Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/23/13

AREA FORECAST DISCUSSION

NWS DENVER/BOULDER CO

836 PM MDT MON APR 22 2013

.UPDATE...SNOW HAD BECOME MORE WIDESPREAD THIS EVENING ALTHOUGH
THE HEAVIEST SNOW WAS ANCHORED FROM THE MOUNTAINS AND FOOTHILLS
NORTH OF I-70 EASTWARD THROUGH BOULDER...SOUTHERN WELD...SOUTHERN
MORGAN...AND WASHINGTON COUNTIES. HAVE EXPANDED THE ADVISORIES
EAST TO ACCOUNT FOR THIS...AND ALSO UPGRADED THE WESTERN SUBURBS
TO A WARNING WHERE MANY ROADS WERE ALREADY BECOMING SNOWPACKED
AND HAZARDOUS WITH HEAVIER SNOW SHOWERS. WE WERE ALREADY
APPROACHING 5 INCHES IN BOULDER. THE UPPER LEVEL JET PER THE
LATEST RAP AND NAM BUCKLE SLIGHTLY NORTHWARD TIL 06Z AND CURRENT
WATER VAPOR LOOPS SUPPORTS THIS. HOWEVER...LATEST IR SHOWS
CONVECTIVE SNOW INCREASING QUITE RAPIDLY OVER THE ASPEN TO SUMMIT
COUNTY CORRIDOR...WHICH COULD SHIFT BAND SOUTHWARD TO DENVER.
POTENTIAL STILL EXISTS FOR HEAVY BANDED SNOW MOST AREAS.

AS DISCUSSED EARLIER...THIS STORM WILL LIKELY LINGER A FEW MORE
HOURS THAN EARLIER ANTICIPATED GIVEN THE WEAK DYNAMICS THAT
PERSIST INTO TUESDAY MORNING. SOME ADVISORIES ESPECIALLY THOSE
SOUTH OF INTERSTATE 70 MAY NEED TO BE EXTENDED A FEW HOURS. THE
TUESDAY MORNING COMMUTE LOOKS SLOW WITH SNOW COVERED ROADS AND
TEMPERATURES IN THE LOWER 20S. WHEREVER MODERATE TO HEAVY SNOW
WAS OCCURRING THIS EVENING THERE HAS ALREADY BEEN A REDUCTION IN
TRAVEL CONDITIONS WITH SNOW AND SLUSH DEVELOPING ON ROADS.

.AVIATION...ONLY CHANGE WAS TO ADD ANOTHER INCH OF SNOW EXPECTED
AT THE KDEN AND KBJC WITH 3-6 INCHES MORE LIKELY. KAPA MAY STILL
BE ON THE LOWER END GIVEN THEIR LATER START...BUT THEY COULD SEE
SNOW LINGER A COUPLE HOURS LONGER THERE TO HELP MAKE UP FOR LACK
THIS EVENING.

.PREV DISCUSSION... /ISSUED 628 PM MDT MON APR 22 2013/

UPDATE...SNOW BANDS/SHOWERS SEEM MORE WIDESPREAD BUT OF LESS
INTENSITY THAN LAST WEEKS SNOW. HOWEVER...THEY MAY HAVE A
TENDENCY TO HOLD ON A LITTLE LONGER GIVEN AT LEAST WEAK LIFT
CONTINUING INTO TUESDAY MORNING. LATEST RAP/GFS SUGGEST SNOW
SHOULD CONTINUE AT A DECENT CLIP THROUGH ABOUT 09Z AND THEN
GRADUALLY DECREASE THROUGH 15Z. THIS GIVES US ABOUT 3 MORE HOURS
OF SNOW SO A DECENT DURATION EVENT IS UNDERWAY. THIS COULD LEAD TO
AN INCH OR TWO MORE OF SNOW ACCUMULATION...SO MAY NUDGE SNOW
AMOUNTS UP SLIGHTLY AND HIGHLIGHTS MAY NEED TO BE EXTENDED TIL MID
MORNING TUESDAY. WILL CONTINUE TO MONITOR.

AVIATION...IFR/LIFR CONDITIONS WITH SNOW WILL CONTINUE THROUGH
ABOUT 15Z TUESDAY. HEAVIEST SNOW EXPECTED FROM NOW THROUGH ABOUT
09Z...THEN GRADUALLY DECREASING IN INTENSITY OVERNIGHT/EARLY
TUESDAY MORNING. COULD SEE VSBYS DROP TO 1/4 MILE WITH HEAVIER
SNOW SHOWERS TIL ABOUT 06Z...THEN 1/2SM TO 1SM MILE VSBYS SHOULD
PREVAIL. TAF UPDATES INCLUDE SOMEWHAT LOWER CONDITIONS TIL 15Z.
VFR EXPECTED BY 18Z-21Z TUESDAY.

PREV DISCUSSION... /ISSUED 302 PM MDT MON APR 22 2013/

SHORT TERM...NO SIGNIFICANT CHANGES AT THIS TIME. THE UPPER
LEVEL JETSTREAM IS PARKED OVER NORTHERN COLORADO AND SHOULD
GRADUALLY SHIFT SOUTH OVERNIGHT. MODERATE TO STRONG QG ASCENT OVER
SWRN WY/NWRN CO JUST AHEAD OF THE APPROACHING TROUGH AXIS...WILL
MOVE EAST ACROSS COLORADO TONIGHT INTO TUESDAY MORNING. ALONG THE
FRONT RANGE...RADAR INDICATING NELY UPSLOPE WINDS TO JUST BLO 700
MB AND THIS IS PROGGED TO CONTINUE THROUGH THIS EVENING. AS A
RESULT...ALL THE INGREDIENTS STILL THERE FOR PERIOD OF MODERATE TO
HEAVY SNOWFALL IN THE FRONT RANGE MOUNTAINS AND FOOTHILLS. AS FOR
THE URBAN CORRIDOR...SNOWFALL TOTALS OF 1 TO 2 INCHES RESULTED
WITH THE SHOWER BANDS THIS AFTERNOON...NOT MUCH IMPACT ON THE
ROADWAYS YET. SHOULD SEE SNOWFALL INCREASE COVERAGE AND INTENSITY
LATE THIS AFTN AND EVENING SO EVENING RUSH COULD BE IMPACTED IF
ROADWAYS BECOME SLUSHY WITH VSBYS LESS THAN ONE HALF MILE IN THE
HEAVIER SNOW BANDS. THIS SHOULD BE SUFFICIENT TO JUSTIFY THE
WINTER WEATHER ADVISORY. TREND FOR THE SNOWFALL TO DECREASE FM
NORTH TO SOUTH ACROSS THE CWFA TUESDAY MORNING. SHOULD BE DRY BUT
QUITE COOL TUESDAY AFTN.

LONG TERM...NORTHWEST FLOW ALOFT WILL PREVAIL TUESDAY NIGHT AND
WEDNESDAY. A WEAK DISTURBANCE EMBEDDED IN THE FLOW ALOFT MAY BRING
A FEW SHOWERS TO THE MOUNTAINS WEDNESDAY. IF ANYTHING DEVELOPS IT
WILL BE LIGHT. THE COLD AIR BROUGHT IN BY THE LATEST STORM SYSTEM
WILL SHIFT EAST OF THE AREA. HIGHS WILL CLIMB INTO THE UPPER 40S
TO LOWER 50S WEDNESDAY.

FLOW ALOFT WILL SHIFT WESTERLY AS A WEAK WAVE DIGS SOUTH ACROSS THE
GREAT BASIN. THIS WAVE WILL THEN EJECT EASTWARD AND BRING A CHANCE
FOR SHOWERS...MAINLY SOUTH OF INTERSTATE 70. AIRMASS WILL CONTINUE
TO WARM ON THURSDAY AND MOST AREAS OVER NORTHEAST COLORADO WILL
CLIMB ABOVE 60 DEGREES.

FOR FRIDAY AND THE WEEKEND...WILL SEE AN UPPER LEVEL RIDGE BUILD
OVER THE CENTRAL ROCKIES. THIS WILL BRING DRY AND MILD CONDITIONS.
TEMPERATURES WILL CLIMB WELL INTO THE 60S AND LIKELY SEE 70S BY
SUNDAY.

SOUTHWEST FLOW ALOFT WILL DEVELOP MONDAY AS THE RIDGE SHIFTS OFF TO
THE EAST. TEMPERATURES WILL CONTINUE TO BE MILD ON MONDAY. NO SIGN
OF AN ORGANIZED STORM SYSTEM...SO WILL KEEP POPS LOW. COULD BE
ENOUGH MOISTURE AND INSTABILITY FOR A FEW MOUNTAIN SHOWERS AND WILL
HAVE A SLIGHT CHANCE IN THE FORECAST.

AVIATION...ENHANCED SNOW BANDS WILL CONTINUE TO GENERATE THROUGH
THIS EVENING...SO SHOULD SEE IFR CIG/VSBYS BECOMING MORE
CONTINUOUS AFTER 23Z. CONDITIONS SHOULD BE THE WORST PRIOR TO 06Z
WITH SNOW BECOMING LIGHTER AND A GRADUAL IMPROVEMENT IN CIGS AND
VSBYS IN THE 06Z-12Z WINDOW. STORM TOTALS OF 2 TO 5 INCHES
EXPECTED THROUGH 12Z TUESDAY AT D.I.A. WITH UP TO 7 INCHES
POSSIBLE WITH AN ENHANCED SNOWBAND SETS UP OVER THE AIRPORT FOR 2
TO 3 HOURS.

.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 AM MDT TUESDAY FOR COZ033>036-039.

WINTER WEATHER ADVISORY UNTIL 6 AM MDT TUESDAY FOR COZ030>032-
038-040-041-043>046-049.

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

AREA FORECAST DISCUSSION

NWS PUEBLO CO

1138 PM MDT SAT APR 20 2013

.UPDATE...
ISSUED AT 1137 PM MDT SAT APR 20 2013

WILL ALLOW THE WINTER WEATHER ADVISORY FOR COLORADO PUBLIC ZONE 60
EXPIRE AT MIDNIGHT. ALSO...ADJUSTED SEVERAL GRIDS/ZONES TO REFLECT
LATEST NEAR TERM METEOROLOGICAL CONDITIONS.

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 312 PM MDT SAT APR 20 2013

SHORTWAVE PUSHING EASTWARD ACROSS COLORADO THIS AFTERNOON WAS
PRODUCING A GOOD DEAL OF VIRGA/LIGHT SHOWERS OVER THE
MOUNTAINS...THOUGH AMOUNT OF PRECIP REACHING THE GROUND IS LIKELY
MUCH LESS THAN RADAR SUGGESTS. HAVE EVEN SEE A COUPLE LIGHTNING
STRIKES OVER THE SRN SAN LUIS VALLEY NEAR THE NM BORDER...AS
LAPS/HRRR SUGGEST A LOCAL MAX OF INSTABILITY OVER THE VALLEY. NOT
SEEING MUCH SNOW YET ON CENTRAL MOUNTAIN WEB CAMS...THOUGH WILL KEEP
SNOW ADVISORY IN PLACE THE NEXT FEW HOURS TO ACCOUNT FOR SOME BRIEF
BURSTS OF SNOW UNDER HEAVIER CONVECTIVE SHOWERS. ELSEWHERE...WILL
KEEP SCATTERED POPS OVER THE MOUNTAINS INTO THE EVENING...WITH SOME
ISOLATED POPS FOR MAINLY VIRGA/SPRINKLES ALONG THE I-25 CORRIDOR.
COULD ALSO SEE SOME BRIEF GUSTY/ERRATIC WINDS OVER LOWER ELEVATIONS
AS PRECIP EVAPORATES WITHIN THE DRY SUB-CLOUD LAYER. DIDN`T INCLUDE
A MENTION OF THUNDER IN ANY AREAS...AS LATEST HRRR KEEP BEST
INSTABILITY NORTH OF THE PALMER DIVIDE. EXPECT MOST PRECIP TO END
QUICKLY WITH SUNSET AS INSTABILITY WANES AND UPPER WAVE MOVES
RAPIDLY INTO THE CENTRAL PLAINS. ON SUNDAY...WEAK SHORTWAVE MAY
SPARK SOME VIRGA/SPRINKLES OVER THE MTNS...BUT COVERAGE WILL BE MUCH
LESS THAN TODAY. MODELS TRY TO BREAK OUT SOME SPRINKLES OVER THE FAR
EASTERN PLAINS AS WELL...AS MODEST LOW LEVEL MOISTURE RETURNS
NORTHWARD. WILL IGNORE THIS FOR NOW...AS ANY PRECIP WILL BE VERY
LIGHT. WEST WINDS WILL PICK UP MOST AREAS AS UPPER JET MOVES ACROSS
AND FLOW IN THE 500/700 MB LAYER INCREASES TO 30-40 KNOTS...AND
LOCATIONS ACROSS THE HIGHER ELEVATIONS OF THE SANGRES/SAWATCH RANGES
WILL BECOME FAIRLY GUSTY BY AFTERNOON. MAX TEMPS LOOK WARMER MOST
AREA WITH BETTER MIXING AND A SUBTLE RISE IN 700 MB TEMPS...THOUGH
AT BEST...READINGS WILL STILL COME UP A COUPLE DEGF SHORT OF
SEASONAL MAXES.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 312 PM MDT SAT APR 20 2013

...ANOTHER STRONG COLD FRONT TO AFFECT THE AREA MONDAY AFTERNOON
THROUGH TUESDAY...

SUNDAY NIGHT-TUESDAY...LATEST MODELS IN DECENT AGREEMENT ON
DEVELOPING SYNOPTIC PATTERN THROUGH THE PERIOD...THOUGH CONTINUE TO
DIFFER ON AMOUNTS OF GENERATED PRECIPITATION. AT ANY RATE...WILL SEE
INCREASING WESTERLY FLOW ALOFT ACROSS THE REGION SUNDAY NIGHT AS AN
EMBEDDED SHORT WAVE EJECTS ACROSS THE NORTHERN ROCKIES AHEAD OF
PARENT TROUGH DIGGING INTO THE NORTHERN GREAT BASIN. COULD SEE A FEW
SHOWERS ACROSS MAINLY THE CENTRAL MTS THROUGH THE PIKES PEAK REGION
EARLY SUNDAY EVENING WITH FIRST PASSING WAVE WITH AN ASSOCIATED LEE
TROUGH TRANSLATING ACROSS THE EASTERN PLAINS KEEPING OVERNIGHT LOWS
ON THE MILD SIDE.

MODERATE TO STRONG WEST TO SOUTHWEST FLOW ALOFT PERSISTS ACROSS
THE AREA MONDAY AS PARENT SYSTEM CONTINUES TO TRANSLATE ACROSS THE
ROCKIES WITH FLOW ALOFT BECOMING MORE WEST TO NORTHWEST MONDAY NIGHT
AND TUESDAY AS UPPER TROUGH CONTINUES TO LIFT OUT ACROSS THE CENTRAL
HIGH PLAINS. MID LEVEL MOISTURE SLOWLY INCREASES FROM WEST TO EAST
ACROSS THE AREA MONDAY MORNING WITH A STRONG BACKDOOR COLD PUSHING
ACROSS EASTERN COLORADO LATE MONDAY MORNING AND AFTERNOON. MODELS A
TAD SLOWER WITH FRONT AND HAVE WARMED UP HIGHS SOME ACROSS EASTERN
COLORADO...WITH THE WARMEST READINGS EXPECTED SOUTH AND WEST OF THE
HIGHWAY 50 CORRIDOR. WITH THE INCREASING OROGRAPHIC FLOW AND UVV
AHEAD OF WAVE...SHOULD SEE SNOW INCREASING IN COVERAGE AND INTENSITY
ACROSS THE CENTRAL MTS MONDAY MORNING AND SPREADING EAST ACROSS THE
UPPER ARKANSAS RIVER VALLEY INTO THE PIKES PEAK REGION THROUGH THE
EARLY AFTERNOON. MODEL SOUNDINGS INDICATING LOWER ELEVATIONS RAPIDLY
SATURATING BEHIND FRONT WITH RAIN DEVELOPING ALONG AND BEHIND THE
FRONT. RAIN BECOMES MIXED WITH AND CHANGES TO SNOW LATE IN THE
AFTERNOON AND EARLY EVENING...ESPECIALLY ACROSS THE PALMER
DVD...WITH A POSSIBLE MESSY MONDAY EVENING COMMUTE. MODELS DIFFER ON
AMOUNT OF QPF ACROSS THE SE MTS MONDAY NIGHT THOUGH AGREE ON A BAND
OF MODERATE PRECIP DEVELOPING ACROSS THE CENTRAL MTS THROUGH THE
PIKES REGION MONDAY NIGHT THROUGH EARLY TUESDAY MORNING AS RRQUAD OF
JET TRANSLATES ACROSS SOUTH CENTRAL COLORADO. MAY NEED SOME
HIGHLIGHTS ACROSS THE CENTRAL MTS AND POSSIBLE THE PIKES PEAK REGION
IF LATEST MODELS REMAIN TRUE. COOL UPSLOPE FLOW PERSISTS ACROSS THE
PLAINS ON TUESDAY...WITH HIGHS WELL BELOW SEASONAL
AVERAGES...ESPECIALLY ACROSS THE EASTERN PLAINS.

WEDNESDAY-SATURDAY...A WARMING TREND TO NEAR SEASONAL AVERAGES
EXPECTED THROUGH THE PERIOD AS MODERATE NORTHWEST FLOW ALOFT
PERSISTS ACROSS THE REGION. A FEW EMBEDDED SHORT WAVE PROGGED TO
TRANSLATE THROUGH THE FLOW THURSDAY AND FRIDAY...OWNING TO A FEW
AFTERNOON AND EVENING SHOWERS ACROSS MAINLY THE HIGHER TERRAIN.

.AVIATION...ISSUED AT 1106 PM MDT SAT APR 20 2013

VFR CONDITIONS ARE EXPECTED TO CONTINUE FOR THE REMAINDER OF
TONIGHT AT THE KALS...KCOS AND KPUB TAF SITES.

.PUB WATCHES/WARNINGS/ADVISORIES...

WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ060.

AREA FORECAST DISCUSSION

NWS PUEBLO CO

1108 PM MDT SAT APR 20 2013

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 312 PM MDT SAT APR 20 2013

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 312 PM MDT SAT APR 20 2013

...ANOTHER STRONG COLD FRONT TO AFFECT THE AREA MONDAY AFTERNOON
THROUGH TUESDAY...

.AVIATION...ISSUED AT 1106 PM MDT SAT APR 20 2013

VFR CONDITIONS ARE EXPECTED TO CONTINUE FOR THE REMAINDER OF
TONIGHT AT THE KALS...KCOS AND KPUB TAF SITES.

.PUB WATCHES/WARNINGS/ADVISORIES...

WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ060.

AREA FORECAST DISCUSSION

NWS MIAMI FL

124 PM EDT SUN APR 21 2013

.AVIATION...
WIDELY SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE SEEN
CURRENTLY ON RADAR THIS AFTERNOON ACROSS SOUTHEAST FLORIDA WITH
THE VAST MAJORITY OF THUNDERSTORM ACTIVITY REMAINING OFFSHORE THE
ATLANTIC. LATEST HRRR KEEPS MOST OF THE ANTICIPATED ACTIVITY ALONG
THE EAST COAST THROUGH THE REMAINDER OF THE AFTERNOON AND EVENING.
ALSO LOOKS AS IF ANY FURTHER THUNDERSTORM DEVELOPMENT WILL BE
DRIVEN BY OUTFLOW BOUNDARIES WITH THE ABSENCE OF A GULF SEA BREEZE
THUS FAR. KEPT TEMPO GROUP FOR TSRA AT ALL EAST COAST TERMINALS
FROM 19Z-22Z.

.PREV DISCUSSION... /ISSUED 928 AM EDT SUN APR 21 2013/

UPDATE...
A LINE OF SHOWERS AND THUNDERSTORMS ALREADY DEVELOPED THIS MORNING
AND IS MOVING OUT TO SEA. AFTER LOOKING AT CURRENT MESOSCALE MODEL
RUNS AND THEIR ANTICIPATED COVERAGE OF CONVECTION TODAY, HAVE
ADJUSTED POPS SOMEWHAT. BUFKIT MBE VECTORS SHOW SLOW MOVING AND/OR
TRAINING CELLS TODAY, WHICH WILL LEAD TO HEAVY PRECIP, ESPECIALLY
WITH PWAT OF AROUND 1.75 INCHES. CAPE ON THIS MORNINGS SOUNDING IS
NEAR 3100 JOULES. LIS ARE -7.7 AND THE FREEZING LEVEL IS NEAR 14K
FT AND THE -20 IS NEAR 23K FT. ALSO, THE CAP THAT WAS IN PLACE
YESTERDAY, IS ALL BUT ERODED. SO, KEPT WORDING FOR GUSTY WINDS,
HEAVY RAIN AND SMALL HAIL. THE SHEAR IS NOT GREAT, NOR IS THE
HELICITY, OF ONLY 14. SO, THOUGHT IS SOME STORMS MAY BE ABLE TO
BECOME SEVERE, THEY MAY BE PULSE TYPE WITH DAMAGING WINDS MOST
LIKELY, WITH HAIL NEXT. THIS IS IN AGREEMENT WITH THE SPC OUTLOOK.

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 71 83 71 82 / 40 50 20 20
FORT LAUDERDALE 73 83 73 83 / 40 50 20 20
MIAMI 73 84 72 84 / 40 50 20 20
NAPLES 70 84 67 87 / 40 50 10 20

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

DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...10/CD

AREA FORECAST DISCUSSION

NWS MIAMI FL

143 AM EDT SUN APR 21 2013

.AVIATION...
MOST OF THE CONVECTION THROUGH EARLY IN THE FORECAST WILL REMAIN
OFFSHORE AND ALONG THE STATIONARY FRONTAL BOUNDARY NEAR LAKE
OKEECHOBEE. SOME LOW CLOUDS HAVE DEVELOPED JUST TO THE SOUTH OF
THE BOUNDARY WITH IFR CIGS CURRENTLY AT KAPF AND COULD HAVE
TEMPORARY MVFR CIGS ALONG THE EAST COAST. THESE WILL LIKELY
PERSIST UNTIL AROUND 12-13Z. AFTERNOON CONVECTION IS AGAIN
EXPECTED AFT 18Z WITH MOVEMENT TOWARDS THE EAST COAST TERMINALS.
SURFACE WIND WILL BE DRAINAGE FLOW EARLY WITH SEA BREEZES
DEVELOPING ALONG BOTH COASTS AFT 15-17Z.

KOB

.PREV DISCUSSION... /ISSUED 851 PM EDT SAT APR 20 2013/

UPDATE...
CONVECTION ENDED FOR THE EAST COAST EARLIER THIS EVENING. STORMS
RAPIDLY INTENSIFIED ONCE THEY HIT THE EAST COAST SEA BREEZE...WITH
A PEAK WIND GUST OF 72 MPH REPORTED NEAR HOLLYWOOD. TRANSVERSE
BANDS WERE EVIDENT IN VISIBLE SATELLITE IMAGERY EARLIER AS THE
NOSE OF THE SUBTROPICAL JET MOVED INTO THE GULF COAST. SHOWERS AND
EMBEDDED THUNDERSTORMS CONTINUE TO DEVELOP ALONG THE GULF
COAST...BUT THESE ARE EXPECTED TO BEGIN TO DIMINISH WITH THE LOSS
OF DAYTIME HEATING.

THE FRONTAL BOUNDARY MOVED INTO DEEP SOUTH FLORIDA BEFORE
STALLING LATE THIS AFTERNOON. IT IS BEGINNING TO WASH OUT
NOW...BUT A LOW LEVEL TROUGH WILL REMAIN ACROSS OR NEAR THE REGION
THROUGH MONDAY. THE UPPER LEVEL TROUGH WAS ACROSS THE GULF...BUT
THIS WILL MOVE EAST ON SUNDAY...WITH COOLER TEMPERATURES ALOFT
OVER SOUTH FLORIDA.

OVERNIGHT TONIGHT...SCATTERED SHOWERS AND FEW THUNDERSTORMS MAY
DEVELOP OVER THE GULF WATERS AHEAD OF THE UPPER TROUGH AND THE
SUBTROPICAL JET. UPPER LEVEL IMPULSES ARE FORECAST TO MOVE ACROSS
THE EASTERN GULF AND ACROSS CENTRAL/SOUTH FLORIDA SUNDAY AFTERNOON
INTO SUNDAY NIGHT...WITH STRONG TO POSSIBLY A COUPLE LOW END
SEVERE STORMS POSSIBLE. STORM MOTION WILL BE ALMOST NIL...WITH
STORM MOVEMENT DICTATED MOSTLY BY OUTFLOW AND SEA BREEZE
BOUNDARIES.

PREV DISCUSSION... /ISSUED 814 PM EDT SAT APR 20 2013/

AVIATION...
ALTHOUGH THE STRONG TO SEVERE THUNDERSTORMS THAT DEVELOPED EARLIER
OVER THE EAST COAST HAVE SHIFTED EAST OVER THE ATLANTIC WATERS AND
WEAKENED...ADDITIONAL SHOWERS AND STORMS HAVE DEVELOPED JUST
INLAND OF THE APF TERMINAL THIS EVENING. THIS ACTIVITY SHOULD
REMAIN JUST INLAND OF THE TERMINAL THROUGH THE MID EVENING HOURS
BEFORE TRENDING DOWN. OVERNIGHT...ANOTHER WEAK IMPULSE ALOFT
CURRENTLY LOCATED WEST OF THE FL PENINSULA OVER THE EASTERN GULF
COULD GENERATE ADDITIONAL SHOWERS AND STORMS LATER TONIGHT INTO
SUNDAY MORNING OVER THE GULF WATERS AND COASTAL AREAS INCLUDING
APF. HOWEVER...CONFIDENCE IS LOW AT THIS TIME DUE TO MODEL
DIFFERENCES BETWEEN THE HRRR AND WRF OUTPUT. AS A RESULT...WE WILL
INCLUDE MAINLY VCSH OVERNIGHT AND MONITOR THE ACTIVITY OVER THE
GULF FOR THE 06Z PACKAGE. LATER TOMORROW...MEAN LOW-LEVEL FLOW
WILL REMAIN LIGHT OUT OF THE SW. THIS FLOW COMBINED WITH WEAK
UPPER PULSES PASSING OVERHEAD AND THE EAST COAST SEA BREEZES WILL
BE ENOUGH TO SUPPORT THE POTENTIAL FOR ANOTHER ROUND OF
STRONG/SEVERE THUNDERSTORMS THROUGH THE AFTERNOON PERIOD TOMORROW
ALONG THE EAST COAST.

PREV DISCUSSION... /ISSUED 217 PM EDT SAT APR 20 2013/

DISCUSSION...

SATURDAY THROUGH MONDAY...

IN THE SHORT TERM FOR THIS AFTERNOON AND EVENING THERE IS NOT MUCH
CHANGE FROM THE PREVIOUS THINKING. THE SHOWERS AND THUNDERSTORMS
OVER THE ATLANTIC WATERS HAVE DIMINISHED IN COVERAGE BUT A FEW
SHOWERS ARE BEGINNING TO DEVELOP ALONG THE SEA BREEZE EXTENDING FROM
SOUTH MIAMI-DADE TO COASTAL PALM BEACH COUNTY AS WELL AS WEST OF
LAKE OKEECHOBEE ASSOCIATED WITH THE FRONT ITSELF. THIS PATTERN IS
CONSISTENT WITH THE FORECAST OF HIGH RESOLUTION MODELS FOR THIS
AFTERNOON AND EVENING. FAVORING FACTORS FOR THE FORMATION OF SHOWERS
AND THUNDERSTORMS ALONG THE EAST COAST ARE: THE WEAK SOUTHWESTERLY
FLOW AND THE TROUGH OF LOW PRESSURE NEAR THE FLORIDA EAST COAST. THE
LIMITING FACTORS ARE THE WARM 500 MB TEMPERATURES AND THE CAP AROUND
15KFT. IT IS POSSIBLE THAT ONCE THE ACTIVITY ALONG THE SEA BREEZE
REACHES THE CAP IT COULD DIMINISH IN INTENSITY BUT STILL PRODUCE
HEAVY RAINS, GUSTY WINDS, AND LIGHTNING. IN OTHER WORDS, IT COULD
START ACTIVE IN THE NEXT FEW HOURS AND THEN WEAKEN A BIT AS THE
STORMS START REACHING THE CAP. THE ADVANCE OF THE FRONT IS ALSO A
FAVORABLE FACTOR THAT IT COULD BECOME MORE IMPORTANT AS THE DAY
PROGRESSES. THE STEERING FLOW WILL MOVE STORMS GENERALLY FROM WEST
TO EAST. THIS WILL INCREASE THE POTENTIAL FOR THUNDERSTORMS FOR
THE EAST COAST.

THE CURRENT 500 MB PATTERN SHOWS A TROUGH OF LOW PRESSURE OVER THE
EASTERN AND CENTRAL US AND A STRONG BLOCKING RIDGE OF HIGH PRESSURE
OVER THE WESTERN ATLANTIC. AS THE HIGH CONTINUES TO MOVE FURTHER
EAST COOLER 500 MB TEMPERATURES WILL SPREAD OVER SOUTH FLORIDA ON
SUNDAY. THIS IS EXPECTED TO INCREASE THE POTENTIAL FOR STRONG OR
EVEN SEVERE STORMS ON SUNDAY IF HEATING IS FAVORABLE.

LONG TERM /TUESDAY THROUGH FRIDAY/...
BEHIND THE SURFACE TROUGH...A MORE TYPICAL SPRING WEATHER REGIME
WILL TAKE HOLD OVER FLORIDA...WITH EASTERLY LOW-LEVEL FLOW AND
HIGH PRESSURE BUILDING BOTH NEAR SURFACE AND ALOFT. ISOLATED
MAINLY DIURNAL SHOWERS ARE EXPECTED...WITH PARTLY TO MOSTLY SUNNY
SKIES AND TEMPERATURES REMAINING SLIGHTLY ABOVE AVERAGE.

AVIATION...ISSUED AT 147 PM EDT SAT APR 20 2013...
SHOWERS AND THUNDERSTORMS ARE BEGINNING TO SAG INTO THE NORTHWEST
INTERIOR AREAS. WITH AN ESTABLISHED GULF COAST SEA BREEZE...THIS
ACTIVITY SHOULD CONTINUE TO PUSH TO THE EAST. ADDITIONAL
CONVECTION WILL ALSO BE POSSIBLE ACROSS THE EAST COAST TERMINALS
OVER THE NEXT FEW HOURS OF PEAK HEATING. KEPT TEMPO GROUPS AT ALL
EAST COAST SITES FROM 20Z-23Z. WILL AMEND IF NECESSARY.

MARINE...
LONG-FUSED ADVISORIES AND WARNINGS ARE NOT EXPECTED THIS WEEKEND
OR NEXT WEEK OVER THE WATERS. LOCALLY HIGH WAVES AND WINDS CAN BE
EXPECTED IN SCATTERED TO NUMEROUS THUNDERSTORMS TODAY THROUGH
MONDAY...AND SPECIAL MARINE WARNINGS MAY BE ISSUED FROM TIME TO
TIME.

FIRE WEATHER...
MINIMUM RELATIVE HUMIDITY VALUES WILL BE ABOVE 50 PERCENT THIS
WEEKEND AND EARLY NEXT WEEK...AS MOIST ATMOSPHERE CONTRIBUTES TO
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. WINDS WILL MAINLY
SOUTH TODAY...BUT TRANSITION TO THE NORTHEAST TONIGHT AS COLD FRONT
MOVES IN. LOW WIND SPEEDS ARE EXPECTED OUTSIDE OF SHOWERS AND
THUNDERSTORMS.

PREV DISCUSSION... /ISSUED 947 AM EDT SAT APR 20 2013/

UPDATE...

SHOWERS AND THUNDERSTORMS OVER THE ATLANTIC WATERS HAVE DEVELOPED
THIS MORNING DUE TO THE CONVERGENCE OF SE FLOW OVER THE BAHAMAS
AND MORE SOUTHERLY FLOW OVER SOUTH FLORIDA. THE 12Z SOUNDING FROM
THIS MORNING SHOWS A CAP AROUND 650 MB ASSOCIATED WITH THE
SUBTROPICAL HIGH PRESSURE OVER THE ATLANTIC AND THE GULF. 500 MB
TEMPERATURES ARE AROUND -6C AND ARE NOT EXPECTED TO COOL BEYOND
-7C THIS AFTERNOON. HOWEVER, THE INFLUENCE OF A COLD FRONT MOVING
SOUTHWARD IS EXPECTED TO INTERACT WITH A WEAK EAST COAST SEA
BREEZE TO TRIGGER SHOWERS AND THUNDERSTORMS, ESPECIALLY IN PALM
BEACH AND BROWARD COUNTIES. SOME STORMS CAN ALSO EXTEND INTO
MIAMI-DADE. FOR THE WEST COAST THERE IS ONLY A SMALL CHANCE OF
THUNDERSTORMS, SINCE MOST OF THE SURFACE TROUGH IS ALIGNED FROM
NORTHEAST TO SOUTHWEST OVER THE ATLANTIC WATERS.

AS MENTIONED IN THE PREVIOUS DISCUSSION THE UPPER LEVEL
TEMPERATURES ARE FORECAST TO COOL ON SUNDAY ALLOWING FOR A GREATER
CHANCE OF THUNDERSTORMS THAN TODAY.

FOR TODAY THE HIGHEST POPS ARE STILL INCLUDED FOR PALM BEACH AND
BROWARD.

PREV DISCUSSION... /ISSUED 725 AM EDT SAT APR 20 2013/

AVIATION...
MOSTLY VFR CONDITIONS WILL OCCUR EARLY IN THE FORECAST ALTHOUGH
THERE COULD BE A BRIEF MVFR CIG AS A FEW SHOWERS MOVE ACROSS SOUTH
FLORIDA. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP BY THIS AFTERNOON AHEAD OF A WEAKENING COLD
FRONT THAT WILL SAG ACROSS THE REGION. THE HRRR INDICATES
CONVECTION TO BEGIN DEVELOPING IN EARNEST BETWEEN 18-20Z WITH THE
STEERING FLOW TAKING THE STORMS TO THE EAST COAST. THEREFORE, HAVE
LEFT TEMPO 18-22Z FOR ALL EAST TERMINALS WITH SOME OF THE ACTIVITY
POSSIBLY PERSISTING BEYOND THIS TIME FRAME. SURFACE WINDS ARE
QUESTIONABLE WITH A SLOW MOVING FRONTAL BOUNDARY BUT GENERALLY
SSW-SSE AHEAD OF THE FRONT AND NE BEHIND THE FRONT.

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

AREA FORECAST DISCUSSION

NWS LINCOLN IL

845 PM CDT MON APR 22 2013

.DISCUSSION...
ISSUED 842 PM CDT MON APR 22 2013

INITIAL BAND OF SHOWERS TO OUR WEST MAKING SLOW PROGRESS EAST INTO
EASTERN MISSOURI AND IOWA...BUT BASED ON OUR 00Z SOUNDING...MAY HAVE
A TOUGH TIME HOLDING TOGETHER AS IT MOVES INTO CENTRAL IL LATER THIS
EVENING. LEAD SHORTWAVE CLEARLY SEEN ON THE WATER VAPOR LOOP OUT OVER
THE MISSOURI RIVER BASIN AND WAS TRACKING STEADILY TO THE EAST. A
MUCH MORE POTENT UPPER WAVE WAS SEEN DIGGING SOUTHEAST INTO THE CENTRAL
ROCKIES AND THIS WAVE WILL BRING THE STEADIER RAINS INTO THE FORECAST
AREA ON TUESDAY/TUESDAY NIGHT. CURRENT SURFACE MAP SHOWING A BIT MORE
LOW LEVEL MOISTURE ACRS THE SOUTHERN PLAINS AHEAD OF THE STRONGER WAVE
AND THAT MOISTURE WILL CONTINUE TO STREAM NORTHEAST TOWARDS THE MIDWEST
ALONG AND JUST AHEAD OF A COLD FRONT...WHICH AT 00Z WAS LOCATED OVER
PARTS OF CENTRAL IOWA. QUITE A LARGE AREA OF SNOW ON THE BACKSIDE
OF THE SYSTEM AS LATE AFTERNOON AND EARLY EVENING TEMPERATURES STRUGGLE
THRU THE UPPER 20S TO LOWER 30S. CURRENT ZONE FORECAST HAS A VERY GOOD
HANDLE ON THE TRENDS THIS EVENING AND INTO THE OVERNIGHT HOURS...SO
OTHER THAN SOME MINOR ADJUSTMENTS TO THE HOURLY TEMP GRIDS...NO OTHER
CHANGES WILL BE NEEDED THAT WOULD WARRANT A ZFP UPDATE AT THIS TIME.

.AVIATION...
ISSUED 630 PM CDT MON APR 22 2013

MAIN FORECAST CONCERN THIS PERIOD WILL BE WITH DETERIORATING CIGS
AND VSBYS WITH INCREASING COVERAGE OF RAIN AND ISOLATED TSRA LATE
TONIGHT AND ESP DURING THE DAY TUESDAY. VFR CONDITIONS SHOULD LAST
THRU ABOUT 09Z BEFORE CIGS BEGIN TO LOWER AS MOISTURE ADVECTS NE
INTO OUR AREA AHEAD OF AN APPROACHING FRONTAL SYSTEM. ONE BAND OF
SHOWERS MAY APPROACH OUR AREA AFTER 03Z AND TRACK ACRS THE AREA
DURING THE EARLY MORNING HOURS WITH NOT MUCH OF AN AFFECT ON CIGS
BUT THE SECOND DISTURBANCE WILL PUSH INTO CENTRAL ILLINOIS LATER
TUESDAY MORNING INTO THE AFTERNOON BRINGING ALL CIGS DOWN TO LOW
MVFR WITH TEMPO IFR CONDITIONS IN RAIN AND ISOLD TSRA. THE LOW
CIGS WILL CONTINUE INTO TUESDAY EVENING. SFC WINDS WILL BE OUT OF
THE SOUTHEAST TONIGHT AT 10 TO 15 KTS...AND THEN GRADUALLY VEER MORE
INTO A SSW DIRECTION TUESDAY AHEAD OF THE FRONT WITH SPEEDS OF 12 TO
17 KTS WITH OCCASIONAL GUSTS UP TO 22 KTS BEFORE THE WIND SHIFTS
JUST AFTR FROPA INTO A NW-N (310-340 DEG) AT 12 TO 17 KTS WITH A FEW
GUSTS JUST ABOVE 20 KTS AT TIMES.

SMITH
&&

.PREV DISCUSSION...
ISSUED 259 PM CDT MON APR 22 2013

MAIN WEATHER STORY CONTINUES TO BE THE RAIN EVENT COMING INTO THE
PICTURE LATE TONIGHT THROUGH TUESDAY NIGHT.

19Z/2PM SURFACE MAP SHOWS HIGH PRESSURE EXTENDING FROM NEW ENGLAND
TO THE WESTERN GULF OF MEXICO. FURTHER NORTHWEST...LOW PRESSURE IS
CENTERED NEAR HUDSON BAY...WITH STRONG COLD FRONT TRAILING
SOUTHWESTWARD INTO THE CENTRAL PLAINS. ALOFT...LARGE RIDGE IS IN
PLACE OVER THE EASTERN PACIFIC...WHILE A VIGOROUS SHORT-WAVE
DROPPING INTO THE CENTRAL ROCKIES IS BEGINNING TO DIG A TROUGH
DOWNSTREAM ACROSS THE CENTRAL CONUS.

SHORT TERM...TONIGHT THROUGH THURSDAY

LEAD SHORT-WAVE CURRENTLY EVIDENT ON WATER VAPOR IMAGERY OVER
WESTERN NEBRASKA/KANSAS WILL TRACK EASTWARD THIS EVENING. CLUSTER
OF THUNDERSTORMS ASSOCIATED WITH THIS FEATURE WEST OF KANSAS CITY
WILL SHIFT EASTWARD AND WEAKEN WITH TIME AS IT ENCOUNTERS A MUCH
DRIER AIRMASS FURTHER EAST ACROSS ILLINOIS. 3KM HRRR SHOWS REMNANTS
OF THIS CONVECTION TRYING TO WORK ITS WAY INTO WEST-CENTRAL
ILLINOIS BETWEEN 00Z AND 03Z...HOWEVER QPF AMOUNTS ARE PALTRY.
BASED ON INITIALLY VERY DRY FORECAST SOUNDINGS...THINK THIS FIRST
WAVE WILL DO LITTLE MORE THAN TO MOISTEN THE AIRMASS FOR THE MAIN
WAVE ON TUESDAY. HAVE THEREFORE DOWNPLAYED RAIN CHANCES EARLY
TONIGHT...FEATURING ONLY LOW CHANCE POPS FOR SHOWERS WEST OF I-55
THROUGH MIDNIGHT. RAIN CHANCES BEGIN TO INCREASE OVERNIGHT...AS
MAIN WAVE AND ASSOCIATED COLD FRONT APPROACHES FROM THE WEST.
SOUNDINGS SHOW AT LEAST MODEST ELEVATED INSTABILITY...SO WILL
MENTION CHANCE FOR THUNDER AFTER MIDNIGHT.

FRONTAL BOUNDARY SLOWLY PUSHES EASTWARD THROUGH CENTRAL ILLINOIS
ON TUESDAY...WITH SURFACE LOW PRESSURE EXPECTED TO RIDE ALONG THE
BOUNDARY AS IT DOES SO. COMBINATION OF STRONG LOW-LEVEL FORCING
ALONG FRONT...VIGOROUS UPPER DYNAMICS COMING IN FROM THE WEST...AND
INCREASINGLY DEEP MOISTURE WITH PRECIPITABLE WATER VALUES
EXCEEDING 1 INCH...WILL LEAD TO THE DEVELOPMENT OF WIDESPREAD
SHOWERS AND THUNDERSTORMS ACROSS THE AREA. AM NOT ANTICIPATING
SEVERE WEATHER...HOWEVER A FEW STRONG THUNDERSTORMS WILL BE
POSSIBLE EAST OF I-55 DURING THE AFTERNOON. BEST INSTABILITY AND
SHEAR PARAMETERS WILL REMAIN FOCUSED A BIT FURTHER SOUTHWEST
ACROSS THE OZARKS AND LOWER OHIO RIVER VALLEY.

ONCE SURFACE LOW LIFTS INTO THE GREAT LAKES...FRONT WILL GET
PULLED EASTWARD INTO INDIANA BY EARLY EVENING. ALL OPERATIONAL
MODELS SUGGEST PLENTY OF SHOWERS LINGERING BEHIND THE BOUNDARY AT
LEAST THROUGH MIDNIGHT. HAVE THEREFORE MAINTAINED HIGH POPS
THROUGH THE EVENING...WITH STEADILY DECREASING CHANCES AFTER
MIDNIGHT. MAY EVEN BE ENOUGH COLD AIR ADVECTING INTO THE AREA
BEHIND THE FRONT TO CHANGE THE RAIN SHOWERS TO A BRIEF PERIOD OF
SNOW SHOWERS ACROSS THE ILLINOIS RIVER VALLEY OVERNIGHT...HOWEVER
THINK MOST OF THE MOISTURE WILL DEPART BEFORE IT GETS COLD ENOUGH
FOR THAT TO HAPPEN. WILL HOWEVER MENTION JUST A SLIGHT CHANCE FOR
SNOW SHOWERS ACROSS THE FAR WESTERN KILX CWA IN CASE MOISTURE
LINGERS. TOTAL RAINFALL FROM THIS SYSTEM WILL GENERALLY BE BETWEEN
THREE QUARTERS AND ONE INCH...HOWEVER AMOUNTS IN EXCESS OF ONE
INCH WILL BE LIKELY EAST OF I-55 WHERE A FEW STRONGER STORMS MAY OCCUR.

MUCH COOLER/DRIER AIRMASS WILL ARRIVE ON WEDNESDAY AND
THURSDAY...WITH HIGHS DROPPING BACK INTO THE 50S AND OVERNIGHT
LOWS DIPPING INTO THE 30S. MODELS STILL SHOW A NORTHERN-STREAM
SHORT-WAVE TRACKING ACROSS THE UPPER MIDWEST AND GREAT LAKES
WEDNESDAY NIGHT...HOWEVER THINK MOISTURE WILL BE LACKING AND
STRONGEST LIFT WILL REMAIN WELL TO THE NORTH. HAVE THEREFORE ONLY
MENTIONED A CHANCE FOR SPRINKLES/FLURRIES FROM THE PEORIA AREA
NORTHWARD.

LONG TERM...FRIDAY THROUGH MONDAY

MODELS CONTINUE TO STRUGGLE WITH THE POTENTIAL SYSTEM AT THE END
OF THE WEEK. SYSTEM IN QUESTION IS A CUT-OFF LOW OFF THE COAST OF
SOUTHERN CALIFORNIA THAT WILL EVENTUALLY GET ABSORBED INTO THE
PREVAILING W/NW FLOW ACROSS THE CONUS AND GET EJECTED EASTWARD BY
FRIDAY/SATURDAY. GFS HAS CONSISTENTLY BEEN FASTER AND FURTHER
NORTH WITH ITS TRACK...SPREADING RAIN INTO CENTRAL ILLINOIS
FRIDAY/FRIDAY NIGHT. MEANWHILE...ECMWF HAS BEEN CONSISTENTLY
SLOWER AND FURTHER SOUTH...KEEPING MUCH OF THE RAIN ACROSS THE
TENNESSEE AND OHIO RIVER VALLEYS ON SATURDAY/SUNDAY. GEM SUPPORTS
THE SLOWER ECMWF...SO WILL TREND TOWARD THIS SOLUTION FOR THE
EXTENDED. AS A RESULT...HAVE OPTED TO KEEP FRIDAY DRY...WITH LOW
CHANCE POPS ARRIVING FRIDAY NIGHT. AFTER THAT...HAVE CONFINED RAIN
CHANCES TO MAINLY THE SOUTHERN CWA ON SATURDAY...WITH MAIN FOCUS
FOR MORE SIGNIFICANT RAINFALL REMAINING SOUTH OF THE AREA.

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

AREA FORECAST DISCUSSION

NWS LINCOLN IL

640 PM CDT MON APR 22 2013

.DISCUSSION...
ISSUED 259 PM CDT MON APR 22 2013

MAIN WEATHER STORY CONTINUES TO BE THE RAIN EVENT COMING INTO THE
PICTURE LATE TONIGHT THROUGH TUESDAY NIGHT.

SHORT TERM...TONIGHT THROUGH THURSDAY

LONG TERM...FRIDAY THROUGH MONDAY

.AVIATION...
ISSUED 630 PM CDT MON APR 22 2013

SMITH
&&

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

AREA FORECAST DISCUSSION

NWS GOODLAND KS

818 PM MDT MON APR 22 2013

.UPDATE...
ISSUED AT 817 PM MDT MON APR 22 2013

01Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED TROUGH DIGGING INTO
NORTHERN UTAH AND NORTHWEST COLORADO WITH 100KT+ H3 JET STREAK
EXTENDING AHEAD OF THE TROUGH AND ACROSS CWA. 00Z RAOBS INDICATE
DEEP COLD AIR MASS EXTENDING AS HIGH AS 675MB AT DNR. AT THE
SFC...1032 MB SFC HIGH WAS BUILDING INTO THE REGION WITH COLD FRONT
AS FAR SOUTH AS THE TEXAS PANHANDLE.

WITH WINDS GRADUALLY DECREASING MAIN CONCERN WILL CENTER AROUND
SNOWFALL AMOUNTS THROUGH THE NIGHT. AM A LITTLE CONCERNED THAT BOTH
NAM AND RAP SUPPORT A PERIOD OF ELEVATED INSTABILITY NEAR GLD
THROUGH 7Z WITH MUCAPES AROUND 100 J/KG BRINGING THE POTENTIAL FOR
ENHANCED SNOWFALL RATES IN THIS AREA.

COMPOSITE REFLECTIVITY/SNOW OBSERVATIONS INDICATING MODERATE TO
HEAVY SNOW HAS BEEN OCCURRING WITH FAIRLY WIDESPREAD 2-3 INCHES
ALREADY OBSERVED FROM JUST EAST OF FLAGLER TO GOODLAND AND WITH
INSTABILITY PROFILES AND STRONG H65 FRONTOGENESIS ACROSS THIS AREA
THROUGH 6Z THINK HEAVIER PRECIPITATION WILL CONTINUE FROM A JOES TO
RUSSEL SPRINGS LINE...WITH MUCH LOWER AMOUNTS EXPECTED TO THE
SOUTHWEST OF THAT AREA. GIVEN POTENTIAL FOR ELEVATED CONVECTION...AM
CONCERNED THAT SOME LOCATIONS MAY GET TO THE 6-8 INCH RANGE BUT WITH
CONVECTIVE NATURE OF PRECIP AND FORCING GRADUALLY TRANSITIONING TO
THE SOUTH EAST...CONFIDENCE NOT QUITE HIGH ENOUGH FOR AN UPGRADE TO
A WARNING AT THIS POINT.

UPDATE ISSUED AT 701 PM MDT MON APR 22 2013

STRONGEST PRESSURE RISES WELL TO THE SOUTH OF THE AREA AS COLD
FRONT NOW ENTERING THE TEXAS PANHANDLE. WINDS HAVE DIMINISHED
ACROSS MUCH OF THE AREA AND HAVE FALLEN WELL BELOW ADVISORY LEVELS
AND HAVE CANCELED ALL BUT THE SOUTHERN TWO TIERS OF COUNTIES WHERE
OBSERVATIONS REMAIN SOMEWHAT STRONGER. WILL LIKELY REMOVE REST OF
ADVISORY BEFORE EXPIRATION TIME.

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 223 PM MDT MON APR 22 2013

A NEGATIVELY TILTED LONGWAVE H5 TROUGH WAS DIGGING ACROSS THE
WESTERN CONUS TODAY AND WILL MOVE THROUGH THE CENTRAL US TONIGHT
INTO TOMORROW. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM HAS
ALREADY MOVED THROUGH THE ENTIRE CWA BRINGING GUSTY NORTHERLY WINDS
AND COOLER TEMPS.

PRECIP SHOULD BEGIN AS SNOW AS TEMPS DECREASE RAPIDLY LATE THIS
AFTERNOON ACROSS THE REGION. MOST GUIDANCE WAS FAIRLY AGGRESSIVE
WITH QPF/SNOW AMOUNTS BUT GIVEN THE SATURATED COLUMN DID NOT GO TOO
MUCH LOWER WITH THE FORECAST...AMOUNTING TO A TOTAL OF 1 TO 3 INCHES
ACROSS THE CWA. BEST CHANCE FOR PRECIP LOOKS TO BE SOUTH OF I-70.
THINK LIGHT SNOW SHOWERS IN FAR SOUTH COUNTIES ARE NOT OUT OF THE
QUESTION TOMORROW AS TROUGH AXIS EXITS THE REGION...BUT MOST OF THE
SNOWFALL WILL OCCUR TONIGHT. TEMPS WILL REACH NEAR-RECORD LOWS
TONIGHT AND WILL STRUGGLE TO REACH THE UPPER 30S TOMORROW AFTERNOON.
WIND CHILLS TONIGHT WILL BE IN THE SINGLE DIGITS...QUITE FRIGID FOR
LATE APRIL.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 223 PM MDT MON APR 22 2013

RELATIVELY QUIET WEATHER WILL SET IN FOR THE TRI-STATE AREA
THROUGHOUT THE EXTENDED FORECAST. A WARMING TREND IS ALSO
EXPECTED...WITH A RETURN TO NEAR AND ABOVE NORMAL TEMPERATURES
FORECAST BY THURSDAY. ABOVE NORMAL TEMPERATURES ARE LIKELY THROUGH
THE WEEKEND AND INTO THE BEGINNING OF NEXT WEEK.

AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE PLAINS ON WEDNESDAY.
MODELS HAVE TRENDED FURTHER NORTH WITH THIS SYSTEM SO HAVE CONTINUED
A DRY FORECAST. NORTHWEST WINDS SHOULD PICK UP AHEAD THE DISTURBANCE
ON WEDNESDAY AFTERNOON. HIGH TEMPERATURES ON WEDNESDAY SHOULD CLIMB
INTO THE MID 50S.

THE NEXT UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THURSDAY NIGHT
AND INTO FRIDAY. WITH WARMER TEMPERATURES...SOME INSTABILITY
FORECAST BY MODELS AS WELL AS DECENT LAPSE RATES AND A POSSIBLE
DRYLINE IN THE AREA...THERE COULD BE A CHANCE FOR SOME
THUNDERSTORMS. MODELS PROJECT THE SHORTWAVE WILL PASS THROUGH DURING
THE OVERNIGHT HOURS THURSDAY...WHICH WOULD LIMIT THE CHANCES FOR
STRONG TO SEVERE THUNDERSTORMS. IF THE SHORTWAVE SLOWS DOWN AND PASS
THROUGH LATER IN THE DAY ON FRIDAY...THERE WILL BE A BETTER CHANCE FOR
SOME STRONG THUNDERSTORMS.

THE COMING WEEKEND LOOKS VERY NICE WITH LITTLE CHANCE OF
PRECIPITATION AND TEMPERATURES IN THE 70S...NEARING OR EXCEEDING 80
IN SOME LOCATIONS. WITH DRIER AIR TO THE WEST...FIRE WEATHER COULD
BECOME A CONCERN BUT WINDS ARE PROJECTED TO BE FAIRLY LIGHT AT THE
PRESENT TIME.

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 519 PM MDT MON APR 22 2013

PERIOD OF MFVR OR LOWER FLIGHT CONDITIONS EXPECTED AT BOTH
TERMINALS TONIGHT WITH THE HIGHEST IMPACT/LOWEST FLIGHT CATEGORIES
EXPECTED AT GLD AS AREA OF MODERATE TO HEAVY SNOW WILL CONTINUE TO
MOVE ACROSS THE AREA FOR THE NEXT FEW HOURS. LOOKING AT VERTICAL
STABILITY PROFILES...HAVE CONCERN THAT AT LEAST MODERATE SNOW WILL
CONTINUE THROUGH 8Z...BUT WANT TO SEE HOW THINGS DEVELOP THROUGH
THE NEXT FEW HOURS BEFORE COMMITTING TO WIDESPREAD PERSISTENT LIFR
CONDITIONS. WINDS WILL GRADUALLY WEAKEN THROUGH THE
EVENING...ALTHOUGH WILL REMAIN IN THE 15-22KT RANGE FOR MUCH OF
THE PERIOD.

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 9 AM MDT /10 AM CDT/ TUESDAY FOR
KSZ001-013>016-027>029-041-042.

CO...WINTER WEATHER ADVISORY UNTIL 9 AM MDT TUESDAY FOR COZ090>092.

NE...NONE.
&&

UPDATE...JRM
SHORT TERM...JJM
LONG TERM...RRH
AVIATION...JRM

AREA FORECAST DISCUSSION

NWS BALTIMORE MD/WASHINGTON DC

918 PM EDT MON APR 22 2013

.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTHWARD OFF THE MID-ATLANTIC COAST TONIGHT
THROUGH TUESDAY. THIS WILL BE FOLLOWED BY A COLD FRONTAL PASSAGE
WEDNESDAY AND THURSDAY. HIGH PRESSURE MOVES IN FOR FRIDAY AND
SATURDAY. ANOTHER AREA OF LOW PRESSURE MAY APPROACH THE REGION
EARLY NEXT WEEK.

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
01Z SFC ANALYSIS SHOWS HIPRES...WHICH IS CENTERED OVER THE
CANADIAN MARITIME...WAS RIDGING SWD ALONG THE COASTAL SIDE OF THE
APPALACHIANS. DOWNSTREAM OF THE RIDGE...AN INVERTED PRESSURE
TROUGH EXTENDS NWD FROM THE NWRN CARIBBEAN TO OFF THE NC COAST.
NEAR-TERM MODELS CONTINUE TO INDICATE CYCLOGENESIS OCCURRING TNGT
OFF THE CAROLINA COAST AS MOVES OVER THE WARM GULF STREAM AND AN
UPPER TROUGH APPROACHES THE ERN SEABOARD.

STRATOCU ON NWRN FRINGE OF THE TROUGH...WHICH HAS REACHED CHO-IAD-
BWI...WILL CONTINUE TO SPREAD NWD THIS EVE. COOL/MOIST MARINE
AIRMASS ESTABLISHES LATE TNGT AS THE PRESSURE GRADIENT BETWEEN
THESE TWO SYSTEMS RESULTS IN PERSISTENT E TO NE FLOW. THIS SETUP
FAVORS THE INLAND ADVECTION OF STRATUS AND PERHAPS DRIZZLE OVER
ERN PORTIONS OF THE CWA. HAVE BACKED OFF ON POPS/RAIN AS FORCING
AND ISENTROPIC LIFT IS VERY SHALLOW. BASED ON 18Z NAM /WHICH HAS
CAPTURED CLOUD COVER WELL SO FAR TDA/ AND HRRR /WHICH HAS
PERFORMED WELL IN RECENT STRATUS EVENTS/...KEPT LOW CLOUDS MAINLY
EAST OF THE BLUE RIDGE.

MIN TEMPS IN THE 30S ARE EXPECTED FOR AREAS NEAR AND WEST OF THE
BLUE RIDGE THAT EXPERIENCE MAINLY CLEAR SKIES AND LIGHTER WINDS.
THE HIGHEST MIN TEMPS ARE EXPECTED EAST OF I-95 OWING TO CLOUD
COVER AND STRONGER WINDS.

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
SFC LOW PRES WELL OFFSHORE WILL DEEPEN AS IT MOVES NEWD ON TUE BUT
THE LOW WILL BE MOVG AWAY BY AFTN AND SFC RIDGE WILL REMAIN
BASICALLY IN CONTROL. CLOUDS SHOULD BE BREAKING UP BY MIDDAY AND
MAX TEMPS SHOULD BE SEVERAL DEGS HIGHER THAN TODAY SPCLY OVER
AREAS W OF DC. CLOUDS WILL REMAIN LONGEST OVER THE EAST AND THIS
MAY HOLD TEMPS DOWN SOMEWHAT. SFCS WINDS WILL BE LIGHT WITH THE
HIGH PRES RIDGE.

WEAK SFC HIGH PRES AND LIGHT WINDS WILL CONT TUESDAY NIGHT. SKIES
SHOULD BE MOSTLY CLEAR ALTHOUGH SOME HIGH CLOUDS WILL BE SPREADING
IN LATER AHEAD OF THE NEXT UPPER TROF AND ASSOCD FRONTAL SYS OVER
THE GRTPLNS/OH VLY. FOR WED...THE NEXT COLD FRONT WILL BE
APPROACHING AND WILL LIKELY CROSS THE AREA BEGINNING LATE WED AFTN
THRU WED EVEN. THE CURRENT FCST HAS LOW CHC POPS OVER THE MTNS EARLY
WED MORN WITH INCRG CHCS FOR SHRA/TSRA SPREADING EWD DURINIG THE
DAY. INCRG SLY WINDS WILL BRING MORE WARMTH/MOISTURE INTO THE AREA
WITH MAX TEMPS ON WED MOSTLY IN THE 70S.

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE PERIOD WILL START WITH A COLD FRONTAL PASSAGE. RIGHT NOW THINK
THE FRONT WILL BE THROUGH THE REGION AND ANY PRECIPITATION CHANCES
PRETTY MUCH DONE BY THURSDAY NIGHT. HIGH PRESSURE WILL KEEP
FRIDAY AND MOST OF SATURDAY DRY. INCREASED CLOUDS AND LOW SHOWER
CHANCES SLOWLY FROM WEST TO EAST SATURDAY AHEAD OF THE NEXT LOW
PRESSURE SYSTEM. WITH THE INCREASE IN CLOUDS WENT SLIGHTLY COOLER
THAN WPC FOR HIGHS ON SATURDAY. THERE IS POTENTIAL FOR A MORE
SUBSTANTIAL PERIOD OF SHOWERS/RAIN DUE TO OVERRUNNING. HOWEVER
WITH TIMING UNCERTAINTIES WENT WITH MORE GENERIC ON PRECIPITATION
PLACEMENT AND SLOWER ON THE TIMING. THIS LOW PRESSURE SYSTEM WILL
LIKELY BE WITH US THROUGH EARLY NEXT WEEK AND HAVE KEPT LOW
CHANCES OF SHOWERS IN PLACE. THE TEMPERATURES WILL BE HIGHLY
DEPENDENT ON THE EXACT TRACK OF THE LOW PRESSURE CENTER. THE GFS
IS FURTHER NORTH AND THUS WARMER THAN THE EC. OVERALL WENT WITH
THE COMPROMISE APPROACH WHICH MATCHED WELL WITH WPC. ALSO USED WPC
GUIDANCE FOR WINDS.

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
BINOVC STRATOCU DECK BETWEEN 4-5 KFT HAS OVERSPREAD FROM THE
SOUTH...REACHING ALL TERMINALS EXCEPT MRB AS OF 01Z. BIGGEST FCST
CHALLENGE IS PREDICTING TIMING/EXTENT OF STRATUS DECK OVNGT. HAVE
FAVORED THE 18Z NAM/HRRR FOR ANTICIPATION OF STRATUS LATE
TNGT...BUT PUSHED BACK ONSET OF IFR CIGS A FEW HRS WITH A DRY
BOUNDARY LAYER CURRENTLY IN PLACE. SOME DRIZZLE MAY OCCUR FROM DCA
EWD BUT IS NOT EXPECTED TO HAVE MUCH EFFECT ON VSBY. WINDS WILL
CONT OUT OF THE NE OVER NIGHT 5 TO 15 KT.

SOME MVFR CIGS MAY CONTINUE TUESDAY MORNING BUT SHOULD IMPROVE
FROM WEST TO EAST BY MIDDAY. NE WINDS IN THE MORNING SHOULD BECOME
LIGHT IN THE AFTN WITH A WEAK SFC RIDGE BUILDING OVRHD.

GENERALLY VFR CONDS ARE EXPECTED TUESDAY AFTN THROUGH SATURDAY ALTHOUGH
TEMP MVFR/IFR CONDS ARE POSSIBLE IN SHOWERS AND TSTMS AHEAD OF A
COLD FRONT MOVING THROUGH LATE WEDNESDAY AFTERNOON OR EVENING AND
AGAIN WITH SPOTTY SHOWERS LATE SATURDAY.

.MARINE...
PRESSURE GRADIENT STRENGTHENS TNGT AS SFC LOPRES TRACKS NWD OFF
THE MID-ATLANTIC COAST. SCA IN EFFECT THRU LATE TNGT FOR THE CHSPK
BAY AND LWR/MID TIDAL POTOMAC RVR. ELY FLOW BACKS SLIGHTLY...
BECOMING NELY OVNGT. LOCAL VSBY RESTRICTIONS POSSIBLE OVER THE
WATERS LATE TNGT WHERE DRIZZLE AND PATCHY FOG DEVELOPS.

WINDS SHOULD DIMINISH TUESDAY AFTER 15Z AS THE LOW MOVES AWAY
FROM THE AREA. FAIR WX IS EXPECTED BY TUESDAY AFTN AND CONTINUING
THROUGH MOST OF WEDNESDAY. SCT SHOWERS/TSTMS ARE EXPECTED BY LATE
WED AFTN AHEAD OF A COLD FRONT. SCA CONDITIONS ARE EXPECTED FROM
THURSDAY NIGHT THROUGH MONDAY ATTM.

.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES ALONG THE WRN SHORE AND TIDAL POTOMAC HAVE
INCREASED THIS EVE IN RESPONSE TO PERSISTENT E-NE WINDS.
ANOMALIES CURRENTLY AROUND 0.5 FT ABOVE. LATEST CBOFS INDICATE
ANOMALIES INCREASE FURTHER THRU TUE MRNG...BUT SHOULD REMAIN BELOW
MINOR COASTAL FLOOD THRESHOLD.

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT TUESDAY FOR ANZ530>534-537-
539>541-543.
SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR ANZ535-
536-538-542.

$$
UPDATE...JRK
PREV DISC...JRK AND AMC/GAINES FROM WFO PHI

AREA FORECAST DISCUSSION

NWS RALEIGH NC

944 PM EDT MON APR 22 2013

.SYNOPSIS...
A DEVELOPING LOW PRESSURE SYSTEM EAST OF CAPE HATTERAS WILL TRACK
SLOWLY NORTHEAST OFFSHORE THE MID ATLANTIC AND NEW ENGLAND COAST
TUESDAY AND TUESDAY NIGHT. HIGH PRESSURE WILL PERSIST OVER CENTRAL
NORTH CAROLINA THROUGH WEDNESDAY...FOLLOWED BY A COLD FRONTAL
PASSAGE WEDNESDAY NIGHT.

.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 942 PM MONDAY...

TONIGHT...
SURFACE HIGH PRESSURE WILL CONTINUE TO EXTEND OVER CENTRAL NC FROM
THE CENTER LOCATED NE OF NOVA SCOTIA TONIGHT. MEANWHILE...SHOWERS ON
THE NORTHWEST SIDE OF A LOW PRESSURE SYSTEM DEVELOPING OFF THE NC
COAST HAVE PUSHED WESTWARD THIS EVENING. ALTHOUGH THE LIFT IS NOT
ALL THAT IMPRESSIVE IN THE MID LEVELS...THE NAM SHOWS AN AREA OF QG
FRONTOGENESIS AND SOME MID LEVEL DIVERGENCE OVER THE AREA WHERE
SHOWERS HAVE DEVELOPED. AS SUCH...THE NAM AND HRRR APPEAR TO HAVE
THE BEST HANDLE ON THE RAIN...SO HAVE INCREASED CHANCES ACCORDINGLY
TONIGHT. SCATTERED SHOWERS EXPECTED TO SPREAD WEST TOWARD THE TRIAD
THROUGH 12Z. STILL EXPECT WINDS TO STAY GUSTY OVERNIGHT AS THE
PRESSURE GRADIENT INCREASES OVER THE AREA. CLOUDS ALREADY EXTEND
ACROSS MOST OF THE FORECAST AREA...WITH TEMPS CURRENTLY HOLDING IN
THE 50S. STILL ANTICIPATE LOWS IN THE LOW TO MID 40S OVERNIGHT. -KC

TUESDAY AND TUESDAY NIGHT...
WITH THE SURFACE LOW MOVING NORTHEAST AWAY FROM THE AREA ON
TUESDAY...GUIDANCE INDICATES CLEARING FROM WEST TO EAST THROUGHOUT
THE DAY. GIVEN THE SHALLOW DEPTH OF SATURATION IN THE WEST...EXPECT
BREAKS IN CLOUD COVER WILL BE ABLE TO DEVELOP IN THE MORNING.
FURTHER EAST...FORECAST SOUNDINGS SHOW ABOUT A 3000FT LATER OF
STRATUS...WHICH WILL TAKE LONGER TO SCOUR VIA DRYING FROM ALOFT AND
HEATING. HOWEVER...MOST AREAS SHOULD BE PARTLY CLOUDY TO MOSTLY
SUNNY BY EARLY AFTERNOON....AND HIGHS WILL ACCORDINGLY BE WARMEST IN
THE SOUTH AND WEST IN THE MID TO UPPER 60S. THE RIDGE AXIS WILL THEN
SHIFT EAST ACROSS CENTRAL NC TUESDAY NIGHT...ALLOWING WINDS TO DIE
OFF AND FAVOR AT LEAST PATCHY FOG. LOWS IN THE UPPER 40S. -SMITH

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 235 PM MONDAY...

FOR WEDNESDAY: RISING SURFACE DEW POINTS WITHIN FAIRLY STABLE LOW
LEVELS... A DEPARTING SURFACE RIDGE... VERY LIGHT SURFACE FLOW FROM
THE SOUTHWEST... AND A LACK OF CLOUDS ALL SUPPORT AT LEAST PATCHY
FOG HOLDING INTO MID MORNING... ALTHOUGH WITH A BIT MORE MOISTURE
AND STRONGER LOW LEVEL FLOW IN THE TRIAD REGION... STRATUS MAY
DOMINATE HERE. AS THE WEAK SURFACE HIGH SHIFTS OFF THE SOUTHEAST
COAST WEDNESDAY... SOUTHWESTERLY FLOW FLOW WILL STRENGTHEN OVER
CENTRAL NC AHEAD OF THE COLD FRONT PROJECTED TO PUSH INTO WRN NC
EARLY-MID AFTERNOON. WE WILL STILL BE DOMINATED BY THE MID LEVEL
RIDGING AND DRY AIR HOWEVER... WITH A PROMINENT WARM NOSE AT 800-700
MB... SO INSTABILITY WILL BE LOW TO ABSENT AND MUCH OF THE DAY WILL
REMAIN DRY. THE EXCEPTION WILL BE THE TRIAD... WHICH SHOULD SEE A
FEW SHOWERS/STORMS MOVING IN VERY LATE IN THE AFTERNOON...
ACCOMPANYING THE RISING MID LEVEL LAPSE RATES TO OVER 6 C/KM AND THE
INCREASING LOW LEVEL MOISTURE TRANSPORT. BUT WITH THE MID LEVEL
VORTICITY SHEARING OFF QUICKLY NE ALONG THE APPALACHIANS ALONG WITH
THE MEAGER LOW LEVEL JET (JUST 20-25 KTS)... ANY PRECIP SHOULD BE
VERY LIGHT AND PATCHY. SREF PROBABILITIES OF MEASURABLE RAIN SUPPORT
THIS WITH ONLY LOW CHANCES GETTING INTO THE NW CWA TOWARD EVENING.
ABOVE-NORMAL THICKNESSES (PROJECTED TO CLIMB ABOVE 1380 METERS)
TEMPERED BY INCREASING HIGH CLOUDS THROUGH THE DAY AND SCATTERED
FLAT CUMULUS IN THE AFTERNOON SUPPORT HIGHS OF 74-80... VALUES ALSO
INDICATED BY THE DRY ADIABATIC LOW LEVEL THERMAL STRUCTURE.

FOR WEDNESDAY NIGHT/THURSDAY: AS THE MID LEVEL FLOW OVER OUR REGION
BECOMES ROUGHLY PARALLEL TO THE SURFACE FRONT... BETWEEN THE FIRST
SHORTWAVE TROUGH THAT SHEARS TO THE NORTHEAST TOWARD SE CANADA AND
THE SECOND SHOT OF SHORTWAVE ENERGY WHICH CROSSES THE UPPER MIDWEST
AND GREAT LAKES...THE SURFACE FRONT IS LIKELY TO MAKE ONLY A VERY
SLOW SOUTHEASTWARD PROGRESSION ACROSS NC WEDNESDAY NIGHT INTO EARLY
THURSDAY. GIVEN THE ANAFRONTAL STRUCTURE TO THIS SYSTEM... WE SHOULD
SEE RAIN AND A FEW STORMS SPREADING SLOWLY EAST WEDNESDAY NIGHT JUST
BEHIND THE FRONT. THE MID LEVEL VORTICITY AND LOW LEVEL JET BOTH
SHEARING OFF TO OUR NORTHEAST... ALONG WITH THE UPPER DIVERGENCE
MAX... WILL RESULT IN WANING DYNAMIC FORCING FOR ASCENT. BUT
STEEPENING MID LEVEL LAPSE RATES (TO OVER 6.25 C/KM) AND THE
POTENTIAL FOR ELEVATED CONVECTION (MUCAPE OF 100-200 J/KG) SHOULD
OFFSET THIS ENOUGH FOR CHANCE POPS... GIVEN THE ANTICIPATED CLIMB IN
PRECIP WATER VALUES TO AROUND 1.25 IN. WILL FOCUS THE HIGHEST POPS
LATE WEDNESDAY EVENING THROUGH EARLY THURSDAY MORNING OVER THE WRN
AND NRN PIEDMONT... BUT WILL LIMIT POPS TO JUST CHANCE. SREF
PROBABILITIES OF MEASURABLE RAIN START OFF NEAR 50% OVER THE
MOUNTAINS WEDNESDAY EVENING BUT FALL OFF QUICKLY WEDNESDAY NIGHT AS
THE FRONT SWEEPS EASTWARD... FURTHER SUPPORTING KEEPING POPS AND
AMOUNTS ON THE LOW END. PRECIP SHOULD TAPER OFF TO PATCHY DRIZZLE
LATE WEDNESDAY NIGHT (IN NW) THROUGH THURSDAY MORNING AS THE MID
LEVEL DRY OUT A BIT. AS THE MID LEVEL TROUGH MOVES THROUGH THE GREAT
LAKES INTO THE ST LAWRENCE VALLEY AND HELPS KICK THE SURFACE-850 MB
FRONTAL ZONE TO OUR SE THURSDAY AFTERNOON... MODEL FORECAST
SOUNDINGS SHOW ENOUGH DRYING JUST OFF THE SURFACE WITH AN INCREASING
DOWNSLOPE COMPONENT FOR SLOWLY CLEARING SKIES WEST-TO-EAST IN THE
AFTERNOON. HOWEVER.. CONFIDENCE IN SUCH CLEARING IS USUALLY REDUCED
IN THESE SITUATIONS WITH A MESOHIGH BEHIND AN ANAFRONT... AS THE
FLOW IS TYPICALLY TOO LIGHT AND VERTICAL MOTIONS TOO WEAK TO
DISPERSE THE RESIDUAL LOW LEVEL MOISTURE. AS A RESULT WILL BE MORE
PESSIMISTIC WITH CLOUD COVER THURSDAY... AND WILL HOLD ONTO THE
EARLIER FORECAST OF BELOW NORMAL TEMPS... ALTHOUGH A GREATER
DURATION OF LOW LEVEL DOWNSLOPE COMPONENT FLOW SHOULD YIELD SOME
AFTERNOON RECOVERY IN THE WRN FORECAST AREA... PLUS THE BRUNT OF THE
COOLER POST-FRONTAL AIR WILL BE SLOWED BY THE MOUNTAINS. MORNING
LOWS 50-58. HIGHS 64-72. -GIH

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 245 PM MONDAY...

FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT: THE MID LEVEL TROUGH AXIS
WILL PUSH TO OUR EAST THURSDAY NIGHT WITH THE COLD FRONT SLIPPING TO
OUR SOUTHEAST... AS A LARGE HIGH PRESSURE AREA BUILDS IN FROM THE
MISS VALLEY. EXPECT GRADUALLY CLEARING SKIES OVERNIGHT... ALTHOUGH
FORECAST SOUNDINGS SUGGEST THAT SHALLOW FOG BANKS ARE POSSIBLE.
PLEASANT AND DRY WEATHER AND SLIGHTLY BELOW-NORMAL TEMPS SHOULD
FOLLOW ON FRIDAY AS THE SURFACE HIGH RIDGES INTO NC WHILE ITS CENTER
CROSSES THE OHIO VALLEY HEADING TOWARD THE MIDATLANTIC REGION.
MODELS SHOW THE HIGH SHIFTING NE OFF THE MIDATLANTIC COAST TO NEW
ENGLAND FRIDAY NIGHT... PROPELLED BY ANOTHER SHORTWAVE TROUGH
CROSSING THE CENTRAL CONUS. THE ENSUING RETURN FLOW FROM THE
SOUTHEAST ALONG WITH INCREASING MID-HIGH LEVEL MOISTURE FROM THE WSW
SHOULD BRING AN INCREASE IN CLOUDS THROUGH FRIDAY NIGHT. TEMPS ABOUT
A CATEGORY BELOW NORMAL.

FOR SATURDAY THROUGH MONDAY: HIGH DEGREE OF FORECAST UNCERTAINTY AS
THE GFS/ECMWF BEGIN TO DIFFER CONSIDERABLY REGARDING THE CENTRAL US
TROUGH. BOTH INDICATE A POSITIVE TILT TO THE TROUGH ON SATURDAY...
BUT THE ECMWF EVOLVES INTO A SPLIT FLOW WITH A MORE AMPLIFIED AND
SLOWER WAVE THROUGH THE PLAINS COMPARED TO THE GFS. THE ECMWF THEN
DEVELOPS THIS INTO A CLOSED LOW TO OUR NORTH WITH A TROUGH COVERING
THE EASTERN CONUS SATURDAY NIGHT THROUGH MONDAY... WHILE THE GFS
TAKES THE WEAKER WAVE SWIFTLY OFFSHORE SUNDAY WITH MID LEVEL RIDGING
BUILDING OVER THE EASTERN CONUS BY MONDAY. RECENT GFS RUNS HAVE BEEN
TRENDING MORE AMPLIFIED AND SLOWER WITH THE WAVE... AND IT MAY BE
TOO EASILY KEEPING THE STREAMS PHASED... SO A LEAN TOWARD THE ECMWF
IS PREFERRED. THIS WILL MEAN A SLOWLY APPROACHING TROUGH FROM THE
WEST THROUGH MONDAY... RESULTING IN RAIN CHANCES FROM SATURDAY NIGHT
INTO MONDAY. THE OFFSHORE-DRIFTING SURFACE HIGH MAY DEPOSIT ENOUGH
COOL AIR IN THE PIEDMONT FOR AN IN SITU DAMMING EVENT. WILL LEAVE
TEMPS BELOW NORMAL THROUGH THE PERIOD... WITH SOME REBOUND IN TEMPS
MONDAY AS AN EDGE BACK TOWARD CLIMATOLOGY WITH A POSSIBLE WEAKENING
OF ANY WEDGE AIR MASS. -GIH

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 755 PM MONDAY...

WITH THE COASTAL LOW MOVING OFF TO THE NORTHEAST AND A HIGH COMING
IN BEHIND IT...A TIGHT GRADIENT TO THE WEST OF THE LOW IS IN PLACE
OVER CENTRAL NC...AND WINDS WILL BE MODERATE OVER THE AREA. VISIBLE
SATELLITE IMAGERY REVEALS SOME EROSION IN THE CLOUD FIELD ASSOCIATED
WITH THE COASTAL LOW AS THE FIELD MOVES WEST INTO THE CWA. FORECAST
SOUNDINGS ALSO SHOW LOW-LEVEL MOISTURE DECREASING TO THE WEST...SREF
PROBABILITIES FOR CIGS LESS THAN 1000FT ARE MORE FAVORABLE IN THE
EASTERN PORTIONS OF CENTRAL NORTH CAROLINA AND DECREASE TO THE WEST.
SITES IN THE WEST SHOULD NOT REACH IFR TONIGHT...FORECAST SOUNDINGS
FOR KRWI SUGGEST A TEMPORARY TRANSITION FROM MVFR TO IFR LATE
TONIGHT AND THEN EVENTUALLY BACK TO MVFR EARLY TUESDAY...OTHER SITES
LIKE KRDU AND KFAY EXPECTED TO REACH MVFR AND GET CLOSE TO IFR...
REMAINING THERE UNTIL LATER IN THE MORNING TUESDAY...THEN CONDITIONS
WILL IMPROVE BACK TO VFR.

OUTLOOK...
AN APPROACHING FRONTAL SYSTEM WILL BRING THE NEXT CHANCE FOR SUB-VFR
CONDITIONS WEDNESDAY NIGHT INTO THURSDAY. IMPROVING AVIATION
CONDITIONS AREA ANTICIPATED THURSDAY NIGHT INTO FRIDAY AS HIGH
PRESSURE BUILDS INTO THE REGION FROM THE NORTHWEST.

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

SYNOPSIS...BV
NEAR TERM...KC/SMITH
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...DJF/MKG/SMITH

AREA FORECAST DISCUSSION

NWS GRAND FORKS ND

1147 PM CDT SAT APR 20 2013

.UPDATE...
ISSUED AT 1146 PM CDT SAT APR 20 2013

RADAR RETURNS HAVE MOVED INTO THE RED RIVER VALLEY BUT THE TREND
OF NOTHING REACHING THE GROUND CONTINUES. THERE ARE A FEW REPORTS
JUST OFF OF OUR SOUTHEASTERN COUNTIES NEAR LAKE TRAVERSE...BUT NOT
MUCH ELSE UNTIL THE MONTANA/NORTH DAKOTA BORDER. CONTINUED THE
TREND OF SLOWING DOWN POPS WITH THE BETTER CHANCES FOR PRECIP
COMING IN WITH THE MAIN FRONT DURING THE DAY TOMORROW. SREF SHOWS
SOME PROBABILITIES OF FZRA IN THE SOUTHWESTERN COUNTIES LATE
TONIGHT...BUT THINK PRECIP CHANCES ARE LOW ENOUGH AT THAT POINT TO
KEEP THINGS SNOW THEN RAIN/SNOW LATER ON TOMORROW.

UPDATE ISSUED AT 935 PM CDT SAT APR 20 2013

LIGHT SNOW BAND MOVING INTO THE NORTHWESTERN COUNTIES HAS FALLEN
APART WITH NOT MUCH REACHING THE GROUND. NAM AND RUC HAVE BACKED
OFF ON QPF FROM THE FIRST WAVE OF WARM ADVECTION PRECIP AND NOW
HAVE MOST OF THE PRECIP COMING IN LATER ON TONIGHT/TOMORROW
MORNING WITH THE MAIN TROUGH. LOWERED POPS FOR THE REST OF THE
EVENING TO 20-30 PERCENT AND SAVED THE HIGHER POPS FOR THE EARLY
MORNING HOURS IN THE FAR NORTHWEST WHEN MAIN SYSTEM ARRIVES.
LOWERED QPF/SNOW FOR TONIGHT ALSO.

UPDATE ISSUED AT 642 PM CDT SAT APR 20 2013

ONLY A FEW MINOR TWEAKS FOR THIS UPDATE AS A BAND OF LIGHT SNOW
SLOWLY ENTERS THE FAR NORTHWESTERN CWA THIS EVENING. BAND IS
NARROW AND SHORT LIVED AND THINK THE MORE SIGNIFICANT PRECIP WILL
BE WHEN THE MAIN TROUGH AXIS/FRONTAL BOUNDARY COMES OUT TOMORROW
MORNING. BUT NOT CONFIDENT ENOUGH TO MAKE CHANGES TO POPS AFTER
MIDNIGHT SO WILL HOLD OFF UNTIL THE 00Z MODEL RUNS START COMING
IN. INCREASED CLOUDS A BIT TONIGHT AND TWEAKED TEMPS...BUT NO HUGE
CHANGES.

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 322 PM CDT SAT APR 20 2013

THE FORECAST CHALLENGE FOR THE SHORT TERM FOCUSES ON A COUPLE OF
ROUNDS OF SNOWFALL MOVING IN FROM THE WEST. IN GENERAL MODELS
STRUGGLE TO AGREE ON PLACEMENT OF PRECIPITATION...BUT COMPARING
CURRENT OBS/RADAR ECHOES TO 18Z VERIFICATION...I AM LEANING TOWARD
THE GFS. OPERATIONAL MODELS SHOW LOWERING CONDENSATION PRESSURE
DEFICITS MOVING IN TO WESTERN ZONES WITH MODEST ISENTROPIC LIFT
AFT 00Z...BY 06Z INTO THE RED RIVER VALLEY...AND ACROSS THE REGION
BY 12Z. BEFORE THIS MORE WIDESPREAD CLOUD COVER/PRECIP MOVES
IN...A TIGHT BAND OF SHOWERS WILL MOVE INTO THE WEST THIS EVENING.
DO EXPECT VERY LIGHT SNOW SHOWERS WITH THE INITIAL BAND...A BRIEF
BREAK...AND THEN MORE WIDESPREAD BUT LIGHT SNOW OVERNIGHT. PREFER A
SLIGHTLY LESS SATURATED GFS COMPARED TO THE NAM...AS ECHOES OVER
MONTANA HAVE NOT BEEN THAT IMPRESSIVE. BOTH MODELS ALSO SWEEP
PRECIP THROUGH RATHER QUICKLY AS ASSOCIATED FRONT MOVES INTO RED
RIVER VALLEY AROUND 18Z SUNDAY. DO EXPECT RAPID IMPROVEMENT AIDED
BY ISENTROPIC DESCENT TOMORROW AFTERNOON.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 322 PM CDT SAT APR 20 2013

ANOTHER WAVE WILL MOVE ACROSS THE CENTRAL PLAINS ON MONDAY...WITH
THE BEST CHANCE OF ANY MEASURABLE PRECIPITATION BEING ACROSS FAR
SOUTHERN ZONES. THE TUE NIGHT THROUGH SAT TIMEFRAME WILL CONTINUE WITH
TEMPS WELL BELOW NORMAL...WITH PERIODIC CHANCES FOR LIGHT QPF.
EACH MODEL RUN CONTINUES TO DELAY THE RIDGE ALOFT INTO THE
NORTHERN PLAINS...AND WARMER AIR...SO WILL HAVE TO SLIGHTLY LOWER
INHERITED TEMPS FOR ALL PERIODS. THE BEST CHANCES FOR PRECIP
APPEARS TO BE ON WED...WITH A RAIN/SNOW MIX CHANGING TO ALL SNOW
PERHAPS BY WED NIGHT. THE NW FLOW ALOFT AND PARADE OF SHORTWAVES
WILL CONTINUE WITH THE WARMEST DAY PERHAPS ON FRI/SAT...BUT
CONFIDENCE IS LOW WITH TEMPS LIKELY NOT GETTING TOO MUCH ABOVE THE
MID 40S AT ANY POINT. THERE ARE NO MAJOR PRECIP EVENTS IN SIGHT
EITHER...SO THE SLOW MELT CYCLE SHOULD CONTINUE.

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1146 PM CDT SAT APR 20 2013

VFR CEILINGS CONTINUE TO SPREAD ACROSS THE FORECAST AREA WITH MVFR
CIGS JUST TO OUR WEST. THINK THE LOWER CIGS WILL MOVE EASTWARD
AFTER 06Z TONIGHT INTO TOMORROW MORNING. SLOWED DOWN ANY PRECIP
MENTION AS MOST SNOW OR RAIN SHOULD BE WITH THE FRONTAL BOUNDARY
COMING IN DURING THE DAY TOMORROW. SOUTH WINDS WILL PICK UP TO
AROUND 15 KTS AND THEN SHIFT TO THE WEST AND NORTHWEST AS THE
FRONT COMES THROUGH. CIGS SHOULD RETURN TO VFR BY THE END OF
THE PERIOD.

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

UPDATE...JR
SHORT TERM...SPEICHER
LONG TERM...DK/SPEICHER
AVIATION...JR

AREA FORECAST DISCUSSION...UPDATED

NWS LUBBOCK TX

846 PM CDT MON APR 22 2013

.UPDATE...
COLD FRONT OF INTEREST IS RUNNING AHEAD OF SCHEDULE...BEING
REINFORCED BY A STRONGER SECONDARY SURGE...AS IT PUSHES THROUGH
THE SOUTHERN TEXAS PANHANDLE. FRONTAL ZONES RUNNING ROUGHLY FROM
VEGA TO AMARILLO THEN NORTHEAST TOWARD PAMPA AS OF 130Z. GIVEN THE
CURRENT MOTION OF THE FRONT...EXPECT IT INTO THE NORTHERN ZONES BY
2Z...WITH QUICK PROGRESS SOUTHWARD THEREAFTER. STRONG PRESSURE
GRADIENT AND INCREASINGLY STRONG PRESSURE RISES WILL KEEP THE
FRONT CHARGING SOUTH. NORTHERLY WINDS OF 30-40+ MPH WITH GUSTS
OVER 50 MPH ARE FAIRLY COMMON BEHIND THE FRONT...AND SEE NO REASON
THIS WILL NOT CONTINUE AS THE MUCH COLDER AIR SPREADS IN BEHIND
THE FROPA LATE THIS EVENING AND TONIGHT. THUS...HAVE GONE AHEAD
AND ISSUED A WIND ADVISORY FOR THE ENTIRE CWA...STARTING AT 2Z AND
CONTINUING THROUGH 12Z. THESE STRONG WINDS HAVE ALREADY LOFTED
PLENTY OF BLOWING DUST IN THE PANHANDLE...WITH MANY SITES AT LEAST
BRIEFLY REPORTING VISIBILITIES DROPPING TO AROUND 2SM.
HENCE...EXPECT A GOOD BIT OF DUST...WITH LOCALIZED NEAR BROWNOUT
CONDITIONS POSSIBLE...AS THE FRONT MOVES THROUGH. HAVE SPED UP THE
FROPA IN THE GRIDS WHILE ALSO RAISING THE FORECAST WINDS
SPEEDS/GUSTS TO BETTER MATCH CURRENT TRENDS. WINDS SHOULD
GRADUALLY WEAKEN TUESDAY MORNING AS THE PRESSURE GRADIENT SLOWLY
RELAXES. UPDATED PRODUCTS AND HAZARDS HAVE BEEN SENT.

.PREV DISCUSSION... /ISSUED 645 PM CDT MON APR 22 2013/

AVIATION...
MAIN AVIATION CONCERN THIS EVENING WILL BE COLD FRONT. INITIAL
WIND SHIFT CURRENTLY ABOUT 30NM N OF KAMA THOUGH SECONDARY SURGE
OF MUCH STRONGER WINDS HAS JUST COME THROUGH KGUY. AT SOME POINT
THIS EVENING...THE LATTER BOUNDARY IS EXPECTED TO OVERTAKE THE
INITIAL WIND SHIFT. SIGNIFICANT BLOWING DUST APPEARS EVIDENT ON
VISIBLE SATELLITE IMAGERY ALONG THE SECONDARY SURGE. GIVEN THAT
THE DUST IS GENERALLY LESS PRONOUNCED ON FRONTS SUCH AS THIS UP AT
CHILDRESS...HAVE INCLUDED MENTION OF DUST BUT KEEP VFR AT KCDS.
HERE IN KLBB...WITH THE DRY AND BARE SOILS...EXPECT MORE DENSE
DUST TO AT LEAST MVFR AND POSSIBLE INTO IFR TERRITORY. FROPA
TIMING IS BASED BY IN LARGE OF EXTRAPOLATED PROGRESSION WHICH IS
AHEAD OF MODEL GUIDANCE. GIVEN THE TIME OF DAY...AN EVEN EARLIER
ARRIVAL IS POSSIBLE. STAY TUNED FOR AMENDMENTS THIS EVENING.
FRONTAL AIRMASS IS QUITE SHALLOW AND FCST SOUNDINGS SUGGEST
SMOOTHER AIR OUT OF THE TURBULENT MIXING LAYER ABOVE 8-9 KFT.

PREV DISCUSSION... /ISSUED 341 PM CDT MON APR 22 2013/

SHORT TERM...
A STRONG COLD FRONT LOOKING TO BE A LITTLE AHEAD OF SCHEDULE HAVING
ALREADY NOSED INTO THE OKLAHOMA PANHANDLE AS OF 19Z...ALTHOUGH THE
COLD AIR LAGGING THE INITIAL WIND SHIFT BY ABOUT 150 TO 200 MILES.
MORNING RAP RUNS FASTEST WITH THE FRONT LOOK TO BE THE MODEL TO LEAN
TOWARD...AND POSSIBLY SLIGHTLY FASTER THAN THAT. WINDS WILL LIKELY
ACCELERATE TOWARD ADVISORY CRITERIA WITH PRESSURE RISES BEHIND IT...
ALTHOUGH FOR NOW WILL KEEP SPEEDS JUST BELOW THAT LEVEL. WILL RUN
WITH LOW TEMPS JUST BELOW LOW END OF MOS NUMBERS GIVEN STRENGTH OF
THE COLD AIR. THAT WOULD PUT POTENTIAL FOR A LIGHT FREEZE ACROSS THE
EXTREME SW PANHANDLE WHERE JUST NOW REACHING AVG DATE TO THE
BEGINNING OF THE GROWING SEASON. BETTER CANDIDATE FOR FREEZE PRODUCT
TO COME TUESDAY NIGHT WITH POTENTIAL FOR A HARD FREEZE. LOW CLOUDS
TO FILTER IN BEHIND THE FRONT. WHILE LOW CLOUDS PROGGED TO LIFT
TUESDAY MORNING...PERSISTENT MID LEVEL MOISTURE SHOULD KEEP SOME
CLOUD COVER OVER THE AREA. THAT COMBINED WITH LOW LEVEL COLD
ADVECTION THROUGH THE DAY WILL RESULT IN A DIURNAL RANGE OF 10 TO 15
DEGREES. OTHER ISSUE IS CHANCE FOR LIGHT PRECIP IN POST-FRONTAL AIR
MASS LATE TONIGHT AND EARLY TUESDAY. LOW LEVEL FRONTOGENESIS MAY BE
SUFFICIENT TO GENERATE SOME DRIZZLE OR VERY LIGHT RAIN ACROSS THE
NERN ZONES...BUT MEASURABLE PRECIP CHANCES LOOK VERY SLIM WITH BEST
LIFT ASSOCIATED WITH MID LEVEL TROUGH/JET REMAINING NORTH OF THE
FCST AREA. FINALLY...WHILE COLD FRONT WILL BE MOVING INTO AIR WITH
DEW POINTS IN THE 40S AND THUS SOME CAPE...CAP STRENGTH LOOKS TO BE
VERY STRONG WITH LITTLE POTENTIAL THAT ENERGY CAN BE RELEASED.

LONG TERM...
THE PRIMARY CONCERN FOR TUESDAY NIGHT AND WEDNESDAY MORNING WILL BE
THE POTENTIAL FOR A WIDESPREAD FREEZE ON THE HEELS OF THE PREVIOUS
NIGHTS FROPA. MODELS SEEM TO AGREE THAT H850 TEMPS WILL SETTLE
SOMEWHERE BETWEEN 0 TO -3 DEGREES... WITH THE NAM BEING THE COLD
OUTLIER OF THE BUNCH. IN ADDITION... A 1025-1030MB SURFACE RIDGE
WILL SLIDE JUST TO THE NE OF THE AREA OVERNIGHT...WHICH WILL KEEP
WINDS VERY LIGHT. ON THE OTHER HAND... SOME LINGERING JET ENERGY
AND MID-LEVEL MOISTURE COULD KEEP A BIT OF CLOUD COVER IN THE
AREA... INHIBITING RADIATIONAL COOLING IN SOME SPOTS... PARTICULARLY
IN THE EASTERN ZONES. REGARDLESS... CLOUD COVER SHOULD BREAK UP
BEFORE SUNRISE... AND TEMPERATURES ACROSS THE CAPROCK WILL LIKELY
FALL TO AROUND 4-8 DEGREES BELOW FREEZING BEFORE ALL IS SAID AND
DONE. TEMPERATURES WILL GRADUALLY RISE WEDNESDAY AND THURSDAY AHEAD
OF AN APPROACHING WAVE... WHICH WILL BE OUR NEXT ITEM OF CONCERN.

BY THURSDAY... A MEANDERING CLOSED LOW WILL WORK ITS WAY EASTWARD
FROM THE SUBTROPICAL PACIFIC BEFORE OPENING UP AND PHASING WITH A
BROAD CENTRAL CONUS TROUGH. BEFORE COMPLETELY BEING ABSORBED...
THIS WAVE WILL TRAVERSE THE TX PANHANDLE SOMETIME LATE THURSDAY
NIGHT... ALTHOUGH THERE IS STILL ABOUT 6 HOURS OF DISAGREEMENT
BETWEEN THE THE GFS AND ECMWF. AHEAD OF THIS WAVE... PRESSURE FALLS
ACROSS THE SOUTHERN FRONT RANGE WILL BEGIN TO FORCE SOUTHERLY FLOW
ACROSS TX...AND IN TURN ALLOW MODEST MOISTURE TO RETURN TO THE SOUTH
PLAINS AND EASTERN NM. DUE TO TUESDAYS COLD FRONT PINNING DEEP
MOISTURE WELL TO THE SOUTH... THE TIMING AND EXTENT OF THIS MOISTURE
RETURN IS IN QUESTION... AND AT THIS TIME IT APPEARS THAT THE BEST
MOISTURE WILL STRUGGLE TO ARRIVE UNTIL OVERNIGHT THURSDAY AND EVEN
EARLY FRIDAY MORNING. IN ADDITION... A STOUT CAP AND LOW-LEVEL
STRATUS WILL LIKELY ELIMINATE THE POSSIBILITY FOR AFTERNOON
THUNDERSTORM INITIATION EXCEPT FOR POSSIBLY ALONG THE
DRYLINE/PACIFIC FRONT IN EASTERN NM. AS THE WAVE PROGRESSES
EASTWARD... A PACIFIC FRONT WILL ALSO PUSH EASTWARD AND LIKELY
TRAVERSE THE AREA VERY LATE THURSDAY/EARLY FRIDAY...ALTHOUGH AGAIN
THE TIMING OF THIS FEATURE IS STILL SOMEWHAT IN QUESTION. AS THIS
FRONT MOVES EAST... IMPROVING MOISTURE ACROSS THE SOUTH PLAINS COULD
YIELD AT MARGINAL CHANCES FOR SHOWER/THUNDERSTORM
DEVELOPMENT...MOSTLY ACROSS THE NORTHERN ZONES WITH THE ADDED
FORCING FROM THE FRONT AND PASSING WAVE.

BEYOND FRIDAY MORNING... MODEL SOLUTIONS DIVERGE SIGNIFICANTLY...
ALTHOUGH THE GENERAL TREND WILL BE FOR BUILDING HEIGHTS AND WARMER
TEMPERATURES THROUGH THE END OF THE WEEK AND INTO THE
WEEKEND....FOLLOWING A BENIGN COLD FRONT FRIDAY NIGHT/SATURDAY
MORNING. MODELS ARE NOT IN AGREEMENT REGARDING THE ADVANCEMENT OF
THIS FRONT... AS THE ECMWF SENDS IT WELL SOUTH INTO THE TRANS PECOS
REGION WHILE THE GFS STALLS IT HALFWAY THROUGH THE LBB CWA. GIVEN
THE WEAKENING STATE OF THE PASSING WAVE AND LACK OF SIGNIFICANT COLD
ADVECTION... GFS SEEMS MORE REASONABLE HERE... ALTHOUGH CONVECTIVE
SIGNAL IN GFS FOR SUNDAY AFTERNOON SEEMS SUSPECT GIVEN THE ANEMIC
UPPER FLOW AND LACK OF FORCING. BOTH MODELS SEEM TO HINT AT A
SLOW-APPROACHING TROUGH/CLOSED LOW SOMETIME EARLY NEXT WEEK... BUT
AT THIS POINT SOLUTIONS ARE TOO FAR APART AND TOO FAR AWAY TO PUT
MUCH STOCK IN.

.PRELIMINARY POINT TEMPS/POPS...
FRIONA 30 45 25 59 36 / 10 10 10 0 10
TULIA 31 46 26 60 38 / 10 10 10 0 10
PLAINVIEW 32 48 27 60 38 / 10 10 10 0 10
LEVELLAND 35 50 28 60 38 / 10 10 10 0 10
LUBBOCK 36 50 30 60 39 / 10 10 10 0 10
DENVER CITY 39 54 26 61 33 / 10 10 10 0 10
BROWNFIELD 38 51 28 61 35 / 10 10 10 0 10
CHILDRESS 36 48 33 62 40 / 10 10 10 0 10
SPUR 39 49 32 61 44 / 10 10 10 0 10
ASPERMONT 43 50 33 62 43 / 10 10 10 0 10

.LUB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 AM CDT TUESDAY FOR THE FOLLOWING ZONES:
TXZ021>044.

26/23

AREA FORECAST DISCUSSION

NWS LUBBOCK TX

645 PM CDT MON APR 22 2013

.AVIATION...
MAIN AVIATION CONCERN THIS EVENING WILL BE COLD FRONT. INITIAL
WIND SHIFT CURRENTLY ABOUT 30NM N OF KAMA THOUGH SECONDARY SURGE
OF MUCH STRONGER WINDS HAS JUST COME THROUGH KGUY. AT SOME POINT
THIS EVENING...THE LATTER BOUNDARY IS EXPECTED TO OVERTAKE THE
INITIAL WIND SHIFT. SIGNIFICANT BLOWING DUST APPEARS EVIDENT ON
VISIBLE SATELLITE IMAGERY ALONG THE SECONDARY SURGE. GIVEN THAT
THE DUST IS GENERALLY LESS PRONOUNCED ON FRONTS SUCH AS THIS UP AT
CHILDRESS...HAVE INCLUDED MENTION OF DUST BUT KEEP VFR AT KCDS.
HERE IN KLBB...WITH THE DRY AND BARE SOILS...EXPECT MORE DENSE
DUST TO AT LEAST MVFR AND POSSIBLE INTO IFR TERRITORY. FROPA
TIMING IS BASED BY IN LARGE OF EXTRAPOLATED PROGRESSION WHICH IS
AHEAD OF MODEL GUIDANCE. GIVEN THE TIME OF DAY...AN EVEN EARLIER
ARRIVAL IS POSSIBLE. STAY TUNED FOR AMENDMENTS THIS EVENING.
FRONTAL AIRMASS IS QUITE SHALLOW AND FCST SOUNDINGS SUGGEST
SMOOTHER AIR OUT OF THE TURBULENT MIXING LAYER ABOVE 8-9 KFT.

.PREV DISCUSSION... /ISSUED 341 PM CDT MON APR 22 2013/

.PRELIMINARY POINT TEMPS/POPS...
FRIONA 86 30 45 25 59 / 0 10 10 10 0
TULIA 88 31 46 26 60 / 0 10 10 10 0
PLAINVIEW 87 32 48 27 60 / 0 10 10 10 0
LEVELLAND 89 35 50 28 60 / 0 10 10 10 0
LUBBOCK 90 35 50 30 60 / 0 10 10 10 0
DENVER CITY 90 39 54 26 61 / 0 10 10 10 0
BROWNFIELD 90 38 51 28 61 / 0 10 10 10 0
CHILDRESS 89 36 48 33 62 / 10 10 10 10 0
SPUR 90 39 49 32 61 / 0 10 10 10 0
ASPERMONT 90 43 50 33 62 / 0 10 10 10 0

.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

99/99/26

AREA FORECAST DISCUSSION

NWS MILWAUKEE/SULLIVAN WI

902 PM CDT MON APR 22 2013

.UPDATE...
THE PREVIOUS DISCUSSION POINTED OUT THAT THE 18Z RUN OF THE NAM
WAS TRENDING MUCH LOWERING ON RAIN AMOUNTS ASSOCIATED WITH THE
FIRST WAVE OF PRECIP HEADING INTO SOUTHERN WISCONSIN TONIGHT. THE
LATEST HRRR IS EVEN MORE BULLISH IN LOWER QPF. IT SUGGESTS MANY
AREAS COULD MISS OUT ALTOGETHER ON THE RAIN TONIGHT. THE NEW 00Z
NAM COMING IN CONTINUES THE DRIER LOOK. THE BEST Q-VECTOR
CONVERGENCE IS HEADING NORTH OF THE AREA OVERNIGHT. THE SURFACE
LOW CURRENTLY OVER NORTHEAST IOWA...HEADS TO GREEN BAY BY 12Z
TUESDAY WITH JUST THE TRAILING COLD FRONT DRIFTING IN. THE AIR
AHEAD OF THIS FRONT IS DRIER THAN WHAT THE MODELS THINK...THUS
MUCH OF THE RAIN WILL BE CHEWED UP IN EVAPORATION. I/LL ADJUST
POPS LOWER AT THIS POINT AND KEEP INTENSITY LIGHT. THIS IS GOOD
NEWS FOR OUR SOAKED SOILS AND OVERFLOWING RIVERS.

THE SECOND WAVE OF PRECIP WILL BE ON TUESDAY AS A STRONG UPPER
SHORTWAVE PUSHES IN...GENERATING SOME SURFACE CYCLOGENESIS ALONG
THE COLD FRONT. THE BULK OF THAT RAIN WOULD BE ACROSS THE
SOUTHEAST CLOSER TO THE FRONT.

.AVIATION/06Z TAFS/...

VFR CONDITIONS WILL LOWER TO MVFR CIGS/VSBYS AROUND 12Z TUESDAY.
LOW PRESSURE OVER NORTHEAST IOWA WILL TRACK TO THE VICINITY OF
GREEN BAY BY 12Z TUESDAY. A TRAILING COLD FRONT WILL SWEEP THROUGH
BETWEEN 12-16Z TUESDAY. CIGS WILL LOWER TO MVFR AND POSSIBLY IFR
ALONG AND BEHIND THE FRONT. SHOWERS WILL BE ERODING AS THE WORK
INTO THE AREA TONIGHT. JUST LIGHT RAIN EXPECTED. A SECONDARY SURGE
OF RAIN AND LOWER CIGS/VSBYS ARRIVES TUESDAY AFTERNOON...MAINLY
ACROSS KMKE/KENW/KUES. DRIER AIR ON NORTHWEST WINDS WILL BRING
SLIGHTLY BETTER CIGS/VSBYS TO MADISON TUESDAY AFTERNOON.

.PREV DISCUSSION... /ISSUED 336 PM CDT MON APR 22 2013/

VERY SHORT TERM...TONIGHT AND TUESDAY.

AFTER A QUIET EVENING...LIGHT RAIN SHOWERS ARE EXPECTED TO SPREAD
INTO SOUTHERN WI JUST AFTER MIDNIGHT AND REACH SHEBOYGAN AREA AROUND
5 AM. THESE WILL BE SUPPORTED BY THE LEFT EXIT REGION OF A 110KT
UPPER JET PUSHING INTO THE REGION...ALONG WITH WEAK 500MB SHORTWAVE
AND 700MB NEGATIVE OMEGA. THE NAM IS SHOWING SOME SEPARATION BETWEEN
THIS INITIAL ROUND OF SHOWERS AND THE NEXT ONE...AND THE 18Z RUN
ACTUALLY LOWERED THE QPF AND SPATIAL COVERAGE IN SOUTHEAST WI BY A
LOT. SOME OF THE MESOSCALE MODELS PLAY DOWN THAT INITIAL SURGE AS
WELL.

THE NEXT SHORTWAVE MOVING INTO SOUTHERN WI WILL BRING A BETTER
CHANCE FOR WIDESPREAD SHOWERS OUT AHEAD OF THE APPROACHING
SLOW-MOVING COLD FRONT. THIS WILL GET INTO SOUTH CENTRAL WI APPROX
09Z AND SPREAD NORTHEAST INTO THE MID MORNING HOURS.

MODELS ARE NOW SHOWING THE COLD FRONT TO MOVE ACROSS SOUTHEAST WI A
LITTLE QUICKER...WITH PRECIP OUT OF MADISON AREA BY 18Z AND FAR
SOUTHEAST WI AROUND 00Z. THEREFORE...LOWERED AFTERNOON
POPS...ESPECIALLY IN NW FORECAST AREA.

Q-VECTOR CONVERGENCE AND NEGATIVE EPV COMBINED SHOW STRONG POSITIVE
VALUES MOVING INTO SOUTHEAST WI LATE TONIGHT/EARLY TUESDAY. THIS
WITH THE STRONG OMEGA AND UPPER DIVERGENCE COULD LEAD TO SOME
EMBEDDED THUNDER IN SOUTHEAST WI...SO ADDED SLIGHT CHANCE OF THUNDER
INTO THE FCST FOR A SHORT PERIOD OF TIME THERE.

PRECIPITABLE WATER VALUES OF AROUND 0.80 ARE EXPECTED...WITH TOTAL
RAINFALL AMOUNTS OF ABOUT A HALF INCH POSSIBLE IN THE
SOUTHEAST...WITH LIGHTER AMOUNTS TOWARD CENTRAL WI.

SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY.

MAIN SHORT TERM GUIDANCE SHOWING QUICKER EASTWARD PROGRESSION OF MID
LEVEL SHORT WAVE TROUGH AND SFC FRONT ACROSS WESTERN GREAT LAKES
LATER TUESDAY AND TUESDAY NIGHT. NORTHWEST WINDS IN THE WAVE OF THE
TROUGH PULL DRIER BACK INTO SOUTHERN WI RAPIDLY DURING THE EVENING.
HENCE TRIMMED POPS BACK SLIGHTLY TO MAINLY CHANCE LEVELS TUESDAY
EVENING IN THE EAST. FASTER EWD PROGRESSION AND RETURN OF DRIER AIR
ALSO CUTS BACK ON -SN POTENTIAL AS PRECIP WANES DURING THE EVENING.

SHORT WAVE RIDGING BETWEEN DEPARTING SHORT WAVE TROUGH AND NEXT
STRONGER WAVE SHOULD RESULT IN A DRY AND COOL DAY ON WEDNESDAY
ACROSS SOUTHERN WI. SUNSHINE SHOULD GIVE WAY TO A RAPID INCREASE IN
CLOUDS DURING THE AFT AND EVE. STILL IMPRESSED BY THE STRENGTH OF
THE NEXT FAST-MOVING SHORT WAVE THAT SWEEPS ACROSS WI LATE WED AND
WED NGT. IMPRESSIVE SLUG OF 400 POTENTIAL VORTICITY ASSOCIATED WITH
SHORT WAVE. 700-500MB LAPSE RATES INCREASE TO 7.5 TO 8 DEGREES
DURING THIS PERIOD ALLOWING FOR ENHANCED FORCING. HENCE EXPECTING A
SWATH OF MODERATE RAIN AND SNOW SHOWERS TO RAPIDLY SWEEP ACROSS MUCH
OF SRN WI BETWEEN 01Z AND 08Z. THE SNOW SHOWERS MAY LEAVE A LIGHT
COATING OF SNOW ON THE GRASS. DRY AND COOL CONDITIONS RETURN FOR
THURSDAY

LONG TERM...THURSDAY NIGHT THROUGH MONDAY.

WARMER TEMPERATURES SHOULD DEVELOP ON FRIDAY AND CONTINUE THROUGH
THE PERIOD. 85H TEMPERATURES WARM TO 5 TO 10C ON FRIDAY...CARRIED
INTO THE AREA BY DRY SOUTHWEST BREEZES. FOR NOW WILL CONTINUE TO
FOLLOW DRIER ECMWF AND ECMWF ENSEMBLE AS THEY ARE SHOWING THE MOST
CONSISTENCY W.R.T. SPLIT FLOW DEVELOPING OVER CONUS ON FRIDAY AND
PERSISTING THROUGH THE WEEKEND. LAST SEVERAL RUNS OF THE GFS HAVE
BEEN TRENDING TOWARD MORE PHASING OF NORTHERN AND SOUTHERN STREAMS
ON FRIDAY AND SATURDAY...AND BRINGING THE EFFECTS OF PASSING LOW
PRESSURE TROUGH AND LIGHT RAIN TO THE AREA. HOWEVER GFS SOLUTION
REMAINS AN OUTLIER...WHILE DGEX AND GEM SHOW PERSISTENT DRIER ZONAL
FLOW REMAINING OVER UPPER MIDWEST. UNCERTAINTY REMAINS HOWEVER AS
UKMO ALSO IN CAMP WITH GFS AND ENSEMBLES SHOWING CONSIDERABLE
VARIABILITY IN INDIVIDUAL MEMBERS OVER THE WEEKEND. HENCE FOR
NOW...WILL BE HANGING ONTO SOME SMALL POPS FRIDAY THRU SAT. HOWEVER
NO ALL DAY WASHOUTS ARE EXPECTED SO MORE TYPICAL OUTDOOR SPRING
ACTIVITIES WILL BE ABLE TO TAKE PLACE.

5 DAY 500H MEANS BASED ON GFS STILL ON TARGET IN SHOWING CURRENT
LARGE NEGATIVE ANOMOLY SUCCUMBING TO COLLAPSING UPSTREAM RIDGING
OVER EASTERN PACIFIC. THIS ALLOWS MORE ZONAL FLOW TO DEVELOP FOR
THE WEEKEND AS 500H 5 DAY MEANS FINALLY REACH ABOVE NORMAL LEVELS BY
THE END OF APRIL.

AVIATION /00Z TAFS/...

RAIN SHOWERS WILL SPREAD INTO SOUTH CENTRAL AND SOUTHEAST AND
EVENTUALLY EAST CENTRAL WI LATE TONIGHT INTO TUESDAY MORNING...AHEAD
OF A SLOW-MOVING COLD FRONT. RAIN MAY BECOME MODERATE AT TIMES. THE
FRONT AND RAIN ARE EXPECTED TO CLEAR MADISON BY 18Z...AND FAR
SOUTHEAST WI AROUND 00Z. AREAS OF MVFR CIGS AND VSBYS ARE EXPECTED
WITH THE RAIN AND COLD FRONTAL PASSAGE.

MARINE...

NORTHWEST WIND GUSTS WILL APPROACH SMALL CRAFT CONDITIONS FOR A
SHORT PERIOD OF TIME JUST BEHIND A PASSING COLD FRONT TUESDAY
AFTERNOON AND EVENING.

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

UPDATE...DAVIS
TONIGHT/TUESDAY AND AVIATION/MARINE...MRC
TUESDAY NIGHT THROUGH MONDAY...MBK

AREA FORECAST DISCUSSION

NWS LA CROSSE WI

852 PM CDT MON APR 22 2013

.UPDATE...
ISSUED AT 852 PM CDT MON APR 22 2013

A SURFACE LOW PRESSURE SYSTEM CURRENTLY ANALYZED IN NORTHEAST IOWA
JUST TO THE SOUTHWEST OF DECORAH IOWA WILL CONTINUE TO TRACK TO
THE EAST NORTHEAST ALONG A WARM FRONT THAT EXTENDS EAST OF THIS
LOW THROUGH CENTRAL WISCONSIN. THE MAIN FOCUS WITH THE NEAR TERM
FORECAST IS WITH WHEN/WHERE THE CHANGE OVER TO SNOW WILL TAKE
PLACE. THE WARM LAYER IS AT 850MB WITH THE 0C ISOTHERM RUNNING
ALONG THE FORECAST AREA BOUNDARY BETWEEN US AND MPX WHICH RUNS
ACROSS SOUTHEAST MINNESOTA NORTHEAST INTO NORTH CENTRAL WISCONSIN.
TO THE SOUTHEAST OF THE 0C 850MB ISOTHERM...PRECIPITATION IS
FALLING ALL AS RAIN WITH TEMPERATURES WELL ABOVE FREEZING. ALONG
THIS ISOTHERM...PRECIPITATION QUICKLY CHANGES FROM RAIN TO SLEET
TO SNOW. BRIGHT BANDING ON THE 0.5DEG KARX REFL/CC SHOWS THIS
MELTING LAYER AND IT LOOKS LIKE THE CHANGE OVER HAPPENS RIGHT
ALONG AND NORTHWEST OF THIS BAND. LOOKING FURTHER WEST...THE BACK
EDGE OF THE SNOW IN SOUTH CENTRAL MINNESOTA IS MAKING SOME QUICK
PROGRESS EASTWARD AS WELL AND IS TRENDING FASTER THAN WHAT THE
PREVIOUS MODELS HAD ADVERTISED. THE 22.23Z HRRR HAS LATCHED ONTO
THIS IDEA AS WELL AND HAVE USED AN EXTRAPOLATION/HRRR BLEND TO TRY
AND TIME DOWN THE PROGRESS EASTWARD OVERNIGHT. THE MAIN
COUNTY/AREA OF CONCERN FOR SNOW ACCUMULATION APPEARS TO BE IN
DODGE COUNTY MINNESOTA BETWEEN NOW AND 6Z TONIGHT. 22.23Z RAP
SOUNDINGS ALSO SHOW A QUICK LOSS OF ICE IN THE PROFILE AS THE BACK
EDGE MOVES THROUGH WHICH MEANS THAT DRIZZLE/FREEZING DRIZZLE WILL
BE POSSIBLE IF THERE IS ANY LOW LEVEL FORCING LEFT BEHIND THIS
SYSTEM.

THE QUESTION THEN BECOMES WITH SURFACE TEMPERATURES AND WHETHER IT
WILL COOL DOWN TO FREEZING OR NOT OVERNIGHT. TEMPERATURES ARE
MAINLY AT OR ABOVE FREEZING THROUGH MUCH OF THE REGION WITH NOT
MUCH IN THE WAY OF INITIAL COLD AIR ADVECTION COMING IN OVERNIGHT.
THE 32F SURFACE ISOTHERM IS JUST OFF TO THE NORTHWEST...SO WILL
HAVE TO WATCH THAT OVERNIGHT AND IF THE DRIZZLE DOES FORM AS WELL
WHICH COULD CREATE SOME SLICK CONDITIONS.

WILL NOT BE MAKING ANY CHANGES TO THE GOING HEADLINES RIGHT NOW.
AS MENTIONED...DODGE COUNTY WOULD BE THE MAIN CONCERN FOR HIGHEST
SNOWFALL TOTALS AT AN INCH...MAYBE TWO...BUT THE SNOW WILL LIKELY
ONLY OCCUR FOR A FEW HOURS THIS EVENING BEFORE THE FRONTOGENESIS
SHIFTS NORTHEAST. NOT VERY CONFIDENT THAT TAYLOR COUNTY WILL GET
MUCH SNOW...BUT PHILLIPS HAS BEEN REPORTING SNOW FOR THE PAST
COUPLE HOURS AND THEY COULD STILL SEE SOME SNOW IN THE NORTHWEST
PART OF THE COUNTY.

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 347 PM CDT MON APR 22 2013

POSITIVITY TILTED UPPER LEVEL TROUGH MOVING THROUGH WITH A FEW
EMBEDDED SHORTWAVES NOTED THAT WILL IMPACT THE REGION TONIGHT AND
TUESDAY...ONE ACROSS THE NORTHERN PLAINS...AND A SECOND ROTATING
THROUGH THE INTERMOUNTAIN WEST. AT THE SURFACE...MAIN AREA OF LOW
PRESSURE IS SITUATED IN SOUTHWESTERN KANSAS...WITH A SECONDARY LOW
DEVELOPING NEAR KANSAS CITY. A WARM FRONTAL BOUNDARY EXTENDS
NORTHEAST TO NEAR DES MONIES...LA CROSSE...AND WAUSAU. DEFORMATION
BANDING PRECIPITATION IS DEVELOPING ALONG AND NORTH OF THE
FRONT...LIFTING THROUGH THE AREA THIS AFTERNOON.

NEAR-TERM GUIDANCE AND MESO-MODEL SOLUTIONS IN GOOD AGREEMENT
SHOWING LOW PRESSURE RIDING ALONG THIS BOUNDARY TONIGHT...CENTERING
NEAR LA CROSSE BY 06Z. STRONG FRONTOGENETICAL FORCING ON THE
NORTHWEST SIDE WILL KEEP DEFORMATION BAND PRECIPITATION IN PLACE
ACROSS SOUTHERN MINNESOTA INTO PARTS OF WESTERN WISCONSIN.
BIGGEST FORECAST CONCERN REMAINS ON WHEN PRECIPITATION WILL
TRANSITION FROM RAIN TO A RAIN/SNOW MIX...THEN TO ALL SNOW...AND
WHAT SNOWFALL ACCUMULATIONS RESULT. 22.12Z PROBABILISTIC AND
DETERMINISTIC GUIDANCE DID NOT VARY TOO MUCH FROM PREVIOUS
RUNS...AND STILL POINT TO SOUTHERN INTO CENTRAL MINNESOTA...AND
THEN INTO NORTHWEST WISCONSIN WITH THE HIGHER THREAT OF
ACCUMULATING SNOW. LOCALLY...THE MOST CONCERN IS FOR EXTREME
NORTHWEST DODGE/WABASHA COUNTIES IN MINNESOTA...AND TAYLOR COUNTY
IN WISCONSIN WHERE 1 TO 2 INCHES ARE POSSIBLE. THIS CHANGE OVER IS
EXPECTED AROUND MIDNIGHT OR SO...SLOWLY WORKING EAST DURING THE
OVERNIGHT.

CROSS SECTIONS THROUGH SOUTHEAST MINNESOTA SHOW STRONG SLOPING
FRONTOGENETIC SIGNAL WITH NEGATIVE EPV ABOVE...SO CONVECTIVE ELEMENTS
ARE POSSIBLE. THIS WOULD ENHANCE PRECIPITATION RATES...AND ALLOW
DYNAMIC COOLING TO WIN OUT. END RESULT...THERE COULD BE QUICK
BURSTS OF SNOW IN THESE AREAS AND THIS WILL BE SOMETHING TO WATCH
CLOSELY TONIGHT. RIGHT NOW THE HIGHER THREAT IS JUST OFF TO THE
NORTHWEST.

SOUNDINGS SHOW THE ATMOSPHERE LOSES ICE SATURATION OVERNIGHT AS
SURFACE TEMPERATURES COOL TO NEAR FREEZING. COMBINED WITH A
RETREATING WARM NOSE AT 850 MB....THERE IS A BRIEF FREEZING RAIN
OR FREEZING DRIZZLE THREAT ACROSS PORTIONS OF SOUTHEAST MINNESOTA
INTO NORTH CENTRAL WISCONSIN. 22.09Z SREF PROBABILITIES DEPICT A
10 TO 30 PERCENT PROBABILITY AS WELL. HAVE INCREASED THIS SOME
FROM PREVIOUS FORECAST...AND A VERY MINOR GLAZE IS POSSIBLE.

FOR TUESDAY...THE SURFACE LOW IS EXPECTED TO LIFT INTO THE GREAT
LAKES AND THERE SHOULD BE A QUICK WEST TO EAST END TO PRECIPITATION
IN THE MORNING HOURS. PLAN ON BLUSTERY NORTHWEST WINDS 10 TO 20
MPH...WITH HIGHER GUSTS UP TO 30 MPH. SKIES WILL CLEAR DURING THE
AFTERNOON AS DRIER AIR WORKS IN ACROSS THE AREA ALONG WITH SURFACE
HIGH PRESSURE BUILDING IN. FINALLY...TEMPERATURES WILL BE NEARLY 20
DEGREES BELOW NORMAL..WITH LOWER 40S COMMON ACROSS THE AREA.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 347 PM CDT MON APR 22 2013

FOCUS IN THE LONG TERM IS ON A RATHER VIGOROUS NORTHERN STREAM
SHORTWAVE FOR WED/WED NIGHT...THEN LOOKING FORWARD TO THE
MUCH-ANTICIPATED FIRST SPRING WARM UP THAT IS POSSIBLE THIS WEEKEND.

FOR WEDNESDAY A POTENT SHORTWAVE TROUGH IS EXPECTED TO QUICKLY DIVE
OUT OF THE NORTHERN PLAINS IN THE AFTERNOON AND EVENING HOURS. THIS
SYSTEM IS CHARACTERIZED BY VERY STEEP LOW-LEVEL LAPSE RATES THANKS
TO AN ANOMALOUSLY COLD MID/UPPER LEVEL CORE. 500 MB STANDARDIZED
ANOMALIES OFF THE 22.00Z ECMWF VARY FROM 2 TO 2.5 SD BELOW NORMAL.
ALTHOUGH MOISTURE CONVERGENCE IS LACKING...THE MID/UPPER LEVEL
DYNAMICS LOOK TO BE SUFFICIENT ENOUGH TO WARRANT HIGHER
PRECIPITATION CHANCES. THERE REMAINS SOME TIMING DIFFERENCE BETWEEN
22.12 GUIDANCE...AND THE LATER ARRIVAL WOULD POINT TOWARD MORE A
RAIN/SNOW MIX. LOCATIONS NORTH OF I-94 COULD PICK UP A 1/2 INCH OF
SNOW LATE WEDNESDAY NIGHT AS COOLING CHANGES RAIN OVER TO WET SNOW.

THE LATE WEEK INTO THE UPCOMING WEEKEND FEATURES RETURN SOUTHWESTERLY
FLOW AS THE UPPER LEVEL FLOW RIDGING TAKES SHAPE. 850 MB
TEMPERATURES RISE FROM AROUND -5C ON THURSDAY...TO AS HIGH AS +10 TO
+14C BY SUNDAY. HIGHS FRIDAY/SATURDAY WILL RISE INTO THE 60S...WITH
LOW 70S POSSIBLE SUNDAY/MONDAY. DESPITE WARM TEMPERATURES...A
LINGERING BOUNDARY TO THE NORTH WARRANTS SLIGHT CHANCES NORTH OF
I-90 SATURDAY NIGHT INTO SUNDAY. THIS WILL BE WELCOME NEWS TO THOSE
WHO ARE LOOKING FORWARD TO SOME SPRING WEATHER...HOWEVER THIS COULD
POTENTIALLY CREATE HYDROLOGY ISSUES...SO SEE HYDROLOGY SECTION FOR
MORE DETAILS.

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 650 PM CDT MON APR 22 2013

LOW FLIGHT CONDITIONS TO OCCUR OVER AT LEAST THE NEXT 12 HOURS AS
A LOW PRESSURE SYSTEM MOVES INTO THE REGION. A WARM FRONT HAS SET
UP ACROSS SOUTHEAST MINNESOTA INTO CENTRAL WISCONSIN WITH LIFR TO
MVFR CONDITIONS REPORTED ALONG IT. THE MAIN INITIAL BAND OF RAIN
HAS SHIFTED TO THE NORTH...BUT DRIZZLE AND SOME SHOWERS WILL OCCUR
BEFORE THE MAIN BAND MOVES IN THIS EVENING AHEAD OF THE LOW. THERE
IS A SMALL CHANCE THAT THE RAIN WILL CHANGE OVER TO SNOW FOR A FEW
HOURS IN RST AS THE TAIL END OF THE SYSTEM SWINGS THROUGH...BUT AM
NOT VERY CONFIDENT THAT THIS WILL OCCUR. AFTER THE LOW MOVES
THROUGH...THERE COULD BE A BRIEF PERIOD OF DRIZZLE OR FREEZING
DRIZZLE...DEPENDING ON SURFACE TEMPERATURES...BETWEEN 6-12Z.
CONDITIONS WILL GRADUALLY IMPROVE INTO TUESDAY THOUGH WINDS WILL
BE FAIRLY GUSTY AT AROUND 25KT OVERNIGHT INTO TOMORROW.

.HYDROLOGY...TONIGHT/TUESDAY
ISSUED AT 347 PM CDT MON APR 22 2013

THE TONIGHT/TUESDAY EVENT IS EXPECTED TO RESULT IN 0.5 TO UP 1.0
INCH OF LIQUID ACROSS PORTIONS OF SOUTHEAST MINNESOTA AND WESTERN
INTO CENTRAL WISCONSIN. SATURATED GROUND FROM THE RECENT
RAINFALL...ALONG WITH SNOWPACK REMAINING IN PLACE ACROSS CENTRAL
MINNESOTA INTO NORTH CENTRAL WISCONSIN WILL KEEP AN ELEVATED RISK
OF HYDROLOGY ISSUES. FORECAST RAINFALL AMOUNTS BRING THE
TREMPEALEAU RIVER AT DODGE POTENTIALLY ABOVE FLOOD STAGE LATER
THIS WEEK BUT GIVEN SOME UNCERTAINTY IN WHAT BASINS WILL EXPERIENCE
THE HIGHER AMOUNTS...AT THIS TIME A FLOOD WATCH WAS POSTED.

LOOKING AHEAD...THE POSSIBLE SIGNIFICANT WARM UP ACROSS THE UPPER
MIDWEST THIS WEEKEND INTO EARLY NEXT WEEK COULD LEAD TO RAPID
SNOWMELT ACROSS CENTRAL MINNESOTA AND THE NORTHERN HALF OF
WISCONSIN. THIS WOULD LEAD TO SIGNIFICANT RISES ON AREA
TRIBUTARIES SUCH AS THE BLACK AND TREMPEALEAU RIVER...AND
EVENTUALLY ON THE MAIN STEM OF THE MISSISSIPPI RIVER. CURRENT
FORECASTS SHOW 1 TO 2 FEET RISES ON THE MISSISSIPPI BY THIS
WEEKEND...ABOVE ACTION STAGE AT MANY SITES.

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 9 AM CDT TUESDAY FOR WIZ017.

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

UPDATE...HALBACH
SHORT TERM...ZT
LONG TERM...ZT
AVIATION...HALBACH
HYDROLOGY...ZT

AREA FORECAST DISCUSSION

NWS COLUMBIA SC

347 AM EDT TUE APR 23 2013

.SYNOPSIS...
A PRESSURE RIDGE WILL EXTEND THROUGH THE FORECAST AREA THROUGH
TONIGHT. A COLD FRONT WILL APPROACH FROM THE WEST WEDNESDAY. THE
WEAKENING FRONT WILL MOVE THROUGH THE AREA WEDNESDAY NIGHT AND
EARLY THURSDAY.

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL CONTINUE TO RIDGE INTO THE FORECAST AREA FROM
THE NORTH TODAY. CLOUDINESS ASSOCIATED WITH THE OFFSHORE FRONT
WAS AFFECTING THE NORTHEAST PART OF THE FORECAST AREA EARLY THIS
MORNING. THE LATEST RAP SHOWS HIGH LOW-LEVEL MOISTURE CONTINUING
IN THE NORTHEAST PART THROUGH 15Z. EXPECT THIS CLOUDINESS WILL
DIMINISH LATER THIS MORNING OR EARLY THIS AFTERNOON AS THE FRONT
SHIFTS FARTHER OFFSHORE. HEATING AND MIXING SHOULD ALSO RESULT IN
LESS CLOUDINESS. THE TEMPERATURE GUIDANCE WAS CLOSE. THE GUIDANCE
MAY BE A LITTLE TOO WARM IN THE NORTHEAST PART BECAUSE OF
LINGERING CLOUDINESS.

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
THE RIDGE WILL REMAIN NEAR THE FORECAST AREA TROUGH TONIGHT.
EXPECT STRONG NET RADIATIONAL COOLING WHICH MAY LEAD TO AREAS OF
FOG DURING THE EARLY MORNING HOURS. WARMING WILL OCCUR AHEAD OF
THE APPROACHING COLD FRONT WEDNESDAY. THE WARM TEMPERATURE
GUIDANCE IS USUALLY BETTER JUST AHEAD OF A COLD FRONT. THE NAM
AND GFS AGREE KEEPING THE FORCING AND DEEPER MOISTURE WEST OF THE
FORECAST AREA AND EXPECT IT WILL REMAIN DRY WEDNESDAY. THE NAM AND
GFS SHOW THE FRONT MOVING INTO THE AREA WEDNESDAY NIGHT WITH
DIMINISHING MOISTURE. THE GUIDANCE CONSENSUS SUPPORTS CHANCE POPS.
THE NAM AND GFS INDICATE DRYING BEHIND THE FRONT THURSDAY.
HOWEVER...THE ECMWF HAD A SLOWER TIMING SO WE MAINTAINED A SMALL
POP THURSDAY. DRY RIDGING BEHIND THE FRONT SHOULD BE DOMINATE
THURSDAY NIGHT.

.LONG TERM /FRIDAY THROUGH MONDAY/...
THE DRY RIDGING SHOULD REMAIN IN CONTROL THROUGH FRIDAY. AN
ONSHORE FLOW AND ANOTHER FRONT IN THE AREA SUPPORTS A CHANCE OF
SHOWERS AND THUNDERSTORMS DURING THE REST OF THE MEDIUM-RANGE
PERIOD. THE GFS AND ECMWF MOS SUPPORT CHANCE POPS.

.AVIATION /08Z TUESDAY THROUGH SUNDAY/...
A RIDGE OF HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD ACROSS
THE CAROLINAS TODAY INTO TONIGHT. MAINLY VFR CONDITIONS EXPECTED FOR
THE NEXT 24 HOURS. LATEST SATELLITE LOOP INDICATING SOME MVFR CIGS
SPREADING ACROSS THE AREA EARLY THIS MORNING FROM THE EAST. MODELS
ALSO SUGGESTING SOME LOW LEVEL MOISTURE MOVING INTO THE REGION NEAR
EARLY THIS MORNING. WILL USE SOME MVFR CIGS IN TEMPOS WHERE
NECESSARY BEFORE SUNRISE. AFTER 12Z...VFR CONDITIONS ARE EXPECTED TO
CONTINUE WITH JUST SCATTERED CLOUDS AROUND 4 KFT. VBSYS EXPECTED TO
BE 7 MILES OR GREATER THE ENTIRE PERIOD WITH LOW LEVEL WINDS
EXPECTED TO KEEP LOWER LAYERS MIXED NOT ALLOWING FOR MUCH IF ANY FOG
TO DEVELOP NEAR SUNRISE THIS MORNING. SKIES SHOULD BECOME MOSTLY
CLEAR AFTER 00Z WEDNESDAY.

EXTENDED AVIATION OUTLOOK...ANOTHER COLD FRONT WILL CROSS AREA LATE
WEDNESDAY WITH CIG/VSBY RESTRICTIONS POSSIBLE.

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

AREA FORECAST DISCUSSION

NWS COLUMBIA SC

303 AM EDT TUE APR 23 2013

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
A RIDGE OF HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD ACROSS
THE CAROLINAS TODAY INTO TONIGHT. MAINLY VFR CONDITIONS EXPECTED FOR
THE NEXT 24 HOURS. HOWEVER...MODELS SUGGEST SOME LOW LEVEL MOISTURE
MAY MOVE INTO THE REGION NEAR SUNRISE THIS MORNING. BOTH NAM AND
GFS3 FORECAST SOUNDINGS INDICATE SOME MOISTURE AROUND 2 KFT BUT DOES
NOT APPEAR ENOUGH FOR CEILINGS. MOISTURE APPEARS TO BE ADVECTED INTO
AREA ON NORTHEAST WINDS AT 20 KNOTS NEAR SUNRISE. NOT CONFIDENT
ENOUGH TO GO MVFR CEILINGS EARLY THIS MORNING...SO WILL GO JUST 2
KFT SCATTERED. LAMP METEOGRAMS TO SHOW A CEILING ABOUT 2 KFT BUT
STILL THINK SCATTERED CLOUDS WOULD BE A BETTER FORECAST. AFTER
12Z...VFR CONDITIONS ARE EXPECTED TO CONTINUE WITH JUST SCATTERED
CLOUDS AROUND 4 KFT. VBSYS EXPECTED TO BE 7 MILES OR GREATER THE
ENTIRE PERIOD WITH LOW LEVEL WINDS EXPECTED TO KEEP LOWER LAYERS
MIXED NOT ALLOWING FOR MUCH IF ANY FOG TO DEVELOP NEAR SUNRISE THIS
MORNING. SKIES SHOULD BECOME MOSTLY CLEAR AFTER 00Z WEDNESDAY.

EXTENDED AVIATION OUTLOOK...ANOTHER COLD FRONT WILL CROSS AREA LATE
WEDNESDAY WITH CIG/VSBY RESTRICTIONS POSSIBLE.

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

AREA FORECAST DISCUSSION

NWS COLUMBIA SC

141 AM EDT TUE APR 23 2013

.NEAR TERM /THROUGH TODAY/...
HIGH PRESSURE WILL CONTINUE TO RIDGE INTO THE FORECAST AREA FROM
THE NORTH TODAY. CLOUDINESS ASSOCIATED WITH THE OFFSHORE FRONT
WAS AFFECTING THE NORTHEAST PART OF THE FORECAST AREA EARLY THIS
MORNING. THE LATEST RAP SHOWS HIGH LOW-LEVEL MOISTURE CONTINUING
IN THE NORTHEAST PART THROUGH 15Z. EXPECT THIS CLOUDINESS WILL
DIMINISH THIS AFTERNOON AS THE FRONT SHIFTS FARTHER OFFSHORE AND
MIXING CONTINUES. THE TEMPERATURE GUIDANCE WAS CLOSE. THE GUIDANCE
MAY BE A LITTLE TOO WARM IN THE NORTHEAST PART BECAUSE OF
LINGERING CLOUDINESS.

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
THE RIDGE WILL REMAIN NEAR THE FORECAST AREA TROUGH TONIGHT.
EXPECT STRONG NET RADIATIONAL COOLING WHICH MAY LEAD TO AREAS OF
FOG DURING THE EARLY MORNING HOURS. WARMING WILL OCCUR AHEAD OF
THE APPROACHING COLD FRONT WEDNESDAY. THE WARM TEMPERATURE
GUIDANCE IS USUALLY BETTER JUST AHEAD OF A FRONT. THE NAM AND GFS
AGREE KEEPING THE FORCING AND DEEPER MOISTURE WEST OF THE FORECAST
AREA AND EXPECT IT WILL REMAIN DRY WEDNESDAY. THE NAM AND GFS SHOW THE
FRONT MOVING INTO THE AREA WEDNESDAY NIGHT WITH DIMINISHING
MOISTURE. THE GUIDANCE CONSENSUS SUPPORTS CHANCE POPS. THE NAM AND
GFS INDICATE DRYING BEHIND THE FRONT THURSDAY. HOWEVER...THE ECMWF
HAD A SLOWER TIMING SO WE MAINTAINED A SMALL POP THURSDAY. DRY
RIDGING BEHIND THE FRONT SHOULD BE DOMINATE THURSDAY NIGHT.

.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
A RIDGE OF HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD ACROSS
THE CAROLINAS TODAY INTO TONIGHT. MAINLY VFR CONDITIONS EXPECTED FOR
THE NEXT 24 HOURS. HOWEVER...MODELS SUGGEST SOME LOW LEVEL MOISTURE
MAY MOVE INTO THE REGION NEAR SUNRISE THIS MORNING. BOTH NAM AND
GFS3 FORECAST SOUNDINGS INDICATE SOME MOISTURE AROUND 2 KFT BUT DOES
NOT APPEAR ENOUGH FOR CEILINGS. MOISTURE APPEARS TO BE ADVECTED INTO
AREA ON NORTHEAST WINDS AT 20 KNOTS NEAR SUNRISE. NOT CONFIDENT
ENOUGH TO GO MVFR CEILINGS EARLY THIS MORNING...SO WILL GO JUST 2
KFT SCATTERED. LAMP METEOGRAMS TO SHOW A CEILING ABOUT 2 KFT BUT
STILL THINK SCATTERED CLOUDS WOULD BE A BETTER FORECAST. AFTER
12Z...VFR CONDITIONS ARE EXPECTED TO CONTINUE WITH JUST SCATTERED
CLOUDS AROUND 4 KFT. VBSYS EXPECTED TO BE 7 MILES OR GREATER THE
ENTIRE PERIOD WITH LOW LEVEL WINDS EXPECTED TO KEEP LOWER LAYERS
MIXED NOT ALLOWING FOR MUCH IF ANY FOG TO DEVELOP NEAR SUNRISE THIS
MORNING. SKIES SHOULD BECOME MOSTLY CLEAR AFTER 00Z WEDNESDAY.

EXTENDED AVIATION OUTLOOK...ANOTHER COLD FRONT WILL CROSS AREA LATE
WEDNESDAY WITH CIG/VSBY RESTRICTIONS POSSIBLE.

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

AREA FORECAST DISCUSSION

NWS LINCOLN IL

1124 PM CDT MON APR 22 2013

.DISCUSSION...
ISSUED 842 PM CDT MON APR 22 2013

.AVIATION...
ISSUED 1115 PM CDT MON APR 22 2013

TIMING OF RAIN AND LOWER CIGS INTO THE FORECAST AREA THE MAIN
FORECAST CHALLENGE THIS PERIOD. SATELLITE AND OBSERVATIONAL DATA
OUT TO OUR WEST SUGGESTS A SLOWER TRANSITION TO MVFR CIGS ON
TUESDAY AS THE INITIAL WAVE THAT IS BRINGING THE LIGHT SHOWER
ACTIVITY INTO THE AREA LATE THIS EVENING IS ENCOUNTERING A RATHER
DRY AIR MASS. HOWEVER...WITH THE SECOND WAVE FORECAST TO PUSH INTO
THE AREA ON TUESDAY...WE SHOULD SEE DETERIORATING CONDITIONS PUSH
IN DURING THE DAYLIGHT HOURS WHEN CIGS SHOULD LOWER TO MVFR WITH
SOME TEMPO IFR CONDITIONS...ESP IN THE AFTERNOON AND EVENING AND
EVENING. WILL CONTINUE TO INCLUDE VCSH OVERNIGHT...WITH THE STEADIER
RAINS AND ISOLD TSRA MOVING IN BY LATE TOMORROW MORNING OR EARLY
AFTERNOON AS THE COLD FRONT TRACKS ACRS THE AREA. SFC WINDS AHEAD
OF THE FRONT WILL BE OUT OF A SOUTHERLY DIRECTION TONIGHT INTO
TUESDAY MORNING...BUT THEN SWITCH INTO THE NORTHWEST ONCE THE FRONT
MOVES THRU...WHICH LOOKS TO BE FROM 14-16Z AT PIA....15Z-17Z AT
SPI AND BMI...AND FINALLY BY 21Z OUT EAST AT CMI. LOOK FOR THE MVFR
WITH TEMPO IFR CIGS TO CONTINUE INTO THE EVENING HOURS WELL BEHIND
THE FRONT WITH THE RAIN GRADUALLY COMING TO AN END IN THE EVENING.

SMITH
&&

.PREV DISCUSSION...
ISSUED 259 PM CDT MON APR 22 2013

MAIN WEATHER STORY CONTINUES TO BE THE RAIN EVENT COMING INTO THE
PICTURE LATE TONIGHT THROUGH TUESDAY NIGHT.

SHORT TERM...TONIGHT THROUGH THURSDAY

LONG TERM...FRIDAY THROUGH MONDAY

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

AREA FORECAST DISCUSSION

NWS GOODLAND KS

237 AM MDT TUE APR 23 2013

.UPDATE...
ISSUED AT 1109 PM MDT MON APR 22 2013

MODERATE TO HEAVY SNOW CONTINUES TO FALL AROUND THE GLD
AREA...WITH ANOTHER BAND DEVELOPING SOUTH OF YUMA TRACKING ALONG
SIMILAR PATH AS OTHER SNOW BANDS. SNOWFALL AMOUNTS HAVE VARIED
QUITE A BIT...WITH GLD AT 5 INCHES AND ST FRANCIS ONLY REPORTING A
HALF OF AN INCH SO FAR. WITH MUCAPE FIELDS SUPPORTING INSTABILITY
AXIS ALONG AN IDALIA TO RUSSEL SPRINGS LINE FOR THE NEXT FEW HOURS
BEFORE SHIFTING EAST AND STRONG FRONTOGENESIS ALSO FALLING A
SIMILAR PATTERN...THINK HEAVIER SNOW OBSERVED AT GLD WILL CONTINUE
TO MOVE EAST SOUTH EAST. WITH GLD ALREADY NEAR WARNING CRITERIA
AND DUE TO AFOREMENTIONED REASONS HAVE UPGRADED PART OF ADVISORY
TO A WARNING FOR THE REST OF THE NIGHT. CONSIDERED ADDING YUMA AND
CHEYENNE COUNTY KS TO WARNING AS SOUTHERN PART OF COUNTY WILL
LIKELY SEE 6 TO 8 INCHES...BUT STRONG NORTH-SOUTH SNOWFALL
GRADIENT WILL KEEP MUCH OF THESE AREAS BELOW WARNING CRITERIA.
MUCAPE AXIS EVENTUALLY MOVES INTO THE EASTERN CWA CENTERED AROUND
HLC HAVE CONCERNS HEAVY SNOW MAY MAKE IT THIS FAR EAST AS
WELL...BUT NEED TO MONITOR HOW PRECIP FIELDS BEHAVE A BIT LONGER
BEFORE MAKING THAT CALL.

UPDATE ISSUED AT 817 PM MDT MON APR 22 2013

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 223 PM MDT MON APR 22 2013

.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 236 AM MDT TUE APR 23 2013

AN UPPER LEVEL SHORTWAVE WILL TRAVERSE THE AREA AT THE START OF THE
EXTENDED PERIOD. HAVE POPS RANGING FROM SLIGHT CHANCE MIDDLE FA TO
LOW CHANCE EAST ON FRIDAY. MODELS INDICATE BEST LOW LEVEL MOISTURE
TO BE OVER THE EASTERN PORTION OF THE CWA...HENCE HIGHER POPS THERE.
INCLUDED THUNDER GIVEN THAT MODEL FORECAST SOUNDINGS INDICATE AT
LEAST WEAK INSTABILITY. UPPER LEVEL RIDGING BUILDS INTO THE AREA
THIS WEEKEND AND TEMPERATURES WARM TO ABOVE NORMAL. ECMWF IS SLOWER
THAT THE GFS IN SHIFTING THE UPPER LEVEL RIDGE EASTWARD. HAVE
ACCEPTED CR INIT GRIDS FOR MONDAY WHICH SEEM TO BE WEIGHTED TO THE
GFS AND INCLUDE SLIGHT CHANCE POP. GIVEN DISAGREEMENT BETWEEN MODELS
CONFIDENCE IS LOW ON MONDAY AND ADJUSTMENTS WILL LIKELY BE NEEDED IN
LATER FORECASTS.

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1134 PM MDT MON APR 22 2013

PERIOD OF MFVR OR LOWER FLIGHT CONDITIONS EXPECTED AT BOTH
TERMINALS THE REST OF THE NIGHT WITH THE HIGHEST IMPACT/LOWEST
FLIGHT CATEGORIES EXPECTED AT GLD AS AREA OF MODERATE TO HEAVY
SNOW WILL CONTINUE TO MOVE ACROSS THE AREA THROUGH 10Z. WINDS
WILL GRADUALLY WEAKEN THROUGH THE EVENING...ALTHOUGH WILL REMAIN
IN THE 15-22KT RANGE FOR MUCH OF THE PERIOD...BEFORE DECREASING
LATE THIS AFTERNOON. MCCOOK FOR THE MOST PART WILL REMAIN TO THE
NORTH OF HEAVIEST SNOWFALL AND EXPECT REDUCE FLIGHT CATEGORIES TO
BE MORE TRANSIENT IN THIS AREA.

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 9 AM MDT /10 AM CDT/ THIS MORNING
FOR KSZ001>004-015-016-041-042.

WINTER STORM WARNING UNTIL 9 AM MDT /10 AM CDT/ THIS MORNING FOR
KSZ013-014-027>029.

CO...WINTER WEATHER ADVISORY UNTIL 9 AM MDT THIS MORNING FOR COZ090-
092.

WINTER STORM WARNING UNTIL 9 AM MDT THIS MORNING FOR COZ091.

NE...NONE.
&&

UPDATE...JRM
SHORT TERM...JJM
LONG TERM...FS/BRB
AVIATION...JRM

AREA FORECAST DISCUSSION

NWS DODGE CITY KS

244 AM CDT TUE APR 23 2013

...UPDATED LONG TERM SECTION...

.SYNOPSIS...
ISSUED AT 1210 AM CDT TUE APR 23 2013

AT 00Z TUESDAY A -30C TO -32C 500MB TROUGH EXTENDED FROM NORTH
DAKOTA INTO WESTERN WYOMING/EASTERN IDAHO. A +100KT 300MB JET WAS
LOCATED JUST SOUTH OF THIS UPPER TROUGH AND STRETCHED FROM
NORTHERN UTAH INTO NORTHWEST KANSAS. A 700MB TROUGH/BAROCLINIC
ZONE WAS LOCATED FROM SOUTHEAST COLORADO INTO SOUTH CENTRAL
NEBRASKA. AT 00Z TUESDAY AN 850MB COLD FRONT APPEARS TO EXTEND
FROM THE OKLAHOMA PANHANDLE INTO SOUTH CENTRAL KANSAS AND THEN
NORTHEAST INTO SOUTHWEST IOWA. 850MB AND 700MB DEWPOINTS THIS
MORNING INDICATING THE BETTER MOISTURE WAS LOCATED JUST NORTH OF
THIS 850MB FRONT AND SOUTHEAST OF THE 700MB BAROCLINIC ZONE/TROUGH
ACROSS SOUTHERN KANSAS.

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 203 AM CDT TUE APR 23 2013

STEADY SNOW CONTINUES TO FALL ACROSS NORTHWEST KANSAS EARLY AS OF
07Z. THIS RELATED WELL WITH THE MID LEVEL BAROCLINIC ZONE THAT
THE RAP KEEPS NEARLY STATIONARY THROUGH 09Z. THIS BAROCLINIC ZONE
WILL THEN BEGIN TO SLOWLY MOVE SOUTHEAST ACROSS NORTH CENTRAL
KANSAS FROM 09Z TO 15Z AND WILL THEREFORE KEEP CATEGORICAL
PRECIPITATION CHANCES GOING THROUGH LATE MORNING. SNOW
ACCUMULATIONS OF 2 TO NEAR 4 INCHES STILL POSSIBLE BEFORE THE
STEADIER SNOW TAPERS OFF. FURTHER SOUTH ISENTROPIC LIFT AND A
WEDGE OF WARMER AIR IN THE 850-700MB LEVEL WILL RESULT IN A WINTRY
MIX OF FREEZING RAIN, SLEET AND SNOW EARLY THIS MORNING. LATEST
I295 ISENTROPIC SURFACE DOES INDICATE THAT THIS ISENTROPIC LIFT
WILL GIVE WAY TO ISENTROPIC DOWNGLIDE AFTER 12Z SO THE WIDESPREAD
STEADY PRECIPITATION THAT WAS OCCURRING HERE EARLIER THIS MORNING
IN THIS AREA IS EXPECTED TO BECOME MORE WIDELY SCATTERED AND
LIGHTER.

BY THE EARLY AFTERNOON AN AREA OF HIGH PRESSURE AT THE SURFACE
WILL BEGIN TO BUILD INTO WESTERN KANSAS. THERE WILL BE A SLIGHT
CHANCE FOR SOME LIGHT SNOW AHEAD OF AN APPROACHING UPPER LEVEL
TROUGH, HOWEVER LITTLE OR NO ADDITIONAL ACCUMULATION IS EXPECTED.
MODEL SOUNDINGS FOR TODAY INDICATED A DEEP LAYER OF LOW LEVEL
MOISTURE WILL BE PRESENT SO CLOUDY CONDITIONS ARE EXPECTED. GIVEN
THE EXPECTED CLOUD COVER ALONG WITH THE COLD AIR ADVECTION TODAY
IN THE LOWER LEVELS WILL UNDERCUT ALL GUIDANCE FOR HIGHS. THE
PREVIOUS FORECAST STILL LOOKS ON TRACK WITH TEMPERATURES TODAY
MAINLY IN THE LOW TO MID 30S.

SUBSIDENCE DEVELOPING IN THE WAKE OF AN UPPER LEVEL TROUGH WHICH
WILL MOVE EAST OF WESTERN KANSAS EARLY TONIGHT SHOULD ALLOW
CLEARING SKIES TO DEVELOP. AT THE SURFACE AN AREA OF HIGH PRESSURE
WILL CROSS THE CENTRAL HIGH PLAINS DURING THE OVERNIGHT HOURS.
GIVEN CLEARING SKIES, A WEST/NORTHWEST WIND AT LESS THAN 10MPH,
AND SOME SNOW COVER NORTH OF HIGHWAY 50 HAVE DECIDED TO TREND
TOWARDS THE COLDER MET GUIDANCE FOR OVERNIGHT LOWS. TEMPERATURES
BY WEDNESDAY MORNING ARE EXPECTED TO RANGE FROM AROUND 20 TO NEAR
24 DEGREES. THIS CONTINUES TO SUPPORT THE HARD FREEZE WARNING
CURRENTLY IN EFFECT.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 243 AM CDT TUE APR 23 2013

AN UPPER LEVEL SHORTWAVE WILL BE MOVING ACROSS THE NORTHERN PLAINS
AND WESTERN GREAT LAKES REGION ON WEDNESDAY WITH AN 100+ KNOT 250 MB
JET EXTENDING FROM EASTERN COLORADO TO THE OHIO VALLEY. THIS WILL
PLACE WESTERN KANSAS IN A WEST TO NORTHWEST FLOW ALOFT. TOWARDS THE
SURFACE, A DOME OF HIGH PRESSURE WILL CONTINUE TO SLIDE SOUTHEAST
INTO THE SOUTHERN PLAINS ALLOWING WESTERLY WINDS TO BE FELT DURING
THE DAY THEN BECOME LIGHT AND VARIABLE WEDNESDAY NIGHT. SKIES
THROUGH THIS PERIOD WILL GENERALLY BE PARTLY CLOUDY WITH HIGHS IN
THE MID TO UPPER 50S WEDNESDAY AFTERNOON AND LOWS IN THE 30S
THURSDAY MORNING.

ANOTHER UPPER LEVEL SHORTWAVE IS THEN ANTICIPATED TO MOVE INTO THE
DESERT SOUTHWEST THURSDAY THEN LIFT NORTHEAST INTO THE SOUTHERN
ROCKIES THURSDAY NIGHT. HIGH CLOUDS WILL INCREASE IN COVERAGE AS
THIS FEATURE APPROACHES WITH LEE SIDE TROUGHING DEVELOPING ACROSS
EASTERN COLORADO. THIS WILL ALLOW WINDS TO SHIFT TO MORE OF A
SOUTHERLY DIRECTION AND BECOME BREEZY THURSDAY INTO THURSDAY NIGHT.
LOW TO MID LEVEL CLOUDS INCREASE IN COVERAGE THURSDAY NIGHT INTO
FRIDAY WITH THE POSSIBILITY FOR SHOWERS AND THUNDERSTORMS TO DEVELOP
ACROSS PORTIONS OF WESTERN KANSAS. HIGHS THURSDAY WILL GENERALLY BE
IN THE 60S WITH LOWS IN THE 40S FRIDAY MORNING. HIGHS FRIDAY WILL
GENERALLY BE IN THE LOWER 70S.

CLOUDS DECREASE IN COVERAGE FRIDAY NIGHT WITH PARTLY CLOUDY
SKIES AND DRY CONDITIONS ANTICIPATED INTO THE WEEKEND. MEDIUM RANGE
MODELS THEN SUGGEST ANOTHER UPPER LEVEL DISTURBANCE TO POSSIBLY MOVE
NORTH OF THE AREA DURING THE BEGINNING OF NEXT WEEK. THIS COULD
BRING A CHANCE FOR THUNDERSTORMS TO WESTERN KANSAS SUNDAY NIGHT INTO
MONDAY. OTHERWISE EXPECT PARTLY CLOUDY SKIES. THIS WEEKEND LOOK TO BE
IN THE 70S WITH LOWER 80S POSSIBLE ACROSS FAR SOUTHWESTERN KANSAS.
LOWS LOOK TO DIP INTO THE 40S SATURDAY MORNING WITH 50S FORECASTED
FOR SUNDAY AND MONDAY MORNINGS.

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1210 AM CDT TUE APR 23 2013

GUSTY NORTH WINDS AT AROUND 25KTS WILL GRADUALLY DECREASE AFTER
15Z TUESDAY AS A RIDGE OF HIGH PRESSURE AT THE SURFACE BEGINS
BUILD INTO WESTERN KANSAS. WIND SPEEDS OF AROUND 20KTS ARE
EXPECTED BY 15Z. BUFR SOUNDINGS KEEP THE LOWER LEVELS SATURATED
THROUGHOUT THE EARLY MORNING HOURS SO CIGS ARE EXPECTED TO STAY
AS IS OR FALL A FEW HUNDRED FEET INTO THE IFR/LOW MVFR CATEGORY
EARLY THIS MORNING. CIGS WILL BEGIN TO IMPROVE AS PRECIPITATION
ENDS AFTER 12Z. CLEARING SKIES DEVELOPING FROM WEST TO EAST AFTER
00Z WEDNESDAY. WINTRY MIX OF PRECIPITATION IS EXPECTED OVERNIGHT
BUT AFTER 15Z THE BETTER LIFT APPEARS TO START TO SHIFT EAST.

.PRELIMINARY POINT TEMPS/POPS...
DDC 32 22 58 34 / 50 10 0 0
GCK 31 20 58 33 / 80 0 0 0
EHA 35 24 60 37 / 30 10 0 0
LBL 35 24 60 36 / 30 10 0 0
HYS 32 19 55 31 / 80 10 0 0
P28 36 23 58 36 / 60 10 0 0

.DDC WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING UNTIL 8 AM CDT /7 AM MDT/ WEDNESDAY FOR
KSZ030-031-043>046-061>066-074>081-084>090.

WINTER WEATHER ADVISORY UNTIL 10 AM CDT /9 AM MDT/ THIS MORNING
FOR KSZ030-031-043>046-061>066-077>079.

WIND ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR KSZ074>076-080-
081-084>090.

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

AREA FORECAST DISCUSSION

NWS DODGE CITY KS

210 AM CDT TUE APR 23 2013

...UPDATED SHORT TERM DISCUSSION...

.SYNOPSIS...
ISSUED AT 1210 AM CDT TUE APR 23 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 203 AM CDT TUE APR 23 2013

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 110 PM CDT MON APR 22 2013

MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH
SWINGING SOUTHEAST ACROSS THE NORTHERN PLAINS WEDNESDAY AND INTO THE
GREAT LAKES REGION WEDNESDAY NIGHT. ALTHOUGH AN ATTENDANT COLD FRONT
IS PROJECTED TO PUSH SOUTH JUST INTO WESTERN KANSAS LATE WEDNESDAY
BEFORE IT STALLS, LITTLE PRECIP IS EXPECTED ACROSS THE REGION WITH
LITTLE MOISTURE FOR THE SYSTEM TO WORK WITH. MEANWHILE, AN UPPER
LEVEL TROUGH NOW APPROACHING THE COAST OF SOUTHERN CALIFORNIA, WILL
PUSH ASHORE INTO THE DESERT SOUTHWEST THURSDAY THEN LIFT NORTHEAST
INTO THE SOUTHERN ROCKIES THURSDAY NIGHT BRINGING THE POSSIBILITY
FOR SHOWERS AND THUNDERSTORMS TO PORTIONS OF WESTERN KANSAS LATE
THIS WEEK. TIMING REMAINS AN ISSUE AS IT PERTAINS TO THE ARRIVAL OF
THE SYSTEM COMBINED WITH MOISTURE AVAILABILITY. REGARDLESS, THE
BETTER CHANCE FOR PRECIP LOOKS TO BE DURING THE THURSDAY NIGHT INTO
FRIDAY TIME FRAME.

TEMPERATURES WILL BE WELL BELOW NORMAL WEDNESDAY AS A COLD AIR MASS
IS SLOW TO ERODE OUT OF WESTERN KANSAS. SURFACE HIGH PRESSURE IS
PROJECTED TO DRIFT EAST INTO EASTERN KANSAS RESULTING IN FAIRLY
LIGHT AND VARIABLE WIND CONDITIONS ACROSS CENTRAL AND MUCH OF
SOUTHWEST KANSAS ALLOWING THE COLDER AIR TO LINGER. THE NAM, GFS,
AND ECMWF SHOW H85 TEMPERATURES RANGING AROUND TO JUST ABOVE 5C
ACROSS CENTRAL AND SOUTHWEST KANSAS WEDNESDAY AFTERNOON. EVEN WITH
EXPECTED DECREASING CLOUDS, LOOK FOR HIGHS GENERALLY UP INTO THE
50S(F) WITH A FEW 40S(F) STILL POSSIBLE ACROSS CENTRAL KANSAS. FOR
THURSDAY, BROAD SURFACE HIGH PRESSURE ACROSS THE MISSISSIPPI RIVER
VALLEY REGION WILL HELP TO INFLUENCE A LOW LEVEL SOUTHERLY FLOW INTO
WESTERN KANSAS. THIS WILL DRAW WARMER AIR NORTHWARD INTO THE AREA
WITH H85 TEMPERATURES JUST ABOVE 5C ACROSS CENTRAL KANSAS TO NEAR
15C IN FAR WESTERN KANSAS ALONG THE COLORADO BORDER. SHOULD SEE
60S(F) IN CENTRAL KANSAS TO NEAR 70F IN EXTREME WESTERN KANSAS FOR
HIGHS THURSDAY AFTERNOON. THE WARMING TREND WILL CONTINUE INTO THE
WEEKEND AS THE FLOW ALOFT BECOMES MORE ZONAL.

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1210 AM CDT TUE APR 23 2013

.PRELIMINARY POINT TEMPS/POPS...
DDC 32 22 58 34 / 50 10 0 0
GCK 31 20 58 33 / 80 0 0 0
EHA 35 24 60 37 / 30 10 0 0
LBL 35 24 60 36 / 30 10 0 0
HYS 32 19 55 31 / 80 10 0 0
P28 36 23 58 36 / 60 10 0 0

.DDC WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING UNTIL 8 AM CDT /7 AM MDT/ WEDNESDAY FOR
KSZ030-031-043>046-061>066-074>081-084>090.

WINTER WEATHER ADVISORY UNTIL 10 AM CDT /9 AM MDT/ THIS MORNING
FOR KSZ030-031-043>046-061>066-077>079.

WIND ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR KSZ074>076-080-
081-084>090.

SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...JJOHNSON
AVIATION...BURGERT

AREA FORECAST DISCUSSION

NWS GOODLAND KS

1137 PM MDT MON APR 22 2013

.UPDATE...
ISSUED AT 1109 PM MDT MON APR 22 2013

UPDATE ISSUED AT 817 PM MDT MON APR 22 2013

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 223 PM MDT MON APR 22 2013

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 223 PM MDT MON APR 22 2013

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1134 PM MDT MON APR 22 2013

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 9 AM MDT /10 AM CDT/ TUESDAY FOR
KSZ001>004-015-016-041-042.

WINTER STORM WARNING UNTIL 9 AM MDT /10 AM CDT/ TUESDAY FOR
KSZ013-014-027>029.

CO...WINTER WEATHER ADVISORY UNTIL 9 AM MDT TUESDAY FOR COZ090-092.

WINTER STORM WARNING UNTIL 9 AM MDT TUESDAY FOR COZ091.

NE...NONE.
&&

UPDATE...JRM
SHORT TERM...JJM
LONG TERM...RRH
AVIATION...JRM

AREA FORECAST DISCUSSION

NWS GOODLAND KS

1119 PM MDT MON APR 22 2013

.UPDATE...
ISSUED AT 1109 PM MDT MON APR 22 2013

UPDATE ISSUED AT 817 PM MDT MON APR 22 2013

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 223 PM MDT MON APR 22 2013

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 223 PM MDT MON APR 22 2013

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 519 PM MDT MON APR 22 2013

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 9 AM MDT /10 AM CDT/ TUESDAY FOR
KSZ001>004-015-016-041-042.

WINTER STORM WARNING UNTIL 9 AM MDT /10 AM CDT/ TUESDAY FOR
KSZ013-014-027>029.

CO...WINTER WEATHER ADVISORY UNTIL 9 AM MDT TUESDAY FOR COZ090-092.

WINTER STORM WARNING UNTIL 9 AM MDT TUESDAY FOR COZ091.

NE...NONE.
&&

UPDATE...JRM
SHORT TERM...JJM
LONG TERM...RRH
AVIATION...JRM

AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

351 AM CDT TUE APR 23 2013

.DISCUSSION...
FORECAST CONCERNS TODAY WILL BE LIGHT SNOW POTENTIAL FOR SOUTHERN
PARTS OF CWA.

THE SURFACE COLD FRONT HAS PUSHED WELL TO THE SOUTH INTO SOUTHEAST
KANSAS AND NORTHWEST MISSOURI WITH SURFACE HIGH PRESSURE BUILDING
INTO THE REGION. AT H3...THE 120KT JET WAS OVERHEAD AND THE H5 TROF
FROM MONTANA TO NEVADA/UTAH STILL HAD 40DM HT FALLS WITH IT. THE
H3 JET WILL RE-CURVE SLIGHTLY NORTHEAST AS THE H5 TROF SWINGS
THROUGH THE PLAINS TODAY. THIS WILL STRENGTHEN THE MID LEVEL
FRONTOGENETIC FORCING IN NORTHEAST KANSAS AND H7 WARM AIR
ADVECTION BEFORE PUSHING EASTWARD THIS AFTERNOON. DRY LOW LEVELS
WILL BE UNDERCUTTING THE MOIST MID LEVELS...HOWEVER SOUTHEAST
NEBRASKA AND FAR SOUTHERN IOWA LOOKED TO BE CLIPPED WITH
PRECIPITATION WITH THIS STRONGER MID LEVEL FORCING. THE LATEST
WSR-88D MOSAIC HAS THE CONVECTION CLOSER TO THE FRONT OVER
SOUTHERN KANSAS WITH A BAND OF RAIN AND SNOW TRACKING NORTHEAST
ACROSS NORTHERN KANSAS. THE 03Z RAP/01Z HRRR AND LATEST 06Z
HHRR/07Z RAP HAVE BEEN CONSISTENT IN LIFTING SOME LIGHT SNOW INTO
SOUTHEAST NEBRASKA THIS MORNING AND SHIFT IT OUT OF THE AREA BY
18Z. WILL MAINTAIN HIGH PROB OF PRECIPITATION FOR FAR SOUTHEAST
NEBRASKA AND FAR SOUTHERN IOWA. FNB HAS BEEN REPORTING LIGHT RAIN
AND COLD AIR SHOULD CONTINUE TO DECREASE TEMPERATURES FOR A
CHANGEOVER TO SNOW. DID MENTION SOME LIGHT ACCUMULATIONS BEATRICE
TO CLARINDA SOUTHWARD WITH A DUSTING TO AN INCH OR SO AT
FNB...REDUCING THE CHANCES SIGNIFICANTLY AFT 18Z. BREEZY TO WINDY
NORTH WINDS AND COLD AIR ADVECTION TODAY WILL HOLD MOST LOCATIONS
TO THE UPPER 30S AND LOWER 40S.

SURFACE HIGH PRESSURE BUILDS IN TONIGHT WITH MOSTLY CLEAR...COLD
CONDITIONS AND DIMINISHING WINDS. TEMPERATURES WILL DROP INTO THE
20S FOR MOST SPOTS.

WEDNESDAY...THERE WILL BE SOME WARM AIR ADVECTION AHEAD OF A COLD
FRONTAL PASSAGE AND ANOTHER SHORTWAVE TROF DROPPING SOUTH IN THE
FLOW ALOFT. FORECAST SOUNDINGS IMPLY INSTABILITY SHOWERS ARE
POSSIBLE WITH HIGHS IN THE 40S AND 50S. MID LEVEL RIDGING AND
WARMER H85 TEMPERATURES RETURN FOR THURSDAY AHEAD OF A SURFACE
TROF WITH HIGHS IN THE 60S. DEEPER MOISTURE RETURNS AS THE LOW
LEVEL JET STRENGTHENS THURSDAY NIGHT AND FRIDAY. AS A SHORTWAVE
PASSES THROUGH...SOME OF THE THUNDERSTORMS ACROSS KANSAS COULD
SPREAD INTO FAR SOUTHERN NEBRASKA AND SOUTHWEST IOWA.

THE MODELS ARE IN GOOD AGREEMENT THROUGH SATURDAY. HIGH SATURDAY
AND SUNDAY SHOULD WARM TO AT OR ABOVE NORMAL IN THE LOWER 70S.
THERE IS A SUBTLE WAVE THAT COULD BRING SOME ISOLATED SHOWERS AND
THUNDERSTORMS. THE MODELS DO NOT AGREE ON MUCH MOISTURE WILL BE
AVAILABLE...BUT DO SHOW SOME INSTABILITY WITH THE WEAK WAVE. MAY
NEED TO ADD SOME CHANCE OF PRECIP FOR THIS. SUNDAY AND
BEYOND...THERE ARE SOME TIMING ISSUES WITH THE NEXT SHORTWAVE
TROF. GFS IS FASTER...WITH THE EC SLOWER. DO HAVE SOME LOW POPS
SUNDAY NIGHT AND MONDAY...BUT THESE COULD HOLD OFF UNTIL LATER IN
THE WEEK.

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

STRONG NORTHERLY SURFACE FLOW WILL CONTINUE THROUGH 18Z THEN
GRADUALLY DIMINISH 18Z-00Z AS HIGH PRESSURE BUILDS INTO THE AREA.
MVFR CIGS LIKELY THROUGH 18Z BECOMING VFR THEREAFTER. SPEED MAX
ACROSS KANSAS IS EXPECTED TO SPREAD LIGHT SNOW ALONG THE SOUTHERN
BORDER WITH SOME LIGHT SNOW POSSIBLE AS FAR NORTH AS KLNK THROUGH
12Z.

FOBERT

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

ZAPOTOCNY

AREA FORECAST DISCUSSION

NWS RALEIGH NC

310 AM EDT TUE APR 23 2013

.SYNOPSIS...
AN AREA OF HIGH PRESSURE WILL PERSIST OVER CENTRAL NORTH CAROLINA
THROUGH WEDNESDAY WHILE AN AREA OF LOW PRESSURE TRACKS SLOWLY
NORTHEAST OFF THE MID ATLANTIC AND NEW ENGLAND COAST THROUGH
TONIGHT. A COLD FRONT WILL CROSS THE REGION WEDNESDAY NIGHT.

.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 942 PM MONDAY...

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 230 AM TUESDAY...

WEDNESDAY AND WEDNESDAY NIGHT TO FOLLOW SHORTLY.

THURSDAY AND THURSDAY NIGHT:
EXPECT THE SURFACE FRONT WILL BE TO THE SOUTH OF THE AREA BY 12Z
THURSDAY. HOWEVER... THE 850 MB FRONT WILL LIKELY LAG BEHIND A
BIT... HELPING TO SUPPORT CONTINUED CHANCES FOR SOME SHOWERS AT
LEAST DURING THE MORNING HOURS... BEFORE IT IS PUSHED TO THE SOUTH
AND EAST OF THE AREA DURING THE AFTERNOON AS A SECONDARY S/W CROSSES
THE CENTRAL NC. WRT THE TIMING OF THE PRECIP... THE 00Z GFS AND
CANADIAN APPEAR TO ON THE FAST SIDE OF THE OPERATIONAL GUIDANCE...
WITH THE 00Z NAM JUST A BIT SLOWER... WHILE THE 12Z ECMWF IS MUCH
SLOWER. GIVEN SOME OF THE GFS ENSEMBLE MEMBERS ARE SHOWING THE
POTENTIAL TO SLOW THE DEPART OF THE PRECIP... WILL TREND THE
FORECAST CLOSER TO A BLEND OF THE 00Z NAM AND 12Z ECMWF. THIS YIELDS
PRECIP CHANCES ENDING ACROSS EASTERN PORTIONS OF THE AREA BY MID
AFTERNOON OR SO... WITH PARTLY TO MOSTLY CLOUDY SKIES POSSIBLY
LINGERING THROUGH THE AFTERNOON ACROSS OUR FAR EASTERN COUNTIES.
THUS... HAVE TRENDED HIGH TEMPS CLOSER TO THE MET GUIDANCE... WHICH
SHOWS HIGHS RANGING FROM THE MID 60S (POSSIBLY EVEN LOWER 60S)
ACROSS OUR FAR EASTERN COUNTIES... TO THE UPPER 60S TO EVEN 70
DEGREES ELSEWHERE... WHERE A WESTERLY DOWNSLOPE FLOW SHOULD HELP
PROMOTE CLEARING SKIES DURING THE AFTERNOON HOURS WITH LOCATIONS
ACROSS THE WESTERN PIEDMONT MOSTLY SUNNY BY AT LEAST MID AFTERNOON
(WHERE TEMPS MAY BE THE WARMEST).

HIGH PRESSURE WILL BUILD INTO THE AREA THURSDAY NIGHT/FRIDAY
MORNING... WITH A GENERAL WEST-NORTHWEST DRY FLOW ALOFT. THIS SHOULD
YIELD CLEAR SKIES... WITH A GENERAL LIGHT NORTHERLY BREEZE. THUS...
EXPECT LOW TEMPS WILL AGAIN RETURN TO BELOW NORMAL FOR THIS TIME OF
YEAR. EXPECT LOWS FRIDAY MORNING RANGING FROM THE LOWER 40S TO THE
UPPER 40S... WITH PERHAPS A FEW OF THE USUAL RURAL COLD LOCATIONS
DROPPING TO AROUND 40 OR SO.

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 305 AM TUESDAY...

ERY BRIEF WEAK S/W RIDGING WILL BUILD ACROSS THE AREA FRIDAY/FRIDAY
NIGHT... BEFORE THE NEXT DISTURBANCE APPROACHES THE AREA FROM THE
SW. THIS DISTURBANCE IS CURRENTLY LOCATED WELL OFF THE SOUTHWEST
U.S. COAST AROUND 30N AND 130W. THUS... MEDIUM RANGE MODELS CONTINUE
TO STRUGGLE WITH HOW THE SYSTEM EVOLVES AS IT MOVES ACROSS SOUTHERN
U.S. AND INTO OUR REGION BY THIS WEEKEND. THE GFS REALLY SHEARS THE
SYSTEM OUT AS IT MOVES TOWARDS OUR AREA... WHILE THE ECMWF INITIALLY
DOES... BEFORE IT CUTS OFF INTO A CLOSED LOW JUST TO OUR WEST
ALLOWING FOR GOOD MOISTURE TRANSPORT INTO OUR REGION FOR AT LEAST
THE SECOND HALF OF THE WEEKEND. HOW MUCH PRECIP ALONG WITH THE
TIMING IS STILL A BIT IN QUESTION. HOWEVER... IT STILL APPEARS WE
WILL HAVE RATHER UNSETTLED WEATHER ACROSS CENTRAL NC FROM LATE
SATURDAY INTO SUNDAY... WITH AT LEAST LOTS OF CLOUD AND SPOTTY
PRECIP LINGERING INTO NEXT WEEK.

TEMPS OUTSIDE OF FRIDAY WILL BE A CHALLENGE... AS THE AFOREMENTIONED
SURFACE HIGH (WHICH BUILDS INTO THE AREA BEHIND THE FRONT ON
THURSDAY) IS EXPECTED TO SHIFT OFFSHORE AND AND LINGER OFF THE
NORTHEAST U.S. COAST INTO EARLY NEXT WEEK.. THUS... ONCE WE START TO
GET PRECIP FALLING INTO THE DRY SURFACE RIDGE EXPECT WE WILL LIKELY
SEE AT LEAST SOME FORM OF DAMMING AIRMASS DEVELOP ACROSS PORTIONS OF
THE PIEDMONT. EXPECT HIGH TEMPS ON FRIDAY WILL BE IN THE UPPER 60S
TO LOWER 70S... WITH LOWS SATURDAY MORNING IN THE MID TO UPPER 40S
TO AROUND 50 ACROSS THE SOUTH AND SOUTHWEST... WITH MID AND HIGH
CLOUDS ALREADY STARTING TO STREAM BACK INTO THE AREA. TEMPS DURING
THE REMAINDER OF THE PERIOD WILL BE DRIVE LARGELY BY THE PRECIP AND
POSITIONING OF THE SURFACE HIGH. THUS... FOR NOW HAVE LOWERED TEMPS
IN THE DAMMING REGION FROM LATE SATURDAY INTO SUNDAY (WHEN THE BEST
CHANCE OF PRECIP WILL BE)... WITH A SLIGHT INDICATION OF THIS FOR
MONDAY. THIS YIELDS HIGH TEMPS GENERALLY BELOW NORMAL IN THE FAVORED
DAMMING REGION OF THE NORTHWEST PIEDMONT... TO SLIGHT BELOW TO NEAR
NORMAL ACROSS THE SOUTHEAST.

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 140 AM TUESDAY...

A MOIST LOW LEVEL E-NE FLOW WILL CONTINUE TO ADVECT ATLANTIC
MOISTURE INTO CENTRAL NC OVERNIGHT...MAINTAINING CURRENT MVFR
CEILINGS OR LOW END VFR CEILINGS THROUGH DAYBREAK. POCKETS OF IFR
CEILINGS HIGHLY LIKELY FROM KRDU EASTWARD INCLUDING KRWI AND
KFAY...WITH THE FREQUENCY OF IFR CEILINGS MORE LIKELY EAST AND NORTH
OF KRWI.

LATER THIS MORNING...AN AREA OF LOW PRESSURE WILL BEGIN TO PULL AWAY
FROM THE NC COAST. AS THIS WEATHER SYSTEM LIFTS N-NE...THE LOW LEVEL
FLOW WILL BECOME MORE NLY...ENDING THE MOISTURE ADVECTION. THIS WILL
LEAD TO A LIFTING/DISSIPATION OF THE MVFR CEILINGS...BEGINNING BY
9-10 AM IN THE PIEDMONT AND SANDHILLS...AND THE COASTAL PLAIN BY 10
AM-11 AM. THE BULK OF CENTRAL NC WILL EXPERIENCE VFR CONDITIONS BY
EARLY AFTERNOON.

SFC WINDS...CURRENTLY NE SUSTAINED 10KTS WITH GUSTS 16-19KTS WILL
SUBSIDE AND BECOME NLY BY DAYBREAK. BY LATE LATE MORNING INTO THE
AFTERNOON...SFC WINDS WILL BECOME LIGHT AND VARIABLE.

TONIGHT...MAY SEE AN EPISODE OF MVFR-IFR VISIBILITY DUE TO
FOG...ESPECIALLY ACROSS THE SANDHILLS...COASTAL PLAIN...AND EASTERN
PIEDMONT. THIS FOG MAY IMPACT OPERATIONS AT KRDU/KRWI/KFAY. ANY FOG
AND LOW CLOUDS THAT DEVELOP WILL BURN OFF BY 9-10 AM WEDNESDAY
MORNING.

VFR CONDITIONS ANTICIPATED FOR WEDNESDAY. A SURFACE COLD FRONT WILL
CROSS THE REGION WEDNESDAY NIGHT AND EXIT THE REGION THURSDAY
MORNING. THIS WEATHER SYSTEM WILL CAUSE A PERIOD OF MVFR CEILINGS
ALONG WITH AREAS OF RAIN SHOWERS AND MAYBE A THUNDERSTORM OR TWO.

VFR CONDITIONS WILL RETURN TO CENTRAL NC THURSDAY AFTERNOON AND
PERSIST THROUGH EARLY SATURDAY. MAY SEE A BRIEF PERIOD OF SUB VFR
VISIBILITY SATURDAY MORNING. THE NEXT LOW PRESSURE SYSTEM MAY BRING
MVFR CEILINGS TO THE WESTERN PIEDMONT INCLUDING THE TRIAD REGION BY
LATE SATURDAY.

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

SYNOPSIS...WSS
NEAR TERM...KC/SMITH
SHORT TERM...WSS/BSD
LONG TERM...BSD
AVIATION...WSS

AREA FORECAST DISCUSSION

NWS RALEIGH NC

140 AM EDT TUE APR 23 2013

.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 942 PM MONDAY...

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 235 PM MONDAY...

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 245 PM MONDAY...

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 140 AM TUESDAY...

SFC WINDS...CURRENTLY NE SUSTAINED 10KTS WITH GUSTS 16-19KTS WILL
SUBSIDE AND BECOME NLY BY DAYBREAK. BY LATE LATE MORNING INTO THE
AFTERNOON...SFC WINDS WILL BECOME LIGHT AND VARIABLE.

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

SYNOPSIS...WSS
NEAR TERM...KC/SMITH
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...WSS

AREA FORECAST DISCUSSION

NWS LUBBOCK TX

1154 PM CDT MON APR 22 2013

.AVIATION...
STRONG COLD FRONT HAS PUSHED THROUGH BOTH TERMINALS. GUSTY WINDS
WILL PERSIST MUCH OF THE NIGHT AT BOTH TERMINALS WITH LOW CLOUDS
MAKING IT INTO BOTH SITES SHORTLY. BLOWING DUST WILL BE A CONCERN
AT BOTH SITES FOR A FEW HOURS BEHIND THE FRONT.
OTHERWISE...CONDITIONS IMPROVING LATE THIS MORNING.

.PRELIMINARY POINT TEMPS/POPS...
FRIONA 30 45 25 59 36 / 10 10 10 0 10
TULIA 31 46 26 60 38 / 10 10 10 0 10
PLAINVIEW 32 48 27 60 38 / 10 10 10 0 10
LEVELLAND 35 50 28 60 38 / 10 10 10 0 10
LUBBOCK 35 50 30 60 39 / 10 10 10 0 10
DENVER CITY 39 54 26 61 33 / 10 10 10 0 10
BROWNFIELD 38 51 28 61 35 / 10 10 10 0 10
CHILDRESS 36 48 33 62 40 / 10 10 10 0 10
SPUR 39 49 32 61 44 / 10 10 10 0 10
ASPERMONT 43 50 33 62 43 / 10 10 10 0 10

.LUB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 AM CDT TUESDAY FOR THE FOLLOWING ZONES:
TXZ021>044.

99/99/26

AREA FORECAST DISCUSSION

NWS MILWAUKEE/SULLIVAN WI

356 AM CDT TUE APR 23 2013

.TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.

FIRST BAND OF SCATTERED SHOWERS CROSSING CWA AHEAD OF SURFACE
COLD FRONT EARLY THIS MORNING IN REGION OF OF HIGHER LAYER
Q-VECTOR CONVERGENCE AND DIFFERENTIAL CVA WITH INITIAL SHORT
WAVE...AIDED BY WEAK UPPER LEVEL DIVERGENCE WITH COUPLED UPPER
JET...EXPECTED TO CLEAR THE FAR NE AROUND 12Z.

A SECOND AND MORE EXTENSIVE AREA OF PRECIPITATION IS EXPECTED TO
DEVELOP WITH FORCING AHEAD OF MAIN 500 MB TROUGH AND FRONTOGENETIC
RESPONSE LATER THIS MORNING AND THIS AFTERNOON. FOLLOWED TRENDS OF
HRRR AND RAP IN KEEPING MOST OF CWA DRY AFTER THE INITIAL EARLY
MORNING BAND...AND THEN BRINGING PRECIPITATION BACK INTO THE
FORECAST AREA FROM SW TO NE MID TO LATE MORNING WITH HIGHER POPS
WITH THE BETTER OMEGA IN THE SOUTHEAST 1/2 OF CWA. KEPT SLIGHT
CHANCE/CHANCE POPS OVER THE SE 1/2 UNTIL MID LEVEL TROUGH AXES
CLEAR THE REGION AROUND 06Z WED.

EARLY DAY HIGHS...WITH HIGHEST 12 MIDNIGHT TO 12 MIDNIGHT TEMPS
OCCURRING RIGHT NOW IN THE NW AHEAD OF COLD FRONT...THEN FALLING
WITH COLD FRONT PASSAGE...THOUGH THERE MAY BE A BRIEF RECOVERY OF
A FEW DEGREES IN THE NW MID-LATE AFTERNOON AS THE RAIN COMES TO AN
END.

COLD AIR ADVECTION/925 MB TEMPS -3C TO -4C BY 12Z WEDNESDAY/AND
CLEARING SKIES WILL DROP LOW TEMPERATURES INTO THE UPPER 20S
NW...WITH LINGERING CLOUDS KEEPING LOWS IN THE MID 30S SE.

.WEDNESDAY THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM
TO HIGH.

SHORT TERM MODELS SHOWING HIGH PRESSURE RIDGE SLIDING EAST THROUGH
THE REGION ON WEDNESDAY. THIS SHOULD BRING QUIET WEATHER TO THE
AREA. TEMPERATURES WILL BE ON THE COOL SIDE...GIVEN 925MB
TEMPERATURES ONLY AROUND 3 DEGREES CELSIUS.

MODELS ARE IN GOOD AGREEMENT WITH STRONG COLD FRONT PUSHING EAST
THROUGH THE AREA WEDNESDAY EVENING...WITH A STRONG 500MB SHORTWAVE
TROUGH MOVING THROUGH DURING THE EVENING INTO THE OVERNIGHT HOURS.
850MB LOW LEVEL JET NOSE POINTS INTO THE AREA DURING THE EVENING
AS WELL. AREA FORECAST SOUNDINGS SHOWING AIR COLUMN SATURATING FOR
A TIME GENERALLY BETWEEN 02Z AND 08Z THURSDAY...THEN DRYING OUT
WITH DRY AIRMASS MOVING IN BEHIND THE COLD FRONT AND SHORTWAVE
TROUGH.

WILL CONTINUE HIGHER END POPS WEDNESDAY EVENING INTO THE OVERNIGHT
HOURS...THEN TREND DOWN LATER IN THE NIGHT. PRECIPITATION WILL
START AS RAIN...THEN BECOME MIXY...THEN CHANGE TO SNOW FROM WEST
TO EAST IN THE LATE EVENING AND SOON AFTER MIDNIGHT. MAY SEE A
DUSTING OF SNOWFALL ON GRASSY AREAS...ESPECIALLY NORTHWEST OF
MADISON.

MODELS IN GOOD AGREEMENT WITH ANOTHER HIGH PRESSURE RIDGE SLIDING
ACROSS THE REGION THURSDAY...BEFORE GRADUAL WARM AIR ADVECTION
SHIFTS INTO THE REGION THURSDAY NIGHT. AREA FORECAST SOUNDINGS DRY
OUT DURING THIS TIME...SO SHOULD SEE QUIET WEATHER RETURN.
TEMPERATURES WILL REMAIN COOL ON THURSDAY...BEFORE BEGINNING TO
MODERATE THURSDAY NIGHT.

.FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE IS MEDIUM.

GFS/ECMWF ARE IN FAIR AGREEMENT WITH TRENDS FRIDAY INTO SATURDAY
NIGHT. THEY CONTINUE TO BRING A GRADUAL WARM AIR ADVECTION PATTERN
INTO THE REGION. AREA OF QPF WITH WARM FRONT REMAINS NORTH OF THE
AREA FRIDAY...WITH ANOTHER LARGER QPF AREA WITH 500MB SHORTWAVE
TROUGH REMAINING WELL TO THE SOUTH. THIS SHOULD RESULT IN A DRY
PERIOD...WITH SLOWLY MODERATING TEMPERATURES. DID LEAVE LOW POPS
IN FRIDAY NIGHT PER COORDINATION WITH SURROUNDING OFFICES...BUT
THIS PERIOD MAY END UP DRY AS WELL.

DIFFERENCES BETWEEN THE GFS/ECMWF SHOW UP SUNDAY INTO MONDAY. GFS
BRINGS A STRONG COLD FRONT EAST THROUGH THE REGION SUNDAY
NIGHT/MONDAY AND BEYOND...WITH THE ECMWF KEEPING IT WELL NORTHWEST
OF THE AREA. BOTH MODELS DO KEEP AREA IN MILD AIRMASS INTO
MONDAY...THOUGH ONSHORE WINDS SHOULD KEEP LAKESHORE AREAS COOLER.
WILL USE CONSENSUS POPS AND TEMPERATURES IN THIS PERIOD FOR NOW.

.AVIATION/12Z TAFS/...

SCATTERED LIGHT RAIN SHOWERS WITH VFR CIGS WILL EXIT TAF SITES BY
12Z...FOLLOWED BY A MORE EXTENSIVE AREA OF RAIN WITH MVFR CIGS
MOVING IN BY MID-LATE MORNING. LIGHT TO AT TIMES MODERATE
RAIN...ESPECIALLY AT EASTERN TAF SITES...THROUGH THE AFTERNOON
WILL TAPER OFF FROM NW TO SE DURING THE EARLY EVENING...CLEARING
KENW BY 06Z WEDNESDAY. CURRENT POST-FRONTAL IFR DECK WILL REMAIN
WEST OF TAF SITES THROUGH MID-MORNING...BUT WILL BRING IN IFR WITH
THE THE STEADIER RAIN SHOWERS. VFR CONDITIONS RETURN WITH PASSAGE
OF MID-LEVEL TROUGH AFTER 06Z.

.MARINE...

SOME NW GUSTS COULD REACH SMALL CRAFT CRITERIA LATE
AFTERNOON/EARLY EVENING BUT NOT WIDESPREAD OR FREQUENT ENOUGH FOR
A HEADLINE AT THIS TIME BUT WILL MONITOR CLOSELY. BETTER CHANCE
FOR SMALL CRAFT CONDITIONS COMES WEDNESDAY NIGHT INTO THURSDAY
WITH TIGHTENING PRESSURE GRADIENT BEHIND SURFACE LOW PRESSURE THAT
CROSSES LAKE SUPERIOR.

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

TODAY/TONIGHT AND AVIATION/MARINE...REM
WEDNESDAY THROUGH MONDAY...WOOD

AREA FORECAST DISCUSSION

NWS LA CROSSE WI

1138 PM CDT MON APR 22 2013

.UPDATE...
ISSUED AT 852 PM CDT MON APR 22 2013

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 347 PM CDT MON APR 22 2013

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 347 PM CDT MON APR 22 2013

FOCUS IN THE LONG TERM IS ON A RATHER VIGOROUS NORTHERN STREAM
SHORTWAVE FOR WED/WED NIGHT...THEN LOOKING FORWARD TO THE
MUCH-ANTICIPATED FIRST SPRING WARM UP THAT IS POSSIBLE THIS WEEKEND.

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1138 PM CDT MON APR 22 2013

THE MAIN CHALLENGE WITH THE OVERNIGHT FORECAST IS WITH HOW FAST
FLIGHT CONDITIONS WILL IMPROVE THIS MORNING AND THROUGH THE
AFTERNOON HOURS AS A LOW PRESSURE SYSTEM TRACKS TO THE NORTHEAST
THROUGH THE GREAT LAKES. MVFR TO MAINLY IFR CONDITIONS ARE NOTED
ALONG THE BACK SIDE OF THIS LOW FROM WESTERN WISCONSIN ON THROUGH
SOUTHEAST MINNESOTA AND CENTRAL IOWA. THE MAIN PRECIPITATION BAND
IS CURRENTLY COMING TO AN END ACROSS SOUTHEAST MINNESOTA...THOUGH
SOME DRIZZLE OR LIGHT SNOW MAY CONTINUE AFTER THIS MAIN WAVE COMES
THROUGH. OVERALL...EXPECT THAT CONDITIONS WILL GRADUALLY IMPROVE
THROUGH THE MORNING AND AFTERNOON AS DRIER AIR MOVES IN. WINDS
WILL REMAIN GUSTY UNTIL TUESDAY EVENING WHEN A RIDGE OF HIGH
PRESSURE WILL PUSH IN FROM THE WEST.

.HYDROLOGY...TONIGHT/TUESDAY
ISSUED AT 347 PM CDT MON APR 22 2013

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 9 AM CDT TUESDAY FOR WIZ017.

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

UPDATE...HALBACH
SHORT TERM...ZT
LONG TERM...ZT
AVIATION...HALBACH
HYDROLOGY...ZT

AREA FORECAST DISCUSSION

NWS COLUMBIA SC

739 AM EDT TUE APR 23 2013

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL CONTINUE TO RIDGE INTO THE FORECAST AREA FROM
THE NORTH TODAY. CLOUDINESS ASSOCIATED WITH THE OFFSHORE FRONT
WAS AFFECTING MAINLY THE NORTHEAST PART OF THE FORECAST AREA
EARLY THIS MORNING. THE LATEST RAP SHOWS HIGH LOW-LEVEL MOISTURE
CONTINUING IN THE NORTHEAST PART THROUGH 15Z. EXPECT THIS
CLOUDINESS WILL DIMINISH LATER THIS MORNING OR EARLY THIS
AFTERNOON AS THE FRONT SHIFTS FARTHER OFFSHORE. HEATING AND MIXING
SHOULD ALSO RESULT IN LESS CLOUDINESS. THE TEMPERATURE GUIDANCE
WAS CLOSE. THE GUIDANCE MAY BE A LITTLE TOO WARM IN THE NORTHEAST
PART BECAUSE OF LINGERING CLOUDINESS.

.AVIATION /12Z TUESDAY THROUGH SUNDAY/...
A RIDGE OF HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD ACROSS
THE CAROLINAS TODAY INTO TONIGHT. MAINLY VFR CONDITIONS EXPECTED FOR
THE NEXT 24 HOURS. LATEST SATELLITE LOOP INDICATING AN OVERCAST
LAYER OF CLOUDS THAT HAVE SPREAD IN FROM THE NORTHEAST OVERNIGHT.
THESE CLOUDS MAINLY AFFECTING THE TAF SITES OF CAE/CUB/DNL. EXPECT
HE MVFR CONDITIONS TO PERSIST FOR A COUPLE OF HOURS...WITH CLOUDS
BECOMING SCATTERED BY MID/LATE MORNING. SKIES SHOULD BECOME MOSTLY
CLEAR AFTER 00Z WEDNESDAY. OVERNIGHT...THE POTENTIAL EXIST FOR SOME
LIGHT FOG...HAVE NOT INCLUDED ANY AT THE TAF SITES AT THIS TIME DUE
TO LOW CONFIDENCE.

EXTENDED AVIATION OUTLOOK...ANOTHER COLD FRONT WILL CROSS AREA LATE
WEDNESDAY NIGHT INTO EARLY THURSDAY WITH CIG/VSBY RESTRICTIONS
POSSIBLE.

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

AREA FORECAST DISCUSSION

NWS COLUMBIA SC

640 AM EDT TUE APR 23 2013

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL CONTINUE TO RIDGE INTO THE FORECAST AREA FROM
THE NORTH TODAY. CLOUDINESS ASSOCIATED WITH THE OFFSHORE FRONT
WAS AFFECTING MAINLY THE NORTHEAST PART OF THE FORECAST AREA
EARLY THIS MORNING. THE LATEST RAP SHOWS HIGH LOW-LEVEL MOISTURE
CONTINUING IN THE NORTHEAST PART THROUGH 15Z. EXPECT THIS
CLOUDINESS WILL DIMINISH LATER THIS MORNING OR EARLY THIS
AFTERNOON AS THE FRONT SHIFTS FARTHER OFFSHORE. HEATING AND MIXING
SHOULD ALSO RESULT IN LESS CLOUDINESS. THE TEMPERATURE GUIDANCE
WAS CLOSE. THE GUIDANCE MAY BE A LITTLE TOO WARM IN THE NORTHEAST
PART BECAUSE OF LINGERING CLOUDINESS.

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
A RIDGE OF HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD ACROSS
THE CAROLINAS TODAY INTO TONIGHT. MAINLY VFR CONDITIONS EXPECTED FOR
THE NEXT 24 HOURS. LATEST SATELLITE LOOP INDICATING SOME MVFR CIGS
SPREADING ACROSS THE AREA EARLY THIS MORNING FROM THE EAST. MODELS
ALSO SUGGESTING SOME LOW LEVEL MOISTURE MOVING INTO THE REGION NEAR
EARLY THIS MORNING. WILL USE SOME MVFR CIGS IN TEMPOS WHERE
NECESSARY BEFORE SUNRISE. AFTER 12Z...VFR CONDITIONS ARE EXPECTED TO
CONTINUE WITH JUST SCATTERED CLOUDS AROUND 4 KFT. VBSYS EXPECTED TO
BE 7 MILES OR GREATER THE ENTIRE PERIOD WITH LOW LEVEL WINDS
EXPECTED TO KEEP LOWER LAYERS MIXED NOT ALLOWING FOR MUCH IF ANY FOG
TO DEVELOP NEAR SUNRISE THIS MORNING. SKIES SHOULD BECOME MOSTLY
CLEAR AFTER 00Z WEDNESDAY.

EXTENDED AVIATION OUTLOOK...ANOTHER COLD FRONT WILL CROSS AREA LATE
WEDNESDAY WITH CIG/VSBY RESTRICTIONS POSSIBLE.

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

AREA FORECAST DISCUSSION

NWS COLUMBIA SC

615 AM EDT TUE APR 23 2013

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL CONTINUE TO RIDGE INTO THE FORECAST AREA FROM
THE NORTH TODAY. CLOUDINESS ASSOCIATED WITH THE OFFSHORE FRONT
WAS AFFECTING MAINLY THE NORTHEAST PART OF THE FORECAST AREA
EARLY THIS MORNING. THE LATEST RAP SHOWS HIGH LOW-LEVEL MOISTURE
CONTINUING IN THE NORTHEAST PART THROUGH 15Z. EXPECT THIS
CLOUDINESS WILL DIMINISH LATER THIS MORNING OR EARLY THIS
AFTERNOON AS THE FRONT SHIFTS FARTHER OFFSHORE. HEATING AND MIXING
SHOULD ALSO RESULT IN LESS CLOUDINESS. THE TEMPERATURE GUIDANCE
WAS CLOSE. THE GUIDANCE MAY BE A LITTLE TOO WARM IN THE NORTHEAST
PART BECAUSE OF LINGERING CLOUDINESS.

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
A RIDGE OF HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD ACROSS
THE CAROLINAS TODAY INTO TONIGHT. MAINLY VFR CONDITIONS EXPECTED FOR
THE NEXT 24 HOURS. LATEST SATELLITE LOOP INDICATING SOME MVFR CIGS
SPREADING ACROSS THE AREA EARLY THIS MORNING FROM THE EAST. MODELS
ALSO SUGGESTING SOME LOW LEVEL MOISTURE MOVING INTO THE REGION NEAR
EARLY THIS MORNING. WILL USE SOME MVFR CIGS IN TEMPOS WHERE
NECESSARY BEFORE SUNRISE. AFTER 12Z...VFR CONDITIONS ARE EXPECTED TO
CONTINUE WITH JUST SCATTERED CLOUDS AROUND 4 KFT. VBSYS EXPECTED TO
BE 7 MILES OR GREATER THE ENTIRE PERIOD WITH LOW LEVEL WINDS
EXPECTED TO KEEP LOWER LAYERS MIXED NOT ALLOWING FOR MUCH IF ANY FOG
TO DEVELOP NEAR SUNRISE THIS MORNING. SKIES SHOULD BECOME MOSTLY
CLEAR AFTER 00Z WEDNESDAY.

EXTENDED AVIATION OUTLOOK...ANOTHER COLD FRONT WILL CROSS AREA LATE
WEDNESDAY WITH CIG/VSBY RESTRICTIONS POSSIBLE.

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

AREA FORECAST DISCUSSION

NWS DODGE CITY KS

645 AM CDT TUE APR 23 2013

...UPDATED AVIATION SECTION...

.SYNOPSIS...
ISSUED AT 1210 AM CDT TUE APR 23 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 203 AM CDT TUE APR 23 2013

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 243 AM CDT TUE APR 23 2013

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 642 AM CDT TUE APR 23 2013

LIGHT SNOW WILL CONTINUE THIS MORNING WITH MVFR TO IFR CONDITIONS
ACROSS THE TAF SITES. VISIBILITIES AND CEILINGS SHOULD INCREASE TO
VFR BY THIS AFTERNOON WITH HYS BEING THE ONLY TERMINAL WHERE
ADDITIONAL SNOW MAY BE OBSERVED. WINDS WILL GENERALLY BE FROM THE
NORTH AROUND 20 KNOTS GUSTING TO AROUND 30 KNOTS AT TIMES.

.PRELIMINARY POINT TEMPS/POPS...
DDC 32 22 58 34 / 50 10 0 0
GCK 31 20 58 33 / 80 0 0 0
EHA 35 24 60 37 / 30 10 0 0
LBL 35 24 60 36 / 30 10 0 0
HYS 32 19 55 31 / 80 10 0 0
P28 36 23 58 36 / 60 10 0 0

.DDC WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING UNTIL 8 AM CDT /7 AM MDT/ WEDNESDAY FOR
KSZ030-031-043>046-061>066-074>081-084>090.

WINTER WEATHER ADVISORY UNTIL 10 AM CDT /9 AM MDT/ THIS MORNING
FOR KSZ030-031-043>046-061>066-077>079.

WIND ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR KSZ074>076-080-
081-084>090.

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

AREA FORECAST DISCUSSION

NWS GRAND RAPIDS MI

859 AM EDT TUE APR 23 2013

.SYNOPSIS...
ISSUED AT 400 AM EDT TUE APR 23 2013

STEADY RAINS WILL ARRIVE THIS AFTERNOON AND LINGER INTO THIS
EVENING. MOST AREAS WILL SEE BETWEEN A HALF AN INCH AND AN INCH OF
RAIN. THIS SHOULD NOT RESULT IN RISING RIVER LEVELS...BUT IT WILL
DELAY THEIR FALL. COOLER AIR MOVES IN BEHIND THE COLD FRONT THAT
WILL PRODUCE THIS RAIN. DAYTIME TEMPERATURES FOR BOTH WEDNESDAY AND
THURSDAY WILL ONLY BE IN THE 40S. ANOTHER PERIOD OF LIGHTER RAIN IS
EXPECTED WEDNESDAY NIGHT INTO THURSDAY MORNING. THERE SHOULD ALSO
BE SOME SNOW THAT MIXES IN WITH THE RAIN. PORTIONS OF CENTRAL LOWER
MICHIGAN COULD SEE A LIGHT DUSTING OF ACCUMULATION BY THURSDAY
MORNING.

WEATHER CONDITIONS SHOULD IMPROVE FOR THE LATTER PORTION OF THE WEEK
INTO THE WEEKEND. MAINLY DRY CONDITIONS ARE EXPECTED ALONG WITH
WARMING TEMPERATURES. BY SUNDAY AND MONDAY MID TO UPPER 60S SHOULD
BE SEEN.

.UPDATE...
ISSUED AT 859 AM EDT TUE APR 23 2013

BASED ON THE LATEST RAP MODEL RUN (10Z)...THE 00Z NSSL WAF AND
HOW NICELY THE CURRENT RADAR MOSAICS AND OBSERVATIONS MATCH THOSE
MODELS... I HAVE SIGNIFICANTLY LOWERED THE POPS FOR THE REST OF
THE MORNING INTO THE EARLY AFTERNOON. NEARLY ALL THE RAIN THAT
WILL HAPPEN TODAY WILL BE RELATED TO THE SOUTHERN STREAM WAVE.
THAT WILL MOVE IN FROM THE SOUTHWEST EARLY TO MID AFTERNOON AND
OVERSPREAD THE REST OF THE CWA DURING THE LATE AFTERNOON INTO THE
EARLY EVENING. STILL LOOKS LIKE IT WOULD END AS SOME LIGHT SNOW
BUT NOT MUCH ACCUMULATION IS EXPECTED.

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 400 AM EDT TUE APR 23 2013

ANOTHER WET PERIOD IS IN STORE FOR THIS AFTERNOON AND EVENING. THE
GOOD NEWS HOWEVER IS THAT THE MODELS HAVE BACKED OFF ON THE
INTENSITY OF THE MID LEVEL FGEN...WHICH COULD HAVE PUT DOWN POCKETS
OF HEAVIER RAIN. WE WILL STILL SEE FGEN FORCING...BUT IT APPEARS
LESS INTENSE AND IS OVER THE AREA FOR A SHORTER TIME...MAINLY
BETWEEN 22Z AND 06Z. AS A RESULT BELIEVE THE RAINFALL WILL BE
FAIRLY UNIFORM RATHER THAN SEEING POCKETS OF FGEN HEAVIER BULLS
EYE.

A SECONDARY WAVE RIDES UP THE FRONT LATE TONIGHT INTO WEDNESDAY
WHICH MAY EXTEND THE RAIN A BIT LONGER INTO WED OVER THE SE CWA.
HAVE INCREASED POPS THERE. WITH THIS SECOND WAVE BELIEVE NOW THAT
THE HEAVIEST RAINS WILL OCCUR OVER THE SOUTHERN HALF OF THE
CWA...WHERE FEWER HYDRO CONCERNS EXIST. EXPECT THE NORTHERN CWA
WILL SEE BETWEEN A HALF INCH AND THREE QUARTERS OF AN INCH...WHILE
AREAS ALONG AND SOUTH OF I-96 SHOULD GET THREE QUARTERS TO AN INCH
OF RAIN.

IT ALSO BECOMES COLD ENOUGH FOR SOME SNOW ON THE BACKSIDE OF THE
COLD FRONT. WE WILL HAVE TO WATCH THE SECOND WAVE LATE TONIGHT INTO
WED MORN. IF THIS SYSTEM COMES A BIT CLOSER ACCUMS WOULD BE MORE
LIKELY...HOWEVER AT THIS POINT ONLY EXPECT A FEW NORTHERN AREAS
PICKING UP A LIGHT DUSTING.

NOT MUCH OF A BREAK BETWEEN SYSTEMS...AS THE NEXT NORTHERN STREAM
SHORT WAVE ARRIVES WEDNESDAY NIGHT. THIS SYSTEM WILL NOT HAVE DEEP
MOISTURE SINCE IT DOES NOT TAP THE GULF. STILL...THE SHORT WAVE
DEEPENS AS IT MOVES IN AND LIKELY POPS LOOK WARRANTED. ONCE AGAIN
MANY AREAS WILL PROBABLY SEE A RAIN SNOW MIX BY LATE WED NIGHT INTO
THU MORNING...BUT ACCUMS IN THE NORTH SHOULD ONLY BE A DUSTING.

.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 AM EDT TUE APR 23 2013

UPPER PATTERN BECOMES ZONAL AT THE START OF THE LONG TERM IN A SPLIT
FLOW REGIME WITH LOWER MICHIGAN SITUATED IN BETWEEN THE TWO BRANCHES
OF THE JET. THIS WILL PROVIDE FAIRLY BENIGN WEATHER TOWARD THE END
OF THE WEEK AND INTO EARLY PORTIONS OF THE WEEKEND.

MAIN FORECAST ISSUE WAS THE UPPER LOW THAT THE ECMWF WAS DRIFTING
INTO THE GREAT LAKES SUNDAY INTO MONDAY. THE NEW RUN OF THE ECMWF
HAS BACKED OFF ON THIS IDEA KEEPING THE LOW FURTHER SOUTH. AT THIS
TIME HAVE A DRY FORECAST FROM THURSDAY NIGHT THROUGH SUNDAY AS THERE
IS LITTLE IN THE WAY OF DEEP MOISTURE OF LIFT.

HAVE SMALL CHANCES FOR RAIN SHOWERS IN THE FORECAST FOR SUNDAY NIGHT
INTO MONDAY AS THE ECMWF BRINGS SOME MOISTURE NORTH INTO THE AREA IN
SOUTHERLY FLOW. STILL...NOT OVERLY IMPRESSED AND THE LONG TERM LOOKS
MAINLY DRY. TEMPERATURES FRIDAY THROUGH MONDAY LOOK TO BE ABOVE
NORMAL WITH HIGHS WELL INTO THE 60S OVER THE WEEKEND.

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 741 AM EDT TUE APR 23 2013

CONDITIONS WILL DETERIORATE THROUGH DAY AS A COLD FRONT APPROACHES
FROM THE WEST. CLOUDS WILL LOWER AND THICKEN WITH WIDESPREAD
SHOWERS BREAKING OUT THIS AFTERNOON. CONDITIONS SHOULD BE VFR THIS
MORNING...WITH MVFR TAKING HOLD THIS AFTERNOON. A PERIOD OF IFR IS
EXPECTED LATE THIS AFTERNOON AND EARLY EVENING AS A BAND OF
HEAVIER RAIN PUSHES THROUGH. THERE IS THE CHANCE FOR A FEW
THUNDERSTORMS BETWEEN 400 PM AND MIDNIGHT...BUT GIVEN LOW
POTENTIAL DID NOT INCLUDE IN THE TAFS. THE BAND OF RAIN WILL MOVE
GRADUALLY TO THE EAST TONIGHT WITH CONDITIONS IMPROVING FROM WEST
TO EAST OVERNIGHT.

.MARINE...
ISSUED AT 400 AM EDT TUE APR 23 2013

WILL GO AHEAD A ISSUE A SCA FOR TONIGHT INTO WED. COLD ADVECTION
AND BRISK NW WINDS BEHIND THE COLD FRONT WILL CAUSE ROUGH CONDITIONS.

.HYDROLOGY...
ISSUED AT 400 AM EDT TUE APR 23 2013

SMALLER STREAMS AND CREEKS WILL SEE RISES WITH THIS AFTERNOON/S AND
EVENING RAINS. THE LARGER RIVER WILL SEE THEIR FALL SLOWED BY THIS
RAIN...BUT MUCH OF ANY RISE ARE NOT EXPECTED.

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 4 PM EDT WEDNESDAY
FOR LMZ844>849.

UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...JK
MARINE...JK

AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

550 AM CDT Tue Apr 23 2013

.SHORT TERM...(Today and Tonight)
Issued at 412 AM CDT TUE APR 23 2013

A very challenging forecast this morning with several concerns
through the upcoming 24 hours. Early this morning, an initial wave of
warm advection showers and embedded thunderstorms continue to slowly
lift northeast into the CWA. Rainfall amounts haven`t been overly
impressive through the night, but those numbers should steadily
increase through daybreak as this wave of rain moves across the
southern half of the CWA.

The big story today will be with a very late season snowfall
potential over the northwestern third of the CWA. Colder air has
surged southward into the CWA this morning, a little bit more
aggressive than models indicated. By daybreak, several pieces of
guidance indicated that a weak 700 mb vort max will track eastward
out of NW Kansas and into the northwestern corner of the CWA.
Impressive 700:600 mb frontogenesis already producing light to
moderate snowfall accumulations in northwestern Kansas will begin to
re-orientate itself as the aforementioned shortwave tracks east.
RAP/NAM guidance indicate this area of lift is expected to narrow
it`s axis as it moves into the CWA. Cross sections through this axis
reveal layered -EPV just above this area of frontogenesis suggesting
that there will be the potential for a very narrow band of moderate
snow.

As always, many variables come into play to address just how much
snow could accumulate, surface temperatures, snowfall rate, wet bulb
temperatures. There will likely be a very defined cutoff on the
southern edge of potential accumulations given warm air in place and
warm ground, but given the forcing see the potential for 1-2" of
snow and wouldn`t be surprised if the precip band really gets
organized to see a few isolated higher amounts along a line from St.
Joseph to Maryville and Bethany.

This band of frontogenesis will quickly begin to diminish late in
the morning and HRRR/RAP guidance indicates that the introduction of
dry air aloft should shut off any moderate precipitation. However,
soundings do suggest the potential for lingering flurries, sprinkles
or sleet into early afternoon.

Tonight: The second part of the story will be with overnight low
temperatures. An already cold day will lead to an even colder night
as clouds slowly clear from NW to SE. Current projections indicate
that readings will fall below 30 in many areas, with the exception
perhaps in the far SE where cloud cover may linger longer. Will go
ahead and issue a freeze warning for areas which will fall at or
below 30 degrees for a sustained amount of time. Interestingly
enough, the record low for Kansas City is 32 degrees set back in
1893. For St. Joseph, the record low is 30 degrees set back in 1996.

.LONG TERM...(Wednesday through Monday)
Issued at 412 AM CDT TUE APR 23 2013

Wednesday night-Thursday morning:

A fast moving clipper type system will swing through the Upper MS
Valley with the southern extension of the system grazing northern MO
as a cold front drops south through the CWA. Could see scattered
light showers on the southern end of the trough skirt northern MO
during the evening hours.

Cool high pressure will slide into eastern KS/western MO. The
combination of clear skies, light winds and temperatures/dewpoints
near the freezing mark provide a favorable setting for some frost
towards sunrise Thursday.

Thursday night-Friday:

With minor differences this far out the medium range models continue
to show decent run-to-run continuity with respect to a compact
vorticity max/shortwave ejecting out of the desert southwest and
tracking through KS/OK. As the system moves out into the Southern
and Central Plains it will interact with an increasing
south-southwesterly low level jet that will be pulling up a better
supply of low-level moisture. The ensuing isentropic ascent combined
with the upper dynamics will likely result in scattered convection
spreading across KS/MO. Best bet for rain in our CWA will be south
of I-70. Favored the slower ECMWF/NAM solutions and the 00Z. GFS is
now trending that way as well so slowed down arrival of
precipitation.

Saturday-Monday:

Will finally get an extended taste of seasonal temperatures as
significant warming through h8 spreads across the central U.S.
Progged soundings support highs into the upper 60s-middle 70s.

While the weekend should remain dry for the most part there are
considerable differences between the GFS and ECMWF/GEM. The GFS drops
a moderately strong upper trough through the Northern
Rockies/Northern Plains Sunday/Sunday night while the latter two
models are more muted, slower and depict an upper ridge over the
Central Plains and Mid MO Valley. So, have low confidence on
precipitation forecast Sunday night-Monday and side with climatology
this far out.

.AVIATION...(For the 12Z TAFS through 12Z Wednesday Morning)
Issued at 545 AM CDT TUE APR 23 2013

Regional radar reflectivity indicates that the widespread initial
area of rain will move east of the terminals within the upcoming
hour. Short range guidance from the HRRR handles this setup well,
lifting visibilities through 13-14Z before additional precipitation in
central Kansas arrives. For the KC terminals, appears a rain/snow
mixture may be possible as this secondary wave of precip moves
through, with MVFR to periodic IFR ceilings through the morning.
Further north, St. Joseph stands the highest probability of seeing a
complete transition to light snow.

Precipitation may dwindle to drizzle by early in the afternoon before
ending by 20z. Ceilings will slowly rise this afternoon and the
clearing line should approach the terminals after midnight tonight.

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...FREEZE WARNING from 1 AM to 8 AM CDT Wednesday FOR KSZ025-057-
060-102>105.

MO...FREEZE WARNING from 1 AM to 8 AM CDT Wednesday FOR MOZ001>008-
011>017-020>024-028>031-037-038-043-053.

SHORT TERM...31
LONG TERM...MJ
AVIATION...31

AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

616 AM CDT TUE APR 23 2013

.AVIATION...12Z TAFS FOR KOMA...KLNK AND KOFK. BAND OF LIGHT SNOW
MOVING THROUGH SOUTHEAST NEBRASKA THIS MORNING...AND BELIEVE THAT
KLNK COULD BE JUST ON THE EDGE. MVFR CLOUDS THAT HAD EXISTED HAVE
SCATTERED OUT TEMPORARILY AT KLNK/KOMA...BUT STILL CAN`T RULE OUT
AN MVFR CEILING YET THIS MORNING. ALSO THINK THAT KLNK COULD STILL
SEE AN OCCASIONAL FLURRY THIS MORNING IF MVFR CEILINGS CAN
REDEVELOP FROM 14 TO 18Z. OTHERWISE...NO OTHER SIGNIFICANT
AVIATION ISSUES THROUGH THE PERIOD.

.PREV DISCUSSION... /ISSUED 351 AM CDT TUE APR 23 2013/

DISCUSSION...
FORECAST CONCERNS TODAY WILL BE LIGHT SNOW POTENTIAL FOR SOUTHERN
PARTS OF CWA.

THE SURFACE COLD FRONT HAS PUSHED WELL TO THE SOUTH INTO SOUTHEAST
KANSAS AND NORTHWEST MISSOURI WITH SURFACE HIGH PRESSURE BUILDING
INTO THE REGION. AT H3...THE 120KT JET WAS OVERHEAD AND THE H5 TROF
FROM MONTANA TO NEVADA/UTAH STILL HAD 40DM HT FALLS WITH IT. THE
H3 JET WILL RE-CURVE SLIGHTLY NORTHEAST AS THE H5 TROF SWINGS
THROUGH THE PLAINS TODAY. THIS WILL STRENGTHEN THE MID LEVEL
FRONTOGENETIC FORCING IN NORTHEAST KANSAS AND H7 WARM AIR
ADVECTION BEFORE PUSHING EASTWARD THIS AFTERNOON. DRY LOW LEVELS
WILL BE UNDERCUTTING THE MOIST MID LEVELS...HOWEVER SOUTHEAST
NEBRASKA AND FAR SOUTHERN IOWA LOOKED TO BE CLIPPED WITH
PRECIPITATION WITH THIS STRONGER MID LEVEL FORCING. THE LATEST
WSR-88D MOSAIC HAS THE CONVECTION CLOSER TO THE FRONT OVER
SOUTHERN KANSAS WITH A BAND OF RAIN AND SNOW TRACKING NORTHEAST
ACROSS NORTHERN KANSAS. THE 03Z RAP/01Z HRRR AND LATEST 06Z
HRRR/07Z RAP HAVE BEEN CONSISTENT IN LIFTING SOME LIGHT SNOW INTO
SOUTHEAST NEBRASKA THIS MORNING AND SHIFT IT OUT OF THE AREA BY
18Z. WILL MAINTAIN HIGH PROB OF PRECIPITATION FOR FAR SOUTHEAST
NEBRASKA AND FAR SOUTHERN IOWA. FNB HAS BEEN REPORTING LIGHT RAIN
AND COLD AIR SHOULD CONTINUE TO DECREASE TEMPERATURES FOR A
CHANGEOVER TO SNOW. DID MENTION SOME LIGHT ACCUMULATIONS BEATRICE
TO CLARINDA SOUTHWARD WITH A DUSTING TO AN INCH OR SO AT
FNB...REDUCING THE CHANCES SIGNIFICANTLY AFT 18Z. BREEZY TO WINDY
NORTH WINDS AND COLD AIR ADVECTION TODAY WILL HOLD MOST LOCATIONS
TO THE UPPER 30S AND LOWER 40S.

SURFACE HIGH PRESSURE BUILDS IN TONIGHT WITH MOSTLY CLEAR...COLD
CONDITIONS AND DIMINISHING WINDS. TEMPERATURES WILL DROP INTO THE
20S FOR MOST SPOTS.

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

AREA FORECAST DISCUSSION

NWS WILMINGTON OH

1042 AM EDT TUE APR 23 2013

.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO SLIDE EAST EARLY TODAY. A COLD
FRONT WILL APPROACH LATER TODAY AND THEN PUSH THROUGH THE AREA
TONIGHT AND WEDNESDAY. SHOWERS WILL ACCOMPANY THE FRONT FOLLOWED
BY ANOTHER PERIOD OF COOLER TEMPERATURES FOR THE LATTER HALF OF
THE WORK WEEK.

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW AMPLITUDE MID LEVEL RIDGE IS LOCATED OVER THE SOUTHEAST US
TODAY WITH A BROAD TROUGH IN THE NATIONS MID SECTION. SURFACE HIGH
PRESSURE IS CENTERED NEAR NEW ENGLAND WITH A COLD FRONT
APPROACHING FROM THE MS VALLEY. CLOUDS HAVE BEGUN ENCROACHING
FROM THE WEST THIS MORNING...MAINLY IN THE FORM OF THIN CIRRUS.
THESE CLOUDS WILL CONTINUE TO THICKEN AND LOWER THROUGH THE DAY.
SATELLITE IMAGERY AND WEBCAMS SUGGEST A FAIRLY OPAQUE SKY IN
WESTERN INDIANA SO I HAVE SIGNIFICANTLY INCREASED CLOUD COVER
TODAY NORTHWEST OF I-71 AS THESE CLOUDS ADVECT IN. INCREASING
SOUTHERLY FLOW WILL HELP OFFSET THE CLOUD COVER AS GUSTS WILL
APPROACH 20-25 KT THIS AFTERNOON. THEREFORE HAVE KEPT HIGH
TEMPERATURES THE SAME IN THE NW...WITH A SLIGHT BUMP UP IN THE SE
(SOME MID 70S EXPECTED) BASED ON CURRENT TRENDS AND PERHAPS A BIT
MORE SUN.

REGARDING PRECIPITATION CHANCES...MODIFIED THE POP FORECAST TO
MIRROR MORE CLOSELY THE RUNS OF HIGH RESOLUTION MODELS...WHICH ARE
PRETTY CONSISTENT IN BRINGING AN INITIAL SHOT OF MOISTURE AND
LIFT TO THE NORTHERN WHITEWATER AND MIAMI VALLEYS THIS AFTERNOON
(MAINLY IN 21-00Z TIME FRAME). HAVE ADDED THUNDER TO THE FORECAST
PER INSTABILITY IN NAM AND RAP FORECAST SOUNDINGS. HOWEVER WITH
POOR SOLAR INSOLATION AND MEAGER CAPE (WHICH MAY BE ELEVATED)...DO
NOT EXPECT ROBUST ENOUGH UPDRAFTS TO BE ABLE TO TAP INTO THE
MODERATE SHEAR THAT IS IN PLACE...SO STRONG STORMS ARE NOT
EXPECTED AT THIS TIME. THE MODELS DIFFER ON WHETHER THERE WILL BE
A BREAK BETWEEN THIS INITIAL ACTIVITY AND THE MAIN FRONTAL BAND
ACROSS WEST CENTRAL OHIO...SO JUST DEPICTED A FAIRLY SMOOTH BLEND
INTO THE PREVIOUS FORECAST.

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE COLD FRONT WILL PUSH INTO INDIANA THIS EVENING...THEN INTO
OHIO BY WEDNESDAY MORNING. SHOWERS WILL BECOME WIDESPREAD LATE
TONIGHT AS MOISTURE IS TRANSPORTED ALONG THE FRONT ON A STRONG
SOUTHWESTERLY FLOW ALOFT. THOUGH SURFACE BASED INSTABILITY WILL BE
LACKING DURING THE OVERNIGHT PERIOD...THERE WILL BE ENOUGH
ELEVATED CAPE TO PRODUCE ISOLATED THUNDERSTORMS. CURRENT
INDICATIONS ARE THAT AROUND A HALF AN INCH OF RAIN WILL OCCUR WITH
THE RATHER MOIST BUT FAST MOVING FRONT.

AS THE FRONT CONTINUES ITS EASTWARD PROGRESS...SHOWERS WILL
LINGER INTO WEDNESDAY BEFORE ENDING FROM WEST TO EAST WEDNESDAY
AFTERNOON. A BRIEF DRY PERIOD IS SUGGESTED FOR WEDNESDAY EVENING
BEFORE A DISTURBANCE MOVING THROUGH THE GREAT LAKES BRINGS A
CHANCE FOR RAIN AND SNOW SHOWERS TO NORTHERN LOCATIONS LATE
WEDNESDAY NIGHT INTO EARLY THURSDAY.

TEMPERATURES WILL BE MUCH COOLER BEHIND THE FRONT WITH HIGHS
AROUND 50 ON WEDNESDAY AND IN THE MID 50S ON THURSDAY. WITH
EXPECTED LOWS IN THE MID 30S WEDNESDAY NIGHT...FROST MAY
FORM...BUT ITS OCCURRENCE MAY BE LIMITED BY CLOUDS AND WINDS.

.LONG TERM /THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL MOVE ACROSS THE REGION THURSDAY NIGHT THROUGH
FRIDAY NIGHT. TEMPERATURES WILL BE BELOW NORMAL DURING THIS PERIOD
WITH SOME FROST NOT OUT OF THE QUESTION THURSDAY NIGHT.

12Z MODELS CONTINUE TO SHOW VARYING SOLUTIONS FOR THE WEEKEND INTO
THE BEGINNING OF NEXT WEEK. WPC PREFERENCE LEANS TOWARDS SLOWER
ECMWF BASED ON FLOW EVOLUTION UPSTREAM AND HAVE FOLLOWED ALONG WITH
THAT THINKING. THIS WILL LEAD TO UNSETTLED CONDITIONS FOR SATURDAY
THROUGH MONDAY AS A MID LEVEL TROUGH GETS BLOCKED FROM PROGRESSING
EAST AND MAY EVEN CLOSE OFF FOR A TIME. AT THIS POINT GREATER
CHANCES OF RAIN APPEAR TO BE OVER THE WEEKEND. CLOUDS AND
PRECIPITATION POTENTIAL SHOULD NARROW THE DAILY DIURNAL RANGE WITH
LOWS AVERAGING ABOVE NORMAL AND HIGH REMAINING BELOW NORMAL.

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
HIGH CLOUDS WILL BE ON THE INCREASE THIS MORNING IN THE WAA PATTERN
AHEAD OF AN APPROACHING COLD FRONT. EXCEPT FOR SOME EARLY MVFR
VSBY RESTRICTIONS DUE TO FOG AT KLUK...VFR CONDITIONS WILL PERSIST
THRU THE MORNING. AHEAD OF THE FRONT...THE PRESSURE GRADIENT WILL
TIGHTEN THROUGH THE DAY...LEADING TO AN INCREASE IN SOUTHERLY
WINDS WITH WIND GUSTS UP TO 25 KTS. CLOUDS WILL SLOWLY LOWER WITH
MID LEVEL CIGS DEVELOPING TOWARD EVENING. A FEW SCTD TO ISOLD
SHOWERS WILL BE PSBL DURG THE AFTN WITH THE BEST CHANCE ACRS KDAY
AND HAVE A MENTION OF VCSH TO ACCOUNT FOR THIS INITIAL LIMITED
COVERAGE. WIDESPREAD PCPN WILL DEVELOP TONIGHT WITH THE BULK OF
THE SHOWERS ASSOCIATED WITH THE FRONTAL PASSAGE AFTER 06Z. EXPECT
SOME EMBEDDED THUNDER DURG THE LATE EVENING BUT DUE TO LIMITED
COVERAGE HAVE LIMITED THUNDER MENTION MENTION TO VCTS. HAVE
PREVAILING RAIN SHOWERS DEVELOPING AT ALL TAF SITES BETWEEN 07Z
AND 08Z WITH MVFR CIGS AND VSBYS DEVELOPING. SRLY WINDS WILL SHIFT
TO THE NW LATE TONIGHT WITH THE FRONTAL PASSAGE AND CONTINUE FROM
THE NW AT 10 TO 15 KTS.

OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE WEDNESDAY.

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.

$$
SYNOPSIS...CONIGLIO
NEAR TERM...SNYDER
SHORT TERM...CONIGLIO
LONG TERM...
AVIATION...AR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY

NWS RAPID CITY SD

517 AM MDT TUE APR 23 2013

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 341 AM MDT TUE APR 23 2013

CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER THE
SOUTHERN PLAINS...WITH HIGH PRESSURE GENERALLY OVER THE NORTHERN
HIGH PLAINS. UPPER LEVEL ANALYSIS SHOWS TROF STRETCHING FROM THE
UPPER MIDWEST INTO THE CENTRAL PLAINS AND CENTRAL ROCKIES. SKIES
HAVE BECOME MAINLY CLEAR ACROSS MUCH OF THE AREA...EXCEPT FOR SOME
LINGERING LOW CLOUDS ACROSS THE BLACK HILLS AREA INTO SOUTHWESTERN
SD. TEMPS HAVE DROPPED INTO THE TEENS ACROSS MUCH OF THE AREA...WITH
SOME SINGLE DIGITS OVER THE BLACK HILLS. WINDS ARE LIGHT FROM THE
WEST TO NORTHWEST IN MOST AREAS.

COOLER WEATHER WILL PERSIST ACROSS THE AREA FOR A COUPLE OF MORE
DAYS BEFORE A SIGNIFICANT WARMUP TAKES PLACE DURING THE LATTER HALF
OF THE WEEK AND THE WEEKEND. FOR TODAY...SKIES WILL BE MAINLY SUNNY.
SOME ISOLATED TO SCATTERED CUMULUS WILL LIKELY DEVELOP IN SPOTS TO
THE SOUTH AND EAST OF THE BLACK HILLS BY THE AFTERNOON...WITH SOME
INCREASING HIGH CLOUDS ACROSS NORTHERN AND WESTERN AREAS DURING THE
AFTERNOON. HIGHS WILL BE IN THE 30S AND LOWER 40S... GENERALLY
WARMEST ACROSS SNOWCOVER FREE AREAS OF FAR NORTHWESTERN SD. WEST TO
NORTHWEST WINDS WILL PERSIST ACROSS THE AREA...INCREASING A BIT
DURING THE LATE MORNING AND AFTERNOON.

CLOUDS WILL CONTINUE TO INCREASE TONIGHT AND LOWER AS CANADIAN COLD
FRONT APPROACHES. THE FRONT WILL MOVE THROUGH NORTHERN AND WESTERN
PORTIONS OF THE CWA LATE TONIGHT AND ACROSS THE REST OF THE FORECAST
AREA DURING THE MORNING. CHANCES FOR SNOW SHOWERS WILL INCREASE
ACROSS FAR NORTHEASTERN WY...THE NORTHERN BLACK HILLS...AND MUCH OF
NORTHWESTERN SD AFTER MIDNIGHT AND ESPECIALLY TOWARD MORNING AS
FRONT MOVES THROUGH. THE BEST UPPER LEVEL SUPPORT WITH THIS FRONT IS
LIKELY TO MOVE THROUGH JUST BEHIND THE COLD FRONT DURING THE MORNING
AND MIDDAY HOURS. WILL KEEP CHANCES FOR SHOWERS ACROSS THE
AREA...MOSTLY SNOW IN THE MORNING AND THEN A MIX TO RAIN INTO THE
AFTERNOON. THE BEST CHANCES FOR PCPN WILL BE ACROSS THE NORTHERN
BLACK HILLS...WHERE BETTER MOISTURE AND UPSLOPE FLOW WILL LIKELY
PRODUCE SOME LIGHT ACCUMULATIONS OF SNOW LATE TONIGHT INTO
WEDNESDAY. ACCUMULATIONS THERE LOOK TO BE UP TO 2 INCHES OR SO LATE
TONIGHT AND WEDNESDAY. ELSEWHERE...ANY ACCUMULATIONS SHOULD
GENERALLY BE LESS THAN AN INCH LATE TONIGHT INTO WEDNESDAY MORNING.
SHOWERS WILL DISSIPATE LATE IN THE DAY AS WAVE PUSHES QUICKLY
SOUTHEAST OF THE AREA.

THE OTHER FORECAST CONCERN WITH THIS SYSTEM WILL BE WINDS. THEY WILL
INCREASE IN THE MORNING BEHIND THE FRONT AND PERSIST THROUGH THE
AFTERNOON. THE STRONGEST WINDS ALOFT WILL MOVE ACROSS NORTHWESTERN
INTO CENTRAL SD DURING THE MORNING. THIS WOULD SUGGEST THE STRONGEST
WINDS WILL BE FOR A BRIEF PERIOD BEHIND THE FRONT. WINDS AT THIS
POINT LOOK TO BE IN THE LOW END ADVISORY CRITERIA FOR AT LEAST A
COUPLE OF HOURS IN THE MORNING TO MIDDAY HOURS ACROSS A GOOD PORTION
OF THE NORTHWEST AND WEST CENTRAL SD PLAINS. WINDS SHOULD QUICKLY
DIMINISH LATE IN THE DAY AND EARLY EVENING AS MIXING CEASES.

.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 341 AM MDT TUE APR 23 2013

PERSISTENT HIGH HEIGHTS OVER THE EASTERN PAC AND FAR
WESTERN NOAM WILL RETROGRADE WEST IN THE PERIOD...WITH A DOWNSTREAM
PATTERN CHANGE EXPECTED TO EVOLVE AS WESTERN ATLANTIC RIDGE BLOCKING
WILL DIMINISH. THIS WILL LEAD TO GRADUAL LOWER HEIGHTS OVER THE
EASTERN PAC AND FAR WESTERN NOAM...SETTING THE STAGE FOR MUCH WARMER
WEATHER INTO THE LOCAL REGION. PROGRESSIVE FAST FLOW LOOKS TO REMAIN
IN PLACE OVER SOUTHERN CANADA...SUPPORTING A SEMI ZONAL FLOW
INTO THE REGION. THE DEGREE OF TROUGHING IN THE NW CONUS AND THE
POSITION OF THIS FEATURE WILL HAVE AN IMPACT ON THE DEGREE OF LOCAL
WARMING AS WELL AS ITS DURATION. THE 00Z ECMWF IS CERTAINLY THE
FARTHEST WEST BIAS PER THIS FEATURE WHEN COMPARED THE GFS/GEFS/AND
NAEFS. IT ALSO DEVELOPS A STAUNCH OMEGA BLOCK EXTENDING NORTH INTO
THE BERING SEA...WITH THE GFS/GEFS/AND NAEFS SETTLING FOR SPLIT FLOW
PER THIS FEATURE...ALLOWING TROUGHING TO PROGRESS FARTHER EAST EARLY
NEXT WEEK. THE OUTCOME OF THIS EVOLUTION WILL HAVE AN IMPACT ON
PRECIP CHANCES AND TEMPS TOWARD THE END OF THE PERIOD AND BEYOND.

MAIN FEATURE IN THE PERIOD IS THE EXPECTED WARMING TREND THROUGH THE
WEEKEND. WAA ENSUES THUR AND WILL CONTINUE INTO THE WEEKEND. TEMPS
REMAIN QUITE TRICKY IN THE PERIOD...ESP EARLY ON WITH SIG SNOW PACK
IN PLACE ACROSS MUCH OF THE AREA. HOWEVER...MOSTLY SUNNY CONDITIONS
WITH THE WESTERLY DOWNSLOPE FLOW WILL CERTAINLY AID IN PUSHING TEMPS
UP...WITH A TREND TOWARD THE MIDDLE OF GUIDANCE FAVORED ATTM...ESP
AS SNOW WILL SIG MELT THE NEXT TWO DAYS WITH TEMPS IN THE 30S AND
40S UNDER STRONG APRIL SUN. WESTERN NOAM TROUGHING WILL DEVELOP WITH
AN ASSOCIATED LEAD IMPULSE EXPECTED TO ROUND THE TROUGH TOWARD THE
END OF THE WEEKEND SUPPORTING A SFC REFLECTION. THIS FEATURE WILL
PUSH INTO THE REGION SUNDAY-SUNDAY NIGHT AND SUPPORT LL THETA-E
RIDGING...POSSIBLY SUPPORTING A SHOWER OR TS OVER THE HIGH TERRAIN
OF NE WY OR THE BH THEN...WITH POSSIBLE SHOWERS ALONG AND AHEAD OF
THE SFC TROUGH SUNDAY NIGHT INTO MONDAY. THIS IS THE ONLY PRECIP
MENTION ATTM IN THE PERIOD...AND IS CONFINED TO THE NW ZONES.
OTHERWISE...CONTINUED SEASONAL TEMPS MONDAY...WITH A SLIGHT
DOWNTREND IN TEMPS PER A POSSIBLE COLD FRONTAL INFLUENCE.

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 512 AM MDT TUE APR 23 2013

VFR CONDITIONS WILL CONTINUE THROUGH TODAY AS HIGH PRESSURE
COVERS THE REGION. A FAST MOVING UPPER TROUGH WILL SUPPORT
LOWERING CIGS ACROSS THE NORTHERN HALF OF THE FA LATE
TONIGHT...WITH POSSIBLE VIS RESTRICTIONS IN -SN. HAVE ADDED A
MVFR CIG MENTION AT GCC FOR THIS TREND. ATTM...PROB FOR
RESTRICTIONS AT RAP REMAIN LOW GIVEN NW FLOW AND BH DOWNSLOPE
EFFECTS.

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

SHORT TERM...26
LONG TERM...JC
AVIATION...JC

AREA FORECAST DISCUSSION

NWS MILWAUKEE/SULLIVAN WI

1056 AM CDT TUE APR 23 2013

.AVIATION/18Z TAFS/...SLUG OF RAIN SPREADING RAPIDLY ACROSS SE AND
PORTIONS OF SC WI. THIS ASSOCIATED WITH STRONG 200-300 MILLIBAR
JET STREAK SWINGING NE PER WATER VAPOR ANIMATION. ENHANCED UPPER
DIVERGENCE PROGGD BY GUID MAKES SENSE. COUPLE OF VORT MAXES ACROSS
SE IA AND NRN IL ENHANCING LIFT AS WELL. WINDS SETTING UP FROM THE
NORTHWEST IN THE WAKE OF THE FRONT. RAIN AREA WILL AFFECT SE CWA
INTO THE EVENING HOURS AND THEN TAPER OFF. CEILINGS PREDOMINANTLY
MVFR WITH VSBYS LOOKING TO BE IN THAT CATEGORY FOR THE MOST PART
WITH THE RAIN. WATCHING BACK EDGE CAREFULLY WITH COLDER AIRMASS
FILTERING IN. RAP SOUNDINGS TOO WARM IN THE LOW LEVELS...SO WET
FLAKES MIXING IN AT KMSN NOT OUT OF THE QUESTION. SHORTWAVE
RIDGING BUILDS IN LATER TONIGHT INTO WEDNESDAY AHEAD OF THE NEXT
WEATHER MAKER FOR WEDNESDAY NIGHT.

.PREV DISCUSSION... /ISSUED 356 AM CDT TUE APR 23 2013/

TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.

COLD AIR ADVECTION/925 MB TEMPS -3C TO -4C BY 12Z WEDNESDAY/AND
CLEARING SKIES WILL DROP LOW TEMPERATURES INTO THE UPPER 20S
NW...WITH LINGERING CLOUDS KEEPING LOWS IN THE MID 30S SE.

WEDNESDAY THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM
TO HIGH.

FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE IS MEDIUM.

AVIATION/12Z TAFS/...

MARINE...

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

$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
WEDNESDAY THROUGH MONDAY...WOOD

AREA FORECAST DISCUSSION

NWS EUREKA CA

950 AM PDT TUE APR 23 2013

.UPDATE...HAVE ADJUSTED MAX TEMPS UP QUITE A BIT AT COASTAL
LOCATIONS. TEMPS AT THE COAST HAVE ALREADY REACHED YESTERDAY`S MAX
VALUES AND JUST INLAND FROM THE COAST ARE SEVERAL DEGREES ABOVE
YESTERDAY`S VALUES. LIGHT OFFSHORE FLOW IS DOWNSLOPING...CAUSING
RH VALUES ALONG THE COAST TO CRASH AS WELL. BOTH RUC AND GFS
INDICATE 1000-700MB THICKNESSES RISING A BIT MORE TODAY BEFORE
COMING DOWN TONIGHT AND WED. EXPECT MAX TEMPS TO REACH AT LEAST
THE MID 70S AT KACV BEFORE ONSHORE FLOW KICKS IN THIS AFTERNOON.
WILL CONTINUE TO MONITOR FOR ADDITIONAL UPDATES. /SEC

.PREV DISCUSSION... /ISSUED 438 AM PDT TUE APR 23 2013/

SYNOPSIS...HIGH PRESSURE AND OFFSHORE FLOW IS BRINGING MOSTLY
CLEAR SKIES AND WARM TEMPERATURES TO THE AREA TODAY. HIGH
PRESSURE WILL PERSIST THROUGH THE WEEK BUT COASTAL STRATUS WILL
MOVE UP THE COAST FROM THE SOUTH REACHING THE MENDOCINO COAST BY
LATE THIS AFTERNOON AND TO THE REDWOOD COAST BY WEDNESDAY. A WEAK
SYSTEM WILL BRING SOME CLOUDS AND COOLER TEMPERATURES LATE IN THE
WEEK.

SHORT TERM...HIGH PRESSURE AND STRONG OFFSHORE FLOW IS KEEPING
THE AREA CLEAR THIS MORNING. AREAS ALONG THE COAST WITH WIND HAVE
BEEN WARMING OVERNIGHT WITH LOW 60S REPORTED IN SOME AREAS WHILE
NEARLY CALM LOCATIONS CONTINUE TO SHOW MID 40S. CURRENTLY NEAREST
CLOUDS ARE DOWN BY BODEGA BAY AND MOVING NORTH UP THE COAST.
EXPECT THEY WILL MOVE INTO POINT ARENA LATE THIS
AFTERNOON...ALTHOUGH IT COULD BE A BIT EARLIER. LOCAL WRF BACKS
THIS UP SHOWING SOME SOUTHERLY WINDS SPREADING NORTH THIS
AFTERNOON AS WELL. NORTHERLIES ARE STILL FAIRLY STRONG SO EXPECT
IT WILL TAKE A BIT FOR THE STRATUS TO MAKE IT AROUND CAPE
MENDOCINO. TEMPERATURES TODAY SHOULD BE FAIRLY SIMILAR TO
YESTERDAY...EXCEPT IN AREAS OF MENDOCINO COUNTY WHERE THE MARINE
LAYER WILL KEEP THINGS A BIT COOLER. KEPT SKIES CLEAR NORTH OF
CAPE MENDOCINO TONIGHT WITH STRONG OFFSHORE FLOW REMAINING IN
PLACE.

WEDNESDAY IT LOOKS LIKE THE STRATUS WILL MAKE IT AROUND CAPE
MENDOCINO IN THE MORNING AND PUSH INLAND TO THE REDWOOD COAST
BY AFTERNOON. NAM IS STILL STRUGGLING WITH THIS...LOOKS TO BE
ABOUT 24 HOURS TOO SLOW IN BRINGING THEM IN. INITIALIZATION WAS
QUITE POOR...IT WAS NOT EVEN SHOWING THE CLOUDS DOWN BY THE SFO
BAY AREA. THE RIDGE BEGINS TO WEAKEN ON WEDNESDAY SO THIS SHOULD
KEEP TEMPERATURES INLAND A FEW DEGREES COOLER AS WELL. IF THE
MARINE LAYER DOES MAKE IT AROUND THE CAPE ON WEDNESDAY
TEMPERATURES NEAR THE COAST WILL BE MUCH COOLER THAN ON TUESDAY.

WEDNESDAY NIGHT INTO THURSDAY MORNING EXPECT WIDESPREAD CLOUDS
AND SOME FOG ALONG THE COASTAL AREAS. THESE SHOULD PUSH BACK TO
THE COAST AND THERE MAY BE SOME PARTIAL CLEARING AT THE COAST
THURSDAY AFTERNOON. TEMPERATURES INLAND WILL COOL A FEW DEGREES ON
THURSDAY AS THE RIDGE CONTINUES TO WEAKEN AND TEMPERATURES ALOFT
DROP A DEGREE OR TWO. MKK

LONG TERM...MODEL SOLUTIONS BEGINS TO DIVERGE ON FRIDAY. THE 06Z
GFS RUN HAS A WEAKER SYSTEM MOVING THROUGH MORE QUICKLY ON
SATURDAY WITH A RIDGE BUILDING BACK IN BEHIND IT ON SUNDAY AND
MONDAY. THE 00Z ECMWF KEEPS THE RIDGE IN PLACE THROUGH EARLY
SUNDAY BEFORE BRINGING A DEEPER TROUGH THROUGH ON MONDAY AND
TUESDAY. THIS ECMWF SOLUTION IS A LOT SLOWER ON MOVING THE TROUGH
THROUGH THAN PREVIOUS RUNS. EITHER SOLUTION BRING LITTLE TO NO
RAINFALL TO THE AREA THROUGH THE NEXT WEEK. SO CONFIDENCE IS
LOWER THAN AVERAGE THROUGH THE EXTENDED. MKK

AVIATION...FOG SATELLITE SHOWS CLEAR SKIES ACROSS NORTHWEST
CALIFORNIA, MAINLY DUE TO OFFSHORE FLOW. EXPECT VFR TO PREVAIL.
GUSTY NORTHERLY WINDS WILL DEVELOP ALONG THE COAST THIS AFTERNOON AS
HIGH PRESSURE OFFSHORE INTERACTS WITH A THERMAL TROUGH INLAND. WINDS
SHOULD BE LESS BREEZY INLAND.

MARINE...NO MAJOR CHANGES MADE TO THE MARINE FORECAST. NORTHERLY
WINDS WILL CONTINUE AS HIGH PRESSURE OFFSHORE INTERACTS WITH A
THERMAL TROUGH INLAND TO MAINTAIN A STRONG PRESSURE GRADIENT.
NEARSHORE BUOYS SHOW LIGHT TO MODERATE WINDS WHILE THE 04Z ASCAT
PASS SHOWED WINDS OF ABOUT 25-30 KT ACROSS ZONE 470 (WHICH MATCHES A
SHIP REPORT THERE OF ABOUT 30 KT) AND 20-25 KT ACROSS ZONE 475. WAVE
OBSERVATIONS SEEM TO MATCH THE LATEST SWAN RUN. LEFT ALL OF THE
HEADLINES UNCHANGED. WINDS/SEAS WILL MAINTAIN THIS MORNING AND THEN
INCREASE/BUILD THIS AFTERNOON AS THE GRADIENT STRENGTHENS. GALE
CONDITIONS WILL CONTINUE FOR ZONE 470 THIS AFTERNOON THROUGH TONIGHT
WHERE GUSTS TO 40 KT ARE EXPECTED. VERY STEEP 12 TO 15 FT FRESH
SWELL GENERATED HERE WILL PROPAGATE INTO ZONE 475 WHERE THE
HAZARDOUS SEAS WARNING IS UP. GUSTS TO GALE FORCE ARE EXPECTED
ACROSS THE NORTHWEST PORTION OF THIS ZONE. EXPECT ELEVATED WINDS AND
SEAS ACROSS ZONE 450 THROUGH TONIGHT. MODELS ARE IN GOOD AGREEMENT
SHOWING THE GRADIENT WEAKENING LATE TONIGHT INTO WEDNESDAY WITH THE
WAVES SUBSIDING AT THE SAME TIME. THERE MAY BE SOME STRONGER WINDS
ACROSS THE EXTREME NORTHWEST PORTION OF ZONE 470 WHERE THE GRADIENT
MIGHT REMAIN STRONGER FOR A LITTLE BIT LONGER, THROUGH POSSIBLY
THURSDAY. REGARDLESS, EXPECT LIGHT TO MODERATE WINDS AND LOW SEAS
THURSDAY AND FRIDAY.

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 3 AM PDT WEDNESDAY PZZ450.

GALE WARNING UNTIL 3 AM PDT WEDNESDAY PZZ470.

SMALL CRAFT ADVISORY UNTIL 8 PM PDT WEDNESDAY PZZ475.

HAZARDOUS SEAS WARNING UNTIL 3 AM PDT WEDNESDAY PZZ475.

VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA

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HTTP://WWW.TWITTER.COM/NWSEUREKA

AREA FORECAST DISCUSSION

NWS TAUNTON MA

421 PM EDT TUE APR 23 2013

.SYNOPSIS...
A COASTAL STORM TRACKING SOUTHEAST OF NANTUCKET WILL BRING A
CHILLY RAIN TO SOUTHEAST NEW ENGLAND THROUGH TONIGHT. DRIER AND
MILD WEATHER ARRIVES WED. A QUICK MOVING COLD FRONT WILL PASS
THROUGH WEDNESDAY NIGHT INTO THURSDAY. MAINLY DRY AND SEASONABLY
COOL WEATHER RETURNS FRIDAY INTO EARLY NEXT WEEK THANKS TO STRONG
HIGH PRESSURE ANCHORED ACROSS THE REGION.

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
3 PM UPDATE...

WESTERN EDGE OF RAIN SHIELD OVER CAPE COD AND ISLANDS HAVING HARD
TIME MAKING PROGRESS INLAND. HIGHER RESOLUTION RAP HAS A VERY GOOD
HANDLE ON RADAR TRENDS AND ONLY BRINGS MEASURABLE RAINFALL INTO RI
AND EASTERN MA THROUGH THIS EVENING...BUT ONLY A FEW HUNDREDTHS AT
THAT. HEAVIEST RAINFALL WILL CONTINUE TO BE FOCUSED ON CAPE COD
AND ISLANDS. STILL HAVE POTENTIAL FOR ISOLATED THUNDER NEAR S
COAST AS UPPER TROUGH SWINGS THROUGH FROM MIDNIGHT TO DAYBREAK WED
AND AIRMASS DESTABILIZES ALOFT.

OTHERWISE CLOUDY SKIES EXPECTED THROUGHOUT REGION WITH SPOTTY
DRIZZLE AS FAR INLAND AS WORCESTER HILLS AND NW RI. USED A BLEND
OF GFS/NAM MOS FOR LOWS WHICH RANGE FROM MID 30S FAR NW TO MID 40S
SE.

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
SYSTEM WILL HEAD TO MARITIMES WED. MODELS DIFFER ON TIMING OF
ARRIVAL OF DRIER AIR WITH NAM A BIT SLOWER THAN OTHER MODELS...BUT
ALL SHOW ENOUGH DRYING BY MIDDAY TO ALLOW FOR AT LEAST PARTIAL
CLEARING...EVEN ALONG COAST. WE INDICATED CLEARING NEAR CT RIVER
VALLEY FIRST THING IN MORNING...AND BY MID TO LATE MORNING FARTHER
E. IT MAY TAKE UNTIL MIDDAY AROUND CAPE COD AND ISLANDS.

SOME QUESTION AS TO WHETHER OR NOT SEA BREEZES WILL DEVELOP WED.
IT DOES APPEAR GRADIENT WEAKENS ENOUGH IN AFTERNOON TO SUPPORT
THEIR DEVELOPMENT...BUT IT MAY TAKE UNTIL MID AFTERNOON FOR THAT
TO OCCUR. ANY SEA BREEZES SHOULD BE SHORT LIVED AS INCREASING SW
FLOW TAKES OVER TOWARD EVENING.

FORECAST HIGHS ARE A CHALLENGE AS NAM KEEPS MORE
CLOUDINESS/ONSHORE FLOW THAN GFS AND THEREFORE HAS COOLER
TEMPERATURES NEAR COAST. FAVORED WARMER GFS MOS WHICH YIELDS HIGHS
IN 60S COAST/70S INLAND.

NEXT FRONT IS ALREADY ON OUR DOORSTEP WED EVENING AND IS EXPECTED
TO CROSS SOUTHERN NEW ENGLAND OVERNIGHT. ALTHOUGH INSTABILITY IS
LIMITED...FAIRLY IMPRESSIVE JET DYNAMICS COULD COMPENSATE ENOUGH
TO PRODUCE ISOLATED THUNDER AS FRONT MOVES THROUGH. LIMITING
FACTOR IS DIMINISHING LOW LEVEL CONVERGENCE ALONG FRONT AS IT
REACHES NEW ENGLAND...SO ONLY INCLUDED CHANCE POPS AND MENTION OF
ISOLATED THUNDER FOR NOW.

SW FLOW SHOULD PREVENT TEMPERATURES FROM DROPPING MUCH WED NIGHT.
USED BLEND OF GFS/NAM MOS WHICH YIELDS LOWS IN 40S TO AROUND 50.

.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...

* COLD FRONT MOVES OFFSHORE THURSDAY
* WEAK WAVE PASSES N OF THE REGION FRIDAY
* STRONG HIGH PRESSURE TAKES OVER INTO EARLY NEXT WEEK

OVERVIEW AND MODEL PREFERENCES...
APPEARS THAT THE MEDIUM RANGE MODELS IN RATHER GOOD AGREEMENT AT
THE SURFACE AND ALOFT THROUGH MOST OF THIS PERIOD WITH ONLY MINOR
TIMING DIFFERENCES ACROSS THE EASTERN U.S...WHILE RATHER LARGE
DIFFERENCES WORK IN ACROSS THE WEST AND EASTERN PACIFIC MAINLY
INTO NEXT WEEKEND AND BEYOND. ACROSS THE LOWER 48...IT APPEARS
THAT ONCE THE H5 TROUGH TRAVERSES OUT OF THE GREAT LAKES INTO
NORTHERN NEW ENGLAND AND QUEBEC THU-FRI...THE OVERALL UPPER FLOW
TENDS TO FLATTEN OUT FROM THE PLAINS TO EASTERN SEABOARD. IT DOES
REMAIN SPLIT...WITH A WEAK SHORT WAVE MOVING ACROSS THE SOUTHERN
STREAM FRI-SUN.

OVER THE NORTHERN TIER STATES...THE UPPER PATTERN REMAINS FLAT WHILE
AT THE SURFACE...HIGH PRES WILL TAKE OVER ACROSS MOST OF THE EASTERN
U.S. BEGINNING LATE FRI-SAT THROUGH THE REMAINDER OF THE LONG TERM
PERIOD AND BEYOND. WHILE DRY AND SEASONABLE WEATHER IS EXPECTED...
MAY SEE TEMPS BEGIN TO RISE A BIT LATE IN THE PERIOD THOUGH TIMING
IS UNCERTAIN.

WITH MODEL SUITE AND ASSOCIATED ENSEMBLES IN RATHER GOOD AGREEMENT
ACROSS THIS REGION...LEANED THIS FORECAST TOWARD A BLEND OF THE 12Z
GFS/UKMET AND 00Z ECMWF WITH THE ECENS.

DETAILS...

THURSDAY...COLD FRONT WILL WORK OFFSHORE DURING THE MORNING WITH SCT
SHOWERS LINGERING ACROSS SE MA/S COASTAL RI. EXPECT THESE TO PUSH
OFFSHORE THOUGH CLOUDS MAY LINGER INTO THE AFTERNOON. HIGH PRES WILL
THEN BUILD INTO NORTHERN NEW ENGLAND DURING THE AFTERNOON...SO
EXPECT W-NW WINDS TO BRING DRIER AIR TO THE REGION.

ANOTHER SHORT WAVE WORKS E IN THE FAST UPPER FLOW OUT OF THE GREAT
LAKES. MAY SEE SOME CLOUDS WORK INTO S NH/N MA DURING THU NIGHT.

FRIDAY...AS THE SHORT WAVE WORKS ACROSS NORTHERN NEW ENGLAND...MOST
OF THE ENERGY AND MOISTURE WILL REMAIN WELL N OF THE REGION. MAY GET
CLIPPED WITH A LITTLE BIT OF THE SOUTHERN EXTENT OF THE PRECIP AREA.
HOWEVER...DRY AIR IN PLACE ALOFT WITH FAST W FLOW...SO NOT A LOT OF
PRECIP EXPECTED. HAVE SLIGHT CHANCE POPS MENTIONED DURING THE DAY
ACROSS S NH AND EXTREME N MA MAINLY N OF ROUTE 2. EXPECT HIGH PRES
TO BUILD ACROSS QUEBEC AND THE NORTHEAST BY FRI NIGHT.

SATURDAY-TUESDAY...LARGE HIGH PRES ANCHORS FROM NEWFOUNDLAND DOWN TO
THE MID ATLC COAST BY SAT...WHICH WILL KEEP DRY AND SEASONABLE
CONDITIONS IN PLACE FOR MOST OF THIS PERIOD. HIGH MAY START TO MOVE
OFFSHORE MON...WHICH MAY BRING MILDER TEMPS TOWARD THE END OF THE
PERIOD THOUGH TIMING IS STILL UNCERTAIN. HAVE KEPT SEASONABLY COOL
TEMPS GOING FOR NOW.

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

OVERVIEW...
MODERATE CONFIDENCE. NOT MUCH CHANGE IN CONDITIONS THROUGH EARLY
TONIGHT WITH MVFR CIGS ACROSS WESTERN NEW ENGLAND AND IFR CLOSER
TO COAST. STEADIER RAIN NOT EXPECTED TO GET MUCH FARTHER INLAND
THAN BOS-PVD LINE...THOUGH PATCHY DRIZZLE POSSIBLE AS FAR AS ORH.
E/NE WINDS GUST TO 25KT MAINLY NEAR COAST.

CONDITIONS SHOULD LOWER TO IFR/LIFR OVERNIGHT...AGAIN ESPECIALLY NEAR
COAST. POSSIBILITY OF ISOLD THUNDER AROUND CAPE COD AND ISLANDS
FROM MIDNIGHT UNTIL 8 AM WED.

EXPECT RAPID IMPROVEMENT TO VFR WED MORNING...POSSIBLY NOT UNTIL
MIDDAY ALONG IMMEDIATE COAST. SHOULD HAVE SEA BREEZES DEVELOP
EARLY TO MID AFTERNOON...A LITTLE LATER THAN USUAL.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. COULD SEE LOWER
CIGS/VSBYS THAN FCST THIS EVENING.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

OUTLOOK...THURSDAY THROUGH SUNDAY...

THURSDAY...MODERATE CONFIDENCE EARLY...THEN HIGH CONFIDENCE. EXPECT
VFR ACROSS CENTRAL AND WESTERN AREAS. FOR S COASTAL RI/SE MA...
AREAS OF MVFR-IFR CIGS/VSBYS THROUGH MID MORNING...THEN SHOULD
IMPROVE TO VFR BY MIDDAY EXCEPT FOR SE MA...CAPE COD AND THE
ISLANDS WHERE LOCAL MVFR MAY LINGER INTO THE AFTERNOON. THU
NIGHT...VFR.

FRIDAY-SUNDAY...HIGH CONFIDENCE. VFR THROUGH PERIOD. MAY SEE BRIEF
LOCAL MVFR IN ANY WIDELY SCT SHOWERS FRIDAY ACROSS S NH/N MA
MAINLY N OF ROUTE 2.

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

OVERVIEW...HIGH CONFIDENCE THROUGH WEDNESDAY NIGHT.

SCA REMAINS POSTED THROUGH MOST OF TONIGHT DUE TO 25KT WINDS AND
ROUGH SEAS...AND EXTENDED THEM INTO WED NIGHT FOR OUTER WATERS
WHERE SEAS WILL TAKE LONGER TO SUBSIDE.

RAIN/DRIZZLE CONTINUES THROUGH TONIGHT AS LOW PRESSURE HEADS SE OF
NANTUCKET. MOST OF RAIN AND LOWER VSBYS WILL BE FOCUSED AROUND
CAPE COD AND ISLANDS...WHERE ISOLATED THUNDER IS ALSO POSSIBLE
BETWEEN MIDNIGHT AND DAYBREAK WED.

WINDS AND SEAS DIMINISH WED. GRADIENT SHOULD BE WEAK ENOUGH FOR
LOCAL SEA BREEZES TO DEVELOP WED AFTERNOON...BEFORE SW FLOW
INCREASES AHEAD OF NEXT COLD FRONT LATER IN DAY. WINDS MAY REACH
25KT WED NIGHT BUT WITH MILDER AIR FLOWING OVER COOLER WATERS
CONFIDENCE IS LOW. EXPECT SCATTERED SHOWERS/ISOLATED THUNDER WITH
PASSAGE OF COLD FRONT WED NIGHT.

OUTLOOK...THURSDAY THROUGH SUNDAY...

THURSDAY...MODERATE CONFIDENCE. SMALL CRAFT WILL BE NEEDED. FRONT
MOVES OFFSHORE WITH WIND SHIFT TO W. MAY SEE GUSTS UP TO 25 KT
EARLY...THEN WILL DIMINISH. SCT SHOWERS/ISOLATED THUNDER MAINLY ON
THE OUTER WATERS. SEAS AOA 5 FT...SUBSIDING ON THE NEAR SHORE
WATERS THU NIGHT.

FRIDAY THROUGH SUNDAY...HIGH CONFIDENCE FRI-SAT...MODERATE
CONFIDENCE SUNDAY. HIGH PRES BUILDS IN WITH DRY WEATHER AND GOOD
VSBY. LEFTOVER 5 FT SEAS DURING FRI ON THE OUTER WATERS SHOULD
SUBSIDE FRI NIGHT.

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR ANZ230-
232>234-236.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT THURSDAY FOR ANZ231-235-
237-250-251-254>256.

$$
SYNOPSIS...EVT/JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...EVT
AVIATION...EVT/JWD
MARINE...EVT/JWD

AREA FORECAST DISCUSSION

NWS TAUNTON MA

301 PM EDT TUE APR 23 2013

.SYNOPSIS...
A COASTAL STORM TRACKING SOUTHEAST OF NANTUCKET WILL BRING A
CHILLY RAIN TO SOUTHEAST NEW ENGLAND THROUGH TONIGHT. DRIER AND
MILD WEATHER ARRIVES WED. A QUICK MOVING COLD FRONT WILL PASS
THROUGH WED NIGHT INTO THURSDAY. MAINLY DRY AND SEASONABLY COOL
WEATHER RETURNS FRIDAY AND INTO THE WEEKEND THANKS TO A STRONG
HIGH PRESSURE SYSTEM.

.NEAR TERM /THROUGH TONIGHT/...
3 PM UPDATE...

WESTERN EDGE OF RAIN SHIELD OVER CAPE COD AND ISLANDS HAVING HARD
TIME MAKING PROGRESS INLAND. HIGHER RESOLUTION RAP HAS A VERY GOOD
HANDLE ON RADAR TRENDS AND ONLY BRINGS MEASURABLE RAINFALL INTO RI
AND EASTERN MA THROUGH THIS EVENING...BUT ONLY A FEW HUNDRETHS AT
THAT. HEAVIEST RAINFALL WILL CONTINUE TO BE FOCUSED ON CAPE COD
AND ISLANDS. STILL HAVE POTENTIAL FOR ISOLATED THUNDER NEAR S
COAST AS UPPER TROUGH SWINGS THROUGH FROM MIDNIGHT TO DAYBREAK WED
AND AIRMASS DESTABILIZES ALOFT.

OTHERWISE CLOUDY SKIES EXPECTED THROUGHOUT REGION WITH SPOTTY
DRIZZLE AS FAR INLAND AS WORCESTER HILLS AND NW RI. USED A BLEND
OF GFS/NAM MOS FOR LOWS WHICH RANGE FROM MID 30S FAR NW TO MID 40S
SE.

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
SYSTEM WILL HEAD TO MARITIMES WED. MODELS DIFFER ON TIMING OF
ARRIVAL OF DRIER AIR WITH NAM A BIT SLOWER THAN OTHER MODELS...BUT
ALL SHOW ENOUGH DRYING BY MIDDAY TO ALLOW FOR AT LEAST PARTIAL
CLEARING...EVEN ALONG COAST. WE INDICATED CLEARING NEAR CT RIVER
VALLEY FIRST THING IN MORNING...AND BY MID TO LATE MORNING FARTHER
E. IT MAY TAKE UNTIL MIDDAY AROUND CAPE COD AND ISLANDS.

FORECAST HIGHS ARE A CHALLENGE AS NAM KEEPS MORE
CLOUDINESS/ONSHORE FLOW THAN GFS AND THEREFORE HAS COOLER
TEMPERATURES NEAR COAST. FAVORED WARMER GFS MOS WHICH YIELDS HIGHS
IN 60S COAST/70S INLAND.

SW FLOW SHOULD PREVENT TEMPERATURES FROM DROPPING MUCH WED NIGHT.
USED BLEND OF GFS/NAM MOS WHICH YIELDS LOWS IN 40S TO AROUND 50.

.LONG TERM /THURSDAY THROUGH MONDAY/...
HIGHLIGHTS...

* COLD FRONT WILL PUSH THROUGH WED NIGHT INTO THURS
* WEAK WAVE ON FRIDAY
* STRONG HIGH PRESSURE FOR THE WEEKEND

CONFIDENCE LEVEL/MODEL GUIDANCE...
HIGH CONFIDENCE IN FORECAST THROUGH THE WEEKEND. 00Z MODEL
GUIDANCE IS IN FAIRLY GOOD AGREEMENT ON PRECIPITATION TIMING AND
FRONTAL PASSAGES. HIGH CONFIDENCE THAT A COLD FRONT WILL PUSH
ACROSS SNE BY WED NIGHT INTO THURSDAY...MODERATE CONFIDENCE ON
PRECIPITATION AMOUNTS. UPPER LEVEL LOW ON FRIDAY WILL PUSH A WEAK
WAVE OVER THE NORTH HALF OF THE REGION. HIGH CONFIDENCE ON
BUILDING HIGH PRESSURE FROM FRIDAY EVENING INTO EARLY MONDAY
MORNING THANKS TO SURFACE HEIGHTS APPROX 2-3 STANDARD DEVIATIONS
IN BOTH THE GFS AND EC ENSEMBLES.

DETAILS...

WED NIGHT INTO FRIDAY...
STRONG UPPER LEVEL TROUGH WILL BRING TWO WAVES OF ENERGY THROUGH
SNE. THE FIRST WILL OCCUR WED NIGHT INTO THURS DEVELOPING A
SURFACE LOW NORTH OF VT/NH AND PUSHING IT NORTHEASTWARD. THIS WILL
DRAG A COLD FRONT ACROSS SNE WED NIGHT. THIS FRONT HOWEVER REALLY
LOSES ITS MOISTURE AS IT MOVES THROUGH THE INTERIOR. BELIEVE THE
BEST AREA TO SEE ACCUMULATING AMOUNTS WILL BE OUT WEST...WITH SCT
SHOWERS ACROSS THE CENTRAL PART OF THE CWA. AS WE GET CLOSER TO
THE EAST COAST...DEWPOINTS ARE A TAD HIGHER AND WITH SOUTHWESTERN
FLOW...MORE MOISTURE IS ADVECTING INTO THE MID-LEVELS...SO EXPECT
PRECIP TO BE MORE ABUNDANT ACROSS THE EAST COAST BY EARLY THURS
MORNING. EXPECTING LESS THAN A 0.25 INCHES OF PRECIP AS THIS FRONT
WILL BE MOVING QUITE QUICKLY. THERE IS A CHANCE FOR SOME ISOLATED
THUNDER WITH THIS SYSTEM...YET THE POSSIBILITY OF STRONG STORMS IS
QUITE LOW.

THE SECOND WAVE THAT ROUNDS THE TROUGH WILL MOVE THROUGH SNE BY
THURS NIGHT INTO FRIDAY MORNING. THIS SYSTEM AM LESS CONFIDENCE
ABOUT AS THERE IS PLENTY OF DRY AIR ALOFT AND HIGH PRESSURE IS
QUICKLY BUILDING BEHIND IT...PUSHING IT MORE NORTHWARD TOWARDS
NORTHERN NEW ENGLAND. BELIEVE THAT PERHAPS SCT SHOWERS ARE
POSSIBLE...BUT MORE LIKE SPRINKLES IN AREAS NORTH OF THE MASS PIKE.

THE WEEKEND...
AS THE TROUGH MOVES OFFSHORE...HIGH PRESSURE WILL BUILD IN FOR
THE WEEKEND. ZONAL FLOW ALOFT WILL TRY TO PUSH A FEW WAVES THROUGH
SNE...BUT BELIEVE THE AREA WILL BE TO DRY SO PERHAPS JUST PASSING
CLOUDS. THIS HIGH PRESSURE SEEMS TO BUILD OVER SNE FOR SOME TIME
AND MODELS ARE HAVING A HARD TIME ON WHEN TO PUSH IT OUT OF THE
REGION FOR EARLY NEXT WEEK. REGARDLESS...EXPECT MOST CLEAR SKIES
AND TEMPS IN THE MID TO UPPER 60S.

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

CONDITIONS SHOULD LOWER TO IFR/LIFR OVERNIGHT...AGAIN ESPECIALLY NEAR
COAST. POSSIBILITY OF ISOLD THUNDER AROUND CAPE COD AND ISLANDS
FROM MIDNIGHT UNTIL 8 AM WED.

EXPECT RAPID IMPROVEMENT TO VFR WED MORNING...POSSIBLY NOT UNTIL
MIDDAY ALONG IMMEDIATE COAST. SHOULD HAVE SEA BREEZES DEVELOP
EARLY TO MID AFTERNOON...A LITTLE LATER THAN USUAL.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. COULD SEE LOWER
CIGS/VSBYS THAN FCST THIS EVENING.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

OUTLOOK...THURSDAY THROUGH SUNDAY...

THURSDAY...MODERATE CONFIDENCE. VFR FOR THE MAJORITY...QUICK
MOVING COLD FRONT MAY LEAD TO MVFR/IFR IN SHOWERS. LOW PROB FOR
ISO TSRA. THE THREAT FOR MVFR/IFR LINGERS...ESPECIALLY EASTERN
HALF OF THE AREA INTO THURSDAY.

FRIDAY INTO SUNDAY...HIGH CONFIDENCE FOR VFR.

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

OVERVIEW...HIGH CONFIDENCE THROUGH WEDNESDAY NIGHT.

SCA REMAINS POSTED THROUGH MOST OF TONIGHT DUE TO 25KT WINDS AND
ROUGH SEAS...AND EXTENDED THEM INTO WED NIGHT FOR OUTER WATERS
WHERE SEAS WILL TAKE LONGER TO SUBSIDE.

OUTLOOK...THURSDAY THROUGH SUNDAY...

MODERATE CONFIDENCE THROUGH THE PERIOD.

THU...SCA WILL BE NEEDED. FRONTAL PASSAGE WITH WIND SHIFT FROM SW
TO NW. WINDS MAY GUST UP TO 30KTS AHEAD OF FRONT. THERE IS A
CHANCE OF SHOWERS WITH LOW PROB FOR ISO THUNDER. SEAS ABOVE 5 FT
WILL LINGER THROUGH THURSDAY AND INTO EARLY FRI.

FRI INTO SUNDAY...HIGH PRES BUILDS IN WITH DRY WEATHER AND GOOD VSBY.

$$
SYNOPSIS...EVT/JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...DUNTEN
AVIATION...EVT/JWD
MARINE...EVT/JWD

AREA FORECAST DISCUSSION

NWS TAUNTON MA

116 PM EDT TUE APR 23 2013

.SYNOPSIS...
A COASTAL STORM TRACKING SOUTHEAST OF NANTUCKET WILL BRING A
CHILLY RAIN TO EASTERN NEW ENGLAND TODAY AND INTO TONIGHT. DRIER
AND MILD WEATHER ARRIVES WED. A QUICK MOVING COLD FRONT WILL PASS
THROUGH WED NIGHT INTO THURSDAY. MAINLY DRY AND SEASONABLY COOL
WEATHER RETURNS FRIDAY AND INTO THE WEEKEND THANKS TO A STRONG
HIGH PRESSURE SYSTEM.

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
115 PM UPDATE...

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
ALL MODELS SHOW COASTAL LOW PRESSURE MOVING UP THROUGH 40N/70W AND
CONTINUING RAIN OVER OUR EASTERN AREAS. STABILITY
INDICES...ESPECIALLY THE TOTALS AND LI...SHOW POTENTIAL FOR
THUNDER OVER THE CAPE/ISLANDS AFTER MIDNIGHT AND EXTENDING OVER
EASTERN MASS/RI BY MORNING. SUCH CONVECTION WOULD INCREASE HOURLY
PCPN RATES AND INCREASE POOR DRAINAGE FLOODING POTENTIAL.

MODEL QPF CONTINUES TO FOCUS MOST OF THE PCPN OVER RI/EASTERN
MASS/MERRIMACK VALLEY OF NH. THIS CONSENSUS AND GEOGRAPHY...THE
WORCESTER HILLS...SUGGESTS A SHARP MOISTURE GRADIENT ON THE
WESTERN EDGE OF THE RAIN SHIELD.

THE LOW MOVES NORTHEAST TO THE MARITIMES LATE TUESDAY
NIGHT/WEDNESDAY. THE ECMWF AND GGEM ARE SLOWER IN DOING THIS THAN
ARE THE NAM AND GFS...BUT ALL SUGGEST A PERIOD OF DRYING AND
PARTIAL CLEARING ON WEDNESDAY. EQUIVALENT MIXING TEMPS OF 6-8C
WOULD SUPPORT MAX TEMPS IN THE UPPER 60S AND LOWER 70S.

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS...

* COLD FRONT WILL PUSH THROUGH WED NIGHT INTO THURS
* WEAK WAVE ON FRIDAY
* STRONG HIGH PRESSURE FOR THE WEEKEND

DETAILS...

.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

CONDITIONS SHOULD LOWER TO IFR/LIFR OVERNIGHT...AGAIN ESPECIALLYNEAR
COAST. POSSIBILITY OF ISOLD THUNDER AROUND CAPE COD AND ISLANDS
FROM MIDNIGHT UNTIL 8 AM WED.

EXPECT RAPID IMPROVEMENT TO VFR WED MORNING...POSSIBLY NOT UNTIL
MIDDAY ALONG IMMEDIATE COAST. SHOULD HAVE SEA BREEZES DEVELOP
EARLY TO MID AFTERNOON...A LITTLE LATER THAN USUAL.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. COULD SEE LOWER
CIGS/VSBYS THAN FCST THIS EVENING.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

OUTLOOK...THURSDAY THROUGH SUNDAY...

FRIDAY INTO SUNDAY...HIGH CONFIDENCE FOR VFR.

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

OVERVIEW...MODERATE TO HIGH CONFIDENCE THROUGH WEDNESDAY.

SMALL CRAFT ADVISORIES WILL CONTINUE INTO TONIGHT WITH EAST GUSTS
TO 30 KNOTS. THERE IS A LOW PROBABILITY OF GUSTS TO 35 KNOTS...BUT
NOT ENOUGH TO GO WITH GALES AT THIS TIME.

COASTAL LOW PRESSURE OFF THE CAROLINAS WILL MOVE UP THE COAST
TODAY AND TONIGHT. PERIODS OF HEAVY RAIN WILL REDUCE VSBYS ON THE
WATERS. WINDS SHIFT FROM EAST THROUGH NORTH TO WEST AS THE COASTAL
LOW PASSES OFFSHORE LATER TONIGHT AND WEDNESDAY. SMALL CRAFTS
LINGER ON THE SOUTHERN AND OUTER WATERS THROUGH WEDNESDAY EVENING.

BUILDING SEAS TODAY WITH ROUGH SEAS CONTINUING THROUGH WEDNESDAY.

OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY...

MODERATE CONFIDENCE THROUGH THE PERIOD.

WED NIGHT INTO THU...SCA WILL BE NEEDED. FRONTAL PASSAGE WITH WIND
SHIFT FROM SW TO NW. WINDS MAY GUST UP TO 30KTS AHEAD OF FRONT.
THERE IS A CHANCE OF SHOWERS WITH LOW PROB FOR ISO THUNDER. SEAS
ABOVE 5 FT WILL LINGER THROUGH THURSDAY AND INTO EARLY FRI.

FRI INTO SUNDAY...HIGH PRES BUILDS IN WITH DRY WEATHER AND GOOD VSBY.

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR ANZ230-
232>234-236.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR ANZ231-251.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT THURSDAY FOR ANZ235-237-
250-254>256.

$$
SYNOPSIS...WTB/DUNTEN
NEAR TERM...JWD
SHORT TERM...WTB
LONG TERM...DUNTEN
AVIATION...JWD
MARINE...WTB/DUNTEN

AREA FORECAST DISCUSSION

NWS DODGE CITY KS

220 PM CDT TUE APR 23 2013

...UPDATE TO LONG TERM...

.SYNOPSIS...
ISSUED AT 1210 AM CDT TUE APR 23 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 203 AM CDT TUE APR 23 2013

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 220 PM CDT TUE APR 23 2013

MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL TROUGH PUSHING ASHORE
INTO THE DESERT SOUTHWEST THURSDAY, THEN LIFTING NORTHEAST ACROSS
THE SOUTHERN ROCKIES THURSDAY NIGHT BRINGING THE POSSIBILITY FOR
SHOWERS AND THUNDERSTORMS TO CENTRAL AND PORTIONS OF WESTERN KANSAS
LATE THURSDAY NIGHT INTO FRIDAY. AS THE UPPER LEVEL SHORTWAVE LIFTS
INTO THE SOUTHERN ROCKIES, SURFACE HIGH PRESSURE IS EXPECTED TO
SHIFT FROM THE CENTRAL PLAINS EASTWARD INTO THE MISSISSIPPI RIVER
VALLEY HELPING SET UP A RETURN FLOW ACROSS THE WESTERN HIGH PLAINS
OF KANSAS. MODEST LOW LEVEL MOISTURE WILL ADVECT BACK INTO WESTERN
KANSAS WITH H85 DEWPOINTS IN EXCESS OF 5C NUDGING NORTHWARD INTO
SOUTH CENTRAL AND SOUTHWEST KANSAS. ADDITIONALLY, SURFACE TROUGHING
IS PROJECTED TO DEVELOP ACROSS EASTERN COLORADO LATE THURSDAY, THEN
ADVANCE INTO WESTERN KANSAS AS THE UPPER LEVEL SHORTWAVE EJECTS OUT
OF THE ROCKIES EARLY FRIDAY. ALONG WITH SOME UPSLOPING, THIS WILL
PROVIDE INCREASED LIFT IN THE LOWER LEVELS. ALTHOUGH INSTABILITY
WILL BE SLOW TO INCREASE, DYNAMIC SUPPORT ALOFT WILL BE FAVORABLE
ENOUGH TO SUPPORT SHOWER AND THUNDERSTORM DEVELOPMENT FROM THE
SOUTH PLAINS NORTHWARD INTO PORTIONS OF CENTRAL AND WESTERN KANSAS.
HOWEVER, WIDESPREAD SEVERE WEATHER IS NOT EXPECTED DUE TO A LACK
OF INSTABILITY AS INDICATED BY GFS/ECMWF MODEL SOUNDINGS. DRIER
CONDITIONS ARE LIKELY THROUGH THE WEEKEND AS A MORE ZONAL FLOW
ALOFT SETS UP ACROSS THE WESTERN HIGH PLAINS.

TEMPERATURES WILL REMAIN BELOW NORMAL THURSDAY EVEN AS A GRADUAL
WARMING TREND BEGINS EARLY IN THE PERIOD. AS MENTIONED BEFORE,
SURFACE HIGH PRESSURE IS PROJECTED TO DRIFT EAST OUT OF EASTERN
KANSAS INTO THE MISSISSIPPI RIVER VALLEY RETURNING A LOW LEVEL
SOUTHERLY FLOW TO WESTERN KANSAS. THIS WILL DRAW WARMER AIR
NORTHWARD INTO THE AREA WITH H85 TEMPERATURES RANGING FROM JUST
ABOVE 5C ACROSS CENTRAL KANSAS TO NEAR 15C ALONG THE COLORADO
BORDER. LOOK FOR HIGHS WELL UP INTO THE 60S(F) IN CENTRAL KANSAS TO
NEAR 70F IN EXTREME WESTERN KANSAS THURSDAY AFTERNOON. THE WARMING
TREND WILL CONTINUE INTO THE WEEKEND AS THE FLOW ALOFT BECOMES MORE
ZONAL. HIGHS IN THE 70S(F) ARE EXPECTED BY THIS WEEKEND WITH THE
LOWER TO MID 80S(F) NOT OUT OF THE QUESTION.

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1157 AM CDT TUE APR 23 2013

BOTH THE GCK AND HYS TAF SITES WILL START OUT WITH MVFR CIGS IN
THE OVC050 RANGE. LOWER CLOUDS ARE STILL PERSISTING AT THE DDC
SITE, DOWN AT THE BKN015 LEVEL. THERE IS A SLIGHT CHANCE FOR CIGS
IN THE BKN-OVC015 RANGE TO FORM AT THE HYS AND GCK SITES, BUT JUST
WENT WITH A TEMPO GROUP AT BOTH OF THOSE SITES. THE LOW LEVEL FLOW
FROM THE NORTH IS BRINGING SOME LOW LEVEL MOISTURE ACROSS WESTERN
KANSAS. BUT, AT THE SAME TIME, HIGH PRESSURE IS BUILDING IN FROM
COLORADO. EXPECT ALL THREE TAF SITES TO BE IN VFR CONDITIONS BY
03Z TONIGHT. WINDS WILL ALSO SIGNIFICANTLY DROP TO THE NORTHWEST
AT 7 OR 8 KNOTS AFTER SUNSET. BY MIDNIGHT OR SO, CLOUDS WILL
DISSIPATE.

.PRELIMINARY POINT TEMPS/POPS...
DDC 21 57 34 68 / 10 0 0 0
GCK 18 57 33 69 / 0 0 0 0
EHA 24 59 37 69 / 10 0 0 0
LBL 24 59 36 70 / 10 0 0 0
HYS 17 51 31 66 / 10 0 0 0
P28 23 57 36 66 / 10 0 0 0

.DDC WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING FROM 7 PM CDT /6 PM MDT/ THIS EVENING TO 8
AM CDT /7 AM MDT/ WEDNESDAY FOR KSZ030-031-043>046-061>066-
074>081-084>090.

SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...JJOHNSON
AVIATION...BURKE

AREA FORECAST DISCUSSION

NWS DODGE CITY KS

1205 PM CDT TUE APR 23 2013

...UPDATED FOR THE 18Z TAFS AND AVIATION SECTION...

.SYNOPSIS...
ISSUED AT 1210 AM CDT TUE APR 23 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 203 AM CDT TUE APR 23 2013

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 243 AM CDT TUE APR 23 2013

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1157 AM CDT TUE APR 23 2013

.PRELIMINARY POINT TEMPS/POPS...
DDC 32 22 58 34 / 50 10 0 0
GCK 31 20 58 33 / 80 0 0 0
EHA 35 24 60 37 / 30 10 0 0
LBL 35 24 60 36 / 30 10 0 0
HYS 32 19 55 31 / 80 10 0 0
P28 36 23 58 36 / 60 10 0 0

.DDC WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING FROM 7 PM CDT /6 PM MDT/ THIS EVENING TO 8
AM CDT /7 AM MDT/ WEDNESDAY FOR KSZ030-031-043>046-061>066-
074>081-084>090.

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

AREA FORECAST DISCUSSION

NWS GRAND RAPIDS MI

155 PM EDT TUE APR 23 2013

.SYNOPSIS...
ISSUED AT 400 AM EDT TUE APR 23 2013

.UPDATE...
ISSUED AT 859 AM EDT TUE APR 23 2013

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 400 AM EDT TUE APR 23 2013

.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 AM EDT TUE APR 23 2013

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 155 PM EDT TUE APR 23 2013

MAIN FOCUS OF THE 18Z FCSTS IS THE RAINFALL MOVING INTO THE AREA
AND THE TREND IN CONDITIONS WITH THE RAIN.

RAINFALL IS EXPANDING AND MOVING IN FROM THE SW THIS AFTERNOON. WE
EXPECT IT WILL HAVE SPREAD OVER ALL OF THE TERMINALS BY 21Z-22Z.
CONDITIONS UPSTREAM UNDER THE RAIN START OUT VFR...AND THEN DROP
DOWN INTO THE IFR CATEGORY UNDER THE CORE. WITH THIS IN MIND...WE
HAVE CONTINUED WITH SOME IFR CONDITIONS AT ALL LOCATIONS SPREADING
WEST TO EAST BEGINNING AROUND 21Z.

RAIN SHOULD THEN GRADUALLY END AFTER MIDNIGHT FROM W/SW TO E/NE.
MOST OF THE PCPN SHOULD REMAIN MAINLY RAIN BEFORE ENDING...HOWEVER
WE CAN NOT RULE OUT SOME SNOWFLAKES MIXING IN RIGHT AT THE END.
VSBYS SHOULD IMPROVE ONCE THE PCPN ENDS OVERNIGHT...BUT LOWER CIGS
IN MVFR CATEGORY WILL LIKELY HOLD ON UNTIL WED MORNING/EARLY
AFTERNOON.

.MARINE...
ISSUED AT 400 AM EDT TUE APR 23 2013

WILL GO AHEAD A ISSUE A SCA FOR TONIGHT INTO WED. COLD ADVECTION
AND BRISK NW WINDS BEHIND THE COLD FRONT WILL CAUSE ROUGH CONDITIONS.

.HYDROLOGY...
ISSUED AT 400 AM EDT TUE APR 23 2013

SMALLER STREAMS AND CREEKS WILL SEE RISES WITH THIS AFTERNOON/S AND
EVENING RAINS. THE LARGER RIVER WILL SEE THEIR FALL SLOWED BY THIS
RAIN...BUT MUCH OF ANY RISE ARE NOT EXPECTED.

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 4 PM EDT WEDNESDAY
FOR LMZ844>849.

UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...DUKE
AVIATION...NJJ
HYDROLOGY...JK
MARINE...JK

AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

1138 AM CDT TUE APR 23 2013

.UPDATE...

UPDATED TO LOWER TEMPERATURES AND CURRENT PRECIP TRENDS

.DISCUSSION...

VISIBLE SATELLITE IMAGERY THIS MORNING INDICATES A GOOD SNOW PACK
OVER THE NORTHWEST CWA AND THIS...ALONG WITH LOW LEVEL CAA...IS
EXPECTED TO REALLY LIMIT TEMPERATURES THIS AFTERNOON. WE HAVE
LOWERED HIGHS SEVERAL CATEGORIES INTO THE LOWER 30S IN THIS
AREA...AND THIS MAY NOT BE COLD ENOUGH. LOOKS LIKE A RECORD MIN
MAX IS LIKELY AT BOTH OMA/OFK TODAY. WE ALSO LOWERED HIGHS A TOUCH
IN THE SOUTHERN CWA WHERE THE CLOUDS/PRECIP ARE LIKELY TO HANG ON
A BIT LONGER. AS FAR AS PRECIP...RADAR TRENDS INDICATE A GENERAL
DECREASE IN THE HIGHER RETURNS IN THE SOUTH AND THIS TREND SHOULD
CONT THROUGH THE AFTERNOON. THE SOUTHERN CWA DOES REMAIN IN THE
RIGHT REAR ENTRANCE REGION OF THE AN UPPER LEVEL JET...AND THIS
FAVORABLE LARGE-SCALE FORCING FOR ASCENT MAY KEEP SOME SPRINKLES
OR FLURRIES GOING THROUGH THE AFTERNOON...THE ACCUMULATING
SNOWFALL IS OVER FOR THIS AREA.

NEW GRIDS/ZFP UPDATES HAVE ALREADY BEEN SENT.

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

MVFR CIGS CONT TO HANG ON AT LNK BUT VFR CONDS HAVE RETURN TO
OMA/OFK...AND THIS SHOULD BE THE GENERAL TREND THROUGH THE TAF
PERIOD AS WELL. GUSTY NORTHWEST WINDS WILL CONTINUE INTO THE EARLY
AFTERNOON BEFORE THE GUSTS DIMINISH...WITH SUSTAINED WINDS BELOW
12 KT BY EARLY THIS EVENING THROUGH THE END OF THE TAF PERIOD.

PREV DISCUSSION... /ISSUED 351 AM CDT TUE APR 23 2013/

DISCUSSION...
FORECAST CONCERNS TODAY WILL BE LIGHT SNOW POTENTIAL FOR SOUTHERN
PARTS OF CWA.

THE SURFACE COLD FRONT HAS PUSHED WELL TO THE SOUTH INTO SOUTHEAST
KANSAS AND NORTHWEST MISSOURI WITH SURFACE HIGH PRESSURE BUILDING
INTO THE REGION. AT H3...THE 120KT JET WAS OVERHEAD AND THE H5 TROF
FROM MONTANA TO NEVADA/UTAH STILL HAD 40DM HT FALLS WITH IT. THE
H3 JET WILL RE-CURVE SLIGHTLY NORTHEAST AS THE H5 TROF SWINGS
THROUGH THE PLAINS TODAY. THIS WILL STRENGTHEN THE MID LEVEL
FRONTOGENETIC FORCING IN NORTHEAST KANSAS AND H7 WARM AIR
ADVECTION BEFORE PUSHING EASTWARD THIS AFTERNOON. DRY LOW LEVELS
WILL BE UNDERCUTTING THE MOIST MID LEVELS...HOWEVER SOUTHEAST
NEBRASKA AND FAR SOUTHERN IOWA LOOKED TO BE CLIPPED WITH
PRECIPITATION WITH THIS STRONGER MID LEVEL FORCING. THE LATEST
WSR-88D MOSAIC HAS THE CONVECTION CLOSER TO THE FRONT OVER
SOUTHERN KANSAS WITH A BAND OF RAIN AND SNOW TRACKING NORTHEAST
ACROSS NORTHERN KANSAS. THE 03Z RAP/01Z HRRR AND LATEST 06Z
HRRR/07Z RAP HAVE BEEN CONSISTENT IN LIFTING SOME LIGHT SNOW INTO
SOUTHEAST NEBRASKA THIS MORNING AND SHIFT IT OUT OF THE AREA BY
18Z. WILL MAINTAIN HIGH PROB OF PRECIPITATION FOR FAR SOUTHEAST
NEBRASKA AND FAR SOUTHERN IOWA. FNB HAS BEEN REPORTING LIGHT RAIN
AND COLD AIR SHOULD CONTINUE TO DECREASE TEMPERATURES FOR A
CHANGEOVER TO SNOW. DID MENTION SOME LIGHT ACCUMULATIONS BEATRICE
TO CLARINDA SOUTHWARD WITH A DUSTING TO AN INCH OR SO AT
FNB...REDUCING THE CHANCES SIGNIFICANTLY AFT 18Z. BREEZY TO WINDY
NORTH WINDS AND COLD AIR ADVECTION TODAY WILL HOLD MOST LOCATIONS
TO THE UPPER 30S AND LOWER 40S.

SURFACE HIGH PRESSURE BUILDS IN TONIGHT WITH MOSTLY CLEAR...COLD
CONDITIONS AND DIMINISHING WINDS. TEMPERATURES WILL DROP INTO THE
20S FOR MOST SPOTS.

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

AREA FORECAST DISCUSSION

NWS WILMINGTON OH

147 PM EDT TUE APR 23 2013

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR MID/HIGH CLOUDS WILL CONTINUE TO THICKEN THIS AFTERNOON INTO
THE EVENING. THESE MAY BE HELPING TO KEEP WIND GUSTS DOWN AT THE
MOMENT BUT STILL EXPECT A FEW HOURS OF SOUTHERLY GUSTS OF 20-25 KT
DURING PEAK MIXING THIS AFTERNOON. AS MOISTURE AND LIFT INCREASE
LATE THIS AFTERNOON...A FEW SHOWERS MAY DEVELOP FROM WEST CENTRAL
INTO NORTH CENTRAL OHIO...CLOSE ENOUGH TO THE DAYTON AND COLUMBUS
SITES TO HAVE A FEW HOURS OF VCSH.

THE MAIN PERIOD OF AVIATION INTEREST WILL BE A COLD FRONTAL
PASSAGE LATE TONIGHT AND WEDNESDAY MORNING. VARIOUS COMPUTER MODEL
SOLUTIONS CONTINUE TO DIFFER WITH THE EXACT TIMING OF THE FRONTAL
PASSAGE. PUSHED TIMING BACK SLIGHTLY BUT MAINTAINED WX CONSISTENCY
WITH PREVIOUS FORECAST AND FIRST BROUGHT IN A VCTS ALONG THE
LEADING EDGE OF PRECIPITATION WHERE THERE WILL BE SOME LIMITED
INSTABILITY. NEAR AND JUST BEHIND THE FRONT...CEILINGS WILL LOWER
INTO THE MVFR RANGE AND BE ACCOMPANIED BY A PERIOD OF PREVAILING
RAIN SHOWERS AND MVFR VISIBILITY. WINDS WILL SHIFT FROM SOUTH TO
WNW WHILE MAINTAINING 10-15 KT SPEEDS. HAVE FRONTAL PASSAGE ACROSS
THE AREA BETWEEN 08-12Z. THE BACK EDGE OF PRECIPITATION WILL BEGIN
WORKING THROUGH THE TAF SITES AFTER 16Z.

OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE WEDNESDAY.

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.

$$
SYNOPSIS...CONIGLIO
NEAR TERM...SNYDER
SHORT TERM...CONIGLIO
LONG TERM...
AVIATION...SNYDER

AREA FORECAST DISCUSSION

NWS SIOUX FALLS SD

312 PM CDT TUE APR 23 2013

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 254 PM CDT TUE APR 23 2013

CLEAR SKIES ARE EXPECTED TO CONTINUE THROUGH THE EVENING HOURS
TONIGHT AS SURFACE HIGH PRESSURE BUILDS INTO THE AREA. WINDS ON THE
SURFACE WILL TURN WEST TO SOUTHWEST OVERNIGHT...THOUGH THE PRESSURE
GRADIENT DOESN`T BECOME ALL THAT LIGHT. AS SUCH...HAVE NUDGED
FORECAST LOWS UPWARD EVER SO SLIGHTLY...WITH WARMEST READINGS IN
MOST EXPOSED LOCATIONS. NAM FORECAST SOUNDINGS INDICATE POTENTIAL
FOR FOG...BUT THIS IS NOT SUPPORTED BY THE RAP SOUNDINGS. HRRR IS
DOWN FOR MAINTENANCE...BUT IN GENERAL...THINK THE WINDS WILL STAY UP
ENOUGH TONIGHT THAT FOG WILL NOT BE THAT BIG OF A CONCERN.

SHORTWAVE DROPS SOUTHEAST ACROSS THE REGION ON WEDNESDAY. MODELS
SUGGEST THAT SOME OF THE INITIAL DYNAMICS WILL BE LOST TO SATURATING
THE NEAR SURFACE LAYER. TOUGH CALL ON PRECIPITATION TYPE WHICH WILL
BE CONTROLLED BY SURFACE TEMPERATURES AS THIS IS THE ONLY LOCATION
IN THE THERMO PROFILE THAT IS POTENTIALLY ABOVE FREEZING. HAVE A
MIX OF SNOW AND RAIN ALONG THE HIGHWAY 14 CORRIDOR IN THE LAT
MORNING INTO THE EARLY AFTERNOON...BUT IN GENERAL PRECIPITATION
SHOULD PRIMARILY FAVOR RAIN WHICH IS SUPPORTED BY SREF PROFILES.
PROFILES ARE WEAKLY UNSTABLE ALOFT...AND GIVEN THIS IS THE
CASE...THE POTENTIAL EXISTS FOR RAIN OR SNOW SHOWERS TO DEVELOP IN
THE AFTERNOON HOURS. IF THE INTENSITY WAS TO GET STRONG
ENOUGH...THEN MAY BE ABLE TO GET BRIEF SNOW SQUALLS IN HIGHER
INTENSITY PRECIPITATION BANDS. IN GENERAL...EXPECT PRECIPITATION
AMOUNTS TO BE FAIRLY LIGHT...WITH A FEW HUNDREDTHS OF AN INCH OR
LESS IN MOST LOCATIONS. APPEARS TO BE QUITE BREEZY WITH 20-30 KNOTS
OF FLOW AT 925 HPA COMBINED WITH LOW LEFT COLD AIR ADVECTION AIDING
IN MIXING.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 254 PM CDT TUE APR 23 2013

THE TAIL END OF THE WAVE WILL BE MOVING THROUGH EARLY ON WEDNESDAY
EVENING MAY ALLOW FOR A FEW STRAGGLING SHOWERS IN THE FAR EASTERN
CWA...OTHERWISE CLEARING SKIES AND LIGHTER WINDS SHOULD ALLOW FOR
A COOL NIGHT AS NORTHWEST WINDS RELAX TO WEST AND SOUTHWEST. LOWS
SHOULD MAINLY BE IN THE 20S WITH A FEW TEENS POSSIBLE AREAS WITH
DEEPER SNOW COVER.

THURSDAY WILL PROVE TO BE A DECENT SNOW MELTING DAY WITH MOSTLY
SUNNY TO PARTLY CLOUD CONDITIONS AND MILDER READINGS. LOW LEVEL
WIND DIRECTION AND THE LOCATION OF THE INCOMING WARM FRONT WILL
PLAY A BIG ROLE ON WHERE THE BEST WARMING WILL BE. WILL AIM FOR
THE WARMEST READINGS WEST OF THE JAMES RIVER VALLEY WHERE THE BEST
CHANCE RESIDES OF WINDS BECOMING SOUTH OR SLIGHTLY SOUTHWEST. THE
FARTHER EAST FROM HERE THE BETTER CHANCE THAT A SOUTHEAST
COMPONENT WILL HANG IN. WILL HAVE HIGHS RANGING FROM 60 TO 65 WEST
OF THE JAMES TO AROUND 50 NORTH AND EAST OF A BROOKINGS TO JACKSON
LINE.

THURSDAY NIGHT INTO FRIDAY WILL SEE A SOUTHERLY WIND TURNS A BIT
SOUTHWEST WHICH WILL BRING THE PROBABILITY FOR MUCH WARMER
READINGS AND LIKELY THE FINAL DAY WITH ANY REAL SNOW COVER LEFT ON
THE GROUND. NOT PLANNING ON THE SNOW COVER HAVING MUCH OF AN
EFFECT SO WILL GO WITH HIGHS MAINLY IN THE 60S.

THE BIG WARM UP IS STILL ON TAP THIS WEEKEND AND WILL CONTINUE TO
KEEP ABOVE NORMAL TEMPERATURES GOING. THE MAIN DIFFERENCES IN THE
MODELS SHOW UP AROUND MONDAY WHERE THE GFS DIVES COLDER AIR SOUTH
AS A FAIRLY STRONG TROUGH MOVES THROUGH NORTH DAKOTA. THE ECMWF
AND THE EXTRAPOLATED GEM ARE LESS BOISTEROUS WITH THIS WAVE AND
MORE OR LESS RIDE THE ENERGY ALONG AND NORTH OF THE PERIPHERY OF
THE RIDGE...KEEPING THE WARM AIR IN PLACE THROUGH TUESDAY. WILL
STICK CLOSEST TO THE GEM/ECMWF OUTPUT WHICH SEEMS MORE REASONABLE
AND THE GFS IS LIKELY PUSHING THE TROUGH TO AGGRESSIVELY THROUGH
THE EXISTING RIDGE. NOT PLANNING ON ANY REAL ISSUES WITH
PRECIPITATION DURING THIS TIME FRAME.

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1223 PM CDT TUE APR 23 2013

VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SURFACE HIGH
PRESSURE WILL BUILD INTO THE AREA OVERNIGHT LEADING TO LIGHT
WINDS. MODEL SOUNDINGS SUGGEST THE POTENTIAL FOR FOG...BUT DID NOT
INCLUDE MENTION WITH ONLY LIMITED SNOW MELT EXPECTED TODAY.
SOUTHWEST WINDS INCREASE AHEAD OF NEXT WAVE DROPPING DOWN IN
NORTHWEST FLOW. PRECIPITATION IS EXPECTED TO DEVELOP AROUND KHON
AROUND 18Z...SPREADING SOUTHEAST THROUGH THE AFTERNOON.

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

SHORT TERM...
LONG TERM...08
AVIATION...