Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/09/13

AREA FORECAST DISCUSSION

NWS SACRAMENTO CA

844 AM PST THU FEB 7 2013

.SHORT TERM DISCUSSION...

A POTENTIALLY ACTIVE WEATHER DAY IS SHAPING UP FOR INTERIOR NORCAL
WITH MULTIPLE WEATHER CONCERNS INCLUDING THUNDERSTORMS THIS
AFTERNOON IN THE CENTRAL VALLEY AND LOWER-ELEVATION SNOW IN THE
SIERRA THIS EVENING.

CURRENT WATER VAPOR IMAGERY SHOWS A BROAD CIRCULATION CENTER NEAR
VANCOUVER ISLAND BC DROPPING SOUTHWARD ALONG THE WEST COAST. A
MOISTURE PLUME WRAPPING AROUND ITS BASE AND INTO NORCAL IS QUICKLY
SHIFTING SOUTHWARD. DRIER BUT MORE UNSTABLE AIR LIES JUST UPSTREAM
AND HAS ALREADY REACHED A UKIAH-CHICO LINE. VIS IMAGERY SHOWS
CLEARING OVER THE COASTAL MOUNTAINS WITH SCATTERED CONVECTIVE
CLOUDS...ALTHOUGH NO CLOUD-TO-GROUND LIGHTNING STRIKES YET. AT THE
SURFACE...THE BEALE RADAR SHOWS THAT PRECIP WITH THE SURFACE FRONT
IS NEARING THE SAC METRO AREA...WHILE THE NORTHERN EDGE HAS
ALREADY PASSED REDDING. LOOKING THROUGH THE VARIOUS MODELS THIS
MORNING...THE RUC CURRENTLY HAS THE BEST HANDLE ON TIMING OF THE
PRECIP...SO WILL BE LEANING ON THAT MODEL.

CONVECTIVE POTENTIAL IS LOOKING BETTER FOR TODAY WITH THE SURFACE
FRONT SPEEDING UP AND LIKELY PUSHING EAST OF THE SAC VALLEY BY THE
AFTERNOON PER THE LATEST RUC. BIGGEST QUESTION WILL BE HOW MUCH
CLEARING AND SUBSEQUENT WARMING WE CAN GET. IN BUFKIT...THIS
MORNING`S NAM WARMS TEMPS UP NICELY IN THE CENTRAL/SOUTHERN SAC
VALLEY AND THUS HAS A JUICY SOUNDING (FOR OUR AREA) OVER
SACRAMENTO BY 4 THIS AFTERNOON WITH 300J/KG CAPE EXTENDING UP TO
18KFT AGL AND GOOD 0-6KM SHEAR. THIS GETS INTO THE RANGE THAT LOCAL
RESEARCH HAS CONNECTED WITH EF0 TORNADOES. EXPECTING SMALL HAIL AT LEAST
GIVEN THAT MOST OF THE CAPE IS ABOVE THE FREEZING LEVEL. ALL
MODELS SHOW GOOD 0-1 AND 0-6KM SPEED SHEAR THANKS TO SURFACE WINDS
REMAINING RELATIVELY LIGHT EVEN AFTER THE FRONT PASSES WHILE
WESTERLY WINDS ALOFT PICK UP.

THE OTHER CONCERN IS THE FIRST SNOW IN A WEEK OR SO OVER THE
SIERRA AND FOOTHILLS. THE HMT SNOW LEVEL SENSOR AT SHASTA LAKE INDICATES
SNOW LEVELS DOWN TO 3000FT ON THE BACKSIDE OF THE FRONT WHILE CAMS
SHOW ACCUMULATING SNOW DOWN TO 3500 FEET...WHICH IS IN GOOD
AGREEMENT WITH CURRENT FORECAST. WINTER WEATHER ADVISORY OVER THE
MOUNTAINS LOOKS GOOD FOR NOW...WILL PROBABLY UPDATE THE TIMING
WITH THE AFTERNOON PACKAGE AS WE MAY WANT TO CLEAR OUT THE COASTAL
MOUNTAINS SOONER.

PREVIOUS FORECAST LOOKS GOOD SO NO MORNING UPDATES NEEDED. THE
DISCUSSION BELOW PROVIDES AN EXCELLENT OVERVIEW OF THE SITUATION.
-DVC

.PREVIOUS DISCUSSION...ISSUED 522 AM PST...
FRONTAL BAND NOW MOVING INTO NORTHWEST CALIFORNIA BRINGING LIGHT
SHOWERS TO WESTERN SHASTA COUNTY AT THIS TIME. THIS FRONT IS
FORECAST TO MAKE ITS WAY EASTWARD DURING THE DAY WITH THE LATEST
NAM12 INDICATING FRONTAL PASSAGE THROUGH THE REDDING AREA AND
TRAILING BACK TO THE BAY AREA BY AROUND 00Z. PRECIPITATION FROM
THIS SYSTEM WILL BE RELATIVELY LIGHT BUT IT WILL USHER IN MUCH
COOLER AIR FOR DAYTIME HIGHS 10 OR MORE DEGREES BELOW WEDNESDAY
HIGHS. DROPPING SNOW LEVELS WILL DROP SNOW DOWN INTO THE FOOTHILLS
LATER TODAY WITH ENOUGH NUISANCE SNOWFALL TO KEEP WINTER WEATHER
ADVISORIES FOR THE MOUNTAINS AND HIGHER FOOTHILLS IN PLACE. COLD
UPPER LOW WILL BEGIN PUSHING INTO NORCAL THIS AFTERNOON AND MAY
CREATE MOST SIGNIFICANT SHORT TERM WEATHER CONCERN. LATEST NAM AND
GFS BOTH SHOWING NEGATIVE LI VALUES THROUGHOUT THE SACRAMENTO
VALLEY THIS AFTERNOON. INSTABILITY COMBINED WITH MOISTURE AND LIFT
WILL MAKE ISOLATED THUNDERSTORMS IN THIS REGION A GOOD
POSSIBILITY. 06Z MU CAPE FROM NAM12 SHOWS AREA OF MOST INSTABILITY
OVER THE CENTRAL SACRAMENTO VALLEY THIS AFTERNOON SO THIS LIKELY
TO BE AREA OF HIGHEST THUNDERSTORM POTENTIAL. 0-1 AND 0-6KM SHEAR
IN THIS REGION DOES PLACE IT WITHIN HISTORICAL REALM OF WEAK
TORNADIC ACTIVITY. THERE ARE SEVERAL LIMITING FACTORS HOWEVER.
CAPE IS SOMEWHAT LIMITED AT BETWEEN 200 AND 300 J/KG AND LOW LEVEL
LAPS RATES ARE NOT IDEAL AS WELL. IN ADDITION...JET LOCATION
AROUND BOTTOM OF LOW A BIT TOO FAR SOUTH TO FULLY IMPACT THE
CENTRAL SACRAMENTO VALLEY. FINALLY...MODELS OVER THE LAST 24 HOURS
HAVE SLOWED THE INITIAL FRONT A BIT SO CLOUD COVER COULD REMAIN IN
PLACE ALL DAY LIMITING SURFACE HEATING. BELIEVE THESE FACTORS
TOGETHER WILL INHIBIT SEVERE THUNDERSTORM DEVELOPMENT BUT MINOR
CHANGES COULD MAKE SEVERE WEATHER MORE LIKELY AND AN EYE WILL NEED
TO BE KEPT ON THE SACRAMENTO VALLEY TODAY. HAVE ADDED A THREAT OF
THUNDERSTORMS TO THE FOOTHILLS THIS AFTERNOON SINCE THE FRONTAL
BAND IS FORECAST TO BE THERE LATE THIS AFTERNOON DURING MAXIMUM
HEATING.

UPPER LOW CENTER SHIFTS SOUTH OF CWA BY FRIDAY MORNING AND BY
FRIDAY AFTERNOON ANY PRECIP THREAT SHOULD BE LIMITED TO THE
SIERRA...FOOTHILLS AND SAN JOAQUIN VALLEY. A LITTLE MORE SUN WILL
BRING WARMING TO SOME AREAS. WRAP AROUND MOISTURE WILL KEEP SHOWER
THREAT GOING OVER THE NORTHERN SIERRA THROUGH SATURDAY MORNING. BY
SATURDAY AFTERNOON...DRY NORTHERLY FLOW WILL TAKE OVER WITH STILL
MORE WARMING EXPECTED. A MODERATE NORTHERLY SURFACE GRADIENT WILL
BRING BREEZY NORTH WINDS ACROSS THE ENTIRE CWA. THESE WINDS WILL
DROP OFF ON SUNDAY AS LARGE UPPER RIDGE OF HIGH PRESSURE PUSHES
INLAND OVER THE WEST COAST. SUNDAY WILL BRING THE BEGINNING OF A
WARMING TREND EXPECTED TO LAST INTO MID WEEK.

.EXTENDED DISCUSSION (MONDAY THROUGH THURSDAY)

DRY WEATHER CONTINUES THROUGH THE EXTENDED PERIOD AS HIGH PRESSURE
OVER THE EASTERN PACIFIC BUILDS INTO CALIFORNIA. SUNDAY MAY
CONTINUE TO BRING LOCALLY BREEZY NORTHEAST WINDS TO FAVORABLY
ORIENTED CANYONS OF THE SIERRA. THESE WINDS SHOULD BEGIN TO TAPER
OFF BY EARLY NEXT WEEK. MODEST WARMING TREND SHOULD CONTINUE AT
LEAST INTO EARLY NEXT WEEK AS THE UPPER RIDGE SHIFTS OVERHEAD.
THIS COULD POTENTIALLY LEAD TO SOME PATCHY MORNING FOG IN THE
VALLEYS. CONFIDENCE DROPS BY THE MIDDLE OF NEXT WEEK WITH THE
MODEL HANDLING OF SMALL-SCALE FEATURES. DANG

.AVIATION...

COLD FRONT AND BAND OF SHOWERS N OF THE I-80 CORRIDOR FORECAST TO
MOVE SEWD INTO THE I-80 CORRIDOR BY 18Z- 20Z...CONTINUING INTO THE
AFTERNOON AND EARLY EVENING. WDSPRD MVFR CIGS AND VSBYS EXPECTED
WITH BAND OF SHOWERS. LIFR VSBYS IN THE SCK/MOD AREAS EXPECTED TO
IMPROVE 18Z-20Z WITH APPROACHING FRONT AND BAND OF SHOWERS. CIGS
LOWERING TO WDSPRD IFR/LIFR OVER MTNS IN SNOW...WITH SNOW LEVEL
LOWERING TO 3 KFT DURING THE DAY AND EARLY EVENING FROM N TO S.
BEHIND THE FRONT ISOLATED TSRA- TSRAGS WILL BE POSSIBLE THROUGH
EARLY EVENING. SOUTHERLY WINDS 5-15 KT THROUGH ABOUT 00Z SHOULD
BECOME LIGHT THIS EVENING.

.STO WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 AM PST FRIDAY BURNEY BASIN /
EASTERN SHASTA COUNTY...MOUNTAINS SOUTHWESTERN SHASTA COUNTY TO
NORTHERN LAKE COUNTY...NORTHEAST FOOTHILLS/SACRAMENTO VALLEY...
SHASTA LAKE AREA / NORTHERN SHASTA COUNTY...WESTERN PLUMAS
COUNTY/LASSEN PARK.

WINTER WEATHER ADVISORY UNTIL 10 AM PST FRIDAY WEST SLOPE
NORTHERN SIERRA NEVADA.

WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM PST
FRIDAY MOTHERLODE.

AREA FORECAST DISCUSSION

NWS DENVER/BOULDER CO

405 PM MST FRI FEB 8 2013

.SHORT TERM...UPPER LEVEL TROUGH AND MID LEVEL LOW OVER SOUTHERN
GREAT BASIN WITH STRONG SOUTHWEST FLOW ACROSS COLORADO. WINDS HAVE
BEEN GUSTY ACROSS MUCH OF THE PLAINS WHICH HELPED TO ELEVATE THE
FIRE DANGER. HUMIDITY READINGS WERE IN THE MID AND UPPER TEENS
WHICH KEPT CRITICAL FIRE WEATHER CONCERNS TO A MINIMUM. A WEAK
BOUNDARY EXTENDING FROM EAST OF DENVER TO THE SOUTHERN DENVER
SUBURBS HAS KEPT THE GUSTY WINDS FROM SPREADING NORTH ACROSS THE
DENVER AREA. OVER THE MOUNTAINS... DRY CONDITIONS PREVAILING WITH
SOME MID AND HIGH LEVEL CLOUDS. WINDS WERE A BIT GUSTY ACROSS THE
RIDGES AND SOUTHERN FOOTHILLS. MODELS SHOW THE SYSTEM MOVING EAST
DURING THE EVENING...WITH MID LEVEL LOW OVER SOUTHEAST NEVADA.
SOUTHWEST FLOW ALOFT OVER COLORADO BECOMES A BIT MORE SOUTHERLY.
LATEST RAP SHOWS MID LEVEL ASCENT INCREASING ACROSS MOUNTAINS WITH
LAPSE RATE AROUND 7 C/KM. MOISTURE DOES INCREASE DURING THE
EVENING...WITH THE BETTER MOISTURE HOLDING OFF UNTIL AFTER
MIDNIGHT. SHOULD SEE SOME SHOWERS DEVELOPING INITIALLY OVER THE
HIGHER RIDGES...WITH A BETTER CHANCE AFTER MIDNIGHT WHEN THE
MOISTURE INCREASES. FLOW NOT ALL THAN FAVORABLE FOR SNOWFALL
OVERNIGHT...THOUGH A FEW SPOTS ALONG THE EXTREME WESTERLY SECTIONS
OF THE FORECAST AREAS. ACROSS PLAINS...WINDS TO GRADUALLY AND
BECOME MORE SOUTHWEST WITH VARIABLE MID AND HIGH LEVEL CLOUDS. ON
SATURDAY...MODELS SHOW UPPER TROUGH MOVING INTO THE GREAT BASIN
AND WESTERN COLORADO DURING THE MORNING...THEN ACROSS COLORADO
DURING THE AFTERNOON. THE MID LEVEL LOW SHIFTS FROM SOUTHWEST UTAH
AND SOUTHWEST NEVADA INTO WESTERN COLORADY BY 18Z...THEN OVER
NORTHEAST COLORADO BY 00Z SATURDAY EVENING. MOISTURE INCREASES AND
DEEPENS ACROSS THE MOUNTAINS DURING THE DAY ALONG WITH INCREASING
MID LEVEL QG ACCENT. WITH LAPSE RATES AROUND 7 C/KM EXPECTED...
AIRMASS BECOMES SLIGHTLY UNSTABLE. SO DESPITE THE UNFAVORABLE
OROGRAPHICS...SHOULD SEE SNOW INCREASE ACROSS THE MOUNTAINS BY THE
AFTERNOON. WILL HOIST AN ADVISORY FOR SNOW FOR ZONE 31 BEGINNING
AT 18Z...AND ADVISORIES FOR ZONES 33 AND 34 BEGINNING 21Z. THE
ADVISORIES WILL EXTEND THROUGH SUNDAY MORNING. SNOW AMOUNTS WILL
INITIALLY BE LIGHT BUT SHOULD INCREASE DURING THE AFTERNOON. ALONG
FOOTHILLS...THE TRACK OF THE LOW WILL PROVIDE FOR MORE OF A
DOWNSLOPE NORTHWEST COMPONENT. BUT THERE WILL BE ENOUGH ASCENT TO
HELP OFFSET THE DOWSLOPE FLOW. WILL CONTINUE THE LIKELY POPS WITH
LIGHT SNOW AMOUNTS...THOUGH MAY BE A BIT MORE WIDESPREAD NEAR THE
WYOMING BORDER. ACROSS THE PLAINS...MODELS SHOW NORTHWESTERLIES
SPREADING ACROSS THE AREA LATE MORNING AND AFTERNOON. THIS
DOWNSLOPE WILL INITIALLY KEEP THE PRECIP LIMITED...BUT CHANCES
TO INCREASE BY THE EVENING WHEN THE LIFT GETS GREATER. CURRENT
FORECASTS STILL SEEM ON TRACK AND WILL NOT DEVIATE MUCH. DID
CHANGE THE RAIN/SNOW CHANCES TO ALL SNOW ACROSS NORTHERN WELD AND
NORTHERN LARIMER COUNTIES AS THE COLDER AIR APPEARS TO GET THERE
SOONER.

.LONG TERM...MODELS HAVE BEEN PRETTY CONSISTENT WITH THE
DEVELOPMENT OF THE LOW MOVING ACROSS COLORADO INTO NEBRASKA
SATURDAY NIGHT AND SUNDAY. THE ECMWF REMAINS FURTHER SOUTH THAN A
CLUSTER OF OTHER MODELS BY ABOUT 100 MILES...BRINGING THE LOW
ACROSS EAST CENTRAL COLORADO WHILE THE REST GO ACROSS THE
NORTHEAST CORNER. AS A RESULT THE LAST TWO RUNS OF THE ECMWF HAVE
PRODUCE ONE HALF TO ONE INCH OF LIQUID PRECIPITATION OVER THE
CORNER...WHILE OTHER MODELS HAVE LESS WITH THE HEAVY SNOW IN
NEBRASKA. OUR FORECAST HAS BEEN A COMPROMISE AND I SEE LITTLE
REASON TO CHANGE THIS. SO THIS PACKAGE IS PRIMARILY AN UPDATE TO
ISSUE ADVISORIES FOR THE HIGH MOUNTAINS.

FIRST FOR THE PLAINS...OUR COMPROMISE SOLUTION WOULD PROBABLY
STILL PRODUCE BLIZZARD CONDITIONS IN THE WATCH AREA...WITH SOME
CONCERN ABOUT NORTHERN PORTIONS OF WELD AND WASHINGTON COUNTIES AS
WELL. NOT NECESSARILY HEAVY SNOW AMOUNTS BUT THE COMBINATION OF
SNOW WITH THE STRONG WINDS. FURTHER WEST THERE SHOULD BE SOME SNOW
AND WIND THAT MAY STILL BE ENOUGH TO CAUSE TRAVEL DIFFICULTIES.
STILL UNRESOLVED IS THE LENGTH OF TIME THAT IT WILL SNOW BEFORE
THE DOWNSLOPE WINDS CUT IT OFF SATURDAY EVENING. THE MODELS
PRODUCE VERY LITTLE SNOW ALONG THE FRONT RANGE...AND WE HAVE BEEN
PRESUMING THAT THERE WOULD BE AT LEAST A BRIEF PERIOD OF SNOW WITH
THE TROUGH AXIS. THE STRONGER SOLUTIONS COULD LEAD TO A 3-6 HOUR
PERIOD OF NORTH WINDS AT LOW LEVELS...WHICH WOULD ALLOW FOR
HEAVIER SNOW THAN WE ARE FORECASTING. AT THIS POINT OUR FORECAST
STILL SEEMS A PRUDENT MIDDLE GROUND BETWEEN THE POSSIBLE
SOLUTIONS.

FOR THE MOUNTAINS WE WILL NEED TO WATCH THE AMOUNTS AS IT IS
FAIRLY UNSTABLE SATURDAY NIGHT...IF THE WIND DIRECTION IS MORE
WESTERLY THIS WOULD BE BAD FOR THE FRONT RANGE CITIES...BUT WOULD
PRODUCE MORE SNOW IN THE MOUNTAINS AND WE COULD NEED A WARNING.

AS THE MAIN SYSTEM EXITS...WEAK ISENTROPIC LIFT CREEPS NORTHWARD
AS A DEFORMATION ZONE ON THE NORTH SIDE OF THE SOUTHWEST LOW MOVES
IN. THIS COULD PRODUCE LIGHT SNOW OVER THE SOUTHERN AND WESTERN
PARTS OF OUR AREA...MORE LIKELY IN THE MOUNTAINS BUT NOT MUCH
REALLY TO STOP IT REACHING THE GROUND ON THE PALMER DIVIDE EITHER.
I NUDGED POPS/CLOUDS UP A BIT MORE SUNDAY NIGHT INTO MONDAY FOR
THIS...THOUGH IT APPEARS LITTLE THREAT OF SIGNIFICANT SNOWFALL AN
INCH TO MESS UP THE MONDAY MORNING RUSH HOUR IS NOT OUT OF THE
QUESTION.

NOT MUCH CHANGE TO THE REST...WARMING TREND THROUGH WEDNESDAY.
THERE COULD BE SOME LINGERING MOISTURE FOR VERY LIGHT SNOW IN THE
MOUNTAINS BUT ODDS OF THIS GET SMALLER WITH TIME. STILL LOOKING
FOR A TROUGH IN NW FLOW WEDNESDAY NIGHT OR EARLY THURSDAY. SOME
SOLUTIONS ARE STRONGER WITH THIS WITH MORE COLD ADVECTION ALOFT
PRODUCING BETTER DEVELOPMENT AS IT MOVES OVER THE ROCKIES. THE LOW
THREAT OF SNOW WE HAVE IS APPROPRIATE...MAY NEED MORE FOR THE
MOUNTAINS. IT WILL BE COLDER THURSDAY AND FRIDAY...SOME OF THE
SOLUTIONS ARE MUCH COLDER...MODEL CONSENSUS IS JUST DROPPING BACK
INTO THE 30S AGAIN AND WE WILL STICK WITH THAT FOR NOW.

.AVIATION...BOUNDARY JUST SOUTH AND EAST OF THE DENVER AREA HAS
KEPT THE GUSTY SOUTHERLY WINDS FROM REACHING DEN. SKEPTICAL ABOUT
BOUNDARY MOVING NORTHWARD THROUGH THE EVENING SO WILL KEEP THE
GUSTS OUT OF DEN. WINDS TO DECREASE AT APA DURING THE EVENING WITH
SOUTHERLY DRAINAGE PATTERN DOMINATING ACROSS THE AREA AIRPORTS BY
03Z. VFR TO CONTINUE WITH UNLIMITED CEILINGS. ON SATURDAY...MID
AND HIGH LEVEL MOISTURE TO INCREASE WITH CEILINGS AROUND 10000
FEET AGL BY 18Z WIND TO SHIFT TO THE NORTHWEST AFTER 15Z WITH
SPEEDS AROUND 12 KTS. CEILINGS TO GRADUALLY LOWER DURING THE
AFTERNOON WITH 6000 FEET AGL PREVAILING AROUND 21Z. THERE WILL BE
A CHANCE OF SHOWERS DEVELOPING DURING THE AFTERNOON...BEST CHANCE
AFTER 21Z. WILL CONTINUE A PROB30 OF A RAIN/SNOW MIX FOR DEN AND
INCLUDE FOR BJC AND APA WITH LOWER CEILINGS. ANY SNOW
ACCUMULATIONS WILL BE LIGHT...LESS THAN ONE HALF INCH THROUGH THE
AFTERNOON AND CONFINED TO THE GRASSY AREAS.

.BOU WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON
FOR COZ048-050-051.

WINTER WEATHER ADVISORY FROM 2 PM SATURDAY TO 11 AM MST SUNDAY
FOR COZ033-034.

WINTER WEATHER ADVISORY FROM 11 AM SATURDAY TO 11 AM MST SUNDAY
FOR COZ031.

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

AREA FORECAST DISCUSSION

NWS LINCOLN IL

837 PM CST FRI FEB 8 2013

.DISCUSSION...
ISSUED 830 PM CST FRI FEB 8 2013

LOW LEVEL CLOUD COVER CONTINUES TO HOLD OVER THE AREA THIS EVENING
WITH A FEW BREAKS STARTING TO SHOW UP OVER PARTS OF NW INDIANA AND
NORTH CENTRAL IL. HOWEVER...A LARGE BAND OF HIGH LEVEL CLOUDS WAS
ALREADY STREAKING EAST INTO THE MID MISSISSIPPI VALLEY EARLY THIS
EVENING AHEAD OF OUR NEXT WEATHER SYSTEM PUSHING OUT OF THE WEST
COAST. 00Z ILX SOUNDING STILL SHOWING A RATHER STRONG SUBSIDENCE
INVERSION ABOVE 925 MB WITH A VERY SHALLOW MOIST LAYER NOTED JUST
BELOW THE INVERSION. THE MOISTURE DEPTH HAS DECREASED SIGNIFICANTLY
FROM THIS MORNING WHICH OFFERS SOME HOPE FOR A DECREASE IN THE
STRATOCUMULUS OVER OUR AREA OVERNIGHT AND INTO SATURDAY MORNING.
SURFACE HIGH PRESSURE TO OUR NORTH WILL GRADUALLY WORK TO OUR
EAST OVERNIGHT WITH THE VAD WIND PROFILES ALREADY SHOWING LOW LVL
WINDS TURNING MORE ESE OUT OVER WEST CENTRAL IL.

CURRENT FORECAST HAS A GOOD HANDLE ON THE TRENDS THIS EVENING AND
OVERNIGHT...SO OTHER THAN SOME TWEAKS TO THE EARLY EVENING SKY
COVER AND HOURLY TEMPERATURES...NO SIGNIFICANT CHANGES WERE MADE
TO THE GRIDS THAT WOULD REQUIRE AN UPDATE AT THIS TIME.

SMITH
&&

.AVIATION...
ISSUED 530 PM CST FRI FEB 8 2013

MVFR CIGS ARE EXPECTED TO HOLD ACRS THE AREA THRU AT LEAST SATURDAY
MORNING...WITH SOME OF THE FORECAST SOUNDINGS INDICATING THE POSSIBILITY
THEY WILL BE WITH US THRU 18Z. FOR NOW...WILL START THE TREND OF AT
LEAST BKN CIGS AOA 1500 FEET AROUND 09Z AND THEN SCATTER IT OUR BY
MID MORNING SATURDAY...BEFORE WE SEE AN INCREASE IN HIGH LEVEL CLOUDS
MOVE IN DURING THE AFTERNOON AHEAD OF OUR NEXT WEATHER SYSTEM FOR
SATURDAY NIGHT INTO SUNDAY. LIGHT NE TO EAST WINDS TONIGHT WILL VEER
INTO THE SOUTHEAST LATE TONIGHT AND GRADUALLY INCREASE TO AROUND 10
KTS LATER SATURDAY MORNING INTO THE AFTERNOON HOURS.

SMITH
&&

.PREV DISCUSSION...
ISSUED 242 PM CST FRI FEB 8 2013

HIGH PRESSURE RIDGING CURRENTLY EXTENDING SOUTHWESTWARD FROM LAKE
SUPERIOR TOWARD OKLAHOMA/ARKANSAS. HAVE SEEN SOME PERIODIC
THINNING OF THE STRATOCUMULUS DECK IN THE EASTERN CWA...WITH SOME
MORE SIGNIFICANT EROSION COMING IN FROM WISCONSIN AND SOUTHWEST
MISSOURI. UPPER ANALYSIS AND WATER VAPOR IMAGERY SHOWING A LARGE
CUTOFF LOW DROPPING SOUTHWARD THROUGH CALIFORNIA...AND THIS
FEATURE WILL PLAY A SIGNIFICANT ROLE IN OUR WEATHER DURING THE
WEEKEND.

INITIAL FORECAST CHALLENGE WILL BE WITH THE CLOUD COVER
OVERNIGHT...OTHERWISE THE FOCUS WILL BE ON THE RAIN EXPECTED
DURING THE SECOND HALF OF THE WEEKEND.

SHORT TERM...TONIGHT THROUGH MONDAY...

CLOUD FORECAST WILL BE TRICKY OVERNIGHT. MOST OF THE MODELS ARE
STRUGGLING SOMEWHAT WITH THE EXISTING COVERAGE. THE HRRR...WHICH
IS FAIRLY CLOSE NOW...FILLS ANY GAPS BACK IN THIS EVENING. THE NAM
THINKS ANYTHING WEST OF THE MISSISSIPPI RIVER SHOULD BE CLEAR
ALREADY AND ERODES THE REST OF IT BY EARLY EVENING. THE RAP 925 MB
HUMIDITY APPEARS FAIRLY CLOSE RIGHT NOW AND SHOWS GRADUAL EROSION
FROM THE NORTH AND SOUTH THROUGH THE EVENING...BUT ITS FORECAST
SOUNDINGS SHOW THE INVERSION AT 950 MB REMAINING RATHER TIGHT
THROUGH THE NIGHT. HAVE USED A BLEND OF THE RAP 925 MB HUMIDITY AND
THE MOS GUIDANCE TO COME UP WITH THE SKY GRIDS...WHICH SHOW SKIES
BECOMING PARTLY CLOUDY AFTER MIDNIGHT.

HIGH PRESSURE RIDGE TO CONTINUE PUSHING EASTWARD THROUGH
SATURDAY...WITH WINDS COMING BACK AROUND TO THE SOUTHEAST BY LATE
AFTERNOON. IN THE MEANTIME...THE MODELS ARE IN FAIRLY GOOD
AGREEMENT IN LIFTING THE UPPER LOW INTO SOUTHEAST SOUTH DAKOTA BY
MIDDAY SUNDAY AND THE ASSOCIATED CYCLONE BECOMING VERTICALLY
STACKED DURING THE PROCESS. NOT MUCH CHANGE WAS NEEDED IN THE
GRIDS FOR THE RAIN TIMING LATE SATURDAY NIGHT THROUGH SUNDAY...BUT
HAVE BUMPED UP POP VALUES A LITTLE MORE. THE ASSOCIATED FRONTAL
BOUNDARY AND BACK EDGE OF THE RAIN WILL RAPIDLY SWEEP EASTWARD
DURING SUNDAY EVENING...AND SHOULD BE OUT OF THE AREA BEFORE
TEMPERATURES GET COLD ENOUGH FOR ANY SNOW.

SOUTHERLY WINDS ON SUNDAY WILL GUST TO AROUND 30 MPH OR SO...AND
WITH THE LOW SLOW TO EXIT THE AREA...AM EXPECTING ANOTHER WINDY
DAY ON MONDAY WITH WESTERLY WINDS GUSTING TO 30 MPH OR SO. THE
HIGHER WIND GUSTS ON MONDAY WILL BE NORTH OF I-72...CLOSER TO THE
LOW.

LONG TERM...TUESDAY THROUGH FRIDAY...

THE TRAILING END OF THE FRONT WILL GET HUNG UP ALONG THE GULF
COAST EARLY NEXT WEEK...AND WILL INTERACT WITH AN UPPER TROUGH
MOVING ALONG THE SOUTHERN JET STREAM. THIS WILL EFFECTIVELY CUT
OFF ANY MOISTURE ADVECTION THIS FAR NORTH...WITH DRY CONDITIONS
EXPECTED WITH THE NEXT TROUGH MOVING THROUGH THE NORTHERN STREAM
ON WEDNESDAY. LATE IN THE WEEK...THE LONGER RANGE MODELS BEGIN TO
DIVERGE. THE GFS IS MUCH MORE AGGRESSIVE IN DIGGING A TROUGH OVER
THE CENTRAL CONUS...CUTTING OFF AN UPPER LOW WHICH WOULD DRIFT
INTO ILLINOIS ON SATURDAY. THIS WOULD BE A WETTER AND COLDER
SCENARIO FOR US...VERSUS THE BROADER LONG WAVE TROUGH OF THE
ECMWF. HAVE LIMITED ANY POPS AT THE END OF THE WEEK TO THE SLIGHT
CHANCE RANGE FOR NOW.

GEELHART

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS LINCOLN IL

544 PM CST FRI FEB 8 2013

.DISCUSSION...
ISSUED 242 PM CST FRI FEB 8 2013

INITIAL FORECAST CHALLENGE WILL BE WITH THE CLOUD COVER
OVERNIGHT...OTHERWISE THE FOCUS WILL BE ON THE RAIN EXPECTED
DURING THE SECOND HALF OF THE WEEKEND.

SHORT TERM...TONIGHT THROUGH MONDAY...

LONG TERM...TUESDAY THROUGH FRIDAY...

GEELHART

.AVIATION...
ISSUED 530 PM CST FRI FEB 8 2013

SMITH
&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

206 PM CST THU FEB 7 2013

.MESOSCALE DISCUSSION...
106 PM CST

WE HAVE OPTED TO UPGRADE LAKE AND MCHENRY COUNTIES TO A WINTER
STORM WARNING. SHORT TERM GUIDANCE AND RADAR TRENDS CONTINUES TO
INDICATE HEAVY SNOW RATES IN ACROSS LAKE AND MCHENRY COUNTIES. WE
HAVE HAD REPORTS OF UP TO 2 INCHES IN BEACH PARK WITHIN A COUPLE
HOURS.

A RATHER IMPRESSIVE SHORT WAVE...CURRENTLY DIGGING SOUTHEAST ACROSS
EASTERN NEBRASKA AND INTO WESTERN IOWA...WILL LINK UP WITH A
STRENGTHENING BAND OF MID LEVEL FRONTOGENESIS AND NEGATIVE EPV TO
RESULT IN A BAND OF VERY HEAVY SNOW ACROSS NORTHEASTERN ILLINOIS
THROUGH THE AFTERNOON. THE RAIN SHOULD BEGIN TO QUICKLY TRANSITION
TO
SNOW ACROSS THE CHICAGO AREA...MAINLY ALONG AND NORTH OF THE
INTERSTATE 80 CORRIDOR BY MID AFTERNOON AS COLUMN COOL OCCURS IN
RESPONSE TO THE STRONG FRONTOGENETIC CIRCULATION. SOME OF THE LAST
AMDAR SOUNDINGS OUT OF ORD AND MDW...ONLY INDICATE A MAX TEMP OF
AROUND +1 AROUND 946 MB. SO IT WILL NOT TAKE MUCH TO TIP THE SCALES
IN FAVOR FOR SNOW. ONCE THE SNOW STARTS EXPECT HEAVY SNOW UP TO AN
INCH PER HOUR AT TIMES THROUGH THE EVENING COMMUTE. LESSER AMOUNTS
OF SNOW ARE EXPECTED FARTHER SOUTH TOWARDS THE I 80 CORRIDOR.
HOWEVER...IT MAY TAKE SOME TIME TO CHANGE OVER THIS FAR SOUTH...THUS
1 TO 3 INCHES ARE STILL POSSIBLE IN THIS AREA AS WELL INTO THE
EVENING.

SNOW AMOUNTS OF 2 TO 4 INCHES ARE LIKELY NORTH OF I-88 WITH 4 TO 8
INCHES LIKELY ACROSS LAKE AND MCHENRY COUNTIES.

KJB

.DISCUSSION...
1117 AM CST

HAVE EXPANDED WINTER WEATHER ADVISORY TO INCLUDE WINNEBAGO AND BOONE
COUNTIES AND THE I-88 CORRIDOR.

RECENT AMDAR SOUNDINGS OUT OF ORD/MDW SHOW WARM LAYER UP TO JUST
UNDER +3C BETWEEN 950 AND 900 MB...WHICH LATEST RAP HAS A DECENT
HANDLE ON...RESULTING IN PLAIN RAIN FOR THE CITY AND POINTS SOUTH.
HOWEVER...TEMPERATURES AT THAT LEVEL ACROSS THE NORTHERN TIER OF
COUNTIES ARE DOWN BELOW 1C...ALREADY SUPPORTING A CHANGE TO SNOW
WITH THE CURRENT OB AT KUGN DOWN TO 1/2 MILE VSBY IN SNOW. ALSO
RECEIVED A REPORT OF SNOW STARTING TO ACCUMULATE IN WAUKEGAN AND
ZION IL AND A CHANGEOVER IN CHERRY VALLEY IL. WITH THIS IN
MIND...WILL START RIGHT OUT THE GATE WITH AN ADVISORY FOR WINNEBAGO
BOONE MCHENRY AND LAKE COUNTIES. ALSO BUMPED UP SNOW AMOUNTS TO 2 TO
5 INCHES FOR THE NORTHERN TIER GIVEN THE EARLIER START TIME TO THE
SNOW.

FARTHER TO THE SOUTH...FOR THE I-88 CORRIDOR...THE RAP ALSO SHOWS
THE 950 TO 900MB LAYER QUICKLY COOLING OFF BELOW 0C THROUGH THE
AFTERNOON INDICATIVE OF DYNAMIC COOLING. SO THESE AREAS SHOULD
CHANGE BACK OVER TO SNOW AND SEE DECENT SNOWFALL RATES GIVEN THE
FORCING AT HAND AND THE FACT THAT SURFACE TEMPERATURES EVEN NOW ARE
HOVERING JUST ABOVE FREEZING. FORECAST AMOUNTS WILL BE MARGINAL FOR
AN ADVISORY AT ROUGHLY 2 TO 4 INCHES...BUT SINCE THE RUSH HOUR WILL
BE IMPACTED...FELT IT WAS PRUDENT TO ISSUE ONE STARTING AT 20Z.
INCLUDED OGLE...DEKALB...KANE...DUPAGE AND COOK IN THIS NEW
ADVISORY...BUT KEEP IN MIND THAT THERE WILL LIKELY BE A GRADIENT
FROM NORTH TO SOUTH ACROSS DEKALB THROUGH COOK WHERE THE NORTHERN
PORTIONS WILL BE SEEING THE MORE SIGNIFICANT IMPACTS FROM THE SNOW.

WITH A GOOD FGEN BAND COINCIDENT WITH STRONG LIFT NOTED ON MUCH OF
THE GUIDANCE PIVOTING ACROSS THE CWA AND BEING LOCATED OVER
NORTHEAST ILLINOIS INCLUDING CHICAGO BY THE EARLY EVENING...ALSO
CONCERNED THAT HEAVY SNOWFALL RATES COULD LEAD TO HIGHER TOTALS THAN
THE 3 TO 5 INDICATED IN LAKE AND MCHENRY ALONG THE I-88 CORRIDOR IN
NORTHEAST ILLINOIS. WILL CONTINUE TO ASSESS FOR ANY FURTHER UPDATES
NEEDED. BUT IN SUM...THE AFTERNOON COMMUTE IS LIKELY TO BE PRETTY
MESSY...ESPECIALLY FOR THE NORTHERN PART OF THE METRO.

RC/KJB

//PREV DISCUSSION...
553 AM CST

PRECIPITATION HAS OVERSPREAD NORTHERN IL EARLY THIS MORNING WITH
TEMPERATURES INITIALLY ABOVE FREEZING. AS PRECIPITATION BECAME A
LITTLE STEADIER...TEMPERATURES HAVE FALLEN TO OR A DEGREE BELOW
FREEZING. THIS HAS RESULTED IN FREEZING RAIN BEING REPORTED ACROSS
MANY OF MY FAR NORTHEAST ILLINOIS AREAS...MAINLY ALONG AND NORTH
OF I-88. THUS HAVE OPTED TO HOIST A FREEZING RAIN ADVISORY UNTIL
10 AM...WHICH IS THE TIME THAT TEMPS SHOULD PUSH ABOVE THE
FREEZING POINT WITH RISING DEW POINTS. PRECIPITATION AT THAT POINT
SHOULD TRANSITION OVER TO ALL RAIN.

BEACHLER

//PREV DISCUSSION...
337 AM CST

VERY DYNAMIC AND CHALLENGING WEATHER SYSTEM CONTINUES TO SLIDE EAST
FROM THE CENTRAL PLAINS TODAY. SFC TEMPS HAVE REMAINED MILD
OVERNIGHT IN THE LOW/MID 30S...WITH DEW POINTS HOVERING AROUND 30
DEG IN MANY LOCATIONS. IR IMAGERY INDICATES CONSIDERABLE CLOUD
COVER...WITH THE COLDEST CLOUDS ORIENTED FROM CENTRAL IOWA NORTHEAST
THROUGH CENTRAL WISCONSIN INTO NORTHERN LOWER MICHIGAN. EARLY THIS
MORNING CONSIDERABLE LIGHTING WAS NOTED ACROSS KANSAS AND CENTRAL
MISSOURI...INDICATING THAT CONSIDERABLE LIFT/UPGLIDE WAS OCCURRING
IN THIS AREA. IN ADDITION TO THE THUNDERSTORM ACTIVITY UPSTREAM OF
NORTHERN IL/NORTHWEST IN...WAS TEMPS IN THE LOW/MID 40S ACROSS
SOUTH CENTRAL IOWA EARLY THIS MORNING. WARM/MOIST AIR CONTINUES TO
BE
TRANSPORTED NORTH FROM THE WESTERN GULF OF MEXICO AHEAD OF THE
SHORTWAVE...WHICH WILL PLAY A LARGE ROLE IN KEEPING THE BULK OF THE
PRECIP AT THE ONSET AS LIQUID. HOWEVER...A FEW SITES CONTINUE TO
SHOW TEMPS AROUND THE FREEZING MARK. THUS IT IS CONCEIVABLE THAT A
BRIEF PERIOD OF FZRA MAY OCCUR EARLY THIS MORNING. REGIONAL RADAR
MOSAIC EARLY THIS MORNING SHOWS A SLUG OF PRECIP SLIDING EAST ACROSS
NORTH CENTRAL IL/FAR WESTERN IL...HOWEVER SFC OBS INDICATE THIS IS
VERY LIGHT AND IN SOME LOCATIONS NOT REACHING THE GROUND.

THE FOCUS TURNS TOWARDS WHAT WILL TRANSPIRE BY MID-MORNING
ACROSS THE CWFA. THE GREATEST FOCUS FOR P-TYPE CONCERNS CONTINUES TO
BE ALONG AND NORTH OF A ROCKFORD TO WAUKEGAN LINE. GUIDANCE HAS
STRUGGLED WITH THE ANALYSIS AND FORECAST FIELDS OF SFC TEMPS WITH A
COLD BIAS...THUS HAVE OPTED TO MAINTAIN A SLIGHTLY WARMER TREND.
SREF 2M TEMP PLUMES CONTINUE TO SHOW MINIMAL SPREAD WITH THE TEMPS
TDY...HOWEVER APPROXIMATELY 2-3 DEG TOO COOL. CONSIDERABLE
CORRECTIONS CONTINUE TO TAKE PLACE EVEN AT HOUR ZERO AHEAD OF THIS
SYSTEM...HOWEVER SOME CONSISTENCY HAS BEEN NOTED IN THE LACK OF AN
EASTERLY LLVL JET AT 850MB. THE U-WIND ANOMS HAVE CONTINUED TO BE
POSITIVE FROM THE SW AT 20-30KTS...INDICATING AN EFFICIENT TRANSPORT
OF PARCELS FROM SW TO NE. THE WAVE REMAINS OPEN...HOWEVER SHOULD
BEGIN TO AMPLIFY WITH TIME. THE PATH OF THE 850/925MB LOWS ARE
SIMILAR AMONGST THE EC/NAM IN TIME PUSHING FROM WEST TO EAST ACROSS
THE NORTHERN THIRD OF THE CWFA MIDDAY. JUST TO THE NORTH OF THIS
PATH APPEARS TO BE THE FAVORED REGION FOR P-TYPE CONCERNS AND
ACCUMULATING SNOW POTENTIAL. THE 540M THICKNESS LINE IS JUST NORTH
OF RFD...STRETCHING SLIGHTLY SOUTHEAST OF WAUKEGAN FOR MUCH OF THE
DAY.

AS MOISTURE CONTINUES TO FEED NORTHEAST AHEAD OF THE 500MB TROUGH
AXIS...AND PRECIP OVERSPREADS THE AREA...EXPECT DYNAMIC COOLING TO
SLOWLY OCCUR ACROSS THE FAR NORTHERN CWFA INTO SOUTHERN WISC. THIS
SHOULD ALLOW A SLOW TRANSITION OVER TO A RAIN/SNOW/SLEET MIX. AT
THIS TIME ACCUMS HAVE FOCUSED FURTHER NORTH ACROSS THE STATE LINE IN
SOUTHERN WISC. SREF PLUMES FOR RFD SUGGEST A 70% PROB OF FZRA/RA AT
ONSET TRENDING TO RA...THEN ARND 21-00Z 80% LIKELIHOOD OF SN.
FURTHER EAST AT UGN THE PROB OF SN IS SLIGHTLY HIGHER AND EARLIER.
THEN BY 00Z PRECIP TYPE SHUD SWITCH OVER TO ALL SN FROM WEST TO EAST
AS COOLER AIR STEADILY ADVECTS INTO THE CWFA. SOUNDINGS ARE NOT MUCH
ASSISTANCE AT THIS TIME...GIVEN THE POOR INITIALIZATION.

SNOW ACCUMS WILL ALSO BE A CHALLENGE...IF INDEED IT DOES SNOW AND
CAN ACCUMULATE. WITH THE HIGH DEW PTS HOVERING ARND THE FREEZING
MARK IT WILL BECOME A CHALLENGE. AT THIS TIME HAVE OPTED TO TRIM
BACK SNOW ACCUMS TO A 1-2" RANGE...WITH A FOCUS ACROSS MCHENRY/LAKE
COUNTIES. HOWEVER IF THE DYNAMIC COOLING CAN TAKE PLACE
EARLIER...AND THE FGEN BAND COULD CRANK OUT HIGHER ACCUMS. VERY
DIFFICULT TO PULL THE CURRENT ADVISORY...AND AT THE SAME TIME
DIFFICULT TO EXPAND THE ADVISORY FURTHER WEST. SO AT THIS TIME WILL
LEAVE HEADLINES AS IS.

CONFIDENCE IN TEMPERATURES...HIGH.

CONFIDENCE IN ACCUMULATING SNOWFALL...LOW.

CONFIDENCE IN PRECIP CHANGE TIMING...LOW.

TONIGHT THROUGH FRIDAY...

500MB TROUGH AXIS PIVOTS OVERHEAD AND PUSHES NORTHEAST TOWARDS THE
EASTERN GREAT LAKES EARLY FRI. 850MB/SFC LOW CONTINUES TO DEVELOP
DOWNSTREAM OF OUR AREA...WITH A DRY WEDGE ADVERTISED BY GUIDANCE
ARRIVING ARND 06-09Z. THIS SHUD AID IN SHUTTING OFF THE
PRECIP...WHICH BY 00Z FRI SHUD BE ALMOST ALL LGT SNOW. SOME
WRAP-AROUND MOISTURE CONTINUES TO BE NOTED BY THE OPERATIONAL
SOLUTIONS...THUS HAVE CONTINUED MENTION OF SOME LIGHT SNOW OR
FLURRIES ACROSS ALONG THE BACKSIDE OF THE BETTER PRECIP SHIELD.

ANTI-CYCLONIC FLOW QUICKLY BUILDS IN FOR FRI...ERODING ANY REMAINING
LLVL MOISTURE. WINDS TURN NORTHEAST FOR A PERIOD FRI WHICH COULD
PULL SOME MOISTURE OFF OF LAKE MICHIGAN...ALTHOUGH THIS LOOKS VERY
MARGINAL. THUS HAVE CONTINUE WITH A DRY FORECAST. 850MB THERMAL
TROUGH REMAINS OVERHEAD AT -4 TO -6 DEG C FRI KEEPING AFTN MAX TEMPS
MAINLY IN THE LOW/MID 30S. THE FLOW REMAINS PROGRESSIVE WITH HEIGHTS
INCREASING UPSTREAM OF THE CWFA FRI AFTN/EVE. PRIOR TO THE MID-LVL
RIDGING ARRIVING...THE SFC RIDGE WILL BECOME CENTERED OVER THE CWFA
FRI NIGHT. THIS SHUD ALLOW SFC TEMPS TO RADIATE INTO THE TEENS/LOW
20S. LIGHT WINDS AND RECENT RAINFALL FROM THURSDAY COULD SET THE
STAGE FOR PATCHY FOG DEVELOPING FRI NIGHT.

CONFIDENCE...HIGH.

SATURDAY THROUGH WEDNESDAY...
500MB RIDGING PUSHES OVERHEAD FOR SAT/SUN AS A DEEP TROUGH CONTINUES
TO DIG INTO THE FOUR-CORNERS REGION. AS THIS UPSTREAM TROUGH BECOMES
AMPLIFIED...THE WESTERN GULF OF MEXICO WILL OPEN UP WITH ABUNDANT
MOISTURE STREAMING NORTH ACROSS THE OZARKS INTO THE WESTERN GREAT
LAKES SUN. GUIDANCE HAS CONTINUED TO INDICATE THAT AFTER A DRY
SAT...SUN WILL BE WET. THIS SYSTEM ON SUN APPEARS TO BE VERY ROBUST
BASED ON LATEST GUIDANCE...WITH MINIMAL SPREAD BEING NOTED AMONGST
THE ENSEMBLE MEMBERS. AT THIS TIME HAVE HELD OFF ON INCLUDING
CONVECTION IN THE FORECAST FOR SUN...WOULDN/T BE SURPRISED TO SEE
THIS ADDED OVER TIME. TEMPS SUN SURGE AHEAD OF THE SYSTEM...WITH
MID/UPR 40S LOOKING PROBABLE. COULD EVEN SEE TEMPS TOUCH 50 DEG IN A
FEW LOCATIONS OF OUR SOUTHERN CWFA.

THEN COOLER AIR WILL RETURN FOR THE START OF NEXT WEEK...WITH TEMPS
RETURNING TO SEASONAL CONDITIONS IN THE 30S.

CONFIDENCE...HIGH.

BEACHLER

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 20Z...

* RAIN THROUGH MIDDAY...MIXING/CHANGING TO SNOW BY EVENING.

* SNOW EARLY EVENING DIMINISHING TO FLURRIES OR A FEW SNOW
SHOWERS LATE EVENING.

* LIGHT WINDS GRADUALLY BACKING FROM OUT OF THE SE TO E LATER
AFTERNOON AND EARLY EVENING...THEN TO OUT OF THE NE AND N LATE
EVENING AND INCREASING TO 10-15KT OVERNIGHT.

* CEILINGS LOWERING TO BELOW 010 BY EARLY EVENING THEN PERIODS OF
CEILINGS BELOW 007 WITH THE HEAVIER SNOWFALL DURING THE EARLY
EVENING.

* VISIBILITIES OF 1-2SM IN RA...SN...BR TIL LATER EVENING THEN
IMPROVING TO P6SM LATE TONIGHT.

TRS

//DISCUSSION...UPDATED 18Z...

A NE TO SW ORIENTED UPPER TROUGH EXTENDS FROM WESTERN LAKE
SUPERIOR ACROSS IA TO N TX AT MIDDAY. MODELS HAVE IT PROGRESSING
TO EASTERN LAKE SUPERIOR...SE WI AND CENTRAL IL BY 08.06Z. IR
SATELLITE LOOP SHOWS A WELL DEFINED BAROCLINIC LEAF FROM LAKE MI
AND WI ACROSS TO EASTERN IA WITH TWO AREAS OF VERY COLD TOPS. ONE
WAS OVER E CENTRAL IA TO SE WI AND THE OTHER OVER W CENTRAL WI
TO FAR SE MN. THE COLD CLOUD TOPS WERE AHEAD OF A SHORT WAVE
CURRENTLY OVER IA AND LIFTING NE. THIS FEATURE IS EXPECTED TO
MOVE OVER THE KORD AND KMDW 22-23Z WITH THE UPPER TROUGH AXIS
CROSSING THE AREA MOVE OVER THE LOCAL AREA DURING THE EVENING.

ENHANCED LIFT IN THE MID LEVELS OUT AHEAD OF THE APPROACHING
SHORT WAVE AND THE UPPER TROUGH IS ENHANCING PRECIP PRODUCTION.
DYNAMIC COOLING OF THE LOWER LEVELS HAS CHANGED RAIN BACK TO SNOW
ACROSS FAR SOUTHERN WI AND FAR NE AND N CENTRAL IL. WITH THE AREA
OF GREATEST MID LEVEL ISENTROPIC LIFT AND FRONTOGENESIS SHIFTS
FURTHER E TO OVER NE IL DURING THE LATER AFTERNOON THE ENHANCED
PRECIPITATION AS WELL AS THE SWITCH-OVER TO SNOW IS EXPECTED TO
ALSO SHIFT E AND OVER THE LOCAL AREA THEN TAPER OFF TO SCATTERED
SNOW SHOWERS OR FLURRIES AFTER THE UPPER TROUGH MOVE E OF THE AREA
DURING THE EVENING.

A SURFACE LOW RELATED TO THIS SYSTEM WAS IN FAR SE IA AT MIDDAY
AND IS FORECAST TO MOVE E ACROSS CENTRAL IL DURING THE LATER
AFTERNOON...AND ACROSS NORTHERN IN DURING THE EVENING. IN RESPONSE
SURFACE WINDS WILL BACK FROM SE TO NE DURING THE AFTERNOON AND
BACK FURTHER TO OUT OF THE N DURING THE EVENING.

TRS

//ORD AND MDW CONFIDENCE...UPDATED 20Z...

* HIGH CONFIDENCE IN PRECIP OCCURRENCE AND TYPE THROUGH
AFTERNOON.

* HIGH CONFIDENCE IN WIND TRENDS REST OF DAY AND THIS EVENING.

* MEDIUM CONFIDENCE IN TIMING OF CHANGE/MIX OF RAIN MID TO LATE
AFTERNOON AND TEN TO ALL SNOW BY EARLY EVENING.

* MEDIUM CONFIDENCE IS VIS TRENDS.

* LOW CONFIDENCE IN TIMING OR EXTENT OF LIFR CIGS.

TRS

//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 16Z...

FRIDAY NIGHT...VFR. WX NIL.

SATURDAY...VFR. WX NIL.

SUNDAY...RAIN LIKELY. IFR CONDITIONS POSSIBLE.

MONDAY...CHANCE OF RAIN AND MVFR CIGS EARLY...THEN VFR.

TUESDAY...VFR. WX NIL.

WEDNESDAY...VFR. WX NIL.

KREIN

.MARINE...
117 PM CST

WINDS VARY ACROSS THE LAKE EARLY THIS AFTERNOON AS A TROUGH OF LOW
PRESSURE CONTINUES TO MOVE NORTHEAST ACROSS PORTIONS OF THE MID
MISSISSIPPI VALLEY AND SOUTHERN PLAINS. THIS LOW WILL CONTINUE TO
LIFT NORTHEAST TOWARDS THE OHIO VALLEY TONIGHT WHILE A RIDGE OF
HIGH PRESSURE EXTENDING FROM ONTARIO EAST TO QUEBEC SLOWLY BUILDS
SOUTHEAST. AS THIS OCCURS...EXPECT THE PRESSURE GRADIENT TO
TIGHTEN WITH WINDS INCREASING INITIALLY OUT OF THE EAST BUT THEN
SHIFTING TO MORE OF A NORTHERLY WIND TONIGHT. THESE NORTHERLY
WINDS TO 30 KT WILL CONTINUE THROUGH MOST OF FRIDAY BEFORE SLOWLY
DIMINISHING AS THIS LOW EXITS TO THE EAST AND HIGH PRESSURE BUILDS
ACROSS THE LAKE. THEN EXPECT WINDS TO CONTINUE DIMINISHING INTO
FRIDAY NIGHT AND REMAINING ON THE LIGHTER SIDE SATURDAY BEFORE
PICKING UP OUT OF THE SOUTH THROUGH THE REMAINDER OF THE DAY
SATURDAY...REMAINING SOUTHERLY THROUGH THE REST OF THE WEEKEND.

RODRIGUEZ

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ005-ILZ006 UNTIL MIDNIGHT FRIDAY.

WINTER WEATHER ADVISORY...ILZ003-ILZ004 UNTIL 9 PM THURSDAY.

WINTER WEATHER ADVISORY...ILZ008-ILZ011-ILZ012-ILZ013-ILZ014
UNTIL 9 PM THURSDAY.

IN...NONE.
LM...NONE.
&&

AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

148 PM CST THU FEB 7 2013

.MESOSCALE DISCUSSION...
106 PM CST

SNOW AMOUNTS OF 2 TO 4 INCHES ARE LIKELY NORTH OF I-88 WITH 4 TO 8
INCHES LIKELY ACROSS LAKE AND MCHENRY COUNTIES.

KJB

.DISCUSSION...
1117 AM CST

HAVE EXPANDED WINTER WEATHER ADVISORY TO INCLUDE WINNEBAGO AND BOONE
COUNTIES AND THE I-88 CORRIDOR.

RC/KJB

//PREV DISCUSSION...
553 AM CST

BEACHLER

//PREV DISCUSSION...
337 AM CST

CONFIDENCE IN TEMPERATURES...HIGH.

CONFIDENCE IN ACCUMULATING SNOWFALL...LOW.

CONFIDENCE IN PRECIP CHANGE TIMING...LOW.

TONIGHT THROUGH FRIDAY...

CONFIDENCE...HIGH.

THEN COOLER AIR WILL RETURN FOR THE START OF NEXT WEEK...WITH TEMPS
RETURNING TO SEASONAL CONDITIONS IN THE 30S.

CONFIDENCE...HIGH.

BEACHLER

//ORD AND MDW CONCERNS...UPDATED 18Z...

* RAIN THROUGH MIDDAY...MIXING/CHANGING TO SNOW BY EVENING.

* SNOW EARLY EVENING DIMINISHING TO FLURRIES OR A FEW SNOW
SHOWERS LATE EVENING.

* LIGHT WINDS GRADUALLY BACKING FROM OUT OF THE SE TO E LATER
AFTERNOON AND EARLY EVENING...THEN TO OUT OF THE NE AND N LATE
EVENING AND INCREASING TO 10-15KT OVERNIGHT.

* CEILINGS LOWERING TO BELOW 010 BY EARLY EVENING THEN PERIODS OF
CEILINGS BELOW 007 WITH THE HEAVIER SNOWFALL DURING THE EARLY
EVENING.

* VISIBILTIES OF 1-2SM IN RA...SN...BR TIL LATER EVENING THEN
IMPROVING TO P6SM LATE TONIGHT.

TRS

//DISCUSSION...UPDATED 18Z...

A NE TO SW ORIENTED UPPER TROUGH EXTENDS FROM WESTERN LAKE
SUPERIOR ACROSS IA TO N TX AT MIDDAY. MODELS HAVE IT PROGESSING
TO EASTERN LAKE SUPERIOR...SE WI AND CENTRAL IL BY 08.06Z. IR
SATELLITE LOOP SHOWS A WELL DEFINED BAROCLYNIC LEAF FROM LAKE MI
AND WI ACROSS TO EASTERN IA WITH TWO AREAS OF VERY COLD TOPS. ONE
WAS OVER E CENTRAL IA TO TOSE WI AND THE OTHER OVER W CENTRAL WI
TO FAR SE MN. THE COLD CLOUD TOPS WERE AHEAD OF A SHORT WAVE
CURRENTLY OVER IA AND LIFTING NE. THIS FEATURE IS EXPECTED TO
MOVE OVER THE KORD AND KMDW 22-23Z WITH THE UPPER TROUGH AXIS
CORSSING THE AREA MOVE OVER THE LOCAL AREA DURING THE EVENING.

ENHANCED LIFT IN THE MID LEVELS OUT AHEAD OF THE APPROACHING
SHORT WAVE AND THE UPPER TROUGH IS ENHANCING PRECIP PRODUCTION.
DYNAMIC COOLING OF THE LOWER LEVELS HAS CHANGED RAIN BACK TO SNOW
ACROSS FAR SOUTHERN WI AND FAR NE AND N CENTRAL IL. WITH THE AREA
OF GREATEST MID LEVEL ISENTROPIC LIFT AND FRONTOGENESIS SHIFTS
FUTHER E TO OVER NE IL DURING THE LATER AFTERNOON THE ENHANCED
PRECIPITATION AS WELL AS THE SWITCH-OVER TO SNOW IS EXPECTED TO
ALSO SHIFT E AND OVER THE LOCAL AREA THEN TAPER OFF TO SCATTERED
SNOW SHOWERS OR FLURRIES AFTER THE UPPER TROUGH MOVE E OF THE AREA
DURING THE EVENING.

A SURFACE LOW RELATED TO THIS SYSTEM WAS IN FAR SE IA AT MIDDAY
AND IS FORECAST TO MOVE E ACROSS CENTRAL IL DURING THE LATER
AFTERNOON...AND ACROSS NORTHERN IN DURIN THE EVENING. IN RESPONSE
SURFACE WINDS WILL BACK FROM SE TO NE DURING THE AFRTERNOON AND
BACK FURTHER TO OUT OF THE N DURING THE EVENING.

TRS

//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* HIGH CONFIDENCE IN PRECIP OCCURRENCE AND TYPE THROUGH
AFTERNOON.

* HIGH CONFIDENCE IN WIND TRENDS REST OF DAY AND THIS EVENING.

* MEDIUM CONFIDENCE IN TIMING OF CHANGE/MIX OF RAIN MID TO LATE
AFTERNOON AND TEN TO ALL SNOW BY EARLY EVENING.

* MEDIUM CONFIDENCE IS VIS TRENDS.

* LOW CONFIDENCE IN TIMING OR EXTENT OF LIFR CIGS.

TRS

//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 16Z...

FRIDAY NIGHT...VFR. WX NIL.

SATURDAY...VFR. WX NIL.

SUNDAY...RAIN LIKELY. IFR CONDITIONS POSSIBLE.

MONDAY...CHANCE OF RAIN AND MVFR CIGS EARLY...THEN VFR.

TUESDAY...VFR. WX NIL.

WEDNESDAY...VFR. WX NIL.

KREIN

.MARINE...
117 PM CST

RODRIGUEZ

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ005-ILZ006 UNTIL MIDNIGHT FRIDAY.

WINTER WEATHER ADVISORY...ILZ003-ILZ004 UNTIL 9 PM THURSDAY.

WINTER WEATHER ADVISORY...ILZ008-ILZ011-ILZ012-ILZ013-ILZ014
UNTIL 9 PM THURSDAY.

IN...NONE.
LM...NONE.
&&

AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

118 PM CST THU FEB 7 2013

.MESOSCALE DISCUSSION...
106 PM CST

A RATHER IMPRESSIVE SHORT WAVE...CURRENTLY DIGGING SOUTHEAST ACROSS
EASTERN NEBRASKA AND INTO WESTERN IOWA...WILL LINK UP WITH A
STRENGTHENING BAND OF MID LEVEL FRONTOGENESIS AND NEGATIVE EPV TO
RESULT IN A BAND OF VERY HEAVY SNOW ACROSS NORTHEASTERN ILLINOIS
THROUGH THE AFTERNOON. THE RAIN SHOULD BEGIN TO QUICKLY TRANSITION TO
SNOW ACROSS THE CHICAGO AREA...MAINLY ALONG AND NORTH OF THE
INTERSTATE 80 CORRIDOR BY MID AFTERNOON AS COLUMN COOL OCCURS IN
RESPONSE TO THE STRONG FRONTOGENETIC CIRCULATION. SOME OF THE LAST
AMDAR SOUNDINGS OUT OF ORD AND MDW...ONLY INDICATE A MAX TEMP OF
AROUND +1 AROUND 946 MB. SO IT WILL NOT TAKE MUCH TO TIP THE SCALES
IN FAVOR FOR SNOW. ONCE THE SNOW STARTS EXPECT HEAVY SNOW UP TO AN
INCH PER HOUR AT TIMES THROUGH THE EVENING COMMUTE. LESSER AMOUNTS
OF SNOW ARE EXPECTED FARTHER SOUTH TOWARDS THE I 80 CORRIDOR.
HOWEVER...IT MAY TAKE SOME TIME TO CHANGE OVER THIS FAR SOUTH...THUS
1 TO 3 INCHES ARE STILL POSSIBLE IN THIS AREA AS WELL INTO THE
EVENING.

SNOW AMOUNTS OF 2 TO 4 INCHES ARE LIKELY NORTH OF I-88 WITH 4 TO 8
INCHES LIKELY ACROSS LAKE AND MCHENRY COUNTIES.

KJB

.DISCUSSION...
1117 AM CST

HAVE EXPANDED WINTER WEATHER ADVISORY TO INCLUDE WINNEBAGO AND BOONE
COUNTIES AND THE I-88 CORRIDOR.

RC/KJB

//PREV DISCUSSION...
553 AM CST

BEACHLER

//PREV DISCUSSION...
337 AM CST

VERY DYNAMIC AND CHALLENGING WEATHER SYSTEM CONTINUES TO SLIDE EAST
FROM THE CENTRAL PLAINS TODAY. SFC TEMPS HAVE REMAINED MILD
OVERNIGHT IN THE LOW/MID 30S...WITH DEW POINTS HOVERING AROUND 30
DEG IN MANY LOCATIONS. IR IMAGERY INDICATES CONSIDERABLE CLOUD
COVER...WITH THE COLDEST CLOUDS ORIENTED FROM CENTRAL IOWA NORTHEAST
THROUGH CENTRAL WISCONSIN INTO NORTHERN LOWER MICHIGAN. EARLY THIS
MORNING CONSIDERABLE LIGHTING WAS NOTED ACROSS KANSAS AND CENTRAL
MISSOURI...INDICATING THAT CONSIDERABLE LIFT/UPGLIDE WAS OCCURRING
IN THIS AREA. IN ADDITION TO THE THUNDERSTORM ACTIVITY UPSTREAM OF
NORTHERN IL/NORTHWEST IN...WAS TEMPS IN THE LOW/MID 40S ACROSS
SOUTH CENTRAL IOWA EARLY THIS MORNING. WARM/MOIST AIR CONTINUES TO BE
TRANSPORTED NORTH FROM THE WESTERN GULF OF MEXICO AHEAD OF THE
SHORTWAVE...WHICH WILL PLAY A LARGE ROLE IN KEEPING THE BULK OF THE
PRECIP AT THE ONSET AS LIQUID. HOWEVER...A FEW SITES CONTINUE TO
SHOW TEMPS AROUND THE FREEZING MARK. THUS IT IS CONCEIVABLE THAT A
BRIEF PERIOD OF FZRA MAY OCCUR EARLY THIS MORNING. REGIONAL RADAR
MOSAIC EARLY THIS MORNING SHOWS A SLUG OF PRECIP SLIDING EAST ACROSS
NORTH CENTRAL IL/FAR WESTERN IL...HOWEVER SFC OBS INDICATE THIS IS
VERY LIGHT AND IN SOME LOCATIONS NOT REACHING THE GROUND.

CONFIDENCE IN TEMPERATURES...HIGH.

CONFIDENCE IN ACCUMULATING SNOWFALL...LOW.

CONFIDENCE IN PRECIP CHANGE TIMING...LOW.

TONIGHT THROUGH FRIDAY...

CONFIDENCE...HIGH.

THEN COOLER AIR WILL RETURN FOR THE START OF NEXT WEEK...WITH TEMPS
RETURNING TO SEASONAL CONDITIONS IN THE 30S.

CONFIDENCE...HIGH.

BEACHLER

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 16Z...

* RAIN THROUGH THE REST OF THE DAY...MIXING/CHANGING TO SNOW
EARLY TO MID EVENING.

* GRADUALY BACKING OF GENERALLY 7 TO 9 KT WINDS FROM SE TO NE
TODAY AND TO N AND NW TONIGHT. WINDS TO INCREASE SOMEWHAT
TONIGHT...AVERAGING 9 TO 12 KT BY LATE EVENING.

* VFR CIGS WITH AREAS OF MVFR LOWERING IFR BY EARLY
AFTERNOON...WITH POSSIBLR LIFR CIGS LATER AFTERNOON INTO THE
NIGHT.

* REDUCED VISIBILITY...GENERALLY 2 TO 4SM REST OF DAY AND THROUGH
MUCH/ALL OF THE EVENING.

KREIN

//DISCUSSION...UPDATED 15Z...

THE NE TO SW ORIENTED UPPER TROUGH EXTENDED FROM WESTERN ONTARIO
TO N TX AT MID MORNING AND FROM WHAT NEW MODEL OUTPUT IS
AVAILABLE AT THIS TIME HAS THE TROUGH AXIS REACHING A LINE ACROSS
LAKE SUPERIOR SW TO OK. IR SATELLITE SHOWS THE CLOUDS ALONG AND
AHEAD OF THE UPPER TROUGH...WHERE ENHANCED UVV IS OCCURRING TO BE
OCCURRING...CLOUD TOPS WERE COOLING AND EXPANDING IN COVERAGE.
THE LOOP OF THE NATIONAL MOSAIC OF RADAR REFLECTIVITY WAS SHOWING
RAIN FROM EASTERN KS...NW MO AND SE IA TO W CENTRAL AND NORTHERN
IL AND SOUTHERN WI.

LOW LEVEL TEMPERATURES HAVE RISEN A COUPLE DEGREES F DURING THE
FIRST PART OF THE MORNING AS WAA CONTINUES AHEAD OF A SURFACE LOW
CURRENTLY IN CENTRAL...AND WILL PERSIST MUCH OF THE AS THE LOW
MOVES E ACROSS NORTHERN IL TO NW IN. THIS WILL KEEP PRECIP ALL
RAIN AT AND AROUND THE KLOT AND KMDW AREAS FOR THE THE REST OF
THE DAY.

AS THE SURFACE LOW MOVES ACROSS CENTRAL IL DURING THE AFTERNOON
WINDS WILL BACK FROM SE TO E AROUND MID AFTERNOON AND TO NE BY
08.00Z. MIXING/CHANGING TO SNOW WILL NOT START TO OCCUR LOCALLY
TIL EARLY EVENING WITH JUST SNOW OVERNIGHT AS THE MID AND UPPER
TROUGHS PASS E ACROSS THE LOCAL AREA AND DEEPER...STRONGER CAA
SETS IN ACROSS THE REGION.

TRS

//PREVIOUS DISCUSSION...UPDATED 12Z...

AT 11Z...TEMPERATURES ACROSS NRN IL/NWRN IN WERE 32-36F WITH EVEN
WARMER AIR OVER UPSTREAM OVER CNTRL IL AND INTO MO. WITH THE
TEMPERATURES HOVERING NEAR THE FREEZING POINT...IN LOCATIONS WHERE
PCPN HAS NOT ALREADY BEGUN...THE INITIAL ONSET OF PCPN WILL START
AS SOME LIGHT SLEET...BUT SHOULD QUICKLY CHANGE OVER TO RAIN AND
FREEZING RAIN.

THE WARMER AIR ALOFT OVER THE COOLER AIR AT THE SFC SHOULD WORK
DOWN TO THE SFC BY ARND 14Z...ENDING ANY ADDITIONAL FREEZING RAIN
POTENTIAL. THE RAIN SHOULD PERSIST THROUGH THE REMAINDER OF THE
AFTERNOON...BUT AS WINDS GRADUALLY BECOME EASTERLY...EXPECT THAT
CIGS WILL LOWER TO IFR...AND POSSIBLY LIFR...LEVELS BY THIS
AFTERNOON. THE RAIN AND IFR/LIFT CIGS WILL PERSIST UNTIL LATER
THIS EVENING WHEN A SFC LOW WILL PASS JUST SOUTH OF THE
TERMINALS...TURNING WINDS NLY-NWLY...DRAWING COOLER AIR INTO THE
AREA AND CHANGING THE RAIN OVER TO SNOW. LIGHT SNOW SHOULD PERSIST
FOR A SHORT TIME...UNTIL TAPERING OFF TO FLURRIES. AS THE COOLER
AIR WORKS INTO THE AREA...CIGS SHOULD SLOWLY IMPROVE TO MVFR
OVERNIGHT TONIGHT AND INTO TOMORROW MORNING.

KREIN

//ORD AND MDW CONFIDENCE...UPDATED 16Z...

* HIGH CONFIDENCE IN PRECIP OCCURRENCE AND TYPE THROUGH
AFTERNOON.

* HIGH CONFIDENCE IN WIND TRENDS REST OF DAY AND THIS EVENING.

* MEDIUM CONFIDENCE IN TIMING OF CHANGE/MIX OF RAIN AND DURING
FIRST PART OF EVENING...THEN TO ALL SNOW OVERNIGHT.

* MEDIUM CONFIDENCE IS VIS TRENDS.

* LOW CONFIDENCE IN TIMING OR EXTENT OF LIFR CIGS.

TRS

//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 16Z...

FRIDAY NIGHT...VFR. WX NIL.

SATURDAY...VFR. WX NIL.

SUNDAY...RAIN LIKELY. IFR CONDITIONS POSSIBLE.

MONDAY...CHANCE OF RAIN AND MVFR CIGS EARLY...THEN VFR.

TUESDAY...VFR. WX NIL.

WEDNESDAY...VFR. WX NIL.

KREIN

.MARINE...
117 PM CST

RODRIGUEZ

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ005-ILZ006 UNTIL MIDNIGHT FRIDAY.

WINTER WEATHER ADVISORY...ILZ003-ILZ004 UNTIL 9 PM THURSDAY.

WINTER WEATHER ADVISORY...ILZ008-ILZ011-ILZ012-ILZ013-ILZ014
UNTIL 9 PM THURSDAY.

IN...NONE.
LM...NONE.
&&

AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

106 PM CST THU FEB 7 2013

.MESOSCALE DISCUSSION...
106 PM CST

A RATHER IMPRESSIVE SHORT WAVE...CURRENTLY DIGGING SOUTHEAST ACROSS
EASTERN NEBRASKA AND INTO WESTERN IOWA...WILL LINK UP WITH A
STRENGTHENING BAND OF MID LEVEL FRONTOGENESIS AND NEGATIVE EPV TO
RESULT IN A BAND OF VERY HEAVY SNOW ACROSS NORTHEASTERN ILLINOIS
THROUGH THE AFTERNOON. THE RAIN SHOULD BEGIN TO QUICKLY TRANSITION TO
SNOW ACROSS THE CHICAGO AREA...MAINLY ALONG AND NORTH OF THE
INTERSTATE 80 CORRIDOR BY MID AFTERNOON AS COLUMN COOL OCCURS IN
RESPONSE TO THE STRONG FRONTOGENETIC CIRCULATION. SOME OF THE LAST
AMDAR SOUNDINGS OUT OF ORD AND MDW...ONLY INDICATE A MAX TEMP OF
AROUND +1 AROUND 946 MB. SO IT WILL NOT TAKE MUCH TO TIP THE SCALES
IN FAVOR FOR SNOW. ONCE THE SNOW STARTS EXPECT HEAVY SNOW UP TO AN
INCH PER HOUR AT TIMES THROUGH THE EVENING COMMUTE. LESSER AMOUNTS
OF SNOW ARE EXPECTED FARTHER SOUTH TOWARDS THE I 80 CORRIDOR.
HOWEVER...IT MAY TAKE SOME TIME TO CHANGE OVER THIS FAR SOUTH...THUS
1 TO 3 INCHES ARE STILL POSSIBLE IN THIS AREA AS WELL INTO THE
EVENING.

SNOW AMOUNTS OF 2 TO 4 INCHES ARE LIKELY NORTH OF I-88 WITH 4 TO 8
INCHES LIKELY ACROSS LAKE AND MCHENRY COUNTIES.

KJB

.DISCUSSION...
1117 AM CST

HAVE EXPANDED WINTER WEATHER ADVISORY TO INCLUDE WINNEBAGO AND BOONE
COUNTIES AND THE I-88 CORRIDOR.

RC/KJB

//PREV DISCUSSION...
553 AM CST

BEACHLER

//PREV DISCUSSION...
337 AM CST

VERY DYNAMIC AND CHALLENGING WEATHER SYSTEM CONTINUES TO SLIDE EAST
FROM THE CENTRAL PLAINS TODAY. SFC TEMPS HAVE REMAINED MILD
OVERNIGHT IN THE LOW/MID 30S...WITH DEW POINTS HOVERING AROUND 30
DEG IN MANY LOCATIONS. IR IMAGERY INDICATES CONSIDERABLE CLOUD
COVER...WITH THE COLDEST CLOUDS ORIENTED FROM CENTRAL IOWA NORTHEAST
THROUGH CENTRAL WISCONSIN INTO NORTHERN LOWER MICHIGAN. EARLY THIS
MORNING CONSIDERABLE LIGHTING WAS NOTED ACROSS KANSAS AND CENTRAL
MISSOURI...INDICATING THAT CONSIDERABLE LIFT/UPGLIDE WAS OCCURRING
IN THIS AREA. IN ADDITION TO THE THUNDERSTORM ACTIVITY UPSTREAM OF
NORTHERN IL/NORTHWEST IN...WAS TEMPS IN THE LOW/MID 40S ACROSS
SOUTH CENTRAL IOWA EARLY THIS MORNING. WARM/MOIST AIR CONTINUES TO BE
TRANSPORTED NORTH FROM THE WESTERN GULF OF MEXICO AHEAD OF THE
SHORTWAVE...WHICH WILL PLAY A LARGE ROLE IN KEEPING THE BULK OF THE
PRECIP AT THE ONSET AS LIQUID. HOWEVER...A FEW SITES CONTINUE TO
SHOW TEMPS AROUND THE FREEZING MARK. THUS IT IS CONCEIVABLE THAT A
BRIEF PERIOD OF FZRA MAY OCCUR EARLY THIS MORNING. REGIONAL RADAR
MOSAIC EARLY THIS MORNING SHOWS A SLUG OF PRECIP SLIDING EAST ACROSS
NORTH CENTRAL IL/FAR WESTERN IL...HOWEVER SFC OBS INDICATE THIS IS
VERY LIGHT AND IN SOME LOCATIONS NOT REACHING THE GROUND.

CONFIDENCE IN TEMPERATURES...HIGH.

CONFIDENCE IN ACCUMULATING SNOWFALL...LOW.

CONFIDENCE IN PRECIP CHANGE TIMING...LOW.

TONIGHT THROUGH FRIDAY...

CONFIDENCE...HIGH.

THEN COOLER AIR WILL RETURN FOR THE START OF NEXT WEEK...WITH TEMPS
RETURNING TO SEASONAL CONDITIONS IN THE 30S.

CONFIDENCE...HIGH.

BEACHLER

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 16Z...

* RAIN THROUGH THE REST OF THE DAY...MIXING/CHANGING TO SNOW
EARLY TO MID EVENING.

* GRADUALY BACKING OF GENERALLY 7 TO 9 KT WINDS FROM SE TO NE
TODAY AND TO N AND NW TONIGHT. WINDS TO INCREASE SOMEWHAT
TONIGHT...AVERAGING 9 TO 12 KT BY LATE EVENING.

* VFR CIGS WITH AREAS OF MVFR LOWERING IFR BY EARLY
AFTERNOON...WITH POSSIBLR LIFR CIGS LATER AFTERNOON INTO THE
NIGHT.

* REDUCED VISIBILITY...GENERALLY 2 TO 4SM REST OF DAY AND THROUGH
MUCH/ALL OF THE EVENING.

KREIN

//DISCUSSION...UPDATED 15Z...

TRS

//PREVIOUS DISCUSSION...UPDATED 12Z...

KREIN

//ORD AND MDW CONFIDENCE...UPDATED 16Z...

* HIGH CONFIDENCE IN PRECIP OCCURRENCE AND TYPE THROUGH
AFTERNOON.

* HIGH CONFIDENCE IN WIND TRENDS REST OF DAY AND THIS EVENING.

* MEDIUM CONFIDENCE IN TIMING OF CHANGE/MIX OF RAIN AND DURING
FIRST PART OF EVENING...THEN TO ALL SNOW OVERNIGHT.

* MEDIUM CONFIDENCE IS VIS TRENDS.

* LOW CONFIDENCE IN TIMING OR EXTENT OF LIFR CIGS.

TRS

//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 16Z...

FRIDAY NIGHT...VFR. WX NIL.

SATURDAY...VFR. WX NIL.

SUNDAY...RAIN LIKELY. IFR CONDITIONS POSSIBLE.

MONDAY...CHANCE OF RAIN AND MVFR CIGS EARLY...THEN VFR.

TUESDAY...VFR. WX NIL.

WEDNESDAY...VFR. WX NIL.

KREIN

.MARINE...
320 AM CST

A RIDGE OF HIGH PRESSURE EXTENDS FROM WESTERN ONTARIO TO THE
NORTHERN PLAINS WHILE TWO LOW PRESSURE SYSTEMS DEVELOP...ONE OVER
IOWA AND ANOTHER OVER THE SOUTH HIGH PLAINS. AS THE 2 LOWS
CONSOLIDATE INTO A SINGLE LOW OVER INDIANA TONIGHT...THE HIGH WILL
BUILD INTO THE UPPER MISSISSIPPI VALLEY...LEADING TO A
STRENGTHENING NORTHERLY GRADIENT OVER THE LAKE...WITH WINDS UP TO
AROUND 30 KT DEVELOPING. ON FRIDAY THE INDIANA LOW WILL MERGE WITH
A RAPIDLY DEEPENING LOW OF THE MID ATLANTIC COAST WHILE THE HIGH
PRESSURE SPREADS OVER THE LAKE. THIS WILL LEAD TO RAPIDLY
DIMINISHING WINDS OVER THE LAKE FOR FRIDAY NIGHT AND SATURDAY.

KREIN

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ005-ILZ006 UNTIL MIDNIGHT FRIDAY.

WINTER WEATHER ADVISORY...ILZ003-ILZ004 UNTIL 9 PM THURSDAY.

WINTER WEATHER ADVISORY...ILZ008-ILZ011-ILZ012-ILZ013-ILZ014
UNTIL 9 PM THURSDAY.

IN...NONE.
LM...NONE.
&&

AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

1120 AM CST THU FEB 7 2013

.DISCUSSION...
1117 AM CST

HAVE EXPANDED WINTER WEATHER ADVISORY TO INCLUDE WINNEBAGO AND BOONE
COUNTIES AND THE I-88 CORRIDOR.

RC/KJB

.PREV DISCUSSION...
553 AM CST

BEACHLER

//PREV DISCUSSION...
337 AM CST

VERY DYNAMIC AND CHALLENGING WEATHER SYSTEM CONTINUES TO SLIDE EAST
FROM THE CENTRAL PLAINS TODAY. SFC TEMPS HAVE REMAINED MILD
OVERNIGHT IN THE LOW/MID 30S...WITH DEW POINTS HOVERING AROUND 30
DEG IN MANY LOCATIONS. IR IMAGERY INDICATES CONSIDERABLE CLOUD
COVER...WITH THE COLDEST CLOUDS ORIENTED FROM CENTRAL IOWA NORTHEAST
THROUGH CENTRAL WISCONSIN INTO NORTHERN LOWER MICHIGAN. EARLY THIS
MORNING CONSIDERABLE LIGHTING WAS NOTED ACROSS KANSAS AND CENTRAL
MISSOURI...INDICATING THAT CONSIDERABLE LIFT/UPGLIDE WAS OCCURRING
IN THIS AREA. IN ADDITION TO THE THUNDERSTORM ACTIVITY UPSTREAM OF
NORTHERN IL/NORTHWEST IN...WAS TEMPS IN THE LOW/MID 40S ACROSS
SOUTH CENTRAL IOWA EARLY THIS MORNING. WARM/MOIST AIR CONTINUES TO BE
TRANSPORTED NORTH FROM THE WESTERN GULF OF MEXICO AHEAD OF THE
SHORTWAVE...WHICH WILL PLAY A LARGE ROLE IN KEEPING THE BULK OF THE
PRECIP AT THE ONSET AS LIQUID. HOWEVER...A FEW SITES CONTINUE TO
SHOW TEMPS AROUND THE FREEZING MARK. THUS IT IS CONCEIVABLE THAT A
BRIEF PERIOD OF FZRA MAY OCCUR EARLY THIS MORNING. REGIONAL RADAR
MOSAIC EARLY THIS MORNING SHOWS A SLUG OF PRECIP SLIDING EAST ACROSS
NORTH CENTRAL IL/FAR WESTERN IL...HOWEVER SFC OBS INDICATE THIS IS
VERY LIGHT AND IN SOME LOCATIONS NOT REACHING THE GROUND.

CONFIDENCE IN TEMPERATURES...HIGH.

CONFIDENCE IN ACCUMULATING SNOWFALL...LOW.

CONFIDENCE IN PRECIP CHANGE TIMING...LOW.

TONIGHT THROUGH FRIDAY...

CONFIDENCE...HIGH.

THEN COOLER AIR WILL RETURN FOR THE START OF NEXT WEEK...WITH TEMPS
RETURNING TO SEASONAL CONDITIONS IN THE 30S.

CONFIDENCE...HIGH.

BEACHLER

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 16Z...

* RAIN THROUGH THE REST OF THE DAY...MIXING/CHANGING TO SNOW
EARLY TO MID EVENING.

* GRADUALY BACKING OF GENERALLY 7 TO 9 KT WINDS FROM SE TO NE
TODAY AND TO N AND NW TONIGHT. WINDS TO INCREASE SOMEWHAT
TONIGHT...AVERAGING 9 TO 12 KT BY LATE EVENING.

* VFR CIGS WITH AREAS OF MVFR LOWERING IFR BY EARLY
AFTERNOON...WITH POSSIBLR LIFR CIGS LATER AFTERNOON INTO THE
NIGHT.

* REDUCED VISIBILITY...GENERALLY 2 TO 4SM REST OF DAY AND THROUGH
MUCH/ALL OF THE EVENING.

KREIN

//DISCUSSION...UPDATED 15Z...

TRS

//PREVIOUS DISCUSSION...UPDATED 12Z...

KREIN

//ORD AND MDW CONFIDENCE...UPDATED 16Z...

* HIGH CONFIDENCE IN PRECIP OCCURRENCE AND TYPE THROUGH
AFTERNOON.

* HIGH CONFIDENCE IN WIND TRENDS REST OF DAY AND THIS EVENING.

* MEDIUM CONFIDENCE IN TIMING OF CHANGE/MIX OF RAIN AND DURING
FIRST PART OF EVENING...THEN TO ALL SNOW OVERNIGHT.

* MEDIUM CONFIDENCE IS VIS TRENDS.

* LOW CONFIDENCE IN TIMING OR EXTENT OF LIFR CIGS.

TRS

//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 16Z...

FRIDAY NIGHT...VFR. WX NIL.

SATURDAY...VFR. WX NIL.

SUNDAY...RAIN LIKELY. IFR CONDITIONS POSSIBLE.

MONDAY...CHANCE OF RAIN AND MVFR CIGS EARLY...THEN VFR.

TUESDAY...VFR. WX NIL.

WEDNESDAY...VFR. WX NIL.

KREIN

.MARINE...
320 AM CST

KREIN

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006 UNTIL 9 PM
THURSDAY.

WINTER WEATHER ADVISORY...ILZ008-ILZ011-ILZ012-ILZ013-ILZ014
UNTIL 9 PM THURSDAY.

IN...NONE.
LM...NONE.
&&

AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

546 PM CST FRI FEB 8 2013

.AVIATION...
MVFR CONDITIONS EXPECTED TO CONTINUE THROUGH AT LEAST 09/10Z.
MOISTURE TRAPPED UNDER AN INVERSION WILL REMAIN THERE AS A
SURFACE HIGH MOVES INTO THE GREAT LAKES TONIGHT. SOUTHERLY WINDS
ON THE BACK SIDE OF THE HIGH SHOULD RESULT IN CLEARING DEVELOPING
ACROSS KS/MO THAT BEGINS MOVING NORTH INTO IA/IL AFT 06Z/09. CONDITIONS
SHOULD IMPROVE TO VFR AFT 12Z/09. LIGHT AND VARIABLE WINDS TONIGHT
TO SLOWLY INCREASE OUT OF THE SOUTHEAST AT 10-15KT AFTER 09/15Z.
..LE..

.PREV DISCUSSION... /ISSUED 252 PM CST FRI FEB 8 2013/

SYNOPSIS...
12Z UA ANALYSIS HAS TWO SEPARATE 850MB LOWS STARTING TO MERGE OVER
THE MID ATLANTIC AREA WITH HIGH PRESSURE ACROSS THE PLAINS.
SATELLITE TRENDS THROUGH MID AFTERNOON SHOW CLEARING OF THE LOW
CLOUDS ACROSS MN/WI MOVING INTO PARTS OF ILLINOIS IN A SUBSIDENCE
AREA. CLEARING OF THE LOW CLOUDS WAS ALSO OCCURRING ACROSS THE
SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY WHILE CLOUDS REMAIN
ACROSS THE MID MISSISSIPPI VALLEY.

18Z SFC ANALYSIS HAS A LOW IN SOUTHWEST SOUTH DAKOTA WITH A WARM
FRONT INTO NORTHEAST NEBRASKA. HIGH PRESSURE EXTENDED FROM WESTERN
LAKE SUPERIOR INTO TEXAS. DEW POINTS WERE IN THE TEENS AND 20S
ACROSS THE GREAT LAKES AND PLAINS WITH 30S AND HIGHER OVER THE OHIO
VALLEY AND DEEP SOUTH.

SHORT TERM...TONIGHT AND SATURDAY...
QUIET AND DRY CONDITIONS WILL BE SEEN ACROSS THE AREA TONIGHT AND
SATURDAY AS HIGH PRESSURE MOVES INTO THE EASTERN GREAT LAKES.

CLOUDS WILL HOLD ACROSS THE AREA FOR MUCH OF TONIGHT UNTIL RETURN
FLOW DEVELOPS AND ALLOWS THE SUBSIDENCE ACROSS KS/MO TO MOVE
NORTHWARD. CLOUDS ARE EXPECTED TO CLEAR FROM SOUTH TO NORTH FROM
JUST PRIOR TO DAWN THROUGH SATURDAY MORNING ACROSS THE AREA.

THERE ARE QUESTIONS AS TO WHETHER OR NOT THERE COULD BE ANY FOG
DEVELOPMENT TONIGHT. IF IT WOULD OCCUR...IT SHOULD BE VERY PATCHY
IN NATURE. THE RAP INITIALLY INDICATED SIGNIFICANT FOG
DEVELOPMENT TONIGHT BUT MORE RECENT TRENDS HAVE BACKED OFF ON ANY FOG
DEVELOPMENT.

AREAS THAT ARE CLEAR THIS EVENING AND OVER THE SNOW FIELD SHOULD SEE
TEMPERATURES IN THE TEENS AND POSSIBLY SOME SINGLE DIGITS.
ELSEWHERE...TEMPERATURES ARE EXPECTED TO REMAIN IN THE LOW TO MID
20S. ABOVE NORMAL TEMPERATURES ARE EXPECTED ON SATURDAY. ..08..

LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
DEEP SOUTHERLY FLOW WILL ALREADY BE IN PLACE SATURDAY EVENING...AND
WITH MOISTURE RAPIDLY SURGING NORTH THROUGH THE EVENING AND
OVERNIGHT...CLOUDS WILL BECOME WIDESPREAD AND OPAQUE EARLY ON...IF
NOT ALREADY AT SUNSET IN MOST PLACES. WINDS WILL ALSO BE ON THE
INCREASE THROUGH THE NIGHT....ALLOWING FOR TEMPERATURES TO REMAIN
ABOVE FREEZING...EVEN AFTER A POSSIBLE EVENING DIP TO LOWS EARLY IN
THE EVENING. THUS...DESPITE MODEL GUIDANCE SUGGESTING FREEZING RAIN
OVERNIGHT...IT REALLY SEEMS UNLIKELY GIVEN OUR SNOW PACK ONLY OVER
OUR FAR NORTH...AND THE INCREASING WAA AFTER AN ALREADY MILD DAY
PRECEDING IT. FOR NOW...WILL ONLY MENTION THIS POTENTIAL IN THE FAR
NORTH...OVER THE CURRENT SNOW AREA...BUT EVEN THERE THE THREAT FOR
NEW ICE FORMATION FROM FREEZING RAIN SEEMS QUITE LOW.

OTHERWISE...WAA OVERNIGHT SHOULD PRODUCE WIDESPREAD RAIN AFTER
MIDNIGHT AS THE COLUMN SATURATES...WITH A BAND OF MODERATE RAIN WITH
EMBEDDED THUNDER WORKING OVER THE AREA FROM SOUTH TO NORTH SUNDAY
THROUGH EARLY AFTERNOON. RAINFALL OF 0.25 TO 0.50 IS LIKELY WITH
SOME HIGHER POSSIBLE IN CONVECTION AND ANY TRAINING BANDED HEAVY
RAINS. AFTER 3 PM...A DRY SLOT SHOULD AFFECT MOST LOCATIONS...WITH
BREEZY/WINDY SOUTHWEST TO WEST WINDS WRAPPING IN. SOME SHOWERS MAY
YET OCCUR IN THE NORTH HALF AS WRAP AROUND MOISTURE MOVES BACK IN
DURING THE EVENING. SNOW SHOWERS ARE POSSIBLE LATE AND ON MONDAY
MORNING.

THERE SEEMS VERY LITTLE THREAT FOR ACCUMULATING SNOW WITH THIS
STORM...AS MODELS NOW HAVE TEMPERATURES ABOVE FREEZING MONDAY IN THE
DEEP MIXED OCCLUDED CYCLONE CIRCULATION. THE MILD AIR SHOULD CONTINUE
THROUGH MID WEEK BEFORE A SIGNIFICANT CLIPPER OR WESTERLY SHORT WAVE
MAY BRING ANOTHER SHOT AT RAIN OR SNOW TOWARD THURSDAY AND FRIDAY.
THE MODELS ARE IN POOR AGREEMENT ON THIS WAVE BEYOND THAT IT EXISTS.
THE GFS SHOWS A PERSISTENT SNOW...WHILE THE ECMWF SHOWS A GLANCING
SHOT OF RAIN AND SNOW GOING MAINLY NORTH.

ERVIN

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

AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

304 PM CST THU FEB 7 2013

.SYNOPSIS...
12Z UA ANALYSIS HAS A WEAK 850MB LOW IN NORTHWEST MISSOURI WITH
ANOTHER IN THE OKLAHOMA PANHANDLE. A MOISTURE PLUME RAN FROM THE
GULF UP INTO THE MID MISSISSIPPI VALLEY WITH A STRONGER MOISTURE
PLUME OVER THE SOUTHEAST CONUS. RADAR TRENDS THROUGH MID AFTERNOON
CONTINUE TO SHOW WIDESPREAD RAIN ACROSS THE AREA WITH A MIX AND
CHANGE OVER TO SNOW ROUGHLY ALONG THE WI/IL BORDER.

18Z SFC ANALYSIS HAS A WEAK LOW WEST OF KMUT WITH A WARM FRONT
RUNNING ROUGHLY EAST ALONG I-80. THE COLD FRONT RAN SOUTH INTO
NORTHEAST OKLAHOMA. SEVERAL INVERTED TROFS RAN FROM THE LOW INTO
WISCONSIN AND SOUTHEAST MINNESOTA. DEW POINTS WERE IN THE 40S AND
50S ACROSS THE LOWER MISSISSIPPI VALLEY WITH 20S AND 30S OVER THE
GREAT LAKES AND MID MISSISSIPPI VALLEY.

.SHORT TERM...TONIGHT AND FRIDAY...
DYNAMIC COOLING OF THE ATMOSPHERIC COLUMN HAS ALLOWED A MIX AND
CHANGE OVER TO SNOW ALONG THE HWY 20 CORRIDOR EAST OF KDBQ. CAA IS
NOW OCCURRING ACROSS THE FAR WESTERN PART OF THE CWFA BUT NO DYNAMIC
COOLING OF THE ATMOSPHERE HAS OCCURRED YET.

PER THE RAP TRENDS...DYNAMIC COOLING OF THE ATMOSPHERE WILL CONTINUE
TO SLOWLY PUSH THE MIX AND CHANGE OVER TO THE SOUTH LATE THIS
AFTERNOON AND EARLY EVENING FROM ROUGHLY THE MISSISSIPPI ON EAST AND
NORTH OF I-80. MINOR ACCUMULATIONS ARE POSSIBLE ON GRASSY SURFACES
WITH THE HIGHEST AMOUNTS OF 1-1.5 INCHES ALONG THE HWY 20 CORRIDOR
EAST OF KDBQ.

ACROSS THE REMAINDER OF THE CWFA IT WILL BE A RACE BETWEEN THE RAIN
ENDING AND THE COLD AIR ARRIVING. TRENDS WITH THE RAP SUGGEST A MIX
DEVELOPING JUST PRIOR TO THE RAIN ENDING OVER THE WESTERN HALF WITH
THE SOUTHERN MOST EXTENT ABOUT I-80.

THUS THE OVERALL SCENARIO IS ONE OF PRECIPITATION ENDING FROM WEST
TO EAST LATE THIS AFTERNOON THROUGH MIDNIGHT. BY MID EVENING AREAS
GENERALLY WEST OF A KDBQ TO KMQB LINE SHOULD BE DRY DUE TO DOWNWARD
MOTION AND INCREASING CONDENSATION PRESSURE DEFICITS.

AFTER MIDNIGHT...DRY CONDITIONS ARE EXPECTED. THE LARGE EXTENT OF
LOW CLOUDS UP INTO THE NORTHERN PLAINS INDICATES THAT CLEARING WILL
BE SLOW TO OCCUR. BREAKS IN THE CLOUD COVER SHOULD DEVELOP LATE
TONIGHT WITH CLEARING OCCURRING IN ERNEST STARTING AROUND SUNRISE.

QUIET AND DRY CONDITIONS WILL BE SEEN ON FRIDAY AS HIGH PRESSURE
BUILDS INTO THE AREA. SKIES WILL CONTINUE TO CLEAR DURING THE DAY
WITH MOSTLY SUNNY CONDITIONS EXPECTED BY MID AFTERNOON. ..08..

.LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY...
OUR ATTENTION THIS LONG TERM FORECAST CONTINUES TO BE THE LARGE
SYNOPTIC STORM SET FOR THE WEEKEND INTO EARLY NEXT WEEK. GLOBAL AND
CONUS MODELS ARE IN GREAT AGREEMENT ON GENERAL DETAILS SHOWING A
DEEP/CLOSED UPPER TROF EXITING THE ROCKIES SATURDAY...SWEEPING
NORTHEAST SUNDAY...WHILE A STRONG SURFACE LOW MOVES FROM THE WESTERN
PLAINS TO SOUTHERN MN BY SUNDAY NIGHT. THIS PATH WILL BRING STRONG
SOUTH WINDS...AND MILD AIR TO THE REGION SATURDAY THROUGH
SUNDAY...ALONG WITH A PERIOD OF HIGH PROBABILITY RAIN SHOWERS AND
POSSIBLE THUNDER. RAINFALL TOTALS OF 0.25 TO 0.75 ARE CERTAINLY
POSSIBLE GIVEN THE STRONG FORCING...BUT ARE NOT LIKELY TO GET MUCH
HIGHER GIVEN THE PRONOUNCED DRY SLOT FORECAST TO SWEEP THROUGH THE
CWA SUNDAY AFTERNOON. BEHIND THIS SYSTEM...ALL MODELS SHOW WRAP
AROUND OCCLUDED LIGHT SNOW OR SNOW SHOWERS EITHER IN OUR NORTH
HALF...OR JUST NORTH OF THE CWA BORDER. THUS...SOME LOW POPS ARE IN
THE FORECAST FOR SUNDAY NIGHT AND MONDAY NORTH...AND DEPENDING ON
HOW THIS ALL UNFOLDS...THEY MAY NEED TO BE EXPANDED.

TEMPERATURES ARE ON THE MILD SIDE OF A GUIDANCE BLEND THROUGH THE
FORECAST GIVEN OUR HIGHLY CHANGEABLE SNOW COVER SITUATION TODAY. AT
THIS TIME...IT DOES APPEAR MOST IF NOT ALL SNOW SHOULD BE GONE BY
SUNDAY NIGHT. THUS...THE COLD INTRUSION BEHIND THIS LARGE SYSTEM MAY
LACK MUCH POTENCY.

ERVIN

.AVIATION...
COOLING OF THE ATMOSPHERE WILL ALLOW THE RAIN TO CHANGE TO SNOW AT
KDBQ WITH A POSSIBLE MIX DEVELOPING AT KCID/KMLI. VLIFR/LIFR
CONDITIONS WILL CONTINUE THROUGH 00Z/08 WITH SLOW IMPROVEMENT TO
IFR/MVFR THROUGH 12Z/08. AFT 12Z/08 CONDITIONS WILL IMPROVE TO VFR
AS HIGH PRESSURE BUILDS INTO THE MIDWEST. ..08..

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

AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

1237 PM CST THU FEB 7 2013

.UPDATE...
BASED ON SFC OBS AND MORE RECENT RAP TRENDS...MIXED PRECIPITATION
SHOULD BEGIN IN THE HWY 20 CORRIDOR FROM KDBQ EAST AROUND MID
AFTERNOON. WBZ TEMPERATURES ARE STILL ABOVE FREEZING AT THE SFC
BUT AS CAA DEVELOPS WITH THE PASSAGE OF THE LOW...DYNAMIC COOLING
OF THE OVERALL ATMOSPHERIC COLUMN WILL OCCUR. SINCE SFC
TEMPERATURES WILL REMAIN ABOVE FREEZING THERE MAY BE A MINOR SLUSHY
ACCUMULATION POSSIBLE.

ACROSS THE WESTERN CWFA...CAA DURING THE AFTERNOON SHOULD ALSO
ALLOW A RA/SN MIX AS COOLING OF THE ATMOSPHERIC OCCURS. WBZ
TEMPERATURES ARE PROJECTED TO REMAIN ABOVE FREEZING AS WELL BUT
SOME VERY MINOR ACCUMULATIONS MAY OCCUR ON GRASSY SURFACES. ..08..

.PREV DISCUSSION... /ISSUED 1056 AM CST THU FEB 7 2013/

UPDATE...
THE PRECIPITATION APPEARS TO CONFORM REASONABLY WELL WITH THE
290K THETA SFC. BASED ON RAP TRENDS RAIN WILL CONTINUE THROUGH
THE AFTERNOON. FCST SOUNDINGS FROM THE RAP SHOW CAA OCCURRING FROM
WEST TO EAST DURING THE AFTERNOON WHICH SHOULD RESULT IN A MIX
DEVELOPING ACROSS THE FAR WEST BY MID AFTERNOON THAT SLOWLY MOVES
EAST.

AS THE BETTER FORCING MOVES EAST DURING THE AFTERNOON HOURS THE
PRECIPITATION WILL BECOME LESS INTENSE AND SLOWLY END FROM WEST TO
EAST AS WELL. HOWEVER...IT NOW APPEARS THAT PRECIPITATION WILL
LINGER INTO THE EVENING HOURS...ESPECIALLY EAST OF THE
MISSISSIPPI. FCST SOUNDINGS CONTINUE TO COOL BUT THE PRECIPITATION
WILL BE NEARLY OVER BY THE TIME THE COLD AIR ARRIVES.

SNOW AMOUNTS WILL BE VERY MINIMAL WITH AMOUNTS BEING A DUSTING AT
BEST. ..08..

AVIATION...
FOR THE 18Z TAFS...IFR TO LIFR CONDITIONS WILL CONTINUE THROUGH
THROUGH 00Z/08 BEFORE IMPROVING TO MVFR AS LOW PRESSURE MOVES INTO
THE GREAT LAKES FROM MISSOURI. THE MODELS INDICATE SKIES SHOULD
CLEAR BY SUNRISE FRIDAY RESULTING IN VFR CONDITIONS. ..08..

PREV DISCUSSION... /ISSUED 400 AM CST THU FEB 7 2013/

SYNOPSIS...
THE 2 AM SURFACE AND RADAR ANALYSIS DEPICTS AREA OF DEVELOPING RAIN
WITH SOME EMBEDDED THUNDER TO OVERSPREAD THE FORECAST AREA THE NEXT
6-9 HOURS BEFORE MOVING NORTHEAST. SURFACE TEMPERATURES MILDER AND
WETTER THAN MOST/ALL SOLUTIONS SUPPORTING MODERATE RAIN TOTALS WITH
TEMPERATURES ABOVE FREEZING. NOWCAST TOOLS SUPPORT AREA OF HEAVIEST
RAIN TO FALL ROUGHLY ALONG THE CONCEPTUAL TRIPLE POINT WHICH SHOULD BE
+/- 25 NM EITHER SIDE OF A OTM TO SQI AXIS. UPSTREAM ANALYSIS SUPPORTS
NEXT SYSTEM TO AFFECT AREA LATE IN THE WEEKEND TO BE RAIN OR MOSTLY RAIN
EVENT WITH LIGHT TO MODERATE RAIN TOTALS.

SHORT TERM...TODAY AND TONIGHT...
TODAY...THE "LIFT" TOOL SUPPORTS ISOLATED EMBEDDED THUNDER ALONG WAA
WING AXIS AHEAD OF VORT MAX OVER SOUTHEAST 1/2 TO 2/3 AREA. HAVE
CATEGORICAL POPS WITH WIDESPREAD EVENT RAIN TOTALS OF 1/3 TO 2/3 OF
AN INCH. WARMER TEMPERATURES TO MITIGATE FOG TO AREAS OR PATCHY
WITH VISIBILITIES MOSTLY AOA 1 MILE ATTM. THIS WILL NEED TO BE
REASSESSED AS SFC LOW CONVERGENCE WILL BE THE KEY THIS AM FOR AREAS
OF DENSE FOG. TRENDS SUGGEST SNOW OR POSSIBLY SOME SLEET ON BACKSIDE
THIS LATE PM AND EARLY EVENING HOURS WITH LITTLE OR NO ACCUMULATIONS.
HIGHS SHOULD BE 40 TO 45 SOUTH WITH MID DAY MAX TEMPS AND NORTH 35
TO 40 DEGREES WITH SLOW FALL IN PM HOURS.

TONIGHT...REDUCED POPS WITH ANY LINGERING LIGHT PRECIPITATION TO EXIT
FAR EAST SECTIONS BY 9 PM. CLOUDY SKIES WITH NW WINDS OF 10-15 KTS
AND SUBSIDENCE SHOULD CLEAR BETWEEN 03-09Z MOST LOCATIONS. MINS IN
THE LOWER 20S NW WITH NEAR 30 DEGREES FAR SE SECTIONS. LATER SHIFTS
MAY NEED TO ADJUST MINS BY A CATEGORY OR MORE IF CLEARING IS FASTER
OR SLOWER.

NICHOLS

LONG TERM...FRIDAY THROUGH WEDNESDAY...
FOCUS REMAINS ON LARGE STORM SYSTEM LIFTING OUT OF THE SOUTHWEST
SATURDAY NIGHT THROUGH SUNDAY NIGHT. THIS IS STILL LOOKING TO BE
PRIMARILY A RAIN SYSTEM FOR THE REGION.

00Z MODEL RUNS ARE IN SOMEWHAT AGREEMENT WITH THE SURFACE AND UPPER
LEVEL LOWS TRACKING WELL NORTHWEST OF THE FORECAST SUNDAY AND SUNDAY
NIGHT AND OVERALL...ONLY A FEW CHANGES MADE TO THE FORECAST.
PRECIPITATION WILL DEVELOP SATURDAY NIGHT IN A WARM ADVECTION
WING...INITIALLY IN THE WEST...SPREADING INTO THE EAST AND NORTHEAST
BY SUNRISE. THE OVERALL SETUP APPEARS SIMILAR TO THE ON-GOING
SYSTEM...THAT IS SOUTHEAST WINDS AND CLOUD COVER WILL RESULT IN A
NEAR STEADY TO TEMPERATURE TREND FROM LATE AFTERNOON THROUGH
OVERNIGHT. AFTER A WARM SATURDAY...WITH TEMPERATURES REACHING IN THE
30S NORTH AND MID 40S SOUTH...READINGS WILL LIKELY REMAIN IN THE 30S
THROUGH THE NIGHT. MODELS APPEAR TO AGAIN BE OVERDOING THE COLD AIR
AT THE SURFACE. FOR NOW...WILL INCLUDE A POSSIBLE RAIN/SNOW MIX AT
ONSET ACROSS THE NORTH AND NORTHEAST. BASED ON INCREASING CONFIDENCE
ON EVENT TIMING...HAVE RAISED POPS TO LIKELY IN THE WEST AND ADDED A
MENTION OF THUNDER IN THE FAR SOUTHWEST WHERE STRONGEST FORCING AND
SUFFICIENTLY STEEP MID LEVEL LAPSE RATES OF BOTH THETA E AND
TEMPERATURES COINCIDE.

SUNDAY...CATEGORICAL POPS COVER ALL BUT THE FAR SOUTH FOR MODERATE
RAINFALL AMOUNTS WITH ISOLATED THUNDERSTORMS. WARM ADVECTION OF A
GULF AIRMASS WILL PUSH TEMPERATURES AND DEWPOINTS WELL INTO THE 40S
AND POSSIBLY LOWER 50S SOUTH. A LARGE DRY SLOT AND TRAILING OCCLUDED
FRONT WILL PUSH THROUGH SUNDAY NIGHT...AND HAVE LOWERED POPS TO
SLIGHT CHANCES IN THE SOUTH. THERMAL PROFILES SUGGEST POSSIBLY BRIEF
CHANGE OVER TO SNOW BEFORE ENDING...BUT LITTLE IF ANY ACCUMULATIONS
ARE EXPECTED.

MONDAY THROUGH WEDNESDAY....MODEL CONSENSUS SUPPORTS AN OVERALL DRY
FORECAST WITH TEMPERATURES TRENDING BACK CLOSER TO MID FEB NORMALS.

SHEETS

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

AREA FORECAST DISCUSSION

NWS DES MOINES IA

1150 AM CST THU FEB 7 2013

...UPDATED AVIATION DISCUSSION...

.SHORT TERM /TODAY/...
MAIN FORECAST CONCERN IS WITH ONGOING RAIN AND SMALL POTENTIAL FOR
FZRA/IP/SN THIS MORNING. EXPECTING THE RAIN TO PERSIST THROUGH MUCH
OF THE MORNING BEFORE SHIFTING EAST BY AROUND 18Z OR EARLIER. LEANED
TOWARD THE NAM12 AS IT HAS THE BEST HANDLE ON CURRENT RADAR TRENDS.
THE HIRES WRF MODEL RUNS AND HRRR HAVE MUCH OF THE PRECIP CONFINED
TO THE SOUTHEAST BY 18Z AS WELL.

THE COLD FRONT...CURRENTLY LOCATED ACROSS NORTHERN IOWA JUST SOUTH
OF A MASON CITY TO SAC CITY LINE WILL CONTINUE TO SHIFT SOUTH
THROUGH THE MORNING HOURS. CAA INCREASES BY MID TO LATE MORNING AND
FRONT SHOULD CLEAR THE FORECAST AREA BY AROUND 18Z EXCEPT FOR THE
FAR SOUTHEAST. FORECAST SOUNDINGS AT MCW/ALO INDICATING SOME ICE
INTRODUCTION AT THE TOP OF THE SNOW GROWTH ZONE...BUT A DEEP DRY
LAYER B/T 600-900MB ENTRAIN INTO THIS AREA WITH THE CAA. STILL HAVE
SOME SATURATION NEAR THE SURFACE AND MIGHT BE DEEP ENOUGH FOR FZDZ.
HAVE INCLUDED MENTION OF FZDZ THROUGH THE MORNING. OTHERWISE ANY
PRECIP FALLING ALOFT LOOKS TO HAVE A TOUGH TIME REACHING THE GROUND
WITH THAT LARGE DRY LAYER. SEEMS TO BE MATCHING WELL WITH CURRENT
TRENDS AS NOT SEEING ANY PRECIP NEAR MCW/ALO ATTM. SO HAVE LOW
CONFIDENCE WITH ANY MIXED PRECIP THIS MORNING...SO LOWERED POPS THIS
MORNING AND WENT DRY BY THIS AFTERNOON OVER THE NORTHEAST. FURTHER
SOUTH...EXPECTING PRECIP TO REMAIN ALL RAIN AS TIMING OF COLD AIR IS
DELAYED UNTIL AFTER RAIN HAS DISSIPATED. NO MAJOR CHANGES TO
TEMPERATURE TREND WITH THE COLD FRONT MOVING THROUGH...SO KEPT
MENTION OF THE NON-DIURNAL TREND.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
WEEKEND SYSTEM WILL BE THE ONLY SIGNIFICANT CONCERN THIS PERIOD.
SENSIBLE WEATHER WITH CURRENT SYSTEM SHOULD HAVE DEPARTED IA BY 00Z
LEADING TO FAIR WEATHER AND EVENTUALLY MODERATING TEMPERATURES TO
END THE WEEK AS HIGH PRESSURE CROSSES THE UPPER MS VALLEY INTO THE
GREAT LAKES. THE WEATHER CHANGES QUICKLY BY SAT NIGHT HOWEVER AND
MODELS CONTINUE TO SHOW GOOD AGREEMENT WITH EVOLUTION OF THIS SYSTEM
LEADING TO RELATIVELY HIGH CONFIDENCE. ECMWF/GFS BOTH DEPICT SHARP
INCREASE IN FORCING 3KM AND BELOW INCLUDING IMPRESSIVE WARM AIR AND
THETA-E ADVECTION. THIS SURGE WILL ALSO LEAD TO LOWER STATIC
STABILITIES AS SUGGESTED BY TOKEN ELEVATED CAPES AND INCREASING K
INDICES. THIS HAS LEAD TO A MENTION OF ISOLATED THUNDER SOUTH LATE
SAT NIGHT AND EARLY SUN...SIMILAR TO WHAT IS PRESENTLY OCCURRING
SOUTH THIS MORNING. MUCH LIKE WHAT WAS SHOWN YESTERDAY...1-3KM
SURGE OF FORCING IS CLOSELY FOLLOWED BY DIVERGENCE AHEAD OF UPPER
LEVEL LOW AND DIFFERENTIAL PVA ON THE NOSE OF THE DRY SLOT. THIS
HAS LEAD TO CATEGORICAL POPS OVERNIGHT INTO SUN MORNING WHICH IS
ALSO SUPPORTED BY GEFS AND SREF PRECIP PROBS. SIGNIFICANT PRECIP
SHOULD THEN END BY SUN NIGHT WITH LINGERING WRAP AROUND MOISTURE BUT
LITTLE IN THE WAY OF FORCING.

EVEN THOUGH THERE IS RELATIVELY HIGHER CONFIDENCE IN SYSTEM TRACK
AND PRECIPITATION EVOLUTION...WARM LAYER TEMPS WILL STILL BE
HOVERING AROUND CRITICAL 1-3C VALUES NORTH KEEPING PRECIP TYPE IN
QUESTION THERE. EVOLUTION OF RAW MODEL SURFACE TEMPS...AND
DEPICTION OF ECMWF/GFS/GEM WARM LAYERS ALOFT...SUGGEST A WINTRY
MIXED BAG OF PRECIP NE QUARTER-THIRD SAT NIGHT INTO EARLY SUN
SWITCHING TO RAIN FORECAST AREA WIDE BY LATE MORNING. EXPECT SOME
SORT OF TRAVEL PROBLEMS EARLY SUN WHICH WILL BE HIGHLIGHTED IN THE
HWO...BUT DETAILS DIFFICULT AT THIS POINT. FOR INSTANCE MCW
SOUNDINGS AT 12Z SUN...NEAR THE PEAK UVM...RANGE FROM GEM/SREF ALL
SNOW...TO ECMWF RAIN/SNOW MIX...TO NAM/GFS AT OR NEARLY ALL LIQUID
WITH A 3-4C WARM LAYER AND ALL WITH SURFACE TEMPS PLUS/MINUS 32F.

SYSTEM MAY JUST LINGER INTO MON NORTH BUT ESSENTIALLY BE DONE BY
THAT TIME. MAIN STORY FOR MON WILL LIKELY BE GUSTY WNW WINDS.
OTHER MODELS LESS BULLISH...BUT GFS SHOWS MCW GUSTS OVER 40 MPH.
THIS THEN LEADS TO FAIR WEATHER FOR THE HEART OF THE NEXT WORK WEEK
WITH LITTLE IN THE WAY OF FORCING OR MOISTURE WITH MIDWEST IN
INACTIVE NW FLOW BEHIND DEPARTING LONG WAVE TROUGH AND AHEAD OF WRN
CONUS OR ROCKIES RIDGE.

.AVIATION...07/18Z
-RA WILL CONTINUE TO AFFECT EASTERN SITES...KALO/KOTM THROUGH 00Z.
LARGE AREA OF MVFR AND IFR STRATUS WILL REMAIN IN PLACE ACROSS STATE
THROUGH MUCH OF THE PERIOD. WINDS WILL INCREASE WITH GUSTS POSSIBLE
IN THE AFTERNOON. CEILINGS MAY LIFT TO HIGH MVFR AND POSSIBLY VFR
NEAR END OF PERIOD AS A WEAK HIGH PRESSURE RIDGE PUSHES ACROSS THE
AREA. BUT CONTINUED LOW LEVEL MOISTURE WILL ALSO LEAD TO THE
POSSIBILITY OF CONTINUED MVFR AND IFR VISIBILITIES THROUGH END OF
PERIOD...BUT DO NOT HAVE ENOUGH CONFIDENCE TO INCLUDE MENTION ATTM
AND WILL HAVE TO BE MONITORED.

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

SHORT TERM...PODRAZIK
LONG TERM...SMALL
AVIATION...AWB

AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

1056 AM CST THU FEB 7 2013

.UPDATE...
THE PRECIPITATION APPEARS TO CONFORM REASONABLY WELL WITH THE
290K THETA SFC. BASED ON RAP TRENDS RAIN WILL CONTINUE THROUGH
THE AFTERNOON. FCST SOUNDINGS FROM THE RAP SHOW CAA OCCURRING FROM
WEST TO EAST DURING THE AFTERNOON WHICH SHOULD RESULT IN A MIX
DEVELOPING ACROSS THE FAR WEST BY MID AFTERNOON THAT SLOWLY MOVES
EAST.

SNOW AMOUNTS WILL BE VERY MINIMAL WITH AMOUNTS BEING A DUSTING AT
BEST. ..08..

.AVIATION...
FOR THE 18Z TAFS...IFR TO LIFR CONDITIONS WILL CONTINUE THROUGH
THROUGH 00Z/08 BEFORE IMPROVING TO MVFR AS LOW PRESSURE MOVES INTO
THE GREAT LAKES FROM MISSOURI. THE MODELS INDICATE SKIES SHOULD
CLEAR BY SUNRISE FRIDAY RESULTING IN VFR CONDITIONS. ..08..

.PREV DISCUSSION... /ISSUED 400 AM CST THU FEB 7 2013/

NICHOLS

MONDAY THROUGH WEDNESDAY....MODEL CONSENSUS SUPPORTS AN OVERALL DRY
FORECAST WITH TEMPERATURES TRENDING BACK CLOSER TO MID FEB NORMALS.

SHEETS

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

AREA FORECAST DISCUSSION

NWS DES MOINES IA

539 AM CST THU FEB 7 2013

...UPDATED AVIATION DISCUSSION...

.AVIATION...07/12Z
LIFR/IFR STRATUS DECK WILL CONTINUE TO MOVE SOUTH ACROSS THE
FORECAST AREA THIS MORNING BEHIND THE COLD FRONT. EXPECTING MCW/FOD
TO DROP TO IFR/LIFR VIS/CIGS BY AROUND 13Z THIS MORNING. THE HIRES
MODELS AND MOS GUIDANCE KEEP STRATUS THROUGH TONIGHT ACROSS THE
STATE AND SEE NO REASON FOR IT TO DISSIPATE AS LOW MOISTURE REMAINS
STEADY WITH THE CAA THROUGH TODAY AND THEN BECOMES TRAPPED UNDER
INVERSION WITH SURFACE HIGH BUILDS IN TONIGHT. HAVE IFR/LIFR
CONDITIONS THROUGH END OF THE FORECAST PERIOD.

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

SHORT TERM...PODRAZIK
LONG TERM...SMALL
AVIATION...PODRAZIK

AREA FORECAST DISCUSSION

NWS DES MOINES IA

409 AM CST THU FEB 7 2013

.AVIATION...07/06Z
PRECIPITATION BECOMING MORE WIDESPREAD ACROSS THE SOUTHERN HALF OF
THE AREA...AND SHOULD REMAIN AT KDSM AND KOTM MUCH OF THE
NIGHT...AND PUSH INTO KALO LATER TONIGHT. KMCW AND KFOD NOW EXPECTED
TO BE DRY. SFC TEMPS EXPECTED TO REMAIN NEAR FREEZING OR ABOVE AT
TAF SITES WITH PRECIP EXPECTED...SO HAVE KEPT PRECIP ALL -RA. VFR
CIGS EXPECTED TO LOWER THROUGH THE NIGHT TO MVFR...AND THEN IFR AS
THE COLD FRONT PUSHES THROUGH THE CWA. SOME LIGHT FOG ALSO POSSIBLE
IN THE VICINITY OF THE FRONT OR BEHIND THE FRONT. STRATUS TO REMAIN
ACROSS THE ENTIRE CWA FOR THURSDAY INTO THURSDAY EVENING. WINDS TO
SHIFT AROUND TO THE NORTHWEST AND PICK UP IN INTENSITY BEHIND THE
FRONT FOR THURSDAY.

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

SHORT TERM...PODRAZIK
LONG TERM...SMALL
AVIATION...BEERENDS

AREA FORECAST DISCUSSION

NWS TOPEKA KS

550 PM CST FRI FEB 8 2013

...UPDATE TO AVIATION...

.DISCUSSION...

THIS AFTERNOON AN UPPER LEVEL TROUGH WAS LOCATED ACROSS SOUTHERN NV
AND SOUTHEAST CA. SCATTERED TO BROKEN CIRRUS WAS MOVING NORTHEAST
ACROSS WESTERN AND CENTRAL KS...WELL AHEAD OF THE UPPER LEVEL
TROUGH. THE LOW CLOUDS AND FOG CONTINUE TO ERODE FROM EAST TO WEST
ACROSS NORTH CENTRAL KS. THE WESTERN COUNTIES CONTINUED TO REPORT
LOW STRATUS...BUT THROUGH THE LATE AFTERNOON HOURS THE STRATUS
SHOULD MIX OUT.

TONIGHT...SCT TO BKN CIRRUS WILL CONTINUE TO MOVE NORTHEAST ACROSS
THE CWA. THIS SHOULD PREVENT THE STRATUS AND FOG FROM REDEVELOPING
TONIGHT...ALSO SOUTHEAST WINDS WILL INCREASE THROUGH THE NIGHT TO
THE 5 TO 15 MPH RANGE. THE RAP MODEL FORECAST SOUNDINGS SHOW LOW
STRATUS AND THE POTENTIAL FOR FOG DEVELOPING BUT GIVEN INCREASING
HIGH CLOUDS AND SFC WINDS I WILL LEAN MORE TOWARDS THE 18Z NAM
MODEL. OVERNIGHT LOWS WILL ONLY DROP OFF INTO THE LOWER TO MID 30S.

SATURDAY...THE UPPER LEVEL TROUGH ACROSS SOUTHERN NV WILL BEGIN TO
LIFT NORTHEAST INTO CENTRAL CO AND THE FOUR CORNERS REGION. A LEE
SURFACE CYCLONE WILL DEEPEN THROUGH THE DAY ACROSS EASTERN CO.
SOUTHEAST-SOUTHERLY LOW-LEVEL WINDS WILL ADVECT GULF MOISTURE
NORTHWARD ACROSS WESTERN AND CENTRAL KS. WAA AND ISENTROPIC LIFT
WILL INCREASE ACROSS THE CWA DURING THE AFTERNOON HOURS. LIGHT RAIN
SHOWERS WILL BEGIN TO DEVELOP AFTER 18Z ACROSS CENTRAL KS AND MOVE
NORTHEAST ACROSS THE WESTERN HALF OF THE CWA DURING THE MID AND LATE
AFTERNOON HOURS. THE INSTABILITY MAY INCREASE JUST ENOUGH FOR
ISOLATED ELEVATED THUNDERSTORMS TO DEVELOP ACROSS THE SOUTHWEST
COUNTIES OF THE CWA BY LATE AFTERNOON. HIGH AND MID LEVEL CLOUDS
WILL INCREASE THROUGH THE DAY. HOWEVER...THE LOW-LEVEL WAA SHOULD
HELP HIGHS TO REACH AROUND 50 DEGREES TO THE MID 50S DESPITE THE
CLOUD COVER.

GARGAN

SATURDAY NIGHT AND SUNDAY...NOT MUCH CHANGE IN THE MODELS FROM
PREVIOUS FORECAST. BEST CHANCE FOR PRECIPITATIONS ACROSS THE CWA
LOOKS TO BE SATURDAY NIGHT FROM 00Z-12Z. MODELS IN GOOD AGREEMENT
WITH TIMING AND TRACK OF THE H5 CLOSED LOW TRACKING OVER WESTERN
KANSAS AND CENTRAL NEBRASKA. MODELS INDICATING GOOD CHANCES FOR
CONVECTION FROM THE 06Z-12Z WINDOW WITH 100KT 500MB JET STREAK...ROBUST
PV ANOMALY EXTENDING DOWN TO 590 MB...DEEP OMEGA...0-6KM SHEAR OF
AROUND 60-70KTS...AND MUCAPE VALUES OF 250-350 J/KG. CWA GETS DRY
SLOTTED BY 12Z-18Z AND BRINGS AN END TO THE PRECIPITATION.
MOISTURE IS NOT VERY ROBUST WITH THIS SYSTEM...AND WITH THE FAST
MOVEMENT OF THE SYSTEM AS WELL AS THE DRY SLOTTING
FEATURE...EXPECT TO SEE AT MOST A TENTH OF AN INCH FOR MOST
LOCATIONS. HOWEVER...A FEW LOCATIONS COULD SEE LOCALLY HIGHER
AMOUNTS WITH THUNDERSTORMS. SYSTEM MOVES OUT QUICKLY SUNDAY
MORNING...BUT LEFT LINGERING CHANCES ALONG THE FAR EASTERN
COUNTIES FOR THE MORNING HOURS. ATTM...DON`T EXPECT TO SEE ANY WRAP
AROUND MOISTURE...BUT THE ECMWF IS HINTING AT POTENTIALLY SOME OF
THE NORTHERN COUNTIES SUNDAY AFTERNOON. TEMPERATURES WILL REMAIN
WARM ENOUGH FOR ALL LIQUID PRECIPITATION. COLD FRONT PUSHES
THROUGH LATE SUNDAY MORNING AND SUNDAY AFTERNOON...AND CAA OCCURS
SUNDAY AFTERNOON WITH A DROP IN 850MB TEMPS FROM 5C TO -5C. WINDS
WILL BE GUSTY SUNDAY WITH A NEARLY 10MB PRESSURE GRADIENT ACROSS
THE CWA. NAM PRESSURE GRADIENT MAGNITUDES APPROACH 50 MICROBARS/KM
ATTM...SO EXPECT WIND GUSTS OF 35-40MPH OR POSSIBLY HIGHER MAINLY
OVER THE NORTHERN COUNTIES.

SUNDAY NIGHT THROUGH WEDNESDAY...UPPER LEVEL RIDGING AND SURFACE
HIGH DOMINATE THE PATTERN ACROSS KANSAS. TEMPERATURES SHOULD BE
CLOSE TO NORMAL FOR THIS TIME OF YEAR WITH HIGHS IN THE 40`S AND
LOWS IN THE 20`S UNDER MOSTLY SUNNY SKIES.

EXTENDED...NEXT FRONT TO IMPACT THE REGION WILL BE WEDNESDAY NIGHT
AND THURSDAY MORNING AS AN UPPER LEVEL TROF MOVING OUT OF WESTERN
CANADA MOVES EAST ALONG THE NORTHERN TIER STATES. MOISTURE WITH
THIS SYSTEM LOOKS LIMITED..SO NOT EXPECTING PRECIPITATION.
HOWEVER...STRONG CAA WILL OCCUR. GFS AND ECMWF DIVERGE WITH THE
AMOUNT OF COLD AIR THAT ADVECTS INTO THE AREA...BUT IF GFS IS
CORRECT...850MB TEMPS OF -20C COULD BE REALIZED BY THURSDAY NIGHT
AND INTO FRIDAY MORNING...POTENTIALLY BRINGING SOME VERY CHILLY
TEMPERATURES FOR FRIDAY AND POTENTIALLY A CHANCE FOR SNOW AS A
SHRTWV PUSHES IN FRIDAY.

.AVIATION...

LLVL MOISTURE THIS FCST PERIOD EXPECT TO REMAIN EAST OF THE TAF
SITES THROUGH TONIGHT AS LLVL WINDS VEER TO A MORE SOUTHERLY
DIRECTION. ALSO..AS THE UPPER LOW LIFTS OUT SATURDAY...APPEARS THE
NEXT ROUND OF LIMITED CIGS WILL NOT ARRIVE UNTIL JUST BEYOND THIS
TAF FCST PERIOD. WILL MAINTAIN DRY FCST WITH ONLY FEW-SCT
STRATOCU AROUND 3500 AFT 12Z AND BKN MID AND HIGH CLOUDS THROUGH
THE PERIOD. SOUTHEAST WINDS 6-9KTS TONIGHT WILL INCREASE TO
12-15KTS AND GUSTY AFT 12Z.

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS TOPEKA KS

313 PM CST THU FEB 7 2013

.DISCUSSION...

TONIGHT THROUGH FRIDAY...

THE TAIL-END OF THE MORNING RAIN SHOWERS WERE SKIMMING ACROSS EAST
CENTRAL AND SOUTHEAST KANSAS THIS AFTERNOON. NORTH-NORTHWESTERLY
FLOW PREVAILED ACROSS THE REGION WITH THE COLD FRONT HAVING
PROGRESSED EAST OF THE CWA EARLIER TODAY.

TONIGHT INTO FRIDAY...A WEAK RIDGE WILL BUILD INTO THE CENTRAL CONUS
AHEAD OF THE NEXT SYSTEM THAT WILL PROGRESS INTO THE CENTRAL U.S.
THIS WEEKEND. SURFACE HIGH PRESSURE SITUATED OVER THE NORTHERN
PLAINS THIS AFTERNOON WILL SPILL SOUTHWARD INTO THE CENTRAL PLAINS
TONIGHT INTO FRIDAY. ONE AREA OF UNCERTAINTY IS WITH REGARDS TO THE
STRATUS DECK CURRENTLY UNDER THIS SURFACE HIGH AND WHETHER OR NOT
THE NORTHERLY FLOW WILL PUSH THIS DECK SOUTHWARD INTO EXTREME
NORTHEAST AND EASTERN KANSAS THIS EVENING. THE RAP IS THE MOST
AGGRESSIVE IN HOLDING LOW-LEVEL MOISTURE IN ACROSS NORTHEASTERN
KANSAS OVERNIGHT WHILE THE NAM/GFS/ECMWF SHOWS THE DRY AIR THAT IS
WEST OF THE CWA PREVAILING AND RESULTING IN CLEARING SKIES ACROSS
MUCH OF THE FORECAST AREA OVERNIGHT. WHETHER THIS STRATUS DECK
STRETCHES INTO THE REGION WILL ALSO IMPACT WHETHER THERE IS A
POTENTIAL FOR SOME PATCHY FOG TO DEVELOP EARLY FRIDAY MORNING DUE TO
THE LIGHT NORTHERLY WINDS AND THE PRESENCE OF SURFACE MOISTURE FROM
THE RAIN SHOWERS THIS MORNING. HAVE NOT ADDED ANY MENTION OF PATCHY
FOG IN THE FORECAST ATTM DUE TO THE UNCERTAINTY WITH THE MOVEMENT OF
THE STRATUS DECK...BUT WILL CONTINUE TO MONITOR THIS EVENING.

AS FOR TEMPERATURES...NORTHERLY FLOW WILL HELP TO DROP OVERNIGHT
LOWS INTO THE 20S. AS THE SURFACE HIGH SHIFTS EAST OF THE REGION ON
FRIDAY...WINDS WILL VEER TO THE EAST-SOUTHEAST WITH AFTERNOON HIGHS
RANGING FROM THE MID 40S OVER NORTHEAST KANSAS TO THE LOWER 50S
ACROSS CENTRAL KANSAS.

ACH

FRIDAY NIGHT THROUGH THURSDAY...

AN UPPER LEVEL TROUGH WILL DIG SOUTHEAST FROM THE PACIFIC NORTHWEST
INTO THE FOUR CORNERS AREA LATE FRIDAY NIGHT...THEN LIFT NORTHEAST
INTO THE CENTRAL AND SOUTHERN PLAINS SATURDAY NIGHT INTO SUNDAY.

SATURDAY THROUGH SATURDAY NIGHT...A LEE SURFACE LOW WILL DEVELOP
ACROSS EASTERN CO DURING THE DAY ON SATURDAY...THEN DEEPEN AHEAD OF
THE APPROACHING UPPER LEVEL TROUGH. SOUTHERLY LOW LEVEL WINDS AHEAD
OF THE LEE SURFACE LOW WILL ADVECT DEEPER GULF MOISTURE NORTHWARD
ACROSS EASTERN KS SATURDAY AFTERNOON AND EVENING. WAA/ISENTROPIC
LIFT WILL CAUSE SHOWERS TO DEVELOP ACROSS THE SOUTHERN COUNTIES OF
THE CWA THURSDAY AFTERNOON...THEN LIFT NORTHEAST ACROSS THE CWA
DURING THE EARLY EVENING HOURS. THE 12Z NAM AND ECMWF SHOW MUCAPE
INCREASING TO 300 TO 700 J/KG ACROSS THE CWA...THUS SCATTERED
ELEVATED THUNDERSTORMS WILL BE POSSIBLE ALONG WITH NUMEROUS SHOWERS
SATURDAY NIGHT INTO SUNDAY MORNING. THE SFC-6KM BULK SHEAR WILL BE
ABOUT 50 TO 60 KTS...THUS SOME OF THE STRONGER ELEVATED
THUNDERSTORMS MAY BE CAPABLE OF PRODUCING SMALL HAIL SATURDAY NIGHT.
WE MAY RECEIVE A QUARTER TO ONE HALF INCH OF RAINFALL...WITH SOME
LOCALLY HIGHER AMOUNTS SATURDAY NIGHT INTO SUNDAY MORNING.

SUNDAY...THE UPPER LEVEL TROUGH WILL LIFT NORTHEAST ACROSS NORTHWEST
KS INTO SOUTHWEST MN WHILE THE SURFACE LOW MOVES NORTHEAST ACROSS
EASTERN NE INTO NORTH CENTRAL IA. A PACIFIC COLD FRONT WILL MOVE
EAST ACROSS THE CWA DURING THE MORNING HOURS OF SUNDAY...AND WILL
BRING AN END TO THE SHOWERS AND SCATTERED THUNDERSTORMS ACROSS THE
EASTERN COUNTIES OF THE CWA. SKIES WILL CLEAR FROM SOUTHWEST TO
NORTHEAST ACROSS THE CWA...DURING THE LATE MORNING AND EARLY
AFTERNOON HOURS. THE WRAP AROUND PRECIP SHOULD REMAIN NORTH OF THE
STATE LINE...THOUGH CLOUDS AND PERHAPS SOME SPRINKLES OR FLURRIES
COULD DEVELOP ACROSS THE NORTHERN COUNTIES OF THE CWA DURING THE MID
AND LATE AFTERNOON HOURS. HIGHS ACROSS NORTH CENTRAL KS MAY BE
REACHED AROUND NOON...WITH SLOWLY FALLING TEMPERATURES INTO THE
UPPER 30S. THE REMAINDER OF THE CWA WILL WARM INTO THE UPPER 40S TO
MID 50S ACROSS EAST CENTRAL KS.

SUNDAY NIGHT THROUGH TUESDAY NIGHT...A SECOND UPPER LEVEL TROUGH
WILL DIG SOUTHWARD ACROSS THE WEST-CENTRAL CONUS INTO NM...THEN WILL
MOVE EAST ACROSS NORTH TX AND OK WHILE SHEARING OUT MONDAY NIGHT. THE
STRONGER ASCENT AND PRECIP CHANCES WILL OCCUR WELL SOUTH OF THE
CWA ACROSS SOUTHWEST KS AND OK. HIGHS WILL BE IN THE LOWER TO MID
40S. LOWS WILL BE IN THE 20S.

WEDNESDAY THROUGH THURSDAY...AN UPPER LEVEL TROUGH WILL MOVE ONSHORE
ACROSS THE PACIFIC NORTHWEST...THEN DIG SOUTHEAST ACROSS THE
NORTHERN AND CENTRAL PLAINS ON THURSDAY. AHEAD OF THE H5 TROUGH
TEMPERATURES WILL WARM INTO THE MID TO UPPER 40S. IF THE COLD FRONT
IS A BIT FASTER...THEN HIGH TEMPS ON THURSDAY WILL BE CAT OR TWO
COOLER. THE LOW-LEVELS OF THE ATMOSPHERE LOOK TOO DRY FOR ANY
MEASURABLE PRECIP. THE STRONGER ASCENT AHEAD OF THIS H5 TROUGH WILL
OCCUR ACROSS THE UPPER MIDWEST AND MID MS RIVER VALLEY...WELL
NORTHEAST OF THE CWA.

GARGAN

.AVIATION...

FOR 18Z TAFS...THE MORNING SHOWERS HAVE PASSED EAST OF THE TAF
SITES...RESULTING IN A RETURN TO VFR CONDITIONS WHICH WILL CONTINUE
THROUGH THE PERIOD. SCATTERED MID-LEVEL CLOUDS WILL STILL BE IN
PLACE THROUGH THE AFTERNOON HOURS BEFORE CLEARING OUT EARLY THIS
EVENING THROUGH FRIDAY. NORTHERLY WINDS THIS AFTERNOON COULD RESULT
IN A FEW GUSTS UPWARDS OF AROUND 20KTS BUT WILL WEAKEN TONIGHT. BY
MID FRIDAY MORNING...WINDS WILL VEER TOWARD THE EAST AS HIGH
PRESSURE DIPS SOUTHWARD INTO THE REGION.

ACH

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS TOPEKA KS

1203 PM CST THU FEB 7 2013

...UPDATE TO AVIATION...

.DISCUSSION...

MAIN AREA OF PRECIPITATION SO FAR HAS BEEN JUST UPSTREAM OF BEST
LOW-MID LEVEL MOISTURE CONVERGENCE WHERE STRONGER LOW LEVEL JET IS
BEING MAINTAINED EAST OF 850MB LOW. UPPER WAVE CONTINUES ITS
EASTWARD PROGRESS BUT HAS STILL JUST ENTERED THE PLAINS AT 08Z.
LATEST RAP AND 06Z NAM TAKE THIS AREA OF CONVERGENCE EAST THROUGH
THE POST-SUNRISE HOURS WHILE THE UPPER WAVE...CONTINUING TO SLOW
ITS PACE...HELPS SPREAD PRECIP NORTHEAST. THIS WILL KEEP PRECIP IN
PLACE SLIGHTLY LONGER...BUT A QUICK CLEARING IS ON TRACK FOR THE
AFTERNOON AS THE UPPER TROF CLEARS KANSAS. WEAKENING LAPSE RATES
AND LESS-FOCUSED LIFT SHOULD KEEP THUNDERSTORMS IN A ISOLATED
NATURE. MODEST COLD AIR ADVECTION AND GOOD MIXING SHOULD STILL
PUSH HIGHS INTO THE UPPER 40S TO LOWER 50S.

DEEP RIDING TO BE THE RULE INTO FRIDAY. HIGHS FRIDAY STILL SOMEWHAT
IN QUESTION WITH EASTERLY WINDS AND INCREASING HIGH CLOUDS BUT KEPT
TEMPS JUST ABOVE MOS VALUES GIVEN THEIR COOL BIAS THIS SEASON.

PRECIP CHANCES RAMP UP AGAIN SATURDAY INTO SATURDAY NIGHT AS THE
NEXT SYSTEM...ENTERING THE PACIFIC NORTHWEST IN RECENT
HOURS...EMERGES FROM THE ROCKIES. INCREASING SOUTH WINDS AND LARGE
SCALE FORCING BRINGS SOME CHANCE FOR SHOWERS BY SATURDAY
AFTERNOON...WITH THE WETTEST PERIOD EXPECTED SATURDAY NIGHT AS THE
LOW SURGES NORTHEAST INTO THE PLAINS. INSTABILITY DOES NOT LOOK
IMPRESSIVE...BUT ENOUGH FORCING MECHANISMS COME TOGETHER FOR SOME
THUNDER POTENTIAL AGAIN. TEMPS STAY WARM ENOUGH FOR AN ALL LIQUID
EVENT UNTIL PERHAPS SUNDAY AFTERNOON AS COLD AIR COMES IN BEHIND THE
LOW...BUT MEASURABLE AMOUNTS SEEM UNLIKELY AT BEST. SECONDARY SYSTEM
WORKING IN BEHIND WILL NEED TO BE WATCHED...BUT THE BULK OF IT
SHOULD REMAIN SOUTH. WILL INCLUDE SMALL OPPORTUNITIES FOR PRECIP
TUESDAY NIGHT IN FAR SOUTHERN AREAS.

.AVIATION...

ACH

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS TOPEKA KS

525 AM CST THU FEB 7 2013

...UPDATE TO AVIATION...

.DISCUSSION...
MAIN AREA OF PRECIPITATION SO FAR HAS BEEN JUST UPSTREAM OF BEST
LOW-MID LEVEL MOISTURE CONVERGENCE WHERE STRONGER LOW LEVEL JET IS
BEING MAINTAINED EAST OF 850MB LOW. UPPER WAVE CONTINUES ITS
EASTWARD PROGRESS BUT HAS STILL JUST ENTERED THE PLAINS AT 08Z.
LATEST RAP AND 06Z NAM TAKE THIS AREA OF CONVERGENCE EAST THROUGH
THE POST-SUNRISE HOURS WHILE THE UPPER WAVE...CONTINUING TO SLOW
ITS PACE...HELPS SPREAD PRECIP NORTHEAST. THIS WILL KEEP PRECIP IN
PLACE SLIGHTLY LONGER...BUT A QUICK CLEARING IS ON TRACK FOR THE
AFTERNOON AS THE UPPER TROF CLEARS KANSAS. WEAKENING LAPSE RATES
AND LESS-FOCUSED LIFT SHOULD KEEP THUNDERSTORMS IN A ISOLATED
NATURE. MODEST COLD AIR ADVECTION AND GOOD MIXING SHOULD STILL
PUSH HIGHS INTO THE UPPER 40S TO LOWER 50S.

DEEP RIDING TO BE THE RULE INTO FRIDAY. HIGHS FRIDAY STILL SOMEWHAT
IN QUESTION WITH EASTERLY WINDS AND INCREASING HIGH CLOUDS BUT KEPT
TEMPS JUST ABOVE MOS VALUES GIVEN THEIR COOL BIAS THIS SEASON.

.AVIATION...

A FEW MORE HOURS OF RAIN EXPECTED AT TAF SITES. FRONT HAS PASSED
MHK AND WILL MOVE THROUGH TOP/FOE AROUND BETWEEN 14/15Z. CIGS
IMPROVE AS RAIN ENDS AND WILL LIFT TO MVFR/VFR IN THE MID MORNING
HOURS BEFORE CLEARING OUT IN THE AFTERNOON. NORTHERLY WINDS REMAIN
OVERNIGHT. 67

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS TOPEKA KS

323 AM CST THU FEB 7 2013

DEEP RIDING TO BE THE RULE INTO FRIDAY. HIGHS FRIDAY STILL SOMEWHAT
IN QUESTION WITH EASTERLY WINDS AND INCREASING HIGH CLOUDS BUT KEPT
TEMPS JUST ABOVE MOS VALUES GIVEN THEIR COOL BIAS THIS SEASON.

.AVIATION...
05Z SFC OBS SHOWS THE FRONT STILL BACK ACROSS NORTHWEST KS. MODELS
SHOW THE BEST PRECIP CHANCES JUST AHEAD OF THE FRONT WITH THE LOW
LEVEL LIFT. SO THERE IS NOT MUCH CHANGE TO THE FORECAST EXCEPT TO
FOLLOW THE TREND OF THE 00Z MODELS TO BE AN HOUR OR TWO SLOWER WITH
THE CIGS/PRECIP/FROPA. CONTINUE TO THINK THERE WILL BE SOME IFR CIGS
AND POTENTIALLY VSBY IF SHOWERS ARE INTENSE ENOUGH. CONFIDENCE IS
ABOUT AVERAGE.

WOLTERS

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS WICHITA KS

1141 PM CST WED FEB 6 2013

.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
SCATTERED TO NUMEROUS SHOWERS AND EMBEDDED THUNDERSTORMS ARE
EXPECTED FOR THE REST OF THE NIGHT...TRANSITIONING FROM PARTS OF
CENTRAL AND SOUTH CENTRAL KANSAS INTO SOUTHEAST KANSAS DURING
THURSDAY MORNING. IFR/LIFR CONDITIONS WILL CONTINUE ALONG AND
JUST AHEAD OF THE APPROACHING COLD FRONT...WITH CONDITIONS
IMPROVING ACROSS CENTRAL KANSAS BY BEFORE DAWN. SHOWERS WITH
PREVAILING MVFR CONDITIONS AND AREAS OF IFR WILL PERSIST THRU
MID-MORNING ACROSS SOUTH CENTRAL AND SOUTHEAST KANSAS BEFORE
GUSTY NORTH WINDS AND DRIER AIR BEHIND THE COLD FRONT RESULT IN
VFR CONDITIONS ALL AREAS FOR THE LATTER HALF OF THE FORECAST
VALID PERIOD.

KED

.PREV DISCUSSION... /ISSUED 923 PM CST WED FEB 6 2013/

UPDATE...
CONVECTION HAS DEVELOPED ACROSS NORTHEAST KANSAS AT MID-EVENING
WITH THE LATEST NAM AND RUC DEVELOPING IT SOUTHWEST ACROSS CENTRAL
KANSAS TOWARD MIDNIGHT. THIS IS HANDLED FAIRLY WELL IN CURRENT
FORECAST WITH ONLY SLIGHT TWEAKS INTO THE OVERNIGHT HOURS. PATCHY
FOG AND DRIZZLE WILL CONTINUE AHEAD OF THE FRONT AS A PRECURSOR
TO THE CONVECTION...THOUGH DO NOT EXPECT THE RESTRICTIONS TO BE
LOW ENOUGH AND WIDESPREAD FOR A DENSE FOG HEADLINE AT THE MOMENT.
ELEVATED CAPE VALUES AROUND 500 J/KG AND MODEST SHEAR VALUES MAY
SUPPORT A FEW STRONG STORMS WITH SMALL HAIL AND HAVE MADE A SLIGHT
ADJUSTMENT TO THE RISK AREA OVERNIGHT.

KED

PREV DISCUSSION... /ISSUED 545 PM CST WED FEB 6 2013/

AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MVFR/IFR CIGS AND VSBYS ARE EXPECTED TO EXPAND ACROSS MUCH OF THE
AREA TONIGHT AS A COLD FRONT SLIDES EAST ACROSS CENTRAL KANSAS.
FOG AND PATCHY DRIZZLE THIS EVENING WILL BE REPLACED BY SCATTERED
TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS LATE IN THE NIGHT.
THIS ACTIVITY IS EXPECTED TO TRANSITION EAST WITH THE COLD FRONT
ACROSS SOUTH CENTRAL AND SOUTHEAST KANSAS EARLY THURSDAY MORNING.
GUSTY NORTH WINDS WILL BRING IN DRIER AIR DURING THE DAYLIGHT
HOURS ON THURSDAY WITH CONDITIONS IMPROVING FOR THE LATTER PORTION
OF THE FORECAST VALID PERIOD.

KED

PREV DISCUSSION... /ISSUED 338 PM CST WED FEB 6 2013/

DISCUSSION...

TONIGHT-THU:
MOISTURE WILL CONTINUE TO INCREASE AHEAD OF FRONT. GOOD CHANCE OF
PATCHY TO AREAS OF DRIZZLE/LIGHT SHOWERS AND FOG ACROSS SOUTH
CENTRAL/SOUTHEAST KS AS LOW LEVEL MOISTURE INCREASES AHEAD OF
FRONT. PRECIPITATION SHOULD BREAK OUT IN CENTRAL KS AHEAD OF FRONT
THIS EVENING...WITH CHANCES INCREASE TOWARDS MIDNIGHT. TOUGH CALL
ON BACK EDGE OF PRECIPITATION AT 1200 UTC...BUT LIKELY IN THE
VICINITY OF KHUT/KICT. PRECIPITATION WILL LINGER EAST OF TURNPIKE
THROUGH NOON AND EXTREME SOUTHEAST KS PAST 1800 UTC. TEMPERATURES
WILL BE HELD UP OVERNIGHT AT MOST LOCATIONS WITH SURFACE DEWPOINTS
CLIMBING INTO THE 50S. GUSTY NORTHWEST WINDS ANTICIPATED ON THU IN
WAKE OF FRONT WITH MOSTLY CLEAR SKIES AND GOOD MIXING.

FRI-SUN:
QUIET WEATHER ANTICIPATED ON FRI. TEMPERATURES STILL A BIT TRICKY
AND DEPENDENT ON MIXING HEIGHT WITH FAIRLY WARM AIR ALOFT AND AT
LEAST SOME COLDER AIR NEAR SURFACE. BASED ON RECENT VERIFICATION...
HAVE LEANED A BIT WARMER. BY FRIDAY NIGHT RETURN FLOW WILL BE
UNDERWAY WITH LOW LEVEL MOISTURE ON THE INCREASE. SOME WARM AIR
ADVECTION PRECIPITATION IS EXPECTED TO BREAK OUT SAT MORNING...
WITH CHANCES INCREASE SAT NIGHT/SUN AS SURFACE FRONT APPROACHES.
GFS HAS BEEN UNDERESTIMATING INSTABILITY AND GIVEN SYNOPTIC SET UP
WITH DIFFLUENT SOUTHWEST FLOW ALOFT AND NICE DRYLINE...BELIEVE
THERE IS A DECENT CHANCE OF STORMS DURING THE NIGHT. EVEN WITH
LESS THAN OPTIMAL TIMING OF THE DRYLINE...THE VERY STRONG DEEP
LAYER SHEAR MAY ALLOW SOME STORMS TO GET A BIT FRISKY.
PRECIPITATION CHANCES WILL END ABRUPTLY AS DRY SLOT WORKS ACROSS
THE AREA EARLY ON SUN. TRACK OF SURFACE LOW SHOULD KEEP WRAP
AROUND PRECIPITATION JUST NORTH OF FORECAST AREA.

MON-WED:
RELATIVELY QUIET AND SEASONAL WEATHER ANTICIPATED MON...BUT
DIFFERENCES IN ECMWF ARE EVIDENT ON TUE-WED. WHILE BOTH MORE OR
LESS SHOW SHORTWAVE ENERGY INDUCING SURFACE WAVE ON FRONT TO THE
SOUTH...GFS HAS SLOPPED PRECIPITATION A LOT FURTHER NORTH/NORTHWEST
THAN THE ECMWF. INITIALIZATION GRIDS REFLECTED THIS WITH LOW POPS
ACR SOUTHERN/SOUTHEAST KS. AT THIS TIME...BELIEVE CHANCES ARE SLIM
AND HAVE NIXED ACROSS SOUTH CENTRAL KS..BUT KEPT IN FAR SOUTHEAST
FOR CONSISTENCY. -HOWERTON

AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU

THE MAIN AVIATION FORECAST CONCERN IS THE IFR/MVFR CONDITIONS
TODAY/TONIGHT AND THUNDERSTORMS POSSIBLE TONIGHT.

LOW STRATUS HAS DEVELOPED ACROSS SOUTH CENTRAL AND NORTH TO
CENTRAL KANSAS AS THE WARM FRONT HAS STREAMED NORTHWARD AND HIGHER
DEWPOINTS ARE INTERACTING WITH THE COOLER TEMPERATURES. EXPECT
MVFR TO HIGH IFR STRATUS TO CONTINUE THROUGH THE NEXT 12-18 HOURS
AT MANY SITES. THE FRONT WILL MOVE THROUGH AND THE UPPER PATTERN
WILL HELP TO FIRE OFF THUNDERSTORMS BEGINNING OVERNIGHT. THINK THE
SITES WITH THE BEST CHANCE FOR THUNDERSTORMS WILL BE
KSLN/KHUT/KICT AND KCNU. THE RAIN WILL MOVE OUT AS THE UPPER WAVE
ROTATES EASTWARD...ENDING THINGS FROM WEST TO EAST THURSDAY
MORNING.

WINDS WILL BECOME NORTHERLY BEHIND THE FRONT AND BE BREEZY...BUT
CEILINGS WILL LIFT AS DRIER AIR MOVES IN.

BILLINGS

.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 51 54 30 57 / 80 60 0 0
HUTCHINSON 47 54 29 55 / 80 30 0 0
NEWTON 49 53 29 56 / 80 50 0 0
ELDORADO 50 53 28 56 / 80 80 0 0
WINFIELD-KWLD 51 55 29 57 / 30 80 0 0
RUSSELL 41 53 27 55 / 40 10 0 0
GREAT BEND 42 53 27 55 / 80 10 0 0
SALINA 44 54 27 57 / 80 10 0 0
MCPHERSON 46 53 28 56 / 80 20 0 0
COFFEYVILLE 48 56 30 58 / 10 80 0 0
CHANUTE 47 53 28 55 / 20 80 0 0
IOLA 47 52 28 54 / 30 80 0 0
PARSONS-KPPF 47 55 29 57 / 20 80 0 0

.ICT WATCHES/WARNINGS/ADVISORIES...NONE.
&&

AREA FORECAST DISCUSSION...CORRECTED

NWS DODGE CITY KS

1107 PM CST WED FEB 6 2013

...UPDATED SYNOPSIS SECTION...

.SYNOPSIS...
ISSUED AT 1100 PM CST WED FEB 6 2013

THE 00Z UPPER AIR ANALYSIS PORTRAYS A MID TO UPPER LEVEL TROUGH
EXTENDING DOWN THROUGH THE NORTHERN AND CENTRAL ROCKIES WITH A
WEAK RIDGE OF HIGH PRESSURE POSITIONED ACROSS THE PACIFIC
NORTHWEST. A MID TO UPPER LEVEL LOW IS LOCATED FARTHER NORTHWEST
ACROSS THE EASTERN PACIFIC OCEAN. AN AREA OF LOW PRESSURE BECOMES
PRESENT CLOSER TO THE SURFACE WITH A COLD FRONT EXTENDING FROM
IOWA THROUGH NORTHWEST KANSAS AND INTO SOUTHERN COLORADO. WINDS
ARE GENERALLY LIGHT AND VARIABLE AND ALLOWING LOW LEVEL MOISTURE TO
POOL UP AGAINST THIS FRONT. THIS IS ALLOWING LOW CLOUDS AND FOG
TO DEVELOP ACROSS PARTS OF WESTERN KANSAS. TEMPERATURES ACROSS
SOUTHWEST KANSAS CURRENTLY RANGE FROM THE LOWER 40S ACROSS WEST
CENTRAL KANSAS WITH UPPER 40S AND LOWER 50S ELSEWHERE.

.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 236 PM CST WED FEB 6 2013

TONIGHT:

SEVERAL SENSIBLE WEATHER IMPACTS EXPECTED TONIGHT INTO TOMORROW MORNING.
FIRST IS FOG. HRRR IS VERY AGGRESSIVE IN DEVELOPING LOW VISIBILITIES
AFTER 00Z TONIGHT. THE NAM AND ARW-WRF IS NOT AS AGGRESSIVE WITH FOG.
DUE TO THE WARM AIR ADVECTION PATTERN THAT IS CURRENTLY TAKING PLACE
AND THE HIGHER DEWPOINTS ADVECTING IN ACROSS THE REGION...WILL GO WITH
PATCHY FOG TONIGHT ALONG AND EAST OF HIGHWAY 283 WITH AREAS OF FOG
ALONG SOUTH CENTRAL KANSAS WHERE DEWPOINTS ARE HIGHER. THE NEXT CONCERN
IS CONVECTION. THE BEST CHANCE FOR OVERNIGHT THUNDERSTORMS IS GENERALLY
ALONG AND EAST OF HIGHWAY 183. HERE WARM AIR ADVECTION...ISENTROPIC
LIFT ALONG THE 295 KELVIN THETA SURFACE... AND INCREASING 850-650 HPA
FRONTOGENESIS SHOULD INITIATE CONVECTIVE ACTIVITY AFTER 03Z TONIGHT.
ALL THE MESOSCALE MODELS SUGGESTS THIS AS WELL AS THE GFS AND ECMWF.
SEVERE THUNDERSTORMS ARE NOT EXPECTED DUE TO WEAK THERMODYNAMICS AND
WEAK KINEMATICS. CONVECTION SHOULD BE CLEAR OF THE REGION BY DAWN.
A DENSE FOG ADVISORY COULD BE NEEDED FOR TOMORROW MORNING, BUT DO NOT
HAVE ENOUGH CONFIDENCE TO ISSUE ONE THIS EARLY.

TOMORROW:

TOMORROW MORNING WILL BE BREEZY AS THERE WILL BE A TIGHT PRESSURE GRADIENT
ACROSS THE REGION ALONG WITH 45 KT 850 HPA WINDS PARTIALLY MIXING DOWN.
NOT EXPECTING WIND ADVISORY LEVELS AT THIS TIME. OTHER THAN SOME POSSIBLE
LINGERING FOG, TOMORROW WILL BE FAIRLY QUIET WITH CLEARING SKIES. HIGHS
SHOULD BE IN THE 50S DEG F. WINDS SHOULD ABATE AS THE DAY WEARS ON.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM CST WED FEB 6 2013

MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL RIDGE OF HIGH PRESSURE
MOVING EASTWARD ACROSS THE CENTRAL PLAINS FRIDAY RESULTING IN DRY
CONDITIONS ACROSS WESTERN KANSAS THROUGH FRIDAY NIGHT. MEANWHILE,
A STRONG UPPER LEVEL TROUGH OF LOW PRESSURE IS EXPECTED TO DIG
SOUTHEAST INTO THE GREAT BASIN REGION FRIDAY, THEN TURN EASTWARD
MOVING INTO THE CENTRAL AND SOUTHERN ROCKIES SATURDAY BRINGING THE
POSSIBILITY FOR SHOWERS AND THUNDERSTORMS TO PORTIONS OF WESTERN
KANSAS AS EARLY AS SATURDAY AFTERNOON. A RETURN FLOW WILL SET UP
EARLY FRIDAY DRAWING GULF MOISTURE NORTHWARD INTO MUCH OF KANSAS
WITH H85 DEWPOINTS CLIMBING JUST ABOVE 0C. ADDITIONALLY, SURFACE
LOW PRESSURE IN EASTERN COLORADO WILL STRENGTHEN THROUGHOUT THE
DAY WITH A SHARPENING DRYLINE EXTENDING SOUTHWARD GENERALLY INTO
THE TEXAS PANHANDLE. DYNAMIC SUPPORT ALOFT WILL BECOME MORE
FAVORABLE AS WELL WITH THE GFS AND ECMWF SHOWING A STRONG H5 VORT
MAX LIFTING NORTHEAST OUT OF THE TROUGH AXIS AND ACROSS THE
WESTERN HIGH PLAINS SATURDAY NIGHT. A +100KT UPPER LEVEL JET WILL
ALSO BE STREAMING EAST-NORTHEAST ACROSS WEST TEXAS AND THE TEXAS
PANHANDLE INTO THE PLAINS OF WESTERN OKLAHOMA AND SOUTHERN KANSAS
LATE SATURDAY. AS A RESULT, SHOWERS AND THUNDERSTORMS ARE EXPECTED
TO DEVELOP ACROSS THE SOUTH PLAINS SATURDAY AFTERNOON AND EVENING,
LIFTING NORTHEASTWARD INTO CENTRAL KANSAS WITH CHANCES FOR THE
PRECIP DWINDLING TOWARD THE WEST. GFS AND ECMWF MODEL SOUNDINGS
INDICATE A REAL LACK OF INSTABILITY LIMITING SEVERE POTENTIAL.
ANY PRECIP WILL LIKELY COME TO AN END BY MID DAY SUNDAY AS THE
UPPER LEVEL TROUGH BEGINS TO LIFT NORTHEAST INTO THE UPPER
MIDWEST.

TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL FRIDAY EVEN AS SURFACE
HIGH PRESSURE MOVES FROM THE NORTHERN PLAINS SOUTHEAST INTO THE
UPPER MIDWEST. THIS WILL TURN WINDS SOUTH TO SOUTHEASTERLY ACROSS
WESTERN KANSAS THROUGHOUT MUCH OF THE DAY. HOWEVER, THIS WILL DO
LITTLE TO ERODE THE COOLER AIR MASS THAT IS PROJECTED TO SINK
SOUTH INTO WESTERN KANSAS BEHIND A PASSING COLD FRONT THURSDAY.
THE NAM, GFS, AND ECMWF SHOW H85 TEMPERATURES RANGING FROM JUST
ABOVE 0C ACROSS CENTRAL KANSAS TO JUST ABOVE 5C ALONG THE COLORADO
BORDER. LOOK FOR HIGHS WELL UP INTO THE 50S(F) FRIDAY AFTERNOON.
SIMILAR HIGHS ARE LIKELY SATURDAY AS SURFACE LOW PRESSURE
STRENGTHENS ACROSS EASTERN COLORADO KEEPING SOUTHERLY WINDS IN
PLACE ACROSS WESTERN KANSAS. A COLD FRONT PUSHING THROUGH WESTERN
KANSAS SUNDAY WILL ALLOW COLDER AIR TO SURGE SOUTHWARD INTO
WESTERN KANSAS RESULTING IN LOWER HIGH TEMPERATURES. OVERALL,
TEMPERATURES ARE LIKELY TO REMAIN BELOW NORMAL THROUGH MID WEEK AS
A SECONDARY UPPER LEVEL TROUGH DEVELOPS ACROSS THE INTERMOUNTAIN
WEST AND MOVES INTO THE WESTERN HIGH PLAINS DRAWING MORE COLDER
DOWN INTO THE REGION.

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 531 PM CST WED FEB 6 2013

THE MAJOR IMPACT TO AVIATION WILL BE DENSE FOG DEVELOPMENT LATE
THIS EVENING AND LASTING THROUGH THE OVERNIGHT. INCREASING LOW
LEVEL MOISTURE AHEAD OF A SURFACE COLD FRONT WILL PROVIDE THE
CONDITIONS FOR ADVECTION FOG ACROSS MUCH OF CENTRAL ANS SOUTHWEST
KANSAS BEGINNING AS EARLY AS 03 UTC. THE LATEST MESOSCALE MODELS
INCLUDING THE VARIOUS NAM ARW CORES AND THE RAPID REFRESH ARE ALL
STRONGLY SUGGESTING DENSE FOG DEVELOPMENT. IT IS BELIEVED THE LOCAL
GFS MOS (LAMP) IS TOO FOCUSED ON NORMAL DIURNAL TRENDS AND LIKELY
INCORRECT. A 700 MB WAVE WILL HELP SET OFF SHOWERS AND ISOLATED
THUNDERSTORM ACROSS CENTRAL KANSAS AS WELL, PROBABLY JUST EAST OF
HAYS AND DODGE CITY BETWEEN MID NIGHT AND 10Z. AT THIS TIME, TEMPO
1/4SM CONDITIONS WILL BE CARRIE UNTIL SUCH CONFIDENCE THAT
PREVAILING CONDITIONS CAN BE FORECAST.

.PRELIMINARY POINT TEMPS/POPS...
DDC 40 54 27 56 / 10 0 0 0
GCK 36 53 27 56 / 0 0 0 0
EHA 34 51 27 57 / 0 0 0 0
LBL 37 53 27 57 / 0 0 0 0
HYS 39 53 25 55 / 40 0 0 0
P28 48 55 30 56 / 80 50 0 0

.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 6 AM CST THURSDAY FOR KSZ030-031-
043>046-063>066-076>081-086>090.

SYNOPSIS...HOVORKA_42
SHORT TERM...SUGDEN
LONG TERM...JJOHNSON
AVIATION...RUSSELL

AREA FORECAST DISCUSSION

NWS DODGE CITY KS

1102 PM CST WED FEB 6 2013

...UPDATED SYNOPSIS SECTION...

.SYNOPSIS...
ISSUED AT 1100 PM CST WED FEB 6 2013

.UPDATE...
ISSUED AT 545 PM CST WED FEB 6 2013

THE LATEST HIGH RESOLUTION NAM WRF CORES AND THE RAPID REFRESH ARE
STRONGLY SUGGESTING THE RAPID ONSET OF DENSE FOG DEVELOPMENT THIS
EVENING. THE MODELS ARE PROBABLY DOING A BETTER JOB THAN THE LOCAL
GFS MOS AT THIS TIME, WHICH APPEARS TOO FOCUSED ON TYPICAL DIURNAL
TRENDS. WITH LOW 50`S DEW POINTS INCREASING THIS EVENING, AND
BACKING SURFACE WINDS CREATING WEAK UPSLOPE AHEAD OF AN ADVANCING
COLD FRONT FROM NORTHWEST KANSAS, FOG COULD START TO DEVELOP FROM
DIGHTON TO GARDEN CITY BY MID EVENING. A DENSE FOG ADVISORY WAS
HOISTED FROM GENERALLY THE HIGHWAY 83 CORRIDOR EASTWARD FROM 4 TO 12
UTC THURSDAY.

.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 236 PM CST WED FEB 6 2013

TONIGHT:

TOMORROW:

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM CST WED FEB 6 2013

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 531 PM CST WED FEB 6 2013

.PRELIMINARY POINT TEMPS/POPS...
DDC 40 54 27 56 / 10 0 0 0
GCK 36 53 27 56 / 0 0 0 0
EHA 34 51 27 57 / 0 0 0 0
LBL 37 53 27 57 / 0 0 0 0
HYS 39 53 25 55 / 40 0 0 0
P28 48 55 30 56 / 80 50 0 0

.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 6 AM CST THURSDAY FOR KSZ030-031-
043>046-063>066-076>081-086>090.

UPDATE...RUSSELL
SYNOPSIS...HOVORKA_42
SHORT TERM...SUGDEN
LONG TERM...JJOHNSON
AVIATION...RUSSELL

AREA FORECAST DISCUSSION

NWS JACKSON KY

1021 PM EST FRI FEB 8 2013

.UPDATE...
ISSUED AT 1020 PM EST FRI FEB 8 2013

CLOUDS CONTINUE TO BE MAIN FORECAST CHALLENGE...AND CONSEQUENTLY
OVERNIGHT LOWS. BASED ON MODELS...AND ESPECIALLY THE RUC IT APPEARS
CLOUDS WILL REMAIN LOCKED IN PLACE FOR THE BULK...IF NOT THE ENTIRE
CWA THROUGH DAWN. WHILE OVERCAST...CLOUD DECK WILL PROBABLY BE VERY
THIN BY DAWN SO EXPECT CLOUDS TO SCOUR OUT QUICKLY AFTER SUNRISE.
EXPECT TEMPS TO RESPOND IN KIND AND PREFERRED TO STICK WITH PREVIOUS
FORECAST WHICH KEPT OVERNIGHT TEMPS UP. ACTUALLY PREVIOUS UPDATE HAD
HOURLY TEMP TRENDS JUST ABOUT PEGGED. ONLY SOME MINOR TWEAKS TO
GRIDS...MAINLY IN FINE TUNING SKY COVER. HOWEVER...SHOULD WE CLEAR
OUT SOONER THAN ANTICIPATED MORNING LOWS WOULD BE A FEW DEGREES
COOLER THAN CURRENTLY ADVERTISED.

UPDATE ISSUED AT 657 PM EST FRI FEB 8 2013

CLOUDS REMAIN LOCKED IN ACROSS THE AREA THIS EVENING. A PATCH OF
PARTIAL CLEARING IS NOTED IN NORTHEAST INDIANA AND NORTHWEST
OHIO...BUT THE TRAJECTORY WILL TAKE THIS CLEARING (IF IT DOESN`T FILL
IN) DUE SOUTH INTO CENTRAL KENTUCKY...KEEPING EASTERN KENTUCKY
LOCKED IN THE CLOUDS FOR THE BALANCE OF THE NIGHT. CLOUDS ARE VERY
SHALLOW AND SHOULD MIX OUT QUICKLY TOMORROW MORNING AS THE 850MB
RIDGE PUSHES EAST ACROSS THE AREA. HOWEVER...UNTIL THEN...EXPECT
CLOUDS TO HOLD ON. THIS WILL KEEP TEMPERATURES A BIT MILDER...BUT
STILL COOLER THAN THE PAST SEVERAL NIGHTS. DEWPOINTS WILL ALSO REMAIN
MUCH HIGHER OVERNIGHT. UPDATE WILL BE OUT SHORTLY.

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 249 PM EST FRI FEB 8 2013

THE COLD FRONT HAS MOVED EAST OF KY...AND COLD AIR ADVECTION ALONG
WITH PLENTY OF LOW CLOUD HAS RESULTED IN FALLING TEMPERATURES
THROUGH THE DAY. TEMPERATURE ADVECTION WILL BECOME NEUTRAL TONIGHT
AND WARM AIR ADVECTION WILL KICK IN ON SATURDAY...SO THIS WILL BE A
VERY BRIEF COLD SPELL.

THERE IS CONSIDERABLE LOW CLOUD ACROSS THE OHIO VALLEY AND WILL HOLD
ONTO OVERCAST TO MOSTLY CLOUDY SKIES INTO THE EARLY PART OF THE
NIGHT. AS HIGH PRESSURE BUILDS INTO THE REGION LATER TONIGHT AND
EARLY SATURDAY DO EXPECT CLOUDS TO SCATTER OUT WITH PLENTY OF
SUNSHINE FOR SATURDAY. AS SURFACE HIGH PRESSURE AND 8H RIDGE SHIFTS
TO THE EAST SATURDAY AFTERNOON WARMER AIR WILL BEGIN MAKING ITS WAY
BACK INTO THE AREA.

CLOUDS WILL BE ON THE INCREASE SATURDAY NIGHT FROM THE SOUTHWEST AS A
WARM FRONT APPROACHES THE AREA. MOSTLY CLEAR SKIES SATURDAY EVENING WILL
RESULT IN THE COLDEST LOWS SATURDAY NIGHT IN THE VALLEYS IN THE EAST.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 249 PM EST FRI FEB 8 2013

THE MODELS ARE IN GOOD AGREEMENT ALOFT TO START THE LONG TERM
PORTION OF THE FORECAST SHOWING STRONG RIDGING NORTH THROUGH THE
EASTERN HALF OF THE NATION AND A DEEP TROUGH CROSSING THE CENTRAL
PLAINS. THIS TROUGH AND ITS TRAILING ENERGY WILL IMPACT EAST
KENTUCKY ON SUNDAY AS ITS MID LEVEL LOW PASSES OVER THE UPPER
MIDWEST ON ITS WAY TO THE NORTHERN GREAT LAKES. AS IT SLIPS PAST
KENTUCKY...HEIGHTS WILL FALL LOCALLY...BUT THE CORE OF ITS ENERGY
WILL STAY TO THE NORTH OF OUR AREA. THE MODELS ARE SIMILAR ENOUGH
WITH THIS THAT A CONSENSUS IS PREFERRED THROUGH MONDAY. HOWEVER...
OVER THE FOUR CORNERS REGION A TRAILING NODE OF THE POSITIVELY
TILTED TROUGH...LOCATED JUST TO OUR NORTHWEST...IS STILL SHOWING A
FAIR AMOUNT OF SPREAD AMONG THE MODELS. HOW THIS FEATURE ROLLS EAST
IN ITS SOUTHERN STREAM FLOW WILL HAVE A POTENTIAL TO IMPACT ON THE
WEATHER THROUGH THE JKL CWA...PARTICULAR SOUTH AND EAST. THE GFS IS
THE DEEPEST WITH THIS WAVE...AS IT MOVES INTO THE AREA EARLY
WEDNESDAY...WHILE THE ECMWF AND GEM ARE FLATTER AND FURTHER SOUTH
WITH THEIR ENERGY. CONTINUE TO FAVOR THE MORE SUPPRESSED ECMWF
SOLUTION AS THE OTHER MODELS HAVE TAKEN A SMALL STEP IN TRENDING
TOWARD IT. THIS WAVE SWEEPS PAST BY THURSDAY WITH RISING HEIGHTS FOR
EAST KENTUCKY INTO FRIDAY. AFTER THAT...BOTH THE ECMWF AND GFS ARE
SHOWING SHARP AMPLIFICATION THROUGH THE MIDDLE OF THE COUNTRY WITH
THE GFS AHEAD OF THE ECMWF AND CLOSING OFF NEARER KENTUCKY LATER IN
THE DAY. WILL PREFER A CONSENSUS HERE AS WELL...BUT ALL INDICATIONS
ARE FOR A DEEP TROUGH BUILDING THROUGH THE MIDDLE OF THE COUNTRY FOR
NEXT WEEKEND.

SENSIBLE WEATHER WILL FEATURE A STACKED LOW ROLLING NORTHEAST INTO
THE UPPER MIDWEST ON SUNDAY. FROM THIS...A SWEEPING WARM FRONT WILL
MOVE EAST INTO KENTUCKY WITH ITS COLD FRONT NEARLY CATCHING UP BY
MIDDAY. THIS WILL BRING MILD TEMPERATURES AND AN AREA OF SHOWERS TO
EAST KENTUCKY INTO SUNDAY NIGHT. A HEALTHY WIND FIELD WITH THE
SYSTEM WILL BE ACCOMPANIED BY LOW INSTABILITY...LIMITING ALL BUT A
SMALL POTENTIAL FOR ELEVATED CONVECTION FROM THE LATTER PART OF THE
DAY SUNDAY AND INTO EARLY MONDAY. FOR NOW...WILL LIKELY LEAVE THIS
POSSIBILITY OUT OF THE GRIDS AND FORECAST. THE FRONT WILL SETTLE TO
THE SOUTH FOR THE START OF THE WORK WEEK...WITH NO REAL PUSH FROM
ITS STALLING PARENT LOW WELL TO THE NORTH. THIS BOUNDARY TO THE
SOUTH WILL PROVIDE AN AVENUE FOR POTENTIAL SFC WAVE DEVELOPMENT BY
MID WEEK AS A MID LEVEL TOUGH AND ITS ENERGY MOVES OUT OF THE
SOUTHERN PLAINS AND INTO THE TENNESSEE VALLEY AND DEEP SOUTH. THE
TRENDS HAVE BEEN FOR ANY DEVELOPMENT TO TAKE PLACE SOUTH OF THE AREA
SO WILL CONTINUE TO MINIMIZE ITS IMPACT OVER THE BULK OF THE
CWA...JUST ALLOWING A BRUSH BY IN THE FAR SOUTHEAST. ANY PCPN THAT
FALLS OVER THE AREA TUESDAY NIGHT INTO WEDNESDAY COULD BE MIXED WITH
SNOW...DEPENDING ON HOW STRONG THE LOW TO OUR SOUTH ENDS UP. IT
SHOULD BE NOTED...THOUGH...THAT THE GFS HAS CONTINUED TO POINT TO A
POTENTIAL FOR SOME ACCUMULATIONS OF SNOW FROM LATE TUESDAY NIGHT
INTO WEDNESDAY. THIS WILL HAVE TO BE MONITORED. MILD WEATHER FOLLOWS
THROUGH THURSDAY NIGHT...BUT THAT CHANGES ON FRIDAY AS THE NEXT
ARCTIC OUTBREAK LOOKS TO DESCEND INTO THE GREAT PLAINS AND HEADS
THIS WAY. IT IS STILL AN OPEN QUESTION IN THE MODELS WHETHER IT
PUSHES INTO OUR AREA ON THE HEELS OF A POTENT SYSTEM MOVING THROUGH
THE OHIO VALLEY...ALA THE GFS...OR MORE OF A BACK DOOR COLD FRONT
PRESSING INTO KENTUCKY FROM THE NORTH AS SEEN IN THE ECMWF. EITHER
WAY COLDER WX...AND PROBABLY MORE SNOWY TOO...LOOKS TO BE ON DECK
STARTING NEXT WEEKEND.

THE CR GRID LOAD CAME IN DECENT WITH RESPECT TO THE POP AND SKY
DEPICTIONS THROUGH THE EXTENDED...MOSTLY IN LINE WITH THE PREFERRED
SOLUTION COMBINATION. DID MAKE SOME ADJUSTMENTS TOWARD THE LATEST
ECMWF FOR THE POPS FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
SUPPRESSING THE GFS SCENARIO. ALSO WILL BE MAKING SOME SMALL TERRAIN
BASED TWEAKS TO THE LOW TEMPERATURES FOR MOST OF THE NIGHTS AFTER
MONDAY.

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 657 PM EST FRI FEB 8 2013

MVFR CIGS WILL LIKELY HOLD THROUGH TONIGHT AS STUBBORN LOW LEVEL
MOISTURE REMAIN ACROSS THE AREA. AS A MID LEVEL RIDGE PUSHES ACROSS
THE AREA TOMORROW MORNING...SKIES WILL CLEAR OUT GIVING WAY TO VFR
CONDITIONS. LIGHT NORTHWEST WINDS WILL LIKELY GO LIGHT AND VARIABLE
OR CALM BY TOMORROW MORNING.

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

UPDATE...RAY
SHORT TERM...SBH/KAS
LONG TERM...GREIF
AVIATION...KAS

AREA FORECAST DISCUSSION

NWS PADUCAH KY

258 PM CST THU FEB 7 2013

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 257 PM CST THU FEB 7 2013

BASED ON CURRENT RADAR...LINE OF SHOWERS WILL REACH FAR WESTERN
PORTIONS OF THE PAH FORECAST AREA AROUND 22Z...SPREADING ACROSS
SOUTHEAST MISSOURI INTO SOUTHERN ILLINOIS BETWEEN 00Z AND
02Z...REACHING FAR WEST KENTUCKY AND SOUTHWEST INDIANA BETWEEN 02Z
AND 03Z...THEN INTO THE PENNYRILE REGION OF WEST KENTUCKY LATE
THIS EVENING. THE NAM12 AND RUC LINE UP WELL WITH THIS
TIMING...AND THE NAM HAS PRECIP CLEARING THE PAH FA BY 12Z FRIDAY.
HAVE LIKELY TO CATEGORICAL POPS ACROSS THE ENTIRE FA FOR A LEAST A
FEW HOURS SHIFTING FROM WEST TO EAST BETWEEN 00Z AND 10Z. INCLUDED
SOME ISOLATED THUNDER CHANCES ACROSS THE SOUTHERN HALF OF THE
REGION THIS EVENING BASED ON LIGHTNING DATA OCCASIONALLY SHOWING A
FEW STRIKES IN SOUTHERN MISSOURI AND NAM AND SREF SHOWING NEAR
ZERO LI`S MAKING IT INTO THE AREA....ESPECIALLY IN SOUTHEAST
MISSOURI. ANY THUNDER POSSIBILITY SHOULD END BY MIDNIGHT.

DRY AND COOLER WEATHER IS EXPECTED FRIDAY INTO FRIDAY NIGHT AS
HIGH PRESSURE SLIDES THROUGH THE GREAT LAKES REGION. RH TIME
HEIGHTS SHOW VERY DRY AIR ACROSS THE REGION...SO WE SHOULD SEE
LOTS OF SUNSHINE ON FRIDAY AND MOSTLY CLEAR SKIES INTO FRIDAY
NIGHT. TEMPERATURES WILL BE NEAR SEASONAL FRIDAY AND FRIDAY
NIGHT...THEN A FEW DEGREES WARMER FOR SATURDAY.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 257 PM CST THU FEB 7 2013

00Z AND 12Z RUNS CONFIRM A FASTER APPROACH/PASSAGE OF THE WEEKEND
WEATHER SYSTEM OF NOTE. THE 12Z GFS IS NOW TRACKING THE SURFACE AND
UPPER LOWS FROM THE PLAINS STATES...NORTHEASTWARD TO THE GREAT
LAKES...A SUBTLE NORTHWARD SHIFT MORE AKIN TO THE 12Z YESTERDAY AND
00Z EURO TRACKS. BOTH MODELS PUSH THE FRONT OUT AHEAD AND SPEED UP
THE INTRO/PASSAGE/DEPARTURE OF PCPN FOR OUR AREA. THIS WILL
TRANSLATE TO INTRODUCTORY POPS SAT NIGHT...PEAK POPS SUNDAY...WITH
ENDING/DEPARTURE POPS SUNDAY NIGHT.

THE SYSTEM WILL HAVE MAINLY ELEVATED INSTABILITY...WITH THE MAX
SURFACE INSTABILITY AXIS FOCUSED ALONG THE LOWER MS VALLEY TO THE
GULF COAST. THIS IS BASED ON A RIBBON OF 50F TD MAKING ITS WAY INTO
OUR AREA...AND THIS AXIS COULD EXTEND FURTHER NORTHWARD IF TDS DO IN
FACT CLIMB HIGHER. STILL...WITH THE COLD FRONT INCOMING...AND
POWERFUL WIND FIELDS ALOFT...A DAMAGING WIND THREAT WILL ACCOMPANY
STORMS SHOULD THEY DEVELOP/BECOME SVR. BRN MAG TO 100KTS MIGRATES
ACROSS THE FA WITH THE SYSTEM/WHILE WEAK BULLSEYES OF 0-2KM VORT GEN
AND LAYER TOR PARAMETERS SUGGEST ISOLD TORS ARE POSSIBLE TOO. WILL
CONTINUE THE HIGHLIGHT OF THIS POSSIBILITY VIA THE HWO.

WITH POWERFUL WINDS PROPELLING THE SYSTEM THRU...WE SHOULD SEE QUICK
BURST QPF OF 1/2 TO 1 INCH ON AVERAGE FOR THE BASINS. HOWEVER...WITH
GFS SOUNDINGS REVEALING 1-1.25" PW`S PUSHING THE 99TH PERCENTILE FOR
THIS TIME OF YEAR...LOCALIZED HEAVIER RAINFALL COULD CREATE SOME
FLOOD ISSUES/OR AT LEAST CAUSE HEIGHTENED CONCERN/SOMETHING TO KEEP
AN EYE UPON.

MONDAY-TUESDAY...THE MODELS BACK OFF SOMEWHAT ON THE
STALLED/RETURNING BOUNDARY SCENARIO ACROSS OUR SOUTHERN COUNTIES. SO
WE`LL CONTINUE TO OMIT FOR THIS PACKAGE...AND WE`LL GO AHEAD AND
KEEP THE CLEAN FROPA AND RETURN POPS IF/WHEN NEEDED...IF FUTURE RUNS
SUGGEST SO. ONE SUCH TIME IS TUESDAY NIGHT. WE WENT SLGT CHC PCN AS
2NDARY TROF/LOW ROTATES ACROSS AREA. GIVEN THERMAL PROFILE AT THAT
TIME/WE CARRY EITHER/OR -RA/-SN. MINIMAL QPF EVENT BUT ALL
CONSIDERED AND WITH COLLAB...CURSORY SLGT CHC WARRANTED FOR NOW.

THE WARM PRE-FRONTAL ENVIRO WILL COOL FROM HIGHS IN THE 50S/NR 60
EARLY...BACK TO THE MORE FEBRUARY LIKE 40S BY MID WEEK. LOWS WILL
RESPOND IN KIND...RETURNING CLOSER TO NORMS BY THEN AS WELL.

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 257 PM CST THU FEB 7 2013

LOW LEVEL MOIST ADVECTION AHEAD OF THE APPROACHING COLD FRONT MAY
YIELD TEMPO MVFR CIGS LATE THIS PM...BUT GENERALLY...VFR WILL CARRY
THE DAYLIGHT HOURS. AFTER NIGHTFALL...EXPECT DETERIORATING
CONDITIONS TO MVFR CIGS/VSBYS WITH RAIN CHANCE ONSET AS COLD FRONT
ENTERS FLIGHT ZONES. FROPA BY MID EVENING WILL SHIFT WINDS TO N-NWLY
OVERNIGHT WITH ACCOMPANYING GUSTS TO 20 KTS AT TIMES. SOME CHANCE OF
EMBEDDED HEAVIER RAIN REDUCING CIGS/VSBYS TO IFR FOR A BRIEF WINDOW
OF TIME IN THE EVENING...OTHERWISE MVFR CONDITIONS SHOULD IMPROVE TO
VFR BY LATE IN THE PLANNING PERIOD.

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&

SHORT TERM...RST
LONG TERM...DH
AVIATION...DH

AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

503 AM EST THU FEB 7 2013

.SYNOPSIS...
HIGH PRESSURE WILL SHIFT EAST OF THE AREA TODAY. A LOW PRESSURE
SYSTEM WILL APPROACH FROM THE WEST TONIGHT AND BRING A WINTRY MIX
TO PORTIONS OF THE AREA AS IT CROSSES THE REGION ON FRIDAY. HIGH
PRESSURE WILL THEN BUILD IN FROM THE WEST AND ALLOW FOR A DRY
WEEKEND.

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A ZONAL FLOW WITH 500MB MOISTURE ADVECTING INTO THE AREA FROM
THE WEST. AT THE SURFACE...A 1030MB HIGH IS CENTERED OVER THE
JERSEY COAST...WITH A BROAD AREA OF HIGH PRESSURE EXPANDING
WESTWARD INTO THE AREA. INFRARED SAT IMAGERY INDICATES THAT CLEAR
SKIES HAVE GIVEN WAY TO UPPER LEVEL CLOUD COVERAGE THAT HAS
MOVED INTO THE AREA FROM THE SOUTHWEST.

TODAY...THE SURFACE HIGH WILL CONTINUE TO SHIFT EAST OF THE AREA.
MEANWHILE...FURTHER UPSTREAM...AN INVERTED TROUGH OF LOW PRESSURE
WILL SLIDE INTO THE LOWER GREAT AS ANOTHER LOW DEVELOPS ACROSS THE
SOUTHERN PLAINS. 750-250MB LAYER MOISTURE ASSOCIATED WITH THIS
SYSTEM WILL SPILL INTO THE AREA...WITH SKIES BECOMING OVERCAST.
ALTHOUGH INCREASING CLOUDINESS WILL BE AN INHIBITOR TO HEATING
TODAY...WAA ADVECTION WILL ENSUE AS A LOW-LEVEL RIDGE SHIFTS EAST
OF THE AREA AND THE LOW-LEVEL FLOW BECOMES SOUTHWESTERLY. THE
SURFACE WINDS WILL SHIFT TO SOUTHEASTERLY...FAVORING DOWNSLOPE
ENHANCEMENT WITH WINDS BEGINNING TO PICK UP ON THE WEST-FACING
SLOPES BEGINNING THIS EVENING.

WITH WAA TODAY...TEMPS WILL WARM ABOVE FREEZING ACROSS THE ENTIRE
FORECAST AREA FOR THE FIRST TIME THIS MONTH. HIGHS ARE A MAV/MET
BLEND...RANGING FROM THE MID 30S ALONG THE I-80 CORRIDOR AND
LAUREL HIGHLANDS/ALLEGHENY FRONT TO THE MID 40S IN PORTIONS OF
EASTERN OHIO AND NORTHERN WV.

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A MODEL CONSENSUS INDICATES A BROAD NORTHERN STREAM TROUGH
AMPLIFYING AND STRENGTHENING AS ITS AXIS MOVES FROM THE UPPER
MIDWEST ACROSS THE GREAT LAKES ON FRIDAY AND INTO THE UPPER OHIO
VALLEY BY FRIDAY EVENING. AS THE TROUGH SHIFTS EAST OF THE AREA...IT
WILL THEN UNDERGO FURTHER INTENSIFICATION AS ITS ENERGY SHIFTS
EASTWARD AND PHASES WITH A COASTAL LOW. THE TWO FEATURES WILL THEN
BECOME A DEEP...CLOSED LOW OFF THE NEW ENGLAND COAST EARLY ON
SATURDAY. AT THE SURFACE...MODELS REMAIN IN STRONG AGREEMENT WITH
A LOW AND ITS ASSOCIATED COLD FRONT SWEEPING ACROSS THE OHIO
VALLEY THURSDAY NIGHT AND PUSHING ACROSS OUR AREA EARLY ON FRIDAY.

THE UPPER OHIO VALLEY WILL REMAIN DRY THROUGH THE MAJORITY OF
THURSDAY NIGHT IN A DRY SLOT OF WAA AS A WEDGE OF 2-4C 850MB TEMPS
SURGES INTO THE AREA. A SOUTHEASTERLY FLOW IN WAA WILL ENHANCE
DOWNSLOPING AND ALLOW FOR WINDS AT 15-20MPH WITH GUSTS TO 35MPH FOR
THE WESTWARD FACING SLOPES OF CHESTNUT AND LAUREL RIDGES.

THE ONSET OF PRECIP LOOKS TO NOT BE UNTIL AFTER 06Z FRIDAY IN
EASTERN OHIO AND BY AROUND 12Z FOR THE PITTSBURGH METRO AND
LOCATIONS EASTWARD AS FORCING WITH THE COLD FRONT MOVES INTO THE
AREA. POPS QUICKLY INCREASE TO CATEGORICAL WITH THE PASSAGE OF THE
FRONT ON FRIDAY. WITH WAA ONGOING THURSDAY NIGHT...LOWS RANGE FROM
THE LOW TO MID 30S ACROSS THE AREA. WENT WITH A NAM/SREF BLEND FOR
TEMPS ON FRIDAY...WITH HIGHS RANGING FROM THE MID 40S IN NORTH-
CENTRAL WV TO THE MID 30S NORTH OF THE I-80 CORRIDOR.

FOR PRECIP TYPE...THE TIMING OF THE ONSET OF PRECIP ON FRIDAY WILL
BE CRITICAL IN THIS EVENT. MODEL SOUNDINGS INDICATE A MELTING LAYER
IN THE 06Z-15Z FRIDAY TIME FRAME WARM ENOUGH FOR MOST PRECIP TO
REACH THE GROUND AS LIQUID ACROSS THE AREA. THUS...IF PRECIP STARTS
EARLIER THAN 12Z...FREEZING RAIN COULD BECOME AN
ISSUE...PARTICULARLY NORTHEAST OF PITTSBURGH AND ACROSS THE LAUREL
HIGHLANDS/ALLEGHENY FRONT OF WV/PA/MD. IF PRECIP STARTS AFTER
12Z...MOSTLY RAIN IS ANTICIPATED BEFORE THE CHANGE BACK OVER TO SNOW
BEHIND THE FRONT (AFTER 18Z FRIDAY). GIVEN THE SUPPORT OF SREF
PROBABILITIES AND THE 00Z NAM...THE CHANCE OF FREEZING RAIN IS
FORECAST NEAR DAWN FOR THE RIDGES AND LOCATIONS NORTHEAST OF
PITTSBURGH THROUGH UNTIL 14Z. WITH THE POSSIBILITY OF A LIGHT ICING
THERE...THE MENTION OF THIS REMAINS IN THE HWO.

BEHIND THE FRONT ON FRIDAY AND FRIDAY NIGHT...CAA WILL ENSUE WITH 850MB
TEMPS QUICKLY COOLING TO THE -5C TO -10C RANGE. THIS WILL ALLOW PRECIP
TO TURN OVER TO ALL SNOW ACROSS THE AREA FOR FRIDAY EVENING. QPF
IS ANTICIPATED TO BE AROUND A QUARTER OF AN INCH ON FRIDAY...ALTHOUGH
MOST OF THIS SHOULD FALL IN THE FORM OF LIQUID. IN THE WAKE OF THE
FRONT...GENERALLY ANTICIPATE AN INCH OR LESS OF ACCUMULATION ACROSS
THE PITTSBURGH METRO AND SOUTHWARD. A MORE BROAD RANGE OF 1 TO 3
INCHES IS FORECAST NORTH OF PITTSBURGH WITH A LONGER PERIOD OF
SNOW. THERE IS STILL SOME UNCERTAINTY IN THE 12Z-18Z TIME FRAME
FRIDAY IN REGARDS TO HOW FAR WARM WEDGE OF AIR WILL SHIFT
NORTHWARD AND LIMIT SNOW AMOUNTS NORTH OF PITTSBURGH. SNOW WILL
QUICKLY COME TO AN END AFTER 00Z SATURDAY AS LOW-LEVEL RIDGE OF
HIGH PRESSURE BUILDS IN FROM THE WEST AND A MOSTLY FROZEN LAKE
ERIE LACKS AS A MOISTURE SOURCE.

MODELS REMAIN IN AGREEMENT THAT HIGH PRESSURE WILL MOVE OVER THE
AREA ON SATURDAY...ALLOWING FOR A DRY FORECAST AND A PERIOD OF
SUNSHINE DURING THE DAY. DESPITE THE RIDGE BUILDING IN...A
COLD...NORTHERLY FLOW TO THE WEST OF THE COASTAL LOW WILL LIMIT
HIGHS ON SATURDAY TO AROUND 5 DEGREES BELOW NORMAL.

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MODELS HAVE BEEN CONSISTENT IN DVLPMNT OF SPLIT FLOW OVR THE CONUS
THIS WEEKEND WITH RIDGING OVR THE GREAT LAKES AND UPR OH REGIONS.
TEMP MODERATION THUS RMNS ON TRACK WITH READINGS APPROX 10 DEGREES
ABOVE THE AVERAGES FORECAST FOR THE BGNG OF THE NEW WEEK USING
TWEAKED ECMWF GUIDANCE AND PERSISTENCE. INITIALLY DRY WEATHER IS
EXPECTED TO DETERIORATE THOUGH AS LOW PRES DVLPS TWD THE GREAT LAKES.

HIGH AMPLITUDE CNTRL CONUS TROF IS PROGGED TO SLIDE EWD AS MID
WEEK APPROACHES...HENCE TEMPS SHOULD FADE BACK TWD THE SEASONAL
AVERAGES. HOWEVER...POPS WL BE DEPENDENT ON TIMING OF SHRTWVS
MOVING THROUGH THE SWLY FLOW ON THE ERN FLANK OF THAT TROF. HAVE
THUS FORECASTED LATE MON THRU WEDNESDAY POPS NR CHC CLIMO NMBRS
FOR NOW.

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
CLEAR SKIES CAN BE EXPECTED OVERNIGHT WITH GENERAL VFR CONDITIONS.
INCREASING MIDDLE CLOUDS ARE FORECAST AFTER SUNRISE INTO THIS
AFTERNOON. LIGHT WINDS CAN BE EXPECTED THROUGH THE TAF PERIOD.

.OUTLOOK.../THURSDAY NIGHT THROUGH MONDAY/...
LOW PRES AND THE ASSOCIATED CDFNT WILL DETERIORATE CONDITIONS ONCE
AGAIN FOR THURSDAY NIGHT AND FRIDAY. HIGH PRES WILL RETURN VFR FOR
THE WEEKEND. ANOTHER SYSTEM WILL BRING WIDESPREAD RESTRICTIONS
SUNDAY NIGHT INTO MONDAY.

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

SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
SHORT TERM...WOODRUM
AVIATION...RSD

AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

204 AM EST THU FEB 7 2013

.SYNOPSIS...
HIGH PRESSURE WILL SHIFT EAST OF THE AREA TODAY. A LOW PRESSURE
SYSTEM WILL APPROACH FROM THE WEST TONIGHT AND BRING A MIX OF
RAIN AND SNOW TO THE AREA AS IT CROSSES THE AREA ON FRIDAY. HIGH
PRESSURE WILL THEN BUILD IN FROM THE WEST AND ALLOW FOR A DRY
WEEKEND.

.NEAR TERM /THROUGH TODAY/...
AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ACCOUNT
FOR THE LATEST TRENDS IN TEMP AND SKY. WINDS WERE ALSO INCREASED
FOR THIS EVENING IN THE DOWNSLOPE AREAS OF THE WEST-FACING SLOPES
OF CHESTNUT/LAUREL RIDGES.

THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A
ZONAL FLOW WITH 500MB MOISTURE BEGINNING TO ADVECT INTO THE AREA
FROM THE WEST. AT THE SURFACE...A 1030MB HIGH IS CENTERED OVER THE
JERSEY COAST...WITH A BROAD AREA OF HIGH PRESSURE EXPANDING WESTWARD
INTO THE AREA. INFRARED SAT IMAGERY INDICATES CLEAR SKIES GIVING
WAY TO UPPER LEVEL CLOUD COVERAGE THAT IS ENCROACHING THE AREA FROM
THE SOUTHWEST.

TODAY...THE SURFACE HIGH WILL CONTINUE TO SHIFT EAST OF THE AREA.
MEANWHILE...FURTHER UPSTREAM...AN INVERTED TROUGH OF LOW PRESSURE
WILL SLIDE INTO THE LOWER GREAT AS ANOTHER LOW DEVELOPS ACROSS THE
SOUTHERN PLAINS. 750-250MB LAYER MOISTURE ASSOCIATED WITH THIS
SYSTEM WILL SPILL INTO THE AREA...WITH SKIES BECOMING MOSTLY CLOUDY
BY THIS AFTERNOON. ALTHOUGH INCREASING CLOUDINESS WILL BE AN
INHIBITOR TO HEATING TODAY...WAA ADVECTION WILL ENSUE AS A LOW-LEVEL RIDGE
SHIFTS EAST OF THE AREA AND THE LOW-LEVEL FLOW BECOMES
SOUTHWESTERLY. A SOUTHEASTERLY FLOW WILL FAVOR DOWNSLOPE
ENHANCEMENT WITH WINDS BEGINNING TO PICK UP ON THE WEST-FACING
SLOPES BEGINNING THIS EVENING.

.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS LOW PRESSURE TRACKS ACROSS THE GREAT LAKES EXPECT LIGHT
PRECIPITATION TO SPREAD ACROSS REGION AS THURSDAY NIGHT
PROGRESSES. MODEL THICKNESS AND 850MB TEMPS SHOW SNOW AT THE START
BUT AS FORECAST SOUNDINGS SHOW WARMING INTO FRIDAY MORNING EXPECT
A FAIRLY QUICK CHANGE TO RAIN ACROSS ALL BUT MOST NORTHERN
LOCATIONS.

FOR THE RIDGES EAST AND SOUTHEAST LOW LEVEL FLOW WILL BE SOUTHEAST
WHICH IS NOT A GREAT DIRECTION FOR COLD AIR DAMMING BUT MODELS DO
KEEP COLD LOW LEVELS ALONG AND EAST OF THE HIGHEST SLOPES LATER
THURSDAY NIGHT AND FRIDAY MORNING. QUESTION IS IF ANY
PRECIPITATION WILL OCCUR AS ONLY EASTERLY UPSLOPE SEEMS TO BE
DRIVER OF ANY POSSIBLE FREEZING RAIN OR DRIZZLE. HAVE LEFT THIS
CHANCE IN FORECAST AND LATER SHIFTS MAY BE ABLE TO PIN THIS DOWN
FURTHER.

OTHERWISE AS PARENT SYSTEM MOVES TO THE EASTERN LAKES FAST
DEVELOPING COASTAL LOW WILL BE NEAR THE CAROLINA COAST FRIDAY
MORNING. THESE SYSTEMS WILL PHASE OFF THE NEW ENGLAND COAST BY
FRIDAY EVENING AND TAKE DEEP MOISTURE WELL EAST OF REGION WITH COLD
AND DRY AIR PUSHING BACK SOUTHWARD FRIDAY NIGHT.

WITH FIRST LOW PRESSURE SYSTEM WEAKENING IN THE COASTAL STORMS
SHADOW FRIDAY NOT A GREAT DEAL OF QPF LEFT FOR OUR REGION. MIXED
RAIN AND SNOW FRIDAY AFTERNOON WILL SWITCH TO ALL SNOW LATE FRIDAY
AFTERNOON AND THEN QUICKLY END FRIDAY EVENING.

ALONG AND NORTH OF I-80 1 TO 3 INCHES OF SNOW POSSIBLE FROM
THURSDAY LATE NIGHT TO WHEN THE SNOW ENDS FRIDAY EVENING. AN INCH
POSSIBLE IN THE RIDGES WITH A COATING ELSEWHERE.

COLD ADVECTION FRIDAY NIGHT WILL DROP TEMPERATURES WELL INTO THE
TEENS AS 850MB TEMPS FALL BUT FLOW WILL BE BECOMING NORTH TO
NORTHEAST WITH LITTLE OR NO LAKE EFFECT.

BY SATURDAY COLD AND DRY HIGH PRESSURE WILL BRING SUNSHINE WITH BELOW
NORMAL TEMPERATURES.

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
CLEAR SKIES CAN BE EXPECTED OVERNIGHT WITH GENERAL VFR CONDITIONS.
SOME PATCHY FOG IS POSSIBLE...MAINLY AT KMGW AND KZZV. INCREASING
MIDDLE CLOUDS ARE FORECAST AFTER SUNRISE INTO THIS AFTERNOON. LIGHT
WINDS CAN BE EXPECTED THROUGH THE TAF PERIOD.

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

SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...RSD

AREA FORECAST DISCUSSION

NWS DETROIT/PONTIAC MI

330 PM EST THU FEB 7 2013

.SHORT TERM...THIS EVENING THROUGH FRIDAY

COMPACT WAVE ALONG THE SOUTHERN PERIPHERY OF THE NORTHERN STREAM IS
CLIPPING EAST/SOUTHEAST THROUGH THE WESTERN GREAT LAKES THIS
AFTERNOON. LOWER TROPOSPHERIC FLOW HAS INCREASED IN ADVANCE OF THIS
FEATURE ALONG THE MID-MISSISSIPPI VALLEY MANIFESTING IN A BROAD
REGION OF RAIN ACROSS ILLINOIS SOUTH INTO ARKANSAS WITH SNOW
SPREADING ACROSS WISCONSIN AND FAR WESTERN LOWER MICHIGAN.
MID-LEVEL FORCING REMAINS IN PLACE ACROSS THE SAGINAW VALLEY /AS
EVIDENCED BY LOW-LEVEL WATER VAPOR IMAGERY/ WAITING FOR MOISTURE
TRANSPORT TO ARRIVE. EXPECTING SATURATION TO OCCUR WITHIN THIS ZONE
OF FORCING BY SUNDOWN...AFTER WHICH ACCUMULATING SNOWFALL WILL
QUICKLY FOLLOW.

MEANWHILE...THE WELL ESTABLISHED MOISTURE PLUME IS WAITING ON THE
UPPER-LEVEL PV ANOMALY OVER MINNESOTA TO LINK UP AND SHOULD BEGIN TO
BREAK TOWARD THE EAST THIS EVENING. CONSEQUENTLY...THE ONSET OF
MEANINGFUL SNOW SOUTH OF THE SAGINAW VALLEY WILL BE DURING THE LATE
EVENING HOURS AS THE WARM/MOIST CONVEYOR BELT FINALLY ARRIVES. IN
FACT...THE 07.18 RAP SUGGESTS PRECIPITATION ONSET WILL BE LAGGING
UNTIL AROUND MIDNIGHT IN MANY LOCATIONS. FURTHERMORE...12Z GUIDANCE
SUITE IS TOO BULLISH ON PRECIPITATION DURING THE FIRST 12 HOURS OF
THE FORECAST...OWING TO THE LACK OF DEEP MOISTURE TRANSPORT THUS FAR.

THE DURATION OF THE EVENT WILL CERTAINLY LIMIT ACCUMULATIONS SOUTH
OF THE MID-LEVEL FRONTAL FORCING...WHERE THE PRIMARY MECHANISM WILL
BE A QUICK BUT STRONG SHOT OF ISENTROPIC ASCENT ASSOCIATED WITH THE
SHARPENING MID-LEVEL ANOMALY. STILL EXPECT A GOOD BURST OF
PRECIPITATION /SNOW RATES IN THE INCH PER HOUR NEIGHBORHOOD/ GIVEN
THE SYSTEM WILL STILL BE DEEPENING AS IT TRAVERSES THE SOUTHERN
LAKES REGION. TO ADD FUEL TO THE RATES...THERE IS STILL THE
POTENTIAL FOR SOME CONVECTIVE CONTRIBUTION CLOSER TO THE 850MB LOW
TRACK...WHERE DIFFERENTIAL ADVECTIONS WILL DESTABILIZE THE PROFILE.

STILL PLENTY OF EVIDENCE TO SUPPORT A MIXTURE OF PRECIPITATION TYPES
ACROSS THE METRO DETROIT REGION SOUTH TO THE OHIO BORDER. THE BEST
OPPORTUNITY FOR FREEZING RAIN AND SLEET WILL BE NEAR THE ONSET OF
PRECIPITATION...BEFORE THE COLUMN SUCCUMBS TO COOLING VIA STRONG
ASCENT ALONG THE LEAD EDGE OF THE PV ANOMALY.

ON FRIDAY...SOME LIGHT SNOW WILL CONTINUE THROUGH THE MORNING AS
MID-LEVEL DEFORMATION LINGERS FOR SEVERAL HOURS. CLOSER TO LAKE
HURON...THE INCREASING NORTHEASTERLY FLOW WILL HELP BOOST SNOW
TOTALS ALONG THE IMMEDIATE LAKESHORE.

HIGH PRESSURE WILL QUICKLY BUILD INTO THE REGION BY LATE FRIDAY AND
TEMPERATURES WILL HOVER IN THE 20S MOST OF THE DAY UNDER THE
INFLUENCE OF MODEST COLD ADVECTION.

.LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY

HIGH PRESSURE AT THE SURFACE AND UPPER RIDGING ALOFT WILL SLIDE
ACROSS MICHIGAN FRIDAY NIGHT THROUGH EARLY SUNDAY...BRINGING CALMER
WEATHER TO THE AREA. WARMER AND MUCH DRIER AIR ALOFT WILL START TO
PUSH IN BY FRIDAY EVENING...EFFECTIVELY LOWERING INVERSION HEIGHTS
AND STRIPPING AWAY ICE NUCLEI...ENDING POTENTIAL FOR LAKE EFFECT
SNOW TO AFFECT THE THUMB. DECREASING CLOUDS AND WINDS FRIDAY NIGHT
OVER THE FRESH SNOWPACK WILL ALLOW FOR GOOD RADIATIONAL
COOLING...AND DID CONTINUE TO UNDERCUT GUIDANCE SLIGHTLY...WITH
FORECAST MINS IN THE SINGLE DIGITS TO LOW TEENS ACROSS THE AREA.
MODELS START TO SHOW A STRONGER SURGE OF WARMER AIR ARRIVING BETWEEN
925-850MB SATURDAY NIGHT...HOWEVER SNOWPACK AND STRONG SUBSIDENCE
INVERSION SHOULD KEEP SURFACE TEMPERATURES COOL AS THE BOUNDARY
LAYERS REMAINS DECOUPLED. ONCE AGAIN...CONTINUED TO UNDERCUT MOS
GUIDANCE VALUES WITH MINS ONLY SLIGHTLY WARMER THAN FRIDAY NIGHT.

ENERGY NOW OFF THE PACIFIC NORTHWEST COAST WILL MAKE ITS WAY INTO
THE CENTRAL PLAINS ON SUNDAY AND THEN ACROSS THE GREAT LAKES MONDAY.
STRONG UPPER DIFFLUENCE AND UPPER HEIGHTS FALLS LEE OF THE ROCKIES
WILL SPIN UP A FAIRLY STRONG LOW PRESSURE SYSTEM. LATEST CONSENSUS
FROM MEDIUM-RANGE MODELS TRACKS THE SURFACE LOW ACROSS NORTHERN
MICHIGAN MONDAY. 50 KT LOW LEVEL JET PRECEDING THE SYSTEM WILL FEED
WARMTH AND MOISTURE (PW AROUND 0.8 INCHES) UP INTO LOWER MICHIGAN
STARTING SUNDAY AFTERNOON. IT APPEARS MOST PRECIPITATION WILL HOLD
OFF UNTIL VERY LATE IN THE DAY AND OVERNIGHT WHEN STRONGER
ISENTROPIC ASCENT AND UPPER DIVERGENCE WILL OVERSPREAD THE AREA.
STRONGER FORCING SHOULD ALSO COINCIDE WITH WARMING SURFACE
TEMPERATURES PER LATEST TRENDS IN THE EURO AND GFS...AND EXPECT
MOSTLY RAIN TO FALL OUT OF THIS SYSTEM. COLD FRONT WILL PUSH THROUGH
THE AREA EARLY MONDAY...CHANGING PRECIPITATION TO SNOW. STRONG DRY
SLOT PRECEDING THE FRONT IN ADDITION TO DRIER AIR ALOFT STRIPPING
AWAY ICE NUCLEI BEHIND THE FRONT WILL KEEP POTENTIAL FOR SNOW
ACCUMULATIONS LOW.

NORTHWEST FLOW AND PATTERN OF VERY WEAK CLIPPER SYSTEMS THEN LOOKS
TO BECOME ESTABLISHED TUESDAY THROUGH THURSDAY. LATEST EURO AND GFS
HINT AT A STRONGER SYSTEM WORKING ACROSS THE GREAT LAKES LATE ON
THURSDAY...BUT MODEL TO MODEL AND RUN TO RUN CONSISTENCY HAS BEEN
POOR AND WILL LEAVE MENTION OUT OF FORECAST FOR NOW. EARLIER SYSTEM
THE GFS HAD ADVERTISED CLIPPING THE SOUTHERN PORTION OF MICHIGAN
MID-WEEK NOW LOOKS TO TRACK FURTHER SOUTH AS UPPER LEVEL ENERGY
DIVES FURTHER INTO THE U.S. FROM CANADA.

.MARINE...

A LOW PRESSURE SYSTEM WILL STRENGTHEN AS IT TRACKS ACROSS THE
SOUTHERN GREAT LAKES THIS EVENING AND TONIGHT. THIS SYSTEM WILL
CONTINUE EASTWARD EVENTUALLY BEING ABSORBED BY A STRONGER NOREASTER
ALONG THE ATLANTIC COAST FRIDAY NIGHT. THE GRADIENT WILL TIGHTEN
OVERNIGHT AS EASTERLY WINDS INCREASE AND BACK TO THE NORTHEAST.
WINDS WILL INCREASE TO AROUND 25 KNOTS SUSTAINED OVERNIGHT
NECESSITATING BRISK WIND ADVISORIES FOR ALL NEARSHORE ZONES. THE
EXCEPTION WILL BE SAGINAW BAY WHERE A GALE WARNING HAS BEEN ISSUED
AS WINDS FUNNEL DOWN THE BAY WITH THE FAVORABLE NORTHEAST FETCH.
SOME FREEZING SPRAY WILL BE POSSIBLE ACROSS NORTHERN LAKE HURON WITH
THE COOLER TEMPERATURES AND SLIGHTLY STRONGER FLOW TONIGHT...BUT
INTENSITY AND DURATION SHOULD STAY BELOW WARNING CRITERIA. AFTER
HIGH PRESSURE RETURNS TO THE REGION FOR MUCH OF THE WEEKEND...THE
NEXT LOW PRESSURE SYSTEM WILL TARGET THE REGION SUNDAY NIGHT.

.AVIATION...ISSUED 1250 PM EST THU FEB 7 2013

//DISCUSSION...

LOW PRESSURE SYSTEM TRACKING ACROSS THE MI/OH BORDER WILL BRING
DETERIORATING CONDITIONS TO ALL OF SE MI TONIGHT. INITIAL DROP TO
VSBY/CIGS WILL BE AT MBS WHERE LIGHT SNOW SHOWERS WILL BEGIN THIS
AFTERNOON...SPREADING SE WITH TIME THROUGH THIS EVENING. SHORTLY
AFTER MIDNIGHT INTENSITIES WILL INCREASE AND THE HEAVIEST SNOW WILL
BEGIN TO FALL BRINGING IFR CONDITIONS. SNOW SHOWERS WILL TAPER OFF
THROUGH THE MORNING HOURS ON FRIDAY. FREEZING RAIN OR SLEET WILL BE
POSSIBLE AT THE ONSET FOR THE DETROIT METRO AREA...CHANGING TO SNOW
WHEN THE DEEPER MOISTURE ARRIVES.

FOR DTW...DRY AIR WILL PRODUCE VFR CONDITION THROUGH THIS AFTERNOON
BEFORE TURNING TO IFR OVERNIGHT. WARM TEMPERATURES IN THE LOW LEVELS
WILL LIKELY PRODUCE A PERIOD OF FREEZING RAIN OR SLEET AT THE
ONSET OF PRECIPITATION TONIGHT WHICH WILL CHANGE TO SNOW AS
INCREASED SATURATION COOLS THE AIRMASS BRINGING SNOW TO THE METRO
AREA. SNOW WILL FALL HEAVY AT TIMES BETWEEN ABOUT 06-12Z TONIGHT.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE OF CEILINGS 5000 FEET OR LOWER AFTER 00Z THIS
EVENING.

* MODERATE CONFIDENCE OF VISIBILITIES AT OR BELOW 1/2 MILE IN SNOW
AFTER 06Z TONIGHT.

* MODERATE CONFIDENCE IN PRECIPITATION STARTING OFF AS FREEZING RAIN
OR SLEET AROUND 03Z BEFORE CHANGING TO SNOW AROUND 06Z.

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING...MIZ047-MIZ048-MIZ053...UNTIL 10 AM FRIDAY.

WINTER STORM WARNING...MIZ049-MIZ054-MIZ055-MIZ063...FROM 7 PM
THURSDAY TO NOON FRIDAY.

WINTER WEATHER ADVISORY...MIZ060-MIZ061-MIZ062-MIZ068-MIZ069-
MIZ070...FROM 7 PM THURSDAY TO NOON FRIDAY.

WINTER WEATHER ADVISORY...MIZ075-MIZ076-MIZ082-MIZ083...FROM 9 PM
THURSDAY TO NOON FRIDAY.

LAKE HURON...
GALE WARNING...SAGINAW BAY...FROM 1 AM FRIDAY TO 1 PM FRIDAY.

BRISK WIND ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
HURON...FROM 10 PM THURSDAY TO 10 PM FRIDAY.

WINTER STORM WARNING...NEARSHORE WATERS FROM PORT AUSTIN TO HARBOR
BEACH...FROM 7 PM THURSDAY TO NOON FRIDAY.

LAKE ST CLAIR...
BRISK WIND ADVISORY...FROM 10 AM FRIDAY TO 10 PM FRIDAY.

MI WATERS OF LAKE ERIE...
BRISK WIND ADVISORY...FROM 10 AM FRIDAY TO 10 PM FRIDAY.

SHORT TERM...MANN
LONG TERM....HLO
MARINE.......DRK
AVIATION.....DRK

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

AREA FORECAST DISCUSSION

NWS TWIN CITIES/CHANHASSEN MN

232 PM CST THU FEB 7 2013

.DISCUSSION...
THE MAIN FORECAST ISSUE IS OBVIOUSLY THE POTENTIAL FOR A
SIGNIFICANT WINTER STORM ACROSS THE AREA OVER THE SECOND HALF OF
THE WEEKEND. LATEST WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSES
SHOW THE FEATURE OF INTEREST MOVING INTO THE WEST COAST AT THE
CURRENT TIME. THE OTHER FEATURES OF INTEREST IN THE BIG PICTURE
ARE THE UPPER WAVE CURRENTLY MOVING THROUGH OUR AREA... WHICH IS
HELPING TO GENERATE A SWATH OF PCPN OFF TO OUR SOUTHEAST... AND
THE SOUTHERN STREAM WAVE MOVING ALONG THE GULF COAST. THESE TWO
UPPER WAVES WILL PHASE OFF THE MID-ATLANTIC COAST AND CREATE A
BLOCKBUSTER OF A WINTER STORM FOR FOLKS IN NEW ENGLAND OVER THE
NEXT 48 HOURS. THE EVOLUTION OF THAT SYSTEM WILL IMPACT HOW THE
WESTERN SHORTWAVE BEHAVES AS IT EJECTS NORTHEAST INTO OUR AREA
OVER THE LATTER HALF OF THE WEEKEND. THE DEGREE TO WHICH THE
EASTERN STORM BOTTLES UP THE FLOW WILL HELP DICTATE THE TRACK AND
AMPLITUDE OF THE UPPER PATTERN AHEAD OF OUR SYSTEM... WHICH IS
LIKELY PART OF WHY WE/RE STILL SEEING A SIGNIFICANT AMOUNT OF
SPREAD IN THE GUIDANCE AS TO HOW THINGS WILL UNFOLD ACROSS OUR
AREA. THE NAM AND GFS ARE FARTHEST WEST... ALONG WITH THE SREF...
WHILE THE ECMWF... GEM... AND FIM ARE FARTHER EAST. AT THIS
POINT... THE CONSENSUS OF THE GUIDANCE IS FAIRLY CLOSE TO THE
ECMWF EVOLUTION... SO WILL STICK SOMEWHAT CLOSE TO THAT WHILE
ALLOWING FOR A BIT MORE WARMING IN THE LOW LEVEL THERMAL PROFILES
IN ACCORDANCE WITH WHAT THE NAM AND GFS SUGGEST TO SOME EXTENT.
THIS WOULD CONTINUE TO SUGGEST A MIXED PCPN EVENT FOR A GOOD PART
OF THE AREA... WITH THE NORTH AND NORTHWEST PORTION OF THE AREA
HAVING THE GREATEST LIKELIHOOD OF REMAINING ALL SNOW. WITH THAT IN
MIND... WILL BE ISSUING A WINTER STORM WATCH THAT INCLUDES THE
NORTHERN AND WESTERN PORTION OF THE AREA FROM SATURDAY NIGHT
THROUGH SUNDAY NIGHT. IT IS POSSIBLE THAT THE WATCH MAY NEED TO BE
EXTENDED SOUTH/EAST IN AREA DEPENDING UPON HOW EXPECTATIONS
EVOLVE... BUT FOR NOW DECIDED TO FOCUS ON WHERE CONFIDENCE IS
HIGHEST THAT 6-8 INCHES OR MORE OF SNOW WILL OCCUR... ALONG WITH
STRONG WINDS.

IN THE SHORTER TERM... LINGERING VERY LIGHT FREEZING DRIZZLE
CURRENTLY ACROSS THE AREA SHOULD MIX WITH SOME SNOWFLAKES AS WE
SEE A BIT OF SEEDING FROM DEEPER MOISTURE ASSOCIATED WITH THE
UPPER WAVE MOVING ACROSS THE AREA... AND ALL OF THIS ACTIVITY
SHOULD EXIT QUICKLY TO THE EAST THIS EVENING AS WE GET ONTO THE
BACKSIDE OF THE WAVE AND SEE SOME SUBSIDENCE SPREAD OVER THE AREA.
HIGH PRESSURE WILL REIGN FRIDAY THROUGH FRIDAY NIGHT... ALLOWING
FOR FAIR AND DRY CONDITIONS. RETURN FLOW WILL SETUP BY SATURDAY
MORNING... THEN REMAIN IN PLACE INTO SATURDAY NIGHT... ALLOWING
FOR GOOD MOISTURE RETURN AHEAD OF THE SYSTEM WHICH WILL EXIT THE
ROCKIES SATURDAY EVENING AND MOVE NORTHEAST INTO NEBRASKA BY
SUNDAY MORNING. GOOD ISENTROPIC ASCENT IS PROGGED ALONG THE
EASTERN PERIPHERY OF THE INVERTED TROUGH AHEAD OF THE SURFACE
LOW... AND UPPER DIVERGENCE IS EXPECTED TO INCREASE DRAMATICALLY
ACROSS THE CWFA BY SUNDAY AFTERNOON AND THE UPPER FLOW AMPLIFIES
AND DIFFLUENCE INCREASES MARKEDLY IN THE LEFT EXIT REGION OF THE
APPROACHING JET. THESE THINGS SUPPORT DEVELOPMENT AND ENHANCEMENT
OF PCPN ACROSS THE AREA ON SUNDAY WITH THIS INITIAL SURGE OF WARM
ADVECTION AND DEEP MOISTURE INTO THE AREA. PCPN-TYPE CONTINUES TO
BE THE PRIMARY ISSUE THAT WILL MITIGATE SNOWFALL POTENTIAL... AND
THERE IS GOOD AGREEMENT THAT WE SHOULD SEE SUFFICIENT WARM AIR
MOVE IN ALOFT TO CHANGE THINGS TO SLEET AND PERHAPS SOME FREEZING
RAIN FOR A TIME ACROSS THE SOUTHERN PORTION OF THE AREA... BEFORE
GOING OVER TO MAINLY RAIN FOR AT LEAST PART OF THE DAY. HOWEVER...
HEIGHTS CRASH QUICKLY BY SUNDAY EVENING AS THE UPPER LOW MOVES
INTO THE AREA... WHICH ALONG WITH DYNAMIC COOLING FROM SUSTAINED
UPWARD MOTION COULD HELP TO CHANGE THINGS BACK TO SNOW FAIRLY
QUICKLY DEPENDING UPON WHETHER THE AMOUNT OF WARM AIR WHICH MOVES
IN IS AS ROBUST AS THE GFS SUGGESTS OR CLOSER TO THE ECMWF AND
FIM. FOR NOW... KEPT THINGS ALL SNOW ACROSS THE NORTH AND
NORTHWEST... AND ALLOWED FOR MIXED PCPN UP THROUGH THE SOUTHERN
COUNTIES AND INTO THE NORTHERN TWIN CITIES METRO. THAT BEING
SAID... WITH PCPN TOTALS OF OVER SIX TENTHS OF AN INCH EXPECTED
OVER MUCH OF THE AREA... AND PERHAPS SOME CLOSE TO AN INCH... ANY
PERIOD OF SNOW COULD PUT DOWN DECENT ACCUMULATIONS. EXPECT
LOCATIONS THAT REMAIN ALL SNOW TO WIND UP BETWEEN 6 AND 10 FOR THE
MOST PART... ALTHOUGH LOCALLY HIGHER AMOUNTS COULD OCCUR DEPENDING
ON RATIOS... WHILE AMOUNTS WILL DECREASE QUICKLY AS ONE MOVES INTO
AREAS WHERE A GREATER PORTION OF THE PCPN IS OF MIXED-TYPE AND/OR
RAIN. AT THIS POINT... THE BEST GUESS FOR THE TWIN CITIES WOULD BE
FOR TOTAL AMOUNTS OF NEAR 6 INCHES... WITH THE NORTH AND NORTHWEST
SUBURBS SEEING THE GREATEST... BUT THAT COULD CERTAINLY CHANGE
DEPENDING UPON HOW THE STORM TRACK PANS OUT AND THE CHARACTER OF
WARM ADVECTION AHEAD OF IT. NEEDLESS TO SAY... THE SITUATION WILL
REQUIRE CONTINUED MONITORING... WITH UPDATES AND CHANGES LIKELY AS
WE HEAD THROUGH THE NEXT DAY OR TWO.

SOME SNOW SHOWERS CAN BE EXPECTED IN THE CYCLONIC FLOW ON THE
BACKSIDE OF THE SYSTEM THROUGH THE DAY ON MONDAY... WITH THINGS
DRYING OUT FOR GOOD ONCE HIGH PRESSURE WORKS IN MONDAY NIGHT AND
TUESDAY. BENIGN WEATHER THEN LOOKS TO PREDOMINATE THROUGH THE
BALANCE OF THE FORECAST PERIOD. AN ALBERTA CLIPPER COULD IMPACT
THE AREA BY THURSDAY... ALTHOUGH THERE ARE SOME DEFINITE TIMING
AND PLACEMENT DIFFERENCES BETWEEN THE GFS... ECMWF... AND THEIR
RESPECTIVE ENSEMBLES WITH RESPECT TO THAT... SO KEPT THING DRY
AFTER MONDAY FOR NOW.

.AVIATION.../18Z TAF ISSUANCE/
/ISSUED 1211 PM CST THU FEB 7 2013/
AFTER ABOUT 6 STRAIGHT HOURS OF NEARLY SATURATED CONDITIONS...FZDZ
FINALLY MADE AN APPEARANCE AROUND 10 AM...WHICH WAS ACCOMPANIED BY
A BLOOM IN LOW REFLECTIVITIES ON RADAR. STILL SEEING THAT RADAR
BLOOM AT 18Z...BUT DZ HAS BEEN LIGHT...IT IS BARELY PERCEPTIBLE
AND IS OF MINIMUM IMPACT...SO LEFT MENTION OUT OF THESE TAFS. OF
BIGGER CONCERN FOR THE REST OF TONIGHT INTO TOMORROW IS THE SEA OF
STRATUS THAT IS IN PLACE FROM MICHIGAN BACK TO THE WRN DAKOTAS AND
NE NEB. GIVEN THE EXTENT OF STRATUS...WENT MORE PESSIMISTIC WITH
STRATUS THROUGH TONIGHT. CURRENT TREND ACROSS CENTRAL MN SHOWS
MVFR CIGS MAKING INROADS SOUTH...WITH MSP AND WI TERMINALS LIKELY
GOING MVFR BY 20Z...WITH A BIT OF A LONGER DELAY SOUTHWEST TOWARD
RWF. AS SFC RIDGING AND UPPER SUBSIDENCE MOVE OVERHEAD
TONIGHT...EXPECT CIGS TO RETREAT BACK TO IFR LEVELS...WITH
MVFR/IFR VSBYS RETURNING AS WELL. DO EXPECT SOME CLEARING TONIGHT
OVER NE MN CLOSER TO CENTER OF HIGH PRES...SO WILL HAVE TO WATCH
HOW FAR SW INTO CENTRAL MN THAT CAN MAKE IT TONIGHT. CONFIDENCE IN
TIMING OF IMPROVEMENTS FRIDAY MORNING NOT VERY HIGH...JUST WANTED
TO TREND CIGS REMAINING LONGER WITH THESE TAFS.

KMSP...GIVEN EXTENT OF STRATUS...CONFIDENT IN CIGS REMAINING IN
PLACE THROUGH THE EVENING PUSH...WITH HEIGHTS GOING BACK TO
BETWEEN 010 AND 017. CONFIDENCE STARTS TO DIMINISH OVERNIGHT WITH
POTENTIAL FOR SOME CLEARING WORKING SOUTH WITH THE RIDGE...BUT
WITH STRATUS IN PLACE...PLAYED THINGS THE PESSIMISTIC ROUTE FOR
NOW. ALSO BROUGHT BACK MVFR VIS...BUT CONFIDENCE NOT AS HIGH WITH
THAT. AT SOME POINT IN THE MORNING AS MSP GETS ON THE WEST SIDE OF
THE RIDGE...VFR CONDITIONS WILL RETURN ALONG WITH SOUTHEAST
WINDS...BIG QUESTION REMAINS WHEN.

/OUTLOOK FOR KMSP/
SAT...VFR. IFR DEVELOPING LATE WITH PRECIP MIX. WINDS SSE 10G15KTS.
SUN...IFR WITH RA/SN. SIGNIFICANT IMPACTS POSSIBLE. ESE AT 15G20KTS.
MON...IFR WITH SN IN MORNING...MVFR AFTERNOON. WINDS WNW 20G30KTS.

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH LATE SUNDAY
NIGHT FOR BENTON-CHIPPEWA-DOUGLAS-ISANTI-KANABEC-KANDIYOHI-
LAC QUI PARLE-MEEKER-MILLE LACS-MORRISON-POPE-SHERBURNE-
STEARNS-STEVENS-SWIFT-TODD-YELLOW MEDICINE.

WI...NONE.
&&

AREA FORECAST DISCUSSION...UPDATED

NWS ST LOUIS MO

905 PM CST FRI FEB 8 2013

.UPDATE...
ISSUED AT 838 PM CST FRI FEB 8 2013

PERSISTENT LOW LEVEL CLOUD COVER REMAINS ACROSS THE FORECAST AREA
WITH CLEARING W AND SW OF OUR AREA. ALSO HIGH LEVEL CLOUDS WERE
STREAMING EWD THROUGH MO AND INTO WRN IL. THE 12Z AND 18Z FRI
MODEL AND MOS GUIDANCE OFFERING NO HELP WITH CLOUD FORECAST TGT AS
THE GUIDANCE HAS MUCH OF THE LOW CLOUDS ALREADY OUT OF OUR AREA BY
NOW. WILL SLOW CLEARING OF CLOUDS FOR LATER TGT INTO SAT MRNG. AS
SFC RIDGE EXTENDING FROM WI S THROUGH IL SHIFTS EWD AND SFC WINDS
VEER AROUND TO A SLY DIRECTION SAT MRNG WE SHOULD FINALLY SEE LOW
LEVEL CLOUDS CLEAR OUT. WITH LOW LEVEL CLOUD CEILING ALONG WITH
WEAK LOW LEVEL WAA WILL ONLY SEE A SLOW FALL IN TEMPERATURES FOR
THE REST OF TGT.

GKS

.SHORT TERM...
ISSUED AT 235 PM CST FRI FEB 8 2013
(TONIGHT)

AT 20Z...NW UPPER LEVEL FLOW DOMINATES THE MID MS VALLEY THIS
AFTERNOON WITH A MODESTLY AMPLIFIED RIDGE AXIS OVER THE PLAINS. AT
THE SFC...RIDGE AXIS EXTENDS FROM WRN WI INTO NWRN MO. SAT PIX
SHOWS EXTENSIVE AREA OF LO ST/SC CLOUD...BUT IT HAS BEEN SHRINKING
AND BEEN DISPLAYING FISSURES THE PAST FEW HRS...MOST NOTABLY OVER
SWRN-WRN MO AND PARTS OF IL. LARGE AREA OF THINNER CI CLOUDS ARE
SEEN SPILLING OVER THE UPPER LEVEL RIDGE JUST TO THE W OF MO. THESE
CLOUDS HAVE KEPT TEMPS DOWN WITH MINIMAL DIURNAL RISES SINCE EARLY
THIS MORNING...WITH READINGS IN THE 30S.

MAIN FCST PROBLEM IS RATHER PERSISTENT LO CLOUDS...STILL A HANGOVER
FROM YESTERDAY/S WX SYSTEM. FROM PREVIOUS UPDATED DISCUSSION LATE
THIS MORNING...MAIN OPPORTUNITIES FOR CLEARING WILL PRESENT
THEMSELVES WITH ANY ADDITIONAL DISSIPATION THAT THE SUN CAN DO OVER
THE NEXT HOUR OR TWO...AS THAT WINDOW IS STARTING TO CLOSE...WITH
HELP FROM ANY LOCALIZED AREAS OF DOWNSLOPE AND WHERE SUBSIDENCE CAN
BE STRONG ENOUGH WHERE THE LO CLOUD DECK IS THIN ENOUGH. FROM THAT
POINT HEADING INTO THE NIGHT...ADVECTION WILL THEN TAKE OVER...AND
SO FCST CONFIDENCE WILL INCREASE DRAMATICALLY ON THIS ISSUE BY EARLY
THIS EVENING ONCE DISSIPATION POTENTIAL IS GONE AND IT BECOMES ALL
ADVECTIVE PROCESSES.

FOR NOW...LOOKS LIKE BEST POTENTIAL WILL BE IN CNTRL IL WHERE CLOUDS
ARE ABOUT 500-600FT THICK AND WHATEVER CAN EDGE TOWARDS CNTRL-SERN
MO FROM AREAS THAT HAVE ALREADY CLEARED OUT FROM PRIMARILY DOWNSLOPE
PROCESSES. OTHERWISE...ONCE ADVECTION BECOMES THE ONLY GAME IN
TOWN...WILL NEED TO WAIT OUT THE LO LEVEL RIDGE UNTIL FLOW TURNS OUT
OF THE S LATE TONIGHT AND SATURDAY MORNING. BOTTOM LINE...LOOKS TO
BE CLOUDY FOR MOST AREAS FOR MUCH OF THE NIGHT.

THE UPPER LEVEL RIDGE AXIS WILL SLIDE E ACROSS OUR REGION TONIGHT
AND ALLOW THE ABUNDANT...MOSTLY THIN...CI CLOUDS TO OVERSPREAD BY
DAYBREAK. TEMPS WILL HAVE LITTLE CHANCE TO PLUNGE DESPITE SFC RIDGE
AXIS LIKEWISE SLIDING ACROSS OUR REGION WITH CLOUD ISSUES...TRADING
ONE CEILING FOR ANOTHER...ALBEIT HIGHER...ONE. WHERE LO CLOUDS ARE
EXPECTED TO TAKE THE LONGEST TO CLEAR...HAVE WENT THE MOST ABOVE MOS
FOR MIN TEMPS. OTHERWISE...PREFERRED NEAR THE WARMER MOS GUIDANCE
SINCE IT TENDED TO GO TOO OPTIMISTIC ON CLOUD COVER AS A RULE.

TES

.LONG TERM...
ISSUED AT 253 PM CST FRI FEB 8 2013
(TOMORROW THROUGH NEXT THURSDAY)

WARM AND QUIET CONDITIONS ARE ANTICIPATED DURING THE DAY TOMORROW
WITH SELY WINDS AROUND THE BACK SIDE OF A SFC HIGH PRESSURE CENTER
AND RISING HEIGHTS ALOFT AHEAD OF AN APPROACHING LOW PRESSURE
SYSTEM. BUFKIT SOUNDINGS SHOW MIXING TO AROUND H92 WHICH SUPPORTS
AFTN HIGHS IN THE UPPER 40S TO LOWER 50S GIVEN H92 TEMPERATURES OF
2-5 DEGREES AND PLENTY OF INSOLATION.

A 40-50KT LLJ WILL TRANSPORT MOISTURE NWD ABOVE A WMFNT AS IT LIFTS
THROUGH AR INTO SRN MO ON SAT NIGHT. THESE PROCESSES WILL RESULT IN
PDS OF RAIN SHOWERS WITH EMBEDDED THUNDERSTORMS FROM LATE SAT NIGHT
THROUGH SUNDAY. THE PRESENCE OF THE RIDGE ACROSS THE CENTRAL PART OF
THE COUNTRY THROUGH TOMORROW WILL LIMIT THE AMOUNT OF MOISTURE
RETURN THAT OCCURS AHEAD OF THE EJECTING LOW PRESSURE SYSTEM.
ALTHOUGH THE DELAY IN MOISTURE RETURN WILL TEND TO LIMIT THE SEVERE
WEATHER POTENTIAL FOR OUR AREA...SOME OF THE EMBEDDED THUNDERSTORMS
COULD PRODUCE MODERATE RAINFALL AT TIMES DUE TO THE UNSEASONABLY
MOIST AIR MASS DEPICTED BY SREF/GFS/WRF FCSTS OF PW VALUES WHICH
RISE TO OVER 2 STDDEV ABOVE NORMAL FOR FEB IN THIS PART OF THE
COUNTRY. TEMPERATURES SHOULD BE AT LEAST AS WARM ON SUNDAY AS THEY
WERE ON SAT BECAUSE THE SFC WMFNT LIFTS THROUGH THE AREA DURING THE
MORNING AND BECAUSE IT LOOKS LIKE A DRY SLOT MOVES ACROSS THE AREA
DURING THE AFTN LEADING TO LESS CLOUD COVER AND MORE INSOLATION
ACROSS SOME PARTS OF THE CWA. A CDFNT WILL THEN SWEEP ACROSS THE
CWA DURING THE LATE AFTN AND EARLY EVENING HOURS. NO PCPN IS
EXPECTED BEHIND THE FRONT DUE TO STRONG ISENTROPIC DOWNGLIDE.

ANOTHER LOW PRESSURE SYSTEM DVLPS ACROSS THE SWRN CONUS IN THE WAKE
OF SUNDAYS SYSTEM. MODEL GUIDANCE SEEMS TO BE SETTLING ON A SRN
SOLUTION WITH THE TRACK OF THE VORT MAX REMAINING SOUTH OF THE CWA
ON TUE NIGHT AND WED. MODELS ALSO SHOW A COUPLE OF SHORTWAVES
CROSSING THE ROCKIES ON WED AND MOVING INTO THE PLAINS ON THU
HOWEVER THERE IS SOME DISAGREEMENT BETWEEN THE 12Z ECMWF/GFS ON THE
DEGREE OF INTERACTION BETWEEN SHORTWAVES AND ON HOW FAR SOUTH THEY
WILL DIG.

KANOFSKY

.AVIATION...
ISSUED AT 512 PM CST FRI FEB 8 2013

JUST AS I SUSPECTED LAST NIGHT...THE STRATUS DID NOT CLEAR TODAY.
IN FACT...IT MAY NOT CLEAR UNTIL SATURDAY MORNING...LOOKING AT THE
LATEST SATELLITE IMAGERY AND RUC 950MB MOISTURE FORECAST.
MEANWHILE...CIRRUS WILL CONTINUE TO SPREAD OVERHEAD FROM THE
PLAINS AS NEXT STORM SYSTEM DEVELOPS.

LIGHT WIND THIS EVENING WILL BECOME SOUTHEAST AND INCREASE ON SATURDAY.

SPECIFICS FOR KSTL...

MVFR STRATUS AROUND 2KFT WILL REMAIN OVER THE TERMINAL UNTIL LOW
LEVEL WINDS CAN TURN OUT OF THE SOUTH AND ADVECT IT AWAY. HAVE
POSTPONED CLEARING UNTIL 15Z. LIGHT WIND WILL BECOME SOUTHEAST
LATE TONIGHT AND INCREASE ON SATURDAY.

CVKING

.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 30 50 39 58 / 0 0 60 80
QUINCY 28 47 36 52 / 0 5 60 80
COLUMBIA 27 53 40 60 / 0 5 80 80
JEFFERSON CITY 27 54 41 61 / 0 5 80 80
SALEM 25 47 38 53 / 0 0 40 100
FARMINGTON 25 52 39 55 / 0 5 60 90

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

WFO LSX

AREA FORECAST DISCUSSION...UPDATED AVIATION

NWS ST LOUIS MO

517 PM CST FRI FEB 8 2013

.SHORT TERM...
ISSUED AT 235 PM CST FRI FEB 8 2013
(TONIGHT)

TES

.LONG TERM...
ISSUED AT 253 PM CST FRI FEB 8 2013
(TOMORROW THROUGH NEXT THURSDAY)

KANOFSKY

.AVIATION...
ISSUED AT 512 PM CST FRI FEB 8 2013

LIGHT WIND THIS EVENING WILL BECOME SOUTHEAST AND INCREASE ON SATURDAY.

SPECIFICS FOR KSTL...

CVKING

.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 30 50 39 58 / 0 0 60 80
QUINCY 28 47 36 52 / 0 5 60 80
COLUMBIA 27 53 40 60 / 0 5 80 80
JEFFERSON CITY 27 54 41 61 / 0 5 80 80
SALEM 26 47 38 53 / 0 0 40 100
FARMINGTON 25 52 39 55 / 0 5 60 90

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

WFO LSX

AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

303 PM CST Thu Feb 7 2013

.DISCUSSION...

Tonight through Saturday afternoon...

The main concern for tonight will be the extent and longevity of a
stratus shield which has been sinking southward this afternoon.
Local near-surface moisture from recent rainfall and a low-level
wind trajectory off the existing stratus will continue through at
least 09z, which may support its southward expansion. However, model
agreement is poor beyond 00z and some erosion has been evident along
the far western and southwestern edge this afternoon, so the
forecast remains uncertain. Hourly temperature trends and forecast
low temperatures tonight will need to be monitored, especially if
stratus clears quickly.

After clearing occurs Friday morning, clear skies and return flow
developing across the eastern Plains will allow temperatures to warm
for Friday and Saturday. Saturday afternoon may be a bit breezy as
deepening low pressure begins to eject out into the High Plains, but
any precipitation associated with the approaching system should hold
off until at least late Saturday afternoon or evening.

Saturday evening through Sunday night...

Warm air advection and moisture transport ahead of the deepening
system over the southern High Plains may allow showers and isolated
thunderstorms to develop by late Saturday afternoon. As a warm front
lifts through the CWA on Saturday night, thunderstorms will become
more likely and will spread northeastward across the region. A few
strong storms may be possible Saturday night; however, the limiting
factor will be the amount of moisture that can be transported into
the region between today`s and Saturday night`s systems. Models have
backed off a bit on low-level moisture increases during the night,
bringing 45 to possibly 50 degree dewpoints into the southeastern
CWA, but keeping the better moisture to the south and east. Have
also kept precipitation amounts on the conservative side as a result
of the moisture availability, although have trended higher that
blended model guidance products.

Thunderstorms will likely lose intensity on Sunday as the warm front
pushes through the region, while an intrusion of dry air works to
precipitation chances in advance of the cold front. A few breaks of
sunshine and strong warm air advection in the dry slot could help
central and southern portions of the CWA warm to near 60 on Sunday,
but this warming will depend on the amount of clearing that is
possible before the surface cold front pushes through. Rain chances
should end altogether by 00z Monday.

Monday through Thursday...

Quieter conditions are expected next week, with gradually warming
temperatures and little to no chance of precipitation. A system may
skirt the Gulf Coast on Monday night into Tuesday morning, but model
consensus keeps it far enough south not to impact any portion of the
forecast area. Ridging will briefly build over the central Plains by
Wednesday evening, allowing temperatures to rise back to above
normal values for middle to late next week, before colder conditions
become possible late Thursday.

Laflin

.AVIATION...

For the 18Z TAFs...back edge of light rain and low clouds is
currently clearing the KC area, and will make continued eastward
progress toward IRK and COU through the afternoon. Rapid improvement
to VFR is expected shortly after the rain ends.

Currently watching a very large area of MVFR/IFR cigs advancing
southeastward out of the Dakotas into eastern Nebraska. Most models
erode this cloud cover from west to east before it is able to impact
the KC terminals overnight. However, the RAP model, which has been
the better performer is similar scenarios this winter, brings thick
IFR clouds into all of the region overnight. Given all the remnant ground
moisture and falling temps overnight, and the extent of the cloud
cover on current satellite imagery, decided to go with the RAP with
widespread IFR restrictions tonight. If clouds do not develop then
areas of BR/FG will be a concern instead, especially along and north
of the STJ/IRK corridor.

Hawblitzel

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&

WFO EAX

AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

1138 AM CST Thu Feb 7 2013

...UPDATED AVIATION DISCUSSION...

.DISCUSSION...

Short Range (Today through Saturday)...`

Shortwave trough crossing the Continental Divide will track east
across KS/OK this morning and interact with a cold front that
currently stretches from central IA through the TX Panhandle. Modest
southerly low level jet plus generous theta-e advection has resulted
in precipitable water values well above seasonal values. Initial
overnight scattered convection affected areas north of the MO River
and has come and gone. However, an expanding area of showers and
isolated thunderstorms over central and eastern KS will overspread
much of the CWA this morning. Far northwest MO and northeast KS
could very well end up missing most of the rain today. Latest NAM
and RAP qpf have performed best overnight and look like they have
locked into the current radar trend.

The cold front will push southeast and through the CWA, reaching
central MO by mid afternoon. There will be some post frontal rain so
the passage of the front will not herald the end of the rain. That
should come several hours after passage of the front. Temperatures
will initially fall with the passage of the front but mid/late
afternoon clearing across the northwest third of the CWA should
allow a bit of a recovery in temperatures.

High pressure building into the region through Friday will bring
cooler temperatures but still end up being above normal. The high
pressure will head east of the CWA on Saturday as an upper level
ridge progresses east through the Central Plains and MO. The
resulting warm air advection will bring warmer temperatures plus an
increase in clouds. GFS and ECMWF have started to bring in the next
wave of precipitation a bit faster than earlier forecast and could
very well see scattered showers move into east central KS and far
west central MO late in the day. The initial wave of showers will
be elevated and won`t be surprised if the models continue trending
faster in bringing in the warm advection showers.

Medium Range (Saturday night through Thursday)...

There are two systems of concern in the medium range. The first is a
system that models agree will affect the entire forecast area
Saturday night into Sunday. The second system will move south of the
area Tuesday night bringing the chance for precipitation to the
extreme southern portion of the forecast area.

Models continue to be in good agreement that a closed upper low will
move out of the Great Basin on Saturday night and into the central
Plains. Surface cyclogenesis will also occur over eastern Colorado
Saturday night with a surface low developing and moving into central
Nebraska overnight. A cold front will stretch southward from the
surface low into the southern Plains. Strong warm air advection out
ahead of this front will spread Gulf moisture northward and showers
and thunderstorms will develop from west to east over the forecast
area. The upper level low and attendant surface low will move well
north of the area on Sunday into the Upper Midwest. The GFS is
slightly faster and a little further north than the EC but still in
good agreement. In any case, the local area will remain in the warm
sector and as the cold front moves through the area on Sunday and
showers and thunderstorms will continue to be likely over the
forecast area. Sunday night this system moves into the western Great
Lakes and the cold front pulls east of the forecast area.
Temperatures will be warm on Sunday ahead of the front with highs in
the 50s to near 60. Although there is no really cold air behind this
front, temperatures will be markedly cooler on Monday with highs in
the mid 30s to mid 40s.

The next system of interest will be a upper trough that digs down
the west coast on Monday and develops a closed low over the
southwestern CONUS on Tuesday. The GFS is further north with the
track of the closed low than the EC as it moves into the southern
Plains. The GFS would bring the upper low through Oklahoma and into
southern Missouri Tuesday night bringing snow to the southern half
of the forecast area. The EC would take the upper low across Texas
and into Arkansas leaving the forecast area dry. Opted to keep the
middle of the road solution offered by the initialization and keep
slight chance pops for light snow across the southern zones on
Tuesday night. Temperatures Tuesday will range into the mid 30s to
lower 40s. A warming trend with dry conditions will then be expected
through mid week with highs on Thursday in the 40s.

.AVIATION...

Hawblitzel

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&

WFO EAX

AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

547 AM CST THU FEB 7 2013

...UPDATED AVIATION DISCUSSION...

.DISCUSSION...

Short Range (Today through Saturday)...`

Medium Range (Saturday night through Thursday)...

.AVIATION...

For the 12Z TAFs...A large band of showers with MVFR
cigs/visibilities will affect west central MO this morning. The
heaviest rains with pockets of IFR cigs have a better chance to
affect KMKC and pass just south of KMCI. KSTJ will miss the heavier
showers. The rain should have moved east and out of KMCI/KMKC
terminals by around the noon hour.

A cold front will track southeast from northwest MO this morning
resulting in winds switching from the south to north and increasing
into the teens behind the front. Although upstream cigs behind the
front are VFR believe the rain cooled air will allow cigs to remain
in the MVFR category until the stronger northerly winds move in and
mix in drier air. The northerly winds will drop below 10kts by
around sunset with skies clearing.

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&

WFO EAX

AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

425 AM CST THU FEB 7 2013

.DISCUSSION...

Short Range (Today through Saturday)...`

Medium Range (Saturday night through Thursday)...

.AVIATION...

For the 06Z TAFs...Showers have begun to move into northwest
Missouri, ahead of a cold front that will settle through the region
Thursday. Initial onset of storms may be in the MVFR to VFR range,
with some thunderstorm activity, but conditions will deteriorate
during the early morning hours with ceilings and visibilities
dropping into the IFR range before sunrise for many hours. Expect
clearing at the terminals to begin around noon Thursday with north
winds prevailing. Conditions may improve to VFR before sunset, but
confidence in the timing of these out periods is low.

Cutter

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&

WFO EAX

AREA FORECAST DISCUSSION

NWS BILLINGS MT

958 AM MST THU FEB 7 2013

.SHORT TERM...VALID FOR TDY AND FRI...

A MINOR UPDATE WAS MADE TO THE CLOUD COVER FORECAST FOR TODAY SUCH
THAT AT LEAST PARTLY SUNNY WORDING IS ADVERTISED FOR MUCH OF SOUTH
CENTRAL AND PARTS OF SOUTHEASTERN MT. THIS CHANGE WAS BASED MAINLY
ON MID-MORNING SATELLITE IMAGES...WHICH SHOW INCREASING HIGH-LEVEL
CLOUDS OVER THE REGION. OTHERWISE...THE PRIMARY FORECAST CHALLENGE
TODAY WILL BE HIGH TEMPERATURES GIVEN WARM AIR ADVECTION ALOFT AND
RELATIVELY WEAK BOUNDARY LAYER FLOW AND MIXING. FORECAST SOUNDINGS
FROM THE 12 UTC NAM AND RAP SUGGEST MIXING WILL BE LIMITED TO NEAR
1000 FT AGL OVER MUCH OF THE AREA /SAVE FOR LIVINGSTON...WHERE THE
MIXING DEPTH IS SIMULATED A BIT DEEPER TO 2000 FT AGL/. WE BELIEVE
THIS WILL LIMIT HIGHS FROM REACHING THE FULL POTENTIAL OF THE WARM
AIR MASS. SINCE OUR FORECAST IS CLOSE TO THE BIAS-CORRECTED MULTI-
MODEL CONSENSUS...WE DECIDED TO LEAVE IT ALONE FOR NOW. SCHULTZ

.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...

A PACIFIC TROUGH CURRENTLY SEEN ON WV IMAGERY ENTERING THE PACIFIC
NORTHWEST WILL CUTOFF AND TRACK OVER THE GREAT BASIN BY SATURDAY
MORNING. THE EXTENDED FORECAST BEGINS HERE...WITH THE CUTOFF
PACIFIC LOW BRINGING COOLER WEATHER AND A PERIOD OF ACTIVE WEATHER
TO THE FORECAST AREA. CURRENT MODEL TRACKS OF THE LOW KEEP THE
BULK OF THE FORCING SOUTH OF THE FORECAST AREA...INTO WYOMING.
HOWEVER...THERE HAS BEEN A MINOR NORTHWARD TREND IN THE TRACK OF
THE LOW...WHICH GIVES OUR SOUTHERN ZONES A BETTER CHANCE OF SEEING
SOME PRECIPITATION ON SATURDAY WITH THIS SYSTEM. AS THE LOW SHIFTS
INTO THE DAKOTAS ON SUNDAY...NORTHERLY FLOW IS ESTABLISHED OVER
THE FORECAST AREA...AND A SECONDARY VORTICITY MAXIMUM IS ALLOWED
TO DIVE SOUTH ACROSS THE FORECAST AREA ON THE BACK SIDE OF THE
MEAN TROUGH. THIS SECONDARY VORT MAX WILL HELP TO PUSH A STRONGER
COLD FRONT ACROSS THE FORECAST AREA ON SUNDAY. THIS WILL GIVE THE
REST OF THE FORECAST AREA A BETTER CHANCE OF PRECIPITATION BEHIND
THE COLD FRONT.

MONDAY WILL REMAIN A COOLER DAY AS THE AMPLIFIED TROUGH IS SLOW TO
PUSH EAST...HOWEVER...THIS WILL ALSO BE A DRY DAY AS THE FORCING
WITH THE WAVE EXITS THE AREA. NORTHWESTERLY FLOW IS REESTABLISHED
ACROSS THE FORECAST AREA BY TUESDAY AS THE MEAN RIDGE AXIS SLOWLY
SLIDES EAST. DOWNSLOPE WINDS WILL RETURN TUESDAY AND
WEDNESDAY...BRINGING CONTINUED WARMING AND DRY CONDITIONS. EXPECT
ANOTHER WINDY PERIOD ALONG THE FRONT RANGE FROM LIVINGSTON TO BIG
TIMBER TO NYE. THE WINDS WILL HELP TO KEEP NIGHTTIME TEMPERATURES
MILDER IN THESE LOCATIONS...WITH DAY TIME HIGHES EXPECTED INTO THE
40S. ANOTHER PACIFIC TROUGH APPROACHES THE FORECAST AREA BY NEXT
THURSDAY...BRINGING THE NEXT BEST CHANCE OF COOLER TEMPERATURES
AND PRECIPITATION.

CHURCH

.AVIATION...

EXPECT VFR CONDITIONS THIS AFTERNOON THROUGH FRI MORNING.
LOCALIZED MOUNTAIN OBSCURATIONS WILL BE POSSIBLE OVER THE
CRAZYS...BEARTOOTHS AND ABSAROKAS LATE TONIGHT THROUGH FRI
MORNING. GUSTY SOUTHWEST SURFACE WINDS...WITH GUSTS TO 25 KT...WILL
OCCUR OVER KLVM THIS AFTERNOON AND EVENING. ARTHUR

.PRELIMINARY POINT TEMP/POPS...

TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 048 025/044 021/037 024/031 017/035 025/043 026/046
0/B 01/B 11/B 22/J 11/B 11/B 11/B
LVM 046 023/041 017/033 021/027 013/034 028/041 027/044
0/N 02/O 22/J 32/J 21/B 11/N 11/B
HDN 046 018/042 017/036 022/030 014/034 021/042 022/045
0/B 00/B 12/J 23/J 21/B 11/B 11/B
MLS 047 022/042 017/034 021/029 014/032 022/039 024/041
0/B 00/B 10/B 23/J 21/B 11/B 11/B
4BQ 049 023/044 020/034 020/029 015/030 021/039 023/042
0/U 00/B 11/B 23/J 21/B 11/U 11/B
BHK 044 019/042 013/031 017/027 011/026 018/034 021/036
0/U 00/B 00/B 23/J 20/B 01/B 11/B
SHR 044 019/041 017/032 016/027 011/029 016/039 018/042
0/U 00/B 53/J 34/J 21/B 11/B 11/B

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.

$$
WEATHER.GOV/BILLINGS

AREA FORECAST DISCUSSION...UPDATED

NWS NORTH PLATTE NE

512 PM CST FRI FEB 8 2013

.UPDATE...

.AVIATION...
THE RUC IS DEVELOPING STRATUS WITH IFR/MVFR CIGS FROM THE NORTH
AND EAST OVERNIGHT. BEST GUESS ON KVTN IS 15Z. SO MVFR IS EXPECTED
TO DEVELOP ALONG HIGHWAY 20 AND ALONG AND EAST OF HIGHWAY 183 LATE
TONIGHT OR EARLY SATURDAY AM.

A SECOND AREA OF MVFR CIGS SHOULD MOVE UP FROM THE SOUTH SATURDAY
AFTN AND ENCROACH ON KLBF AROUND 21Z.

.PREV DISCUSSION... /ISSUED 356 PM CST FRI FEB 8 2013/

SHORT TERM...(THIS EVENING THROUGH SATURDAY)
SOUTH WINDS WILL DIMINISH OVERNIGHT...THEN BECOME MORE SOUTHEAST
TO EAST SATURDAY AS SURFACE LOW PRESSURE STARTS TO DEVELOP ACROSS
EASTERN COLORADO. WILL CONTINUE THE SLIGHT AND LOW CHANCE POPS FOR
SHOWERS SATURDAY AFTERNOON...AND ALSO KEEP THE THUNDER MENTION
ACROSS EXTREME SOUTHWEST NEBRASKA AS MID LEVEL LAPSE RATES START
TO STEEPEN IN THAT AREA. GULF MOISTURE STREAMS NORTH INTO THE AREA
DURING THE AFTERNOON...AND AN INCREASE IN LOW STATUS CLOUDS FROM
THE SOUTH IS EXPECTED.

LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
FORECAST CHALLENGE CONTINUES TO BY SNOWFALL ACCUMULATIONS WITH
THE APPROACHING WINTER STORM SATURDAY NIGHT INTO SUNDAY. LIKE
YESTERDAY...ALBEIT...TO A SLIGHTLY LESSER DEGREE...THE MODEL
SOLUTIONS CONTINUE TO BE DIVERGENT IN THE TIMING AND TRACK OF THE
H5 LOW...AND SURFACE LOW WITH THE APPG WINTER SYSTEM. THE NAM
CONTINUES TO BE THE FASTEST AND FURTHEST NORTH OF THE
FORECASTS...THE ECMWF IS THE FURTHEST SOUTH AND THE GFS IS A
COMPROMISE IN THE MIDDLE. THE CANADIAN AND UKMET SHOW SOME LIMITED
SUPPORT FOR A GFS/ECMWF COMPROMISE AND THIS WAS UTILIZED THIS
MORNING. AS IT STANDS ATTM...THE HEAVIEST ACCUMULATIONS CONTINUE
TO BE ALONG AND NORTH OF A LINE FROM OGALLALA...STAPLETON...TO
O`NEILL...WHERE THE STRONGEST DEFORMATION AND MID LEVEL
FRONTOGENESIS SETS UP. SOUTH OF THIS LINE...WEAKER MID LEVEL
LIFT...WILL LIMIT ACCUMS TO 2 TO 5 INCHES. ONE WORD OF CAUTION
HERE...ALL OF THESE MODEL SOLUTIONS HAVE BEEN PERSISTENT WITH
THEIR STORM TRACKS OVER THE PAST COUPLE OF DAYS. IF SYSTEM DOES
TRACK FURTHER SOUTH AS ADVERTISED IN THE ECMWF...SNOW
ACCUMULATIONS WILL BE HEAVIER ALONG THE INTERSTATE CORRIDOR AND
SLIGHTLY LIGHTER ALONG THE SD/NEBR BORDER. HIGHER FORECAST
CONFIDENCE LIES WITH EXPECTED WINDS ON THE BACK SIDE OF THE
EXITING SYSTEM SUNDAY. SURFACE LOW PRESSURE DROPS TO AROUND 990
MB...WITH A VERY TIGHT SURFACE GRADIENT ACROSS ALL OF WESTERN AND
NORTH CENTRAL NEBRASKA. SUSTAINED WINDS OF 25 TO 35 MPH...WITH
GUSTS TO 50 MPH LOOK PROBABLE...AND WITH ANY ACCUMULATED
SNOW...WILL LEAD TO CONSIDERABLE BLOWING AND DRIFTING SNOW.
DECIDED TO UPGRADE THE WINTER STORM WATCH TO A BLIZZARD WATCH
EARLIER...GIVEN THE EXPECTED WINDS LATE SATURDAY NIGHT AND SUNDAY
EVENING. PLACED THE REMAINDER OF THE FORECAST AREA MINUS
CHASE...HAYES AND FRONTIER COUNTIES IN A WINTER STORM WATCH...TO
ACCOUNT FOR WINDS...EVEN THOUGH EXPECTED ACCUMS ARE ON THE ORDER
OF 2 TO 5 INCHES. AS MENTIONED ABOVE...WILL UTILIZE WATCH
HEADLINES FOR NOW...AS THE LOCATION OF THE HEAVIEST SNOW...IS
STILL NOT DEFINED JUST YET.

IN ADVANCE OF THE SYSTEM...STRONG SOUTHERLY WINDS WILL CONTINUE INTO
SATURDAY AFTERNOON...ALLOWING LOW LEVEL MOISTURE TO PUSH INTO
SOUTHWESTERN AND CENTRAL NEBRASKA. MID LEVEL LAPSE RATES WILL
STEEPEN SATURDAY AFTERNOON AND EVENING...LEADING TO DECENT MID LEVEL
INSTABILITY ACROSS SOUTHWESTERN AND CENTRAL NEBRASKA. AS THE UPPER
LEVEL LOW PUSHES INTO NWRN KS SATURDAY EVENING...LEAD SHOWERS AND
EVEN AN EMBEDDED THUNDERSTORM WILL BE POSSIBLE. AT THIS TIME...NO
SEVERE THUNDERSTORMS ARE EXPECTED...HOWEVER...I WOULDN`T BE SURPRISED
IF SOME GRAUPEL OR PEA SIZED HAIL OCCURS...GIVEN THE LOW FREEZING
LEVELS. ALSO...SOME MID LEVEL INSTABILITY EXTENDS NORTH INTO NORTH
CENTRAL NEBRASKA SATURDAY NIGHT...WHICH MAY FACILITATE POSSIBLE
THUNDER SNOW.

EXTENDED RANGE CONTINUES WITH A BROAD LONGWAVE TROUGH FIRMLY IN
PLACE OVER THE EASTERN TWO-THIRDS OF THE CONUS...WITH NORTHWEST FLOW
OVER THE FORECAST AREA. THIS WILL HELP LIMIT TEMPERATURES TO NEAR OR
JUST BELOW NORMAL. ONLY PRECIP CONCERN COMES WEDNESDAY NIGHT AND
THURSDAY AS A SHORTWAVE EMBEDDED IN THE NORTHWEST FLOW DIVES
SOUTHEAST OUT OF CANADA. THIS WILL BRING A SLIGHT CHANCE OF LIGHT
SNOW TO THE NORTHERN HALF OF THE CWA AND ALSO BRING ANOTHER SHOT OF
COOLER TEMPS TO THE AREA TO END THE WEEK.

AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
FR CONDITIONS SHOULD PREVAIL ACROSS WESTERN AND NORTH
CENTRAL NEBRASKA FOR THE NEXT 24 HRS. OTHERWISE AN INCREASE IN
HIGH CIRRUS CLOUDS CAN BE EXPECTED...ALONG WITH GUSTY SOUTH SFC
WINDS TO 30 KTS TODAY. WINDS WILL DIMINISH SOME
TONIGHT...GENERALLY SOUTH TO SOUTHEAST 10 TO 15 KTS.

.LBF WATCHES/WARNINGS/ADVISORIES...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
FOR NEZ028-029-038-058-059.

BLIZZARD WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING FOR
NEZ004>010-022>027-035>037-056-057-094.

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

AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

1138 AM CST THU FEB 7 2013

.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.

EXTENSIVE STRATUS DECK...WITH SOME VISIBILITY RESTRICTIONS...WILL
CONTINUE TO SPREAD OVER THE TAF SITES THROUGH THE DAY AND
POSSIBLY INTO THE OVERNIGHT. WILL CONTINUE WITH IFR CONDITIONS FOR
THE TAF CYCLE. KLNK MAY BE THE ONLY EXCEPTION AS THEY REMAIN ON
THE EDGE OF THE STRATUS DECK.

KERN

.PREV DISCUSSION... /ISSUED 355 AM CST THU FEB 7 2013/

DISCUSSION...
CHALLENGING FORECAST TODAY WITH STRATUS SPREADING SOUTH AND
CAUSING POTENTIAL PROBLEMS WITH TEMPERATURE FORECAST...AND
CHALLENGING PRECIPITATION FORECAST FOR WEEKEND WITH STRONG LOW
MOVING THROUGH PLAINS.

CURRENT PATTERN AT THE SURFACE CONSISTED OF A WEAK COLD FRONT
THAT WAS ANALYZED AT 09Z ALMOST THROUGH THE SOUTHEAST CORNER OF
THE FORECAST AREA. WELL BEHIND THE FRONT IN SOUTH DAKOTA WAS AN
EXTENSIVE AREA OF LOW STRATUS...MOVING SOUTH AT AROUND 15 KNOTS.
SHORT TERM MODELS SHOW LITTLE AGREEMENT ON THE EVOLUTION OF THIS
AREA OF STRATUS. GENERALLY THE NAM AND GFS BRING IT INTO THE
FORECAST AREA BUT SUGGEST IT WILL ERODE BY AFTERNOON. HOWEVER THE
HIGHER RESOLUTION HRRR AND RAP ARE MUCH MORE PESSIMISTIC AND PUSH
THE STRATUS AS FAR SOUTH AS THE PLATTE RIVER BY 17Z AND SHOW IT
REMAINING. THIS OF COURSE HAS BIG IMPLICATIONS FOR THE TEMPERATURE
FORECAST. AT THIS TIME WE ARE MORE COMFORTABLE WITH A SOLUTION
CLOSER TO THE HRRR/RAP ESPECIALLY IN NORTHEAST NEBRASKA. THUS HAVE
LOWERED HIGH TEMPERATURES IN NORTHEAST NEBRASKA AND AND KEPT
CLOUDY WORDING THROUGH MUCH OF THE DAY.

TEMPERATURE/CLOUD UNCERTAINTY IS GREATEST FOR LOCATIONS ALONG
INTERSTATE 80 WHERE THE HRRR/RAP SHOW THE STRATUS JUST
APPROACHING. THIS AREA WILL NEED TO BE WATCHED THIS MORNING TO
MONITOR THE SOUTHWARD EXTENT OF THE CLOUD DECK AND THE NEW RUNS OF
THE HRRR AND RAP.

ON FRIDAY THE ATTENTION TURNS TO THE UPPER PATTERN PROGRESSING WITH
A STRONG UPPER LOW MOVING FROM THE WEST THROUGH THE ROCKIES AND
TAKING AIM ON THE PLAINS FOR THE WEEKEND. MODELS AGREE ON LEE SIDE
CYCLOGENESIS BY FRIDAY AFTERNOON AND SOUTH WINDS INCREASING BY
FRIDAY NIGHT. FRIDAY WILL BE DRY...WITH TEMPERATURES MILD AGAIN.

MOST MODELS SHOW DECENT AGREEMENT WITH THE UPPER LOW MOVING OUT OF
COLORADO SATURDAY NIGHT. SOUTHERLY 850 WINDS ARE PROGGED AS HIGH
AS 60 KNOTS OVER THE FORECAST AREA SATURDAY NIGHT AND SUNDAY
MORNING. LOW TEMPERATURES SATURDAY NIGHT WILL BE MILD...WITH
HUMIDITY INCREASING. VERTICAL MOTION AND MOISTURE WILL BE
SUFFICIENT TO TRIGGER SCATTERED SHOWERS ESPECIALLY NORTHERN HALF
OF FORECAST AREA. ON SUNDAY MORNING...THE DRY SLOT WILL BE PUSHING
NORTH THROUGH NEBRASKA. THIS PATTERN HAS THE APPEARANCE OF A
SPRING LOW TOPPED/COLD CORE THUNDERSTORM EVENT. TIGHTLY WRAPPED UP
SURFACE LOW IS PROGGED TO MOVE NEAR EASTERN NEBRASKA JUST EAST OF
CLOSED UPPER LOW...WITH MUCAPE VALUES OF 200-400 J/KG ALONG THE
EDGE OF THE DRY SLOT. CURRENTLY HAVE THUNDER MENTIONED IN FORECAST
AND WILL NEED TO MONITOR FOR ADDITIONAL DETAILS.

AS THE LOW MOVES NORTHEAST...COLD AIR MOVES IN WITH PRECIPITATION
CHANGING TO SNOW ESPECIALLY IN NORTHEAST NEBRASKA. SOME SCENARIOS
SUGGEST A FEW INCHES OF SNOW WITH NORTHWEST WINDS GUSTING TO 40
MPH GIVEN THE NORTHWEST 850 WINDS OF 50 KNOTS OVER FAR NORTHEAST
NEBRASKA. FORECAST COVERS THIS BUT WILL CONTINUE TO ADVERTISE THIS
POSSIBLE WINTER WEATHER EVENT IN HWO. MOST MODELS HAVE THE
PRECIPITATION ON SUNDAY ENDING AS THE LOW RAPIDLY MOVES
NORTHEAST...MEANING THE OMAHA-LINCOLN AREAS AND POINTS SOUTH WOULD
SEE LITTLE SNOW.

NIETFELD

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

518 AM CST THU FEB 7 2013

.AVIATION...

12Z TAFS FOR KOMA...KLNK...KOFK.

PRIMARY AVIATION CONCERNS TODAY ARE COVERAGE OF LOW CLOUDS AND
POSSIBLE VISIBILITY RESTRICTIONS. NORTHERLY LOW LEVEL WINDS WILL
OCCUR TODAY. THESE WILL HELP PULL STRATUS CURRENTLY OVER THE
DAKOTAS AND MINNESOTA DOWN INTO OUR AREA. RECENT RUNS OF THE HRRR
AND RAP SEEM TO HAVE A DECENT HANDLE ON THINGS.

DID NOT WANT TO BE TOO PESSIMISTIC WITH LOW CLOUDS FOR THIS AFTN
AT KOMA AND KLNK SINCE MODELS SUGGEST SOME THINNING OF THE LOW
LEVEL MOIST LAYER. IT APPEARS LOW CLOUDS MAY LINGER AT LEAST INTO
THE EVENING AT KOFK.

MILLER

.PREV DISCUSSION... /ISSUED 355 AM CST THU FEB 7 2013/

NIETFELD

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

355 AM CST THU FEB 7 2013

.DISCUSSION...
CHALLENGING FORECAST TODAY WITH STRATUS SPREADING SOUTH AND
CAUSING POTENTIAL PROBLEMS WITH TEMPERATURE FORECAST... AND
CHALLENGING PRECIPITATION FORECAST FOR WEEKEND WITH STRONG LOW
MOVING THROUGH PLAINS.

NIETFELD

.AVIATION...
06Z TAFS FOR KOMA...KOFK...KLNK

SURFACE COLD FRONT HAS MOVED THROUGH OFK...AND WILL SOON MOVE
THROUGH OMA/LNK BY 07Z. THE SHOWERS HAVE DEVELOPED THIS
EVENING...BUT SOUTH OF THE TAF SITES AND THUS HAVE A DRY 24 HR
PERIOD IN THE TAFS CURRENTLY. CURRENTLY MID LEVEL CLOUDS AT OMA/LNK
WILL SHIFT SWD OVER THE NEXT FEW HOURS LEAVING JUST SOME HIGH LEVEL
CLOUDS UNTIL MORNING. IR IMAGERY INDICATES THAT STRATUS IS DIVING
SWD THROUGH ERN SD AND THIS SHOULD BE INTO OFK AROUND 12Z AND OMA
AROUND 14-15Z. THERE IS SOME QUESTION IF THIS WILL MAKE LNK AND WILL
JUST INCLUDE A TEMPO ATTM. THE STRATUS DECK...IN THE MVFR
RANGE...WILL LINGER AT OMA/OFK THROUGH EARLY-MID AFTN. WE WILL ALSO
SEE WINDS INCREASE THROUGH THE MORNING AT ALL SITES WITH SOME GUSTS
LIKELY. THE WINDS AND CLOUDS WILL DIMINISH BY LATE AFTN.

BOUSTEAD

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

AREA FORECAST DISCUSSION

NWS HASTINGS NE

1059 PM CST WED FEB 6 2013

.AVIATION...06Z KGRI TAF. A COLD FRONT HAS PASSED THROUGH KGRI
AND THE WIND WILL NOW BE NORTHERLY THROUGHOUT THE DAY ON THURSDAY.
EXPECT THE THE NORTH WIND WILL INCREASE BY MID MORNING BECOMING
BREEZY AT TIMES THROUGH MID AFTERNOON. CLOUDS WILL ALSO ACCOMPANY
THE COLD FRONT WITH CLOUDY TO MOSTLY CLOUDY SKIES THROUGH MUCH OF
THE NIGHT UNTIL AROUND MID MORNING. HOWEVER...ANY CLOUDS APPEAR TO
BE WITHIN THE VFR CATEGORY. CLOUDS SHOULD CLEAR OUT BY LATER THIS
MORNING WITH CLEAR TO MOSTLY CLEAR SKIES EXPECTED BY AFTERNOON.

.PREV DISCUSSION... /ISSUED 1017 PM CST WED FEB 6 2013/

UPDATE...FOG HAS FORMED WHERE MOISTURE HAS POOLED JUST AHEAD OF
THE COLD FRONT AND WHERE THE WIND IS LIGHT. THIS FOG HAS BEEN
LOCALLY DENSE BUT ALSO FAIRLY SHALLOW. THE FOG WILL QUICKLY ERODE
AWAY FROM NORTHWEST TO SOUTHEAST ACROSS OUR FORECAST AREA AS THE
COLD FRONT SWEEPS THROUGH AND KICKS UP THE NORTH WIND. WILL
CONTINUE TO BE CALLING FOR DRY WEATHER ACROSS MOST OF OUR CWA
TONIGHT...AND HAVE EVEN REDUCED THE LOW POPS WE DID HAVE ACROSS
OUR FAR SOUTHEAST CWA AS LATEST 00Z RUC AND NAM MODEL RUNS KEEP
ALL THE THUNDERSTORMS SOUTHEAST OF OUR FORECAST AREA TONIGHT.
THEREFORE...HAVE ALSO PULLED THUNDER OUT OF THE FORECAST AND HWO
FOR OUR CWA...ALTHOUGH THE STORMS MAY NOT BE TOO FAR AWAY ONCE THEY
DEVELOP ON THE LOW LEVEL JET LATER TONIGHT JUST TO THE SOUTH OF
OUR CWA.

PREV DISCUSSION... /ISSUED 413 PM CST WED FEB 6 2013/

SHORT TERM...THROUGH THURSDAY AFTERNOON. MORNING UPPER AIR ANALYSIS
INDICATES A LONGWAVE TROUGH OVER THE NORTHEASTERN CONUS...WITH
QUASI-ZONAL FLOW OVER THE REMAINDER OF THE CONUS. MID AND UPPER
TROPOSPHERIC JET ENERGY EXTENDS FROM SOUTH CENTRAL
CANADA...SOUTHEAST INTO THE GREAT LAKES REGION AND THEN
EAST/NORTHEAST INTO EASTERN CANADA. TROPOSPHERIC FLOW OVER OUR
AREA IS NOT OVERLY STRONG...MAXING OUT AT AROUND 65KTS NEAR 200MB
PER 12Z SOUNDING DATA FROM KLBF. WATER VAPOR IMAGERY INDICATES A
MID LEVEL SHORT WAVE OVER THE SOUTHERN PLAINS...WITH ANOTHER SHORT
WAVE ADVANCING EAST ACROSS THE NORTHERN AND CENTRAL ROCKY MOUNTAIN
RANGE. AT THE SURFACE AN AREA OF LOW BAROMETRIC PRESSURE EXISTS
OVER SOUTHEASTERN COLORADO...WITH A STATIONARY BOUNDARY EXTENDING
NORTHEAST FROM THE LOW ACROSS PORTIONS OF NORTHEASTERN COLORADO
AND WESTERN NEBRASKA. OUR CWA STILL REMAINS AHEAD OF THE LOW LEVEL
BAROCLINIC ZONE AND AS A RESULT...THE LOW LEVEL WIND FIELD ACROSS
OUR AREA REMAINS FROM THE SOUTH/SOUTHWEST.

GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN ALL
SUGGEST THE MID LEVEL SHORT WAVE...CURRENTLY OVER THE NORTHERN AND
CENTRAL ROCKY MOUNTAIN RANGE...WILL CONTINUE MOVING EAST ACROSS THE
NORTHERN AND CENTRAL PLAINS THROUGH THE NEXT 24 HOURS. OMEGA AHEAD
OF THE MID LEVEL TROUGH AXIS DOES NOT LOOK ALL THAT IMPRESSIVE. THAT
BEING SAID...WHAT OMEGA WILL BE IN PLACE TONIGHT...WORKING IN
CONCERT WITH MODEST LOW LEVEL CONVERGENCE NEAR THE BAROCLINIC
ZONE...MAY PROVIDE ENOUGH LIFT FOR PRECIPITATION PRODUCTION ACROSS
SOUTHERN AND EASTERN PORTIONS OF OUR CWA TONIGHT...A SOLUTION
SUPPORTED BY QPF FIELDS FROM THE NAM...OPERATIONAL GFS...EC...AND
SREF-MEAN. WENT AHEAD AND MAINTAINED SLIGHT CHANCE TO CHANCE POPS
ACROSS OUR SOUTH AND EAST FOR TONIGHT AS A RESULT. FORECAST
PROXIMITY SOUNDINGS FROM ACROSS THE CWA...PER THE NAM AND
OPERATIONAL GFS...SUGGEST THE LOWER TROPOSPHERE SHOULD REMAIN WARM
ENOUGH FOR RAIN THROUGH THE OVERNIGHT HOURS. IN ADDITION TO THE
CHANCE FOR PRECIPITATION...THE NAM...OPERATIONAL GFS...AND EC ALL
SUGGEST DEEP LAYER MUCAPE VALUES BETWEEN 50 AND 100J/KG WILL BE
REALIZED ACROSS OUR EXTREME SOUTHEAST BY 06Z TONIGHT. GIVEN
THIS...WENT AHEAD AND INCLUDED ISOLATED THUNDER MENTION IN THE
GRIDS FOR TONIGHT...PRIMARILY FOR LOCATIONS SOUTHEAST OF A LINE
FROM OSBORNE TO HEBRON. THE LOW LEVEL BAROCLINIC ZONE IS EXPECTED
TO CLEAR OUR ENTIRE CWA BY 09Z TONIGHT...WITH THE MID LEVEL TROUGH
AXIS EXPECTED TO CLEAR OUR AREA BY LATE MORNING THURSDAY. WITH THE
PRIMARY AXIS OF OMEGA PUSHING EAST OF OUR AREA DURING THE DAY
THURSDAY...DRY CONDITIONS LOOK TO OVERTAKE OUR AREA HEADING INTO
THURSDAY.

OVERNIGHT LOWS GENERALLY IN THE 30S ARE EXPECTED ACROSS THE AREA
TONIGHT. WITH LOW LEVEL COLD AIR ADVECTION INFILTRATING THE AREA
TONIGHT BEHIND THE BAROCLINIC ZONE...SLIGHTLY COOLER WEATHER SHOULD
BE OBSERVED THURSDAY WHEN COMPARED TODAY...WITH HIGHS IN THE UPPER
40S TO LOWER 50S CURRENTLY FORECAST FOR MOST LOCATIONS ACROSS THE CWA.

LONG TERM...THURSDAY EVENING THROUGH NEXT WEDNESDAY. CLEARLY THE
MAIN FOCUS REMAINS THE 72-HOUR BLOCK OF TIME BETWEEN FRIDAY AND
SUNDAY NIGHT...INVOLVING THE APPROACH AND PASSAGE OF A STRONG LOW
PRESSURE SYSTEM...AND A VARIETY OF WEATHER ELEMENTS INCLUDING
POTENTIALLY ADVISORY-CRITERIA WINDS BOTH AHEAD OF AND BEHIND THE
MAIN SURFACE LOW...GENERALLY WEAK THUNDERSTORM ACTIVITY MAINLY
SATURDAY NIGHT....AND THEN THE CHANGEOVER TO SNOW/BLOWING SNOW
SOMETIME BETWEEN LATE SATURDAY NIGHT AND SUNDAY BEFORE ALL PRECIP
PULLS OUT OF THE AREA BY SUNDAY EVENING. ALTHOUGH THE LATEST 12Z
MODEL RUNS ARE STARTING TO ADD A BIT MORE CONFIDENCE THAT THE
BRUNT OF THE SNOW WILL JUST MISS OUR CWA TO THE NORTHWEST...THERE
COULD STILL BE PLENTY OF ISSUES ESPECIALLY IN OUR NORTHWEST
COUNTIES...NOT TO MENTION THAT STILL BEING 4 DAYS AWAY CHANGES IN
THE TRACK OF THE SYSTEM ARE STILL POSSIBLE.

STARTING OUT WITH THURSDAY EVENING THROUGH FRIDAY
NIGHT...CONFIDENCE REMAINS HIGH IN DRY WEATHER...AS FLOW ALOFT
GRADUALLY TRANSITIONS FROM WEST-NORTHWEST BEHIND THE SHORTWAVE
DEPARTING ACROSS IA/IL/IN...TO SOUTHWEST FLOW AHEAD OF THE
LARGER...DEEPER TROUGH ORGANIZING OVER THE SOUTHWEST CONUS. ON
THURSDAY NIGHT...LIGHT BREEZES WILL GRADUALLY TRANSITION FROM
EASTERLY TO SOUTHERLY UNDER MOSTLY CLEAR SKIES. LOW TEMPS WERE
LOWERED A FEW DEGREES FROM PREVIOUS FORECAST...BUT STILL REMAINING
A FEW DEGREES ABOVE MET/MAV GUIDANCE BLEND...RESULTING IN MID 20S
MOST AREAS. FRIDAY...SKIES REMAIN MOSTLY SUNNY OVERALL...BUT
SOUTH-SOUTHEAST WINDS WILL BE ON THE INCREASE IN RESPONSE TO HIGH
PLAINS PRESSURE FALLS AND GOOD MIXING. UPPED WINDS A FEW MPH FROM
PREVIOUS FORECAST...WITH SUSTAINED SPEEDS 20-25 MPH IN MOST
AREAS...AND MORE SO 25-30 MPH IN OUR FAR WESTERN AREAS FROM DAWSON
THROUGH FURNAS COUNTIES. AT LEAST FOR NOW...THESE SPEEDS REMAIN
SLIGHTLY BELOW ADVISORY CRITERIA BUT IT BEARS WATCHING. NUDGED DOWN
HIGH TEMPS VERY SLIGHTLY DOWNWARD...RANGING FROM RIGHT AROUND 50
IN EASTERN ZONES...TO MID 50S SOUTHWEST. FRIDAY NIGHT...IT
REMAINS DRY AS THE PRIMARY MID LEVEL LOW CIRCULATION OVER THE
WESTERN CONUS EDGES NO CLOSER THAN THE UT/AZ/SOUTHWEST WY
AREA...BUT STEADY SOUTHERLY BREEZES WILL CONTINUE...LIKELY
RESULTING IN A RATHER MILD NIGHT. KEPT LOWS SIMILAR TO PREVIOUS
FORECAST WITH MOST AREAS HOLDING UP IN THE 32-36 RANGE...AND EVEN
THIS MIGHT NOT BE MILD ENOUGH GIVEN RECENT OVERNIGHT TRENDS.

FOCUSING NOW ON THE SATURDAY THROUGH SUNDAY NIGHT TIME FRAME...12Z
RUNS OF THE ECMWF/GFS/CANADIAN GEM ARE IN MUCH BETTER OVERALL
AGREEMENT THAN 24 HOURS AGO IN THE TRACK OF THE CLOSED 500MB
CIRCULATION...ALTHOUGH SOME SLIGHT TIMING DIFFERENCES DO EXIST.
GENERALLY SPEAKING...BY LATE SATURDAY AFTERNOON THE PRIMARY/STRONG
AND NEARLY VERTICALLY STACKED LOW PRESSURE CENTER WILL BE IN
EASTERN COLORADO...THEN REACHING THE HEART OF SOUTH CENTRAL NEB BY
SUNRISE SUNDAY MORNING...AND THEN THE WESTERN IA/POSSIBLY
SOUTHWEST MN AREA BY SUNDAY EVENING. GIVEN THAT THE SURFACE LOW IS
PROGGED TO TRACK ACROSS THE HEART OF THE CWA FROM SOUTHWEST-
NORTHEAST DURING THIS TIME...THE MOST INTENSE MID LEVEL
CONVERGENCE/DEFORMATION FOR HEAVY SNOW NOW LOOKS TO FOCUS JUST TO
OUR NORTHWEST ACROSS THE NEBRASKA SANDHILLS OF THE WFO LBF CWA.
HOWEVER...UNLESS THIS TRACK SHIFTS EVEN FARTHER NORTH...WE ARE
STILL PRONE TO SOME IMPACTS. BACKING UP TO SATURDAY DAYTIME...HAVE
INCREASING CONFIDENCE THAT THE MORNING HOURS WILL BE DRY...AND
HAVE PULLED PRECIP MENTION BEFORE NOON...WITH ONLY SLIGHT CHANCES
FOR RAIN SHOWERS IN THE AFTERNOON AS LOW LEVEL MOISTURE ADVECTION
GETS GOING. OVERALL THOUGH...WOULD NOT BE SURPRISED IF THE
MAJORITY OF THE CWA MAKES IT THROUGH THE DAY WITHOUT SEEING MORE
THAN SPRINKLES. AS FOR TEMPS...SHOULD STILL BE MILD WITH HIGHS
AROUND 50 NEARLY ALL AREAS...UNLESS LOW CLOUDS MOVE IN QUICKLY
ENOUGH TO HOLD THINGS DOWN A BIT. SOUTH-SOUTHEAST WINDS WILL ALSO
REMAIN FAIRLY STRONG ON SATURDAY...AND COULD POSSIBLY AGAIN FLIRT
WITH ADVISORY CRITERIA ALTHOUGH CURRENT FORECAST ONLY HAS
SUSTAINED SPEEDS TOPPING OUT 20-25 MPH. FOR SATURDAY NIGHT...THE
BIGGEST CHANGES FROM PREVIOUS FORECAST WERE TO INTRODUCE A SLIGHT
CHANCE OF THUNDERSTORMS ALONG WITH FAIRLY WIDESPREAD RAIN
SHOWERS...AND ALSO TO CONFINE ANY SNOW POTENTIAL TO ONLY THE FAR
WESTERN SOUTH CENTRAL NEBRASKA COUNTIES WELL AFTER MIDNIGHT.
CERTAINLY FOR THE VAST MAJORITY OF THE CWA...PRECIP TYPE IS NOW
EXPECTED TO REMAIN RAIN THROUGH THE NIGHT...WITH SOME AREAS
POSSIBLY SEEING A FEW TENTHS OF INCH AND LOCALLY HIGHER. ALTHOUGH
AT LEAST A FEW WEAK THUNDERSTORMS ARE A GOOD BET GIVEN WEAK
ELEVATED INSTABILITY AND THE STRENGTH OF THE UPPER WAVE...NOT
EXPECTING ANYTHING ALL THAT STRONG ALTHOUGH SUPPOSE IT WOULDN/T
TAKE MUCH TO GET PEA SIZE HAIL. SUNDAY DAYTIME...A STRONG COLD
FRONT SWEEPS ACROSS THE CWA AS THE LOW PASSES EAST...CHANGING ANY
RAIN TO SNOW...AND ALTHOUGH NOT EXPLICITLY REFLECTED IN THE OFFICIAL
GRIDS YET...SUSTAINED SPEED OF 30+ MPH ARE VERY MUCH POSSIBLE
GIVEN THE STRENGTH OF THE LOW LEVEL PRESSURE GRADIENT. WHILE POPS
WERE REDUCED DURING THE DAY ACROSS SOUTHERN ZONES AS THE MID LEVEL
DRY SLOT DOMINATES THIS AREA...NORTHWEST ZONES ESPECIALLY
NORTHWEST OF A BEAVER CITY-GRAND ISLAND-FULLERTON LINE ARE STILL
IN LINE TO POSSIBLY RECEIVE 2+ INCHES OF WIND-BLOWN SNOW. EVEN
ASSUMING THAT THE HEAVIEST SNOW AMOUNTS MISS OUR CWA TO THE
NORTHWEST...THE COMBINATION OF SNOW AND WIND IN OUR NORTHWEST
ZONES COULD STILL ULTIMATELY PROVE WORTHY OF A WINTER WEATHER
ADVISORY...ALTHOUGH WE ARE STILL SEVERAL DAYS AWAY FROM MAKING
FORMAL DECISIONS ON HEADLINES AND PLENTY IS SUBJECT TO CHANGE.
MEANWHILE...ROUGHLY THE SOUTHEAST HALF OF THE CWA INCLUDING KS
ZONES COULD ULTIMATELY SEE VERY LITTLE...IF ANY SNOW. ALTHOUGH
SOME LIGHT SNOW/FLURRIES COULD LINGER MAINLY IN NORTHEAST COUNTIES
SUNDAY EVENING...THE CURRENT TIMING SUGGESTS THAT THIS PRECIP
EVENT SHOULD BE OVER BY MIDNIGHT SUNDAY NIGHT. TEMP-WISE...HIGHS
ON SUNDAY ARE VERY TRICKY...AS TEMPS WILL LIKELY FALL VERY QUICKLY
BEHIND THE SHARP COLD FRONT. AT LEAST FOR NOW THOUGH...ANTICIPATE
READINGS AT SOME POINT DURING THE DAY TO REACH THE MID 30S
WEST...NEAR 40 CENTRAL AND MID 40S SOUTHEAST BEFORE THE COLDER AIR
BLASTS IN.

GETTING BEYOND THE MAIN SYSTEM OF INTEREST...THE MONDAY THROUGH
WEDNESDAY TIME FRAME IS PRECIPITATION-FREE AT THIS TIME...AND
CONFIDENCE REMAINS REASONABLY HIGH FOR THE DAY 5-7 TIME RANGE THAT
IT WILL REMAIN SO. ON MONDAY/MONDAY NIGHT...THE INITIAL CLOSED LOW
THAT BRINGS THE WEEKEND WEATHER WILL ALREADY PASS WELL OFF TO THE
NORTHEAST...WHILE A SECONDARY VORT MAX REMAINS WELL TO OUR
SOUTHWEST PRIMARILY TRACKING THROUGH THE SOUTHERN ROCKIES. FORCING
FOR PRECIP PRODUCTION FROM THIS SECONDARY WAVE SHOULD STAY
SOUTHWEST OF THE CWA. FROM TUESDAY INTO TUESDAY NIGHT...A FEW MORE
QUESTIONS ARISE AS THIS SOUTHWESTERN SHORTWAVE TROUGH HEADS EAST
ACROSS THE SOUTHERN PLAINS. THE LATEST GFS SOLUTION ACTUALLY TAGS
OUR FAR SOUTHERN CWA IN NORTH CENTRAL KS WITH SOME SNOW FROM THIS
WAVE...BUT THE ECWMF FOCUSES PRECIP NO CLOSER THAN THE KS/OK
BORDER...AND THE CURRENT FORECAST LEANS TOWARD THIS SOLUTION. BY
WEDNESDAY...MODELS ADVERTISE DRY NORTHWEST FLOW ALOFT IN THE WAKE
OF THE DEPARTING SOUTHERN STREAM WAVE. TEMP-WISE MONDAY THROUGH
WEDNESDAY...FOLLOWED ALLBLEND MODEL CONSENSUS WITH HIGHS GRADUALLY
REBOUNDING FROM THE LOW-MID 30S TO THE LOW-MID 40S...WITH FAR
NORTHERN AREAS POSSIBLY STAYING IN THE 20S ON MONDAY ESPECIALLY IF
A FEW INCHES OF SNOW DO MATERIALIZE.

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

AREA FORECAST DISCUSSION

NWS HASTINGS NE

1017 PM CST WED FEB 6 2013

.UPDATE...FOG HAS FORMED WHERE MOISTURE HAS POOLED JUST AHEAD OF
THE COLD FRONT AND WHERE THE WIND IS LIGHT. THIS FOG HAS BEEN
LOCALLY DENSE BUT ALSO FAIRLY SHALLOW. THE FOG WILL QUICKLY ERODE
AWAY FROM NORTHWEST TO SOUTHEAST ACROSS OUR FORECAST AREA AS THE
COLD FRONT SWEEPS THROUGH AND KICKS UP THE NORTH WIND. WILL
CONTINUE TO BE CALLING FOR DRY WEATHER ACROSS MOST OF OUR CWA
TONIGHT...AND HAVE EVEN REDUCED THE LOW POPS WE DID HAVE ACROSS
OUR FAR SOUTHEAST CWA AS LATEST 00Z RUC AND NAM MODEL RUNS KEEP
ALL THE THUNDERSTORMS SOUTHEAST OF OUR FORECAST AREA TONIGHT.
THEREFORE...HAVE ALSO PULLED THUNDER OUT OF THE FORECAST AND HWO
FOR OUR CWA...ALTHOUGH THE STORMS MAY NOT BE TOO FAR AWAY ONCE THEY
DEVELOP ON THE LOW LEVEL JET LATER TONIGHT JUST TO THE SOUTH OF
OUR CWA.

.PREV DISCUSSION... /ISSUED 532 PM CST WED FEB 6 2013/

AVIATION...00Z KGRI TAF. A LIGHT SOUTH WIND WILL CONTINUE THROUGH
MUCH OF THE EVENING...UNTIL A WEAK COLD FRONT PASSES THROUGH KGRI
JUST BEFORE MIDNIGHT. THE WIND WILL TURN NORTHERLY BEHIND THE COLD
FRONT AND BECOME A BIT BREEZY AT TIMES ESPECIALLY BY MID TO LATE
MORNING. CLOUDS WILL ALSO ACCOMPANY THE COLD FRONT WITH CLOUDY TO
MOSTLY CLOUDY SKIES THROUGH MUCH OF THE NIGHT UNTIL AROUND MID
MORNING. HOWEVER...ANY CLOUDS APPEAR TO BE WITHIN THE VFR
CATEGORY.

PREV DISCUSSION... /ISSUED 413 PM CST WED FEB 6 2013/

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

UPDATE...WESELY

AREA FORECAST DISCUSSION

NWS BURLINGTON VT

1039 PM EST FRI FEB 8 2013

.SYNOPSIS...
WINTER STORM WILL CONTINUE TO AFFECT THE NORTH COUNTRY THROUGH
SATURDAY MORNING. HIGH PRESSURE SLOWLY BUILDS OVER THE AFTERNOON AND
EVENING HOURS AND THEN REMAINS OVER THE REGION FOR THE REMAINDER OF
THE WEEKEND. ANOTHER WEATHER SYSTEM AFFECTS THE NORTH COUNTRY NEXT
MONDAY INTO WEDNESDAY...FOLLOWED BY HIGH PRESSURE FOR WEDNESDAY
NIGHT INTO THURSDAY.

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 1039 PM EST FRIDAY...NO CHANGES WERE MADE TO THE WINTER
STORM WARNINGS AND WINTER WEATHER ADVISORIES THAT REMAIN IN
EFFECT. LIGHT TO MODERATE SNOW CONTINUES ACROSS THE NORTH COUNTRY.
COMBINED EFFECTS OF CHAMPLAIN VALLEY CONVERGENCE AND MID-LEVEL
FRONTOGENESIS IMPLIED BY RAP ANALYSES LED TO THE DEVELOPMENT OF A
BAND OF STEADY MODERATE SNOW IN THE CHAMPLAIN VALLEY EARLIER THIS
EVENING WITH SNOW RATES OF 1"/HR AT TIMES. RECENT RADAR TRENDS
INDICATE THAT THESE STEADIER SNOWS ARE BECOMING LESS FREQUENT AS
THE AFOREMENTIONED AREA OF FRONTOGENESIS IS PIVOTING SOUTHWARD.
WITH THIS BEING THE CASE...ONE AREA WHERE LOCALLY ENHANCED SNOW
BANDS IS POSSIBLE THROUGH MIDNIGHT WOULD BE IN SOUTHERN VT.
OTHERWISE AM EXPECTING MAINLY LIGHT SNOW TO CONTINUE. AN
ADDITIONAL COUPLE OF INCHES OF SNOW ACCUMULATIONS POSSIBLE THROUGH
THE REST OF THE OVERNIGHT. BASED ON THESE EXPECTATIONS AND
OBSERVED SNOW TOTALS IN OUR PUBLIC INFORMATION STATEMENT...HAVE
MADE MODEST DOWNWARD ADJUSTMENTS TO SNOW ACCUMULATIONS IN WINDSOR
COUNTY AND INCREASED SNOW ACCUMULATIONS BY A COUPLE OF INCHES IN
SAINT LAWRENCE...LAMOILLE AND WASHINGTON COUNTIES. AS MENTIONED
HOWEVER...THESE CHANGES DON`T RESULT IN ANY MODIFICATIONS TO
STATED SNOW ACCUMULATIONS IN THE WINTER STORM WARNING/WINTER
WEATHER ADVISORY PRODUCTS. WINDS WILL BECOME NORTHWEST AND GUSTY
DURING THE OVERNIGHT HOURS WITH AREAS OF BLOWING/DRIFTING SNOW.

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 330 PM EST FRIDAY...BY SATURDAY MORNING...EXPECTING WINTER
STORM TO WORKING EAST OF NEW ENGLAND...PUTTING FOCUS OF REMAINING
SNOW SHOWERS OVER EASTERN VT BFR TAPERING OFF BY MIDDAY/EARLY
AFTERNOON. SHARP CUTOFF AS RIDGE BUILDS SOUTH AND EAST INTO THE
REGION. LOOKING FOR AN ADDITIONAL INCH OR TWO ACCUM FOR SAT
MORNING...W/ FOCUS IN THE CT RIVER VALLEY. SOME LGT NON-ACCUM -SW
FOR WESTERN SLOPES/CVLY FOR SAT MORNING. STRONG WINDS WILL ALSO
TAPER OFF FROM W TO E AS RIDGE INTO AREA. CLRING SKIES COMBINED
WITH FRESH SNOW COVER FOR SAT NGT HAS TEMPS DROPPING ACROSS THE
CWA. MDL GUIDANCE IS MIXED FOR OVERNGT LOWS. MAV GUIDANCE TOO CD
OVER PAST WEEK OR SO WILL BE MVG CLOSER TO MET GUIDANCE WHICH PUTS
VALLEY LOCALES IN SINGLE NUMBERS ABV ZERO AND NEGATIVE NUMBERS FOR
HIR ELEV. NICE CD DAY ON TAP FOR SUNDAY AS RIDGE CRESTS OVER THE
NORTHEAST. GOING BLW NORMAL NUMBERS FOR HIGHS SUNDAY DESPITE FULL
SUNSHINE. LOOKING FOR HIGHS IN TEENS FOR VALLEY LOCALES AND NEAR
10F FOR HIR ELEV. GOING INTO SUN NGT...RIDGE BEGINS TO SLIDE EAST
OFFSHORE...ALLOWING FOR WAA TO BUILD INTO THE ST LAW VALLEY AND
EVENTUALLY THE CVLY OVERNGT SUNDAY. THIS WILL CAP LOWS IN THESE
AREAS...ALSO AIDED BY INCR CLDS FOR N NY AS FRNTL BOUNDARY LIFTS
NE. SL CHANCE BY MON MORNING FOR -SW FOR N NY...MAINLY FOR AREAS
NEAR LK ONTARIO.

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 337 PM EST FRIDAY...THE 12Z GFS AND 12Z ECMWF SHOW GOOD
CONSISTENCY IN BRINGING A SHORTWAVE TROUGH AND ASSOCIATED SFC
EASTWARD ACROSS THE GREAT LAKES MONDAY AFTN...WITH THE SFC LOW
TRACKING NORTH OF THE INTL BORDER DURING SUNDAY NIGHT. ASSOCIATED
PERIOD OF LOW- LEVEL WAA/QG FORCING IS EXPECTED TO BRING SOME
LIGHT TO MODERATE PRECIPITATION (QPF UP TO 0.25") DURING MONDAY
AFTN INTO THE FIRST PART OF MONDAY NIGHT. VERTICAL TEMPERATURE
PROFILE BECOMES MARGINAL FOR SNOW WITH 850MB 0C LINE LIFTING NORTH
OF THE INTL BORDER IN ADVANCE OF SFC LOW FOR A TIME MONDAY AFTN. OUR
TOP-DOWN APPROACH FOR P-TYPE YIELDS A MIX OF SNOW/SLEET AND A BIT
OF RAIN FOR THE CHAMPLAIN AND S-CENTRAL VT VALLEYS. COULD BE SOME
MINOR TRAVEL IMPACTS - ESPECIALLY FOR HIGHER ELEVATIONS DURING
MONDAY AFTN AND MONDAY NIGHT...AND HAVE INDICATED POPS IN THE
LIKELY CATEGORY (60-70 PERCENT). HIGH TEMPS ON MONDAY WILL
GENERALLY BE IN THE 30S.

AS SHORTWAVE TROUGH SHIFTS EAST OF THE AREA ON TUESDAY...WINDS
BECOME MODERATE NWLY 15-25 MPH WITH POTENTIAL FOR SNOW SHOWER
ACTIVITY...ESPECIALLY IN FAVORED UPSLOPE AREAS INCLUDING THE NRN
ADIRONDACKS AND NRN GREEN MTNS. THIS NWLY FLOW GRADUALLY WEAKENS BY
TUESDAY NIGHT...SETTING UP FAIR AND TRANQUIL CONDITIONS FOR
WEDNESDAY. HIGHS TUESDAY WILL BE IN THE 30S...BUT THEN IN THE
MID-UPR 20S FOR WEDNESDAY.

MODEL SOLUTIONS DIVERGE THU-FRI...BUT WITH GENERAL TENDENCY IN SOLNS
FOR DEEPENING MID-LEVEL TROUGH ACROSS THE WRN GREAT LAKES AND ACROSS
THE NORTH-CENTRAL CONUS. THIS WOULD MEAN TEMPS SOMEWHAT ABOVE
AVERAGE FOR THE NORTH COUNTRY. POPS AT THIS POINT ARE LOW...WITH
FRONTAL SYSTEM EXPECTED TO BE DEVELOPING ACROSS THE GREAT LAKES AND
OHIO VALLEY REGION THURSDAY NIGHT INTO FRIDAY. HIGH TEMPS GENERALLY
IN THE 30S ACROSS THE NORTH COUNTRY BOTH DAYS.

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...SIGNIFICANT AVAITION IMPACTS WILL CONTINUE
FOR THE TAFS WITH THIS ISSUANCE DUE TO ONGOING WINTER STORM. PAST
COUPLE HOURS HAVE REVEALED BAND OF MODERATE SNOW WITH VISIBILITIES
AS LOW AS 1/2SM IN THE CHAMPLAIN VALLEY. IFR/LIFR VISIBILITIES ARE
EXPECTED TO PERSIST GENERALLY THROUGH AT LEAST 09Z BEFORE
VISIBILITIES BEGIN TO TREND SLOWLY TOWARD VFR. CEILINGS WILL RANGE
MVFR/IFR BEFORE TRENDING TOWARD VFR LATE MORNING SATURDAY.
NORTHEAST WINDS 5-10KTS WILL BACK TO NORTHWEST 10-15KTS AND BECOME
GUSTY AROUND 09-10Z PRODUCING POTENTIAL FOR BLOWING/DRIFTING SNOW.

OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY...STORM SYSTEM CLEARS OUT
OF THE REGION WITH HIGH PRESSURE BUILDING IN FROM THE GREAT LAKES
REGION ACROSS THE NORTH COUNTRY SAT NIGHT AND SUNDAY. THIS HIGH
PRESSURE SYSTEM WILL BRING DIMINISHING WINDS SATURDAY NIGHT AND
GENERALLY VFR CONDITIONS. WINDS SHIFT INTO THE SOUTH BY MONDAY
MORNING AS RIDGE AXIS SHIFTS EAST OF NEW ENGLAND. NEXT FRONTAL
SYSTEM BRINGS A PERIOD OF MIXED WINTRY PCPN AND MVFR/OCCASIONAL
IFR CONDITIONS MONDAY AFTN INTO MONDAY NIGHT. GENERALLY VFR
TUESDAY AND WEDNESDAY...HOWEVER LIGHT SNOW SHOWERS MAY LINGER AT
MPV/SLK WITH NW LOW-LEVEL FLOW IN PLACE.

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WARNING UNTIL 1 PM EST SATURDAY FOR VTZ001-002-
005-006-008>012-016>019.
WINTER WEATHER ADVISORY UNTIL 1 PM EST SATURDAY FOR VTZ003-004-
007.
NY...WINTER STORM WARNING UNTIL 1 PM EST SATURDAY FOR NYZ026>031-
034-035-087.

$$
SYNOPSIS...JN
NEAR TERM...JN/LOCONTO
SHORT TERM...JN
LONG TERM...BANACOS
AVIATION...BANACOS/LOCONTO

AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

1022 PM EST FRI FEB 8 2013

.SYNOPSIS...
A MAJOR STORM MOVING UP THE EAST COAST WILL BRING MODERATE TO
HEAVY SNOW TO THE AREA TONIGHT. THE STORM WILL MOVE OFF TO THE
NORTHEAST SATURDAY FOLLOWED BY CLEARING AND COLD WEATHER SATURDAY
AND SATURDAY NIGHT. MILDER WEATHER WILL RETURN ON SUNDAY... THEN
THE NEXT STORM SYSTEM COULD BRING A MIX OF PRECIPITATION ON
MONDAY.

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
1015 PM UPDATE...
UL LOW STILL SPINNING ACRS WRN NY AND EAST COAST UL WV NRNG CAPE
COD ATTM. SNOW IS DCRSG WEST OF THE I-81 CORRIDOR THO
BANDS CONTINUE TO DVLP AT RANDOM AND PRODUCE 1 TO 1.5 INCHES/HR
THUS NO CHGS WL BE MADE TO WSW HEADLINES AT THIS TIME EXCEPT FOR A
REFRESH OF WRDG. LATEST RAP UPGLIDE IN THE 285K LAYER INDICATES
SNOW WL CONTINUE ALONG THE I-81 CORRIDOR FOR THE NEXT HR BFR BCMG
SIGNIFICANTLY LIGHTER.

SNOW IS BCMG MODERATE TO HVY AT TIMES ACRS THE ERN CNTYS AS
MOISTURE IS INCRSG AND BEING LIFTED BTWN TWO SEPARATE STORMS.
DUAL-POL INDICATING 2-3 INCHES PER HOUR IN OTSEGO/DELAWARE/WAYNE
CNTYS AND EXPECT THIS TO TRANSLATE SLOWLY OFF TO THE EAST. A
LITTLE CONCERNING AS THESE WERE THE LAST CNTYS TO SEE SNOWFALL
TONIGHT BUT THEY WILL BE MAKING UP FOR IT IN A BIG WAY THRU MRNG.

ONLY MINOR TWEAKS TO STORM TOTALS, CLOSER TO 7 INCHES AREA-WIDE
WITH ERN ZONES EXPECTING 6-9 INCHES. OTHER THAN THESE CHGS HV JUST
TWEAKED HRLY T/TD VALUES.

630 PM UPDATE...
SFC LOW CONTS TO DROP AND IS NOW DOWN TO 985MB SOUTH OF CAPE COD.
THE MAIN WX STORY FOR US CONTS TO BE UL TROF DIVING THRU WRN NY
WITH ECHOES RAPIDLY INTENSIFYING ACRS WRN STEUBEN CNTY. MODERATE-
OCNLY HVY SNOW IS NOW LOCATED ALG THE I-81 CORRIDOR AND AS UL TROF
DIVES SOUTHEAST THRU CNTRL PA THIS BAND WL LKLY PIVOT AND CONT TO
BRING SNOW TO THE AREA THRU LATE EVNG AND POSSIBLY EVEN THRU
MIDNIGHT. MOST INTENSE RATES ARE UP TO 2 INCHES PER HR AND
WIDESPREAD 1 TO 1.5 INCH/HR AMNTS PER DUAL-POL RADAR ESTIMATES.

LATEST RAP AND HIRES NMM MODELS INDICATE SOME FORM OF BANDING TO
PERSIST ALONG I-81 CORRIDOR THRU 02Z AND ERN THIRD OF CWA THRU
06Z. THIS WL ALLOW SNOWFALL AMNTS TO APPRCH WRNG CRITERIA. AS THE
SNOW CONTS TO FALL, TEMPS ALOFT WL COOL THIS EVNG WITH FLAKES BCMG
BIGGER, WHEREAS FINE SNOW OCCURRED THIS AFTN. THIS WL LKLY RESULT
IN WIDESPREAD 6-8 INCH AMNTS TONIGHT WITH SNOW TOPPING 10 INCHES ACRS
EXTRM ERN CNTYS.

330 PM UPDATE...
SURFACE LOW PRESSURE OFF THE EAST COAST IS DOWN TO 992 MB EAST OF
DELMARVA. HOWEVER THE KEY FEATURE TO NOTE FOR OUR AREA IS A STRONG
UPPER LEVEL WAVE TRACKING SOUTHEAST FROM THE EASTERN GREAT LAKES.
THE TRACK OF THIS SYSTEM WILL BE CRITICAL FOR SNOW AMOUNTS IN OUR
AREA TONIGHT. THE MID-LEVEL CENTER IS CURRENTLY OVER LAKE ERIE...
AND A DRY SLOT HAS PUSHED EAST AROUND THE SOUTH SIDE OF THIS
SYSTEM SHUTTING PRECIPITATION OFF OVER WESTERN PENNSYLVANIA. THIS
DRY SLOT IS PROGRESSING STEADILY EAST ACROSS CENTRAL PA LATE THIS
AFTERNOON. HOWEVER... THE TRACK OF THIS UPPER SYSTEM IS EXPECTED
TO BE SOUTHEASTWARD ACROSS CENTRAL PA THIS EVENING... WHICH SHOULD
SHUNT THE DRY SLOT OFF THE SOUTH OF OUR AREA. EXPECT THE DRY SLOT
TO GET ABOUT HALF WAY ACROSS THE TWIN TIERS EARLY THIS EVENING...
THEN STOP AND POSSIBLY EVEN BUILD BACK TO THE WEST AS THE ENTIRE
STORM PIVOTS AND MOISTURE BEGINS TO WORK BACK IN FROM THE EAST
AROUND THE NORTH SIDE OF THE UPPER LOW. AS A RESULT... MODERATE TO
AT TIMES HEAVY SNOW IS LIKELY TO PERSIST... AT LEAST ACROSS THE
EASTERN 2/3 OF OUR FORECAST AREA... UNTIL AFTER MIDNIGHT. THIS
WILL ALLOW WARNING CRITERIA SNOWS TO ACCUMULATE IN MOST AREAS. AT
THIS TIME THIS SCENARIO IS SUPPORTED BY ALL OF OUR SHORT RANGE
GUIDANCE... AS WELL AS RADAR AND SATELLITE LOOPS WHICH SHOW THE
ENTIRE SYSTEM PIVOTING AS IT TAKES ON AN INCREASINGLY NEGATIVE
TILT AND RADAR RETURNS EXPAND.

INTENSITY OF THE SNOW WILL BE INTERESTING THIS EVENING. WE HAVE
ALREADY GOTTEN A REPORT OF 3.7 INCHES IN 90 MINUTES OVER WAYNE
COUNTY NY JUST SOUTH OF LAKE ONTARIO. SEVERAL OTHER SPOTTER
REPORTS INDICATE THAT HEAVY SNOW IS DEVELOPING IN NORTH-SOUTH
ORIENTED BANDS OVER THE WESTERN HALF OF OUR FORECAST AREA. NAM
CROSS-SECTIONS AND PLAN VIEW CHARTS SHOW A PRONOUNCED NORTH-SOUTH
BAND OF FRONTOGENESIS DEVELOPING IN THE 850-700 MB LAYER NEAR THE
I-81 CORRIDOR THROUGH 00Z... WITH A LAYER OF NEGATIVE EPV (REDUCED
STABILITY) ABOVE THE FRONTOGENESIS. THE FRONTOGENESIS PERSISTS
ACROSS OUR CENTRAL COUNTIES THROUGH 03Z BEFORE MOVING EAST. THIS
PATTERN IMPLIES THE POTENTIAL FOR SOME HEAVY BANDS OF SNOW
PERSISTING THROUGH ABOUT 06Z WITH SNOWFALL RATES OF 1 TO 2 INCHES
PER HOUR POSSIBLE.

SNOW WILL PULL EAST OF THE AREA AFTER 06Z. WILL HAVE TO WATCH FOR
SOME SNOW BANDS DEVELOPING AND PERSISTING SOUTH OF THE FINGER
LAKES AFTER 09Z WITH A FEW INCHES OF EXTRA SNOW POSSIBLE IN
TIOGA/TOMPKINS COUNTIES.

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
230 PM UPDATE... MAJOR WINTER STORM WILL CONTINUE TO PULL AWAY FROM OUR
AREA ON SAT. HOWEVER...IN THE AM HRS...SOME MULTI-BAND/FINGER LKS
LES BANDS ARE LIKELY...AS LONG AS THE DEEPER SYNOPTIC MOISTURE
LINGERS...WITH LOW-LVL CAA...AND A 320-340 FLOW. WE`VE ADDED THE
POTENTIAL FOR LOCALIZED 1-2" SNOWS THIS PD...SPCLY DOWNWIND FROM
CAYUGA LAKE. DURG THE AFTN (STARTING 15-18Z)...SIG DRYING IS
PROGGED...WITH SKIES EXPECTED TO CLEAR OUT AREA-WIDE. WINDS WILL
BE GUSTY ON SAT...OWING TO A TIGHT PRES GRADIENT BETWEEN THE
INTENSE STORM OFF THE NEW ENG COAST...AND HIGH PRESSURE TO OUR W.

SAT NGT LOOKS QUITE COLD FROM THIS VANTAGE PT...WITH MAINLY CLEAR
SKIES...FAIRLY FRESH SNOW COVER...AND THE COLDEST AIR COMING IN AT
THAT TIME. WE EXPECT OUR NORMALLY COLDER RURAL VLYS TO DROP BELOW ZERO.

SUN LOOKS QUIET...WITH SUNSHINE FADING BEHIND INCREASING CLDS IN THE AFTN.

A FAST MOVING UPR WV AND SFC FRNT ARE STILL EXPECTED TO CROSS
NY/PA EARLY MON...WITH A QUICK SHOT OF PCPN BETWEEN MAINLY 09Z AND
15Z. PTYP CONTS TO BE A CONCERN...AS A WARM LYR CLEARLY PRESENTS
ITSELF IN THE 900-850 MB LYR. AT THE SAME TIME...SFC TEMPS WILL BE
COLD...AND THUS A PD OF -FZRA IS LIKELY. THIS MENTION WILL STILL
BE MADE IN THE HWO. MON AFTN...AS TEMPS WARM AND PCPN TAPERS
OFF...WE SHOULD BE LEFT WITH SCTD -SHRA/SPRINKLES...FOR THE MOST PART.

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
1 PM UPDATE...
FOLLOWED HPC GUIDANCE. MODELS SIMILAR. MULTIPLE WEAK SYSTEMS GOING
THROUGH. COLD ENOUGH FOR MOSTLY SNOW BUT SFC TEMPERATURES SLIGHTLY
ABOVE NORMAL. TEMPERATURES NOT COLD ENOUGH FOR DECENT LAKE EFFECT
SNOW. MONDAY NIGHT THE FIRST SYSTEM WITH A MIX CHANGING TO SNOW. A
SECONDARY COLD FRONT GOES THROUGH TUESDAY. WEDNESDAY SOME
DIFFERENCES WITH THE GFS GETTING INTO PA WITH SNOW WHILE THE EURO
KEEPS THE SNOW SOUTHEAST WITH A COASTAL STORM. HIGH PRESSURE
THURSDAY THEN ANOTHER STORM FRIDAY TO SATURDAY.

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
POTENT WINTER STORM CONTINUES TO SPIN SNOW ACROSS NY AND PA,
BRINGING WIDESPREAD IFR CONDITIONS TO AREA TERMINALS.

THE BACK EDGE OF THE STEADY MODERATE SNOW HAS MOVED INTO CHEMUNG
COUNTY, SO THE ELM CEILING AND VISIBILITY WILL LIKELY FLUCTUATE
QUITE A BIT OVER THE NEXT FEW HOURS, IN AND OUT OF MODERATE SNOW
SHOWERS.

CEILINGS WILL GENERALLY RANGE FROM 300 TO 900 FEET, WITH
VISIBILITIES BOUNCING BETWEEN 1/2SM AND 2SM THROUGH 4Z. THEREAFTER
THERE WILL BE FLUCTUATIONS UPWARD INTO MVFR TERRITORY FOR A FEW
HOURS, AS WINDS SWING TO THE NORTHWEST AND SNOW ACTIVITY BECOMES
MORE SCATTERED.

DRIER AIR WILL ARRIVE BY LATE MORNING OR MIDDAY SATURDAY, BRINGING
VFR CONDITIONS TO MOST SITES.

.OUTLOOK...

SAT AFTN TO SUN...VFR.

SUN NGT/MON...MVFR/IFR POSSIBLE IN A WINTRY MIX /INCLUDING
FREEZING RAIN/...CHANGING TO ALL RAIN ON MON.

MON NGT TO TUE NGT...SCT MVFR CNTRL NY IN -SHSN...VFR ELSEWHERE.

WED...IMPROVE TO VFR.

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WARNING UNTIL 7 AM EST SATURDAY FOR PAZ038>040-
043-044-047-048-072.
NY...WINTER STORM WARNING UNTIL 7 AM EST SATURDAY FOR NYZ009-
015>018-022>025-036-037-044>046-055>057-062.

$$
SYNOPSIS...MSE
NEAR TERM...MSE/PVN
SHORT TERM...MLJ
LONG TERM...TAC
AVIATION...DJP

AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

639 PM EST FRI FEB 8 2013

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
630 PM UPDATE...
SFC LOW CONTS TO DROP AND IS NOW DOWN TO 985MB SOUTH OF CAPE COD.
THE MAIN WX STORY FOR US CONTS TO BE UL TROF DIVING THRU WRN NY
WITH ECHOES RAPIDLY INTENSIFYING ACRS WRN STEUBEN CNTY. MODERATE-
OCNLY HVY SNOW IS NOW LOCATED ALG THE I-81 CORRIDOR AND AS UL TROF
DIVES SOUTHEAST THRU CNTRL PA THIS BAND WL LKLY PIVOT AND CONT TO
BRING SNOW TO THE AREA THRU LATE EVNG AND POSSIBLY EVEN THRU
MIDNIGHT. MOST INTENSE RATES ARE UP TO 2 INCHES PER HR AND
WIDESPREAD 1 TO 1.5 INCH/HR AMNTS PER DUAL-POL RADAR ESTIMATES.

SUN LOOKS QUIET...WITH SUNSHINE FADING BEHIND INCREASING CLDS IN THE AFTN.

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
POTENT WINTER STORM CONTINUES TO SPIN SNOW ACROSS NY AND PA,
BRINGING WIDESPREAD IFR CONDITIONS TO AREA TERMINALS.

DRIER AIR WILL ARRIVE BY LATE MORNING OR MIDDAY SATURDAY, BRINGING
VFR CONDITIONS TO MOST SITES.

.OUTLOOK...

SAT AFTN TO SUN...VFR.

SUN NGT/MON...MVFR/IFR POSSIBLE IN A WINTRY MIX /INCLUDING
FREEZING RAIN/...CHANGING TO ALL RAIN ON MON.

MON NGT TO TUE NGT...SCT MVFR CNTRL NY IN -SHSN...VFR ELSEWHERE.

WED...IMPROVE TO VFR.

$$
SYNOPSIS...MSE
NEAR TERM...MSE/PVN
SHORT TERM...MLJ
LONG TERM...TAC
AVIATION...DJP

AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

635 PM EST FRI FEB 8 2013

SUN LOOKS QUIET...WITH SUNSHINE FADING BEHIND INCREASING CLDS IN THE AFTN.

.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
1230 PM UPDATE...
VFR CONDITIONS WILL DEGRADE TO IFR THIS AFTERNOON. IFR TO CONTINUE
INTO EARLY MORNING THEN IMPROVE TO VFR FROM SW TO NE SATURDAY
MORNING. STEADY SNOW MOVING EAST FROM WRN NY AND CENTRAL PA. ONCE
THE SNOW STARTS BETWEEN 19 AND 21Z CONDITIONS WILL DROP QUICKLY TO
IFR WITHIN 2 HOURS. AVP ON THE EDGE OF THE COASTAL LOW. IFR AND
SNOW TO MPO BUT THEY MAY HAVE TO WAIT FOR THE SNOW AT STATE
COLLEGE. CONDITIONS BETWEEN 22 AND 04Z WILL FALL TO BELOW 1 MILE
WITH CIGS BELOW 1K FT. SLOW IMPROVEMENT LATE TONIGHT WITH SOME
LAKE MOISTURE. WINDS INCREASE THEN TOO KEEPING VSBYS LOW WITH
BLOWING SNOW.

E TO SE WINDS AT 5 TO 10 KTS BACKING TO NE LATE THIS AFTN TO N
THIS EVE THEN NW LATE TONIGHT THROUGH SATURDAY. LATE TONIGHT TO
SATURDAY WINDS INCREASE TO 10 TO 15 WITH HIGHER GUSTS.

.OUTLOOK...

SAT AFTN TO SUN...VFR.

SUN NGT/MON...MVFR/IFR POSSIBLE IN A WINTRY MIX /INCLUDING
FREEZING RAIN/...CHANGING TO ALL RAIN ON MON.

MON NGT TO TUE NGT...SCT MVFR CNTRL NY IN -SHSN...VFR ELSEWHERE.

WED...IMPROVE TO VFR.

$$
SYNOPSIS...MSE
NEAR TERM...MSE/PVN
SHORT TERM...MLJ
LONG TERM...TAC
AVIATION...TAC

AREA FORECAST DISCUSSION

NWS BURLINGTON VT

629 PM EST FRI FEB 8 2013

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 528 PM EST FRIDAY...SFC CYCLONE UNDERGOING RAPID DEEPENING
NEAR THE 40N/70W BENCHMARK. RAP ANALYSES SHOW A ZONE OF DEVELOPING
700 MB FRONTOGENESIS EXTENDING ACROSS CENTRAL VERMONT INTO THE
NORTHERN ADIRONDACKS. BELIEVE THIS AS WELL AS SOME CONVERGENCE IN
THE CHAMPLAIN VALLEY WILL HELP TO FOCUS BANDS OF MODERATE TO
LOCALLY HEAVY SNOW ACROSS CENTRAL VERMONT...THE CHAMPLAIN VALLEY
AND THE NORTHERN ADIRONDACKS AS THE EVENING PROGRESSES. COMPOSITE
RADAR IS ALREADY BEGINNING TO BEAR THIS OUT WITH BANDED 25 TO 30
DBZ ECHOES. EXPECT THESE TRENDS TO CONTINUE THROUGH AT LEAST THE
EARLY OVERNIGHT HOURS. HAVE UPDATED THE WINTER STORM WARNING TEXT
TO REFLECT THE TIMING OF THESE BANDS. GUSTY NORTHWEST WINDS WILL
LEND ITSELF TO AREAS OF BLOWING AND DRIFTING SNOW.
OTHERWISE...HAVE MADE NO OTHER CHANGES TO THE CURRENT FORECAST
EXCEPT TO BLEND IN CURRENT OBSERVATIONAL DATA.

PREVIOUS DISCUSSION ISSUED AT 330 PM EST FRIDAY...
WINTER STORM CONTINUES TO AFFECT THE CWA THIS AFTNOON...WITH
VARYING AMTS ACROSS THE AREA THUS FAR. HIGHEST TOTALS ATTM ARE
ACROSS THE NORTHERN CVLY INTO N NY. LESSER AMTS OVER SOUTHERN
ZONES DUE TO AREA BEING BETWEEN THE TWO SFC LOWS THRU THE DAY.
INLAND LOW IS EXPECTED TO BREAK DOWN OVERNGT...TRANSFERRING ENERGY
TO OFFSHORE LOW. MUCH OF SNOW OCCURRING NOW WILL SHIFT TO E VT
OVERNGT TOWARDS SATURDAY MORNING. DESPITE LACK OF ACCUM SNOWS FOR
SC VT...THESE AREAS WILL MAKE UP FOR IT OVERNGT. HAVE ADJUSTED
AMTS THRU THE OVERNGT FOR STORM TOTALS. ADJUSTED NUMBERS DOWNWARD
BY SEVERAL INCHES FOR PORTIONS OF ADDISON/RUTLAND COUNTIES DUE TO
DOWNSLOPING/SHADOWING EFFECTS. HIGHEST AMTS FOR CWA WILL CONTINUE
TO LEAN TOWARDS DACKS/SLV AND SE VT...ESPECIALLY IN HIR ELEV OF
WINDSOR COUNTY. OVERALL 8-16 INCHES STORM ACCUM WITH LCL AMTS HIR
NEAR 20 INCHES IN AFOREMENTIONED AREAS. WINDS ON THE INCR AS WELL
WITH GRADIENT SHIFTING WITH COASTL LOW MVG TOWARDS CAPE COD. TIGHT
GRADIENT WILL SUPPORT GUST POTENTIAL 30-40 MPH.

.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...SIGNIFICANT AVAITION IMPACTS WILL CONTINUE
FOR THE TAFS WITH THIS ISSUANCE DUE TO ONGOING WINTER STORM. PAST
COUPLE HOURS HAVE REVEALED BAND OF MODERATE SNOW WITH VISIBILITIES
AS LOW AS 1/2SM IN THE CHAMPLAIN VALLEY. IFR/LIFR VISIBILITIES ARE
EXPECTED TO PERSIST GENERALLY THROUGH AT LEAST 09Z BEFORE
VISIBILITIES BEGIN TO TREND SLOWLY TOWARD VFR. CEILINGS WILL RANGE
MVFR/IFR BEFORE TRENDING TOWARD VFR LATE MORNING SATURDAY.
NORTHEAST WINDS 5-10KTS WILL BACK TO NORTHWEST 10-15KTS AND BECOME
GUSTY AROUND 09-10Z PRODUCING POTENTIAL FOR BLOWING/DRIFTING SNOW.

$$
SYNOPSIS...JN
NEAR TERM...JN/LOCONTO
SHORT TERM...JN
LONG TERM...BANACOS
AVIATION...BANACOS/LOCONTO

AREA FORECAST DISCUSSION

NWS WILMINGTON NC

621 PM EST FRI FEB 8 2013

.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA THIS EVENING...WITH COOL AND DRY
HIGH PRESSURE BUILDING INTO THE AREA OVERNIGHT AND SATURDAY. THIS
HIGH WILL SLIP OFF THE COAST SUNDAY AHEAD OF AN APPROACHING COLD
FRONT. THE COLD FRONT WILL STALL NEAR THE AREA THROUGH THE MIDDLE OF
NEXT WEEK...BRINGING RAIN CHANCES MONDAY THROUGH WEDNESDAY. DRY HIGH
PRESSURE WILL RETURN FOR THE END OF NEXT WEEK.

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 630 PM FRIDAY...THE COLD FRONT IS CURRENTLY MOVING EAST ACROSS
THE CAROLINA PIEDMONT REGION AND SHOULD CROSS THE COASTAL PLAIN BY
MIDNIGHT. THE CLOUD COVER AHEAD OF THE FRONT HAS YET TO YIELD ANY
UPSTREAM PRECIP REPORTS AND RADAR COMPOSITES REMAIN CLEAR. I HAVE
REMOVED THE MENTION OF EVENING SHOWERS FROM THE FORECAST. OTHERWISE
COLD ADVECTION BEHIND THE FRONT SHOULD DROP LOWS INTO THE 30S
AREAWIDE BY DAYBREAK SATURDAY. PREVIOUS DISCUSSION FROM 300 PM
FOLLOWS...

A RICKETY COLD FRONT CROSSING THE EASTERN APPALACHIAN FOOTHILLS WILL
PROMPT A BACKING OF SURFACE WINDS TO THE SOUTHWEST IN THE LATE
AFTERNOON TO VERY EARLY EVENING BEFORE CROSSING THE IMMEDIATE COAST
IN THE MID-EVENING FOLLOWED BY A RESURGENCE IN NW WINDS AND MODERATE
COLD AIR ADVECTION FOR THE OVERNIGHT PERIOD. SUITE OF HIGH
RESOLUTION NEAR-TERM MODELS SUCH AS THE HRRR AND NSSL WRF SUGGEST A
COUPLE LIGHT SHOWERS IN PASSING OF THIS FRAIL FRONT BETWEEN
500PM-900PM ACROSS OUR CWA. QPF VALUES WILL REMAIN EXCEEDINGLY LOW
AND NO GUARANTEE OF RAIN MEASURING BEYOND A TRACE BUT TIME SECTIONS
SHOW ADEQUATE RH AND WEAK LIFT WARRANTING A SLIGHT CHANCE OF A FEW
SHOWERS LATE THIS AFTERNOON TO MIDDLE EVENING.

COLD AIR ADVECTION AND CLEARING LATE EVENING AND OVERNIGHT WILL
BRING CHILLY TEMPERATURES INTO DAYBREAK SATURDAY...MAINLY NEAR
30 DEGREES OVER THE FAR W-NW INTERIOR AND MIDDLE 30S NEAR AND
ALONG THE COAST. BRISK NW WINDS WILL PREVENT MINIMUM TEMPERATURES
FROM DIPPING AS LOW THEY COULD UNDER CLEARING SKIES...BUT
FACTORING IN THE WIND SHOULD PRODUCE APPARENT TEMPS/WIND CHILLS
IN THE MIDDLE TO UPPER 20S WITH FIRST LIGHT OF SATURDAY.

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...VERY STRONG STORM SYSTEM WILL BE OFF THE NEW
ENGLAND COAST AT THE START OF THE PERIOD WITH SURFACE HIGH PRESSURE
RIDGING DOWN THE COAST BEHIND IT. AT THE SAME TIME...LONG WAVE RIDGE
BUILDS ACROSS THE EAST AT 500MB...WITH HEIGHTS RISING TO AS MUCH AS
576DM ON SUNDAY. THIS GENERALLY WOULD SUPPORT WARM AND QUIET
WEATHER...BUT A FEW CAVEATS WILL KEEP TEMPS SLIGHTLY COOL...AND
BRING INCREASINGLY UNSETTLED WEATHER AT THE END OF THE PERIOD.

AS SURFACE HIGH RIDGES DOWN BEHIND THE DEPARTING COASTAL
STORM...COOL NORTH WINDS WILL ENVELOP THE EASTERN CAROLINAS. AT THE
SAME TIME...AS THE RIDGE BUILDS ALOFT...LOW LEVEL THICKNESSES
INCREASE. THESE TWO WILL WORK AGAINST ONE ANOTHER...AND THE END
RESULT WILL BE A NEAR CLIMO DAY WITH AMPLE SUNSHINE ON SATURDAY.
HIGHS SATURDAY WILL REACH INTO THE MID 50S...APPROACHING 60 IN THE
FAR SOUTH. HIGH PRESSURE NEARLY OVERHEAD SATURDAY NIGHT WILL KEEP A
WEAK PRESSURE GRADIENT...AND ALTHOUGH SOME HIGH CLOUDS WILL BEGIN TO
FILTER IN DURING THE NIGHT...GOOD RADIATIONAL COOLING IS STILL
EXPECTED. THIS WILL HELP MINS FALL TO AROUND FREEZING...LOWER IN THE
TYPICALLY COLDER SPOTS.

SUNDAY IS A TRANSITION DAY AS SURFACE HIGH DRIFTS OFF THE
MID-ATLANTIC COAST SETTING UP WARM/MOIST RETURN FLOW INTO THE AREA.
MEANWHILE A SURFACE LOW WILL BE MOVING THROUGH THE GREAT PLAINS
PUSHING A COLD FRONT TOWARDS THE CAROLINAS. DECENT MOIST ADVECTION
OCCURS AHEAD OF THIS FRONT...AND A STRENGTHENING SOUTHERLY LLJ
OVERTOPPING THE WEAKENING RIDGE INCREASES ISENTROPIC LIFT IN
CONJUNCTION WITH ADVECTION OF THE MID-LEVEL THETA-E RIDGE. GUIDANCE
IN GOOD AGREEMENT IN OVERALL TIMING OF FEATURES LATE SUNDAY
NIGHT...BUT THE ECMWF IS A LITTLE MORE ROBUST WITH ITS LIFT AND
PRECIP POTENTIAL. WILL LEAN THIS DIRECTION BASED OFF RECENT ECMWF
PERFORMANCE...AND HENCE WILL SHOW POP INCREASING TO HIGH CHANCE AT
THE END OF THE PERIOD IN THE WEST...LOW CHANCE EAST.

SUNDAY WILL BE JUST A TAD WARMER THAN SATURDAY THANKS TO BREAKDOWN
OF COOL NORTH SURFACE FLOW...BUT OVERALL HEATING WILL BE
INCREASINGLY LIMITED BY CLOUD COVER. STILL EXPECT HIGHS IN THE UPPER
50S...LOW 60S FAR SOUTH. VERY LITTLE DIURNAL RANGE ANTICIPATED INTO
SUNDAY NIGHT THANKS TO CLOUDS AND RAIN...AND AN ATYPICAL DIURNAL
CURVE IS LIKELY WITH TEMPS FALLING JUST AFTER DARK...AND THEN
RISING SLOWLY THROUGH THE NIGHT. EARLY MINS WILL FALL INTO THE
MID/UPPER 40S BEFORE RISING TOWARDS DAYBREAK.

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...A HIGH AMPLITUDE RIDGE WILL SHIFT OFFSHORE BY
THE START OF THE FORECAST PERIOD. LOW PRESSURE WILL MOVE ACROSS THE
GREAT LAKES AND INTO SE CANADA MON-TUE...DRAGGING A COLD FRONT INTO
THE EASTERN CAROLINAS LATE MON NIGHT AND TUE MORNING. A DEEP AND
RATHER MOIST SW TO WSW FLOW WILL QUICKLY DEVELOP AHEAD OF THE FRONT
WITH PRECIPITABLE WATER VALUES CLIMBING TO ABOUT AN INCH AND A HALF.
THE FRONT WILL BECOME PARALLEL TO THE MEAN FLOW...BECOMING MORE OR
LESS STATIONARY OVERHEAD OR JUST TO OUR S MID WEEK. A VIGOROUS
SOUTHERN STREAM SYSTEM WILL MOVE OUT OF THE FOUR CORNERS REGION
TUE...AIDING IN THE DEVELOPMENT OF LOW PRESSURE IN THE GULF OF
MEXICO. THIS AREA OF LOW PRESSURE WILL MOVE NE ALONG THE STALLED OUT
BOUNDARY AND ACROSS THE SOUTHEAST STATES TUE NIGHT AND WED. LOW
PRESSURE IS EXPECTED TO MOVE OFF THE CAROLINA COAST DURING WED AND
BEGIN TO INTENSIFY AS IT MOVES NE AND AWAY FROM THE AREA LATE DAY
AND WED NIGHT.

THUS...A VERY UNSETTLED PERIOD AND ALL OF THE AREA IS EXPECTED TO
RECEIVE PRECIPITATION SOMETIME DURING THE MON THROUGH WED TIME
FRAME. THE CHARACTER OF THE PRECIPITATION IS EXPECTED TO BE
STRATIFORM AS THE AREA OF LOW PRESSURE IS EXPECTED TO PASS S AND
THEN E OF THE FORECAST AREA. SHOULD THE GFS VERIFY...THEN THE AREA
OF LOW PRESSURE WOULD TRACK FURTHER N AND WITH THAT THERE MAY BE AT
LEAST SOME CONVECTIVE ELEMENTS AS THE PROXIMITY OF THE WARM SECTOR
WILL ALLOW FOR GREATER INSTABILITY. SINCE THE TIMING AND
JUXTAPOSITION OF THE SYNOPTIC FEATURES MAY STILL CHANGE SLIGHTLY...
I WAS HARD PRESSED TO GO CATEGORICAL FOR MOST AREAS DURING ANY
12-HOUR PERIOD. HOWEVER...SINCE THE AREA OF LOW PRESSURE WILL BE
MAKING ITS CLOSEST APPROACH AND THE STRONGEST SW LOW-LEVEL JET WILL
BE REALIZED TUE NIGHT AND EARLY WED...WILL BUMP POPS UP TO
CATEGORICAL DURING THIS TIME...EXCEPT FOR THE NW CORNER OF THE
FORECAST AREA.

HIGH PRESSURE WILL FILL IN BEHIND THE DEPARTING AREA OF LOW
PRESSURE...MOVING FROM THE GULF COAST STATES THU TO THE SOUTHEAST
STATES FRI.

ABUNDANCE OF CLOUDS MON THROUGH WED WILL KEEP LOWS WELL ABOVE NORMAL
BOTH MON AND TUE NIGHT. HIGHS WILL ALSO BE ABOVE NORMAL AS THERE
WILL BE NO INFLUX OF COLDER AIR EVEN BEHIND THE COLD FRONT. AS LOW
PRESSURE INTENSIFIES AS IT MOVES AWAY FROM THE CAROLINA COAST
WED...IT WILL BRING COLDER AND DRIER AIR INTO THE EASTERN CAROLINAS.
TEMPERATURES WILL RETURN TO MORE SEASONABLE LEVELS LATE WEEK.

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...SECONDARY FRONT...MODIFIED ARCTIC AIR...WILL SPILL INTO
THE REGION THROUGH THE OVERNIGHT HOURS. A BRIEF STRATA CU CEILING
WILL OCCUR BRIEFLY AS THE FRONT PASSES THROUGH. HIGH CONFIDENCE FOR
VFR CONDITIONS. WEST WINDS WILL SHIFT TO THE NORTH NORTHWEST ON
SATURDAY AS HIGH PRESSURE BUILDS IN. MODERATE GRADIENT WILL PRODUCE
GUSTS APPROACHING 20 KTS BY MIDDAY WITH WEAK COLD AIR ADVECTION.

EXTENDED OUTLOOK...VFR WILL PERSIST THROUGH THE WEEKEND. A NEAR
STATIONARY FRONT WILL SET UP ON MONDAY WITH UNSETTLED CONDITIONS
THROUGH WEDNESDAY.

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM FRIDAY...A DRY COLD FRONT ACROSS THE CAROLINA
PIEDMONT WILL ROLL OFFSHORE LATE THIS EVENING...SHIFTING WESTERLY
WINDS TO THE NORTHWEST WITH AN INCREASE IN WIND SPEEDS EXPECTED. NO
SIGNIFICANT CHANGES WERE MADE TO THE FORECAST. A SMALL CRAFT
ADVISORY WILL REMAIN IN EFFECT FOR THE NC WATERS...AND AN EXERCISE
CAUTION HEADLINE WILL REMAIN POSTED FOR THE SC WATERS WHERE WINDS
WILL INCREASE TO A SOLID 20 KNOTS BEHIND THE FRONT BY MIDNIGHT.
PREVIOUS DISCUSSION FROM 300 PM FOLLOWS...

EXERCISE CAUTION CONDITIONS WILL PREVAIL ACROSS ALL WATERS THROUGH
EVENING NOT ONLY FOR SETTLING SEAS FROM THE PREVIOUS STORM
SYSTEM...BUT A RESURGENCE OF NW WINDS AS A COLD FRONT CROSSES THE
WATERS LATE THIS EVENING. A SMALL CRAFT ADVISORY HAS BEEN HOISTED
FOR THE NC WATERS FROM MIDNIGHT TO 6AM TO ADDRESS FREQUENT 25 KT NW
WIND GUSTS EXPECTED. ADDITIONALLY...THE INCREASING OFFSHORE WIND
LATE TONIGHT WILL COINCIDE WITH AN ASTRONOMICALLY LOW TIDE TO
PRODUCE LOW-WATER CONDITIONS A FEW HOURS EITHER SIDE OF MIDNIGHT AND
AN MWS WAS ISSUED EARLIER TO GET THE WORD OUT TO MARINERS. MODERATE
W-WSW WINDS INTO EVENING WILL TURN TO NW LATE TONIGHT AND INCREASE AS
THE FRONT CLEARS THE WATERS. IT APPEARS THE NW SURGE WILL BE
SHORT-LIVED AND THE ADVISORY WILL RUN THROUGH 600 AM SATURDAY. NO
TSTMS OR RESTRICTIONS TO VISIBILITY EXPECTED ON THE 0-20 NM WATERS
THROUGH TONIGHT. SEAS WILL REMAIN SOMEWHAT AGITATED AS W-NW WINDS
INTERACT WITH RESIDUAL SE WAVES FROM THE PREVIOUS STORM SYSTEM.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...HIGH PRESSURE RIDGES DOWN FROM THE NORTH
BEHIND A POWERFUL COASTAL STORM WHICH WILL BE MOVING SLOWLY OFF THE
NEW ENGLAND COAST AT THE START OF THE PERIOD. THIS CREATES GUSTY
N/NW WINDS OF 15-20 KTS EARLY SATURDAY...EASING THROUGH THE DAY TO
AROUND 10 KTS WHILE VEERING TO THE NE BY SUNDAY MORNING. SEAS OF 2-4
FT EARLY WILL QUICKLY FALL TO 1-3 FT...LOWEST NEAR SHORE...DUE TO
THE OFFSHORE FETCH. ON SUNDAY...HIGH PRESSURE DRIFTS OFFSHORE
ALLOWING WINDS TO VEER FROM NE TO SE...AND FINALLY S BY SUNDAY
NIGHT. THESE WINDS WILL GENERALLY BE 10-15 KTS...BUT INCREASE LATE
AHEAD OF AN ADVANCING COLD FRONT...UP TO 15-20 KTS. THESE WINDS HELP
DRIVE SEAS UPWARDS THROUGH THE DAY...BECOMING 4-6 FT AT THE VERY END
OF THE PERIOD...AND A SMALL CRAFT ADVISORY MAY BE NECESSARY.

LONG TERM/MONDAY THROUGH TUESDAY/...
AS OF 3 PM FRIDAY...UNSETTLED WEATHER IS EXPECTED ACROSS THE WATERS
THROUGH MID WEEK. SW WINDS ON MON WILL SHIFT TO NW AND THEN N LATE
MON NIGHT AND TUE MORNING BEHIND A COLD FRONT. THIS FRONT WILL
LIKELY STALL NEARBY WITH WINDS VEERING TO NE DURING TUE AND THEN ALL
THE WAY AROUND TO SE AND S TUE NIGHT AS LOW PRESSURE APPROACHES FROM
THE SW. AS LOW PRESSURE INTENSIFIES AS IT MOVES NE OF THE WATERS...
WINDS WILL VEER TO WESTERLY WED AFTERNOON. THE STRONGEST WINDS THIS
PERIOD ARE EXPECTED MON WHEN SW WINDS...UP TO 20 TO 25 KT...WILL
ALLOW SEAS TO BUILD TO 5 TO 7 FT AND A SMALL CRAFT ADVISORY MAY BE
ISSUED FOR AT LEAST PORTIONS OF THE WATERS WITH LATER FORECAST
ISSUANCES. WINDS AND SEAS WILL BE ON A DOWNWARD TREND MON NIGHT.
WINDS AND SEAS WILL BUILD AGAIN TUE NIGHT AND WED AS LOW PRESSURE
MOVES ACROSS THE AREA AND A SMALL CRAFT ADVISORY MAY BE REQUIRED FOR
PORTIONS OF THE WATERS ONCE AGAIN.

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST
SATURDAY FOR AMZ250-252.

SYNOPSIS...JDW
NEAR TERM...MJC/TRA
SHORT TERM...JDW
LONG TERM...RJD
AVIATION...43

AREA FORECAST DISCUSSION

NWS BISMARCK ND

303 PM CST THU FEB 7 2013

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

THE MAIN CHALLENGE FOR THE SHORT TERM IS FOG AND STRATUS LATE THIS
AFTERNOON INTO FRIDAY.

THUS FAR TODAY...THE HRRR AND RAP HAVE CAPTURED THE STRATUS THE
BEST ACROSS WESTERN AND CENTRAL NORTH DAKOTA...AND WILL FOLLOW
THEIR SOLUTIONS WHICH KEEP THE STRATUS NEARLY INTACT THROUGH THE
NIGHT. GIVEN WEAK MIXING...NO AIRMASS EXCHANGE AND WEAK LOW LEVEL
WARM AIR ADVECTION REINFORCING THE INVERSION THAT IS TRAPPING THE
MOISTURE...ALSO KEPT THE STRATUS IN PLACE THROUGH MUCH OF THE DAY
ON FRIDAY FOR THE CENTRAL AND INTO THE FAR NORTHWEST. DID ISSUE A
DENSE FOG ADVISORY FOR NORTHWEST NORTH DAKOTA EARLIER THIS
AFTERNOON WHICH RUNS THROUGH 03 UTC THIS EVENING. WHILE
VISIBILITIES HAVE INCREASED ABOVE ONE QUARTER OF A MILE...WILL
KEEP THE ADVISORY IN PLACE AS VISIBILITIES ARE EXPECTED TO TREND
DOWN ONCE AGAIN AFTER SUNSET. DID EXPAND THE MENTION OF FOG
THROUGH THE SOUTH CENTRAL INTO FRIDAY MORNING ALONG THE COOL SIDE
OF THE BOUNDARY THAT WAS LOCATED FROM NORTHEAST MONTANA TO
APPROXIMATELY MOBRIDGE. GIVEN THE LACK OF ICE CRYSTALS IN THE
COLUMN AND SATURATION WARMER THAN -10 C...ALSO ADDED PATCHY LIGHT
FREEZING DRIZZLE TO THE AREAS EXPECTED TO BE IMPACTED BY FOG. THE
QUESTION IS WHETHER OR NOT THE DENSE FOG ADVISORY WILL NEED TO
EXPANDED IN TIME AND/OR AREA LATER THIS EVENING. THE UNCERTAINTY
IS IN INCREASING LOW LEVEL MIXING POST 06 UTC WHICH MAY HELP TO
KEEP VISIBILITIES ABOVE ONE QUARTER OF A MILE...BUT...WILL MONITOR
TRENDS THROUGH THE EVENING.

AS STATED ABOVE...DID KEEP THE STRATUS ACROSS MUCH OF CENTRAL AND
INTO THE NORTHWEST THROUGH MUCH OF FRIDAY...AND BEGAN CLEARING
FROM THE NORTHWEST THROUGH THE JAMES RIVER VALLEY LATE IN THE
AFTERNOON AND INTO THE EVENING AS WEAK HIGH PRESSURE BUILDS ACROSS
THE AREA. THAT SAID...FLOW WILL BE WEAK AND WOULD NOT BE SURPRISED
IF THE STRATUS DOES LINGER INTO SATURDAY NIGHT. THUS...DO NOT
HAVE A LOT OF CONFIDENCE IN THE GUIDANCE SUITE OUTSIDE OF THE
HRRR/RAP AS IT HAS NOT HANDLED THE STRATUS WELL THIS AFTERNOON.

.LONG TERM...

LONG TERM...SATURDAY THROUGH NEXT THURSDAY...

THE MAIN FORECAST CONCERN FOR THE PERIOD WILL BE THE SNOW AND
BLOWING SNOW CHANCES SATURDAY NIGHT THROUGH SUNDAY NIGHT.

FOR DAYTIME SATURDAY...DRY CONDITIONS ARE EXPECTED AS HIGH PRESSURE
PUSHES EAST ACROSS THE CWA WITH THE DEVELOPING STORM SYSTEM OVER THE
SOUTHERN PLAINS. TEMPERATURES ARE FORECAST TO BE NEAR TO SLIGHTLY
ABOVE NORMAL READINGS...FROM THE 20S NORTH TO LOWER 30S SOUTHWEST.

FOR SATURDAY NIGHT THROUGH MONDAY...

THE MODELS CONTINUE TO COME INTO BETTER AGREEMENT WITH RESPECT TO A
LARGE UPPER LEVEL TROUGH AND ATTENDANT SOUTHERN STREAM SURFACE LOW
PRESSURE SYSTEM FORECAST TO IMPACT THE REGION FOR THE LATTER HALF OF
THIS WEEKEND. THE MODELS DEVELOP THE SURFACE LOW NORTHEASTWARD FROM
COLORADO/KANSAS SATURDAY AFTERNOON TO EASTERN NEBRASKA/KANSAS BY
SUNDAY MORNING WITH AN INVERTED TROUGH EXTENDING NORTHEASTWARD
ACROSS THE RED RIVER VALLEY. AT THIS TIME IT APPEARS THAT THE
LEADING EDGE OF THE SNOW FROM THE SYSTEM WOULD REACH SOUTHEASTERN
AND PARTS OF SOUTH CENTRAL NORTH DAKOTA - FROM THE RED RIVER VALLEY
TO THE JAMES RIVER VALLEY IN NORTH DAKOTA TO ROUGHLY SIOUX COUNTY -
LATE SATURDAY NIGHT.

THE MODELS CONTINUE TO DEPICT THE STORM SYSTEM CENTER
DEVELOPING/MOVING TO IOWA/SOUTHERN MINNESOTA BY SUNDAY EVENING...AND
REACHING WISCONSIN AND LAKE SUPERIOR BY MONDAY MORNING. THE MODELS
DEPICT A TROWAL FEATURE WITH THIS SYSTEM AFFECTING MINNESOTA AND THE
EASTERN DAKOTAS SUNDAY AND SUNDAY NIGHT. THE LARGE CLOUD AND
MOISTURE SHIELD ASSOCIATED WITH THIS TROWAL WOULD CONTINUE TO AFFECT
THE EASTERN HALF OF THE STATE...ROUGHLY FROM MINOT/BISMARCK
EASTWARD...THROUGH SUNDAY EVENING...WITH THE TROWAL FEATURE MOVING
EASTWARD ON MONDAY MORNING. THUS SNOW AND BLOWING SNOW WILL IMPACT
CENTRAL NORTH DAKOTA ALL DAY SUNDAY THROUGH MONDAY MORNING.

IN CENTRAL AND WESTERN NORTH DAKOTA: MODERATE TO HEAVY SNOWFALL
AMOUNTS FROM THIS SCENARIO WOULD IMPACT THE JAMES RIVER BASIN THE
MOST...WITH LIGHT SNOW AMOUNTS ALONG A BISMARCK/MINOT LINE.
TEMPERATURES ARE NOT EXPECTED TO BE SUBZERO THROUGH THIS
PERIOD...WITH HIGHS SUNDAY MAINLY IN THE 20S AND IN THE TEENS AND
20S MONDAY. LOWS SHOULD BE ZERO TO 15 ABOVE.

THE STORM SYSTEM CONTINUES MOVING EAST AND EXITS THE REGION MONDAY
NIGHT. A WESTERN SHORTWAVE RIDGE BUILDS BACK INTO THE DAKOTAS
TUESDAY/WEDNESDAY KEEPING THE FORECAST AREA DRY. A WARM-UP WITH
HIGHS IN THE 20S AND 30S TUESDAY THROUGH THURSDAY.

ON THURSDAY AN UPPER LEVEL SHORTWAVE TROUGH WITH A CLIPPER-TYPE LOW
IS PROGGED TO APPROACH NORTH DAKOTA. MODELS ARE DIFFERING ON TIMING
OF THAT FEATURE...SO HAVE KEPT THE THURSDAY DAYTIME FORECAST DRY FOR
NOW.

.AVIATION...

WIDESPREAD IFR/MVFR CONDITIONS IN STRATUS AND FOG ACROSS WESTERN AND
CENTRAL NORTH DAKOTA WITH EMBEDDED LIFR CONDITIONS AND PATCHY
FREEZING DRIZZLE WILL CONTINUE FOR ALL TAF SITES EXCEPT KDIK...WHICH
REMAINS CLEAR AND JUST SOUTH AND WEST OF THE STRATUS DECK.
HOWEVER...THE STRATUS IS EXPECTED TO BUILD BACK IN LATE THIS EVENING
INTO TONIGHT. THE MODELS ARE SUGGESTING A BRIEF PERIOD THIS EVENING
OF IMPROVING CONDITIONS TO MVFR/VFR...HOWEVER THE STRATUS SHOULD
ENCOMPASS THE STATE AFT 06Z.

.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 PM CST THIS EVENING FOR NDZ001-002-
009-010-017-018.

SHORT TERM...AYD
LONG TERM/AVIATION...AYD

AREA FORECAST DISCUSSION

NWS BISMARCK ND

1033 AM CST THU FEB 7 2013

.DISCUSSION...

THE MAIN CHANGE WITH THIS FORECAST UPDATE WAS TO REMOVE THE
MENTION OF FOG ACROSS THE NORTH CENTRAL THROUGH THE UPPER PORTIONS
OF THE JAMES RIVER VALLEY BASED UPON OBSERVED TRENDS THROUGH 1630
UTC. ALSO...MAINTAINED THE STRATUS ACROSS MUCH CENTRAL AND INTO
NORTHWEST NORTH DAKOTA THROUGH THE EVENING...AND MAY HAVE TO
EXTEND IT THROUGH TOMORROW AS LITTLE MIXING...THE LACK OF AN
AIRMASS EXCHANGE AND LOW LEVEL WARM AIR ADVECTION THROUGH THE
NIGHT ALL SUGGEST THE POTENTIAL FOR THE STRATUS TO REMAIN IN
PLACE. THIS IS SUPPORTED BY THE 12 UTC NAM/GFS BUFR SOUNDINGS AND
THE LATEST RAP RUNS.

.AVIATION...

IFR/LIFR CONDITIONS ARE EXPECTED TO CONTINUE ACROSS
WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING. CONDITIONS WILL BE
SLOW TO IMPROVE FROM WEST TO EAST THIS AFTERNOON.
HOWEVER...MVFR/VFR CONDITIONS ARE EXPECTED TO DEVELOP FROM
KISN/KDIK LATER THIS AFTERNOON WITH MVFR/VFR CONDITIONS EXPECTED
ACROSS KMOT/KBIS/KJMS BY THIS EVENING.

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...AYD
AVIATION...JV

AREA FORECAST DISCUSSION

NWS NORMAN OK

945 PM CST FRI FEB 8 2013

.UPDATE...
VERY FEW CHANGES WERE MADE TO THE ONGOING FORECAST. WITH
INCREASING LOW/MID LEVEL MOISTURE OVERNIGHT...EXPECT CLOUD COVER
TO CONTINUE TO EXPAND AND LOWER. RECENT HRRR RUNS DEPICT AREA OF
VERY LIGHT SHOWERS/DRIZZLE MAY DEVELOP AROUND 09Z AND MOVE INTO TX
AND SW OK ZONES BY AROUND 10Z TO 12Z. THEREFORE..INTRODUCED
MENTION OF DRIZZLE IN WX GRIDS. OTHERWISE...ONLY MADE MINOR TWEAKS
TO HOURLY TEMPS/DEWPOINTS/WINDS TO REFLECT RECENT TRENDS. EXPECT
MOISTURE TO CONTINUE TO RETURN NWD...MAKING FOR A VERY CLOUDY DAY
TOMORROW. INTERMITTENT SHOWERS WILL BE LIKELY BEGINNING AROUND
MIDDAY TOMORROW...LASTING INTO THE EVENING BEFORE A LINE OF STORMS
MOVES ACROSS THE AREA.

.PREV DISCUSSION... /ISSUED 646 PM CST FRI FEB 8 2013/

AVIATION...
LOW CEILINGS ARE EXPECTED EARLY SATURDAY WHEN SOUTH WINDS INCREASE
AND BRING MOISTURE NORTH. AREAS OF LIGHT RAIN ARE POSSIBLE
SATURDAY AFTERNOON BEFORE THUNDERSTORMS IN THE EVENING WITH THE
PASSAGE OF A DRYLINE FROM THE WEST.

PREV DISCUSSION... /ISSUED 221 PM CST FRI FEB 8 2013/

DISCUSSION...
WITH WINDS SHIFTING TO THE SOUTH AND SOUTHEAST MOISTURE WILL BEGIN
TO MOVE BACK INTO THE AREA TONIGHT/SATURDAY AHEAD OF A STORM SYSTEM
CURRENTLY OVER THE WESTERN U.S. THE UPPER LOW WILL MOVE ACROSS THE
SOUTHERN AND CENTRAL ROCKIES INTO THE CENTRAL PLAINS THIS WEEKEND
CAUSING SHOWERS AND THUNDERSTORMS ACROSS PARTS OF THE AREA STARTING
SATURDAY AND CONTINUING THROUGH SUNDAY MORNING. THE MOST LIKELY TIME
WILL BE SATURDAY EVENING INTO SUNDAY MORNING. A DRYLINE/PACIFIC COLD
FRONT WILL MOVE ACROSS THE REGION DURING THIS TIME PERIOD BRINGING
DRIER AIR TO THE REGION. SOME OF THE STORMS COULD BECOME SEVERE WITH
LARGE HAIL AND STRONG WINDS THE MAIN CONCERN.

IN ADDITION TO THE SHOWERS/STORMS THIS WEEKEND... STRONG WINDS ARE
EXPECTED TO DEVELOP SATURDAY AS THE PRESSURE GRADIENT STRENGTHENS.
WIND SPEEDS IN SOME AREAS MAY APPROACH WIND ADVISORY CRITERIA.
HOWEVER... CURRENT THOUGHTS ARE THAT WINDS WILL REMAIN JUST BELOW
CRITERIA SO WILL HOLD OFF ON ANY WIND ADVISORY FOR NOW AND LET LATER
SHIFTS EVALUATE. THEN ON SUNDAY... WITH THE DRIER AIR MOVING INTO
THE REGION... WILDFIRE POTENTIAL WILL BE VERY HIGH BUT IS EXPECTED
TO REMAIN BELOW RED FLAG CRITERIA.

AFTER THE WEEKEND... MODELS SHOW ANOTHER STORM SYSTEM AFFECTING THE
AREA EARLY NEXT WEEK. LIGHT RAIN AND SNOW WILL BE POSSIBLE WITH THIS
SYSTEM MONDAY NIGHT THROUGH TUESDAY NIGHT. MODELS THEN SHOW A THIRD
SYSTEM COULD AFFECT THE REGION LATE NEXT WEEK.

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 37 54 46 63 / 10 40 80 10
HOBART OK 36 56 40 63 / 10 50 60 10
WICHITA FALLS TX 39 60 45 66 / 10 50 80 10
GAGE OK 31 55 34 57 / 10 50 50 0
PONCA CITY OK 33 55 44 61 / 10 40 70 10
DURANT OK 39 59 53 70 / 10 40 90 40

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&

84/09

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

914 PM EST FRI FEB 8 2013

.SYNOPSIS...
AN INTENSIFYING STORM OFF THE NEW JERSEY COAST THIS EVENING WILL
LIFT NORTHEAST AWAY FROM THE AREA OVERNIGHT. HIGH PRESSURE WILL
BUILD INTO THE AREA BEHIND THE STORM LATER SATURDAY INTO SUNDAY.
A FRONTAL SYSTEM MOVING EAST FROM THE MIDWEST SHOULD BRING ANOTHER
PERIOD OF MIXED PRECIPITATION ON MONDAY.

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
BACK EDGE OF MODERATE SNOW IS PUSHING THRU SCHUYLKILL CO AS OF
01Z. REMNANTS OF NORTHERN STREAM SHORTWAVE...EVIDENT IN WATER
VAPOR LOOP NR BUFFALO NY THIS EVENING. OCNL LIGHTER SNOW WILL
ACCOMPANY THIS FEATURE AS IS DROPS ACROSS NORTHEAST PA OVERNIGHT.
WILL KEEP ADV GOING ACROSS OUR NE COUNTIES FROM TIOGA SOUTH THRU
SCHUYLKILL...WHERE MDL QPF SUPPORTS AN ADDITIONAL 1-2 INCHES
OVERNIGHT.

WINDS HAVE RAMPED UP MARKEDLY LATE THIS EVENING ACROSS THE CENTRAL
AND WESTERN MTNS. AS PRES GRAD TIGHTENS WEST OF DEVELOPING
COASTAL STORM...EXPECT GUSTY WINDS TO SPREAD INTO THE SUSQ VALLEY
AS WELL. BUFKIT SOUNDING DATA SUPPORTS GUSTS BTWN 35-40KTS ACROSS
SOUTHERN PA OVERNIGHT /JUST BLW ADVISORY CRITERIA/ AND ARND 30KTS
ACROSS NORTHERN PA.

TEMPS HAVE ALREADY PLUMMETED TO ARND 20F ACROSS THE W MTNS AT 01Z
AND EXPECT THE COMBINATION OF GUSTY WINDS AND READINGS FALLING TO
THE LTEENS TO RESULT IN WIND CHILLS ARND ZERO ACROSS THE W MTNS
LATE TONIGHT. FURTHER EAST...A BLEND OF LATEST LAMP AND RUC DATA
INDICATES OVERNIGHT LOWS IN THE UTEENS TO L20S.

.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
THE TIGHT P-GRADIENT IN THE WAKE OF THE DEPARTING INTENSE LOW WILL
HELP TO CREATE A STRONG NWRLY LLVL WIND MAX ON SAT. VERTICAL
MIXING OF UP TO JUST AROUND 2 KFT AGL WILL EASILY TAP 25-30 KT
WINDS AND TRANSPORT THEM TO THE SFC IN FREQUENT GUSTS...ESP ACROSS
EASTERN PA.

LG SCALE SUBSIDENCE IN WAKE OF DEPARTING OCEAN STORM AND
DOWNSLOPING FLOW OFF OF THE ALLEGHENIES SHOULD RESULT IN PLENTY OF
SUN ACROSS THE LOWER SUSQ VALLEY ON SAT. ACROSS NORTHERN AND
WESTERN PA...PLENTY OF STRATOCU SHOULD PERSIST INTO THE MID
AFTERNOON AS A WELL DEFINED 850-500 THERMAL TROUGH CROSSES THE
REGION. THE CLOUDS WILL GRADUALLY ERODE FROM SE TO NW LATE IN THE
AFTERNOON...AS INVERSION HGTS FALL UPON APPROACH OF HIGH PRES. MDL
900MB TEMPS ARE SUPPORTIVE OF HIGH TEMPS RANGING FROM THE L20S
OVER THE HIGHEST TERRAIN OF THE NORTH...TO THE M30S ACROSS THE
LOWER SUSQ VALLEY. HOWEVER...THE GUSTY WINDS WILL MAKE IT FEEL
CONSIDERABLY COLDER.

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
GRADUALLY DIMINISHING WINDS AND CLEARING SKIES WILL FOLLOW FOR
SAT NIGHT AS HIGH PRESSURE BUILDS EAST OVER THE STATE. MINS
SATURDAY NIGHT WILL BE A TAD BELOW GUIDANCE VALUES BASED ON PRIME
CONDITIONS FOR RADIATIONAL COOLING...IN THE FORM OF A CALM WIND...
CLEAR SKY AND FRESH SNOW COVER OVR PARTS OF THE AREA. TEMPS LATE
SAT NIGHT COULD DIP TO NEAR ZERO THROUGHOUT THE PERENNIAL COLD
SPOTS OVER THE NRN MTNS...AND IN THE TEENS ACROSS THE SOUTHERN
HALF OF CWA.

SUNDAY WILL FEATURE SUNSHINE...MIXING WITH SOME MID AND HIGH CLOUDS
MOVING IN FROM THE WEST DURING THE AFTERNOON. THE VERY COLD START
AND GRADUAL INCREASE IN THE CLOUD COVER IN THE AFTERNOON WILL KEEP
TEMPS NEAR NORMAL /IN THE MID-UPPER 30S/ THROUGHOUT THE CENTRAL AND
ERN ZONES. INCREASING SOUTHERLY FLOW IN THE AFTERNOON ACROSS THE
WESTERN HIGH TERRAIN WILL ALLOW FOR MAXS REACHING THE U30S TO AROUND
40F...OR 5-8F ABOVE NORMAL.

LITTLE SPREAD AMONG MED RANGE MDL GUIDANCE THRU EARLY NEXT
WEEK...ALL OF WHICH TRACKS NEXT LOW PRES SYS WEST AND JUST NORTH OF
PA LATE SUN NIGHT INTO MONDAY. DEPENDING ON TIMING...AND GIVEN THE
MARGINAL LLVL TEMP PROFILE...ANY LIGHT PRECIP ARRIVING EARLY
MONDAY MORNING COULD BE IN THE FORM OF FZRA. SFC TEMPS IN THE 20S TO
LOWER 30S WILL BE COLD ENOUGH FOR ICY CONDS EARLY MONDAY /ESP IF
PRECIP REACHES THE NORTHEAST PORTION OF CWA BETWEEN 06-12Z/ BEFORE
A CHANGEOVER TO PLAIN RAIN FROM SW TO NE BY 14-16Z.

SLIGHTLY COOLER AIR WILL MOVE BACK INTO THE REGION FOR TUESDAY
AND WEDNESDAY WITH SCATTERED LIGHT RAIN/SNOW SHOWERS ACROSS MAINLY
THE NW MTNS.

MINOR HEIGHT/THICKNESS RISES IN THE WAKE OF A HIGH PRESSURE RIDGE
LATER IN THE WEEK WILL LIKELY BE FOLLOWED BY A RATHER POTENT NRN
STREAM SHORTWAVE/CLIPPER TYPE SYSTEM FOR FRIDAY INTO SATURDAY WITH A
CHANCE OF SNOW SHOWERS.

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
00Z TAFS SENT.

SOME UPDATES DONE SINCE THEN. ANOTHER SET WILL BE SENT BY
10 PM.

BACK EDGE OF THE HEAVIER SNOW HAS BEEN BUILDING BACK TO THE WEST
AND SOUTH THE LAST FEW HOURS. EXPECT THIS TREND TO CONTINUE THE
NEXT FEW HOURS...AS COASTAL STORM BOMBS OUT. STRONG WINDS HAVE
DEVELOP ACROSS WESTERN AND CENTRAL AREAS...AND WILL WORK INTO
EASTERN AREAS THE NEXT FEW HOURS. WIND GUST TO 40 MPH LIKELY.

MVFR AND IFR CONDITIONS WILL GIVE WAY TO VFR DURING THE MORNING
HOURS ON SAT.

GUSTY WINDS WILL CONTINUE INTO THE EARLY AFTERNOON HOURS.

OVERALL NOT A BAD SATURDAY AFTERNOON AND SUNDAY...AS VFR
CONDITIONS PREVAIL.

OUTLOOK...
SUN...VFR NO SIG WX.
MON...AM WINTRY MIX TO RAIN. FROPA. -SHSN WEST LATE.
TUE...MAINLY VFR...MVFR -SHSN PSBL NW.
WED...ANOTHER WINTER STORM POSSIBLE.

.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM EST SATURDAY FOR PAZ037-042-
053-058.

$$
SYNOPSIS...DEVOIR
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...RXR
AVIATION...MARTIN

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

821 PM EST FRI FEB 8 2013

.SYNOPSIS...
AN INTENSIFYING STORM OFF THE NEW JERSEY COAST THIS EVENING WILL
LIFT NORTHEAST AWAY FROM THE AREA OVERNIGHT. HIGH PRESSURE WILL
BUILD INTO THE AREA BEHIND THE STORM LATER SATURDAY INTO SUNDAY. A
FRONTAL SYSTEM MOVING EAST FROM THE MIDWEST SHOULD BRING ANOTHER
PERIOD OF MIXED PRECIPITATION ON MONDAY.

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
BACK EDGE OF MODERATE SNOW IS PUSHING THRU SCHUYLKILL CO AS OF
01Z. REMNANTS OF NORTHERN STREAM SHORTWAVE...EVIDENT IN WATER
VAPOR LOOP NR BUFFALO NY THIS EVENING. OCNL LIGHTER SNOW WILL
ACCOMPANY THIS FEATURE AS IS DROPS ACROSS NORTHEAST PA OVERNIGHT. WILL
KEEP ADV GOING ACROSS OUR NE COUNTIES FROM TIOGA SOUTH THRU
SCHUYLKILL...WHERE MDL QPF SUPPORTS AN ADDITIONAL 1-2 INCHES
OVERNIGHT.

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
GRADUALLY DIMINISHING WINDS AND CLEARING SKIES WILL FOLLOW FOR
SAT NIGHT AS HIGH PRESSURE BUILDS EAST OVER THE STATE. MINS
SATURDAY NIGHT WILL BE A TAD BELOW GUIDANCE VALUES BASED ON PRIME
CONDITIONS FOR RADIATIONAL COOLING...IN THE FORM OF A CALM WIND...CLEAR
SKY AND FRESH SNOW COVER OVR PARTS OF THE AREA. TEMPS LATE SAT
NIGHT COULD DIP TO NEAR ZERO THROUGHOUT THE PERENNIAL COLD SPOTS
OVER THE NRN MTNS...AND IN THE TEENS ACROSS THE SOUTHERN HALF OF
CWA.

SLIGHTLY COOLER AIR WILL MOVE BACK INTO THE REGION FOR TUESDAY
AND WEDNESDAY WITH SCATTERED LIGHT RAIN/SNOW SHOWERS ACROSS MAINLY
THE NW MTNS.

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
BACK EDGE OF THE STEADY MODERATE SNOW JUST EAST OF THE OFFICE.
WHILE THIS AREA IS SEPERATE FROM THE PCPN WITH THE COASTAL STORM...
STILL EXPECT THIS BACK EDGE TO SLOW THIS EVENING. FAR WESTERN
AREAS LIKE JST AND BFD SEEING SOME LIGHTER SNOW...AS WINDS ARE
NOW SHIFTING TO THE NW THERE. MAIN ISSUE WILL BE THE GUSTY WINDS
LATER THIS EVENING...AS THE COASTAL LOW BECOMES A MAJOR STORM
SYSTEM OFF THE COAST. SOME CHANGES MADE TO 21Z TAFS.

GUST WNW WINDS WITH SOME GUSTS TO 35 KTS POSSIBLE LATER TONIGHT.
MVFR CIGS AND SCT -SHSN PREVAIL ACROSS WESTERN AND NORTHERN
SECTIONS SATURDAY WITH VFR TO LCL MVFR CIGS CENTRAL AND SOUTH
CENTRAL. BECOMING MAINLY VFR EAST.

OUTLOOK...
SUN...VFR NO SIG WX.
MON...AM WINTRY MIX TO RAIN. FROPA. -SHSN WEST LATE.
TUE...MAINLY VFR...MVFR -SHSN PSBL NW.
WED...ANOTHER WINTER STORM POSSIBLE.

.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM EST SATURDAY FOR PAZ037-042-
053-058.

$$
SYNOPSIS...DEVOIR/FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...RXR
AVIATION...DEVOIR/MARTIN/RXR

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

448 PM EST THU FEB 7 2013

.SYNOPSIS...
CLOUDS WILL INCREASE AND THICKEN TONIGHT AS A STORM SYSTEM
CONTINUES TO ORGANIZE FROM THE MIDWEST TO THE SOUTHEAST AND MID
ATLANTIC COAST. LIGHT MIXED PRECIPITATION WILL DEVELOP EARLY
FRIDAY MORNING IN THE SOUTHEAST UPSLOPE FLOW OVER CENTRAL
PENNSYLVANIA. A PERIOD OF MODERATE TO HEAVY SNOW IS EXPECTED TO
CROSS MUCH OF CENTRAL PENNSYLVANIA FRIDAY AFTERNOON AND EVENING
PRODUCING A FEW TO SEVERAL INCHES OF ACCUMULATION. HIGHEST
AMOUNTS WILL BE ACROSS THE NORTHERN AND ENDLESS MOUNTAIN REGIONS
WHERE UP TO 8 INCHES OF SNOW MAY FALL BY EARLY SATURDAY MORNING.
HIGH PRESSURE WILL BUILD IN BEHIND THE STORM ON SATURDAY AND SUNDAY.
A LOW PRESSURE SYSTEM SHOULD BRING ANOTHER PERIOD OF MIXED
PRECIPITATION ON MONDAY.

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
CLOUDS INCREASE AND THICKEN TONIGHT AS THE ESE FLOW AROUND STRONG
QUEBEC HIGH PRESSURE AND DEVELOPING SOUTHEAST COASTAL LOW
INTENSIFIES. SPOTTY LIGHT SNOW OR FREEZING DRIZZLE MAY DEVELOP IN
THE PRE DAWN HOURS AS SUGGESTED BY THE RAP AND EVEN GFS...BUT
THINK THE THREAT IS GREATEST AFT 12Z WHEN MOISTURE FLUX BECOMES
MORE SIGNIFICANT. MINS SHOULD RANGE THROUGH THE 20S.

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
THIS MORNING`S SREF AND DETERMINISTIC NAM/GFS WARRANTED SOME
RAMPING UP OF QPF ACROSS CENTRAL AND NORTHERN PA. WHILE MODELS
KEEP NORTHERN AND SOUTHERN STREAM DISTURBANCES FROM PHASING IN
TIME TO PRODUCE AN EPIC STORM FOR PA...FRIDAY AFTERNOON AND
EVENING IMPACT WILL BE RELATIVELY HIGH WITH A 4 TO 6 HOUR PERIOD
OF MODERATE TO HEAVY SNOW AS THE STRONG AXIS OF DEFORMATION AHEAD
OF THE NORTHERN STREAM CENTER PROPAGATES EASTWARD. GIVEN THE
LIKELY IMPACT BUT STILL REASONABLE UNCERTAINTY...OPTED FOR A
WARNING WITH A WIDER RANGE (4 TO 8) REACHING THE 6 INCH MIDPOINT
CRITERIA FOR WARNINGS FROM WARREN COUNTY EASTWARD AND
SOUTHEASTWARD THROUGH POTTER...SULLIVAN COLUMBIA AND SCHUYLKILL
COUNTIES...INCLUDING LYCOMING COUNTY AND THE WILLIAMSPORT AREA.

FARTHER SOUTH...THE PERIOD OF LIGHT MIXED PRECIPITATION DURING THE
MORNING COMBINED WITH THE LATER AFTERNOON AND EVENING PERIOD OF
ACCUMULATING SNOW GARNERED AN ADVISORY FOR THE REMAINDER OF
CENTRAL PA. FAR SOUTHEAST COUNTIES (LANCASTER AND YORK) MAY BE
PLAIN RAIN FOR A WHILE...BUT A LATE AFTERNOON/EVENING PERIOD OF
SNOWFALL WITH 1 TO 3 INCHES OF SNOW IS LIKELY. LANCASTER COUNTY
MAY BE SUSCEPTIBLE TO A SLIGHTLY LONGER PERIOD OF ACCUMULATING
SNOW AS THE DEFORMATION AXIS STALLS FRIDAY NIGHT WHILE THE COASTAL
LOW STRENGTHENS.

HEADLINES ARE WELL COLLABORATED WITH OUR NORTHERN AND EASTERN
NEIGHBORS...BUT MAY BE ON THE PESSIMISTIC SIDE GIVEN THE IMPACT OF
AN AFTERNOON AND EVENING BURST OF SNOW. MEAN QPFS IN THE WARNING
AREAS RANGE FROM 0.4 TO 0.7 RANGE FROM THE NORTHERN TIER TO THE
LOWER SUSQ. RIVER VALLEY AS PER DETERMINISTIC RUNS...WITH PLUMES
GIVING HIGHER CONFIDENCE TO HIGH ADVISORY AMOUNTS OR APPROACHING
WARNING AMOUNTS FOR A GOOD PART OF NORTHERN AND EAST CENTRAL
AREAS. THE SNOW COULD LINGER INTO SATURDAY MORNING ACROSS FAR
NORTHEASTERN AREAS.

.LONG TERM /SATURDAY THROUGH THURSDAY/...
A WINDY AND COLDER DAY IS EXPECTED SATURDAY...AS INTENSE COASTAL
LOW PASSES OUT TO SEA. SCT -SHSN/FLURRIES COULD BE POSSIBLE ACROSS
THE W MTNS EARLY SAT. HOWEVER...RAPIDLY FALLING INVERSION HGTS
WITH APPROACH OF SFC HIGH SHOULD CAUSE THEM TO TAPER OFF BY MIDDAY
AND KEEP ANY ADDITIONAL ACCUMS NEGLIGIBLE. MDL SOUNDINGS...WHICH
ARE WELL MIXED TO ARND 900MB...SUPPORT CONTINUED NWRLY GUSTS BTWN
20-30KTS...WITH THE HIGHEST WINDS ACROSS EASTERN PA. LG SCALE
SUBSIDENCE SHOULD PRODUCE MSUNNY SKIES ACROSS THE SUSQ VALLEY
SATURDAY...WHILE UPSLOPING FLOW BRINGS A GOOD DEAL OF STRATOCU TO
THE W MTNS...ESP EARLY. MIXING MDL 900MB TEMPS TO THE SFC YIELDS
HIGHS FROM THE M20S OVR THE ALLEGHENIES...TO THE M30S ACROSS THE
LOWER SUSQ VALLEY.

DIMINISHING WINDS AND CLEAR SKIES EXPECTED SAT NIGHT AS HIGH
PRESSURE BUILDS OVR THE STATE. HAVE LOWERED MINS A BIT BLW
GUIDANCE BASED ON SUCH FAVORABLE CONDS FOR RADIATIONAL COOLING.
ALTHOUGH THE AIR MASS IS NOT EXPECTED TO BE ESP COLD...FRESH SNOW
COVER COULD ALLOW READINGS TO MAKE A RUN AT ZERO OVR THE N MTNS.

LITTLE SPREAD AMONG MED RANGE MDL GUIDANCE THRU EARLY NEXT
WEEK...ALL OF WHICH TRACKS NEXT LOW PRES SYS WEST OF PA LATE SUN
NIGHT INTO MONDAY. DEPENDING ON TIMING...AND GIVEN THE SFC
TEMPS...IF PRECIP GETS IN EARLY ENOUGH...THERE COULD BE FZRA AND SFC
TEMPS SHOULD BE COLD ENOUGH FOR ICY CONDS EARLY MONDAY BEFORE A
CHANGE TO SHRA. THERE LOOKS TO BE A FINGER OF 850MB AIR FROM A LOW
LEVEL JET ASSOCIATED WITH THIS SYSTEM THAT COULD BRING IN SOME WAA
IN THE MID LEVEL THAT WOULD BRING THE MIXED PRECIPITATION EARLY.
LOOK FOR A WARM UP ON MONDAY INTO TUESDAY...BEFORE TEMPERATURES
DROP BACK DOWN TO MORE SEASONAL NORMS LATER IN THE WEEK.

AFTER MONDAY...ECMWF ENSEMBLE MEAN PATTERN FAVORS DRY AND SEASONABLE
CONDS THRU MIDWEEK WITH A SFC RIDGE BUILDING INTO THE STATE. THE
NEXT LOW LOOKS TO TRACK THROUGH THE GREAT LAKES REGION AND INTO
THE NE BY PASSING PA AS A RIDGE BUILDS OVER THE AREA.

.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
MINOR ADJUSTMENTS MADE TO THE 21Z TAFS.

EARLIER DISCUSSION BELOW.

VFR CONDITIONS THIS EVENING BEFORE FLYING CONDITIONS GO DOWNHILL
LATER TONIGHT AND FRIDAY MORNING. MIXED PRECIPITATION AND MVFR/LCL
IFR CIGS WILL DEVELOP FRIDAY MORNING AND CONTINUE INTO EARLY
AFTERNOON. AN AREA OF MODERATE TO HEAVY SNOW WILL PROPOGATE
EASTWARD DURING THE MID TO LATE AFTERNOON AND EVENING...BRINGING
IFR TO LCL LIFR CONDS ESP CENTRAL AND NORTH...WITH A PERIOD OF IFR
AND LCL LIFR CONDS POSSIBLE ACROSS THE SOUTH FRI EVENING. CONDS
WILL IMPROVE TO MVFR EARLY SAT MORNING AS COASTAL LOW PRESSURE
MOVES AWAY. SCT -SHSN EXPECTED IN THE SNOWBELT REGION THROUGH SAT
AFTN BEFORE DISSIPATING LATE IN THE DAY.

OUTLOOK...
SAT...MVFR/IFR EARLY BCMG MVFR/VFR. SNOW ENDING WEST TO EAST.
STRONG N WINDS.
SUN...VFR NO SIG WX.
MON...AM WINTRY MIX TO RAIN. FROPA. -SHSN WEST LATE.
TUE...MAINLY VFR...BUT MVFR PSBL NW EARLY WITH -SHSN.

.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 7 AM FRIDAY TO 7 AM EST SATURDAY FOR
PAZ004>006-037-041-042-046-051>053-058.
WINTER WEATHER ADVISORY FROM 7 AM FRIDAY TO 7 AM EST SATURDAY
FOR PAZ010>012-017>019-024>028-033>036-045-049-050-056-057-059-
063>066.

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/CERU
AVIATION...DEVOIR/MARTIN/STEINBUGL

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

419 PM EST THU FEB 7 2013

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...

THIS MORNING`S SREF AND DETERMINISTIC NAM/GFS WARRANTED SOME
RAMPING UP OF QPF ACROSS CENTRAL AND NORTHERN PA. WHILE MODELS
KEEP NORTHERN AND SOUTHERN STREAM DISTURBANCES FROM PHASING IN
TIME TO PRODUCE AN EPIC STORM FOR PA...FRIDAY AFTERNOON AND
EVENING IMPACT WILL BE RELATIVELY HIGH WITH A 4 TO 6 HOUR PERIOD
OF MODERATE TO HEAVY SNOW AS THE STRONG AXIS OF DEFORMATION AHEAD
OF THE NORTHERN STREAM CENTER PROPAGATES EASTWARD. GIVEN THE
LIKELY IMPACT BUT STILL REASONABLE UNCERTAINTY...OPTED FOR A
WARNING WITH A WIDER RANGE (4 TO 8) REACHING THE 6 INCH MIDPOINT
CRITERIA FOR WARNINGS FROM WARREN COUNTY EASTWARD AND
SOUTHEASTWARD THROUGH POTTER...SULLIVAN COLUMBIA AND SCHUYLKILL
COUNTIES...INCLUDING LYCOMING COUNTY AND THE WILLIAMSPORT AREA.

.LONG TERM /SATURDAY THROUGH THURSDAY/...

A WINDY AND COLDER DAY IS EXPECTED SATURDAY...AS INTENSE COASTAL
LOW PASSES OUT TO SEA. SCT -SHSN/FLURRIES COULD BE POSSIBLE ACROSS
THE W MTNS EARLY SAT. HOWEVER...RAPIDLY FALLING INVERSION HGTS
WITH APPROACH OF SFC HIGH SHOULD CAUSE THEM TO TAPER OFF BY MIDDAY
AND KEEP ANY ADDITIONAL ACCUMS NEGLIGIBLE. MDL SOUNDINGS...WHICH
ARE WELL MIXED TO ARND 900MB...SUPPORT CONTINUED NWRLY GUSTS BTWN
20-30KTS...WITH THE HIGHEST WINDS ACROSS EASTERN PA. LG SCALE
SUBSIDENCE SHOULD PRODUCE MSUNNY SKIES ACROSS THE SUSQ VALLEY
SATURDAY...WHILE UPSLOPING FLOW BRINGS A GOOD DEAL OF STRATOCU TO
THE W MTNS...ESP EARLY. MIXING MDL 900MB TEMPS TO THE SFC YIELDS
HIGHS FROM THE M20S OVR THE ALLEGHENIES...TO THE M30S ACROSS THE
LOWER SUSQ VALLEY.

AFTER MONDAY...ECMWF ENSEMBLE MEAN PATTERN FAVORS DRY AND SEASONABLE CONDS
THRU MIDWEEK WITH A SFC RIDGE BUILDING INTO THE STATE.
THE NEXT LOW LOOKS TO TRACK THROUGH THE GREAT LAKES REGION AND
INTO THE NE BY PASSING PA AS A RIDGE BUILDS OVER THE AREA.

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS THIS EVENING BEFORE FLYING CONDITIONS GO DOWNHILL
LATER TONIGHT AND FRIDAY MORNING. MIXED PRECIPITATION AND MVFR/LCL
IFR CIGS WILL DEVELOP FRIDAY MORNING AND CONTINUE INTO EARLY
AFTERNOON. AN AREA OF MODERATE TO HEAVY SNOW WILL PROPOGATE
EASTWARD DURING THE MID TO LATE AFTERNOON AND EVENING...BRINGING
IFR TO LCL LIFR CONDS ESP CENTRAL AND NORTH...WITH A PERIOD OF IFR
AND LCL LIFR CONDS POSSIBLE ACROSS THE SOUTH FRI EVENING. CONDS
WILL IMPROVE TO MVFR EARLY SAT MORNING AS COASTAL LOW PRESSURE
MOVES AWAY. SCT -SHSN EXPECTED IN THE SNOWBELT REGION THROUGH SAT
AFTN BEFORE DISSIPATING LATE IN THE DAY.

OUTLOOK... FRI...IFR-LIFR. AM MIXED
PRECIP SOUTH/PM SNOW. SNOW/SLEET NORTH. STRONG NNW WIND DEVELOPING
LATE.
SAT...MVFR/IFR EARLY BCMG MVFR/VFR. SNOW ENDING WEST TO
EAST. STRONG NNW WINDS EARLY.
SUN...BCMG VFR NO SIG WX.
MON...AM WINTRY MIX TO RAIN. FROPA. -SHSN WEST LATE.

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/CERU
AVIATION...DEVOIR/STEINBUGL

AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

244 PM EST THU FEB 7 2013

.NEAR TERM /THROUGH TONIGHT/...
CLOUDS INCREASE AND THICKEN TONIGHT AS THE ESE FLOW AROUND STRONG
QUEBEC HIGH PRESSURE AND DEVELOPING SOUTHEAST COASTAL LOW
INTENSIFIES. SPOTTY LIGHT SNOW OR FREEZING DRIZZLE MAY DEVELOP IN
THE PRE DAWN HOURS AS SUGGESTED BY THE RAP AND EVEN GFS...BUT
THINK THE THREAT IS GREATEST AFT 12Z WHEN MOISTURE FLUX BECOMES
MORE SIGNIFICANT. MINS SHOULD RANGE THROUGH THE 20S.

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
THIS MORNING`S SREF AND DETERMINISTIC NAM/GFS WARRANTED SOME
RAMPING UP OF QPF ACROSS CENTRAL AND NORTHERN PA. WHILE MODELS
KEEP NORTHERN AND SOUTHERN STREAM DISTURBANCES FROM PHASING IN
TIME TO PRODUCE AN EPIC STORM FOR PA...FRIDAY AFTERNOON AND
EVENING IMPACT WILL BE RELATIVELY HIGH WITH A 4 TO 6 HOUR PERIOD
OF MODERATE TO HEAVY SNOW AS THE STRONG AXIS OF DEFORMATION AHEAD
OF THE NORTHERN STREAM CENTER PROPOGATES EASTWARD. GIVEN THE
LIKELY IMPACT BUT STILL REASONABLE UNCERTAINTY...OPTED FOR A
WARNING WITH A WIDER RANGE (4 TO 8) REACHING THE 6 INCH MIDPOINT
CRITERIA FOR WARNINGS FROM WARREN COUNTY EASTWARD AND
SOUTHEASTWARD THROUGH POTTER...SULLIVAN COLUMBIA AND SCHUYLKILL
COUNTIES...INCLUDING LYCOMING COUNTY AND THE WILLIAMSPORT AREA.

LITTLE SPREAD AMONG MED RANGE MDL GUIDANCE THRU EARLY NEXT
WEEK...ALL OF WHICH TRACKS NEXT LOW PRES SYS WEST OF PA SUN NITE
AND MONDAY. IF PRECIP GETS IN EARLY ENOUGH...SFC TEMPS SHOULD BE
COLD ENOUGH FOR ICY CONDS EARLY MONDAY BEFORE A CHANGE TO SHRA.

ECMWF ENSEMBLE MEAN PATTERN FAVORS DRY AND SEASONABLE CONDS THRU
MIDWEEK WITH A SFC RIDGE BUILDING INTO THE STATE. HOWEVER...GEFS
DATA INDICATES A LESS PROGRESSIVE PATTERN WITH UPPER TROF
REMAINING WEST OF PA AND THE POTENTIAL OF WEAK DISTURBANCES RIDING
UP THE E COAST.

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS THIS EVENING BEFORE FLYING CONDITIONS GO DOWNHILL
LATER TONIGHT AND FRIDAY MORNING. MIXED PRECIPITATION AND MVFR/LCL
IFR CIGS WILL DEVELOP FRIDAY MORNING AND CONTINUE INTO EARLY
AFTERNOON. AN AREA OF MODERATE TO HEAVY SNOW WILL PROPOGATE
EASTWARD DURING THE MID TO LATE AFTERNOON AND EVENING...BRINGING
IFR TO LCL LIFR CONDS ESP CENTRAL AND NORTH...WITH A PERIOD OF IFR
AND LCL LIFR CONDS POSSIBLE ACROSS THE SOUTH FRI EVENING. CONDS
WILL IMPROVE TO MVFR EARLY SAT MORNING AS COASTAL LOW PRESSURE
MOVES AWAY. SCT -SHSN EXPECTED IN THE SNOWBELT REGION THROUGH SAT
AFTN BEFORE DISSIPATING LATE IN THE DAY.

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...GRUMM/FITZGERALD
AVIATION...DEVOIR

AREA FORECAST DISCUSSION

NWS SIOUX FALLS SD

900 PM CST FRI FEB 8 2013

.DISCUSSION.../ISSUED AT 900 PM CST/
STRATUS IS SPREADING BACK INTO THE FORECAST AREA FROM THE SOUTHEAST
AND SHOULD BE COVERING THE NORTHEAST 60-70 PERCENT OF OUR AREA AFTER
MIDNIGHT. THE SOUTHWEST CORNER WILL STAY MOSTLY CLEAR FOR A WHILE
THEN SHOULD GET SOME INCREASE IN HIGHER CLOUDS. WILL KEEP SOME AREAS
OF FOG AS WE HAVE FOR AFTER MIDNIGHT. AT THIS POINT DOES NOT LOOK
LIKE IT WILL GET VERY DENSE ANYWHERE IN THE STIFF FLOW...STRATUS
WOULD HAVE TO LOWER MORE THAN CURRENTLY EXPECTED TO GET ANYTHING
HALFWAY DENSE. MEANWHILE...WINDS ARE BEHAVING AS EXPECTED AND
SHOULD BEGIN TO SLOWLY DROP OFF LATER OUT WEST. TEMPERATURES WILL
NOT DO MUCH DROPPING SO SHOULD NOT BE MUCH OF A PROBLEM...THOUGH IT
IS POSSIBLE THAT THE FAR WEST COULD DROP A LITTLE MORE THAN WE HAVE
LATE IF THERE IS NOT MUCH INCREASE IN CLOUDS.

.AVIATION.../FOR THE 00Z TAF ISSUANCE/
MAIN FORECAST CHALLENGE THROUGH THIS TAF PERIOD WILL BE POTENTIAL
REDEVELOPMENT OF IFR-LIFR STRATUS LATER TONIGHT...WITH PRECIPITATION
ISSUES LOOKING TO HOLD OFF UNTIL AFTER THIS FORECAST PERIOD. WILL
CONTINUE TO SIDE WITH RAP SOUNDINGS REGARDING STRATUS POTENTIAL AS
THIS MODEL HAS HAD BEST GRASP OF THE PERSISTENT LOW LEVEL MOISTURE
ACROSS THE AREA. MOST AREAS HAVE SEEN STRATUS CLEAR AS OF THE START
OF THIS PERIOD...BUT RAP SHOWS REDEVELOPMENT DURING THE LATTER PART
OF THE EVENING AND OVERNIGHT...SO HAVE ADDED IFR-LIFR CEILINGS BACK
INTO THE TAFS GENERALLY AFTER 04Z-05Z...THOUGH CONFIDENCE IS RATHER
LOW THAT THIS REDEVELOPMENT WILL OCCUR. THINK WINDS WILL STAY UP
ENOUGH THAT VISIBILITY RESTRICTIONS WILL BE LIMITED...THOUGH PATCHY
MVFR VISIBILITY IS POSSIBLE. ANY STRATUS/FOG WILL LINGER THROUGH THE
MID-LATE MORNING HOURS SATURDAY...BEFORE STRONGER MIXING AHEAD OF
SIGNIFICANT WINTER SYSTEM AIDS IN CLEARING TO VFR CONDITIONS FOR
SATURDAY AFTERNOON.

.PREV DISCUSSION.../ISSUED AT 350 PM CST/
STRATUS FIELD MELTING AWAY ACROSS PORTIONS OF THE FORECAST AREA
WHILE IN OTHER AREAS IT IS HOLDING STEADFAST. RAP SUGGESTS THAT
STRATUS WILL BECOME MORE WIDESPREAD ACROSS THE AREA THROUGH THE
EVENING HOURS...AND EVEN SUGGESTS THE POTENTIAL FOR FOG DEVELOPING
ALONG AND EAST OF THE JAMES RIVER VALLEY. HAVE ADDED MENTION OF FOG
ALONG AND EAST OF THE JAMES RIVER VALLEY...BUT HAVE NOT GONE AS
BULLISH AS HE RAP WHICH WOULD SUGGEST THE POTENTIAL FOR A DENSE FOG
ADVISORY.

QUESTIONS STILL REMAIN AS TO HOW LONG THE STRATUS WILL LINGER DURING
THE DAYLIGHT HOURS ON SATURDAY. OVERALL...SYNOPTIC PATTERN SUGGESTS
WARM FRONT APPROACHING FROM THE SOUTH WITH 925 HPA TEMPERATURE
WARMING 2-3 DEGREES C IN THE 18 TO 00Z TIME FRAME. THIS SHOULD LEAD
TO A FAIR AMOUNT OF LATE DAY HEATING...WITH LATE AFTERNOON/EARLY
EVENING HIGHS. HAVE OUTSIDE CHANCE OF A SHOWER DEVELOPING IN THE
LATE AFTERNOON HOURS ACROSS CENTRAL SOUTH DAKOTA...BUT MAIN
PRECIPITATION SHOULD HOLD OFF THROUGH 00Z SUNDAY.

SATURDAY NIGHT WILL START TO BE A TRANSITION PERIOD TO WEATHER
ACROSS THE AREA AS STRONG JET STARTS TO LIFT OUT OF THE SOUTHERN
ROCKIES AND TOWARD THE CENTRAL PLAINS. LOW LEVEL THERMAL BOUNDARY
SHOULD SHARPEN ALONG DEVELOPING INVERTED TROUGH. SURGE OF MOISTURE
WILL PUSH INTO THE SYSTEM AS LOW LEVEL JET INCREASES...AND GOOD
DYNAMIC NUDGE WILL DEVELOP AS DRY SLOT PUSHES NORTH THROUGH
NEBRASKA. AS THIS FIRST LOBE LIFTS NORTHEASTWARD THROUGH THE PLAINS
DURING THE EVENING...SOME ELEVATED INSTABILITY INDICATED...AND WHILE
SURFACE TEMPS SHOULD BE SAFELY ABOVE FREEZING...MAY END UP WITH SOME
ICE PELLETS WITH SHOWERY PRECIPITATION. WILL GET SECONDARY AREA WITH
MAIN DIV Q/PV ADVECTION LATER IN NIGHT FROM SOUTHWEST...WHICH SHOULD
MAKE FOR MORE WIDESPREAD SHOWERS...BECOMING MORE STRATIFORM BACK IN
DEFORMATION THROUGH WESTERN CWA. WOULD NOT BE SURPRISED TO FIND A
FEW RUMBLES OF THUNDER BY LATE NIGHT GIVEN THE 800 HPA LI NEAR
ZERO. THIS COULD PRESENT A SMALL WILD CARD TOWARD TYPE IF DEEPER
CONVECTION BECOMES ESTABLISHED. HOWEVER...FOR THE MOST PART...HARD
TO PICTURE A GREAT DEAL OF SNOW WITH MOST OF THE PRECIPITATION ON
SATURDAY NIGHT...WITH MORE INTENSITY IN THE FAR WEST AND SOME
SLIGHTLY COOLER/DRIER AIR TO THE NORTH AIDING IN MIX/CHANGE
POTENTIAL. INVERTED TROUGH SHOULD BE FAIRLY CLOSE TO THE JAMES
VALLEY BY DAYBREAK SUNDAY...PERHAPS A BIT WESTWARD...WITH BULK OF
ANY FROZEN PRECIPITATION FORCED ALONG AND BEHIND FEATURE.

MODEL TRENDS ARE STARTING TO GRAVITATE TOWARD A SOLUTION CENTERED
AROUND AN ECMWF/GFS TRACK TO WAVE AS IT PUSHES OUT INTO THE PLAINS
AND ACROSS THE AREA ON SUNDAY. NAM CONTINUES TO BE THE NORTHERN AND
CANADIAN GLOBAL THE SOUTHERN OUTLIERS. FOLLOWING ALONG THE GENERAL
GUIDANCE...WAVE WILL PUSH VERY CLOSE TO THE MIDDLE OF THE CWA...
PERHAPS A BIT TO THE EAST...COLLAPSING THE INVERTED TROUGH CLOSER TO
I29 BY MIDDAY. FAIRLY SOLID LOOK TO DRY SLOT PUSHING NORTHWARD
THROUGH EASTERN CWA AHEAD OF THIS FEATURE...AND TRENDED BACK POPS
TOWARD SCATTERED FOR A TIME DURING THE MORNING...WITH PERHAPS A
LITTLE THUNDER AS WELL. WIDESPREAD PRECIPITATION BACK TO THE WEST
AS TROWAL BECOMES FAIRLY WELL ESTABLISHED BY EARLY SUNDAY...
WITH LIFT INITIALLY INDICATED ON THE NORTHWEST FLANK. HOWEVER...
FRONTOGENETIC FORCING GRADUALLY INCREASES ON THE SOUTHEAST FLANK OF
THE TROWAL AS SUNDAY GOES ON...WITH LOW EPV SUPPORTING AN ENHANCING
FRONTAL CIRCULATION...THE FOCUS FOR THE SOUTHEASTWARD COLLAPSING
SNOW BAND ON LATER SUNDAY AFTERNOON AND EVENING. FAIRLY STRONG LIFT
IN THE DENDRITIC GROWTH ZONE INDICATED...BUT NOT TOO DEEP A LAYER...
AND EFFICIENCY MAY SUFFER A BIT FOR THAT. SNOW RATIO IN MAX BAND
FROM 12-16 TO 1. RESULTING 8-12 INCHES OF SNOWFALL EXPECTED OVER THE
NORTHWEST THIRD OR SO OF THE AREA WILL INTERACT WITH STRONG NORTH
TO NORTHWEST WINDS BEHIND THE INVERTED TROUGH AS SYSTEM WRAPS UP
LATER SUNDAY AND SUNDAY NIGHT. WITH 30-40 KNOTS OF 925 HPA
WIND...SHOULD EASILY SUPPORT THREAT OF BLIZZARD CONDITIONS.
SHARPENED UP WITH OVERALL SNOWFALL TOTALS ON THE SOUTHEAST SIDE OF
THE BAND...AND WILL LIKELY NEED FURTHER SHARPENING ONCE DETERMINATION
OF THE LONGER LINGERING TROWAL SNOWFALL CAN BE DETERMINED.

IN TERMS OF HEADLINE DECISIONS...FAIRLY OBVIOUS NEED TO DELAY THE
START TIME IN THE WESTERN GROUP BY AT LEAST 6H...WITH VERY LITTLE
SNOWFALL AND THE WIND LIKELY NOT MUCH OF AN ISSUE UNTIL WELL AFTER
06Z. CONSIDERED DELAYING START TO THE MORE EASTERN GROUP AS WELL FOR
SIMILAR REASONS...ESPECIALLY THE FAR EAST WHICH WILL NOT SEE
INVERTED TROUGH PASSAGE AND INCREASE IN WINDS UNTIL TOWARD EVENING
ON SUNDAY. DID SPLIT OFF THE FAR EASTERN AREAS AND DELAY START UNTIL
LATE AFTERNOON SUNDAY...AND ADDED IN A FEW COUNTIES BORDERING THE
EAST EDGE OF THE EXISTING WATCH...MAINLY WHERE SNOWFALL OF 3 TO 4
INCHES WOULD BE COMBINING WITH GUSTY NORTHWEST WINDS TO 25 TO
40 MPH. ALSO...GIVEN THE WINDS WHICH ARE LIKELY TO ONLY BE ON A SLOW
DOWNWARD TREND BY EARLY MONDAY...EXTENDED THE WATCH THROUGH MIDDAY
MONDAY...BUT WORST CONDITIONS ARE CERTAINLY TO BE EXPECTED FROM EAST
CENTRAL SD INTO NORTHERN PARTS OF SW MN BY MONDAY MORNING.

CHANGES TO THE TUE THROUGH FRIDAY TIME PERIOD LIMITED DUE TO
ATTENTION ON THE MUCH MORE SIGNIFICANT ISSUES OF THE SHORTER TERM.
CLIPPER SYSTEM WORKING SOUTHEAST WEDNESDAY NIGHT AND THURSDAY SHOULD
BE ACCOMPANIED BY A PERIOD OF SNOW SHOWERS...WITH AMPLIFICATION OF
SYSTEM DRAWING DOWN SOME MUCH COLDER AIR. MAY BE A LITTLE MORE MESSY
THAN CURRENTLY GIVING CREDIT FOR...WITH AMPLIFICATION STRENGTHENING
GRADIENT TO 35 TO 45 KNOTS AT 925 HPA BEHIND SYSTEM ON THURSDAY AND
THURSDAY EVENING. FOR THE TIME...INCREASED POPS A TOUCH OVER THE
INITIALIZATION SLIGHTS/LOW CHANCE. /CHAPMAN

.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING FOR
MNZ071-072-097.

BLIZZARD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING FOR
MNZ080-081-098.

NE...NONE.
SD...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING FOR
SDZ040-054>056-059>062-064-065-068.

BLIZZARD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING FOR
SDZ066-067-069.

BLIZZARD WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY MORNING
FOR SDZ038-039-050-052-053-057-058-063.

AREA FORECAST DISCUSSION

NWS SIOUX FALLS SD

555 PM CST FRI FEB 8 2013

.DISCUSSION.../ISSUED AT 350 PM CST/
STRATUS FIELD MELTING AWAY ACROSS PORTIONS OF THE FORECAST AREA
WHILE IN OTHER AREAS IT IS HOLDING STEADFAST. RAP SUGGESTS THAT
STRATUS WILL BECOME MORE WIDESPREAD ACROSS THE AREA THROUGH THE
EVENING HOURS...AND EVEN SUGGESTS THE POTENTIAL FOR FOG DEVELOPING
ALONG AND EAST OF THE JAMES RIVER VALLEY. HAVE ADDED MENTION OF FOG
ALONG AND EAST OF THE JAMES RIVER VALLEY...BUT HAVE NOT GONE AS
BULLISH AS HE RAP WHICH WOULD SUGGEST THE POTENTIAL FOR A DENSE FOG
ADVISORY.

.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING FOR
MNZ071-072-097.

BLIZZARD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING FOR
MNZ080-081-098.

NE...NONE.
SD...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING FOR
SDZ040-054>056-059>062-064-065-068.

BLIZZARD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING FOR
SDZ066-067-069.

BLIZZARD WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY MORNING
FOR SDZ038-039-050-052-053-057-058-063.

AREA FORECAST DISCUSSION

NWS SIOUX FALLS SD

1054 AM CST THU FEB 7 2013

.DISCUSSION.../ISSUED AT 1054 AM CST/
A LARGE SWATH OF LOW LEVEL STRATUS CURRENTLY LOCKED IN ACROSS THE
NORTHERN PLAINS AND UPPER MIDWEST THIS MORNING. WITH LOW LEVEL
NORTHERLY WINDS EXPECTED TO PERSIST THROUGH AT LEAST MIDNIGHT
TONIGHT...DO NOT EXPECT MUCH IF ANY IMPROVEMENT IN CLOUD COVER
ACROSS THE ENTIRE TODAY...WHICH IS SUPPORTED BY THE RAP AND SREF.
COULD SEE SOME LIFTING NEAR THE MISSOURI VALLEY...BUT WITH SATELLITE
LOOPS DEPICTING THE STRATUS EXTENDING WELL SOUTH OF THE CWA...WILL
LEAVE CLOUDS IN PLACE EVERYWHERE. WITH THE STRATUS IN AND NORTHERLY
WINDS IN PLACE...TEMPERATURES WILL NOT BUDGE MUCH FROM CURRENT
READINGS IN THE 20S. DID LOWER HIGHS A FEW DEGREES IN THE SOUTH WITH
THE EXPECTATION THAT THE STRATUS WILL PERSIST BUT MAY HAVE TO LOWER
FURTHER IF TEMPERATURE TRENDS CONTINUE...ESPECIALLY IN SOUTH CENTRAL
SOUTH DAKOTA.

.AVIATION.../FOR THE 18Z TAF ISSUANCE/
LOW STRATUS LAYER IS EXPECTED TO PERSIST ACROSS THE ENTIRE FORECAST
AREA THROUGH TODAY AND TONIGHT WITH NORTHERLY WINDS IN PLACE.
CEILINGS WILL GENERALLY BE AROUND 600 TO 1000 FEET THROUGH THE TAF
BUT COULD BRIEFLY RISE TO THE 1500 FOOT RANGE THIS AFTERNOON.
VISIBILITY WILL BE AS LOW AS 3SM THROUGH AROUND 08/03Z WITH LOWER
CONDITIONS TO AROUND 2 TO 5 SM POSSIBLE OVERNIGHT. GRADUAL CEILING
AND VISIBILITY IMPROVEMENT WILL BEGIN AFTER 08/09Z WITH WINDS
TURNING SOUTHERLY...LIKELY BEGINNING FROM THE SOUTHWESTERN CWA AND
EXPANDING NORTHEAST THROUGH 18Z.

.PREV DISCUSSION.../ISSUED AT 438 AM CST/
STRATUS CONTINUES TO MOVE IN FROM THE NORTH AND EXTENDS WELL INTO
NORTH DAKOTA. WITH WEAK NORTHERLY BOUNDARY LAYER FLOW CONTINUING
THOUGH THE DAY...FEELING IS THIS STRATUS WILL LINGER FOR MOST OF THE
DAY ACROSS THE ENTIRE CWA. THIS IS SHOWN WELL BY THE RAP AND HRRR.
THINKING IS THE STRATUS BEGINS TO ERODE ON THE SOUTHERN EDGE A BIT
BY LATE IN THE DAY...WITH THE BEST CHANCE OF CLEARING TOWARDS THE
MISSOURI RIVER. WITH THE CLOUD COVER...WENT AHEAD AND CONTINUED THE
DOWNWARD TREND WITH HIGHS. HOWEVER WOULD NOT BE SURPRISED IF
SOUTHERN AREAS ARE STILL FORECAST A BIT TOO WARM...BUT DID NOT WANT
TO GO TOO COOL IN CASE THE SUN DOES MANAGE TO COME OUT THIS
AFTERNOON. COULD SEE A BIT OF PATCHY FREEZING DRIZZLE ACROSS HIGHWAY
14 CORRIDOR THIS MORNING WHERE MOISTURE IS DEEPEST...BUT CURRENTLY
NOT EXPECTING ANYTHING WIDESPREAD. AS BOUNDARY LAYER FLOW TURNS MORE
EASTERLY TONIGHT...THINKING STRATUS AND AREAS OF FOG REMAIN OR
REFORM OVER MOST OF THE AREA...ESPECIALLY EAST OF THE JAMES RIVER.
WITH THE CLOUDS AND LIGHT BREEZE...STAYED ON THE WARMER SIDE OF
GUIDANCE FOR LOWS...MAINLY TEENS AND LOWER 20S. HIGHS A BIT TRICKY
ON FRIDAY...WITH STRATUS LIKELY SLOW TO EXIT ACROSS OUR EAST. NAM IS
A BIT OF AN OUTLIER WARMING THE LOW LEVELS QUICKEST...THUS FOLLOWED
CLOSER TO THE ECMWF AND GFS SOLUTIONS...WITH HIGHS IN THE LOW 30S
SOUTHWEST MINNESOTA TO THE LOW 50S NEAR GREGORY COUNTY. A 30 TO 40
KT JET AT 925MB WILL LIKELY PUSH SOUTHERLY WINDS TO NEAR ADVISORY
CRITERIA FRIDAY AFTERNOON WEST OF THE JAMES RIVER. SOUTHERLY WINDS
WILL STAY BLUSTERY ACROSS THE ENTIRE CWA FRIDAY NIGHT...KEEPING LOWS
MAINLY IN THE MID TO UPPER 20S.

ATTENTION THEN TURNS TO A WAVE EJECTING OUT OF THE COLORADO ROCKIES
AND INTO THE PLAINS. MODELS STILL IN FAIRLY GOOD AGREEMENT WITH THIS
SYSTEM...BUT JUST SLIGHT SHIFTS IN THE TRACK WILL HAVE SIGNIFICANT
IMPACTS ON WEATHER TYPE ACROSS OUR CWA. GFS AND ECMWF HAVE TRENDED
SLIGHTLY FURTHER NORTH WITH THE WAVE AND SURFACE LOW...AND THUS
WARMER WITH THEIR TEMPERATURE PROFILES. GFS ENSEMBLE MEAN IS VERY
CLOSE TO THE ECMWF...AND THUS WILL FOLLOW A SOLUTION CLOSEST TO THE
ECMWF FOR NOW. THIS RESULTS IN A SOUTH TO NORTH MOVING AREA OF
MODERATE TO AT TIMES HEAVY PRECIPITATION SATURDAY NIGHT INTO SUNDAY
MORNING...WITH THE DRY SLOT MOVING INTO NORTHWEST IOWA ON
SUNDAY...AND THE HEAVIER PRECIP BAND ACROSS OUR NORTHWEST.

TEMPERATURE PROFILES CONTINUE TO SUPPORT A MAINLY RAIN EVENT ACROSS
NORTHWEST IOWA...WITH EVEN AN ISOLATED THUNDERSTORM POSSIBLE. IN THE
SIOUX FALLS AREA AND VICINITY...IT LOOKS LIKE RAIN
INITIALLY...BEFORE POSSIBLY MIXING OR CHANGING TO SNOW AS
EVAPORATIVE AND DYNAMIC COOLING TAKE PLACE LATE SATURDAY
NIGHT...THEN BACK TO ALL RAIN SUNDAY MORNING AS THE LOW APPROACHES
AND WARM LOW LEVEL TEMPERATURES MOVE IN...AND FINALLY BACK TO SOME
SNOW SUNDAY EVENING AS THE INVERTED TROUGH PUSHES EAST AND COLD AIR
RUSHES IN ON THE BACKSIDE OF THE STORM. THE FURTHER NORTH TRACK ALSO
SUGGESTS THAT SOME RAIN MAY OCCUR AS FAR NORTHWEST AS HURON SATURDAY
EVENING BEFORE COLD AIR MOVES IN OVERNIGHT. OVERALL...THE AREA OF
GREATEST SNOWFALL POTENTIAL REMAINS FROM CHAMBERLAIN TO HURON TO
JUST NORTH OF BROOKINGS AND MARSHALL...WHERE 6 OR MORE INCHES SEEM
POSSIBLE. OTHER ISSUE WILL BE STRONG NORTHWEST WINDS LATER SUNDAY
AFTERNOON INTO SUNDAY NIGHT ON THE COLD SIDE OF THE INVERTED TROUGH.
ADVISORY LEVEL WINDS SEEM PROBABLE...AND THIS COMBINED WITH THE SNOW
MAY CAUSE BLIZZARD OR NEAR BLIZZARD CONDITIONS IN THE ABOVE AREA
WHERE SNOW AMOUNTS WILL BE HIGHEST. ACCUMULATIONS SHOULD DROP OFF AS
YOU HEAD SOUTHEAST OF THIS REGION...WHERE RAIN SHOULD HOLD AMOUNTS
DOWN. AGAIN...ANY SHIFT IN STORM TRACK WILL SHIFT THE ABOVE
DESCRIPTION. FOR EXAMPLE...THE GEM IS BY FAR THE FURTHEST SOUTH
SOLUTION SHOWING THE HEAVIEST SNOW ALONG THE INTERSTATE 90 CORRIDOR.
THIS OUTLIER SOLUTION IS BEING DISCARDED AT THIS TIME...BUT FUTURE
TRENDS IN MODELS SOLUTIONS WILL HAVE TO BE MONITORED. /CHENARD

WITH CYCLONIC FLOW THROUGHOUT THE ATMOSPHERE AND A SECOND WEAK WAVE
MOVING ACROSS WESTERN MINNESOTA...LIKELY TO BE A LOT OF CLOUDS EAST
OF I29 MONDAY...ESPECIALLY EARLY IN THE DAY. THERE ALSO BE ENOUGH
LIFT TO PRODUCE SOME FLURRIES OR LIGHT SNOW...PRIMARILY IN SOUTHWEST
MINNESOTA. ANY ACCUMULATIONS WOULD BE LESS THAN AN INCH IF THERE IS
ANY. HOWEVER...925 MB WINDS IN ALL MODELS ARE STILL FROM 30 TO 40
KTS THROUGH MIDDAY BEFORE WEAKENING AS A RIDGE MOVES IN FROM THE
WEST AND WINDS DECREASE. WITH A FAIRLY WELL MIXED BOUNDARY
LAYER...WOULD EXPECT SUSTAINED WINDS OVER 20 MPH WITH GUSTS AGAIN
OVER 30 MPH FOR MUCH OF THE DAY EAST OF I29.

AFTER MONDAY THERE ARE DIFFERENCES BETWEEN THE ECMWF AND GFS IN HOW
FAST THE SURFACE RIDGE MOVES EAST AND THEN THE DEGREE OF WARMING
TOWARD THE MIDDLE OF NEXT WEEK. THE ECMWF IS SLOWER WITH THIS RIDGE
AND ALSO WARMER BY NEXT WEDNESDAY WITH THE POSSIBILITY OF
APPROACHING OR EVEN RISING ABOVE FREEZING WEDNESDAY AFTERNOON IN
MOST OF THE AREA. THE GFS WOULD KEEP TEMPERATURE WITHIN A COUPLE OF
DEGREES OF NORMAL. WITH UNCERTAINTY IN BOTH THE DEGREE OF WARMING
AND THE AMOUNT OF SNOWCOVER THAT WILL EXIST...STAYED WITH A COOLER
CONSENSUS FORECAST WITH HIGHS IN THE 20S TO LOWER 30S ON
TUESDAY...AND ABOUT 3 TO 5 DEGREES WARMER ON WEDNESDAY. TUESDAY AND
WEDNESDAY ARE EXPECTED TO BE DRY./SCHUMACHER

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.

AREA FORECAST DISCUSSION

NWS SIOUX FALLS SD

553 AM CST THU FEB 7 2013

.DISCUSSION.../ISSUED AT 438 AM CST/
STRATUS CONTINUES TO MOVE IN FROM THE NORTH AND EXTENDS WELL INTO
NORTH DAKOTA. WITH WEAK NORTHERLY BOUNDARY LAYER FLOW CONTINUING
THOUGH THE DAY...FEELING IS THIS STRATUS WILL LINGER FOR MOST OF THE
DAY ACROSS THE ENTIRE CWA. THIS IS SHOWN WELL BY THE RAP AND HRRR.
THINKING IS THE STRATUS BEGINS TO ERODE ON THE SOUTHERN EDGE A BIT
BY LATE IN THE DAY...WITH THE BEST CHANCE OF CLEARING TOWARDS THE
MISSOURI RIVER. WITH THE CLOUD COVER...WENT AHEAD AND CONTINUED THE
DOWNWARD TREND WITH HIGHS. HOWEVER WOULD NOT BE SURPRISED IF
SOUTHERN AREAS ARE STILL FORECAST A BIT TOO WARM...BUT DID NOT WANT
TO GO TOO COOL IN CASE THE SUN DOES MANAGE TO COME OUT THIS
AFTERNOON. COULD SEE A BIT OF PATCHY FREEZING DRIZZLE ACROSS HIGHWAY
14 CORRIDOR THIS MORNING WHERE MOISTURE IS DEEPEST...BUT CURRENTLY
NOT EXPECTING ANYTHING WIDESPREAD. AS BOUNDARY LAYER FLOW TURNS MORE
EASTERLY TONIGHT...THINKING STRATUS AND AREAS OF FOG REMAIN OR
REFORM OVER MOST OF THE AREA...ESPECIALLY EAST OF THE JAMES RIVER.
WITH THE CLOUDS AND LIGHT BREEZE...STAYED ON THE WARMER SIDE OF
GUIDANCE FOR LOWS...MAINLY TEENS AND LOWER 20S. HIGHS A BIT TRICKY
ON FRIDAY...WITH STRATUS LIKELY SLOW TO EXIT ACROSS OUR EAST. NAM IS
A BIT OF AN OUTLIER WARMING THE LOW LEVELS QUICKEST...THUS FOLLOWED
CLOSER TO THE ECMWF AND GFS SOLUTIONS...WITH HIGHS IN THE LOW 30S
SOUTHWEST MINNESOTA TO THE LOW 50S NEAR GREGORY COUNTY. A 30 TO 40
KT JET AT 925MB WILL LIKELY PUSH SOUTHERLY WINDS TO NEAR ADVISORY
CRITERIA FRIDAY AFTERNOON WEST OF THE JAMES RIVER. SOUTHERLY WINDS
WILL STAY BLUSTERY ACROSS THE ENTIRE CWA FRIDAY NIGHT...KEEPING LOWS
MAINLY IN THE MID TO UPPER 20S.

.AVIATION.../FOR THE 12Z TAF ISSUANCE/
STRATUS HAS SPREAD ACROSS MOST OF THE AREA THIS MORNING. WITH
PERSISTENT NORTHERLY FLOW THROUGH THE DAY EXPECT STRATUS TO CONTINUE
ADVECTING SOUTH WELL INTO NEBRASKA AND THIS WILL KEEP IFR CIGS OVER
THE AREA THROUGH 00Z FRIDAY. THERE IS A SMALL CHANCE THAT WARMING
THIS AFTERNOON COULD TEMPORARILY RAISE CIGS ABOVE 1000 FT BUT THE
FEBRUARY SUN IS STILL PRETTY WEAK AND THE STRATUS IS A FEW THOUSAND
FEET THICK SO DO NOT BELIEVE SURFACE WARMING WILL BE ENOUGH TO LIFT
CEILINGS MORE THAN A COUPLE HUNDRED FEET. WITH THE RIDGE AXIS MOVING
OVER TONIGHT...THERE WILL BE NO ADVECTION OF DRYER AIR TO ERODE
CLOUDS. INSTEAD CLOUDS WILL LIKELY PERSIST UNTIL SOUTHERLY FLOW
INCREASES LATE TONIGHT AND FRIDAY MORNING. SO KEPT IFR CONDITIONS IN
KFSD AND KSUX THROUGH 12Z AND DID NOT CLEAR OUT KHON UNTIL LATE
TONIGHT. IN ADDITION...LIGHT FOG WILL LIKELY LIMIT VSBYS BOTH THIS
MORNING AND AGAIN OVERNIGHT TO 3 TO 5 SM. /SCHUMACHER
&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.

AREA FORECAST DISCUSSION

NWS SIOUX FALLS SD

438 AM CST THU FEB 7 2013

.AVIATION.../FOR THE 06Z TAF ISSUANCE/
IFR TO MVFR CEILINGS NORTH OF A HON-MML LIKE AT 06Z WILL SAG SOUTH
ACROSS THE CWA THROUGH THE NIGHT AND INTO THURSDAY MORNING.
CONDITIONS MAY BECOME VFR SOUTH OF I90 AFTER 18Z BUT LIKELY TO
REMAIN MVFR TO THE NORTH THROUGH 06Z FRIDAY.

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY

NWS RAPID CITY SD

936 PM MST WED FEB 6 2013

.AVIATION...06Z TAFS
VFR CONDITIONS EXPECTED THROUGH THURSDAY. LEFTOVER -SHRASN FROM
KIEN TO KICR WILL CONTINUE TO DISSIPATE THIS EVENING.

.PREV DISCUSSION... /ISSUED 435 PM MST WED FEB 6 2013/

UPDATE...12Z UNR WRF/LATEST RAP SHOWED A SMALL AREA OF CONVECTIVE
-SHRASN OVER FAR SOUTHWEST SD INTO A SMALL PORTION OF SOUTH
CENTRAL SD. THIS MATCHES LATEST KUDX RADAR TRENDS...SO WILL ADD
SOME ISOLATED -SHRASN TO THE FORECAST FOR EARLY THIS EVENING.

PREV DISCUSSION... /ISSUED 302 PM MST WED FEB 6 2013/

DISCUSSION...CURRENT SURFACE ANALYSIS SHOWS WEAK LOW PRESSURE OVER
CENTRAL ND...WITH A SURFACE TROF STRETCHING SOUTHWARD ACROSS
CENTRAL SD. UPPER LEVEL ANALYSIS SHOWS WEAK SHORTWAVE MOVING
ACROSS THE NORTHERN HIGH PLAINS...WITH A RIDGE BUILDING OVER THE
PACIFIC NW...AND A LOW OFF THE PACIFIC COAST. SKIES ARE PARTLY
SUNNY ACROSS MUCH OF THE AREA. REGIONAL RADARS NOT SHOWING MUCH IN
THE WAY OF ECHO RETURNS...EXCEPT FOR SOME WEAK RETURNS OVER THE
HIGHER TERRAIN OF WY AND THE BLACK HILLS. WITH ONLY WEAK LIFT AND
LIMITED LOW LEVEL MOISTURE IN PLACE...NOT EXPECTING MUCH MORE
THAN A FEW SPRINKLES/FLURRIES ACROSS THE BLACK HILLS THROUGH THE
AFTERNOON. TEMPS ARE CURRENTLY IN THE 40S AND LOWER 50S AT MOST
LOCATIONS. NORTHWESTERLY WINDS REMAIN BREEZY TO WINDY ACROSS
PORTIONS OF WESTERN SD...MAINLY FROM THE 2WX TO RAP CORRIDOR.

MILD WEATHER WILL CONTINUE THROUGH FRIDAY AS AN UPPER LEVEL RIDGE
SLIDES EAST ACROSS THE ROCKIES AND NORTHERN PLAINS. UPPER LOW OFF
THE PACIFIC NW COAST WILL MOVE SOUTHEAST INTO THE SOUTHWESTERN
CONUS LATE THIS WEEK...AND THEN TRACK ACROSS THE CENTRAL ROCKIES
AND PLAINS OVER THE WEEKEND. THE TRACK OF THE SYSTEM IS STILL
UNCERTAIN AT THIS POINT...BUT SOUTHERN PORTIONS OF THE CWA WILL
SEE THE BEST CHANCES FOR SNOW AND SOME ACCUMULATION...ESPECIALLY
ACROSS FAR SOUTHWESTERN INTO SOUTH CENTRAL SD.

FOR TONIGHT...SKIES WILL CLEAR OUT IN THE EVENING AS SHORTWAVE
MOVES EAST OF THE AREA. WINDS WILL ALSO DIMINISH AFTER SUNSET.
LOWS WILL MOSTLY BE IN THE 20S...WITH SOME TEENS IN THE USUAL
COLDER SPOTS. THE RIDGE WILL BUILD ACROSS THE AREA THURSDAY INTO
FRIDAY...WITH MOSTLY CLEAR SKIES AND MILD CONDITIONS PERSISTING.
THE WARMEST CONDITIONS WILL GENERALLY BE ACROSS WESTERN AND
CENTRAL AREAS ON THURSDAY AND ACROSS EASTERN AREAS ON FRIDAY.
BRISK SOUTHWESTERLY WINDS WILL DEVELOP LATE ON THURSDAY ACROSS
NORTHEASTERN WY AND THE NORTHERN BLACK HILLS AREA...PERSISTING
THROUGH THURSDAY NIGHT. SOME WIND GUSTS TO 40 MPH LOOK LIKELY
ACROSS FAVORED AREAS OF THE NORTHERN BLACK HILLS AND NORTHERN
FOOTHILLS.

AS THE RIDGE MOVES EAST BY FRIDAY NIGHT AND UPPER LOW MOVES INTO
THE CENTRAL ROCKIES...SOUTHWEST FLOW ALOFT WILL DEVELOP OVER THE
HIGH PLAINS. SHORTWAVE ENERGY IN THE FLOW AHEAD OF THE LOW WILL
TRACK ACROSS EASTERN WY OVERNIGHT. CLOUDS WILL INCREASE ACROSS THE
AREA...BUT LOW LEVEL MOISTURE WILL BE SLOW TO RETURN. THE SYSTEM
ALSO LOOKS TO BE A BIT SLOWER AS IT MOVES ACROSS THE ROCKIES. WILL
KEEP SOME LOW POPS FOR SNOW ACROSS SOUTHWESTERN PORTIONS OF
NORTHEASTERN WY AND DRY ELSEWHERE.

EXTENDED...POTENT EJECTING SW CONUS DISTURBANCE WILL SUPPORT A
STRONG WINTER STORM SYSTEM ACROSS THE CENTRAL AND NORTHERN PLAINS AT
THE START OF THE PERIOD...BRINGING WIND AND SNOW TO PORTIONS OF THE
FA. FORECAST MODELS HAVE COME TO CLOSE CONSENSUS PER THE
TRACK/STRENGTH/AND TIMING OF THIS SYSTEM...WITH AT LEAST
SEMI-NORTHERN STREAM FLOW PHASING STILL SUGGESTED IN ALL
DETERMINISTIC GUIDANCE. BRIEF BLOCKING PER THE EXPECTED WOUND UP SFC
CYCLONE AND ASSOCIATED UPPER LEVEL CLOSED LOW WILL LEAD TO A BRIEF
COOL DOWN THE EARLY PART OF NEXT WEEK AS LONG TRAJECTORY NORTHERLY
FLOW RESULTS OVER THE REGION. HOWEVER...SPLIT FLOW WILL QUICKLY
RETURN WITH WESTERN NOAM RIDGING SPILLING OVER INTO THE WESTERN
NORTHERN PLAINS BY EARLY NEXT WEEK...SLIGHTLY SLOWER THAN WHAT
PREVIOUS MODEL SOLUTIONS WHERE INDICATING. NO MAJOR CHANGES MADE TO
THE PREVIOUS FORECAST OTHER THAN CONTINUED THE TREND OF RAISING POPS
OVER SCENTRAL SD PER THIS WEEKEND/S STORM SYSTEM...DUE TO INCREASED
CONFIDENCE PER THIS SYSTEM/S TRACK GIVEN GROWING AGREEMENT PER
DETERMINISTIC MODELS. ANALYSIS OF FGEN/WAA/MID LAPSE RATES SUGGEST A
RATHER STRONG DEFORMATION ZONE WILL FORM OVER NORTHERN NE INTO
SD...WITH A PERIOD OF HEAVY SNOW LIKELY ESP GIVEN THE DEVELOPING
GOMEX CONNECTION INDICATED IN H85 THETA-E PROGS. THE EXACT TRACK OF
THE HEAVIEST SNOW IS STILL IN QUESTION...BUT CURRENT CONSENSUS
INDICATIONS SUGGEST INVOF TODD/MELLETTE/AND TRIPP COUNTIES AND
EAST...WHERE THE POTENTIAL FOR 4 TO 6 INCHES EXISTS. IN
ADDITION...VERY STRONG N/NW WINDS WOULD LIKELY CREATE AREAS OF
BLOWING AND DRIFTING SNOW...WITH SIG VIS REDUCTION. WILL FRESHEN THE
HWO FOR THIS CONCERN. THE REMAINDER OF THE FA WILL SEE MUCH LOWER
CHANCES FOR PRECIP WITH ACCUMS GENERALLY 2 INCHES TO A
DUSTING...SAVE THE NORTHERN BH WHERE HIGHER AMOUNTS ARE QUITE
POSSIBLE GIVEN A PERIOD OF UPSLOPE SUN/SUN NIGHT. COLD AIR WILL
SETTLE OVER THE REGION ON THE BACKSIDE OF THIS SYSTEM WITH BELOW
NORMAL TEMPS FORECAST MON. UPPER LEVEL RIDGING WILL DEVELOP BY
TUE...SUPPORTING WARMING TEMPS THROUGH WED...WITH NORMAL TO ABOVE
NORMAL TEMPS BY THEN...ESP IN AREAS THAN DON/T SEE MUCH SNOW THIS
WEEKEND.

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

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

AREA FORECAST DISCUSSION

NWS MORRISTOWN TN

653 PM EST FRI FEB 8 2013

.AVIATION...LOOKS LIKE THE LOW DECK WILL BE AROUND FOR THE LONG
HAUL WITH SATELLITE REVEALING CLOUDS FORMING EVEN IN THE GREAT
VALLEY. MOISTURE MAY REMAIN TRAPPED UNDER INVERSION THROUGH MUCH OF
THE NIGHT. THEREFORE...APPLIED SOME BKN MVFR CEILINGS WITH
OCCASIONAL BREAKS ALLOWING BRIEF PERIODS OF VFR WEATHER. RUC HAS A
NICE DEPICTION OF THE NEXT SEVERAL HOURS KEEPING THE LOW OVERCAST
IN PLACE. BREAK OUT ALL THE TERMINALS BETWEEN 12-14Z ON SATURDAY
FOR A NICE VFR SECOND HALF OF THE FORECAST PERIOD.

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.

AREA FORECAST DISCUSSION...UPDATED

NWS MILWAUKEE/SULLIVAN WI

930 PM CST FRI FEB 8 2013

.UPDATE...

KEEPING LAKE CLOUDS IN THROUGH MIDNIGHT...WITH A SLOW EROSION
AFTERWARD...AND ADJUSTING TEMPERATURES IN EASTERN LOCATIONS AS
NERLY 925 MB WINDS PUSHING LAKE MOISTURE IN ACROSS THE SE CORNER
OF THE CWA...BACKING CLOUDS INTO SOUTHEAST WAUKESHA AND EASTERN
WALWORTH COUNTIES. RAP 925 RH FORECASTS HAVING A GOOD HANDLE ON
THESE CLOUDS...AS WELL AS THE STRATUS ALONG THE DEW POINT GRADIENT
NEAR THE MS RIVER WITH THE RETURN FLOW ON SERLY SURFACE WINDS
BEHIND AXIS OF SURFACE HIGH PRESSURE.

DOWNWARD TEMPERATURE TREND WITH GOOD RADIATIONAL CONDITIONS ACROSS
REST OF CWA ON TRACK.

.AVIATION/06Z TAFS/...

AS MENTIONED ABOVE...WILL TREND MVFR STRATUS LAKE-CLOUD DECK OUT
OF EASTERN TAF SITES WITH RAP 925 MB RH. MINIMAL TEMP/DEW POINT SPREAD
WILL BRING TRANSIENT MVFR FOG TO TAF SITES OVERNIGHT...THOUGH
COULD BE MORE PREVAILING IF CLOUDS CLEAR THE EAST EARLIER THAN
EXPECTED AND/OR CALM SURFACE WINDS DO NOT BEGIN TO INCREASE FROM
WEST TO EAST OVERNIGHT BEHIND DEPARTING SURFACE HIGH.

00Z NAM AND GFS BREAK DOWN TIGHT DEW POINT GRADIENT TO THE WEST
WITH INCREASING SURFACE WINDS WITH EARLY DAYTIME MIXING. NAM
GUIDANCE WANTS TO BRING AN MVFR DECK INTO KMSN MID MORNING WITH LEADING
EDGE OF WARM AIR ADVECTION. WILL AWAIT A FINAL DECISION WHEN ALL
OF 00Z GFS DATA IS IN...BUT INCLINATION IS TO LEAVE VFR CONDITIONS
AT ALL SITES FROM MID-MORNING SATURDAY THROUGH THE REMAINDER OF
THE FORECAST.

.PREV DISCUSSION... /ISSUED 305 PM CST FRI FEB 8 2013/

VERY SHORT TERM...TONIGHT AND SATURDAY.

DRY WEATHER EXPECTED TONIGHT AND SATURDAY AS HIGH PRESSURE OVERHEAD
THIS EVENING SLIDES SLOWLY EASTWARD THROUGH TOMORROW. BIGGEST
FORECAST ISSUE IS TONIGHT...WITH SOME UNCERTAINTY IN LOW
TEMPERATURES AND FOG POTENTIAL.

CLOUDS CONTINUE TO ERODE FROM NORTHWEST TO SOUTHEAST THIS
AFTERNOON...WITH MOSTLY CLEAR SKIES EXCEPT FOR NEAR THE LAKE
EXPECTED BY EARLY EVENING. SFC TO 850 MB TEMPERATURES AND WINDS
SUGGEST THAT CLOUDS MAY LINGER NEAR THE LAKE INTO EARLY SATURDAY
MORNING...PARTICULARLY FROM PORT WASHINGTON SOUTHWARD. FARTHER
WEST...LIGHT TO CALM WINDS AND MOSTLY CLEAR SKIES MAY ALLOW FOR SOME
FOG DEVELOPMENT LATER TONIGHT...THOUGH THE HIGH WILL BE SHIFTING
EAST...ALLOWING WINDS TO PICK UP A BIT IN THE LOW LEVELS. THREW SOME
PATCHY FOG IN THE FORECAST FOR NOW.

TEMPERATURES WILL LIKELY FALL FAST THIS EVENING...ESPECIALLY WHILE
THE HIGH IS OVERHEAD. SHOULD SEE LOWEST TEMPS BY AROUND
MIDNIGHT...LIKELY NOT CHANGING A TON AFTER THAT AS THE LOW LEVEL
WINDS COME UP A BIT. A FAIRLY DECENT SPREAD AMONG MODELS FOR LOW
TEMPS TONIGHT. SIDED WITH THE LOWER END OF SOLUTIONS GIVEN PRETTY
GOOD RADIATIONAL COOLING CONDITIONS FOR A WHILE.

SHOULD BE PARTLY CLOUDY TOMORROW WITH TEMPS RUNNING NEAR NORMAL FOR
THE FIRST HALF OF FEBRUARY.

SHORT TERM...SATURDAY NIGHT THROUGH MONDAY.

SHORT TERM GUIDANCE REMAINS IN GOOD AGREEMENT ON MOSTLY RAIN EVENT
AFFECTING SOUTHERN WI ON SUNDAY. UPSTREAM SHORT WAVE TROUGH OVER
SOUTHWEST CONUS IS EXPECTED TO DEEPEN AS IT TRACKS ACROSS THE
INTERMOUNTAIN REGION INTO THE HIGH PLAINS ON SATURDAY AND THEN TRACK
NORTHEAST INTO THE UPPER MIDWEST SUNDAY AND SUNDAY NIGHT. STRONG
LOW LEVEL WINDS OF 45 TO 55 KTS WILL PULL DEEP MOISTURE RAPIDLY
NORTHWARD SATURDAY NIGHT AND SUNDAY. SOUTHERN WI WILL REMAIN ON THE
NORTHERN EDGE OF THIS PUSH OF WARM...MOIST AIR ON SUNDAY.
PRECIPITABLE WATER VALUES INCREASE RAPIDLY TO OVER THREE QUARTERS
INCH. THIS LOW LEVEL FORCING CONTRIBUTES TO AN AXIS OF MODERATE
LAYER Q-VECTOR CONVERGENCE THAT SPEEDS THRU SOUTHERN WI. HENCE WL
CONTINUE HIGH POPS FOR PRECIPITATION.

THE LOW LEVEL JET BEGINS TO AFFECT SRN WI LATE SATURDAY NIGHT
THROUGH MID-AFTN SUNDAY. SFC TEMPS EARLY SUN ARE EXPECTED TO BE
BELOW FREEZING. LOW LEVEL CRITICAL THICKNESSES AND TOP-DOWN PRECIP
METHOD SHOW THE LIKLIHOOD OF A PERIOD OF SLEET AND FREEZING RAIN
OVER SRN WI IN THE AREA OF STRONGEST LOW LEVEL CONVERGENCE. HENCE
SOME AREAS MAY RECEIVE UP TO ONE TENTH OF AN INCH OF LIGHT FREEZING
RAIN...HOWEVER ANY SLEET WOULD CUT BACK ON THE GLAZING. A WINTER
WEATHER ADVISORY MAY BE NEEDED SUN MRNG IN PARTS OF THE AREA SUN
MRNG.

TEMPERATURES WILL THEN WARM ABOVE FREEZING DURING THE LATE MRNG SO
THAT A PERIOD OF RAIN CAN BE EXPECTED INTO THE AFTN. A DRY PUSH OF
MID-LEVEL AIR WILL LIKELY END THE RAIN FOR A TIME IN THE AFTERNOON
LEAVING BEHIND PERHAPS SOME DRIZZLE. A SHORT WAVE ROTATING AROUND
THE UPPER LOW IN THE NORTHERN PLAINS WILL LIKELY BRING SOME LIGHT
RAIN BACK TO SOUTHERN WI SUN EVENING. COLDER AIR IS THEN EXPECTED
TO BRING A CHANCE OF -SN TO MOST OF THE AREA LATER SUN NIGHT INTO
MONDAY AS A LINGERING LOW PRESSURE TROUGH REMAINS NEARBY. NORTHERN
PORTIONS OF THE CWA MAY RECEIVE SOME LIGHT ACCUMULATIONS...LESS THAN
AN INCH INTO MONDAY.

LONG TERM...MONDAY NIGHT THROUGH FRIDAY.

LINGERING TROUGH CONTINUES TO WEAKEN OVER THE WESTERN GTLAKES MONDAY
NIGHT AS STRONG SFC LOW PRESSURE MOVES FARTHER EAST ACROSS SOUTHEAST
CANADA. HENCE WL END THREAT FOR -SN EARLY IN THE PERIOD. SOUTHERN
STREAM OF SPLIT FLOW THEN REMAINS ACTIVE FOR MIDWEEK...WITH DRY
WEST-NORTHWEST STEERING FLOW RESULTING IN TEMPERATURES REMAINING
AROUND SEASONAL NORMAL.

MEDIUM RANGE GUIDANCE TRENDING TOWARD HIGHER AMPLITUDE CLIPPER
TAKING SOUTHEAST TRACK IN NORTHERN STREAM AND AFFECTING PORTIONS OF
THE UPPER MIDWEST ON THURSDAY. LAST SEVERAL RUNS OF THE ECMWF AND
THE GFS DIFFERING ON STRENGTH AND TRACK BUT BOTH SHOW CLIPPER-TYPE
SYSTEM AFFECTING PORTIONS OF THE UPPER MIDWEST. EVEN THE UKMT AND
GEM-NHEM VALID AT 00Z/14 SHOW STRONG UPSTREAM SHORT WAVE PUSHING
INTO THE PAC NORTHWEST. HENCE WL CARRY A CHANCE FOR -SN FOR NOW
AROUND THIS TIME PERIOD. GFS ENSEMBLES VALID NEXT THURSDAY ARE
SHOWING ALOT OF UNCERTAINTY AND CHAOS IN THE LOW TO MID LEVEL
ENSEMBLE MEMBERS.

AVIATION /00Z TAFS/...

DRY WEATHER EXPECTED THROUGH THE DAY SATURDAY. LOW CLOUDS CONTINUE
TO ERODE FROM NORTHWEST TO SOUTHEAST THIS AFTERNOON...WITH MOSTLY
CLEAR SKIES EXCEPT FOR NEAR THE LAKE EXPECTED BY EARLY EVENING. SFC
TO 850 MB TEMPERATURES AND WIND SUGGEST THAT CLOUDS MAY LINGER NEAR
THE LAKE INTO EARLY SATURDAY MORNING...PARTICULARLY FROM PORT
WASHINGTON SOUTHWARD. JUST WENT SCT IN TAFS FOR NOW...BUT WILL
MONITOR SATELLITE TRENDS AND CONSIDER BKN MVFR CIGS IF LAKE EFFECT
CLOUDS BECOME AN ISSUE. AWAY FROM THE LAKE...LIGHT TO CALM WINDS AND
MOSTLY CLEAR SKIES MAY ALLOW FOR SOME FOG DEVELOPMENT LATER
TONIGHT...THOUGH HIGH PRESSURE WILL BE SHIFTING EAST...ALLOWING
WINDS TO PICK UP A BIT IN THE LOW LEVELS. WILL PROBABLY MAINTAIN
TEMPO MVFR VSBYS FOR NOW.

EXPECTING VFR CONDITIONS UNDER PARTLY CLOUDY SKIES TOMORROW...THOUGH
SOME MODELS HINTING AT ENOUGH LOW LEVEL MOISTURE FOR SOME MVFR CIGS.
SOMETHING TO KEEP AN EYE ON.

MARINE...

DECIDED TO CANCEL THE SMALL CRAFT ADVISORY FROM NORTH POINT LIGHT TO
SHEBOYGAN...AS OFFSHORE WINDS AND CURRENT WEBCAMS SUGGEST WAVES ARE
GENERALLY BELOW 4 FEET. FARTHER SOUTH...SEEMS HIGHER WAVES MAY
LINGER UNTIL EVENING DUE TO A MORE FAVORABLE FETCH...SO DECIDED TO
KEEP THE ADVISORY THERE UNTIL THE 00Z EXPIRATION TIME.

SMALL CRAFT ADVISORY CONDITIONS WILL LIKELY RETURN FOR SUNDAY AND
MONDAY AS STRONG LOW PRESSURE MOVES THROUGH THE REGION.

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

UPDATE...REM
TONIGHT/SATURDAY AND AVIATION/MARINE...DDV
SATURDAY NIGHT THROUGH FRIDAY...MBK

AREA FORECAST DISCUSSION

NWS LA CROSSE WI

549 PM CST FRI FEB 8 2013

.SHORT TERM...TONIGHT THROUGH MONDAY
315 PM CST FRI FEB 8 2013

SURFACE MAP HAS A RIDGE OF HIGH PRESSURE EXTENDING FROM HUDSON BAY
INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION. DRY FEED OF
AIR/SUBSIDENCE UNDER THE RIDGE WAS ERODING STRATUS DECK TO THE
SOUTHWEST AND WAS NOW CONFINED ACROSS PORTIONS OF SOUTHEAST MN AND
NORTHEAST IA. MEANWHILE...TEMPERATURES THIS AFTERNOON WERE SITTING
RIGHT AROUND NORMAL IN THE MIDDLE AND UPPER 20S.

08.12Z MODELS IN PRETTY DECENT AGREEMENT WITH THE TRACK OF THE STORM
SYSTEM AFFECTING THE AREA THIS WEEKEND. NAM SEEMS TO BE A BIT
FARTHER NORTH WITH THE TRACK. GENERALLY TOOK A CONSENSUS OF THE
MODELS.

STRATUS WILL BE PROBLEMATIC OVERNIGHT INTO SATURDAY. WITH THE RIDGE
AXIS MOVING EAST OF THE AREA OVERNIGHT/SATURDAY MORNING...WINDS WILL
SWING BACK TO THE SOUTH WHICH WILL ADVECT STRATUS BACK INTO THE
AREA. NAM 0-5KM RH FIELD SHOWS THIS TREND. HAVE ADDED A MENTION OF
FOG ALONG AND EAST OF THE MISSISSIPPI RIVER FROM LATER THIS EVENING
THROUGH SATURDAY MORNING WHERE IT WILL BE CALMER CLOSER TO THE RIDGE
AXIS LEADING TO A RAPID TEMPERATURE DROP OFF. HRRR MODEL SUGGESTS
THAT THIS FOG COULD GET LOCALLY DENSE WITH VSBY UNDER A 1/4 MILE.
OTHER MODELS ARE NOT AS RAMBUNCTIOUS. WILL HAVE TO KEEP A CLOSE EYE
ON THIS. DURING THE DAY SATURDAY... EXPECTING INCREASING SOUTHERLY
FLOW TO ADVECT MORE LOW LEVEL MOISTURE INTO THE AREA LEADING TO
CONTINUED STRATUS DEVELOPMENT. AT THE SAME TIME...INCREASING FLOW
MAY ACTUALLY HELP TO MIX THIS MOISTURE FOR SOME PARTIAL SUNSHINE
FROM TIME TO TIME. OTHERWISE...LOOK FOR TEMPERATURES TO WARM INTO
THE 30 TO 35 DEGREE RANGE.

ATTENTION THEN TURNS TO A STRONG STORM SYSTEM HEADING OUT OF THE
COLORADO ROCKIES INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION
LATER SATURDAY NIGHT THROUGH SUNDAY. THIS SYSTEM PROMISES A WINTRY
MIX FOR THE AREA...STARTING OFF IN THE VERY EARLY MORNING HOURS OF
SUNDAY AND ALONG/WEST OF THE MISSISSIPPI RIVER AS A SLEET/FREEZING
RAIN MIX...SPREADING EAST OF THE RIVER BY DAY BREAK. WITH DECENT
SURGE OF PRECIPITABLE WATER...THERE IS THE POTENTIAL FOR 1/10 TO
2/10 INCH OF ICE ACCUMULATION BEFORE TRANSITIONING TO RAIN BY LATER
SUNDAY MORNING/SUNDAY AFTERNOON AS WARM/MOIST AIR CONVEYOR BELT
WRAPS INTO THE AREA. THE EXCEPTION FOR A TOTAL TRANSITION TO RAIN
MAY BE ACROSS NORTH CENTRAL WI/TAYLOR COUNTY WHERE A MIX MAY HANG
AROUND LATER. OTHERWISE...LOOKING FOR A FAIRLY HEFTY AMOUNT OF
RAINFALL THROUGH THE DAY SUNDAY EXPECTED TO BE IN THE WITH 1/4 TO
1/2 INCH RANGE. THIS MAY LEAD TO SOME HYDROLOGY ISSUES WHICH IS
TALKED ABOUT BELOW IN THE HYDROLOGY SECTION.

AS THE STORM SYSTEM SWINGS NORTHEAST INTO EAST-CENTRAL MN/NORTHWEST
WI SUNDAY EVENING...LOOKING FOR A DRY SLOT TO WORK INTO THE
AREA...LEADING TO A DIMINISHING RAIN AND INTO A MORE DRIZZLE
SCENARIO EARLY IN THE EVENING...THEN A SWITCHING TO A LIGHT
SNOW/CHANCE OF DRIZZLE/FREEZING DRIZZLE SCENARIO IN THE LATE EVENING
AND OVERNIGHT AS COLDER AIR FILTERS IN UNDER THE LOW.

PLAN ON LINGERING DEFORMATION BAND LIGHT SNOW ON MONDAY AS THE LOW
PULLS OFF INTO ONTARIO. AT THIS POINT...LOOKS LIKE PERHAPS AN INCH
OF ACCUMULATION CAN BE EXPECTED MAINLY ALONG AND NORTH OF
I-90.

THIS STORM SYSTEM IS EXPECTED TO PRODUCE QUITE A WINTRY MIX AND
WILL DEFINITELY HAVE AN IMPACT ON THE REGION WITH THE BIGGEST
CONCERN BEING THE FREEZING RAIN/SLEET ACCUMULATIONS LATE SATURDAY
NIGHT INTO SUNDAY MORNING. FEELING IS THAT A WINTER WEATHER ADVISORY
WILL BE NEEDED AND WILL PASS THIS CONCERN ONTO THE NIGHT SHIFT FOR
FURTHER ASSESSMENT.

.LONG TERM...TUESDAY THROUGH FRIDAY
315 PM CST FRI FEB 8 2013

MAIN FORECAST CONCERN IS PRECIPITATION CHANCES THURSDAY INTO FRIDAY.
THE 08.12Z GFS/GEM/ECMWF ARE IN AGREEMENT IN DIGGING UPPER LEVEL
TROUGH OVER THE UPPER GREAT LAKES REGION THROUGH THE FORECAST
PERIOD. THE MAIN DIFFERENCES BETWEEN THE MODELS ARE TIMING AND
STRENGTH OF SHORTWAVE TROUGH MOVING INTO THE UPPER MIDWEST AND
NORTHERN PLAINS WEDNESDAY NIGHT INTO FRIDAY...AS THE 08.12Z
ECMWF/GFS ARE MUCH MORE PROGRESSIVE THAN THE 08.12Z GEM.
HOWEVER...ALL THE DETERMINISTIC MODELS SUGGEST DECENT LIFT AND
SATURATION IN ASSOCIATION WITH SHORTWAVE TROUGH AND WILL INCREASE
CHANCES OF PRECIPITATION FOR THURSDAY INTO FRIDAY. THE 08.12Z
GFS/ECMWF INDICATE WARMER AIR FILTERING AHEAD OF THE SHORTWAVE
TROUGH AND CAUSE PRECIPITATION TYPE CONCERNS DURING THE DAY
THURSDAY...ESPECIALLY OVER THE SOUTHERN PARTS OF THE FORECAST AREA.
HAVE INTRODUCED RAIN AND SNOW MIX OVER THE SOUTHERN PORTIONS OF THE
FORECAST AREA. PRECIPITATION SHOULD BE ALL SNOW OVER THE NORTHERN
PORTIONS OF THE FORECAST AREA.

.AVIATION...TONIGHT AND SATURDAY
549 PM CST FRI FEB 8 2013

THE MAIN FOCUS AT THE TAF SITES TONIGHT IS WITH THE MVFR STRATUS
THAT COVERS MUCH OF SOUTHERN MINNESOTA AND HOW FAST IT WILL COME
BACK TO THE NORTH AND GET INTO LSE. THE EASTERN EDGE OF THIS
1-2KFT DECK IS RIGHT OVER RST AND APPEARS TO HAVE STALLED OUT. AS
LOW LEVEL WINDS SPEED UP OUT OF THE SOUTH TONIGHT...THIS LOW LEVEL
MOISTURE WILL PUSH BACK TO THE NORTH WITH AN EXPECTED ARRIVAL INTO
LSE AROUND 6Z. CEILINGS ARE EXPECTED TO DROP TO IFR AT RST TONIGHT
AS THE LOW LEVEL MOISTURE INCREASES. FOG DOES NOT LOOK LIKE IT
WILL FORM AT LSE/RST WITH THE LOW CLOUD DECK LIKELY KEEPING
TEMPERATURES UP ENOUGH TO PREVENT THE FOG FROM FORMING. WILL ALSO
HAVE TO WATCH FOR SOME DRIZZLE TO FORM AS WELL...BUT CONFIDENCE IS
NOT HIGH ENOUGH TO PUT THAT IN THE FORECAST. WINDS PICK UP
TOMORROW MORNING AS A STRENGTHENING STORM SYSTEM DEVELOPS IN THE
PLAINS. THIS SYSTEM WILL LIKELY BRING A WINTRY MIX OF
PRECIPITATION INTO THE REGION TOMORROW NIGHT AND LAST INTO SUNDAY.

.HYDROLOGY...
315 PM CST FRI FEB 8 2013

EXPECTING RAINFALL AMOUNTS OF AROUND 1/2 INCH TO FALL ON EXISTING
SNOW PACK AND FROZEN GROUNDS SUNDAY. THIS WILL LIKELY RESULT IN
RUNOFF INTO AREA STREAMS...CREEKS AND RIVERS. AS A RESULT...PLAN FOR
RISES ON AREA RIVER WAYS. IF RAINFALL SHOULD BECOME MORE
SIGNIFICANT...RIVER FLOODING WILL BECOME AN INCREASING CONCERN. THE
POSSIBILITY FOR ICE JAMS WILL ALSO HAVE TO BE MONITORED. IN
ADDITION...LOCALIZED SIGNIFICANT PONDING OF WATER CAN BE EXPECTED ON
AREA ROADWAYS WHERE DRAINAGE IN CONSTRICTED.

.ARX WATCHES/WARNINGS/ADVISORIES...
315 PM CST FRI FEB 8 2013

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

SHORT TERM...DAS
LONG TERM....DTJ
AVIATION...HALBACH
HYDROLOGY....DAS

AREA FORECAST DISCUSSION

NWS LA CROSSE WI

1153 AM CST THU FEB 7 2013

.SHORT TERM...TODAY THROUGH SATURDAY
344 AM CST THU FEB 7 2013

MAIN FORECAST CONCERNS ARE ON FREEZING RAIN AND SNOW TODAY. FOCUS
THEN TURNS TO SYSTEM IMPACTING THE AREA LATE SATURDAY INTO
SUNDAY...BRINGING ANOTHER ROUND OF MIXED PRECIPITATION TO THE AREA.

LATEST SURFACE OBSERVATIONS SHOWED A LOW CLOUD DECK OVER NORTH
CENTRAL INTO CENTRAL WISCONSIN WITH CLOUD BASES AROUND 300 FT. THIS
LOW CLOUD DECK WAS PRODUCING SOME LIGHT FREEZING DRIZZLE ACROSS
NORTH CENTRAL WISCONSIN. FURTHER TO THE SOUTH...PERIODS OF FREEZING
RAIN AND SLEET CONTINUE IN FAR SOUTHWEST WISCONSIN INTO PORTIONS OF
NORTHEAST IOWA PRODUCING ICY ROADS. THERE HAS BEEN A BREAK IN THE
PRECIPITATION ACROSS SOUTHEAST MINNESOTA INTO WEST CENTRAL
WISCONSIN. AREAS OF FOG WERE DEVELOPING ACROSS SOUTHERN MINNESOTA
WITH VISIBILITIES FALLING TO AROUND 1/2 MILE OR LESS.

UPPER LEVEL TROUGH WILL MOVE EAST OUT OF THE DAKOTAS EARLY THIS
MORNING...PUSHING INTO THE UPPER MISSISSIPPI RIVER VALLEY LATE THIS
MORNING INTO EARLY THIS AFTERNOON. MEANWHILE...A SURFACE TROUGH
EXTENDING FROM CENTRAL IOWA NORTH INTO WESTERN WISCONSIN WILL DEEPEN
BEFORE SHIFTING EAST AND WRAPPING INTO A STRONG LOW. MESOSCALE
MODELS CONTINUE TO SHOW A FREEZING DRIZZLE SIGNATURE ALONG AND EAST
OF THE MISSISSIPPI RIVER LATE THIS MORNING INTO THE AFTERNOON HOURS
WITHIN THE INVERTED TROUGH. FORECAST SOUNDINGS SHOW A SATURATED
LAYER FROM JUST ABOVE THE SURFACE THROUGH 4KFT. THERE IS WEAK LIFT
WITHIN THIS LAYER...BETWEEN 950 AND 850 MB. THIS WILL BE ENOUGH TO
SUPPORT LIGHT FREEZING DRIZZLE. WILL HAVE TO KEEP A CLOSE WATCH ICE
ALOFT ACROSS SOUTHWEST INTO CENTRAL WISCONSIN...WHERE THERE IS THE
POTENTIAL TO SEE ACCUMULATING SNOW. 06Z NAM GUIDANCE SUGGESTS
SATURATION WILL BE DEEP ENOUGH OVER THESE AREAS FOR ICE ALOFT AND
POSSIBLY 1 TO 2 INCHES OF SNOW. PLAN ON HIGH TEMPERATURES TODAY
RANGING FROM AROUND 30 OVER NORTH CENTRAL WISCONSIN TO THE MID 30S
OVER NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN.

HIGH PRESSURE WILL BUILD INTO THE AREA LATE TONIGHT INTO FRIDAY
MORNING. A POTENT TROUGH IS EXPECTED TO DIVE SOUTHWEST CONUS AND
WILL TAKE AIM ON THE UPPER MIDWEST LATE FRIDAY INTO SATURDAY. PLAN
ON PARTLY TO MOSTLY SUNNY SKIES ON FRIDAY WITH HIGHS RANGING FROM
THE MID 20S OVER NORTH CENTRAL WISCONSIN TO AROUND 30 OVER NORTHEAST
IOWA. THE HIGH WILL SLIDE EAST OF THE REGION ON SATURDAY AS THE
TROUGH EJECTS OUT OF THE ROCKIES INTO THE CENTRAL PLAINS. THE TROUGH
IS EXPECTED TO CLOSE INTO AN UPPER LOW OVER NEBRASKA SATURDAY
EVENING AND LIFT INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION LATE
SATURDAY NIGHT INTO SUNDAY. WARM AIR ADVECTION WILL KICK IN SATURDAY
NIGHT AHEAD OF THE APPROACHING LOW. TEMPERATURES SHOULD REMAIN
NEARLY STEADY DURING THE EVENING THEN SLOWLY RISE OVERNIGHT. 07.00
MEDIUM RANGE MODELS ARE IN REASONABLE AGREEMENT SUNDAY INTO SUNDAY
NIGHT TAKING THE POTENT LOW OVER OVER CENTRAL MINNESOTA INTO
NORTHWEST WISCONSIN. STRONG LIFT AND WARM AIR ADVECTION WILL MOVE
INTO THE FORECAST AREA AHEAD OF THE LOW LATE SATURDAY NIGHT INTO
SUNDAY MORNING. PRECIPITATION IS EXPECTED TO START OUT AS A
SNOW/SLEET MIX SWITCHING OVER TO FREEZING RAIN THEN EVENTUALLY OVER
TO RAIN LATE IN THE NIGHT AS WARM AIR SURGES IN. SURFACE
TEMPERATURES WILL BE COLD ENOUGH THAT THE RAIN WILL FREEZE UPON
CONTACT EVEN THOUGH AIR TEMPERATURES ARE WARMING ABOVE FREEZING.

.LONG TERM...SUNDAY THROUGH WEDNESDAY
344 AM CST THU FEB 7 2013

PRECIPITATION WILL SWITCH OVER TO MAINLY RAIN SUNDAY AFTERNOON AS
THE LOW MOVES INTO NORTHWEST WISCONSIN. THE LOW IS EXPECTED TO
MOVE INTO NORTHEAST WISCONSIN SUNDAY NIGHT WITH COLDER AIR
WRAPPING INTO THE AREA ON THE BACK SIDE OF THE LOW. PRECIPITATION
WILL SWITCH OVER TO SNOW AS THE LOW LIFTS NORTHEAST. A TRAILING
TROUGH WILL LINGER OVER THE REGION ON MONDAY AS THE LOW CONTINUES
ITS NORTHEAST MOVEMENT INTO EASTERN UPPER MICHIGAN. SNOW CHANCES
WILL CONTINUE THROUGH THE DAY ON MONDAY AS THE TROUGH DRIFTS
THROUGH THE AREA. WEAK HIGH PRESSURE IS EXPECTED TO BUILD INTO THE
REGION TUESDAY INTO WEDNESDAY BRINGING DRY AND QUIET WEATHER TO
THE AREA. PLAN ON HIGHS IN THE LOWER 20S TO AROUND 30 ON
TUESDAY...WARMING SLIGHTLY INTO THE UPPER 20S TO LOWER 30S BY
WEDNESDAY.

.AVIATION...THROUGH 18Z FRIDAY
1120 AM CST THU FEB 7 2013

MAIN FORECAST CONCERNS THROUGH THE TAF PERIOD IS THE LIFR
CONDITIONS OCCURRING AT RST TAF SITE. LATEST VISIBLE SATELLITE
IMAGERY INDICATING LOW STRATUS CLOUD DECK ENCOMPASSING THE UPPER
MIDWEST REGION WITH 17Z METAR OBSERVATIONS REPORTING CEILING
HEIGHTS FROM TWO HUNDRED FEET TO 1100 FEET ACROSS PORTIONS OF
SOUTHEAST MINNESOTA AND WESTERN WISCONSIN. THE 07.15Z RAP AND
07.12Z GFS/NAM BUFKIT SOUNDINGS INDICATING THE NEAR SURFACE
BOUNDARY LAYER TO REMAIN SATURATED THROUGH THE OVERNIGHT
HOURS...EXPECT LOW CEILINGS AND LIFR CONDITIONS TO PREVAIL AT RST
THROUGH 02Z FRIDAY AND IFR CONDITIONS THROUGH 09Z FRIDAY...LSE
SHOULD EXPERIENCE MVFR CONDITIONS THROUGH 10Z FRIDAY. HIGH
PRESSURE WILL BUILD INTO WESTERN WISCONSIN AND EASTERN MINNESOTA
AFTER 10Z FRIDAY AND ALLOW FOR DRIER AIR TO ADVECT INTO THE AREA.
WITH THIS...LOW STRATUS DECK WILL ERODE AND VFR CONDITIONS SHOULD
PREVAIL AT BOTH RST AND LSE TAF SITES AFTER 09Z-10Z FRIDAY.
FREEZING DRIZZLE OR LIGHT SNOW IS POSSIBLE AT BOTH TAF SITES
THROUGH EARLY THIS EVENING...HOWEVER PRECIPITATION WILL REMAIN
VERY LIGHT AND HAVE KEPT OUT OF TAFS.

.ARX WATCHES/WARNINGS/ADVISORIES...
344 AM CST THU FEB 7 2013

WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ017-
029-032>034-041>044-053>055-061.

MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ079-
086>088-094>096.

IA...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
IAZ008>011-018-019-029-030.

SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...DTJ

AREA FORECAST DISCUSSION

NWS LA CROSSE WI

1149 PM CST WED FEB 6 2013

.SHORT TERM...TONIGHT
553 PM CST WED FEB 6 2013

DRYING AND SUBSIDENCE HAS COME IN BEHIND THE BAND OF SNOW THAT
IMPACTED TAYLOR/CLARK COUNTIES THE PAST FEW HOURS. THIS DRYING AND
SUBSIDENCE HAS EFFECTIVELY ENDED MUCH OF THE PRECIPITATION ACROSS
SOUTHEAST MINNESOTA AND IN REALITY MOST LOCATIONS NORTH OF
INTERSTATE 90. MEANWHILE...AN AREA OF WARM ADVECTION PRECIPITATION
CONTINUES ACROSS NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN.

06.12Z HIRES ARW AND 06.20Z RAP/HRRR RUNS HAVE ALL HAD A DECENT
HANDLE ON THE ONGOING PRECIPITATION TRENDS...KEEPING THE BULK OF
THE PRECIPITATION THIS EVENING ACROSS NORTHEAST IOWA INTO FAR
SOUTHWEST WISCONSIN AND PERHAPS JUNEAU/ADAMS COUNTIES. MUCH OF
SOUTHEAST MINNESOTA INTO BUFFALO...TREMPEALEAU AND LA CROSSE
COUNTIES STAY DRY. AS A RESULT...CONFIDENCE IS JUST NOT HIGH
ENOUGH TO MAINTAIN THE ADVISORY FOR MUCH OF THIS AREA FOR THE
EVENING HOURS. FILLMORE...HOUSTON AND LA CROSSE COUNTIES COULD BE
ON THE VERY EDGE OF HAVING SOME PRECIPITATION DRIFT IN AND
OUT...THOUGH. IN JACKSON/MONROE/JUNEAU/ADAMS/TAYLOR/CLARK...THE
RECENT SNOW HAS HELD TEMPERATURES DOWN...AND WITH HIGHER MOISTURE
APPROACHING FROM THE SOUTH...CONCERNED FREEZING DRIZZLE COULD
DEVELOP AS SUGGESTED BY RAP SOUNDINGS. THUS...HAVE MAINTAINED THE
ADVISORY FOR THIS AREA DURING THE EVENING. AFTER MIDNIGHT AND
EVEN INTO THURSDAY MORNING...CONFIDENCE INCREASES OF BOTH FREEZING
DRIZZLE AND FOG DEVELOPING OVER THE NORTHWEST HALF OF THE FORECAST
AREA...ESPECIALLY TOWARDS LATE IN THE NIGHT...WITH THE POTENTIAL
SUGGESTED OF THE MID CLOUDS CLEARING OUT. WILL REALLY HAVE TO
WATCH VISIBILITIES WITH THE FOG...WHICH IS DISCUSSED MORE IN THE
AVIATION SECTION BELOW.

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
223 PM CST WED FEB 6 2013

THE MAIN FOCUS IN THE EXTENDED PERIOD IS WITH THE SYSTEM THAT MOVES
THROUGH THE REGION SATURDAY NIGHT THROUGH SUNDAY NIGHT. THE 06.12Z
GFS/ECMWF HAVE COME INTO FAIRLY GOOD AGREEMENT WITH A CONTINUED
NORTHWARD SHIFT WITH THE TRACK OF THE LOW. THIS SYSTEM IS CURRENTLY
LOCATED OFF OF THE COAST OF THE PACIFIC NORTHWEST AND WILL STALL OUT
ACROSS THE CENTRAL US ROCKIES EARLY THIS WEEKEND. THE EASTERN
PORTION OF THE TROUGH EJECTS OUT TO THE NORTHEAST INTO THE NORTHERN
PLAINS SATURDAY NIGHT INTO EARLY SUNDAY. THE 06.12Z GFS/ECMWF ARE
AGAIN VERY CONSISTENT WITH THIS RUN FOR TAKING THE CORE OF THE LOW
FROM EASTERN COLORADO SATURDAY NIGHT THROUGH CENTRAL MINNESOTA BY
SUNDAY NIGHT AND THEN INTO THE UPPER GREAT LAKES MONDAY. AT THE
SURFACE...THE LOW IS EXPECTED TO TRACK FROM NORTH CENTRAL IOWA
SUNDAY INTO NORTHERN WISCONSIN BY SUNDAY NIGHT. THIS LEADS TO THE
REGION BEING IN THE WARM SECTOR FOR MOST OF THIS SYSTEM WITH RAIN
BEING THE MAIN PRECIPITATION TYPE. THE BIGGEST CONCERN WILL BE AS
THE PRECIPITATION MOVES IN FROM THE SOUTH SATURDAY NIGHT MIXED
PRECIPITATION TYPES POSSIBLE. DETAILS WILL EMERGE OVER THE NEXT FEW
DAYS...BUT 06.12Z GFS BUFKIT SOUNDINGS SHOW A WARM LAYER OVER A SUB
FREEZING NEAR SURFACE LAYER THAT WOULD LEAD TO A MIX OF SLEET AND
FREEZING RAIN AT THE ONSET. THE LOW LEVEL PROFILE THEN WARMS ENOUGH
THAT MUCH OF SUNDAY SHOULD JUST BE RAIN BEFORE COLDER AIR MOVES IN
ON THE BACK SIDE SUNDAY NIGHT INTO MONDAY.

NOT MUCH IN THE WAY OF COLD AIR ADVECTION ON THE BACK SIDE OF THIS
AMPLIFIED SYSTEM...SO THERE SHOULD NOT BE MUCH OF A COOL DOWN AFTER
THE SYSTEM PASSES. HIGH PRESSURE BUILDS IN AND CONDITIONS SHOULD
REMAIN DRY THROUGH MID WEEK.

.AVIATION...THROUGH 06Z FRIDAY
1148 PM CST WED FEB 6 2013

LOW LEVEL DRY AIR BETWEEN JUST ABOVE THE SURFACE AND 4000 FT AGL
HAS KEPT CONDITIONS VFR THUS FAR. THIS SHOULD CONTINUE FOR THE
NEXT 4 HOURS OR SO...WHICH IS WHEN A COLD FRONT CURRENTLY PASSING
THROUGH MINNEAPOLIS IS EXPECTED TO REACH THE TAF SITES. ONE
CONCERN WHICH WILL HAVE TO BE WATCHED IS THE CURRENT ALTOSTRATUS
CLEARING OUT NORTH OF KRST. FAIRBAULT AT 1134 PM DROPPED TO 1/2SM
QUICKLY. ANTICIPATING RIGHT NOW THAT THE ALTOSTRATUS WILL STAY IN
PLACE...PREVENTING FOG FORMATION. IN THE WAKE OF THE COLD
FRONT...CEILINGS QUICKLY DROP TO MVFR AND A LITTLE FARTHER NORTH
DROP TO IFR. VISIBILITIES ALSO DROP TO MVFR. ANTICIPATING THE
COMBINATION OF ADDITIONAL DIURNAL COOLING AND THE COLD AIR RUNNING
INTO A MORE MOIST AIRMASS OVER THE AREA TO RESULT IN LOWER
CEILINGS AND VISIBILITIES WHEN THE FRONT PASSES THROUGH THE TAF
SITES. THUS...HAVE BOTH SITES DROPPING TO AT LEAST IFR IN
VISIBILITY AND CEILING BY 14Z. IN ADDITION...WEAK LOW LEVEL LIFT
MAY PROMOTE -FZDZ DEVELOPMENT BEHIND THE FRONT THROUGHOUT MUCH OF
THE DAY. THIS LIFT EXITS LATE IN THE DAY...BUT COLD ADVECTION
PERSISTS...WHICH SHOULD ALLOW CEILINGS AND VISIBILITIES TO RISE
THROUGH THE EVENING. HAVE KEPT MVFR CEILINGS IN UNTIL
06Z...THOUGH...WITH MOISTURE TRAPPED ON THE COLD FRONTAL
INVERSION.

.ARX WATCHES/WARNINGS/ADVISORIES...
1137 PM CST WED FEB 6 2013

WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THURSDAY FOR WIZ017-029-
034-042>044-053>055-061.

WINTER WEATHER ADVISORY UNTIL 6 PM CST THURSDAY FOR WIZ032-033-
041.

MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THURSDAY FOR MNZ079-
086>088-094>096.

IA...WINTER WEATHER ADVISORY UNTIL 6 PM CST THURSDAY FOR IAZ008>011-
018-019-029-030.

SHORT TERM...AJ
LONG TERM...DAS
AVIATION...AJ

AREA FORECAST DISCUSSION

NWS GREEN BAY WI

1041 PM CST WED FEB 6 2013

UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE

.UPDATE...HAVE ALREADY UPDATED THE GRIDS/ZFP/SPS/WSW/HWO.

MAIN BAND OF SNOW THAT BROUGHT 1-3 INCHES OF SNOW TO THE FORECAST
AREA WAS TAPERING OFF OVER FAR NE WI. SYNOPTIC SCALE FORCING IS
EXPECTED TO WEAKEN OVERNIGHT...AND MID-LEVEL DRY AIR IS FCST TO
MOVE INTO THE RGN. ALTHOUGH SCT/OCNL LIGHT SNOW MAY CONTINUE
OVERNIGHT...ESPECIALLY IN OUR SOUTHERN COUNTIES...THE MAIN PCPN
TYPE IS EXPECTED TO TRANSITION TO FREEZING DRIZZLE. THIS THREAT
WILL JUSTIFY KEEPING THE ADVISORY GOING THROUGH THE NIGHTTIME HOURS.

ON THURSDAY...STRONG UPPER DIVG DUE TO THE RRQ OF AN UPPER JET AND
SHARP UPPER TROF WILL CAUSE SIGNIFICANT SNOW TO REDEVELOP ACROSS
THE SE HALF OF THE FORECAST AREA. ADDITIONAL ACCUMS OF 3 TO 5
INCHES ARE EXPECTED ACROSS THE FOX VALLEY/LKSHR AREAS FROM LATE
THURSDAY MORNING THROUGH THURSDAY EVG...WITH 1 TO 3 INCHES ACROSS
THE NW PORTION OF THE ADVISORY AREA.

HAVE ADJUSTED THE SEGMENTS OF THE WSW TO ACCOUNT FOR THE DIFFERENCES
IN EXPECTED SNOWFALL ACCUMS ON THURSDAY.

KIECKBUSCH
&&

.PREV DISCUSSION...ISSUED AT 540 PM CST WED FEB 6 2013...

SHORT TERM...TONIGHT AND THURSDAY.

WINTER WEATHER ADVISORY FOR SNOW AND FREEZING DRIZZLE IS THE MAIN
CONCERN DURING THIS PART OF THE FORECAST. MODELS SHOWED
SIGNIFICANT UPPER LEVEL DIVERGENCE ACROSS MUCH OF THE FORECAST
AREA LATE THIS AFTERNOON AND TONIGHT. THIS WAS ASSOCIATED WITH
THE RIGHT ENTRANCE REGION OF A 120+ KNOT 300MB JET MAX. STRONG
UPPER DIVERGENCE ASSOCIATED WITH A WEAKER JET MAX RETURNS TO THE
AREA ON THURSDAY. THE COMBINATION OF LIFT FROM WARM ADVECTION AND
UPPER DIVERGENCE WAS PRODUCING A BAND OF SNOW THAT EXTENDED FROM
THE MINNESOTA ARROWHEAD SOUTHEAST TO SOUTHERN WISCONSIN. SNOWFALL
IN THIS BAND WAS RATHER HEAVY SO IT SHOULD PRODUCE A QUICK
ACCUMULATION OF AN INCH OR TWO AS IT PASSES. RADAR SHOWED A BAND
OF ECHOES ACROSS NORTHERN IOWA BUT SURFACE OBSERVATIONS WERE NOT
INDICATING PRECIPITATION WITH THIS FEATURE. THE 18Z RUC SHOWED QPF
IN THIS AREA SPREADING NORTHEAST INTO CENTRAL AND EASTERN
WISCONSIN OVERNIGHT. MODELS HINTED AT SOME MID LEVEL DRYING
AFTER MIDNIGHT SO HAVE FREEZING DRIZZLE MENTIONED ALONG WITH THE
SNOW.

AN INVERTED SURFACE TROUGH AXIS IS EXPECTED TO PASS THROUGH THE
AREA ON THURSDAY. A 500MB SHORT WAVE APPROACHING THE STATE WILL
COMBINE WITH THE UPPER DIVERGENCE AND SURFACE BOUNDARY TO PRODUCE
MORE SIGNIFICANT SNOWFALL...MAINLY ACROSS EAST CENTRAL WISCONSIN.
TIME/HEIGHT SECTIONS FROM THE 12Z NAM/12Z GFS/09Z SREF DID NOT
INDICATE FREEZING PRECIPITATION FOR ANY OF THE LOCATIONS IN THE
AREA DURING THE SHORT TERM...THOUGH THEY DID IN THE MSN AND MKE
AREAS. HPC WINTER PRECIPITATION GUIDANCE KEPT ANY MEASURABLE
FREEZING PRECIPITATION SOUTH OF THE AREA WITH 24 HOUR TOTALS
THROUGH 00Z FRIDAY OF 6+ INCHES FROM JUST EAST OF GREEN BAY AND
THE FOX CITIES TO LAKE MICHIGAN.

LONG TERM...THU NGT THRU NEXT WED. A NEARLY ZONAL FLOW ACROSS THE
CONUS AT THE ONSET TO TRANSITION TO AN AMPLIFIED FLOW THIS WEEKEND
AS A LARGE UPR RDG BUILDS OFF THE WEST COAST AND A DOWNSTREAM
LONGWAVE TROF SETS UP OVER THE ROCKIES INTO THE CNTRL CONUS. MDLS
CONT TO SHOW A MAJOR SYSTEM WL LIFT NE FROM CO INTO THE GREAT
LAKES SAT NGT INTO MON BRINGING SNOW AND MIXED PCPN TO NE WI. MEAN
FLOW EVENTUALLY BECOMES SPLIT OVER THE ERN PACIFIC WITH THE UPR
TROF SHIFTING EAST. HOWEVER...A SFC HI SHOULD KEEP THE WEATHER
RELATIVELY QUIET WITH TEMPS OVERALL SLIGHTLY ABOVE NORMAL.

LIGHT SNOW TO LINGER INTOI THU EVENING AS THE SHORTWAVE TROF MOVES
THRU WI. CONCERNED ABOUT ERN WI WHERE LIFT IS STRONGER AND WINDS
JUST ABOVE THE SFC ARE FCST TO BE N-NE. MAY NEED TO RAISE POPS A
BIT...ESPECIALLY IN THE EAST WHERE LAKE ENHANCEMENT TO TAKE PLACE
AND THIS COULD ADD UP TO AN INCH OF ADDITIONAL ACCUMULATION. PCPN
WL TAPER OFF FROM WEST TO EAST DURING THE OVRNGT HOURS...ALTHO THE
LAKESHORE MAY NOT SEE THE SNOW COME TO A COMPLETE END TIL CLOSE TO
DAYBREAK. HI PRES BUILDING INTO THE WRN GREAT LAKES LATER THU NGT
COULD BEGIN TO BREAK UP THE CLOUDS ACROSS CNTRL WI AND MAY NEED TO
LWER TEMPS A BIT TO COMPENSATE. THIS AREA OF HI PRES WL BE SITUATED
OVER WI ON FRI PROVIDING FOR PLENTY OF SUNSHINE...LIGHT WINDS AND
TYPICAL TEMPS FOR EARLY FEBRUARY. LOOK FOR READINGS TO GENERALLY
REACH THE 25-30 DEG RANGE OVER ALL OF NE WI.

THE HI PRES BEGINS TO SLIDE TO OUR EAST FRI NGT ALLOWING A RETURN
FLOW TO DEVELOP OVER WI. THE ONSET OF WEAK ISEN LIFT SHOULD BRING
SOME HI CLOUDS INTO THE FCST AREA...HOWEVER STILL EXPECT TEMPS TO
DROP OFF DUE TO FRESH SNOW AND LIGHT WINDS. PREFER THE COLDER SIDE
OF GUIDANCE AND HAVE SIGNIFICANTLY CHOPPED TEMPS INTO THE SINGLE
DIGITS/LOWER TEENS. AS THE LONGWAVE TROF CHUGS ACROSS THE ROCKIES
ON SAT...LEE-SIDE CYCLOGENESIS TO TAKE PLACE OVER SE CO AS A SFC
LOW QUICKLY INTENSIFIES. MEANWHILE...THE SFC HI CONTS TO PULL
FARTHER EAST AND THE SOUTH WINDS STEADILY INCREASE AS THE PRES
GRADIENT TIGHTENS. THESE SOUTH WINDS WL ALSO HELP BRING GULF
MOISTURE NWD...SO WE SHOULD SEE CLOUDS ON THE INCREASE DURING THE
DAY. MAX TEMPS ARE EXPECTED TO REACH NEAR THE 30 DEG MARK DESPITE
THE CLOUDS.

AS A 110+ KT UPR JET ROUNDS THE BASE OF THE UPR TROF...THE SFC LOW
IS FCST TO START MOVING NE INTO THE CNTRL PLAINS SAT NGT AND REACH
THE MIDWEST (VICINITY NW IA) ON SUNDAY. LOW-LEVEL MOISTURE CONTS
TO STREAM INTO WI WITH A WRMFNT LIFTING TO THE WI/IL BORDER BY
SUNDAY AFTERNOON. MID-LEVEL FORCING (BOTH Q-G AND FRONTOGENETICAL)
INCREASE DURING THIS PERIOD OVER THE REGION WITH THE LEFT EXIT
REGION OF THE UPR JET ADDING LIFT. EXPECT TO SEE PCPN GRADUALLY
OVERSPREAD WI ON SUNDAY...BUT WHAT TYPE OF PCPN? WHILE MOST OF THE
MDLS ARE GETTING CLOSER TO A FINAL TRACK SOLUTION (EXCEPT THE GEM
WHICH REMAINS SOUTH)...THE THERMAL FIELDS VARY BETWEEN THE WARMER
GFS AND THE COOLER ECWMF/UKMET. DIFFICULT TO DETERMINE WHAT THE
SFC TEMPS TO BE AT ONCE THE PCPN BEGINS...AS THIS WOULD PLAY A
LARGE ROLE IN DETERMINING RAIN VS. FREEZING RAIN VS. SNOW. IN
ESSENCE...IT IS JUST TOO EARLY TO TRY AND PINPOINT PCPN TYPES AT
THIS TIME...OTHER THAN N-CNTRL WOULD HAVE THE BEST CHC OF SEEING
ALL SNOW AND E-CNTRL WI WOULD HAVE THE BEST CHC OF SEEING MORE
RAIN THAN SNOW WITH A MIX IN BETWEEN.

SNOW/MIXED PCPN WL CONT SUNDAY NGT AS THE SFC LOW TRACKS NE INTO
N-CNTRL WI WITH THE BETTER SNOW ACCUMULATION OCCURRING OVER THE NW
1/4 OF WI. THIS WOULD LIKELY CLIP PARTS OF N-CNTRL WI...BUT FOR
MOST OF THE FCST AREA...TOO MUCH OF A MIX WL LIMIT SNOW AMOUNTS.
AS THE SFC LOW PULLS AWAY ON MON AND COLDER AIR GETS PULLED SWD...
ANY LINGERING MOISTURE WOULD TRANSITION BACK TO ALL SNOW. SINCE
DEEPER MOISTURE TO ALREADY HAVE EXITED...DO NOT EXPECT TO SEE MUCH
ADDITIONAL ACCUMULATION ON MON...ESPECIALLY IF SOME FREEZING
DRIZZLE MIXES IN. OTHER THAN SOME LIGHT LAKE EFFECT SNOW SHWRS
OVER VILAS CNTY MON NGT...THE WEATHER BECOMES FAIRLY TRANQUIL WITH
PERHAPS SOME FLURRIES ON TUE AS THE POSITIVE-TILTED UPR TROF MOVES
THRU THE GREAT LAKES. HI PRES PASSING TO OUR SOUTH ON WED WL BRING
A DRY DAY WITH TEMPS WARMING UP A BIT.
&&

.AVIATION...THERE WILL BE A LULL IN THE SNOW ACCUMULATION
OVERNIGHT THROUGH LATE THURSDAY MORNING...BUT OCNL FREEZING
DRIZZLE AND LIGHT SNOW WILL CONTINUE DURING THIS PERIOD. THE SNOW
SHOULD PICK UP AGAIN BY MIDDAY THURS...AND BE HEAVIEST OVER THE
FOX VALLEY/LKSHR AREAS DURING THE AFTERNOON. IFR CONDITIONS
WILL PREVAIL LATE TONIGHT INTO THURSDAY MORNING...AND CONTINUE
OVER THE FOX VALLEY AND LAKESHORE AREAS WITH THE HEAVIER SNOW
DURING THE AFTERNOON.

KIECKBUSCH
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM CST THURSDAY FOR WIZ013-
020>022-030-031-035>040-045-048>050-073-074.

AREA FORECAST DISCUSSION

NWS TUCSON AZ

910 PM MST FRI FEB 8 2013

.SYNOPSIS...A PACIFIC STORM SYSTEM WILL BRING COLDER TEMPERATURES
WITH RAIN AND SNOW SHOWERS SATURDAY. EXPECT COLD TEMPERATURES WITH A
FEW SHOWERS TO START THE NEW WEEK FOLLOWED BY A STRONG WARMING TREND
DURING THE MIDDLE OF THE WEEK.

.DISCUSSION...DEEP UPPER LOW PRESSURE SYSTEM OVER THE GREAT BASIN
REGION EXTENDING INTO SRN CALIFORNIA AT THIS TIME. IR SATELLITE
IMAGERY INDICATES MOSTLY CLEAR SKIES ACROSS MUCH OF PIMA/SE PINAL
COUNTIES WITH MOSTLY CLOUDY SKIES ELSEWHERE. 08/21Z RUC HRRR DEPICTS
PRECIP TO DEVELOP ACROSS WRN PIMA COUNTY AROUND 05Z-07Z SATURDAY...
THEN PRECIP IS PROGGED TO MOVE EWD INTO THE TUCSON METRO AREA AROUND
1030Z-1100Z SATURDAY. THIS TIMING IS SLIGHTLY FASTER VERSUS THE
09/00Z NAM12. HOWEVER...HAVE NOTED A MARKED INCREASE IN POPS VIA THE
09/00Z NAM12 VERSUS PREVIOUS NAM12 SOLUTIONS.

BASED ON THE RUC HRRR AND NAM...SEE NO REASON TO MAKE ANY CHANGES TO
THE OFFICIAL FORECAST AT THIS TIME. THUS...WILL CONTINUE WITH A
WINTER WEATHER ADVISORY FOR ELEVATIONS ABOVE 4000 FEET FROM 5 AM TO
5 PM MST SATURDAY. MUCH COLDER SAT WITH FORECAST HIGH TEMPS TO BE
ABOUT 15-20 DEGS LOWER VERSUS TEMPS ACHIEVED THIS AFTERNOON.

PLEASE REFER TO THE PREVIOUS DISCUSSION SECTION FOR ADDITIONAL
DETAIL.

.PREV DISCUSSION...MID LEVEL DYNAMICS AND COLD AIR FROM STRONG LOW
PUSHING INTO ARIZONA TONIGHT AND SATURDAY. MAIN TROUGH INFLECTION
WILL COME TOGETHER WITH MOISTURE MAINLY AFTER 12Z SATURDAY FOR OUR
PART OF THE STATE WITH A SIGNIFICANT UPSLOPE COMPONENT. 18Z NAMDNG5
AND 12Z ECMWF LOOK SOLID AND CONTINUE TO HANDLE THINGS WELL. LATEST
HRRR SHOWING ISOLATED DEVELOPMENT WEST AND NORTHWEST OF TUCSON
BETWEEN 04Z-08Z WHICH FITS WELL.

SHOWERS INCREASING FROM THE WEST DURING THE DAY SATURDAY. NOT
EXCESSIVE STORM TOTAL PRECIP WITH QPF GENERALLY RANGING FROM .15 IN
VALLEYS TO .5 IN MOUNTAINS. COLD AIR ALREADY PUSHING IN TONIGHT AND
BY THE TIME THE BEST PRECIP GETS HERE AFTER 12Z SNOW LEVELS ARE
EXPECTED TO RANGE FROM 3000 TO 4000 FEET ACROSS MOST OF THE AREA. A
WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR SATURDAY ABOVE 4000
FEET...EVEN THOUGH HIGHER ELEVATIONS MAY STRUGGLE TO END UP WITH
ENOUGH SNOW TO MEET CRITERIA. THE PRIME AREA OF CONCERN IS 3500 TO
5500 FEET. PLEASE SEE PHXWSWTWC FOR DETAILS.

SOME CLEARING SATURDAY NIGHT INTO SUNDAY MORNING WITH SOLID COLD AIR
IN PLACE...WITH WIDESPREAD NEAR OR BELOW FREEZING TEMPERATURES AREAS
OF FROST ARE A CONCERN.

ON MONDAY A REINFORCING SHOT OF COLD AIR WITH A SYSTEM DIGGING DOWN
THE BACK SIDE OF THE MEAN TROUGH POSITION FROM THE NORTH. RESIDUAL
BOUNDARY LAYER MOISTURE SHOULD GIVE IT ENOUGH TO GENERATE A FEW MORE
RAIN AND SNOW SHOWERS ACROSS THE AREA AS SNOW LEVELS REMAIN LOW.

OVERALL SATURDAY THROUGH TUESDAY WE EXPECT A SUSTAINED PERIOD OF
COLD TEMPERATURES WITH AT LEAST 4 DAYS WHERE TEMPERATURES DON`T
CLIMB OUT OF THE 50S. SOME CONCERNS WITH LOW TEMPERATURES...WITH THE
POTENTIAL OF A WIDESPREAD FREEZE FROM TUCSON THROUGH THE LOWER
DESERTS...AND WIDESPREAD HARD FREEZE AT HIGHER ELEVATION LOCATIONS
FROM SUNDAY MORNING THROUGH WEDNESDAY MORNING.

.AVIATION...SCT -SHRA TO DEVELOP WEST OF KTUS 06Z-08Z SATURDAY...
THEN SCT-NMRS -SHRA AND HIGHER TERRAIN -SHSN TO MOVE EWD ACROSS SE
AZ SATURDAY. BULK OF PRECIP TO END AROUND 10/00Z. BEST CHANCE OF
PRECIP FOR KTUS WILL BE BETWEEN 09Z-18Z SATURDAY. OTHERWISE...
CLOUD DECKS LOWERING TO GENERALLY 5-9K FT AGL AROUND 08Z-10Z
SATURDAY AND CONTINUING INTO SATURDAY AFTERNOON. CLOUDS DECREASING
SATURDAY EVENING. SURFACE WIND SWLY/WLY 10-20 KTS WITH GUSTS TO
AROUND 30 KTS THRU SATURDAY AFTERNOON FOLLOWED BY DECREASING WIND
SATURDAY EVENING. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

.FIRE WEATHER...SHOWERS WILL DEVELOP LATE TONIGHT AND CONTINUE INTO
SATURDAY WITH THE SNOW LEVEL DROPPING TO NEAR 3000 FT. ANOTHER STORM
SYSTEM WILL RESULT IN A SLIGHT CHANCE OF SHOWERS ON MONDAY MAINLY TO
THE EAST OF TUCSON AND OVER HIGHER TERRAIN. DAYTIME TEMPERATURES
SATURDAY THROUGH TUESDAY WILL BE 10-15 DEGREES COOLER THAN NORMAL.
WARMER CONDITIONS WILL RETURN TO THE AREA LATE NEXT WEEK.

.TWC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 AM TO 5 PM MST SATURDAY FOR
AZZ503-504-506>515 ABOVE 4000 FEET.

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

AREA FORECAST DISCUSSION

NWS DENVER/BOULDER CO

1010 PM MST FRI FEB 8 2013

.UPDATE...

.SHORT TERM...FEW CHANGES NECESSARY TO EVENING FORECAST. SNOW
SHOWERS SLOW TO DEVELOP IN THE NORTH CENTRAL MOUNTAINS AS THE
UPPER LOW AND BEST FORCING STILL WELL UPSTREAM OVER NEVADA AND
WESTERN UTAH. THROUGH THE NIGHT SHOULD SEE A STEADY INFLUX OF MID
AND HIGH CLOUDS OVER THE NORTHEAST PLAINS AND LOWER CLOUDS MTN
AND WESTERN VALLEYS WITH SOUTHWESTERLY FLOW. MEANWHILE GUSTY
SOUTHERLY SFC WINDS ON THE PLAINS...ROUGHLY EAST OF A STERLING TO
LIMON LINE MAY CONTINUE TO BLOW FOR MUCH OF THE NIGHT AT SPEEDS OF
15-30KTS. LASTLY...00Z/NAM SUGGESTS SOME POOLING OF BOUNDARY LAYER
MOISTURE JUST NORTH OF THE DENVER AREA TOWARD DAWN WITH LIGHT
NORTH-NORTHWEST SFC FLOW. HENCE COULD SEE PATCHY SHALLOW FOG IN
THIS AREA...POSSIBLY AS FAR SOUTH AS DIA...BUT PROBABLY FOR ONLY A
FEW HRS ROUND SUNRISE.

.AVIATION...VFR CONDITIONS ANTICIPATED AT DENVER AREA AIRPORTS
THROUGH 11Z TONIGHT. FROM 11Z TO AROUND 14Z THERE IS A SLIGHT
CHANCE DIA COULD SEE SOME SHALLOW FOG NORTH OF THE AIRPORT
MOVING OVER PARTS OF THE AIRPORT. FOG PROBABLY SHALLOW AND THIN
SO OBSCURATION TO VISIBILITY SHOULD BE MINOR. SOUTHERLY WINDS OF
4 TO 12KTS IN THE DENVER AREA EXPECTED TO GRADUALLY SHIFT TO A
LIGHT NORTH-NORTHWEST DIRECTION TOWARDS MORNING WITH A SFC LOW
FORMING ON THE PLAINS EAST OF DENVER.

.PREV DISCUSSION... /ISSUED 405 PM MST FRI FEB 8 2013/

SHORT TERM...UPPER LEVEL TROUGH AND MID LEVEL LOW OVER SOUTHERN
GREAT BASIN WITH STRONG SOUTHWEST FLOW ACROSS COLORADO. WINDS HAVE
BEEN GUSTY ACROSS MUCH OF THE PLAINS WHICH HELPED TO ELEVATE THE
FIRE DANGER. HUMIDITY READINGS WERE IN THE MID AND UPPER TEENS
WHICH KEPT CRITICAL FIRE WEATHER CONCERNS TO A MINIMUM. A WEAK
BOUNDARY EXTENDING FROM EAST OF DENVER TO THE SOUTHERN DENVER
SUBURBS HAS KEPT THE GUSTY WINDS FROM SPREADING NORTH ACROSS THE
DENVER AREA. OVER THE MOUNTAINS... DRY CONDITIONS PREVAILING WITH
SOME MID AND HIGH LEVEL CLOUDS. WINDS WERE A BIT GUSTY ACROSS THE
RIDGES AND SOUTHERN FOOTHILLS. MODELS SHOW THE SYSTEM MOVING EAST
DURING THE EVENING...WITH MID LEVEL LOW OVER SOUTHEAST NEVADA.
SOUTHWEST FLOW ALOFT OVER COLORADO BECOMES A BIT MORE SOUTHERLY.
LATEST RAP SHOWS MID LEVEL ASCENT INCREASING ACROSS MOUNTAINS WITH
LAPSE RATE AROUND 7 C/KM. MOISTURE DOES INCREASE DURING THE
EVENING...WITH THE BETTER MOISTURE HOLDING OFF UNTIL AFTER
MIDNIGHT. SHOULD SEE SOME SHOWERS DEVELOPING INITIALLY OVER THE
HIGHER RIDGES...WITH A BETTER CHANCE AFTER MIDNIGHT WHEN THE
MOISTURE INCREASES. FLOW NOT ALL THAN FAVORABLE FOR SNOWFALL
OVERNIGHT...THOUGH A FEW SPOTS ALONG THE EXTREME WESTERLY SECTIONS
OF THE FORECAST AREAS. ACROSS PLAINS...WINDS TO GRADUALLY AND
BECOME MORE SOUTHWEST WITH VARIABLE MID AND HIGH LEVEL CLOUDS. ON
SATURDAY...MODELS SHOW UPPER TROUGH MOVING INTO THE GREAT BASIN
AND WESTERN COLORADO DURING THE MORNING...THEN ACROSS COLORADO
DURING THE AFTERNOON. THE MID LEVEL LOW SHIFTS FROM SOUTHWEST UTAH
AND SOUTHWEST NEVADA INTO WESTERN COLORADO BY 18Z...THEN OVER
NORTHEAST COLORADO BY 00Z SATURDAY EVENING. MOISTURE INCREASES AND
DEEPENS ACROSS THE MOUNTAINS DURING THE DAY ALONG WITH INCREASING
MID LEVEL QG ACCENT. WITH LAPSE RATES AROUND 7 C/KM EXPECTED...
AIRMASS BECOMES SLIGHTLY UNSTABLE. SO DESPITE THE UNFAVORABLE
OROGRAPHICS...SHOULD SEE SNOW INCREASE ACROSS THE MOUNTAINS BY THE
AFTERNOON. WILL HOIST AN ADVISORY FOR SNOW FOR ZONE 31 BEGINNING
AT 18Z...AND ADVISORIES FOR ZONES 33 AND 34 BEGINNING 21Z. THE
ADVISORIES WILL EXTEND THROUGH SUNDAY MORNING. SNOW AMOUNTS WILL
INITIALLY BE LIGHT BUT SHOULD INCREASE DURING THE AFTERNOON. ALONG
FOOTHILLS...THE TRACK OF THE LOW WILL PROVIDE FOR MORE OF A
DOWNSLOPE NORTHWEST COMPONENT. BUT THERE WILL BE ENOUGH ASCENT TO
HELP OFFSET THE DOWSLOPE FLOW. WILL CONTINUE THE LIKELY POPS WITH
LIGHT SNOW AMOUNTS...THOUGH MAY BE A BIT MORE WIDESPREAD NEAR THE
WYOMING BORDER. ACROSS THE PLAINS...MODELS SHOW NORTHWESTERLIES
SPREADING ACROSS THE AREA LATE MORNING AND AFTERNOON. THIS
DOWNSLOPE WILL INITIALLY KEEP THE PRECIP LIMITED...BUT CHANCES
TO INCREASE BY THE EVENING WHEN THE LIFT GETS GREATER. CURRENT
FORECASTS STILL SEEM ON TRACK AND WILL NOT DEVIATE MUCH. DID
CHANGE THE RAIN/SNOW CHANCES TO ALL SNOW ACROSS NORTHERN WELD AND
NORTHERN LARIMER COUNTIES AS THE COLDER AIR APPEARS TO GET THERE
SOONER.

LONG TERM...MODELS HAVE BEEN PRETTY CONSISTENT WITH THE
DEVELOPMENT OF THE LOW MOVING ACROSS COLORADO INTO NEBRASKA
SATURDAY NIGHT AND SUNDAY. THE ECMWF REMAINS FURTHER SOUTH THAN A
CLUSTER OF OTHER MODELS BY ABOUT 100 MILES...BRINGING THE LOW
ACROSS EAST CENTRAL COLORADO WHILE THE REST GO ACROSS THE
NORTHEAST CORNER. AS A RESULT THE LAST TWO RUNS OF THE ECMWF HAVE
PRODUCE ONE HALF TO ONE INCH OF LIQUID PRECIPITATION OVER THE
CORNER...WHILE OTHER MODELS HAVE LESS WITH THE HEAVY SNOW IN
NEBRASKA. OUR FORECAST HAS BEEN A COMPROMISE AND I SEE LITTLE
REASON TO CHANGE THIS. SO THIS PACKAGE IS PRIMARILY AN UPDATE TO
ISSUE ADVISORIES FOR THE HIGH MOUNTAINS.

AVIATION...BOUNDARY JUST SOUTH AND EAST OF THE DENVER AREA HAS
KEPT THE GUSTY SOUTHERLY WINDS FROM REACHING DEN. SKEPTICAL ABOUT
BOUNDARY MOVING NORTHWARD THROUGH THE EVENING SO WILL KEEP THE
GUSTS OUT OF DEN. WINDS TO DECREASE AT APA DURING THE EVENING WITH
SOUTHERLY DRAINAGE PATTERN DOMINATING ACROSS THE AREA AIRPORTS BY
03Z. VFR TO CONTINUE WITH UNLIMITED CEILINGS. ON SATURDAY...MID
AND HIGH LEVEL MOISTURE TO INCREASE WITH CEILINGS AROUND 10000
FEET AGL BY 18Z WIND TO SHIFT TO THE NORTHWEST AFTER 15Z WITH
SPEEDS AROUND 12 KTS. CEILINGS TO GRADUALLY LOWER DURING THE
AFTERNOON WITH 6000 FEET AGL PREVAILING AROUND 21Z. THERE WILL BE
A CHANCE OF SHOWERS DEVELOPING DURING THE AFTERNOON...BEST CHANCE
AFTER 21Z. WILL CONTINUE A PROB30 OF A RAIN/SNOW MIX FOR DEN AND
INCLUDE FOR BJC AND APA WITH LOWER CEILINGS. ANY SNOW
ACCUMULATIONS WILL BE LIGHT...LESS THAN ONE HALF INCH THROUGH THE
AFTERNOON AND CONFINED TO THE GRASSY AREAS.

.BOU WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON
FOR COZ048-050-051.

WINTER WEATHER ADVISORY FROM 2 PM SATURDAY TO 11 AM MST SUNDAY
FOR COZ033-034.

WINTER WEATHER ADVISORY FROM 11 AM SATURDAY TO 11 AM MST SUNDAY
FOR COZ031.

SHORT TERM...BAKER/D_L
LONG TERM....GIMMESTAD
AVIATION...BAKER/D_L

AREA FORECAST DISCUSSION

NWS LINCOLN IL

1129 PM CST FRI FEB 8 2013

.DISCUSSION...
ISSUED 830 PM CST FRI FEB 8 2013

.AVIATION...
ISSUED 1120 PM CST FRI FEB 8 2013

MAIN FORECAST CHALLENGE THIS PERIOD WILL BE WITH THE PERSISTENT
MVFR CIGS AND WHETHER WE SEE ANY SIGNIFICANT BREAKS DEVELOP IN
THE CLOUDS SATURDAY MORNING. HI-RES FORECAST SOUNDINGS CONTINUE
TO INDICATE SOME EROSION OF THE LOW LEVEL MOISTURE TRAPPED BELOW
A RATHER STRONG SUBSIDENCE INVERSION. SEEING SOME BREAKS ACRS FAR
WEST CENTRAL INDIANA AND EXTREME EASTERN IL LATE THIS EVENING WITH
THE AREA OF SCATTERED TO BKN CIGS TO OUR NORTH EARLIER IN THE
EVENING NOW PUSHING BACK TO THE NNW AS BOUNDARY LAYER WINDS HAVE
SHIFTED INTO THE SOUTH. WILL CONTINUE TO CARRY THE MVFR CIGS OVERNIGHT
WITH BASES AROUND 1500 FEET. WILL CONTINUE FROM THE PREVIOUS FORECAST
IN INTRODUCING SCT-BKN CIGS STARTING AROUND 18Z...WITH SOME HIGH LEVEL
CLOUDS (AROUND 20000-25000 FEET).

THE NEXT WEATHER SYSTEM WILL START TO SPREAD MID LEVEL CLOUDS INTO
OUR AREA SATURDAY EVENING BUT FOR NOW WILL KEEP ANY MENTION OF SHOWERS
OUT OF THE CURRENT TAFS. IT APPEARS THAT IF WE DID SEE ANY RAINFALL
AT PIA OR SPI...IT WOULD BE CLOSER TO 12Z SUNDAY. WINDS WILL CONTINUE
TO SLOWLY VEER INTO A SOUTHEAST DIRECTION THIS MORNING AND CONTINUE
OUT OF THE SOUTHEAST THRU THE REMAINDER OF THE FORECAST PERIOD. SPEEDS
WILL BE LESS THAN 10 KTS TONIGHT...AND INCREASE TO BETWEEN 10 AND
15 KTS DURING THE DAY SATURDAY.

SMITH
&&

.PREV DISCUSSION...
ISSUED 242 PM CST FRI FEB 8 2013

INITIAL FORECAST CHALLENGE WILL BE WITH THE CLOUD COVER
OVERNIGHT...OTHERWISE THE FOCUS WILL BE ON THE RAIN EXPECTED
DURING THE SECOND HALF OF THE WEEKEND.

SHORT TERM...TONIGHT THROUGH MONDAY...

LONG TERM...TUESDAY THROUGH FRIDAY...

GEELHART

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION...CORRECTED

NWS QUAD CITIES IA IL

1139 PM CST FRI FEB 8 2013

.AVIATION...
MVFR TO IFR CIGS EXPECTED TO CONTINUE THROUGH AT LEAST 09/15Z.
CURRENTLY MVFR CIGS TO LOWER TO IFR AFTER 09/10Z...THEN INCREASE
AGAIN. MOISTURE TRAPPED UNDER AN INVERSION WILL REMAIN THERE AS A
SURFACE HIGH MOVES INTO THE GREAT LAKES TONIGHT. SOUTHERLY WINDS
ON THE BACK SIDE OF THE HIGH SHOULD RESULT IN CLEARING DEVELOPING
ACROSS KS/MO THAT BEGINS MOVING NORTH INTO IA/IL AFT 12Z/09.
CONDITIONS SHOULD IMPROVE TO VFR BY 18Z/09. LIGHT AND VARIABLE
WINDS TONIGHT TO SLOWLY INCREASE OUT OF THE SOUTHEAST AT 10-15KT
AFTER 09/15Z. AFTER 10/03Z RAIN SHOWERS TO MOVE INTO THE AREA FROM
THE SOUTHWEST...BUT SHOULD STAY OUT OF THE TERMINALS UNTIL AFTER
06Z TONIGHT. CIGS TO GRADUALLY LOWER DURING THE EVENING BUT TO
REMAIN VFR THROUGH 06Z.

..LE..

.PREV DISCUSSION... /ISSUED 252 PM CST FRI FEB 8 2013/

SHORT TERM...TONIGHT AND SATURDAY...
QUIET AND DRY CONDITIONS WILL BE SEEN ACROSS THE AREA TONIGHT AND
SATURDAY AS HIGH PRESSURE MOVES INTO THE EASTERN GREAT LAKES.

ERVIN

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

AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

1138 PM CST FRI FEB 8 2013

.AVIATION...
MVFR CONDITIONS EXPECTED TO CONTINUE THROUGH AT LEAST 09/15Z.
MOISTURE TRAPPED UNDER AN INVERSION WILL REMAIN THERE AS A SURFACE
HIGH MOVES INTO THE GREAT LAKES TONIGHT. SOUTHERLY WINDS ON THE
BACK SIDE OF THE HIGH SHOULD RESULT IN CLEARING DEVELOPING ACROSS
KS/MO THAT BEGINS MOVING NORTH INTO IA/IL AFT 12Z/09. CONDITIONS
SHOULD IMPROVE TO VFR BY 18Z/09. LIGHT AND VARIABLE WINDS TONIGHT
TO SLOWLY INCREASE OUT OF THE SOUTHEAST AT 10-15KT AFTER 09/15Z.
AFTER 10/03Z RAIN SHOWERS TO MOVE INTO THE AREA FROM THE
SOUTHWEST...BUT SHOULD STAY OUT OF THE TERMINALS UNTIL AFTER 06Z
TONIGHT. CIGS TO GRADUALLY LOWER DURING THE EVENING BUT TO REMAIN
VFR THROUGH 06Z.

..LE..

.PREV DISCUSSION... /ISSUED 252 PM CST FRI FEB 8 2013/

SHORT TERM...TONIGHT AND SATURDAY...
QUIET AND DRY CONDITIONS WILL BE SEEN ACROSS THE AREA TONIGHT AND
SATURDAY AS HIGH PRESSURE MOVES INTO THE EASTERN GREAT LAKES.

ERVIN

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

AREA FORECAST DISCUSSION

NWS TOPEKA KS

338 AM CST SAT FEB 9 2013

.DISCUSSION...

UPPER LOW WAS OVER THE GREAT BASIN FRIDAY EVENING WITH BROAD CIRRUS
PLUME NORTHEAST INTO THE CENTRAL PLAINS. PRECIPITABLE WATER VALUES
WERE WELL BELOW NORMAL FROM KANSAS SOUTHEAST INTO EAST TEXAS...BUT
HIGHER VALUES WERE OVER WEST AND SOUTHWEST TEXAS. PRESSURE GRADIENT
OVER THE CENTRAL AND SOUTHERN PLAINS WAS TIGHTENING WITH STEADY
OVERNIGHT PRESSURE FALLS IN THE WEST.

MAIN FORECAST CHALLENGES ARE PRECIPITATION CHANCES AND WIND SPEEDS
THROUGH SUNDAY AFTERNOON.

WINDS SLOWLY CRANK UP TODAY AS SURFACE HIGH PRESSURE SETTLES IN
BEHIND THE NORTHEAST CONUS BLIZZARD AND THE UPSTREAM LOW CROSSES THE
CROSSES THE ROCKIES. BEST DAYTIME PRESSURE FALLS TO BE TO THE
NORTHWEST AND KEEP A SLIGHTLY BACKED ANGLE TO THE WINDS. WITH CLOUDS
HELPING TO HINDER BEST MIXING...WILL KEEP ADVISORY SPEEDS OUT OF THE
FORECAST...BUT WESTERN LOCATIONS LOOK TO BE CLOSE BY MID AFTERNOON
AND WILL BE THE PRIME AREA TO BE MONITORED.

DEEP MID LEVEL SOUTHWEST FLOW BRINGS AN INITIAL BAND OF HIGH PW
VALUES /AROUND TWO STANDARD DEVIATIONS ABOVE NORMAL FOR TOPEKA/
NORTHEAST INTO EASTERN KANSAS THIS AFTERNOON. FORCING VIA ISENTROPIC
LIFT IS NOT STRONG...BUT MAY BE ENOUGH TO PRODUCE SCATTERED SHOWERS
AND PERHAPS A FEW THUNDERSTORMS. OF NOTE...SOME GUIDANCE HAS THE
AFTERNOON PERIOD AS THE WETTEST OF THE COMING 36 HOURS...AND RECENT
RUNS OF THE RAP AS WELL AS THE 06Z NAM DEVELOP THIS BAND AS WELL.

THIS POSSIBLE INITIAL BAND SHOULD DIMINISH AS IT MOVES NORTHEAST THIS
EVENING...WITH THE NEXT BAND MOST LIKELY TO AFFECT THE AREA IN THE
03Z-09Z RANGE AS THE BEST Q-VECTOR CONVERGENCE MEETS WITH THE MORE
IMPRESSIVE PW TONGUE. THIS WOULD ALSO BE WHEN THE GREATEST ELEVATED
CAPE WOULD MOVE THROUGH...STILL IN THE 200-300 J/KG RANGE...BUT ALSO
WHEN THE CLOUD-BEARING SHEAR IS AT A RELATIVE MINIMUM. GETTING
SEVERE LEVELS OF HAIL OR WIND WOULD SEEM TO BE A STRUGGLE THOUGH
WITH 50KTS OF WINDS LESS THAN 2000 FEET AGL AT LEAST SOME
CONSIDERABLE GUSTS COULD OCCUR. DRY SLOT TO MOVE IN BY DAWN SUNDAY
WITH PRECIPITATION RAPIDLY MOVING NORTHEAST ON VERY STOUT MID LEVEL
WINDS.

SURFACE WINDS SHOULD STAY ON THE BREEZY SIDE THROUGH MUCH OF THE
NIGHT..WITH VEERING AND INCREASING WINDS SUNDAY AS SUBSIDENCE AND
LOW LEVEL LAPSE RATES PICK UP WITH THE SYSTEM HEADING NORTHEAST.
ADVISORY LEVEL SPEEDS APPEAR A PRETTY DECENT BET FOR AT LEAST
NORTHERN AREAS FOR MUCH OF THE DAY...THOUGH THERE ARE SOME
INDICATIONS OF SOME LOW TO MID CLOUD WORKING THEIR WAY BACK
SOUTHEAST INTO THE AREA. PICKING SPECIFIC TIMES AND LOCATIONS FOR AN
ADVISORY AT THIS RANGE IS DIFFICULT AT BEST AND PLENTY OF TIME
EXISTS FOR A HEADLINE TO BE ISSUED. WITH WINDS AND DRY AIR WILL ALSO
BRING ELEVATED FIRE DANGER TO AT LEAST SOUTHERN AREAS WHERE COLD AIR
ADVECTION WILL HOLD OFF THE LONGEST.

THE EARLY TO MID WEEK PERIODS STILL ON THE BENIGN SIDE WITH THE
SECONDARY UPPER TROF SWINGING THROUGH OKLAHOMA. NORTHWEST FLOW TO
BRING AT LEAST ONE WAVE IN FOR THE THURSDAY-FRIDAY PERIODS THOUGH
PRECIP CHANCES LOOK MEAGER IN LIMITED MOISTURE. TEMPS WILL BACK DOWN
FROM SOMEWHAT ABOVE NORMAL LEVELS OF THE NEXT SEVERAL DAYS HOWEVER.

.AVIATION...

MOISTURE RETURN AHEAD OF THE NEXT STORM SYSTEM STILL APPEARS
WILL REMAIN LIMITED WITH MAINLY MID AND HIGH CLOUDS AOA 10KFT UNTIL
AFT 23Z/09 WHEN A VFR STRATOCU DECK AT 4-5KFT DEVELOPS. CONFIDENCE
IN ANY CONVECTION THROUGH 06Z/10 REMAINS TOO LOW TO INSERT INTO
TAF SITES AT THIS POINT. SOUTHEAST WINDS AROUND 10KTS WILL BECOME
MORE SOUTHERLY AND INCREASE TO 15-20KTS AFT 14Z WITH GUSTS NEAR
25 KTS THROUGH 06Z/10.

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

411 AM EST SAT FEB 9 2013

.SYNOPSIS...
COLD NORTHWESTERLY WINDS WILL BRING SCATTERED SNOW SHOWERS AND
FLURRIES TO PORTIONS OF THE AREA THIS MORNING. HIGH PRESSURE WILL
THEN BUILD IN FOR A DRY WEEKEND BEFORE A COLD FRONT CROSSES THE
AREA ON MONDAY.

.NEAR TERM /THROUGH TONIGHT/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH
SHIFTING EAST OF THE AREA AND MERGING WITH A COASTAL LOW OVER NEW
ENGLAND. AT THE SURFACE...A BROAD AREA OF HIGH PRESSURE EXTENDS
ACROSS THE GREAT LAKES AND OHIO VALLEY WITH A 976MB NOR`EASTER OFF
THE NEW ENGLAND COAST. BETWEEN THE TWO FEATURES...THE UPPER OHIO
VALLEY IS IN A NORTH-NORTHWESTERLY FLOW WITH A TIGHTENED PRESSURE
GRADIENT. WITH LAKE ERIE PARTIALLY FROZEN...A LAKE EFFECT FETCH
FROM HURON IS ALLOWING FOR LINGERING FLURRIES FOR THE LOWLANDS AND
UPLOPING SNOW SHOWERS FOR THE RIDGES THIS MORNING.

TODAY AND TONIGHT...MODELS ARE IN AGREEMENT THAT A BROAD 500MB
RIDGE ALONG WITH SURFACE HIGH WILL SLIDE ACROSS THE OHIO VALLEY.
THIS WILL ALLOW FOR DRIER LOW-LEVEL AIR TO ADVECT INTO THE
AREA...BRINGING AN END TO FLURRIES AROUND DAWN AND UPSLOPING BY
AROUND 15Z TODAY. WAA AND SUBSIDENCE ALOFT WILL ALLOW FOR CLOUDS
TO BEGIN TO DECREASE IN COVERAGE THIS AFTERNOON WITH SKIES
CLEARING BY TONIGHT.

FOR TEMPS...HIGHS TODAY ARE FAIRLY CLOSE TO LAMP GUIDANCE
AND RANGE FROM THE MID 20S NORTH OF THE I-80 CORRIDOR AND ACROSS
THE LAUREL HIGHLANDS/ALLEGHENY FRONT TO THE MID 30S ACROSS
PORTIONS OF EASTERN OHIO AND NORTHERN WV. CLEAR SKIES WITH A
HIGH CENTERED EAST OF THE AREA TONIGHT WILL ALLOW FOR RADIATIONAL
COOLING...ESPECIALLY EAST OF PITTSBURGH. THUS...LOWS TONIGHT
RANGE FROM THE SINGLE DIGITS IN FOREST/JEFFERSON/VENANGO COUNTIES
TO NEAR 20 IN PORTIONS OF EASTERN OHIO.

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
GFS/NAM/ECMWF REMAIN IN AGREEMENT THAT A BROAD TROUGH WILL CROSS THE
UPPER OHIO VALLEY ON SUNDAY. WITH THE SURFACE HIGH PUSHING EAST OF
THE AREA...AN ENHANCED SOUTHERLY FLOW BENEATH THE RIDGING WILL
PROMOTE WAA ACROSS THE AREA. THIS WILL ALLOW FOR A WARM AND
DRY DAY AS A SURFACE LOW MOVES INTO THE UPPER MIDWEST AND BEGINS TO
BRING A COLD FRONT ACROSS THE OHIO VALLEY. CLOUDS WILL BE ON THE
INCREASE AHEAD OF THIS SYSTEM ON SUNDAY. STILL...HIGHS ON SUNDAY
WILL 10 TO 15 DEGREES ABOVE NORMAL...RANGING FROM THE MID 40S ACROSS
THE I-80 CORRIDOR AND EASTERN RIDGES TO THE MID 50S IN ERN OH AND
N-CNTRL WV.

SUNDAY NIGHT INTO MONDAY...GFS/ECMWF AGREE THAT THE COLD FRONT WILL
PUSH PRECIP INTO THE AREA AFTER 00Z MON...BRINGING CATEGORICAL POPS
ACROSS THE AREA BY DAWN ON MONDAY. WAA AHEAD OF THE FRONT WILL
BRING 850MB TEMPS UP TO 4-6C ACROSS THE AREA AND ALLOW FOR A
SUFFICIENT MELTING LAYER WITH ALL PRECIP REACHING THE SURFACE IN
THE FORM OF LIQUID EARLY MONDAY. LOWS SUNDAY NIGHT WILL RANGE
FROM NEAR FREEZING ACROSS THE EASTERN RIDGES AND FOREST COUNTY TO
THE LOWER 40S SOUTH AND WEST OF PITTSBURGH. WITH THE WARM SURGE OF
AIR AHEAD OF THE FRONT...HIGHS ON MONDAY ARE AGAIN AROUND 10 TO 15
DEGREES ABOVE NORMAL.

GFS/NAM/SREF ALL STILL INDICATE THAT SFC TEMPS IN
FOREST/JEFFERSON/CLARION AND GARRETT/TUCKER COUNTIES COULD SEE A
BRIEF PERIOD OF FREEZING RAIN WHERE COLD AIR BECOMES TRAPPED AT THE
SURFACE. GENERALLY THINK THIS WOULD BE A VERY BRIEF PERIOD OF
FREEZING RAIN WITH SOUTHERLY WINDS QUICKLY ERODING A SUB-FREEZING
SFC LAYER. THUS...ICE ACCUMULATIONS OF LESS THAN A TENTH OF AN INCH
ARE FORECAST FOR THESE AREAS WHICH ARE ALSO HIGHLIGHTED IN THE HWO.

CAA WILL BE RELATIVELY WEAK IN THE WAKE OF THE FRONT WITH WINDS
SHIFTING TO SWRLY MON AFTERNOON. THUS...PRECIP IS FORECAST TO
REMAIN ALL RAIN ON MONDAY. CRITICAL THICKNESSES DROP SOUTH OF THE
AREA AFTER 00Z TUESDAY AND THUS HAVE A CHANGE OVER TO SNOW SHOWERS
WITH LITTLE ACCUMULATION EXPECTED.

.LONG TERM /TUESDAY THROUGH FRIDAY/...
GFS AND ECMWF BOTH DEPICT A WAVE EJECTING FROM SRN PLNS TUE NGT.
THE FORMER MODEL AMPLIFIES THIS WAVE AS IT CROSSES THE SRN APLCNS
WHILE THE LATTER IS MORE PROGRESSIVE. IF THE GFS IS CORRECT... A
COASTAL LOW WILL DVLP AS THIS WAVE APRCHS THE COAST...AND PCPN
WILL SPREAD NWD INTO AT LEAST SRN PORTIONS OF THE FCST AREA. IF
THE ECMWF IS CORRECT...THE FCST AREA LKLY WILL RMN DRY. ATTM...
HAVE KEPT POPS BLW MEX NUMBERS...BUT SLGTLY HIGHER THAN THEY WERE
IN PREV FCST. ANY PCPN DURG THIS TIME WILL BE SNOW OWING TO
PERSISTENT COLD AIR.

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
LOW LEVEL INSTABILITY AND MOISTURE SHOULD ALLOW FOR SCATTERED SNOW
SHOWERS TO CONTINUE WITH COLD ADVECTION INTO THE MORNING HOURS.
LOW LEVEL SATURATION CAPS OUT AROUND 2 KFT ACROSS THE AREA...SO
MVFR STRATUS SHOULD REMAIN THROUGH THE MORNING HOURS.
HOWEVER...AFTER ROUGHLY 17Z...THE EROSION OF THE INVERSION AS WELL
AS DRIER BOUNDARY LAYER AIR SHOULD ALLOW EVERYONE TO SCATTER OUT
AND EVENTUALLY CLEAR...YIELDING VFR CONDITIONS BY AFTERNOON. FRIES

.OUTLOOK.../SATURDAY THROUGH WEDNESDAY/...
WAA ALOFT AND EXITING EAST COAST SFC LOW WILL SHIFT THE MVFR CLOUD
DECK EASTWARD SATURDAY MORNING. SKIES WILL SLOWLY CLEAR FROM WEST
TO EAST DURING THE AFTERNOON.

VFR CONDITIONS EXPECTED THROUGH SUNDAY.

RESTRICTIONS RETURN SUNDAY NIGHT AND CONTINUE THROUGH MONDAY.

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MDZ001.
OH...NONE.
PA...NONE.
WV...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
WVZ023-041.

SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
SHORT TERM...WOODRUM
AVIATION...FRIES

AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

153 AM EST SAT FEB 9 2013

.SYNOPSIS...
COLD NORTHWESTERLY WINDS WILL BRING SCATTERED SNOW SHOWERS AND
FLURRIES TO PORTIONS OF THE AREA THROUGH DAWN. HIGH PRESSURE WILL
THEN BUILD IN FOR A DRY WEEKEND.

.NEAR TERM /THROUGH TONIGHT/...
AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO INCLUDE
SCATTERED FLURRIES ACROSS MUCH OF THE AREA UNTIL DAWN AND CUT
DOWN ADDITIONAL SNOWFALL TOTALS FOR THE RIDGES TO AN INCH.

THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH
SHIFTING EAST OF THE AREA AND MERGING WITH A COASTAL LOW OVER NEW
ENGLAND. AT THE SURFACE...A BROAD AREA OF HIGH PRESSURE EXTENDS
ACROSS THE GREAT LAKES AND OHIO VALLEY WITH A 976MB NOR`EASTER
OFF THE NEW ENGLAND COAST. BETWEEN THE TWO FEATURES...THE UPPER
OHIO VALLEY IS IN A NORTH-NORTHWESTERLY FLOW WITH A TIGHTENED
PRESSURE GRADIENT. WITH LAKE ERIE PARTIALLY FROZEN OVER...A LAKE
EFFECT FETCH FROM HURON IS ALLOWING FOR LINGERING FLURRIES FOR THE
LOWLANDS AND UPLOPING SNOW SHOWERS FOR THE RIDGES THIS MORNING.

FOR TEMPS...HIGHS TODAY ARE FAIRLY CLOSE TO LAMP GUIDANCE
AND RANGE FROM THE MID 20S NORTH OF THE I-80 CORRIDOR AND ACROSS
THE LAUREL HIGHLANDS/ALLEGHENY FRONT TO THE MID 30S ACROSS
PORTIONS OF EASTERN OHIO AND NORTHERN WV. CLEAR SKIES WITH A
HIGH CENTERED EAST OF THE AREA TONIGHT WILL ALLOW FOR RADIATIONAL
COOLING OVERNIGHT...ESPECIALLY EAST OF PITTSBURGH. THUS...LOWS
TONIGHT RANGE FROM THE SINGLE DIGITS IN FOREST/JEFFERSON/VENANGO
COUNTIES TO NEAR 20 IN PORTIONS OF EASTERN OHIO.

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
UPR RDG DOMINATES THE ERN CONUS ON SUN...WITH SELY RETURN FLOW
DVLPG ON WRN EDGE OF SFC HIPRES. MODEST WARMTH IN THE MID-UPR 40S
XPCD UNDER SCT-BKN CLDS.

GUIDANCE IS QUITE CONSISTENT IN STRENGTHENING AN UPR LOW OVER THE
NRN PLNS ON SUN. STG SLY LOW-LVL JET WILL DVLP IN ADVC OF THIS
WAVE...WHICH WILL ADVCT VERY WARM AIR NWD INTO THE RGN SUN NGT.
WDSPRD RAIN XPCD TO FORM IN THIS WARM AIR ADVCTN PATTERN...SO POPS
WERE INCRD TO CATEGORICAL SUN NGT AREA WIDE IN TANDEM WITH PASSAGE
OF VORT MAX.

TEMPS IN NERN ZONES AND SHELTERED VLYS OF RDG ZONES MAY DROP BLW
FRZG PRIOR TO ONSET OF PCPN. AS A RESULT...FRZG RAIN APPEARS A
PROBABLE SCENARIO IN THESE AREAS...SPCLY LATE SUN NGT. ADZY MAY BE
NEEDED BY FUTURE SHIFTS TO HIGHLIGHT THIS CONCERN.

RAIN WILL CLR OUT MON AFTN AS DRY AIR BCMS ENTRAINED INTO THE
WAVE. ENCROACHING COLD AIR AT H8 AND H9 WILL PERMIT A CHG TO SNOW
MON AFTN-TUE. UNCERTAINTY RMNS IN DVLPMT OF ANY PCPN IN THE WAKE
OF THIS WAVE...SO POPS RMN LOW.

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
LOW LEVEL INSTABILITY AND MOISTURE SHOULD ALLOW FOR SCATTERED SNOW
SHOWERS TO CONTINUE WITH COLD ADVECTION INTO THE MORNING HOURS.
LOW LEVEL SATURATION CAPS OUT AROUND 2 KFT ACROSS THE AREA...SO
MVFR STRATUS SHOULD REMAIN THROUGH THE MORNING HOURS.
HOWEVER...AFTER ROUGHLY 17Z...THE EROSION OF THE INVERSION AS WELL
AS DRIER BOUNDARY LAYER AIR SHOULD ALLOW EVERYONE TO SCATTER OUT
AND EVENTUALLY CLEAR...YIELDING VFR CONDITIONS BY AFTERNOON. FRIES

VFR CONDITIONS EXPECTED THROUGH SUNDAY.

RESTRICTIONS RETURN SUNDAY NIGHT AND CONTINUE THROUGH MONDAY.

SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...FRIES

AREA FORECAST DISCUSSION

NWS GAYLORD MI

319 AM EST SAT FEB 9 2013

.SYNOPSIS...
ISSUED AT 312 AM EST SAT FEB 9 2013

HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER ACROSS THE
REGION THROUGH EARLY SUNDAY. BEYOND THAT...A STORM SYSTEM WILL
ORGANIZE OVER THE PLAINS STATES AND PUSH NORTHEAST TOWARDS THE GREAT
LAKES. THIS WILL BRING A WINTRY MIX OF RAIN...SNOW...SLEET...AND
FREEZING RAIN TO THE REGION BY LATE SUNDAY AND SUNDAY NIGHT.
PRECIPITATION WILL CHANGE BACK TO ALL SNOW ON DURING THE DAY MONDAY
AS COOLER AIR MOVES BACK INTO THE REGION.

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 312 AM EST SAT FEB 9 2013

HIGH IMPACT WEATHER POTENTIAL: NIL.

OVERVIEW: SURFACE RIDGE AXIS DIRECTLY OVER THE REGION EARLY THIS
MORNING WITH IMPRESSIVE NOR`EASTER JUST OFF THE NEW ENGLAND COAST.
NORTHERLY FLOW ON THE WESTERN EDGE OF THIS SYSTEM HAS FALLEN APART
WITH THE ARRIVAL OF THE SURFACE RIDGE...WITH LOCAL LAND BREEZES
TAKING OVER GIVEN A TERRIFIC NIGHT OF RADIATIONAL COOLING UNDER
CLEAR SKIES AND FRESH SNOWPACK. COLDEST TEMPS NEARING -15F AS OF
THIS WRITING.

THROUGH DAYBREAK: LAKE HURON STRATOCU CONTINUES TO PLAGUE THE
IMMEDIATE COASTLINE...WITH PZQ/OSC OCCASIONALLY REPORTING A FEW
FLURRIES. WILL MENTION FLURRIES FOR THE NEXT FEW HOURS...BUT EXPECT
THIS CLOUDINESS TO WANE AS WEAKENING/BACKING BOUNDARY LAYER FLOW
ALONG WITH WARMING TEMPS SLOWLY ERODES THE CLOUDINESS...AS WELL AS
PUSHING IT OFFSHORE. TEMPERATURES WILL CONTINUE TO FALL...EXPECT A
FEW OF THE COLDEST SPOTS TO MAKE A RUN AT -20F BY DAYBREAK...BUT -10-
+5F MOST EVERYWHERE ELSE. THIS HAS CAUSED SOME PATCHY INLAND
GROUND FOG AS OF 08Z...AND WILL CARRY MENTION THROUGH DAYBREAK.

TODAY: SHORTWAVE RIDGING CONTINUES TO BUILD INTO THE REGION AS
NORTHEASTERN TROUGH PULLS INTO THE ATLANTIC. PRIMARY FEATURE OF
NOTE FOR TODAY IS SHORTWAVE CURRENTLY OVER SOUTHERN MANITOBA AND
PUSHING EAST. SOUTH OF THIS FEATURE...SOME MID-UPPER LEVEL /I290K/
ISENTROPIC ASCENT IS HELPING TO FUEL SOME HIGH LEVEL CLOUDINESS AND
WHILE HEIGHTS WILL BUILD OVER OUR REGION TODAY...EXPECT THAT SOME OF
THIS CLOUDINESS WILL FILTER THE SUN FOR MOST AREAS. ALSO OF SOME
CONCERN WILL BE THE LAKE CLOUDINESS THAT CONTINUES EARLY THIS
MORNING OVER LAKE HURON...AND TO A LESSER EXTENT LAKE MICHIGAN.
NEAR TERM RAP GUIDANCE IS FAR TOO PESSIMISTIC WITH CLOUDS...WITH OUR
LOCAL IN HOUSE WRF LOOKING MORE REASONABLE. WITH THE SURFACE RIDGE
MOVING EAST OF THE REGION TODAY...EXPECT SOUTHERLY FLOW TO SLOWLY
BECOME ESTABLISHED AS THE DAY GOES ON...WHICH SHOULD HELP KEEP ANY
LAKE HURON CLOUDINESS AT BAY...BUT WILL ALLOW ANY LAKE MICHIGAN
CLOUDINESS TO BRUSH THE COAST OF NW LOWER...WITH MORE OF AN IMPACT
OVER WESTERN CHIP/MACK. WILL CARRY THE GREATEST CLOUD COVER
HERE...BUT EXPECT THAT EVEN HERE A DECENT AMOUNT OF SUN WILL BE
SEEN.

TEMPS: T9 AROUND -8C SUGGESTS THAT WE COULD MAKE A RUN TOWARDS 30F
TODAY IN SOME SPOTS...PARTICULARLY WITH THE AID OF A GOOD DEAL OF
SUNSHINE. TWEAKED CONSENSUS TEMPERATURES UP JUST A TAD...YIELDING
MID 20S OVER EASTERN UPPER...WITH UPPER 20S OVER NORTHERN LOWER.

TONIGHT: HIGH PRESSURE CONTINUES TO SETTLE SOUTH AND EAST OF THE
REGION WITH SOUTHERLY WINDS BEGINNING TO DEVELOP AHEAD OF OUR NEXT
WEATHER MAKER. PRIMARY CONCERN FOR THE OVERNIGHT IS WILL THE
STRENGTH OF THE LLEVEL FLOW AND THUS IT/S IMPACT ON TEMPERATURES
GIVEN ONLY LIMITED CLOUDINESS /SOME HIGH STUFF...WITH LOWER CLOUDS
OVER WESTERN CHIP-MACK COURTESY OF FLOW OFF LAKE MICHIGAN/. THESE
SCENARIOS TEND TO FAVOR DECOUPLING FOR AT LEAST THE FIRST HALF OF
THE NIGHT...PARTICULARLY SOUTHEAST OF A CAD-APN LINE. THUS...WILL
LOWER CONSENSUS TEMPS SOME IN THIS AREA...WHICH WILL LIKELY ALLOW
SOME SPOTS /E.G. MIO..WEST BRANCH/ TO REACH THE SINGLE DIGITS WITH
TEENS TO THE NORTH AND WEST OF THIS.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 312 AM EST SAT FEB 9 2013

AN UPPER LOW NOW IN THE SOUTHERN GREAT BASIN WILL STEADILY EJECT
ENE-WARD...REACHING THE NORTHERN LAKES ON MONDAY. NORTHERN STREAM
ENERGY WILL DIVE SOUTHWARD BEHIND THE LOW...BUT (THANKFULLY) NOT
PHASE WITH IT...RESULTING IN UPPER TROFFING OVER THE SOUTHERN
ROCKIES INTO MONDAY NIGHT. THE 500MB CIRC WILL BE OPENING UP AS IT
CROSSES THE REGION...STRONGLY SUGGESTING THAT THE BACKSIDE/
WRAPAROUND PORTION OF THE STORM WILL NOT PACK A TON OF PUNCH. THE
FRONT SIDE/WARM ADVECTION PORTION OF THE STORM IS THE BIG ISSUE...
WITH A PLETHORA OF PRECIP TYPES FEASIBLE. PRECIP ISSUES ARE AT THE
FOREFRONT BEGINNING SUNDAY AFTERNOON.

MODELS...PER HPC...WILL STEER THE FORECAST AWAY FROM THE SOMEWHAT
DEEPER/MORE NORTHERLY/SLOWER 00Z NAM SOLUTION. THE GFS/ECMWF OFFER
REASONABLY CLOSE AND BLENDABLE SOLUTIONS. THE CONSENSUS FAVORS A
SOMEWHAT FASTER PUSH OF PRECIP INTO THE AREA THAN EARLIER FORECAST.

SUNDAY...500MB LOW MOVES FROM S CENTRAL NEB TO S CENTRAL MN...WHILE
THE DOWNSTREAM RIDGING MOVES FROM THE CENTRAL TO EASTERN GREAT
LAKES. SURFACE LOW IS NEARLY STACKED (JUST SOUTH OF) THE 500MB
CIRC...AND WILL FILL VERY SLIGHTLY (990 TO 992MB). A CONSIDERABLE
SURGE IN WARM/MOIST ADVECTION WILL BE SEEN IN MI...ESPECIALLY IN THE
AFTERNOON. WEAK ISENTROPIC ASCENT (295K SURFACE) IS ALREADY PRESENT
AT 12Z...BUT RAMPS UP SUBSTANTIALLY AS THE DAY PROCEEDS. THE AIRMASS
BELOW 650MB IS INITIALLY DRY (DEW PT DEPRESSIONS TO 30C)...BUT WE
WILL ERODE THAT IN THE MORNING...AND ANNIHILATE IT IN THE AFTERNOON
(ESPECIALLY AFTER 21Z). LATE-DAY POPS WILL RANGE FROM LIKELY/
CATEGORICAL IN THE WEST HALF OF THE FORECAST AREA...TO CHANCE IN THE
ST MARYS VALLEY AND THE NE LOWER MI COAST.

P-TYPE...GFS BUFR SOUNDINGS SUPPORT MUCH OF OUR EARLIER THINKING.
THE NW LOWER MI COAST...AIDED BY A DOWNSLOPING SE WIND AND STRONGER
WARM ADVECTION...SHOULD BE JUST ABOUT ALL RAIN. BY THE TIME YOU
GET UP TOWARD THE STRAITS (PLN)...SOME SLEET COULD ENTER THE PICTURE
(WITH THE WARM NOSE ONLY TO 3C AND SOME EVAP COOLING STILL
POSSIBLE)...BUT SURFACE TEMPS STILL LOOK TO BE ABOVE FREEZING. FOR
EASTERN UPPER...SNOW WILL BE THE MAIN PRIMARY P-TYPE THRU 00Z (UP TO
HALF AN INCH IN WESTERN MACKINAC CO...LESS ELSEWHERE). THE HIGH
TERRAIN OF NORTH CENTRAL LOWER IS THE MAIN POTENTIAL HEADACHE (GIVEN
QPF WILL BE SMALL IN EASTERN SECTIONS). HERE...GFS BUFR SOUNDINGS
ARE COMFORTABLY IN THE PL/FZRA CATEGORY (THOUGH GFS GUIDANCE TEMPS
ARE WARMER THAN THE RAW SOUNDINGS SHOW...LOWER 30S VS UPPER 20S).
WILL GO WITH PRIMARILY RA/FZRA/PL...AND LESS THAN A TENTH OF AN INCH
OF ICE.

MAX TEMPS 30 TO 40F. INCREASING SE/ESE WIND WILL BE STRONGEST IN
EASTERN UPPER.

SUN NIGHT...LARGELY STACKED LOW HOLDS STEADY-STATE AS IT MOVES
TOWARD S CENTRAL UPPER MI. HEAVIEST PRECIP OF THE EVENT WILL BE
SUNDAY EVENING...BEFORE THE WARM CONVEYOR BELT MOVES EAST AND THE
MID-LEVEL DRY SLOT ARRIVES. 1000-850MB COLD ADVECTION ALSO BEGINS
OVERNIGHT. EXCELLENT POTENTIAL FOR A THIRD TO TWO-THIRDS OF AN INCH
OF LIQUID EQUIV PRECIP ACROSS THE FORECAST AREA BETWEEN LATE SUNDAY
AFTERNOON INTO EVENING. HEAVIEST WILL BE NORTH OF THE ONCOMING WARM
FRONT...IN FAR NORTHERN LOWER AND EASTERN UPPER.

P-TYPE...IN EASTERN UPPER...MAINLY SNOW IN THE EVENING...TURNING TO
FLURRIES/FZDZ OVERNIGHT AS MID-LEVELS DRY. SLEET MIXING IN NEAR
LAKES MI/HURON. SNOW-LIQUID RATIOS POOR...GIVEN DEEP LAYER WARMER
THAN -10C (UP TO 600MB)...AND MAX ASCENT NEAR 750MB/-5C. THAT WON/T
PRECLUDE AN EVENT TOTAL OF 2-5 INCHES THERE.

NORTHERN LOWER...STILL ALL LIQUID NEAR LAKE MI...AND QUICKLY
BECOMING ALL LIQUID (OR FREEZING) ELSEWHERE. AND WITHOUT A STRONG
BLOCKING HIGH TO OUR NE TO FEED IN COOL/DRY AIR...EVEN TEMPS OVER
THE HIGH TERRAIN SHOULD COME UP DURING THE EVENING. BUFR
SOUNDINGS...NUMERIC GUIDANCE...AND BASIC PATTERN RECOGNITION ALL
SUPPORT THIS IDEA. WILL TAKE THINGS TO RAIN/DZ ACROSS ALL OF
NORTHERN LOWER DURING THE EVENING...THOUGH STILL POTENTIAL FOR UP TO
A TENTH OF AN INCH OF ICE OVER THE HIGHER TERRAIN. ALL TOLD...THIS
LOOKS LIKE A POTENTIAL ADVISORY EVENT FOR EASTERN UPPER (SNOW) AND
THE HIGH TERRAIN OF NORTHERN LOWER (ICE). THESE HEADLINES DO NOT
NEED TO BE ISSUED AT THIS TIME.

BY DAYBREAK...DEEPER MOISTURE WILL BE WRAPPING BACK INTO PARTS OF NW
LOWER...THOUGH THE SURFACE-BASED ABOVE-FREEZING LAYER UP THRU 900MB
SHOULD STILL KEEP THINGS LIQUID.

MONDAY...SURFACE LOW CROSSES EASTERN UPPER AT MIDDAY...AND WILL BE
JUST NORTH OF GEORGIAN BAY BY EVENING. MAY YET BE A SMALL REMNANT
CLOSED CIRC AT 500MB STACKED WITH IT BY THE END OF THE DAY. DEEPER
MOISTURE FLOODS BACK INTO NORTHERN MI...BUT COLD AIR DOES NOT...WITH
850MB TEMPS HOVERING IN THE -3 TO -5C RANGE. WE/LL BE PLENTY CLOUDY
AND DREARY...WITH MIXED LIGHT RAIN/SNOW/DRIZZLE. A SLOPPY INCH OR SO
OF ACCUMS IS POSSIBLE. TEMPS WILL HOVER IN THE 30S ALL DAY.

REST OF THE FORECAST...TIME PERMITS ONLY A SOMEWHAT CURSORY LOOK AT
THESE PERIODS. THE ENERGY LEFT BACK IN THE SOUTHERN ROCKIES WILL
MOVE EASTWARD...TRIGGERING MID-WEEK CYCLOGENESIS THAT IMPACTS THE
GULF COAST AND MID-ATLANTIC STATES. THIS SYSTEM DOES NOT LOOK TO
HAVE AN IMPACT HERE...WITH QUIET AND RELATIVELY MILD WX IN THE
NORTHERN LAKES. WE AWAIT THE NORTHERN STREAM TO BECOME MORE
ENERGETIC...WHICH WILL HAPPEN LATE IN THE WORK WEEK. POPS WILL
INCREASE BY FRIDAY. THERE IS POTENTIAL FOR ANOTHER BIG EAST COAST
STORM...AND AN INJECTION OF COLDER AIR INTO OUR NECK OF THE
WOODS...FOR NEXT WEEKEND.

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1236 AM EST SAT FEB 9 2013

SUMMARY: RIDGE OF HIGH PRESSURE IN CONTROL THROUGH THE PERIOD WITH
EARLY MORNING FOG/STRATOCUMULUS CONCERNS GIVING WAY UNRESTRICTED
CONDITIONS.

RESTRICTIONS: WHILE WE HAVE SEEN MBL DEAL WITH SOME FOG LATE IN THE
EVENING...LLEVEL DRYING LOOKS TO BE ADEQUATE TO KEEP ANY SUBSTANTIAL
FOG FROM FORMING. SO...WHILE A FEW PATCHES OF GROUND FOG ARE
POSSIBLE...LIKELIHOOD IS TOO LOW TO INCLUDE IN THIS TAF PACKAGE.
OTHER CONCERN IS REGARDING LAKE CLOUDS...THAT HAVE INFLUENCED TVC
AND APN. EXPECT AN IMPROVING TREND HERE AS WELL...WITH STRENGTHENING
LAND BREEZE COMPONENT. THIS SHOULD YIELD PRIMARILY VFR CONDITIONS
THROUGH THE TAF PERIOD /OUTSIDE OF 1-3 MORE HOURS OF MVFR CIGS IN
THE VICINITY OF APN/...WITH JUST SOME HIGH CLOUDINESS FOR THE
BALANCE OF THE DAY AND INTO SATURDAY EVENING.

WINDS: CALM WINDS FOR THE OVERNIGHT WILL BECOME SOUTHERLY 5-10 KTS
FOR THE DAY ON SATURDAY BEFORE DIMINISHING TO LESS THAN 5KTS
SATURDAY EVENING.

LLWS: SOME LOW END POTENTIAL FOR LLWS AT THE VERY END OF THIS TAF
PERIOD WITH 2KFT WINDS STRENGTHENING TOWARDS 25-30KTS FROM THE
SOUTH. GIVEN THAT ITS/ MARGINAL AND ABOUT 21 HOURS OUT...WILL
REFRAIN FROM INCLUDING IN THIS TAF PACKAGE.

.MARINE...
ISSUED AT 312 AM EST SAT FEB 9 2013

SUMMARY: GENERALLY QUIET THROUGH SUNDAY AS SURFACE HIGH PRESSURE
OVER THE REGION THIS MORNING SHIFTS EAST WITH SOUTH-SOUTHEASTERLY
WINDS DEVELOPING TODAY AND CONTINUING THROUGH SUNDAY AS A LOW
PRESSURE SYSTEM APPROACHES THE GREAT LAKES FROM THE WEST. THIS
SYSTEM WILL PASS ACROSS UPPER MICHIGAN MONDAY WITH BRISK SOUTHWEST
WINDS ACROSS THE NEARSHORE WATERS GIVING WAY TO LIGHTER
NORTHWESTERLY WINDS BY TUESDAY.

HEADLINE POTENTIAL: FRESHENING SOUTHERLY WINDS WILL BRING
NEARSHORE ZONES ALONG LAKE MICHIGAN NEAR SMALL CRAFT CRITERIA BY
LATE TODAY/TONIGHT. SMALL CRAFTS BECOME LIKELY LATE SUNDAY THROUGH
MONDAY AS THE AFOREMENTIONED LOW PRESSURE SYSTEM TRACKS ACROSS UPPER
MICHIGAN.

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

SYNOPSIS...JA
SHORT TERM...JA
LONG TERM...JZ
AVIATION...JA
MARINE...JA

AREA FORECAST DISCUSSION...UPDATED

NWS NORTH PLATTE NE

1124 PM CST FRI FEB 8 2013

.UPDATE...

.AVIATION...
AN INVERTED TROF/STATIONARY FRONT WILL SET UP ACROSS WRN NEB
TONIGHT AND REMAIN STATIONARY SATURDAY. WEST OF THE FRONT...MVFR/IFR
CIGS WILL DEVELOP. THE FRONT WILL CREEP EAST LATE SATURDAY
AFTN/EVENING AND BECOME THE FOCUS FOR WIDESPREAD IFR/LIFR SATURDAY
EVENING. EAST OF THE FRONT...SCATTERED TSTMS ARE EXPECTED SATURDAY EVENING.

.PREV DISCUSSION... /ISSUED 512 PM CST FRI FEB 8 2013/

UPDATE...

AVIATION...
THE RUC IS DEVELOPING STRATUS WITH IFR/MVFR CIGS FROM THE NORTH
AND EAST OVERNIGHT. BEST GUESS ON KVTN IS 15Z. SO MVFR IS EXPECTED
TO DEVELOP ALONG HIGHWAY 20 AND ALONG AND EAST OF HIGHWAY 183 LATE
TONIGHT OR EARLY SATURDAY AM.

A SECOND AREA OF MVFR CIGS SHOULD MOVE UP FROM THE SOUTH SATURDAY
AFTN AND ENCROACH ON KLBF AROUND 21Z.

PREV DISCUSSION... /ISSUED 356 PM CST FRI FEB 8 2013/

.LBF WATCHES/WARNINGS/ADVISORIES...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
FOR NEZ028-029-038-058-059.

BLIZZARD WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING FOR
NEZ004>010-022>027-035>037-056-057-094.

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

AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

108 AM EST SAT FEB 9 2013

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1015 PM UPDATE...
UL LOW STILL SPINNING ACRS WRN NY AND EAST COAST UL WV NRNG CAPE
COD ATTM. SNOW IS DCRSG WEST OF THE I-81 CORRIDOR THO
BANDS CONTINUE TO DVLP AT RANDOM AND PRODUCE 1 TO 1.5 INCHES/HR
THUS NO CHGS WL BE MADE TO WSW HEADLINES AT THIS TIME EXCEPT FOR A
REFRESH OF WRDG. LATEST RAP UPGLIDE IN THE 285K LAYER INDICATES
SNOW WL CONTINUE ALONG THE I-81 CORRIDOR FOR THE NEXT HR BFR BCMG
SIGNIFICANTLY LIGHTER.

ONLY MINOR TWEAKS TO STORM TOTALS, CLOSER TO 7 INCHES AREA-WIDE
WITH ERN ZONES EXPECTING 6-9 INCHES. OTHER THAN THESE CHGS HV JUST
TWEAKED HRLY T/TD VALUES.

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
230 PM UPDATE... MAJOR WINTER STORM WILL CONTINUE TO PULL AWAY FROM OUR
AREA ON SAT. HOWEVER...IN THE AM HRS...SOME MULTI-BAND/FINGER LKS
LES BANDS ARE LIKELY...AS LONG AS THE DEEPER SYNOPTIC MOISTURE
LINGERS...WITH LOW-LVL CAA...AND A 320-340 FLOW. WE`VE ADDED THE
POTENTIAL FOR LOCALIZED 1-2" SNOWS THIS PD...SPCLY DOWNWIND FROM
CAYUGA LAKE. DURG THE AFTN (STARTING 15-18Z)...SIG DRYING IS
PROGGED...WITH SKIES EXPECTED TO CLEAR OUT AREA-WIDE. WINDS WILL
BE GUSTY ON SAT...OWING TO A TIGHT PRES GRADIENT BETWEEN THE
INTENSE STORM OFF THE NEW ENG COAST...AND HIGH PRESSURE TO OUR W.

SUN LOOKS QUIET...WITH SUNSHINE FADING BEHIND INCREASING CLDS IN THE AFTN.

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
MAIN SYNOPTIC SNOW WINDING DOWN ATTM BUT STILL SOME IFR/MVFR CIGS
AND VSBYS IN LGT SNOW AND BLSN. XPCT LTL CHG OVRNGT OTR THAN A
SLOW IMPRVMT. GUSTY WINDS WILL CONT TO DVLP ALL STATIONS AS THE
LOW DEEPENS OFF THE NEW ENG CST. ON SAT...NW FLOW WILL DVLP SOME
LE SNOW THRU ABT MIDDAY WITH MVFR CIGS AND VSBY PSBL. LTR IN THE
DAY AND THRU THE END OF THE PD...VERY DRY AIR AND A LWRG INV SHD
BRING VFR SKIES AND VSBYS.

.OUTLOOK...

SUN...VFR.

SUN NGT/MON...MVFR/IFR POSSIBLE IN A WINTRY MIX /INCLUDING
FREEZING RAIN/...CHANGING TO ALL RAIN ON MON.

MON NGT TO TUE NGT...SCT MVFR CNTRL NY IN -SHSN...VFR ELSEWHERE.

WED...IMPROVE TO VFR.

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR
PAZ038>040-043-044-047-048-072.
NY...WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR NYZ009-
015>018-022>025-036-037-044>046-055>057-062.

$$
SYNOPSIS...MSE
NEAR TERM...MSE/PVN
SHORT TERM...MLJ
LONG TERM...TAC
AVIATION...DGM/DJP

AREA FORECAST DISCUSSION

NWS NORMAN OK

1011 PM CST FRI FEB 8 2013

.AVIATION...
SOUTH WIND SATURDAY MORNING WILL BRING LOW CLOUDS AND A MOIST
ATMOSPHERE SOUTH TO NORTH ACROSS OKLAHOMA BY AFTERNOON. LIGHT RAIN
IS EXPECTED BEFORE THUNDERSTORMS LATER IN THE EVENING ASSOCIATED
WITH A DRYLINE PASSAGE. THUNDERSTORMS COULD BE ONGOING A FEW HOURS
BEFORE 110600 IN CENTRAL OKLAHOMA.

.PREV DISCUSSION... /ISSUED 945 PM CST FRI FEB 8 2013/

UPDATE...
VERY FEW CHANGES WERE MADE TO THE ONGOING FORECAST. WITH
INCREASING LOW/MID LEVEL MOISTURE OVERNIGHT...EXPECT CLOUD COVER
TO CONTINUE TO EXPAND AND LOWER. RECENT HRRR RUNS DEPICT AREA OF
VERY LIGHT SHOWERS/DRIZZLE MAY DEVELOP AROUND 09Z AND MOVE INTO TX
AND SW OK ZONES BY AROUND 10Z TO 12Z. THEREFORE..INTRODUCED
MENTION OF DRIZZLE IN WX GRIDS. OTHERWISE...ONLY MADE MINOR TWEAKS
TO HOURLY TEMPS/DEWPOINTS/WINDS TO REFLECT RECENT TRENDS. EXPECT
MOISTURE TO CONTINUE TO RETURN NWD...MAKING FOR A VERY CLOUDY DAY
TOMORROW. INTERMITTENT SHOWERS WILL BE LIKELY BEGINNING AROUND
MIDDAY TOMORROW...LASTING INTO THE EVENING BEFORE A LINE OF STORMS
MOVES ACROSS THE AREA.

PREV DISCUSSION... /ISSUED 646 PM CST FRI FEB 8 2013/

PREV DISCUSSION... /ISSUED 221 PM CST FRI FEB 8 2013/

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&

09/84/84

AREA FORECAST DISCUSSION

NWS SIOUX FALLS SD

1115 PM CST FRI FEB 8 2013

.AVIATION.../FOR THE 06Z TAF ISSUANCE/
MAIN FORECAST CHALLENGE THROUGH THIS TAF PERIOD WILL BE POTENTIAL
REDEVELOPMENT OF IFR-LIFR STRATUS TONIGHT...WITH PRECIPITATION
ISSUES DEVELOPING LATE IN THE PERIOD. SEEING STRATUS REDEVELOP
ACROSS THE EAST...AND WILL EXPECT THIS TO SPREAD BACK INTO AT LEAST
THE I-29 CORRIDOR AND POSSIBLY REACH THE JAMES VALLEY THROUGH 12Z.
LESS CONFIDENCE IN STRATUS REACHING KHON SO HAVE KEPT THEM LARGELY
WITH SCATTERED CLOUDS BELOW 1KFT. POSSIBLE THEY COULD GO BKN-OVC
BEFORE DAYBREAK THOUGH...AND WILL MONITOR CLOSELY. THINK WINDS WILL
STAY UP ENOUGH THAT VISIBILITY RESTRICTIONS WILL BE LIMITED...THOUGH
PATCHY MVFR VISIBILITY IS POSSIBLE. ANY STRATUS/FOG WILL LINGER
THROUGH THE LATE MORNING/MIDDAY HOURS SATURDAY...BEFORE STRONGER
MIXING AHEAD OF SIGNIFICANT WINTER SYSTEM AIDS IN CLEARING TO VFR
CONDITIONS FOR SATURDAY AFTERNOON. WINTER STORM WILL SPREAD PRECIP
INTO THE AREA AFTER 00Z...WITH MOST AREAS BEGINNING AS RAIN WITH VFR
VISIBILITIES AND MVFR/IFR CEILINGS. KHON COULD SEE CHANGEOVER TO -SN
PRIOR TO THE END OF THE PERIOD AND INTRODUCED SOME MVFR VISIBILITY
IN -SN THERE AFTER 04Z. MID LEVEL INSTABILITY COULD ALSO LEAD TO
ISOLATED TSRA AROUND KSUX/KFSD SATURDAY EVENING. HOWEVER CONFIDENCE
IN DEVELOPMENT/COVERAGE IN THUNDER THREAT IS LOW...SO DID NOT
INCLUDE MENTION AT THIS TIME.

.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING FOR
MNZ071-072-097.

BLIZZARD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING FOR
MNZ080-081-098.

NE...NONE.
SD...BLIZZARD WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING FOR
SDZ040-054>056-059>062-064-065-068.

BLIZZARD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING FOR
SDZ066-067-069.

BLIZZARD WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY MORNING
FOR SDZ038-039-050-052-053-057-058-063.

AREA FORECAST DISCUSSION

NWS DENVER/BOULDER CO

432 AM MST SAT FEB 9 2013

.SHORT TERM...THE POTENT UPPER LEVEL LOW IS STILL EXPECTED TO MOVE
OVER COLORADO TODAY AND TONIGHT...EVENTUALLY BRINGING
PRECIPITATION ACROSS THE ENTIRE FORECAST AREA. INITIALLY...EASTERN
COLORADO IS UNDER A SIZABLE DRY SLOT OUT AHEAD OF THE UPPER LEVEL
SYSTEM. THIS HAS KEPT SKIES ACROSS THE PLAINS CLEAR OVERNIGHT
WHILE MOUNTAIN AREAS HAVE SEEN INCREASING CLOUDS AND A FEW SNOW
SHOWERS. SATELLITE IMAGERY IS BEGINNING TO SHOW DECENT CLOUD TOP
COOLING OVER EASTERN UTAH AND FAR WESTERN COLORADO AS THE STRONG
DYNAMICS NEAR THE LOW CENTER LIFT THE AIRMASS. THE LATEST MODEL
RUNS OF THE RAP ARE NOW SHOWING THE CENTER OF THE UPPER LOW
PASSING OVER COLORADO SPRINGS ON THE WAY TO NORTHWESTERN KANSAS.
THE ATTENDENT SURFACE LOW WILL ALSO REMAIN OVER THE PALMER
DIVIDE...HELPING THE FRONT RANGE CORRIDOR TO COME UNDER INCREASING
NORTH TO NORTHEAST WINDS LATE IN THE AFTERNOON AND EARLY EVENING.
OVERALL...THE SYSTEM DOES NOT SEEM TO CONTAIN ABUNDANT
MOISTURE...SO PRECIPITATION AMOUNTS SHOULD REMAIN ON THE LIGHT
SIDE. HOWEVER...MODEL SOUNDINGS AND CROSS SECTIONS SHOW THAT AS
THE UPPER LOW IS MOVING OVERHEAD THROUGH THE EVENING HOURS...THE
MID LEVELS WILL BE FAIRLY UNSTABLE WHICH WILL ALLOW FOR STRONG
RISING MOTIONS IN RESPONSE TO THE DYNAMIC LIFT FROM THE UPPER LOW.
SKIES ACROSS THE PLAINS SHOULD GRADUALLY CLOUD OVER DURING THE
AFTERNOON WITH RAIN SHOWERS DEVELOPING LATE. RAIN WILL THEN
QUICKLY CHANGE OVER TO SNOW EARLY IN THE EVENING. GIVEN THE
CONVECTIVE NATURE OF THE SHOWERS...LIGHT TO MODERATE SNOW WILL BE
POSSIBLE ALONG THE FRONT RANGE URBAN CORRIDOR FOR A FEW HOURS IN
THE EVENING. SNOW ACCUMULATIONS UP TO 4 OR 5 INCHES CAN NOT BE
RULED OUT...BUT THE MORE LIKELY TOTALS WILL BE 1 TO 3 INCHES.
LATER IN THE EVENING...WINDS WILL SWITCH TO NORTHWESTERLY WHICH
WILL BRING DRYING ALONG THE URBAN CORRIDOR. MOUNTAIN AREAS SHOULD
RECEIVE LIGHT TO MODERATE SNOWFALL THROUGH TODAY AS THE LOW MOVES
OVERHEAD AND SNOW SHOWERS OVERNIGHT AS COLD ADVECTION CONTINUES IN
THE WAKE OF THE UPPER LOW.

THE OTHER FORECAST CONCERN IS INCREASING NORTHERLY WINDS ACROSS
THE PLAINS TONIGHT AS THE SURFACE LOW DEEPENS ALONG THE EASTERN
BORDER. THE COMBINATION OF WIND AND SNOW OVER THE NORTHEAST CORNER
WILL NECESSITATE UPGRADING THE BLIZZARD WATCH TO A BLIZZARD
WARNING.

.LONG TERM...THE UPPER LEVEL STORM SYSTEM WILL MOVE QUICKLY
NORTHEAST OF THE AREA ON SUN HOWEVER SOME SNOW WILL LINGER OVER
THE FAR NERN PLAINS THRU MID MORNING BEFORE GRADUALLY ENDING BY
MIDDAY. WINDS WILL REMAIN VERY GUSTY THRU SUN AFTN SO EXPECT A LOT
OF BLOWING SNOW AND POOR VISBILITIES FM AKRON TO STERLING EASTWARD
SO WILL KEEP BLIZZARD WARNING THRU THE AFTN HOURS. ELSEWHERE SOME
OROGRAPHIC SNOW WILL CONTINUE IN THE MTNS DUE TO ABUNDANT MOISTURE
AND DECENT LAPSE RATES. ALONG THE FRONT RANGE DOWNSLOPE NWLY LOW
LVL FLOW WILL LIMIT PCPN CHANCES HOWEVER WINDS WILL BE GUSTY FM
THE WY BORDER SOUTHWARD ALONG I-25 TOWARD DENVER. AS FOR HIGHS
READINGS SHOULD STAY IN THE 30S ACROSS NERN CO.

FOR SUN NIGHT INTO MON A SECONDARY UPPER LEVEL SYSTEM WILL MOVE
SOUTHWARD OVER THE AREA. IN ADDITION A SECOND SURGE OF COLDER AIR
MAY ACCOMPANY THIS TROUGH WITH WK UPSLOPE FLOW SUN NIGHT INTO MON IN
AND NR THE FOOTHILLS AND OVER THE PALMER DIVIDE. THUS COULD SEE A
CHC OF LIGHT SNOW OVERNIGHT INTO MONDAY MOST OF THE ACTIVITY WEST
OF I-25. OVER THE NERN PLAINS IT WILL BE DRY WITH SOME GUSTY WINDS
OVER THE FAR NERN CORNER BUT NOT NEARLY AS STG AS SUN. IN THE MTNS
ABUNDANT MOISTURE WILL CONTINUE SUN NIGHT AND MON WITH DECENT
LAPSE RATES HOWEVER THE FLOW AT 700 MB IS WEAK SWLY. WILL LIKELY
SEE MORE LIGHT SNOW WITH SOME MINOR ACCUMULATIONS. HIGHS ON MON
WILL BE COLD WITH READINGS IN THE MID 20S TO AROUND 30 ACROSS NERN
CO.

BY TUE THE UPPER LEVEL TROUGH WILL MOVE SOUTH OF THE AREA WITH
DRYING AIR MOVING IN. THUS SHOULD END PCPN CHANCES. 850-700 MB
TEMPS BEGIN TO RISE SO SHOULD SEE HIGHS IN THE UPPER 30S TO LOWER
40S ALTHOUGH SNOW COVER OVER THE FAR NERN CORNER MAY KEEP READINGS
IN THE LOWER TO MID 30S. FOR WED THE FLOW ALOFT WILL BECOME NWLY
WITH SOME MOISTURE MOVING BACK INTO THE MTNS BY AFTN SO WILL
MENTION A SLIGHT CHC OF SNOW. OVER NERN CO IT WILL BE DRY WITH
TEMPS MODERATING BACK INTO THE 40S.

FOR WED NIGHT AND THU THERE ARE DIFFERENCES BETWEEN THE ECMWF AND
THE GFS WITH REGARDS TO A DISTURBANCE EMBEDDED IN THE NWLY FLOW.
THE ECMWF HAS THIS FEATURE MOVING ACROSS NRN CO WED NIGHT INTO
EARLY THU MORNING WITH A GOOD CHC OF SNOW IN THE MTNS. OVER THE
PLAINS IT HAS A BORA TYPE FNT MOVING ACROSS WITH NO PCPN.
MEANWHILE THE GFS IS HAS THE FEATURE MOVING ACROSS THU AFTN INTO
THU EVENING AS ANOTHER SURGE OF COLDER AIR MOVES INTO NERN CO. AS
A RESULT THIS PRODUCES A CHC OF SNOW OVER NERN CO THU AFTN INTO
THU EVENING. THIS FAR OUT NOT SURE WHAT TO BELIEVE SO WILL JUST
LEAVE IN LOW POPS FOR NERN CO ON THU. IN THE MTNS WILL MENTION A
CHC OF SNOW WED NIGHT INTO THU.

BY FRI NNW FLOW ALOFT IS SHOWN OVER THE AREA. THE ECMWF SHOWS
ANOTHER POSSIBLE WAVE EMBEDDED IN THE FLOW MOVING ACROSS DURING
THE DAY WHILE THE GFS SHOWS NOTHING. MEANWHILE THE ECMWF SHOWS
ANOTHER CDFNT AFFECTING NERN CO WHILE THE GFS DOES NOT SHOW THIS
FNT. AS A RESULT THE ECMWF GENERATES SOME UPSLOPE FLOW AND A CHC
OF LIGHT SNOW ALONG THE FNT RANGE ON FRI. FOR NOW WILL JUST
MENTION LOW POPS IN THE MTNS AND ALONG THE FRONT RANGE.

.AVIATION...CEILINGS WILL GRADUALLY LOWER THROUGH THE AFTERNOON
HOURS WITH A FAIR AMOUNT OF VIRGA PRECEDING SHOWERS THAT DEVELOP
AFTER 22Z. PRECIPITATION SHOULD BEGIN AS RAIN BUT THEN QUICKLY
CHANGE TO SNOW AFTER ABOUT 00Z. CEILINGS COULD DROP BELOW 6000
FEET AGL BY 22Z AND MAY THEN DROP TO MVFR BY 01Z. SNOW SHOWERS
THROUGH THE EVENING WILL DROP CEILINGS AND VSBYS INTO THE IFR
CATEGORY. IMPROVING CONDITIONS ARE EXPECTED AFTER 06Z. SNOW
ACCUMULATIONS OF 1 TO 3 INCHES CAN BE EXPECTED...BUT IF MULTIPLE
SNOW SHOWERS MOVE OVER THE AIRPORT...AMOUNTS UP TO 5 INCHES WILL
BE POSSIBLE.

.BOU WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FROM 5 PM THIS AFTERNOON TO 5 PM MST SUNDAY FOR
COZ048>051.

WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 11 AM MST
SUNDAY FOR COZ033-034.

WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 11 AM MST
SUNDAY FOR COZ031.

SHORT TERM...DANKERS
LONG TERM....RPK
AVIATION...DANKERS

AREA FORECAST DISCUSSION

NWS TOPEKA KS

531 AM CST SAT FEB 9 2013

...UPDATE TO AVIATION...

.DISCUSSION...

MAIN FORECAST CHALLENGES ARE PRECIPITATION CHANCES AND WIND SPEEDS
THROUGH SUNDAY AFTERNOON.

.AVIATION...

VFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE PERIOD. A
TIGHTENING PRESSURE GRADIENT WILL MAKE FOR WINDS FROM THE
SOUTHEAST NEAR 17 KTS WITH GUSTS UP TO 25 KTS AFTER 14Z TODAY.
MOISTURE WILL BEGIN TO INCREASE LATER TODAY AND EXPECT SOME
SHOWERS TO DEVELOP LATER THIS EVENING AND CONTINUE ON AND OFF
OVERNIGHT. SOME ISOLATED TSRA IS POSSIBLE AS WELL. AREAS OF MVFR
CIGS ARE EXPECTED TO DEVELOP AFTER 09Z SUNDAY.

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

635 AM EST SAT FEB 9 2013

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
LOW LEVEL INSTABILITY AND MOISTURE SHOULD ALLOW FOR SCATTERED SNOW
SHOWERS TO CONTINUE WITH COLD ADVECTION INTO THE MORNING HOURS.
LOW LEVEL SATURATION CAPS OUT AROUND 2-4 KFT ACROSS THE AREA...SO
MVFR STRATUS SHOULD REMAIN THROUGH THE MORNING HOURS.
HOWEVER...AFTER ROUGHLY 17Z...THE EROSION OF THE INVERSION AS WELL
AS DRIER BOUNDARY LAYER AIR SHOULD ALLOW EVERYONE TO SCATTER OUT
AND EVENTUALLY CLEAR...YIELDING VFR CONDITIONS BY AFTERNOON. FRIES

VFR CONDITIONS EXPECTED THROUGH SUNDAY.

RESTRICTIONS RETURN SUNDAY NIGHT AND CONTINUE THROUGH MONDAY.

AREA FORECAST DISCUSSION

NWS GAYLORD MI

1045 AM EST SAT FEB 9 2013

.SYNOPSIS...
ISSUED AT 312 AM EST SAT FEB 9 2013

.UPDATE...
ISSUED AT 1044 AM EST SAT FEB 9 2013

CLEAR AND COLD FOR A GOOD PART OF THE CWA THIS MORNING. BUT...WITH
SHALLOW LAKE INSTABILITY LINGERING...DO HAVE LAKE CLOUDS/SNOW
SHOWERS TO ADDRESS. SATELLITE IMAGERY REVEALING AMPLE LAKE CLOUDS
OVER LAKES MICHIGAN AND HURON THIS MORNING STREAMING INTO PARTS OF
EASTERN UPPER MICHIGAN WITH THE SOUTHERLY LOW LEVEL FLOW NOW
DEVELOPING. BUT WITH A STRONG INVERSION UP THROUGH 5K FEET THIS
MORNING AND 850 MB TEMP OF -6C...LAKE CLOUDS ARE VERY SHALLOW.
NONETHELESS...MANISTIQUE (KISQ) REPORTED M1/4SM SN ABOUT AN HOUR
AGO...LIKELY VERY FINE SNOW EFFECTIVELY REDUCING VSBYS. NO
EVIDENCE ON RADAR...PUNCTUATING JUST HOW SHALLOW THE CONVECTION
IS.

REST OF TODAY...SOUTHERLY FLOW WILL INCREASE THROUGH THE BALANCE
OF THE DAY ADVECTING MUCH WARMER LOW LEVEL AIR INTO THE GREAT
LAKES (0C 850MB LINE EDGING INTO LOWER MICHIGAN BY 00Z). SHOULDN/T
SEE MUCH IN THE WAY OF INLAND CU DEVELOPMENT TODAY (TO DRY AND INVERSION
TO STRONG). BUT...REMAINING SHALLOW LAKE CLOUDS WILL CONTINUE TO
GET SHOVED INTO UPPER MICHIGAN THROUGH MUCH OF THE DAY...PARTICULARLY
OFF LAKE MICHIGAN WITH A SLIGHT WESTERLY COMPONENT TO THE WIND.
QUESTION IS WHETHER THERE WILL BE ENOUGH OF A WESTERLY COMPONENT
TO PUSH CLOUDS INTO THE MBL/FKS/TVC AREA THIS AFTERNOON. PROBABLY
EVENTUALLY...BUT LATER IN THE AFTERNOON AFTER WE LOSE THE LAND
BREEZE COMPONENT AND GET A STRONGER WESTERLY COMPONENT TO THE MEAN
LOW LEVEL WIND. WILL TREND THE SKY FORECASTS IN THAT DIRECTION.

IN ADDITION...HAVE ADDED SCT POPS FOR LIGHT SNOW SHOWERS TO A
SLIVER OF WESTERN MACKINAC COUNTY THIS MORNING TO ACCOUNT FOR
NUISANCE LAKE EFFECT SNOW UP THAT WAY. THINK THAT AS WE CONTINUE
TO WARM ALOFT/STRENGTHEN THE INVERSION THAT EVENTUALLY THE SNOW
WILL SHUT OFF...HOPEFULLY BY AFTERNOON.

UPDATE ISSUED AT 642 AM EST SAT FEB 9 2013

STILL QUITE CHILLY BUT (MAINLY) QUIET OUT THERE. FLURRIES PERSIST
NEAR ROGERS CITY...AND SOME FOG IS SEEN IN SOUTHERN SECTIONS OF
THE FORECAST AREA. NEITHER OF THESE WILL LAST MUCH PAST DAYBREAK.

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 312 AM EST SAT FEB 9 2013

HIGH IMPACT WEATHER POTENTIAL: NIL.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 312 AM EST SAT FEB 9 2013

MAX TEMPS 30 TO 40F. INCREASING SE/ESE WIND WILL BE STRONGEST IN
EASTERN UPPER.

BY DAYBREAK...DEEPER MOISTURE WILL BE WRAPPING BACK INTO PARTS OF NW
LOWER...THOUGH THE SURFACE-BASED ABOVE-FREEZING LAYER UP THRU 900MB
SHOULD STILL KEEP THINGS LIQUID.

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 642 AM EST SAT FEB 9 2013

VFR. LLWS TVC/MBL TONIGHT.

HIGH PRESSURE DIRECTLY OVERHEAD EARLY THIS MORNING. SKIES MOSTLY
CLEAR BUT VERY COLD WITH CALM WINDS. LAKE EFFECT CLOUDS CONTINUE
TO BE IN THE NEIGHBORHOOD OF APN...BUT AS SOUTH WINDS DEVELOP AS
THE HIGH MOVES EAST...THESE WILL MOVE AWAY FROM THE FIELD. LIGHT
SOUTH WINDS DEEVLOPING TODAY AND INTO TONIGHT. STRONGER WINDS JUST
OFF THE DECK TONIGHT NEAR LAKE MI...AS WARMER AIR STARTS TO
INVADE. THIS WILL RESULT IN LLWS AT TVC/MBL FOR PART OF TONIGHT.

.MARINE...
ISSUED AT 312 AM EST SAT FEB 9 2013

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

UPDATE...BA
SYNOPSIS...JA
SHORT TERM...JA
LONG TERM...JZ
AVIATION...JZ
MARINE...JA

AREA FORECAST DISCUSSION

NWS GAYLORD MI

642 AM EST SAT FEB 9 2013

.SYNOPSIS...
ISSUED AT 312 AM EST SAT FEB 9 2013

.UPDATE...
ISSUED AT 642 AM EST SAT FEB 9 2013

STILL QUITE CHILLY BUT (MAINLY) QUIET OUT THERE. FLURRIES PERSIST
NEAR ROGERS CITY...AND SOME FOG IS SEEN IN SOUTHERN SECTIONS OF
THE FORECAST AREA. NEITHER OF THESE WILL LAST MUCH PAST DAYBREAK.

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 312 AM EST SAT FEB 9 2013

HIGH IMPACT WEATHER POTENTIAL: NIL.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 312 AM EST SAT FEB 9 2013

MAX TEMPS 30 TO 40F. INCREASING SE/ESE WIND WILL BE STRONGEST IN
EASTERN UPPER.

BY DAYBREAK...DEEPER MOISTURE WILL BE WRAPPING BACK INTO PARTS OF NW
LOWER...THOUGH THE SURFACE-BASED ABOVE-FREEZING LAYER UP THRU 900MB
SHOULD STILL KEEP THINGS LIQUID.

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 642 AM EST SAT FEB 9 2013

VFR. LLWS TVC/MBL TONIGHT.

.MARINE...
ISSUED AT 312 AM EST SAT FEB 9 2013

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

UPDATE...JZ
SYNOPSIS...JA
SHORT TERM...JA
LONG TERM...JZ
AVIATION...JZ
MARINE...JA

AREA FORECAST DISCUSSION

NWS RALEIGH NC

922 AM EST SAT FEB 9 2013

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE CAROLINAS TODAY AND SETTLE
OVERHEAD TONIGHT THROUGH EARLY SUNDAY. THE HIGH WILL DRIFT OFFSHORE
LATE SUNDAY. SOUTHERLY FLOW ON THE BACK SIDE OF THE HIGH WILL ADVECT
MOIST AIR INTO THE CAROLINAS SUNDAY NIGHT.

.NEAR TERM /THROUGH SUNDAY/...
AS OF 920 AM SATURDAY...

THROUGH TODAY: LOTS OF SUN TODAY WITH AREA AND UPSTREAM RADIOSONDE
DATA SHOWING VERY DRY AIR THROUGH THE COLUMN AND FAST CONFLUENT NW
FLOW ALOFT WITH STRONG DEEP SUBSIDENCE TAKING PLACE. SOUNDING DATA
ALSO SHOWS 20-30 KTS OF WIND THIS MORNING THROUGH THE SHALLOW MIXED
LAYER JUST OFF THE SURFACE... ALTHOUGH THIS WILL BE DIMINISHING AS
THE DAY GOES ON AS THE 925 MB ANTICYCLONE AND SURFACE RIDGE CENTER
OVER THE LOWER GREAT LAKES BUILDS SOUTHEAST WITH A NEW CENTER
FORMING OVER THE WRN CAROLINAS LATER TODAY. WILL RETAIN BREEZY
CONDITIONS AND OCCASIONAL GUSTS MAINLY IN THE EAST UNTIL EARLY
AFTERNOON. THE DRY-ADIABATIC THERMAL PROFILE FROM THE RAP MODEL
OUTPUT SUPPORTS HIGHS OF 50 TO 59 (NE TO SW). -GIH

TONIGHT:
SURFACE HIGH PRESSURE WILL SETTLE OVER THE REGION TONIGHT... WITH
RIDING ALOFT OVERHEAD. HOWEVER... WE WILL BEGIN TO SEE SOME HIGH
CLOUD FILTER INTO THE REGION FROM THE NEXT S/W TROUGH AND ASSOCIATED
COLD FRONT APPROACHING THE AREA FROM THE CENTRAL U.S. THIS MAY
IMPACT OVERNIGHT LOW TEMPS A BIT... MOST ACROSS THE WEST. THUS...
WILL SHOW LOW TEMPS RANGING FROM THE MID TO LOWER 20S EAST AND USUAL
RURAL COLD OUTLYING AREAS (EXCEPT FOR THE FAR WESTERN PORTIONS OF
THE CWA) TO THE UPPER 20 TO NEAR 30 IN THE FAR WEST AND URBAN AREAS.

SUNDAY:
MAINLY MID AND HIGH LEVEL CLOUD COVER WILL BE ON THE INCREASE ACROSS
THE AREA ON SUNDAY... AS BOTH THE SURFACE HIGH AND RIDGING ALOFT
SLIDE TO THE EAST OF THE AREA. EXPECT ANY RAIN TO REMAIN TO THE WEST
OF THE AREA THROUGH EARLY SUNDAY EVENING AS BOTH THE NAM AND GFS
BUFR SOUNDINGS SHOW A GOOD DEAL OF DRY AIR BELOW 600 MB ACROSS
CENTRAL NC. GIVEN THE INCREASING CLOUD COVER AND ONLY ON AVERAGE OF
5 TO 10 METER INCREASE IN LOW LEVEL THICKNESS VALUES WILL KEEP TEMPS
ON THE COOL SIDE OF GUIDANCE AND GO WITH HIGHS RANGING FROM 53 NORTH
TO 59 SOUTH... NEAR NORMAL FOR THIS TIME OF YEAR.

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 300 AM SATURDAY...

SUNDAY NIGHT AND MONDAY...LOW LEVEL SLY FLOW ON THE BACK SIDE OF THE
SURFACE RIDGE WILL INCREASE OVER CENTRAL NC SUNDAY NIGHT INTO MONDAY
MORNING. THE ADVECTION OF THE MOIST WARM AIR OVER THE RESIDUAL COLL
DRY AIR MASS DEPOSITED BY THE RETREATING SURFACE RIDGE WILL SET UP
AN OVERRUNNING RAIN EVENT LATE SUNDAY NIGHT THROUGH MONDAY MORNING.
EXPECT RAIN TO COMMENCE IN OUR WESTERN COUNTIES PRIOR TO
MIDNIGHT...AND OVERSPREAD THE REMAINDER OF CENTRAL NC LATE SUNDAY
NIGHT THROUGH EARLY MONDAY. MIN TEMPS NEAR 40 NE TO THE MID-UPPER
40S SOUTH-SOUTHWEST.

BULK OF LIFT/MOISTURE WILL MOVE E-SE OF CENTRAL NC MONDAY
AFTERNOON-EVENING. THUS...EXPECT RAIN TO DIMINISH NW-SE. A SURFACE
COLD FRONT ASSOCIATED WITH A DEEP LOW PRESSURE SYSTEM OVER THE GREAT
LAKES WILL REMAIN WEST OF OUR AREA MONDAY. THE DIFFERENCE IN
PRESSURE BETWEEN THE HIGH OFFSHORE AND THE LOW WILL CAUSE BREEZY SW
WINDS MONDAY AFTERNOON. MOST LOCATIONS WILL SEE GUSTS BETWEEN 20-25
MPH. THIS FLOW WILL LIKELY SCOUR OUT THE RAIN-COOLED PIEDMONT AIR
MASS. THIS SUGGEST A BUMP UP IN AFTERNOON TEMPS FROM THE PREVIOUS
FORECAST. EXPECT MAX TEMPS MONDAY NEAR 60 NW TO CLOSE TO 70 SE.
THESE NUMBERS FAVOR THE COOL SIDE OF MOS GUIDANCE.

MONDAY NIGHT AND TUESDAY...THE DEEP LOW PRESSURE SYSTEM OVER
THE GREAT LAKES WILL OPEN UP AND MOVE ENE ACROSS ONTARIO/QUEBEC.
THIS WILL CAUSE THE FLOW OVER CENTRAL NC TO BECOME MORE
WLY...PUSHING THE SURFACE COLD FRONT THROUGH OUR REGION MONDAY
NIGHT. FRONTAL PASSAGE WILL LIKELY BE UNEVENTFUL...ASIDE FROM A FEW
STRAY SHOWERS OVER THE FAR SOUTH-SE EARLY IN THE EVENING. DRIER AIR
BEHIND THE FRONT WILL LIMIT PRECIP CHANCES THROUGH TUESDAY
AFTERNOON. THE APPROACH OF A MID-UPPER LEVEL LOW PRESSURE SYSTEM
FROM THE WEST WILL BRING MOISTURE BACK INTO OUR SOUTHERN COUNTIES
TUESDAY AFTERNOON...CAUSING A THREAT OF RAIN FOR AREAS SOUTH OF
HIGHWAY 64 LATE IN THE DAY. MIN TEMPS MONDAY NIGHT MID 40S TO NEAR
50. HIGH TEMPS TUESDAY 59-64.

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 327 AM SATURDAY...

TUESDAY NIGHT INTO WEDNESDAY...THE APPROACH OF A MID-UPPER LEVEL LOW
PRESSURE SYSTEM FROM THE WEST WILL INDUCE A SURFACE LOW TO DEVELOP
OVER THE NORTHERN GULF COAST TUESDAY AND LIFT NEWD TUESDAY NIGHT
ALONG A SURFACE FRONT THAT WILL LIE ACROSS GA-SOUTHERN SC. MEANWHILE
A WEAK AREA OF HIGH PRESSURE ORIENTATED WEST-TO-EAST ACROSS THE
NORTHERN MID ATLANTIC WILL MAINTAIN A FLOW OF RELATIVELY COOL DRY
SURFACE AIR ACROSS VA AND POSSIBLY NORTHERN NC. THE RAIN SHIELD
ASSOCIATED WITH GULF LOW IS PROJECTED TO REACH INTO OUR SOUTHERN
COUNTIES LATE TUESDAY AFTERNOON...AND CREEP NWD TUESDAY NIGHT INTO
WEDNESDAY. PRESENCE OF COOLER/DRIER SURFACE AIR ACROSS OUR NORTHERN
COUNTIES WILL INITIALLY LIMIT PRECIP FROM REACHING THE SURFACE BUT
EXPECT AIR MASS TO SATURATE ENOUGH BY LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING FOR RAIN TO REACH THE GROUND.

THE CORE OF THE MID-UPPER LEVEL LOW WILL CROSS CENTRAL NC WED
AFTERNOON-EVENING. GFS BUFKIT SOUNDINGS SUGGEST THAT THE RAIN MAY
MIX WITH A LITTLE WET SNOW OVER THE NW PIEDMONT BEFORE ENDING. WHILE
THIS SCENARIO CANNOT BE RULED OUT...OTHER PARAMETERS...SUCH AS
PARTIAL THICKNESS SCHEME...SUGGEST THAT THE LOWER LEVELS WILL REMAIN
WARM ENOUGH TO PREVENT SNOW FROM REACHING THE SURFACE.
THUS...WILL KEEP PRECIP ALL LIQUID FOR NOW.

THE PASSAGE OF THE MID-UPPER LEVEL LOW PRESSURE SYSTEM WED EVENING
WILL CAUSE PRECIP CHANCES TO DIMINISH/DWINDLE WEST-TO-EAST ACROSS
CENTRAL NC. W-NW FLOW WILL ADVECT DRIER AND COOLER AIR...LEADING TO
DECREASING CLOUDINESS WED NIGHT.

CENTRAL NC WILL BE BETWEEN TWO MAIN BRANCHES OF THE UPPER LEVEL JET
THU AND FRI WITH THE NORTHERN BRANCH MORE ENERGETIC. THIS TYPE PF
PATTERN USUALLY FAVORS DRY WEATHER WITH SPORADIC PERIODS OF MID-HIGH
LEVEL CLOUDINESS AND TEMPS NEAR TO SLIGHTLY ABOVE NORMAL. EXPECT DRY
WEATHER THU-FRI. MAX TEMPS IN THE 50S THU...MODERATING TO 55-60 FRI.

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 640 AM SATURDAY...

24-HR TAF PERIOD:
VFR CONDITIONS WILL CONTINUE FOR THE 24 HOUR TAF PERIOD.

HIGH PRESSURE WILL BUILD INTO THE AREA TODAY... THEN SETTLE OVER THE
REGION TONIGHT. THIS WILL YIELD GENERALLY CLEAR SKIES AND VFR
CONDITIONS. WEST TO WEST-NORTHWESTERLY WINDS EARLY THIS MORNING WILL
BECOME NORTHWESTERLY AFTER SUNRISE AND THIS AFTERNOON... WITH WINDS
SPEEDS GENERALLY IN THE 8 TO 15 MPH RANGE. HOWEVER... WE COULD SEE A
BRIEF PERIOD OF WIND GUSTS AROUND 20 MPH AFTER SUNRISE THIS MORNING
UNTIL THE EARLY AFTERNOON ACROSS THE EASTERN TAF SITES (MAINLY
KRWI). WINDS WILL QUICKLY BECOME LIGHT/VARIABLE THIS EVENING WITH
THE LOSS OF DIURNAL HEATING AND HIGH PRESSURE BUILDING OVERHEAD.

LOOKING AHEAD:
VFR CONDITIONS WILL PERSIST THROUGH SUNDAY AS HIGH PRESSURE SLOWLY
SHIFTS TO THE EAST OF THE AREA. THE NEXT CHANCE FOR SUB-VFR
CONDITIONS (IFR/LIFR CEILINGS/RAIN) WILL BE SUNDAY NIGHT AND MONDAY
IN ASSOC/W AN IN-SITU COLD AIR DAMMING WEDGE EXPECTED TO DEVELOP
OVER THE CAROLINAS. ADVERSE AVIATION CONDITIONS MAY LINGER OR
RE-DEVELOP ACROSS PORTIONS OF THE AREA INTO MIDWEEK... ESPECIALLY
ACROSS THE EASTERN TAF SITES.

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

$$
SYNOPSIS...WSS
NEAR TERM...HARTFIELD/BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BSD/VINCENT

AREA FORECAST DISCUSSION...UPDATED

NWS FORT WORTH TX

605 AM CST SAT FEB 9 2013

.AVIATION...
/12Z TAFS/

CONCERNS...MVFR CEILINGS THIS MORNING...STORMS TONIGHT.

MOISTURE RETURN CONTINUES. FWD RAOB AND VWP DATA SHOW LLJ OF
30-35KTS...BUT MVFR CEILINGS ARE ONLY SPOTTY AT TAF ISSUANCE
TIME. EXPECT THE LAYER INVOF 2KFT AGL WILL BECOME MORE SOLID AS
THE MORNING PROGRESSES...GRADUALLY LIFTING INTO THE AFTERNOON.
EXPECT ANY SCATTERING WILL BE TEMPORARY AS SURFACE HEATING SIMPLY
REINFORCES THE STRATOCU LAYER.

SURFACE WINDS WILL INCREASE IN ADVANCE OF AN APPROACHING STORM
SYSTEM. SATURATED ISENTROPIC UPGLIDE WILL RESULT IN SOME -RA/-SHRA
AS EARLY AS THIS EVENING. ALTHOUGH THE MAIN MID-LEVEL ENERGY WILL
BE WELL NORTH...AN ASSOCIATED SURFACE FRONT WILL BE DRAGGED WEST
TO EAST THROUGH THE REGION LATE TONIGHT THROUGH SUNDAY MORNING.
THE FRONT WILL BE PRECEDED BY A SQUALL LINE WITH POTENTIALLY
SEVERE STORMS. THE 12Z TAFS DELAY THE EARLIEST ARRIVAL OF THE
SIGNIFICANT CONVECTION UNTIL 09Z (3 AM CST). THE ORIENTATION OF
THE FLOW ALOFT IS SUCH THAT THE LINE OF STORMS MAY NOT REACH THE
TAF SITES UNTIL AS LATE AS 12Z (6 AM CST).

.PREV DISCUSSION... /ISSUED 429 AM CST SAT FEB 9 2013/
UPPER LEVEL TROUGH OVER THE GREAT BASIN WILL MARCH EAST TODAY AND
EJECT NORTHEASTWARD OUT INTO THE PLAINS TONIGHT AND SUNDAY. AHEAD
OF THE APPROACHING TROUGH...STRONG SOUTHERLY FLOW OVER NORTH TEXAS
WILL RESULT IN INCREASING MOISTURE AND CLOUDS TODAY. DUE TO
PRONOUNCED SOUTHWEST FLOW BETWEEN 700-800MB OFF OF THE HIGHER
TERRAIN OF MEXICO...A STRONG CAPPING INVERSION WILL BE IN PLACE
OVER NORTH TEXAS THROUGH THIS EVENING. MODEL SOUNDINGS DO INDICATE
THE PRESENCE OF WEAK CONVECTIVE INSTABILITY AND SATURATION ABOVE
THE INVERSION NEAR AND ABOVE 12000FT. MOST OF THIS PRECIPITATION
WILL EVAPORATE BEFORE HITTING THE GROUND...SO RADARS WILL BE A BIT
DECEIVING TODAY. THIS ELEVATED CONVECTION PROBABLY WILL NOT BE
INTENSE ENOUGH FOR ANY THUNDER...AND LITTLE TO NO MEASURABLE RAIN
IS EXPECTED. WILL CARRY JUST A SLIGHT CHANCE OF SHOWERS TODAY.

AS THE SOUTHERN EDGE OF THE UPPER TROUGH AXIS SWEEPS ACROSS TEXAS
TONIGHT...STRONG FORCING WILL RAPIDLY LIFT AND ERODE THE CAP.
MEANWHILE A NORTH-SOUTH ORIENTED PACIFIC FRONT WILL MOVE INTO
THE AREA FROM THE WEST AFTER MIDNIGHT. SINCE THE AIRMASS WILL BE
UNCAPPED AND CONTAIN LOW LEVEL INSTABILITY ../WITH PARCELS IN THE
LOWEST KM CONTAINING CAPE ON THE ORDER OF 500 J/KG ACROSS THE
NORTH AND 1500 J/KG ACROSS THE SOUTH/.. A LINE OF CONVECTION
SHOULD DEVELOP ALONG THE FRONT. DEEP LAYER SHEAR WILL BE MORE THAN
ADEQUATE FOR SEVERE WEATHER. GUIDANCE CONTINUES TO INDICATE A
RAPID VEERING/WEAKENING OF THE LOW LEVEL SHEAR PROFILE JUST AHEAD
OF THE FRONT. THUS THE TORNADO THREAT APPEARS TO BE LIMITED...AND
THE PRIMARY SEVERE THREAT WILL BE DAMAGING WINDS AND HAIL.

THERE IS A BIT OF UNCERTAINTY REGARDING THE TIMING OF THE LINE OF
STORMS. I AM CONCERNED THAT WITH THE UPPER LEVEL SYSTEM CURVING
OFF TO THE NORTHEAST AND LITTLE TO NO PRESSURE RISES/COLD AIR
BEHIND THE FRONT...THE FRONT/SQUALL LINE MAY SLOW DOWN AS IT MOVES
ACROSS THE CWA. SOME OF THE HIGH-RES GUIDANCE IS INDICATING A
SLOWER PROGRESSION...AND THE RAP AT 18HRS HAS THE FRONT A BIT
FARTHER TO THE WEST THAN THE MEDIUM RANGE MODELS. WILL SLOW THE
TIMING DOWN A BIT FROM PREVIOUS FORECASTS...WHICH WILL RESULT IN
INCREASING THE POPS AFTER 12Z SUNDAY MAINLY OVER THE EAST. RIGHT
NOW EXPECT THE LINE TO REACH THE WESTERN CWA AROUND 1-2AM...AFFECT
THE I-35 CORRIDOR AROUND 3-7AM...AND NOT EXIT THE SOUTHEASTERN
ZONES UNTIL LATE MORNING TUESDAY. GENERALLY SUNNY SKIES AND VERY
DRY AIR WILL ALLOW TEMPS TO REBOUND SUNDAY AFTERNOON INTO THE LOW
70S ACROSS THE CENTRAL/WESTERN ZONES...WITH SLIGHTLY COOLER HIGHS
IN THE EAST WHERE THERE WILL BE MORE CLOUDS.

MID LEVEL CLOUDS WILL LINGER ACROSS THE SOUTHEAST HALF OF THE CWA
INTO MONDAY. LOWS SUNDAY NIGHT WILL BE COOLEST IN THE CLEAR NW
ZONES WHERE THEY WILL DROP TO NEAR FREEZING...BUT THEY WILL ONLY
BE IN THE UPPER 40S OVER THE SOUTHEAST. ON MONDAY A SHORTWAVE
WILL MOVE THROUGH IN SOUTHWEST FLOW ALOFT ACROSS CENTRAL TX...AND
WILL SHOW A SLIGHT CHANCE OF SHOWERS IN THE SOUTHEAST.

A SECOND UPPER LEVEL TROUGH WILL BE APPROACHING TEXAS ON MONDAY
NIGHT WHICH WILL RESULT IN WARM ADVECTION AND ISENTROPIC LIFT
OVER NORTH TEXAS. BEST CHANCES OF RAIN OCCUR TUESDAY WHEN A COLD
FRONT MOVES THROUGH THE REGION AND STRENGTHENS THE ISENTROPIC
LIFT. ACROSS THE NORTHERN ZONES...SURFACE TEMPS MAY GET COLD
ENOUGH NEAR THE CORE OF THE UPPER LOW TO SUPPORT A RAIN/SNOW MIX.
HOWEVER MODEL GUIDANCE HAS TRENDED THE TRACK OF THE UPPER SYSTEM
FARTHER TO THE NORTH. SUCH A TRACK WOULD KEEP THE SNOW POTENTIAL
IN OKLAHOMA. COOLER AND DRY WEATHER WILL PREVAIL WEDNESDAY WITH
TEMPS NEAR NORMAL. THURSDAY LOOKS WARMER WITH SOUTHERLY WINDS
AHEAD OF ANOTHER COLD FRONT THURSDAY NIGHT. TEMPS WILL FALL BELOW
NORMAL BEHIND THIS FRONT FOR FRIDAY AND SATURDAY. GFS/ECMWF BOTH
HAD PRECIP BEHIND THIS FRONT YESTERDAY BUT THE GFS IS TRENDING
DRIER...AND THE 0Z ECMWF IS COMPLETELY DRY. WILL KEEP POPS OUT OF
THE FORECAST ON FRIDAY AT THIS TIME.

TR.92

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 63 55 72 41 65 / 20 90 30 5 10
WACO, TX 64 57 74 43 68 / 20 80 50 10 20
PARIS, TX 59 54 68 38 62 / 20 80 60 5 10
DENTON, TX 61 53 71 35 64 / 20 90 30 5 10
MCKINNEY, TX 61 55 70 34 64 / 20 90 40 5 10
DALLAS, TX 63 56 72 43 65 / 20 90 40 5 10
TERRELL, TX 63 57 71 41 65 / 20 80 60 5 10
CORSICANA, TX 64 59 71 45 65 / 20 70 70 10 20
TEMPLE, TX 65 58 74 44 69 / 20 70 60 10 20
MINERAL WELLS, TX 63 50 72 35 67 / 20 90 20 5 10

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

25/92

AREA FORECAST DISCUSSION

NWS FORT WORTH TX

429 AM CST SAT FEB 9 2013

.DISCUSSION...
UPPER LEVEL TROUGH OVER THE GREAT BASIN WILL MARCH EAST TODAY AND
EJECT NORTHEASTWARD OUT INTO THE PLAINS TONIGHT AND SUNDAY. AHEAD
OF THE APPROACHING TROUGH...STRONG SOUTHERLY FLOW OVER NORTH TEXAS
WILL RESULT IN INCREASING MOISTURE AND CLOUDS TODAY. DUE TO
PRONOUNCED SOUTHWEST FLOW BETWEEN 700-800MB OFF OF THE HIGHER
TERRAIN OF MEXICO...A STRONG CAPPING INVERSION WILL BE IN PLACE
OVER NORTH TEXAS THROUGH THIS EVENING. MODEL SOUNDINGS DO INDICATE
THE PRESENCE OF WEAK CONVECTIVE INSTABILITY AND SATURATION ABOVE
THE INVERSION NEAR AND ABOVE 12000FT. MOST OF THIS PRECIPITATION
WILL EVAPORATE BEFORE HITTING THE GROUND...SO RADARS WILL BE A BIT
DECEIVING TODAY. THIS ELEVATED CONVECTION PROBABLY WILL NOT BE
INTENSE ENOUGH FOR ANY THUNDER...AND LITTLE TO NO MEASURABLE RAIN
IS EXPECTED. WILL CARRY JUST A SLIGHT CHANCE OF SHOWERS TODAY.

TR.92

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

AREA FORECAST DISCUSSION

NWS DENVER/BOULDER CO

955 AM MST SAT FEB 9 2013

.UPDATE...

.SHORT TERM...PRETTY GOOD MODEL CONSENSUS NOW ON THE STORM
TRACK...SIMILAR TO WHAT THE ECMWF HAS BEEN SHOWING FOR DAYS.
DIFFERENCES NOW APPEAR TO BE MAINLY DUE TO RESOLUTION AND PRECIP
PROCESSES IN THE MODELS. IN GENERAL THE TREND HAS BEEN TO SHIFT
THE AREA OF HEAVY SNOW INTO NORTHEASTERN COLORADO AND THE SOUTHERN
NEBRASKA PANHANDLE. PATTERNS ARE SIMILAR IN ALL THE MODELS WITH A
BAND FROM A LITTLE WAYS EAST OR NORTHEAST OF DENVER UP TOWARD
SIDNEY OR OGALLALA NEBRASKA. THE NAM HAS THE STRONGEST DEVELOPMENT
PER ITS RESOLUTION AND PRODUCES A 10-20 INCH SNOW BAND THAT
STARTS NEAR DIA AND RUNS NORTHEAST ACROSS LOGAN COUNTY. NOT READY
TO BITE ON THAT INTENSITY THOUGH THE INSTABILITY IS THERE AND I
WOULD NOT RULE IT OUT...I WILL ALLOW FOR THE POSSIBILITY OF AT
LEAST HALF THAT WHICH COULD BRING BLIZZARD CONDITIONS FURTHER
SOUTH AND WEST. DOWNSLOPE OFF THE CHEYENNE RIDGE WILL SERIOUSLY
LIMIT THE SNOWFALL ACROSS WELD AND LARIMER COUNTIES AND SOUTHWARD
INTO THE DENVER AREA...THOUGH IT WILL BE INTERESTING TO SEE HOW
MUCH THE AREA EAST OF DENVER GETS WHERE THE WIND IS RUNNING UPHILL
AGAIN. I DID RAISE ACCUMULATIONS IN THESE MARGINAL AREAS FROM
NORTHEAST WELD COUNTY DOWN TO LIMON...AND WITH SLIGHTLY STRONGER
WINDS TOO THIS WILL REQUIRE EXPANDING THE BLIZZARD WARNING INTO NE
WELD AND MORGAN COUNTIES.

FURTHER WEST NOT MUCH TO CHANGE...AREAS NEAR THE FOOTHILLS COULD
GET SKUNKED THOUGH THE CONVECTIVE BAND MOVING ACROSS THE MOUNTAINS
NOW LOOKS TO HAVE DECENT INTENSITY...SO THE IDEA OF AN INCH OR TWO
IN A FEW HOURS CLOSE TO THE FRONT RANGE STILL LOOKS LIKE THE MOST
LIKELY SCENARIO. THIS COULD COME FAST ENOUGH TO CAUSE SOME
PROBLEMS AROUND DENVER...BUT THEN IT SHOULD END BY MIDNIGHT AND
THE MAIN SHOW WILL CONTINUE TO THE EAST.

.AVIATION...NO BIG CHANGES AT THIS POINT. IT IS LOOKING LIKE THERE
MAY BE A PERIOD OF PREVAILING IFR CONDITIONS DURING THE EARLY
EVENING...WILL HAVE TO LOOK AT THAT FURTHER. MORE UNCERTAINTY
ABOUT KDEN SNOW AMOUNTS AS WELL...LOOKING MORE LIKE 2-4 INCHES
THAN 1-2 INCHES WHICH COULD CAUSE A BIT MORE BLOWING/DRIFTING.
LESS SNOW AT KBJC AND PROBABLY KAPA AS WELL.

.PREV DISCUSSION... /ISSUED 432 AM MST SAT FEB 9 2013/

SHORT TERM...THE POTENT UPPER LEVEL LOW IS STILL EXPECTED TO MOVE
OVER COLORADO TODAY AND TONIGHT...EVENTUALLY BRINGING
PRECIPITATION ACROSS THE ENTIRE FORECAST AREA. INITIALLY...EASTERN
COLORADO IS UNDER A SIZABLE DRY SLOT OUT AHEAD OF THE UPPER LEVEL
SYSTEM. THIS HAS KEPT SKIES ACROSS THE PLAINS CLEAR OVERNIGHT
WHILE MOUNTAIN AREAS HAVE SEEN INCREASING CLOUDS AND A FEW SNOW
SHOWERS. SATELLITE IMAGERY IS BEGINNING TO SHOW DECENT CLOUD TOP
COOLING OVER EASTERN UTAH AND FAR WESTERN COLORADO AS THE STRONG
DYNAMICS NEAR THE LOW CENTER LIFT THE AIRMASS. THE LATEST MODEL
RUNS OF THE RAP ARE NOW SHOWING THE CENTER OF THE UPPER LOW
PASSING OVER COLORADO SPRINGS ON THE WAY TO NORTHWESTERN KANSAS.
THE ATTENDENT SURFACE LOW WILL ALSO REMAIN OVER THE PALMER
DIVIDE...HELPING THE FRONT RANGE CORRIDOR TO COME UNDER INCREASING
NORTH TO NORTHEAST WINDS LATE IN THE AFTERNOON AND EARLY EVENING.
OVERALL...THE SYSTEM DOES NOT SEEM TO CONTAIN ABUNDANT
MOISTURE...SO PRECIPITATION AMOUNTS SHOULD REMAIN ON THE LIGHT
SIDE. HOWEVER...MODEL SOUNDINGS AND CROSS SECTIONS SHOW THAT AS
THE UPPER LOW IS MOVING OVERHEAD THROUGH THE EVENING HOURS...THE
MID LEVELS WILL BE FAIRLY UNSTABLE WHICH WILL ALLOW FOR STRONG
RISING MOTIONS IN RESPONSE TO THE DYNAMIC LIFT FROM THE UPPER LOW.
SKIES ACROSS THE PLAINS SHOULD GRADUALLY CLOUD OVER DURING THE
AFTERNOON WITH RAIN SHOWERS DEVELOPING LATE. RAIN WILL THEN
QUICKLY CHANGE OVER TO SNOW EARLY IN THE EVENING. GIVEN THE
CONVECTIVE NATURE OF THE SHOWERS...LIGHT TO MODERATE SNOW WILL BE
POSSIBLE ALONG THE FRONT RANGE URBAN CORRIDOR FOR A FEW HOURS IN
THE EVENING. SNOW ACCUMULATIONS UP TO 4 OR 5 INCHES CAN NOT BE
RULED OUT...BUT THE MORE LIKELY TOTALS WILL BE 1 TO 3 INCHES.
LATER IN THE EVENING...WINDS WILL SWITCH TO NORTHWESTERLY WHICH
WILL BRING DRYING ALONG THE URBAN CORRIDOR. MOUNTAIN AREAS SHOULD
RECEIVE LIGHT TO MODERATE SNOWFALL THROUGH TODAY AS THE LOW MOVES
OVERHEAD AND SNOW SHOWERS OVERNIGHT AS COLD ADVECTION CONTINUES IN
THE WAKE OF THE UPPER LOW.

LONG TERM...THE UPPER LEVEL STORM SYSTEM WILL MOVE QUICKLY
NORTHEAST OF THE AREA ON SUN HOWEVER SOME SNOW WILL LINGER OVER
THE FAR NERN PLAINS THRU MID MORNING BEFORE GRADUALLY ENDING BY
MIDDAY. WINDS WILL REMAIN VERY GUSTY THRU SUN AFTN SO EXPECT A LOT
OF BLOWING SNOW AND POOR VISBILITIES FM AKRON TO STERLING EASTWARD
SO WILL KEEP BLIZZARD WARNING THRU THE AFTN HOURS. ELSEWHERE SOME
OROGRAPHIC SNOW WILL CONTINUE IN THE MTNS DUE TO ABUNDANT MOISTURE
AND DECENT LAPSE RATES. ALONG THE FRONT RANGE DOWNSLOPE NWLY LOW
LVL FLOW WILL LIMIT PCPN CHANCES HOWEVER WINDS WILL BE GUSTY FM
THE WY BORDER SOUTHWARD ALONG I-25 TOWARD DENVER. AS FOR HIGHS
READINGS SHOULD STAY IN THE 30S ACROSS NERN CO.

AVIATION...CEILINGS WILL GRADUALLY LOWER THROUGH THE AFTERNOON
HOURS WITH A FAIR AMOUNT OF VIRGA PRECEDING SHOWERS THAT DEVELOP
AFTER 22Z. PRECIPITATION SHOULD BEGIN AS RAIN BUT THEN QUICKLY
CHANGE TO SNOW AFTER ABOUT 00Z. CEILINGS COULD DROP BELOW 6000
FEET AGL BY 22Z AND MAY THEN DROP TO MVFR BY 01Z. SNOW SHOWERS
THROUGH THE EVENING WILL DROP CEILINGS AND VSBYS INTO THE IFR
CATEGORY. IMPROVING CONDITIONS ARE EXPECTED AFTER 06Z. SNOW
ACCUMULATIONS OF 1 TO 3 INCHES CAN BE EXPECTED...BUT IF MULTIPLE
SNOW SHOWERS MOVE OVER THE AIRPORT...AMOUNTS UP TO 5 INCHES WILL
BE POSSIBLE.

.BOU WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FROM 5 PM THIS AFTERNOON TO 5 PM MST SUNDAY FOR
COZ048>051.

BLIZZARD WARNING FROM 5 PM THIS AFTERNOON TO 11 AM MST SUNDAY FOR
COZ042-044.

WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 11 AM MST
SUNDAY FOR COZ033-034.

WINTER WEATHER ADVISORY UNTIL 11 AM MST SUNDAY FOR COZ031.

SHORT TERM...DANKERS
LONG TERM....RPK
AVIATION/UPDATE...GIMMESTAD

AREA FORECAST DISCUSSION

NWS LINCOLN IL

210 PM CST SAT FEB 9 2013

.DISCUSSION...
ISSUED 210 PM CST SAT FEB 9 2013

PESKY LOW CLOUDS WHICH HAVE PLAGUED THE AREA RECENTLY FINALLY
HAVE BEEN SIGNIFICANTLY ERODING OVER THE LAST SEVERAL HOURS. EARLY
AFTERNOON SATELLITE IMAGERY SHOWING THEM MAINLY CONFINED TO AREAS
FROM THE ILLINOIS RIVER EAST TO CHAMPAIGN...ALTHOUGH THE REST OF
THESE CLOUDS SHOULD BE GONE BY LATE AFTERNOON. NOT MUCH BREAK IN
THE CLOUDS EXPECTED...AS MID AND HIGH CLOUDS WERE RAPIDLY
ADVANCING IN FROM THE SOUTHWEST. LARGE UPPER LOW SLOWLY ADVANCING
THROUGH THE 4 CORNERS REGION AND STILL ON TARGET TO AFFECT OUR
WEATHER LATE TONIGHT INTO EARLY NEXT WEEK.

SHORT TERM...TONIGHT THROUGH MONDAY...

MORNING MODELS REMAIN IN GOOD AGREEMENT WITH LIFTING THE UPPER LOW
INTO THE UPPER MISSISSIPPI VALLEY BY SUNDAY EVENING. SHOWERS ON
THE INCREASE ACROSS OKLAHOMA THIS AFTERNOON AND WILL BE ADVECTING
NORTHEAST TONIGHT AHEAD OF INTENSIFYING CYCLONE OVER THE PLAINS. A
LOT OF DRY AIR IN THE LOWER LEVELS NEEDS TO BE OVERCOME IN OUR
AREA...BUT RAP MODEL SOUNDINGS SHOW THE COLUMN MOISTENED UP IN
SPRINGFIELD BY 2 AM AND THE NORTHEASTERN CWA AROUND 4-5 AM. HAVE
INTRODUCED SOME SLIGHT CHANCE POPS IN THE FAR SOUTHWEST LATE THIS
EVENING...BUT HIGHER OVERNIGHT POPS REMAIN AFTER MIDNIGHT. HIGHEST
POPS DURING THE PERIOD WILL BE ON SUNDAY MORNING...WITH A RAPID
ENDING OF THE RAIN FROM WEST TO EAST DURING THE AFTERNOON. WILL
LINGER SOME SLIGHT CHANCE POPS INTO THE EVENING EAST OF I-57.

WINDS ARE ALSO A CONCERN DURING THE PERIOD. PRESSURE GRADIENT
TIGHTENS OVERNIGHT AS THE SURFACE LOW LIFTS NORTHEAST TO AROUND
OMAHA BY LATE SUNDAY MORNING. WILL LIKELY SEE SOME GUSTS OF AROUND
30-35 MPH LATE MORNING THROUGH MID AFTERNOON. WINDS WILL REMAIN
FAIRLY BREEZY AS THEY SWING AROUND TOWARD THE SOUTHWEST OR WEST
SUNDAY NIGHT...THEN GUSTS OF 30-40 MPH LIKELY AGAIN ON MONDAY.
HIGHEST GUSTS SHOULD BE ALONG AND NORTH OF THE I-74 CORRIDOR...
CLOSER TO THE SURFACE LOW.

LONG TERM...TUESDAY THROUGH SATURDAY...

SOUTHERN BRANCH OF THE JET STREAM STILL LOOKS TO BE THE ACTIVE ONE
MOST OF THIS WEEK...AS ANOTHER LOW IS DUG OUT OF THE DEEP TROUGH
IN THE SOUTHWEST U.S. AND MOVES EASTWARD TOWARD THE GULF COAST.
LONGER RANGE MODELS KEEP ANY OVERRUNNING PRECIP JUST TO OUR SOUTH
LATE TUESDAY NIGHT AND WEDNESDAY AS THE SURFACE LOW LIFTS TOWARD
THE MID-ATLANTIC COAST. MAIN FEATURE OF CONCERN IN THE EXTENDED IS
THE CARVING OUT OF A DEEP TROUGH OVER THE CENTER OF THE NATION
LATE THIS WEEK...MARKING A PERIOD OF COLDER WEATHER WHICH WILL
BEGIN FRIDAY AND LAST MUCH OF THE WEEKEND. THE GFS AND ECMWF
MODELS BOTH FORM A SURFACE REFLECTION IN THE TROUGH...BUT THE GFS
IS A LOT STRONGER AND FURTHER NORTH WITH ANY PRECIPITATION. SLIGHT
CHANCE POPS ARE STILL WARRANTED LATE IN THE WEEK DUE TO THE
UNCERTAINTY.

GEELHART

.AVIATION...
ISSUED 1146 AM CST SAT FEB 9 2013

MVFR OVERCAST WILL CONTINUE TO ERODE FROM THE E/SE THIS
AFTERNOON...AS SOUTHEASTERLY LOW-LEVEL FLOW PUSHES CLEARING LINE
CURRENTLY ACROSS EAST-CENTRAL ILLINOIS SLOWLY WESTWARD. BASED ON
SATELLITE TIMING TOOLS...CLOUDS WILL SCATTER AT KCMI BY 20Z...THEN
FURTHER WEST TO KDEC BY AROUND 22Z. FURTHER WEST...THINK LOW CLOUDS
WILL PERSIST UNTIL THEY ARE GRADUALLY MIXED OUT/PUSHED NORTHWARD
EARLY THIS EVENING. IN THE MEANTIME...MID/HIGH CLOUDS ASSOCIATED
WITH THE NEXT APPROACHING SYSTEM WILL QUICKLY SPREAD ACROSS THE
AREA DURING THE EVENING. 12Z NAM FORECAST SOUNDINGS SUGGEST LOW
CLOUDS WILL BE REPLACED BY A 12000FT OVERCAST BETWEEN 00Z AND 03Z.
AS PROFILE SLOWLY MOISTENS...CLOUDS WILL LOWER AND SHOWERS WILL
BEGIN TO DEVELOP FROM SOUTHWEST TO NORTHEAST AFTER MIDNIGHT. HAVE
INITIALLY INCLUDED A 4-HOUR TEMPO GROUP FOR VFR CEILINGS AND
SCATTERED SHOWERS BEFORE INTRODUCING PREDOMINANT RAIN TOWARD DAWN.
BASED ON NAM/GFS SOUNDINGS...STEADY RAIN WILL BEGIN AT KSPI BY
10Z...THEN FURTHER NORTHEAST TO KCMI BY 13Z. CEILINGS WILL BE A
BIT TRICKY...BUT WILL GO WITH LOW MVFR AT MOST SITES. WILL ONLY
CARRY IFR CEILINGS LESS THAN 1000FT AT KBMI FOR NOW. WINDS WILL
INITIALLY BE FROM THE S/SE AT 10 TO 15KT THIS AFTERNOON AND
EVENING...THEN WILL INCREASE TO 15 TO 25KT LATE TONIGHT INTO
SUNDAY.

BARNES

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS WICHITA KS

1200 PM CST SAT FEB 9 2013

.UPDATE...
CHANGE THE TIMING OF THE PRECIPITATION BASED ON THE 12Z AND 15Z
NWP AND CURRENT TRENDS. KICT 88D AND VISIBLE SATELLITE LOOP ENDING
AT 1750Z SHOWS CONVECTIVE LOOKING PRECIPITATION/CLOUDS MOVING INTO
SOUTH CENTRAL KANSAS. THE 15Z RAP IS PERFORM THE BEST WITH THIS
PRECIPITATION AT THIS TIME. NO HRRR MODEL RUN AVAILABLE SINCE
08.21Z.

WILL CONTINUE TREND OF BRINGING THE PRECIPITATION NORTHEAST INTO
AND THROUGH THE FORECAST AREA. THIS SHOULD GRADUALLY INCREASE IN
AREAL COVERAGE AND INTENSITY THIS EVENING AS LOW-LEVEL MOISTURE
TRANSPORT INCREASES...AFTER 10.00Z.

COOK

.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
CONVECTIVE PRECIPITATION NOW STARTING ACROSS SOUTHCENTRAL KANSAS.
THIS CONVECTION SHOULD MOVE NORTHEAST INTO CENTRAL KANSAS THIS
AFTERNOON. NO SIGNIFICANT RESTRICTION TO VSBYS ARE ANTICIPATED. CIGS
NEAR 1200 FEET IN CLOSE PROXIMITY TO THE PRECIPITATION.

INSTABILITY LIMITED SO ONLY ISOLATED THUNDER POSSIBLE AFTER 20Z.
WINDS WILL REMAIN SOUTH WITH THE STRONGEST WIND SPEEDS GUSTING TO
35 KNOTS AT KRSL AND KSLN.

COLD FRONT MOVES THROUGH TONIGHT...SHIFTING WINDS TO THE WEST AT
09Z AT KRSL TO 13Z AT KCNU. WINDS SUNDAY WILL BE STRONG
NORTHWESTERLY AT 25-35 KNOTS WITH GUSTS OVER 40 AT KRSL.

COOK

.PREV DISCUSSION... /ISSUED 523 AM CST SAT FEB 9 2013/

AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU

MAIN HAZARDS: STRONG SOUTHERLY WIND GUSTS TODAY-TONIGHT...THUNDERSTORM
POTENTIAL WITH LOW CLOUDS TONIGHT.

AS LOW PRESSURE DEVELOPS OVER EASTERN COLORADO...SOUTH-
SOUTHEASTERLY WINDS WILL INCREASE TODAY WITH GUSTS 35-40 KT IN
CENTRAL KS...AND AROUND 30 KT IN THE SOUTHEAST. A FEW
SPRINKLES/LIGHT SHOWERS ARE POSSIBLE MIDDAY INTO THE AFTERNOON. A
BAND OF SHOWERS/THUNDERSTORMS IS EXPECTED TO MOVE EASTWARD ACROSS
THE REGION TONIGHT. LOWER STRATUS WILL DEVELOP TONIGHT AS LOW-
LEVEL MOISTURE INCREASES AHEAD OF SURGING DRYLINE. 1000-1500 FT
AGL CIGS LOOK HIGHLY PROBABLE TONIGHT WITH A CHANCE FOR IFR. DID
NOT FEEL CONFIDENT ENOUGH TO FORECAST IFR GIVEN THE STRONG
SOUTHERLY WINDS HOLDING UP OVERNIGHT.

JMC

PREV DISCUSSION... /ISSUED 321 AM CST SAT FEB 9 2013/

DISCUSSION...

A SHORTWAVE TROUGH OVER THE SOUTHWEST EARLY THIS MORNING IS PROGGED
TO MOVE EAST/NORTHEAST INTO THE CENTRAL ROCKIES THIS EVENING.
MEANWHILE...LOW PRESSURE WILL DEEPEN OVER THE HIGH PLAINS OF EASTERN
COLORADO LEADING TO STRONG SOUTHERLY WINDS ACROSS MUCH OF THE
SOUTHERN AND CENTRAL PLAINS STATES. A WIND ADVISORY WILL REMAIN IN EFFECT
FOR MUCH OF CENTRAL AND WESTERN KANSAS WHILE WINDS MAY FLIRT WITH
ADVISORY LEVEL CONDITIONS AS FAR EAST AS THE KANSAS TURNPIKE. WITH A
FEW BREAKS IN THE CLOUDS...HIGHS MAY RISE INTO THE LOW 50S BUT
CONFIDENCE IN THIS SCENARIO REMAINS LOW AND GENERALLY TRENDED
SLIGHTLY LOWER WITH VALUES IN THE 48-53 DEGREE RANGE ANTICIPATED.

TONIGHT...MOISTURE TRANSPORT/MUCAPE CONTINUE TO BE MAXIMIZED
ACROSS THE AREA TONIGHT WITHIN DIFFLUENT MID/UPPER FLOW EAST OF A
NEUTRAL TO SLIGHTLY NEGATIVELY TILTED H5 TROUGH AS IT EMERGES OUT OF
THE ROCKIES AND OVER THE CENTRAL PLAINS. GENERALLY FOLLOWED THE PREVIOUS
FORECAST AND TRIED TO PROVIDE MORE TIMING BRINGING AN END TO
PRECIPITATION ACROSS MUCH OF THE AREA AFTER 09Z AS A DRY SLOT
WRAPS INTO THE DEVELOPING MID-LATITUDE CYCLONE. WITH MUCAPE 300-600
J/KG WE ARE STILL EXPECTING SOME EMBEDDED THUNDERSTORMS BUT STRONG
STORMS SHOULD REMAIN LIMITED.

SUNDAY...ANOTHER WINDY DAY APPEARS LIKELY IN THE WAKE OF THE
DRYLINE/PAC FRONT AND A WIND ADVISORY WILL LIKELY BE ISSUED FOR MUCH
OF THE AREA. THE WESTERLY WINDS WILL ADVECT DRIER AIR ACROSS THE
AREA HELPING TEMPERATURES TO CLIMB TO ABOVE NORMAL READINGS WITH
HIGHS IN THE 50S AND 60S ACROSS MUCH OF THE AREA. PORTIONS OF
CENTRAL KANSAS MAY STILL BE IMPACTED BY CLOUDS BUT THE PRECIPITATION
SHIELD IS EXPECTED TO REMAIN NORTH OF THE AREA AT THIS TIME. CLOUD
COVER MAY IMPACT HIGHS ALONG THE I-70 CORRIDOR ON SUNDAY WHERE
TEMPERATURES MAY STRUGGLE TO CLIMB OUT OF THE 40S.

MONDAY-FRIDAY...TEMPERATURES BEHIND THE COLD FRONT WILL RETURN TO
MORE SEASONABLE VALUES EARLY IN THE WEEK WITH HIGHS MAINLY IN THE
40S. ANOTHER SHORTWAVE TROUGH IS EXPECTED TO IMPACT PORTIONS OF THE
SOUTHERN PLAINS BUT PRECIPITATION ASSOCIATED WITH THIS SYSTEM IS
EXPECTED TO REMAIN MOSTLY SOUTH OF THE OKLAHOMA STATE LINE. THERE IS
STILL SOME UNCERTAINTY IN THE TRACK OF THIS SYSTEM AND MAINTAINED
LOW POPS FOR A STRAY SHOWER NEAR THE OK STATE LINE ON TUESDAY.

SHORTWAVE MID/UPPER RIDGING WILL RETURN TO THE CENTRAL PLAINS ON WED
WITH RISING HEIGHTS/INCREASING THICKNESS SUPPORTING RISING
TEMPERATURES ACROSS THE AREA. MORE UNCERTAINTY ARRIVES LATER IN THE
WEEK AS ANOTHER TROUGH IS PROGGED TO BUILD SOUTH ACROSS THE CENTRAL
CONUS WITH A SERIES OF SHORTWAVE TROUGHS HELPING TO DRIVE A COLDER
CANADIAN AIRMASS SOUTH ACROSS THE AREA. MAINTAINED LOW PROBABILITIES
FOR SOME LIGHT PRECIPITATION BUT UNCERTAINTY REMAINS HIGH AT THIS
TIME.

MCGUIRE

.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 49 45 54 28 / 50 70 10 0
HUTCHINSON 50 42 51 27 / 50 70 0 0
NEWTON 48 44 51 28 / 50 70 10 0
ELDORADO 48 46 54 28 / 40 70 10 0
WINFIELD-KWLD 49 46 58 28 / 50 70 10 0
RUSSELL 53 35 48 24 / 50 70 10 0
GREAT BEND 53 37 48 24 / 50 70 10 0
SALINA 52 43 50 28 / 50 70 10 0
MCPHERSON 50 43 50 28 / 50 70 10 0
COFFEYVILLE 49 48 64 33 / 40 80 20 0
CHANUTE 49 48 60 32 / 40 80 20 0
IOLA 49 48 59 32 / 30 80 20 0
PARSONS-KPPF 49 48 63 31 / 40 80 20 0

.ICT WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CST THIS EVENING FOR KSZ032-033-047-048-
050.

AREA FORECAST DISCUSSION

NWS TOPEKA KS

1134 AM CST SAT FEB 9 2013

...UPDATE TO AVIATION...

.DISCUSSION...

MAIN FORECAST CHALLENGES ARE PRECIPITATION CHANCES AND WIND SPEEDS
THROUGH SUNDAY AFTERNOON.

.AVIATION...

PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN ACROSS THE AREA
CAUSING THE WINDS TO INCREASE THIS AFTERNOON OUT OF THE SOUTHEAST
AROUND 17 KTS WITH GUSTS UP TO 25 KTS. MOISTURE WILL ALSO INCREASE
FROM THE SOUTH AS THE MAIN SYSTEM PASS NORTH OF THE AREA. EXPECT
SHOWERS TO DEVELOP THIS EVENING AROUND 06Z AND CONTINUE UNTIL 12Z.
CAN NOT RULE OUT ISOLATED TSRA OVERNIGHT AS WELL. THERE MAY BE
BRIEF PERIODS OF MVFR CIGS DURING THE SHOWER ACTIVITY BUT WILL
BECOME VFR AROUND 12Z. THE WINDS WILL INCREASE TOMORROW MORNING
OUT OF THE SOUTHWEST AS THE DRY SLOT MOVES THROUGH THE AREA.

SANDERS

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

AREA FORECAST DISCUSSION

NWS GAYLORD MI

130 PM EST SAT FEB 9 2013

.SYNOPSIS...
ISSUED AT 312 AM EST SAT FEB 9 2013

.UPDATE...
ISSUED AT 129 PM EST SAT FEB 9 2013

GOING FORECAST STILL IN GOOD SHAPE. REMAINING LAKE CLOUDS OVER
LAKES MICHIGAN AND HURON STILL WELL OFFSHORE FROM LOWER MICHIGAN THANKS
TO LAND BREEZE COMPONENT...LEAVING ABUNDANT SUNSHINE AND RAPIDLY
WARMING TEMPS ACROSS NRN LOWER MICHIGAN. UPPER MICHIGAN GETTING
RIPPED OFF HOWEVER...AS SOUTHERLY MEAN LOW LEVEL WIND IS DRAGGING
LAKE CLOUDS UP THROUGH A GOOD PART OF EASTERN UPPER. NO RECENT
SIGNS OF SNOW SHOWERS HOWEVER. LAKE CLOUDS OFF LAKE MICHIGAN MAY
EVENTUALLY MAKE A PUSH TOWARD NW LOWER MICHIGAN AS WE GET MORE OF
A WESTERLY COMPONENT. BUT THAT LOOKS TO BE A NUMBER OF HOURS OFF
STILL.

UPDATE ISSUED AT 1044 AM EST SAT FEB 9 2013

UPDATE ISSUED AT 642 AM EST SAT FEB 9 2013

STILL QUITE CHILLY BUT (MAINLY) QUIET OUT THERE. FLURRIES PERSIST
NEAR ROGERS CITY...AND SOME FOG IS SEEN IN SOUTHERN SECTIONS OF
THE FORECAST AREA. NEITHER OF THESE WILL LAST MUCH PAST DAYBREAK.

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 312 AM EST SAT FEB 9 2013

HIGH IMPACT WEATHER POTENTIAL: NIL.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 312 AM EST SAT FEB 9 2013

MAX TEMPS 30 TO 40F. INCREASING SE/ESE WIND WILL BE STRONGEST IN
EASTERN UPPER.

BY DAYBREAK...DEEPER MOISTURE WILL BE WRAPPING BACK INTO PARTS OF NW
LOWER...THOUGH THE SURFACE-BASED ABOVE-FREEZING LAYER UP THRU 900MB
SHOULD STILL KEEP THINGS LIQUID.

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 129 PM EST SAT FEB 9 2013

SOLID VFR CONDITIONS ANTICIPATED AT THE TERMINAL SITES THROUGH THE
BALANCE OF THE AFTERNOON...WITH JUST SOME HIGH CIRRUS OVERHEAD.

TONIGHT...INCREASING SSW FLOW OFF THE SFC WILL BRING ABOUT
MARGINAL LLWS CONDITIONS TO ALL TERMINAL SITES. BIGGER QUESTION
ABOUT CLOUD COVER HOWEVER. AS WE GET MORE OF A WESTERLY COMPONENT
OFF LAKE MICHIGAN...FORECAST SOUNDINGS SUGGEST THAT INCREASED LOW
LEVEL MOISTURE GETS PULLED INTO NRN LOWER MICHIGAN (DEWPOINT TRACE
FOLDS OVERTOP THE BOUNDARY LAYER) THROUGH THE NIGHT...SUGGESTING
THE POSSIBILITY OF DEVELOPMENT OF LOW STRATUS. SO...CIG FORECAST
CONFIDENCE IS NOT HIGH. HAVE INDICATED THE POTENTIAL WITH INCLUSION
OF SCT LOW CLOUDS LATER THIS EVENING (BKN AT MBL). HIGHEST POTENTIAL
FOR LOW CLOUD DEVELOPMENT WILL LIKELY OCCUR AT PLN/MBL/TVC WHERE
LOW LEVEL FLOW TRAJECTORIES WILL BE MOST FAVORABLE OFF THE LAKE.

SUNDAY...ANY LOW CLOUDS SHOULD GET PUSHED NORTHWARD/ERODE FROM THE
SOUTH THROUGH THE MORNING HOURS AS STRONG LOW LEVEL WARM ADVECTION
PROCEEDS. SO...ANTICIPATE A TRANSITION BACK TO VFR CONDITIONS BY NOON.

.MARINE...
ISSUED AT 312 AM EST SAT FEB 9 2013

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

UPDATE...BA
SYNOPSIS...JA
SHORT TERM...JA
LONG TERM...JZ
AVIATION...BA
MARINE...JA

AREA FORECAST DISCUSSION

NWS TWIN CITIES/CHANHASSEN MN

229 PM CST SAT FEB 9 2013

.DISCUSSION...
MAIN CONCERN CONTINUES TO BE THE SIGNIFICANT WINTER STORM EXPECTED
TO IMPACT THE AREA FROM LATE TONIGHT INTO MONDAY. THE LATEST WATER
VAPOR IMAGERY AND RAP UPPER AIR ANALYSES SHOW THE FEATURE OF
INTEREST MAKING ITS WAY THROUGH THE SOUTHERN ROCKIES AT THE
CURRENT TIME... WITH A NICE RIDGE DEVELOPING AHEAD OF IT ACROSS
THE NORTHERN PLAINS. THE SHORTENING WAVELENGTH BETWEEN THESE
FEATURES WILL BE COINCIDENT WITH THE SYSTEM DEEPENING AND MOVING
NORTHEAST TOWARD OUR AREA... AND WILL MANIFEST ITSELF IN A PERIOD
OF STRONG FORCING LATE TONIGHT THROUGH THE DAY ON SUNDAY. THERE
CONTINUES TO BE SOME UNCERTAINTY IN PRECIPITATION TYPE WITH THIS
SYSTEM... ALTHOUGH THE 12Z GUIDANCE HAS COME INTO GOOD AGREEMENT
ON TRACKING THE SURFACE LOW ACROSS IOWA AND FAR SOUTHEAST
MINNESOTA AND INTO CENTRAL WISCONSIN SUNDAY INTO SUNDAY EVENING.
THE REMAINING DIFFERENCES REVOLVE AROUND HOW THE THERMAL PROFILE
WILL EVOLVE THROUGH THE EVENING... PARTICULARLY FROM THE SURFACE
TO 925MB. THE GFS CONTINUES TO BE WARMEST IN THAT LAYER... WITH
THE ECMWF... NAM... AND GEM SUGGESTING THINGS WILL BE COOLER AND
MOSTLY SNOW ACROSS MOST OF THE AREA. GENERALLY FOLLOWED A BLEND OF
THE ECMWF AND NAM FOR THE FORECAST DETAILS... WITH SOME ADDITIONAL
RELIANCE ON THE HIGH RESOLUTION WINDOW RUNS AND LOCAL 4KM GUIDANCE.

EXPECT PCPN TO OVERSPREAD THE CWFA OVERNIGHT INTO SUNDAY
MORNING... WITH SOME FREEZING RAIN POSSIBLE INITIALLY ACROSS
SOUTHERN AND EASTERN MINNESOTA BEFORE THE ELEVATED WARM LAYER
SATURATES AND COOLS TO BELOW FREEZING WET BULB VALUES. AFTER THAT
POINT... IT LOOKS LIKE THE MAIN CHANCES FOR MIXED PCPN WILL BE
FROM NEAR THE TWIN CITIES SOUTH AND EAST... WHERE THE ELEVATED
WARM LAYER WILL FLIRT WITH 0C AT TIMES AND NEAR SURFACE
TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE FREEZING. THE
WESTERN AND NORTHERN PORTIONS OF THE AREA LOOK TO BE SNOW FOR THE
ENTIRE EVENT... AND WITH THE MAIN MID-LEVEL DEFORMATION ZONE AND
ASSOCIATED FRONTOGENESIS IMPACTED THOSE AREAS... STILL EXPECT THE
BEST SNOW AMOUNTS TO OCCUR OVER THE FAR WEST AND NORTHWEST PART OF
THE AREA. PCPN ACROSS THE CENTRAL AND EASTERN CWFA... INCLUDING
THE TWIN CITIES... WILL BE PRIMARILY FORCED BY THE SURGE OF STRONG
WARM ADVECTION/ISENTROPIC LIFT SUNDAY MORNING... ALONG WITH A
DECENT AREA OF UPPER DIVERGENCE IN THE LEFT EXIT REGION OF THE
APPROACHING JET. THALER QG DIAGNOSTICS ARE VERY CONSISTENT BETWEEN
THE VARIOUS GUIDANCE SOURCES... AND ALL PUSH A STRONG SLUG OF QG-
OMEGA ACROSS THE CWFA DURING THE MORNING AND EARLY AFTERNOON
HOURS. THE MID-LEVEL DRY SLOT ASSOCIATED WITH THE UPPER JET STILL
LOOKS LIKE IT SHOULD IMPACT AT LEAST THE SOUTHEAST THIRD OR SO OF
THE CWFA... LIKELY FROM AROUND THE TWIN CITIES METRO SOUTH/EAST...
DURING THE AFTERNOON HOURS. THAT COULD BRING A PERIOD OF SOME
DRIZZLE OR FREEZING DRIZZLE... BUT AT THIS POINT DIDN/T TRY TO
WORK THAT INTO THE FORECAST GIVEN THE MORE SIGNIFICANT PCPN WHICH
WILL OCCUR PRIOR TO THAT AND SOME SNOW WITH THE UPPER LOW
AFTERWARD. AS THE DRY SLOT PUNCHES IN TOWARD THE AREA WE WILL SEE
CONVECTIVELY INSTABILITY INCREASE DRAMATICALLY JUST AHEAD OF IT AS
THE DRY AIR MOVES IN ABOVE THE MOIST BOUNDARY LAYER AND LOWER
TROPOSPHERE. SHOWALTER INDICES ACTUALLY DIP TO AROUND OR A BIT
BELOW ZERO OVER THE SOUTHEAST PORTION OF THE CWFA DURING THE
AFTERNOON... SO WOULDN/T BE SURPRISED IF SOME THUNDER OCCURRED.
ALSO LEFT THAT OUT OF THE FORECAST FOR NOW... BUT IT IS CERTAINLY
WORTH KEEPING AN EYE ON... SINCE ANY BURST OF CONVECTION WOULD
LIKELY CHANGE ANY LINGERING MIXED PCPN OVER TO SNOW AND COULD
AUGMENT PCPN TOTALS ACROSS THE SOUTHERN AND EASTERN PORTIONS OF
THE WINTER STORM WARNING AREA.

EXPECT TO SEE SOME SNOW PERSIST INTO SUNDAY NIGHT ON THE BACKSIDE
OF THE LOW... WITH SNOW SHOWERS LINGERING INTO MONDAY WITH THE
CYCLONIC FLOW. THE PRESSURE GRADIENT WILL TIGHTEN LATE SUNDAY
NIGHT INTO MONDAY... WITH 925MB WINDS INCREASING TO 30-40 KT
ACROSS MUCH OF THE WESTERN AND SOUTHWESTERN CWFA. KEPT THE
BLIZZARD WATCH GOING TO ACCOUNT FOR THE POSSIBILITY OF BLIZZARD
CONDITIONS FROM THE SNOW SHOWERS AND BLOWING SNOW LATE SUNDAY
NIGHT INTO MONDAY. DIDN/T WANT TO BLANKET THE ENTIRE TIME FRAME
WITH A BLIZZARD WARNING... SINCE MOST OF THE SNOW WILL OCCUR
SUNDAY PRIOR TO WHEN WINDS ARE EXPECTED TO INCREASE. SO... IT
SEEMED THE MOST LOGICAL WAY TO DO THINGS FOR NOW WAS TO GO WITH
THE WINTER STORM WARNING WHILE KEEPING A BLIZZARD WATCH FOR THE
LATER TIME FRAME.

RIDGING SHOULD BRING QUIET WEATHER FOR THE MIDDLE PART OF THE
WEEK... WITH AN ALBERTA CLIPPER DROPPING INTO THE REGION FOR THE
THURSDAY-FRIDAY TIME FRAME. INCLUDED A CHANCE OF SOME SNOW FROM
THURSDAY INTO FRIDAY AS THIS SYSTEM MOVES ACROSS THE REGION. THERE
REMAIN SOME DIFFERENCES BETWEEN THE ECMWF AND GFS... SO DON/T SEE
MUCH REASON TO GO WITH ANYTHING MORE THAN CHANCE POPS AT THIS
POINT. TEMPERATURES THROUGH THE WEEK LOOK SEASONABLE... EXCEPT
BEHIND THE CLIPPER FRIDAY INTO SATURDAY WHEN BELOW NORMAL
TEMPERATURES ARE EXPECTED TO RETURN TO THE AREA.

.AVIATION.../18Z TAF ISSUANCE/
/ISSUED 1217 PM CST SAT FEB 9 2013/
IFR OR LOW-END MVFR CONDITIONS TO PREVAIL THRU LATE EVENING THEN
CONDITIONS BECOME IFR AND WORSE TONIGHT THRU TMRW AS A POTENT
WINTER STORM ENVELOPS THE AREA. LOW CLOUDS SLOWLY SLIDING EWD
WHILE LOW LEVEL FLOW IS FROM THE SOUTH. CLEARING EDGE IN WRN IA
INTO EXTREME SE SD NOT EXPECTED TO MOVE THIS FAR N...SO HAVE KEPT
LOW CLOUDS GOING FOR ALL SITES. GFS GUIDANCE TRIES TO BRING IN VFR
CEILINGS THIS EVENING BUT AM NOT BUYING IT DUE TO SUCH LOW LEVEL
MOISTURE BEING ADVECTED INTO THE REGION...SO THESE TAFS HAVE A
MORE NAM/SREF FEEL. PRECIP WILL BEGIN IMPACTING THE TAF SITES ARND
06Z...THEN GRADUALLY SPREAD EWD. NRN TAF SITES /KAXN-KSTC/ SHOULD
HAVE NO PROBLEM STAYING AS SNOW THE ENTIRE DURATION OF PRECIP. THE
REST OF THE TAF SITES...WITH LATER START TIMES...WILL DEAL WITH A
MIX OF P-TYPES UNTIL LATE SUNDAY EVENING. PRECIP THAT STARTS AS
FZRA SHOULD CHANGE OVER TO SN OR SNPL AS THE COLUMN COOLS FROM THE
TOP DOWN...EVEN IF SFC TEMPS ARE SEVERAL DEGREES BELOW FREEZING AT
THE START. PRECIP WILL LIKELY BE HEAVY AT TIMES DURG THE DAY TMRW
AS LIFT IS ENHANCED WITH THE LOW MOVING ACRS SO HAVE MAINTAIN THE
OCNL 1/2SM OR 1/4SM FOR MOD-HVY SNOW. CONDITIONS WILL CERTAINLY
REMAIN DEGRADED TMRW AND LIKELY THRU TMRW NIGHT.

KMSP...MVFR CONDS DUE TO CEILINGS WILL CONTINUE MOST OF THE NIGHT.
HAVE ALSO KEPT CEILINGS BELOW THE 017 THRESHOLD...DESPITE THAT GFS
GUIDANCE TRIES TO BRING IN 040-070 CEILINGS. AM NOT GOING THAT
ROUTE AFTER EXAMINING FULL SUITE OF MODEL GUIDANCE AND COLLAB WITH
CWSU ZMP. CONDITIONS DROP TO IFR BEFORE DAYBREAK AS THE PRECIP IS
EXPECTED TO START AS FZRA WITH SN MIXED IN WHILE THERE IS A
SHALLOW WARM LAYER. THIS LAYER WILL DISSIPATE AS THE PRECIP
CONTINUES...CHANGING IT TO A SNOW/SLEET MIX BY LATE MRNG. AS SOME
LARGER SCALE WARMER AIR SHIFTS IN...PRECIP MAY TAKE ON A RAIN/SNOW
MIX BEFORE CHANGING TO ALL SNOW LATE IN THE DAY. MAY BE A FEW
BURSTS OF MOD-HVY PRECIP DURING THIS TIME. WINDS WILL BECOME
SOUTHEAST THEN EAST THRU THE NEXT 30 HRS...WITH SUSTAINED SPEEDS
IN THE 10-15 KT RANGE.

/OUTLOOK FOR KMSP/
SUN NGT...IFR/LIFR WITH SN. NE WIND 10 KTS BCMG NW 15 KTS.
MON...IFR WITH -SN EARLY...THEN MVFR WITH -SN/BLSN. NW WINDS 17G25KTS.
TUE...VFR. WINDS W AT 5-10 KTS.

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST MONDAY
FOR BLUE EARTH-LE SUEUR-RICE-SCOTT-WASECA-WATONWAN.

WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO MIDNIGHT CST
SUNDAY NIGHT FOR BROWN-CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI
PARLE-NICOLLET-POPE-REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-
YELLOW MEDICINE.

BLIZZARD WATCH FROM LATE SUNDAY NIGHT THROUGH MONDAY AFTERNOON
FOR BROWN-CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-NICOLLET-
POPE-REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-YELLOW MEDICINE.

WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM CST MONDAY
FOR CARVER-MCLEOD-MEEKER-STEARNS-TODD-WRIGHT.

WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 AM CST MONDAY
FOR ANOKA-BENTON-CHISAGO-HENNEPIN-ISANTI-KANABEC-MILLE LACS-
MORRISON-RAMSEY-SHERBURNE-WASHINGTON.

WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 3 PM CST SUNDAY
FOR FARIBAULT-FREEBORN-MARTIN-STEELE.

WINTER WEATHER ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR GOODHUE.

WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT CST
SUNDAY NIGHT FOR DAKOTA.

WI...WINTER WEATHER ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE.

WINTER STORM WARNING FROM 6 AM SUNDAY TO 6 AM CST MONDAY FOR
BARRON-POLK-RUSK-ST. CROIX.

AREA FORECAST DISCUSSION

NWS RALEIGH NC

245 PM EST SAT FEB 9 2013

.SYNOPSIS...
HIGH PRESSURE WILL SETTLE OVER THE EAST COAST TONIGHT THROUGH SUNDAY
MORNING... BEFORE SHIFTING OFFSHORE SUNDAY AFTERNOON. A STORM SYSTEM
WILL APPROACH FROM THE WEST LATE SUNDAY AND SWEEP THROUGH THE AREA
SUNDAY NIGHT AND MONDAY. YET ANOTHER SYSTEM WILL AFFECT THE REGION
TUESDAY NIGHT AND WEDNESDAY.

.NEAR TERM /THROUGH SUNDAY/...
AS OF 920 AM SATURDAY...

.SHORT TERM /MONDAY THROUGH TUESDAY/...
AS OF 235 PM SATURDAY...

ONGOING PRECIPITATION MONDAY MORNING ASSOCIATED WITH DISTURBED
SOUTHWESTERLY FLOW ALOFT AND WARM ADVECTION/ISENTROPIC LIFT WILL
SHIFT EAST BY MIDDAY AS THE COR OF THE LLJ MOVES OFFSHORE. THE
MODEL CONSENSUS WOULD HAVE PRECIP COMPLETELY OUT OF THE EASTERN CWA
BY MID AFTERNOON WITH INCREASINGLY WESTERLY DEEP LAYER FLOW. TEMPS
ARE THE BIGGER FORECAST STRUGGLE...AS EARLY MORNING PRECIP FALLING
INTO THE DRY AIRMASS DEPOSITED BY A 1030MB SHIFTING OFFSHORE MONDAY
MORNING WOULD SUPPORT THE POTENTIAL FOR A WEAK IN-SITU WEDGE
AIRMASS. THE HIGH IS NOT IN A FAVORABLE LOCATION TO SUPPORT THIS
AND MODELS WANT TO MIX THE WARM SECTOR THROUGH THE AREA RATHER
QUICKLY MONDAY MORNING....EVIDENCE BY THE LATEST MAV MOS FORECASTING
LOW TO MID 70S. HOWEVER...THIS IS OFTEN A DEFICIENCY IN THE MODELS
AND LOWERS CONFIDENCE IN THE CURRENT FORECAST. WILL CONTINUE TO ERR
ON ON THE COOL SIDE...MORE INLINE WITH MET MOS.

THE COLD FRONT WILL SWEEP ACROSS THE AREA MONDAY EVENING...SCOURING
MOST OF THE LINGERING LOW CLOUDS.... AND EVENTUALLY STALLING SOUTH
OF THE AREA. THE GFS REMAINS DRY THROUGH TUESDAY...WHILE THE
NAM/ECMWF/SREF MEAN BRING ANOTHER WAVE ALONG THE FRONTAL ZONE WITH
RAIN CROSSING SC AND SOUTHEASTERN NC MONDAY NIGHT/EARLY TUESDAY.
THE WAVE IS SUBTLE IN MODEL GUIDANCE...SO ITS DIFFICULT TO ASSESS
HOW FAR NORTH PRECIP WILL REACH .WILL KEEP A SLIGHT CHANCE POP
ACROSS THE SOUTH MONDAY NIGHT...WITH DRY CONDITIONS ON TUESDAY.
LOWS MONDAY NIGHT MOSTLY IN THE MID TO UPPER 40S. HIGHS TUESDAY IN
THE UPPER 50S AND LOWER 60S.

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM SATURDAY...

AN ACTIVE PATTERN WILL CONTINUE THROUGH LATE NEXT WEEK AS BOTH THE
NORTHERN AND SOUTHERN STREAM SUPPLY DISTURBANCES WITHIN A BROAD AND
STRENGTHENING MEAN TROUGH COVERING MOST OF THE CONUS. MODELS ARE IN
GOOD AGREEMENT ON A A PIECE OF ENERGY EJECTING OUT OF THE ROCKIES
AND RUSHING EAST AND SHEARING OUT AS IT CROSSES OUR AREA WEDNESDAY.
WEAK LOW PRESSURE ALONG THE GULF COAST SHOULD TRACK ALONG A STALLED
OUR FRONT OVER THE SOUTHEAST US AND BE OFF THE CAROLINA/VA BY
WEDNESDAY EVENING. PRECIP IS EXPECTED TO BE MOSTLY LIGHT ON THE
COOL SIDE OF THE FRONT AND SURFACE LOW...WITH FORECAST SOUNDINGS
SHOWING A WARM LAYER BELOW 10K FT THAT WOULD KEEP PRECIP
PREDOMINATELY LIQUID. THE ECMWF DOES BRING THE 1000-850MB THICKNESS
DOWN TO NEAR 1300M WEDNESDAY EVENING DUE A MORE SUPPRESSED TRACK OF
THE 850MB WAVE....WHICH ESSENTIALLY TRACKS OVER OR JUST TOT HE
SOUTHEAST OF THE CWA. HOWEVER...THIS WOULD BE ON THE TAIL END OF
THE DEEPER MOISTURE...SO WILL KEEP PRECIP ALL LIQUID AND MONITOR
FUTURE TRENDS IN THE LOW TRACK/STRENGTH.

COOL HIGHS ON WEDNESDAY WILL SLOWLY TREND UPWARD TO SLIGHTLY ABOVE
NORMAL THURSDAY AND FRIDAY BEFORE THE UPPER TROUGH BEGINS TO AMPLIFY
AND SHIFT TOWARD THE EAST COAST NEXT WEEKEND. MODELS ARE
ADVERTISING THE POTENTIAL FOR A STRONG EAST COAST STORM...AND WHILE
THE DETAILS OF ITS IMPACT ARE STILL UNCERTAIN...CURRENT MODEL
PROJECTIONS SHOW CYCLOGENESIS MORE TOWARD THE MID ATLANTIC
COAST...WITH LESS QPF OVER THE CAROLINAS BUT TEMPS BELOW NORMAL.

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 1230 PM SATURDAY...

HIGH CONFIDENCE THAT VFR CONDITIONS WILL HOLD THROUGH SUNDAY.
SURFACE HIGH PRESSURE AND RIDGING ALOFT WILL KEEP SKIES CLEAR INTO
THIS EVENING. WINDS FROM THE NW AND WNW AT SPEEDS VARYING FROM 5 TO
10 KTS SUSTAINED WITH PERIODIC GUSTS TO 15-18 KTS WILL DIMINISH BY
21Z TO LIGHT MAINLY FROM THE NORTH BY EVENING BEFORE SWINGING AROUND
TO EAST THEN SE TONIGHT. THE STORM SYSTEM NOW OVER THE SOUTHWEST
STATES WILL SHIFT ENE THROUGH TONIGHT AND AS IT APPROACHES... HIGH
CLOUDS WILL INCREASE AND THICKEN WITH LOWERING BASES TO AROUND 12
THOUSAND FT AGL BY SUNDAY AFTERNOON.

LOOKING BEYOND 18Z SUNDAY... GOOD CHANCE OF CIGS/VSBYS DROPPING TO
IFR/LIFR WITHIN AREAS OF RAIN SUNDAY EVENING AS LOW LEVEL FLOW FROM
THE S AND SW INCREASES AHEAD OF THE INCOMING FRONTAL SYSTEM. THESE
STRONG LOW LEVEL WINDS MAY INDUCE MECHANICAL TURBULENCE. SUB-VFR
CONDITIONS WILL HOLD THROUGH MIDDAY MONDAY BEFORE LIKELY IMPROVING
TO VFR BEHIND THE FRONT DURING MONDAY AFTERNOON. YET ANOTHER STORM
SYSTEM MAY BRING ANOTHER ROUND OF SUB-VFR CONDITIONS LATE TUESDAY
NIGHT THROUGH WEDNESDAY... FOLLOWED BY A POSSIBLE TREND BACK UP TO
VFR BY THURSDAY. -GIH

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/BSD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...HARTFIELD

AREA FORECAST DISCUSSION

NWS RALEIGH NC

1230 PM EST SAT FEB 9 2013

.NEAR TERM /THROUGH SUNDAY/...
AS OF 920 AM SATURDAY...

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 300 AM SATURDAY...

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 327 AM SATURDAY...

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 1230 PM SATURDAY...

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...HARTFIELD

AREA FORECAST DISCUSSION

NWS HOUSTON/GALVESTON TX

357 PM CST SAT FEB 9 2013

.DISCUSSION...
GUSTY SOUTHEAST SURFACE WINDS THIS AFTERNOON AS STRONG MOISTURE
ADVECTION CONTINUES AHEAD OF AN APPROACHING UPPER LEVEL SYSTEM. A
FEW SHOWERS AND THUNDERSTORMS DEVELOPED ALONG THE WARM FRONT
EARLIER THIS AFTERNOON AS IT LIFTED NORTH OF THE REGION. THE WARM
FRONT IS CURRENTLY ALONG A LINE FROM JUST SOUTH OF WICHITA FALLS
TO DALLAS TO NACOGDOCHES...WITH A DRYLINE SETTING UP ACROSS WEST
TEXAS. THIS DRYLINE WILL SERVE AS THE INITIAL FOCUS FOR
THUNDERSTORM DEVELOPMENT LATER THIS EVENING AS A PACIFIC FRONT
OVERTAKES IT FROM THE WEST.

ONLY VERY LIGHT SHOWERS ONGOING ACROSS SOUTHEAST TEXAS THIS
AFTERNOON AND THIS WILL CONTINUE THROUGH MUCH OF THE EVENING AS A
CAPPING INVERSION REMAINS IN PLACE ACROSS OUR REGION. ACARS
SOUNDINGS FOR IAH AND HOU SHOW TWO DISTINCT TEMPERATURE INVERSIONS
NEAR 850 AND 700MB ALTHOUGH LATEST DATA SUGGEST SOME WEAKENING OF
THESE FEATURES AS WE APPROACH LATE AFTERNOON. THE GFS IS HINTING
AT A WEAK SHORTWAVE MOVING ACROSS OUR NORTHERN COUNTIES AROUND
MIDNIGHT TONIGHT AND LATEST HRRR RUNS SHOW AN AREA OF SHOWERS AND
THUNDERSTORMS DEVELOPING ACROSS CENTRAL TEXAS OVERNIGHT AHEAD OF
THE APPROACHING FRONTAL BOUNDARY. THIS ACTIVITY WILL INCREASE IN
COVERAGE TOWARDS DAYBREAK AS THE FRONTAL BOUNDARY APPROACHES OUR
REGION. THE GREATEST COVERAGE AND GREATEST POTENTIAL FOR ANY
STRONG TO SEVERE THUNDERSTORMS ACROSS OUR REGION IS STILL EXPECTED
TO BE ACROSS AREAS TO THE NORTH AND EAST OF A LINE FROM BRYAN TO
GALVESTON. AREAS FURTHER TO THE SOUTH AND WEST WILL BE MORE CAPPED
AND COVERAGE WILL BE LIMITED. THE GREATEST THREAT FROM THESE
THUNDERSTORMS WILL BE STRONG DAMAGING WINDS...AS THE LOW LEVEL
FLOW WILL REMAIN QUITE STRONG ACROSS OUR REGION. RAIN CHANCES WILL
END BY SUNDAY AFTERNOON AS THE FRONT SWEEPS THROUGH SOUTHEAST
TEXAS.

WHILE THE FRONT MOVES THROUGH OUR REGION THE ASSOCIATED UPPER
LEVEL LOW WILL MOVE RAPIDLY TO THE NORTHEAST. IN ITS WAKE ANOTHER
SHORTWAVE WILL MOVE INTO THE BASE OF THE UPPER TROUGH AND DIG INTO
THE DESERT SOUTHWEST. RAIN CHANCES WILL RETURN TO OUR AREA BY
MONDAY EVENING AS ISENTROPIC LIFT BEGINS AHEAD OF THIS APPROACHING
UPPER LOW. THIS SYSTEM WILL MOVE THROUGH NORTH TEXAS TUESDAY NIGHT
ALLOWING COLDER AIR TO MOVE INTO THE STATE FOR WEDNESDAY. DRIER
AND COOLER WEATHER WILL PERSIST THROUGH THE LATTER HALF OF THE
WEEK WITH HIGHS IN THE 60S AND LOWS IN THE 40S. MODEL SOLUTIONS
BEGIN TO DIVERGE LATE AS THE GFS BECOMES PROGRESSIVE AND ALLOWS
THE UPPER TROUGH TO EXIT TO THE EAST WHILE THE LATEST ECMWF RUN
HOLDS SOME ENERGY OFF TO THE WEST AND INITIATES ANOTHER ROUND OF
ISENTROPIC UPGLIDE FOR THE WEEKEND. FOR NOW WILL KEEP THE FORECAST
RELATIVELY DRY FOR SATURDAY AND WAIT FOR BETTER MODEL AGREEMENT
BEFORE ADJUSTING TO A COOLER AND WETTER FORECAST FOR NEXT WEEKEND.

.MARINE...
TIDES AROUND 1 TO 2 FEET ABOVE NORMAL TONIGHT SLOWLY
IMPROVING SUNDAY AND MONDAY THOUGH NORTHEASTERLY FLOW WILL
KEEP TIDES UP.

WINDS OVER THE COASTAL WATERS WILL BE INCREASING TONIGHT AND HAVE
CONTINUED THE SCEC. SEAS SHOULD BUILD TO 4 TO 7 FEET AND CONTINUE
THROUGH SUNDAY AFTERNOON THEN WITH WINDS DROPPING OFF EXPECT SEAS TO
SLOWER. NORTHEASTERLY FLOW INCREASE LATE SUNDAY NIGHT AND MONDAY
WILL SEAS BUILD BACK IN BUT ONLY TO 3 TO 5 FEET. EASTERLY FLOW AS
FRONT STALLS THEN SLOWLY LIFTS BACK NORTH AND MAY HAVE A WINDOW OF
12-30 HOURS FOR FOG BEFORE THE NEXT FRONT COMES COMES IN AFTER 6 PM
TUESDAY.

.AVIATION...
CIGS LOWERING OVER THE AREA AS EXPECTED BUT PERHAPS A LITTLE FASTER
THAN EXPECTED. ALSO SEEING SOME FOG NEAR GALVESTON AT 3SM. EXPECTING
SHOWERS TO DEVELOP THROUGHOUT THE NIGHT AFTER 05Z AND SPREAD EAST
THROUGH THE AREA. ISOLATED-SCATTERED THUNDERSTORMS POSSIBLE (SEE
ABOVE) WILL CONTINUE THE VCSH/VCTS AND TEMPOS FOR THE SAME WINDOW.

IAH SOUTHWARD MAY HAVE A STINT OF IFR-LOW MVFR CIGS/FOG MONDAY
MORNING THROUGH TUESDAY WITH THE STATIONARY FRONT.

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 63 74 49 65 50 / 60 70 20 30 30
HOUSTON (IAH) 64 76 57 69 53 / 40 60 20 30 30
GALVESTON (GLS) 64 71 60 68 58 / 20 50 30 30 30

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM CST SUNDAY FOR THE FOLLOWING
ZONES: MATAGORDA BAY...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM.

SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH LATE TONIGHT FOR THE
FOLLOWING ZONES: GALVESTON BAY.

SMALL CRAFT ADVISORY UNTIL NOON CST SUNDAY FOR THE FOLLOWING
ZONES: WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM.

SMALL CRAFT ADVISORY UNTIL NOON CST SUNDAY FOR THE FOLLOWING
ZONES: WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.

SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.

DISCUSSION...38
AVIATION/MARINE...45

AREA FORECAST DISCUSSION

NWS LUBBOCK TX

304 PM CST SAT FEB 9 2013

.SHORT TERM...
A BUSY AFTERNOON IS IN STORE FOR THE CWA... WITH BOTH HIGH WINDS IN THE
WEST AND THE POSSIBILITY FOR STORMS IN THE EAST. AS EXPECTED... A
POTENT TROUGH IS CURRENTLY ADVANCING ON WEST TEXAS... WITH A 500MB
KT MAX OF OVER 100KT CURRENTLY SITUATED OVER EASTERN NEW MEXICO.
HIGH CLOUDS HAVE CLEARED OVER MOST OF THE NW PORTION OF THE CWA AND
NEW MEXICO...ALLOWING FOR DEEP MIXING AND VERY STRONG WINDS ACROSS
MOST OF EASTERN NEW MEXICO. WINDS HAVE BEEN SLOW TO VEER IN WEST
TEXAS THIS AFTERNOON...ALLOWING DEWPOINTS TO CLIMB INTO THE UPPER
30S AND NEAR 40 ACROSS MOST OF THE CAPROCK AS OF 18Z. HOWEVER...
SURFACE OBS AND RADAR TRENDS ARE INDICATING THAT WINDS ARE FINALLY
BEGINNING TO VEER SLIGHTLY IN THE WEST... WHICH HAS RESULTED IN
RAPID DRYING AND INCREASING WIND SPEEDS JUST EAST OF THE TEXAS NEW
MEXICO BORDER. GIVEN THESE TRENDS... HAVE OPTED TO UPGRADE
PARMER...CASTRO AND BAILEY COUNTIES TO A HIGH WIND WARNING THROUGH
02Z. FIRE WEATHER CONCERNS ARE STILL MINIMAL... ESPECIALLY GIVEN
THE HIGHER THAN ANTICIPATED DEWPOINTS ACROSS THE WEST AND MOIST FUEL
CONDITIONS... HOWEVER ELEVATED FIRE WEATHER CONDITIONS AND SOME
RED FLAG MINUTES WILL BE PRESENT NEAR THE TX/NM BORDER THROUGH
THE EARLY EVENING WHERE THE AIR WILL BE DRIEST AND WINDS
STRONGEST.

FURTHER EAST... THE FORECAST STILL APPEARS TO BE LARGELY ON TRACK AS
MOISTURE CONTINUES TO RETURN ACROSS THE EAST. RADAR AND SURFACES
OBSERVATIONS INDICATE THE BEGINNINGS OF A DRYLINE FORMING JUST TO
THE EAST OF THE TX/NM STATE LINE...AND APPEARS TO BE SLOWLY
ADVANCING EAST. IN ADDITION... VISIBLE SATELLITE IMAGERY IS SHOWING
AN INCREASE IN CUMULIFORM CLOUDS JUST TO THE DRY SIDE OF THIS
DEVELOPING DRYLINE. DEWPOINTS AS OF 20Z HAVE REACHED THE UPPER 40S
ACROSS THE SOUTHEAST...TO NEAR 40 IN THE NORTHERN ROLLING
PLAINS...WHICH IS A BIT LOWER THAN YOU WOULD LIKE FOR STORM
DEVELOPMENT. AS SUCH... INSTABILITY IS STILL VERY WEAK ACROSS THE
AREA...WITH MAXIMUM VALUES OF NEAR 500 J/KG RESTRICTED TO THE
SOUTHEAST. THERE STILL REMAINS SOME TIME FOR MOISTURE TO
INCREASE...AND IT STILL SEEMS WITHIN REASON THAT DEWPOINTS WILL
REACH THE UPPER 40S TO LOW 50S WITHIN THE NEXT FEW HOURS. LOCAL
HIGH RESOLUTION MODELS...INCLUDING THE TTUWRF AND TO A LESSER EXTENT
THE HRRR... SEEM TO BE SUGGESTING THAT INITIATION MAY HOLD OFF UNTIL
00Z... HOWEVER THE RUC IS STILL FIRING AROUND 22Z. GIVEN CURRENT
TRENDS... IT SEEMS THAT THE LATER INITIATION SOLUTIONS SEEM MORE
PLAUSIBLE. GIVEN THE VERY STRONGLY SHEARED WIND FIELDS... ANY
STORMS THAT CAN MANAGE TO INITIATE EARLY WILL VERY LIKELY BE
SUPERCELLULAR... AND COULD POSE A VERY ISOLATED TORNADO THREAT IF
MOISTURE CAN CONTINUE TO RISE. HOWEVER...THIS THREAT APPEARS TO BE
VERY MARGINAL AT THIS TIME... AND A MORE LIKELY THREAT WILL BE
MARGINALLY SEVERE HAIL TO 1" AND DAMAGING WINDS TO 70 MPH. THE MOST
LIKELY AREA FOR INITIATION STILL APPEARS TO BE NORTH OF LBB AND
EASTWARD TOWARDS THE CHILDRESS AREA. LATER IN THE EVENING...A
PACIFIC FRONT WILL SWEEP THROUGH THE AREA...AND LIKELY INITIATE
MORE STORMS WITH A MORE LINEAR MODE. STORMS WILL LIKELY EXIT THE
AREA TO THE EAST BY 06Z.

FOR TOMORROW...BREEZY WESTERLY WINDS BETWEEN 20-30 MPH WILL PERSIST
ACROSS THE AREA DURING THE AFTERNOON...WHICH WHEN COMBINED WITH LOW DEWPOINTS
WILL RESULT IN ELEVATED FIRE WEATHER CONDITIONS....ESPECIALLY ACROSS
THE ROLLING PLAINS WHERE WARMER TEMPERATURES WILL RESULT IN LOWER RH
VALUES...

.LONG TERM...
BY SUNDAY EVENING...FLOW ACROSS THE REGION WILL BE ZONAL TO SLIGHTLY
WEST SOUTHWESTERLY AS TODAY/S WIND MAKER EJECTS INTO THE GREAT
LAKES. TROUGH OUT WEST CONTINUES TO DEEPEN AND APPROACH LATE MONDAY
NIGHT. FLOW BECOMES NORTHWESTERLY BY WEDNESDAY WITH AN EMBEDDED
TROUGH DUE IN ON THURSDAY AND ANOTHER TROUGH DIGGING INTO THE
SOUTHWEST BY FRIDAY THOUGH MORE LATITUDINALLY ORIENTED THAN THE
EARLY WEEK SYSTEM. RIDGING BUILDS OUT WEST WITH STRONG NNW FLOW
WITH DECENT COLD AIR ADVECTION.

COLD FRONT SHOULD FINALLY MAKE IT INTO THE AREA SUNDAY EVENING WITH
WINDS BECOMING MORE OR LESS EASTERLY AND REMAINING IN FAVORABLE
UPSLOPE REGIME FOR MOISTURE ADVECTION. NAM/GFS/ECM HAVE COME INTO
GOOD AGREEMENT WITH SOME FAIRLY SUBSTANTIVE MOISTURE ADVECTION
MONDAY EVENING PERHAPS MAKING IT A BIT FURTHER WEST THAN EARLIER
THOUGHT. NEVERTHELESS...GENERAL TRENDS IN THE FORECAST REMAIN
INSOFAR AS MOISTURE GOES...BUT...WITH THE GREATER
MOISTURE...PRECIPITATION PHASE IS A BIT LESS CERTAIN WITH PHASE
REMAINING LIQUID UNTIL WRAP AROUND ON THE BACK SIDE OF THE
LOW...WITH LOWER TEMPS. GIVEN THIS FAIRLY RADICAL CHANGE THIS
RUN...WILL HOLD OFF ON MAKING MAJOR CHANGES TO ONGOING FORECAST FOR
NOW.

INTO WEDNESDAY...DRIER AIR WILL CONTINUE TO FILTER INTO THE REGION
AND START A WARMING TREND AFTER BOTTOMING OUT ON TUESDAY. THOUGH
WINDS BACK TO SOUTHWESTERLY ON WEDNESDAY...COLD FRONT IN WEDNESDAY
NIGHT/THURSDAY MORNING WILL USHER IN BREEZY NORTHERLY WINDS ONCE
AGAIN WITH YET COOLER AIR SURGING SOUTHWARD INTO FRIDAY WITH DRY
WEATHER TO PREVAIL.

.PRELIMINARY POINT TEMPS/POPS...
FRIONA 25 53 20 50 24 / 0 0 0 10 40
TULIA 28 57 26 51 26 / 20 0 0 10 40
PLAINVIEW 29 58 24 54 26 / 20 0 0 0 40
LEVELLAND 29 59 24 57 24 / 0 0 0 0 20
LUBBOCK 31 59 24 57 27 / 20 0 0 0 20
DENVER CITY 25 59 29 58 30 / 0 0 0 0 20
BROWNFIELD 29 60 24 59 28 / 10 0 0 0 20
CHILDRESS 36 65 26 56 27 / 60 0 0 0 40
SPUR 36 64 29 59 31 / 40 0 0 0 20
ASPERMONT 40 66 30 62 36 / 50 0 0 0 20

.LUB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 8 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ023-028-029-033>035-039-040.

HIGH WIND WARNING UNTIL 8 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021-022-027.

16/26

AREA FORECAST DISCUSSION

NWS LUBBOCK TX

1143 AM CST SAT FEB 9 2013

.UPDATE...
CONVECTIVE FORECAST APPEARS LARGELY ON TRACK FOR THIS AFTERNOON.
WHILE DEWPOINTS ACROSS THE ROLLING PLAINS ARE STILL SOMEWHAT LOW...
IN THE UPPER 30S FOR THE MOST PART... MOISTURE HAS BEEN RAPIDLY
INCREASING THROUGHOUT THE MORNING. LOW LEVEL WINDS ARE ON THE RISE
AS WELL...MOST IMPORTANTLY UPSTREAM OF THE CWA WHERE DEWPOINTS IN
CENTRAL TEXAS ARE CURRENTLY IN THE UPPER 40S TO NEAR 50S. IN
ADDITION...LATEST RUC GUIDANCE INDICATES SLIGHTLY MORE SUBSTANTIAL
MOISTURE RETURN THAN IN PREVIOUS RUNS...BRINGING LOW 50S DEWPOINTS
TO THE ROLLING PLAINS BY 21/22Z. THIS IS RESULTING IN MORE
BULLISH INSTABILITY PROGS... WITH MLCAPE VALUES APPROACHING 1000
J/KG BETWEEN 21 AND 03Z. FURTHERMORE... MODEL QPF FIELDS ARE
TRENDING TOWARDS SLIGHTLY EARLIER INITIATION...MOSTLY BETWEEN LBB
AND THE SOUTHERN PANHANDLE. INITIATION THIS EARLY WOULD VERY LIKELY
RESULT IN SUPERCELLS GIVEN THE STRENGTH AND NATURE OF AMBIENT WIND
FIELDS... INCLUDING BULK SHEAR VECTORS ALIGNED NEARLY PERPENDICULAR
TO THE INITIATING BOUNDARY. FURTHER SOUTHEAST...A STRONGER CAP WILL
LIKELY PROHIBIT INITIATION FROM OCCURRING UNTIL THE PACIFIC FRONT
SWEEPS THROUGH THE AREA AFTER 00Z. THUS... EXTENDED POPS A BIT
TO THE WEST IN THE NORTHERN PORTION OF THE CWA TO BETTER REFLECT
ANTICIPATED EARLIER INITIATION... AND LIKEWISE LOWER POPS IN THE
SOUTHEAST EARLIER IN THE AFTERNOON

.AVIATION..
VERY DIFFERENT SCENARIOS AT EACH TERMINAL TODAY. AT LBB...WINDS
WILL PICK UP DURING THE AFTERNOON...RESULTING IN SOME PATCHY
BLOWING DUST. AT CDS...THUNDERSTORMS ARE EXPECTED TO DEVELOP TO
THE WEST OF THE TERMINAL AND MOVE EAST BETWEEN 23-02Z... AND
POSSIBLY LATER. VFR CONDITIONS WILL PREVAIL AFTER 05Z AT CDS.

.PREV DISCUSSION... /ISSUED 549 AM CST SAT FEB 9 2013/

AVIATION...
TODAY WILL NOT BE A PLEASANT FLYING DAY IN THE VICINITY OF KLBB.
STRONG WINDS NEAR 45KT OUT OF THE SOUTH WERE OBSERVED JUST OFF
THE DECK NEAR KLBB. LATE THIS MORNING SURFACE WINDS WILL GREATLY
INCREASE OUT OF THE SOUTHWEST AT BOTH TAF SITES BUT ESPECIALLY
AT KLBB. SUSTAINED WINDS NEAR 30KT ARE POSSIBLE WITH LIGHT
VISIBILITY RESTRICTIONS DUE TO BLOWING DUST. A DRYLINE WILL BE
LOCATED BETWEEN KLBB AND KCDS WHICH WILL CREATE A CHANCE OF
THUNDERSTORMS NEAR KCDS EARLY IN THE EVENING. AS THIS POWERFUL
STORM SYSTEM MOVES JUST NORTH OF THE AREA...A FRONT WILL SWEEP
INTO THE REGION SHIFTING WINDS TO THE WEST AT BOTH TAF SITES THIS
EVENING. WINDS WILL STILL REMAIN BREEZY THROUGHOUT THE NIGHT.

PREV DISCUSSION... /ISSUED 453 AM CST SAT FEB 9 2013/

SHORT TERM...
TODAYS FORECAST IS QUITE A DOOZY. LOW LEVEL MOISTURE WAS MUCH SLOWER
TO MAKE ITS WAY BACK TO THE REGION THIS MORNING DESPITE
SOUTHEASTERLY UPSLOPE LOW LEVEL WINDS. HIGH CLOUDS THIS MORNING ARE
EXPECTED TO SWEEP OFF TO THE EAST WITH PERHAPS SOME STILL LINGERING
OVER THE ROLLING PLAINS BY THIS AFTERNOON. THERE SHOULD NOT BE AS
MUCH INHIBITING OF DEEP MIXING THIS AFTERNOON WITH THE LACK OF CLOUD
COVER. RAPID SURFACE CYCLOGENESIS IN LEE OF THE ROCKIES WILL DEVELOP
IN RESPONSE TO AN APPROACHING STORM SYSTEM TO AFFECT A LARGE PORTION
OF THE COUNTRY. MODELS HAVE BEEN CONSISTENT IN DEPICTING A 100KT
MAXIMUM AT 500HPA FROM EAST CENTRAL NEW MEXICO THROUGH THE WESTERN
TEXAS PANHANDLE. A BROAD AREA OF 40-50KT WINDS WILL ENCOMPASS MUCH
OF THE REGION AROUND 700HPA. A LOW LEVEL JET CURRENTLY OVER THE AREA
WILL LEAD TO QUICK MIXING OF STRONG WINDS DOWN TO THE SURFACE AFTER
SUNRISE. THE STRONG UPPER LEVEL JET MAXIMA WILL NOT COME ACROSS
UNTIL LATE TONIGHT INTO SUNDAY. SOLID ADVISORY LEVEL WINDS CAN BE
EXPECTED FOR MOST AREAS ON THE CAPROCK ALONG WITH VISIBILITY
RESTRICTIONS DUE TO BLOWING DUST. A PACIFIC FRONT WILL COME SWEEPING
THROUGH THE AREA THIS EVENING BRINGING MUCH DRIER AND COOLER AIR.

EARLY THIS MORNING...A WEAK SHORTWAVE WAS MOVING NORTHEAST THROUGH
THE FLOW OVER THE ROLLING PLAINS. THIS WAS GENERATING SOME MID LEVEL
CLOUDS AND RADAR RETURNS. HOWEVER...GIVEN THE VERY DRY LOW
LEVELS...DO NOT THINK MUCH WILL BE ABLE TO REACH THE GROUND.

THIS DAY WOULD NOT BE COMPLETE WITHOUT A THREAT FOR SEVERE WEATHER
WHICH WILL MAKE IT FEEL LIKE A NORMAL WEST TEXAS SPRING DAY. STORM
DEVELOPMENT CAN BE EXPECTED LATE IN THE DAY WITH HIGHEST CHANCES
OVER THE ROLLING PLAINS. MAXIMUM HEIGHT FALLS WILL BE NORTH OF THE
REGION ACROSS THE CENTRAL PLAINS. HOWEVER...STRONG FRONTOGENETICAL
FORCING WILL ENTER THE REGION AS THE PACIFIC FRONT SWEEPS THROUGH
THE AREA THIS EVENING. A LOW LEVEL JET WILL AGAIN FORM OUT AHEAD OF
THE FRONT THIS EVENING ADDING TO THE LOW LEVEL LIFT. THERE WILL BE
MODEST INSTABILITIES OF 500-1000 J/KG AS THE SURFACE DEW POINT
SURGES TO AROUND 50 DEGREES OFF THE CAPROCK. INITIALLY...CONVECTION
WILL BE CAPPED AT THE SURFACE AND MAY ONLY SEE A BRIEF PERIOD OF AN
UNCAPPED ENVIRONMENT CLOSE TO 23Z. AS STRONGER LOW LEVEL LIFT MOVES
INTO THE AREA STORMS MAY BE ABLE TO BLOSSOM NEAR SUNSET. STORMS WILL
ALSO BE TRANSITIONING FROM SURFACE BASED TO ELEVATED. REGARDING THE
TYPE OF SEVERE THREAT...SUPERCELLS ARE EXPECTED WITH VERY STRONG
SHEAR. THERE IS GOOD CLOCKWISE LOW LEVEL TURNING IN THE HODOGRAPHS
BUT ADDITIONAL INSTABILITY AND A LONGER PERIOD OF SURFACE BASED
STORMS WOULD BE DESIRABLE FOR MORE OF A TORNADO THREAT. HELICITY
VALUES ARE THEREFORE VERY IMPRESSIVE OVER THE ROLLING PLAINS.
OTHERWISE...HAIL AND DAMAGING WINDS CAN BE ANTICIPATED OUT OF STORMS
THAT DEVELOP. A STRONG WIND GUST MAY BE MORE LIKELY GIVEN THE VERY
STRONG WINDS THAT WILL OCCUR TODAY. STORMS THAT DO DEVELOP THIS
AFTERNOON AND EVENING WILL LIKELY BE HAULING LIKE A MACK TRUCK. JDV

LONG TERM...
HEIGHT GRADIENT AND WIND FIELDS WILL REMAIN FAIRLY TIGHT ACROSS
THE TEXAS SOUTH PLAINS SUNDAY AS THE UPPER LOW DEEPENS HEADING
INTO THE NORTHERN MISSISSIPPI VALLEY AND A TRAILING DISTURBANCE
DROPS SOUTHWARD INTO THE 4-CORNERS. SUNDAY EXPECTED TO BE COOLER
BEHIND THE PACIFIC COLD FRONT...THOUGH THIS MAY BE SOMEWHAT OFFSET
BY THE DOWNSLOPE WIND COMPONENT...ESPECIALLY OVER THE ROLLING
PLAINS. WINDS SHOULD DIMINISH SOMEWHAT HEADING INTO THE
AFTERNOON...THOUGH APPEAR STRONG ENOUGH TO SUPPORT A MENTION OF
AT LEAST PATCHY BLOWING DUST ON THE CAP-ROCK.

FLOW SHOULD BACK INTO MONDAY AS UPPER TROUGH SWINGS THROUGH THE
SOUTHERN ROCKIES AND DEEPENS VERY SLIGHTLY. A SHALLOW COLD AIRMASS
WILL ATTEMPT TO DROP INTO THE AREA EARLY MONDAY BUT WILL BE UP
AGAINST RENEWED LEE-SIDE CYCLOGENESIS OVER THE SOUTHWESTERN PART
OF THE TEXAS SOUTH PLAINS. A FAIRLY STRONG SOUTH TO NORTH TEMPERATURE
GRADIENT SHOULD SET UP...LOW LEVEL FLOW WILL EVENTUALLY BACK MORE
TO THE EAST LATE ON MONDAY ALTHOUGH MOISTURE RETURN INITIALLY WILL
BE LITTLE OR NONE.

THE UPPER TROUGH IS EXPECTED TO PROGRESS EASTWARD ACROSS THE
EXTREME SOUTHERN PART OF THE TEXAS PANHANDLE EARLY TUESDAY...
FILLING SLIGHTLY ALONG THE WAY. WE ARE EXPECTING ONLY A MODEST LOW
LEVEL MOISTURE RETURN THOUGH THIS WILL TEND TO POOL ALONG A
FRONTOGENETIC ZONE ACROSS THE SOUTHERN PANHANDLE. THE AIRMASS WILL
COOL QUICKLY AS THE UPPER TROUGH SWINGS OVERHEAD...AND ANY SHOWERS
SHOULD TEND TO FAVOR SNOW PHASE ON THE CAPROCK...AND EVEN PERHAPS
A MIXTURE FOR THE ROLLING PLAINS. BUT PRECIPITATION TOTALS
CURRENTLY DO NOT SUPPORT CONSIDERATION OF ANY TYPE OF WINTER
WEATHER WATCH OR ADVISORY.

WEAKENING NORTHWEST FLOW WEDNESDAY WILL BE FOLLOWED BY BACKING
FLOW AGAIN AS ANOTHER DISTURBANCE DIGS SOUTHWARD OUT OF WESTERN
CANADA THURSDAY AND FRIDAY. MODEL DISPARITY INCREASES QUITE A BIT
BY THIS TIME SO CONFIDENCE ON AMPLITUDE OF ANY WAVES LATE NEXT
WEEK IS LOW. SOME DISCREPANCY AS WELL WITH ARRIVAL OF NEXT
CANADIAN COLD FRONT BETWEEN EARLY AND LATE THURSDAY. WE USED A
BLEND OF ECMWF AND GFS SOLUTIONS FOR THIS PERIOD WHICH WAS STILL
REASONABLY CLOSE TO THE PREVIOUS FORECAST. FRIDAY WOULD SEE THE
COLDEST DAY OF THE COMING WEEK IF THESE TRENDS PAN OUT. RMCQUEEN

FIRE WEATHER...
THE WILDFIRE THREAT MAY NOT HAVE BEEN AS INTENSE AS PREVIOUSLY
THOUGHT. NEAR SURFACE MOISTURE IS STILL EXPECTED TO INCREASE THIS
MORNING WHICH WILL RESULT IN HIGHER RELATIVE HUMIDITY VALUES THIS
AFTERNOON. AS TEMPERATURES INCREASE...AFTERNOON RELATIVE HUMIDITY
VALUES WILL DROP TO RIGHT AROUND 15 PERCENT IN THE SOUTHWESTERN
TEXAS PANHANDLE WITH HIGHER VALUES ELSEWHERE. WINDS ARE EXPECTED TO
BE VERY STRONG WITH A RAPIDLY DEVELOPING STORM SYSTEM OVER THE
ROCKIES. WHAT REMAINS OF HIGH UNCERTAINTY IS THE EFFECT OF A LOW
LEVEL THERMAL RIDGE. THIS THERMAL RIDGE WILL HAVE ITS AXIS CENTERED
OVER THE WESTERN SOUTH PLAINS UP THROUGH THE WESTERN TEXAS
PANHANDLE. THE 500MB WINDS WILL BE SLIGHTLY OUT OF POSITION BUT DO
HAVE SOME OVERLAP NEAR THE WESTERN SOUTH PLAINS. THIS WILL BE THE
FIRST TIME THIS SEASON WE WILL SEE THE MAXIMUM MID LEVEL WINDS NEAR
THE LOW LEVEL THERMAL RIDGE. THE DROUGHT HAS ALSO BEEN THE WORST IN
THE WESTERN SOUTH PLAINS THROUGH THE SOUTHWESTERN TEXAS PANHANDLE.
HOWEVER...FUELS ARE STILL NEAR NORMAL MOISTURE LEVELS AND WILL
CANCEL THE FIRE WEATHER WATCH BECAUSE OF THIS.

SUNDAY WILL SEE A MODERATELY WINDY DAY WITH DRY WESTERLY DOWNSLOPE
WINDS. COOLER TEMPERATURES SHOULD KEEP THE AFTERNOON RELATIVE
HUMIDITY JUST ABOVE 15 PERCENT ON THE CAPROCK...BUT THE ENHANCED
DOWNSLOPE FLOW OVER THE SOUTHERN PART OF THE ROLLING PLAINS IN
PARTICULAR MIGHT BRING ON LOCALLY CRITICAL CONDITIONS. FUELS IN
THIS AREA...HOWEVER...STILL APPEAR FAIRLY NON-RESPONSIVE WITH ONLY
MODEST ERC LEVELS AND ALSO KEETCH-BYRAM INDICES NEAR NORMAL
RANGES. WOULD THUS LIKELY FAVOR MORE AN ENHANCED FIRE WEATHER
THREAT ON SUNDAY THAN A CRITICAL AREA.

MONDAY ALSO OFFERS AT LEAST A MENTION FOR AN ENHANCED THREAT OF
FIRE WEATHER CONDITIONS OVER THE SOUTHWESTERN SOUTH PLAINS WITH A
WEAK LOW LEVEL THERMAL RIDGE AND TIGHT ENOUGH SURFACE GRADIENT FOR
MODERATE SOUTHWEST BREEZES. RMCQUEEN

.PRELIMINARY POINT TEMPS/POPS...
FRIONA 24 55 19 49 21 / 0 0 0 10 40
TULIA 25 57 22 48 24 / 20 0 0 10 40
PLAINVIEW 28 57 22 51 25 / 20 0 0 0 40
LEVELLAND 28 57 22 57 25 / 0 0 0 0 20
LUBBOCK 29 58 22 56 26 / 20 0 0 0 20
DENVER CITY 28 57 24 58 26 / 0 0 0 0 20
BROWNFIELD 29 58 24 57 26 / 10 0 0 0 20
CHILDRESS 36 63 25 52 28 / 60 0 0 0 40
SPUR 34 61 25 56 28 / 40 0 0 0 20
ASPERMONT 41 65 27 60 30 / 50 0 0 0 20

.LUB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 8 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021>023-027>029-033>035-039-040.

16/99/99

AREA FORECAST DISCUSSION...UPDATED

NWS FORT WORTH TX

1137 AM CST SAT FEB 9 2013

.AVIATION...
CONCERNS...STRONG TO SEVERE CONVECTION LATE TONIGHT AND TRANSITION
OF MVFR TO IFR THIS EVENING.

WARM...MOIST ADVECTION IS IN PROGRESS NOW AND WILL CONTINUE
THROUGH LATE TONIGHT. CEILINGS WILL REMAIN MVFR THIS AFTERNOON
THEN GO IFR THIS EVENING THROUGH LATE TONIGHT AHEAD OF
AN APPROACHING PACIFIC FRONT/DRYLINE. WE COULD SEE AN HOUR OR TWO
OF CEILINGS ABOVE 3000 FEET LATE THIS AFTERNOON...BUT THIS WILL BE
SHORT LIVED. WILL INCLUDE VCSH FOR THE SOME OF THE EVENING HOURS
AND SOME OF THIS ACTIVITY MAY PASS ACROSS THE AIRPORTS WITH
VISIBILITIES FALLING TO IFR DURING THE EVENT.

CONVECTION WILL BE DEVELOPING WEST OF THE REGION ALONG THE COLD FRONT
THIS EVENING AND WILL PUSH RAPIDLY THROUGH KFTW/KAFW AROUND 10Z
AND KDFW...KDAL AND KACT 10 TO 11Z. SEVERE THUNDERSTORMS ARE
POSSIBLE WITH LARGE HAIL AND DAMAGING STRAIGHT LINE WINDS POSSIBLY
AFFECTING ANY OF OUR TAF SITES BETWEEN 10-12Z.

WINDS WILL BE SOUTHERLY AND GUSTY THIS AFTERNOON THEN 10-15KTS
OVERNIGHT. AFTER THE COLD FRONT PASSES...CEILINGS WILL LIFT TO VFR
AND WINDS WILL VEER WESTERLY AND INCREASE TO 15-20KTS. 75

.UPDATE...
WIDELY SCATTERED SHOWERS HAD DEVELOPED THIS MORNING ACROSS PARTS
OF NORTH TEXAS...WITH MOST OF THE ACTIVITY CONCENTRATED IN AREAS
NORTH THROUGH NORTHEAST OF DFW METROPLEX. WILL CONTINUE WITH
SLIGHT CHANCES OF SHOWERS AREA WIDE THIS AFTERNOON AS WARM/MOIST
ADVECTION INTENSIFIES.

WARM FRONT WAS BECOMING BETTER DEFINED FROM SOUTH OF LUBBOCK TO
NEAR HOUSTON AT MID MORNING. THIS WARM FRONT WILL CONTINUE TO
MOVE/DEVELOP NORTHWARD TODAY...AND ACCELERATE NORTHWARD INTO
OKLAHOMA LATE TONIGHT AS LOW LEVEL SOUTHERLY WINDS INCREASE.
TEMPERATURES THIS AFTERNOON WILL CONTINUE TO SLOWLY RISE IN SPITE
OF WIDESPREAD CLOUD COVER AS WARM FRONT LIFTS THROUGH THE AREA.
TEMPERATURES LIKELY TO HOLD STEADY OR EVEN CONTINUE TO SLOWLY RISE
INTO THE EVENING HOURS AS LOW LEVEL WARM/MOIST ADVECTION
CONTINUES.

STRONG UPPER SYSTEM CENTERED OVER ARIZONA THIS MORNING WILL MOVE
EAST AND THEN NORTHEAST OUT OF THE SOUTHERN ROCKIES TONIGHT. A
PACIFIC FRONT WILL OVERTAKE THE DEVELOPING DRYLINE ACROSS WESTERN
TEXAS TONIGHT...AND THEN ACCELERATE EASTWARD TONIGHT. THE PACIFIC
COLD FRONT IS EXPECTED TO BE THE PRIMARY FOCUS FOR THE WIDESPREAD
SHOWER AND THUNDERSTORM DEVELOPMENT ACROSS NORTH TEXAS LATER
TONIGHT. CURRENT TRENDS OBSERVED ON LATEST ANALYSES MATCH WELL
WITH THE EXPECTED EVOLUTION OF CONVECTION FOR LATER TONIGHT.
STRONG TO SEVERE STORMS...WITH A POTENTIAL FOR DAMAGING WINDS AND
LARGE HAIL...REMAIN IN THE FORECAST FOR LATE TONIGHT AND EARLY
SUNDAY MORNING. 09/GP

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

75/

AREA FORECAST DISCUSSION...UPDATED

NWS FORT WORTH TX

1105 AM CST SAT FEB 9 2013

09/GP

.AVIATION...
/12Z TAFS/

CONCERNS...MVFR CEILINGS THIS MORNING...STORMS TONIGHT.

TR.92

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

/09

AREA FORECAST DISCUSSION

NWS SPOKANE WA

1017 AM PST Sat Feb 9 2013

.SYNOPSIS...
Dry and stable weather is on tap for the weekend. Some light snow
will be possible over the Idaho Panhandle mountains today and
tonight, but the remainder of the Inland Northwest will have a
good chance of experiencing some sunshine. The next storm system
is expected to arrive on Tuesday bringing an increased potential
for rain and mountain snow.

.DISCUSSION...
Update: a frontal wave continues to track into the Canadian
Prairies this morning, with the supporting mid-level shortwave
diving through Alberta and southeast British Columbia. WV/IR
imagery showed the center of latter feature working through
Edmonton, Alberta. A jet streak and mid-level diffluence on its
west-southwest side was nosing into the Inland Northwest, leading
to a modest higher level cloud deck. Meanwhile low level moisture
and an inversion topped between 3500-4000 feet MSL is holding low
clouds and fog in place across northeast Washington and a large
portion of the Panhandle. Satellite extrapolation of the higher
cloud deck and model guidance supports this feature dissipating
from the north through the mid to later afternoon. As for the low
clouds and fog, the 12Z KOTX sounding well. The RUC13 is closest.
Overall this is expected to be slow. I increased the stratus and
continued the fog through the afternoon, though allow it to be
patchier and indicated shrinking coverage. Locally dense fog was
noted on area webcams and by spotter reports toward the West
Plains into Lincoln county. Will continue to handle with NOWCASTs.

As for precipitation, the threat of light snow showers will continue
to spread into the Panhandle and southeast zones, including the
Blues through Camas Prairie, with the previously described
shortwave disturbance coming in. The ongoing forecast in this
respect looks reasonable. Temperatures are also on track. /J. Cote`

.AVIATION...
18Z: Areas of IFR low clouds will impact portions of KGEG-KCOE and
in the vcnty of KPUW, with patchy fog, before some MVFR/VFR
conditions briefly develop. Low level inversions, stronger than
most guidance, will help to keep these conditions in place.
Confidence on how fully things break up and durations are small,
but a brief period is projected, before conditions degrade after
dark again. The KLWS is expected to be mainly VFR, but brief MVFR
conditions are possible. A mid-level shortwave passing by will
bring a threat of light snow showers to the central Panhandle
through the Camas Prairie, a few of which may slip near KCOE and
possibly KPUW/KLWS this afternoon and evening. Western TAFs are
expected to be mainly dry and VFR. /J. Cote`

.PRELIMINARY POINT TEMPS/POPS...
Spokane 35 21 36 23 35 29 / 0 0 0 0 10 20
Coeur d`Alene 35 21 36 23 35 30 / 10 0 0 0 10 20
Pullman 35 24 38 25 39 31 / 10 10 0 0 0 20
Lewiston 42 29 43 29 43 35 / 10 10 0 0 0 10
Colville 41 24 40 22 38 30 / 0 0 0 0 10 20
Sandpoint 36 24 36 26 35 30 / 10 10 0 0 10 30
Kellogg 35 24 37 27 39 30 / 20 20 10 10 10 30
Moses Lake 43 25 42 24 41 29 / 0 0 0 0 0 0
Wenatchee 43 26 42 25 40 29 / 0 0 0 0 0 0
Omak 36 21 37 20 35 24 / 0 0 0 0 0 10

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

AREA FORECAST DISCUSSION...UPDATED

NWS MILWAUKEE/SULLIVAN WI

1012 AM CST SAT FEB 9 2013

.UPDATE...VISIBILITIES CONTINUE TO IMPROVE THIS MORNING...SO
ALLOWED THE FREEZING FOG ADVISORY TO EXPIRE. MAIN ISSUE FOR THE
REMAINDER OF THE DAY IS HOW LONG THIS LOW LEVEL CLOUD DECK WILL
STICK AROUND. LATEST RAP AND NAM SOUNDINGS INDICATED THESE CLOUDS
MAY NOT GO AWAY FOR A WHILE...THE NAM NOT SHOWING CLEARING SKIES
AT MADISON UNTIL TUESDAY AFTERNOON. WILL CONSIDER INCREASING
CLOUDS...AND CONSEQUENTLY LOWERING HIGH TEMPS A TAD IF THIS CLOUD
DECK SHOWS NO SIGNS OF ERODING.

.AVIATION/18Z TAFS/...VISIBILITIES CONTINUE TO IMPROVE THIS
MORNING...WITH THE REMAINING CONCERN TODAY BEING HOW LONG THIS LOW
LEVEL CLOUD DECK WILL STICK AROUND. LATEST RAP AND NAM SOUNDINGS
INDICATED THESE CLOUDS MAY HANG AROUND THROUGH THE REMAINDER OF
THE DAY. WILL ASSESS NEW MODEL DATA AND MONITOR OBS...CONSIDERING
EXTENDING LOW CIGS IN THE TAFS FOR A WHILE LONGER.

PRECIPITATION WILL MOVE IN FROM THE SOUTHWEST VERY LATE TONIGHT
INTO SUNDAY MORNING. GOOD CHANCE FOR A PERIOD OF FREEZING
RAIN...ESPECIALLY ALONG AND SOUTHWEST OF A WISCONSIN DELLS TO
MILWAUKEE LINE WHERE TEMPERATURES WILL BE COLDER WHEN THE RAIN
INITIALLY ARRIVES. MAY CAUSE PROBLEMS FOR A SHORT WHILE...THOUGH
TEMPERATURES WILL WARM THROUGH THE DAY...WITH ALL RAIN EXPECTED BY
LATE MORNING OR EARLY AFTERNOON.

LOWER CIGS AND VSBYS LIKELY BY SUNDAY AFTERNOON AS PRECIPITATION
AND HIGHER DEWPOINTS MOVE IN OVER SNOWPACK.

.PREV DISCUSSION... /ISSUED 346 AM CST SAT FEB 9 2013/

SHORT TERM...

TODAY AND TONIGHT-FORECAST CONFIDENCE MEDIUM TO HIGH

SURFACE HIGH PRESSURE OVER THE GREAT LAKES WILL MOVE OFF TO THE EAST
AS SOUTH WINDS INCREASE TODAY AND TONIGHT.

AREAS OF STRATUS AND PATCHY FOG WILL BE A CONCERN ESPECIALLY THIS
MORNING. ALSO LAKE CLOUDS MAY PUSH IN TO THE EAST AS LOW LEVEL
WINDS BECOME SOUTHEAST.

MID/UPPER LEVEL RIDGE BRIEFLY BUILDS OVER WISCONSIN TODAY. THEN THE
STRONG SHORTWAVE OVER THE SOUTHWEST U.S. MOVES ACROSS COLORADO THIS
AFTERNOON AND INTO CENTRAL NEBRASKA BY SUNRISE SUNDAY. 250 MB
DIVERGENCE INCREASES LATE TONIGHT ESPECIALLY OVER SOUTH CENTRAL
WISCONSIN. 850/700 MB WARM AIR ADVECTION BEGINS TODAY AND
TONIGHT...BUT 850 MB TEMPERATES COOL A LITTLE TOWARD SUNRISE DUE TO
EVAPORATIVE COOLING WITH THE DEVELOPING MID LEVEL SATURATION AND
UPWARD MOTION. 850/700 MB MOISTURE CONVERGENCE INCREASES LATE
TONIGHT.

SOME PRECIPITATION MAY REACH THE GROUND TOWARD SUNRISE...MAINLY IN
AREAS SOUTH AND WEST OF MADISON. PRECIPITATION TYPE WOULD BE A MIX
GIVEN THE WARMING ABOVE ZERO CELSIUS IN THE SOUTHWEST AROUND 1 TO 4
THSD FT. EVAPORATIVE COOLING COULD CAUSE ANY INITIAL PRECIPITATION
TO BE BRIEFLY SNOW...BEFORE FREEZING RAIN WOULD QUICKLY BECOME THE
MAIN PRECIPITATION TYPE SUNDAY MORNING. ANY PRECIPITATION LATE
TONIGHT WOULD BE LIGHT.

SUNDAY-FORECAST CONFIDENCE HIGH

DEEP LOW STILL SHOWN TO CROSS FROM NEBRASKA INTO NORTH CENTRAL
IOWA SUNDAY...AND THEN CLIP SOUTHEAST MINNESOTA ON ITS WAY TO
NORTHERN WISCONSIN SUNDAY NIGHT. MODELS PRETTY CONSISTENT ON
TIMING OF PRECIPITATION IN WARM ADVECTION REGIME SPREADING NORTH.
ONE DIFFERENCE IS THAT THERMAL PROFILES NO LONGER SUPPORT SLEET AT
THE ONSET...WITH WARM LAYER DEEPER AND AROUND +3C AND SURFACE COLD
LAYER SHALLOWER. NAM IS PRETTY AGGRESSIVE WITH QPF AND BUFKIT
SHOWS ABOUT 0.25" OF FREEZING RAIN AT MSN AND MKX. WENT WITH A
MORE CONSERVATIVE APPROACHING CLOSER TO GFS AND SREF SOLUTIONS
WHICH HAVE LESS THAN 0.10" OF ICE.

CONSIDERED A FREEZING RAIN ADVISORY FROM 12-17Z. IN COORDINATION
WITH NWS LA CROSSE AND TWIN CITIES WILL HOLD OFF ON ADVISORY UNTIL
LATER THIS MORNING SO THAT MPX CAN SHORE UP A COMPLICATED SET OF
HEADLINES. IT IS A MARGINAL EVENT AND THIS WOULD BE 3RD
PERIOD...SO STILL PLENTY OF TIME TO GET THE WORD OUT. WILL ISSUE
AN SPS TO RAMP THINGS UP.

OTHERWISE NICE SLUG OF RAIN ON ORDER OF 0.25 TO 0.50" ON TAP
WITHIN 50 KNOT 850 LOW LEVEL JET AXIS. DRY SLOT WORKS INTO AREA LATE
AFTERNOON AND EVENING WITH RAIN TAPERING TO DRIZZLE. GIVEN SNOW
COVER AND MODEST WINDS...AREAS OF FOG IN ORDER BUT NOT SURE ABOUT
HOW DENSE GIVEN WEAKER GRADIENT NEAR SURFACE LOW GOES WELL NORTH.

AS COLDER AIR WORKS IN AFTER MIDNIGHT...EXPECT DRIZZLE AND LIGHT
RAIN TO TURN OVER TO VERY LIGHT SNOW.

MONDAY-FORECAST CONFIDENCE HIGH

DEEP OCCLUDED LOW BEGINS TO FILL AS IT PULLS AWAY FROM WISCONSIN
AND CROSSES NORTHERN LAKE MICHIGAN AND LAKE HURON. CYCLONIC FLOW
WITH COLD WEST TO NORTHWEST FLOW AND STEEP LOW LEVEL LAPSE RATES
SUGGESTS WINDY CONDITIONS WITH GUSTS OF 30 TO 35 KNOTS. LOOKS
MARGINAL FOR WIND ADVISORY BUT GALE CONDITIONS POSSIBLE OVER LAKE
MICHIGAN.

BUFKIT SHOWING TOUCH OF CAPE IN BOUNDARY LAYER BUT DOES NOT QUITE
REACH THE DENDRITE ZONE. VERY LIGHT SNOW IN CYCLONIC WRAP AROUND
SEEMS LIKELY...BUT JUST A COUPLE HUNDREDTHS OF QPF SHOWN SO LESS
THAN AN INCH OF ANY ACCUMULATION OCCURS.

LONG TERM...

TUESDAY AND WEDNESDAY-FORECAST CONFIDENCE HIGH

DRY AND SEASONABLY COLD NORTHWEST FLOW SITUATION EXPECTED WITH
QUIET WEATHER RESULTING.

THURSDAY AND FRIDAY-FORECAST CONFIDENCE MEDIUM

ALTHOUGH THERE IS A TYPICAL AMOUNT OF DIFFERENCE IN THE GUIDANCE
AT DAY 6 AND 7...MODELS HAVE CONVERGENCED A BIT AND ECMWF REMAINS
PRETTY CONSISTENT AND BRINGING ANOTHER SNOW EVENT. ECMWF AND GEMNH
HAVE A CLIPPER LIKE SYSTEM DIGGING SOUTHEAST ACROSS THE NORTHERN
PLAINS AND THEN TURNING THE CORNER AROUND IOWA TO ILLINOIS. LOOKS
FAVORABLE FOR ACCUMULATING SNOW BUT GFS IS STILL MUCH WEAKER AND
DRIER WITH THIS SYSTEM...FOCUSING MORE ON DEVELOPMENT TOWARD THE
WEEKEND ALONG THE EAST COAST.

THIS CERTAINLY COULD TURN INTO AN ADVISORY TYPE SNOW EVENT AND
BUMPED UP POPS TO CHANCE GIVEN BETTER MODEL AGGREMENT.

AVIATION/12Z TAFS/...

SURFACE HIGH PRESSURE OVER THE GREAT LAKES WILL MOVE OFF TO THE EAST
AS SOUTH WINDS INCREASE TODAY AND TONIGHT.

AREAS OF IFR STRATUS AND PATCHY LIFR FOG WILL BE A CONCERN
ESPECIALLY THIS MORNING. ALSO MVFR LAKE CLOUDS MAY PUSH IN TO THE
EAST AS LOW LEVEL WINDS BECOME SOUTHEAST.

AS STRONG LOW PRESSURE EXITS COLORADO AND REACHES THE CENTRAL PLAINS
SOME PRECIPITATION MAY REACH THE GROUND TOWARD SUNRISE...MAINLY IN
AREAS SOUTH AND WEST OF MADISON. PRECIPITATION TYPE WOULD BE A MIX
GIVEN THE WARMING ABOVE ZERO CELSIUS IN THE SOUTHWEST AROUND 1 TO 4
THSD FT. EVAPORATIVE COOLING COULD CAUSE ANY INITIAL PRECIPITATION
TO BE BRIEFLY SNOW...BEFORE FREEZING RAIN WOULD QUICKLY BECOME THE
MAIN PRECIPITATION TYPE SUNDAY MORNING. ANY PRECIPITATION LATE
TONIGHT WOULD BE LIGHT.

MARINE...

SOUTHEAST WINDS MAY REACH SMALL CRAFT CRITERIA TONIGHT. SMALL CRAFT
ADVISORY CONDITIONS WILL BE LIKELY FOR SUNDAY AND MONDAY AS STRONG
LOW PRESSURE MOVES FROM THE CENTRAL PLAINS TO FAR NORTHWEST
WISCONSIN. SOME GALE WINDS WILL BE POSSIBLE MAINLY SUNDAY EVENING
AND MONDAY.

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST MONDAY
FOR LMZ643>646.

UPDATE...DDV
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
SUNDAY THROUGH FRIDAY...CRAVEN