Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/14/13

AREA FORECAST DISCUSSION

NWS DENVER/BOULDER CO

826 PM MST WED FEB 13 2013

.UPDATE...WINDS GRADUALLY DECREASED ACROSS THE PLAINS AND
FOOTHILLS THIS EVENING AS LOW LEVEL GRADIENT AND FLOW ALOFT
RELAXED. SATELLITE SHOWS SHORT WAVE TROUGH AND BETTER MOISTURE
MOVING ACROSS THE NORTHERN ROCKIES WHICH WILL PUSH INTO COLORADO
LATE TONIGHT AND THURSDAY. FORECAST OF INCREASING SNOW IN THE
MOUNTAINS LATER TONIGHT AND THEN ON THE PLAINS THURSDAY LOOKS
GOOD. THE CHANCE OF SNOW FOR THE PLAINS APPEARS TO BE INCREASING
WITH ENOUGH MOISTURE...LIFT...AND SHALLOW ANTICYCLONIC FLOW BEHIND
THE FRONT ALL COINCIDING TOMORROW AFTERNOON/EVENING.
HOWEVER...SNOWFALL AMOUNTS ARE STILL LOOKING LIGHT WITH MAYBE AN
INCH OR TWO ACCUMULATION POSSIBLE ON THE NEARBY PLAINS. FORECAST
MOUNTAIN ACCUMULATIONS OF 4 TO 8 INCHES IN THE NORTHERN GORE AND
PARK RANGES LOOKS GOOD...WITH AMOUNTS CLOSER TO 2 TO 6 INCHES IN
THE FRONT RANGE MOUNTAINS GRADUALLY DECREASING TOWARD THE I-70
CORRIDOR.

.AVIATION...WEAK NORTHERLY PUSH HAS REACHED KDEN THIS EVENING BUT
SHOULD EVENTUALLY WASH OUT IN THE NEXT COUPLE HOURS WITH WEAK
SOUTHERLY WINDS DEVELOPING. KBJC WILL ALSO SEE WINDS DECREASE AS
FLOW ALOFT WEAKENS BY 06Z-07Z. COLD FRONT IS STILL EXPECTED TO
PUSH ACROSS THE AIRPORTS AROUND 15Z-16Z THURSDAY WITH A 2-4 HOUR
PERIOD OF GUSTY NORTH/NORTHEAST WINDS TO AROUND 25 KTS. COULD SEE
A COUPLE GUSTS REACH 30 KTS WITH THE FRONTAL PASSAGE AT KDEN. SNOW
SEEMS MORE LIKELY WITH ENOUGH FACTORS COMING TOGETHER TO WARRANT A
TEMPO GROUP AND LOWER CEILINGS AFTER 20Z-21Z THURSDAY IN THE FRONT
RANGE AIRPORTS.

.PREV DISCUSSION... /ISSUED 345 PM MST WED FEB 13 2013/

SHORT TERM...MODERATE NORTHWEST FLOW ALOFT ACROSS REGION. AIRMASS
FAIRLY MOIST BUT RELATIVELY STABLE. MOUNTAIN WEB CAMS SHOWING SOME
LIGHT SNOW ALONG THE CONTINENTAL DIVIDE AS THE PARK AND GORE
RANGES OF WESTERN JACKSON COUNTY. LATEST SNOTEL DATA SUGGESTING
SOME LIGHT ACCUMULATIONS IN ZONE 31 AND PORTIONS OF ZONES 33 AND
34. WINDS HAVE BEEN A BIT GUSTY ACROSS THE HIGHER RIDGES AND ALONG
THE FOOTHILLS. WEST TO NORTHWEST WINDS HAVE ALSO SPREAD ONTO THE
ADJACENT PLAINS AS WELL AS ALONG THE WYOMING AND NEBRASKA BORDERS.
LATEST RAP SHOWS MOISTURE GRADUALLY INCREASING AS LAPSE RATES
INCREASE TO AROUND 7 C/KM BY MIDNIGHT. SHOULD SEE THE SNOW
INCREASE IN COVERAGE OVERNIGHT DUE TO FAVORABLE OROGRAPHICS AND
LAPSE RATES...MAINLY NORTH OF INTERSTATE 70. THERE IS ALSO SOME
INCREASE IN MID LEVEL QG ASCENT AHEAD OF AN APPROACHING SHORTWAVE
WHICH WILL HELP WITH SNOWFALL. SNOW ACCUMULATIONS SHOULD REMAIN
BELOW ADVISORY CRITERIA. ACROSS FOOTHILLS AND PLAINS...GRADIENT
WEAKENS DURING THE EVENING. SHOULD SEE WINDS DECREASE AS A
RESULT...WITH DRAINAGE PATTERN PREVAILING. ON THURSDAY...NORTHWEST
FLOW ALOFT TO CONTINUE. MODELS CONTINUE TO SHOW WEAK SHORTWAVE
MOVING ACROSS WYOMING DURING THE AFTERNOON WITH MID LEVEL ASCENT
MOVING OVER THE AREA. LIGHT SNOW TO BE MORE WIDESPREAD OVER THE
MOUNTAINS SOUTH OF INTERSTATE 70 BY THE AFTERNOON AS OROGRAPHICS
REMAINS FAVORABLE. MODEL CROSS SECTIONS INDICATE VARYING AMOUNTS
OF MOISTURE WITH THE GFS DEEPEST. WILL INCREASE THE POPS AND
COVERAGE OF THE SNOW A BIT BUT KEEP AMOUNTS BELOW ADVISORY
CRITERIA. ACROSS PLAINS...MODELS CONTINUE TO SHOW A FRONT MOVING
SOUTH ACROSS THE AREA DURING THE MORNING...REACHING DENVER AREA
AROUND 15-18Z. NORTHERLY WINDS WITH FRONT BECOMES NORTHEAST DURING
THE AFTERNOON AS SURFACE HIGH PUSHES IN BEHIND FRONT. UPSLOPE NOT
ALL THAT DEEP ACCORDING TO THE CROSS SECTIONS BUT DOES REACH THE
FOOTHILLS. MODELS DO INDICATE SOME LIGHT QPF IN AND NEAR FOOTHILLS
DURING THE AFTERNOON WHEN THE UPSLOPE FLOW OCCURS AND LIFT IS
OVERHEAD. MODEL CONCENSUS SHOWING SNOW AMOUNTS TO BE LESS THAN AN
INCH AND CONFINED TO FOOTHILL AREAS. GFS CONTINUES TO BE
AGRESSIVE WITH THE QPF AND SNOW AMOUNTS. WILL CONTINUE WITH THE
CHANCE POPS FOR THE AFTERNOON MOST AREAS...WITH LIKELY POPS FOR
THE FOOTHILLS. TEMPERATURES TO BE COOLER WITH HIGHS IN THE LOWER
TO MID 30S ACROSS THE PLAINS.

LONG TERM...NORTHWEST FLOW ALOFT WILL PREVAIL THURSDAY NIGHT AND
FRIDAY WHILE NORTHERLY FLOW EXISTS AT THE LOWER LEVELS.
MOISTURE...LIFT AND INSTABILITY WILL BE LIMITED...BUT ENOUGH WILL
BE PRESENT FOR OCCASIONAL LIGHT SNOW. A WEAK SHORT WILL MOVE
ACROSS THE STATE FRIDAY. IN ADDITION...THE FRONT LEFT QUADRANT OF
THE JET WILL BE OVER NORTHEAST COLORADO FRIDAY. THESE FEATURES
WILL PROVIDE THE LIFT FOR THE LIGHT SNOW. SNOW WILL COME TO END BY
FRIDAY EVENING...IF NOT SOONER AS DRIER AIR SHIFTS OVER THE STATE.

UPPER LEVEL RIDGE WILL MOVE OVER COLORADO SATURDAY. AN UPPER LEVEL
TROUGH WILL DROP INTO THE NORTHERN ROCKIES SUNDAY CAUSING FLOW ALOFT
TO BECOME WESTERLY ON SUNDAY. THIS WILL RESULT IN MILD AND DRY
CONDITIONS FOR THE WEEKEND WITH HIGHS IN THE 50S ACROSS NORTHEAST
COLORADO.

FOR SUNDAY NIGHT AND MONDAY...THE SHORT WAVE TROUGH OVER THE
NORTHERN ROCKIES MAY BRING THE AREA A ROUND OF SNOW AS IT PROGRESSES
EAST. THE GFS BRINGS A PIECE OF ENERGY THROUGH UTAH AND THEN DROPS
IT SOUTHEAST INTO NEW MEXICO. THE ECMWF KEEPS THIS SYSTEM NORTH OF
COLORADO WHICH WOULD RESULT IN DRY CONDITIONS. THE CMC IS SIMILAR TO
THE ECMWF SO WILL KEEP POPS ON THE LOW END FOR THIS SYSTEM. STILL
EXPECT A COLD FRONT AND COOLER AIR TO PUSH THROUGH COLORADO IF THIS
SYSTEMS STAYS NORTH OF THE STATE.

UPPER LEVEL RIDGE WILL QUICKLY MOVE ACROSS THE STATE MONDAY NIGHT
AND BY TUESDAY A SOUTHWEST FLOW ALOFT WILL PREVAIL AS A LARGE TROUGH
CRASHES ONTO THE WEST COAST. THIS SYSTEM WILL SLOWLY MOVE EASTWARD
WEDNESDAY. EXPECT MILD AND DRY CONDITIONS TO PREVAIL WEDNESDAY AHEAD
OF THIS SYSTEM. MAY BE ENOUGH MOISTURE AHEAD OF IT TO PRODUCE LIGHT
MOUNTAIN SNOW. LOOKING BEYOND THE FORECAST TIME FRAME...THE PAST TWO
RUNS OF THE ECMWF SHOW THIS TROUGH MOVING ALONG THE COLORADO/NEW
MEXICO BORDER. IF THIS TYPE OF PATTERN PREVAILS...EASTERN COLORADO
COULD SEE A GOOD SHOT OF SNOW.

AVIATION...WEST TO NORTHWEST WINDS HAVE PUSHED ACROSS THE AREA
AIRPORTS DURING THE AFTERNOON...WITH GUSTS AROUND 35 KTS AT APA
AND BJC. WINDS SHOWING MORE OF A WESTERLY COMPONENT IN THE PAST
HOUR. MODELS SHOW WINDS WEAKENING BY 01Z AND BECOMING MORE
SOUTHWEST AS DRAINAGE FLOW DEVELOPS. MID AND HIGH LEVEL LEVEL
MOISTURE TO INCREASE OVERNIGHT...CEILINGS TO REMAIN ABOVE 10000
FEET. ON THURSDAY...FRONT TO MOVE ACROSS THE AREA AROUND 15Z WITH
WINDS SHIFTING TO THE NORTH. COULD SEE SOME GUSTS TO 30 KTS.
CEILINGS EXPECTED TO LOWER TO AROUND 6000 FEET AGL BY 18Z. A FEW
SNOW SHOWERS COULD DEVELOP DURING THE MORNING...MAINLY WESTERN
SUBURBS. NORTHEAST WINDS DEVELOP AFTER 18Z WITH MVFR CEILINGS
POSSIBLE. THERE WILL BE A CHANCE OF LIGHT SNOW DURING THE
AFTERNOON...FOR NOW WILL WILL MAINTAIN A PROB30. ANY ACCUMULATIONS
SHOULD BE LESS THAN AN INCH.

.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM...BARJENBRUCH
LONG TERM....MEIER
AVIATION...BARJENBRUCH

AREA FORECAST DISCUSSION

NWS DENVER/BOULDER CO

1004 AM MST TUE FEB 12 2013

.UPDATE...SLOWER TEMPERATURE RECOVERY IN ZONES 30 AND 32 THIS
MORNING...SO HAVE LOWERED THE FCST HIGH TEMPERATURES IN THOSE AREA
TODAY...OTHERWISE THE REST OF THE FCST ON TRACK.

.AVIATION...NO SIGNIFICANT CHANGES PLANNED IN THE UPCOMING
TAFS...FCST ON TRACK.

.PREV DISCUSSION... /ISSUED 246 AM MST TUE FEB 12 2013/

SHORT TERM...THE UPPER LEVEL TROUGH WILL MOVE SE OF THE AREA
TODAY WITH THE FLOW ALOFT BECOMING MORE NLY AND THEN NNWLY
TONIGHT. CROSS-SECTIONS SHOW SOME INCREASE IN MOISTURE OVER THE
NRN MTNS BY TONIGHT HOWEVER WITH POOR LAPSE RATES ANY SNOW SHOULD
BE VERY LIGHT AND CONFINED MAINLY TO ZN 31. OTHERWISE WILL KEEP
THE REST OF THE RGN DRY THRU TONIGHT. AS FOR TEMPS 850-700 MB
READINGS ONLY RISE A FEW DGREES TODAY SO WILL KEEP HIGHS IN THE
UPPER 30S TO NEAR 40 ACROSS MOST OF NERN CO EXCEPT OVER THE FAR
NERN CORNER WHERE LINGERING SNOW COVER MAY KEEP HIGHS IN THE LOWER
30S.

LONG TERM...MODELS HAVE FAIRLY WEAK NORTHWESTERLY FLOW ALOFT ON
WEDNESDAY. IT INCREASES WEDNESDAY NIGHT AND BECOMES MORE WESTERLY.
ON THURSDAY...A MEAN UPPER TROUGH CONTINUES DEVELOPING OVER
EASTERN NORTH AMERICA WITH STRONG NORTHWESTERLY FLOW ON IT`S
BACKSIDE RIGHT OVER COLORADO. THERE IS AN UPPER TROUGH WITH FAILRY
DECENT SYNOPTIC SCALE ENERGY EMBEDDED IN THE FLOW ON THURSDAY INTO
THURSDAY NIGHT. THIS USHERS IN A COLD FRONT WITH UPSLOPE BEHIND IT
FOR THE PLAINS AND FOOTHILLS ON THURSDAY. THE UPSLOPE FLOW
CONTINUES MUCH OF THURSDAY NIGHT. THE LOW LEVEL FLOW ON WEDNESDAY
AND WEDNESDAY NIGHT IS MAINLY DOWNSLOPING. FOR MOISTURE...MODELS
SHOW SOME IN THE MOUTNIANS...AND A BIT OVER THE PLAINS. MOISTURE
INCREASES OVER ALL THE CWA WEDNESDAY NIGHT. BY THURSDAY IT IS
PRETTY DEEP OVER ALL THE CWA...THIS CONTINUES THURSDAY NIGHT. THE
QPF FIELDS HAVE A TAD OF MEASURABLE SNOWFALL OVER THE MOUNTAINS
WEDNESDAY AND WEDNESDAY NIGHT. ON THURSDAY
..THE AMOUNTS IN THE MOUNTAINS INCREASE A BIT...AND THERE IS A
TAD OVER THE MOST OF THE PLAINS BY AFTERNOON. THERE ARE HIGHER
AMOUNTS THURSDAY NIGHT OVER THE FOOTHILLS AND IMMEDIATE PLAINS.
THERE IS A BIT OVER MOST AREAS AFTER MIDNIGHT THURSDAY NIGHT...
EXCEPT FOR THE NORTHEAST CORNER. FOR POPS...THERE IS ENOUGH
MOISTURE AND OROGRAPHIC HELP TO KEEP "CHANCE"S OF SNOW IN THE HIGH
MOUNTAINS WEDNESDAY INTO WEDNESDAY EVENING...THEN "LIKELY"S INTO
THURSDAY EVENING. BY LATER THURSDAY INTO THURSDAY NIGHT...THE
UPSLOPE BEHIND THE COLD FRONT...ALONG WITH A FAIRLY DECENT BRIEF
SHOT OF SYNOPTIC SCALE ENERGY...AND MOISTURE...WILL GO WITH
"CHANCE"S OVER MOST OF THE PLAINS AS WELL. FOR TEMPERATURES...
WEDNESDAY`S HIGHS LOOK TO BE 3.0-4.5 C WARMER THAN TODAY`S.
THURSDAY`S WILL BE 2-5 C COLDER THAN WEDNESDAY`S. THE MOS GUIDANCE
WEDNESDAY AND THURSDAY HIGH TEMPERATURES FOR DENVER DIFFER
CONSIDERABLY BETWEEN THE GFS AND NAM. THE GFS IS 12 DEGREES F
WARMER BOTH DAYS. FOR THE LATER DAYS...FRIDAY THROUGH MONDAY
..MODELS HAVE STRONG NORTHERLY FLOW ALOFT FOR THE CWA FRIDAY INTO
EARLY SATURDAY. BY SATURDAY MIDDAY INTO THE EVENING AN UPPER
RIDGE MOVES ACROSS THE FORECAST AREA WITH WEAK ZONAL FLOW. THE
ZONAL FLOW INCREASES IN SPEED ON SUNDAY...THEN THE NEXT UPPER
TROUGH IS PROGGED TO MOVE ACROSS COLORADO ON MONDAY. THE MOISTURE
DECREASES RAPIDLY ON FRIDAY. BOTH THE GFS AND ECMWF SHOW A DRY
WEEKEND WITH WARMING TEMPERATURES. BOTH ALSO SHOW PRETTY DEEP
MOISTURE...EVEN UPSLOPE FOR THE PLAINS WITH THE MONDAY SYSTEM.

AVIATION...WINDS ARE DRAINAGE EARLY THIS MORNING. LATEST HRRR AND
RAP SHOW WINDS BECOMING MORE NNW BY 19Z AND THEN MORE NNE BY 23Z.
BY EARLY EVENING EXPECT A LIGHT ELY COMPONENT WHICH WILL GRADUALLY
BECOME DRAINAGE BY 04Z. OTHERWISE SHOULD HAVE VFR CONDITIONS TODAY
AND TONIGHT.

.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM...COOPER
LONG TERM....RJK
AVIATION...COOPER

AREA FORECAST DISCUSSION

NWS DENVER/BOULDER CO

246 AM MST TUE FEB 12 2013

.SHORT TERM...THE UPPER LEVEL TROUGH WILL MOVE SE OF THE AREA
TODAY WITH THE FLOW ALOFT BECOMING MORE NLY AND THEN NNWLY
TONIGHT. CROSS-SECTIONS SHOW SOME INCREASE IN MOISTURE OVER THE
NRN MTNS BY TONIGHT HOWEVER WITH POOR LAPSE RATES ANY SNOW SHOULD
BE VERY LIGHT AND CONFINED MAINLY TO ZN 31. OTHERWISE WILL KEEP
THE REST OF THE RGN DRY THRU TONIGHT. AS FOR TEMPS 850-700 MB
READINGS ONLY RISE A FEW DGREES TODAY SO WILL KEEP HIGHS IN THE
UPPER 30S TO NEAR 40 ACROSS MOST OF NERN CO EXCEPT OVER THE FAR
NERN CORNER WHERE LINGERING SNOW COVER MAY KEEP HIGHS IN THE LOWER
30S.

.LONG TERM...MODELS HAVE FAIRLY WEAK NORTHWESTERLY FLOW ALOFT ON
WEDNESDAY. IT INCREASES WEDNESDAY NIGHT AND BECOMES MORE WESTERLY.
ON THURSDAY...A MEAN UPPER TROUGH CONTINUES DEVELOPING OVER
EASTERN NORTH AMERICA WITH STRONG NORTHWESTERLY FLOW ON IT`S
BACKSIDE RIGHT OVER COLORADO. THERE IS AN UPPER TROUGH WITH FAILRY
DECENT SYNOPTIC SCALE ENERGY EMBEDDED IN THE FLOW ON THURSDAY INTO
THURSDAY NIGHT. THIS USHERS IN A COLD FRONT WITH UPSLOPE BEHIND IT
FOR THE PLAINS AND FOOTHILLS ON THURSDAY. THE UPSLOPE FLOW
CONTINUES MUCH OF THURSDAY NIGHT. THE LOW LEVEL FLOW ON WEDNESDAY
AND WEDNESDAY NIGHT IS MAINLY DOWNSLOPING. FOR MOISTURE...MODELS
SHOW SOME IN THE MOUTNIANS...AND A BIT OVER THE PLAINS. MOISTURE
INCREASES OVER ALL THE CWA WEDNESDAY NIGHT. BY THURSDAY IT IS
PRETTY DEEP OVER ALL THE CWA...THIS CONTINUES THURSDAY NIGHT. THE
QPF FIELDS HAVE A TAD OF MEASURABLE SNOWFALL OVER THE MOUNTAINS
WEDNESDAY AND WEDNESDAY NIGHT. ON THURSDAY
...THE AMOUNTS IN THE MOUNTAINS INCREASE A BIT...AND THERE IS A
TAD OVER THE MOST OF THE PLAINS BY AFTERNOON. THERE ARE HIGHER
AMOUNTS THURSDAY NIGHT OVER THE FOOTHILLS AND IMMEDIATE PLAINS.
THERE IS A BIT OVER MOST AREAS AFTER MIDNIGHT THURSDAY NIGHT...
EXCEPT FOR THE NORTHEAST CORNER. FOR POPS...THERE IS ENOUGH
MOISTURE AND OROGRAPHIC HELP TO KEEP "CHANCE"S OF SNOW IN THE HIGH
MOUNTAINS WEDNESDAY INTO WEDNESDAY EVENING...THEN "LIKELY"S INTO
THURSDAY EVENING. BY LATER THURSDAY INTO THURSDAY NIGHT...THE
UPSLOPE BEHIND THE COLD FRONT...ALONG WITH A FAIRLY DECENT BRIEF
SHOT OF SYNOPTIC SCALE ENERGY...AND MOISTURE...WILL GO WITH
"CHANCE"S OVER MOST OF THE PLAINS AS WELL. FOR TEMPERATURES...
WEDNESDAY`S HIGHS LOOK TO BE 3.0-4.5 C WARMER THAN TODAY`S.
THURSDAY`S WILL BE 2-5 C COLDER THAN WEDNESDAY`S. THE MOS GUIDANCE
WEDNESDAY AND THURSDAY HIGH TEMPERATURES FOR DENVER DIFFER
CONSIDERABLY BETWEEN THE GFS AND NAM. THE GFS IS 12 DEGREES F
WARMER BOTH DAYS. FOR THE LATER DAYS...FRIDAY THROUGH MONDAY
...MODELS HAVE STRONG NORTHERLY FLOW ALOFT FOR THE CWA FRIDAY INTO
EARLY SATURDAY. BY SATURDAY MIDDAY INTO THE EVENING AN UPPER
RIDGE MOVES ACROSS THE FORECAST AREA WITH WEAK ZONAL FLOW. THE
ZONAL FLOW INCREASES IN SPEED ON SUNDAY...THEN THE NEXT UPPER
TROUGH IS PROGGED TO MOVE ACROSS COLORADO ON MONDAY. THE MOISTURE
DECREASES RAPIDLY ON FRIDAY. BOTH THE GFS AND ECMWF SHOW A DRY
WEEKEND WITH WARMING TEMPERATURES. BOTH ALSO SHOW PRETTY DEEP
MOISTURE...EVEN UPSLOPE FOR THE PLAINS WITH THE MONDAY SYSTEM.

.AVIATION...WINDS ARE DRAINAGE EARLY THIS MORNING. LATEST HRRR AND
RAP SHOW WINDS BECOMING MORE NNW BY 19Z AND THEN MORE NNE BY 23Z.
BY EARLY EVENING EXPECT A LIGHT ELY COMPONENT WHICH WILL GRADUALLY
BECOME DRAINAGE BY 04Z. OTHERWISE SHOULD HAVE VFR CONDITIONS TODAY
AND TONIGHT.

.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM...RPK
LONG TERM....RJK
AVIATION...RPK

AREA FORECAST DISCUSSION

NWS TALLAHASSEE FL

330 PM EST Tue Feb 12 2013

...SEVERE WEATHER AND ADDITIONAL FLOODING POSSIBLE THIS EVENING INTO
MIDDAY WEDNESDAY...

.NEAR TERM [through Tonight]...
A surface low was continuing to develop along the Gulf coast in the
mid-afternoon, and at 20 UTC was centered somewhere just north of
Lake Charles, Louisiana (SW LA). The stalled front that was draped
to the east from this low was beginning to return north as a warm
front. The warm front had only penetrated a minor distance inland in
some spots, and stretched from the low, to New Orleans, to Mexico
Beach, to St. Mark`s, to Madison FL. South of this boundary, partial
clearing was occurring with temperatures reaching into the 70s and
dewpoints quickly increasing into the upper 60s to around 70. This
has allowed MLCAPE to slowly build along and just south of the warm
front. However, destabilization will probably occur more in earnest
this evening when stronger mid-upper level height falls spread east
with the ejecting wave aloft, and a plume of steeper mid-level lapse
rates advects east along the Gulf coast.

Thunderstorms were already developing in the broad WAA regime from C
MS to S GA. The nose of the strongest 0-2km moisture transport (and
band of strongest low-level theta-e advection) will be near the
track of the surface low, which at the moment appears as though it
will be just to the northwest of our area. Therefore, the best large
scale forcing for rain should be located just outside our forecast
area, which is not bad news given the recent heavy rainfall. That
being said, the highest probability of rain still looks to be
closest to those forcing mechanisms in the northwest half of our
area, which is also the area that received the heavy rain yesterday.
Therefore, we will maintain the Flash Flood Watch overnight given
the coincidence of highest PoPs and high soil moisture / low FFG.

The isolated severe weather threat appears to still be on track. As
the surface low develops ENE this evening, the surface warm front
should shift north through the area drawing an unstable boundary
layer air mass in. Model mean MLCAPE from the NAM, GFS, and ECMWF
looks to be around 500 j/kg with about 60-70 knots of deep layer
shear. This falls within a favorable parameter space for low-topped
supercells and severe weather in our area, but there remain some
uncertainties. Convection-allowing model (CAM) guidance has not
shown very vigorous updrafts in any forecast thunderstorms in our
area. Therefore, there is likely some sort of limiting factor -
probably related to boundary layer stability - that will ultimately
decide how intense the overnight convection is. The 00 UTC TAE
sounding may reveal some important clues about any low-level stable
layers or inversions that could inhibit the severe threat. Although
a few scattered supercells are possible in the warm sector, we
expect a trend towards a squall line or line segments along the
trailing cold front with time tonight. Given an overall favorable
juxtaposition of shear and instability, severe storms are certainly
possible, but we expect impacts to be isolated and confined to only
the strongest cells.

As the warm front lifts north this evening and a warm, moist air
mass advects into our area (as well as widespread cloud cover and
occasional rain), we should see a mild night. Temperatures are
expected to follow a non-diurnal trend and remain nearly steady.
LAMP and RAP guidance was used to portray hourly temp trends.

.SHORT TERM [Wednesday Through Friday]...
The severe weather threat will end from west to east ahead of the
cold front that will push through Wednesday and Wednesday night. The
severe weather threat will shift eastward encompassing most of our
Georgia zones and the Florida Big Bend. The main concern will
continue to be the potential for damaging thunderstorm winds
although an isolated tornado is also possible. We will also be
monitoring rainfall very closely as the ground is already or near
saturated across SE AL and our northern and westernmost GA zones.
Also, there is a potential for another 1 to 2 inches of rain in
these areas and a Flood Watch will continue to be in effect. In the
wake of the front, high pressure and a much drier airmass filter
into the region. Max temps will be near seasonal levels with lows at
or just below normal.

.LONG TERM [Friday Night through next Tuesday]...
A broad upper trough will amplify over the eastern third of the
CONUS Saturday with a dry cold front passing through the local
region by late in the day. The upper flow becomes nearly zonal on
Sunday with a cold and dry airmass settling in over the area.
Surface high pressure is forecast to be centered across the Florida
panhandle Sunday before sliding east and off the southeast U.S.
coast Monday. Another upper level trough digs through the nation`s
midsection Monday with induced ridging across the local area. The
trough deamplifies as in moves through the Lower Mississippi Valley
Tuesday but showers and thunderstorms are forecast to spread across
the Tri-state region ahead of the cold front. Confidence is low on
the timing of this system so will keep PoPs in the chance category.
Colder than normal temps are expected over the weekend, especially
Sunday with lows around 30 degrees and highs only in the mid 50s for
most inland areas. Another light freeze is possible Monday morning
followed by a gradual warming trend.

.AVIATION [through 18z Tuesday]...
Although some brief MVFR may be possible at a few of the terminals
where clouds temporarily thin this afternoon, widespread IFR is
expected to prevail through the night and into early tomorrow
morning. Occasional LIFR will be possible - both in low stratus and
in any of the stronger thunderstorms that may occur overnight. Some
of the storms may produce gusty winds, but for now limited gusts in
the "TEMPO" groups to between 20 and 30 knots. Timing for that TEMPO
group was based on a model consensus.

.MARINE...
A surface low will track from the central Gulf coast this evening to
near the Delmarva Peninsula by Wednesday evening and drag a
southwest extending cold front across the local waters. Onshore
winds will increase from west to east to advisory levels tonight
ahead of the front. Winds will swing around to become offshore
Wednesday afternoon and evening in the wake of the front with winds
and seas gradually dropping below headline criteria. Light winds and
low seas are expected through the reminder of the work week as high
pressure builds over the waters. Winds and seas elevate to advisory
levels once again in the wake of an arctic cold front over the
weekend.

.FIRE WEATHER...
Wet conditions are expected through Wednesday. Drier air will move
in for Thursday and Friday with minimum RH values near or just below
35 percent across portions of inland northwest Florida. However,
with wet soils overall, it seems unlikely that red flag conditions
will be reached.

.HYDROLOGY...
After a long stretch of quiet river conditions, things have
certainly changed in a hurry. Extremely heavy rains across parts of
Southeast Alabama Sunday night and Monday (radar estimates of over a
foot in Geneva County) caused sharp rises along parts of the
Choctawhatchee River, which is forecast to crest in the minor flood
category at Geneva and Caryville and the moderate flood category at
Bruce. Some of this heavy rain extended into Georgia as well, and
downstream rises are also expected along the Apalachicola and
Chipola Rivers. Currently the Apalachicola River at Blountstown is
expected to crest in the minor flood category with the Chipola River
at Marianna and Altha rising to action stage by late Friday into
Saturday. The Kinchafoonee Creek is also expected to rise into the
minor flood category in Lee county east of Dawson and remain just
below minor flood stage up at Preston.

An additional couple of inches of rain are expected across portions
of southeast Alabama and southwest Georgia through Wednesday, so
some additional modifications are certainly possible depending upon
how much rain actually falls.

.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 67 69 44 67 37 / 80 90 20 0 0
Panama City 66 69 45 64 44 / 70 80 10 0 0
Dothan 62 65 40 63 41 / 90 70 10 0 0
Albany 62 69 40 64 38 / 90 80 10 0 0
Valdosta 65 69 46 65 38 / 60 90 20 0 0
Cross City 64 74 48 67 39 / 30 80 30 0 0
Apalachicola 67 71 46 63 43 / 60 90 20 0 0

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...FLASH FLOOD WATCH through Wednesday morning for Central Walton-
Holmes-Inland Walton-Jackson-Washington.
GA...FLASH FLOOD WATCH through Wednesday morning for Baker-Ben Hill-
Calhoun-Clay-Dougherty-Early-Irwin-Lee-Miller-Quitman-
Randolph-Seminole-Terrell-Tift-Turner-Worth.
AL...FLASH FLOOD WATCH through Wednesday morning for Coffee-Dale-
Geneva-Henry-Houston.
GM...None.

NEAR TERM/AVIATION...Lamers
SHORT TERM/MARINE...Barry
FIRE WEATHER/HYDROLOGY...DVD
LONG TERM...Barry

AREA FORECAST DISCUSSION...UPDATED

NWS TAMPA BAY RUSKIN FL

430 AM EST TUE FEB 12 2013

.SYNOPSIS...
09Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS OUR REGION ON THE NORTHERN
PERIPHERY OF A BROAD EAST-WEST ORIENTED UPPER RIDGE EXTENDING FROM
THE SOUTHERN GULF OF MEXICO TO THE FL STRAITS AND BAHAMAS. THIS
RIDGE IS ALL THAT IS LEFT OF A ONCE MORE PROMINENT RIDGE ALONG THE
EASTERN SEABOARD WHICH HAS BEEN BROKEN DOWN OVER THE PAST 24 HOURS
BY STRONG SHORTWAVE ENERGY EJECTING EASTWARD OVER THE NORTHEAST
STATES. THE OTHER FEATURE WITHIN THE LARGE SCALE FLOW PATTERN OF
INTEREST IS A BROAD TROUGH IN PLACE OVER THE CENTRAL PLAINS AND
WELL-ORGANIZED IMPULSE/SHORTWAVE EMBEDDED AT ITS BASE. THIS ENERGY
WILL QUICKLY MOVE EASTWARD THROUGH THE LOWER MS AND SOUTHEASTERN
STATES DURING THE NEXT 24-36 HOURS. 00Z KTBW SOUNDING SHOWED THE
RESIDUAL INFLUENCE OF THE UPPER RIDGE TO OUR SOUTH WITH A SUBSIDENCE
INVERSION AROUND 800MB. THIS DEEP LAYER SUPPRESSION WILL ONCE AGAIN
HELP TO KEEP OUR FORECAST GENERALLY DRY AND WARM TODAY.

AT THE SURFACE...RIDGE AXIS EXTENDS FROM THE BAHAMAS WESTWARD ACROSS
THE FL PENINSULA TO THE FAR EASTERN GULF. THIS FEATURE LIES SOUTH OF
A NOW QUASI-STATIONARY FRONTAL BOUNDARY ALIGNED FROM OFF THE AL/MS
COAST TO APALACHEE BAY...AND THEN NORTHEAST TOWARD THE GA COAST.
DEEP MOISTURE IS MOVING NORTHWARD AROUND THE SURFACE RIDGE AXIS AND
RESULTING IN AREAS OF DENSE SEA-FOG OVER PORTIONS OF APALACHEE BAY.
VERY DIFFICULT TO DETERMINE JUST HOW FAR EAST THIS FOG EXTENDS...AND
WOULD NOT BE SURPRISED TO SEE SOME DENSE FOG POTENTIAL REACH THE
COASTAL WATERS OFF LEVY COUNTY THIS MORNING. FURTHER SOUTH...WINDS
ARE RATHER LIGHT UNDER THE RIDGE AND LIKELY NOT SEEING MUCH IN THE
WAY OF SEA-FOG. OBSERVATIONS SHOW RATHER THAT WE ARE SEEING AREAS OF
SHALLOW RADIATION FOG OVER THE LAND AREAS OF THE NATURE COAST. THIS
LAND BASED FOG IS BECOMING MORE WIDESPREAD WITH TIME AND A DENSE FOG
ADVISORY WILL BE ISSUED FOR INLAND HILLSBOROUGH/EASTERN POLK
COUNTIES NORTHWARD THROUGH THE NATURE COAST ZONES. THE SEA-FOG JUST
TO OUR WEST MAY BECOME MORE OF AN ISSUE TONIGHT (TUESDAY NIGHT) AS
FLOW VEERS MORE SOUTH AND EVEN SOUTHWEST WITH TIME.

.SHORT TERM (TODAY THROUGH THURSDAY)...
TODAY/TONIGHT...ANOTHER WARM AND GENERALLY DRY DAY ON TAP FOR THE
FLORIDA WEST COAST UNDERNEATH THE RESIDUAL UPPER RIDGING. STALLED
FRONTAL BOUNDARY NEAR OR JUST SOUTH OF THE I-10 CORRIDOR EARLY
THIS MORNING WILL BEGIN LIFTING SLOWLY NORTHWARD TODAY IN RESPONSE
TO BOTH DIURNAL HEATING AND LOW ORGANIZATION OVER SOUTHERN LA. NOT
OUT OF THE QUESTION THAT WE COULD SEE A FEW ISOLATED INSTABILITY
SHOWERS ACROSS THE NATURE COAST IN CLOSEST PROXIMITY TO THE
BOUNDARY...HOWEVER ANY COVERAGE WILL BE LOW AND OF MINIMAL IMPACT.
ONCE AGAIN...GOOD DIURNAL MIXING ACTING ON A WARM LOW LEVEL COLUMN
(850MB TEMPS 12-14C) WILL ALLOW TEMPS TO REACH THE UPPER 70S TO NEAR
80 NORTH AND THE LOWER 80S SOUTH. A FEW WARMER SPOTS WILL LIKELY SEE
MID 80S SOUTH OF I-4. THE STRONG INLAND HEATING SHOULD FORCE AN
ONSHORE WIND COMPONENT AT THE COAST THIS AFTERNOON AND KEEP TEMPS
DOWN SEVERAL DEGREES AT THE BEACHES. UPPER LEVEL ENERGY BEGINS TO
QUICKLY MOVE ALONG THE NORTHERN GULF COAST TONIGHT. SURFACE LOW
LIFTS NORTH INTO AL WITH ITS TRAILING COLD FRONT PROGRESSING EAST TO
THE FL PANHANDLE AND ADJACENT GULF WATERS. MAIN SYNOPTIC LIFT AND
FRONTAL FORCING SHOULD HOLD TO OUR WEST MOST...IF NOT ALL OF THE
NIGHT AND WILL KEEP RAIN CHANCES LOW. EVEN HIGHER DEWPOINT AIR
STREAMING NORTHWARD WITHIN THE THERMAL RIDGE AHEAD OF THE FRONT WILL
GIVE US A BETTER CHANCE OF SEA-FOG DEVELOPING ALONG THE NATURE COAST
AND DOWN AS FAR SOUTH AS PINELLAS COUNTY. THIS POTENTIAL WILL NEED
TO BE MONITORED CLOSELY THROUGH THE DAY.

WEDNESDAY...SHORT WAVE ENERGY PASSES TO OUR NORTH...BUT IS CLOSE
ENOUGH FOR A SWATH OF DECENT SYNOPTIC SUPPORT/QG FORCING TO SPREAD
ACROSS THE AREA...ESPECIALLY FROM TAMPA BAY NORTHWARD. THIS ALONG
WITH THE FRONTAL FOCUS SHOULD BE ENOUGH TO SUPPORT A BAND OF SHOWERS
AND STORMS ACROSS THE CENTRAL AND NORTHERN PORTIONS OF THE AREA. THE
TREND HAS BEEN TO SLOW THE ADVANCE OF THIS BAND WITH TIME...BUT
OFTEN NWP GUIDANCE IS TOO SLOW WITH THESE TYPES OF FEATURES TO START
WITH. WILL NOT GET TO DETAILED WITH THE TIMING AT THIS POINT...BUT
WILL KEEP RAIN CHANCES HIGH FROM THE I-4 CORRIDOR NORTHWARD. FURTHER
SOUTH...THE LATER ARRIVAL OF THE FRONTAL FOCUS WILL NOT COINCIDE
WITH THE BEST KINEMATICS...AND WE ARE LIKELY TO SEE A MORE BROKEN
BAND OF SHOWERS/ISOLATED STORMS INTO THE SOUTHERN ZONES DURING THE
LATE AFTERNOON OR EVENING HOURS. WILL BE WATCHING FOR THE POTENTIAL
OF A FEW STRONGER STORMS ON WEDNESDAY...ESPECIALLY NORTH OF TAMPA
BAY. DEEP LAYER SHEAR IS NOT EXCEPTIONALLY HIGH...BUT IS SUFFICIENT
TO SUPPORT ORGANIZED CONVECTION AND A FEW ENHANCED UPDRAFTS. THE
QUESTION WILL BE WHETHER THE FLOW OFF THE COOLER SHELF WATERS
PREVENTS ANY STORMS FROM BEING SURFACE BASED.

WEDNESDAY NIGHT THROUGH THURSDAY...FRONT LAYS OUT OVER FAR SOUTHERN
FL WEDNESDAY NIGHT...AND EXPECT TO SEE A BRIEF PERIOD WITH DRY
CONDITIONS ACROSS THE ENTIRE AREA. THIS DOES NOT LOOK TO LAST LONG
THOUGH...AS THE NEXT IMPULSE QUICKLY APPROACHES AND PROVIDES MORE
DEEP LAYER LIFT. BY THURSDAY MORNING WE WILL ALSO FIND OUR AREA
WITHIN THE FAVORABLE RIGHT ENTRANCE REGION OF A 140-150KT UPPER
JET. GFS/ECMWF BOTH SHOW A SWATH OF GOOD UPPER LEVEL DIVERGENCE
WITHIN THIS ZONE WHICH WILL ACT TO ENHANCE THE VERTICAL LIFT. TRICKY
TO PIN-POINT WHERE ALL THE INGREDIENTS WILL COME TOGETHER BEST...BUT
USING DEEP LAYER MOISTURE...IT WOULD APPEAR THE AREAS SOUTH OF TAMPA
BAY WOULD SEE THE BEST CHANCES FOR SHOWERS/AREAS OF RAIN DEVELOPING
THURSDAY. WILL GO WITH THIS SCENARIO FOR NOW...AND KEEP ANY SHOWERS
MORE SCATTERED UP ACROSS THE I-4 CORRIDOR AND THEN ISOLATED TOWARD
THE NORTHERN NATURE COAST ZONES.

.LONG TERM (THURSDAY NIGHT THROUGH NEXT MONDAY)...
ONCE AGAIN THE GFS AND ECMWF ARE SIMILAR ENOUGH THROUGH MONDAY WITH
REGARDS TO SYNOPTIC SCALE FEATURES BUT DIFFER ON SMALLER SCALE
DETAILS.

THROUGH FRIDAY NIGHT...A FRONTAL BOUNDARY WILL BE TO OUR SOUTH WITH
A SHALLOW COOL AIRMASS IN PLACE OVER THE REGION. MID-LEVEL TROUGHING
WILL REMAIN TO OUR WEST WITH SOUTHWESTERLY FLOW ALOFT. AT THE SAME
TIME WE WILL BE SOUTH OF THE STRONG JET WHICH WILL PROVIDE
ADDITIONAL LIFT FROM ABOVE. THESE FEATURES WILL COMBINE TO KEEP
PARTLY TO MOSTLY CLOUDY SKIES OVER THE REGION WITH SOME TREND TOWARD
CLEARING FROM NORTH TO SOUTH LATER FRIDAY AND FRIDAY NIGHT.
OVER-RUNNING RAINS THURSDAY NIGHT WILL ALSO SLOWLY WIND DOWN FRIDAY
AND FRIDAY NIGHT...BUT MODEL DIFFERENCES MAKE TIMING AND OVERALL
RAIN CHANCES DIFFICULT TO PIN DOWN. BEST BET FOR RAIN IN THE
EXTENDED PORTION OF THE FORECAST SHOULD COME THURSDAY NIGHT AND
MAINLY OVER OUR SOUTHERN ZONES CLOSER TO THE INITIAL FRONTAL
BOUNDARY.

THE UPPER-LEVEL TROUGH WILL SHARPEN AND DIG SOUTHWARD INTO THE
NORTHERN GULF ON SATURDAY...LOWERING HEIGHTS OVER THE REGION. THIS
SHOULD BRING AND END TO THE OVER-RUNNING RAINS BUT THE 00Z ECMWF HAS
BROUGHT SOME PRECIPITATION BACK INTO THE FORT MYERS REGION DURING
THE AFTERNOON HOURS. THE GFS IS DRY AND WILL KEEP RAIN CHANCES BELOW
20 PERCENT FOR NOW.

THE TROUGH AXIS WILL FINALLY SWING EAST OF FLORIDA SATURDAY NIGHT
WHILE A SECOND PUSH OF MUCH COOLER AND DRIER AIR MOVES IN AT THE
SURFACE. THE GFS AND ECMWF BOTH SHOW A BRIEF INTRUSION OF BELOW
FREEZING TEMPERATURES AT 850MB SATURDAY NIGHT AND SUNDAY. THE COLD
HIGH CENTER MOVES EASTWARD ACROSS THE NORTHERN GULF AND SETTLES
DIRECTLY OVER NORTH FLORIDA SUNDAY NIGHT. IF SKIES ARE CLEAR...WE
COULD BE LOOKING AT THE COLDEST NIGHT OF THE SEASON WITH
TEMPERATURES DROPPING INTO THE MIDDLE OR UPPER 20S BY MONDAY MORNING
OVER THE NATURE COAST AND NEAR-FREEZING TEMPERATURES TO THE SOUTH.
SINCE THIS IS OUT AT DAY SEVEN...WILL PLAY IT A LITTLE CONSERVATIVE
FOR NOW BUT STILL SHOW FREEZING TEMPERATURES NORTH.

.AVIATION...
FOG WILL BRING MVFR/IFR VISIBILITIES TO PGD AND IFR/LIFR
VISIBILITIES TO LAKELAND THROUGH 13 OR 14Z. OTHER TERMINALS COULD
SEE SOME BRIEF MVFR VISIBILITIES THIS MORNING THEN VFR DURING THE
AFTERNOON. FOG MAY AGAIN RESULT IN IFR CONDITIONS TONIGHT.

.MARINE...
SURFACE HIGH PRESSURE WILL SLOWLY GIVE WAY THE NEXT 24 HOURS AS A
COLD FRONT APPROACHES THE EASTERN GULF OF MEXICO FROM THE WEST. THIS
FRONT WILL SHIFT THROUGH THE FORECAST WATERS WEDNESDAY AND WEDNESDAY
EVENING WITH A WIND SHIFT TO THE NORTH IN ITS WAKE. PERIODS OF
CAUTIONARY LEVEL WINDS ARE EXPECTED TONIGHT AND WEDNESDAY ALONG
AHEAD OF THIS FRONT.

AREAS OF SEA FOG AND REDUCED VISIBILITY ARE POSSIBLE TODAY OVER THE
NORTHERN WATERS...MAINLY OFF THE COAST OF HERNANDO...CITRUS...AND
LEVY COUNTIES. THIS FOG IS EXPECTED TO BECOME MORE WIDESPREAD
TONIGHT INTO WEDNESDAY MORNING AND ALSO MAY EXPAND FURTHER SOUTH
WITH TIME. MARINERS SHOULD MONITOR CONDITIONS CLOSELY UNTIL THE
FRONT PASSES ON WEDNESDAY IN CASE MARINE DENSE FOG ADVISORIES BECOME
NECESSARY.

.FIRE WEATHER...
RELATIVE HUMIDITY WILL REMAIN ABOVE CRITICAL LEVELS THROUGH THE
MIDWEEK PERIOD AS MOISTURE CONTINUES TO MOVE NORTH AHEAD OF A COLD
FRONT. ONCE THE COLD FRONT MOVES THROUGH WEDNESDAY AND WEDNESDAY
NIGHT...SOME DRIER AIR WILL ATTEMPT TO MOVE SOUTH INTO THE NATURE
COAST ZONES...HOWEVER CRITICAL FIRE WEATHER CONDITIONS ARE NOT
EXPECTED AT THIS TIME.

.PRELIMINARY POINT TEMPS/POPS...
TPA 79 66 79 61 / 0 10 60 40
FMY 83 67 84 64 / 0 10 20 30
GIF 83 64 83 58 / 10 10 50 40
SRQ 77 67 79 62 / 10 10 50 40
BKV 82 63 80 56 / 0 10 70 40
SPG 79 67 79 63 / 10 10 60 40

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH THURSDAY EVENING FOR
CHARLOTTE-LEE.

BEACH HAZARDS STATEMENT THROUGH WEDNESDAY EVENING FOR
SARASOTA.

GULF WATERS...NONE.

SYNOPSIS/SHORT TERM/MARINE/FIRE WEATHER...MROCZKA
LONG TERM/AVIATION...JILLSON

AREA FORECAST DISCUSSION

NWS TALLAHASSEE FL

1120 PM EST Mon Feb 11 2013

...UPDATED FOR FOG...

.NEAR TERM [through Tonight]...

Latest satellite and local obs shows fog developing across region
with the focus along and east of the frontal boundary, that is the
SE third of our area. lamp, SREF and other guidance imply areas t
widespread fog will develop rest of overnight. updated grids rest
of tonight to insert patch dens west or and areas of dense fog
along and east of frontal boundary. a dense fog advisory may be
necessary soon.

Convection continues to wind down during the late evening hours.
Meanwhile, a large area of moderate rain with embedded
thunderstorms was developing from C/S AL west into LA. This area
of rain was roughly on the broad nose of a newly developed low-
level moisture transport maximum - currently focused into coastal
Louisiana and Mississippi. The RAP projects that the ribbon of
strongest moisture transport should develop northeast into our
area by around 03z, with roughly similar PWAT values. Therefore,
we anticipate that rain - heavy at times, with embedded storms -
will redevelop across much of the NW half to two-thirds of our
area this evening.

.SHORT TERM [Tuesday through Wednesday Night]...
A more pronounced mid-upper level trough - currently evident on
water vapor loops over the Desert Southwest - will dig ESE into
the Southern Plains on Tuesday, and then eject into the Ohio River
Valley on Tuesday Night. This evolution will allow for surface
cyclogenesis on Tuesday near coastal Louisiana, with the low
passing northwest of our area through central Alabama on Tuesday
Night. With stronger height falls and QG convergence to the west
of us on Tuesday, we should see a lull in the rain during the day.
The better chances of rain are expected to arrive from Tuesday
Night into Wednesday with the main trailing cold front. Portions
of our area are in a "Slight Risk" on the latest SPC SWODY2
outlook for the possibility of storms moving in later in the
period (Tuesday evening or overnight). The local confidence grids
and the SPC SREF calibrated severe probabilities both indicate
about a 15-20% chance of severe storms in the western two-thirds
of our area in the 12-hour period centered on 12z Wednesday. CIPS
analogs from SLU show about 5-10% probabilities, with about half
the analogs with at least one severe weather report in our area.
The combination of all of these probabilistic outlooks are in
fairly good agreement, and are consistent with some isolated
severe storms late Tuesday Night. Mean model MLCAPE on the ECMWF,
GFS, and CAM models looks to be around 500 j/kg overnight with
about 60-70 knots of deep layer shear.

.LONG TERM [Thursday through Monday]...
Quieter weather arrives with surface high pressure and increasing
subsidence in the wake of the cold front on Thursday and Friday.
An amplifying longwave trough in the eastern CONUS on the weekend
may provide a shot of colder air, although details still vary from
model-to-model, and run-to-run.

.Aviation...[Through 00z Wednesday]
Prevailing IFR/LIFR conditions through daybreak followed by
prevailing MVFR/IFR cigs/vsby for the remainder of the TAF
period as an unsettled weather pattern remains across the Tri-state
region. Scattered to numerous showers and thunderstorms will be
common.

.MARINE...
Unsettled weather pattern will remain through mid week with a chance
of showers and thunderstorms, as well as breezy southerly winds each
period. Winds will increase a bit ahead of a cold front Tuesday
night and Wednesday, before switching to offshore on Thursday and
diminishing into the weekend.

.FIRE WEATHER...
An unsettled weather pattern with scattered to numerous showers and
thunderstorms will continue at least through Wednesday. Drier
conditions will return late in the week but we see no fire weather
concerns at this time.

.HYDROLOGY...
Significant rainfall has largely ended for this afternoon across
the region. Observed and radar estimated rainfall totals show
significant storm totals of 10 to 15 inches from Central Geneva
County eastward through much of Houston County. Lower values of 5
to 8 inches were observed further east into parts of Southwestern
Georgia in the last 24 hours. Given recent rains across Southeast
Alabama and Southwest Georgia, little additional rainfall will be
needed to cause flash flooding in these areas and a flash flood
watch remains in effect through Tuesday morning.

Higher end rainfall totals are expected once again on Tuesday
evening through Wednesday across the area. Given the uncertainty
with the exact placement of the heaviest rainfall with this next
system, will delay any flash flood watches on this package. However,
it is expected that additional flash flood watches will be needed
across the area Tuesday night into Wednesday.

Riverine flooding will become an increasing concern as local runoff
is routed downstream from creeks and streams in Southeast Alabama.
River gages north of a line from Enterprise Alabama to Abbeville
Alabama appear to have crested with routed flow from these sites
progressing down into the Choctawhatchee River system. Rises to near
or in excess of minor flood stage is anticipated along the
Choctawhatchee River from Geneva southward to Caryville into Friday
given the current water already in the system. Flooding may also
continue downriver toward Bruce but this would not occur until
Saturday under present conditions. Rises on the Chipola River to
minor flood stage can also be expected later this week as runoff
progresses downstream from Southern Alabama.

Additional riverine flooding, both in magnitude and coverage, will
largely depend on the next 36 to 48 hours worth of rainfall. With
soils already saturated in Southeast Alabama and a good portion of
Southern Georgia, little additional rainfall will be absorbed there
and will thus be converted into runoff, increasing river flood
potential. River systems in South Central Georgia and the Florida
Big Bend still have plenty of capacity and riverine flooding is not
anticipated in these areas with this system.

.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 59 71 62 70 44 / 70 50 80 80 20
Panama City 60 71 62 66 46 / 80 50 80 70 20
Dothan 54 64 58 64 40 / 80 80 90 70 20
Albany 53 65 58 66 40 / 80 70 90 80 20
Valdosta 56 71 60 71 44 / 60 50 80 80 30
Cross City 61 77 61 74 48 / 20 30 60 70 30
Apalachicola 62 70 64 68 48 / 60 40 70 80 30

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...FLASH FLOOD WATCH until 6 AM CST Tuesday for Central Walton-
Holmes-Inland Walton-Jackson-Washington.
GA...FLASH FLOOD WATCH until 7 AM EST Tuesday for Baker-Ben Hill-
Calhoun-Clay-Dougherty-Early-Irwin-Lee-Miller-Quitman-
Randolph-Seminole-Terrell-Tift-Turner-Worth.
AL...FLASH FLOOD WATCH until 6 AM CST Tuesday for Coffee-Dale-
Geneva-Henry-Houston.
GM...None.

BLOCK

AREA FORECAST DISCUSSION

NWS TALLAHASSEE FL

1103 PM EST Mon Feb 11 2013

...UPDATED FOR AVIATION DISCUSSION...

.NEAR TERM [through Tonight]...
Convection continues to wind down during the late evening hours.
Meanwhile, a large area of moderate rain with embedded
thunderstorms was developing from C/S AL west into LA. This area
of rain was roughly on the broad nose of a newly developed low-
level moisture transport maximum - currently focused into coastal
Louisiana and Mississippi. The RAP projects that the ribbon of
strongest moisture transport should develop northeast into our
area by around 03z, with roughly similar PWAT values. Therefore,
we anticipate that rain - heavy at times, with embedded storms -
will redevelop across much of the NW half to two-thirds of our
area this evening.

AREA FORECAST DISCUSSION

NWS COLUMBIA SC

1037 AM EST TUE FEB 12 2013

.SYNOPSIS...
A STALLED FRONT SOUTH OF THE FORECAST AREA WILL BECOME A WARM
FRONT AS LOW PRESSURE DEVELOPS IN THE LOWER MISSISSIPPI RIVER
VALLEY. THE LOW WILL BE NEAR THE FORECAST AREA WEDNESDAY. WEAK
HIGH PRESSURE WILL DOMINATE THURSDAY AND FRIDAY BEHIND THE LOW
LIFTING NORTHEAST OF THE AREA.

.NEAR TERM /THROUGH TONIGHT/...
TODAY...THE FRONT WILL REMAIN STALLED SOUTH OF THE AREA THIS
AFTERNOON. RAIN COVERAGE HAS DIMINISHED BEHIND A MID-LEVEL
SHORTWAVE TROUGH. COVERAGE MAY INCREASE AGAIN LATE IN THE DAY AS
STRONGER ISENTROPIC LIFT DEVELOPS AHEAD OF THE DEVELOPING WARM
FRONT. THE TEMPERATURE FORECAST APPEARS ON TRACK WITH HIGHS MAINLY
IN THE LOWER 60S.

TONIGHT...THE WATER VAPOR IMAGERY SHOWED A STRONG SHORTWAVE TROUGH
OVER EAST TEXAS WHICH SHOULD HELP CAUSE LOW PRESSURE TO DEVELOP IN
THE LOWER MISSISSIPPI RIVER VALLEY. THE STALLED FRONT TO OUR SOUTH
WILL BECOME A WARM FRONT. THE MODELS SHOW STRONG ISENTROPIC LIFT
OVER OUR AREA TONIGHT NORTH OF THE FRONT. THE NAM AND GFS PLUS
SREF GUIDANCE INDICATE RAINFALL OF 0.75 TO 1.25 OF AN INCH OF RAIN
TONIGHT. THE NAM LI PATTERN SUGGESTS THE WARM FRONT WILL REMAIN TO
OUR SOUTH OVERNIGHT AND SHOWS SURFACE-BASED LI/S ABOVE ZERO.
HOWEVER...THE NAM SHOWS STEEP LAPSE RATES ALOFT WITH CROSS TOTALS
INCREASING TO AROUND 26. THERE MAY BE A FEW ELEVATED
THUNDERSTORMS. WE USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE
FORECAST.

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
THE MODELS SHOW LOW PRESSURE NEAR THE FORECAST AREA WEDNESDAY WITH
DEEPER MOISTURE SHIFTING EAST OF THE AREA. THE RAIN CHANCE SHOULD
DIMINISH FROM WEST TO EAST. THE LOW WILL BE LIFTING NORTHEAST OF
THE AREA WEDNESDAY NIGHT WITH DRY RIDGING DOMINATING THURSDAY. WE
USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.

.LONG TERM /THURSDAY THROUGH MONDAY/...
THE GFS AND ECMWF SHOWED WEAK RIDGING CONTINUING TO DOMINATE
FRIDAY. THE GFS WAS MORE PRONOUNCED WITH A FRONT AND ASSOCIATED
MOISTURE SATURDAY INTO SATURDAY NIGHT COMPARED TO THE ECMWF. THE
GFS AND ECMWF MOS POPS WERE CONSISTENT WITH VERY LOW POPS. WE KEPT THE
FORECAST DRY. THE GFS AND ECMWF MOS SUPPORTED NEAR NORMAL
TEMPERATURES FRIDAY BECOMING BELOW NORMAL SATURDAY.

.AVIATION /15Z TUESDAY THROUGH SUNDAY/...
WEAK HIGH PRESSURE WILL RIDGE INTO THE AREA FROM THE NORTH TODAY. A
COLD FRONT ALONG THE GULF COAST STATES WILL MOVE NORTHWARD TONIGHT.
LOW PRESSURE WILL DEVELOP ALONG THE FRONT...AND CROSS THE TAF SITES
WEDNESDAY.

PREVAILING VFR CONDITIONS ACROSS THE TAF SITES THROUGH SUNSET.
LATEST REGIONAL COMPOSITE RADAR SHOWING RAIN HAS MOVED EAST OF THE
TAF SITES...BUT LATEST RUC IS INDICATING MORE RAIN WILL BE DEVELOPING
OVER THE AREA BY LATE AFTERNOON OR EARLY THIS EVENING. WINDS WILL
SHIFT TO THE NORTHEAST BY EARLY AFTERNOON. WILL SEE SOME BREAKS
IN THE CLOUDS FOR MOST OF THE TAF SITES AT LEAST INTO THE EARLY
AFTERNOON HOURS.

AFTER SUNSET DEEP MOISTURE AND LIFT RETURNING TO ALL TAF SITES AHEAD
OF AN APPROACHING LOW PRESSURE SYSTEM. EXPECT WIDESPREAD MVFR
CONDITIONS AROUND 13/00Z TO LOWER TO IFR DURING THE EVENING.

EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE FOR MVFR OR LOWER
CONDITIONS THROUGH WEDNESDAY EVENING AS A LOW PRESSURE SYSTEM
CROSSES THE REGION.

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

AREA FORECAST DISCUSSION

NWS NORTHERN INDIANA

307 PM EST TUE FEB 12 2013

.SHORT TERM...
SFC RIDGING INVOF OF OH RVR WILL BREAK DOWN INADV OF SW CLIPPER
DROPPING OUT OF SWRN CANADA WED AFTN. HWVR NO SENSIBLE WX OF
CONSEQUENCE XPCD WITHIN THIS EVOLUTION THROUGH THIS PD.

MIXING/EROSION OF SC CLD DECK ONGOING THIS AFTN W/PARTIAL SUNSHINE
NOW ACRS MUCH OF ERN HALF CWA BUT WRN FLANK EXTENDING BACK INTO NE
IL HOLDING TOUGH AND MAY POSE A BUST OVERNIGHT WRT MIN TEMPS. ATTM
SHRT TERM RUC GIVES A NOD TWD PRIOR EVEN MOS BLEND. OTRWS AT LEAST
PARTIAL INSOLATION XPCD AGAIN ON WED W/STGR DIURNAL WITHIN MODEST LL
SWRLY FLW. IN FACT MOS MAX TEMP SPLIT ESSENTIALLY EVEN AND REFLECTED
IN GRIDDED MAXS.

.LONG TERM... /THURSDAY THROUGH TUESDAY/
ACTIVE PATTERN IN STORE FOR THE LONG TERM PERIOD. ONE MORE DAY OF
ABOVE NORMAL TEMPS ON TAP FOR THURSDAY AHEAD OF SHOT OF ARCTIC AIR
DROPPING SE ACROSS THE PLAINS. STRONG FORCING ALONG THE FRONT WILL
STIR UP AT LEAST A CHC FOR RAIN OR SNOW SHOWERS BUT OVERALL QPF
APPEARS MINIMAL AT THIS POINT. POPS STILL HELD IN CHC/SCHC RANGE
FOR NOW.

GREATER FOCUS THEN TURNS TOWARDS LAKE EFFECT POTENTIAL AS STG NW
FLOW SETS UP WITH SFC-850 MB DELTA T`S PUSHING 20 C AND SFC-700 MB
DELTA T`S PUSHING UPR 20S. NAM/WRF SHOW A PERIOD OF FAVORABLE
COLLOCATION OF DGZ AND TOP OF STRONG OMEGA. INVERSION HGTS BEGIN TO
CLIMB...ESPECIALLY DURING THE DAY FRIDAY WHEN SOME ADDITIONAL
SYNOPTIC MSTR ARRIVES AND A REINFORCING SHOT OF COLD AIR. HAVE
TENDED TO FOCUS GREATEST POPS FRIDAY TO MATCH WITH THE ABOVE SETUP.
ACCUMS AT THIS POINT APPEAR TO BE ON THE LIGHTER SIDE BUT WILL NEED
TO BE WATCHED IN COMING FORECASTS. WHILE AN OUTLIER...SEVERAL RUNS
OF THE GEM NHEM MODEL HAVE BEEN SHOWING PHASING OF N/S STREAM
SYSTEMS SOONER THAN LATER WITH A STORM AFFECTING THE GREAT LAKES VS
EAST COAST. ECMWF/GFS DO NOT PHASES THE ENERGY UNTIL REACHING EAST
COAST SO AT THIS POINT HAVE TO PUT IT ON THE BACK BURNER BUT WILL
NEED TO WATCH.

LAKE EFFECT WILL LINGER POTENTIALLY THROUGH MUCH OF THE WEEKEND WITH
CONTINUED NW FLOW AND 850 MB RIDGING STILL TO THE WEST UNTIL LATE
SUNDAY. NEXT SYSTEM TO FOCUS ON WILL BE WHAT LOOKS LIKE A PANHANDLE
HOOK COMING TOWARDS THE REGION MONDAY NIGHT INTO TUESDAY. SIGNALS
POINT TOWARDS MEASURABLE PRECIP FOR PARTS OF THE AREA BUT EXACT
TRACK AND AMOUNT OF COLD AIR REMAIN QUESTIONABLE THIS FAR OUT IN THE
FORECAST. HAVE WENT WITH MID-HIGH END CHC POPS WITH MIX OF RAIN OR
SNOW WITH LIKELY REFINEMENT OF FORECAST TO COME OVER THE NEXT
SEVERAL DAYS.

.AVIATION...
MVFR SC DECK EXTENDING WWD INTO NE IL HOLDING TOUGH THIS AFTN AND
NOT MIXING OUT AS ORIGINALLY XPCD. THUS MADE AMENDMENTS TO PUSH
BACK CLRG TO LT EVENING BASED ON CONTD EWD EROSION OUT OF WRN IL.
OTRWS WX NIL THIS TAF PD W/VFR CONDS XPCD OUTSIDE LT THIS AFTN/EVENING.

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

SHORT TERM...T
LONG TERM...FISHER
AVIATION...T

AREA FORECAST DISCUSSION

NWS DODGE CITY KS

545 AM CST TUE FEB 12 2013

...UPDATED AVIATION SECTION...

.SYNOPSIS...
ISSUED AT 1124 PM CST MON FEB 11 2013

AT 00Z TUESDAY A 300MB JET STREAK EXTENDED FROM OLD MEXICO INTO
NORTHEAST TEXAS. A -32C TO -33C 500MB TROUGH STRETCHED FROM
NORTHEAST COLORADO INTO EAST CENTRAL ARIZONA AND THE 12 HOUR
HEIGHT TENDENCIES INDICATED THE BETTER HEIGHT FALLS AT THE 500MB
LEVEL WAS ACROSS NEW MEXICO. A 700MB TROUGH EXTENDED FROM
NORTHEAST COLORADO INTO EASTERN ARIZONA. AT THE 850MB LEVEL THE
BETTER MOISTURE RETURN AS OF 00Z TUESDAY APPEARS TO BE LOCATED
ACROSS SOUTHERN TEXAS. AMARILLO UPPER AIR SOUNDING AT 00Z DID
INDICATED A WEDGE OF MOISTURE AROUND THE 650MB LEVEL OR AROUND
12000FT MSL/9000FT ASL. AT THE SURFACE AN AREA OF HIGH PRESSURE
WAS LOCATED ACROSS NORTHWEST KANSAS WITH A SURFACE BOUNDARY
EXTENDING SOUTH FROM EASTERN COLORADO ACROSS EASTERN NEW MEXICO
INTO SOUTHWEST TEXAS.

.UPDATE...
ISSUED AT 441 AM CST TUE FEB 12 2013

OVER THE LAST SEVERAL HOURS THE STEADIER AND HEAVIER PRECIPITATION
RELATED FAIRLY WELL WITH THE RAP 700MB BAROCLINIC ZONE THAT WAS
MOVING ACROSS SOUTHWEST KANSAS. USING THIS AS A GUIDE AND BASED
ON THE 06Z NAM I290 ISENTROPIC LIFT ALONG WITH THE LOCATION OF THE
300MB JET STEAK HAVE DECIDED TO CANCEL WHAT IS LEFT OF THE WINTER
WEATHER ADVISORY. ALTHOUGH PERIODS OF LIGHT SNOW WILL BE POSSIBLE
ACROSS SOUTH CENTRAL KANSAS THIS MORNING, IT CURRENTLY APPEARS
SNOW ACCUMULATIONS WILL END UP BEING LESS THAN TWO INCHES. THE
HIGHER SNOW ACCUMULATIONS STILL WILL BE NEAR THE OKLAHOMA BORDER
AND WOULD NOT BE SURPRISED TO SEE A FEW 2 INCH REPORTS SOUTH OF
BUTTERMILK OR NEAR KIOWA IN SOUTHEAST BARBER COUNTY.

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 143 AM CST TUE FEB 12 2013

700MB TROUGH/MID LEVEL BAROCLINIC ZONE WILL CROSS SOUTHWEST
KANSAS EARLY THIS MORNING. LOW LEVEL MOISTURE AND ISENTROPIC LIFT
IN THE I290 TO I300 LEVEL ARE FORECAST TO IMPROVE AHEAD OF THIS
700MB TROUGH. BASED ON MOST RECENT RADAR RETURNS, SURFACE
OBSERVATIONS/REPORTS, AND LATEST SATELLITE PRECIPITATION ESTIMATES
WILL CONTINUE WITH THE CURRENT WINTER WEATHER ADVISORY EARLY THIS
MORNING.

THE MID LEVEL BAROCLNIC ZONE IS CURRENTLY FORECAST TO MOVE INTO
THE TEXAS PANHANDLE AND NORTHWEST OKLAHOMA EARLY THIS AFTERNOON,
AND THE BETTER ISENTROPIC LIFT IS CURRENTLY FORECAST TO SHIFT
SOUTH OF THE OKLAHOMA BORDER. AT THE I29O ISENTROPIC SURFACE AT
18Z THERE IS EVEN A HINT OF DOWNGLIDE DEVELOPING ACROSS FAR
WESTERN KANSAS. WILL THEREFORE BEGIN TO TAPER PRECIPITATION OFF
FROM WEST TO EAST DURING THE AFTERNOON AS THE MID LEVEL TROUGH
MOVES EAST/SOUTHEAST. ADDITIONAL SNOW ACCUMULATIONS FROM LATE
MORNING INTO THE LATE AFTERNOON ACROSS THE SOUTHERN TIER OF KANSAS
CURRENTLY APPEARS TO BE AN ONE INCH OR LESS BASED ON HOW QUICKLY
THE 700MB TROUGH MOVES SOUTHEAST ALONG WITH THE LOCATION OF THE
UPPER LEVEL JET, 850MB WARM AIR ADVECTION, AND ISENTROPIC LIFT. A
FEW LOCATIONS COULD HAVE SNOW AMOUNTS AROUND 2 INCHES IN SOUTHERN
COMANCHE AND BARBER COUNTIES.

THERE WILL BE LITTLE DIURNAL CHANGE IN TEMPERATURES TODAY WHERE
CLOUDS AND SNOW ARE EXPECTED. WILL THEREFORE UNDERCUT GUIDANCE AND
KEEP AFTERNOON HIGHS MAINLY IN THE 30S. FURTHER NORTH AND
NORTHWEST WHERE CLEARING SKIES ARE ANTICIPATED WILL TREND TOWARDS
THE WARMER 850MB MIX DOWN TEMPERATURES WHICH WOULD YIELD HIGHS IN
THE LOW TO MID 40S. TONIGHT WHERE SNOW ACCUMULATIONS OF ONE INCH
OR MORE IS EXPECTED HAVE UNDERCUT GUIDANCE AND LOWERED MINIMUMS
INTO THE TEENS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 321 AM CST TUE FEB 12 2013

TRANQUIL WEATHER IS ANTICIPATED WEDNESDAY AS HIGH PRESSURE TREKS
EASTWARD ACROSS THE SOUTHERN PLAINS. MOSTLY CLEAR SKIES AND DRY
CONDITIONS ARE FORECASTED DURING THIS PERIOD WITH NORTHWEST WINDS
BECOMING BREEZY DURING THE AFTERNOON. HIGHS ARE FORECASTED REACH
INTO THE UPPER 40S TO AROUND 50 DEGREES WITH THE EXCEPTION OF ALONG
THE KS/OK BORDER WHERE MID 40S WILL BE POSSIBLE DUE TO SNOW ON THE
GROUND. LOWS THURSDAY MORNING ARE ANTICIPATED TO FALL INTO THE MID
TO UPPER 20S.

MEANWHILE, AN UPPER LEVEL SHORTWAVE WILL MOVE DOWN THROUGH THE
NORTHERN ROCKIES AND NORTHERN PLAINS WEDNESDAY NIGHT THEN INTO THE
CENTRAL PLAINS THURSDAY. THIS WILL IN TURN HELP PUSH A COLD FRONT
THROUGH WESTERN KANSAS THURSDAY AFTERNOON. MID LEVELS SATURATE AS
THIS FRONT MOVES THROUGH THE AREA INCREASING CLOUD COVER ACROSS
WESTERN KANSAS. I HAVE CONTINUED A SLIGHT CHANCE OF SNOW SHOWERS
ACROSS FAR WESTERN KANSAS THURSDAY WITH THE REMAINDER OF WESTERN
KANSAS REMAINING DRY. BREEZY NORTHERLY WINDS ARE ANTICIPATED BEHIND
THE COLD FRONT WITH HIGHS IN THE MID 40S. LOWS BY FRIDAY MORNING
LOOK TO RANGE FROM THE LOWER 20S ACROSS WEST CENTRAL KANSAS TO UPPER
20S ACROSS SOUTH CENTRAL KANSAS. HIGH PRESSURE BUILDS INTO THE AREA
ON FRIDAY WITH DECREASING CLOUDS. COLDER TEMPERATURES ARE FORECASTED
FRIDAY WITH HIGHS ONLY REACHING TO AROUND 40 DEGREES.

UPPER LEVEL RIDGING THEN BUILDS ACROSS THE PLAINS THIS WEEKEND
WITH HIGH PRESSURE BEING THE DOMINATING FEATURE AT THE SURFACE. THIS
WILL BRING PARTLY CLOUDY SKIES AND DRY CONDITIONS TO WESTERN KANSAS.
LOWS SLOWLY INCREASE EACH MORNING WITH LOWER 20S SATURDAY MORNING,
MID TO UPPER 20S SUNDAY MORNING, AND LOWER 30S MONDAY MORNING. HIGHS
THIS WEEKEND ARE FORECASTED TO BE IN THE MID TO UPPER 40S SATURDAY
THEN IN THE 50S ON SUNDAY.

MODELS SUGGEST AN UPPER LEVEL SHORTWAVE TO MOVE INTO THE CENTRAL
ROCKIES ON MONDAY. IF THIS VERIFIES, THIS WILL BRING A COLD FRONT
THROUGH WESTERN KANSAS AS THE DAY PROGRESSES WITH INCREASED CLOUD
COVER. MODELS ALSO SUGGEST A SLIGHT CHANCE OF SHOWERS MONDAY
AFTERNOON INTO MONDAY NIGHT MAINLY ACROSS CENTRAL AND SOUTH CENTRAL
KANSAS. HIGHS MONDAY ARE FORECASTED TO BE IN THE 40S WITH LOWER 50S
ACROSS SOUTH CENTRAL KANSAS.

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 540 AM CST TUE FEB 12 2013

LIGHT SNOW SHOWERS WILL BE POSSIBLE ACROSS THE DODGE CITY TERMINAL
OVER THE NEXT COUPLE OF HOURS WITH MVFR CONDITIONS AOA025.
OTHERWISE EXPECT DECREASING HIGH CLOUDS AOA100 AS THE DAY
PROGRESSES. WINDS WILL BE LIGHT AND VARIABLE BECOMING NORTHWEST AT
5 TO 10 KNOTS THIS AFTERNOON.

.PRELIMINARY POINT TEMPS/POPS...
DDC 40 20 48 28 / 20 10 0 0
GCK 43 18 49 26 / 10 0 0 0
EHA 35 17 44 26 / 20 0 0 0
LBL 36 17 44 25 / 70 10 0 0
HYS 48 19 51 29 / 0 0 0 0
P28 37 18 45 29 / 40 10 0 0

.DDC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
KSZ086>090.

UPDATE...BURGERT
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...HOVORKA_42
AVIATION...HOVORKA_42

AREA FORECAST DISCUSSION

NWS DODGE CITY KS

444 AM CST TUE FEB 12 2013

...UPDATED TO REMOVE REMAINING WINTER WEATHER ADVISORY...

.SYNOPSIS...
ISSUED AT 1124 PM CST MON FEB 11 2013

.UPDATE...
ISSUED AT 441 AM CST TUE FEB 12 2013

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 143 AM CST TUE FEB 12 2013

THERE WILL BE LITTLE DIURNAL CHANGE IN TEMPERATURES TODAY WHERE
CLOUDS AND SNOW ARE EXPECTED. WILL THEREFORE UNDERCUT GUIDANCE AND
KEEP AFTERNOON HIGHS MAINLY IN THE 30S. FURTHER NORTH AND
NORTHWEST WHERE CLEARING SKIES ARE ANTICIPATED WILL TREND TOWARDS
THE WARMER 850MB MIXDOWN TEMPERATURES WHICH WOULD YIELD HIGHS IN
THE LOW TO MID 40S. TONIGHT WHERE SNOW ACCUMULATIONS OF ONE INCH
OR MORE IS EXPECTED HAVE UNDERCUT GUIDANCE AND LOWERED MINIMUMS
INTO THE TEENS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 321 AM CST TUE FEB 12 2013

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1124 PM CST MON FEB 11 2013

MID LEVEL MOISTURE WILL THICKEN AND LOWER EARLY THIS MORNING AS A
700MB TROUGH MOVES SOUTHEAST ACROSS WESTERN KANSAS. AT THIS TIME
BASED ON THE LATEST BUFR SOUNDINGS THE CLOUD BASES WILL STAY ABOVE
THE 850MB LEVEL SO VFR CIGS ARE EXPECTED ALONG AND AHEAD OF THE
700MB TROUGH. GIVEN THE DRY LAYER PRESENT BELOW THE 850MB LEVEL THE
PRECIPITATION CHANCES DO NOT LOOK VERY GOOD AT DDC OR GCK SO HAVE
DECIDED TO REMOVE PRECIPITATION CHANCES. WINDS AT LESS THAN 10
KNOTS WILL PERSIST THROUGH MID DAY TUESDAY AS AN AREA OF HIGH
PRESSURE AT THE SURFACE CROSSES THE CENTRAL PLAINS.

.PRELIMINARY POINT TEMPS/POPS...
DDC 40 20 48 28 / 20 10 0 0
GCK 43 18 49 26 / 10 0 0 0
EHA 35 17 44 26 / 20 0 0 0
LBL 36 17 44 25 / 70 10 0 0
HYS 48 19 51 29 / 0 0 0 0
P28 37 18 45 29 / 40 10 0 0

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...BURGERT
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...HOVORKA_42
AVIATION...BURGERT

AREA FORECAST DISCUSSION

NWS JACKSON KY

1006 PM EST WED FEB 13 2013

.UPDATE...
ISSUED AT 1006 PM EST WED FEB 13 2013

PRECIP SHOULD BE DONE FOR THE NIGHT AND IS REMOVED FROM THE 1ST
PERIOD FORECAST. CLOUDS WILL BE TRICKY...BUT SHOULD GENERALLY BE MOST
PREVALENT IN THE SE AND LEAST IN THE NW OVERNIGHT.

UPDATE ISSUED AT 655 PM EST WED FEB 13 2013

HAVE UPDATED PRIMARILY FOR SKY COVER AND POPS IN THE FIRST PERIOD.
CLEARING WAS ARRIVING FROM THE WEST EARLY THIS EVENING...AND BASED ON
THE RUC AND NAM SHOULD PROGRESS SOUTHEAST TONIGHT. HOWEVER...THEY DO
ALSO SUGGEST ANOTHER INCREASE IN CLOUDS FROM THE WEST BEFORE DAWN.
THE ONLY RETURNS LEFT ON RADAR WERE IN THE FAR EASTERN PART OF THE
AREA...WERE VERY LIGHT AND ON THE DECREASE. HAVE LOWERED POPS TO
NOTHING MORE THAN 20 PERCENT OVER THE EASTERN TIP OF THE AREA...BUT
DID ALLOW FOR SOME FLURRIES A BIT FURTHER WEST.

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 231 PM EST WED FEB 13 2013

THE SFC LOW HAS PUSHED EAST INTO VA AND A SHORT PERIOD OF COLDER AIR
IS CYCLING INTO THE AREA ON NW WINDS. MID LEVEL TROF RUNS FROM NEAR
CLE TO CMH TO BNA AND WILL FOLLOW TO THE EAST LATER THIS AFTERNOON.
WITH THE PASSAGE OF THE MID LEVEL TROF THIS EVENING THE PCPN SHOULD
COME TO AN END AND RIDGING AT BOTH THE SFC AND MID LEVELS WILL BUILD
INTO THE AREA. EXPECTING TEMPS TO FALL SLOWLY THE REST OF THIS
AFTERNOON AND OVERNIGHT. CURRENT TEMPS IN THE MID 30S WILL BOTTOM OUT
IN THE MORNING NEAR 30. THEN THE RIDGING WILL BRING A RETURN TO MLDER
TEMPS THU AFTERNOON WITH HIGHS CLIMBING TO THE LOWER 50S. THE NEXT
DISTURBANCE...CURRENTLY IN THE NRN PLAINS...WILL PUSH ACROSS THE WRN
GREAT LAKES THU NIGHT BUT NOT IN TIME TO BRING MUCH COLDER TEMPS AS
THE WINDS WILL SLOWLY RETURN TO THE WEST AND THEN SW TOWARDS FRI DAWN
SO TEMPS WILL ONLY DROP TO THE LOWER 30S THU NIGHT...BUT UNDER PARTLY
CLOUDY SKIES AND WITHOUT ANY PCPN.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM EST WED FEB 13 2013

A FAIRLY ACTIVE AND PROGRESSIVE WEATHER PATTERN WILL BE IN PLACE
DURING THE LONG TERM PORTION OF THE FORECAST. A SERIES OF
DISTURBANCES WILL CARVE OUT A DEEP TROF OVER THE EASTERN UNITED
STATES FOR THE UPCOMING WEEKEND. AS COLDER AIR MOVES INTO THE AREA ON
FRIDAY...MAY SEE SOME RAIN OR SNOW SHOWERS. WITH COLD AIR ADVECTION
AND SOME UPSLOPE FLOW SNOW SHOWERS WILL ALSO BE POSSIBLE AT TIMES
FROM FRIDAY NIGHT INTO SATURDAY NIGHT...MAINLY IN THE EASTERN PART OF
THE FORECAST AREA.

THE UPPER LEVEL TROF WILL QUICKLY MOVE EAST WITH WEAK RIDGING OVER
THE OH VALLEY BY MONDAY. THIS WILL RESULT IN A QUICK WARM UP WITH
TEMPERATURES RETURNING TO ABOVE NORMAL READINGS ON MONDAY AFTER WELL
BELOW NORMAL TEMPERATURES OVER THE WEEKEND. AN APPROACHING COLD FRONT
WILL BRING ANOTHER ROUND OF RAIN SHOWERS MONDAY NIGHT INTO
TUESDAY. THERE COULD BE SOME LIGHT SNOW SHOWERS TUESDAY NIGHT AS
COLDER AIR RETURNS ONCE AGAIN.

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 741 PM EST WED FEB 13 2013

CONDITIONS WERE LARGELY MVFR TO START THE PERIOD...WITH SOME
LOCALIZED IFR OVER THE EASTERN TIP OF THE STATE DUE MAINLY TO
CEILINGS. THERE WAS ALSO VFR BEGINNING TO ARRIVE FROM THE NW AT
MOUNT STERLING. OVERALL IMPROVEMENT IN CONDITIONS IS FORECAST THIS
EVENING FROM NW TO SE...WITH MAINLY VFR EXPECTED BY ABOUT 05Z.
ANOTHER INCREASE IN CLOUDS IS EXPECTED FROM NW TO SE AROUND DAWN.
THIS COULD BRING MVFR...BUT IF CEILINGS OCCUR THEY ARE MORE LIKELY TO
BE LOW VFR.

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...HAL
SHORT TERM...DUSTY
LONG TERM...SBH
AVIATION...HAL

AREA FORECAST DISCUSSION

NWS JACKSON KY

741 PM EST WED FEB 13 2013

.UPDATE...
ISSUED AT 655 PM EST WED FEB 13 2013

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 231 PM EST WED FEB 13 2013

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM EST WED FEB 13 2013

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 741 PM EST WED FEB 13 2013

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...HAL
SHORT TERM...DUSTY
LONG TERM...SBH
AVIATION...HAL

AREA FORECAST DISCUSSION

NWS JACKSON KY

655 PM EST WED FEB 13 2013

.UPDATE...
ISSUED AT 655 PM EST WED FEB 13 2013

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 231 PM EST WED FEB 13 2013

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM EST WED FEB 13 2013

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 108 PM EST WED FEB 13 2013

CEILINGS HAVE DROPPED TO IFR LEVELS. PRECIP HAS FALLEN THROUGH THE
MORNING ACROSS THE AREA IN THE FORM OF -RA. EXPECT THIS TO MIX WITH
AND THEN CHANGE TO -SN LATER THIS AFTERNOON. ACCUMULATIONS WILL BE
GENERALLY LIGHT EXCEPT IN NORTHERN KY WHERE A QUICK INCH COULD FALL.
PRECIP SHOULD END ACROSS EASTERN KENTUCKY BETWEEN 1-3Z WITH
CIGS/VSBY LIFTING TO VFR. WHERE THERE IS PRECIPITATION...THE -RA AND
THEN THE MIX OF TYPES COULD CAUSE SOME ICE ACCUMULATION WHEN AIRBORNE.

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...HAL
SHORT TERM...DUSTY
LONG TERM...SBH
AVIATION...DUSTY

AREA FORECAST DISCUSSION

NWS GAYLORD MI

418 PM EST TUE FEB 12 2013

.SYNOPSIS...
ISSUED AT 415 PM EST TUE FEB 12 2013

WEAK HIGH PRESSURE WILL BUILD INTO THE NORTHERN GREAT LAKES TONIGHT
AND WEDNESDAY. THIS PATTERN WILL GENERATE ABOVE NORMAL TEMPERATURES
AND OCCASIONAL FLURRIES...ACROSS THE NORTHERN MICHIGAN INTO THURSDAY.

HOWEVER...THE NEXT SYSTEM TO INFLUENCE THE GREAT LAKES ARRIVES
THURSDAY...BEFORE QUICKLY LIFTING NORTHEAST INTO QUEBEC FRIDAY. THIS
SYSTEM WILL GENERATE ANOTHER ROUND OF SNOW ACROSS NORTHERN
MICHIGAN THURSDAY...WHILE ALSO USHERING IN MUCH COLDER CONDITIONS
FRIDAY AND INTO THE WEEKEND. ACCUMULATING LAKE EFFECT SNOW CAN BE
EXPECTED OVER THE WESTERN GREAT LAKES THIS WEEKEND.

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 415 PM EST TUE FEB 12 2013

COLD AIR ADVECTION HAS ABOUT MAXED OUT BEHIND YESTERDAY`S DEPARTING
STORM...WITH LATEST HIGH RES RUC ANALYSIS PLACING CIRCA -11C H85
TEMPERATURES ACROSS THE NORTH WOODS. DESPITE EXCEEDINGLY LOW
INVERSIONS (H85 PER SAME RUC ANALYSIS)...MOISTURE DEPTH EXTENDING
TO THE LOW END OF THE FAVORED DGZ CONTINUES TO KICK OFF WIDESPREAD
FLURRIES IN FAVORED WEST FLOW LAKE AREAS. ABUNDANT LOW LEVEL
MOISTURE ALSO LEADING TO A MAINLY CLOUDY DAY...WITH ANY SUBSTANTIAL
CLEARING OF NOTE BACK ACROSS WISCONSIN. THIS CLEARING APPEARS TIED
TO DOWNWARD FORCING ON BACKSIDE OF RATHER COMPACT SHORTWAVE
PINWHEELING EAST INTO NORTHERN LAKE MICHIGAN. NO SIGNIFICANT
CONCERNS THROUGH THE SHORT TERM (WEDNESDAY)...ALTHOUGH LINGERING
FLURRIES AND CLOUD TRENDS WILL NEED ADDRESSING.

WISCONSIN SHORTWAVE WILL STEADILY AND RAPIDLY PUSH ACROSS THE AREA
THIS EVENING...AND LACK OF ANY APPRECIABLE MOISTURE SHOULD PRECLUDE
MUCH...IF ANY...LAKE OR SYNOPTIC RESPONSE. H85 TEMPERATURES SLOWLY
WARM IN DEVELOPING WEAK SOUTHWEST FLOW WAA REGIME...REACHING THE
NEGATIVE SINGLE DIGITS BY MORNING. NAM-WRF BUFFER SOUNDINGS SHOW LOW
LEVEL MOISTURE FALLING BELOW -10C ISOTHERM...WHICH COMBINED WITH
LOWERING DELTA T/S...WOULD SUPPORT A QUICK DEMISE TO ONGOING
FLURRIES. NOT WILLING TO BITE ON THIS JUST YET...AND PREFER TO KEEP
FLURRIES IN THE FORECAST...SIMPLY FOLLOWING THE WINDS FOR THERE
PLACEMENT (WHICH SUGGESTS THEY SHOULD CONFINE THEMSELVES IN FAVORED
SOUTHWEST FLOW AREAS THROUGH THE NIGHT). CLOUD COVER REMAINS A
FORMIDABLE CHALLENGE...ESPECIALLY GIVEN WHAT IS OCCURRING BEHIND
UPSTREAM WAVE. DO HAVE SOME TREPIDATION GOING TOO AGGRESSIVE WITH
CLOUDS OVERNIGHT...ESPECIALLY IN NON-FAVORED LAKE AREAS. SUBTLE WARM
ADVECTION AND POST-WAVE DOWNWARD RESPONSE JUST MAY WORK IN TANDEM TO
FORCE MUCH MORE CLEARING THAN THIS FORECAST WILL SUGGEST. WILL
TREND PARTLY CLOUDY ACROSS EASTERN UPPER AND NORTHEAST LOWER AS A
STARTING POINT...WITH KNOWLEDGE THAT COMPLETELY CLOUDY OR CLEAR IS
THE MORE LIKELY OUTCOME. TEMPERATURES...OF COURSE...HIGHLY DEPENDENT
ON HOW THIS WHOLE CLOUD THING UNFOLDS. MID AND UPPER TEENS MAY BE
SEVERAL DEGREES TOO "WARM". WE SHALL SEE.

SAME STORY HEADING INTO WEDNESDAY...WITH SOME LINGERING FLURRIES AND
MOSTLY TO PARTLY CLOUDY SKIES. LOW LEVEL MODIFICATION
CONTINUES...SUGGESTING HIGHS IN THE LOWER AND MIDDLE 30S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 415 PM EST TUE FEB 12 2013

MAIN FORECAST CONCERNS WILL BE POTENTIAL FOR ACCUMULATING LAKE
ENHANCED SNOWS STARTING THURSDAY AND CONTINUING INTO THE
WEEKEND.

THE LATEST HEMISPHERIC ANALYSIS SHOWS A STABLE 3-WAVE PATTERN WITH
LARGE SCALE TROUGHING OVER CENTERED OVER JAMES BAY...EAST ASIA
/AROUND 120E/ AND CENTRAL EUROPE. A VERY STRONG ZONAL JET REMAINS
OVER EAST ASIA AND THE WESTERN PACIFIC...WITH A SLIT FLOW OVER THE
EASTERN PACIFIC EXTENDING INTO THE WEST COAST. THE SPLIT FLOW MERGES
TO FORM A FASTER JET THE SOUTHEASTERN U.S.

THURSDAY...AN AMPLIFYING PATTERN IS EXPECTED WITH STRONG PACIFIC JET
TO BEEF UP THE WEST COAST RIDGE...RESULTING IN INCREASED TROUGHING
OVER THE EASTERN TWO THIRDS OF THE CONUS BY THURSDAY. SHORT WAVE
ENERGY IS EXPECTED TO ROUND THE TOP OF THE RIDGE ON
WEDNESDAY...BEFORE DIVING INTO THE GREAT LAKES BY THURSDAY. AN
ASSOCIATED SURFACE RESPONSE/CLIPPER SYSTEM WILL MOVE THOUGH THE
GREAT LAKES...BRINGING NORTHERN MICHIGAN THE NEXT CHANCE OF SOME
LIGHT SNOW. THE AMOUNT OF MOISTURE THIS SYSTEM HAS TO WORK WITH IS
NOT TERRIBLE...WITH MODEL SOUNDINGS SHOWING P-WATS OF AROUND 0.3 TO
0.4 INCHES ACROSS THE CWA. THE DEGREE OF FORCING REMAINS IN SOME
QUESTION...WITH TWO DISTINCT AREAS OF ENHANCED PVA EXPECTED TO MOVE
THROUGH THE REGION EMBEDDED IN THE SHEARED PIECE OF ENERGY. THE
NAM/GFS WANT TO SPIN UP A STRONGER LOW WITH THIS FEATURE...WHILE THE
ECMWF/GEM KEEP THE SURFACE LOW MORE BENIGN. PREFER THE LATTER OF THE
SOLUTIONS...GIVEN THAT THESE TWO PIECES OF ENERGY DO NOT NECESSARILY
PHASE TOGETHER. OVERALL LOOKING LIKE A 1 TO 2..PERHAPS LOCALLY 3
INCH SNOW EVENT. RAPIDLY CHANGING FLOW AND WARMISH AIR ALOFT WITH
H85 TEMPS BETWEEN -5 TO -8C LOOK TO KEEP A MAJOR DAMPER OF ANY LAKE
ENHANCEMENT. SNOW MAY BE ALSO BE SLOW TO ACCUMULATE ON ROAD SURFACES
WITH SURFACE TEMPS AT OR SLIGHTLY ABOVE FREEZING...WITH THE MORE
AGGRESSIVE NAM/GFS SUGGESTING HIGHS IN THE MID TO UPPER 30S FOR
THURSDAY. THIS WOULD HAVE RAIN/SNOW MIX IMPLICATIONS FOR THE LOWER
ELEVATIONS OF THE CWA...BUT PREFER THE MORE COOLER...LESS AMPLIFIED
SOLUTIONS FOR NOW.

THURSDAY NIGHT AND FRIDAY...FORCING BEGINS TO PUSH EAST OF THE AREA
BY LATE THURSDAY AFTERNOON WITH STRONG COLD AIR ADVECTION ENSUING
ACROSS THE CWA THURSDAY NIGHT INTO FRIDAY. THIS WILL RAMP UP THE
LAKE EFFECT SNOW MACHINE DURING THIS TIMEFRAME. MODELS ARE NOT IN
THE BEST AGREEMENT WITH THE NAM/GFS MORE NORTHWESTERLY THAN THE NNW
FLOW DEPICTED BY THE ECMWF. MODEST INVERSION HEIGHTS AND DEEPEST
MOISTURE MOVING OUT SHOULD KEEP MAJOR LAKE SNOW ACCUMULATIONS IN
CHECK...HOWEVER SEVERAL INCHES OF ACCUMULATION LOOK LIKELY FOR THE
NW/NNW FAVORED SNOW BELTS THROUGH FRIDAY. H85 TEMPS FALL TO -15 TO
-18C DURING THE DAY FRIDAY...WITH MODEL CONSENSUS SHOWING HIGHS
STRUGGLING TO MAKE IT OUT OF THE TEENS.

FRIDAY NIGHT THROUGH TUESDAY...CHILLY CONDITIONS ENSUE AS DEEP
TROUGH SETTLES INTO THE GREAT LAKES WITH MODEL CONSENSUS SHOWING H85
TEMPS IN THE -18 TO -22 RANGE ACROSS THE GREAT LAKES INTO THE DAY ON
SATURDAY. CERTAINLY PLENTY OF INSTABILITY TO KEEP THE LAKE EFFECT
SNOW MACHINE GOING...WITH POCKETS OF DEEPER H85-H7 MOISTURE
ASSOCIATED WITH EMBEDDED SHORTWAVES ROUNDING THE LONGER WAVE TROUGH
AND CONTINUED NORTHWEST TO NORTH NORTHWEST FLOW. AT THE
LEAST...SEVERAL INCHES OF ACCUMULATION LOOK LIKELY IN THE NW TO NNW
FAVORED SNOW BELTS WITH THIS PATTERN. LOOKING AT SOME OF COOP
SNOWFALL GUIDANCE FROM THE CIPS ANALOGS FOR THE 72 HOUR PERIOD
CENTERED ON 00Z/17 SHOWS HEAVY ACCUMULATIONS FOR 3 OF THE TO 5
ANALOGS. STILL PLENTY OF DETAILS TO WORK OUT BETWEEN NOW AND THIS
WEEKEND...WITH ICE COVER OVER NORTHERN LAKE MICHIGAN AND MODEST
INVERSION HEIGHTS SERVING AS MITIGATING FACTORS FOR HEAVY
ACCUMULATIONS. STILL COULD SEE THE POSSIBILITY OF SOME HEADLINES FOR
THE FRI/SAT TIMEFRAME...AND WILL MAINTAIN THE THREAT FOR
ACCUMULATING LAKE SNOWS IN THE HWO.

SUNDAY THROUGH MONDAY...PROGRESSIVE PATTERN CONTINUES WITH DEEP
TROUGH KICKING OFF TO THE NORTHEAST AND HEIGHTS MODIFYING
SUBSTANTIALLY AS UPSTREAM RIDGING BUILDS INTO THE GREAT LAKES.
1000-850 MEAN FLOW IS PROGGED TO BACK TO THE SOUTHWEST WITH H85
TEMPS MODIFYING ENOUGH TO END THE LES THREAT...ALTHOUGH THERE MAY BE
SOME LINGER -SHSN FOR SW FAVORED FLOW AREAS INITIALLY SUNDAY
MORNING. ANOTHER CLIPPER SYSTEM LOOKS TO TRAVERSE THE AREA SUNDAY
NIGHT INTO MONDAY...HOWEVER THE BETTER MOISTURE AND FORCING LOOK TO
REMAIN OVER THE NORTHERN PORTION OF THE CWA ATTM.

MONDAY NIGHT INTO TUESDAY...NEXT TROUGH BUILDS INTO THE GREAT LAKES
WITH GFS/ECMWF DEPICTING A STORM SYSTEM DEVELOPING IN THE SOUTHERN
PLAINS AND MOVING UP THROUGH THE OHIO VALLEY INTO THE GREAT LAKES.
NOT A LOT OF CONFIDENCE OF COURSE THIS FAR OUT...ESPECIALLY WHEN
LOOKING AT SOME OF THE ENSEMBLE GUIDANCE ON THE UPPER AIR
PATTERN...BUT SOME SIGNALS ARE THERE OF SAID SYSTEM WHEN LOOKING AT
THE REANALYSIS BASED ON THE TOP GFS/CAN ENS TOP ANALOGS. SOMETHING
THAT WILL CERTAINLY NEED TO BE MONITORED.

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1237 PM EST TUE FEB 12 2013

ABUNDANT MVFR PRODUCING STCU DECK CONTINUES TO ROTATE OFF LAKE
MICHIGAN...OVERSPREADING ALL TAF SITES. CLOUD FIELD CONTINUES TO
PRODUCE WIDESPREAD FLURRIES ACROSS WESTERN TAF SITES. FLOW VEERS
SLOWLY AROUND TO SOUTHWEST...WITH LIGHT SOUTHWEST WINDS CONTINUING
TONIGHT INTO WEDNESDAY MORNING. THIS SHOULD TARGET BEST FLURRY
ACTIVITY ACROSS KPLN TONIGHT AND WEDNESDAY MORNING. OTHERWISE...STCU
MVFR DECK SHOULD CONTINUE AS MOISTURE REMAINS TRAPPED BELOW STRONG
INVERSION. SOME POTENTIAL FOR CLEARING OUTSIDE OF KPLN
OVERNIGHT...BUT NOT CONFIDENT ENOUGH TO GO THAT DIRECTION JUST
YET.

.MARINE...
ISSUED AT 415 PM EST TUE FEB 12 2013

MARINE...VEERING WINDS TO SOUTHWEST REMAIN SOMEWHAT GUSTY HEADING
INTO THIS EVENING. MAY EVEN SEE SOME SCA PRODUCING GUSTS ALONG THE
NORTHWEST LOWER LAKE MICHIGAN COAST...ALTHOUGH DURATION DOES NOT
SUPPORT A SPECIFIC SCA HEADLINE. SOUTHWEST AND SUB-ADVISORY WINDS TO
CONTINUE THROUGH THURSDAY MORNING.

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.

SYNOPSIS...SR
SHORT TERM...MB
LONG TERM...NS
AVIATION...MB
MARINE...MB

AREA FORECAST DISCUSSION

NWS MARQUETTE MI

1204 AM EST TUE FEB 12 2013

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 406 PM EST MON FEB 11 2013

PER WATER VAPOR IMAGERY AND RUC ANALYSIS...BROAD MID LEVEL TROUGH
AND ASSOC CLOSED LOW ARE PROGRESSING STEADILY EAST OF THE UPPER
GREAT LAKES. IN RESPONSE TO INCREASED RDGG FROM THE WEST...MODELS
INDICATE INCREASING Q-VECT DIV/SUBSIDENCE SPREADING WEST TO EAST
ACROSS FCST AREA INTO THIS EVENING. COMBINATION OF MQT RADAR...VIS
SATELLITE AND AREA WEB CAMS SUGGEST ONLY LIGHT SNOW OR FLURRIES
ACROSS THE CWA. THERE IS A BETTER BAND OF LES OVER WRN LAKE SUPERIOR
AFFECTING NW WI THIS AFTERNOON WITH LIGHT TO MODERATE SNOW PER DLH
RADAR.

GIVEN THAT DEEPER MOISTURE WILL EXIT EAST TONIGHT WITH FLOW BCMG
INCREASINGLY ANTICYCLONIC...SNOW NEAR LAKE SUPERIOR SHOULD STEADILY
DIMINISH W TO E (POSSIBLY EVEN END) AS 850MB TEMPS WILL BE MARGINAL
AROUND THE THRESHOLD FOR LES. AS A RESULT OF CONTINUED DIMINISHING
TREND TO LES...EXPECT TO CANCEL REMAINING WINTER WX ADVISORIES OVER
WRN COUNTIES ON THE AFTERNOON FCST ISSUANCE. EVEN IF BAND OVER NW WI
DOES SWING INTO FAR WRN UPR MI...BELIEVE ANY INCREASE IN LES WILL BE
SHORT-LIVED AND NOT BE WORTHY OF ADVISORY HEADLINE.

LINGERING LIGHT LAKE EFFECT IS EXPECTED EAST TUE MORNING...BUT
INCREASED DRYING/RDGG FROM WEST TO EAST...WARMING 850MB TEMPS AND
WINDS BACKING TO THE SOUTHWEST WITH THE SURFACE RIDGE MOVING ACROSS
THE REGION SHOULD QUICKLY DIMINISH OR END LAKE EFFECT SNOW DURING
THE DAY TUESDAY. EXPECT CLOUDS TO GENERALLY DIMINISH AS WELL THROUGH
THE DAY WITH INCREASED RDGG. GENERALLY FOLLOWED A BLEND OF CONSENSUS
MODEL GUIDANCE FOR LOW TEMPS TONIGHT AND HIGH TEMPS ON TUESDAY.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 406 PM EST MON FEB 11 2013

EXPECT NW FLOW ALOFT THROUGH MUCH OF THE LONG TERM PERIOD...WITH
SEVERAL OPEN WAVES DIVING TOWARD THE UPPER GREAT LAKES. LAKE EFFECT
SNOW SHOWERS OVER THE KEWEENAW PENINSULA...AND NEAR AND EAST OF
MUNISING NEAR LAKE SUPERIOR WILL BE COMMON.

THE NEXT SYSTEM TO INFLUENCE OUR WEATHER WILL BE IN THE FORM OF A
SFC TROUGH EXTENDING FROM THE PARENT LOW OVER HUDSON BAY. THE TROUGH
WILL SWEEP W-E ACROSS UPPER MI TUESDAY NIGHT...BEFORE EXITING TO
EASTERN ONTARIO LATE WEDNESDAY MORNING. 850MB TEMPS OF -7 TO -10C.

YET ANOTHER QUICK CLIPPER SYSTEM SET UP OVER CENTRAL ALBERTA AND
SASKATCHEWAN TUESDAY NIGHT WILL QUICKLY CROSS LAKE WINNIPEG
WEDNESDAY MORNING...AND PUSH INTO WESTERN LAKE SUPERIOR WEDNESDAY
EVENING...THEN ACROSS CENTRAL UPPER MI/LAKE SUPERIOR BY 12Z
THURSDAY...AND EASTERN UPPER MI AROUND 18Z. WHILE THE
NAM/GFS/ECMWF/SREF SHOW A SIMILAR TRACK TO THE SFC LOW...THE 11/00Z
CANADIAN IS APPROX 300MI SW OF THE CONSENSUS. WILL LIMIT THE USE OF
THE 11/00Z CANADIAN FORECAST FOR WEDNESDAY THROUGH THURSDAY. SNOW
AMOUNTS WEDNESDAY NIGHT THROUGH THURSDAY COULD ACCUMULATE 3 TO 6
INCHES OF LES FROM IWD UP THROUGH THE KEWEENAW PENINSULA...WITH SNOW
TO LIQUID RATIOS AROUND 17:1. LIGHTER AMOUNTS OF 2 TO 5 INCHES WILL
BE POSSIBLE NORTH CENTRAL...AND 1 TO 3 INCHES ELSEWHERE. WILL ADD
THE MENTION OF LIGHT TO MODERATE SNOW WITH LAKE ENHANCEMENT FOR
WEDNESDAY NIGHT THROUGH THURSDAY...BEFORE THE DGZ FALLS CLOSER TO
THE SFC AS COLDER AIR PUSHES IN...LIMITING SIGNIFICANT ACCUMULATIONS.

A WEAKENING SFC TROUGH WILL AGAIN LINGER ACROSS CENTRAL AND EASTERN
LAKE SUPERIOR THURSDAY NIGHT THROUGH SATURDAY AS STRONGER HIGH
PRESSURE SINKS ACROSS THE CENTRAL CANADA AND THE PLAINS
STATES...WITH A RIDGE EDGING INTO WESTERN UPPER MI/LAKE SUPERIOR.
THE 11/12Z GFS WAS A BIT STRONGER WITH WHAT THE ECMWF HAS AS AN OPEN
WAVE PUSHING IN FROM THE NNW SATURDAY...ACCENTUATING THE SFC LOW
OVER EASTERN LAKE SUPERIOR. EITHER WAY...LAKE EFFECT SNOW SHOWERS
WILL BE LINGERING OVER CENTRAL AND EASTERN UPPER MI NEAR LAKE
SUPERIOR. EXPECT LES TO PICK UP SIGNIFICANTLY THURSDAY AFTERNOON AND
EVENING AS COLDER AIR FILTERS IN BEHIND THE EXITING LOW ON FAVORABLE
NNW WINDS. 850MB TEMPS WILL FALL TO AROUND -17C OVER THE W HALF BY
THE END OF THE DAY THURSDAY...WITH FURTHER COOLING TO -19 TO -20C
THROUGH THE START OF THE WEEKEND. -22 TO -24C LOOKS TO BE THE
COOLEST POINT...SATURDAY AFTERNOON.

WHILE THE 11/06Z GFS AND 11/00Z ECMWF ARE PRETTY CONSISTENT UNTIL
SATURDAY...THEY BEGIN TO DIVERGE SATURDAY AFTERNOON...WITH THE GFS
DEVELOPING A LOW OVER THE CENTRAL PLAINS BECOMING OUT OF PHASE WITH
THE REST OF THE AVAILABLE MODELS. THE GOOD NEWS IS THAT THE 11/12Z
GFS LOOKS TO HAVE FIXED THIS POTENTIAL PROBLEM...AND ANOTHER
POSSIBLE STORM TOWARD THE EAST COAST FOR THE UPCOMING WEEKEND.
EXPECT A COOL RIDGE OF HIGH PRESSURE TO EDGE ACROSS THE UPPER GREAT
LAKES FOR THE WEEKEND...AS AN ELONGATED TROUGH GAINS STEAM FROM
CENTRAL CANADA THROUGH THE CENTRAL PLAINS STATES ON SUNDAY. FOR
MONDAY IT WILL BE A QUESTION AS TO IF THE SOUTHERN OR NORTHERN
STREAM WINS OUT. AT THIS POINT THE 11/00Z ECMWF LOOKS TO BE STRONGER
WITH THE SYSTEM AS A WHOLE...BUT WILL WAIT UNTIL THE TIME PERIOD
BECOMES A BIT MORE CLEAR BEFORE LEANING TO ONE SOLUTION OVER ANOTHER.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1203 AM EST TUE FEB 12 2013

MAINLY MVFR CONDITIONS ARE EXPECTED OVERNIGHT WITH CONTINUED
MOIST NW FLOW AND MINOR LAKE EFFECT SNOW/FLURRIES IN NORTHERN UPPER
MICHIGAN BEHIND THE DEPARTING LOW PRESSURE SYSTEM. MVFR CIGS COULD
SCATTER LATE IN THE NIGHT AT IWD AS WINDS BACK TOWARD THE SW...AND
PERHAPS AT KSAW UNDER DOWNSLOPING W TO NW WINDS. OTHERWISE...LOOK
FOR MVFR CIGS TO SCT OUT AT BOTH KCMX AND KSAW BY LATE MORNING WITH
INCREASED SUBSIDENCE AND RDGING.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EST MON FEB 11 2013

NW GALES OVER CENTRAL LAKE SUPERIOR AIDED BY PRES RISE MAX WILL
DIMINISH BLO GALES BY LATE EVENING AS NW GRADIENT WEAKENS DUE TO LOW
DEPARTING EAST AND RDG BUILDING IN FM WEST. HIGH PRES RDG AXIS MOVG
EAST ACROSS THE LAKE WILL KEEP WINDS AOB 20 KTS OVER EAST HALF OF
LAKE SUPERIOR. WEST HALF AND FAR NCNTRL LAKE SHOULD SEE AN INCREASE
IN SW WINDS TUE AFTERNOON TO 25 KTS WITH TIGHTENING GRAD ON BACKSIDE
OF RDG AXIS.

A WEAK TROUGH STRETCHING FROM HUDSON BAY THROUGH THE UPPER GREAT
LAKES TUESDAY NIGHT WILL BE REINFORCED BY ANOTHER LOW FROM THE
NORTHWEST...THAT WILL PUSH ACROSS LAKE SUPERIOR/UPPER MI THURSDAY
MORNING INTO THURSDAY AFTERNOON...BEFORE QUICKLY EXITING INTO
SOUTERN ONTARIO AND QUEBEC THURSDAY AFTERNOON/EVENING. A FEW N GALE
FORCE GUSTS TO 35KTS WILL BE POSSIBLE THURSDAY AFTERNOON ACROSS
MAINLY CENTRAL LAKE SUPERIOR...WITH HEAVY FREEZING SPRAY OVER MUCH
OF THE LAKE THURSDAY NIGHT. WHILE A WEAKENING TROUGH OF LOW PRESSURE
REMAINS OVER EASTERN LAKE SUPERIOR...HIGH PRESSURE WILL SLOWLY BUILD
IN FROM THE WEST THORUGH SATURDAY.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

SHORT TERM...VOSS
LONG TERM...KF
AVIATION...JLB
MARINE...VOSS/KF

AREA FORECAST DISCUSSION...UPDATED

NWS GRAND FORKS ND

846 PM CST WED FEB 13 2013

.DISCUSSION...
FIRST BAND OF SNOW IS SLOWLY MOVING SOUTH-SE OF THE FARGO MOORHEAD
AREA. HAVE GENERALLY HAD REPORTS OF 1 TO 4 INCHES IN THIS AREA.
DO HAVE SLICK ROADS IN THE FARGO AREA DUE TO THE WARM SFC TEMPS
AND THE FALLING SNOW. NEXT UPSTREAM SNOW BAND IS NOW STARTING TO
REACH INTO THE FAR NORTHWEST FA. LATEST MODEL GUIDANCE SEEMS
CONSISTENT IN KEEPING THIS BAND ACROSS THE WEST AND SOUTHWEST FA.
AS FAR AS AMOUNTS GO IT LOOKS LIKE ANOTHER INCH OR TWO IN THIS AREA.
THINK THE EASTERN PERIPHERY OF THE WINTER WEATHER ADVISORY MAY NOT
GET MUCH FROM THIS NEXT BAND...INCLUDING THE FARGO MOORHEAD AREA
DOWN THRU KFFM. HOWEVER WITH SNOW STILL FALLING DO NOT WANT TO
TRIM ANY COUNTIES FROM THE CURRENT ADVISORY AT THIS POINT.

.AVIATION...
KFAR AND KDVL WILL BE ON THE FRINGES OF THE NEXT SNOW BAND WHICH
MAY BRING SOME LIGHT SNOW AND LOWER CEILINGS. OTHERWISE THE OTHER
3 TAF SITES SHOULD REMAIN VFR. EXPECT INCREASING NORTH WINDS THU
MORNING WHICH SHOULD LAST THRU THE DAY.

.PREV DISCUSSION... /ISSUED 308 PM CST WED FEB 13 2013/

SHORT TERM...
CHALLENGE FOR THE PERIOD INCLUDE SNOW TODAY AND TONIGHT WITH
CLIPPER SYSTEMS AND THEN TEMPS THRU SATURDAY. MODELS IN OVERALL
GENERAL AGREEMENT WITH 12Z RUNS. 12Z GFS CAME AROUND IN AGREEMENT
WITH THE OVER MODELS WITH THE PLACEMENT OF TODAYS QPF. PRIMARILY
USED NAM/ECMWF FOR THE PACKAGE WITH A HEAVY LEAN TO THE RAP THRU
THIS EVENING.

CLIPPER CURRENTLY CROSSING THE CWFA IS PRODUCING VSBYS GENERALLY 1
TO 2 MILES WITH 1/2 MI IN THE STRONGEST SN. BACK EDGE OF CLIPPER
SNOW BAND JUST EXITING MINOT AREA. WILL CONTINUE WINTER WX ADVISORY
AS NEXT CLIPPER IS EXPECTED TO MOVE INTO THE DVL BSN THIS EVENING AND
STAY CONFINED TO THE WESTERN AND EXTREME SOUTHERN PORTIONS OF THE
CWFA. TOTAL 24 HOUR SNOWFALL WITH A 14 TO 1 RATIO IN THE QUARTER
TO HALF INCH QPF WILL BE IN THE 2 TO 5 INCH RANGE WITH A HIGHER
TOTAL ALONG A MADDOCK TO NEW ROCKFORD TO VALLEY CITY TO LISBON
LINE.

THE NEXT CONCERN WOULD BE WIND POTENTIAL ON THE BACK SIDE WITH BLOWING
SNOW IMPACTS. BEST COLD ADVECTION WILL LAG THE PRECIP BAND. NAM
INDICATES THE STRONGEST COLD PUSH OCCUR IN THE DVL BASIN AND ACROSS
THE WESTERN PORTIONS OF THE CWFA OVERNIGHT. THOUGH LOW LEVEL WINDS
ARE RELATIVELY WEAK WITH A SHALLOW MIXED LAYER JUST 10 TO 15 KTS
THROUGH 12Z. AS A RESULT LITTLE BLOWING SNOW IS EXPECTED.

MIXED LAYER INCREASES TOMORROW WITH BETTER MIXING...TO 20KTS TO
950MB TO 20KTS AS COLD AIR PUSHES IN WITH 925 TEMPS DROPPING 10 C
OR SO CAUSING DAYTIME TEMPS THURSDAY TO REMAIN FAIRLY STEADY OR EVEN
FALL THROUGH THE AFTERNOON.

SFC HIGH PRESSURE TO SLIDE ACROSS THE AREA FIR DAY WITH NW FLOW
ALOFT. COLD START AS NEGATIVE VALUES RETURN FOR MORNING LOWS.
LITTLE MIXING WILL LEAD TO SLOW TEMP RECOVERY FRIDAY. RETURN FLOW
SETS UP FRI AFTERNOON WEST AND WILL HELP OFFSET DIURNAL COOLING
VALLEY WEST FRIDAY NIGHT. TEMPERATURE MODERATION CONTINUES
SATURDAY AS WAA INCREASES WITH HIGHS IN THE TEENS AND 20S WEST.

LONG TERM (SAT NIGHT-WED)...
MODELS IN REASONABLE AGREEMENT. NEXT SHORT WAVE MOVES THROUGH
SUNDAY AFTERNOON AND NIGHT. 12Z ECMWF IS COMING IN A BIT DEEPER
WITH 500 MB TROUGH AND FARTHER SOUTH WITH SFC LOW WHICH WOULD BE A
BIT HIGHER SNOW CHANCES OVER THE AREA THAN GFS/GEM. BEHIND THIS
SHORT WAVE THERE WILL BE STRONG COLD ADVECTION WITH 850 MB TEMPS
DROPPING INTO THE -18C TO -22C RANGE TUE-WED. CR ALL BLEND TEMPS
LOOK REASONABLE WITH HIGHS IN THE SINGLE DIGITS TUES-WED AND LOWS IN
THE 5 TO 15 BELOW RANGE. DISAGREEMENTS DO SHOW UP VERY LATE IN THE
PD FOR WED NIGHT-THU IN REGARDS TO NEXT 500 MB SYSTEM DIGGING INTO
THE CNTRL-SOUTHERN ROCKIES AND HOW FAR NORTH ITS IMPACT IS. GFS
WETTER AND FARTHER NORTH.

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 9 AM CST THURSDAY FOR NDZ006-014-
015-024-026-028>030-038-039-049-052-053.

MN...WINTER WEATHER ADVISORY UNTIL 9 AM CST THURSDAY FOR MNZ003-
029>031-040.

GODON

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

922 AM EST TUE FEB 12 2013

.SYNOPSIS...
A GUSTY WESTERLY FLOW WILL PREVAIL TODAY BEFORE A WEAK AREA OF
HIGH PRESSURE ARRIVES TONIGHT. LOW PRESSURE MOVING THROUGH THE
GULF COAST STATES EARLY WEDNESDAY WILL TRACK NORTHEAST TO A
POSITION OFF THE DELMARVA PENINSULA BY LATE WEDNESDAY NIGHT.
CONFIDENCE IS INCREASING ON A LIGHT TO MODERATE SNOW ACCUMULATION
ACROSS SOUTH-CENTRAL PENNSYLVANIA WITH THIS SYSTEM. THE WEATHER
PATTERN IS EXPECTED TO TURN COLDER INTO THE UPCOMING WEEKEND.

.NEAR TERM /THROUGH TONIGHT/...

EARLY VIZ SHOTS SHOW A TYPICAL POST COLD FRONTAL SHIELD OF STRATO-
CU ALONG WITH SOME LIGHT SNOW SHOWERS OVER THE NW. EXPECTING SLOW
IMPROVEMENT TODAY AS WEAK HIGH PRESSURE BEGINS TO MAKE INROADS
INTO THE REGION...SO NO SIG CHANGES MADE TO THE FCST WITH THIS
UPDATE.

PREVIOUS DISCUSSION...

SHRTWV TROUGH AXIS WILL ROTATE ACRS N-CENTRAL PA EARLY THIS
MORNING. LOW-LEVEL CAA/STEEP LAPSE RATES AND WLY TRAJECTORY WILL
SUPPORT OCNL UPSLOPE -SHSN OVER THE ALLEGHENY PLATEAU/NW MTNS EARLY
TODAY. LITTLE TO NO ACCUM EXPECTED. RAP BUFKIT SOUNDINGS SHOW
INVERSION HGTS LOWERING THRU THE MORNING...WITH INCREASING
SUBSIDENCE IN WAKE OF SHRTWV/AREA OF HIGH PRES DRIFTING ENEWD FROM
THE MID OH VLY. THIS SHOULD BRING AN END TO -SHSN ACTIVITY AROUND
MID-DAY WITH JUST SOME SCT FLURRIES EXPECTED TO LINGER OVER THE NW
MTNS INTO THE AFTN.

THE LOW-LEVEL CAA/STEEP LAPSE RATES WILL MAINTAIN GUSTY WLY WINDS
INTO THE AFTN. THE WIND ADVY HAS BEEN ALLOWED TO EXPIRE. IN
GENERAL...RAP SOUNDINGS SHOW PEAK GUSTS MAINLY IN THE 30-35KT
RANGE WITH LOCALLY HIGHER GUSTS PSBL ON THE RIDGES.

BKN-OVC STRATOCU WILL COVER THE N/W MTNS THRU THE AFTN WITH TEMPS
IN THE LOW TO MID 30S. DOWNSLOPE FLOW E OF THE ALLEGHENY FRONT
SHOULD HELP TO PROVIDE PARTLY TO MOSTLY SUNNY SKIES OVER THE
CENTRAL RIDGE/VALLEY REGION AND SUSQ VLY...WITH TEMPS VARYING FROM
THE UPPER 30S TO LOW 40S.

WEAK HIGH PRES WILL DRIFT NEWD OVER THE AREA TONIGHT WITH M/CLR
SKIES...LGT WINDS AND TEMPS MAINLY IN THE 20S. MID-HIGH LVL CLOUDS
SHOULD BEGIN TO INCREASE FROM THE SOUTH BY DAYBREAK WED.

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
WEAK SFC HIGH OVER EAST CENTRAL PA WILL RETREAT NEWD BY WEDNESDAY
NIGHT AS A FAIRLY DISORGANIZED AREA OF LOW PRESSURE TRACKS OFF OF
THE NC COAST AND OUT TO SEA WELL SOUTH OF LONG ISLAND AND CAPE
COD. MAIN CHALLENGE FOR THE MEDIUM RANGE WILL BE TO ASCERTAIN THE
IMPACTS OF THIS SYSTEM...AND PARTICULARLY THE NORTHERN EXTENT OF
SIGNIFICANT SNOWFALL WEDNESDAY AFTERNOON AND NIGHT.

00Z DETERMINISTIC GUIDANCE COUPLED WITH 00Z GEFS EXAMINATION SHOWS
A REASONABLE LIKELIHOOD OF ADVISORY CRITERIA SNOWFALL ACROSS THE
SOUTHERN HALF OF CENTRAL PA. MARGINAL BOUNDARY LAYER TEMPERATURES
AT THE ONSET OF PRECIPITATION WEDNESDAY AFTERNOON WILL CUT DOWN ON
ACCUMS AND IF MEAN QPF WEREN`T A LIMITING FACTOR TO RULE OUT A
WATCH AT THIS TIME...MARGINAL PBL TEMPERATURES WOULD BE...THUS NO
WATCHES AT THIS TIME.

AGAIN WENT WITH A BLEND OF OPERATIONAL GUIDANCE AND ENSEMBLE
MEANS AT HAND...PRODUCING A MAINLY LIGHT SNOWFALL WED AFTN AND
NIGHT. NCEP WWD GRAPHICS DEPICT A 3-6 INCH STRIPE OVER MY
SOUTHEAST COUNTIES WHICH I THINK IS SLIGHTLY OVERDONE GIVEN THE
MELTING EXPECTED TO OCCUR AT THE ONSET. SNOW SHOULD BEGIN LATE
WEDNESDAY AFTERNOON ACROSS THE SWRN HALF OF THE CWA /POSSIBLY
MIXED WITH SOME RAIN/...THEN SPREADING NORTH AND EAST AT NIGHT.

00Z GFS AND NAM12 IN REMARKABLE AGREEMENT ON PLACEMENT OF 0.25"
QPF CONTOUR...FROM KJST TO KAOO EASTWARD TO KMDT. AREAS SOUTH WILL
SEE UP TO .5" W.E. AND WILL AGAIN DEAL WITH MELTING FROM
MARGINALLY COLD BOUNDARY LAYER/SFC TEMPS. THE MAGNITUDE OF THIS
EVENT WOULD BE SOLIDLY IN THE ADVISORY RANGE.

.LONG TERM /THURSDAY THROUGH MONDAY/...
AMPLIFIED SPLIT-FLOW UPPER PATTERN IS FORECAST TO PERSIST THROUGH
THE LONG TERM PERIOD ACROSS MUCH OF NORTH AMERICA. SIGNIFICANT
PHASING OF THESE BRANCHES FOR A BRIEF TIME OVER THE UPCOMING
WEEKEND...WILL USHER IN A BLAST OF VERY COLD AIR WITH TRAJECTORIES
RIGHT FROM THE ARCTIC CIRCLE.

A BRIEF PERIOD OF ZONAL FLOW ALOFT AND WEAK SFC HIGH PRESSURE WILL
BRING FAIR/MAINLY DRY WEATHER FOR THURSDAY...BEFORE A STRONG NRN
STREAM SHORTWAVE AND ASSOCIATED 135 KT...300 MB JET DIVER SEWRD TO
CARVE OUT A HIGH AMPLITUDE TROUGH ACROSS THE EASTERN THIRD OF THE
U.S. FOR THE WEEKEND. EC SHOWS 500 MB TEMPS FROM THE OHIO VALLEY TO
PENN DIVING TO PERHAPS THE COLDEST VALUES OF THE WINTER SEASON...OR
AROUND -42C. 850 MB TEMPS MAY DROP TO -16-20C. WEST TO NW MEAN LLVL
FLOW AND THE HIGHLY ANOMALOUS COLD AIR IMPLIES A SIGNIFICANT AND
PROLONGED LES/UPSLOPE SNOW EVENT FOR THE WRN MTNS AND LAKE ERIE
SNOWBELT COUNTIES.

BROAD UPPER TROFFING OVER THE EASTERN U.S. WILL LEAD TO YET
ANOTHER EAST COAST CYCLONE LATER IN THE WEEKEND. AT THIS POINT
IN TIME...THE TRACK IS WELL OFFSHORE...AT LEAST CONCERNING AFFECTS
ON PA. WRAP AROUND FLOW IS EVEN SIGNIFICANTLY
NORTHERLY...PREVENTING WIDESPREAD LAKE EFFECT SNOW SHOWER ON THE
BACK SIDE. IT HOWEVER WOULD SUPPORT AN EXTENDED COLD SPELL AS WE
HEAD INTO MID FEBRUARY.

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
GUSTY NW FLOW PATTERN WILL BRING THE USUAL LOWER CIGS INTO THE
WRN AIRFIELDS WITH SCT-BKN LOW VFR PREVAILING E OF THE ALLEGHENY
FRONT. EXPECT SFC WIND GUSTS IN THE 25-35KT RANGE THROUGH THE DAY
BEFORE SUBSIDING LATER THIS EVE AND INTO TONIGHT. A WEAK AREA OF
HIGH PRES WILL PROVIDE VFR FLYING TONIGHT WITH MID-HIGH CLOUDS
INCREASING AHEAD OF LOW PRESSURE DEVELOPING OVER THE GULF COAST
STATES. THIS LOW IS EXPECTED TO TRACK ENE TO A POSITION OFF THE
DELMARVA PENINSULA BY EARLY THURSDAY MORNING...WITH A BAND OF SNOW
ON THE NW SIDE OF THE LOW TRACK LKLY IMPACTING S-CENTRAL PA
TERMINALS.

OUTLOOK...

WED...IFR/SN DEVELOPING OVER THE SOUTHERN HALF OF THE AREA.
THU...MVFR/SHSN WEST. BCMG VFR CENTRAL/EAST.
FRI-SAT...MVFR/SHSN WEST. VFR CENTRAL/EAST. GUSTY WNW WINDS.

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

$$
SYNOPSIS...LA CORTE/STEINBUGL
NEAR TERM...LA CORTE/STEINBUGL
SHORT TERM...DEVOIR
LONG TERM...DEVOIR/GARTNER
AVIATION...STEINBUGL

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

705 AM EST TUE FEB 12 2013

.SYNOPSIS...
A GUSTY WESTERLY FLOW WILL PREVAIL TODAY BEFORE A WEAK AREA OF
HIGH PRESSURE ARRIVES TONIGHT. LOW PRESSURE MOVING THROUGH THE
GULF COAST STATES EARLY WEDNESDAY WILL TRACK NORTHEAST TO A
POSITION OFF THE DELMARVA PENINSULA BY LATE WEDNESDAY NIGHT.
CONFIDENCE IS INCREASING ON A LIGHT TO MODERATE SNOW ACCUMULATION
ACROSS SOUTH-CENTRAL PENNSYLVANIA WITH THE MID-WEEK SYSTEM. THE
WEATHER PATTERN IS EXPECTED TO TURN COLDER INTO THE UPCOMING
WEEKEND.

.NEAR TERM /THROUGH TONIGHT/...
12Z UPDATE...NO SIGNIFICANT CHANGES FOR FINAL OVERNIGHT UPDATE.
MINS STAYED MUCH WARMER OVER THE SE ZONES DUE TO CLOUDS AND WINDS.
MESO/SFC OBS STILL INDICATING PEAK GUSTS ARE BLW ADVY CRITERIA BUT
WILL LET THE WIND ADVY RUN ITS COURSE AND EXPIRE AT 9AM.

PREVIOUS DISCUSSION...

THE LOW-LEVEL CAA/STEEP LAPSE RATES WILL MAINTAIN GUSTY WLY WINDS
INTO THE AFTN. THE WIND ADVY LOOKS MARGINAL BASED ON MESONET DATA.
TRIMMED COUNTIES NORTH OF I-80...BUT WILL CONTINUE THE ADVY FOR
THE LAUREL HIGHLANDS/S-CENTRAL MTNS WHERE THE HIGHEST GUSTS ARE
CURRENTLY BEING REPORTED. IN GENERAL...RAP SOUNDINGS SHOW PEAK
GUSTS MAINLY IN THE 30-35KT RANGE WITH LOCALLY HIGHER GUSTS PSBL
ON THE RIDGES.

WEAK HIGH PRES WILL DRIFT NEWD OVER THE AREA TONIGHT WITH M/CLR
SKIES...LGT WINDS AND TEMPS MAINLY IN THE 20S. MID-HIGH LVL CLOUDS
SHOULD BEGIN TO INCREASE FROM THE SOUTH BY DAYBREAK WED.

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
GUSTY NW FLOW PATTERN WILL BRING THE USUAL LOWER CIGS INTO THE
WRN AIRFIELDS WITH SCT-BKN LOW VFR PREVAILING E OF THE ALLEGHENY
FRONT. EXPECT SFC WIND GUSTS IN THE 25-35KT RANGE THROUGH THE DAY
BEFORE SUBSIDING LATER THIS EVE AND INTO TONIGHT. A WEAK AREA OF
HIGH PRES WILL PROVIDE VFR FLYING TONIGHT WITH MID-HIGH CLOUDS
INCREASING AHEAD OF LOW PRESSURE DEVELOPING OVER THE GULF COAST
STATES. THIS LOW IS EXPECTED TO TRACK ENE TO A POSITION OFF THE
DELMARVA PENINSULA BY EARLY THURSDAY MORNING...WITH A BAND OF SNOW
ON THE NW SIDE OF THE LOW TRACK LKLY IMPACTING S-CENTRAL PA
TERMINALS.

OUTLOOK...

WED...IFR/SN DEVELOPING OVER THE SOUTHERN HALF OF THE AREA.
THU...MVFR/SHSN WEST. BCMG VFR CENTRAL/EAST.
FRI-SAT...MVFR/SHSN WEST. VFR CENTRAL/EAST. GUSTY WNW WINDS.

.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ024-025-033-
034.

$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...DEVOIR
LONG TERM...DEVOIR/GARTNER
AVIATION...STEINBUGL

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

519 AM EST TUE FEB 12 2013

.SYNOPSIS...
A GUSTY WESTERLY FLOW WILL PREVAIL TODAY BEFORE A WEAK AREA OF
HIGH PRESSURE ARRIVES TONIGHT. LOW PRESSURE MOVING THROUGH THE
GULF COAST STATES EARLY WEDNESDAY WILL TRACK NORTHEAST TO A
POSITION OFF THE DELMARVA PENINSULA BY LATE WEDNESDAY NIGHT.
CONFIDENCE IS INCREASING ON A LIGHT TO MODERATE SNOW ACCUMULATION
ACROSS SOUTH-CENTRAL PENNSYLVANIA WITH THE MID-WEEK SYSTEM. THE
WEATHER PATTERN IS EXPECTED TO TURN COLDER INTO THE UPCOMING
WEEKEND.

.NEAR TERM /THROUGH TONIGHT/...
SHRTWV TROUGH AXIS WILL ROTATE ACRS N-CENTRAL PA EARLY THIS
MORNING. LOW-LEVEL CAA/STEEP LAPSE RATES AND WLY TRAJECTORY WILL
SUPPORT OCNL UPSLOPE -SHSN OVER THE ALLEGHENY PLATEAU/NW MTNS EARLY
TODAY. LITTLE TO NO ACCUM EXPECTED. RAP BUFKIT SOUNDINGS SHOW
INVERSION HGTS LOWERING THRU THE MORNING...WITH INCREASING
SUBSIDENCE IN WAKE OF SHRTWV/AREA OF HIGH PRES DRIFTING ENEWD FROM
THE MID OH VLY. THIS SHOULD BRING AN END TO -SHSN ACTIVITY AROUND
MID-DAY WITH JUST SOME SCT FLURRIES EXPECTED TO LINGER OVER THE NW
MTNS INTO THE AFTN.

WEAK HIGH PRES WILL DRIFT NEWD OVER THE AREA TONIGHT WITH M/CLR
SKIES...LGT WINDS AND TEMPS MAINLY IN THE 20S. MID-HIGH LVL CLOUDS
SHOULD BEGIN TO INCREASE FROM THE SOUTH BY DAYBREAK WED.

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...

09Z UPDATE...NO CHANGES TO 12/06Z TAFS.

GUSTY NW FLOW PATTERN WILL BRING THE USUAL LOWER CIGS INTO THE WRN
AIRFIELDS WITH SCT-BKN LOW VFR PREVAILING E OF THE ALLEGHENY
FRONT. EXPECT SFC WIND GUSTS IN THE 25-40KT RANGE THROUGH THE DAY
BEFORE SUBSIDING LATER THIS EVE AND INTO TONIGHT. A WEAK AREA OF
HIGH PRES WILL PROVIDE VFR FLYING TONIGHT WITH MID-HIGH CLOUDS
LKLY INCREASING AHEAD OF LOW PRESSURE DEVELOPING OVER THE GULF
COAST STATES. THIS LOW IS EXPECTED TO TRACK ENE TO A POSITION OFF
THE DELMARVA PENINSULA BY EARLY THURSDAY MORNING.

OUTLOOK...

WED...IFR/SN DEVELOPING OVER THE SOUTHERN HALF OF THE AREA.
THU...MVFR/SHSN WEST. BCMG VFR CENTRAL/EAST.
FRI-SAT...MVFR/SHSN WEST. VFR CENTRAL/EAST. GUSTY WNW WINDS.

.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ024-025-033-
034.

$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...DEVOIR
LONG TERM...DEVOIR/GARTNER
AVIATION...STEINBUGL

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

334 AM EST TUE FEB 12 2013

.SYNOPSIS...
A GUSTY WESTERLY FLOW WILL PREVAIL TODAY BEFORE A WEAK AREA OF
HIGH PRESSURE ARRIVES TONIGHT. LOW PRESSURE MOVING THROUGH THE
GULF COAST STATES EARLY WEDNESDAY WILL TRACK NORTHEAST TO A
POSITION OFF THE DELMARVA PENINSULA BY LATE WEDNESDAY NIGHT.
CONFIDENCE IS INCREASING ON A LIGHT TO MODERATE SNOW ACCUMULATION
ACROSS SOUTH-CENTRAL PENNSYLVANIA WITH THE MID-WEEK SYSTEM. THE
WEATHER PATTERN IS EXPECTED TO TURN COLDER INTO THE UPCOMING
WEEKEND.

WEAK HIGH PRES WILL DRIFT NEWD OVER THE AREA TONIGHT WITH M/CLR
SKIES...LGT WINDS AND TEMPS MAINLY IN THE 20S. MID-HIGH LVL CLOUDS
SHOULD BEGIN TO INCREASE FROM THE SOUTH BY DAYBREAK WED.

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
GUSTY NW FLOW PATTERN WILL BRING THE USUAL LOWER CIGS INTO THE WRN
AIRFIELDS WITH SCT-BKN LOW VFR PREVAILING E OF THE ALLEGHENY
FRONT. EXPECT SFC WIND GUSTS IN THE 25-40KT RANGE THROUGH THE DAY
BEFORE SUBSIDING LATER THIS EVE AND INTO TONIGHT. A WEAK AREA OF
HIGH PRES WILL PROVIDE VFR FLYING TONIGHT WITH MID-HIGH CLOUDS
LKLY INCREASING AHEAD OF LOW PRESSURE DEVELOPING OVER THE GULF
COAST STATES. THIS LOW IS EXPECTED TO TRACK ENE TO A POSITION OFF
THE DELMARVA PENINSULA BY EARLY THURSDAY MORNING.

OUTLOOK...

WED...IFR/SN DEVELOPING OVER THE SOUTHERN HALF OF THE AREA.
THU...MVFR/SHSN WEST. BCMG VFR CENTRAL/EAST.
FRI-SAT...MVFR/SHSN WEST. VFR CENTRAL/EAST. GUSTY WNW WINDS.

.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ024-025-033-
034.

$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...DEVOIR/LA CORTE
LONG TERM...DEVOIR/GARTNER
AVIATION...STEINBUGL

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

301 AM EST TUE FEB 12 2013

.SYNOPSIS...
A GUSTY WESTERLY FLOW WILL PREVAIL TODAY BEFORE A WEAK AREA OF
HIGH PRESSURE ARRIVES TONIGHT. LOW PRESSURE MOVING THROUGH THE
GULF COAST STATES EARLY WEDNESDAY WILL TRACK NORTHEAST TO A
POSITION OFF THE DELMARVA PENINSULA BY LATE WEDNESDAY NIGHT.
CONFIDENCE IS INCREASING ON A LIGHT TO MODERATE SNOW ACCUMULATION
ACROSS SOUTH-CENTRAL PENNSYLVANIA WITH THE MID-WEEK SYSTEM. THE
WEATHER PATTERN IS EXPECTED TO TURN COLDER INTO THE UPCOMING
WEEKEND.

WEAK HIGH PRES WILL DRIFT NEWD OVER THE AREA TONIGHT WITH M/CLR
SKIES...LGT WINDS AND TEMPS MAINLY IN THE 20S. MID-HIGH LVL CLOUDS
SHOULD BEGIN TO INCREASE FROM THE SOUTH BY DAYBREAK WED.

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
THE PRIMARY FEATURE OF CONCERN TO BEGIN THIS PERIOD WILL BE LINKED
TO THE NOSE OF A QUITE POWERFUL UPPER JET /IN EXCESS OF 140 KTS/
LIFTING NE UP THE APPALACHIAN MTN CHAIN WEDNESDAY. THE INCREASINGLY
DIFFLUENT UPPER PATTERN ACROSS THE MID ATLANTIC REGION LATER WED AND
WED NIGHT...WILL COMBINE WITH A SLIGHTLY ANOMALOUS SERLY LLVL FLOW
AND APPROX 1000 MB SFC LOW PRESSURE CONSOLIDATING/TRACKING RIGHT
ACROSS THE DELMARVA REGION AROUND 06Z THURSDAY.

SREF AND GEFS PLUMES /OVER THE PAST FEW DAYS/ HAVE GRADUALLY TRENDED
TOWARD HIGHER QPF AMTS IN THE FORM OF MAINLY SNOW. EC...CANADIAN AND
UKMET ALSO HAVE DISPLAYED A GRADUAL NWD SHIFT TO THE TRACK OF THEIR
SFC LOW.

USING A BLEND OF ALL THE OPERATIONAL GUIDANCE AND ENSEMBLE MEANS AT
HAND PRESENTS US WITH A FAIRLY GOOD CHANCE OF A LIGHT TO MODERATE
SNOW EVENT BEGINNING LATE WEDNESDAY AFTERNOON ACROSS THE SWRN HALF
OF THE CWA /POSSIBLY MIXED WITH SOME RAIN/...THEN SPREADING NORTH
AND EAST AT NIGHT.

NUMEROUS SREF AND GEFS PLUMES INDICATE SIGNIFICANT QPF /AOA 0.50 OF
AN INCH/ IN THE FORM OF SNOW. SREF/S MEAN 12 HOUR QPF IS AROUND 0.50
ACROSS THE EXTREME SE PART OF THE CWA...WITH THE 0.25 INCH LIQUID
EQUIVALENT LINE EXTENDING ALONG MUCH OF INTERSTATE 80 IN CENTRAL
PA...THEN ACROSS THE NRN POCONOS.

THE 06Z NAM CONTINUES TO TREND TWD HIGHER QPF AS THE MOST AGGRESSIVE
MODEL SOLUTION ATTM...AND COMPARABLE WITH SEVERAL OF THE 03Z SREF/
00Z GEFS PLUMES. THE NAM/S 24-HOUR QPF /FROM ITS APPARENT MILLER B
TYPE STORM/ IS AROUND 0.25 INCH ACROSS THE NRN TIER OF PENN...ABOUT
0.50 NEAR I-80...AND OVER 0.75 OF AN INCH ACROSS PORTIONS OF THE
LOWER SUSQ REGION.

THIS MAGNITUDE OF AN EVENT WOULD BE SOLIDLY IN THE ADVISORY
RANGE...WITH POSSIBLY BORDERLINE WINTER STORM WARNING AMOUNTS ACROSS
THE SRN HALF OF THE CWA.

AT THIS POINT...CONSIDERING MUCH UNCERTAINTY WITH RESPECT TO THE
EXACT SECONDARY LOW DEVELOPMENT NEAR THE VA COAST...AND INTERACTION
OF THE NRN AND SRN STREAM WAVES...ITS PRUDENT TO RAMP UP THE SNOW
PROBABILITIES AND AMOUNTS GRADUALLY...AND HEIGHTEN AWARENESS IN OUR
HAZARDOUS WEATHER OUTLOOK /PHLHWOCTP/.

.LONG TERM /THURSDAY THROUGH MONDAY/...
1016-1018 MB SFC HIGH PRESSURE BUILD NEWD ACROSS THE STATE TUESDAY
NIGHT WITH FAIR SKIES...LIGHT WIND...AND CHILLY TEMPS MAINLY IN THE
20S.

A FAIRLY AMPLIFIED...SPLIT-FLOW UPPER PATTERN IS FORECAST TO PERSIST
THROUGH THE LONG TERM PERIOD ACROSS MUCH OF NORTH AMERICA.
SIGNIFICANT PHASING OF THESE BRANCHES FOR A BRIEF TIME OVER THE
UPCOMING WEEKEND...WILL USHER IN A BLAST OF VERY COLD AIR WITH
TRAJECTORIES RIGHT FROM THE ARCTIC CIRCLE.

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
GUSTY NW FLOW PATTERN WILL BRING THE USUAL LOWER CIGS INTO THE WRN
AIRFIELDS WITH SCT-BKN LOW VFR PREVAILING E OF THE ALLEGHENY
FRONT. EXPECT SFC WIND GUSTS IN THE 25-40KT RANGE THROUGH THE DAY
BEFORE SUBSIDING LATER THIS EVE AND INTO TONIGHT. A WEAK AREA OF
HIGH PRES WILL PROVIDE VFR FLYING TONIGHT WITH MID-HIGH CLOUDS
LKLY INCREASING AHEAD OF LOW PRESSURE DEVELOPING OVER THE GULF
COAST STATES. THIS LOW IS EXPECTED TO TRACK ENE TO A POSITION OFF
THE DELMARVA PENINSULA BY EARLY THURSDAY MORNING.

OUTLOOK...

WED...IFR/SN DEVELOPING OVER THE SOUTHERN HALF OF THE AREA.
THU...MVFR/SHSN WEST. BCMG VFR CENTRAL/EAST.
FRI-SAT...MVFR/SHSN WEST. VFR CENTRAL/EAST. GUSTY WNW WINDS.

.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ004>006-
010>012-017-018-024-025-033-034.

$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...FITZGERALD/LA CORTE/LAMBERT
LONG TERM...LAMBERT/GARTNER
AVIATION...STEINBUGL

AREA FORECAST DISCUSSION...UPDATED

NWS SAN ANGELO TX

1151 PM CST MON FEB 11 2013

.DISCUSSION...
SEE AVIATION SECTION.

.AVIATION...
ELEVATED CONVECTION IS DEVELOPING/INCREASING IN COVERAGE ACROSS
WEST CENTRAL TEXAS. LATEST RADAR TRENDS AND SHORT-RANGE MODEL
DATA INDICATE THAT THE GREATEST COVERAGE WILL BE ACROSS THE BIG
COUNTRY AND NORTHERN CONCHO VALLEY DURING THE OVERNIGHT HOURS.
CARRYING A TSRA GROUP AT KABI...WITH A VCSH MENTION AT KSJT AND
KBBD. BRIEF HEAVY RAIN IS POSSIBLE...AND A FEW OF THE STRONGEST
STORMS MAY CONTAIN SMALL HAIL. WITH ONGOING LOW-LEVEL MOIST
ADVECTION...CLOUD CEILINGS WILL CONTINUE TO DECREASE OVERNIGHT.
HAVE TRENDED CLOSER TO MODEL GUIDANCE WITH THE 06Z TAF PACKAGE.
IFR CEILINGS ARE EXPECTED OVERNIGHT AT ALL SITES EXCEPT KSJT...
WHERE CEILING SHOULD STAY ABOVE 1K FT. WINDS WILL BE EAST-
SOUTHEAST AT 9-12 KT THROUGH EARLY TUESDAY MORNING. A DRY AIR
SURGE FROM THE WEST WILL OVERSPREAD WEST CENTRAL TEXAS TUESDAY
MORNING. WITH THE ONSET OF WEST WINDS...SKIES WILL CLEAR OUT
QUICKLY WITH VFR CONDITIONS EXPECTED THROUGH THE REST OF THE DAY.
GUSTY WEST WINDS WILL OCCUR DURING THE LATE MORNING AND AFTERNOON
HOURS AT ALL TAF SITES EXCEPT KABI...WHERE A COLD FRONT WILL
ARRIVE BY 21Z. THE COLD FRONT WILL PUSH SOUTH ACROSS WEST CENTRAL
TEXAS DURING THE AFTERNOON AND EVENING HOURS. GUSTY WEST WINDS
WILL SHIFT TO NORTH- NORTHWEST WITH PASSAGE OF THIS FRONT. WIND
SPEEDS WILL DECREASE DURING THE FINAL HOURS OF THE TAF PERIOD.

.PREV DISCUSSION... /ISSUED 1106 PM CST MON FEB 11 2013/

UPDATE...

NEW MODEL DATA HAS ARRIVED...AND NUMEROUS THUNDERSTORMS ACROSS THE
BIG COUNTY FOR THE REMAINDER OF TONIGHT DOES NOT LOOK AS
PROMISING. THE LATEST MESOSCALE DATA FROM THE STORM PREDICTION
CENTER DO INDICATE MID-LEVEL CAPES HAVE INCREASE ACROSS AT LEAST
SOME OF OUR WESTERN COUNTIES DURING THE LAST COUPLE HOURS.
THUS...I STILL EXPECT THUNDERSTORM TONIGHT. THE LATEST RUC AND
NAM MODEL DATA CONTINUE TO INDICATE THE BEST POTENTIAL FOR SHOWERS
AND THUNDERSTORMS WILL BE ACROSS MAINLY OUR BIG COUNTRY COUNTIES
TONIGHT. SO...I DID MAINTAIN THE HIGHEST POPS THERE FOR THE
REMAINDER OF TONIGHT. HOWEVER...I DID REDUCE THUNDERSTORM COVERAGE
FROM NUMEROUS TO SCATTERED. ELSEWHERE TONIGHT...ISOLATED
THUNDERSTORMS LOOK REASONABLE. ALSO...THE LATEST SATELLITE DATA
INDICATE LOW CLOUDS AND HIGHER CLOUDS ARE COMBINING TO PRODUCE
CLOUDY SKIES ACROSS ALL OF WEST CENTRAL TEXAS AT THIS TIME. SO...I
ALSO ADJUSTED SKY CONDITIONS TO REFLECT CLOUDY SKIES FOR THE
REMAINDER OF TONIGHT. ALL ELSE FOR THE REMAINDER OF TONIGHT LOOKS
GOOD. RECENT ZONE AND OTHER PRODUCTS REFLECT THESE CHANGES.

HUBER

PREV DISCUSSION... /ISSUED 603 PM CST MON FEB 11 2013/

DISCUSSION...
SEE AVIATION SECTION.

AVIATION...
A DEGRADATION OF CONDITIONS IS EXPECTED TONIGHT ACROSS WEST CENTRAL
TEXAS...AS LOW-LEVEL MOISTURE INCREASES SUBSTANTIALLY AND CLOUD
CEILINGS DECREASE. WITH SOME UNCERTAINTY ON HOW LOW THE CEILINGS
AND VISIBILITIES WILL BE...TAKING A CONSERVATIVE APPROACH AT THIS TIME.
CURRENTLY THIS EVENING...CLOUD CEILINGS ARE ABOVE 3K FT AT ALL TAF
SITES EXCEPT KJCT. EXPECT CEILINGS TO LOWER INTO THE MVFR CATEGORY
BY 06Z AT KABI AND KSJT...AND BETWEEN 00Z AND 06Z AT KBBD AND KSOA.
ELEVATED CONVECTION IS EXPECTED TO DEVELOP BETWEEN 03Z AND 06Z...AND
THEN TO CONTINUE OVERNIGHT. THE GREATER COVERAGE WILL LIKELY BE OVER
THE BIG COUNTRY. CARRYING A -TSRA MENTION AT KABI...AND HAVE INSERTED
VCSH AT KSJT. GOING WITH IFR CONDITIONS LATE TONIGHT AT KABI...WITH
LOW END MVFR CONDITIONS AT KBBD AND KJCT. CARRYING CEILINS IN THE
1500-2000 FT RANGE AT KSOA AND KSJT. A DRY PUNCH FROM THE WEST WILL
OVERSPREAD WEST CENTRAL TEXAS ON TUESDAY MORNING. WITH THE ONSET
OF WEST WINDS...SKIES WILL CLEAR QUICKLY WITH VFR CONDITIONS EXPECTED
THROUGH THE REST OF THE DAY. GUSTY WEST WINDS ARE EXPECTED DURING
THE LATE MORNING AND AFTERNOON HOURS. A COLD FRONT WILL PUSH SOUTH
ACROSS ROUGHLY THE NORTHERN HALF OF WEST CENTRAL TEXAS DURING THE
AFTERNOON...REACHING KABI AROUND 21Z. WINDS WILL SHIFT TO THE
NORTH WITH PASSAGE OF THIS FRONT.

PREV DISCUSSION... /ISSUED 342 PM CST MON FEB 11 2013/

SHORT TERM...
STILL SHOWING SOME LIGHT SHOWERS OVER OUR SOUTHEASTERN COUNTIES
EARLY THIS AFTERNOON ASSOCIATED WITH ON-GOING WEAK ISENTROPIC ASCENT
OVER A FRONTAL BOUNDARY LOCATED SOUTH OF THE FORECAST AREA. THIS
ACTIVITY SHOULD CONTINUE TO WEAKEN THROUGH THE REMAINDER OF THE
AFTERNOON...WILL HOWEVER KEEP SHOWERS AND ISOLATED THUNDERSTORMS
OVER OUR SOUTHEASTERN COUNTIES PRE FIRST PERIOD. AN UPPER LEVEL LOW
OVER THE FOUR CORNERS AREA THIS EVENING WILL MOVE EAST OVER THE RED
RIVER VALLEY BY LATE TOMORROW AFTERNOON... PUSHING A PACIFIC
FRONT/DRYLINE THROUGH THE FORECAST AREA TUESDAY MORNING. IN ADVANCE
OF THIS UPPER LEVEL SYSTEM... MOISTURE ADVECTING NORTH OVER THE
FORECAST AREA TONIGHT WILL SATURATE THE SURFACE TO 850MB LAYER OVER
MOST OF THE CWA AS A LLJ STRENGTHENS OVER THE NORTHERN FORECAST AREA
AFTER MIDNIGHT. LATEST FORECAST SOUNDINGS ARE SHOWING THE BEST
CHANCE OF CONVECTION OVER THE NORTHERN CWA AFTER MIDNIGHT AS UPPER
LEVEL SHEAR AND INSTABILITY INCREASES. THE LATEST 3KM WRF MODEL IS
ALSO HIGHLIGHTING THE BIG COUNTRY AS HAVING THE BEST OPPORTUNITY FOR
RAINFALL. WILL THEREFORE LEAVE THE HIGHER POPS OVER THE NORTHERN CWA
THROUGH THE NIGHT WITH RAINFALL ENDING FROM THE SOUTHWEST TO THE
NORTHEAST FROM DAYBREAK TO AROUND NOON.

WITH CLOUDY SKIES OVERNIGHT...WILL SEE TUESDAY MORNING LOWS
GENERALLY IN THE MID 40S...WARMING INTO THE 50S OVER THE BIG COUNTRY
AND INTO THE 60S OVER THE REMAINDER OF THE FORECAST AREA. SKIES WILL
BE CLEARING FROM THE WEST THROUGH THE DAY ON TUESDAY.

LONG TERM...
VERY FEW CHANGES TO THE EXTENDED FORECAST FOR THE REST OF THE WEEK
AND INTO THE WEEKEND. WITH THE PASSAGE OF THE UPPER LEVEL STORM
SYSTEM TOMORROW...DRY NORTHWEST FLOW ALOFT PREVAILS INTO THE
WEEKEND. WILL CONTINUE TO MONITOR THE PATH OF THE NEXT UPPER LEVEL
TROUGH FOR FRODAY AND SATURDAY...BUT BOTH THE GFS AND THE ECMWF HAVE
CONTINUED THE TREND OF A WEAKER PROGRESSIVE SHORTWAVE PASSING
ACROSS THE AREA...INSTEAD OF THE CLOSED OFF SYSTEM THEY WERE
SHOWING SEVERAL DAYS AGO. WITH THIS WEAKER MORE PROGRESSIVE
SYSTEM...WILL KEEP THE FORECAST DRY FOR NOW.

MODELS HAVE SOME DIFFERENCES WITH THE TIMING OF A COLD FRONT ON
FRIDAY. WILL STICK TO THE ECMWF FOR NOW...SHOWING A LITTLE FASTER
FRONT AND A LITTLE COOLER TEMPERATURES FOR FRIDAY.

.PRELIMINARY POINT TEMPS/POPS...
ABILENE 44 56 33 59 35 / 70 30 5 0 0
SAN ANGELO 45 62 35 62 32 / 40 20 0 0 0
JUNCTION 47 64 33 63 30 / 40 20 5 0 0

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION...UPDATED

NWS AMARILLO TX

1132 PM CST MON FEB 11 2013

.AVIATION...
FOR THE 06Z TAFS...A VERY FAST EVOLVING SYSTEM HAS LED TO SOME
CHANGES FROM THE 00Z TAF ISSUANCE. THE BIGGEST CHANGE IS THE FASTER
ONSET OF SN. ALREADY SN IS REPORTED IN WESTERN PANHANDLES AND SHOULD
BEGIN IN KDHT AND KAMA WITHIN THE NEXT HOUR...AND KGUY WITHIN THE
NEXT 2 HOURS. EXPECT INTERMITTENT SHSN THROUGH 09Z...BEFORE IT
TRANSITIONS TO A MORE WIDESPREAD EVENT. ANOTHER CHANGE IS THE
OBSERVATION OF TSSN IN THE SOUTHERN TX PANHANDLE...INCLUDING N OF
KAMA. AT THIS POINT WILL NOT INCLUDE ANY TSSN IN THE TAFS AS THE
INITIAL THREAT IS N OF KAMA AND VERY UNLIKELY TO GET AS FAR N AS KDHT.
THE RAP INDICATES SOME INSTABILITY BETWEEN 09 AND 12Z...AND THUS SOME
THREAT AGAIN FOR TSSN BUT THE LIKELIHOOD OF IT REDEVELOPING IS
LOW...AND WOULD BE ISOLATED AT BEST...SO WILL NOT INCLUDE IN THE
TAFS. STILL THINK THE HEAVIEST SN...AND THUS LOWEST VISIBILITIES WILL
BE AT KAMA...WHERE 1/2SM IS LIKELY...AND BRIEF PERIODS OF 1/4SM ARE
POSSIBLE. OUTSIDE OF THE HEAVIEST BANDS OF SN...EXPECT VISIBILITIES
MAINLY BETWEEN 1 AND 3SM FOR THE MAJORITY OF THIS EVENT. THIS IS
MORE PESSIMISTIC THAN THE GFS LAMP...BUT GIVEN UPSTREAM OBS...THINK
THE LOWER VISIBILITIES ARE LIKELY. MODELS ARE ALSO TRENDING FASTER NOW WITH
THE SN LEAVING THE AREA...THINK THAT THE MAJORITY OF THE SN WILL BE
BEFORE 18Z. ONCE THE SN LEAVES...MAY BE A PERIOD OF MVFR
CEILINGS...BEFORE CONDITIONS RETURN TO VFR.

JOHNSON
&&

.PREV DISCUSSION... /ISSUED 954 PM CST MON FEB 11 2013/

UPDATE...

HAVE MADE A FEW CHANGES TO GOING FORECAST AS RECENT MODEL TRENDS HAVE
TRENDED EARLIER...COLDER...AND A BIT HEAVIER WITH THE IMPENDING SNOW.
SNOW HAS ALREADY SPREAD INTO THE WESTERN TEXAS PANHANDLE...WITH
TEXLINE REPORTING MODERATE SNOW.

TIMING...
HAVE SHIFTED ALMOST ALL AREAS FORWARD ABOUT 3 HOURS FOR THE ONSET OF
SNOW GIVEN RECENT HRRR AND NAM RUNS. THIS BRINGS TOTALS UP TO 1-3
INCHES SW OF A CANADIAN TO GUYMON LINE BEFORE THE MORNING COMMUTE.
THE I40 CORRIDOR EAST OF AMARILLO WILL LIKELY SEE THE HEAVIEST SNOWS
BEFORE 12Z AND THROUGHOUT THE EVENT. HAVE ALSO BROUGHT THE SNOW TO
AN END QUICKER...WITH ALL SNOWS LIKELY EAST OF THE PANHANDLES BY 00Z.

AMOUNTS...
THE MAIN CHANGE WAS TO INCREASE AMOUNTS IN AN AREA BOUNDED
BY ROUGHLY I27 ON THE WEST AND I40 ON THE NORTH. IT PREVIOUSLY
APPEARED THAT THE DAYTIME TIMING AND SUBSEQUENT LOWER SNOW TO LIQUID
RATIOS WOULD KEEP TOTALS DOWN A BIT IN THESE AREAS. HOWEVER...THE
BULK OF THE SNOW NOW LOOKS TO FALL BETWEEN 09Z-15Z...MEANING THAT
RATIOS WILL LIKELY BE HIGHER AND AMOUNTS GREATER. GIVEN SOME LIKELY
MODEL UNDERESTIMATION OF DYNAMIC COOLING IN THESE AREAS...FELT A
BUMP UP IN TOTALS PRUDENT. CURRENT THINKING IS THAT THE AMARILLO AREA
COULD SEE 4-7 INCHES...WITH HIGHER AMOUNTS FURTHER EAST. GIVEN RECENT
MODEL TRENDS...AM A BIT CONCERNED WE COULD END UP SEEING AN ISOLATED
BIG NUMBER IN THE DOUBLE DIGITS SOMEWHERE IN THE ROBERTS/GRAY/
HEMPHILL/WHEELER COUNTY AREA.

UPDATED GRIDS/ZONES WILL BE OUT VERY SOON.

SIMPSON

PREV DISCUSSION... /ISSUED 543 PM CST MON FEB 11 2013/

AVIATION...
FOR THE 00Z KAMA TAF...VFR CONDITIONS ARE EXPECTED THROUGH 06Z...THEN
A WINTER STORM LEADS TO A MORE COMPLICATED AND LOWER CONFIDENCE
FORECAST AFTER 06Z THROUGH THE END OF THE TAF PERIOD. HIGH CONFIDENCE
THAT THE TERMINAL WILL SEE SN...PRIMARILY BETWEEN 09 AND 18Z...AND
IFR OR LOWER CONDITIONS THROUGH THIS TIME. THOUGH WINDS WILL BE
BREEZY BETWEEN 12 AND 18Z...DO NOT EXPECT TOO MUCH BLSN DUE TO THE
SNOW TO LIQUID RATIO BEING A BIT LOW. SN WILL SLOWLY TAPER OFF
AFTER 18Z...AND SHOULD BE OUT OF THE AREA BY 21Z. CONDITIONS SHOULD
IMPROVE TO VFR ONCE THE SN ENDS.

FOR THE 00Z KDHT AND KGUY TAFS...VFR CONDITIONS ARE LIKELY THROUGH
06Z...WITH THE ONLY POSSIBLE EXCEPTION OF LIGHT SN STARTING IN KDHT
POSSIBLY AS EARLY AS 03Z. AFTER 06Z...THERE IS LOWER CONFIDENCE GIVEN
THE INCOMING WINTER STORM. AT THIS POINT...EXPECT SN TO START IN KDHT
LIKELY AROUND 06Z...AND KGUY BETWEEN 09 AND 12Z. FOR THE MOST PART
THROUGH THIS EVENT...EXPECT LOW MVFR OR IFR CONDITIONS. SN AT THESE 2
TERMINALS IS NOT EXPECTED TO BE AS DEEP OR HEAVY AS KAMA. SN SHOULD
BEGIN TO TAPER OFF NEAR 18Z...AND SHOULD BE OUT OF THE AREA BY 21Z.
ONCE THE SN ENDS...EXPECT VFR CONDITIONS THROUGH THE REMAINDER OF THE
TAF PERIOD.

JOHNSON

PREV DISCUSSION... /ISSUED 400 PM CST MON FEB 11 2013/

DISCUSSION...
THROUGH TONIGHT: UPPER TROUGH MOVING ACROSS THE FOUR CORNERS WILL
DEEPEN AS IT APPROACHES THE PANHANDLES TONIGHT. AHEAD OF THIS UPPER
TROUGH, EASTERLY UPSLOPE WINDS AND ISENTROPIC LIFT WILL INCREASE
MOISTURE SUBSTANTIALLY AS THE NIGHT PROGRESSES. THE COMBINATION OF
THE LOW- AND UPPER-LEVEL LIFT AND MOISTURE SHOULD TRIGGER THE
DEVELOPMENT OF PRECIPITATION ACROSS NORTHEAST NEW MEXICO LATER THIS
EVENING AND THEN SPREAD INTO THE NORTHWEST PANHANDLES AFTER 9 PM. AS
TEMPERATURES COOL, THIS PRECIPITATION IS EXPECTED TO FALL AS SNOW,
ROUGHLY WEST OF A GUYMON TO BOOTLEG LINE THROUGH MIDNIGHT. SOME LIGHT
ACCUMULATIONS OF AROUND ONE HALF OF AN INCH WILL BE POSSIBLE ACROSS
THE WESTERN PORTIONS OF CIMARRON AND DALLAM COUNTIES. AFTER MIDNIGHT,
CHANCES FOR PRECIPITATION WILL INCREASE AND CONTINUE ACROSS THE
NORTHWEST. A SECOND, MORE CONCENTRATED, SWATCH OF PRECIPITATION IS
EXPECTED TO SPREAD NORTHWARD INTO THE SOUTHEASTERN TEXAS PANHANDLE
AFTER 3 AM. FORECAST SOUNDINGS AFTER 3 AM WILL BE SUPPORTIVE OF WET
SNOW ACROSS MOST OF THESE AREAS. HOWEVER, FOR LOCATIONS SOUTH AND
EAST OF A LINE FROM CLARENDON TO SHAMROCK, WET BULB ZERO HEIGHTS WILL
REMAIN ABOVE 2,000 FEET...WHICH WILL KEEP THE PRECIPITATION TYPE AS
RAIN. AS THE COLUMN COOLS TOWARDS SUNRISE, THE RAIN IS EXPECTED TO
TRANSITION TO SNOW IN THESE LOCATIONS. IN BETWEEN THESE TWO AREAS,
INCLUDING AMARILLO, BORGER, AND PERRYTON, THERE MAY NOT BE MUCH IN
THE WAY OF PRECIPITATION OVERNIGHT. HOWEVER, WE KEPT A MENTION OF
SNOW IN THE FORECAST, BUT AMOUNTS IN THESE LOCATIONS WILL BE A
DUSTING TO ONE HALF OF AN INCH AT MOST.

TUESDAY-TUESDAY NIGHT: THE BEST COMBINATION OF DYNAMICS AND MOISTURE
WILL OCCUR DURING THE DAY ON TUESDAY. AS THIS OCCURS, SNOW IS
EXPECTED TO DEVELOP ACROSS ALL OF THE PANHANDLES WITH THE HIGHEST
CHANCES BEING SOUTHEAST OF A GUYMON TO HEREFORD LINE. DUE TO STRONG
DYNAMICS IN PLACE, SOME OF THE SNOW COULD BE HEAVY AT TIMES. THE
TIME FRAME FOR THE HEAVIEST SNOW LOOKS TO BE BETWEEN 8 AM AND 3 PM.
MOISTURE WILL BE LOWEST ACROSS THE NORTHERN AND WESTERN PORTIONS OF
THE PANHANDLES. AS A RESULT, THESE LOCATIONS WILL LIKELY SEE THE
LIGHTEST SNOWFALL ACCUMULATIONS, BUT TOTAL SNOWFALL AMOUNTS WILL
STILL BE BETWEEN 2 AND 5 INCHES WITH LOCALLY HIGHER AMOUNTS UP TO 6
INCHES. DEEPER MOISTURE WILL BE CONFINED TO THE SOUTHEAST THIRD OF
THE PANHANDLES WHERE TOTAL SNOWFALL ACCUMULATIONS WILL BE BETWEEN 6
AND 9 INCHES WITH LOCALLY HIGHER AMOUNTS POSSIBLE. THE HEAVIEST
SNOWFALL TOTALS ARE EXPECTED TO OCCUR IN AN AREA EAST OF A LINE FROM
CANADIAN TO PAMPA TO CLAUDE AND GENERALLY NORTH OF INTERSTATE 40.
IT`S NOT OUT OF THE QUESTION SOME LOCATION IN THIS AREA COULD
RECEIVE AS MUCH AS 10 INCHES OF SNOW. WE DO HAVE SOME CONCERN THAT
MODELS HAVE BEGUN TRENDING SLIGHTLY FARTHER NORTH WITH THE UPPER
TROUGH. THIS COULD SIGNIFICANTLY REDUCE THE SNOW AMOUNTS IN THE
SOUTHERN PART OF THE TEXAS PANHANDLE AND SHIFT THE HIGHER TOTALS
FARTHER NORTH. WE`LL NEED TO WATCH THIS CLOSELY IN CASE THE WINTER
STORM WARNING NEEDS TO BE ADJUSTED. WE HAVE HIGH CONFIDENCE THAT
EVERY LOCATION WILL SEE AT LEAST SOME SNOW OVER THE NEXT 24 HOURS,
AND THIS IS SUPPORTED BY THE CIPS ANALOG GUIDANCE.

THE SNOW IS EXPECTED TO BEGIN TAPERING OFF FROM NORTHWEST TO
SOUTHEAST BY LATE TUESDAY AFTERNOON. THERE IS A POSSIBILITY THAT
TEMPERATURES WILL RISE ABOVE FREEZING DURING THE AFTERNOON ACROSS
MOST OF THE AREA, ESPECIALLY ACROSS THE NORTHWEST HALF OF THE
PANHANDLES AND THE FAR SOUTHEASTERN TEXAS PANHANDLE. THIS WILL
LIKELY HELP LIMIT/SIGNIFICANTLY CUT DOWN ON ADDITIONAL SNOWFALL
ACCUMULATIONS. TUESDAY EVENING, SNOW IS EXPECTED TO CONTINUE EAST OF
A BEAVER TO CLAUDE LINE THROUGH TUESDAY EVENING BEFORE ENDING BY
MIDNIGHT. LOW TEMPERATURES IN THE TEENS TO LOWER 20S WILL BE LIKELY
DUE TO LIGHT WINDS, CLEAR SKIES, AND SNOW COVER.

JACKSON

WEDNESDAY-MONDAY: AN UPPER TROUGH WILL MOVE EAST OF THE PANHANDLES
WEDNESDAY WITH A DRY NORTHWESTERLY UPPER FLOW ACROSS THE PANHANDLES
WEDNESDAY AND THURSDAY. A NORTHERN STREAM SHORTWAVE TROUGH WILL DROP
SOUTHEAST OUT OF THE ROCKIES BY LATE THURSDAY AND ALLOW FOR A STRONG
COLD FRONT TO PUSH THROUGH THE FORECAST AREA WEDNESDAY NIGHT AND
THURSDAY MORNING. SCATTERED RAIN OR SNOW SHOWERS ARE EXPECTED TO PUSH
SOUTH AND EAST ACROSS THE NORTHERN SECTIONS OF THE PANHANDLES
THURSDAY NIGHT...AND THEN ACROSS MUCH OF THE PANHANDLES FRIDAY. SNOW
COVER WEDNESDAY AND POSSIBLY EVEN INTO THURSDAY WILL HOLD
TEMPERATURES DOWN...SO UNDERCUT MOS GUIDANCE. COLDER FRIDAY AND
TEMPERATURES SATURDAY WILL DEPEND ON ANY SNOW COVER FROM THE THURSDAY
NIGHT AND FRIDAY SYSTEM. OTHERWISE...MODERATING CONDITIONS LATE THIS
WEEK AND INTO THE WEEKEND AS HIGH PRESSURE PREVAILS WITH A DRY
NORTHWESTERLY FLOW ALOFT.

SCHNEIDER

FIRE WEATHER...
AN UPPER TROUGH WILL APPROACH THE TEXAS AND OKLAHOMA PANHANDLES
TONIGHT AND TUESDAY BRINGING INCREASING CHANCES FOR SNOW. ALTHOUGH
THE SNOW IS EXPECTED TO END BY TUESDAY EVENING AS THE UPPER TROUGH
MOVES OFF TO THE EAST OF THE PANHANDLES...THE SNOW COVER WILL LINGER
THROUGH WEDNESDAY. THEREFORE...NO ELEVATED OR CRITICAL FIRE WEATHER
CONDITIONS ARE EXPECTED THROUGH WEDNESDAY.

SCHNEIDER

.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY UNTIL 6 PM CST TUESDAY FOR THE FOLLOWING
ZONES: DALLAM...DEAF SMITH...HANSFORD...HARTLEY...MOORE...
OCHILTREE...OLDHAM...SHERMAN.

WINTER STORM WARNING FROM 3 AM TO 6 PM CST TUESDAY FOR THE
FOLLOWING ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...
DONLEY...GRAY...HEMPHILL...HUTCHINSON...LIPSCOMB...POTTER...
RANDALL...ROBERTS...WHEELER.

OK...WINTER WEATHER ADVISORY UNTIL 6 PM CST TUESDAY FOR THE FOLLOWING
ZONES: BEAVER...CIMARRON...TEXAS.

16/09

AREA FORECAST DISCUSSION

NWS SAN ANGELO TX

1106 PM CST MON FEB 11 2013

.UPDATE...

HUBER

.PREV DISCUSSION... /ISSUED 603 PM CST MON FEB 11 2013/

DISCUSSION...
SEE AVIATION SECTION.

PREV DISCUSSION... /ISSUED 342 PM CST MON FEB 11 2013/

MODELS HAVE SOME DIFFERENCES WITH THE TIMING OF A COLD FRONT ON
FRIDAY. WILL STICK TO THE ECMWF FOR NOW...SHOWING A LITTLE FASTER
FRONT AND A LITTLE COOLER TEMPERATURES FOR FRIDAY.

.PRELIMINARY POINT TEMPS/POPS...
ABILENE 44 56 33 59 35 / 70 30 5 0 0
SAN ANGELO 45 62 35 62 32 / 40 20 0 0 0
JUNCTION 47 64 33 63 30 / 40 20 5 0 0

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

HUBER

AREA FORECAST DISCUSSION

NWS LA CROSSE WI

827 PM CST WED FEB 13 2013

.SHORT TERM...TONIGHT INTO THURSDAY
827 PM CST WED FEB 13 2013

827 PM BRIEF UPDATE...14.00Z NAM SHIFTED THE NARROW FRONTOGENESIS
BAND ON THE NORTH SIDE OF THE SURFACE LOW SLIGHTLY SOUTH...
IMPACTING MOSTLY CLARK NOW. 14.23Z HRRR ALSO HAS A VERY SLIGHT
TREND SOUTH. GIVEN THE UNCERTAINTY ON WHERE EXACTLY THIS BAND WILL
SET UP...HAVE DECLINED TO UPGRADE TO A WARNING. IN GENERAL...SNOW
AMOUNTS SHOULD TOTAL IN THE 3-6 INCH RANGE...HIGHEST MOST LIKELY
OCCURRING IN NORTHERN CLARK COUNTY. DEFINITELY HEAVIEST SNOW
BETWEEN MIDNIGHT AND 8 AM REMAINS ON TARGET.

724 PM BRIEF UPDATE...IN ADDITION TO THE UPDATE INFORMATION BELOW
MADE AT 555 PM...NOTICED THAT BLENDING THE QPF FOR 06-12Z THURSDAY
FROM THE PREFERRED MODEL GROUP RESULTS IN A NARROW BAND AROUND
HIGHWAY 29 INTO SOUTHERN TAYLOR COUNTY UPWARDS OF 0.30 INCHES.
SNOW TO WATER RATIOS...GIVEN ONLY A 75 MB DEEP DENDRITIC GROWTH
ZONE PROGGED...SHOULD END UP MOSTLY IN THAT 13-15 TO 1 RANGE...
RESULTING IN A 6 HOUR PERIOD OF 3-5 INCHES OF SNOW. WE COULD
APPROACH LOW END WARNING CRITERIA IN THIS BAND. AFTER
COLLABORATION WITH GRB...WILL STICK WITH THE ADVISORY FOR NOW
PENDING THE 14.00Z NAM. TOUGHEST PART WITH A WARNING WOULD BE
GRABBING THE RIGHT AREA SINCE THIS WILL BE A NARROW BAND.

MAIN UPDATE AT 555 PM...

TWO SHORTWAVES ARE EVIDENT ON WATER VAPOR...ONE OVER WEST CENTRAL
MINNESOTA AND THE OTHER IN SOUTHERN SASKATCHEWAN. THESE ARE BOTH
DROPPING SOUTHEAST THROUGH THE NORTHWEST FLOW ALOFT. WITH THE WEST
CENTRAL MINNESOTA SHORTWAVE...TWO AREAS OF RADAR RETURNS ARE
PRESENT. THE FIRST ASSOCIATED WITH WARM ADVECTION EXTENDS FROM
JUST WEST OF THE TWIN CITIES SOUTH INTO NORTH CENTRAL IOWA. SO
FAR...OBSERVATIONS HAVE NOT SHOWN MUCH PRECIPITATION FALLING FROM
THIS BAND...SUGGESTING A LOW LEVEL DRY AIR ISSUE ABSORBING THE
PRECIPITATION. THE SECOND BAND ON THE OTHER HAND IS PRODUCING
SNOW...WHICH STRETCHED FROM JAMESTOWN NORTH DAKOTA TO ST CLOUD MN.
THIS BAND IS ASSOCIATED WITH LOW TO MID-LEVEL FRONTOGENESIS ON THE
NORTH SIDE OF THE SHORTWAVE TRACK. MANY VISIBILITY REPORTS OF A
1/2 MILE TOO IN THE SNOW.

13.20Z HRRR...13.18Z NAM...13.12Z HIRES-NMM AND REGIONAL CANADIAN
ALL HAVE BEEN HANDLING CURRENT RADAR TRENDS WELL WITH THE WEST
CENTRAL MINNESOTA SHORTWAVE. THE IDEA IS THAT THE WARM ADVECTION
BAND OF RADAR RETURNS WILL MOVE ACROSS THE SOUTHERN TWO-THIRDS OF
THE FORECAST AREA BETWEEN 02-08Z...LASTING FOR A COUPLE OF HOURS
AT ANY ONE LOCATION...FOLLOWED BY A DRY SLOT. GIVEN LACK OF
PRECIPITATION OBSERVED UPSTREAM...AM UNCERTAIN WHETHER WE WILL SEE
ANY PRECIPITATION FROM THIS BAND. HAVE TRENDED PRECIPITATION
CHANCES TOWARDS THE ABOVE MODEL GROUP IDEA AND MAY HAVE TO DRY
THINGS OUT MORE. IF PRECIPITATION OCCURS...IT NOW LOOKS MORE LIKE
A RAIN/SNOW ISSUE GIVEN THE WARM LAYER IS AT THE SURFACE. MODELS
HAD SUGGESTED A WARM LAYER RIGHT ABOVE THE SURFACE...BUT THIS
SEEMS OVERDONE BECAUSE THEY ARE NOT HANDLING THE TEMPERATURES WELL
ACROSS THE SLOWLY DIMINISHING SNOWPACK. AS SUCH...REMOVED THE
FREEZING RAIN/SLEET POTENTIAL. THE NORTHERN BAND IS STILL ON TRACK
TO IMPACT THE ADVISORY AREA AFTER 03Z. WOULD NOT BE SURPRISED TO
SEE VISIBILITIES QUICKLY DROP TO 1 MILE OR LESS SEEING THE 1/2
MILE UPSTREAM. THE NORTHERN BAND IS THEN SUGGESTED TO WRAP
BACKWARDS AND TRACK SOUTHEAST ACROSS MUCH OF THE FORECAST AREA
BETWEEN 09-16Z...WELL TRENDED FROM THE PREVIOUS FORECAST. AM
CONCERNED A LITTLE BIT ABOUT HOW MUCH QPF COULD OCCUR IN TAYLOR
AND CLARK COUNTIES WHERE THE ADVISORY IS POSTED. THE 13.12Z
HIRES-NMM IS ABOUT 0.10 OF AN INCH HIGHER THAN CURRENTLY FORECAST
FOR 06-12Z TONIGHT...WITH THE HRRR SUGGESTING SIMILAR POTENTIAL.
HAVE RAISED QPF SLIGHTLY BUT MAY NEED TO RAISE MORE. SNOWFALL
AMOUNTS UP TO 5 INCHES NOW SEEM POSSIBLE...STILL BELOW WARNING
CRITERIA AT THIS POINT.

FOR THURSDAY...THERE LOOKS TO BE A BREAK BETWEEN THE CURRENT
SHORTWAVE TRACKING THROUGH TONIGHT INTO TOMORROW MORNING AND THEN
THE ONE APPROACHING FROM SOUTHERN SASKATCHEWAN. HIRES MODELS /ARW
AND NMM/ TRACK THE SHORTWAVE INTO IOWA...WITH ITS LOW TO MID LEVEL
FRONTOGENESIS BAND IMPACTING FAR WESTERN PORTIONS OF SOUTHEAST
MINNESOTA AND INTO NORTHEAST IOWA...PRIMARILY BETWEEN 21-03Z. MAY
MAKE SOME ADJUSTMENTS TO PRECIPITATION CHANCES TO ACCOUNT FOR THE
TRACK OF THIS FRONTOGENESIS BAND.

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
236 PM CST WED FEB 13 2013

13.12 MEDIUM RANGE MODELS ARE IN REASONABLE AGREEMENT SATURDAY NIGHT
THROUGH MONDAY. UPPER LEVEL RIDGE WILL MOVE OVER THE REGION ON
SUNDAY. SOUTHERLY FLOW AT THE SURFACE WILL INCREASE AHEAD OF A
TROUGH RACING ACROSS THE NORTHERN ROCKIES. WILL HAVE TO KEEP A CLOSE
EYE ON TEMPERATURES ON SUNDAY. THE LATEST ECMWF WARMS HIGHS INTO
THE UPPER 30S TO LOWER 40S SOUTH OF INTERSTATE 90 AND THIS SEEMS
REASONABLE. THE NEXT TROUGH IS EXPECTED TO MOVE ACROSS THE REGION ON
MONDAY BUT THE FORECAST AREA LOOKS TO BE SPLIT BETWEEN A SOUTHERN
STREAM WAVE MOVING UP THE OHIO RIVER VALLEY AND A NORTHERN STREAM
WAVE MOVING ACROSS SOUTHERN ONTARIO/NORTHERN LAKE SUPERIOR. A COLD
FRONT WILL MOVE ACROSS THE AREA MONDAY NIGHT INTO TUESDAY WITH
COOLER AIR ARRIVING ON TUESDAY. HIGHS ARE EXPECTED TO FALL INTO THE
TEENS TO LOWER 20S. COOL HIGH PRESSURE WILL REMAIN OVERHEAD INTO
WEDNESDAY WITH MAINLY DRY AND QUIET WEATHER EXPECTED.

.AVIATION...TONIGHT AND THURSDAY
604 PM CST WED FEB 13 2013

VFR CONDITIONS BEGIN THIS TAF PERIOD DUE TO THE PRESENCE OF LOW
LEVEL DRY AIR IN THE TROPOSPHERE. TO THE WEST...A BAND OF
ALTOSTRATUS WAS TRACKING ACROSS SOUTH CENTRAL MINNESOTA AND NORTH
CENTRAL IOWA...ASSOCIATED WITH A WARM FRONT EXTENDING FROM A LOW
JUST EAST OF ABERDEEN SOUTH DAKOTA. SO FAR CEILINGS ARE MAINLY VFR
WITH SOME POCKETS OF MVFR DEVELOPING ON ITS NORTHERN END. THERE
ARE A FEW RAIN/SNOW REPORTS AS WELL. EXPECTING THIS BAND TO MOVE
THROUGH THE TAF SITES BETWEEN 03-06Z. IF THE LIFT CAN OVERCOME
SOME OF THE DRY AIR IN THE LOWER LEVELS...COULD SEE A BRIEF PERIOD
OF MVFR CEILINGS AND VISIBILITIES FROM SNOW. OTHERWISE...VFR
CONDITIONS ARE EXPECTED AS THE BAND PASSES. IN ITS WAKE...LOW
STRATUS OVER WEST CENTRAL MINNESOTA WITH CEILINGS IN THE MVFR AND
IFR RANGE WILL GRADUALLY MAKE THEIR WAY SOUTHEAST INTO THE TAF
SITES. THE LOWEST CEILINGS WILL COME IN THE 10-17Z TIME PERIOD
WHEN A COLD FRONT AND A BAND OF SNOW BEHIND THIS FRONT MOVE
THROUGH. IN FACT...THE SNOW SHOULD KNOCK VISIBILITIES DOWN TO
IFR...ESPECIALLY AT KLSE. ACCUMULATIONS LOOK LIGHT...THOUGH...LESS
THAN AN INCH. BY 18Z...ANTICIPATING CEILINGS AND VISIBILITIES TO
CLIMB BACK UP TO AT LEAST MVFR...AND PERHAPS HIGHER...AS THIS LOW
PRESSURE SYSTEM MOVES EAST OUT OF THE REGION.

ANOTHER LOW PRESSURE SYSTEM WILL QUICKLY COME IN ON THE TAILS OF
THE CURRENT ONE...TRACKING FARTHER SOUTH...THOUGH. ITS SNOW MAY
CLIP THE TAF SITES...MORE LIKELY AT KRST LATE IN THE AFTERNOON.
THUS...FOR SIMPLICITY HELD KRST AT MVFR VISIBILITIES FOR THE
ENTIRE AFTERNOON. IT IS POSSIBLE THAT THE SNOW JUST STAYS SOUTH OF
KRST TOO.

.ARX WATCHES/WARNINGS/ADVISORIES...
827 PM CST WED FEB 13 2013

WI...WINTER WEATHER ADVISORY UNTIL NOON CST THURSDAY FOR WIZ017-029.

MN...NONE.
IA...NONE.

SHORT TERM...AJ
LONG TERM...WETENKAMP
AVIATION...AJ

AREA FORECAST DISCUSSION

NWS LA CROSSE WI

724 PM CST WED FEB 13 2013

.SHORT TERM...TONIGHT INTO THURSDAY
555 PM CST WED FEB 13 2013

724 PM UPDATE...IN ADDITION TO THE UPDATE INFORMATION BELOW MADE
AT 555 PM...NOTICED THAT BLENDING THE QPF FOR 06-12Z THURSDAY FROM
THE PREFERRED MODEL GROUP RESULTS IN A NARROW BAND AROUND HIGHWAY
29 INTO SOUTHERN TAYLOR COUNTY UPWARDS OF 0.30 INCHES. SNOW TO
WATER RATIOS...GIVEN ONLY A 75 MB DEEP DENDRITIC GROWTH ZONE
PROGGED...SHOULD END UP MOSTLY IN THAT 13-15 TO 1 RANGE...
RESULTING IN A 6 HOUR PERIOD OF 3-5 INCHES OF SNOW. WE COULD
APPROACH LOW END WARNING CRITERIA IN THIS BAND. AFTER
COLLABORATION WITH GRB...WILL STICK WITH THE ADVISORY FOR NOW
PENDING THE 14.00Z NAM. TOUGHEST PART WITH A WARNING WOULD BE
GRABBING THE RIGHT AREA SINCE THIS WILL BE A NARROW BAND.

UPDATE AT 555 PM...

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
236 PM CST WED FEB 13 2013

.AVIATION...TONIGHT AND THURSDAY
604 PM CST WED FEB 13 2013

.ARX WATCHES/WARNINGS/ADVISORIES...
236 PM CST WED FEB 13 2013

WI...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON CST
THURSDAY FOR WIZ017-029.

MN...NONE.
IA...NONE.

SHORT TERM...AJ
LONG TERM...WETENKAMP
AVIATION...AJ

AREA FORECAST DISCUSSION

NWS LA CROSSE WI

604 PM CST WED FEB 13 2013

.SHORT TERM...TONIGHT INTO THURSDAY
555 PM CST WED FEB 13 2013

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
236 PM CST WED FEB 13 2013

.AVIATION...TONIGHT AND THURSDAY
604 PM CST WED FEB 13 2013

.ARX WATCHES/WARNINGS/ADVISORIES...
236 PM CST WED FEB 13 2013

WI...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON CST
THURSDAY FOR WIZ017-029.

MN...NONE.
IA...NONE.

SHORT TERM...AJ
LONG TERM...WETENKAMP
AVIATION...AJ

AREA FORECAST DISCUSSION

NWS LA CROSSE WI

555 PM CST WED FEB 13 2013

.SHORT TERM...TONIGHT INTO THURSDAY
555 PM CST WED FEB 13 2013

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
236 PM CST WED FEB 13 2013

.AVIATION...
1148 AM CST WED FEB 13 2013

AVIATION DISCUSSION FOR 00Z TAFS COMING SHORTLY. PREVIOUS
DISCUSSION AT 1148 AM...

VFR CONDITIONS WILL PREVAIL UNTIL THIS EVENING AS NEXT SHORT WAVE
TROUGH DROPS THROUGH WESTERN GREAT LAKES IN NORTHWEST FLOW. SOME
DIFFERENCES IN SHORT TERM MODEL GUIDANCE CONTINUE WITH GFS
CONTINUING BIT OF A NORTHERN TRACK AND NAM CLOSER TO CENTRAL
CORRIDOR. PLAYED A SEMI COMPROMISE BRINGING CEILINGS DOWN QUICKLY
THIS EVENING AND DROPPING VISIBILITIES AT ONSET OF SNOW. SOME
QUESTION HOW LOW CONDITIONS WILL GET BUT WOULD EXPECT PERIODS OF IFR
WITH MAIN ACCUMULATION PERIODS OVERNIGHT AND EARLY THURSDAY MORNING.

TRIED TO HINT AT IMPROVING CONDITIONS AFTER FEB 14/15Z WITH PASSAGE
OF WAVE BUT LINGERING TROUGH AND SECONDARY SHORT WAVE TROUGH COULD
BRING SNOW SHOWERS TO VICINITY WELL INTO THURSDAY EVENING.

.ARX WATCHES/WARNINGS/ADVISORIES...
236 PM CST WED FEB 13 2013

WI...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON CST
THURSDAY FOR WIZ017-029.

MN...NONE.
IA...NONE.

SHORT TERM...AJ
LONG TERM...WETENKAMP
AVIATION.....SHEA

AREA FORECAST DISCUSSION

NWS TAMPA BAY RUSKIN FL

335 AM EST THU FEB 14 2013

.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOW BROAD LONGWAVE TROUGHING IN
PLACE OVER MUCH OF THE CONUS. FEATURE EMBEDDED WITHIN THIS LARGER
SCALE FLOW THAT WILL HAVE THE MOST SHORT TERM INFLUENCE IS A
SHORTWAVE IMPULSE EJECTING EASTWARD FROM THE SOUTHERN
PLAINS/NORTHERN MEXICO. THIS FEATURE WILL MOVE SLOWLY EASTWARD
TOWARD THE FL PENINSULA INTO FRIDAY KEEPING OUR AREA WITHIN IN A
REGION OF BROAD SYNOPTIC ASCENT/QG FORCING. WV IMAGERY SHOWS THAT WE
HAVE NO LACK OF MID/UPPER LEVEL MOISTURE STREAMING ACROSS THE
NORTHERN GULF AND CENTRAL/NORTHERN FL PENINSULA FOR THIS BROAD LIFT
TO ACT ON.

AT THE SURFACE...COLD FRONT CONTINUES TO VERY SLOW DRIFT SOUTH AND
EAST INTO THE SOUTHERN FLORIDA PENINSULA. THE BOUNDARY HAS NOW
CLEARED ALL OF OUR FORECAST AREA WITH COOLER AND DRIER LOW LEVEL AIR
TRYING TO FILTER IN FROM THE NORTH. THIS DRY AIR WILL ONLY BE IN THE
VERY LOWEST LEVELS...AND SHOWERS WILL REMAIN IN THE FORECAST...EVEN
IN THE POST-FRONTAL ENVIRONMENT. REGIONAL RADARS...SHOW A SCATTERING
OF LIGHT SHOWER ACTIVITY ACROSS THE REGION EARLY THIS MORNING...WITH
A FEW HEAVIER CELLS DOWN OVER THE SOUTHERN PENINSULA IN CLOSER
PROXIMITY TO THE FRONTAL FOCUS.

.SHORT TERM (TODAY THROUGH SATURDAY)...
TODAY/TONIGHT...
SURFACE BOUNDARY WILL BECOME STALLED THIS MORNING ACROSS THE SE GULF
AND FAR SOUTHERN FL PENINSULA...AND THEN REMAIN IN PLACE THROUGH
TONIGHT. MID/UPPER LEVEL SHORTWAVE IMPULSE WILL GRADUALLY ELONGATE
AND MOVE EASTWARD ACROSS THE NORTHERN GULF TOWARD THE REGION. THE
RAINFALL FORECAST REMAINS A TRICKY ONE AS THE FORCING MECHANISMS ARE
ALL RATHER BROAD WITH NOTHING OBVIOUS TO FOCUS THE LIFT IN ONE PLACE
VS ANOTHER. OVERALL...STILL FEEL THE MOST WIDESPREAD SHOWERS
ACTIVITY WILL EVENTUALLY DEVELOP BY LATER TODAY AND INTO THE
OVERNIGHT ALONG AND TO THE SOUTH OF THE I-4 CORRIDOR...WHERE LARGE
SCALE QG FORCING WILL BECOME COINCIDENT WITH WELL DEFINED DIFFLUENCE
ALOFT...AND AT LEAST SOME LOW LEVEL UPGLIDE TO THE NORTH OF THE
SURFACE BOUNDARY. FOR THIS MORNING...ONE DEPARTING JET STREAK UP THE
EASTERN SEABOARD IS SUPPORTING A SWATH OF GOOD DIVERGENCE ALOFT AND
A BAND OF SHOWERS/RAIN ACROSS APALACHEE BAY AND THE FL BIG BEND.
GUIDANCE SUGGESTS THAT ALTHOUGH THIS DIVERGENCE WILL BE PULLING AWAY
WITH TIME...INCREASING CHANCES FOR SHOWERS WILL ONCE AGAIN ARRIVE
ACROSS OUR NORTHERN NATURE COAST ZONES FOR A TIME THIS MORNING. BY
THE AFTERNOON...THESE DYNAMICS WILL BE ESSENTIALLY GONE AND THINK
THE BEST FOCUS FOR SHOWERS SHIFTS SOUTHWARD. HAVE CHANCE POPS THIS
MORNING FOR ALL WITH A BAND OF LIKELY UP TOWARD LEVY COUNTY FOR
REASONS DISCUSSED ABOVE. THEREAFTER FOR THE AFTERNOON AND EVENING
KEPT CHANCE POPS NORTH OF TAMPA BAY WITH LIKELY TO CATEGORICAL RAIN
CHANCES ALONG THE I-4 CORRIDOR AND SOUTHWARD. TEMPERATURES WILL
DEPEND HIGHLY ON THE EVENTUAL RAINFALL PATTERNS AND ARRIVAL
TIMING...BUT MID 60S FAR NORTH RANGING TO LOWER 70S MID ZONES...AND
MID/UPPER 70S SOUTH SHOULD WORK WELL. LOW TEMPS TONIGHT WILL RANGE
FROM THE 40S FAR NORTH TO THE LOW/MID 50 MID ZONES...AND MID 50S TO
AROUND 60 FAR SOUTH. SOME OF THE STATISTICAL GUIDANCE WANTS TO BRING
TEMPS DOWN INTO THE 30S FAR NORTH...BUT FEEL WITH THE AMOUNT OF
CLOUDS AND POTENTIAL FOR AT LEAST SOME RESIDUAL SHOWERS
ACTIVITY...EVEN AS FAR NORTH AS LEVY COUNTY...THAT 30S ARE UNLIKELY.

FRIDAY/FRIDAY NIGHT...
SHORTWAVE AXIS PASSES TO OUR EAST EARLY IN THE DAY WITH A DECLINE IN
THE LARGE SCALE FORCING. UPPER JET CONFIGURATION FAVORS LESS AND
LESS DIFFLUENCE ALOFT AS WELL. EXPECT A SCATTERING OF SHOWERS TO
STILL BE ONGOING DURING THE MORNING HOURS...ESPECIALLY SOUTH AND
EAST OF TAMPA BAY IN CLOSER PROXIMITY TO THE SURFACE BOUNDARY. THIS
ACTIVITY SHOULD SLOWLY PIVOT EASTWARD AND AWAY FROM OUR ZONES
LATER FRIDAY AND ESPECIALLY FRIDAY EVENING AS A BIG PATTERN CHANGE
FOR THE UPCOMING WEEKEND BEGINS TO RAPIDLY EVOLVE TO OUR NORTHWEST.
SO...SCATTERED SHOWERS (BUT NOT A WASHOUT) EXPECTED FROM TAMPA
BAY/POLK COUNTY SOUTHWARD ON FRIDAY...WITH THIS ACTIVITY ENDING FOR
ALL ZONES DURING FRIDAY NIGHT. UPPER LEVEL PATTERN WILL BE
AMPLIFYING OVER THE EASTERN HALF OF THE NATION ON FRIDAY...WITH A
STRONG SHORTWAVE IMPULSE WORKING DOWN THE BACKSIDE OF THE TROUGH.
THIS ENERGY WILL ACT TO REALLY SHARPEN THE FLOW FRIDAY NIGHT INTO
SATURDAY ACROSS THE SOUTHEASTERN STATES/FL PENINSULA. FIRST BOUNDARY
ASSOCIATED WITH THIS TROUGH LOOKS TO QUICKLY CROSS THE AREA FRIDAY
NIGHT...WITH CAA INTENSIFYING AFTER MIDNIGHT. WILL SEE WIDESPREAD
TEMPS IN THE 40S BY EARLY SATURDAY MORNING. SOME UPPER 30S ARE
LIKELY ACROSS THE NATURE COAST...AND 50S AT THE IMMEDIATE COAST FROM
PINELLAS COUNTY SOUTHWARD.

SATURDAY...
SHARP SHORTWAVE IMPULSE EJECTS ACROSS THE PENINSULA SURGING A
REINFORCING COLD FRONT ACROSS THE AREA DURING THE DAY. THIS FRONT
WILL HAVE A DRY PASSAGE...BUT WILL DELIVER ONE OF THE COLDEST (IF
NOT THE COLDEST) OVERALL LOW LEVEL COLUMNS OF THE WINTER SO FAR.
850MB TEMPS WILL DROP BELOW ZERO ACROSS AT LEAST THE CENTRAL AND
NORTHERN PORTIONS OF THE FORECAST AREA. GFS 850MB TEMPS BY SATURDAY
EVENING ARE ON THE ORDER OF 3-3.5 STANDARD DEVIATIONS BELOW CLIMO
FOR MID FEBRUARY. THE GFS TENDS TO HAVE A COLD BIAS IN ITS 850MB
TEMPS...BUT EVEN TAKING THIS BIAS INTO CONSIDERATION...A BIG COOL
DOWN IN IN STORE FOR THE WEEKEND. WINDS WILL BECOME GUSTY SATURDAY
AFTERNOON BEHIND THIS SECONDARY FRONT...ESPECIALLY CLOSE TO THE
COAST...AND IT WILL FEEL QUITE COOL FOR OUTDOOR ACTIVITIES. MORE ON
THIS BRIEF...BUT SHARP COLD SNAP IN THE LONG RANGE DISCUSSION BELOW.

.LONG TERM (SUNDAY THROUGH NEXT WEDNESDAY)...
THE MAIN STORY IN THE EXTENDED FORECAST CONTINUES TO BE THE COLD
TEMPERATURES OVER THE UPCOMING WEEKEND. WE WILL LIKELY BE DEALING
WITH FREEZING TEMPERATURES FOR PORTIONS OF OUR AREA BOTH SATURDAY
NIGHT AND SUNDAY NIGHT. SATURDAY NIGHT WILL BE AN ADVECTIVE FREEZE
WITH SOME WIND CHILL ISSUES AS WELL. SUNDAY NIGHT WILL BE MORE OF A
RADIATIONAL COOLING FREEZE. TEMPERATURES BOTH NIGHTS COULD END UP
QUITE SIMILAR...BUT IT WILL PROBABLY FEEL COLDER SATURDAY NIGHT WITH
WINDS AROUND 10 MPH. RIGHT NOW EXPECT WIDESPREAD TEMPERATURES
BETWEEN 28 AND 32 DEGREES BOTH NIGHTS FROM ABOUT HERNANDO COUNTY
NORTHWARD. SOUTH OF THERE...I AM LEANING TOWARD MID 30S OVER THE
INTERIOR. IF SKIES STAY CLEAR SUNDAY NIGHT AND WE COMPLETELY
DECOUPLE LEADING TO CALM WINDS...FREEZING TEMPERATURES WILL EXTEND
MUCH FARTHER SOUTH. THIS IS ALL STILL BEYOND 72 HOURS OUT SO NO
WATCHES ARE NEEDED YET AND THERE IS STILL PLENTY OF TIME TO REFINE
THE FORECAST.

AS QUICK AS THE COLD AIR MOVES IN...IT MOVES BACK OUT. SUNDAY WILL
BE THE COLDEST DAY WITH HIGHS ONLY IN THE UPPER 50S TO NEAR 60 FROM
TAMPA BAY NORTH AND IN THE LOWER TO MIDDLE 60S WELL TO THE SOUTH. ON
MONDAY WE WILL BE 10 DEGREES WARMER THAN THAT WHICH BRINGS US BACK
TO NEAR NORMAL. WE WILL BE IN A VERY PROGRESSIVE PATTERN THROUGH
MID-WEEK AND BEYOND WITH COLD FRONTS ARRIVING ABOUT EVERY THIRD DAY.
THE NEXT CHANCE OF RAIN WILL BE LATE TUESDAY AND TUESDAY NIGHT
FOLLOWED BY DRIER...AND SOMEWHAT COOLER AIR ON WEDNESDAY.

.AVIATION...
THE LAST BATCH OF HEAVIER SHOWERS IS MOVING THROUGH FMY AND RSW NOW.
THE REST OF THE REGION SHOULD SEE MAINLY VFR CONDITIONS THROUGH MID
AFTERNOON OR SO. RAIN IS EXPECTED TO REDEVELOP OVER THE GULF LATER
WHICH SHOULD BRING MVFR CEILINGS TO ALL TERMINALS THROUGH THE
EVENING HOURS. THE NORTHERN TERMINALS HAVE THE BEST CHANCE AT
RETURNING TO VFR AFTER 00Z WHILE THE SOUTHERN TERMINALS COULD SEE AN
EXTENDED PERIOD OF MVFR OR PERHAPS EVEN IFR CEILINGS LASTING INTO
THE MORNING HOURS FRIDAY.

.MARINE...
FRONTAL BOUNDARY WILL STALL JUST SOUTH OF THE FORECAST WATERS
THROUGH FRIDAY HELPING TO KEEP PERIODS OF RAIN/SHOWERS ACROSS THE
EASTERN GULF THE NEXT 24 HOURS. NORTH TO NORTHEAST FLOW WILL
OCCASIONALLY APPROACH CAUTIONARY LEVELS...ESPECIALLY SOUTH OF TAMPA
BAY THROUGH THIS EVENING WITH ALL ZONES REMAINING BELOW HEADLINE
CRITERIA ON FRIDAY. ANOTHER STRONGER BUT DRY FRONT WILL QUICKLY MOVE
THROUGH THE EASTERN GULF OF MEXICO FRIDAY NIGHT AND SATURDAY MORNING
WITH WINDS AND SEAS RAPIDLY BUILDING TO ADVISORY LEVELS FROM THE
NORTHWEST FOR MUCH OF SATURDAY AND SATURDAY NIGHT. WINDS AND WAVES
WILL GRADUALLY SUBSIDE INTO SUNDAY AS HIGH PRESSURE BUILDS OVER THE
REGION.

.FIRE WEATHER...
RELATIVE HUMIDITY WILL REMAIN WELL ABOVE CRITICAL LEVELS TODAY. THE
ONE CONCERN WILL HOWEVER BE FOR LOW DISPERSION INDICES THROUGH THE
DAY. SOMEWHAT DRIER AIR WILL BEGIN TO ARRIVE OVER THE NORTHERN ZONES
FOR FRIDAY AND A BRIEF PERIOD OF RELATIVE HUMIDITY BELOW 35 PERCENT
IS POSSIBLE FOR LEVY/CITRUS AND SUMTER COUNTIES. DESPITE THE DRY AIR
UP NORTH...ERC VALUES ARE LOW...AND DISPERSION INDICES WILL REMAIN
LOW AS WELL. THESE CONDITIONS SHOULD PREVENT ANY RED FLAG CONDITIONS
FROM BEING MET. MUCH DRIER AIR ARRIVES FOR ALL ZONES ON SATURDAY...
ALONG WITH GUSTY NORTHWEST WINDS BY THE AFTERNOON HOURS. WILL NEED
TO MONITOR CONDITIONS CLOSELY FOR SATURDAY AS LOW RELATIVE
HUMIDITY...GUSTY WINDS...AND HIGH DISPERSIONS MAY ALLOW FOR SOME
BRIEF RED FLAG CONDITIONS.

PRELIMINARY POINT TEMPS/POPS...
TPA 69 55 69 51 / 80 50 30 10
FMY 76 62 73 55 / 90 70 50 30
GIF 72 53 71 47 / 80 60 30 10
SRQ 69 56 70 52 / 80 60 30 20
BKV 68 50 70 41 / 60 50 20 10
SPG 68 58 69 56 / 80 60 30 10

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR CHARLOTTE-
LEE.

GULF WATERS...NONE.

SYNOPSIS/SHORT TERM/MARINE/FIRE WEATHER...MROCZKA
LONG TERM/AVIATION/DECISION SUPPORT SERVICES...JILLSON

AREA FORECAST DISCUSSION

NWS JACKSON KY

1250 AM EST THU FEB 14 2013

.UPDATE...
ISSUED AT 1250 AM EST THU FEB 14 2013

UPDATED THE FORECAST TO ADJUST THE CLOUD COVER FOR SOME ANTICIPATED
LOW LEVEL STRATO CU. COVERAGE SHOULD SLOWLY SPREAD SPREAD WEST
THROUGH THE NIGHT NIGHT BEFORE LIFTING AFTER 12Z. OTHERWISE THE
FORECAST IS ON TRACK.

UPDATE ISSUED AT 1006 PM EST WED FEB 13 2013

PRECIP SHOULD BE DONE FOR THE NIGHT AND IS REMOVED FROM THE 1ST
PERIOD FORECAST. CLOUDS WILL BE TRICKY...BUT SHOULD GENERALLY BE MOST
PREVALENT IN THE SE AND LEAST IN THE NW OVERNIGHT.

UPDATE ISSUED AT 655 PM EST WED FEB 13 2013

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 231 PM EST WED FEB 13 2013

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM EST WED FEB 13 2013

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1250 AM EST THU FEB 14 2013

THE MAIN CONCERN FOR THE FIRST 6 HOURS OF THE TAF PERIOD IS SOME LOW
LEVEL STRATO CU THAT IS EXPECTED TO DEVELOP OVER THE SOUTH AND
EASTERN KENTUCKY. THE MVFR AND IFR CEILINGS WILL LIFT TO ABOUT 5 KFT
AFTER 12Z. DURING THE DAY...WINDS UP TO 20 KNOTS OUT OF THE NORTHWEST
WILL MIX TO THE SURFACE BEFORE TAPERING OFF BY 23Z.

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...SHALLENBERGER
SHORT TERM...DUSTY
LONG TERM...SBH
AVIATION...SHALLENBERGER

AREA FORECAST DISCUSSION

NWS MARQUETTE MI

449 AM EST THU FEB 14 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 448 AM EST THU FEB 14 2013

ATTENTION INITIALLY THIS MORNING IS ON THE LOW TRACKING THROUGH
WISCONSIN THAT WILL TRACK TO THE EAST-NORTHEAST AND INTO NORTHERN
LOWER MICHIGAN THIS MORNING. FORTUNATELY...MODELS HAVE COME INTO
MUCH BETTER AGREEMENT ON THE TRACK OF THIS LOW FROM 24 HOURS AGO.

STRONG SHORTWAVE NOTED ON WV IMAGERY IN SOUTHWEST WISCONSIN WITH A
SECONDARY WAVE UPSTREAM IN NORTH DAKOTA. THIS SECONDARY WAVE WILL BE
THE ONE THAT AMPLIFIES THE TROUGH OVER THE GREAT LAKES AND LEADS TO
BELOW NORMAL TEMPERATURES AND LAKE EFFECT FOR TONIGHT INTO
SATURDAY. BOTH THE LOW AND SHORTWAVE HAVE STARTED TO SHIFT MORE TO
THE EAST IN THE LAST HOUR OR TWO...AS THE MODELS HAVE SHOWN. THIS
LEADS TO A LITTLE MORE CONFIDENCE ON THE TRACK OF THE LOW AND
ASSOCIATED PRECIPITATION ON THE NORTH SIDE FOR THIS MORNING.

FAIRLY BROAD AREA OF LIGHT TO MODERATE SNOW ACROSS CENTRAL AND
NORTHEAST WISCONSIN AS OF 4AM...WITH LIGHT SNOW OVER SOUTH CENTRAL
UPPER MICHIGAN. USING LATEST RADAR DATA...IT APPEARS THIS STRONGEST
PRECIPITATION IS TIED TO THE 900-800MB FGEN AND FN
CONVERGENCE...WITH THE BROAD AREA OF LIGHT SNOW IN THE 750-650MB
FGEN/Q-VECTOR CONV. TRACKING THIS TO THE EAST-NORTHEAST WITH THE
LATEST RAP AND GFS/NAM...WOULD EXPECT THE LIGHT SNOW TO SLIDE
ACROSS LOCATIONS SOUTHEAST OF WATERSMEET TO GWINN TO SENEY THROUGH
THE MORNING HOURS. THE HEAVIEST SNOW SHOULD FOCUS OVER THE SOUTHERN
HALF/THIRD OF MENOMINEE COUNTY FROM 12-17Z. 00Z NAM ACTUALLY
KEPT THAT BEST FGEN AREA JUST SOUTH OF THE CWA...BUT THE 06Z RUN
AND LATEST RAP/HRRR WOULD SUPPORT THE BEST SNOW ALONG AND
SOUTH OF A LINE FROM ATHELSTANE WISCONSIN...TO BAGLEY...TO THE
MENOMINEE/DELTA COUNTY LINE. SNOW RATIOS SHOULD BE AROUND 13 TO 1
WITH THE NARROW DGZ AND MUCH OF THE LOWER LEVEL FORCING AT OR
BELOW THE DGZ. THUS...WITH QPF AMOUNTS TOWARDS 0.25-0.35 IN
THAT HEAVIEST BAND...WOULD EXPECT THE SOUTHERN HALF OF MENOMINEE
COUNTY TO SEE 2-4 INCHES OF SNOW. THE CITY OF MENOMINEE WOULD HAVE
THE BEST OPPORTUNITY FOR SLIGHTLY HIGHER AMOUNTS TOWARDS
5 INCHES...DEPENDING ON WHERE THAT HEAVIEST BAND TRACKS THROUGH
NORTHEAST WISCONSIN. WILL LEAVE THE ADVISORY AS IS SINCE THINKS LOOK
TO BE IN DECENT SHAPE WITH THE TRACK OF THE HEAVIEST PRECIPITATION
AND TIMING. ONE FINAL NOTE...THE RAP/HRRR DO BRING SOME OF THE
HEAVIER SNOW INTO FAR SOUTHERN DELTA/SCHOOLCRAFT COUNTIES FOR
LOCATIONS RIGHT ALONG LAKE MICHIGAN...BUT WILL WAIT TO SEE HOW
THINGS EVOLVED BEFORE ISSUING AN SPS.

AS THIS LOW SHIFTS TO THE EAST...EXPECT NORTHWESTERLY FLOW TO
SLOWLY DROP 850MB TEMPS TOWARDS -17C BY 00Z FRIDAY. WITH LAKE
SUPERIOR TEMPS IN THE 1-2C RANGE...EXPECT LAKE SOME LAKE
ENHANCEMENT FOR THE FIRST PART OF THE DAY IN NORTHERLY WIND FAVORED
LOCATIONS OVER THE WEST AND NORTH CENTRAL. THIS WILL TRANSITION TO
PURE LAKE EFFECT BY EVENING AS THE DEEPER MOISTURE DEPARTS AND
DELTA-T VALUES PUSH TOWARDS 18. EVEN THOUGH CONDITIONS BECOME
FAVORABLE THIS EVENING AND THROUGH THE NIGHT...THERE IS SOME
CONCERN IN THE AMOUNT OF SNOW THAT WILL FALL. THIS IS DUE TO THE
DRY AIR WORKING IN BEHIND THE LOW...WHICH WILL KEEP INVERSION
HEIGHTS TOWARD 5KFT OR EVEN LOWER IF OUR LOCAL WRF RUNS ARE
CORRECT. A LINGERING TROUGH OVER THE EASTERN LAKE FROM THE LOW WILL
LEAD TO WINDS OUT OF THE NNW TONIGHT AND HAVE FOLLOWED LOCAL
CLIMATOLOGY POPS.

EXPECT THE LAKE EFFECT TO BE BEST TONIGHT OVER THE WEST
FIRST...ESPECIALLY TOWARDS WESTERN GOGEBIC/ONTONAGON COUNTIES WHERE
THERE IS A SLIGHTLY LONGER FETCH AND THEN INCREASING OVERNIGHT OVER
THE EAST AS THE COLDER AIR ARRIVES AND PUSHES THE CLOUD IN THE DGZ.
LAKE ENHANCEMENT TODAY SHOULD HAVE LOWER SNOW RATIOS...IN THE MID
TEENS...BUT AS THE COLDER AIR ARRIVES TONIGHT MUCH OF THE CLOUD
WILL BE WITHIN THE DGZ AND EXPECT RATIOS TO RISE TOWARDS 30-1 BY
FRIDAY MORNING. WOULD THINK THE VERY FLUFFY NATURE OF THE SNOW WILL
TRY TO OFFSET THE LOWER INVERSION HEIGHTS AND STILL PUSH VALUES
TOWARDS LOW END ADVISORY AMOUNTS BY FRIDAY MORNING IN THE LONGER
FETCH AREAS...GOGEBIC/ONTONAGON/ALGER. SINCE IT WILL MAINLY BE
DURING THE OVERNIGHT HOURS AND LIMITED IMPACT WITH THE
FLUFFINESS...WILL NOT ISSUE AN ADVISORY AT THIS POINT.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 448 AM EST THU FEB 14 2013

AN ACTIVE PATTERN WILL BE THE RULE ACROSS THE CONUS THRU THE LONG
TERM AND PROBABLY RIGHT THRU THE END OF THE MONTH. SPLIT FLOW WILL
GENERALLY DOMINATE WITH AN ENERGETIC SRN STREAM THOUGH FLOW WILL BE
MORE CONSOLIDATED AT TIMES. AS IT HAS FOR DAYS...GFS LONG RANGE RUNS
CONTINUE TO SHOW A SERIES OF POTENTIALLY SIGNIFICANT SRN STREAM
SYSTEMS MOVING ACROSS THE CONUS THRU THE END OF THE MONTH. WHETHER
ANY OF THESE SYSTEMS LIFT FAR ENOUGH N AND/OR PHASE WITH THE NRN
STREAM TO BRING A SIGNIFICANT STORM SYSTEM INTO THE UPPER GREAT
LAKES REMAINS TO BE SEEN. ONE THING THAT MAY EVENTUALLY FAVOR THE
STORM TRACK PROGRESSIVELY SHIFTING NW WITH TIME ACROSS THE CONUS...
ALLOWING SYSTEMS TO LIFT FARTHER N AND W FROM THE SRN ROCKIES...IS
THE MJO WHICH HAS BEEN ACTIVE SINCE EARLY JAN. WHILE THE RECENT
PHASE OF THE MJO HAS BEEN SUPPORTIVE OF COLDER WEATHER OVER THE
GREAT LAKES...THAT WILL CHANGE OVER THE NEXT COUPLE OF WEEKS AS THE
SHIFTING MJO PHASE BEGINS TO FAVOR RIDGING/WARMER CONDITIONS OVER
THE ERN CONUS AND TROFFING/COLDER WEATHER OVER THE W. THIS WOULD AT
LEAST SUPPORT A TENDENCY FOR ACTIVE SYSTEMS TO LIFT INTO THE GREAT
LAKES LATER THIS MONTH. FOR UPPER MI...THE LONG TERM PORTION OF THE
FCST TODAY STILL DOESN`T APPEAR TO OFFER ANY SIGNIFICANT SYSTEMS...
BUT THERE WILL BE ONE TO WATCH JUST BEYOND THE TIME PERIOD OF THIS
FCST AT THE END OF NEXT WEEK. BEHIND THE CLIPPER MOVING THRU THE
GREAT LAKES TODAY...INFLUX OF ARCTIC AIR UNDERNEATH DEEPENING
MID/UPPER TROF WILL LEAD TO LES THRU AT LEAST THE FIRST HALF OF THE
WEEKEND. MODERATION WILL OCCUR BRIEFLY EARLY NEXT WEEK. THEN...A NEW
TROF AMPLIFYING INTO THE CNTRL/ERN CONUS WILL BRING THE POTENTIAL
FOR A PHASING SYSTEM OVER THE GREAT LAKES/ERN CONUS EARLY NEXT WEEK.
HOW MUCH IMPACT THAT SYSTEM WILL HAVE OVER UPPER MI REMAINS TO BE
SEEN.

MID/UPPER LEVEL TROF WILL BE STEADILY DEEPENING OVER THE GREAT LAKES
FRI/FRI NIGHT...AND WITH 850MB TEMPS AROUND -20C...LES WILL BE THE
RULE DOWNWIND OF LAKE SUPERIOR. AT THE LOW-LEVELS...GENERAL
NORTHWEST WINDS FRI WILL SHIFT A LITTLE MORE NORTHERLY FRI NIGHT.
LAND BREEZES...ESPECIALLY FRI NIGHT/SAT MORNING...WILL HAVE SOME
INFLUENCE ON THE WIND FIELD AND WILL SERVE TO FOCUS HEAVIER LES.
INITIALLY...INVERSION FRI MORNING WILL BE AROUND 4-5KFT...BUT WILL
STEADILY RISE UNDER DEEPENING MID LEVEL TROF...REACHING 8-10KFT FRI
NIGHT. INVERSION MAY EVEN DISAPPEAR FOR A TIME FRI NIGHT PER GFS/NAM
FCST SOUNDINGS AS TROF REACHES ITS DEEPEST OVER THE UPPER LAKES.
SO...EXPECT A STEADY INCREASE IN LES INTENSITY FRI...AND THEN SNOW
WILL PROBABLY BECOME HVY AT TIMES FRI NIGHT...IN PARTICULAR WHERE
CONVERGENCE ZONES SET UP DUE TO LAND BREEZES. ALTHOUGH DGZ WILL BE
PUSHED TOWARD THE SFC BY THE COLDER AIR OVER THE AREA...NAM FCST
SOUNDINGS SHOW SUFFICIENT LAKE MODERATION TO KEEP DGZ AT LEAST IN
THE LOWER PORTION OF THE CONVECTIVE LAYER. LONGER FETCH ACROSS THE E
HALF OF LAKE SUPERIOR INTO NCNTRL UPPER MI SHOULD HELP KEEP DGZ
HIGHER AND BETTER POSITIONED IN THE CONVECTIVE LAYER. AS A RESULT...
EXPECT SNOW TO WATER RATIOS TO END UP AROUND 30 TO 1. AT THIS
POINT...EXPECT ADVY LEVEL LES FOR THE MOST PART IN THE SNOWBELTS
FAVORED BY NW WINDS FRI. SNOWFALL COULD THEN PUSH WARNING CRITERIA
FRI NIGHT OVER GOGEBIC/ONTONAGON COUNTIES AND MORE SO OVER ALGER/NRN
SCHOOLCRAFT COUNTIES AND PERHAPS FAR ERN MARQUETTE COUNTY DEPENDING
ON HOW LAND BREEZE CONVERGENCE EVOLVES FRI NIGHT/SAT MORNING. SINCE
POTENTIAL FOR WARNING AMOUNTS (8 INCHES OR MORE IN 12HRS OR 12 OR
MORE IN 24HRS) IS FAIRLY HIGH FOR ALGER/NRN SCHOOLCRAFT...WILL ISSUE
A LAKE EFFECT SNOW WATCH THERE FOR FRI THRU SAT MORNING. IN THE
OTHER AREAS AFFECTED BY LES...ADVYS WILL PROBABLY WORK OUT. GIVEN
THAT IT`S 3RD PERIOD...ESPECIALLY LATER 3RD PERIOD THAT SNOW REALLY
PICKS UP...INTO A 4TH PERIOD EVENT...WILL NOT ISSUE ADVYS WITH THIS
FCST ISSUANCE.

SAT/SAT NIGHT...MID/UPPER TROF SHIFTS E AND SFC HIGH PRES RIDGE
PUSHES INTO THE WRN GREAT LAKES. UNDER RISING HEIGHTS...INVERSIONS
WILL FALL...RESULTING IN LES INTENSITY QUICKLY DIMINISHING W TO E.
AS WINDS BACK W THEN SW SAT AFTN/SAT NIGHT...LINGERING LES WILL
SHIFT...EVENTUALLY MOVING OUT OF THE FCST AREA...BUT PROBABLY NOT
UNTIL LATE SAT NIGHT OVER THE NE. WITH A POTENTIAL PERIOD OF CLEAR
SKIES/CALM WIND AS SFC HIGH PASSES OVER THE AREA SAT NIGHT...TEMPS
COULD TANK. DROPPED MINS CONSIDERABLY FROM PREVIOUS FCST TO -10 TO
-15F IN THE TRADITIONAL INTERIOR COLD SPOTS OVER THE W HALF. COULD
BE SIMILAR READINGS OVER THE E IF CLEARING SPREADS THAT FAR E.
IF THERE ENDS UP BEING SEVERAL HRS OF CLEAR SKIES/CALM WINDS...SOME
TRADITIONAL COLD SPOTS MAY FALL BLO -20F.

SUN...MID LEVEL RIDGE WILL BUILD INTO THE GREAT LAKES DOWNSTREAM OF
NEXT TROF AMPLIFYING S INTO THE ROCKIES/WRN PLAINS. FAIRLY STRONG
WAA PATTERN COULD LEAD TO SOME -SN SUN...BUT ECWMF/GFS HOLD
STRONGEST WAA OFF TO THE W AND NW OF UPPER MI. SO...WILL PLAN FOR A
DRY DAY SUN.

TROF DIGGING INTO THE ROCKIES/WRN PLAINS SUN WILL SHIFT E...REACHING
THE MISSISSIPPI VALLEY MON...THE GREAT LAKES TUE AND NEW ENGLAND
WED. TROF TAKES ON A NEGATIVE TILT AFTER PASSING THE WRN GREAT
LAKES...SO WOULD EXPECT THE MORE SIGNIFICANT PCPN WITH THE TROF TO
BE E OF HERE. NONETHELESS...THERE COULD BE SOME ACCUMULATING SNOW AS
THE SYSTEM PASSES ACROSS THE AREA MON...DEPENDING ON HOW QUICKLY THE
ASSOCIATED SFC LOW ORGANIZES AND WHAT TRACK IT TAKES. RIGHT NOW...IT
APPEARS THE SFC LOW WILL TRACK ACROSS UPPER MI WHICH SHOULD KEEP
HEAVIER SNOW TO THE N OF HERE. HOWEVER...SINCE THIS SYSTEM IS
SEVERAL DAYS OUT...INTENSITY/TRACK OF SYSTEM COULD CHANGE QUITE A
BIT. WHAT IS MORE CERTAIN IS THAT ARCTIC AIR WILL AGAIN DUMP INTO
THE UPPER LAKES MON NIGHT/TUE ON NORTHERLY WINDS...BRINGING ANOTHER
ROUND OF LES DOWNWIND OF LAKE SUPERIOR. RAISED POPS WELL ABOVE
CONSENSUS TO LIKELY/CATEGORICAL TO REFLECT THE GOOD RUN-TO-RUN
CONSISTENCY OF MEDIUM RANGE GUIDANCE ON THE MAGNITUDE OF THE
INCOMING COLD THAT WILL BE MUCH MORE THAN SUFFICIENT FOR LES. LES
WILL GRADUALLY WIND DOWN WED AS TROF DEPARTS AND RIDGE BUILDS INTO
THE UPPER MISSISSIPPI VALLEY.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1222 AM EST THU FEB 14 2013

CMX/IWD...EXPECT MVFR CONDITIONS TO PREDOMINATE AT THESE LOCATIONS
THRU THIS MRNG WITH AREA OF HEAVIER SN ON NRN FLANK OF CLIPPER LO
MOVING INTO WI REMAINING TO THE S. AS COLDER AIR ARRIVES THIS AFTN
ON THE HEELS OF A GUSTY NNW WIND...EXPECT SOME LES TO DVLP WITH VSBY
FALLING TO IFR UNDER SOME OF THE HEAVIER SHSN...ESPECIALLY AT IWD
WITH LONGER FETCH/MORE FVRBL UPSLOPE FLOW.

SAW...EVEN THOUGH HEAVIER SN ASSOCIATED WITH CLIPPER LO MOVING THRU
WI WL REMAIN TO THE S...EXPECT IFR CONDITIONS TO PREDOMINATE THRU
THIS MRNG WITH UPSLOPE NNE FLOW OFF LK SUP BRINGING LO CLDS/SOME
-SN. CONDITIONS WL IMPROVE TO MVFR LATER TDAY AS THE FLOW BACKS
SUFFICIENTLY TO A DOWNSLOPING NNW FLOW.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EST THU FEB 14 2013

A LOW PRESSURE SYSTEM MOVING THROUGH WISCONSIN THIS MORNING WILL
SHIFT EAST TO QUEBEC TONIGHT AND LEAD TO INCREASING NORTHERLY WINDS
THIS AFTERNOON. EXPECT MOST LOCATIONS TO BE IN THE 20-30KT
RANGE...BUT THERE COULD BE A FEW GALE FORCE GUSTS TO 35 KNOTS OVER
THE CENTRAL PART OF LAKE SUPERIOR. COLDER AIR AND PERSISTENT NORTH
TO NORTHWEST WINDS TONIGHT INTO SATURDAY MORNING WILL LEAD TO HEAVY
FREEZING SPRAY AND HAVE ISSUED A HEAVY FREEZING SPRAY WARNING FOR
PORTIONS OF LAKE SUPERIOR. HIGH PRESSURE WILL THEN BUILD IN ON
SATURDAY AND SUNDAY FROM THE NORTHERN PLAINS AND DECREASE THE WINDS
BELOW 15KTS. THEN AS A LOW PRESSURE SYSTEM APPROACHES LAKE SUPERIOR
ON SUNDAY AND MOVES THROUGH ON MONDAY...EXPECT SOUTHERLY WINDS TO
INCREASE TO 20-25KTS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM FRIDAY MORNING THROUGH SATURDAY
AFTERNOON FOR MIZ006-085.

WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MIZ012.

LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 AM EST
SATURDAY FOR LSZ264>266.

LAKE MICHIGAN...
NONE.
&&

SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...KC
MARINE...SRF

AREA FORECAST DISCUSSION

NWS GREAT FALLS MT

1100 PM MST Wed Feb 13 2013

.DISCUSSION...
Update forthcoming. Cold front has pushed through the Great Falls
area and areas of snow have developed behind the front. Radar
indicating a couple of bands of snow located just north of Great
Falls and moving northwest to southeast. This band is slowly sagging
south. RUC analysis indicates heaviest snow should fall between now
and midnight with snow tapering off after that. Have raised pops and
snow amounts for portions of North Central Montana. Emanuel

.AVIATION...
Updated 0600Z.
A moist northwest flow aloft will continue over Montana through
Thursday. Scattered showers can be expected around terrain across
Central Montana through about 12z. Activity diminishes early morning
over most of Montana before skies clear out a bit through the middle
of the day. Expect mid and upper clouds to increase later afternoon
Thursday before another possible round of evening showers.

.PREV DISCUSSION...Issued 248 PM MST Wed Feb 13 2013

Wednesday through Friday...Convective activity continues to
develop and move across Central and North Central Montana with
showers slowly moving southward into the Mountains of Southwest
Montana. Convective activity should continue into the evening
hours but diminish significantly by sunset when daytime heating no
longer drives the thermal activity. Temperatures decrease back
towards seasonal averages tonight behind the cold front. High
temperatures will be limited as the cool air mass slowly
moderates over the next 24 hours. Some moisture aloft will allow
for the possibility of snow showers over the higher terrain
through Thursday night...however no significant accumulations are
expected...especially at the lower elevation. An upper level ridge
will begin to move into the region by Friday and allow for drier
and warmer conditions to again develop throughout the day...with
temperatures rising back above seasonal averages. Suk

Friday night through Wednesday night...Good consistency continues
among the models for this period. An upper level ridge of high
pressure building into Montana Friday night and Saturday will keep
the area mostly dry and quite mild (10 to 15 degrees above normal -
with highs on Saturday reaching into the 40s to lower 50s). A
shortwave trough will flatten the ridge as it moves into the area
from the Pacific Northwest coast on Saturday, bringing a chance of
showers to the Rocky Mountain Front and increasing westerly
downslope winds to the remainder of the area. This shortwave will
then move southeast through the area Saturday night into Sunday with
an associated Canadian cold front. The chance for precipitation will
increase Saturday night, while models continue to bring widespread
light snow to the area on Sunday. Have therefore increased the
chance for precipitation a bit more through these periods.
Temperatures will be quite cool with the frontal passage on Sunday,
as highs will only reach into the upper 20s to mid 30s most areas.
Forecast snowfall amounts are fairly light at this time (with most
lower elevations only forecast to receive an inch or 2 of snow).
However, this situation will continue to be monitored for potential
winter weather highlights, as the warm-up prior to the snow may warm
pavement enough that initially melting snow may refreeze with the
passage of the cold front, causing icy roadways. This may become a
situation similar to that from this past weekend. An upper level
ridge of high pressure will then follow this system into the state
Sunday night through Monday night, allowing temperatures to warm
back closer to normal with a decreasing chance of snow. A deep
upper level trough of low pressure will then move across the western
CONUS Tuesday night through Wednesday. The trough is forecast to
split somewhat, with the southern portion taking the bulk of the
energy south of the area. Despite this, a low level easterly flow
may bring enough moisture into the southern half of the state to
allow a good chance of snow to develop across central/southwest
Montana. Coulston

.PRELIMINARY POINT TEMPS/POPS...
GTF 21 35 21 42 / 100 10 10 10
CTB 16 34 21 41 / 30 10 10 10
HLN 25 35 22 40 / 40 30 20 10
BZN 20 31 16 36 / 60 40 30 10
WEY 10 24 6 29 / 60 30 40 10
DLN 20 32 17 37 / 30 30 20 10
HVR 10 27 9 31 / 20 10 10 10
LWT 16 28 14 34 / 100 30 10 10

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

weather.gov/greatfalls

AREA FORECAST DISCUSSION

NWS GREAT FALLS MT

910 PM MST Wed Feb 13 2013

.AVIATION...
Updated 0040Z.
A moist northwest flow aloft will continue over Montana through
Thursday. Scattered showers can be expected around terrain across
Central Montana. Activity diminishes overnight but small areas of
light snow may persist across some valley locations in the forecast
area. Expect local MVFR conditions and mountain obscurations through
12Z in these locations. Precipitation expected to mostly end with
cloud cover decreasing from the north after 12Z.

.PREV DISCUSSION...Issued 248 PM MST Wed Feb 13 2013

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

weather.gov/greatfalls

AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

328 AM CST THU FEB 14 2013

.DISCUSSION...

NEAR TERM...TODAY AND TONIGHT.

SCATTERED SNOW SHOWERS DEVELOP TODAY THROUGH THIS EVENING WITH THE
PASSAGE OF AN ARCTIC FRONT. WINDS AHEAD AND BEHIND THE FRONT SHOULD
REACH WIND ADVISORY CRITERIA. STEEP LAPSE RATES TO 600-700MB SUPPORT
THE WIND AND CONVECTIVE PCPN. THE RUC AND OTHER MODELS SUPPORT
STRATUS WHICH COULD PERSIST INTO TONIGHT ACROSS THE NORTH.

TEMPERATURES THIS AFTN WILL BE CONTINGENT ON THE FRONTAL PASSAGE.
THE HRRR AND RAP MODELS SHOWS 40S SOUTH AND 30S NORTH. A BLEND OF
GEM AND NAM WAS THE BASIS FOR THE FCST WHICH GIVES A SIMILAR EFFECT.
NEITHER THE RAP OR HRRR FCST MAX TEMPS...JUST HOURLY.

WINDS AND TEMPS DROP TONIGHT AS THE ARCTIC HIGH BUILDS THROUGH THE
UPPER MISSOURI BASIN AND PACIFIC HIGH PRESSURE BUILDS THROUGH THE
HIGH PLAINS. ALL MODELS SHOW LOW PRESSURE DEVELOPING ACROSS ERN SD
SIGNALING A REINFORCING COLD FRONT FOR FRIDAY.

SHORT TERM...12Z FRIDAY THROUGH 12Z SUNDAY.

BROAD CYCLONIC FLOW ACROSS THE NORTHERN AND CENTRAL PLAINS WILL
REMAIN ON FRIDAY...WITH AN ADDITIONAL SHORTWAVE IMPULSE DIVING
SOUTH THROUGH AMPLIFIED NORTHWESTERLY FLOW. DUE TO FAVORABLE UPPER
JET DYNAMICS AND THE FACT THAT LOW LEVEL LAPSE RATES REMAIN STEEP
WITHIN A SATURATED DENDRITIC LAYER...WILL MAINTAIN -SN AND
FLURRIES ACROSS THE ENTIRE CWA ON FRIDAY. THE IMPULSE QUICKLY
DROPS TO THE SOUTH WITH A WARM FRONT PUSHING WEST TO EAST FRIDAY
NIGHT INTO SATURDAY...TEMPERATURES SHOULD START TO MODERATE...WITH
HIGHS APPROACHING 50 SOUTH OF INTERSTATE 80 AND ACROSS THE EASTERN
PANHANDLE.

LONG TERM...12Z SUNDAY AND BEYOND.

SHORTWAVE RIDGING ACROSS THE REGION WILL GIVE WAY TO PROGRESSIVE
ZONAL FLOW AS A TROUGH ADVANCES ACROSS THE NORTHERN ROCKIES ONTO
THE PLAINS. IN ADVANCE OF THE TROUGH...SURFACE LOW PRESSURE OVER
THE HIGH PLAINS WILL DEEPEN THROUGHOUT THE DAY ON
SUNDAY...ALLOWING FOR WESTERLY TO SOUTHWESTERLY WIND WHICH WILL
HELP WARM TEMPERATURES. LOOKING AT MID TO UPPER 50S GENERALLY OVER
THE SOUTHERN HALF OF THE CWA...AND WHERE SNOW REMAINS...MID 40S
SEEM PLAUSIBLE. THE WAVE WILL EVENTUALLY DRAG A COLD FRONT THROUGH
THE CWA EARLY ON MONDAY...AT THIS TIME NOT SEEING MUCH SUPPORT FOR
PRECIPITATION PRODUCTION...BUT HIGHS WILL BE SOME 15-20 DEGREES
COOLER. THE NEXT IN LINE OF SHORTWAVE RIDGING ARRIVES EARLY TO
MIDDLE NEXT WEEK...HOWEVER WE WILL BE RECYCLING SOME COLDER AIR
BACK FROM THE EAST...SO A WARM UP MAY BE MODERATED SOMEWHAT.
ATTENTION THEN TURNS TO THE NEXT SIGNIFICANT TROUGH WHICH SHOULD
BE LOCATED ACROSS THE GREAT BASIN AROUND 12Z ON WEDNESDAY.
SURPRISINGLY...THERE IS BETTER THAN AVERAGE CONTINUITY/AGREEMENT
BETWEEN THE LONGER RANGE SOLUTIONS AND SEVERAL ENSEMBLE
MEMBERS...WHICH SUGGEST A POTENTIALLY SIGNIFICANT STORM FOR THE
CWA...SIMILAR TO THE TRACK OF LAST WEEKEND/S SYSTEM. ONE
DIFFERENCE IS THAT THE MODELS ARE SHOWING SOME NEGATIVELY TILTED
TENDENCIES WITH THE OVERALL SYSTEM...ALLOWING FOR A MUCH LONGER
PERIOD OF QPF ACROSS THE CWA...INTERESTING. THAT BEING SAID...THE
POTENTIAL SYSTEM IS SEVEN DAY/S OUT...SO WON`T GET TOO EXCITED
YET. THUS WILL LIMIT POPS AT 30 PERCENT /OR LESS/ FOR NOW.

.AVIATION...

MVFR WILL SPREAD INTO NRN NEB THIS AFTN WITH THE PASSAGE OF AN
ARCTIC FRONT CURRENTLY AT 08Z NEAR KGGW. SCATTERED SNOW SHOWERS WILL
ACCOMPANY THE FRONT. MVFR AND ISOLATES SNOW SHOWERS MAY PERSIST
TONIGHT ACROSS THE NORTH. ELSEWHERE MOSTLY VFR IS EXPECTED WITH
ISOLATED RAIN OR SNOW SHOWERS DURING THE DAY TODAY.

.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY FROM 10 AM CST
/9 AM MST/ THIS MORNING TO 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ004>010-022>029-035>038-056>059- 069>071-094.

SHORT TERM/LONG TERM...JACOBS
NEAR TERM/AVIATION....CDC

AREA FORECAST DISCUSSION

NWS LA CROSSE WI

1126 PM CST WED FEB 13 2013

.SHORT TERM...TONIGHT INTO THURSDAY
827 PM CST WED FEB 13 2013

MAIN UPDATE AT 555 PM...

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
236 PM CST WED FEB 13 2013

.AVIATION...THROUGH 06Z FRIDAY
1126 PM CST WED FEB 13 2013

BAND OF RAIN AND SNOW HAS MOVED THROUGH KRST AND HAS ALMOST
CLEARED KLSE...ASSOCIATED WITH A WARM FRONT. LOWER MVFR CEILINGS
ARE COMING IN BEHIND THIS BAND. TO THE NORTHWEST...ANOTHER AREA OF
PRECIPITATION...IN THIS CASE ALL SNOW...WAS PRESENT FROM NEAR
MANKATO TO THE TWIN CITIES AS OF 05Z. THIS IS RIGHT BEHIND A COLD
FRONT. EXPECT THE BAND OF SNOW TO MOVE THROUGH THE TAF SITES
BETWEEN 09-15Z...WITH A FEW HOURS OF IFR VISIBILITIES AND PERHAPS
EVEN IFR CEILINGS OCCURRING. KLSE LOOKS TO END UP A LITTLE CLOSER
TO THE HEAVIER SNOW...THUS HAVE INCLUDED A TEMPO GROUP FOR LIFR
VISIBILITIES...IN AGREEMENT WITH WHAT WAS PRESENT AT MSP. SNOWFALL
ACCUMULATIONS LOOK LIGHT...GENERALLY AN INCH OR LESS. MAINLY VFR
VISIBILITIES...MVFR CEILINGS AND FLURRIES ARE ANTICIPATED AFTER 15
OR 16Z...AS CYCLONIC FLOW PERSISTS IN THE WAKE OF THE LOW PRESSURE
SYSTEM BRINGING THE CURRENT PRECIPITATION. SOME CONCERN THAT KRST
COULD PICK SOME ACCUMULATING SNOW LATE IN THE DAY...ASSOCIATED
WITH ANOTHER LOW PRESSURE SYSTEM DROPPING SOUTHEAST INTO IOWA.
HOWEVER...IT APPEARS THE BULK OF THE SNOW RIGHT NOW WILL STAY
SOUTH OF THE TAF SITES. NORTHWEST WINDS...WHICH COULD GUST UP TO
20 KT AT KRST...SHOULD HELP DRIVE IN DRIER AIR THURSDAY EVENING.
ANTICIPATING THIS DRIER AIR TO HELP SCATTER OUT THE CLOUDS AT
KRST. UNSURE IF THE DRIER AIR WILL GET INTO KLSE PRIOR TO
06Z...THUS HAVE HELD ONTO THE MVFR CEILING.

.ARX WATCHES/WARNINGS/ADVISORIES...
827 PM CST WED FEB 13 2013

WI...WINTER WEATHER ADVISORY UNTIL NOON CST THURSDAY FOR WIZ017-029.

MN...NONE.
IA...NONE.

SHORT TERM...AJ
LONG TERM...WETENKAMP
AVIATION...AJ

AREA FORECAST DISCUSSION

NWS CHEYENNE WY

1019 PM MST WED FEB 13 2013

.AVIATION...06Z TAFS

HAVE A COLD FRONT THAT IS FORECAST TO MOVE INTO THE PANHANDLE AND
SOUTHEAST WYOMING OVERNIGHT INTO THURSDAY MORNING. LATEST SREF AND
HRRR GUIDANCE FORECASTING A BAND OF IFR DEVELOPING OVER THE
CENTRAL PANHANDLE AROUND THE 10Z TIMEFRAME...PERSISTING THROUGH
LATE MORNING. CONFIDENCE MEDIUM IN THIS HAPPENING AS WE DO HAVE A
BAND OF SNOW IN THAT SAME GENERAL AREA RIGHT NOW. SO THIS GUIDANCE
IS SHOWING IT EXPANDING A LITTLE MORE LATER IN THE MORNING. WENT
AHEAD WITH SOME IFR CONDITIONS FOR KAIA...KSNY AND POSSIBLY KBFF.
01Z HRRR HAS THIS BAND JUST EAST OF KCYS AROUND 14Z...SO KEPT IT
OUT OF THE TAF FOR NOW. LATER SHIFT WILL NEED TO MONITOR CLOSELY.
OUT WEST FOR KRWL AND KLAR...THINK SNOW WILL DEVELOP AS THIS FRONT
MOVES THROUGH THAT AREA...BRINGING A PERIOD OF IFR CONDITIONS.
THIS WOULD BE MORE THE 12Z FORECAST CHALLENGE. BEHIND THE
FRONT...VERY STRONG NORTHWEST WINDS EXPECTED IN THE
PANHANDLE...WITH GUSTS TO 40KTS AT ALL LOCATIONS THROUGH 00Z.

CLAYCOMB

.PREV DISCUSSION... /ISSUED 606 PM MST WED FEB 13 2013/

UPDATE...

WINDS IN THE WARNED AREA...NAMELY BORDEAUX...ARLINGTON AND THE
SOUTHERN LARAMIE RANGE HAVE SHOWN STEADY DECREASES THE PAST COUPLE
HOURS. WENT AHEAD AND ALLOWED THE HIGH WIND WARNING TO EXPIRE ON
TIME AT 6 PM. GETTING SOME LIGHT SNOW BEING REPORTED IN THE
NORTHERN PANHANDLE AS WELL. RADAR IS SHOWING A BAND OF ENHANCED
SNOW SHOWERS ROUGHLY FROM ALLIANCE TO TORRINGTON TO WHEATLAND
MOVING SOUTH. WENT AHEAD AND ADDED SOME SMALL CHANCE POPS FURTHER
SOUTH THAN WHAT WE HAD PREVIOUS. UPDATES HAVE BEEN SENT.

CLAYCOMB

PREV DISCUSSION... /ISSUED 401 PM MST WED FEB 13 2013/

SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT...

STILL GETTING OCCASIONAL WIND GUSTS TO 45-50 MPH ACROSS THE WIND
PRONE AREAS THIS AFTERNOON...HOWEVER THE TREND HAS BEEN DOWNWARD
SINCE LATE MORNING. WILL KEEP THE HIGH WIND WARNING GOING THROUGH 6
PM AS THE GFS SHOWS 700MB WINDS AROUND 45 KTS THROUGH 00Z THURS
AND THE 700MB CAG-CPR GRADIENT REMAINS ABOVE 40 METERS. STILL
EXPECTING WINDS TO CONSISTENTLY DROP BELOW 50 MPH BY LATE THIS
EVENING OVER THE WIND PRONE AREAS AS THE LLVL GRADIENT DECREASES
FURTHER AND THE LLVL WINDS HAVE A MORE NORTHWESTERLY ORIENTATION.
PRETTY STRONG SHORTWAVE MOVING SOUTHWARD OVER THE NORTHERN PLAINS
OVERNIGHT WILL DRIVE A COLD FRONT ACROSS THE AREA BY THURSDAY
MORNING. FOCUS FOR THE STRONGER WINDS WILL SHIFT EASTWARD OVER THE
PANHANDLE ZONES BY THURSDAY MORNING. DECIDED TO ISSUE A WIND
ADVISORY FROM THURSDAY MORNING THROUGH THE AFTERNOON BASED ON SOME
FAVORABLE INGREDIENTS. THE GFS SHOWS NORTHWESTERLY 700MB FLOW
AROUND 50 KTS BY 18Z THURS ALONG WITH GOOD SUBSIDENCE (COLD AIR
ADVECTION) BEHIND THE SHORTWAVE. IN ADDITION...LLVL LAPSE RATES
ARE EXCELLENT BY LATE MORNING OVER THE PANHANDLE WITH 35-40 KTS OF
UNIDIRECTIONAL FLOW IN THE MIXED LAYER. SINCE SEVERAL SITES IN THE
PANHANDLE WERE CLOSE TO HITTING 45 MPH GUSTS THIS
AFTERNOON...BELIEVE THAT GUSTS TO 45-50 MPH WILL DEFINITELY BE
POSSIBLE TOMORROW.

THERE WILL BE A GOOD AMOUNT OF 700-500MB MOISTURE IN THE
NORTHWESTERLY FLOW THURSDAY MORNING THROUGH FRIDAY MORNING...WITH
THE AXIS OVER SOUTHEAST WY. THE GFS AND THE NAM SHOW WEAK MIDLEVEL
FRONTOGENESIS ACROSS EXTREME SOUTHEAST WYOMING/NEBRASKA PANHANDLE
ON THURS AFTN. HIGHEST QPF ON THURS AFTN IS GENERALLY WEST OF THE
LARAMIE RANGE (TO THE WEST OF THE FRONTOGENESIS AXIS)...SO COULD
SEE SOME ENHANCEMENT IN SNOWFALL RATES AT THAT TIME.
HOWEVER...SNOWFALL AMOUNTS ACROSS THE LOWER ELEVATIONS WILL
GENERALLY BE LESS THAN AN INCH THROUGH FRIDAY MORNING. DO HAVE
SNOWFALL AMOUNTS OF 6 TO 9 INCHES IN THE SIERRA MADRE AND SNOWY
RANGES FROM TONIGHT THROUGH FRIDAY MORNING. SINCE SNOWFALL RATES
WILL BE LIGHT WITH THIS EVENT...AND BLOWING SNOW WILL NOT BE MUCH
OF A PROBLEM OVER SOUTHEAST WY...DECIDED TO HOLD OFF ON ISSUING A
MARGINAL WINTER WEATHER ADVISORY. THIS IS ONE OF THOSE HIGHER
ACCUMULATION BUT LONG DURATION EVENTS OVER THE MTNS. WILL
CONTINUE TO HIGHLIGHT THE SNOWFALL ACCUMULATIONS IN THE MTNS IN
THE HWO AND SPS. TEMPS WILL OBVIOUSLY BE COLDER ON THURS BEHIND
THE FROPA AS 700MB TEMPS DROP DOWN TO -14C.

A FINAL SHORTWAVE DIVES DOWN INTO THE NORTHERN AND CENTRAL PLAINS
ON FRIDAY BEFORE THE LONG WAVE TROUGH QUICKLY SHIFTS EASTWARD.
THIS SHORTWAVE WILL MAINTAIN THE COLD NORTHWESTERLY FLOW OVER THE
REGION FOR ONE MORE DAY. ANOTHER SLUG OF 700-500MB MOISTURE MOVES
OVER THE AREA FROM FRIDAY MORNING INTO THE AFTN BEFORE THE
MIDLEVELS DRY OUT. A LIGHT QPF EVENT COULD BE IN STORE WITH THIS
SHORTWAVE...WITH SNOW AMOUNTS LIMITED BY WEAK DYNAMICS AND QUITE
PROGRESSIVE NATURE OF THE SYSTEM.

LONG TERM...SATURDAY THROUGH WEDNESDAY....

MILD AND MAINLY DRY WEATHER EXPECTED SATURDAY AND SUNDAY AS UPPER
RIDGE TRANSLATES ACROSS THE REGION. SOME WINDINESS WILL OCCUR
MAINLY SATURDAY AS SFC LEE TROF SETS UP OVER THE HIGH PLAINS
INCREASING THE SFC PRESSURE GRADIENT. BY LATE SUNDAY UPPER
SHORTWAVE WILL MOVE INTO THE NRN ROCKIES AND PROCEED INTO THE
NORTHERN PLAINS AND CENTRAL ROCKIES SUNDAY NIGHT INTO MONDAY.
THIS WILL PUSH NEXT COLD FRONT ACROSS THE AREA LATE SUNDAY AS WELL
AS BRING SOME SNOW OR SNOW SHOWERS. PROGRESSIVE UPPER FLOW ALLOWS
NEXT UPPER RIDGE TO PASS ACROSS MONDAY NIGHT WHILE NEXT MORE
SIGNIFICANT UPPER TROF MOVES ONSHORE ALONG THE WEST COAST. WARMER
AGAIN TUESDAY THEN EFFECTS OF THIS NEXT UPPER TROF SHOULD ARRIVE
WEDS WITH SNOW AND SNOW SHOWERS SPREADING OVER MAINLY THE WY
PORTION OF THE CWA ALONG WITH COOLER TEMPERATURES. WILL HAVE TO
WATCH THIS SYSTEM CLOSELY AS IT HAS SOME POTENTIAL TO BE
SIGNIFICANT.

FIRE WEATHER...

MINIMAL FIRE WEATHER CONCERNS THROUGH FRIDAY. TEMPERATURES WILL BE
AROUND 10-15 DEGREES BELOW NORMAL ON THURSDAY AND FRIDAY. MINIMUM
AFTERNOON HUMIDITIES WILL GENERALLY BE ABOVE 40 PERCENT. THERE
WILL BE ISOLATED TO WIDELY SCATTERED SNOW SHOWERS THURSDAY MORNING
THROUGH FRIDAY MORNING OVER THE PLAINS...HOWEVER ACCUMULATIONS ARE
EXPECTED TO BE LESS THAN AN INCH.

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...WIND ADVISORY FROM 8 AM THURSDAY TO 4 PM THURSDAY FOR NEZ002-
NEZ003-NEZ019-NEZ020-NEZ021-NEZ054-NEZ055-NEZ095-NEZ096.

SHORT TERM/FIRE WEATHER...FINCH
LONG TERM/AVIATION...RE

AREA FORECAST DISCUSSION

NWS MIAMI FL

815 AM EST THU FEB 14 2013

...ISOLATED TSTORMS, SOME COULD CONTAIN STRONG WIND GUSTS AND
LOCALLY HEAVY RAINFALL...

.UPDATE...WAVES OF HEAVY SHOWERS CONTINUE TO MOVE NE ACROSS
COLLIER TO PALM BEACH COUNTIES. ONLY ONE LIGHTNING STRIKE NOTED
JUST OFF THE COLLIER COAST A COUPLE OF HOURS AGO. GIVEN RADAR AND
EXPECTED TRENDS, HAVE INCREASED POPS ACROSS THE AREA. HRRR SHOWS A
GENERAL DECREASING TREND LATER THIS MORNING BEFORE THINGS REV BACK
UP AGAIN THIS AFTERNOON...AND WITH SLIGHTLY BETTER HEATING ACROSS
BROWARD AND MIAMI-DADE COUNTIES, TSTORMS COULD ERUPT ABOUT
ANYWHERE BUT BETTER CHANCES THERE. MORNING ANALYSIS INDICATES THE
POTENTIAL FOR A FEW STRONG TSTORMS WITH GUSTY WINDS TO AROUND 50
MPH. THERE IS SOME INCREASING INSTABILITY ALONG WITH AN INCOMING
SHORTWAVE OVER THE GULF OF MEXICO WHICH COULD IGNITE A FEW STRONG
TSTORMS, PARTICULARLY THIS AFTERNOON INTO EARLY THIS EVENING.

TEMPS WERE LOWERED A BIT ACROSS SE AREAS SINCE CLOUDS ARE
INCREASING FROM THE WEST. THEREFORE, MAX TEMPS IN THE LOWER 80S
ARE NOW FORECAST WITH MID-UPPER 70S LAKE OKEECHOBEE REGION.

/GREGORIA

.PREV DISCUSSION... /ISSUED 621 AM EST THU FEB 14 2013/

AVIATION...
COLD FRONT CURRENTLY NEAR A FORT LAUDERDALE TO EVERGLADES CITY
LINE AND CLEARLY DEFINED BY BROKEN LINE OF SHRA BEHIND THE BOUNDARY.
THE FRONT IS EXPECTED TO STALL ACROSS SOUTH FLORIDA BUT MODEL
GUIDANCE DIFFERS JUST WHERE THE BOUNDARY BECOMES STATIONARY AND
THIS WILL LIKELY PLAY HAVOC WITH THE WIND DIRECTION. AT ANY RATE,
INCREASED CLOUD COVER WILL OCCUR WITH CHANCES OF RAIN ALSO
INCREASING AT ALL TERMINALS THROUGH THE FORECAST WITH OCCASIONAL
MVFR CIG/VSBY AND BRIEF IFR CANNOT BE RULED OUT EITHER.

KOB

PREV DISCUSSION... /ISSUED 333 AM EST THU FEB 14 2013/

SHORT TERM...
A COLD FRONT WILL CONTINUE TO SLOWLY MOVE INTO SOUTH FLORIDA AS
TODAY PROGRESSES. MOISTURE ADVECTION WILL TAKE PLACE THROUGHOUT THE
DAY LEADING TO AN INCREASED CHANCE OF RAIN. SINCE THIS FRONT WILL
STALL OUT, IT LOOKS LIKE IT WILL BE A CLOUDY AND WET 48 HOUR
PERIOD WITH SOME STEADY RAIN ALONG THE FRONT AS WELL AS THE
POTENTIAL FOR SOME HEAVIER SHOWERS AND A FEW THUNDERSTORMS.
INSTABILITY WILL BE RATHER LOW THROUGHOUT THE PERIOD WHICH WILL
LIMIT THE THUNDERSTORM ACTIVITY, HOWEVER SOME EMBEDDED
THUNDERSTORMS COULD DEVELOP. THE MAIN CONCERN WITH THIS FRONT WILL
BE THE POTENTIAL FOR HEAVY RAIN. MODEL CONCENSUS IS SHOWING A
WIDESPREAD AREA OF 1 TO 2 INCHES OF RAIN TODAY INTO FRIDAY. SOME
AREAS COULD SEE LOCALIZED HIGHER TOTALS IN EXCESS OF 3 INCHES
WHERE THE HEAVIER SHOWERS OR THUNDERSTORMS SET UP. THIS COULD RESULT
IN ISOLATED URBAN FLOODING. HOWEVER, WIDESPREAD FLOOD PROBLEMS ARE
NOT EXPECTED DUE TO THE DRY SPELL WE HAVE BEEN IN.

LONG TERM...
A STRONGER FRONT WILL BEGIN TO HELP MOVE ALL OF THE SHOWER AND
THUNDERSTORM ACTIVITY OUT OF THE REGION BY FRIDAY NIGHT INTO EARLY
SATURDAY MORNING. BEHIND THIS FRONT A STRONG AREA OF HIGH
PRESSURE WILL BUILD IN FROM THE NORTH BRINGING IN MUCH COLDER
TEMPERATURES TO THE REGION. THE STRONGEST PUSH OF COLD AIR WILL
MOVE INTO THE REGION SATURDAY NIGHT AND SUNDAY. THE EXACT TIMING
OF THIS IS STILL UNCERTAIN AS THE GFS IS SLIGHTLY SLOWER AND A
LITTLE BIT WARMER ON SATURDAY NIGHT INTO SUNDAY, HOWEVER IT HAS
BEEN TRENDING TOWARDS THE QUICKER AND COLDER ECMWF SOLUTION. THE
FORECAST IS TRENDED TOWARDS THE ECMWF WHICH WOULD DROP TEMPERATURES
INTO THE MID 30S IN GLADES AND HENDRY COUNTIES ON BOTH SUNDAY AND
MONDAY MORNING. THERE COULD BE ISOLATED POCKETS OF TEMPERATURES
DROPPING TO NEAR FREEZING IN THE COLDER LOCATIONS. WE WILL
CONTINUE TO MONITOR THESE TRENDS. TEMPERATURES ON SUNDAY MORNING
ACROSS THE SOUTHEASTERN METRO AREAS WILL BE IN THE MID TO UPPER
40S. COLD AIR ADVECTION WILL CONTINUE DURING THE DAY ON SUNDAY AS
MANY AREAS WILL REMAIN IN THE MID TO UPPER 60S FOR DAYTIME HIGHS.
THIS AREA OF HIGH PRESSURE WILL MOVE EAST OF THE AREA EARLY NEXT
WEEK RESULTING MODERATING TEMPERATURES BY MONDAY AFTERNOON INTO
TUESDAY WITH DRY CONDITIONS.

MARINE...
A COLD FRONT WILL STALL OUT OVER THE ATLANTIC AND GULF WATERS
TODAY. THIS FRONT WILL REMAIN IN PLACE THROUGH FRIDAY CREATING A
CHANCE OF SHOWERS AND A FEW THUNDERSTORMS. WINDS WILL REMAIN OUT
OF THE SOUTH AT 10 TO 15 KNOTS THIS AFTERNOON. THE FRONT WILL MOVE
TO THE SOUTH OF THE REGION ON FRIDAY NIGHT INTO SATURDAY. GUSTY
NORTHWEST WINDS BEHIND THE FRONT MAY CREATE HAZARDOUS MARINE
CONDITIONS THIS WEEKEND.

FIRE WEATHER...
MINIMUM RELATIVE HUMIDITY VALUES WILL REMAIN ABOVE CRITICAL VALUES
ON THURSDAY NIGHT INTO FRIDAY. THESE VALUES ARE EXPECTED BE MUCH
LOWER BEHIND THE FRONT ON SUNDAY AND MONDAY AFTERNOON.

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 79 63 76 60 / 80 70 50 40
FORT LAUDERDALE 83 67 77 62 / 70 70 50 50
MIAMI 83 66 80 63 / 70 70 50 50
NAPLES 79 61 75 58 / 90 70 50 30

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&

AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

1044 AM EST THU FEB 14 2013

.SYNOPSIS...
FAST MOVING LOW PRESSURE WILL MOVE ACROSS THE GREAT LAKES TODAY
BRINGING A CHANCE OF RAIN SHOWERS EARLY AND SNOW SHOWERS OVERNIGHT
AS A WEAK FRONT CROSSES. COLDER AIR BEHIND THE FRONT WILL PROVIDE
THE RISK FOR SNOW SHOWERS INTO THE WEEKEND.

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NOT MUCH MORE THAN FEW FLURRIES ARE BEING OBSERVED THIS
MORNING OUT AHEAD OF THE LOW PRESSURE SYSTEM CURRENTLY ANALYZED
OVER MICHIGAN. THE RUC SEEMS TO BE PICKING UP ON THESE FLURRIES
WITH MID LEVEL CLOUD DECK RIGHT AROUND THE LOWER END OF THE
DENDRITIC GROWTH ZONE HELPING TO SEED THE LOWER LEVEL STRATUS. THIS
SHOULD END SHORTLY AS WARM ADVECTION AND MIXING OUT AHEAD OF THE
LOW HELPS TO WARM TEMPERATURES ABOVE FREEZING. WITH MID-DECK
REMAINING IN PLACE HOWEVER...DIDN`T GO OVER ZEALOUS WITH THE
WARMING TODAY AND TEMPERATURES WERE KEPT CLOSE TO MET GUIDANCE.

WITH VERY LITTLE MOISTURE FOR THIS CLIPPER-LOW TO WORK WITH AS IS
APPARENT IN BOTH SATELLITE DATA AND THE MODEL RUNS...MAINTAINED
HIGHER CHANCE POPS FOR MUCH OF THE NORTHERN HALF OF THE REGION
TODAY...CLOSER TO THE LOW CENTER WHERE BETTER LIFT IS PRESENT.
PRECIPITATION SHOULD MAINLY START OUT AS RAIN THROUGH EARLY THIS
EVENING AHEAD OF THE LAGGING COLD FRONT THAT SHOULD CROSS
OVERNIGHT.

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
WEAK COLD ADVECTION RETURNS THURSDAY NIGHT INTO FRIDAY AS A STRONG
COLD FRONT PUSHES ACROSS THE REGION. TEMPERATURES WILL FALL WELL
BELOW NORMAL BY FRIDAY NIGHT AND CONTINUE QUITE COLD INTO
SATURDAY AS 850MB TEMPS FALL TO -18C. EXPECT SCATTERED SNOW
SHOWERS THROUGH THE PERIOD.

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
PROGRESSIVE PTN IS INDICATED THROUGH THE LONG TERM PD WITH SHSN
DIMINISHING SATURDAY NGT INTO SUNDAY. WARM ADVCTN REGIME IS
EXPECTED TO MODERATE TEMPS BACK TOWARD THE AVERAGES AND ABOVE BY
MONDAY AS THE NXT UPR LVL TROF DVLPS EWD. THAT SYSTEMS CDFNT IS
PROJECTED ACRS THE REGION BY TUESDAY NGT.

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
ALTHOUGH HIGH PRESSURE RIDGE IS MOVING INTO THE REGION...MVFR
STRATUS REMAINS DRAPED FROM PITTSBURGH TO THE SOUTH. LOW LEVEL
MOISTURE APPEARS TO BE TRAPPED AT THE SURFACE. EXPECT THAT MVFR
CONDITIONS WILL CONTINUE AT MOST SITES...WITH MOST LOCATIONS KEEPING
THE STRATUS DECK...WITH FOG REDEVELOPING IN LOCATIONS AS STRATUS
SLOWLY MOVES TO THE EAST OVERNIGHT.

EXPECT STRATOCUMULUS TO DEVELOP ACROSS THE AREA THURSDAY. HAVE STUCK
WITH VFR CIGS IN TAFS FOR NOW...ALTHOUGH MODEL PROFILES SHOW THAT
CIGS MAY ACTUALLY DEVELOP AS HIGH MVFR INSTEAD. MOST LOCATIONS
SHOULD HAVE S-SW GUSTS TO 15-20 KTS DURING THE AFTERNOON HOURS.
STILL DO NOT HAVE ENOUGH CONFIDENCE IN PRECIPITATION CHANCES AT
FKL/DUJ TO INCLUDE IN TAFS AT THIS TIME...ALTHOUGH THIS EVENING
WOULD HAVE THE GREATEST LIKELIHOOD FOR SNOW SHOWERS.

.OUTLOOK.../FRIDAY THROUGH MONDAY/...
PERIODIC RESTRICTIONS ARE PSBL THRU SUN AS SVRL FAST MOVG
DISTURBANCES MOVE THRU THE GT LKS RGN. HI PRES AND VFR CONDS RETURN
MON.

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

AREA FORECAST DISCUSSION

NWS MARQUETTE MI

951 AM EST THU FEB 14 2013

.UPDATE...
ISSUED AT 947 AM EST THU FEB 14 2013

NO CHANGES PLANNED TO THE ONGOING HEADLINES THIS MORNING. SNOWFALL
REPORTS ACROSS NORTHEAST WI AND SOUTHERN MENOMINEE COUNTY HAVE BEEN
AROUND 3 INCHES. WITH MODERATE SNOW EXPECTED TO CONTINUE FOR
ANOTHER FEW HOURS...THE GOING 3 TO 5 INCH FORECAST LOOKS ON TRACK.
THE ONE LOCATION WHERE AMOUNTS MAY END UP A LITTLE HIGHER THAT
PREVIOUSLY FORECAST IS ACROSS SOUTHERN DELTA AND SCHOOLCRAFT
COUNTIES...MAINLY OVER THE GARDEN AND STONINGTON PENINSULAS...WHERE
THE SNOW RATIOS HAVE BEEN A LITTLE HIGHER THAN FARTHER SOUTH.
REPORTS OF 1.5 TO 2 INCHES HAVE BEEN COMMON ALONG LAKE MI. WITH
ANOTHER INCH OR SO POSSIBLE WITH A HEAVIER BAND OF SNOW FOCUSED
UNDER 900 TO 850MB FRONTOGENESIS. WILL ISSUE A SPECIAL WX STATEMENT
FOR THOSE LOCATIONS FOR LOCAL SNOW AMOUNTS UP TO 3 INCHES.
&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 448 AM EST THU FEB 14 2013

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 448 AM EST THU FEB 14 2013

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 639 AM EST THU FEB 14 2013

A LOW PRESSURE SYSTEM EXITING CENTRAL WISCONSIN THIS MORNING WILL
PRODUCE LIGHT SNOW SHOWERS AT KSAW FOR THE FIRST COUPLE OF HOURS
OF THE FORECAST. FOCUS THEN TURNS TO LAKE ENHANCED SNOW FOR A
PERIOD TODAY...A BRIEF LULL DURING LATE AFTERNOON AND EARLY
EVENING BEFORE LAKE EFFECT ARRIVES FOR NORTH-NORTHWEST WIND
LOCATIONS.

WILL CONTINUE IDEA OF LOWER VISIBILITIES AND CEILINGS WITH LAKE
ENHANCED SNOW THROUGH THIS AFTERNOON AT ALL SITES. BUT AS THE LOW
QUICKLY DEPARTS THIS AFTERNOON...SUPPORTING DEEP MOISTURE DEPARTS
AND EXPECT WEAKENING SNOW SHOWERS INTO THE EVENING. BUT WITH COLDER
AIR INCREASING THROUGH THE NIGHT...SHOULD SEE LAKE EFFECT SNOW
INTENSIFY AT KIWD/KCMX THROUGH THE NIGHT. KSAW ON THE OTHER HAND
WON/T SEE TOO FAVORABLE WIND DIRECTIONS AND HAVE JUST WENT WITH
MVFR CEILINGS.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EST THU FEB 14 2013

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM FRIDAY MORNING THROUGH SATURDAY
AFTERNOON FOR MIZ006-085.

WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MIZ012.

LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 AM EST
SATURDAY FOR LSZ264>266.

LAKE MICHIGAN...
NONE.
&&

UPDATE...TK
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...SRF

AREA FORECAST DISCUSSION

NWS MARQUETTE MI

640 AM EST THU FEB 14 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 448 AM EST THU FEB 14 2013

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 448 AM EST THU FEB 14 2013

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 639 AM EST THU FEB 14 2013

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EST THU FEB 14 2013

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM FRIDAY MORNING THROUGH SATURDAY
AFTERNOON FOR MIZ006-085.

WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MIZ012.

LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 AM EST
SATURDAY FOR LSZ264>266.

LAKE MICHIGAN...
NONE.
&&

SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...SRF

AREA FORECAST DISCUSSION...UPDATED

NWS NORTH PLATTE NE

633 AM CST THU FEB 14 2013

.UPDATE...

.DISCUSSION...
NO MAJOR CHANGES TO THIS UPDATE. 06Z NAM IS A BIT DRIER WITH QPF
AMOUNTS. SHSN CONVERAGE IS ABOUT THE SAME. LESS THAN AN INCH OF
SNOW IS EXPECTED.

.PREV DISCUSSION... /ISSUED 529 AM CST THU FEB 14 2013/

UPDATE...

AVIATION...
SCATTERED MVFR WILL SPREAD INTO NRN NEB THIS AFTN WITH THE
PASSAGE OF AN ARCTIC FRONT CURRENTLY AT 11Z NEAR KSDY. SCATTERED
SNOW SHOWERS AND MVFR WILL ACCOMPANY THE FRONT. MVFR AND ISOLATED SNOW
SHOWERS MAY PERSIST TONIGHT ACROSS THE NORTH. ELSEWHERE MOSTLY VFR
IS EXPECTED WITH ISOLATED RAIN OR SNOW SHOWERS DURING THE DAY
TODAY. WINDS WILL INCREASE THIS AFTERNOON TO 32025G40KT AND
DECREASE AT SUNSET.

PREV DISCUSSION... /ISSUED 328 AM CST THU FEB 14 2013/

DISCUSSION...

NEAR TERM...TODAY AND TONIGHT.

SHORT TERM...12Z FRIDAY THROUGH 12Z SUNDAY.

LONG TERM...12Z SUNDAY AND BEYOND.

AVIATION...

.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY FROM 10 AM CST /9 AM MST/ THIS MORNING TO 6 PM CST
/5 PM MST/ THIS EVENING FOR NEZ004>010-022>029-035>038-056>059-
069>071-094.

SHORT TERM...CDC
LONG TERM...CDC
AVIATION....CDC

AREA FORECAST DISCUSSION

NWS HASTINGS NE

540 AM CST THU FEB 14 2013

.AVIATION...12Z KGRI TAF. WIND WILL INCREASE SPEED FOR THIS
MORNING WITH INCREASING HEIGHT RISES BEHIND A COLD FRONT. CEILINGS
COULD BE A BIT TRICKY...YET PROBABLY MAINLY IN THE MID-RANGE FOR
HEIGHT. COULD BE SOME SPRINKLE/FLURRY ACTIVITY...BUT AIR IN LOWER
LEVELS IS QUITE DRY...SO THIS WILL NOT AMOUNT TO A WHOLE
LOT...PERHAPS GIVING A QUICK BIT OF A BURST OF WIND. MODELS
INDICATE THAT THERE COULD BE AT LEAST SOME SCATTERED STRATUS
STICKING AROUND FOR THIS EVENING WITH DECREASING WIND BUT
CONTINUING POSSIBILITY OF FLURRIES...NOT INCLUDED IN THE FORECAST
AS CONFIDENCE IS NOT HIGH FOR THIS OCCURRENCE.

.PREV DISCUSSION... /ISSUED 529 AM CST THU FEB 14 2013/

SHORT TERM...ALTHOUGH NO TRULY HIGH-IMPACT WEATHER IS EXPECTED
DURING THE NEXT 72 HOURS...THINGS START OFF WITH A SOMEWHAT MARGINAL
WIND ADVISORY EVENT TODAY...FOLLOWED BY PESKY HARD-TO-PIN-DOWN
FLURRY/BRIEF SNOW SHOWER CHANCES FROM THIS AFTERNOON THROUGH
FRIDAY EVENING. ALTHOUGH THE VAST MAJORITY OF THE CWA IS UNLIKELY
TO SEE ACCUMULATING SNOW...A LIGHT DUSTING HERE OR THERE IS NOT
OUT OF THE QUESTION ESPECIALLY FRIDAY AFTERNOON/EVENING.

10Z OBJECTIVE CENTRAL PLAINS SURFACE ANALYSIS REVEALS A SUBTLE
SURFACE TROUGH FROM EASTERN-SOUTHERN KANSAS...TRAILING SOUTHWEST
FROM A 1001MB LOW IN WISCONSIN. A BROAD WEST-NORTHWEST SURFACE
WIND REGIME WAS FIRMLY IN PLACE ACROSS THE CWA...WITH SUSTAINED
SPEEDS GENERALLY 5-15 MPH. THESE STEADY BREEZES ARE RESULTING IN
AT LEAST A SLIGHTLY-WARMER-THAN-EXPECTED NIGHT...WITH OVERNIGHT
LOWS IN MOST AREAS LIKELY BOTTOMING OUT BETWEEN 27-31 DEGREES. TO
THE NORTH...A SOMEWHAT ILL-DEFINED EAST-WEST COLD FRONT IS ALIGNED
ACROSS SOUTH DAKOTA...WITH THIS BOUNDARY EXPECTED TO VERY SLOWLY
BLEED SOUTHWARD ACROSS THE LOCAL AREA AS THE DAY WEARS ON.
ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA IS
HIGHLIGHTED BY INCREASINGLY ACTIVE NORTHWEST FLOW...AS JUST IN THE
PAST 12 HOURS A PAIR OF LOW AMPLITUDE CLIPPER SHORTWAVE TROUGHS
HAVE TRACKED ALONG A CORRIDOR FROM THE DAKOTAS TOWARD IA. 11-3.9
MICRON SATELLITE IMAGERY SHOWS RELATIVELY CLEAR SKIES STEADILY
GIVING WAY TO INCREASING HIGH CLOUD COVER FROM THE WEST.
MEANWHILE...A SMALL BATCH OF MID LEVEL CLOUDS THAT BROUGHT SOME
RATHER UNEXPECTED BRIEF SPRINKLES TO PARTS OF THE CWA LAST EVENING
HAS MOVED WELL OFF TO THE SOUTHEAST.

TODAY...THE MAIN FOCUS CONTINUES TO BE ON INCREASING NORTHWEST
WINDS...ALTHOUGH WILL STATE UP FRONT THAT THE INTENSITY/DURATION
OF THE STRONGEST WINDS HAS NOW TRENDED DOWNWARD A BIT OVER THE
PAST FEW MODEL RUNS...SO THIS WILL LIKELY BE A SOMEWHAT MARGINAL
WIND ADVISORY EVENT. WINDS WILL NOT START THE DAY ALL THAT
STRONG...AS IT WILL BE AT LEAST LATE MORNING/EARLY AFTERNOON
BEFORE INCREASING PRESSURE RISES AND DEEPENING MIXING BEHIND THE
INITIAL PASSING COLD FRONT RAMPS SPEEDS UP. ALOFT...THIS
INCREASING SURGE OF NORTHWEST WINDS WILL BE DRIVEN BY LOW
AMPLITUDE SHORTWAVE TROUGH DROPPING SOUTH OF SD INTO NEB/IA. HAVE
MADE NO CHANGES WHATSOEVER TO THE WIND ADVISORY ITSELF...STARTING
AT 11 AM AND ENDING AT 6 PM...WITH THE OVERALL BEST TIME FRAME FOR
SUSTAINED SPEEDS NEARING/MEETING 30 MPH WITH GUSTS 40 TO POSSIBLY
45 MPH CENTERED DURING THE MID-AFTERNOON. FARTHER SOUTH IN OUR KS
ZONES...AM GENERALLY EXPECTING SUSTAINED SPEEDS TO TOP OUT CLOSE
TO 25 MPH...THUS FALLING ABOUT 5 MPH SHORT OF ADVISORY CRITERIA SO
NOT ANTICIPATING ANY SOUTHWARD EXPANSION AT THIS TIME. HOURLY TEMP
TRENDS WILL BE TRICKY TODAY WITH A FAIRLY RAPID INITIAL RISE THEN
FOLLOWED BY A SLOW-BUT-STEADY FALL AS THE AFTERNOON WEARS ON AND
COLD AIR ADVECTION TAKES HOLD. HAVE FOLLOWED THE 06Z RAP SOLUTION
FAIRLY CLOSELY...WHICH ACTUALLY RESULTED IN ABOUT A 4 DEGREE
UPWARD BUMP TO HIGHS WITH MOST OF SOUTH CENTRAL NEBRASKA NOW
EXPECTED TO AT LEAST BRIEFLY TOUCH THE MID IF NOT UPPER 40S EXCEPT
COOLER FAR NORTH...AND KS ZONES RIGHT AROUND 50. THE ONLY CAVEAT HERE
IS WHETHER INCOMING MID/HIGH CLOUDS ARE THICK ENOUGH TO TEMPER
THINGS A BIT. PRECIPITATION WISE...KEPT ALL MENTION OUT OF THE
MORNING HOURS...BEFORE BRINGING IN NON-MEASURABLE CHANCES FOR
FLURRIES AND/OR SPRINKLES DURING THE AFTERNOON IN RESPONSE TO THE
INCOMING MID LEVEL SHORTWAVE TROUGH AND INCREASING UPPER JET
DYNAMICS. RAW MODEL QPF FIELDS CONTINUE TO BE ALL OVER THE
PLACE...AND ALTHOUGH THE MAJORITY OF THE CWA MAY NOT SEE A SINGLE
RAIN DROP OR SNOWFLAKE BEFORE SUNSET...IT SEEMS THE MOST FAVORED AREAS
WOULD BE NORTH OF NEBRASKA HWY 92 AND ALSO WITHIN THE SOUTHWEST
1/4 OF THE CWA.

THIS EVENING/TONIGHT...ALTHOUGH IT WILL REMAIN QUITE BREEZY EARLY
ON THIS EVENING...HAVE FAIRLY HIGH CONFIDENCE THAT THE WIND SPEEDS
WILL SAFELY FALL BELOW ADVISORY CRITERIA BY THE CURRENT EXPIRATION
TIME OF 6 PM...WITH SUSTAINED SPEEDS THEN STEADILY TRENDING DOWN
THROUGH THE REMAINDER OF THE NIGHT AS SURFACE HIGH PRESSURE SETTLES
IN FROM THE NORTHWEST. IN FACT AFTER MIDNIGHT...ONLY LOOKING AT SPEEDS
AROUND 10 MPH MOST AREAS. ALTHOUGH THE VAST MAJORITY OF THE CWA
WILL LIKELY REMAIN PRECIP-FREE TONIGHT...ITS OFTEN SEEN IN THIS
TYPE OF NORTHWEST FLOW PATTERN THAT EVEN SMALL BANDS/PATCHES OF
MID LEVEL CLOUDS COULD PRODUCE SOME SPORADIC FLURRIES...SO WILL
CONTINUE TO KEEP IT SIMPLE AND BLANKET THE ENTIRE CWA WITH THIS
SLIGHT FLURRY CHANCE. NUDGED DOWN LOW TEMPS GENERALLY 1-2 DEGREES
FROM PREVIOUS GRIDS...WITH MOST AREAS BOTTOMING OUT 15-19 DEGREES
ASSUMING THAT A CLOUD BAND DOESN/T PARK ITSELF SOMEWHERE AND HOLD
THINGS UP A BIT HIGHER.

FRIDAY INTO FRIDAY EVENING WILL HOLD THE BEST POTENTIAL FOR
A MORE WIDESPREAD COVERAGE OF FLURRIES AND POSSIBLY VERY LIGHT
SNOW ACCUMULATIONS IN A FEW AREAS...AS THE FINAL AND LIKELY MOST
VIGOROUS NORTHWEST-FLOW SHORTWAVE TROUGH DROPS SOUTHWARD ACROSS
THE HEART OF THE LOCAL AREA...FOCUSED WITHIN THE EXIT REGION OF A
RATHER STOUT MERIDIONAL UPPER JET OF 120+ KNOTS. ALTHOUGH WILL
KEEP AN OUTSIDE CHANCE OF A FLURRY GOING ON FRIDAY MORNING...HAVE
ADDED A SLIGHT CHANCE MEASURABLE POP TO THE AFTERNOON/EVENING
HOURS AS THE MAIN SHORTWAVE AXIS PASSES OVER. THIS IS LOOKING LIKE
A FAIRLY CLASSIC SETUP FOR QUICK NORTH-TO-SOUTH MOVING BRIEF SNOW
SHOWERS...GIVEN STEEP LOW LEVEL LAPSE RATES AND DEEP MIXING. THIS
SCENARIO IS WELL CAPTURED IN THE REFLECTIVITY PROG OF THE 00Z 4KM
WRF-NMM...WITH HIT AND MISS SNOW SHOWERS BLOSSOMING ACROSS THE
AREA DURING THE DAY BEFORE WEAKENING AND EVENTUALLY MOVING OUT
ALTOGETHER BY MIDNIGHT AS THE BACK EDGE OF THE MID LEVEL TROUGH
AXIS PASSES. THIS WILL BE A SITUATION WHERE SOME AREAS SEE A LIGHT
DUSTING OF SNOW...WHILE OTHERS MISS OUT COMPLETELY...AND AS THESE
MESOSCALE DETAILS BECOME CLEARER ITS POSSIBLE THAT POPS MIGHT BE
RAISED ABOVE THE CURRENT 20 PERCENT IN SOME AREAS. ALTHOUGH
AFTERNOON/EVENING WIND SPEEDS WILL NOT BE AS STRONG AS TODAY...AT
LEAST A FEW HOURS OF SUSTAINED 15-20 MPH SPEEDS IS
EXPECTED...WHICH COULD POSSIBLY RESULT IN LOCALIZED/BRIEF
VISIBILITY RESTRICTIONS UNDER PASSING SNOW SHOWERS...BUT NOT A
WIDESPREAD HAZARD WORTHY OF MENTION IN THE HWO AT THIS TIME.
TEMP-WISE...MADE A VERY SMALL UPWARD NUDGE TO PREVIOUS HIGHS BUT
THIS WILL STILL BE THE COLDEST DAY OF THE WEEK WITH HIGHS IN THE
30S MOST AREAS AND MAYBE ONLY UPPER 20S FAR NORTH. LIGHT WESTERLY
BREEZES LATE FRIDAY NIGHT SHOULD KEEP LOWS FROM TANKING TOO
FAR...BUT STILL DROPPING DOWN BETWEEN 14-18 MOST AREAS.

SATURDAY INTO SATURDAY NIGHT...HAVE RATHER HIGH CONFIDENCE IN A
DRY PERIOD WITH WARMING TEMPERATURES...AS THE BIG PICTURE ALOFT
INVOLVES AN INVADING SHORTWAVE RIDGE IN THE WAKE OF A DEEP
LONGWAVE TROUGH EXITING EASTWARD ACROSS THE EASTERN CONUS. IN THE
LOW LEVELS...WEST-SOUTHWEST BREEZES GENERALLY 10-15 MPH WILL
BRING IN SOME PRETTY STOUT WARM AIR ADVECTION DURING THE
DAY...ALTHOUGH THIS MAY BE TEMPERED SOMEWHAT BY WHAT COULD BE A
FAIRLY SOLID PASSING DECK OF MID CLOUDS. NO MATTER WHAT THOUGH...A
NOTABLE WARM-UP OVER FRIDAY IS IN STORE...AND BASED ON A BLEND OF
THE 00Z NAM/ECMWF RAISED 3-4 DEGREES FROM PREVIOUS FORECAST
ESPECIALLY ACROSS WESTERN COUNTIES...NOW CALLING FOR A RANGE FROM
LOW 40S EAST TO NEAR 50 WEST. SUPPOSE A FEW SPRINKLES FALLING OUT
OF THE AFOREMENTIONED MID DECK IS NOT OUT OF THE QUESTION...BUT
SEEMS UNLIKELY ENOUGH FOR NOW TO OMIT ANY GRID MENTION. SATURDAY
NIGHT...LIGHT WESTERLY BREEZES SHOULD KEEP LOW TEMPS SEVERAL
DEGREES WARMER THAN THE PREVIOUS FEW NIGHTS...AND MADE LITTLE
CHANGE WITH MID 20S MOST AREAS.

LONG TERM...SUNDAY THROUGH WEDNESDAY.

THE LONG TERM WILL CONSIST OF A SERIES OF PROGRESSIVE SHORTWAVE
TROUGHS AND RIDGES OF PACIFIC ORIGIN.

TOOK MORE OF A CONSENSUS APPROACH FOR THE LONG TERM...FAVORING
ENSEMBLE MEANS.

SUNDAY APPEARS THAT IT WILL BE THE MOST MILD DAY AS 850 MB
TEMPERATURES WARM UP NICELY IN ASSOCIATION WITH A PASSING SHORTWAVE
RIDGE. THERE WILL BE INCREASED WARMING JUST AHEAD OF AN APPROACHING
COLD FRONT...WITH SURFACE SOUTHWEST WIND DECREASING AS THE FRONT
APPROACHES...CONDITIONS COULD BECOME DOWNRIGHT SPRING-LIKE FOR THE
AFTERNOON.

COLDER AIR SPILLS IN FOR MONDAY...AND INCREASED WIND SPEEDS FROM THE
NORTH QUITE A BIT FROM ALLBLEND/CONSALL AS A RESULT OF THE HEALTHY
COLD AIR ADVECTION. THE COOL SURFACE HIGH FINALLY MAKES ITS WAY INTO
OUR AREA BY TUESDAY...WHICH SHOULD BE JUST ABOUT THE COOLEST HIGH
FOR THE LONG TERM BEFORE A BIT OF A REBOUND OCCURS FOR WEDNESDAY.
THIS REBOUND OCCURS AHEAD OF A DIGGING MEAN LONG TROUGH OVER THE
ROCKY MOUNTAINS WHICH WILL BE MOVING EAST.

.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM 11 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR NEZ039>041-046>049-060>064-072>077-082>087.

KS...NONE.
&&

SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...HEINLEIN

AREA FORECAST DISCUSSION...UPDATED

NWS NORTH PLATTE NE

529 AM CST THU FEB 14 2013

.UPDATE...

.AVIATION...
SCATTERED MVFR WILL SPREAD INTO NRN NEB THIS AFTN WITH THE
PASSAGE OF AN ARCTIC FRONT CURRENTLY AT 11Z NEAR KSDY. SCATTERED
SNOW SHOWERS AND MVFR WILL ACCOMPANY THE FRONT. MVFR AND ISOLATED SNOW
SHOWERS MAY PERSIST TONIGHT ACROSS THE NORTH. ELSEWHERE MOSTLY VFR
IS EXPECTED WITH ISOLATED RAIN OR SNOW SHOWERS DURING THE DAY
TODAY. WINDS WILL INCREASE THIS AFTERNOON TO 32025G40KT AND
DECREASE AT SUNSET.

.PREV DISCUSSION... /ISSUED 328 AM CST THU FEB 14 2013/

DISCUSSION...

NEAR TERM...TODAY AND TONIGHT.

SHORT TERM...12Z FRIDAY THROUGH 12Z SUNDAY.

LONG TERM...12Z SUNDAY AND BEYOND.

AVIATION...

.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY FROM 10 AM CST
/9 AM MST/ THIS MORNING TO 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ004>010-022>029-035>038-056>059- 069>071-094.

SHORT TERM...CDC
LONG TERM...CDC
AVIATION....CDC

AREA FORECAST DISCUSSION

NWS PUEBLO CO

308 PM MST THU FEB 14 2013

.SHORT TERM...(TONIGHT AND TOMORROW)
ISSUED AT 308 PM MST THU FEB 14 2013

A FAST MOVING COLD FRONT HAS MOVED SOUTH OF HIGHWAY 50. THE FRONT
SHOULD CLEAR THE CO/NM BORDER BY 22Z. THE HRRR AND RAP PROG ANY
LINGERING SNOW SHOWERS TO END BY MIDNIGHT ACROSS THE AREA.
HOWEVER...THE NAM12 AND GFS ARE HOLDING ON TO SNOW SHOWERS
THROUGH 12Z ACROSS THE SOUTHERN I-25 CORRIDOR. DECIDED TO LEAVE
SOME 15 TO 35 POPS SOUTH AND WEST OF TAD IN THE GRIDS. DUE TO TO
THE FAST MOVEMENT OF THE FRONT/PRECIP...LITTLE TO NO ACCUMULATIONS
ARE EXPECTED UNDER ANY OF THE SNOW SHOWERS EAST OF THE CONTINENTAL
DIVIDE. GUSTY NORTHEAST WINDS WILL BEGIN TO RELAX AFTER 02Z. WEST
OF THE I-25 CORRIDOR...LIGHT SNOW SHOWERS WILL CONTINUE IN AND
AROUND THE LEADVILLE AREA OVERNIGHT INTO TOMORROW MORNING. THE
SAN LUIS VALLEY WILL BE MOSTLY CLEAR...COLD...AND DRY OVERNIGHT

FRIDAY...MODELS CONTINUE TO SHOW LIGHT SNOW SHOWERS IN THE LEADVILLE
AREA THROUGH FRIDAY AFTERNOON AND HAVE KEPT POPS IN PLACE AS PREVIOUSLY
FORECASTED. 700MB TEMPERATURES WILL FALLING TO -11 TO -13.5C WILL
KEEP HIGH TEMPERATURES 3-5 DEGREES COOLER ACROSS MOST LOCATIONS
FRIDAY AFTERNOON. A FEW LINGERING CLOUDS ACROSS THE AREA WILL ALSO
HELP TO CAP HIGH TEMPERATURES TOMORROW AFTERNOON. -PJC

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 308 PM MST THU FEB 14 2013

(FRIDAY NIGHT-THURSDAY)

FRIDAY NIGHT-SUNDAY...STRONG NORTH TO NORTHWEST FLOW ALOFT ACROSS
THE REGION FRIDAY NIGHT MODERATES AND BECOMES MORE WESTERLY THROUGH
THE DAY SUNDAY AS UPPER LEVEL RIDGING BUILDING ACROSS THE GREAT
BASIN FLATTENS ACROSS THE STATE AHEAD OF MORE SHORT WAVE ENERGY
MOVING ONSHORE ACROSS THE PAC NORTHWEST COAST. DRY WEATHER WITH WELL
ABOVE SEASONAL TEMPERATURES EXPECTED THROUGH THE FIRST PART OF THE
HOLIDAY WEEKEND...WITH BREEZY WEST WINDS ACROSS THE HIGHER TERRAIN
AND IMMEDIATE ADJACENT PLAINS SATURDAY AND SATURDAY NIGHT. SHOULD
SEE INCREASING HIGH CLOUDS FROM WEST TO EAST THROUGH THE DAY SUNDAY
AS THE SYSTEM CONTINUES TO MOVE ACROSS THE GREAT BASIN.

SUNDAY NIGHT-MONDAY NIGHT...STILL SOME MODEL DIFFERENCES ON AMPLITUDE
OF GREAT BASIN SYSTEM MOVING ACROSS THE ROCKIES WITH THE 12Z GFS
STILL DIGGING FURTHER SOUTH THAN THE ECMWF...HOWEVER THE GFS HAS
STARTED TO TREND FURTHER NORTH AND IS WEAKER WITH THE SYSTEM THAN
PREVIOUS RUNS. WITH THAT SAID...SHOULD STILL SEE A HEALTHY COLD
FRONT WITH A 10-20 DEGREE DROP IN TEMPERATURES FROM SUNDAY...MOST
NOTICEABLE ACROSS EASTERN COLORADO. HAVE ALSO KEPT ISOLATED TO
SCATTERED POPS INTACT ACROSS THE HIGHER TERRAIN AND IMMEDIATE
ADJACENT PLAINS...WITH NOT MUCH PRECIPITATION EXPECTED...ESPECIALLY
IF THE SYSTEM CONTINUES TO TREND FURTHER NORTH.

TUESDAY-THURSDAY...WARMER WESTERLY FLOW PROGGED ACROSS THE AREA
TUESDAY WITH INCREASING SOUTHWEST FLOW TUESDAY NIGHT AND WEDNESDAY
AHEAD OF A STRONGER SYSTEM MOVING INTO THE GREAT BASIN. SOME
DIFFERENCES IN MOVEMENT OF THIS SYSTEM WITH THE GFS LIFTING IT
ACROSS SOUTH CENTRAL COLORADO WEDNESDAY NIGHT AND INTO THE NORTHWEST
KANSAS ON THURSDAY. THE LATEST EC IS A TAD FURTHER SOUTH WITH THE
SYSTEM ACROSS SOUTHWEST KANSAS ON THURSDAY...WHICH PRODUCES BETTER
CHANCES OF SNOW AND BLOWING SNOW ACROSS THE SOUTHEAST PLAINS NORTH
OF HIGHWAY 50...ESPECIALLY AREAS ALONG THE PALMER DVD. AT ANY
RATE...MODEL CONSENSUS IS FAIRLY CONSERVATIVE THIS FAR OUT AND
HAVE INCREASED POPS TO CHANCES ALONG THE CONTDVD FOR THE WEDNESDAY
THROUGH EARLY THURSDAY PERIODS. HAVE ALSO INCREASED POPS TO SLIGHT
CHANCES ACROSS PORTIONS OF THE PLAINS. THIS SYSTEM WILL LIKELY
PRODUCE SIGNIFICANT WEATHER SOMEWHERE ACROSS THE REGION...THOUGH
TIME WILL TELL AS TO EXACTLY WHERE. -MW

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 308 PM MST THU FEB 14 2013

VFR CONDITIONS ARE EXPECTED AT ALL THREE TAF SITES...KALS...KCOS...AND
KPUB THROUGH TOMORROW AFTERNOON WITH AN OCCASIONAL DROP TO MVFR
CONDITIONS AT KCOS EARLY THIS EVENING DUE TO LIGHT SNOW SHOWER
ACTIVITY IN THE AREA. GUSTY WINDS FROM THE NORTH AND NORTHEAST
WILL DIMINISH LATER THIS EVENING. -PJC

.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM...PJC
LONG TERM...MW
AVIATION...PJC

AREA FORECAST DISCUSSION

NWS DENVER/BOULDER CO

939 AM MST THU FEB 14 2013

.UPDATE...

.SHORT TERM...CURRENT FORECASTS STILL SEEM ON TRACK AS UPPER
TROUGH MOVES ACROSS COLORADO. LATEST MODELS CONTINUE TO SHOW
DECENT MID LEVEL QG ASCENT SPREADING ACROSS THE AREA THROUGH THE
AFTERNOON. WEB CAMS ACROSS MOUNTAINS CONTINUE TO SNOW LIGHT SNOW
ACROSS MUCH OF THE AREA...DOESN`T APPEAR TOO HEAVY AT THIS TIME.
SNOW WILL CONTINUE THROUGH THE EVENING...WITH AMOUNTS LESS THAN
ADVISORY CRITERIA. ACROSS PLAINS...FRONT CURRENTLY MOVING SOUTH
ACROSS EASTERN LARIMER AND CENTRAL WELD COUNTIES...EXTENDING INTO
SOUTHERN MORGAN AND SOUTHERN WASHINGTON COUNTIES. RADAR SHOWING
BAND OF PRECIP ALONG AND NORTH OF THE FRONT. WEB CAMS IN THIS AREA
NOT SHOWING MUCH REACHING THE GROUND ALONG THE FRONT. FRONT TO
MOVE SOUTH DURING THE MORNING...WITH PRECIP SPREADING SOUTH AND
WEST. LATEST MODELS STILL POINTING AREAS ALONG FOOTHILLS AND
WESTERN SECTIONS OF URBAN CORRIDOR FOR THE HIGHER SNOW AMOUNTS
THROUGH THE AFTERNOON AS SEVERAL BANDS APPEAR TO CONVERGE IN THIS
AREA. OVERALL...LIGHT SNOW AMOUNTS STILL ON TRACK...WITH A GENERAL
1 TO 3 INCHES IN AND NEAR FOOTHILLS...WITH LESS AMOUNTS EASTWARD.
WILL NEED TO WATCH FOR ANY BANDS PARKING IN ONE AREA FOR AN
EXTENDED PERIOD WHICH COULD INCREASE SNOW AMOUNTS...AT THIS TIME
THE CHANCES OF THIS OCCURRING IS LOW. WILL ALSO NEED TO WATCH
AN AREA FROM EASTERN MORGAN COUNTY INTO WASHINGTON COUNTY AS THE
LATEST NAM AND THE LOCAL CAIC WRF RUC SUGGESTING A BAND OF 1 TO 3
INCHES IN THIS AREA BY 00Z.

.AVIATION...CURRENT TAF TRENDS STILL SEEM ON TRACK. FRONT AND
LEADING EDGE OF PRECIP BAND JUST NORTH AND EAST OF DIA...SLOWING
SAGGING SOUTHWARD. WINDS AT DIA NOW SHOWING SIGNS OF A NORTHEAST
DIRECTION. FRONT AND PRECIP TO SPREAD ACROSS THE DENVER AREA
THROUGH THE MORNING. CEILINGS AND VISIBILITY TO LOWER BY 18Z WITH
ILS CONDITIONS A GOOD BET. MVFR CONDITIONS TO PREVAIL BETWEEN 18Z
AND 03Z WITH POSSIBLE IFR CONDITIONS. ANY SNOW ACCUMULATIONS STILL
EXPECTED TO BE LESS THAN AN INCH. CONDITIONS TO GRADUALLY IMPROVE
AFTER 03Z BUT CEILINGS SHOULD REMAIN BELOW 7000 FEET AGL.

.PREV DISCUSSION... /ISSUED 330 AM MST THU FEB 14 2013/

SHORT TERM...A DISORGANIZED WEAK TROUGH WILL SLIDE FROM THE
NORTHERN ROCKIES ONTO THE PLAINS TODAY...BRINGING SOME WEAK LIFT
AND COLD ADVECTION ACROSS NORTHEASTERN COLORADO. GFS SEEMS TO HAVE
A BETTER HANDLE ON THE POSITION AND TIMING OF THE LIFT...NAM SEEMS
TOO FAR SOUTH WITH THE BEST LIFT AT THIS TIME. BEST ENHANCEMENT ON
SATELLITE UPSTREAM FROM DENVER ACTUALLY SEEMS TO HAVE VERY LITTLE
PRECIPITATION WITH IT...THE BANDED SHOWERS ARE IN THE COLDER AIR
FURTHER NORTH ACROSS WYOMING. EVEN THERE THE SHOWERS LOOK PRETTY
LIGHT. CURRENT MOTION WOULD HAVE THESE CLIPPING NORTHEASTERN
COLORADO THIS MORNING. HOWEVER...DEEPER COLD AIR WILL BE FORCED
SOUTHWARD BEHIND THE TROUGH...EVIDENCED BY PRESSURE RISES IN
MONTANA...AND THIS SHOULD HELP PULL THE SHOWER BANDS SOUTHWARD
THIS AFTERNOON. IN ADDITION THE CONVERGENCE THAT DEVELOPS IN AND
NEAR THE FOOTHILLS WILL LIKELY HELP FORCE SHOWERS SOMEWHERE IN
THAT AREA...PROBABLY WITH SOME MOTION TO THE BANDING IN THE COLD
ADVECTION. HARD TO SAY WHERE THE SYNOPTIC SCALE BANDS WILL
GO...BUT FAVORING THIS AREA OF CONVERGENCE AS THE MODELS DO MAKES
SENSE. AS A RESULT...EVEN THOUGH EXPECTED AMOUNTS WILL BE LIGHT
THE CHANCE OF GETTING A LITTLE SNOW AROUND DENVER LOOKS FAIRLY
GOOD FROM MID AFTERNOON INTO EARLY EVENING. EXPECT MOST PLACES
WILL HAVE LESS THAN AN INCH...THOUGH IF A BAND STALLS OR SOMEPLACE
GETS HIT MORE THAN ONCE HEAVIER SNOW WOULD BE POSSIBLE. WITH THE
FOOTHILLS FAVORED FOR A WHILE THE IDEA OF 1 TO 3 INCHES SEEMS
FINE.

MAIN CHANGES IN THIS PACKAGE WILL BE TO FOCUS MORE CLEARLY ON THE
AFTERNOON AND EVENING PERIODS...AND TO RAISE POPS IN THE HIGHER
MOUNTAINS AS WELL AS THERE COULD BE REPEATED PERIODS OF LIGHT
SNOW.

LONG TERM...ANOTHER BATCH OF ENERGY MOVES DOWN THE BACK SIDE OF
THE MEAN TROUGH EAST OF US ON FRIDAY. STRONG NORTHERLY FLOW ALOFT
IS PROGGED OVER THE CWA BY FRIDAY AFTERNOON INTO THE EVENING. BY
SATURDAY MORNING...THE FLOW ALOFT RELAXES AS AN UPPER RIDGE MOVES
EASTWARD. THE UPPER RIDGE MOVES ACROSS THE FORECAST AREA SATURDAY
NIGHT WITH FAIRLY WEAK ZONAL FLOW ALOFT. THE QG VERTICAL VELOCITY
FIELDS HAVE A BIT OF UPWARD MOTION PROGGED FRIDAY MORNING FOR THE
EASTERN THIRD OF THE CWA ONLY. IT`S ALL DOWNWARD MOTION FOR THE
REST OF FRIDAY THROUGH SATURDAY. VERY WEAK UPWARD MOTION IS
INDICATED FOR SATURDAY NIGHT. ON FRIDAY MORNING...THE BOUNDARY
LAYER FLOW BECOMES NORTHWESTERLY AND THAT CONTINUES INTO FRIDAY
EVENING...THEN THE FLOW IS WESTERLY THROUGH MUCH OF SATURDAY. ALL
DOWNSLOPING. FOR MOISTURE...THERE IS QUITE A BIT OVER MUCH OF THE
CWA FRIDAY...HOWEVER IS DOES GRADUALLY DECREASE THROUGH THE DAY.
MODELS HAVE IT PRETTY DRY BY 12Z SATURDAY MORNING. SATURDAY AND
SATURDAY EVENING ARE VERY DRY. THERE IS A BIT OF UPPER LEVEL
MOISTURE PROGGED TO MOVE INTO THE WESTERN HALF OF THE CWA SATURDAY
NIGHT LATE. THE QPF FIELDS HAVE A TAD OF MEASURABLE SNOWFALL OVER
THE MOUNTAINS AND EASTERN HALF OF THE PLAINS FRIDAY. AFTER THAT
THERE IS NOTHING THROUGH SUNDAY MORNING AT 12Z. WILL KEEP
"LIKELY"S GOING IN THE MOUNTAINS FOR SOME OF FRIDAY WITH THE
OROGRAPHICS AND MOISTURE IN MIND. WILL TAPER POPS OFF BY AFTERNOON
AND END THEM IN THE MOUNTAINS DURING THE EVENING. WILL LOWER POPS
TO NOTHING OR NEAR NOTHING OVER THE FOOTHILLS AND IMMEDIATE
PLAINS WITH THE STRONG DOWNSLOPE DRYING IN MIND ON FRIDAY. WILL
LEAVE SOME MINOR POPS OVER THE REST OF THE PLAINS FRIDAY. AFTER
THAT DRY FOR ALL AREAS THROUGH 12Z SUNDAY MORNING. FOR
TEMPERATURES...FRIDAY`S HIGHS WILL STAY CLOSE TO TODAY`S READINGS.
SATURDAY`S HIGHS ARE SUPPOSED TO WARM SOME 6-12 C FROM FRIDAY`S
READINGS. FOR THE LATER DAYS...SUNDAY THROUGH WEDNESDAY...MODELS
HAVE WEAK ZONAL FLOW OVER THE CWA SUNDAY. AN UPPER TROUGH IS TO
PUSH ACROSS COLORADO SUNDAY NIGHT INTO MONDAY MORNING. PRETTY
STRONG NORTHWESTERLY FLOW ALOFT IS PROGGED MONDAY INTO MONDAY
NIGHT...THEN ANOTHER UPPER RIDGE MOVES OVER THROUGH MID DAY
TUESDAY. FOR THE REST OF TUESDAY INTO EARLY WEDNESDAY...PRETTY
STRONG WEST-SOUTHWESTERLY FLOW ALOFT IS EXPECTED IN ADVANCE OF
THE NEXT UPPER TROUGH. THIS ONE LOOKS FAIRLY STRONG...BUT WHO
KNOWS? THE LAST SEVERAL SYSTEMS HAVE BEEN WEAK AND DISORGANIZED
AND POOR PRECIPITATION-MAKERS...YET THEY GENERALLY LOOKED MUCH
BETTER A FEW DAYS OUT. THE UPCOMING MONDAY TROUGH IS A GOOD
EXAMPLE...BUT THERE IS STILL TIME BEFORE IT ARRIVES. SO BY 00Z
LATE WEDNESDAY AFTERNOON...THE GFS SHOWS A PRETTY STRONG OPEN
TROUGH AXIS OVER THE WESTERN COLORADO BORDER. AT THE SAME
TIME...THE ECMWF HAS A CLOSED CIRCULATION AT THE BOTTOM OF ITS
UPPER TROUGH OVER THE SOUTHWESTERN CORNER OF COLORADO. THE TWO
MODELS ARE IN GOOD AGREEMENT TIMING-WISE. FOR MOISTURE...IT
INCREASES UP HIGH ON SUNDAY...AND THERE IS SOME FOR EARLY
MONDAY`S TROUGH...BUT NOTHING GREAT. YESTERDAY AND THE DAY
BEFORE`S 00Z MODEL RUNS HAD UPSLOPE AND DEEP MOISTURE FOR THE
PLAINS WITH THE EARLY MONDAY TROUGH...NOW THE ECMWF HAS LITTLE
MOISTURE AND NO UPSLOPE. THE GFS HAS BRIEF SHOT. AGAIN...THEY ARE
CHANGING FOR THE WORSE IF PRECIPITATION IS WHAT YOU SEEK.
TEMPERATURES WARM SUNDAY...THEN COOL OFF MONDAY...THEN WARM AGAIN
TUESDAY AND WEDNESDAY.

AVIATION...A COLD FRONT IS EXPECTED THROUGH DENVER IN THE 16Z TO
18Z RANGE WITH LOWERING CEILINGS AND NORTH WINDS GUSTING IN THE 20
TO 30 KNOT RANGE. EXPECT INSTRUMENT APPROACHES WILL BE NEEDED TO
KDEN BY 20Z...WITH PERIODS OF IFR CONDITIONS IN LIGHT SNOW SHOWERS
BETWEEN 21Z AND 03Z. THERE IS STILL A CHANCE OF LIGHT SHOWERS
AFTER THAT TIME...AND CEILINGS MAY REMAIN BELOW 7000 FT AGL THE
REST OF THE NIGHT...BUT WILL LIKELY BE HIGHER BY FRIDAY MORNING.
IF THERE IS SNOW ACCUMULATIONS ARE EXPECTED TO BE LESS THAN AN
INCH.

.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM...D-L
LONG TERM....RJK
AVIATION...D-L

AREA FORECAST DISCUSSION...UPDATED

NWS MIAMI FL

1250 PM EST THU FEB 14 2013

.AVIATION...
THE STATIONARY FRONT HAS MOVED BACK NORTH INTO THE LAKE OKEECHOBEE
AREA EARLY THIS AFTERNOON. THIS HAS ALLOWED FOR THE SKIES TO BECOME
PARTLY CLOUDY OVER MOST OF THE TAF SITES EARLY THIS
AFTERNOON...AND ALLOWED FOR THE EAST COAST SEA BREEZE TO SET UP
ALONG THE EAST COASTAL AREAS. THE EAST COAST SEA BREEZE WILL
CONTINUE TO PUSH SLOWLY INLAND THIS AFTERNOON ALLOWING FOR THE
WINDS AT KFLL TO REMAIN EASTERLY AT 5 TO 10 KNOTS...AND SWING TO A
EASTERLY DIRECTION AT KOPF TAF SITE AROUND 19Z AND THEN AT KMIA
TAF SITE AROUND 20Z. REST OF THE TAF SITES SHOULD REMAIN IN A
SOUTH TO SOUTHWEST DIRECTION THIS AFTERNOON AT 5 TO 10 KNOTS.

WITH THE EAST COAST SEA BREEZE SETTING UP ALONG THE EAST COAST
AREA AND THE SKIES BEING PARTLY CLOUDY...THIS WILL ALLOW FOR
SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP OVER THE EASTERN
AREAS OF THE CWA. SO HAVE INTRODUCE VCTS FOR ALL OF THE EAST COAST
TAF SITES UNTIL 01Z...EXCEPT FOR KPBI WHERE VCSH WILL REMAIN...DUE
TO THE FRONT LOCATED OVER THIS SITE. KAPF TAF SITE WILL ALSO ONLY
SEE VCSH FOR THIS AFTERNOON.

THE THUNDER THREAT OVER THE EAST COAST TAF SITES WILL COME TO AN
END AROUND 00Z TO 01Z TONIGHT...AS THE HEATING OF THE DAY IS LOST
AND THE WINDS BECOME MORE SOUTHWEST OVER THE TAF SITES AT 5 KNOTS
OR LESS.

AT THIS TIME THE VIS AND CEILING SHOULD REMAIN IN THE VFR
CONDITIONS OUTSIDE OF ANY SHOWERS AND THUNDERSTORMS THAT DO
DEVELOP. IN THE SHOWERS AND THUNDERSTORMS THE VIS AND CEILING
COULD FALL DOWN INTO THE IFR CONDITIONS.

&&
...AVIATION...54/BNB

.PREV DISCUSSION... /ISSUED 815 AM EST THU FEB 14 2013/

..ISOLATED TSTORMS, SOME COULD CONTAIN STRONG WIND GUSTS AND
LOCALLY HEAVY RAINFALL...

UPDATE...WAVES OF HEAVY SHOWERS CONTINUE TO MOVE NE ACROSS
COLLIER TO PALM BEACH COUNTIES. ONLY ONE LIGHTNING STRIKE NOTED
JUST OFF THE COLLIER COAST A COUPLE OF HOURS AGO. GIVEN RADAR AND
EXPECTED TRENDS, HAVE INCREASED POPS ACROSS THE AREA. HRRR SHOWS A
GENERAL DECREASING TREND LATER THIS MORNING BEFORE THINGS REV BACK
UP AGAIN THIS AFTERNOON...AND WITH SLIGHTLY BETTER HEATING ACROSS
BROWARD AND MIAMI-DADE COUNTIES, TSTORMS COULD ERUPT ABOUT
ANYWHERE BUT BETTER CHANCES THERE. MORNING ANALYSIS INDICATES THE
POTENTIAL FOR A FEW STRONG TSTORMS WITH GUSTY WINDS TO AROUND 50
MPH. THERE IS SOME INCREASING INSTABILITY ALONG WITH AN INCOMING
SHORTWAVE OVER THE GULF OF MEXICO WHICH COULD IGNITE A FEW STRONG
TSTORMS, PARTICULARLY THIS AFTERNOON INTO EARLY THIS EVENING.

TEMPS WERE LOWERED A BIT ACROSS SE AREAS SINCE CLOUDS ARE
INCREASING FROM THE WEST. THEREFORE, MAX TEMPS IN THE LOWER 80S
ARE NOW FORECAST WITH MID-UPPER 70S LAKE OKEECHOBEE REGION.

&&
/GREGORIA

PREV DISCUSSION... /ISSUED 621 AM EST THU FEB 14 2013/

&&
KOB

PREV DISCUSSION... /ISSUED 333 AM EST THU FEB 14 2013/

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 79 63 76 60 / 80 70 50 40
FORT LAUDERDALE 83 67 77 62 / 70 70 50 50
MIAMI 83 66 80 63 / 70 70 50 50
NAPLES 79 61 75 58 / 90 70 50 30

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&

DISCUSSION/MARINE/FIRE...55/CWC
AVIATION/RADAR...30/KOB

AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

320 PM CST THU FEB 14 2013

.SYNOPSIS...
18Z SURFACE ANALYSIS INDICATED LOW PRESSURE OVER NORTHERN LOWER MI
WITH A TROUGH OR WEAK COLD FRONT REACHING SOUTH-SOUTHWEST ACROSS
IL...MO INTO EASTERN OK. A SECOND REINFORCING COLD FRONT EXTENDED
WEST FROM THE LOW ACROSS WI TO ALONG THE IA/MN BORDER. SOUTH OF THIS
FRONT...TEMPERATURES WERE IN THE 30S TO LOWER 40S WITH BRISK W-NW
WINDS ACROSS THE FORECAST AREA. ALOFT...A BROAD CYCLONIC FLOW
ENCOMPASSED THE EASTERN 2/3RDS OF THE CONTINENTAL U.S. THERE WERE A
SERIES OF SHORTWAVES EMBEDDED IN THIS FLOW FROM THE GREAT LAKES TO
THE CANADIAN ROCKIES. THE FOCUS IN THE SHORT TERM IS A VORT MAX
EVIDENT ON SATELLITE WV IMAGES OVER N CENTRAL IA...WHERE AREA RADARS
AND SURFACE REPORTS WERE INDICATING SNOW SHOWERS.

.SHORT TERM...TONIGHT AND FRIDAY...
MAIN FOCUS IS ON THE SNOW SHOWERS THAT WILL OVERSPREAD THE AREA
LATE THIS AFTERNOON AND EVENING...THEN COOLER TEMPERATURES AND
POTENTIAL FLURRIES THROUGH FRIDAY.

AN AXIS OF ROTATION SEEN IN RECENT KDMX 88D LOOPS INDICATED THE
UPSTREAM VORT MAX WAS CENTERED ROUGHLY NORTH OF WEBSTER CITY AT 20Z.
THIS WAS WELL SOUTH OF THE OPERATIONAL NAM...GFS AND ECMWF TRACKS
FROM THIS MORNING. THE RECENT RAP RUNS APPEARED TO HAVE A DECENT
CAPTURE OF THIS VORT CENTER AND WILL FOLLOW ITS OVERALL
SOUTHEASTWARD TRACK. THIS WILL SEND THE UPSTREAM SNOW SHOWERS...
TRENDING HEAVIEST ALONG AND NORTH OF THE VORT MAX...SOUTHEAST
THROUGH THE EAST CENTRAL IA AND THEN W CENTRAL IL OVER THE NEXT
SEVERAL HOURS. COLD ADVECTION ALOFT WAS SHOWN LEADING TO STEEP MID
LEVEL LAPSE RATES ON THE ORDER OF 7 TO 8 DEG C/KM IN THIS MORNING/S
MODEL RUNS. THIS...COMBINED WITH THE UPPER LEVEL FORCING AND LIFT
ALONG THE SOUTHWARD MOVING COLD FRONT WILL SUPPORT CONTINUED LIGHT
TO MODERATE SNOW SHOWERS AND AT LEAST LIGHT ACCUMULATIONS. THE HIGH
RES RAP CONTINUES TO INDICATE QPF VALUES IN THE RANGE OF .2 TO .3
INCHES AS SNOW SHOWERS TRACK FROM ABOUT CID THROUGH THE QUAD CITIES
TO NEAR KEWANEE BETWEEN 23Z AND 05Z AND HAVE LIKELY POPS ALONG THIS
AXIS. WHILE THIS LOOKS OVERDONE BASED ON MEAGER PRECIPITATION
AMOUNTS REPORTED SO FAR AT AUTOMATED UPSTREAM SITES...CANNOT RULE
OUT BANDS OF 1 TO POSSIBLY 2 INCH SNOW ACCUMULATIONS IF THE
CONVECTION TAPS INTO THE DEEPER INSTABILITY OVER THE NEXT SEVERAL
HOURS. BASED ON THE INITIAL WARM LOW LEVELS AND TEMPERATURES IN
THE 30S TO LOWER 40S LEADING TO A RAIN/SNOW MIX AT ONSET...WILL
STAY CLOSE TO A MORE CONSERVATIVE .5 TO 1 INCH SNOWFALL RANGE FOR
NOW AND WATCH TRENDS CLOSELY.

THE CURRENT PACE OF THE VORT MAX SHOULD SEND THE SHOWERS EAST OF THE
AREA BY MID EVENING...AND HAVE ONLY SLIGHT CHANCE POPS AFTER
MIDNIGHT IN THE EAST AND SOUTHEAST. THE COLD FRONT SHOULD SLIDE
THROUGH THE ENTIRE AREA BY MIDNIGHT...FOLLOWED BY PARTIAL CLEARING
BASED ON SATELLITE TRENDS. GUIDANCE LOWS BY SUNRISE IN THE MID TEENS
NORTH TO MID 20S SOUTH LOOK REASONABLE.

FRIDAY...WILL KEEP A MENTION OF SCATTERED FLURRIES GOING IN THE
FORECAST BASED ON THE STREAM OF WEAK IMPULSES AND MID LEVEL MOISTURE
IN THE CYCLONIC FLOW ALOFT. CLOUD COVER AND COLD AIR ADVECTION
SHOULD LIMIT THE DIURNAL TEMPERATURE RISE. HAVE STAYED CLOSE TO
THE PREVIOUS FORECAST AND LATEST MODEL GUIDANCE WITH HIGHS
RANGING FROM THE LOWER 20S NORTH TO LOWER 30S SOUTH.

SHEETS

.LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY
FRIDAY NIGHT AND SATURDAY WE REMAIN IN THE NORTHWEST CYCLONIC FLOW
AND STEEP MID LEVEL LAPSE RATES WITH ENOUGH LOW LEVEL MOISTURE TO
ALLOW FOR FLURRIES DURING THE OVERNIGHT AND SATURDAY MORNING. WE
ALSO HAVE SOME UPPER LEVEL VORT MAXES THAT SHOULD ALSO HELP TO
TRIGGER THESE FLURRIES. THERE IS NOT REALLY ENOUGH MOISTURE FOR MORE
THAN THAT...THOUGH A DUSTING IS POSSIBLE IF REPEAT ACTIVITY AFFECTS
THE SAME AREA. TEMPERATURES TO REMAIN COLD THROUGH SATURDAY WITH
HIGHS SATURDAY IN THE 20S TO AROUND 30. WARMED MINS FRIDAY NIGHT DUE
TO THE EXTRA CLOUD COVER AND RANGE FROM 10-20.

STRONG WARM AIR ADVECTION SETS IN OVER THE AREA AT 850MB SATURDAY
NIGHT AND SUNDAY. THIS IS LIKELY TO BRING ANOTHER BAND OF CLOUD
COVER ACROSS THE AREA OVERNIGHT AND SUNDAY MORNING. SATURDAY NIGHT
MINS ARE LIKELY TO NOT SHOW MUCH CHANGE YET AS MOST OF THE WARMING
IS ALOFT. SUNDAY HOWEVER WE ARE LIKELY TO SEE A BIG WARM-UP WITH
HIGHS IN THE MID 30S NORTHEAST TO THE UPPER 40S SOUTHWEST.
TEMPERATURES APPROACHING 50 ARE POSSIBLE IF WE CAN CLEAR OUT AND MIX
DEEPLY ENOUGH.

THE NEXT PUZZLE OF THE DAY IS MONDAY AND MONDAY NIGHT AS OUR NEXT
STRONG STORM SYSTEM CROSSES THE MIDWEST. A RELATIVELY SHALLOW
LONGWAVE TROUGH MOVES ACROSS THE AREA WITH TWO SEPARATE PIECES OF
ENERGY...ONE FARTHER NORTH THAT GENERATES A SURFACE LOW OVER
SOUTHERN MINNESOTA BY MONDAY MORNING. ANOTHER PIECE OF ENERGY IS
OVER NEW MEXICO WHICH GENERATES A SURFACE LOW OVER OKLAHOMA AT THE
SAME TIME. THIS SYSTEM SWEEPS OUT ACROSS THE MIDWEST MONDAY AND
MONDAY NIGHT. MODELS HAVE BEEN VARYING ON HOW WELL PHASED THESE
SYSTEMS WILL BE OVER THE PAST COUPLE DAYS AS WELL AS HOW MUCH ENERGY
WILL BE WITH EACH. THUS...THE IMPACT FOR OUR CWA HAS VARIED FROM
DRY TO A RAIN/SNOW MIX. FOR NOW MODELS ARE COMING IN A LITTLE
SLOWER AND STRONGER...AND ARE BRINGING MORE MOISTURE AND WARMTH INTO
THE AREA. THUS...HAVE RAISED POPS THROUGH THE PERIOD. ALSO...HAVE
CONVERTED MONDAY TO NEARLY ALL RAIN...WITH JUST A RAIN SNOW MIX
ACROSS THE NORTH. MONDAY NIGHT WE GRADUALLY SWITCH TO ALL
SNOW...BUT THE TIMING IS STILL VERY MUCH UP IN THE AIR. DUE TO THE
START BEING ALL RAIN...SNOWFALL AMOUNTS WILL BE LIGHT.

TUESDAY AND WEDNESDAY ARE RELATIVELY QUIET WITH A STRONG SURFACE
RIDGE BUILDING INTO THE AREA FOR DRY AND COLD CONDITIONS. IN
FACT...IF WE CAN GET DECENT RADIATIONAL CONDITIONS FOR TUESDAY NIGHT
MIN TEMPS COULD DIP INTO THE SINGLE DIGITS OVER A FAIRLY LARGE
PORTION OF THE AREA. HOWEVER...THIS IS STILL SOMEWHAT QUESTIONABLE
AND HAVE STAYED A LITTLE WARMER FOR NOW.

THE BIG QUESTION OF THE FORECAST COMES THURSDAY. FOR SEVERAL MODEL
RUNS NOW...THE ECMWF AND GFS HAVE BEEN ADVERTISING A VERY STRONG
STORM FOR THE MIDWEST ON THURSDAY AND FRIDAY. THERE IS REMARKABLE
CONSISTENCY AND CONFIDENCE IS GROWING THAT SOMEWHERE IN THE MIDWEST
THERE WILL BE A MAJOR WINTER STORM...IF NOT A BLIZZARD.
HOWEVER...WHETHER OUR AREA WILL BE AFFECTED OR NOT IS VERY MUCH IN
QUESTION. WE CURRENTLY HAVE DIFFERING MODEL SOLUTIONS...ONE OF WHICH
DEPICTS THE WINTER STORM AFFECTING THE CWA WITH MAJOR SNOW
ACCUMULATIONS...ANOTHER WHICH BRINGS IN MORE WARM AIR AND AFFECTS US
WITH ANOTHER RAIN/SNOW MIX EVENT WITH LESSER ACCUMULATIONS. IN
GENERAL PREFER THE MORE CONSISTENT AND BETTER VERIFYING ECMWF WHICH
HAS THE LARGER SNOW ACCUMULATIONS...BUT CANNOT TOTALLY DISCOUNT THE
WARMER GFS EITHER. WE WILL HAVE TO WATCH THIS STORM VERY CAREFULLY
OVER THE NEXT SEVERAL DAYS TO MONITOR THESE TRENDS. YOU WILL
DEFINITELY WANT TO KEEP UP WITH THE LATEST INFORMATION REGARDING
THIS WINTER STORM SYSTEM. FOR NOW THE LATEST FORECAST REFLECTS A
BLENDED APPROACH...AND WE WILL HAVE TO REFINE WITH LATER FORECASTS.

..LE..

.AVIATION...
AN UPPER LEVEL DISTURBANCE AND SOUTHWARD MOVING SURFACE COLD FRONT
WILL COMBINE TO PRODUCE SNOW SHOWERS OVER EASTERN IA INTO NW IL
THIS AFTERNOON AND EVENING. THIS WILL CAUSE CIGS TO LOWER TO
MVFR THIS EVENING. SNOW SHOWERS AND POSSIBLE IFR VISIBILITIES NOW
APPEAR MOST LIKELY TO AFFECT THE CID AND MLI TERMINALS...MAINLY IN
A WINDOW BETWEEN 22Z AND 03Z THIS EVENING. WEST TO NW WINDS FROM
14 TO 24 KTS WILL DIMINISH AND VEER TO MORE PREDOMINANTLY
NORTHWEST DURING THIS TIME. OVERNIGHT...AT LEAST PARTIAL CLEARING OF
CLOUDS IS EXPECTED WITH CONDITIONS IMPROVING TO VFR. AN UNSETTLED
PATTERN WILL CONTINUE INTO FRIDAY...WITH PREVAILING VFR CONDITIONS
EXPECTED WITH POSSIBLE FLURRIES THROUGH THE DAY.

SHEETS

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

SHEETS/LE

AREA FORECAST DISCUSSION

NWS DES MOINES IA

310 PM CST THU FEB 14 2013

.SHORT TERM /TONIGHT/...
FORECAST CONCERN IS FOCUSED ON QUICK MOVING SHORTWAVE TO BRING SOME
LIGHT PRECIP TO THE FORECAST AREA THROUGH THIS EVENING. WEAK BROAD
FORCING ALONG THE COLD FRONT WILL BRING LIGHT SNOW OR RAIN THROUGH
THE LATE AFTERNOON BEFORE SWITCHING OVER TO ALL SNOW AFTER 00Z
FRIDAY. BUFR SOUNDINGS SHOWING BRIEF WINDOW OF FAIRLY DEEP
SATURATION FROM 21Z OR CURRENTLY THROUGH 03Z FRIDAY. COLUMN LOSES
ICE INTRODUCTION AND FORCING ACROSS NORTHERN IOWA B/T 00-03Z.
BELIEVE MODELS ARE BIT SLOW WITH MOVING THIS SYSTEM OUT AND CUT BACK
ON POPS PAST 03Z. 17Z HRRR QUICKLY DIMINISHES PRECIP BY 02Z WHICH
COINCIDES WITH SEVERAL OF THE HIRES WRF MODELS AND NAM12. ALSO
DECREASED SNOW AMOUNTS WITH THE QUICKER MOVEMENT...WEAKER FORCING
AND LESS MOISTURE AVAILABLE.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
COLD AIR SETTLING INTO THE REGION BY 12Z FRIDAY WITH GENERALLY A
CLOUDY DAY IN STORE. LINGERING FLURRIES WILL BE POSSIBLE FRIDAY WITH
WEAK WAVE PASSING THROUGH THE REGION DURING THE DAYTIME HOURS.
OTHERWISE TEMPERATURES WILL CREEP BACK UP DURING THE DAY TO NEAR 20
NORTH AND THE LOWER 30S IN THE SOUTH. AS HIGH BUILDS SOUTH FRIDAY
NIGHT SKIES WILL CLEAR OUT AND COLDER NIGHT IN STORE. LOWS WILL DROP
OFF INTO THE SINGLE DIGITS NORTH WITH THE TEENS IN THE SOUTHEAST.
H850 TEMPS REMAIN RATHER COLD THROUGH THE EARLY PART OF THE FORECAST
BUT AS THE RIDGE AXIS SLIPS EAST SATURDAY EVENING...TEMPS WARM
OVERNIGHT INTO SUNDAY MORNING. WARM AIR ADVECTION WILL INITIATE
CLOUDS WITH GENERALLY LIGHT FLOW OVERNIGHT. BY SUNDAY MED RANGE
MODELS CONTINUE WITH PREVIOUS RUNS TO SHOW DECENT WARM UP BY LATE
DAY. H850 TEMPS WARM TO NEAR 0C NORTHEAST AND TO NEAR 4-5C SOUTHWEST
AND WEST BY 00Z. THIS BODES WELL FOR TRENDS OF HIGHS IN THE 50S
ACROSS THE SOUTHWEST PORTION OF THE FORECAST AREA WITH HIGHS ABOVE
THE FREEZING MARK IN THE NORTHEAST. AS THE NEXT UPSTREAM WAVE
APPROACHES THE AREA ANOTHER STRONG COLD FRONT WILL PASS SOUTHEAST
THROUGH IOWA ON MONDAY. LIFT ASSOCIATED WITH IT WILL ALLOW FOR A
RAIN OR RAIN/SNOW MIXTURE TO OCCUR SOUTHEAST BY LATE IN THE
AFTERNOON. ANOTHER STRETCH OF COLDER THAN NORMAL WEATHER IS
ANTICIPATED FOR THE EARLY PORTION OF NEXT WEEK WITH A SLOW
MODERATION TOWARD THURSDAY...BUT STILL BELOW THE FREEZING MARK. MED
RANGE MODELS STILL PAINT AN ACTIVE STORM OVER THE FORECAST AREA BY
LATE WED OR EARLY THURSDAY WITH THE MAIN PORTION OF THE STORM TO HIT
THURSDAY THROUGH FRIDAY. SIGNATURE HAS SHOWN UP FOR TWO DAYS NOW IN
MOST MED RANGE MODELS...BUT EVEN SO...AT SEVEN DAYS OUT THERE ARE
STILL TO BE MANY CHANGES IN THE TRACK AND DETAILS. AT THIS TIME WILL
EMPHASIZE ONLY A STRONGER SYSTEM OVER THE CENTRAL STATES LOOKS MORE
LIKELY BUT WAY TOO EARLY TO BECOME OVERLY EXCITED ABOUT MODEL
DETAILS...ESPECIALLY GIVEN THAT THE 12Z GFS IS ABOUT 10 MB STRONGER
THAN THE 12Z EURO MODEL TODAY.

.AVIATION...14/18Z
INTERMITTENT MVFR STRATUS WILL PERSIST THROUGH THE AFTERNOON AND LOW
CONFIDENCE WITH AN EXTENDED PERIOD OF MVFR STRATUS...BUT HIGH ENOUGH
TO MENTION TIMING WITH A TEMPO. COLD FRONT DRAPED ACROSS NORTHERN
IOWA WILL CONTINUE TO PUSH SOUTHWARD THROUGH THE AFTERNOON HOURS AND
LOOKS TO HAVE A LITTLE THICKER STRATUS BEHIND IT. LATEST HRRR HAS
CIGS FILLING BACK INTO CENTRAL IOWA PAST 20Z THIS AFTERNOON. OTHER
CONCERN IS WITH MVFR/IFR VIS DUE TO LIGHT SNOW DEVELOPING LATER THIS
AFTERNOON ALONG AND BEHIND THE FRONT. HAVE MENTION LOWER VIS AT
MCW/FOD/ALO THIS AFTERNOON. MAY SEE LOWER VIS AT DSM/OTM BY THE
EARLY EVENING BUT HAD LOW CONFIDENCE WITH MENTION AS NOT EXPECTING
TO BE PERSISTENT.

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

SHORT TERM...PODRAZIK
LONG TERM...REV
AVIATION...PODRAZIK

AREA FORECAST DISCUSSION

NWS DES MOINES IA

1143 AM CST THU FEB 14 2013

....UPDATED FOR 18Z AVIATION DISCUSSION...

.SHORT TERM /TODAY/...
FIRST SHORTWAVE IS CURRENTLY SKIRTING THE NORTHEAST CORNER OF THE
STATE THIS MORNING WITH FIRST PUSH OF SLIGHTLY COOLER AIR INTO THE
STATE. HOWEVER...A SECOND SHORTWAVE WILL DROP SOUTHEAST THROUGH THE
DAKOTAS AND INTO THE STATE BY THIS AFTERNOON. WEAK TO MODERATE
FRONTOGENESIS WILL DROP INTO NORTH CENTRAL IOWA THIS AFTERNOON
ASSOCIATED WITH THIS WAVE ALONG WITH WEAK ISENTROPIC LIFT. FAIRLY
DEEP SATURATION AS WELL INDICATED IN THE BUFR SOUNDINGS AND LIGHT
SNOW IS EXPECTED IN THE NORTH DURING THE AFTERNOON. FARTHER
SOUTH...SOUNDINGS ARE WARMER AND IT APPEARS SOME THREAT OF RAIN AND
SNOW EXISTS AND HAVE MAINTAINED SOME MIX WITH INITIAL ONSET OF ANY
PCPN. SOUNDINGS MIX NICELY IN THE LOW LEVELS TODAY AND TEMPERATURES
SHOULD WARM BEFORE THE BIGGER PUSH OF COLD AIR ARRIVES LATE TODAY
INTO TONIGHT. AT THIS POINT...SNOW TOTALS IN THE NORTH WILL LIKELY
BE AROUND AN INCH.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
INITIALLY NORTHWEST TO NORTHERLY FLOW ALOFT REMAINS ACROSS THE
REGION...WITH A WEAK SHORTWAVE SLIDING SOUTHEASTWARD THROUGH THE
STATE TONIGHT. THIS WILL USHER IN ANOTHER PUSH OF COLD AIR...AND
PROVIDE SUPPORT FOR SOME LIGHT SNOW ACROSS MUCH OF THE CWA THIS
EVENING. EXPECT A BAND OF SNOW TO BE ORIENTED IN VICINITY OF THE HWY
20 CORRIDOR BY EARLY EVENING...WITH THE BAND MOVING OUT OF THE
SOUTHERN CWA BY THE EARLY MORNING HOURS. ANY ACCUMULATIONS SHOULD
REMAIN LIGHT WITH MOST SITES AROUND A HALF INCH OR LESS...WITH A FEW
LOCATIONS POSSIBLY RECEIVING AS MUCH AS AN INCH. WITH THE CONTINUED
PUSH OF COLD AIR INTO THE STATE...AND CYCLONIC FLOW ALOFT SCATTERED
FLURRIES EXPECTED TONIGHT THROUGH FRIDAY NIGHT. ANOTHER WEAK IMPULSE
ALSO SET TO DROP THROUGH THE CWA FRIDAY AFTERNOON. SOUNDINGS SHOWING
LITTLE MOISTURE THOUGH...SO HAVE JUST STUCK WITH THE FLURRY MENTION
WITH THIS WAVE. UPPER TROUGH TO FINALLY PUSH EAST OF THE REGION THIS
WEEKEND...WITH UPPER LEVEL RIDGING BUILDING INTO THE CENTRAL US
SATURDAY INTO SUNDAY.

RETURN FLOW WILL SETUP ACROSS THE REGION LATE SATURDAY NIGHT INTO
SUNDAY...WITH STRONG PUSH OF WAA SENDING H85 TEMPS INTO THE +4C
RANGE. WITH SOUTH TO SOUTHWEST FLOW AT THE SURFACE AND ALOFT AND
WITH MOSTLY SUNNY SKIES...SHOULD WARM UP NICELY SUNDAY. THEREFORE
CONTINUED TO GO ABOVE GUIDANCE FOR TEMPS SUNDAY....PUSHING TEMPS
INTO THE 40S/AROUND 50 ACROSS THE SOUTHWESTERN HALF OF THE CWA. AN
UPPER LEVEL WAVE THEN DIGS INTO THE NORTHERN US...SLIDING THROUGH
THE REGION BY MONDAY INTO MONDAY NIGHT. THE ASSOCIATED COLD FRONT
WILL SWEEP ACROSS THE CWA MONDAY...WITH A CHANCE FOR SOME LIGHT RAIN
EXPECTED TO DEVELOP IN VICINITY OF THE FRONT ACROSS THE SOUTHEASTERN
CWA MONDAY. OTHERWISE REMAINDER OF CWA SHOULD REMAIN DRY...AS DEF
ZONE PRECIP SHOULD SKIRT THE CWA TO THE NORTH/EAST. COULD SEE SOME
FLURRIES ACROSS THE FAR NORTH...BUT FOR NOW HAVE LEFT DRY. OTHERWISE
COLD AIR REMAINS IN PLACE THROUGH MUCH OF THE EXTENDED WITH HIGH
PRESSURE AND DRY CONDITIONS EXPECTED FOR TUESDAY INTO EARLY
WEDNESDAY.

LONG RANGE MODELS STILL IN VERY GOOD AGREEMENT DIGGING A DEEP UPPER
LEVEL TROUGH OVER THE INTERMOUNTAIN WEST BY MID WEEK...WITH THIS
SYSTEM EXPECTED TO EJECT EASTWARD THROUGH THE REGION JUST BEYOND THE
CURRENT FORECAST PERIOD TOWARD THURSDAY INTO FRIDAY. WITH MANY
DETAILS REMAINING UNCERTAIN THIS FAR OUT...STILL LOOKS LIKE AN
INCREASING LIKELIHOOD THAT A LARGE STORM SYSTEM COULD IMPACT THE
AREA BY THE END OF NEXT WEEK.

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

SHORT TERM...COGIL
LONG TERM...BEERENDS
AVIATION...PODRAZIK

AREA FORECAST DISCUSSION...UPDATED

NWS WAKEFIELD VA

434 PM EST THU FEB 14 2013

.SYNOPSIS...
HIGH PRESSURE SLIDES OFF THE COAST TONIGHT AND A COLD FRONT
APPROACHES THE MID ATLANTIC REGION ON FRIDAY. THE COLD FRONT
WILL PASS THROUGH THE AREA FRIDAY NIGHT...FOLLOWED BY UNSETTLED
CONDITIONS AND A COOLER CANADIAN AIRMASS FOR THE REMAINDER OF THE
WEEKEND.

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
HIGH PRESSURE SLIDES OFF THE COAST TONIGHT. AS THIS HAPPENS...A
STEADY STREAM OF MID TO HIGH LEVEL CLOUDS OVER SE VA AND NE NC WILL
GRADUALLY MOVE EWD WITH THE BACK EDGE OF THE RIDGE. EXPECT MOSTLY
CLEAR SKIES AREAWIDE TONIGHT WITH LOWS IN THE 30S (NEAR 40 IMMEDIATE
COAST).

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
FRIDAY AND FRIDAY NIGHT...
FRIDAY WILL BE A DAY OF TRANSITION WITH HIGH PRESSURE OFF THE
COAST AND A COLD FRONT APPROACHING FROM THE WEST. THE DAY WILL
START OFF MOSTLY SUNNY BUT HIGH CLOUDS WILL MOVE INTO THE AREA
FROM THE NORTHWEST DURING THE AFTN. THE COLD FRONT...WHICH EXTENDS
FROM A LOW PRESSURE SYSTEM TRACKING ACROSS THE ST LAWRENCE RIVER
VALLEY...WILL PASS THROUGH THE AREA FRIDAY NIGHT. PRECIP BEGINS AS
ALL RAIN AND IS EXPECTED TO CHANGE OVER TO SNOW OR A RAIN/SNOW MIX
AFTER MIDNIGHT AS COLD AIR INFILTRATES THE WRN HALF OF THE FA.
EXPECT SNOW OVER FAR NW AREAS...AND A RAIN/SNOW MIX GENERALLY
ALONG THE I-95 TRAVEL CORRIDOR BY EARLY SATURDAY MORNING.

SATURDAY AND SATURDAY NIGHT...
AN AREA OF LOW PRESSURE IS NOW PROGGED TO DEVELOP OFF THE NC COAST
EARLY SATURDAY AND STAY JUST OFF THE MID ATLANTIC COAST DURING THE
DAY. MEANWHILE SHORTWAVE ENERGY ROUNDING THE BASE OF THE DEEP
UPPER LEVEL TROUGH...A STRONG JET STREAK MAXING OUT AROUND 150 KT...
AND PLENTY OF COLD CANADIAN AIR ON THE BACK SIDE OF THE LOW WILL
MAKE FOR AN INTERESTING FORECAST. THE NAM AND GFS MODELS ARE IN
FAIR AGREEMENT WITH THE PLACEMENT OF THE DEVELOPING LOW PRESSURE
CENTER (NAM IS A BIT FURTHER TO THE EAST BUT NOT BY MUCH) AND ALSO
WITH GENERAL PLACEMENT OF QPF. THE GFS IS BULLISH WITH THE 6HR
PRECIP AMTS AND THE NAM APPEARS TO BE TOO LIMITED WITH ITS QPF
COVERAGE/AMTS DUE TO ITS CONVECTIVE PARAMETERIZATIONS. HIGHER QPF
AMOUNTS ARE ANTICIPATED TO OCCUR GENERALLY ALONG AND NORTH OF I-64
INCLUDING THE MD/VA EASTERN SHORE. ALSO...A VERY TIGHT PRESSURE
GRADIENT DEVELOPS DUE TO COLD AND DRY CANADIAN AIR TO THE
NORTHWEST AND WARM/MOIST AIR TO THE SOUTHEAST. NORTHWEST WINDS
WILL BECOME BREEZY...ESPECIALLY ALONG THE COAST.

THE CLASH OF AIRMASSES SHOULD KEEP PERSISTENT WINTRY PRECIP OVER
FAR NW AREAS THROUGH MOST OF THE DAY SATURDAY. HAVE INTRODUCED A
COMBO OF SNOW AND SLEET (REALLY GRAUPEL AKA SNOW GRAINS) DURING
THE DAY AS THE UPPER LEVEL TROUGH ENHANCES CONVECTIVE PRECIP AND
WILL HELP DRIVE DOWN SNOW LEVELS AND WET BULB ZERO HEIGHTS. BY
LATE AFTN/EARLY SATURDAY EVENING...WINTRY PRECIP IS EXPECTED TO
SHIFT FURTHER TO THE SOUTHEAST AS A SNOW/GRAUPEL MIX WITH RAIN
NEAR THE IMMEDIATE COAST. AS THE COASTAL LOW TRACKS TO THE
NORTHEAST DURING THE EVENING AND TEMPERATURES BEGIN TO DROP...
PRECIP SHOULD BECOME ALL SNOW BY LATE EVENING. STORM TOTAL SNOW
ACCUMULATIONS AT THIS TIME RANGE FROM 0.6-1.6 INCHES NORTH OF A
LINE FROM FVX-RIC-SBY...AND 0.5 INCHES OR LESS SOUTH OF THIS LINE.
THE POTENTIAL FOR WINTRY CONDITIONS WILL BE COVERED IN THE
HAZARDOUS WEATHER OUTLOOK AT THIS TIME.

PRECIP IS EXPECTED TO QUICKLY SHUT OFF LATE SATURDAY EVENING ONCE
THE LOW MOVES AWAY FROM THE MID ATLANTIC COAST. COLDER AIR WILL BE
ABLE TO TAKE HOLD OF THE REGION SATURDAY NIGHT DESPITE DECENT
MIXING PROVIDED BY NORTHWEST REMAINING ELEVATED OVERNIGHT.
ANTICIPATE LOWS IN THE 20S. THE REGION WILL STAY UNDER THE
INFLUENCE OF A BROAD UPPER LEVEL TROUGH THROUGH SUNDAY. COLDER AIR
AND BREEZY WNW WINDS SHOULD PRODUCE WIND CHILLS IN THE UPPER TEENS
TO LOWER 20S SUNDAY MORNING. EXPECT COOL HIGHS WITH TEMPS IN THE
MID TO UPPER 30S (NEAR 40 IMMEDIATE COAST).

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WILL LEAN TOWARD HPC GUIDANCE. THIS LEANS TOWARD A ECMWF ENSEMBLE
SOLUTION. AFTER THE COLD FRONT AND LOW MOVE AWAY SUNDAY SHOULD BE
A SUNNY COLD BREEZY DAY WITH TEMPERATURES BELOW NORMAL. IT SHOULD
CONTINUE DRY THROUGH MONDAY WITH JUST A SLIGHT WARM UP ON MONDAY.
THE FIRST SYSTEM TO IMPACT THE AREA WILL BE ON TUESDAY. BOTH GFS
AND ECMWF ARE SIMILAR WITH THE MAIN LOW GOING UP TO THE WEST OF
THE AREA AND PLENTY OF WARM AIR ARRIVING AHEAD OF THE PRECIPITATION
SO WENT WITH MAINLY A RAIN EVENT. THE FRONT WILL AGAIN PUSH THROUGH
ON TUESDAY NIGHT WITH PLENTY OF COLD AIR AND THERE COULD BE SOME
MIX OR CHANGE TO SNOW SHOWERS AS THE FRONT PASSES. THE NEXT SYSTEM
APPROACHES TOWARD THE END OF THE PERIOD. THE MODELS CONSENSUS
WOULD KEEP IT MAINLY OUT OF THE AREA UNTIL FRIDAY SO KEPT IT DRY
THROUGH THURSDAY. FOLLOWED ALONG CLOSE TO MOSGUIDE TEMPERATURES
WHICH WERE ALSO CLOSE TO HPC. THIS KEEPS TEMPERATURES BELOW NORMAL
FOR WEDNESDAY AND THURSDAY.

.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
LOOKING AT RAP SOUNDINGS CAN SEE ENOUGH MOISTURE IN THE BOUNDARY
LAYER FOR SOME CLOUDS AND HAVE SEEN ESPECIALLY TOWARD THE COAST A
BKN LAYER CLOSE TO 3000 FEET. THIS WILL SLOWLY LIFT AND DISSIPATE
AS THE AFTERNOON GOES ON WITH MAINLY CLEAR SKIES BY EVENING. WINDS
WILL BE VARIABLE AND LIGHT. CONTINUED VFR CONDITIONS TONIGHT AND
FRIDAY.

A STRONG COLD FRONT MOVES THROUGH THE AREA LATE FRIDAY NIGHT/EARLY
SATURDAY MORNING. THERE IS A CHANCE OF RAIN AND/OR SNOW SHOWERS
WITH THE FRONTAL PASSAGE ESPECIALLY FROM NW OF A LINE FROM RIC TO
SBY AND THIS COULD LEAD TO MVFR OR IFR CONDITIONS FOR A TIME AS
INTO SATURDAY AFTERNOON BEFORE VFR BUT BREEZY CONDITIONS RETURN
FOR THE REST OF THE WEEKEND.

.MARINE...
SFC HI PRES MOVES OVR THE WTRS FM THIS EVE THROUGH FRI MRNG. NEXT
CDFNT APPROACHES FM THE W FRI AFTN/EVE...AND SLOWS AT IT REACHES
THE CST SAT MRNG. MEANWHILE...WK SFC LO PRES BEGINS TO DVLP A FEW
HUNDRED MI OFF THE NC/SC CST SAT MRNG. 12Z/14 NAM/GFS BOTH
GRADUALLY INTENSIFY THE LO AS IT TRACKS NNE OFFSHR SAT INTO SAT
NGT...(THE GFS MORE SO THAN THE NAM...AS WELL AS BEING CLOSER TO
THE IMMEDIATE CST). CONTG W/ IDEA OF DELAY IN STRONGEST LO LVL CAA
UNTIL SAT EVE THROUGH SUN...AS A RESULT OF THE STRENGTHENING SFC
LO PRES TRACKING E OF CAPE COD...AND THE MID/UPR LVL TROUGH
CROSSES THE MDATLC RGN. INCRSG CONFIDENCE FOR SOLID SCAS FM LT SAT
THROUGH SUN...W/ (RIGHT NOW AT LEAST) A LO PROB FOR A PD OF
GALES...ESP ON THE NRN OCN WTRS. LO LVL CAA RMNS THROUGH SUN
NGT/ERY MON...BEFORE WANING DURG MON AS SFC HI PRES ARRIVES FM THE
W/TROUGH ALOFT DEPARTS THROUGH THE CANADIAN MARITIMES (RESULTING
IN LIGHTER WINDS/LWRG WAVES/SEAS).

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

$$
SYNOPSIS...BMD
NEAR TERM...BMD
SHORT TERM...BMD
LONG TERM...JAB
AVIATION...AJZ/JAB
MARINE...ALB

AREA FORECAST DISCUSSION

NWS WAKEFIELD VA

423 PM EST THU FEB 14 2013

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
LOOKING AT RAP SOUNDINGS CAN SEE ENOUGH MOISTURE IN THE BOUNDARY
LAYER FOR SOME CLOUDS AND HAVE SEEN ESPECIALLY TOWARD THE COAST A
BKN LAYER CLOSE TO 3000 FEET. THIS WILL SLOWLY LIFT AND DISSIPATE
AS THE AFTERNOON GOES ON WITH MAINLY CLEAR SKIES BY EVENING. WINDS
WILL BE VARIABLE AND LIGHT. CONTINUED VFR CONDITIONS TONIGHT AND
FRIDAY.

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

$$
SYNOPSIS...BMD
NEAR TERM...BMD
SHORT TERM...BMD
LONG TERM...JAB
AVIATION...AJZ/JAB
MARINE...ALB

AREA FORECAST DISCUSSION

NWS WAKEFIELD VA

1247 PM EST THU FEB 14 2013

.SYNOPSIS...
HIGH PRESSURE RETURNS TODAY IN WAKE OF DEPARTING LOW PRESSURE. A
COLD FRONT PASSES THROUGH THE REGION LATE FRIDAY...FOLLOWED BY
UNSETTLED CONDITIONS AND A COOLER CANADIAN AIRMASS FOR THE REMAINDER
OF THE WEEKEND.

.NEAR TERM /THROUGH TONIGHT/...
LATEST WATER VAPOR IMAGERY SHOWS SEVERAL SHORTWAVES EMBEDDED IN
BROAD UPPER LEVEL TROUGH OVER THE CNTRL/ERN CONUS THIS MORNING.
SHORTWAVE/ENERGY RESPONSIBLE FOR PRECIP YESTERDAY HAS PUSHED OFF THE
NE COAST. ALSO VISIBLE IS SRN STREAM MOISTURE BEING SHUNTED TO THE
SOUTH OF THE REGION ALLOWING FOR DRYING CONDITIONS OVER THE MID
ATLANTIC. AT THE SFC...LOW PRESSURE HAS LIFTED WELL OFF THE COAST AS
HIGH PRESSURE BUILDS INTO THE SOUTHEAST. AFOREMENTIONED DRY AIR AND
HIGH PRESSURE WILL RESULT IN CLEARING SKIES TODAY. HOWEVER...LOW
STRATUS WILL PERSIST THROUGH MID MORNING...POSSIBLE LATER ACROSS THE
ERN SHORE. CALM WINDS...CLEARING SKIES AND RESIDUAL LOW LEVEL
MOISTURE WILL RESULT IN PATCHY FOG ACROSS THE PIEDMONT THROUGH MID
MORNING. OTHERWISE...SFC HIGH PRESSURE WILL CONTINUE TO BUILD OVER
THE SOUTHEAST TODAY...EXTENDING NEWD INTO THE MID ATLANTIC. LACK OF
STRONG CAA WILL ALLOW MODEST RECOVERS IN LOW LEVEL THICKNESS
VALUES...RESULTING IN SLIGHTLY ABOVE NORMAL DAYTIME TEMPS (LOW/MID
50S).

MEANWHILE...A SHORTWAVE AND ASSOCIATED SFC LOW WILL LIFT OVER THE
GREAT LAKES TONIGHT. A WEAK COLD FRONT WILL LOCATE OVER WRN VA AS AN
ARCTIC FRONT REACHES THE OH VALLEY BY EARLY FRIDAY MORNING. WILL
BEGIN TO SEE INCREASING CLOUDS ACROSS THE NW FA EARLY FRIDAY
MORNING. TEMPS WILL DROP INTO THE LOW 30S NW TO NEAR 40 SE UNDER
CLEAR/MOSTLY CLEAR SKIES AND LIGHT WINDS.

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
ADDITIONAL ENERGY WILL DIVE INTO THE UPPER MIDWEST AIDED BY A 140+
KT JET STREAK...HELPING DEEPEN THE UPPER TROUGH ACROSS THE ERN
CONUS. AFOREMENTIONED GREAT LAKES LOW WILL LIFT WELL TO THE NE AS
THE ARCTIC COLD FRONT LOCATES OVER THE OH/TN VALLEYS FRIDAY
AFTERNOON. THEREAFTER...TIMING AND SPATIAL DIFFERENCES IN LATEST
MODEL GUIDANCE WILL RESULT IN A BELOW CONFIDENCE FORECAST
BEGINNING FRIDAY NIGHT WITH FRONTAL PASSAGE AND CYCLOGENESIS ALONG
THE MID ATLANTIC COAST. TRENDED FORECAST TOWARD A GFS/ECMWF BLEND
AS NAM GUIDANCE SEEMS UNREALISTIC WITH DEVELOPING A SFC LOW TOO
FAR INLAND. THUS...COLD FRONT IS FORECAST TO CROSS THE REGION LATE
FRIDAY AS A BROAD LONGWAVE TROUGH SETTLES OVER THE ERN CONUS. WAVE
OF LOW PRESSURE WILL LIFT ALONG A COASTAL BOUNDARY FRIDAY
NIGHT...DEVELOPING INTO A COASTAL LOW OFF THE MID ATLANTIC COAST
SATURDAY MORNING AS A STRONG PV ANOMALY AND THE DEEP UPPER TROUGH
APPROACH. STRONG FRONTOGENETIC FORCING ALONG THE ARCTIC FRONT
WILL LOCATE OVER THE NW FA LATE FRIDAY NIGHT. MOISTURE WILL BE
SOMEWHAT LIMITED WITH PRECIP WATERS AOB HALF AN INCH.
HOWEVER...HIGH MODEL RH AND OMEGA AT -10C AS WELL AS GOOD DYNAMICS
(PROVIDED BY SHORTWAVE AND LOW LEVEL FRONTOGENETIC FORCING) WILL BE
ENOUGH FOR PRECIP ACROSS FA THROUGH SATURDAY MORNING. HAVE
INTRODUCED CHANCE POPS ACROSS THE PIEDMONT THROUGH THE NRN FA AND
THE ERN SHORE SATURDAY MORNING. MAIN FORECAST CHALLENGE WILL BE
TIMING OF COLD CANADIAN AIR LATE FRIDAY NIGHT/EARLY SATURDAY
MORNING. TEMPERATURE PROFILES SUGGEST ACCUMULATING SNOW OVER MUCH OF
THE PIEDMONT EARLY SATURDAY MORNING AND OVER THE NRN FA BY SUNRISE.
TEMPS WILL WARM ABOVE FREEZING SHORTLY AFTER SUNRISE TO CHANGE ALL
PRECIP OVER TO RAIN. HAVE PLACED LIGHT ACCUMULATIONS (LESS THAN
HALF AN INCH) OVER PORTIONS OF THE PIEDMONT SATURDAY MORNING. WILL
LIKELY HAVE TO ADD ADDITIONAL LIGHT ACCUMULATIONS FURTHER EAST AND
NORTH...BUT WILL WAIT FOR BETTER MODEL CONSENSUS. TEMPS FRIDAY
AFTERNOON WILL RANGE FROM THE MID/UPPER 50S TO NEAR 60 ALONG THE
COAST...SO GROUND TEMPS WILL LIMIT AMOUNT OF ACCUMULATIONS.

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
FOLLOWING HPC GUIDANCE FOR MOST OF THE PERIOD. THE ECMWF AND GFS
NOW SIMILAR WITH FRONT COMING THROUGH SATURDAY NIGHT. THERE IS NOW
MORE CONSENSUS IN NOT PHASING THE UPPER SYSTEM UNTIL IT IS
OFFSHORE WHICH SHOULD KEEP THE DEVELOPMENT AWAY FROM OUR AREA.
COULD STILL HAVE SOME LIGHT PRECIPITATION WITH THE STRONG FRONT AS
IT MOVES ACROSS THE AREA SATURDAY NIGHT. LOOKING AT TEMPERATURE
PROFILES...IT IS POSSIBLE THAT SOME SNOW COULD MIX WITH THE RAIN
SHOWERS AS IT PASSES THROUGH. NOT EXPECTING MANY SHOWERS AND ALL
PRECIPITATION SHOULD BE LIGHT. BY SUNDAY HIGH PRESSURE IS BUILDING
OVER THE AREA AND TEMPERATURES WILL PLUNGE WITH HIGHS MAINLY
AROUND 40. FOLLOWED HPC AND MOSGUIDE FOR TEMPERATURES AS THEY ARE
SIMILAR. NEXT UPPER TROF BEGINS TO APPROACH ON TUESDAY AND PUSHES
ANOTHER FRONT ACROSS THE AREA TUESDAY AND TUESDAY NIGHT. THERE
WILL BE ENOUGH WARM UP AHEAD OF THIS FRONT THAT ALL PRECIPITATION
SHOULD BE RAIN. HIGH TEMPERATURES WILL BE BACK INTO THE 50S.
ANOTHER COOL DOWN TO SLIGHTLY BELOW NORMAL TEMPERATURES WILL OCCUR
ON WEDNESDAY.

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
LOOKING AT RAP SOUNDINGS CAN SEE ENOUGH MOISTURE IN THE BOUNDARY
LAYER FOR SOME CLOUDS AND HAVE SEEN ESPECIALLY TOWARD THE COAST A
BKN LAYER CLOSE TO 3000 FEET. THIS WILL SLOWLY LIFT AND DISSIPATE
AS THE AFTERNOON GOES ON WITH MAINLY CLEAR SKIES BY EVENING. WINDS
WILL BE VARIABLE AND LIGHT. CONTINUED VFR CONDITIONS TONIGHT AND
FRIDAY.

.MARINE...
ALL SCA FLAGS ARE NOW EXPIRED.

HIGH PRESSURE BUILDS ACROSS THE AREA TODAY AND REMAINS OFF THE
SOUTHEAST COAST THROUGH FRIDAY. LOW PRESSURE TRACKS N OF THE SAINT
LAWRENCE VALLEY THURSDAY NIGHT AND FRIDAY DRAGGING A STRONG COLD
FRONT TOWARD THE REGION FRIDAY AFTERNOON...AND ACROSS THE MID
ATLANTIC COAST LATE FRIDAY NIGHT INTO SATURDAY MORNING. SECONDARY
LOW PRESSURE DEVELOPMENT IS EXPECTED ALONG THE BOUNDARY AS IT
CROSSES THE AREA AND THIS WILL DELAY THE STRONGEST CAA UNTIL LATER
SATURDAY. INCREASED WIND SPEEDS (TO SCA OUT OF THE NW) ARE EXPECTED
ALONG WITH BUILDING WAVES/SEAS SATURDAY NIGHT INTO SUNDAY. SURFACE
HIGH PRESSURE RETURNS MONDAY RESULTING IN LIGHTER WIND AND SUBSIDING
WAVES/SEAS.

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

$$
SYNOPSIS...SAM/TMG
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...JAB
AVIATION...AJZ/JAB
MARINE...AJZ

AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

1228 PM EST THU FEB 14 2013

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
ALTHOUGH HIGH PRESSURE RIDGE IS MOVING INTO THE REGION...IFR STRATUS
REMAINS DRAPED ACROSS THE PORTS THIS AFTERNOON. LOW LEVEL MOISTURE
IS TRAPPED AT THE SURFACE...BUT SOME HEATING THIS AFTERNOON SHOULD
BRING CEILINGS BACK ABOVE 1000 FEET. A RAPIDLY MOVING COLD FRONT
PUSHING ACROSS THE GREAT LAKES TONIGHT WILL SHIFT WINDS FROM THE
SOUTH TO THE WEST AND PROVIDE A FEW GUSTS TO 20 KNOTS OVERNIGHT. THE
MVFR STRATOCU WITH AND BEHIND THE FRONT WILL PERSIST INTO FRIDAY. LITTLE
PRECIPITATION IS EXPECTED WITH THE FRONT BUT HAVE INCLUDED SOME
FLURRIES AT THE NORTHERN PORTS.

.OUTLOOK.../FRIDAY THROUGH MONDAY/...
PERIODIC RESTRICTIONS ARE PSBL THRU SUN AS SVRL FAST MOVG
DISTURBANCES MOVE THRU THE GT LKS RGN. HI PRES AND VFR CONDS RETURN
MON.

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

AREA FORECAST DISCUSSION

NWS DETROIT/PONTIAC MI

359 PM EST THU FEB 14 2013

.SHORT TERM...THIS EVENING AND TONIGHT

THE VORTICITY RICH POTENTIAL VORTICITY ANOMALY NOW SPINNING ACROSS
CENTRAL LAKE MICHIGAN HAS LED TO A NUMBER OF SPOKES/BANDS OF
PRECIPITATION SLIDING THROUGH LOWER MICHIGAN. SINCE MIDDAY THESE
BANDS HAVE BEEN NOTHING MORE THAN LIGHT RAIN SHOWERS OR SPRINKLES
PER SFC REPORTS AND A NEAR SURFACE MELTING LAYER AT GREATER THAN 4C.
VARIOUS HIRES MODELS ARE SUGGESTING THAT CONVECTION/SHOWER
DEVELOPMENT WILL TAKE PLACE ALONG AND AHEAD OF THE COLD FRONT
BETWEEN 21-00Z. THIS IDEA REMAINS VALID. DIFFICULT TO EVALUATE THE
OVERALL THERMODYNAMIC PROFILE OR HOW MUCH CAPE IS OUT THERE WITH THE
VALID RUC BASED SPC MESOANALYSIS GRAPHIC SHOWING NOTHING IN THE WAY
OF MUCAPE. GOING THROUGH MODEL DATA THOUGH SUGGESTS THAT 50 TO 100
J/KG IS PLAUSIBLE GIVEN SFC/DWPT VALUES THAT ARE ON TARGET.
EVOLUTION OF MODEL SOUNDINGS SUGGESTS THAT IT WILL REQUIRE SOME
COOLING FROM APPROACHING COLD FRONT TO ERODE A LOW CAPPING LAYER TO
ALLOW FOR INITIATION. THE POTENTIAL EXISTS FOR CONVECTION TO YIELD
GRAUPEL/ICE PELLETS. ADDITIONALLY...THERE REMAINS A POSSIBILITY THAT
BURSTS COULD PRODUCE MORE IN THE WAY OF SNOW...AND THE PERCENTAGE OF
OCCURRENCE IS AN UNKNOWN. FARTHER NORTH...EXPECTING THE ACTIVITY TO
FALL AS RAIN...ALTHOUGH THIS AREAS STANDS A BETTER CHANCE TO SEE
SOME LIGHT SNOW WITH MINOR ACCUMULATIONS. WINDS WILL INCREASE...UP
TO 25 TO 30 MPH...AS WIND DIRECTIONS SHIFT FROM 200 TO 240 POST COLD
FRONT.

ISENTROPIC DOWNGLIDE WILL COMMENCE BETWEEN 00-03Z...KICKING IT UP A
COUPLE OF GEARS BETWEEN 03-09Z. THE COLUMN IS SHOWN TO BECOME QUITE
STABLE IN THE 900-700MB LAYER...TOO STABLE TO SUPPORT MUCH IN THE
WAY OF SNOW TONIGHT. NAM IS HIGHLIGHTING SOME LAKE EFFECT
BANDING/ENHANCED CONVERGENCE ACROSS SW LOWER LATE TONIGHT. DID LEAVE
A LOW CHANCE FOR LIGHT IN ACROSS THE SOUTH AS THERE IS SOME
POTENTIAL FOR SOME SNOWFLAKES TO MAKE THE TRIP ACROSS THE PENINSULA.
OTHERWISE...FLURRIES FOR A MAJORITY OF THE AREA. LOWS TONIGHT WERE
DERIVED FROM A BLEND OF RAW MODEL OUTPUT...A DECENT ADJUSTMENT
DOWNWARD UPPER TEENS NORTH TO UPPER 20S SOUTH.

.LONG TERM...FRIDAY THROUGH NEXT THURSDAY

LONGWAVE TROUGH WILL LOCK COOL AIR IN PLACE OVER THE GREAT LAKES
THROUGH THE WEEKEND...AS H850 TEMPS DROP TO AROUND -18C (BY SAT
NIGHT) IN THE POST-FRONTAL AIRMASS. CHANCES FOR ACCUMULATING SNOW
LOOK FAIRLY LOW FOR THIS SIDE OF THE STATE...AND WILL BE DUE TO A
COMBINATION OF WEAK SHORTWAVES AND LAKE EFFECT. SHORTWAVES MAY BE A
LITTLE HARD TO TIME DUE TO SMALL NATURE AND LACK OF SAMPLING (AT
THIS TIME) AND FORECAST ADJUSTMENTS ARE STILL POSSIBLE AS CHANGES IN
TIMING/LOCATION OF SHORTWAVES IMPACT LAKE EFFECT PARAMETERS SUCH AS
STABILITY...MOISTURE...AND WIND SPEED AND TRAJECTORY.

MODEL GUIDANCE TAKES THE WAVE NOW DROPPING THROUGH SOUTHERN MANITOBA
ACROSS NORTHERN LOWER MICHIGAN TOMORROW...WHILE ALSO SHEARING APART
ANOTHER SHORTWAVE AS IT DROPS FROM THE DAKOTAS DOWN INTO THE OHIO
VALLEY. VERY WEAK LIFT ASSOCIATED WITH THESE WAVES COULD PROVIDE A
BRIEF SNOW SHOWER TO THE AREA...BUT MAINLY EXPECT A LOT OF CLOUDS
AND FLURRIES AROUND DUE TO LAKE EFFECT AND STEEP LAPSE RATES. DID
KEEP LOW POPS IN THE FORECAST...BUT THINK FAIRLY WEAK FLOW OVER THE
LAKE AND ONLY MODERATE INSTABILITY SHOULD KEEP ACCUMULATIONS TO OUR
WEST. SIMILAR POP FORECAST EXISTS ON FRIDAY NIGHT. ALTHOUGH MOISTURE
DEPTH AND COLD AIR ADVECTION WILL INCREASE...MEAN SURFACE-850MB FLOW
ACROSS LAKE MICHIGAN WILL ONLY RUN 10-15 KNOTS...AND WILL TURN A
LITTLE MORE TO THE NORTHWEST. AGAIN WOULD EXPECT MOSTLY
FLURRIES...AND ONLY LOW CHANCES FOR LIGHT ACCUMULATIONS SOUTH OF A
LINE FROM HOWELL TO DETROIT.

POTENTIAL FOR LIGHT SNOW LOOKS A LITTLE BETTER ON SATURDAY AS A
SHORTWAVE TROUGH AXIS CLIPS ACROSS THE AREA. LAKE EFFECT ENHANCEMENT
ALSO LOOKS MORE LIKELY AS EQUILIBRIUM HEIGHTS OVER LAKE
MICHIGAN HIT THEIR PEAK AROUND 12KFT AND LAKE TO H850 DELTA T VALUES
RISE TO OVER 20 C. LIMITING FACTORS FOR THIS SIDE OF THE STATE ONCE
AGAIN WILL BE LIGHT FLOW AND WINDS TURNING MORE TO THE
NORTH-NORTHWEST. WOULD EXPECT FLURRIES AND SCATTERED LIGHT SNOW
SHOWERS ACROSS THE AREA IN THIS SET-UP...WITH BETTER POTENTIAL
(HIGHER POPS) SOUTH OF M-59 WHERE CONVERGENCE SHOULD BE BETTER.

LONGWAVE TROUGH WILL PUSH TO THE EAST COAST DURING THE SECOND HALF
OF THE WEEKEND...ALLOWING AN UPSTREAM RIDGE TO SLIDE IN OVERHEAD
SUNDAY INTO MONDAY. ENERGY DIVING OUT OF THE GULF OF ALASKA WILL
DROP THROUGH THE CENTRAL ROCKIES MONDAY...PULLING ADDITIONAL ENERGY
OUT OF THE SOUTHERN STREAM BEFORE IT BECOMES MORE ORGANIZED AND
DEEPENS OVER THE GREAT LAKES MONDAY NIGHT AND TUESDAY (AIDED BY GOOD
HEIGHT FALLS AND STRONG JET DYNAMICS). TRENDS WITH THE EURO AND GFS
HAVE BEEN TO SHIFT THIS SYSTEM FURTHER NORTH OVER THE PAST 24
HOURS...WITH A SURFACE LOW CENTER TRACK MORE ACROSS CENTRAL OR
NORTHERN MICHIGAN. GIVEN THAT THE GEM AND UKMET ARE STILL FURTHER
SOUTH WITH THE TRACK...MADE JUST MINOR ADJUSTMENTS TO PRECIPITATION
TYPE THIS FORECAST CYCLE TO INCREASE RAIN POTENTIAL. 14.12Z EURO/GFS
SOLUTIONS NOW SUPPORT ALL RAIN MONDAY NIGHT BEFORE A CHANGEOVER TO
SNOW BEHIND A STRONG COLD FRONT ON TUESDAY. ACCUMULATIONS STILL LOOK
POSSIBLE...BUT MAY BE DELAYED UNTIL TUESDAY.

.MARINE...

LOW PRESSURE WILL TRACK THROUGH LOWER MICHIGAN THIS AFTERNOON AND
ACROSS NORTHERN LAKE HURON THIS EVENING. CURRENT SURFACE
OBSERVATIONS IN THE INCREASED GRADIENT PORTION OF THE SURFACE LOW IS
SUPPORTING WIND GUSTS OF UP TO 30 KNOTS. WITH NO EXPECTED
DEEPENING/ACTUAL MIDLEVEL WEAKENING RATES WILL CANCEL THE GALE WATCH
AND FORGO A GALE WARNING. THIS IS ALSO SUPPORTED BY THE VERY BRIEF
DURATION TIME. HOWEVER...WITH THE COLD NORTHWEST FLOW FOLLOWING THE
CYCLONE...DID ISSUE A BRISK WIND ADVISORY FOR ALL NEARSHORE ZONES.

WINDS WILL WEAKEN ON FRIDAY AS ARCTIC HIGH PRESSURE BUILDS INTO THE
WESTERN GREAT LAKES REGION. THIS HIGH WILL KEEP RELATIVELY LIGHT
WINDS ON THE LAKES THROUGH THE WEEKEND. A LOW PRESSURE SYSTEM IS
FORECAST TO INTENSIFY OVER THE GREAT LAKES REGION MONDAY NIGHT INTO
TUESDAY AND WILL OFFER THE NEXT CHANCE FOR STRONG WINDS.

.AVIATION...ISSUED 104 PM EST THU FEB 14 2013

//DISCUSSION...

THE CLOSED MIDLEVEL LOW CIRCULATION NOW ROUNDING INTO MID LOWER
MICHIGAN WILL PUSH INITIAL PRECIPITATION ACTIVITY EAST OF THE AREA.
IN FACT...ALL TERMINALS ARE CURRENTLY REPORTING NO PRECIPITATION.
OUTSIDE OF A COUPLE ROGUE SPRINKLES...EXPECT DRY CONDITIONS FOR THE
NEXT 3 HOURS. THE NEXT FEATURE TO MONITOR WILL BE AN ATTENDANT COLD
FRONT THAT WILL SWING THROUGH SOUTHEASTERN MICHIGAN BETWEEN 21-00Z.
FORCING ALONG AND AHEAD OF THE COLD FRONT IS EXPECTED TO ACT ON
INCREASING LOWER ATMOSPHERIC INSTABILITY TO CAUSE SHOWERS/CONVECTION
TO INITIATE OVERHEAD. PRECIPITATION RATES WITHIN THE CONVECTION COULD
YIELD GRAUPEL OR ICE PELLETS. SOME QUESTION AS TO HOW WARM THE NEAR
SURFACE LAYER WILL GET...WHICH BRINGS SOME PRECIPITATION TYPE
CONCERNS. KEPT A SNOW MENTION IN WITH CONVECTIVE RAIN/PL AT
KFNT...WHILE MAINTAINED AN ALL SNOW MENTION AT KMBS. THE STRENGTH OF
THE COLD AIR ADVECTION MAY SUPPORT A GOOD WESTERLY POP OF WIND POST
COLD FRONT...POTENTIALLY UP TO 30 KNOTS.

FOR DTW...CONFIDENCE HAS INCREASED THAT CONVECTIVE RAIN SHOWERS WILL
DEVELOP ALONG AN APPROACHING COLD FRONT. THIS IS EXPECTED TO OCCUR
BETWEEN 21-00Z. GRAUPEL OR PL WILL BE POSSIBLE IN THE HEAVIEST
CONVECTIVE CELLS. AFTER THE COLD FRONT...CONDITIONS WILL QUIET DOWN
THIS EVENING BEFORE LIGHT SNOW SHOWERS/FLURRIES BECOME POSSIBLE
AGAIN AFTER 7Z.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILING HEIGHTS BELOW 5000 FEET THROUGHOUT MUCH
IF NOT ALL OF THE TAF PERIOD.

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
BRISK WIND ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
HURON INCLUDING SAGINAW BAY...FROM 7 PM THURSDAY TO 10 AM
FRIDAY.

LAKE ST CLAIR...
BRISK WIND ADVISORY...UNTIL 4 AM FRIDAY.

MI WATERS OF LAKE ERIE...
BRISK WIND ADVISORY...UNTIL 4 AM FRIDAY.

SHORT TERM...CB
LONG TERM....HLO
MARINE.......CB
AVIATION.....CB

YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).

AREA FORECAST DISCUSSION

NWS MARQUETTE MI

1243 PM EST THU FEB 14 2013

.UPDATE...
ISSUED AT 947 AM EST THU FEB 14 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 448 AM EST THU FEB 14 2013

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 448 AM EST THU FEB 14 2013

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1242 PM EST THU FEB 14 2013

AN INITIAL BURST OF LAKE-ENHANCED SNOW ON THE BACKSIDE OF A
DEPARTING CLIPPER SYSTEM IS RESULTING IN CIGS AND VIS ON THE
LIFR/IFR THRESHOLD AT ALL SITES. EXPECT VIS TO IMPROVE AND -SHSN TO
DIMINISH THIS AFTERNOON AS MOISTURE FROM THE SYSTEM PULLS OUT OF THE
AREA. THEN LATE TONIGHT...LES INTENSITY WILL INCREASE AT MAINLY IWD
AND CMX AS WNW TO NW WINDS BRING ARCTIC AIR OVER LAKE SUPERIOR. VIS
WILL FALL TO NEAR LIFR LEVELS...AND WILL LIKELY DROP LOWER AT TIMES
UNDER HEAVIER LES BANDS ON FRIDAY. IWD HAS THE BIGGEST QUESTION MARK
AS IT LOOKS LIKE A SIGNIFICANT LES BAND WILL SET UP JUST NORTH OF
THE TERMINAL. IF THIS BAND DRIFTS SOUTH AT TIMES FRIDAY
MORNING...VIS COULD FALL BELOW AIRFIELD LANDING MINS FOR AN EXTENDED
PERIOD.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EST THU FEB 14 2013

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM FRIDAY MORNING THROUGH SATURDAY
AFTERNOON FOR MIZ006-085.

WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MIZ012.

LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 AM EST
SATURDAY FOR LSZ264>266.

LAKE MICHIGAN...
NONE.
&&

UPDATE...TK
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...TK
MARINE...SRF

AREA FORECAST DISCUSSION

NWS ST LOUIS MO

334 PM CST THU FEB 14 2013

.SHORT TERM...
ISSUED AT 333 PM CST THU FEB 14 2013
(TONIGHT)

SECONDARY COLD FRONT IS EXPECTED TO MOVE THROUGH THE CWFA BY AROUND MIDNIGHT.
ALOFT...A FAIRLY STRONG 500-HPA SHORTWAVE TROUGH WILL PROVIDE FORCING FOR
ASCENT AND HELP TO PRODUCE SOME LIGHT PRECIPITATION FOR CENTRAL AND NORTHERN
SECTIONS OF THE AREA. NWP GUIDANCE HAVE NOT EXACTLY BEEN CONSISTENT WITH
PLACEMENT OF QPF AXIS...INCLUDING HI-RES SHORT-TERM MODELS SUCH AS THE
RAP/HRRR. THEREFORE...HAVE ELECTED TO KEEP CHANCE POPS IN AREAS WHERE BEST
MID/UPPER LEVEL FORCING WILL BE LOCATED. OVERALL...STILL LOOKS LIKE A LIGHT
QPF EVENT WITH A RAIN/SNOW MIX INITIALLY CHANGING OVER TO SNOW AS THE BOUNDARY
LAYER COOLS SUFFICIENTLY. ACCUMULATIONS OF SNOWFALL ARE LIKELY TO BE ON THE
ORDER OF A DUSTING TO A QUARTER OF AN INCH...THOUGH THESE NW FLOW "SYSTEMS"
THIS WINTER HAVE NOT EXACTLY BEEN WELL BEHAVED.

GOSSELIN

.LONG TERM...
ISSUED AT 333 PM CST THU FEB 14 2013
(FRIDAY THROUGH SUNDAY)

THE TAIL END OF THE SHORTWAVE SHOULD BE THROUGH MOST OF THE AREA BY
18Z THURSDAY. WILL KEEP SCATTERED FLURRIES GOING THROUGH THE
MORNING HOURS UNTIL THE LAST OF THE ENERGY CLEARS THE AREA.
CERTAINLY NOT EXPECTING ANY ADDITIONAL ACCUMULATION AS WE WILL BE
WELL INTO COLD/DRY ADVECTION THROUGH THE LOWEST 10,000FT OF THE
ATMOSPHERE AFTER 12Z. A COLD DRY AIRMASS DROPS ACROSS THE AREA AS
ANOTHER SHORTWAVE DIPS DOWN THE BACKSIDE OF THE OVERALL
TROF...DIGGING AND AMPLIFYING THE LONGWAVE INTO THE LOWER
MISSISSIPPI VALLEY ON SATURDAY. NAM KICKS OUT SOME LIGHT QPF
LATE FRIDAY NIGHT/EARLY SATURDAY MORNING AS THE SHORTWAVE RIPPLES
BY...BUT THE GFS IS DRY AND THE LOCAL WRF MODEL KEEPS THE PRECIP OUT
OF OUR AREA SO HAVE KEPT FORECAST DRY AT THIS TIME. THE AMPLIFIED
LONGWAVE MOVES EAST SATURDAY NIGHT ALLOWING UPPER LEVEL RIDGING AND
WARMER TEMPERATURES TO BUILD BACK INTO MISSOURI AND ILLINOIS ON
SUNDAY. MOS GUIDANCE LOOKS VERY REASONABLE THROUGH THE PERIOD...SO
HAVE USED A BLEND OF THE PREVIOUS FORECAST AND MOS FOR TEMPERATURES
THROUGH SUNDAY.

(MONDAY THROUGH THURSDAY)

ANOTHER LONGWAVE TROF DEEPENS ACROSS THE ROCKY MOUNTAINS SUNDAY
NIGHT INTO MONDAY. THIS WILL FORCE LEE-SIDE CYCLOGENESIS
MONDAY...BUT JUST AS THE UPPER SYSTEM ISN`T A TIGHTLY COMPACTED
SHORTWAVE...THE SURFACE SYSTEM WILL LIKEWISE BE AN ELONGATED TROF
STRETCHING FROM SOUTHERN ONTARIO ALL THE WAY TO TEXAS. PLENTY OF
MOISTURE CONVERGENCE IN THE WARM ADVECTION AHEAD OF THE TROF MONDAY
SO HAVE INCREASED POPS TO LIKELY. AS THE SYSTEM WINDS UP OVER THE
GREAT LAKES ON MONDAY NIGHT AND COLD ADVECTION REALLY RAMPS UP OVER
THE AREA...THE RAIN MAY END AS A LITTLE LIGHT SNOW.

TUESDAY AND WEDNESDAY LOOK PRETTY TRANQUIL AHEAD OF THE NEXT SYSTEM
WITH SEASONABLY COOL TEMPERATURES...BUT THURSDAY LOOKS PRETTY
INTERESTING. MEDIUM RANGE GUIDANCE IS REMARKABLY SIMILAR ON
THURSDAY WITH A VERY STRONG SHORTWAVE MOVING OFF THE
ROCKIES...GENERATING A CLOSED LOW THROUGH MOST OF THE DEPTH OF THE
TROPOSPHERE. BOTH THE GFS AND ECMWF HAVE THE SURFACE LOW GENERALLY
BETWEEN WICHITA AND TOPEKA...WHICH IS PRETTY DARN GOOD AGREEMENT
THIS FAR OUT. RIGHT NOW...THE MOST LIKELY PRECIPITATION TYPE ACROSS
THE AREA LOOKS LIKE A WET SLOPPY RAIN/SNOW MIX AS WE`LL BE ON THE
NORTHEAST SIDE OF THE STORM...STILL IN THE COLD SECTOR. HOWEVER
THIS COULD...AND LIKELY WILL CHANGE ABOUT A DOZEN TIMES BETWEEN NOW
AND THEN.

CARNEY

.AVIATION...
ISSUED AT 1138 AM CST THU FEB 14 2013

VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THIS AFTERNOON AS
UPPER-LEVEL IMPULSE RESPONSIBLE FOR BRINGING COLD FRONT THROUGH
THE REGION EARLIER THIS MORNING STAYS FAR ENOUGH NORTH/NORTHEAST
TO HAVE ALMOST NO IMPACT OTHER THAN WIND SHIFT TO THE WEST-
NORTHWEST. DROPPED GUSTS AT TAF SITES WITH EXCEPTION OF KUIN AS
HIGHER WINDS ALOFT WEAKEN WITH TIME. UPSTREAM OBSERVATIONS ALSO
SUPPORT A BIT WEAKER WINDS AND WIND GUSTS THAN PREVIOUSLY THOUGHT. MID/HIGH
LEVEL CLOUDINESS WILL STREAM IN THIS AFTERNOON FROM WEST TO EAST
IN WNW FLOW ALOFT. MVFR CEILINGS ARE FORECAST TO MOVE
SOUTHEASTWARD WITH TIME AND AFFECT TAF SITES OVERNIGHT AS A SECOND
UPPER-LEVEL IMPULSE BRINGS A REINFORCING SHOT OF COLDER AIR ALONG
WITH A CHANCE OF LIGHT SNOW. BEST CHANCES OF LIGHT SNOW ATTM LOOK
TO BE ORIENTED WEST- EAST ORIENTED NEAR INTERSTATE 70. THIS
SCENARIO IS SUPPORTED BY LAST FEW RUNS OF RAP GUIDANCE WHICH HAS
PERFORMED QUITE WELL THIS WINTER...INCLUDING THE FEB. 2 SURPRISE
SNOW WHICH CAME BENEATH NW FLOW ALOFT AS WELL. LOW CLOUDINESS WILL
SCATTER OUT BY TOMORROW MORNING WITH WINDS VEERING TO THE
NORTHWEST WITH SPEEDS BETWEEN 10 AND 15 MPH.

SPECIFICS FOR KSTL...

VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THIS AFTERNOON AS
UPPER-LEVEL IMPULSE RESPONSIBLE FOR BRINGING COLD FRONT THROUGH
THE REGION EARLIER THIS MORNING STAYS FAR ENOUGH NORTH/NORTHEAST
TO HAVE NO IMPACT OTHER THAN WIND SHIFT TO THE WEST-NORTHWEST.
DROPPED GUSTS AT LAMBERT AS HIGHER WINDS FROM ALOFT WEAKEN WITH
TIME. UPSTREAM OBSERVATIONS ALSO SUPPORT A BIT WEAKER WINDS AND
WIND GUSTS THAN PREVIOUSLY THOUGHT. MID/HIGH LEVEL CLOUDINESS WILL
STREAM IN THIS AFTERNOON FROM WEST TO EAST IN WNW FLOW ALOFT. MVFR
CEILINGS ARE FORECAST TO MOVE SOUTHEASTWARD WITH TIME AND AFFECT
TAF SITES OVERNIGHT AS A SECOND UPPER-LEVEL IMPULSE BRINGS A
REINFORCING SHOT OF COLDER AIR ALONG WITH A CHANCE OF LIGHT SNOW.
BEST CHANCES OF LIGHT SNOW ATTM LOOK TO BE ORIENTED WEST-EAST
ORIENTED NEAR INTERSTATE 70. THIS SCENARIO IS SUPPORTED BY LAST
FEW RUNS OF RAP GUIDANCE WHICH HAS PERFORMED QUITE WELL THIS
WINTER...INCLUDING THE FEB. 2 SURPRISE SNOW WHICH CAME BENEATH NW
FLOW ALOFT AS WELL. LOW CLOUDINESS WILL SCATTER OUT BY TOMORROW
MORNING WITH WINDS VEERING TO THE NORTHWEST WITH SPEEDS BETWEEN 10
AND 15 MPH.

GOSSELIN

.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS 30 37 22 34 / 30 10 10 5
QUINCY 24 33 17 31 / 30 10 10 5
COLUMBIA 28 37 19 35 / 20 10 10 5
JEFFERSON CITY 29 37 20 35 / 20 10 10 5
SALEM 32 36 21 32 / 30 10 10 5
FARMINGTON 31 39 20 36 / 20 10 10 5

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

WFO LSX

AREA FORECAST DISCUSSION...UPDATED AVIATION

NWS ST LOUIS MO

1147 AM CST THU FEB 14 2013

.SHORT TERM...
ISSUED AT 320 AM CST THU FEB 14 2013
(TODAY)

FIRST IN A SERIES OF COLD FRONTS TO SLIDE THROUGH FORECAST AREA THIS
MORNING WITH SOUTHWEST WINDS VEERING TO THE WEST AND PICKING UP. NOT
A LOT OF CAA WITH THIS INITIAL FRONTAL BOUNDARY AND WITH DECENT
MIXING TO 850 MB...SO SHOULD STILL SEE TEMPS WARM UP TODAY INTO THE
UPPER 40S TO MID 50S. AS FOR THE WINDS...TO INCREASE TO 10 TO 20 MPH
WITH GUSTS NEAR 30 MPH AT TIMES THIS AFTERNOON...ESPECIALLY OVER
NORTHERN PORTIONS OF FORECAST AREA.

BYRD

.LONG TERM...
ISSUED AT 320 AM CST THU FEB 14 2013
(TONIGHT-SUNDAY)

BEEN STRUGGLING ON WHAT TO DO WITH PRECIP POTENTIAL TONIGHT AS
SECONDARY SHORTWAVE DROPS S AND DEEPENS TROF OVER THE CENTRAL U.S.
00Z NAM AND ASSOCIATED OUTPUT SUGGESTS VORT MAX WILL STAY RATHER
WELL-DEFINED AS IT DIVES SE ACROSS THE AREA TONIGHT GENERATING LIGHT
QPF OVER MOST OF THE REGION AND SUGGESTING SOME VERY MINOR SNOW
ACCUMULATIONS. MEANWHILE...WHILE OTHER SOLUTIONS TEND TO FORECAST
MORE OF A BROAD TROF...AND LESSER QPF...SWEEPING ACROSS THE AREA.
NOT CERTAIN WHICH TREND IS MORE CORRECT...BUT AM A LITTLE
CONCERNED THAT ALL SHORT RANGE SOLUTIONS DO INDICATE MID LEVEL
LAPSE RATES GETTING FAIRLY STEEP OVERNIGHT. HAVE DECIDED TO ADD
CHANCE POPS FOR MUCH OF THE AREA...SLOWLY SPREADING FROM N TO S
DURING THE OVERNIGHT HOURS. GIVEN FORECAST SOUNDINGS IT CERTAINLY
POSSIBLE THAT ANY PRECIP WOULD START AS A BIT OF LIGHT RAIN...BUT
IF THERE IS ANY INTENSITY TO THE PRECIP THINK EVAP COOLING WILL
QUICKLY COOL LOW LEVELS ENOUGH TO CHANGE THE RAIN TO SNOW.

THE LEADING EDGE OF THE TRULY COLD AIR WILL ARRIVE LATER
TONIGHT...AND DUE TO ITS LATE ARRIVAL MINS MAY STILL NOT BE TOO
TERRIBLY COLD. HOWEVER...THE TEMPERATURE REBOUND ON FRIDAY SHOULD
NOT BE MORE THAN 10 DEGREES DUE TO THE INTENSITY OF THE COLD
AIR ADVECTION...EVEN WITH A FAIR AMOUNT OF AFTERNOON SUNSHINE.

THE CAA IS FORECAST TO CONTINUE INTO THE START OF THE WEEKEND...AND A
REINFORCING SHOT OF COLD AIR SHOULD ARRIVE FRIDAY NIGHT/SATURDAY
MORNING AS A THIRD SHORTWAVE DIVES INTO THE AREA. WILL HAVE TO
KEEP AN EYE ON THE PRECIP POTENTIAL WITH THIS FEATURE AS THE
TRICKY N/NW FLOW PERSISTS OVER THE CENTRAL CONUS...BUT RIGHT NOW
IT APPEARS MAIN DYNAMICS WOULD BE IMPACTING AREAS WEST OF OUR CWA.
LOWEST TEMPERATURES OF THIS COLD SNAP SHOULD BE ON SATURDAY...WITH
MORNING LOWS IN THE TEENS AND LOWER 20S AND HIGHS IN THE 30-35
DEGREE RANGE.

00Z RUNS CONTINUE TO SUPPORT IDEA THAT UA PATTERN WILL REMAIN QUITE
PROGRESSIVE...TAKING CENTRAL CONUS TROF TO THE EAST COAST BY SUNDAY
WHICH IN TURN WILL ALLOW A RAPID MODERATION IN TEMPERATURES OVER THE
MID MISSISSIPPI VALLEY FOR THE LAST HALF OF THE WEEKEND.
TEMPERATURES SHOULD CLIMB 15 DEGREES OR SO FROM SATURDAY`S
HIGHS...AND RANGE FROM THE MID 40S OVER OUR E IL COUNTIES TO AROUND
50 OVER MID MO.

(MONDAY-WEDNESDAY)

MODEL TO MODEL AND RUN TO RUN AGREEMENT IN BROAD-SCALE SYNOPTIC
FEATURES CONTINUES INTO THE FIRST HALF OF NEXT WEEK...WITH NEXT
STRONG TROF PUSHING ACROSS AREA MONDAY AND MONDAY EVENING WITH
FAIRLY GOOD RAIN POTENTIAL GIVEN MOISTURE ADVECTION INTO AREA AND
STRONG DYNAMICS.

ANOTHER ROUND OF BELOW NORMAL TEMPERATURES IS EXPECTED IN THE WAKE
OF THIS SYSTEM ON TUESDAY AND WEDNESDAY.

TRUETT

.AVIATION...
ISSUED AT 1138 AM CST THU FEB 14 2013

SPECIFICS FOR KSTL...

VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THIS AFTERNOON AS
UPPER-LEVEL IMPULSE RESPONSIBLE FOR BRINGING COLD FRONT THROUGH
THE REGION EARLIER THIS MORNING STAYS FAR ENOUGH NORTH/NORTHEAST
TO HAVE NO IMPACT OTHER THAN WIND SHIFT TO THE WEST-NORTHWEST.
DROPPED GUSTS AT LAMBERT AS HIGHER WINDS FROM ALOFT WEAKEN WITH
TIME. UPSTREAM OBSERVATIONS ALSO SUPPORT A BIT WEAKER WINDS AND
WIND GUSTS THAN PREVIOUSLY THOUGHT. MID/HIGH LEVEL CLOUDINESS WILL
STREAM IN THIS AFTERNOON FROM WEST TO EAST IN WNW FLOW ALOFT. MVFR
CEILINGS ARE FORECAST TO MOVE SOUTHEASTWARD WITH TIME AND AFFECT
TAF SITES OVERNIGHT AS A SECOND UPPER-LEVEL IMPULSE BRINGS A
REINFORCING SHOT OF COLDER AIR ALONG WITH A CHANCE OF LIGHT SNOW.
BEST CHANCES OF LIGHT SNOW ATTM LOOK TO BE ORIENTED WEST-EAST
ORIENTED NEAR INTERSTATE 70. THIS SCENARIO IS SUPPORTED BY LAST
FEW RUNS OF RAP GUIDANCE WHICH HAS PERFORMED QUITE WELL THIS
WINTER...INCLUDING THE FEB. 2 SURPRISE SNOW WHICH CAME BENEATH NW
FLOW ALOFT AS WELL. LOW CLOUDINESS WILL SCATTER OUT BY TOMORROW
MORNING WITH WINDS VEERING TO THE NORTHWEST WITH SPEEDS BETWEEN 10
AND 15 MPH.

GOSSELIN

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

WFO LSX

AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

1142 AM CST THU FEB 14 2013

.UPDATE...
UPDATED EARLIER TO TEMPS TO RAISE A COUPLE OF DEGREES FOR TODAY
AS TEMPS ACROSS THE NORTH STAYED WARM OVERNIGHT AND WERE ALREADY
NEAR HIGHS. DISTURBANCE WILL CONTINUE TO PUSH SOUTH FROM S DAKOTA
INTO NEBRASKA THIS AFTERNOON...WHILE ANOTHER DISTURBANCE IS
EXITING SW NEBRASKA INTO CO/KS. WITH TEMPS GENERALLY IN THE MID
30S AND COLD AIR WITH THE DISTURBANCES AND SOME WEAK
LIFT...EXPECTING MAINLY LIGHT SNOW SHOWERS OR FLURRIES. WIND
ADVISORY CONTINUES FOR THE DAY...WITH WINDS STARTING TO
INCREASE...WITH SEVERAL SITES APPROACHING ADV CRITERIA. LIKELY A
MARGINAL EVENT...BUT STILL BE WILL A WINDY AFTERNOON.

.AVIATION...
MVFR CIGS ASSOCIATED WITH A DISTURBANCE ACROSS S DAKOTA WILL
SPREAD INTO NRN NEB...AND THE KVTN TERMINAL...THIS AFTERNOON.
ALSO COULD SEE SOME LIGHT SNOW OR FLURRIES...AND WILL MENTION WITH
A TEMPO GROUP. SW NEB...AND THE KLBF TERMINAL MAY SEE SOME ISOLD
FLURRIES...HOWEVER COVERAGE DOES NOT WARRANT MENTION IN THE TAF AT
THIS TIME. WILL CONTINUE TO MONITOR RADAR AND MAY AMEND FOR A
BRIEF PERIOD OF LIGHT SNOW...ALTHOUGH DURATION SHOULD BE SHORT.
CIGS EXPECTED TO REMAIN IN THE VFR CATEGORY FOR KLBF. WINDS THIS
AFTERNOON WILL INCREASE TO 20 TO 30 KTS WITH HIGHER GUSTS. WINDS
DIMINISH THIS EVENING BECOMING LESS THAN 10KTS OVERNIGHT.
TOMORROW SOME LINGER FLURRIES/MVFR CIGS ACROSS THE AREA...HOWEVER
NOT EXPECTING THE STRONG WINDS.

.PREV DISCUSSION... /ISSUED 633 AM CST THU FEB 14 2013/

UPDATE...

DISCUSSION...
NO MAJOR CHANGES TO THIS UPDATE. 06Z NAM IS A BIT DRIER WITH QPF
AMOUNTS. SHSN CONVERAGE IS ABOUT THE SAME. LESS THAN AN INCH OF
SNOW IS EXPECTED.

PREV DISCUSSION... /ISSUED 328 AM CST THU FEB 14 2013/

DISCUSSION...

NEAR TERM...TODAY AND TONIGHT.

SHORT TERM...12Z FRIDAY THROUGH 12Z SUNDAY.

LONG TERM...12Z SUNDAY AND BEYOND.

.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ004>010-022>029-035>038-056>059-069>071-094.

UPDATE/AVIATION....MASEK

AREA FORECAST DISCUSSION

NWS HASTINGS NE

1116 AM CST THU FEB 14 2013

.AVIATION...18Z TAF. WINDS WILL INCREASE A LITTLE YET THIS
AFTERNOON AND THEN DIMINISH AS THE SUN GOES DOWN THIS EVENING.
THERE ARE SOME MID AND LOWER CLOUDS TO THE NORTHWEST THAT WILL BE
MOVING INTO THE KGRI TERMINAL AREA THIS AFTERNOON...BUT THE
CEILINGS WILL REMAIN VFR THROUGH THE PERIOD.

.PREV DISCUSSION... /ISSUED 529 AM CST THU FEB 14 2013/

LONG TERM...SUNDAY THROUGH WEDNESDAY.

THE LONG TERM WILL CONSIST OF A SERIES OF PROGRESSIVE SHORTWAVE
TROUGHS AND RIDGES OF PACIFIC ORIGIN.

TOOK MORE OF A CONSENSUS APPROACH FOR THE LONG TERM...FAVORING
ENSEMBLE MEANS.

.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ039>041-046>049-
060>064-072>077-082>087.

KS...NONE.
&&

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY

NWS RAPID CITY SD

1043 AM MST THU FEB 14 2013

.UPDATE...CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER THE
WESTERN GREAT LAKES...WITH A TIGHT PRESSURE GRADIENT IN PLACE TO
THE WEST ACROSS THE NORTHERN PLAINS. UPPER LEVEL ANALYSIS SHOWS
LOW OVER HUDSON BAY...WITH TROF ACROSS THE CENTRAL AND EASTERN
CONUS. STRONG JET FROM WESTERN CANADA THROUGH THE CENTRAL PLAINS
IS BRINGING NUMEROUS WEAK DISTURBANCES ACROSS THE REGION. CURRENT
ONE IS MOVING ACROSS THE NORTHERN HIGH PLAINS NOW. SKIES ARE
MAINLY CLOUDY ACROSS THE AREA...WITH SOME BREAKS ACROSS WESTERN
SD. KUDX RADAR SHOWING BANDS OF SNOW SHOWERS DEVELOPING PARALLEL
TO THE FLOW ACROSS FAR NORTHEASTERN WY AND WESTERN SD. THE
HEAVIEST SHOWERS CONTINUE TO BE ACROSS THE NORTHERN INTO WEST CENTRAL
BLACK HILLS...WHERE UP TO 6 INCHES HAS FALLEN IN THE FAVORED
HIGHER ELEVATIONS SINCE LATE YESTERDAY...ESPECIALLY NORTHWESTERN
PORTIONS OF THE BLACK HILLS. WINDS INCREASED AGAIN ACROSS THE
PLAINS EARLY THIS MORNING...WITH SOME GUSTS IN THE 50 TO 60 MPH
RANGE FROM 2WX TO RAP EARLIER THIS MORNING. TEMPS ARE MOSTLY IN
THE MID 20S TO LOWER 30S.

HAVE ONLY MADE MINOR CHANGES TO THE FORECAST FOR THE REST OF TODAY
AS SNOW SHOWERS CONTINUE TO DEVELOP AND TRACK SOUTHEAST ACROSS
THE AREA THROUGH THE AFTERNOON. LOW LEVEL INSTABILITY AND MOISTURE
IS SUFFICIENT FOR SCATTERED TO NUMEROUS COVERAGE OF SHOWERS FOR
MOST OF THE AREA. ADDITIONAL SNOWFALL AMOUNTS OF 1 TO 3 INCHES
ARE EXPECTED ACROSS THE NORTHERN BLACK HILLS AND BEAR LODGE
MTS...WITH THE HIGHEST AMOUNTS OVER NORTHWEST FACING SLOPES. ANY
ACCUMULATIONS ACROSS THE PLAINS WILL GENERALLY BE LESS THAN AN
INCH. SNOW SHOWERS WILL DECREASE IN COVERAGE ACROSS THE AREA LATE
THIS AFTERNOON AND EVENING AS INSTABILITY DIMINISHES. THE
COMBINATION OF SNOW SHOWERS AND WIND WILL BRIEFLY PRODUCE LOW
VISIBILITIES ACROSS THE PLAINS. THE STRONG WINDS ACROSS THE PLAINS
WILL CONTINUE INTO THE AFTERNOON...BUT START TO DIMINISH AFTER
21Z AS BEST PRESSURE RISES SHIFT EAST AND PRESSURE GRADIENT
WEAKENS. TEMPERATURES WILL REMAIN NEARLY STEADY IN MOST
AREAS...MID 20S TO MID 30S.

.AVIATION...18Z TAFS
EXPECT SCT CONVECTIVE SHSN OVER THE AREA TODAY WITH LOCALIZED IFR
CIGS/VSBYS. SHSN ACTIVITY WILL WANE SOME TONIGHT...EXCEPT OVER THE
NORTHERN BLACK HILLS.

PREV DISCUSSION... /ISSUED 349 AM MST THU FEB 14 2013/

DISCUSSION...UPPER LEVEL ANALYSIS HAS BROAD TROF OVER SOUTH
CENTRAL CANADA WITH RIDGE JUST OFF THE WEST COAST. IN
BETWEEN...FAST NORTHWEST FLOW IS PRESENT ACROSS THE NORTHERN
ROCKIES AND PLAINS WITH A 120KT JET DRIVING SEVERAL WEAK
SHORTWAVES THROUGH MONTANA INTO EASTERN WYOMING AND WESTERN SOUTH
DAKOTA. SKIES ARE MOSTLY CLOUDY WITH SOME SNOW CROSSING NORTHEAST
WYOMING AND THE BLACK HILLS AT THE MOMENT. AT THE SURFACE...LOW
PRESSURE IS LOCATED ACROSS CENTRAL NORTH DAKOTA AND EASTERN SOUTH
DAKOTA...WITH HIGH PRESSURE ACROSS THE NORTHERN AND CENTRAL
ROCKIES. TIGHT PRESSURE GRADIENT REMAINS ACROSS WESTERN SOUTH
DAKOTA...STILL PRODUCING WINDY CONDITIONS. TEMPERATURES RANGE FROM
THE 20S TO LOWER 30S.

FOR TODAY...CYCLONIC FLOW ALOFT REMAINS OVER THE AREA...WITH
SHORTWAVE ENERGY CONTINUING TO BRING SNOW TO MUCH OF THE AREA.
GREATEST CHANCES WILL BE OVER NORTHWEST SOUTH DAKOTA...AND ALSO
THE NORTHERN BLACK HILLS WHERE UPSLOPE ENHANCEMENT IS EXPECTED TO
CONTINUE. VERY GUSTY WINDS WILL CONTINUE THROUGH THE DAY AS
PRESSURE GRADIENT REMAINS TIGHT BEHIND SURFACE LOW. SURFACE LOW
SHIFTS EAST THIS AFTERNOON...ALLOWING GRADIENT TO RELAX...AND
WINDS TO SUBSIDE LATE IN THE AFTERNOON. TEMPERATURES WILL BE MUCH
COOLER TODAY AS CANADIAN HIGH PRESSURE SETTLES IN.

FOR FRIDAY...SNOW CHANCES LINGER THROUGH THE DAY...MAINLY OVER THE
WESTERN CWA...AS REGION REMAINS UNDER WEAK CYCLONIC FLOW ALOFT.
MODELS CONTINUE TO INDICATE UPSLOPE ENHANCEMENT THROUGH THE
DAY...THOUGH IT SHOULD COME TO AN END BY EVENING AS MOISTURE
DIMINISHES. TEMPERATURES WILL REMAIN BELOW AVERAGE ON FRIDAY.

ON SATURDAY...WESTERN UPPER RIDGE FINALLY PUSHES ACROSS THE
NORTHERN ROCKIES INTO THE NORTHERN PLAINS. DRY AND VERY MILD
CONDITIONS ARE EXPECTED...WITH HIGH TEMPERATURES IN THE 40S TO
LOWER 50S.

EXTENDED...THE MODELS ARE IN GOOD AGREEMENT WITH THE FORECAST FOR A
MODERATELY STRONG TROUGH CROSSING THE NORTHERN PLAINS SUNDAY NIGHT
THROUGH MONDAY NIGHT. THE SURFACE LOW IS EXPECTED TO DROP THROUGH
EASTERN NORTH DAKOTA PRODUCING A WRAP AROUND BAND OF POST FRONTAL
PRECIP OVER THE WESTERN DAKOTAS. THE NEXT SYSTEM WHICH IS FORECAST
TO CROSS THE CENTRAL PLAINS WEDNESDAY AND THURSDAY IS POSITIONED TO
DEVELOP A BROAD AREA OF UPWARD MOTION OVER THE FORECAST AREA...
ESPECIALLY THE EASTERN SLOPES OF THE BLKHLS AND SOUTH CENTRAL SOUTH
DAKOTA. THIS MIDWEEK SYSTEM IS ALSO ON A BETTER TRAJECTORY FOR
TAPPING INTO GULF MOISTURE. TEMPERATURES WILL DROP TO BELOW NORMALS
AFTER SUNDAY AND THEN CONTINUE TO COOL A FEW MORE DEGREES DURING MID
WEEK.

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR
CENTRAL BLACK HILLS-NORTHERN BLACK HILLS.

WIND ADVISORY UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR
BENNETT-BUTTE-CUSTER CO PLAINS-FALL RIVER-HAAKON-HARDING-
HERMOSA FOOT HILLS-JACKSON-MELLETTE-NORTHERN FOOT HILLS-
NORTHERN MEADE CO PLAINS-PENNINGTON CO PLAINS-PERKINS-RAPID
CITY-SHANNON-SOUTHERN FOOT HILLS-SOUTHERN MEADE CO PLAINS-
STURGIS/PIEDMONT FOOT HILLS-TODD-TRIPP-ZIEBACH.

WY...WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR
WYOMING BLACK HILLS.

SHORT TERM...26
LONG TERM....WFO UNR
AVIATION...HELGESON

AREA FORECAST DISCUSSION...CORRECTED

NWS MILWAUKEE/SULLIVAN WI

353 PM CST THU FEB 14 2013

.SHORT TERM...

.TONIGHT AND FRIDAY...FORECAST CONFIDENCE MEDIUM.

SURFACE LOW MOVES NORTHEAST FROM LAKE HURON TO SOUTHERN QUEBEC AS
HIGH PRESSURE BUILDS INTO THE NORTHERN AND CENTRAL PLAINS. DECENT
SHORTWAVE MOVING BY JUST TO OUR SOUTHWEST EARLY THIS EVENING.
HOWEVER...APPEARS PRECIP...OTHER THAN FLURRIES...WILL STICK TO OUR
SOUTHWEST. MODELS AGREE ON KEEPING MAIN AREA OF PRECIP TO THE
SOUTHWEST. ALSO...EXTRAPOLATION OF CURRENT SWATH OF LIGHT SNOW
ASSOCIATED WITH VORT MAX OVER CENTRAL IOWA WOULD SHOW MAIN AREA OF
PRECIP MOVING TO OUR SOUTHWEST.

LIGHT SNOW/FLURRIES WRAPPING AROUND THE LOW IN EAST CENTRAL
WISCONSIN WILL EXIT THIS EVENING AS THE LOW LIFTS NORTHEAST.
HOWEVER...KEPT FLURRY MENTION IN FOR THE NIGHT UNTIL DRY AIR
CURRENTLY IN MINNESOTA MOVES IN.

THE CLEARING AREA IN MINNESOTA HAS EXPANDED...AND MATCHES UP WELL
WITH THE RAP 850MB RH. WOULD HAVE THIS GETTING TO OUR WEST/NORTHWEST
AREA SOMETIME AROUND MIDNIGHT...PUTTING A HALT TO FLURRIES AS IT
MOVES IN. THIS COULD CREATE A PROBLEM FOR TONIGHT/S LOWS...COULD SEE
TEMPS REALLY DROP IF SIGNIFICANT CLEARING TAKES PLACE.

A WEAKER SHORTWAVE MOVES THROUGH TOMORROW AFTERNOON...SO EXPECTING
CLOUD COVER TO INCREASE FRIDAY MORNING WITH FLURRIES RETURNING.
THERE IS SOME PVA AND WAA BETWEEN 850 AND 700MB IN THE
AFTERNOON...BUT OVERALL NOT IMPRESSED BY Q VECTOR CONVERGENCE.

925MB COLD AIR ADVECTION TAKES HOLD TONIGHT. 925MB TEMPS DROP FROM
AROUND -3 TO -5C AT 00Z FRIDAY TO -11 TO -13C BY 12Z FRIDAY. NOT TOO
MUCH OF A REBOUND FOR FRIDAY EITHER. HIGHEST 925MB TEMPS ON FRIDAY
ABOUT -10 TO -12C. HOWEVER...MODELS HAVE BEEN A BIT COOL WHERE SNOW
PACK ISN/T AS SIGNIFICANT. PUT IN HIGHS IN THE 22-27F RANGE.

SATURDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
SOUTHERN WISCONSIN IS ON THE WESTERN PERIPHERY OF THE LARGE UPPER
TROUGH AXIS. MODELS SHOW SHEARED CYCLONIC VORTICITY AXIS MOVING
ACROSS SOUTHERN WISCONSIN. SATURATED LOW LEVELS BELOW AN INVERSION
AROUND 5 THSD FT WITH STEEP LAPSE RATES BELOW THE INVERSION. SOME
FLURRY POTENTIAL.

SURFACE RIDGE AXIS THEN NUDGES INTO WESTERN WISCONSIN BY THE END
OF THE DAY.

SATURDAY NIGHT THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE...MEDIUM
TO HIGH

THE HIGH PRESSURE RIDGE SHIFTS EAST OF AREA WITH THE PLAINS
TROUGH APPROACHING. WARM ADVECTION UNDERWAY THROUGH THIS PERIOD.
WARMEST 925 TEMPS ARRIVE SUNDAY NIGHT WITH READINGS RISING TO AT
OR ABOVE 0 CELSIUS. SHOULD BE A NON DIURNAL TEMPERATURE TREND
WITH RISING TEMPERATURES.

MONDAY AND MONDAY NIGHT FORECAST CONFIDENCE...MEDIUM TO HIGH

THE MID/UPPER LEVEL UPPER TROUGH EXITS THE NORTHERN AND CENTRAL
PLAINS MONDAY AND MOVES INTO THE WESTERN GREAT LAKES MONDAY NIGHT.

A DECENT SURGE OF MOISTURE ADVECTS NORTHWARD AHEAD AND ALONG OF
THE LOWER LEVEL TROUGH. GFS/GEM AND ECMWF ALL SHOW PRECIP ARRIVING
MONDAY AFTERNOON AND MONDAY NIGHT. THICKNESS AND 850 MB
TEMPERATURES TREND TOWARD A MIX OR MAINLY SNOW EXCEPT FAR
SOUTHEAST. HOWEVER GFS FORECAST SOUNDING SHOW A WARM BOUNDARY
LAYER WHICH WOULD BRING MORE RAIN SOUTH AND RAIN/SNOW NORTH.

850/925 TEMPS THEN COLLAPSE DURING THE EVENING TRANSITIONING THE
PRECIPITATION TO SNOW.

.LONG TERM...

TUESDAY...FORECAST CONFIDENCE...MEDIUM

LINGERING CYCLONIC FLOW FROM THE DEPARTING MID LEVEL TROUGH SUGGESTS
KEEPING SOME SMALL POPS EAST FOR SNOW SHOWERS EARLY. THEN
PRONOUNCED DRYING. DECENT COLD ADVECTION EXPECTED BEHIND THE
STRENGTHENING LOW TO THE EAST/NORTHEAST.

WEDNESDAY...FORECAST CONFIDENCE...

BROAD CYCLONIC FLOW MOVES OFF AS A MID LEVEL RIDGE MOVES ACROSS
WISCONSIN. A RATHER STRONG CANADIAN HIGH WILL BE RIDGING SOUTHEAST
INTO THE AREA CONTINUING THE COLD TEMPERATURES.

THURSDAY...FORECAST CONFIDENCE...

STRONG SHORTWAVE OVER THE SOUTHWEST U.S. LIFTS NORTHEAST. MAIN
DIFFERENCE IS THAT THE 12Z ECMWF IS SOMEWHAT SLOWER AND FARTHER SOUTH.

GFS AND ECMWF BOTH BRING A STRONG LOW THAT WOULD FAVOR HEAVY SNOW
EVENTUALLY AFFECTING PORTIONS OF THE FORECAST AREA. THE ECMWF IS A
FAVORABLE TRACK FOR HEAVY SNOW OVER SOUTHEAST WISCONSIN...WITH THE
GFS A LITTLE FARTHER NORTH. HEAVY PRECIPITATION AMOUNTS ON BOTH
MODELS...WITH THE HEAVIEST ON THE GFS. THIS WILL BE A POTENTIAL
SNOWSTORM FOR LATER THURSDAY OR FRIDAY. PREFER THE SOMEWHAT SLOWER
ECMWF SO WILL NOT RAISE POPS FROM THE CONSENSUS GRIDS ON THURSDAY.

.AVIATION/00Z TAFS/...

VFR CEILINGS WERE WEST OF ABOUT A JANESVILLE TO GREEN LAKE LINE
AROUND MID AFTERNOON. THINKING THESE CONDITIONS WILL SPREAD EAST
THIS EVENING AS THE SURFACE LOW MOVES EAST. NAM AND GFS SOUNDINGS
QUITE DIFFERENT IN TERMS OF CEILING HEIGHT. THINKING THE SOLUTION IS
SOMEWHERE IN THE MIDDLE BASED ON UPSTREAM OBS. LEANING TOWARDS VFR
CONDITIONS FOR THE MAJORITY OF THE NIGHT ONCE THE LOW MOVES EAST.
AREA OF DRY AIR OVER MINNESOTA HAS EXPANDED AND WILL LIKELY ARRIVE
IN OUR AREA AFTER MIDNIGHT. MORE CONFIDENT IN VFR CONDITIONS THEN.
COULD SEE SCATTERED FLURRIES TONIGHT UNTIL DRY AIR OVER MINNESOTA
MOVES IN. NOT EXPECTING ANY ACCUMULATION AT THE TAF SITES THOUGH.
CLOUDS WILL BUILD BACK IN FRIDAY MORNING AS ANOTHER SHORTWAVE
APPROACHES. THIS WILL BRING ANOTHER CHANCE FOR FLURRIES AS WELL. NOT
EXPECTING MUCH IF ANY ACCUMULATION.

.MARINE...

A SMALL CRAFT ADVISORY IS IN EFFECT THROUGH MIDNIGHT TONIGHT AS LOW
PRESSURE MOVES OFF TO THE NORTHEAST. SOUNDINGS SHOW WIND GUSTS
DIMINISHING AFTER MIDNIGHT. HOWEVER...THE PRESSURE GRADIENT IS STILL
FAIRLY TIGHT THROUGH FRIDAY MORNING AND THERE COULD BE A FEW GUSTS
TO CRITERIA AFTER MIDNIGHT.

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LMZ643>646.

TONIGHT/FRIDAY AND AVIATION/MARINE...MEB
FRIDAY NIGHT THROUGH THURSDAY...HENTZ

AREA FORECAST DISCUSSION

NWS MILWAUKEE/SULLIVAN WI

306 PM CST THU FEB 14 2013

.SHORT TERM...

.TONIGHT AND FRIDAY...FORECAST CONFIDENCE MEDIUM.

SURFACE RIDGE AXIS THEN NUDGES INTO WESTERN WISCONSIN BY THE END
OF THE DAY.

SATURDAY NIGHT THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE...MEDIUM
TO HIGH

MONDAY AND MONDAY NIGHT FORECAST CONFIDENCE...MEDIUM TO HIGH

THE MID/UPPER LEVEL UPPER TROUGH EXITS THE NORTHERN AND CENTRAL
PLAINS MONDAY AND MOVES INTO THE WESTERN GREAT LAKES MONDAY NIGHT.

850/925 TEMPS THEN COLLAPSE DURING THE EVENING TRANSITIONING THE
PRECIPITATION TO SNOW.

.LONG TERM...

TUESDAY...FORECAST CONFIDENCE...MEDIUM

WEDNESDAY...FORECAST CONFIDENCE...

BROAD CYCLONIC FLOW MOVES OFF AS A MID LEVEL RIDGE MOVES ACROSS
WISCONSIN. A RATHER STRONG CANADIAN HIGH WILL BE RIDGING SOUTHEAST
INTO THE AREA CONTINUING THE COLD TEMPERATURES.

THURSDAY...FORECAST CONFIDENCE...

STRONG SHORTWAVE OVER THE SOUTHWEST U.S. LIFTS NORTHEAST. MAIN
DIFFERENCE IS THAT THE 12Z ECMWF IS SOMEWHAT SLOWER AND FARTHER SOUTH.

.AVIATION/00Z TAFS/...

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LMZ643>646.

TONIGHT/FRIDAY AND AVIATION/MARINE...MEB
FRIDAY NIGHT THROUGH THURSDAY...HENTZ

AREA FORECAST DISCUSSION

NWS LA CROSSE WI

237 PM CST THU FEB 14 2013

.SHORT TERM...TONIGHT THROUGH SUNDAY
237 PM CST THU FEB 14 2013

MAIN FORECAST CONCERNS FOR THE SHORT TERM PERIOD:
1. TEMPERATURE AND CLOUD TRENDS THROUGHOUT

CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING JUST OFF THE WEST COAST OF THE U.S. INTO BRITISH
COLUMBIA...WHILE TROUGHING COVERED MUCH OF EASTERN CANADA INTO THE
NORTHERN PLAINS AND WESTERN GREAT LAKES REGION. COMING THROUGH THE
TROUGH WAS A SHORTWAVE TROUGH APPROACHING THE SIOUX FALLS SOUTH
DAKOTA AREA...WHILE ANOTHER SHORTWAVE WAS SEEN IN CENTRAL
SASKATCHEWAN. THE SHORTWAVE THAT AFFECTED THE AREA LAST NIGHT INTO
THIS MORNING HAS MOVED OFF INTO LOWER MICHIGAN. RADAR IMAGERY SHOWED
A FEW RAIN/SNOW SHOWERS OVER MUCH OF WISCONSIN IN THE WAKE OF THE
LOWER MICHIGAN SHORTWAVE...DUE TO CYCLONIC FLOW OF LOW LEVEL
MOISTURE AND STEEP LOW LEVEL LAPSE RATES. TO THE WEST...RADAR ALSO
SHOWS A BAND OF RAIN/SNOW FROM CENTRAL SOUTH DAKOTA INTO NORTHWEST
IOWA...ASSOCIATED WITH THE SIOUX FALLS SHORTWAVE. NORTHWEST LOW
LEVEL WINDS BETWEEN THE TWO SHORTWAVES ARE GRADUALLY BRINGING IN
COLDER AIR. SOUNDINGS AT BIS...ABR...MPX AND INL ALL HAD 850MB TEMPS
DROP 3-4C BETWEEN 00Z AND 12Z...ALL BETWEEN -7 AND -12C AS OF 12Z.
SOME DRIER AIR WAS ALSO ACCOMPANYING THE NORTHWEST WINDS...NOTED BY
SATELLITE IMAGERY SHOWING CLEARING ACROSS NORTHERN MN.

TONIGHT THROUGH SATURDAY DEFINITELY ARE GOING TO BE COLDER THAN
AS OF LATE. THE SHORTWAVE OVER CENTRAL SASKATCHEWAN COMBINED WITH
ANOTHER SHORTWAVE CURRENTLY UP IN NORTHERN MANITOBA ARE GOING TO
DIG SOUTH...CARVING OUT A DEEP TROUGH OVER THE REGION BY 00Z
SATURDAY. 850MB TEMPS FALL AS THIS TROUGH FORMS...DROPPING TO -14
TO -18C BY 18Z FRIDAY AND -16 TO -20C BY 12Z SATURDAY PER MODEL
CONSENSUS. THOSE AT 12Z SATURDAY ARE 1.5 STANDARD DEVIATIONS BELOW
NORMAL. THE ONLY MITIGATING FACTOR TO THE COLD AIR WOULD BE THE
LACK OF SNOW OVER THE SOUTHWEST HALF OF THE FORECAST AREA...WHICH
IF SOME SUN CAN OCCUR WOULD REALLY HELP TO BOOST TEMPS UP GIVEN
THE CLIMBING SUN ANGLE NOW. GENERALLY FOLLOWED A BLEND OF THE
ECMWF AND 30 DAY BIAS CORRECTED GFS GRIDDED MOS GUIDANCE DATA
SINCE THEY HAVE BEEN DOING WELL AS OF LATE FOR HIGHS. LOWS ARE
HIGHLY CONTINGENT ON CLOUD COVER. AFTER SOME CLEARING TONIGHT...
MORE LOW TO MID CLOUDS MOVE IN FROM THE NORTHWEST FOR FRIDAY AND
FRIDAY NIGHT...ASSOCIATED WITH THAT SHORTWAVE DROPPING DOWN OUT OF
MANITOBA. THESE CLOUDS COMBINED WITH A NORTHWEST BREEZE SHOULD
HELP KEEP LOWS FROM BOTTOMING OUT...THUS A BLEND OF GUIDANCE FOR
LOWS SEEMS REASONABLE.

HANDLING CLOUD COVER SATURDAY COULD BE TRICKY. A RIDGE OF HIGH
PRESSURE IS PROGGED TO BUILD INTO THE WESTERN PORTIONS OF THE
FORECAST AREA. WILL FOLLOW THE GENERAL MODEL CONSENSUS OF THE LOW
CLOUDS BREAKING UP THROUGH THE DAY...DUE TO A COMBINATION OF THE LOW
LEVEL FLOW BECOMING ANTICYCLONIC AND DAYTIME MIXING. HOWEVER...IT IS
POSSIBLE THE CLOUDS COULD HANG ON FOR MUCH OF THE DAY. THIS COMBINED
WITH 850MB TEMPS STILL ONLY BETWEEN -14C WEST TO -20C EAST AT 18Z
WILL KEEP TEMPERATURES SEASONABLY COOL.

FOR SATURDAY NIGHT AND SUNDAY...A POTENT SHORTWAVE TROUGH IS PROGGED
TO DROP INTO THE PACIFIC NORTHWEST AND NORTHERN ROCKIES...FORMING
TWO DISTINCT LOW PRESSURE AREAS ACROSS THE PLAINS DURING THE DAY
SUNDAY. A SOUTHERLY LOW LEVEL JET WILL DEVELOP AHEAD OF THESE TWO
LOWS...BRINGING UP WARMER AIR. AN INCREASE OF MID AND HIGH CLOUDS
ARE LIKELY TO ACCOMPANY THIS WARM ADVECTION. SO THE QUESTION FOR
LOWS SATURDAY NIGHT IS TIMING OF WHEN THE WARM ADVECTION STARTS UP
AND MID CLOUDS MOVE IN...VERSUS THE DEPARTURE TO THE EAST OF THE
SURFACE RIDGE. OUR WISCONSIN COUNTIES HAVE THE BEST SHOT OF
FAVORABLE RADIATIONAL COOLING CONDITIONS...THUS LEANED TOWARDS THE
COLDER SIDE OF GUIDANCE THERE. TEMPERATURES SHOULD RISE FROM LATE
SATURDAY NIGHT THROUGH SUNDAY AT MOST LOCATIONS AS SOUTHERLY WINDS
INCREASE. QUESTION ON SUNDAY IS HOW WARM DO WE GET...WITH 850MB
TEMPS THAT COULD APPROACH 0C NEAR CHARLES CITY IA BY 00Z MONDAY. IT
APPEARS SUNSHINE WILL BE ON THE INCREASE WEST OF THE MS RIVER AS THE
MID CLOUD LIFTS TO THE NORTH. GIVEN THE LACK OF SNOW OVER THE
SOUTHWEST HALF OF THE FORECAST AREA...LEANED MORE TOWARDS THE
CONSISTENTLY WARM ECMWF...BRINGING HIGHS AT LEAST TO THE MID 30S
AROUND CHARLES CITY.

PRECIPITATION WISE...MUCH OF THE SHORT TERM LOOKS DRY WITH RESPECT
TO REACHING 0.01" OF LIQUID EQUIVALENT IN ANY 12 HOUR PERIOD.
FLURRIES LOOK LIKELY...HOWEVER...FOR FRIDAY AND FRIDAY NIGHT OUT OF
THOSE LOW CLOUDS SINCE THEY EXIST WITHIN THE DENDRITIC GROWTH ZONE
AND HAVE WEAK LIFT FROM THE SHORTWAVE. PREVIOUS FORECAST MENTIONED
CONCERN THAT AS THE WARM ADVECTION STARTS UP SATURDAY NIGHT THAT WE
COULD SEE SOME SNOW FALL OUT OF THE ASSOCIATED MID CLOUD DECK. THAT
STILL REMAINS A CONCERN...THOUGH THINK FLURRIES WOULD BE THE MOST
THAT GETS PRODUCED. THEN AGAIN...THESE FLURRIES MIGHT BE ABSORBED BY
LOWER LEVEL DRY AIR. FOR NOW HAVE KEPT THE FORECAST DRY FOR SATURDAY
NIGHT AND SUNDAY.

.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
237 PM CST THU FEB 14 2013

MAIN CONCERNS FOR THE LONG TERM PERIOD...
1. TEMPERATURES AND PRECIPITATION POTENTIAL THROUGH MONDAY
2. BRIEF ARCTIC AIR SHOT FOR MID-WEEK
3. POTENTIAL FOR A WINTER STORM TO IMPACT THE AREA LATE IN THE WEEK

VERY GOOD MODEL AGREEMENT EXISTS AMONGST THE 14.12Z
ECMWF/GFS/CANADIAN/UKMET THROUGHOUT MUCH OF THE LONG TERM PERIOD.
FOR SUNDAY NIGHT INTO MONDAY...THE TROUGHING THAT WAS COMING ACROSS
THE NORTHERN ROCKIES EVOLVES BY MONDAY EVENING INTO A FULL
LONGITUDINAL TROUGH ACROSS THE CANADIAN AND U.S. PLAINS. THIS
TROUGHING EVENTUALLY PHASES TOGETHER AS IT CROSSES THE REGION AND
HEADS INTO THE GREAT LAKES FOR TUESDAY. PRIOR TO THE PHASING...A
REALLY STRONG PUSH OF WARM AIR COMES UP AT THE REGION WITH 850MB
TEMPS BETWEEN -2C AND +4C AT 12Z MONDAY. HAVE BOOSTED HIGH
TEMPERATURES FOR MONDAY AS A RESULT...THOUGH COULD BE EVEN HIGHER AS
NOTED BY THE 14.12Z ECMWF. ALSO...MODELS CONTINUE TO TREND
FARTHER WEST WITH THE SOUTHERN LOW COMING OUT OF THE SOUTHERN
PLAINS. AS SUCH...NOW ABOUT THE EASTERN TWO THIRDS OF THE AREA IS
AFFECTED BY LIGHT PRECIPITATION FOR MONDAY AFTERNOON AND EVENING.
THUS...HAVE EXPANDED LOW PRECIPITATION CHANCES FARTHER WEST AND
RAISED THEM 5-10 PERCENT. IF TRENDS CONTINUE...THESE CHANCES WILL
NEED TO BE RAISED MORE. WITH THE WARMER TEMPERATURES TOO...MIXING
WITH OR CHANGING TO RAIN IS AN ISSUE AS WELL.

AS THE PHASED TROUGH FORMS OVER THE AREA MONDAY NIGHT AND TUESDAY...
ARCTIC AIR FLOWS INTO THE REGION. 850MB TEMPS PLUMMET TO -12 TO -14C
BY 12Z TUESDAY AND -14 TO -20C BY 12Z WEDNESDAY. THUS...A MUCH
COOLER PERIOD IS ON TAP AGAIN. CANADIAN HIGH PRESSURE BUILDING DOWN
INTO THE NORTHERN PLAINS...IN THE WAKE OF THE PHASED TROUGH...WILL
PROVIDE FOR BLUSTERY CONDITIONS. WIND CHILLS RIGHT NOW LOOK TO STAY
JUST ABOVE ADVISORY CRITERIA...BOTTOMING OUT AT MOST IN THE -15 TO
-20F RANGE WEDNESDAY MORNING.

LASTLY...ABOUT THE POTENTIAL WINTER STORM LATE IN THE WEEK. THERE IS
SURPRISINGLY CONSISTENT AND GOOD MODEL AGREEMENT AMONGST THE
ECMWF...GFS AND THEIR RESPECTIVE ENSEMBLES OF A DEEP TROUGH FORMING
OVER THE WESTERN U.S. ON WEDNESDAY. AS THIS TROUGH HEADS EAST
TOWARDS THE PLAINS...A DEEP LOW PRESSURE AREA DEVELOPS OVER THE
CENTRAL PLAINS BY THURSDAY MORNING. THERE ARE A FEW QUESTIONS FROM
HERE ON...WHICH MAY TAKE AT LEAST A FEW MORE DAYS TO ANSWER:
1. TIMING AND STRENGTH AS USUAL
2. HOW QUICK DOES THE PRECIPITATION SPREAD INTO THE AREA IF IT
INDEED AFFECTS US
3. HOW MUCH PRECIPITATION WOULD OCCUR
4. DEPENDING ON HOW MUCH THE SYSTEM WRAPS UP...MAY HAVE TO DEAL WITH
PRECIPITATION TYPE ISSUES
FOR NOW HAVE STAYED WITH A CONSENSUS APPROACH...WHICH BY THURSDAY
NIGHT YIELDS 50-60 PERCENT CHANCES OF PRECIPITATION REGION-WIDE. ALL
PRECIPITATION RIGHT NOW LOOKS TO FALL AS SNOW...WHICH COULD BE
SIGNIFICANT. SINCE THE STORM IS VERY FAR OUT IN THE FORECAST AND
JUST BEYOND THE CURRENT HWO PERIOD...HAVE KEPT THE MENTION OF THE
STORM TO THIS DISCUSSION ONLY. HOWEVER...IF TRENDS ON THIS SYSTEM
CONTINUE...LATER SHIFTS WILL NEED TO MENTION THE STORM IN THE HWO
AND IN OTHER DECISION SUPPORT SERVICES.

.AVIATION...THROUGH 18Z FRIDAY
1210 PM CST THU FEB 14 2013

WHILE VISIBILITIES NOT EXPECTED TO HAMPER AVIATION...CEILINGS WILL
BE TROUBLESOME WITH ONE SHORT WAVE TROUGH PASSING BY TO THE
SOUTHWEST AND A MIX OF STRATUS AND MID LEVEL CLOUDS UPSTREAM.

COMBINATION OF PASSING SHORT WAVE AND CYCLONIC FLOW FROM PREVIOUS
SYSTEM...CLOUDS WILL FILL IN QUITE A BIT REST OF TODAY WITH GENERAL
VFR AND LIMITED MVFR CEILINGS ANTICIPATED. COULD ALSO SEE SOME SNOW
SHOWERS BUT AGAIN...DO NOT EXPECT BIG IMPACT THERE.

SUBSIDENCE TO THE NORTH SHOULD PRODUCE PERIOD TONIGHT OF CLEAR TO
SCATTERED DECKS BEFORE MAINLY MID LEVEL CLOUDS ADVECT BACK IN EARLY
FRIDAY. STEEP LAPSE RATES SUGGEST STRATUS AND FLURRIES COULD
DOMINATE ON FRIDAY AS WELL BUT MAINLY VFR CONDITIONS SHOULD PREVAIL.

.ARX WATCHES/WARNINGS/ADVISORIES...
237 PM CST THU FEB 14 2013

WI...NONE.
MN...NONE.
IA...NONE.

SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....SHEA