIGHTER PCPN THROUGH THE NEXT SEVERAL HOURS. THE CHALLENGE FOR THIS
FORECAST IS THAT THE NEXT SURGE OF PCPN WILL TELL THE TALE AND
DETERMINE THE SNOW AMOUNTS AS IT BRINGS IN COPIOUS MOISTURE AND A
COLDER COLUMN OF AIR. THE LATEST NAM12 STILL PRINTS OUT ENOUGH FOR A
HALF FOOT OF SNOW THROUGH THE WARNING AREA WITH A POTENTIAL CLOSE TO
DOUBLE DIGITS. AS SUCH...HAVE NOT HAD TO ADJUST THE SNOW TOTALS
MUCH...JUST A TOUCH MORE FOR NORTHERN PULASKI AND SLIGHTLY LOWER IN
THE SOUTHEAST PARTS OF THE WARNING BLOCK. THIS WILL BE A QUITE
INTERESTING NIGHT AS THAT SURGE MOVES THROUGH WITH COOLING CLOUD
TOPS NOW SHOWING UP ON SATELLITE AND A CONTINUED POTENTIAL FOR
THUNDER. STILL SEE SNOWFALL RATES APPROACHING 2 INCHES AS A DISTINCT
POSSIBILITY DURING A WINDOW BETWEEN 1 AND 5 AM ACROSS THE WARNED
AREA. THE UPDATED GRIDS...HEADLINES AND ZONES HAVE BEEN SENT WITH ALL
THIS IN MIND.
UPDATE ISSUED AT 730 PM EST SUN FEB 2 2014
23Z SFC ANALYSIS SHOWS A DEVELOPING AREA OF LOW PRESSURE RIDING
NORTHEAST INTO THE SOUTHERN APPALACHIANS. THIS HAS BENT THE WIND FLOW
AROUND TO THE NORTH AND NORTHEAST THROUGH THE CWA. ACCORDINGLY...
TEMPERATURES ARE FALLING INTO THE LOWER 30S IN THE NORTH AND INTO THE
MIDDLE 30S THROUGH THE BREADTH OF THE AREA WHILE A FEW 40S REMAIN
OVER THE FAR SOUTHEAST. THE LATEST OF SEVERAL WAVES OF PCPN IS
OVERSPREADING THE NORTHWEST PARTS OF EAST KENTUCKY WITH MOSTLY RAIN
BUT SOME REPORTS OF SLEET AND HIGHER RETURNS SEEN IN THE RADAR
IMAGERY. THE CURRENT FORECAST IS GENERALLY ON TRACK WITH THE
ADDITION OF MORE OF A SLOUGH ZONE FOR SLEET AND EVEN PATCHY FREEZING
RAIN. FOR THE MOST PART...SNOW WILL BE P-TYPE LATER THIS EVENING AND
EARLY OVERNIGHT FOR THE WARNING COUNTIES ONCE THE NEXT SURGE ARRIVES.
UNTIL THEN...THOUGH SLEET AND SNOW WILL MIX WITH RAIN DEPENDING ON
THE HEAVINESS OF EACH SHOWER.
THE NEXT SURGE WILL BRING HEFTIER QPF AND RESULT IN QUICKLY
ACCUMULATING SNOWS DUE TO THE ISOTHERMAL SOUNDINGS OVER THE NORTHWEST
HALF OF THE FORECAST AREA WHEN IT ARRIVES. RATES OF TWO INCHES AN
HOUR ARE POSSIBLE FROM THIS ALONG WITH ISOLATED POCKETS OF THUNDER.
TO THE SOUTHEAST...IT WILL BE MORE TRICKY WITH THE COLDER AIR
FILTERING IN BENEATH THE WARM NOSE MAKING PATCHY FREEZING RAIN AND
DRIZZLE A POSSIBILITY WHEN TEMPS APPROACH 32. HOWEVER...THIS WILL NOT
BE A HARD FREEZE SO ANY GLAZING IS EXPECTED TO BE CONFINED TO THE
ELEVATED SFC LIKE RAILINGS AND CAR HOODS/ROOFS RATHER THAN IMPACTING
THE ROADS. OF COURSE...THE USUAL CAVEATS OF BRIDGES AND OVERPASSES
APPLY. FOR THESE AREAS...A WINTER WEATHER ADVISORY IS IN EFFECT WITH
THE ICING POTENTIAL A COMPONENT TO THE HAZARD.
OF NOTE...NORTHERN PARTS OF PULASKI...LAUREL AND CLAY COUNTY MAY SEE
AMOUNTS APPROACHING WARNING CRITERIA PER THE LATEST HRRR AND 18Z
NAM12. WILL MONITOR THIS POTENTIAL FOR SIGNS THAT THE COLDER AIR
COLUMN MAKES IT TO THESE PARTS AHEAD OF FORECAST AND AFFECT OUR SNOW
TOTALS THERE ACCORDINGLY. FOR NOW WILL LEAVE ALL THE HEADLINES AS
THEY ARE AND HOLD PAT WITH THE ZONES...THOUGH DID FINE TUNE THE WX...
T...AND TD GRIDS THROUGH 06Z. THESE GRIDDED UPDATES HAVE BEEN SENT
TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 309 PM EST SUN FEB 2 2014
FRONTAL BOUNDARY CONTINUES TO SAG SOUTHWARD ACROSS EASTERN KENTUCKY
THIS AFTERNOON AND PRESENTLY EXTENDS FROM MARTIN COUNTY...BACK TO THE
SOUTHWEST TO MCCREARY COUNTY. THIS BOUNDARY SHOULD PUSH ON THROUGH
THE LAST OF EASTERN KENTUCKY OVER THE NEXT FEW HOURS WITH
TEMPERATURES BEGINNING THEIR RATHER QUICK DECENT. TEMPERATURES BEHIND
THE FRONT HAVE ALREADY FALLEN INTO THE LOW TO MID 30S ACROSS THE FAR
NORTH. THIS IS IN LINE WITH THE PREVIOUS FORECAST...SO OUR
TEMPERATURES SEEM TO BE RUNNING FAIRLY CLOSE TO EXPECTED VALUES.
MEANWHILE...PRECIPITATION IS ALREADY LOADING UP UPSTREAM...WITH
RADAR RETURNS RAMPING UP ACROSS SOUTH CENTRAL KENTUCKY. THIS
PRECIPITATION WILL OVERSPREAD EASTERN KENTUCKY OVER THE NEXT FEW
HOURS...WITH MAINLY RAIN EXPECTED AT THE ONSET. WITH TEMPERATURES
ALREADY INTO THE LOWER 30S IN THE NORTH...WE COULD SEE SNOW AT THE
ONSET. A STRONG FRONTOGENTICAL CIRCULATION IS EXPECTED TO DEVELOP
ACROSS EASTERN KENTUCKY TONIGHT...WITH IMPRESSIVE OMEGA EXPECTED
ACROSS THE NORTHERN HALF OF THE FORECAST AREA. A CROSS SECTION ACROSS
EASTERN KENTUCKY REVEALS A NEGATIVE AREA OF SATURATED EQUIVALENT
POTENTIAL TEMPERATURE...SUGGESTING SOME POSSIBLE ELEVATED THUNDER
THROUGH THE OVERNIGHT HOURS. ALL OF THIS POINTS TO SOME PRETTY
IMPRESSIVE SNOWFALL RATES AS THE TRANSITION FROM RAIN TO SNOW TAKES
PLACE. THUS...GIVEN THE EXPECT 0.75 TO 0.90 OF LIQUID MODELS ARE
PUTTING OUT ACROSS THE NORTH...A BAND OF 6 TO 9 INCHES OF SNOWFALL
CERTAINLY SEEMS POSSIBLE AND PERHAPS EVEN LIKELY. BASED ON UPSTREAM
TRENDS...IT APPEARS THE I-64 CORRIDOR SEEMS TO THE BE THE TARGET
GROUND FOR THE BEST SNOWFALL. PLAN TO INTRODUCE SOME THUNDER INTO THE
FORECAST GIVEN THE ELEVATED INSTABILITY. WILL ALSO INCREASE THE
WORDING TO HEAVY SNOW ACROSS THE NORTHERN AREAS. NO CHANGES PLANNED
TO CURRENT HEADLINES.
LOOKS LIKE WE SHOULD SEE A FAIRLY SHARP GRADIENT WITH SNOWFALL
TONIGHT AS THE THE COLD AIR BLEEDS IN FROM THE NORTHWEST...SLOWLY
CHANGING PRECIPITATION OVER. THIS CHANGEOVER MAY NOT OCCUR UNTIL VERY
LATE TONIGHT...IF AT ALL...WITH SOUTHEAST AREAS POSSIBLY STAYING RAIN
OR EVEN FREEZING RAIN. FREEZING RAIN SHOULD NOT BE A HUGE IMPACT
HOWEVER...AS TEMPERATURES SHOULD ONLY FALL TO JUST AROUND 32 BY 7 AM
MONDAY MORNING...AND WITH RECENT MILD WEATHER...MAY NOT BE A BIG
IMPACT. REGARDLESS...A FEW SLICK SPOTS WILL STILL BE POSSIBLE AND
PLAN TO RIDE WITH THE WINTER WEATHER ADVISORY. AREAS ALONG AND SOUTH
OF THE HAL ROGERS PARKWAY MAY ONLY SEE A DUSTING TO AN INCH OF
SNOWFALL.
PRECIPITATION WILL WIND DOWN MONDAY MORNING...BEFORE COMING TO AN END
ACROSS THE EAST BY MIDDAY. TEMPERATURES WILL LIKELY BE HELD DOWN
ACROSS THE NORTH WITH THE FRESH SNOW...WHILE AREAS IN THE SOUTH MAY
RECOVER BACK TO AROUND 40 BY THE AFTERNOON. BY MONDAY NIGHT...FRESH
SNOW COVER AND CLEARING SKIES WILL ALLOW A QUICK DROP OFF IN
TEMPERATURES ACROSS THE NORTH...WITH VALLEY LOCATIONS LIKELY FALLING
INTO THE LOW 20S FOR LOWS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 224 PM EST SUN FEB 2 2014
THE MODELS START OUT IN VERY GOOD AGREEMENT WITH A TROUGH ON THE
SOUTHERN STREAM EXTENDING SOUTH FROM COLORADO TO THE THE SONORA
DESSERT. THERE IS ANOTHER TROUGH EXTENDING FROM IDAHO TO UTAH ON THE
NORTHERN STREAM. A COLD FRONT EXTENDS FROM NORTHERN MICHIGAN TO
SOUTHWESTERN NEBRASKA ON THE NORTHERN STREAM AND ANOTHER FRONT LIES
ALONG THE GULF COAST. A LOW IS FORECAST TO FORM ON THE FRONT OVER
LOUISIANA ON TUESDAY MORNING. THE LOW WITH STRENGTHEN AND MOVE TO
THE NORTHEAST AS THE NORTHERN STREAM COLD FRONT ALSO DIP TO THE
SOUTH. THE UPPER LOWS LOOK LIKE THEY WILL BE PHASING AND THIS WILL
BRING A STRONG COLD FRONT ACROSS THE AREA ON TUESDAY. THE SURFACE
LOW THAT WAS ORIGINALLY OVER LOUISIANA...WILL PUMP SOME MOISTURE UP
AHEAD OF THE SYSTEM. THE MAIN LOW WILL EVENTUALLY PASS TO THE NORTH
OF THE AREA. THE COMBINATION OF THE PHASING UPPER TROUGHS AND THE
AVAILABLE MOISTURE WILL GIVE THE POTENTIAL FOR SOME SIGNIFICANT
RAINFALL WITH THIS SYSTEM THAT COULD RESULT IN SOME INITIAL
LOCALIZED FLOODING FOLLOW BY SOME HIGH RIVERS. AS THE SYSTEM MOVES
OUT OF THE AREA ON WEDNESDAY...THE RAIN WILL MIX WITH SNOW AND
THEN BECOME ALL SNOW AS A LAST GASP AS THE SYSTEM EXITS. VERY LITTLE
ACCUMULATION IS EXPECTED AS THE LAST OF THE SNOW MOVES INTO VIRGINIA
ON WEDNESDAY NIGHT. .
THE UPPER AIR BECOMES MORE ZONAL ON WEDNESDAY...HOWEVER BY FRIDAY
ANOTHER UPPER TROUGH WILL DROP INTO THE SOUTHWEST AND THE NEXT COLD
FRONT WILL ENTER INTO THE AREA ON FRIDAY AND REMAIN UNSETTLED
THROUGH THE END OF THE PERIOD. SOME LIGHT ACCUMULATIONS OF SNOW ARE
EXPECTED WITH THIS SYSTEM.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 700 PM EST SUN FEB 2 2014
IN GENERAL...IFR AND LIFR CEILINGS WILL CONTINUE ACROSS THE AREA AS
SEVERAL WAVES MOVE ALONG THE COLD FRONT TO THE SOUTH OF THE AREA. AS
THE WAVES MOVE THROUGH...THEY WILL ENERGIZE THE FRONT AND CAUSE
WIDESPREAD RAIN TO TURN TO SNOW. THE QUESTION REMAINS WHERE THE CUT
OFF IS BETWEEN THE RAIN AND THE SNOW AND IF THERE WILL BE ANY
FREEZING RAIN AT THE TAF STATIONS. WHILE SOME OF THE TAF MOS
SOLUTIONS HAD SOME FREEZING PRECIPITATION PREDICTED AT THE SITES...
FROM DOING TOP DOWN ANALYSIS ON THE NAM BUFFER SOUNDINGS...THE
THREAT OF SIGNIFICANT FREEZING PRECIPITATION CONTINUES TO LOOK
UNLIKELY. IT IS POSSIBLE...THAT SME AND LOZ MAY NOT HAVE MUCH SNOW
BUT BE MORE OF A RAIN AND SNOW MIX FOR MUCH OF THE NIGHT. IT WILL
CERTAINLY BE A FINE LINE BETWEEN THE HEAVY SNOW AND LIGHTER AMOUNTS
NEAR THOSE SITES. ALSO...THERE IS STILL SOME UNCERTAINTY ON THE
TRACKS OF THESE PCPN WAVES WHICH COULD CAUSE FURTHER ADJUSTMENTS TO
THE FORECAST. THE AREA ALONG AND NORTH OF I 64 IS THE MOST LIKELY TO
SEE THE HEAVY SNOW WITH A GOOD CHANCE DOWN THROUGH THE MOUNTAIN
PARKWAY AREA TO ABOUT 20-30 MILES NORTH OF THE HAL ROGERS PARKWAY.
ELSEWHERE...RAIN WILL RULE FOR MOST OF THE EVENT WITH JUST A TAIL
END OF SNOW EXPECTED. WINDS WILL BE GENERALLY FROM THE NORTH TO
NORTHEAST AT 5 TO 10 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 10 AM EST MONDAY FOR KYZ044-050>052.
WINTER STORM WARNING UNTIL 11 AM EST MONDAY FOR KYZ058>060-104-
106-108-111.
WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR KYZ079-080-110-
113-115>117-119-120.
WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR KYZ083>088-118.
WINTER STORM WARNING UNTIL NOON EST MONDAY FOR KYZ068-069-107-
109-112-114.
&&
$$
UPDATE...GREIF
SHORT TERM...KAS
LONG TERM...JJ
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
730 PM EST SUN FEB 2 2014
.UPDATE...
ISSUED AT 730 PM EST SUN FEB 2 2014
23Z SFC ANALYSIS SHOWS A DEVELOPING AREA OF LOW PRESSURE RIDING
NORTHEAST INTO THE SOUTHERN APPALACHIANS. THIS HAS BENT THE WIND FLOW
AROUND TO THE NORTH AND NORTHEAST THROUGH THE CWA. ACCORDINGLY...
TEMPERATURES ARE FALLING INTO THE LOWER 30S IN THE NORTH AND INTO THE
MIDDLE 30S THROUGH THE BREADTH OF THE AREA WHILE A FEW 40S REMAIN
OVER THE FAR SOUTHEAST. THE LATEST OF SEVERAL WAVES OF PCPN IS
OVERSPREADING THE NORTHWEST PARTS OF EAST KENTUCKY WITH MOSTLY RAIN
BUT SOME REPORTS OF SLEET AND HIGHER RETURNS SEEN IN THE RADAR
IMAGERY. THE CURRENT FORECAST IS GENERALLY ON TRACK WITH THE
ADDITION OF MORE OF A SLOUGH ZONE FOR SLEET AND EVEN PATCHY FREEZING
RAIN. FOR THE MOST PART...SNOW WILL BE P-TYPE LATER THIS EVENING AND
EARLY OVERNIGHT FOR THE WARNING COUNTIES ONCE THE NEXT SURGE ARRIVES.
UNTIL THEN...THOUGH SLEET AND SNOW WILL MIX WITH RAIN DEPENDING ON
THE HEAVINESS OF EACH SHOWER.
THE NEXT SURGE WILL BRING HEFTIER QPF AND RESULT IN QUICKLY
ACCUMULATING SNOWS DUE TO THE ISOTHERMAL SOUNDINGS OVER THE NORTHWEST
HALF OF THE FORECAST AREA WHEN IT ARRIVES. RATES OF TWO INCHES AN
HOUR ARE POSSIBLE FROM THIS ALONG WITH ISOLATED POCKETS OF THUNDER.
TO THE SOUTHEAST...IT WILL BE MORE TRICKY WITH THE COLDER AIR
FILTERING IN BENEATH THE WARM NOSE MAKING PATCHY FREEZING RAIN AND
DRIZZLE A POSSIBILITY WHEN TEMPS APPROACH 32. HOWEVER...THIS WILL NOT
BE A HARD FREEZE SO ANY GLAZING IS EXPECTED TO BE CONFINED TO THE
ELEVATED SFC LIKE RAILINGS AND CAR HOODS/ROOFS RATHER THAN IMPACTING
THE ROADS. OF COURSE...THE USUAL CAVEATS OF BRIDGES AND OVERPASSES
APPLY. FOR THESE AREAS...A WINTER WEATHER ADVISORY IS IN EFFECT WITH
THE ICING POTENTIAL A COMPONENT TO THE HAZARD.
OF NOTE...NORTHERN PARTS OF PULASKI...LAUREL AND CLAY COUNTY MAY SEE
AMOUNTS APPROACHING WARNING CRITERIA PER THE LATEST HRRR AND 18Z
NAM12. WILL MONITOR THIS POTENTIAL FOR SIGNS THAT THE COLDER AIR
COLUMN MAKES IT TO THESE PARTS AHEAD OF FORECAST AND AFFECT OUR SNOW
TOTALS THERE ACCORDINGLY. FOR NOW WILL LEAVE ALL THE HEADLINES AS
THEY ARE AND HOLD PAT WITH THE ZONES...THOUGH DID FINE TUNE THE WX...
T...AND TD GRIDS THROUGH 06Z. THESE GRIDDED UPDATES HAVE BEEN SENT
TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 309 PM EST SUN FEB 2 2014
FRONTAL BOUNDARY CONTINUES TO SAG SOUTHWARD ACROSS EASTERN KENTUCKY
THIS AFTERNOON AND PRESENTLY EXTENDS FROM MARTIN COUNTY...BACK TO THE
SOUTHWEST TO MCCREARY COUNTY. THIS BOUNDARY SHOULD PUSH ON THROUGH
THE LAST OF EASTERN KENTUCKY OVER THE NEXT FEW HOURS WITH
TEMPERATURES BEGINNING THEIR RATHER QUICK DECENT. TEMPERATURES BEHIND
THE FRONT HAVE ALREADY FALLEN INTO THE LOW TO MID 30S ACROSS THE FAR
NORTH. THIS IS IN LINE WITH THE PREVIOUS FORECAST...SO OUR
TEMPERATURES SEEM TO BE RUNNING FAIRLY CLOSE TO EXPECTED VALUES.
MEANWHILE...PRECIPITATION IS ALREADY LOADING UP UPSTREAM...WITH
RADAR RETURNS RAMPING UP ACROSS SOUTH CENTRAL KENTUCKY. THIS
PRECIPITATION WILL OVERSPREAD EASTERN KENTUCKY OVER THE NEXT FEW
HOURS...WITH MAINLY RAIN EXPECTED AT THE ONSET. WITH TEMPERATURES
ALREADY INTO THE LOWER 30S IN THE NORTH...WE COULD SEE SNOW AT THE
ONSET. A STRONG FRONTOGENTICAL CIRCULATION IS EXPECTED TO DEVELOP
ACROSS EASTERN KENTUCKY TONIGHT...WITH IMPRESSIVE OMEGA EXPECTED
ACROSS THE NORTHERN HALF OF THE FORECAST AREA. A CROSS SECTION ACROSS
EASTERN KENTUCKY REVEALS A NEGATIVE AREA OF SATURATED EQUIVALENT
POTENTIAL TEMPERATURE...SUGGESTING SOME POSSIBLE ELEVATED THUNDER
THROUGH THE OVERNIGHT HOURS. ALL OF THIS POINTS TO SOME PRETTY
IMPRESSIVE SNOWFALL RATES AS THE TRANSITION FROM RAIN TO SNOW TAKES
PLACE. THUS...GIVEN THE EXPECT 0.75 TO 0.90 OF LIQUID MODELS ARE
PUTTING OUT ACROSS THE NORTH...A BAND OF 6 TO 9 INCHES OF SNOWFALL
CERTAINLY SEEMS POSSIBLE AND PERHAPS EVEN LIKELY. BASED ON UPSTREAM
TRENDS...IT APPEARS THE I-64 CORRIDOR SEEMS TO THE BE THE TARGET
GROUND FOR THE BEST SNOWFALL. PLAN TO INTRODUCE SOME THUNDER INTO THE
FORECAST GIVEN THE ELEVATED INSTABILITY. WILL ALSO INCREASE THE
WORDING TO HEAVY SNOW ACROSS THE NORTHERN AREAS. NO CHANGES PLANNED
TO CURRENT HEADLINES.
LOOKS LIKE WE SHOULD SEE A FAIRLY SHARP GRADIENT WITH SNOWFALL
TONIGHT AS THE THE COLD AIR BLEEDS IN FROM THE NORTHWEST...SLOWLY
CHANGING PRECIPITATION OVER. THIS CHANGEOVER MAY NOT OCCUR UNTIL VERY
LATE TONIGHT...IF AT ALL...WITH SOUTHEAST AREAS POSSIBLY STAYING RAIN
OR EVEN FREEZING RAIN. FREEZING RAIN SHOULD NOT BE A HUGE IMPACT
HOWEVER...AS TEMPERATURES SHOULD ONLY FALL TO JUST AROUND 32 BY 7 AM
MONDAY MORNING...AND WITH RECENT MILD WEATHER...MAY NOT BE A BIG
IMPACT. REGARDLESS...A FEW SLICK SPOTS WILL STILL BE POSSIBLE AND
PLAN TO RIDE WITH THE WINTER WEATHER ADVISORY. AREAS ALONG AND SOUTH
OF THE HAL ROGERS PARKWAY MAY ONLY SEE A DUSTING TO AN INCH OF
SNOWFALL.
PRECIPITATION WILL WIND DOWN MONDAY MORNING...BEFORE COMING TO AN END
ACROSS THE EAST BY MIDDAY. TEMPERATURES WILL LIKELY BE HELD DOWN
ACROSS THE NORTH WITH THE FRESH SNOW...WHILE AREAS IN THE SOUTH MAY
RECOVER BACK TO AROUND 40 BY THE AFTERNOON. BY MONDAY NIGHT...FRESH
SNOW COVER AND CLEARING SKIES WILL ALLOW A QUICK DROP OFF IN
TEMPERATURES ACROSS THE NORTH...WITH VALLEY LOCATIONS LIKELY FALLING
INTO THE LOW 20S FOR LOWS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 224 PM EST SUN FEB 2 2014
THE MODELS START OUT IN VERY GOOD AGREEMENT WITH A TROUGH ON THE
SOUTHERN STREAM EXTENDING SOUTH FROM COLORADO TO THE THE SONORA
DESSERT. THERE IS ANOTHER TROUGH EXTENDING FROM IDAHO TO UTAH ON THE
NORTHERN STREAM. A COLD FRONT EXTENDS FROM NORTHERN MICHIGAN TO
SOUTHWESTERN NEBRASKA ON THE NORTHERN STREAM AND ANOTHER FRONT LIES
ALONG THE GULF COAST. A LOW IS FORECAST TO FORM ON THE FRONT OVER
LOUISIANA ON TUESDAY MORNING. THE LOW WITH STRENGTHEN AND MOVE TO
THE NORTHEAST AS THE NORTHERN STREAM COLD FRONT ALSO DIP TO THE
SOUTH. THE UPPER LOWS LOOK LIKE THEY WILL BE PHASING AND THIS WILL
BRING A STRONG COLD FRONT ACROSS THE AREA ON TUESDAY. THE SURFACE
LOW THAT WAS ORIGINALLY OVER LOUISIANA...WILL PUMP SOME MOISTURE UP
AHEAD OF THE SYSTEM. THE MAIN LOW WILL EVENTUALLY PASS TO THE NORTH
OF THE AREA. THE COMBINATION OF THE PHASING UPPER TROUGHS AND THE
AVAILABLE MOISTURE WILL GIVE THE POTENTIAL FOR SOME SIGNIFICANT
RAINFALL WITH THIS SYSTEM THAT COULD RESULT IN SOME INITIAL
LOCALIZED FLOODING FOLLOW BY SOME HIGH RIVERS. AS THE SYSTEM MOVES
OUT OF THE AREA ON WEDNESDAY...THE RAIN WILL MIX WITH SNOW AND
THEN BECOME ALL SNOW AS A LAST GASP AS THE SYSTEM EXITS. VERY LITTLE
ACCUMULATION IS EXPECTED AS THE LAST OF THE SNOW MOVES INTO VIRGINIA
ON WEDNESDAY NIGHT. .
THE UPPER AIR BECOMES MORE ZONAL ON WEDNESDAY...HOWEVER BY FRIDAY
ANOTHER UPPER TROUGH WILL DROP INTO THE SOUTHWEST AND THE NEXT COLD
FRONT WILL ENTER INTO THE AREA ON FRIDAY AND REMAIN UNSETTLED
THROUGH THE END OF THE PERIOD. SOME LIGHT ACCUMULATIONS OF SNOW ARE
EXPECTED WITH THIS SYSTEM.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 700 PM EST SUN FEB 2 2014
IN GENERAL...IFR AND LIFR CEILINGS WILL CONTINUE ACROSS THE AREA AS
SEVERAL WAVES MOVE ALONG THE COLD FRONT TO THE SOUTH OF THE AREA. AS
THE WAVES MOVE THROUGH...THEY WILL ENERGIZE THE FRONT AND CAUSE
WIDESPREAD RAIN TO TURN TO SNOW. THE QUESTION REMAINS WHERE THE CUT
OFF IS BETWEEN THE RAIN AND THE SNOW AND IF THERE WILL BE ANY
FREEZING RAIN AT THE TAF STATIONS. WHILE SOME OF THE TAF MOS
SOLUTIONS HAD SOME FREEZING PRECIPITATION PREDICTED AT THE SITES...
FROM DOING TOP DOWN ANALYSIS ON THE NAM BUFFER SOUNDINGS...THE
THREAT OF SIGNIFICANT FREEZING PRECIPITATION CONTINUES TO LOOK
UNLIKELY. IT IS POSSIBLE...THAT SME AND LOZ MAY NOT HAVE MUCH SNOW
BUT BE MORE OF A RAIN AND SNOW MIX FOR MUCH OF THE NIGHT. IT WILL
CERTAINLY BE A FINE LINE BETWEEN THE HEAVY SNOW AND LIGHTER AMOUNTS
NEAR THOSE SITES. ALSO...THERE IS STILL SOME UNCERTAINTY ON THE
TRACKS OF THESE PCPN WAVES WHICH COULD CAUSE FURTHER ADJUSTMENTS TO
THE FORECAST. THE AREA ALONG AND NORTH OF I 64 IS THE MOST LIKELY TO
SEE THE HEAVY SNOW WITH A GOOD CHANCE DOWN THROUGH THE MOUNTAIN
PARKWAY AREA TO ABOUT 20-30 MILES NORTH OF THE HAL ROGERS PARKWAY.
ELSEWHERE...RAIN WILL RULE FOR MOST OF THE EVENT WITH JUST A TAIL
END OF SNOW EXPECTED. WINDS WILL BE GENERALLY FROM THE NORTH TO
NORTHEAST AT 5 TO 10 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 10 AM EST MONDAY FOR KYZ044-050>052.
WINTER STORM WARNING UNTIL 11 AM EST MONDAY FOR KYZ058>060-104-
106-108-111.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 1 PM EST
MONDAY FOR KYZ079-080-110-113-115>117-119-120.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST MONDAY
FOR KYZ083>088-118.
WINTER STORM WARNING UNTIL NOON EST MONDAY FOR KYZ068-069-107-
109-112-114.
&&
$$
UPDATE...GREIF
SHORT TERM...KAS
LONG TERM...JJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
401 PM EST SAT FEB 1 2014
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY CREST OVER THE AREA...THEN MOVE EAST
THIS AFTERNOON. LOW PRESSURE WILL APPROACH FROM THE GREAT LAKES
TONIGHT AND CROSS THE REGION SUNDAY MORNING. HIGH PRESSURE WILL
BUILD EAST LATER SUNDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
NO SIG CHGS FROM RECENT PREV FCST UPDATES. HRRR FCST REF SHOWS
STEADY SN OVRSPRDNG WRN PTNS OF THE FA ERLY THIS EVE AND NE AND E
CNTRL PTNS BY LATE EVE. INITIALLY HRLY TEMPS WILL FALL THIS EVE
WITH EVAPORATIONAL COOLING WITH THE LEADING EDGE OF THE STEADY SN
CANOPY...THEN SLOWLY RISE OVRNGT WITH INCREASING LLVL WARM ADVCN
WITH SRLY GRAD WINDS. PRECIP WILL LIKELY MIX WITH OR EVEN CHG TO
RN ACROSS DOWNEAST AREAS BY DAYBREAK SUN.
STEADY PRECIP WILL WIND DOWN TO RN AND SN SHWRS FROM W TO E ACROSS
THE FA AFT MID SUN MORN...WITH ANY ADDITIONAL SN ACCUMULATION ACROSS
MSLY FAR NRN AREAS 1 TO 2 INCHES PRIOR TO LATE SUN MORN...AND
LITTLE OR NONE FURTHER S. HI TEMPS SUN AFTN WILL AGAIN BE SIG ABV
NORMAL.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AN ARCTIC FRONT AND ASSOCIATED DISTURBANCE ALOFT WILL BRING SOME SCATTERED
FLURRIES AND SNOW SHOWERS TO NORTHERN AREAS SUNDAY EVENING WITH
SKIES CLEARING OVERNIGHT. HIGH PRESSURE BUILDS IN FOR MONDAY AND
DOMINATES THROUGH TUESDAY WITH SEASONAL TEMPERATURES AND MAINLY
CLEAR TO PARTLY CLOUDY SKIES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
FOR THE LONG TERM, ATTENTION TURNS TO A STORM SYSTEM WHICH WILL
TRACK FROM THE SOUTHEASTERN STATES NORTH AND EAST TO NEAR
PENNSYLVANIA BY WEDNESDAY MORNING. COASTAL REDEVELOPMENT IS THEN
EXPECTED EARLY WEDNESDAY WITH THE SECONDARY LOW TRACKING FROM NEAR
SOUTHERN NEW ENGLAND TOWARD NOVA SCOTIA. THIS GENERAL TRACK WILL
KEEP THE AREA ON THE COLD, SNOWY SIDE OF THE SYSTEM HOWEVER
AMOUNTS WILL DEPEND ON THE EXACT TRACK AND INTENSITY OF THE SYSTEM
WHICH IS STILL UNCERTAIN AT THIS POINT. MAINTAINED CATEGORICAL
POPS DOWNEAST FOR WEDNESDAY IN ACCORDANCE WITH WHAT MOST OF THE
GUIDANCE IS STILL SHOWING AND TAPERED POPS TO NEAR 50% ACROSS THE
CROWN OF MAINE WHICH LOOKS TO BE NEAR THE NORTHERN EDGE OF THE
SYSTEM`S SNOW SHIELD. THE LOW WILL BE PROGRESSIVE WITH FAIR AND
SEASONALLY COLD CONDITIONS FOLLOWING FOR THE END OF THE WORK WEEK.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
NEAR TERM: VFR WILL QUICKLY TRANSITION TO IFR LATER THIS EVE AS
STEADY SN OVRSPRDS ALL TAF SITES...WITH PERHAPS KBHB HOLDING ON TO
MVFR OVRNGT DUE TO LESS PRECIP AND PRECIP TYPE MSLY RN. FURTHER N...
IFR CONDITIONS WILL IMPROVE TO MVFR BY MIDDAY SUN WITH KBGR
IMPROVING TO VFR LATER SUN AFTN.
SHORT TERM: MVFR/IFR WILL STILL BE POSSIBLE IN THE NORTH SUNDAY
EVENING WITH ALL AREAS BECOMING VFR BY MONDAY AND CONTINUING THIS
WAY THROUGH TUESDAY. A COASTAL LOW WILL LIKELY BRING SOME SNOW BY
WEDNESDAY, ESPECIALLY SOUTH, WITH A RETURN TO MVFR/IFR CONDITIONS.
&&
.MARINE...
NEAR TERM: WILL CONT WITH THE SCA FOR LATER THIS EVE THRU MOST OF
SUN AS PREVIOUSLY PLANNED. USED A BLEND OF MODEL OPNL AND MOS
WINDS FOR FCST WINDS AND A BLEND OF WW3/SWAN NAM/SWAN GFS FOR WV
HTS.
SHORT TERM: WINDS WILL PICK UP FOR A TIME LATER SUNDAY EVENING
INTO THE OVERNIGHT WITH THE PASSAGE OF AN ARCTIC FRONT WITH A FEW
GUSTS UP TO 25 KNOTS LIKELY DURING THIS TIME. THESE WINDS WILL
EASE THROUGH MONDAY AS HIGH PRESSURE BUILDS IN WITH RELATIVELY
TRANQUIL CONDITIONS EXPECTED FOR MONDAY NIGHT AND TUESDAY. A
COASTAL LOW TRACKING SOUTH OF THE WATERS WILL BRING INCREASING
WINDS AND WAVES FOR WEDNESDAY WITH THE POTENTIAL FOR AT LEAST SCA
CONDITIONS DEPENDING ON THE LOW`S TRACK. &&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 11 AM EST
SUNDAY FOR MEZ001>006-010.
MARINE...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 7 PM EST SUNDAY
FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...FITZSIMMONS
LONG TERM...FITZSIMMONS
AVIATION...VJN/FITZSIMMONS
MARINE...VJN/FITZSIMMONS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
349 PM EST SAT FEB 1 2014
.SYNOPSIS...
A COLD FRONT TONIGHT WILL RESULT IN RAIN CHANGING OVER TO LIGHT
SNOW SUNDAY MORNING WITH NO SIGNIFICANT ACCUMULATIONS SUNDAY
MORNING. ANOTHER SYSTEM SUNDAY NIGHT COULD BRING SNOW TO THE RIDGES.
&&
.NEAR TERM /THROUGH SUNDAY/...
CURRENT SATELLITE IMAGE HAS OUR AREA BLANKETED IN CLOUD COVER AS
A WARM FRONT PUSHES SLOWLY TO THE NORTH. RADAR STILL IS MORE BARK
THAN BITE...AS MUCH OF THE ECHOES VISIBLE ARE VIRGA AS DRY AIR
REMAINS LOCKED IN FROM SFC TO ABOUT 900MB...EVIDENT FROM THE 12Z
SOUNDING AND THE NEARLY 15 DEGREE DEW POINT SPREAD ON CURRENT OBS.
ALTHOUGH THE CLOUD COVER REMAINS...AM EXPECTING THE LOW LEVEL FLOW
TO STIFFEN FROM THE SOUTH AND CLEAR AT LEAST A PORTION OF OUR
SOUTH TO PARTLY CLOUDY. THIS SOUTHERLY FLOW...COMBINED WITH SOME
SUN SHOULD HELP TO BOOST TEMPERATURES GOING INTO THE EVENING
HOURS.
NO BIG CHANGES IN TO THE FRONTAL PASSAGE TONIGHT...AT LEAST WITH
THIS ROUND OF UPDATES. MODELS REMAIN LARGELY CONSISTENT WITH
TIMING AND NOW THAT THE HRRR HAS SOMETHING TO LATCH ONTO...IT
TELLS A SIMILAR STORY IN TIMING THE COLD FRONT THROUGH OUR AREA.
STILL EXPECTING TEMPERATURES TO DROP OFF QUICKLY BEHIND THE FRONT
SUNDAY UNDER DECENT CAA. ALL SIGNS POINT TO MOST OF THE MOISTURE
ERODING QUICKLY BEHIND THE FRONT...HOWEVER...THE 12Z NAM HOLDS
BACK ENOUGH MOISTURE THAT A FEW HOURS OF RAIN TRANSITIONING TO SNOW COULD
OCCUR AROUND MID MORNING SUNDAY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
THE COLD FRONT THAT WILL MOVE THOUGH OUR AREA TONIGHT WILL STALL
OUT OVER OR JUST EAST OF THE APPALACHIANS. THIS WILL SERVE AS THE
TRACK FOR A SW TROUGH SUNDAY NIGHT INTO MONDAY THAT THE MODELS
HAVE HAD A DIFFICULT TIME HANDLING TO THIS POINT. GUIDANCE ON
PREVIOUS DAYS HAD THE COLD FRONT PUSHING WELL TO OUR SOUTHEAST
WITH AMPLE HIGH PRESSURE FILLING IN BEHIND IT. THIS HAD HELPED TO
PUSH A POTENTIALLY POTENT WINTER STORM WELL TO OUR SOUTH. MODELS
HAVE WAFFLED ON THE EXACT PLACEMENT OF THE COLD FRONT AND
SUBSEQUENTLY THE TRACK OF THE SW.
NOW THERE IS AT LEAST A LITTLE CONVERGENCE ON A SOLN THAT KEEPS
THE MOISTURE ASSOCIATED WITH TODAYS FRONT IN OUR SE RIDGES WHICH
WILL SERVE TO FUEL THE SYSTEM THAT HAS THE 500MB VORT MAX PASSING
THROUGH WV. AS THE SYSTEM APPROACHES IT WILL BE AIDED ALOFT BY
STRONG DIVERGENCE ASSOCIATED WITH PHASING OF THE 300MB JET
STREAKS. SEVERAL HOURS OF LIGHT TO MODERATE SNOW IS EXPECTED
NEAR OUR SE CWA LINE...WITH HIGHER TOTALS PROGGED FOR LWX AND
RLX. WILL CARRY A MENTION IN THE HWO FOR NOW WITH ADVISORY
LEVEL SNOW TOTALS IN THIS UPDATE AND CONFIDENCE OF IMPACT TO OUR
AREA STILL A LITTLE LOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ALTHOUGH MONDAY NIGHT WILL BE DRY...MOISTURE WILL MOVE INTO THE
REGION TUESDAY AFTERNOON/EVENING WITH LOW PRESSURE MOVING THROUGH
THE MISSISSIPPI AND OHIO RIVER VALLEYS. AS ENERGY IS EXPECTED TO
TRANSFER FROM THE RIVER VALLEY LOW TO AN OFFSHORE LOW...WHEN THIS
TRANSITION OCCURS WILL BE KEY TO THE LOCAL IMPACTS. CURRENT
TEMPERATURE FORECASTS WOULD ALLOW THE PRECIPITATION TO START AS RAIN
IN MOST LOCATIONS...BUT LIKELY TURN OVER TO SNOW IN MOST LOCATIONS
AS WELL. 00Z GFS/ECMWF SHOW HUGE DIFFERENCES IN AMOUNT OF LIQUID
PRECIPITATION FORECAST FOR THE REGION...SO THIS IS STILL A LOW
CONFIDENCE FORECAST.
PRECIPITATION IS EXPECTED TO WIND DOWN WEDNESDAY AFTERNOON...WITH
HIGH PRESSURE EXPECTED TO KEEP CONDITIONS DRY THURSDAY AND FRIDAY.
GFS AND ECMWF ALSO SHOW WILDLY DIFFERENT TEMPERATURE FORECASTS AFTER
THE LOW PRESSURE SYSTEM ON WEDNESDAY. AT THIS POINT...HAVE GONE
WITH FORECASTS WHERE TEMPS ARE ABOUT 10 DEGREES BELOW NORMAL...WHICH
WILL PROBABLY STILL FEEL WARM AFTER THE TEMPERATURES EXPERIENCED
THIS PAST WEEK.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
VFR WITH ONLY A FEW SPRINKLES AROUND KDUJ THIS AFTERNOON AS AREA
IS WELL INTO THE WARM SECTOR AHEAD OF SURFACE LOW IN SRN IL. AS
LOW MOVES NORTHEAST THIS EVENING COLD FRONT WILL SWING SOUTHEAST
WITH LIGHT RAIN MIXING WITH SNOW THEN CHANGING TO SNOW NORTHWEST
TO SOUTHEAST FROM PRE-DAWN TO EARLY MORNING SUNDAY. CONDITIONS
DETERIORATING QUICKLY TO IFR OVERNIGHT IN RAIN AND MIX PRECIP. AS
FRONT BEGINS TO SLOW SUNDAY IN ADVANCE OF A WAVE MOVING ALONG
FRONT EXPECT KMGW TO BE THE LAST TO CHANGE OVER TO ALL SNOW. IFR
CIGS THROUGH SUNDAY. WENT WITH IFR VSBY IN SNOW AS WELL BUT EXACT
TIMING OF CHANGEOVER AND LOWER VSBY IS IN DOUBT. WINDS SOUTHWEST
THIS EVENING BECOMING NORTHWEST LATER TONIGHT AND SUNDAY MOSTLY
UNDER 10 KTS.
.OUTLOOK..../SUNDAY NIGHT THURSDAY/...
BEST CHANCE FOR RESTRICTIONS SUNDAY NIGHT INTO MONDAY AT KMGW AS
WAVE MOVING ALONG COLD FRONT SPREADS SNOW ACROSS THE MASON DIXON
LINE.
GENERAL VFR TUESDAY...THEN RESTRICTIONS POSSIBLE TUESDAY NIGHT AND
WEDNESDAY IN RAIN AND OR SNOW. IMPROVEMENT TO VFR DURING THE DAY THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1245 PM EST SAT FEB 1 2014
.SYNOPSIS...
ABOVE NORMAL TEMPERATURES CAN BE EXPECTED TODAY BEFORE A
COLD FRONT RESULTS IN RAIN OVERNIGHT CHANGING OVER TO LIGHT SNOW
WITH NO SIGNIFICANT ACCUMULATIONS SUNDAY MORNING.
&&
.NEAR TERM /THROUGH SUNDAY/...
CURRENT SATELLITE IMAGE HAS OUR AREA BLANKETED IN CLOUD COVER AS
A WARM FRONT PUSHES SLOWLY TO THE NORTH. RADAR STILL IS MORE BARK
THAN BITE...AS MUCH OF THE ECHOES VISIBLE ARE VIRGA AS DRY AIR
REMAINS LOCKED IN FROM SFC TO ABOUT 900MB...EVIDENT FROM THE 12Z
SOUNDING AND THE NEARLY 15 DEGREE DEW POINT SPREAD ON CURRENT OBS.
ALTHOUGH THE CLOUD COVER REMAINS...AM EXPECTING THE LOW LEVEL FLOW
TO STIFFEN FROM THE SOUTH AND CLEAR AT LEAST A PORTION OF OUR
SOUTH TO PARTLY CLOUDY. THIS SOUTHERLY FLOW...COMBINED WITH SOME
SUN SHOULD HELP TO BOOST TEMPERATURES GOING INTO THE EVENING
HOURS.
NO BIG CHANGES IN TO THE FRONTAL PASSAGE TONIGHT...AT LEAST WITH
THIS ROUND OF UPDATES. MODELS REMAIN LARGELY CONSISTENT WITH
TIMING AND NOW THAT THE HRRR HAS SOMETHING TO LATCH ONTO...IT
TELLS A SIMILAR STORY IN TIMING THE COLD FRONT THROUGH OUR AREA.
STILL EXPECTING TEMPERATURES TO DROP OFF QUICKLY BEHIND THE FRONT
SUNDAY UNDER DECENT CAA. ALL SIGNS POINT TO MOST OF THE MOISTURE
ERODING QUICKLY BEHIND THE FRONT...HOWEVER...THE 12Z NAM HOLDS
BACK ENOUGH MOISTURE THAT A FEW HOURS OF RAIN TRANSITIONING TO SNOW COULD
OCCUR AROUND MID MORNING SUNDAY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
A COLD FRONT WILL QUICKLY SWEEP THROUGH THE FORECAST AREA
OVERNIGHT AND SUNDAY MORNING. TEMPERATURES ALOFT AND AT THE
SURFACE DO NOT SUPPORT SNOW UNTIL THE FRONT IS WELL THROUGH AND
WITH MOISTURE DECREASING SIGNIFICANTLY BEHIND THE FRONT DO NOT
EXPECT ANY SIGNIFICANT SNOW ACCUMULATIONS. THE VAST MAJORITY OF
AREAS THAT DO SEE SNOW WILL LIKELY SEE LESS THAN HALF AN INCH.
A SHORTWAVE ON THE HEELS OF THE COLD FRONT WILL PASS OVER SUNDAY
NIGHT AND MONDAY BUT WITH THE BULK OF MOISTURE WELL TO THE SOUTH
DO NOT ANTICIPATE ANY PRECIP OUTSIDE OF ALONG THE SOUTHEAST
RIDGES. EVEN THEN...SNOW WILL BE RELATIVELY LIGHT WITH ONLY UP TO
AN INCH POSSIBLE BY NOON ON MONDAY. THAT BEING SAID...IF MODELS
TREND ANY FARTHER NORTH AT ALL THERE WOULD BE MORE MOISTURE TO
WORK WITH AND WOULD PUT THE SOUTHERN EDGE OF THE CWA UNDER THE
RIGHT-REAR QUADRANT OF THE UPPER LEVEL JET...AND WOULD LIKELY NEED
TO INCREASE COVERAGE AND SNOW AMOUNTS. FOR NOW OPTED TO JUST
CONTINUE A SLIGHT CHANCE TO CHANCE OF PRECIP AND LOW QPF AMOUNTS
IN THE FORECAST FOR SOUTHEAST ZONES.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ALTHOUGH MONDAY NIGHT WILL BE DRY...MOISTURE WILL MOVE INTO THE
REGION TUESDAY AFTERNOON/EVENING WITH LOW PRESSURE MOVING THROUGH
THE MISSISSIPPI AND OHIO RIVER VALLEYS. AS ENERGY IS EXPECTED TO
TRANSFER FROM THE RIVER VALLEY LOW TO AN OFFSHORE LOW...WHEN THIS
TRANSITION OCCURS WILL BE KEY TO THE LOCAL IMPACTS. CURRENT
TEMPERATURE FORECASTS WOULD ALLOW THE PRECIPITATION TO START AS RAIN
IN MOST LOCATIONS...BUT LIKELY TURN OVER TO SNOW IN MOST LOCATIONS
AS WELL. 00Z GFS/ECMWF SHOW HUGE DIFFERENCES IN AMOUNT OF LIQUID
PRECIPITATION FORECAST FOR THE REGION...SO THIS IS STILL A LOW
CONFIDENCE FORECAST.
PRECIPITATION IS EXPECTED TO WIND DOWN WEDNESDAY AFTERNOON...WITH
HIGH PRESSURE EXPECTED TO KEEP CONDITIONS DRY THURSDAY AND FRIDAY.
GFS AND ECMWF ALSO SHOW WILDLY DIFFERENT TEMPERATURE FORECASTS AFTER
THE LOW PRESSURE SYSTEM ON WEDNESDAY. AT THIS POINT...HAVE GONE
WITH FORECASTS WHERE TEMPS ARE ABOUT 10 DEGREES BELOW NORMAL...WHICH
WILL PROBABLY STILL FEEL WARM AFTER THE TEMPERATURES EXPERIENCED
THIS PAST WEEK.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR WITH ONLY A FEW SPRINKLES AROUND KDUJ THIS AFTERNOON AS AREA
IS WELL INTO THE WARM SECTOR AHEAD OF SURFACE LOW IN SRN IL. AS
LOW MOVES NORTHEAST THIS EVENING COLD FRONT WILL SWING SOUTHEAST
WITH LIGHT RAIN MIXING WITH SNOW THEN CHANGING TO SNOW NORTHWEST
TO SOUTHEAST FROM PRE-DAWN TO EARLY MORNING SUNDAY. CONDITIONS
DETERIORATING QUICKLY TO IFR OVERNIGHT IN RAIN AND MIX PRECIP. AS
FRONT BEGINS TO SLOW SUNDAY IN ADVANCE OF A WAVE MOVING ALONG
FRONT EXPECT KMGW TO BE THE LAST TO CHANGE OVER TO ALL SNOW. IFR
CIGS THROUGH SUNDAY. WENT WITH IFR VSBY IN SNOW AS WELL BUT EXACT
TIMING OF CHANGEOVER AND LOWER VSBY IS IN DOUBT. WINDS SOUTHWEST
THIS EVENING BECOMING NORTHWEST LATER TONIGHT AND SUNDAY MOSTLY
UNDER 10 KTS.
.OUTLOOK..../SUNDAY NIGHT THURSDAY/...
BEST CHANCE FOR RESTRICTIONS SUNDAY NIGHT INTO MONDAY AT KMGW AS
WAVE MOVING ALONG COLD FRONT SPREADS SNOW ACROSS THE MASON DIXON
LINE.
GENERAL VFR TUESDAY...THEN RESTRICTIONS POSSIBLE TUESDAY NIGHT AND
WEDNESDAY IN RAIN AND OR SNOW. IMPROVEMENT TO VFR DURING THE DAY THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1044 AM EST SAT FEB 1 2014
.SYNOPSIS...
ABOVE NORMAL TEMPERATURES CAN BE EXPECTED TODAY BEFORE A
COLD FRONT RESULTS IN RAIN OVERNIGHT CHANGING OVER TO LIGHT SNOW
WITH NO SIGNIFICANT ACCUMULATIONS SUNDAY MORNING.
&&
.NEAR TERM /THROUGH SUNDAY/...
CURRENT SATELLITE IMAGE HAS OUR AREA BLANKETED IN CLOUD COVER AS
A WARM FRONT PUSHES SLOWLY TO THE NORTH. RADAR STILL IS MORE BARK
THAN BITE...AS MUCH OF THE ECHOES VISIBLE ARE VIRGA AS DRY AIR
REMAINS LOCKED IN FROM SFC TO ABOUT 900MB...EVIDENT FROM THE 12Z
SOUNDING AND THE NEARLY 15 DEGREE DEW POINT SPREAD ON CURRENT OBS.
ALTHOUGH THE CLOUD COVER REMAINS...AM EXPECTING THE LOW LEVEL FLOW
TO STIFFEN FROM THE SOUTH AND CLEAR AT LEAST A PORTION OF OUR
SOUTH TO PARTLY CLOUDY. THIS SOUTHERLY FLOW...COMBINED WITH SOME
SUN SHOULD HELP TO BOOST TEMPERATURES GOING INTO THE EVENING
HOURS.
NO BIG CHANGES IN TO THE FRONTAL PASSAGE TONIGHT...AT LEAST WITH
THIS ROUND OF UPDATES. MODELS REMAIN LARGELY CONSISTENT WITH
TIMING AND NOW THAT THE HRRR HAS SOMETHING TO LATCH ONTO...IT
TELLS A SIMILAR STORY IN TIMING THE COLD FRONT THROUGH OUR AREA.
STILL EXPECTING TEMPERATURES TO DROP OFF QUICKLY BEHIND THE FRONT
SUNDAY UNDER DECENT CAA. ALL SIGNS POINT TO MOST OF THE MOISTURE
ERODING QUICKLY BEHIND THE FRONT...HOWEVER...THE 12Z NAM HOLDS
BACK ENOUGH MOISTURE THAT A FEW HOURS OF RAIN TRANSITIONING TO SNOW COULD
OCCUR AROUND MID MORNING SUNDAY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
A COLD FRONT WILL QUICKLY SWEEP THROUGH THE FORECAST AREA
OVERNIGHT AND SUNDAY MORNING. TEMPERATURES ALOFT AND AT THE
SURFACE DO NOT SUPPORT SNOW UNTIL THE FRONT IS WELL THROUGH AND
WITH MOISTURE DECREASING SIGNIFICANTLY BEHIND THE FRONT DO NOT
EXPECT ANY SIGNIFICANT SNOW ACCUMULATIONS. THE VAST MAJORITY OF
AREAS THAT DO SEE SNOW WILL LIKELY SEE LESS THAN HALF AN INCH.
A SHORTWAVE ON THE HEELS OF THE COLD FRONT WILL PASS OVER SUNDAY
NIGHT AND MONDAY BUT WITH THE BULK OF MOISTURE WELL TO THE SOUTH
DO NOT ANTICIPATE ANY PRECIP OUTSIDE OF ALONG THE SOUTHEAST
RIDGES. EVEN THEN...SNOW WILL BE RELATIVELY LIGHT WITH ONLY UP TO
AN INCH POSSIBLE BY NOON ON MONDAY. THAT BEING SAID...IF MODELS
TREND ANY FARTHER NORTH AT ALL THERE WOULD BE MORE MOISTURE TO
WORK WITH AND WOULD PUT THE SOUTHERN EDGE OF THE CWA UNDER THE
RIGHT-REAR QUADRANT OF THE UPPER LEVEL JET...AND WOULD LIKELY NEED
TO INCREASE COVERAGE AND SNOW AMOUNTS. FOR NOW OPTED TO JUST
CONTINUE A SLIGHT CHANCE TO CHANCE OF PRECIP AND LOW QPF AMOUNTS
IN THE FORECAST FOR SOUTHEAST ZONES.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ALTHOUGH MONDAY NIGHT WILL BE DRY...MOISTURE WILL MOVE INTO THE
REGION TUESDAY AFTERNOON/EVENING WITH LOW PRESSURE MOVING THROUGH
THE MISSISSIPPI AND OHIO RIVER VALLEYS. AS ENERGY IS EXPECTED TO
TRANSFER FROM THE RIVER VALLEY LOW TO AN OFFSHORE LOW...WHEN THIS
TRANSITION OCCURS WILL BE KEY TO THE LOCAL IMPACTS. CURRENT
TEMPERATURE FORECASTS WOULD ALLOW THE PRECIPITATION TO START AS RAIN
IN MOST LOCATIONS...BUT LIKELY TURN OVER TO SNOW IN MOST LOCATIONS
AS WELL. 00Z GFS/ECMWF SHOW HUGE DIFFERENCES IN AMOUNT OF LIQUID
PRECIPITATION FORECAST FOR THE REGION...SO THIS IS STILL A LOW
CONFIDENCE FORECAST.
PRECIPITATION IS EXPECTED TO WIND DOWN WEDNESDAY AFTERNOON...WITH
HIGH PRESSURE EXPECTED TO KEEP CONDITIONS DRY THURSDAY AND FRIDAY.
GFS AND ECMWF ALSO SHOW WILDLY DIFFERENT TEMPERATURE FORECASTS AFTER
THE LOW PRESSURE SYSTEM ON WEDNESDAY. AT THIS POINT...HAVE GONE
WITH FORECASTS WHERE TEMPS ARE ABOUT 10 DEGREES BELOW NORMAL...WHICH
WILL PROBABLY STILL FEEL WARM AFTER THE TEMPERATURES EXPERIENCED
THIS PAST WEEK.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
SOME MVFR CONDITIONS IN LIGHT SNOW COULD OCCUR DURING THE MORNING
HOURS AT ZZV/BVI/FKL. BY THE AFTERNOON ALL SITES WILL HAVE A MID
LEVEL DECK. AS A COLD FRONT MOVES INTO THE REGION FROM NORTHWEST
TO SOUTHEAST...RAIN WILL OVERSPREAD TERMINALS. ANTICIPATE THAT
AFTER A FEW HOURS OF RAIN...CEILINGS WILL DROP TO IFR LEVELS.
.OUTLOOK..../SUNDAY THROUGH WEDNESDAY/...
AS THE COLD FRONT COMPLETES ITS PASSAGE SUNDAY...RAIN COULD POSSIBLY
MIX WITH SNOW. VFR IS EXPECTED SUNDAY NIGHT THROUGH
TUESDAY...ALTHOUGH MGW COULD POSSIBLY SEE RESTRICTIONS AS A SYSTEM
PASSES TO THE SOUTHEAST. RAIN AND SNOW WILL ENTER THE REGION FROM
SOUTH TO NORTH TUESDAY AND WEDNESDAY...WITH RESTRICTIONS EXPECTED.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1225 PM EST SAT FEB 1 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 318 AM EST SAT FEB 1 2014
A SNOWY DAY IS EXPECTED ACROSS LOWER MICHIGAN WITH 3 TO 6 INCHES
EXPECTED SOUTH OF A GRAND HAVEN TO ALMA LINE. LIGHT WINDS ARE
EXPECTED TODAY SO BLOWING AND DRIFTING WON`T BE AN ISSUE.
TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH NEXT WEEK WITH HIGHS
IN THE TEENS AND TWENTIES. ANOTHER STORM SYSTEM MAY GENERATE
ACCUMULATING SNOW MIDWEEK.
&&
.UPDATE...
ISSUED AT 1115 AM EST SAT FEB 1 2014
THERE IS ALREADY A VERY DISTINCT BACK EDGE TO THE WIDESPREAD
HEAVIER PRECIP SHOWING UP IN RADAR MOSAIC IMAGERY APPROACHING FROM
THE WEST AND SOUTHWEST. THEREFORE BACKED DOWN ON STORM TOTAL
ACCUMULATIONS... FEATURING 4-6 ALONG THE I-94 CORRIDOR... 3-5
ALONG THE I-96 CORRIDOR... AND 2 TO 4 NORTH OF THERE. EVEN THIS
MAY BE A BIT AMBITIOUS.
VISIBILITIES HAVE IMPROVED CONSIDERABLY ALREADY ACROSS NRN IL AND
SRN WI SO LOOK FOR LIGHTER MORE INTERMITTENT SNOWS AFTER THE
WIDESPREAD HEAVIER SNOW EXITS EARLY THIS AFTERNOON. CONTINUED MID
LEVEL FGEN FORCING MAY STILL LEAD TO THE REDEVELOPMENT OF SOME
BANDS OF BETTER INTENSITY THROUGH EARLY EVENING...BUT THE GENERAL
OVERALL TREND UPSTREAM ON RADAR/SATELLITE/SFC OBS IS NOT REALLY
ENCOURAGING FOR ADDITIONAL WIDESPREAD HEAVY SNOW.
LATEST RUC SOUNDINGS KEEP THINGS ALL SNOW THIS AFTERNOON EVEN
AROUND JXN SO WILL REMOVE THE MENTION OF SLEET IN THE FAR SE CWFA.
ALSO WE ARE NOT LOOKING AT NEARLY THE TOTAL AMOUNT OF WATER
EQUIVALENT THE MODELS WERE SUGGESTING ALTHOUGH UP TO 0.50 TOTAL
STILL POSSIBLE FROM BTL TO JXN. THAT IS GOOD NEWS AS FAR AS
LOWERING THE AMOUNT ADDITIONAL SNOW LOAD ON ALREADY BURDENED FLAT
ROOFS FROM THE NUMEROUS PREVIOUS EVENTS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 318 AM EST SAT FEB 1 2014
FORECAST CONCERNS DEAL WITH THE UNFOLDING SNOW EVENT.
KGRR BEGAN SHOWING LIGHT SNOW MOVING INTO SOUTHERN LOWER MICHIGAN
LAST EVENING. HOWEVER...A BROADER RADAR DEPICTION REVEALED THAT THE
LEADING EDGE OF THE MAIN AREA OF SNOW ASSOCIATED WITH THE LOW MOVING
OUT OF THE SOUTHERN PLAINS WAS ACTUALLY IN NORTHERN MISSOURI. I
WOULD EXPECT THE SNOW TO INTENSIFY BY 12Z. CROSS SECTIONS SHOW
STRONG LIFT COINCIDING WITH THE DGZ FROM MID MORNING THROUGH MID
AFTERNOON. MIXING RATIOS WITH THIS SYSTEM ARE 3-4 G/KG WHICH SHOULD
MAKE THIS SNOW A FAIRLY WET AND HEAVY ONE. TWEAKED QPF AND SNOW
RATIOS BUT STILL CAME UP WITH A GENERAL 5-7 INCH SNOW ACROSS
PORTIONS OF THE CENTRAL CWA FROM ALLEGAN TO ALMA. LOWER SNOW RATIOS
OVER THE SRN CWA SHOULD LIMIT ACCUMS A BIT.
BASED ON FORECAST SOUNDINGS...THE THREAT FOR FREEZING RAIN SEEMS
VERY LIMITED...MORE OF A CHANCE OF SLEET AND SO GRIDS REFLECT THAT.
SNOW ACCUMS WILL DIMINISH OVER THE NRN CWA FARTHER AWAY FROM THE
TRACK OF THE LOW.
OVERALL...THIS STILL LOOKS TO ME LIKE A HIGH END ADVISORY. THIS
WON/T BE LIKE LAST WEEK WHEN WE SAW 5-7 INCHES OF SNOW AND 40-50 MPH
WINDS. TODAY/S EVENT WILL NOT HAVE MUCH WIND WITH IT AND THUS
IMPACTS WILL BE MUCH LESS.
COLDER AIR WILL FLOW INTO THE CWA BEHIND THE LOW LATER TONIGHT AND
SUNDAY. WE/LL SEE SOME LAKE EFFECT SNOW DEVELOP BUT NOT EXPECTING
MUCH AS FETCH DECREASES DUE TO ICE AND LIMITED INSTABILITY OVER THE
LAKE.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 318 AM EST SAT FEB 1 2014
A WINTER STORM WILL TRACK ACROSS THE OHIO VALLEY TUESDAY NIGHT INTO
WEDNESDAY AND BRING MORE SNOW TO SOUTHERN LOWER MICHIGAN. THE LOW
WILL TRACK FURTHER SOUTH THAN THE CURRENT STORM BUT IT WILL BE MORE
WOUND UP AND SHOULD HAVE A LARGE AREA OF MID LEVEL FRONTOGENETIC
FORCING REACHING INTO THE SOUTHERN HALF OF LOWER MICHIGAN.
FORECAST CONFIDENCE IS RELATIVELY HIGH AS THERE IS VERY GOOD
CONSISTENCY IN THE TRACK AND TIMING OF THE SFC LOW WITH THE 00Z EURO
AND GFS. WE WILL BE ON THE NORTHERN FRINGE OF THE HEAVIER SNOW WITH
THE POTENTIAL FOR UP TO 6 INCHES OF SNOW ACROSS THE SOUTHEAST ZONES
WITH LESSER AMOUNTS NORTH.
THE LOW PULLS AWAY THURSDAY FOLLOWED BY MORE LAKE EFFECT SNOW
SHOWERS...BUT ACCUMULATIONS SHOULD BE LIMITED AS ONCE AGAIN THE DGZ
IS CRASHING TOWARDS THE GROUND AS THE ARCTIC AIR ARRIVES AND
INVERSION HEIGHTS ARE PROGGED TO BE BELOW 5 KFT AGL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY)
ISSUED AT 1225 PM EST SAT FEB 1 2014
HIGHLY VARIABLE CONDITIONS RANGING FROM IFR/MVFR AT KGRR... KAZO AND
KMKG EARLY THIS AFTERNOON WHERE MOST OF THE SNOW HAS ENDED TO LIFR
AT OUR SE TERMINALS THROUGH MID AFTERNOON WHERE MODERATE TO HEAVY
SNOW WILL CONTINUE FOR A FEW MORE HOURS BEFORE TAPERING OFF LATE
THIS AFTERNOON.
MAINLY MVFR CONDITIONS ANTICIPATED TONIGHT DUE TO LOW CLOUDS AND
FLURRIES. CONDITIONS SHOULD REMAIN MVFR SUNDAY MORNING BEFORE
POTENTIALLY IMPROVING TO VFR TOWARD MIDDAY SUNDAY/SUNDAY AFTERNOON.
WIND SPEEDS AOB 10 KTS THROUGH 18Z SUN.
&&
.MARINE...
ISSUED AT 329 PM EST FRI JAN 31 2014
MOST OF THE NEARSHORE IS ICE COVERED.
&&
.HYDROLOGY...
ISSUED AT 329 PM EST FRI JAN 31 2014
WE WILL BE ADDING BETWEEN 0.25-0.50" ONTO THE MUSKEGON RIVER BASIN
AND 0.50-0.75" ONTO THE GRAND AND ST. JOSEPH RIVER BASINS THROUGH
SATURDAY NIGHT MAINLY IN THE FORM OF SNOW. SOME OF THIS QPF ACCOUNTS
FOR RAIN/FREEZING RAIN MAINLY NEAR THE HEADWATERS OF THE GRAND BY
JACKSON. WE`LL NEED TO MONITOR THE JACKSON GAGE FOR SOME SMALL
RISES...BUT NOTHING MAJOR AT THIS POINT. ELSEWHERE...THIS SNOW WILL
FALL ONTO EXISTING ICE AND SNOW COVERED RIVERS...FURTHER THICKENING
THE COVER THAT IS IN PLACE. THE SNOWPACK AND ICEPACK WILL CONTINUE
TO BUILD INTO NEXT WEEK.
STABLE ICE DEVELOPMENT WILL CONTINUE DUE TO A PROLONGED PERIOD OF
COLD WEATHER. THE ICE JAM THREAT IS LOW AND THERE IS NO CURRENT
INDICATIONS OF ANY ICE JAMS ON THE RIVER NETWORK. DUE TO THE EXTREME
COLD TEMPERATURES OVER THE PAST SEVERAL WEEKS...RIVER GAGES ARE
FREEZING UP ACROSS THE AREA. WHEN RIVER GAGES FREEZE UP...THE
READINGS GO FLAT LINED AND NO LONGER REFLECT THE TRUE RIVER LEVELS.
RIVER GAGES THAT HAVE CURRENTLY FLAT LINED ARE THE WHITE RIVER AT
WHITEHALL... BATTLE CREEK AT BATTLE CREEK...THORNAPPLE RIVER NEAR
CALEDONIA...ROGUE RIVER NEAR ROCKFORD... AND THE RED CEDAR RIVER
NEAR WILLIAMSTON. FOR RIVER GAGES NOT FROZEN...RIVERS LEVELS ARE
STEADY OR SLOWLY FALLING ACROSS THE AREA.
AT SOME STATIONS... THE SYSTEMS USED TO SENSE WATER STAGE ARE
SUSCEPTIBLE TO ERRONEOUS READINGS DURING PERIODS OF EXTREME COLD
TEMPERATURES. STAGE HYDROGRAPHS DURING SUCH TIMES SHOW RAPID
FLUCTUATIONS IN WATER LEVELS AND SUBSEQUENT RAPID RETURN TO PREVIOUS
LEVELS WHEN SLIGHTLY WARMER TEMPERATURES RETURN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MIZ037>040-043>046-050>052-056>059-064>067-071>074.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...93
SHORT TERM...93
LONG TERM...OSTUNO
AVIATION...LAURENS
HYDROLOGY...HOVING
MARINE...MEADE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1116 AM EST SAT FEB 1 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 318 AM EST SAT FEB 1 2014
A SNOWY DAY IS EXPECTED ACROSS LOWER MICHIGAN WITH 3 TO 6 INCHES
EXPECTED SOUTH OF A GRAND HAVEN TO ALMA LINE. LIGHT WINDS ARE
EXPECTED TODAY SO BLOWING AND DRIFTING WON`T BE AN ISSUE.
TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH NEXT WEEK WITH HIGHS
IN THE TEENS AND TWENTIES. ANOTHER STORM SYSTEM MAY GENERATE
ACCUMULATING SNOW MIDWEEK.
&&
.UPDATE...
ISSUED AT 1115 AM EST SAT FEB 1 2014
THERE IS ALREADY A VERY DISTINCT BACK EDGE TO THE WIDESPREAD
HEAVIER PRECIP SHOWING UP IN RADAR MOSAIC IMAGERY APPROACHING FROM
THE WEST AND SOUTHWEST. THEREFORE BACKED DOWN ON STORM TOTAL
ACCUMULATIONS... FEATURING 4-6 ALONG THE I-94 CORRIDOR... 3-5
ALONG THE I-96 CORRIDOR... AND 2 TO 4 NORTH OF THERE. EVEN THIS
MAY BE A BIT AMBITIOUS.
VISIBILITIES HAVE IMPROVED CONSIDERABLY ALREADY ACROSS NRN IL AND
SRN WI SO LOOK FOR LIGHTER MORE INTERMITTENT SNOWS AFTER THE
WIDESPREAD HEAVIER SNOW EXITS EARLY THIS AFTERNOON. CONTINUED MID
LEVEL FGEN FORCING MAY STILL LEAD TO THE REDEVELOPMENT OF SOME
BANDS OF BETTER INTENSITY THROUGH EARLY EVENING...BUT THE GENERAL
OVERALL TREND UPSTREAM ON RADAR/SATELLITE/SFC OBS IS NOT REALLY
ENCOURAGING FOR ADDITIONAL WIDESPREAD HEAVY SNOW.
LATEST RUC SOUNDINGS KEEP THINGS ALL SNOW THIS AFTERNOON EVEN
AROUND JXN SO WILL REMOVE THE MENTION OF SLEET IN THE FAR SE CWFA.
ALSO WE ARE NOT LOOKING AT NEARLY THE TOTAL AMOUNT OF WATER
EQUIVALENT THE MODELS WERE SUGGESTING ALTHOUGH UP TO 0.50 TOTAL
STILL POSSIBLE FROM BTL TO JXN. THAT IS GOOD NEWS AS FAR AS
LOWERING THE AMOUNT ADDITIONAL SNOW LOAD ON ALREADY BURDENED FLAT
ROOFS FROM THE NUMEROUS PREVIOUS EVENTS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 318 AM EST SAT FEB 1 2014
FORECAST CONCERNS DEAL WITH THE UNFOLDING SNOW EVENT.
KGRR BEGAN SHOWING LIGHT SNOW MOVING INTO SOUTHERN LOWER MICHIGAN
LAST EVENING. HOWEVER...A BROADER RADAR DEPICTION REVEALED THAT THE
LEADING EDGE OF THE MAIN AREA OF SNOW ASSOCIATED WITH THE LOW MOVING
OUT OF THE SOUTHERN PLAINS WAS ACTUALLY IN NORTHERN MISSOURI. I
WOULD EXPECT THE SNOW TO INTENSIFY BY 12Z. CROSS SECTIONS SHOW
STRONG LIFT COINCIDING WITH THE DGZ FROM MID MORNING THROUGH MID
AFTERNOON. MIXING RATIOS WITH THIS SYSTEM ARE 3-4 G/KG WHICH SHOULD
MAKE THIS SNOW A FAIRLY WET AND HEAVY ONE. TWEAKED QPF AND SNOW
RATIOS BUT STILL CAME UP WITH A GENERAL 5-7 INCH SNOW ACROSS
PORTIONS OF THE CENTRAL CWA FROM ALLEGAN TO ALMA. LOWER SNOW RATIOS
OVER THE SRN CWA SHOULD LIMIT ACCUMS A BIT.
BASED ON FORECAST SOUNDINGS...THE THREAT FOR FREEZING RAIN SEEMS
VERY LIMITED...MORE OF A CHANCE OF SLEET AND SO GRIDS REFLECT THAT.
SNOW ACCUMS WILL DIMINISH OVER THE NRN CWA FARTHER AWAY FROM THE
TRACK OF THE LOW.
OVERALL...THIS STILL LOOKS TO ME LIKE A HIGH END ADVISORY. THIS
WON/T BE LIKE LAST WEEK WHEN WE SAW 5-7 INCHES OF SNOW AND 40-50 MPH
WINDS. TODAY/S EVENT WILL NOT HAVE MUCH WIND WITH IT AND THUS
IMPACTS WILL BE MUCH LESS.
COLDER AIR WILL FLOW INTO THE CWA BEHIND THE LOW LATER TONIGHT AND
SUNDAY. WE/LL SEE SOME LAKE EFFECT SNOW DEVELOP BUT NOT EXPECTING
MUCH AS FETCH DECREASES DUE TO ICE AND LIMITED INSTABILITY OVER THE
LAKE.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 318 AM EST SAT FEB 1 2014
A WINTER STORM WILL TRACK ACROSS THE OHIO VALLEY TUESDAY NIGHT INTO
WEDNESDAY AND BRING MORE SNOW TO SOUTHERN LOWER MICHIGAN. THE LOW
WILL TRACK FURTHER SOUTH THAN THE CURRENT STORM BUT IT WILL BE MORE
WOUND UP AND SHOULD HAVE A LARGE AREA OF MID LEVEL FRONTOGENETIC
FORCING REACHING INTO THE SOUTHERN HALF OF LOWER MICHIGAN.
FORECAST CONFIDENCE IS RELATIVELY HIGH AS THERE IS VERY GOOD
CONSISTENCY IN THE TRACK AND TIMING OF THE SFC LOW WITH THE 00Z EURO
AND GFS. WE WILL BE ON THE NORTHERN FRINGE OF THE HEAVIER SNOW WITH
THE POTENTIAL FOR UP TO 6 INCHES OF SNOW ACROSS THE SOUTHEAST ZONES
WITH LESSER AMOUNTS NORTH.
THE LOW PULLS AWAY THURSDAY FOLLOWED BY MORE LAKE EFFECT SNOW
SHOWERS...BUT ACCUMULATIONS SHOULD BE LIMITED AS ONCE AGAIN THE DGZ
IS CRASHING TOWARDS THE GROUND AS THE ARCTIC AIR ARRIVES AND
INVERSION HEIGHTS ARE PROGGED TO BE BELOW 5 KFT AGL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 647 AM EST SAT FEB 1 2014
SNOW WILL BRING WIDESPREAD IFR AND SOME LIFR THROUGH THE
AFTERNOON. THE WORST OF IT SHOULD BE AROUND 20Z TO 24Z. CONDITIONS
WILL IMPROVE DURING THE EVENING TO WIDESPREAD MVFR WITH AREAS OF IFR.
WINDS WILL BE EAST TO NORTHEAST TODAY AND NORTHWEST THIS EVENING
BUT AOB 10 KNOTS MOST OF THE TIME.
&&
.MARINE...
ISSUED AT 329 PM EST FRI JAN 31 2014
MOST OF THE NEARSHORE IS ICE COVERED.
&&
.HYDROLOGY...
ISSUED AT 329 PM EST FRI JAN 31 2014
WE WILL BE ADDING BETWEEN 0.25-0.50" ONTO THE MUSKEGON RIVER BASIN
AND 0.50-0.75" ONTO THE GRAND AND ST. JOSEPH RIVER BASINS THROUGH
SATURDAY NIGHT MAINLY IN THE FORM OF SNOW. SOME OF THIS QPF ACCOUNTS
FOR RAIN/FREEZING RAIN MAINLY NEAR THE HEADWATERS OF THE GRAND BY
JACKSON. WE`LL NEED TO MONITOR THE JACKSON GAGE FOR SOME SMALL
RISES...BUT NOTHING MAJOR AT THIS POINT. ELSEWHERE...THIS SNOW WILL
FALL ONTO EXISTING ICE AND SNOW COVERED RIVERS...FURTHER THICKENING
THE COVER THAT IS IN PLACE. THE SNOWPACK AND ICEPACK WILL CONTINUE
TO BUILD INTO NEXT WEEK.
STABLE ICE DEVELOPMENT WILL CONTINUE DUE TO A PROLONGED PERIOD OF
COLD WEATHER. THE ICE JAM THREAT IS LOW AND THERE IS NO CURRENT
INDICATIONS OF ANY ICE JAMS ON THE RIVER NETWORK. DUE TO THE EXTREME
COLD TEMPERATURES OVER THE PAST SEVERAL WEEKS...RIVER GAGES ARE
FREEZING UP ACROSS THE AREA. WHEN RIVER GAGES FREEZE UP...THE
READINGS GO FLAT LINED AND NO LONGER REFLECT THE TRUE RIVER LEVELS.
RIVER GAGES THAT HAVE CURRENTLY FLAT LINED ARE THE WHITE RIVER AT
WHITEHALL... BATTLE CREEK AT BATTLE CREEK...THORNAPPLE RIVER NEAR
CALEDONIA...ROGUE RIVER NEAR ROCKFORD... AND THE RED CEDAR RIVER
NEAR WILLIAMSTON. FOR RIVER GAGES NOT FROZEN...RIVERS LEVELS ARE
STEADY OR SLOWLY FALLING ACROSS THE AREA.
AT SOME STATIONS... THE SYSTEMS USED TO SENSE WATER STAGE ARE
SUSCEPTIBLE TO ERRONEOUS READINGS DURING PERIODS OF EXTREME COLD
TEMPERATURES. STAGE HYDROGRAPHS DURING SUCH TIMES SHOW RAPID
FLUCTUATIONS IN WATER LEVELS AND SUBSEQUENT RAPID RETURN TO PREVIOUS
LEVELS WHEN SLIGHTLY WARMER TEMPERATURES RETURN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MIZ037>040-043>046-050>052-056>059-064>067-071>074.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...93
SHORT TERM...93
LONG TERM...OSTUNO
AVIATION...OSTUNO
HYDROLOGY...HOVING
MARINE...MEADE
AREA FORECAST DISCUSSION
NWS BILLINGS MT
1059 PM MST FRI JAN 31 2014
.UPDATE...
HAVE UPDATED AGAIN TO INCLUDE SOUTHERN BIG HORN COUNTY IN THE
ADVISORY AS WELL...IN PARTICULAR THE WESTERN PORTION FROM PRYOR TO
FORT SMITH AS UPSLOPE ENHANCED SNOWFALL IS MODERATE TO HEAVY IN
THESE AREAS BASED ON RECENT BLX RADAR IMAGERY. SNOW CONTINUES
OTHERWISE ACROSS OUR WEST AND WILL MAKE NO OTHER CHANGES TO THE
WINTER HIGHLIGHTS. IT SHOULD ALSO BE NOTED THAT HEAVIER SNOWFALL
IS GETTING INTO THE RED LODGE AREA NOW AND MOIST UPSLOPE PCPN
WILL CONTINUE INTO SATURDAY MORNING...PERHAPS TIL CLOSE TO 17Z PER
THE LATEST RAP. JKL
PREVIOUS DISCUSSION ISSUED 916 PM...
UPDATED FORECAST EARLIER TO INCLUDE BILLINGS IN THE WINTER
WEATHER ADVISORY. RUC MODEL WAS CONSISTENTLY GENERATING .20 PRECIP
LIQUID AMOUNTS WHICH WITH CONSERVATIVE 15 TO 1 SNOW RATIOS WAS
GOING TO YIELD 3 INCHES AND SNOW RATIOS COULD BE HIGHER FOR THE
BILLINGS AREA. ELSEWHERE WEB CAMS AT BIG TIMBER AND RED LODGE SHOW
SNOW IS ACCUMULATING STEADILY SO THE ADVISORIES AND WARNINGS LOOK
GOOD. NO FURTHER UPDATES. BORSUM
&&
.SHORT TERM...VALID FOR SAT AND SUN...
PRESSURE RISES WERE NOSING INTO THE NW PORTION OF THE FORECAST
AREA THIS AFTERNOON HERALDING THE ARRIVAL OF THE NEXT COLD FRONT.
RADAR WAS STARTING TO FILL IN BEHIND THE FRONT ACROSS N MT WHILE
SPOTTY ECHOES WERE DEVELOPING OVER THE FORECAST AREA. A N-S
ORIENTED JET WILL WEAKEN AS IT DIVES S INTO THE REGION AND PUSHES
A SHORTWAVE AND THE COLD FRONT INTO THE AREA. THE SHORTWAVE WILL
HAVE SOME Q-VECTOR CONVERGENCE WITH IT TONIGHT INTO SAT MORNING.
TIME-HEIGHT CROSS SECTIONS AND BUFKIT BOTH SHOWED A SHALLOW LOW-
LEVEL DENDRITIC GROWTH ZONE WITH THE FRONT AND STRONG INSTABILITY
OVER AREAS W AND S OF KBIL. IN ADDITION...FAIRLY STRONG
850-700 MB FRONTOGENESIS WILL PROVIDE DECENT FORCING W AND SW OF
KBIL LATE THIS AFTERNOON THROUGH TONIGHT. MODELS WERE IN FAIRLY
GOOD AGREEMENT WITH THE QPF AMOUNTS WHICH WERE RATHER LOW...BUT
THE GFS HAD HIGHER BULLSEYES OF /.15/ INCHES OVER KLVM AND THE
FOOTHILLS. THE ADVISORIES W OF KBIL AND WARNINGS IN THE FOOTHILLS
WERE IN GOOD SHAPE...ALTHOUGH HAVE RAISED THE SNOW AMOUNTS WITH
BUFKIT SHOWING POSSIBLE SNOW RATIOS AS HIGH AS 25 TO 1. FORCING
DID NOT LOOK VERY COORDINATED FOR KBIL AND BIG HORN COUNTIES SO
LEFT THEM OUT OF THE ADVISORIES. KSHR HAD GOOD INSTABILITY AND WAS
ON THE EDGE OF THE FRONTOGENESIS...HOWEVER THE WIND DIRECTION WILL
BE NNW WHICH WAS DOWNSLOPE FOR THIS AREA...SO WILL KEEP THEM OUT
OF AN ADVISORY. ALSO LEFT THE NE BIG HORNS JUST UNDER ADVISORY
CRITERIA AS THEY HAD JUST A SHORT PERIOD OF LIFT AND LIMITED QPF.
FRONTOGENESIS BAND MOVES QUICKLY S OF THE AREA SAT MORNING AND THE
SHORTWAVE WILL ROTATE OUT OF THE AREA IN THE AFTERNOON. THE GOING
POPS...WHICH HAD THE SNOW TAPERING OFF DURING THE DAY...WERE IN
GOOD SHAPE.
A NW FLOW WILL OVERTAKE THE REGION SAT NIGHT THROUGH SUN NIGHT
WHEN THE NEXT SHORTWAVE APPROACHES THE AREA FROM THE NW. MOISTURE
FIELDS SUPPORTED THE LOW MOUNTAIN POPS IN THE FORECAST SAT NIGHT
AND SUN. RAISED POPS OVER THE NW ZONES SUN NIGHT AS THE SHORTWAVE
PUSHES THE NEXT FRONT INTO THE AREA. MODELS ALL HAD QPF DEVELOPING
IN THE NW BY 12Z MON. TEMPERATURES WILL BE BELOW SEASONAL VALUES
THROUGH THE PERIOD AND MADE SOME ADJUSTMENTS TO THEM BASED ON
LATEST GUIDANCE. ARTHUR
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
THE EXTENDED FORECAST PERIOD REMAINS COLD AND UNSETTLED. SEVERAL
CHANGES WERE MADE THROUGHOUT THE PERIOD...PRIMARILY TO TREND
TEMPERATURES DOWNWARD...BUT ALSO TO RAISE POPS FOR ARCTIC SYSTEM
MOVING ACROSS THE REGION EARLY NEXT WEEK.
ANOTHER SURGE OF ARCTIC AIR IS PROGGED INTO THE REGION TO START
THE EXTENDED PERIOD...BRINGING A CHANCE OF SNOW ACROSS THE AREA.
BEST POTENTIAL WILL BE IN THE WEST AND SOUTHWEST ZONES. THIS
SYSTEM REMAINS IN CONTROL ACROSS THE REGION THROUGH WEDNESDAY.
AN EXTENDED SNOW EVENT IS EXPECTED BEGINNING LATE SUNDAY AND
CONTINUING INTO TUESDAY NIGHT WITH THE ARCTIC PUSH. RAISES POPS
THROUGH THE PERIOD...WITH LIKELY POPS AROUND RED LODGE...AND
EXTENDED SLIGHT POTENTIAL EASTWARD. KEPT SNOW ACCUMULATIONS ON THE
LOW SIDE AT THIS TIME...BUT POTENTIAL IN FOOTHILLS COULD BE A BIT
HIGHER MONDAY MORNING AND EARLY AFTERNOON. DEEP UPSLOPE
FLOW...RESPECTABLE DENDRITIC GROWTH ZONE...DEEP MOISTURE
LAYER...AND STRONG FRONTOGENESIS COMBINE AHEAD OF COLDEST AIR TO
BRING IMPROVED POTENTIAL TO THE BEARTOOTH FOOTHILLS INCLUDING RED
LODGE...SO TOTALS COULD CLIMB QUICKLY FOR THIS PERIOD. OVERALL
UNCERTAINTY IN THE MODELS INCREASES SIGNIFICANTLY AFTER
WEDNESDAY...SO HAVE CONTINUED WITH INHERITED POPS FOR THURSDAY AND
FRIDAY.
COLD AIR WILL REMAIN IN PLACE THROUGH THE EXTENDED PERIOD...WITH
850MB TEMPS BELOW -20C FOR TUESDAY THROUGH THURSDAY. HAVE TRENDED
TEMPERATURES DOWNWARD ACROSS THE REGION THROUGH THE PERIOD...WITH
HIGHS BELOW ZERO EXPECT FOR WEDNESDAY. TEMPS WILL BEGIN TO RECOVER
THURSDAY...BUT SHOULD REMAIN BELOW AVERAGE...AS AM NOT SEEING
ANYTHING TO DRIVE A SIGNIFICANT WARM UP AT THIS TIME. AAG
&&
.AVIATION...
A QUICK MOVING DISTURBANCE WILL BRING SNOW TO THE WESTERN TWO-
THIRDS OF THE REGION TONIGHT. SNOW MAY BE HEAVY AT
TIMES...ESPECIALLY FROM KBIL WEST. EXPECT WIDESPREAD IFR
CONDITIONS ACROSS WESTERN AND CENTRAL ROUTES THROUGH LATE TONIGHT
IN THE SNOW. KLVM WILL SEE CONDITIONS DROP BELOW AIRPORT MINIMUMS
AT TIMES OVER THE NEXT SEVERAL HOURS...WHILE CONDITIONS AT KBIL
MAY APPROACH AIRPORT MINIMUMS AT TIMES. AREAS OF MVFR IN LOW
CLOUDS AND PERHAPS A BRIEF SNOW SHOWER ARE POSSIBLE ACROSS EASTERN
ROUTES OVERNIGHT...INCLUDING NEAR KMLS. MOUNTAINS WILL BE OBSCURED
OVERNIGHT. CONDITIONS WILL IMPROVE RAPIDLY SATURDAY MORNING FROM
NORTHWEST TO SOUTHEAST WITH VFR BY MID DAY ALL AREAS. STC
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 007/018 007/023 006/013 903/000 910/902 910/007 902/012
+3/S 00/B 14/S 43/S 21/I 10/B 11/B
LVM 001/018 004/025 002/014 908/903 916/905 911/007 904/015
+3/S 01/B 14/S 43/S 22/J 11/B 22/S
HDN 008/017 003/022 006/014 903/001 908/902 910/008 902/013
82/S 10/B 03/S 33/S 21/I 10/B 11/B
MLS 001/013 000/020 000/011 907/901 913/901 911/009 904/010
10/B 00/B 02/S 22/S 11/I 10/U 11/B
4BQ 004/014 000/021 004/014 904/002 911/901 910/009 901/015
21/B 10/U 02/S 23/S 21/I 10/B 11/B
BHK 000/007 904/019 903/007 910/902 915/903 913/006 906/010
10/B 00/B 01/E 12/S 11/I 11/B 12/S
SHR 007/014 901/022 901/014 905/001 911/903 913/008 906/014
84/S 10/U 03/S 43/S 32/J 10/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL NOON MST SATURDAY FOR
ZONES 34-35-38>41-64-65.
WINTER STORM WARNING IN EFFECT UNTIL NOON MST SATURDAY FOR
ZONES 56-66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
916 PM MST FRI JAN 31 2014
.UPDATE...
UPDATED FORECAST EARLIER TO INCLUDE BILLINGS IN THE WINTER
WEATHER ADVISORY. RUC MODEL WAS CONSISTENTLY GENERATING .20 PRECIP
LIQUID AMOUNTS WHICH WITH CONSERVATIVE 15 TO 1 SNOW RATIOS WAS
GOING TO YIELD 3 INCHES AND SNOW RATIOS COULD BE HIGHER FOR THE
BILLINGS AREA. ELSEWHERE WEB CAMS AT BIG TIMBER AND RED LODGE SHOW
SNOW IS ACCUMULATING STEADILY SO THE ADVISORIES AND WARNINGS LOOK
GOOD. NO FURTHER UPDATES. BORSUM
&&
.SHORT TERM...VALID FOR SAT AND SUN...
PRESSURE RISES WERE NOSING INTO THE NW PORTION OF THE FORECAST
AREA THIS AFTERNOON HERALDING THE ARRIVAL OF THE NEXT COLD FRONT.
RADAR WAS STARTING TO FILL IN BEHIND THE FRONT ACROSS N MT WHILE
SPOTTY ECHOES WERE DEVELOPING OVER THE FORECAST AREA. A N-S
ORIENTED JET WILL WEAKEN AS IT DIVES S INTO THE REGION AND PUSHES
A SHORTWAVE AND THE COLD FRONT INTO THE AREA. THE SHORTWAVE WILL
HAVE SOME Q-VECTOR CONVERGENCE WITH IT TONIGHT INTO SAT MORNING.
TIME-HEIGHT CROSS SECTIONS AND BUFKIT BOTH SHOWED A SHALLOW LOW-
LEVEL DENDRITIC GROWTH ZONE WITH THE FRONT AND STRONG INSTABILITY
OVER AREAS W AND S OF KBIL. IN ADDITION...FAIRLY STRONG
850-700 MB FRONTOGENESIS WILL PROVIDE DECENT FORCING W AND SW OF
KBIL LATE THIS AFTERNOON THROUGH TONIGHT. MODELS WERE IN FAIRLY
GOOD AGREEMENT WITH THE QPF AMOUNTS WHICH WERE RATHER LOW...BUT
THE GFS HAD HIGHER BULLSEYES OF /.15/ INCHES OVER KLVM AND THE
FOOTHILLS. THE ADVISORIES W OF KBIL AND WARNINGS IN THE FOOTHILLS
WERE IN GOOD SHAPE...ALTHOUGH HAVE RAISED THE SNOW AMOUNTS WITH
BUFKIT SHOWING POSSIBLE SNOW RATIOS AS HIGH AS 25 TO 1. FORCING
DID NOT LOOK VERY COORDINATED FOR KBIL AND BIG HORN COUNTIES SO
LEFT THEM OUT OF THE ADVISORIES. KSHR HAD GOOD INSTABILITY AND WAS
ON THE EDGE OF THE FRONTOGENESIS...HOWEVER THE WIND DIRECTION WILL
BE NNW WHICH WAS DOWNSLOPE FOR THIS AREA...SO WILL KEEP THEM OUT
OF AN ADVISORY. ALSO LEFT THE NE BIG HORNS JUST UNDER ADVISORY
CRITERIA AS THEY HAD JUST A SHORT PERIOD OF LIFT AND LIMITED QPF.
FRONTOGENESIS BAND MOVES QUICKLY S OF THE AREA SAT MORNING AND THE
SHORTWAVE WILL ROTATE OUT OF THE AREA IN THE AFTERNOON. THE GOING
POPS...WHICH HAD THE SNOW TAPERING OFF DURING THE DAY...WERE IN
GOOD SHAPE.
A NW FLOW WILL OVERTAKE THE REGION SAT NIGHT THROUGH SUN NIGHT
WHEN THE NEXT SHORTWAVE APPROACHES THE AREA FROM THE NW. MOISTURE
FIELDS SUPPORTED THE LOW MOUNTAIN POPS IN THE FORECAST SAT NIGHT
AND SUN. RAISED POPS OVER THE NW ZONES SUN NIGHT AS THE SHORTWAVE
PUSHES THE NEXT FRONT INTO THE AREA. MODELS ALL HAD QPF DEVELOPING
IN THE NW BY 12Z MON. TEMPERATURES WILL BE BELOW SEASONAL VALUES
THROUGH THE PERIOD AND MADE SOME ADJUSTMENTS TO THEM BASED ON
LATEST GUIDANCE. ARTHUR
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
THE EXTENDED FORECAST PERIOD REMAINS COLD AND UNSETTLED. SEVERAL
CHANGES WERE MADE THROUGHOUT THE PERIOD...PRIMARILY TO TREND
TEMPERATURES DOWNWARD...BUT ALSO TO RAISE POPS FOR ARCTIC SYSTEM
MOVING ACROSS THE REGION EARLY NEXT WEEK.
ANOTHER SURGE OF ARCTIC AIR IS PROGGED INTO THE REGION TO START
THE EXTENDED PERIOD...BRINGING A CHANCE OF SNOW ACROSS THE AREA.
BEST POTENTIAL WILL BE IN THE WEST AND SOUTHWEST ZONES. THIS
SYSTEM REMAINS IN CONTROL ACROSS THE REGION THROUGH WEDNESDAY.
AN EXTENDED SNOW EVENT IS EXPECTED BEGINNING LATE SUNDAY AND
CONTINUING INTO TUESDAY NIGHT WITH THE ARCTIC PUSH. RAISES POPS
THROUGH THE PERIOD...WITH LIKELY POPS AROUND RED LODGE...AND
EXTENDED SLIGHT POTENTIAL EASTWARD. KEPT SNOW ACCUMULATIONS ON THE
LOW SIDE AT THIS TIME...BUT POTENTIAL IN FOOTHILLS COULD BE A BIT
HIGHER MONDAY MORNING AND EARLY AFTERNOON. DEEP UPSLOPE
FLOW...RESPECTABLE DENDRITIC GROWTH ZONE...DEEP MOISTURE
LAYER...AND STRONG FRONTOGENESIS COMBINE AHEAD OF COLDEST AIR TO
BRING IMPROVED POTENTIAL TO THE BEARTOOTH FOOTHILLS INCLUDING RED
LODGE...SO TOTALS COULD CLIMB QUICKLY FOR THIS PERIOD. OVERALL
UNCERTAINTY IN THE MODELS INCREASES SIGNIFICANTLY AFTER
WEDNESDAY...SO HAVE CONTINUED WITH INHERITED POPS FOR THURSDAY AND
FRIDAY.
COLD AIR WILL REMAIN IN PLACE THROUGH THE EXTENDED PERIOD...WITH
850MB TEMPS BELOW -20C FOR TUESDAY THROUGH THURSDAY. HAVE TRENDED
TEMPERATURES DOWNWARD ACROSS THE REGION THROUGH THE PERIOD...WITH
HIGHS BELOW ZERO EXPECT FOR WEDNESDAY. TEMPS WILL BEGIN TO RECOVER
THURSDAY...BUT SHOULD REMAIN BELOW AVERAGE...AS AM NOT SEEING
ANYTHING TO DRIVE A SIGNIFICANT WARM UP AT THIS TIME. AAG
&&
.AVIATION...
A QUICK MOVING DISTURBANCE WILL BRING SNOW TO THE WESTERN TWO-
THIRDS OF THE REGION TONIGHT. SNOW MAY BE HEAVY AT
TIMES...ESPECIALLY FROM KBIL WEST. EXPECT WIDESPREAD IFR
CONDITIONS ACROSS WESTERN AND CENTRAL ROUTES THROUGH LATE TONIGHT
IN THE SNOW. KLVM WILL SEE CONDITIONS DROP BELOW AIRPORT MINIMUMS
AT TIMES OVER THE NEXT SEVERAL HOURS...WHILE CONDITIONS AT KBIL
MAY APPROACH AIRPORT MINIMUMS AT TIMES. AREAS OF MVFR IN LOW
CLOUDS AND PERHAPS A BRIEF SNOW SHOWER ARE POSSIBLE ACROSS EASTERN
ROUTES OVERNIGHT...INCLUDING NEAR KMLS. MOUNTAINS WILL BE OBSCURED
OVERNIGHT. CONDITIONS WILL IMPROVE RAPIDLY SATURDAY MORNING FROM
NORTHWEST TO SOUTHEAST WITH VFR BY MID DAY ALL AREAS. STC
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 007/018 007/023 006/013 903/000 910/902 910/007 902/012
93/S 00/B 14/S 43/S 21/I 10/B 11/B
LVM 001/018 004/025 002/014 908/903 916/905 911/007 904/015
+3/S 01/B 14/S 43/S 22/J 11/B 22/S
HDN 008/017 003/022 006/014 903/001 908/902 910/008 902/013
92/S 10/B 03/S 33/S 21/I 10/B 11/B
MLS 902/013 000/020 000/011 907/901 913/901 911/009 904/010
10/B 00/B 02/S 22/S 11/I 10/U 11/B
4BQ 004/014 000/021 004/014 904/002 911/901 910/009 901/015
21/B 10/U 02/S 23/S 21/I 10/B 11/B
BHK 905/007 904/019 903/007 910/902 915/903 913/006 906/010
10/B 00/B 01/E 12/S 11/I 11/B 12/S
SHR 007/014 901/022 901/014 905/001 911/903 913/008 906/014
83/S 10/U 03/S 43/S 32/J 10/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL NOON MST SATURDAY FOR
ZONES 34-35-39>41-64-65.
WINTER STORM WARNING IN EFFECT UNTIL NOON MST SATURDAY FOR
ZONES 56-66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...CORRECTED
NWS ELKO NV
303 AM PST SAT FEB 1 2014
.SYNOPSIS...LOOK FOR DRIER CONDITIONS TODAY AS AN UPPER LEVEL
SYSTEM MOVES EAST OF THE AREA. COLD TEMPERATURES WILL BE THE RULE
THROUGH THE SHORT TERM. EXPECT A RETURN TO LIGHT SNOW SHOWERS LATE
SUNDAY NIGHT AND MONDAY. LITTLE ACCUMULATIONS ARE EXPECTED IN THE
VALLEYS.
&&
.SHORT TERM...TODAY THROUGH MONDAY. SOME LOW CLOUDS ARE ROLLING
THROUGH THE NORTHERN AND CENTRAL PARTS OF NEVADA...PER LATEST
SATELLITE IMAGERY. THE LOW CLOUDS IN THE NORTH ARE PRODUCING VERY
LIGHT RETURNS ON RADAR AT THIS TIME. THERE IS A VORTICITY MAXIMUM
IN NORTHERN NEVADA SHOWN BY THE RUC13 THAT IS COINCIDENT WITH
THESE SHOWERS. THIS FEATURE IS EXPECTED TO MOVE SOUTH DURING THE
MORNING. NO ACCUMULATIONS ARE EXPECTED.
THE LAST VESTIGES OF THE UPPER LEVEL TROUGH WILL BE EXITING THE
AREA TODAY. THERE IS THE NOSE OF A WEAK 250 MB JET...WITH A WEAK VORT
MAX...AND ISOLATED TO SCATTERED SNOW SHOWERS IN NORTHEAST NEVADA
CANNOT BE RULED OUT. THEREFORE...HAVE KEPT POPS IN THE FORECAST
FOR THIS AREA. IT WILL BE VERY CHILLY OUT THERE WITH 700 MB
TEMPERATURES AROUND -12 TO -14C. THIS TRANSLATES INTO THE LOW TO
MID 30S THIS AFTERNOON.
NORTHERLY FLOW ALOFT WILL DEVELOP TONIGHT AS A WEAK UPPER LEVEL
RIDGE MOVES EAST. OVERNIGHT LOWS WILL BE A CHALLENGE WITH SNOW
COVER IN SOME AREAS. AS EVIDENCED THIS EVENING...ANY CLEARING
RESULTS IN TEMPERATURES BOTTOMING OUT.
ON SUNDAY...EXPECT A TROUGH TO APPROACH THE FORECAST AREA FROM THE
NORTHWEST. EXPECT AN INCREASE IN CLOUDS DURING THE DAY...AND AS A
RESULT...LITTLE TO NO WARMING EXPECTED WITH TEMPERATURES IN THE
LOW TO MID 30S ONCE AGAIN. NOT EXPECTING ANY PRECIPITATION DURING
THE DAY THOUGH.
SUNDAY NIGHT INTO MONDAY...THE TROUGH WILL PASS ACROSS THE STATE WITH
ENERGY PASSING ACROSS THE NORTH AND SOUTH. HAVE KEPT ISOLATED TO
SCATTERED SNOW SHOWERS IN THE FORECAST. MODEL CROSS SECTIONS AND
SOUNDINGS SHOW A LIMITED MOISTURE AND LIFT PROFILE AT THIS
TIME...AND SO ONLY EXPECTING LIMITED ACCUMULATIONS AT LESS THAN
ONE INCH IN THE VALLEYS.
.LONG TERM...MONDAY NIGHT THROUGH NEXT SATURDAY. MODELS ALL IN GOOD
AGREEMENT WITH OVERALL PATTERN...HOWEVER DIFFERENCES ON EVOLUTION OF
LOW PRESSURE SYSTEM THAT DEVELOPS TO NORTH BY THURSDAY.
MONDAY NIGHT THROUGH TUESDAY. SHORTWAVE WILL BE PUSHING THROUGH
NORTHERN NEVADA DURING THE PERIOD WITH SNOW SHOWERS LINGERING
THROUGH TUESDAY AFTERNOON AS COLD AIR ALOFT WILL KEEP THE ATMOSPHERE
UNSTABLE. EXPECT TEMPERATURES NEAR NORMAL FOR THE PERIOD.
TUESDAY NIGHT AND WEDNESDAY. A FEW LINGERING SHOW SHOWERS OVER THE
HIGHER TERRAIN WITH NORTHWESTERLY FLOW DOMINATING THE AREA.
THURSDAY AND FRIDAY. LOW PRESSURE WILL DEVELOP TO THE NORTH AND
RETROGRADE TO NEAR THE NORTHERN NEVADA BORDER...HOWEVER MODELS
DISAGREE ON HOW FAR SOUTH LOW WILL MOVE AND HOW DEEP IT BECOMES
BEFORE WESTERLIES KICK IT EASTWARD. A 700MB FRONTAL ZONE IS DEPICTED
TO DEVELOP SOMEWHERE ACROSS NORTHERN OR CENTRAL NEVADA AHEAD OF THE
LOW WITH SNOW DEVELOPING ALONG THIS FRONT...INCREASED POPS BUT
UNCERTAIN ON EXACT LOCATION OF THIS FRONTAL DEVELOPMENT. LOW WILL
MOVE EAST AT SOME POINT ON FRIDAY BUT TIMING VERY UNCERTAIN AT THIS
POINT.
FRIDAY NIGHT AND SATURDAY. ALL MODELS IN GOOD AGREEMENT WITH ZONAL
WESTERLY FLOW DEVELOPING ACROSS THE EASTERN PACIFIC AND WESTERN US.
THIS WILL BRING INCREASING CLOUDS AND WARMING TEMPS ALONG WITH
CHANCES OF PRECIPITATION.
&&
.AVIATION...VFR EXPECTED AT ALL SITES EXCEPT KELY WHERE PATCHY
FREEZING FOG HAS DEVELOPED WITH IFR CONDITIONS EXPECTED THROUGH THE
MORNING HOURS SHOULD BECOME VFR AFTER 16Z BUT OCCASIONAL MVFR CIGS
POSSIBLE IN THE AFTERNOON.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
86/90/90
AREA FORECAST DISCUSSION
NWS ELKO NV
302 AM PST SAT FEB 1 2014
.SYNOPSIS...LOOK FOR DIRER CONDITIONS TODAY AS AN UPPER LEVEL
SYSTEM MOVES EAST OF THE AREA. COLD TEMPERATURES WILL BE THE RULE
THROUGH THE SHORT TERM. EXPECT A RETURN TO LIGHT SNOW SHOWERS LATE
SUNDAY NIGHT AND MONDAY. LITTLE ACCUMULATIONS ARE EXPECTED IN THE
VALLEYS.
&&
.SHORT TERM...TODAY THROUGH MONDAY. SOME LOW CLOUDS ARE ROLLING
THROUGH THE NORTHERN AND CENTRAL PARTS OF NEVADA...PER LATEST
SATELLITE IMAGERY. THE LOW CLOUDS IN THE NORTH ARE PRODUCING VERY
LIGHT RETURNS ON RADAR AT THIS TIME. THERE IS A VORTICITY MAXIMUM
IN NORTHERN NEVADA SHOWN BY THE RUC13 THAT IS COINCIDENT WITH
THESE SHOWERS. THIS FEATURE IS EXPECTED TO MOVE SOUTH DURING THE
MORNING. NO ACCUMULATIONS ARE EXPECTED.
THE LAST VESTIGES OF THE UPPER LEVEL TROUGH WILL BE EXITING THE
AREA TODAY. THERE IS THE NOSE OF A WEAK 250 MB JET...WITH A WEAK VORT
MAX...AND ISOLATED TO SCATTERED SNOW SHOWERS IN NORTHEAST NEVADA
CANNOT BE RULED OUT. THEREFORE...HAVE KEPT POPS IN THE FORECAST
FOR THIS AREA. IT WILL BE VERY CHILLY OUT THERE WITH 700 MB
TEMPERATURES AROUND -12 TO -14C. THIS TRANSLATES INTO THE LOW TO
MID 30S THIS AFTERNOON.
NORTHERLY FLOW ALOFT WILL DEVELOP TONIGHT AS A WEAK UPPER LEVEL
RIDGE MOVES EAST. OVERNIGHT LOWS WILL BE A CHALLENGE WITH SNOW
COVER IN SOME AREAS. AS EVIDENCED THIS EVENING...ANY CLEARING
RESULTS IN TEMPERATURES BOTTOMING OUT.
ON SUNDAY...EXPECT A TROUGH TO APPROACH THE FORECAST AREA FROM THE
NORTHWEST. EXPECT AN INCREASE IN CLOUDS DURING THE DAY...AND AS A
RESULT...LITTLE TO NO WARMING EXPECTED WITH TEMPERATURES IN THE
LOW TO MID 30S ONCE AGAIN. NOT EXPECTING ANY PRECIPITATION DURING
THE DAY THOUGH.
SUNDAY NIGHT INTO MONDAY...THE TROUGH WILL PASS ACROSS THE STATE WITH
ENERGY PASSING ACROSS THE NORTH AND SOUTH. HAVE KEPT ISOLATED TO
SCATTERED SNOW SHOWERS IN THE FORECAST. MODEL CROSS SECTIONS AND
SOUNDINGS SHOW A LIMITED MOISTURE AND LIFT PROFILE AT THIS
TIME...AND SO ONLY EXPECTING LIMITED ACCUMULATIONS AT LESS THAN
ONE INCH IN THE VALLEYS.
.LONG TERM...MONDAY NIGHT THROUGH NEXT SATURDAY. MODELS ALL IN GOOD
AGREEMENT WITH OVERALL PATTERN...HOWEVER DIFFERENCES ON EVOLUTION OF
LOW PRESSURE SYSTEM THAT DEVELOPS TO NORTH BY THURSDAY.
MONDAY NIGHT THROUGH TUESDAY. SHORTWAVE WILL BE PUSHING THROUGH
NORTHERN NEVADA DURING THE PERIOD WITH SNOW SHOWERS LINGERING
THROUGH TUESDAY AFTERNOON AS COLD AIR ALOFT WILL KEEP THE ATMOSPHERE
UNSTABLE. EXPECT TEMPERATURES NEAR NORMAL FOR THE PERIOD.
TUESDAY NIGHT AND WEDNESDAY. A FEW LINGERING SHOW SHOWERS OVER THE
HIGHER TERRAIN WITH NORTHWESTERLY FLOW DOMINATING THE AREA.
THURSDAY AND FRIDAY. LOW PRESSURE WILL DEVELOP TO THE NORTH AND
RETROGRADE TO NEAR THE NORTHERN NEVADA BORDER...HOWEVER MODELS
DISAGREE ON HOW FAR SOUTH LOW WILL MOVE AND HOW DEEP IT BECOMES
BEFORE WESTERLIES KICK IT EASTWARD. A 700MB FRONTAL ZONE IS DEPICTED
TO DEVELOP SOMEWHERE ACROSS NORTHERN OR CENTRAL NEVADA AHEAD OF THE
LOW WITH SNOW DEVELOPING ALONG THIS FRONT...INCREASED POPS BUT
UNCERTAIN ON EXACT LOCATION OF THIS FRONTAL DEVELOPMENT. LOW WILL
MOVE EAST AT SOME POINT ON FRIDAY BUT TIMING VERY UNCERTAIN AT THIS
POINT.
FRIDAY NIGHT AND SATURDAY. ALL MODELS IN GOOD AGREEMENT WITH ZONAL
WESTERLY FLOW DEVELOPING ACROSS THE EASTERN PACIFIC AND WESTERN US.
THIS WILL BRING INCREASING CLOUDS AND WARMING TEMPS ALONG WITH
CHANCES OF PRECIPITATION.
&&
.AVIATION...VFR EXPECTED AT ALL SITES EXCEPT KELY WHERE PATCHY
FREEZING FOG HAS DEVELOPED WITH IFR CONDITIONS EXPECTED THROUGH THE
MORNING HOURS SHOULD BECOME VFR AFTER 16Z BUT OCCASIONAL MVFR CIGS
POSSIBLE IN THE AFTERNOON.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
86/90/90
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
307 PM EST SAT FEB 1 2014
.SYNOPSIS...
LOW PRESSURE WILL PASS THROUGH THE SAINT LAWRENCE VALLEY TONIGHT
INTO SUNDAY MORNING BRINGING WIDESPREAD LIGHT SNOW AND MIXED
PRECIPITATION TO THE AREA ALONG WITH MILD MID-WINTER TEMPERATURES.
A RETURN OF SEASONABLY COOL AND DRY WEATHER IS THEN EXPECTED BY
MONDAY INTO TUESDAY BEFORE ADDITIONAL WINTRY PRECIPITATION LIKELY
RETURNS BY THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 307 PM EST SATURDAY...LATEST 12Z MODEL SUITE INCLUDING 18Z
RAP PROGS STILL IN GOOD AGREEMENT SHOWING A WIDESPREAD LIGHT TO
MODERATE WINTER PCPN EVENT AFFECTING OUR AREA TONIGHT INTO SUNDAY
MORNING AS LOW PRESSURE TRACKS THROUGH THE SLV. FAIRLY ROBUST WARM
THERMAL ADVECTION ON THE NOSE OF 50-60KT SOUTHWESTERLY 850 JET
ALONG WITH INCREASINGLY MOIST LOWER TO MID LEVELS SHOULD BE MORE
THAN SUFFICIENT TO PRODUCE WIDESPREAD PCPN ON THE ORDER OF A
QUARTER TO A HALF AN INCH ACROSS THE SLV/NRN DACKS AND NRN GREENS.
LESSER AMTS ELSEWHERE (0.25 OR LESS)CHAMPLAIN/CT RVR VALLEYS AND
MUCH OF SOUTH CENTRAL VT WHICH WILL BE AFFECTED TO A CONSIDERABLE
DEGREE BY DOWNSLOPING EFFECTS. PCPN MAY ALSO MIX WITH PERIODS OF
SLEET OR EVEN RAIN AT TIMES...NAMELY AT PCPN ONSET THROUGH EARLY
THIS EVENING WHEN NEAR-SFC TEMPS ARE THE MILDEST...AND AGAIN
OVERNIGHT WHEN MID-LEVEL WARM NOSE REACHES MOST NORTHWARD EXENT.
NONETHELESS...FEEL WITH SUCH DRY TD VALUES WET BULB PROCESSES WILL
TEND TO DOMINATE OVER TIME AND MOST OF THE PCPN...ESP IN THE ADVSY
AREA WILL FALL IN THE FORM OF SNOW. LOOKING AT AMOUNTS GENERALLY
IN THE 2-5/3-6 INCH RANGE IN THESE AREAS BY MORNING WITH ISOLATED
AMOUNTS TO PERHAPS 7/8 INCHES IN FAVORED HIGHER ELEV SPOTS.
ELSEWHERE...A GENERAL DUSTING TO 2 INCHES LOOKS REASONABLE WITH
LOWEST AMOUNTS FAR SOUTHERN VT WHICH WILL BE FURTHER REMOVED FROM
BEST WAA/DYNAMICS/MOISTURE. ADDITIONALLY AFOREMENTIONED SHADOWING
EFFECTS WILL LIKELY PRODUCE A LOCAL MINIMUM IN THE IMMEDIATE
KPBG/KBTV VCNTY...ESP AFTER INITIAL WARM ADVECTION PCPN BURST THIS
EVENING WHEN CORE OF SOUTHWESTERLY 850 JET MOVES INTO THE AREA.
LOWS TONIGHT MAINLY FROM THE UPPER 20S TO LOWER 30S UNDER
CONTINUED SOUTH/SOUTHWESTERLY FLOW.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 307 PM EST SATURDAY...BY TOMORROW MORNING...SFC LOW WILL BE
QUICKLY EXITING OFF TO OUR NORTHEAST INTO EASTERN CANADA WITH ANY
LINGERING LIGHT SNOWS AND/OR MIXED PCPN GENERALLY ENDING BY NOON.
ANY BACK END ACCUMULATIONS SHOULD BE LIGHT. THE SYSTEM`S SFC COLD
FRONT WILL BE IN THE PROCESS OF SWINGING THROUGH THE AREA...AND
BEHIND THIS BOUNDARY WINDS WILL TREND WEST TO NORTHWESTERLY BY
DAYS END. WITH SFC FRONTAL PASSAGE IN THE LATE MORNING THROUGH
MID-AFTERNOON HOURS...A NEAR NORMAL DIURNAL TEMPERATURE TREND IS
EXPECTED AS DAYTIME MAXES TOP OUT IN THE 35 TO 40 DEGREE RANGE FOR
MOST SPOTS.
THEREAFTER SENSIBLE WEATHER TRENDS QUIET AND SEASONABLE AS BROAD SFC
HIGH PRESSURE BUILDS INTO THE REGION BRIDGED ALOFT BY WESTERLY
ZONAL FLOW. THUS PRIOR IDEA OF CLEAR TO PTLY CLOUDY SKIES ALONG
WITH DRY AND COOLER WEATHER STILL LOOKS RIGHT ON TRACK. LOWS SUNDAY
NIGHT GENERALLY 10 TO 20 ABOVE...WITH HIGHS ON MONDAY 23 TO 30. DID
OPT TO TREND ON THE COLDER SIDE OF NUMERICAL GUIDANCE ON MIN TEMPS
MONDAY NIGHT WHEN CENTER OF 1030+ MB SFC HIGH BUILDS DIRECTLY ATOP
THE FORECAST AREA ALONG WITH IDEAL RADIATIVE EFFECTS. THIS WOULD
SUGGEST READINGS BOTTOMING OUT FROM 5 BELOW TO 5 ABOVE WITH
LOCALIZED COLDER SPOTS.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 305 PM EST SATURDAY...THE LONG TERM FCST FOCUS IS WEDS INTO
THURS TIME PERIOD ASSOCIATED WITH POTENTIAL WINTER STORM. THE
LATEST 12Z NWP GUIDANCE AND BOTH 00Z AND 12Z ENSEMBLE DATA IN VERY
GOOD AGREEMENT...RESULTING IN ABOVE NORMAL CONFIDENCE FOR UPCOMING
SYSTEM. THE LATEST TRENDS DO SUPPORT A SLIGHTLY MORE SOUTHERN
TRACK...WHICH PLACES OUR CWA WELL ESTABLISHED IN THE COLD SECTOR
ALONG WITH LESS QPF/SNOWFALL.
LARGE SCALE SYNOPTIC SETUP SHOWS DIGGING MID/UPPER LVL TROF ACRS
THE INTER MOUNTAIN WEST WITH POTENT 5H VORT EJECTING INTO THE
CENTRAL PLAINS BY 12Z TUES. THIS WL HELP IN THE DEVELOPMENT OF SFC
LOW PRES ACRS THE MS VALLEY...WHILE A FAST CONFLUENT FLW ALOFT
CONTS ACRS THE EASTERN CONUS. SFC LOW PRES WL TRACK TWD THE OHIO
VALLEY BY 06Z WEDS...THEN NEAR PITTSBURGH PA BY 12Z WEDS AND NYC
BY WEDS EVENING. THIS SYSTEM WL HAVE PLENTY OF DEEP SUB-TROPICAL
MOISTURE TO WORK WITH AND A FAVORABLE DUAL JET STRUCTURE. LATEST
GUIDANCE SUPPORTS ABOVE NORMAL PWS BTWN 0.75" AND 1.25" ACRS THE
MID ATLANTIC STATES...WITH A SHARP NORTH TO SOUTH GRADIENT ACRS
OUR CWA. IN ADDITION...FAST MOVEMENT OF SYSTEM AND NO CLOSED 5H/7H
CIRCULATIONS WL PREVENT STORM FROM BEING A BLOCKBUSTER AND MORE OF
A MODERATE PREICP/SNOWFALL EVENT FOR WEDS INTO THURS. THE SHARP
THERMAL PACKING ACRS OUR CWA...INDICATES STRONG LOW TO MID LVL FGEN/WAA
FORCING ASSOCIATED WITH NOSE OF 40 TO 50 KNOT 85H JET AND RRQ OF
25H JET ACRS SOUTHERN CANADA. RESULTING IN A PERIOD OF DEEP LAYER
LIFT/MOISTURE...WITH GREATEST IMPACTS ACRS OUR CENTRAL/SOUTHERN CWA. VERY
EARLY INDICATIONS SUPPORT QPF RANGING FROM 0.25 INTERNATIONAL
BORDER TO 0.75" RUTLAND/WINDSOR COUNTIES...RESULTING IN ADVISORY
TYPE EVENT NEAR THE BORDER AND WARNINGS ACRS CENTRAL/SOUTHERN VT
ZNS. ANY SHIFT FURTHER NORTH OR SOUTH WOULD GREATLY IMPACT THE
AMOUNT OF QPF/SNOWFALL EXPECTED AND LLVL THERMAL PROFILES. WL CONT
TO MENTION CAT POPS FOR WEDS WITH THERMAL SOUNDINGS SUPPORTING ALL
SNOW FOR OUR ENTIRE CWA. SNOW WL TAPER OFF WEDS NIGHT INTO
THURSDAY WITH A BRIEF PERIOD OF UPSLOPE SNOW SHOWERS
POSSIBLE...BUT DRIER AIR ASSOCIATED WITH SFC HIGH PRES BUILDS INTO
OUR REGION. EXPECT NEAR NORMAL TEMPS FOR THE PERIOD WITH DAILY
HIGHS IN THE 20S AND LOWS IN THE SINGLE DIGITS/TEENS...EXCEPT BLW
NORMAL READINGS ON THURS/FRIDAY ASSOCIATED WITH LLVL CAA BEHIND
DEPARTING SFC LOW PRES. ANOTHER SYSTEM MAY IMPACT OUR REGION NEXT
WEEKEND AS ACTIVE STORM PATTERN DEVELOPS WITH POTENTIAL SYSTEMS
EVERY COUPLE OF DAYS.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
THROUGH 18Z SUNDAY...AVIATION FOCUS WL BE TIMING OF SNOW THIS
AFTN/EVENING AND ASSOCIATED IFR/LIFR CONDITIONS. CRNT RADAR SHOWS
LIGHT SNOW WITH BANDS OF MODERATE SNOW QUICKLY MOVING FROM SW TO
NE TWD CENTRAL/NORTHERN NY THIS AFTN. LEADING EDGE OF PRECIP IS
FALLING AS VIRGA IS LLVLS ARE VERY DRY WITH SFC TEMP/DWPT SPREADS
OF 10 TO 15 DEGREES ACRS OUR REGION. USING THE TIME OF ARRIVAL
TOOL AND LATEST RAP 13 DATA...THINKING SNOW DEVELOPS AT MSS/SLK BTWN
18Z-19Z WITH IFR CONDITIONS BY 20Z. FOR PBG/BTV THINKING SNOW
DEVELOPS BY 21Z WITH IFR CONDITIONS FOR VIS BTWN 1-2SM DEVELOPING
BY 22Z TONIGHT. A PERIOD OF LIFR CONDITIONS ARE LIKELY WITH VIS
<1/2SM AND CIGS AROUND 1000 FEET FOR SLK/MSS BTWN 22Z-03Z THIS
EVENING. OTHERWISE...EXPECT IFR CONDITIONS AT MPV BY 23Z AND
MAINLY MVFR CONDITIONS PREVAILING AT RUT AS BEST MOISTURE/LIFT IS
NORTH OF THIS TAF SITE. THE HEAVIER AND STEADIER PRECIP WL EXIT
OUR TAF SITES BY 06Z WITH EXCEPTION OF SLK/MSS...WHICH WL CONT TO
SEE PERIODS OF -SN WITH IFR CONDITIONS PREVAILING. THINKING BL
TEMPS WARM ENOUGH AT PBG/BTV FOR A MIXTURE OF -RASN BY 06Z WITH
VIS BTWN 3-5SM...ESPECIALLY AS BETTER LIFTS SHIFTS NORTH OF
REGION. A DEVELOPING SW JET OF 45 TO 55 KNOTS BTWN 2500 AND 3500
FT AGL WL PRODUCE AREAS OF TURBULENCE...ESPECIALLY IN THE
MTNS...WITH SOME SFC WIND GUSTS TO 20 KNOTS POSSIBLE. SOME LLVL WS
WL BE POSSIBLE AT MSS WITH NE SFC FLW OF 10 KNTS...WHILE FLW ALOFT
IS FROM THE SW.
OUTLOOK 18Z SUNDAY THROUGH WEDNESDAY...COLD FRNT SWEEPS ACRS OUR
CWA BTWN 15Z-21Z SUNDAY WITH ANOTHER BRIEF PERIOD OF PRECIP
POSSIBLE WITH MVFR/IFR CONDITIONS AND A WIND SHIFT TO THE W/NW.
SFC HIGH PRES WITH VFR CONDITIONS WL PREVAIL FROM 00Z MONDAY THRU
06Z WEDS. NEXT SYSTEM WITH WIDESPREAD SNOW AND IFR CONDITIONS WL
IMPACT OUR TAF SITES BY 12Z WEDS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL 11 AM EST SUNDAY FOR VTZ002>004-
006-007-016.
NY...WINTER WEATHER ADVISORY UNTIL 11 AM EST SUNDAY FOR NYZ026>031-
034-087.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...TABER
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
305 PM EST SAT FEB 1 2014
.SYNOPSIS...
LOW PRESSURE ALONG A FRONTAL BOUNDARY WILL BRING A MIX OF
PRECIPITATION TO THE NORTH COUNTRY...STARTING THIS AFTERNOON...THEN
TAPER OFF ON SUNDAY. HIGH PRESSURE BUILDS OVER THE AREA SUNDAY NIGHT
INTO NEXT TUESDAY NIGHT...FOLLOWED BY ANOTHER STORM SYSTEM MIDWEEK
WITH HIGH PRESSURE RETURNING GOING INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1203 PM EST SATURDAY...MINOR ADJUSTMENT TO UPGRADE SOUTHWEST
ST LAWRENCE COUNTY IN THE EXISTING WINTER WX ADVSY THIS
AFTERNOON/TONIGHT. LATEST 12Z MODEL SUITE INCLUDING THE 15Z RAP
ANALYSIS STILL IN GOOD AGREEMENT SHOWING A WIDESPREAD LIGHT TO
MODERATE WINTER PCPN EVENT AFFECTING OUR AREA LATER TODAY TONIGHT
AS LOW PRESSURE TRACKS THROUGH THE SLV. FAIRLY ROBUST WARM THERMAL
ADVECTION ON THE NOSE OF 50-60KT 850 JET ALONG WITH INCREASINGLY
DEEP MOISTURE SHOULD BE MORE THAN SUFFICIENT TO PRODUCE WIDESPREAD
PCPN ON THE ORDER OF A QUARTER TO A HALF AN INCH ACROSS THE
SLV/NRN DACKS AND NRN GREENS. LESSER AMTS ELSEWHERE (0.25 OR LESS)
CHAMPLAIN/CT RVR VALLEYS AND MUCH OF SOUTH CENTRAL VT WHICH WILL
BE AFFECTED TO A CONSIDERABLE DEGREE BY DOWNSLOPING EFFECTS. PCPN
MAY ALSO MIX WITH PERIODS OF SLEET OR EVEN RAIN AT TIMES...NAMELY
AT PCPN ONSET WHEN NEAR-SFC TEMPS ARE THE MILDEST...AND AGAIN
OVERNIGHT WHEN MID-LEVEL WARM NOSE REACHES MOST NORTHWARD EXENT.
NONETHELESS...FEEL WITH SUCH DRY TD VALUES WET BULB PROCESSES WILL
TEND TO DOMINATE AND MOST OF THE PCPN...ESP IN THE ADVSY AREA WILL
FALL IN THE FORM OF SNOW. LOOKING AT AMOUNTS GENERALLY IN THE
2-5/3-6 INCH RANGE IN THE ADVSY AREA BY MORNING WITH ISOLATED
AMOUNTS TO PERHAPS 7/8 INCHES IN FAVORED HIGHER ELEV SPOTS.
ELSEWHERE...A GENERAL DUSTING TO 2 INCHES LOOKS REASONABLE WITH
LOWEST AMOUNTS FAR SOUTHERN VT WHICH WILL BE FURTHER REMOVED FROM
BEST WAA/DYNAMICS. AFOREMENTIONED SHADOWING EFFECTS MAY ALSO
PRODUCE A LOCAL MINIMUM IN THE IMMEDIATE KPBG/KBTV VCNTY...ESP
AFTER INITIAL WARM ADVECTION PCPN BURST WHEN CORE OF SOUTHWESTERLY
850 JET MOVES INTO THE AREA. HIGHS TODAY GENERALLY LOWER TO MID
30S...THEN MID TO UPPER 20S TONIGHT UNDER CONTINUED
SOUTH/SOUTHWESTERLY FLOW.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 410 AM EST SATURDAY...GOING INTO SUNDAY...FRONTAL BOUNDARY
CONTINUES PUSH THRU THE AREA WITH ANY REMAINING PRECIP GOING OVER
TO ALL -SW AS COLDER AIR BEGINS TO FILTER INTO AREA. EXPECTING
EARLY HIGHS FOR THE CWA AS TEMPS SLOWLY DROP THRU THE MORNING HRS.
ADDITIONAL INCH OR SO IS POSSIBLE IN AREAS WHERE ADVISORY IS UP
WITH LESSER AMTS SOUTH. BY SUNDAY AFTNOON...FRONTAL BOUNDARY HAS
CLRD THE CWA...LEAVING AREA UNDER WNW FLOW. EXPECTING SOME
LINGERING -SW DUE TO UPSLOPE/OROGRAPHIC EFFECTS W/ ADDITIONAL
LIGHT ACCUM...MAINLY OVER HIGHER TRRN. GOING INTO SUN EVENING/NGT...
PRECIP WILL HAVE TAPERED OFF AND GIVE WAY TO STRONG SFC RIDGE
BUILDING EAST FROM THE GREAT LKS REGION. GENERAL CLRING TREND WILL
ENSUE AND CONTINUE THRU THE MONDAY TIME FRAME PROVIDING AREA A NICE
DAY. OVERALL FOR TEMPS...NEAR NORMAL WITH HIGHS IN THE 20S MONDAY
AND LOWS IN THE TEEN TO SINGLE NUMBERS UNDER CLRING SKIES SUN
NGT. SUNDAY WILL SEE HIGHS IN THE LOW 30S EAST AND 20S WEST.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 305 PM EST SATURDAY...THE LONG TERM FCST FOCUS IS WEDS INTO
THURS TIME PERIOD ASSOCIATED WITH POTENTIAL WINTER STORM. THE
LATEST 12Z NWP GUIDANCE AND BOTH 00Z AND 12Z ENSEMBLE DATA IN VERY
GOOD AGREEMENT...RESULTING IN ABOVE NORMAL CONFIDENCE FOR UPCOMING
SYSTEM. THE LATEST TRENDS DO SUPPORT A SLIGHTLY MORE SOUTHERN
TRACK...WHICH PLACES OUR CWA WELL ESTABLISHED IN THE COLD SECTOR
ALONG WITH LESS QPF/SNOWFALL.
LARGE SCALE SYNOPTIC SETUP SHOWS DIGGING MID/UPPER LVL TROF ACRS
THE INTER MOUNTAIN WEST WITH POTENT 5H VORT EJECTING INTO THE
CENTRAL PLAINS BY 12Z TUES. THIS WL HELP IN THE DEVELOPMENT OF SFC
LOW PRES ACRS THE MS VALLEY...WHILE A FAST CONFLUENT FLW ALOFT
CONTS ACRS THE EASTERN CONUS. SFC LOW PRES WL TRACK TWD THE OHIO
VALLEY BY 06Z WEDS...THEN NEAR PITTSBURGH PA BY 12Z WEDS AND NYC
BY WEDS EVENING. THIS SYSTEM WL HAVE PLENTY OF DEEP SUB-TROPICAL
MOISTURE TO WORK WITH AND A FAVORABLE DUAL JET STRUCTURE. LATEST
GUIDANCE SUPPORTS ABOVE NORMAL PWS BTWN 0.75" AND 1.25" ACRS THE
MID ATLANTIC STATES...WITH A SHARP NORTH TO SOUTH GRADIENT ACRS
OUR CWA. IN ADDITION...FAST MOVEMENT OF SYSTEM AND NO CLOSED 5H/7H
CIRCULATIONS WL PREVENT STORM FROM BEING A BLOCKBUSTER AND MORE OF
A MODERATE PREICP/SNOWFALL EVENT FOR WEDS INTO THURS. THE SHARP
THERMAL PACKING ACRS OUR CWA...INDICATES STRONG LOW TO MID LVL FGEN/WAA
FORCING ASSOCIATED WITH NOSE OF 40 TO 50 KNOT 85H JET AND RRQ OF
25H JET ACRS SOUTHERN CANADA. RESULTING IN A PERIOD OF DEEP LAYER
LIFT/MOISTURE...WITH GREATEST IMPACTS ACRS OUR CENTRAL/SOUTHERN CWA. VERY
EARLY INDICATIONS SUPPORT QPF RANGING FROM 0.25 INTERNATIONAL
BORDER TO 0.75" RUTLAND/WINDSOR COUNTIES...RESULTING IN ADVISORY
TYPE EVENT NEAR THE BORDER AND WARNINGS ACRS CENTRAL/SOUTHERN VT
ZNS. ANY SHIFT FURTHER NORTH OR SOUTH WOULD GREATLY IMPACT THE
AMOUNT OF QPF/SNOWFALL EXPECTED AND LLVL THERMAL PROFILES. WL CONT
TO MENTION CAT POPS FOR WEDS WITH THERMAL SOUNDINGS SUPPORTING ALL
SNOW FOR OUR ENTIRE CWA. SNOW WL TAPER OFF WEDS NIGHT INTO
THURSDAY WITH A BRIEF PERIOD OF UPSLOPE SNOW SHOWERS
POSSIBLE...BUT DRIER AIR ASSOCIATED WITH SFC HIGH PRES BUILDS INTO
OUR REGION. EXPECT NEAR NORMAL TEMPS FOR THE PERIOD WITH DAILY
HIGHS IN THE 20S AND LOWS IN THE SINGLE DIGITS/TEENS...EXCEPT BLW
NORMAL READINGS ON THURS/FRIDAY ASSOCIATED WITH LLVL CAA BEHIND
DEPARTING SFC LOW PRES. ANOTHER SYSTEM MAY IMPACT OUR REGION NEXT
WEEKEND AS ACTIVE STORM PATTERN DEVELOPS WITH POTENTIAL SYSTEMS
EVERY COUPLE OF DAYS.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
THROUGH 18Z SUNDAY...AVIATION FOCUS WL BE TIMING OF SNOW THIS
AFTN/EVENING AND ASSOCIATED IFR/LIFR CONDITIONS. CRNT RADAR SHOWS
LIGHT SNOW WITH BANDS OF MODERATE SNOW QUICKLY MOVING FROM SW TO
NE TWD CENTRAL/NORTHERN NY THIS AFTN. LEADING EDGE OF PRECIP IS
FALLING AS VIRGA IS LLVLS ARE VERY DRY WITH SFC TEMP/DWPT SPREADS
OF 10 TO 15 DEGREES ACRS OUR REGION. USING THE TIME OF ARRIVAL
TOOL AND LATEST RAP 13 DATA...THINKING SNOW DEVELOPS AT MSS/SLK BTWN
18Z-19Z WITH IFR CONDITIONS BY 20Z. FOR PBG/BTV THINKING SNOW
DEVELOPS BY 21Z WITH IFR CONDITIONS FOR VIS BTWN 1-2SM DEVELOPING
BY 22Z TONIGHT. A PERIOD OF LIFR CONDITIONS ARE LIKELY WITH VIS
<1/2SM AND CIGS AROUND 1000 FEET FOR SLK/MSS BTWN 22Z-03Z THIS
EVENING. OTHERWISE...EXPECT IFR CONDITIONS AT MPV BY 23Z AND
MAINLY MVFR CONDITIONS PREVAILING AT RUT AS BEST MOISTURE/LIFT IS
NORTH OF THIS TAF SITE. THE HEAVIER AND STEADIER PRECIP WL EXIT
OUR TAF SITES BY 06Z WITH EXCEPTION OF SLK/MSS...WHICH WL CONT TO
SEE PERIODS OF -SN WITH IFR CONDITIONS PREVAILING. THINKING BL
TEMPS WARM ENOUGH AT PBG/BTV FOR A MIXTURE OF -RASN BY 06Z WITH
VIS BTWN 3-5SM...ESPECIALLY AS BETTER LIFTS SHIFTS NORTH OF
REGION. A DEVELOPING SW JET OF 45 TO 55 KNOTS BTWN 2500 AND 3500
FT AGL WL PRODUCE AREAS OF TURBULENCE...ESPECIALLY IN THE
MTNS...WITH SOME SFC WIND GUSTS TO 20 KNOTS POSSIBLE. SOME LLVL WS
WL BE POSSIBLE AT MSS WITH NE SFC FLW OF 10 KNTS...WHILE FLW ALOFT
IS FROM THE SW.
OUTLOOK 18Z SUNDAY THROUGH WEDNESDAY...COLD FRNT SWEEPS ACRS OUR
CWA BTWN 15Z-21Z SUNDAY WITH ANOTHER BRIEF PERIOD OF PRECIP
POSSIBLE WITH MVFR/IFR CONDITIONS AND A WIND SHIFT TO THE W/NW.
SFC HIGH PRES WITH VFR CONDITIONS WL PREVAIL FROM 00Z MONDAY THRU
06Z WEDS. NEXT SYSTEM WITH WIDESPREAD SNOW AND IFR CONDITIONS WL
IMPACT OUR TAF SITES BY 12Z WEDS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL 11 AM EST SUNDAY FOR VTZ002>004-
006-007-016.
NY...WINTER WEATHER ADVISORY UNTIL 11 AM EST SUNDAY FOR NYZ026>031-
034-087.
&&
$$
SYNOPSIS...JN
NEAR TERM...JMG
SHORT TERM...JN
LONG TERM...TABER
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1251 PM EST SAT FEB 1 2014
.SYNOPSIS...
LOW PRESSURE ALONG A FRONTAL BOUNDARY WILL BRING A MIX OF
PRECIPITATION TO THE NORTH COUNTRY...STARTING THIS AFTERNOON...THEN
TAPER OFF ON SUNDAY. HIGH PRESSURE BUILDS OVER THE AREA SUNDAY NIGHT
INTO NEXT TUESDAY NIGHT...FOLLOWED BY ANOTHER STORM SYSTEM MIDWEEK
WITH HIGH PRESSURE RETURNING GOING INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1203 PM EST SATURDAY...MINOR ADJUSTMENT TO UPGRADE SOUTHWEST
ST LAWRENCE COUNTY IN THE EXISTING WINTER WX ADVSY THIS
AFTERNOON/TONIGHT. LATEST 12Z MODEL SUITE INCLUDING THE 15Z RAP
ANALYSIS STILL IN GOOD AGREEMENT SHOWING A WIDESPREAD LIGHT TO
MODERATE WINTER PCPN EVENT AFFECTING OUR AREA LATER TODAY TONIGHT
AS LOW PRESSURE TRACKS THROUGH THE SLV. FAIRLY ROBUST WARM THERMAL
ADVECTION ON THE NOSE OF 50-60KT 850 JET ALONG WITH INCREASINGLY
DEEP MOISTURE SHOULD BE MORE THAN SUFFICIENT TO PRODUCE WIDESPREAD
PCPN ON THE ORDER OF A QUARTER TO A HALF AN INCH ACROSS THE
SLV/NRN DACKS AND NRN GREENS. LESSER AMTS ELSEWHERE (0.25 OR LESS)
CHAMPLAIN/CT RVR VALLEYS AND MUCH OF SOUTH CENTRAL VT WHICH WILL
BE AFFECTED TO A CONSIDERABLE DEGREE BY DOWNSLOPING EFFECTS. PCPN
MAY ALSO MIX WITH PERIODS OF SLEET OR EVEN RAIN AT TIMES...NAMELY
AT PCPN ONSET WHEN NEAR-SFC TEMPS ARE THE MILDEST...AND AGAIN
OVERNIGHT WHEN MID-LEVEL WARM NOSE REACHES MOST NORTHWARD EXENT.
NONETHELESS...FEEL WITH SUCH DRY TD VALUES WET BULB PROCESSES WILL
TEND TO DOMINATE AND MOST OF THE PCPN...ESP IN THE ADVSY AREA WILL
FALL IN THE FORM OF SNOW. LOOKING AT AMOUNTS GENERALLY IN THE
2-5/3-6 INCH RANGE IN THE ADVSY AREA BY MORNING WITH ISOLATED
AMOUNTS TO PERHAPS 7/8 INCHES IN FAVORED HIGHER ELEV SPOTS.
ELSEWHERE...A GENERAL DUSTING TO 2 INCHES LOOKS REASONABLE WITH
LOWEST AMOUNTS FAR SOUTHERN VT WHICH WILL BE FURTHER REMOVED FROM
BEST WAA/DYNAMICS. AFOREMENTIONED SHADOWING EFFECTS MAY ALSO
PRODUCE A LOCAL MINIMUM IN THE IMMEDIATE KPBG/KBTV VCNTY...ESP
AFTER INITIAL WARM ADVECTION PCPN BURST WHEN CORE OF SOUTHWESTERLY
850 JET MOVES INTO THE AREA. HIGHS TODAY GENERALLY LOWER TO MID
30S...THEN MID TO UPPER 20S TONIGHT UNDER CONTINUED
SOUTH/SOUTHWESTERLY FLOW.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
AS OF 410 AM EST SATURDAY...GOING INTO SUNDAY...FRONTAL BOUNDARY
CONTINUES PUSH THRU THE AREA WITH ANY REMAINING PRECIP GOING OVER
TO ALL -SW AS COLDER AIR BEGINS TO FILTER INTO AREA. EXPECTING
EARLY HIGHS FOR THE CWA AS TEMPS SLOWLY DROP THRU THE MORNING HRS.
ADDITIONAL INCH OR SO IS POSSIBLE IN AREAS WHERE ADVISORY IS UP
WITH LESSER AMTS SOUTH. BY SUNDAY AFTNOON...FRONTAL BOUNDARY HAS
CLRD THE CWA...LEAVING AREA UNDER WNW FLOW. EXPECTING SOME
LINGERING -SW DUE TO UPSLOPE/OROGRAPHIC EFFECTS W/ ADDITIONAL
LIGHT ACCUM...MAINLY OVER HIGHER TRRN. GOING INTO SUN EVENING/NGT...
PRECIP WILL HAVE TAPERED OFF AND GIVE WAY TO STRONG SFC RIDGE
BUILDING EAST FROM THE GREAT LKS REGION. GENERAL CLRING TREND WILL
ENSUE AND CONTINUE THRU THE MONDAY TIME FRAME PROVIDING AREA A NICE
DAY. OVERALL FOR TEMPS...NEAR NORMAL WITH HIGHS IN THE 20S MONDAY
AND LOWS IN THE TEEN TO SINGLE NUMBERS UNDER CLRING SKIES SUN
NGT. SUNDAY WILL SEE HIGHS IN THE LOW 30S EAST AND 20S WEST.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 328 AM EST SATURDAY...OBJECTIVE FORECAST UNCERTAINTY LESS
THAN NORMAL THIS PERIOD PER RELATIVELY SMALL GFS ENSEMBLE SPREAD
AT BTV. GOOD SUBJECTIVE AGREEMENT BETWEEN 00Z GFS/ECMWF ALSO
NOTED.
QUIET WX TO START MON NIGHT THRU TUE WITH 1030MB SFC ANTICYCLONE
CRESTING OVER THE NERN CONUS. THIS SYSTEM BRINGS LIGHT WINDS AND
GOOD PROSPECTS FOR CLEAR SKIES. GOOD RADIATIONAL COOLING MONDAY
NIGHT ALLOWS LOWS TO DIP INTO THE SINGLE DIGITS TO LOWER
TEENS...FOLLOWED BY SEASONABLE HIGH TEMPS TUE IN THE MID-UPR 20S.
IT STILL APPEARS THAT SRN STREAM SHORTWAVE TROUGH EMERGING FROM
THE LWR MS RIVER VALLEY WILL RESULT IN DEEPENING SFC CYCLONE
ACROSS THE TN AND UPR OH RIVER VALLEY TUE NIGHT INTO WED MORNING.
LOW-LEVEL TRAJECTORIES FROM THE GULF OF MEXICO RESULT IN NWD
ADVECTION OF RICH MOISTURE WITH PW VALUES OF 1-1.25" ACROSS THE
CENTRAL APPALACHIANS AT 12Z WED. IT APPEAR FOR OUR REGION THAT
CLOUDS WILL QUICKLY INCREASE TUESDAY NIGHT WITH LEADING WAA/
PROGRESSIVE FRONTOGENETIC SNOWFALL DEVELOPING SW-NE ACROSS OUR
REGION 06-12Z WEDNESDAY. SNOW SHOULD BECOME STEADY QUICKLY GIVEN
STRENGTH OF FORCING AND MOISTURE ADVECTION. AS OF NOW...LOOKS LIKE
ALL SNOW AS PRIMARY LOW WEAKENS AS IT TRACKS INTO PA 18Z WED AND
REDEVELOPS SOUTH OF LONG ISLAND. STILL CAN/T RULE OUT THE
POSSIBILITY THAT MODELS TREND FURTHER WEST WITH THIS SYSTEM...WITH
PROSPECTS FOR RAIN MIXING IN. HOWEVER...AT THIS TIME THE COASTAL
REDEVELOPMENT IS CONSISTENT ENOUGH IN THE MODELS THAT WE HAVEN/T
INDICATED ANY MIXED PCPN/RAIN IN THE OFFICIAL FCST. 700MB TROUGH
REMAINS AN OPEN WAVE...SO LIKELY LOOKING AT A ~12 HR PERIOD OF
ACCUMULATING SNOWFALL PRE-DAWN HOURS WED THRU WEDNESDAY
EVENING...WITH POSSIBILITY OF LINGERING SNOW SHOWER ACTIVITY
WEDNESDAY NIGHT. AT THE MOMENT INDICATIONS ARE THAT 6"+ OF
SNOWFALL ARE POSSIBLE BASED ON STRENGTH OF SYNOPTIC FORCING AND
RICH MOISTURE AVAILABILITY. HAVE MAINTAINED MENTION IN THIS
MORNING/S HAZARDOUS WX OUTLOOK. HIGHS WEDNESDAY GENERALLY 26-30F.
THE WORK WEEK ENDS QUIET WITH DRY CONDITIONS EXPECTED THURSDAY AND
FRIDAY. TEMPS TREND COLDER WITH NWLY FLOW. HIGHS GENERALLY UPR
TEENS THU/FRI WITH LOW TEMPERATURES IN THE SINGLE DIGITS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
THROUGH 18Z SUNDAY...AVIATION FOCUS WL BE TIMING OF SNOW THIS
AFTN/EVENING AND ASSOCIATED IFR/LIFR CONDITIONS. CRNT RADAR SHOWS
LIGHT SNOW WITH BANDS OF MODERATE SNOW QUICKLY MOVING FROM SW TO
NE TWD CENTRAL/NORTHERN NY THIS AFTN. LEADING EDGE OF PRECIP IS
FALLING AS VIRGA IS LLVLS ARE VERY DRY WITH SFC TEMP/DWPT SPREADS
OF 10 TO 15 DEGREES ACRS OUR REGION. USING THE TIME OF ARRIVAL
TOOL AND LATEST RAP 13 DATA...THINKING SNOW DEVELOPS AT MSS/SLK BTWN
18Z-19Z WITH IFR CONDITIONS BY 20Z. FOR PBG/BTV THINKING SNOW
DEVELOPS BY 21Z WITH IFR CONDITIONS FOR VIS BTWN 1-2SM DEVELOPING
BY 22Z TONIGHT. A PERIOD OF LIFR CONDITIONS ARE LIKELY WITH VIS
<1/2SM AND CIGS AROUND 1000 FEET FOR SLK/MSS BTWN 22Z-03Z THIS
EVENING. OTHERWISE...EXPECT IFR CONDITIONS AT MPV BY 23Z AND
MAINLY MVFR CONDITIONS PREVAILING AT RUT AS BEST MOISTURE/LIFT IS
NORTH OF THIS TAF SITE. THE HEAVIER AND STEADIER PRECIP WL EXIT
OUR TAF SITES BY 06Z WITH EXCEPTION OF SLK/MSS...WHICH WL CONT TO
SEE PERIODS OF -SN WITH IFR CONDITIONS PREVAILING. THINKING BL
TEMPS WARM ENOUGH AT PBG/BTV FOR A MIXTURE OF -RASN BY 06Z WITH
VIS BTWN 3-5SM...ESPECIALLY AS BETTER LIFTS SHIFTS NORTH OF
REGION. A DEVELOPING SW JET OF 45 TO 55 KNOTS BTWN 2500 AND 3500
FT AGL WL PRODUCE AREAS OF TURBULENCE...ESPECIALLY IN THE
MTNS...WITH SOME SFC WIND GUSTS TO 20 KNOTS POSSIBLE. SOME LLVL WS
WL BE POSSIBLE AT MSS WITH NE SFC FLW OF 10 KNTS...WHILE FLW ALOFT
IS FROM THE SW.
OUTLOOK 18Z SUNDAY THROUGH WEDNESDAY...COLD FRNT SWEEPS ACRS OUR
CWA BTWN 15Z-21Z SUNDAY WITH ANOTHER BRIEF PERIOD OF PRECIP
POSSIBLE WITH MVFR/IFR CONDITIONS AND A WIND SHIFT TO THE W/NW.
SFC HIGH PRES WITH VFR CONDITIONS WL PREVAIL FROM 00Z MONDAY THRU
06Z WEDS. NEXT SYSTEM WITH WIDESPREAD SNOW AND IFR CONDITIONS WL
IMPACT OUR TAF SITES BY 12Z WEDS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL 11 AM EST SUNDAY FOR VTZ002>004-
006-007-016.
NY...WINTER WEATHER ADVISORY UNTIL 11 AM EST SUNDAY FOR NYZ026>031-
034-087.
&&
$$
SYNOPSIS...JN
NEAR TERM...JMG
SHORT TERM...JN
LONG TERM...BANACOS
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
930 AM EST SAT FEB 1 2014
.SYNOPSIS...
LOW PRESSURE ALONG A FRONTAL BOUNDARY WILL BRING A MIX OF
PRECIPITATION TO THE NORTH COUNTRY...STARTING THIS AFTERNOON...THEN
TAPER OFF ON SUNDAY. HIGH PRESSURE BUILDS OVER THE AREA SUNDAY NIGHT
INTO NEXT TUESDAY NIGHT...FOLLOWED BY ANOTHER STORM SYSTEM MIDWEEK
WITH HIGH PRESSURE RETURNING GOING INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
AS OF 930 AM EST SATURDAY...GOING FORECAST IN DECENT SHAPE AND ONLY
SOME MINOR ADJUSTMENTS TO SKY COVER AND T/TD DATASESTS NEEDED AS
WE PROGRESS THROUGH THE DAY TODAY. LATEST RAP AND INCOMING NAM
CONFIRMING THAT TONIGHT`S SYSTEM STILL ON TRACK TO AFFECT AREA
WITH WIDESPREAD LIGHT SNOWS AND PERHAPS A WINTRY MIX SOUTH. WITH
A SFC LOW TRACK THROUGH THE SLV IN THE VCNTY OF OTTAWA...SOUTHWEST
FLOW OF NEARLY 50 KTS WILL DEVELOP ACROSS THE AREA...WITH ENHANCED
SHADOWING EFFECTS LIKELY IN THE IMMEDIATE CHAMPLAIN VALLEY
TONIGHT. THEREFORE INCREASING CONFIDENCE THAT CURRENT QPF AMOUNTS
OF AROUND 1/3 INCH IN THE BTV/PBG VCNTY WILL NEED TO BE LOWERED.
PRIOR DISCUSSION BELOW. HAVE A GREAT DAY.
PREVIOUS DISCUSSION...CLD COVER ASSOCIATED WITH FRONTAL BOUNDARY
TO OUR SOUTH CONTINUES TO STREAM THRU THE AREA THIS MORNING...INCR
IN NATURE AS DAY PROGRESSES. THIS WILL BE AIDED BY SFC LOW MVG UP
ALONG THE FRONT LATER TODAY INTO TONIGHT. ATTM...PRECIP IS
REMAINING TO OUR SOUTH CLOSER TO BOUNDARY WITH NONE OUT AHEAD. AS
SFC LOW WORKS NORTH TODAY...LIGHT SNOW WILL BEGIN TO DEVELOP BY
EARLY AFTERNOON...OVERSPREADING MUCH OF AREA BY LATE AFTNOON. WITH
MDLS CARRYING SFC LOW WEST OF THE CWA THRU REST OF DAY AND INTO
THE EVENING/OVERNGT HRS...WARM AIR WILL WORK INTO THE
CENTRAL/SOUTHERN PORTIONS OF THE CWA...ALLOWING FOR RAIN/SNOW
MIX...BFR GOING SLOWLY TO ALL LIGHT SNOW DURING THE OVERNGT HRS.
0C 925/850 MB LINES WORK UP INTO SOUTHERN PORTIONS OF THE DACKS
AND ACROSS CENTRAL VT AT PEAK OF PRECIP POTENTIAL.THUS EXPECT SNOW
WITH POSSIBLE MIX OF SLEET IN MOST NORTHERN BORDER ZONES/DACKS.
HAVE CONTINUED WINTER WX ADVISORY IN THESE AREAS...BUT HAVE
DELAYED STARTING TIME BY A FEW HRS AND TRIMMED BACK ON TOTALS ON
ACCUM FROM 4-6" TO 3-5" BASED ON TRACK OF LOW. ELSEWHERE WITH WARM
AIR INTRUSION MIX OF SNOW/SLEET/RAIN AND SPOTTY FZRA ARE STILL ON
TAP WITH A DUSTING TO 2 INCHES ACCUM POSSIBLE. HIGHS FOR TODAY IN
THE 30S WITH OVERNGT LOWS MAINLY IN THE 20S WITH SPOT 30S IN THE
CVLY.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH MONDAY/...
AS OF 410 AM EST SATURDAY...GOING INTO SUNDAY...FRONTAL BOUNDARY
CONTINUES PUSH THRU THE AREA WITH ANY REMAINING PRECIP GOING OVER
TO ALL -SW AS COLDER AIR BEGINS TO FILTER INTO AREA. EXPECTING
EARLY HIGHS FOR THE CWA AS TEMPS SLOWLY DROP THRU THE MORNING HRS.
ADDITIONAL INCH OR SO IS POSSIBLE IN AREAS WHERE ADVISORY IS UP
WITH LESSER AMTS SOUTH. BY SUNDAY AFTNOON...FRONTAL BOUNDARY HAS
CLRD THE CWA...LEAVING AREA UNDER WNW FLOW. EXPECTING SOME
LINGERING -SW DUE TO UPSLOPE/OROGRAPHIC EFFECTS W/ ADDITIONAL
LIGHT ACCUM...MAINLY OVER HIGHER TRRN. GOING INTO SUN EVENING/NGT...
PRECIP WILL HAVE TAPERED OFF AND GIVE WAY TO STRONG SFC RIDGE
BUILDING EAST FROM THE GREAT LKS REGION. GENERAL CLRING TREND WILL
ENSUE AND CONTINUE THRU THE MONDAY TIME FRAME PROVIDING AREA A NICE
DAY. OVERALL FOR TEMPS...NEAR NORMAL WITH HIGHS IN THE 20S MONDAY
AND LOWS IN THE TEEN TO SINGLE NUMBERS UNDER CLRING SKIES SUN
NGT. SUNDAY WILL SEE HIGHS IN THE LOW 30S EAST AND 20S WEST.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 328 AM EST SATURDAY...OBJECTIVE FORECAST UNCERTAINTY LESS
THAN NORMAL THIS PERIOD PER RELATIVELY SMALL GFS ENSEMBLE SPREAD
AT BTV. GOOD SUBJECTIVE AGREEMENT BETWEEN 00Z GFS/ECMWF ALSO
NOTED.
QUIET WX TO START MON NIGHT THRU TUE WITH 1030MB SFC ANTICYCLONE
CRESTING OVER THE NERN CONUS. THIS SYSTEM BRINGS LIGHT WINDS AND
GOOD PROSPECTS FOR CLEAR SKIES. GOOD RADIATIONAL COOLING MONDAY
NIGHT ALLOWS LOWS TO DIP INTO THE SINGLE DIGITS TO LOWER
TEENS...FOLLOWED BY SEASONABLE HIGH TEMPS TUE IN THE MID-UPR 20S.
IT STILL APPEARS THAT SRN STREAM SHORTWAVE TROUGH EMERGING FROM
THE LWR MS RIVER VALLEY WILL RESULT IN DEEPENING SFC CYCLONE
ACROSS THE TN AND UPR OH RIVER VALLEY TUE NIGHT INTO WED MORNING.
LOW-LEVEL TRAJECTORIES FROM THE GULF OF MEXICO RESULT IN NWD
ADVECTION OF RICH MOISTURE WITH PW VALUES OF 1-1.25" ACROSS THE
CENTRAL APPALACHIANS AT 12Z WED. IT APPEAR FOR OUR REGION THAT
CLOUDS WILL QUICKLY INCREASE TUESDAY NIGHT WITH LEADING WAA/
PROGRESSIVE FRONTOGENETIC SNOWFALL DEVELOPING SW-NE ACROSS OUR
REGION 06-12Z WEDNESDAY. SNOW SHOULD BECOME STEADY QUICKLY GIVEN
STRENGTH OF FORCING AND MOISTURE ADVECTION. AS OF NOW...LOOKS LIKE
ALL SNOW AS PRIMARY LOW WEAKENS AS IT TRACKS INTO PA 18Z WED AND
REDEVELOPS SOUTH OF LONG ISLAND. STILL CAN/T RULE OUT THE
POSSIBILITY THAT MODELS TREND FURTHER WEST WITH THIS SYSTEM...WITH
PROSPECTS FOR RAIN MIXING IN. HOWEVER...AT THIS TIME THE COASTAL
REDEVELOPMENT IS CONSISTENT ENOUGH IN THE MODELS THAT WE HAVEN/T
INDICATED ANY MIXED PCPN/RAIN IN THE OFFICIAL FCST. 700MB TROUGH
REMAINS AN OPEN WAVE...SO LIKELY LOOKING AT A ~12 HR PERIOD OF
ACCUMULATING SNOWFALL PRE-DAWN HOURS WED THRU WEDNESDAY
EVENING...WITH POSSIBILITY OF LINGERING SNOW SHOWER ACTIVITY
WEDNESDAY NIGHT. AT THE MOMENT INDICATIONS ARE THAT 6"+ OF
SNOWFALL ARE POSSIBLE BASED ON STRENGTH OF SYNOPTIC FORCING AND
RICH MOISTURE AVAILABILITY. HAVE MAINTAINED MENTION IN THIS
MORNING/S HAZARDOUS WX OUTLOOK. HIGHS WEDNESDAY GENERALLY 26-30F.
THE WORK WEEK ENDS QUIET WITH DRY CONDITIONS EXPECTED THURSDAY AND
FRIDAY. TEMPS TREND COLDER WITH NWLY FLOW. HIGHS GENERALLY UPR
TEENS THU/FRI WITH LOW TEMPERATURES IN THE SINGLE DIGITS.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 12Z SUNDAY...GENERALLY VFR THRU 18Z...THEN DEVELOPING MVFR
WITH INTERVALS OF IFR IN LIGHT SNOW BEGINNING MID AFTN. SKIES HAVE
BRIEFLY CLEARED THIS MORNING WITH SCT200-250 ANTICIPATED THRU 15Z.
ONLY EXCEPTION IS NRN ADIRONDACKS AND KSLK VCNTY...WHERE LOW
STRATUS WILL PERSIST WITH LOCAL CIGS BKN-OVC015-025 WITH HIR TRRN
OBSCD. MID-LEVEL CLOUDS (CIGS NEAR 10 KFT) WILL INCREASE RAPIDLY
LATE THIS MORNING INTO THE EARLY AFTN HOURS. APPROACHING WARM
FRONT THIS AFTERNOON ALLOWS LIGHT SNOW TO OVERSPREAD NRN NY 18-21Z
AND ACROSS VT 21-00Z...WITH PERIODS OF SNOW CONTINUING AT THE TAF
SITES THRU TONIGHT. GENERALLY 1-2SM -SN EXPECTED WITH SOME IMPACT
TO AVIATION GROUND OPERATIONS EXPECTED TOWARD THIS EVENING. MAY
SEE SOME MIX WITH DRIZZLE OR LIGHT RAIN AFTER MIDNIGHT TONIGHT AT
RUT AND BTV. WINDS WILL GENERALLY INCREASE FROM THE S-SE DURING
THE DAYLIGHT HRS TO AROUND 10-12 KTS WITH GUSTS 15-20 KTS AT BTV.
GRADIENT WIND REMAINS STRONG TONIGHT AS SURFACE LOW PASSES WEST OF
THE REGION. ANTICIPATE SOUTH WINDS OF 10-20 KTS DURING MOST OF
SATURDAY NIGHT.
OUTLOOK 12Z SUNDAY THROUGH WEDNESDAY...COLD FRONT SHIFTS EWD ACROSS
THE AREA BRINGING SNOW SHOWER ACTIVITY SUNDAY INTO EARLY SUNDAY
NIGHT. SNOW SHOWERS WILL BE MOST FREQUENT AT MPV/SLK WITH FAVORED
OROGRAPHIC INFLUENCES. DRY AND VFR CONDS MONDAY AND TUESDAY WITH
HIGH PRESSURE IN PLACE. MOISTURE LADEN FRONTAL SYSTEM APPROACHING
FROM THE TN RIVER VALLEY BRINGS ADDITIONAL SNOW EXPECTED WEDNESDAY
INTO WEDNESDAY NIGHT WITH WIDESPREAD IFR CONDITIONS AND IMPACT TO
AIRPORT GROUND OPS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 11 AM EST
SUNDAY FOR VTZ002>004-006-007-016.
NY...WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 11 AM EST
SUNDAY FOR NYZ026>031-034.
&&
$$
SYNOPSIS...JN
NEAR TERM...JMG/JN
SHORT TERM...JN
LONG TERM...BANACOS
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
955 PM EST SUN FEB 2 2014
.SYNOPSIS...A DEVELOPING LOW PRESSURE SYSTEM OVER THE LOWER MS
VALLEY WILL TRACK NORTHEAST INTO THE STATE LATE TONIGHT AND WILL
MOVE OFF THE VA TIDEWATER COAST BY MONDAY AFTERNOON. HIGH PRESSURE
WILL BUILD BRIEFLY INTO THE AREA MONDAY NIGHT AND TUESDAY...BEFORE
THE OLD FRONT TO OUR SOUTH LIFTS BACK NORTHWARD AS A WARM FRONT
TUESDAY NIGHT. ANOTHER COLD FRONT WILL MOVE THROUGH THE AREA ON
WEDNESDAY.
&&
.NEAR TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 955 PM SUNDAY...
PRECIP STREAMING ALONG THE FRONTAL ZONE WEST OF THE MOUNTAINS WILL
EVENTUALLY SHIFT EAST INTO THE WESTERN PIEDMONT TONIGHT...ESPECIALLY
ONCE A SHORTWAVE OVER THE LOW MISSISSIPPI VALLEY LIFTS TO THE
TENNESSEE VALLEY BY 12Z. THE 00Z KGSO RAOB SHOWS THAT THERE IS
STILL A LOT OF DRY AIR EAST OF THE MOUNTAINS HOWEVER. THE 50KT
PREFRONTAL LOW-LEVEL JET ANALYZED UPSTREAM IS ADVECTING BETTER
MOISTURE OUR WAY...BUT ISENTROPIC FIELDS AND RADAR TRENDS SUGGEST
PRECIP WILL VERY MUCH BE FOCUSED OVER THE NORTHWEST PIEDMONT UNTIL
THE FRONT AND WEAK SURFACE LOW CROSS THE MOUNTAINS AROUND 15Z. THUS
HAVE TRIMMED POPS TO JUST SLIGHT CHANCE OVER THE EASTERN HALF OF THE
CWA. THE RAP STILL SHOWS A LITTLE ELEVATED INSTABILITY WORKING
NORTH INTO THE CWA LATE TONIGHT...BUT FORCING OUTSIDE OF THE
LLJ/WARM ADVECTION IS WEAK PRIOR TO THE ARRIVAL OF THE SHORTWAVE AND
FRONT...SO ANY THUNDER WILL BE VERY ISOLATED. OVER THER
EAST...LOWER DEWPOINT DEPRESSIONS AND AND THINNER HIGH CLOUDS MAY
ALLOW SOME PATCHY FOG TO DEVELOP OVER THE SANDHILLS AND COASTAL
PLAIN. LOWS ARE LIKELY TO OCCUR IN THE NEXT FEW HOURS BEFORE
SOUTHERLY FLOW PICKS UP AND THICKER CLOUD COVER KICKS IN. WILL MAKE
SOME ADJUSTMENTS TO LOWS BASED ON CURRENT READINGS...WITH MID 50S
WEST AND MID/UPPER 40S EAST.
MONDAY...
PRECIP WILL SHIFT EAST ACROSS THE CWA DURING THE DAY MONDAY
AS THE COLD FRONT PUSHES SOUTHEAST. THE BEST UPPER FORCING WILL
MOVE OFF TO THE NORTHEAST...LEAVING MAINLY LOW-LEVEL CONVERGENCE AND
POSSIBLY SOME WEAK INSTABILITY OVER THE SOUTH TO KEEP SHOWERS GOING.
EXPECT A SHARP DROP OFF IN PRECIP AMOUNTS...AROUND 0.75" NORTH TO
WELL UNDER 0.25" SOUTH. TEMPERATURES ACROSS THE NORTH WILL
INITIALLY FALL BEHIND THE FRONTAL PASSAGE DURING THE MORNING HOURS
AND THEN HOLD NEARLY STEADY INTO THE AFTERNOON...WHILE TEMPERATURES
COULD WARM WELL INTO THE MID TO UPPER 60S ACROSS THE SE BEFORE THE
ARRIVAL THE FRONT AND PRECIP COOLS TEMPERATURES BACK DOWN INTO THE
50S. -SMITH/CBL
MONDAY NIGHT:
A ~1030MB OVER THE OHIO VALLEY WILL BUILD EASTWARD INTO THE REGION
MONDAY EVENING/NIGHT AS THE FRONT SLIPS SOUTH AND EAST OF THE AREA.
COULD SEE A LULL IN PRECIP MONDAY EVENING BEFORE WE ALREADY TO START
TO HAVE IMPACTS FROM THE NEXT SYSTEM WITH A RESURGENCE OF SHALLOW
SOUTHERLY 295K ISENTROPIC UPGLIDE LATE..BETWEEN 06 TO 12Z...WITH
SOME PATCHY DRIZZLE POSSIBLE ACROSS THE ENTIRE FORECAST AREA. DO NOT
EXPECT P-TYPE CONCERNS...WITH LOWS IN THE MID 30S NORTH TO UPPER 30S
SOUTH. -CBL
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 303 PM SUNDAY...
AN ACTIVE SPLIT FLOW PATTERN WILL MAINTAIN AN UNSETTLED WEATHER
PATTERN ACROSS CENTRAL NC THIS PERIOD.
ON TUESDAY...A PARENT SURFACE HIGH (1030+ MB) WILL BE POSITIONED
OVER NEW ENGLAND...NOSING SWD ITO THE CAROLINAS. MEANWHILE A S/W IN
THE SOUTHERN STREAM WILL BE LIFTING ENE ACROSS TX INTO THE LOWER MS
VALLEY. THIS SYSTEM WILL ENHANCE SLY FLOW IN THE 925-850MB LAYER
AFTER 12Z TUESDAY...AND ESPECIALLY TUESDAY AFTERNOON. THIS FLOW WILL
PULL WARM MOIST AIR OVER THE COOL DRY STABLE AIRMASS NEAR THE
SURFACE...ESTABLISHING AN OVERRUNNING EVENT AND ASSOCIATED HYBRID
COLD AIR DAMMING EPISODE. EXPECT AREAS OF LIGHT RAIN TO DEVELOP
TUESDAY MORNING THEN SPREAD NORTH ACROSS THE REGION THROUGH THE
AFTERNOON AND EARLY EVENING HOURS. IF PRECIP WERE TO START PRIOR TO
15Z ACROSS THE TRIAD REGION...COULD SEE PRECIP START OUT AS PATCHY
FREEZING RAIN (PER PARTIAL THICKNESSES). HOWEVER MODEL TREND HAS
FAVORED A LATER STARTING TIME...DEVELOPING ACROSS THE SOUTH DURING
THE EARLY-MID MORNING HOURS THEN LIFTING NWD INTO THE NORTHERN
PIEDMONT LATE MORNING-EARLY AFTERNOON.
DUE TO EXPECTED ONSET OF CAD CONDITIONS...EXPECT TEMPS TO AVERAGE
WELL BELOW NORMAL. WHILE THIS IS REFLECTED IN MOS GUIDANCE...
GUIDANCE MAY STILL BE TOO WARM BY TWO CATEGORIES... ESPECIALLY
ACROSS THE NW PIEDMONT. MAX TEMPS UPPER 30S NW TO MID-UPPER 40S SE.
PRECIP SHOULD BE GENERALLY LIGHT AS MAIN LIFTING MECHANISM IS
ISENTROPIC LIFT AND LITTLE SUPPORT/LIFT FROM JET DYNAMICS.
MAIN THRUST OF ISENTROPIC LIFT WILL ADVANCE INTO VIRGINIA TUESDAY
EVENING. EXPECT THE WIDESPREAD RAIN ACROSS CENTRAL NC TO BECOME MORE
PATCHY...AND LIKELY BE MORE DRIZZLE THAN LIGHT RAIN BY LATE EVENING
INTO THE OVERNIGHT HOURS. MAIN SFC LOW ASSOCIATED WITH THE SOUTHERN
STREAM DISTURBANCE WILL LIFT ACROSS THE TN VALLEY WHILE A WEAKER
SECONDARY LOW DEVELOPS ALONG THE CAD BOUNDARY IN VICINITY OF OUR
COASTAL PLAIN. THIS LOW LIFTS NEWD AND EVENTUALLY BECOMES THE
PRIMARY LOW OFF THE JERSEY SHORE BY WEDNESDAY AFTERNOON. THIS LOW
WILL DRAG A SFC COLD FRONT ACROSS CENTRAL NC WEDNESDAY...EXITING THE
COASTAL PLAIN COUNTIES BY LATE AFTERNOON. WEDNESDAY WILL START OUT
WET WITH AREAS OF RAIN OR RAIN SHOWERS...TRANSITIONING TO MORE RAIN
EAST VERSUS WEST BY AFTERNOON AS THE FRONT CROSSES THE PIEDMONT. NW
FLOW BEHIND THE BOUNDARY WILL AID TO SCOUR OUT THE RESIDUAL CAD
AIRMASS. THIS WILL TRANSLATE TO WARMER TEMPS WEDNESDAY VERSUS
TUESDAY WITH HIGH TEMPS RANGING FROM UPPER 50S/60 NW TO UPPER 60S/70
SE.
DRIER AND MORE STABLE CONDITIONS WEDNESDAY NIGHT AS COLD CANADIAN
AIR BUILDS INTO CENTRAL NC FROM THE N-NW. MIN TEMPS NEAR 30 NW TO
NEAR 40 SE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 340 PM SUNDAY...
ACTIVE SPLIT FLOW PATTERN PERSIST INTO THE LONG TERM WITH MUCH
UNCERTAINTY FOR TEH FRIDAY INTO SATURDAY PERIOD.
COLD CANADIAN AIR WILL BE CENTERED OVER THE CENTRAL U.S. BUT EXTEND
EAST INTO THE MID ATLANTIC THEN SWD INTO THE CAROLINAS. THIS PATTERN
USUALLY SIGNALS VERY SHALLOW COLD DRY AIR MOVING INTO AND SETTLING
INTO THE FORECAST AREA. EXPECT TRANQUIL WEATHER THURSDAY THOUGH MUCH
COOLER WITH HIGH TEMPS MID 40S NW TO LOWER 50S SE.
A SERIES OF UPPER LEVEL DISTURBANCES WILL AFFECT THE SOUTHERN U.S.
FRIDAY THROUGH SUNDAY. THE FIRST SYSTEM APPEARS TO BE MINOR AND
WEAKENS AS IT GETS CLOSER TO THE CAROLINAS. ECMWF CONTINUES TO
SUGGEST PRECIP POSSIBLE LATE THU NIGHT INTO FRI MORNING WHILE GFS
KEEPS PRECIP WELL TO THE SOUTH. ISENTROPIC LIFT ANEMIC ON THE ECMWF
SO THINK THAT THE PRECIP IS OVERDONE. WILL KEEP THURSDAY NIGHT DRY
AND HAVE A SLIGHT-SMALL CHANCE OF RAIN OVER CENTRAL NC FRIDAY. IF
RAIN DOES MATERIALIZE EARLY ENOUGH IN THE WESTERN-NW
PIEDMONT...PRECIP MAY START OUT AS WINTRY MIX.
SFC RIDGE AXIS FROM A PARENT HIGH OVER SOUTHERN NEW ENGLAND WILL
BUILD INTO THE CAROLINAS FRIDAY NIGHT INTO SATURDAY. MEANWHILE A
STRONGER SYSTEM ALOFT WILL APPROACH FROM THE SW. THIS SYSTEM WILL
INDUCE ANOTHER OVERRUNNING EVENT...COMMENCES FRIDAY NIGHT INTO
SATURDAY. THIS WILL TRIGGER A CLASSICAL DAMMING EVENT. STILL MUCH
UNCERTAINTY TO THE EXTENT/DEPTH OF THE SFC BASED COLD DRY AIR.
PARTIAL THICKNESSES OFF THE COLDER GFS WOULD SUPPORT A WINTRY MIX
(SLEET/FREEZING RAIN) WHILE ECMWF SUGGEST A COLD RAIN. THIS FAR
OUT...FAVOR A COLD RAIN AND MAINTAIN A WATCH ON MODEL TRENDS NEXT
DAY OR TWO. UNSETTLED CONDITIONS EXPECTED INTO EARLY SUNDAY...THEN
GRADUAL IMPROVEMENT AS TEH SYSTEM LIFTS TO THE NE. SLIGHTLY BETTER
SUPPORT ALOFT WITH THIS SYSTEM SUGGEST HIGHER PRECIP AMOUNTS
COMPARED TO THE TUESDAY-WEDNESDAY SYSTEM. MAX TEMPS FRIDAY UPEPR 30S
NW TO MID 40S BE...AND LOWER 40S NW TO LOWER 50S SE SAT AND SUNDAY.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 655 PM SUNDAY...
VFR CONDITIONS WILL HOLD THROUGH MUCH OF THIS EVENING... WITH A DRY
COLUMN IN PLACE AND LIGHT NEAR-SURFACE FLOW FROM THE SW. BUT THIS SW
FLOW WILL STRENGTHEN WITH RAPIDLY MOISTENING LOW LEVELS... AND A
QUICK DETERIORATION IN AVIATION CONDITIONS WILL FOLLOW LATER
TONIGHT... WITH A TREND TO IFR/LIFR CIGS/VSBYS STARTING SOON AFTER
06Z. THESE POOR AVIATION CONDITIONS ARE LIKELY TO DOMINATE THROUGH
THE REMAINDER OF THE FORECAST PERIOD (THROUGH EARLY MON EVENING)...
ALTHOUGH CIGS MAY BRIEFLY EDGE UP TO MVFR AFTER 21Z AT INT/GSO AS A
COLD FRONT DROPS IN FROM THE NW WITH DRIER AIR WORKING IN SLOWLY
FROM THE NORTH. LOW LEVEL WIND SHEAR IS ALSO LIKELY TO DEVELOP IN
THE 05Z-08Z TIME FRAME... PERSISTING UNTIL AROUND 14Z MON MORNING...
WITH LIGHT SW SURFACE WINDS AND 40-45 KT SW WINDS AT AROUND 1500 FT
AGL. RAIN IS EXPECTED TO SPREAD INTO INT/GSO SOON AFTER 08Z... AND
AT RDU AFTER 12Z. RAIN SHOULD BE MUCH LIGHTER AND MORE SPOTTY AT
RWI/FAY... OCCURRING LARGELY AFTER 16Z. RAIN CHANCES WILL DIMINISH
AFTER 16Z AT INT/GSO AND AFTER 20Z-22Z AT RDU/RWI/FAY.
LOOKING BEYOND 00Z TUE (EARLY MON EVENING): AN EXTENDED PERIOD OF
SUB-VFR CONDITIONS IS LIKELY THROUGH MUCH OF WED. MVFR TO IFR CIGS
ARE LIKELY WITH DRY WEATHER MON EVENING/NIGHT. PRECIP WILL RETURN
FROM THE SW STARTING TUE MORNING (MOSTLY RAIN BUT MAY START AS
FREEZING RAIN AT INT/GSO)... AND IS EXPECTED TO PERSIST ON-AND-OFF
WITH GENERALLY IFR CONDITIONS LASTING INTO WED AFTERNOON AS A
FRONTAL SYSTEM HOLDS OVER THE REGION WITH LOW PRESSURE CROSSING NC.
A TREND TO VFR IS EXPECTED STARTING LATE WED AS THE FRONT MOVES TO
OUR EAST AND HIGH PRESSURE BUILDS IN FROM THE WEST. IFR CONDITIONS
EXPECTED TO RETURN FRIDAY WITH THE APPROACH OF THE NEXT STORM
SYSTEM. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL/SMITH
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
102 PM EST SAT FEB 1 2014
.SYNOPSIS...WEAK HIGH PRESSURE REMAINS OVER THE REGION TONIGHT INTO
SUNDAY...AS MOISTURE INCREASES AND WEAK LOW PRESSURE DEVELOPS AND
MOVES NORTHEAST ALONG THE CAROLINA COAST. A COLD FRONT APPROACHES
FROM THE WEST SUNDAY AND BRIEFLY STALLS AS SURFACE LOW PRESSURE
MOVES NORTHEAST ALONG THE FRONT SUNDAY NIGHT INTO MONDAY. HIGH
PRESSURE BUILDS IN FROM THE NORTH MONDAY AFTERNOON.
&&
.NEAR TERM /THIS AFTERNOON AND TONIGHT/...
AS OF 950 AM SATURDAY...
WHILE SURFACE HIGH PRESSURE REMAINED OVER CENTRAL NORTH CAROLINA...
MOISTURE ADVECTION WAS TAKING PLACE FROM THE SOUTH. ALREADY ON THE
12Z UPPER-AIR SOUNDING AT KMHX...THERE WAS A NARROW LAYER OF GOOD
MOISTURE JUST BELOW 850MB...AND THE 12Z 850MB ANALYSIS SHOWED DEW
POINTS AT THAT LEVEL NEAR 10C INTO SOUTH CAROLINA. LIGHT
PRECIPITATION WAS NOTED ON REGIONAL RADAR RETURNS SOUTH OF CENTRAL
NORTH CAROLINA WITHIN A COUNTY OF THE BORDER...AND DURING THE
AFTERNOON THE RAP FORECASTS CONTINUED 850MB THETA-E ADVECTION INTO
THE AREA AS 850MB WINDS INCREASE TO 30 TO 35KT LATE IN THE DAY.
DIFFLUENCE ALOFT IS FORECAST TO BE WEAK...COINCIDENT WITH THE UPPER-
LEVEL STEADY SOUTHWEST FLOW OVER THE AREA...BUT IT SHOULD BE ENOUGH
WITH LOW-LEVEL MOISTENING AND JUST A LITTLE INSTABILITY TO RESULT IN
A CONTINUED NORTHWARD PROGRESSION OF AREAS OF LIGHT RAIN THIS
AFTERNOON INTO THIS EVENING. JUST BELOW THE INVERSION AROUND 700MB
THERE IS FORECAST LAYER MUCAPE AROUND 100J/KG...WHICH SHOULD HELP
SUPPORT THE AREAS OF RAIN AND POSSIBLY MAKE THE PRECIPITATION
SHOWERY AT TIMES ESPECIALLY EAST OF U.S. 1. RAP SOUNDINGS SHOWING A
CAP THROUGH THE EVENING JUST ABOVE 700MB SHOULD PRECLUDE ANY DEEP
CONVECTION. ADJUSTED THE TIMING OF PRECIPITATION JUST A LITTLE
FASTER ESPECIALLY OVER THE SANDHILLS... AND LEFT TEMPERATURES AS
PREVIOUSLY FORECAST AS THE RAPID PROGRESSION OF THE CLOUDS NORTH
COULD KEEP MAXES FROM REACHING POTENTIAL HIGHS WELL INTO THE 50S
BASED SIMPLY ON 1000-850MB THICKNESSES.
TONIGHT...THE BULK OF MODEL GUIDANCE SHOWS 0.03-0.08" OF MEASURABLE
PRECIP ACROSS CENTRAL NC...WITH THE RELATIVE HIGHEST AMOUNTS
ALONG/EAST OF HWY 1 WHERE THE SLIGHT ELEVATED INSTABILITY IS
FORECAST TO BE MARGINALLY GREATER ON THE RAP RELATIVE TO THE REST OF
CENTRAL NORTH CAROLINA. EXPECT THE AREAS OF LIGHT RAIN TO END FROM
WEST-EAST SHORTLY AFTER MIDNIGHT (BY ~06Z)...PERHAPS LINGERING AS
LATE AS 06-09Z IN THE COASTAL PLAIN. THIS IS VERY CLOSE TO WHAT THE
00Z HIGH RES WRF-NMM SIM REF PRODUCT SUGGESTS...WHICH SEEMS
REASONABLE. LOWS TONIGHT WILL BE RELATIVELY BALMY IN COMPARISON TO
PREVIOUS NIGHTS DUE TO PERVASIVE CLOUD COVER (THOUGH PERHAPS ERODING
IN THE WESTERN PIEDMONT NEAR SUNRISE SUN)...RANGING FROM THE UPPER
30S NW TO LOWER/MID 40S SE.
IN TERMS OF THE DENSE FOG POTENTIAL...TOP-DOWN DRYING WILL RAPIDLY
OCCUR AFTER MIDNIGHT AS LOW-LEVEL FLOW VEERS TO THE WSW AND ADVECTS
A DRIER AIRMASS INTO CENTRAL NC...ESPECIALLY IN THE FAR N/NW
PIEDMONT. THE MSLP GRADIENT WILL REMAIN VERY WEAK SUN MORNING...WITH
LITTLE SFC ADVECTION AND A HIGH LIKELIHOOD THAT SHALLOW SATURATION
(MOST SHALLOW IN NORTHERN/WESTERN PIEDMONT) WILL PERSIST THROUGH
SUNRISE. IF SUFFICIENT TOP-DOWN DRYING OCCURS PRIOR TO SUNRISE IT IS
POSSIBLE THAT DENSE FOG COULD DEVELOP ACROSS THE AREA. LATER
FORECASTS MAY NEED TO INTRODUCE AGAIN AT LEAST PATCHY FOG EAST
PARTICULARLY INTO THE COASTAL PLAIN...WHERE LINGERING SNOW COVER AND
COOL GROUND BELOW INCREASING MOISTURE MAY MAKE SUCH CONDITIONS AS
LEAST AS LIKELY AS ELSEWHERE.
&&
.SHORT TERM /SUNDAY/...
AS OF 330 AM SATURDAY...
SOUTHWEST FLOW WILL INCREASE DURING THE DAY SUNDAY AS THE MSLP
GRADIENT TIGHTENS IN ADVANCE OF A SFC TROUGH /COLD FRONT/
APPROACHING FROM THE WEST...AND THIS SHOULD ALLOW RESIDUAL LOW-LEVEL
MOISTURE TO GRADUALLY MIX OUT BY MID/LATE MORNING WITH A POTENTIAL
FOR SUNNY OR MOSTLY SUNNY SKIES IN THE AFTERNOON...ESP WEST OF I-95.
EXPECT HIGHS RANGING FROM THE UPPER 50S TO NEAR 60F IN THE NW
PIEDMONT TO LOWER/MID 60S ELSEWHERE. -VINCENT
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 225 AM SATURDAY...
...RAIN EVENT SUNDAY NIGHT INTO MONDAY...
THE MODELS CONTINUE TO COME INTO A BETTER AGREEMENT ON THE
TIMING/TRACK/STRENGTH OF IMPORTANT FEATURES EXPECTED TO PRODUCE A
SIGNIFICANT RAIN EVENT THIS TIME FOR OUR REGION THIS PERIOD. THE
MID/UPPER TROUGH CURRENTLY OVER THE WESTERN STATES IS FORECAST TO
EJECT EAST INTO THE LOWER MISSISSIPPI VALLEY REGION SUNDAY NIGHT...
THEN INTO THE OHIO VALLEY MONDAY. THE GULF OF MEXICO AND THE WESTERN
ATLANTIC ARE TAPPED INTO THIS SYSTEM AS A WELL DEFINED SURFACE WAVE
TRACKS FROM THE WESTERN GULF OF MEXICO SUNDAY INTO THE LOWER
MISSISSIPPI VALLEY SUNDAY NIGHT... THEN ACROSS GEORGIA AND SOUTHERN
AND EASTERN NORTH CAROLINA MONDAY. AT THE SAME TIME... A COLD HIGH
PRESSURE OVER THE MIDWEST IS FORECAST TO SLOWLY MOVE EAST TOWARD THE
GREAT LAKES AND NEW ENGLAND BY LATE MONDAY. IT CONTINUES TO APPEAR
THAT THIS HIGH WILL NOT BE ABLE TO BUILD FAR ENOUGH SOUTH TO PUSH
COLD ENOUGH AIR INTO NC BEFORE THE MAIN BULK OF THE PRECIPITATION
ENDS LATE MONDAY. HOWEVER... A CAD EVENT IS EXPECTED TO DEVELOP
MONDAY AS MUCH OF OUR REGION SAVE THE SANDHILLS AND SOUTHERN COASTAL
PLAIN WILL LIKELY BE ON THE COOL SIDE OF BOUNDARY AND LOW PRESSURE
TRACK. JUST NOT COOL ENOUGH FOR ANYTHING OTHER THAN A CHILLY RAIN
AND NE FLOW. THEREFORE... SUNDAY NIGHT WILL BRING CLOUDY SKIES WITH
RAIN DEVELOPING. LOWS 35-45 NORTH TO SE. RAIN MONDAY... POSSIBLY
HEAVY IN THE MORNING... TAPERING OFF IN THE LATER AFTERNOON. HIGHS
40-45 NORTH... 50-55 SOUTHEAST.
THE CAD EVENT DRIVEN BY THE FLOW AROUND THE DEPARTING LOW OFFSHORE
AND CHILLY 1030+ MB HIGH PRESSURE OVER NEW ENGLAND MONDAY NIGHT AND
TUESDAY WILL STRENGTHEN. THERE SHOULD BE A LULL IN THE RAIN MONDAY
NIGHT THROUGH TUESDAY MORNING... THEN YET ANOTHER "WET" SYSTEM IS
EXPECTED TO TRACK FROM THE NW GULF OF MEXICO NE THROUGH THE OHIO
VALLEY REGION TUE NIGHT INTO WEDNESDAY. MODELS ALSO SUGGEST A WARM
FRONT WILL TRY TO RETURN INTO OUR CAD OVER THE PIEDMONT TUESDAY AND
TUESDAY NIGHT WITH WAA RAIN EXPECTED TO REDEVELOP OUT AHEAD OF THE
FRONT OVER CENTRAL NC. THIS SHOULD BRING ANOTHER ROUND OF LIGHT TO
MODERATE RAIN WITH QPF ON THE ORDER OF 0.25 TO 0.50 OF AN INCH
TUESDAY AND TUESDAY NIGHT. MONDAY NIGHT... CLOUDY WITH AREAS OF FOG
AND DRIZZLE. LOWS 33-38. TUESDAY... AREAS OF FOG AND DRIZZLE WITH
RAIN LIKELY IN THE AFTERNOON. HIGHS IN THE 38 NW TO 55 SE.
TUESDAY NIGHT AND WEDNESDAY... THE COLD FRONT WILL PUSH THROUGH THE
REGION WEDNESDAY. RESIDUAL CAD SHOULD LINGER IN THE PIEDMONT... WITH
WARMING TO THE SOUTH AND EAST OF THE CAD BOUNDARY WEDNESDAY. RAIN IS
LIKELY THROUGH THE COLD FRONTAL PASSAGE... THEN PARTIAL CLEARING IN
THE WEST LATE. LOWS WED NIGHT GENERALLY 38-50. HIGH WEDNESDAY 50 NW
TO 65-70 SE.
THURSDAY AND FRIDAY... COLD HIGH PRESSURE OVER THE MIDWEST IS
FORECAST TO BUILD INTO NC BEHIND THE COLD FRONT WED NIGHT AND
THURSDAY. DRY AND COOLER WEATHER WILL RETURN. LOWS 25-32. HIGHS
THURSDAY IN THE 40S TO LOWER 50S SE.
FRIDAY... A THIRD WET SYSTEM FOR THE WEEK IS EXPECTED TO BRING MORE
RAIN BY LATER FRIDAY IF NOT BEFORE. TIMING AND DETAILS ARE COMING
TOGETHER FOR A STORM TRACK SIMILAR TO THE TWO PREVIOUS SYSTEMS. A
COLD HIGH TO THE NORTH APPEARS TO BE STRONG ENOUGH AND IN A
FAVORABLE POSITION TO DELIVER COLD DRY AIR INTO OUR REGION BEFORE
THE PRECIPITATION BEGINS. HOWEVER... TAKING A MEAN ENSEMBLE APPROACH
PRODUCES A MILLER TYPE B STORM WITH THE MAIN STORM POSSIBLY TRACKING
JUST TO OUR WEST... AND A NEW STORM DEVELOPMENT OFFSHORE. THIS
SUGGESTS THAT IF THERE ARE P-TYPE ISSUES... THEY WOULD MOST LIKELY
BE FREEZING RAIN/SLEET/RAIN. CURRENT LOW LEVEL THICKNESSES FORECAST
THAT FAR OUT... WITH LOW CONFIDENCE... SUGGEST MOSTLY RAIN... WITH A
CHANCE OF THE PRECIPIATION BEGINNING AS FREEZING RAIN OR SLEET IN
THE TRIAD REGION. FOR NOW... WE WILL CARRY LIQUID... WITH A START
TIME AFTER NOON FRIDAY. THIS SYSTEM HAS THE POTENTIAL TO BRING
FREEZING RAIN/SLEET BUT THE CURRENT MODELS SUGGEST THAT THE HIGH
SHOULD BE PROGRESSIVE ENOUGH IN THAT CAD WOULD BE LIMITED TO HYBRID
AND NOT CLASSICAL (IN WHICH THERE IS A CONTINUOUS SUPPLY OF COLD AIR
INTO THE SYSTEM). THIS WILL OBVIOUSLY BE REFINED AS THESE SYSTEMS
EVOLVE THROUGH THE WEEK.
INC. CLOUDS THURSDAY NIGHT WITH LOWS 30-35. A CHANCE OF RAIN FRIDAY
AFTERNOON. HIGHS 37-45 NW TO SE.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 100 PM SATURDAY...
ON THE STRENGTH OF GOOD 850MB MOISTURE ADVECTION...AREAS OF RAIN
WERE MOVING RAPIDLY ACROSS CENTRAL NORTH CAROLINA THIS AFTERNOON. AS
LOW-LEVEL MOISTURE CONTINUES TO INCREASE...CEILINGS WILL LOWER...
LIKELY DETERIORATING THROUGH MVFR TO IFR IN MOST LOCATIONS THIS
AFTERNOON THROUGH 06Z. LESS CONFIDENT IN HOW LOW CEILINGS AND
VISIBILITIES MAY GET TOWARD THE TRIAD AND FOR THE 18Z VALID TAF
ISSUANCE FORECAST TEMPORARY IFR CONDITIONS LATE TONIGHT AS DRYING
ALOFT TAKES PLACE. BASED ON THE LATEST VISIBLE SATELLITE IMAGE OF
SNOW COVER PRIOR TO THE ONSET OF CLOUDS...THINK THE GREATER
PROBABILITY OF IFR CONDITIONS IN FOG IS MORE TOWARD THE INTERSTATE
95 CORRIDOR AND PARTICULARLY TOWARD KRWI...WITH SOME INCREASING
WINDS JUST OFF THE SURFACE HELPING WITH BETTER...ALBEIT MODEST...
MIXING ELSEWHERE. CEILINGS SHOULD ONLY GRADUALLY INCREASE SUNDAY
MORNING AND TOWARD KFAY AND KRWI CEILINGS COULD BE SOLIDLY LOW MVFR
EVEN AT THE END OF THE 18Z VALID TAF PERIOD. WINDS OFF OF THE
SURFACE NEAR 2000FT WILL INCREASE TO SOUTHWEST AROUND 25KT OVERNIGHT
THROUGH SUNDAY MORNING...THOUGH NOT STRONG ENOUGH FOR LLWS.
BEYOND THE 18Z VALID TAF PERIOD...VFR CONDITIONS SHOULD EVENTUALLY
PREVAIL SUNDAY AFTERNOON...THEN A SURFACE FRONT MOVES INTO THE AREA
AND STALLS FOR A TIME...WITH SUB-VFR CONDITIONS AND THE LIKELIHOOD
OF RAIN BY MONDAY MORNING. THOUGH THE CHANCES FOR RAIN DIMINISH...
SUB-VFR CONDITIONS...WITH SEVERAL PERIODS OF IFR...SHOULD CONTINUE
INTO THE DAY WEDNESDAY...WITH ANOTHER PERIOD OF RAIN LIKELY TUESDAY
INTO WEDNESDAY AFTERNOON. FINALLY...WEDNESDAY NIGHT...THE
PROBABILITY OF CONDITIONS RETURNING TO VFR INCREASE. VFR CONDITIONS
ARE EXPECTED FOR THURSDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF/VINCENT
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
951 AM EST SAT FEB 1 2014
.SYNOPSIS...SURFACE HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY.
MEANWHILE...WEAK LOW PRESSURE WILL DEVELOP OFF THE CAROLINA COAST
TODAY...MOVING NORTHEAST ON SUNDAY. STRONGER LOW PRESSURE WILL TRACK
NORTHEAST ACROSS THE CAROLINAS MONDAY. A COLD FRONT SURGES SOUTH
INTO THE CAROLINAS LATE MONDAY AND MONDAY NIGHT.
&&
.NEAR TERM /THIS AFTERNOON AND TONIGHT/...
AS OF 950 AM SATURDAY...
WHILE SURFACE HIGH PRESSURE REMAINED OVER CENTRAL NORTH CAROLINA...
MOISTURE ADVECTION WAS TAKING PLACE FROM THE SOUTH. ALREADY ON THE
12Z UPPER-AIR SOUNDING AT KMHX...THERE WAS A NARROW LAYER OF GOOD
MOISTURE JUST BELOW 850MB...AND THE 12Z 850MB ANALYSIS SHOWED DEW
POINTS AT THAT LEVEL NEAR 10C INTO SOUTH CAROLINA. LIGHT
PRECIPITATION WAS NOTED ON REGIONAL RADAR RETURNS SOUTH OF CENTRAL
NORTH CAROLINA WITHIN A COUNTY OF THE BORDER...AND DURING THE
AFTERNOON THE RAP FORECASTS CONTINUED 850MB THETA-E ADVECTION INTO
THE AREA AS 850MB WINDS INCREASE TO 30 TO 35KT LATE IN THE DAY.
DIFFLUENCE ALOFT IS FORECAST TO BE WEAK...COINCIDENT WITH THE UPPER-
LEVEL STEADY SOUTHWEST FLOW OVER THE AREA...BUT IT SHOULD BE ENOUGH
WITH LOW-LEVEL MOISTENING AND JUST A LITTLE INSTABILITY TO RESULT IN
A CONTINUED NORTHWARD PROGRESSION OF AREAS OF LIGHT RAIN THIS
AFTERNOON INTO THIS EVENING. JUST BELOW THE INVERSION AROUND 700MB
THERE IS FORECAST LAYER MUCAPE AROUND 100J/KG...WHICH SHOULD HELP
SUPPORT THE AREAS OF RAIN AND POSSIBLY MAKE THE PRECIPITATION
SHOWERY AT TIMES ESPECIALLY EAST OF U.S. 1. RAP SOUNDINGS SHOWING A
CAP THROUGH THE EVENING JUST ABOVE 700MB SHOULD PRECLUDE ANY DEEP
CONVECTION. ADJUSTED THE TIMING OF PRECIPITATION JUST A LITTLE
FASTER ESPECIALLY OVER THE SANDHILLS... AND LEFT TEMPERATURES AS
PREVIOUSLY FORECAST AS THE RAPID PROGRESSION OF THE CLOUDS NORTH
COULD KEEP MAXES FROM REACHING POTENTIAL HIGHS WELL INTO THE 50S
BASED SIMPLY ON 1000-850MB THICKNESSES.
TONIGHT...THE BULK OF MODEL GUIDANCE SHOWS 0.03-0.08" OF MEASURABLE
PRECIP ACROSS CENTRAL NC...WITH THE RELATIVE HIGHEST AMOUNTS
ALONG/EAST OF HWY 1 WHERE THE SLIGHT ELEVATED INSTABILITY IS
FORECAST TO BE MARGINALLY GREATER ON THE RAP RELATIVE TO THE REST OF
CENTRAL NORTH CAROLINA. EXPECT THE AREAS OF LIGHT RAIN TO END FROM
WEST-EAST SHORTLY AFTER MIDNIGHT (BY ~06Z)...PERHAPS LINGERING AS
LATE AS 06-09Z IN THE COASTAL PLAIN. THIS IS VERY CLOSE TO WHAT THE
00Z HIGH RES WRF-NMM SIM REF PRODUCT SUGGESTS...WHICH SEEMS
REASONABLE. LOWS TONIGHT WILL BE RELATIVELY BALMY IN COMPARISON TO
PREVIOUS NIGHTS DUE TO PERVASIVE CLOUD COVER (THOUGH PERHAPS ERODING
IN THE WESTERN PIEDMONT NEAR SUNRISE SUN)...RANGING FROM THE UPPER
30S NW TO LOWER/MID 40S SE.
IN TERMS OF THE DENSE FOG POTENTIAL...TOP-DOWN DRYING WILL RAPIDLY
OCCUR AFTER MIDNIGHT AS LOW-LEVEL FLOW VEERS TO THE WSW AND ADVECTS
A DRIER AIRMASS INTO CENTRAL NC...ESPECIALLY IN THE FAR N/NW
PIEDMONT. THE MSLP GRADIENT WILL REMAIN VERY WEAK SUN MORNING...WITH
LITTLE SFC ADVECTION AND A HIGH LIKELIHOOD THAT SHALLOW SATURATION
(MOST SHALLOW IN NORTHERN/WESTERN PIEDMONT) WILL PERSIST THROUGH
SUNRISE. IF SUFFICIENT TOP-DOWN DRYING OCCURS PRIOR TO SUNRISE IT IS
POSSIBLE THAT DENSE FOG COULD DEVELOP ACROSS THE AREA. LATER
FORECASTS MAY NEED TO INTRODUCE AGAIN AT LEAST PATCHY FOG EAST
PARTICULARLY INTO THE COASTAL PLAIN...WHERE LINGERING SNOW COVER AND
COOL GROUND BELOW INCREASING MOISTURE MAY MAKE SUCH CONDITIONS AS
LEAST AS LIKELY AS ELSEWHERE.
&&
.SHORT TERM /SUNDAY/...
AS OF 330 AM SATURDAY...
SOUTHWEST FLOW WILL INCREASE DURING THE DAY SUNDAY AS THE MSLP
GRADIENT TIGHTENS IN ADVANCE OF A SFC TROUGH /COLD FRONT/
APPROACHING FROM THE WEST...AND THIS SHOULD ALLOW RESIDUAL LOW-LEVEL
MOISTURE TO GRADUALLY MIX OUT BY MID/LATE MORNING WITH A POTENTIAL
FOR SUNNY OR MOSTLY SUNNY SKIES IN THE AFTERNOON...ESP WEST OF I-95.
EXPECT HIGHS RANGING FROM THE UPPER 50S TO NEAR 60F IN THE NW
PIEDMONT TO LOWER/MID 60S ELSEWHERE. -VINCENT
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 225 AM SATURDAY...
...RAIN EVENT SUNDAY NIGHT INTO MONDAY...
THE MODELS CONTINUE TO COME INTO A BETTER AGREEMENT ON THE
TIMING/TRACK/STRENGTH OF IMPORTANT FEATURES EXPECTED TO PRODUCE A
SIGNIFICANT RAIN EVENT THIS TIME FOR OUR REGION THIS PERIOD. THE
MID/UPPER TROUGH CURRENTLY OVER THE WESTERN STATES IS FORECAST TO
EJECT EAST INTO THE LOWER MISSISSIPPI VALLEY REGION SUNDAY NIGHT...
THEN INTO THE OHIO VALLEY MONDAY. THE GULF OF MEXICO AND THE WESTERN
ATLANTIC ARE TAPPED INTO THIS SYSTEM AS A WELL DEFINED SURFACE WAVE
TRACKS FROM THE WESTERN GULF OF MEXICO SUNDAY INTO THE LOWER
MISSISSIPPI VALLEY SUNDAY NIGHT... THEN ACROSS GEORGIA AND SOUTHERN
AND EASTERN NORTH CAROLINA MONDAY. AT THE SAME TIME... A COLD HIGH
PRESSURE OVER THE MIDWEST IS FORECAST TO SLOWLY MOVE EAST TOWARD THE
GREAT LAKES AND NEW ENGLAND BY LATE MONDAY. IT CONTINUES TO APPEAR
THAT THIS HIGH WILL NOT BE ABLE TO BUILD FAR ENOUGH SOUTH TO PUSH
COLD ENOUGH AIR INTO NC BEFORE THE MAIN BULK OF THE PRECIPITATION
ENDS LATE MONDAY. HOWEVER... A CAD EVENT IS EXPECTED TO DEVELOP
MONDAY AS MUCH OF OUR REGION SAVE THE SANDHILLS AND SOUTHERN COASTAL
PLAIN WILL LIKELY BE ON THE COOL SIDE OF BOUNDARY AND LOW PRESSURE
TRACK. JUST NOT COOL ENOUGH FOR ANYTHING OTHER THAN A CHILLY RAIN
AND NE FLOW. THEREFORE... SUNDAY NIGHT WILL BRING CLOUDY SKIES WITH
RAIN DEVELOPING. LOWS 35-45 NORTH TO SE. RAIN MONDAY... POSSIBLY
HEAVY IN THE MORNING... TAPERING OFF IN THE LATER AFTERNOON. HIGHS
40-45 NORTH... 50-55 SOUTHEAST.
THE CAD EVENT DRIVEN BY THE FLOW AROUND THE DEPARTING LOW OFFSHORE
AND CHILLY 1030+ MB HIGH PRESSURE OVER NEW ENGLAND MONDAY NIGHT AND
TUESDAY WILL STRENGTHEN. THERE SHOULD BE A LULL IN THE RAIN MONDAY
NIGHT THROUGH TUESDAY MORNING... THEN YET ANOTHER "WET" SYSTEM IS
EXPECTED TO TRACK FROM THE NW GULF OF MEXICO NE THROUGH THE OHIO
VALLEY REGION TUE NIGHT INTO WEDNESDAY. MODELS ALSO SUGGEST A WARM
FRONT WILL TRY TO RETURN INTO OUR CAD OVER THE PIEDMONT TUESDAY AND
TUESDAY NIGHT WITH WAA RAIN EXPECTED TO REDEVELOP OUT AHEAD OF THE
FRONT OVER CENTRAL NC. THIS SHOULD BRING ANOTHER ROUND OF LIGHT TO
MODERATE RAIN WITH QPF ON THE ORDER OF 0.25 TO 0.50 OF AN INCH
TUESDAY AND TUESDAY NIGHT. MONDAY NIGHT... CLOUDY WITH AREAS OF FOG
AND DRIZZLE. LOWS 33-38. TUESDAY... AREAS OF FOG AND DRIZZLE WITH
RAIN LIKELY IN THE AFTERNOON. HIGHS IN THE 38 NW TO 55 SE.
TUESDAY NIGHT AND WEDNESDAY... THE COLD FRONT WILL PUSH THROUGH THE
REGION WEDNESDAY. RESIDUAL CAD SHOULD LINGER IN THE PIEDMONT... WITH
WARMING TO THE SOUTH AND EAST OF THE CAD BOUNDARY WEDNESDAY. RAIN IS
LIKELY THROUGH THE COLD FRONTAL PASSAGE... THEN PARTIAL CLEARING IN
THE WEST LATE. LOWS WED NIGHT GENERALLY 38-50. HIGH WEDNESDAY 50 NW
TO 65-70 SE.
THURSDAY AND FRIDAY... COLD HIGH PRESSURE OVER THE MIDWEST IS
FORECAST TO BUILD INTO NC BEHIND THE COLD FRONT WED NIGHT AND
THURSDAY. DRY AND COOLER WEATHER WILL RETURN. LOWS 25-32. HIGHS
THURSDAY IN THE 40S TO LOWER 50S SE.
FRIDAY... A THIRD WET SYSTEM FOR THE WEEK IS EXPECTED TO BRING MORE
RAIN BY LATER FRIDAY IF NOT BEFORE. TIMING AND DETAILS ARE COMING
TOGETHER FOR A STORM TRACK SIMILAR TO THE TWO PREVIOUS SYSTEMS. A
COLD HIGH TO THE NORTH APPEARS TO BE STRONG ENOUGH AND IN A
FAVORABLE POSITION TO DELIVER COLD DRY AIR INTO OUR REGION BEFORE
THE PRECIPITATION BEGINS. HOWEVER... TAKING A MEAN ENSEMBLE APPROACH
PRODUCES A MILLER TYPE B STORM WITH THE MAIN STORM POSSIBLY TRACKING
JUST TO OUR WEST... AND A NEW STORM DEVELOPMENT OFFSHORE. THIS
SUGGESTS THAT IF THERE ARE P-TYPE ISSUES... THEY WOULD MOST LIKELY
BE FREEZING RAIN/SLEET/RAIN. CURRENT LOW LEVEL THICKNESSES FORECAST
THAT FAR OUT... WITH LOW CONFIDENCE... SUGGEST MOSTLY RAIN... WITH A
CHANCE OF THE PRECIPIATION BEGINNING AS FREEZING RAIN OR SLEET IN
THE TRIAD REGION. FOR NOW... WE WILL CARRY LIQUID... WITH A START
TIME AFTER NOON FRIDAY. THIS SYSTEM HAS THE POTENTIAL TO BRING
FREEZING RAIN/SLEET BUT THE CURRENT MODELS SUGGEST THAT THE HIGH
SHOULD BE PROGRESSIVE ENOUGH IN THAT CAD WOULD BE LIMITED TO HYBRID
AND NOT CLASSICAL (IN WHICH THERE IS A CONTINUOUS SUPPLY OF COLD AIR
INTO THE SYSTEM). THIS WILL OBVIOUSLY BE REFINED AS THESE SYSTEMS
EVOLVE THROUGH THE WEEK.
INC. CLOUDS THURSDAY NIGHT WITH LOWS 30-35. A CHANCE OF RAIN FRIDAY
AFTERNOON. HIGHS 37-45 NW TO SE.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AS OF 950 AM SATURDAY...
24-HR TAF PERIOD: VFR CEILINGS ADVECT NORTH INTO CENTRAL NC THROUGH
THE AFTERNOON...WITH CEILINGS LOWERING TO MVFR (1500-2500 FT AGL)
FROM SOUTH-NORTH BY OR SHORTLY AFTER 21Z. THEREAFTER...WARM
ADVECTION WILL RAPIDLY STRENGTHEN OVER CENTRAL NC AND CEILINGS ARE
EXPECTED TO LOWER TO IFR (700-1200 FT AGL) AT ALL TERMINALS BY 00-
03Z...WITH PERIODS OF LIGHT RAIN POSSIBLE. THE BEST CHANCE FOR RAIN
WILL OCCUR BETWEEN 00-06Z...PRIMARILY AT THE RDU/FAY/RWI TERMINALS.
THOUGH TOP-DOWN DRYING WILL OCCUR AFTER MIDNIGHT AS LOW-LEVEL FLOW
VEERS TO THE WSW...MOISTURE WILL PERSIST IN THE SFC-925 MB LAYER AND
IT SEEMS LIKELY THAT CEILINGS WILL GRADUALLY LOWER TO LIFR AND/OR
THAT DENSE FOG WILL DEVELOP BETWEEN 06-12Z SUN.
LOOKING AHEAD: A 10-15 KT SOUTHWEST BREEZE DEVELOPING MID/LATE
SUNDAY MORNING IN ADVANCE OF AN APPROACHING SFC TROUGH SHOULD ALLOW
LINGERING SHALLOW MOISTURE TO MIX OUT WITH VFR CONDITIONS RETURNING
BY 15-18Z...ESPECIALLY AT THE INT/GSO/RDU TERMINALS. FURTHER EAST AT
THE RWI/FAY TERMINALS IT WILL TAKE SEVERAL HOURS LONGER FOR SHALLOW
MOISTURE TO MIX OUT...AND IT IS POSSIBLE THAT BROKEN MVFR CEILINGS
LINGER WELL INTO THE AFTERNOON. CONDITIONS WILL DETERIORATE TO
MVFR/IFR EVERYWHERE SUNDAY NIGHT WITH LIFR CONDITIONS AND RAIN
DURING THE DAY MONDAY AS THE LOW TRACKS NE ACROSS CENTRAL OR
SOUTHEAST PORTIONS OF THE CAROLINAS. BEFORE ANY IMPROVEMENT
OCCURS...ANOTHER LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE GULF
COAST AND TRACK NE THROUGH THE TN VALLEY ON TUE/WED...WITH A STRONG
COLD AIR DAMMING WEDGE DEVELOPING EAST OF THE MTNS AND WIDESPREAD
ADVERSE AVIATION CONDITIONS PERSISTING OVER CENTRAL NC THROUGH WED
AFTERNOON...FOLLOWED BY BREEZY NW/NNW WINDS AND A RAPID RETURN TO
VFR CONDITIONS IN THE WAKE OF AN ARCTIC COLD FRONTAL PASSAGE LATE
WED/WED NIGHT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF/VINCENT
NEAR TERM...DJF/VINCENT
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
953 PM CST SUN FEB 2 2014
.UPDATE...
ISSUED AT 952 PM CST SUN FEB 2 2014
NO CHANGES FROM PREVIOUS UPDATE...EXPECT COLDEST READINGS IN
SOUTHEAST BEFORE CLOUDS MOVE IN LATER TONIGHT.
UPDATE ISSUED AT 615 PM CST SUN FEB 2 2014
A COLD FRONT WILL MOVE THROUGH THE REGION OVERNIGHT...ALTHOUGH
MOST OF THE COOLING IS ALOFT. THERE ARE ALSO PLENTY OF CLOUDS THAT
WILL MOVE FROM WEST TO EAST OVERNIGHT...SO SIMILAR TO LAST
NIGHT...LOWS COULD BE EARLY AND COLDEST EAST WHERE IT WILL BE
CLEARER LONGER. WE WILL TWEAK TEMPS UP A FEW DEGREES FOR MOST
AREAS...WITH TEMPS LIKELY WITHIN A FEW DEGREES OF ZERO AT LEAST IN
ND OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 328 PM CST SUN FEB 2 2014
MAIN CHALLENGE THROUGH THE PERIOD WILL BE TEMPERATURES AND CLOUD
COVER. GFS/NAM/ECMWF/GEM SYNOPTIC PATTERN IN GOOD AGREEMENT AND
WILL USE A BLENDED SOLUTION FOR THIS FORECAST PACKAGE.
21 UTC SURFACE ANALYSIS SHOWS A SURFACE TROUGH AXIS FROM DEVILS
LAKE TO BISMARCK WITH A COLD FRONT DRAPED FROM WILLISTON TO
DICKINSON. OVERCAST SKIES UPSTREAM FROM THE FRONT ACROSS NORTHEAST
MT INTO SASKATCHEWAN NOT WELL RESOLVED IN GLOBAL MODELS...BOTH
SHOWING CLOUDS BREAKING UP AS THEY MOVE EAST. SATELLITE IMAGERY
SHOWS FEW BREAKS AND WITH SURFACE RIDGE AXIS ESTABLISHING ITSELF
ACROSS THE FORECAST AREA OVERNIGHT...SEE NO REASON CLOUDS WILL
COMPLETELY DISSIPATE. WILL FOLLOW RAP 925 HPA RH OUTPUT WHICH
MOVES LOW CLOUDS ACROSS THE REGION THIS EVENING AND OVERNIGHT FOR
AT LEAST PARTLY CLOUDY SKIES. AS A RESULT...INCREASED CLOUD COVER
AND LOW TEMPERATURES TONIGHT DESPITE LOW-LEVEL COLD AIR ADVECTION
BEHIND THE FRONT. EXACT TEMPERATURES WILL DEPEND ON CLOUD COVER...
BUT STILL THINK MOST AREAS SHOULD DROP BELOW ZERO. NO NEED FOR
WIND CHILL HEADLINES TONIGHT WITH LIGHT WIND AROUND 5 TO 10 MPH.
MONDAY WILL SEE A MIX OF CLOUDS AND SUN WITH TEMPERATURES 5 TO 10
DEGREES COOLER THAN TODAY. LIGHT WEST-NORTHWEST FLOW WILL SHIFT TO
A MORE NORTHERLY DIRECTION AS 1040 HPA PLUS SURFACE HIGH TAKES UP
RESIDENCE ACROSS THE NORTHERN ROCKIES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 328 PM CST SUN FEB 2 2014
STORM TRACK TUESDAY/WEDNESDAY WILL REMAIN WELL SOUTH OF THE
FORECAST AREA WITH DRY NORTHERLY FLOW ACROSS THE NORTHERN PLAINS.
TEMPERATURES...HOWEVER...WILL CONTINUE TO BE 10 TO 20 DEGREES
BELOW EARLY FEBRUARY NORMALS UNDER PERSISTENT COLD AIR ADVECTION
REGIME. AFTERNOON HIGHS BOTH DAYS LIKELY TO BE WITHIN A FEW
DEGREES PLUS OR MINUS THE ZERO MARK WITH NIGHTTIME LOWS DIPPING
WELL INTO THE MID TEENS BELOW ZERO AND POSSIBLY COLDER ONCE AGAIN
INCREASING THE SEEMINGLY ENDLESS WIND CHILL THREAT.
WEDNESDAY NIGHT THROUGH SUNDAY...LITTLE CHANGE EXPECTED THROUGH THE
REMAINDER OF THE WORK WEEK. WEDGE OF SURFACE HIGH PRESSURE WILL
KEEP REGION DRY ALONG WITH TEMPERATURES CONTINUING WELL BLO AVERAGE.
MODELS DIVERGE NEXT WEEKEND ON SOLUTIONS BUT OVERALL LOOKS LIKE
STORM TRACK WILL REMAIN TO OUR SOUTH WITH FA REMAINING DRY BUT BLO
AVERAGE TEMPERATURES PERSISTING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 615 PM CST SUN FEB 2 2014
THERE WILL BE INCREASING VFR/MVFR CIGS OVERNIGHT INTO MONDAY
MORNING. WINDS WILL ALSO SHIFT MORE NORTHWESTERLY BEHIND THE SFC
BOUNDARY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...ROGERS
LONG TERM...ROGERS/VOELKER
AVIATION...DK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
616 PM CST SUN FEB 2 2014
.UPDATE...
ISSUED AT 615 PM CST SUN FEB 2 2014
A COLD FRONT WILL MOVE THROUGH THE REGION OVERNIGHT...ALTHOUGH
MOST OF THE COOLING IS ALOFT. THERE ARE ALSO PLENTY OF CLOUDS THAT
WILL MOVE FROM WEST TO EAST OVERNIGHT...SO SIMILAR TO LAST
NIGHT...LOWS COULD BE EARLY AND COLDEST EAST WHERE IT WILL BE
CLEARER LONGER. WE WILL TWEAK TEMPS UP A FEW DEGREES FOR MOST
AREAS...WITH TEMPS LIKELY WITHIN A FEW DEGREES OF ZERO AT LEAST IN
ND OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 328 PM CST SUN FEB 2 2014
MAIN CHALLENGE THROUGH THE PERIOD WILL BE TEMPERATURES AND CLOUD
COVER. GFS/NAM/ECMWF/GEM SYNOPTIC PATTERN IN GOOD AGREEMENT AND
WILL USE A BLENDED SOLUTION FOR THIS FORECAST PACKAGE.
21 UTC SURFACE ANALYSIS SHOWS A SURFACE TROUGH AXIS FROM DEVILS
LAKE TO BISMARCK WITH A COLD FRONT DRAPED FROM WILLISTON TO
DICKINSON. OVERCAST SKIES UPSTREAM FROM THE FRONT ACROSS NORTHEAST
MT INTO SASKATCHEWAN NOT WELL RESOLVED IN GLOBAL MODELS...BOTH
SHOWING CLOUDS BREAKING UP AS THEY MOVE EAST. SATELLITE IMAGERY
SHOWS FEW BREAKS AND WITH SURFACE RIDGE AXIS ESTABLISHING ITSELF
ACROSS THE FORECAST AREA OVERNIGHT...SEE NO REASON CLOUDS WILL
COMPLETELY DISSIPATE. WILL FOLLOW RAP 925 HPA RH OUTPUT WHICH
MOVES LOW CLOUDS ACROSS THE REGION THIS EVENING AND OVERNIGHT FOR
AT LEAST PARTLY CLOUDY SKIES. AS A RESULT...INCREASED CLOUD COVER
AND LOW TEMPERATURES TONIGHT DESPITE LOW-LEVEL COLD AIR ADVECTION
BEHIND THE FRONT. EXACT TEMPERATURES WILL DEPEND ON CLOUD COVER...
BUT STILL THINK MOST AREAS SHOULD DROP BELOW ZERO. NO NEED FOR
WIND CHILL HEADLINES TONIGHT WITH LIGHT WIND AROUND 5 TO 10 MPH.
MONDAY WILL SEE A MIX OF CLOUDS AND SUN WITH TEMPERATURES 5 TO 10
DEGREES COOLER THAN TODAY. LIGHT WEST-NORTHWEST FLOW WILL SHIFT TO
A MORE NORTHERLY DIRECTION AS 1040 HPA PLUS SURFACE HIGH TAKES UP
RESIDENCE ACROSS THE NORTHERN ROCKIES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 328 PM CST SUN FEB 2 2014
STORM TRACK TUESDAY/WEDNESDAY WILL REMAIN WELL SOUTH OF THE
FORECAST AREA WITH DRY NORTHERLY FLOW ACROSS THE NORTHERN PLAINS.
TEMPERATURES...HOWEVER...WILL CONTINUE TO BE 10 TO 20 DEGREES
BELOW EARLY FEBRUARY NORMALS UNDER PERSISTENT COLD AIR ADVECTION
REGIME. AFTERNOON HIGHS BOTH DAYS LIKELY TO BE WITHIN A FEW
DEGREES PLUS OR MINUS THE ZERO MARK WITH NIGHTTIME LOWS DIPPING
WELL INTO THE MID TEENS BELOW ZERO AND POSSIBLY COLDER ONCE AGAIN
INCREASING THE SEEMINGLY ENDLESS WIND CHILL THREAT.
WEDNESDAY NIGHT THROUGH SUNDAY...LITTLE CHANGE EXPECTED THROUGH THE
REMAINDER OF THE WORK WEEK. WEDGE OF SURFACE HIGH PRESSURE WILL
KEEP REGION DRY ALONG WITH TEMPERATURES CONTINUING WELL BLO AVERAGE.
MODELS DIVERGE NEXT WEEKEND ON SOLUTIONS BUT OVERALL LOOKS LIKE
STORM TRACK WILL REMAIN TO OUR SOUTH WITH FA REMAINING DRY BUT BLO
AVERAGE TEMPERATURES PERSISTING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 615 PM CST SUN FEB 2 2014
THERE WILL BE INCREASING VFR/MVFR CIGS OVERNIGHT INTO MONDAY
MORNING. WINDS WILL ALSO SHIFT MORE NORTHWESTERLY BEHIND THE SFC
BOUNDARY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...ROGERS
LONG TERM...ROGERS/VOELKER
AVIATION...DK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1248 AM CST SAT FEB 1 2014
.UPDATE...
ISSUED AT 1248 AM CST SAT FEB 1 2014
THE SURFACE TROUGH AXIS/WEAK COLD FRONT HAS CLEARED ALL OF WESTERN
AND CENTRAL NORTH DAKOTA MINUS THE SOUTHERN PORTIONS OF THE JAMES
RIVER VALLEY. COULD SEE A FEW FLURRIES FROM THE STRATUS IN COLD
AIR ADVECTION THROUGH THE NIGHT BEHIND THE FRONT...HOWEVER...LEFT
IT FOR THE MOST PART OUT OF THE GRIDS FOR NOW. FORECAST BLENDED
TO THE 05-06 UTC OBSERVED TRENDS.
UPDATE ISSUED AT 947 PM CST FRI JAN 31 2014
A SURFACE TROUGH AXIS CONTINUES TO PUSH EAST ACROSS THE STATE
LATE THIS EVENING. SUSTAINED WINDS IN MINOT WERE 24 KNOTS AT
0254Z. NONE OF THE SHORT-TERM MODEL GUIDANCE HAS CAPTURED JUST HOW
STRONG WINDS ARE BEHIND THE FRONT. AS A RESULT...UPDATED THE
FORECAST TO INCREASE WINDS BY A FEW MPH IMMEDIATELY BEHIND THE
FRONT TONIGHT BASED ON CURRENT OBS/TRENDS. THE REMAINING WEATHER
ELEMENTS ARE IN GOOD SHAPE. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 650 PM CST FRI JAN 31 2014
A SURFACE TROUGH AXIS HAS JUST ENTERED NORTHWESTERN NORTH DAKOTA
THIS EVENING. WINDS GUSTED TO 24 KNOTS WITH LIGHT FLURRIES AND
LOWERING CEILINGS AT WILLISTON AT 0017Z. THIS BOUNDARY WILL
CONTINUE TO PUSH EAST ACROSS THE STATE TONIGHT...GENERATING
BRIEF WIND GUSTS AROUND 25 KNOTS AND SCATTERED FLURRIES IN THE
WAKE OF THE BOUNDARY. THE CURRENT FORECAST IS ON TRACK WITH NO
MAJOR UPDATES REQUIRED. WIND CHILLS STILL APPEAR TO BE ON TRACK TO
REMAIN ABOVE 25 DEGREES BELOW ZERO TONIGHT...SO WILL NOT BE
ISSUING ANY HEADLINES FOR THIS UPDATE. THE UPDATED PRODUCTS HAVE
BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 204 PM CST FRI JAN 31 2014
THE MAIN FORECAST ISSUE IN THE NEAR TERM PERIOD IS THE COLD
FRONTAL PASSAGE TONIGHT AND CONSIDERATION OF WIND CHILL HEADLINES.
RECENT OBS AND RADAR TRENDS INDICATE A NARROW BAND OF WEAK
REFLECTIVITY ALONG A COLD FRONT THAT HAS PUSHED INTO SOUTHERN
SASKATCHEWAN. THIS FRONT WILL CONTINUE TO PUSH SOUTHEAST THROUGH
THE FORECAST AREA TONIGHT. HI-RES MODELS SUCH AS THE HRRR AND 13KM
RAP ARE INDICATING SOME VERY LIGHT QPF. WILL MENTION SCATTERED
FLURRIES TONIGHT...TRENDING FROM THE NORTH THIS EVENING INTO THE
JAMES RIVER VALLEY LATE. NO ACCUMULATION IS EXPECTED. CLOUDS AND A
NORTHWEST WIND AT 10-15 MPH ARE EXPECTED TO KEEP TEMPS FROM
BOTTOMING OUT IN THE NORTH. AM EXPECTING WIND CHILLS OF 20 TO 25
BELOW ZERO IN THE NORTHERN TWO TIERS OF COUNTIES...NOT QUITE COLD
ENOUGH FOR AN ADVISORY. ON SATURDAY...DAYTIME TEMPERATURES ARE
ONLY EXPECTED TO RISE SLIGHTLY FROM THE MORNING LOWS AS THE COLD
POCKET SETTLES OVER NORTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 204 PM CST FRI JAN 31 2014
SATURDAY NIGHT THROUGH FRIDAY...
SUCCESSIVE POCKETS OF COLD AIR/SHORTWAVES ROTATE THROUGH THE
PERSISTENT NORTHWEST FLOW ALOFT INTO NORTH DAKOTA. THE MAIN
HIGHLIGHT WILL BE THE COLD AIR WITH WIND CHILL HIGHLIGHTS LIKELY
HOISTED EACH NIGHT THROUGH THE LATE MORNING THROUGH THE EXTENDED PERIOD.
WIND CHILL ADVISORY CRITERIA LOOKS MORE LIKELY IN THE NORTH CENTRAL
AND EAST CENTRAL NORTH DAKOTA. WEDNESDAY MORNING AND THURSDAY
MORNING...WIND CHILL ADVISORY APPEARS MOST WIDESPREAD COVERING ALL
OF WESTERN AND CENTRAL NORTH DAKOTA. IT IS DURING THIS TIME THE
COLDEST SURGE OF H85 TEMPS ARRIVE...BETWEEN -24C TO -27C. WITH THAT
SAID...AFTER COLLABORATING WITH BILLINGS AND RAPID CITY...UNDERCUT
THE ALLBLEND LOW TEMPERATURES BY A FEW DEGREES TUESDAY THROUGH
THURSDAY MORNING. THERE COULD BE A LITTLE LIGHT SNOW IN THE FAR
SOUTHWEST MONDAY NIGHT INTO TUESDAY MORNING PRECEDING THE
AFOREMENTIONED SURGE OF FRIGID AIR. ELSEWHERE...COLD/FRIGID AIR
DOMINATES WITH DRY CONDITIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1248 AM CST SAT FEB 1 2014
AS OF 06 UTC...A COLD FRONT WAS LOCATED FROM KHCO THROUGH KJMS TO
KPIR. MVFR STRATUS WILL IMPACT WESTERN AND CENTRAL NORTH DAKOTA
TONIGHT THROUGH SATURDAY BEHIND THE FRONT. NORTHWEST WIND GUSTS OF
25-30 KTS ARE POSSIBLE TONIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...RP KINNEY
LONG TERM...KS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
829 PM EST SUN FEB 2 2014
.SYNOPSIS...
HIGH PRESSURE BUILDING IN THE UPPER MIDWEST WILL TRACK EAST THROUGH
THE LOWER GREAT LAKES REGION TONIGHT AND MONDAY PUSHING COLDER AIR
ON NORTH WINDS INTO THE OHIO VALLEY. AT THE SAME TIME...LOW
PRESSURE MOVING NORTHEAST FROM THE GULF STATES TO THE MID ATLANTIC
WILL PUSH A DEEP LAYER OF MOISTURE OVER THE COLD AIR...RESULTING
IN SNOW FOR MUCH OF KENTUCKY AND PORTIONS OF SOUTHERN OHIO AND
SOUTHEAST INDIANA TONIGHT. ANOTHER VIGOROUS LOW WILL TAKE AIM ON
THE REGION LATE TUESDAY INTO EARLY WEDNESDAY WITH A WINTRY MIX OF
PRECIPITATION LIKELY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
HAVE BEEN GETTING REPORTS OF SLEET IN THE FAR SOUTHEASTERN
COUNTIES. BASED ON RADAR AND SPOTTER REPORTS IT APPEARS THAT THIS
IS MOVING OFF TO THE EAST. THEREAFTER EVENT SHOULD BE ALL SNOW.
RECENT HRRR AND RAP RUNS ARE IN VERY GOOD AGREEMENT WITH THE SHARP
NORTHERN EDGE OF SNOW BISECTING THE FORECAST AREA FROM SOUTHWEST
TO NORTHEAST. PRECIPITATION AMOUNTS LOOK A BIT HEAVIER ESPECIALLY
IN THE FAR SOUTHEAST COUNTIES. HAVE BUMPED UP ACCUMULATIONS
SLIGHTLY. WARNING AREA STILL LOOKS GOOD. BUT OPTED TO ADD A FEW
COUNTIES TO THE ADVISORY. SNOW SHOULD START PULLING OUT RATHER
QUICKLY AFTER 09Z.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
ANY LINGERING SNOW AT DAYBREAK WILL QUICKLY DROP OFF TO NOTHING
DURING THE MORNING COMMUTE AS THE H5 S/W CROSSES THE REGION AND
FORCES IN DOWNWARD MOTION AND SUBSEQUENT DRIER AIR TO THE SOUTHERN
CWA AS IT PASSES. CLOUD COVER WILL ALSO QUICKLY WANE BUT THE
NORTHERLY FLOW WILL HAMPER ANY STRONG TEMPERATURE RECOVERIES. HAVE
DROPPED HIGHS IN THE SOUTHEAST 3-4 DEGREES WITH THE FRESH SNOWPACK
LIMITING VALUES FROM REACHING PAST FREEZING DURING THE DAY.
AS THE SURFACE HIGH MOVES EAST...TEMPERATURES IN THE TEENS WILL
OCCUR FOR THE REGION MONDAY NIGHT. AM SLIGHTLY CONCERNED THAT
TUESDAY HIGH TEMPERATURES WILL NEED TO BE ADJUSTED DOWNWARD WITH
INCREASING CLOUD COVER AND NORTHEAST WINDS AHEAD OF THE NEXT LOW.
TUESDAY AFTERNOON WILL SEE THE NEXT LOW TRACK TOWARDS THE AREA AND
IT HAS A BIT MORE UPPER LEVEL SUPPORT WITH A STRONGER H5 S/W
LIFTING NORTHEAST THROUGH THE OHIO VALLEY WITH THE TUESDAY STORM.
NAM CONTINUES TO BE MUCH FURTHER NORTH THAN OTHER MODELS AND DRIES
IT OUT SIGNIFICANTLY AFTER A MUCH BRIEFER PERIOD OF PRECIPITATION
THAN OTHER MODELS ARE SHOWING. WOULD TYPICALLY DISCOUNT THIS AND
FAVOR THE GFS/EURO/CANADIAN BLEND WHICH ARE ALL VERY SIMILAR. A
SIMILAR SITUATION ABOUT A MONTH AGO CREATED LITTLE TO NO SNOW
WHERE WARNINGS WERE POSTED WITH HASTE. AM LETTING A TREND DEVELOP
WITH THE TUESDAY STORM BUT HEADLINES WILL NEED TO BE ISSUED AT
SOME PERIOD. THE TRANSITION FROM HEAVY RAIN IN THE SOUTHEASTERN
CWA TO HEAVY SNOW IN THE NORTHWEST WILL NEED TO ACCOMMODATE THE
PTYPE CHANGEOVER WHICH STANDS A CHANCE OF INCLUDING FREEZING RAIN
AND/OR SLEET FOR MUCH OF THE CWA ALONG THE I-71 CORRIDOR.
PUTTING A WATCH OUT FOR THIS PERIOD SEEMED HASTY AT THIS MOMENT IN
TIME. NORTHWEST CWA MAY NOT EVEN REACH THE WARNING CRITERIA OF 6
INCHES...ADDING TO THE WAIT-AND-SEE APPROACH FOR TUESDAY NIGHTS
STORM. A STRONG WARM PUSH LATE IN THE DAY TUESDAY COULD ALSO PUT A
MONKEY WRENCH TO THE FORECAST TEMPERATURES AND SUBSEQUENT PTYPE.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
PERIOD WILL BEGIN WITH THE CENTER OF THE STORM SYSTEM EAST OF THE
REGION IN THE APPALACHIANS. AS THE LOW RACES AWAY FROM THE
REGION...THE PCPN WILL TAPER DOWN FROM SW TO NW. FOR THE MAJORITY OF
THE REGION THE PTYPE WILL BE SNOW AT 12Z WED. THE EXCEPTION WILL BE
IN THE SE COUNTIES WHERE AN AREA OF RAIN AND WINTRY MIX WILL STILL
BE LINGERING. THIS AREA SHOULD CHANGE TO SNOW QUICKLY WEDNESDAY
MORNING.
HIGH PRESSURE WILL SETTLE DOWN INTO THE NATIONS MID SECTION...WED
NGT INTO THU. THIS WILL BRING ANOTHER ROUND MUCH BELOW NORMAL
TEMPERATURES TO THE REGION. LOWS THURSDAY MORNING WILL RANGE FROM
AROUND 5 DEGREES IN THE NW TO 15 IN THE SE. HIGHS ON THURSDAY ARE
EXPECTED TO ONLY REACH THE TEENS IN THE NW AND 25 TO 30 IN THE SE.
AS THE HIGH BUILDS UP THE OHIO VALLEY THURSDAY INTO FRIDAY THE ECMWF
IS AN OUTLIER IS IT BRINGS AN AREA OF LIGHT PCPN TO THE REGION THU
NGT INTO FRI. THIS APPEARS TO BE SOME TYPE OF MID LEVEL FORCING.
RIGHT NOW LEFT THE REGION DRY TO SEE HOW LATER RUNS HANDLE IT.
MODELS TRY AND DEVELOP AN OTHER STORM SYSTEM FOR NEXT WEEKEND IN THE
SPLIT FLOW ALOFT. THE ECMWF IS QUICKER IN EJECTING THE ENERGY UP THE
E COAST WILL THE TAKES THE H5 LOW AND CUTS IT OFF IN THE MIDDLE OF
THE COUNTRY AND PRODUCES A DEEP SFC LOW OVER THE MS VALLEY. WILL
LEAN TOWARDS THE ECMWF SOLUTION WHICH SEEM TO HAVE THE SUPPORT OF
THE MEAN ENSEMBLES. AT THIS TIME IT LOOKS LIKE ANOTHER
RAIN...SNOW...MIXED PCPN SYSTEM FOR THE REGION.
THE SYSTEM PULLS OUT SUNDAY AND HIGH PRESSURE BUILDS IN BY LATE
SUNDAY.
TEMPERATURES WILL GENERALLY REMAIN BELOW NORMAL THRU THE PERIOD. THE
EXCEPTION MIGHT BE SATURDAY WITH THE STORM SYSTEM AFFECTING THE
REGION.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
MAINLY MVFR CEILINGS WILL PERSIST THROUGH THE FIRST HALF OF THE
TAF PERIOD. SNOW WILL TRACK EAST NORTHEAST WHICH WILL PUT ALL BUT
THE DAYTON TERMINAL ON THE NORTHERN EDGE OF PRECIPITATION. APPEARS
THAT THERE WILL BE SEVERAL HOURS OF SNOW WITH VISIBILITIES
OCCASIONALLY DOWN TO IFR FROM KCVG TO KILN. SNOW MAY REMAIN ON THE
LIGHTER SIDE IN THE COLUMBUS AREA WITH VISIBILITY RESTRICTIONS
ONLY MVFR. DAYTON WILL BE DRY. SNOW WILL PUSH OFF TO THE EAST OF
THE AREA BEFORE 12Z. CEILINGS MAY LIFT ABOVE 2000 FT FOR A FEW
HOURS BEFORE BECOMING SCATTERED BY 18Z WITH VFR THROUGH THE
REMAINDER OF THE TAF PERIOD.
OUTLOOK...MVFR TO IFR CEILINGS AND VISIBILITIES ARE LIKELY WITH
A WINTRY MIX OF PRECIPITATION LATE TUESDAY INTO WEDNESDAY MORNING.
MVFR CEILINGS AND VISIBILITIES MAY LINGER INTO WEDNESDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR OHZ063>065-
072>074-077-078-080.
WINTER STORM WARNING UNTIL 10 AM EST MONDAY FOR OHZ079-081-082-
088.
KY...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR KYZ089>093.
WINTER STORM WARNING UNTIL 10 AM EST MONDAY FOR KYZ094>100.
IN...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR INZ075-080.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...
SHORT TERM...FRANKS
LONG TERM...SITES
AVIATION...
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1008 AM CST SAT FEB 1 2014
.UPDATE...GUSTY SOUTH WINDS WILL CONTINUE THROUGH THE AFTERNOON,
WITH SOME GUSTS TO AROUND 30 MPH. THESE WINDS WILL CERTAINLY DO A
GOOD JOB TO PULL WARMER AIR IN ACROSS OUR AREA AND THE BIG WARM-UP
IS ALREADY WELL UNDERWAY. BY MID-MORNING, TEMPS WERE ALREADY IN
THE 50S AT MOST LOCATIONS, AND STILL BELIEVE HIGHS THIS AFTERNOON
WILL TOP OUT ANYWHERE FROM 59 TO 63 DEGREES.
LATEST RUC SHOWS PRECIP STAYING TO OUR NORTHWEST THROUGH 00Z, AND
HAVE TRIMMED OUR SLIGHT CHANCE AREA TO JUST THE EXTREME NORTHWEST
PART OF STEWART COUNTY FOR THIS AFTERNOON.
HAVE UPDATED GRIDS TO REFLECT MOST RECENT OBSERVATIONS AND TRENDS.
OVERALL, LITTLE CHANGE TO PREVIOUS FORECAST.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
19
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1135 PM CST FRI JAN 31 2014
.AVIATION...
/06Z TAFS/
I didn`t make any major changes to the terminals this forecast
cycle. The latest NAM 925 MB relative humidity field indicates
stratus could move into the Big Country later tonight; however, I
believe persistent high clouds will preclude this. Thus, expect VFR
conditions at the Abilene and San Angelo terminals for the next 24
hours. The cold front, which has stalled near our Interstate 20
corridor, will begin to push farther south tomorrow afternoon. By
03Z, plan for north surface winds to dominate West Central Texas.
Huber
&&
.PREV DISCUSSION... /ISSUED 735 PM CST FRI JAN 31 2014/
UPDATE...
To lower temperatures across the Big country...
DISCUSSION...
A cold front is currently located just south of Interstate 20.
Models do not seem to be handling the front very well, and
temperatures across the Northern Big Country have already fallen
to forecast lows at several locations. The HRRR seems to be
handling the front best, and is forecasting the front to remain
stalled across the Big Country, with temperatures falling into the
lower to mid 30s across Haskell and Throckmorton counties, to the
lower to mid 40s for most other locations in the Big Country. I
lowered temperatures mainly north of Interstate 20, and will
continue to monitor this evening. No other changes are needed at
this time.
Daniels
PREV DISCUSSION... /ISSUED 542 PM CST FRI JAN 31 2014/
AVIATION...
/00Z TAFS/
Look for stratus to bring MVFR ceilings back to West Central Texas
tonight. Models this cycle indicate the stratus return will begin a
few hours earlier than it did last night, and the coverage will be
slightly farther north. As the previous forecast indicated, I don`t
think the stratus will impact the San Angelo terminal. So, expect
VFR there and at Abilene for the next 24 hours.
Huber
PREV DISCUSSION... /ISSUED 354 PM CST Fri Jan 31 2014/
SHORT TERM...
(Tonight and Saturday)
Broad troughing characterizes the western half of the CONUS this
afternoon with west/southwest flow over Texas. To our west, a
shortwave trough is moving east toward the area along the southern
end of the broad troughing in place. At the surface, a cold front
with a wide range of temperatures on either side of this feature.
The temperature as of 2 PM in Haskell was 50 degrees, while in
Abilene it was 78. The front could be seen on radar imagery
continuing to slowly creep southward. However, with the
aforementioned shortwave trough approaching the area, surface
troughing across higher terrain in New Mexico and west Texas is
expected to intensify, and push this boundary back to just north of
the area overnight, so have kept lows tonight in the lower to mid
40s for areas north of Interstate 20 tonight, and upper 40s to lower
50s for the rest of the area. In any event, the front is expected to
be nearly stationary through the next 24 hours.
For Saturday, with the front stalled in or near our northern
counties, have lowered highs for this area tomorrow. South of the
front, downsloping west winds will pick up to 15 to 20 mph, and we
will see another warm day of highs in the 70s south of a Sterling
City to Brownwood line.
20
LONG TERM...
(Sunday into Friday)
..Wintry Mix possible late Saturday night and Sunday with the Big
Country the main focus of concern....
Cold air will continued flow into the region Saturday night and
Sunday. Lift associated with an upper shortwave may bring a chance
of wintry mix, mainly after 3 AM Sunday morning and continuing
through the day Sunday. GFS model indicates a combination of sleet
and freezing rain, with possible snow mixed in north of I-20. The
main focus of the wintry mix is in the Big Country, although a
mixture of freezing and sleet possible farther south to San Angelo
and Brownwood.
The main area of concern is in Big County, particularly in northern
sections: Fisher, Haskell and Throckmorton. Both the GFS and NAM
models are focusing their highest QFPs of 1/4 inch in this area.
With a 10 to 1 snow/liquid ratio, potential exists for 2-3 inches of
snow, although significant uncertainty remains if and where it may
develop. Northern areas however are more climatologically favorable
for snow. I have put in about 1 inch of snow for Sunday from Roby to
Haskell and to Throckmorton. In addition, there could be a few
hundredths inch of freezing rain/sleet throughout the Big Country.
While snow or freezing rain amounts will likely stay below winter
storm warning criteria, their impact could still be significant due
to falling temperatures into the mid and upper 20s during the day on
Sunday. Well below freezing temperatures the 20s could cause very
icy and hazardous conditions on highways, especially bridges and
overpasses. If any ice does occur, icy conditions may persist into
Monday morning as temperatures fall into the lower 20s. Temperatures
in the Big Country may not rise above freezing until late morning
morning.
A second upper shortwave will affect the region Monday afternoon and
night. Temperatures however are expected to warmer with southeast
winds, and precipitation should fall as rain. It will be still
warmer on Tuesday as a surface low moves across North Texas,
bringing compressional warming and dry westerly winds.
An arctic front still indicated to move through Tuesday night,
keeping the region very cold into Friday. Both the GFS and EC models
indicate a long wave trough approaching from the southwest, and
there it potential for some light precipitation as mid level
moisture aloft is lifted over the cold air at the surface. There is
the potential for snow (the GFS model for Abilene indicates all snow
Thursday and Thursday night). Amounts at this time appear light on
the 12Z EC and GFS models.
04
Fire Weather...
Expect elevated fire weather conditions to continue through Saturday
afternoon, especially south of Interstate 20. With slightly cooler
temperatures expected Saturday, relative humidity values will not be
as low as today, dropping into the 20 to 25 percent range. Winds
should remain below critical thresholds, remaining in the 15 to 20
mph range. MUCH colder air will move in Saturday night into Sunday
with temperatures struggling to reach freezing along and north of a
Sterling City to Brownwood line Sunday, and mid 30s to lower 40s for
the rest of the area.
Elevated to near critical conditions will return Tuesday as west
winds pick up and relative humidity values fall to near 20 percent
for areas south of I-20. Another cold air mass will move into the
area for Wednesday through the rest of the week.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 46 62 27 28 22 / 0 5 10 40 10
San Angelo 48 74 31 34 24 / 0 0 10 30 10
Junction 53 76 37 39 27 / 5 5 10 20 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
04/20/Daniels/Huber
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
949 PM EST SUN FEB 2 2014
.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL MOVE UP FROM THE SOUTHEAST ALONG A
NEARLY STATIONAL FRONTAL BOUNDARY ALONG THE BLUE RIDGE OVERNIGHT
...AND THEN OFF THE VIRGINIA COAST BY LATE MONDAY. HIGH PRESSURE
WILL THEN MOVE ACROSS THE OHIO VALLEY INTO THE MID ATLANTIC ON
TUESDAY...WITH ANOTHER STORM SYSTEM MOVING OVER THE REGION TUESDAY
NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 945 PM EST SUNDAY...
THE AFTERNOON MODELS...INCLUDING MANY HIGH RESOLUTION MODELS...AND
THE TRENDS IN THE BROAD SHIELD OF PRECIPITATION UPSTREAM TO THE
SOUTHWEST...ARE ALL SHOWING INDICATIONS THAT PRECIPITATION
OVERNIGHT INTO EARLY MONDAY MORNING WILL LIKELY BE HEAVIER...WITH
MANY LOCATIONS WELL OVER AN INCH ACROSS WESTERN AND CENTRAL
PORTIONS OF THE FCST AREA...WITH OVER AN INCH AND A HALF OR EVEN
CLOSE TO TWO INCHES LOCALLY. ALL OF THIS WILL FALL MAINLY IN A 6-8
HOUR PERIOD FROM ABOUT 2 AM TO THE MID MORNING HOURS MONDAY. THIS
IS GENERALLY ABOVE THE 6 HR FLASH FLOOD GUIDANCE...AND WITH THE
GROUND FROZEN JUST ABOVE THE SURFACE AND EVEN A LITTLE SNOW PACK
LEFT IN THE HIGHEST ELEVATIONS...THE RUNOFF WIL OCCUR QUICKLY.
RAINFALL RATES ARE NOT LIKELY TO BE ESPECIALLY HIGH...SO THINK
FLASH FLOODING IS A RELATIVELY LOW THREAT...BUT AM CONCERNED ABOUT
MINOR FLOODING OF STREAMS AND CREEKS...AND POTENTIALLY SOME
LARGER RIVERS SUCH AS THE GREENBRIER AND BLUESTONE. ICE BREAKING
UP ON THESE RIVERS AND STREAMS IS ANOTHER CONCERN WITH THE RECENT
MILD WEATHER AND NOW RAINFALL ON TOP. THEREFORE..DECIDED TO GO
WITH A FLOOD WATCH FOR WESTERN COUNTIES FROM TAZEWELL UP THROUGH
GREENBRIER AND BATH...WITH GREENBRIER REALLY BEING THE HIGHEST
THREAT AREA AS THE HEAVIEST RAIN BULLSEYE COMBINING WITH THE
LOCATION WHERE THE MOST SNOW REMAINS ON THE GROUND. RAN THIS
THROUGH 6PM MONDAY WELL AFTER THE RAIN WILL HAVE TAPERING
OFF...BUT IF ANY FLOODING DOES OCCUR IT MAY LINGER BEYOND THIS.
TEMPERATURES THIS EVENING HAVE BEEN RUNNING MILDER THAN EXPECTED
ANAD GUIDANCE...AND WITH TRENDS IN MODELS AND OBSERVATIONS
SUGGESTING A SLOWER ARRIVAL OF COLDER AIR...BUMPED UP MIN TEMPS A
FEW DEG OVERNIGHT AND RESULTING IN A LITTLE LESS AREA WITH
ACCUMULATING SNOWFALL VERY LATE TONIGHT AND INTO TOMORROW MORNING.
HOWEVER...THOSE HIGHEST ELEVATIONS THAT DO CHANGE OVER TO SNOW MAY
AHVE HIGHER SNOWFALL RATES...ALBEIT A FAIRLY WET HEAVY SNOW...SO
ENDED UP INCREASING THE AMOUNTS BUT OVER SMALL GEOGRAPHICAL AREA.
MAY SEE A QUICK BURST OF 2-3 INCHES IN WRN GREENBRIER OR THE
HIGHEST RIDGES OF BATH EARLY IN THE MORNING...LINGERING THROUGH
MID TO LATE MORNING. BUT MOST AREAS OUTSIDE THIS LOOK TO SEE ONLY
COLD RAIN...BUT PERHAPS MORE OF THAT.
PREV DISCUSSION AS OF 505 PM EST SUNDAY...
MINOR UPDATE TO LOWER POPS THIS EVENING IN WEST AS PRECIP TAKING
ITS TIME TO ADVANCE INTO RELATIVDELY DRY AIRMASS. RADAR MOSAIC AND
LATEST HRRR AND RAP MODELS SUGGEST ANY ACCUMULATING PRECIP MAY
HOLD OFF UNTIL LATE EVENING. TWEAKED SKY COVER AS WELL TO ADJUST
FOR PARTIAL CLEARING IN EAST WHICH MAY NOT THICKEN BACK UP UNTIL
LATE EVENING AS WELL. VERY MINOR TWEAKS TO TEMPS PER LATEST
CONDITIONS...SLOWING DOWN EVENING COOLING A BIT. OTHERWISE NO
OTHER CHANGES AT THIS POINT.
PREV DISCUSSION AS OF 235 PM EST SUNDAY...
MODELS SHOWING A MAINLY RAIN EVENT FOR OUR FORECAST AREA. THE FRONT
HAS BEEN SLOW TO MOVE THIS AFTERNOON THANKS TO THE HIGH OVER THE
SOUTHEAST...AND LACK OF KICKER UPSTREAM. SHORTWAVE ENERGY OVER TX/OK
THIS AFTERNOON WILL BE PUSHING THE FRONT EAST-SOUTHEAST THROUGH
TONIGHT...WHERE IT STALLS FROM THE SOUTHERN APPALACHIANS INTO THE VA
PIEDMONT. STRONG DYNAMICS ALOFT SUPPORT THE IDEA OF A 6-8 HOUR
WINDOW OF MODERATE AND POSSIBLY HEAVY RAIN...STARTING AFTER MIDNIGHT
IN THE WV MTNS AND SPREADING EAST INTO THE PIEDMONT BY DAWN. GOING
TO BE A TRICKY SCENARIO ACROSS OUR NRN/NWRN FRINGE OF THE CWA FROM
GREENBRIER TO AMHERST AS MODEL FLIRTING WITH THE 8H ZERO ISOTHERM
SHIFTING SE ONCE THE SURFACE LOW PASSES EAST AFTER 12Z. QUESTION IS
HOW MUCH QPF IS LEFT. AT THIS TIME WPC FAVORS LOW SNOW AMOUNTS. NOT
SEEING ANY ICE ISSUES PER MODEL SOUNDINGS...BUT COULD SEE SLEET INTO
THE MOUNTAIN EMPIRE OF TAZEWELL. HIGHER ELEVATIONS OF GREENBRIER AND
BATH INTO THE BLUE RIDGE COULD PICK UP A QUICK 1-2 INCHES OF SNOW
WITH ISOLATED 3 INCH AMOUNTS NOT OF THE QUESTION...BUT SWEET SPOT
FOR SNOW LOVERS WILL BE FURTHER NORTH OF US. JUST A COLD RAIN FOR 95
PERCENT OF OUR AREA.
TEMPS THROUGH THE PERIOD WILL STAY MOSTLY ABOVE FREEZING AS CLOUDS
START TO ENVELOP THE REGION THIS EVENING...HOLDING TEMPS UP. WE WILL
SEE DEWPOINTS INCREASE AS WELL WITH THE LIGHT RAIN SHOWERS
MOISTENING THE LOW LVLS...AND SCOURING OUT ANY RESIDUAL DRY AIR.
OVERNIGHT LOWS WILL RANGE FROM AROUND FREEZING IN THE HIGHER RIDGES
OF AMHERST TO GREENBRIER WITH MID TO UPPER 30S I-81 CORRIDOR AND
EAST TO LYH WHILE SOUTHSIDE VA INTO THE NC COUNTIES DROP TO LOWER
40S.
CLOUDS/PRECIP TOMORROW LIMIT HEATING. SUNSHINE APPEARS TO BE TOO LATE
IN HELPING IN THE WEST BUT GIVEN A LACK OF DECENT COLD ADVECTION
BEHIND THE DEPARTING LOW...WILL SEE TEMPS ON THE COOLER SIDE OF
SEASONAL NORMS BUT NOT ARCTIC COLD....RANGING FROM THE MID TO UPPER
30S OVER THE WV MOUNTAINS INTO THE ALLEGHANYS...TO LOWER TO MID 40S
FROM LYNCHBURG TO ROANOKE...ACROSS THE NEW RIVER VALLEY INTO THE NC
MOUNTAINS...WHILE SOUTHSIDE VA AND NW NC FOOTHILLS AND PIEDMONT
REACH THE UPPER 40S TO LOWER 50S.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 257 PM EST SUNDAY...
WEDGE SETTLES ACROSS THE REGION AND STRENGTHENS OVERNIGHT INTO
TUESDAY. THE NAM/MET...WHICH USUALLY DOES BEST WITH THERMAL
STRUCTURE IN WEDGES...COOLED OFF A BIT FROM PREVIOUS RUNS. JUDGING
BY THE STRENGTH AND THE DIRECTION OF THE AGEOSTROPHIC COMPONENT...AND
THE SURFACE UPSLOPE COMPONENT OF THE WINDS...THERE`S A FAIR CHANCE
THAT SUBFREEZING AIR TEMPS ARE IN PLACE ALONG THE SPINE OF THE BLUE
RIDGE FROM SW VA INTO NW NC LATE MONDAY NIGHT AND INTO TUESDAY. THIS
WOULD MEAN THAT FREEZING DRIZZLE/RAIN IS A POSSIBILITY FROM EASTERN
ASHE/WATAUGA CREEPING UP TO FLOYD COUNTY IN THE AFTERNOON. DURING
THESE EVENTS...THE WEDGE IS TYPICALLY STRONGEST IN THE
AFTERNOON...SUCH THAT TEMPS RIGHT ALONG THE BLUE RIDGE TYPICALLY
FALL DURING THE LATE MORNING AND AFTERNOON HOURS. A WET AND WARM
GROUND WOULD PROBABLY PRECLUDE ANY LIGHT ICING ON THE ROADS...MAINLY
IN THE TREES AND ELEVATED SURFACES. ONLY HAVE A FEW HUNDREDTHS OF AN
INCH OF ICE ACCUMULATION...NOTHING TO BE TOO CONCERNED ABOUT AS OF
YET...BUT SOMETHING TO WATCH...ESPECIALLY IF THE 2M NAM TEMPS
CONTINUE TO TREND COOLER AND STAY BELOW FREEZING ALL DAY AND INTO A
SIGNIFICANT PART OF TUESDAY NIGHT. BY TUESDAY EVENING...TEMPS MAY
FALL TO FREEZING IN EASTERN AND NORTHEASTERN GREENBRIER COUNTY...AND
PERHAPS ALSO THE SOUTHERN SHENANDOAH...WITH A TOUCH OF FREEZING RAIN
THERE. ELSEWHERE...IN AND OUT SHOWERS WILL BECOME MORE NUMEROUS FROM
SW TO NE BY LATE DAY TUESDAY ACROSS THE REGION. THE MAIN BODY OF
PRECIP SHOULD ARRIVE JUST AHEAD OF THE COLD FRONT WHICH SHOULD
ARRIVE WEDNESDAY MORNING TO AFTERNOON. SOME UPSLOPE FLOW SHOULD TURN
RAIN TO SNOW WITH H85 TEMPS AROUND -9C LATE DAY IN WESTERN
GREENBRIER. MUCH OF THE RAIN MAY BE OVER WITH BY WEDNESDAY AFTERNOON
ELSEWHERE. AS THE WEDGE BREAKS WEDNESDAY MORNING...CUSTOMARY GUSTS
FROM THE SSE NEAR ADVISORY CRITERIA MAY BE OBSERVED IN THE
BLF/JFX/MKJ CORRIDOR. MORE WINTERLIKE AIR ARRIVES BEHIND THE FRONT
INTO WEDNESDAY MORNING.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 345 PM EST SUNDAY...
WILL START THURSDAY MORNING OFF WITH A BREAK IN THE WEATHER AS HIGH
PRESSURE BUILDS EAST ALONG THE SOUTHERN GREAT LAKES...AND THEN
PUSHES SOUTHWARD ALONG THE EASTERN FACE OF THE APPALACHIANS THURSDAY
EVENING INTO FRIDAY MORNING. THE CLEARING SKIES AND DOWNSLOPE WIND
FLOW WILL ALLOW THE SOUTHSIDE TO WARM INTO THE MID 40S FOR AFTERNOON
HIGHS...HOWEVER INCREASED CLOUD COVER AND COLDER AIR BUILDING IN
WITH THE HIGH WILL KEEP TEMPERATURES IN THE MOUNTAINS STUCK IN THE
30S. INCREASING CLOUD COVER DURING THE EVENING WILL HELP LIMIT
COOLING OVERNIGHT...AND WILL BE LOOKING FOR THURSDAY NIGHT LOWS TO
HOLD IN THE MID AND UPPER 20S MOST LOCATIONS.
BY FRIDAY MORNING...HIGH PRESSURE WILL BE FIRMLY SITUATED ALONG THE
EASTERN FACE OF THE APPALACHIANS...RESULTING IN A COOL EAST TO
SOUTHEASTERLY WIND FLOW THAT WILL NOT ALLOW FOR ALL THAT MUCH
WARMING. LONG RANGE MODELS HAVE DIFFERING OPINIONS AS TO HOW STRONG
AN UPPER LEVEL DISTURBANCE RIDING ALONG THE FRONTAL BOUNDARY TO OUR
SOUTH WILL BE...AND HOW MUCH RESULTING PRECIPITATION WILL AFFECT OUR
AREA. THE ECMWF FORECAST MODEL APPEARS VERY BULLISH WITH THE
PRECIPITATION...AND OVERDONE CONSIDERING THAT THE UPPER LEVEL
DISTURBANCE DOES NOT APPEAR VERY STRONG. THEREFORE...STICKING A
LITTLE CLOSER TO THE MORE CONSERVATIVE GFS MODEL AS FAR AS
PRECIPITATION CHANCES. BELIEVE WE WILL START THE DAY WITH LIGHT SNOW
THAT WILL GRADUALLY CHANGE TO RAIN AS WARMER AIR WORKS IN FROM THE
SOUTH.
FOR FRIDAY NIGHT AND SATURDAY...UNCERTAINTY IN THE FORECAST
INCREASES AS BOTH TIMING AND THE TRACK OF A DEVELOPING STORM SYSTEM
BEGINS TO DIFFER AMONG THE FORECAST MODELS. THE UPPER DISTURBANCE
WILL PASS TO THE EAST FRIDAY EVENING...RESULTING IN A BRIEF BREAK IN
THE PRECIPITATION FOR OUR AREA...BEFORE ANOTHER MUCH STRONGER TROUGH
BEGINS TO PUSH OUT OF THE SOUTHERN ROCKIES. SOUTHERLY FLOW AHEAD OF
THIS SYSTEM WILL PUSH WARMER GULF AIR INTO OUR AREA JUST OFF THE
SURFACE...WHILE THE HIGH PRESSURE WEDGE WILL KEEP SURFACE
TEMPERATURES AROUND THE FREEZING MARK FOR MUCH OF OUR AREA. AT THIS
POINT...LOOKING AT A COMPLEX FORECAST FOR FRIDAY NIGHT WITH RAIN
ACROSS THE PIEDMONT OF NORTH CAROLINA WHERE TEMPERATURES WILL REMAIN
ABOVE FREEZING...FREEZING RAIN NORTHWARD TO AROUND THE INTERSTATE 64
CORRIDOR...AND THEN SNOW FURTHER NORTH. TEMPERATURES WILL WARM ABOVE
FREEZING FOR MOST OF OUR AREA SATURDAY AFTERNOON...CAUSING NEARLY
ALL PRECIPITATION TO CHANGE OVER TO RAIN.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
AS OF 650 PM EST SUNDAY...
RAIN TO THE WEST IS A LITTLE SLOWER TO MOVE IN AND MAY NOT REACH
WESTERN TAFS SITES UNTIL 02 TO 03 UTC BUT WILL QUICKLY BRING IFR
CIGS...THEN EVENTUALLY IFR VSBYS AT TIMES LATE TONIGHT. WILL TAKE
UNTIL PREDAWN HOURS IN THE EAST...09 OR 10Z...UNTIL RAIN AND IFR
CONDITIONS ARRIVE. MAY END UP BEING EVEN SLOWER.
CONFIDENCE IS HIGH THAT IFR CONDITIONS OCCUR OVERNIGHT INTO
MONDAY MORNING AT WESTERN TAF SITES...BLF...LWB...BCB. CONFIDENCE
IS MODERATE AT EASTERN TAF SITES IN IFR CONDITIONS AND MAY NOT
OCCUR UNTIL AFTER 12Z. AS RAIN BEGINS...INSITU DAMMING WILL ALSO
INCREASE WITH SFC WINDS TURNING OUT OF THE NORTHEAST AND MAY GET
OVER 10 KTS AT LYH AND DAN.
MODERATE RAIN WITH IFR CONDITIONS WILL LIKELY EXIT FAIRLY QUICKLY
BY MIDDAY MONDAY...PERHAPS SOME LINGERING IFR CIGS AND RAIN
CHANGING TO LIGHT SNOW OR FREEZING DRIZZLE AT BLF AND LWB BEFORE
ENDING EARLY AFTERNOON. BACK TO MVFR BY MID AFTERNOON AND LIELY
VFR BY LATE AFTERNOON ALL AIRPORTS AS FLOW THEN TURNS AGAIN TO
NORTH OR NORTHWEST...BUT FAIRLY LIGHT.
THINGS CLEAR OUT WITH HIGH PRESSURE MOVING INTO THE AREA MONDAY
NIGHT-TUESDAY. NEXT SYSTEM ARRIVES FROM THE SOUTHWEST LATE TUES OR
TUESDAY NIGHT...LASTING INTO WEDNESDAY WITH ANOTHER THREAT OF
PRECIP AND LOWER CIGS/VSBYS.
ANOTHER BREAK BY WED NIGHT INTO EARLY FRIDAY WITH HIGH PRESSURE
ARRIVING FROM THE NORTHWEST BEFORE ANOTHER SYSTEM MOVES UP FROM
THE GULF COAST STATES FRIDAY AFTERNOON INTO THE WEEKEND.
&&
.HYDROLOGY...
AS OF 250 PM SUNDAY...
THREAT OF FLOODING ON THE RIVERS AND STREAMS STILL LOOKING
LOW...ALTHOUGH THE FROZEN...SOME THAWING GROUND...PLUS REPORTS OF
RIVER/STREAM ICE MAY LEAD TO ISOLATE PROBLEMS. FORECAST RAINFALL
AMOUNTS FROM THIS FIRST SYSTEM TONIGHT-MONDAY ARE INDICATING
GENERALLY 1 TO 1.5 INCHES...WITH HIGHER TOTALS ACROSS THE UPPER
ROANOKE BASIN AND PORTIONS AND JAMES. FORECASTS FROM SURROUNDING
RIVER FORECAST CENTERS SHOWING RIVERS COMING UP TO JUST UNDER ACTION
STAGES. ENSEMBLE FORECASTS ALSO INDICATING LOW RISK OF FLOODING.
THE NEXT SYSTEM ARRIVING LATER TUESDAY INTO TUESDAY NIGHT LOOKS LESS
ON PRECIP AMOUNTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH MONDAY AFTERNOON FOR VAZ007-019-020.
NC...NONE.
WV...FLOOD WATCH THROUGH MONDAY AFTERNOON FOR WVZ042>045.
&&
$$
SYNOPSIS...SK/WP
NEAR TERM...SK/WP
SHORT TERM...KM
LONG TERM...NF
AVIATION...SK/WP
HYDROLOGY...WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
659 PM EST SUN FEB 2 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL STALL OVER THE PIEDMONT REGIONS OF VIRGINIA
AND NORTH CAROLINA THIS EVENING. LOW PRESSURE WILL THEN TRACK
ALONG THIS FRONT AND INTO THE CAROLINAS BY LATE TONIGHT. HIGH
PRESSURE MOVES ACROSS THE OHIO VALLEY INTO THE MID ATLANTIC ON
TUESDAY...WITH ANOTHER STORM SYSTEM MOVING OVER THE REGION TUESDAY
NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 505 PM EST SUNDAY...
MINOR UPDATE TO LOWER POPS THIS EVENING IN WEST AS PRECIP TAKING
ITS TIME TO ADVANCE INTO RELATIVDELY DRY AIRMASS. RADAR MOSAIC AND
LATEST HRRR AND RAP MODELS SUGGEST ANY ACCUMULATING PRECIP MAY
HOLD OFF UNTIL LATE EVENING. TWEAKED SKY COVER AS WELL TO ADJUST
FOR PARTIAL CLEARING IN EAST WHICH MAY NOT THICKEN BACK UP UNTIL
LATE EVENING AS WELL. VERY MINOR TWEAKS TO TEMPS PER LATEST
CONDITIONS...SLOWING DOWN EVENING COOLING A BIT. OTHERWISE NO
OTHER CHANGES AT THIS POINT.
PREV DISCUSSION AS OF 235 PM EST SUNDAY...
MODELS SHOWING A MAINLY RAIN EVENT FOR OUR FORECAST AREA. THE FRONT
HAS BEEN SLOW TO MOVE THIS AFTERNOON THANKS TO THE HIGH OVER THE
SOUTHEAST...AND LACK OF KICKER UPSTREAM. SHORTWAVE ENERGY OVER TX/OK
THIS AFTERNOON WILL BE PUSHING THE FRONT EAST-SOUTHEAST THROUGH
TONIGHT...WHERE IT STALLS FROM THE SOUTHERN APPALACHIANS INTO THE VA
PIEDMONT. STRONG DYNAMICS ALOFT SUPPORT THE IDEA OF A 6-8 HOUR
WINDOW OF MODERATE AND POSSIBLY HEAVY RAIN...STARTING AFTER MIDNIGHT
IN THE WV MTNS AND SPREADING EAST INTO THE PIEDMONT BY DAWN. GOING
TO BE A TRICKY SCENARIO ACROSS OUR NRN/NWRN FRINGE OF THE CWA FROM
GREENBRIER TO AMHERST AS MODEL FLIRTING WITH THE 8H ZERO ISOTHERM
SHIFTING SE ONCE THE SURFACE LOW PASSES EAST AFTER 12Z. QUESTION IS
HOW MUCH QPF IS LEFT. AT THIS TIME WPC FAVORS LOW SNOW AMOUNTS. NOT
SEEING ANY ICE ISSUES PER MODEL SOUNDINGS...BUT COULD SEE SLEET INTO
THE MOUNTAIN EMPIRE OF TAZEWELL. HIGHER ELEVATIONS OF GREENBRIER AND
BATH INTO THE BLUE RIDGE COULD PICK UP A QUICK 1-2 INCHES OF SNOW
WITH ISOLATED 3 INCH AMOUNTS NOT OF THE QUESTION...BUT SWEET SPOT
FOR SNOW LOVERS WILL BE FURTHER NORTH OF US. JUST A COLD RAIN FOR 95
PERCENT OF OUR AREA.
TEMPS THROUGH THE PERIOD WILL STAY MOSTLY ABOVE FREEZING AS CLOUDS
START TO ENVELOP THE REGION THIS EVENING...HOLDING TEMPS UP. WE WILL
SEE DEWPOINTS INCREASE AS WELL WITH THE LIGHT RAIN SHOWERS
MOISTENING THE LOW LVLS...AND SCOURING OUT ANY RESIDUAL DRY AIR.
OVERNIGHT LOWS WILL RANGE FROM AROUND FREEZING IN THE HIGHER RIDGES
OF AMHERST TO GREENBRIER WITH MID TO UPPER 30S I-81 CORRIDOR AND
EAST TO LYH WHILE SOUTHSIDE VA INTO THE NC COUNTIES DROP TO LOWER
40S.
CLOUDS/PRECIP TOMORROW LIMIT HEATING. SUNSHINE APPEARS TO BE TOO LATE
IN HELPING IN THE WEST BUT GIVEN A LACK OF DECENT COLD ADVECTION
BEHIND THE DEPARTING LOW...WILL SEE TEMPS ON THE COOLER SIDE OF
SEASONAL NORMS BUT NOT ARCTIC COLD....RANGING FROM THE MID TO UPPER
30S OVER THE WV MOUNTAINS INTO THE ALLEGHANYS...TO LOWER TO MID 40S
FROM LYNCHBURG TO ROANOKE...ACROSS THE NEW RIVER VALLEY INTO THE NC
MOUNTAINS...WHILE SOUTHSIDE VA AND NW NC FOOTHILLS AND PIEDMONT
REACH THE UPPER 40S TO LOWER 50S.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 257 PM EST SUNDAY...
WEDGE SETTLES ACROSS THE REGION AND STRENGTHENS OVERNIGHT INTO
TUESDAY. THE NAM/MET...WHICH USUALLY DOES BEST WITH THERMAL
STRUCTURE IN WEDGES...COOLED OFF A BIT FROM PREVIOUS RUNS. JUDGING
BY THE STRENGTH AND THE DIRECTION OF THE AGEOSTROPHIC COMPONENT...AND
THE SURFACE UPSLOPE COMPONENT OF THE WINDS...THERE`S A FAIR CHANCE
THAT SUBFREEZING AIR TEMPS ARE IN PLACE ALONG THE SPINE OF THE BLUE
RIDGE FROM SW VA INTO NW NC LATE MONDAY NIGHT AND INTO TUESDAY. THIS
WOULD MEAN THAT FREEZING DRIZZLE/RAIN IS A POSSIBILITY FROM EASTERN
ASHE/WATAUGA CREEPING UP TO FLOYD COUNTY IN THE AFTERNOON. DURING
THESE EVENTS...THE WEDGE IS TYPICALLY STRONGEST IN THE
AFTERNOON...SUCH THAT TEMPS RIGHT ALONG THE BLUE RIDGE TYPICALLY
FALL DURING THE LATE MORNING AND AFTERNOON HOURS. A WET AND WARM
GROUND WOULD PROBABLY PRECLUDE ANY LIGHT ICING ON THE ROADS...MAINLY
IN THE TREES AND ELEVATED SURFACES. ONLY HAVE A FEW HUNDREDTHS OF AN
INCH OF ICE ACCUMULATION...NOTHING TO BE TOO CONCERNED ABOUT AS OF
YET...BUT SOMETHING TO WATCH...ESPECIALLY IF THE 2M NAM TEMPS
CONTINUE TO TREND COOLER AND STAY BELOW FREEZING ALL DAY AND INTO A
SIGNIFICANT PART OF TUESDAY NIGHT. BY TUESDAY EVENING...TEMPS MAY
FALL TO FREEZING IN EASTERN AND NORTHEASTERN GREENBRIER COUNTY...AND
PERHAPS ALSO THE SOUTHERN SHENANDOAH...WITH A TOUCH OF FREEZING RAIN
THERE. ELSEWHERE...IN AND OUT SHOWERS WILL BECOME MORE NUMEROUS FROM
SW TO NE BY LATE DAY TUESDAY ACROSS THE REGION. THE MAIN BODY OF
PRECIP SHOULD ARRIVE JUST AHEAD OF THE COLD FRONT WHICH SHOULD
ARRIVE WEDNESDAY MORNING TO AFTERNOON. SOME UPSLOPE FLOW SHOULD TURN
RAIN TO SNOW WITH H85 TEMPS AROUND -9C LATE DAY IN WESTERN
GREENBRIER. MUCH OF THE RAIN MAY BE OVER WITH BY WEDNESDAY AFTERNOON
ELSEWHERE. AS THE WEDGE BREAKS WEDNESDAY MORNING...CUSTOMARY GUSTS
FROM THE SSE NEAR ADVISORY CRITERIA MAY BE OBSERVED IN THE
BLF/JFX/MKJ CORRIDOR. MORE WINTERLIKE AIR ARRIVES BEHIND THE FRONT
INTO WEDNESDAY MORNING.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 345 PM EST SUNDAY...
WILL START THURSDAY MORNING OFF WITH A BREAK IN THE WEATHER AS HIGH
PRESSURE BUILDS EAST ALONG THE SOUTHERN GREAT LAKES...AND THEN
PUSHES SOUTHWARD ALONG THE EASTERN FACE OF THE APPALACHIANS THURSDAY
EVENING INTO FRIDAY MORNING. THE CLEARING SKIES AND DOWNSLOPE WIND
FLOW WILL ALLOW THE SOUTHSIDE TO WARM INTO THE MID 40S FOR AFTERNOON
HIGHS...HOWEVER INCREASED CLOUD COVER AND COLDER AIR BUILDING IN
WITH THE HIGH WILL KEEP TEMPERATURES IN THE MOUNTAINS STUCK IN THE
30S. INCREASING CLOUD COVER DURING THE EVENING WILL HELP LIMIT
COOLING OVERNIGHT...AND WILL BE LOOKING FOR THURSDAY NIGHT LOWS TO
HOLD IN THE MID AND UPPER 20S MOST LOCATIONS.
BY FRIDAY MORNING...HIGH PRESSURE WILL BE FIRMLY SITUATED ALONG THE
EASTERN FACE OF THE APPALACHIANS...RESULTING IN A COOL EAST TO
SOUTHEASTERLY WIND FLOW THAT WILL NOT ALLOW FOR ALL THAT MUCH
WARMING. LONG RANGE MODELS HAVE DIFFERING OPINIONS AS TO HOW STRONG
AN UPPER LEVEL DISTURBANCE RIDING ALONG THE FRONTAL BOUNDARY TO OUR
SOUTH WILL BE...AND HOW MUCH RESULTING PRECIPITATION WILL AFFECT OUR
AREA. THE ECMWF FORECAST MODEL APPEARS VERY BULLISH WITH THE
PRECIPITATION...AND OVERDONE CONSIDERING THAT THE UPPER LEVEL
DISTURBANCE DOES NOT APPEAR VERY STRONG. THEREFORE...STICKING A
LITTLE CLOSER TO THE MORE CONSERVATIVE GFS MODEL AS FAR AS
PRECIPITATION CHANCES. BELIEVE WE WILL START THE DAY WITH LIGHT SNOW
THAT WILL GRADUALLY CHANGE TO RAIN AS WARMER AIR WORKS IN FROM THE
SOUTH.
FOR FRIDAY NIGHT AND SATURDAY...UNCERTAINTY IN THE FORECAST
INCREASES AS BOTH TIMING AND THE TRACK OF A DEVELOPING STORM SYSTEM
BEGINS TO DIFFER AMONG THE FORECAST MODELS. THE UPPER DISTURBANCE
WILL PASS TO THE EAST FRIDAY EVENING...RESULTING IN A BRIEF BREAK IN
THE PRECIPITATION FOR OUR AREA...BEFORE ANOTHER MUCH STRONGER TROUGH
BEGINS TO PUSH OUT OF THE SOUTHERN ROCKIES. SOUTHERLY FLOW AHEAD OF
THIS SYSTEM WILL PUSH WARMER GULF AIR INTO OUR AREA JUST OFF THE
SURFACE...WHILE THE HIGH PRESSURE WEDGE WILL KEEP SURFACE
TEMPERATURES AROUND THE FREEZING MARK FOR MUCH OF OUR AREA. AT THIS
POINT...LOOKING AT A COMPLEX FORECAST FOR FRIDAY NIGHT WITH RAIN
ACROSS THE PIEDMONT OF NORTH CAROLINA WHERE TEMPERATURES WILL REMAIN
ABOVE FREEZING...FREEZING RAIN NORTHWARD TO AROUND THE INTERSTATE 64
CORRIDOR...AND THEN SNOW FURTHER NORTH. TEMPERATURES WILL WARM ABOVE
FREEZING FOR MOST OF OUR AREA SATURDAY AFTERNOON...CAUSING NEARLY
ALL PRECIPITATION TO CHANGE OVER TO RAIN.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 650 PM EST SUNDAY...
RAIN TO THE WEST IS A LITTLE SLOWER TO MOVE IN AND MAY NOT REACH
WESTERN TAFS SITES UNTIL 02 TO 03 UTC BUT WILL QUICKLY BRING IFR
CIGS...THEN EVENTUALLY IFR VSBYS AT TIMES LATE TONIGHT. WILL TAKE
UNTIL PREDAWN HOURS IN THE EAST...09 OR 10Z...UNTIL RAIN AND IFR
CONDITIONS ARRIVE. MAY END UP BEING EVEN SLOWER.
CONFIDENCE IS HIGH THAT IFR CONDITIONS OCCUR OVERNIGHT INTO
MONDAY MORNING AT WESTERN TAF SITES...BLF...LWB...BCB. CONFIDENCE
IS MODERATE AT EASTERN TAF SITES IN IFR CONDITIONS AND MAY NOT
OCCUR UNTIL AFTER 12Z. AS RAIN BEGINS...INSITU DAMMING WILL ALSO
INCREASE WITH SFC WINDS TURNING OUT OF THE NORTHEAST AND MAY GET
OVER 10 KTS AT LYH AND DAN.
MODERATE RAIN WITH IFR CONDITIONS WILL LIKELY EXIT FAIRLY QUICKLY
BY MIDDAY MONDAY...PERHAPS SOME LINGERING IFR CIGS AND RAIN
CHANGING TO LIGHT SNOW OR FREEZING DRIZZLE AT BLF AND LWB BEFORE
ENDING EARLY AFTERNOON. BACK TO MVFR BY MID AFTERNOON AND LIELY
VFR BY LATE AFTERNOON ALL AIRPORTS AS FLOW THEN TURNS AGAIN TO
NORTH OR NORTHWEST...BUT FAIRLY LIGHT.
THINGS CLEAR OUT WITH HIGH PRESSURE MOVING INTO THE AREA MONDAY
NIGHT-TUESDAY. NEXT SYSTEM ARRIVES FROM THE SOUTHWEST LATE TUES OR
TUESDAY NIGHT...LASTING INTO WEDNESDAY WITH ANOTHER THREAT OF
PRECIP AND LOWER CIGS/VSBYS.
ANOTHER BREAK BY WED NIGHT INTO EARLY FRIDAY WITH HIGH PRESSURE
ARRIVING FROM THE NORTHWEST BEFORE ANOTHER SYSTEM MOVES UP FROM
THE GULF COAST STATES FRIDAY AFTERNOON INTO THE WEEKEND.
&&
.HYDROLOGY...
AS OF 250 PM SUNDAY...
THREAT OF FLOODING ON THE RIVERS AND STREAMS STILL LOOKING
LOW...ALTHOUGH THE FROZEN...SOME THAWING GROUND...PLUS REPORTS OF
RIVER/STREAM ICE MAY LEAD TO ISOLATE PROBLEMS. FORECAST RAINFALL
AMOUNTS FROM THIS FIRST SYSTEM TONIGHT-MONDAY ARE INDICATING
GENERALLY 1 TO 1.5 INCHES...WITH HIGHER TOTALS ACROSS THE UPPER
ROANOKE BASIN AND PORTIONS AND JAMES. FORECASTS FROM SURROUNDING
RIVER FORECAST CENTERS SHOWING RIVERS COMING UP TO JUST UNDER ACTION
STAGES. ENSEMBLE FORECASTS ALSO INDICATING LOW RISK OF FLOODING.
THE NEXT SYSTEM ARRIVING LATER TUESDAY INTO TUESDAY NIGHT LOOKS LESS
ON PRECIP AMOUNTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...SK/WP
NEAR TERM...WP
SHORT TERM...KM
LONG TERM...NF
AVIATION...SK/WP
HYDROLOGY...WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
552 PM CST SUN FEB 2 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SYNOPSIS...
ISSUED AT 224 PM CST SUN FEB 2 2014
FAIRLY QUIET MID-WINTER WX WITH CONTINUED BELOW NORMAL
TEMPERATURES AND JUST SOME LIGHT SNOW OR FLURRIES AT TIMES.
THE FLOW OVER THE NERN PAC WL BECOME INCREASINGLY BLOCKY AS STG
POSITIVE HEIGHT ANOMALY GRADUALLY RETROGRADES TOWARD THE
DATELINE. THE FLOW DOWNSTREAM ACRS NOAM IS SPLIT...WITH SRN AND
NRN STREAMS UNDERCUTTING AND FLOWING ARND THE NERN PAC BLOCK
/RESP/ BEFORE MERGING BACK TOGETHER OVER THE ERN CONUS. THE FCST
AREA HAS BECOME POSITIONED WITHIN THE CONFLUENT ZONE BETWEEN THE
MERGING STREAMS...AND THAT SHOULD CONT FOR THE FCST PERIOD. THAT
WL DIRECT THE MAIN WX PRODUCING SYSTEMS ARND THE AREA TO THE N AND
S...LEADING TO FAIRLY TRANQUIL MIX-WINTER WX. EXPECT SOME LIGHT
SNOW/FLURRIES AT TIMES AS THE FCST AREA GETS GRAZED BY THE TAIL OF
NRN STREAM SHRTWVS OR THE NRN FRINGE OF SRN STREAM CYCLONES...BUT
THESE ARE NOT EXPECTED TO BE SIG PCPN EVENTS. TEMPS WL REMAIN WELL
BLO NORMAL...BUT NOT AS BRUTALLY COLD AS THEY WERE AT TIMES DURING
JANUARY.
&&
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 224 PM CST SUN FEB 2 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE CENTERED FROM THE CENTRAL MISSISSIPPI VALLEY TO THE CENTRAL
GREAT PLAINS EARLY THIS AFTERNOON. AN AREA OF LOW STRATUS IS MOVING
JUST NORTH OF DUE EAST OVER NORTHERN MINNESOTA AND THE SOUTHERN EDGE
MAY JUST BRUSH NORTH-CENTRAL WISCONSIN LATER THIS AFTERNOON. CIRRUS
FROM A SOUTHERN STREAM SYSTEM IS ALSO MOVING ACROSS SOUTHERN
WISCONSIN. MEANWHILE...SUNNY SKIES ARE PREVAILING OVER THE FORECAST
AREA...AND UPSTREAM AS WELL OVER SOUTH DAKOTA...NEBRASKA AND NORTHERN
IOWA/SOUTHERN MINNESOTA. AS A RESULT...FORECAST CONCERNS ARE
MINIMAL AND INCLUDE MAINLY TEMPERATURES.
TONIGHT...ARCTIC HIGH PRESSURE WILL BE SHIFTING FROM THE CENTRAL
GREAT PLAINS TO THE MID-MISSISSIPPI VALLEY AND SOUTHERN GREAT
LAKES. RATHER THIN LOW STRATUS DECK WILL GRAZE FAR NORTH-CENTRAL
WISCONSIN THIS EVENING. ELSEWHERE...SKIES ARE ANTICIPATED TO REMAIN
MOSTLY CLEAR. 1000-850MB WINDS ARE PROJECTED TO RANGE FROM 15 TO 20
KTS...WHICH IS TYPICALLY MARGINAL FOR DECOUPLING. BUT A RELAXING
PRESSURE GRADIENT WITH THE INCOMING SURFACE HIGH WILL SUPPORT WINDS
DROPPING OFF. THINK CENTRAL WISCONSIN WILL HAVE A HIGHER POTENTIAL
FOR THIS TO OCCUR...BUT DROPPED TEMPS EVERYWHERE SINCE IT WONT TAKE
VERY LONG FOR TEMPS TO TANK. LOOKING AT UPSTREAM OBS...TEMPS FELL TO
20 BELOW WHERE WINDS WENT CALM...BUT GENERALLY STAYED BETWEEN 5 AND
10 BELOW WHERE WINDS REMAINED 3-5 KTS. WILL KEEP TEMPS IN THIS
RANGE...WITH A FEW COLDER TEMPS IN THE COLD SPOTS.
MONDAY...HIGH PRESSURE WILL CONTINUE TO LIFT NORTHEAST TOWARDS THE
EASTERN GREAT LAKES. SHORTWAVE ACTIVITY MOVING EAST OVER ONTARIO
AND SOUTH-CENTRAL CANADA WILL PUSH A WEAK COLD FRONT ACROSS WESTERN
LAKE SUPERIOR INTO CENTRAL MINNESOTA. WILL SEE WARM ADVECTION AHEAD
OF THE FRONT WITH 850MB TEMPS WARMING TO THE LOW TEENS BELOW ZERO.
THIS WILL TRANSLATE TO A WARMER DAY DESPITE A VERY COLD START.
WENT WITH HIGHS IN THE MID TEENS TO NEAR 20. SHOULD SEE MOSTLY
SUNNY CONDITIONS FOR THE MORNING...THEN INCREASING CLOUDS MID TO
LATE AFTERNOON.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 224 PM CST SUN FEB 2 2014
LITTLE CHG TO THE EXPECTED EVOLUTION OF WX EVENTS SINCE YDA. FCST
AREA WL BE ON THE NRN EDGE OF CYCLONE HEADED THROUGH THE OHIO
VALLEY TOWARD THE MID-ATL STATES TUE NGT/WED. THE EXACT POSN OF
THE NRN EDGE OF THE PCPN SHIELD IS TOUGH TO GAUGE...SO KEPT CHC
POPS ACRS ABOUT THE SRN 1/2 OF THE FCST AREA WED. UNLESS THERE IS
SUDDENLY A BIG SHIFT IN THE TRACK OF THE SYSTEM /WHICH SEEMS
UNLIKELY AT THIS POINT/ THINK THE VERY MOST WE/D BE ABLE TO DO IS
SQUEEZE OUT AN INCH OR TWO OF SNOW OVER THE FAR SE PART OF THE
FCST AREA. KEPT POPS IN CHC CATEGORY FOR NOW.
ANOTHER SYSTEM IS LIKELY TO BE HEADED ENEWD FM THE PLAINS NEXT
WEEKEND. MODELS WERE FURTHER N WITH THAT SYSTEM...BUT THEN AGAIN
EARLY MODEL RUNS WERE TOO FAR N WITH YDAS SYSTEM AND WL LIKELY
END UP BEING TOO FAR N WITH THE SYSTEM FOR TUE NGT/WED INTIALLY AS
WELL.
TEMPS WL PROBABLY AVERAGE 8-16 F DEG BLO NORMAL. THATS
SIGNIFICANT...BUT NOTHING SPECIAL AFTER THE 2 BRUTALLY COLD SNAPS
BACK IN JANUARY. AS TYPICAL...OVERNIGHT LOWS WL DEPEND HEAVILY ON
CLDS AND WINDS. THE AIR MASS WL EASILY SUPPORT DOUBLE DIGIT BLO
ZERO MINS ON ANY NIGHTS WITH SEVERAL HRS OF CLR SKIES AND LGT
WINDS.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 537 PM CST SUN FEB 2 2014
ARCTIC HIGH PRESSURE WILL SHIFT EAST THROUGH THE STATE THIS TAF
PERIOD. AREA OF STRATUS AHEAD OF WEAK TROF MOVING THROUGH CANADA
TONIGHT (HIGH MVFR/VFR CIGS) SHIFTING THROUGH WESTERN LAKE
SUPERIOR REGION. FEW CLOUDS MAY MAKE IT INTO NORTHERN WI THIS
EVENING OTHERWISE MAINLY CLEAR SKIES EXPECTED.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......TE
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SYNOPSIS...
ISSUED AT 224 PM CST SUN FEB 2 2014
FAIRLY QUIET MID-WINTER WX WITH CONTINUED BELOW NORMAL
TEMPERATURES AND JUST SOME LIGHT SNOW OR FLURRIES AT TIMES.
THE FLOW OVER THE NERN PAC WL BECOME INCREASINGLY BLOCKY AS STG
POSITIVE HEIGHT ANOMALY GRADUALLY RETROGRADES TOWARD THE
DATELINE. THE FLOW DOWNSTREAM ACRS NOAM IS SPLIT...WITH SRN AND
NRN STREAMS UNDERCUTTING AND FLOWING ARND THE NERN PAC BLOCK
/RESP/ BEFORE MERGING BACK TOGETHER OVER THE ERN CONUS. THE FCST
AREA HAS BECOME POSITIONED WITHIN THE CONFLUENT ZONE BETWEEN THE
MERGING STREAMS...AND THAT SHOULD CONT FOR THE FCST PERIOD. THAT
WL DIRECT THE MAIN WX PRODUCING SYSTEMS ARND THE AREA TO THE N AND
S...LEADING TO FAIRLY TRANQUIL MIX-WINTER WX. EXPECT SOME LIGHT
SNOW/FLURRIES AT TIMES AS THE FCST AREA GETS GRAZED BY THE TAIL OF
NRN STREAM SHRTWVS OR THE NRN FRINGE OF SRN STREAM CYCLONES...BUT
THESE ARE NOT EXPECTED TO BE SIG PCPN EVENTS. TEMPS WL REMAIN WELL
BLO NORMAL...BUT NOT AS BRUTALLY COLD AS THEY WERE AT TIMES DURING
JANUARY.
&&
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 224 PM CST SUN FEB 2 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE CENTERED FROM THE CENTRAL MISSISSIPPI VALLEY TO THE CENTRAL
GREAT PLAINS EARLY THIS AFTERNOON. AN AREA OF LOW STRATUS IS MOVING
JUST NORTH OF DUE EAST OVER NORTHERN MINNESOTA AND THE SOUTHERN EDGE
MAY JUST BRUSH NORTH-CENTRAL WISCONSIN LATER THIS AFTERNOON. CIRRUS
FROM A SOUTHERN STREAM SYSTEM IS ALSO MOVING ACROSS SOUTHERN
WISCONSIN. MEANWHILE...SUNNY SKIES ARE PREVAILING OVER THE FORECAST
AREA...AND UPSTREAM AS WELL OVER SOUTH DAKOTA...NEBRASKA AND NORTHERN
IOWA/SOUTHERN MINNESOTA. AS A RESULT...FORECAST CONCERNS ARE
MINIMAL AND INCLUDE MAINLY TEMPERATURES.
TONIGHT...ARCTIC HIGH PRESSURE WILL BE SHIFTING FROM THE CENTRAL
GREAT PLAINS TO THE MID-MISSISSIPPI VALLEY AND SOUTHERN GREAT
LAKES. RATHER THIN LOW STRATUS DECK WILL GRAZE FAR NORTH-CENTRAL
WISCONSIN THIS EVENING. ELSEWHERE...SKIES ARE ANTICIPATED TO REMAIN
MOSTLY CLEAR. 1000-850MB WINDS ARE PROJECTED TO RANGE FROM 15 TO 20
KTS...WHICH IS TYPICALLY MARGINAL FOR DECOUPLING. BUT A RELAXING
PRESSURE GRADIENT WITH THE INCOMING SURFACE HIGH WILL SUPPORT WINDS
DROPPING OFF. THINK CENTRAL WISCONSIN WILL HAVE A HIGHER POTENTIAL
FOR THIS TO OCCUR...BUT DROPPED TEMPS EVERYWHERE SINCE IT WONT TAKE
VERY LONG FOR TEMPS TO TANK. LOOKING AT UPSTREAM OBS...TEMPS FELL TO
20 BELOW WHERE WINDS WENT CALM...BUT GENERALLY STAYED BETWEEN 5 AND
10 BELOW WHERE WINDS REMAINED 3-5 KTS. WILL KEEP TEMPS IN THIS
RANGE...WITH A FEW COLDER TEMPS IN THE COLD SPOTS.
MONDAY...HIGH PRESSURE WILL CONTINUE TO LIFT NORTHEAST TOWARDS THE
EASTERN GREAT LAKES. SHORTWAVE ACTIVITY MOVING EAST OVER ONTARIO
AND SOUTH-CENTRAL CANADA WILL PUSH A WEAK COLD FRONT ACROSS WESTERN
LAKE SUPERIOR INTO CENTRAL MINNESOTA. WILL SEE WARM ADVECTION AHEAD
OF THE FRONT WITH 850MB TEMPS WARMING TO THE LOW TEENS BELOW ZERO.
THIS WILL TRANSLATE TO A WARMER DAY DESPITE A VERY COLD START.
WENT WITH HIGHS IN THE MID TEENS TO NEAR 20. SHOULD SEE MOSTLY
SUNNY CONDITIONS FOR THE MORNING...THEN INCREASING CLOUDS MID TO
LATE AFTERNOON.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 224 PM CST SUN FEB 2 2014
LITTLE CHG TO THE EXPECTED EVOLUTION OF WX EVENTS SINCE YDA. FCST
AREA WL BE ON THE NRN EDGE OF CYCLONE HEADED THROUGH THE OHIO
VALLEY TOWARD THE MID-ATL STATES TUE NGT/WED. THE EXACT POSN OF
THE NRN EDGE OF THE PCPN SHIELD IS TOUGH TO GAUGE...SO KEPT CHC
POPS ACRS ABOUT THE SRN 1/2 OF THE FCST AREA WED. UNLESS THERE IS
SUDDENLY A BIG SHIFT IN THE TRACK OF THE SYSTEM /WHICH SEEMS
UNLIKELY AT THIS POINT/ THINK THE VERY MOST WE/D BE ABLE TO DO IS
SQUEEZE OUT AN INCH OR TWO OF SNOW OVER THE FAR SE PART OF THE
FCST AREA. KEPT POPS IN CHC CATEGORY FOR NOW.
ANOTHER SYSTEM IS LIKELY TO BE HEADED ENEWD FM THE PLAINS NEXT
WEEKEND. MODELS WERE FURTHER N WITH THAT SYSTEM...BUT THEN AGAIN
EARLY MODEL RUNS WERE TOO FAR N WITH YDAS SYSTEM AND WL LIKELY
END UP BEING TOO FAR N WITH THE SYSTEM FOR TUE NGT/WED INTIALLY AS
WELL.
TEMPS WL PROBABLY AVERAGE 8-16 F DEG BLO NORMAL. THATS
SIGNIFICANT...BUT NOTHING SPECIAL AFTER THE 2 BRUTALLY COLD SNAPS
BACK IN JANUARY. AS TYPICAL...OVERNIGHT LOWS WL DEPEND HEAVILY ON
CLDS AND WINDS. THE AIR MASS WL EASILY SUPPORT DOUBLE DIGIT BLO
ZERO MINS ON ANY NIGHTS WITH SEVERAL HRS OF CLR SKIES AND LGT
WINDS.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1200 PM CST SUN FEB 2 2014
ARCTIC HIGH PRESSURE WILL BE IN CONTROL THROUGH THE END OF THE TAF
PERIOD. AREA OF LOW STRATUS CONTINUES TO MOVE EAST OVER NORTHERN
MINNESOTA AND WILL LIKELY PASS OVER FAR NORTHERN WISCONSIN LATE THIS
AFTERNOON INTO THIS EVENING. THERE MAY BE A FEW FLURRIES OUT OF
THIS STRATUS DECK...BUT NOT ANTICIPATING CIGS OR VSBYS TO FALL BELOW
VFR. CLOUDS WILL BE ON THE INCREASE AGAIN MONDAY AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......MPC
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1151 AM CST SAT FEB 1 2014
.UPDATE...THE WINTER WEATHER ADVISORY WAS CANCELLED ACROSS THE
ENTIRE AREA. RADAR TRENDS OVER THE PAST FEW HOURS HAVE SHOWN A
SIGNIFICANT WEAKENING IN THE OVERALL INTENSITY OF THE SNOW. THERE
ARE SOME BREAKS IN THE SNOW ACROSS THE AREA AS WELL. BEST UPWARD
VERTICAL MOTION FIELDS HAVE SHIFTED EAST OF THE AREA...OR REMAINED
TO THE SOUTH.
THERE IS SOME LINGERING 850MB TO 700MB FRONTOGENESIS RESPONSE
FIELDS...HELPING DRIVE SOME LIGHT SNOW BANDS IN THE WESTERN
PORTIONS OF THE AREA. LATEST HRRR RUN HAD ANY REMAINING LIGHT
SNOW/QPF FIELDS WEAKENING QUICKLY THIS AFTERNOON. WILL TREND DOWN
POPS THIS AFTERNOON...WITH ANY ACCUMULATIONS UP TO 1/2 INCH AT
BEST. THIS SHOULD NOT CAUSE SIGNIFICANT TRAVEL ISSUES. NEED TO
ADJUST TEMPERATURES DOWN IN THE NORTH THIS AFTERNOON AS WELL.
&&
.AVIATION/18Z TAFS/...EXPECT LIGHT SNOW AT TIMES INTO THE MID
AFTERNOON HOURS...BEFORE QUICKLY TAPERING OFF TO FLURRIES OR
ENDING BY LATER THIS AFTERNOON. ANY ACCUMULATIONS WILL BE UP TO
1/2 INCH AT BEST.
VISIBILITIES NEAR ALTERNATE MINIMUMS ARE EXPECTED EARLY THIS
AFTERNOON...THEN IMPROVING TO VFR LATER IN THE AFTERNOON. CEILINGS
WILL BOUNCE AROUND BETWEEN NEAR ALTERNATE MINIMUMS AND VFR IN THE
EASTERN SITES THIS AFTERNOON...WITH MADISON REMAINING VFR. LIGHT
NORTH WINDS WILL BACK NORTHWEST BY 00Z SUNDAY.
DRY CONDITIONS ARE EXPECTED TONIGHT AND SUNDAY...WITH NORTHWEST
WINDS LINGERING THROUGH THE PERIOD. THEY INCREASE IN MAGNITUDE A
BIT ON SUNDAY. CEILINGS WILL MIX OUT BY 09Z TO 10Z SUNDAY...WITH
MOSTLY SUNNY SKIES EXPECTED SUNDAY.
&&
.MARINE...NORTHWEST WIND GUSTS WILL APPROACH SMALL CRAFT ADVISORY
LEVELS AT TIMES LATER TONIGHT INTO SUNDAY. NO ADVISORY IS PLANNED
AT THIS TIME...AS THE GUSTS MAY NOT BE FREQUENT ENOUGH.
&&
.PREV DISCUSSION... /ISSUED 332 AM CST SAT FEB 1 2014/
SHORT TERM...
TODAY...FORECAST CONFIDENCE HIGH
THE MODEL CONSENSUS IS STRONG WITH THE SYSTEM MOVING THROUGH THIS
MORNING. THEY HAVE ALL CUT BACK ON PRECIP AMOUNTS. THIS IS A FAST
MOVING AND RATHER WEAK SYSTEM. THE SURFACE LOW IS WELL SOUTH...
MOVING OVER CNTRL/SOUTHERN ILLINOIS AT MID DAY...THEN TO LAKE ERIE
BY EVENING. THE AXIS OF HEAVIEST SNOW WILL BE WELL SOUTH ACROSS
ILLINOIS. DRY AIR WILL QUICKLY FLOW BACK IN AS THE NORTH WINDS
INCREASE WITH THE LOW HEADING EAST OF THE AREA. WE ARE SEEING SOME
DECENT INITIAL SNOWFALL EARLY THIS MORNING ACROSS THE SOUTH IN THE
LEADING WARM ADVECTION. BUT THAT PUSHES OFF QUICKLY. THE NEXT ROUND
WITH THE FORCING ASSOCIATED WITH THE MID LEVEL SHORTWAVE IS STARTING
TO SHOW UP UPSTREAM AND THE HEAVIEST IS CLEARING TAKING AIM AT AREAS
SOUTH OF WISCONSIN. LOOK FOR THE SNOW TO BE NEARLY WRAPPED UP IN THE
MADISON AREA BY NOON...BUT LIKELY PERSISTING THROUGH MID AFTERNOON
IN THE FAR SOUTHEAST.
SNOW AMOUNTS HAVE BEEN LOWERED BY 1 TO 2 INCHES AND HAVE PULLED THE
WINTER STORM WARNING FOR KENOSHA COUNTY AND PUT THEM INTO THE WINTER
WEATHER ADVISORY. LEFT THE REST OF THE ADVISORY ALONE. ADMITTEDLY...
SOME OF THE COUNTIES WILL BE ON THE LIGHT SIDE TO JUSTIFY THE
ADVISORY...BUT THE SNOW WILL MAKE IT SLICK OUT THERE. SO OUT OF AN
ABUNDANCE OF CAUTION WILL LET THE ADVISORY STAY AS ORIGINALLY
POSTED.
TEMPS WILL WARM WARM INTO THE 20S TODAY.
TONIGHT...FORECAST CONFIDENCE HIGH
LOOK FOR CLEARING SKIES AND FALLING TEMPS AS STRONG HIGH PRESSURE
BUILDS ACROSS THE AREA. TEMPS WILL DROP BACK DOWN INTO THE SINGLE
DIGITS EAST TO A FEW DEGREES BELOW ZERO WEST OF MADISON.
SUNDAY...FORECAST CONFIDENCE HIGH.
LOOK FOR BRISK NORTHWEST WINDS IN THE WAKE OF A MID LEVEL TROUGH
CROSSING THE UPPER GREAT LAKES ON SUNDAY. SKIES WILL CLEAR AS A HIGH
PRESSURE RIDGE SPREADS INTO SOUTHERN WI. MEANWHILE...A CORE OF COLD
AIR...850MB TEMP OF 14 TO 16 BELOW...WILL DROP INTO WISCONSIN DURING
THE DAY. DESPITE THE SUNSHINE...TEMPS WILL ONLY RISE TO 10 TO 15
DEGREES. WIND CHILLS WILL BE IN THE TEENS BELOW ZERO IN THE MORNING.
SUNDAY NIGHT...FORECAST CONFIDENCE MEDIUM.
THERE IS UNCERTAINTY IN HOW COLD IT WILL GET SUNDAY NIGHT. TEMPS
ALOFT WILL BE GRADUALLY WARMING AS HIGH PRESSURE SLIDES TO THE EAST
OVERNIGHT. HOWEVER... EXPECTING EFFICIENT RADIATIONAL COOLING SUNDAY
EVENING WHILE THE RIDGE AND COLD AIR ARE STILL OVERHEAD.
OVERALL...MODELS ARE TRENDING A LITTLE COLDER.
LONG TERM...
MONDAY AND MONDAY NIGHT...FORECAST CONFIDENCE HIGH.
RELATIVELY WARMER AIR WILL RETURN TO SOUTHERN WI BEGINNING MONDAY AS
THE HIGH CONTINUES TO SHIFT EAST. LOOK FOR HIGHS TO RISE INTO THE
UPPER TEENS TO AROUND 20. A HIGH-AMPLITUDE MID LEVEL TROUGH OVER THE
SOUTHWEST U.S. WILL BRING A RETURN OF MOISTURE INTO THE MIDWEST
MONDAY NIGHT...LEADING TO INCREASING CLOUDS. MIN TEMPS ARE TRENDING
WARMER WITH EACH MODEL RUN...BUT ARE STILL IN THE SINGLE DIGITS.
TUESDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE MEDIUM.
SOUTHERN WISCONSIN WILL BE WITHIN THE ENTRANCE REGION OF A
STRENGTHENING UPPER JET...VORTICITY ADVECTION WITH A NEGATIVELY
TILTED MID LEVEL TROUGH...AND ISENTROPIC LIFT TUESDAY AFTERNOON.
DECENT Q-VECTOR CONVERGENCE AND 700MB UPWARD MOTION WILL BE PRESENT.
BY TUESDAY EVENING...THE DEFORMATION ZONE ON THE NORTHWEST SIDE OF
THE SURFACE LOW TRACKING UP THE OHIO RIVER VALLEY WILL SWEEP ACROSS
SOUTHERN WI. USING CONSENSUS QPF AND SNOW RATIOS...IT LOOKS LIKE A
LONG-DURATION 4 TO 6 INCHES OF SNOW FOR THE SOUTHEAST HALF OF THE
MKX FORECAST AREA...POSSIBLY HIGHER TOWARD KENOSHA.
THIS SYSTEM HAS BEEN TRENDING NORTHWARD WITH EACH MODEL RUN...SO
KEEP AN EYE ON THE FORECASTS.
THURSDAY AND BEYOND...FORECAST CONFIDENCE MEDIUM.
IT LOOKS LIKE QUIET WEATHER FOR THURSDAY WITH ZONAL FLOW ALOFT. THEN
THE GFS AND ECMWF ARE SHOWING ANOTHER HIGH-MOISTURE SYSTEM BRUSHING
SOUTHERN WI NEXT SATURDAY.
AVIATION/12Z TAFS/...
EXPECT WIDESPREAD IFR CONDITIONS DUE TO SNOW THROUGH 18Z...THEN
IMPROVING CONDITIONS FROM WEST TO EAST ACROSS SOUTHERN WISCONSIN
THIS AFTERNOON. VFR CONDITIONS SHOULD RETURN TO KMSN BY LATE
AFTERNOON AND IN THE MILWAUKEE AREA BY MID EVENING. SNOWFALL
AMOUNTS HAVE BEEN LOWERED AS THE MAIN SURFACE LOW IS TRACKING
FARTHER SOUTH. MADISON SHOULD GET 2 TO 3 INCHES...MILWAUKEE ABOUT
3.5 AND AROUND 4 INCHES IN THE KENOSHA AREA. PEAK SNOWFALL WILL BE
BETWEEN 12 AND 18Z. WIND WILL NOT BE MUCH OF A FACTOR WHILE THE
SNOW FALLS...REMAINING BELOW 10KTS. WINDS WILL BE LIGHT OUT OF THE
NORTHEAST THIS MORNING...BACKING TO NORTH THEN NORTHWEST LATER THIS
AFTERNOON AND EVENING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1043 PM CST FRI JAN 31 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 233 PM CST FRI JAN 31 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE CENTERED OVER THE NORTHERN MISSISSIPPI VALLEY AND WESTERN
GREAT LAKES REGION. ARCTIC COLD FRONT STRETCHES FROM THE EASTERN
GREAT LAKES TO THE PANHANDLE OF TEXAS. THE BACK EDGE OF MID AND
UPPER LEVEL CLOUDS ARE PASSING ACROSS CENTRAL AND NORTHEAST
WISCONSIN WHERE TEMPS HAVE WARMED INTO THE SINGLE DIGITS ABOVE
ZERO. LOOKING UPSTREAM...NORTHERN STREAM ENERGY IS DIGGING OVER
SOUTH-CENTRAL CANADA...WHILE A SHORTWAVE WITHIN THE SOUTHERN STREAM
IS PRODUCING LOW PRESSURE OVER NEW MEXICO. AS THIS AREA OF LOW PRESSURE
MOVES EAST INTO THE PLAINS AND EVENTUALLY THE NORTHERN OHIO VALLEY
AND INTERACTS WITH THESE SHORTWAVES...PRECIP AND SNOW
CHANCES/IMPACTS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...ARCTIC HIGH PRESSURE WILL BE CENTERED ACROSS THE STATE AT
THE START OF THE EVENING...WITH ONLY SCT MID AND HIGH CLOUDS PASSING
OVER CENTRAL AND EAST-CENTRAL WISCONSIN. WINDS WILL BECOME LIGHT
DURING THE EVENING WHICH WILL SET UP A PERIOD OF GREAT RADIATIONAL
COOLING CONDITIONS UNTIL EARLY OVERNIGHT. TEMPERATURES SHOULD FALL
QUICKLY THIS EVENING AS A RESULT. HAVE DROPPED LOWS ACROSS N-C
WISCONSIN WHERE HAVE CONCERNS DIDNT GO COLD ENOUGH. MID AND HIGH
CLOUDS WILL BE INCREASING AFTER MIDNIGHT AS LOW PRESSURE DEVELOPS
OVER THE SOUTH-CENTRAL PLAINS. SNOW WILL BE LIFTING TO THE
NORTHEAST ALONG A STRENGTHENING WARM FRONT INTO SOUTHERN WISCONSIN.
THINK PRECIP WILL REMAIN SOUTH OF THE FORECAST AREA THROUGH
12Z...BUT WILL LEAVE A SMALL CHANCE IN CASE TIMING IS TOO SLOW.
TEMPS WILL GRADUALLY RISE LATE WITH THE INCOMING CLOUD COVER.
SATURDAY...LOW PRESSURE WILL TRACK OVER CENTRAL ILLINOIS TOWARDS
DETROIT. STRONG FGEN BAND ON THE NOSE OF THE LLJ WILL LEAD TO A
BAND OF HEAVY SNOW OVER NORTHERN ILLINOIS...FAR SE WISCONSIN AND
LOWER MICHIGAN...BUT MODELS POINT TOWARDS ENOUGH SATURATION ALONG
WITH QG FORCING FOR THE NORTHERN EDGE OF THE SNOW TO MOVE ACROSS
CENTRAL AND NORTHEAST WISCONSIN. PRECIP SHOULD BE KNOCKING ON THE
DOOR AROUND 12Z OR SHORTLY THEREAFTER BEFORE SPREADING NORTH ACROSS
ALL BUT NORTH-CENTRAL WISCONSIN. MODEL QPF ARE RELATIVELY
CONSISTENT AND USED A GENERAL BLEND AS IN INPUT INTO THE FORECAST.
WITH SNOW RATIOS OF 16 OR 17 TO 1...LOOKING AT ACCUMS OF 1 TO 3
INCHES SOUTH OF A MARSHFIELD TO MARINETTE LINE...HIGHEST OVER
MANITOWOC COUNTY. MAIN PERIOD OF LIGHT SNOW WILL OCCUR BETWEEN 9AM
AND 3PM...BEFORE PRECIP PULLS OUT LATE IN THE AFTERNOON. UNLIKE THE
PAST FEW STORMS...WINDS SHOULD BE RELATIVELY LIGHT WHICH WILL KEEP
BLOWING AND DRIFTING TO A MINIMUM. WITHOUT THE WIND RELATED
IMPACTS...HAVE DECIDED NOT TO ISSUE HEADLINES FOR THIS EVENT. HIGHS
WILL RANGE FROM THE MID TO UPPER TEENS.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 233 PM CST FRI JAN 31 2014
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE FORECAST
PERIOD AS RIDGE REMAINS FIRMLY ENTRENCHED ACROSS THE PACIFIC INTO
WESTERN NORTH AMERICA. THIS PATTERN SET UP WILL ALLOW FOR ARCTIC
AIR TO REMAIN ACROSS THE NORTHERN UNITED STATES. MAIN SNOW CHANCES
FOR THIS PERIOD WILL BE TUESDAY INTO WEDNESDAY MORNING AS SYSTEM
PASSES TO THE SOUTH. BELIEVE MODELS ARE TOO FAR SOUTH WITH SYSTEM
BASED ON 850MB THERMAL PROFILE WHICH SHOULD BRING SOME SNOW INTO
THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. ONLY CONCERN WILL
BE HIGH PRESSURE TO THE NORTH THAT WOULD ALLOW FOR DRIER AIR TO
FILTER SOUTHWARD AND HALT THE NORTHWARD ADVANCEMENT OF THE SNOW.
HAVE HIGHEST CHANCES FOR SNOW ACROSS THE SOUTHEAST. LATER SHIFTS
WILL NEED TO MAKE ADJUSTMENTS DEPENDING ON FINAL STORM TRACK AND
THE STRENGTH OF THE RIDGE TO THE NORTH.
MAIN ADJUSTMENTS TO TEMPERATURES DURING THE PERIOD WERE TO LOWER
MINIMUM TEMPERATURES A FEW DEGREES MOST NIGHTS AND TAILOR MAXIMUM
TEMPERATURE GRIDS TO DEPICT OUR USUAL WARM SPOTS.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1033 PM CST FRI JAN 31 2014
MID AND HIGH CLOUDS WILL BE INCREASING OVERNIGHT AS LOW PRESSURE
DEVELOPS ALONG ARCTIC FRONT SOUTH OF STATE. LIGHT PRECIPITATION
ON THE NORTHERN EDGE OF THIS SYSTEM WILL SPREAD INTO PARTS OF CENTRAL
AND NORTHEAST WISCONSIN DURING THE LATER MORNING HOURS. LOOKING
AT 1-2 INCHES FOR MUCH OF THE AREA SOUTH OF A GRB TO MFI LINE BY
THE TIME THE SNOW ENDS LATE TOMORROW AFTERNOON. HIGHEST AMOUNTS
WILL FALL OVER SOUTHERN WI. VSBYS TO FALL INTO MVFR/IFR LEVELS ONCE THE
SNOW ARRIVES. WEAK UPPER TROP MAY BRING MAINLY FLURRIES FURTHER
NORTH. SURFACE HIGH PRESSURE TO MOVE INTO STATE SATURDAY
NIGHT...FOR IMPROVING TREND.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......TE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1001 PM MST SUN FEB 2 2014
.UPDATE...
ISSUED AT 614 PM MST SUN FEB 2 2014
UPGRADED THE WINTER STORM WATCHES TO WARNINGS FOR OUR CENTRAL AND
SOUTHERN MOUNTAIN ZONES OF WESTERN COLORADO AND THE MOUNTAINS OF
SE UTAH. THIS WAS MAINLY DONE BECAUSE THE ONSET TIMES FOR SNOWFALL
WILL OCCUR DURING THE FIRST PERIOD...LATER TONIGHT. FORECAST
SNOWFALL AMOUNTS FOR THE WARNED MOUNTAIN ZONES STILL SEEM
REASONABLE.
WILL NEED TO TAKE A LOOK AT SOME OTHER ZONES WHERE WE PRESENTLY
HAVE BORDERLINE ADVISORY CRITERIA SNOWFALL AMOUNTS IN THE
FORECAST.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 308 PM MST SUN FEB 2 2014
TWO WEATHER SYSTEMS BLEND TOGETHER TO FORM THE NEXT WINTER STORM
TO IMPACT THE REGION. IN THE NEAR TERM...THE CIRCULATION OVER
CENTRAL CALIFORNIA IS PROGGED TO DROP SOUTHEAST INTO ARIZONA ON
MONDAY. A DEFORMATION ZONE DEVELOPS OVER WEST CENTRAL COLORADO
WHERE THE NRN AND SRN STREAM MEGRE. HIGH CLOUDS SPREAD FROM THE
SOUTHWEST THIS EVENING WITH THE MID LEVEL MOISTURE ARRIVING LATE
TONIGHT. THE RAP MODEL SHOWS THE THREAT OF SNOW IN THE WESTERN
SLOPE MOUNTAIN BEGINNING AFTER MIDNIGHT...BUT DYNAMICAL ASCENT
DOES NOT REACH SOUTHWEST COLORADO UNTIL MONDAY MORNING. SNOW
EXPANDS AND ENCOMPASSES THE MOUNTAIN AREAS BY NOONTIME MONDAY.
STATIC STABILITY IS LOW WITH MODEL DATA DEPICTING SOME CAPE
VALUES. THIS SUGGESTS THAT DEVELOPING SNOW CLOUDS WILL HAVE SOME
UPDRAFTS THAT SHOULD ENHANCE THE OROGRAPHIC AND DYNAMICAL
COMPONENTS. SURFACE PROGS SHOWS A BROAD AREA OF LOW PRESSURE
CENTERED OVER SOUTHWEST COLORADO. GIVEN THESE FACTORS...BELIEVE
THAT HOISTING THE WINTER STORM WATCH IS THE PRUDENT THING TO DO.
HIGH COUNTRY QPF VALUES SUPPORT AREAS OF WARNING CRITERIA BEING
REACHED BY TUESDAY AFTERNOON. EXPECT SOME SNOW TO EXPAND INTO THE
LOWER VALLEYS AND LATER SHIFTS MAY NEED TO CONSIDER ADDING WINTER
WEATHER ADVISORIES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 308 PM MST SUN FEB 2 2014
AN AMPLIFIED EASTERN PACIFIC/ALASKAN RIDGE IN THE WEST AND A STRONG
BERMUDA HIGH OVER THE CARIBBEAN WILL KEEP A BROAD...ACTIVE TROF
ACROSS MUCH OF THE CONUS THIS WEEK. THE PACIFIC JET IN THE BASE OF
THIS TROF WILL DIVE FROM THE PACIFIC NORTHWEST INTO THE DESERT
SOUTHWEST BEFORE ARCING BACK INTO THE UPPER MIDWEST THROUGH MUCH OF
THIS PERIOD. MORE ORGANIZED PIECES OF ENERGY MOVING THROUGH THE FLOW
WILL FORCE THE JET TO BECOME MORE CYCLONICALLY CURVED NEAR THE 4
CORNERS AT EACH END OF THE NEW WORK WEEK...WHICH WILL ADD SOME
ADDITIONAL ASCENT OVER OUR REGION. WITH THE JET TO OUR
SOUTH...COLD TEMPERATURES WILL BE IN PLACE. THIS COULD LEAVE HIGH
TEMPERATURES SOME 20 DEGREES BELOW NORMAL ACROSS PORTIONS OF THE
CWA. PIECES OF UNORGANIZED AND ORGANIZED ENERGY AND PACIFIC
MOISTURE PUSHED ALONG WITH THE JET WILL ALSO BRING PERIODS OF
SNOW...HEAVY AT TIMES...TO OUR CWA MOUNTAINS WITH VALLEYS LIKELY
TO SEE SOME WHITE STUFF AS WELL.
TUESDAY MORNING THE FIRST OF THE MORE ORGANIZED SYSTEMS WILL BE OVER
THE CWA. THE PACIFIC WAVE WILL HAVE MOVED INTO THE SOUTHERN PLAINS
BY SUNRISE...BUT THE UPSTREAM ARCTIC WAVE WILL BE SWINGING ACROSS
THE WYOMING AND NORTHERN COLORADO ROCKIES THROUGH THE DAY. 290K
MOISTURE TRANSPORT VECTORS SHOW THIS WAVE BRINGING IN ADDITIONAL
MOISTURE AND PWAT TOPS OUT AT NEAR .25 INCH. THIS IS HALF OF LAST
WEEK BUT WITH STRONGER INSTABILITY IN PLACE...IT SHOULD BE ABLE TO
CONTINUE THE THREAT OF MODERATE TO HEAVY MOUNTAIN SNOW SHOWERS
THROUGH THE DAY. CROSS SECTIONS SHOW NEG EPV NEAR MOUNTAIN LEVEL
WITH WESTERLY OROGRAPHICS HELPING TO RELEASE THIS INSTABILITY.
MODELS ALSO SUGGEST THIS WAVE WILL BE GIVING THE TRUE ARCTIC FRONT
A SHOVE SOUTHWARD INTO NORTHWEST COLORADO THROUGH THE AFTERNOON.
TEMPERATURES COULD VERY WELL BE DROPPING THROUGH THE MID TEENS
NORTH OF HIGHWAY 40 AFTER MID DAY. THIS FRONT WOULD ALSO SERVE AS
ADDITIONAL LOW LEVEL FOCUS FOR SNOW IN THE NORTHERN VALLEYS WHERE
DENDRITIC TEMPERATURES WILL BECOME MORE FAVORABLE FOR LOW DENSITY
SNOW PRODUCTION.
A SHORT LULL CAN BE EXPECTED LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING IN THE WAKE OF THIS WAVE. THETA SURFACES REVEAL PACIFIC
MOISTURE ENTRAINING IN THE FLOW OVER THE GREAT BASIN. FAVORABLE
OROGRAPHICS THROUGH A SATURATED DENDRITIC LAYER OVER THE HIGH
COUNTRY LOOKS TO KEEP LIGHT SNOW PROCESSES GOING...WITH AFTERNOON
INSTABILITY BOOSTING RATES AT TIMES. IT COULD BE A PROLONGED PERIOD
OF LIGHT SNOW FOR MANY AREAS BUT AT THIS TIME UNSURE OF IMPACTS
SUITED FOR WINTER HEADLINES. LARGE SCALE ASCENT...MOISTURE AND
INSTABILITY ALL GET A STRONG BOOST BY FRIDAY AS AGAIN WEST COAST
ENERGY MERGES OVER THE ROCKIES. THIS STORM HAS THE POTENTIAL TO
BRING ANOTHER ROUND OF SIGNIFICANT SNOW THE REGION THROUGH GOING
INTO THE WEEKEND. THIS STORM IS MUCH COLDER AND NOT AS MOIST BUT
TEMPERATURES SUGGEST THE LOWER DENSITY SNOW WILL BE EASIER TO PILE
UP. THERE IS ALSO A DEEPER FOCUS FOR ASCENT WITH A COLD FRONT
PUSHING THROUGH THE CWA FRIDAY EVENING...STAY TUNED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 959 PM MST SUN FEB 2 2014
CLOUDS AND SNOW WILL SPREAD INTO THE 4 CORNERS TONIGHT AND ACROSS
MUCH OF THE AREA ON MONDAY AS A COMPACT UPPER LOW CURRENTLY ALONG
THE CA COAST SWINGS ACROSS AZ ON MONDAY. VFR CONDITIONS WILL
PREVAIL UNTIL 09Z TONIGHT BEFORE DROPPING TO MVFR/IFR OVER THE SAN
JUANS MTNS BY 12Z-14Z MONDAY INCLUDING KTEX...AND THE CENTRAL
MOUNTAINS BY 18Z MONDAY. KASE/KRIL/KEGE/KMTJ MAY SEE PERIODS OF
MVFR CIGS AFTER 18Z MONDAY FROM PASSING -SHSN...AND KGJT HAS A 40%
CHANCE OF -SN. KVEL WILL REMAIN VFR THROUGH MONDAY EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO... WINTER STORM WARNING FROM 3 AM MONDAY TO 11 PM MST TUESDAY
COZ009-013-018-019.
WINTER STORM WARNING FROM 5 AM MONDAY TO 11 PM MST TUESDAY ABOVE
7500 FEET FOR COZ017.
WINTER STORM WARNING FROM 5 AM MONDAY TO 11 PM MST TUESDAY
COZ010-012.
UT...WINTER STORM WARNING FROM 5 AM MONDAY TO 11 PM MST TUESDAY ABOVE
7500 FEET FOR UTZ028.
&&
$$
UPDATE...JRP
SHORT TERM...PF
LONG TERM...15
AVIATION...JAD
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
335 AM EST MON FEB 3 2014
.SYNOPSIS...
LOW PRESSURE WILL LIFT NORTHEAST OF THE FORECAST AREA TODAY. THE
TRAILING COLD FRONT WILL MOVE THROUGH THE AREA THIS AFTERNOON. THE
FRONT WILL STALL JUST SOUTH AND EAST OF THE AREA TONIGHT. ANOTHER
COLD FRONT APPROACHING FROM THE WEST WILL MOVE THROUGH THE REGION
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DESPITE HIGH LOW-LEVEL MOISTURE...CLOUDINESS AND MIXING SHOULD
LIMIT FOG EARLY THIS MORNING.
LOW PRESSURE WILL BE LIFTING NORTHEAST OF THE FORECAST AREA
TODAY. THE ASSOCIATED COLD FRONT WILL CROSS THE AREA THIS
AFTERNOON. CONVERGENCE ALONG AND AHEAD OF THE FRONT SUPPORTS
SHOWERS. THE SPC WRF AND HRRR INDICATE SHOWERS MOVING INTO THE
WEST PART OF THE FORECAST DURING THE 900 AM TO 1000 AM TIME FRAME.
THE HIGH-RESOLUTION MODELS SHOW SHOWER COVERAGE DECREASING
THEREAFTER. SATELLITE TRENDS WITH THE COLDER CLOUD TOPS SHIFTING
WELL NORTH OF THE FORECAST AREA SUPPORT THE MODEL FORECAST OF A
LOSS OF UPPER-LEVEL LIFT. WE FORECASTED LIKELY POPS IN THE WEST
PART AND JUST CHANCE POPS IN THE EAST PART TODAY.
SHEAR WILL BE HIGH WITH H85 WINDS NEAR 40 KNOTS. HOWEVER...THE
SEVERE THREAT APPEARS LOW BECAUSE OF A LACK OF SURFACE-BASED
INSTABILITY. THE NAM KEEPS SURFACE-BASED LI/S GREATER THAN 1 AND
THIS APPEARS REASONABLE BECAUSE OF CLOUDINESS AND MID-LEVEL
CAPPING. THE NAM AND GFS DISPLAY RISING H5 HEIGHTS TODAY.
THE TEMPERATURE GUIDANCE WAS CONSISTENT. BASED ON THE GFS LAMP
AND THE NAM TIME-HEIGHT DISPLAYS AND EXPECTED MIXING BELIEVE SOME
WIND GUSTS NEAR 20 KNOTS WILL OCCUR THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE FRONT WILL STALL JUST SOUTH AND EAST OF THE FORECAST AREA
TONIGHT. A WEDGE-RIDGE PATTERN WILL DOMINATE BEHIND THE FRONT
TONIGHT THROUGH TUESDAY NIGHT. ISENTROPIC LIFT WILL SUPPORT
CLOUDINESS AND A CHANCE OF RAIN. WE USED THE GUIDANCE CONSENSUS
FOR THE POP FORECAST. THE RAIN CHANCE SHOULD GRADUALLY INCREASE
WITH CONTINUED ISENTROPIC LIFT. THE TEMPERATURE GUIDANCE WAS
CONSISTENT BUT IS LIKELY TOO WARM TUESDAY BECAUSE OF THE WEDGE
PATTERN.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE MODELS DISPLAY ANOTHER COLD FRONT MOVING INTO THE FORECAST
AREA WEDNESDAY. WE LEANED TOWARD THE HIGHER ECMWF MOS AND
FORECASTED LIKELY POPS BECAUSE OF CONVERGENCE ASSOCIATED WITH THE
FRONT. THE NAM AND GFS MOS INDICATED LOWER POPS AND THIS MAY BE
CORRECT BECAUSE OF A LACK OF SIGNIFICANT UPPER-LEVEL LIFT.
CONFIDENCE IN THE POP FORECAST WEDNESDAY IS LOW. THE MODELS SHOW
JUST WEAK COLD ADVECTION BEHIND THE FRONT WEDNESDAY AFTERNOON.
EXPECT BREAKS IN THE CLOUDINESS SO AFTER A RELATIVELY WARM START...
THE NAM...GFS...AND ECMWF MOS TEMPERATURES APPEAR REASONABLE WITH
HIGHS NEAR 70.
THE MODELS SHOW BRIEF DRYING BEHIND THE FRONT THURSDAY...BUT A
RETURN TO ISENTROPIC LIFT AND DEEPER MOISTURE FRIDAY AND SATURDAY.
THE MODELS SHOW LOW PRESSURE NEAR THE AREA SUNDAY.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
LLWS HAS DEVELOPED EARLY THIS MORNING AHEAD OF AN APPROACHING COLD
FRONT. CONDITIONS STILL MAINLY VFR ACROSS THE AREA BUT STILL
EXPECTING SOME MVFR CONDITIONS TO DEVELOP BEFORE SUNRISE.
DUE TO MIXING AND CLOUDS...ANTICIPATE ONLY MVFR CONDITIONS AT WORST
EARLY THIS MORNING. CIGS/VSBYS SHOULD IMPROVE SOMEWHAT AROUND 14Z
WITH SHOWERS MOVING INTO THE TAF SITES AHEAD OF AN APPROACHING COLD
FRONT. HAVE INDICATED SOUTHWEST WIND AROUND 10 KNOTS WITH GUSTS NEAR
20 KNOTS AHEAD OF THE COLD FRONT WHICH IS SCHEDULED TO CROSS THE TAF
SITES IN THE 18Z-21Z TIME-FRAME. BY THE END OF THE TAF
PERIOD...WINDS SHIFT TO THE NORTH AS WEDGE CONDITIONS DEVELOP FROM
NORTH TO SOUTH.
EXTENDED AVIATION OUTLOOK... MVFR OR LOWER CONDITIONS POSSIBLE
MONDAY NIGHT THROUGH WEDNESDAY...AND AGAIN ON FRIDAY. WEDGE
CONDITIONS DEVELOPING MONDAY NIGHT AND TUESDAY. ANOTHER COLD FRONT
WILL CROSS THE REGION WEDNESDAY. WEDGE CONDITIONS POSSIBLE AGAIN
FRIDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
325 AM EST MON FEB 3 2014
.SYNOPSIS...
LOW PRESSURE WILL LIFT NORTHEAST OF THE FORECAST AREA TODAY. THE
TRAILING COLD FRONT WILL MOVE THROUGH THE AREA THIS AFTERNOON. THE
FRONT WILL STALL JUST SOUTH AND EAST OF THE AREA TONIGHT. ANOTHER
COLD FRONT APPROACHING FROM THE WEST WILL MOVE THROUGH THE REGION
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DESPITE HIGH LOW-LEVEL MOISTURE...CLOUDINESS AND MIXING SHOULD
LIMIT FOG EARLY THIS MORNING.
LOW PRESSURE WILL BE LIFTING NORTHEAST OF THE FORECAST AREA
TODAY. THE ASSOCIATED COLD FRONT WILL CROSS THE AREA THIS
AFTERNOON. CONVERGENCE ALONG AND AHEAD OF THE FRONT SUPPORTS
SHOWERS. THE SPC WRF AND HRRR INDICATE SHOWERS MOVING INTO THE
WEST PART OF THE FORECAST DURING THE 900 AM TO 1000 AM TIME FRAME.
THE HIGH-RESOLUTION MODELS SHOW SHOWER COVERAGE DECREASING
THEREAFTER. SATELLITE TRENDS WITH THE COLDER CLOUD TOPS SHIFTING
WELL NORTH OF THE FORECAST AREA SUPPORT THE MODEL FORECAST OF A
LOSS OF UPPER-LEVEL LIFT. WE FORECASTED LIKELY POPS IN THE WEST
PART AND JUST CHANCE POPS IN THE EAST PART TODAY.
SHEAR WILL BE HIGH WITH H85 WINDS NEAR 40 KNOTS. HOWEVER...THE
SEVERE THREAT APPEARS LOW BECAUSE OF A LACK OF SURFACE-BASED
INSTABILITY. THE NAM KEEPS SURFACE-BASED LI/S GREATER THAN 1 AND
THIS APPEARS REASONABLE BECAUSE OF CLOUDINESS AND MID-LEVEL
CAPPING. THE NAM AND GFS DISPLAY RISING H5 HEIGHTS TODAY.
THE TEMPERATURE GUIDANCE WAS CONSISTENT. BASED ON THE GFS LAMP
AND THE NAM TIME-HEIGHT DISPLAYS AND EXPECTED MIXING BELIEVE SOME
WIND GUSTS NEAR 20 KNOTS WILL OCCUR THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE FRONT WILL STALL JUST SOUTH AND EAST OF THE FORECAST AREA
TONIGHT. A WEDGE-RIDGE PATTERN WILL DOMINATE BEHIND THE FRONT
TONIGHT THROUGH TUESDAY NIGHT. ISENTROPIC LIFT WILL SUPPORT
CLOUDINESS AND A CHANCE OF RAIN. WE USED THE GUIDANCE CONSENSUS
FOR THE POP FORECAST. THE RAIN CHANCE SHOULD GRADUALLY INCREASE
WITH CONTINUED ISENTROPIC LIFT. THE TEMPERATURE GUIDANCE WAS
CONSISTENT BUT IS LIKELY TOO WARM TUESDAY BECAUSE OF THE WEDGE
PATTERN.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE MODELS DISPLAY ANOTHER COLD FRONT MOVING INTO THE FORECAST
AREA WEDNESDAY. WE LEANED TOWARD THE HIGHER ECMWF MOS AND
FORECASTED LIKELY POPS BECAUSE OF CONVERGENCE ASSOCIATED WITH THE
FRONT. THE NAM AND GFS MOS INDICATED LOWER POPS AND THIS MAY BE
CORRECT BECAUSE OF A LACK OF SIGNIFICANT UPPER-LEVEL LIFT.
CONFIDENCE IN THE POP FORECAST WEDNESDAY IS LOW. THE MODELS SHOW
JUST WEAK COLD ADVECTION BEHIND THE FRONT WEDNESDAY AFTERNOON.
EXPECT BREAKS IN THE CLOUDINESS SO AFTER A RELATIVELY WARM START...
THE NAM...GFS...AND ECMWF MOS TEMPERATURES APPEAR REASONABLE WITH
HIGHS NEAR 70.
THE MODELS SHOW BRIEF DRYING BEHIND THE FRONT THURSDAY...BUT A
RETURN TO ISENTROPIC LIFT AND DEEPER MOISTURE FRIDAY AND SATURDAY.
THE MODELS SHOW LOW PRESSURE NEAR THE AREA SUNDAY.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
LLWS HAS DEVELOPED EARLY THIS MORNING AHEAD OF AN APPROACHING COLD
FRONT. CONDITIONS STILL MAINLY VFR ACROSS THE AREA BUT STILL
EXPECTING SOME MVFR/IFR CONDITIONS TO DEVELOP BEFORE SUNRISE.
MODERATE CONFIDENCE FOR IFR/LIFR CONDITIONS DEVELOPING 10Z-11Z AS
INDICATED BY MANY OF THE MODELS. RESTRICTION MAY BE PRIMARILY DUE TO
CIGS RATHER THAN VSBY. CIGS/VSBYS SHOULD IMPROVE TO MVFR AROUND 14Z
WITH SHOWERS MOVING INTO THE TAF SITES AHEAD OF AN APPROACHING
COLD FRONT. HAVE INDICATED SOUTHWEST WIND AROUND 10 KNOTS WITH GUSTS NEAR
20 KNOTS AHEAD OF THE COLD FRONT WHICH IS SCHEDULED TO CROSS THE TAF
SITES IN THE 18Z-21Z TIME-FRAME. BY THE END OF THE TAF PERIOD...WINDS
SHIFT TO THE NORTH AS WEDGE CONDITIONS DEVELOP FROM NORTH TO SOUTH.
EXTENDED AVIATION OUTLOOK... MVFR OR LOWER CONDITIONS POSSIBLE
MONDAY NIGHT THROUGH WEDNESDAY...AND AGAIN ON FRIDAY. WEDGE
CONDITIONS DEVELOPING MONDAY NIGHT AND TUESDAY. ANOTHER COLD FRONT
WILL CROSS THE REGION WEDNESDAY. WEDGE CONDITIONS POSSIBLE AGAIN
FRIDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
124 AM EST MON FEB 3 2014
.UPDATE...
ISSUED AT 124 AM EST MON FEB 3 2014
SNOW IS STARTING TO MIX IN FURTHER SOUTH NOW...WITH REPORTS OF MIXING
AS FAR SOUTH AS CAMPTON. HAVE MAINLY FRESHENED UP THE HOURLY
TEMPERATURES AND DEW POINTS TO MATCH THE LATEST TRENDS IN OBSERVATIONS.
WILL LEAVE EVERYTHING ELSE INTACT.
UPDATE ISSUED AT 1045 PM EST SUN FEB 2 2014
HAVE UPDATED THE FORECAST...INCLUDING SNOW AMOUNTS. THIS ALSO
INVOLVED ADDING IN SLEET AND POCKETS OF FREEZING RAIN FOR TIMES OF
LIGHTER PCPN THROUGH THE NEXT SEVERAL HOURS. THE CHALLENGE FOR THIS
FORECAST IS THAT THE NEXT SURGE OF PCPN WILL TELL THE TALE AND
DETERMINE THE SNOW AMOUNTS AS IT BRINGS IN COPIOUS MOISTURE AND A
COLDER COLUMN OF AIR. THE LATEST NAM12 STILL PRINTS OUT ENOUGH FOR A
HALF FOOT OF SNOW THROUGH THE WARNING AREA WITH A POTENTIAL CLOSE TO
DOUBLE DIGITS. AS SUCH...HAVE NOT HAD TO ADJUST THE SNOW TOTALS
MUCH...JUST A TOUCH MORE FOR NORTHERN PULASKI AND SLIGHTLY LOWER IN
THE SOUTHEAST PARTS OF THE WARNING BLOCK. THIS WILL BE A QUITE
INTERESTING NIGHT AS THAT SURGE MOVES THROUGH WITH COOLING CLOUD
TOPS NOW SHOWING UP ON SATELLITE AND A CONTINUED POTENTIAL FOR
THUNDER. STILL SEE SNOWFALL RATES APPROACHING 2 INCHES AS A DISTINCT
POSSIBILITY DURING A WINDOW BETWEEN 1 AND 5 AM ACROSS THE WARNED
AREA. THE UPDATED GRIDS...HEADLINES AND ZONES HAVE BEEN SENT WITH ALL
THIS IN MIND.
UPDATE ISSUED AT 730 PM EST SUN FEB 2 2014
23Z SFC ANALYSIS SHOWS A DEVELOPING AREA OF LOW PRESSURE RIDING
NORTHEAST INTO THE SOUTHERN APPALACHIANS. THIS HAS BENT THE WIND FLOW
AROUND TO THE NORTH AND NORTHEAST THROUGH THE CWA. ACCORDINGLY...
TEMPERATURES ARE FALLING INTO THE LOWER 30S IN THE NORTH AND INTO THE
MIDDLE 30S THROUGH THE BREADTH OF THE AREA WHILE A FEW 40S REMAIN
OVER THE FAR SOUTHEAST. THE LATEST OF SEVERAL WAVES OF PCPN IS
OVERSPREADING THE NORTHWEST PARTS OF EAST KENTUCKY WITH MOSTLY RAIN
BUT SOME REPORTS OF SLEET AND HIGHER RETURNS SEEN IN THE RADAR
IMAGERY. THE CURRENT FORECAST IS GENERALLY ON TRACK WITH THE
ADDITION OF MORE OF A SLOUGH ZONE FOR SLEET AND EVEN PATCHY FREEZING
RAIN. FOR THE MOST PART...SNOW WILL BE P-TYPE LATER THIS EVENING AND
EARLY OVERNIGHT FOR THE WARNING COUNTIES ONCE THE NEXT SURGE ARRIVES.
UNTIL THEN...THOUGH SLEET AND SNOW WILL MIX WITH RAIN DEPENDING ON
THE HEAVINESS OF EACH SHOWER.
THE NEXT SURGE WILL BRING HEFTIER QPF AND RESULT IN QUICKLY
ACCUMULATING SNOWS DUE TO THE ISOTHERMAL SOUNDINGS OVER THE NORTHWEST
HALF OF THE FORECAST AREA WHEN IT ARRIVES. RATES OF TWO INCHES AN
HOUR ARE POSSIBLE FROM THIS ALONG WITH ISOLATED POCKETS OF THUNDER.
TO THE SOUTHEAST...IT WILL BE MORE TRICKY WITH THE COLDER AIR
FILTERING IN BENEATH THE WARM NOSE MAKING PATCHY FREEZING RAIN AND
DRIZZLE A POSSIBILITY WHEN TEMPS APPROACH 32. HOWEVER...THIS WILL NOT
BE A HARD FREEZE SO ANY GLAZING IS EXPECTED TO BE CONFINED TO THE
ELEVATED SFC LIKE RAILINGS AND CAR HOODS/ROOFS RATHER THAN IMPACTING
THE ROADS. OF COURSE...THE USUAL CAVEATS OF BRIDGES AND OVERPASSES
APPLY. FOR THESE AREAS...A WINTER WEATHER ADVISORY IS IN EFFECT WITH
THE ICING POTENTIAL A COMPONENT TO THE HAZARD.
OF NOTE...NORTHERN PARTS OF PULASKI...LAUREL AND CLAY COUNTY MAY SEE
AMOUNTS APPROACHING WARNING CRITERIA PER THE LATEST HRRR AND 18Z
NAM12. WILL MONITOR THIS POTENTIAL FOR SIGNS THAT THE COLDER AIR
COLUMN MAKES IT TO THESE PARTS AHEAD OF FORECAST AND AFFECT OUR SNOW
TOTALS THERE ACCORDINGLY. FOR NOW WILL LEAVE ALL THE HEADLINES AS
THEY ARE AND HOLD PAT WITH THE ZONES...THOUGH DID FINE TUNE THE WX...
T...AND TD GRIDS THROUGH 06Z. THESE GRIDDED UPDATES HAVE BEEN SENT
TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 309 PM EST SUN FEB 2 2014
FRONTAL BOUNDARY CONTINUES TO SAG SOUTHWARD ACROSS EASTERN KENTUCKY
THIS AFTERNOON AND PRESENTLY EXTENDS FROM MARTIN COUNTY...BACK TO THE
SOUTHWEST TO MCCREARY COUNTY. THIS BOUNDARY SHOULD PUSH ON THROUGH
THE LAST OF EASTERN KENTUCKY OVER THE NEXT FEW HOURS WITH
TEMPERATURES BEGINNING THEIR RATHER QUICK DECENT. TEMPERATURES BEHIND
THE FRONT HAVE ALREADY FALLEN INTO THE LOW TO MID 30S ACROSS THE FAR
NORTH. THIS IS IN LINE WITH THE PREVIOUS FORECAST...SO OUR
TEMPERATURES SEEM TO BE RUNNING FAIRLY CLOSE TO EXPECTED VALUES.
MEANWHILE...PRECIPITATION IS ALREADY LOADING UP UPSTREAM...WITH
RADAR RETURNS RAMPING UP ACROSS SOUTH CENTRAL KENTUCKY. THIS
PRECIPITATION WILL OVERSPREAD EASTERN KENTUCKY OVER THE NEXT FEW
HOURS...WITH MAINLY RAIN EXPECTED AT THE ONSET. WITH TEMPERATURES
ALREADY INTO THE LOWER 30S IN THE NORTH...WE COULD SEE SNOW AT THE
ONSET. A STRONG FRONTOGENTICAL CIRCULATION IS EXPECTED TO DEVELOP
ACROSS EASTERN KENTUCKY TONIGHT...WITH IMPRESSIVE OMEGA EXPECTED
ACROSS THE NORTHERN HALF OF THE FORECAST AREA. A CROSS SECTION ACROSS
EASTERN KENTUCKY REVEALS A NEGATIVE AREA OF SATURATED EQUIVALENT
POTENTIAL TEMPERATURE...SUGGESTING SOME POSSIBLE ELEVATED THUNDER
THROUGH THE OVERNIGHT HOURS. ALL OF THIS POINTS TO SOME PRETTY
IMPRESSIVE SNOWFALL RATES AS THE TRANSITION FROM RAIN TO SNOW TAKES
PLACE. THUS...GIVEN THE EXPECT 0.75 TO 0.90 OF LIQUID MODELS ARE
PUTTING OUT ACROSS THE NORTH...A BAND OF 6 TO 9 INCHES OF SNOWFALL
CERTAINLY SEEMS POSSIBLE AND PERHAPS EVEN LIKELY. BASED ON UPSTREAM
TRENDS...IT APPEARS THE I-64 CORRIDOR SEEMS TO THE BE THE TARGET
GROUND FOR THE BEST SNOWFALL. PLAN TO INTRODUCE SOME THUNDER INTO THE
FORECAST GIVEN THE ELEVATED INSTABILITY. WILL ALSO INCREASE THE
WORDING TO HEAVY SNOW ACROSS THE NORTHERN AREAS. NO CHANGES PLANNED
TO CURRENT HEADLINES.
LOOKS LIKE WE SHOULD SEE A FAIRLY SHARP GRADIENT WITH SNOWFALL
TONIGHT AS THE THE COLD AIR BLEEDS IN FROM THE NORTHWEST...SLOWLY
CHANGING PRECIPITATION OVER. THIS CHANGEOVER MAY NOT OCCUR UNTIL VERY
LATE TONIGHT...IF AT ALL...WITH SOUTHEAST AREAS POSSIBLY STAYING RAIN
OR EVEN FREEZING RAIN. FREEZING RAIN SHOULD NOT BE A HUGE IMPACT
HOWEVER...AS TEMPERATURES SHOULD ONLY FALL TO JUST AROUND 32 BY 7 AM
MONDAY MORNING...AND WITH RECENT MILD WEATHER...MAY NOT BE A BIG
IMPACT. REGARDLESS...A FEW SLICK SPOTS WILL STILL BE POSSIBLE AND
PLAN TO RIDE WITH THE WINTER WEATHER ADVISORY. AREAS ALONG AND SOUTH
OF THE HAL ROGERS PARKWAY MAY ONLY SEE A DUSTING TO AN INCH OF
SNOWFALL.
PRECIPITATION WILL WIND DOWN MONDAY MORNING...BEFORE COMING TO AN END
ACROSS THE EAST BY MIDDAY. TEMPERATURES WILL LIKELY BE HELD DOWN
ACROSS THE NORTH WITH THE FRESH SNOW...WHILE AREAS IN THE SOUTH MAY
RECOVER BACK TO AROUND 40 BY THE AFTERNOON. BY MONDAY NIGHT...FRESH
SNOW COVER AND CLEARING SKIES WILL ALLOW A QUICK DROP OFF IN
TEMPERATURES ACROSS THE NORTH...WITH VALLEY LOCATIONS LIKELY FALLING
INTO THE LOW 20S FOR LOWS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 224 PM EST SUN FEB 2 2014
THE MODELS START OUT IN VERY GOOD AGREEMENT WITH A TROUGH ON THE
SOUTHERN STREAM EXTENDING SOUTH FROM COLORADO TO THE THE SONORA
DESSERT. THERE IS ANOTHER TROUGH EXTENDING FROM IDAHO TO UTAH ON THE
NORTHERN STREAM. A COLD FRONT EXTENDS FROM NORTHERN MICHIGAN TO
SOUTHWESTERN NEBRASKA ON THE NORTHERN STREAM AND ANOTHER FRONT LIES
ALONG THE GULF COAST. A LOW IS FORECAST TO FORM ON THE FRONT OVER
LOUISIANA ON TUESDAY MORNING. THE LOW WITH STRENGTHEN AND MOVE TO
THE NORTHEAST AS THE NORTHERN STREAM COLD FRONT ALSO DIP TO THE
SOUTH. THE UPPER LOWS LOOK LIKE THEY WILL BE PHASING AND THIS WILL
BRING A STRONG COLD FRONT ACROSS THE AREA ON TUESDAY. THE SURFACE
LOW THAT WAS ORIGINALLY OVER LOUISIANA...WILL PUMP SOME MOISTURE UP
AHEAD OF THE SYSTEM. THE MAIN LOW WILL EVENTUALLY PASS TO THE NORTH
OF THE AREA. THE COMBINATION OF THE PHASING UPPER TROUGHS AND THE
AVAILABLE MOISTURE WILL GIVE THE POTENTIAL FOR SOME SIGNIFICANT
RAINFALL WITH THIS SYSTEM THAT COULD RESULT IN SOME INITIAL
LOCALIZED FLOODING FOLLOW BY SOME HIGH RIVERS. AS THE SYSTEM MOVES
OUT OF THE AREA ON WEDNESDAY...THE RAIN WILL MIX WITH SNOW AND
THEN BECOME ALL SNOW AS A LAST GASP AS THE SYSTEM EXITS. VERY LITTLE
ACCUMULATION IS EXPECTED AS THE LAST OF THE SNOW MOVES INTO VIRGINIA
ON WEDNESDAY NIGHT. .
THE UPPER AIR BECOMES MORE ZONAL ON WEDNESDAY...HOWEVER BY FRIDAY
ANOTHER UPPER TROUGH WILL DROP INTO THE SOUTHWEST AND THE NEXT COLD
FRONT WILL ENTER INTO THE AREA ON FRIDAY AND REMAIN UNSETTLED
THROUGH THE END OF THE PERIOD. SOME LIGHT ACCUMULATIONS OF SNOW ARE
EXPECTED WITH THIS SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 124 AM EST MON FEB 3 2014
IFR OR WORSE CEILINGS AND VISIBILITIES WILL BE THE RULE THROUGH 12Z
ACROSS THE AREA...WITH RAIN...FREEZING RAIN...SLEET...AND SNOW...GRADUALLY
CHANGING OVER TO SNOW FROM NORTH TO SOUTH THROUGH 10Z. THE HEAVIEST
SNOW WILL ALIGN BETWEEN THE MOUNTAIN PARKWAY AND I-64...WITH AMOUNTS
DROPPING OFF QUICKLY TOWARDS THE HAL ROGERS PARKWAY AND HIGHWAY 80
CORRIDORS. PRECIPITATION WILL BE MOVING OUT FROM WEST TO EAST BETWEEN
12 AND 15Z...WITH CEILINGS IMPROVING TO MVFR DURING THE AFTERNOON.
WINDS WILL BE OUT OF THE NORTH AND NORTHEAST THROUGH THE
PERIOD...GENERALLY BETWEEN 5 AND 10 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 10 AM EST THIS MORNING FOR KYZ044-
050>052.
WINTER STORM WARNING UNTIL 11 AM EST THIS MORNING FOR KYZ058>060-
104-106-108-111.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR KYZ079-
080-083>088-110-113-115>120.
WINTER STORM WARNING UNTIL NOON EST TODAY FOR KYZ068-069-107-109-
112-114.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...KAS
LONG TERM...JJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
504 AM EST MON FEB 3 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EST MON FEB 3 2014
WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL NRN STREAM
MID/UPPER LEVEL FLOW THROUGH THE NRN GREAT LAKES AS A SHORTWAVE
TROUGH MOVES TO THE NORTH THROUGH NRN ONTARIO. AT THE SFC...A WEAK
GRADIENT AND LIGHT WINDS PREVAILED AS AN AREA OF ARCTIC HIGH PRES
BUILDS TOWARD THE SRN GREAT LAKES. THIS HAS ALLOWED TEMPS TO DROP
OFF INTO THE -10 TO -23 RANGE OVER INLAND PORTIONS OF WRN UPPER MI.
TEMPS HAVE RISEN QUICKLY TO AROUND ZERO OVER N CNTRL UPPER MI AS AN AREA
OF LOW CLOUDS MOVES THROUGH.
TODAY AND TONIGHT...SATELLITE TRENDS AND MODELS 900-850 MB RH FCST
SUGGEST THAT THE CLOUDS WILL DEPART THE CWA BY 12Z LEAVING MOSTLY
SUNNY SKIES FOR MUCH OF THE MORNING. CLOUDS SHOULD THEN INCREASE
AGAIN IN THE AFTERNOON AHEAD OF A SFC-850 MB TROUGH MOVING FROM MN
TOWARD UPPER MI. TEMPS SHOULD REBOUND INTO THE UPPER TEENS TO AROUND
20. THERE MAY ALSO BE SLIGHT CHANCE FOR SOME LIGHT SNOW SHOWERS OVER
CNTRL UPPER MI AS AN AREA OF 270K-275K ISENTROPIC LIFT (900-800 MB)
MOVES THROUGH THE AREA BTWN 21Z-03Z. OTHERWISE...THE EXTENSIVE ICE
COVER ON LAKE SUPERIOR WILL MINIMIZE THE POTENTIAL FOR ANY LES AS THE
LOW LEVEL WINDS VEER TO THE NW AND 850 MB TEMPS DROP INTO THE -15C TO
-18C RANGE OVERNIGHT. LINGERING LOW CLOUDS WILL KEEP TEMPS FROM
DROPPING OFF TOO FAR AS MIN READINGS FALL TO AROUND ZERO.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 419 AM EST MON FEB 3 2014
BENIGN WEATHER PATTER IS EXPECTED FROM TUE THROUGH SUN AS FLOW IS
MOSTLY ZONAL AND EXTENT OF ICE COVER ON LAKE SUPERIOR LIMITS LES
COVERAGE/CHANCES.
REALLY...NOT TOO OPTIMISTIC ON PRECIP CHANCES IN ANY PART OF THE
LONG TERM FORECAST PERIOD...WITH JUST LOW 30 POPS BEING THE HIGHEST
POP IN THE LONG TERM. TEMPS ARE EXPECTED TO CONTINUE TO BE BELOW
NORMAL WITH HIGHS GENERALLY IN THE UPPER POSITIVE SINGLE DIGITS TO
TEENS. THU LOOKS TO BE THE COLDEST DAY WITH HIGHS FROM THE LOW
POSITIVE SINGLE DIGITS W TO THE LOW TEENS E. MAIN CHANGE TO PREVIOUS
FORECAST WAS TO ADD SOME BLOW SNOW TO THE KEWEENAW PENINSULA THU AND
FRI. W-WSW WINDS LOOK TO GUST TO AROUND 25KTS AT THAT TIME...AND
WITH ICE COVERING MOST OF LAKE SUPERIOR...THE KEWEENAW IS ESPECIALLY
EXPOSED TO BLOWING SNOW. USED CONSENSUS OF GUIDANCE FOR THE LONG
TERM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1233 AM EST MON FEB 3 2014
ALTHOUGH SOME SC WITH HI END MVFR/LO VFR CIGS MAY IMPACT CMX FOR A
COUPLE HRS EARLY THIS MRNG...EXPECT A DRY WSW FLOW ON THE NRN FLANK
OF HI PRES MOVING THRU THE LOWER LKS TO BRING PREDOMINANT VFR
CONDITIONS TO ALL 3 SITES THRU THIS AFTN. A WEAK LO PRES TROF WL
ARRIVE THIS EVNG. GIVEN RATHER LIMITED AND SHALLOW MSTR...THE BEST
CHC FOR MVFR CONDITIONS WL BE AT CMX WITH A MORE PRONOUNCED UPSLOPE
W WIND COMPONENT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EST MON FEB 3 2014
QUIET PERIOD OF WEATHER EXPECTED FOR LAKE SUPERIOR THIS WEEK. GALES
ARE NOT EXPECTED. SOME OCCASIONAL FREEZING SPRAY WILL STILL BE POSSIBLE
OVER THE OPEN WATERS OF EASTERN LK SUPERIOR. LATEST SATELLITE
IMAGERY INDICATES EXTENSIVE ICE COVER ON THE LAKE CONTINUES TO
EXPAND...EVEN OVER EASTERN PORTIONS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
402 AM CST MON FEB 3 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM CST MON FEB 3 2014
TODAY AND TONIGHT...SOME TRAPPED MOISTURE HAS DEVELOPED IN THE
PLATTE VALLEY THIS MORNING NEAR KOGA/NEDOR CAM AT OGALLALA. THE SNOW
FIELD HAS DEFIED ALL MODEL PREDICTIONS AND MAINTAINED A WEAK SFC
HIGH PRESSURE RIDGE NORTHWEST THROUGH THE PANHANDLE. NOT EVEN THE
RAP13 CAPTURES THIS FEATURE THIS MORNING. SO DENSE FOG ADVISORY IS
IN PLACE FOR KEITH AND DEUEL COUNTIES UNTIL 15Z THIS AM.
A WARM FRONT IS DEVELOPING THIS MORNING BUT IT IS ACROSS ERN
COLO/NWRN KS. THIS FRONT IS EXPECTED TO LIFT NORTH INTO WRN NEB
LATER TODAY AS AN ARCTIC FRONT...CURRENTLY MOVING THROUGH EDMONTON
ALBERTA...MOVES INTO MT. THIS FRONT WILL MERELY RECYCLE COLD AIR
NORTH WITH SOUTHEAST WIND AND VERY LIMITED VERTICAL MIXING.
BUT THERE IS MORE. THE NAM...GEM REGIONAL...RAP13 AND HRRR POOL
MOISTURE ALONG THE WARM FRONT AND PRODUCE SNOW AS THE FRONT LIFTS
INTO NCNTL NEB THIS MORNING AND THIS AFTERNOON. THE NAM SUGGEST
FLURRIES WHILE THE RAP AND HRRR SHOW SNOW ACCUMULATIONS OF AN INCH
OR LESS. HMMM...GIVEN THAT THE MODELS ARE HAVING TROUBLE CORRECTLY
ESTABLISHING A WARM SECTOR ON THE SNOW COVER AND SKY CONDITIONS ARE
CURRENTLY VFR EXCEPT FOR GROUND FOG...THE FORECAST IS VERY UNCERTAIN
TODAY BUT WE WILL TRY A 30 POP FOR SNOW SHOWERS AS THE FRONT LIFTS
NORTH. FORECAST ERRORS COULD BE LARGE WITH THIS ONE.
FCST HIGHS TODAY RANGE FROM THE UPPER 20S ACROSS THE SOUTH AND WEST
TO LOWER 30S NORTH AND EAST WHERE NO SNOW IS ON THE GROUND.
FOR TONIGHT...GET READY. AN ARCTIC FRONT WILL MOVE THROUGH THE FCST
AREA. THE FRONT IS A SLOW MOVER AND SFC WINDS BACK AROUND AND BECOME
NORTHEAST PRODUCING UPSLOPE WINDS AND A RAPID INCREASE IN RELATIVE
HUMIDITY BELOW 700 MB. TEMPERATURES 850MB-700MB FALL TO AROUND -14C
BEHIND THE FRONT SUPPORTING SNOW GROWTH WHILE THE UPSLOPE WINDS
PRODUCE WEAK LIFT. SNOW CHANCES INCREASE TO AROUND 50 PERCENT BY 12Z
TUESDAY MORNING AND SNOWFALL AMOUNTS SHOULD BE LESS THAN AN INCH.
LOWS TONIGHT SHOULD RANGE FROM SINGLE DIGITS NORTH TO AROUND 15F
SOUTH AND EAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 402 AM CST MON FEB 3 2014
12Z TUESDAY AND BEYOND. THE FOCUS OF THE EXTENDED FORECAST
CENTERS ON A PROLONGED PERIOD OF BITTERLY COLD TEMPERATURES AND
THE POTENTIAL OF SNOW MID-WEEK. MEDIUM RANGE FORECAST MODELS
REMAIN IN GOOD AGREEMENT WITH THE HANDLING OF THE SOUTHERN STREAM
SHORTWAVE. THE WAVE WILL ROTATE FROM THE SOUTHERN ROCKIES OUT ONTO
THE PLAINS ON TUESDAY...ALLOWING FOR WIDESPREAD SNOW ACROSS THE
REGION. THE MODELS CONTINUE TO FOCUS THE HEAVIEST QPF AND BEST
SNOW POTENTIAL SOUTH AND EAST OF THE CWA WITH THE TRACK OF THE H5
LOW FROM SOUTHWEST KANSAS INTO FAR SOUTHEAST NEBRASKA. HOWEVER
THERE CONTINUES TO BE SUPPORT OF INCREASING DPVA AND WEAK UPGLIDE
TARGETING PORTIONS OF THE FORECAST AREA THROUGH THE DAY ON
TUESDAY. THE HEAVIEST ANTICIPATED QPF ACROSS OUR CWA WILL BE FOUND
FROM SW NEB THROUGH SOUTHERN CUSTER COUNTY...BUT AT THAT THE MODEL
CONSENSUS ONLY SUGGESTS ~0.15" TOTAL QPF /WHICH IS DEEMED TOO
HIGH/. PROXIMITY SOUNDINGS FROM THIS AREA REVEAL A FAIRLY
EFFICIENT SNOW PRODUCING PROFILE AS A LARGE COLUMN OF SATURATED
AIR WILL BE CO-LOCATED WITHIN OMEGA AND FAVORABLE TEMPERATURES OF
-10 TO -18C. USING A 15-17:1 SLR INDICATES TWO OR THREE INCHES OF
SNOW POSSIBLE BY WEDNESDAY MORNING FOR OUR SOUTHEASTERN ZONES.
FURTHER WEST...ACROSS THE EASTERN PANHANDLE AND MUCH OF THE
SANDHILLS REGION...LIGHT SNOW WILL BE POSSIBLE AS THE NORTHERN
STREAM USHERS A TROUGH ACROSS WYOMING AND MONTANA. QPF WILL BE
LIGHTER WITH THIS SYSTEM...BUT GIVEN THE HIGH SLR/S AND THE
POTENTIAL OF 12+ HOURS OF LIGHT SNOW...AN INCH WITH LOCALIZED
HEAVIER AMOUNTS IS POSSIBLE. IN ADDITION TO THE LIGHT
SNOW...NORTHERLY WINDS MAY CAUSE SOME LOCALIZED BLOWING SNOW WITH
REDUCED VISIBILITY. ATTM THE STRONGEST GUSTS /UP TO 25 MPH/
TUESDAY LOOK TO REMAIN ACROSS EASTERN PORTIONS OF THE FORECAST
AREA. SNOW PRODUCTION WILL TAPER OFF QUICKLY WEDNESDAY MORNING AS
DRY AIR IS PULLED SOUTH BEHIND THE PASSING WAVE AND FORCING
SPREADS EAST.
ONTO TEMPERATURES AND SLIGHT CHANCE POPS LATE WEEK...ARCTIC AIR WILL BE
IN PLACE ACROSS THE CWA ON TUESDAY WITH HIGHS OF ONLY 8-15 ABOVE
ZERO. THESE TEMPERATURES WILL BE WARM COMPARED TO THE OVERNIGHT AND
WEDNESDAY AS ARCTIC AIR CONTINUES TO FILTER SOUTHEAST THROUGH THE
HIGH PLAINS. BY WEDNESDAY MORNING...H85 TEMPERATURES OF MINUS 22 OR
COLDER WILL BE ATOP THE REGION...WITH WIDESPREAD SUB-ZERO SFC
TEMPERATURES ANTICIPATED. HIGHS ON WEDNESDAY WILL REMAIN IN THE
SINGLE DIGITS FOR ALL LOCATIONS ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA. OVERNIGHT WEDNESDAY AND EARLY THURSDAY SHOULD BE THE
COLDEST PERIOD OF THE EXTENDED...AND POSSIBLY THIS ENTIRE WINTER
SEASON. RIGHT NOW MODEL GUIDANCE IS INDICATING THE POTENTIAL OF
MINUS 5 TO MINUS 15 FROM EAST TO WEST RESPECTIVELY...WHICH MAY BE
WARM GIVEN THE PROJECTED LOCATION OF THE ARCTIC HIGH AND POTENTIAL
FRESH SNOWPACK. TRENDED THE FORECAST FOR THE WEDNESDAY THROUGH
FRIDAY MORNING TIMEFRAME TOWARD THE BCGEMREG /DUE TO ITS RECENT
PERFORMANCE/ AND THE ADJMEXBC AS THE GFS SEEMS TO BE HEADING IN THE
RIGHT DIRECTION. WITH THE BITTERLY COLD TEMPERATURES ANY AMOUNT OF
WIND WOULD ALLOW FOR CRITICALLY LOW WIND CHILL READINGS. WIND CHILL
ADVISORIES MAY BE NEEDED WEDNESDAY THROUGH THURSDAY MORNING.
TEMPERATURES SLOWLY MODERATE LATE WEEK INTO NEXT WEEKEND IN ADVANCE
OF THE NEXT TROUGH OF LOW PRESSURE ORGANIZING ACROSS THE WESTERN
STATES. THIS TROUGH IS SHOWN TO REMAIN PROGRESSIVE WITH MOST OF
IT/S ENERGY AFFECTING THE SOUTHERN PLAINS. FOR NOW WILL MAINTAIN
SLIGHT CHANCE POPS FRIDAY INTO SATURDAY. OTHERWISE TEMPERATURES
WILL SLOWLY MODERATE INTO THE WEEKEND...BUT REMAIN WELL BELOW
AVERAGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1124 PM CST SUN FEB 2 2014
HIGH CLOUDINESS WILL INCREASE OVERNIGHT AS AN UPPER LEVEL TROUGH
OF LOW PRESSURE APPROACHES THE ROCKIES. CEILINGS WILL LOWER FURTHER ON
MONDAY AS THE SYSTEM PUSHES EAST OF THE FOUR CORNERS INTO THE
CENTRAL AND SOUTHERN ROCKIES. BY MONDAY EVENING...CEILINGS WILL
APPROACH MVFR LEVELS WITH A SMALL THREAT FOR LIGHT SNOW ACROSS
NORTHERN NEBRASKA...WHICH MAY IMPACT THE KVTN TERMINAL AFTER 02Z
TUESDAY. VISBYS MAY DROP DOWN TO 4SM WITH ANY LIGHT SNOW WHICH
FALLS AT THE KVTN TERMINAL. WINDS OVERNIGHT WILL BE LIGHT AND
VARIABLE...SHIFTING TO THE SOUTHEAST AND EAST AT AROUND 10 KTS
MONDAY AND MONDAY EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 8 AM MST THIS MORNING FOR NEZ056-057.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
309 AM EST MON FEB 3 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA FROM THE NORTHWEST THIS
AFTERNOON ACCOMPANIED BY SHOWERS. THE FRONT WILL STALL SOUTH OF
THE AREA TONIGHT THEN RETURN NORTH AS A WARM FRONT LATE TUESDAY.
ANOTHER COLD FRONT WILL QUICKLY CROSS THE AREA LATE WEDNESDAY.
HIGH PRESSURE WILL BUILD IN FROM THE NORTH ON THURSDAY. A GULF
COAST STORM MAY BRING RAIN TO THE REGION LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM MONDAY...A COLD FRONT CURRENTLY EXTENDING ACROSS THE
SOUTHERN APPALACHIANS AND SOUTH ACROSS ALABAMA WILL SWEEP EAST...
CROSSING THE EASTERN CAROLINAS THIS AFTERNOON AND MOVING OFFSHORE
THIS EVENING. THIS FRONT IS BEING PUSHED BY A SHORTWAVE TROUGH
CURRENTLY OVER EASTERN ARKANSAS THAT WILL MOVE INTO WEST VIRGINIA
THIS EVENING. 1030 MB SURFACE HIGH PRESSURE OVER THE SOUTHERN GREAT
LAKES THIS EVENING WILL ATTEMPT TO BUILD SOUTH INTO THE CAROLINAS
BUT WILL HAVE ONLY LIMITED SUCCESS AS LOW PRESSURE DEVELOPING OVER
THE WESTERN GULF COAST LATE TONIGHT HOLDS THE FRONT IN PLACE ACROSS
SOUTHERN SOUTH CAROLINA.
UNSEASONABLE WARMTH IS EXPECTED TODAY DESPITE PLENTY OF CLOUD COVER
AND MORNING FOG. FOG MAY EVEN BECOME DENSE ENOUGH FOR AN ADVISORY
BEFORE ALL IS SAID AND DONE. THERE WILL BE A NARROW WINDOW LATE THIS
MORNING AND EARLY THIS AFTERNOON FOR TEMPERATURES TO SPIKE INTO THE
70S AS LOW CLOUDS AND FOG CLEAR BUT BEFORE A SHOT OF DEEPER SYNOPTIC
LIFT ARRIVES FROM THE WEST WITH MORE CLOUDS SCATTERED SHOWERS. IF
ALL WORKS AS PLANNED...WE SHOULD SEE TEMPERATURES SOAR INTO THE
LOWER TO MIDDLE 70S FOR A COUPLE OF HOURS...ABOUT 15 DEGREES ABOVE
NORMAL FOR THIS DATE. 850 MB TEMPS AS HIGH AS +13C THIS MORNING
CERTAINLY LEND SUPPORT TO THESE TEMPERATURES. UNLIKE YESTERDAY THE
MODELS ARE IN PRETTY GOOD AGREEMENT WITH THEIR DEPICTION OF THE
WEATHER TODAY AND TONIGHT. HOWEVER LIKE YESTERDAY THE LARGEST
POTENTIAL FOR ERROR IS AGAIN WITH TIMING THE BURNOFF OF LOW CLOUDS
AND FOG.
SCATTERED SHOWERS ASSOCIATED WITH A RIBBON OF 300-305K ISENTROPIC
LIFT (AND PERHAPS EVEN SOME MODEST CONVECTIVE INSTABILITY) WILL
SWEEP ACROSS THE AREA JUST AHEAD OF THE SURFACE COLD FRONT...
REACHING THE COAST BEFORE SUNSET. SUBSIDENCE ABOVE 700 MB SHOULD
PRODUCE A STRONG ENOUGH CONVECTIVE CAP TO PREVENT SHOWERS FROM
GROWING INTO DEEPER THUNDERSTORMS.
TONIGHT THE FRONT WILL STALL OFFSHORE AND ACROSS SOUTHERN SOUTH
CAROLINA. ISENTROPIC LIFT WILL WANE DURING THE EVENING HOURS...BUT
THEN SHOULD STRENGTHEN LATE AS DEEPENING LOW PRESSURE OVER THE
WESTERN GULF COAST STRENGTHENS OUR LOW LEVEL WIND FIELDS AND BEGINS
TO LIFT INCREASINGLY WARM/HUMID AIR NORTHWARD ACROSS THE BOUNDARY.
RAIN CHANCES SHOULD INCREASE LATE TONIGHT INTO THE DAY TUESDAY.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...TUE WILL BE CLOUDY AND COOL IN THE CAROLINAS
WITH HIGH PRESSURE RIDGING DOWN THE EAST COAST. ISENTROPIC LIFT AND
NEAR SATURATION OF THE LOW LEVELS WILL KEEP LIGHT RAIN A POSSIBILITY
TUE. WEDGE STARTS TO BREAK DOWN LATE TUE AS SOUTHERN STREAM
SHORTWAVE EMERGES FROM THE SOUTHWEST. MID LEVEL WAVE HELPS SURFACE
LOW DEVELOP ON A FRONT STALLED ALONG THE TX COAST TUE MORNING. THE
SURFACE LOW LIFTS NORTHEAST ACROSS THE LOWER MS VALLEY AND INTO THE
TN VALLEY TUE EVENING. AS THE LOW MOVES NORTHEAST IT DRAGS THE
FRONT/TROUGH STALLED OFF THE CAROLINA COAST NORTHEAST AS A WARM
FRONT. TIMING THE MOVEMENT OF THE FRONT WILL PLAY A ROLE IN
TEMPERATURES TUE AND TUE NIGHT. CURRENTLY IT APPEARS THE HIGH TEMP
ON TUE WILL OCCUR LATE IN THE DAY WITH THE LOW OCCURRING TUE
EVENING. ALONG THE COAST THE HIGH AND LOW TEMPS COULD END UP BEING
THE SAME. TEMPERATURES WILL STEADILY RISE TUE NIGHT ENDING UP AROUND
60 WED MORNING.
DESPITE ABUNDANT CLOUD COVER WED TEMPS WILL END UP WELL ABOVE CLIMO
WITH MANY AREAS RISING INTO THE 70S. A STRONG COLD FRONT WILL MOVE
ACROSS THE AREA LATE IN THE DAY...LIKELY ACCOMPANIED BY CONVECTION.
AHEAD OF THE FRONT SCATTERED SHOWERS WITH THE POTENTIAL FOR A FEW
RUMBLES OF THUNDER WILL BE POSSIBLE. ALTHOUGH MOISTURE WILL BE
ABUNDANT INSTABILITY IS LIMITED. IN ADDITION LOW LEVEL JET IS RATHER
WEAK...AND GROWING WEAKER AS THE DAY PROGRESSES. AT THIS POINT
STRONG STORMS SEEM LIKE A LONG SHOT LET ALONE ANYTHING SEVERE. BEST
PRECIP CHANCES WILL BE ALONG THE FRONT WHERE LOW LEVEL CONVERGENCE
CAN TAP INTO THE LIMITED INSTABILITY. THINK A BROKEN LINE OF
SOMEWHAT STRONGER CONVECTION...CONTAINING A LITTLE MORE
THUNDER...WILL MOVE ACROSS THE AREA EARLY WED EVENING. THIS ACTIVITY
STILL DOES NOT LOOK PARTICULARLY IMPRESSIVE AS FAR AS SEVERE WEATHER
IS CONCERNED...BUT WILL CONTINUE TO MONITOR.
STRONG COLD ADVECTION FOLLOWS THE FRONT WED NIGHT WITH TEMPERATURES
DROPPING INTO THE UPPER 30S TO AROUND 40. DEEP DRY AIR SPREADS OVER
THE REGION WED NIGHT THOUGH BOUNDARY LAYER MOISTURE AS WELL AS SOME
MOISTURE ABOVE 300 MB LINGERS THROUGH THE END OF THE PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...MAJORITY OF THE PERIOD WILL SEE UNSETTLED
WEATHER CONTINUE WITH WEDGE SETTING UP FRI AND LASTING THROUGH THE
END OF THE PERIOD. THU APPEARS TO BE THE ONLY DAY OF THE PERIOD
WHERE SUNSHINE WILL BE PREVALENT...THOUGH TEMPERATURES WILL STILL
END UP BELOW CLIMO. STRONG COLD ADVECTION IN THE WAKE OF THE COLD
FRONT LATE WED WILL CONTINUE INTO THU AFTERNOON BUT IN A WEAKENED
STATE. HIGHS THU WILL END UP AROUND 50 IN MOST AREAS WITH LOWS THU
NIGHT DROPPING INTO THE LOW TO MID 30S. TEMPS WED NIGHT MAY LEVEL
OUT AFTER MIDNIGHT...ASSOCIATED WITH AN INCREASE IN CLOUD COVER.
AS MENTIONED WEDGE SETS UP EARLY FRI AND HOLDS STRONG THROUGH THE
WEEKEND. DEEP SOUTHWEST FLOW ABOVE 3K FT WILL PUMP PLENTY OF
MOISTURE INTO THE REGION THROUGH SUN. INCREASING ISENTROPIC AS EARLY
AS MIDDAY FRI TAPS INTO DEEPER MOISTURE...GENERATING LIGHT RAIN IN
THE REGION. OVER THE WEEKEND A SOUTHERN STREAM SYSTEM WILL EMERGE
FROM THE SOUTHWEST. LOW PRESSURE WILL DEVELOP ALONG THE CENTRAL GULF
COAST LATE SAT AND LIFT NORTH THROUGH SUN. STILL UNCERTAIN IF THE
WEDGE WILL BREAK DOWN OR IF A TRIPLE POINT LOW WILL FORM ALONG OR
OFF THE CAROLINA COAST LATE IN THE PERIOD. EITHER SOLUTION WILL KEEP
THE REGION CLOUDY WITH INCREASED RAIN CHANCES...THOUGH TEMP
DIFFERENCE WOULD BE SIGNIFICANT. HAVE LOW CONFIDENCE THIS FAR IN
ADVANCE AND FOR NOW WILL MAINTAIN A WET FORECAST WITH TEMPS NEAR
CLIMO FOR THE WEEKEND.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...PATCHES OF DENSE FOG HAVE DEVELOPED INLAND TONIGHT...
WITH LIFR VSBYS EARLIER REPORTED AT KLBT AND KFLO. MEANWHILE...
SOUTHERLY WINDS ALONG THE COAST HAVE KEPT VSBYS FROM DROPPING BELOW
VFR LEVELS. THE GRADIENT TIGHTENS AND LOW LEVEL WINDS SHOULD
INCREASE BEFORE DAYBREAK...LIKELY HELPING VSBYS IMPROVE TO MVFR/IFR
LEVELS AS FOG LIFTS INTO MORE OF A STRATUS LAYER. 11-3.9U SATELLITE
IMAGERY SHOWS SEA FOG/STRATUS TO OUR SOUTH...WHICH THE HRRR DEPICTS
AS SPREADING UP THE COAST OVER THE NEXT SEVERAL HOURS.
THEREFORE...WILL STILL INCLUDE IFR CIGS/VSBYS FOR THE COASTAL TERMS
BY 09Z.
FCST SOUNDINGS INDICATE IFR CIGS MAY LINGER THROUGH THE MORNING
HOURS. LOW PRESSURE IN THE SOUTHEAST WILL APPROACH THE CAROLINAS
DURING THE DAY...AND SO WILL KEEP VCSH THROUGH THE AFTERNOON AS
SHOWERS DEVELOP AHEAD OF THE COLD FRONT. SOUTHWEST WINDS 10-15 KTS
WILL BECOME NORTHERLY AROUND 10 KTS FOLLOWING FROPA...WHICH WILL
OCCUR AFTER 21Z INLAND AND 00Z ALONG THE COAST. EXPECT POST-FRONTAL
MVFR/IFR CIGS TO DEVELOP TOWARD THE END OF THE TAF PERIOD...LOWEST
AT THE COASTAL TERMS.
EXTENDED OUTLOOK...EXPECT IFR CIGS WITH RAIN POSSIBLE ON TUESDAY.
MVFR/IFR CONDITIONS WITH SHOWERS ARE LIKELY ON WEDNESDAY AS A COLD
FRONT PUSHES THROUGH OUR CWA. VFR THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM MONDAY...A COLD FRONT EXTENDING FROM THE SOUTHERN
APPALACHIANS AND SOUTH ACROSS ALABAMA WILL SWEEP EAST...REACHING THE
COAST OF THE CAROLINAS LATE THIS AFTERNOON. INCREASING SOUTH-
SOUTHWEST WINDS AHEAD OF THE FRONT WILL BRING SUBTROPICAL MOISTURE
INTO THE AREA. AS THIS HUMID AIR CROSSES THE VERY COLD NEARSHORE
ATLANTIC WATERS...AREAS OF DENSE SEA FOG SHOULD CONTINUE THROUGH AT
LEAST THE MORNING HOURS. WIND DIRECTIONS TURNING MORE WESTERLY NEAR
THE FRONT THIS AFTERNOON SHOULD EVENTUALLY LEAD TO THE DISSIPATION
OF THE FOG.
AS WIND SPEEDS INCREASE TO 15-20 KT THIS MORNING...SEAS AWAY FROM
SHORE SHOULD BUILD TO 4-5 FEET. WITH SHORT WAVE PERIODS AND A LARGE
AREA OF 5 FOOT SEAS EXPECTED TO DEVELOP OUT BEYOND 5-10 MILES FROM
SHORE...AN EXERCISE CAUTION HEADLINE WILL BE TACKED ONTO THE
FORECAST THROUGH THE AFTERNOON HOURS.
THE COLD FRONT SHOULD PUSH OFFSHORE EARLY THIS EVENING WITH HIGH
PRESSURE OVER THE SOUTHERN GREAT LAKES BUILDING SOUTHWARD. NORMALLY
THIS WOULD PUSH THE FRONT DOWN INTO GEORGIA OR EVEN FLORIDA BUT LOW
PRESSURE DEVELOPING ALONG THE WESTERN GULF COAST SHOULD HOLD THE
BOUNDARY IN PLACE ACROSS SOUTHERN SOUTH CAROLINA...WITH N WINDS
TURNING NE AND CONTINUING THROUGH THE NIGHT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...NORTHEAST FLOW WILL DECREASE FROM 15 TO 20 KT AT
THE START OF THE PERIOD TO 10 TO 15 KT TUE EVENING AS COASTAL TROUGH
MOVES TO THE COAST. ONCE THIS FEATURE MOVES ONSHORE...TUE
NIGHT...EAST TO SOUTHEAST WINDS WILL DEVELOP. SPEEDS START OUT 10 TO
15 KT BUT INCREASE TO 15 TO 20 KT AND VEER TO SOUTHWEST BY WED
MORNING. A STRONG COLD FRONT WILL APPROACH FROM THE WEST DURING THE
DAY WITH WINDS INCREASING TO A SOLID 20 KT JUST BEFORE THE FRONT
REACHES THE COAST. FRONT IS QUICK TO MOVE OFFSHORE...PUSHING EAST OF
THE WATERS BY MIDNIGHT. PINCHED GRADIENT AND STRONG COLD ADVECTION
BEHIND THE FRONT WILL KEEP WINDS CLOSE TO 20 KT AS THEY VEER TO
FIRST WEST AND THEN NORTHWEST OVERNIGHT. WINDS WILL BE NORTH TO
NORTHEAST BY THE END OF THE PERIOD. SEAS 3 TO 5 FT ON TUE START TO
BUILD TUE NIGHT ONCE SOUTHERLY FLOW DEVELOPS. SEAS WILL LIKELY
EXCEED 6 FT DURING THE DAY WED AND IT CONTINUES TO APPEAR A SCA
HEADLINE IS LIKELY.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...NORTHEAST FLOW WILL REMAIN 15 TO 20 KT THROUGH
THE PERIOD. A COMBINATION OF HIGH PRESSURE BUILDING DOWN THE EAST
COAST AND A FRONT/TROUGH STALLED EAST OF THE WATERS WILL MAINTAIN A
PINCHED GRADIENT ALONG THE EAST COAST. EXTENDED PERIOD OF STRONGER
NORTHEAST FLOW WILL BUILD SEAS FROM 2 TO 4 FT ON THU TO 3 TO 5 FT
WITH ISOLATED 6 FT ON FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR AMZ250-
252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...BJR/TRA
AREA FORECAST DISCUSSION
NWS RALEIGH NC
237 AM EST MON FEB 3 2014
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL CROSS THE MIDDLE ATLANTIC
REGION TODAY. POLAR HIGH PRESSURE WILL THEN BUILD SOUTH TONIGHT AND
TUESDAY...IN ADVANCE OF ANOTHER LOW PRESSURE SYSTEM THAT WILL AFFECT
THE MIDDLE ATLANTIC STATES TUESDAY NIGHT AND WEDNESDAY.
&&
.NEAR TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 955 PM SUNDAY...
PRECIP STREAMING ALONG THE FRONTAL ZONE WEST OF THE MOUNTAINS WILL
EVENTUALLY SHIFT EAST INTO THE WESTERN PIEDMONT TONIGHT...ESPECIALLY
ONCE A SHORTWAVE OVER THE LOW MISSISSIPPI VALLEY LIFTS TO THE
TENNESSEE VALLEY BY 12Z. THE 00Z KGSO RAOB SHOWS THAT THERE IS
STILL A LOT OF DRY AIR EAST OF THE MOUNTAINS HOWEVER. THE 50KT
PREFRONTAL LOW-LEVEL JET ANALYZED UPSTREAM IS ADVECTING BETTER
MOISTURE OUR WAY...BUT ISENTROPIC FIELDS AND RADAR TRENDS SUGGEST
PRECIP WILL VERY MUCH BE FOCUSED OVER THE NORTHWEST PIEDMONT UNTIL
THE FRONT AND WEAK SURFACE LOW CROSS THE MOUNTAINS AROUND 15Z. THUS
HAVE TRIMMED POPS TO JUST SLIGHT CHANCE OVER THE EASTERN HALF OF THE
CWA. THE RAP STILL SHOWS A LITTLE ELEVATED INSTABILITY WORKING
NORTH INTO THE CWA LATE TONIGHT...BUT FORCING OUTSIDE OF THE
LLJ/WARM ADVECTION IS WEAK PRIOR TO THE ARRIVAL OF THE SHORTWAVE AND
FRONT...SO ANY THUNDER WILL BE VERY ISOLATED. OVER THER
EAST...LOWER DEWPOINT DEPRESSIONS AND AND THINNER HIGH CLOUDS MAY
ALLOW SOME PATCHY FOG TO DEVELOP OVER THE SANDHILLS AND COASTAL
PLAIN. LOWS ARE LIKELY TO OCCUR IN THE NEXT FEW HOURS BEFORE
SOUTHERLY FLOW PICKS UP AND THICKER CLOUD COVER KICKS IN. WILL MAKE
SOME ADJUSTMENTS TO LOWS BASED ON CURRENT READINGS...WITH MID 50S
WEST AND MID/UPPER 40S EAST.
MONDAY...
PRECIP WILL SHIFT EAST ACROSS THE CWA DURING THE DAY MONDAY
AS THE COLD FRONT PUSHES SOUTHEAST. THE BEST UPPER FORCING WILL
MOVE OFF TO THE NORTHEAST...LEAVING MAINLY LOW-LEVEL CONVERGENCE AND
POSSIBLY SOME WEAK INSTABILITY OVER THE SOUTH TO KEEP SHOWERS GOING.
EXPECT A SHARP DROP OFF IN PRECIP AMOUNTS...AROUND 0.75" NORTH TO
WELL UNDER 0.25" SOUTH. TEMPERATURES ACROSS THE NORTH WILL
INITIALLY FALL BEHIND THE FRONTAL PASSAGE DURING THE MORNING HOURS
AND THEN HOLD NEARLY STEADY INTO THE AFTERNOON...WHILE TEMPERATURES
COULD WARM WELL INTO THE MID TO UPPER 60S ACROSS THE SE BEFORE THE
ARRIVAL THE FRONT AND PRECIP COOLS TEMPERATURES BACK DOWN INTO THE
50S. -SMITH/CBL
MONDAY NIGHT:
A ~1030MB OVER THE OHIO VALLEY WILL BUILD EASTWARD INTO THE REGION
MONDAY EVENING/NIGHT AS THE FRONT SLIPS SOUTH AND EAST OF THE AREA.
COULD SEE A LULL IN PRECIP MONDAY EVENING BEFORE WE ALREADY TO START
TO HAVE IMPACTS FROM THE NEXT SYSTEM WITH A RESURGENCE OF SHALLOW
SOUTHERLY 295K ISENTROPIC UPGLIDE LATE..BETWEEN 06 TO 12Z...WITH
SOME PATCHY DRIZZLE POSSIBLE ACROSS THE ENTIRE FORECAST AREA. DO NOT
EXPECT P-TYPE CONCERNS...WITH LOWS IN THE MID 30S NORTH TO UPPER 30S
SOUTH. -CBL
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 200 AM MONDAY...
THE MAIN WEATHER HAZARD FOR EARLY TUESDAY HAS BEEN THE VERY LOW
POTENTIAL OF SOME LIGHT FREEZING DRIZZLE (IN THE FAR NW-N ONLY). AS
IT HAS LOOKED IN PREVIOUS RUNS... THIS RUN OF THE MODELS ESSENTIALLY
DEPICTS THE SAME (NO IMPACTS FROM WINTER WEATHER). HOWEVER... THE
EXPECTED HYBRID CAD WILL DEFINITELY PLAY A SIGNIFICANT ROLE IN
KEEPING TEMPS LOW IN THE DAMMING REGION TUESDAY THROUGH WEDNESDAY).
THE MAIN BULK OF THE COLD AIR IS FORECAST TO REMAIN TOO FAR NORTH OF
OUR REGION FOR ANY WINTER WEATHER IMPACTS.
THE MAIN STORM TRACK IS AGAIN EXPECTED TO BE WEST OF THE MOUNTAINS.
THE MAIN SURFACE WAVE IS EXPECTED TO DEVELOP OFF THE TX/LA COAST
AROUND 12Z/TUE THEN TRACK NE THROUGH THE TENNESSEE VALLEY 00Z/WED...
AND INTO NEW ENGLAND BY WED. THE TRAILING COLD FRONT WILL MOVE
ACROSS OUR REGION WEDNESDAY AFTERNOON AND EVENING. THIS STORM TRACK
WILL AGAIN KEEP THE SIGNIFICANT RAIN TO OUR WEST AND NORTH... AND
WILL PLACE A GOOD PORTION OF EASTERN AND SOUTHERN NC INTO THE WARM
SECTOR WEDNESDAY WHEN TEMPS SHOULD REACH NEAR 70 FROM FAYETTEVILLE
TO GOLDSBORO. BACK OVER THE PIEDMONT... A HYBRID CAD WILL LINGER
THROUGH THE FRONTAL PASSAGE WEDNESDAY AFTERNOON WITH LOW OVERCAST
CEILINGS... OCCASIONAL LIGHT RAIN/DRIZZLE... AND POOR VISIBILITIES.
TEMPERATURES BACK ON THE NORTHWEST SIDE OF THE LINGER CAD BOUNDARY
SHOULD BE A GOOD 20 DEGREES IF NOT MORE COOLER THAN IN THE SE. HIGH
IN THE TRIAD MAY STAY AT OR BELOW 50 WEDNESDAY.
WEAK ISENTROPIC LIFT WILL BRING LOW CLOUDS AND A CHANCE OF RAIN
THROUGHOUT THE DAY TUESDAY. IT APPEARS THAT THE MAIN CHANCE OF RAIN
WILL ARRIVE BETWEEN 13Z-15Z FROM SOUTH TO NORTH. HOWEVER... QPF
LOOKS TO BE LESS THAN 0.25 OF AN INCH.
SENSIBLE WEATHER... CLOUDY WITH A CHANCE OF RAIN FROM MID MORNING ON
TUESDAY. HIGHS ONLY UPPER 30S NORTH AND WEST TO AROUND 50 SE. LIGHT
RAIN OR DRIZZLE LIKELY MOST AREAS TUESDAY NIGHT WITH AREAS OF FOG.
LOWS HOLDING STEADY. AREAS OF FOG AND DRIZZLE WITH A SOME LIGHT RAIN
LIKELY WEDNESDAY. A CHANCE OF SHOWERS SE. HIGHS 50 NW TO 70 SE.
CLEARING WEDNESDAY NIGHT WITH LOWS IN THE 30S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 219 AM MONDAY...
A VERY ACTIVE PATTERN IS EXPECTED TO CONTINUE ACROSS THE UNITED
STATES THROUGH THE WEEKEND WITH SEVERAL MORE SYSTEMS TO AFFECT OUR
REGION AS WELL. HOWEVER... IT APPEARS THAT THE MAIN STORM TRACK MAY
HOLD TRUE AGAIN (GULF TO APPALACHIANS TO NEW ENGLAND) EVEN FOR THE
NEXT STORM SYSTEM PROJECTED BY LATE WEEK. IF THIS VERIFIES... THE
THE WINTER WEATHER CONCERNS WILL CONTINUE TO BE VERY LOW FOR CENTRAL
NC.
ONE THING TO KEEP IN MIND... THERE CONTINUES TO BE QUITE A SPREAD OF
SOLUTIONS WITH THE EXPECTED STORM TRACK AND THE POTENTIAL FOR COLD
AIR DAMMING DOWN THE EASTERN SEABOARD. ENSEMBLES SHOW THIS VERY WIDE
VARIETY OF SOLUTIONS WHICH RANGES FROM HARDLY ANY STORM TO A
NOR`EASTER. WITH SUCH SPREAD NOTED... WPC SUGGESTS USING A
COMPROMISE SOLUTION BETWEEN THE TWO ENSEMBLE MEANS FROM THE GEFS AND
THE EC. OF IMPORTANCE FOR THE EASTERN SEABOARD INTO NC... THE POLAR
JET FLOW ALSO SHOWS A LARGE SPREAD AND THIS WILL PLAY AN IMPORTANT
PART IN THE FORECAST AS WELL.
FOR NOW... WE WILL RELY ON THE EC ENSEMBLE MEAN AND TEH GEFS MEAN
PER WPC. RECENT 90-DAY VERIFICATION SHOWED THE ECENS MEAN AND GEFS
MEAN ARE THE BEST PERFORMING MODELS AT DAY 7 OVER THE CONUS. THIS
SOLUTION WOULD YIELD ANOTHER MILLER TYPE-B STORM TRACKING TOO FAR
INLAND FOR SNOW FOR CENTRAL NC... YET LEAVES OPEN THE POTENTIAL FOR
SOME WINTERY MIX IN THE PIEDMONT AT THE BEGINNING OF THE EVENT (IF A
PARENT COLD HIGH BECOMES POSITIONED OVER THE GREAT LAKES OR NEW
ENGLAND AND EXTENDS DOWN THE EASTERN SEABOARD FAR ENOUGH). TOO MAY
IF`S TO ADD ANYTHING FROZEN OR FREEZING INTO OUR FORECASTS LATE WEEK
OR FOR THE WEEKEND.
SENSIBLE WEATHER... THE COLD HIGH BUILDS IN FROM THE WEST THU.
MOSTLY SUNNY WITH HIGHS IN THE 40S. MAINLY CLEAR AND CHILLY THU
NIGHT WITH LOWS IN THE 20S TO LOWER 30S SE. INCREASING CLOUDS FRIDAY
WITH A CHANCE OF RAIN IN THE AFTERNOON. HIGHS IN THE 40S. A CHANCE
OF RAIN SAT INTO EARLY SUNDAY. LOWS IN THE 30S AND 40S. HIGHS IN THE
40S AND 50S NW/SE.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 215 AM MONDAY...
A LOW PRESSURE SYSTEM WILL TRACK QUICKLY ENE FROM WESTERN NC TO
OFFSHORE TIDEWATER THROUGH EARLY AFTERNOON. STRENGTHENING
SOUTHWESTERLY FLOW AHEAD OF THE LOW WILL CAUSE LOW LEVEL MOISTURE TO
INCREASE/LIFR-IFR CEILINGS AND MAINLY MVFR VISIBILITY RESTRICTIONS
TO DEVELOP ACROSS CENTRAL NC THIS MORNING. A PERIOD OF
RAIN...MODERATE TO BRIEFLY HEAVY TO THE NORTHWEST OF THE LOW
TRACK...WILL ALSO ACCOMPANY THE PASSING SURFACE LOW. LASTLY...THE
STRENGTHENING WINDS WILL ALSO PROMOTE THE DEVELOPMENT OF LOW LEVEL
WIND SHEAR...AS WINDS JUST ABOVE THE LIGHT SW FLOW AT THE SURFACE
WILL INCREASE TO NEAR 50 KTS AT 2000 FT. THE TRAILING COLD FRONT
WILL SWEEP SOUTHEASTWARD ACROSS OUR REGION DURING THE
AFTERNOON...WITH A FEW HOUR PERIOD OF MVFR CEILINGS POSSIBLE BEFORE
SCATTERING TO VFR LATE IN THE AFTERNOON AND THIS EVENING. ADDITIONAL
LOW CLOUDS WILL REDEVELOP IN DEVELOPING COLD AIR DAMMING LATE
TONIGHT AND EARLY TUESDAY...AS WARM AND MOIST AIR JUST ABOVE THE
SURFACE RIDES ATOP A POLAR SURFACE HIGH AT THE SURFACE.
OUTLOOK: COLD AIR DAMMING AND ASSOCIATED SUB-VFR CONDITIONS AND
CHANCE OF RAIN WILL CONTINUE THROUGH WED AFTERNOON...FOLLOWED BY VFR
CONDITIONS FOR THE END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...CBL/SMITH
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
229 AM EST MON FEB 3 2014
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL CROSS THE MIDDLE ATLANTIC
REGION TODAY. POLAR HIGH PRESSURE WILL THEN BUILD SOUTH TONIGHT AND
TUESDAY...IN ADVANCE OF ANOTHER LOW PRESSURE SYSTEM THAT WILL AFFECT
THE MIDDLE ATLANTIC STATES TUESDAY NIGHT AND WEDNESDAY.
&&
.NEAR TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 955 PM SUNDAY...
PRECIP STREAMING ALONG THE FRONTAL ZONE WEST OF THE MOUNTAINS WILL
EVENTUALLY SHIFT EAST INTO THE WESTERN PIEDMONT TONIGHT...ESPECIALLY
ONCE A SHORTWAVE OVER THE LOW MISSISSIPPI VALLEY LIFTS TO THE
TENNESSEE VALLEY BY 12Z. THE 00Z KGSO RAOB SHOWS THAT THERE IS
STILL A LOT OF DRY AIR EAST OF THE MOUNTAINS HOWEVER. THE 50KT
PREFRONTAL LOW-LEVEL JET ANALYZED UPSTREAM IS ADVECTING BETTER
MOISTURE OUR WAY...BUT ISENTROPIC FIELDS AND RADAR TRENDS SUGGEST
PRECIP WILL VERY MUCH BE FOCUSED OVER THE NORTHWEST PIEDMONT UNTIL
THE FRONT AND WEAK SURFACE LOW CROSS THE MOUNTAINS AROUND 15Z. THUS
HAVE TRIMMED POPS TO JUST SLIGHT CHANCE OVER THE EASTERN HALF OF THE
CWA. THE RAP STILL SHOWS A LITTLE ELEVATED INSTABILITY WORKING
NORTH INTO THE CWA LATE TONIGHT...BUT FORCING OUTSIDE OF THE
LLJ/WARM ADVECTION IS WEAK PRIOR TO THE ARRIVAL OF THE SHORTWAVE AND
FRONT...SO ANY THUNDER WILL BE VERY ISOLATED. OVER THER
EAST...LOWER DEWPOINT DEPRESSIONS AND AND THINNER HIGH CLOUDS MAY
ALLOW SOME PATCHY FOG TO DEVELOP OVER THE SANDHILLS AND COASTAL
PLAIN. LOWS ARE LIKELY TO OCCUR IN THE NEXT FEW HOURS BEFORE
SOUTHERLY FLOW PICKS UP AND THICKER CLOUD COVER KICKS IN. WILL MAKE
SOME ADJUSTMENTS TO LOWS BASED ON CURRENT READINGS...WITH MID 50S
WEST AND MID/UPPER 40S EAST.
MONDAY...
PRECIP WILL SHIFT EAST ACROSS THE CWA DURING THE DAY MONDAY
AS THE COLD FRONT PUSHES SOUTHEAST. THE BEST UPPER FORCING WILL
MOVE OFF TO THE NORTHEAST...LEAVING MAINLY LOW-LEVEL CONVERGENCE AND
POSSIBLY SOME WEAK INSTABILITY OVER THE SOUTH TO KEEP SHOWERS GOING.
EXPECT A SHARP DROP OFF IN PRECIP AMOUNTS...AROUND 0.75" NORTH TO
WELL UNDER 0.25" SOUTH. TEMPERATURES ACROSS THE NORTH WILL
INITIALLY FALL BEHIND THE FRONTAL PASSAGE DURING THE MORNING HOURS
AND THEN HOLD NEARLY STEADY INTO THE AFTERNOON...WHILE TEMPERATURES
COULD WARM WELL INTO THE MID TO UPPER 60S ACROSS THE SE BEFORE THE
ARRIVAL THE FRONT AND PRECIP COOLS TEMPERATURES BACK DOWN INTO THE
50S. -SMITH/CBL
MONDAY NIGHT:
A ~1030MB OVER THE OHIO VALLEY WILL BUILD EASTWARD INTO THE REGION
MONDAY EVENING/NIGHT AS THE FRONT SLIPS SOUTH AND EAST OF THE AREA.
COULD SEE A LULL IN PRECIP MONDAY EVENING BEFORE WE ALREADY TO START
TO HAVE IMPACTS FROM THE NEXT SYSTEM WITH A RESURGENCE OF SHALLOW
SOUTHERLY 295K ISENTROPIC UPGLIDE LATE..BETWEEN 06 TO 12Z...WITH
SOME PATCHY DRIZZLE POSSIBLE ACROSS THE ENTIRE FORECAST AREA. DO NOT
EXPECT P-TYPE CONCERNS...WITH LOWS IN THE MID 30S NORTH TO UPPER 30S
SOUTH. -CBL
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 303 PM SUNDAY...
AN ACTIVE SPLIT FLOW PATTERN WILL MAINTAIN AN UNSETTLED WEATHER
PATTERN ACROSS CENTRAL NC THIS PERIOD.
ON TUESDAY...A PARENT SURFACE HIGH (1030+ MB) WILL BE POSITIONED
OVER NEW ENGLAND...NOSING SWD ITO THE CAROLINAS. MEANWHILE A S/W IN
THE SOUTHERN STREAM WILL BE LIFTING ENE ACROSS TX INTO THE LOWER MS
VALLEY. THIS SYSTEM WILL ENHANCE SLY FLOW IN THE 925-850MB LAYER
AFTER 12Z TUESDAY...AND ESPECIALLY TUESDAY AFTERNOON. THIS FLOW WILL
PULL WARM MOIST AIR OVER THE COOL DRY STABLE AIRMASS NEAR THE
SURFACE...ESTABLISHING AN OVERRUNNING EVENT AND ASSOCIATED HYBRID
COLD AIR DAMMING EPISODE. EXPECT AREAS OF LIGHT RAIN TO DEVELOP
TUESDAY MORNING THEN SPREAD NORTH ACROSS THE REGION THROUGH THE
AFTERNOON AND EARLY EVENING HOURS. IF PRECIP WERE TO START PRIOR TO
15Z ACROSS THE TRIAD REGION...COULD SEE PRECIP START OUT AS PATCHY
FREEZING RAIN (PER PARTIAL THICKNESSES). HOWEVER MODEL TREND HAS
FAVORED A LATER STARTING TIME...DEVELOPING ACROSS THE SOUTH DURING
THE EARLY-MID MORNING HOURS THEN LIFTING NWD INTO THE NORTHERN
PIEDMONT LATE MORNING-EARLY AFTERNOON.
DUE TO EXPECTED ONSET OF CAD CONDITIONS...EXPECT TEMPS TO AVERAGE
WELL BELOW NORMAL. WHILE THIS IS REFLECTED IN MOS GUIDANCE...
GUIDANCE MAY STILL BE TOO WARM BY TWO CATEGORIES... ESPECIALLY
ACROSS THE NW PIEDMONT. MAX TEMPS UPPER 30S NW TO MID-UPPER 40S SE.
PRECIP SHOULD BE GENERALLY LIGHT AS MAIN LIFTING MECHANISM IS
ISENTROPIC LIFT AND LITTLE SUPPORT/LIFT FROM JET DYNAMICS.
MAIN THRUST OF ISENTROPIC LIFT WILL ADVANCE INTO VIRGINIA TUESDAY
EVENING. EXPECT THE WIDESPREAD RAIN ACROSS CENTRAL NC TO BECOME MORE
PATCHY...AND LIKELY BE MORE DRIZZLE THAN LIGHT RAIN BY LATE EVENING
INTO THE OVERNIGHT HOURS. MAIN SFC LOW ASSOCIATED WITH THE SOUTHERN
STREAM DISTURBANCE WILL LIFT ACROSS THE TN VALLEY WHILE A WEAKER
SECONDARY LOW DEVELOPS ALONG THE CAD BOUNDARY IN VICINITY OF OUR
COASTAL PLAIN. THIS LOW LIFTS NEWD AND EVENTUALLY BECOMES THE
PRIMARY LOW OFF THE JERSEY SHORE BY WEDNESDAY AFTERNOON. THIS LOW
WILL DRAG A SFC COLD FRONT ACROSS CENTRAL NC WEDNESDAY...EXITING THE
COASTAL PLAIN COUNTIES BY LATE AFTERNOON. WEDNESDAY WILL START OUT
WET WITH AREAS OF RAIN OR RAIN SHOWERS...TRANSITIONING TO MORE RAIN
EAST VERSUS WEST BY AFTERNOON AS THE FRONT CROSSES THE PIEDMONT. NW
FLOW BEHIND THE BOUNDARY WILL AID TO SCOUR OUT THE RESIDUAL CAD
AIRMASS. THIS WILL TRANSLATE TO WARMER TEMPS WEDNESDAY VERSUS
TUESDAY WITH HIGH TEMPS RANGING FROM UPPER 50S/60 NW TO UPPER 60S/70
SE.
DRIER AND MORE STABLE CONDITIONS WEDNESDAY NIGHT AS COLD CANADIAN
AIR BUILDS INTO CENTRAL NC FROM THE N-NW. MIN TEMPS NEAR 30 NW TO
NEAR 40 SE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 340 PM SUNDAY...
ACTIVE SPLIT FLOW PATTERN PERSIST INTO THE LONG TERM WITH MUCH
UNCERTAINTY FOR TEH FRIDAY INTO SATURDAY PERIOD.
COLD CANADIAN AIR WILL BE CENTERED OVER THE CENTRAL U.S. BUT EXTEND
EAST INTO THE MID ATLANTIC THEN SWD INTO THE CAROLINAS. THIS PATTERN
USUALLY SIGNALS VERY SHALLOW COLD DRY AIR MOVING INTO AND SETTLING
INTO THE FORECAST AREA. EXPECT TRANQUIL WEATHER THURSDAY THOUGH MUCH
COOLER WITH HIGH TEMPS MID 40S NW TO LOWER 50S SE.
A SERIES OF UPPER LEVEL DISTURBANCES WILL AFFECT THE SOUTHERN U.S.
FRIDAY THROUGH SUNDAY. THE FIRST SYSTEM APPEARS TO BE MINOR AND
WEAKENS AS IT GETS CLOSER TO THE CAROLINAS. ECMWF CONTINUES TO
SUGGEST PRECIP POSSIBLE LATE THU NIGHT INTO FRI MORNING WHILE GFS
KEEPS PRECIP WELL TO THE SOUTH. ISENTROPIC LIFT ANEMIC ON THE ECMWF
SO THINK THAT THE PRECIP IS OVERDONE. WILL KEEP THURSDAY NIGHT DRY
AND HAVE A SLIGHT-SMALL CHANCE OF RAIN OVER CENTRAL NC FRIDAY. IF
RAIN DOES MATERIALIZE EARLY ENOUGH IN THE WESTERN-NW
PIEDMONT...PRECIP MAY START OUT AS WINTRY MIX.
SFC RIDGE AXIS FROM A PARENT HIGH OVER SOUTHERN NEW ENGLAND WILL
BUILD INTO THE CAROLINAS FRIDAY NIGHT INTO SATURDAY. MEANWHILE A
STRONGER SYSTEM ALOFT WILL APPROACH FROM THE SW. THIS SYSTEM WILL
INDUCE ANOTHER OVERRUNNING EVENT...COMMENCES FRIDAY NIGHT INTO
SATURDAY. THIS WILL TRIGGER A CLASSICAL DAMMING EVENT. STILL MUCH
UNCERTAINTY TO THE EXTENT/DEPTH OF THE SFC BASED COLD DRY AIR.
PARTIAL THICKNESSES OFF THE COLDER GFS WOULD SUPPORT A WINTRY MIX
(SLEET/FREEZING RAIN) WHILE ECMWF SUGGEST A COLD RAIN. THIS FAR
OUT...FAVOR A COLD RAIN AND MAINTAIN A WATCH ON MODEL TRENDS NEXT
DAY OR TWO. UNSETTLED CONDITIONS EXPECTED INTO EARLY SUNDAY...THEN
GRADUAL IMPROVEMENT AS TEH SYSTEM LIFTS TO THE NE. SLIGHTLY BETTER
SUPPORT ALOFT WITH THIS SYSTEM SUGGEST HIGHER PRECIP AMOUNTS
COMPARED TO THE TUESDAY-WEDNESDAY SYSTEM. MAX TEMPS FRIDAY UPEPR 30S
NW TO MID 40S BE...AND LOWER 40S NW TO LOWER 50S SE SAT AND SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 215 AM MONDAY...
A LOW PRESSURE SYSTEM WILL TRACK QUICKLY ENE FROM WESTERN NC TO
OFFSHORE TIDEWATER THROUGH EARLY AFTERNOON. STRENGTHENING
SOUTHWESTERLY FLOW AHEAD OF THE LOW WILL CAUSE LOW LEVEL MOISTURE TO
INCREASE/LIFR-IFR CEILINGS AND MAINLY MVFR VISIBILITY RESTRICTIONS
TO DEVELOP ACROSS CENTRAL NC THIS MORNING. A PERIOD OF
RAIN...MODERATE TO BRIEFLY HEAVY TO THE NORTHWEST OF THE LOW
TRACK...WILL ALSO ACCOMPANY THE PASSING SURFACE LOW. LASTLY...THE
STRENGTHENING WINDS WILL ALSO PROMOTE THE DEVELOPMENT OF LOW LEVEL
WIND SHEAR...AS WINDS JUST ABOVE THE LIGHT SW FLOW AT THE SURFACE
WILL INCREASE TO NEAR 50 KTS AT 2000 FT. THE TRAILING COLD FRONT
WILL SWEEP SOUTHEASTWARD ACROSS OUR REGION DURING THE
AFTERNOON...WITH A FEW HOUR PERIOD OF MVFR CEILINGS POSSIBLE BEFORE
SCATTERING TO VFR LATE IN THE AFTERNOON AND THIS EVENING. ADDITIONAL
LOW CLOUDS WILL REDEVELOP IN DEVELOPING COLD AIR DAMMING LATE
TONIGHT AND EARLY TUESDAY...AS WARM AND MOIST AIR JUST ABOVE THE
SURFACE RIDES ATOP A POLAR SURFACE HIGH AT THE SURFACE.
OUTLOOK: COLD AIR DAMMING AND ASSOCIATED SUB-VFR CONDITIONS AND
CHANCE OF RAIN WILL CONTINUE THROUGH WED AFTERNOON...FOLLOWED BY VFR
CONDITIONS FOR THE END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...CBL/SMITH
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1235 AM EST MON FEB 3 2014
.SYNOPSIS...
A WARMING TREND WILL CONTINUE INTO MONDAY AS HIGH PRESSURE SLIDES
OFFSHORE. A COLD FRONT WILL ARRIVE FROM THE NORTH MONDAY...
ACCOMPANIED BY SHOWERS. THIS FRONT WILL STALL TO OUR SOUTH MONDAY
NIGHT BEFORE RETURNING NORTH AGAIN AS A WARM FRONT LATE TUESDAY. THE
NEXT COLD FRONT WILL SWEEP EAST ACROSS THE AREA WEDNESDAY. A GULF
COAST STORM MAY SPREAD RAIN INTO THE AREA NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM MONDAY...NO SIGNIFICANT CHANGES ARE NEEDED TO THE
FORECAST. 11-3.9 MICRON SATELLITE IMAGERY SHOWS THE LOW STRATUS AND
FOG MOVING NORTH INTO GEORGETOWN NOW...AND APPROACHING MYRTLE BEACH
BETWEEN 2-3 AM. PREVIOUS DISCUSSION FROM 1030 PM FOLLOWS...
FOG WAS PATCHY...BUT AT TIMES DENSE THIS EVE ACROSS SOME INLAND
LOCATIONS. MORE WIDESPREAD FOG WAS ADVECTING NORTH AND MAY MOVE INTO
PORTIONS OF THE FORECAST AREA OVERNIGHT. WILL CONTINUE TO MONITOR
TRENDS AS THERE IS SOME CONCERN FOR MORE WIDESPREAD DENSE
FOG...ESPECIALLY NEAR AND A FEW HOURS AFTER THE MIDNIGHT HOUR AS
DEWPOINT DEPRESSIONS ARE NEAR ZERO ACROSS MOST LOCATIONS. INCREASING
WINDS ABOVE THE BOUNDARY LAYER ARE EXPECTED TO ARRIVE TOWARD
MORNING. THIS WOULD SUGGEST A TENDENCY FOR FOG TO LIFT INTO A LOW
STRATUS NEARER TO DAYBREAK. WILL ALSO HAVE TO MONITOR DEVELOPING SEA
FOG. THIS FOG MAY MOVE ONTO THE COAST AND MAY BE DENSE DURING THE
LATE NIGHT HOURS AND ON MONDAY ALONG THE IMMEDIATE COAST.
SOME OF THE HIGHER RESOLUTION MODELS ARE INDICATING SOME SHOWERS MAY
DEVELOP ACROSS THE AREA NEAR DAYBREAK WITH INLAND AREAS PERHAPS
SLIGHTLY FAVORED AS COMPARED TO MORE COASTAL LOCATIONS. STILL...WILL
KEEP POPS IN THE SLIGHT CHANCE CATEGORY GIVEN THE RESIDUAL DRY AIR
ABOVE 1500 FT OVERNIGHT.
TEMPS WILL STABILIZE IN THE MID AND UPPER 40S THIS EVE AND THEN
BEGIN RISING OVERNIGHT AS WARM AIR ADVECTION INCREASES AND HIGHER
WINDS ALOFT REACH THE AREA AHEAD OF UPSTREAM TROUGH.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...WAVE OF LOW PRESSURE RIDING UP THROUGH THE
CAROLINAS MONDAY MORNING WILL DRAG A COLD FRONT ACROSS THE COASTAL
CAROLINAS LATER ON MONDAY AS IT LIFTS OFF TO THE NORTHEAST. WILL
REMAIN IN WARM AND MOIST AIR MASS AHEAD OF THE FRONT THROUGH THE
FIRST HALF OF THE DAY. TEMPS AND DEWPOINTS WILL RISE STEADILY
THROUGH EARLY AFTERNOON AND SHOULD REACH NEAR 70 FOR TEMPS AND UP
TO MID 50 TO AROUND 60 DEWPOINTS. THIS INCREASED INSTABILITY WILL
LEAD THE WAY TO POTENTIAL FOR SHOWERS BUT WITH UPPER LEVEL SUPPORT
WELL TO THE NORTH AND WEST OF AREA...EXPECT ONLY ISOLATED. MAY BE
TRICKIER IF FOG LIFTS AND SUNSHINE INCREASES BUT IT LOOKS LIKE FOG
AND CLOUDS SHOULD BE AROUND THROUGH THE MORNING HOURS. LLJ UP TO
35 KTS OUT OF THE SOUTHWEST WILL CONTINUE THROUGH THE MORNING
HOURS BUT LOW LEVEL WINDS WILL BEGIN TO VEER AROUND TO THE W-SW BY
EARLY AFTN AS FRONT NEARS THE AREA. EXPECT SOME ENHANCED LIFT
ASSOCIATED WITH FRONT AS IT MOVES THROUGH AND MAY SEE SOME SHOWERS
WITH GUSTY WINDS. THE FRONT WILL REACH THE LUMBERTON AREA BY EARLY
AFTERNOON CONTINUING TO MOVE RAPIDLY SOUTHEAST MOVING OFF THE
GRAND STRAND BY LATE AFTN.
SHALLOW COOL AIR WILL MOVE IN BEHIND FRONT WITH A 20 DEGREE DROP
IN TEMPS THROUGH THE EVENING INTO OVERNIGHT IN CAA. THE COOL N-NE
WINDS BEHIND THE FRONT WILL BE OVERRUN BY W-SW WINDS ALOFT AS
RIDGE HOLDS ON OVER THE ATLANTIC. THIS WILL LEAD THE WAY TO
STRENGTHENING ISENTROPIC LIFT THROUGH THE NIGHT WITH LOW CLOUDS
AND POTENTIAL FOR RAIN INCREASING INTO TUES.
A MORE TYPICAL WEDGE TYPE SCENARIO WILL BE IN PLACE FOR TUESDAY AS
HIGH PRESSURE EXTENDS DOWN FROM THE NORTH THROUGH INLAND CAROLINAS
WHILE LINGERING FRONT/TROUGH REMAINS OFF THE COAST. EXPECT TO BE
PLAGUED WITH LOW CLOUDS AND RAIN THROUGH THE DAY ON TUES INTO TUES
NIGHT WITH SHALLOW COOL AIR IN PLACE KEEPING TEMPS IN THE 40S
MOST PLACES.
BY LATE TUES ANOTHER SYSTEM WILL MOVE UP FROM THE SOUTHWEST WITH
LOW TRACKING NORTHEAST INTO THE TENNESSEE VALLEY BY TUE EVENING.
AS THE LOW LIFTS OFF TO THE NORTHEAST IT WILL LIFT THE LINGERING
FRONT BACK NORTH AS A WARM FRONT TOWARD EARLY WED MORNING. WINDS WILL
COME AROUND TO THE SOUTH ONCE AGAIN LEADING TO INCREASING TEMPS
TOWARD WED MORNING IN INCREASED WAA.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...UNSETTLED WEATHER TO DOMINATE THE EXTENDED
WITH A SERIES OF STORM SYSTEMS PROGGED TO IMPACT THE AREA. FIRST OF
THESE OCCURS WEDNESDAY...AS A STRONG LOW PRESSURE MOVING ACROSS THE
MID-ATLANTIC DRIVES A POTENT COLD FRONT THROUGH THE CAROLINAS. WHILE
THE CWA WILL EXPERIENCE A BRIEF BUT SIGNIFICANT WARM-UP WITHIN THE
WARM SECTOR WEDNESDAY...TEMPS WILL COME CRASHING DOWN WEDNESDAY
NIGHT AS THE COLD FRONT RACES THROUGH. HIGHS IN THE 70S MOST
LOCATIONS WILL DROP WELL INTO THE 30S BY THURSDAY MORNING. IN
ADDITION...THERE APPEARS TO BE GOOD CONVECTIVE POTENTIAL AHEAD OF
THIS FROPA. AS IS TYPICALLY THE CASE IN WINTER...INSTABILITY WILL BE
LACKING...AND EVEN SHEAR LOOKS MARGINAL WEDNESDAY...SO STRONG
CONVECTION APPEARS UNLIKELY. HOWEVER...DO THINK THERE WILL BE ENOUGH
FORCING FOR TSTMS WED AFTN/EVE...AND CURRENT LIKELY POP WILL REMAIN
UNCHANGED.
COOL HIGH PRESSURE BUILDS INTO THE AREA THURSDAY...BEFORE RENEWED
WEDGE SETUP DEVELOPS FRIDAY. THIS CREATES AT LEAST ONE MOSTLY SUNNY
DAY THURSDAY...BUT TEMPS WILL BE WELL BELOW CLIMO THURSDAY...AND
POSSIBLY EVEN COOLER FRIDAY THANKS TO INCREASED CLOUD COVER...AS
THIS TEMPERATURE ROLLER-COASTER WE HAVE EXPERIENCED MUCH OF THE
WINTER CONTINUES.
NEXT WKND LOOKS QUITE UNSETTLED AS A STRONG NORTHERN STREAM IMPULSE
TRIES TO PHASE WITH SOUTHERN STREAM ENERGY AND CREATE AN EXPANSIVE
AREA OF LOW PRESSURE ACROSS THE EAST. WHILE INITIALLY SOME
OVERRUNNING PRECIP WILL BREAK OUT LATE FRIDAY INTO SATURDAY...MORE
SIGNIFICANT RAINFALL COULD DEVELOP AS TWO LOW PRESSURE SYSTEMS MOVE
TOWARDS THE AREA FOR THE WKND. WITH SUCH A COMPLICATED PRESSURE
PATTERN...AND IT BEING D6/D7...WILL NOT FOCUS ON DETAILS AT THIS
TIME...BUT WILL CONTINUE THE INHERITED TREND OF RAMPING POP UPWARDS
FOR NEXT WKND WITH TEMPS AROUND CLIMO.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...PATCHES OF DENSE FOG HAVE DEVELOPED INLAND TONIGHT...
WITH LIFR VSBYS EARLIER REPORTED AT KLBT AND KFLO. MEANWHILE...
SOUTHERLY WINDS ALONG THE COAST HAVE KEPT VSBYS FROM DROPPING BELOW
VFR LEVELS. THE GRADIENT TIGHTENS AND LOW LEVEL WINDS SHOULD
INCREASE BEFORE DAYBREAK...LIKELY HELPING VSBYS IMPROVE TO MVFR/IFR
LEVELS AS FOG LIFTS INTO MORE OF A STRATUS LAYER. 11-3.9U SATELLITE
IMAGERY SHOWS SEA FOG/STRATUS TO OUR SOUTH...WHICH THE HRRR DEPICTS
AS SPREADING UP THE COAST OVER THE NEXT SEVERAL HOURS.
THEREFORE...WILL STILL INCLUDE IFR CIGS/VSBYS FOR THE COASTAL TERMS
BY 09Z.
FCST SOUNDINGS INDICATE IFR CIGS MAY LINGER THROUGH THE MORNING
HOURS. LOW PRESSURE IN THE SOUTHEAST WILL APPROACH THE CAROLINAS
DURING THE DAY...AND SO WILL KEEP VCSH THROUGH THE AFTERNOON AS
SHOWERS DEVELOP AHEAD OF THE COLD FRONT. SOUTHWEST WINDS 10-15 KTS
WILL BECOME NORTHERLY AROUND 10 KTS FOLLOWING FROPA...WHICH WILL
OCCUR AFTER 21Z INLAND AND 00Z ALONG THE COAST. EXPECT POST-FRONTAL
MVFR/IFR CIGS TO DEVELOP TOWARD THE END OF THE TAF PERIOD...LOWEST
AT THE COASTAL TERMS.
EXTENDED OUTLOOK...EXPECT IFR CIGS WITH RAIN POSSIBLE ON TUESDAY.
MVFR/IFR CONDITIONS WITH SHOWERS ARE LIKELY ON WEDNESDAY AS A COLD
FRONT PUSHES THROUGH OUR CWA. VFR THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM MONDAY...11-3.9 MICRON SATELLITE IMAGERY SHOWS LOW
STRATUS AND DENSE FOG JUST GETTING INTO GEORGETOWN...AND SPREADING
NORTH ALONG THE COAST AT ABOUT 15 KNOTS. MARINERS IN THE MYRTLE
BEACH VICINITY CAN EXPECT A REDUCTION VISIBILITY BETWEEN 2-3
AM...WITH SEA FOG SPREADING NORTH TOWARD CAPE FEAR BY 4 AM. PREVIOUS
DISCUSSION FROM 1030 PM FOLLOWS...
SPECIAL SATELLITE IMAGERY SHOWS FOG SPREADING NORTH FROM AREAS TO
OUR SOUTH THIS EVE. AS DEWPOINTS CREEP THROUGH THE 50S IN A
SOUTHERLY FLOW...EXPECT THIS FOG TO ADVECT OR DEVELOP ACROSS OUR
WATERS. THUS HAVE ISSUED A DENSE FOG ADVISORY FOR THE WATERS AND
EXPECT THIS FOG TO RESTRICT THE VISIBILITIES TO 1 NM OR LESS LATE
TONIGHT AND INTO MON. WINDS ACROSS THE WATERS TONIGHT WILL BE FROM
THE SSW AND SW AT 10 KT OR LESS...BUT INCREASE TOWARD MORNING. SEAS
WILL ALSO REMAIN BETWEEN 2 AND 4 FT THROUGH THE NIGHT...INCREASING
ON MON.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...SOUTHWEST FLOW UP AROUND 15 KTS AHEAD OF
APPROACHING COLD FRONT WILL SHIFT ABRUPTLY TO THE N BEHIND COLD
FRONT BY MON EVE. THE SW PUSH AHEAD OF THE FRONT WILL PUSH SEAS UP
TO 3 TO 5 FT REACHING INTO PRECAUTIONARY CONDITIONS FROM MID
MORNING MONDAY UP LATE AFTN. MAY SEE SOME 6 FTERS PRODUCING
BORDERLINE SCA CONDITIONS BUT THE FLOW SHOULD HAVE A DECENT
WESTERLY COMPONENT KEEPING GREATEST SEAS JUST OUTSIDE OF LOCAL
WATERS...BEYOND 20 NM. NORTHERLY WINDS BEHIND FRONT WILL SHIFT
AROUND TO TO THE N-NE THROUGH TUES 10 TO 15 KTS IN CAA. GRADIENT
TIGHTENS UP THROUGH TUES AS HIGH PRESSURE RUNS DOWN THROUGH INLAND
CAROLINAS AND LINGERING FRONT/TROUGH BECOMES MORE WELL
DEFINED...SHIFTING CLOSER TO COAST BY TUES NIGHT. EXPECT NORTHEAST
WINDS TO CONTINUE TO COME AROUND BECOMING MORE ON SHORE AND
EVENTUALLY SOUTHERLY BY VERY END OF PERIOD INTO WED MORNING AS LOW
PRESSURE RIDES UP THROUGH THE TENNESSEE VALLEY DRAGGING THIS
LINGERING FRONT BACK NORTH. SEAS WILL REMAIN 3 TO 5 FT THROUGH
MOST OF THE PERIOD WITH RISE TOWARD THE END UP CLOSE TO 6 FT BY
WED MORNING.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 3 PM SUNDAY...PRE-FRONTAL REGIME TO BEGIN THE PERIOD AS A
WARM FRONT LIFTS NORTH OF THE WATERS AHEAD OF A COLD FRONT WHICH
WILL SWING THROUGH THE AREA WEDNESDAY NIGHT. THIS LEAVES GUSTY S/SW
WINDS MUCH OF THE DAY...AT SPEEDS OF 15-20 KTS...DRIVING SEAS TO 4-6
FT. A SMALL CRAFT ADVISORY CONTINUES TO LOOK LIKELY FOR MUCH OF
WEDNESDAY. SUDDEN WIND SHIFT OCCURS WITH FRONTAL PASSAGE WEDNESDAY
NIGHT...TURNING WINDS TO THE NW AND THEN NORTH BY THURSDAY
MORNING...WITH SPEEDS CONTINUING 15-20 KTS. WINDS BECOME NE THURSDAY
AS A WEDGE OF HIGH PRESSURE BUILDS DOWN THE COAST...AND THESE
PERSIST ON FRIDAY WITH SLIGHTLY WEAKER SPEEDS. ANY HEADLINES SHOULD
EXPIRE BY THURSDAY MORNING AS THE OFFSHORE FETCH CAUSES DECREASING
WAVE HEIGHTS...WITH SEAS BECOMING 2-4 FT THURSDAY AND FRIDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...DENSE FOG ADVISORY FROM 3 AM TO 1 PM EST MONDAY FOR
AMZ250-252-254-256.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...BJR/TRA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1127 PM CST SUN FEB 2 2014
.UPDATE...
ISSUED AT 1125 PM CST SUN FEB 2 2014
CLOUDS CONTINUE TO ADVECT EAST INTO THE AREA...AND TEMPS WILL
BECOME STEADY ONCE CLOUDS INCREASE. IT IS STILL CLEAR IN THE FAR
EAST AND SOUTHEAST...SO LOWS HERE WILL FALL BELOW ZERO.
ELSEWHERE...EXPECTING LOWS WITHIN A FEW DEGREES OF ZERO DEPENDING
ON IF ANY CLEAR SPOTS DEVELOP.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 328 PM CST SUN FEB 2 2014
MAIN CHALLENGE THROUGH THE PERIOD WILL BE TEMPERATURES AND CLOUD
COVER. GFS/NAM/ECMWF/GEM SYNOPTIC PATTERN IN GOOD AGREEMENT AND
WILL USE A BLENDED SOLUTION FOR THIS FORECAST PACKAGE.
21 UTC SURFACE ANALYSIS SHOWS A SURFACE TROUGH AXIS FROM DEVILS
LAKE TO BISMARCK WITH A COLD FRONT DRAPED FROM WILLISTON TO
DICKINSON. OVERCAST SKIES UPSTREAM FROM THE FRONT ACROSS NORTHEAST
MT INTO SASKATCHEWAN NOT WELL RESOLVED IN GLOBAL MODELS...BOTH
SHOWING CLOUDS BREAKING UP AS THEY MOVE EAST. SATELLITE IMAGERY
SHOWS FEW BREAKS AND WITH SURFACE RIDGE AXIS ESTABLISHING ITSELF
ACROSS THE FORECAST AREA OVERNIGHT...SEE NO REASON CLOUDS WILL
COMPLETELY DISSIPATE. WILL FOLLOW RAP 925 HPA RH OUTPUT WHICH
MOVES LOW CLOUDS ACROSS THE REGION THIS EVENING AND OVERNIGHT FOR
AT LEAST PARTLY CLOUDY SKIES. AS A RESULT...INCREASED CLOUD COVER
AND LOW TEMPERATURES TONIGHT DESPITE LOW-LEVEL COLD AIR ADVECTION
BEHIND THE FRONT. EXACT TEMPERATURES WILL DEPEND ON CLOUD COVER...
BUT STILL THINK MOST AREAS SHOULD DROP BELOW ZERO. NO NEED FOR
WIND CHILL HEADLINES TONIGHT WITH LIGHT WIND AROUND 5 TO 10 MPH.
MONDAY WILL SEE A MIX OF CLOUDS AND SUN WITH TEMPERATURES 5 TO 10
DEGREES COOLER THAN TODAY. LIGHT WEST-NORTHWEST FLOW WILL SHIFT TO
A MORE NORTHERLY DIRECTION AS 1040 HPA PLUS SURFACE HIGH TAKES UP
RESIDENCE ACROSS THE NORTHERN ROCKIES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 328 PM CST SUN FEB 2 2014
STORM TRACK TUESDAY/WEDNESDAY WILL REMAIN WELL SOUTH OF THE
FORECAST AREA WITH DRY NORTHERLY FLOW ACROSS THE NORTHERN PLAINS.
TEMPERATURES...HOWEVER...WILL CONTINUE TO BE 10 TO 20 DEGREES
BELOW EARLY FEBRUARY NORMALS UNDER PERSISTENT COLD AIR ADVECTION
REGIME. AFTERNOON HIGHS BOTH DAYS LIKELY TO BE WITHIN A FEW
DEGREES PLUS OR MINUS THE ZERO MARK WITH NIGHTTIME LOWS DIPPING
WELL INTO THE MID TEENS BELOW ZERO AND POSSIBLY COLDER ONCE AGAIN
INCREASING THE SEEMINGLY ENDLESS WIND CHILL THREAT.
WEDNESDAY NIGHT THROUGH SUNDAY...LITTLE CHANGE EXPECTED THROUGH THE
REMAINDER OF THE WORK WEEK. WEDGE OF SURFACE HIGH PRESSURE WILL
KEEP REGION DRY ALONG WITH TEMPERATURES CONTINUING WELL BLO AVERAGE.
MODELS DIVERGE NEXT WEEKEND ON SOLUTIONS BUT OVERALL LOOKS LIKE
STORM TRACK WILL REMAIN TO OUR SOUTH WITH FA REMAINING DRY BUT BLO
AVERAGE TEMPERATURES PERSISTING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1125 PM CST SUN FEB 2 2014
CIGS BETWEEN 3 AND 4KFT WILL INCREASE FROM WEST TO EAST THROUGH
THE OVERNIGHT...AND LIKELY PERSIST THROUGH MONDAY. MODELS ARE
DOING A POOR JOB WITH THESE CLOUDS...BUT HAVE KEPT IT CLOUDY IN
ALL AREAS ONCE THEY OVERSPREAD THE REGION.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...ROGERS
LONG TERM...ROGERS/VOELKER
AVIATION...DK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
458 AM EST MON FEB 3 2014
.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING SNOW TO THE SOUTHERN
AND EASTERN HALF OF THE STATE THIS MORNING. THEY HEAVIEST SNOWS
WILL FALL DURING THE MORNING COMMUTE LASTING THROUGH THE MORNING
HOURS. THOSE DRIVING IN THE CAPITOL DISTRICT...YORK AND LANCASTER
WILL NEED TO PREPARE FOR HAZARDOUS WINTER WEATHER DRIVING
CONDITIONS THIS MORNING. LOOK FOR IMPROVING CONDITIONS THIS
AFTERNOON AS HIGH PRESSURE BRIEFLY BUILDS ACROSS THE REGION. A
STRONGER AND MORE DYNAMIC WINTER STORM SYSTEM WILL IMPACT THE AREA
FROM TUESDAY NIGHT INTO WEDNESDAY...WITH THE POTENTIAL FOR
SIGNIFICANT SNOW AND ICE. DRY WEATHER AND BELOW NORMAL
TEMPERATURES SHOULD FINISH OUT THE SECOND HALF OF THE WEEK.
ANOTHER WINTER STORM SYSTEM MAY AFFECT THE AREA SOMETIME OVER THE
WEEKEND OR INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ANOTHER CHALLENGING FORECAST THIS WINTER. MAIN IMPACT FROM
DISTURBANCE MOVING INTO SOUTHERN ZONES EARLY THIS MORNING. ANY
RAIN WILL QUICKLY TURN OVER TO SNOW BEFORE SUNRISE. LATEST SHORT
TERM GUIDANCE INCLUDING LAST FEW HRRR RUNS SHOW A SHORT PERIOD OF
VERY HEAVY SNOWS ACROSS SE QUARTER OF CWA AND EXPANDED THE WSW
INTO THE HARRISBURG METRO AREA. MORNING COMMUTE WILL BE QUITE
TREACHEROUS ACROSS THIS AREA AS HEAVIEST SNOWS LOOK TO FALL DURING
THIS PERIOD. TOUGHEST PART OF FORECAST WILL BE FORECASTING SNOW
FOR THE NORTHERN EDGE OF THIS SYSTEM. RADAR TRENDS SHOW SHOWN A
SHARP CUTOFF IN INTENSITIES NORTH OF A CAMBRIA THROUGH CENTRE
COUNTY LINE. SNOW WILL REMAIN LIGHT NORTH OF THIS LINE
SIGNIFICANTLY LIMITING ACCUMULATIONS. WILL MONITOR CLOSELY IN CASE
THIS LINE SHIFTS NORTH...BUT SO FAR IT HAS NOT. WAVE WILL QUICKLY MOVE
EAST OF CWA BY THE EARLY AFTERNOON. SNOW WILL QUICKLY TAPER OFF
THOUGH TEMPERATURES WILL MOVE LITTLE THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
HIGH PRESSURE WILL BRING A QUIET NIGHT TO THE AREA WITH COLDER
LOWS GIVEN THE COLDER AIR MASS AND DECENT CONDITIONS FOR RADIATIONAL
COOLING.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
VERY ACTIVE AND CHALLENGING PERIOD OF WEATHER FOR THE EXTENDED
PERIOD. AFTER A QUIET WEATHER DAY ON TUESDAY HIGH PRESSURE QUICKLY
RETREATS NE AND THE NEXT WINTER STORM APPROACHES THE REGION
TUESDAY NIGHT AND WEDNESDAY. LATEST ENSEMBLE GUIDANCE SHOWS A
COLD STORM WITH A WIDE VARIETY OF PRECIPITATION SCENARIOS
POSSIBLE...DEPENDING ON THE TRACK OF THE SURFACE LOW. WIDE RANGE
OF MODEL GUIDANCE AND THE TRACK IS STILL UNCERTAIN. GEFS GUIDANCE
HAS THE BEST CHANCES OF LIQUID PRECIPITATION...INCLUDING FREEZING
RAIN OR PLAIN RAIN IN THE SOUTHEAST ZONES. IN THE CENTRAL ZONES INCLUDING
THE STATE COLLEGE AREA...PRECIP TYPES VERY CHALLENGING WITH
SIGNIFICANT SNOW FALL AND PERHAPS A PERIOD OF SLEET OR FREEZING
RAIN MIXED IN TO ADD TO THE COMPLEXITY OF THE FORECAST. AS YOU
HEAD TO THE NORTHERN ZONES THE CHANCES OF THE PRECIPITATION
REMAINING ENTIRELY AS SNOW INCREASE. FOR NOW HAVE NOT ISSUED ANY
HIGHLIGHTS FOR THIS STORM GIVEN THE LARGE AMOUNT OF UNCERTAINTY
THAT SILL EXISTS. AFTER THE STORM EXITS THE CWA ON WEDNESDAY
NIGHT THERE WILL BE A COUPLE DAY BREAK...THOUGH TEMPERATURES WILL
BE QUITE COLD TO END THE WORK WEEK...LIKELY BELOW FREEZING ACROSS
THE ENTIRE CWA. ANOTHER STORM SYSTEM IS FORECAST TO ARRIVE
SOMETIME NEXT WEEKEND...THOUGH TIMING IS STILL IN QUESTION. LATEST
GUIDANCE APPEARS TO PUSH IT BACK INTO THE SUNDAY OR MONDAY TIME
FRAME. THERMAL PROFILES AGAIN COLD WITH THE SYSTEM AND EXPECT
ANOTHER CHALLENGING FORECAST NARROWING DOWN THE EXPECTED IMPACTS.
STILL PLENTY OF TIME TO SEE HOW THAT EVOLVES.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
BANDS OF HEAVY SNOW ACROSS SOUTHERN PA AS OF 09Z.
EXPECT POOR CONDITIONS TO LINGER INTO LATE MORNING.
CONDITIONS WILL IMPROVE THIS AFT...AS STORM TRACKING
ALONG THE COLD FRONT TO THE SOUTH OF PA MOVES EAST
OF THE AREA.
09Z TAFS ADJUSTED FOR THE BANDS OF HEAVY SNOW.
EARLIER DISCUSSION BELOW.
FIRST OF THE SNOW WITH THE APPROACHING STORM NOW INVADING
SOUTHWEST PENNSYLVANIA. SNOW TO INCREASE RAPIDLY...AND BECOME
HEAVY OVERNIGHT AND EARLY MONDAY ACROSS THE SOUTHERN AIRFIELDS.
LATER MODEL RUNS CONTINUE TO INCREASE QPF AND RESULTANT SNOW.
EXPECTING A WINDOW OF MODERATE TO PERHAPS HEAVY SNOW IN SOUTHERN
AIRFIELDS TOMORROW FROM ABOUT 12Z TO 16Z. HAVE ADJUSTED TAFS TO
LOWER CIGS AND VSBYS.
PRECIPITATION MOVES OUT QUICKLY MONDAY AFTERNOON AND EVENING...
WITH A RETURN TO VFR CONDITIONS AT ALL LOCATIONS BEFORE 00Z
TUESDAY.
BRIEF PERIOD OF VFR CONDITIONS TUESDAY...BEFORE NEXT SYSTEM MOVES
IN TUESDAY NIGHT AND WEDNESDAY.
OUTLOOK...
TUE...MAINLY VFR.
TUE NIGHT-WED...WIDESPREAD IFR LIKELY IN MIXED PCPN.
THU...MVFR W AND N WITH SCT SNOW SHOWERS...MVFR TO VFR CENTRAL AND
SOUTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ024>028-050-052-058.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ033>036-056-057-059-063>066.
&&
$$
SYNOPSIS...ROSS
NEAR TERM...ROSS
SHORT TERM...ROSS
LONG TERM...ROSS
AVIATION...JUNG/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
431 AM EST MON FEB 3 2014
.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING SNOW TO THE SOUTHERN
AND EASTERN HALF OF THE STATE THIS MORNING. THEY HEAVIEST SNOWS
WILL FALL DURING THE MORNING COMMUTE LASTING THROUGH THE MORNING
HOURS. THOSE DRIVING IN THE CAPITOL DISTRICT...YORK AND LANCASTER
WILL NEED TO PREPARE FOR HAZARDOUS WINTER WEATHER DRIVING
CONDITIONS THIS MORNING. LOOK FOR IMPROVING CONDITIONS THIS
AFTERNOON AS HIGH PRESSURE BRIEFLY BUILDS ACROSS THE REGION. A
STRONGER AND MORE DYNAMIC WINTER STORM SYSTEM WILL IMPACT THE AREA
FROM TUESDAY NIGHT INTO WEDNESDAY...WITH THE POTENTIAL FOR
SIGNIFICANT SNOW AND ICE. DRY WEATHER AND BELOW NORMAL
TEMPERATURES SHOULD FINISH OUT THE SECOND HALF OF THE WEEK.
ANOTHER WINTER STORM SYSTEM MAY AFFECT THE AREA SOMETIME OVER THE
WEEKEND OR INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ANOTHER CHALLENGING FORECAST THIS WINTER. MAIN IMPACT FROM
DISTURBANCE MOVING INTO SOUTHERN ZONES EARLY THIS MORNING. ANY
RAIN WILL QUICKLY TURN OVER TO SNOW BEFORE SUNRISE. LATEST SHORT
TERM GUIDANCE INCLUDING LAST FEW HRRR RUNS SHOW A SHORT PERIOD OF
VERY HEAVY SNOWS ACROSS SE QUARTER OF CWA AND EXPANDED THE WSW
INTO THE HARRISBURG METRO AREA. MORNING COMMUTE WILL BE QUITE
TREACHEROUS ACROSS THIS AREA AS HEAVIEST SNOWS LOOK TO FALL DURING
THIS PERIOD. TOUGHEST PART OF FORECAST WILL BE FORECASTING SNOW
FOR THE NORTHERN EDGE OF THIS SYSTEM. RADAR TRENDS SHOW SHOWN A
SHARP CUTOFF IN INTENSITIES NORTH OF A CAMBRIA THROUGH CENTRE
COUNTY LINE. SNOW WILL REMAIN LIGHT NORTH OF THIS LINE
SIGNIFICANTLY LIMITING ACCUMULATIONS. WILL MONITOR CLOSELY IN CASE
THIS LINE SHIFTS NORTH...BUT SO FAR IT HAS NOT. WAVE WILL QUICKLY MOVE
EAST OF CWA BY THE EARLY AFTERNOON. SNOW WILL QUICKLY TAPER OFF
THOUGH TEMPERATURES WILL MOVE LITTLE THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
HIGH PRESSURE WILL BRING A QUIET NIGHT TO THE AREA WITH COLDER
LOWS GIVEN THE COLDER AIR MASS AND DECENT CONDITIONS FOR RADIATIONAL
COOLING.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
VERY ACTIVE AND CHALLENGING PERIOD OF WEATHER FOR THE EXTENDED
PERIOD. AFTER A QUIET WEATHER DAY ON TUESDAY HIGH PRESSURE QUICKLY
RETREATS NE AND THE NEXT WINTER STORM APPROACHES THE REGION
TUESDAY NIGHT AND WEDNESDAY. LATEST ENSEMBLE GUIDANCE SHOWS A
COLD STORM WITH A WIDE VARIETY OF PRECIPITATION SCENARIOS
POSSIBLE...DEPENDING ON THE TRACK OF THE SURFACE LOW. WIDE RANGE
OF MODEL GUIDANCE AND THE TRACK IS STILL UNCERTAIN. GEFS GUIDANCE
HAS THE BEST CHANCES OF LIQUID PRECIPITATION...INCLUDING FREEZING
RAIN OR PLAIN RAIN IN THE SOUTHEAST ZONES. IN THE CENTRAL ZONES INCLUDING
THE STATE COLLEGE AREA...PRECIP TYPES VERY CHALLENGING WITH
SIGNIFICANT SNOW FALL AND PERHAPS A PERIOD OF SLEET OR FREEZING
RAIN MIXED IN TO ADD TO THE COMPLEXITY OF THE FORECAST. AS YOU
HEAD TO THE NORTHERN ZONES THE CHANCES OF THE PRECIPITATION
REMAINING ENTIRELY AS SNOW INCREASE. FOR NOW HAVE NOT ISSUED ANY
HIGHLIGHTS FOR THIS STORM GIVEN THE LARGE AMOUNT OF UNCERTAINTY
THAT SILL EXISTS. AFTER THE STORM EXITS THE CWA ON WEDNESDAY
NIGHT THERE WILL BE A COUPLE DAY BREAK...THOUGH TEMPERATURES WILL
BE QUITE COLD TO END THE WORK WEEK...LIKELY BELOW FREEZING ACROSS
THE ENTIRE CWA. ANOTHER STORM SYSTEM IS FORECAST TO ARRIVE
SOMETIME NEXT WEEKEND...THOUGH TIMING IS STILL IN QUESTION. LATEST
GUIDANCE APPEARS TO PUSH IT BACK INTO THE SUNDAY OR MONDAY TIME
FRAME. THERMAL PROFILES AGAIN COLD WITH THE SYSTEM AND EXPECT
ANOTHER CHALLENGING FORECAST NARROWING DOWN THE EXPECTED IMPACTS.
STILL PLENTY OF TIME TO SEE HOW THAT EVOLVES.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
AN AREA OF PRECIPITATION NOW ALMOST TO INTERSTATE 80.
STILL ON THE MILD SIDE ACROSS THE SE...WILL TAKE SEVERAL
MORE HOURS FOR RAIN TO GO OVER TO SNOW.
MAIN CONCERN WILL BE FOR HEAVY WET SNOW ACROSS THE FAR
SOUTH LATE.
ACTIVITY WILL BE MAINLY EAST OF THE AREA BY EARLY TO MID
AFT...IF NOT SOONER.
EARLIER DISCUSSION BELOW.
FIRST OF THE SNOW WITH THE APPROACHING STORM NOW INVADING
SOUTHWEST PENNSYLVANIA. SNOW TO INCREASE RAPIDLY...AND BECOME
HEAVY OVERNIGHT AND EARLY MONDAY ACROSS THE SOUTHERN AIRFIELDS.
LATER MODEL RUNS CONTINUE TO INCREASE QPF AND RESULTANT SNOW.
EXPECTING A WINDOW OF MODERATE TO PERHAPS HEAVY SNOW IN SOUTHERN
AIRFIELDS TOMORROW FROM ABOUT 12Z TO 16Z. HAVE ADJUSTED TAFS TO
LOWER CIGS AND VSBYS.
PRECIPITATION MOVES OUT QUICKLY MONDAY AFTERNOON AND EVENING...
WITH A RETURN TO VFR CONDITIONS AT ALL LOCATIONS BEFORE 00Z
TUESDAY.
BRIEF PERIOD OF VFR CONDITIONS TUESDAY...BEFORE NEXT SYSTEM MOVES
IN TUESDAY NIGHT AND WEDNESDAY.
OUTLOOK...
TUE...MAINLY VFR.
TUE NIGHT-WED...WIDESPREAD IFR LIKELY IN MIXED PCPN.
THU...MVFR W AND N WITH SCT SNOW SHOWERS...MVFR TO VFR CENTRAL AND
SOUTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ024>028-050-052-058.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ033>036-056-057-059-063>066.
&&
$$
SYNOPSIS...ROSS
NEAR TERM...ROSS
SHORT TERM...ROSS
LONG TERM...ROSS
AVIATION...JUNG/MARTIN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1254 AM EST MON FEB 3 2014
.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL MOVE UP FROM THE SOUTHEAST ALONG A
NEARLY STATIONAL FRONTAL BOUNDARY ALONG THE BLUE RIDGE OVERNIGHT
AND THEN OFF THE VIRGINIA COAST BY LATE MONDAY. HIGH PRESSURE
WILL THEN MOVE ACROSS THE OHIO VALLEY INTO THE MID ATLANTIC ON
TUESDAY...WITH ANOTHER STORM SYSTEM MOVING OVER THE REGION TUESDAY
NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 945 PM EST SUNDAY...
THE AFTERNOON MODELS...INCLUDING MANY HIGH RESOLUTION MODELS...AND
THE TRENDS IN THE BROAD SHIELD OF PRECIPITATION UPSTREAM TO THE
SOUTHWEST...ARE ALL SHOWING INDICATIONS THAT PRECIPITATION
OVERNIGHT INTO EARLY MONDAY MORNING WILL LIKELY BE HEAVIER...WITH
MANY LOCATIONS WELL OVER AN INCH ACROSS WESTERN AND CENTRAL
PORTIONS OF THE FCST AREA...WITH OVER AN INCH AND A HALF OR EVEN
CLOSE TO TWO INCHES LOCALLY. ALL OF THIS WILL FALL MAINLY IN A 6-8
HOUR PERIOD FROM ABOUT 2 AM TO THE MID MORNING HOURS MONDAY. THIS
IS GENERALLY ABOVE THE 6 HR FLASH FLOOD GUIDANCE...AND WITH THE
GROUND FROZEN JUST ABOVE THE SURFACE AND EVEN A LITTLE SNOW PACK
LEFT IN THE HIGHEST ELEVATIONS...THE RUNOFF WIL OCCUR QUICKLY.
RAINFALL RATES ARE NOT LIKELY TO BE ESPECIALLY HIGH...SO THINK
FLASH FLOODING IS A RELATIVELY LOW THREAT...BUT AM CONCERNED ABOUT
MINOR FLOODING OF STREAMS AND CREEKS...AND POTENTIALLY SOME
LARGER RIVERS SUCH AS THE GREENBRIER AND BLUESTONE. ICE BREAKING
UP ON THESE RIVERS AND STREAMS IS ANOTHER CONCERN WITH THE RECENT
MILD WEATHER AND NOW RAINFALL ON TOP. THEREFORE..DECIDED TO GO
WITH A FLOOD WATCH FOR WESTERN COUNTIES FROM TAZEWELL UP THROUGH
GREENBRIER AND BATH...WITH GREENBRIER REALLY BEING THE HIGHEST
THREAT AREA AS THE HEAVIEST RAIN BULLSEYE COMBINING WITH THE
LOCATION WHERE THE MOST SNOW REMAINS ON THE GROUND. RAN THIS
THROUGH 6PM MONDAY WELL AFTER THE RAIN WILL HAVE TAPERING
OFF...BUT IF ANY FLOODING DOES OCCUR IT MAY LINGER BEYOND THIS.
TEMPERATURES THIS EVENING HAVE BEEN RUNNING MILDER THAN EXPECTED
ANAD GUIDANCE...AND WITH TRENDS IN MODELS AND OBSERVATIONS
SUGGESTING A SLOWER ARRIVAL OF COLDER AIR...BUMPED UP MIN TEMPS A
FEW DEG OVERNIGHT AND RESULTING IN A LITTLE LESS AREA WITH
ACCUMULATING SNOWFALL VERY LATE TONIGHT AND INTO TOMORROW MORNING.
HOWEVER...THOSE HIGHEST ELEVATIONS THAT DO CHANGE OVER TO SNOW MAY
AHVE HIGHER SNOWFALL RATES...ALBEIT A FAIRLY WET HEAVY SNOW...SO
ENDED UP INCREASING THE AMOUNTS BUT OVER SMALL GEOGRAPHICAL AREA.
MAY SEE A QUICK BURST OF 2-3 INCHES IN WRN GREENBRIER OR THE
HIGHEST RIDGES OF BATH EARLY IN THE MORNING...LINGERING THROUGH
MID TO LATE MORNING. BUT MOST AREAS OUTSIDE THIS LOOK TO SEE ONLY
COLD RAIN...BUT PERHAPS MORE OF THAT.
PREV DISCUSSION AS OF 505 PM EST SUNDAY...
MINOR UPDATE TO LOWER POPS THIS EVENING IN WEST AS PRECIP TAKING
ITS TIME TO ADVANCE INTO RELATIVDELY DRY AIRMASS. RADAR MOSAIC AND
LATEST HRRR AND RAP MODELS SUGGEST ANY ACCUMULATING PRECIP MAY
HOLD OFF UNTIL LATE EVENING. TWEAKED SKY COVER AS WELL TO ADJUST
FOR PARTIAL CLEARING IN EAST WHICH MAY NOT THICKEN BACK UP UNTIL
LATE EVENING AS WELL. VERY MINOR TWEAKS TO TEMPS PER LATEST
CONDITIONS...SLOWING DOWN EVENING COOLING A BIT. OTHERWISE NO
OTHER CHANGES AT THIS POINT.
PREV DISCUSSION AS OF 235 PM EST SUNDAY...
MODELS SHOWING A MAINLY RAIN EVENT FOR OUR FORECAST AREA. THE FRONT
HAS BEEN SLOW TO MOVE THIS AFTERNOON THANKS TO THE HIGH OVER THE
SOUTHEAST...AND LACK OF KICKER UPSTREAM. SHORTWAVE ENERGY OVER TX/OK
THIS AFTERNOON WILL BE PUSHING THE FRONT EAST-SOUTHEAST THROUGH
TONIGHT...WHERE IT STALLS FROM THE SOUTHERN APPALACHIANS INTO THE VA
PIEDMONT. STRONG DYNAMICS ALOFT SUPPORT THE IDEA OF A 6-8 HOUR
WINDOW OF MODERATE AND POSSIBLY HEAVY RAIN...STARTING AFTER MIDNIGHT
IN THE WV MTNS AND SPREADING EAST INTO THE PIEDMONT BY DAWN. GOING
TO BE A TRICKY SCENARIO ACROSS OUR NRN/NWRN FRINGE OF THE CWA FROM
GREENBRIER TO AMHERST AS MODEL FLIRTING WITH THE 8H ZERO ISOTHERM
SHIFTING SE ONCE THE SURFACE LOW PASSES EAST AFTER 12Z. QUESTION IS
HOW MUCH QPF IS LEFT. AT THIS TIME WPC FAVORS LOW SNOW AMOUNTS. NOT
SEEING ANY ICE ISSUES PER MODEL SOUNDINGS...BUT COULD SEE SLEET INTO
THE MOUNTAIN EMPIRE OF TAZEWELL. HIGHER ELEVATIONS OF GREENBRIER AND
BATH INTO THE BLUE RIDGE COULD PICK UP A QUICK 1-2 INCHES OF SNOW
WITH ISOLATED 3 INCH AMOUNTS NOT OF THE QUESTION...BUT SWEET SPOT
FOR SNOW LOVERS WILL BE FURTHER NORTH OF US. JUST A COLD RAIN FOR 95
PERCENT OF OUR AREA.
TEMPS THROUGH THE PERIOD WILL STAY MOSTLY ABOVE FREEZING AS CLOUDS
START TO ENVELOP THE REGION THIS EVENING...HOLDING TEMPS UP. WE WILL
SEE DEWPOINTS INCREASE AS WELL WITH THE LIGHT RAIN SHOWERS
MOISTENING THE LOW LVLS...AND SCOURING OUT ANY RESIDUAL DRY AIR.
OVERNIGHT LOWS WILL RANGE FROM AROUND FREEZING IN THE HIGHER RIDGES
OF AMHERST TO GREENBRIER WITH MID TO UPPER 30S I-81 CORRIDOR AND
EAST TO LYH WHILE SOUTHSIDE VA INTO THE NC COUNTIES DROP TO LOWER
40S.
CLOUDS/PRECIP TOMORROW LIMIT HEATING. SUNSHINE APPEARS TO BE TOO LATE
IN HELPING IN THE WEST BUT GIVEN A LACK OF DECENT COLD ADVECTION
BEHIND THE DEPARTING LOW...WILL SEE TEMPS ON THE COOLER SIDE OF
SEASONAL NORMS BUT NOT ARCTIC COLD....RANGING FROM THE MID TO UPPER
30S OVER THE WV MOUNTAINS INTO THE ALLEGHANYS...TO LOWER TO MID 40S
FROM LYNCHBURG TO ROANOKE...ACROSS THE NEW RIVER VALLEY INTO THE NC
MOUNTAINS...WHILE SOUTHSIDE VA AND NW NC FOOTHILLS AND PIEDMONT
REACH THE UPPER 40S TO LOWER 50S.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
AS OF 257 PM EST SUNDAY...
WEDGE SETTLES ACROSS THE REGION AND STRENGTHENS OVERNIGHT INTO
TUESDAY. THE NAM/MET...WHICH USUALLY DOES BEST WITH THERMAL
STRUCTURE IN WEDGES...COOLED OFF A BIT FROM PREVIOUS RUNS. JUDGING
BY THE STRENGTH AND THE DIRECTION OF THE AGEOSTROPHIC COMPONENT...AND
THE SURFACE UPSLOPE COMPONENT OF THE WINDS...THERE`S A FAIR CHANCE
THAT SUBFREEZING AIR TEMPS ARE IN PLACE ALONG THE SPINE OF THE BLUE
RIDGE FROM SW VA INTO NW NC LATE MONDAY NIGHT AND INTO TUESDAY. THIS
WOULD MEAN THAT FREEZING DRIZZLE/RAIN IS A POSSIBILITY FROM EASTERN
ASHE/WATAUGA CREEPING UP TO FLOYD COUNTY IN THE AFTERNOON. DURING
THESE EVENTS...THE WEDGE IS TYPICALLY STRONGEST IN THE
AFTERNOON...SUCH THAT TEMPS RIGHT ALONG THE BLUE RIDGE TYPICALLY
FALL DURING THE LATE MORNING AND AFTERNOON HOURS. A WET AND WARM
GROUND WOULD PROBABLY PRECLUDE ANY LIGHT ICING ON THE ROADS...MAINLY
IN THE TREES AND ELEVATED SURFACES. ONLY HAVE A FEW HUNDREDTHS OF AN
INCH OF ICE ACCUMULATION...NOTHING TO BE TOO CONCERNED ABOUT AS OF
YET...BUT SOMETHING TO WATCH...ESPECIALLY IF THE 2M NAM TEMPS
CONTINUE TO TREND COOLER AND STAY BELOW FREEZING ALL DAY AND INTO A
SIGNIFICANT PART OF TUESDAY NIGHT. BY TUESDAY EVENING...TEMPS MAY
FALL TO FREEZING IN EASTERN AND NORTHEASTERN GREENBRIER COUNTY...AND
PERHAPS ALSO THE SOUTHERN SHENANDOAH...WITH A TOUCH OF FREEZING RAIN
THERE. ELSEWHERE...IN AND OUT SHOWERS WILL BECOME MORE NUMEROUS FROM
SW TO NE BY LATE DAY TUESDAY ACROSS THE REGION. THE MAIN BODY OF
PRECIP SHOULD ARRIVE JUST AHEAD OF THE COLD FRONT WHICH SHOULD
ARRIVE WEDNESDAY MORNING TO AFTERNOON. SOME UPSLOPE FLOW SHOULD TURN
RAIN TO SNOW WITH H85 TEMPS AROUND -9C LATE DAY IN WESTERN
GREENBRIER. MUCH OF THE RAIN MAY BE OVER WITH BY WEDNESDAY AFTERNOON
ELSEWHERE. AS THE WEDGE BREAKS WEDNESDAY MORNING...CUSTOMARY GUSTS
FROM THE SSE NEAR ADVISORY CRITERIA MAY BE OBSERVED IN THE
BLF/JFX/MKJ CORRIDOR. MORE WINTERLIKE AIR ARRIVES BEHIND THE FRONT
INTO WEDNESDAY MORNING.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 345 PM EST SUNDAY...
WILL START THURSDAY MORNING OFF WITH A BREAK IN THE WEATHER AS HIGH
PRESSURE BUILDS EAST ALONG THE SOUTHERN GREAT LAKES...AND THEN
PUSHES SOUTHWARD ALONG THE EASTERN FACE OF THE APPALACHIANS THURSDAY
EVENING INTO FRIDAY MORNING. THE CLEARING SKIES AND DOWNSLOPE WIND
FLOW WILL ALLOW THE SOUTHSIDE TO WARM INTO THE MID 40S FOR AFTERNOON
HIGHS...HOWEVER INCREASED CLOUD COVER AND COLDER AIR BUILDING IN
WITH THE HIGH WILL KEEP TEMPERATURES IN THE MOUNTAINS STUCK IN THE
30S. INCREASING CLOUD COVER DURING THE EVENING WILL HELP LIMIT
COOLING OVERNIGHT...AND WILL BE LOOKING FOR THURSDAY NIGHT LOWS TO
HOLD IN THE MID AND UPPER 20S MOST LOCATIONS.
BY FRIDAY MORNING...HIGH PRESSURE WILL BE FIRMLY SITUATED ALONG THE
EASTERN FACE OF THE APPALACHIANS...RESULTING IN A COOL EAST TO
SOUTHEASTERLY WIND FLOW THAT WILL NOT ALLOW FOR ALL THAT MUCH
WARMING. LONG RANGE MODELS HAVE DIFFERING OPINIONS AS TO HOW STRONG
AN UPPER LEVEL DISTURBANCE RIDING ALONG THE FRONTAL BOUNDARY TO OUR
SOUTH WILL BE...AND HOW MUCH RESULTING PRECIPITATION WILL AFFECT OUR
AREA. THE ECMWF FORECAST MODEL APPEARS VERY BULLISH WITH THE
PRECIPITATION...AND OVERDONE CONSIDERING THAT THE UPPER LEVEL
DISTURBANCE DOES NOT APPEAR VERY STRONG. THEREFORE...STICKING A
LITTLE CLOSER TO THE MORE CONSERVATIVE GFS MODEL AS FAR AS
PRECIPITATION CHANCES. BELIEVE WE WILL START THE DAY WITH LIGHT SNOW
THAT WILL GRADUALLY CHANGE TO RAIN AS WARMER AIR WORKS IN FROM THE
SOUTH.
FOR FRIDAY NIGHT AND SATURDAY...UNCERTAINTY IN THE FORECAST
INCREASES AS BOTH TIMING AND THE TRACK OF A DEVELOPING STORM SYSTEM
BEGINS TO DIFFER AMONG THE FORECAST MODELS. THE UPPER DISTURBANCE
WILL PASS TO THE EAST FRIDAY EVENING...RESULTING IN A BRIEF BREAK IN
THE PRECIPITATION FOR OUR AREA...BEFORE ANOTHER MUCH STRONGER TROUGH
BEGINS TO PUSH OUT OF THE SOUTHERN ROCKIES. SOUTHERLY FLOW AHEAD OF
THIS SYSTEM WILL PUSH WARMER GULF AIR INTO OUR AREA JUST OFF THE
SURFACE...WHILE THE HIGH PRESSURE WEDGE WILL KEEP SURFACE
TEMPERATURES AROUND THE FREEZING MARK FOR MUCH OF OUR AREA. AT THIS
POINT...LOOKING AT A COMPLEX FORECAST FOR FRIDAY NIGHT WITH RAIN
ACROSS THE PIEDMONT OF NORTH CAROLINA WHERE TEMPERATURES WILL REMAIN
ABOVE FREEZING...FREEZING RAIN NORTHWARD TO AROUND THE INTERSTATE 64
CORRIDOR...AND THEN SNOW FURTHER NORTH. TEMPERATURES WILL WARM ABOVE
FREEZING FOR MOST OF OUR AREA SATURDAY AFTERNOON...CAUSING NEARLY
ALL PRECIPITATION TO CHANGE OVER TO RAIN.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 1255 AM EST MONDAY...
RAIN AND IFR CONDITIONS HAVE REACHED BOTH BLF AND LWB EARLY THIS
MORNING...AND SHOULD BE AT BCB AND ROA BY 08Z...THEN LYH BY 09 OR
10Z...BUT MAY TAKE UNTIL AFTER 12Z BEFORE REACHING DAN...AT LEAST
THE IFR CIGS MAY TAKE THAT LONG. HEAVIER PRECIP WILL LAST AT
WESTERN SITES UNTIL 13 OR 14Z...AND THEN MAY MIX IN WITH SNOW OR
SLEET AT BLF AND LWB BY ABOUT 15 OR 16Z BEFORE ENDING EARLY
AFTERNOON...POSSIBLY SOONER. THERE IS A SMALL POTENTIAL FOR A
BRIEF PERIOD OF HEAVY WET SNOW AT LWB AROUND 13 TO 15Z...BUT MOST
LIKELY WILL REMAIN ALL RAIN. AS RAIN BEGINS...INSITU DAMMING WILL
ALSO INCREASE WITH SFC WINDS TURNING OUT OF THE NORTHEAST AND MAY
GET OVER 10 KTS AT LYH AND DAN.
MODERATE RAIN WITH IFR CONDITIONS WILL LIKELY EXIT FAIRLY QUICKLY
BY MIDDAY MONDAY. IFR CIGS MAY LAST AT WESTERN SITES IN WEAK
NORTHERLY TO NORTHWEST FLOW THROUGH MUCH OF AFTERNOON BEFORE
IMPROVING BACK TO MVFR BY LATE AFTERNOON OR EVENING. LOW CONFIDENT
FCST IN TERMS OF POSSIBLE IMPROVEMENT TO VFR OVERNIGHT AS WEAK
WEDGE AND EASTERLY FLOW DEVELOPS AGAIN DURING THE EVENING. KLWB
MOST LIKELY TO FINALLY GET A VFR CIG BY EVENING...AND MAYBE BLF
TOO...BUT CONCERNED THAT ALL OTHER AIRPORTS MAINTAIN LOW CIGS
OVERNIGHT MONDAY NIGHT WITH NORTHEAST SFC FLOW. MODELS MAY BE
OVERDOING THIS SO AS WE GET CLOSER MAY BE ABLE TO LIFT THESE TO
VFR AT SOME POINT...AND ESPECIALLY BLF AND LWB SHOULD GO VFR FOR
AWHILE BY TUESDAY MORNING.
NEXT SYSTEM ARRIVES FROM THE SOUTHWEST LATE TUES OR TUESDAY
NIGHT...LASTING INTO WEDNESDAY WITH GOOD THREAT OF PRECIP AND
RETURN TO WIDESPREAD LOWER CIGS/VSBYS...WITH MUCH OF THE AREA
UNDER CAOLD AIR DAMMING AGAIN...BUT THIS WILL BREAK DURING THE DAY
WEDNESDAY WITH SOME RAIN SHOWERS IN MVFR OR VFR CONDITIONS...AND
THEN WITH SNOW SHOWERS AT WED TAF SITES LATER IN THE DAY WED.
ANOTHER BREAK BY WED NIGHT INTO EARLY FRIDAY WITH HIGH PRESSURE
ARRIVING FROM THE NORTHWEST BEFORE ANOTHER SYSTEM MOVES UP FROM
THE GULF COAST STATES FRIDAY AFTERNOON INTO THE WEEKEND. THIS IS A
VERY COMPLEX PATTERN WITH A VERY LOW CONFIDENCE AT THIS POINT...AS
TIMING...PRECIP AMOUNTS...AND PRECIP TYPE ARE ALL IN QUESTION.
&&
.HYDROLOGY...
AS OF 250 PM SUNDAY...
THREAT OF FLOODING ON THE RIVERS AND STREAMS STILL LOOKING
LOW...ALTHOUGH THE FROZEN...SOME THAWING GROUND...PLUS REPORTS OF
RIVER/STREAM ICE MAY LEAD TO ISOLATE PROBLEMS. FORECAST RAINFALL
AMOUNTS FROM THIS FIRST SYSTEM TONIGHT-MONDAY ARE INDICATING
GENERALLY 1 TO 1.5 INCHES...WITH HIGHER TOTALS ACROSS THE UPPER
ROANOKE BASIN AND PORTIONS AND JAMES. FORECASTS FROM SURROUNDING
RIVER FORECAST CENTERS SHOWING RIVERS COMING UP TO JUST UNDER ACTION
STAGES. ENSEMBLE FORECASTS ALSO INDICATING LOW RISK OF FLOODING.
THE NEXT SYSTEM ARRIVING LATER TUESDAY INTO TUESDAY NIGHT LOOKS LESS
ON PRECIP AMOUNTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS AFTERNOON FOR VAZ007-019-020.
NC...NONE.
WV...FLOOD WATCH THROUGH THIS AFTERNOON FOR WVZ042>045.
&&
$$
SYNOPSIS...SK/WP
NEAR TERM...SK/WP
SHORT TERM...KM
LONG TERM...NF
AVIATION...SK/WP
HYDROLOGY...WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1133 PM CST SUN FEB 2 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SYNOPSIS...
ISSUED AT 224 PM CST SUN FEB 2 2014
FAIRLY QUIET MID-WINTER WX WITH CONTINUED BELOW NORMAL
TEMPERATURES AND JUST SOME LIGHT SNOW OR FLURRIES AT TIMES.
THE FLOW OVER THE NERN PAC WL BECOME INCREASINGLY BLOCKY AS STG
POSITIVE HEIGHT ANOMALY GRADUALLY RETROGRADES TOWARD THE
DATELINE. THE FLOW DOWNSTREAM ACRS NOAM IS SPLIT...WITH SRN AND
NRN STREAMS UNDERCUTTING AND FLOWING ARND THE NERN PAC BLOCK
/RESP/ BEFORE MERGING BACK TOGETHER OVER THE ERN CONUS. THE FCST
AREA HAS BECOME POSITIONED WITHIN THE CONFLUENT ZONE BETWEEN THE
MERGING STREAMS...AND THAT SHOULD CONT FOR THE FCST PERIOD. THAT
WL DIRECT THE MAIN WX PRODUCING SYSTEMS ARND THE AREA TO THE N AND
S...LEADING TO FAIRLY TRANQUIL MIX-WINTER WX. EXPECT SOME LIGHT
SNOW/FLURRIES AT TIMES AS THE FCST AREA GETS GRAZED BY THE TAIL OF
NRN STREAM SHRTWVS OR THE NRN FRINGE OF SRN STREAM CYCLONES...BUT
THESE ARE NOT EXPECTED TO BE SIG PCPN EVENTS. TEMPS WL REMAIN WELL
BLO NORMAL...BUT NOT AS BRUTALLY COLD AS THEY WERE AT TIMES DURING
JANUARY.
&&
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 224 PM CST SUN FEB 2 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE CENTERED FROM THE CENTRAL MISSISSIPPI VALLEY TO THE CENTRAL
GREAT PLAINS EARLY THIS AFTERNOON. AN AREA OF LOW STRATUS IS MOVING
JUST NORTH OF DUE EAST OVER NORTHERN MINNESOTA AND THE SOUTHERN EDGE
MAY JUST BRUSH NORTH-CENTRAL WISCONSIN LATER THIS AFTERNOON. CIRRUS
FROM A SOUTHERN STREAM SYSTEM IS ALSO MOVING ACROSS SOUTHERN
WISCONSIN. MEANWHILE...SUNNY SKIES ARE PREVAILING OVER THE FORECAST
AREA...AND UPSTREAM AS WELL OVER SOUTH DAKOTA...NEBRASKA AND NORTHERN
IOWA/SOUTHERN MINNESOTA. AS A RESULT...FORECAST CONCERNS ARE
MINIMAL AND INCLUDE MAINLY TEMPERATURES.
TONIGHT...ARCTIC HIGH PRESSURE WILL BE SHIFTING FROM THE CENTRAL
GREAT PLAINS TO THE MID-MISSISSIPPI VALLEY AND SOUTHERN GREAT
LAKES. RATHER THIN LOW STRATUS DECK WILL GRAZE FAR NORTH-CENTRAL
WISCONSIN THIS EVENING. ELSEWHERE...SKIES ARE ANTICIPATED TO REMAIN
MOSTLY CLEAR. 1000-850MB WINDS ARE PROJECTED TO RANGE FROM 15 TO 20
KTS...WHICH IS TYPICALLY MARGINAL FOR DECOUPLING. BUT A RELAXING
PRESSURE GRADIENT WITH THE INCOMING SURFACE HIGH WILL SUPPORT WINDS
DROPPING OFF. THINK CENTRAL WISCONSIN WILL HAVE A HIGHER POTENTIAL
FOR THIS TO OCCUR...BUT DROPPED TEMPS EVERYWHERE SINCE IT WONT TAKE
VERY LONG FOR TEMPS TO TANK. LOOKING AT UPSTREAM OBS...TEMPS FELL TO
20 BELOW WHERE WINDS WENT CALM...BUT GENERALLY STAYED BETWEEN 5 AND
10 BELOW WHERE WINDS REMAINED 3-5 KTS. WILL KEEP TEMPS IN THIS
RANGE...WITH A FEW COLDER TEMPS IN THE COLD SPOTS.
MONDAY...HIGH PRESSURE WILL CONTINUE TO LIFT NORTHEAST TOWARDS THE
EASTERN GREAT LAKES. SHORTWAVE ACTIVITY MOVING EAST OVER ONTARIO
AND SOUTH-CENTRAL CANADA WILL PUSH A WEAK COLD FRONT ACROSS WESTERN
LAKE SUPERIOR INTO CENTRAL MINNESOTA. WILL SEE WARM ADVECTION AHEAD
OF THE FRONT WITH 850MB TEMPS WARMING TO THE LOW TEENS BELOW ZERO.
THIS WILL TRANSLATE TO A WARMER DAY DESPITE A VERY COLD START.
WENT WITH HIGHS IN THE MID TEENS TO NEAR 20. SHOULD SEE MOSTLY
SUNNY CONDITIONS FOR THE MORNING...THEN INCREASING CLOUDS MID TO
LATE AFTERNOON.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 224 PM CST SUN FEB 2 2014
LITTLE CHG TO THE EXPECTED EVOLUTION OF WX EVENTS SINCE YDA. FCST
AREA WL BE ON THE NRN EDGE OF CYCLONE HEADED THROUGH THE OHIO
VALLEY TOWARD THE MID-ATL STATES TUE NGT/WED. THE EXACT POSN OF
THE NRN EDGE OF THE PCPN SHIELD IS TOUGH TO GAUGE...SO KEPT CHC
POPS ACRS ABOUT THE SRN 1/2 OF THE FCST AREA WED. UNLESS THERE IS
SUDDENLY A BIG SHIFT IN THE TRACK OF THE SYSTEM /WHICH SEEMS
UNLIKELY AT THIS POINT/ THINK THE VERY MOST WE/D BE ABLE TO DO IS
SQUEEZE OUT AN INCH OR TWO OF SNOW OVER THE FAR SE PART OF THE
FCST AREA. KEPT POPS IN CHC CATEGORY FOR NOW.
ANOTHER SYSTEM IS LIKELY TO BE HEADED ENEWD FM THE PLAINS NEXT
WEEKEND. MODELS WERE FURTHER N WITH THAT SYSTEM...BUT THEN AGAIN
EARLY MODEL RUNS WERE TOO FAR N WITH YDAS SYSTEM AND WL LIKELY
END UP BEING TOO FAR N WITH THE SYSTEM FOR TUE NGT/WED INTIALLY AS
WELL.
TEMPS WL PROBABLY AVERAGE 8-16 F DEG BLO NORMAL. THATS
SIGNIFICANT...BUT NOTHING SPECIAL AFTER THE 2 BRUTALLY COLD SNAPS
BACK IN JANUARY. AS TYPICAL...OVERNIGHT LOWS WL DEPEND HEAVILY ON
CLDS AND WINDS. THE AIR MASS WL EASILY SUPPORT DOUBLE DIGIT BLO
ZERO MINS ON ANY NIGHTS WITH SEVERAL HRS OF CLR SKIES AND LGT
WINDS.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1124 PM CST SUN FEB 2 2014
ARCTIC HIGH PRESSURE WILL SHIFT EAST THROUGH THE STATE MUCH OF THIS TAF
PERIOD WITH MAINLY CLEAR SKIES EXPECTED. TROF MOVING THROUGH
SOUTHERN CANADA WILL BRING A WK COLD FRONT THROUGH STATE MON
EVENING. NO PCPN ECPECTED...THOUGH LOOK FOR SOME INCREASING MID
AND HIGH MOISTURE MON EVENING AHEAD OF SYSTEM PASSING TO THE
SOUTH OF STATE TUE TIMEFRAME.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......TE
AREA FORECAST DISCUSSION...CORRECTED
NWS EUREKA CA
429 AM PST MON FEB 3 2014
.SYNOPSIS...A WEAK DISTURBANCE ALOFT WILL CONTINUE TO MOVE SOUTH
ACROSS THE AREA THIS MORNING BRINGING THE POSSIBILITY OF LIGHT
SHOWERS. MORE LIGHT PRECIPITATION IS POSSIBLE AROUND MID-WEEK AS
ANOTHER WEAK DISTURBANCE ALOFT MOVES TOWARD THE COAST.
&&
.DISCUSSION...A WEAK SHORTWAVE IS PRESENTLY DIVING SSE OVER THE
AREA IN THE BROADER SCALE TROF WHICH EXTENDS FROM W CANADA TO S
CA. THIS FEATURE APPEARED TO LACK ANY SIGNIFICANT MOISTURE AS IT
HEADED INTO THE AREA EARLY THIS MORNING...BUT A LINE OF SHOWERS
DEVELOPED AS IT APPROACHED THE S REDWOOD COAST AND A FEW MORE
SHOWERS HAVE FORMED IN THE COASTAL WATERS NEAR AND N OF CAPE
MENDOCINO. THE LATEST RUC HAS A FAIR HANDLE ON THIS PRECIP...AND
HAVE USED IT TO POPULATE THE FIRST 6 HOURS OF THE POP AND CLOUD
GRIDS. THIS ACTIVITY IS FORECAST TO WANE AS WE PROCEED INTO THE
AFTERNOON HOURS WITH PARTLY CLOUDY SKIES IN MOST AREAS.
ANOTHER SHORTWAVE EMBEDDED WITHIN NW FLOW WILL APPROACH THE AREA
ON WED. MODELS ARE STRETCHING THIS ENERGY AND MOISTURE WILL BE
LIMITED. AS A RESULT...HAVE KEPT POPS MOSTLY IN THE LOW END CHANCE
CATEGORY OVER LAND WITH HIGHEST POPS AIMED MORE AT THE S 1/2 OF
THE AREA. THIS IS A LARGE AMOUNT OF UNCERTAINTY WITH RESPECT TO
EVOLUTION OF THIS FEATURE...BUT PRECIP AMOUNTS ARE EXPECTED TO BE
LIGHT.
THE MOST SIGNIFICANT WX PLAYER OF THE WEEK WILL WARM FRONTAL RAINS
WHICH TAP INTO A DECENT MOISTURE FEED FROM THE CENTRAL PACIFIC
THIS WEEKEND. SOME HEAVY RAINS WILL BE POSSIBLE...ESPECIALLY
COMPARED TO THE STORM TOTALS THAT HAVE BEEN RECEIVED SO FAR THIS
WINTER. HOWEVER...MODELS DO BUILD A SHALLOW RIDGE OVER THE W COAST
DURING THIS TIME PERIOD. IN FACT...THIS RIDGE WILL PLAY A LARGE
PART IN HOW MUCH MOUNTAIN SNOWS OCCUR THIS WEEKEND. INDICATIONS
ARE THAT SOME GOOD SNOWS WILL OCCUR...BUT SNOW LEVELS WILL BE ON
THE RISE AS WE GET INTO SUNDAY. HOWEVER...THE E MOUNTAINS WILL BE
THE LAST TO WARM...AND COLDER AIR MAY REMAIN TRAPPED IN SOME OF
THE HIGH VALLEYS. WILL LIKELY BEGIN TO HIGHLIGHT THIS SYSTEM IN
PRODUCTS EITHER TODAY OR TONIGHT. /SEC
&&
.AVIATION...VFR CONDITIONS AND LIGHT TO MODERATE WINDS TO CALM
CONDITIONS ARE OCCURRING AT KCEC...KACV AND KUKI. PATCHY FOG MAY
REDUCE VISIBILITIES TO MVFR CONDITIONS AT KUKI EARLY THIS MORNING.
VFR CONDITIONS AND LIGHT WINDS TO CALM CONDITIONS WILL OCCUR AT
KCEC, KACV AND KUKI THIS AFTERNOON AND TONIGHT.
&&
.MARINE...MODERATE NORTHERLY WINDS WILL PREVAIL ACROSS THE WATERS
THROUGH TUESDAY. THE WINDS WILL DIMINISH ON WEDNESDAY AS A LOW
PRESSURE TROUGH MOVES THROUGH THE AREA THEN INCREASE ON THURSDAY
BEHIND THE LOW PRESSURE TROUGH. SEAS WILL BUILD TODAY IN RESPONSE TO
HIGHER WINDS. SHORT PERIOD SEAS WILL OCCUR THIS WEEK. SMALL CRAFT
ADVISORIES WILL BE IN EFFECT ACROSS THE SOUTHERN OUTER WATERS TODAY
DUE TO INCREASING WINDS.
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY FROM NOON TO 9 PM TODAY PZZ475.
&&
$$
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AREA FORECAST DISCUSSION
NWS COLUMBIA SC
948 AM EST MON FEB 3 2014
.SYNOPSIS...
LOW PRESSURE WILL LIFT NORTHEAST OF THE FORECAST AREA TODAY. THE
TRAILING COLD FRONT WILL MOVE THROUGH THE AREA THIS AFTERNOON. THE
FRONT WILL STALL JUST SOUTH AND EAST OF THE AREA TONIGHT. ANOTHER
COLD FRONT APPROACHING FROM THE WEST WILL MOVE THROUGH THE REGION
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW PRESSURE WILL BE LIFTING NORTHEAST OF THE FORECAST AREA
TODAY. THE ASSOCIATED COLD FRONT WILL CROSS THE AREA THIS
AFTERNOON. CONVERGENCE ALONG AND AHEAD OF THE FRONT SUPPORTS
SHOWERS. 88D REGIONAL COMPOSITE SHOWS A BROKEN BAND OF LIGHT
SHOWERS STRETCHING FROM THE UPSTATE/NRN MIDLANDS SOUTHWEST TO
CENTRAL GA. THE SPC WRF AND HRRR WERE GOOD IN SHOWING THAT THE
SHOWERS WOULD BE MOVING INTO THE WESTERN PART OF THE CWA DURING THE
900 AM TO 1000 AM TIME FRAME. THE HIGH-RESOLUTION MODELS SHOW
SHOWER COVERAGE DECREASING THEREAFTER...THIS ALSO SEEMS TO BE THE
TREND LOOKING AT THE PAST HOUR OF RADAR DATA. SATELLITE TRENDS
WITH THE COLDER CLOUD TOPS SHIFTING WELL NORTH OF THE FORECAST
AREA SUPPORT THE MODEL FORECAST OF A LOSS OF UPPER-LEVEL LIFT. WE
FORECASTED LIKELY POPS IN THE WEST PART AND JUST CHANCE POPS IN
THE EAST PART TODAY.
SHEAR WILL BE HIGH WITH H85 WINDS NEAR 40 KNOTS. HOWEVER...THE
SEVERE THREAT APPEARS LOW BECAUSE OF A LACK OF SURFACE-BASED
INSTABILITY. THE NAM KEEPS SURFACE-BASED LI/S GREATER THAN 1 AND
THIS APPEARS REASONABLE BECAUSE OF CLOUDINESS AND MID-LEVEL
CAPPING. THE NAM AND GFS DISPLAY RISING H5 HEIGHTS TODAY.
THE TEMPERATURE GUIDANCE WAS CONSISTENT. BASED ON THE GFS LAMP
AND THE NAM TIME-HEIGHT DISPLAYS AND EXPECTED MIXING BELIEVE SOME
WIND GUSTS NEAR 20 KNOTS WILL OCCUR THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE FRONT WILL STALL JUST SOUTH AND EAST OF THE FORECAST AREA
TONIGHT. A WEDGE-RIDGE PATTERN WILL DOMINATE BEHIND THE FRONT
TONIGHT THROUGH TUESDAY NIGHT. ISENTROPIC LIFT WILL SUPPORT
CLOUDINESS AND A CHANCE OF RAIN. WE USED THE GUIDANCE CONSENSUS
FOR THE POP FORECAST. THE RAIN CHANCE SHOULD GRADUALLY INCREASE
WITH CONTINUED ISENTROPIC LIFT. THE TEMPERATURE GUIDANCE WAS
CONSISTENT BUT IS LIKELY TOO WARM TUESDAY BECAUSE OF THE WEDGE
PATTERN.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE MODELS DISPLAY ANOTHER COLD FRONT MOVING INTO THE FORECAST
AREA WEDNESDAY. WE LEANED TOWARD THE HIGHER ECMWF MOS AND
FORECASTED LIKELY POPS BECAUSE OF CONVERGENCE ASSOCIATED WITH THE
FRONT. THE NAM AND GFS MOS INDICATED LOWER POPS AND THIS MAY BE
CORRECT BECAUSE OF A LACK OF SIGNIFICANT UPPER-LEVEL LIFT.
CONFIDENCE IN THE POP FORECAST WEDNESDAY IS LOW. THE MODELS SHOW
JUST WEAK COLD ADVECTION BEHIND THE FRONT WEDNESDAY AFTERNOON.
EXPECT BREAKS IN THE CLOUDINESS SO AFTER A RELATIVELY WARM START...
THE NAM...GFS...AND ECMWF MOS TEMPERATURES APPEAR REASONABLE WITH
HIGHS NEAR 70.
THE MODELS SHOW BRIEF DRYING BEHIND THE FRONT THURSDAY...BUT A
RETURN TO ISENTROPIC LIFT AND DEEPER MOISTURE FRIDAY AND SATURDAY.
THE MODELS SHOW LOW PRESSURE NEAR THE AREA SUNDAY.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
LLWS HAS DEVELOPED EARLY THIS MORNING AHEAD OF AN APPROACHING COLD
FRONT. DUE TO MIXING AND CLOUDS...ANTICIPATE MAINLY MVFR CIGS THIS
MORNING. CIGS/VSBYS SHOULD IMPROVE SOMEWHAT AROUND 14Z TO 15Z WITH
SHOWERS MOVING INTO THE TAF SITES AHEAD OF AN APPROACHING COLD
FRONT. HAVE INDICATED SOUTHWEST WIND AROUND 10 KNOTS WITH GUSTS
NEAR 20 KNOTS AHEAD OF THE COLD FRONT WHICH IS SCHEDULED TO CROSS
THE TAF SITES IN THE 18Z-21Z TIME-FRAME. BY LATE IN THE TAF
PERIOD...WINDS SHIFT TO THE NORTHEAST AS WEDGE CONDITIONS DEVELOP
FROM NORTH TO SOUTH.
EXTENDED AVIATION OUTLOOK... MVFR OR LOWER CONDITIONS POSSIBLE
TUESDAY THROUGH WEDNESDAY...AND AGAIN ON FRIDAY. WEDGE CONDITIONS
DEVELOPING TUESDAY. ANOTHER COLD FRONT WILL CROSS THE REGION
WEDNESDAY. WEDGE CONDITIONS POSSIBLE AGAIN FRIDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
77
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
600 AM EST MON FEB 3 2014
.SYNOPSIS...
LOW PRESSURE WILL LIFT NORTHEAST OF THE FORECAST AREA TODAY. THE
TRAILING COLD FRONT WILL MOVE THROUGH THE AREA THIS AFTERNOON. THE
FRONT WILL STALL JUST SOUTH AND EAST OF THE AREA TONIGHT. ANOTHER
COLD FRONT APPROACHING FROM THE WEST WILL MOVE THROUGH THE REGION
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DESPITE HIGH LOW-LEVEL MOISTURE...CLOUDINESS AND MIXING SHOULD
LIMIT FOG EARLY THIS MORNING.
LOW PRESSURE WILL BE LIFTING NORTHEAST OF THE FORECAST AREA
TODAY. THE ASSOCIATED COLD FRONT WILL CROSS THE AREA THIS
AFTERNOON. CONVERGENCE ALONG AND AHEAD OF THE FRONT SUPPORTS
SHOWERS. THE SPC WRF AND HRRR INDICATE SHOWERS MOVING INTO THE
WEST PART OF THE FORECAST DURING THE 900 AM TO 1000 AM TIME FRAME.
THE HIGH-RESOLUTION MODELS SHOW SHOWER COVERAGE DECREASING
THEREAFTER. SATELLITE TRENDS WITH THE COLDER CLOUD TOPS SHIFTING
WELL NORTH OF THE FORECAST AREA SUPPORT THE MODEL FORECAST OF A
LOSS OF UPPER-LEVEL LIFT. WE FORECASTED LIKELY POPS IN THE WEST
PART AND JUST CHANCE POPS IN THE EAST PART TODAY.
SHEAR WILL BE HIGH WITH H85 WINDS NEAR 40 KNOTS. HOWEVER...THE
SEVERE THREAT APPEARS LOW BECAUSE OF A LACK OF SURFACE-BASED
INSTABILITY. THE NAM KEEPS SURFACE-BASED LI/S GREATER THAN 1 AND
THIS APPEARS REASONABLE BECAUSE OF CLOUDINESS AND MID-LEVEL
CAPPING. THE NAM AND GFS DISPLAY RISING H5 HEIGHTS TODAY.
THE TEMPERATURE GUIDANCE WAS CONSISTENT. BASED ON THE GFS LAMP
AND THE NAM TIME-HEIGHT DISPLAYS AND EXPECTED MIXING BELIEVE SOME
WIND GUSTS NEAR 20 KNOTS WILL OCCUR THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE FRONT WILL STALL JUST SOUTH AND EAST OF THE FORECAST AREA
TONIGHT. A WEDGE-RIDGE PATTERN WILL DOMINATE BEHIND THE FRONT
TONIGHT THROUGH TUESDAY NIGHT. ISENTROPIC LIFT WILL SUPPORT
CLOUDINESS AND A CHANCE OF RAIN. WE USED THE GUIDANCE CONSENSUS
FOR THE POP FORECAST. THE RAIN CHANCE SHOULD GRADUALLY INCREASE
WITH CONTINUED ISENTROPIC LIFT. THE TEMPERATURE GUIDANCE WAS
CONSISTENT BUT IS LIKELY TOO WARM TUESDAY BECAUSE OF THE WEDGE
PATTERN.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE MODELS DISPLAY ANOTHER COLD FRONT MOVING INTO THE FORECAST
AREA WEDNESDAY. WE LEANED TOWARD THE HIGHER ECMWF MOS AND
FORECASTED LIKELY POPS BECAUSE OF CONVERGENCE ASSOCIATED WITH THE
FRONT. THE NAM AND GFS MOS INDICATED LOWER POPS AND THIS MAY BE
CORRECT BECAUSE OF A LACK OF SIGNIFICANT UPPER-LEVEL LIFT.
CONFIDENCE IN THE POP FORECAST WEDNESDAY IS LOW. THE MODELS SHOW
JUST WEAK COLD ADVECTION BEHIND THE FRONT WEDNESDAY AFTERNOON.
EXPECT BREAKS IN THE CLOUDINESS SO AFTER A RELATIVELY WARM START...
THE NAM...GFS...AND ECMWF MOS TEMPERATURES APPEAR REASONABLE WITH
HIGHS NEAR 70.
THE MODELS SHOW BRIEF DRYING BEHIND THE FRONT THURSDAY...BUT A
RETURN TO ISENTROPIC LIFT AND DEEPER MOISTURE FRIDAY AND SATURDAY.
THE MODELS SHOW LOW PRESSURE NEAR THE AREA SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
LLWS HAS DEVELOPED EARLY THIS MORNING AHEAD OF AN APPROACHING COLD
FRONT. DUE TO MIXING AND CLOUDS...ANTICIPATE MAINLY MVFR CIGS THIS
MORNING. CIGS/VSBYS SHOULD IMPROVE SOMEWHAT AROUND 14Z WITH SHOWERS
MOVING INTO THE TAF SITES AHEAD OF AN APPROACHING COLD FRONT. HAVE
INDICATED SOUTHWEST WIND AROUND 10 KNOTS WITH GUSTS NEAR 20 KNOTS
AHEAD OF THE COLD FRONT WHICH IS SCHEDULED TO CROSS THE TAF SITES IN
THE 18Z-21Z TIME-FRAME. BY LATE IN THE TAF PERIOD...WINDS SHIFT TO
THE NORTHEAST AS WEDGE CONDITIONS DEVELOP FROM NORTH TO SOUTH.
EXTENDED AVIATION OUTLOOK... MVFR OR LOWER CONDITIONS POSSIBLE
TUESDAY THROUGH WEDNESDAY...AND AGAIN ON FRIDAY. WEDGE CONDITIONS
DEVELOPING TUESDAY. ANOTHER COLD FRONT WILL CROSS THE REGION
WEDNESDAY. WEDGE CONDITIONS POSSIBLE AGAIN FRIDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
534 AM CST Mon Feb 3 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 331 AM CST Mon Feb 3 2014
Cold high pressure will control our weather today, with a gradual
increase of high clouds expected during the afternoon. No major
changes to going temp trends, although did shave a couple of degrees
off on mid Missouri and the eastern Ozarks due to the cold start and
the increase of high clouds during the time of "max heating"...such
as it is in early February beneath a Canadian high...
Truett
.LONG TERM: (Tonight through Sunday)
Issued at 459 AM CST Mon Feb 3 2014
There are four primary forecast issues during this period: a winter
storm for Tu/Tu night, another Arctic air mass for W/Th, a weak vort
max moving across the area on Th/F, and another potential storm
system for Sa/Su.
Issue #1, winter storm for Tu/Tu night: Early morning water vapor
imagery and recent RAP analyses of the 1.5 PVU surface all show a
strong low pressure system just off the SoCal coast. The system was
partially sampled by 03/00z RAOBs in CA, but this feature`s path
through northern Mexico will likely preclude full sampling until it
reaches western TX around 12z Tu. This means that 1) models will
likely struggle to capture the true strength of the system, 2)
model depictions of the H5/H85/sfc low tracks may shift around a
bit, leading to changes in the forecast onset of precipitation as
well as changes to ptypes across southeast MO/southern IL, and 3)
last minute forecast adjustments to the axis of heaviest snowfall
may be required after the 12z models come in on Tue because those
runs will have incorporated the most recent upper air
observations.
Recent SREF/NAM/WRF/ECMWF/GEM runs depict H85 low tracks which match
very well with local climatology studies for heavy snowfall across
the northwest 1/3 of the CWA. BUFKIT soundings at KUIN, for example,
show a favorable cross-hair signature of rising motion within or
just below the DGZ occurring in an environment that is saturated wrt
ice. With at least ~50% confidence in heavy snow somewhere in the
northern or western part of the CWA, we have issued a Winter Storm
Watch (includes the Quincy and Columbia areas) from 12z Tue
through 12z Wed. The combination of initial WAA snow on Tue
followed by enhanced precipitation in the deformation zone on Tue
night could lead to snowfall totals of 6+" in or near this area.
Lesser snowfall totals (1-5") are possible across the rest of the
CWA (including the St. Louis metro area) due to WAA snow. Mixed
precipitation (including freezing rain and sleet) remains possible
on Tue, especially across the southeastern one-quarter of the CWA.
Any occurrence of sleet or freezing rain will reduce snowfall
totals. At this time, ice accretion of between a light glaze and
0.10" appears possible across the extreme southeastern CWA. Please
see the winter snow & ice graphics at
www.crh.noaa.gov/lsx/?n=stormtotalsnow for details.
Snow should taper off from west to east on late Tue night with some
lingering flurries possible on Wed afternoon.
Issue #2, Arctic air mass for W/Th: A 1040+ hPa surface high will
slide into the Plains on Tue night into Wed. The coldest
temperatures are expected from late Wed night into Thu morning,
especially over areas which will have received fresh snow cover.
Wind chill headlines may eventually be needed for northern portions
of the CWA due to wind chill values between -20 and -15 deg F from
late Wed night into Thu morning.
Issue #3, weak vort max for Th/F: Most models hint at a weak vort
max zipping through confluent flow aloft on Thu/Fri. There may be
enough forcing to squeeze out some light precipitation.
Issue #4, potential storm system for Sa/Su: ECMWF/GFS/GEM depict
the development of a highly elongated E-W trough/shear zone
spanning from OR to ME. A vort max peels off the western end near
WA/OR on Thu night and dives southeastward before swinging through
the south central CONUS over the weekend. This is a different
scenario compared to previous model runs which brought the
shortwave onshore from the Pacific. Chc PoPs are acceptable albeit
not preferable given this level of uncertainty at the end of the
extended forecast period.
Kanofsky
&&
.AVIATION: (For the 12z TAFs through 12z Tuesday Morning)
Issued at 535 AM CST Mon Feb 3 2014
VFR conditions will hold throughout this TAF cycle as Canadian
high slowly drifts east, with light northeast to east winds aob 6 kts.
There should be an increase in high level clouds this afternoon
and into tonight, but all ceilings should remain aoa 8kft. Early
indications are that cigs/vsbys will deteriorate fairly rapidly
into IFR over mid Missouri in the 12-15z time frame on Tuesday
with the developing snow, with these lower conditions pushing into
UIN by late morning.
Specifics for KSTL: Just a few afternoon cirrus clouds and
and north to northeast winds aob 6kts are expected today as the
Canadian high pushes into the lower Great Lakes. VFR conditions
will continue tonight as mid level clouds gradually thicken in
advance of Tuesday`s storm system, but at this time it appears that
the onset of the snow (and IFR cigs/vsbys) in STL may be delayed
until midday Tuesday as strong mid level lift will have to
saturate some very dry low level air before precip reaches the
ground. Snow still appears to be the dominate ptype, although some
sleet cannot totally be ruled out as models often seem to underestimate
the strength of the lower tropospheric WAA.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...WINTER STORM WATCH from Tuesday morning through late Tuesday
night FOR Audrain MO-Boone MO-Callaway MO-Cole MO-Knox MO-
Lewis MO-Lincoln MO-Marion MO-Moniteau MO-Monroe MO-
Montgomery MO-Pike MO-Ralls MO-Shelby MO.
IL...WINTER STORM WATCH from Tuesday morning through late Tuesday
night FOR Adams IL-Brown IL-Calhoun IL-Greene IL-Jersey IL-
Macoupin IL-Montgomery IL-Pike IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
509 AM CST Mon Feb 3 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 331 AM CST Mon Feb 3 2014
Cold high pressure will control our weather today, with a gradual
increase of high clouds expected during the afternoon. No major
changes to going temp trends, although did shave a couple of degrees
off on mid Missouri and the eastern Ozarks due to the cold start and
the increase of high clouds during the time of "max heating"...such
as it is in early February beneath a Canadian high...
Truett
.LONG TERM: (Tonight through Sunday)
Issued at 459 AM CST Mon Feb 3 2014
There are four primary forecast issues during this period: a winter
storm for Tu/Tu night, another Arctic air mass for W/Th, a weak vort
max moving across the area on Th/F, and another potential storm
system for Sa/Su.
Issue #1, winter storm for Tu/Tu night: Early morning water vapor
imagery and recent RAP analyses of the 1.5 PVU surface all show a
strong low pressure system just off the SoCal coast. The system was
partially sampled by 03/00z RAOBs in CA, but this feature`s path
through northern Mexico will likely preclude full sampling until it
reaches western TX around 12z Tu. This means that 1) models will
likely struggle to capture the true strength of the system, 2)
model depictions of the H5/H85/sfc low tracks may shift around a
bit, leading to changes in the forecast onset of precipitation as
well as changes to ptypes across southeast MO/southern IL, and 3)
last minute forecast adjustments to the axis of heaviest snowfall
may be required after the 12z models come in on Tue because those
runs will have incorporated the most recent upper air
observations.
Recent SREF/NAM/WRF/ECMWF/GEM runs depict H85 low tracks which match
very well with local climatology studies for heavy snowfall across
the northwest 1/3 of the CWA. BUFKIT soundings at KUIN, for example,
show a favorable cross-hair signature of rising motion within or
just below the DGZ occurring in an environment that is saturated wrt
ice. With at least ~50% confidence in heavy snow somewhere in the
northern or western part of the CWA, we have issued a Winter Storm
Watch (includes the Quincy and Columbia areas) from 12z Tue
through 12z Wed. The combination of initial WAA snow on Tue
followed by enhanced precipitation in the deformation zone on Tue
night could lead to snowfall totals of 6+" in or near this area.
Lesser snowfall totals (1-5") are possible across the rest of the
CWA (including the St. Louis metro area) due to WAA snow. Mixed
precipitation (including freezing rain and sleet) remains possible
on Tue, especially across the southeastern one-quarter of the CWA.
Any occurrence of sleet or freezing rain will reduce snowfall
totals. At this time, ice accretion of between a light glaze and
0.10" appears possible across the extreme southeastern CWA. Please
see the winter snow & ice graphics at
www.crh.noaa.gov/lsx/?n=stormtotalsnow for details.
Snow should taper off from west to east on late Tue night with some
lingering flurries possible on Wed afternoon.
Issue #2, Arctic air mass for W/Th: A 1040+ hPa surface high will
slide into the Plains on Tue night into Wed. The coldest
temperatures are expected from late Wed night into Thu morning,
especially over areas which will have received fresh snow cover.
Wind chill headlines may eventually be needed for northern portions
of the CWA due to wind chill values between -20 and -15 deg F from
late Wed night into Thu morning.
Issue #3, weak vort max for Th/F: Most models hint at a weak vort
max zipping through confluent flow aloft on Thu/Fri. There may be
enough forcing to squeeze out some light precipitation.
Issue #4, potential storm system for Sa/Su: ECMWF/GFS/GEM depict
the development of a highly elongated E-W trough/shear zone
spanning from OR to ME. A vort max peels off the western end near
WA/OR on Thu night and dives southeastward before swinging through
the south central CONUS over the weekend. This is a different
scenario compared to previous model runs which brought the
shortwave onshore from the Pacific. Chc PoPs are acceptable albeit
not preferable given this level of uncertainty at the end of the
extended forecast period.
Kanofsky
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1014 PM CST Sun Feb 2 2014
Mid-high level cloudiness has shifted se of UIN and COU this evng
and will continue to clear from nw to se late tgt out of the St
Louis metro area as the storm system s/se of our region shifts
further se, and a surface ridge extending from nern KS ne into
swrn WI and nwrn IL shifts slowly sewd. The broken low level
stratus clouds around 1300 ft in CPS should dissipate or advect
further se as the boundary layer moisture becomes more shallow.
Nly surface wind at STL and CPS will continue to weaken and become
lgt late tgt as they have already at the other taf sites, then
veer around to an e-nely direction Monday as the surface ridge
shifts east of the region. Mid-high level clouds will spread back
into the area Monday evng.
Specifics for KSTL: Mid-high level cloudiness will shift e-se of
STL late tgt. Nly surface wind will become lgt late tgt, then
veer around to an e-nely direction by Monday aftn or evng, albeit
remaining weak. Mid-high level clouds will spread back into the
area Monday evng with the cloud ceiling lowering late Monday ngt.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...WINTER STORM WATCH from Tuesday morning through late Tuesday
night FOR Audrain MO-Boone MO-Callaway MO-Cole MO-Knox MO-
Lewis MO-Lincoln MO-Marion MO-Moniteau MO-Monroe MO-
Montgomery MO-Pike MO-Ralls MO-Shelby MO.
IL...WINTER STORM WATCH from Tuesday morning through late Tuesday
night FOR Adams IL-Brown IL-Calhoun IL-Greene IL-Jersey IL-
Macoupin IL-Montgomery IL-Pike IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
530 AM CST MON FEB 3 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM CST MON FEB 3 2014
TODAY AND TONIGHT...SOME TRAPPED MOISTURE HAS DEVELOPED IN THE
PLATTE VALLEY THIS MORNING NEAR KOGA/NEDOR CAM AT OGALLALA. THE SNOW
FIELD HAS DEFIED ALL MODEL PREDICTIONS AND MAINTAINED A WEAK SFC
HIGH PRESSURE RIDGE NORTHWEST THROUGH THE PANHANDLE. NOT EVEN THE
RAP13 CAPTURES THIS FEATURE THIS MORNING. SO DENSE FOG ADVISORY IS
IN PLACE FOR KEITH AND DEUEL COUNTIES UNTIL 15Z THIS AM.
A WARM FRONT IS DEVELOPING THIS MORNING BUT IT IS ACROSS ERN
COLO/NWRN KS. THIS FRONT IS EXPECTED TO LIFT NORTH INTO WRN NEB
LATER TODAY AS AN ARCTIC FRONT...CURRENTLY MOVING THROUGH EDMONTON
ALBERTA...MOVES INTO MT. THIS FRONT WILL MERELY RECYCLE COLD AIR
NORTH WITH SOUTHEAST WIND AND VERY LIMITED VERTICAL MIXING.
BUT THERE IS MORE. THE NAM...GEM REGIONAL...RAP13 AND HRRR POOL
MOISTURE ALONG THE WARM FRONT AND PRODUCE SNOW AS THE FRONT LIFTS
INTO NCNTL NEB THIS MORNING AND THIS AFTERNOON. THE NAM SUGGEST
FLURRIES WHILE THE RAP AND HRRR SHOW SNOW ACCUMULATIONS OF AN INCH
OR LESS. HMMM...GIVEN THAT THE MODELS ARE HAVING TROUBLE CORRECTLY
ESTABLISHING A WARM SECTOR ON THE SNOW COVER AND SKY CONDITIONS ARE
CURRENTLY VFR EXCEPT FOR GROUND FOG...THE FORECAST IS VERY UNCERTAIN
TODAY BUT WE WILL TRY A 30 POP FOR SNOW SHOWERS AS THE FRONT LIFTS
NORTH. FORECAST ERRORS COULD BE LARGE WITH THIS ONE.
FCST HIGHS TODAY RANGE FROM THE UPPER 20S ACROSS THE SOUTH AND WEST
TO LOWER 30S NORTH AND EAST WHERE NO SNOW IS ON THE GROUND.
FOR TONIGHT...GET READY. AN ARCTIC FRONT WILL MOVE THROUGH THE FCST
AREA. THE FRONT IS A SLOW MOVER AND SFC WINDS BACK AROUND AND BECOME
NORTHEAST PRODUCING UPSLOPE WINDS AND A RAPID INCREASE IN RELATIVE
HUMIDITY BELOW 700 MB. TEMPERATURES 850MB-700MB FALL TO AROUND -14C
BEHIND THE FRONT SUPPORTING SNOW GROWTH WHILE THE UPSLOPE WINDS
PRODUCE WEAK LIFT. SNOW CHANCES INCREASE TO AROUND 50 PERCENT BY 12Z
TUESDAY MORNING AND SNOWFALL AMOUNTS SHOULD BE LESS THAN AN INCH.
LOWS TONIGHT SHOULD RANGE FROM SINGLE DIGITS NORTH TO AROUND 15F
SOUTH AND EAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 402 AM CST MON FEB 3 2014
12Z TUESDAY AND BEYOND. THE FOCUS OF THE EXTENDED FORECAST
CENTERS ON A PROLONGED PERIOD OF BITTERLY COLD TEMPERATURES AND
THE POTENTIAL OF SNOW MID-WEEK. MEDIUM RANGE FORECAST MODELS
REMAIN IN GOOD AGREEMENT WITH THE HANDLING OF THE SOUTHERN STREAM
SHORTWAVE. THE WAVE WILL ROTATE FROM THE SOUTHERN ROCKIES OUT ONTO
THE PLAINS ON TUESDAY...ALLOWING FOR WIDESPREAD SNOW ACROSS THE
REGION. THE MODELS CONTINUE TO FOCUS THE HEAVIEST QPF AND BEST
SNOW POTENTIAL SOUTH AND EAST OF THE CWA WITH THE TRACK OF THE H5
LOW FROM SOUTHWEST KANSAS INTO FAR SOUTHEAST NEBRASKA. HOWEVER
THERE CONTINUES TO BE SUPPORT OF INCREASING DPVA AND WEAK UPGLIDE
TARGETING PORTIONS OF THE FORECAST AREA THROUGH THE DAY ON
TUESDAY. THE HEAVIEST ANTICIPATED QPF ACROSS OUR CWA WILL BE FOUND
FROM SW NEB THROUGH SOUTHERN CUSTER COUNTY...BUT AT THAT THE MODEL
CONSENSUS ONLY SUGGESTS ~0.15" TOTAL QPF /WHICH IS DEEMED TOO
HIGH/. PROXIMITY SOUNDINGS FROM THIS AREA REVEAL A FAIRLY
EFFICIENT SNOW PRODUCING PROFILE AS A LARGE COLUMN OF SATURATED
AIR WILL BE CO-LOCATED WITHIN OMEGA AND FAVORABLE TEMPERATURES OF
-10 TO -18C. USING A 15-17:1 SLR INDICATES TWO OR THREE INCHES OF
SNOW POSSIBLE BY WEDNESDAY MORNING FOR OUR SOUTHEASTERN ZONES.
FURTHER WEST...ACROSS THE EASTERN PANHANDLE AND MUCH OF THE
SANDHILLS REGION...LIGHT SNOW WILL BE POSSIBLE AS THE NORTHERN
STREAM USHERS A TROUGH ACROSS WYOMING AND MONTANA. QPF WILL BE
LIGHTER WITH THIS SYSTEM...BUT GIVEN THE HIGH SLR/S AND THE
POTENTIAL OF 12+ HOURS OF LIGHT SNOW...AN INCH WITH LOCALIZED
HEAVIER AMOUNTS IS POSSIBLE. IN ADDITION TO THE LIGHT
SNOW...NORTHERLY WINDS MAY CAUSE SOME LOCALIZED BLOWING SNOW WITH
REDUCED VISIBILITY. ATTM THE STRONGEST GUSTS /UP TO 25 MPH/
TUESDAY LOOK TO REMAIN ACROSS EASTERN PORTIONS OF THE FORECAST
AREA. SNOW PRODUCTION WILL TAPER OFF QUICKLY WEDNESDAY MORNING AS
DRY AIR IS PULLED SOUTH BEHIND THE PASSING WAVE AND FORCING
SPREADS EAST.
ONTO TEMPERATURES AND SLIGHT CHANCE POPS LATE WEEK...ARCTIC AIR WILL BE
IN PLACE ACROSS THE CWA ON TUESDAY WITH HIGHS OF ONLY 8-15 ABOVE
ZERO. THESE TEMPERATURES WILL BE WARM COMPARED TO THE OVERNIGHT AND
WEDNESDAY AS ARCTIC AIR CONTINUES TO FILTER SOUTHEAST THROUGH THE
HIGH PLAINS. BY WEDNESDAY MORNING...H85 TEMPERATURES OF MINUS 22 OR
COLDER WILL BE ATOP THE REGION...WITH WIDESPREAD SUB-ZERO SFC
TEMPERATURES ANTICIPATED. HIGHS ON WEDNESDAY WILL REMAIN IN THE
SINGLE DIGITS FOR ALL LOCATIONS ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA. OVERNIGHT WEDNESDAY AND EARLY THURSDAY SHOULD BE THE
COLDEST PERIOD OF THE EXTENDED...AND POSSIBLY THIS ENTIRE WINTER
SEASON. RIGHT NOW MODEL GUIDANCE IS INDICATING THE POTENTIAL OF
MINUS 5 TO MINUS 15 FROM EAST TO WEST RESPECTIVELY...WHICH MAY BE
WARM GIVEN THE PROJECTED LOCATION OF THE ARCTIC HIGH AND POTENTIAL
FRESH SNOWPACK. TRENDED THE FORECAST FOR THE WEDNESDAY THROUGH
FRIDAY MORNING TIMEFRAME TOWARD THE BCGEMREG /DUE TO ITS RECENT
PERFORMANCE/ AND THE ADJMEXBC AS THE GFS SEEMS TO BE HEADING IN THE
RIGHT DIRECTION. WITH THE BITTERLY COLD TEMPERATURES ANY AMOUNT OF
WIND WOULD ALLOW FOR CRITICALLY LOW WIND CHILL READINGS. WIND CHILL
ADVISORIES MAY BE NEEDED WEDNESDAY THROUGH THURSDAY MORNING.
TEMPERATURES SLOWLY MODERATE LATE WEEK INTO NEXT WEEKEND IN ADVANCE
OF THE NEXT TROUGH OF LOW PRESSURE ORGANIZING ACROSS THE WESTERN
STATES. THIS TROUGH IS SHOWN TO REMAIN PROGRESSIVE WITH MOST OF
IT/S ENERGY AFFECTING THE SOUTHERN PLAINS. FOR NOW WILL MAINTAIN
SLIGHT CHANCE POPS FRIDAY INTO SATURDAY. OTHERWISE TEMPERATURES
WILL SLOWLY MODERATE INTO THE WEEKEND...BUT REMAIN WELL BELOW
AVERAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 530 AM CST MON FEB 3 2014
VERY UNCERTAIN FORECAST IN SOME WAYS TODAY. ONE IS THAT THE
MODELS ARE FCST WIDESPREAD MVFR TODAY BUT THERE IS NONE SHOWN ON
THE SATELLITE CURRENTLY. ANOTHER WAY IS THE BANK OF OVC060 CLOUDS
OVER KLBF ARE EXPECTED TO LIFT NORTH...EXPAND IN AREAL COVERAGE
AND PRODUCE MVFR AND LIGHT SNOW THIS MORNING AND THIS AFTERNOON.
THE FORECAST TODAY IS FOR AREAS OF MVFR DEVELOPING ACROSS NCNTL
NEB EAST OF HIGHWAY 83 WITH LOCAL IFR IN SHSN. THE LIFR ACROSS
KOGA SHOW LIFT TO VFR 15Z-16Z. OTHERWISE...VFR IS EXPECTED TODAY.
TONIGHT...AN ARCTIC FRONT ACROSS SRN ALBERTA WILL BE ROLLING
THROUGH THE FCST AREA PRODUCING WIDESPREAD MVFR/IFR CIGS IN LIGHT
SNOW. FORECAST CONFIDENCE IS GOOD WITH THIS PORTION FOR THE
AVIATION FORECAST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 8 AM MST THIS MORNING FOR NEZ056-057.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
650 AM EST MON FEB 3 2014
.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING SNOW TO THE SOUTHERN
AND EASTERN HALF OF THE STATE THIS MORNING. THEY HEAVIEST SNOWS
WILL FALL DURING THE MORNING COMMUTE LASTING THROUGH THE MORNING
HOURS. THOSE DRIVING IN THE CAPITOL DISTRICT...YORK AND LANCASTER
WILL NEED TO PREPARE FOR HAZARDOUS WINTER WEATHER DRIVING
CONDITIONS THIS MORNING. LOOK FOR IMPROVING CONDITIONS THIS
AFTERNOON AS HIGH PRESSURE BRIEFLY BUILDS ACROSS THE REGION. A
STRONGER AND MORE DYNAMIC WINTER STORM SYSTEM WILL IMPACT THE AREA
FROM TUESDAY NIGHT INTO WEDNESDAY...WITH THE POTENTIAL FOR
SIGNIFICANT SNOW AND ICE. DRY WEATHER AND BELOW NORMAL
TEMPERATURES SHOULD FINISH OUT THE SECOND HALF OF THE WEEK.
ANOTHER WINTER STORM SYSTEM MAY AFFECT THE AREA SOMETIME OVER THE
WEEKEND OR INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ANOTHER CHALLENGING FORECAST THIS WINTER. MAIN IMPACT FROM
DISTURBANCE MOVING INTO SOUTHERN ZONES EARLY THIS MORNING. ANY
RAIN WILL QUICKLY TURN OVER TO SNOW BEFORE SUNRISE. LATEST SHORT
TERM GUIDANCE INCLUDING LAST FEW HRRR RUNS SHOW A SHORT PERIOD OF
VERY HEAVY SNOWS ACROSS SE QUARTER OF CWA AND EXPANDED THE WSW
INTO THE HARRISBURG METRO AREA. MORNING COMMUTE WILL BE QUITE
TREACHEROUS ACROSS THIS AREA AS HEAVIEST SNOWS LOOK TO FALL DURING
THIS PERIOD. TOUGHEST PART OF FORECAST WILL BE FORECASTING SNOW
FOR THE NORTHERN EDGE OF THIS SYSTEM. RADAR TRENDS SHOW SHOWN A
SHARP CUTOFF IN INTENSITIES NORTH OF A CAMBRIA THROUGH CENTRE
COUNTY LINE. SNOW WILL REMAIN LIGHT NORTH OF THIS LINE
SIGNIFICANTLY LIMITING ACCUMULATIONS. WILL MONITOR CLOSELY IN CASE
THIS LINE SHIFTS NORTH...BUT SO FAR IT HAS NOT. WAVE WILL QUICKLY
MOVE EAST OF CWA BY THE EARLY AFTERNOON. SNOW WILL QUICKLY TAPER
OFF THOUGH TEMPERATURES WILL MOVE LITTLE THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
HIGH PRESSURE WILL BRING A QUIET NIGHT TO THE AREA WITH COLDER
LOWS GIVEN THE COLDER AIR MASS AND DECENT CONDITIONS FOR
RADIATIONAL COOLING.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
VERY ACTIVE AND CHALLENGING PERIOD OF WEATHER FOR THE EXTENDED
PERIOD. AFTER A QUIET WEATHER DAY ON TUESDAY HIGH PRESSURE QUICKLY
RETREATS NE AND THE NEXT WINTER STORM APPROACHES THE REGION
TUESDAY NIGHT AND WEDNESDAY. LATEST ENSEMBLE GUIDANCE SHOWS A
COLD STORM WITH A WIDE VARIETY OF PRECIPITATION SCENARIOS
POSSIBLE...DEPENDING ON THE TRACK OF THE SURFACE LOW. WIDE RANGE
OF MODEL GUIDANCE AND THE TRACK IS STILL UNCERTAIN. GEFS GUIDANCE
HAS THE BEST CHANCES OF LIQUID PRECIPITATION...INCLUDING FREEZING
RAIN OR PLAIN RAIN IN THE SOUTHEAST ZONES. IN THE CENTRAL ZONES
INCLUDING THE STATE COLLEGE AREA...PRECIP TYPES VERY CHALLENGING
WITH SIGNIFICANT SNOW FALL AND PERHAPS A PERIOD OF SLEET OR
FREEZING RAIN MIXED IN TO ADD TO THE COMPLEXITY OF THE FORECAST.
AS YOU HEAD TO THE NORTHERN ZONES THE CHANCES OF THE PRECIPITATION
REMAINING ENTIRELY AS SNOW INCREASE. FOR NOW HAVE NOT ISSUED ANY
HIGHLIGHTS FOR THIS STORM GIVEN THE LARGE AMOUNT OF UNCERTAINTY
THAT SILL EXISTS. AFTER THE STORM EXITS THE CWA ON WEDNESDAY NIGHT
THERE WILL BE A COUPLE DAY BREAK...THOUGH TEMPERATURES WILL BE
QUITE COLD TO END THE WORK WEEK...LIKELY BELOW FREEZING ACROSS THE
ENTIRE CWA. ANOTHER STORM SYSTEM IS FORECAST TO ARRIVE SOMETIME
NEXT WEEKEND...THOUGH TIMING IS STILL IN QUESTION. LATEST GUIDANCE
APPEARS TO PUSH IT BACK INTO THE SUNDAY OR MONDAY TIME FRAME.
THERMAL PROFILES AGAIN COLD WITH THE SYSTEM AND EXPECT ANOTHER
CHALLENGING FORECAST NARROWING DOWN THE EXPECTED IMPACTS. STILL
PLENTY OF TIME TO SEE HOW THAT EVOLVES.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
BANDS OF HEAVY SNOW WILL CONTINUE UNITL LATE MORNING
ACROSS THE WEST AND CENTRAL AREAS...AND EARLY AFT
ACROSS THE EAST. LIFR.
SKIES WILL CLEAR LATER THIS AFTERNOON...AS HIGH PRESSURE
WORKS EASTWARD. SOME HINTS OF SOME LOWER CLDS AND FOG
COULD LINGER AT JST INTO TONIGHT.
TUESDAY STARTS OFF WITH LOTS OF SUN...BUT CLDS COME IN
FAST...AS A COMPLEX STORM SYSTEM TRACKS NE TOWARD THE
OH VLY.
A FAST MOVING AREA OF PRECIPITATION WILL OVERSPREAD
THE AREA TUESDAY NIGHT. SOME VARIATION IN MODEL
SOLUTIONS...BUT THE SYSTEM WILL BE MOVING FAST AND
A LOT OF WARM AIR WILL BE MOVING IN AT MID LVLS...THUS
SLEET COULD OCCUR FOR MUCH OF THE TIME.
HOWEVER...WOULD EXPECT A MIXTURE OF SOME SNOW...RAIN...
AND FREEZING RAIN AS WELL.
CONDITIONS IMPROVE LATER WED...AS HIGH PRESSURE WORKS
EASTWARD.
OUTLOOK...
TUE...MAINLY VFR.
TUE NIGHT-WED...WIDESPREAD IFR LIKELY IN MIXED PCPN.
THU-FRI...MVFR W AND N WITH SCT SNOW SHOWERS...MVFR TO VFR CENTRAL
AND SOUTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ024>028-050-052-058.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ033>036-056-057-059-063>066.
&&
$$
SYNOPSIS...ROSS
NEAR TERM...ROSS
SHORT TERM...ROSS
LONG TERM...ROSS
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
643 AM EST MON FEB 3 2014
.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING SNOW TO THE SOUTHERN
AND EASTERN HALF OF THE STATE THIS MORNING. THEY HEAVIEST SNOWS
WILL FALL DURING THE MORNING COMMUTE LASTING THROUGH THE MORNING
HOURS. THOSE DRIVING IN THE CAPITOL DISTRICT...YORK AND LANCASTER
WILL NEED TO PREPARE FOR HAZARDOUS WINTER WEATHER DRIVING
CONDITIONS THIS MORNING. LOOK FOR IMPROVING CONDITIONS THIS
AFTERNOON AS HIGH PRESSURE BRIEFLY BUILDS ACROSS THE REGION. A
STRONGER AND MORE DYNAMIC WINTER STORM SYSTEM WILL IMPACT THE AREA
FROM TUESDAY NIGHT INTO WEDNESDAY...WITH THE POTENTIAL FOR
SIGNIFICANT SNOW AND ICE. DRY WEATHER AND BELOW NORMAL
TEMPERATURES SHOULD FINISH OUT THE SECOND HALF OF THE WEEK.
ANOTHER WINTER STORM SYSTEM MAY AFFECT THE AREA SOMETIME OVER THE
WEEKEND OR INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
630AM UPDATE...NO SIG CHANGES TO FORECAST AS SNOW QUICKLY BECOMING
DOMINANT PRECIP TYPE ACROSS THE CWA. EXPECT MOD-HVY SNOW FOR THE
CAP CITY REGION FOR THE NEXT SEVERAL HOURS. NORTHERN EDGE OF SNOW
INTO CENTRE COUNTY.
ANOTHER CHALLENGING FORECAST THIS WINTER. MAIN IMPACT FROM
DISTURBANCE MOVING INTO SOUTHERN ZONES EARLY THIS MORNING. ANY
RAIN WILL QUICKLY TURN OVER TO SNOW BEFORE SUNRISE. LATEST SHORT
TERM GUIDANCE INCLUDING LAST FEW HRRR RUNS SHOW A SHORT PERIOD OF
VERY HEAVY SNOWS ACROSS SE QUARTER OF CWA AND EXPANDED THE WSW
INTO THE HARRISBURG METRO AREA. MORNING COMMUTE WILL BE QUITE
TREACHEROUS ACROSS THIS AREA AS HEAVIEST SNOWS LOOK TO FALL DURING
THIS PERIOD. TOUGHEST PART OF FORECAST WILL BE FORECASTING SNOW
FOR THE NORTHERN EDGE OF THIS SYSTEM. RADAR TRENDS SHOW SHOWN A
SHARP CUTOFF IN INTENSITIES NORTH OF A CAMBRIA THROUGH CENTRE
COUNTY LINE. SNOW WILL REMAIN LIGHT NORTH OF THIS LINE
SIGNIFICANTLY LIMITING ACCUMULATIONS. WILL MONITOR CLOSELY IN CASE
THIS LINE SHIFTS NORTH...BUT SO FAR IT HAS NOT. WAVE WILL QUICKLY
MOVE EAST OF CWA BY THE EARLY AFTERNOON. SNOW WILL QUICKLY TAPER
OFF THOUGH TEMPERATURES WILL MOVE LITTLE THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
HIGH PRESSURE WILL BRING A QUIET NIGHT TO THE AREA WITH COLDER
LOWS GIVEN THE COLDER AIR MASS AND DECENT CONDITIONS FOR RADIATIONAL
COOLING.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
VERY ACTIVE AND CHALLENGING PERIOD OF WEATHER FOR THE EXTENDED
PERIOD. AFTER A QUIET WEATHER DAY ON TUESDAY HIGH PRESSURE QUICKLY
RETREATS NE AND THE NEXT WINTER STORM APPROACHES THE REGION
TUESDAY NIGHT AND WEDNESDAY. LATEST ENSEMBLE GUIDANCE SHOWS A
COLD STORM WITH A WIDE VARIETY OF PRECIPITATION SCENARIOS
POSSIBLE...DEPENDING ON THE TRACK OF THE SURFACE LOW. WIDE RANGE
OF MODEL GUIDANCE AND THE TRACK IS STILL UNCERTAIN. GEFS GUIDANCE
HAS THE BEST CHANCES OF LIQUID PRECIPITATION...INCLUDING FREEZING
RAIN OR PLAIN RAIN IN THE SOUTHEAST ZONES. IN THE CENTRAL ZONES INCLUDING
THE STATE COLLEGE AREA...PRECIP TYPES VERY CHALLENGING WITH
SIGNIFICANT SNOW FALL AND PERHAPS A PERIOD OF SLEET OR FREEZING
RAIN MIXED IN TO ADD TO THE COMPLEXITY OF THE FORECAST. AS YOU
HEAD TO THE NORTHERN ZONES THE CHANCES OF THE PRECIPITATION
REMAINING ENTIRELY AS SNOW INCREASE. FOR NOW HAVE NOT ISSUED ANY
HIGHLIGHTS FOR THIS STORM GIVEN THE LARGE AMOUNT OF UNCERTAINTY
THAT SILL EXISTS. AFTER THE STORM EXITS THE CWA ON WEDNESDAY
NIGHT THERE WILL BE A COUPLE DAY BREAK...THOUGH TEMPERATURES WILL
BE QUITE COLD TO END THE WORK WEEK...LIKELY BELOW FREEZING ACROSS
THE ENTIRE CWA. ANOTHER STORM SYSTEM IS FORECAST TO ARRIVE
SOMETIME NEXT WEEKEND...THOUGH TIMING IS STILL IN QUESTION. LATEST
GUIDANCE APPEARS TO PUSH IT BACK INTO THE SUNDAY OR MONDAY TIME
FRAME. THERMAL PROFILES AGAIN COLD WITH THE SYSTEM AND EXPECT
ANOTHER CHALLENGING FORECAST NARROWING DOWN THE EXPECTED IMPACTS.
STILL PLENTY OF TIME TO SEE HOW THAT EVOLVES.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
BANDS OF HEAVY SNOW ACROSS SOUTHERN PA AS OF 09Z.
EXPECT POOR CONDITIONS TO LINGER INTO LATE MORNING.
CONDITIONS WILL IMPROVE THIS AFT...AS STORM TRACKING
ALONG THE COLD FRONT TO THE SOUTH OF PA MOVES EAST
OF THE AREA.
09Z TAFS ADJUSTED FOR THE BANDS OF HEAVY SNOW.
EARLIER DISCUSSION BELOW.
FIRST OF THE SNOW WITH THE APPROACHING STORM NOW INVADING
SOUTHWEST PENNSYLVANIA. SNOW TO INCREASE RAPIDLY...AND BECOME
HEAVY OVERNIGHT AND EARLY MONDAY ACROSS THE SOUTHERN AIRFIELDS.
LATER MODEL RUNS CONTINUE TO INCREASE QPF AND RESULTANT SNOW.
EXPECTING A WINDOW OF MODERATE TO PERHAPS HEAVY SNOW IN SOUTHERN
AIRFIELDS TOMORROW FROM ABOUT 12Z TO 16Z. HAVE ADJUSTED TAFS TO
LOWER CIGS AND VSBYS.
PRECIPITATION MOVES OUT QUICKLY MONDAY AFTERNOON AND EVENING...
WITH A RETURN TO VFR CONDITIONS AT ALL LOCATIONS BEFORE 00Z
TUESDAY.
BRIEF PERIOD OF VFR CONDITIONS TUESDAY...BEFORE NEXT SYSTEM MOVES
IN TUESDAY NIGHT AND WEDNESDAY.
OUTLOOK...
TUE...MAINLY VFR.
TUE NIGHT-WED...WIDESPREAD IFR LIKELY IN MIXED PCPN.
THU...MVFR W AND N WITH SCT SNOW SHOWERS...MVFR TO VFR CENTRAL AND
SOUTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ024>028-050-052-058.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ033>036-056-057-059-063>066.
&&
$$
SYNOPSIS...ROSS
NEAR TERM...ROSS
SHORT TERM...ROSS
LONG TERM...ROSS
AVIATION...JUNG/MARTIN
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
230 PM MST MON FEB 3 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE INTO NEW MEXICO TONIGHT BUT A VERY
SLIGHT CHANCE OF SHOWERS WILL LINGER THROUGH TUESDAY...WELL EAST OF
PHOENIX. CONDITIONS WILL BE DRY WEDNESDAY INTO THURSDAY BEFORE
ANOTHER SYSTEM MOVES THROUGH THE REGION THURSDAY NIGHT INTO SATURDAY
MORNING. PRECIPITATION CHANCES WITH THIS SECOND SYSTEM WILL BE
FOCUSED EAST OF THE LOWER COLORADO RIVER VALLEY. HIGH TEMPERATURES
WILL BE BELOW NORMAL THIS WEEK...ESPECIALLY TODAY AND FRIDAY.
&&
.DISCUSSION...
TWO VORT MAXES EMBEDDED WITHIN THE TROUGH ARE APPARENT ON
SATELLITE...ONE ACROSS YAVAPAI COUNTY AND ANOTHER ACROSS NORTHERN
SONORA. LATEST HI-RES HRRR INDICATES THAT ISOLATED CONVECTION WILL
DEVELOP AHEAD OF THE SOUTHERN-MOST VORT IN SE AZ LATE THIS AFTERNOON
BUT ACROSS SOUTH-CENTRAL AZ...THE POTENTIAL FOR MEASURABLE PRECIP IS
QUITE LOW. SURFACE DEWPOINTS ARE GENERALLY IN THE UPPER TEENS AND AS
LOW AS THE LOWER TEENS NEAR GILA BEND.
GIVEN THE WIDESPREAD WEAK ASCENT AHEAD OF THE TROUGH AXIS AND THE
DRY SUB-CLOUD ENVIRONMENT...VIRGA HAS BEEN OBSERVED IN A FEW SPOTS.
POPS WERE LOWERED FOR THIS EVENING...THOUGH THERE IS THE POSSIBILITY
OF A FEW SPRINKLES...PARTICULARLY ACROSS THE HIGHER ELEVATIONS NORTH
AND EAST OF PHOENIX. OTHERWISE...SKIES WILL CLEAR FROM WEST TO EAST
OVERNIGHT AND WITH LIGHT WINDS AND INCREASING RADIATIONAL
COOLING...BELOW NORMAL TEMPERATURES ARE EXPECTED.
&&
.PREVIOUS DISCUSSION...
TUESDAY THROUGH THURSDAY...
MODELS AGREE THAT UPPER TROUGHING WILL REMAIN CENTERED OVER THE
NORTHWEST STATES THROUGH THURSDAY WITH MINOR SHORT WAVES PASSING
OVER OUR AREA EMBEDDED IN THE WEST AND NORTHWESTERLY FLOW ALOFT.
THUS ONLY SLIGHT WARMING.
THURSDAY NIGHT THROUGH SUNDAY...
MODELS GENERALLY AGREE ON THE IDEA OF AN UPPER LOW MOVING FROM THE
PACIFIC NORTHWEST STATES INTO THE GREAT BASIN AND DESERT SOUTHWEST
THURSDAY NIGHT AND FRIDAY...EXITING SATURDAY. HOWEVER...THERE ARE
CONSIDERABLE DIFFERENCES AMONGST THE ECMWF...GFS...AND GEM. THE
ECMWF IS TAKES IT DEEPER INTO THE DESERT SOUTHWEST THAN THE GFS WITH
THE GEM BEING EVEN WEAKER AND FASTER. THE 00Z ECMWF IS STRONGER WITH
RESPECT TO ITS 12Z RUN AS WELL AS ITS ENSEMBLE MEAN FROM 12Z. THE
GFS IS CLOSER TO ITS ENSEMBLE MEAN BUT THAT IS OFTEN THE CASE GIVEN
THE SMALLER NUMBER OF PERTURBATIONS IN THE GEFS. TAKING A BLENDED
APPROACH...AND IN COORDINATION WITH NEIGHBORING OFFICES...NUDGED
POPS UPWARD FOR FRIDAY OVER SOUTH-CENTRAL ARIZONA...MAINLY OVER ZONE
24. TURNS OUT THAT DESPITE NOTABLE DIFFERENCES AMONGST THE MODELS
THERE ARE SIMILARITIES IN THE PLACEMENT OF THE QPF...AMOUNTS VARY
CONSIDERABLY THOUGH. BY THAT SAME TOKEN...DECREASED POPS OVER OUR
WESTERN AREAS PER MODEL AGREEMENT. MOISTURE FIELDS ARE NOT THAT
IMPRESSIVE WITH ANY OF THE MODELS WHICH IS NOT SURPRISING GIVEN THE
OVERLAND TRACK. BUT WITH COLD AIR AND FRONTAL
PASSAGE...PRECIPITATION EFFICIENCY WILL BE IMPROVED. THE COLDEST
MORNINGS SHOULD BE SATURDAY AND SUNDAY WITH UPPER 20S POSSIBLE ON
THE COLDEST LOW ELEVATION DESERTS...NEAR 30 POSSIBLE COLDEST METRO
LOCATIONS. HIGH TEMPERATURES WILL TREND UPWARD NEXT WEEKEND.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...AND KSDL...
LOW PRESSURE SYSTEM WILL MOVE TO THE EAST THIS EVENING...BUT
LINGERING SHOWERS TO THE NORTH AND EAST OF THE METRO PHOENIX AREA
WILL REMAIN INTO TONIGHT. BROKEN CLOUDS WITH DECKS BETWEEN 8-10K
FEET THIS AFTERNOON WILL IMPROVE TO JUST FEW TO SCATTERED BY THIS
EVENING BUT LAST INTO TUESDAY. LIGHT WINDS ARE EXPECTED THROUGH THE
TAF PERIOD AND SHOULD GENERALLY FOLLOW TYPICAL DIURNAL WIND SHIFTS.
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
CLEAR TO MOSTLY CLEAR SKIES THROUGH TONIGHT AND ANY CLOUDS THAT DO
DEVELOP WILL ONLY BE FEW TO SCATTERED IN COVERAGE AND HAVE BASES
AROUND 10K FEET. WINDS THROUGH THE PERIOD WILL GENERALLY BE FROM A
NORTHWESTERLY DIRECTION AND REMAIN LESS THAN 10 KNOTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
LONGWAVE TROUGH OVER THE WESTERN CONUS WILL RESULT IN A CONTINUED
PERIOD OF BELOW NORMAL TEMPERATURES AND ELEVATED HUMIDITIES THROUGH
THE END OF THE WEEK. MODELS AGREE ON A RATHER LARGE LOW MOVING
THROUGH THE GREAT BASIN ON FRIDAY...RESULTING IN AT LEAST A CHANCE
OF MOUNTAIN SHOWERS EAST OF PHOENIX...POSSIBLY REACHING THE LOWER
DESERTS AS WELL. COULD ALSO SEE SOME RIDGE-TOP BREEZINESS WITH THIS
LOW ON FRIDAY. WILL NEED TO SEE IF THE MODELS REMAIN CONSISTENT WITH
THIS SYSTEM. COOL TEMPERATURES WILL REMAIN IN PLACE ACROSS THE AREA
FOLLOWING THIS LOW NEXT WEEKEND ALONG WITH ELEVATED HUMIDITIES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...AJ
AVIATION...KUHLMAN
FIRE WEATHER...LEINS
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1104 AM MST MON FEB 3 2014
.UPDATE...
ISSUED AT 1104 AM MST MON FEB 3 2014
NRN AND SRN STREAM HAS MERGED ACROSS THE CENTRAL PORTION OF THE
FORECAST AERA...BASICALLY ALONG THE I70 CORRIDOR WITH STEADY LIGHT
SNOW PERSISTANT ACROSS THIS AREA. THIS DEFORMATION ZONE WEAKENS
THIS AFTERNOON AND FALLS APART LATE IN THE DAY. MODELS CONTINUE TO
SHOW SOME SHALLOW CONVECTIVE POTENTIAL...SUGGESTING SOME UPDRAFTS
WITH CONVECTIVE BURSTS OF SNOW. THE ENVIRONMENT WILL CHANGE FROM A
STRATIFORM SNOWFALL TO TERRAIN HUGGING SNOW SHOWERS BY LATE IN THE
DAY. THE RAP MODEL SHOWS THIS TRANSITION BETWEEN 1 PM AND 4 PM
THIS AFTERNOON. BY TONIGHT...AREAL COVERAGE OF SNOW WILL BE
EXPANDING AS THE UPSTREAM NEGATIVE TILT TROUGH SLIDES TOWARD UTAH
AND WRN COLORADO. EXPECT LIGHT SNOW TO BECOME WIDESPREAD ACROSS
THE FORECAST AREA...WITH THE POSSIBLE EXCEPTION OF EXTREME SERN
UTAH. WILL BE CONSIDERING ISSUING WINTER WEATHER ADVISORIES FOR
VALLEY LOCATIONS...BUT NO DECISION HAS BEEN MADE YET.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 356 AM MST MON FEB 3 2014
A COMPACT UPPER LOW OVER SRN CA WILL SWING ACROSS SRN AZ/NM TODAY
AND TONIGHT AS AN OPEN WAVE SPREADING SNOW INTO THE SOUTHERN AND
CENTRAL MOUNTAINS THIS MORNING. BEST Q-G FORCING STAYS TO OUR
SOUTH AND ISENTROPIC UPGLIDE/WARM ADVECTION ON THE 295K/300K THETA
SURFACES AHEAD OF THE LOW TAPERS OFF SHORTLY AFTER 12Z. HOWEVER
MODELS INDICATE A DEEP MOIST LAYER MOVING OVERHEAD. THE FAIRLY
BROAD THOUGH WEAK OMEGA AND SOUTHWEST OROGRAPHIC FLOW SHOULD STILL
GENERATE MTN SNOW TODAY WITH AREAS OF SNOW ACROSS SWRN VALLEYS IN
THE UPSLOPE FLOW. FORCING SHOULD ALSO TAP POTENTIAL CONVECTIVE
INSTABILITY FOR SOME HEAVIER EMBEDDED SHOWERS THIS AFTERNOON AS
THE TROUGH AXIS APPROACHES.
THE AREA LOOKS TO BE BETWEEN DISTURBANCES TONIGHT AS THE SRN CA LOW
HEADS TOWARD THE SOUTHERN PLAINS AND THE NEXT DISTURBANCE APPROACHES
FROM THE NORTHWEST. THIS SHORTWAVE ENERGY...CURRENTLY ALONG THE
BRITISH COLUMBIA COAST...WILL DRIVE A COLD FRONT ACROSS NE UT/NW CO
ON TUESDAY SHIFTING WINDS TO MORE WESTERLY AND THE FOCUS OF SNOW TO
THE CENTRAL AND NORTHERN MTNS. MOISTURE CONTENT LIMITED WITH THIS NW
SYSTEM AS MODELS SHOW 700 MB SPECIFIC HUMIDITY UNDER 3 G/KG...BUT
TEMPS LOOK FAVORABLE FOR EFFICIENT DENDRITIC SNOW GROWTH GIVEN GOOD
DYNAMIC AND FRONTAL FORCING. THIS SHOULD DRIVE SNOW DOWN TO VALLEY
FLOORS ACROSS THE CENTRAL AND NORTH. LATER SHIFTS CAN REASSESS THE
POTENTIAL FOR VALLEY HIGHLIGHTS.
CONTINUED WITH THE CURRENT WINTER STORM WARNINGS. ADDED THE
ROAN/TAVAPUTS PLATEAUS (CO ZONE 3) AND THE ELKHEAD/PARK MTNS (CO
ZONE 4) AS WINTER WEATHER ADVISORIES...STARTING AT NOON FOR ZONE 3
AND THIS EVENING FOR ZONE 4. THE ELKHEAD/PARK MTNS SHOULD EXPERIENCE
SOME LIGHT SNOW TODAY BUT BELIEVE THE MORE SIGNIFICANT ACCUMULATIONS
WILL OCCUR TONIGHT/TUESDAY WITH THE NORTHWEST DISTURBANCE. THINKING
5-10 INCHES OF SNOW FOR THESE ADVISORIES.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 356 AM MST MON FEB 3 2014
MODELS ALL SHOW THE NORTHERN SHORTWAVE TROUGH ELONGATING TO THE
WEST AND DROPPING SLOWLY SOUTH OVER MONTANA AND WYOMING...WITH A
COLD FRONT STRETCHING WEST TO EAST ALONG THE CO/WY BORDER AND
THEN PLUNGING SOUTH ALONG THE CO FRONT RANGE. A VORT MAX AND JET
SPEED MAXIMA OFF THE OR COAST TUE NIGHT AND WED MOVES SOUTH OVER
NRN CA AND NRN NV...INDUCING A WAVE OVER NV ALONG THE QUASI-
STATIONARY FRONT. A SURFACE LOW DEVELOPS OVER CENTRAL NEVADA WED
NGT AND THU MORNING. THIS LOW KEEPS WHAT WILL BE A WARM FRONT
NORTH OF THE FORECAST AREA THU AND FRI...THEN AS IT SLIDES SE FRI
AFTERNOON AND FRI NIGHT ITS COLD FRONT AND THE UPPER TROUGH WILL
MOVE THROUGH THE AREA FRI NGT AND SAT.
FOR TUE NIGHT THROUGH SAT THE FORECAST AREA WILL REMAIN BENEATH A
MOIST WESTERLY FLOW PRODUCING PLENTY OF CLOUD COVER AND PERSISTENT
MOUNTAIN PRECIP...AND PERIODS OF VALLEY PRECIP. SAT NGT AND SUN
SHOULD SEE MUCH LESS CLOUD AND PRECIP AS THE STRONG TROUGH MOVES
INTO THE CENTRAL PLAINS AND DRIER RIDGING AND NW FLOW ALOFT TAKE
OVER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1104 AM MST MON FEB 3 2014
AREAS OF LIGHT SNOW WILL PREVAIL THROUGH 18Z TUESDAY AFTERNOON
WITH PERIODIC OR INTERMITTENT LOW CIGS/VIS...ESPECIALLY SKY
COUNTRY AIRPORTS. PASSING BANDS OF SNOW IS EXPECTED FOR THE LOWER
ELEVATED TAF SITES AS WELL. THEIR WILL BE POCKETS OF VFR THROUGH
EARLY AFTERNOON...BUT EXPECT DETERIORATING CONDITIONS AFTER 06Z
WITH SNOW BECOMING WIDESPREAD.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL 11 PM MST TUESDAY COZ010-012.
WINTER STORM WARNING UNTIL 11 PM MST TUESDAY ABOVE 7500 FEET FOR
COZ017.
WINTER STORM WARNING UNTIL 11 PM MST TUESDAY COZ009-013-018-019.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 11 PM MST
TUESDAY COZ004.
WINTER WEATHER ADVISORY UNTIL 11 PM MST TUESDAY ABOVE 7500 FEET
FOR COZ003.
UT...WINTER STORM WARNING UNTIL 11 PM MST TUESDAY ABOVE 7500 FEET FOR
UTZ028.
&&
$$
UPDATE...PF
SHORT TERM...JAD
LONG TERM...CC
AVIATION...PF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1250 PM EST MON FEB 3 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVING ALONG A STALLED FRONT WILL PASS WELL
SOUTH OF NEW ENGLAND TODAY...BRINGING A PERIOD OF LIGHT SNOW
ACROSS THE REGION. A SIGNIFICANT WINTER STORM IS EXPECTED TO
IMPACT SOUTHERN NEW ENGLAND TUESDAY NIGHT INTO WEDNESDAY. BELOW
NORMAL TEMPERATURES THEN PREVAIL THROUGH THE END OF THIS WEEK.
ANOTHER WINTER STORM IS POSSIBLE AROUND NEXT SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1245 PM UPDATE...
STEADY LIGHT SNOW HAS MADE IT A BIT FURTHER N THAN ANTICIPATED
WITH VSBYS DOWN TO A MILE UP TO ROUTE 2. BUT HEAVIER SNOW CONFINED
SOUTH OF THE MASS PIKE. BEST BANDING SIGNATURE ASSOCD WITH THE
MID LEVEL FRONTOGENESIS IS MOSTLY SOUTH OF LONG ISLAND AND WILL
REMAIN TO THE SOUTH...BUT HIGHER REFLECTIVITIES EXTEND NWD INTO
CT/RI AND SE MA WHERE MODERATE SNOW NOTED. LATEST HIRES GUIDANCE
AND HRRR SHOW STEADIEST SNOW THROUGH 21Z THEN TAPERING OFF FROM
WEST TO EAST.
HIRES WRF AND RAP QPF 0.25" CT/RI/MA BORDER TO 0.50" ALONG THE S
COAST WITH AMOUNTS LESS THAN 0.10" ROUTE 2 NWD. ADJUSTED THE 1-2"
AMOUNTS NWD TO MASS PIKE REGION...OTHERWISE NO CHANGES. SLR
CLOSER TO 8-10:1 NEAR THE S COAST WHERE HEAVIER QPF WHICH
SUGGESTS UP TO 4-5" POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT AND TUESDAY...
LOW MOVES OUT TO SEA THIS EVENING. COULD BE SOME LINGERING SNOW
OVER THE CAPE AND ISLANDS...WE WILL CONTINUE WITH POPS IN THIS
AREA DURING THE START OF THE NIGHT. HIGH PRESSURE BUILDS IN
OVERNIGHT AND MOVES OVERHEAD TUESDAY. EXPECT A CLEARING TREND
TONIGHT AND FAIR WEATHER THROUGH TUESDAY. WITH INCREASING HIGH
LEVEL MOISTURE DURING THE AFTERNOON...EXPECT SOME INCREASING HIGH
CLOUDS LATE TUESDAY. TEMPS ALOFT TUESDAY...WHEN MIXED...WILL
SUPPORT MAX TEMPS IN THE 30S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
*/ HIGHLIGHTS...
- WINTER STORM WATCH IN EFFECT FOR TUESDAY NIGHT INTO WEDNESDAY
- BELOW-NORMAL CONDITIONS AND DRY FOR THE LATE WEEK PERIOD
- ANOTHER POSSIBLE WINTER STORM AROUND SUNDAY
*/ OVERVIEW...
CONFLUENCE OF THE SPLIT-FLOW REGIME ACROSS THE NORTHEASTERN CONUS
SEEMINGLY PREVAILS AS RIDGING OVER SIBERIA KEEPS THE POLAR LOW IN
PLAY ACROSS THE NORTH-NORTHEASTERN CANADIAN MARITIMES...AS TROUGHING
IS PREFERRED OVER THE WESTERN CONUS. INDIVIDUAL PACIFIC- AND POLAR-
ORIGIN DISTURBANCES WILL MAKE FOR AN ACTIVE WEATHER PATTERN WITH
STORMS BOTH MONDAY AND WEDNESDAY.
*/ MODEL PREFERENCE...
A CONSENSUS BLEND WAS PREFERRED AS ALL FORECAST GUIDANCE HAS COME
INTO GOOD AGREEMENT CONCERNING THE MILLER-B STORM-TYPE SETUP FOR THE
MIDWEEK PERIOD. AS FOR THE REMAINDER OF THE FORECAST...ENSEMBLE
MEANS WERE GREATLY CONSIDERED ALONG WITH WPC GUIDANCE.
*/ DAY TO DAY DETAILS...
TUESDAY NIGHT INTO WEDNESDAY...
SOUTHERN STREAM DISTURBANCE ELONGATES THROUGH THE CONFLUENCE ACROSS
THE NORTHEASTERN CONUS TO INVOKE A MILLER-B STORM-TYPE SOUTH OF NEW
ENGLAND. WITH CERTAINTY...AS SURFACE LOW PRESSURE WEAKENS ALONG THE
WESTERN APPALACHAINS...IT RENEWS ALONG THE ATLANTIC SHORELINE IN
VICINITY OF THE DELMARVA PENINSULA / SOUTHERN NEW JERSEY COASTLINE
AS AN ATTENDANT H85 CLOSED LOW SWEEPS ACROSS THE NORTHERN OHIO RIVER
VALLEY EAST THROUGH CENTRAL NEW ENGLAND WITH MUCH OF THE ACTIVITY
TAKING PLACE AFTER MIDNIGHT WEDNESDAY TOWARDS WEDNESDAY MIDDAY. THE
WARM-MOIST CONVEYER BELT IS DRAWN NORTH AND EAST TOWARDS THE H85
LOW THE EAST-WEST TRACK OF WHICH IS A ROUGH APPROXIMATION OF
ANTICIPATED THERMAL-PACKING AND DEFORMATION OCCURRING WITH HEIGHT
FURTHER NORTH. MID-LEVEL FRONTOGENETICAL / ISENTROPIC FORCING IS
STRONGEST WITHIN REGIONS OF GREATEST DEFORMATION...AND SUCH
SIGNALS OCCURRING BENEATH THE RRQ OF THE UPPER-LEVEL JET /CENTERED
AROUND 12Z WEDNESDAY/ WILL YIELD STRONG LIFT THROUGH THE DENDRITIC
GROWTH ZONE /COLLOCATED WITH REGIONS OF STEEP H3-7 LAPSE RATES/
RESULTING IN PSEUDO EAST-WEST MESOSCALE SNOW-BANDING ALONG WITH
THE POTENTIAL FOR 1-2 INCH PER HOUR SNOWFALL RATES. WHILE COLD-AIR
DAMMING IS LIKELY TO PROCEED DURING THE AFOREMENTIONED LOW
PRESSURE TRANSITION...THE DRAINAGE FLOW IS NOT FROM ARCTIC SOURCE
REGIONS. THUS ANTICIPATING SNOW-TO- LIQUID RATIOS OF AROUND 1:10
TO 1:15 DEPENDING ON SURFACE TEMPS /LESS OF A FLUFFY SNOW AND MORE
OF A WET SNOW/.
YET WITH WOBBLES AMONG THE FORECAST GUIDANCE CONCERNING THE TRACK
AND POSITIONING OF THE LOW THERE IS UNCERTAINTY CONCERNING SURFACE
AND LOW-LEVEL TEMP PROFILES /THICKNESSES/ AND WHERE SPECIFICALLY
BOTH THE HEAVIEST SNOW AND GREATEST IMPACTS WILL OCCUR. WHILE THE
BROAD-SCALE PATTERN IS APPARENT THE DIFFICULTY IN THE FORECAST IS
IRONING OUT THE SMALL DETAILS.
GETTING A FEEL FOR POTENTIAL OUTCOMES...TOP 5 CIPS ANALOGS BASED OFF
THE 03.0Z GFS EXHIBIT AN EAST-WEST SWATH OF 8 TO 12 INCHES OF SNOW
WITH ISOLATED POCKETS OF 12+ CENTERED AROUND THE MA-VT-NH BORDER
/CONSIDERING THOSE ANALOGS WITH AN H85 CLOSED LOW AND SIMILAR
SURFACE LOW PRESSURE PATTERN/. YET EVEN THE VARIETY OF OBSERVED
SNOWFALLS EXHIBITS THE INHERENT UNCERTAINTY IN EXACT OUTCOMES. SREF
MEANS SHOWING HIGH PROBABILITIES FOR 1-INCH PER HOUR SNOWFALL RATES
AS WELL AS GREATEST SNOW ACCUMULATIONS EXCEEDING WINTER WEATHER
WARNING CRITERIA FOR AREAS AROUND THE MA-NH-VT BORDER WITH THE
POTENTIAL FOR ICING TO THE SOUTH. BUT ALSO DECIPHERED FROM THE SREF
IS THE DIFFICULTY IN DISCERNING THE TRANSITION ZONE AS EMPHASIZED BY
THE LOWERED PROBABILITIES AROUND THE MA-CT-RI BORDER REGION FOR ALL
WINTER WEATHER POSSIBILITIES.
SO WITH THE FORECAST...HAVE WEIGHED SURFACE TEMPERATURES TOWARDS THE
WET-BULB WITH EQUAL CONSIDERATION TOWARDS TEMPERATURE AND DEWPOINT.
TAKING A CONSENSUS BLEND WHICH WEIGHS MORE TOWARDS THE NON-ECMWF
SOLUTIONS...ANTICIPATING ALL PRECIPITATION TO START OFF AS SNOW
TOWARDS MIDNIGHT WEDNESDAY. WILL SEE A GRADUAL TRANSITION NORTH OF A
WINTRY MIX /SNOW-SLEET-FREEZING RAIN/ FROM THE SHORELINE DURING THE
EARLY MORNING HOURS...TO ROUGHLY THE MASS-PIKE BY MIDDAY. FROM THE
MORNING INTO MIDDAY...SHOULD SEE A TRANSITION TO RAIN FOR THE
SOUTHERN HALF OF RHODE ISLAND...AND SOUTHERN-TIER OF BRISTOL AND
PLYMOUTH COUNTY MA AND POINTS SOUTH AND EAST.
SUBSEQUENTLY HAVE AN EAST-TO-WEST SWATH OF HEAVY SNOW MAINLY NORTH
OF THE I-84 TO I-90 CORRIDOR WITH THE POTENTIAL OF A WINTRY MIX TO
THE AROUND AND TO THE SOUTH THAT MAY SEE AROUND 8 TO 10 INCHES...
PERHAPS LOCALLY HIGHER AMOUNTS. LESSER AMOUNTS TO THE SOUTH AND EAST
BUT THERE IS A CHANCE FOR ICING ON THE ORDER OF A TENTH OR TWO WITH
THIS FORECAST. WITH THE HIGH CONFIDENCE OF STORM IMPACTS AND THE
POTENTIALS NOTED ABOVE WE HAVE ISSUED A WINTER STORM WATCH FOR ALL
AREAS EXCEPT CAPE COD AND THE ISLANDS /INCLUDING BLOCK ISLAND/.
PLEASE SEE THE COASTAL DISCUSSION BELOW FOR DETAILS CONCERNING
POTENTIAL COASTAL HAZARDS.
WEDNESDAY NIGHT THROUGH THE END OF THE WEEK...
SOME LIGHT SNOW LINGERS TO THE REAR OF THE DEPARTING STORM SYSTEM.
OTHERWISE WEST-NORTHWEST FLOW ADVECTS ARCTIC AIR ACROSS THE REGION.
ANTICIPATE BELOW-NORMAL CONDITIONS.
NEXT WEEKEND AND BEYOND...
CONTINUED VARIABILITY AMONG ENSEMBLE MEMBERS IN HANDLING ENERGY
THROUGH THE LONGWAVE PATTERN. GREAT DISCREPANCIES APPARENT WITH
REGARDS TO A STRONG AREA OF LOW PRESSURE DEVELOPING IN THE GULF OF
ALASKA...AND WHETHER AN AREA OF LOW PRESSURE WILL DEVELOP OUT OF THE
GULF OF MEXICO AND LIFT NORTHEASTWARD TOWARDS NEW ENGLAND SUNDAY
INTO MONDAY. THE MEAN OF ENSEMBLE MEMBERS LEANS IN THE DIRECTION OF
THE AFOREMENTIONED PATTERN...BUT WITH THE WIDE DISPLACEMENT AND
DISPARITY BETWEEN DETERMINISTIC AND ENSEMBLE MEANS...HAVE LITTLE TO
NO CONFIDENCE IN THE FORECAST.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY NIGHT/...
HIGH CONFIDENCE THROUGH TUESDAY.
WIDESPREAD IFR/LIFR CONDITIONS IN SNOW THIS AFTERNOON ALONG AND
SOUTH OF THE MASS PIKE WITH VFR/MVFR TO THE N. CONDITIONS WILL
GRADUALLY IMPROVE TO VFR FROM WEST TO EAST LATER TODAY THROUGH
THIS EVENING...WITH CLEARING SKIES OVERNIGHT. SNOW COVERED
RUNWAYS EXPECTED ALONG AND ESPECIALLY SOUTH OF THE MASS PIKE
THROUGH THIS AFTERNOON.
TUE...VFR WITH LIGHT WINDS. INCREASING MID/HIGH CLOUDS IN THE
AFTERNOON.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS. LOWER CONFIDENCE IN
EXACT TIMING OF IMPROVING CONDITIONS.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS. LOWER CONFIDENCE IN
EXACT TIMING OF IMPROVING CONDITIONS.
OUTLOOK FOR TUESDAY NIGHT INTO FRIDAY NIGHT...
TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.
CONDITIONS DETERIORATE BEGINNING AROUND MIDNIGHT. IFR-VLIFR WITH
+SN. WINTRY MIX /SLEET AND FZRA/ POSSIBLE FOR TERMINALS AROUND
THE MA-CT-RI BORDER WITH A TRANSITION TO RAIN FOR SOUTH-COASTAL
TERMINALS. BY MIDDAY ACTIVITY SWINGS OUT WHILE TRANSITIONING BACK
TO SNOW FOR THOSE TERMINALS OTHERWISE. INCREASING E/NE FLOW
STRONGEST ALONG THE E/SE SHORE.
WEDNESDAY NIGHT INTO FRIDAY NIGHT...HIGH CONFIDENCE.
IMPROVING VFR. -SN LINGERS INITIALLY FOR SOUTHEAST TERMINALS WITH
POTENTIAL IFR IMPACTS. OTHERWISE CIGS/VSBYS LIFTING. BRISK W/NW
WINDS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY NIGHT/...MODERATE CONFIDENCE.
TODAY...LOW PRESSURE PASSES WELL OFFSHORE TO THE SOUTH. THIS WILL
BRING NORTH-NORTHEAST WINDS TO OUR COASTAL WATERS...BUT THE
STRONGER WINDS WILL BE WELL TO THE SOUTH. EXPECT WINDS TO REMAIN
AT OR BELOW 20 KNOTS. EXPECT SEAS TO REMAIN BELOW 5
FEET...ALTHOUGH IT MAY BE CLOSE ON THE OUTER EDGES OF THE OUTER
WATERS. PRECIPITATION MOVES ACROSS THE WATERS...ESPECIALLY THE
WATERS SOUTH OF BOSTON. POTENTIAL FOR VSBYS REDUCED TO 1-2 MILES
IN RAIN AND SNOW ALONG THE SOUTH COASTS OF RI AND MASS.
TONIGHT AND TUESDAY...WINDS SHIFT TO NORTH TONIGHT AND POSSIBLY
NORTHWEST ON TUESDAY. SPEEDS SHOULD REMAIN BELOW 20 KNOTS. SEAS
WILL ALSO REMAIN BELOW 5 FEET. ANY RAIN AND SNOW WILL MOVE OUT TO
SEA EARLY TONIGHT. HIGH PRESSURE BUILDS OVERHEAD ON TUESDAY WITH
FAIR WEATHER.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.
SNOW INITIALLY AFTER MIDNIGHT TRANSITIONING TO A WINTRY MIX BY
MORNING TO PLAIN RAIN BY AFTERNOON FOR THE SOUTH-SOUTHEAST WATERS.
SHOULD REMAIN A SNOW TO WINTRY MIX FOR THE EASTERN WATERS. BRISK
E/NE WINDS WITH GUSTS UP TO 30 KTS TURNING N LATE. INCREASING WAVE
HEIGHTS OVER ALL WATERS. LOW CONFIDENCE ON GALES.
WEDNESDAY NIGHT INTO FRIDAY...HIGH CONFIDENCE.
WINDS AND SEAS DIMINISHING. W/NW FLOW BRISK AT TIMES AND COLDER AIR
BUILDING OVER THE WATERS ALONG WITH WAVE ACTION WILL PRESENT A SMALL
THREAT FOR FREEZING SPRAY.
&&
.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES WILL REMAIN RELATIVELY HIGH TODAY. THERE IS
THE POSSIBILITY FOR SOME SPLASHOVER DURING THE AFTERNOON HIGH TIDE
ALONG PORTIONS OF THE SOUTH SHORE. WINDS ARE NOT EXPECTED TO BE
VERY STRONG...SO SURGE VALUES OF LESS THAN 1 FOOT ARE EXPECTED.
WITH THE TUESDAY NIGHT INTO WEDNESDAY STORM...EASTERLY FLOW WILL
INCREASE WITH GUSTS UP TO 30 KTS. HIGH TIDES WILL BE LOWER THAN
ASTRONOMICAL PEAK PRESENTLY ONGOING. SURGE VALUES UP TO AROUND 1
FOOT ARE POSSIBLE FOR THE EAST SHORES. CONSIDERING ALL FACTORS
THERE IS THE POSSIBILITY OF SPLASHOVER ALONG EAST-FACING SHORES
THOUGH CONFIDENCE IS LOW AT THIS TIME.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
AFTERNOON FOR CTZ002>004.
MA...WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
AFTERNOON FOR MAZ002>021-026.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
MAZ020>022.
NH...WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
AFTERNOON FOR NHZ011-012-015.
RI...WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
AFTERNOON FOR RIZ001>007.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
RIZ003>007.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...KJC
SHORT TERM...WTB
LONG TERM...SIPPRELL
AVIATION...KJC/SIPPRELL
MARINE...WTB/SIPPRELL
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS DES MOINES IA
319 PM CST MON FEB 3 2014
.SHORT TERM /TONIGHT/...
ISSUED AT 316 PM CST MON FEB 3 2014
CONDITIONS WILL REMAIN QUIET AND SEASONABLY WARM THROUGH THE EVENING
HOURS AS SURFACE HIGH PRESSURE SHIFTS OFF TO THE EAST INTO NORTHERN
ILLINOIS. A ZONALLY ORIENTED RIDGE EXTENDING FROM THE CANADIAN
ROCKIES INTO MINNESOTA WILL STRENGTHEN DURING THE OVERNIGHT HOURS
AND CAUSE WINDS TO BACK TO THE EAST BY 12Z TUESDAY AS THE COL
BETWEEN THESE TWO HIGHS TRANSECTS THE STATE. THESE EASTERLY WINDS
WILL HELP MAINTAIN A WEDGE OF DRY AIR BELOW 800 MB THROUGH THE
OVERNIGHT HOURS AS REFLECTED IN THE 12Z/18Z NAM AND 18Z RAP BUFR
SOUNDINGS FOR ALMOST ALL OF THE CWA.
THE LATEST SYNOPTIC GUIDANCE HAS ALSO SLOWED THE ARRIVAL OF OUR NEXT
WINTER STORM TOMORROW MORNING BY ABOUT 4-6 HOURS...WHICH ISN`T
SURPRISING GIVEN THE AMPLITUDE OF THE UPPER LEVEL LONGWAVE TROUGH AS
IT MOVED INLAND OVER CALIFORNIA LAST NIGHT. THE 300 MB WAVE WILL
EJECT OUT OF THE FOUR CORNERS REGION AFTER 06Z AND BECOME NEGATIVELY
TILTED...BUT DISJOINTED FROM THE MAIN UPPER LEVEL TROUGH...AS IT
REACHES THE TEXAS PANHANDLE AT 12Z. VISIBLE SATELLITE IMAGERY SHOWS
MOISTURE ALREADY POOLING OVER WESTERN KANSAS AND NEBRASKA OUT
AHEAD OF THE WAVE...WHICH WILL SPREAD EASTWARD INTO THE CWA AFTER
06Z.
PREVIOUS MODEL RUNS HAD A BAND OF LIGHT SNOW LIFTING NORTH AND EAST
ACROSS THE CWA OVERNIGHT IN CONJUNCTION WITH A RIBBON OF 800-850
MB FRONTOGENESIS OUT AHEAD OF THE MAIN STORM. THE NAM IN
PARTICULAR HAS GREATLY BACKED OFF ON THE OVERNIGHT QPF...MOSTLY
DUE TO THE PRESENCE OF THE AFOREMENTIONED LOW LEVEL DRY LAYER. IN
FACT...THE QPF THAT IS BEING GENERATED BY THE NAM MAY JUST BE AN
ARTIFACT OF PREVIOUS MODEL RUNS AND COULD VANISH BY THE 00Z RUN.
THE GFS 280K ANALYSIS ALSO AGREES WITH THIS THINKING. DESPITE
SHARP ASCENT FROM 880 TO 800 MB OVER THE SOUTHWEST CWA...MOISTURE
REMAINS LIMITED WITH CDEFS RANGING ANYWHERE FROM 50 TO 150 MB.
THUS...THE FORECAST CHALLENGE FOR THE OVERNIGHT PERIOD REVOLVED
AROUND WHETHER THE LOW LEVEL DRY AIR WILL WIN OUT OVER THE
OVERRUNNING MOISTURE PLUME. HAVE TRENDED TOWARDS THE NAM IN BACKING
OFF ON POPS SUBSTANTIALLY...AND THIS TREND WILL NEED TO BE MONITORED
DURING THE OVERNIGHT HOURS.
.LONG TERM /TUESDAY THROUGH MONDAY/...
ISSUED AT 316 PM CST MON FEB 3 2014
THE WINTER STORM FOR TUESDAY AND TUESDAY NIGHT IS AN INTERESTING
STORM ON MANY LEVELS. IT WILL BRING WITH IT SEVERAL ELEMENTS OF A
WINTER STORM...SNOW THEN WIND FOLLOWED BY BITER COLD. LIGHT SNOW
WILL BE ONGOING FROM A WEAK WAVE THAT COMES THROUGH TONIGHT. THERE
ARE SOME QUESTIONS REMAINING FOR TUESDAY MORNING AS TO HOW QUICKLY
WE CAN SATURATE THE ATMOSPHERE AND HOW FAR SOUTH THAT WILL OCCUR.
THERE IS ALSO UNIMPRESSIVE FORCING IN THE DENDRITIC LAYER THROUGH
18Z OVER ALL BUT THE FAR SOUTHERN FORECAST AREA.
BY TUESDAY AFTERNOON INTO THE EVENING HOWEVER A SHORTWAVE LIFTS OUT
OF THE SOUTHERN PLAINS AND INTO THE UPPER MIDWEST...NEAR THE IOWA
MISSOURI BORDER. THE ATMOSPHERE WILL QUICKLY SATURATE IN THE
AFTERNOON WHILE DECENT FORCING LIFTS ACROSS THE SOUTHERN PORTION OF
THE FORECAST AREA. AFTER SOME LIGHT SNOW EARLY IN THE MORNING
FOLLOWED BY A BIT OF A BREAK...SNOW SHOULD BEGIN AGAIN IN THE
AFTERNOON AND BECOME MODERATE AT TIMES... ESPECIALLY AFTER 3 PM.
ONE CONCERN IS THAT MOST OF THE FORCING THAT OCCURS HAPPENS ABOVE
THE DENDRITIC LAYER AND WE STILL HAVE SOME ISSUES WITH SATURATION AT
18Z. BY 21Z THOUGH WE SATURATE TO AT LEAST 700 MB AND SOME FORCING
DOES MAKE IT DOWN INTO THE DENDRITIC LAYER RESULTING IN A PERIOD OF
MODERATE SNOWFALL ACROSS SOUTHERN IOWA. THE BEST AREA TO SEE THIS
IS THE SOUTHERN TWO TIERS OF COUNTIES. AS YOU GO TOWARDS THE I-80
CORRIDOR THE FORCING IS NOT AS GOOD FOR AS LONG A PERIOD OF TIME
BUT SUFFICIENT FOR SEVERAL INCHES OF SNOW.
AS COLDER AIR WORKS INTO THE AREA SNOWFALL RATIOS WILL MOVE FROM
ABOUT 14 TO 1 CLOSER TO 18 OR 19 TO 1. THIS WILL HELP GIVE HIGHER
SNOWFALL TOTALS AND THE SNOW SHOULD BE FLUFFY AND EASILY BLOWN
AROUND.
THIS SYSTEM WILL ALSO HAVE WIND WITH IT BUT AGAIN THE WIND WILL NOT
BE EXTREMELY STRONG NOR WILL IT BE COINCIDENT WITH THE BEST
SNOWFALL. SO WHILE NOT A PERFECT SITUATION IT SHOULD STILL BE
SUFFICIENT TO PRODUCE DANGEROUS TRAVEL... ESPECIALLY FAR SOUTH. UP
TOWARDS THE I-80 CORRIDOR CONDITIONS ARE STILL GOOD BUT NOT AS GOOD
AS FURTHER SOUTH. WINDS WILL INCREASE BETWEEN 4 AND 6 PM AND BY
THAT TIME THERE SHOULD BE 2 TO 3 INCHES ON THE GROUND. SINCE TRAVEL
IMPACTS FROM THIS SYSTEM ARE POTENTIALLY DANGEROUS AS IT WILL HAPPEN
DURING THE EVENING COMMUTE I HAVE PUT THE WINTER STORM WARNING UP TO
THE I-80 CORRIDOR. WE WILL CONTINUE TO EVALUATE TO SEE IF SNOWFALL
AMOUNTS PAN OUT BUT AT THIS POINT IN TIME CONFIDENCE IS HIGH FOR
SEVERAL INCHES OF SNOW ALONG WITH INCREASING WIND DURING THE DRIVE
HOME WARRANTING THE WINTER STORM WARNING.
LOCATIONS FURTHER NORTH WILL SEE LESS SNOWFALL BUT WILL STILL SEE
BRISK WINDS AND COLD TEMPS. IN FACT WE WILL LIKELY BE DEALING WITH
WIND CHILL ISSUES BEYOND THE WINTER STORM. I HAVE ISSUED A WINTER
WEATHER ADVISORY FOR LOCATIONS BETWEEN HIGHWAY 20 AND HIGHWAY 30.
THESE AREAS WILL GENERALLY SEE BETWEEN 2 AND 4 INCHES OF SNOW AND
COMBINED WITH SOME WIND I WOULD EXPECT TO SEE AT LEAST SOME TRAVEL
ISSUES ESPECIALLY IN OPEN AREAS LATER IN THE AFTERNOON AND EVENING.
BEYOND TUESDAY...MID WEEK WILL BE BITTER COLD WITH SUB ZERO LOWS AND
SINGLE DIGIT HIGHS. BY FRIDAY A STORM SYSTEM TAKING SHAPE OVER THE
SOUTHWEST WILL PRODUCE A MORE ZONAL FLOW ACROSS THE MIDWEST AND
TEMPERATURES...WHILE STILL COLD...WILL MODERATE INTO THE TEENS.
NONE OF THE MODELS NOW MATURE THIS INTO A CLOSED LOW BUT THEY STILL
VARY ON THE INTENSITY OF THE WAVE AND THUS TIMING ISSUES ARISE AS
THE MORE DIGGING THAT OCCURS THE SLOWER THE WAVE LIFTS OUT. THE GFS
IS STILL THE MOST BULLISH IN BRINGING PRECIP THIS FAR NORTH WHILE
THE EURO KEEP IT FURTHER SOUTH. FOR NOW I KEEP THE CHANCE POPS GOING
FOR THE START OF THE WEEKEND.
&&
.AVIATION...03/18Z
ISSUED AT 1139 AM CST MON FEB 3 2014
VFR CONDITIONS WILL PREVAIL THROUGH THE AFTERNOON AND EVENING
HOURS WITH CEILINGS GRADUALLY LOWERING TO LOW VFR LEVELS TOWARDS
SUNRISE TOMORROW. STORM SYSTEM OUT TO THE WEST HAS SLOWED AND WILL
BE WORKING AGAINST DRY AIR NEAR THE SURFACE...SO HAVE IMPROVED THE
TAF FORECASTS FOR TUE MORNING WITH CONFIDENCE OF ANY SIGNIFICANT
RESTRICTIONS LOW. STILL EXPECT LIGHT SNOW TO OVERSPREAD THE WEST
AFTER 09Z THAT COULD LEAD TO MVFR CEILINGS AND VSBYS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM NOON TUESDAY TO 6 AM CST WEDNESDAY FOR
ADAIR-CASS-DALLAS-GUTHRIE-JASPER-MADISON-MAHASKA-MARION-POLK-
POWESHIEK-WARREN.
WINTER WEATHER ADVISORY FROM NOON TUESDAY TO 6 AM CST WEDNESDAY
FOR AUDUBON-BLACK HAWK-BOONE-CALHOUN-CARROLL-CRAWFORD-GREENE-
GRUNDY-HAMILTON-HARDIN-MARSHALL-SAC-STORY-TAMA-WEBSTER.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 6 AM CST WEDNESDAY FOR
ADAMS-APPANOOSE-CLARKE-DAVIS-DECATUR-LUCAS-MONROE-RINGGOLD-
TAYLOR-UNION-WAPELLO-WAYNE.
&&
$$
SHORT TERM...SKOW
LONG TERM...FAB
AVIATION...SKOW
AREA FORECAST DISCUSSION
NWS GOODLAND KS
121 PM MST MON FEB 3 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 121 PM MST MON FEB 3 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW POSITIVELY TITLED TROUGH
JUST EAST OF THE FOUR CORNERS REGION WITH SW FLOW ADVECTING PLUME OF
MOISTURE AHEAD OF THIS TROUGH FROM THE PACIFIC INTO THE SOUTHERN AND
CENTRAL PLAINS. AT THE SURFACE A FRONT IS CURRENTLY STALLED OVER
NORTHERN NEBRASKA WITH AN ARCTIC FRONT ALONG THE CANADIAN US BORDER.
WINTER STORM ON TRACK TO IMPACT OUR CWA TONIGHT THROUGH TUESDAY WITH
HEAVY SNOW AND BLOWING SNOW. WINTER STORM WARNING WAS ISSUED EARLIER
FOR SW PART OF THE CWA...AND WINTER WEATHER ADVISORY FOR THE REST OF
THE CWA.
TONIGHT-TUESDAY...AS TROUGH OVER WESTERN US ROUNDS THE BASE ON THE
ROCKIES IT WILL BECOME NEGATIVELY TILTED WITH TWO COLD FRONTS
DROPPING SOUTH. THE FIRST WILL PASS THROUGH THE CWA AFTER MIDNIGHT
WITH AN ARCTIC FRONT DROPPING SOUTH THROUGH THE DAY TUESDAY.
INITIALLY SNOW DEVELOPMENT WILL BE TIED TO LOBE OF MID LEVEL
FRONTOGENETICAL FORCING OVER SW COLORADO...WHICH WILL SHIFT NORTH AS
TROUGH MOVES EAST AND THEN NORTH OVER KANSAS. GUIDANCE STILL SHOWS
INSTABILITY IN THE SATURATED LAYER IN SNOW BAND THAT FORMS OVER
COLORADO...WHICH COULD SUPPORT MUCH HIGHER SNOW RATES ACROSS THE SW
PART OF OUR CWA. A CLOSED H7 LOW WILL FORM OVER KANSAS AS THE TROUGH
DEEPENS. THERE CONTINUES TO BE AN INDICATION OF A DEFORMATION BAND
FORMING ALONG THIS 700MB LOW...WITH DIFFERENCES IN ORIENTATION. THIS
DEFORMATION BAND WOULD BE THE MAIN SNOW PRODUCER FOR EASTERN
LOCATIONS...WITH LIGHT SNOW FILLING IN BETWEEN THESE FEATURES. THE
INITIAL BAND OVER COLORADO SHOULD WEAKEN AS BEST UPPER LEVEL SUPPORT
SHIFTS EAST...WITH A WEST-EAST ORIENTATED AREA OF SNOW OVERSPREADING
THE REST OF THE FORECAST AREA. THOUGH MOST GUIDANCE INDICATES A
WEAKENING TREND...WE WILL NEED TO MONITOR TO SEE IF THE INITIAL
CONVECTIVE BAND IN SW COLORADO MAINTAINS ITS INTENSITY AS IT MOVES
NORTH (CURRENTLY INDICATED BY 12Z NAM). IF THIS WERE TO OCCUR WE
WOULD SEE WARNING CRITERIA FURTHER NORTH IN THE CWA. AS IT STANDS
MOST LOCATIONS ALONG THE I-70 CORRIDOR SHOULD SEE 3-5 INCHES WITH
AROUND 3 INCHES IN THE FAR NORTH. CURRENT THOUGHTS ARE LOCATIONS
IMPACTED BY THE CONVECTIVE BAND TONIGHT AND TUESDAY WOULD SEE 6-8
INCHES TOTAL...AND THIS IS WHERE WARNING HAS BEEN ISSUED.
IN ADDITION TO SNOW...BLOWING SNOW SHOULD DEVELOP DURING THE DAY
TUESDAY AS WINDS INCREASE DURING THE DAY. WE MAY NOT SEE THE HIGHEST
WINDS MIX TO THE SURFACE BUT WE SHOULD STILL BE ABLE TO SEE SOME
AFTERNOON GUSTS IN THE 30-35 MPH. THIS SHOULD BE ENOUGH TO PRODUCE
AREAS OF BLOWING SNOW...MAINLY IN THE EAST...THOUGH WE COULD SEE
REDUCED VISIBILITIES JUST ABOUT EVERYWHERE IN THE CWA WITH AT LEAST
PATCHY BLOWING SNOW EXPECTED.
.LONG TERM...(TOMORROW NIGHT THROUGH NEXT MONDAY)
ISSUED AT 1216 PM MST MON FEB 3 2014
LIGHT SNOW WILL BE WINDING DOWN TUESDAY NIGHT...ANY ADDITIONAL
ACCUMULATIONS WILL BE AN INCH OR LESS. WINDS WILL ALSO BE
GRADUALLY DIMINISHING...BUT THERE WILL BE AREAS OF BLOWING SNOW
ESPECIALLY IN THE EVENING. AS THE SNOW ENDS ATTENTION WILL TURN TO
TEMPERATURES. THE PERIOD WEDNESDAY THROUGH FRIDAY WILL BE
BRUTAL...ONE OF THE COLDEST STRETCHES IN RECENT MEMORY. WIND
CHILL WARNINGS OR ADVISORIES WILL LIKELY BE REQUIRED EVERY DAY.
SOME LOW TEMPERATURE RECORDS COULD BE SET...ESPECIALLY THURSDAY
MORNING AS THE SURFACE RIDGE SETTLES OVER THE REGION AND SKIES
CLEAR...TEMPERATURES WILL PLUMMET TO AROUND 15 BELOW. HIGH
TEMPERATURES ON WEDNESDAY AND THURSDAY WILL STRUGGLE TO GET ABOVE
ZERO. SOME ADDITIONAL LIGHT SNOW OR FLURRIES WILL BE POSSIBLE AS A
SERIES OF WEAK DISTURBANCE ROTATE ACROSS THE CENTRAL ROCKIES. THE
MOST SIGNIFICANT SYSTEM FRIDAY NIGHT AND SATURDAY COULD PRODUCE
ANOTHER 2 TO 4 INCHES. FINALLY START TO SEE SOME RIDGING ALOFT
BEHIND THAT SYSTEM AT THE END OF THE PERIOD...POSSIBLY GETTING
ABOVE FREEZING NEXT MONDAY FOR THE FIRST TIME IN QUITE AWHILE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1016 AM MST MON FEB 3 2014
AT KGLD...IFR CONDITIONS DUE TO LOW CIGS WILL CONTINUE TO EXPAND
THROUGH THIS AFTERNOON AND EVENTUALLY BECOME PREVALENT AND LOWER.
DURING THE EVENING HOURS...CIGS MAY LOWER TO VLIFR AS WELL AS
POSSIBLE VIS REDUCTIONS IN PATCHY FOG. OVERNIGHT...SNOW WILL
DEVELOP FROM NORTH TO SOUTH WITH VLIFR EXPECTED BY DAYBREAK
TUESDAY MORNING. BLOWING SNOW WILL BECOME A CONCERN BY MID TUESDAY
MORNING WITH INCREASING NORTHEASTERLY WINDS.
AT KMCK...MID CLOUD DECK WILL SLOWLY LOWER TO MVFR BY THIS
AFTERNOON AND IFR TONIGHT. PATCHY FOG TONIGHT MAY RESULT IN
VISIBILITY RESTRICTIONS. AS SNOW BEGINS AROUND DAYBREAK TUESDAY
MORNING VLIFR CONDITIONS EXPECTED TO DEVELOP WITH LOW CIGS AND
VISIBILITY RESTRICTIONS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY FROM 11 PM MST /MIDNIGHT CST/ THIS
EVENING TO 5 PM MST /6 PM CST/ TUESDAY FOR KSZ001>004-
013>016-028-029.
WINTER STORM WARNING FROM 8 PM MST /9 PM CST/ THIS EVENING TO 5
PM MST /6 PM CST/ TUESDAY FOR KSZ027-041-042.
CO...WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 5 PM MST
TUESDAY FOR COZ090-091.
WINTER STORM WARNING FROM 8 PM THIS EVENING TO 5 PM MST TUESDAY
FOR COZ092.
NE...WINTER WEATHER ADVISORY FROM 11 PM MST /MIDNIGHT CST/ THIS
EVENING TO 5 PM MST /6 PM CST/ TUESDAY FOR NEZ079>081.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...024
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1242 PM EST MON FEB 3 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EST MON FEB 3 2014
WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL NRN STREAM
MID/UPPER LEVEL FLOW THROUGH THE NRN GREAT LAKES AS A SHORTWAVE
TROUGH MOVES TO THE NORTH THROUGH NRN ONTARIO. AT THE SFC...A WEAK
GRADIENT AND LIGHT WINDS PREVAILED AS AN AREA OF ARCTIC HIGH PRES
BUILDS TOWARD THE SRN GREAT LAKES. THIS HAS ALLOWED TEMPS TO DROP
OFF INTO THE -10 TO -23 RANGE OVER INLAND PORTIONS OF WRN UPPER MI.
TEMPS HAVE RISEN QUICKLY TO AROUND ZERO OVER N CNTRL UPPER MI AS AN AREA
OF LOW CLOUDS MOVES THROUGH.
TODAY AND TONIGHT...SATELLITE TRENDS AND MODELS 900-850 MB RH FCST
SUGGEST THAT THE CLOUDS WILL DEPART THE CWA BY 12Z LEAVING MOSTLY
SUNNY SKIES FOR MUCH OF THE MORNING. CLOUDS SHOULD THEN INCREASE
AGAIN IN THE AFTERNOON AHEAD OF A SFC-850 MB TROUGH MOVING FROM MN
TOWARD UPPER MI. TEMPS SHOULD REBOUND INTO THE UPPER TEENS TO AROUND
20. THERE MAY ALSO BE SLIGHT CHANCE FOR SOME LIGHT SNOW SHOWERS OVER
CNTRL UPPER MI AS AN AREA OF 270K-275K ISENTROPIC LIFT (900-800 MB)
MOVES THROUGH THE AREA BTWN 21Z-03Z. OTHERWISE...THE EXTENSIVE ICE
COVER ON LAKE SUPERIOR WILL MINIMIZE THE POTENTIAL FOR ANY LES AS THE
LOW LEVEL WINDS VEER TO THE NW AND 850 MB TEMPS DROP INTO THE -15C TO
-18C RANGE OVERNIGHT. LINGERING LOW CLOUDS WILL KEEP TEMPS FROM
DROPPING OFF TOO FAR AS MIN READINGS FALL TO AROUND ZERO.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 419 AM EST MON FEB 3 2014
BENIGN WEATHER PATTER IS EXPECTED FROM TUE THROUGH SUN AS FLOW IS
MOSTLY ZONAL AND EXTENT OF ICE COVER ON LAKE SUPERIOR LIMITS LES
COVERAGE/CHANCES.
REALLY...NOT TOO OPTIMISTIC ON PRECIP CHANCES IN ANY PART OF THE
LONG TERM FORECAST PERIOD...WITH JUST LOW 30 POPS BEING THE HIGHEST
POP IN THE LONG TERM. TEMPS ARE EXPECTED TO CONTINUE TO BE BELOW
NORMAL WITH HIGHS GENERALLY IN THE UPPER POSITIVE SINGLE DIGITS TO
TEENS. THU LOOKS TO BE THE COLDEST DAY WITH HIGHS FROM THE LOW
POSITIVE SINGLE DIGITS W TO THE LOW TEENS E. MAIN CHANGE TO PREVIOUS
FORECAST WAS TO ADD SOME BLOW SNOW TO THE KEWEENAW PENINSULA THU AND
FRI. W-WSW WINDS LOOK TO GUST TO AROUND 25KTS AT THAT TIME...AND
WITH ICE COVERING MOST OF LAKE SUPERIOR...THE KEWEENAW IS ESPECIALLY
EXPOSED TO BLOWING SNOW. USED CONSENSUS OF GUIDANCE FOR THE LONG
TERM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1242 PM EST MON FEB 3 2014
VFR CONDITIONS WILL PREVAIL TO START THE PERIOD...BUT AN
APPROACHING TROUGH WILL LEAD TO INCREASING CLOUDS AND LOWERING
CEILINGS THROUGH THE EVENING HOURS. THE QUESTION IS HOW LOW THEY
WILL GO. LOOKING UPSTREAM IN NORTHWEST MINNESOTA...SOUTHERN
MANITOBA...AND NORTH DAKOTA...MOST SITES ARE AT VFR WITH AN
OCCASIONAL HIGH END MVFR WITH A SNOW SHOWER. THUS...HAVE FOLLOWED
THAT IDEA FOR MOST OF THE TAF SITES ALONG AND BEHIND THE TROUGH THIS
EVENING INTO TUESDAY MORNING. WILL MENTION -SHSN FOR KIWD/KCMX DUE
TO THE LIGHT UPSLOPE FLOW WHICH MAY BE ENOUGH TO KICK OFF A FEW SNOW
SHOWERS OR FLURRIES. SINCE MUCH OF THE WESTERN LAKE IS ICE
COVERED...HELD OFF ON VISIBILITY RESTRICTIONS DUE TO THE LIMITED
INFLUENCE OF THE LAKE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EST MON FEB 3 2014
QUIET PERIOD OF WEATHER EXPECTED FOR LAKE SUPERIOR THIS WEEK. GALES
ARE NOT EXPECTED. SOME OCCASIONAL FREEZING SPRAY WILL STILL BE POSSIBLE
OVER THE OPEN WATERS OF EASTERN LK SUPERIOR. LATEST SATELLITE
IMAGERY INDICATES EXTENSIVE ICE COVER ON THE LAKE CONTINUES TO
EXPAND...EVEN OVER EASTERN PORTIONS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...SRF
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
302 PM CST MON FEB 3 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 302 PM CST MON FEB 3 2014
THE MAIN CHALLENGE WITH THIS FORECAST IS CLOUD COVER SINCE THE
MODELS ARE NOT HANDLING IT WELL...AND ITS IMPLICATIONS ON
TEMPERATURES TONIGHT. I LEANED ON THE CLOUDIER SIDE THROUGH EARLY
THIS EVENING SINCE THE OVERCAST SKIES ACROSS NORTHERN MINNESOTA
AND UPSTREAM IN CANADA APPEAR TO BE HANGING ON. HOWEVER...I THINK
THERE WILL BE A GRADUAL PARTIAL CLEARING TREND LATER TONIGHT DUE
TO THE SURFACE HIGH PRESSURE THAT WILL BE MOVING INTO THE
NORTHLAND TONIGHT. IF THE PARTIAL CLEARING PANS OUT...THEN THE
LIGHT WINDS WILL ALLOW TEMPERATURES TO COOL FAIRLY WELL. I LOWERED
THE TEMPERATURES FOR TONIGHT. THE COMBINATION OF THE TEMPERATURES
AND LIGHT WINDS WILL ALSO RESULT IN A PERIOD OF DANGEROUS WIND
CHILLS AROUND 20 TO 30 DEGREES BELOW ZERO LATE TONIGHT AND WHICH
WILL LINGER INTO TUESDAY MORNING.
TUESDAY LOOKS COLDER WITH PARTLY TO MOSTLY CLOUDY SKIES AS HIGH
PRESSURE DOMINATES THE REGION.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 302 PM CST MON FEB 3 2014
A RELATIVELY QUIET EXTENDED PERIOD WILL OCCUR ACROSS THE NORTHLAND
WITH MINIMAL CHANCES FOR SIGNIFICANT PRECIPITATION AND BELOW
NORMAL TEMPERATURES CONTINUING.
NORTHERLY WINDS WILL DEVELOP OVER LAKE SUPERIOR TUESDAY
NIGHT...THEN BACK WEDNESDAY. THE HIGH RESOLUTION SATELLITE IMAGE
FROM TODAY CONTINUES TO SHOW PLENTY OF ICE OVER LAKE
SUPERIOR...WITH SOME OPEN AREAS IN SPOTS. WE ADDED A MENTION OF
FLURRIES TO PORTIONS OF THE SOUTH SHORE TUESDAY NIGHT INTO
WEDNESDAY MORNING BUT DO NOT EXPECT ACCUMULATION. A SHORTWAVE WILL
ALSO DROP SOUTH INTO FAR NORTHERN MINNESOTA ON WEDNESDAY...BUT
FORCING AND MOISTURE APPEAR TO BE TOO LIMITED TO GET ANY SNOW SO
WE KEPT THOSE AREAS DRY.
ANOTHER SHORTWAVE WILL AFFECT MAINLY FAR NORTHERN MINNESOTA
THURSDAY NIGHT INTO FRIDAY. THE GFS AND ECMWF ARE IN DECENT
AGREEMENT SHOWING INCREASING CLOUDS AND A CHANCE FOR SNOW FOR
THURSDAY NIGHT...POSSIBLY INTO FRIDAY. AT THIS TIME...WE DID ADD
SOME SMALL POPS FOR THE FAR NORTH THURSDAY NIGHT...BUT KEPT FRIDAY
DRY. THERE COULD BE SOME LIGHT SNOW/FLURRIES THAT EXTEND FURTHER
SOUTH BOTH THURSDAY NIGHT AND FRIDAY...BUT ANY ACCUMULATION LOOKS
LIGHT AT THIS POINT.
WE KEPT THE REST OF THE EXTENDED PERIOD DRY. THERE ARE A COUPLE
MORE SHORTWAVES FORECAST TO AFFECT THE REGION...BUT THERE IS
QUITE A BIT OF UNCERTAINTY REGARDING THE TIMING/STRENGTH OF THE
WAVES AND WE WILL HAVE TO WAIT FOR LATER UPDATES TO ADD ANY POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1147 AM CST MON FEB 3 2014
CEILINGS FROM AROUND 3000FT TO 4500 FT WERE OCCURRING OVER
NORTHERN MINNESOTA...AND THEY SHOULD EXPAND TOWARD THE SOUTH
THIS AFTERNOON/EVENING. FLURRIES/LIGHT SNOW WAS ALSO OCCURRING
UNDER THESE CEILINGS. THE RAP SUGGESTS THE CLOUDS WILL BREAK UP
LATER THIS EVENING INTO THE OVERNIGHT HOURS...AND WE FOLLOWED THIS
TREND.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH -8 6 -12 5 / 0 0 10 10
INL -19 1 -20 2 / 10 0 10 10
BRD -13 5 -13 5 / 0 0 10 10
HYR -8 15 -8 8 / 0 0 10 10
ASX -4 12 -5 8 / 0 0 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM CST TUESDAY
FOR MNZ010-011-018-019-025-026-033>035.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1148 AM CST MON FEB 3 2014
.SHORT TERM...(TODAY THROUGH TUESDAY AFTERNOON)
ISSUED AT 310 AM CST MON FEB 3 2014
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND TEMPERATURES
AND SKY COVER. DRY PATTERN CONTINUES EARLY THIS WEEK...WITH COLD
CONDITIONS PERSISTING.
SFC RIDGE AXIS OVER WI AND INTO THE WRN GREAT LAKES CONTINUES TO
SHIFT TO THE EAST THIS MORNING AS A DRY/WEAK TROUGH MOVES IN FROM
THE WEST. THIS SFC FEATURE WILL MAINLY ACT TO INCREASE CLOUD COVER
TODAY...WITH NO REAL THREAT OF SNOW. CANNOT RULE OUT A FEW
FLURRIES...BUT NOT ENOUGH CONFIDENCE TO ADD TO THE FORECAST AT THIS
POINT. THE SFC FRONT WILL MOVE RATHER QUICKLY TO THE EAST TODAY AND
ANOTHER AREA OF HIGH PRESSURE WILL BUILD IN BEHIND THE DEPARTING
TROUGH. THERE IS ALSO AN UPPER S/W NORTH OF THE INTL BORDER THAT
COULD BRUSH THE NRN COUNTIES WITH ADDITIONAL CLOUD COVER THIS
AFTERNOON. SO...THE AMT OF CLOUD COVER WILL DEFINITELY BE A
CHALLENGE. WENT WITH A MORE PESSIMISTIC CLOUD FORECAST TODAY AND
INTO TONIGHT.
THERE IS A VERY WEAK WAA SIGNAL INDICATED IN THE 850MB TEMP LAYER
THIS AFTERNOON OVER THE SRN SECTIONS OF THE FORECAST AREA...WHICH
WILL ALLOW A GOOD PORTION OF THE NORTHLAND TO WARM INTO THE MID TO
UPPER TEENS. A WEAK PUSH A COLD AIR MASS TO THE NORTH WILL MOVE IN
THIS EVENING AND TONIGHT...AND DROP TEMPERATURES INTO THE SINGLE
DIGITS AND TEENS BELOW ZERO ONCE AGAIN. A LARGE AREA OF HIGH
PRESSURE WILL BUILD IN FROM THE WEST ON TUESDAY WITH DRY CONDITIONS
CONTINUING. THE AIR MASS ON TUESDAY WILL BE NOTICEABLY COLDER WITH
AFTERNOON HIGHS ONLY REACHING INTO THE SINGLE DIGITS FOR MOST OF THE
NORTHLAND. LOWER TO MID TEENS ARE POSSIBLE OVER PARTS OF NRN WI.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 AM CST MON FEB 3 2014
OVERALL QUIET EXTENDED PERIOD FOR THE REGION AS MODELS SHOW GOOD
AGREEMENT THAT A H85 LOW TRACKS WELL TO THE SOUTH OF THE DLH CWA
TUES/WED...KEEPING THE ACCUM SNOW ACROSS THE NEBRASKA/IOWA/ILLINOIS
CORRIDOR.
A REGION OF CYCLONIC FLOW ROTATING AROUND A CUT OFF LOW OVER HUDSON
BAY WILL SINK INTO THE BORDERLAND THURS. A FAST MOVING VORT WILL
SWING ACROSS THE BORDERLAND/ONTARIO THURS NIGHT/FRIDAY...TRIGGERING
VERY LIGHT SNOW/FLURRIES WITH LITTLE OR NO ACCUM. HAVE KEPT THE FCST
DRY ATTM AS TIMING THESE SMALL DISTURBANCES IS DIFFICULT AND THE
MOISTURE TO PRODUCE MORE THAN A TRACE/DUSTING OF SNOW LOOKS TO
REMAINS NORTH OF THE IN TL BORDER.
LATEST GFS/ECM BOTH SUGGEST A LONG WAVE TROUGH/H50 LOW OVER THE
PACIFIC NORTHWEST FRIDAY...TRANSLATES EAST ACROSS THE ROCKIES AND
INTO THE CENTRAL PLAINS THROUGH THE UPCOMING WEEKEND. THERE REMAINS
UNCERTAINTY IN THE STRENGTH OF THE NRN STREAM WAVE/VORT...AND THE
POTENTIAL FOR SNOW ACROSS THE NORTHLAND AS THE MOISTURE AND MAIN
AREA OF FORCING REMAINS FOCUS AROUND A STRONG VORT MAX WITH H85
CYCLOGENESIS SITUATED IN THE SOUTHERN PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1147 AM CST MON FEB 3 2014
CEILINGS FROM AROUND 3000FT TO 4500 FT WERE OCCURRING OVER
NORTHERN MINNESOTA...AND THEY SHOULD EXPAND TOWARD THE SOUTH
THIS AFTERNOON/EVENING. FLURRIES/LIGHT SNOW WAS ALSO OCCURRING
UNDER THESE CEILINGS. THE RAP SUGGESTS THE CLOUDS WILL BREAK UP
LATER THIS EVENING INTO THE OVERNIGHT HOURS...AND WE FOLLOWED THIS
TREND.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 13 -7 8 -11 / 0 0 0 10
INL 11 -17 0 -19 / 0 0 0 10
BRD 14 -9 7 -14 / 0 0 10 10
HYR 17 -4 13 -9 / 0 0 10 10
ASX 17 -2 13 -5 / 0 0 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...BJT
LONG TERM...GRANING
AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1152 AM CST Mon Feb 3 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 331 AM CST Mon Feb 3 2014
Cold high pressure will control our weather today, with a gradual
increase of high clouds expected during the afternoon. No major
changes to going temp trends, although did shave a couple of degrees
off on mid Missouri and the eastern Ozarks due to the cold start and
the increase of high clouds during the time of "max heating"...such
as it is in early February beneath a Canadian high...
Truett
.LONG TERM: (Tonight through Sunday)
Issued at 459 AM CST Mon Feb 3 2014
There are four primary forecast issues during this period: a winter
storm for Tu/Tu night, another Arctic air mass for W/Th, a weak vort
max moving across the area on Th/F, and another potential storm
system for Sa/Su.
Issue #1, winter storm for Tu/Tu night: Early morning water vapor
imagery and recent RAP analyses of the 1.5 PVU surface all show a
strong low pressure system just off the SoCal coast. The system was
partially sampled by 03/00z RAOBs in CA, but this feature`s path
through northern Mexico will likely preclude full sampling until it
reaches western TX around 12z Tu. This means that 1) models will
likely struggle to capture the true strength of the system, 2)
model depictions of the H5/H85/sfc low tracks may shift around a
bit, leading to changes in the forecast onset of precipitation as
well as changes to ptypes across southeast MO/southern IL, and 3)
last minute forecast adjustments to the axis of heaviest snowfall
may be required after the 12z models come in on Tue because those
runs will have incorporated the most recent upper air
observations.
Recent SREF/NAM/WRF/ECMWF/GEM runs depict H85 low tracks which match
very well with local climatology studies for heavy snowfall across
the northwest 1/3 of the CWA. BUFKIT soundings at KUIN, for example,
show a favorable cross-hair signature of rising motion within or
just below the DGZ occurring in an environment that is saturated wrt
ice. With at least ~50% confidence in heavy snow somewhere in the
northern or western part of the CWA, we have issued a Winter Storm
Watch (includes the Quincy and Columbia areas) from 12z Tue
through 12z Wed. The combination of initial WAA snow on Tue
followed by enhanced precipitation in the deformation zone on Tue
night could lead to snowfall totals of 6+" in or near this area.
Lesser snowfall totals (1-5") are possible across the rest of the
CWA (including the St. Louis metro area) due to WAA snow. Mixed
precipitation (including freezing rain and sleet) remains possible
on Tue, especially across the southeastern one-quarter of the CWA.
Any occurrence of sleet or freezing rain will reduce snowfall
totals. At this time, ice accretion of between a light glaze and
0.10" appears possible across the extreme southeastern CWA. Please
see the winter snow & ice graphics at
www.crh.noaa.gov/lsx/?n=stormtotalsnow for details.
Snow should taper off from west to east on late Tue night with some
lingering flurries possible on Wed afternoon.
Issue #2, Arctic air mass for W/Th: A 1040+ hPa surface high will
slide into the Plains on Tue night into Wed. The coldest
temperatures are expected from late Wed night into Thu morning,
especially over areas which will have received fresh snow cover.
Wind chill headlines may eventually be needed for northern portions
of the CWA due to wind chill values between -20 and -15 deg F from
late Wed night into Thu morning.
Issue #3, weak vort max for Th/F: Most models hint at a weak vort
max zipping through confluent flow aloft on Thu/Fri. There may be
enough forcing to squeeze out some light precipitation.
Issue #4, potential storm system for Sa/Su: ECMWF/GFS/GEM depict
the development of a highly elongated E-W trough/shear zone
spanning from OR to ME. A vort max peels off the western end near
WA/OR on Thu night and dives southeastward before swinging through
the south central CONUS over the weekend. This is a different
scenario compared to previous model runs which brought the
shortwave onshore from the Pacific. Chc PoPs are acceptable albeit
not preferable given this level of uncertainty at the end of the
extended forecast period.
Kanofsky
&&
.AVIATION: (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1124 AM CST Mon Feb 3 2014
VFR flight conditions and light east-northeast flow will continue
to prevail for the rest of the day and for at least the majority
of tonight. A storm system will move from the Great Plains into
the Mississippi Valley on Tuesday. IFR flight conditions in low
stratus and snow will overspread the area from the west through
the day. Timing and intensity remains uncertain, but the lowest
conditions/most intense snow will likely occur along and north of
the I-44/I-70 corridor. Further south, there will be a mix of
freezing rain and snow. Once precipitation begins, expect IFR
flight conditions to prevail at least into the daytime hours of
Wednesday.
Specifics for KSTL:
VFR flight conditions and light east-northeast flow will continue
to prevail at Lambert through at least Tuesday morning. A storm
system will move from the Great Plains into the Mississippi Valley
on Tuesday. IFR flight conditions in low stratus and snow will
overspread the area from the west through the day. Timing and
intensity remains uncertain, but the lowest conditions/most intense
snow will likely occur along and north of the I-44/I-70 corridor.
For Lambert, it appears that snow will begin during the early
afternoon. Latest guidance indicates that there will be an initial
burst of intense snow in the afternoon, and then the intensity
will decrease in the evening. Once the snow starts, expect IFR
conditions to prevail at least into the daytime hours of
Wednesday.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...WINTER STORM WATCH from Tuesday morning through late Tuesday
night FOR Audrain MO-Boone MO-Callaway MO-Cole MO-Knox MO-
Lewis MO-Lincoln MO-Marion MO-Moniteau MO-Monroe MO-
Montgomery MO-Pike MO-Ralls MO-Shelby MO.
IL...WINTER STORM WATCH from Tuesday morning through late Tuesday
night FOR Adams IL-Brown IL-Calhoun IL-Greene IL-Jersey IL-
Macoupin IL-Montgomery IL-Pike IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1200 PM CST MON FEB 3 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM CST MON FEB 3 2014
TODAY AND TONIGHT...SOME TRAPPED MOISTURE HAS DEVELOPED IN THE
PLATTE VALLEY THIS MORNING NEAR KOGA/NEDOR CAM AT OGALLALA. THE SNOW
FIELD HAS DEFIED ALL MODEL PREDICTIONS AND MAINTAINED A WEAK SFC
HIGH PRESSURE RIDGE NORTHWEST THROUGH THE PANHANDLE. NOT EVEN THE
RAP13 CAPTURES THIS FEATURE THIS MORNING. SO DENSE FOG ADVISORY IS
IN PLACE FOR KEITH AND DEUEL COUNTIES UNTIL 15Z THIS AM.
A WARM FRONT IS DEVELOPING THIS MORNING BUT IT IS ACROSS ERN
COLO/NWRN KS. THIS FRONT IS EXPECTED TO LIFT NORTH INTO WRN NEB
LATER TODAY AS AN ARCTIC FRONT...CURRENTLY MOVING THROUGH EDMONTON
ALBERTA...MOVES INTO MT. THIS FRONT WILL MERELY RECYCLE COLD AIR
NORTH WITH SOUTHEAST WIND AND VERY LIMITED VERTICAL MIXING.
BUT THERE IS MORE. THE NAM...GEM REGIONAL...RAP13 AND HRRR POOL
MOISTURE ALONG THE WARM FRONT AND PRODUCE SNOW AS THE FRONT LIFTS
INTO NCNTL NEB THIS MORNING AND THIS AFTERNOON. THE NAM SUGGEST
FLURRIES WHILE THE RAP AND HRRR SHOW SNOW ACCUMULATIONS OF AN INCH
OR LESS. HMMM...GIVEN THAT THE MODELS ARE HAVING TROUBLE CORRECTLY
ESTABLISHING A WARM SECTOR ON THE SNOW COVER AND SKY CONDITIONS ARE
CURRENTLY VFR EXCEPT FOR GROUND FOG...THE FORECAST IS VERY UNCERTAIN
TODAY BUT WE WILL TRY A 30 POP FOR SNOW SHOWERS AS THE FRONT LIFTS
NORTH. FORECAST ERRORS COULD BE LARGE WITH THIS ONE.
FCST HIGHS TODAY RANGE FROM THE UPPER 20S ACROSS THE SOUTH AND WEST
TO LOWER 30S NORTH AND EAST WHERE NO SNOW IS ON THE GROUND.
FOR TONIGHT...GET READY. AN ARCTIC FRONT WILL MOVE THROUGH THE FCST
AREA. THE FRONT IS A SLOW MOVER AND SFC WINDS BACK AROUND AND BECOME
NORTHEAST PRODUCING UPSLOPE WINDS AND A RAPID INCREASE IN RELATIVE
HUMIDITY BELOW 700 MB. TEMPERATURES 850MB-700MB FALL TO AROUND -14C
BEHIND THE FRONT SUPPORTING SNOW GROWTH WHILE THE UPSLOPE WINDS
PRODUCE WEAK LIFT. SNOW CHANCES INCREASE TO AROUND 50 PERCENT BY 12Z
TUESDAY MORNING AND SNOWFALL AMOUNTS SHOULD BE LESS THAN AN INCH.
LOWS TONIGHT SHOULD RANGE FROM SINGLE DIGITS NORTH TO AROUND 15F
SOUTH AND EAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 402 AM CST MON FEB 3 2014
12Z TUESDAY AND BEYOND. THE FOCUS OF THE EXTENDED FORECAST
CENTERS ON A PROLONGED PERIOD OF BITTERLY COLD TEMPERATURES AND
THE POTENTIAL OF SNOW MID-WEEK. MEDIUM RANGE FORECAST MODELS
REMAIN IN GOOD AGREEMENT WITH THE HANDLING OF THE SOUTHERN STREAM
SHORTWAVE. THE WAVE WILL ROTATE FROM THE SOUTHERN ROCKIES OUT ONTO
THE PLAINS ON TUESDAY...ALLOWING FOR WIDESPREAD SNOW ACROSS THE
REGION. THE MODELS CONTINUE TO FOCUS THE HEAVIEST QPF AND BEST
SNOW POTENTIAL SOUTH AND EAST OF THE CWA WITH THE TRACK OF THE H5
LOW FROM SOUTHWEST KANSAS INTO FAR SOUTHEAST NEBRASKA. HOWEVER
THERE CONTINUES TO BE SUPPORT OF INCREASING DPVA AND WEAK UPGLIDE
TARGETING PORTIONS OF THE FORECAST AREA THROUGH THE DAY ON
TUESDAY. THE HEAVIEST ANTICIPATED QPF ACROSS OUR CWA WILL BE FOUND
FROM SW NEB THROUGH SOUTHERN CUSTER COUNTY...BUT AT THAT THE MODEL
CONSENSUS ONLY SUGGESTS ~0.15" TOTAL QPF /WHICH IS DEEMED TOO
HIGH/. PROXIMITY SOUNDINGS FROM THIS AREA REVEAL A FAIRLY
EFFICIENT SNOW PRODUCING PROFILE AS A LARGE COLUMN OF SATURATED
AIR WILL BE CO-LOCATED WITHIN OMEGA AND FAVORABLE TEMPERATURES OF
-10 TO -18C. USING A 15-17:1 SLR INDICATES TWO OR THREE INCHES OF
SNOW POSSIBLE BY WEDNESDAY MORNING FOR OUR SOUTHEASTERN ZONES.
FURTHER WEST...ACROSS THE EASTERN PANHANDLE AND MUCH OF THE
SANDHILLS REGION...LIGHT SNOW WILL BE POSSIBLE AS THE NORTHERN
STREAM USHERS A TROUGH ACROSS WYOMING AND MONTANA. QPF WILL BE
LIGHTER WITH THIS SYSTEM...BUT GIVEN THE HIGH SLR/S AND THE
POTENTIAL OF 12+ HOURS OF LIGHT SNOW...AN INCH WITH LOCALIZED
HEAVIER AMOUNTS IS POSSIBLE. IN ADDITION TO THE LIGHT
SNOW...NORTHERLY WINDS MAY CAUSE SOME LOCALIZED BLOWING SNOW WITH
REDUCED VISIBILITY. ATTM THE STRONGEST GUSTS /UP TO 25 MPH/
TUESDAY LOOK TO REMAIN ACROSS EASTERN PORTIONS OF THE FORECAST
AREA. SNOW PRODUCTION WILL TAPER OFF QUICKLY WEDNESDAY MORNING AS
DRY AIR IS PULLED SOUTH BEHIND THE PASSING WAVE AND FORCING
SPREADS EAST.
ONTO TEMPERATURES AND SLIGHT CHANCE POPS LATE WEEK...ARCTIC AIR WILL BE
IN PLACE ACROSS THE CWA ON TUESDAY WITH HIGHS OF ONLY 8-15 ABOVE
ZERO. THESE TEMPERATURES WILL BE WARM COMPARED TO THE OVERNIGHT AND
WEDNESDAY AS ARCTIC AIR CONTINUES TO FILTER SOUTHEAST THROUGH THE
HIGH PLAINS. BY WEDNESDAY MORNING...H85 TEMPERATURES OF MINUS 22 OR
COLDER WILL BE ATOP THE REGION...WITH WIDESPREAD SUB-ZERO SFC
TEMPERATURES ANTICIPATED. HIGHS ON WEDNESDAY WILL REMAIN IN THE
SINGLE DIGITS FOR ALL LOCATIONS ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA. OVERNIGHT WEDNESDAY AND EARLY THURSDAY SHOULD BE THE
COLDEST PERIOD OF THE EXTENDED...AND POSSIBLY THIS ENTIRE WINTER
SEASON. RIGHT NOW MODEL GUIDANCE IS INDICATING THE POTENTIAL OF
MINUS 5 TO MINUS 15 FROM EAST TO WEST RESPECTIVELY...WHICH MAY BE
WARM GIVEN THE PROJECTED LOCATION OF THE ARCTIC HIGH AND POTENTIAL
FRESH SNOWPACK. TRENDED THE FORECAST FOR THE WEDNESDAY THROUGH
FRIDAY MORNING TIMEFRAME TOWARD THE BCGEMREG /DUE TO ITS RECENT
PERFORMANCE/ AND THE ADJMEXBC AS THE GFS SEEMS TO BE HEADING IN THE
RIGHT DIRECTION. WITH THE BITTERLY COLD TEMPERATURES ANY AMOUNT OF
WIND WOULD ALLOW FOR CRITICALLY LOW WIND CHILL READINGS. WIND CHILL
ADVISORIES MAY BE NEEDED WEDNESDAY THROUGH THURSDAY MORNING.
TEMPERATURES SLOWLY MODERATE LATE WEEK INTO NEXT WEEKEND IN ADVANCE
OF THE NEXT TROUGH OF LOW PRESSURE ORGANIZING ACROSS THE WESTERN
STATES. THIS TROUGH IS SHOWN TO REMAIN PROGRESSIVE WITH MOST OF
IT/S ENERGY AFFECTING THE SOUTHERN PLAINS. FOR NOW WILL MAINTAIN
SLIGHT CHANCE POPS FRIDAY INTO SATURDAY. OTHERWISE TEMPERATURES
WILL SLOWLY MODERATE INTO THE WEEKEND...BUT REMAIN WELL BELOW
AVERAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1159 AM CST MON FEB 3 2014
AFTERNOON DISTURBANCE LIFTING NORTHEAST ACROSS CENTRAL NEBRASKA
AND WILL PROVIDE A LITTLE LIFT FOR SOME FLURRIES OR LIGHT SNOW.
WINDS NOT THAT STRONG JUST YET AND LITTLE IMPACT EXPECTED FROM
THE SNOW AS CIGS/VSBY SHOULD REMAIN GENERALLY VFR. OVERNIGHT INTO
TOMORROW A TROUGH WILL LIFT ACROSS THE AREA WITH A BETTER CHANCE
FOR ACCUMULATION SNOW. COULD ALSO SEE A BRIEF PERIOD OF FOG IN
THE PLATTE RIVER VALLEY LATE TONIGHT INTO TOMORROW. THE START
TIME OF THE SNOW UNCERTAIN AS A MID DRY LAYER WILL HAVE TO BE
OVERCOME FIRST...OTHERWISE CIGS AND VSBY DROP TO MVFR AND AT
TIMES IFR WITH THE NEXT ROUND OF SNOW TUESDAY MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
312 PM EST MON FEB 3 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA LATE THIS
AFTERNOON...ACCOMPANIED BY SCATTERED SHOWERS AND MUCH COOLER AIR.
THE FRONT WILL STALL SOUTH OF THE AREA TONIGHT AND THEN RETURN
NORTH AS A WARM FRONT LATE ON TUESDAY. ANOTHER COLD FRONT WILL
QUICKLY CROSS THE AREA ON WEDNESDAY. HIGH PRESSURE WILL BUILD IN
FROM THE NORTH ON THURSDAY AND FRIDAY. A STORM SYSTEM WILL BRING
UNSETTLED WEATHER TO THE REGION OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2:00 PM MONDAY...LOW PRESSURE RACING OFF TO THE NORTHEAST
WEST OF THE LOCAL FORECAST AREA WILL DRAG A COLD FRONT THROUGH THE
COASTAL CAROLINAS LATER TODAY AS THE LOW LIFTS FURTHER OFF TO THE
NORTHEAST. THIS FRONT WILL DROP DOWN FROM THE NORTH REACHING THE
CAPE FEAR COAST AROUND SUNSET.
TIGHTENED GRADIENT FLOW AHEAD OF THE FRONT PRODUCING GUSTY SOUTHWEST
WINDS KEEPING TEMPS UP AROUND 70 MOST PLACES INTO THIS AFTERNOON.
VERY WARM AND MOIST AIR MASS WILL REMAIN IN PLACE AHEAD OF COLD
FRONT WITH DEWPOINT TEMPS INTO THE 60S. THIS WARMER MOISTURE RICH
AIR MOVING OVER THE COOLER COASTAL WATERS PRODUCED SOME DENSE FOG
OVER THE WATERS AND JUST ALONG THE COAST. VISIBILITIES JUST ALONG
THE COAST REMAINED VARIABLE INTO THIS AFTERNOON BUT WINDS WERE
BEGINNING TO SHIFT TO A MORE W-SW DIRECTION WHICH WILL HELP TO
PUSH SEA FOG AWAY FROM THE COAST. PLACES FURTHER INLAND WILL
CONTINUE TO SEE LOW CLOUDS LIFTING AND BREAKS IN THE CLOUDS BUT
WILL ALSO SEE ISOLATED SHOWERS DEVELOPING AS A MORE CONVECTIVE
TYPE ATMOSPHERE EXISTS WITH WEAK INSTABILITY AND A FAIRLY DECENT
CAP PRESENT UP AROUND 15K FT. HRRR DEPICTING THE EVOLUTION OF SHOWER
ACTIVITY QUITE WELL SO FAR AND IT DOES SHOW ONLY ISOLATED SHOWERS
OUT AHEAD OF FRONT WITH MORE SHOWERS ASSOCIATED WITH LIFT ALONG
FRONT ITSELF. THIS SHOULD REACH INTO OUR NW PORTIONS OF CWA INTO
ROBESON AND MARLBORO COUNTIES BY 4PM AND WILL CONTINUE TO PROGRESS
SOUTH TO SOUTHEAST REACHING THE CAPE FEAR COAST AROUND SUNSET.
CONTINUES TO LOOK LIKE BEST CHC OF PCP WILL BE ASSOCIATED WITH
FRONT ITSELF AS ANY MID TO UPPER LEVEL SUPPORT CONTINUES TO MOVE
OFF TO THE NORTHEAST TOWARD THE MID ATLANTIC COAST. EXPECT
BASICALLY LOW TOPPED SHOWER ACTIVITY WITH POPS RANGING FROM 30-50
PERCENT...HIGHEST IN THE BENNETTSVILLE-LUMBERTON AREA AND LOWEST
ALONG THE SANTEE RIVER.
FRONT WILL NOT MAKE IT MUCH PAST THE NORTHEAST SOUTH CAROLINA
COAST BEFORE STALLING OUT TONIGHT. SHALLOW COOL AIR WILL MOVE IN
BEHIND THE FRONT AS HIGH PRESSURE TRIES TO BUILD IN FROM THE
NORTH...BUT WITH THE PROGRESSIVE NATURE OF OUR PATTERN...ANOTHER
LOW QUICKLY FOLLOWS IN ITS PATH. THE SHORTWAVE DIGGING DOWN INTO
TEXAS BY EARLY TUES MORNING WILL ACT TO BUILD THE SOUTHWESTERN
ATLANTIC RIDGE SHARPENING THE FLOW ALOFT AND MAINTAINING A
PERSISTENT SW FLOW ALOFT. A VERY STEEP INVERSION WILL SET UP WITH
DECENT ISENTROPIC LIFT LEADING THE WAY TO LOW STRATUS AND LIGHT
RAIN AND DRIZZLE HEADING INTO THE EARLY MORNING HOURS. HAVE KEPT
POPS AS IS WHICH DEPICT THE PROGRESSION OF THE PCP ASSOCIATED WITH
FRONT VERY WELL AND THEN ALLOW FOR OVERRUNNING OF WARM HUMID AIR
OVER THE SHALLOW COOL AIR TO PRODUCE MORE STABLE PCP OVERNIGHT
INTO TUES MORNING.
TEMPS WILL DROP A GOOD 20 TO 30 DEGREES IN SHALLOW CAA THROUGH THE
NIGHT. OVERNIGHT LOWS WILL REACH DOWN JUST BELOW 40 OVER MOST
INLAND AND NORTH CAROLINA ZONES BUT WHILE DOWN ALONG THE NORTHEAST
SOUTH CAROLINA COAST FROM GRAND STRAND SOUTH WILL REMAIN IN THE
MID 40S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3:00 PM MONDAY...A VERY PROGRESSIVE SERIES OF FRONTAL
PASSAGES WILL KEEP IN THE CHANCES FOR LIQUID PRECIPITATION THROUGH
VIRTUALLY ALL OF THE SHORT TERM. PERIOD STARTS OUT WITH AN OVER-
RUNNING PATTERN IN PLACE...BRINGING CLOUDY SKIES AND THE CHANCE OF
RAIN AND DRIZZLE FOR TUESDAY. THE WARM FRONT ASSOCIATED WITH THIS
PATTERN WILL LIFT NORTH ACROSS THE FORECAST AREA LATE ON TUESDAY
AS A COLD FRONT APPROACHES FROM THE WEST. MODEL SOUNDINGS CONFIRM
WHAT ONE WOULD EXPECT IN THIS SCENARIO...WITH PRECIPITATION
BECOMING MORE CONVECTIVE IN NATURE. THIS WILL BE ESPECIALLY TRUE
DURING THE DAY AND EVENING ON WEDNESDAY AS THE NEXT COLD FRONT
DROPS SOUTHEAST ACROSS THE FORECAST AREA. EXPECT PRECIP TO SHUT
DOWN BY AROUND MIDNIGHT ON WEDNESDAY NIGHT AFTER FROPA...WITH P/W
VALUES DROPPING FROM THE 1.25 INCH RANGE PRE-FROPA TO UNDER A HALF
AN INCH POST-FROPA.
DAYTIME TEMPERATURES WILL SHOW WIDE SWINGS. HIGHS ON TUESDAY WILL
RANGE FROM MID 40S INLAND TO LOWER AND MID 50S ALONG THE COAST AS
A COOL AND MOIST WEDGE HOLDS ON OVER THE EASTERN CAROLINAS. HIGHS
ON WEDNESDAY WILL SOAR INTO THE LOWER TO MID 70S MOST PLACES AS
LOW LEVEL FLOW TURNS SOUTHWESTERLY IN ADVANCE OF THE COLD FROPA.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3:00 PM MONDAY...CONFIDENCE IS INCREASING THAT A COMPLEX AND
LONG-LASTING STORM SYSTEM WILL IMPACT THE REGION BETWEEN FRIDAY
NIGHT AND MONDAY MORNING...CREATING AN EXTENDED PERIOD OF
UNSETTLED WEATHER. WHILE THURSDAY IS LIKELY TO BE MOSTLY SUNNY AS
HIGH PRESSURE DRIFTS OVERHEAD...SLOWLY TRANSITIONING TO A WEDGE-
TYPE RIDGE...TEMPS THURSDAY WILL BE WELL BELOW CLIMO THANKS TO CAA
BEHIND A STALLED COLD FRONT SOUTH OF THE AREA. BY THURSDAY NIGHT
THOUGH...CLOUD COVER WILL BEGIN TO INCREASE AS WEAK ISENTROPIC
LIFT DEVELOPS ATOP THE STRENGTHENING WEDGE. THURSDAY NIGHT WILL BE
MOSTLY DRY...BUT AS ISENTROPIC LIFT BECOMES MORE INTENSE
FRIDAY...LIGHT RAIN WILL BREAK OUT ACROSS THE AREA.
ISENTROPIC LIFT ENHANCES DUE TO STRENGTHENING MID-LEVEL SW FLOW
DOWNWIND OF A DEEPENING 5H TROUGH WHICH WILL DROP INTO THE MTN
WEST BEFORE MOVING ACROSS THE EASTERN 2/3RDS OF THE NATION AND
SPAWNING A STRONG SURFACE LOW PRESSURE DURING THE WKND. MODELS
SUGGEST A MILLER-B TYPE SCENARIO SAT-MON...AND ALTHOUGH TIMING
DIFFERENCES STILL EXIST AMONG THE GUIDANCE...IT APPEARS A VERY
UNSETTLED PERIOD OF WEATHER WILL OCCUR WITH SIGNIFICANT CLOUD
COVER AND PERIODS OF RAINFALL...POTENTIALLY HEAVY AT TIMES. WPC
HAS PAINTED 1-2" OF QPF ACROSS THE AREA ALREADY...AND MOS
P-NUMBERS ARE ALREADY IN THE LIKELY RANGE. WILL RAISE POP TO HIGH-
CHC/LOW LKLY FOR THE WKND AS IT DOES LOOK INCREASINGLY LIKELY THAT
A LARGE AREA OF LOW PRESSURE WILL IMPACT THE REGION. COLD FRONT
WILL CROSS THE AREA BEHIND THE SYSTEM DURING MONDAY...CLEARING
THINGS OUT FOR THE BEGINNING OF THE WORK WEEK...BUT WITH A RETURN
TO MUCH COLDER TEMPS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...SEA FOG/STRATUS LURKING JUST OFFSHORE. ANOTHER
CHALLENGING FORECAST WITH RESPECT TO CEILINGS AND VISIBILITIES. THE
CWA IS PREDOMINATELY IFR...HOWEVER POCKETS OF VFR ARE OCCURRING OVER
PORTIONS OF THE COAST. LOOK FOR MVFR/IFR CONDITIONS FOR MOST OF THE
AFTERNOON. LOW PRESSURE WILL MOVE NORTHEAST TODAY AND OFF THE COAST
THIS AFTERNOON...DRAGGING ACROSS A WEAK COLD FRONT. SOME ISOLATED
SHOWERS ARE POSSIBLE...COVERAGE LIMITED. A WEDGE SETS UP TONIGHT WITH
MORE IFR CONDITIONS EXPECTED. LOOK FOR A WIND SHIFT TO THE NORTH
WITH THE FROPA...JUST AFTER 00Z. TUESDAY...CONTINUED PREDOMINATELY
IFR WITH A NORTHEAST WIND.
EXTENDED OUTLOOK...EXPECT IFR CIGS WITH RAIN POSSIBLE ON TUESDAY.
MVFR/IFR CONDITIONS WITH SHOWERS ARE LIKELY ON WEDNESDAY AS A COLD
FRONT PUSHES THROUGH OUR CWA. VFR THURSDAY. LOW CONFIDENCE FOR
POSSIBLE SHOWERS FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2:00 PM MONDAY...LOW PRESSURE RACING OFF TO THE NORTHEAST
WILL DRAG A COLD FRONT THROUGH THE COASTAL WATERS EARLY THIS
EVENING. THE FRONT SHOULD DROP SOUTH REACHING THE CAROLINAS COAST
JUST AROUND SUNSET. TIGHTENED GRADIENT FLOW AHEAD OF THIS FRONT
WILL MAINTAIN GUSTY WINDS UP AROUND 15 TO 20 KTS. THE WINDS WILL
SHIFT FROM SOUTHWEST TO A MORE WESTERLY DIRECTION THROUGH THE
AFTERNOON. THIS WILL HELP TO MOVE ANY DENSE SEA FOG AWAY FROM THE
COAST DISSIPATING AS DRIER AIR MOVES IN THROUGH LATE DAY.
PRECAUTIONARY CONDITIONS WILL CONTINUE THROUGH THE AFTERNOON HOURS
AS SEAS AWAY FROM SHORE REMAIN UP AROUND 4-5 FEET AND WINDS REMAIN
UP NEAR 20 KTS.
THE COLD FRONT WILL DROP SOUTH MOVING FURTHER OFFSHORE EARLY THIS
EVENING AS SHALLOW COOL AIR MOVES IN WITH HIGH PRESSURE BEHIND
FRONT. THE BOUNDARY WILL STALL ACROSS SOUTHERN SOUTH
CAROLINA...WITH N WINDS TURNING NE AND CONTINUING THROUGH THE
NIGHT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3:00 PM MONDAY...WINDS WILL EVENTUALLY COME FROM ALL POINTS
OF THE COMPASS THROUGH THE NEAR TERM AS A COMPLEX SERIES OF FRONTS
MOVES ACROSS THE WATERS. DUE TO THE SPEED AND NATURE OF THESE
SYSTEMS...IT IS BEST TO CONSULT THE LATEST FORECAST FOR THE MOST
UPDATED DETAILS ON WIND SPEED/DIRECTION AND SEA STATE.
HOWEVER...IT DOE LOOK LIKE WE COULD SEE SMALL CRAFT ADVISORY
CONDITIONS DEVELOP ON WEDNESDAY AS SOUTHWESTERLY WINDS BUILD SEAS
INTO THE 4 TO 6 FT RANGE. RAIN...DRIZZLE AND RAINSHOWERS ARE
LIKELY THROUGH MUCH OF THE PERIOD.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3:00 PM MONDAY...DEVELOPING WEDGE OF HIGH PRESSURE WILL
CREATE RATHER UNIFORM NE WINDS THROUGH THE PERIOD...BUT SOME
UNCERTAINTY DEVELOPS TOWARDS THE WEEKEND AS A LOW PRESSURE SYSTEM
WILL DEVELOP NEAR THE AREA. HIGH PRESSURE RIDGES DOWN THE COAST
THURSDAY...DEVELOPING INTO A WEDGE SETUP BY FRIDAY. THIS DRIVES
STRENGTHENING NE WINDS TO 15-20 KTS MUCH OF THURSDAY AND FRIDAY.
COASTAL TROUGH MOVES TOWARDS THE AREA SATURDAY...AND A WAVE OF LOW
PRESSURE MAY TRY TO DEVELOP ALONG IT. FOR NOW HAVE KEPT NE WINDS
ONGOING SATURDAY...BUT WITH A WEAKER GRADIENT DRIVING SLIGHTLY
DECREASED SPEEDS. SEAS WILL BE 3-5 FT THROUGH THE MAJORITY OF THE
PERIOD WITH A NE WIND WAVE PREDOMINANT...BUT MUCH LOWER WAVE
AMPLITUDES ARE LIKELY SW OF BRUNSWICK COUNTY WHERE NE WIND WAVES
ARE SHADOWED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...REK
NEAR TERM...RGZ
SHORT TERM...REK
LONG TERM...JDW
AVIATION...DL
MARINE...REK/JDW/RGZ
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
232 PM EST MON FEB 3 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA FROM THE NORTHWEST LATE THIS
AFTERNOON ACCOMPANIED BY SCATTERED SHOWERS. THE FRONT WILL STALL
SOUTH OF THE AREA TONIGHT THEN RETURN NORTH AS A WARM FRONT LATE
TUESDAY. ANOTHER COLD FRONT WILL QUICKLY CROSS THE AREA LATE
WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTH ON THURSDAY. A
GULF COAST STORM MAY BRING RAIN TO THE REGION LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM MONDAY...LOW PRESSURE RACING OFF TO THE NORTHEAST
WEST OF THE LOCAL FORECAST AREA WILL DRAG A COLD FRONT THROUGH THE
COASTAL CAROLINAS LATER TODAY AS THE LOW LIFTS FURTHER OFF TO THE
NORTHEAST. THIS FRONT WILL DROP DOWN FROM THE NORTH REACHING THE
CAPE FEAR COAST AROUND SUNSET.
TIGHTENED GRADIENT FLOW AHEAD OF THE FRONT PRODUCING GUSTY SOUTHWEST
WINDS KEEPING TEMPS UP AROUND 70 MOST PLACES INTO THIS AFTERNOON.
VERY WARM AND MOIST AIR MASS WILL REMAIN IN PLACE AHEAD OF COLD
FRONT WITH DEWPOINT TEMPS INTO THE 60S. THIS WARMER MOISTURE RICH
AIR MOVING OVER THE COOLER COASTAL WATERS PRODUCED SOME DENSE FOG
OVER THE WATERS AND JUST ALONG THE COAST. VISIBILITIES JUST ALONG
THE COAST REMAINED VARIABLE INTO THIS AFTERNOON BUT WINDS WERE
BEGINNING TO SHIFT TO A MORE W-SW DIRECTION WHICH WILL HELP TO
PUSH SEA FOG AWAY FROM THE COAST. PLACES FURTHER INLAND WILL
CONTINUE TO SEE LOW CLOUDS LIFTING AND BREAKS IN THE CLOUDS BUT
WILL ALSO SEE ISOLATED SHOWERS DEVELOPING AS A MORE CONVECTIVE
TYPE ATMOSPHERE EXISTS WITH WEAK INSTABILITY AND A FAIRLY DECENT
CAP PRESENT UP AROUND 15K FT. HRRR DEPICTING THE EVOLUTION OF SHOWER
ACTIVITY QUITE WELL SO FAR AND IT DOES SHOW ONLY ISOLATED SHOWERS
OUT AHEAD OF FRONT WITH MORE SHOWERS ASSOCIATED WITH LIFT ALONG
FRONT ITSELF. THIS SHOULD REACH INTO OUR NW PORTIONS OF CWA INTO
ROBESON AND MARLBORO COUNTIES BY 4PM AND WILL CONTINUE TO PROGRESS
SOUTH TO SOUTHEAST REACHING THE CAPE FEAR COAST AROUND SUNSET.
CONTINUES TO LOOK LIKE BEST CHC OF PCP WILL BE ASSOCIATED WITH
FRONT ITSELF AS ANY MID TO UPPER LEVEL SUPPORT CONTINUES TO MOVE
OFF TO THE NORTHEAST TOWARD THE MID ATLANTIC COAST. EXPECT
BASICALLY LOW TOPPED SHOWER ACTIVITY WITH POPS RANGING FROM 30-50
PERCENT...HIGHEST IN THE BENNETTSVILLE-LUMBERTON AREA AND LOWEST
ALONG THE SANTEE RIVER.
FRONT WILL NOT MAKE IT MUCH PAST THE NORTHEAST SOUTH CAROLINA
COAST BEFORE STALLING OUT TONIGHT. SHALLOW COOL AIR WILL MOVE IN
BEHIND THE FRONT AS HIGH PRESSURE TRIES TO BUILD IN FROM THE
NORTH...BUT WITH THE PROGRESSIVE NATURE OF OUR PATTERN...ANOTHER
LOW QUICKLY FOLLOWS IN ITS PATH. THE SHORTWAVE DIGGING DOWN INTO
TEXAS BY EARLY TUES MORNING WILL ACT TO BUILD THE SOUTHWESTERN
ATLANTIC RIDGE SHARPENING THE FLOW ALOFT AND MAINTAINING A
PERSISTENT SW FLOW ALOFT. A VERY STEEP INVERSION WILL SET UP WITH
DECENT ISENTROPIC LIFT LEADING THE WAY TO LOW STRATUS AND LIGHT
RAIN AND DRIZZLE HEADING INTO THE EARLY MORNING HOURS. HAVE KEPT
POPS AS IS WHICH DEPICT THE PROGRESSION OF THE PCP ASSOCIATED WITH
FRONT VERY WELL AND THEN ALLOW FOR OVERRUNNING OF WARM HUMID AIR
OVER THE SHALLOW COOL AIR TO PRODUCE MORE STABLE PCP OVERNIGHT
INTO TUES MORNING.
TEMPS WILL DROP A GOOD 20 TO 30 DEGREES IN SHALLOW CAA THROUGH THE
NIGHT. OVERNIGHT LOWS WILL REACH DOWN JUST BELOW 40 OVER MOST
INLAND AND NORTH CAROLINA ZONES BUT WHILE DOWN ALONG THE NORTHEAST
SOUTH CAROLINA COAST FROM GRAND STRAND SOUTH WILL REMAIN IN THE
MID 40S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...TUE WILL BE CLOUDY AND COOL IN THE CAROLINAS
WITH HIGH PRESSURE RIDGING DOWN THE EAST COAST. ISENTROPIC LIFT AND
NEAR SATURATION OF THE LOW LEVELS WILL KEEP LIGHT RAIN A POSSIBILITY
TUE. WEDGE STARTS TO BREAK DOWN LATE TUE AS SOUTHERN STREAM
SHORTWAVE EMERGES FROM THE SOUTHWEST. MID LEVEL WAVE HELPS SURFACE
LOW DEVELOP ON A FRONT STALLED ALONG THE TX COAST TUE MORNING. THE
SURFACE LOW LIFTS NORTHEAST ACROSS THE LOWER MS VALLEY AND INTO THE
TN VALLEY TUE EVENING. AS THE LOW MOVES NORTHEAST IT DRAGS THE
FRONT/TROUGH STALLED OFF THE CAROLINA COAST NORTHEAST AS A WARM
FRONT. TIMING THE MOVEMENT OF THE FRONT WILL PLAY A ROLE IN
TEMPERATURES TUE AND TUE NIGHT. CURRENTLY IT APPEARS THE HIGH TEMP
ON TUE WILL OCCUR LATE IN THE DAY WITH THE LOW OCCURRING TUE
EVENING. ALONG THE COAST THE HIGH AND LOW TEMPS COULD END UP BEING
THE SAME. TEMPERATURES WILL STEADILY RISE TUE NIGHT ENDING UP AROUND
60 WED MORNING.
DESPITE ABUNDANT CLOUD COVER WED TEMPS WILL END UP WELL ABOVE CLIMO
WITH MANY AREAS RISING INTO THE 70S. A STRONG COLD FRONT WILL MOVE
ACROSS THE AREA LATE IN THE DAY...LIKELY ACCOMPANIED BY CONVECTION.
AHEAD OF THE FRONT SCATTERED SHOWERS WITH THE POTENTIAL FOR A FEW
RUMBLES OF THUNDER WILL BE POSSIBLE. ALTHOUGH MOISTURE WILL BE
ABUNDANT INSTABILITY IS LIMITED. IN ADDITION LOW LEVEL JET IS RATHER
WEAK...AND GROWING WEAKER AS THE DAY PROGRESSES. AT THIS POINT
STRONG STORMS SEEM LIKE A LONG SHOT LET ALONE ANYTHING SEVERE. BEST
PRECIP CHANCES WILL BE ALONG THE FRONT WHERE LOW LEVEL CONVERGENCE
CAN TAP INTO THE LIMITED INSTABILITY. THINK A BROKEN LINE OF
SOMEWHAT STRONGER CONVECTION...CONTAINING A LITTLE MORE
THUNDER...WILL MOVE ACROSS THE AREA EARLY WED EVENING. THIS ACTIVITY
STILL DOES NOT LOOK PARTICULARLY IMPRESSIVE AS FAR AS SEVERE WEATHER
IS CONCERNED...BUT WILL CONTINUE TO MONITOR.
STRONG COLD ADVECTION FOLLOWS THE FRONT WED NIGHT WITH TEMPERATURES
DROPPING INTO THE UPPER 30S TO AROUND 40. DEEP DRY AIR SPREADS OVER
THE REGION WED NIGHT THOUGH BOUNDARY LAYER MOISTURE AS WELL AS SOME
MOISTURE ABOVE 300 MB LINGERS THROUGH THE END OF THE PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...MAJORITY OF THE PERIOD WILL SEE UNSETTLED
WEATHER CONTINUE WITH WEDGE SETTING UP FRI AND LASTING THROUGH THE
END OF THE PERIOD. THU APPEARS TO BE THE ONLY DAY OF THE PERIOD
WHERE SUNSHINE WILL BE PREVALENT...THOUGH TEMPERATURES WILL STILL
END UP BELOW CLIMO. STRONG COLD ADVECTION IN THE WAKE OF THE COLD
FRONT LATE WED WILL CONTINUE INTO THU AFTERNOON BUT IN A WEAKENED
STATE. HIGHS THU WILL END UP AROUND 50 IN MOST AREAS WITH LOWS THU
NIGHT DROPPING INTO THE LOW TO MID 30S. TEMPS WED NIGHT MAY LEVEL
OUT AFTER MIDNIGHT...ASSOCIATED WITH AN INCREASE IN CLOUD COVER.
AS MENTIONED WEDGE SETS UP EARLY FRI AND HOLDS STRONG THROUGH THE
WEEKEND. DEEP SOUTHWEST FLOW ABOVE 3K FT WILL PUMP PLENTY OF
MOISTURE INTO THE REGION THROUGH SUN. INCREASING ISENTROPIC AS EARLY
AS MIDDAY FRI TAPS INTO DEEPER MOISTURE...GENERATING LIGHT RAIN IN
THE REGION. OVER THE WEEKEND A SOUTHERN STREAM SYSTEM WILL EMERGE
FROM THE SOUTHWEST. LOW PRESSURE WILL DEVELOP ALONG THE CENTRAL GULF
COAST LATE SAT AND LIFT NORTH THROUGH SUN. STILL UNCERTAIN IF THE
WEDGE WILL BREAK DOWN OR IF A TRIPLE POINT LOW WILL FORM ALONG OR
OFF THE CAROLINA COAST LATE IN THE PERIOD. EITHER SOLUTION WILL KEEP
THE REGION CLOUDY WITH INCREASED RAIN CHANCES...THOUGH TEMP
DIFFERENCE WOULD BE SIGNIFICANT. HAVE LOW CONFIDENCE THIS FAR IN
ADVANCE AND FOR NOW WILL MAINTAIN A WET FORECAST WITH TEMPS NEAR
CLIMO FOR THE WEEKEND.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...SEA FOG/STRATUS LURKING JUST OFFSHORE. ANOTHER
CHALLENGING FORECAST WITH RESPECT TO CEILINGS AND VISIBILITIES. THE
CWA IS PREDOMINATELY IFR...HOWEVER POCKETS OF VFR ARE OCCURRING OVER
PORTIONS OF THE COAST. LOOK FOR MVFR/IFR CONDITIONS FOR MOST OF THE
AFTERNOON. LOW PRESSURE WILL MOVE NORTHEAST TODAY AND OFF THE COAST
THIS AFTERNOON...DRAGGING ACROSS A WEAK COLD FRONT. SOME ISOLATED
SHOWERS ARE POSSIBLE...COVERAGE LIMITED. A WEDGE SETS UP TONIGHT WITH
MORE IFR CONDITIONS EXPECTED. LOOK FOR A WIND SHIFT TO THE NORTH
WITH THE FROPA...JUST AFTER 00Z. TUESDAY...CONTINUED PREDOMINATELY
IFR WITH A NORTHEAST WIND.
EXTENDED OUTLOOK...EXPECT IFR CIGS WITH RAIN POSSIBLE ON TUESDAY.
MVFR/IFR CONDITIONS WITH SHOWERS ARE LIKELY ON WEDNESDAY AS A COLD
FRONT PUSHES THROUGH OUR CWA. VFR THURSDAY. LOW CONFIDENCE FOR
POSSIBLE SHOWERS FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM MONDAY...LOW PRESSURE RACING OFF TO THE NORTHEAST
WILL DRAG A COLD FRONT THROUGH THE COASTAL WATERS EARLY THIS
EVENING. THE FRONT SHOULD DROP SOUTH REACHING THE CAROLINAS COAST
JUST AROUND SUNSET. TIGHTENED GRADIENT FLOW AHEAD OF THIS FRONT
WILL MAINTAIN GUSTY WINDS UP AROUND 15 TO 20 KTS. THE WINDS WILL
SHIFT FROM SOUTHWEST TO A MORE WESTERLY DIRECTION THROUGH THE
AFTERNOON. THIS WILL HELP TO MOVE ANY DENSE SEA FOG AWAY FROM THE
COAST DISSIPATING AS DRIER AIR MOVES IN THROUGH LATE DAY.
PRECAUTIONARY CONDITIONS WILL CONTINUE THROUGH THE AFTERNOON HOURS
AS SEAS AWAY FROM SHORE REMAIN UP AROUND 4-5 FEET AND WINDS REMAIN
UP NEAR 20 KTS.
THE COLD FRONT WILL DROP SOUTH MOVING FURTHER OFFSHORE EARLY THIS
EVENING AS SHALLOW COOL AIR MOVES IN WITH HIGH PRESSURE BEHIND
FRONT. THE BOUNDARY WILL STALL ACROSS SOUTHERN SOUTH
CAROLINA...WITH N WINDS TURNING NE AND CONTINUING THROUGH THE
NIGHT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...NORTHEAST FLOW WILL DECREASE FROM 15 TO 20 KT AT
THE START OF THE PERIOD TO 10 TO 15 KT TUE EVENING AS COASTAL TROUGH
MOVES TO THE COAST. ONCE THIS FEATURE MOVES ONSHORE...TUE
NIGHT...EAST TO SOUTHEAST WINDS WILL DEVELOP. SPEEDS START OUT 10 TO
15 KT BUT INCREASE TO 15 TO 20 KT AND VEER TO SOUTHWEST BY WED
MORNING. A STRONG COLD FRONT WILL APPROACH FROM THE WEST DURING THE
DAY WITH WINDS INCREASING TO A SOLID 20 KT JUST BEFORE THE FRONT
REACHES THE COAST. FRONT IS QUICK TO MOVE OFFSHORE...PUSHING EAST OF
THE WATERS BY MIDNIGHT. PINCHED GRADIENT AND STRONG COLD ADVECTION
BEHIND THE FRONT WILL KEEP WINDS CLOSE TO 20 KT AS THEY VEER TO
FIRST WEST AND THEN NORTHWEST OVERNIGHT. WINDS WILL BE NORTH TO
NORTHEAST BY THE END OF THE PERIOD. SEAS 3 TO 5 FT ON TUE START TO
BUILD TUE NIGHT ONCE SOUTHERLY FLOW DEVELOPS. SEAS WILL LIKELY
EXCEED 6 FT DURING THE DAY WED AND IT CONTINUES TO APPEAR A SCA
HEADLINE IS LIKELY.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...NORTHEAST FLOW WILL REMAIN 15 TO 20 KT THROUGH
THE PERIOD. A COMBINATION OF HIGH PRESSURE BUILDING DOWN THE EAST
COAST AND A FRONT/TROUGH STALLED EAST OF THE WATERS WILL MAINTAIN A
PINCHED GRADIENT ALONG THE EAST COAST. EXTENDED PERIOD OF STRONGER
NORTHEAST FLOW WILL BUILD SEAS FROM 2 TO 4 FT ON THU TO 3 TO 5 FT
WITH ISOLATED 6 FT ON FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ250-
252-254-256.
&&
$$
NEAR TERM...RGZ
SHORT TERM...III
LONG TERM...III
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
339 PM CST MON FEB 3 2014
.DISCUSSION...
ACTIVE LATE WINTER WINTER PATTERN THIS WEEK. MIDAFTERNOON GOES
WATER VAPOR IMAGERY SHOWED AN UPPER LEVEL LOW OVER THE FAR
NORTHERN GULF OF CALIFORNIA. THIS LOW WAS IN THE PROCESS OF
PIVOTING TO A NEUTRAL ORIENTATION...BEHIND A 100KT 250MB
SUBTROPICAL SPEED MAX ENTERING WEST TX FROM NORTHERN MEXICO. THE
UPPER LOW WILL EJECT INTO THE SOUTHERN PLAINS BY MIDDAY TUESDAY...WITH
STRONGLY DIFFLUENT FLOW DOWNSTREAM ACROSS THE MIDSOUTH.
GIVEN THE STRONG DYNAMICS...ABUNDANT MIDLEVEL MOISTURE AND
PERSISTENT SUBFREEZING TEMPS OVER NORTHEAST ARKANSAS...WINTRY
WEATHER APPEARS A GOOD BET. 12Z NAM SOUNDING SHOWED A REASONABLY
STRONG SIGNATURE FOR FREEZING RAIN NORTH OF JONESBORO MIDDAY
TUESDAY. THE SUBSEQUENT 18Z RUN DEPICTED A SOUNDING MORE FAVORABLE
FOR SLEET. IN ANY CASE...WITH THE 12Z NAM AND 12Z GFS BOTH DEVELOP
0.4 TO 0.6 INCHES OF LIQUID QPF ACROSS NORTHEAST ARKANSAS AND THE
WESTERN BOOTHEEL...WHERE TEMPS WILL REMAIN BELOW FREEZING THROUGH
THE DAY. WITH PREVIOUS ADVISORY LEVEL FORECASTED ICE AMOUNTS ALREADY
BUMPING UP TO WINTER STORM WARNING CRITERIA...HAVE UPGRADED
PORTIONS OF THE ADVISORY TO A WINTER STORM WARNING AND INCREASED
FORECAST ICE AMOUNTS SLIGHTLY. SIMILAR TO SUNDAY... NAM SOUNDINGS
SHOW DEEP CONVECTION MAY ROOT NEAR 750MB...RESULTING IN POCKETS OF
SMALL HAIL OVER THE ADVISORY AND WARNING AREA. GIVEN THE
HAIL/SLEET POTENTIAL...CURRENT THINKING IS THAT THE PROGGED 0.6
INCHES OF LIQUID EQUIVALENT WILL NOT BE ENTIRELY CONVERTED INTO
FREEZING RAIN...BUT THERE ARE BETTER THAN EVEN CHANCES OF
EXCEEDING A QUARTER INCH OF ICE.
FOR THE ADVISORY AREAS... TEMPS MAY REACH OR JUST EXCEED FREEZING
TUESDAY AFTERNOON... LIMITING ICE AND SLEET ACCUMULATIONS. GIVEN
HOW CLOSE THE THRESHOLDS WILL BE WITH THIS SYSTEM... THE ADVISORY
MAY BE ABLE TO BE PULLED EARLY...OR NEED TO BE EXTENDED EASTWARD
ACROSS NORTHERN WEST TN OF EXPECTED WARMING DOES NOT OCCUR. THE
EVENT SHOULD END WITH THE ARRIVAL OF A MIDLEVEL DRY SLOT LATE
TUESDAY AFTERNOON OR EARLY EVENING.
MIDWEEK PERIODS MAY SEE A FEW FLURRIES OR LIGHT SNOW SHOWERS...BUT
OTHERWISE QUIET AND COLD.
NEXT SYSTEM REMAINS ON TRACK FOR THE EARLY WEEKEND. ECMWF MODEL
HAS REMAINED CONSISTENT OVER THE PAST TWO DAYS AND WAS PREFERRED
FOR THE EXTENDED PERIODS. PRECIP CHANCES BEGIN TO RAMP UP FRIDAY
NIGHT...WITH MIXED MODE WINTRY PRECIP WE/VE BEEN ACCUSTOMED TO. BY
SATURDAY NIGHT... THE UPPER LOW AND DEFORMATION ZONE PASS OVER THE
MIDSOUTH... PERHAPS OFFERING MIDSOUTHERNERS THE BEST CHANCE OF
SNOW THUS FAR THIS WINTER.
PWB
&&
.AVIATION...
18Z TAF SET
LATEST RAP SHOWING IFR CONDITIONS CONTINUING AT KMEM...KMKL...AND
KTUP THROUGH THE NEXT 24 HOURS. LATEST SATELLITE IMAGES SHOW THE
BACK EDGE OF THE CLOUDS ACTUALLY BEGINNING TO REBUILD TO THE WEST
INSTEAD OF PUSHING EAST. EXPECT KJBR TO REMAIN VFR UNTIL 3-4Z
TONIGHT WHEN CONDITIONS WILL RETURN TO IFR. PRECIPITATION AHEAD OF
THE NEXT SYSTEM WILL SPREAD INTO KJBR...KMEM...AND KTUP AROUND
16Z. PRECIP SHOULD BEGIN AS FZRA OR PL AT KJBR BUT SHOULD CHANGE
OVER TO RA AROUND 18Z. FOR NOW WILL LEAVE FZRAPL MENTION THROUGH
END OF THIS TAF SET. KMEM SHOULD STAY ALL RA WHILE SOME TSRA COULD
OCCUR AT KTUP. NE WINDS BETWEEN 6-10 KTS WILL CONTINUE THROUGH
MUCH OF THE NEXT 24 HOURS. DIRECTION MAY CHANGE TO THE SE AFTER
12Z AT KTUP.
KRM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WINTER STORM WARNING FROM 9 AM TO 6 PM CST TUESDAY FOR CLAY-
CRAIGHEAD-GREENE-LAWRENCE-RANDOLPH.
WINTER WEATHER ADVISORY FROM 9 AM TO 6 PM CST TUESDAY FOR
MISSISSIPPI-POINSETT.
MO...WINTER STORM WARNING FROM 9 AM TO 6 PM CST TUESDAY FOR DUNKLIN.
WINTER WEATHER ADVISORY FROM 9 AM TO 6 PM CST TUESDAY FOR
PEMISCOT.
MS...NONE.
TN...WINTER WEATHER ADVISORY FROM 9 AM TO 6 PM CST TUESDAY FOR DYER-
LAKE-LAUDERDALE-OBION-TIPTON.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1109 AM CST MON FEB 3 2014
.DISCUSSION... /ISSUED 534 AM CST MON FEB 3 2014/
ANOTHER CHALLENGING FORECAST THIS UPDATE...JUST AS ONE WINTER
WEATHER ADVISORY IS EXPIRING ANOTHER ONE IS NEEDED.
MORNING TEMPERATURES RANGE FROM THE MID TEENS IN NORTHEAST
ARKANSAS TO THE MIDDLE 30S NEAR TUPELO. NORTH WIND CONTINUES TO
USHER COLDER AIR ACROSS THE AREA. A FEW SPRINKLES OR DRIZZLE WILL
REMAIN POSSIBLE IN WEST TENNESSEE AND NORTH MISSISSIPPI...MAINLY
NEAR THE ALABAMA STATE LINE AND TENNESSEE RIVER...FOR ANOTHER HOUR
OR TWO...BUT FOR THE MOST PART PRECIPITATION HAS COME TO AN END
ACROSS THE MIDSOUTH. SATELLITE AND METAR OBSERVATIONS SHOW AN
ABRUPT CLEARING LINE FROM NEAR BLYTHEVILLE TO NEAR FORREST CITY
SHIFTING TO THE EAST. MUCH OF THE MIDSOUTH WILL SEE SUNSHINE
TODAY...SOAK IT IN...BECAUSE IT MAY NOT MAKE ANOTHER APPEARANCE
THE REST OF THE WEEK...OR LONGER. HIGHS TODAY SHOULD RANGE FROM
NEAR FREEZING IN NORTHEAST ARKANSAS AND THE MISSOURI BOOTHEEL TO
NEAR 50 DEGREES IN NORTH MISSISSIPPI NEAR THE ALABAMA STATE LINE.
MOST AREAS WILL BE IN THE MID 30S TO MID 40S.
TONIGHT...A TROUGH WILL DEEPEN OVER THE SOUTHERN PLAINS AND WEST
TEXAS RESULTING IN SOUTHWEST FLOW ACROSS THE MIDSOUTH. A BROAD
130-140KT UPPER LEVEL JET WILL SHIFT EAST TOWARD THE MISSISSIPPI
RIVER VALLEY ENHANCING LIFT AND RESULTING IN WIDESPREAD RAIN
ACROSS EAST TEXAS SHIFTING TOWARD THE MIDSOUTH. TEMPERATURES WILL
FALL BELOW FREEZING...AS LOW AS THE MID 20S IN NORTHEAST ARKANSAS
AND RAIN SHOULD ARRIVE SHORTLY AFTER SUNRISE. MODEL SOUNDINGS
DIFFER CONSIDERABLY ALOFT...WITH THE NAM INDICATING A WARM LAYER
MUCH DEEPER AND WARMER THAN THE GFS. THE NAM WOULD DEFINITELY
INDICATE A FREEZING RAIN EVENT...WHILE THE GFS SHOWS WHAT COULD
BE A RAIN SLEET/SNOW MIX. DURING THE DAY...TEMPERATURES WILL
WARM...BUT MAY NOT RISE ABOVE FREEZING. CURRENT FORECAST HIGH IS
ONLY 32 DEGREES IN RANDOLPH COUNTY. HPC WWD GRAPHICS INDICATE 1
TENTH OF AN INCH OF FREEZING RAIN IS POSSIBLE AS FAR SOUTH AS
JONESBORO ARKANSAS WITH UP TO AROUND ONE QUARTER OF AN INCH
FARTHER NORTH. AS A STARTING POINT FOR THIS NEXT WINTER WEATHER
EVENT DECIDED TO ISSUE A WINTER WEATHER ADVISORY FOR LAKE COUNTY
TN...FAR NORTHWEST ARKANSAS AND THE MISSOURI BOOTHEEL. THIS AREA
MAY NEED TO BE EXPANDED AND OR EXTENDED OVER THE NEXT 24 HOURS.
PRECIPITATION SHOULD COME TO AN END FAIRLY QUICKLY AFTER SUNSET.
AGAIN AS A STARTING POINT...EXPECTING UP TO ONE QUARTER OF AN INCH
OF ICE OVERSPREAD BY 1-2 INCHES OF A MIXTURE OF SNOW/SLEET. THESE
TOTALS MAY NEED ADJUSTING AS THE EVENT DRAWS CLOSER.
WEDNESDAY AND THURSDAY LOOK COLD AND DRY...ALTHOUGH A FEW SNOW
SHOWERS MAY CREEP INTO NORTHEAST ARKANSAS THURSDAY AFTERNOON.
HIGHS WEDNESDAY SHOULD BE IN THE MID 30S TO MID 40S ACROSS MOST OF
THE AREA WITH THURSDAY MORNING LOWS RANGING FROM 13 TO 23 DEGREES.
HIGHS THURSDAY MIGHT NOT RISE ABOVE 25 DEGREES IN NORTHEAST
ARKANSAS...WHILE NORTHEAST MISSISSIPPI MIGHT MAKE IT INTO THE LOW
40S.
LATE IN THE WORK WEEK...FOCUS YOUR ATTENTION ON THE WESTERN GULF
OF MEXICO. THE GFS HAS BEEN CONSISTENT IN DEVELOPING A SURFACE
LOW IN THE WESTERN GULF AND TRACKING IT NORTHEAST SOMEWHERE ALONG
THE NORTHERN GULF COAST THEN INTO NORTHERN ALABAMA OR GEORGIA BY
SUNDAY. IF THIS SCENARIO PANS OUT...IT COULD BE A WINTRY MESS FOR
THE MIDSOUTH. THE ECMWF LAGS THE UPPER LEVEL SUPPORT FARTHER
WEST...THUS THE LOW DOESN`T DEEPEN NEARLY AS FAST NOR DEEP...AND
IT ALSO TAKES THE LOW FARTHER EAST RESULTING IN LESS IMPACT ACROSS
THE MIDSOUTH. CONFIDENCE IS LOW IN THE GFS SOLUTION...BUT WILL
MAINTAIN CHANCE POPS WITH SNOW ACROSS THE MAJORITY OF THE
MIDSOUTH.
&&
.AVIATION...
18Z TAF SET
LATEST RAP SHOWING IFR CONDITIONS CONTINUING AT KMEM...KMKL...AND
KTUP THROUGH THE NEXT 24 HOURS. LATEST SATELLITE IMAGES SHOW THE
BACK EDGE OF THE CLOUDS ACTUALLY BEGINNING TO REBUILD TO THE WEST
INSTEAD OF PUSHING EAST. EXPECT KJBR TO REMAIN VFR UNTIL 3-4Z
TONIGHT WHEN CONDITIONS WILL RETURN TO IFR. PRECIPITATION AHEAD OF
THE NEXT SYSTEM WILL SPREAD INTO KJBR...KMEM...AND KTUP AROUND
16Z. PRECIP SHOULD BEGIN AS FZRA OR PL AT KJBR BUT SHOULD CHANGE
OVER TO RA AROUND 18Z. FOR NOW WILL LEAVE FZRAPL MENTION THROUGH
END OF THIS TAF SET. KMEM SHOULD STAY ALL RA WHILE SOME TSRA COULD
OCCUR AT KTUP. NE WINDS BETWEEN 6-10 KTS WILL CONTINUE THROUGH
MUCH OF THE NEXT 24 HOURS. DIRECTION MAY CHANGE TO THE SE AFTER
12Z AT KTUP.
KRM
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 35 30 41 30 / 0 10 100 70
MKL 32 29 41 31 / 0 10 100 80
JBR 28 25 33 27 / 0 10 100 40
TUP 39 36 52 37 / 0 10 100 90
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST TUESDAY FOR CLAY-
CRAIGHEAD-GREENE-LAWRENCE-RANDOLPH.
MO...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST TUESDAY FOR
DUNKLIN-PEMISCOT.
MS...NONE.
TN...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST TUESDAY FOR LAKE.
&&
$$
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 MILWAUKEE/SULLIVAN WI
321 PM CST MON FEB 3 2014
.SHORT TERM...
.TONIGHT AND TUESDAY...FORECAST CONFIDENCE IS HIGH.
SHORT TERM MODELS AGREE WITH HIGH PRESSURE GRADUALLY SLIDING EAST OF
THE REGION DURING THIS PERIOD. THE HIGH WILL BRING QUIET WEATHER
TONIGHT INTO TUESDAY MORNING. LIGHT AND VARIABLE TO CALM WINDS ARE
EXPECTED TONIGHT INTO EARLY TUESDAY. MIDDLE TO HIGH CLOUDS WILL
GRADUALLY SPREAD NORTHEASTWARD INTO THE AREA THIS EVENING INTO
TUESDAY MORNING...BECOMING OVERCAST BY MIDDAY TUESDAY.
STRONG INVERSTION JUST ABOVE THE SURFACE SEEN ON RAP FORECAST
SOUNDINGS LATER TONIGHT...LESS SO ON THE NAM AND GFS. RADIATIONAL
COOLING COULD CAUSE TEMPERATURES THIS EVENING TO DROP
QUICKLY...BEFORE MORE BROKEN TO OVERCAST CLOUDS MOVE IN LATER
TONIGHT AND TUESDAY MORNING.
WENT COOLER THAN THE CONSENSUS SHORT TERM MODELS FOR LOWS
TONIGHT...MAINLY IN THE ZERO TO 5 ABOVE ZERO RANGE. BROUGHT HIGHS
INTO THE LOWER 20S TUESDAY...AHEAD OF NEXT SYSTEM MOVING TOWARD THE
AREA.
KEPT MAINLY CHANCE POPS GOING FOR TUESDAY AFTERNOON IN THE
SOUTH...LOWER TO THE NORTH...WITH PUSH OF MODEST MID LEVEL
FRONTOGENESIS RESPONSE AND STRONG Q VECTOR CONVERGENCE. AREA
FORECAST SOUNDINGS FROM GFS AND TIME HEIGHT CROSS SECTIONS INDICATE
DRY AIR IN THE LOW LEVELS SLOWLY SATURATING BY 00Z WEDNESDAY...WHICH
COULD DELAY THE START TIME OF THE SNOW IN THE SOUTH. IT APPREAS THAT
MOST OF THE SNOW SHOULD HOLD OFF UNTIL THE EVENING.
.TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM.
SOUTHEAST WISCONSIN IS IN THE RIGHT ENTRANCE REGION
AHEAD OF THE EJECTING SHORTWAVE AND STRENGTHENING UPPER JET FROM
AROUND 185 KNOTS JUST NORTHEAST OF LAKE HURON TUESDAY EVENING.
THIS RESULTS IN WEAK TO MODERATE UPWARD DURING THE EVENING...WITH
WEAK UPWARD MOTION INTO WEDNESDAY MORNING.
THE UPPER DYNAMICS APPEARS TO BE THE REASON FOR THE ENHANCED
PRECIPITATION OF THE MODELS SO FAR NORTH OF THE LOW TRACK. THE
12Z NAM/GFS AND 00Z ECMWF BRINGS A LOW FROM ARKANSAS
TUESDAY...STRENGTHENING IT AS IT MOVES ACROSS THE OHIO RIVER AREA
TUESDAY EVENING BEFORE REACHING JUST EAST OF LAKE EIRE WEDNESDAY
MORNING.
GIVEN THE UPPER JET DYNAMICS EVEN THE GFS AND ECMWF HAVE A WIDE
AREA OF MODERATE SNOW REACHING SOUTHERN...AND ESPECIALLY SOUTHEAST
WISCONSIN TUESDAY NIGHT WITH THE 00Z ECMWF LINGERING THE SNOW
LONGER ACROSS SOUTHERN WISCONSIN INTO WEDNESDAY MORNING.
24 HOUR NAM QPF VALUES ARE AROUND 0.20 FROM LONE ROCK TO
SHEBOYGAN TO 0.32 OVER RACINE AND KENOSHA. THERE IS SOME LAKE
ENHANCMENT FROM MILWAUKEE SOUTH TO KENOSHA AND ACROSS WALWORTH
COUNTY. THE 00Z ECMWF AND 12Z GFS IS AROUND HALF THE QPF FROM THE
NAM.
WITH RATHER HIGH SNOW TO LIQUID RATIOS OF AROUND 15 TO 1...
SEVERAL INCHES OF SNOW IS LIKELY...AND ADVISORIES FOR SNOW
WOULD BE NEEDED OVER THE FAR SOUTHEAST. FOR NOW WILL GO WITH A
CONSENSUS OF QPF AND SNOW AMOUNTS.
THE SHORTWAVE REACHES A CONFLUENT UPPER FLOW THAT FLATTENS AND
WEAKENS THE SHORTWAVE AS IT REACHES THE EASTERN GREAT LAKES BY
WEDNESDAY MORNING.
700 MB LAYERS DO NOT DRY MUCH WEDNESDAY ALTHOUGH THE 850 MB LAYER
DOES. 950 MB RH IS RATHER HIGH SOUTHEAST THROUGH WEDNESDAY MORNING
DUE TO A NORTHEAST FLOW OFF LAKE MICHIGAN. NAM FORECAST SOUNDINGS
CUT OFF THE LAKE EFFECT SNOW POTENTIAL BY NOON AS THE 850 MB DRIESAND
INVERSION HEIGHTS LOWER.
.WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE IS HIGH.
THE MID/UPPER LEVEL FLOW BECOMES MORE ZONAL WITH A WEAK SHORTWAVE
MOVING ACROSS WISCONSIN LATE WEDNESDAY NIGHT AND THURSDAY
MORNING.
AS THE SHORTWAVE MOVES EAST THURSDAY AFTERNOON THE 700 MB RH
DECREASES.
HIGH PRESSURE BUILDS ACROSS THE MID MISSISSIPPI VALLEY FOR
ANOTHER COLD PERIOD. WIND CHILLS MAY REACH ADVISORY CRITERIA LATE
WEDNESDAY NIGHT AND THURSDAY MORNING.
.LONG TERM...
.FRIDAY AND SATURDAY...FORECAST CONFIDENCE IS MEDIUM.
THE MID/UPPER LEVEL FLOW BECOMES MORE SOUTHWEST AS ANOTHER TROUGH
DROPS INTO THE WESTERN U.S. FRIDAY AND EJECTS EAST/NORTHEAST INTO
THE SOUTHERN PLAINS ON THE 00Z ECMWF SATURDAY. THE 12Z GFS AND 06Z
DGEX IS SLOWER THAN THE 00Z ECMWF.
THE GFS/DGEX AND 00Z ECMWF ARE ALL DRY ACROSS SOUTHERN
WISCONSIN WITH HIGH PRESSURE OVER THE NORTHERN PLAINS AND GREAT
LAKES.
.SUNDAY AND MONDAY...FORECAST CONFIDENCE IS MEDIUM.
THE GFS AND DGEX ARE SLOWER BRINGING THE STRONG SHORTWAVE ACROSS
THE LOWER AND MID MISSISSIPPI VALLEY...AND NOW DO NOT CLOSE OFF
THE UPPER TROUGH.
THE 12Z GFS IS STILL THE FARTHEST NORTH WITH THE SURFACE LOW
TRACK...WITH A DOUBLE LOW STRUCTURE THAT HAS A SECOND LOW THAT
MOVES ACROSS TENNESSEE AND EASTERN KENTUCKY SUNDAY...WHILE THE
00Z ECMWF HAS A LOW MOVING UP THE EAST COAST OF THE U.S. THE 06Z
DGEX IN IN BETWEEN...BUT EVEN THE NORTHERN GFS ONLY BRUSHES THE
KENOSHA AREA WITH LIGHT SNOW.
HIGH PRESSURE THEN BUILDS INTO THE UPPER MISSISSIPPI VALLEY
MONDAY...CONTINUING THE COLD TEMPERATURES.
&&
.AVIATION/00Z TAFS/...
VFR CONDITIONS ARE EXPECTED TONIGHT AND TUESDAY. HIGH PRESSURE WILL
GRADUALLY MOVE EAST OF THE REGION DURING THIS TIME. MIDDLE TO HIGH
CLOUDS WILL GRADUALLY MOVE NORTHEASTWARD INTO THE AREA THIS EVENING
INTO TUESDAY MORNING...WITH OVERCAST CEILINGS GRADUALLY LOWERING
DURING THE AFTERNOON.
LIGHT AND VARIABLE WINDS TONIGHT WILL BECOME NORTHEAST BY TUESDAY
AFTERNOON...GRADUALLY INCREASING IN SPEED LATE IN THE DAY. ANY SNOW
WITH THE LOW PRESSURE SYSTEM PASSING WELL SOUTH OF THE AREA SHOULD
HOLD OFF UNTIL AFTER 00Z WEDNESDAY.
&&
.MARINE...
WINDS AND WAVES MAY REACH SMALL CRAFT ADVISORY LEVELS TUESDAY NIGHT
AND WEDNESDAY...AS A TIGHT PRESSURE GRADIENT DEVELOPS WITH PASSING
LOW PRESSURE TO THE SOUTH OF THE REGION. NORTHEAST WINDS TUESDAY
NIGHT INTO EARLY WEDNESDAY SHOULD BRING HIGH WAVES NEAR THE SHORE IN
ICE FREE AREAS...ALONG WITH THE POTENTIAL FOR MODERATE FREEZING
SPRAY. GUSTS TO 30 KNOTS ARE POSSIBLE DURING THIS TIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...WOOD
TUESDAY NIGHT THROUGH MONDAY...HENTZ