Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/08/14
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
820 PM MST FRI FEB 7 2014
.SYNOPSIS...
STRONG HIGH PRESSURE WILL BUILD INTO THE REGION THIS WEEKEND WITH
MUCH WARMER CONDITIONS BY EARLY NEXT WEEK. THESE ABNORMALLY WARM AND
DRY CONDITIONS SHOULD PREVAIL THROUGH ALL OF NEXT WEEK.
&&
.DISCUSSION...
DRY NORTHWEST FLOW ALOFT...WITH WARMER DAYS THROUGH THE WEEKEND...
REPLETE WITH VARIABLE HIGH CLOUDS ARE FORECAST. CURRENT FORECASTS
LOOK GOOD. NO UPDATES. PREVIOUS DISCUSSION BELOW STILL APPLIES.
PREVIOUS DISCUSSION...230 PM MST...
STRONG JET STREAK ALONG THE WEST COAST IS PRODUCING WIDESPREAD
BENEFICIAL RAIN ACROSS THE DROUGHT-STRICKEN AREAS OF NORTHERN AND
CENTRAL CA. FURTHER SOUTHEAST ACROSS THE DESERT SOUTHWEST...SHARP
HEIGHT RISES HAVE BEEN OBSERVED WITH CIRRUS SPILLING OVER THE
BUILDING EASTERN PACIFIC RIDGE. LEFTOVER LOW-LEVEL MOISTURE IN THE
WAKE OF THE SHORT-WAVE TROUGH NOW LOCATED IN TX IS ALSO LEADING TO
THE DEVELOPMENT OF BACK-BUILDING CU FROM THE MOGOLLON RIM INTO THE
LOWER DESERTS. HOWEVER...VERTICAL MOTION IS GENERALLY SUBSIDENT AND
RADAR IMAGERY SHOWS LITTLE IN THE WAY OF PRECIPITATION. HI-RES
GUIDANCE INCLUDING THE LATEST HRRR INDICATES NO POTENTIAL FOR
ADDITIONAL PRECIPITATION THROUGH THIS EVENING AND POPS REMAIN NEAR 0
PERCENT.
&&
.PREVIOUS DISCUSSION...433 AM MST...
FLAT RIDGING AND QUASI-ZONAL FLOW WILL PREDOMINATE OVER THE REGION
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. H5 HEIGHTS WILL BE
CHARACTERIZED BETWEEN 576DM AND 582DM WITH H8 TEMPERATURES REACHING
TOWARDS A +12C TO +15C RANGE. THIS COMBINATION NEARLY MIRRORS
CONDITIONS EXPERIENCED DURING THE MIDDLE/END OF JANUARY...AND
CONFIDENCE IS HIGH THAT ABOVE NORMAL TEMPERATURES WILL PREVAIL.
MODELS ARE IN FAIR AGREEMENT SHOWING ANOTHER FAST MOVING WAVE
AMPLIFYING NEAR THE FORECAST AREA LATE MONDAY INTO TUESDAY...WITH
THE 00Z ECMWF SLIGHTLY FASTER AND MORE DEFINED IN THE WAVE
STRUCTURE. REGARDLESS...IMPACTS SHOULD PRIMARILY BE LIMITED TO
NORTHERN ARIZONA IN THE FORM OF SCT SHOWERS...WITH ONLY AN INCREASED
PRESSURE GRADIENT PROVIDING THE SETUP FOR SOMEWHAT BREEZY CONDITIONS
(THOUGH NOTHING UNSEASONABLY STRONG).
THEREAFTER...CONTINUED RIDGING AND BROAD WNW FLOW WILL PREVAIL FOR
THE REMAINDER OF THE WEEK. ENSEMBLE SPREAD IS UNUSUALLY LOW
CONSIDERING THE WINTER SEASON WITH H5 HEIGHTS NOT FAR FROM 580DM
THROUGHOUT THE LATTER HALF OF NEXT WEEK. H8 TEMPERATURES SHOULD PUSH
ABOVE THE +15C MARK...WITH AFTERNOON 1000-850MB THICKNESS VALUES
ECLIPSING 139DM. CONFIDENCE IS VERY HIGH THAT AFTERNOON HIGHS WILL
REACH OR EXCEED 5F-10F ABOVE NORMAL FROM WEDNESDAY AND BEYOND...WITH
MANY LOWER ELEVATION LOCATIONS EXCEEDING THE 80F THRESHOLD BY THE
END OF THE WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
THROUGH 20Z SAT...VARIABLE HIGH CLOUDS AOA 20 THSD MSL. LIGHT WIND
UNDER 7 KNOTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
HIGH PRESSURE WILL BUILD INTO THE REGION OVER THE NEXT COUPLE
DAYS...BUT HUMIDITIES WILL REMAIN ELEVATED THROUGH THE WEEKEND. THE
ELEVATED MOISTURE LEVELS WILL REMAIN UNTIL DRIER AIR FOLLOWS AFTER A
WEAK TROUGH FORECAST TO MOVE THROUGH ON MONDAY. NOT EXPECTING MUCH
IN THE WAY OF PRECIP WITH THIS TROUGH...BUT THERE SHOULD BE SOME
BREEZY WINDS...ESPECIALLY DOWN THE CO RIVER MONDAY AFTERNOON.
MINIMUM HUMIDITIES WILL DECREASE INTO THE TEENS AFTER MONDAY WHILE
TEMPERATURES RISE TO WELL ABOVE SEASONAL NORMALS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...VASQUEZ
PREVIOUS DISCUSSION...HIRSCH
PREVIOUS TO PREVIOUS DISCUSSION...MO
AVIATION...VASQUEZ
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1020 AM PST Thu Feb 6 2014
.Synopsis...
Series of moist Pacific storms will impact Interior Northern
California today through early next week bringing rain...snow in
the mountains...and breezy to windy conditions at times.
&&
.Discussion...
First wave of precip in Norcal has virtually moved south of our CWA
as vort max off the central CA coast drops SEwd to off the Socal
coast by 00z Fri. Updated the zones earlier this morning to account
for a weaker short wave and area of showers expected to move through
the Nrn portion of the CWA this afternoon...mainly affecting the
coastal mtns and Nrn zones including the Nrn Sac Vly. This feature
is between the 2 larger scale waves...the one to our SW and the
other rotating around the Rex low over the Pac NW.
This system will wind down tonite and there will be a break in the
wx. Then on Fri and into the weekend the much wetter and warmer wx
system will impact Norcal. The main TPW plume around 150-160W will
advect NEwd as energy rotates around the base of the central Pac
trof and the Pacific jet moves into Norcal. WAA precip will rapidly
develop over Norcal on Fri with The amplification of the ridge and
jet shifting the plume gradually Nwd on Sat. With the influx of
subtropical air...snow levels will rise so the initial warning for
the Siernev around 5 kft will need to be tweaked to higher snow
levels during the weekend. Snow levels could rise to near or above
the major passes on I-80/Hwy 50 during the late Sat early Sun time
frame. In advance of this...the main impact will be Fri afternoon
and Fri nite with the lower snow levels and focus of the plume over
the 80/50 corridor. Thus...we are contemplating upgrading the watch
to a warning by the afternoon package. A gradual drop in snow levels
to below pass level is likely on Sun as the jet sags Swd again. Main
changes to forecasts will be to QPF and snow levels...and we are
also contemplating winds Fri afternoon into Sat morning in the
valley as Sly upvalley flow increases in the warm sector.
JHM
Satellite imagery showing short wave trough rotating around large
scale polar low and across the CWA this morning with light to
moderate returns on Mosaic base reflectivity. Rainfall amounts
generally around around a third of an inch or less in the
Sacramento Valley overnight with lighter amounts to the north.
Light snow has been observed in the Shasta mountains and Coastal
range and in the Sierra Nevada. Snow levels currently around 2000
to 3000 feet. System on satellite appears to be moving faster than
06z progs are showing and latest HRRR suggesting precip will be
decreasing by late morning into early afternoon with lingering
showers...mainly over southern portions of the forecast area where
dynamics and moisture are better focused.
Light shower threat looks to continue tonight...mainly over the
mountains...then large atmospheric river extending from the
tropics takes aim on NorCal. WAA precip and large scale
isentropic lift increases over western portions of the CWA Friday
morning then spreads over the entire CWA during the day. Models
indicating periods of moderate to heavy precip Friday night
through the weekend as the concentrated moisture plume slowly sags
southward through Interior NorCal. Low snow levels in the
foothills will continue Friday morning but will gradually
rise to above 6000 feet by Saturday evening and near pass levels
Sunday into Monday. Winter storm watch has been expanded to
include the Coastal mountains for Friday into Saturday. Models
continue to showing significantly different QPF totals through the
weekend with oper GFS indicating upwards of 6 to 7 inches of
liquid precip in the Sierra while the ECMWF-HiRes is a little less
than half that amount. QPFs are in better agreement in the Central
Valley where upwards of 1 to 3 inches likely.
PCH
.Extended Discussion (Monday through Thursday)
Precipitation tapers off on Monday as temporary upper ridging
slides over the west coast. ECMWF a little slower clearing out
last in series of weekend systems so left in slight threat pops on
Monday with highest pops over Sierra closest to departing system.
Extended models all flatten west coast ridge quickly next Tuesday
as next Pacific frontal system pushes into the Pacific Northwest
bringing slight chances of precipitation to the northern most
portions of the state. Relatively flat ridging over the west coast
will allow a couple more slightly stronger Pacific systems to move
into the region Wednesday and Thursday. Precipitation amounts
will be limited due to general ridging over the area but most of
CWA will see a threat of precipitation. Despite cloud cover and
occasional precipitation...Daytime highs throughout the extended
period are expected to remain several degrees above normal with
moderate to high snow levels under moderately warm airmass.
&&
.Aviation...
Frontal system has shifted into central California with scattered
showers expected to continue across NorCal through this afternoon.
Primarily VFR/MVFR, but local IFR ceilings possible in heavier
showers. Generally IFR/LIFR conditions for mountains the next 24
hours, with snow levels down to 2500 to 3500 ft. Mainly south winds
10 to 15 knots for the lower elevations, with southwest wind gusts
to 40 knots over higher terrain. Shen
&&
.STO Watches/Warnings/Advisories...
Winter Storm Watch from Friday afternoon through Saturday evening
above 5000 feet in the west slope Northern Sierra Nevada...Western
Plumas county/Lassen park.
Winter Weather Advisory until 10 pm pst this evening above 4000
feet in the west slope Northern Sierra Nevada.
Winter Storm Watch from Friday afternoon through Saturday
afternoon above 4000 feet in the mountains southwestern Shasta
county to northern Lake county.
Winter Storm Watch from Friday afternoon through Saturday evening
for Shasta Lake area/Western Shasta county.
&&
$$
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
431 AM PST Thu Feb 6 2014
.Synopsis...
Series of moist Pacific storms will impact Interior Northern
California today through early next week bringing rain...snow in
the mountains...and breezy to windy conditions at times.
&&
.Discussion...
Satellite imagery showing short wave trough rotating around large
scale polar low and across the CWA this morning with light to
moderate returns on Mosaic base reflectivity. Rainfall amounts
generally around around a third of an inch or less in the
Sacramento Valley overnight with lighter amounts to the north.
Light snow has been observed in the Shasta mountains and Coastal
range and in the Sierra Nevada. Snow levels currently around 2000
to 3000 feet. System on satellite appears to be moving faster than
06z progs are showing and latest HRRR suggesting precip will be
decreasing by late morning into early afternoon with lingering
showers...mainly over southern portions of the forecast area where
dynamics and moisture are better focused.
Light shower threat looks to continue tonight...mainly over the
mountains...then large atmospheric river extending from the
tropics takes aim on NorCal. WAA precip and large scale
isentropic lift increases over western portions of the CWA Friday
morning then spreads over the entire CWA during the day. Models
indicating periods of moderate to heavy precip Friday night
through the weekend as the concentrated moisture plume slowly sags
southward through Interior NorCal. Low snow levels in the
foothills will continue Friday morning but will gradually
rise to above 6000 feet by Saturday evening and near pass levels
Sunday into Monday. Winter storm watch has been expanded to
include the Coastal mountains for Friday into Saturday. Models
continue to showing significantly different QPF totals through the
weekend with oper GFS indicating upwards of 6 to 7 inches of
liquid precip in the Sierra while the ECMWF-HiRes is a little less
than half that amount. QPFs are in better agreement in the Central
Valley where upwards of 1 to 2 inches likely.
PCH
.Extended Discussion (Monday through Thursday)
Precipitation tapers off on Monday as temporary upper ridging
slides over the west coast. ECMWF a little slower clearing out
last in series of weekend systems so left in slight threat pops on
Monday with highest pops over Sierra closest to departing system.
Extended models all flatten west coast ridge quickly next Tuesday
as next Pacific frontal system pushes into the Pacific Northwest
bringing slight chances of precipitation to the northern most
portions of the state. Relatively flat ridging over the west coast
will allow a couple more slightly stronger Pacific systems to move
into the region Wednesday and Thursday. Precipitation amounts
will be limited due to general ridging over the area but most of
CWA will see a threat of precipitation. Despite cloud cover and
occasional precipitation...Daytime highs throughout the extended
period are expected to remain several degrees above normal with
moderate to high snow levels under moderately warm airmass.
&&
.Aviation...
Frontal passage through northern California today will bring MVFR/IFR
ceilings and visibility in light rain to the valley with IFR
conditions at the higher elevations in rain and snow. Snow levels
2500 to 3500 feet. Secondary shortwave trough will bring MVFR most
areas overnight with light rain/snow mainly north of interstate
80. Mainly south winds to 15 knots lower elevations with gusts to
40 knots highest elevations.
&&
.STO Watches/Warnings/Advisories...
Winter Storm Watch from Friday afternoon through Saturday evening
above 5000 feet in the west slope Northern Sierra Nevada...Western
Plumas county/Lassen park.
Winter Weather Advisory until 10 pm pst this evening above 4000
feet in the west slope Northern Sierra Nevada.
Winter Storm Watch from Friday afternoon through Saturday
afternoon above 4000 feet in the mountains southwestern Shasta
county to northern Lake county.
Winter Storm Watch from Friday afternoon through Saturday evening
for Shasta Lake area/Western Shasta county.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
817 PM PST WED FEB 5 2014
.UPDATE...
NOT PLANNING ON ANY CHANGES THIS EVENING. THE 00Z NAM AND LATEST
3KM HRRR SUGGEST TRACK OF SHORTWAVE FURTHER SOUTH LATE TONIGHT AND
THURSDAY WITH THE GFS MAINTAINING A GENERALLY SOUTH OF HIGHWAY 50
LINE FOR THE BULK OF PRECIPITATION. SO AMOUNTS FOR THE TAHOE BASIN
MAY BE HEAVIEST ON THE SOUTH END TOWARD ALPINE COUNTY. WILL WAIT
FOR THE 00Z ECMWF TO DETERMINE IF THIS MORE SOUTHERN TRACK IS
REASONABLE AND LET THE NIGHT SHIFT MAKE NECESSARY ADJUSTMENTS
WITH THE MORNING FORECAST. MODELS ARE SHOWING A DEFINITE DECREASE
IN COVERAGE BY LATE AFTERNOON. SO THE ADVISORIES ARE PROBABLY TOO
LONG ALTHOUGH SLICK ROADS WILL PERSIST INTO THURSDAY NIGHT WHERE
NOT TREATED. AS COLD AS THINGS ARE, ANY SNOW THAT FALLS WILL
RESULT IN HAZARDOUS ROADS DURING THE THURSDAY MORNING COMMUTE
INCLUDING LOWER VALLEYS. FOR LOWER VALLEYS, CONFIDENCE IN AT LEAST
AN INCH OF SNOW IS ONLY LOW-MEDIUM FOR THE RENO AREA AND NORTH
VALLEYS WITH MEDIUM CONFIDENCE IN THE CARSON CITY-DAYTON AREA OF
HIGHWAY 50, AND HIGH SOUTH OF CARSON CITY ALONG THE HIGHWAY 395
CORRIDOR.
QUICK LOOK BEYOND THURSDAY STILL SUGGESTS A VERY AND WET WARM
SYSTEM WITH GUSTY WINDS. SO AS FAR AS THE 00Z GFS/NAM
DETERMINISTIC RUNS, THE FORECAST IS ON TRACK WITH THE TYPICAL
UNCERTAINTY IN SNOW LEVELS. HOHMANN
&&
.PREVIOUS DISCUSSION... /ISSUED 313 PM PST WED FEB 5 2014/
SYNOPSIS...
INCREASING MOISTURE AND A WEAK DISTURBANCE MOVING OVER THE SIERRA
AND WESTERN NEVADA WILL BRING SOME SNOW THURSDAY. DEEPER PACIFIC
MOISTURE WILL BRING MILDER TEMPERATURES AND PERIODS OF RAIN AND
SNOW TO THE REGION THIS WEEKEND ALONG WITH GUSTY WINDS. DRIER
WEATHER IS EXPECTED NEXT WEEK.
SHORT TERM...
ACTIVE WEATHER PATTERN FOR THE NEXT FEW DAYS BEGINNING TOMORROW.
THE MODELS CONTINUE TO SHOW DISCREPANCIES BETWEEN ONE ANOTHER AS
WELL AS RUN TO RUN EVEN FOR TOMORROW. THERE IS ENOUGH AGREEMENT
THAT WE FEEL CONFIDENT THERE WILL BE SNOW IN THE SIERRA AND
POSSIBLY WESTERN NEVADA TOMORROW. ALSO, THE STORM SLATED FOR THE
WEEKEND IS TRENDING WETTER ON THE MODELS AS WELL.
EXPECT INCREASING CLOUDS TONIGHT AHEAD OF A WEAK PACIFIC SYSTEM
FOR TOMORROW. THE TRACK IS THE BIGGEST HEADACHE THIS AFTERNOON AS
THE GFS IS THE FURTHEST SOUTH AND THE EC THE FURTHEST NORTH. HAVE
USED THE SREF WHICH IS IN BETWEEN AND STILL SHOWS A DECENT CHANCE
OF SNOW FROM I-80 SOUTH FOR TOMORROW. SNOW SHOULD BEGIN AROUND 12Z
IN THE SIERRA FOR THE TAHOE BASIN SOUTH TO MONO COUNTY AND
CONTINUE THROUGH THE AFTERNOON. SOME PERIODS OF LIGHT SNOW WILL
ALSO OCCUR IN WRN NEVADA DURING THE LATE MORNING AND AFTERNOON
SOUTH OF I-80 WITH LIGHTER SHOWERS POSSIBLE NORTH. MODELS AGREE ON
QPF AROUND 1/2 INCH IN THE SIERRA WITH SNOW RATIOS OF 12-15:1, SO
HOISTED A LOW-MODERATE ADVISORY WITH A FEW INCHES AROUND 6000 FEET
AND UP TO 10 INCHES ABOVE 7,000. AMOUNTS IN WRN NEVADA WILL BE
LESS THAN 2 INCHES, AND WITH THE SNOW BEING LIGHT, EXPECT LITTLE
IMPACT TO ROADS BELOW 5,000 FEET EVEN THOUGH SNOW LEVELS WILL BE
NEAR THE VALLEY FLOORS.
SNOW TO END EARLY THURSDAY EVENING WITH A BRIEF BREAK BEFORE THE
NEXT SYSTEM MOVES IN FRIDAY AFTERNOON. THIS NEXT SYSTEM HAS A GOOD
SUBTROPICAL MOISTURE TAP ON ALL THE MODELS WITH PW APPROACHING 1.5
INCHES ALONG THE COAST BY FRIDAY AFTERNOON. WHILE THE JET IS
PROGGED TO BE TO THE NORTH, AND ITS FORCING WOULD NOT BE FAVORABLE,
A STRONG WARM FRONT WILL MOVE THROUGH. ITS ISENTROPIC LIFT AND
STRONG SW UPSLOPE FLOW WILL PROVIDE GOOD FORCING FOR THE SIERRA.
SNOW LEVELS WILL BE TRICKY INTO FRIDAY NIGHT AND POSSIBLY START
OUT BELOW 5000 FEET BEFORE RISING OVERNIGHT. THE GFS KEEPS SNOW
LEVELS LOWER LONGER WHILE THE NAM RAISES THEM FASTER. IN ADDITION,
STRONG WINDS ARE POSSIBLE NEAR AND EAST OF HIGHWAY 395 WITH THIS
SYSTEM. THE NAM IS STRONGER WITH THE WINDS AS WELL WITH MORE
SHADOWING INTO WESTERN NEVADA. WITH LACK OF A SURFACE HIGH OVER
THE GREAT BASIN AND NEAR NORMAL HIGHS FRIDAY AFTERNOON, I AM
LEANING TOWARD THE NAM IDEAS. THE LACK OF A SURFACE HIGH WILL
LIMIT ANY COLD AIR DAMMING AND ALSO RESULT AND A MORE FAVORABLE
PROFILE FOR WINDS.
WHILE RAIN AND SNOW WILL OCCUR IN THE SIERRA, THE WARMER SOLUTIONS
WILL KEEP MOST ACCUMULATING SNOW ABOVE 7000 FEET SO WILL HOLD OFF
ON ANY WATCHES AT THIS TIME. AS FOR WINDS, THE BEST POTENTIAL FOR
STRONG WINDS IS ALONG THE SIERRA FRONT INTO MONO COUNTY. WHILE THE
INCREASING WINDS ALOFT ON THE NAM UPSTREAM FAVOR TRAPPED LEE
WAVES, 700 MB WINDS OF 60-70 KTS WOULD BE STRONG ENOUGH FOR SOME
GUSTS OVER 60 MPH. ISSUED HIGH WIND WATCH FOR THOSE AREAS AS I AM
CONFIDENT WE WILL SEE AT LEAST ADVISORY LEVEL WINDS. ELSEWHERE,
IT WILL BE WINDY AS WELL BUT ONLY ADVISORY LEVEL WINDS LOOK TO
OCCUR AND WILL HANDLE THAT CLOSER TO THE EVENT. ONE OTHER THING TO
MENTION IS THAT EVEN IF A BIT MORE SPILLOVER OCCURS THAN EXPECTED,
SFC GRADIENT WILL ALSO BE SUPPORTIVE ENOUGH FOR GUSTY WINDS
ACCOMPANIED BY THE RAIN AND/OR SNOW.
A BRIEFING ON THE SERIES OF STORMS WHICH SUMMARIZES THIS
INFORMATION CAN BE FOUND ON OUR WEB PAGE AND YOU TUBE CHANNEL.
WALLMANN
LONG TERM...SATURDAY THROUGH WEDNESDAY...
FOR SATURDAY THROUGH EARLY MONDAY MORNING ATTENTION TURNS TO A
SUBTROPICAL MOISTURE PLUME EXTENDING FROM HAWAII INTO THE WEST
COAST. A MODEST PLUME OF ABOUT 1.25 INCHES WILL EXTEND OVER THE BAY
AREA BEGINNING EARLY SATURDAY AND PERSISTS UNTIL LATE SUNDAY INTO
EARLY MONDAY MORNING. THIS IS SHAPING OUT TO BE ANOTHER WARM SYSTEM
WITH AMPLE MOISTURE BUT WILL FEATURE HIGH SNOW LEVELS THAT WILL
RAPIDLY INCREASE ON SATURDAY TO BETWEEN ABOUT 7,000-8,000 FEET.
FORCING WILL ALSO BE AN ISSUE WITH THIS SYSTEM WITH JET DYNAMICS
REMAINING NORTH ACROSS OREGON AND STRONG FRONTOGENESIS FORCING
REMAINING ABSENT. MAIN MECHANISM WILL BE OROGRAPHIC LIFT ACROSS THE
SIERRA AND MODEST ISENTROPIC LIFT. THIS SHOULD YIELD THE HIGHEST
PRECIPITATION AMOUNTS ON THE WINDWARD SLOPES OF THE SIERRA AND ALONG
THE CREST. STILL COULD SEE SOME HEALTHY LIQUID EQUIVALENT PRECIP
ALONG THE CREST WITH MODELS DEPICTING GENERALLY BETWEEN 2-3 INCHES
OF LIQUID FOR A 48 HOUR PERIOD FROM SATURDAY INTO EARLY MONDAY
MORNING. THIS COULD YIELD OVER 2 FEET OF SNOWFALL FOR HIGHER SIERRA
TERRAIN WITH MAINLY A RAIN EVENT FOR LOWER ELEVATIONS. SNOWFALL
AMOUNTS BELOW 8,000 FEET IS LOW CONFIDENCE DUE TO UNCERTAINTIES WITH
SNOW LEVEL PLACEMENT AT THIS POINT.
RECENT RUNS CONCENTRATE THE BULK OF THE MOISTURE ACROSS FROM THE
TAHOE BASIN NORTH INTO LASSEN COUNTY WITH LESSER AMOUNTS ACROSS MONO
COUNTY. GENERALLY EXPECTING ABOUT 1-1.5 INCHES OF LIQUID EQUIVALENT
ACROSS THE CREST IN MONO COUNTY. EXPECT MUCH OF WESTERN NEVADA TO BE
SHADOWED THROUGH THE WEEKEND WITH MAINLY INTERMITTENT SHOWERS BLOWING
ACROSS THE SIERRA WITH STRONG AND GUSTY WINDS PERSISTING THROUGH
SATURDAY. EXPECTING THE BEST CHANCE OF SPILLOVER PRECIPITATION TO
OCCUR SUNDAY NIGHT INTO EARLY MONDAY MORNING WHEN A SHORTWAVE TROUGH
CROSSES THE REGION. SNOW LEVEL WILL THEN FALL AGAIN NEAR 6,000 FEET
LATE SUNDAY. ACROSS WESTERN NEVADA, COULD SEE RAINFALL AMOUNTS NEAR
AN INCH IN THE FOOTHILLS WITH AROUND ONE HALF INCH ALONG THE SIERRA
FRONT AND A THIRD OF AN INCH ACROSS THE BASIN AND RANGE AREAS
THROUGH EARLY MONDAY MORNING. FUENTES
THE WEATHER IS EXPECTED TO SETTLE DOWN FOR THE FIRST HALF OF THE
WORK WEEK AS THE MOISTURE FEED DISSIPATES OVER CALIFORNIA AND
NEVADA AND A NEW FEED DIRECTS ITSELF TOWARDS THE PACIFIC
NORTHWEST.
MONDAY, THE UPPER DISTURBANCE ON THE TAIL END OF THIS WEEKEND`S
MOISTURE TAP WILL PUSH OFF INTO EASTERN NEVADA AND UTAH. THIS WILL
MEAN SHOWERS TAPERING OFF DURING THE DAY WITH SNOW LEVELS FALLING TO
BETWEEN 5000-6500 FEET (BUT LITTLE OR NO ADDITIONAL SNOWFALL).
TUESDAY AND WEDNESDAY, NORTHERN CALIFORNIA AND NEVADA WILL BE ON THE
SOUTHERN PERIPHERY OF THE MAIN STORM TRACK AS AN UPPER TROUGH DIGS
OVER THE NORTH CENTRAL PACIFIC AND PUMPS UP A RIDGE OVER THE REGION.
MODELS INDICATE PLENTY OF MID-HIGH LEVEL MOISTURE SO I HAVE LEFT
MOSTLY CLOUDY SKIES IN THE FORECAST. PRECIPITATION-WISE, THERE IS
SOME UNCERTAINTY AS TO WHETHER OR NOT WE COULD SQUEEZE OUT PERIODIC
LIGHT SHOWERS NORTH OF INTERSTATE 80 DEPENDING ON HOW THE FAST FLOW
TO OUR NORTH BUCKLES WITH MINOR DISTURBANCES MOVING OVER THE RIDGE.
THEREFORE, I HAVE LEFT LOW POP IN BUT TRIMMED IT BACK TO AREAS
GENERALLY NORTH OF INTERSTATE 80. SNYDER
AVIATION...
CIRRUS CLOUDS AHEAD OF AN UPPER DISTURBANCE ABOUT 600 MILES WEST
OF KSFO HAVE SPREAD INTO NORTHERN CALIFORNIA. THIS DISTURBANCE
WILL MOVE INTO THE SIERRA AND WESTERN NEVADA BETWEEN 09Z-15Z
THURSDAY, BRINGING -SN/-SHSN AND WIDESPREAD TERRAIN OBSCURATION
(ESPECIALLY SIERRA AND WESTERN NV PEAKS) TO THE AREA THROUGH
THURSDAY AFTERNOON.
AS FAR AS SIERRA TERMINAL IMPACTS, IFR/LIFR CIGS/VSBYS EXPECTED FOR
MOST OF THURSDAY IN NORTHERN SIERRA WITH SEVERAL INCHES OF SNOWFALL
ON UNTREATED SURFACES. FOR KMMH, -SHSN POSSIBLE IN THE MORNING
THURSDAY BUT THE HEAVIEST SNOWFALL SHOULD BE IN THE 19Z/11 AM TO
00Z/4 PM TIME FRAME.
FOR WESTERN NEVADA TERMINALS (INCLUDING KRNO/KCXP) THURSDAY, A
PERIOD OF -SN LIKELY IN THE MORNING FOLLOWED BY SNOW SHOWERS IN THE
AFTERNOON. CIGS/VSBY LOOK GENERALLY LOWEST IN THE MORNING, WITH MORE
INTERMITTENT LOWERING IN -SHSN IN THE AFTERNOON. GIVEN THAT SNOW IS
EXPECTED TO START BY AROUND SUNRISE, UNTREATED PAVEMENT AT TERMINALS
COULD SEE A LIGHT ACCUMULATION (MOST LIKELY LESS THAN ONE INCH).
CONFIDENCE IN A LIGHT ACCUMULATION IS AROUND 40%. AFTER 18-19Z,
GROUND TEMPERATURES SHOULD COME UP ENOUGH TO MELT ROAD/RUNWAY
SURFACES. SNYDER
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...HIGH WIND WATCH FROM FRIDAY EVENING THROUGH SATURDAY MORNING
NVZ003.
WINTER WEATHER ADVISORY FROM 4 AM TO 10 PM PST THURSDAY NVZ002.
CA...WINTER WEATHER ADVISORY FROM 4 AM TO 10 PM PST THURSDAY CAZ073.
HIGH WIND WATCH FROM FRIDAY EVENING THROUGH SATURDAY MORNING
CAZ073.
WINTER WEATHER ADVISORY FROM 4 AM TO 10 PM PST THURSDAY CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
953 PM MST WED FEB 5 2014
.UPDATE...
ISSUED AT 952 PM MST WED FEB 5 2014
SNOW HAS BEEN SLOW TO GET STARTED THIS EVENING. MOST PRECIPITATION
WAS TO OUR NORTH ALONG THE 700 MB BAROCLINIC BAND THAT STRETCHED
FROM SRN ID ACROSS SRN WY. BUT...RABBIT EARS SNOTEL RECORDED LIGHT
SNOW IN THE PAST HOUR...AND MT WERNER OBS SHOWING LOWERED CLOUDS AND
VISIBILITY. STILL EXPECT SNOW TO EXPAND INTO THE NORTHERN AND CENTRAL
MOUNTAINS OVERNIGHT IN THE WAKE OF A SHORTWAVE NOW JUST BRUSHING OUR
NRN BORDER. HIGH RESOLUTION HRRR MODELS SHOWING THE INITIAL SNOW TO
BE MOSTLY LIGHT...HOWEVER. FORECAST GRIDS UPDATED EARLIER TO REFLECT
THIS SLOWER START.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 317 PM MST WED FEB 5 2014
YESTERDAYS COLD FRONT HAS RETREATED TO CLOSE TO THE WYOMING BORDER
THIS AFTERNOON. MOST VALLEY TEMPERATURES STILL LAG TUESDAY
AFTERNOON INDICATING INVERSIONS ARE IN PLACE. THIS FORECAST AREA
REMAINS SANDWICHED BETWEEN A TROUGH PROGRESSING THROUGH THE DESERT
SW AND AN ELONGATED W-E TROUGH ALONG THE NORTHERN TIER STATES WITH
BOTH FEATURES SHIFTING EAST BY THURSDAY.
TONIGHT...MOISTURE IS STILL PROGGED TO INCREASE ESPECIALLY ACROSS
THE NORTHERN ZONES. LACK OF DYNAMICAL SUPPORT AND WEAK MID-LEVEL
WARM ADVECTION WILL LIMIT MOST SNOWFALL TO THE NORTHERN AND
CENTRAL COLORADO MOUNTAINS.
THURSDAY-THURSDAY NIGHT...THE TAIL OF THE SHEARED TROUGH RAKES THE
SOUTHERN ZONES BRINGING LIGHT SHOWERS TO THE SAN JUANS ESPECIALLY
TO THE HILLS ABOVE PAGOSA SPRINGS. OTHERWISE OROGRAPHIC WNW FLOW
WILL CONTINUE TO PRODUCE WIDESPREAD BUT LIGHT MOUNTAIN SNOWFALL.
VALLEY INVERSIONS WILL BEGIN TO BE ERODE AS SNOW SHOWERS/VIRGA
AND BRISK MTN WINDS WORK ON THE TOP OF INVERSIONS. SIGNIFICANT
OVERRUNNING SNOWFALL NEEDS TO BE WATCHED FOR CRAIG-STEAMBOAT AREA.
COORDINATED WITH THE PUEBLO OFFICE TO CARRY SUB-ADVISORY SNOW
AMOUNTS IN THE SOUTHERN MTNS THROUGH THURSDAY NIGHT. THE NE UTAH
UINTA MTNS TOO WERE EXPECTED TO GET ONLY LIGHT ACCUMULATIONS
THROUGH THESE PERIODS AS THE SURFACE FRONT REMAINS NORTH OF THAT
ZONE AND WEST OROGRAPHICS ARE UNFAVORABLE THERE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 317 PM MST WED FEB 5 2014
12Z MODELS BRING A TROUGH THROUGH THE GREAT BASIN OVERNIGHT INTO
FRIDAY AND IS EXPECTED TO BRING A WAVE OF ENERGY INTO WESTERN CO
ON FRIDAY MORNING. THE REAPPEARANCE OF THE UPPER LEVEL JET ON
FRIDAY WILL ALLOW WINDS TO INCREASE WITH THE PROBABILITY OF SNOW
AND ALLOW FOR GOOD DIVERGENCE ALOFT. GFS HAS A 110KT TO 120KT JET
MAX MOVING INTO THE REGION ON SATURDAY...WHICH IS WHEN THE MOST
WIDESPREAD AND EFFICIENT SNOWFALL IS EXPECTED WITH THIS NEXT
SERIES OF SYSTEMS. HOWEVER...SINCE MODELS HAVE NOT BEEN
CONSISTENT...HAVE KEPT FROM ISSUING ANY NEW HAZARDS THIS AFTERNOON
FOR THE LONGER RANGE. IT DOES APPEAR THAT ADVISORIES WILL BE
NEEDED FOR THE SAN JUANS AND POTENTIALLY ALONG PARTS OF THE I-70
CORRIDOR FROM ABOUT GLENWOOD SPRINGS AND EAST FOR THE WEEKEND.
LOOKING FOR SOME BETTER CONSISTENCIES BETWEEN MODEL RUNS BEFORE
MAKING THAT DECISION.
SNOW LEVEL WILL RISE THROUGHOUT THE AFTERNOON ON SATURDAY AS THE
JET STREAM LIFTS NORTH AND BEGINS TO MIX OUT THE COLD AIR POOL
WHICH HAS BEEN IN PLACE THE LAST FEW DAYS SINCE THE LAST SNOWFALL. MOS
GUIDANCE IS SHOWING UNSEASONABLY WARM TEMPS ON SUNDAY AND MONDAY.
KEPT TEMPS IN THE VALLEYS SLIGHTLY COOLER THAN MOS GUIDANCE
CONSIDERING THE SNOW COVER BUT TEMPERATURES WILL LIKELY RISE ABOVE
FREEZING IN CENTRAL COLORADO VALLEYS IN THE AFTERNOON AND EARLY
EVENING...WHICH MAY RESULT IN A RAIN/SNOW MIX IF PRECIPITATION
ACCOMPANIES THIS WARM AIR ADVECTION.
IF TRAVELING ACROSS THE I-70 CORRIDOR THIS WEEKEND...BE PREPARED FOR
POTENTIAL WINTER WEATHER. LONG RANGE MODELS SUGGEST THAT SNOW
WILL CONTINUE OVER VAIL PASS FRIDAY THROUGH MIDWEEK...THOUGH THE
SNOW INTENSITY WILL VARY BASED ON THE TIMING OF THE SHORTWAVE
DISTURBANCES. PWAT INCREASES SATURDAY THROUGH MONDAY ACROSS THE
REGION. CURRENT MODELS SHOW A POTENTIALLY WIDESPREAD...BUT FAST
MOVING...PRECIPITATION EVENT BEGINNING ON MONDAY MORNING. BOTH
THE GFS AND EC INDICATE THIS SYSTEM MOVING IN VERY EARLY MONDAY
MORNING AND CONTINUING THROUGHOUT THE DAY.
THIS ACTIVE ZONAL PATTERN CONTINUES THROUGH MID NEXT WEEK...THEN
THE LONG RANGE GFS AND EC SUGGEST DEVELOPMENT OF A WEAK RIDGE OVER
THE WEST COAST. THIS RIDGING WOULD PUT THE AREA BACK INTO
NORTHWEST FLOW AND KEEP THE NORTHCENTRAL MTNS IN THE MOST
FAVORABLE LOCATION FOR PRECIPITATION MID FEBRUARY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 952 PM MST WED FEB 5 2014
WESTERLY FLOW ALOFT WILL PREVAIL THROUGH THU EVENING. MOISTURE IN
THE FLOW WILL RESULT IN OCCASIONAL -SN ACROSS THE NORTHERN AND
CENTRAL MTNS BY 12Z THU...AND THE SOUTHERN MTNS BY 18Z. LOWERING CIGS
WILL RESULT IN MTN TOPS BECOMING OBSCURED. VFR WILL BE THE
PREVAILING CONDITIONS AT THE VALLEY TAF SITES WITH SOME PERIODS MVFR
CIGS/VSBY IN -SN AT KRIL/KEGE AFTER 12Z. LONGER PERIODS OF MVFR IN
-SN WITH POSSIBLE IFR VSBY AT TIMES ARE EXPECTED AT KASE AFTER
09Z...AND AT KTEX AFTER 15Z.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL 6 PM MST SATURDAY
COZ004-009-010-012-013.
WINTER STORM WARNING UNTIL 6 PM MST SATURDAY ABOVE 7500 FEET FOR
COZ003.
UT...NONE.
&&
$$
UPDATE...JAD
SHORT TERM...JOE
LONG TERM...JAM
AVIATION...JAD
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
908 PM EST Fri Feb 7 2014
.Near Term [Through Tonight]...
A fairly zonal upper level pattern currently exists over the CONUS,
with a weak trough in place over the southern Plains and a strong
jet streak stretching from Texas through the Mid-Atlantic region.
At the surface, dry northeasterly flow is currently in place over
our CWA, but as a mid-level disturbance moves eastward into the
Southeast, precipitation chances will increase overnight into
Saturday morning. Weak isentropic ascent combined with this
disturbance, and also aided by synoptic forcing near the right
entrance region of the upper level jet streak, will lead to a good
chance of light to moderate rain near the end of the period. The CAM
and HRRR models held off on bringing rain into our area until after
06Z, so POPs were trimmed back a bit before 06Z. Otherwise, the
current forecast looks to be on track. Overnight lows are expected
to range from near 40 in NW counties to upper 40s/near 50 in the
eastern Big Bend region.
&&
.Aviation...
[Through 00Z Sunday]...
VFR conditions are expected to gradually deteriorate this evening
as MVFR ceilings spread into the FL Big Bend and south-central GA.
In addition, a fast moving weather system will skirt the region
later tonight and early Saturday and bring MVFR cigs and a chance
of rain for all sites. Expect conditions to rebound to VFR fairly
quickly after 14/15z over wrn sites and spread eastward by early
to mid afternoon.
&&
.Prev Discussion [309 PM EST]...
.Short Term [Saturday Through Sunday Night]...
The large scale pattern will commence with weak ridging west half
and weak troughing east half of Conus. During the rest of the
period...Ern troughing broadens and lifts NEWD and mid-upper local
flow becomes largely zonal with tight gradients which typically
means a fairly quick return period for short wave troughs.
Saturday...the day begins with latest shortwave digging along Nrn
gulf coast. At the surface...low located just east of GA/SC border
with quasi-stnry front across N/Cntrl FL with overrunning north of
boundary. Shortwave kicking front back SEWD which should yield a
sharp 20-80% NW-SE morning POP gradient. Area PWATs all over one
inch. Weak instability should preclude any tstms. By afternoon...
as the shortwave exits Ewd in Atlc...low deepens and ejects Newd
to just off Carolina coast with front further SEWD into S/Cntrl
FL. Thus the rain will end from west to east. This will be
followed by clearing and mild temperatures with highs around 60.
Saturday Night...In wake of front...surface high builds Swd from TN
Valley into Gulf region. Area PWATs drop to one-half inch or less by
sunrise. Expect mostly clear skies with minimum temps near seasonal
average...around 40.
Sunday and Sunday Night...The high will move Ewd and settle over
Gulf during day and across local area at night. Expect sunny skies
with highs in the mid to upper 60s to around 70 south. Lows at
night around 40.
.Long Term [Monday Through Friday]...
The long term pattern begins fairly deamplified with broad Ern
trough over NE states yielding tight zonal flow across SE region.
At the surface...strong high pressure centered over or just off
N/Cntrl FL. Locally this translates to generally WLY steering flow
and warming temps. However...models all showing this pattern
rapidly shifting beginning Tues as a series of strong shortwaves
over the Srn Plains on Monday eject Ewd and move across the SE
region Tues night thru Wed increasingly amplifying Ern longwave
trough. However here models diverge with ECMWF stronger in
developing low level feature across Wrn Gulf Coast while GFS
weaker with more amorphous low or trough and non-tstm event over
Gulf waters. For now will lean towards more ominous ECMWF which
generates significant cyclogenesis and causes LA low to develop
and strengthen on SW-NE cold front which reaches N/Cntrl Gulf
Coast Tues night with warm front stretching Ewd along coast.
Further amplification of pattern on Wed will eject low Newd across
local area...lifting warm boundary Nwd to stall over region
(likely FL/AL/GA border) early Wed followed by cold front moving
SEWD and across during the day. So rain chances noticeably
increase Tues aftn thru Wed with local area..especially FL/waters
increasingly in warm sector. Thus there is a chance of severe
weather...heavy rain with at least some flooding concerns
depending on ultimate position of upper/lower features. In wake of
departing low/front...high noses down Ern seaboard and cooler and
drier air overspread the region Thurs into Fri.
Expect increasing cloudiness with moderating temps beginning on Mon
ahead of next system. High Temps Mon mid 60s to low 70s...mid 50s to
around 70 Tues...50 to 70 Wed with large gradient due to advancing
front...60-68 Thurs and Fri. Min temps will remain above freezing
each night. Will go with NIL pops Mon...30-0 NW-SE POPS Mon night...
50-20% Tues...60-30% Tues night...70-50% Wed all with N-S
gradient...30-40% Wed night then NIL POPs.
.Marine...
Winds and seas will subside into tonight as high pressure builds
into the region. Expect a brief increase in winds Saturday morning
as an upper level disturbance moves Ewd across the area. Otherwise
weak high pressure will build over much of the Nrn Gulf yielding
fairly low winds and seas into the upcoming work week.
.Fire Weather...
A widespread rain event is anticipated overnight before dry
conditions return for the next few days. Even though it will dry out
into Monday, red flag conditions are not anticipated. The next
frontal system will approach the region on Tuesday bringing another
chance of rain.
.Hydrology...
Rainfall amounts form Thursday`s upper level disturbance ranged
from a tenth of an inch or less across most of the region, to 0.75
inches in a few narrow bands across North FL (around the Perry and
Mayo areas). No significant river rises have occurred (or are
expected) from this batch of rain. The only site that was still at
"action" stage was along the Apalachicola River at Blountstown,
but even this site appeared to be in a broad crest and will likely
begin a decline in a few days. The next system is expected to
produce QPF amounts ranging from a tenth of an inch northwest of
Albany and Dothan, to half an inch around Cross City and Perry.
Again, it`s unlikely that these amounts would significantly alter
the local river stages/flows.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 46 62 41 69 41 / 100 50 0 0 0
Panama City 46 58 48 65 47 / 90 40 0 0 0
Dothan 42 60 41 67 41 / 90 20 0 0 0
Albany 40 60 40 67 40 / 100 30 0 0 0
Valdosta 45 61 41 68 42 / 100 60 0 0 0
Cross City 50 61 42 71 42 / 80 70 10 0 0
Apalachicola 46 60 48 65 46 / 100 50 0 0 0
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...LAHR/HARRIGAN
SHORT TERM...BLOCK
LONG TERM...BLOCK
AVIATION...EVANS
MARINE...BLOCK
FIRE WEATHER...GODSEY
HYDROLOGY...WESTON
AREA FORECAST DISCUSSION
NWS MIAMI FL
246 PM EST THU FEB 6 2014
.DISCUSSION...
STALLED FRONTAL BOUNDARY REMAINED DRAPED ACROSS THE LAKE REGION
EARLY THIS AFTERNOON. A FEW SHOWERS WERE ALSO BEGINNING TO DEVELOP
ALONG THE BOUNDARY. SCATTERED SHOWERS AND A FEW THUNDERSTORMS
REMAIN IN THE FORECAST THROUGH THE AFTERNOON HOURS. A FEW SHOWERS
COULD LINGER INTO THE OVERNIGHT HOURS ACROSS THE INTERIOR AND PALM
BEACH COUNTY.
LOW CEILINGS AND FOG IS EXPECTED AGAIN TONIGHT. SREF IS SHOWING
NEAR 100 PERCENT PROBABILITY OF CEILINGS BELOW 1000FT FROM SOUTH
OF NAPLES AND ACROSS GLADES AND HENDRY COUNTIES. DENSE SEA FOG IS
POSSIBLE AGAIN THIS EVENING OVER THE GULF WATERS...THEN AFTER
MIDNIGHT WINDS ARE EXPECTED TO INCREASE OUT OF THE NORTHEAST AND
THAT SHOULD PUT AN END TO THE FOG THERE. SOME GUIDANCE SUGGESTS
THAT FOG COULD DEVELOP ACROSS THE INTERIOR AND THEN PUSH INTO THE
METRO AREAS LATE TONIGHT AS THE BOUNDARY LAYER WINDS SHIFT TO THE
WEST. SO PUSHED THE PATCHY FOG CHANCE TO THE COAST AND AREAS OF
FOG INTO THE METRO AREAS FOR TONIGHT. DENSE FOG IS ALSO POSSIBLE.
THE FRONTAL BOUNDARY IS FORECAST TO LIFT SLOWLY BACK NORTHWARD ON
FRIDAY AS A WARM FRONT. SOME SLIGHT DRYING IS FORECAST TO TAKE
PLACE IN THE LOW LEVELS ON FRIDAY...BEFORE DEEPER MOISTURE SURGES
BACK INTO THE REGION FRIDAY NIGHT INTO SATURDAY.
AN AREA OF LOW PRESSURE IS FORECAST TO DEVELOP ALONG THE FRONTAL
BOUNDARY OFF OF THE EAST CENTRAL FLORIDA COAST FRIDAY NIGHT INTO
SATURDAY. THIS LOW WILL THEN MOVE OFF TO THE NORTHEAST THROUGH THE
WEEKEND. THIS WILL FORCE THE FRONTAL BOUNDARY BACK SOUTH...AND
INCREASE RAIN CHANCES ON SATURDAY AND INTO SUNDAY. THE FRONT IS
THEN FORECAST TO PUSH SOUTH OF THE REGION BY SUNDAY EVENING...WITH
DRIER AIR PUSHING INTO SOUTH FLORIDA. IT WILL BE WARM THIS WEEKEND
WITH HIGHS IN THE 80S AND HEAT INDICES NEARING 90.
HIGH TEMPERATURES WILL NOT BE AFFECTED EARLY NEXT WEEK BY THE
FRONTAL PASSAGE...BUT DEWPOINTS WILL DROP 5-10 DEGREES AND
OVERNIGHT LOWS WILL BE SEVERAL DEGREES COOLER. THE DRY AND
COMFORTABLE WEATHER WILL NOT LAST LONG. ANOTHER AREA OF LOW
PRESSURE WILL DEVELOP OVER THE NORTHWESTERN GULF OF MEXICO AND
MOVE NORTHEAST ACROSS THE SOUTHEASTERN UNITED STATES BY THE MIDDLE
OF NEXT WEEK. IN TURN...MOISTURE WILL THEN INCREASE AGAIN FROM THE
SOUTH.
&&
.AVIATION...
A COLD FRONT STALLED ACROSS THE AREA WILL CONTINUE TO INFLUENCE
THE LOCAL WEATHER THROUGH THE 24 HR TAF PERIOD...MAINLY FOR
REDUCED CIGS AND VSBYS AT SITE APF AND INCREASED SHOWER/TSTM
CHANCES AROUND PBI. THE LATEST HRRR AND WRF MODEL REFLECTIVITIES
INDICATE THE BEST RAIN CHANCES SETTING UP ACROSS THE INTERIOR AND
NORTHERN LOCATIONS FROM THE LAKE TO THE PALM BEACHES THROUGH THE
AFTERNOON HOURS TODAY. ALTHOUGH THE BULK OF THIS ACTIVITY SHOULD
REMAIN JUST INLAND OF THE PBI SITE...ANY EWD SHIFT TOWARD THE
COAST THROUGH THE LATE AFTERNOON/EARLY EVENING HOURS COULD RESULT
IN REDUCED VSBYS/CIGS IN AND AROUND ANY ACTIVITY. SIMILAR TO THIS
MORNING AND THROUGH THE OVERNIGHT HOURS LAST NIGHT...CIGS/VSBYS
DUE FOG WILL BECOME THE MAIN CONCERN...MAINLY FOR SITE APF AND
POSSIBLY TMB. THIS MAY LINGER THROUGH THE MID-MORNING HOURS FRIDAY
BEFORE BURNING OFF OR LIFTING. 85/AG
&&
.MARINE...
THE WINDS WILL REMAIN BELOW 10 KNOTS THROUGH THIS WEEKEND...EXCEPT
OVER THE GULF WATERS TONIGHT WHERE WINDS WILL INCREASE TO 10-15
KNOTS. THIS WILL KEEP THE SEAS 4 FEET OR LESS THROUGH THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 67 80 68 83 / 20 10 10 30
FORT LAUDERDALE 69 78 72 80 / 10 10 10 30
MIAMI 69 80 71 83 / 10 10 10 30
NAPLES 67 81 66 81 / 20 10 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...84/AK
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS MIAMI FL
113 PM EST THU FEB 6 2014
.AVIATION...
A COLD FRONT STALLED ACROSS THE AREA WILL CONTINUE TO INFLUENCE
THE LOCAL WEATHER THROUGH THE 24 HR TAF PERIOD...MAINLY FOR
REDUCED CIGS AND VSBYS AT SITE APF AND INCREASED SHOWER/TSTM
CHANCES AROUND PBI. THE LATEST HRRR AND WRF MODEL REFLECTIVITIES
INDICATE THE BEST RAIN CHANCES SETTING UP ACROSS THE INTERIOR AND
NORTHERN LOCATIONS FROM THE LAKE TO THE PALM BEACHES THROUGH THE
AFTERNOON HOURS TODAY. ALTHOUGH THE BULK OF THIS ACTIVITY SHOULD
REMAIN JUST INLAND OF THE PBI SITE...ANY EWD SHIFT TOWARD THE
COAST THROUGH THE LATE AFTERNOON/EARLY EVENING HOURS COULD RESULT
IN REDUCED VSBYS/CIGS IN AND AROUND ANY ACTIVITY. SIMILAR TO THIS
MORNING AND THROUGH THE OVERNIGHT HOURS LAST NIGHT...CIGS/VSBYS
DUE FOG WILL BECOME THE MAIN CONCERN...MAINLY FOR SITE APF AND
POSSIBLY TMB. THIS MAY LINGER THROUGH THE MID-MORNING HOURS FRIDAY
BEFORE BURNING OFF OR LIFTING. 85/AG
&&
.PREV DISCUSSION... /ISSUED 920 AM EST THU FEB 6 2014/
UPDATE...
A STALLED FRONTAL BOUNDARY WAS LOCATED FROM NEAR FORT MYERS
NORTHEASTWARD THROUGH VERO BEACH THIS MORNING. DENSE FOG FORMED
SOUTH OF THIS BOUNDARY...WITH VISIBILITIES 1/4 MILE OR LESS ACROSS
MUCH OF THE WESTERN INTERIOR. THE FOG IS BEGINNING TO LIFT AND THE
DENSE FOG ADVISORY WAS ALLOWED TO EXPIRE FOR THE LAND AND WATER
AREAS AT 9 AM. DENSE FOG DEVELOPED OVER THE LOCAL GULF WATERS
WEST OF NAPLES LAST NIGHT. BEACH CAMS SHOW SOME FOG STILL
REMAINS...SO WILL KEEP PATCHY FOG IN THE FORECAST FOR THE GULF
WATERS THROUGHOUT THE DAY. DENSE FOG COULD REDEVELOP OVER THE
WATER THIS EVENING.
THE SURFACE BOUNDARY IS FORECAST TO REMAIN NEARLY STATIONARY
TODAY...AND SHOWERS AND A FEW THUNDERSTORMS ARE FORECAST TO
DEVELOP ALONG AND SOUTH OF THIS BOUNDARY. THE BEST CHANCE OF
SHOWERS AND STORMS IS ACROSS THE INTERIOR THIS AFTERNOON...WITH
SOME SHOWERS POSSIBLY MOVING INTO THE METRO AREAS OF PALM BEACH
AND BROWARD COUNTIES AS WELL. THE GLOBAL MODELS AS WELL AS THE
LOCAL WRF MODELS AND HRRR ARE ALL IN GOOD AGREEMENT ON THIS
SCENARIO THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 628 AM EST THU FEB 6 2014/
AVIATION...
KAPF WILL SLOWLY COME OUT OF THE IFR CONDITIONS BY 14Z THIS
MORNING DUE TO THE FOG BURNING OFF. REST OF THE TAF SITES WILL BE
IN THE VFR CONDITIONS TODAY. SHOWERS/TSTORMS LOOK TO FOCUS OVER
THE INTERIOR THIS AFTERNOON. KPBI STANDS THE BETTER CHANCE OF A
FEW SHRA/TSRA MOVING IN FROM THE WEST LATE THIS AFTERNOON SO
INCLUDED VCTS THERE. BNB
PREV DISCUSSION... /ISSUED 310 AM EST THU FEB 6 2014/
ABOVE NORMAL TEMPERATURES CONTINUE THROUGH THE WEEKEND OVER SOUTH FLORIDA...
PATCHY TO AREAS OF FOG EACH NIGHT THROUGH THE WEEKEND...
SHORT TERM...
FOG HAS DEVELOPED EARLY THIS MORNING OVER THE WESTERN AREAS OF
SOUTH FLORIDA WITH ISOLATED AREAS OF DENSE FOG. THE FOG SHOULD
CONTINUE OVER THE WESTERN AREAS THROUGH SUNRISE WHILE SPREADING
INTO THE EASTERN INTERIOR AREAS OF SOUTH FLORIDA. SO A DENSE FOG
ADVISORY HAS BEEN ISSUED FOR THE WESTERN AREAS OF SOUTH FLORIDA
THROUGH 9 AM EDT THIS MORNING...AND WE WILL CONTINUE TO MONITOR
THE EASTERN INTERIOR AREAS OF SOUTH FLORIDA THROUGH THE EARLY
MORNING HOURS TO SEE IF THE DENSE FOG ADVISORY NEEDS TO BE
EXPANDED EASTWARD.
A COLD FRONT OVER CENTRAL FLORIDA WILL CONTINUE TO MOVE SLOWLY
SOUTH TODAY...BEFORE STALLING OVER THE LAKE OKEECHOBEE REGION
TONIGHT. THIS WILL KEEP THE WIND FLOW OVER SOUTH FLORIDA IN A
SOUTHERLY DIRECTION TODAY ALONG WITH THE EAST AND WEST COAST SEA
BREEZES DEVELOPING AND PUSHING INLAND. SO THE BEST COVERAGE OF
SHOWERS WILL BE OVER THE INTERIOR AREAS TODAY ALONG WITH A FEW
STORMS LATE THIS AFTERNOON. THERE COULD ALSO BE A FEW STORMS OVER
METRO PALM BEACH COUNTY LATE THIS AFTERNOON INTO EARLY THIS
EVENING...AS THE STEERING FLOW WILL BECOME MORE SOUTHWEST AHEAD OF
THE FRONT.
FOG IS AGAIN POSSIBLE TONIGHT OVER MOST OF SOUTH FLORIDA WITH EVEN
SOME DENSE FOG POSSIBLE OVER THE INTERIOR AND WEST COAST METRO
AREAS...DUE TO THE FRONT NEARBY AND THE LIGHT SOUTH TO SOUTHWEST
STEERING FLOW. SO HAVE PUT IN FOG WORDING OVER MOST OF SOUTH FLORIDA
FOR LATE TONIGHT INTO EARLY FRIDAY MORNING WITH EVEN ISOLATED DENSE
FOG OVER THE INTERIOR AND WEST COAST METRO AREAS.
THE STATIONARY FRONT OVER LAKE OKEECHOBEE REGION WILL MOVE BACK
NORTHWARD INTO NORTHERN FLORIDA ON FRIDAY...AS A WEAK LOW
PRESSURE DEVELOPS OVER THE NORTHERN GULF OF MEXICO. THIS WILL
ALLOW FOR THE STEERING FLOW TO BE SOUTHEAST OVER SOUTH FLORIDA ON
FRIDAY BRINGING IN SOME DRIER AIR TO THE AREA FROM THE BAHAMA
ISLANDS. SO THE ONLY AREA THAT WILL SEE A SLIGHT CHANCE OF SHOWERS
WILL BE OVER THE INTERIOR AND WEST COAST METRO AREAS ON FRIDAY.
THE WEAK LOW WILL MOVE NORTHEAST ACROSS NORTHERN FLORIDA ON
SATURDAY BEFORE MOVING INTO THE WESTERN ATLANTIC WATERS ON SUNDAY.
THIS WILL ALLOW FOR THE WARM FRONT TO BECOME A COLD FRONT AND MOVE
SOUTH THROUGH SOUTH FLORIDA ON SUNDAY. SO THE SLIGHT CHANCE OF
SHOWERS WILL CONTINUE OVER SOUTH FLORIDA THIS WEEKEND...EXCEPT FOR
A CHANCE OF SHOWERS AROUND THE LAKE OKEECHOBEE REGION ON SATURDAY.
HIGHS THROUGH THIS WEEKEND WILL BE IN THE LOWER TO MID 80S WITH
LOWS IN THE 60S...EXCEPT AROUND 70 ALONG THE EAST COAST METRO
AREAS. THESE HIGHS AND LOWS ARE ABOUT 5 TO 10 DEGREES ABOVE THE
AVERAGE FOR THIS TIME OF YEAR. THE HEAT INDEX WILL ALSO BE RUNNING
IN THE MID 80S TO AROUND 90 DEGREES THIS WEEKEND.
LONG TERM...
DRY AND MORE COMFORTABLE WEATHER WILL RETURN TO SOUTH FLORIDA EARLY
NEXT WEEK BEHIND THE PASSAGE OF THE COLD FRONT LATE THIS WEEKEND.
HOWEVER...THE DRY AND COMFORTABLE WEATHER WILL NOT LAST LONG AS
ANOTHER LOW PRESSURE WILL DEVELOP OVER THE NORTHWEST GULF OF
MEXICO AND MOVE NORTHEAST ACROSS THE SOUTHEASTERN UNITED STATES BY
MIDDLE OF NEXT WEEK. THIS IN TURN WILL BRING THE WINDS BACK TO A
SOUTHERLY DIRECTION AND BRING IN THE MOISTURE FROM THE SOUTH BY THE
MIDDLE OF NEXT WEEK. THERE WILL ALSO BE A 20 TO 30 PERCENT CHANCE OF
SHOWERS OVER THE AREA MIDDLE OF NEXT WEEK.
AVIATION...
KAPF JUST WENT DOWN TO 1/4SM FG AND LOOKS AS THOUGH
THIS MAY HANG IN ALL NIGHT SO KEPT THIS CONDITION GOING. ELSEWHERE
THE THINKING IS THAT LOW CLOUDINESS WILL DEVELOP IN MVFR CATEGORY.
WILL HAVE TO KEEP AN EYE OUT FOR POSSIBLE IFR AS WELL, BUT GIVEN
UNCERTAINTIES MAINTAINED MVFR EAST COAST SITES. POSSIBLE
IMPROVEMENT DURING THE DAY, BUT MVFR COULD HANG ON THROUGHOUT THE
DAY...ESPECIALLY AT KAPF. SHOWERS/TSTORMS LOOK TO FOCUS OVER THE
INTERIOR THIS AFTERNOON. KPBI STANDS THE BETTER CHANCE OF A FEW
SHRA/TSRA MOVING IN FROM THE WEST LATE THIS AFTERNOON SO INCLUDED
VCTS THERE. /GREGORIA
MARINE...
THE WINDS WILL REMAIN BELOW 10 KNOTS TODAY INTO THIS WEEKEND WHILE
SLOWLY REMAINING IN A SOUTHERLY DIRECTION. THIS WILL KEEP THE SEAS
BELOW 6 FEET TODAY INTO THIS WEEKEND IN BOTH THE ATLANTIC AND GULF
WATERS. SO BOATING CONDITIONS SHOULD BE GOOD THIS WEEKEND OUTSIDE
OF ANY SHOWERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 67 82 68 83 / 30 10 10 20
FORT LAUDERDALE 70 83 72 83 / 20 10 10 20
MIAMI 71 84 71 84 / 20 10 10 20
NAPLES 63 82 64 81 / 20 20 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/DG
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1020 AM EST THU FEB 6 2014
.UPDATE (REST OF TODAY AND TONIGHT)...
15Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A RATHER UNAMPLIFIED UPPER
LEVEL PATTERN OVER THE CONUS...HIGHLIGHTED BY WEAK RIDGING ALONG
BOTH THE PACIFIC AND ATLANTIC COASTS AND SUBTLE TROUGHING THROUGH
THE CENTRAL PLAINS/MS VALLEY. ONE MORE SIGNIFICANT SHORTWAVE MOVING
ACROSS TEXAS/NORTHERN MEXICO THROUGH THE BASE OF THE LONGWAVE TROUGH
SHOWS A DEFINED SUBSIDENCE/DRYING PATTERN IN ITS WAKE. THIS FEATURE
WILL QUICKLY TRANSLATE EASTWARD AND HAVE A GLANCING INFLUENCE ON THE
FORECAST FOR THE FL PENINSULA LATER TODAY INTO TONIGHT AS IT BEGINS
TO SHEAR OUT AND PASS TO OUR NORTH. UPSTREAM 06/12Z SOUNDING PROFILE
FROM KTBW SHOWS A SPLIT COLUMN FEATURING A MOIST ENVIRONMENT BELOW A
WEAK 500MB SUBSIDENCE INVERSION...AND MUCH DRIER AIR FOR THE
REMAINDER OF THE TROP. THE MOIST LOWER LEVELS LEAD TO A HIGH OVERALL
PW FOR THIS PROFILE AROUND 1.56". THIS VALUE IS APPROACHING 2
STANDARD DEVIATIONS ABOVE CLIMATOLOGY FOR EARLY FEBRUARY.
AT THE SURFACE...A COLD FRONT PASSED THROUGH THE REGION LAST
NIGHT AND IS NOW QUASI-STATIONARY OVER THE SOUTH-CENTRAL FLORIDA
PENINSULA. SEEING A BIG DEWPOINT GRADIENT ACROSS THE BOUNDARY THIS
MORNING WITH VALUES IN THE 30S AND 40S APPROACHING THE I-10
CORRIDOR...AND UPPER 60S TO LOWER 70S DOWN BY LAKE OKEECHOBEE.
UNLIKE MANY FRONT WE SEE...WHERE SKIES CLEAR AND RAIN CHANCES END
AFTER THE FRONTAL PASSAGE (KATAFRONT)...THIS PATTERN IS KNOWS AS
ANAFRONT...AND IS HIGHLIGHTED BY CONDITIONS SUPPORTING CLOUDS AND
SHOWERS WITHIN THE POST-FRONTAL ENVIRONMENT. THIS IS WHAT WE ARE
SEEING THIS MORNING WITH NUMEROUS WEST TO EAST MOVING SHOWER
CLUSTERS...GENERALLY TO THE NORTH OF I-4. THESE SHOWERS ARE BEING
SUPPORTED BY A WEAK ISENTROPIC UPGLIDE REGIME WITHIN THE 300-305K
SURFACES AND A BROAD SPEED DIVERGENCE REGIME WITHIN THE MID LEVELS
OF THE TROP.
REST OF TODAY THROUGH THIS EVENING...THE OVERALL SYNOPTIC PATTERN AND
LIFTING MECHANISMS WILL HOLD IN PLACE ALONG AND NORTH OF THE I-4
CORRIDOR...KEEPING RAIN CHANCES RATHER HIGH. IF ANYTHING...THE UPPER
JET SUPPORT OVER THE NORTHERN PENINSULA INCREASES WITH TIME...ALONG
WITH AN SLOW INCREASE IN SYNOPTIC SUPPORT/QVECTOR CONVERGENCE
ASSOCIATED WITH THE SHORTWAVE APPROACHING AND PASSING TO OUR NORTH.
SOUTH OF THE I-4 CORRIDOR...THE LARGER SCALE LIFT WILL BE MUCH
WEAKER. HOWEVER...WHAT WE DO HAVE DOWN SOUTH IS LOW LEVEL FRONTAL
BOUNDARY FOCUS FOR MORE CONVECTIVE TYPE SHOWERS/STORMS LATER TODAY
ONCE DIURNAL HEATING HAS HAD A CHANCE. THE BEST CHANCES FOR THESE
LATER DAY STORMS WILL BE DOWN BY THE FRONT IN OKEECHOBEE...ST
LUCIE...AND MARTIN COUNTIES. THIS ACTIVITY WILL SUBSIDE WITH SUNSET
AND THE LOSS OF TERRESTRIAL HEATING...BUT THE BANDS OF SHOWERS OVER
THE NORTH LOOK TO CONTINUE BEING FEATURED IN THE FORECAST THROUGH AT
LEAST THE EVENING HOURS.
BEHIND THE FRONT WITH ALL THE CLOUDS/SHOWERS...WE WILL SEE A BIG
TEMPERATURE GRADIENT THROUGH THE DAY. THIS WILL BE AMPLIFIED BY
LOCAL WET-BULB EFFECTS ACROSS THE NORTHERN COUNTIES AS THE LIGHT
RAIN FALLS INTO A CONSTANT SUPPLY OF DRIER DEWPOINT AIR FROM THE
NORTH. CURRENT GRIDS SHOW HIGH TEMPERATURES UP TOWARD VOLUSIA AND
LAKE COUNTIES STRUGGLING INTO THE LOWER 60S...AND THEN RANGING UP
INTO THE MID/UPPER 70S ACROSS THE FAR SOUTH. THIS GRADIENT SEEMS
REASONABLE...AND DO NOT ANTICIPATE MUCH CHANGE NEEDED TO THIS PART
OF THE FORECAST.
SYNOPTIC LIFTING MECHANISMS SUBSIDE OVER THE NORTHERN HALF OF THE
PENINSULA DURING THE SECOND HALF OF THE NIGHT AS THE SHORTWAVE TO
OUR NORTH PASSES ON. WILL KEEP A CHANCE POP IN TO THE NORTH OF THE
I-4 CORRIDOR DUE TO WEAK RESIDUAL UPGLIDE AND SPEED DIVERGENCE...
HOWEVER...THE SHOWER ORGANIZATION AND SPATIAL COVERAGE IS LIKELY TO
BE LESS THAN EARLIER. LOW TEMPS LOOK COOL...BUT NOT UNSEASONABLE FOR
EARLY FEBRUARY...WITH MOST LOCATIONS DROPPING INTO THE LOWER/MIDDLE
50S. JUST A BIT WARMER IN THE UPPER 50S TO LOWER 60S CLOSE TO THE
COAST TO THE SOUTH OF MELBOURNE. HAVE A GREAT DAY!
.PREVIOUS DISCUSSION...
FRIDAY...THE STALLED FRONTAL BOUNDARY REMAINS OVER CENTRAL FL TO
LAKE OKEECHOBEE WITH PSBL DEVELOPMENT OF A WAVE ALONG THE BOUNDARY
EAST OF THE STATE BY EVENING. ONGOING FORECAST WITH SCT LIGHT TO
MODERATE RAIN WITH SOME SFC CONVERGENCE AND ISENTROPIC LIFTING ALONG
THE BOUNDARY PREDICTED FOR THE BULK OF THE FORECAST AREA.
CONSIDERABLE CLOUDS WITH RAIN AMOUNTS AROUND A TENTH OF AN INCH WITH
SOME LOCALLY HIGHER AMOUNTS.
WEEKEND...HAD TO KEEP A MENTIONABLE RAIN CHC SAT AND INTO SUN IN
THE FORECAST DUE TO PRESENCE OF BOUNDARY FROM MID AND LATE WEEK
REMAINING IN THE AREA. LOW PRESSURE ADVERTISED TO DEVELOP ALONG
WAVE NE OF STATE LATE SAT WITH VARYING PLACEMENT WL PRODUCE A SCT
RAIN CHC AS FEATURE AND ASCD REINFORCING COLD FRONT DRAG NEAR
AREA. DRYING AND COOLER CONDS SUN AS POST FRONTAL HIGH PRESSURE
WORKS INTO THE SOUTHEAST AND FL PENINSULA.
EXTENDED...CONTINUED DRY EARLY NEXT WEEK WITH CONTINENTAL WINDS
MON BECOMING ONSHORE BY EARLY TUE AND PERSISTING INTO MIDWEEK.
&&
.AVIATION...
SHALLOW OVERRUNNING EVENT BEHIND SFC COLD FRONT ACROSS DEEP S FL IS
PROVIDING MVFR CIGS ACROSS MOST SITES WITH IFR CIGS IN SOME SRN
SITES (VRB) ALONG WITH WEAK SHRA ALONG AND NORTH OF I4. CURRENT
GUIDANCE IS A BIT OVERDONE...INDICATING IFR CONDITIONS SHOULD BE
OCCURRING IN ALL AREAS. WILL KEEP A BIT MORE OPTIMISTIC FORECAST
WITH ALL AREAS BECOMING MVFR AND REMAINING THERE...BUT WILL
RE-EVALUATE LOWER CIG POTENTIAL FOR LATER IN THE DAY AND OVERNIGHT
WITH 18Z TAFS. SCT SHRA WILL REMAIN THROUGH THE PERIOD...ESP ACROSS
SITES FROM MLB TO ISM AND NORTHWARD.
&&
.MARINE...
TODAY AND TONIGHT...CAUTIONARY HEADLINES OVER NORTHERN TWO OFFSHORE
LEGS WILL BE EXPANDED TO INCLUDE ALL OFFSHORE AND NORTHERN NEAR
SHORE LEGS WITH EARLY MORNING PACKAGE AS FRONTAL SURGE WORKS IN FROM
THE NORTH. SOUTHERN OFFSHORE LEG CAUTION WILL BE MORE DUE TO
ANTICIPATED 6 FT SEAS BUILDING DOWN THE WATERS INTO THIS AFTERNOON.
AT THIS POINT APPEARS SOUTHERN NEAR SHORE LEG WILL REMAIN A LITTLE
BELOW CAUTION CRITERIA GIVEN THE DECREASE IN FORWARD MOTION OF THE
FRONT AS IT WORKS DOWN THE WATERS BUT WILL NEED TO BE MONITORED THIS
MORNING. AFTER INITIAL SURGE THIS MORNING WINDS WILL MAINTAIN A
NORTHERLY COMPONENT INTO TONIGHT BUT SPEEDS BACK OFF INTO 10-15KT
RANGE.
END OF WEEK...THE FRONTAL BOUNDARY REMAINS RELATIVELY CLOSE TO
THE LOCAL WATERS INTO SATURDAY. LOW PRESSURE DEVELOPMENT WL CREATE
SOME UNSETTLED CONDITIONS SAT. SEAS 5 TO 6 FT OVER THE OUTER
WATERS BY SAT MAY REQUIRE HEADLINES. NW COUNTERING WINDS WL KEEP
HIGHER SEAS AND WIND WAVES SUN.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 64 54 69 62 / 70 50 50 40
MCO 71 53 72 61 / 60 40 40 40
MLB 73 59 75 66 / 40 40 40 30
VRB 75 60 77 63 / 40 30 30 20
LEE 66 51 68 59 / 70 40 40 40
SFB 68 53 70 61 / 60 40 40 40
ORL 70 54 70 61 / 60 40 40 40
FPR 76 62 78 63 / 40 30 20 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...COLSON/GITTINGER
PREVIOUS DISCUSSION...GLITTO/PENDERGRAST
AREA FORECAST DISCUSSION
NWS MIAMI FL
920 AM EST THU FEB 6 2014
.UPDATE...
A STALLED FRONTAL BOUNDARY WAS LOCATED FROM NEAR FORT MYERS
NORTHEASTWARD THROUGH VERO BEACH THIS MORNING. DENSE FOG FORMED
SOUTH OF THIS BOUNDARY...WITH VISIBILITIES 1/4 MILE OR LESS ACROSS
MUCH OF THE WESTERN INTERIOR. THE FOG IS BEGINNING TO LIFT AND THE
DENSE FOG ADVISORY WAS ALLOWED TO EXPIRE FOR THE LAND AND WATER
AREAS AT 9 AM. DENSE FOG DEVELOPED OVER THE LOCAL GULF WATERS
WEST OF NAPLES LAST NIGHT. BEACH CAMS SHOW SOME FOG STILL
REMAINS...SO WILL KEEP PATCHY FOG IN THE FORECAST FOR THE GULF
WATERS THROUGHOUT THE DAY. DENSE FOG COULD REDEVELOP OVER THE
WATER THIS EVENING.
THE SURFACE BOUNDARY IS FORECAST TO REMAIN NEARLY STATIONARY
TODAY...AND SHOWERS AND A FEW THUNDERSTORMS ARE FORECAST TO
DEVELOP ALONG AND SOUTH OF THIS BOUNDARY. THE BEST CHANCE OF
SHOWERS AND STORMS IS ACROSS THE INTERIOR THIS AFTERNOON...WITH
SOME SHOWERS POSSIBLY MOVING INTO THE METRO AREAS OF PALM BEACH
AND BROWARD COUNTIES AS WELL. THE GLOBAL MODELS AS WELL AS THE
LOCAL WRF MODELS AND HRRR ARE ALL IN GOOD AGREEMENT ON THIS
SCENARIO THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 628 AM EST THU FEB 6 2014/
AVIATION...
KAPF WILL SLOWLY COME OUT OF THE IFR CONDITIONS BY 14Z THIS
MORNING DUE TO THE FOG BURNING OFF. REST OF THE TAF SITES WILL BE
IN THE VFR CONDITIONS TODAY. SHOWERS/TSTORMS LOOK TO FOCUS OVER
THE INTERIOR THIS AFTERNOON. KPBI STANDS THE BETTER CHANCE OF A
FEW SHRA/TSRA MOVING IN FROM THE WEST LATE THIS AFTERNOON SO
INCLUDED VCTS THERE. BNB
PREV DISCUSSION... /ISSUED 310 AM EST THU FEB 6 2014/
.ABOVE NORMAL TEMPERATURES CONTINUE THROUGH THE WEEKEND OVER SOUTH FLORIDA...
.PATCHY TO AREAS OF FOG EACH NIGHT THROUGH THE WEEKEND...
SHORT TERM...
FOG HAS DEVELOPED EARLY THIS MORNING OVER THE WESTERN AREAS OF
SOUTH FLORIDA WITH ISOLATED AREAS OF DENSE FOG. THE FOG SHOULD
CONTINUE OVER THE WESTERN AREAS THROUGH SUNRISE WHILE SPREADING
INTO THE EASTERN INTERIOR AREAS OF SOUTH FLORIDA. SO A DENSE FOG
ADVISORY HAS BEEN ISSUED FOR THE WESTERN AREAS OF SOUTH FLORIDA
THROUGH 9 AM EDT THIS MORNING...AND WE WILL CONTINUE TO MONITOR
THE EASTERN INTERIOR AREAS OF SOUTH FLORIDA THROUGH THE EARLY
MORNING HOURS TO SEE IF THE DENSE FOG ADVISORY NEEDS TO BE
EXPANDED EASTWARD.
A COLD FRONT OVER CENTRAL FLORIDA WILL CONTINUE TO MOVE SLOWLY
SOUTH TODAY...BEFORE STALLING OVER THE LAKE OKEECHOBEE REGION
TONIGHT. THIS WILL KEEP THE WIND FLOW OVER SOUTH FLORIDA IN A
SOUTHERLY DIRECTION TODAY ALONG WITH THE EAST AND WEST COAST SEA
BREEZES DEVELOPING AND PUSHING INLAND. SO THE BEST COVERAGE OF
SHOWERS WILL BE OVER THE INTERIOR AREAS TODAY ALONG WITH A FEW
STORMS LATE THIS AFTERNOON. THERE COULD ALSO BE A FEW STORMS OVER
METRO PALM BEACH COUNTY LATE THIS AFTERNOON INTO EARLY THIS
EVENING...AS THE STEERING FLOW WILL BECOME MORE SOUTHWEST AHEAD OF
THE FRONT.
FOG IS AGAIN POSSIBLE TONIGHT OVER MOST OF SOUTH FLORIDA WITH EVEN
SOME DENSE FOG POSSIBLE OVER THE INTERIOR AND WEST COAST METRO
AREAS...DUE TO THE FRONT NEARBY AND THE LIGHT SOUTH TO SOUTHWEST
STEERING FLOW. SO HAVE PUT IN FOG WORDING OVER MOST OF SOUTH FLORIDA
FOR LATE TONIGHT INTO EARLY FRIDAY MORNING WITH EVEN ISOLATED DENSE
FOG OVER THE INTERIOR AND WEST COAST METRO AREAS.
THE STATIONARY FRONT OVER LAKE OKEECHOBEE REGION WILL MOVE BACK
NORTHWARD INTO NORTHERN FLORIDA ON FRIDAY...AS A WEAK LOW
PRESSURE DEVELOPS OVER THE NORTHERN GULF OF MEXICO. THIS WILL
ALLOW FOR THE STEERING FLOW TO BE SOUTHEAST OVER SOUTH FLORIDA ON
FRIDAY BRINGING IN SOME DRIER AIR TO THE AREA FROM THE BAHAMA
ISLANDS. SO THE ONLY AREA THAT WILL SEE A SLIGHT CHANCE OF SHOWERS
WILL BE OVER THE INTERIOR AND WEST COAST METRO AREAS ON FRIDAY.
THE WEAK LOW WILL MOVE NORTHEAST ACROSS NORTHERN FLORIDA ON
SATURDAY BEFORE MOVING INTO THE WESTERN ATLANTIC WATERS ON SUNDAY.
THIS WILL ALLOW FOR THE WARM FRONT TO BECOME A COLD FRONT AND MOVE
SOUTH THROUGH SOUTH FLORIDA ON SUNDAY. SO THE SLIGHT CHANCE OF
SHOWERS WILL CONTINUE OVER SOUTH FLORIDA THIS WEEKEND...EXCEPT FOR
A CHANCE OF SHOWERS AROUND THE LAKE OKEECHOBEE REGION ON SATURDAY.
HIGHS THROUGH THIS WEEKEND WILL BE IN THE LOWER TO MID 80S WITH
LOWS IN THE 60S...EXCEPT AROUND 70 ALONG THE EAST COAST METRO
AREAS. THESE HIGHS AND LOWS ARE ABOUT 5 TO 10 DEGREES ABOVE THE
AVERAGE FOR THIS TIME OF YEAR. THE HEAT INDEX WILL ALSO BE RUNNING
IN THE MID 80S TO AROUND 90 DEGREES THIS WEEKEND.
LONG TERM...
DRY AND MORE COMFORTABLE WEATHER WILL RETURN TO SOUTH FLORIDA EARLY
NEXT WEEK BEHIND THE PASSAGE OF THE COLD FRONT LATE THIS WEEKEND.
HOWEVER...THE DRY AND COMFORTABLE WEATHER WILL NOT LAST LONG AS
ANOTHER LOW PRESSURE WILL DEVELOP OVER THE NORTHWEST GULF OF
MEXICO AND MOVE NORTHEAST ACROSS THE SOUTHEASTERN UNITED STATES BY
MIDDLE OF NEXT WEEK. THIS IN TURN WILL BRING THE WINDS BACK TO A
SOUTHERLY DIRECTION AND BRING IN THE MOISTURE FROM THE SOUTH BY THE
MIDDLE OF NEXT WEEK. THERE WILL ALSO BE A 20 TO 30 PERCENT CHANCE OF
SHOWERS OVER THE AREA MIDDLE OF NEXT WEEK.
AVIATION...
KAPF JUST WENT DOWN TO 1/4SM FG AND LOOKS AS THOUGH
THIS MAY HANG IN ALL NIGHT SO KEPT THIS CONDITION GOING. ELSEWHERE
THE THINKING IS THAT LOW CLOUDINESS WILL DEVELOP IN MVFR CATEGORY.
WILL HAVE TO KEEP AN EYE OUT FOR POSSIBLE IFR AS WELL, BUT GIVEN
UNCERTAINTIES MAINTAINED MVFR EAST COAST SITES. POSSIBLE
IMPROVEMENT DURING THE DAY, BUT MVFR COULD HANG ON THROUGHOUT THE
DAY...ESPECIALLY AT KAPF. SHOWERS/TSTORMS LOOK TO FOCUS OVER THE
INTERIOR THIS AFTERNOON. KPBI STANDS THE BETTER CHANCE OF A FEW
SHRA/TSRA MOVING IN FROM THE WEST LATE THIS AFTERNOON SO INCLUDED
VCTS THERE. /GREGORIA
MARINE...
THE WINDS WILL REMAIN BELOW 10 KNOTS TODAY INTO THIS WEEKEND WHILE
SLOWLY REMAINING IN A SOUTHERLY DIRECTION. THIS WILL KEEP THE SEAS
BELOW 6 FEET TODAY INTO THIS WEEKEND IN BOTH THE ATLANTIC AND GULF
WATERS. SO BOATING CONDITIONS SHOULD BE GOOD THIS WEEKEND OUTSIDE
OF ANY SHOWERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 67 82 68 / 30 30 10 10
FORT LAUDERDALE 82 70 83 72 / 20 20 10 10
MIAMI 83 71 84 71 / 20 20 10 10
NAPLES 81 63 82 64 / 20 20 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...84/AK
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
931 PM EST FRI FEB 7 2014
.UPDATE...
HIGH PRESSURE CONTINUES AT THE SURFACE TONIGHT. HOWEVER...AN UPPER
LEVEL DISTURBANCE WILL MOVE INTO THE DEEP SOUTH OVERNIGHT AND
EARLY SATURDAY. PRECIPITATION HAS ALREADY DEVELOPED ACROSS THE
ARKLATEX...AND WILL GRADUALLY SPREAD EASTWARD TOWARDS MORNING. 00Z
NAM SOUNDINGS DO MOISTEN UP THE MID AND UPPER COLUMN...BUT KEEP
THE LOWER LEVELS DRY. HOWEVER...LOW DEWPOINT DEPRESSIONS ALREADY
EXIST IN THE SOUTH. SO...THINK BEST CHANCES OF PRECIP WILL REMAIN
JUST SOUTH OF THE ATL METRO. THE LATEST RUNS OF THE HRRR ALSO KEEP
THE PRECIP FURTHER SOUTH.
NO CHANGES TO POPS/TEMPS NEEDED. THE FORECAST LOOKS ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 633 PM EST FRI FEB 7 2014/
PREV DISCUSSION... /ISSUED 330 PM EST FRI FEB 7 2014/
.PATCHY BLACK ICE POSSIBLE FOR PORTIONS OF NORTH GEORGIA DUE TO
LIGHT RAIN AND SNOW MIX TONIGHT INTO EARLY SATURDAY...
SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
MAIN CONCERN FOR THE SHORT TERM IS THE OVERNIGHT PERIOD TONIGHT AS A
DISTURBANCE MOVES ACROSS THE DEEP SOUTH. OVERALL MODELS CONTINUE TO
SUGGEST THAT THE BEST MOISTURE WILL BE ACROSS CENTRAL GEORGIA...AND
SO HAVE CONTINUED WITH THE OVERALL FORECAST TREND OF KEEPING THE
GREATER RAIN CHANCES AND HIGHEST QPF ACROSS THAT AREA. MODELS SHOW
THAT LIGHT RAIN WILL MOVE IN FROM THE SOUTHWEST INTO WESTERN GEORGIA
AROUND MIDNIGHT...AND WILL EXIT THE MAJORITY OF THE FORECAST AREA
8-9AM SATURDAY WITH THE REMAINDER OF THE FORECAST AREA RAIN-FREE BY
THE AFTERNOON. DRY MODEL SOUNDINGS SUGGEST THAT INITIALLY THE PRECIPITATION
WILL BE VIRGA...AND THAT AS THE ATMOSPHERIC COLUMN MOISTENS...WILL
GRADUALLY SEE PRECIP MAKING IT TO THE SURFACE. CLOUD COVER WILL KEEP
TEMPERATURES FROM DROPPING SIGNIFICANTLY...BUT STILL EXPECT PORTIONS
OF NORTH AND WESTERN GEORGIA TO DROP TO NEAR FREEZING OR SLIGHTLY
BELOW. THERE IS A POSSIBILITY OF LIGHT RAIN MIXING WITH LIGHT
SNOW...BUT AS PREVIOUSLY MENTIONED...THE AREAS THAT HAVE A
TEMPERATURE PROFILE WOULD SUPPORT WINTER PRECIPITATION ARE NOT THE
AREAS THAT HAVE THE BEST MOISTURE. AT THIS TIME...DO NOT EXPECT ANY
ACCUMULATIONS.
IF PRECIPITATION IS ENOUGH TO WET SURFACES ACROSS FAR NORTH
GEORGIA...WHERE LOWS WILL BE AT OR BELOW FREEZING...VERY PATCHY
BLACK ICE WILL BE A CONCERN. ADDITIONAL INFORMATION ON POTENTIAL
IMPACTS CAN BE FOUND IN THE LATEST SPECIAL WEATHER STATEMENT
/SPSFFC/.
CLEARING CONDITIONS ARE EXPECTED THROUGH THE SHORT TERM. HAVE
GENERALLY GONE WITH A MODEL BLEND FOR THE TEMPERATURES...WITH MID
50S TO LOW 60S FOR HIGHS SATURDAY...AND SIMILAR LOW TEMPERATURES
AGAIN SUNDAY MORNING.
31
LONG TERM /SUNDAY THROUGH FRIDAY/...
ONLY MINOR ADJUSTMENTS MADE TO PREVIOUS FORECAST AS IT LOOKS TO BE
LARGELY ON TRACK. SOME INDICATION FOR LIGHT SNOW POTENTIAL IN
PORTIONS OF NORTH GEORGIA MONDAY NIGHT BUT WILL MONITOR FOR
CONSISTENCY TO INCLUDE IN FUTURE UPDATES. PREVIOUS DISCUSSION
FOLLOWS...
BAKER
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
/ISSUED AT 350 AM EST FRI FEB 7 2014/
NO EASY FORECASTING FOR THE LONG TERM AS MODEL DIFFERENCES AND COLD
OVERNIGHT TEMPERATURES OVER N GA MAKE PRECIP TYPE DIFFICULT TO
FORECAST.
MODELS CONSISTENT MOVING A SHORT WAVE ACROSS THE AREA SATURDAY NIGHT
WITH MINIMAL MOISTURE ASSOCIATED BUT COULD CAUSE SOME SPRINKLES OR
FLURRIES OVER MAINLY N GA.
SUNDAY LOOKS DRY HOWEVER THE EUROPEAN DOES BRING IN SOME MOISTURE
ACROSS N GA ASSOCIATED WITH A SHORT WAVE WHILE THE GFS IS DRY. A
WEAK BACK DOOR COLD FRONT WILL MOVE TO N GA AS WELL.
EUROPEAN WETTER ON MONDAY SPREADING MOISTURE AND PRECIP CHANCES
ACROSS THE AREA WHILE THE GFS IS DRY WITH MOISTURE MOVING ACROSS THE
N. FOR NOW KEPT SMALL RAIN CHANCES ACROSS THE N. BOTH MODELS
INDICATING MOISTURE ACROSS THE AREA THROUGH TUESDAY WITH THE GFS NOW
WETTER. OVERNIGHT TEMPERATURES MONDAY NIGHT COULD CAUSE A RAIN
SNOW OR EVEN SLEET MIX. PRECIP CHANCES INCREASE TUESDAY NIGHT AND
WEDNESDAY FAVORING THE EUROPEAN MODEL WITH A CAD AIRMASS AND
OVERRUNNING SCENARIO SETTING UP AND PRODUCING A COLD RAIN.
HOWEVER...TEMPERATURES ARE CLOSE TUESDAY NIGHT FOR SOME TYPE OF
WINTER MIX FAVORING SNOW AND FREEZING RAIN FOR A FEW OF THE FAR
NORTHERN COUNTIES. SURFACE LOW PRESSURE MOVES TO E COAST THURSDAY
MORNING GREATLY DIMINISHING PRECIP CHANCES ACROSS THE AREA. ONCE
AGAIN TEMPERATURES CLOSE WEDNESDAY NIGHT FOR SOME TYPE OR MIX
FAVORING RAIN AND SNOW.
BDL
AVIATION...
00Z UPDATE...
AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE CWFA LATER
TONIGHT/EARLY SATURDAY. PRECIPITATION IS EXPECTED TO SPREAD ACROSS
PORTIONS OF CENTRAL AND SOUTHERN GA OVERNIGHT. LATEST RUNS OF THE
HRRR KEEP AXIS OF HEAVIER PRECIP TO THE SOUTH. SOME LIGHT PRECIP
IS POSSIBLE BEFORE 12Z AT ATL...BUT NO REAL CIG/VSBY RESTRICTIONS
ANTICIPATED.
//ATL CONFIDENCE...00Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 54 36 59 37 / 0 50 40 5
ATLANTA 50 37 57 39 / 5 40 30 5
BLAIRSVILLE 46 32 51 32 / 5 30 30 5
CARTERSVILLE 48 32 56 32 / 5 30 20 5
COLUMBUS 55 39 59 38 / 5 70 60 5
GAINESVILLE 49 36 54 38 / 5 30 30 5
MACON 56 37 60 37 / 5 80 70 5
ROME 47 30 54 31 / 5 30 20 5
PEACHTREE CITY 52 34 58 33 / 5 60 50 5
VIDALIA 59 44 60 43 / 5 80 70 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
638 AM EST THU FEB 6 2014
.SYNOPSIS...
HIGH PRESSURE WILL BE CENTERED NORTH AND WEST OF THE FORECAST
AREA THROUGH FRIDAY. AN UPPER-LEVEL DISTURBANCE WILL BRING
ENHANCED CLOUDINESS TONIGHT. LOW PRESSURE WILL DEVELOP OFF THE
SOUTHEAST COAST SATURDAY AND SHOULD HAVE LIFTED WELL NORTHEAST OF
THE AREA BY SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...THE LOWER LEVELS OF THE ATMOSPHERE WILL REMAIN DRY
TODAY. THE SURFACE HIGH CENTERED WELL TO OUR WEST WILL DIRECT A
DRY NORTHERLY FLOW INTO OUR AREA. HOWEVER...THERE WILL BE MID AND
HIGH CLOUDINESS IN THE WEST-SOUTHWEST FLOW ASSOCIATED WITH THE
BROAD TROUGH. LIFT AHEAD OF A MID-LEVEL SHORTWAVE TROUGH COULD
HELP SUPPORT LIGHT RAIN TOWARD THE END OF THE DAY IN THE SOUTH
PART. THE 08Z HRRR INDICATED SPOTTY AREAS OF RAIN IN THE CENTRAL
SAVANNAH RIVER AREA BEGINNING AROUND 22Z. THE TEMPERATURE
GUIDANCE WAS CLOSE WITH HIGHS NEAR 50 NORTH TO THE MIDDLE 50S
SOUTHEAST.
TONIGHT...THE MODELS INDICATE LIFT ASSOCIATED WITH A SHORTWAVE
TROUGH MAINLY EARLY TONIGHT. MOISTURE WILL BE LIMITED WITH H85
WESTERLY FLOW AND NEUTRAL THERMAL ADVECTION. THE PRECIPITATION
CHANCE APPEARS LOW. KEPT SLIGHT CHANCE POPS MAINLY IN THE SOUTH
PART WHICH SHOULD BE CLOSER TO A LITTLE DEEPER MOISTURE. THE NAM
AND GFS ARE CONSISTENT KEEPING SURFACE TEMPERATURES ABOVE FREEZING
DURING THIS TIME. DRYING AND COLD ADVECTION BEHIND THE SHORTWAVE
TROUGH SUPPORTS TEMPERATURES FALLING BELOW FREEZING TOWARD
SUNRISE. THE TEMPERATURE GUIDANCE WAS CLOSE WITH LOWS IN THE UPPER
20S AND LOWER 30S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THE NAM AND GFS ARE CONSISTENT SHOWING A DRY AIR MASS REMAINING IN
PLACE FRIDAY AND FRIDAY EVENING. MOISTURE WILL BE ON THE INCREASE
LATE FRIDAY NIGHT ASSOCIATED WITH LOW PRESSURE DEVELOPING OFF THE
SOUTHEAST COAST. THE NAM AND GFS SHOW THIS FEATURE LIFTING
NORTHEAST OF THE FORECAST AREA SATURDAY AND SATURDAY NIGHT. THE
MODELS SHOW DEEPER MOISTURE AND ISENTROPIC LIFT CONFINED TO THE
EASTERN PART OF THE FORECAST AREA SATURDAY MORNING. WE FORECASTED
LIKELY POPS IN THE EAST PART WITH JUST CHANCE ELSEWHERE DURING
THAT TIME. MODEL TIME-HEIGHT DISPLAYS SUPPORT LIQUID PRECIPITATION.
EXPECT DRYING BEHIND THE SYSTEM FOR SATURDAY AFTERNOON AND NIGHT.
USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF DISPLAY A DRY PATTERN SUNDAY THROUGH MONDAY WITH H85
WESTERLY FLOW AND COLD OR NEUTRAL THERMAL ADVECTION DOMINATING.
THE MODELS SHOW A WEDGE-RIDGE PATTERN TUESDAY AND WEDNESDAY WITH A
DEVELOPING SIGNIFICANT UPPER-LEVEL TROUGH AND ASSOCIATED LOW
PRESSURE SYSTEM. THE MODELS HAVE NOT BEEN CONSISTENT WITH THE
TIMING OF THIS SYSTEM BUT THE 00Z GFS AND ECMWF DO INDICATE DEEP
MOISTURE WEDNESDAY WITH LOW PRESSURE NEARING THE FORECAST AREA.
THERE IS A POSSIBILITY OF ENOUGH COLD AIR ASSOCIATED WITH THE
WEDGE PATTERN FOR WINTER-TYPE PRECIPITATION MAINLY IN THE NORTH
PART.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS EXPECTED THROUGH THE TAF FORECAST PERIOD.
HIGH PRESSURE WILL REMAIN OVER THE AREA TODAY WITH RIPPLES OF ENERGY
IN SOUTHWEST FLOW ALOFT CAUSING BKN/OVC MIDDLE AND HIGH-LEVEL CLOUDS
FOR MUCH OF THE TAF PERIOD. WINDS WILL GRADUALLY SHIFT TO
NORTHEASTERLY MAINLY AFTER 13Z THIS MORNING. A FEW SPRINKLES MAY BE
POSSIBLE LATE THIS AFTERNOON INTO THE EVENING HOURS MAINLY AT
AGS/DNL/OGB...BUT NOT ENOUGH CONFIDENCE TO MENTION IN THE TAFS AT
THIS TIME. CIGS WILL REMAIN VFR TODAY INTO TONIGHT BUT MAY BECOME
MORE SCT/BKN TOWARDS THE END OF THE PERIOD.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE FRIDAY NIGHT INTO
SATURDAY AS ANOTHER SYSTEM.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
226 PM CST THU FEB 6 2014
.DISCUSSION...
952 AM CST
WE WILL BE LETTING THE WIND CHILL ADVISORY FOR THIS MORNING EXPIRE
AT 10 AM. SEVERAL SITES OUT WEST ARE STILL HOVERING RIGHT AROUND
-20 FOR THE WIND CHILL...BUT THESE AREAS SHOULD IMPROVE SOME INTO
NEXT HOUR OR TWO...AND WE FELT THAT IT WAS NOT WORTH EXTENDING THE
ADVISORY FOR ANOTHER HOUR OR TWO. OTHERWISE...NO MAJOR CHANGES TO
THE GOING FORECAST. WE WILL ASSES THE NEED TO EXPAND THE WIND
CHILL ADVISORY FOR TONIGHT INTO FRIDAY ACROSS THE REST OF THE AREA
WITH THE AFTERNOON PACKAGE.
KJB
//PREV DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NONE.
KREIN
//DISCUSSION...UPDATED 18Z...
QUIET WEATHER FOR THE AVIATION COMUNITY WILL CONTINUE THROUGH THE
PERIOD. WITH HIGH PRESSURE BUILDING ACTOSS THE MIDDLE MISSISSIPPI
VALLEY THROUGH THE OHIO VALLEY...SKIES ARE MOSTLY CLEAR WITH ONLY
A FEW FRAGMENTS OF STRATOCU OR CIRRUS. WINDS WILL BE OUT OF THE
WEST THROUGH THE REMAINDER OF THE DAY BEFORE GRADUALLY BACKING A
LITTLE MORE SWLY THROUGH THE EVENING AND OVERNIGHT. AMPLE SUNSHINE
WILL ALLOW FOR SOME MIXING THROUGH THE DAYTIME HOURS...SO...WILL
MAINTAIN THE GUSTS IN THE UPPER TEENS. SOME MID LEVEL MOISTURE IS
EXPECTION TO OVERSPREAD THE REGION TONIGHT...BRINGING SOME SCT-BKN
WITH BASES AT 8KFT-10KFT...BUT NOTHING OPERATIONALLY SIGNIFICANT.
CONDITIONS TOMORROW WILL CONTINUE TO BE QUIET...WITH SWLY WINDS
AND MOSTLY CLEAR SKIES.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
224 PM CST
BROAD SURFACE RIDGE EXTENDS FROM THE OHIO VALLEY WEST THROUGH THE
CENTRAL PLAINS...AND WILL REMAIN ORIENTED ACROSS THIS AREA THROUGH
THE NEXT 24 HOURS. THIS FEATURE COMBINED WITH A LOW PRESSURE WELL
NORTH ACROSS HUDSON BAY WILL CREATE A WESTERLY GRADIENT ACROSS THE
LAKE AND PRODUCE WINDS TO 30 KT OVERNIGHT THROUGH FRIDAY BEFORE THIS
GRADIENT WEAKENS. AS A RESULT OF THE INCREASED WINDS TONIGHT THROUGH
FRIDAY OVER THE NORTHERN PORTIONS OF THE LAKE...FREEZING SPRAY IS
LIKELY FOR THE ICE FREE AREAS. FOR THE NEARSHORE WATERS THE WINDS
HAVE BEEN HOVERING AROUND SMALL CRAFT CONDITIONS...HOWEVER IT
APPEARS THE WINDS WILL DIMINISH SLIGHTLY THIS EVENING TO COME BACK
DOWN TO 15 TO 25 KT. SO WILL NOT BE ISSUING ANY HEADLINES AT THIS
TIME. THE RIDGE WILL BEGIN TO DRIFT EAST TOWARDS NEW ENGLAND
SATURDAY...WHILE A TROUGH OF LOW PRESSURE BEGINS TO PULL EAST OF
THE CENTRAL ROCKIES SATURDAY MORNING. THIS LOW IS THEN EXPECTED TO
LIFT NORTHEAST TOWARDS THE WESTERN GREAT LAKES SATURDAY AFTERNOON.
THIS LOW WILL THEN LIFT NORTHEAST TO THE EASTERN LAKES MIDDAY
SUNDAY AND ALLOW A TIGHTENING GRADIENT AND NORTHWEST FLOW TO
RETURN FOR LAKE MICHIGAN.
ANOTHER RIDGE OF HIGH PRESSURE WILL RETURN EARLY NEXT WEEK FOR THE
GREAT LAKES...WITH LIGHT FLOW RETURNING AS WELL.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039...6 PM THURSDAY TO 11 AM FRIDAY.
IN...WIND CHILL ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...6 PM
THURSDAY TO 11 AM FRIDAY.
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
NWS CHICAGO/ROMEOVILLE IL
137 PM CST THU FEB 6 2014
.DISCUSSION...
952 AM CST
WE WILL BE LETTING THE WIND CHILL ADVISORY FOR THIS MORNING EXPIRE
AT 10 AM. SEVERAL SITES OUT WEST ARE STILL HOVERING RIGHT AROUND
-20 FOR THE WIND CHILL...BUT THESE AREAS SHOULD IMPROVE SOME INTO
NEXT HOUR OR TWO...AND WE FELT THAT IT WAS NOT WORTH EXTENDING THE
ADVISORY FOR ANOTHER HOUR OR TWO. OTHERWISE...NO MAJOR CHANGES TO
THE GOING FORECAST. WE WILL ASSES THE NEED TO EXPAND THE WIND
CHILL ADVISORY FOR TONIGHT INTO FRIDAY ACROSS THE REST OF THE AREA
WITH THE AFTERNOON PACKAGE.
KJB
//PREV DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NONE.
KREIN
//DISCUSSION...UPDATED 18Z...
QUIET WEATHER FOR THE AVIATION COMUNITY WILL CONTINUE THROUGH THE
PERIOD. WITH HIGH PRESSURE BUILDING ACTOSS THE MIDDLE MISSISSIPPI
VALLEY THROUGH THE OHIO VALLEY...SKIES ARE MOSTLY CLEAR WITH ONLY
A FEW FRAGMENTS OF STRATOCU OR CIRRUS. WINDS WILL BE OUT OF THE
WEST THROUGH THE REMAINDER OF THE DAY BEFORE GRADUALLY BACKING A
LITTLE MORE SWLY THROUGH THE EVENING AND OVERNIGHT. AMPLE SUNSHINE
WILL ALLOW FOR SOME MIXING THROUGH THE DAYTIME HOURS...SO...WILL
MAINTAIN THE GUSTS IN THE UPPER TEENS. SOME MID LEVEL MOISTURE IS
EXPECTION TO OVERSPREAD THE REGION TONIGHT...BRINGING SOME SCT-BKN
WITH BASES AT 8KFT-10KFT...BUT NOTHING OPERATIONALLY SIGNIFICANT.
CONDITIONS TOMORROW WILL CONTINUE TO BE QUIET...WITH SWLY WINDS
AND MOSTLY CLEAR SKIES.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
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
NWS CHICAGO/ROMEOVILLE IL
1212 PM CST THU FEB 6 2014
.DISCUSSION...
952 AM CST
WE WILL BE LETTING THE WIND CHILL ADVISORY FOR THIS MORNING EXPIRE
AT 10 AM. SEVERAL SITES OUT WEST ARE STILL HOVERING RIGHT AROUND
-20 FOR THE WIND CHILL...BUT THESE AREAS SHOULD IMPROVE SOME INTO
NEXT HOUR OR TWO...AND WE FELT THAT IT WAS NOT WORTH EXTENDING THE
ADVISORY FOR ANOTHER HOUR OR TWO. OTHERWISE...NO MAJOR CHANGES TO
THE GOING FORECAST. WE WILL ASSES THE NEED TO EXPAND THE WIND
CHILL ADVISORY FOR TONIGHT INTO FRIDAY ACROSS THE REST OF THE AREA
WITH THE AFTERNOON PACKAGE.
KJB
//PREV DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* NONE.
KREIN
//DISCUSSION...UPDATED 18Z...
QUIET WEATHER FOR THE AVIATION COMUNITY WILL CONTINUE THROUGH THE
PERIOD. WITH HIGH PRESSURE BUILDING ACTOSS THE MIDDLE MISSISSIPPI
VALLEY THROUGH THE OHIO VALLEY...SKIES ARE MOSTLY CLEAR WITH ONLY
A FEW FRAGMENTS OF STRATOCU OR CIRRUS. WINDS WILL BE OUT OF THE
WEST THROUGH THE REMAINDER OF THE DAY BEFORE GRADUALLY BACKING A
LITTLE MORE SWLY THROUGH THE EVENING AND OVERNIGHT. AMPLE SUNSHINE
WILL ALLOW FOR SOME MIXING THROUGH THE DAYTIME HOURS...SO...WILL
MAINTAIN THE GUSTS IN THE UPPER TEENS. SOME MID LEVEL MOISTURE IS
EXPECTION TO OVERSPREAD THE REGION TONIGHT...BRINGING SOME SCT-BKN
WITH BASES AT 8KFT-10KFT...BUT NOTHING OPERATIONALLY SIGNIFICANT.
CONDITIONS TOMORROW WILL CONTINUE TO BE QUIET...WITH SWLY WINDS
AND MOSTLY CLEAR SKIES.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
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
NWS CHICAGO/ROMEOVILLE IL
1001 AM CST THU FEB 6 2014
.DISCUSSION...
952 AM CST
WE WILL BE LETTING THE WIND CHILL ADVISORY FOR THIS MORNING EXPIRE
AT 10 AM. SEVERAL SITES OUT WEST ARE STILL HOVERING RIGHT AROUND
-20 FOR THE WIND CHILL...BUT THESE AREAS SHOULD IMPROVE SOME INTO
NEXT HOUR OR TWO...AND WE FELT THAT IT WAS NOT WORTH EXTENDING THE
ADVISORY FOR ANOTHER HOUR OR TWO. OTHERWISE...NO MAJOR CHANGES TO
THE GOING FORECAST. WE WILL ASSES THE NEED TO EXPAND THE WIND
CHILL ADVISORY FOR TONIGHT INTO FRIDAY ACROSS THE REST OF THE AREA
WITH THE AFTERNOON PACKAGE.
KJB
//PREV DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* NONE.
KREIN
//DISCUSSION...UPDATED 12Z...
A FAIRLY QUIET WEATHER DAY ON TAP WITH VFR CONDITIONS AND WEST FLOW
PREVAILING. SOME LINGERING FLURRIES AND MVFR CIGS PERSIST OVER
PORTIONS OF THE CHICAGO METRO THIS MORNING BUT ARE PROGGED TO MOVE
OUT EARLY THIS MORNING. RAP 900-925 RH HAS HAD A DECENT HANDLE ON
THE PROGRESSION THIS MORNING AND INDICATES CLEARING SHORTLY. THERE
MAY BE SOME COLD AIR CU THAT REDEVELOPS TODAY BETWEEN 020-025...BUT
ANTICIPATE IT BEING FEW TO SCT IN COVERAGE IF IT EVEN DEVELOPS.
GUSTS WILL ALSO PICK UP LATER IN THE MORNING THROUGH THE
AFTERNOON...INTO THE MID POSSIBLY UPPER TEENS. WINDS WILL TAPER
AGAIN IN THE EVENING AROUND SUNSET.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032 UNTIL 10 AM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
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
NWS CHICAGO/ROMEOVILLE IL
956 AM CST THU FEB 6 2014
.DISCUSSION...
952 AM CST
WE WILL BE LETTING THE WIND CHILL ADVISORY FOR THIS MORNING EXPIRE
AT 10 AM. SEVERAL SITES OUT WEST ARE STILL HOVERING RIGHT AROUND
-20 FOR THE WIND CHILL...BUT THESE AREAS SHOULD IMPROVE SOME INTO
NEXT HOUR OR TWO...AND WE FELT THAT IT WAS NOT WORTH EXTENDING THE
ADVISORY FOR ANOTHER HOUR OR TWO. OTHERWISE...NO MAJOR CHANGES TO
THE GOING FORECAST. WE WILL ASSES THE NEED TO EXPAND THE WIND
CHILL ADVISORY FOR TONIGHT INTO FRIDAY ACROSS THE REST OF THE AREA
WITH THE AFTERNOON PACKAGE.
KJB
&&
.PREV DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* NONE.
KREIN
//DISCUSSION...UPDATED 12Z...
A FAIRLY QUIET WEATHER DAY ON TAP WITH VFR CONDITIONS AND WEST FLOW
PREVAILING. SOME LINGERING FLURRIES AND MVFR CIGS PERSIST OVER
PORTIONS OF THE CHICAGO METRO THIS MORNING BUT ARE PROGGED TO MOVE
OUT EARLY THIS MORNING. RAP 900-925 RH HAS HAD A DECENT HANDLE ON
THE PROGRESSION THIS MORNING AND INDICATES CLEARING SHORTLY. THERE
MAY BE SOME COLD AIR CU THAT REDEVELOPS TODAY BETWEEN 020-025...BUT
ANTICIPATE IT BEING FEW TO SCT IN COVERAGE IF IT EVEN DEVELOPS.
GUSTS WILL ALSO PICK UP LATER IN THE MORNING THROUGH THE
AFTERNOON...INTO THE MID POSSIBLY UPPER TEENS. WINDS WILL TAPER
AGAIN IN THE EVENING AROUND SUNSET.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
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
NWS CHICAGO/ROMEOVILLE IL
754 AM CST THU FEB 6 2014
.DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* NONE.
KREIN
//DISCUSSION...UPDATED 12Z...
A FAIRLY QUIET WEATHER DAY ON TAP WITH VFR CONDITIONS AND WEST FLOW
PREVAILING. SOME LINGERING FLURRIES AND MVFR CIGS PERSIST OVER
PORTIONS OF THE CHICAGO METRO THIS MORNING BUT ARE PROGGED TO MOVE
OUT EARLY THIS MORNING. RAP 900-925 RH HAS HAD A DECENT HANDLE ON
THE PROGRESSION THIS MORNING AND INDICATES CLEARING SHORTLY. THERE
MAY BE SOME COLD AIR CU THAT REDEVELOPS TODAY BETWEEN 020-025...BUT
ANTICIPATE IT BEING FEW TO SCT IN COVERAGE IF IT EVEN DEVELOPS.
GUSTS WILL ALSO PICK UP LATER IN THE MORNING THROUGH THE
AFTERNOON...INTO THE MID POSSIBLY UPPER TEENS. WINDS WILL TAPER
AGAIN IN THE EVENING AROUND SUNSET.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032 UNTIL 10 AM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
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
NWS CHICAGO/ROMEOVILLE IL
531 AM CST THU FEB 6 2014
.DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* NONE
BMD
//DISCUSSION...UPDATED 12Z...
A FAIRLY QUIET WEATHER DAY ON TAP WITH VFR CONDITIONS AND WEST FLOW
PREVAILING. SOME LINGERING FLURRIES AND MVFR CIGS PERSIST OVER
PORTIONS OF THE CHICAGO METRO THIS MORNING BUT ARE PROGGED TO MOVE
OUT EARLY THIS MORNING. RAP 900-925 RH HAS HAD A DECENT HANDLE ON
THE PROGRESSION THIS MORNING AND INDICATES CLEARING SHORTLY. THERE
MAY BE SOME COLD AIR CU THAT REDEVELOPS TODAY BETWEEN 020-025...BUT
ANTICIPATE IT BEING FEW TO SCT IN COVERAGE IF IT EVEN DEVELOPS.
GUSTS WILL ALSO PICK UP LATER IN THE MORNING THROUGH THE
AFTERNOON...INTO THE MID POSSIBLY UPPER TEENS. WINDS WILL TAPER
AGAIN IN THE EVENING AROUND SUNSET.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032 UNTIL 10 AM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
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
NWS CHICAGO/ROMEOVILLE IL
300 AM CST THU FEB 6 2014
.DISCUSSION...
324 PM CST
THE MAIN FORECAST CONCERNS WILL BE WITH WIND CHILLS TONIGHT AND
AGAIN THURSDAY NIGHT AS AN ARCTIC SURFACE HIGH DOMINATES ACROSS THE
CENTRAL CONUS.
...HAVE ISSUED A WIND CHILL ADVISORY FOR WESTERN SECTIONS OF THE
AREA FOR LATE TONIGHT THROUGH LATE MORNING THURSDAY...
LAKE EFFECT SNOW SHOWERS CONTINUE ACROSS PORTIONS OF EASTERN
ILLINOIS...ESPECIALLY ACROSS SOUTHERN COOK AND INTO NORTHWESTERN
INDIANA. THIS ACTIVITY WILL WANE QUICKLY OVER THE NEXT COUPLE HOURS
ACROSS NORTHEASTERN ILLINOIS AS THE LAND-LAKE CONVERGENCE ZONE
CONTINUES TO SHIFT RAPIDLY TO THE EAST ACROSS NORTHWESTERN INDIANA.
THE LAKE EFFECT SNOW SHOWERS MAY LINGER FOR A SHORT PERIOD EARLY
THIS EVENING ACROSS PORTIONS OF LAKE AND PORTER COUNTY
INDIANA WITH SOME MINOR ACCUMULATIONS UP TO AN ADDITIONAL INCH
POSSIBLE...BUT THIS ACTIVITY WILL ALSO ABATE BY MID TO LATE EVENING
AS THE FLOW ACROSS THE LAKE BACKS MORE NORTHWESTERLY.
IT APPEARS THAT PERIODS OF VERY LIGHT SNOW SHOWERS AND FLURRIES MAY
CONTINUE TONIGHT ACROSS MUCH OF THE AREA AS THE REGION REMAINS IN A
RATHER DISTURBED MID AND UPPER LEVEL WESTERLY FLOW ALONG THE
NORTHERN FRINGE OF A 110+ KT UPPER LEVEL JET. SEVERAL UPSTREAM OBS
ACROSS IOWA AND MINNESOTA HAVE INDICATED PERIODS OF FLURRIES...AND I
WOULD EXPECT TO TO BE THE CASE ACROSS MUCH OF MY AREA TONIGHT AS
WELL. MODEL BUFFER SOUNDINGS SUGGEST THAT LOWER LEVEL SATURATION
WILL BE SUFFICIENT TO SQUEEZE OUT AT LEAST SOME FLURRIES.
OTHERWISE...AS MENTIONED ABOVE...I ISSUED A WIND CHILL ADVISORY FOR
THE WESTERN HALF OF MY CWA. MY NEIGHBORS TO THE SOUTH AND EAST HAVE
SLIGHTLY LOWER CRITERIA FOR WIND CHILL ADVISORIES...HENCE THE GAP IN
THE ADVISORY ACROSS MY SOUTHEASTERN COUNTIES. I CHOOSE NOT TO PUT
THESE AREAS IN AN ADVISORY DUE TO THE FACT THAT IT DOES NOT APPEAR
TO BE QUITE AS COLD THERE AS PREVIOUSLY THOUGHT DUE TO CLOUD COVER
AND A GRADIENT THAT WILL LIKELY KEEP WINDS UP AROUND 10 MPH FOR MUCH
OF THE NIGHT. FOR THESE REASONS IT WILL BE ADVECTION ALONE AND NOT
RADIATIONAL COOLING THAT WILL LEAD TO THE COLD TEMPERATURES ACROSS
THE AREA. GIVEN THAT THE AIR MASS...WHICH WAS SLIGHTLY COLDER ACROSS
MINNESOTA THIS MORNING PRODUCED LOWS AROUND -5...I THINK THESE
VALUES WILL OCCUR ACROSS MY NORTH CENTRAL ILLINOIS COUNTIES...WITH
VALUES LIKELY NEAR ZERO IN MY SOUTHEASTERN COUNTIES. OVERALL THIS
WILL YIELD WIND CHILLS AS LOW AS -25 NORTH CENTRAL TO AROUND -15
ACROSS MY SOUTHEASTERN COUNTIES. THE EVENING SHIFT CAN WATCH TRENDS
TONIGHT AND EXPAND THE ADVISORY IF NECESSARY.
COLD CONDITIONS WILL CONTINUE ON THURSDAY AS THE 1040 MB SURFACE HIGH
SHIFTS EASTWARD FROM THE PLAINS ACROSS THE LOWER MISSOURI RIVER
VALLEY. THIS COULD YIELD WIND CHILLS IN EXCESS OF -20 ACROSS MOST OF
MY CWA INTO FRIDAY MORNING AS ACTUALLY LOW TEMPS FALL SEVERAL
DEGREES BELOW ZERO.
A STRONG 120+ KT WESTERLY UPPER LEVEL JET WILL DEVELOP ACROSS THE
EASTERN PACIFIC AND ACROSS THE PACIFIC NORTHWEST LATER THIS WEEK AS
THE THE LARGE SCALE WEATHER PATTERN ACROSS THE NORTH PACIFIC SHIFTS.
THIS WILL SET THE STAGE FOR MULTIPLE DISTURBANCES TO EJECT EASTWARD
ACROSS THE PLAINS STATES THROUGH THE EXTENDED PERIOD. IT APPEARS
THAT ONE OF THESE DISTURBANCES MAY TAKE A TRACK EASTWARD IN A
FAVORABLE AREA FOR SOME MORE ACCUMULATING SNOW ACROSS THE AREA ON
SATURDAY. HOWEVER...AT THIS TIME THIS DOES NOT APPEAR TO BE A MAJOR
SNOW MAKER FOR THE AREA.
OTHERWISE...THE REST OF THE EXTENDED PERIOD APPEARS TO REMAIN COLDER
THAN AVERAGE. THERE WILL BE MORE POTENTIALS FOR PRECIPITATION EARLY
TO THE MIDDLE PART OF NEXT WEEK AS THE WEATHER PATTERN REMAINS
ACTIVE. HOWEVER...AT THIS TIME THERE ARE TO MANY UNCERTAINTIES IN HOW
FAR NORTH PRECIPITATION MAY GET...WITH THE POSSIBILITY OF MUCH OF THE
PRECIPITATION BEING LOCK UP TO THE SOUTH OF THE AREA. CONFIDENCE IS
LOW AT THIS TIME...AND ANY NORTHWARD SHIFT IN THE FAVORED TRACK OF
THESE SOUTHERN TRACKED SYSTEMS COULD PRODUCE SNOW INTO NORTHERN
ILLINOIS.
KJB
&&
.CLIMATE...
RECORD COLD HIGHS FOR THURSDAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LIGHT SNOW AND PATCHY MVFR THIS EVENING...TAPERING OVER NEXT
HOUR.
BMD
//DISCUSSION...UPDATED 09Z...
MVFR CIGS/FLURRIES LINGERED LONGER THAN EXPECTED. RAP SEEMS TO
HAVE DECENT HAND ON WHATS GOING ON...AND HAVE EXPANDED TIMING OF
FLURRIES TO BETTER MATCH UP. CIGS ARE GENERALLY IN THE 025-030
RANGE AND DO NOT ANTICIPATE VSBY TO DROP BELOW 6SM.
PREVIOUS DISCUSSION 06Z...
STEEP LOW LEVEL LAPSE RATES OVER THE AREA HAVE RESULTED IN A PATCH OF
CLOUDS MOVING OVER THE AREA WHICH ARE PRODUCING A FEW FLURRIES. THESE
WILL BE SHORT LIVED THOUGH AS THEY PROGRESS EAST ACROSS THE AREA AND
FLAT UPPER LEVEL RIDGING WILL RESULT IN SUBSIDENCE AND DRYING OF THE
AIRMASS...SO DO NOT EXPECT ADDITIONAL DEVELOPMENT OVERNIGHT. WINDS
WILL BE PRIMARILY WESTERLY THOUGH THE PERIOD AS A STRONG HIGH BUILDS
TO THE SOUTH OF THE TERMINALS. GUSTS INTO THE MID TO UPPER TEENS ARE
EXPECTED TO DEVELOP MID TO LATE THURSDAY MORNING...AND END IN THE
EVENING. OUTSIDE OF THE PATCHY MVFR OVER THE NEXT HOUR OR
TWO...EXPECT THE REMAINDER OF THE PERIOD TO BE VFR.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...VFR LIKELY.
SATURDAY...SNOW/MVFR-IFR LIKELY.
SUNDAY THROUGH TUESDAY...VFR LIKELY.
ZEBIC
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032 UNTIL 10 AM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
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
NWS PADUCAH KY
920 PM CST Fri Feb 7 2014
.UPDATE...
ISSUED AT 918 PM CST FRI FEB 7 2014
Mid-evening update to handle adjustment to current Winter Weather
advisory in effect and slight adjustments to weather and PoPs for
the remainder of the first period (tonight) and the first half of
tomorrow (Saturday morning).
&&
.MESOSCALE DISCUSSION...
ISSUED AT 918 CST FRI FEB 7 2014
A WSW-ENE oriented zone of forcing along the northern end of the
current snow shield in Arkansas and western 1/2 of Tennessee is
producing conditional instability within the dendritic growth zone
to support more ice crystal collisions in that layer. The one kilometer
above ground level (AGL) reflectivity fields from 3km HRRR, as
well as the high resolution ARW and NMM versions of the 4km NAM-
WRF numerical models are sampling the current snow production
fairly well this evening. Even the GFS and RAP guidance, through
the isentropic pressure deficits, appear to be handing the timing
of the precipitation reaching the ground in a decent manner.
VAD wind profiles from the Little Rock, Memphis, and Paducah
radars are in line with the elevation of the 20+ DbZ returns
lending credence to the timing of this system.
The main adjustment for this evening was to slow the timing of the
onset of measurable precipitation into southeast Missouri until
10-11 pm CST.
In addition, based on QPF estimates generated from the SREF, GFS,
RAP, and WPC guidance, blended with local forecast adjustments
should keep advisory level snowfall further south toward the
Missouri bootheel and in West Kentucky.
It appears that it will be difficult for snowfall amounts to reach
above an inch north of a Sikeston MO, Paducah and Owensboro
Kentucky line during the advisory, so decided to refine the
advisory and drop the northern tier of counties from the advisory.
Utilized liquid to snowfall ratios near a 17 to 1 at the beginning
of the event up to 21 to 1 by the end of the advisory. This still
places the greatest snowfall amounts overnight south and east of a
line from Cadiz, Crofton, and Greenville, southward to the KY and
TN border.
&&
.SHORT TERM...(This Evening through Sunday night)
ISSUED AT 259 PM CST FRI FEB 7 2014
No changes were made to the going winter weather advisory. Models
are in decent agreement keeping the focus of any accumulating
snowfall across west Kentucky and southern portions of southeast
Missouri. Overall liquid amounts will be fairly light, but with 15:1
to 18:1 snow ratios expected, 1 to 2 inch accumulations are
possible, especially across the Pennyrile region of west Kentucky
and along the Kentucky/Tennessee border. KLZK radar is already
showing some weak returns in northeast Arkansas and west
Tennessee. Expect light snow to reach/develop in southeast
Missouri late afternoon/early evening and spread east through the
evening hours, with the best accumulation times from late evening
through the overnight.
Light snow/flurries will linger across our eastern/northern
counties into Saturday morning, quickly tapering off from
southwest to northeast by midday. A weak surface high to our south
will keep us dry Saturday afternoon into Saturday night. Most of
the PAH forecast area will remain at or below freezing on
Saturday, so not much melting will occur, but southern portions of
the Pennyrile could get above freezing a couple of hours Saturday
afternoon.
Our next system will slide south Sunday into Sunday night. Models
show some light QPF across mainly northern portions of the PAH fa
Sunday afternoon, and our southern half Sunday night. Again, with
temperatures below freezing, light accumulations will again be
possible, especially across our southern half of counties Sunday
night. Models are still iffy with timing and placement, so overall
stayed in the chance category for now.
.LONG TERM...(Monday through Friday)
ISSUED AT 259 PM CST FRI FEB 7 2014
Extended models are in general agreement but there are always issues
in the details.
Main pattern has a weak ridge in the west and a weak trough in the
east. Weak perturbations in the flow will bring small chances of
light snow and or rain/snow.
One disturbance moves through, mainly south of us, on Monday. This
may bring some light snow over the southwest and southern sections.
This trend of pushing this system south continues in the models.
A second impulse moving along the southern states will develop a
stronger surface low along the gulf coast by Wednesday. This may
bring some light precipitation as far north as our eastern sections.
By later on Friday, the ECMWF wants to develop a rather large storm
system over the southern plains. The GFS develops the low much
farther north and would not be a big issue for us. Right now will
keep the forecast dry, but remained concerned as the GFS Ensembles
was to bring precipitation over our area on Friday, but keep the
main low to our north. Confidence in the extended is low.
&&
.AVIATION...
ISSUED AT 523 PM CST FRI FEB 7 2014
VFR cigs will continue this evening...but will lower with time as
an upper level disturbance moves toward the region. Light snow
will likely begin to fall sometime around/after 06Z at KCGI/KPAH
and a few hours later at KEVV/KOWB. With the snow will come MVFR
cigs and possibly MVFR vsbys. The MVFR cigs will likely stick
around for much of the day and possibly scatter out/lift to VFR
late in the day. Winds will be light and variable for the most
part (aob 5-6 kts).
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...WINTER WEATHER ADVISORY until 6 AM CST Saturday FOR MOZ112-114.
IN...NONE.
KY...WINTER WEATHER ADVISORY until 6 AM CST Saturday FOR KYZ001>003-
006-008-009-011>013-016-017-020>022.
&&
$$
MESOSCALE...Smith
UPDATE...Smith
SHORT TERM...RST
LONG TERM...PS
AVIATION...CW
AREA FORECAST DISCUSSION
NWS GRAY ME
216 PM EST THU FEB 6 2014
.SYNOPSIS...
HIGH PRESSURE BUILDS ACROSS THE REGION THROUGH SATURDAY...PRODUCING
A SPELL OF FAIR BUT COLD WEATHER. LOW PRESSURE TRACKS SOUTH OF THE
REGION SUNDAY INTO MONDAY...AND MAY BRING SOME SNOW TO THE REGION.
HIGH PRESSURE RETURNS FOR TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
OVERNIGHT MIN TEMPERATURE FORECAST WILL BE A CHALLENGE OVERNIGHT
AND HIGHLY DEPENDENT ON THE TIMING OF CLOUD COVER OVER THE REGION
LATER THIS EVENING. IT WILL BE WARMER DUR TO THIS INSOLATING
FACTOR WITH TEMPS AT OR ABOVE ZERO IN THE MOUNTAINS TO ABOUT 10
ABOVE AT THE COAST.
LATEST HRRR MODEL RUN CONTINUES TO SHOW PRECIPITATION WITH THE
OFFSHORE STREAMERS DURING THE FIRST HALF OF TONIGHT. WINDS SWITCH
TO THE WEST...MOVING THE SNOW SHOWERS PERPENDICULAR TO THE
SHORE...BUT REMAINING WELL OFF THE COASTLINE. A FEW UPSLOPE SNOW
SHOWERS MAY DEVELOP IN THE MOUNTAINS LATE TONIGHT.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
DOWNSLOPING WINDS WILL ALLOW FOR MORE SUN OVER SOUTHERN PORTIONS
OF ME/NH TOMORROW...WITH LOW CLOUDINESS AND MOISTURE BEING HUNG UP
IN THE WNW FACING HIGHER TERRAIN. THE SUNSHINE OVER SOUTHERN AREAS
SHOULD ALLOW TEMPERATURES TO APPROACH NEAR NORMAL LEVELS FOR
AFTERNOON HIGHS...PUSHING 30 DEGREES ALONG THE COASTLINE WHERE BEST
DIABATIC WARMING TAKES PLACE.
A WEAK FRONT WILL APPROACH FROM THE NORTHWEST FRIDAY NIGHT. THIS
WILL ALLOW MORE MOISTURE TO ENTER THE NORTHERNMOST MOUNTAINS IN
THE FORM OF CLOUDS AND PERHAPS SCATTERED FLURRIES.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
MODELS IN GENERAL AGREEMENT ON BROAD TROUGHING ACROSS THE REGION
WITH A CONTINUATION OF BELOW NORMAL TEMPERATURES. A SERIES OF IMPULSES
WILL RACE EAST ACROSS THE CONUS BEFORE EXITING THE MID ATLANTIC
IN THE LATE SUNDAY - EARLY MONDAY TIMEFRAME. THE SYSTEM WILL BE
PROGRESSIVE AND THERE REMAINS SOME UNCERTAINTY ON ITS EVENTUAL
IMPACT ON THE FORECAST AREA. HOWEVER...THE TREND OVER THE PAST
SEVERAL DAYS HAS BEEN WEAKER AND LITTLE IF ANY PHASING OF ENERGY
WHICH SUPPORTS A RATHER BENIGN SYSTEM. WITH THE EXCEPTION OF THIS
SYSTEM...IT`S SHAPING UP TO BE RATHER QUIET HERE OVER THE NEXT
WEEK. IN THE DAILIES...HIGH PRESSURE WILL BUILD TO THE SOUTH OF
THE AREA SATURDAY. LOW PRESSURE WILL PASS WELL SOUTH AND EAST OF
THE REGION LATE SUNDAY INTO MONDAY. HIGH PRESSURE FOLLOWS THIS
SYSTEM MONDAY NIGHT THROUGH WEDNESDAY.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
SHORT TERM...MAINLY VFR THROUGH TOMORROW NIGHT.
LONG TERM...
SUN PM - MON AM...AREAS OF MVFR IN SNOW ARE POSSIBLE.
&&
.MARINE...
SHORT TERM...SEAS STILL NEAR 5 FEET ALONG THE OUTER COASTAL
WATERS. HOWEVER...THE TREND IS DOWN AND WE WILL BE LOWERING THE
SCAS WITH THIS AFTERNOON FORECAST PACKAGE.
LONG TERM...
SAT...SMALL CRAFT WINDS AND SEAS ARE POSSIBLE.
MON - TUE...SMALL CRAFT WINDS AND SEAS ARE POSSIBLE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
JC/ES
AREA FORECAST DISCUSSION
NWS GRAY ME
1150 AM EST THU FEB 6 2014
.SYNOPSIS...
HIGH PRESSURE BUILDS ACROSS THE REGION TODAY THROUGH
SATURDAY...PRODUCING A SPELL OF FAIR BUT COLD WEATHER. LOW
PRESSURE TRACKS SOUTH OF THE REGION SUNDAY INTO MONDAY...AND MAY
BRING SOME SNOW TO THE REGION. HIGH PRESSURE RETURNS FOR TUESDAY AND
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED THE GRIDS BASED ON CURRENT CONDITIONS. TEMPS WILL
RECOVER FROM A FEW LOCATIONS FALLING TO AS LOW AS 10 BELOW LAST
NIGHT. ALSO...WIND DIRECTION ALONG THE MARINE LAYER WILL BE
SUFFICIENTLY FROM THE NORTHWEST...KEEPING STREAMERS OFFSHORE.
LATEST HRRR RUN SHOWS THESE STREAMER MOVING PARALLEL TO THE
COAST...BUT OFFSHORE BY THIS EVENING AS FLOW BECOMES MORE WEST...SOUTHWESTERLY.
PREV DISC...
HIGH PRESSURE AXIS NUDGES INTO WESTERN NEW ENGLAND TODAY...
WITH A LIGHT NORTHERLY FLOW ACROSS THE FORECAST AREA. SHOULD SEE
CLOUDS DISSIPATING AND GIVING WAY TO A MOSTLY SUNNY SKY... BUT
TEMPERATURES WILL BE A LITTLE BELOW NORMAL WITH HIGHS IN THE 20S.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
A WEAK TROUGH MOVES INTO NORTHERN NEW ENGLAND TONIGHT AND WILL
BRING A FEW MORE CLOUDS AND A LOW CHANCE OF SNOW SHOWERS TO THE
MOUNTAINS. TEMPERATURES FALL OFF INTO THE SINGLE DIGITS AWAY FROM
THE IMMEDIATE COAST... AND BELOW ZERO IN NORTHERN VALLEYS.
MORE QUIET WEATHER EXPECTED FOR FRIDAY AS HIGH PRESSURE AND A FLAT
ZONAL FLOW CONTINUE TO KEEP A COOL AIR MASS IN PLACE WITH NO
SIGNIFICANT DISTURBANCES TO PROVIDE PRECIPITATION.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MID LATITUDES IN THE WESTERN HALF OF THE NORTHERN HEMISPHERE WILL
FEATURE WEAKLY AMPLIFIED FLOW AT 500 MB THROUGH THE FORECAST
PERIOD... WITH SEVERAL WEAK WAVES MOVING THRU THE NORTHERN AND
SOUTHERN STREAMS... BUT NO PHASING FOR ANY COMPLEX SYSTEMS TO
DEVELOP. POLAR VORTEX IS SITUATED IN ITS NORMAL POSITION NEAR
HUDSON BAY AND THE MEAN AREA OF WEAK TROUGHING WILL TAP INTO THIS
SOURCE FOR COLDER AIR AND KEEP TEMPERATURES RUNNING BELOW NORMAL
THRU THE PERIOD... BUT NOT SIGNIFICANTLY SO... WITH HIGHS
GENERALLY RUNNING 5-10 F BELOW NORMAL... AND LOWS SHOWING SLIGHTLY
LESS OF A DEPARTURE FROM NORMAL.
AS FAR AS PRECIPITATION GOES... NEXT CHANCE FOR ANY WILL BE LATE
SUNDAY INTO MONDAY... AS SURFACE LOW TRACKS SOUTH OF THE REGION...
AND COULD BRING SOME LIGHT SNOW TO THE AREA. 00Z EURO IS EVEN
FURTHER SOUTH THAN PREVIOUS RUNS... AND WOULD SEE VERY LIGHT
ACCUMULATIONS IF ANY AT ALL. THE GFS STILL HANGING ONTO THE IDEA
OF AN INVERTED TROUGH... WHICH WOULD BRING SOME ACCUMULATION TO
THE AREA... BUT EXPERIENCE SAYS THAT MODELS TEND TO OVERDO THESE
INVERTED TROUGHS... ESPECIALLY THIS FAR OUT IN THE FORECAST. STILL
ENOUGH THERE TO HANG ONTO THE CHANCE POPS.
BEHIND THIS SYSTEM WILL SEE TEMPERATURES DROP A FEW DEGREES... AS
HIGH PRESSURE BUILDS IN FOR THE MIDDLE OF NEXT WEEK... WITH THE
POSSIBILITY OF ANOTHER COASTAL LOW IN THE VICINITY ON THURSDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SHORT TERM...VFR CONDITIONS EXPECTED WITH LIGHT WINDS. LOWER
CLOUDS MAY HANG ON A LITTLE LONGER TO THE WEST/NORTH OF THE
MOUNTAINS THIS MORNING BUT EVEN THIS SHOULD GIVE WAY TO VFR.
LONG TERM...MAINLY VFR. LOW PRESSURE PASSING TO OUR SOUTH COULD
PRODUCE SOME FLIGHT RESTRICTIONS IN SNOW LATE SUNDAY INTO
MONDAY... WITH THE BETTER CHANCE AT COASTAL TERMINALS.
&&
.MARINE...
SHORT TERM...SEAS CONTINUE TO BE HIGHER THAN MODEL FORECASTS
ACROSS THE GULF OF MAINE THIS MORNING PRIMARILY DUE TO WIND WAVES
ASSOCIATED WITH THE HIGHER WINDS. THESE WINDS HAVE BEGUN TO
SUBSIDE... AND IT WILL TAKE A WHILE FOR THE WAVE HEIGHTS TO FALL
BELOW 5 FEET. THE SMALL CRAFT ADVISORY CONTINUES UNTIL 4 PM THOUGH
IT MAY BE ABLE TO BE DROPPED EARLIER IF OBSERVATIONS SUPPORT THIS.
LONG TERM...IN GENERAL WINDS SEAS WILL STAY BELOW SCA LEVELS
FRIDAY NIGHT THRU MONDAY... ALTHOUGH CANNOT RULE OUT BORDERLINE
SCA CONDITIONS AS LOW PRESSURE PASSES TO THE SOUTH LATE SUNDAY
INTO MONDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EST THIS
AFTERNOON FOR ANZ150-152-154.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
635 PM EST FRI FEB 7 2014
.SYNOPSIS...
A SERIES OF FAST MOVING DISTURBANCES WILL RESULT IN SEVERAL
PERIODS LIGHT SNOW OVER THE WEEKEND...WITH CONTINUED BELOW NORMAL
TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
DECREASED CLOUD COVER THIS EVENING AS THE IR SATELLITE SHOWS CLEAR
SKIES UNDER HIGH PRESSURE. RAP MODEL IS MUCH SLOWER BRINGING
MOISTURE BACK INTO THE AREA SATURDAY MORNING...BUT THIS SHOULD
ONLY DELAY THE ONSET OF CLOUDS. HAVE PUSHED BACK THE CLOUD
DEVELOPMENT WITH THIS IN MIND. REST OF FORECAST REMAINS UNALTERED.
...PREVIOUS DISCUSSION BELOW...
CLOUD COVERAGE WILL INCREASE FROM THE SOUTH OVER THE COURSE OF THE
NIGHT AS A MINOR SHORTWAVE APPROACHES FROM THE WEST. TEMPERATURES
WILL DECREASE QUICKLY OVERNIGHT UNDER MORE IDEAL RADIATIONAL
COOLING CONDITIONS WITH LIGHT WINDS AND CLOUD COVERAGE NOT
EXPECTED TO SIGNIFICANTLY INCREASE UNTIL AFTER MIDNIGHT. APPARENT
TEMPERATURES WILL DROP BELOW ZERO ACROSS NORTHERN ZONES...BUT NOT
REACH VALUES WARRANTING A WIND CHILL ADVISORY.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
MINOR SOUTHERN STREAM SHORTWAVE WILL BRUSH BY TO THE SOUTH AND
RESULT IN A SLIGHT CHANCE OF SNOW MAINLY ACROSS THE SOUTHEAST
RIDGES ON SATURDAY MORNING. THIS WILL BE FOLLOWED BY A SECOND AND
THIRD SHORTWAVE PASSING OVER THE FORECAST AREA SATURDAY NIGHT AND
SUNDAY NIGHT. MOST LOCATIONS WILL LIKELY SEE SEVERAL PERIODS OF
OF LIGHT SNOW BUT WITH VERY LITTLE MOISTURE TO WORK WITH...SNOW
AMOUNTS WILL BE RELATIVELY LIGHT WITH EACH FEATURE.
OVERALL...LOCATIONS ALONG THE I80 CORRIDOR AND SOUTHEAST RIDGES
WILL SEE THE HIGHEST THREE DAY TOTALS...AROUND 3 INCHES ON
AVERAGE. ELSEWHERE...TOTALS WILL RANGE FROM ONE TO TWO INCHES.
&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LONG TERM WAS ADJUSTED TOWARDS THE LATEST GFS...ECMWF...AND
ENSEMBLE RUNS AS THERE IS SOME BETTER AGREEMENT ON THE DEVELOPMENT
OF THE SYSTEM THAT COULD CLIP OUR REGION MIDWEEK FOLLOWED BY
ANOTHER ARCTIC FRONT TOWARDS THE END OF THE PERIOD. CONSIDERING
THERE REMAINS TIMING AND PLACEMENT DIFFERENCES...MAINTAINED THE
CHANCE POPS THAT WERE IN THE FORECAST BUT CHANGED THE TIMING OF
THE SYSTEM SINCE MODEL CONSENSUS SEEMS TO KEEP PRECIP OUT OF THE
VICINITY OF OUR CWA UNTIL WEDNESDAY NIGHT. WITH THE STORM SEVERAL
DAYS OUT...THE MODELS COULD STILL FLUCTUATE SO CONFIDENCE REMAINS
LOW. HOWEVER...PRECIPITATION LOOKS TO REMAIN SNOW WITH THE COASTAL
LOW BUT COULD CHANGE TO RAIN IN ADVANCE OF THE FRONT.
TEMPERATURES WERE A BLEND OF GUIDANCE AS WELL...WITH A BIT MORE
EMPHASIS ON THE COLDER ECMWF. THIS KEPT HIGHS AND LOWS JUST BELOW
SEASONAL AVERAGES.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS THROUGH SATURDAY MORNING. WINDS W-SW 5 TO 10 KTS.
AREA OF MVFR CIGS WILL MOVE IN FROM THE SOUTH SATURDAY AFTERNOON.
A FLURRY POSSIBLE AT MGW AND ZZV LATE AFTERNOON.
.OUTLOOK..../SATURDAY THROUGH TUESDAY/...
A SERIES OF DISTURBANCES WL SPAWN PERIODIC SNOW SHWRS AND RESULTING
RESTRICTIONS THROUGH EARLY NXT WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
940 AM EST THU FEB 6 2014
.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE GREAT LAKES REGION TODAY
FOLLOWED BY HIGH PRESSURE LATE TONIGHT AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOR THE MORNING UPDATE...MADE SOME ADJUSTMENTS TO
TEMPS...SKY...AND POPS BASED ON SATELLITE...RADAR...AND SURFACE
OBSERVATIONS. SOME SCATTERED FLURRIES CONTINUE TO LINGER IN
NORTHWEST FLOW...ESPECIALLY IN THE RIDGES WITH THE HELP OF
UPSLOPE...BUT THIS SHOULD BEGIN TO TAPER OFF SHORTLY AS INVERSION
HEIGHTS FALL.
ANOTHER WEAK TROUGH WILL CROSS THE GREAT LAKES TODAY BUT WITH
LITTLE MOISTURE...NO PRECIPITATION IS EXPECTED. TEMPERATURES WILL
REMAIN BELOW SEASONAL AVERAGES WITH HIGHS IN THE TWENTIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
THE WK TROF MAY BRING A FEW FLURRIES N AND E OF PIT THIS
EVE...OTRW HIGH PRES WL GRDLY BLD IN THRU FRI. MOISTURE BEGINS TO
INCR SAT ON THE NRN PERIPHERY OF A LOW OFF THE SE COAST...AND IN
ADVANCE OF ANOTHER SHRTWV ACRS THE MD WEST. MDL PROGS DO NOT PHASE
THESE TWO SYSTEMS...THEREFORE ONLY CHC POPS FCST FOR SAT FOR SNW
AS UPR SPPRT IS LACKING. AS THE MD WEST SHRTWV CROSSES THE RGN SAT
NGT...WENT WITH LIKELY POPS FOR LGT SNW WITH SUFFICENT UPR SPPRT
AND MOISTURE. ANOTHER FAST MOVG SHRTWV CROSSES THE GT LKS/UPR OH
VLY SUN...WITH CHC POPS MAINTAINED DUE TO QN IN TIMING AND AVAIL
UPR SPPRT. TEMPS SHOULD REMAIN BLO SEASONAL AVGS THRU THE PD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
LONG TERM FORECAST WAS CONSTRUCTED USING WPC GUIDANCE WITH GENLY
DRY AND SEASONABLY COLD CONDITIONS UNTIL FORMATION OF MID ATLANTIC
LOW PRES BY MID WEEK...WHICH COULD SPREAD MORE SNOW ACRS THE UPR
OH REGION. CHC POPS WERE INCLUDED FOR THAT SCENARIO...BUT
CONFIDENCE IS MINIMAL AT MOMENT GIVEN THE TIMING AND DIFFERENCES
IN MDL TRENDS.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
MVFR STRATOCU WL CONT TO FLOW ACRS UPR OHIO TERMINALS THIS MRNG AS
COLD ADVCTN ON WEAKENING NW BNDRY LYR FLOW PERSISTS. AS THAT FLOW
DRIES AND BACKS...EXPECT IMPROVEMENT TO VFR.
WEAK DISTURBANCE IS PROGGED TO INCRS MID LVL CLDS THIS AFTN ALNG
WITH SOME FLAT STRATOCU GIVEN THE LOW CONVECTIVE THRESHOLDS. WL
FOLLOW THE LATEST HRRR TRENDS AND REINTRODUCE MVFR CONDITIONS FOR
THE AFTN.
.OUTLOOK..../THURSDAY THROUGH MONDAY/...
A SERIES OF DISTURBANCES WL INCRS PCPN AND RESTRICTION CHCS THIS
WEEKEND.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
350 PM CST THU FEB 6 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM CST THU FEB 6 2014
ANOTHER NIGHT...ANOTHER WIND CHILL ADVISORY...THAT IS PRETTY MUCH
ALL THAT CAN BE SAID ABOUT THE SHORT TERM PERIOD. THE ARCTIC
HIGH...WHICH HAS BEEN ON A SLOW MARCH SOUTHEAST THE LAST COUPLE OF
DAYS IS NOW CENTERED DOWN IN THE KC METRO AREA...THOUGH THE CENTRAL
PRESSURE IS NOW UP TO ABOUT 1035 MB...WHICH REPRESENTS ABOUT A 20 MB
DROP IN PRESSURE OVER THE LAST 24 HOURS. DESPITE THE FALLING
PRESSURE...ITS AIRMASS STILL PACKS A GOOD PUNCH...WITH HIGHS TODAY
FIGHTING TO GET ABOVE ZERO HERE AND SINGLE DIGITS HIGHS THIS
AFTERNOON EXISTING ALL THE WAY DOWN TO THE OK/TX PANHANDLES.
IF YOU ARE LOOKING FOR A POSITIVE SIGN OF WARMER WEATHER TO
COME...WE GOT IT TODAY WHEN THE FULL SUNSHINE WAS POWERFUL ENOUGH TO
GENERATE JUST ENOUGH MIXING TO DEVELOP A THIN CU FIELD THIS
AFTERNOON. UNFORTUNATELY...THIS CLOUD COVER WILL QUICKLY GO AWAY
TONIGHT AS THE SUN SETS...LEAVING US WITH ANOTHER STARRY AND COLD
NIGHT. WEST WINDS TONIGHT WILL HAVE SLIGHT WARM ADVECTIVE
PROPERTIES...BUT WILL ONLY BE ENOUGH TO JUST MAKE TONIGHT 2 OR 3
DEGREES WARMER THAN LAST NIGHT. THOSE FAIRLY PERSISTENT 5-10 MPH
WINDS COMBINED WITH LOWS BACK DOWN IN THE NEIGHBORHOOD OF -10 WILL
AGAIN SEND WIND CHILL TEMPERATURES TUMBLING DOWN TO -25 OR
LOWER...HENCE THE REAPPEARANCE OF A WIND CHILL ADVISORY BETWEEN
MIDNIGHT AND 9 AM FRIDAY.
FOR FRIDAY...WINDS WILL DIMINISH AS WE GET INTO A BAGGY RIDGE AXIS
AHEAD OF THE SATURDAY SNOW MAKER. WEAK WAA FROM THE NIGHT BEFORE
WILL ALLOW TEMPS TO WARM CLOSE TO 10 DEGREES ABOVE WHAT WE ARE
SEEING TODAY...BUT THOSE LIGHT WINDS WILL LIMIT MIXING...WHICH WILL
MAKE IT TOUGH TO GET MUCH HIGHER THAN THE LOWER TEENS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM CST THU FEB 6 2014
LITTLE CHANGE OVERALL TO THE LONG TERM FORECAST. SNOW EVENT ACROSS
SOUTHERN MN STILL IN THE FORECAST. NEW RUNS OF THE GFS AND NAM THIS
MORNING WERE IN VERY GOOD AGREEMENT CONCERNING THE QPF EXTENT AND
AMOUNTS...AND WITH THE TRACK OF A WEAK SURFACE LOW. THE ECMWF
REMAINS THE OUTLIER IN HANDLING THE UPPER LEVEL SHORTWAVE...AND
STILL DOES NOT DEVELOP A SURFACE LOW AS THE OTHER MODELS DO.
STILL...IT DOES BRING SOME LIGHT SNOW INTO SOUTHERN MINNESOTA AS
WELL. THE 18Z NAM ACTUALLY CAME IN WITH EVEN LESS QPF...BUT WILL
CONTINUE WITH A SLIGHTLY HIGHER AMOUNT IN THE FORECAST GIVEN THE
STRONG FORCING ASSOCIATED WITH THIS WAVE.CONTINUED CATEGORICAL POPS
ACROSS THE SOUTH AS THE I-90 CORRIDOR LOOKS TO BE BEST POSITIONED
FOR THE HIGHEST SNOW AMOUNTS IN THE MPX CWA...BETWEEN 2-3". DESPITE
STRONG FORCING WITH THIS SHORTWAVE...SLIGHTLY LOWERED SNOWFALL
AMOUNTS AS NEW MODEL RUNS CAME IN WITH SLIGHTLY LESS QPF...AND
COLLABORATED SNOW RATIOS INDICATED THOSE NEEDED TO BE LOWERED
SLIGHTLY AS WELL. MODELS TENDED TO SLIGHTLY SLOW THE SYSTEM DOWN AS
WELL...SO WENT AHEAD AND ADJUSTED THE TIMING OF INCREASING POPS
FRIDAY NIGHT TO SLOW IT DOWN JUST A FEW HOURS. SNOW RATIOS WILL BE
CRITICAL IN THIS EVENT AS THE MOISTURE AVAILABLE IS RATHER
LIMITED...BUT THE DENDRITIC GROWTH ZONE VERY DEEP...SO GENERALLY
LIGHT QPF SNOW THAT WILL PILE UP EASILY BEING IN DENDRITIC FORM.
ONCE THE SNOW EVENT ON SATURDAY DEPARTS...YET ANOTHER ARCTIC HIGH
FILLS IN FROM ALBERTA/SASKATCHEWAN WITH TEMPERATURES LOOKING QUITE
COLD MONDAY MORNING WHEN TEENS AND TWENTIES BELOW ZERO RETURN TO THE
REGION. AN ALBERTA CLIPPER LOOKS TO SPREAD LIGHT SNOW THROUGH THE
UPPER MIDWEST TUESDAY NIGHT/WEDNESDAY...WHICH WILL BE FOLLOWED BY A
WARM UP TO NEAR NORMAL TEMPERATURES LATER IN THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1202 PM CST THU FEB 6 2014
ONLY CONCERN FOR TAFS IS BATCH OF CLOUD COVER THAT MOVED OUT OF
NODAK AND INTO NW MN THIS MORNING. THEY HAVE BEEN STRUGGLING TO
PUSH SOUTHEAST THIS MORNING...BUT THE RAP AND NAM WANT TO SHOW
THIS CLOUD BANK COMING DOWN ESSENTIALLY I-94 IN ONE FORM OR
ANOTHER. CONFIDENCE NOT OVERLY HIGH ON HOW MUCH THESE CLOUDS WILL
HOLD TOGETHER...SO MAINLY WENT WITH A PERIOD OF SCT025 AT
TERMINALS TO REFLECT MOST LIKELY PERIOD WHEN THIS CLOUD SHIELD OR
ITS REMNANTS WOULD MOVE BY. ONLY AIRPORT TO GET PREDOMINATE MVFR
CIG TREATMENT WAS AXN...BUT WITH MVFR CIGS ONLY A COUNTY AWAY THEY
SHOULD HAVE NO PROBLEM FILTERING INTO THE AXN AREA THIS AFTERNOON.
EARLIER THIS MORNING THESE CLOUDS WERE PRODUCING -SN ACROSS
NODAK...BUT THAT HAS SINCE CEASED...SO INCLUDED NO SNOW MENTION
AT AXN WITH THESE CLOUDS. CONFIDENCE IS HIGH WITH THE REST OF TAF
PERIOD.
KMSP...WILL HAVE TO WATCH THE CLOUD BANK TO THE NW...BUT THERE IS
A POSSIBILITY THAT THERE COULD BE SOME BKN MVFR CIGS FOR A LITTLE
BIT 00Z AND 04Z. OTHERWISE...NO CONCERNS WITH THE REST OF THE TAF.
/OUTLOOK FOR KMSP/
SAT...MVFR/-SN LIKELY WITH IFR POSSIBLE. WINDS WNW AT 5KTS.
SUN...VFR. WINDS NW AT 10KTS.
MON...VFR. WINDS W AT 5KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST FRIDAY FOR
MNZ041>045-047>070-073>078-082>085-091>093.
WI...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST FRIDAY FOR
WIZ014>016-023>028.
&&
$$
SHORT TERM...MPG
LONG TERM...SPD
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1202 PM CST THU FEB 6 2014
.UPDATE...
ISSUED AT 1202 PM CST THU FEB 6 2014
WITH THE EXPIRATION OF THE WIND CHILL ADVISORY THIS MORNING...WENT
AHEAD AND POSTED YET ANOTHER WIND CHILL ADVY FOR TONIGHT INTO
FRIDAY MORNING. LOWS TONIGHT WILL BE NO MORE THAN 3 DEGREES WARMER
THAT WHAT WAS SEEN LAST NIGHT...AND WITH WINDS EXPECTED TO REMAIN
BETWEEN 5 AND 12 MPH...WE WILL AGAIN SEE WIND CHILL VALUES DROP TO
-25 OR COLDER ACROSS THE ENTIRE MPX CWA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CST THU FEB 6 2014
EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH 500MB HEIGHTS AND
WINDS SHOWS A BROAD LONGWAVE TROUGH EXPANDING THE ENTIRE BREADTH OF
NORTH AMERICA. THERE WERE A FEW SHORTWAVES LOCATED ON THE POLEWARD
SIDE OF THE JET...BUT THEY ARE NOT EXPECTED TO PRODUCE ANY
PRECIPITATION OVER THE UPPER MIDWEST. AT THE SURFACE A RIDGE OF HIGH
PRESSURE WAS DRAPED ALONG THE UPPER MISSOURI RIVER VALLEY...WHILE A
SURFACE LOW WAS LOCATED ACROSS HUDSON BAY. THIS LED TO PERSISTENT
WEST NORTHWEST WIND OF 5 TO 15 MPH...AND WHEN COMBINED WITH
TEMPERATURES OF -10 TO -15F PRODUCED WIND CHILLS NEAR -30F.
OVER THE NEXT 24 HOURS HIGH PRESSURE WILL CONTINUE TO BUILD DOWN THE
MISSOURI RIVER VALLEY. THE WINDS ACROSS MN/WI WILL GRADUALLY TAKE ON
A SOUTHERLY COMPONENT BY FRIDAY MORNING...BUT RADIATIONAL COOLING
WILL OVERTAKE THE WEAK WARM AIR ADVECTION AND THURSDAY NIGHT
TEMPERATURES WILL STILL FALL BELOW ZERO ONCE AGAIN. DESPITE THE
LIGHT SNOW THAT FELL ON WEDNESDAY...WOULD LIKE TO DOUBLE DOWN ON A
DRY FORECAST FOR REDEMPTION AS CONFIDENCE REMAINS HIGH THAT NO
PRECIPITATION WILL FALL NOW THROUGH FRIDAY MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CST THU FEB 6 2014
SURPRISE SURPRISE THE BIGGEST STORY FOR THE LONG TERM IS THE
COLD...BUT THERE IS A MODEST TWINKLE OF LIGHT AT THE END OF THE
TUNNEL. MORE ON THAT IN A BIT. THE BIGGEST CHANGE OF THIS FORECAST
PACKAGE IS TO CONTINUE BOOSTING CHANCES OF SNOW LATE FRIDAY NIGHT
AND SATURDAY AS MODELS SLOWLY HONE IN ON A COMMON SOLUTION. THE
SURFACE RIDGE WILL SLIDE SOUTHEAST INTO THE OHIO VALLEY FRIDAY
AFTERNOON WITH ZONAL FLOW AND A POWERFUL UPPER JET EXTENDING INTO
THE CENTRAL ROCKIES FROM THE CENTRAL NORTHERN PACIFIC. A SHORT
WAVE ON THE LEADING EDGE OF THIS JET WILL RACE EASTWARD ACROSS THE
NORTHERN ROCKIES AND INTO THE NORTHERN/CENTRAL PLAINS LATE FRIDAY
NIGHT. THE GFS REMAINS THE MOST CONSISTENT SOLUTION AND JUST ABOUT
EVERY ENSEMBLE MEMBER SUPPORTS THE IDEA OF A STRONGER WAVE WITH
MORE ROBUST SNOWFALL. THE NAM AND GEM ARE GENERALLY ALONG THE SAME
LINES AS THE GFS...WITH THE ECMWF THE LEAST CONSISTENT AND
WEAKEST...TO THE POINT WHERE ALMOST NO SNOW FALLS ACROSS THE AREA.
THE ODD THING ABOUT THE ECMWF AS WPC POINTS OUT...MASS FIELDS ARE
SIMILAR TO THE GFS BUT THE SURFACE REFLECTION IS NOT REPRESENTATIVE
AT ALL. THE MID LEVEL ENERGY LOOKS PRETTY IMPRESSIVE WITH A NICE
DEEPENING OF THE 500 AND 700 MB TROUGHS AS IT PASSES THROUGH. THE
700 MB LOW PASSES RIGHT OVERHEAD. OMEGA DOESN/T LOOK NEARLY AS
ROBUST AS THE LAST SYSTEM...BUT THE DENDRITIC GROWTH ZONE IS
RATHER DEEP...EXTENDING FROM THE SURFACE TO ABOUT 650 MB.
ISENTROPIC LIFT IS PRETTY DECENT TOO...BUT MIXING RATIOS ARE
MEAGER AND PW VALUES ONLY REACH ABOUT 1/4 INCH. THERE WILL BE A
WELL DEVELOPED SNOW SHIELD WITH THE DYNAMICS PRESENT BUT THE
INTENSITY IS A BIT IN QUESTION GIVEN THE NEGATIVE FACTORS. LOOKING
AT THE AMOUNT OF MOISTURE AVAILABLE...THINK THE MAX ACCUMULATION
POTENTIAL IS ABOUT 3 INCHES.
THE SNOW WILL TAPER OFF SATURDAY AFTERNOON WITH ANOTHER HIGH
BUILDING INTO THE DAKOTAS SATURDAY NIGHT. EARLY NEXT WEEK LOOKS
REAL COLD WITH HIGHS IN THE SINGLE DIGITS AND LOWS IN THE TEENS
AND POSSIBLY 20S BELOW ZERO.
THE STORM TRACK SHIFTS TOWARD THE CANADIAN BORDER DURING THE
MIDDLE OF NEXT WEEK WITH MILDER AIR /BUT STILL BELOW NORMAL/
PUSHING BACK IN FROM THE SOUTHWEST. EVENTUALLY THE RIDGE BUILDS
BACK UP THE WEST COAST AND A COLDER PATTERN WILL RETURN SOMETIME
LATE IN THE WEEK.
SOMETHING INTERESTING AND A BIT DEPRESSING OF NOTE...THE WARMEST
MEMBER OF THE CFS ONLY REACHES 40 A FEW TIMES DURING THE NEXT 45
DAYS AT MSP. WHAT/S WORSE IS THE COLDEST MEMBER DROPS BELOW ZERO
ABOUT FIVE TIMES AS OFTEN DURING THE SAME PERIOD. WHAT/S WORSE
STILL IS CPC CHOOSING TO IGNORE THE CFS FOR BEING TOO WARM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1202 PM CST THU FEB 6 2014
ONLY CONCERN FOR TAFS IS BATCH OF CLOUD COVER THAT MOVED OUT OF
NODAK AND INTO NW MN THIS MORNING. THEY HAVE BEEN STRUGGLING TO
PUSH SOUTHEAST THIS MORNING...BUT THE RAP AND NAM WANT TO SHOW
THIS CLOUD BANK COMING DOWN ESSENTIALLY I-94 IN ONE FORM OR
ANOTHER. CONFIDENCE NOT OVERLY HIGH ON HOW MUCH THESE CLOUDS WILL
HOLD TOGETHER...SO MAINLY WENT WITH A PERIOD OF SCT025 AT
TERMINALS TO REFLECT MOST LIKELY PERIOD WHEN THIS CLOUD SHIELD OR
ITS REMNANTS WOULD MOVE BY. ONLY AIRPORT TO GET PREDOMINATE MVFR
CIG TREATMENT WAS AXN...BUT WITH MVFR CIGS ONLY A COUNTY AWAY THEY
SHOULD HAVE NO PROBLEM FILTERING INTO THE AXN AREA THIS AFTERNOON.
EARLIER THIS MORNING THESE CLOUDS WERE PRODUCING -SN ACROSS
NODAK...BUT THAT HAS SINCE CEASED...SO INCLUDED NO SNOW MENTION
AT AXN WITH THESE CLOUDS. CONFIDENCE IS HIGH WITH THE REST OF TAF
PERIOD.
KMSP...WILL HAVE TO WATCH THE CLOUD BANK TO THE NW...BUT THERE IS
A POSSIBILITY THAT THERE COULD BE SOME BKN MVFR CIGS FOR A LITTLE
BIT 00Z AND 04Z. OTHERWISE...NO CONCERNS WITH THE REST OF THE TAF.
/OUTLOOK FOR KMSP/
SAT...MVFR/-SN LIKELY WITH IFR POSSIBLE. WINDS WNW AT 5KTS.
SUN...VFR. WINDS NW AT 10KTS.
MON...VFR. WINDS W AT 5KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST FRIDAY FOR
MNZ041>045-047>070-073>078-082>085-091>093.
WI...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST FRIDAY FOR
WIZ014>016-023>028.
&&
$$
UPDATE...MPG
SHORT TERM...JRB
LONG TERM...BORGHOFF
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1104 AM CST THU FEB 6 2014
.DISCUSSION...UPPER DISTURBANCE IS NOW SWINGING ACROSS THE LOWER MS
RIVER VALLEY...WITH MOSTLY LIGHT PRECIPITATION ONGOING ACROSS
EASTERN TEXAS AND LOUISIANA. THUS FAR...A FEW REPORTS OF FLURRIES
AND/OR LIGHT SLEET HAVE BEEN RECEIVED FROM OUR NE LOUISIANA PARISHES
AND INTO THE NATCHEZ AND BROOKHAVEN AREAS. HOWEVER...MUCH OF THE
PRECIP BEING DETECTED BY RADAR IS NOT REACHING THE GROUND. FOR
INSTANCE...CALLS TO RICHLAND AND FRANKLIN PARISHES UNDER SOME OF THE
20-30 DBZ RETURNS YIELDED NO REPORTS. FARTHER WEST...MAINLY TO THE
WEST OF ALEXANDRIA...WHERE THERE HAS BEEN MORE OPPORTUNITY FOR THE
ATMOSPHERE TO MOISTEN DOWN TO THE SURFACE...LIGHT TO OCCASIONALLY
MODERATE...SNOW IS REACHING THE GROUND MORE EFFECTIVELY. GREATEST
ACCUMULATIONS WE HAVE BEEN MADE AWARE OF IN THAT AREA WERE A DUSTING
IN GRANT PARISH.
MANY HI-RES MODELS HAVE SHOWN A SCARCITY OF QPF ACROSS OUR SOUTHERN
ZONES...HOWEVER THEY HAVE ALSO NOT HAD THE BEST HANDLE ON THE PRECIP
THAT WAS ONGOING ACROSS EAST TEXAS AND PARTS OF WESTERN LOUISIANA
THIS MORNING. THE LATEST RUNS OF THE RAP HAVE BEGUN TO BETTER HANDLE
THE ONGOING PRECIPITATION AND NOW SHOW A CORRIDOR OF QPF (UP TO .1
INCH) SOUTH OF I-20 DOWN TO THE MS/LA BORDER. THE 12Z GFS HAS ALSO
COME IN A BIT WETTER FOR THE SAME AREA.
BASED ON THESE TRENDS AND RECENT REPORTS OF SOME ACCUMULATIONS
BEGINNING ON BRIDGES NW OF ALEXANDRIA...WE HAVE OPTED TO POST A
WINTER WEATHER ADVISORY FOR PORTIONS AREAS SOUTH OF I-20 EASTWARD TO
AROUND HIGHWAY 49. OUR EXPECTATIONS OF LIGHT SNOW AND SLEET
ACCUMULATION BETWEEN A DUSTING TO LESS THAN AN INCH HAVE NOT
CHANGED...BUT WITH TEMPERATURES LINGERING NEAR OR BELOW FREEZING WE
ARE MORE CONCERNED ABOUT SLICK SPOTS DEVELOPING ON ELEVATED ROAD
SURFACES. IT IS POSSIBLE THE ADVISORY WOULD NEED TO LATER BE
EXPANDED FARTHER EASTWARD...BUT FOR NOW WE EXPECT TEMPERATURES TO BE
LESS FAVORABLE FOR ACCUMULATIONS AS PRECIP REACHES SOUTHEAST MS.
FORECAST UPDATES WILL BE SENT WITHIN THE NEXT HOUR.
NOTE: A SPECIAL 18Z UPPER AIR FLIGHT WILL BE CONDUCTED TODAY TO
ASSIST WITH TODAY`S WINTER WEATHER FORECAST. /DL/
&&
.PREV DISCUSSION... /ISSUED AT 432 AM CST THU FEB 6 2014/
SHORT TERM...TODAY THROUGH FRIDAY NIGHT...SOMEWHAT MORE POTENT
SHORTWAVE THAN MODELS HAVE BEEN HANDLING...CURRENTLY MOVING OUT OF
NORTHERN MEXICO...WILL BE THE MAIN FOCUS FOR TODAY. WV IMAGERY
SHOWING INCREASINGLY BACKED FLOW YIELDING INCREASED ISENTROPIC LIFT
AND COOLING CLOUD TOPS AT PRESENT OVER THE LOWER MS VALLEY. GFS BUFR
SOUNDINGS SHOWING SOME POTENTIAL FOR SNOW SHOWERS ACROSS MAINLY
CENTRAL AND SOUTH LATE MORNING INTO EARLY AFTERNOON. MODEL CROSS
SECTIONS CONFIRM THE CONVECTIVE THREAT WITH ELEVATED CAPE VALUES
AROUND 200 J/KG OVER SOUTH MS ALONG WITH 20 UB/S OF OMEGA. ALL THIS
OCCURRING IN THE -5 TO -15C PREFERRED DENDRITIC GROWTH ZONE.
DESPITE THE STRONG VERTICAL MOTION FOR GOOD SNOWFALL...THERE ARE
SOME ROADBLOCKS THAT WILL HAVE TO BE OVERCOME FOR DECENT
ACCUMULATIONS TO OCCUR. FIRST IS THE SPEED OF THE SYSTEM. THERE
LOOKS TO BE ONLY ABOUT A FOUR TO SIX HOUR PERIOD OF TIME WHEN THESE
CONDITIONS WILL EXIST OVER THE AREA. NEXT...BELOW THE ASCENT IS
A VERY DRY LAYER. BELIEVE IT WILL TAKE A COUPLE HOURS OF
PRECIPITATION THROUGH THE DRY LAYER TO SATURATE ENOUGH FOR
ACCUMULATING PRECIPITATION TO MAKE IT TO THE GROUND. BY THIS
TIME...THE MAJORITY OF VERTICAL MOTION WILL HAVE PUSHED EAST. THE
OTHER OBSTACLE WILL BE LOW LEVEL TEMPS. MODEL SOUNDINGS IN THE SOUTH
SHOW A GOOD POSSIBILITY OF SNOW MIXING WITH RAIN AS THERE ARE
SEVERAL BUMPS IN THE TEMPERATURE PROFILE ABOVE FREEZING BELOW THE
ASCENT LAYER. IN ADDITION...SURFACE TEMPS LOOK TO BE ABOVE FREEZING
AT MOST PLACE AT THE ONSET OF SNOW. ALTHOUGH ACCUMULATIONS CAN OCCUR
WHEN TEMPS ARE ABOVE FREEZING...ESPECIALLY WITH HEAVY SNOW...BELIEVE
LISTED LIMITATIONS ABOVE WILL PREVENT A HEAVY SNOW AND ONLY YIELD
LIGHT ACCUMULATIONS (< 1 INCH)...MAINLY ON GRASSY SURFACES...EXPOSED
OBJECTS AND BRIDGES/OVERPASSES. LATEST NAM AND SREF HAVE TRENDED
LIGHTER IN QPF AMOUNTS AS WELL. AFTER COORDINATING WITH SURROUNDING
SITES...WILL HOLD OFF ON ISSUING AN ADVISORY AT THE MOMENT GIVEN
RAISED QUESTION MARKS IN POSSIBLE ACCUMULATIONS.
THE FAST PACED PROGRESSIVE FLOW WILL QUICKLY EJECT TODAYS SYSTEM
EAST TONIGHT WITH NEXT SHORTWAVE POISED TO DROP IN FRIDAY NIGHT.
ONCE AGAIN SHORT TERM ISENTROPIC ASCENT WILL PRODUCE WIDESPREAD
LIGHT RAINS WITH SOMEWHAT WARMER COLUMN THIS TIME. SOME RISK OF
LIGHT FREEZING RAIN WILL EXIST OVER THE FAR NORTHERN SECTIONS NEAR
THE END OF THE EVENT AS SURFACE TEMPS DROP INTO THE LOWER 30S BY
EARLY SATURDAY MORNING./26/
LONG TERM...(SATURDAY THROUGH THURSDAY)...THE PRIMARY CONCERNS WILL
BE A RATHER ACTIVE PATTERN FOR THE PERIOD...SOME OF WHICH COULD BRING
SOME LIGHT WINTER PRECIPITATION IN THE NORTH FOR MONDAY NIGHT INTO
EARLY TUESDAY. THERE IS ANOTHER CHANCE OF RAIN FOR TUESDAY NIGHT INTO
WEDNESDAY THAT WILL BEAR WATCHING IN FUTURE MODEL RUNS. THIS FOLLOWED
BY TEMPS AND POPS IN THE PROGRESSIVE UPPER PATTERN.
FOR SATURDAY MORNING THE PATCHY LIGHT RAIN WILL DEPART FROM THE
REGION BEFORE DRY WEATHER SETS IN FOR SATURDAY AFTERNOON THROUGH
SUNDAY NIGHT WITH A PROGRESSIVE FLOW PATTERN ALOFT. OUR NEXT CHANCE
OF RAIN WILL COME MONDAY AFTERNOON AS WE GET SOME ISENTROPIC LIFT TO
BRING IN SOME SPOTTY LIGHT RAIN. A SOUTHERN STREAM SHORT WAVE WILL
APPROACH THE REGION DURING THE DAY MONDAY AND BRING BRING SOME
BETTER LIFT ACROSS THE REGION ON MONDAY NIGHT INTO TUESDAY. MODEL
SOUNDINGS SHOW THAT THERE WILL BE ENOUGH LOW LEVEL COLD AIR
ADVECTION TO BRING A MIXED BAG OF LIGHT WINTER PRECIPITATION ACROSS
THE NORTH. THIS WAS AGREED UPON BY THE EURO AND GFS MODELS...WHICH
JUST STARTED ON THIS MODEL RUN. BY LATE MONDAY NIGHT EXPECT ENOUGH
COLD AIR IN THE LOWER LEVELS TO MAKE IT ALL LIGHT SNOW IN THE NORTH
WITH LIGHT RAIN ELSEWHERE. AS WE GO INTO TUESDAY MORNING MODEL
SOUNDINGS ACROSS THE NORTH SHOWS THAT THE WARM NOSE WILL DIP FARTHER
TOWARD THE SURFACE...WHICH MAY BRING A LIGHT MIXTURE OF LIGHT
RAIN...LIGHT SLEET AND LIGHT FREEZING RAIN. TEMPS WILL RISE DURING
THE MORNING TO MAKE IT ALL RAIN BY THE AFTERNOON. AS WE GO INTO
TUESDAY NIGHT AND WEDNESDAY THE SOUTHERN STREAM SHORT WAVE WILL
CROSS INTO THE REGION. THE GFS AND EURO HAS SOME DIFFERENT OPINIONS
OF A DEEPENING WAVE ALONG A FRONTAL BOUNDARY. THE GFS HAS IT FARTHER
SOUTH OF THE REGION...THUS BRINGING COLDER AIR INTO THE
REGION...WHICH MAY BRING WINTER PRECIPITATION...WHILE THE EURO HAD
THE DEEPENING LOW CROSSING THE FORECAST AREA..THUS KEEPING IT A COLD
RAIN. SO OPTED TO GO TOWARD THE MILDER EURO SOLUTION. THUS WILL KEEP
IT A COLD RAIN FOR TUESDAY NIGHT INTO WEDNESDAY. THE RAINS WILL MOVE
OUT OF THE AREA BY WEDNESDAY NIGHT.
AS FAR AS TEMPS ARE CONCERNED WENT WITH A BLEND OF MEX AND GMOS FOR
MOST PERIODS. ALSO WENT CLOSE TO ENSEMBLE GUIDANCE FOR MONDAY NIGHT
AND TUESDAY. AS FAR AS POPS ARE CONCERN WENT CLOSE TO MEX GUIDANCE
FOR MOST PERIODS AND ADJUSTED MEN GUIDANCE FOR MONDAY NIGHT INTO
TUESDAY./17/
&&
.AVIATION...MVFR CEILINGS LOOK TO RISE TO VFR BY 18Z THEN CLEARING
ALTOGETHER AFTER 07/00Z. VISIBILITIES SHOULD REMAIN MOSTLY VFR. SOME
RESTRICTIONS MAY DEVELOP FROM KJAN/KHKS...KMEI AND KHBG FROM 16-22Z
IN RAIN AND SNOW SHOWERS AND BRIEFLY DROP TO MVFR./26/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/26/17
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
809 PM CST Fri Feb 7 2014
.UPDATE:
Issued at 806 PM CST Fri Feb 7 2014
Quick update to the forecast to boost POPs generally north of
Interstate 70 after midnight where both RAP and latest NAM show
area of light snow developing ahead of the approaching shortwave
in weak warm advection. Up to a tenth of an inch of liquid could
lead to an inch of snow for locations along a Mexico, Bowling
Green, White Hall line. Outside of this area lighter snow totals
of less than a half of an inch are expected from Columbia to the
northern St. Louis Metro. Will continue to monitor radar trends
and adjust short term grids accordingly.
CVKING
&&
.SHORT TERM: (Through Late Tonight)
Issued at 325 PM CST Fri Feb 7 2014
This afternoon: a pair of well-sheared upper level shortwave
disturbances exist, one to our north and the other to our south in
what is largely a zonal flow regime over the central U.S. The core
of the Arctic airmass continues to dominate our region but is now to
our east over SW Indiana as a 1032mb hi pressure. An extensive area
of clouds once again exists mainly to our W and S, but unlike 24hrs
ago, these clouds will be invading to stay for a while, with many
areas already cloudy now. Temps have been able to get into the
teens today, with areas able to remain sunny the longest likely to
hit 20F before sundown.
The well-sheared shortwave disturbances will remain to our north and
south and have no effect on our wx, exiting to the east by midnight.
However, another stronger shortwave TROF over the west TX panhandle
will shoot east, interacting with the tail end of the first southern
wave, with some decent potential of a period or two of light snow
for late this evening and the early part of the overnight. Yet
another shortwave, currently over the Pac NW, will make an approach
to our northern CWA towards 12z with increasing PoPs for light snow
there.
What is left in-between for much of tonight will be a gradually
lowering deck of clouds in a broadscale, weak WAA regime. We have
had lo chance PoPs in place for sometime now and cannot rule out
areas of light snow developing, especially given how KMCI has had a
couple hours of flurries this afternoon. Will leave these lo PoPs
in place to maintain the mention with localized dustings of snow
possible.
Cloudy skies and gradually increasing S flow are expected to result
in min temps at many locations being hit during the evening with
steady or slightly rising temps overnight. Generally went at or
below the lowest MOS values for IL sites and northeast MO, with more
of a MOS blend elsewhere where the clouds are more firmly
established.
TES
.LONG TERM: (Saturday through Next Friday)
Issued at 325 PM CST Fri Feb 7 2014
Low-mid level waa is expected on Saturday ahead of a shortwave and
associated weak surface low which will move ewd through IA and nrn
IL. It appears that most of the snow will remain n-ne of our
forecast area ahead and north of the track of the vort max/sfc
low, but there may be a little light snow over nern MO and w cntrl
IL and flurries elsewhere. Could also not rule out a little
drizzle or freezing drizzle as some of the forecast soundings
indicate shallow moisture/cloud cover with a lack of ice crystals
in this low level cloud deck at times. S-swly sfc/low level winds
ahead of the weak surface low and trailing cold front will lead to
warmer temperatures on Saturday, likely rising above the freezing
mark across portions of cntrl and sern MO. The models were a
little slower with the progression of the cold front dropping sewd
through our forecast area Saturday night and Sunday mrng. The
models lag the 850 mb front well behind the sfc cold front with
continued low-mid level waa over the surface cold front Saturday
ngt and Sunday mrng mainly across the srn portion of our forecast
area. The models, particularly the NAM also depict some low-mid
level frontogenesis across our area late Saturday ngt and Sunday.
The models qpf forecast also seem to be hinting at a possible W-E
band of snow moving swd through our forecast area from late
Saturday ngt through Sunday evng. Still a lot of uncertainty in
the precipitation forecast for Saturday ngt through Sunday ngt,
but there may be the potential for some areas to pick up 1-3 inches
of snow. Colder air will filter slowly swd into our forecast area
Sunday and Sunday ngt as a strong 1035-1040 mb surface ridge
builds sewd into our area. Wind chills will drop to around 15 to
20 below zero late Sunday ngt and early Monday mrng across nern MO
and w cntrl IL. There may still be a chance of snow across
portions of sern MO and swrn IL on Monday as weak nw flow
shortwaves continue to drop sewd through our region and a storm
system passes to our south, but most of the precipitation should be
south of the forecast area by Monday as the cold and dry air mass
continues to build s-sewd through MO and IL. The extended forecast
appears dry as the models keep the shortwave energy either well
north or south of our forecast area. As sly surface winds return
later in the work week as the surface high shifts east of the
region we should see warmer temperatures by Wednesday and
Thursday.
GKS
&&
.AVIATION: (For the 00z TAFs through 00z Saturday Evening)
Issued at 551 PM CST Fri Feb 7 2014
Surface ridge has moved off to the east allowing southerly winds
to return to the region. In the meantime, systems are passing just
to our south and just to our north with clouds on the increase.
Will see clouds lower to mvfr late tonight as clipper system
slides southeast towards forecast area with main energy staying
north of region. Some light snow is possible, mainly over KUIN
with mvfr vsbys through 18z Saturday. Mvfr cigs to persist through
rest of forecast period.
Specifics for KSTL:
Surface ridge has moved off to the east allowing southeasterly to
southerly winds to return to the region. In the meantime, systems
are passing just to our south and just to our north with clouds on
the increase. Will see clouds lower to mvfr by 14z Saturday as
clipper system slides southeast towards forecast area with main
energy staying north of region. Some light snow/flurries is
possible but kept taf dry for now. Mvfr cigs to persist through
rest of forecast period.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
958 PM EST FRI FEB 7 2014
.SYNOPSIS...
HIGH PRESSURE WILL HOLD ACROSS THE AREA OVERNIGHT. LOW PRESSURE
WILL DEVELOP OFF THE SOUTHEAST U.S. COAST LATE TONIGHT...AND
INTENSIFY AS IT ACCELERATES NE...AWAY FROM THE U.S. MAINLAND
DURING SATURDAY. A BRIEF WARM UP IS EXPECTED SUNDAY AHEAD OF A
COLD FRONT THAT WILL CROSS THE CAROLINAS EARLY MONDAY. COLD HIGH
PRESSURE WILL RIDGE ACROSS THE AREA MONDAY THRU TUESDAY...AND GIVE
WAY TO DEVELOPING LOW PRESSURE FROM THE GULF OF MEXICO DURING THE
MIDDLE PORTIONS OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 930 PM FRIDAY...BASED ON LATEST IR 11-3.9 MICRON SAT
IMAGERY...HAVE UPDATED SKY CONDITIONS FOR THE REMAINDER OF THIS
EVENING AND OVERNIGHT. CONTINUED THE TREND OF BECOMING COMPLETELY
OVC DURING THE PRE-DAWN SAT HOURS. FAST EASTWARD MOVING MID-LEVEL
SOUTHERN STREAM S/W TROF...WILL REACH THE FLORIDA PAN HANDLE BY
DAYBREAK SAT. PLENTY OF ATLANTIC AND GULF MOISTURE AVBL AS
OVERRUNNING CLOUDINESS DEVELOPS AND PUSHES OVERHEAD MAINLY IN
EARNEST AFTER MIDNIGHT TONIGHT. LATEST HRRR INDICATES STRATIFORM
RAINS TO BREAKOUT AND/OR PUSH INLAND FROM THE COAST DURING THE
PRE-DAWN SAT HOURS. BY DAYBREAK...THE MAJORITY...IF NOT ALL OF
THE ILM CWA...WILL HAVE LIGHT TO POSSIBLY MODERATE STRATIFORM TYPE
RAINS FALLING/OCCURRING. LATEST WINTER TYPE PCPN PARAMETERS REMAIN
CONDUCIVE TO AN ALL LIQUID RAIN EVENT...IE. NO P-TYPE ISSUES FOR
THE ILM CWA. RE-ADJUSTED TONIGHTS LOWS TO OCCUR AROUND OR JUST
AFTER MIDNIGHT WITH MAINLY STEADY TEMPS THERE-AFTER AS CLDS AND
PCPN OVERTAKE THE FORECAST AREA.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...LOW PRESSURE WILL DEVELOP ALONG A BOUNDARY
STALLED OFF THE FL EAST COAST FRI NIGHT THEN TRACK NORTHEAST JUST
OFF THE CAROLINA COAST SAT. ALTHOUGH THE LOW WILL PASS OFF THE
COAST IT WILL BE CLOSE ENOUGH TO SPREAD RAIN OVER THE FORECAST
AREA. RAIN WILL BE ONGOING AS THE PERIOD BEINGS WITH INCREASING
ISENTROPIC LIFT AS THE LOW DEEPENS TAPPING INTO ABUNDANT MOISTURE.
CLOSER TO THE COAST...WHERE MOISTURE IS HIGHEST AND LIFT
STRONGEST...PERIODS OF MODERATE RAIN WILL BE POSSIBLE THROUGH SAT
MORNING. BROAD MID LEVEL TROUGHING OVER MUCH OF THE COUNTRY WILL
BE QUICK TO HUSTLE THE LOW NORTHEAST DURING THE DAY SAT AND BY
EVENING IT WILL BE WELL EAST OF HATTERAS WITH ONLY LOW LEVEL
MOISTURE LINGERING OVER THE REGION. COMBINATION OF CLOUD
COVER...RAIN...AND NORTHERLY WINDS WILL KEEP HIGHS WELL BELOW
CLIMO SAT. MANY AREAS WILL STRUGGLE TO REACH 50.
AS THE LOW DEPARTS HIGH PRESSURE FROM THE SOUTHERN PLAINS WEAKLY
BUILDS INTO THE REGION. MID LEVEL TROUGH AXIS REMAINS WEST OF THE
REGION SO THERE WILL BE NO COLD ADVECTION SAT NIGHT. LOW LEVEL
MOISTURE LINGERS INTO SUN...KEEPING SKIES CLOUDY BUT MOISTURE IS
SHALLOW ENOUGH THAT PRECIP SHOULD NOT BE AN ISSUE. AFOREMENTIONED
LACK OF COLD ADVECTION AND CLOUD COVER WILL KEEP LOWS NEAR CLIMO SAT
NIGHT.
FIRST IN A SERIES OF WEAK SHORTWAVES PASSES OVERHEAD SUN MORNING
WITH SUBSIDENCE IN ITS WAKE AND MIXING HELPING TO ERODE LOW LEVEL
MOISTURE. SKIES WILL BE MOSTLY SUNNY FOR MUCH OF THE DAY BEFORE
CIRRUS ASSOCIATED WITH UPPER MOISTURE AHEAD OF THE NEXT SHORTWAVE
SPREADS OVER THE REGION. ANOTHER COLD FRONT WILL DROP IN FROM THE
NORTHWEST SUN NIGHT BUT THE BOUNDARY STALLS OVER THE SOUTHERN PART
OF THE REGION AS THE PERIOD ENDS. ALTHOUGH THE FRONT WILL LACK
PRECIP IT WILL BRING A SIGNIFICANT INCREASE IN CLOUD COVER. TEMPS
WILL BE NEAR CLIMO SUN AND SUN NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...COLD FRONT WILL DROP SOUTH THROUGH THE
CAROLINAS ON MONDAY BUT WITH A VERY BROAD MID TO UPPER TROUGH
DRAPED ACROSS THE EASTERN CONUS THE FLOW ALOFT WILL REMAIN FAIRLY
ZONAL WITH A DECENT W-SW COMPONENT TO THE FLOW. THEREFORE THE
SHALLOW COOL AIR WILL REINFORCE THE WEDGE WITH LOW CLOUDS AND LOW
END PCP DEVELOPING AS ISENTROPIC LIFT SLOWLY INCREASES BY THE END
OF THE DAY. LOOKS LIKE ENOUGH DRYING WILL OCCUR BEHIND FRONT TO
SQUEEZE OUT A DRY DAY FOR MONDAY...BUT MAY CONTINUE TO SEE A GOOD
DEAL OF CLOUDS.
BY EARLY TUES ISENTROPIC LIFT INCREASES ACROSS THE CAROLINAS LEADING
TO CLOUDS AND INCREASED CHC OF RAIN. BY LATE TUES INTO WED A WAVE OF
LOW PRESSURE MOVING ALONG THE GULF COAST WILL ACT TO ENHANCE THE
WEDGE PATTERN SHARPENING THE COASTAL TROUGH/WARM FRONT EXTENDING UP
THE SOUTHEAST COAST. THE BEST LIFT WILL COME AHEAD OF SHORTWAVE
RIDING THROUGH THE SOUTHEAST TUES NIGHT INTO WEDNESDAY. OVERALL
EXPECT UNSETTLED WEATHER WITH CLOUDS AND PCP OVER THE AREA FROM TUES
THROUGH EARLY THURS. THERE MAY BE ENOUGH COOL AIR IN PLACE TO
PRODUCE SOME MIXED PCP WITH THIS SYSTEM AS TEMPS REMAIN BORDERLINE.
SHOULD SEE A BREAK IN PCP ON THURS BUT A NORTHERN STREAM SYSTEM WILL
FOLLOW CLOSE BEHIND TO PRODUCE INCREASED CHC OF PCP BY THURS NIGHT.
CLOUDS MAY NOT HAVE AN OPPORTUNITY TO CLEAR BEFORE THIS NEXT SYSTEM
COMES BUT BY FRIDAY...THE SHORTWAVE TROUGH AXIS WILL MOVE OFF SHORE
ALLOWING A DEEP DRY AND COOL NW FLOW TO DEVELOP SCOURING OUT ALL
MOISTURE AS HIGH PRESSURE BUILDS IN LATE FRI INTO SATURDAY.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...EXPECT VFR THROUGH THE LATE OVERNIGHT HOURS...WITH
CONDITIONS GRADUALLY DETERIORATING TO MVFR/IFR ON SATURDAY DUE TO
LOW CIGS...AREAS OF FOG...AND PERIODS OF HEAVY RAINFALL.
LIGHT WINDS AND VFR PREVAIL THIS EVENING AT ALL TERMINALS WITH THE
LATEST 11U-3.9U SATELLITE IMAGERY ILLUSTRATING HIGH CLOUDS
INFILTRATING INTO THE AREA. ANTICIPATE HIGH CLOUD COVER TO INCREASE
IN COVERAGE BECOMING BKN WITH MID CLOUDS SLOWLY MOVING IN AS WELL
AHEAD OF LOW PRESSURE SET TO MOVE UP THE COAST THROUGHOUT THE PERIOD.
ON SATURDAY...EXPECT NORTH-NORTHEAST WINDS TO INCREASE TO AOB 10
KTS FOR THE DAY. LATEST TIME-HEIGHT ANALYSIS AND FCST SOUNDINGS
SUPPORT RAINFALL TO BECOME WIDESPREAD ACROSS THE AREA BY
MORNING...WITH MVFR/IFR CONDITIONS DUE TO LOW CIGS...AREAS OF
FOG...AND PERIODS OF HEAVY RAINFALL. ATTM WOULD ANTICIPATE RAINFALL
TO TAPER OFF INTO THE EVENING HOURS ON SATURDAY AS CONDITIONS
IMPROVE TO MVFR TOWARDS THE END OF THE PERIOD...POSSIBLY VFR INLAND.
EXTENDED OUTLOOK...VFR EXPECTED THROUGH MONDAY AFTERNOON.
DETERIORATING CONDITIONS MONDAY NIGHT WITH MODERATE CONFIDENCE FOR
IFR CONDITIONS IN PRECIP TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 945 PM FRIDAY...WEAK RIDGING FROM THE NORTH THIS EVENING...
WILL GIVE WAY TO A DEVELOPING SFC LOW OFF THE SOUTHEAST U.S.
MAINLAND LATE TONIGHT. THE SFC PRESSURE PATTERN AND GRADIENT WILL
BEGIN TO MODIFY DURING THE PRE-DAWN SAT HOURS...WITH LIGHT NE
WINDS INCREASING TO 10-20 KT ACROSS THE LOCAL WATERS WITH FEW
GUSTS UP TO 25 KT. SIGNIFICANT SEAS AT THEIR LOWEST THIS
EVENING...WILL BEGIN TO BUILD DURING THE PRE-DAWN SAT HRS IN
RESPONSE TO THE INCREASING LOCALLY PRODUCED WIND DRIVEN WAVES.
LOOKING AT SIG SEAS OF 2 TO 4 FT...BUILDING TO 3 TO 5 FT BY
DAYBREAK SAT...WITH SOME 6 FOOTERS POSSIBLE OFF CAPE FEAR AND/OR
OFF THE MOUTH OF WINYAH BAY. AVERAGE PERIODS WILL RUN JUST SHY OF
5.0 SECONDS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...PINCHED GRADIENT AT THE START OF THE PERIOD AS
DEVELOPING LOW PASSES JUST EAST OF THE WATERS WILL PUSH NORTH TO
NORTHEAST FLOW TO A SOLID 20 KT DURING THE DAY. ALTHOUGH WINDS MAY
END UP JUST SHORT OF SCA THINK SEAS WILL EXCEED 6 FT IN OUTER WATERS
AND WILL RAISE A 12 HOUR SCA FOR ALL ZONES. TIME DURATION IS LIKELY
A LITTLE LONG ON THE BACKSIDE OF THE ADVISORY BUT IT CAN BE
CANCELLED EARLY IF NEED BE.
ONCE THE SURFACE LOW RAPIDLY DEPARTS LATE SAT INTO SAT NIGHT THE
GRADIENT BECOMES WEAK AND ILL DEFINED. BY MIDNIGHT NORTHERLY FLOW
WILL BE UNDER 10 KT AND SEAS DROP TO 2 TO 3 FT BY SUN MORNING. HIGH
PRESSURE BUILDING IN FROM THE WEST MAINTAINS NORTHERLY FLOW INTO SUN
BEFORE WINDS FLOP TO SOUTHERLY WITH WEAK RIDGE AXIS SHIFTING
OFFSHORE. WEAK COLD FRONT DROPPING IN FROM THE NORTH LATE SUN
INCREASES SOUTHWEST FLOW IN THE AFTERNOON AND EVENING BUT SPEEDS
WILL REMAIN UNDER 15 KT. FRONT STALLS ACROSS OR JUST SOUTH OF THE
WATERS LATE SUN NIGHT. IN THE VICINITY OF THE FRONT WINDS WILL BE
UNDER 10 KT WITH VARIABLE DIRECTION...ACROSS NORTHERN ZONES WINDS
WILL HAVE MORE OF A NORTHWEST COMPONENT. INCREASE IN SPEEDS SUN
PUSHES 2 TO 3 FT SEAS TO 2 TO 4 FT FOR SUN AFTERNOON AND SUN NIGHT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 PM FRIDAY...COLD FRONT DROPPING SOUTH EARLY MON WILL
PRODUCE A SHARP SHIFT IN WINDS TO THE NORTH THEN NORTHEAST. THIS
WILL LEAD TO WEDGE PATTERN SETTING UP FOR MID WEEK AS WAVE OF LOW
PRESSURE RIDES ACROSS THE GULF COAST ENHANCING THE COASTAL TROUGH
UP THROUGH THE SOUTHEAST ATLANTIC WATERS. WILL SEE NORTHEAST FLOW
SHARPENING UP BY TUES NIGHT AS GRADIENT TIGHTENS BETWEEN WEDGE OF
HIGH PRESSURE INLAND AND TROUGH OFF THE COAST. EXPECT WINDS TO
INCREASE TO 15 TO 20 KTS INTO MON NIGHT INTO TUES WITH A PROLONGED
PERIOD OF ADVISORY CONDITIONS POSSIBLE TUES THROUGH WED
NIGHT...MAINLY IN OUTER WATERS. WINDS IN LOCAL WATERS MAY REMAIN
NORTHEAST BUT THE SHARPENING TROUGH MAY BRING SOUTHEAST WINDS INTO
THE OUTER WATERS ON WED. THE SYSTEM LIFTS OFF TO THE NORTHEAST BY
EARLY THURS LEAVING A LIGHTER NORTHEAST FLOW BEHIND. SEAS OF 2-3
FT EARLY IN THE PERIOD ON MONDAY WILL RISE STEADILY...BECOMING 4-6
FT THROUGH TUESDAY INTO WED BEFORE FINALLY SUBSIDING BY EARLY
THURS AS SYSTEM LIFTS OFF TO THE NORTHEAST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 7 PM EST SATURDAY FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...III
NEAR TERM...DCH
SHORT TERM...III
LONG TERM...RGZ
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
717 PM EST FRI FEB 7 2014
.SYNOPSIS...
HIGH PRESSURE WILL HOLD ACROSS THE AREA THROUGH OVERNIGHT. LOW
PRESSURE WILL PASS OFFSHORE SATURDAY BRINGING PERIODS OF RAIN TO
THE REGION. A BRIEF WARM UP IS EXPECTED SUNDAY AHEAD OF A COLD FRONT
THAT WILL CROSS THE CAROLINAS EARLY MONDAY. A STORM SYSTEM FROM
THE GULF OF MEXICO WILL BRING WET CONDITIONS DURING THE MIDDLE
PORTIONS OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 645 PM FRIDAY...BASED ON LATEST IR 11-3.9 MICRON SAT
IMAGERY...HAVE UPDATED SKY CONDITIONS FOR THIS EVENING. AND
CONTINUED THE TREND OF BECOMING COMPLETELY OVC DURING THE PRE-DAWN
SAT HOURS. FAST EASTWARD MOVING MID-LEVEL SOUTHERN STREAM S/W TROF
TO REACH THE FLORIDA PAN HANDLE BY DAYBREAK SAT. PLENTY OF
ATLANTIC AND GULF MOISTURE AVBL AS OVERRUNNING CLOUDINESS DEVELOPS
AND PUSHES OVERHEAD MAINLY IN EARNEST AFTER MIDNIGHT TONIGHT.
LATEST HRRR INDICATES STRATIFORM RAINS TO BREAKOUT AND/OR PUSH
INLAND FROM THE COAST DURING THE PRE-DAWN SAT HOURS. AND BY
DAYBREAK...THE MAJORITY...IF NOT ALL OF THE ILM CWA...WILL HAVE
LIGHT TO POSSIBLY MODERATE STRATIFORM TYPE RAINS
FALLING/OCCURRING. LATEST WINTER TYPE PCPN PARAMETERS REMAIN
CONDUCIVE TO AN ALL LIQUID RAIN EVENT...NO PTYPE ISSUES FOR THE
ILM CWA. RE-ADJUSTED TONIGHTS LOWS TO OCCUR AROUND OR JUST AFTER
MIDNIGHT WITH MAINLY STEADY TEMPS THERE-AFTER AS CLDS AND PCPN
OVERTAKE THE FORECAST AREA.
PREVIOUS DISCUSSION..............................................
AS OF 3 PM FRIDAY...FAIR SKIES AND COOL TEMPERATURES WILL PERSIST
THROUGH THE AFTERNOON HOURS WITH AS A THIN DECK OF CIRRUS
CONTINUES TO STREAM OVERHEAD. TEMPERATURES ARE NOW IN THE UPPER
40S MOST PLACES AND WILL REACH THE PREVIOUSLY FORECAST LOWER 50S
WITHIN THE NEXT COUPLE OF HOURS.
WEAK HIGH PRESSURE OVERHEAD AND LIGHT WINDS AT THE SURFACE THIS
EVENING MEANS TEMPERATURES WILL QUICKLY DROP BACK INTO THE LOWER 40S
AND UPPER 30S BY MIDNIGHT. KEEPING A LID ON TEMPERATURES AFTER THAT
TIME WILL BE INCREASING CLOUD COVER AS A LOW PRESSURE SYSTEM DEEPENS
AND MOVES RAPIDLY NORTHEAST ALONG A STALLED BOUNDARY OFFSHORE. THIS
SYSTEM WILL BRING INCREASING CHANCES OF RAIN OVERNIGHT. BY DAYBREAK
OUR SC COUNTIES WILL LIKELY BE SEEING STRATIFORM RAIN...WITH CHANCE
POPS FOR OUR NC COUNTIES.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...LOW PRESSURE WILL DEVELOP ALONG A BOUNDARY
STALLED OFF THE FL EAST COAST FRI NIGHT THEN TRACK NORTHEAST JUST
OFF THE CAROLINA COAST SAT. ALTHOUGH THE LOW WILL PASS OFF THE
COAST IT WILL BE CLOSE ENOUGH TO SPREAD RAIN OVER THE FORECAST
AREA. RAIN WILL BE ONGOING AS THE PERIOD BEINGS WITH INCREASING
ISENTROPIC LIFT AS THE LOW DEEPENS TAPPING INTO ABUNDANT MOISTURE.
CLOSER TO THE COAST...WHERE MOISTURE IS HIGHEST AND LIFT
STRONGEST...PERIODS OF MODERATE RAIN WILL BE POSSIBLE THROUGH SAT
MORNING. BROAD MID LEVEL TROUGHING OVER MUCH OF THE COUNTRY WILL
BE QUICK TO HUSTLE THE LOW NORTHEAST DURING THE DAY SAT AND BY
EVENING IT WILL BE WELL EAST OF HATTERAS WITH ONLY LOW LEVEL
MOISTURE LINGERING OVER THE REGION. COMBINATION OF CLOUD
COVER...RAIN...AND NORTHERLY WINDS WILL KEEP HIGHS WELL BELOW
CLIMO SAT. MANY AREAS WILL STRUGGLE TO REACH 50.
AS THE LOW DEPARTS HIGH PRESSURE FROM THE SOUTHERN PLAINS WEAKLY
BUILDS INTO THE REGION. MID LEVEL TROUGH AXIS REMAINS WEST OF THE
REGION SO THERE WILL BE NO COLD ADVECTION SAT NIGHT. LOW LEVEL
MOISTURE LINGERS INTO SUN...KEEPING SKIES CLOUDY BUT MOISTURE IS
SHALLOW ENOUGH THAT PRECIP SHOULD NOT BE AN ISSUE. AFOREMENTIONED
LACK OF COLD ADVECTION AND CLOUD COVER WILL KEEP LOWS NEAR CLIMO SAT
NIGHT.
FIRST IN A SERIES OF WEAK SHORTWAVES PASSES OVERHEAD SUN MORNING
WITH SUBSIDENCE IN ITS WAKE AND MIXING HELPING TO ERODE LOW LEVEL
MOISTURE. SKIES WILL BE MOSTLY SUNNY FOR MUCH OF THE DAY BEFORE
CIRRUS ASSOCIATED WITH UPPER MOISTURE AHEAD OF THE NEXT SHORTWAVE
SPREADS OVER THE REGION. ANOTHER COLD FRONT WILL DROP IN FROM THE
NORTHWEST SUN NIGHT BUT THE BOUNDARY STALLS OVER THE SOUTHERN PART
OF THE REGION AS THE PERIOD ENDS. ALTHOUGH THE FRONT WILL LACK
PRECIP IT WILL BRING A SIGNIFICANT INCREASE IN CLOUD COVER. TEMPS
WILL BE NEAR CLIMO SUN AND SUN NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...COLD FRONT WILL DROP SOUTH THROUGH THE
CAROLINAS ON MONDAY BUT WITH A VERY BROAD MID TO UPPER TROUGH
DRAPED ACROSS THE EASTERN CONUS THE FLOW ALOFT WILL REMAIN FAIRLY
ZONAL WITH A DECENT W-SW COMPONENT TO THE FLOW. THEREFORE THE
SHALLOW COOL AIR WILL REINFORCE THE WEDGE WITH LOW CLOUDS AND LOW
END PCP DEVELOPING AS ISENTROPIC LIFT SLOWLY INCREASES BY THE END
OF THE DAY. LOOKS LIKE ENOUGH DRYING WILL OCCUR BEHIND FRONT TO
SQUEEZE OUT A DRY DAY FOR MONDAY...BUT MAY CONTINUE TO SEE A GOOD
DEAL OF CLOUDS.
BY EARLY TUES ISENTROPIC LIFT INCREASES ACROSS THE CAROLINAS LEADING
TO CLOUDS AND INCREASED CHC OF RAIN. BY LATE TUES INTO WED A WAVE OF
LOW PRESSURE MOVING ALONG THE GULF COAST WILL ACT TO ENHANCE THE
WEDGE PATTERN SHARPENING THE COASTAL TROUGH/WARM FRONT EXTENDING UP
THE SOUTHEAST COAST. THE BEST LIFT WILL COME AHEAD OF SHORTWAVE
RIDING THROUGH THE SOUTHEAST TUES NIGHT INTO WEDNESDAY. OVERALL
EXPECT UNSETTLED WEATHER WITH CLOUDS AND PCP OVER THE AREA FROM TUES
THROUGH EARLY THURS. THERE MAY BE ENOUGH COOL AIR IN PLACE TO
PRODUCE SOME MIXED PCP WITH THIS SYSTEM AS TEMPS REMAIN BORDERLINE.
SHOULD SEE A BREAK IN PCP ON THURS BUT A NORTHERN STREAM SYSTEM WILL
FOLLOW CLOSE BEHIND TO PRODUCE INCREASED CHC OF PCP BY THURS NIGHT.
CLOUDS MAY NOT HAVE AN OPPORTUNITY TO CLEAR BEFORE THIS NEXT SYSTEM
COMES BUT BY FRIDAY...THE SHORTWAVE TROUGH AXIS WILL MOVE OFF SHORE
ALLOWING A DEEP DRY AND COOL NW FLOW TO DEVELOP SCOURING OUT ALL
MOISTURE AS HIGH PRESSURE BUILDS IN LATE FRI INTO SATURDAY.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...EXPECT VFR THROUGH THE LATE OVERNIGHT HOURS...WITH
CONDITIONS GRADUALLY DETERIORATING TO MVFR/IFR ON SATURDAY DUE TO
LOW CIGS...AREAS OF FOG...AND PERIODS OF HEAVY RAINFALL.
LIGHT WINDS AND VFR PREVAIL THIS EVENING AT ALL TERMINALS WITH THE
LATEST 11U-3.9U SATELLITE IMAGERY ILLUSTRATING HIGH CLOUDS
INFILTRATING INTO THE AREA. ANTICIPATE HIGH CLOUD COVER TO INCREASE
IN COVERAGE BECOMING BKN WITH MID CLOUDS SLOWLY MOVING IN AS WELL
AHEAD OF LOW PRESSURE SET TO MOVE UP THE COAST THROUGHOUT THE PERIOD.
ON SATURDAY...EXPECT NORTH-NORTHEAST WINDS TO INCREASE TO AOB 10
KTS FOR THE DAY. LATEST TIME-HEIGHT ANALYSIS AND FCST SOUNDINGS
SUPPORT RAINFALL TO BECOME WIDESPREAD ACROSS THE AREA BY
MORNING...WITH MVFR/IFR CONDITIONS DUE TO LOW CIGS...AREAS OF
FOG...AND PERIODS OF HEAVY RAINFALL. ATTM WOULD ANTICIPATE RAINFALL
TO TAPER OFF INTO THE EVENING HOURS ON SATURDAY AS CONDITIONS
IMPROVE TO MVFR TOWARDS THE END OF THE PERIOD...POSSIBLY VFR INLAND.
EXTENDED OUTLOOK...VFR EXPECTED THROUGH MONDAY AFTERNOON.
DETERIORATING CONDITIONS MONDAY NIGHT WITH MODERATE CONFIDENCE FOR
IFR CONDITIONS IN PRECIP TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 645 PM FRIDAY...WEAK RIDGING FROM THE NORTH THIS
EVENING...WILL GIVE WAY TO A DEVELOPING SFC LOW OFF THE SOUTHEAST
U.S. MAINLAND LATE TONIGHT. THE SFC PRESSURE PATTERN AND GRADIENT
WILL BEGIN TO MODIFY DURING THE PRE-DAWN SAT HOURS...WITH LIGHT NE
WINDS INCREASING TO 10-20 KT ACROSS THE LOCAL WATERS WITH FEW
GUSTS UP TO 25 KT LATE. SIGNIFICANT SEAS AT THEIR LOWEST THIS
EVENING...WILL BEGIN TO BUILD DURING THE PRE-DAWN SAT HRS IN
RESPONSE TO THE INCREASING LOCALLY PRODUCED WIND DRIVEN WAVES.
LOOKING AT SIG SEAS OF 2 TO 4 FT...BUILDING TO 3 TO 5 FT BY
DAYBREAK SAT. AVERAGE PERIODS WILL RUN JUST SHY OF 5.0 SECONDS.
PREVIOUS DISCUSSION...........................................
AS OF 3 PM FRIDAY...WEAK HIGH PRESSURE OVER THE CAROLINAS
COMBINED WITH A STALLED FRONT EAST OF THE WATERS WILL ALLOW
PRESENT NORTHEASTERLY FLOW TO PERSIST THROUGH THE REMAINDER OF THE
AFTERNOON AND OVERNIGHT HOURS. WINDS WILL BE IN THE 10 TO 15 KT
RANGE THROUGH THE PERIOD...CLOSER TO 10 KTS BEFORE MIDNIGHT...THEN
INCREASING TO AROUND 15 KTS IN THE EARLY MORNING HOURS AS A
DEEPENING LOW PRESSURE SYSTEM RACES EAST OF THE WATERS. SEAS WILL
BE IN THE 2 TO 4 FT RANGE FOR MUCH OF THE TIME...ALTHOUGH WE MAY
SEE SOME 5 FOOTERS BY DAYBREAK ON SATURDAY OVER THE OUTER FRINGES
OF THE WATERS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...PINCHED GRADIENT AT THE START OF THE PERIOD AS
DEVELOPING LOW PASSES JUST EAST OF THE WATERS WILL PUSH NORTH TO
NORTHEAST FLOW TO A SOLID 20 KT DURING THE DAY. ALTHOUGH WINDS MAY
END UP JUST SHORT OF SCA THINK SEAS WILL EXCEED 6 FT IN OUTER WATERS
AND WILL RAISE A 12 HOUR SCA FOR ALL ZONES. TIME DURATION IS LIKELY
A LITTLE LONG ON THE BACKSIDE OF THE ADVISORY BUT IT CAN BE
CANCELLED EARLY IF NEED BE.
ONCE THE SURFACE LOW RAPIDLY DEPARTS LATE SAT INTO SAT NIGHT THE
GRADIENT BECOMES WEAK AND ILL DEFINED. BY MIDNIGHT NORTHERLY FLOW
WILL BE UNDER 10 KT AND SEAS DROP TO 2 TO 3 FT BY SUN MORNING. HIGH
PRESSURE BUILDING IN FROM THE WEST MAINTAINS NORTHERLY FLOW INTO SUN
BEFORE WINDS FLOP TO SOUTHERLY WITH WEAK RIDGE AXIS SHIFTING
OFFSHORE. WEAK COLD FRONT DROPPING IN FROM THE NORTH LATE SUN
INCREASES SOUTHWEST FLOW IN THE AFTERNOON AND EVENING BUT SPEEDS
WILL REMAIN UNDER 15 KT. FRONT STALLS ACROSS OR JUST SOUTH OF THE
WATERS LATE SUN NIGHT. IN THE VICINITY OF THE FRONT WINDS WILL BE
UNDER 10 KT WITH VARIABLE DIRECTION...ACROSS NORTHERN ZONES WINDS
WILL HAVE MORE OF A NORTHWEST COMPONENT. INCREASE IN SPEEDS SUN
PUSHES 2 TO 3 FT SEAS TO 2 TO 4 FT FOR SUN AFTERNOON AND SUN NIGHT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 PM FRIDAY...COLD FRONT DROPPING SOUTH EARLY MON WILL
PRODUCE A SHARP SHIFT IN WINDS TO THE NORTH THEN NORTHEAST. THIS
WILL LEAD TO WEDGE PATTERN SETTING UP FOR MID WEEK AS WAVE OF LOW
PRESSURE RIDES ACROSS THE GULF COAST ENHANCING THE COASTAL TROUGH
UP THROUGH THE SOUTHEAST ATLANTIC WATERS. WILL SEE NORTHEAST FLOW
SHARPENING UP BY TUES NIGHT AS GRADIENT TIGHTENS BETWEEN WEDGE OF
HIGH PRESSURE INLAND AND TROUGH OFF THE COAST. EXPECT WINDS TO
INCREASE TO 15 TO 20 KTS INTO MON NIGHT INTO TUES WITH A PROLONGED
PERIOD OF ADVISORY CONDITIONS POSSIBLE TUES THROUGH WED
NIGHT...MAINLY IN OUTER WATERS. WINDS IN LOCAL WATERS MAY REMAIN
NORTHEAST BUT THE SHARPENING TROUGH MAY BRING SOUTHEAST WINDS INTO
THE OUTER WATERS ON WED. THE SYSTEM LIFTS OFF TO THE NORTHEAST BY
EARLY THURS LEAVING A LIGHTER NORTHEAST FLOW BEHIND. SEAS OF 2-3
FT EARLY IN THE PERIOD ON MONDAY WILL RISE STEADILY...BECOMING 4-6
FT THROUGH TUESDAY INTO WED BEFORE FINALLY SUBSIDING BY EARLY
THURS AS SYSTEM LIFTS OFF TO THE NORTHEAST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 7 PM EST SATURDAY FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...III
NEAR TERM...DCH/REK
SHORT TERM...III
LONG TERM...RGZ
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
255 PM EST THU FEB 6 2014
.SYNOPSIS...A WEAK UPPER LEVEL DISTURBANCE WILL CROSS THE REGION
THIS EVENING. POLAR HIGH PRESSURE WILL OTHERWISE BUILD EAST ACROSS
THE MIDDLE ATLANTIC STATES THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 100 PM THURSDAY...
REST OF TODAY: AS OF 17Z...BROKEN CLOUD COVER OVER THE CAROLINAS IS
ASSOCIATED WITH UPPER LEVEL MOISTURE ADVECTING INTO THE REGION VIA
SW FLOW ALOFT (DOWNSTREAM OF A SHORTWAVE TRACKING INTO LOUISIANA) IN
ADDITION TO A NARROW CORRIDOR OF MID-LEVEL (H7-H6) FRONTOGENESIS IN
VICINITY OF A LINE EXTENDING SW-NE FROM TROY-RALEIGH-TARBORO. 17Z
REGIONAL RADAR DATA INDICATED A NARROW BAND OF ECHOES (10-25 DBZ)
THAT CORRESPOND WELL WITH THE AFOREMENTIONED ZONE OF FGEN (MOST
PROMINENT BETWEEN 9000-15000 FT AGL). KRAX IS INDICATING FAINT
ECHOES (5-10 DBZ) AS LOW AS 4000 FT AGL OVER NORTHERN MOORE AND LEE
COUNTIES...IMPRESSIVE CONSIDERING THE DRY MID-LEVEL AIRMASS IN PLACE
AT 12Z THIS MORNING (12Z GSO/MHZ RAOBS). THE LATEST RAP GUIDANCE
INDICATES MID-LEVEL FGEN WANING ALONG/EAST OF HWY 1 BETWEEN 18-
21Z...AND THE BOUNDARY LAYER (SFC-4000 FT AGL) APPEARS DRY ENOUGH TO
PRECLUDE ANY CHANCE FOR PRECIP (ASIDE FROM VIRGA) THIS AFTERNOON.
PER OBSERVATION TRENDS AS OF 17-18Z...HIGH TEMPS APPEAR ON TRACK IN
THE LOWER/MID 40S...TEMPERED SLIGHTLY DUE TO DECREASED INSOLATION
ASSOCIATED WITH MID-LEVEL CLOUD COVER. -VINCENT
TONIGHT: THE SHORTWAVE TROUGH FROM THE RIO GRANDE WILL LIFT QUICKLY
NE ACROSS THE CENTRAL APPALACHIANS AND CAROLINAS THIS EVENING. NWP
GUIDANCE HAS CONTINUED TO TREND TOWARD MORE APPRECIABLE/DEEPER
SATURATION ALOFT...WHICH SHOULD SUPPORT WIDESPREAD VIRGA THIS
EVENING. HOWEVER...THE SUB-CLOUD LAYER WILL REMAIN DRY OWING TO
LITTLE OPPORTUNITY FOR MOISTURE RETURN IN THE WAKE OF THE FRONTAL
ZONE THAT PRESSED SOUTH OF OUR REGION DURING THE PAST 12 HOURS...SO
THE LOWERING MID LEVEL CEILINGS WILL HAVE A DIFFICULT TIME PRODUCING
MORE THAN SCATTERED SPRINKLES OR FLURRIES...PER FORECAST PARTIAL
THICKNESS VALUES THAT FALL IN THE WINTRY MIXTURE PORTION OF THE
NOMOGRAM. IF PRECIPITATION WERE TO FALL FOR A LONGER DURATION OR
WITH A GREATER INTENSITY...WET BULB THERMAL PROFILES IN THE BOUNDARY
LAYER WOULD SUPPORT SNOW...BUT AGAIN...NEITHER CRITERIA ARE EXPECTED
TO BE MET FOR THE REASONS OUTLINED ABOVE. WE WILL...HOWEVER...NEED
TO MONITOR THE MOISTURE RETURN SPREADING INLAND ALONG THE WESTERN
GULF COAST THIS MORNING...WHICH IF IT WERE TO LINK UP WITH THE
AFOREMENTIONED SHORTWAVE TROUGH AND ASSOCIATED MOISTURE...WOULD LEAD
TO A BETTER CHANCE OF LIGHT MEASURABLE PRECIPITATION. AT THIS
TIME...HOWEVER...THAT MOISTURE IS FORECAST TO BE SHUNTED EASTWARD
THROUGH CENTRAL GA/SC AND FAR SOUTHEASTERN NC...THEREBY LIMITING ANY
INTERACTION WITH THE APPROACHING LOWS IN THE UPPER 20S TO LOWER 30S.
FRIDAY: SOMEWHAT OF A REPEAT PERFORMANCE OF THE THE PREVIOUS 24
HOURS...AS YET A NEW SHORTWAVE TROUGH DEAMPLIFIES ON AN ALBEIT
SLIGHTLY MORE NORTHERLY TRACK FROM SW US...WHILE THE MODIFIED ARCTIC
HIGH CONTINUES TO RIDGE AROUND THE APPALACHIANS FROM THE WEST. NOT
AS COOL AS THE PARENT HIGH CONTINUES TO MODIFY...AND IS WEAKENED BY
A SURFACE TROUGH IN THE LEE OF THE APPALACHIANS. HIGHS IN THE UPPER
40S TO LOWER 50S. RIVEN LOWS MOSTLY IN THE LOWER 30S. -MWS
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 255 AM THURSDAY...
FOR FRIDAY NIGHT INTO SATURDAY MORNING A 1030 MB SURFACE HIGH WILL
MOVE ACROSS OHIO AND PENNSYLVANIA WITH A RIDGE EXTENDING DOWN THE
EASTERN SIDE OF THE APPALACHIANS. WHAT BEGINS AS AN INVERTED TROUGH
OFF OF THE COAST OF FLORIDA DEVELOPS INTO A CLOSED LOW OFF OF THE
SC/GA COAST BY 12Z SATURDAY. MODELS DIFFER IN THE TRACK AND TIMING
OF THE LOW WITH THE GFS SLOWER AND FURTHER OFFSHORE AND THE ECMWF
QUICKER AND CLOSER TO THE COAST. THE QUICKER/CLOSER ECMWF CARRIES
THE MOST CONSEQUENCES FOR SENSIBLE WEATHER FOR CENTRAL NC.
THICKNESSES AND WETBULB ZERO TEMPERATURES SUGGEST THAT PRECIPITATION
COULD START OUT AS RAIN OR SNOW WITH THE BEST CHANCES FOR SNOW
FURTHER TO THE NORTH AND WEST...BUT ALSO FURTHER AWAY FROM THE MAIN
MOISTURE SOURCE WHICH WOULD CUT DOWN ANY ACCUMULATION/IMPACTS OF ANY
SNOW THAT DOES FALL INITIALLY. THE SLOWER GFS KEEPS THINGS DRY UNTIL
TEMPERATURES AND THICKNESS INCREASE ENOUGH TO THWART THE THREAT OF
ANY WINTER P-TYPE ISSUES. AFTER 12Z ANY FALLING PRECIP WILL BE
LIQUID WITH THE WETTER ECMWF CARRYING CLOSER TO A HALF AN INCH OF
PRECIP IN THE EAST AND 2 TENTHS OF AN INCH OF THE TRIANGLE WITH LESS
TO THE NORTHWEST. THE GFS ONLY CARRIES 1 TO 2 TENTHS OF AN INCH FROM
THE TRIANGLE EASTWARD. CONFIDENCE IS STILL BELOW AVERAGE ON WHICH OF
THESE SCENARIOS WILL OCCUR BUT WPC PREFERENCES CONTINUE TO BE
WEIGHTED TOWARD THE ECMWF AND THUS WILL INCLUDE THE CHANCE FOR RAIN
OR SNOW IN THE NW THROUGH MID MORNING...AND TRANSITION TO RAIN
THEREAFTER. ALL PRECIPITATION SHOULD EXIT THE EASTERN CWA JUST AFTER
00Z SUNDAY. HIGHS SATURDAY WILL REMAIN COOLER WITH WEDGE IN PLACE
INITIALLY AND THEN OVERCAST THROUGH THE DAY...LOW 40S NW TO NEAR 50
SE. LOWS SATURDAY NIGHT IN THE MID 30S. WITH LOW LEVEL SATURATION
HOLDING THROUGH THE OVERNIGHT HOURS...EXPECT SOME AREAS OF FOG
THROUGH SUNDAY MORNING.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
AS OF 255 PM THURSDAY...
SATURDAY NIGHT...SURFACE LOW OFF THE COAST WILL BE
LIFTING RAPIDLY NORTHEAST..WITH LINGERING LOW LEVEL MOISTURE LOCKED
IN PLACE OVERNIGHT = FOG. SKIES WILL REMAIN CLOUDY WITH PERHAPS SOME
PATCHES OF DRIZZLE WITH TEMPS FALLING INTO THE LOW TO MID 30S.
SUNDAY AND MONDAY FEATURE BROAD TROFFING OVER THE CENTRAL AND
EASTERN CONUS WITH STRONG HIGH PRESSURE BUILDING SOUTH INTO THE
UPPER MIDWEST AND ACROSS THE OHIO VALLEY. SUNDAY WILL BE OUR WARMEST
DAY WITH HIGHS REACHING 50 TO 55 DEGREES. A SHORTWAVE SKIRTS ACROSS
THE NORTHERN TIER OF THE AREA LATER SUNDAY...AND MAY PRODUCE SOME
LIGHT RAIN SHOWERS ACROSS THE NORTHERN TIER LATE IN THE DAY.
HOWEVER...ITS MAIN EFFECT WILL BE TO NUDGE THE LEADING EDGE OF THE
COLDER AIR ACROSS THE OHIO VALLEY SOUTH...EFFECTIVELY A DRY BACKDOOR
COLD FRONT SUNDAY NIGHT. SUNDAY NIGHTS LOWS WILL BE IN THE MID TO
UPPER 20S...AND MONDAYS HIGHS GRADUATED FROM LOW 40S ACROSS THE
NORTH TO NEAR 50 IN THE SOUTHERN TIER.
THE FRONTAL ZONE WILL SET UP SOUTH OF THE AREA AND OFFSHORE AS COLD
AIR CONTINUES TO RIDGE SOUTH THROUGH TUESDAY...REINFORCED BY THE
MIGRATORY 1035MB SURFACE HIGH WANDERING EAST ACROSS SOUTHERN NEW
ENGLAND. HIGHS WILL BE IN THE 40S WITH MOSTLY CLOUDY SKIES DUE TO
MID AND UPPER LEVEL MOISTURE RACING EAST IN FAST NEAR-ZONAL FLOW
ALOFT.
TUESDAY NIGHT THROUGH THURSDAY...OPERATIONAL GFS AND ECMWF DEPICTING
AN ACTIVE SOUTHERN STREAM WITH STRENGTHENING LOW LEVEL FLOW AS
CYCLOGENESIS TAKES PLACE ACROSS THE SOUTHERN GULF STATES. A STRONG
HYBRID/MILLER B DAMMING SCENARIO WILL EVOLVE...WITH WARM AIR
SPREADING PRECIP ACROSS THE COOL DOME LATER TUE NIGHT...BUT
ESPECIALLY WED AND WED NIGHT. INITIAL PRECIP COULD BE SNOW ACROSS
MUCH OF THE NORTH AND WEST AS THE COLUMN WILL BE LARGELY
SUBFREEZING...WITH RAIN ACROSS THE SOUTH. MODEL DIFFERENCES ARE
MINOR ENOUGH CONCLUDE THAT THE MILLER B SCENARIO CONTINUES TO
EVOLVE...AND WITH COLD AIR IN PLACE...A WIDE TRANSITION ZONE BETWEEN
RAIN AND SNOW IS POSSIBLE...EVEN LIKELY TO DEVELOP...ACROSS THE
PIEDMONT ON WEDNESDAY PER CLIMATOLOGY. AT THIS POINT WILL BE RAISING
POPS INTO THE LIKELY CATEGORY WITH RAIN OR SNOW AS PRIMARY WEATHER
TYPES AS DETAILS BECOME MORE CLEAR AND CONFIDENCE INCREASES IN
SUBSEQUENT MODEL RUNS. HIGHS WEDNESDAY WILL BE COOLER THAN
GUIDANCE...WITH THE NORTHWEST POSSIBLY NOT GETTING OUT OF THE MID
30S. MEANWHILE...THE SOUTHEAST COULD REACH 50. A COASTAL LOW IS
EXPECTED TO BECOME DOMINANT AND LIFT NORTH OF THE AREA WEDNESDAY
NIGHT...AND WITH THE LOSS OF THE DEEPER MOISTURE...THE NUCLEATION
ZONE COULD DE-SATURATE TO PRODUCE LIGHT FREEZING RAIN/FREEZING
DRIZZLE ACROSS THE NORTH AND WEST OVERNIGHT. LOWS WILL RANGE FROM 30
NORTHWEST TO 36 IN THE SOUTHEAST. ON THURSDAY...THERE WILL BE THE
POTENTIAL FOR LINGERING PRECIP...AND POSSIBLY SOME FREEZING
DRIZZLE...WITH HIGHER POPS NORTH AND WEST WHERE LOW LEVEL MOISTURE
WILL BE LOCKED IN PLACE BY THE NORTHERLY FLOW BEHIND THE DEPARTING
LOW. THURSDAYS HIGHS WILL BE MOSTLY IN THE 40S...REACHING THE LOW
40S LATE IN DAY (IF AT ALL) IN THE NORTHWEST.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 100 PM THURSDAY...
24-HR TAF PERIOD: VFR CONDITIONS WITH CEILINGS 12-18 KFT WILL
PREVAIL THROUGH 00Z THIS EVENING. A SHORTWAVE DISTURBANCE TRACKING
NORTHEAST THROUGH THE DEEP SOUTH THIS AFTERNOON WILL CROSS THE
CAROLINAS LATE THIS EVENING. A SHORT PERIOD (~3 HRS) OF MVFR
CEILINGS CANNOT BE RULED OUT IN THE 03-09Z TIME FRAME AT THE KFAY
TERMINAL...PERHAPS THE KRDU/KRWI TERMINALS AS WELL...AND HAVE
INCLUDED A TEMPO GROUP BETWEEN 04-08Z TO ACCOUNT FOR THIS
POSSIBILITY. NORTHERLY WINDS AT 5-10 KT WILL WEAKEN AND BECOME
LIGHT/VARIABLE THIS AFTERNOON...WITH LIGHT/VARIABLE WINDS PERSISTING
THROUGH THE DAY FRIDAY.
LOOKING AHEAD: VFR CONDITIONS AND LIGHT WINDS WILL PREVAIL ON
FRIDAY. SUB-VFR CONDITIONS AND PRECIPITATION WILL BE POSSIBLE DURING
THE DAY SATURDAY...LATE SUNDAY...AND AGAIN LATE MONDAY NIGHT THROUGH
TUESDAY AS A SERIES OF STORM SYSTEMS AFFECT THE CAROLINAS AND
VIRGINIA. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS/VINCENT
SHORT TERM...ELLIS
LONG TERM...MLM
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
102 PM EST THU FEB 6 2014
.SYNOPSIS...A WEAK UPPER LEVEL DISTURBANCE WILL CROSS THE REGION
THIS EVENING. POLAR HIGH PRESSURE WILL OTHERWISE BUILD EAST ACROSS
THE MIDDLE ATLANTIC STATES THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 100 PM THURSDAY...
REST OF TODAY: AS OF 17Z...BROKEN CLOUD COVER OVER THE CAROLINAS IS
ASSOCIATED WITH UPPER LEVEL MOISTURE ADVECTING INTO THE REGION VIA
SW FLOW ALOFT (DOWNSTREAM OF A SHORTWAVE TRACKING INTO LOUISIANA) IN
ADDITION TO A NARROW CORRIDOR OF MID-LEVEL (H7-H6) FRONTOGENESIS IN
VICINITY OF A LINE EXTENDING SW-NE FROM TROY-RALEIGH-TARBORO. 17Z
REGIONAL RADAR DATA INDICATED A NARROW BAND OF ECHOES (10-25 DBZ)
THAT CORRESPOND WELL WITH THE AFOREMENTIONED ZONE OF FGEN (MOST
PROMINENT BETWEEN 9000-15000 FT AGL). KRAX IS INDICATING FAINT
ECHOES (5-10 DBZ) AS LOW AS 4000 FT AGL OVER NORTHERN MOORE AND LEE
COUNTIES...IMPRESSIVE CONSIDERING THE DRY MID-LEVEL AIRMASS IN PLACE
AT 12Z THIS MORNING (12Z GSO/MHZ RAOBS). THE LATEST RAP GUIDANCE
INDICATES MID-LEVEL FGEN WANING ALONG/EAST OF HWY 1 BETWEEN 18-
21Z...AND THE BOUNDARY LAYER (SFC-4000 FT AGL) APPEARS DRY ENOUGH TO
PRECLUDE ANY CHANCE FOR PRECIP (ASIDE FROM VIRGA) THIS AFTERNOON.
PER OBSERVATION TRENDS AS OF 17-18Z...HIGH TEMPS APPEAR ON TRACK IN
THE LOWER/MID 40S...TEMPERED SLIGHTLY DUE TO DECREASED INSOLATION
ASSOCIATED WITH MID-LEVEL CLOUD COVER. -VINCENT
TONIGHT: THE SHORTWAVE TROUGH FROM THE RIO GRANDE WILL LIFT QUICKLY
NE ACROSS THE CENTRAL APPALACHIANS AND CAROLINAS THIS EVENING. NWP
GUIDANCE HAS CONTINUED TO TREND TOWARD MORE APPRECIABLE/DEEPER
SATURATION ALOFT...WHICH SHOULD SUPPORT WIDESPREAD VIRGA THIS
EVENING. HOWEVER...THE SUB-CLOUD LAYER WILL REMAIN DRY OWING TO
LITTLE OPPORTUNITY FOR MOISTURE RETURN IN THE WAKE OF THE FRONTAL
ZONE THAT PRESSED SOUTH OF OUR REGION DURING THE PAST 12 HOURS...SO
THE LOWERING MID LEVEL CEILINGS WILL HAVE A DIFFICULT TIME PRODUCING
MORE THAN SCATTERED SPRINKLES OR FLURRIES...PER FORECAST PARTIAL
THICKNESS VALUES THAT FALL IN THE WINTRY MIXTURE PORTION OF THE
NOMOGRAM. IF PRECIPITATION WERE TO FALL FOR A LONGER DURATION OR
WITH A GREATER INTENSITY...WET BULB THERMAL PROFILES IN THE BOUNDARY
LAYER WOULD SUPPORT SNOW...BUT AGAIN...NEITHER CRITERIA ARE EXPECTED
TO BE MET FOR THE REASONS OUTLINED ABOVE. WE WILL...HOWEVER...NEED
TO MONITOR THE MOISTURE RETURN SPREADING INLAND ALONG THE WESTERN
GULF COAST THIS MORNING...WHICH IF IT WERE TO LINK UP WITH THE
AFOREMENTIONED SHORTWAVE TROUGH AND ASSOCIATED MOISTURE...WOULD LEAD
TO A BETTER CHANCE OF LIGHT MEASURABLE PRECIPITATION. AT THIS
TIME...HOWEVER...THAT MOISTURE IS FORECAST TO BE SHUNTED EASTWARD
THROUGH CENTRAL GA/SC AND FAR SOUTHEASTERN NC...THEREBY LIMITING ANY
INTERACTION WITH THE APPROACHING LOWS IN THE UPPER 20S TO LOWER 30S.
FRIDAY: SOMEWHAT OF A REPEAT PERFORMANCE OF THE THE PREVIOUS 24
HOURS...AS YET A NEW SHORTWAVE TROUGH DEAMPLIFIES ON AN ALBEIT
SLIGHTLY MORE NORTHERLY TRACK FROM SW US...WHILE THE MODIFIED ARCTIC
HIGH CONTINUES TO RIDGE AROUND THE APPALACHIANS FROM THE WEST. NOT
AS COOL AS THE PARENT HIGH CONTINUES TO MODIFY...AND IS WEAKENED BY
A SURFACE TROUGH IN THE LEE OF THE APPALACHIANS. HIGHS IN THE UPPER
40S TO LOWER 50S. RIVEN LOWS MOSTLY IN THE LOWER 30S. -MWS
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 255 AM THURSDAY...
FOR FRIDAY NIGHT INTO SATURDAY MORNING A 1030 MB SURFACE HIGH WILL
MOVE ACROSS OHIO AND PENNSYLVANIA WITH A RIDGE EXTENDING DOWN THE
EASTERN SIDE OF THE APPALACHIANS. WHAT BEGINS AS AN INVERTED TROUGH
OFF OF THE COAST OF FLORIDA DEVELOPS INTO A CLOSED LOW OFF OF THE
SC/GA COAST BY 12Z SATURDAY. MODELS DIFFER IN THE TRACK AND TIMING
OF THE LOW WITH THE GFS SLOWER AND FURTHER OFFSHORE AND THE ECMWF
QUICKER AND CLOSER TO THE COAST. THE QUICKER/CLOSER ECMWF CARRIES
THE MOST CONSEQUENCES FOR SENSIBLE WEATHER FOR CENTRAL NC.
THICKNESSES AND WETBULB ZERO TEMPERATURES SUGGEST THAT PRECIPITATION
COULD START OUT AS RAIN OR SNOW WITH THE BEST CHANCES FOR SNOW
FURTHER TO THE NORTH AND WEST...BUT ALSO FURTHER AWAY FROM THE MAIN
MOISTURE SOURCE WHICH WOULD CUT DOWN ANY ACCUMULATION/IMPACTS OF ANY
SNOW THAT DOES FALL INITIALLY. THE SLOWER GFS KEEPS THINGS DRY UNTIL
TEMPERATURES AND THICKNESS INCREASE ENOUGH TO THWART THE THREAT OF
ANY WINTER P-TYPE ISSUES. AFTER 12Z ANY FALLING PRECIP WILL BE
LIQUID WITH THE WETTER ECMWF CARRYING CLOSER TO A HALF AN INCH OF
PRECIP IN THE EAST AND 2 TENTHS OF AN INCH OF THE TRIANGLE WITH LESS
TO THE NORTHWEST. THE GFS ONLY CARRIES 1 TO 2 TENTHS OF AN INCH FROM
THE TRIANGLE EASTWARD. CONFIDENCE IS STILL BELOW AVERAGE ON WHICH OF
THESE SCENARIOS WILL OCCUR BUT WPC PREFERENCES CONTINUE TO BE
WEIGHTED TOWARD THE ECMWF AND THUS WILL INCLUDE THE CHANCE FOR RAIN
OR SNOW IN THE NW THROUGH MID MORNING...AND TRANSITION TO RAIN
THEREAFTER. ALL PRECIPITATION SHOULD EXIT THE EASTERN CWA JUST AFTER
00Z SUNDAY. HIGHS SATURDAY WILL REMAIN COOLER WITH WEDGE IN PLACE
INITIALLY AND THEN OVERCAST THROUGH THE DAY...LOW 40S NW TO NEAR 50
SE. LOWS SATURDAY NIGHT IN THE MID 30S. WITH LOW LEVEL SATURATION
HOLDING THROUGH THE OVERNIGHT HOURS...EXPECT SOME AREAS OF FOG
THROUGH SUNDAY MORNING.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 255 AM THURSDAY...
SATURDAY NIGHT...WIDESPREAD LOW LEVEL MOISTURE WILL MAINTAIN
OVERCAST SKIES ALONG WITH PATCHES OF DRIZZLE/FOG AND SOME LIGHT
RAIN. MIN TEMPS MID-UPPER 30S...AROUND 40 SE.
SUNDAY AND MONDAY: AS THE LOW EXITS TO THE NORTHEAST ON
SUNDAY...RESIDUAL LOW LEVEL MOISTURE WILL KEEP FOG AND LOW STRATUS
IN PLACE UNTIL AFTER SUNRISE BEFORE LIFTING TO 850 MB OR SO. DESPITE
THIS LIFTING THE BROKEN/OVERCAST CEILINGS SHOULD REMAIN IN PLACE
THROUGH THE DAY ON SUNDAY KEEPING HIGH TEMPERATURES DOWN. EXPECT
HIGHS ON SUNDAY IN THE UPPER 40S TO LOWER 50S. WHILE THE LOWER
CLOUDS WILL DISSIPATE BY SUNDAY NIGHT...UPPER LEVEL OVERCAST WILL
TAKE OVER AS A SHORTWAVE IN THE NORTHERN STREAM APPROACHES FROM THE
NW. DIFFERENCES IN THE 500 MB FLOW SHOW A SLIGHTLY DEEPER TROUGH IN
THE GFS VS A MORE ZONAL TRACK IN THE ECMWF. THIS ALLOWS THE NORTHERN
STREAM SHORTWAVE TO DIP INTO THE NORTHERN HALF OF OUR CWA ON THE GFS
NEAR 00Z MONDAY WHILE THE ECMWF IS LATER WITH THIS FEATURE AND
FURTHER TO THE NORTH...KEEPING CENTRAL NC DRY. EVEN IF PRECIPITATION
DOES MAKE IT INTO THE NORTHERN CWA...REINFORCING COLD AIR DOES NOT
ARRIVE UNTIL LATER AND ALL PRECIP SHOULD FALL AS LIQUID. WILL
INCLUDE SLIGHT CHANCES IN THE NORTH FROM 21Z SUNDAY THROUGH 3Z
MONDAY. ACCUMULATIONS GENERALLY LESS THAN A TENTH OF AN INCH.
TEMPERATURES MONDAY IN THE MID 40S. THICKNESSES SUGGEST TEMPERATURES
IN THE LOW TO MID 20S TUESDAY MORNING BUT SOME LATE ARRIVING UPPER
LEVEL CLOUDINESS COULD BUMP THESE UP TO MID TO UPPER 20S.
TUESDAY AND WEDNESDAY: VERY LOW CONFIDENCE FORECAST FOR TUESDAY AND
WEDNESDAY WILL BE DEPENDENT UPON THE EVOLUTION OF THE MERGING OF
PACIFIC AND GULF MOISTURE OVER TEXAS DURING THE DAY ON TUESDAY. A
SURFACE HIGH CROSSING THE GREAT LAKES ON TUESDAY WILL SET UP YET
ANOTHER HYBRID CAD SCENARIO OVER CENTRAL NC. AS THE AFOREMENTIONED
TEXAS MOISTURE MOVES NORTHEASTWARD IN THE SOUTHERN STREAM FLOW...IT
WILL MERGE WITH A THIRD SOURCE OF MOISTURE COMING OUT OF THE
SOUTHWEST ATLANTIC. THERE ARE LARGE DISPARITIES IN MODEL TIMING AT
THIS POINT WITH THE MOST LIKELY SCENARIO BETWEEN THE TWO
DETERMINISTIC MODELS. THE GFS HAS THE BETTER ISENTROPIC LIFT
BEGINNING AFTER 18Z TUESDAY AND PRECIPITATION BEGINNING BEFORE 00Z
WEDNESDAY. THE EC HOLDS OFF UNTIL CLOSER TO 12Z WEDNESDAY SO WE CAN
EXPECT PRECIP TO BEGIN SOMEWHERE IN THE EARLY MORNING WEDNESDAY
TIMEFRAME. TRACK OF THE LOW IS ALSO A LOW CONFIDENCE FORECAST AT
THIS POINT AND IT IS TOO EARLY TO TELL IF WE WILL HAVE ANY WINTER P-
TYPE ISSUES AT THIS POINT BUT IT IS CERTAINLY POSSIBLE IN THE
FAVORED NORTHWEST PIEDMONT WEDNESDAY MORNING. WILL MOST LIKELY LEAVE
OUT OF THE FORECAST AT THIS POINT AND WAIT FOR BETTER CONFIDENCE IN
SUBSEQUENT MODEL RUNS. REGARDLESS WE CAN EXPECT A WET DAY ON
WEDNESDAY. TEMPERATURES WILL REMAIN BELOW NORMAL FOR THIS TIMEFRAME
WITH HIGHS IN THE THE LOW TO MID 40S AND LOWS IN THE UPPER 20S TO
MID 30S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 100 PM THURSDAY...
24-HR TAF PERIOD: VFR CONDITIONS WITH CEILINGS 12-18 KFT WILL
PREVAIL THROUGH 00Z THIS EVENING. A SHORTWAVE DISTURBANCE TRACKING
NORTHEAST THROUGH THE DEEP SOUTH THIS AFTERNOON WILL CROSS THE
CAROLINAS LATE THIS EVENING. A SHORT PERIOD (~3 HRS) OF MVFR
CEILINGS CANNOT BE RULED OUT IN THE 03-09Z TIME FRAME AT THE KFAY
TERMINAL...PERHAPS THE KRDU/KRWI TERMINALS AS WELL...AND HAVE
INCLUDED A TEMPO GROUP BETWEEN 04-08Z TO ACCOUNT FOR THIS
POSSIBILITY. NORTHERLY WINDS AT 5-10 KT WILL WEAKEN AND BECOME
LIGHT/VARIABLE THIS AFTERNOON...WITH LIGHT/VARIABLE WINDS PERSISTING
THROUGH THE DAY FRIDAY.
LOOKING AHEAD: VFR CONDITIONS AND LIGHT WINDS WILL PREVAIL ON
FRIDAY. SUB-VFR CONDITIONS AND PRECIPITATION WILL BE POSSIBLE DURING
THE DAY SATURDAY...LATE SUNDAY...AND AGAIN LATE MONDAY NIGHT THROUGH
TUESDAY AS A SERIES OF STORM SYSTEMS AFFECT THE CAROLINAS AND
VIRGINIA. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS/VINCENT
SHORT TERM...ELLIS
LONG TERM...ELLIS
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS BISMARCK ND
940 AM CST THU FEB 6 2014
.UPDATE...
ISSUED AT 925 AM CST THU FEB 6 2014
UPDATE FOR SKY COVER AND TEMPERATURE TRENDS...AND TO EXPAND AREA
OF FLURRIES INTO THE AFTERNOON SOUTHEAST. LOWERED TEMPS...MAINLY
SOUTHWEST DUE TO THE MUCH COLDER START TO THE DAY. LAYER RH PROGS
FROM THE 13KM RAP SUGGEST CLOUDS LINGERING MAINLY ACROSS THE EAST
INTO THIS AFTERNOON. WIND CHILL ADVISORY CONTINUES THROUGH THE MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST THU FEB 6 2014
DANGEROUS WIND CHILLS HIGHLIGHT THE SHORT TERM FORECAST.
FOR THIS MORNING...A BROAD DECK OF STRATUS WILL CONTINUE TO
OVERSPREAD WESTERN AND CENTRAL NORTH DAKOTA. THIS HAS HELPED TO
KEEP OVERNIGHT LOWS GENERALLY IN THE -5 TO -10 RANGE FOR MOST
LOCATIONS UNDER THE DECK. AS A RESULT...WIND CHILLS ARE LOW END
WIND CHILL ADVISORY CRITERIA IN THE -25 TO -30 RANGE FOR MOST
LOCATIONS. AS THE DECK IS ERODED FROM WEST TO EAST BY THE LATE
MORNING AND THROUGH THE AFTERNOON WITH INCREASING WESTERLY WINDS
...INSOLATION SHOULD ALLOW FOR HIGHS OF 5 TO 10 ABOVE. THIS WOULD
RESULT IN WIND CHILLS WARMING ABOVE ADVISORY CRITERIA ON SCHEDULE
BY 18 UTC. LIKE YESTERDAY...DID ADD A MENTION OF FLURRIES UNDER
THE STRATUS.
FOR TONIGHT...A SURFACE RIDGE AXIS WILL BE IN PLACE ACROSS THE
DAKOTAS...WITH CLEAR SKIES. THE ONE LIMIT TO OVERNIGHT COOLING WILL
BE MIXING ON THE ORDER OF 10-15 KTS. THUS TRENDED TOWARDS THE
WARMER EDGE OF GUIDANCE...THE CONSENSUS OF THE 00 UTC
DETERMINISTIC MODELS...FOR LOWS OVERNIGHT GENERALLY IN THE -5 TO
-10 RANGE. WHEN COMBINED WITH WINDS...SOME LOCATIONS HAVE WIND
CHILLS IN THE -25 TO -30 RANGE. WILL ALLOW FURTHER SHIFTS TO
EVALUATE IF A WIND CHILL ADVISORY WILL BE NEEDED FOR TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 352 AM CST THU FEB 6 2014
NO SIGNIFICANT CHANGES TO THIS TIME PERIOD WITH COLD
AND MOSTLY DRY WEATHER CONTINUING INTO NEXT WEEK BEFORE TEMPERATURES
BEGIN TO MODERATE AND LOW CHANCES OF PRECIP RETURN.
MODELS ARE IN GOOD AGREEMENT WITH 500MB FLOW INITIALLY SHOWING SPLIT
FLOW IN PLACE. HUDSON BAY LOW SHIFTS EASTWARD DURING THE WEEKEND
WITH BROAD TROUGH OVER EASTERN NORTH AMERICA AND RIDGE OVER THE WEST
LEAVING NORTHERN PLAINS IN NORTHWEST FLOW ALOFT INTO EARLY NEXT
WEEK. BOTH GFS/ECMWF SHOW SHORTWAVE IN NW FLOW CROSSING OUR REGION
AROUND TUESDAY AND RELATIVELY WEAK SURFACE LOW...THOUGH SOME TIMING
AND LOCATION DIFFERENCES EXIST. CONTINUE TO CARRY SOME LOW POPS FOR
THIS TIME PERIOD.
WITH REGARD TO COLD WEATHER...WIND CHILL VALUES DROP TO -25 TO -30
RANGE FRIDAY NIGHT MAINLY ACROSS THE NORTH AND INTO NORTHERN JAMES
RIVER VALLEY. WIND CHILLS ARE FORECAST A LITTLE COLDER ON SATURDAY
NIGHT RANGING FROM -30 TO -35 DEGREES MAINLY EAST AND NORTH OF THE
MISSOURI RIVER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 925 AM CST THU FEB 6 2014
MVFR CEILINGS AND A FEW LIGHT SNOW SHOWERS WILL CONTINUE THROUGH
THE MORNING HOURS. CLEARING TREND EXPECTED FROM WEST TO EAST
ACROSS THE STATE THIS AFTERNOON AND EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 1 PM CST /NOON MST/ THIS AFTERNOON FOR
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM...AYD
LONG TERM...JNS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1144 PM CST WED FEB 5 2014
.UPDATE...
ISSUED AT 938 PM CST WED FEB 5 2014
IT APPEARS THAT MOST AREAS ACROSS THE FA HAVE AT LEAST SOME
CLEARING...ALTHOUGH MID-HIGH CLOUDS REMAIN SCT-BKN AT TIMES. THE
LOW CLOUDS UPSTREAM IN MANITOBA BREAK APART AS THEY APPROACH THE
REGION...WHICH THE RAP INDICATES. WILL CONTINUE WITH THE TREND OF
LOWERING SKY THROUGH THE NIGHT (ALTHOUGH WITH LOWER THAN NORMAL
CONFIDENCE). MODELS INDICATE 10-15 KNOT WINDS WEST OF THE
VALLEY...WITH MUCH LIGHTER WINDS EAST OF THE VALLEY. THUS...MIN
TEMPS WILL BE WARMER WEST OF THE VALLEY...WHICH THE CURRENT
FORECAST INDICATES. WIND CHILL ADVISORY IN GOOD SHAPE.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 255 PM CST WED FEB 5 2014
THE CHALLENGE FOR THE FORECAST IS TEMPS AND WIND CHILLS AS CLOUD
TRENDS CONTINUE TO BE DIFFICULT TO FORECAST.
SHORT WAVE EMBEDDED IN 500MB TROUGH CENTERED OVER THE FA IS
CONTINUING TO BRING CLOUDS TO THE CWFA. ENERGY WILL SLOWLY
PINWHEEL EAST SOUTHEAST AND WEAKEN TONIGHT. HOW MUCH CLEARING WILL
OCCUR AS THE SYSTEM EXISTS IS UNCERTAIN AS UPSTREAM STRATUS DECK
IN SASKATCHEWAN MAY LIMIT TEMPERATURE FROM FALLING TO DRAMATICALLY
OVERNIGHT. CLOUD DECK DECREASING IN COVERAGE DEPICTED IN MODEL
SOLUTIONS OVERNIGHT BUT UNCERTAINTY REMAINS. NONETHELESS TEMPS
AND WIND TO COMBINE ONCE AGAIN FOR APPARENT TEMPS TO RANGE FROM 25
TO 40 BELOW. AS A RESULT THE ALMOST DAILY WIND CHILL ADVISORY HAS
BEEN ISSUED FOR THIS EVENING THRU 18Z THURSDAY.
SLIGHTLY HIGHER MAX TEMPS EXPECTED TOMORROW WITH 925MB TEMPS A
BIT WARMER AND WARMING WESTERLY SFC WINDS DEVELOP AS PRESSURE
GRADIENT TIGHTENS ACROSS THE REGION BETWEEN THE SFC HIGH OVER THE
WESTERN DAKOTAS AND THE HUDSON BAY STACKED LOW PRESSURE SYSTEM.
WESTERLY WINDS CONTINUE THURSDAY NIGHT WITH SOME CLOUD COVER
KEEPING TEMPS IN THE 5 TO 10 BELOW RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 255 PM CST WED FEB 5 2014
FRIDAY AND SATURDAY MORE OF THE SAME WITH 500MB NW FLOW ALOFT AND
THE NEXT RE-ENFORCING SHOT OF COLD AIR EXPECTED SATURDAY MORNING.
TEMPS CONTINUE TO BE BELOW NORMAL WITH HIGHS IN THE SINGLE DIGITS
AND LOW 5 TO 15 BELOW.
MODELS REMAIN IN GOOD AGREEMENT IN SHOWING HIGH PRESSURE SETTLING
OVER THE AREA WITH LIGHT WINDS SUNDAY INTO MONDAY. TEMPS WILL
REMAIN WELL BELOW NORMAL. 500 MB PATTERN FLATTENS A BIT BY NEXT
WED WITH A PACIFIC LOW MOVING EAST NEAR THE INTL BORDER AND SHOULD
SPREAD A CHANCE FOR SOME LIGHT SNOWS TUES NIGHT-WED BUT MOST OF
THE ACTION LOOKS NORTH OF THE LOW IN CANADA. 12Z ECMWF IS A BIT
WARMER SOUTH OF THE LOW THAN GFS...BUT OVERALL AN UPWARD TREND IN
TEMPS SEEN BY WED WITH TEENS FOR HIGHS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1144 PM CST WED FEB 5 2014
CIGS HAVE BEEN GRADUALLY CLEARING OR RISING AS EXPECTED. THERE IS
AN AREA OF MVFR CIGS THAT CONTINUES TO APPROACH THE REGION.
HOWEVER...THESE CIGS ARE DISSIPATING AS THEY ENTER...AND THE RAP
GUIDANCE INDICATES THIS TREND WILL CONTINUE. THERE MAY BE BRIEF
MOMENTS OF MVFR CIGS THIS MORNING...BUT NOTHING LONG TERM IS
EXPECTED.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR NDZ006>008-
014>016-024-026>030-038-039-049-052>054.
MN...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR MNZ001>009-
013>017-022>024-027>032-040.
&&
$$
UPDATE...TG
SHORT TERM...JK
LONG TERM...JK/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1259 AM EST THU FEB 6 2014
.SYNOPSIS...
COLDER WITH LIGHT UPSLOPE SNOW SHOWERS TONIGHT IN THE WAKE OF LOW
PRESSURE. HIGH PRESSURE FOR THE END OF THE WEEK. WEAK MID/UPPER
LEVEL DISTURBANCES OVER THE WEEKEND IN BOARD TROF.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATED POPS BLENDING IN THE HIGH RESOLUTION MODEL HRRR QPF AS IT
LOOKS WELL INITIALIZED BY RADAR. FINE LINES OF SNOW SHOWERS ARE
EVIDENT ON RADAR IMAGES PERPENDICULAR TO THE EASTERN MOUNTAINS.
EXPECT AT LEAST ONE INCH OR TWO OVER THE HIGHER TERRAIN...AND JUST
A COATING OF SNOW ACROSS CENTRAL LOWER ELEVATIONS. PCPN SHOULD
DIMINISH IN COVERAGE BY MIDNIGHT.
STILL WATER LEVELS FROM LITTLE SANDY RIVER AT GRAYSON CONTINUES
ABOVE FLOOD STATE BUT HYDROGRAPH SHOWS IT HAS CRESTED. WITH THE
BULK OF PCPN ENDED...AND NOT SIGNIFICANT PCPN EXPECTED...BELIEVE
WATER LEVELS OR MOST RIVER SHOULD BE RUNNING HIGH...CRESTING OR
LOWERING. EXCEPTIONS WILL BE SMALL STREAMS WITH DEBRIS AND/OR ICE
JAMS THAT COULD PRODUCE MINOR FLOODING PROBLEMS.
ANY LINGERING LIGHT SNOW SHOWERS WILL TAPER OFF ACROSS THE
MOUNTAINS BY LATE THURSDAY MORNING. WILL STILL BE PLENTY OF LOW
CLOUD COVER LINGERING THROUGH THURSDAY...AS MOISTURE REMAINS
TRAPPED BENEATH LOW LEVEL INVERSION...BUT WILL START TO SEE SOME
LIFTING/PARTIAL CLEARING BY THURSDAY AFTERNOON. HOWEVER...WITH
THAT SAID...WILL ALSO SEE AN INCREASE IN MID AND HIGH CLOUDS FROM
SYSTEM TO THE SOUTH...SO OVERALL...RELATIVELY CLOUDY CONDITIONS
WILL PERSIST.
MUCH COLDER AIR WILL MOVE INTO THE REGION TONIGHT...WITH 850MB
TEMPS FALLING TO AROUND -14C. DID LOWER OVERNIGHT LOW TEMPS
SLIGHTLY FROM PREVIOUS FORECAST...BUT DIDNT WANT TO GO TOO COLD
WITH PERSISTENT CLOUD COVER.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
SHORT TERM PERIOD BEGINS QUIETLY WITH WEAKLY-AMPLIFIED SW FLOW
ALOFT. AT THE SURFACE...WEAK WESTERLY FLOW WILL CONTINUE OVERNIGHT
THU NIGHT WITH HIGH PRESSURE PUSHING INTO THE AREA FROM THE
WEST...PROGGED TO BE CENTERED OVER THE MID-MISS VALLEY BY 12Z FRI. A
BIT OF A TOUGH CALL ON OVERNIGHT MINS BUT A WEAK RIPPLE IN THE FLOW
PUSHING ACROSS OVERNIGHT WILL KEEP LOW CLOUDS IN PLACE FOR MUCH OF
THE AREA...AND AS SUCH WILL SIDE ON THE WARMER SIDE OF GUIDANCE.
WILL SEE MINS GENERALLY MID/UPPER TEENS TO LOW 20S WEST VIRGINIA
LOWLANDS...WHILE SE OHIO DROPS INTO THE UPPER SINGLE DIGITS TO LOW
TEENS GENERALLY. SOME QUESTIONS WITH REGARD TO FRIDAY SKY COVER WITH
A DECENT AMOUNT OF LOW LEVEL MOISTURE TRAPPED...ESPECIALLY EAST OF
THE OHIO AS USUAL. COLD ADVECTION CEASES DURING THE AFTERNOON
HOWEVER AND WITH THAT...WILL KEEP A MOSTLY CLOUDY SKY FOR MOST THEN
ALLOW FOR SOME PARTLY CLOUDY SKIES LATER IN THE AFTERNOON.
UNFORTUNATELY...HAD TO LOWER MAX TEMPS FRIDAY BY A GOOD 3F-5F FOR
MOST LOCATIONS PER LATEST NWP OUTPUT AND MOS GUIDE. PROGGED 925MB
TEMPS OF -7C TO -8C ALONG THE I-64 CORRIDOR WOULD ONLY SUPPORT SFC
TEMPS STRUGGLING TO BREAK THE FREEZING MARK WITH FULL SUN AND
MIXING. TEMPS ACROSS SE OHIO MEANWHILE WILL ONLY REACH THE LOW/MID
20S WITH 925MB TEMPS BTWN -11C AND -13C AND A RESIDUAL SNOW
COVER.
BY FRIDAY NIGHT THROUGH SATURDAY DIFFS IN VARIOUS NWP OUTPUT
CONTINUE WITH THE SYSTEM PROGGED FOR THE WEEKEND. OPERATIONAL MODELS
ARE COMING INTO BETTER AGREEMENT WITH REGARD TO THE SYNOPTIC SCALE
FEATURES...WITH OUR FORECAST AREA GENERALLY BEING SANDWICHED BTWN
THE SFC LOW WELL TO OUR SOUTHEAST...AND THE NEXT UPPER TROUGH AND
ASSOC SFC LOW PROGRESSING EASTWARD OVER THE CENTRAL AND UPPER
MIDWEST. ANOTHER QUICK-MOVING S/W TROUGH IN THE FLOW ALOFT AND ITS
MOISTURE FIELD PROVIDES THE MAIN DIFFS WITH POTENTIAL PRECIP FOR
SAT...WITH THE LATEST NAM12 SHOWING FAIRLY MEAGER LLVL MOISTURE AND
LATEST OP GFS MORE BULLISH WITH ITS HANDLING OF THE MOISTURE. IN
ESSENCE...WILL BRING AN AREA OF SOMEWHAT HIGHER POPS ACROSS THE
SOUTHERN/MOUNTAINS ZONES BTWN 12Z-18Z SAT...THEN WILL TRANSITION THE
HIGHER POPS TOWARDS THE NORTH AND NORTHWEST DURING THE AFTERNOON AS
THE MORNING SYSTEM PULLS AWAY WITH THE SYSTEM TO THE WEST GETTING A
LITTLE CLOSER. LOWERED MAX TEMPS JUST A BIT BUT STILL EXPECT THE
UPPER 30S TO NEAR 40 POSSIBLE FROM THE I-64 CORRIDOR AND LOWER 40S
FOR THE SOUTHERN COALFIELDS. WITH FAIRLY DRY AIR AT THE SFC WITH
DECENT DEWPOINT DEPRESSIONS EVEN SAT AFTERNOON...MAINTAINED MOSTLY
SNOW OR AT LEAST A RAIN/SNOW MIX FOR MOST LOCATIONS EXCEPT THE
COALFIELDS AS ANY PRECIP WHICH COULD BRIEFLY BEGIN AS RAIN FURTHER
NORTH WOULD QUICKLY TRANSITION TO SNOW. NOT EXPECTING MUCH IN THE
WAY OF ACCUMULATION HOWEVER BUT DID INSERT UP TO A HALF-INCH ACROSS
THE FAR NORTHWEST ZONES OF SE OHIO AND THE EAST MOUNTAINS BY END OF
THE PERIOD.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CONSIDERING THE WET GROUND AND SWOLLEN WATERWAYS...THANKFULLY...WE
CONTINUED TO FORECAST NO MAJOR STORM FOR THIS WEEKEND.
ALSO...NO COLD WAVES...BUT BELOW NORMAL TEMPERATURES TRYING TO
MODERATE TOWARD SEASONABLE.
TRIED TO HOLD ONTO POPS A BIT HIGHER THAN GUIDANCE FOR THE
POSSIBILITY OF SOME LIGHT SNOW IN THE BOARD 500 MB TROF SATURDAY
NIGHT INTO SUNDAY. WE CONTINUE TO FORECAST NO MAJOR STORM THIS
WEEKEND.
COLDER AIR STILL FORECAST TO ADVECT IN SUNDAY NIGHT INTO MONDAY.
AGAIN HELD ONTO HIGHER POPS FOR LINGERING SNOW SHOWERS ESPECIALLY IN
WEST VIRGINIA SUNDAY NIGHT. THERE MAY EVEN BE SOME MID LEVEL
DISTURBANCES STILL CROSSING SUNDAY NIGHT IN THAT BROAD 500 MB TROF.
MAINLY DRY MONDAY. TRIED TO STREAK EAST...SOME CHANCE POPS MONDAY
NIGHT IN THE FAST ZONAL FLOW.
WENT HIGHER POPS THAN WPC GUIDANCE...FOR TUESDAY INTO
WEDNESDAY...WITH LIKELY POPS FIRST INTRODUCED ACROSS SOUTHERN
COUNTIES. 12Z GFS FURTHER SOUTH COMPARED TO ECMWF. NORTHERN
SOLUTION COULD BE SOME SNOW TO RAIN.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
EXPECT A SLOW IMPROVEMENT TO THE AVIATION CONDITIONS TONIGHT WITH
THE LIGHT SNOW ENDING. MVFR CEILINGS BECOME VFR GENERALLY AFTER
18Z THURSDAY...GIVE OR TAKE A COUPLE OF HOURS DEPENDING ON THE
TERMINAL. VFR EXPECTED INTO THURSDAY NIGHT WITH A DRY FORECAST IN
PLACE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: CEILINGS MAY LIFT TO VFR SOONER THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 02/06/14
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY M M M M L L L M H H H H
HTS CONSISTENCY H H H M M H H H H H H H
BKW CONSISTENCY M M M M M L L L H H H H
EKN CONSISTENCY M M M M M M M L L L L H
PKB CONSISTENCY H L H H H H H H H M H H
CKB CONSISTENCY M M M M M M M L L L M H
AFTER 06Z FRIDAY...
IFR POSSIBLE SATURDAY AND SUNDAY IN RAIN AND SNOW SHOWERS.
&&
.EQUIPMENT...
PKB ASOS HAS BEEN EXPERIENCING MALFUNCTIONS...RESULTING IN SOME
MISSING OR INCOMPLETE OBSERVATIONS. TECHNICIANS ARE AWARE OF THE
PROBLEM AND PARTS ARE BEING ACQUIRED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/50/SL
NEAR TERM...ARJ/SL
SHORT TERM...50
LONG TERM...KTB
AVIATION...26
EQUIPMENT...
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
400 PM PST FRI FEB 7 2014
UPDATED AVIATION DISCUSSION
.SYNOPSIS...THE SECOND SYSTEM IN A ONE-TWO-THREE PUNCH OF WINTRY
WEATHER FOR NORTHWEST OREGON IS BRINGING WIDESPREAD SNOW TO THE AREA
THROUGH THIS EVENING. SEVERAL INCHES OF SNOW
ARE LIKELY FOR MOST OF OUR NORTHWEST OREGON ZONES BY SATURDAY
MORNING...EVENTUALLY CHANGING TO SLEET AND FREEZING RAIN FROM THE
SOUTH. SOUTHWEST WASHINGTON WILL BE ON THE NORTHERN FRINGE OF THE
HEAVIER PRECIPITATION. THE THIRD SYSTEM WILL BRING MORE WINTRY
WEATHER TO OUR AREA LATER SATURDAY INTO SUNDAY...BUT THERE IS STILL A
BIT OF UNCERTAINTY IN HOW FAR NORTH THIS SYSTEMS IMPACTS WILL REACH.
EXPECT SNOW TO DOMINATE THE NORTH WITH A MIX POSSIBLE FARTHER SOUTH.
OVERALL A VERY COMPLEX WINTER WEATHER SITUATION UNFOLDING OVER
SOUTHWEST WASHINGTON AND NORTHWEST OREGON THROUGH SUNDAY. NEXT WEEK
THERE WILL BE A TURN TOWARD MORE TYPICAL WEATHER FOR THE REGION WITH
MILDER PACIFIC FRONTAL SYSTEMS BRINGING PERIODS OF RAIN.
&&
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...WIDESPREAD SNOW ACROSS
THE AREA THIS AFTERNOON...THOUGH MUCH LIGHTER WINDS TODAY EXCEPT IN
THE GORGE AND TOWARD EAST COUNTY. THE SURFACE LOW WELL OFFSHORE OF
THE COLUMBIA RIVER HAS BECOME STATIONARY AS AN OCCLUDING
FRONT/SURFACE LOW IS BECOMING MORE DOMINANT AND QUITE IMPRESSIVE
WITH CONVECTIVE LOOKING ELEMENTS EMBEDDED. THIS IS IN RESPONSE TO A
STRENGTHENING UPPER LEVEL JET POINTED AT THE SOUTH OREGON COAST.
ALONG THE WARM FRONTAL BOUNDARY A SHEARED OUT THOUGH SOMEWHAT POTENT
VORT MAX IS RIDING. THIS WAVE COUPLED WITH MOIST WARM ADVECTION IS
EXPECTED TO REINVIGORATE PRECIPITATION THIS EVENING. NOT LIKE THE
CURRENT PRECIPITATION RATES ARE NO SLOUCH. THE CURRENT SNOW MOVING
NORTH THROUGH THE VALLEY IS MORE WARM ADVECTION INDUCED...WITH SOME
MID LEVEL FRONTOGENESIS AIDING IN SOME LOCAL
ENHANCEMENT...ESPECIALLY AS THE SNOW SPREADS NORTH.
PRECIPITATION TYPE IS OUR MAIN CONCERN WITH THIS SECOND SYSTEM...NOT
TO IGNORE THE WIDESPREAD SNOW THAT WILL CONTINUE THROUGH THIS
EVENING. FORTUNATELY FOR MOST AREAS SNOW WILL DOMINATE. THIS
INCLUDES EVERYWHERE FROM SALEM NORTHWARD EXCEPT FOR THE IMMEDIATE
COAST...WHERE SIMILAR SNOW TOTALS OR SLIGHTLY LESS ARE EXPECTED DUE
TO NOW REAL BANDING SETTING UP JUST YET. THE SITUATION ALONG THE
COAST IS A BIT COMPLICATED. THE CENTRAL COAST TO THE SOUTH OF
NEWPORT IS ABOVE FREEZING...SO RAIN WILL NOW DOMINATE FROM THIS
POINT FORWARD. WITH THE WARMER AIR FROM THE SOUTH NUDGING
NORTH...SOME FREEZING RAIN SLEET AND RAIN WILL MIX IN FROM NEWPORT
NORTH. THIS IS ALSO THE CASE IN CENTRAL COAST RANGE WHERE SILETZ HAS
HAD MOSTLY SNOW AND NOW A MIX OF SNOW AND FREEZING RAIN AFTER SOME
FZRA EARLIER TODAY.THERE ARE SOME SELECT LOCATIONS ALONG THE NORTH
COAST WHERE RAIN MAY ALSO BE THE CASE...BUT WITH PRECIPITATION RATES
PICKING UP...SNOW WILL CONTINUE IN SPOTS. THE BIG HEADACHE IS AS WE
CONTINUE TO MONITOR RAWS STATIONS IN THE CENTRAL COAST RANGE THAT
LIE ANYWHERE FROM 1500-2000 FT ABOVE THE GROUND...WE TRULY SEE THE
BATTLE BETWEEN THE COLDER DENSE AIR THAT HAS BEEN IN PLACE AND THE
WARMER AIR TO THE SOUTH. HIGH POINT AND GOODWIN PEAK TO THE
SOUTHWEST OF EUGENE ARE 32-34 AND HAVE BEEN WARMER WHICH MAY ALSO BE
DUE TO THE PRECIP COOLING THINGS OFF...WITH WILKINSON AND VILLAGE
CREEK TO THE NORTHWEST OF EUGENE AT 30...WHICH IS UP A FEW DEGREES.
THE RAP WOULD SUGGEST THAT SNOW WILL REMAIN THE DOMINANT P-TYPE
THROUGH THE AFTERNOON...THEN AS THE SURFACE LOW TAKES AIM...ALL
GUIDANCE...INCLUDING THE RAP AND ECMWF BRING IN A WARM NOSE THAT
SHOULD...AT LEAST AT TIMES MIX FREEZING RAIN OR SLEET IN. THE
CONCERN IS THAT OUR HEAVIEST PRECIPITATION IS STILL TO COME THIS
EVENING WHEN THE WARM NOSE IS SUGGESTED TO COME IN. THIS WILL MAKE
ALL THE DIFFERENCE BETWEEN CONTINUED MODERATE TO HEAVY SNOW...OR
SIGNIFICANT ICE ACCUMULATIONS. FEELING WITH A LOW TRACK TO THE SOUTH
THAT SNOW WILL DOMINATE...THOUGH IGNORING ALL GUIDANCE IS
CHALLENGING SO WILL NEED TO KEEP THE FREEZING RAIN THREAT MENTIONED.
WE ARE HEARING OF SOME FZRA IN THE CASCADE FOOTHILLS.
THE SURFACE LOW PUSHES INTO THE SOUTHERN OREGON COAST AND THEN PASSES
BY TO THE SOUTH OF EUGENE AND WASHES OUT SOME. AGAIN BECAUSE OF
THIS...THE COLD AIR FARTHER NORTH DOES NOT SCOUR OUT. WHILE AREAS
NORTH GET ANOTHER LULL AND LIGHTER PRECIPITATION RATES THROUGH EARLY
AFTERNOON....THERE IS STILL A STRONG JET POINTED AT THE
AREA THAT WILL KEEP THINGS GOING IN THE SOUTHERN TIER AND INTO THE
CASCADES. THE SOUTHERN TIER WILL AGAIN BE A QUESTION MARK DUE TO THE
LOW PASSING BY TO THE SOUTH WHICH MAY ALLOW A TRANSITION BACK TO
SNOW...OR JUST CONTINUE SNOW IF THE FREEZING RAIN DOESN`T
MATERIALIZE.
ON SATURDAY AFTERNOON ANOTHER LOW RIDES A SIMILAR OR
SLIGHTLY FARTHER NORTH TRACK. THE GFS AND ECMWF ALLOW THE WARM NOSE
TO GET UP TO NEAR SALEM. THE NAM DOES THE SAME EVENTUALLY BRINGING UP
TO AURORA/WILSONVILLE AREA. MEANWHILE SOUNDINGS AND THE GENERAL
SYNOPTIC PATTERN SUGGEST ALL POINTS NORTH AND THROUGH THE COLUMBIA
RIVER GORGE REMAIN SNOW THROUGH THE NIGHT THIS LOW DOES THE SAME
THING ALL THE OTHERS DO...PASS BY SOUTH AND THEN WASH OUT. /KMD
.LONG TERM...
SUNDAY THROUGH MONDAY...SUNDAY WILL LIKELY BE THE TRANSITION DAY OUT
OF THE SNOW TO RAIN. HOWEVER THERE WILL BE A PERIOD OF FREEZING RAIN
AND SLEET. THERE ARE STILL DIFFERENCES IN MODEL SOLUTIONS FOR THIS
TIME PERIOD...BUT TYPICALLY MODELS ARE TOO FAST IN MODERATING THE
AND HAVE TAKEN THIS INTO ACCOUNT. THE NORTH WILLAMETTE VALLEY AND
ESPECIALLY AREAS NEAR THE COLUMBIA RIVER GORGE WILL BE HAVE A WINTRY
MIX THROUGH LATE SUN...AND POSSIBLY A LITTLE LONGER. THE COLUMBIA
RIVER GORGE WILL LIKELY CONTINUE UNDER THE THREAT OF FREEZING RAIN
OR SLEET THROUGH MONDAY. ICE ACCUMULATION AMOUNTS WILL PROBABLY BE
IN THE 0.1 TO 0.2 INCH WITH THE HIGHER AMOUNTS IN THE NORTH
WILLAMETTE VALLEY AND GORGE. WILL HAVE TO WATCH HOW THE MODELS
HANDLE THIS CHANGING SITUATION.
MONDAY NIGHT NIGHT THROUGH FRIDAY...THE PACNW IS UNDER THE
STORM TRACK FOR THE WEEK AHEAD. BROAD LOW PRESSURE WILL SET UP OVER
THE GULF OF ALASKA WITH A BROAD RIDGE CENTERED JUST OFF THE BAJA
CALIFORNIA COAST. THIS WILL ALLOW A SERIES OF SHORT WAVES TO
PROGRESS ALONG JET STREAM AND BRING MORE FREQUENT PERIODS OF RAIN
AND MOUNTAIN SNOW AND FEWER DRY PERIODS. GENERALLY SPEAKING...WILL
SEE SNOW LEVELS FLUCTUATE BETWEEN 3000 FEET AND 5500 FEET DEPENDING
ON WHEN THE PASSING SHORT WAVES PUSH LEADING WARMER AIR SLIGHTLY
FURTHER NORTH. OVERALL...THIS APPEARS TO BE A GOOD PATTERN FOR
PRODUCING SNOW PACKS HIGHER IN THE CASCADES AS OVERNIGHT
TEMPERATURES WILL LARGELY STAY BELOW FREEZING. MODELS ARE IN DECENT
AGREEMENT WITH OVERALL TIMING OF INDIVIDUAL WAVES. PRECIP NOW
APPEARS TO BE FOCUSED ON TUESDAY/ TUESDAY EVENING...AND THEN
THURSDAY HEADING INTO THURSDAY NIGHT. MODELED QPF AMOUNTS VARY...NOT
SURPRISINGLY...BETWEEN THE MEDIUM RANGE MODELS AND THE INDIVIDUAL
WAVES...BUT IT DOES APPEAR THE PACNW WILL BE IN THE CROSS HAIRS OF
THE PACIFIC MOISTURE FEED. THUS DO NOT FEEL OVERLY COMFORTABLE
REGARDING THE NATURE OF ANY ONE SPECIFIC SYSTEM. FORTUNATELY...THERE
DO APPEAR TO BE AROUND 12 HOUR BREAKS BETWEEN SYSTEMS.THERE IS ONE
FEATURE THE ECMWF IS TRENDING TOWARD...IS A STRONG WAVE RIDING ON A
FRONT THAT MAY BRING QUITE A BIT MORE RAIN AND WIND THAN IN THE
CURRENT FORECAST FOR THE TUE NIGHT WED TIME PERIOD. HAVE TRENDED
FORECAST TOWARD THAT SOLUTION FOR NOW./MH
&&
.AVIATION...00Z TAF PACKAGE. TODAY`S SNOW BAND HAS REACHED THE KPDX
METRO REGION ABOUT A COUPLE HOURS AGO AND SHOULD START AT KAST ANY
MOMENT. PRECIP HAS LARGELY REMAINED SNOW EVEN AT KEUG WHILE THE
COAST IS STARTING TO SEE WARMER AIR INFLUENCE AND BRINGING
INTERMIXED POCKETS OF SNOW AND FREEZING RAIN. A SMALL SCALE SURFACE
IS ABOUT TO COME ASHORE BUT FURTHER SOUTH THAN PREVIOUSLY EXPECTED.
THIS HAS KEPT THE BULK OF THE WARM NOSE FROM AFFECTING KEUG. STILL
FEEL LIKE IT WILL START AT KEUG WITHIN THE NEXT COUPLE HOURS AS THE
LOW CROSSES THE COAST RANGE IN RELATIVELY CLOSE PROXIMITY WITH A
WARM NOSE SWINGING OVER THE FIELD. BEGINNING TO LOSE CONFIDENCE,
HOWEVER, AS TO IF THE FZRA WILL PERSIST OR GIVE WAY BACK TO OVERALL
SNOW LATER TONIGHT. WILL HOLD ON SOME FORM OF FZRA MIX UNTIL
STRONGER ONSHORE FLOW CAN PUSH OVER THE SOUTH AND CENTRAL VALLEY.
THIS ALSO RESULT IN A LATER START FOR FZRA AT KSLE AND POINTS NORTH.
STILL LOOKS LIKE MOST OF SATURDAY DAYLIGHT HOURS WILL INVOLVE FZRA
AT KSLE AND PROBABLY WAITING UNTIL AFTER 09/00Z BEFORE AFFECTING
KPDX, KHIO, KAST, AND LATEST AT KTTD.
KPDX AND APPROACHES...WE ARE REACHING THE TIME WHERE PEAK SNOW WHERE
PERIODS OF HEAVY ACCUMULATION WILL AFFECT THE FIELD. ALSO EXPECT BLSN
TO OBSCURE NEAR SURFACE VSBY FOR THE NEXT SEVERAL HOURS AS EASTERLY
WINDS OUT OF THE GORGE ACCELERATE SOME. CONTINUE TO EXPECT AROUND 3
INCHES OF TOTAL ACCUMULATION BY LATER EVENING AND PERHAPS ANOTHER
INCH OVERNIGHT. LOOKS LIKE SNOW WILL EVENTUALLY BECOME MORE SHOWERY.
CURRENT THOUGHTS BRING FIRST FZRA POSSIBILITY TO KPDX AROUND 09/03Z
BUT EVEN THIS MAY BE TOO SOON. /JBONK
&&
.MARINE...BROAD AREA OF LOW PRES OVER NE PAC...WITH HIGH PRES WELL
INLAND. OFFSHORE WINDS HAVE GRADUALLY INCREASED OVER THE LAST FEW
HOURS. REALITY IS OUT-PERFORMING THE MODELS AS A SMALL SURFACE LOW
WILL MOVE ASHORE NEAR NORTH BEND OREGON. THIS IS DRAGGING THE
EASTERLY GRADIENT FURTHER DOWN THE COAST AND BRINGING SMALL CRAFT
ADVISORY LEVEL WINDS TO THE CENTRAL COAST GAPS. AS SUCH HAVE ADDED
THE REMAINING COASTAL ZONES TO THE ADVISORY. THE CENTRAL COAST
ZONES MAY ACTUALLY EASE UP CLOSER TO MIDNIGHT RATHER THAN 4 AM.
ADDITIONALLY...FREEZING RAIN IS OCCURRING NEAR NEWPORT AND WILL
PROGRESS NORTHWARD UP THE COAST THROUGH THE EVENING...PERHAPS
REACHING AS FAR AS KAST BUT MORE LIKELY SEASIDE AND SOUTH. COULD
PICK UP A TENTH OR TWO OF ICE ACCUMULATION. SEAS HOLDING AT 4 TO 5
FT.
A STRONGER STORM SYSTEM WILL BRING SOLID GALE FORCE WINDS OF 25
TO 40 KT TUES...WITH SEAS BUILDING ABOVE 10 FT. /JBONK
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY FOR NORTHERN
OREGON CASCADES-UPPER HOOD RIVER VALLEY.
WINTER STORM WARNING UNTIL 10 AM PST SATURDAY FOR CENTRAL
COLUMBIA RIVER GORGE-GREATER PORTLAND METRO AREA-NORTH
OREGON COAST-WESTERN COLUMBIA RIVER GORGE.
WINTER STORM WARNING UNTIL 6 AM PST SATURDAY FOR CENTRAL
WILLAMETTE VALLEY-COAST RANGE OF NORTHWEST OREGON-NORTHERN
OREGON CASCADE FOOTHILLS.
WINTER STORM WARNING UNTIL 6 PM PST SATURDAY FOR CASCADE
FOOTHILLS IN LANE COUNTY-CENTRAL COAST RANGE OF WESTERN
OREGON-SOUTH WILLAMETTE VALLEY.
WINTER WEATHER ADVISORY UNTIL 6 PM PST SATURDAY FOR CASCADES IN
LANE COUNTY.
WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY FOR LOWER
COLUMBIA.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CENTRAL
OREGON COAST.
WA...WINTER STORM WARNING UNTIL 10 AM PST SATURDAY FOR CENTRAL
COLUMBIA RIVER GORGE-GREATER VANCOUVER AREA-WESTERN
COLUMBIA RIVER GORGE.
WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY FOR I-5
CORRIDOR IN COWLITZ COUNTY-SOUTH WASHINGTON CASCADE
FOOTHILLS.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST SATURDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION...
NWS PORTLAND OR
248 PM PST FRI FEB 7 2014
.SYNOPSIS...THE SECOND SYSTEM IN A ONE-TWO-THREE PUNCH OF WINTRY
WEATHER FOR NORTHWEST OREGON IS BRINGING WIDESPREAD SNOW TO THE AREA
THROUGH THIS EVENING. SEVERAL INCHES OF SNOW
ARE LIKELY FOR MOST OF OUR NORTHWEST OREGON ZONES BY SATURDAY
MORNING...EVENTUALLY CHANGING TO SLEET AND FREEZING RAIN FROM THE
SOUTH. SOUTHWEST WASHINGTON WILL BE ON THE NORTHERN FRINGE OF THE
HEAVIER PRECIPITATION. THE THIRD SYSTEM WILL BRING MORE WINTRY
WEATHER TO OUR AREA LATER SATURDAY INTO SUNDAY...BUT THERE IS STILL A
BIT OF UNCERTAINTY IN HOW FAR NORTH THIS SYSTEMS IMPACTS WILL REACH.
EXPECT SNOW TO DOMINATE THE NORTH WITH A MIX POSSIBLE FARTHER SOUTH.
OVERALL A VERY COMPLEX WINTER WEATHER SITUATION UNFOLDING OVER
SOUTHWEST WASHINGTON AND NORTHWEST OREGON THROUGH SUNDAY. NEXT WEEK
THERE WILL BE A TURN TOWARD MORE TYPICAL WEATHER FOR THE REGION WITH
MILDER PACIFIC FRONTAL SYSTEMS BRINGING PERIODS OF RAIN.
&&
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...WIDESPREAD SNOW ACROSS
THE AREA THIS AFTERNOON...THOUGH MUCH LIGHTER WINDS TODAY EXCEPT IN
THE GORGE AND TOWARD EAST COUNTY. THE SURFACE LOW WELL OFFSHORE OF
THE COLUMBIA RIVER HAS BECOME STATIONARY AS AN OCCLUDING
FRONT/SURFACE LOW IS BECOMING MORE DOMINANT AND QUITE IMPRESSIVE WITH
CONVECTIVE LOOKING ELEMENTS EMBEDDED. THIS IS IN RESPONSE A
STRENGTHENING UPPER LEVEL JET POINTED AT THE SOUTH OREGON COAST.
ALONG THE WARM FRONTAL BOUNDARY A SHEARED OUT THOUGH SOMEWHAT POTENT
VORT MAX IS RIDING. THIS WAVE COUPLED WITH MOIST WARM ADVECTION IS
EXPECTED TO REINVIGORATE PRECIPITATION THIS EVENING. NOT LIKE THE
CURRENT PRECIPITATION RATES ARE NO SLOUCH. THE CURRENT SNOW MOVING
NORTH THROUGH THE VALLEY IS MORE WARM ADVECTION INDUCED...WITH SOME
MID LEVEL FRONTOGENESIS AIDING IN SOME LOCAL ENHANCEMENT...ESPECIALLY
AS THE SNOW SPREADS NORTH.
PRECIPITATION TYPE IS OUR MAIN CONCERN WITH THIS SECOND SYSTEM...NOT
TO IGNORE THE WIDEPSREAD SNOW THAT WILL CONTINUE THROUGH THIS
EVENING. FORTUNATELY FOR MOST AREAS SNOW WILL DOMINATE. THIS
INCLUDES EVERYWHERE FROM SALEM NORTHWARD EXCEPT FOR THE IMMEDIATE
COAST...WHERE SIMILAR SNOW TOTALS OR SLIGHTLY LESS ARE EXPECTED DUE
TO NOW REAL BANDING SETTING UP JUST YET. THE SITUATION ALONG THE
COAST IS A BIT COMPLICATED. THE CENTRAL COAST TO THE SOUTH OF
NEWPORT IS ABOVE FREEZING...SO RAIN WILL NOW DOMINATE FROM THIS
POINT FORWARD. WITH THE WARMER AIR FROM THE SOUTH NUDGING
NORTH...SOME FREEZING RAIN SLEET AND RAIN WILL MIX IN FROM NEWPORT
NORTH. THIS IS ALSO THE CASE IN CENTRAL COAST RANGE WHERE SILETZ HAS
HAD MOSTLY SNOW AND NOW A MIX OF SNOW AND FREEZING RAIN AFTER SOME
FZRA EARLIER TODAY.THERE ARE SOME SELECT LOCATIONS ALONG THE NORTH
COAST WHERE RAIN MAY ALSO BE THE CASE...BUT WITH PRECIPITATION RATES
PICKING UP...SNOW WILL CONTINUE IN SPOTS. THE BIG HEADACHE IS AS WE
CONTINUE TO MONITOR RAWS STATIONS IN THE CENTRAL COAST RANGE THAT
LIE ANYWHERE FROM 1500-2000 FT ABOVE THE GROUND...WE TRULY SEE THE
BATTLE BETWEEN THE COLDER DENSE AIR THAT HAS BEEN IN PLACE AND THE
WARMER AIR TO THE SOUTH. HIGH POINT AND GOODWIN PEAK TO THE
SOUTHWEST OF EUGENE ARE 32-34 AND HAVE BEEN WARMER WHICH MAY ALSO BE
DUE TO THE PRECIP COOLING THINGS OFF...WITH WILKINSON AND VILLAGE
CREEK TO THE NORTHWEST OF EUGENE AT 30...WHICH IS UP A FEW DEGREES.
THE RAP WOULD SUGGEST THAT SNOW WILL REMAIN THE DOMINANT P-TYPE
THROUGH THE AFTERNOON...THEN AS THE SURFACE LOW TAKES AIM...ALL
GUIDANCE...INCLUDING THE RAP AND ECMWF BRING IN A WARM NOSE THAT
SHOULD...AT LEAST AT TIMES MIX FREEZING RAIN OR SLEET IN. THE
CONCERN IS THAT OUR HEAVIEST PRECIPITATION IS STILL TO COME THIS
EVENING WHEN THE WARM NOSE IS SUGGESTED TO COME IN. THIS WILL MAKE
ALL THE DIFFERENCE BETWEEN CONTINUED MODERATE TO HEAVY SNOW...OR
SIGNIFICANT ICE ACCUMULATIONS. FEELING WITH A LOW TRACK TO THE SOUTH
THAT SNOW WILL DOMINATE...THOUGH IGNORING ALL GUIDANCE IS
CHALLENGING SO WILL NEED TO KEEP THE FREEZING RAIN THREAT MENTIONED.
WE ARE HEARING OF SOME FZRA IN THE CASCADE FOOTHILLS.
THE SURFACE LOW PUSHES INTO THE SOUTHERN OREGON COAST AND THEN PASSES
BY TO THE SOUTH OF EUGENE AND WASHES OUT SOME. AGAIN BECAUSE OF
THIS...THE COLD AIR FARTHER NORTH DOES NOT SCOUR OUT. WHILE AREAS
NORTH GET ANOTHER LULL AND LIGHTER PRECIPITATION RATES THROUGH EARLY
AFTERNOON....THERE IS STILL A STRONG JET POINTED AT THE
AREA THAT WILL KEEP THINGS GOING IN THE SOUTHERN TIER AND INTO THE
CASCADES. THE SOUTHERN TIER WILL AGAIN BE A QUESTION MARK DUE TO THE
LOW PASSING BY TO THE SOUTH WHICH MAY ALLOW A TRANSITION BACK TO
SNOW...OR JUST CONTINUE SNOW IF THE FREEZING RAIN DOESN`T
MATERIALIZE.
ON SATURDAY AFTERNOON ANOTHER LOW RIDES A SIMILAR OR
SLIGHTLY FARTHER NORTH TRACK. THE GFS AND ECMWF ALLOW THE WARM NOSE
TO GET UP TO NEAR SALEM. THE NAM DOES THE SAME EVENTUALLY BRINGING UP
TO AURORA/WILSONVILLE AREA. MEANWHILE SOUNDINGS AND THE GENERAL
SYNOPTIC PATTERN SUGGEST ALL POINTS NORTH AND THROUGH THE COLUMBIA
RIVER GORGE REMAIN SNOW THROUGH THE NIGHT THIS LOW DOES THE SAME
THING ALL THE OTHERS DO...PASS BY SOUTH AND THEN WASH OUT. /KMD
&&
.LONG TERM...
SUNDAY THROUGH MONDAY...SUNDAY WILL LIKELY BE THE TRANSITION DAY OUT
OF THE SNOW TO RAIN. HOWEVER THERE WILL BE A PERIOD OF FREEZING RAIN
AND SLEET. THERE ARE STILL DIFFERENCES IN MODEL SOLUTIONS FOR THIS
TIME PERIOD...BUT TYPICALLY MODELS ARE TOO FAST IN MODERATING THE
AND HAVE TAKEN THIS INTO ACCOUNT. THE NORTH WILLAMETTE VALLEY AND
ESPECIALLY AREAS NEAR THE COLUMBIA RIVER GORGE WILL BE HAVE A WINTRY
MIX THROUGH LATE SUN...AND POSSIBLY A LITTLE LONGER. THE COLUMBIA
RIVER GORGE WILL LIKELY CONTINUE UNDER THE THREAT OF FREEZING RAIN
OR SLEET THROUGH MONDAY. ICE ACCUMULATION AMOUNTS WILL PROBABLY BE
IN THE 0.1 TO 0.2 INCH WITH THE HIGHER AMOUNTS IN THE NORTH
WILLAMETTE VALLEY AND GORGE. WILL HAVE TO WATCH HOW THE MODELS
HANDLE THIS CHANGING SITUATION.
MONDAY NIGHT NIGHT THROUGH FRIDAY...THE PACNW IS UNDER THE
STORM TRACK FOR THE WEEK AHEAD. BROAD LOW PRESSURE WILL SET UP OVER
THE GULF OF ALASKA WITH A BROAD RIDGE CENTERED JUST OFF THE BAJA
CALIFORNIA COAST. THIS WILL ALLOW A SERIES OF SHORT WAVES TO
PROGRESS ALONG JET STREAM AND BRING MORE FREQUENT PERIODS OF RAIN
AND MOUNTAIN SNOW AND FEWER DRY PERIODS. GENERALLY SPEAKING...WILL
SEE SNOW LEVELS FLUCTUATE BETWEEN 3000 FEET AND 5500 FEET DEPENDING
ON WHEN THE PASSING SHORT WAVES PUSH LEADING WARMER AIR SLIGHTLY
FURTHER NORTH. OVERALL...THIS APPEARS TO BE A GOOD PATTERN FOR
PRODUCING SNOW PACKS HIGHER IN THE CASCADES AS OVERNIGHT
TEMPERATURES WILL LARGELY STAY BELOW FREEZING. MODELS ARE IN DECENT
AGREEMENT WITH OVERALL TIMING OF INDIVIDUAL WAVES. PRECIP NOW
APPEARS TO BE FOCUSED ON TUESDAY/ TUESDAY EVENING...AND THEN
THURSDAY HEADING INTO THURSDAY NIGHT. MODELED QPF AMOUNTS VARY...NOT
SURPRISINGLY...BETWEEN THE MEDIUM RANGE MODELS AND THE INDIVIDUAL
WAVES...BUT IT DOES APPEAR THE PACNW WILL BE IN THE CROSS HAIRS OF
THE PACIFIC MOISTURE FEED. THUS DO NOT FEEL OVERLY COMFORTABLE
REGARDING THE NATURE OF ANY ONE SPECIFIC SYSTEM. FORTUNATELY...THERE
DO APPEAR TO BE AROUND 12 HOUR BREAKS BETWEEN SYSTEMS.THERE IS ONE
FEATURE THE ECMWF IS TRENDING TOWARD...IS A STRONG WAVE RIDING ON A
FRONT THAT MAY BRING QUITE A BIT MORE RAIN AND WIND THAN IN THE
CURRENT FORECAST FOR THE TUE NIGHT WED TIME PERIOD. HAVE TRENDED
FORECAST TOWARD THAT SOLUTION FOR NOW./MH
&&
.AVIATION...PREVIOUS DISCUSSION...18Z TAF PACKAGE. NEXT ROUND OF
SNOW HAS PROGRESSED INLAND ABOUT TO REACH AS FAR NORTH AS KSLE.
WILL CONTINUE TO SEE THIS BAND DRIFT NORTH REACHING
KHIO...KPDX...AND KTTD BY 20Z IF NOT A BIT SOONER AND KAST AN HOUR
OR SO LATER. THIS IS ALL FASTER THAN MODELS HAVE INDICATED AND
HAVE ADAPTED TAFS TO MATCH. MAIN CHALLENGE WILL BE THE PROBABLE
TRANSITION TO FREEZING RAIN AND OR SLEET ACROSS THE CENTRAL AND
SOUTH VALLEY THIS AFTERNOON AND EVENING. HAVE ALREADY SEEN THE
TRANSITION AT KONP. MODERATE SNOW AT KEUG WILL BEGIN TO GIVE WAY
WITH THE BEST GUESS OCCURRING AT 22Z AND AT KSLE AT 23Z. EXPECT TO
SEE A TENTH OR TWO OF ICE ACCUMULATION ON TOP OF THE ONGOING SNOW.
DEEPER EAST WINDS ACROSS THE NORTH CASCADES SHOULD LIMIT THE
NORTHWARD PROGRESSION OF THE FREEZING RAIN DURING NEXT 24 HOURS.
FIRST GUESS TODAY MAY SEE KHIO KTTD AND KPDX CHANGE TO FZRA AROUND
09/03 Z SATURDAY EVENING BUT IT APPEARS THE BULK OF PRECIP SHOULD
END BY THEN. HOWEVER...ACCUMULATING ICE IS STILL LIKELY.
KPDX AND APPROACHES...LIGHT SNOW SHOWERS WILL REACH THE FIELD
AROUND 20Z AS TODAY`S PRECIP BAND DRIFTS NORTHWARD. PEAK SNOW WILL
INTENSIFY BEGINNING CLOSER TO 00Z WITH PERIODS OF HEAVY
ACCUMULATION EXPECTED 08/00 TO 08/03Z. ALSO EXPECT BLSN TO OBSCURE
NEARSURFACE VSBY AT THAT TIME. CONTINUE TO EXPECT AROUND 3
INCHES OF TOTAL ACCUMULATION BY LATER EVENING. LOOKS LIKE SNOW
WILL EVENTUALLY BECOME MORE SHOWERY. CURRENT THOUGHTS BRING FIRST
FZRA POSSIBILITY TO KPDX AROUND 09/03Z.
&&
.MARINE...BROAD AREA OF LOW PRES OVER NE PAC...WITH HIGH PRES WELL
INLAND. OFFSHORE WINDS HAVE GRADUALLY INCREASED OVER THE LAST FEW
HOURS. REALITY IS OUT-PERFORMING THE MODELS AS A SMALL SURFACE LOW
WILL MOVE ASHORE NEAR NORTH BEND OREGON. THIS IS DRAGGING THE
EASTERLY GRADIENT FURTHER DOWN THE COAST AND BRINGING SMALL CRAFT
ADVISORY LEVEL WINDS TO THE CENTRAL COAST GAPS. AS SUCH HAVE ADDED
THE REMAINING COASTAL ZONES TO THE ADVISORY. THE CENTRAL COAST
ZONES MAY ACTUALLY EASE UP CLOSER TO MIDNIGHT RATHER THAN 4 AM.
ADDITIONALLY...FREEZING RAIN IS OCCURRING NEAR NEWPORT AND WILL
PROGRESS NORTHWARD UP THE COAST THROUGH THE EVENING...PERHAPS
REACHING AS FAR AS KAST BUT MORE LIKELY SEASIDE AND SOUTH. COULD
PICK UP A TENTH OR TWO OF ICE ACCUMULATION. SEAS HOLDING AT 4 TO 5
FT.
A STRONGER STORM SYSTEM WILL BRING SOLID GALE FORCE WINDS OF 25
TO 40 KT TUES...WITH SEAS BUILDING ABOVE 10 FT. /JBONK
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY FOR NORTHERN
OREGON CASCADES-UPPER HOOD RIVER VALLEY.
WINTER STORM WARNING UNTIL 10 AM PST SATURDAY FOR CENTRAL
COLUMBIA RIVER GORGE-GREATER PORTLAND METRO AREA-NORTH
OREGON COAST-WESTERN COLUMBIA RIVER GORGE.
WINTER STORM WARNING UNTIL 6 AM PST SATURDAY FOR CENTRAL
WILLAMETTE VALLEY-COAST RANGE OF NORTHWEST OREGON-NORTHERN
OREGON CASCADE FOOTHILLS.
WINTER STORM WARNING UNTIL 6 PM PST SATURDAY FOR CASCADE
FOOTHILLS IN LANE COUNTY-CENTRAL COAST RANGE OF WESTERN
OREGON-SOUTH WILLAMETTE VALLEY.
WINTER WEATHER ADVISORY UNTIL 6 PM PST SATURDAY FOR CASCADES IN
LANE COUNTY.
WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY FOR LOWER
COLUMBIA.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CENTRAL
OREGON COAST.
WA...WINTER STORM WARNING UNTIL 10 AM PST SATURDAY FOR CENTRAL
COLUMBIA RIVER GORGE-GREATER VANCOUVER AREA-WESTERN
COLUMBIA RIVER GORGE.
WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY FOR I-5
CORRIDOR IN COWLITZ COUNTY-SOUTH WASHINGTON CASCADE
FOOTHILLS.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST SATURDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
921 PM CST FRI FEB 7 2014
.UPDATE...EVENING UPDATE.
BASED ON CURRENT RADAR TRENDS...IT APPEARS THAT MOST OF NORTH
MISSISSIPPI WILL AT LEAST SEE ACCUMULATING SNOW NEAR AN INCH WITH
ISOLATED AREAS POSSIBLY SEEING A BIT MORE. TO ADDRESS THIS...HAVE
ISSUED A NEW WINTER WEATHER ADVISORY TO INCLUDE THE REST OF WEST
TENNESSEE AND NORTH MISSISSIPPI. BASED ON THE LATEST HRRR MODEL
AND SREF GUIDANCE...ENHANCED LIFT AHEAD OF A POTENT SHORTWAVE WILL
INCREASE BANDING OF SNOW...LEADING TO HEAVY SNOW SHOWERS AT TIMES.
AS THE WAVE SWINGS THROUGH...THE HEAVIEST SNOW WILL OCCUR OVER THE
NEXT FEW HOURS.
WE HAVE ALREADY RECEIVED A FEW REPORTS OF ROADS BECOMING SNOW
COVERED...MAINLY IN POINSETT AND CROSS COUNTIES IN EASTERN
ARKANSAS...AND EVEN A FEW SPOTS IN NORTHERN SHELBY COUNTY TENNESSEE.
THIS TREND IS EXPECTED TO CONTINUE ACROSS THE REST OF THE MID-SOUTH.
NEW ZONES AND UPDATED PRODUCTS ARE ALREADY AVAILABLE.
AC3
&&
.PREV DISCUSSION... /ISSUED 517 PM CST FRI FEB 7 2014/
DISCUSSION... /ISSUED 408 PM CST FRI FEB 7 2014/
DISCUSSION...WATER VAPOR SATELLITE/UPPER AIR PROFILER TRENDS THIS
AFTERNOON INDICATE AN SHORTWAVE TROUGH MOVING ACROSS THE
SOUTHERN PLAINS. CLOUDY SKIES PERSIST ACROSS THE MID SOUTH AS OF 3
PM CST WITH TEMPERATURES PREDOMINANTLY IN THE TEENS TO MIDDLE 20S
NORTH OF I-40 AND UPPER 20S TO THE LOWER 30S SOUTH. WINTER
PRECIPITATION POTENTIAL TONIGHT AND AGAIN SUNDAY NIGHT THROUGH
TUESDAY NIGHT REMAINS THE PREDOMINANT CHALLENGES IN THIS
AFTERNOON/S FORECAST.
SHORT TERM...(TONIGHT THROUGH SUNDAY)...A SHORTWAVE TROUGH OVER
THE SOUTHERN PLAINS WILL MOVE INTO THE LOWER MISSISSIPPI VALLEY
TONIGHT. THIS HAS HELPED TO ENHANCE LIFT ACROSS THE LOWER
MISSISSIPPI VALLEY LATE THIS AFTERNOON AS EVIDENT IN THE LATEST
REGIONAL WSR-88D RADAR TRENDS. 290-295K SURFACES SHOW INCREASING
ISENTROPIC ASCENT THROUGHOUT THE NIGHT. BASED ON THE LATEST SHORT
TERM TRENDS DECIDED TO EXTEND THE WINTER WEATHER ADVISORY A BIT
FURTHER SOUTHWEST AS ACTIVITY OVER NORTHERN LOUISIANA MAY MOVE
ACROSS AREAS SOUTH OF I-40 TONIGHT. AT THIS TIME...FEEL THE BEST
POTENTIAL FOR SNOW REACHING ONE INCH WILL BE ACROSS AREAS MAINLY
ALONG AND NORTH OF I-40...EAST ARKANSAS SOUTH OF I-40...PORTIONS
OF NORTHWEST MISSISSIPPI. ONE INCH TO PERHAPS LOCALLY 2 INCHES IS
POSSIBLE ACROSS THE NORTH WITH AMOUNTS AROUND 1 INCH ACROSS EAST
ARKANSAS/NORTHWEST MISSISSIPPI. EVENING SHIFT WILL CONTINUE TO
SHORT MONITOR TRENDS AND ADJUST HEADLINES IF NECESSARY.
A BREAK IN THE PRECIPITATION IS EXPECTED FOR SATURDAY AS THE
SHORTWAVE MOVES EAST AND HIGH PRESSURE RETURNS THROUGH SUNDAY.
TEMPERATURES WILL REMAIN BELOW NORMAL WITH TEMPERATURES MODERATING
INTO THE 40S SOUTH OF I-40 ON MONDAY.
LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)...A VERY COMPLEX
PATTERN WILL TAKE SHAPE ACROSS THE LOWER MISSISSIPPI VALLEY
BEGINNING SUNDAY NIGHT AS AN ARCTIC COLD FRONT DROPS DOWN INTO THE
LOWER MISSISSIPPI VALLEY AND PRECIPITATION DEVELOPS ACROSS THE
REGION. PRECIPITATION NORTH OF I-40 IS EXPECTED TO START OFF AS
SNOW...WITH A TRANSITION TO MIXED PRECIPITATION /FREEZING
RAIN...SLEET...SNOW/ LATER SUNDAY NIGHT INTO MONDAY. 12Z MODELS
DISAGREE WITH THE DEPTH OF THE COLD AIR WITH THIS SYSTEM AND
SUBSEQUENT PRECIPITATION TYPES/AMOUNTS ARE STILL SOMEWHAT
UNCERTAIN AT THIS POINT. FURTHER ADJUSTMENTS TO PRECIPITATION
TYPES/AMOUNTS ARE LIKELY WHEN MODELS COME INTO BETTER AGREEMENT.
PRECIPITATION CHANCES WILL GRADUALLY TRANSITION SOUTH OF I-40 BY
TUESDAY. ANOTHER UPPER LEVEL SHORTWAVE WILL MOVE ACROSS THE REGION
TUESDAY NIGHT AND WEDNESDAY WITH THE BEST PRECIPITATION CHANCES
OCCURRING MAINLY SOUTH OF I-40. PRECIPITATION TYPE ISSUES MAY
STILL REMAIN WITH THIS SECOND SYSTEM WITH ADDITIONAL ADJUSTMENTS
LIKELY DURING THIS TIMEFRAME.
&&
.AVIATION...
00Z TAF SET
SNOW ALREADY BEGINNING TO FALL ACROSS LOCATIONS WEST OF LITTLE
ROCK. TIMING LOOKED GOOD IN TAFS THUS LEFT ALONE. FOR
KMEM...EXPECT -SN AFTER 2Z WITH HEAVIER SNOW OCCURRING BETWEEN
4-8Z. VSBYS/CIGS WILL REDUCE TO IFR OR MVFR AS SNOW STARTS.
ACCUMULATIONS EXPECTED TO BE AROUND AN INCH. LOW CIGS WILL
CONTINUE FOR SEVERAL HOURS AFTER SNOW TAPERS OFF. LIGHT AND
VARIABLE WINDS EXPECTED THROUGH THE PERIOD.
KRM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 24 40 28 44 / 70 10 10 10
MKL 21 38 23 41 / 60 10 10 10
JBR 19 33 23 38 / 70 10 10 10
TUP 26 46 28 49 / 60 10 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR CLAY-
CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-
MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR DUNKLIN-
PEMISCOT.
MS...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR ALCORN-
BENTON MS-CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-
LAFAYETTE-LEE MS-MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-
QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-
YALOBUSHA.
TN...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR BENTON TN-
CARROLL-CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-
HARDEMAN-HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-
MADISON-MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
927 AM EST THU FEB 6 2014
.DISCUSSION...
LIGHT SNOW IS PERSISTING ACROSS PORTIONS OF SW VA THIS MORNING. IT
SHOULD BEGIN TO TAPER OFF IN THE EARLY AFTERNOON AS RUC SOUNDINGS
SHOW A DRYING TREND ALOFT. NO SIGNIFICANT ACCUMULATION IS
EXPECTED...BUT WILL UPDATE TO ADD A POP MENTION THROUGH EARLY
AFTERNOON. TEMPERATURES WILL ALSO NEED TO BE ADJUSTED DOWNWARD
ACROSS THE ENTIRE AREA BASED ON CLOUD COVER AND LATEST GUIDANCE.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
356 PM CST THU FEB 6 2014
.DISCUSSION...
THE UPPER LEVEL DISTURBANCE RESPONSIBLE FOR THE SNOW OVER THE
NORTHERN HALF OF THE CWA TODAY HAS MOVED QUICKLY OFF TO THE EAST
BUT THE NEXT ONE IS RIGHT ON ITS HEELS. THIS UPPER LEVEL SHORTWAVE
IS CURRENTLY LOCATED IN SOUTHERN CALIFORNIA AND WILL RAPIDLY
MOVE EAST AND MOVE ACROSS TEXAS DURING THE DAY TOMORROW. MOST
MODEL GUIDANCE DID NOT HANDLE THE STRENGTH OF THE FIRST SYSTEM
VERY WELL...BUT THE BETTER PERFORMERS WERE THE NAM AND RAP AND
THEREFORE WILL BE LEANING IN THEIR DIRECTION FOR THE FORECAST.
HOWEVER CONFIDENCE IN TOMORROWS FORECAST IS VERY LOW GIVEN OUR
FORECAST OF FREEZING AND FROZEN PRECIP IS NOT REALLY SUPPORTED IN
JUST ABOUT ALL OF THE MODEL GUIDANCE...BUT WE ARE WARY OF THE
STRENGTH OF THIS NEXT SYSTEM ALSO BEING UNDERESTIMATED.
ONCE AGAIN FORCING FOR ASCENT WILL BE STRONG BUT THE MAIN ISSUE IS
THE AMOUNT OF MOISTURE AVAILABLE FOR PRECIPITATION. THERE IS
ACTUALLY GOOD MODEL AGREEMENT THAT HIGH MOISTURE AND CONDITIONAL
SYMMETRIC INSTABILITY WILL BE AVAILABLE FOR SLANTWISE CONVECTION
AND BANDED SNOWFALL IN THE AREA OF THE ATMOSPHERE NEAR 500 TO
600MB OR NEAR 18-22 THOUSAND FEET. THIS BAND IS EXPECTED TO TRACK
ACROSS THE AREA ALONG AND NORTH OF INTERSTATE 20 DURING THE DAY
TOMORROW AND WILL LIKELY BE SEEN ON AREA RADARS. THE MODELS DIFFER
ON JUST HOW DRY THE AIRMASS WILL BE IN A LAYER NEAR 700 TO 850MB
OR ABOUT 5-10 THOUSAND FEET. WITH THE SOLE EXCEPTION OF THE ECMWF
AND ONE SREF MEMBER...ALL MODEL GUIDANCE INDICATES THE FALLING
SNOW WILL SUBLIMATE WHEN IT REACHES THIS DRY LAYER AND NOT REACH
THE SURFACE. HOWEVER AM NOT READY TO BUY INTO THIS JUST YET...AT
LEAST NOT UNTIL WE CAN SEE THE MOISTURE PROFILES FROM THE EVENING
RAOBS AT MAF AND DRT. OBVIOUSLY THERE WAS A LOT MORE MOISTURE
AVAILABLE IN THE AREA THAN WAS FORECAST TODAY AND IT IS LIKELY
STILL HANGING AROUND. SINCE MODEL SOUNDINGS FROM BOTH THE RAP AND
NAM INDICATE FAIRLY STEEP LAPSE RATES IN THE SNOW PRODUCING AREA
WHICH WOULD ENHANCE SNOWFALL INTENSITY...BELIEVE MORE SATURATION
WILL OCCUR FROM TOP DOWN THAN MODELS INDICATE. THUS WILL FORECAST
ANOTHER ROUND OF LIGHT SNOW ACROSS THE AREA NORTH OF I-20
TOMORROW...WITH POPS FOR MEASURABLE AMOUNTS OF SNOW AT 20 PERCENT
AND ACCUMULATIONS AT JUST A TENTH OF AN INCH OR LESS.
FARTHER SOUTH ACROSS CENTRAL TEXAS AND OUR SOUTHEAST ZONES...THE
SOUTHERLY WINDS AT 850MB WILL BE BRINGING WARMER AIR AND RICH GULF
MOISTURE NORTHWARD IN A HURRY AS THE SHORTWAVE APPROACHES. LOW
LEVEL ISENTROPIC CHARTS SHOW SUBTLE LIFT OCCURRING NEAR 925MB
WHICH WOULD CORRESPOND TO SOME LIGHT DRIZZLE DEVELOPING BEFORE DAY
BREAK. TEMPERATURES AT THIS TIME WOULD BE BELOW FREEZING.
PRECIPITATION WILL LIKELY INCREASE IN COVERAGE AND INTENSITY
ACROSS THE SOUTHEAST ZONES DURING THE AFTERNOON HOURS AS
ISENTROPIC LIFT RAMPS UP. HOWEVER TEMPERATURES MAY RISE ABOVE
FREEZING BEFORE THIS OCCURS. MODEL GUIDANCE MAY BE TOO QUICK TO
WARM TEMPS ABOVE FREEZING AS NORTH WINDS WILL HOLD IN THROUGH THE
MORNING HOURS AND THICK CLOUD COVER SHOULD KEEP TEMPS FROM RISING
MUCH IF ANY. HOWEVER WHEN THE PRECIP STARTS IT IS ASSOCIATED WITH
LOW LEVEL WARM ADVECTION...AND BELIEVE THAT TEMPS WILL TRY TO WARM
ABOVE FREEZING DURING THE AFTERNOON FROM SOUTHWEST TO NORTHEAST.
SO IT MAY START AS LIGHT FREEZING DRIZZLE/RAIN BUT SHOULD TRANSITION
TO REGULAR DRIZZLE OR RAIN DURING THE EVENT. AFTER A COUPLE OF
DAYS OF VERY COLD SUBFREEZING TEMPS...ROAD SURFACES ARE BELOW
FREEZING AND ANY FREEZING PRECIPITATION WOULD STICK ON IMPACT. DO
NOT EXPECT MUCH ACCUMULATION OF ICE AS PRECIPITATION INTENSITY
WILL BE LIGHT...BUT STILL THIS CAN BE A MAJOR TRAFFIC HAZARD
ESPECIALLY IF PEOPLE ARE NOT AWARE OF ICE ON ROADS. HAVE ISSUED A
WINTER WEATHER ADVISORY ACROSS THE SOUTHERN AND SOUTHEAST ZONES
FOR THE LIGHT FREEZING PRECIPITATION TO GET THE WORD OUT ABOUT
THE POTENTIAL TRAVEL ISSUES TOMORROW. THANKS TO WFO EWX/HGX/SHV
FOR THE COORDINATION.
THIS SYSTEM WILL CLEAR THE AREA FRIDAY NIGHT WITH SKIES CLEARING
SATURDAY. TEMPERATURES WILL REBOUND INTO THE 50S AND 60S BY
SATURDAY AFTERNOON AS DOWN SLOPE WESTERLY WINDS SPREAD ACROSS THE
REGION. THE WARM UP WILL BE SHORT LIVED AS ANOTHER FRONT SLIDES
SOUTH THROUGH THE AREA ON SUNDAY. HAVE SIDED WITH THE FASTER
ECMWF/GFS FORECASTS WITH THIS FRONT...AS IT IS LIKELY TO BE
SHALLOW AND WANT TO SPILL SOUTH DUE TO ITS HIGHER DENSITY.
THE EARLY NEXT WEEK FORECAST WILL FEATURE INCREASING CHANCES OF
PRECIPITATION. THE COLD AIR BEHIND THE SUNDAY FRONT WILL SETTLE IN
OVER THE AREA WITH HIGHS IN THE 40S AND LOWS IN THE 30S. AS
ANOTHER STRONG UPPER LEVEL SYSTEM MOVES IN FROM THE WEST...
ISENTROPIC LIFT WILL SET UP OVER THE TOP OF THE COLD DOME AND WE
SHOULD SEE CHANCES OF PRECIP STARTING MONDAY AND INCREASING INTO
TUESDAY. THE GFS AND CANADIAN ARE MOST AGGRESSIVE WITH QPF OUTPUT
WITH THIS SYSTEM BUT THE ECMWF CONTINUES TO BE RATHER TAME.
FURTHERMORE THE GFS/CANADIAN WOULD SUPPORT A WIDESPREAD WINTER MIX
EVENT FOR THE REGION...BUT AGAIN THE ECMWF DOES NOT SHOW THIS. FOR
NOW WE WILL CONTINUE TO ADVERTISE SOME WINTER PRECIP OVER THE
NORTHERN 2 ROWS OF COUNTIES TUESDAY AND TUESDAY NIGHT. THIS IS THE
REGION THAT IS MOST CLIMATOLOGICALLY FAVORED TO SEE WINTER PRECIP
AND WITH MODEL AGREEMENT LOW...IT MAKES SENSE TO KEEP THE WINTER
MIX UP THERE AND SPREAD IT SOUTH SHOULD THE ECMWF COME IN LINE
WITH THE OTHER GUIDANCE AND CONFIDENCE INCREASES.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 21 34 29 57 34 / 10 20 10 0 0
WACO, TX 23 35 29 64 38 / 20 20 10 0 0
PARIS, TX 21 33 25 53 33 / 10 20 20 0 0
DENTON, TX 19 33 26 56 30 / 10 20 10 0 0
MCKINNEY, TX 21 33 26 55 31 / 10 20 10 0 0
DALLAS, TX 22 34 30 57 37 / 10 20 10 0 0
TERRELL, TX 23 34 27 57 34 / 10 20 10 0 0
CORSICANA, TX 24 34 30 60 38 / 10 30 10 0 0
TEMPLE, TX 24 35 29 65 38 / 20 30 10 0 0
MINERAL WELLS, TX 19 37 26 60 31 / 10 20 10 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 AM TO 3 PM CST FRIDAY FOR
TXZ156>160-174-175.
WINTER WEATHER ADVISORY FROM 9 AM TO 6 PM CST FRIDAY FOR TXZ122-
135-146>148-161-162.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1154 AM CST THU FEB 6 2014
.AVIATION...
MVFR CIGS ACROSS THE RIO GRANDE VALLEY WILL CONTINUE TO LIFT THIS
MORNING. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH MUCH OF
THE TAF PERIOD AS RIDGING PREVAILS AT THE SFC. AN UPPER LEVEL
SYSTEM WILL MOVE ACROSS THE AREA TONIGHT ENABLING A CHANCE FOR
PRECIPITATION. WITH THE COLD AIRMASS REMAINING AT THE SFC...A MIX
OF -FZDZ/-IP/-SN WILL BE POSSIBLE DURING THE OVERNIGHT HOURS.MODELS
CONTINUE TO SUGGEST ANY FROZEN ACCUMULATIONS WILL BE LIGHT. CIGS
ARE EXPECTED TO LOWER TO MVFR FROM WEST TO EAST ACROSS THE REGION
FRIDAY MORNING. MODELS ARE THEN UNDECIDED WHETHER TO KEEP BASES AT
MVFR LEVELS...LOWER TO IFR...OR RAISE TO VFR DURING THE LATE
MORNING/EARLY AFTERNOON HOURS. SFC WINDS WILL BE N-NERLY 10 TO 15
KTS THROUGH THIS EVENING. WINDS AT KDRT WILL GRADUALLY VEER TO THE
SE BY EARLY FRIDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 1131 AM CST THU FEB 6 2014/
UPDATE...
THE WINTER WEATHER ADVISORY HAS BEEN ALLOWED TO EXPIRE. SPOTTER
REPORTS AND RADAR DATA CONFIRM SOME VERY LIGHT SNOW IS FALLING
ACROSS PORTIONS OF THE WESTERN HILL COUNTRY. SOME OF THIS ACTIVITY
MAY BRIEFLY MOVE INTO THE I-35 CORRIDOR. HOWEVER... WE ARE NOT
EXPECTING ANY ACCUMULATION. HIGH TEMPERATURES HAVE BEEN LOWERED
ONCE AGAIN AS CLOUD COVER AND COLD AIR ADVECTION WILL REMAIN
INTACT TODAY.
PREV DISCUSSION... /ISSUED 942 AM CST THU FEB 6 2014/
UPDATE...
WE HAVE LOWERED TODAY/S HIGH TEMPERATURES BY A FEW DEGREES ACROSS
MOST OF THE REGION. THE LATEST RUC13 AND SREF MODEL DATA SUGGESTS
HIGHS WILL REMAIN IN THE 30S ACROSS MOST AREAS...WITH TEMPS
STRUGGLING TO REACH FREEZING OVER THE HILL COUNTRY. HIGHS ALONG
THE I-35 CORRIDOR WILL STRUGGLE TO REACH THE MID 30S. NO CHANGES
TO THE WINTER WEATHER ADVISORY JUST YET AS THE LATEST RADAR DATA
CONTINUES TO SHOW SOME LIGHT ECHOES ACROSS THE HILL COUNTRY SLOWLY
MOVING INTO THE I-35 CORRIDOR. WE COULD SEE SOME LIGHT SNOW OR
GRAUPEL FROM THIS ACTIVITY. GIVEN THE LIGHT RADAR RETURNS...WOULD
NOT EXPECT ANY SIGNIFICANT ACCUMULATIONS FROM THIS ACTIVITY.
PREV DISCUSSION... /ISSUED 547 AM CST THU FEB 6 2014/
AVIATION...
VFR CONDITIONS AT I-35 SITES WITH MVFR AT KDRT. EXPECT THIS TREND
TO CONTINUE WITH COLD HIGH PRESSURE IN CONTROL OVER THE REGION.
ALL SLEET AND LIGHT SNOW SHOULD BE OUT OF THE AREA BY 14Z. CLOUDS
SHOULD REMAIN IN THE 4-6 THOUSAND FOOT RANGE THIS AFTERNOON.
CEILINGS WILL LOWER TO 2-4 THOUSAND FEET AFTER 01Z FRIDAY. AFTER
08Z TONIGHT WILL SEE ANOTHER UPPER LEVEL SYSTEM MOVE ACROSS WITH
LOW CHANCES FOR LIGHT FREEZING DRIZZLE. CURRENTLY FEEL THAT ANY
ACCUMULATIONS WOULD BE MINOR. NORTHERLY WINDS WILL DECREASE TO 10
TO 15 KNOTS THIS MORNING AND NEAR 10 KNOTS THIS AFTERNOON AND
OVERNIGHT.
PREV DISCUSSION... /ISSUED 525 AM CST THU FEB 6 2014/
UPDATE...
HAVE ISSUED A WINTER WEATHER ADVISORY FOR A BAND OF SLEET AND SNOW
FROM NORTHERN SAN ANTONIO ACROSS THE NEW BRAUNFELS AND SAN MARCOS
AREAS...THEN EAST TO LA GRANGE AND LEXINGTON. SLEET AND SNOW
ACCUMULATIONS UP TO ONE HALF INCH ARE POSSIBLE. THE BAND WILL MOVE
EAST BY 11 AM.
PREV DISCUSSION... /ISSUED 424 AM CST THU FEB 6 2014/
UPDATE...
ADDED MENTION OF SLEET FOR A BAND FROM HONDO TO SAN ANTONIO TO
BASTROP TO GIDDINGS. A DUSTING MAY BE POSSIBLE WITH THIS BAND.
PREV DISCUSSION... /ISSUED 341 AM CST THU FEB 6 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...
COLD ADVECTION CONTINUES ACROSS SOUTH CENTRAL TEXAS EARLY THIS
MORNING AS AN UPPER LEVEL TROUGH MOVES ACROSS THE BIG BEND REGION.
ISENTROPIC LIFT ASSOCIATED WITH THIS TROUGH WILL GENERATE VERY
LIGHT PRECIPITATION. CURRENT AND FORECAST SOUNDING DATA SHOW THAT
SNOW FLURRIES ARE THE LIKELY PRECIPITATION TYPE. NO ACCUMULATION
IS EXPECTED DUE TO A VERY DRY LOWER LEVEL AIRMASS. THE TROUGH WILL
MOVE NORTHEAST OF OUR AREA BY MIDDAY ENDING THE FLURRIES AS LIFT
ENDS. ANOTHER UPPER LEVEL TROUGH CURRENTLY SEEN APPROACHING THE
CALIFORNIA COAST WILL MOVE ACROSS TEXAS ON FRIDAY. ISENTROPIC LIFT
WILL DEVELOP LATE TONIGHT. A WARMER AND MORE MOIST AIRMASS ALOFT
WILL CREATE DRIZZLE OR FREEZING DRIZZLE. EVEN THOUGH MORE MOISTURE
WILL BE AVAILABLE...LITTLE OR NO ICE ACCUMULATION IS EXPECTED.
HOWEVER...A SLIGHTLY STRONGER SYSTEM WITH SLIGHTLY DEEPER MOISTURE
COULD PRODUCE LIGHT ICING ON BRIDGES...OVERPASSES AND OTHER
ELEVATED ROADS. SO...STAY TUNED FOR THE LATEST DEVELOPMENTS ON
THIS WEATHER EVENT. ISENTROPIC LIFT SLOWLY WANES WITH DRIZZLE
ENDING BY LATE FRIDAY EVENING. CLOUD COVER WILL MAKE TEMPERATURES
STRUGGLE TO REACH 40 MOST AREAS TODAY AND FRIDAY. AVERAGE HIGHS
ARE IN THE LOWER TO MID 60S.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
SOUTHWESTERLY WINDS DEVELOP ON SATURDAY AS THE SURFACE HIGH MOVES
AWAY LEADING TO A WARM DAY WITH HIGHS NEAR OR JUST ABOVE AVERAGE.
THE MODELS HAVE BECOME MORE DISAGREEABLE FOR SUNDAY AND MONDAY.
THE GFS BRINGS A WEAK BACKDOOR COLD FRONT INTO OUR AREA SUNDAY AND
LIFTS IT BACK NORTH MONDAY WITH A STRONGER COLD FRONT TUESDAY
WHILE THE ECMWF BRINGS A MODERATELY COLD FRONT THROUGH SUNDAY
NIGHT WITH A STRONGER PUSH OF COLD AIR TUESDAY. BOTH MODELS SHOW
AN UPPER LEVEL TROUGH MOVING ACROSS TEXAS LATE TUESDAY INTO
TUESDAY NIGHT. FOR NOW...WILL SIDE WITH THE GFS ON THE FRONT.
WARM ADVECTION SHOWERS ARE POSSIBLE MONDAY INTO MONDAY NIGHT WITH
A SLIGHTLY BETTER CHANCE OF SHOWERS WITH THE UPPER LEVEL TROUGH
TUESDAY INTO TUESDAY NIGHT. COLD AND DRY AGAIN FOR WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 34 26 41 35 67 / 10 10 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 34 24 39 33 66 / 10 10 20 10 -
NEW BRAUNFELS MUNI AIRPORT 35 27 38 33 68 / 20 10 20 10 -
BURNET MUNI AIRPORT 33 23 39 31 65 / 10 10 20 10 -
DEL RIO INTL AIRPORT 40 30 47 36 71 / 10 - - - -
GEORGETOWN MUNI AIRPORT 34 23 39 32 63 / 10 10 20 10 -
HONDO MUNI AIRPORT 37 28 42 34 70 / 10 10 20 10 -
SAN MARCOS MUNI AIRPORT 35 26 38 33 67 / 20 10 20 10 -
LA GRANGE - FAYETTE REGIONAL 36 29 39 35 63 / 20 10 20 20 10
SAN ANTONIO INTL AIRPORT 35 29 41 35 69 / 20 10 20 10 -
STINSON MUNI AIRPORT 36 30 40 34 69 / 10 10 20 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...25
SYNOPTIC/GRIDS...24
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1131 AM CST THU FEB 6 2014
.UPDATE...
THE WINTER WEATHER ADVISORY HAS BEEN ALLOWED TO EXPIRE. SPOTTER
REPORTS AND RADAR DATA CONFIRM SOME VERY LIGHT SNOW IS FALLING
ACROSS PORTIONS OF THE WESTERN HILL COUNTRY. SOME OF THIS ACTIVITY
MAY BRIEFLY MOVE INTO THE I-35 CORRIDOR. HOWEVER... WE ARE NOT
EXPECTING ANY ACCUMULATION. HIGH TEMPERATURES HAVE BEEN LOWERED
ONCE AGAIN AS CLOUD COVER AND COLD AIR ADVECTION WILL REMAIN
INTACT TODAY.
&&
.PREV DISCUSSION... /ISSUED 942 AM CST THU FEB 6 2014/
UPDATE...
WE HAVE LOWERED TODAY/S HIGH TEMPERATURES BY A FEW DEGREES ACROSS
MOST OF THE REGION. THE LATEST RUC13 AND SREF MODEL DATA SUGGESTS
HIGHS WILL REMAIN IN THE 30S ACROSS MOST AREAS...WITH TEMPS
STRUGGLING TO REACH FREEZING OVER THE HILL COUNTRY. HIGHS ALONG
THE I-35 CORRIDOR WILL STRUGGLE TO REACH THE MID 30S. NO CHANGES
TO THE WINTER WEATHER ADVISORY JUST YET AS THE LATEST RADAR DATA
CONTINUES TO SHOW SOME LIGHT ECHOES ACROSS THE HILL COUNTRY SLOWLY
MOVING INTO THE I-35 CORRIDOR. WE COULD SEE SOME LIGHT SNOW OR
GRAUPEL FROM THIS ACTIVITY. GIVEN THE LIGHT RADAR RETURNS...WOULD
NOT EXPECT ANY SIGNIFICANT ACCUMULATIONS FROM THIS ACTIVITY.
PREV DISCUSSION... /ISSUED 547 AM CST THU FEB 6 2014/
AVIATION...
VFR CONDITIONS AT I-35 SITES WITH MVFR AT KDRT. EXPECT THIS TREND
TO CONTINUE WITH COLD HIGH PRESSURE IN CONTROL OVER THE REGION.
ALL SLEET AND LIGHT SNOW SHOULD BE OUT OF THE AREA BY 14Z. CLOUDS
SHOULD REMAIN IN THE 4-6 THOUSAND FOOT RANGE THIS AFTERNOON.
CEILINGS WILL LOWER TO 2-4 THOUSAND FEET AFTER 01Z FRIDAY. AFTER
08Z TONIGHT WILL SEE ANOTHER UPPER LEVEL SYSTEM MOVE ACROSS WITH
LOW CHANCES FOR LIGHT FREEZING DRIZZLE. CURRENTLY FEEL THAT ANY
ACCUMULATIONS WOULD BE MINOR. NORTHERLY WINDS WILL DECREASE TO 10
TO 15 KNOTS THIS MORNING AND NEAR 10 KNOTS THIS AFTERNOON AND
OVERNIGHT.
PREV DISCUSSION... /ISSUED 525 AM CST THU FEB 6 2014/
UPDATE...
HAVE ISSUED A WINTER WEATHER ADVISORY FOR A BAND OF SLEET AND SNOW
FROM NORTHERN SAN ANTONIO ACROSS THE NEW BRAUNFELS AND SAN MARCOS
AREAS...THEN EAST TO LA GRANGE AND LEXINGTON. SLEET AND SNOW
ACCUMULATIONS UP TO ONE HALF INCH ARE POSSIBLE. THE BAND WILL MOVE
EAST BY 11 AM.
PREV DISCUSSION... /ISSUED 424 AM CST THU FEB 6 2014/
UPDATE...
ADDED MENTION OF SLEET FOR A BAND FROM HONDO TO SAN ANTONIO TO
BASTROP TO GIDDINGS. A DUSTING MAY BE POSSIBLE WITH THIS BAND.
PREV DISCUSSION... /ISSUED 341 AM CST THU FEB 6 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...
COLD ADVECTION CONTINUES ACROSS SOUTH CENTRAL TEXAS EARLY THIS
MORNING AS AN UPPER LEVEL TROUGH MOVES ACROSS THE BIG BEND REGION.
ISENTROPIC LIFT ASSOCIATED WITH THIS TROUGH WILL GENERATE VERY
LIGHT PRECIPITATION. CURRENT AND FORECAST SOUNDING DATA SHOW THAT
SNOW FLURRIES ARE THE LIKELY PRECIPITATION TYPE. NO ACCUMULATION
IS EXPECTED DUE TO A VERY DRY LOWER LEVEL AIRMASS. THE TROUGH WILL
MOVE NORTHEAST OF OUR AREA BY MIDDAY ENDING THE FLURRIES AS LIFT
ENDS. ANOTHER UPPER LEVEL TROUGH CURRENTLY SEEN APPROACHING THE
CALIFORNIA COAST WILL MOVE ACROSS TEXAS ON FRIDAY. ISENTROPIC LIFT
WILL DEVELOP LATE TONIGHT. A WARMER AND MORE MOIST AIRMASS ALOFT
WILL CREATE DRIZZLE OR FREEZING DRIZZLE. EVEN THOUGH MORE MOISTURE
WILL BE AVAILABLE...LITTLE OR NO ICE ACCUMULATION IS EXPECTED.
HOWEVER...A SLIGHTLY STRONGER SYSTEM WITH SLIGHTLY DEEPER MOISTURE
COULD PRODUCE LIGHT ICING ON BRIDGES...OVERPASSES AND OTHER
ELEVATED ROADS. SO...STAY TUNED FOR THE LATEST DEVELOPMENTS ON
THIS WEATHER EVENT. ISENTROPIC LIFT SLOWLY WANES WITH DRIZZLE
ENDING BY LATE FRIDAY EVENING. CLOUD COVER WILL MAKE TEMPERATURES
STRUGGLE TO REACH 40 MOST AREAS TODAY AND FRIDAY. AVERAGE HIGHS
ARE IN THE LOWER TO MID 60S.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
SOUTHWESTERLY WINDS DEVELOP ON SATURDAY AS THE SURFACE HIGH MOVES
AWAY LEADING TO A WARM DAY WITH HIGHS NEAR OR JUST ABOVE AVERAGE.
THE MODELS HAVE BECOME MORE DISAGREEABLE FOR SUNDAY AND MONDAY.
THE GFS BRINGS A WEAK BACKDOOR COLD FRONT INTO OUR AREA SUNDAY AND
LIFTS IT BACK NORTH MONDAY WITH A STRONGER COLD FRONT TUESDAY
WHILE THE ECMWF BRINGS A MODERATELY COLD FRONT THROUGH SUNDAY
NIGHT WITH A STRONGER PUSH OF COLD AIR TUESDAY. BOTH MODELS SHOW
AN UPPER LEVEL TROUGH MOVING ACROSS TEXAS LATE TUESDAY INTO
TUESDAY NIGHT. FOR NOW...WILL SIDE WITH THE GFS ON THE FRONT.
WARM ADVECTION SHOWERS ARE POSSIBLE MONDAY INTO MONDAY NIGHT WITH
A SLIGHTLY BETTER CHANCE OF SHOWERS WITH THE UPPER LEVEL TROUGH
TUESDAY INTO TUESDAY NIGHT. COLD AND DRY AGAIN FOR WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 34 26 41 35 67 / 10 10 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 34 24 39 33 66 / 10 10 20 10 -
NEW BRAUNFELS MUNI AIRPORT 35 27 38 33 68 / 20 10 20 10 -
BURNET MUNI AIRPORT 33 23 39 31 65 / 10 10 20 10 -
DEL RIO INTL AIRPORT 40 30 47 36 71 / 10 - - - -
GEORGETOWN MUNI AIRPORT 34 23 39 32 63 / 10 10 20 10 -
HONDO MUNI AIRPORT 37 28 42 34 70 / 10 10 20 10 -
SAN MARCOS MUNI AIRPORT 35 26 38 33 67 / 20 10 20 10 -
LA GRANGE - FAYETTE REGIONAL 36 29 39 35 63 / 20 10 20 20 10
SAN ANTONIO INTL AIRPORT 35 29 41 35 69 / 20 10 20 10 -
STINSON MUNI AIRPORT 36 30 40 34 69 / 10 10 20 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...25
SYNOPTIC/GRIDS...24
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
942 AM CST THU FEB 6 2014
.UPDATE...
WE HAVE LOWERED TODAY/S HIGH TEMPERATURES BY A FEW DEGREES ACROSS
MOST OF THE REGION. THE LATEST RUC13 AND SREF MODEL DATA SUGGESTS
HIGHS WILL REMAIN IN THE 30S ACROSS MOST AREAS...WITH TEMPS
STRUGGLING TO REACH FREEZING OVER THE HILL COUNTRY. HIGHS ALONG
THE I-35 CORRIDOR WILL STRUGGLE TO REACH THE MID 30S. NO CHANGES
TO THE WINTER WEATHER ADVISORY JUST YET AS THE LATEST RADAR DATA
CONTINUES TO SHOW SOME LIGHT ECHOES ACROSS THE HILL COUNTRY SLOWLY
MOVING INTO THE I-35 CORRIDOR. WE COULD SEE SOME LIGHT SNOW OR
GRAUPEL FROM THIS ACTIVITY. GIVEN THE LIGHT RADAR RETURNS...WOULD
NOT EXPECT ANY SIGNIFICANT ACCUMULATIONS FROM THIS ACTIVITY.
&&
.PREV DISCUSSION... /ISSUED 547 AM CST THU FEB 6 2014/
AVIATION...
VFR CONDITIONS AT I-35 SITES WITH MVFR AT KDRT. EXPECT THIS TREND
TO CONTINUE WITH COLD HIGH PRESSURE IN CONTROL OVER THE REGION.
ALL SLEET AND LIGHT SNOW SHOULD BE OUT OF THE AREA BY 14Z. CLOUDS
SHOULD REMAIN IN THE 4-6 THOUSAND FOOT RANGE THIS AFTERNOON.
CEILINGS WILL LOWER TO 2-4 THOUSAND FEET AFTER 01Z FRIDAY. AFTER
08Z TONIGHT WILL SEE ANOTHER UPPER LEVEL SYSTEM MOVE ACROSS WITH
LOW CHANCES FOR LIGHT FREEZING DRIZZLE. CURRENTLY FEEL THAT ANY
ACCUMULATIONS WOULD BE MINOR. NORTHERLY WINDS WILL DECREASE TO 10
TO 15 KNOTS THIS MORNING AND NEAR 10 KNOTS THIS AFTERNOON AND
OVERNIGHT.
PREV DISCUSSION... /ISSUED 525 AM CST THU FEB 6 2014/
UPDATE...
HAVE ISSUED A WINTER WEATHER ADVISORY FOR A BAND OF SLEET AND SNOW
FROM NORTHERN SAN ANTONIO ACROSS THE NEW BRAUNFELS AND SAN MARCOS
AREAS...THEN EAST TO LA GRANGE AND LEXINGTON. SLEET AND SNOW
ACCUMULATIONS UP TO ONE HALF INCH ARE POSSIBLE. THE BAND WILL MOVE
EAST BY 11 AM.
PREV DISCUSSION... /ISSUED 424 AM CST THU FEB 6 2014/
UPDATE...
ADDED MENTION OF SLEET FOR A BAND FROM HONDO TO SAN ANTONIO TO
BASTROP TO GIDDINGS. A DUSTING MAY BE POSSIBLE WITH THIS BAND.
PREV DISCUSSION... /ISSUED 341 AM CST THU FEB 6 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...
COLD ADVECTION CONTINUES ACROSS SOUTH CENTRAL TEXAS EARLY THIS
MORNING AS AN UPPER LEVEL TROUGH MOVES ACROSS THE BIG BEND REGION.
ISENTROPIC LIFT ASSOCIATED WITH THIS TROUGH WILL GENERATE VERY
LIGHT PRECIPITATION. CURRENT AND FORECAST SOUNDING DATA SHOW THAT
SNOW FLURRIES ARE THE LIKELY PRECIPITATION TYPE. NO ACCUMULATION
IS EXPECTED DUE TO A VERY DRY LOWER LEVEL AIRMASS. THE TROUGH WILL
MOVE NORTHEAST OF OUR AREA BY MIDDAY ENDING THE FLURRIES AS LIFT
ENDS. ANOTHER UPPER LEVEL TROUGH CURRENTLY SEEN APPROACHING THE
CALIFORNIA COAST WILL MOVE ACROSS TEXAS ON FRIDAY. ISENTROPIC LIFT
WILL DEVELOP LATE TONIGHT. A WARMER AND MORE MOIST AIRMASS ALOFT
WILL CREATE DRIZZLE OR FREEZING DRIZZLE. EVEN THOUGH MORE MOISTURE
WILL BE AVAILABLE...LITTLE OR NO ICE ACCUMULATION IS EXPECTED.
HOWEVER...A SLIGHTLY STRONGER SYSTEM WITH SLIGHTLY DEEPER MOISTURE
COULD PRODUCE LIGHT ICING ON BRIDGES...OVERPASSES AND OTHER
ELEVATED ROADS. SO...STAY TUNED FOR THE LATEST DEVELOPMENTS ON
THIS WEATHER EVENT. ISENTROPIC LIFT SLOWLY WANES WITH DRIZZLE
ENDING BY LATE FRIDAY EVENING. CLOUD COVER WILL MAKE TEMPERATURES
STRUGGLE TO REACH 40 MOST AREAS TODAY AND FRIDAY. AVERAGE HIGHS
ARE IN THE LOWER TO MID 60S.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
SOUTHWESTERLY WINDS DEVELOP ON SATURDAY AS THE SURFACE HIGH MOVES
AWAY LEADING TO A WARM DAY WITH HIGHS NEAR OR JUST ABOVE AVERAGE.
THE MODELS HAVE BECOME MORE DISAGREEABLE FOR SUNDAY AND MONDAY.
THE GFS BRINGS A WEAK BACKDOOR COLD FRONT INTO OUR AREA SUNDAY AND
LIFTS IT BACK NORTH MONDAY WITH A STRONGER COLD FRONT TUESDAY
WHILE THE ECMWF BRINGS A MODERATELY COLD FRONT THROUGH SUNDAY
NIGHT WITH A STRONGER PUSH OF COLD AIR TUESDAY. BOTH MODELS SHOW
AN UPPER LEVEL TROUGH MOVING ACROSS TEXAS LATE TUESDAY INTO
TUESDAY NIGHT. FOR NOW...WILL SIDE WITH THE GFS ON THE FRONT.
WARM ADVECTION SHOWERS ARE POSSIBLE MONDAY INTO MONDAY NIGHT WITH
A SLIGHTLY BETTER CHANCE OF SHOWERS WITH THE UPPER LEVEL TROUGH
TUESDAY INTO TUESDAY NIGHT. COLD AND DRY AGAIN FOR WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 36 26 41 35 67 / 10 10 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 36 24 39 33 66 / 10 10 20 10 -
NEW BRAUNFELS MUNI AIRPORT 36 27 38 33 68 / 20 10 20 10 -
BURNET MUNI AIRPORT 34 23 39 31 65 / 10 10 20 10 -
DEL RIO INTL AIRPORT 42 30 47 36 71 / 10 - - - -
GEORGETOWN MUNI AIRPORT 35 23 39 32 63 / 10 10 20 10 -
HONDO MUNI AIRPORT 39 28 42 34 70 / 10 10 20 10 -
SAN MARCOS MUNI AIRPORT 36 26 38 33 67 / 20 10 20 10 -
LA GRANGE - FAYETTE REGIONAL 39 29 39 35 63 / 20 10 20 20 10
SAN ANTONIO INTL AIRPORT 36 29 41 35 69 / 20 10 20 10 -
STINSON MUNI AIRPORT 36 30 40 34 69 / 10 10 20 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 AM CST THIS MORNING FOR THE
FOLLOWING COUNTIES: BASTROP...BEXAR...CALDWELL...COMAL...FAYETTE...
GONZALES...GUADALUPE...HAYS...LEE.
&&
$$
MESOSCALE/AVIATION...25
SYNOPTIC/GRIDS...24
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1138 PM CST WED FEB 5 2014
.AVIATION...
/06Z TAFS/
CONCERNS...MVFR CIGS LATE TONIGHT AND THURSDAY MORNING IN THE
METROPLEX. CHANCE FOR LIGHT SNOW IN THE METROPLEX THURSDAY MORNING.
SOME MVFR CIGS WITH BASES 2000-2500 FEET ARE BEGINNING TO DEVELOP
IN THE METROPLEX. WILL PREVAIL A SCT025 FOR NOW BECOMING BKN025
AROUND 09Z. SOME OF THE MODELS CONTINUE TO INDICATE THAT THE BKN
DECK WILL REMAIN OVER TARRANT COUNTY WITH DALLAS COUNTY REMAINING
FEW-SCT AND WILL WATCH TRENDS OVERNIGHT. KACT IS EXPECTED TO
REMAIN IN VFR CONDITIONS BUT MAY HAVE BRIEF PERIODS OF BKN025
DURING THE NIGHT.
THERE IS STILL A CHANCE FOR LIGHT SNOW MOVING IN FROM THE WEST
THURSDAY MORNING...REACHING THE METROPLEX BETWEEN 14-15Z. SEVERAL
MODELS KEEP THE SNOW WEST OF THE METROPLEX EXCEPT FOR POSSIBLY
KAFW...SO DID NOT FEEL A NEED TO CHANGE THE CURRENT TAF TIMING AND
IMPACTS DUE TO LIGHT SNOW. CONDITIONS ARE EXPECTED TO IMPROVE
AROUND MIDDAY WITH WIND SPEEDS FINALLY DECREASING TO LESS THAN 10
KTS DURING THE AFTERNOON HOURS.
82/JLD
&&
.UPDATE...
CLOUDS AND MOISTURE WILL GRADUALLY INCREASE OVERNIGHT AS A
PRONOUNCED SHORTWAVE OVER NORTHERN MEXICO MOVES EAST INTO WEST-
CENTRAL TEXAS. MOISTURE LEVELS WILL REMAIN LIMITED WITH THIS
SYSTEM...BUT SUFFICIENT FOR LIGHT PRECIPITATION TO DEVELOP OVER
WESTERN COUNTIES OF NORTH TEXAS EARLY THURSDAY MORNING...THEN
SWEEP NORTHEAST ACROSS THE CENTRAL AND NORTHEASTERN COUNTIES LATE
MORNING THROUGH EARLY AFTERNOON. SUB-FREEZING TEMPERATURES AT ALL
ALTITUDES INDICATES THAT PRECIPITATION WILL FALL AS SNOW. THE MOST
RECENT MODEL OUTPUT FROM THIS EVENING REMAINS FAIRLY CONSISTENT
WITH EARLIER RUNS...INDICATING 1-2 INCHES OVER THE WESTERN-MOST
LOCALES...TAPERING OFF TO AROUND A QUARTER OR HALF AN INCH IN THE
DALLAS-FORT WORTH METROPLEX...TO A DUSTING FARTHER EAST. A WINTER
WEATHER ADVISORY WILL REMAIN IN EFFECT FROM 3 AM UNTIL 2 PM
THURSDAY FOR AREAS GENERALLY WEST OF AN EASTLAND TO JACKSBORO TO
BOWIE LINE. PRECIPITATION WILL COME TO AN END THURSDAY AFTERNOON AS
THE SHORTWAVE ACCELERATES EASTWARD INTO THE MISSISSIPPI VALLEY. AT
THIS TIME...IT APPEARS THAT MEASURABLE SNOWFALL WILL BE LIMITED TO
AREAS GENERALLY ALONG AND NORTHWEST OF A LINE FROM PARIS TO
COMANCHE...WHILE AREAS FARTHER SOUTH AND EAST MAY BE TOO FAR REMOVED
FROM THE UPPER LEVEL FEATURE TO RECEIVE MEASURABLE PRECIPITATION.
EITHER WAY...BITTER COLD CONDITIONS WILL BE EXPERIENCED AREA-WIDE
THROUGH TOMORROW AS TEMPERATURES PLUMMET INTO THE TEENS. A WIND CHILL
ADVISORY WILL REMAIN IN PLACE OVERNIGHT FOR AREAS ALONG AND NORTH
OF A LINE FROM CISCO TO WEATHERFORD TO MCKINNEY TO BONHAM. WE
WILL KEEP AN EYE ON PRECIPITATION TRENDS AS ACTIVITY UNFOLDS LATER
TONIGHT...AND ADJUST THE AREAS OF THE WINTER WEATHER ADVISORY IF
NEEDED. AT THIS TIME...THE FORECAST REMAINS IN GREAT SHAPE WITH NO
SIGNIFICANT UPDATES NEEDED.
30
&&
.PREV DISCUSSION... /ISSUED 346 PM CST WED FEB 5 2014/
VERY PROGRESSIVE UPPER PATTERN WILL KEEP NORTH TEXAS COLD WITH
SEVERAL CHANCES FOR AT LEAST LIGHT PRECIPITATION OVER THE UPCOMING
WEEK. WITH TEMPERATURES NOT EXPECTED TO MAKE IT ABOVE FREEZING
UNTIL SOMETIME FRIDAY...WINTRY PRECIPITATION REMAINS IN THE
FORECAST.
WATER VAPOR IMAGERY SHOWS STRONG SHORTWAVE NOW MAKING ITS WAY
ACROSS NORTHWEST MEXICO. RUC ANALYSIS OF THE DYNAMIC TROPOPAUSE
HAS CONSISTENTLY SUGGESTED THAT THIS FEATURE IS STRONGER THAN MOST
OF THE OTHER OPERATIONAL MODEL GUIDANCE IS INDICATING. THIS IS SUPPORTED
BY THE IMAGERY ITSELF WHICH SHOWS A COMPACT POTENT VORTEX DIGGING
ACROSS THE MEXICAN STATE OF SONORA. AS IT MOVES INTO THE BIG BEND
REGION LATER TONIGHT...SATURATION WILL TAKE PLACE FROM BOTH THE
TOP DOWN AND FROM LOW LEVEL WARM MOIST ADVECTION AS 850MB FLOW
VEERS IN RESPONSE TO APPROACHING SHORTWAVE. THE THERMAL PROFILE
ACROSS NORTH TEXAS WILL BE SUFFICIENTLY COLD TO SUPPORT ALL SNOW
SO PRECIP TYPE IS REALLY NOT IN QUESTION THIS TIME AROUND.
CROSS SECTION ANALYSIS FROM SOUTHWEST OKLAHOMA INTO NORTH CENTRAL
TEXAS INDICATES A DEEP SATURATED LAYER BY THURSDAY MORNING WITH
CONDITIONAL SYMMETRIC INSTABILITY PRESENT. AS FORCING INCREASES
LATE TONIGHT...AREAS OF SNOW ARE EXPECTED TO DEVELOP MAINLY ACROSS
THE WESTERN COUNTIES. SOME BANDING OF THE PRECIPITATION IS
POSSIBLE GIVEN THE PRESENCE OF INSTABILITY MENTIONED EARLIER AND
THIS HAS EVEN BEEN INDICATED IN THE LAST COUPLE OF RUNS OF THE 3KM
TTU WRF. WHILE QPF AMOUNTS ARE GENERALLY LIGHT ACROSS THE AREA...THE
COLD TEMPERATURES SHOULD SUPPORT SNOWFALL RATIOS OF GREATER THAN
10 TO 1. THIS ISNT TYPICAL FOR NORTH TEXAS AS WE USUALLY WIND UP
DEALING WITH HEAVY WET SNOW. BASED ON THE LATEST DATA...WE THINK 1
TO 2 INCHES OF SNOW WILL BE POSSIBLE ACROSS THE WESTERN COUNTIES
WITH LIGHTER AMOUNTS FARTHER EAST INTO THE METROPLEX. ALL OF THE
ACTIVITY SHOULD END QUICKLY BY MIDDAY OR SHORTLY THEREAFTER. A
WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR THE FAR WESTERN
COUNTIES WHERE GREATEST ACCUMULATIONS ARE EXPECTED. IN
ADDITION...THE WIND CHILL ADVISORY WILL REMAIN UNCHANGED AS TEMPS
ARE EXPECTED TO FALL INTO THE LOW TO MID TEENS WITH GUSTY NORTH WINDS.
AS SOON AS THIS SYSTEM DEPARTS...ANOTHER IS QUICKLY ON ITS HEELS
FOR FRIDAY AND THIS COULD ACTUALLY BE THE DAY OF MORE SIGNIFICANT
WINTER WEATHER IMPACTS. COLD TEMPERATURES WILL REMAIN ENTRENCHED
ACROSS THE REGION WITH MOST AREAS IN THE LOW 20S EARLY FRIDAY
MORNING. SURFACE FLOW WILL WEAKEN AND VEER TO THE EAST DURING THE
DAY FRIDAY...BUT SOUTHERLY 850MB FLOW WILL BE ESTABLISHED BY THIS
TIME. LOW LEVEL MOISTURE AND WARM ADVECTION WILL BE SUFFICIENT FOR
LIGHT PRECIPITATION TO DEVELOP DURING THE DAY FRIDAY. ANALYSIS OF
FORECAST SOUNDINGS INDICATE A COUPLE OF SCENARIOS POSSIBLY PLAYING OUT.
THE LEAST FAVORABLE AT THIS TIME WOULD BE FOR A QUICK RETURN OF
MOISTURE AND WIDESPREAD SNOW TO DEVELOP DURING THE DAY. THIS SEEMS
UNLIKELY GIVEN THE LACK OF MORE SIGNIFICANT MOISTURE ALOFT...AND
MORE IMPORTANTLY LACK OF MOISTURE IN THE SNOW DENDRITIC GROWTH
ZONE. WHILE THERE WILL BE SUFFICIENT MOISTURE DOWN LOW...IT IS LIKELY
TO BE IN THE FORM OF SUPER COOLED WATER DROPLETS...WHICH LEADS TO
THE MORE LIKELY SCENARIO OF WIDESPREAD VERY LIGHT FREEZING RAIN OR
FREEZING DRIZZLE. WITH TEMPERATURES IN THE LOW TO MID 20S AND
GROUND TEMPERATURES SUFFICIENTLY COLD...ICE WOULD LIKELY RAPIDLY
DEVELOP. FOR NOW...CONFIDENCE IS LOW IN ANY PARTICULAR SOLUTION
BUT WILL HAVE 20 POPS FOR LIGHT FREEZING RAIN/DRIZZLE ON FRIDAY.
BEYOND FRIDAY...MODELS DIFFER WITH FRONTAL TIMING ON MONDAY WITH
THE ECMWF BRINGING A FRONT THROUGH AND GFS HOLDING OFF UNTIL
TUESDAY. THIS FORECAST PACKAGE WILL COMPROMISE BETWEEN THE TWO AND
SHOW INCREASING RAIN CHANCES FOR MON/TUE TIMEFRAME.
DUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 17 27 20 35 28 / 10 50 5 20 10
WACO, TX 20 34 22 38 29 / 10 20 5 20 10
PARIS, TX 19 27 22 37 27 / 10 50 5 20 10
DENTON, TX 17 25 17 35 26 / 10 70 5 20 10
MCKINNEY, TX 16 27 18 34 26 / 10 50 5 20 10
DALLAS, TX 18 29 21 36 28 / 10 50 5 20 10
TERRELL, TX 20 30 21 37 28 / 10 30 5 20 10
CORSICANA, TX 21 35 25 38 30 / 10 20 5 20 10
TEMPLE, TX 22 35 22 39 31 / 10 10 5 20 10
MINERAL WELLS, TX 16 26 18 35 25 / 20 70 5 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 AM TO 2 PM CST THURSDAY FOR
TXZ091-100-101-115-116-129.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR
TXZ091>094-100>104-115>117-129-130.
&&
$$
82/30
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1004 PM EST FRI FEB 7 2014
.SYNOPSIS...
HIGH PRESSURE DEPARTS TONIGHT. AN AREA OF LOW PRESSURE WILL
DEVELOP OFF THE SOUTHEAST COAST THROUGH SATURDAY...WITH AN UPPER
LEVEL DISTURBANCE ALSO CUTTING ACROSS VIRGINIA AND NORTH CAROLINA. A
REINFORCING SHOT OF COLDER AIR ARRIVES SUNDAY NIGHT AND
MONDAY...WITH ANOTHER SYSTEM POTENTIALLY MOVING ALONG THE LEADING
EDGE OF COLDER AIR...INTO WESTERN NORTH CAROLINA AND SOUTHWESTERN
VIRGINIA ON MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 950 PM EST FRIDAY...
MID AND HIGH CLOUDS CONTINUED TO FILL IN FROM THE SOUTHWEST THIS
EVENING. 00Z SOUNDINGS SHOWED THERE IS STILL SOME DRY AIR TO
OVERCOME BEFORE PRECIPITATION BEGINS. 18Z WRF...LATEST RUC AND
LATEST HRRR DO NOT HAVE THE SNOW BEGINNING IN THE FAR WESTERN
COUNTY WARNING AREA UNTIL AFTER 08Z/3AM AND SPREADING AT LEAST AS
FAR EAST AS THE ALLEGHANY HIGHLANDS AND NEW RIVER VALLEY BY 7AM.
ANY SNOW ACCUMULATION BEFORE 7AM WILL BE LESS THAN ONE INCH.
HAVE LOWERED MINIMUM TEMPERATURES IN SEVERAL LOCATIONS BASED ON
9PM OBSERVATIONS AND GRIDDED LAMP GUIDANCE.
AS OF 304 PM EST FRIDAY...
MODELS RATHER CONSISTENT FROM LAST NIGHT`S RUN WITH REGARDS TO LIGHT
SNOW EVENT LATE TONIGHT AND PART OF SATURDAY MORNING. SOME CLOUDS
REMAINING THIS AFTERNOON HAS SERVED TO INCUBATE LOW LEVEL MOISTURE
AND NOT LET DEWPOINT DEPRESSIONS BECOME TOO LARGE. THIS HAS
IMPLICATIONS WITH REGARDS TO HOW MUCH VIRGA/QPF IS NEEDED TO
SATURATE THE LEVELS LATE TONIGHT...AND HOW MUCH PRECIP ACTUALLY
MAKES IT TO THE GROUND. THE HIGHEST ELEVATIONS WILL BE MORE MOIST
SO THIS WILL NOT BE MUCH OF AN ISSUE. NONETHELESS...WITH ONLY
BETWEEN 0.02" AND 0.10" OF LIQUID FORECAST...IT MAY ONLY MEAN THE
DIFFERENCE BETWEEN A TRACE OF ACCUM AND A HALF INCH MOST SPOTS.
GROUND IS NOT SUPER COLD SO THAT MOST OF THE SNOW MAY IN FACT MELT
ALONG THE ROADS...EXCEPT ACROSS THE HIGHER ELEVATIONS...RESERVING
MOST LIGHT ACCUMS TO THE GRASS.
STILL THINK THERE WILL BE A SPLIT BETWEEN THE MOISTURE THAT IS NW
OF THE COASTAL LOW...AND THE SNOW THAT IS PRODUCED FROM THE UPPER
LEVEL SYSTEM. COULD SEE PARTS OF THE NEW RIVER VALLEY AND SW VA
FALLING IN BETWEEN THESE TWO AREAS OF PRECIP...AND JUST ENDING UP
WITH FLURRIES. THAT AREA IS TOUGH TO PINPOINT...SO WE WILL JUST GO
WITH A FEW TENTHS JUST ABOUT EVERYWHERE.
MORE RECENTLY THE MODELS HAVE BEEN TARGETING THE VA
PIEDMONT/SOUTHERN SHENANDOAH REGION FOR JUST UNDER A TENTH OF
LIQUID TOMORROW MORNING...AND THIS COULD PUT DOWN A HALF INCH TO
AN INCH FOR THE NORTHEASTERN QUADRANT OF THE CWA. THERE ARE SOME
TOTAL 2 INCH AMOUNTS ACROSS THE NORTHERN HALF OF THE CWA ABOVE
3000 FEET.
THE SYSTEM DEPARTS QUICKLY AND WITH WIDESPREAD SINKING MOTION
SATURDAY AFTERNOON SOME CLEARING IS LIKELY...AND HIGH TEMPS WILL
BE MET LATE AFTERNOON. WITH PRECIP AROUND SATURDAY MORNING...WENT
WITH A SLOWER RISE IN TEMPS THAN DIURNAL WOULD SUGGEST FOR THAT
PART OF THE DAY. CLOUDS WILL REMAIN ACROSS SE WEST VA THROUGH
AFTERNOON WITH UPSLOPE FLOW GETTING UNDERWAY LATE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EST FRIDAY...
WITH START SATURDAY NIGHT OFF WITH A WEAK SYSTEM PASSING ACROSS THE
GREAT LAKES. THE SOUTHWESTERLY WINDS AHEAD OF THIS SYSTEM MAY DRAW
ENOUGH MOISTURE INTO THE MOUNTAINS FOR SOME UPSLOPE SNOW SHOWERS...
HOWEVER SOUTHWESTERLY FLOW IS NOT THE IDEAL WIND DIRECTION TO
PRODUCE WIDESPREAD ACCUMULATIONS AS THE FLOW RUNS PARALLEL TO THE
RIDGE LINES. MAY SEE BETTER ACCUMULATIONS AFTER SUNRISE SUNDAY AS
WIND FLOW SHIFTS MORE WESTERLY. EXPECT THESE SNOW SHOWERS TO TAPER
OFF SATURDAY AFTERNOON...WITH ABOUT AN INCH ACCUMULATION ACROSS
WESTERN GREENBRIER COUNTY...TAPERING DOWN TO A FEW TENTHS OF AN INCH
IN THE EASTERN HALF OF THE COUNTY INTO THE ALLEGHANY HIGHLANDS.
IT DOES NOT TAKE LONG FOR WINDS TO BACK SOUTHWESTERLY AGAIN SUNDAY
AFTERNOON AS OUR NEXT SYSTEM APPROACHES. BELIEVE WE WILL SEE A SHORT
LULL IN PRECIPITATION FOR OUR AREA DURING THE AFTERNOON...WHERE
DECREASING CLOUD COVER WILL HELP AFTERNOON TEMPERATURES WARM INTO
THE MID 30S ACROSS SOUTHEAST WEST VIRGINIA...UP TO NEAR 50 ACROSS
THE SOUTHSIDE.
SUNDAY EVENING IS THE POINT WHERE THE MODELS DEVELOP TIMING
DIFFERENCES CONCERNING OUR NEXT COLD FRONT APPROACHING FROM THE
WEST. THE GFS FORECAST MODEL IS FASTEST WITH THE FRONT...BRINGING IT
THROUGH OUR AREA SUNDAY EVENING...WHILE THE NAM AND THE ECMWF HANG
THE FRONT FURTHER NORTH...AND DRAG THE FRONT MORE SLOWLY ACROSS OUR
AREA LATE SUNDAY NIGHT/EARLY MONDAY. CONSIDERING THE NEARLY STRAIGHT
WEST TO EAST UPPER LEVEL FLOW...MORE INCLINED TO FOLLOW THE
NAM/ECMWF GUIDANCE. THE SLOW PASSAGE OF THE FRONT THROUGH OUR AREA
THROUGH MONDAY AFTERNOON ALSO OPENS OUR AREA FOR A HIGHER CHANCE OF
LIGHT SNOW NORTH OF HIGHWAY 460 MONDAY AFTERNOON...WITH A RAIN SNOW
MIX FURTHER SOUTH. BELIEVE THE FRONT WILL STALL ACROSS THE CAROLINAS
MONDAY EVENING...AND WILL THEREFORE KEEP A HIGHER CHANCE OF
PRECIPITATION IN THE FORECAST HEADING INTO THE OVERNIGHT HOURS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 325 PM EST FRIDAY...
HIGH PRESSURE IN THE OHIO VALLEY TUESDAY MORNING WILL BUILD
NORTHEAST TUESDAY AFTERNOON REACHING SOUTHERN NEW ENGLAND BY
WEDNESDAY MORNING. AN AREA OF LOW PRESSURE WILL DEVELOP IN THE GULF
TUESDAY AND LIFT NORTHEAST TUESDAY NIGHT INTO WEDNESDAY. THE GFS HAS
A FURTHER SOUTH POSITION AND TRACK WITH THE LOW CENTER COMPARED TO
THE ECMWF. THE 00Z ECMWF STILL DEVELOPS A COASTAL LOW OFF THE SOUTH
CAROLINA COAST WEDNESDAY EVENING AND LIFTS NORTHWARD ALONG THE
ATLANTIC COAST THURSDAY. IN CONTRAST...THE GFS PUSHES MOST OF THE
MOISTURE OFF INTO THE ATLANTIC OCEAN. THE ECMWF IS INDICATING THE
POTENTIAL FOR MORE ACCUMULATING SNOWS FROM WEDNESDAY INTO
THURSDAY. THE GFS HAS LIGHTER SNOW ACCUMULATIONS WITH THIS STORM.
LEANED POPS TOWARDS HPCGUIDE SHAPED BY PREFERRED AVERAGE OF THE
GLOBAL ENSEMBLE MEANS. KEPT THE HIGHEST POPS WEDNESDAY AFTERNOON
INTO THURSDAY. TOO MUCH VARIABILITY IN THE MODELS WITH THIS WINTER
STORM TO WORK OUT EXACT DETAILS AT THIS POINT.
THURSDAY INTO THURSDAY NIGHT...COASTAL LOW AND ITS ASSOCIATED COLD
FRONT WILL CONTINUE TO MOVE OUT INTO THE ATLANTIC OCEAN.
MEANWHILE...LOW PRESSURE WITH A TRAILING COLD FRONT WILL DROP
SOUTHEAST ACROSS THE GREAT LAKES. ON THE FRIDAY...THE COLD FRONT
WILL CONTINUE TO MOVE EAST AS HIGH PRESSURE BUILDS OVER THE MIDWEST.
TEMPERATURES WILL START COLD AND SLOWLY MODERATE TOWARDS THE END OF
THE WEEK. THEN...A COOLING TEND IS EXPECTED FOR THE END OF THE WEEK
INTO EARLY NEXT WEEK.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
AS OF 645 PM EST FRIDAY...
REGIONAL OBSERVATIONS SHOWED LOWER CEILINGS APPROACHING FROM THE
TENNESSEE VALLEY. CEILINGS ARE EXPECTED TO REMAIN VFR UNTIL AFTER
09Z AT KBLF AND KLWB.
INITIAL ECHOES FROM AN UPPER LEVEL DISTURBANCE ARRIVING MAY BE
VIRGA AFTER MIDNIGHT...BUT FAIR CHANCE EXISTS FOR IFR CIG/VIS IN
-SN THAT MOVES TO LWB/BLF JUST BEFORE SUNRISE. QPF IS MOST
CONCENTRATED OVER LWB...SO THEY HAVE THE BEST CHANCE OF IFR
CIG/VIS AND POSSIBLY MODERATE SNOW.
LIGHT SNOW WILL SPREAD EAST THROUGH THE MORNING...BUT SOME OF IT
MAY DRY UP AND FAIL TO IMPACT BCB/ROA/LYH GREATLY. LOW CONFIDENCE
OF A FEW HOURS OF MVFR CEILINGS AT THESE SITES. DAN WILL BE
NEARER TO THE PRECIP SHIELD ASSOCIATED WITH A COASTAL
SYSTEM...AND COULD HAVE MORE HOURS OF PRECIP THAN ALL OTHER SITES.
ALTHOUGH BEGINNING AS SNOW...BOUNDARY LAYER TEMPS WILL BE MARGINAL
AND WARMING TO ALLOW FOR RAIN MIXING BY NOON AT DAN.
FOR ALL SITES HIGH CONFIDENCE THAT THIS WILL BE A MOSTLY MORNING
EVENT WITH SOME CLEARING SATURDAY AFTERNOON EXCEPT LWB. CLOUDS
INCREASE AGAIN SATURDAY NIGHT AHEAD OF AN UPPER LEVEL DISTURBANCE
WHICH WILL REMAIN MOSTLY OVER THE OHIO VALLEY...BUT POSSIBLY
SPREADING SOME MVFR CIGS INTO LWB/BLF BY DAWN SUNDAY.
EXTENDED AVIATION DISCUSSION...
FOR SUNDAY...AN UPPER LEVEL DISTURBANCE AND COLD FRONT WILL
BRING SNOW SHOWERS AND LIKELY MVFR CIGS WITH POSSIBLE IFR CIGS
LWB/BLF. DOWNSLOPE WIND FLOW SHOULD RESULT IN CLEARING EAST OF
THE MTNS WITH VFR BUT BREEZY CONDITIONS. GUIDANCE RATHER DIVERGENT
ON HOW A WAVE OVER THE ARKLATEX INTERACTS WITH THE FRONT
NEARBY OVER THE MIDDLE ATLANTIC/SOUTHEAST...AND HOW FAR NORTH IT
SPREADS WINTER PRECIP INTO OUR REGION SUNDAY NIGHT AND MONDAY.
THERE IS A CHANCE FOR WIDESPREAD MVFR AND POSSIBLE IFR IF THIS
SYSTEM MOVES ALONG THE VA/NC BORDER.
ALTHOUGH SURFACE HIGH PRESSURE BRINGS TRANQUIL BUT COLD WEATHER
BACK FOR TUESDAY...IT`S EVENTUAL POSITION OVER SE CANADA OR NEW
ENGLAND MAY PROVIDE A COLD DOME FOR WHICH GULF OF MEXICO MOISTURE
IS ABLE TO OVERSPREAD NEXT WEDNESDAY....WITH AT LEAST A CHANCE FOR
WIDESPREAD IFR CONDS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KM/RAB
NEAR TERM...AMS/KM
SHORT TERM...NF
LONG TERM...KK
AVIATION...AMS/KM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1011 PM CST WED FEB 5 2014
.UPDATE...
ISSUED AT 807 PM CST WED FEB 5 2014
CLOUDS ARE DISSIPATING AND EXITING THE FORECAST AREA MUCH FASTER
THAN PREVIOUSLY FORECAST. HAVE BEEN UPDATING TRENDS OVER THE PAST
FEW HOURS TO ACCOUNT TO THE CLEARING TREND SEEN ON 11-3.9UM
IMAGERY AND OBSERVATIONS. APPEARS DIURNAL HEATING HAD A BIG
INFLUENCE ON THE CLOUD COVER THIS AFTERNOON...ESPECIALLY AROUND
AND WEST OF I-35 WHERE THOSE CLOUDS ARE NOW DISSIPATED. AS FAR AS
THE CLOUDS WRAPPING AROUND THE VORT CENTER IN NORTHEAST SOUTH
DAKOTA...THESE ARE MOVING VERY LITTLE. THEREFORE...THEY MAY NOT
EVEN GET HERE UNTIL WELL AFTER SUNRISE...IF AT ALL GIVEN THE TRACK
OF THE VORT EXPECTED TO STAY MOSTLY NORTH OF THE FORECAST AREA.
MUCH OF THE FLURRY ACTIVITY HAS FOLLOWED THE CLOUD TRENDS...
DISSIPATING QUICKLY BETWEEN 4-6 PM. ONLY AREA THAT STILL HAS
FLURRIES MENTIONED IS TAYLOR/CLARK COUNTIES. EVEN HERE...THE
FLURRIES MAY END BY MIDNIGHT.
WITH CLEARER SKIES TONIGHT...ATTENTION TURNS TO TEMPERATURES.
05.18Z NAM AND 05.23Z RAP INDICATE MUCH COLDER LOWS THAN
FORECAST...PARTICULARLY SOUTH OF I-90. COMPARING THEIR 1-3 HOURLY
FORECAST OUTPUT...THEY DO SEEM TO BE A BIT TOO COLD. HOWEVER...THE
IDEA OF A COLDER NIGHT SEEMS REASONABLE GIVEN THE CLEARER SKIES.
LOWERED LOWS A FEW DEGREES SOUTH OF INTERSTATE 90...AS WELL AS THE
BLACK RIVER FALLS/SPARTA AREA. NEEDLESS TO SAY THE COLDER
TEMPERATURES EASILY SUPPORTS THE GOING WIND CHILL ADVISORY.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 215 PM CST WED FEB 5 2014
FLURRIES TONIGHT AND BITTER COLD WIND CHILLS TONIGHT INTO THURSDAY
MORNING WILL BE THE MAIN FOCUS IN THE SHORT TERM.
WATER VAPOR IMAGERY SHOWING AN ELONGATED MID-LEVEL TROUGH EXTENDING
FROM WESTERN QUEBEC THROUGH SOUTHERN ONTARIO INTO THE NORTHERN
PLAINS. VERY LIGHT/NON-MEASURABLE SNOW CONTINUED TO LINGER ACROSS
THE FORECAST AREA UNDER THIS TROUGH/GENERAL CYCLONIC FLOW.
OTHERWISE...SKIES WERE CLOUDY ACROSS THE AREA WITH TEMPERATURES
BEING HELD IN CHECK IN THE SINGLE DIGITS AND TEENS ABOVE ZERO.
OF NOTE ON THE WATER VAPOR EMBEDDED WITHIN THE LONG WAVE TROUGH WAS A
VORTICITY MAXIMUM OVER EASTERN ND. THIS WAVE WILL WEAKEN AS IT MOVES
SOUTHEAST INTO THE AREA TONIGHT. NONETHELESS...MODELS SHOW A WING OF
WEAK WIND OF 700-300MB PV-ADVECTION MOVING THROUGH THE AREA AND IS
EXPECTED TO KEEP FLURRY ACTIVITY GOING THROUGH THE NIGHT. DESPITE
CLOUD COVER...EXPECTING TEMPERATURES TONIGHT INTO EARLY THURSDAY
MORNING TO FALL INTO -5 TO -11F RANGE. THESE TEMPERATURES COMBINED
WITH WINDS IN THE 6 TO 12 MPH RANGE WILL PRODUCE WIND CHILLS IN THE
-15 TO -30F RANGE. AS SUCH...A WIND CHILL ADVISORY REMAINS IN EFFECT
TONIGHT THROUGH NOON THURSDAY.
WILL LIKELY NEED ANOTHER WIND CHILL ADVISORY HEADLINE FOR THURSDAY
NIGHT INTO FRIDAY MORNING AS WELL. LOOK FOR TEMPERATURES TO FALL
INTO THE -5 TO -15F RANGE AND WEST/SOUTHWEST WINDS BLOWING AROUND 7-
15 MPH ON THE BACKSIDE OF HIGH PRESSURE SLIDING SOUTH OF THE AREA.
THIS IS EXPECTED TO PRODUCE BITTER COLD WIND CHILL VALUES IN THE -15
TO -30F RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 215 PM CST WED FEB 5 2014
FRIDAY THROUGH SATURDAY NIGHT:
AFTER THE BITTER COLD WIND CHILLS THROUGH FRIDAY MORNING...ATTENTION
THEN TURNS TO A FAIRLY VIGOROUS MID-LEVEL TROUGH ROTATING OUT OF THE
PLAINS AND ACROSS THE AREA FRIDAY NIGHT/SATURDAY. THIS SIGNAL HAS
BEEN GETTING MORE CONSISTENT BETWEEN THE MODELS AND FROM RUN-TO-
RUN. FURTHER ANALYSIS WITH THE NAM/GFS SHOWS DECENT 700-300MB PV-
ADVECTION ASSOCIATED WITH THE WAVE ALONG WITH FAIRLY STRONG 275K
ISENTROPIC LIFT INTO THE REGION FROM LATE FRIDAY NIGHT/AFTER
MIDNIGHT...THROUGH SATURDAY. BASED ON THIS...HAVE PUSHED POPS INTO
THE LIKELY CATEGORY CENTERED ON DURING THE DAY SATURDAY. RIGHT
NOW...IT APPEARS A BROAD AREA OF 1.5-2.5 INCHES IS EXPECTED WITH THE
HEAVIEST AMOUNTS ALONG AND SOUTH OF I-90. 12Z MODELS HAVE THIS WAVE
PUSHING EAST OF THE AREA SATURDAY EVENING WITH PERHAPS SOME
LINGERING LIGHT SNOW ACROSS PORTIONS OF NORTHEAST IA INTO CENTRAL
WI. TEMPERATURE-WISE...HIGHS SATURDAY EXPECTED TO TOP OFF IN THE
TEENS WITH LOWS SATURDAY NIGHT DIPPING BACK DOWN INTO THE SINGLE
DIGITS EITHER SIDE OF ZERO.
SUNDAY THROUGH WEDNESDAY:
12Z ECMWF/GFS STARTING TO INDICATE SOME WEAKENING/BREAKING DOWN OF
THE RIDGE OFF THE WEST COAST FOR SUNDAY THROUGH WEDNESDAY. MODIFIED
WEST/NORTHWEST FLOW ALOFT STEERS PRECIPITATING PRECIPITATION WAVES
SOUTH OF THE AREA WITH OUR AREA REMAINING DRY THROUGH THE PERIOD.
ALSO...LOOKS LIKE SOME MODERATION IN TEMPERATURE AS WELL AS ARCTIC
AIR IS HELD NORTH OF THE CANADIAN BORDER WITH RETREAT OF THE POLAR
VORTEX. LOOKING FOR HIGHS STARTING OFF SUNDAY IN THE SINGLE
DIGITS/TEENS ABOVE ZERO...MODERATING SLOWLY INTO THE UPPER
TEENS/MIDDLE 20S BY WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1011 PM CST WED FEB 5 2014
SKIES HAVE CLEARED OUT AT THE TAF SITES RESULTING FROM THE LOSS OF
DAYTIME HEATING AND DRIER AIR FLOWING IN FROM THE WEST.
ANTICIPATING VFR CONDITIONS TO CONTINUE THROUGH THURSDAY NIGHT AS
A FLOW OF DRY...ARCTIC AIR PERSISTS. THERE COULD BE SOME SCATTERED
DAYTIME STRATOCUMULUS WITH MVFR CEILINGS AT RST...BUT BELIEVE
ENOUGH DRY AIR SHOULD BE PRESENT TO PRECLUDE THE CLOUDS FROM GOING
TO BROKEN. A NORTHWEST TO WEST 5-15 KT BREEZE WILL PERSIST AS WELL
AT BOTH TAF SITES...WITH THE STRONGEST WINDS OCCURRING DURING THE
MID TO LATE AFTERNOON HOURS AT THE TIME OF PEAK HEATING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR MNZ086-087-094-
095.
WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR MNZ079-088-096.
IA...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR IAZ008>010-018-
019-029.
WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR IAZ011-030.
&&
$$
UPDATE...AJ
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...AJ
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1245 AM EST SAT FEB 8 2014
.UPDATE...
HIGH PRESSURE CONTINUES AT THE SURFACE TONIGHT. HOWEVER...AN UPPER
LEVEL DISTURBANCE WILL MOVE INTO THE DEEP SOUTH OVERNIGHT AND
EARLY SATURDAY. PRECIPITATION HAS ALREADY DEVELOPED ACROSS THE
ARKLATEX...AND WILL GRADUALLY SPREAD EASTWARD TOWARDS MORNING. 00Z
NAM SOUNDINGS DO MOISTEN UP THE MID AND UPPER COLUMN...BUT KEEP
THE LOWER LEVELS DRY. HOWEVER...LOW DEWPOINT DEPRESSIONS ALREADY
EXIST IN THE SOUTH. SO...THINK BEST CHANCES OF PRECIP WILL REMAIN
JUST SOUTH OF THE ATL METRO. THE LATEST RUNS OF THE HRRR ALSO KEEP
THE PRECIP FURTHER SOUTH.
NO CHANGES TO POPS/TEMPS NEEDED. THE FORECAST LOOKS ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 633 PM EST FRI FEB 7 2014/
PREV DISCUSSION... /ISSUED 330 PM EST FRI FEB 7 2014/
.PATCHY BLACK ICE POSSIBLE FOR PORTIONS OF NORTH GEORGIA DUE TO
LIGHT RAIN AND SNOW MIX TONIGHT INTO EARLY SATURDAY...
SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
MAIN CONCERN FOR THE SHORT TERM IS THE OVERNIGHT PERIOD TONIGHT AS A
DISTURBANCE MOVES ACROSS THE DEEP SOUTH. OVERALL MODELS CONTINUE TO
SUGGEST THAT THE BEST MOISTURE WILL BE ACROSS CENTRAL GEORGIA...AND
SO HAVE CONTINUED WITH THE OVERALL FORECAST TREND OF KEEPING THE
GREATER RAIN CHANCES AND HIGHEST QPF ACROSS THAT AREA. MODELS SHOW
THAT LIGHT RAIN WILL MOVE IN FROM THE SOUTHWEST INTO WESTERN GEORGIA
AROUND MIDNIGHT...AND WILL EXIT THE MAJORITY OF THE FORECAST AREA
8-9AM SATURDAY WITH THE REMAINDER OF THE FORECAST AREA RAIN-FREE BY
THE AFTERNOON. DRY MODEL SOUNDINGS SUGGEST THAT INITIALLY THE
PRECIPITATION WILL BE VIRGA...AND THAT AS THE ATMOSPHERIC COLUMN
MOISTENS...WILL GRADUALLY SEE PRECIP MAKING IT TO THE SURFACE. CLOUD
COVER WILL KEEP TEMPERATURES FROM DROPPING SIGNIFICANTLY...BUT STILL
EXPECT PORTIONS OF NORTH AND WESTERN GEORGIA TO DROP TO NEAR
FREEZING OR SLIGHTLY BELOW. THERE IS A POSSIBILITY OF LIGHT RAIN
MIXING WITH LIGHT SNOW...BUT AS PREVIOUSLY MENTIONED...THE AREAS
THAT HAVE A TEMPERATURE PROFILE WOULD SUPPORT WINTER PRECIPITATION
ARE NOT THE AREAS THAT HAVE THE BEST MOISTURE. AT THIS TIME...DO NOT
EXPECT ANY ACCUMULATIONS.
IF PRECIPITATION IS ENOUGH TO WET SURFACES ACROSS FAR NORTH
GEORGIA...WHERE LOWS WILL BE AT OR BELOW FREEZING...VERY PATCHY
BLACK ICE WILL BE A CONCERN. ADDITIONAL INFORMATION ON POTENTIAL
IMPACTS CAN BE FOUND IN THE LATEST SPECIAL WEATHER STATEMENT
/SPSFFC/.
CLEARING CONDITIONS ARE EXPECTED THROUGH THE SHORT TERM. HAVE
GENERALLY GONE WITH A MODEL BLEND FOR THE TEMPERATURES...WITH MID
50S TO LOW 60S FOR HIGHS SATURDAY...AND SIMILAR LOW TEMPERATURES
AGAIN SUNDAY MORNING.
31
LONG TERM /SUNDAY THROUGH FRIDAY/...
ONLY MINOR ADJUSTMENTS MADE TO PREVIOUS FORECAST AS IT LOOKS TO BE
LARGELY ON TRACK. SOME INDICATION FOR LIGHT SNOW POTENTIAL IN
PORTIONS OF NORTH GEORGIA MONDAY NIGHT BUT WILL MONITOR FOR
CONSISTENCY TO INCLUDE IN FUTURE UPDATES. PREVIOUS DISCUSSION
FOLLOWS...
BAKER
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
/ISSUED AT 350 AM EST FRI FEB 7 2014/
NO EASY FORECASTING FOR THE LONG TERM AS MODEL DIFFERENCES AND COLD
OVERNIGHT TEMPERATURES OVER N GA MAKE PRECIP TYPE DIFFICULT TO
FORECAST.
MODELS CONSISTENT MOVING A SHORT WAVE ACROSS THE AREA SATURDAY NIGHT
WITH MINIMAL MOISTURE ASSOCIATED BUT COULD CAUSE SOME SPRINKLES OR
FLURRIES OVER MAINLY N GA.
SUNDAY LOOKS DRY HOWEVER THE EUROPEAN DOES BRING IN SOME MOISTURE
ACROSS N GA ASSOCIATED WITH A SHORT WAVE WHILE THE GFS IS DRY. A
WEAK BACK DOOR COLD FRONT WILL MOVE TO N GA AS WELL.
EUROPEAN WETTER ON MONDAY SPREADING MOISTURE AND PRECIP CHANCES
ACROSS THE AREA WHILE THE GFS IS DRY WITH MOISTURE MOVING ACROSS THE
N. FOR NOW KEPT SMALL RAIN CHANCES ACROSS THE N. BOTH MODELS
INDICATING MOISTURE ACROSS THE AREA THROUGH TUESDAY WITH THE GFS NOW
WETTER. OVERNIGHT TEMPERATURES MONDAY NIGHT COULD CAUSE A RAIN
SNOW OR EVEN SLEET MIX. PRECIP CHANCES INCREASE TUESDAY NIGHT AND
WEDNESDAY FAVORING THE EUROPEAN MODEL WITH A CAD AIRMASS AND
OVERRUNNING SCENARIO SETTING UP AND PRODUCING A COLD RAIN.
HOWEVER...TEMPERATURES ARE CLOSE TUESDAY NIGHT FOR SOME TYPE OF
WINTER MIX FAVORING SNOW AND FREEZING RAIN FOR A FEW OF THE FAR
NORTHERN COUNTIES. SURFACE LOW PRESSURE MOVES TO E COAST THURSDAY
MORNING GREATLY DIMINISHING PRECIP CHANCES ACROSS THE AREA. ONCE
AGAIN TEMPERATURES CLOSE WEDNESDAY NIGHT FOR SOME TYPE OR MIX
FAVORING RAIN AND SNOW.
BDL
AVIATION...
06Z UPDATE...
AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE CWFA TONIGHT/EARLY
SATURDAY. PRECIPITATION IS EXPECTED TO SPREAD ACROSS PORTIONS OF
NORTH AND CENTRAL GA OVERNIGHT...WITH MOST SIGNIFICANT PRECIP CSG TO
MCN AND SOUTH. SOME LIGHT MIX OF RAIN AND SNOW IS POSSIBLE ACROSS
NORTH GA BEFORE 13Z...INCLUDING ATL. CEILINGS SHOULD STAY ABOVE 3
THSD FT WITH NO VISIBILITY RESTRICTIONS ANTICIPATED. WINDS LIGHT AND
VARIABLE THIS MORNING...BECOMING LIGHT NORTHWEST AFTER 13Z.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 54 36 59 37 / 0 50 40 5
ATLANTA 50 37 57 39 / 5 40 30 5
BLAIRSVILLE 46 32 51 32 / 5 30 30 5
CARTERSVILLE 48 32 56 32 / 5 30 20 5
COLUMBUS 55 39 59 38 / 5 70 60 5
GAINESVILLE 49 36 54 38 / 5 30 30 5
MACON 56 37 60 37 / 5 80 70 5
ROME 47 30 54 31 / 5 30 20 5
PEACHTREE CITY 52 34 58 33 / 5 60 50 5
VIDALIA 59 44 60 43 / 5 80 70 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1119 PM CST Fri Feb 7 2014
.UPDATE:
Issued at 806 PM CST Fri Feb 7 2014
Quick update to the forecast to boost POPs generally north of
Interstate 70 after midnight where both RAP and latest NAM show
area of light snow developing ahead of the approaching shortwave
in weak warm advection. Up to a tenth of an inch of liquid could
lead to an inch of snow for locations along a Mexico, Bowling
Green, White Hall line. Outside of this area lighter snow totals
of less than a half of an inch are expected from Columbia to the
northern St. Louis Metro. Will continue to monitor radar trends
and adjust short term grids accordingly.
CVKING
&&
.SHORT TERM: (Through Late Tonight)
Issued at 325 PM CST Fri Feb 7 2014
This afternoon: a pair of well-sheared upper level shortwave
disturbances exist, one to our north and the other to our south in
what is largely a zonal flow regime over the central U.S. The core
of the Arctic airmass continues to dominate our region but is now to
our east over SW Indiana as a 1032mb hi pressure. An extensive area
of clouds once again exists mainly to our W and S, but unlike 24hrs
ago, these clouds will be invading to stay for a while, with many
areas already cloudy now. Temps have been able to get into the
teens today, with areas able to remain sunny the longest likely to
hit 20F before sundown.
The well-sheared shortwave disturbances will remain to our north and
south and have no effect on our wx, exiting to the east by midnight.
However, another stronger shortwave TROF over the west TX panhandle
will shoot east, interacting with the tail end of the first southern
wave, with some decent potential of a period or two of light snow
for late this evening and the early part of the overnight. Yet
another shortwave, currently over the Pac NW, will make an approach
to our northern CWA towards 12z with increasing PoPs for light snow
there.
What is left in-between for much of tonight will be a gradually
lowering deck of clouds in a broadscale, weak WAA regime. We have
had lo chance PoPs in place for sometime now and cannot rule out
areas of light snow developing, especially given how KMCI has had a
couple hours of flurries this afternoon. Will leave these lo PoPs
in place to maintain the mention with localized dustings of snow
possible.
Cloudy skies and gradually increasing S flow are expected to result
in min temps at many locations being hit during the evening with
steady or slightly rising temps overnight. Generally went at or
below the lowest MOS values for IL sites and northeast MO, with more
of a MOS blend elsewhere where the clouds are more firmly
established.
TES
.LONG TERM: (Saturday through Next Friday)
Issued at 325 PM CST Fri Feb 7 2014
Low-mid level waa is expected on Saturday ahead of a shortwave and
associated weak surface low which will move ewd through IA and nrn
IL. It appears that most of the snow will remain n-ne of our
forecast area ahead and north of the track of the vort max/sfc
low, but there may be a little light snow over nern MO and w cntrl
IL and flurries elsewhere. Could also not rule out a little
drizzle or freezing drizzle as some of the forecast soundings
indicate shallow moisture/cloud cover with a lack of ice crystals
in this low level cloud deck at times. S-swly sfc/low level winds
ahead of the weak surface low and trailing cold front will lead to
warmer temperatures on Saturday, likely rising above the freezing
mark across portions of cntrl and sern MO. The models were a
little slower with the progression of the cold front dropping sewd
through our forecast area Saturday night and Sunday mrng. The
models lag the 850 mb front well behind the sfc cold front with
continued low-mid level waa over the surface cold front Saturday
ngt and Sunday mrng mainly across the srn portion of our forecast
area. The models, particularly the NAM also depict some low-mid
level frontogenesis across our area late Saturday ngt and Sunday.
The models qpf forecast also seem to be hinting at a possible W-E
band of snow moving swd through our forecast area from late
Saturday ngt through Sunday evng. Still a lot of uncertainty in
the precipitation forecast for Saturday ngt through Sunday ngt,
but there may be the potential for some areas to pick up 1-3 inches
of snow. Colder air will filter slowly swd into our forecast area
Sunday and Sunday ngt as a strong 1035-1040 mb surface ridge
builds sewd into our area. Wind chills will drop to around 15 to
20 below zero late Sunday ngt and early Monday mrng across nern MO
and w cntrl IL. There may still be a chance of snow across
portions of sern MO and swrn IL on Monday as weak nw flow
shortwaves continue to drop sewd through our region and a storm
system passes to our south, but most of the precipitation should be
south of the forecast area by Monday as the cold and dry air mass
continues to build s-sewd through MO and IL. The extended forecast
appears dry as the models keep the shortwave energy either well
north or south of our forecast area. As sly surface winds return
later in the work week as the surface high shifts east of the
region we should see warmer temperatures by Wednesday and
Thursday.
GKS
&&
.AVIATION: (For the 06z TAFs through 06z Saturday Night)
Issued at 1119 PM CST Fri Feb 7 2014
Shortwave sliding east through Missouri as of 05z, helping to
generate some light snow. So added mention of mvfr cigs/vsbys for
taf sites along I-70 corridor and just flurries at KUIN. Snow to
taper off by sunrise as shortwave exits region. Then next system
to slide southeast through region during the day with best chances
of snow just northeast of taf sites, so kept mvfr cigs/vsbys at
KUIN and dry elsewhere. Mvfr cigs to persist through rest of
forecast period. As for winds, southeast to south winds veering to
the west then northwest as next weak frontal boundary moves
through Saturday evening.
Specifics for KSTL:
Shortwave sliding east through Missouri as of 05z, helping to
generate some light snow. So added mention of mvfr cigs/vsbys for
metro area by 08z Saturday. Snow to taper off by 12z Saturday as
shortwave exits region. Then next system to slide southeast
through region during the day with best chances of snow just
northeast of metro area, so kept taf dry. Mvfr cigs to persist
through rest of forecast period. As for winds, southeast to veer
to the south by 12z Saturday then to the northwest as next weak
frontal boundary moves through around 10z Sunday.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
300 AM CST SAT FEB 8 2014
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 300 AM CST SAT FEB 8 2014
TIMING/STRENGTH OF ANY POPS MAIN ISSUE...MAINLY TONIGHT AND
SUNDAY...WITH LINGERING LOW CLOUDS SOUTH TODAY AND MIN TEMPS BY
MONDAY MORNING OTHER CONCERNS.
ALTHOUGH LIGHT SNOW...MOSTLY FLURRIES...HAVE BEEN PREVALENT
OVERNIGHT...RADAR RETURNS HAD INCREASED SOMEWHAT AFTER 06Z IN
NERN ZONES. THIS IS IN ADVANCE OF COMPACT AND WELL DEFINED VORT
MAX OVER NCNTRL NEBR/SCNTRL SD VICINITY AT 07Z PER SATELLITE
IMAGERY. THIS DISTURBANCE WAS FORECAST TO BE EAST OF THE FORECAST
AREA BY 18Z THUS WOULD SUSPECT ANY MEASURABLE PRECIP NRN/ECNTRL
ZONES WOULD END FAIRLY QUICKLY THIS MORNING AND POSSIBLY EVEN BE
MOSTLY E OF FA BY 12Z. ALTHOUGH THIS SYSTEM WAS ALSO CLEARING OUT
LOW CLOUDS PARTS OF WRN/NRN NEBR...BUT WITH TRAILING MID/HIGH
CLOUDS...IT WAS HAVING LESS SUCCESS CLEARING LOW CLOUDS OUT
ACROSS THE SOUTH. SHORT RANGE HRRR BASICALLY LEFT THESE LOW CLOUDS
IN ALL DAY SO DELAYED CLEARING FAR SOUTH. ALSO WITH SLOWER
CLEARING PARTS OF THE EAST/SOUTH...LOWERED HIGHS A BIT.
LIKEWISE...RAISED MINS TO AROUND 10 SOUTH FOR TONIGHT AS COLD
ADVECTION ONLY MODEST BEHIND FRONT.
FAST UPPER FLOW WITH SEVERAL EMBEDDED WAVES AND TIMING/LOCATION
DIFFERENCES BETWEEN 00Z NAM/GFS AND ECMWF IN QPF PLACEMENT CREATE
A OVER-SMOOTHED OR OVER-SIMPLIFIED PRECIP FORECAST POTENTIAL. BUT
OTHER THAN GOING FOR AN ALL-OR-NOTHING BY FOLLOWING ONE
PARTICULAR MODEL...IT PROBABLY IS ABOUT THE BEST WAY TO HANDLE
IT. THUS...BROUGHT IN SMALL POPS WRN ZONES LATE THIS AFTN PER GFS
AND THEN INCREASED THEM TO CHC CATEGORY ACROSS A WIDE WEST TO
EAST SWATH THIS EVENING PER MODELS BUT ALSO MENTIONED SMALL
CHANCES N TO ACCOUNT FOR THE FARTHER N ECMWF. THEN FOR SUNDAY
INCREASED POPS BACK INTO CHC CATEGORY S USING MORE OF THE ECMWF.
A QUICK LOOK AT THE 06Z NAM SUGGESTED SHOWED THAT MODEL COMING IN
DRIER THAN ITS PRIOR RUN AND LOOKING MORE LIKE THE DRY 00Z GFS.
THUS MADE A FEW LAST MINUTE CHANGES...MAINLY LOWERED AFTN POPS
QUICKER.
AIRMASS PRESSING DOWN BEHIND WAVE ON SUNDAY IS PRETTY COLD AND
WITH SFC RIDGE AXIS BUILDING DOWN THE MO RIVER VALLEY...POTENTIAL
FOR VERY COLD TEMPERATURES STILL EXISTS. MAIN CAVEAT WOULD BE IF
MID CLOUDS SPREAD BACK OVER AREA PER 00Z GFS...FOR THAT REASON
KEPT ERN ZONES THE COLDEST BUT BLENDED WRN COUNTIES INTO WARMER
NEIGHBORS NUMBERS WHICH RAISED THEM A FEW DEGREES.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 300 AM CST SAT FEB 8 2014
FAST FLOW ALSO LENDS FOR POTENTIAL MODEL SOLUTION FLIP-FLOPPING
WITH ECMWF A GOOD EXAMPLE. YDA THE 00Z RUN SUGGESTED A MIDWEEK
WAVE WOULD PUSH A MODEST COLD FRONT INTO FORECAST AREA BY
THURSDAY...BUT MOST RECENT 00Z RUN HAD A TRAILING WAVE SPREADING
DECENT WARM ADVECTION ACROSS FA INTO THURSDAY MORNING AND THEN
COOL ADVECTION WEAK ENOUGH TO ALLOW GOOD MIXING AND VERY MILD
TEMPS BY AFTN. MEANWHILE...GFS WAS STRONGER WITH COLD ADVECTION
INTO THURSDAY MORNING AND MUCH COLDER WITH FORECAST HIGHS.
THUS...DECIDED TO LEAVE IN A BLEND OF PRIOR RUN/PREVIOUS FORECAST
FOR MAX TEMPERATURES AND HANDLE ANY ADJUSTMENTS WHEN MODELS BECOME
MORE IN-LINE AND CONSISTENT. DID LOWER LOWS ACROSS THE EAST TUE AM
SINCE THAT AREA WILL BE LAST TO FEEL OVERNIGHT IMPACTS OF RETURN
FLOW/WARM ADVECTION PER GENERAL CONSENSUS AMONG MODELS. AS FOR
PRECIP...ADDED SLIGHT CHC SNOW POPS TO FRIDAY OTHERWISE EXTENDED
WAS DRY. YDAS 12Z ECMWF WAS FAIRLY STRONG WITH SHORT-WAVE ENERGY
ACTING ON A STALLING COLD FRONT GENERATING A LARGE SWATH OF
MODESTLY HIGH QPF ACROSS ERN NEBR/WRN IA. ALTHOUGH 00Z RUN BACKED
MARKEDLY OFF THAT SOLUTION...IT DID KEEP A WEAK WAVE MOVG TOWARD
AREA BY 00Z SAT WITH A SCATTERING OF LIGHT QPF OVER PLAINS WITH
SOME HINT OF SAME PER 00Z GFS.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1156 PM CST FRI FEB 7 2014
LIGHT FLURRIES WILL CONTINUE AT KOMA FOR ANOTHER HOUR OR TWO...BUT
HAVE ENDED AT KLNK AND THIS SHOULD BE IT FOR ANY PRECIP OVERNIGHT
AT ALL 3 TAF SITES. THE MVFR CIGS HAVE MOVED INTO ALL BUT KOMA AND
WE SHOULD SEE THE CIGS LOWER THERE SOON. THE MVFR CIGS WILL
CONTINUE UNTIL AROUND NOON ON SAT BEFORE WINDS TURN TO THE WEST
AND ALLOW FOR SOME OF THIS TO BE SCATTERED OUT. WE WILL LIKELY SEE
MVFR CIGS AGAIN STARTING ON SAT EVENING AS ANOTHER WEAK SYSTEM
MOVES THROUGH THE AREA. WE MAY NEED TO INCLUDE SOME -SN AT
KOMA/KOFK AS WELL ON SAT EVENING BUT CONFIDENCE IN TIMING AND
PLACEMENT IS TO LOW TO INCLUDE ATTM.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...CHERMOK
LONG TERM...CHERMOK
AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1231 AM EST SAT FEB 8 2014
.SYNOPSIS...
LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST COAST AND INTENSIFY AS
IT ACCELERATES TO THE NORTHEAST AND AWAY FROM THE AREA THROUGH
TONIGHT. A BRIEF WARM-UP IS EXPECTED SUNDAY AHEAD OF A COLD FRONT
THAT WILL CROSS THE CAROLINAS EARLY MONDAY. COLD HIGH PRESSURE WILL
RIDGE ACROSS THE AREA MONDAY AND TUESDAY...AND GIVE WAY TO
DEVELOPING LOW PRESSURE FROM THE GULF OF MEXICO DURING THE MIDDLE
PORTIONS OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 930 PM FRIDAY...BASED ON LATEST IR 11-3.9 MICRON SAT
IMAGERY...HAVE UPDATED SKY CONDITIONS FOR THE REMAINDER OF THIS
EVENING AND OVERNIGHT. CONTINUED THE TREND OF BECOMING COMPLETELY
OVC DURING THE PRE-DAWN SAT HOURS. FAST EASTWARD MOVING MID-LEVEL
SOUTHERN STREAM S/W TROF...WILL REACH THE FLORIDA PAN HANDLE BY
DAYBREAK SAT. PLENTY OF ATLANTIC AND GULF MOISTURE AVBL AS
OVERRUNNING CLOUDINESS DEVELOPS AND PUSHES OVERHEAD MAINLY IN
EARNEST AFTER MIDNIGHT TONIGHT. LATEST HRRR INDICATES STRATIFORM
RAINS TO BREAKOUT AND/OR PUSH INLAND FROM THE COAST DURING THE
PRE-DAWN SAT HOURS. BY DAYBREAK...THE MAJORITY...IF NOT ALL OF
THE ILM CWA...WILL HAVE LIGHT TO POSSIBLY MODERATE STRATIFORM TYPE
RAINS FALLING/OCCURRING. LATEST WINTER TYPE PCPN PARAMETERS REMAIN
CONDUCIVE TO AN ALL LIQUID RAIN EVENT...IE. NO P-TYPE ISSUES FOR
THE ILM CWA. RE-ADJUSTED TONIGHTS LOWS TO OCCUR AROUND OR JUST
AFTER MIDNIGHT WITH MAINLY STEADY TEMPS THERE-AFTER AS CLDS AND
PCPN OVERTAKE THE FORECAST AREA.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...LOW PRESSURE WILL DEVELOP ALONG A BOUNDARY
STALLED OFF THE FL EAST COAST FRI NIGHT THEN TRACK NORTHEAST JUST
OFF THE CAROLINA COAST SAT. ALTHOUGH THE LOW WILL PASS OFF THE
COAST IT WILL BE CLOSE ENOUGH TO SPREAD RAIN OVER THE FORECAST
AREA. RAIN WILL BE ONGOING AS THE PERIOD BEINGS WITH INCREASING
ISENTROPIC LIFT AS THE LOW DEEPENS TAPPING INTO ABUNDANT MOISTURE.
CLOSER TO THE COAST...WHERE MOISTURE IS HIGHEST AND LIFT
STRONGEST...PERIODS OF MODERATE RAIN WILL BE POSSIBLE THROUGH SAT
MORNING. BROAD MID LEVEL TROUGHING OVER MUCH OF THE COUNTRY WILL
BE QUICK TO HUSTLE THE LOW NORTHEAST DURING THE DAY SAT AND BY
EVENING IT WILL BE WELL EAST OF HATTERAS WITH ONLY LOW LEVEL
MOISTURE LINGERING OVER THE REGION. COMBINATION OF CLOUD
COVER...RAIN...AND NORTHERLY WINDS WILL KEEP HIGHS WELL BELOW
CLIMO SAT. MANY AREAS WILL STRUGGLE TO REACH 50.
AS THE LOW DEPARTS HIGH PRESSURE FROM THE SOUTHERN PLAINS WEAKLY
BUILDS INTO THE REGION. MID LEVEL TROUGH AXIS REMAINS WEST OF THE
REGION SO THERE WILL BE NO COLD ADVECTION SAT NIGHT. LOW LEVEL
MOISTURE LINGERS INTO SUN...KEEPING SKIES CLOUDY BUT MOISTURE IS
SHALLOW ENOUGH THAT PRECIP SHOULD NOT BE AN ISSUE. AFOREMENTIONED
LACK OF COLD ADVECTION AND CLOUD COVER WILL KEEP LOWS NEAR CLIMO SAT
NIGHT.
FIRST IN A SERIES OF WEAK SHORTWAVES PASSES OVERHEAD SUN MORNING
WITH SUBSIDENCE IN ITS WAKE AND MIXING HELPING TO ERODE LOW LEVEL
MOISTURE. SKIES WILL BE MOSTLY SUNNY FOR MUCH OF THE DAY BEFORE
CIRRUS ASSOCIATED WITH UPPER MOISTURE AHEAD OF THE NEXT SHORTWAVE
SPREADS OVER THE REGION. ANOTHER COLD FRONT WILL DROP IN FROM THE
NORTHWEST SUN NIGHT BUT THE BOUNDARY STALLS OVER THE SOUTHERN PART
OF THE REGION AS THE PERIOD ENDS. ALTHOUGH THE FRONT WILL LACK
PRECIP IT WILL BRING A SIGNIFICANT INCREASE IN CLOUD COVER. TEMPS
WILL BE NEAR CLIMO SUN AND SUN NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...COLD FRONT WILL DROP SOUTH THROUGH THE
CAROLINAS ON MONDAY BUT WITH A VERY BROAD MID TO UPPER TROUGH
DRAPED ACROSS THE EASTERN CONUS THE FLOW ALOFT WILL REMAIN FAIRLY
ZONAL WITH A DECENT W-SW COMPONENT TO THE FLOW. THEREFORE THE
SHALLOW COOL AIR WILL REINFORCE THE WEDGE WITH LOW CLOUDS AND LOW
END PCP DEVELOPING AS ISENTROPIC LIFT SLOWLY INCREASES BY THE END
OF THE DAY. LOOKS LIKE ENOUGH DRYING WILL OCCUR BEHIND FRONT TO
SQUEEZE OUT A DRY DAY FOR MONDAY...BUT MAY CONTINUE TO SEE A GOOD
DEAL OF CLOUDS.
BY EARLY TUES ISENTROPIC LIFT INCREASES ACROSS THE CAROLINAS LEADING
TO CLOUDS AND INCREASED CHC OF RAIN. BY LATE TUES INTO WED A WAVE OF
LOW PRESSURE MOVING ALONG THE GULF COAST WILL ACT TO ENHANCE THE
WEDGE PATTERN SHARPENING THE COASTAL TROUGH/WARM FRONT EXTENDING UP
THE SOUTHEAST COAST. THE BEST LIFT WILL COME AHEAD OF SHORTWAVE
RIDING THROUGH THE SOUTHEAST TUES NIGHT INTO WEDNESDAY. OVERALL
EXPECT UNSETTLED WEATHER WITH CLOUDS AND PCP OVER THE AREA FROM TUES
THROUGH EARLY THURS. THERE MAY BE ENOUGH COOL AIR IN PLACE TO
PRODUCE SOME MIXED PCP WITH THIS SYSTEM AS TEMPS REMAIN BORDERLINE.
SHOULD SEE A BREAK IN PCP ON THURS BUT A NORTHERN STREAM SYSTEM WILL
FOLLOW CLOSE BEHIND TO PRODUCE INCREASED CHC OF PCP BY THURS NIGHT.
CLOUDS MAY NOT HAVE AN OPPORTUNITY TO CLEAR BEFORE THIS NEXT SYSTEM
COMES BUT BY FRIDAY...THE SHORTWAVE TROUGH AXIS WILL MOVE OFF SHORE
ALLOWING A DEEP DRY AND COOL NW FLOW TO DEVELOP SCOURING OUT ALL
MOISTURE AS HIGH PRESSURE BUILDS IN LATE FRI INTO SATURDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...VFR IS EXPECTED THROUGH THE OVERNIGHT HOURS...WITH
CONDITIONS GRADUALLY DETERIORATING TO MVFR/IFR AFTER SUNRISE
DUE TO LOW CIGS...AREAS OF FOG...AND PERIODS OF HEAVY RAINFALL.
CONDITIONS WILL IMPROVE TO VFR BY THE END OF THE TAF PERIOD.
VFR WITH LIGHT AND VARIABLE WINDS WILL CONTINUE THROUGH SUNRISE.
THE LATEST SATELLITE IMAGERY CONTINUES TO ILLUSTRATE THE
INFILTRATION OF HIGH CLOUDS. ANTICIPATE HIGH CLOUD COVER TO INCREASE
IN COVERAGE BECOMING BKN WITH MID CLOUDS SLOWLY MOVING IN AS WELL
AHEAD OF LOW PRESSURE SET TO MOVE UP THE COAST THROUGHOUT THE
PERIOD. ON SATURDAY...EXPECT NORTH-NORTHEAST WINDS TO INCREASE TO
AOB 10 KT. LATEST TIME-HEIGHT ANALYSIS AND FCST SOUNDINGS SUPPORT
WIDESPREAD RAINFALL ACROSS THE AREA NEAR DAYBREAK...WITH MVFR/IFR
CONDITIONS DUE TO LOW CIGS...AREAS OF FOG...AND PERIODS OF HEAVY
RAINFALL DEVELOPING SHORTLY THEREAFTER. ATTM WOULD ANTICIPATE
RAINFALL TO TAPER OFF DURING THE LATE AFTERNOON AND EARLY EVE HOURS
AS CONDITIONS IMPROVE TO MVFR. EXPECT CONDITIONS TO IMPROVE TO VFR
DURING THE EVE WITH LIGHT AND VARIABLE WINDS.
EXTENDED OUTLOOK...VFR EXPECTED THROUGH MONDAY AFTERNOON.
DETERIORATING CONDITIONS MONDAY NIGHT WITH MODERATE CONFIDENCE FOR
IFR CONDITIONS IN PRECIP TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 945 PM FRIDAY...WEAK RIDGING FROM THE NORTH THIS EVENING...
WILL GIVE WAY TO A DEVELOPING SFC LOW OFF THE SOUTHEAST U.S.
MAINLAND LATE TONIGHT. THE SFC PRESSURE PATTERN AND GRADIENT WILL
BEGIN TO MODIFY DURING THE PRE-DAWN SAT HOURS...WITH LIGHT NE
WINDS INCREASING TO 10-20 KT ACROSS THE LOCAL WATERS WITH FEW
GUSTS UP TO 25 KT. SIGNIFICANT SEAS AT THEIR LOWEST THIS
EVENING...WILL BEGIN TO BUILD DURING THE PRE-DAWN SAT HRS IN
RESPONSE TO THE INCREASING LOCALLY PRODUCED WIND DRIVEN WAVES.
LOOKING AT SIG SEAS OF 2 TO 4 FT...BUILDING TO 3 TO 5 FT BY
DAYBREAK SAT...WITH SOME 6 FOOTERS POSSIBLE OFF CAPE FEAR AND/OR
OFF THE MOUTH OF WINYAH BAY. AVERAGE PERIODS WILL RUN JUST SHY OF
5.0 SECONDS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...PINCHED GRADIENT AT THE START OF THE PERIOD AS
DEVELOPING LOW PASSES JUST EAST OF THE WATERS WILL PUSH NORTH TO
NORTHEAST FLOW TO A SOLID 20 KT DURING THE DAY. ALTHOUGH WINDS MAY
END UP JUST SHORT OF SCA THINK SEAS WILL EXCEED 6 FT IN OUTER WATERS
AND WILL RAISE A 12 HOUR SCA FOR ALL ZONES. TIME DURATION IS LIKELY
A LITTLE LONG ON THE BACKSIDE OF THE ADVISORY BUT IT CAN BE
CANCELLED EARLY IF NEED BE.
ONCE THE SURFACE LOW RAPIDLY DEPARTS LATE SAT INTO SAT NIGHT THE
GRADIENT BECOMES WEAK AND ILL DEFINED. BY MIDNIGHT NORTHERLY FLOW
WILL BE UNDER 10 KT AND SEAS DROP TO 2 TO 3 FT BY SUN MORNING. HIGH
PRESSURE BUILDING IN FROM THE WEST MAINTAINS NORTHERLY FLOW INTO SUN
BEFORE WINDS FLOP TO SOUTHERLY WITH WEAK RIDGE AXIS SHIFTING
OFFSHORE. WEAK COLD FRONT DROPPING IN FROM THE NORTH LATE SUN
INCREASES SOUTHWEST FLOW IN THE AFTERNOON AND EVENING BUT SPEEDS
WILL REMAIN UNDER 15 KT. FRONT STALLS ACROSS OR JUST SOUTH OF THE
WATERS LATE SUN NIGHT. IN THE VICINITY OF THE FRONT WINDS WILL BE
UNDER 10 KT WITH VARIABLE DIRECTION...ACROSS NORTHERN ZONES WINDS
WILL HAVE MORE OF A NORTHWEST COMPONENT. INCREASE IN SPEEDS SUN
PUSHES 2 TO 3 FT SEAS TO 2 TO 4 FT FOR SUN AFTERNOON AND SUN NIGHT.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...COLD FRONT DROPPING SOUTH EARLY MON WILL
PRODUCE A SHARP SHIFT IN WINDS TO THE NORTH THEN NORTHEAST. THIS
WILL LEAD TO WEDGE PATTERN SETTING UP FOR MID WEEK AS WAVE OF LOW
PRESSURE RIDES ACROSS THE GULF COAST ENHANCING THE COASTAL TROUGH
UP THROUGH THE SOUTHEAST ATLANTIC WATERS. WILL SEE NORTHEAST FLOW
SHARPENING UP BY TUES NIGHT AS GRADIENT TIGHTENS BETWEEN WEDGE OF
HIGH PRESSURE INLAND AND TROUGH OFF THE COAST. EXPECT WINDS TO
INCREASE TO 15 TO 20 KTS INTO MON NIGHT INTO TUES WITH A PROLONGED
PERIOD OF ADVISORY CONDITIONS POSSIBLE TUES THROUGH WED
NIGHT...MAINLY IN OUTER WATERS. WINDS IN LOCAL WATERS MAY REMAIN
NORTHEAST BUT THE SHARPENING TROUGH MAY BRING SOUTHEAST WINDS INTO
THE OUTER WATERS ON WED. THE SYSTEM LIFTS OFF TO THE NORTHEAST BY
EARLY THURS LEAVING A LIGHTER NORTHEAST FLOW BEHIND. SEAS OF 2-3
FT EARLY IN THE PERIOD ON MONDAY WILL RISE STEADILY...BECOMING 4-6
FT THROUGH TUESDAY INTO WED BEFORE FINALLY SUBSIDING BY EARLY
THURS AS SYSTEM LIFTS OFF TO THE NORTHEAST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 7 PM EST SATURDAY FOR AMZ250-
252-254-256.
&&
$$
NEAR TERM...DCH
SHORT TERM...III
LONG TERM...RGZ
AVIATION...SGL/RJD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
350 AM CST SAT FEB 8 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CST SAT FEB 8 2014
THE MAIN FOCUS FOR THE SHORT TERM IS ONCE AGAIN TEMPERATURES.
CLOUD COVER WILL PLAY A BIG ROLE WITH RESPECT TO TEMPERATURES
TODAY. THE LATEST GUIDANCE BUMPS UP HIGH TEMPERATURES 5 TO 10
DEGREES ABOVE THE PREVIOUS FORECAST. IF SKIES CLEAR OUT OVER
SOUTHERN NORTH DAKOTA THESE HIGHER TEMPERATURES COULD BE REALIZED.
HOWEVER...IF CLOUDY SKIES PREVAIL THE LOWER GUIDANCE/PREVIOUS
FORECAST WILL LIKELY VERIFY. THE MAIN COLD AIR ADVECTION SURGE
SHOULD HOLD OFF UNTIL LATE AFTERNOON. THEREFORE...I THINK THE
THICKEST CLOUD COVER WILL REMAIN NORTH MOST OF THE DAY. FOR THIS
REASON I WENT WITH THE SLIGHTLY WARMER HIGH TEMPERATURES ACROSS
THE SOUTH.
WITH THE COLD AIR ADVECTION SURGE THE 07 UTC RAP BRINGS IN SOME
LOWER CLOUDS AND LOW LEVEL MOISTURE DURING THE EVENING ACROSS THE
NORTH.SNOW FLURRIES AND EVEN A BRIEF SNOW SHOWER AREN`T OUT OF THE
QUESTION FOR THE NORTHERN COUNTIES SATURDAY EVENING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 350 AM CST SAT FEB 8 2014
THE START OF THE LONG TERM PERIOD WILL FEATURE NORTHWESTERLY FLOW
AT H5 WITH HIGH PRESSURE IN CONTROL AT THE SURFACE. TEMPERATURES
WILL BE COLD...AND COULD SEE THE EVENTUAL NEED FOR A WIND CHILL
ADVISORY. THIS IS ESPECIALLY TRUE SUNDAY NIGHT ACROSS THE NORTH
AND EAST WHERE WIND CHILLS VALUES COULD FALL INTO THE 20S AND 30S
BELOW ZERO.
WEST / NORTHWEST FLOW WILL DOMINATE THROUGH MOST OF NEXT WEEK. THIS
WILL ALLOW A SERIES OF FAST MOVING CLIPPERS TO MAKE THEIR WAY ACROSS
THE DAKOTAS...BRINGING PERIODIC CHANCES OF PRECIPITATION / SNOW. IT
APPEARS THERE IS GENERAL AGREEMENT BETWEEN THE GFS / ECMWF THAT A
SYSTEM TOWARDS THE MIDDLE OF THE WEEK COULD BE THE STRONGEST OF THE
CLIPPERS.
TEMPERATURES WILL SHOW QUITE A BIT OF VARIABILITY AS THE EXTENDED
PROGRESSES WITH PERIODS OF MODERATING TEMPERATURES...FOLLOWED BY
COOLER TEMPERATURES BEHIND THE WAVES. GENERALLY ACCEPTED THE
ALL-BLEND MODEL CONSENSUS REGARDING TEMPERATURES WHICH SHOULD HELP
MITIGATE SOME OF THE POTENTIAL TIMING DIFFICULTIES OF THE WAVES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1230 AM CST SAT FEB 8 2014
VFR CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD AT ALL
TERMINALS. MID TO HIGH LEVEL CLOUDS WILL CONTINUE TO INFILTRATE
THE REGION FROM NORTH TO SOUTH.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...CK
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
401 AM CST SAT FEB 8 2014
.DISCUSSION...
CURRENTLY...A MID LEVEL DISTURBANCE IS MOVING THROUGH THE LOWER
MISSISSIPPI VALLEY ATTM. LIGHT SNOW CONTINUES ROUGHLY NORTH OF A
TUNICA TO CORINTH LINE WITH A MIX OF LIGHT SNOW...SLEET AND
FREEZING RAIN TO THE SOUTH WHERE A LITTLE BIT OF WARM AIR HAS
SNUCK IN BETWEEN 950 AND 900 MB. TEMPS RANGE FROM THE UPPER TEENS
ACROSS NE AR TO LOWER 30S TOWARD MONROE COUNTY MS. SO FAR MANY
PLACES HAVE RECEIVED ABOUT AN 1/2 INCH TO AN INCH WITH UP TO 2
INCHES IN A BAND FROM POINSETT AND CROSS TOWARD TIPTON AND
LAUDERDALE COUNTIES.
TODAY...LATEST NAM AND HRRR SHOWS SOME PRECIP LINGERING THROUGH
MID MORNING. PRECIP WILL BE LIGHT WITH MAINLY LIGHT SNOW NORTH OF
THE TN/MS LINE AND A MIXTURE OF PRECIP TYPES TO THE SOUTH. PRECIP
MAY WIND DOWN AS A PERIOD OF FREEZING DRIZZLE AS WELL. AS A RESULT
DECIDED TO EXTEND THE ADVISORY UNTIL 9 AM CST. EXPECT CLOUDY
CONDITIONS THIS AFTERNOON AND WITH THE NEWLY FALLEN SNOW TEMPS
SHOULD STRUGGLE TO REACH GUIDANCE NUMBERS SO UNDERCUT THEM
SUBSTANTIALLY.
TONIGHT...CLOUDS WILL HANG IN WHICH WILL KEEP TEMPS FROM FREE
FALLING. EXPECT LOWS IN THE 20S TO LOWER 30S.
SUNDAY...NEXT ARCTIC FRONT PUSHES THOUGH DURING THE AFTERNOON.
EXPECT CLOUDY SKIES TO CONTINUE WHILE TEMPS WILL WARM AHEAD OF THE
FRONT. HIGHS WILL RANGE FROM THE UPPER 30S OVER NE AR TO LOWER
50S OVER NE MS.
SUNDAY NIGHT THROUGH MONDAY...UNSETTLED AND COLD PERIOD ACROSS
THE MIDSOUTH AS AN ARCTIC AIRMASS FILTERS IN. THE 00Z ECMWF HAS
JOINED THE GFS AND KEEPS ANY SURFACE WAVE THAT DEVELOPS ALONG THE
ARCTIC FRONT PUSHING THROUGH THE LOWER MISSISSIPPI VALLEY WELL
TO THE SOUTH. AS A RESULT PRECIP CHANCES REMAIN SMALL SUNDAY NIGHT
INTO MONDAY. IF PRECIP DOES OCCUR IT WILL BE OF THE WINTER VARIETY
ACROSS MUCH OF THE AREA. THE NAM IS THE OUTLIER NOW WITH A
SURFACE LOW MOVING FROM THE ARKLATEX INTO CENTRAL MISSISSIPPI
RESULTING IN HIGHER PRECIP CHANCES ACROSS NORTH MISSISSIPPI SUN
NIGHT INTO MONDAY. WILL NEED TO WATCH BUT FOR NOW WILL FOLLOW THE
GFS/ECMWF SOLUTION. TEMPS WILL BE BACK IN THE FREEZER BY MONDAY
WITH HIGHS IN THE 20S AND 30S.
MONDAY NIGHT INTO TUESDAY...PERHAPS THE BEST CHANCE FOR WINTER
WEATHER WILL BE DURING THIS TIME FRAME. THE ARCTIC AIRMASS WILL BE
ENTRENCHED OVER THE AREA WHILE AN UPPER LEVEL DISTURBANCE WITH
GOOD MOISTURE AND SOME LIFT PUSHES THROUGH. THE GFS IS MOST
AGGRESSIVE WITH PRECIP AMOUNTS AND SUGGESTS 1-2 INCHES OF SNOW
WITH THE ECMWF SHOWING LESSER AMOUNTS. THE NAM IS ALSO PICKING UP
THIS DISTURBANCE. AS A RESULT HAVE INCREASED POPS TO 50 PERCENT
ACROSS MUCH OF THE AREA. PRECIP TYPE WOULD BE MAINLY SNOW WITH
SOME SLEET POSSIBLE SOUTH. PRECIP WILL TAPER OFF TUESDAY WITH SOME
LINGERING SNOW OVER NORTH MISSISSIPPI. TUESDAY WILL BE COLD WITH
HIGHS IN THE 20S AND 30S.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...ARCTIC HIGH PRESSURE
LOOSES ITS GRIP ACROSS THE AREA ON WEDNESDAY AND TEMPS START TO
WARM. A POTENT UPPER TROUGH DROPS INTO THE CENTER OF THE COUNTRY
WEDNESDAY INTO WEDNESDAY NIGHT AND A SURFACE LOW BEGINS TO DEVELOP
ALONG THE EASTERN SEABOARD WITH MOST OF THE MOISTURE AND LIFT
REMAINING EAST OF THE MIDSOUTH. AS A RESULT PRECIP CHANCES ARE NOT
GREAT DURING THIS TIME FRAME.
THURSDAY AND FRIDAY...LOOKS DRY AND MILDER WITH TEMPS CLOSER TO
NORMAL.
SJM
&&
.AVIATION...
06Z TAF SET
SNOW CONTINUES TO SPREAD INTO THE MIDSOUTH. LOOKS LIKE NORTH
MISSISSIPPI WILL CONTINUE TO SEE THE BEST BANDS THUS HAVE LOWERED
VSBYS AND CIGS AT KTUP. ALSO WENT MORE PESSIMISTIC WITH CLOUDS
TOMORROW. LEFT IFR CONDITIONS AT KMEM AND KMKL THROUGH 00Z AND 20Z
AT KTUP. THEREAFTER...EXPECT MVFR CIGS THROUGH THE REST OF THE
PERIOD. LIGHT AND VARIABLE WINDS ARE EXPECTED OVER THE NEXT 24
HOURS.
KRM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 33 30 47 28 / 30 10 10 30
MKL 32 26 46 26 / 40 10 10 30
JBR 28 25 39 22 / 20 10 10 30
TUP 39 31 53 35 / 40 10 10 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR CLAY-
CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-
MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR DUNKLIN-
PEMISCOT.
MS...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR ALCORN-
BENTON MS-CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-
LAFAYETTE-LEE MS-MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-
QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-
YALOBUSHA.
TN...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR BENTON
TN-CARROLL-CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-
HARDEMAN-HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-
MADISON-MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1104 PM CST FRI FEB 7 2014
.UPDATE... /ISSUED 921 PM CST FRI FEB 7 2014/
BASED ON CURRENT RADAR TRENDS...IT APPEARS THAT MOST OF NORTH
MISSISSIPPI WILL AT LEAST SEE ACCUMULATING SNOW NEAR AN INCH WITH
ISOLATED AREAS POSSIBLY SEEING A BIT MORE. TO ADDRESS THIS...HAVE
ISSUED A NEW WINTER WEATHER ADVISORY TO INCLUDE THE REST OF WEST
TENNESSEE AND NORTH MISSISSIPPI. BASED ON THE LATEST HRRR MODEL
AND SREF GUIDANCE...ENHANCED LIFT AHEAD OF A POTENT SHORTWAVE WILL
INCREASE BANDING OF SNOW...LEADING TO HEAVY SNOW SHOWERS AT TIMES.
AS THE WAVE SWINGS THROUGH...THE HEAVIEST SNOW WILL OCCUR OVER THE
NEXT FEW HOURS.
WE HAVE ALREADY RECEIVED A FEW REPORTS OF ROADS BECOMING SNOW
COVERED...MAINLY IN POINSETT AND CROSS COUNTIES IN EASTERN
ARKANSAS...AND EVEN A FEW SPOTS IN NORTHERN SHELBY COUNTY TENNESSEE.
THIS TREND IS EXPECTED TO CONTINUE ACROSS THE REST OF THE MID-SOUTH.
NEW ZONES AND UPDATED PRODUCTS ARE ALREADY AVAILABLE.
AC3
&&
.DISCUSSION... /ISSUED 517 PM CST FRI FEB 7 2014/
DISCUSSION...WATER VAPOR SATELLITE/UPPER AIR PROFILER TRENDS THIS
AFTERNOON INDICATE AN SHORTWAVE TROUGH MOVING ACROSS THE SOUTHERN
PLAINS. CLOUDY SKIES PERSIST ACROSS THE MID SOUTH AS OF 3 PM CST
WITH TEMPERATURES PREDOMINANTLY IN THE TEENS TO MIDDLE 20S NORTH
OF I-40 AND UPPER 20S TO THE LOWER 30S SOUTH. WINTER PRECIPITATION
POTENTIAL TONIGHT AND AGAIN SUNDAY NIGHT THROUGH TUESDAY NIGHT
REMAINS THE PREDOMINANT CHALLENGES IN THIS AFTERNOON/S FORECAST.
SHORT TERM...(TONIGHT THROUGH SUNDAY)...A SHORTWAVE TROUGH OVER
THE SOUTHERN PLAINS WILL MOVE INTO THE LOWER MISSISSIPPI VALLEY
TONIGHT. THIS HAS HELPED TO ENHANCE LIFT ACROSS THE LOWER
MISSISSIPPI VALLEY LATE THIS AFTERNOON AS EVIDENT IN THE LATEST
REGIONAL WSR-88D RADAR TRENDS. 290-295K SURFACES SHOW INCREASING
ISENTROPIC ASCENT THROUGHOUT THE NIGHT. BASED ON THE LATEST SHORT
TERM TRENDS DECIDED TO EXTEND THE WINTER WEATHER ADVISORY A BIT
FURTHER SOUTHWEST AS ACTIVITY OVER NORTHERN LOUISIANA MAY MOVE
ACROSS AREAS SOUTH OF I-40 TONIGHT. AT THIS TIME...FEEL THE BEST
POTENTIAL FOR SNOW REACHING ONE INCH WILL BE ACROSS AREAS MAINLY
ALONG AND NORTH OF I-40...EAST ARKANSAS SOUTH OF I-40...PORTIONS
OF NORTHWEST MISSISSIPPI. ONE INCH TO PERHAPS LOCALLY 2 INCHES IS
POSSIBLE ACROSS THE NORTH WITH AMOUNTS AROUND 1 INCH ACROSS EAST
ARKANSAS/NORTHWEST MISSISSIPPI. EVENING SHIFT WILL CONTINUE TO
SHORT MONITOR TRENDS AND ADJUST HEADLINES IF NECESSARY.
A BREAK IN THE PRECIPITATION IS EXPECTED FOR SATURDAY AS THE
SHORTWAVE MOVES EAST AND HIGH PRESSURE RETURNS THROUGH SUNDAY.
TEMPERATURES WILL REMAIN BELOW NORMAL WITH TEMPERATURES MODERATING
INTO THE 40S SOUTH OF I-40 ON MONDAY.
LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)...A VERY COMPLEX
PATTERN WILL TAKE SHAPE ACROSS THE LOWER MISSISSIPPI VALLEY
BEGINNING SUNDAY NIGHT AS AN ARCTIC COLD FRONT DROPS DOWN INTO THE
LOWER MISSISSIPPI VALLEY AND PRECIPITATION DEVELOPS ACROSS THE
REGION. PRECIPITATION NORTH OF I-40 IS EXPECTED TO START OFF AS
SNOW...WITH A TRANSITION TO MIXED PRECIPITATION /FREEZING
RAIN...SLEET...SNOW/ LATER SUNDAY NIGHT INTO MONDAY. 12Z MODELS
DISAGREE WITH THE DEPTH OF THE COLD AIR WITH THIS SYSTEM AND
SUBSEQUENT PRECIPITATION TYPES/AMOUNTS ARE STILL SOMEWHAT
UNCERTAIN AT THIS POINT. FURTHER ADJUSTMENTS TO PRECIPITATION
TYPES/AMOUNTS ARE LIKELY WHEN MODELS COME INTO BETTER AGREEMENT.
PRECIPITATION CHANCES WILL GRADUALLY TRANSITION SOUTH OF I-40 BY
TUESDAY. ANOTHER UPPER LEVEL SHORTWAVE WILL MOVE ACROSS THE REGION
TUESDAY NIGHT AND WEDNESDAY WITH THE BEST PRECIPITATION CHANCES
OCCURRING MAINLY SOUTH OF I-40. PRECIPITATION TYPE ISSUES MAY
STILL REMAIN WITH THIS SECOND SYSTEM WITH ADDITIONAL ADJUSTMENTS
LIKELY DURING THIS TIMEFRAME.
&&
.AVIATION...
06Z TAF SET
SNOW CONTINUES TO SPREAD INTO THE MIDSOUTH. LOOKS LIKE NORTH
MISSISSIPPI WILL CONTINUE TO SEE THE BEST BANDS THUS HAVE LOWERED
VSBYS AND CIGS AT KTUP. ALSO WENT MORE PESSIMISTIC WITH CLOUDS
TOMORROW. LEFT IFR CONDITIONS AT KMEM AND KMKL THROUGH 00Z AND 20Z
AT KTUP. THEREAFTER...EXPECT MVFR CIGS THROUGH THE REST OF THE
PERIOD. LIGHT AND VARIABLE WINDS ARE EXPECTED OVER THE NEXT 24
HOURS.
KRM
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 24 40 28 44 / 70 10 10 10
MKL 21 38 23 41 / 60 10 10 10
JBR 19 33 23 38 / 70 10 10 10
TUP 26 46 28 49 / 60 10 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR CLAY-
CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-
MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR DUNKLIN-
PEMISCOT.
MS...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR ALCORN-
BENTON MS-CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-
LAFAYETTE-LEE MS-MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-
QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-
YALOBUSHA.
TN...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR BENTON TN-
CARROLL-CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-
HARDEMAN-HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-
MADISON-MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1124 PM CST FRI FEB 7 2014
.UPDATE...
ONLY UPDATE AT THIS TIME WILL BE TO GO AHEAD AND MENTION PATCHY
FREEZING FOG DURING THE OVERNIGHT HOURS. SKIES CONTINUE TO CLEAR
FROM THE WEST AND THE CHANCES FOR PATCHY ARE LOOKING A BIT BETTER.
WE STILL DO NOT BELIEVE FOG WILL BE WIDESPREAD OR DENSE...BUT JUST
ENOUGH TO PRODUCE A THIN GLAZE OF ICE ON CARS...TABLES...AND OTHER
ELEVATED SURFACES IN AREAS THAT IT MAY FORM. OTHERWISE THE GRIDS
ARE IN GOOD SHAPE.
30
&&
.AVIATION...
/06Z TAFS/
CHALLENGES OVERNIGHT WITH THE SHORTWAVE EXITING TO THE EAST WILL
BE TOP DOWN DRYING WITH SHALLOW BOUNDARY LAYER MOISTURE PERSISTING
AND A LIGHT SSE WINDS. HRRR AND NAM12 BOTH HIT ON SOME FG/FZFG
POTENTIAL WEST OF I-35 BY SUNRISE SATURDAY. THE CHALLENGE IS WILL
THE LACK OF RADIATIONAL COOLING AND SOUTH WINDS STAYING UP AROUND
5 KTS BE ENOUGH TO KEEP VSBYS UP. HAVE PLAYED THE MIDDLE OF THE
ROAD HERE AND WILL INTRODUCE IFR VSBYS/CIGS...BUT KEEP VSBYS 2-3
SM ACROSS ALL AIRPORTS AROUND MORNING WITH THE THOUGH ANY DENSE
FZFG MORE OF A POSSIBILITY ACROSS THE WESTERN THIRD OF THE AREA
WHERE MOISTURE IS MORE SHALLOW.
CONDITIONS SHOULD RISE BACK INTO MVFR BY MID MORNING AS WAA ENSUES
AHEAD OF THE NEXT SHORTWAVE DISTURBANCE CURRENTLY MOVING OVER THE
GREAT BASIN. THE WAA SHOULD BE ENOUGH TO MIX OUT CIGS FOR
SCATTERED CLOUDINESS BY 18Z/AFTER.
TOMORROW NIGHT IT APPEARS BETTER FOR FG WITH NEAR SURFACE MOISTURE
VERY SHALLOW WITH CONTINUED WAA OVER THE TOP. LESS CLOUDS AROUND
WILL INHIBIT RADIATIONAL COOLING AND WINDS TO DROP TO LESS THAN 5
KTS AGAIN SAT NIGHT/SUN MORNING.
05/
&&
.PREV UPDATE...
.UPDATE...
THE WINTER WEATHER ADVISORY HAS BEEN ALLOWED TO EXPIRE AT 6 PM AS
SCHEDULED. THE UPPER LEVEL FEATURE RESPONSIBLE FOR THE
PRECIPITATION CAN BE SEEN ON WATER VAPOR IMAGERY SWINGING EAST
ACROSS TEXAS...WHILE RADAR INDICATES PRECIPITATION COMING TO AN
END OVER OUR EASTERN COUNTIES. WE WILL STILL LEAVE THE MENTION OF
FLURRIES OVER NORTHEASTERN COUNTIES...AND A SLIGHT CHANCE OF
FREEZING RAIN OR SLEET OVER THE EASTERN COUNTIES SOUTH OF
INTERSTATE 20...WHERE PRECIPITATION MAY LINGER FOR A FEW MORE
HOURS.
THE NEXT THING TO WATCH FOR WILL BE THE POSSIBILITY OF FOG
DEVELOPMENT OVERNIGHT AS TEMPERATURES COOL AND CLOUDS ERODE FROM
WEST TO EAST. FOR NOW WE WILL STICK WITH PATCHY FOG...FEELING THAT
SOUTH WINDS AROUND 5 MPH WILL MIX THE LOWER ATMOSPHERE ENOUGH TO
INHIBIT DENSE FOG DEVELOPMENT. IF FOG DOES BECOME MORE DENSE OR
MORE WIDESPREAD THAN EXPECTED...WE WOULD NEED TO CONSIDER A FREEZING
FOG ADVISORY FOR THOSE AREAS AFFECTED. HOPEFULLY FOG WILL REMAIN
PATCHY AND LIGHT...BUT STAY TUNED TO THE LATEST UPDATES A WE HEAD
INTO THE OVERNIGHT HOURS.
30
&&
.PREV DISCUSSION... /ISSUED 316 PM CST FRI FEB 7 2014/
STRONG UPPER LEVEL SHORTWAVE IS CURRENTLY MOVING ACROSS THE REGION
AND WILL RAPIDLY MOVE EAST OF THE AREA TONIGHT. A BAND OF SNOWFALL
HAS DEVELOPED ACROSS THE NORTHWEST AND NORTHERN ZONES TODAY AND
THIS BAND WILL CONTINUE TO MOVE GENERALLY EAST. SO FAR MEASURABLE
SNOW HAS BEEN CONFINED THE REGION FROM OLNEY TO BOWIE TO
SHERMAN...WITH THE SOUTHERN PART OF THE ADVISORY FOR SNOW NOT
SEEING MUCH OF ANYTHING. WE MAY CANCEL A FEW OF THESE SOUTHERN
COUNTIES EARLY BASED ON RADAR TRENDS AND EXTRAPOLATION OF THE DRY
SLOT THAT WILL BE ROTATING IN FROM THE SOUTHWEST SHORTLY.
ACROSS THE CENTRAL CWA...INCLUDING THE METROPLEX...THE STRONG
FORCING IS SQUEEZING OUT A FEW SNOW GRAINS/FLURRIES/SLEET
PELLETS...BUT LITTLE OR NO ACCUMULATION IS EXPECTED FROM THIS VERY
LIGHT ACTIVITY.
SOME SHORT TERM MODELS CONTINUE TO SUGGEST CONDITIONAL SYMMETRIC
INSTABILITY WILL BECOME AVAILABLE FOR SLANTWISE CONVECTION OVER
THE NORTHEAST ZONES BETWEEN 4 PM AND 7 PM...BUT SINCE AGREEMENT IS
POOR THERE IS NOT ENOUGH CONFIDENCE TO EITHER CANCEL THE ADVISORY
OVER THE NORTHEAST ZONES EARLY OR EXTEND IT THROUGH 8 OR 9 PM.
WILL KEEP THE ADVISORY GOING THROUGH 6 PM AND WATCH TRENDS TO MAKE
THE CALL ON THAT. SO YES IT IS POSSIBLE A BATCH OF SNOW/SLEET WILL
DEVELOP OVER THE NORTHEAST AND FAR EAST ZONES...WHICH WILL
NECESSITATE EXTENDING THE ADVISORY THERE THROUGH 9 PM OR SO.
ACROSS SOUTHERN AND SOUTHEAST ZONES...THE ADVISORY FOR FREEZING
DRIZZLE CONTINUES AS WELL. THE HEAVIER AND ACCUMULATING FREEZING
DRIZZLE HAS MOVED OFF TO THE NORTHEAST AND WEATHER CONDITIONS HAVE
IMPROVED A BIT ACROSS CENTRAL TEXAS...BUT RADAR SHOWS ONE MORE
BATCH OF DRIZZLE IS MOVING UP FROM SOUTH CENTRAL TEXAS. HOWEVER
SURFACE TEMPERATURES ARE BEGINNING TO WARM ABOVE FREEZING ACROSS
THE FAR SOUTHEAST ZONES. WILL LIKELY CLEAR A FEW SOUTHEASTERN MOST
COUNTIES FROM THE ADVISORY A LITTLE EARLY...BUT BELL AND MCLENNAN
COUNTIES WILL CONTINUE THROUGH 6 PM.
ALL PRECIPITATION WILL SHUT DOWN RAPIDLY FROM WEST TO EAST AS THE
SHORTWAVE CLEARS THE AREA EARLY TO MID EVENING. CLOUDS WILL ALSO
ATTEMPT TO CLEAR FROM WEST TO EAST...BUT THIS CLEARING WILL LOSE
ITS GUSTO AS THE LOW LEVEL INVERSION WILL BE FAIRLY STOUT EAST OF
I-35. IN AREAS WHERE IT CLEARS...CONTINUED TOP DOWN DRYING VIA
SUBSIDENCE ALOFT WILL ENHANCE RADIATIONAL COOLING. THIS MAY ALLOW
AREAS OF FOG TO DEVELOP LATER TONIGHT. WITH TEMPERATURES BELOW
FREEZING...FOG IF IT BECOMES DENSE ENOUGH WOULD RESULT IN SOME ICE
ACCRETION. SINCE SOUTH WINDS INCREASE TO NEAR 5 MPH...IT MAY BE
TOO WINDY FOR THIS FOG TO BECOME DENSE ENOUGH FOR A FREEZING FOG
RISK. WILL NOT FORECAST FREEZING FOG YET...AND THE OVERNIGHT
SHIFT CAN WATCH THE TRENDS CLOSELY.
ASIDE FROM MORNING FOG...GENERALLY SUNNY SKIES ARE EXPECTED OVER
THE AREA TOMORROW. SOUTHWEST WINDS WILL ALSO HELP TO BOOST TEMPS
INTO THE 50S...WITH SOME 60S ACROSS THE SOUTHWEST ZONES. ANOTHER
COOL AND TRANQUIL NIGHT IS EXPECTED SATURDAY NIGHT. MODEL DATA IS
SHOWING STRONG SIGNALS FOR DENSE FOG SATURDAY NIGHT INTO SUNDAY
MORNING NORTH OF I-20. AGAIN THERE IS A CONCERN THAT WITH TEMPS
NEAR OR BELOW FREEZING...FREEZING FOG COULD OCCUR.
ON SUNDAY THE NEXT FRONT WILL BE ORGANIZING OVER THE SOUTHERN
PLAINS AND WILL BEGIN TO MOVE SOUTH THROUGH THE AREA. WITH A FOGGY
START ACROSS THE NORTHERN ZONES...AND FRONTAL PASSAGE AROUND
MIDDAY THERE...THIS MEANS TEMPS WILL LIKELY REMAIN FAIRLY CHILLY.
ACROSS THE SOUTHERN ZONES...SUNNY SKIES AND SOUTHWEST WINDS MEANS
TEMPS WILL SOAR TO NEAR 70 DEGREES. THE COLD FRONT WILL PUSH
THROUGH SUNDAY EVENING ACROSS THE SOUTHERN HALF OF THE AREA WITH
TEMPS TUMBLING BACK INTO THE 30S.
THE SUNDAY FRONT WILL BE VERY SHALLOW INITIALLY WITH NEARLY
SATURATED LOW LEVELS AND WEAK ISENTROPIC LIFT UP AND OVER THE COLD
DOME. BY SUNDAY NIGHT AND MONDAY MORNING...DRIZZLE IS EXPECTED TO
DEVELOP BEHIND THE FRONT. AS TEMPS DROP BELOW FREEZING ACROSS THE
NORTHWESTERN PARTS OF THE AREA NEAR DAYBREAK MONDAY MORNING...THIS
DRIZZLE WOULD POSE A LIGHT ICING RISK. THE FRONTAL LAYER WILL
DEEPEN AND DRY OUT MONDAY AFTERNOON AND EVENING...WITH DRIZZLE OR
RAIN CHANCES LIKELY ENDING. HOWEVER BY TUESDAY MORNING THE NEXT
SHORTWAVE WILL BE APPROACHING THE AREA WITH MORE SIGNIFICANT
ISENTROPIC LIFT SPREADING ACROSS THE REGION.
MODEL GUIDANCE GENERALLY HAS TRENDED TOWARD THE ECMWF FORECAST OF
THE LAST FEW DAYS WITH A WEAKER SHORTWAVE AND A MORE SOUTHERLY
TRACK. THE FRONTAL BAROCLINIC ZONE WILL PUSH WELL SOUTH OF THE
REGION WITH THE COLD FRONT...AND THAT SUPPORTS A MORE SOUTHERLY
TRACK OF THIS UPPER LEVEL ENERGY. HIGHEST POPS WILL BE ACROSS THE
SOUTHERN ZONES WHERE THE MORE SIGNIFICANT PRECIPITATION IS
EXPECTED. MODEL GUIDANCE ACROSS THE SOUTHERN HALF OF THE AREA IS
FORECASTING THE PRECIP TYPE TO REMAIN A COLD RAIN. ACROSS THE
NORTHERN HALF OF THE CWA...PRECIP AMOUNTS SHOULD BE ON THE LIGHT
SIDE...BUT THERMAL PROFILES WOULD BE COLD ENOUGH TO SUPPORT A
WINTER MIX. RIGHT NOW THERE ARE NO SIGNS THAT THIS WILL BE A MAJOR
WINTER STORM...BUT ANY LIGHT WINTRY PRECIP WILL CAUSE SOME ISSUES.
IN THE WAKE OF THE TUESDAY SYSTEM...RAPID DRYING AND WARMING WILL
OCCUR WEDNESDAY AND THURSDAY. THE UPPER LEVEL PATTERN LOOKS TO
SHIFT NEXT WEEK WITH A MORE PROGRESSIVE LONGWAVE PATTERN. THE JET
STREAM SHOULD MOVE FARTHER NORTH AS AN UPPER RIDGE OVER THE
SUBTROPICAL EASTERN PACIFIC INTENSIFIES. THIS SHOULD KEEP THE
ARCTIC AIR BOTTLED UP IN CANADA AS LOW PRESSURE SYSTEMS BEGIN TO
TRACK ALONG THE CANADIAN/US BORDER. FOR NORTH TEXAS WE WILL LIKELY
SEE FREQUENT MID-FEBRUARY PACIFIC FRONTS...BUT UNFORTUNATELY
RIDGING EXTENDING UP THROUGH THE SONORA DESERT WILL PUT US IN A
DRIER FLOW ALOFT. RAIN CHANCES LOOK MINIMAL...BUT TEMPERATURES
SHOULD WARM TO NEAR OR ABOVE NORMAL.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 27 55 33 58 31 / 10 0 0 10 10
WACO, TX 26 64 37 70 36 / 10 0 0 10 10
PARIS, TX 26 49 30 55 35 / 10 0 0 10 10
DENTON, TX 25 50 29 53 30 / 10 0 0 10 10
MCKINNEY, TX 25 51 29 55 31 / 10 0 0 10 10
DALLAS, TX 28 55 35 59 31 / 10 0 0 10 10
TERRELL, TX 27 55 33 61 33 / 10 0 0 10 10
CORSICANA, TX 28 59 38 65 36 / 10 0 0 5 10
TEMPLE, TX 26 64 39 72 37 / 10 0 0 5 10
MINERAL WELLS, TX 24 56 31 56 30 / 5 0 0 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/30
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1116 PM CST FRI FEB 7 2014
.AVIATION...
/06Z TAFS/
CHALLENGES OVERNIGHT WITH THE SHORTWAVE EXITING TO THE EAST WILL
BE TOP DOWN DRYING WITH SHALLOW BOUNDARY LAYER MOISTURE PERSISTING
AND A LIGHT SSE WINDS. HRRR AND NAM12 BOTH HIT ON SOME FG/FZFG
POTENTIAL WEST OF I-35 BY SUNRISE SATURDAY. THE CHALLENGE IS WILL
THE LACK OF RADIATIONAL COOLING AND SOUTH WINDS STAYING UP AROUND
5 KTS BE ENOUGH TO KEEP VSBYS UP. HAVE PLAYED THE MIDDLE OF THE
ROAD HERE AND WILL INTRODUCE IFR VSBYS/CIGS...BUT KEEP VSBYS 2-3
SM ACROSS ALL AIRPORTS AROUND MORNING WITH THE THOUGH ANY DENSE
FZFG MORE OF A POSSIBILITY ACROSS THE WESTERN THIRD OF THE AREA
WHERE MOISTURE IS MORE SHALLOW.
CONDITIONS SHOULD RISE BACK INTO MVFR BY MID MORNING AS WAA ENSUES
AHEAD OF THE NEXT SHORTWAVE DISTURBANCE CURRENTLY MOVING OVER THE
GREAT BASIN. THE WAA SHOULD BE ENOUGH TO MIX OUT CIGS FOR
SCATTERED CLOUDINESS BY 18Z/AFTER.
TOMORROW NIGHT IT APPEARS BETTER FOR FG WITH NEAR SURFACE MOISTURE
VERY SHALLOW WITH CONTINUED WAA OVER THE TOP. LESS CLOUDS AROUND
WILL INHIBIT RADIATIONAL COOLING AND WINDS TO DROP TO LESS THAN 5
KTS AGAIN SAT NIGHT/SUN MORNING.
05/
&&
.UPDATE...
THE WINTER WEATHER ADVISORY HAS BEEN ALLOWED TO EXPIRE AT 6 PM AS
SCHEDULED. THE UPPER LEVEL FEATURE RESPONSIBLE FOR THE
PRECIPITATION CAN BE SEEN ON WATER VAPOR IMAGERY SWINGING EAST
ACROSS TEXAS...WHILE RADAR INDICATES PRECIPITATION COMING TO AN
END OVER OUR EASTERN COUNTIES. WE WILL STILL LEAVE THE MENTION OF
FLURRIES OVER NORTHEASTERN COUNTIES...AND A SLIGHT CHANCE OF
FREEZING RAIN OR SLEET OVER THE EASTERN COUNTIES SOUTH OF
INTERSTATE 20...WHERE PRECIPITATION MAY LINGER FOR A FEW MORE
HOURS.
THE NEXT THING TO WATCH FOR WILL BE THE POSSIBILITY OF FOG
DEVELOPMENT OVERNIGHT AS TEMPERATURES COOL AND CLOUDS ERODE FROM
WEST TO EAST. FOR NOW WE WILL STICK WITH PATCHY FOG...FEELING THAT
SOUTH WINDS AROUND 5 MPH WILL MIX THE LOWER ATMOSPHERE ENOUGH TO
INHIBIT DENSE FOG DEVELOPMENT. IF FOG DOES BECOME MORE DENSE OR
MORE WIDESPREAD THAN EXPECTED...WE WOULD NEED TO CONSIDER A FREEZING
FOG ADVISORY FOR THOSE AREAS AFFECTED. HOPEFULLY FOG WILL REMAIN
PATCHY AND LIGHT...BUT STAY TUNED TO THE LATEST UPDATES A WE HEAD
INTO THE OVERNIGHT HOURS.
30
&&
.PREV DISCUSSION... /ISSUED 316 PM CST FRI FEB 7 2014/
STRONG UPPER LEVEL SHORTWAVE IS CURRENTLY MOVING ACROSS THE REGION
AND WILL RAPIDLY MOVE EAST OF THE AREA TONIGHT. A BAND OF SNOWFALL
HAS DEVELOPED ACROSS THE NORTHWEST AND NORTHERN ZONES TODAY AND
THIS BAND WILL CONTINUE TO MOVE GENERALLY EAST. SO FAR MEASURABLE
SNOW HAS BEEN CONFINED THE REGION FROM OLNEY TO BOWIE TO
SHERMAN...WITH THE SOUTHERN PART OF THE ADVISORY FOR SNOW NOT
SEEING MUCH OF ANYTHING. WE MAY CANCEL A FEW OF THESE SOUTHERN
COUNTIES EARLY BASED ON RADAR TRENDS AND EXTRAPOLATION OF THE DRY
SLOT THAT WILL BE ROTATING IN FROM THE SOUTHWEST SHORTLY.
ACROSS THE CENTRAL CWA...INCLUDING THE METROPLEX...THE STRONG
FORCING IS SQUEEZING OUT A FEW SNOW GRAINS/FLURRIES/SLEET
PELLETS...BUT LITTLE OR NO ACCUMULATION IS EXPECTED FROM THIS VERY
LIGHT ACTIVITY.
SOME SHORT TERM MODELS CONTINUE TO SUGGEST CONDITIONAL SYMMETRIC
INSTABILITY WILL BECOME AVAILABLE FOR SLANTWISE CONVECTION OVER
THE NORTHEAST ZONES BETWEEN 4 PM AND 7 PM...BUT SINCE AGREEMENT IS
POOR THERE IS NOT ENOUGH CONFIDENCE TO EITHER CANCEL THE ADVISORY
OVER THE NORTHEAST ZONES EARLY OR EXTEND IT THROUGH 8 OR 9 PM.
WILL KEEP THE ADVISORY GOING THROUGH 6 PM AND WATCH TRENDS TO MAKE
THE CALL ON THAT. SO YES IT IS POSSIBLE A BATCH OF SNOW/SLEET WILL
DEVELOP OVER THE NORTHEAST AND FAR EAST ZONES...WHICH WILL
NECESSITATE EXTENDING THE ADVISORY THERE THROUGH 9 PM OR SO.
ACROSS SOUTHERN AND SOUTHEAST ZONES...THE ADVISORY FOR FREEZING
DRIZZLE CONTINUES AS WELL. THE HEAVIER AND ACCUMULATING FREEZING
DRIZZLE HAS MOVED OFF TO THE NORTHEAST AND WEATHER CONDITIONS HAVE
IMPROVED A BIT ACROSS CENTRAL TEXAS...BUT RADAR SHOWS ONE MORE
BATCH OF DRIZZLE IS MOVING UP FROM SOUTH CENTRAL TEXAS. HOWEVER
SURFACE TEMPERATURES ARE BEGINNING TO WARM ABOVE FREEZING ACROSS
THE FAR SOUTHEAST ZONES. WILL LIKELY CLEAR A FEW SOUTHEASTERN MOST
COUNTIES FROM THE ADVISORY A LITTLE EARLY...BUT BELL AND MCLENNAN
COUNTIES WILL CONTINUE THROUGH 6 PM.
ALL PRECIPITATION WILL SHUT DOWN RAPIDLY FROM WEST TO EAST AS THE
SHORTWAVE CLEARS THE AREA EARLY TO MID EVENING. CLOUDS WILL ALSO
ATTEMPT TO CLEAR FROM WEST TO EAST...BUT THIS CLEARING WILL LOSE
ITS GUSTO AS THE LOW LEVEL INVERSION WILL BE FAIRLY STOUT EAST OF
I-35. IN AREAS WHERE IT CLEARS...CONTINUED TOP DOWN DRYING VIA
SUBSIDENCE ALOFT WILL ENHANCE RADIATIONAL COOLING. THIS MAY ALLOW
AREAS OF FOG TO DEVELOP LATER TONIGHT. WITH TEMPERATURES BELOW
FREEZING...FOG IF IT BECOMES DENSE ENOUGH WOULD RESULT IN SOME ICE
ACCRETION. SINCE SOUTH WINDS INCREASE TO NEAR 5 MPH...IT MAY BE
TOO WINDY FOR THIS FOG TO BECOME DENSE ENOUGH FOR A FREEZING FOG
RISK. WILL NOT FORECAST FREEZING FOG YET...AND THE OVERNIGHT
SHIFT CAN WATCH THE TRENDS CLOSELY.
ASIDE FROM MORNING FOG...GENERALLY SUNNY SKIES ARE EXPECTED OVER
THE AREA TOMORROW. SOUTHWEST WINDS WILL ALSO HELP TO BOOST TEMPS
INTO THE 50S...WITH SOME 60S ACROSS THE SOUTHWEST ZONES. ANOTHER
COOL AND TRANQUIL NIGHT IS EXPECTED SATURDAY NIGHT. MODEL DATA IS
SHOWING STRONG SIGNALS FOR DENSE FOG SATURDAY NIGHT INTO SUNDAY
MORNING NORTH OF I-20. AGAIN THERE IS A CONCERN THAT WITH TEMPS
NEAR OR BELOW FREEZING...FREEZING FOG COULD OCCUR.
ON SUNDAY THE NEXT FRONT WILL BE ORGANIZING OVER THE SOUTHERN
PLAINS AND WILL BEGIN TO MOVE SOUTH THROUGH THE AREA. WITH A FOGGY
START ACROSS THE NORTHERN ZONES...AND FRONTAL PASSAGE AROUND
MIDDAY THERE...THIS MEANS TEMPS WILL LIKELY REMAIN FAIRLY CHILLY.
ACROSS THE SOUTHERN ZONES...SUNNY SKIES AND SOUTHWEST WINDS MEANS
TEMPS WILL SOAR TO NEAR 70 DEGREES. THE COLD FRONT WILL PUSH
THROUGH SUNDAY EVENING ACROSS THE SOUTHERN HALF OF THE AREA WITH
TEMPS TUMBLING BACK INTO THE 30S.
THE SUNDAY FRONT WILL BE VERY SHALLOW INITIALLY WITH NEARLY
SATURATED LOW LEVELS AND WEAK ISENTROPIC LIFT UP AND OVER THE COLD
DOME. BY SUNDAY NIGHT AND MONDAY MORNING...DRIZZLE IS EXPECTED TO
DEVELOP BEHIND THE FRONT. AS TEMPS DROP BELOW FREEZING ACROSS THE
NORTHWESTERN PARTS OF THE AREA NEAR DAYBREAK MONDAY MORNING...THIS
DRIZZLE WOULD POSE A LIGHT ICING RISK. THE FRONTAL LAYER WILL
DEEPEN AND DRY OUT MONDAY AFTERNOON AND EVENING...WITH DRIZZLE OR
RAIN CHANCES LIKELY ENDING. HOWEVER BY TUESDAY MORNING THE NEXT
SHORTWAVE WILL BE APPROACHING THE AREA WITH MORE SIGNIFICANT
ISENTROPIC LIFT SPREADING ACROSS THE REGION.
MODEL GUIDANCE GENERALLY HAS TRENDED TOWARD THE ECMWF FORECAST OF
THE LAST FEW DAYS WITH A WEAKER SHORTWAVE AND A MORE SOUTHERLY
TRACK. THE FRONTAL BAROCLINIC ZONE WILL PUSH WELL SOUTH OF THE
REGION WITH THE COLD FRONT...AND THAT SUPPORTS A MORE SOUTHERLY
TRACK OF THIS UPPER LEVEL ENERGY. HIGHEST POPS WILL BE ACROSS THE
SOUTHERN ZONES WHERE THE MORE SIGNIFICANT PRECIPITATION IS
EXPECTED. MODEL GUIDANCE ACROSS THE SOUTHERN HALF OF THE AREA IS
FORECASTING THE PRECIP TYPE TO REMAIN A COLD RAIN. ACROSS THE
NORTHERN HALF OF THE CWA...PRECIP AMOUNTS SHOULD BE ON THE LIGHT
SIDE...BUT THERMAL PROFILES WOULD BE COLD ENOUGH TO SUPPORT A
WINTER MIX. RIGHT NOW THERE ARE NO SIGNS THAT THIS WILL BE A MAJOR
WINTER STORM...BUT ANY LIGHT WINTRY PRECIP WILL CAUSE SOME ISSUES.
IN THE WAKE OF THE TUESDAY SYSTEM...RAPID DRYING AND WARMING WILL
OCCUR WEDNESDAY AND THURSDAY. THE UPPER LEVEL PATTERN LOOKS TO
SHIFT NEXT WEEK WITH A MORE PROGRESSIVE LONGWAVE PATTERN. THE JET
STREAM SHOULD MOVE FARTHER NORTH AS AN UPPER RIDGE OVER THE
SUBTROPICAL EASTERN PACIFIC INTENSIFIES. THIS SHOULD KEEP THE
ARCTIC AIR BOTTLED UP IN CANADA AS LOW PRESSURE SYSTEMS BEGIN TO
TRACK ALONG THE CANADIAN/US BORDER. FOR NORTH TEXAS WE WILL LIKELY
SEE FREQUENT MID-FEBRUARY PACIFIC FRONTS...BUT UNFORTUNATELY
RIDGING EXTENDING UP THROUGH THE SONORA DESERT WILL PUT US IN A
DRIER FLOW ALOFT. RAIN CHANCES LOOK MINIMAL...BUT TEMPERATURES
SHOULD WARM TO NEAR OR ABOVE NORMAL.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 27 55 33 58 31 / 10 0 0 10 10
WACO, TX 26 64 37 70 36 / 10 0 0 10 10
PARIS, TX 26 49 30 55 35 / 10 0 0 10 10
DENTON, TX 25 50 29 53 30 / 10 0 0 10 10
MCKINNEY, TX 25 51 29 55 31 / 10 0 0 10 10
DALLAS, TX 28 55 35 59 31 / 10 0 0 10 10
TERRELL, TX 27 55 33 61 33 / 10 0 0 10 10
CORSICANA, TX 28 59 38 65 36 / 10 0 0 5 10
TEMPLE, TX 26 64 39 72 37 / 10 0 0 5 10
MINERAL WELLS, TX 24 56 31 56 30 / 5 0 0 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/30
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1137 PM EST FRI FEB 7 2014
.SYNOPSIS...
HIGH PRESSURE DEPARTS TONIGHT. AN AREA OF LOW PRESSURE WILL
DEVELOP OFF THE SOUTHEAST COAST THROUGH SATURDAY...WITH AN UPPER
LEVEL DISTURBANCE ALSO CUTTING ACROSS VIRGINIA AND NORTH CAROLINA. A
REINFORCING SHOT OF COLDER AIR ARRIVES SUNDAY NIGHT AND
MONDAY...WITH ANOTHER SYSTEM POTENTIALLY MOVING ALONG THE LEADING
EDGE OF COLDER AIR...INTO WESTERN NORTH CAROLINA AND SOUTHWESTERN
VIRGINIA ON MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 950 PM EST FRIDAY...
MID AND HIGH CLOUDS CONTINUED TO FILL IN FROM THE SOUTHWEST THIS
EVENING. 00Z SOUNDINGS SHOWED THERE IS STILL SOME DRY AIR TO
OVERCOME BEFORE PRECIPITATION BEGINS. 18Z WRF...LATEST RUC AND
LATEST HRRR DO NOT HAVE THE SNOW BEGINNING IN THE FAR WESTERN
COUNTY WARNING AREA UNTIL AFTER 08Z/3AM AND SPREADING AT LEAST AS
FAR EAST AS THE ALLEGHANY HIGHLANDS AND NEW RIVER VALLEY BY 7AM.
ANY SNOW ACCUMULATION BEFORE 7AM WILL BE LESS THAN ONE INCH.
HAVE LOWERED MINIMUM TEMPERATURES IN SEVERAL LOCATIONS BASED ON
9PM OBSERVATIONS AND GRIDDED LAMP GUIDANCE.
AS OF 304 PM EST FRIDAY...
MODELS RATHER CONSISTENT FROM LAST NIGHT`S RUN WITH REGARDS TO LIGHT
SNOW EVENT LATE TONIGHT AND PART OF SATURDAY MORNING. SOME CLOUDS
REMAINING THIS AFTERNOON HAS SERVED TO INCUBATE LOW LEVEL MOISTURE
AND NOT LET DEWPOINT DEPRESSIONS BECOME TOO LARGE. THIS HAS
IMPLICATIONS WITH REGARDS TO HOW MUCH VIRGA/QPF IS NEEDED TO
SATURATE THE LEVELS LATE TONIGHT...AND HOW MUCH PRECIP ACTUALLY
MAKES IT TO THE GROUND. THE HIGHEST ELEVATIONS WILL BE MORE MOIST
SO THIS WILL NOT BE MUCH OF AN ISSUE. NONETHELESS...WITH ONLY
BETWEEN 0.02" AND 0.10" OF LIQUID FORECAST...IT MAY ONLY MEAN THE
DIFFERENCE BETWEEN A TRACE OF ACCUM AND A HALF INCH MOST SPOTS.
GROUND IS NOT SUPER COLD SO THAT MOST OF THE SNOW MAY IN FACT MELT
ALONG THE ROADS...EXCEPT ACROSS THE HIGHER ELEVATIONS...RESERVING
MOST LIGHT ACCUMS TO THE GRASS.
STILL THINK THERE WILL BE A SPLIT BETWEEN THE MOISTURE THAT IS NW
OF THE COASTAL LOW...AND THE SNOW THAT IS PRODUCED FROM THE UPPER
LEVEL SYSTEM. COULD SEE PARTS OF THE NEW RIVER VALLEY AND SW VA
FALLING IN BETWEEN THESE TWO AREAS OF PRECIP...AND JUST ENDING UP
WITH FLURRIES. THAT AREA IS TOUGH TO PINPOINT...SO WE WILL JUST GO
WITH A FEW TENTHS JUST ABOUT EVERYWHERE.
MORE RECENTLY THE MODELS HAVE BEEN TARGETING THE VA
PIEDMONT/SOUTHERN SHENANDOAH REGION FOR JUST UNDER A TENTH OF
LIQUID TOMORROW MORNING...AND THIS COULD PUT DOWN A HALF INCH TO
AN INCH FOR THE NORTHEASTERN QUADRANT OF THE CWA. THERE ARE SOME
TOTAL 2 INCH AMOUNTS ACROSS THE NORTHERN HALF OF THE CWA ABOVE
3000 FEET.
THE SYSTEM DEPARTS QUICKLY AND WITH WIDESPREAD SINKING MOTION
SATURDAY AFTERNOON SOME CLEARING IS LIKELY...AND HIGH TEMPS WILL
BE MET LATE AFTERNOON. WITH PRECIP AROUND SATURDAY MORNING...WENT
WITH A SLOWER RISE IN TEMPS THAN DIURNAL WOULD SUGGEST FOR THAT
PART OF THE DAY. CLOUDS WILL REMAIN ACROSS SE WEST VA THROUGH
AFTERNOON WITH UPSLOPE FLOW GETTING UNDERWAY LATE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EST FRIDAY...
WITH START SATURDAY NIGHT OFF WITH A WEAK SYSTEM PASSING ACROSS THE
GREAT LAKES. THE SOUTHWESTERLY WINDS AHEAD OF THIS SYSTEM MAY DRAW
ENOUGH MOISTURE INTO THE MOUNTAINS FOR SOME UPSLOPE SNOW SHOWERS...
HOWEVER SOUTHWESTERLY FLOW IS NOT THE IDEAL WIND DIRECTION TO
PRODUCE WIDESPREAD ACCUMULATIONS AS THE FLOW RUNS PARALLEL TO THE
RIDGE LINES. MAY SEE BETTER ACCUMULATIONS AFTER SUNRISE SUNDAY AS
WIND FLOW SHIFTS MORE WESTERLY. EXPECT THESE SNOW SHOWERS TO TAPER
OFF SATURDAY AFTERNOON...WITH ABOUT AN INCH ACCUMULATION ACROSS
WESTERN GREENBRIER COUNTY...TAPERING DOWN TO A FEW TENTHS OF AN INCH
IN THE EASTERN HALF OF THE COUNTY INTO THE ALLEGHANY HIGHLANDS.
IT DOES NOT TAKE LONG FOR WINDS TO BACK SOUTHWESTERLY AGAIN SUNDAY
AFTERNOON AS OUR NEXT SYSTEM APPROACHES. BELIEVE WE WILL SEE A SHORT
LULL IN PRECIPITATION FOR OUR AREA DURING THE AFTERNOON...WHERE
DECREASING CLOUD COVER WILL HELP AFTERNOON TEMPERATURES WARM INTO
THE MID 30S ACROSS SOUTHEAST WEST VIRGINIA...UP TO NEAR 50 ACROSS
THE SOUTHSIDE.
SUNDAY EVENING IS THE POINT WHERE THE MODELS DEVELOP TIMING
DIFFERENCES CONCERNING OUR NEXT COLD FRONT APPROACHING FROM THE
WEST. THE GFS FORECAST MODEL IS FASTEST WITH THE FRONT...BRINGING IT
THROUGH OUR AREA SUNDAY EVENING...WHILE THE NAM AND THE ECMWF HANG
THE FRONT FURTHER NORTH...AND DRAG THE FRONT MORE SLOWLY ACROSS OUR
AREA LATE SUNDAY NIGHT/EARLY MONDAY. CONSIDERING THE NEARLY STRAIGHT
WEST TO EAST UPPER LEVEL FLOW...MORE INCLINED TO FOLLOW THE
NAM/ECMWF GUIDANCE. THE SLOW PASSAGE OF THE FRONT THROUGH OUR AREA
THROUGH MONDAY AFTERNOON ALSO OPENS OUR AREA FOR A HIGHER CHANCE OF
LIGHT SNOW NORTH OF HIGHWAY 460 MONDAY AFTERNOON...WITH A RAIN SNOW
MIX FURTHER SOUTH. BELIEVE THE FRONT WILL STALL ACROSS THE CAROLINAS
MONDAY EVENING...AND WILL THEREFORE KEEP A HIGHER CHANCE OF
PRECIPITATION IN THE FORECAST HEADING INTO THE OVERNIGHT HOURS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 325 PM EST FRIDAY...
HIGH PRESSURE IN THE OHIO VALLEY TUESDAY MORNING WILL BUILD
NORTHEAST TUESDAY AFTERNOON REACHING SOUTHERN NEW ENGLAND BY
WEDNESDAY MORNING. AN AREA OF LOW PRESSURE WILL DEVELOP IN THE GULF
TUESDAY AND LIFT NORTHEAST TUESDAY NIGHT INTO WEDNESDAY. THE GFS HAS
A FURTHER SOUTH POSITION AND TRACK WITH THE LOW CENTER COMPARED TO
THE ECMWF. THE 00Z ECMWF STILL DEVELOPS A COASTAL LOW OFF THE SOUTH
CAROLINA COAST WEDNESDAY EVENING AND LIFTS NORTHWARD ALONG THE
ATLANTIC COAST THURSDAY. IN CONTRAST...THE GFS PUSHES MOST OF THE
MOISTURE OFF INTO THE ATLANTIC OCEAN. THE ECMWF IS INDICATING THE
POTENTIAL FOR MORE ACCUMULATING SNOWS FROM WEDNESDAY INTO
THURSDAY. THE GFS HAS LIGHTER SNOW ACCUMULATIONS WITH THIS STORM.
LEANED POPS TOWARDS HPCGUIDE SHAPED BY PREFERRED AVERAGE OF THE
GLOBAL ENSEMBLE MEANS. KEPT THE HIGHEST POPS WEDNESDAY AFTERNOON
INTO THURSDAY. TOO MUCH VARIABILITY IN THE MODELS WITH THIS WINTER
STORM TO WORK OUT EXACT DETAILS AT THIS POINT.
THURSDAY INTO THURSDAY NIGHT...COASTAL LOW AND ITS ASSOCIATED COLD
FRONT WILL CONTINUE TO MOVE OUT INTO THE ATLANTIC OCEAN.
MEANWHILE...LOW PRESSURE WITH A TRAILING COLD FRONT WILL DROP
SOUTHEAST ACROSS THE GREAT LAKES. ON THE FRIDAY...THE COLD FRONT
WILL CONTINUE TO MOVE EAST AS HIGH PRESSURE BUILDS OVER THE MIDWEST.
TEMPERATURES WILL START COLD AND SLOWLY MODERATE TOWARDS THE END OF
THE WEEK. THEN...A COOLING TEND IS EXPECTED FOR THE END OF THE WEEK
INTO EARLY NEXT WEEK.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1130 PM EST FRIDAY...
REGIONAL OBSERVATIONS SHOWED LOWER VFR CEILINGS SPREADING INTO
THE AREA FROM THE SOUTHWEST. CEILINGS ARE EXPECTED TO REMAIN VFR
UNTIL AFTER 08Z/3AM AT KBLF AND KLWB.
EVENING SOUNDING AT RNK SHOWED THERE WAS STILL SOME DRY AIR TO
OVERCOME BEFORE THE PRECIPITATION BEGINS. MODERATE CONFIDENCE OF
IFR CIG/VIS IN -SN THAT MOVES TO LWB/BLF BETWEEN 09Z/4AM AND
15Z/10AM. QPF IS MOST CONCENTRATED OVER LWB...SO THEY HAVE THE
BEST CHANCE OF IFR CIG/VIS AND POSSIBLY MODERATE SNOW.
LIGHT SNOW WILL SPREAD EAST THROUGH THE MORNING...BUT SOME OF IT
MAY DRY UP AND FAIL TO IMPACT BCB/ROA/LYH GREATLY. LOW CONFIDENCE
OF A FEW HOURS OF MVFR CEILINGS AT THESE SITES. DAN WILL BE
NEARER TO THE PRECIP SHIELD ASSOCIATED WITH A COASTAL
SYSTEM. ALTHOUGH BEGINNING AS SNOW OR A RAIN/SNOW MIX...BOUNDARY
LAYER TEMPS WILL BE MARGINAL AND WARMING TO ALLOW FOR RAIN MIXING
BY NOON AT DAN.
FOR ALL SITES HIGH CONFIDENCE THAT THIS WILL BE A MOSTLY MORNING
EVENT WITH SOME CLEARING SATURDAY AFTERNOON EXCEPT LWB. CLOUDS
INCREASE AGAIN SATURDAY NIGHT AHEAD OF AN UPPER LEVEL DISTURBANCE
WHICH WILL REMAIN MOSTLY OVER THE OHIO VALLEY...BUT POSSIBLY
SPREADING SOME MVFR CIGS INTO LWB/BLF BY DAWN SUNDAY.
EXTENDED AVIATION DISCUSSION...
FOR SUNDAY...AN UPPER LEVEL DISTURBANCE AND COLD FRONT WILL
BRING SNOW SHOWERS AND LIKELY MVFR CIGS WITH POSSIBLE IFR CIGS
LWB/BLF. DOWNSLOPE WIND FLOW SHOULD RESULT IN CLEARING EAST OF
THE MTNS WITH VFR BUT BREEZY CONDITIONS. GUIDANCE WAS RATHER
DIVERGENT ON HOW UPPER LEVEL ENERGY INTERACTS WITH THE FRONT
NEARBY OVER THE CAROLINAS...AND HOW FAR NORTH IT SPREADS WINTER
PRECIP INTO OUR REGION SUNDAY NIGHT AND MONDAY. THERE IS A CHANCE
FOR WIDESPREAD MVFR...AND POSSIBLE IFR...IF THIS SYSTEM MOVES
ALONG THE VA/NC BORDER.
ALTHOUGH SURFACE HIGH PRESSURE BRINGS TRANQUIL BUT COLD WEATHER
BACK FOR TUESDAY...IT`S EVENTUAL POSITION OVER SE CANADA OR NEW
ENGLAND MAY PROVIDE A COLD DOME FOR WHICH GULF OF MEXICO MOISTURE
IS ABLE TO OVERSPREAD NEXT WEDNESDAY....WITH AT LEAST A CHANCE FOR
WIDESPREAD IFR CONDS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KM/RAB
NEAR TERM...AMS/KM
SHORT TERM...NF
LONG TERM...KK
AVIATION...AMS/KM
AREA FORECAST DISCUSSION
NWS SPOKANE WA
921 PM PST Fri Feb 7 2014
.SYNOPSIS...
The next storm system will spread light snow across far southern
Washington and the lower Idaho Panhandle tonight into Saturday morning.
There will be chances for wintry precipitation through much of
next week. Temperatures will moderate back to seasonal readings.
&&
.DISCUSSION...
As low pressure system brings clouds and snow and passes quite
close to the southern edge of the forecast area the locations to
the north are still quite void of clouds and have a cold air mass
along with snow on the ground. This has caused the minimum
forecast temperatures for tonight to be complex, and as such have
updated again to cool them further north and this time the cooling
has impacted the zone wording enough to warrant an update.
Otherwise per most models and a number of recent HRRR model runs
the winter weather advisory highlighting the accumulating snow to
the south remains valid. /Pelatti
&&
.AVIATION...
06Z TAFS: Low pressure system passage skirting across the southern
edge of the aviation area will impact KLWS and KPUW with snow
tonight into tomorrow producing IFR ceilings and visibilities while
most other aviation locations further north will likely not have
any snow from it but may have radiation fog and low stratus
primarily during the overnight and early morning hours. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 4 22 9 24 18 28 / 10 30 10 30 40 60
Coeur d`Alene -1 23 9 25 19 31 / 10 20 10 30 40 60
Pullman 13 24 14 28 22 32 / 20 70 20 40 50 60
Lewiston 16 30 22 33 28 37 / 70 80 40 40 40 50
Colville 1 27 9 28 17 33 / 10 10 10 20 30 60
Sandpoint 5 24 10 25 19 31 / 10 10 10 20 30 60
Kellogg 6 24 12 27 21 32 / 10 40 30 40 60 70
Moses Lake 9 25 14 26 18 30 / 20 50 20 20 30 40
Wenatchee 12 24 16 27 20 31 / 20 60 20 30 30 30
Omak 4 26 12 27 19 31 / 10 10 0 10 20 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST Saturday for Lewis and
Southern Nez Perce Counties-Lewiston Area.
WA...Winter Weather Advisory until 10 AM PST Saturday for Lower
Garfield and Asotin Counties-Northeast Blue Mountains.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
448 AM MST SAT FEB 8 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 411 AM MST SAT FEB 8 2014
FORECAST CONCERNS WILL BE CHANCES OF PRECIPITATION AND HIGH
TEMPERATURES INTO THE BEGINNING OF NEXT WEEK. SATELLITE SHOWING A
CHANGING FLOW PATTERN FROM THE PACIFIC INTO NORTH AMERICA. FLOW
OVER THE WESTERN AND CENTRAL PACIFIC REMAINS AMPLIFIED AND
RETROGRESSIVE. SINCE THE LARGE UPPER RIDGE AND TROUGH HAVE PULLED
FURTHER WEST...THIS HAS ALLOWED A NEARLY ZONAL AND FAST/PROGRESSIVE
FLOW TO DEVELOP FROM THE EASTERN PACIFIC INTO THE ATLANTIC. NUMEROUS
SHORTWAVE TROUGHS AND A LARGE AMOUNT OF MID AND UPPER LEVEL MOISTURE
ARE EMBEDDED WITHIN THIS FLOW. LOW LEVEL AIR MASS HAS MODIFIED OVER
THE LAST 24 HOURS. HOWEVER...THE EXTENSIVE SNOWFIELD AND CLOUD COVER
CONTINUE TO HOLD DOWN TEMPERATURES TO BELOW NORMAL.
AT JET LEVEL...MODELS INITIALIZED FINE AT JET LEVEL. AT MID
LEVELS...MODELS INITIALIZED WELL WITH THE ECMWF...UKMET...CANADIAN
AND GFS DOING THE BEST. THE ECMWF WAS DOING THE BEST ON THE SURFACE
WIND PRESSURE FIELD. IT WAS HANDLING THE SURFACE TROUGH TO OUR WEST
VERY WELL. THE ECMWF WAS DOING A LITTLE BETTER THAN THE GFS ON THE
LOW LEVEL THERMAL FIELD. THE NAM WAS DOING THE WORST. MODELS TENDED
TO NOT HAVE THE COLD AIR FAR ENOUGH SOUTH AND WEST OVER THE CENTRAL
PLAINS.
TODAY/TONIGHT...INITIAL PROBLEM WILL BE FOG AND STRATUS TO THE EAST
OF SURFACE TROUGH. HRRR AND RAP HAVE A GOOD HANDLE ON WHAT IS GOING
ON. BOTH OF THESE ARE SHOWING FOG IN THE SOUTHEAST AND EASTERN
PORTION THROUGH LATE MORNING. LEFT FRONT QUADRANT OF JET MOVES
INTO/ACROSS THE AREA IN THE AFTERNOON WHICH IS SLOWER THAN YESTERDAY.
AT THIS TIME...ONLY MID AND UPPER LEVEL CLOUD COVER IS ASSOCIATED
WITH THIS FEATURE. THIS FEATURE MOVES NORTH AND EAST OF THE AREA BY
LATE EVENING.
THERE IS LITTLE TO NO MOISTURE WITH THIS INITIAL JET AND MID LEVEL
LIFT. SO KEPT FLURRIES IN THIS AREA. STRONG COLD FRONT BLASTS INTO
THE AREA DURING THE EVENING. ANOTHER LEFT FRONT QUADRANT OR JET AXIS
MOVES INTO OR OVER THE SOUTHWEST PORTION VERY QUICKLY AFTER MIDNIGHT.
DEPENDING ON WHICH MODEL YOU USE...IT IS POSSIBLE THAT A COUPLED JET
STRUCTURE COULD BE OVER THE AREA...ESPECIALLY FOR THE NORTHEAST
PORTION BY 12Z. DEEPER MOISTURE AND COLD AIR ESTABLISHES ITSELF
THROUGH THE NIGHT WITH THE BEST MOISTURE AFTER 06Z AND IN THE FAR
NORTH.
SOUNDINGS...MOISTURE DEPTH AND LIFT SUPPORT GOING CHANCE IN THE NORTH
AND THEN TAPERING OFF TO SLIGHT CHANCE AND FLURRIES IN THE FAR
SOUTH. PRIOR TO THE AIR MASS GETTING COLD ENOUGH AND GETTING THE
DEEPER MOISTURE...THE STRONG UPSLOPE FLOW...SOUNDING PROFILE...AND
MORE THAN ONE MODEL INDICATE THAT FOG WILL DEVELOP BEHIND THE FRONT
SO ADDED THAT IN.
TRICKY HIGH TEMPERATURE FORECAST AS MODEL DIFFERENCES CONTINUE. ONE
TREND THAT HAS OCCURRED SINCE YESTERDAY IS THEY ARE WARMER...
ESPECIALLY IN THE SOUTHWEST HALF. PER INITIAL ANALYSIS AND
CONSISTENCY BELIEVE THE ECMWF HAS THE RIGHT IDEA ON THE ARRIVAL OF
A PRESSURE/COOL SURGE BY LATE MORNING. MOST OF THE NORTH AND EAST
WILL REMAIN IN THE COOL AIR WITH LIGHT WINDS...SNOW COVER...
LINGERING LOW LEVEL CLOUD COVER AND INCREASING MID/UPPER LEVEL CLOUD
COVER. REMAINDER OF THE AREA GETS DOWNSLOPE WINDS. HOWEVER IT WILL
STILL HAVE TO CONTEND WITH THE MID/UPPER CLOUD COVER AND SNOWFIELD.
GOING BY WHAT WENT ON YESTERDAY WITH TEMPERATURES TO OUR WEST...
BELIEVE THE MODELS MAY BE TOO WARM. SO TENDED TO GO TOWARD THE
LOWER END OF GUIDANCE.
SUNDAY/SUNDAY NIGHT...ABOVE MENTIONED JET SHIFTS TO OVER THE
NORTHEAST PORTION OF THE AREA OR JUST TO THE NORTHEAST OF THE AREA BY
18Z AND CONTINUES TO MOVE SLOWLY NORTH THROUGH THE REST OF THE
AFTERNOON. SYNOPTIC AND MESOSCALE LIFT COMBINED WITH THE SOUNDINGS
SUPPORT HAVING NORTHEAST HALF HAVING THE HIGHEST CHANCE OF SNOW IN
THE MORNING. MOISTURE AND LIFT DECREASE A LITTLE IN THE AFTERNOON
BEFORE THE NEXT BATCH OF LIFT AND MOISTURE MOVE INTO THE AREA DURING
THE NIGHT. SO FOR THE AFTERNOON WILL HAVE A LOW CHANCE OF SNOW. COLD
AIR ADVECTION...UPSLOPE WINDS/CLOUD COVER AND PRECIPITATION WILL KEEP
THE TEMPERATURES FROM RISING MUCH AND LOWERED MAXES OR KEPT THEM
LOW. POSSIBLE THAT I STILL MAY BE TOO WARM.
RIGHT BEHIND FIRST JET COMES IN ANOTHER LEFT FRONT QUADRANT OF
ANOTHER JET. BY 06Z...THE GFS AND ECMWF ARE SHOWING A COUPLED JET
STRUCTURE WITH THE RIGHT REAR QUADRANT OF THE NORTHERN JET AND THE
LEFT FRONT QUADRANT OF THE NEW SOUTHERN JET COMING IN. THEY KEEP THIS
OVER THE AREA THROUGH THE REST OF THE NIGHT. MOISTURE DEPTH AND
SATURATION CONTINUE TO INCREASE AND REALLY IS THE BEST OUT OF ANY
SHORT TERM PERIOD. ALSO THE THETA-E LAPSE RATES ARE VERY CLOSE TO
ZERO. SO ALL THINGS CONSIDERED...RAISED POPS TO A HIGH CHANCE. POPS
MAY STILL NEED TO BE RAISED SOME MORE.
MONDAY/MONDAY NIGHT...ABOVE MENTIONED JET STRUCTURE OR RIGHT REAR
QUADRANT OF NORTHERN JET MOVE A LITTLE FURTHER SOUTH BY 18Z AND
CONTINUE TO AFFECT THE AREA...MOSTLY SOUTH. ABOVE MENTIONED JET LIFT
LOOKS TO MOVE SOUTH OF THE AREA DURING THE EVENING. SO KEPT SOME
CHANCE POPS IN THE MORNING WITH FLURRIES IN THE AFTERNOON. THE
NIGHT LOOKS DRY. NOTHING REALLY SHOWS VERY MUCH WARMING FOR MAXES.
SO LOWERED MAXES FROM PREVIOUS FORECAST. HOWEVER...CONSIDERING THE
VERY COLD AIR IN PLACE AND A LINGERING SNOW FIELD...ADDITIONAL
COOLING OF MAXES MAY BE NEEDED.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 411 AM MST SAT FEB 8 2014
FOR THE MOST PART THIS PERIOD WILL REMAIN DRY EXCEPT FOR THURSDAY
NIGHT AS A SUBTLE UPPER LEVEL SHORT WAVE TROUGH AND A PLUME OF
1000-500MB MOISTURE MOVE ACROSS THE AREA. OTHERWISE MODELS DISAGREE
WITH THE PROGRESSION OF THE TWO UPPER LEVEL SHORT WAVE TROUGHS IN
THE NORTHWEST FLOW DURING THIS PERIOD...WHICH WILL AFFECT NOT ONLY
PRECIP. CHANCES BUT ALSO COLD FRONT ARRIVAL BOTH MID WEEK AND LATE
WEEK. AM NOT TOO CONFIDENT WITH PRECIP. CHANCES FOR THURS NIGHT BUT
THE MEAN OF THE GFS ENSEMBLE MEMBERS IS FAVORING THE ECMWF 500MB
PATTERN THURS. NIGHT. WITH ECMWF QPF FAVORING THE CONSENSUS OUTPUT
AM INCLINED TO GO WITH CONSENSUS WHICH PLACES PRECIP. CHANCES OVER
THE NORTHERN HALF OF THE AREA.
OTHERWISE GENERAL TREND IN TEMPERATURES WILL BE WARMER BEHIND WARM
FRONT THAT MOVES THROUGH TUESDAY...POSSIBLY WARMING A FEW DEGREES
ABOVE NORMAL BY THE END OF THE WORK WEEK. DUE TO DISCREPANCIES IN
FRONTAL TIMING AFTER TUESDAY...HARD TO TREND TEMPERATURES AWAY FROM
CONSENSUS OUTPUT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 444 AM MST SAT FEB 8 2014
VFR CONDITIONS AT BOTH SITES ARE EXPECTED FOR THE FIRST HALF OF
THE PERIOD. THEN A COLD FRONT WILL MOVE THROUGH DURING THE LATE
AFTERNOON AND EVENING. BEHIND THAT FRONT LOW CEILINGS AND FOG WILL
DEVELOP. BETWEEN 00Z AND 06Z...IFR CEILINGS AND MVFR VISIBILITIES
DUE TO FOG AND STRATUS ARE EXPECTED. IN ADDITION...LIGHT SNOW WILL
BE POSSIBLE AT OR NEAR KMCK BEGINNING AT 06Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS TOPEKA KS
523 AM CST Sat Feb 8 2014
...AVIATION UPDATE...
.SHORT TERM...(Today and Tonight)
Issued at 332 AM CST SAT FEB 8 2014
09Z water vapor imagery shows a general west to northwest flow
across the country with several weak waves within it. One shortwave
can be seen moving across IA with another right on its heels. At the
surface, a surface ridge to the east of the area is gradually
weakening with an area of low pressure gradually deepening over the
northern and central high plains. This has allowed relatively warmer
and more moist air to move into central and eastern KS.
For today the models show the isentropic lift associated with the
warm air advection pattern to gradually weaken. So think the light
flurries will end across eastern KS by mid morning. Overall with the
northwest flow persisting and the occasional weak disturbance moving
through it, it becomes difficult to rule out precip chances even
though forcing and vertical motion progged by the models would only
support light precipitation with mainly trace accumulations. Most
solutions now bring the next cold front through the area overnight
with some mid level frontogenesis. While moisture could be better
with the front, have left some slight chance pops in the forecast
late tonight in case a small band of light snow is able to form. Am
not to sure there will be more flurries tonight ahead of the front
as model forecast soundings show the better warm air advection
lifting above the stratus deck with little vertical motion within
the cloud. So think the better opportunity for precip will be driven
by any mid level frontogenesis along the frontal boundary. Temps
this morning have been gradually rising due to overcast skies and
weak warm air advection. Think the weak warm air advection will
persist through the day today with temps gradually rising. However
highs around 30 may be a little optimistic since the stratus is
likely to hang in through the day limiting insolation. Because of
this have trended temps down a degree or two with mid 20s expected
along the NEB state line and highs around 30 in east central KS.
Lows Sunday morning should fall into the teens as cold air advection
increases behind the front.
Wolters
.LONG TERM...(Sunday through Friday)
Issued at 332 AM CST SAT FEB 8 2014
Next chances of snow Sunday and Monday remain light overall with
minor changes made to the previous forecast. Model consistency
between runs due to the very active however weak flow pattern
continues to create difficulty in handling precipitation chances and
temperatures.
Within the active quasi zonal flow pattern, the next wave in a
series of embedded shortwave troughs is progged to impact the area
Sunday afternoon. Most guidance has been somewhat consistent in a PV
anomaly translating southeast across the northern plains into the
Great Lakes region. Strength and timing of this trough continues to
change between runs. The ECMWF is the most robust with another
progressive trough quickly following behind the first. This
particular wave is further south, resulting in stronger forcing and
much higher QPF values than all other guidance across our area.
Consensus though depicts this wave translating across the northern
plains instead so left in the lighter liquid precipitation values on
Sunday afternoon. Saturation is also in question as drier air
advecting southward keeps the column from complete saturation,
unless we reach wetbulb temperatures. The NAM would suggest little
to no precip for much of the area while models generate varying
amounts to decipher. Regardless of the above factors, believe weak
frontogenetical forcing and gradual saturation in the column will
result in light snowfall during the day. Highest chances were placed
mainly along and north of Interstate 70. Locations near the Nebraska
and Kansas border can expect snowfall accumulations near an inch
with lesser amounts anticipated further south. Left slight chances
for light snow Sunday evening with highest chances Monday as another
PV anomaly develops over the Rockies, tracking eastward into Kansas.
This system may produce snowfall up to an inch for areas south of
Interstate 70. Precipitation chances then come to an end by Monday
evening.
The passing wave to our north on Sunday will steepen the pressure
gradient and result in gusty north winds during the afternoon.
Steady cold air advection into the area under overcast skies should
drag highs back down in the upper teens to lower 20s before the
surface arctic high builds southward, falling temps to the single
digits Monday morning. Wind chill readings range from 5 to 12 below
zero. Center of the 1040 MB surface ridge gradually moves eastward
Monday with one final day of highs in the teens Tuesday morning and
lows in the single digits.
Forecast from Tuesday through Friday remains dry as moisture
availability is almost non-existent despite the active upper flow
pattern. Southerly flow returns on the backside of the ridge, where
a gradual warm up commences. Models may be too cool on Tuesday highs
dependent on how strong the southwest winds are. Temperatures should
definitely reach above freezing by Wednesday, increasing to the 40s
on Thursday and Friday as warm air advection increases from the southwest.
&&
.AVIATION...(For the 12Z TAFs through 12Z Sunday Morning)
Issued at 523 AM CST SAT FEB 8 2014
Low level inversion is expected to prevent stratus from mixing out
today. Even if it does the RAP and NAM show steep low level lapse
rates conducive for stratocu to form. So the forecast maintains MVFR
CIGS. There is some uncertainty in whether the CIG remains below
2KFT or rises above it. The RAP and NAM are fairly quick to lower
CIGS this afternoon, and I don`t have a good reason for this. Any
measurable precip look unlikely, but there may be a slight chance
overnight with the FROPA and some increasing frontogenesis.
However confidence in precip is to low to include in the forecast
at this time.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...Bowen
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
411 AM MST SAT FEB 8 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 411 AM MST SAT FEB 8 2014
FORECAST CONCERNS WILL BE CHANCES OF PRECIPITATION AND HIGH
TEMPERATURES INTO THE BEGINNING OF NEXT WEEK. SATELLITE SHOWING A
CHANGING FLOW PATTERN FROM THE PACIFIC INTO NORTH AMERICA. FLOW
OVER THE WESTERN AND CENTRAL PACIFIC REMAINS AMPLIFIED AND
RETROGRESSIVE. SINCE THE LARGE UPPER RIDGE AND TROUGH HAVE PULLED
FURTHER WEST...THIS HAS ALLOWED A NEARLY ZONAL AND FAST/PROGRESSIVE
FLOW TO DEVELOP FROM THE EASTERN PACIFIC INTO THE ATLANTIC. NUMEROUS
SHORTWAVE TROUGHS AND A LARGE AMOUNT OF MID AND UPPER LEVEL MOISTURE
ARE EMBEDDED WITHIN THIS FLOW. LOW LEVEL AIR MASS HAS MODIFIED OVER
THE LAST 24 HOURS. HOWEVER...THE EXTENSIVE SNOWFIELD AND CLOUD COVER
CONTINUE TO HOLD DOWN TEMPERATURES TO BELOW NORMAL.
AT JET LEVEL...MODELS INITIALIZED FINE AT JET LEVEL. AT MID
LEVELS...MODELS INITIALIZED WELL WITH THE ECMWF...UKMET...CANADIAN
AND GFS DOING THE BEST. THE ECMWF WAS DOING THE BEST ON THE SURFACE
WIND PRESSURE FIELD. IT WAS HANDLING THE SURFACE TROUGH TO OUR WEST
VERY WELL. THE ECMWF WAS DOING A LITTLE BETTER THAN THE GFS ON THE
LOW LEVEL THERMAL FIELD. THE NAM WAS DOING THE WORST. MODELS TENDED
TO NOT HAVE THE COLD AIR FAR ENOUGH SOUTH AND WEST OVER THE CENTRAL
PLAINS.
TODAY/TONIGHT...INITIAL PROBLEM WILL BE FOG AND STRATUS TO THE EAST
OF SURFACE TROUGH. HRRR AND RAP HAVE A GOOD HANDLE ON WHAT IS GOING
ON. BOTH OF THESE ARE SHOWING FOG IN THE SOUTHEAST AND EASTERN
PORTION THROUGH LATE MORNING. LEFT FRONT QUADRANT OF JET MOVES
INTO/ACROSS THE AREA IN THE AFTERNOON WHICH IS SLOWER THAN YESTERDAY.
AT THIS TIME...ONLY MID AND UPPER LEVEL CLOUD COVER IS ASSOCIATED
WITH THIS FEATURE. THIS FEATURE MOVES NORTH AND EAST OF THE AREA BY
LATE EVENING.
THERE IS LITTLE TO NO MOISTURE WITH THIS INITIAL JET AND MID LEVEL
LIFT. SO KEPT FLURRIES IN THIS AREA. STRONG COLD FRONT BLASTS INTO
THE AREA DURING THE EVENING. ANOTHER LEFT FRONT QUADRANT OR JET AXIS
MOVES INTO OR OVER THE SOUTHWEST PORTION VERY QUICKLY AFTER MIDNIGHT.
DEPENDING ON WHICH MODEL YOU USE...IT IS POSSIBLE THAT A COUPLED JET
STRUCTURE COULD BE OVER THE AREA...ESPECIALLY FOR THE NORTHEAST
PORTION BY 12Z. DEEPER MOISTURE AND COLD AIR ESTABLISHES ITSELF
THROUGH THE NIGHT WITH THE BEST MOISTURE AFTER 06Z AND IN THE FAR
NORTH.
SOUNDINGS...MOISTURE DEPTH AND LIFT SUPPORT GOING CHANCE IN THE NORTH
AND THEN TAPERING OFF TO SLIGHT CHANCE AND FLURRIES IN THE FAR
SOUTH. PRIOR TO THE AIR MASS GETTING COLD ENOUGH AND GETTING THE
DEEPER MOISTURE...THE STRONG UPSLOPE FLOW...SOUNDING PROFILE...AND
MORE THAN ONE MODEL INDICATE THAT FOG WILL DEVELOP BEHIND THE FRONT
SO ADDED THAT IN.
TRICKY HIGH TEMPERATURE FORECAST AS MODEL DIFFERENCES CONTINUE. ONE
TREND THAT HAS OCCURRED SINCE YESTERDAY IS THEY ARE WARMER...
ESPECIALLY IN THE SOUTHWEST HALF. PER INITIAL ANALYSIS AND
CONSISTENCY BELIEVE THE ECMWF HAS THE RIGHT IDEA ON THE ARRIVAL OF
A PRESSURE/COOL SURGE BY LATE MORNING. MOST OF THE NORTH AND EAST
WILL REMAIN IN THE COOL AIR WITH LIGHT WINDS...SNOW COVER...
LINGERING LOW LEVEL CLOUD COVER AND INCREASING MID/UPPER LEVEL CLOUD
COVER. REMAINDER OF THE AREA GETS DOWNSLOPE WINDS. HOWEVER IT WILL
STILL HAVE TO CONTEND WITH THE MID/UPPER CLOUD COVER AND SNOWFIELD.
GOING BY WHAT WENT ON YESTERDAY WITH TEMPERATURES TO OUR WEST...
BELIEVE THE MODELS MAY BE TOO WARM. SO TENDED TO GO TOWARD THE
LOWER END OF GUIDANCE.
SUNDAY/SUNDAY NIGHT...ABOVE MENTIONED JET SHIFTS TO OVER THE
NORTHEAST PORTION OF THE AREA OR JUST TO THE NORTHEAST OF THE AREA BY
18Z AND CONTINUES TO MOVE SLOWLY NORTH THROUGH THE REST OF THE
AFTERNOON. SYNOPTIC AND MESOSCALE LIFT COMBINED WITH THE SOUNDINGS
SUPPORT HAVING NORTHEAST HALF HAVING THE HIGHEST CHANCE OF SNOW IN
THE MORNING. MOISTURE AND LIFT DECREASE A LITTLE IN THE AFTERNOON
BEFORE THE NEXT BATCH OF LIFT AND MOISTURE MOVE INTO THE AREA DURING
THE NIGHT. SO FOR THE AFTERNOON WILL HAVE A LOW CHANCE OF SNOW. COLD
AIR ADVECTION...UPSLOPE WINDS/CLOUD COVER AND PRECIPITATION WILL KEEP
THE TEMPERATURES FROM RISING MUCH AND LOWERED MAXES OR KEPT THEM
LOW. POSSIBLE THAT I STILL MAY BE TOO WARM.
RIGHT BEHIND FIRST JET COMES IN ANOTHER LEFT FRONT QUADRANT OF
ANOTHER JET. BY 06Z...THE GFS AND ECMWF ARE SHOWING A COUPLED JET
STRUCTURE WITH THE RIGHT REAR QUADRANT OF THE NORTHERN JET AND THE
LEFT FRONT QUADRANT OF THE NEW SOUTHERN JET COMING IN. THEY KEEP THIS
OVER THE AREA THROUGH THE REST OF THE NIGHT. MOISTURE DEPTH AND
SATURATION CONTINUE TO INCREASE AND REALLY IS THE BEST OUT OF ANY
SHORT TERM PERIOD. ALSO THE THETA-E LAPSE RATES ARE VERY CLOSE TO
ZERO. SO ALL THINGS CONSIDERED...RAISED POPS TO A HIGH CHANCE. POPS
MAY STILL NEED TO BE RAISED SOME MORE.
MONDAY/MONDAY NIGHT...ABOVE MENTIONED JET STRUCTURE OR RIGHT REAR
QUADRANT OF NORTHERN JET MOVE A LITTLE FURTHER SOUTH BY 18Z AND
CONTINUE TO AFFECT THE AREA...MOSTLY SOUTH. ABOVE MENTIONED JET LIFT
LOOKS TO MOVE SOUTH OF THE AREA DURING THE EVENING. SO KEPT SOME
CHANCE POPS IN THE MORNING WITH FLURRIES IN THE AFTERNOON. THE
NIGHT LOOKS DRY. NOTHING REALLY SHOWS VERY MUCH WARMING FOR MAXES.
SO LOWERED MAXES FROM PREVIOUS FORECAST. HOWEVER...CONSIDERING THE
VERY COLD AIR IN PLACE AND A LINGERING SNOW FIELD...ADDITIONAL
COOLING OF MAXES MAY BE NEEDED.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 411 AM MST SAT FEB 8 2014
FOR THE MOST PART THIS PERIOD WILL REMAIN DRY EXCEPT FOR THURSDAY
NIGHT AS A SUBTLE UPPER LEVEL SHORT WAVE TROUGH AND A PLUME OF
1000-500MB MOISTURE MOVE ACROSS THE AREA. OTHERWISE MODELS DISAGREE
WITH THE PROGRESSION OF THE TWO UPPER LEVEL SHORT WAVE TROUGHS IN
THE NORTHWEST FLOW DURING THIS PERIOD...WHICH WILL AFFECT NOT ONLY
PRECIP. CHANCES BUT ALSO COLD FRONT ARRIVAL BOTH MID WEEK AND LATE
WEEK. AM NOT TOO CONFIDENT WITH PRECIP. CHANCES FOR THURS NIGHT BUT
THE MEAN OF THE GFS ENSEMBLE MEMBERS IS FAVORING THE ECMWF 500MB
PATTERN THURS. NIGHT. WITH ECMWF QPF FAVORING THE CONSENSUS OUTPUT
AM INCLINED TO GO WITH CONSENSUS WHICH PLACES PRECIP. CHANCES OVER
THE NORTHERN HALF OF THE AREA.
OTHERWISE GENERAL TREND IN TEMPERATURES WILL BE WARMER BEHIND WARM
FRONT THAT MOVES THROUGH TUESDAY...POSSIBLY WARMING A FEW DEGREES
ABOVE NORMAL BY THE END OF THE WORK WEEK. DUE TO DISCREPANCIES IN
FRONTAL TIMING AFTER TUESDAY...HARD TO TREND TEMPERATURES AWAY FROM
CONSENSUS OUTPUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1051 PM MST FRI FEB 7 2014
GLD WILL REMAIN VFR THROUGH THE MAJORITY OF THE TAF PERIOD. LIGHT
SOUTH TO SOUTHWEST WIND ARE EXPECTED WITH MID TO HIGH LEVEL CLOUDS
MOVING ACROSS THE REGION. LOWER CLOUDS AND VISIBILITIES AROUND 6
MILES WILL MOVE INTO THE REGION AFTER 04Z SATURDAY EVENING AS
WINDS BECOME LIGHT AND VARIABLE AHEAD OF THE APPROACHING COLD
FRONT.
MCK WILL BE VFR TROUGH AT LEAST 00Z SATURDAY EVENING AS MID TO
HIGH CLOUDS MOVE ACROSS THE AREA...LIGHT SOUTH WINDS TURN TO THE
NORTHWEST...AND CEILINGS BEGIN TO LOWER AS A COLD FRONT
APPROACHES THE REGION. BY 02Z...CONDITIONS ARE EXPECTED TO BE MVFR
WITH VISIBILITY DECREASING TO AROUND 3 MILES AND CEILINGS BECOMING
LESS THAN 2K FT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS JACKSON MS
436 AM CST SAT FEB 8 2014
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT. THE PRIMARY CONCERNS WILL
BE LIMITED RISK OF LIGHT WINTER PRECIPITATION IN THE NORTH UNTIL MID
MORNING...FOLLOWED BY THE CHANCE OF SOME COLD LIGHT RAIN FOR SUNDAY
NIGHT. LASTLY POPS AND TEMPS FOR THE PERIOD.
LATEST SATELLITE VAPOR IMAGERY SHOWED THE SHORT WAVE MOVING OVER THE
REGION EARLY THIS MORNING. THERE HAVE BEEN REPORTS OF SOME LIGHT
SNOW COMBINED WITH SOME SLEET AND LIGHT FREEZING RAIN ACROSS THE
NORTH OVERNIGHT. THIS HAS CAUSED SOME SLICK SPOTS ON BRIDGES AND
OVERPASSES. READINGS ACROSS THE REGION WERE GENERALLY FROM THE LOWER
30S NORTH TO THE LOWER 40S SOUTHEAST. AREA RADAR SHOWS THAT THE MAIN
AREA OF PRECIPITATION WAS EXITING THE EAST. THERE WAS SOME PATCHY
LIGHT RETURNS OVER LOUISIANA...ASSOCIATED WITH THE SHORT WAVE MOVING
TOWARD THE ARKLAMISS.
FOR THIS MORNING THE HRRR AND LOCAL WRF SHOWS SOME LIGHT RADAR
RETURNS ACROSS THE REGION UNTIL AROUND MID MORNING. SO WITH COOL
TEMPS THIS MORNING HAVE OPTED TO CONTINUE THE WINTER WEATHER
ADVISORY UNTIL 9 AM THIS MORNING. DO NOT EXPECT MUCH IN ANY
ACCUMULATION OF WINTER PRECIP...BUT WITH SLICK SPOTS ON BRIDGES AND
OVERPASSES IN THE NORTH WILL CONTINUE ADVISORY UNTIL MIDMORNING WHEN
TEMPS RISE ABOVE FREEZING. SO WILL PUT IN TEEN POPS SINCE COVERAGE
WILL BE VERY LIMITED WITH THE PASSAGE OF THE SHORT WAVE. THE
SHORTWAVE WILL EXIT THE REGION BY THIS AFTERNOON AS SKIES BECOME
PARTLY CLOUDY AND DRYER AIR ADVECTS INTO THE REGION. HIGHS TODAY
WILL BE FROM THE LOWER 40S NORTHWEST TO THE MIDDLE 50S SOUTHEAST.
FOR TONIGHT THROUGH SUNDAY....EXPECT A DRYER PATTERN FOR THE PERIOD
AS WE START TO GET A GRADUAL WARMING TREND FOR SUNDAY AS WE WILL
START TO GET SOME LOW LEVEL WARM AIR ADVECTION. LOWS TONIGHT WILL BE
FROM THE LOWER 30S NORTH TO THE LOWER 40S SOUTHWEST. FOR SUNDAY LOW
LEVEL WARM ADVECTION WILL KICK IN AS WE GET HIGHS FROM THE LOWER 50S
NORTHWEST TO THE MIDDLE 60S SOUTHEAST. THIS WILL BRING ABOVE NORMAL
TEMPS ACROSS THE SOUTH HALF.
FOR SUNDAY NIGHT...A WEAK SHORT WAVE BRINGS SOME PATCHY LIGHT RAIN
TO THE REGION. THE NAM...EURO...UK...CANADIAN AND SREF SHOW SOME
LIGHT RAIN COMING INTO THE REGION...WHILE THE GFS WAS DRY. SO WITH
WARM AIR ADVECTION OPTED TO GO WITH THE WARMER GUIDANCE AND KEEP IT
JUST COOL LIGHT RAIN. LOWS FOR SUNDAY NIGHT WILL BE FROM THE MIDDLE
30S NORTHWEST TO THE MIDDLE 40S SOUTHEAST.
AS FAR AS TEMPS ARE CONCERN WENT WITH THE NAM GUIDANCE ON COOLER
TEMPS FOR TODAY WITH MORNING CLOUDS AND SOME LIGHT MORNING WINTER
PRECIP AROUND. FOR TONIGHT WENT CLOSE TO MAV GUIDANCE. FOR SUNDAY
WENT CLOSER TO THE MILDER GMOS GUIDANCE. FOR SUNDAY NIGHT WENT WITH
A MILDER BLEND OF THE NAM AND MAV GUIDANCE.
AS FAR AS POPS ARE CONCERN WENT WITH LOW POPS DUE TO LIMITED RADAR
COVERAGE APPROACHING FROM LOUISIANA. FOR SUNDAY NIGHT USED A BLEND
OF WET NAM AND DRY MAV GUIDANCE FOR LOW END POPS.
.LONG TERM...MONDAY THROUGH SATURDAY...A RATHER WET AND WINTRY LONG
TERM LOOKS ON TAP FOR THE ARKLAMISS. A COOL CLOUDY DAMP DAY WILL
PREVAIL ACROSS THE ARKLAMISS ON MONDAY AS COLD AIR ADVECTION
PREVAILS...BUT INCREASING ISENTROPIC LIFT THROUGH THE DAY WILL BRING
A CHANCE FOR LIGHT RAIN. MOISTURE AND ISENTROPIC LIFT WILL CONTINUE
TO INCREASE MONDAY EVENING AS A STRONGER SHORT WAVE BEGINS TO MOVE
INTO THE DELTA. THIS COMBINED WITH COOLING TEMPERATURES WILL INCREASE
CHANCES FOR SNOW ACROSS THE NORTHERN PORTIONS OF THE AREA. THE
GFS/ECMWF ARE IN DECENT AGREEMENT ON THIS WITH THE GFS EVEN COLDER
THAN THE ECMWF MONDAY NIGHT. BOTH MODELS ARE COLD ENOUGH TO SUPPORT
MAINLY SNOW ACROSS THE HWY 82 CORRIDOR OVERNIGHT TRANSITIONING TO
MORE OF A MIXED BAG FURTHER SOUTH AND MAINLY RAIN ALONG AND SOUTH OF
THE I-20 CORRIDOR. THE GFS BUFR SOUNDINGS WOULD INDICATE THE
POTENTIAL FOR SOME -FZRA ALONG THE I-20 CORRIDOR BY EARLY
TUESDAY...BUT THE ECMWF IS WARMER SO WILL HOLD OFF ON THE MENTION OF
THIS IN THE FORECAST FOR NOW.
A WINTRY MIX LOOKS LIKELY TO CONTINUE ON TUESDAY FOR AREAS NORTH OF
THE I-20 CORRIDOR WITH RAIN CONTINUING FURTHER SOUTH. THE MODELS
BEGIN TO WARM THE MID LAYERS LATE ON TUESDAY INTO TUESDAY NIGHT SO
EXPECT A TRANSITION TO MORE SLEET AND FREEZING RAIN DURING THIS
PERIOD FOR THE HWY 82 CORRIDOR WITH LIGHT RAIN CONTINUING FURTHER
SOUTH. BOTH OF THE GLOBAL MODELS INDICATE WARMER TEMPERATURES ON
WEDNESDAY...THUS EXPECT A CHANCE FOR MAINLY LIGHT RAIN ACROSS THE
AREA. THE GFS/ECMWF DIFFER ON THERE SOLUTIONS ON WEDNESDAY INTO
WEDNESDAY NIGHT WITH THE ECMWF ENDING THE PRECIP DURING THE
AFTERNOON HOURS WHILE THE GFS LINGERS LIGHT RAIN ACROSS THE AREA
THROUGH WEDNESDAY NIGHT. WILL DIFFER TO THE DRIER ECMWF AND END THE
LIGHT RAIN BY WEDNESDAY EVENING.
BOTH THE GFS/ECMWF SUGGEST A WARMER PERIOD LATER IN THE WEEK AND
INTO THE WEEKEND WITH ANOTHER COLD FRONT BRINGING SHOWERS TO THE AREA
ON SATURDAY. STUCK PRETTY CLOSE TO GUIDANCE TEMPS THROUGH THE
PERIOD...BUT DID CUT BELOW GUIDANCE HIGHS ON TUESDAY. ALSO STUCK
PRETTY CLOSE TO GUIDANCE POPS THROUGH THE PERIOD...BUT DID CUT POPS
BELOW GUIDANCE WEDNESDAY NIGHT TO END THE LIGHT RAIN./15/
&&
.AVIATION...PRIOR TO DAWN MOSTLY GENERALLY VFR CONDITIONS WAS NOTED
ACROSS THE REGION. AREA RADARS WERE SHOWING THE MAIN AREA OF PRECIP
EXITING THE REGION. EXPECT ONLY SPOTTY COVERAGE FOR EARLY THIS
MORNING FROM THE WEST. WILL BRIEFLY MENTION -FZRA ACROSS THE
NORTHERN TAFS FOR EARLY THIS MORNING BEFORE THE PRECIP ENDS BY LATE
MORNING. OTHERWISE EXPECT VFR CONDITIONS FOR THE REST OF THE DAY./17/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 50 37 61 44 / 15 4 2 20
MERIDIAN 50 35 63 43 / 17 6 1 18
VICKSBURG 50 37 60 43 / 15 3 3 21
HATTIESBURG 54 40 66 46 / 15 8 5 18
NATCHEZ 54 40 61 44 / 15 3 4 21
GREENVILLE 42 34 54 34 / 15 3 1 21
GREENWOOD 44 32 55 37 / 16 4 1 21
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR MSZ018-
019-025>042.
LA...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR
LAZ007>009.
AR...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR ARZ074-
075.
&&
$$
17/15/
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
617 AM CST SAT FEB 8 2014
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 300 AM CST SAT FEB 8 2014
TIMING/STRENGTH OF ANY POPS MAIN ISSUE...MAINLY TONIGHT AND
SUNDAY...WITH LINGERING LOW CLOUDS SOUTH TODAY AND MIN TEMPS BY
MONDAY MORNING OTHER CONCERNS.
ALTHOUGH LIGHT SNOW...MOSTLY FLURRIES...HAVE BEEN PREVALENT
OVERNIGHT...RADAR RETURNS HAD INCREASED SOMEWHAT AFTER 06Z IN
NERN ZONES. THIS IS IN ADVANCE OF COMPACT AND WELL DEFINED VORT
MAX OVER NCNTRL NEBR/SCNTRL SD VICINITY AT 07Z PER SATELLITE
IMAGERY. THIS DISTURBANCE WAS FORECAST TO BE EAST OF THE FORECAST
AREA BY 18Z THUS WOULD SUSPECT ANY MEASURABLE PRECIP NRN/ECNTRL
ZONES WOULD END FAIRLY QUICKLY THIS MORNING AND POSSIBLY EVEN BE
MOSTLY E OF FA BY 12Z. ALTHOUGH THIS SYSTEM WAS ALSO CLEARING OUT
LOW CLOUDS PARTS OF WRN/NRN NEBR...BUT WITH TRAILING MID/HIGH
CLOUDS...IT WAS HAVING LESS SUCCESS CLEARING LOW CLOUDS OUT
ACROSS THE SOUTH. SHORT RANGE HRRR BASICALLY LEFT THESE LOW CLOUDS
IN ALL DAY SO DELAYED CLEARING FAR SOUTH. ALSO WITH SLOWER
CLEARING PARTS OF THE EAST/SOUTH...LOWERED HIGHS A BIT.
LIKEWISE...RAISED MINS TO AROUND 10 SOUTH FOR TONIGHT AS COLD
ADVECTION ONLY MODEST BEHIND FRONT.
FAST UPPER FLOW WITH SEVERAL EMBEDDED WAVES AND TIMING/LOCATION
DIFFERENCES BETWEEN 00Z NAM/GFS AND ECMWF IN QPF PLACEMENT CREATE
A OVER-SMOOTHED OR OVER-SIMPLIFIED PRECIP FORECAST POTENTIAL. BUT
OTHER THAN GOING FOR AN ALL-OR-NOTHING BY FOLLOWING ONE
PARTICULAR MODEL...IT PROBABLY IS ABOUT THE BEST WAY TO HANDLE
IT. THUS...BROUGHT IN SMALL POPS WRN ZONES LATE THIS AFTN PER GFS
AND THEN INCREASED THEM TO CHC CATEGORY ACROSS A WIDE WEST TO
EAST SWATH THIS EVENING PER MODELS BUT ALSO MENTIONED SMALL
CHANCES N TO ACCOUNT FOR THE FARTHER N ECMWF. THEN FOR SUNDAY
INCREASED POPS BACK INTO CHC CATEGORY S USING MORE OF THE ECMWF.
A QUICK LOOK AT THE 06Z NAM SUGGESTED SHOWED THAT MODEL COMING IN
DRIER THAN ITS PRIOR RUN AND LOOKING MORE LIKE THE DRY 00Z GFS.
THUS MADE A FEW LAST MINUTE CHANGES...MAINLY LOWERED AFTN POPS
QUICKER.
AIRMASS PRESSING DOWN BEHIND WAVE ON SUNDAY IS PRETTY COLD AND
WITH SFC RIDGE AXIS BUILDING DOWN THE MO RIVER VALLEY...POTENTIAL
FOR VERY COLD TEMPERATURES STILL EXISTS. MAIN CAVEAT WOULD BE IF
MID CLOUDS SPREAD BACK OVER AREA PER 00Z GFS...FOR THAT REASON
KEPT ERN ZONES THE COLDEST BUT BLENDED WRN COUNTIES INTO WARMER
NEIGHBORS NUMBERS WHICH RAISED THEM A FEW DEGREES.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 300 AM CST SAT FEB 8 2014
FAST FLOW ALSO LENDS FOR POTENTIAL MODEL SOLUTION FLIP-FLOPPING
WITH ECMWF A GOOD EXAMPLE. YDA THE 00Z RUN SUGGESTED A MIDWEEK
WAVE WOULD PUSH A MODEST COLD FRONT INTO FORECAST AREA BY
THURSDAY...BUT MOST RECENT 00Z RUN HAD A TRAILING WAVE SPREADING
DECENT WARM ADVECTION ACROSS FA INTO THURSDAY MORNING AND THEN
COOL ADVECTION WEAK ENOUGH TO ALLOW GOOD MIXING AND VERY MILD
TEMPS BY AFTN. MEANWHILE...GFS WAS STRONGER WITH COLD ADVECTION
INTO THURSDAY MORNING AND MUCH COLDER WITH FORECAST HIGHS.
THUS...DECIDED TO LEAVE IN A BLEND OF PRIOR RUN/PREVIOUS FORECAST
FOR MAX TEMPERATURES AND HANDLE ANY ADJUSTMENTS WHEN MODELS BECOME
MORE IN-LINE AND CONSISTENT. DID LOWER LOWS ACROSS THE EAST TUE AM
SINCE THAT AREA WILL BE LAST TO FEEL OVERNIGHT IMPACTS OF RETURN
FLOW/WARM ADVECTION PER GENERAL CONSENSUS AMONG MODELS. AS FOR
PRECIP...ADDED SLIGHT CHC SNOW POPS TO FRIDAY OTHERWISE EXTENDED
WAS DRY. YDAS 12Z ECMWF WAS FAIRLY STRONG WITH SHORT-WAVE ENERGY
ACTING ON A STALLING COLD FRONT GENERATING A LARGE SWATH OF
MODESTLY HIGH QPF ACROSS ERN NEBR/WRN IA. ALTHOUGH 00Z RUN BACKED
MARKEDLY OFF THAT SOLUTION...IT DID KEEP A WEAK WAVE MOVG TOWARD
AREA BY 00Z SAT WITH A SCATTERING OF LIGHT QPF OVER PLAINS WITH
SOME HINT OF SAME PER 00Z GFS.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 609 AM CST SAT FEB 8 2014
BACK EDGE OF LOW CLOUDS WAS APPROACHING KOFK AT 12Z AND SHOULD
CLEAR BY 14Z WITH VFR CONDITIONS EXPECTED TO CONTINUE THROUGH
ABOUT 22Z. NOT AS CLEAR CUT FOR KOMA AND KLNK WITH MVFR CIGS
LIKELY TO HOLD UNTIL NEAR 18Z WITH A SHORT BREAK IN THE CLOUDS
BEFORE NEXT SHORT WAVE TROUGH AND COLD FRONT MOVE INTO THE AREA
WITH ADDITIONAL MVFR CIGS AND VSBY IN PERIODS OF SNOW THROUGH
06Z. VFR CONDITIONS EXPECTED TO DEVELOP 06Z-12Z AS HIGH BUILDS
INTO THE AREA.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...CHERMOK
LONG TERM...CHERMOK
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
957 AM EST SAT FEB 8 2014
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL CROSS THE SOUTHEAST
STATES TODAY... AS SURFACE HIGH PRESSURE OVER THE AREA WEAKENS. A
WEAK LOW PRESSURE TROUGH WILL HOLD OVER THE CAROLINAS TONIGHT
THROUGH SUNDAY NIGHT. A LOW PRESSURE SYSTEM WILL APPROACH FROM THE
WEST EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 930 AM SATURDAY...
TODAY:
SHORTWAVE ENERGY OVER THE SOUTHERN APPALACHIANS/SAVANNA RIVER
VALLEY WILL QUICKLY MOVE ENE AND OFF THE CAROLINA COAST BY MIDDAY.
SATELLITE AND OBSERVATION TRENDS SUPPORT WHAT THE HRRR AND THE WRF-
ARW SHOWED YESTERDAY EVENING...WITH THE PRECIP HUGGING THE COASTAL
SECTIONS OF THE CAROLINAS AND GEORGIA...OWING TO THE CONSIDERABLE
LOW-LEVEL FORCING FROM A COMBINATION OF STRONG LOW-MOISTURE FLUX
CONVERGENCE AND FRONTOGENESIS ASSOCIATED WITH THE OFFSHORE LOW
PRESSURE SYSTEM AND BAROCLINIC FRONTAL ZONE. WITH PRECIP CONFINED TO
THE COASTAL SECTIONS...THERE WILL BE P-TYPE ISSUES...WITH ALL RAIN
WITH PRECIP AMOUNTS AROUND A TENTH OF AN INCH OVER SAMPSON...WAYNE
COUNTIES.
BY 18Z...LOW-LEVEL VEERING AROUND TO WESTERLY WILL ADVECT DRIER AIR
INTO THE AREA...ENDING PRECIP CHANCES AS FORCING SHIFTS OFFSHORE
WITH PARTIAL CLEARING SPREADING EASTWARD. HIGHS TODAY IN THE MID 40
TO LOWER 50S...WARMEST SW. -CBL
FOR TONIGHT THROUGH SUNDAY NIGHT: ANOTHER WEAK SHORTWAVE TROUGH (NOW
WELL BACK OVER THE ROCKIES) CROSSES THE AREA LATE TONIGHT INTO
SUNDAY MORNING... ACCOMPANIED BY ANOTHER SURGE IN UPPER DIVERGENCE.
WHILE THE BULK OF THE MOISTURE WITH THIS APPEARS TO ZIP BY QUICKLY
TO OUR NORTH... THERE LOOKS TO BE JUST ENOUGH LOW LEVEL MOISTURE AND
WEAK MASS CONVERGENCE ALONG A DEVELOPING SURFACE TROUGH OVER THE
FOOTHILLS/WRN PIEDMONT FOR A SMALL CHANCE OF SPRINKLES ACROSS THE
EXTREME NW AND NRN CWA... MAINLY SUNDAY MORNING. REGARDLESS... THE
HIGH-LEVEL LIFT SHOULD ENSURE AT LEAST PARTLY CLOUDY SKIES FOR MUCH
OF THE DAY... IF NOT OCCASIONALLY MOSTLY CLOUDY. DESPITE THE
CLOUDS... THE INCREASING SW FLOW AHEAD OF THIS TROUGH ON SUNDAY IS
LIKELY TO DRAW IN SOME MILDER AIR WITH THICKNESSES SLIGHTLY ABOVE
NORMAL... RESULTING IN WHAT MAY BE THE WARMEST (RELATIVELY SPEAKING)
DAY OF THE NEXT SEVERAL DAYS. AFTER LOWS OF 29-34... EXPECT HIGHS OF
53-60. AS THE STILL-WEAK BUT STRENGTHENING SURFACE TROUGH DROPS
SOUTHEAST THROUGH NC... SETTLING WEST-TO-EAST ACROSS SRN NC... WHILE
MID LEVEL FLOW SPEEDS UP AHEAD OF YET ANOTHER WEAK WAVE APPROACHING
FROM THE WEST... WE SHOULD SEE AN INCREASE IN CLOUD COVER SUNDAY
NIGHT. THIS SHOULD KEEP LOWS UP IN THE 34-38 RANGE. -GIH
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...
COLD FRONT/TROUGH MOVING SOUTHEAST THROUGH THE AREA EARLY MONDAY
WILL SETTLE SOUTH ACROSS SC DURING THE DAY. LACKING MUCH UPPER
LEVEL SUPPORT...MODELS ARE IN FAIR AGREEMENT ON A MOSTLY DRY FRONTAL
PASSAGE AND DWINDLING ANAFRONTAL PRECIP EAST OF THE MOUNTAINS. WILL
MAINTAIN A SLIGHT CHANCE POP MONDAY AFTERNOON/EVENING AND ACROSS
SOUTHERN COUNTIES MONDAY NIGHT AS THE FRONT STALLS TO OUR SOUTH AND
MODELS INDICATE THE POTENTIAL FOR MULTIPLE WAVES OF LOW PRESSURE TO
TRACK ON THE BOUNDARY. CLEARING BEHIND THE FRONT SHOULD BE QUICKLY
FILLED BACK IN BY INCREASING SOUTHERN STREAM MOISTURE IN THE MID AND
UPPER LEVELS. COLD ADVECTION...WHILE NOT VERY STRONG
INITIALLY...WILL KEEP HIGHS FROM CLIMBING TO MUCH MORE THAN THE MID
AND UPPER 40S. STRONGER COLD ADVECTION MONDAY NIGHT WILL DROVE LOWS
BACK DOWN INTO THE UPPER 20S AND LOWER 30S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 AM SATURDAY...
THERE REMAINS QUITE A LOT OF UNCERTAINTY REGARDING THE DETAILS OF A
WINTRY MIX OF PRECIP FOR THE MIDDLE OF NEXT WEEK...
BROAD CYCLONIC FLOW ALOFT WILL REMAIN IN PLACE OVER THE EASTERN
US... WITH A SURFACE HIGH FORECAST TO BUILD FROM THE MID WEST TOWARD
THE MID-ATLANTIC AND NEW ENGLAND STATES. MEANWHILE...A SOUTHERN
STREAM...AND CURRENTLY POORLY SAMPLED SHORTWAVE OVER THE PACIFIC
WILL TRAVERSE THE SOUTHERN US AS VARIOUS PIECES OF NORTHERN STREAM
STREAM ENERGY MOVE ACROSS THE MIDWEST STATES. THE MAIN FORECAST
PROBLEM WILL BE TO WHAT...IF ANY...DEGREE THESE WAVES PHASE...AND
THE TRACK OF AN ASSOCIATED SURFACE WAVE ALONG THE STALLED BOUNDARY
TO OUR SOUTH. WPC GUIDANCE CONTINUES TO LEAN AWAY FROM THE
DETERMINISTIC GFS AND ECMWF... AND TOWARD MORE THE SUPPRESSED MILLER
A TYPE SURFACE LOW TRACKS OF THE GEFS AND EC ENSEMBLE MEANS.
CONSIDERING THIS...IT SEEMS THE BEST WAY TO APPROACH THE FORECAST
UNCERTAINTY IS TO FOCUS ON HOW THE SYSTEMS MAY EVOLVE: 1) WITH THE
FRONT TO OUR SOUTH AND THE FLOW INITIALLY LESS AMPLIFIED...MOISTURE
AND POP SHOULD BE GREATEST ACROSS SOUTHERN AREAS TUESDAY/TUESDAY
NIGHT. THERMAL PROFILES WOULD SUPPORT A RAIN/SNOW MIX ACROSS THE
SOUTH AND A BETTER CHANCE OF SNOW TO THE NORTH. 2) AS THE
SOUTHERN STREAM SHORTWAVE BECOMES A PLAYER WEDNESDAY/THURSDAY...AND
IF PHASING/AMPLIFICATION WITH THE NORTHERN STREAM WAVE OCCURS...THEN
A COASTAL LOW SHOULD DEVELOP AND PTYPE WOULD TRANSITION TO A MORE
CLIMATOLOGICALLY FAVORED DISTRIBUTION...WITH A WINTRY MIX MORE
LIKELY OVER THE NORTHWEST PIEDMONT AND RAIN OVER THE COASTAL PLAIN.
THE EXTENT OF WINTRY PRECIP WILL ALSO BE STRONGLY INFLUENCED BY HOW
LONG SURFACE HIGH OVER THE NORTHEAST US HOLDS IN PLACE.
DUE TO THE UNCERTAINTY AND TO KEEP CONSISTENCY WITH THE PREVIOUS
FORECAST...WILL ONLY MAKE MINOR ADJUSTMENTS TO THE FORECAST...MAINLY
TO INTRODUCE A SMALL CHANCE OF RAIN OR SNOW TUESDAY MORNING AND TO
EXPAND THE RAIN/SNOW AREA A BIT. HIGHS WILL BE WELL BELOW NORMAL
THROUGH MOST OF THE WEEK...LIKELY REMAINING BELOW 40 TUESDAY AND
WEDNESDAY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 625 AM SATURDAY...
NOT A HIGH-CONFIDENCE FORECAST THIS MORNING... AS THERE ARE
DIFFERING SIGNALS AS TO THE EFFECTS OF AN UPPER LEVEL DISTURBANCE
THAT CROSSES THE REGION TODAY AND A LOW PRESSURE AREA THAT FORMS OFF
THE COAST. WE DO HAVE HIGH CONFIDENCE THAT VFR CONDITIONS WILL HOLD
THROUGH DAYBREAK ACROSS CENTRAL NC. CIGS ARE EXPECTED TO LOWER THIS
MORNING AS THE DISTURBANCE APPROACHES... AND WHILE THE MODEL
GUIDANCE AND OBSERVED TRENDS SUPPORT CIGS REMAINING VFR WITH DRIER
AIR IN THE LOWEST 4000 FT AGL... THERE REMAINS A CHANCE THAT CIGS
COULD DROP TO MVFR... ALONG WITH POSSIBLE 6SM VSBYS IN LIGHT RAIN
POSSIBLY MIXED WITH A LITTLE LIGHT SNOW AT FAY/INT/GSO... BETWEEN
THE HOURS OF 13Z AND 20Z. AFTER 20Z... HIGHER CONFIDENCE THAT VFR
CIGS/VSBYS WILL RETURN AS THE DISTURBANCE AND SURFACE LOW BOTH EXIT
THE AREA QUICKLY TO THE NORTHEAST. SURFACE WINDS WILL REMAIN LIGHT
AND VARIABLE... BUT MAINLY FROM THE NORTHEAST OR ENE... THROUGH
TONIGHT.
LOOKING BEYOND 12Z SUNDAY MORNING... FORECAST CONFIDENCE REMAINS
BELOW AVERAGE. A WEAK SURFACE TROUGH HOLDS OVER THE AREA THROUGH
SUNDAY NIGHT... WITH ANOTHER WEAK WAVE CROSSING THE AREA. MVFR CIGS
ARE POSSIBLE SUNDAY MORNING MAINLY AT INT/GSO... ALTHOUGH THERE ARE
INDICATIONS OF POSSIBLE LOW CLOUDS/FOG EARLY SUNDAY MORNING
AREAWIDE. VFR CONDITIONS ARE LIKELY TO DOMINATE FROM SUNDAY
AFTERNOON INTO WEDNESDAY... HOWEVER ANOTHER MID LEVEL WAVE AND
SURFACE LOW/FRONT WILL BRING A RISK OF MVFR CIGS MONDAY THROUGH
TUESDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...CBL/HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
946 AM EST SAT FEB 8 2014
.SYNOPSIS...
LOW PRESSURE WELL OFF THE CAROLINA COAST WILL MOVE TO THE
NORTHEAST...REMAINING WELL OFFSHORE. A BRIEF WARM-UP IS EXPECTED
SUNDAY AHEAD OF A COLD FRONT THAT WILL CROSS THE CAROLINAS EARLY
MONDAY. HIGH PRESSURE WILL RIDGE ACROSS THE AREA MONDAY AND
TUESDAY...AND GIVE WAY TO DEVELOPING LOW PRESSURE FROM THE GULF OF
MEXICO DURING THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...SURFACE LOW PRESSURE ALONG A STALLED COLD
FRONT IS LOCATED ABOUT 220 MILES SOUTH OF CAPE FEAR. THIS LOW IS
MOVING RAPIDLY NORTHEAST AND SHOULD REMAIN WELL OFFSHORE TODAY AND
TONIGHT. ISENTROPIC LIFT OF GULF MOISTURE ACROSS THE FRONTAL
INVERSION IS PRODUCING LIGHT TO MODERATE RAINFALL ALL ALONG THE
SOUTHEASTERN U.S. FROM THE FLORIDA PANHANDLE AND GEORGIA ACROSS THE
EASTERN CAROLINAS. IT IS A COLD RAIN WITH TEMPERATURES IN THE UPPER
30S TO LOWER 40S ACROSS THE AREA.
THE 06Z NAM APPEARS TO HAVE THE BEST HANDLE ON THE THERMAL STRUCTURE
AND WINDS WITHIN THE LOWER ATMOSPHERE...ALTHOUGH IT HAD SOME ISSUES
WITH MOISTURE DISTRIBUTION ALOFT WHEN COMPARED TO THE 12Z SOUNDINGS
AT CHS AND MHX. THE LAST SEVERAL RUC AND HRRR RUNS ARE SHOWING
MODERATE TO MAJOR INITIALIZATION ISSUES THAT ARE MAKING THEM
UNUSABLE FOR THIS FORECAST UPDATE. EAST OF I-95 RAIN SHOULD CONTINUE
THROUGH EARLY AFTERNOON WITH A TAPERING OFF TREND EXPECTED BETWEEN
1-3 PM FROM WEST TO EAST. WEST OF I-95 MID-LEVEL MOISTURE IS MUCH
MORE SPORADIC WITH MAINLY LIGHT SPITS OF RAIN OBSERVED SO FAR. THIS
SHOWS UP IN MY QPF GRIDS WHICH RANGE FROM ONLY A COUPLE HUNDREDTHS
OF AN INCH IN DARLINGTON AND BENNETTSVILLE TO JUST OVER ONE-THIRD OF
AN INCH ALONG THE COAST.
I HAVE ADJUSTED FORECAST HIGHS DOWNWARD BY A COUPLE DEGREES ACROSS
COASTAL SE NORTH CAROLINA WHERE RAIN WILL PERSIST LONGEST...WITH
LESSER ADJUSTMENTS MADE ACROSS SOUTH CAROLINA. FORECAST HIGHS RANGE
FROM THE MID 40S IN WILMINGTON...TO THE UPPER 40S ACROSS THE GRAND
STRAND...CONWAY...WHITEVILLE...AND LUMBERTON. ACROSS THE PEE DEE AND
SANTEE RIVER REGION ASSUMING RAIN SHUTS OFF ON SCHEDULE HIGHS COULD
REACH 50-52 BRIEFLY DURING THE LATE AFTERNOON HOURS. BUT AS
LONG AS RAIN CONTINUES TEMPERATURES WILL REMAIN STUCK IN THE UPPER
30S TO LOWER 40S WITH EVAPORATIONAL COOLING BALANCING ANY WEAK
INSOLATION THROUGH THE CLOUDS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...A RAIN-FREE AND SEASONABLE SUNDAY EXPECTED DUE
TO NEARLY ZONAL MID LEVEL FLOW AND A POORLY DEFINED SURFACE PRESSURE
PATTERN. TEMPS GET LOWERED A NOTCH ON MONDAY AS A COLD FRONT PUSHES
THROUGH ALTHOUGH THE TIMING OF THE BOUNDARY IS VERY POORLY AGREED
UPON BETWEEN VARIOUS MODEL GUIDANCE. THE SEEMING OUTLYING WRF EVEN
SHOWS A SLOW ENOUGH FROPA FOR A MILD AFTERNOON. FROPA ITSELF WILL BE
TOO MOISTURE STARVED TO LEAD TO ANY MEANINGFUL RAIN CHANCES. SLIGHT
CHANCE POPS CROP UP TOWARDS THE END OF THE PERIOD AS WARM AIR BEGINS
TO OVERRUN THE POST-FRONTAL SURFACE HIGH.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...CHANCES FOR RAIN INCREASE AS TUESDAY WEARS ON
DUE TO WEAK LOW PRESSURE DEVELOPING ON FRONTAL BOUNDARY WELL OFF THE
COAST. TOUGH TO SAY WHETHER THERE IS A SHORT BREAK TUESDAY NIGHT
BEFORE THE NEXT SYSTEM TAKES SHAPE IN SIMILAR LOCATION. THIS LOOKING
RATHER IMPORTANT AS TEMP PROFILES SEEM SUPPORTIVE OF AT LEAST SOME
WINTRY PTYPE. THE GFS HAS BACKED OFF IN ITS DEPICTION OF THIS SYSTEM
BENEFITING FROM GOMEX MOISTURE WHILE THE ECMWF STILL LOOKS FAIRLY
WET. ALSO FAIRLY NEW IS THE MUCH SLOWER TIMING IN THE GFS SHOWING
THE BEST CHANCE FOR RAIN NOT UNTIL THURSDAY. WILL STICK MORE IN LINE
WITH PREV FCST DUE TO SUPPORT FROM ECMWF BUT SHOW VERY LOW RAIN
CHANCES ON THURSDAY. BEHIND THIS SYSTEM A MODERATING TREND SHOULD
GET UNDERWAY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...CYCLOGENESIS IS OCCURRING OFF THE COAST AS WEAK LOW
PRESSURE DEEPENS...INFLUENCED BY THE DIVERGENT QUADRANT OF THE JET
STREAM. MODELS ARE NOT IN AGREEMENT (THREW THE HRRR OUT
ALTOGETHER). THE NAM SEEMED TO INITIALIZE THE BEST...WITH MOST OF
THE PRECIP EAST OF THE I-95 CORRIDOR. LOOK FOR LOWERING CEILINGS
THIS MORNING AS THE RAIN BECOMES MORE WIDESPREAD. LOOKING FOR MVFR
AFTER 14Z...HOWEVER IFR IS NOT OUT OF THE QUESTION. VISIBILITIES
COULD BRIEFLY TOUCH TWO MILES...BUT SHOULD BE FOUR OR HIGHER THE
MAJORITY OF THE TIME. NORTHEAST FLOW WILL CONTINUE THROUGH THE
AFTERNOON HOURS. CONDITIONS WILL IMPROVE TO VFR TOWARD EVENING AS
LOW PRESSURE PULLS AWAY.
EXTENDED OUTLOOK...VFR EXPECTED THROUGH MONDAY AFTERNOON.
DETERIORATING CONDITIONS MONDAY NIGHT WITH MODERATE CONFIDENCE FOR
IFR CONDITIONS IN PRECIP TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...LOW PRESSURE IS ANALYZED ABOUT 220 MILES
SOUTH OF CAPE FEAR AND MOVING NORTHEASTWARD ALONG A STALLED COLD
FRONT THAT BISECTS FLORIDA. THE PRESSURE GRADIENT BETWEEN THIS LOW
AND HIGH PRESSURE NOSING DOWN FROM THE NORTH IS PRODUCING NE WINDS
15-25 KT ACROSS THE CAROLINA COASTAL WATERS CURRENTLY. THE 06Z NAM
APPEARS TO HAVE THE BEST HANDLE ON THE CURRENTLY SITUATION AND IS
OUR MODEL OF CHOICE.
THE STRONGEST WINDS ARE EXPECTED TO OCCUR BETWEEN NOW AND 1
PM...WITH WINDS GRADUALLY BACKING MORE NORTHERLY AND DIMINISHING IN
SPEED SLIGHTLY DURING THE MID AND LATE AFTERNOON. RADAR SHOWS A
NEARLY SOLID SHIELD OF RAIN EXTENDING BACK INTO NORTHERN FLORIDA
WHICH WILL TAKE ITS TIME CLEARING THE AREA TODAY. EXPECT
RAIN...OCCASIONALLY MODERATE IN INTENSITY...TO CONTINUE THROUGH THE
DAY. SEAS CURRENTLY RANGE FROM 6 FEET OUT AT THE FRYING PAN SHOALS
BUOY TO 4 FEET AT THE CAPE FEAR HARBOR BUOY SOUTH OF SOUTHPORT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...WIND BECOMES LIGHT ON SUNDAY AS PRESSURE
GRADIENT BECOMES QUITE WEAK ACROSS THE SOUTHEASTERN U.S. AN
APPROACHING COLD FRONT WILL LEAD TO A PRONOUNCED OFFSHORE FLOW
DIRECTION AS THE DAY WEARS ON WITH A POSSIBLE BACKING FROM NW TO SW.
LATE DAY/SUNDAY NIGHT ALSO SHOULD BRING A 5KT OR SO INC IN SPEEDS.
SEAS TO BUILD BUT ONLY ABOUT A FT AND AWAY FROM SHORE IN THE
COAST-PARALLEL FLOW. SHARP VEER TO N ON MONDAY AS COLD FRONT MOVES
THROUGH RATHER QUICKLY. ADD ANOTHER FT TO SEAS BUT STILL FALLING SHY
OF HEADLINES. HIGH BUILDS IN FROM THE NW ON MONDAY NIGHT CAUSING A
TURN TO THE NE.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...NE TO E WINDS ON TUESDAY TO STRENGTHEN AS HIGH
PRESSURE FINALLY BUILDS INTO NORTHEAST AND MID ATLANTIC. FLAT WAVE
OF LOW PRESSURE TO HOLD THE GRADIENT CLOSE TO THE COAST AND TIGHTEN
IT JUST ENOUGH TO MARGINAL SMALL CRAFT ADVISORY FOR WIND AND SEAS
FOR AT LEAST PART OF THE AREA. ANOTHER WAVE MAY TAKE A SIMILAR
TRACK ON WEDNESDAY LEADING TO FAIRLY UNCHANGED MARINE ENVIRONMENT
AND ADVISORY STILL SEEMS POSSIBLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 7 PM EST SATURDAY FOR
AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
635 AM EST SAT FEB 8 2014
.SYNOPSIS...
WEAK ATLANTIC LOW PRESSURE WILL QUICKLY MOVE TO THE NORTHEAST...
PASSING WELL EAST OF THE AREA TODAY. A BRIEF WARM-UP IS EXPECTED
SUNDAY AHEAD OF A COLD FRONT THAT WILL CROSS THE CAROLINAS EARLY
MONDAY. HIGH PRESSURE WILL RIDGE ACROSS THE AREA MONDAY AND
TUESDAY...AND GIVE WAY TO DEVELOPING LOW PRESSURE FROM THE GULF OF
MEXICO DURING THE MIDDLE PORTIONS OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM SATURDAY...RAIN WAS INCREASING IN COVERAGE NEAR DAYBREAK.
POPS WILL CONTINUE TO STEADILY INCREASE THROUGH ABOUT MIDDAY AND
THEN BEGIN TO TREND QUICKLY LOWER...FALLING BELOW THRESHOLD LASTLY
ACROSS THE CAPE FEAR REGION.
ATLANTIC LOW PRESSURE WAS DEVELOPING ABOUT 275 MILES S OF THE
MOUTH OF THE CAPE FEAR RIVER. THE LOW WILL MOVE NE...PASSING WELL
OFF THE COAST TODAY WHILE REMAINING WEAK. THE LOW-LEVEL FLOW ACROSS
THE EASTERN CAROLINAS WAS NE TO N THROUGH 3-4 KFT. ABOVE THAT
LEVEL...THE FLOW WAS SW OR WSW AND STRONG. A MID-LEVEL SHORTWAVE
TROUGH EMBEDDED IN THE FLOW WILL MOVE ACROSS THE FORECAST AREA THIS
AFTERNOON. THE MAIN CATALYST FOR RAIN TODAY WILL BE THE MOIST SW
FLOW ATOP THE RESIDUAL CHILLY AIRMASS IN PLACE. THE LOW-LEVEL FLOW
WILL BACK TO THE N TONIGHT...REINFORCING THE CHILLY AIR AT THE
SURFACE.
THE RAIN IS EXPECTED TO BREAK OUT THIS MORNING...BUT QUICKLY COME TO
AN END THIS AFTERNOON AS A SHORTWAVE MOVES THROUGH AND HELPS TO
USHER IN MUCH DRIER AIR ALOFT. AT THIS TIME...THE RAIN EVENT LOOKS
MOST SIGNIFICANT ALONG AND NEAR THE COAST WHERE THE DEPTH OF
MOISTURE PERSISTS THE LONGEST. WE ARE FORECASTING AROUND A THIRD OF
AN INCH ALONG THE COAST. AS YOU MOVE INLAND...THE MOISTURE RETURN
BECOMES PROGRESSIVELY ANEMIC AND WE ARE ONLY EXPECTING AROUND A
TENTH OF AN INCH OR LESS OF RAIN FROM LBT TO FLO WESTWARD. THE RAIN
WILL PERSIST LONGEST AT THE COAST.
THICK CLOUDS TODAY WILL ERODE LATE DAY AND THIS EVE AS HIGH PRESSURE
BEGINS TO NOSE DOWN THE COAST IN THE WAKE OF DEPARTING COASTAL LOW
PRESSURE. ALTHOUGH THE MID-LEVELS WILL BE DRY...RESIDUAL MOISTURE AT
THE SURFACE WILL REMAIN. AS THE COLUMN COOLS...A PRONOUNCED SURFACE
INVERSION IS EXPECTED TO DEVELOP AND THIS SHOULD RESULT IN
WIDESPREAD LOW STRATUS AND FOG. THE WORST OF THE FOG IS EXPECTED
OVERNIGHT AND SUN MORNING. VISIBILITIES WILL LIKELY BECOME
SIGNIFICANTLY RESTRICTED DUE TO FOG AND IN FACT...FOG MAY BE DENSE
IN MANY PLACES.
THE THICK CLOUDS AND CHILLY RAINFALL WILL SERVE TO KEEP TEMPERATURES
WELL BELOW NORMAL TODAY...UPPER 40S TO AROUND 50 DEGREES. LOWS
TONIGHT WILL ALSO BE CHILLY...MAINLY MID 30S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...A RAIN-FREE AND SEASONABLE SUNDAY EXPECTED DUE
TO NEARLY ZONAL MID LEVEL FLOW AND A POORLY DEFINED SURFACE PRESSURE
PATTERN. TEMPS GET LOWERED A NOTCH ON MONDAY AS A COLD FRONT PUSHES
THROUGH ALTHOUGH THE TIMING OF THE BOUNDARY IS VERY POORLY AGREED
UPON BETWEEN VARIOUS MODEL GUIDANCE. THE SEEMING OUTLYING WRF EVEN
SHOWS A SLOW ENOUGH FROPA FOR A MILD AFTERNOON. FROPA ITSELF WILL BE
TOO MOISTURE STARVED TO LEAD TO ANY MEANINGFUL RAIN CHANCES. SLIGHT
CHANCE POPS CROP UP TOWARDS THE END OF THE PERIOD AS WARM AIR BEGINS
TO OVERRUN THE POST-FRONTAL SURFACE HIGH.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...CHANCES FOR RAIN INCREASE AS TUESDAY WEARS ON
DUE TO WEAK LOW PRESSURE DEVELOPING ON FRONTAL BOUNDARY WELL OFF THE
COAST. TOUGH TO SAY WHETHER THERE IS A SHORT BREAK TUESDAY NIGHT
BEFORE THE NEXT SYSTEM TAKES SHAPE IN SIMILAR LOCATION. THIS LOOKING
RATHER IMPORTANT AS TEMP PROFILES SEEM SUPPORTIVE OF AT LEAST SOME
WINTRY PTYPE. THE GFS HAS BACKED OFF IN ITS DEPICTION OF THIS SYSTEM
BENEFITING FROM GOMEX MOISTURE WHILE THE ECMWF STILL LOOKS FAIRLY
WET. ALSO FAIRLY NEW IS THE MUCH SLOWER TIMING IN THE GFS SHOWING
THE BEST CHANCE FOR RAIN NOT UNTIL THURSDAY. WILL STICK MORE IN LINE
WITH PREV FCST DUE TO SUPPORT FROM ECMWF BUT SHOW VERY LOW RAIN
CHANCES ON THURSDAY. BEHIND THIS SYSTEM A MODERATING TREND SHOULD
GET UNDERWAY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...CYCLOGENESIS IS OCCURRING OFF THE COAST AS WEAK LOW
PRESSURE DEEPENS...INFLUENCED BY THE DIVERGENT QUADRANT OF THE JET
STREAM. MODELS ARE NOT IN AGREEMENT (THREW THE HRRR OUT
ALTOGETHER). THE NAM SEEMED TO INITIALIZE THE BEST...WITH MOST OF
THE PRECIP EAST OF THE I-95 CORRIDOR. LOOK FOR LOWERING CEILINGS
THIS MORNING AS THE RAIN BECOMES MORE WIDESPREAD. LOOKING FOR MVFR
AFTER 14Z...HOWEVER IFR IS NOT OUT OF THE QUESTION. VISIBILITIES
COULD BRIEFLY TOUCH TWO MILES...BUT SHOULD BE FOUR OR HIGHER THE
MAJORITY OF THE TIME. NORTHEAST FLOW WILL CONTINUE THROUGH THE
AFTERNOON HOURS. CONDITIONS WILL IMPROVE TO VFR TOWARD EVENING AS
LOW PRESSURE PULLS AWAY.
EXTENDED OUTLOOK...VFR EXPECTED THROUGH MONDAY AFTERNOON.
DETERIORATING CONDITIONS MONDAY NIGHT WITH MODERATE CONFIDENCE FOR
IFR CONDITIONS IN PRECIP TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM SATURDAY...WEAK ATLANTIC LOW PRESSURE...MOVING NE...WILL
PASS WELL OFF THE CAROLINA COAST TODAY. THE GRADIENT ON THE BACKSIDE
OF THE LOW IS EXPECTED TO TIGHTEN JUST ENOUGH TO ALLOW FOR A PERIOD
OF MARGINAL SMALL CRAFT ADVISORY CONDITIONS. THE HIGHEST WINDS THIS
PERIOD ARE EXPECTED INTO THIS AFTERNOON...UP TO 20 TO 25 KT...
HIGHEST ACROSS THE OUTERMOST WATERS. NE WINDS THIS MORNING WILL
BACK TO N BY MIDDAY AND REMAIN FROM THE N TONIGHT. SEAS ARE EXPECTED
TO BUILD THROUGH THE MORNING...REACHING UP TO 4 TO 6 FT...AGAIN
HIGHEST ACROSS THE OUTERMOST WATERS. BOTH WINDS AND SEAS WILL
STEADILY SUBSIDE TONIGHT IN THE WAKE OF DEPARTING LOW PRESSURE AS
WEAK HIGH PRESSURE NOSES IN FROM THE N.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...WIND BECOMES LIGHT ON SUNDAY AS PRESSURE
GRADIENT BECOMES QUITE WEAK ACROSS THE SOUTHEASTERN U.S. AN
APPROACHING COLD FRONT WILL LEAD TO A PRONOUNCED OFFSHORE FLOW
DIRECTION AS THE DAY WEARS ON WITH A POSSIBLE BACKING FROM NW TO SW.
LATE DAY/SUNDAY NIGHT ALSO SHOULD BRING A 5KT OR SO INC IN SPEEDS.
SEAS TO BUILD BUT ONLY ABOUT A FT AND AWAY FROM SHORE IN THE
COAST-PARALLEL FLOW. SHARP VEER TO N ON MONDAY AS COLD FRONT MOVES
THROUGH RATHER QUICKLY. ADD ANOTHER FT TO SEAS BUT STILL FALLING SHY
OF HEADLINES. HIGH BUILDS IN FROM THE NW ON MONDAY NIGHT CAUSING A
TURN TO THE NE.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...NE TO E WINDS ON TUESDAY TO STRENGTHEN AS HIGH
PRESSURE FINALLY BUILDS INTO NORTHEAST AND MID ATLANTIC. FLAT WAVE
OF LOW PRESSURE TO HOLD THE GRADIENT CLOSE TO THE COAST AND TIGHTEN
IT JUST ENOUGH TO MARGINAL SMALL CRAFT ADVISORY FOR WIND AND SEAS
FOR AT LEAST PART OF THE AREA. ANOTHER WAVE MAY TAKE A SIMILAR
TRACK ON WEDNESDAY LEADING TO FAIRLY UNCHANGED MARINE ENVIRONMENT
AND ADVISORY STILL SEEMS POSSIBLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 7 PM EST SATURDAY FOR
AMZ250-252-254-256.
&&
$$
NEAR TERM...RJD
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
555 AM EST SAT FEB 8 2014
.SYNOPSIS...
LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST COAST TODAY AND
INTENSIFY AS IT ACCELERATES TO THE NORTHEAST AND AWAY FROM THE AREA
THROUGH TONIGHT. A BRIEF WARM-UP IS EXPECTED SUNDAY AHEAD OF A COLD
FRONT THAT WILL CROSS THE CAROLINAS EARLY MONDAY. HIGH PRESSURE WILL
RIDGE ACROSS THE AREA MONDAY AND TUESDAY...AND GIVE WAY TO
DEVELOPING LOW PRESSURE FROM THE GULF OF MEXICO DURING THE MIDDLE
PORTIONS OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...ATLANTIC LOW PRESSURE WAS DEVELOPING ABOUT 275
MILES S OF THE MOUTH OF THE CAPE FEAR RIVER. THE LOW WILL MOVE
NE...PASSING WELL OFF THE COAST TODAY WHILE REMAINING WEAK. THE
LOW-LEVEL FLOW ACROSS THE EASTERN CAROLINAS WAS EASTERLY THROUGH 3-4
KFT. ABOVE THAT LEVEL...THE FLOW WAS SW OR WSW AND STRONG. A
MID-LEVEL SHORTWAVE TROUGH EMBEDDED IN THE FLOW WILL MOVE ACROSS
THE FORECAST AREA THIS AFTERNOON. THE MAIN CATALYST FOR RAIN TODAY
WILL BE THE MOIST SW FLOW ATOP THE RESIDUAL CHILLY AIRMASS IN PLACE.
THE LOW-LEVEL FLOW WILL BACK TO THE N TONIGHT...REINFORCING THE
CHILLY AIR AT THE SURFACE.
THE RAIN IS EXPECTED TO BREAK OUT THIS MORNING...BUT QUICKLY COME TO
AN END THIS AFTERNOON AS A SHORTWAVE MOVES THROUGH AND HELPS TO
USHER IN MUCH DRIER AIR ALOFT. AT THIS TIME...THE RAIN EVENT LOOKS
MOST SIGNIFICANT ALONG AND NEAR THE COAST WHERE THE DEPTH OF
MOISTURE PERSISTS THE LONGEST. WE ARE FORECASTING UP TO A THIRD OF
AN INCH ALONG THE COAST. AS YOU MOVE INLAND...THE MOISTURE RETURN
BECOMES PROGRESSIVELY ANEMIC AND WE ARE ONLY EXPECTING AROUND A
TENTH OF AN INCH OR LESS OF RAIN FROM LBT TO FLO WESTWARD. THE RAIN
WILL PERSIST LONGEST AT THE COAST.
THICK CLOUDS TODAY WILL ERODE LATE DAY AND THIS EVE AS HIGH PRESSURE
BEGINS TO NOSE DOWN THE COAST IN THE WAKE OF DEPARTING COASTAL LOW
PRESSURE. ALTHOUGH THE MID-LEVELS WILL BE DRY...RESIDUAL MOISTURE AT
THE SURFACE WILL REMAIN. AS THE COLUMN COOLS...A PRONOUNCED SURFACE
INVERSION IS EXPECTED TO DEVELOP AND THIS WILL RESULT IN WIDESPREAD
LOW STRATUS AND FOG. THE WORST OF THE FOG IS EXPECTED OVERNIGHT AND
SUN MORNING. VISIBILITIES WILL LIKELY BECOME SIGNIFICANTLY
RESTRICTED DUE TO FOG AND IN FACT...FOG MAY BE DENSE IN MANY PLACES.
THE THICK CLOUDS AND CHILLY RAINFALL WILL SERVE TO KEEP TEMPERATURES
WELL BELOW NORMAL TODAY...UPPER 40S TO AROUND 50 DEGREES. LOWS
TONIGHT WILL ALSO BE CHILLY...MAINLY MID 30S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...A RAIN-FREE AND SEASONABLE SUNDAY EXPECTED DUE
TO NEARLY ZONAL MID LEVEL FLOW AND A POORLY DEFINED SURFACE PRESSURE
PATTERN. TEMPS GET LOWERED A NOTCH ON MONDAY AS A COLD FRONT PUSHES
THROUGH ALTHOUGH THE TIMING OF THE BOUNDARY IS VERY POORLY AGREED
UPON BETWEEN VARIOUS MODEL GUIDANCE. THE SEEMING OUTLYING WRF EVEN
SHOWS A SLOW ENOUGH FROPA FOR A MILD AFTERNOON. FROPA ITSELF WILL BE
TOO MOISTURE STARVED TO LEAD TO ANY MEANINGFUL RAIN CHANCES. SLIGHT
CHANCE POPS CROP UP TOWARDS THE END OF THE PERIOD AS WARM AIR BEGINS
TO OVERRUN THE POST-FRONTAL SURFACE HIGH.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...CHANCES FOR RAIN INCREASE AS TUESDAY WEARS ON
DUE TO WEAK LOW PRESSURE DEVELOPING ON FRONTAL BOUNDARY WELL OFF THE
COAST. TOUGH TO SAY WHETHER THERE IS A SHORT BREAK TUESDAY NIGHT
BEFORE THE NEXT SYSTEM TAKES SHAPE IN SIMILAR LOCATION. THIS LOOKING
RATHER IMPORTANT AS TEMP PROFILES SEEM SUPPORTIVE OF AT LEAST SOME
WINTRY PTYPE. THE GFS HAS BACKED OFF IN ITS DEPICTION OF THIS SYSTEM
BENEFITING FROM GOMEX MOISTURE WHILE THE ECMWF STILL LOOKS FAIRLY
WET. ALSO FAIRLY NEW IS THE MUCH SLOWER TIMING IN THE GFS SHOWING
THE BEST CHANCE FOR RAIN NOT UNTIL THURSDAY. WILL STICK MORE IN LINE
WITH PREV FCST DUE TO SUPPORT FROM ECMWF BUT SHOW VERY LOW RAIN
CHANCES ON THURSDAY. BEHIND THIS SYSTEM A MODERATING TREND SHOULD
GET UNDERWAY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...CYCLOGENESIS IS OCCURRING OFF THE COAST AS WEAK LOW
PRESSURE DEEPENS...INFLUENCED BY THE DIVERGENT QUADRANT OF THE JET
STREAM. MODELS ARE NOT IN AGREEMENT (THREW THE HRRR OUT
ALTOGETHER). THE NAM SEEMED TO INITIALIZE THE BEST...WITH MOST OF
THE PRECIP EAST OF THE I-95 CORRIDOR. LOOK FOR LOWERING CEILINGS
THIS MORNING AS THE RAIN BECOMES MORE WIDESPREAD. LOOKING FOR MVFR
AFTER 14Z...HOWEVER IFR IS NOT OUT OF THE QUESTION. VISIBILITIES
COULD BRIEFLY TOUCH TWO MILES...BUT SHOULD BE FOUR OR HIGHER THE
MAJORITY OF THE TIME. NORTHEAST FLOW WILL CONTINUE THROUGH THE
AFTERNOON HOURS. CONDITIONS WILL IMPROVE TO VFR TOWARD EVENING AS LOW
PRESSURE PULLS AWAY.
EXTENDED OUTLOOK...VFR EXPECTED THROUGH MONDAY AFTERNOON.
DETERIORATING CONDITIONS MONDAY NIGHT WITH MODERATE CONFIDENCE FOR
IFR CONDITIONS IN PRECIP TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...WEAK LOW PRESSURE...MOVING NE...WILL PASS WELL
OFF THE CAROLINA COAST TODAY. THE GRADIENT ON THE BACKSIDE OF THE
LOW IS EXPECTED TO TIGHTEN JUST ENOUGH TO ALLOW FOR A PERIOD OF
MARGINAL SMALL CRAFT ADVISORY CONDITIONS. THE HIGHEST WINDS THIS
PERIOD ARE EXPECTED INTO THIS AFTERNOON...UP TO 20 TO 25 KT...
HIGHEST ACROSS THE OUTERMOST WATERS. ENE WINDS THIS MORNING WILL
BACK TO N BY MIDDAY AND REMAIN FROM THE N TONIGHT. SEAS ARE EXPECTED
TO BUILD THROUGH THE MORNING...REACHING UP TO 4 TO 6 FT...AGAIN
HIGHEST ACROSS THE OUTERMOST WATERS. BOTH WINDS AND SEAS WILL
STEADILY SUBSIDE TONIGHT IN THE WAKE OF DEPARTING LOW PRESSURE AS
WEAK HIGH PRESSURE NOSES IN FROM THE N.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...WIND BECOMES LIGHT ON SUNDAY AS PRESSURE
GRADIENT BECOMES QUITE WEAK ACROSS THE SOUTHEASTERN U.S. AN
APPROACHING COLD FRONT WILL LEAD TO A PRONOUNCED OFFSHORE FLOW
DIRECTION AS THE DAY WEARS ON WITH A POSSIBLE BACKING FROM NW TO SW.
LATE DAY/SUNDAY NIGHT ALSO SHOULD BRING A 5KT OR SO INC IN SPEEDS.
SEAS TO BUILD BUT ONLY ABOUT A FT AND AWAY FROM SHORE IN THE
COAST-PARALLEL FLOW. SHARP VEER TO N ON MONDAY AS COLD FRONT MOVES
THROUGH RATHER QUICKLY. ADD ANOTHER FT TO SEAS BUT STILL FALLING SHY
OF HEADLINES. HIGH BUILDS IN FROM THE NW ON MONDAY NIGHT CAUSING A
TURN TO THE NE.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...NE TO E WINDS ON TUESDAY TO STRENGTHEN AS HIGH
PRESSURE FINALLY BUILDS INTO NORTHEAST AND MID ATLANTIC. FLAT WAVE
OF LOW PRESSURE TO HOLD THE GRADIENT CLOSE TO THE COAST AND TIGHTEN
IT JUST ENOUGH TO MARGINAL SMALL CRAFT ADVISORY FOR WIND AND SEAS
FOR AT LEAST PART OF THE AREA. ANOTHER WAVE MAY TAKE A SIMILAR
TRACK ON WEDNESDAY LEADING TO FAIRLY UNCHANGED MARINE ENVIRONMENT
AND ADVISORY STILL SEEMS POSSIBLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 7 PM EST SATURDAY FOR
AMZ250-252-254-256.
&&
$$
NEAR TERM...RJD
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS BISMARCK ND
650 AM CST SAT FEB 8 2014
.UPDATE...
ISSUED AT 649 AM CST SAT FEB 8 2014
THE GOING FORECAST IS IN GOOD SHAPE AND ONLY MADE MINOR
ADJUSTMENTS TO CAPTURE THE LATEST TEMPERATURE TRENDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CST SAT FEB 8 2014
THE MAIN FOCUS FOR THE SHORT TERM IS ONCE AGAIN TEMPERATURES.
CLOUD COVER WILL PLAY A BIG ROLE WITH RESPECT TO TEMPERATURES
TODAY. THE LATEST GUIDANCE BUMPS UP HIGH TEMPERATURES 5 TO 10
DEGREES ABOVE THE PREVIOUS FORECAST. IF SKIES CLEAR OUT OVER
SOUTHERN NORTH DAKOTA THESE HIGHER TEMPERATURES COULD BE REALIZED.
HOWEVER...IF CLOUDY SKIES PREVAIL THE LOWER GUIDANCE/PREVIOUS
FORECAST WILL LIKELY VERIFY. THE MAIN COLD AIR ADVECTION SURGE
SHOULD HOLD OFF UNTIL LATE AFTERNOON. THEREFORE...I THINK THE
THICKEST CLOUD COVER WILL REMAIN NORTH MOST OF THE DAY. FOR THIS
REASON I WENT WITH THE SLIGHTLY WARMER HIGH TEMPERATURES ACROSS
THE SOUTH.
WITH THE COLD AIR ADVECTION SURGE THE 07 UTC RAP BRINGS IN SOME
LOWER CLOUDS AND LOW LEVEL MOISTURE DURING THE EVENING ACROSS THE
NORTH.SNOW FLURRIES AND EVEN A BRIEF SNOW SHOWER AREN`T OUT OF THE
QUESTION FOR THE NORTHERN COUNTIES SATURDAY EVENING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 350 AM CST SAT FEB 8 2014
THE START OF THE LONG TERM PERIOD WILL FEATURE NORTHWESTERLY FLOW
AT H5 WITH HIGH PRESSURE IN CONTROL AT THE SURFACE. TEMPERATURES
WILL BE COLD...AND COULD SEE THE EVENTUAL NEED FOR A WIND CHILL
ADVISORY. THIS IS ESPECIALLY TRUE SUNDAY NIGHT ACROSS THE NORTH
AND EAST WHERE WIND CHILLS VALUES COULD FALL INTO THE 20S AND 30S
BELOW ZERO.
WEST / NORTHWEST FLOW WILL DOMINATE THROUGH MOST OF NEXT WEEK. THIS
WILL ALLOW A SERIES OF FAST MOVING CLIPPERS TO MAKE THEIR WAY ACROSS
THE DAKOTAS...BRINGING PERIODIC CHANCES OF PRECIPITATION / SNOW. IT
APPEARS THERE IS GENERAL AGREEMENT BETWEEN THE GFS / ECMWF THAT A
SYSTEM TOWARDS THE MIDDLE OF THE WEEK COULD BE THE STRONGEST OF THE
CLIPPERS.
TEMPERATURES WILL SHOW QUITE A BIT OF VARIABILITY AS THE EXTENDED
PROGRESSES WITH PERIODS OF MODERATING TEMPERATURES...FOLLOWED BY
COOLER TEMPERATURES BEHIND THE WAVES. GENERALLY ACCEPTED THE
ALL-BLEND MODEL CONSENSUS REGARDING TEMPERATURES WHICH SHOULD HELP
MITIGATE SOME OF THE POTENTIAL TIMING DIFFICULTIES OF THE WAVES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 649 AM CST SAT FEB 8 2014
MVFR CEILINGS IN EASTERN MONTANA HAVE ONLY MADE SLOW PROGRESS INTO
WESTERN NORTH DAKOTA THIS MORNING. WILL CARRY A CEILING AROUND 3KFT
AT KISN AND KMOT STARTING THIS AFTERNOON...BUT KEEP THE OTHER
TERMINALS VFR. WIND SPEEDS SHOULD GENERALLY STAY 10 KTS OR LESS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CK
SHORT TERM...AJ
LONG TERM...CK
AVIATION...CK
AREA FORECAST DISCUSSION
NWS PORTLAND OR
745 AM PST SAT FEB 8 2014
.SYNOPSIS...THE THIRD SYSTEM IN A ONE-TWO-THREE PUNCH OF WINTRY
WEATHER WILL IMPACT NORTHWEST OREGON AND PORTIONS OF SOUTHWEST
WASHINGTON TODAY AND TONIGHT. LOW PRESSURE DEVELOPING OFF THE
SOUTHERN OREGON COAST WILL PUSH MORE MOISTURE INTO THE REGION...AND
TEMPERATURES ARE STILL GENERALLY BELOW FREEZING WITH THE EXCEPTIONS
BEING THE COAST AND HIGHER TERRAIN OF LANE COUNTY. SLIGHTLY WARMER
AIR ALOFT WILL LEAD TO A MAJOR ICE STORM FOR SOME INTERIOR VALLEYS
SALEM SOUTHWARD. ENOUGH COLD AIR REMAINS ENTRENCHED FOR MOST
PRECIPITATION TO FALL AS SNOW NORTH OF A SALEM TO TILLAMOOK LINE.
THIS SYSTEM WILL CLEAR OUT SUNDAY MORNING WITH JUST SOME LINGERING
RAIN AND SNOW SHOWERS FOR SUNDAY. GRADUALLY MILDER AIR MOVES IN BY
MONDAY...BUT NOT BEFORE MORE POTENTIAL ICING IN THE COLUMBIA GORGE.
ONSHORE FLOW AND A CONSOLIDATED PACIFIC JET WILL BRING A RETURN TO
MORE TYPICAL PERIODS OF VALLEY RAIN AND MOUNTAIN SNOW AS THE WEEK
PROGRESSES.
&&
.UPDATE...THE NAM BUFR AND RAP SOUNDINGS WOULD SUGGEST THE DOMINANT
PRECIPITATION TYPE IN THE CENTRAL VALLEY WILL LIKELY TURN BACK TO
FZRA AFTER SNOW THIS MORNING. 12Z SLE SOUNDING SHOWS THE WARM NOSE
CENTERED AROUND 900 MB WITH A TEMPERATURE OF 33F AT THIS LEVEL.
SOUNDINGS SUGGEST THIS ONLY GETS WARMER THROUGH THE DAY. IF YOU
FOLLOW RAP 925 MB TEMPERATURES WHICH HAVE A REASONABLE GRASP ON THE
LOCATION OF THE WARM NOSE...THIS PUSHES THROUGH THE CENTRAL VALLEY
AND EVEN NORTH THROUGH THE PORTLAND METRO AREA. THE BIG QUESTION IS
WHAT SURFACE TEMPERATURES DO. IF YOU BELIEVE MOS AND RAP...SURFACE
TEMPERATURES WILL WARM ABOVE FREEZING THROUGH THE CENTRAL VALLEY.
WITH A NORTH GRADIENT FEEDING THE LOWER LEVEL COLD AIR FEEL THIS IS
OVERDONE.
AM CONSIDERING CONVERTING THE CENTRAL VALLEY AND THE NORTH OREGON
FOOTHILLS TO AN ICE STORM WARNING. THERE IS A PRETTY HEAVY BAND OF
SNOWFALL THAT THE MODELS ARE IN REALLY GOOD AGREEMENT SETTING UP OVER
PORTLAND LATER THIS AFTERNOON AND EVENING. NAM BUFR SOUNDINGS KEEP
THE PORTLAND AREA ALL SNOW OR A MIX OF SLEET AND SNOW...BUT IT IS
CERTAINLY REASONABLE THAT THE SOUTH METRO AREA COULD GET IN ON THE
FREEZING RAIN . THIS COULD MAKE FOR A DISASTROUS SITUATION FOR THE
METRO AREA. THOSE OF YOU CONSIDERING TRAVEL TODAY SHOULD RECONSIDER
IF IT ALL POSSIBLE...AS THERE IS ALREADY SIGNIFICANT ICING AS FAR
NORTH AS ALBANY...AND IT IS LIKELY THIS AREA WILL CONTINUE TO SPREAD
NORTH...ESPECIALLY THIS AFTERNOON. WILL MAKE SOME DECISIONS SOON.
/KMD
.SHORT TERM...THE SHORT TERM DISCUSSION FOCUSES ON THE SYSTEM TO
IMPACT THE FORECAST AREA TODAY THROUGH SUNDAY...AS THIS WILL BE THE
BIG SHOW IN TOWN. A MAJOR RE-SHUFFLING OF WATCHES WARNINGS AND
ADVISORIES WAS DONE FOR THE MORNING PACKAGE...HENCE THE VERY LATE
DISCUSSION ONCE AGAIN. APOLOGIES FOR THAT.
TODAY THROUGH EARLY SUNDAY WILL FEATURE A HIGH-IMPACT...MULTI FACETED
WINTER STORM WHICH WILL AFFECT NORTHWEST OREGON AND PARTS OF
SOUTHWEST WASHINGTON WITH HEAVY SNOW...ICE...AND EVEN WIND NEAR THE
COLUMBIA GORGE. AREAS FROM THE PORTLAND/VANCOUVER METRO NORTHWARD
WILL SEE MAINLY SNOW...AND IT WILL BE HEAVY FOR A PERIOD THIS
AFTERNOON AND EVENING. AREAS FROM SALEM SOUTHWARD WILL SEE PRIMARILY
FREEZING RAIN WITH MAJOR ICE ACCUMULATIONS LIKELY IN SOME LOCATIONS.
SNOW LEVELS WILL RISE ACROSS THE SOUTHERN HALF OF OUR FORECAST AREA
FAIRLY RAPIDLY...SO THE LINN/LANE COUNTY CASCADES MAY SEE A QUICK
CHANGE TO RAIN AND VALLEY FREEZING RAIN AFTER A BRIEF PERIOD OF SNOW.
CASCADES NORTH OF SANTIAM PASS WILL SEE MORE IN THE WAY OF
SNOW...WITH UP TO A FOOT NEAR MOUNT HOOD.
THIS DISCUSSION WOULD GROW AS LARGE AS A NOVEL IF I WERE TO EXPLAIN
ALL THE METEOROLOGICAL REASONING BEHIND THESE DECISIONS. BELOW I WILL
FOCUS ON THE RATIONALE BEHIND WHAT WE CONSIDER THE MOST DANGEROUS
THREATS TO AFFECT THE AREA. THE MOST CONCERNING ISSUE WITH THIS
INCOMING SYSTEM WILL BE THE HEAVY ICE POTENTIAL FOR THE LOWLANDS...
PARTICULARLY THE CENTRAL AND SOUTH WILLAMETTE VALLEY.
INFRARED SATELLITE IMAGERY SHOWS A DEEPENING LOW PRESSURE SYSTEM NEAR
42N/132W...HEADING E-NE TOWARD THE OREGON COAST. THIS SYSTEM IS
STRONGER THAN THE LOW PRESSURE SYSTEMS THAT BROUGHT WIDESPREAD SNOW
TO THE REGION THURSDAY AND FRIDAY. AS A RESULT...WARM ADVECTION OUT
AHEAD OF THIS SYSTEM IS STRONGER THAN IT WAS WITH THE PREVIOUS TWO
SYSTEMS...PARTICULARLY BETWEEN 950-800 MB. MODEL SOUNDINGS SHOW GOOD
AGREEMENT THAT THIS WILL PUSH A WARM NOSE OF ABOVE FREEZING AIR WELL
NORTH INTO THE WILLAMETTE VALLEY...AND IN FACT THAT IS ALREADY
HAPPENING WITH -FZRA BEING REPORTED AT EUGENE. THIS SYSTEM HAS A
DECENT SUBTROPICAL TAP THAT EXTENDS SW TOWARD HAWAII...WHICH WILL
FEED PLENTY OF MOISTURE OVER THE LOW-LEVEL COLD AIR.
THE LOW-LEVEL COLD AIR IS BEING LOCKED IN BY INCREASING EASTERLY
PRESSURE GRADIENTS AND A DEEP COLD POOL EAST OF THE CASCADES. AS LOW
PRESSURE APPROACHES FROM THE SW...NORTHERLY PRESSURE GRADIENTS ARE
ALSO INCREASING UP THE WILLAMETTE VALLEY. THIS SHOULD KEEP THE ENTIRE
WILLAMETTE VALLEY BELOW FREEZING FOR A MAJORITY OF THE EVENT...WHILE
LOCALLY 0.35-0.75 INCH OF QPF FALL OVER MUCH OF NORTHWEST OREGON.
WITH SOME CONDITIONAL INSTABILITY...THERE WILL LIKELY BE SOME HEAVIER
BANDS WHICH MAY CONTRIBUTE TO QPF LOCALLY OVER ONE INCH. 00Z
ECMWF/UKMET...06Z NAM/GFS...ALL SHOW SOME FORM OF THIS OCCURRING.
SOUTH OF SALEM...WHERE PRECIPITATION WILL BE ALMOST ALL FREEZING
RAIN...NEARLY ALL OF THIS AMOUNT WILL FREEZE ON TREES... POWER
LINES...AND ROADS WHICH WILL MAKE FOR A VERY DANGEROUS SITUATION. AS
A RESULT...WE OPTED FOR AN ICE STORM WARNING FOR OUR SOUTHERN VALLEYS
TO HIGHLIGHT THIS THREAT. AREAS SALEM SOUTHWARD CAN EXPECT NUMEROUS
POWER OUTAGES TODAY AND TONIGHT...WHICH MAY TAKE SOME TIME TO RECOVER
FROM.
FARTHER NORTH...IN THE PORTLAND/VANCOUVER METRO...THE WARM NOSE WILL
HAVE A MORE DIFFICULT TIME WORKING ITS WAY TO THE COLUMN. THIS DUE TO
THE DEPTH OF THE COLD POOL EAST OF THE CASCADES...FILTERING COLD AIR
WESTWARD THROUGH THE GAPS AND PASSES. THE RELATIVELY LOWER TERRAIN
BETWEEN MOUNT ADAMS AND MOUNT HOOD WILL ALLOW THIS COLD AIR TO PUSH
FREELY WESTWARD INTO THE PDX/VUO METRO. IF THERE IS ANY QUESTION AS
TO THE MAGNITUDE OF THIS COLD AIR...IT IS ONLY 10 DEGREES AT
GOVERNMENT CAMP. BASED ON REPORTS NEAR THE CASCADE CREST IT APPEARS
THIS COLD POOL IS ABOUT 5000 FEET DEEP.
SINCE THE COLD AIR WILL BE STUBBORN IN THE PDX/VUO METRO...EXPECT
MOST PRECIPITATION TO FALL AS SNOW. BASED ON THE QPF EXPECT GENERAL
4-8 INCH TOTALS WHERE PCPN REMAINS SNOW...LIGHTER AMOUNTS NORTH OF
CLARK COUNTY. DEPENDING ON WHERE THE ABOVE-MENTIONED CSI BANDING SETS
UP...SOME SPOTS IN THE METRO AREA COULD SEE A FOOT OF NEW SNOW. THE
BEST CHANCE FOR THIS WILL BE WESTERN WASHINGTON AND YAMHILL COUNTY
WHERE EASTERLY FLOW OFTEN GETS A LITTLE OROGRAPHIC BOOST.
THERE ARE STILL SOME UNCERTAINTIES. IF THE EASTSIDE COLD POOL AND
ASSOCIATED COLD ADVECTION DOES NOT REMAIN AS DEEP THROUGH THE
CASCADES...THERE IS A CHANCE ENOUGH OF THE COLUMN MAY WARM ENOUGH TO
CHANGE PRECIPITATION TO SLEET IN THE PDX/VUO METRO THIS AFTERNOON AND
TONIGHT. THIS WOULD CONSIDERABLY CUT DOWN THE SNOW ACCUMULATION
POTENTIAL. THE BEST CHANCE FOR THIS TO HAPPEN IN THE NORTH WILLAMETTE
VALLEY WILL BE IN CLACKAMAS COUNTY...BUT IT IS POSSIBLE THROUGHOUT
THE PDX/VUO METRO AREA.
ALSO THERE IS A CHANCE THAT THE LOW OFFSHORE COULD CONTINUE TO
RAPIDLY INTENSIFY...PUSHING UP THE COAST AND DRAGGING WITH IT MORE
LOW-LEVEL SOUTHERLY FLOW IF IT MOVES ONSHORE. THIS WOULD CHANGE
EUGENE TO RAIN EARLY AND CONSIDERABLY CUT BACK ON THEIR ICE
ACCUMULATIONS...POTENTIALLY PUTTING THE PDX/VUO METRO IN THE
CROSSHAIRS FOR A MAJOR ICE EVENT. THIS APPEARS UNLIKELY...AS THE MAIN
BAROCLINIC ZONE REMAINS NEAR THE LANE/DOUGLAS COUNTY LINE...AND THIS
IS OFTEN WHERE LOWS TEND TO TRACK. MORE LIKELY THE LOW WILL APPROACH
THE COAST AND OCCLUDE AS IT ENCOUNTERS THE STRONG COLD POOL
ENTRENCHED OVER NW OREGON.
THE UPPER ENERGY MOVES ACROSS THE CASCADES EARLY SUN MORNING AND
PRECIP WILL TAPER TO SHOWERS THEREAFTER. IT IS LIKELY TEMPERATURES
WILL MODERATE JUST A BIT SUNDAY...POTENTIALLY ENOUGH TO START THAWING
OUT SOME AREAS THAT GET HIT HARD BY SNOW AND ICE TODAY AND TONIGHT.
BUCKLE YOUR SEAT BELTS FOLKS...ITS GOING TO BE AN INTERESTING RIDE
TODAY AND TONIGHT. WEAGLE
.MEDIUM AND LONG TERM...MONDAY THROUGH FRIDAY...MOST ALL AREAS WILL
BE MILDER BY MON AM...WITH TEMPERATURES ABOVE FREEZING.
HOWEVER...WITH COLD AIR STILL LOCKED IN THE COLUMBIA BASIN...WILL
STILL HAVE COLD AIR BLEEDING INTO THE GORGE. WILL KEEP AREAS OF
FREEZING RAIN IN THE GORGE AND UPPER HOOD RIVER VALLEY DURING THE
MORNING. BY AFTERNOON...MILDER AIR WILL FINALLY REACH THOSE
AREAS...WITH GRADUAL WARM UP.
MODELS ALL INDICATE A MUCH MORE PROGRESSIVE PATTERN OVER THE REGION
FOR NEXT WEEK. THIS WILL BRING RAIN...WITH SNOW CONFINED TO THE
HIGHER CASCADES. SYSTEM PASSING ACROSS REGION TUE NIGHT/WED WITH
ANOTHER STRONG FRONT ON THU. THESE WILL BRING FAIRLY DECENT ROUND OF
RAIN. SNOW LEVELS 5K FT ON TUE/TUE NIGHT...THEN SETTLE AROUND 3500
TO 4500 FT. LOOKS GOOD FOR BUILDING CASCADES SNOWPACK. ROCKEY.
&&
.AVIATION...IFR CONDITIONS PREVAILED EARLY THIS MORNING ACROSS THE S
PART OF THE FORECAST AREA WITH MVFR IN THE N. THROUGH THE MORNING...
18Z...EXPECT CONDITIONS TO REMAIN SIMILAR WITH IFR CONDITIONS S AND
MVFR PREDOMINANTLY N. AFTER SOME LIGHT FREEZING DRIZZLE THIS MORNING
IN THE N AND FREEZING RAIN IN THE S... PRECIPITATION IS LIKELY TO
RETURN TO SNOW IN THE N THIS AFTERNOON. OVERALL EXPECT IFR
CONDITIONS TO DOMINATE LATER TODAY...AFTER 18Z...ACROSS THE S...AND
AS SNOW PICKS UP IN THE N A RETURN TO PREVAILING IFR VISIBILITIES.
KPDX AND APPROACHES...LIGHT PRECIPITATION THIS MORNING IS LIKELY TO
BE AM IX OF FREEZING DRIZZLE AND SNOW. OVERALL THIS MORNING FLIGHT
CONDITIONS EXPECTED TO BE MAINLY MVFR...WITH A CHANCE FOR IFR
CONDITIONS AT TIMES. AFTER 18Z SNOW IS LIKELY TO RETURN...AND AS
THAT HAPPENS VISIBILITIES ARE LIKELY TO DROP INTO IFR CATEGORY AND
REMAIN SO THROUGH THIS EVENING...06Z.
&&
.MARINE...EASTERLY OFFSHORE WINDS EXPECTED TO WEAKEN SOME TODAY...
BRINGING AN END TO SMALL CRAFT CONDITIONS OVER THE NORTHERN WATERS.
A WEAK LOW PRES SYSTEM IS EXPECTED TO MOVE ACROSS THE SOUTHERN
WATERS THIS EVENING. WINDS ARE EXPECTED TO INCREASE BACK INTO SMALL
CRAFT RANGE WITH A FRONT MOVING E ACROSS THE WATERS SUN NIGHT AND
MON. WINDS MAY APPROACH GALE FORCE WITH ANOTHER SYSTEM TUE.
SEAS LIKELY TO REMAIN BELOW 10 FT THROUGH MON NIGHT. SWELL THROUGH
MON NIGHT WILL BE DOMINATED BY A SHORT PERIOD FRESH SWELL FROM THE S
TO SW. SEAS MAY APPROACH MID TEENS WITH THE STRONGER SYSTEM TUE AND
TUE NIGHT. &&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING FOR GREATER
PORTLAND METRO AREA-NORTHERN OREGON CASCADES-UPPER HOOD RIVER
VALLEY.
WINTER STORM WARNING FROM 10 AM THIS MORNING TO 4 AM PST SUNDAY
FOR GREATER PORTLAND METRO AREA-NORTHERN OREGON CASCADES-
UPPER HOOD RIVER VALLEY.
WINTER WEATHER ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR
CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 4 AM PST SUNDAY
FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER
GORGE.
WINTER STORM WARNING UNTIL 4 AM PST SUNDAY FOR CASCADES IN LANE
COUNTY-CENTRAL WILLAMETTE VALLEY-COAST RANGE OF NORTHWEST
OREGON-NORTHERN OREGON CASCADE FOOTHILLS.
ICE STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CASCADE
FOOTHILLS IN LANE COUNTY-SOUTH WILLAMETTE VALLEY.
WINTER WEATHER ADVISORY UNTIL 4 AM PST SUNDAY FOR LOWER
COLUMBIA.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CENTRAL
COAST RANGE OF WESTERN OREGON.
WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 10 PM PST
THIS EVENING FOR NORTH OREGON COAST.
WA...WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING FOR GREATER
VANCOUVER AREA.
WINTER STORM WARNING FROM 10 AM THIS MORNING TO 4 AM PST SUNDAY
FOR GREATER VANCOUVER AREA.
WINTER WEATHER ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR
CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 4 AM PST SUNDAY
FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER
GORGE.
WINTER WEATHER ADVISORY UNTIL 4 AM PST SUNDAY FOR I-5 CORRIDOR
IN COWLITZ COUNTY-SOUTH WASHINGTON CASCADE FOOTHILLS.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST THIS MORNING FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60
NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
519 AM CST SAT FEB 8 2014
.UPDATE...
UPDATED FOR 12Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 401 AM CST SAT FEB 8 2014/
DISCUSSION...
CURRENTLY...A MID LEVEL DISTURBANCE IS MOVING THROUGH THE LOWER
MISSISSIPPI VALLEY ATTM. LIGHT SNOW CONTINUES ROUGHLY NORTH OF A
TUNICA TO CORINTH LINE WITH A MIX OF LIGHT SNOW...SLEET AND
FREEZING RAIN TO THE SOUTH WHERE A LITTLE BIT OF WARM AIR HAS
SNUCK IN BETWEEN 950 AND 900 MB. TEMPS RANGE FROM THE UPPER TEENS
ACROSS NE AR TO LOWER 30S TOWARD MONROE COUNTY MS. SO FAR MANY
PLACES HAVE RECEIVED ABOUT AN 1/2 INCH TO AN INCH WITH UP TO 2
INCHES IN A BAND FROM POINSETT AND CROSS TOWARD TIPTON AND
LAUDERDALE COUNTIES.
TODAY...LATEST NAM AND HRRR SHOWS SOME PRECIP LINGERING THROUGH
MID MORNING. PRECIP WILL BE LIGHT WITH MAINLY LIGHT SNOW NORTH OF
THE TN/MS LINE AND A MIXTURE OF PRECIP TYPES TO THE SOUTH. PRECIP
MAY WIND DOWN AS A PERIOD OF FREEZING DRIZZLE AS WELL. AS A RESULT
DECIDED TO EXTEND THE ADVISORY UNTIL 9 AM CST. EXPECT CLOUDY
CONDITIONS THIS AFTERNOON AND WITH THE NEWLY FALLEN SNOW TEMPS
SHOULD STRUGGLE TO REACH GUIDANCE NUMBERS SO UNDERCUT THEM
SUBSTANTIALLY.
TONIGHT...CLOUDS WILL HANG IN WHICH WILL KEEP TEMPS FROM FREE
FALLING. EXPECT LOWS IN THE 20S TO LOWER 30S.
SUNDAY...NEXT ARCTIC FRONT PUSHES THOUGH DURING THE AFTERNOON.
EXPECT CLOUDY SKIES TO CONTINUE WHILE TEMPS WILL WARM AHEAD OF THE
FRONT. HIGHS WILL RANGE FROM THE UPPER 30S OVER NE AR TO LOWER
50S OVER NE MS.
SUNDAY NIGHT THROUGH MONDAY...UNSETTLED AND COLD PERIOD ACROSS
THE MIDSOUTH AS AN ARCTIC AIRMASS FILTERS IN. THE 00Z ECMWF HAS
JOINED THE GFS AND KEEPS ANY SURFACE WAVE THAT DEVELOPS ALONG THE
ARCTIC FRONT PUSHING THROUGH THE LOWER MISSISSIPPI VALLEY WELL
TO THE SOUTH. AS A RESULT PRECIP CHANCES REMAIN SMALL SUNDAY NIGHT
INTO MONDAY. IF PRECIP DOES OCCUR IT WILL BE OF THE WINTER VARIETY
ACROSS MUCH OF THE AREA. THE NAM IS THE OUTLIER NOW WITH A
SURFACE LOW MOVING FROM THE ARKLATEX INTO CENTRAL MISSISSIPPI
RESULTING IN HIGHER PRECIP CHANCES ACROSS NORTH MISSISSIPPI SUN
NIGHT INTO MONDAY. WILL NEED TO WATCH BUT FOR NOW WILL FOLLOW THE
GFS/ECMWF SOLUTION. TEMPS WILL BE BACK IN THE FREEZER BY MONDAY
WITH HIGHS IN THE 20S AND 30S.
MONDAY NIGHT INTO TUESDAY...PERHAPS THE BEST CHANCE FOR WINTER
WEATHER WILL BE DURING THIS TIME FRAME. THE ARCTIC AIRMASS WILL BE
ENTRENCHED OVER THE AREA WHILE AN UPPER LEVEL DISTURBANCE WITH
GOOD MOISTURE AND SOME LIFT PUSHES THROUGH. THE GFS IS MOST
AGGRESSIVE WITH PRECIP AMOUNTS AND SUGGESTS 1-2 INCHES OF SNOW
WITH THE ECMWF SHOWING LESSER AMOUNTS. THE NAM IS ALSO PICKING UP
THIS DISTURBANCE. AS A RESULT HAVE INCREASED POPS TO 50 PERCENT
ACROSS MUCH OF THE AREA. PRECIP TYPE WOULD BE MAINLY SNOW WITH
SOME SLEET POSSIBLE SOUTH. PRECIP WILL TAPER OFF TUESDAY WITH SOME
LINGERING SNOW OVER NORTH MISSISSIPPI. TUESDAY WILL BE COLD WITH
HIGHS IN THE 20S AND 30S.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...ARCTIC HIGH PRESSURE
LOOSES ITS GRIP ACROSS THE AREA ON WEDNESDAY AND TEMPS START TO
WARM. A POTENT UPPER TROUGH DROPS INTO THE CENTER OF THE COUNTRY
WEDNESDAY INTO WEDNESDAY NIGHT AND A SURFACE LOW BEGINS TO DEVELOP
ALONG THE EASTERN SEABOARD WITH MOST OF THE MOISTURE AND LIFT
REMAINING EAST OF THE MIDSOUTH. AS A RESULT PRECIP CHANCES ARE NOT
GREAT DURING THIS TIME FRAME.
THURSDAY AND FRIDAY...LOOKS DRY AND MILDER WITH TEMPS CLOSER TO
NORMAL.
SJM
&&
.AVIATION...
12Z TAF SET
VARIED CIGS EXPECTED AT TAF SITES THIS MORNING WITH THE LOWEST/IFR
CONDITIONS AT MEM AND MKL. FEEL THAT MORE UNIFORM MVFR CIGS WILL
SETUP FROM LATE MORNING THROUGH THE AFTERNOON. NOT CONFIDENT THAT
THIS DECK WILL REMAIN DURING THE EARLY EVENING HOURS...SO HAVE
GONE VFR FOR MOST OF THE NIGHT. AS A WEAK SYSTEM MOVES IN FROM THE
NORTHWEST MVFR CIGS MAY EASILY RETURN AFTER MIDNIGHT...ALONG WITH
SOME LIGHT FOG. IT IS ALSO POSSIBLE THAT LIGHT FREEZING DRIZZLE
MAY DEVELOP NEAR JBR AND MEM BY 09/12Z. FOR NOW CONFIDENCE IS NOT
HIGH ENOUGH FOR THIS OCCURRING. LIGHT AND VARIABLE WINDS WILL
BECOME SOUTHWEST...THEN TURN EITHER CALM OR VARIABLE LATE.
JAB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 33 30 47 28 / 30 10 10 30
MKL 32 26 46 26 / 40 10 10 30
JBR 28 25 39 22 / 20 10 10 30
TUP 39 31 53 35 / 40 10 10 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR CLAY-
CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-
MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR DUNKLIN-
PEMISCOT.
MS...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR ALCORN-
BENTON MS-CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-
LAFAYETTE-LEE MS-MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-
QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-
YALOBUSHA.
TN...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR BENTON
TN-CARROLL-CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-
HARDEMAN-HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-
MADISON-MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
520 AM CST SAT FEB 8 2014
.AVIATION...
VFR AT LBB WITH SUSTAINED WEST WINDS TICKING UP TO NEARLY 20
KNOTS BY MIDDAY. CDS ON THE OTHER HAND WILL REMAIN SOCKED IN
WITH STRATUS AND DENSE FOG FOR MUCH OF THE MORNING. RATHER
HIGH CONFIDENCE THAT VFR CONDS WILL RAPIDLY COMMENCE AROUND
18Z FOLLOWING A SURFACE TROUGH WITH DRIER WESTERLY WINDS.
&&
.PREV DISCUSSION... /ISSUED 445 AM CST SAT FEB 8 2014/
SHORT TERM...
DESPITE STEADY SW WINDS OF 10-15 KNOTS OVERNIGHT...A SURFACE
TROUGH STRUGGLED TO MAKE HEADWAY OFF THE CAPROCK AND AS A RESULT
OUR NERN COUNTIES WERE INVADED BY MOIST SE WINDS COMPLETE WITH
STRATUS AND FREEZING FOG. CONSIDERING WE HAVE NO MEANINGFUL
IMPULSES PASSING THROUGH TODAY IN THIS FLAT NW UPPER FLOW
REGIME...ANY EASTWARD ADVANCE OF THE SURFACE TROUGH WILL HEAVILY
DEPEND ON DAYTIME MIXING. SUCH FEATS USUALLY DON/T COME EASY OFF
THE CAPROCK WHEN STRATUS IS ALREADY ENTRENCHED...SO WE WILL GIVE
THE NOD TO THE HRRR WHICH KEEPS CHILDRESS AND SURROUNDING LOCALES
SOCKED IN LOW CLOUDS UNTIL CLOSE TO NOON. EARLIER CALL TO MEMPHIS
INDICATED VIS OF JUST 1.5 BLOCKS. CONDITIONS ARE DETERIORATING
ENOUGH AT CHILDRESS AND WITH LOW CLOUDS STILL EXPANDING SLOWLY
SOUTH PER 11-3.9 IMAGERY...HAVE OPTED FOR A FREEZING FOG ADVISORY
UNTIL 16Z FOR OUR NERN COUNTIES.
THE OTHER CHALLENGE TODAY IS MAX TEMPS. ANYONE VIEWING OUR MAX
TEMP GRID IN NDFD MIGHT THINK WE/RE PAYING HOMAGE TO PICASSO...
BUT THIS IS SOLELY THE RESULT OF A STUBBORN SNOWPACK/HIGH ALBEDO
FROM GRAHAM NORTHEAST TO GUTHRIE. FARTHER WEST...DRY SOILS AND
15-20 MPH WEST WINDS BY PEAK HEATING WILL EASILY PUSH HIGHS INTO
THE 60S...PERHAPS EVEN 70 IN A FEW SPOTS. ALONG THESE LINES...
AFTERNOON RH VALUES WILL TUMBLE INTO THE UPPER TEENS...BUT THE
SHORT DURATION OF THESE LOW HUMIDITIES /90 MIN OR LESS/ SEEMS
UNSUPPORTIVE OF EVEN A RANGELAND FIRE DANGER STATEMENT AT THIS
TIME.
EXPECT EVEN MILDER LOWS TONIGHT UNDER INCREASING HIGH CLOUDS AND
WIDESPREAD WESTERLY WINDS AOA 10 MPH.
LONG TERM...
BIGGEST CHANGE IN THE MODELS HAS BEEN WITH PRECIPITATION CHANCES
FOR MONDAY EVENING INTO TUESDAY MORNING. MODELS HAVE CHANGED TO A
DRIER FORECAST THAN IN PREVIOUS RUNS BUT THE INCOMING 06Z RUNS ARE
GOING BACK TOWARDS A BIT MORE PRECIP THAN THE 00Z RUNS DID. PART
OF THIS APPEARS TO BE A CONTINUED SLOWER TREND WITH THE PASSAGE OF
THE WAVE. ONLY SIMILARITY IN THE GRIDS IS THAT THERE IS A MEAGER
AMOUNT OF MOISTURE AVAILABLE FOR THIS SYSTEM SO ANY PRECIPITATION
THAT DOES OCCUR SHOULD BE ON THE LIGHT SIDE. WITH ADDED
UNCERTAINTY ON THE TIMING...OPTED TO KEEP THE POP GRIDS UNCHANGED
FOR NOW TO SEE IF THE MODELS WILL CONTINUE THE TREND OF SLOWING
THE WAVE DOWN OR IF THEY SPEED THE TIMING UP ONCE AGAIN. OTHER
CHANCE WAS IN TEMPERATURES ACROSS THE REGION WITH GUIDANCE COMING
IN ABOUT 10 TO 15 DEGREES WARMER THAN PREVIOUS RUNS. WITH THE COLD
FRONT ARRIVING ON LATE SUNDAY/EARLY MONDAY AND A CONTINUED NORTH
TO NORTHEASTERLY SURFACE FLOW...FEEL THAT THE MODELS ARE ERODING
THE COLD AIR TOO FAST AND UNDERCUT MEX GUIDANCE AND REMAINED CLOSE
TO WHAT THE PREVIOUS FORECAST HAD.
BEYOND TUESDAY...NORTHWESTERLY FLOW ALOFT LOOKS TO REMAIN IN PLACE
ACROSS THE REGION. THIS SHOULD ALLOW WEAK LEE SURFACE TROFING TO
TAKE PLACE AND BEGIN A GRADUAL WARMUP IN TEMPERATURES BACK INTO
THE MID TO UPPER 60S.
JORDAN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 63 31 59 20 38 / 0 0 0 10 10
TULIA 62 30 56 20 33 / 0 0 10 10 10
PLAINVIEW 64 30 59 21 34 / 0 0 10 10 10
LEVELLAND 68 33 67 23 40 / 0 0 0 10 10
LUBBOCK 68 32 63 22 38 / 0 0 0 10 10
DENVER CITY 68 35 70 24 43 / 0 0 0 10 10
BROWNFIELD 68 33 69 24 41 / 0 0 0 10 10
CHILDRESS 48 27 40 21 31 / 0 0 10 10 10
SPUR 51 22 49 23 34 / 0 0 0 10 10
ASPERMONT 64 29 59 24 35 / 0 0 0 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: TXZ024>026-031-032.
&&
$$
93
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
445 AM CST SAT FEB 8 2014
.SHORT TERM...
DESPITE STEADY SW WINDS OF 10-15 KNOTS OVERNIGHT...A SURFACE
TROUGH STRUGGLED TO MAKE HEADWAY OFF THE CAPROCK AND AS A RESULT
OUR NERN COUNTIES WERE INVADED BY MOIST SE WINDS COMPLETE WITH
STRATUS AND FREEZING FOG. CONSIDERING WE HAVE NO MEANINGFUL
IMPULSES PASSING THROUGH TODAY IN THIS FLAT NW UPPER FLOW
REGIME...ANY EASTWARD ADVANCE OF THE SURFACE TROUGH WILL HEAVILY
DEPEND ON DAYTIME MIXING. SUCH FEATS USUALLY DON/T COME EASY OFF
THE CAPROCK WHEN STRATUS IS ALREADY ENTRENCHED...SO WE WILL GIVE
THE NOD TO THE HRRR WHICH KEEPS CHILDRESS AND SURROUNDING LOCALES
SOCKED IN LOW CLOUDS UNTIL CLOSE TO NOON. EARLIER CALL TO MEMPHIS
INDICATED VIS OF JUST 1.5 BLOCKS. CONDITIONS ARE DETERIORATING
ENOUGH AT CHILDRESS AND WITH LOW CLOUDS STILL EXPANDING SLOWLY
SOUTH PER 11-3.9 IMAGERY...HAVE OPTED FOR A FREEZING FOG ADVISORY
UNTIL 16Z FOR OUR NERN COUNTIES.
THE OTHER CHALLENGE TODAY IS MAX TEMPS. ANYONE VIEWING OUR MAX
TEMP GRID IN NDFD MIGHT THINK WE/RE PAYING HOMAGE TO PICASSO...
BUT THIS IS SOLELY THE RESULT OF A STUBBORN SNOWPACK/HIGH ALBEDO
FROM GRAHAM NORTHEAST TO GUTHRIE. FARTHER WEST...DRY SOILS AND
15-20 MPH WEST WINDS BY PEAK HEATING WILL EASILY PUSH HIGHS INTO
THE 60S...PERHAPS EVEN 70 IN A FEW SPOTS. ALONG THESE LINES...
AFTERNOON RH VALUES WILL TUMBLE INTO THE UPPER TEENS...BUT THE
SHORT DURATION OF THESE LOW HUMIDITIES /90 MIN OR LESS/ SEEMS
UNSUPPORTIVE OF EVEN A RANGELAND FIRE DANGER STATEMENT AT THIS
TIME.
EXPECT EVEN MILDER LOWS TONIGHT UNDER INCREASING HIGH CLOUDS AND
WIDESPREAD WESTERLY WINDS AOA 10 MPH.
&&
.LONG TERM...
BIGGEST CHANGE IN THE MODELS HAS BEEN WITH PRECIPITATION CHANCES
FOR MONDAY EVENING INTO TUESDAY MORNING. MODELS HAVE CHANGED TO A
DRIER FORECAST THAN IN PREVIOUS RUNS BUT THE INCOMING 06Z RUNS ARE
GOING BACK TOWARDS A BIT MORE PRECIP THAN THE 00Z RUNS DID. PART
OF THIS APPEARS TO BE A CONTINUED SLOWER TREND WITH THE PASSAGE OF
THE WAVE. ONLY SIMILARITY IN THE GRIDS IS THAT THERE IS A MEAGER
AMOUNT OF MOISTURE AVAILABLE FOR THIS SYSTEM SO ANY PRECIPITATION
THAT DOES OCCUR SHOULD BE ON THE LIGHT SIDE. WITH ADDED
UNCERTAINTY ON THE TIMING...OPTED TO KEEP THE POP GRIDS UNCHANGED
FOR NOW TO SEE IF THE MODELS WILL CONTINUE THE TREND OF SLOWING
THE WAVE DOWN OR IF THEY SPEED THE TIMING UP ONCE AGAIN. OTHER
CHANCE WAS IN TEMPERATURES ACROSS THE REGION WITH GUIDANCE COMING
IN ABOUT 10 TO 15 DEGREES WARMER THAN PREVIOUS RUNS. WITH THE COLD
FRONT ARRIVING ON LATE SUNDAY/EARLY MONDAY AND A CONTINUED NORTH
TO NORTHEASTERLY SURFACE FLOW...FEEL THAT THE MODELS ARE ERODING
THE COLD AIR TOO FAST AND UNDERCUT MEX GUIDANCE AND REMAINED CLOSE
TO WHAT THE PREVIOUS FORECAST HAD.
BEYOND TUESDAY...NORTHWESTERLY FLOW ALOFT LOOKS TO REMAIN IN PLACE
ACROSS THE REGION. THIS SHOULD ALLOW WEAK LEE SURFACE TROFING TO
TAKE PLACE AND BEGIN A GRADUAL WARMUP IN TEMPERATURES BACK INTO
THE MID TO UPPER 60S.
JORDAN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 63 31 59 20 38 / 0 0 0 10 10
TULIA 62 30 56 20 33 / 0 0 10 10 10
PLAINVIEW 64 30 59 21 34 / 0 0 10 10 10
LEVELLAND 68 33 67 23 40 / 0 0 0 10 10
LUBBOCK 68 32 63 22 38 / 0 0 0 10 10
DENVER CITY 68 35 70 24 43 / 0 0 0 10 10
BROWNFIELD 68 33 69 24 41 / 0 0 0 10 10
CHILDRESS 48 27 40 21 31 / 0 0 10 10 10
SPUR 51 22 49 23 34 / 0 0 0 10 10
ASPERMONT 64 29 59 24 35 / 0 0 0 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: TXZ024>026-031-032.
&&
$$
93/14
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1027 AM MST SAT FEB 8 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 411 AM MST SAT FEB 8 2014
FORECAST CONCERNS WILL BE CHANCES OF PRECIPITATION AND HIGH
TEMPERATURES INTO THE BEGINNING OF NEXT WEEK. SATELLITE SHOWING A
CHANGING FLOW PATTERN FROM THE PACIFIC INTO NORTH AMERICA. FLOW
OVER THE WESTERN AND CENTRAL PACIFIC REMAINS AMPLIFIED AND
RETROGRESSIVE. SINCE THE LARGE UPPER RIDGE AND TROUGH HAVE PULLED
FURTHER WEST...THIS HAS ALLOWED A NEARLY ZONAL AND FAST/PROGRESSIVE
FLOW TO DEVELOP FROM THE EASTERN PACIFIC INTO THE ATLANTIC. NUMEROUS
SHORTWAVE TROUGHS AND A LARGE AMOUNT OF MID AND UPPER LEVEL MOISTURE
ARE EMBEDDED WITHIN THIS FLOW. LOW LEVEL AIR MASS HAS MODIFIED OVER
THE LAST 24 HOURS. HOWEVER...THE EXTENSIVE SNOWFIELD AND CLOUD COVER
CONTINUE TO HOLD DOWN TEMPERATURES TO BELOW NORMAL.
AT JET LEVEL...MODELS INITIALIZED FINE AT JET LEVEL. AT MID
LEVELS...MODELS INITIALIZED WELL WITH THE ECMWF...UKMET...CANADIAN
AND GFS DOING THE BEST. THE ECMWF WAS DOING THE BEST ON THE SURFACE
WIND PRESSURE FIELD. IT WAS HANDLING THE SURFACE TROUGH TO OUR WEST
VERY WELL. THE ECMWF WAS DOING A LITTLE BETTER THAN THE GFS ON THE
LOW LEVEL THERMAL FIELD. THE NAM WAS DOING THE WORST. MODELS TENDED
TO NOT HAVE THE COLD AIR FAR ENOUGH SOUTH AND WEST OVER THE CENTRAL
PLAINS.
TODAY/TONIGHT...INITIAL PROBLEM WILL BE FOG AND STRATUS TO THE EAST
OF SURFACE TROUGH. HRRR AND RAP HAVE A GOOD HANDLE ON WHAT IS GOING
ON. BOTH OF THESE ARE SHOWING FOG IN THE SOUTHEAST AND EASTERN
PORTION THROUGH LATE MORNING. LEFT FRONT QUADRANT OF JET MOVES
INTO/ACROSS THE AREA IN THE AFTERNOON WHICH IS SLOWER THAN YESTERDAY.
AT THIS TIME...ONLY MID AND UPPER LEVEL CLOUD COVER IS ASSOCIATED
WITH THIS FEATURE. THIS FEATURE MOVES NORTH AND EAST OF THE AREA BY
LATE EVENING.
THERE IS LITTLE TO NO MOISTURE WITH THIS INITIAL JET AND MID LEVEL
LIFT. SO KEPT FLURRIES IN THIS AREA. STRONG COLD FRONT BLASTS INTO
THE AREA DURING THE EVENING. ANOTHER LEFT FRONT QUADRANT OR JET AXIS
MOVES INTO OR OVER THE SOUTHWEST PORTION VERY QUICKLY AFTER MIDNIGHT.
DEPENDING ON WHICH MODEL YOU USE...IT IS POSSIBLE THAT A COUPLED JET
STRUCTURE COULD BE OVER THE AREA...ESPECIALLY FOR THE NORTHEAST
PORTION BY 12Z. DEEPER MOISTURE AND COLD AIR ESTABLISHES ITSELF
THROUGH THE NIGHT WITH THE BEST MOISTURE AFTER 06Z AND IN THE FAR
NORTH.
SOUNDINGS...MOISTURE DEPTH AND LIFT SUPPORT GOING CHANCE IN THE NORTH
AND THEN TAPERING OFF TO SLIGHT CHANCE AND FLURRIES IN THE FAR
SOUTH. PRIOR TO THE AIR MASS GETTING COLD ENOUGH AND GETTING THE
DEEPER MOISTURE...THE STRONG UPSLOPE FLOW...SOUNDING PROFILE...AND
MORE THAN ONE MODEL INDICATE THAT FOG WILL DEVELOP BEHIND THE FRONT
SO ADDED THAT IN.
TRICKY HIGH TEMPERATURE FORECAST AS MODEL DIFFERENCES CONTINUE. ONE
TREND THAT HAS OCCURRED SINCE YESTERDAY IS THEY ARE WARMER...
ESPECIALLY IN THE SOUTHWEST HALF. PER INITIAL ANALYSIS AND
CONSISTENCY BELIEVE THE ECMWF HAS THE RIGHT IDEA ON THE ARRIVAL OF
A PRESSURE/COOL SURGE BY LATE MORNING. MOST OF THE NORTH AND EAST
WILL REMAIN IN THE COOL AIR WITH LIGHT WINDS...SNOW COVER...
LINGERING LOW LEVEL CLOUD COVER AND INCREASING MID/UPPER LEVEL CLOUD
COVER. REMAINDER OF THE AREA GETS DOWNSLOPE WINDS. HOWEVER IT WILL
STILL HAVE TO CONTEND WITH THE MID/UPPER CLOUD COVER AND SNOWFIELD.
GOING BY WHAT WENT ON YESTERDAY WITH TEMPERATURES TO OUR WEST...
BELIEVE THE MODELS MAY BE TOO WARM. SO TENDED TO GO TOWARD THE
LOWER END OF GUIDANCE.
SUNDAY/SUNDAY NIGHT...ABOVE MENTIONED JET SHIFTS TO OVER THE
NORTHEAST PORTION OF THE AREA OR JUST TO THE NORTHEAST OF THE AREA BY
18Z AND CONTINUES TO MOVE SLOWLY NORTH THROUGH THE REST OF THE
AFTERNOON. SYNOPTIC AND MESOSCALE LIFT COMBINED WITH THE SOUNDINGS
SUPPORT HAVING NORTHEAST HALF HAVING THE HIGHEST CHANCE OF SNOW IN
THE MORNING. MOISTURE AND LIFT DECREASE A LITTLE IN THE AFTERNOON
BEFORE THE NEXT BATCH OF LIFT AND MOISTURE MOVE INTO THE AREA DURING
THE NIGHT. SO FOR THE AFTERNOON WILL HAVE A LOW CHANCE OF SNOW. COLD
AIR ADVECTION...UPSLOPE WINDS/CLOUD COVER AND PRECIPITATION WILL KEEP
THE TEMPERATURES FROM RISING MUCH AND LOWERED MAXES OR KEPT THEM
LOW. POSSIBLE THAT I STILL MAY BE TOO WARM.
RIGHT BEHIND FIRST JET COMES IN ANOTHER LEFT FRONT QUADRANT OF
ANOTHER JET. BY 06Z...THE GFS AND ECMWF ARE SHOWING A COUPLED JET
STRUCTURE WITH THE RIGHT REAR QUADRANT OF THE NORTHERN JET AND THE
LEFT FRONT QUADRANT OF THE NEW SOUTHERN JET COMING IN. THEY KEEP THIS
OVER THE AREA THROUGH THE REST OF THE NIGHT. MOISTURE DEPTH AND
SATURATION CONTINUE TO INCREASE AND REALLY IS THE BEST OUT OF ANY
SHORT TERM PERIOD. ALSO THE THETA-E LAPSE RATES ARE VERY CLOSE TO
ZERO. SO ALL THINGS CONSIDERED...RAISED POPS TO A HIGH CHANCE. POPS
MAY STILL NEED TO BE RAISED SOME MORE.
MONDAY/MONDAY NIGHT...ABOVE MENTIONED JET STRUCTURE OR RIGHT REAR
QUADRANT OF NORTHERN JET MOVE A LITTLE FURTHER SOUTH BY 18Z AND
CONTINUE TO AFFECT THE AREA...MOSTLY SOUTH. ABOVE MENTIONED JET LIFT
LOOKS TO MOVE SOUTH OF THE AREA DURING THE EVENING. SO KEPT SOME
CHANCE POPS IN THE MORNING WITH FLURRIES IN THE AFTERNOON. THE
NIGHT LOOKS DRY. NOTHING REALLY SHOWS VERY MUCH WARMING FOR MAXES.
SO LOWERED MAXES FROM PREVIOUS FORECAST. HOWEVER...CONSIDERING THE
VERY COLD AIR IN PLACE AND A LINGERING SNOW FIELD...ADDITIONAL
COOLING OF MAXES MAY BE NEEDED.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 411 AM MST SAT FEB 8 2014
FOR THE MOST PART THIS PERIOD WILL REMAIN DRY EXCEPT FOR THURSDAY
NIGHT AS A SUBTLE UPPER LEVEL SHORT WAVE TROUGH AND A PLUME OF
1000-500MB MOISTURE MOVE ACROSS THE AREA. OTHERWISE MODELS DISAGREE
WITH THE PROGRESSION OF THE TWO UPPER LEVEL SHORT WAVE TROUGHS IN
THE NORTHWEST FLOW DURING THIS PERIOD...WHICH WILL AFFECT NOT ONLY
PRECIP. CHANCES BUT ALSO COLD FRONT ARRIVAL BOTH MID WEEK AND LATE
WEEK. AM NOT TOO CONFIDENT WITH PRECIP. CHANCES FOR THURS NIGHT BUT
THE MEAN OF THE GFS ENSEMBLE MEMBERS IS FAVORING THE ECMWF 500MB
PATTERN THURS. NIGHT. WITH ECMWF QPF FAVORING THE CONSENSUS OUTPUT
AM INCLINED TO GO WITH CONSENSUS WHICH PLACES PRECIP. CHANCES OVER
THE NORTHERN HALF OF THE AREA.
OTHERWISE GENERAL TREND IN TEMPERATURES WILL BE WARMER BEHIND WARM
FRONT THAT MOVES THROUGH TUESDAY...POSSIBLY WARMING A FEW DEGREES
ABOVE NORMAL BY THE END OF THE WORK WEEK. DUE TO DISCREPANCIES IN
FRONTAL TIMING AFTER TUESDAY...HARD TO TREND TEMPERATURES AWAY FROM
CONSENSUS OUTPUT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1017 AM MST SAT FEB 8 2014
VFR CONDITIONS ARE EXPECTED AT KGLD AND KMCK TODAY AHEAD OF A COLD
FRONT THAT WILL MOVE INTO THE AREA LATER THIS EVENING. CONDITIONS
WILL DETERIORATE TO MVFR WITH THE COLD FRONT AND THEN WORSEN TO
IFR WITH SOME LIGHT SNOW. FORECAST SOUNDINGS INDICATE THAT CONDITIONS
WILL IMPROVE TO MVFR AFTER SUNRISE SUNDAY MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...FS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1212 PM CST SAT FEB 8 2014
.UPDATE...
ISSUED AT 1158 CST SAT FEB 8 2014
COMPLEX CLOUD AND TEMPERATURE FORECAST. PATCHY LIGHT SNOW AND
FLURRIES WITH THE FIRST SHORTWAVE TROF HAVE MOVED OUT OF THE
AREA/DISSIPATED. THE NEXT SHORTWAVE IS ALREADY SPREADING CLOUDS
BACK INTO THE FORECAST AREA. WARMER TEMPERATURES IN THE SOUTH AND
COLDER TEMPERATURES IN THE NORTHWEST WITH ONGOING COLD AIR
ADVECTION. A 130KT JET DIVES INTO THE PLAINS THIS AFTERNOON AND
MID LEVEL FRONTOGENESIS/UVV/WARM AIR ADVECTION INCREASES. THE
SHORT RANGE MODELS SPREAD A BAND OF LIGHT SNOW ACROSS THE AREA.
THE HOPWRF SEEMS TO BE DOING A GOOD JOB WITH THE SNOW. LOOKS LIKE
SNOW WILL INCREASE ACROSS THE AREA BETWEEN 22Z-02Z THE
FRONTOGENESIS MAY FOCUS ACCUMULATING LIGHT SNOW WHERE A QUICK INCH
COULD FALL. WITH THE MORNING UPDATE...TRIED TO ACCOUNT FOR THE
SNOW ENDING IN THE MORNING AND CHANCES RETURNING IN THE AFTERNOON
ALONG WITH VARIABLE CLOUD COVER. LOOKED LIKE THE NORTH MAY
STRUGGLE TO REACH HIGHS...SO TWEAKED HIGHS DOWNWARD...HOWEVER IN
THE SOUTH...TEMPERATURES MAY RISE A LITTLE MORE THAN FORECAST.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 300 AM CST SAT FEB 8 2014
TIMING/STRENGTH OF ANY POPS MAIN ISSUE...MAINLY TONIGHT AND
SUNDAY...WITH LINGERING LOW CLOUDS SOUTH TODAY AND MIN TEMPS BY
MONDAY MORNING OTHER CONCERNS.
ALTHOUGH LIGHT SNOW...MOSTLY FLURRIES...HAVE BEEN PREVALENT
OVERNIGHT...RADAR RETURNS HAD INCREASED SOMEWHAT AFTER 06Z IN
NERN ZONES. THIS IS IN ADVANCE OF COMPACT AND WELL DEFINED VORT
MAX OVER NCNTRL NEBR/SCNTRL SD VICINITY AT 07Z PER SATELLITE
IMAGERY. THIS DISTURBANCE WAS FORECAST TO BE EAST OF THE FORECAST
AREA BY 18Z THUS WOULD SUSPECT ANY MEASURABLE PRECIP NRN/ECNTRL
ZONES WOULD END FAIRLY QUICKLY THIS MORNING AND POSSIBLY EVEN BE
MOSTLY E OF FA BY 12Z. ALTHOUGH THIS SYSTEM WAS ALSO CLEARING OUT
LOW CLOUDS PARTS OF WRN/NRN NEBR...BUT WITH TRAILING MID/HIGH
CLOUDS...IT WAS HAVING LESS SUCCESS CLEARING LOW CLOUDS OUT
ACROSS THE SOUTH. SHORT RANGE HRRR BASICALLY LEFT THESE LOW CLOUDS
IN ALL DAY SO DELAYED CLEARING FAR SOUTH. ALSO WITH SLOWER
CLEARING PARTS OF THE EAST/SOUTH...LOWERED HIGHS A BIT.
LIKEWISE...RAISED MINS TO AROUND 10 SOUTH FOR TONIGHT AS COLD
ADVECTION ONLY MODEST BEHIND FRONT.
FAST UPPER FLOW WITH SEVERAL EMBEDDED WAVES AND TIMING/LOCATION
DIFFERENCES BETWEEN 00Z NAM/GFS AND ECMWF IN QPF PLACEMENT CREATE
A OVER-SMOOTHED OR OVER-SIMPLIFIED PRECIP FORECAST POTENTIAL. BUT
OTHER THAN GOING FOR AN ALL-OR-NOTHING BY FOLLOWING ONE
PARTICULAR MODEL...IT PROBABLY IS ABOUT THE BEST WAY TO HANDLE
IT. THUS...BROUGHT IN SMALL POPS WRN ZONES LATE THIS AFTN PER GFS
AND THEN INCREASED THEM TO CHC CATEGORY ACROSS A WIDE WEST TO
EAST SWATH THIS EVENING PER MODELS BUT ALSO MENTIONED SMALL
CHANCES N TO ACCOUNT FOR THE FARTHER N ECMWF. THEN FOR SUNDAY
INCREASED POPS BACK INTO CHC CATEGORY S USING MORE OF THE ECMWF.
A QUICK LOOK AT THE 06Z NAM SUGGESTED SHOWED THAT MODEL COMING IN
DRIER THAN ITS PRIOR RUN AND LOOKING MORE LIKE THE DRY 00Z GFS.
THUS MADE A FEW LAST MINUTE CHANGES...MAINLY LOWERED AFTN POPS
QUICKER.
AIRMASS PRESSING DOWN BEHIND WAVE ON SUNDAY IS PRETTY COLD AND
WITH SFC RIDGE AXIS BUILDING DOWN THE MO RIVER VALLEY...POTENTIAL
FOR VERY COLD TEMPERATURES STILL EXISTS. MAIN CAVEAT WOULD BE IF
MID CLOUDS SPREAD BACK OVER AREA PER 00Z GFS...FOR THAT REASON
KEPT ERN ZONES THE COLDEST BUT BLENDED WRN COUNTIES INTO WARMER
NEIGHBORS NUMBERS WHICH RAISED THEM A FEW DEGREES.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 300 AM CST SAT FEB 8 2014
FAST FLOW ALSO LENDS FOR POTENTIAL MODEL SOLUTION FLIP-FLOPPING
WITH ECMWF A GOOD EXAMPLE. YDA THE 00Z RUN SUGGESTED A MIDWEEK
WAVE WOULD PUSH A MODEST COLD FRONT INTO FORECAST AREA BY
THURSDAY...BUT MOST RECENT 00Z RUN HAD A TRAILING WAVE SPREADING
DECENT WARM ADVECTION ACROSS FA INTO THURSDAY MORNING AND THEN
COOL ADVECTION WEAK ENOUGH TO ALLOW GOOD MIXING AND VERY MILD
TEMPS BY AFTN. MEANWHILE...GFS WAS STRONGER WITH COLD ADVECTION
INTO THURSDAY MORNING AND MUCH COLDER WITH FORECAST HIGHS.
THUS...DECIDED TO LEAVE IN A BLEND OF PRIOR RUN/PREVIOUS FORECAST
FOR MAX TEMPERATURES AND HANDLE ANY ADJUSTMENTS WHEN MODELS BECOME
MORE IN-LINE AND CONSISTENT. DID LOWER LOWS ACROSS THE EAST TUE AM
SINCE THAT AREA WILL BE LAST TO FEEL OVERNIGHT IMPACTS OF RETURN
FLOW/WARM ADVECTION PER GENERAL CONSENSUS AMONG MODELS. AS FOR
PRECIP...ADDED SLIGHT CHC SNOW POPS TO FRIDAY OTHERWISE EXTENDED
WAS DRY. YDAS 12Z ECMWF WAS FAIRLY STRONG WITH SHORT-WAVE ENERGY
ACTING ON A STALLING COLD FRONT GENERATING A LARGE SWATH OF
MODESTLY HIGH QPF ACROSS ERN NEBR/WRN IA. ALTHOUGH 00Z RUN BACKED
MARKEDLY OFF THAT SOLUTION...IT DID KEEP A WEAK WAVE MOVG TOWARD
AREA BY 00Z SAT WITH A SCATTERING OF LIGHT QPF OVER PLAINS WITH
SOME HINT OF SAME PER 00Z GFS.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1145 CST SAT FEB 8 2014
COMPLEX CLOUD/PRECIPITATION FORECAST TODAY. THE FIRST SHORTWAVE IS
EXITING THE AREA AND KOMA AND KLNK ARE ON THE EDGE OF THE MVFR
CIGS AND KOMA HAS HAD A PATCH OF MVFR VSBYS WITH LIGHT SNOW. KLNK
HAS SCATTERED OUT AND KOFK WAS CLEAR. MID CLOUD CEILINGS ARE
ALREADY THICKENING FROM FL060-100 AND HAVE ADVANCED ACROSS
NEBRASKA. BY MID AND LATE AFTERNOON COULD SEE SOME RESTRICTIONS
IN VSBYS DUE TO THE LOWERING CLOUDS AND FLURRIES. DETERIORATING
CONDITIONS EARLY IN THE EVENING WITH MORE WIDESPREAD MVFR CIGS AND
VSBYS IN LIGHT SNOW. THE STORM SYSTEM MOVES OUT BETWEEN 06Z-
12Z...WITH IMPROVING CIGS/VSBYS. SOUTHWEST TO NORTHWEST WINDS
5-10KTS BECOME NORTH AND INCREASE 10-15KTS AFTER 09Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...ZAPOTOCNY
SHORT TERM...CHERMOK
LONG TERM...CHERMOK
AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS ELKO NV
241 PM PST SAT FEB 8 2014
.SYNOPSIS...ABUNDANT PACIFIC MOISTURE WILL BRING VALLEY RAINS AND
MOUNTAIN SNOWS THROUGH THE WEEKEND. DRIER WEATHER WILL RETURN LATE
MONDAY AND TUESDAY AS HIGH PRESSURE TRIES TO BUILD INTO THE REGION.
MORE MOISTURE IS POSSIBLE LATER IN THE WEEK...WITH SHOWERS MAKING
A RETURN BY WEDNESDAY AND THURSDAY.
&&
.SHORT TERM...TONIGHT THROUGH TUESDAY. SATELLITE IMAGERY THIS
AFTERNOON IS DEPICTING ABUNDANT MOISTURE AND CLOUDS PUSHING EAST
FROM NORTHERN CALIFORNIA. RADAR IS FILLING IN ACROSS NORTHERN
NEVADA AS MOISTURE IS MAKING ITS WAY EAST ACROSS THE SIERRA
NEVADA. LATEST 3KM HRRR IS SHOWING A GRADUAL INCREASE IN THE AREAL
COVERAGE OF SHOWER ACTIVITY OVER NORTHERN NEVADA LATER THIS
AFTERNOON AND EVENING.
MODELS ARE SHOWING A STRONG 250MB JET OF ABOUT 130+ KNOTS JUST
OVER THE NEVADA BORDER OF UTAH THIS AFTERNOON. MODELS ARE SHOWING
A VORT MAX IN THE FLOW THAT WILL CROSS THE FORECAST AREA THROUGH
THE EVENING. DID NOT MAKE MANY CHANGES TO THE OVERNIGHT FORECAST
AS POPS LOOK GOOD. WILL KEEP THE WINTER STORM WARNING GOING FOR
THE RUBY MOUNTAINS AS RADAR IMAGERY SHOWING MODERATE SNOW GOING
ON THERE AT THIS TIME.
ALL MODELS CONTINUE TO SHOW A MOIST FLOW ON SUNDAY. NAEFS MEAN
INTEGRATED WATER VAPOR TRANSPORT FORECAST SHOWS WELL ABOVE NORMAL
MOISTURE TRANSPORT OVER THE REGION. HAVE KEPT POPS AT OR NEAR 100
NORTH OF US HIGHWAY 50. MOISTURE STARTS TO WANE SUNDAY NIGHT AND
MONDAY WITH CHANCES FOR PRECIPITATION DECREASING WEST TO EAST.
HEIGHTS START TO BUILD DURING THE MONDAY MORNING TIME FRAME
THROUGH TUESDAY AS HIGH PRESSURE TRIES TO BUILD IN TO THE AREA.
TEMPERATURES THROUGH THE PERIOD WILL REMAIN ABOVE NORMAL.
.LONG TERM...TUESDAY NIGHT THROUGH NEXT SATURDAY. MODELS IN GOOD
AGREEMENT THROUGH THURSDAY THEN DIFFERENCES EMERGE WITH EC A BIT
COOLER WITH LOWER 500MB HEIGHTS LATE THURSDAY AND FRIDAY ALSO
DIFFERENCES ON TIMING OF PRECIPITATION AFTER THURSDAY.
TUESDAY NIGHT THROUGH THURSDAY. ZONAL FLOW WITH VERY BROAD RIDGE
WILL BRING COPIOUS AMOUNTS OF MOISTURE TO NORTHERN NEVADA WITH PW`S
2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL...ALSO THE INTEGRATED WV
TRANSPORT SHOWS 4 TO 5 STANDARD DEVIATIONS ABOVE NORMAL. I OPTED TO
INCREASE POPS QUITE A BIT AS MODELS ARE IN VERY GOOD AGREEMENT WITH
PRECIPITATION DURING THE PERIOD AS WELL AS CLIMO POPS AROUND 40
PERCENT WITH THIS TYPE OF SYNOPTIC PATTERN. DURING THE DAY ON
THURSDAY RAIN SHOULD TAPER OFF AS RIDGE STRENGTHENS SLIGHTLY OVER
THE GREAT BASIN WHICH WILL LIFT PRECIPITATION TO NEAR NORTHERN
NEVADA BORDER.
THURSDAY NIGHT THROUGH SATURDAY. PLENTY OF DISAGREEMENT BETWEEN
MODELS ON 700MB TEMPS AND PRECIPITATION DURING PERIOD SO DID NOT
CHANGE MUCH FROM PREVIOUS FORECAST AS CONFIDENCE IS LOWER DURING
THIS PERIOD. HOWEVER EXPECT MAINLY ZONAL PATTERN WITH PERIODS OF
RAIN POSSIBLE WITH TROUGH DIGGING A BIT IN EASTERN PACIFIC THIS WILL
STRENGTHEN THE RIDGE SLIGHTLY OVER THE GREAT BASIN...BUT MODELS
DISAGREE ON HOW MUCH THE TROUGH WILL DIG AT THIS POINT THUS
INFLUENCING THE STRENGTH OF THE RIDGE OVER THE REGION.
&&
.AVIATION...CEILINGS WILL MAINLY BE VFR WITH PERIODS OF RAIN AND
MVFR CIGS AT KEKO KWMC AND KELY LIKELY. KTPH EXPECTED TO BE VFR WITH
A 20 PERCENT CHANCE OF RAIN MAINLY THIS EVENING.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 4 PM PST MONDAY FOR RUBY
MOUNTAINS/EAST HUMBOLDT RANGE.
&&
$$
86/90/90
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EST SAT FEB 8 2014
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL CROSS THE SOUTHEAST
STATES TODAY... AS SURFACE HIGH PRESSURE OVER THE AREA WEAKENS. A
WEAK LOW PRESSURE TROUGH WILL HOLD OVER THE CAROLINAS TONIGHT
THROUGH SUNDAY NIGHT. A LOW PRESSURE SYSTEM WILL APPROACH FROM THE
WEST EARLY NEXT WEEK.
&&
.NEAR TERM /TODAY/...
AS OF 930 AM SATURDAY...
SHORTWAVE ENERGY OVER THE SOUTHERN APPALACHIANS/SAVANNA RIVER VALLEY
WILL QUICKLY MOVE ENE AND OFF THE CAROLINA COAST BY MIDDAY.
SATELLITE AND OBSERVATION TRENDS SUPPORT WHAT THE HRRR AND THE WRF-
ARW SHOWED YESTERDAY EVENING...WITH THE PRECIP HUGGING THE COASTAL
SECTIONS OF THE CAROLINAS AND GEORGIA...OWING TO THE CONSIDERABLE
LOW-LEVEL FORCING FROM A COMBINATION OF STRONG LOW-MOISTURE FLUX
CONVERGENCE AND FRONTOGENESIS ASSOCIATED WITH THE OFFSHORE LOW
PRESSURE SYSTEM AND BAROCLINIC FRONTAL ZONE. WITH PRECIP CONFINED
TO THE COASTAL SECTIONS...THERE WILL BE NO P-TYPE ISSUES...WITH ALL
RAIN WITH PRECIP AMOUNTS AROUND A TENTH OF AN INCH OVER
SAMPSON...WAYNE COUNTIES.
BY 18Z...LOW-LEVEL VEERING AROUND TO WESTERLY WILL ADVECT DRIER AIR
INTO THE AREA...ENDING PRECIP CHANCES AS FORCING SHIFTS OFFSHORE
WITH PARTIAL CLEARING SPREADING EASTWARD. HIGHS TODAY IN THE MID 40
TO LOWER 50S...WARMEST SW. -CBL
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 AM SATURDAY...
ANOTHER WEAK SHORTWAVE TROUGH (NOW WELL BACK OVER THE ROCKIES)
CROSSES THE AREA LATE TONIGHT INTO SUNDAY MORNING... ACCOMPANIED BY
ANOTHER SURGE IN UPPER DIVERGENCE. WHILE THE BULK OF THE MOISTURE
WITH THIS APPEARS TO ZIP BY QUICKLY TO OUR NORTH... THERE LOOKS TO
BE JUST ENOUGH LOW LEVEL MOISTURE AND WEAK MASS CONVERGENCE ALONG A
DEVELOPING SURFACE TROUGH OVER THE FOOTHILLS/WRN PIEDMONT FOR A
SMALL CHANCE OF SPRINKLES ACROSS THE EXTREME NW AND NRN CWA...
MAINLY SUNDAY MORNING. REGARDLESS... THE HIGH-LEVEL LIFT SHOULD
ENSURE AT LEAST PARTLY CLOUDY SKIES FOR MUCH OF THE DAY... IF NOT
OCCASIONALLY MOSTLY CLOUDY. DESPITE THE CLOUDS... THE INCREASING SW
FLOW AHEAD OF THIS TROUGH ON SUNDAY IS LIKELY TO DRAW IN SOME MILDER
AIR WITH THICKNESSES SLIGHTLY ABOVE NORMAL... RESULTING IN WHAT MAY
BE THE WARMEST (RELATIVELY SPEAKING) DAY OF THE NEXT SEVERAL DAYS.
AFTER LOWS OF 29-34... EXPECT HIGHS OF 53-60. AS THE STILL-WEAK BUT
STRENGTHENING SURFACE TROUGH DROPS SOUTHEAST THROUGH NC... SETTLING
WEST-TO-EAST ACROSS SRN NC... WHILE MID LEVEL FLOW SPEEDS UP AHEAD
OF YET ANOTHER WEAK WAVE APPROACHING FROM THE WEST... WE SHOULD SEE
AN INCREASE IN CLOUD COVER SUNDAY NIGHT. THIS SHOULD KEEP LOWS UP IN
THE 34-38 RANGE. -GIH
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 240 PM SATURDAY...
...WINTER WEATHER POSSIBLE ACROSS CENTRAL NC EARLY/MID NEXT WEEK...
THE LATEST 12Z MODEL GUIDANCE CONTINUES TO STRUGGLE IN CAPTURING THE
EVOLUTION OF THE UPPER LEVEL PATTERN ACROSS THE EASTERN CONUS NEXT
WEEK...NO SURPRISE GIVEN THE COMPLEX NATURE OF THE PATTERN IN PLACE
ACROSS NORTH AMERICA AND EASTERN PORTIONS OF THE NORTHERN PACIFIC.
A COLD UPPER LEVEL LOW (I.E. POLAR VORTEX CURRENTLY OVER NUNAVUT)
SINKING S/SE TO HUDSON BAY AND FAR NORTHERN MANITOBA/ONTARIO SUN-WED
WILL ALLOW ARCTIC HIGH PRESSURE TO PLUNGE SOUTH FROM CANADA INTO THE
UPPER MIDWEST ON SUNDAY...THEN EASTWARD INTO THE MID-ATLANTIC ON
MONDAY...PROGRESSING INTO THE CAROLINAS AS A DRY ARCTIC COLD FRONT
LATE MONDAY INTO MONDAY NIGHT. CYCLONIC FLOW ALOFT WILL PERSIST EAST
OF THE ROCKIES MON-SAT...WITH A SERIES OF SMALL AMPLITUDE SHORTWAVES
TRACKING EAST ACROSS THE LOWER 48. THE PRECISE EVOLUTION OF THE
AFOREMENTIONED SHORTWAVE DISTURBANCES IS EXTREMELY DIFFICULT TO
ASCERTAIN AT THIS TIME GIVEN THAT SOME OF THE ENERGY WILL LIKELY
EMANATE FROM A CUT-OFF UPPER LEVEL LOW IN THE PACIFIC (JUST SOUTH OF
THE ALEUTIANS THIS AFTERNOON)...A MATTER FURTHER COMPLICATED BY A
POTENTIAL FOR SOME DEGREE OF PHASING WITH ADDITIONAL SHORTWAVE
ENERGY ROUNDING THE SOUTHERN PERIPHERY OF THE POLAR VORTEX BY
EARLY/MID NEXT WEEK.
DESPITE SIGNIFICANT DIFFERENCES AMONG THE LONG RANGE MODELS...THERE
IS RELATIVELY GOOD AGREEMENT THAT AN ARCTIC AIRMASS WILL ADVECT INTO
CENTRAL NC LATE MON/MON NIGHT...AND THAT A MILLER-A TYPE CYCLONE
SHOULD DEVELOP IN VICINITY OF A STRONG BAROCLINIC ZONE ALONG OR
OFFSHORE THE CAROLINA COAST TUE/WED. HOWEVER...FORECAST SPECIFICS
REMAIN ELUSIVE...AND IT IS DIFFICULT TO SAY MORE THAN 1) CENTRAL NC
SHOULD SEE BELOW NORMAL TEMPERATURES EARLY/MID NEXT WEEK AND 2)
THERE WILL BE A CHANCE FOR WINTRY PRECIPITATION OVER AT LEAST SOME
(IF NOT ALL) OF CENTRAL NC BETWEEN TUE MORNING AND WED NIGHT. IN
SUCH A PATTERN...IT WOULD BE UNWISE TO ACCEPT ANY MODEL SOLUTION AT
FACE VALUE 72+ HRS OUT. SIMILARLY...ANY ASSERTION RELATING TO
PTYPE/ACCUM/IMPACT IS SIMPLY BEYOND THE SCIENCE AT THIS TIME...AND
ANY STATEMENT TO THAT END WOULD BE SPECULATION AT BEST. -VINCENT
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 100 PM SATURDAY...
SHORTWAVE TROUGH OVER THE AREA WILL EXIT THE COAST THIS AFTERNOON.
BKN/OVC VFR CEILINGS BETWEEN 6 TO 15KFT WILL LIKELY SCATTER OUT A
FEW HOURS LATE THIS AFTERNOON AND INTO THE EVENING...WITH AN
INCREASE IN HIGH CLOUDS AFTER MIDNIGHT IN ADVANCE OF YET ANOTHER
FAST MOVING UPPER DISTURBANCE. CANNOT RULE OUT THE POSSIBILITY LOW
CLOUDS/FOG EARLY SUNDAY MORNING AREAWIDE AS A WEAK SURFACE TROUGH
APPROACHES FROM THE WEST. GIVEN LOW CONFIDENCE...WILL NOT
CARRY ANY RESTRICTIONS WITH THIS FORECAST...BUT TRENDS WILL NEED
TO BE MONITORED.
LOOKING BEYOND 18Z SUNDAY MORNING... VFR CONDITIONS ARE LIKELY TO
DOMINATE THROUGH MONDAY WITH A DRY COLD FRONTAL PASSAGE THROUGH THE
AREA SUNDAY NIGHT/EARLY MONDAY. CONFIDENCE DECREASES TENFOLD BEYOND
MONDAY AS A SLOW MOVING FRONTAL ZONE EXTENDING FROM THE GULF OF
MEXICO NEWD TO SOUTHEAST COAST COULD BRING A PROLONGED PERIOD OF
ADVERSE AVIATION CONDITIONS TUE THROUGH THURSDAY...WITH WINTRY MIX
OF RAIN AND SNOW POSSIBLE ACROSS THE FORECAST AREA.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...CBL/HARTFIELD
SHORT TERM...SMITH
LONG TERM...VINCENT
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
100 PM EST SAT FEB 8 2014
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL CROSS THE SOUTHEAST
STATES TODAY... AS SURFACE HIGH PRESSURE OVER THE AREA WEAKENS. A
WEAK LOW PRESSURE TROUGH WILL HOLD OVER THE CAROLINAS TONIGHT
THROUGH SUNDAY NIGHT. A LOW PRESSURE SYSTEM WILL APPROACH FROM THE
WEST EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 930 AM SATURDAY...
TODAY:
SHORTWAVE ENERGY OVER THE SOUTHERN APPALACHIANS/SAVANNA RIVER
VALLEY WILL QUICKLY MOVE ENE AND OFF THE CAROLINA COAST BY MIDDAY.
SATELLITE AND OBSERVATION TRENDS SUPPORT WHAT THE HRRR AND THE WRF-
ARW SHOWED YESTERDAY EVENING...WITH THE PRECIP HUGGING THE COASTAL
SECTIONS OF THE CAROLINAS AND GEORGIA...OWING TO THE CONSIDERABLE
LOW-LEVEL FORCING FROM A COMBINATION OF STRONG LOW-MOISTURE FLUX
CONVERGENCE AND FRONTOGENESIS ASSOCIATED WITH THE OFFSHORE LOW
PRESSURE SYSTEM AND BAROCLINIC FRONTAL ZONE. WITH PRECIP CONFINED
TO THE COASTAL SECTIONS...THERE WILL BE NO P-TYPE ISSUES...WITH ALL
RAIN WITH PRECIP AMOUNTS AROUND A TENTH OF AN INCH OVER
SAMPSON...WAYNE COUNTIES.
BY 18Z...LOW-LEVEL VEERING AROUND TO WESTERLY WILL ADVECT DRIER AIR
INTO THE AREA...ENDING PRECIP CHANCES AS FORCING SHIFTS OFFSHORE
WITH PARTIAL CLEARING SPREADING EASTWARD. HIGHS TODAY IN THE MID 40
TO LOWER 50S...WARMEST SW. -CBL
FOR TONIGHT THROUGH SUNDAY NIGHT: ANOTHER WEAK SHORTWAVE TROUGH (NOW
WELL BACK OVER THE ROCKIES) CROSSES THE AREA LATE TONIGHT INTO
SUNDAY MORNING... ACCOMPANIED BY ANOTHER SURGE IN UPPER DIVERGENCE.
WHILE THE BULK OF THE MOISTURE WITH THIS APPEARS TO ZIP BY QUICKLY
TO OUR NORTH... THERE LOOKS TO BE JUST ENOUGH LOW LEVEL MOISTURE AND
WEAK MASS CONVERGENCE ALONG A DEVELOPING SURFACE TROUGH OVER THE
FOOTHILLS/WRN PIEDMONT FOR A SMALL CHANCE OF SPRINKLES ACROSS THE
EXTREME NW AND NRN CWA... MAINLY SUNDAY MORNING. REGARDLESS... THE
HIGH-LEVEL LIFT SHOULD ENSURE AT LEAST PARTLY CLOUDY SKIES FOR MUCH
OF THE DAY... IF NOT OCCASIONALLY MOSTLY CLOUDY. DESPITE THE
CLOUDS... THE INCREASING SW FLOW AHEAD OF THIS TROUGH ON SUNDAY IS
LIKELY TO DRAW IN SOME MILDER AIR WITH THICKNESSES SLIGHTLY ABOVE
NORMAL... RESULTING IN WHAT MAY BE THE WARMEST (RELATIVELY SPEAKING)
DAY OF THE NEXT SEVERAL DAYS. AFTER LOWS OF 29-34... EXPECT HIGHS OF
53-60. AS THE STILL-WEAK BUT STRENGTHENING SURFACE TROUGH DROPS
SOUTHEAST THROUGH NC... SETTLING WEST-TO-EAST ACROSS SRN NC... WHILE
MID LEVEL FLOW SPEEDS UP AHEAD OF YET ANOTHER WEAK WAVE APPROACHING
FROM THE WEST... WE SHOULD SEE AN INCREASE IN CLOUD COVER SUNDAY
NIGHT. THIS SHOULD KEEP LOWS UP IN THE 34-38 RANGE. -GIH
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...
COLD FRONT/TROUGH MOVING SOUTHEAST THROUGH THE AREA EARLY MONDAY
WILL SETTLE SOUTH ACROSS SC DURING THE DAY. LACKING MUCH UPPER
LEVEL SUPPORT...MODELS ARE IN FAIR AGREEMENT ON A MOSTLY DRY FRONTAL
PASSAGE AND DWINDLING ANAFRONTAL PRECIP EAST OF THE MOUNTAINS. WILL
MAINTAIN A SLIGHT CHANCE POP MONDAY AFTERNOON/EVENING AND ACROSS
SOUTHERN COUNTIES MONDAY NIGHT AS THE FRONT STALLS TO OUR SOUTH AND
MODELS INDICATE THE POTENTIAL FOR MULTIPLE WAVES OF LOW PRESSURE TO
TRACK ON THE BOUNDARY. CLEARING BEHIND THE FRONT SHOULD BE QUICKLY
FILLED BACK IN BY INCREASING SOUTHERN STREAM MOISTURE IN THE MID AND
UPPER LEVELS. COLD ADVECTION...WHILE NOT VERY STRONG
INITIALLY...WILL KEEP HIGHS FROM CLIMBING TO MUCH MORE THAN THE MID
AND UPPER 40S. STRONGER COLD ADVECTION MONDAY NIGHT WILL DROVE LOWS
BACK DOWN INTO THE UPPER 20S AND LOWER 30S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 AM SATURDAY...
THERE REMAINS QUITE A LOT OF UNCERTAINTY REGARDING THE DETAILS OF A
WINTRY MIX OF PRECIP FOR THE MIDDLE OF NEXT WEEK...
BROAD CYCLONIC FLOW ALOFT WILL REMAIN IN PLACE OVER THE EASTERN
US... WITH A SURFACE HIGH FORECAST TO BUILD FROM THE MID WEST TOWARD
THE MID-ATLANTIC AND NEW ENGLAND STATES. MEANWHILE...A SOUTHERN
STREAM...AND CURRENTLY POORLY SAMPLED SHORTWAVE OVER THE PACIFIC
WILL TRAVERSE THE SOUTHERN US AS VARIOUS PIECES OF NORTHERN STREAM
STREAM ENERGY MOVE ACROSS THE MIDWEST STATES. THE MAIN FORECAST
PROBLEM WILL BE TO WHAT...IF ANY...DEGREE THESE WAVES PHASE...AND
THE TRACK OF AN ASSOCIATED SURFACE WAVE ALONG THE STALLED BOUNDARY
TO OUR SOUTH. WPC GUIDANCE CONTINUES TO LEAN AWAY FROM THE
DETERMINISTIC GFS AND ECMWF... AND TOWARD MORE THE SUPPRESSED MILLER
A TYPE SURFACE LOW TRACKS OF THE GEFS AND EC ENSEMBLE MEANS.
CONSIDERING THIS...IT SEEMS THE BEST WAY TO APPROACH THE FORECAST
UNCERTAINTY IS TO FOCUS ON HOW THE SYSTEMS MAY EVOLVE: 1) WITH THE
FRONT TO OUR SOUTH AND THE FLOW INITIALLY LESS AMPLIFIED...MOISTURE
AND POP SHOULD BE GREATEST ACROSS SOUTHERN AREAS TUESDAY/TUESDAY
NIGHT. THERMAL PROFILES WOULD SUPPORT A RAIN/SNOW MIX ACROSS THE
SOUTH AND A BETTER CHANCE OF SNOW TO THE NORTH. 2) AS THE
SOUTHERN STREAM SHORTWAVE BECOMES A PLAYER WEDNESDAY/THURSDAY...AND
IF PHASING/AMPLIFICATION WITH THE NORTHERN STREAM WAVE OCCURS...THEN
A COASTAL LOW SHOULD DEVELOP AND PTYPE WOULD TRANSITION TO A MORE
CLIMATOLOGICALLY FAVORED DISTRIBUTION...WITH A WINTRY MIX MORE
LIKELY OVER THE NORTHWEST PIEDMONT AND RAIN OVER THE COASTAL PLAIN.
THE EXTENT OF WINTRY PRECIP WILL ALSO BE STRONGLY INFLUENCED BY HOW
LONG SURFACE HIGH OVER THE NORTHEAST US HOLDS IN PLACE.
DUE TO THE UNCERTAINTY AND TO KEEP CONSISTENCY WITH THE PREVIOUS
FORECAST...WILL ONLY MAKE MINOR ADJUSTMENTS TO THE FORECAST...MAINLY
TO INTRODUCE A SMALL CHANCE OF RAIN OR SNOW TUESDAY MORNING AND TO
EXPAND THE RAIN/SNOW AREA A BIT. HIGHS WILL BE WELL BELOW NORMAL
THROUGH MOST OF THE WEEK...LIKELY REMAINING BELOW 40 TUESDAY AND
WEDNESDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 1 PM SATURDAY...
SHORTWAVE TROUGH OVER THE AREA WILL EXIT THE COAST THIS AFTERNOON.
BKN/OVC VFR CEILINGS BETWEEN 6 TO 15KFT WILL LIKELY SCATTER OUT A
FEW HOURS LATE THIS AFTERNOON AND INTO THE EVENING...WITH AN
INCREASE IN HIGH CLOUDS AFTER MIDNIGHT IN ADVANCE OF YET ANOTHER
FAST MOVING UPPER DISTURBANCE. CANNOT RULE OUT THE POSSIBILITY LOW
CLOUDS/FOG EARLY SUNDAY MORNING AREAWIDE AS A WEAK SURFACE TROUGH
APPROACHES FROM THE WEST. GIVEN LOW CONFIDENCE...WILL NOT
CARRY ANY RESTRICTIONS WITH THIS FORECAST...BUT TRENDS WILL NEED
TO BE MONITORED.
LOOKING BEYOND 18Z SUNDAY MORNING... VFR CONDITIONS ARE LIKELY TO
DOMINATE THROUGH MONDAY WITH A DRY COLD FRONTAL PASSAGE THROUGH THE
AREA SUNDAY NIGHT/EARLY MONDAY. CONFIDENCE DECREASES TENFOLD BEYOND
MONDAY AS A SLOW MOVING FRONTAL ZONE EXTENDING FROM THE GULF OF
MEXICO NEWD TO SOUTHEAST COAST COULD BRING A PROLONGED PERIOD OF
ADVERSE AVIATION CONDITIONS TUE THROUGH THURSDAY...WITH WINTRY MIX
OF RAIN AND SNOW POSSIBLE ACROSS THE FORECAST AREA.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...CBL/HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1229 PM EST SAT FEB 8 2014
.SYNOPSIS...
LOW PRESSURE WELL OFF THE CAROLINA COAST WILL MOVE TO THE
NORTHEAST...REMAINING WELL OFFSHORE. A BRIEF WARM-UP IS EXPECTED
SUNDAY AHEAD OF A COLD FRONT THAT WILL CROSS THE CAROLINAS EARLY
MONDAY. HIGH PRESSURE WILL RIDGE ACROSS THE AREA MONDAY AND
TUESDAY...AND GIVE WAY TO DEVELOPING LOW PRESSURE FROM THE GULF OF
MEXICO DURING THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM SATURDAY...SUBSIDENCE BEHIND THE SHORTWAVE TROUGH
MOVING ACROSS THE EASTERN CAROLINAS HAS BEEN REMARKABLE AT BORING
STRAIGHT DOWN THROUGH ALL THE MID CLOUDS...LETTING SUNSHINE BREAK
OUT ACROSS CENTRAL SOUTH CAROLINA. I HAVE RAISED HIGHS A BIT ACROSS
THE PEE DEE REGION AS A RESULT AND HAVE SPED UP THE TIMING OF THE
BACK EDGE OF THE PRECIPITATION WHICH IS PUSHING ACROSS CAPE FEAR IN
THE NEXT 30 MINUTES. NEXT ORDER OF BUSINESS WILL BE TO WEIGH THE
POTENTIAL THAT FOG MAY DEVELOP THIS EVENING WITH THE CLEARING SKIES
BUT FAIR AMOUNT OF LOW-LEVEL MOISTURE REMAINING. PREVIOUS DISCUSSION
FROM 930 AM FOLLOWS...
SURFACE LOW PRESSURE ALONG A STALLED COLD FRONT IS LOCATED ABOUT 220
MILES SOUTH OF CAPE FEAR. THIS LOW IS MOVING RAPIDLY NORTHEAST AND
SHOULD REMAIN WELL OFFSHORE TODAY AND TONIGHT. ISENTROPIC LIFT OF
GULF MOISTURE ACROSS THE FRONTAL INVERSION IS PRODUCING LIGHT TO
MODERATE RAINFALL ALL ALONG THE SOUTHEASTERN U.S. FROM THE FLORIDA
PANHANDLE AND GEORGIA ACROSS THE EASTERN CAROLINAS. IT IS A COLD
RAIN WITH TEMPERATURES IN THE UPPER 30S TO LOWER 40S ACROSS THE AREA.
THE 06Z NAM APPEARS TO HAVE THE BEST HANDLE ON THE THERMAL STRUCTURE
AND WINDS WITHIN THE LOWER ATMOSPHERE...ALTHOUGH IT HAD SOME ISSUES
WITH MOISTURE DISTRIBUTION ALOFT WHEN COMPARED TO THE 12Z SOUNDINGS
AT CHS AND MHX. THE LAST SEVERAL RUC AND HRRR RUNS ARE SHOWING
MODERATE TO MAJOR INITIALIZATION ISSUES THAT ARE MAKING THEM
UNUSABLE FOR THIS FORECAST UPDATE. EAST OF I-95 RAIN SHOULD CONTINUE
THROUGH EARLY AFTERNOON WITH A TAPERING OFF TREND EXPECTED BETWEEN
1-3 PM FROM WEST TO EAST. WEST OF I-95 MID-LEVEL MOISTURE IS MUCH
MORE SPORADIC WITH MAINLY LIGHT SPITS OF RAIN OBSERVED SO FAR. THIS
SHOWS UP IN MY QPF GRIDS WHICH RANGE FROM ONLY A COUPLE HUNDREDTHS
OF AN INCH IN DARLINGTON AND BENNETTSVILLE TO JUST OVER ONE-THIRD OF
AN INCH ALONG THE COAST.
I HAVE ADJUSTED FORECAST HIGHS DOWNWARD BY A COUPLE DEGREES ACROSS
COASTAL SE NORTH CAROLINA WHERE RAIN WILL PERSIST LONGEST...WITH
LESSER ADJUSTMENTS MADE ACROSS SOUTH CAROLINA. FORECAST HIGHS RANGE
FROM THE MID 40S IN WILMINGTON...TO THE UPPER 40S ACROSS THE GRAND
STRAND...CONWAY...WHITEVILLE...AND LUMBERTON. ACROSS THE PEE DEE AND
SANTEE RIVER REGION ASSUMING RAIN SHUTS OFF ON SCHEDULE HIGHS COULD
REACH 50-52 BRIEFLY DURING THE LATE AFTERNOON HOURS. BUT AS
LONG AS RAIN CONTINUES TEMPERATURES WILL REMAIN STUCK IN THE UPPER
30S TO LOWER 40S WITH EVAPORATIONAL COOLING BALANCING ANY WEAK
INSOLATION THROUGH THE CLOUDS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...A RAIN-FREE AND SEASONABLE SUNDAY EXPECTED DUE
TO NEARLY ZONAL MID LEVEL FLOW AND A POORLY DEFINED SURFACE PRESSURE
PATTERN. TEMPS GET LOWERED A NOTCH ON MONDAY AS A COLD FRONT PUSHES
THROUGH ALTHOUGH THE TIMING OF THE BOUNDARY IS VERY POORLY AGREED
UPON BETWEEN VARIOUS MODEL GUIDANCE. THE SEEMING OUTLYING WRF EVEN
SHOWS A SLOW ENOUGH FROPA FOR A MILD AFTERNOON. FROPA ITSELF WILL BE
TOO MOISTURE STARVED TO LEAD TO ANY MEANINGFUL RAIN CHANCES. SLIGHT
CHANCE POPS CROP UP TOWARDS THE END OF THE PERIOD AS WARM AIR BEGINS
TO OVERRUN THE POST-FRONTAL SURFACE HIGH.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...CHANCES FOR RAIN INCREASE AS TUESDAY WEARS ON
DUE TO WEAK LOW PRESSURE DEVELOPING ON FRONTAL BOUNDARY WELL OFF THE
COAST. TOUGH TO SAY WHETHER THERE IS A SHORT BREAK TUESDAY NIGHT
BEFORE THE NEXT SYSTEM TAKES SHAPE IN SIMILAR LOCATION. THIS LOOKING
RATHER IMPORTANT AS TEMP PROFILES SEEM SUPPORTIVE OF AT LEAST SOME
WINTRY PTYPE. THE GFS HAS BACKED OFF IN ITS DEPICTION OF THIS SYSTEM
BENEFITING FROM GOMEX MOISTURE WHILE THE ECMWF STILL LOOKS FAIRLY
WET. ALSO FAIRLY NEW IS THE MUCH SLOWER TIMING IN THE GFS SHOWING
THE BEST CHANCE FOR RAIN NOT UNTIL THURSDAY. WILL STICK MORE IN LINE
WITH PREV FCST DUE TO SUPPORT FROM ECMWF BUT SHOW VERY LOW RAIN
CHANCES ON THURSDAY. BEHIND THIS SYSTEM A MODERATING TREND SHOULD
GET UNDERWAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...BACK END OF PRECIP WILL EXIT THE REGION AROUND 19-20Z.
IFR CEILINGS LURKING TO THE SOUTH. WILL INTRODUCE AN INTERMITTENT
MVFR CEILING FOR THE FIRST COUPLE OF HOURS...BUT IT WILL BE NEAR
IFR. THIS EVENING...SKIES MAY SCATTER FROM TIME TO TIME. WITH ALL
THE LOW LEVEL MOISTURE AND LIGHT WINDS...FOG IS A POSSIBILITY EVEN
THOUGH THE MODELS DO NOT SEEM ENTHUSED BY IT. BEST TIME WILL BE
AROUND MIDNIGHT...WITH SOME DRYING AFTER THAT. SUNDAY...AN UPPER
TROUGH WILL SWING THROUGH THE REGION WITH LITTLE IMPACT OTHER THAN A
MID CLOUD CEILING.
EXTENDED OUTLOOK...VFR EXPECTED THROUGH MONDAY AFTERNOON.
DETERIORATING CONDITIONS MONDAY NIGHT WITH MODERATE CONFIDENCE FOR
IFR CONDITIONS IN PRECIP TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM SATURDAY...WINDS ARE PERHAPS COMING DOWN A BIT FASTER
THAN ANTICIPATED. SEAS ARE STILL 4-6 FT AT THE TWO DATA BUOYS WITHIN
OUR WATERS...BUT WITHOUT REASONABLY STRONG WINDS CONTINUING THROUGH
THE AFTERNOON THESE SEAS MAY FLATTEN A LITTLE FASTER THAN
ANTICIPATED. THE SMALL CRAFT ADVISORY REMAINS IN EFFECT BUT MAY BE
DROPPED EARLY IF THIS TREND CONTINUES. 12Z MODELS ARE IN AND SHOULD
HELP ANSWER THIS QUESTION IN THE NEXT 1-2 HOURS. PREVIOUS DISCUSSION
FROM 930 AM FOLLOWS...
LOW PRESSURE IS ANALYZED ABOUT 220 MILES SOUTH OF CAPE FEAR AND
MOVING NORTHEASTWARD ALONG A STALLED COLD FRONT THAT BISECTS
FLORIDA. THE PRESSURE GRADIENT BETWEEN THIS LOW AND HIGH PRESSURE
NOSING DOWN FROM THE NORTH IS PRODUCING NE WINDS 15-25 KT ACROSS THE
CAROLINA COASTAL WATERS CURRENTLY. THE 06Z NAM APPEARS TO HAVE THE
BEST HANDLE ON THE CURRENTLY SITUATION AND IS OUR MODEL OF CHOICE.
THE STRONGEST WINDS ARE EXPECTED TO OCCUR BETWEEN NOW AND 1
PM...WITH WINDS GRADUALLY BACKING MORE NORTHERLY AND DIMINISHING IN
SPEED SLIGHTLY DURING THE MID AND LATE AFTERNOON. RADAR SHOWS A
NEARLY SOLID SHIELD OF RAIN EXTENDING BACK INTO NORTHERN FLORIDA
WHICH WILL TAKE ITS TIME CLEARING THE AREA TODAY. EXPECT
RAIN...OCCASIONALLY MODERATE IN INTENSITY...TO CONTINUE THROUGH THE
DAY. SEAS CURRENTLY RANGE FROM 6 FEET OUT AT THE FRYING PAN SHOALS
BUOY TO 4 FEET AT THE CAPE FEAR HARBOR BUOY SOUTH OF SOUTHPORT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...WIND BECOMES LIGHT ON SUNDAY AS PRESSURE
GRADIENT BECOMES QUITE WEAK ACROSS THE SOUTHEASTERN U.S. AN
APPROACHING COLD FRONT WILL LEAD TO A PRONOUNCED OFFSHORE FLOW
DIRECTION AS THE DAY WEARS ON WITH A POSSIBLE BACKING FROM NW TO SW.
LATE DAY/SUNDAY NIGHT ALSO SHOULD BRING A 5KT OR SO INC IN SPEEDS.
SEAS TO BUILD BUT ONLY ABOUT A FT AND AWAY FROM SHORE IN THE
COAST-PARALLEL FLOW. SHARP VEER TO N ON MONDAY AS COLD FRONT MOVES
THROUGH RATHER QUICKLY. ADD ANOTHER FT TO SEAS BUT STILL FALLING SHY
OF HEADLINES. HIGH BUILDS IN FROM THE NW ON MONDAY NIGHT CAUSING A
TURN TO THE NE.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...NE TO E WINDS ON TUESDAY TO STRENGTHEN AS HIGH
PRESSURE FINALLY BUILDS INTO NORTHEAST AND MID ATLANTIC. FLAT WAVE
OF LOW PRESSURE TO HOLD THE GRADIENT CLOSE TO THE COAST AND TIGHTEN
IT JUST ENOUGH TO MARGINAL SMALL CRAFT ADVISORY FOR WIND AND SEAS
FOR AT LEAST PART OF THE AREA. ANOTHER WAVE MAY TAKE A SIMILAR
TRACK ON WEDNESDAY LEADING TO FAIRLY UNCHANGED MARINE ENVIRONMENT
AND ADVISORY STILL SEEMS POSSIBLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 7 PM EST SATURDAY FOR
AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1202 AM EST SAT FEB 8 2014
.SYNOPSIS...
LOW PRESSURE WELL OFF THE CAROLINA COAST WILL MOVE TO THE
NORTHEAST...REMAINING WELL OFFSHORE. A BRIEF WARM-UP IS EXPECTED
SUNDAY AHEAD OF A COLD FRONT THAT WILL CROSS THE CAROLINAS EARLY
MONDAY. HIGH PRESSURE WILL RIDGE ACROSS THE AREA MONDAY AND
TUESDAY...AND GIVE WAY TO DEVELOPING LOW PRESSURE FROM THE GULF OF
MEXICO DURING THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...SURFACE LOW PRESSURE ALONG A STALLED COLD
FRONT IS LOCATED ABOUT 220 MILES SOUTH OF CAPE FEAR. THIS LOW IS
MOVING RAPIDLY NORTHEAST AND SHOULD REMAIN WELL OFFSHORE TODAY AND
TONIGHT. ISENTROPIC LIFT OF GULF MOISTURE ACROSS THE FRONTAL
INVERSION IS PRODUCING LIGHT TO MODERATE RAINFALL ALL ALONG THE
SOUTHEASTERN U.S. FROM THE FLORIDA PANHANDLE AND GEORGIA ACROSS THE
EASTERN CAROLINAS. IT IS A COLD RAIN WITH TEMPERATURES IN THE UPPER
30S TO LOWER 40S ACROSS THE AREA.
THE 06Z NAM APPEARS TO HAVE THE BEST HANDLE ON THE THERMAL STRUCTURE
AND WINDS WITHIN THE LOWER ATMOSPHERE...ALTHOUGH IT HAD SOME ISSUES
WITH MOISTURE DISTRIBUTION ALOFT WHEN COMPARED TO THE 12Z SOUNDINGS
AT CHS AND MHX. THE LAST SEVERAL RUC AND HRRR RUNS ARE SHOWING
MODERATE TO MAJOR INITIALIZATION ISSUES THAT ARE MAKING THEM
UNUSABLE FOR THIS FORECAST UPDATE. EAST OF I-95 RAIN SHOULD CONTINUE
THROUGH EARLY AFTERNOON WITH A TAPERING OFF TREND EXPECTED BETWEEN
1-3 PM FROM WEST TO EAST. WEST OF I-95 MID-LEVEL MOISTURE IS MUCH
MORE SPORADIC WITH MAINLY LIGHT SPITS OF RAIN OBSERVED SO FAR. THIS
SHOWS UP IN MY QPF GRIDS WHICH RANGE FROM ONLY A COUPLE HUNDREDTHS
OF AN INCH IN DARLINGTON AND BENNETTSVILLE TO JUST OVER ONE-THIRD OF
AN INCH ALONG THE COAST.
I HAVE ADJUSTED FORECAST HIGHS DOWNWARD BY A COUPLE DEGREES ACROSS
COASTAL SE NORTH CAROLINA WHERE RAIN WILL PERSIST LONGEST...WITH
LESSER ADJUSTMENTS MADE ACROSS SOUTH CAROLINA. FORECAST HIGHS RANGE
FROM THE MID 40S IN WILMINGTON...TO THE UPPER 40S ACROSS THE GRAND
STRAND...CONWAY...WHITEVILLE...AND LUMBERTON. ACROSS THE PEE DEE AND
SANTEE RIVER REGION ASSUMING RAIN SHUTS OFF ON SCHEDULE HIGHS COULD
REACH 50-52 BRIEFLY DURING THE LATE AFTERNOON HOURS. BUT AS
LONG AS RAIN CONTINUES TEMPERATURES WILL REMAIN STUCK IN THE UPPER
30S TO LOWER 40S WITH EVAPORATIONAL COOLING BALANCING ANY WEAK
INSOLATION THROUGH THE CLOUDS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...A RAIN-FREE AND SEASONABLE SUNDAY EXPECTED DUE
TO NEARLY ZONAL MID LEVEL FLOW AND A POORLY DEFINED SURFACE PRESSURE
PATTERN. TEMPS GET LOWERED A NOTCH ON MONDAY AS A COLD FRONT PUSHES
THROUGH ALTHOUGH THE TIMING OF THE BOUNDARY IS VERY POORLY AGREED
UPON BETWEEN VARIOUS MODEL GUIDANCE. THE SEEMING OUTLYING WRF EVEN
SHOWS A SLOW ENOUGH FROPA FOR A MILD AFTERNOON. FROPA ITSELF WILL BE
TOO MOISTURE STARVED TO LEAD TO ANY MEANINGFUL RAIN CHANCES. SLIGHT
CHANCE POPS CROP UP TOWARDS THE END OF THE PERIOD AS WARM AIR BEGINS
TO OVERRUN THE POST-FRONTAL SURFACE HIGH.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...CHANCES FOR RAIN INCREASE AS TUESDAY WEARS ON
DUE TO WEAK LOW PRESSURE DEVELOPING ON FRONTAL BOUNDARY WELL OFF THE
COAST. TOUGH TO SAY WHETHER THERE IS A SHORT BREAK TUESDAY NIGHT
BEFORE THE NEXT SYSTEM TAKES SHAPE IN SIMILAR LOCATION. THIS LOOKING
RATHER IMPORTANT AS TEMP PROFILES SEEM SUPPORTIVE OF AT LEAST SOME
WINTRY PTYPE. THE GFS HAS BACKED OFF IN ITS DEPICTION OF THIS SYSTEM
BENEFITING FROM GOMEX MOISTURE WHILE THE ECMWF STILL LOOKS FAIRLY
WET. ALSO FAIRLY NEW IS THE MUCH SLOWER TIMING IN THE GFS SHOWING
THE BEST CHANCE FOR RAIN NOT UNTIL THURSDAY. WILL STICK MORE IN LINE
WITH PREV FCST DUE TO SUPPORT FROM ECMWF BUT SHOW VERY LOW RAIN
CHANCES ON THURSDAY. BEHIND THIS SYSTEM A MODERATING TREND SHOULD
GET UNDERWAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...BACK END OF PRECIP WILL EXIT THE REGION AROUND 19-20Z.
IFR CEILINGS LURKING TO THE SOUTH. WILL INTRODUCE AN INTERMITTENT
MVFR CEILING FOR THE FIRST COUPLE OF HOURS...BUT IT WILL BE NEAR
IFR. THIS EVENING...SKIES MAY SCATTER FROM TIME TO TIME. WITH ALL
THE LOW LEVEL MOISTURE AND LIGHT WINDS...FOG IS A POSSIBILITY EVEN
THOUGH THE MODELS DO NOT SEEM ENTHUSED BY IT. BEST TIME WILL BE
AROUND MIDNIGHT...WITH SOME DRYING AFTER THAT. SUNDAY...AN UPPER
TROUGH WILL SWING THROUGH THE REGION WITH LITTLE IMPACT OTHER THAN A
MID CLOUD CEILING.
EXTENDED OUTLOOK...VFR EXPECTED THROUGH MONDAY AFTERNOON.
DETERIORATING CONDITIONS MONDAY NIGHT WITH MODERATE CONFIDENCE FOR
IFR CONDITIONS IN PRECIP TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...LOW PRESSURE IS ANALYZED ABOUT 220 MILES
SOUTH OF CAPE FEAR AND MOVING NORTHEASTWARD ALONG A STALLED COLD
FRONT THAT BISECTS FLORIDA. THE PRESSURE GRADIENT BETWEEN THIS LOW
AND HIGH PRESSURE NOSING DOWN FROM THE NORTH IS PRODUCING NE WINDS
15-25 KT ACROSS THE CAROLINA COASTAL WATERS CURRENTLY. THE 06Z NAM
APPEARS TO HAVE THE BEST HANDLE ON THE CURRENTLY SITUATION AND IS
OUR MODEL OF CHOICE.
THE STRONGEST WINDS ARE EXPECTED TO OCCUR BETWEEN NOW AND 1
PM...WITH WINDS GRADUALLY BACKING MORE NORTHERLY AND DIMINISHING IN
SPEED SLIGHTLY DURING THE MID AND LATE AFTERNOON. RADAR SHOWS A
NEARLY SOLID SHIELD OF RAIN EXTENDING BACK INTO NORTHERN FLORIDA
WHICH WILL TAKE ITS TIME CLEARING THE AREA TODAY. EXPECT
RAIN...OCCASIONALLY MODERATE IN INTENSITY...TO CONTINUE THROUGH THE
DAY. SEAS CURRENTLY RANGE FROM 6 FEET OUT AT THE FRYING PAN SHOALS
BUOY TO 4 FEET AT THE CAPE FEAR HARBOR BUOY SOUTH OF SOUTHPORT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...WIND BECOMES LIGHT ON SUNDAY AS PRESSURE
GRADIENT BECOMES QUITE WEAK ACROSS THE SOUTHEASTERN U.S. AN
APPROACHING COLD FRONT WILL LEAD TO A PRONOUNCED OFFSHORE FLOW
DIRECTION AS THE DAY WEARS ON WITH A POSSIBLE BACKING FROM NW TO SW.
LATE DAY/SUNDAY NIGHT ALSO SHOULD BRING A 5KT OR SO INC IN SPEEDS.
SEAS TO BUILD BUT ONLY ABOUT A FT AND AWAY FROM SHORE IN THE
COAST-PARALLEL FLOW. SHARP VEER TO N ON MONDAY AS COLD FRONT MOVES
THROUGH RATHER QUICKLY. ADD ANOTHER FT TO SEAS BUT STILL FALLING SHY
OF HEADLINES. HIGH BUILDS IN FROM THE NW ON MONDAY NIGHT CAUSING A
TURN TO THE NE.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...NE TO E WINDS ON TUESDAY TO STRENGTHEN AS HIGH
PRESSURE FINALLY BUILDS INTO NORTHEAST AND MID ATLANTIC. FLAT WAVE
OF LOW PRESSURE TO HOLD THE GRADIENT CLOSE TO THE COAST AND TIGHTEN
IT JUST ENOUGH TO MARGINAL SMALL CRAFT ADVISORY FOR WIND AND SEAS
FOR AT LEAST PART OF THE AREA. ANOTHER WAVE MAY TAKE A SIMILAR
TRACK ON WEDNESDAY LEADING TO FAIRLY UNCHANGED MARINE ENVIRONMENT
AND ADVISORY STILL SEEMS POSSIBLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 7 PM EST SATURDAY FOR
AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1250 PM CST SAT FEB 8 2014
.UPDATE...
ISSUED AT 1250 PM CST SAT FEB 8 2014
FORECAST IN THE SHORT TERM REMAINS ON TRACK. SKY COVER THE
TRICKIEST TO FORECAST FOR THIS AFTERNOON...BUT SHOULD GENERALLY
SEE PARTLY TO MOSTLY CLOUDY FAR WEST AND NORTH...WITH INCREASING
CLOUDS NORTH LATER ON TODAY...DECREASING CLOUDS SOUTHEAST...AND
PARTLY TO MOSTLY SUNNY CENTRAL IN BETWEEN MID LEVEL WAVES. ALSO
ADDED FLURRIES FAR SOUTHWEST BASED ON BOWMAN RADAR AND BAKER MT
REPORTING LIGHT SNOW.
UPDATE
ISSUED AT 1010 AM CST SAT FEB 8 2014
MID LEVEL S/WV MOVING THROUGH OVER THE NEXT 12-18 HOURS WILL
GENERATE MAINLY AN INCREASE IN SKY COVER AS WE PROGRESS THROUGH
TODAY AND INTO TONIGHT. WILL MAINTAIN A MENTION OF ISOLATED
FLURRIES THIS AFTERNOON ACROSS THE FAR NORTH WHERE INCREASING LOW
LEVEL LAPSE RATES ALONG TO BEHIND A SFC COLD FRONT MAY SUPPORT
SOME LIGHT ACTIVITY.
MAIN ADJUSTMENTS WITH THIS UPDATE WERE TO TWEAK DAYTIME HIGHS
BASED ON LATEST OBS AND NEAR TERM MODEL GUIDANCE...AND INCREASE
NIGHTTIME LOWS TONIGHT BY A FEW DEGREES BASED ON LATEST 12Z MODELS
NOW COMING INTO OUR SYSTEMS. FEEL THE INCREASED SKY COVER TONIGHT
WILL PREVENT TEMPERATURES SOUTH CENTRAL AND SOUTHEAST FROM
DROPPING AS EARLIER THOUGHT. STILL ON TRACK WITH THE INHERITED
LOWS WEST AND NORTH WHERE LESS CLOUD COVER IS STILL FORECAST.
STRONG SFC HIGH PRESSURE WILL CLEAR CLOUDS OUT FOR SUNDAY...BUT
STILL COLD WITH HIGHS 5 ABOVE TO 5 BELOW MOST LOCATIONS ACROSS
WEST AND CENTRAL NORTH DAKOTA.
UPDATE ISSUED AT 649 AM CST SAT FEB 8 2014
THE GOING FORECAST IS IN GOOD SHAPE AND ONLY MADE MINOR
ADJUSTMENTS TO CAPTURE THE LATEST TEMPERATURE TRENDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CST SAT FEB 8 2014
THE MAIN FOCUS FOR THE SHORT TERM IS ONCE AGAIN TEMPERATURES.
CLOUD COVER WILL PLAY A BIG ROLE WITH RESPECT TO TEMPERATURES
TODAY. THE LATEST GUIDANCE BUMPS UP HIGH TEMPERATURES 5 TO 10
DEGREES ABOVE THE PREVIOUS FORECAST. IF SKIES CLEAR OUT OVER
SOUTHERN NORTH DAKOTA THESE HIGHER TEMPERATURES COULD BE REALIZED.
HOWEVER...IF CLOUDY SKIES PREVAIL THE LOWER GUIDANCE/PREVIOUS
FORECAST WILL LIKELY VERIFY. THE MAIN COLD AIR ADVECTION SURGE
SHOULD HOLD OFF UNTIL LATE AFTERNOON. THEREFORE...I THINK THE
THICKEST CLOUD COVER WILL REMAIN NORTH MOST OF THE DAY. FOR THIS
REASON I WENT WITH THE SLIGHTLY WARMER HIGH TEMPERATURES ACROSS
THE SOUTH.
WITH THE COLD AIR ADVECTION SURGE THE 07 UTC RAP BRINGS IN SOME
LOWER CLOUDS AND LOW LEVEL MOISTURE DURING THE EVENING ACROSS THE
NORTH.SNOW FLURRIES AND EVEN A BRIEF SNOW SHOWER AREN`T OUT OF THE
QUESTION FOR THE NORTHERN COUNTIES SATURDAY EVENING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 350 AM CST SAT FEB 8 2014
THE START OF THE LONG TERM PERIOD WILL FEATURE NORTHWESTERLY FLOW
AT H5 WITH HIGH PRESSURE IN CONTROL AT THE SURFACE. TEMPERATURES
WILL BE COLD...AND COULD SEE THE EVENTUAL NEED FOR A WIND CHILL
ADVISORY. THIS IS ESPECIALLY TRUE SUNDAY NIGHT ACROSS THE NORTH
AND EAST WHERE WIND CHILLS VALUES COULD FALL INTO THE 20S AND 30S
BELOW ZERO.
WEST / NORTHWEST FLOW WILL DOMINATE THROUGH MOST OF NEXT WEEK. THIS
WILL ALLOW A SERIES OF FAST MOVING CLIPPERS TO MAKE THEIR WAY ACROSS
THE DAKOTAS...BRINGING PERIODIC CHANCES OF PRECIPITATION / SNOW. IT
APPEARS THERE IS GENERAL AGREEMENT BETWEEN THE GFS / ECMWF THAT A
SYSTEM TOWARDS THE MIDDLE OF THE WEEK COULD BE THE STRONGEST OF THE
CLIPPERS.
TEMPERATURES WILL SHOW QUITE A BIT OF VARIABILITY AS THE EXTENDED
PROGRESSES WITH PERIODS OF MODERATING TEMPERATURES...FOLLOWED BY
COOLER TEMPERATURES BEHIND THE WAVES. GENERALLY ACCEPTED THE
ALL-BLEND MODEL CONSENSUS REGARDING TEMPERATURES WHICH SHOULD HELP
MITIGATE SOME OF THE POTENTIAL TIMING DIFFICULTIES OF THE WAVES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1250 PM CST SAT FEB 8 2014
LOW PRESSURE WILL BRING CLOUDS AND LOWER CEILINGS INTO NORTH
DAKOTA THROUGH THE TAF PERIOD. THOUGH THE TIMING IS
UNCERTAIN...EACH TAF SITE MAY HAVE A PERIOD OF MVFR CONDITIONS
THROUGH THE EVENING AND OVERNIGHT...BEFORE CLEARING FROM WEST TO
EAST SUNDAY DAYTIME.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...AJ
LONG TERM...CK
AVIATION...AC/NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1009 AM CST SAT FEB 8 2014
.UPDATE...
ISSUED AT 1010 AM CST SAT FEB 8 2014
MID LEVEL S/WV MOVING THROUGH OVER THE NEXT 12-18 HOURS WILL
GENERATE MAINLY AN INCREASE IN SKY COVER AS WE PROGRESS THROUGH
TODAY AND INTO TONIGHT. WILL MAINTAIN A MENTION OF ISOLATED
FLURRIES THIS AFTERNOON ACROSS THE FAR NORTH WHERE INCREASING LOW
LEVEL LAPSE RATES ALONG TO BEHIND A SFC COLD FRONT MAY SUPPORT
SOME LIGHT ACTIVITY.
MAIN ADJUSTMENTS WITH THIS UPDATE WERE TO TWEAK DAYTIME HIGHS
BASED ON LATEST OBS AND NEAR TERM MODEL GUIDANCE...AND INCREASE
NIGHTTIME LOWS TONIGHT BY A FEW DEGREES BASED ON LATEST 12Z MODELS
NOW COMING INTO OUR SYSTEMS. FEEL THE INCREASED SKY COVER TONIGHT
WILL PREVENT TEMPERATURES SOUTH CENTRAL AND SOUTHEAST FROM
DROPPING AS EARLIER THOUGHT. STILL ON TRACK WITH THE INHERITED
LOWS WEST AND NORTH WHERE LESS CLOUD COVER IS STILL FORECAST.
STRONG SFC HIGH PRESSURE WILL CLEAR CLOUDS OUT FOR SUNDAY...BUT
STILL COLD WITH HIGHS 5 ABOVE TO 5 BELOW MOST LOCATIONS ACROSS
WEST AND CENTRAL NORTH DAKOTA.
UPDATE ISSUED AT 649 AM CST SAT FEB 8 2014
THE GOING FORECAST IS IN GOOD SHAPE AND ONLY MADE MINOR
ADJUSTMENTS TO CAPTURE THE LATEST TEMPERATURE TRENDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CST SAT FEB 8 2014
THE MAIN FOCUS FOR THE SHORT TERM IS ONCE AGAIN TEMPERATURES.
CLOUD COVER WILL PLAY A BIG ROLE WITH RESPECT TO TEMPERATURES
TODAY. THE LATEST GUIDANCE BUMPS UP HIGH TEMPERATURES 5 TO 10
DEGREES ABOVE THE PREVIOUS FORECAST. IF SKIES CLEAR OUT OVER
SOUTHERN NORTH DAKOTA THESE HIGHER TEMPERATURES COULD BE REALIZED.
HOWEVER...IF CLOUDY SKIES PREVAIL THE LOWER GUIDANCE/PREVIOUS
FORECAST WILL LIKELY VERIFY. THE MAIN COLD AIR ADVECTION SURGE
SHOULD HOLD OFF UNTIL LATE AFTERNOON. THEREFORE...I THINK THE
THICKEST CLOUD COVER WILL REMAIN NORTH MOST OF THE DAY. FOR THIS
REASON I WENT WITH THE SLIGHTLY WARMER HIGH TEMPERATURES ACROSS
THE SOUTH.
WITH THE COLD AIR ADVECTION SURGE THE 07 UTC RAP BRINGS IN SOME
LOWER CLOUDS AND LOW LEVEL MOISTURE DURING THE EVENING ACROSS THE
NORTH.SNOW FLURRIES AND EVEN A BRIEF SNOW SHOWER AREN`T OUT OF THE
QUESTION FOR THE NORTHERN COUNTIES SATURDAY EVENING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 350 AM CST SAT FEB 8 2014
THE START OF THE LONG TERM PERIOD WILL FEATURE NORTHWESTERLY FLOW
AT H5 WITH HIGH PRESSURE IN CONTROL AT THE SURFACE. TEMPERATURES
WILL BE COLD...AND COULD SEE THE EVENTUAL NEED FOR A WIND CHILL
ADVISORY. THIS IS ESPECIALLY TRUE SUNDAY NIGHT ACROSS THE NORTH
AND EAST WHERE WIND CHILLS VALUES COULD FALL INTO THE 20S AND 30S
BELOW ZERO.
WEST / NORTHWEST FLOW WILL DOMINATE THROUGH MOST OF NEXT WEEK. THIS
WILL ALLOW A SERIES OF FAST MOVING CLIPPERS TO MAKE THEIR WAY ACROSS
THE DAKOTAS...BRINGING PERIODIC CHANCES OF PRECIPITATION / SNOW. IT
APPEARS THERE IS GENERAL AGREEMENT BETWEEN THE GFS / ECMWF THAT A
SYSTEM TOWARDS THE MIDDLE OF THE WEEK COULD BE THE STRONGEST OF THE
CLIPPERS.
TEMPERATURES WILL SHOW QUITE A BIT OF VARIABILITY AS THE EXTENDED
PROGRESSES WITH PERIODS OF MODERATING TEMPERATURES...FOLLOWED BY
COOLER TEMPERATURES BEHIND THE WAVES. GENERALLY ACCEPTED THE
ALL-BLEND MODEL CONSENSUS REGARDING TEMPERATURES WHICH SHOULD HELP
MITIGATE SOME OF THE POTENTIAL TIMING DIFFICULTIES OF THE WAVES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 649 AM CST SAT FEB 8 2014
MVFR CEILINGS IN EASTERN MONTANA HAVE ONLY MADE SLOW PROGRESS INTO
WESTERN NORTH DAKOTA THIS MORNING. WILL CARRY A CEILING AROUND 3KFT
AT KISN AND KMOT STARTING THIS AFTERNOON...BUT KEEP THE OTHER
TERMINALS VFR. WIND SPEEDS SHOULD GENERALLY STAY 10 KTS OR LESS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...AJ
LONG TERM...CK
AVIATION...CK
AREA FORECAST DISCUSSION
NWS NORMAN OK
1152 AM CST SAT FEB 8 2014
.DISCUSSION...
THE 18Z AVIATION DISCUSSION FOLLOWS....
&&
.AVIATION...
WIDESPREAD BR...FG...AND VERY LOW CEILINGS COVER MOST OF OK AND
SOME PARTS OF N TX AT NOON TODAY. CLEARING FROM W AND SW TX HAS
BEEN EXTREMELY SLOW IN ITS PROGRESS TOWARD THE E AND N. AT THIS
TIME...IT APPEARS THAT KGAG AND KSPS MAY SEE TEMPORARY CLEARING
THIS AFTERNOON AND EARLY EVENING...BUT ALL SITES WILL LIKELY GO
BACK TO IFR/LIFR CONDITIONS OVERNIGHT AS THE FOG AND LOW CLOUDS
FILL BACK IN TO AREAS THAT MANAGE TO CLEAR OUT TODAY. A COLD
FRONT WILL MOVE S ACROSS THE REGION TOMORROW...BRINGING GRADUAL
IMPROVEMENT THROUGH THE DAY TOMORROW.
&&
.PREV DISCUSSION... /ISSUED 1104 AM CST SAT FEB 8 2014/
UPDATE...
ADJUSTED TEMPS... FZFG CONTINUES...
DISCUSSION...
ACTIVE MORNING AS 2 TO 3SM FZFG WILL CONTINUE THROUGH NOON...
WITH VISIBILITIES IMPROVING SLIGHTLY THROUGH THE AFTERNOON.
MOIST...SERLY UPSLOPE FLOW CONTINUES TO FUNNEL ACROSS THE
REGION... THE MOST SEVERE FZFG OCCURRED EARLY THIS MORNING ACROSS
THE TX PANHANDLE AND FAR WRN N TX ALONG THE ERN EDGE OF THE TX
ESCARPMENT. KOUN 12Z SOUNDING SAMPLED A VERY SHALLOW COLD LAYER AT
THE SURFACE WITH A STEEP INVERSION STARTING NEAR 920MB. LATEST
SOLUTION FROM THE RAP IS SLOW TO WARM THE SFC/CUT AWAY AT THE
INVERSION... PER BUFKIT... WHICH COLLABORATES WELL WITH CURRENT
THOUGHTS. MORNING RUNS OF THE H-TRIP ARE ON BOARD AS WELL...
KEEPING PRETTY MUCH ALL OF OK/WRN N TX SOCKED IN WITH LOW STRATUS
THROUGH THE DAY. WITH CLOUDS HANGING ON... THIS IS GOING TO WREAK
HAVOC WITH TEMPS TODAY. CURRENTLY BROUGHT DOWN HIGHS QUITE A FEW
DEGREES FOR MOST LOCATIONS... ESPECIALLY ACROSS NRN OK.
WILL KEEP A CLOSE EYE ON THE NUISANCE FZFG AND TEMPS... MAKING
ADJUSTMENTS AS NEED.
JTK
PREV DISCUSSION... /ISSUED 611 AM CST SAT FEB 8 2014/
AVIATION...
LIFR CEILINGS WILL GRADUALLY RISE BY MID-DAY AND DISSIPATE THIS
AFTERNOON IN WESTERN OKLAHOMA. FOG WILL RESTRICT VISIBILITY FROM
AS LOW AS 1/2 MILE THIS MORNING. AFTER 090600 FOG IS LIKELY TO THE
SOUTH AND WEST OF OKLAHOMA CITY UNTIL A COLD FRONT MOVES THROUGH
NORTHERN OKLAHOMA BEFORE 091200.
PREV DISCUSSION... /ISSUED 447 AM CST SAT FEB 8 2014/
DISCUSSION...
LIGHT FOG SHOULD SLOWLY DISSIPATE THIS MORNING, BUT THE SUN WILL
BE SLOW IN COMING UNTIL AFTERNOON. TEMPERATURES WILL THEN RISE
ABOVE THOSE OF THE LAST WEEK FROM THE MIDDLE 30S IN NORTH CENTRAL
OKLAHOMA TO MORE THAN 50 IN AREAS SOUTHWEST OF WICHITA FALLS.
MODERATE TEMPERATURES WILL BE SHORT LIVED WHEN THE ARRIVAL OF THE
NEXT COLD FRONT SUNDAY BRINGS A COLDER AIRMASS- BUT NOT AS COLD AS
THE ONE EARLIER THIS WEEK. THROUGH TUESDAY TEMPERATURES WILL BE
NEAR OR SLIGHTLY BELOW FREEZING IN THE DAYTIME. AN UPPER LEVEL
WAVE, WHICH IS FORECAST TO MOVE THROUGH THE LONG WAVE RIDGE OVER
THE WEST COAST, WILL APPROACH OKLAHOMA LATE SUNDAY. LIGHT SNOW IS
POSSIBLE MAINLY OVER AREAS EAST OF I-35 WHERE GREATER MOISTURE
WILL BE. MONDAY AND EARLY TUESDAY COULD BRING SEVERAL INCHES OF
SNOW TO THE NORTH AND EAST OF OKLAHOMA CITY. IN THE WAKE OF THIS
WAVE, THE MEAN FLOW GAINS MUCH MORE OF A DOWNSLOPE COMPONENT AND
TEMPERATURES WILL CLIMB TO NORMALS AND EVEN ABOVE FOR THE SECOND
HALF OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 36 25 32 19 / 0 0 10 20
HOBART OK 37 26 30 19 / 0 0 10 10
WICHITA FALLS TX 42 30 40 22 / 0 10 10 0
GAGE OK 34 16 23 13 / 0 0 20 30
PONCA CITY OK 34 20 26 15 / 0 0 20 30
DURANT OK 43 25 43 28 / 0 0 10 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
04/23/23
AREA FORECAST DISCUSSION
NWS NORMAN OK
1104 AM CST SAT FEB 8 2014
.UPDATE...
ADJUSTED TEMPS... FZFG CONTINUES...
&&
.DISCUSSION...
ACTIVE MORNING AS 2 TO 3SM FZFG WILL CONTINUE THROUGH NOON...
WITH VISIBILITIES IMPROVING SLIGHTLY THROUGH THE AFTERNOON.
MOIST...SERLY UPSLOPE FLOW CONTINUES TO FUNNEL ACROSS THE
REGION... THE MOST SEVERE FZFG OCCURRED EARLY THIS MORNING ACROSS
THE TX PANHANDLE AND FAR WRN N TX ALONG THE ERN EDGE OF THE TX
ESCARPMENT. KOUN 12Z SOUNDING SAMPLED A VERY SHALLOW COLD LAYER AT
THE SURFACE WITH A STEEP INVERSION STARTING NEAR 920MB. LATEST
SOLUTION FROM THE RAP IS SLOW TO WARM THE SFC/CUT AWAY AT THE
INVERSION... PER BUFKIT... WHICH COLLABORATES WELL WITH CURRENT
THOUGHTS. MORNING RUNS OF THE H-TRIP ARE ON BOARD AS WELL...
KEEPING PRETTY MUCH ALL OF OK/WRN N TX SOCKED IN WITH LOW STRATUS
THROUGH THE DAY. WITH CLOUDS HANGING ON... THIS IS GOING TO WREAK
HAVOC WITH TEMPS TODAY. CURRENTLY BROUGHT DOWN HIGHS QUITE A FEW
DEGREES FOR MOST LOCATIONS... ESPECIALLY ACROSS NRN OK.
WILL KEEP A CLOSE EYE ON THE NUISANCE FZFG AND TEMPS... MAKING
ADJUSTMENTS AS NEED.
JTK
&&
.PREV DISCUSSION... /ISSUED 611 AM CST SAT FEB 8 2014/
AVIATION...
LIFR CEILINGS WILL GRADUALLY RISE BY MID-DAY AND DISSIPATE THIS
AFTERNOON IN WESTERN OKLAHOMA. FOG WILL RESTRICT VISIBILITY FROM
AS LOW AS 1/2 MILE THIS MORNING. AFTER 090600 FOG IS LIKELY TO THE
SOUTH AND WEST OF OKLAHOMA CITY UNTIL A COLD FRONT MOVES THROUGH
NORTHERN OKLAHOMA BEFORE 091200.
PREV DISCUSSION... /ISSUED 447 AM CST SAT FEB 8 2014/
DISCUSSION...
LIGHT FOG SHOULD SLOWLY DISSIPATE THIS MORNING, BUT THE SUN WILL
BE SLOW IN COMING UNTIL AFTERNOON. TEMPERATURES WILL THEN RISE
ABOVE THOSE OF THE LAST WEEK FROM THE MIDDLE 30S IN NORTH CENTRAL
OKLAHOMA TO MORE THAN 50 IN AREAS SOUTHWEST OF WICHITA FALLS.
MODERATE TEMPERATURES WILL BE SHORT LIVED WHEN THE ARRIVAL OF THE
NEXT COLD FRONT SUNDAY BRINGS A COLDER AIRMASS- BUT NOT AS COLD AS
THE ONE EARLIER THIS WEEK. THROUGH TUESDAY TEMPERATURES WILL BE
NEAR OR SLIGHTLY BELOW FREEZING IN THE DAYTIME. AN UPPER LEVEL
WAVE, WHICH IS FORECAST TO MOVE THROUGH THE LONG WAVE RIDGE OVER
THE WEST COAST, WILL APPROACH OKLAHOMA LATE SUNDAY. LIGHT SNOW IS
POSSIBLE MAINLY OVER AREAS EAST OF I-35 WHERE GREATER MOISTURE
WILL BE. MONDAY AND EARLY TUESDAY COULD BRING SEVERAL INCHES OF
SNOW TO THE NORTH AND EAST OF OKLAHOMA CITY. IN THE WAKE OF THIS
WAVE, THE MEAN FLOW GAINS MUCH MORE OF A DOWNSLOPE COMPONENT AND
TEMPERATURES WILL CLIMB TO NORMALS AND EVEN ABOVE FOR THE SECOND
HALF OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 36 25 32 19 / 0 0 10 20
HOBART OK 37 26 30 19 / 0 0 10 10
WICHITA FALLS TX 42 30 40 22 / 0 10 10 0
GAGE OK 34 16 23 13 / 0 0 20 30
PONCA CITY OK 34 20 26 15 / 0 0 20 30
DURANT OK 43 25 43 28 / 0 0 10 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
1020 AM PST SAT FEB 8 2014
.SYNOPSIS...THE THIRD SYSTEM IN A ONE-TWO-THREE PUNCH OF WINTRY
WEATHER WILL IMPACT NORTHWEST OREGON AND PORTIONS OF SOUTHWEST
WASHINGTON TODAY AND TONIGHT. LOW PRESSURE DEVELOPING OFF THE
SOUTHERN OREGON COAST WILL PUSH MORE MOISTURE INTO THE REGION...AND
TEMPERATURES ARE STILL GENERALLY BELOW FREEZING WITH THE EXCEPTIONS
BEING THE COAST AND HIGHER TERRAIN OF LANE COUNTY. SLIGHTLY WARMER
AIR ALOFT WILL LEAD TO A MAJOR ICE STORM FOR SOME INTERIOR VALLEYS
SALEM SOUTHWARD AND POSSIBLY A BIT FARTHER NORTH. ENOUGH COLD AIR
REMAINS ENTRENCHED FOR MOST PRECIPITATION TO FALL AS SNOW NORTH OF A
SALEM TO TILLAMOOK LINE. THIS SYSTEM WILL CLEAR OUT SUNDAY MORNING
WITH JUST SOME LINGERING RAIN AND SNOW SHOWERS FOR SUNDAY. GRADUALLY
MILDER AIR MOVES IN BY MONDAY...BUT NOT BEFORE MORE POTENTIAL ICING
IN THE COLUMBIA GORGE. ONSHORE FLOW AND A CONSOLIDATED PACIFIC JET
WILL BRING A RETURN TO MORE TYPICAL PERIODS OF VALLEY RAIN AND
MOUNTAIN SNOW AS THE WEEK PROGRESSES.
&&
.UPDATE...HEAVY SNOW WILL CONTINUE TO SPREAD NORTH WITH RATES OF 1-2
INCHES PER HOUR AND NEAR WHITEOUT CONDITIONS AT TIMES THROUGH THIS
THE REST OF THE MORNING. SEE NOWPQR. HAVE ENDED THE WINTER WX
ADVISORIES THAT WERE IN EFFECT FOR FZDZ. HEAVY SNOW AGAIN STARTING A
BIT AHEAD OF SCHEDULE. ROADS WILL BECOME TREACHEROUS VERY QUICKLY
FROM THIS POINT FORWARD.
ALSO CHANGED THE CENTRAL VALLEY AND THE NORTH OREGON CASCADE
FOOTHILLS. TO AN ICE STORM WARNING. WHILE THERE
WILL BE CONTINUED SNOW TODAY...FREEZING RAIN WILL DOMINATE LATER IN
THE AFTERNOON...ESPECIALLY SALEM SOUTHWARD. FIGURED THIS WAS THE
HIGHER THREAT EVEN THOUGH POINTS NORTH MAY JUST MIX WITH FZRA LATER
TODAY. THIS IS ALL SEMANTICS AND WAS IN THE WORDING OF THE WSW
EARLIER...BUT WANTED TO BRING ATTENTION TO THIS SIGNIFICANT THREAT
FOR PARTS OF THIS AREA ESPECIALLY AS THE DAY GOES ON. WILL STILL
MENTION THE INITIAL SNOW IN THE PRODUCT.
REST OF THE UPDATE UNCHANGED...THE NAM BUFR AND RAP SOUNDINGS WOULD
SUGGEST THE DOMINANT PRECIPITATION TYPE IN THE CENTRAL VALLEY WILL
LIKELY TURN BACK TO FZRA AFTER SNOW THIS MORNING. 12Z SLE SOUNDING
SHOWS THE WARM NOSE CENTERED AROUND 900 MB WITH A TEMPERATURE OF 33F
AT THIS LEVEL. SOUNDINGS SUGGEST THIS ONLY GETS WARMER THROUGH THE
DAY. IF YOU FOLLOW RAP 925 MB TEMPERATURES WHICH HAVE A REASONABLE
GRASP ON THE LOCATION OF THE WARM NOSE...THIS PUSHES THROUGH THE
CENTRAL VALLEY AND EVEN NORTH THROUGH THE PORTLAND METRO AREA. THE
BIG QUESTION IS WHAT SURFACE TEMPERATURES DO. IF YOU BELIEVE MOS AND
RAP...SURFACE TEMPERATURES WILL WARM ABOVE FREEZING THROUGH THE
CENTRAL VALLEY. WITH A NORTH GRADIENT FEEDING THE LOWER LEVEL COLD
AIR FEEL THIS ISOVERDONE.
AM CONSIDERING CONVERTING THE CENTRAL VALLEY AND THE NORTH OREGON
FOOTHILLS TO AN ICE STORM WARNING. THERE IS A PRETTY HEAVY BAND OF
SNOWFALL THAT THE MODELS ARE IN REALLY GOOD AGREEMENT SETTING UP OVER
PORTLAND LATER THIS AFTERNOON AND EVENING. NAM BUFR SOUNDINGS KEEP
THE PORTLAND AREA ALL SNOW OR A MIX OF SLEET AND SNOW...BUT IT IS
CERTAINLY REASONABLE THAT THE SOUTH METRO AREA COULD GET IN ON THE
FREEZING RAIN. THIS COULD MAKE FOR A DISASTROUS SITUATION FOR THE
METRO AREA. CURRENTLY FEEL THAT ICE ACCUMULATIONS WILL BE LIMITED
THIS FAR NORTH INITIALLY DUE TO SNOW AND SLEET WITH THE REINFORCING
FEED OF COLD AIR COMING.
WHERE THE UNCERTAINTY COMES INTO PLAY BUT CONFIRMS FEELINGS IN THE
LAST SENTENCE IS THE WELL PERFORMING ECMWF OF THE LAST FEW DAYS KEEP
THINGS ALL SNOW THROUGH THE BULK OF THE EVENT NORTH OF SALEM AND
WITH THE COLD AIR GETTING REPLENISHED AS THE OFFSHORE LOW ARRIVES AND
STRENGTHENS THE OFFSHORE PRESSURE GRADIENT...WITH THE WARM NOSE NOT
PUSHING THROUGH THE NORTH UNTIL AFTER HEAVIEST PRECIPITATION PUSHES
THROUGH...THEN TRANSITIONS TO A SLEET FREEZING RAIN MIX TOMORROW
MORNING IN LIGHTER PRECIPITATION. .
THOSE OF YOU CONSIDERING TRAVEL TODAY SHOULD RECONSIDER IF IT ALL
POSSIBLE ...AS THERE IS ALREADY SIGNIFICANT ICING AS FAR NORTH AS
ALBANY...AND IT IS LIKELY THIS AREA WILL CONTINUE TO SPREAD
NORTH...ESPECIALLY LATER THIS AFTERNOON AND ESPECIALLY THIS EVENING.
EITHER WAY FOR POINTS NORTH THERE WILL BE ANOTHER SLUG OF MODERATE
TO HEAVY PRECIPITATION LATER THIS AFTERNOON AND EVENING.
EITHER WAY...MOST MODELS SUGGEST A MIX OF LIGHTER PRECIPITATION ON
SUNDAY. STILL ROADS WILL BE MESSY. POINTS FARTHER SOUTH WILL BEGIN
TO FINALLY THAW AND REMAIN RAIN.
/KMD
&&
.SHORT TERM...THE SHORT TERM DISCUSSION FOCUSES ON THE SYSTEM TO
IMPACT THE FORECAST AREA TODAY THROUGH SUNDAY...AS THIS WILL BE THE
BIG SHOW IN TOWN. A MAJOR RE-SHUFFLING OF WATCHES WARNINGS AND
ADVISORIES WAS DONE FOR THE MORNING PACKAGE...HENCE THE VERY LATE
DISCUSSION ONCE AGAIN. APOLOGIES FOR THAT.
TODAY THROUGH EARLY SUNDAY WILL FEATURE A HIGH-IMPACT...MULTI FACETED
WINTER STORM WHICH WILL AFFECT NORTHWEST OREGON AND PARTS OF
SOUTHWEST WASHINGTON WITH HEAVY SNOW...ICE...AND EVEN WIND NEAR THE
COLUMBIA GORGE. AREAS FROM THE PORTLAND/VANCOUVER METRO NORTHWARD
WILL SEE MAINLY SNOW...AND IT WILL BE HEAVY FOR A PERIOD THIS
AFTERNOON AND EVENING. AREAS FROM SALEM SOUTHWARD WILL SEE PRIMARILY
FREEZING RAIN WITH MAJOR ICE ACCUMULATIONS LIKELY IN SOME LOCATIONS.
SNOW LEVELS WILL RISE ACROSS THE SOUTHERN HALF OF OUR FORECAST AREA
FAIRLY RAPIDLY...SO THE LINN/LANE COUNTY CASCADES MAY SEE A QUICK
CHANGE TO RAIN AND VALLEY FREEZING RAIN AFTER A BRIEF PERIOD OF SNOW.
CASCADES NORTH OF SANTIAM PASS WILL SEE MORE IN THE WAY OF
SNOW...WITH UP TO A FOOT NEAR MOUNT HOOD.
THIS DISCUSSION WOULD GROW AS LARGE AS A NOVEL IF I WERE TO EXPLAIN
ALL THE METEOROLOGICAL REASONING BEHIND THESE DECISIONS. BELOW I WILL
FOCUS ON THE RATIONALE BEHIND WHAT WE CONSIDER THE MOST DANGEROUS
THREATS TO AFFECT THE AREA. THE MOST CONCERNING ISSUE WITH THIS
INCOMING SYSTEM WILL BE THE HEAVY ICE POTENTIAL FOR THE LOWLANDS...
PARTICULARLY THE CENTRAL AND SOUTH WILLAMETTE VALLEY.
INFRARED SATELLITE IMAGERY SHOWS A DEEPENING LOW PRESSURE SYSTEM NEAR
42N/132W...HEADING E-NE TOWARD THE OREGON COAST. THIS SYSTEM IS
STRONGER THAN THE LOW PRESSURE SYSTEMS THAT BROUGHT WIDESPREAD SNOW
TO THE REGION THURSDAY AND FRIDAY. AS A RESULT...WARM ADVECTION OUT
AHEAD OF THIS SYSTEM IS STRONGER THAN IT WAS WITH THE PREVIOUS TWO
SYSTEMS...PARTICULARLY BETWEEN 950-800 MB. MODEL SOUNDINGS SHOW GOOD
AGREEMENT THAT THIS WILL PUSH A WARM NOSE OF ABOVE FREEZING AIR WELL
NORTH INTO THE WILLAMETTE VALLEY...AND IN FACT THAT IS ALREADY
HAPPENING WITH -FZRA BEING REPORTED AT EUGENE. THIS SYSTEM HAS A
DECENT SUBTROPICAL TAP THAT EXTENDS SW TOWARD HAWAII...WHICH WILL
FEED PLENTY OF MOISTURE OVER THE LOW-LEVEL COLD AIR.
THE LOW-LEVEL COLD AIR IS BEING LOCKED IN BY INCREASING EASTERLY
PRESSURE GRADIENTS AND A DEEP COLD POOL EAST OF THE CASCADES. AS LOW
PRESSURE APPROACHES FROM THE SW...NORTHERLY PRESSURE GRADIENTS ARE
ALSO INCREASING UP THE WILLAMETTE VALLEY. THIS SHOULD KEEP THE ENTIRE
WILLAMETTE VALLEY BELOW FREEZING FOR A MAJORITY OF THE EVENT...WHILE
LOCALLY 0.35-0.75 INCH OF QPF FALL OVER MUCH OF NORTHWEST OREGON.
WITH SOME CONDITIONAL INSTABILITY...THERE WILL LIKELY BE SOME HEAVIER
BANDS WHICH MAY CONTRIBUTE TO QPF LOCALLY OVER ONE INCH. 00Z
ECMWF/UKMET...06Z NAM/GFS...ALL SHOW SOME FORM OF THIS OCCURRING.
SOUTH OF SALEM...WHERE PRECIPITATION WILL BE ALMOST ALL FREEZING
RAIN...NEARLY ALL OF THIS AMOUNT WILL FREEZE ON TREES... POWER
LINES...AND ROADS WHICH WILL MAKE FOR A VERY DANGEROUS SITUATION. AS
A RESULT...WE OPTED FOR AN ICE STORM WARNING FOR OUR SOUTHERN VALLEYS
TO HIGHLIGHT THIS THREAT. AREAS SALEM SOUTHWARD CAN EXPECT NUMEROUS
POWER OUTAGES TODAY AND TONIGHT...WHICH MAY TAKE SOME TIME TO RECOVER
FROM.
FARTHER NORTH...IN THE PORTLAND/VANCOUVER METRO...THE WARM NOSE WILL
HAVE A MORE DIFFICULT TIME WORKING ITS WAY TO THE COLUMN. THIS DUE TO
THE DEPTH OF THE COLD POOL EAST OF THE CASCADES...FILTERING COLD AIR
WESTWARD THROUGH THE GAPS AND PASSES. THE RELATIVELY LOWER TERRAIN
BETWEEN MOUNT ADAMS AND MOUNT HOOD WILL ALLOW THIS COLD AIR TO PUSH
FREELY WESTWARD INTO THE PDX/VUO METRO. IF THERE IS ANY QUESTION AS
TO THE MAGNITUDE OF THIS COLD AIR...IT IS ONLY 10 DEGREES AT
GOVERNMENT CAMP. BASED ON REPORTS NEAR THE CASCADE CREST IT APPEARS
THIS COLD POOL IS ABOUT 5000 FEET DEEP.
SINCE THE COLD AIR WILL BE STUBBORN IN THE PDX/VUO METRO...EXPECT
MOST PRECIPITATION TO FALL AS SNOW. BASED ON THE QPF EXPECT GENERAL
4-8 INCH TOTALS WHERE PCPN REMAINS SNOW...LIGHTER AMOUNTS NORTH OF
CLARK COUNTY. DEPENDING ON WHERE THE ABOVE-MENTIONED CSI BANDING SETS
UP...SOME SPOTS IN THE METRO AREA COULD SEE A FOOT OF NEW SNOW. THE
BEST CHANCE FOR THIS WILL BE WESTERN WASHINGTON AND YAMHILL COUNTY
WHERE EASTERLY FLOW OFTEN GETS A LITTLE OROGRAPHIC BOOST.
THERE ARE STILL SOME UNCERTAINTIES. IF THE EASTSIDE COLD POOL AND
ASSOCIATED COLD ADVECTION DOES NOT REMAIN AS DEEP THROUGH THE
CASCADES...THERE IS A CHANCE ENOUGH OF THE COLUMN MAY WARM ENOUGH TO
CHANGE PRECIPITATION TO SLEET IN THE PDX/VUO METRO THIS AFTERNOON AND
TONIGHT. THIS WOULD CONSIDERABLY CUT DOWN THE SNOW ACCUMULATION
POTENTIAL. THE BEST CHANCE FOR THIS TO HAPPEN IN THE NORTH WILLAMETTE
VALLEY WILL BE IN CLACKAMAS COUNTY...BUT IT IS POSSIBLE THROUGHOUT
THE PDX/VUO METRO AREA.
ALSO THERE IS A CHANCE THAT THE LOW OFFSHORE COULD CONTINUE TO
RAPIDLY INTENSIFY...PUSHING UP THE COAST AND DRAGGING WITH IT MORE
LOW-LEVEL SOUTHERLY FLOW IF IT MOVES ONSHORE. THIS WOULD CHANGE
EUGENE TO RAIN EARLY AND CONSIDERABLY CUT BACK ON THEIR ICE
ACCUMULATIONS...POTENTIALLY PUTTING THE PDX/VUO METRO IN THE
CROSSHAIRS FOR A MAJOR ICE EVENT. THIS APPEARS UNLIKELY...AS THE MAIN
BAROCLINIC ZONE REMAINS NEAR THE LANE/DOUGLAS COUNTY LINE...AND THIS
IS OFTEN WHERE LOWS TEND TO TRACK. MORE LIKELY THE LOW WILL APPROACH
THE COAST AND OCCLUDE AS IT ENCOUNTERS THE STRONG COLD POOL
ENTRENCHED OVER NW OREGON.
THE UPPER ENERGY MOVES ACROSS THE CASCADES EARLY SUN MORNING AND
PRECIP WILL TAPER TO SHOWERS THEREAFTER. IT IS LIKELY TEMPERATURES
WILL MODERATE JUST A BIT SUNDAY...POTENTIALLY ENOUGH TO START THAWING
OUT SOME AREAS THAT GET HIT HARD BY SNOW AND ICE TODAY AND TONIGHT.
BUCKLE YOUR SEAT BELTS FOLKS...ITS GOING TO BE AN INTERESTING RIDE
TODAY AND TONIGHT. WEAGLE
.MEDIUM AND LONG TERM...MONDAY THROUGH FRIDAY...MOST ALL AREAS WILL
BE MILDER BY MON AM...WITH TEMPERATURES ABOVE FREEZING.
HOWEVER...WITH COLD AIR STILL LOCKED IN THE COLUMBIA BASIN...WILL
STILL HAVE COLD AIR BLEEDING INTO THE GORGE. WILL KEEP AREAS OF
FREEZING RAIN IN THE GORGE AND UPPER HOOD RIVER VALLEY DURING THE
MORNING. BY AFTERNOON...MILDER AIR WILL FINALLY REACH THOSE
AREAS...WITH GRADUAL WARM UP.
MODELS ALL INDICATE A MUCH MORE PROGRESSIVE PATTERN OVER THE REGION
FOR NEXT WEEK. THIS WILL BRING RAIN...WITH SNOW CONFINED TO THE
HIGHER CASCADES. SYSTEM PASSING ACROSS REGION TUE NIGHT/WED WITH
ANOTHER STRONG FRONT ON THU. THESE WILL BRING FAIRLY DECENT ROUND OF
RAIN. SNOW LEVELS 5K FT ON TUE/TUE NIGHT...THEN SETTLE AROUND 3500
TO 4500 FT. LOOKS GOOD FOR BUILDING CASCADES SNOWPACK. ROCKEY.
&&
.AVIATION...A MIX OF FLIGHT CONDITIONS THIS MORNING...PRIMARILY
MVFR TO LOW-END VFR AT THE TAF SITES. EXPECT CONDITIONS TO LOWER
INTO IFR THROUGHOUT MUCH OF THE REGION AFTER 18Z...STARTING IN THE
SOUTH AND SPREADING NORTH THROUGH THE EARLY AFTERNOON. PRECIP TYPE
WILL BE A CHALLENGE. HIGH CONFIDENCE IN -FZRA IN THE CENTRAL AND
SOUTH WILLAMETTE VALLEY...AND OREGON CASCADE FOOTHILLS THROUGH 06Z
SUN. NORTH WILLAMETTE VALLEY AND SW WA LIKELY TO BE IFR IN SNOW
THROUGH 06Z SUN. PRECIP DIMINISHES AFTER 06Z...BUT STILL EXPECT
WIDESPREAD IFR TO MVFR. ELEVATED TERRAIN WILL BE OBSCURED AND
ICING WILL BECOME MORE OF A SIGNIFICANT FLIGHT ISSUE THROUGH THE
FORECAST PERIOD.
KPDX AND APPROACHES...VFR AS OF 16Z BUT WILL NOT LAST MUCH LONGER.
NEXT ROUND OF PRECIP SHOULD REACH THE TERMINAL AROUND 18Z.
CONDITIONS TO DROP INTO IFR IN SNOW. PRECIP TO REMAIN AS SNOW
THROUGH AT LEAST 03Z SUN...AND POSSIBLY AS LONG AS 06Z.
ADDITIONAL ACCUMULATIONS OF 2 TO 6 INCHES POSSIBLE BEFORE CHANGING
TO -FZRA. LOOKS LIKE MORE -FZRA AND SLEET THREAT FOR THE TERMINAL
AFTER 06Z SUN...BUT FORTUNATELY PRECIP WILL BE DIMINISHING. IFR TO
LOW-END MVFR TO PREVAIL AFTER 06Z SUN. WEISHAAR
&&
.MARINE...EAST OFFSHORE WIND CONTINUES THIS MORNING. STILL GETTING
GUSTS 25 TO 30 KT AT BUOY 029. BASED ON LATEST MODEL GUIDANCE WILL
EXTEND THE SMALL CRAFT ADVISORY FOR WIND IN THE NORTH WATERS
THROUGH 22Z. GFS WOULD SUGGEST POSSIBLE 20-25 KT S-SW WIND ACROSS
THE FAR SRN WATERS LATE TODAY. NAM AND ECMWF MAINTAIN EAST WIND
AND HAVE TRENDED TOWARD THOSE SOLUTIONS. THE WIND IS EXPECTED TO
INCREASE BACK INTO SMALL CRAFT RANGE THROUGHOUT THE COASTAL WATERS
SUN NIGHT AND MON. A STRONGER SYSTEM TUE NIGHT AND WED COULD
PRODUCE GALES.
SEAS RUNNING A COUPLE FEET HIGHER THAN GUIDANCE THIS MORNING. NRN
BUOYS AT 7-8 FT...DESPITE THE EAST WIND. HAVE NUDGED SEAS UP A
FOOT OR SO TODAY AND TONIGHT. SEAS TO REMAIN BELOW 10 FT THROUGH
MON NIGHT. SWELL THROUGH MON NIGHT WILL BE DOMINATED BY A SHORT
PERIOD FRESH SWELL FROM THE S TO SW. SEAS MAY APPROACH MID TEENS
WITH THE STRONGER SYSTEM TUE AND TUE NIGHT. WEISHAAR
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER STORM WARNING UNTIL 4 AM PST SUNDAY FOR GREATER PORTLAND
METRO AREA-NORTHERN OREGON CASCADES-UPPER HOOD RIVER VALLEY.
WINTER STORM WARNING UNTIL 4 AM PST SUNDAY FOR CENTRAL
COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.
WINTER STORM WARNING UNTIL 4 AM PST SUNDAY FOR CASCADES IN LANE
COUNTY-COAST RANGE OF NORTHWEST OREGON
ICE STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CASCADE
FOOTHILLS IN LANE COUNTY-SOUTH WILLAMETTE VALLEY.
ICE STORM WARNING UNTIL 4 AM PST FOR CENTRAL WILLAMETTE VALLEY-
NORTH OREGON CASCADE FOOTHILLS.
WINTER WEATHER ADVISORY UNTIL 4 AM PST SUNDAY FOR LOWER
COLUMBIA.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CENTRAL
COAST RANGE OF WESTERN OREGON.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR NORTH
OREGON COAST.
WA...WINTER STORM WARNING UNTIL 4 AM PST SUNDAY FOR GREATER
VANCOUVER AREA.
WINTER WEATHER ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR
CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 4 AM PST
SUNDAY FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER
GORGE.
WINTER WEATHER ADVISORY UNTIL 4 AM PST SUNDAY FOR I-5 CORRIDOR
IN COWLITZ COUNTY-SOUTH WASHINGTON CASCADE FOOTHILLS.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 2 PM PST THIS AFTERNOON
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD
OR OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
846 AM PST SAT FEB 8 2014
.SYNOPSIS...THE THIRD SYSTEM IN A ONE-TWO-THREE PUNCH OF WINTRY
WEATHER WILL IMPACT NORTHWEST OREGON AND PORTIONS OF SOUTHWEST
WASHINGTON TODAY AND TONIGHT. LOW PRESSURE DEVELOPING OFF THE
SOUTHERN OREGON COAST WILL PUSH MORE MOISTURE INTO THE REGION...AND
TEMPERATURES ARE STILL GENERALLY BELOW FREEZING WITH THE EXCEPTIONS
BEING THE COAST AND HIGHER TERRAIN OF LANE COUNTY. SLIGHTLY WARMER
AIR ALOFT WILL LEAD TO A MAJOR ICE STORM FOR SOME INTERIOR VALLEYS
SALEM SOUTHWARD AND POSSIBLY A BIT FARTHER NORTH. ENOUGH COLD AIR
REMAINS ENTRENCHED FOR MOST PRECIPITATION TO FALL AS SNOW NORTH OF A
SALEM TO TILLAMOOK LINE. THIS SYSTEM WILL CLEAR OUT SUNDAY MORNING
WITH JUST SOME LINGERING RAIN AND SNOW SHOWERS FOR SUNDAY. GRADUALLY
MILDER AIR MOVES IN BY MONDAY...BUT NOT BEFORE MORE POTENTIAL ICING
IN THE COLUMBIA GORGE. ONSHORE FLOW AND A CONSOLIDATED PACIFIC JET
WILL BRING A RETURN TO MORE TYPICAL PERIODS OF VALLEY RAIN AND
MOUNTAIN SNOW AS THE WEEK PROGRESSES.
&&
.UPDATE...THE NAM BUFR AND RAP SOUNDINGS WOULD SUGGEST THE DOMINANT
PRECIPITATION TYPE IN THE CENTRAL VALLEY WILL LIKELY TURN BACK TO
FZRA AFTER SNOW THIS MORNING. 12Z SLE SOUNDING SHOWS THE WARM NOSE
CENTERED AROUND 900 MB WITH A TEMPERATURE OF 33F AT THIS LEVEL.
SOUNDINGS SUGGEST THIS ONLY GETS WARMER THROUGH THE DAY. IF YOU
FOLLOW RAP 925 MB TEMPERATURES WHICH HAVE A REASONABLE GRASP ON THE
LOCATION OF THE WARM NOSE...THIS PUSHES THROUGH THE CENTRAL VALLEY
AND EVEN NORTH THROUGH THE PORTLAND METRO AREA. THE BIG QUESTION IS
WHAT SURFACE TEMPERATURES DO. IF YOU BELIEVE MOS AND RAP...SURFACE
TEMPERATURES WILL WARM ABOVE FREEZING THROUGH THE CENTRAL VALLEY.
WITH A NORTH GRADIENT FEEDING THE LOWER LEVEL COLD AIR FEEL THIS IS
OVERDONE.
AM CONSIDERING CONVERTING THE CENTRAL VALLEY AND THE NORTH OREGON
FOOTHILLS TO AN ICE STORM WARNING. THERE IS A PRETTY HEAVY BAND OF
SNOWFALL THAT THE MODELS ARE IN REALLY GOOD AGREEMENT SETTING UP OVER
PORTLAND LATER THIS AFTERNOON AND EVENING. NAM BUFR SOUNDINGS KEEP
THE PORTLAND AREA ALL SNOW OR A MIX OF SLEET AND SNOW...BUT IT IS
CERTAINLY REASONABLE THAT THE SOUTH METRO AREA COULD GET IN ON THE
FREEZING RAIN. THIS COULD MAKE FOR A DISASTROUS SITUATION FOR THE
METRO AREA. CURRENTLY FEEL THAT ICE ACCUMULATIONS WILL BE LIMITED
THIS FAR NORTH INITIALLY DUE TO SNOW AND SLEET WITH THE REINFORCING
FEED OF COLD AIR COMING.
WHERE THE UNCERTAINTY COMES INTO PLAY BUT CONFIRMS FEELINGS IN THE
LAST SENTENCE IS THE WELL PERFORMING ECMWF OF THE LAST FEW DAYS KEEP
THINGS ALL SNOW THROUGH THE BULK OF THE EVENT NORTH OF SALEM AND
WITH THE COLD AIR GETTING REPLENISHED AS THE OFFSHORE LOW ARRIVES AND
STRENGTHENS THE OFFSHORE PRESSURE GRADIENT...WITH THE WARM NOSE NOT
PUSHING THROUGH THE NORTH UNTIL AFTER HEAVIEST PRECIPITATION PUSHES
THROUGH...THEN TRANSITIONS TO A SLEET FREEZING RAIN MIX TOMORROW
MORNING IN LIGHTER PRECIPITATION. .
THOSE OF YOU CONSIDERING TRAVEL TODAY SHOULD RECONSIDER IF IT ALL
POSSIBLE ...AS THERE IS ALREADY SIGNIFICANT ICING AS FAR NORTH AS
ALBANY...AND IT IS LIKELY THIS AREA WILL CONTINUE TO SPREAD
NORTH...ESPECIALLY LATER THIS AFTERNOON AND ESPECIALLY THIS EVENING.
EITHER WAY FOR POINTS NORTH THERE WILL BE ANOTHER SLUG OF MODERATE
TO HEAVY PRECIPITATION LATER THIS AFTERNOON AND EVENING.
EITHER WAY...MOST MODELS SUGGEST A MIX OF LIGHTER PRECIPITATION ON
SUNDAY. STILL ROADS WILL BE MESSY. POINTS FARTHER SOUTH WILL BEGIN
TO FINALLY THAW AND REMAIN RAIN.
/KMD
&&
.SHORT TERM...THE SHORT TERM DISCUSSION FOCUSES ON THE SYSTEM TO
IMPACT THE FORECAST AREA TODAY THROUGH SUNDAY...AS THIS WILL BE THE
BIG SHOW IN TOWN. A MAJOR RE-SHUFFLING OF WATCHES WARNINGS AND
ADVISORIES WAS DONE FOR THE MORNING PACKAGE...HENCE THE VERY LATE
DISCUSSION ONCE AGAIN. APOLOGIES FOR THAT.
TODAY THROUGH EARLY SUNDAY WILL FEATURE A HIGH-IMPACT...MULTI FACETED
WINTER STORM WHICH WILL AFFECT NORTHWEST OREGON AND PARTS OF
SOUTHWEST WASHINGTON WITH HEAVY SNOW...ICE...AND EVEN WIND NEAR THE
COLUMBIA GORGE. AREAS FROM THE PORTLAND/VANCOUVER METRO NORTHWARD
WILL SEE MAINLY SNOW...AND IT WILL BE HEAVY FOR A PERIOD THIS
AFTERNOON AND EVENING. AREAS FROM SALEM SOUTHWARD WILL SEE PRIMARILY
FREEZING RAIN WITH MAJOR ICE ACCUMULATIONS LIKELY IN SOME LOCATIONS.
SNOW LEVELS WILL RISE ACROSS THE SOUTHERN HALF OF OUR FORECAST AREA
FAIRLY RAPIDLY...SO THE LINN/LANE COUNTY CASCADES MAY SEE A QUICK
CHANGE TO RAIN AND VALLEY FREEZING RAIN AFTER A BRIEF PERIOD OF SNOW.
CASCADES NORTH OF SANTIAM PASS WILL SEE MORE IN THE WAY OF
SNOW...WITH UP TO A FOOT NEAR MOUNT HOOD.
THIS DISCUSSION WOULD GROW AS LARGE AS A NOVEL IF I WERE TO EXPLAIN
ALL THE METEOROLOGICAL REASONING BEHIND THESE DECISIONS. BELOW I WILL
FOCUS ON THE RATIONALE BEHIND WHAT WE CONSIDER THE MOST DANGEROUS
THREATS TO AFFECT THE AREA. THE MOST CONCERNING ISSUE WITH THIS
INCOMING SYSTEM WILL BE THE HEAVY ICE POTENTIAL FOR THE LOWLANDS...
PARTICULARLY THE CENTRAL AND SOUTH WILLAMETTE VALLEY.
INFRARED SATELLITE IMAGERY SHOWS A DEEPENING LOW PRESSURE SYSTEM NEAR
42N/132W...HEADING E-NE TOWARD THE OREGON COAST. THIS SYSTEM IS
STRONGER THAN THE LOW PRESSURE SYSTEMS THAT BROUGHT WIDESPREAD SNOW
TO THE REGION THURSDAY AND FRIDAY. AS A RESULT...WARM ADVECTION OUT
AHEAD OF THIS SYSTEM IS STRONGER THAN IT WAS WITH THE PREVIOUS TWO
SYSTEMS...PARTICULARLY BETWEEN 950-800 MB. MODEL SOUNDINGS SHOW GOOD
AGREEMENT THAT THIS WILL PUSH A WARM NOSE OF ABOVE FREEZING AIR WELL
NORTH INTO THE WILLAMETTE VALLEY...AND IN FACT THAT IS ALREADY
HAPPENING WITH -FZRA BEING REPORTED AT EUGENE. THIS SYSTEM HAS A
DECENT SUBTROPICAL TAP THAT EXTENDS SW TOWARD HAWAII...WHICH WILL
FEED PLENTY OF MOISTURE OVER THE LOW-LEVEL COLD AIR.
THE LOW-LEVEL COLD AIR IS BEING LOCKED IN BY INCREASING EASTERLY
PRESSURE GRADIENTS AND A DEEP COLD POOL EAST OF THE CASCADES. AS LOW
PRESSURE APPROACHES FROM THE SW...NORTHERLY PRESSURE GRADIENTS ARE
ALSO INCREASING UP THE WILLAMETTE VALLEY. THIS SHOULD KEEP THE ENTIRE
WILLAMETTE VALLEY BELOW FREEZING FOR A MAJORITY OF THE EVENT...WHILE
LOCALLY 0.35-0.75 INCH OF QPF FALL OVER MUCH OF NORTHWEST OREGON.
WITH SOME CONDITIONAL INSTABILITY...THERE WILL LIKELY BE SOME HEAVIER
BANDS WHICH MAY CONTRIBUTE TO QPF LOCALLY OVER ONE INCH. 00Z
ECMWF/UKMET...06Z NAM/GFS...ALL SHOW SOME FORM OF THIS OCCURRING.
SOUTH OF SALEM...WHERE PRECIPITATION WILL BE ALMOST ALL FREEZING
RAIN...NEARLY ALL OF THIS AMOUNT WILL FREEZE ON TREES... POWER
LINES...AND ROADS WHICH WILL MAKE FOR A VERY DANGEROUS SITUATION. AS
A RESULT...WE OPTED FOR AN ICE STORM WARNING FOR OUR SOUTHERN VALLEYS
TO HIGHLIGHT THIS THREAT. AREAS SALEM SOUTHWARD CAN EXPECT NUMEROUS
POWER OUTAGES TODAY AND TONIGHT...WHICH MAY TAKE SOME TIME TO RECOVER
FROM.
FARTHER NORTH...IN THE PORTLAND/VANCOUVER METRO...THE WARM NOSE WILL
HAVE A MORE DIFFICULT TIME WORKING ITS WAY TO THE COLUMN. THIS DUE TO
THE DEPTH OF THE COLD POOL EAST OF THE CASCADES...FILTERING COLD AIR
WESTWARD THROUGH THE GAPS AND PASSES. THE RELATIVELY LOWER TERRAIN
BETWEEN MOUNT ADAMS AND MOUNT HOOD WILL ALLOW THIS COLD AIR TO PUSH
FREELY WESTWARD INTO THE PDX/VUO METRO. IF THERE IS ANY QUESTION AS
TO THE MAGNITUDE OF THIS COLD AIR...IT IS ONLY 10 DEGREES AT
GOVERNMENT CAMP. BASED ON REPORTS NEAR THE CASCADE CREST IT APPEARS
THIS COLD POOL IS ABOUT 5000 FEET DEEP.
SINCE THE COLD AIR WILL BE STUBBORN IN THE PDX/VUO METRO...EXPECT
MOST PRECIPITATION TO FALL AS SNOW. BASED ON THE QPF EXPECT GENERAL
4-8 INCH TOTALS WHERE PCPN REMAINS SNOW...LIGHTER AMOUNTS NORTH OF
CLARK COUNTY. DEPENDING ON WHERE THE ABOVE-MENTIONED CSI BANDING SETS
UP...SOME SPOTS IN THE METRO AREA COULD SEE A FOOT OF NEW SNOW. THE
BEST CHANCE FOR THIS WILL BE WESTERN WASHINGTON AND YAMHILL COUNTY
WHERE EASTERLY FLOW OFTEN GETS A LITTLE OROGRAPHIC BOOST.
THERE ARE STILL SOME UNCERTAINTIES. IF THE EASTSIDE COLD POOL AND
ASSOCIATED COLD ADVECTION DOES NOT REMAIN AS DEEP THROUGH THE
CASCADES...THERE IS A CHANCE ENOUGH OF THE COLUMN MAY WARM ENOUGH TO
CHANGE PRECIPITATION TO SLEET IN THE PDX/VUO METRO THIS AFTERNOON AND
TONIGHT. THIS WOULD CONSIDERABLY CUT DOWN THE SNOW ACCUMULATION
POTENTIAL. THE BEST CHANCE FOR THIS TO HAPPEN IN THE NORTH WILLAMETTE
VALLEY WILL BE IN CLACKAMAS COUNTY...BUT IT IS POSSIBLE THROUGHOUT
THE PDX/VUO METRO AREA.
ALSO THERE IS A CHANCE THAT THE LOW OFFSHORE COULD CONTINUE TO
RAPIDLY INTENSIFY...PUSHING UP THE COAST AND DRAGGING WITH IT MORE
LOW-LEVEL SOUTHERLY FLOW IF IT MOVES ONSHORE. THIS WOULD CHANGE
EUGENE TO RAIN EARLY AND CONSIDERABLY CUT BACK ON THEIR ICE
ACCUMULATIONS...POTENTIALLY PUTTING THE PDX/VUO METRO IN THE
CROSSHAIRS FOR A MAJOR ICE EVENT. THIS APPEARS UNLIKELY...AS THE MAIN
BAROCLINIC ZONE REMAINS NEAR THE LANE/DOUGLAS COUNTY LINE...AND THIS
IS OFTEN WHERE LOWS TEND TO TRACK. MORE LIKELY THE LOW WILL APPROACH
THE COAST AND OCCLUDE AS IT ENCOUNTERS THE STRONG COLD POOL
ENTRENCHED OVER NW OREGON.
THE UPPER ENERGY MOVES ACROSS THE CASCADES EARLY SUN MORNING AND
PRECIP WILL TAPER TO SHOWERS THEREAFTER. IT IS LIKELY TEMPERATURES
WILL MODERATE JUST A BIT SUNDAY...POTENTIALLY ENOUGH TO START THAWING
OUT SOME AREAS THAT GET HIT HARD BY SNOW AND ICE TODAY AND TONIGHT.
BUCKLE YOUR SEAT BELTS FOLKS...ITS GOING TO BE AN INTERESTING RIDE
TODAY AND TONIGHT. WEAGLE
.MEDIUM AND LONG TERM...MONDAY THROUGH FRIDAY...MOST ALL AREAS WILL
BE MILDER BY MON AM...WITH TEMPERATURES ABOVE FREEZING.
HOWEVER...WITH COLD AIR STILL LOCKED IN THE COLUMBIA BASIN...WILL
STILL HAVE COLD AIR BLEEDING INTO THE GORGE. WILL KEEP AREAS OF
FREEZING RAIN IN THE GORGE AND UPPER HOOD RIVER VALLEY DURING THE
MORNING. BY AFTERNOON...MILDER AIR WILL FINALLY REACH THOSE
AREAS...WITH GRADUAL WARM UP.
MODELS ALL INDICATE A MUCH MORE PROGRESSIVE PATTERN OVER THE REGION
FOR NEXT WEEK. THIS WILL BRING RAIN...WITH SNOW CONFINED TO THE
HIGHER CASCADES. SYSTEM PASSING ACROSS REGION TUE NIGHT/WED WITH
ANOTHER STRONG FRONT ON THU. THESE WILL BRING FAIRLY DECENT ROUND OF
RAIN. SNOW LEVELS 5K FT ON TUE/TUE NIGHT...THEN SETTLE AROUND 3500
TO 4500 FT. LOOKS GOOD FOR BUILDING CASCADES SNOWPACK. ROCKEY.
&&
.AVIATION...A MIX OF FLIGHT CONDITIONS THIS MORNING...PRIMARILY
MVFR TO LOW-END VFR AT THE TAF SITES. EXPECT CONDITIONS TO LOWER
INTO IFR THROUGHOUT MUCH OF THE REGION AFTER 18Z...STARTING IN THE
SOUTH AND SPREADING NORTH THROUGH THE EARLY AFTERNOON. PRECIP TYPE
WILL BE A CHALLENGE. HIGH CONFIDENCE IN -FZRA IN THE CENTRAL AND
SOUTH WILLAMETTE VALLEY...AND OREGON CASCADE FOOTHILLS THROUGH 06Z
SUN. NORTH WILLAMETTE VALLEY AND SW WA LIKELY TO BE IFR IN SNOW
THROUGH 06Z SUN. PRECIP DIMINISHES AFTER 06Z...BUT STILL EXPECT
WIDESPREAD IFR TO MVFR. ELEVATED TERRAIN WILL BE OBSCURED AND
ICING WILL BECOME MORE OF A SIGNIFICANT FLIGHT ISSUE THROUGH THE
FORECAST PERIOD.
KPDX AND APPROACHES...VFR AS OF 16Z BUT WILL NOT LAST MUCH LONGER.
NEXT ROUND OF PRECIP SHOULD REACH THE TERMINAL AROUND 18Z.
CONDITIONS TO DROP INTO IFR IN SNOW. PRECIP TO REMAIN AS SNOW
THROUGH AT LEAST 03Z SUN...AND POSSIBLY AS LONG AS 06Z.
ADDITIONAL ACCUMULATIONS OF 2 TO 6 INCHES POSSIBLE BEFORE CHANGING
TO -FZRA. LOOKS LIKE MORE -FZRA AND SLEET THREAT FOR THE TERMINAL
AFTER 06Z SUN...BUT FORTUNATELY PRECIP WILL BE DIMINISHING. IFR TO
LOW-END MVFR TO PREVAIL AFTER 06Z SUN. WEISHAAR
&&
.MARINE...EAST OFFSHORE WIND CONTINUES THIS MORNING. STILL GETTING
GUSTS 25 TO 30 KT AT BUOY 029. BASED ON LATEST MODEL GUIDANCE WILL
EXTEND THE SMALL CRAFT ADVISORY FOR WIND IN THE NORTH WATERS
THROUGH 22Z. GFS WOULD SUGGEST POSSIBLE 20-25 KT S-SW WIND ACROSS
THE FAR SRN WATERS LATE TODAY. NAM AND ECMWF MAINTAIN EAST WIND
AND HAVE TRENDED TOWARD THOSE SOLUTIONS. THE WIND IS EXPECTED TO
INCREASE BACK INTO SMALL CRAFT RANGE THROUGHOUT THE COASTAL WATERS
SUN NIGHT AND MON. A STRONGER SYSTEM TUE NIGHT AND WED COULD
PRODUCE GALES.
SEAS RUNNING A COUPLE FEET HIGHER THAN GUIDANCE THIS MORNING. NRN
BUOYS AT 7-8 FT...DESPITE THE EAST WIND. HAVE NUDGED SEAS UP A
FOOT OR SO TODAY AND TONIGHT. SEAS TO REMAIN BELOW 10 FT THROUGH
MON NIGHT. SWELL THROUGH MON NIGHT WILL BE DOMINATED BY A SHORT
PERIOD FRESH SWELL FROM THE S TO SW. SEAS MAY APPROACH MID TEENS
WITH THE STRONGER SYSTEM TUE AND TUE NIGHT. WEISHAAR
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER STORM WARNING UNTIL 4 AM PST SUNDAY FOR GREATER PORTLAND
METRO AREA-NORTHERN OREGON CASCADES-UPPER HOOD RIVER VALLEY.
WINTER WEATHER ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR
CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 4 AM PST
SUNDAY FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER
GORGE.
WINTER STORM WARNING UNTIL 4 AM PST SUNDAY FOR CASCADES IN LANE
COUNTY-CENTRAL WILLAMETTE VALLEY-COAST RANGE OF NORTHWEST
OREGON-NORTHERN OREGON CASCADE FOOTHILLS.
ICE STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CASCADE
FOOTHILLS IN LANE COUNTY-SOUTH WILLAMETTE VALLEY.
WINTER WEATHER ADVISORY UNTIL 4 AM PST SUNDAY FOR LOWER
COLUMBIA.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CENTRAL
COAST RANGE OF WESTERN OREGON.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR NORTH
OREGON COAST.
WA...WINTER STORM WARNING UNTIL 4 AM PST SUNDAY FOR GREATER
VANCOUVER AREA.
WINTER WEATHER ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR
CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 4 AM PST
SUNDAY FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER
GORGE.
WINTER WEATHER ADVISORY UNTIL 4 AM PST SUNDAY FOR I-5 CORRIDOR
IN COWLITZ COUNTY-SOUTH WASHINGTON CASCADE FOOTHILLS.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 2 PM PST THIS AFTERNOON
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD
OR OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1142 AM CST SAT FEB 8 2014
.UPDATE...
SEE THE UPDATED AVIATION DISCUSSION BELOW.
LATEST RUC AND SREF BRING SOME LIGHT SNOW INTO SOUTHWESTERN
COUNTIES...WITH THE SREF GOING SO FAR AS TO SUGGEST CERTAINTY
ALONG PORTIONS OF THE WHITE RIVER. THEREFORE...ADDED A CHANCE
MENTION OF POPS FOR SOUTHERN JONES/LYMAN COUNTIES. NO OTHER
CHANGES OF NOTE.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
SMALL AND COMPACT VORT MAX IS SPINNING ITS WAY EASTWARD RIGHT
ALONG I-90 ACROSS SOUTHERN SOUTH DAKOTA. IT IS PRODUCING SNOWFALL
ACROSS THE SOUTHWEST CWA AND WILL BE OUT OF THE AREA FAIRLY SOON
AND OFF INTO FSD CWA. A QUICK BURST OF LIGHT TO MODERATE SNOW HAS
BEEN OBSERVED ON WEB CAMS AND IT APPEARS ACCUMS HAVE BEEN RATHER
LIGHT.
THE REST OF THE SHORT TERM PERIOD IS QUIET AND COLD WHICH IS
NOTHING NEW. ARCTIC HIGH PRESSURE SLOWLY BUILDS SOUTHEAST INTO THE
DAKOTAS THROUGH MONDAY MORNING. TEMPS ALOFT GET PROGRESSIVELY
COLDER INTO SUNDAY...WITH THE CORE OF THE COLD AIR SETTLING OVER
THE AREA MONDAY MORNING. IDEAL RADIATIONAL COOLING MONDAY MORNING
MAY ALLOW MORNING LOWS TO REACH 20 BELOW ZERO.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
THE MEAN FLOW THROUGH THE LONG TERM SEEMS TO FAVOR A LOW
AMPLITUDE POSITIVE PNA PATTERN...IE A MID LEVEL RIDGE OVER THE
WESTERN CONUS WITH DOWNSTREAM TROF OVER THE EAST. THIS OVERALL
PATTERN SHOULD FAVOR A LITTLE WARMER TEMPERATURES...ESPECIALLY THE
SOUTHWEST CWA. THERE IS ALSO SOME CHANCE FOR PCPN...PARTICULARLY
IN THE TUESDAY NIGHT THROUGH THURSDAY TIME FRAME...DEPENDING UPON
THE MODEL YOU USE. ALL MODELS INDICATE AN ACTIVE STORM TRACK FOR
THAT TIME PERIOD...BUT WITH DIFFERENCES ON THE TIMING/TRACK OF
ENERGY. THESE DIFFERENCES MEAN STICKING TO A MODEL BLEND FOR THE
FORECAST IS THE BEST FORECAST MOVE. TEMPERATURES OVERALL SHOULD BE
CLOSER TO NORMAL VS RECENT TEMPERATURES.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
LIGHT SNOW CURRENTLY ONGOING ACROSS SOUTHWEST SOUTH DAKOTA MAY
SNEAK INTO THE KPIR REGION LATER THIS AFTERNOON AND EVENING. CIGS
MAY LOWER INTO THE MVFR CATEGORY BUT DO NOT ANTICIPATE ANY
SIGNIFICANT REDUCTION TO VSBYS AT THIS POINT. THE REMAINING TAF
SITES WILL BE VFR THROUGH THE AFTERNOON...BUT AN AREA OF MVFR
STRATUS IS EXPECTED TO SPREAD ACROSS THE WHOLE REGION TONIGHT. 5
TO 10 KT NORTHWEST WINDS WILL PREVAIL.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...CONNELLY
SHORT TERM...TMT
LONG TERM...TDK
AVIATION...SERR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1050 AM CST SAT FEB 8 2014
.UPDATE...
LATEST RUC AND SREF BRING SOME LIGHT SNOW INTO SOUTHWESTERN
COUNTIES...WITH THE SREF GOING SO FAR AS TO SUGGEST CERTAINTY
ALONG PORTIONS OF THE WHITE RIVER. THEREFORE...ADDED A CHANCE
MENTION OF POPS FOR SOUTHERN JONES/LYMAN COUNTIES. NO OTHER
CHANGES OF NOTE.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
SMALL AND COMPACT VORT MAX IS SPINNING ITS WAY EASTWARD RIGHT
ALONG I-90 ACROSS SOUTHERN SOUTH DAKOTA. IT IS PRODUCING SNOWFALL
ACROSS THE SOUTHWEST CWA AND WILL BE OUT OF THE AREA FAIRLY SOON
AND OFF INTO FSD CWA. A QUICK BURST OF LIGHT TO MODERATE SNOW HAS
BEEN OBSERVED ON WEB CAMS AND IT APPEARS ACCUMS HAVE BEEN RATHER
LIGHT.
THE REST OF THE SHORT TERM PERIOD IS QUIET AND COLD WHICH IS
NOTHING NEW. ARCTIC HIGH PRESSURE SLOWLY BUILDS SOUTHEAST INTO THE
DAKOTAS THROUGH MONDAY MORNING. TEMPS ALOFT GET PROGRESSIVELY
COLDER INTO SUNDAY...WITH THE CORE OF THE COLD AIR SETTLING OVER
THE AREA MONDAY MORNING. IDEAL RADIATIONAL COOLING MONDAY MORNING
MAY ALLOW MORNING LOWS TO REACH 20 BELOW ZERO.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
THE MEAN FLOW THROUGH THE LONG TERM SEEMS TO FAVOR A LOW AMPLITUDE
POSITIVE PNA PATTERN...IE A MID LEVEL RIDGE OVER THE WESTERN CONUS
WITH DOWNSTREAM TROF OVER THE EAST. THIS OVERALL PATTERN SHOULD
FAVOR A LITTLE WARMER TEMPERATURES...ESPECIALLY THE SOUTHWEST CWA.
THERE IS ALSO SOME CHANCE FOR PCPN...PARTICULARLY IN THE TUESDAY
NIGHT THROUGH THURSDAY TIME FRAME...DEPENDING UPON THE MODEL YOU
USE. ALL MODELS INDICATE AN ACTIVE STORM TRACK FOR THAT TIME
PERIOD...BUT WITH DIFFERENCES ON THE TIMING/TRACK OF ENERGY. THESE
DIFFERENCES MEAN STICKING TO A MODEL BLEND FOR THE FORECAST IS THE
BEST FORECAST MOVE. TEMPERATURES OVERALL SHOULD BE CLOSER TO
NORMAL VS RECENT TEMPERATURES.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
A FEW FLURRIES ARE POSSIBLE AT KPIR THIS MORNING OTHERWISE IT
SHOULD BE DRY ACROSS THE REGION. MEANWHILE A BATCH OF MVFR STRATUS
FLOWING NORTH MAY AFFECT KATY FOR A FEW HOUR THIS MORNING BEFORE
MOVING EAST. THE REMAINING TERMINALS SHOULD BE VFR THROUGH TODAY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...CONNELLY
SHORT TERM...TMT
LONG TERM...TDK
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1231 PM CST SAT FEB 8 2014
.UPDATE...
UPDATED TO INCLUDE THE 18Z AVIATION DISCUSSION BELOW.
JCL
&&
.DISCUSSION... /ISSUED 1058 AM CST SAT FEB 8 2014/
DISCUSSION...LATEST WATER VAPOR SATELLITE/WSR-88D VAD WIND
PROFILES INDICATE THE SHORTWAVE WHICH PRODUCED THE WINTRY
PRECIPITATION ACROSS THE MID SOUTH OVERNIGHT HAS MOVED EAST OF THE
AREA LATE THIS MORNING. A VERY SUBTLE BUT WEAK 700 MB SHORTWAVE IS
LOCATED ACROSS PORTIONS OF NORTHEAST TEXAS...SOUTHERN ARKANSAS AND
NORTHERN LOUISIANA. NO ADDITIONAL PRECIPITATION IS EXPECTED ACROSS
THE MID SOUTH FOR THE REMAINDER OF TODAY. AS OF 10 AM
CST...TEMPERATURES RANGE FROM THE 20S NORTH OF I-40 AND UPPER 20S
TO MAINLY LOWER 30S ACROSS AREAS ALONG AND SOUTH OF I-40. VISIBLE
SATELLITE TRENDS SHOW AN LARGE AREA OF LOW CLOUDS ENCOMPASSING THE
LOWER MISSISSIPPI VALLEY AND EXTENDING INTO THE SOUTHERN PLAINS.
WILL MAKE MINOR ADJUSTMENTS TO ACCOUNT FOR LATEST SHORT TERM
TRENDS. OTHERWISE...FORECAST OVERALL IS IN GOOD SHAPE.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
PREV DISCUSSION... /ISSUED 401 AM CST SAT FEB 8 2014/
CURRENTLY...A MID LEVEL DISTURBANCE IS MOVING THROUGH THE LOWER
MISSISSIPPI VALLEY ATTM. LIGHT SNOW CONTINUES ROUGHLY NORTH OF A
TUNICA TO CORINTH LINE WITH A MIX OF LIGHT SNOW...SLEET AND
FREEZING RAIN TO THE SOUTH WHERE A LITTLE BIT OF WARM AIR HAS
SNUCK IN BETWEEN 950 AND 900 MB. TEMPS RANGE FROM THE UPPER TEENS
ACROSS NE AR TO LOWER 30S TOWARD MONROE COUNTY MS. SO FAR MANY
PLACES HAVE RECEIVED ABOUT AN 1/2 INCH TO AN INCH WITH UP TO 2
INCHES IN A BAND FROM POINSETT AND CROSS TOWARD TIPTON AND
LAUDERDALE COUNTIES.
TODAY...LATEST NAM AND HRRR SHOWS SOME PRECIP LINGERING THROUGH
MID MORNING. PRECIP WILL BE LIGHT WITH MAINLY LIGHT SNOW NORTH OF
THE TN/MS LINE AND A MIXTURE OF PRECIP TYPES TO THE SOUTH. PRECIP
MAY WIND DOWN AS A PERIOD OF FREEZING DRIZZLE AS WELL. AS A RESULT
DECIDED TO EXTEND THE ADVISORY UNTIL 9 AM CST. EXPECT CLOUDY
CONDITIONS THIS AFTERNOON AND WITH THE NEWLY FALLEN SNOW TEMPS
SHOULD STRUGGLE TO REACH GUIDANCE NUMBERS SO UNDERCUT THEM
SUBSTANTIALLY.
TONIGHT...CLOUDS WILL HANG IN WHICH WILL KEEP TEMPS FROM FREE
FALLING. EXPECT LOWS IN THE 20S TO LOWER 30S.
SUNDAY...NEXT ARCTIC FRONT PUSHES THOUGH DURING THE AFTERNOON.
EXPECT CLOUDY SKIES TO CONTINUE WHILE TEMPS WILL WARM AHEAD OF THE
FRONT. HIGHS WILL RANGE FROM THE UPPER 30S OVER NE AR TO LOWER
50S OVER NE MS.
SUNDAY NIGHT THROUGH MONDAY...UNSETTLED AND COLD PERIOD ACROSS
THE MIDSOUTH AS AN ARCTIC AIRMASS FILTERS IN. THE 00Z ECMWF HAS
JOINED THE GFS AND KEEPS ANY SURFACE WAVE THAT DEVELOPS ALONG THE
ARCTIC FRONT PUSHING THROUGH THE LOWER MISSISSIPPI VALLEY WELL
TO THE SOUTH. AS A RESULT PRECIP CHANCES REMAIN SMALL SUNDAY NIGHT
INTO MONDAY. IF PRECIP DOES OCCUR IT WILL BE OF THE WINTER VARIETY
ACROSS MUCH OF THE AREA. THE NAM IS THE OUTLIER NOW WITH A
SURFACE LOW MOVING FROM THE ARKLATEX INTO CENTRAL MISSISSIPPI
RESULTING IN HIGHER PRECIP CHANCES ACROSS NORTH MISSISSIPPI SUN
NIGHT INTO MONDAY. WILL NEED TO WATCH BUT FOR NOW WILL FOLLOW THE
GFS/ECMWF SOLUTION. TEMPS WILL BE BACK IN THE FREEZER BY MONDAY
WITH HIGHS IN THE 20S AND 30S.
MONDAY NIGHT INTO TUESDAY...PERHAPS THE BEST CHANCE FOR WINTER
WEATHER WILL BE DURING THIS TIME FRAME. THE ARCTIC AIRMASS WILL BE
ENTRENCHED OVER THE AREA WHILE AN UPPER LEVEL DISTURBANCE WITH
GOOD MOISTURE AND SOME LIFT PUSHES THROUGH. THE GFS IS MOST
AGGRESSIVE WITH PRECIP AMOUNTS AND SUGGESTS 1-2 INCHES OF SNOW
WITH THE ECMWF SHOWING LESSER AMOUNTS. THE NAM IS ALSO PICKING UP
THIS DISTURBANCE. AS A RESULT HAVE INCREASED POPS TO 50 PERCENT
ACROSS MUCH OF THE AREA. PRECIP TYPE WOULD BE MAINLY SNOW WITH
SOME SLEET POSSIBLE SOUTH. PRECIP WILL TAPER OFF TUESDAY WITH SOME
LINGERING SNOW OVER NORTH MISSISSIPPI. TUESDAY WILL BE COLD WITH
HIGHS IN THE 20S AND 30S.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...ARCTIC HIGH PRESSURE
LOOSES ITS GRIP ACROSS THE AREA ON WEDNESDAY AND TEMPS START TO
WARM. A POTENT UPPER TROUGH DROPS INTO THE CENTER OF THE COUNTRY
WEDNESDAY INTO WEDNESDAY NIGHT AND A SURFACE LOW BEGINS TO DEVELOP
ALONG THE EASTERN SEABOARD WITH MOST OF THE MOISTURE AND LIFT
REMAINING EAST OF THE MIDSOUTH. AS A RESULT PRECIP CHANCES ARE NOT
GREAT DURING THIS TIME FRAME.
THURSDAY AND FRIDAY...LOOKS DRY AND MILDER WITH TEMPS CLOSER TO
NORMAL.
SJM
&&
.AVIATION...
18Z TAF CYCLE (08/18Z-09/18Z)
CEILINGS ARE EXPECTED TO LIFT TO MVFR AT KMEM AROUND 19Z...ALTHOUGH
CONFIDENCE IS LOW ON HOW QUICKLY THIS OCCURS. THIS WILL LEAVE MVFR
CONDITIONS AT THE TAF SITES THIS AFTERNOON AND MUCH OF TONIGHT.
CONDITIONS LOWERING TO IFR AFTER 09/09Z...IMPROVING TO MVFR AROUND
09/15Z EXCEPT REMAINING IFR AT KJBR. WILL NEED TO MONITOR FOR THE
POSSIBILITY OF PATCHY DRIZZLE OR FREEZING DRIZZLE LATE TONIGHT AND
EARLY SUNDAY...BUT CONFIDENCE IS TOO LOW TO MENTION ATTM. WINDS
LIGHT THROUGH THE PERIOD.
JCL
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 33 30 47 28 / 30 0 10 30
MKL 32 26 46 26 / 40 0 10 30
JBR 28 25 39 22 / 20 0 10 30
TUP 39 31 53 35 / 40 0 10 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1058 AM CST SAT FEB 8 2014
.DISCUSSION...LATEST WATER VAPOR SATELLITE/WSR-88D VAD WIND
PROFILES INDICATE THE SHORTWAVE WHICH PRODUCED THE WINTRY
PRECIPITATION ACROSS THE MID SOUTH OVERNIGHT HAS MOVED EAST OF THE
AREA LATE THIS MORNING. A VERY SUBTLE BUT WEAK 700 MB SHORTWAVE IS
LOCATED ACROSS PORTIONS OF NORTHEAST TEXAS...SOUTHERN ARKANSAS AND
NORTHERN LOUISIANA. NO ADDITIONAL PRECIPITATION IS EXPECTED ACROSS
THE MID SOUTH FOR THE REMAINDER OF TODAY. AS OF 10 AM
CST...TEMPERATURES RANGE FROM THE 20S NORTH OF I-40 AND UPPER 20S
TO MAINLY LOWER 30S ACROSS AREAS ALONG AND SOUTH OF I-40. VISIBLE
SATELLITE TRENDS SHOW AN LARGE AREA OF LOW CLOUDS ENCOMPASSING THE
LOWER MISSISSIPPI VALLEY AND EXTENDING INTO THE SOUTHERN PLAINS.
WILL MAKE MINOR ADJUSTMENTS TO ACCOUNT FOR LATEST SHORT TERM
TRENDS. OTHERWISE...FORECAST OVERALL IS IN GOOD SHAPE.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
&&
.PREV DISCUSSION... /ISSUED 519 AM CST SAT FEB 8 2014/
UPDATE...
UPDATED FOR 12Z AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 401 AM CST SAT FEB 8 2014/
DISCUSSION...
CURRENTLY...A MID LEVEL DISTURBANCE IS MOVING THROUGH THE LOWER
MISSISSIPPI VALLEY ATTM. LIGHT SNOW CONTINUES ROUGHLY NORTH OF A
TUNICA TO CORINTH LINE WITH A MIX OF LIGHT SNOW...SLEET AND
FREEZING RAIN TO THE SOUTH WHERE A LITTLE BIT OF WARM AIR HAS
SNUCK IN BETWEEN 950 AND 900 MB. TEMPS RANGE FROM THE UPPER TEENS
ACROSS NE AR TO LOWER 30S TOWARD MONROE COUNTY MS. SO FAR MANY
PLACES HAVE RECEIVED ABOUT AN 1/2 INCH TO AN INCH WITH UP TO 2
INCHES IN A BAND FROM POINSETT AND CROSS TOWARD TIPTON AND
LAUDERDALE COUNTIES.
TODAY...LATEST NAM AND HRRR SHOWS SOME PRECIP LINGERING THROUGH
MID MORNING. PRECIP WILL BE LIGHT WITH MAINLY LIGHT SNOW NORTH OF
THE TN/MS LINE AND A MIXTURE OF PRECIP TYPES TO THE SOUTH. PRECIP
MAY WIND DOWN AS A PERIOD OF FREEZING DRIZZLE AS WELL. AS A RESULT
DECIDED TO EXTEND THE ADVISORY UNTIL 9 AM CST. EXPECT CLOUDY
CONDITIONS THIS AFTERNOON AND WITH THE NEWLY FALLEN SNOW TEMPS
SHOULD STRUGGLE TO REACH GUIDANCE NUMBERS SO UNDERCUT THEM
SUBSTANTIALLY.
TONIGHT...CLOUDS WILL HANG IN WHICH WILL KEEP TEMPS FROM FREE
FALLING. EXPECT LOWS IN THE 20S TO LOWER 30S.
SUNDAY...NEXT ARCTIC FRONT PUSHES THOUGH DURING THE AFTERNOON.
EXPECT CLOUDY SKIES TO CONTINUE WHILE TEMPS WILL WARM AHEAD OF THE
FRONT. HIGHS WILL RANGE FROM THE UPPER 30S OVER NE AR TO LOWER
50S OVER NE MS.
SUNDAY NIGHT THROUGH MONDAY...UNSETTLED AND COLD PERIOD ACROSS
THE MIDSOUTH AS AN ARCTIC AIRMASS FILTERS IN. THE 00Z ECMWF HAS
JOINED THE GFS AND KEEPS ANY SURFACE WAVE THAT DEVELOPS ALONG THE
ARCTIC FRONT PUSHING THROUGH THE LOWER MISSISSIPPI VALLEY WELL
TO THE SOUTH. AS A RESULT PRECIP CHANCES REMAIN SMALL SUNDAY NIGHT
INTO MONDAY. IF PRECIP DOES OCCUR IT WILL BE OF THE WINTER VARIETY
ACROSS MUCH OF THE AREA. THE NAM IS THE OUTLIER NOW WITH A
SURFACE LOW MOVING FROM THE ARKLATEX INTO CENTRAL MISSISSIPPI
RESULTING IN HIGHER PRECIP CHANCES ACROSS NORTH MISSISSIPPI SUN
NIGHT INTO MONDAY. WILL NEED TO WATCH BUT FOR NOW WILL FOLLOW THE
GFS/ECMWF SOLUTION. TEMPS WILL BE BACK IN THE FREEZER BY MONDAY
WITH HIGHS IN THE 20S AND 30S.
MONDAY NIGHT INTO TUESDAY...PERHAPS THE BEST CHANCE FOR WINTER
WEATHER WILL BE DURING THIS TIME FRAME. THE ARCTIC AIRMASS WILL BE
ENTRENCHED OVER THE AREA WHILE AN UPPER LEVEL DISTURBANCE WITH
GOOD MOISTURE AND SOME LIFT PUSHES THROUGH. THE GFS IS MOST
AGGRESSIVE WITH PRECIP AMOUNTS AND SUGGESTS 1-2 INCHES OF SNOW
WITH THE ECMWF SHOWING LESSER AMOUNTS. THE NAM IS ALSO PICKING UP
THIS DISTURBANCE. AS A RESULT HAVE INCREASED POPS TO 50 PERCENT
ACROSS MUCH OF THE AREA. PRECIP TYPE WOULD BE MAINLY SNOW WITH
SOME SLEET POSSIBLE SOUTH. PRECIP WILL TAPER OFF TUESDAY WITH SOME
LINGERING SNOW OVER NORTH MISSISSIPPI. TUESDAY WILL BE COLD WITH
HIGHS IN THE 20S AND 30S.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...ARCTIC HIGH PRESSURE
LOOSES ITS GRIP ACROSS THE AREA ON WEDNESDAY AND TEMPS START TO
WARM. A POTENT UPPER TROUGH DROPS INTO THE CENTER OF THE COUNTRY
WEDNESDAY INTO WEDNESDAY NIGHT AND A SURFACE LOW BEGINS TO DEVELOP
ALONG THE EASTERN SEABOARD WITH MOST OF THE MOISTURE AND LIFT
REMAINING EAST OF THE MIDSOUTH. AS A RESULT PRECIP CHANCES ARE NOT
GREAT DURING THIS TIME FRAME.
THURSDAY AND FRIDAY...LOOKS DRY AND MILDER WITH TEMPS CLOSER TO
NORMAL.
SJM
&&
.AVIATION...
12Z TAF SET
VARIED CIGS EXPECTED AT TAF SITES THIS MORNING WITH THE LOWEST/IFR
CONDITIONS AT MEM AND MKL. FEEL THAT MORE UNIFORM MVFR CIGS WILL
SETUP FROM LATE MORNING THROUGH THE AFTERNOON. NOT CONFIDENT THAT
THIS DECK WILL REMAIN DURING THE EARLY EVENING HOURS...SO HAVE
GONE VFR FOR MOST OF THE NIGHT. AS A WEAK SYSTEM MOVES IN FROM THE
NORTHWEST MVFR CIGS MAY EASILY RETURN AFTER MIDNIGHT...ALONG WITH
SOME LIGHT FOG. IT IS ALSO POSSIBLE THAT LIGHT FREEZING DRIZZLE
MAY DEVELOP NEAR JBR AND MEM BY 09/12Z. FOR NOW CONFIDENCE IS NOT
HIGH ENOUGH FOR THIS OCCURRING. LIGHT AND VARIABLE WINDS WILL
BECOME SOUTHWEST...THEN TURN EITHER CALM OR VARIABLE LATE.
JAB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 33 30 47 28 / 30 10 10 30
MKL 32 26 46 26 / 40 10 10 30
JBR 28 25 39 22 / 20 10 10 30
TUP 39 31 53 35 / 40 10 10 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1201 PM CST SAT FEB 8 2014
.UPDATE...
WILL LET THE FREEZING FOG ADVISORY EXPIRE AT NOON AS VISIBILITIES
HAVE IMPROVED DRASTICALLY THE PAST HOUR IN CHILDRESS AS WEST WINDS
ATTEMPT TO MOVE IN AND PROVIDE FOR SOME DEEPER MIXING.
OTHERWISE...ONLY MINOR ADJUSTMENTS TO TEMPERATURES AND INCREASED
WINDS A FEW MPH ON THE CAPROCK AS SPEEDS HAVE COME UP INTO THE
20-25 MPH RANGE WITH GUSTS ABOVE 30 MPH.
&&
.AVIATION...
WEST WINDS WILL CONTINUE TO BE BREEZY/GUSTY AT KLBB WITH SPEEDS
AROUND 20 KNOTS GUSTING TO 30 KNOTS OR GREATER THIS AFTERNOON
AHEAD OF A SURFACE TROUGH. WHILE VFR CONDITIONS WILL HOLD AT
KLBB...KCDS WILL STILL SEE IFR CONDITIONS INTO THE AFTERNOON AS
CEILINGS HAVE BEEN VERY SLOW TO LIFT WHILE VISIBILITIES HAVE COME
UP INTO THE VFR CATEGORY. WILL LEAVE PREVAILING IFR CEILINGS IN
THROUGH 19Z BEFORE INTRODUCING VFR CONDITIONS AS WINDS SHOULD COME
AROUND TO THE WEST AND HELP MIX MUCH OF THE LOW CLOUDINESS OUT.
QUESTIONS ARISE AGAIN THIS EVENING AND TONIGHT AS TO WHETHER SUB-
VFR CEILINGS WILL DEVELOP...BUT HAVE ELECTED TO MAINTAIN
PREVAILING VFR CRITERIA AT THIS TIME WHILE MENTIONING A SCATTERED
DECK BELOW FL010.
&&
PREV DISCUSSION... /ISSUED 445 AM CST SAT FEB 8 2014/
SHORT TERM...
DESPITE STEADY SW WINDS OF 10-15 KNOTS OVERNIGHT...A SURFACE
TROUGH STRUGGLED TO MAKE HEADWAY OFF THE CAPROCK AND AS A RESULT
OUR NERN COUNTIES WERE INVADED BY MOIST SE WINDS COMPLETE WITH
STRATUS AND FREEZING FOG. CONSIDERING WE HAVE NO MEANINGFUL
IMPULSES PASSING THROUGH TODAY IN THIS FLAT NW UPPER FLOW
REGIME...ANY EASTWARD ADVANCE OF THE SURFACE TROUGH WILL HEAVILY
DEPEND ON DAYTIME MIXING. SUCH FEATS USUALLY DON/T COME EASY OFF
THE CAPROCK WHEN STRATUS IS ALREADY ENTRENCHED...SO WE WILL GIVE
THE NOD TO THE HRRR WHICH KEEPS CHILDRESS AND SURROUNDING LOCALES
SOCKED IN LOW CLOUDS UNTIL CLOSE TO NOON. EARLIER CALL TO MEMPHIS
INDICATED VIS OF JUST 1.5 BLOCKS. CONDITIONS ARE DETERIORATING
ENOUGH AT CHILDRESS AND WITH LOW CLOUDS STILL EXPANDING SLOWLY
SOUTH PER 11-3.9 IMAGERY...HAVE OPTED FOR A FREEZING FOG ADVISORY
UNTIL 16Z FOR OUR NERN COUNTIES.
THE OTHER CHALLENGE TODAY IS MAX TEMPS. ANYONE VIEWING OUR MAX
TEMP GRID IN NDFD MIGHT THINK WE/RE PAYING HOMAGE TO PICASSO...
BUT THIS IS SOLELY THE RESULT OF A STUBBORN SNOWPACK/HIGH ALBEDO
FROM GRAHAM NORTHEAST TO GUTHRIE. FARTHER WEST...DRY SOILS AND
15-20 MPH WEST WINDS BY PEAK HEATING WILL EASILY PUSH HIGHS INTO
THE 60S...PERHAPS EVEN 70 IN A FEW SPOTS. ALONG THESE LINES...
AFTERNOON RH VALUES WILL TUMBLE INTO THE UPPER TEENS...BUT THE
SHORT DURATION OF THESE LOW HUMIDITIES /90 MIN OR LESS/ SEEMS
UNSUPPORTIVE OF EVEN A RANGELAND FIRE DANGER STATEMENT AT THIS
TIME.
EXPECT EVEN MILDER LOWS TONIGHT UNDER INCREASING HIGH CLOUDS AND
WIDESPREAD WESTERLY WINDS AOA 10 MPH.
LONG TERM...
BIGGEST CHANGE IN THE MODELS HAS BEEN WITH PRECIPITATION CHANCES
FOR MONDAY EVENING INTO TUESDAY MORNING. MODELS HAVE CHANGED TO A
DRIER FORECAST THAN IN PREVIOUS RUNS BUT THE INCOMING 06Z RUNS ARE
GOING BACK TOWARDS A BIT MORE PRECIP THAN THE 00Z RUNS DID. PART
OF THIS APPEARS TO BE A CONTINUED SLOWER TREND WITH THE PASSAGE OF
THE WAVE. ONLY SIMILARITY IN THE GRIDS IS THAT THERE IS A MEAGER
AMOUNT OF MOISTURE AVAILABLE FOR THIS SYSTEM SO ANY PRECIPITATION
THAT DOES OCCUR SHOULD BE ON THE LIGHT SIDE. WITH ADDED
UNCERTAINTY ON THE TIMING...OPTED TO KEEP THE POP GRIDS UNCHANGED
FOR NOW TO SEE IF THE MODELS WILL CONTINUE THE TREND OF SLOWING
THE WAVE DOWN OR IF THEY SPEED THE TIMING UP ONCE AGAIN. OTHER
CHANCE WAS IN TEMPERATURES ACROSS THE REGION WITH GUIDANCE COMING
IN ABOUT 10 TO 15 DEGREES WARMER THAN PREVIOUS RUNS. WITH THE COLD
FRONT ARRIVING ON LATE SUNDAY/EARLY MONDAY AND A CONTINUED NORTH
TO NORTHEASTERLY SURFACE FLOW...FEEL THAT THE MODELS ARE ERODING
THE COLD AIR TOO FAST AND UNDERCUT MEX GUIDANCE AND REMAINED CLOSE
TO WHAT THE PREVIOUS FORECAST HAD.
BEYOND TUESDAY...NORTHWESTERLY FLOW ALOFT LOOKS TO REMAIN IN PLACE
ACROSS THE REGION. THIS SHOULD ALLOW WEAK LEE SURFACE TROFING TO
TAKE PLACE AND BEGIN A GRADUAL WARMUP IN TEMPERATURES BACK INTO
THE MID TO UPPER 60S.
JORDAN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 31 59 20 38 19 / 0 0 10 10 30
TULIA 30 56 20 33 17 / 0 10 10 10 30
PLAINVIEW 30 59 21 34 18 / 0 10 10 10 30
LEVELLAND 33 67 23 40 20 / 0 0 10 10 20
LUBBOCK 32 63 22 38 19 / 0 0 10 10 20
DENVER CITY 35 70 24 43 22 / 0 0 10 10 20
BROWNFIELD 33 69 24 41 20 / 0 0 10 10 20
CHILDRESS 27 40 21 31 17 / 0 10 10 10 20
SPUR 22 49 23 34 19 / 0 0 10 10 20
ASPERMONT 29 59 24 35 21 / 0 0 10 10 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31