Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 03/29/12
AREA FORECAST DISCUSSION
NWS TAUNTON MA
721 PM EDT WED MAR 28 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE ACROSS NEW ENGLAND THIS EVENING THEN EXIT
TO THE EAST DURING THURSDAY. COOL AND DRY WEATHER FOLLOWS
FRIDAY...WITH ANOTHER LOW PRESSURE LIKELY TO MOVE SOUTH OF OUR
REGION DURING THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
7PM UPDATE...
DRY SLOT HAS MOVED OVER THE AREA AS LOW PRES BEGINS TO MOVE OVER
FROM THE NW. THIS SHOULD KEEP MUCH OF THE REGION DRY SAVE FOR WRN
MA AND SRN NEW HAMPSHIRE FOR MUCH OF THE OVERNIGHT. WRN MA SHOWERS
WILL LIKELY DISSIPATE SOMEWHAT SINCE THEY WERE TRIGGERED OVER ERN
NY ON THE NOSE OF SOME MARGINAL INSTABILITY. THE COLUMN STABILIZES
SIGNIFICANTLY AS ONE MOVES E INTO SRN NEW ENGLAND. HRRR WAS
HANDLING THIS WELL BUT HAS STRUGGLED WITH INITIALIZATION ISSUES
THE LAST COUPLE OF HOURS...OVERNIGHT POPS/SKIES WERE A SERIES OF
HAND EDITS TO REFLECT CURRENT TRENDS. OTHERWISE...EXPECT MORE
WIDESPREAD SHOWERS ESPECIALLY OVER N AND ERN AREAS WITH A COLD
FROPA DURING THE MORNING THU. ALSO ADJUSTED TEMPS/DWPTS TO REFLECT
TRENDS.
PREVIOUS DISCUSSION...
HRRR MODEL DID A GREAT JOB WITH TIMING AND AREAL COVERAGE OF
THE SHOWERS WHICH ARE EXITING THE ISLANDS AND NOW INDICATES A FEW
SHOWERS MAY DEVELOP LATE AFTERNOON ACROSS THE INTERIOR. CLEARING
SKIES ARE MOVING INTO W ZONES AND SHOWERS ARE DEVELOPING ACROSS
CENTRAL NEW YORK STATE. SPC MESOANALYSIS SHOWS THAT SFC BASED
INSTABILITY IS CONFINED TO WESTERN NY WHILE STEEPEST MID LEVEL
LAPSE RATES ARE OVER THE MID ATLC COAST. SNE IS UNDER COOL STABLE
REGIME WITH WARM FRONT TO THE SW SO WHILE A FEW SHOWERS ARE
POSSIBLE LATE AFTERNOON/EVENING...THUNDER NOT EXPECTED.
OTHERWISE...MID LEVEL SHORTWAVE AND ASSOCD LOW PRES WILL BE MOVING
ACROSS CENTRAL NEW ENG THIS EVENING THEN E OF NEW ENG LATER
TONIGHT. MOST OF THE SHOWER ACTIVITY SHOULD BE CONFINED TO NORTH
OF THE LOW TRACK WHICH PLACES IT ACROSS N NEW ENG. HOWEVER...A FEW
SHOWERS POSSIBLE LATER TONIGHT AS OCCLUSION SWINGS THROUGH AND
DEEPER MOISTURE MOVES IN FROM THE NORTH. WE WILL CARRY LOW CHC
POPS BUT MOST OF THE NIGHT WILL LIKELY BE DRY.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THURSDAY...
LOW PRES EXITS TO THE EAST BUT STILL CANT RULE OUT A FEW SHOWERS
ACROSS E NEW ENG WHERE DEEPER MOISTURE EXISTS UNDER MOIST CYCLONIC
FLOW. OTHERWISE...A MOCLDY AND COOL DAY EXPECTED WITH PARTIAL
CLEARING MOVING INTO W ZONES LATER IN THE AFTERNOON. MAX TEMPS
WILL RANGE FROM MID 40S TO LOWER 50S...WITH MILDEST READINGS IN
THE CT VALLEY.
THURSDAY NIGHT...
CLEARING SKIES EXPECTED FROM WEST TO EAST AS HIGH PRES BUILDS TO
THE N. MID LEVEL SHORTWAVE ROTATING SWD FROM QUEBEC EXPECTED TO
PASS NE OF SNE. USED THE BIAS CORRECTED GUIDANCE TO DERIVE MIN
TEMPS.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
HIGHLIGHTS...
* DRY FRI INTO FRI NIGHT
* A WEATHER DISTURBANCE LOOKS TO STAY S OF THE REGION DURING THE WEEKEND
OVERVIEW AND MODEL PREFERENCES...
DESPITE EARLY AGREEMENT IN LATEST MODEL GUIDANCE FOR
FRI...SYNOPTIC PATTERN REMAINS UNCERTAIN FOR THE WEEKEND INTO
EARLY NEXT WEEK. AS SUCH...THERE IS GENERALLY LOWER THAN NORMAL
CONFIDENCE IN SENSIBLE WX DETAILS. FOR THE MID ATLANTIC/S COASTAL
SYSTEM OVER THE WEEKEND...THERE ARE ESSENTIALLY TWO CAMPS...THE
WEAKER/DRIER GFS/NAM AND THE MORE ROBUST/WETTER ECMWF/CMC. SRN NEW
ENGLAND ESSENTIALLY LIES AT THE POINT OF INFLECTION BETWEEN
RIDGING IN GREAT LAKE REGION...AND THE BASE OF A LONGWAVE
TROF/CUTOFF OVER THE MARITIMES. THIS PRODUCES GENERALLY WNW
PROGRESSIVE FLOW OVER THE AREA...WHICH IS GENERALLY WELL AGREED
UPON. THE MORE ROBUST CAMP...ATTEMPTS TO CREATE A DEEPER SRN
STREAM SHORTWAVE...WHILE THE WEAKER CAMP HAS A MUCH FASTER MOVING
AND WEAKER NRN STREAM WAVE. THE PROGRESSIVE AND NEAR ZONAL FLOW
WOULD SUPPORT THE WEAKER/DRIER SUITE OF MODELS...BUT GIVEN THAT
RECENT WV IMG SHOWS THIS SRN STREAM TROF JUST COMING ONSHORE ON
THE W COAST...AND ECMWF HAS SHOWN BETTER SKILL WITH THESE TYPES OF
FEATURES...WILL AT LEAST CARRY SOME POPS IN THIS FCST. THIS SOLN
WILL SUGGEST MORE WIDESPREAD PRECIP THAN THE NAM/GFS SOLN.
HOWEVER...IT SHOULD BE NOTED THAT EXACT SENSIBLE DETAILS REMAIN
MOSTLY SPECULATIVE. INTO NEXT WEEK...A SECONDARY SHORTWAVE LOOKS
TO PRIMARILY EFFECT NRN NEW ENGLAND...FOLLOWED BY ANOTHER AND
POSSIBLY STRONGER CUTOFF/SYSTEM BY MID WEEK.
DETAILS...
FRI INTO FRI NIGHT...
COOL HIGH PRES WILL BE WEAKENING AND SLIDING E OF THE AREA
THROUGH THE DAY AND EARLY IN THE OVERNIGHT. SOUNDINGS SUGGEST
FAIRLY DRY COLUMN WITH SUBSIDENCE INVERSION IN PLACE...WITH DRY WX
EXPECTED. THE NEARLY CLEAR SKIES DURING THE DAY SUPPORT MIXING
REACHING H85 AT LEAST...WITH RISING TEMPS AT THIS LVL TO AROUND
-5C. THIS SUPPORTS SOME AREAS REACHING THE LOW TO MID 50S FOR
HIGHS ON FRI.
SAT AND SUN...
AS MENTIONED IN THE MODEL DISCUSSION ABOVE...CONFIDENCE REMAINS
LOW TO MODERATE IN SENSIBLE WX DETAILS THROUGH THIS PERIOD DUE TO
SIGNIFICANT SPLITTING OF SOLNS BETWEEN MODELS. SHOULD THE WEAKER
GFS/NAM SOLNS VERIFY...THE REGION WOULD SEE MOSTLY INCREASING
CLOUDS SAT...BUT MOSTLY DRY WX WITH CLEARING SUN. SHOULD THE
ECMWF/CMC VERIFY. THERE WOULD BE A GREATER CHANCE FOR WETTING
PRECIP ESPECIALLY S OF THE MASS PIKE...AND THE BEST TIMING WOULD
BE MORE SAT NIGHT INTO SUN. GIVEN THAT ECMWF/CMC SUPPORT MORE OF A
SRN STREAM WAVE...WHERE AS GFS IS LIKELY TOO FOCUSED ON FAST
MOVING WAVE IN CONFLUENT FLOW WILL FAVOR MORE WIDESPREAD PRECIP
THAN THE GFS/NAM CURRENTLY SHOW. WILL GO WITH PROLONGED PERIOD OF
SLIGHT TO CHANCE POPS WITH THE PRIMARY FOCUS BEING SRN PORTIONS OF
THE FA. GIVEN THAT ALL MODELS SUPPORT OFFSHORE STRENGTHENING OF THE
LOW PRES WITH DEEPENING SHORTWAVE...FEEL AT LEAST SOME POPS ARE
WARRANTED. COLUMN LOOKS GENERALLY WARM ENOUGH FOR ANY
SHOWERS/STRATIFORM PRECIP TO REMAIN AS MOSTLY RAIN THROUGH THE
DURATION...ALTHOUGH A LITTLE BIT OF WINTRY PRECIP CANNOT BE RULED
OUT IN THE N AND W ZONES...ESPECIALLY IN THE COOLER AIR DURING
PRECIP ONSET.
SUN NIGHT...
DESPITE THE MODEL DIFFERENCES EARLIER IN THE WEEKEND. WEAK
RIDGING IS PROGGED TO ALLOW HIGH PRES TO BUILD BRIEFLY OVER THE
AREA WITH MOSTLY DRY CONDITIONS.
MON INTO MON NIGHT...
WITH RIDGE BUILDING FROM THE SW...TIME-MEAN JET SHIFTS TO THE
N...ALLOWING A SECOND WAVE TO EFFECT PRIMARILY NRN NEW ENGLAND.
WILL STILL SUGGEST AT LEAST SLIGHT CHANCE POPS..ESPECIALLY OVER
THE N.
TUE INTO WED...
AFTER A BRIEF DRYING PERIOD OF HIGH PRES...GUIDANCE FAVORS A MORE
ROBUST SYSTEM ASSOCIATED WITH SLOW MOVING CUTOFF FROM THE CENTRAL
CONUS. THIS WOULD INCREASE PRECIP CHANCES INTO THE DAY ON WED.
THERE ARE STILL MANY MORE DETAILS TO BE WORKED OUT ON THIS.
&&
.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
TONIGHT...
MODERATE CONFIDENCE. MOSTLY VFR TO START THE NIGHT WITH THE
EXPECTATION THAT CAPE/ISLANDS/NRN MA AND SRN NH TERMINALS WILL DIP
BACK TO MVFR ESPECIALLY AFTER MIDNIGHT AND SHOWER COVERAGE BECOMES
MORE WIDESPREAD. LOWER CONFIDENCE THAT INTERIOR AND SRN MA/RI/CT
TERMINALS DIP TO MVFR. WINDS SHIFTING FROM THE S TO THE WNW.
THURSDAY...
MODERATE CONFIDENCE. AREAS OF MVFR CIGS IN THE
MORNING...ESPECIALLY E OF CT VALLEY WITH SOME SHOWERS POSSIBLE.
THEN CIGS LIFTING TO VFR IN THE AFTERNOON. A COLD FRONT WILL
APPROACH WITH WINDS SHIFTING MORE TO THE N BEHIND THE FRONT.
THURSDAY NIGHT...
MODERATE TO HIGH CONFIDENCE VFR AFTER REMNANT SHOWERS...LOWER CIGS
DISSIPATE.
KBOS TERMINAL...
MODERATE CONFIDENCE IN TAF. VFR FOR THE NEXT SEVERAL HOURS DUE TO
CLEARING...HOWEVER EXPECT A RETURN OF MVFR CIGS TOWARD
MORNING...LOWER CONFIDENCE IN THE EXACT TIME OF THIS. SHOWERS
POSSIBLE WITH LOWER VSBYS DURING THE MORNING HOURS AS WELL.
CONDITIONS GRADUALLY IMPROVE DURING THE DAY THURSDAY. WINDS
TONIGHT WILL SHIFT TO THE WNW...THEN MORE TO THE NE AFTER THE
FRONTAL PASSAGE AROUND MID DAY.
OUTLOOK...FRIDAY THROUGH MONDAY...
FRIDAY... HIGH CONFIDENCE VFR.
FRIDAY NIGHT INTO THE WEEKEND...
LOW CONFIDENCE TO MODERATE CONFIDENCE. THERE ARE STILL SOME
QUESTION-MARKS REGARDING HOW CLOSE AN AREA OF LOW PRES PASSES TO
THE S COAST THROUGH THE WEEKEND...AND THE TIME IN WHICH IT DOES
SO. IF THE LOW MOVES FURTHER N...SHOWERS AND A FEW SNOW SHOWERS
WOULD BE MORE WIDESPREAD WITH THE POSSIBILITY OF MORE MVFR
CONDITIONS. HOWEVER...IF IT MOVES FURTHER S MUCH MORE OF THE AREA
WILL BE VFR. AT THIS TIME...THE BEST CHANCE FOR ANY OCCASIONAL
MVFR/IFR CONDITIONS WOULD BE TERMINALS S OF THE MASS PIKE LATE SAT
INTO SUN...WHILE NRN TERMINALS HAVE THE BETTER CHANCE OF REMAINING
VFR MOST OF THE TIME. EXPECTING MOSTLY N WINDS AS THE LOW
PASSES...WITH WINDS SHIFTING MORE ELY NEAR THE E COAST.
MONDAY...
AFTER A BRIEF DRY PERIOD SUN NIGHT INTO MON...POSSIBLE ANOTHER QUICK
MOVING DISTURBANCE WILL BRING SHOWERS TO THE TERMINALS DURING DAY
MON WITH ISOLATED MVFR CONDITIONS. LOW TO MODERATE CONFIDENCE.
&&
.MARINE...
6PM UPDATE...
WINDS HAVE DIMINISHED IN THE LAST HOUR SUCH THAT THE SMALL CRAFT
ADVISORY FOR VINEYARD SOUND...MARTHAS VINEYARD...AND NARRAGANSETT
BAY HAS BEEN DROPPED.
SW WINDS WILL DIMINISH THROUGH THIS EVENING...THEN SHIFT TO THE
NW THEN N AFTER MIDNIGHT...WITH GUSTS TO 25 KT DEVELOPING LATE
TONIGHT AND THU MORNING AS LOW PRES INTENSIFIES EAST OF THE
WATERS. WINDS MAY TEMPORARILY DECREASE THU AFTERNOON THEN ANOTHER
PULSE OF NEAR 25 KT NW WIND GUSTS EXPECTED THU NIGHT...ESPECIALLY
OVER EASTERN WATERS ASSOCD WITH A REINFORCING SHOT OF COLDER AIR.
SMALL CRAFT ADVISORIES CONTINUE.
OUTLOOK...FRIDAY THROUGH MONDAY...
FRIDAY...
NW WINDS WITH GUSTS TO 30 KT DURING THE MORNING HOURS WILL
GRADUALLY DIMINISH DURING THE DAY. SEAS OF 5 TO 7 FT WILL ALSO
GRADUALLY SUBSIDE THROUGH THE DAY. SMALL CRAFT ADVISORIES WILL
LIKELY BE ENDING THROUGH THE DAY AS A RESULT.
FRIDAY NIGHT INTO THE WEEKEND...
STORM SYS IS EXPECTED TO BECOME ORGANIZED AND DEEPEN AS IT PASSES
THRU THE MID-ATLANTIC AND OFFSHORE JUST S OF NEW ENGLAND. THERE
IS STILL SOME UNCERTAINTY IN HOW CLOSE AN AREA OF LOW PRES GETS TO
THE SRN WATERS SAT INTO SAT NIGHT. EXPECT THAT GENERALLY QUIET
BOATING WEATHER INTO THE DAY SUN. WINDS WILL INCREASE...ALONG WITH
WAVES AS THE LOW MOVES OFFSHORE DURING THE DAY SUN...SCA MAY BE
NEEDED FOR THAT DAY.
MONDAY...
GUSTY WINDS AND SEAS 5 TO 6 FT /ESPECIALLY OVER SRN WATERS/ WILL
CONTINUE INTO EARLY MONDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 8 PM EDT THURSDAY FOR ANZ231-
251.
SMALL CRAFT ADVISORY UNTIL NOON EDT THURSDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY FROM 4 AM TO 8 PM EDT THURSDAY FOR ANZ250-
254.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR ANZ255-256.
&&
$$
SYNOPSIS...KJC/DOODY
NEAR TERM...KJC/DOODY
SHORT TERM...KJC
LONG TERM...DOODY
AVIATION...DOODY
MARINE...KJC/DOODY
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
119 AM EDT TUE MAR 27 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION EARLY TODAY WITH HIGH PRESSURE
DOMINATING THROUGH WEDNESDAY. ANOTHER COLD FRONT WILL MOVE THROUGH
THURSDAY...FOLLOWED BY ANOTHER AREA OF HIGH PRESSURE BUILDING TO
THE NORTH FRIDAY. AN AREA OF UNSETTLED WEATHER WILL APPROACH FROM
THE WEST FOR THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
27/04Z SURFACE OBSERVATIONS SHOW A WELL-DEFINED BACKDOOR COLD
FRONT DROPPING QUICKLY SOUTH INTO THE MYRTLE BEACH AREA. THE FRONT
IS ON TARGET TO CROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST
GEORGIA OVERNIGHT...REACHING THE ALTAMAHA RIVER BY SUNRISE. THE
FRONT WILL PASS THROUGH WITH LITTLE FANFARE...BUT MAY BE ACCOMPANIED
BY A LITTLE STRATOCUMULUS AND A NOTICEABLE DROP IN DEWPOINTS. LATE
EVENING TEMPERATURES WERE GENERALLY RUNNING A FEW DEGREES COOLER
THAN EXPECTED...SO NUDGED LOWS DOWN IN A FEW AREAS...ESPECIALLY IN
THE I-95 CORRIDOR FROM SAVANNAH SOUTH TO DARIEN. LOWS WILL RANGE
FROM AROUND 50 FOR THE ZONES BORDERING THE CSRA AND SOUTHERN
MIDLANDS TO THE UPPER 50S AT THE BEACHES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
TUESDAY...THE DRY COLD FRONT WILL CONTINUE TO PRESS SOUTHWARD
TUESDAY MORNING INTO TUESDAY AFTERNOON...RESULTING IN NOTICEABLY
COOLER HIGH TEMPERATURES COMPARED TO PREVIOUS DAYS. MODERATE
NORTHEAST FLOW BEHIND THE DESCENDING FRONT WILL CREATE A DECENT
NORTH/SOUTH TEMPERATURE GRADIENT. EXPECT AFTERNOON TEMPERATURES TO
BE SUPPRESSED AROUND 70 DEGREES ACROSS THE NORTHERN FORECAST
AREA...WHILE RISING INTO THE UPPER 70S NEAR THE ALTAMAHA RIVER IN
SOUTHEAST GEORGIA. SURFACE HIGH PRESSURE WILL SETTLE INTO THE MID
ATLANTIC AND SOUTHEAST STATES IN THE WAKE OF THE FRONT BY TUESDAY
NIGHT. THE RESULTING WEAK PRESSURE GRADIENT AND LIGHT WINDS WILL
ENHANCE RADIATIONAL COOLING UNDER MOSTLY CLEAR SKIES...SUPPORTING
MORE SEASONAL LOW TEMPERATURES RANGING FROM THE UPPER 40S NORTH TO
THE LOWER 50S SOUTHEAST GEORGIA.
WEDNESDAY...SURFACE HIGH PRESSURE WILL CONTINUE TO DESCEND
SOUTHWARD AND SLIP OFF THE COAST INTO THE ATLANTIC WATERS ON
WEDNESDAY. EXPECT A MORE SOUTHERLY FLOW TO DEVELOP BY THE
AFTERNOON HOURS...AND UNDER MOSTLY SUNNY TO PARTLY CLOUDY
SKIES...HIGH TEMPERATURES WILL TREND WARMER IN THE UPPER 70S TO
LOWER 80S AWAY FROM THE LOCALLY COOLER COASTLINE. LOW TEMPERATURES
WILL ALSO MODERATE WEDNESDAY NIGHT WITHIN THE WARMER FLOW AND
HIGHER DEWPOINTS.
THURSDAY...SHORTWAVE ENERGY AND AN ASSOCIATED SURFACE LOW WILL
MOVE FROM THE GREAT LAKES REGION INTO THE NEW ENGLAND STATES
WEDNESDAY NIGHT INTO EARLY THURSDAY...PULLING A TRAILING COLD
FRONT SOUTHWARD THROUGH THE MID ATLANTIC AND SOUTHEAST STATES
LATER IN THE DAY. LATEST NUMERICAL MODEL SOLUTIONS SUGGEST LOW AND
MID LEVEL FLOW WILL GENERALLY REMAIN WEST DURING FRONTAL
PASSAGE...EVIDENCE THAT THE SYSTEM WILL BE LACKING A DECENT TAP
INTO DEEPER MOISTURE. RAIN POTENTIAL THUS APPEARS QUITE LIMITED ON
THURSDAY AND PREFER TO KEEP RAIN CHANCES BELOW 15 PERCENT AT THIS
POINT. SINCE THE WIND SHIFT ASSOCIATED WITH THE PASSING FRONT WILL
BE DELAYED UNTIL THURSDAY EVENING...TEMPERATURES ARE EXPECTED TO
WARM INTO THE LOWER 80S AWAY FROM THE COAST WITHIN SOME PRE-FRONTAL
COMPRESSION.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE WEAK FRONT WILL CONTINUE TO PUSH THROUGH THE AREA FROM NORTH TO
SOUTH THURSDAY NIGHT...SETTLING SOUTH OF THE AREA ON FRIDAY. ANOTHER
AREA OF HIGH PRESSURE WILL THEN BUILD OVER THE NORTHEAST STATES.
AFTER A WARM-UP MID WEEK...TEMPERATURES WILL COOL DOWN AGAIN BY A
FEW DEGREES.
RIGHT NOW...THE WEEKEND LOOKS UNSETTLED. AN AREA OF SHORTWAVE ENERGY
THAT COMES ASHORE IN SOUTHERN CALIFORNIA MID WEEK WILL WORK ITS WAY
ACROSS THE SOUTHERN TIER OF THE U.S. AND APPROACH FROM THE LOWER
MISSISSIPPI VALLEY LATER SATURDAY INTO SUNDAY. TIMING AND DETAILS
ARE TOO TOUGH TO PIN DOWN THIS FAR OUT...BUT WE WILL DEFINITELY SEE
AN INCREASE IN CLOUDS AND CHANCES OF RAIN FOR SATURDAY AFTERNOON
INTO SUNDAY...WITH SOME IMPROVING CONDITIONS POSSIBLE BY MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
VFR THROUGH 06Z/28 AT KCHS/KSAV. COLD FRONT TIMED TO CROSS
KCHS AROUND 07Z/27 AND KSAV AROUND 10Z/Q7. GUSTY NE SURFACE WINDS
LIKELY AFTER SUNRISE AND WILL CONTINUE THROUGH EARLY AFTERNOON.
EXTENDED AVIATION OUTLOOK...GENERALLY VFR...ALTHOUGH CANT RULE
OUT A LITTLE MVFR/IFR VSBYS IN FOG WEDNESDAY MORNING.
&&
.MARINE...
CONTINUE TO FAVOR THE FASTER RUC SOLUTION WITH RESPECT TO FRONTAL
TIMING OVERNIGHT. THE LATEST TRENDS SUGGEST THE FRONT WILL REACH
THE CHARLESTON COUNTY COASTAL WATERS AROUND 2 AM AND WILL SURGE
STEADILY SOUTH...REACHING THE ALTAMAHA SOUND BY SUNRISE. EXPECT
WINDS OF 20-25 KT WITH TO PREVAIL ACROSS THE CHARLESTON COUNTY
COASTAL WATERS...TRENDING LOWER FARTHER SOUTH WITH THE HIGHEST
WINDS LIKELY HOLDING OFF UNTIL AFTER SUNRISE FROM EDISTO BEACH
SOUTH. SMALL CRAFT ADVISORIES ARE ALREADY IN EFFECT FOR ALL MARINE
ZONES AND LOOK WELL PLACED.
WINDS AND SEAS WILL REMAIN ELEVATED EARLY TUESDAY...AS THE
PRESSURE GRADIENT TIGHTENS IN RESPONSE TO BUILDING HIGH PRESSURE
BEHIND A DESCENDING COLD FRONT. WILL CONTINUE SMALL CRAFT
ADVISORIES FOR THE CHARLESTON HARBOR THROUGH NOON ON
TUESDAY...WHILE MAINTAINING ADVISORIES FOR THE NEARSHORE WATERS
THROUGH THE AFTERNOON HOURS. A BETTER FETCH OVER THE OUTER GEORGIA
WATERS WILL MAINTAIN ADVISORY-LEVEL SEAS THROUGH TUESDAY NIGHT.
SURFACE HIGH PRESSURE WILL STEADILY DRIFT SOUTHWARD AND INTO THE
ATLANTIC TUESDAY NIGHT THROUGH WEDNESDAY...ALLOWING WINDS AND
SEAS TO DIMINISH WITH THE RELAXING PRESSURE GRADIENT. THE GRADIENT
WILL THEN INCREASE AGAIN AS A BACKDOOR COLD FRONT DESCENDS TOWARD
THE REGION LATE WEDNESDAY INTO THURSDAY. EXPECT WINDS AND SEAS TO
RISE ACCORDINGLY...HOWEVER HEADLINES ARE NOT ANTICIPATED AT THIS
TIME.
&&
.EQUIPMENT...
THE KCLX RADAR WILL REMAIN OFFLINE THROUGH LATE TUESDAY AFTERNOON
FOR CLEANING AND PAINTING OF THE RADOME.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ330.
SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM EDT
THIS AFTERNOON FOR AMZ352.
SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ350.
SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 2 AM EDT
WEDNESDAY FOR AMZ374.
SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 5 PM EDT THIS
AFTERNOON FOR AMZ354.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...79
LONG TERM...ALSHEIMER
AVIATION...
MARINE...SPR/79
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1207 PM CDT TUE MAR 27 2012
.DISCUSSION...
ISSUED 1017 AM CDT TUE MAR 27 2012
BAND OF SHOWERS ACROSS EASTERN IOWA IS LARGELY ALOFT...WITH
SHOWERS/STORMS FURTHER SOUTHWEST INTO MISSOURI. MAIN COLD FRONT IS
STILL WELL OFF TO THE NORTHWEST...CROSSING ABOUT THE NORTHWEST
THIRD OF IOWA AT THE MOMENT. DEWPOINTS IN THE 50S HAVE MADE IT
INTO CENTRAL MISSOURI...AND WE SHOULD SEE THESE VALUES
OVERSPREADING THE CENTRAL AND WESTERN CWA THROUGH THE AFTERNOON.
MAIN QUESTION REMAINS WITH THE TIMING OF ANY SHOWER/STORM
DEVELOPMENT. LATEST RUC MODEL STARTING TO SHOW SOME DEVELOPMENT IN
FAR WESTERN ILLINOIS AROUND 4-5 PM AS SBCAPES INCREASE TO AROUND
2000 J/KG. HOWEVER...MOST OF THE SYNOPTIC AND HIGH-RESOLUTION
MODELS CONTINUE TO FAVOR THE EVENING HOURS AS BEING THE PRIME TIME
FOR THUNDERSTORMS WEST OF I-55...AND TOWARD MIDNIGHT FURTHER EAST.
HAVE LEFT THE RAIN CHANCES IN THE FAR WESTERN CWA LATE IN THE
AFTERNOON. WITH DECENT AMOUNTS OF SUNSHINE...HIGH TEMPERATURES
STILL LOOK GOOD...AND HAVE JUST DONE SOME REINTERPOLATION OF THE
HOURLY VALUES.
UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 1207 PM CDT TUE MAR 27 2012
NOT MUCH CHANGE NEEDED TO THE EXISTING TAFS. MAIN FOCUS THIS
AFTERNOON WILL BE SOUTHERLY WINDS GUSTING TO AROUND 25 KNOTS...
AHEAD OF A COLD FRONT WHICH IS CURRENTLY MOVING TOWARD THE
MISSISSIPPI VALLEY. SHOULD BEGIN TO SEE SCATTERED CONVECTION
DEVELOPING IN PARTS OF WESTERN ILLINOIS LATE THIS AFTERNOON. PRIME
PERIOD FOR THUNDER ACTIVITY AT THE TAF SITES WILL BE DURING THE
EVENING HOURS...AND HAVE MAINTAINED THE VCTS WITH ABOUT A 3-HOUR
TEMPO PERIOD OF THE MOST LIKELY TIME FOR SUSTAINED SHOWER/
THUNDERSTORM ACTIVITY. WILL MONITOR AS THE STORMS ACTUALLY
DEVELOP...TO TRY TO REFINE THIS TIME FRAME A LITTLE BETTER. ONCE
THE FRONT SWEEPS THROUGH...MAINLY CLEAR SKIES EXPECTED WEDNESDAY
MORNING.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 252 AM CDT TUE MAR 27 2012
SHORT TERM...TODAY THROUGH THURSDAY
AS HIGH PRESSURE CENTERED OVER THE EASTERN GREAT LAKES SHIFTS INTO
NEW ENGLAND...WINDS WILL VEER FROM E/SE TO S/SW ACROSS CENTRAL
ILLINOIS TODAY. THIS WILL USHER A MUCH WARMER AIRMASS BACK INTO
THE REGION...WITH AFTERNOON HIGH TEMPERATURES SOARING WELL INTO
THE 70S. DUE TO A TIGHTENING PRESSURE GRADIENT BETWEEN THE DEPARTING
HIGH AND AN APPROACHING COLD FRONT...WINDS WILL INCREASE INTO THE
15 TO 20 MPH RANGE...WITH GUSTS UP TO 30 MPH AT TIMES.
MEANWHILE...A VIGOROUS UPPER-LEVEL LOW WILL LIFT NORTHEASTWARD
ACROSS MINNESOTA...PULLING A TRAILING COLD FRONT TOWARD ILLINOIS
BY LATE IN THE DAY. AIRMASS AHEAD OF THE BOUNDARY WILL BECOME
MODERATELY UNSTABLE...WITH NAM INDICATING CAPE VALUES EXCEEDING
1500J/KG ACROSS THE ILLINOIS RIVER VALLEY BY 00Z. FURTHER
EAST...INSTABILITY WILL BE MUCH WEAKER AND ATMOSPHERE WILL REMAIN
CAPPED THROUGHOUT THE DAY. AS A RESULT...ANY CONVECTION THAT FIRES
WILL OCCUR IMMEDIATELY ALONG THE FRONT AND WILL THUS BE CONFINED
TO THE FAR W/NW KILX CWA AFTER 21Z. AS THE FRONT PUSHES FURTHER
EAST...SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THE REMAINDER
OF THE AREA THIS EVENING. DUE TO RATHER MEAGER CONVERGENCE ALONG
THE BOUNDARY AND THE OVERALL LACK OF GOOD UPPER SUPPORT...THINK
AREAL COVERAGE OF CONVECTION WILL REMAIN LOW. HAVE THEREFORE KEPT
POPS IN THE CHANCE CATEGORY FOR TONIGHT.
FRONT SAGS SOUTHWARD AND STALLS ACROSS THE OHIO RIVER VALLEY ON
WEDNESDAY...RESULTING IN A MOSTLY SUNNY AND DRY DAY. DESPITE
FROPA...TEMPERATURES WILL REMAIN ON THE WARM SIDE IN THE 70S DUE
TO A CONTINUED WESTERLY WIND. ONCE HIGH PRESSURE BUILDS INTO THE
GREAT LAKES AND WINDS SWITCH TO NORTHERLY BY WEDNESDAY NIGHT INTO
THURSDAY...A COOLER AIRMASS WILL SETTLE INTO THE REGION...RESULTING
IN HIGH TEMPS DROPPING BACK INTO THE 60S FOR THURSDAY.
LONG TERM...FRIDAY THROUGH MONDAY
ZONAL UPPER FLOW PATTERN WILL ESTABLISH ITSELF ACROSS THE CONUS
DURING THE EXTENDED...WITH A NUMBER OF FAST-MOVING WAVES EXPECTED
TO TRACK ACROSS THE COUNTRY DURING THAT TIME FRAME. THE FIRST WAVE
WILL APPROACH FROM THE WEST THURSDAY NIGHT...PULLING THE OHIO
RIVER VALLEY FRONT BACK NORTHWARD INTO THE AREA. WITH BOUNDARY IN
PLACE AND PLENTY OF MOISTURE TO WORK WITH...SHOWERS AND
THUNDERSTORMS WILL BE A GOOD BET THURSDAY NIGHT AND FRIDAY. A FEW
SHOWERS MAY LINGER INTO SATURDAY AS WELL...AS ADDITIONAL SHORT-WAVE
ENERGY RIPPLES THROUGH THE MIDWEST. AFTER THAT...MODEL SOLUTIONS
BEGIN TO DIVERGE EARLY NEXT WEEK...AS A STRONGER WAVE COMES
ONSHORE ALONG THE WEST COAST. BOTH THE ECMWF AND GFS INDICATE
RIDGING DOWNSTREAM OF THIS FEATURE FOR SUNDAY...WHICH WILL HELP
PUSH TEMPS BACK INTO THE 70S ACROSS CENTRAL ILLINOIS. THE MAIN
DISAGREEMENT OCCURS WITH THE APPROACH OF THE WAVE ON MONDAY...WITH
THE GFS SUGGESTING A MUCH MORE AMPLIFIED FEATURE. ECMWF SOLUTION
HAS BEEN VARYING WIDELY FROM RUN-TO-RUN...BUT IS BEGINNING TO SHOW
SIGNS OF COMING INTO BETTER AGREEMENT WITH THE GFS. AS A
RESULT...HAVE TRENDED TOWARD THE GFS FOR THE LAST PART OF THE
EXTENDED...WHICH MEANS ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS BY
MONDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1018 AM CDT TUE MAR 27 2012
.DISCUSSION...
ISSUED 1017 AM CDT TUE MAR 27 2012
BAND OF SHOWERS ACROSS EASTERN IOWA IS LARGELY ALOFT...WITH
SHOWERS/STORMS FURTHER SOUTHWEST INTO MISSOURI. MAIN COLD FRONT IS
STILL WELL OFF TO THE NORTHWEST...CROSSING ABOUT THE NORTHWEST
THIRD OF IOWA AT THE MOMENT. DEWPOINTS IN THE 50S HAVE MADE IT
INTO CENTRAL MISSOURI...AND WE SHOULD SEE THESE VALUES
OVERSPREADING THE CENTRAL AND WESTERN CWA THROUGH THE AFTERNOON.
MAIN QUESTION REMAINS WITH THE TIMING OF ANY SHOWER/STORM
DEVELOPMENT. LATEST RUC MODEL STARTING TO SHOW SOME DEVELOPMENT IN
FAR WESTERN ILLINOIS AROUND 4-5 PM AS SBCAPES INCREASE TO AROUND
2000 J/KG. HOWEVER...MOST OF THE SYNOPTIC AND HIGH-RESOLUTION
MODELS CONTINUE TO FAVOR THE EVENING HOURS AS BEING THE PRIME TIME
FOR THUNDERSTORMS WEST OF I-55...AND TOWARD MIDNIGHT FURTHER EAST.
HAVE LEFT THE RAIN CHANCES IN THE FAR WESTERN CWA LATE IN THE
AFTERNOON. WITH DECENT AMOUNTS OF SUNSHINE...HIGH TEMPERATURES
STILL LOOK GOOD...AND HAVE JUST DONE SOME REINTERPOLATION OF THE
HOURLY VALUES.
UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 641 AM CDT TUE MAR 27 2012
A COLD FRONT WILL BE APPROACHING THE AREA TODAY AND WILL BRING
THUNDERSTORMS TO ALL TAF SITES THIS EVENING AND INTO THE OVERNIGHT
HOURS. AHEAD OF THE FRONT...HIGH CIRRUS HAS OVERSPREAD ALL SITES.
EXPECTING SCATTER CU CLOUDS TO DEVELOP THIS MORNING AND CONTINUE
INTO THE AFTERNOON AHEAD OF THE FRONT...AS WELL AS THE CIRRUS TO
BEGIN TO THIN OUT. EXPECTING THUNDERSTORMS TO DEVELOP OUT WEST AND
THEN MOVE TOWARD THE SITES THIS EVENING...STARTING AT 02Z AT PIA.
WILL START WITH A VCTS AT ALL SITES 1HR BEFORE THE 3HR TEMPO GROUP
FOR BEST GUESS AS TO WHEN STORMS WILL BE AT THE SITES. AFTER
STORMS PASS...EXPECT SKIES TO EVENTUALLY CLEAR AT ALL SITES.
CURRENTLY NOT EXPECTING CIGS TO DROP INTO MVFR RANGES DURING THE
STORMS...BUT SHOULD SEE VIS DECREASE DURING THE RAIN.
PREDOMINATELY VFR CONDITIONS DURING 24HR FORECAST. WINDS WILL BE
SOUTHERLY AND INCREASE WITH GUST TO 23-29KTS. WINDS WILL BECOME
SOUTHWEST THIS AFTERNOON AHEAD OF THE FRONT. THEN EXPECT WIND
SHIFT/FROPA LATE TONIGHT DURING OR JUST AFTER STORMS PASS.
AUTEN
&&
.PREV DISCUSSION...
ISSUED 252 AM CDT TUE MAR 27 2012
SHORT TERM...TODAY THROUGH THURSDAY
AS HIGH PRESSURE CENTERED OVER THE EASTERN GREAT LAKES SHIFTS INTO
NEW ENGLAND...WINDS WILL VEER FROM E/SE TO S/SW ACROSS CENTRAL
ILLINOIS TODAY. THIS WILL USHER A MUCH WARMER AIRMASS BACK INTO
THE REGION...WITH AFTERNOON HIGH TEMPERATURES SOARING WELL INTO
THE 70S. DUE TO A TIGHTENING PRESSURE GRADIENT BETWEEN THE DEPARTING
HIGH AND AN APPROACHING COLD FRONT...WINDS WILL INCREASE INTO THE
15 TO 20 MPH RANGE...WITH GUSTS UP TO 30 MPH AT TIMES.
MEANWHILE...A VIGOROUS UPPER-LEVEL LOW WILL LIFT NORTHEASTWARD
ACROSS MINNESOTA...PULLING A TRAILING COLD FRONT TOWARD ILLINOIS
BY LATE IN THE DAY. AIRMASS AHEAD OF THE BOUNDARY WILL BECOME
MODERATELY UNSTABLE...WITH NAM INDICATING CAPE VALUES EXCEEDING
1500J/KG ACROSS THE ILLINOIS RIVER VALLEY BY 00Z. FURTHER
EAST...INSTABILITY WILL BE MUCH WEAKER AND ATMOSPHERE WILL REMAIN
CAPPED THROUGHOUT THE DAY. AS A RESULT...ANY CONVECTION THAT FIRES
WILL OCCUR IMMEDIATELY ALONG THE FRONT AND WILL THUS BE CONFINED
TO THE FAR W/NW KILX CWA AFTER 21Z. AS THE FRONT PUSHES FURTHER
EAST...SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THE REMAINDER
OF THE AREA THIS EVENING. DUE TO RATHER MEAGER CONVERGENCE ALONG
THE BOUNDARY AND THE OVERALL LACK OF GOOD UPPER SUPPORT...THINK
AREAL COVERAGE OF CONVECTION WILL REMAIN LOW. HAVE THEREFORE KEPT
POPS IN THE CHANCE CATEGORY FOR TONIGHT.
FRONT SAGS SOUTHWARD AND STALLS ACROSS THE OHIO RIVER VALLEY ON
WEDNESDAY...RESULTING IN A MOSTLY SUNNY AND DRY DAY. DESPITE
FROPA...TEMPERATURES WILL REMAIN ON THE WARM SIDE IN THE 70S DUE
TO A CONTINUED WESTERLY WIND. ONCE HIGH PRESSURE BUILDS INTO THE
GREAT LAKES AND WINDS SWITCH TO NORTHERLY BY WEDNESDAY NIGHT INTO
THURSDAY...A COOLER AIRMASS WILL SETTLE INTO THE REGION...RESULTING
IN HIGH TEMPS DROPPING BACK INTO THE 60S FOR THURSDAY.
LONG TERM...FRIDAY THROUGH MONDAY
ZONAL UPPER FLOW PATTERN WILL ESTABLISH ITSELF ACROSS THE CONUS
DURING THE EXTENDED...WITH A NUMBER OF FAST-MOVING WAVES EXPECTED
TO TRACK ACROSS THE COUNTRY DURING THAT TIME FRAME. THE FIRST WAVE
WILL APPROACH FROM THE WEST THURSDAY NIGHT...PULLING THE OHIO
RIVER VALLEY FRONT BACK NORTHWARD INTO THE AREA. WITH BOUNDARY IN
PLACE AND PLENTY OF MOISTURE TO WORK WITH...SHOWERS AND
THUNDERSTORMS WILL BE A GOOD BET THURSDAY NIGHT AND FRIDAY. A FEW
SHOWERS MAY LINGER INTO SATURDAY AS WELL...AS ADDITIONAL SHORT-WAVE
ENERGY RIPPLES THROUGH THE MIDWEST. AFTER THAT...MODEL SOLUTIONS
BEGIN TO DIVERGE EARLY NEXT WEEK...AS A STRONGER WAVE COMES
ONSHORE ALONG THE WEST COAST. BOTH THE ECMWF AND GFS INDICATE
RIDGING DOWNSTREAM OF THIS FEATURE FOR SUNDAY...WHICH WILL HELP
PUSH TEMPS BACK INTO THE 70S ACROSS CENTRAL ILLINOIS. THE MAIN
DISAGREEMENT OCCURS WITH THE APPROACH OF THE WAVE ON MONDAY...WITH
THE GFS SUGGESTING A MUCH MORE AMPLIFIED FEATURE. ECMWF SOLUTION
HAS BEEN VARYING WIDELY FROM RUN-TO-RUN...BUT IS BEGINNING TO SHOW
SIGNS OF COMING INTO BETTER AGREEMENT WITH THE GFS. AS A
RESULT...HAVE TRENDED TOWARD THE GFS FOR THE LAST PART OF THE
EXTENDED...WHICH MEANS ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS BY
MONDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
332 PM CDT TUE MAR 27 2012
.SHORT TERM /TONIGHT/...
SFC TROUGH AXIS ASSOCIATED WITH NORTHERN MINNESOTA LOW PRESSURE IS
EXTENDING SOUTH THROUGH CNTRL IA THIS AFTERNOON. AIRMASS BEHIND THE
TROUGH HAS DOWNSLOPE PROPERTIES INITIALLY REMAINING MILD YET MUCH
DRIER WITH DEWPOINTS IN THE 30S ADVECTING IN. DEWPOINTS REMAIN IN
THE MID TO UPPER 50S OVER THE SOUTHEAST IN ADVANCE OF THE SYSTEM.
UPPER PV ANOMALY OVER SRN SOUTH DAKOTA WILL TRACK EAST AND WILL BE
OVER FAR SOUTH CENTRAL MINNESOTA BY 00Z. SOME ASSOCIATED KINEMATIC
FORCING WILL OCCUR TO THE SOUTHEAST OF THE SYSTEM. CURRENTLY
INSTABILITY HAS BEEN INCREASING OVER THE SOUTHEAST THIRD OF THE
WARNING AREA. RUC AND NAM PROXIMITY SOUNDINGS SHOW A WEAK CAP
LOCATED NEAR 750 MB WHICH DOES NOT ERODE UNTIL AFTER 23Z WITH THE
ARRIVAL OF MID LEVEL COOLING AND KINEMATICS WITH THE MID LEVEL WAVE.
POSSIBLE A STORM OR TWO MAY FIRE OVER THE FAR SOUTHEAST BUT OVERALL
THE CURRENT INSTABILITY IS NOT EXPECTED TO BE REALIZED UNTIL IT
PUSHES SOUTHEAST OF THE STATE.
A FEW SITES NEAR WIND ADVISORY CRITERIA ATTM MOMENT THOUGH OVERALL
MOST ARE BELOW. HAVE TRIMMED PORTIONS OF THE ADVISORY BUT HAVE KEPT
THE NORTH TO KEEP COLLABORATED WITH SURROUNDING SITES. HAVE MOVED
END TIME UP TO 7 PM WITH WINDS DIMINISHING WITH THE LOSS OF DAY TIME
HEATING AND MIXING.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
TWO PRIMARY SYSTEMS TO CONTEND WITH IN THIS PERIOD. WEAK RIDGE
APPROACHING THE MO VALLEY PRECEDING SHORT WAVE EJECTING OUT OF
CURRENT EAST PACIFIC LONG WAVE THROUGH. THIS WAVE SHOULD REACH THE
HIGH PLAINS LATE TOMORROW WHICH...COMBINED WITH THE DEPARTING
RIDGE...WILL INCREASE WARM ADVECTION INTO THE MO VALLEY. THETA-E
ADVECTION ADVANCES INTO SWRN IA COINCIDENT WITH ELEVATED CAPE
GRADIENT. ALTHOUGH BEST ISENTROPIC LIFT WILL REMAIN NW INTO THE
DAKOTAS AND ERN MN...MODEL 300K SURFACES NEAR INVERSION TOP SUGGEST
THERE WILL BE SUFFICIENT LIFT AND SATURATION EARLY THU MORNING FOR
CONVECTION TO DEVELOP AND LINGER INTO THE MORNING.
ATTENTION THEN TURNS UPSTREAM WHERE BOTH NAM AND GFS DEPICT
1500-2500 J/KG MLCAPES BECOMING UNCAPPED JUST WEST OF MO RIVER
DURING PEAK HEATING. LOW LEVEL CONVERGENCE IS SOMEWHAT WEAK...BUT
THIS FAVORABLE THERMODYNAMIC ENVIRONMENT AIDED BY LARGE SCALE
FORCING WITH WAVE SHOULD BE SUFFICIENT FOR A MCS TO DEVELOP AND THEN
LIKELY WEAKEN INTO THE EVENING WITH LOSS OF HEATING. REGARDING
SEVERE POTENTIAL DURING EVENT...ELEVATED NATURE AND FAIRLY WEAK
UNIDIRECTIONAL FLOW IN EFFECTIVE INFLOW LAYER EARLY THU SHOULD
DIMINISH THIS SEVERE POTENTIAL. MOST LIKELY SEVERE CHANCES LOOK TO
BE DURING PEAK HEATING TAPPING BETTER 0-6KM SHEAR LATE AFTERNOON AND
EVENING WHEN AND IF CONVECTION BECOMES SURFACE BASED.
WEAK NORTHERN STREAM WAVE HAS RESULTED IN SLIGHT CHANCES FRI NIGHT
WITH NEXT LARGE SYSTEM IN THE OFFING EARLY NEXT WEEK. MODELS HAVE
COME INTO SOMEWHAT BETTER AGREEMENT WITH RESPECT TO TIMING
SUGGESTING FORCING INCREASING SUN NIGHT FOLLOWED BY FRONTAL PASSAGE
LATE SUNDAY AFTERNOON OR SUNDAY NIGHT. BEST SHEAR SEEMS TO REMAIN
TO OUR SOUTH AND INSTABILITY IS UNREMARKABLE AT THIS POINT SO DO NOT
SEE ELEVATED SEVERE THREAT WITH THIS SYSTEM AT THE MOMENT. DIRTY NW
FLOW WILL KEPT LOW CHANCES GOING IN ITS WAKE THROUGH TUE. TEMPS
WILL DROP SHARPLY BEHIND THIS...BUT ONLY DOWN TO ABOUT CLIMO. NO
FREEZING TEMPS OR FROST ANTICIPATED THROUGH DAY 7.
&&
.AVIATION...27/18Z
ISOLD THUNDERSTORM STILL POSSIBLE IN VICINITY OF KOTM THIS
AFTERNOON. OTHERWISE VFR CONDITIONS WITH GUSTY SOUTHWEST WINDS
EXPECTED. CLEAR OVERNIGHT WITH DIMINISHING WINDS WITH A SWITCH TO
NORTHWEST WINDS. BREEZY WITH VFR CONTINUING ON WEDNESDAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 7 PM
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN-
WEBSTER-HAMILTON-
&&
$$
SHORT TERM/AVIATION...DONAVON
LONG TERM...SMALL
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1216 PM CDT TUE MAR 27 2012
.AVIATION...
FLIGHT CONDITIONS WILL BE MAINLY VFR THROUGH THE FORECAST PERIOD.
STRONG SOUTHWEST WINDS THIS AFTERNOON WILL GUST TO AROUND 35KTS AT
TIMES. A COLD FRONT WILL PASS THROUGH THE REGION LATE THIS
AFTERNOON AND EARLY THIS EVENING. ISOLATED TO SCATTERED
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT AS IT
REACHES THE MISSISSIPPI RIVER LATE THIS AFTERNOON. THERE IS A LOW
PROBABILITY OF A STORM OCCURRING AT SPECIFIC TERMINAL SO...ONLY
VCTS MENTIONED IN THE TAF AT THIS TIME. THERE IS A LOW RISK THAT
SOME OF THE THUNDERSTORMS COULD BE SEVERE FOR PARTS OF EASTERN
IOWA...NORTHWEST ILLINOIS AND NORTHEAST MISSOURI. AFTER THE FROPA
THE WINDS WILL BECOME WEST TO NORTHWEST AND DIMINISH TO AROUND
10KTS.
&&
.PREV DISCUSSION... /ISSUED 1110 AM CDT TUE MAR 27 2012/
UPDATE...
NO UPDATES ARE PLANNED FOR THE GOING FORECAST FOR THIS AFTERNOON.
ELEVATED DYING SHRA/VIRGA CURRENTLY OVER THE CWFA SHOULD CONTINUE
TO WEAKEN AND DISSIPATE BY EARLY AFTERNOON. NAM/GFS RH H7/H5 RH
PROGS SHOW MID LEVELS DRYING OUT BY 18Z AND RECENT VIS SATELLITE
IMAGERY IS SHOWING CLOUDS DISSIPATING ON THE WEST EDGE OF THE
NARROW PCPN BAND SO EXPECT MORE SUN THIS AFTERNOON. THE SUN SHOULD
HELP THE LOW LEVEL MIX OUT TO AT LEAST 850MB WHICH SUPPORTS MID TO
UPPER 70 HIGHS AND WE COULD BE A LITTLE WARMER THAN THAN GIVEN THE
STRONG SW WINDS. THERE ARE NO PLANS FOR ANY WIND ADVISORIES THIS
AFTERNOON. SO FAR MOST SITES HAVE REMAINED BELOW ADVISORY
CRITERIA...WITH THE EXCEPTION OF KFEP...WHOSE 1555Z OB HAD A
SUSTAINED 31 MPH WIND. FEEL THAT ANY ADDITIONAL WINDS OF THIS OR
GREATER MAGNITUDE WILL BE SPOTTY AT BEST AND LOOKING TO THE WEST
IN CENTRAL IA IN THE WARM SECTOR...WINDS ARE REMAIN WELL BELOW
ADVISORY CRITERIA. BY THE TIME THE DEEPER MIXING SETS IN THIS
AFTERNOON H8 WINDS ARE PROGGED TO DECREASE TO 35-40KTS.
THE THUNDERSTORM THREAT STILL LOOKS REASONABLE LATE THIS AFTERNOON AND
EARLY THIS EVENING WITH ISOLATED TO SCATTERED TSRA EXPECTED TO
DEVELOP ALONG THE SURFACE COLD FRONT AS IT MOVES THROUGH THE SERN
CWFA. RECENT HRRR RUNS HOLD THE INITIATION OFF UNTIL AFTER 00Z WHILE
THE NAM FCSTS DEVELOP PRECIP IN THE SOUTHEAST BETWEEN 21Z AND 00Z.
THE SEVERE THREAT WILL HINGE ON THE AMOUNT OF AVAILABLE CAPE. AS
OF 15Z IT APPEARS THE NAM SURFACE DEWPOINTS OVER CENTRAL IA ARE
RUNNING A FEW DEGREES TO MOIST SUGGESTING THE MODEL CAPE IS ON THE
HIGH SIDE. WILL HAVE TO WATCH DEWPOINT TRENDS THROUGH THE
AFTERNOON TO SEE IF THE LOW 60 MODEL DEWPOINTS ARE REALIZED. THE
SEVERE THREAT STILL LOOKS TO BE MAINLY LARGE HAIL WITH THE MID
LEVEL DRYING EXPECTED TO OCCUR. ..DLF..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1110 AM CDT TUE MAR 27 2012
.UPDATE...
NO UPDATES ARE PLANNED FOR THE GOING FORECAST FOR THIS AFTERNOON.
ELEVATED DYING SHRA/VIRGA CURRENTLY OVER THE CWFA SHOULD CONTINUE
TO WEAKEN AND DISSIPATE BY EARLY AFTERNOON. NAM/GFS RH H7/H5 RH
PROGS SHOW MID LEVELS DRYING OUT BY 18Z AND RECENT VIS SATELLITE
IMAGERY IS SHOWING CLOUDS DISSIPATING ON THE WEST EDGE OF THE
NARROW PCPN BAND SO EXPECT MORE SUN THIS AFTERNOON. THE SUN SHOULD
HELP THE LOW LEVEL MIX OUT TO AT LEAST 850MB WHICH SUPPORTS MID TO
UPPER 70 HIGHS AND WE COULD BE A LITTLE WARMER THAN THAN GIVEN THE
STRONG SW WINDS. THERE ARE NO PLANS FOR ANY WIND ADVISORIES THIS
AFTERNOON. SO FAR MOST SITES HAVE REMAINED BELOW ADVISORY
CRITERIA...WITH THE EXCEPTION OF KFEP...WHOSE 1555Z OB HAD A
SUSTAINED 31 MPH WIND. FEEL THAT ANY ADDITIONAL WINDS OF THIS OR
GREATER MAGNITUDE WILL BE SPOTTY AT BEST AND LOOKING TO THE WEST
IN CENTRAL IA IN THE WARM SECTOR...WINDS ARE REMAIN WELL BELOW
ADVISORY CRITERIA. BY THE TIME THE DEEPER MIXING SETS IN THIS
AFTERNOON H8 WINDS ARE PROGGED TO DECREASE TO 35-40KTS.
THE THUNDERSTORM THREAT STILL LOOKS REASONABLE LATE THIS AFTERNOON AND
EARLY THIS EVENING WITH ISOLATED TO SCATTERED TSRA EXPECTED TO
DEVELOP ALONG THE SURFACE COLD FRONT AS IT MOVES THROUGH THE SERN
CWFA. RECENT HRRR RUNS HOLD THE INITIATION OFF UNTIL AFTER 00Z WHILE
THE NAM FCSTS DEVELOP PRECIP IN THE SOUTHEAST BETWEEN 21Z AND 00Z.
THE SEVERE THREAT WILL HINGE ON THE AMOUNT OF AVAILABLE CAPE. AS
OF 15Z IT APPEARS THE NAM SURFACE DEWPOINTS OVER CENTRAL IA ARE
RUNNING A FEW DEGREES TO MOIST SUGGESTING THE MODEL CAPE IS ON THE
HIGH SIDE. WILL HAVE TO WATCH DEWPOINT TRENDS THROUGH THE
AFTERNOON TO SEE IF THE LOW 60 MODEL DEWPOINTS ARE REALIZED. THE
SEVERE THREAT STILL LOOKS TO BE MAINLY LARGE HAIL WITH THE MID
LEVEL DRYING EXPECTED TO OCCUR. ..DLF..
&&
.AVIATION... /ISSUED 719 AM CDT TUE MAR 27 2012/
VFR CONDITIONS EXPECTED NEXT 24 HOURS AND BEYOND. SCATTERED TO BROKEN
CLOUDS WITH BASES WELL ABOVE 3K AGL UNTIL 00Z ALL TERMINALS. ISOLATED
STORMS POSSIBLE...MAINLY NEAR MLI-BRL TERMINALS BETWEEN 21-03Z. LOW
COVERAGE STORMS SUGGESTS SMALL CHANCE OF PRECIPITATION ATTM. SOUTH
WINDS TO INCREASE AND VEER TO SW AT 20 TO 30+ MPH WITH GUSTS AOA 35
MPH POSSIBLE UNTIL SUNSET OR 00Z. SKIES TO CLEAR WITH LIGHT WESTERLY
WINDS DEVELOPING BY 03Z ALL TERMINALS BECOMING NW OVERNIGHT INTO
WEDNESDAY MORNING. ..NICHOLS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1010 PM CDT WED MAR 28 2012
.MESOSCALE/CONVECTIVE UPDATE...
NEARLY STATIONARY SVR TSRA CELL ~30NM IN DIAMETER REMAINS CAMPED OVER
NE 1/3 OF GREENWOOD COUNTY WHERE TENNISBALL-SIZED HAIL & FLASH FLOOD-
PRODUCING TORRENTIAL RAINS WILL CONTINUE TO PLAGUE THE COUNTY THROUGH
MID-NIGHT & LIKELY BEYOND. STILL ANTICIPATE SOME ESE PROPAGATION AS
LOW-LVL JET CONTINUES TO STRENGTHEN FROM CNTRL OK N/NE ACROSS SE KS.
SHARPENED POPS/WX/QPF GRIDS THROUGH MID-NIGHT TO FURTHER REFINE MOST
RECENT CONVECTIVE TRENDS...NO DOUBT FOCUSING GREENWOOD & WOODSON
COUNTIES. FURTHER REFINEMENT IS LIKELY FROM MID- NGT THROUGH 7 AM CDT.
STAY TUNED.
&&
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
IMMEDIATE FOCUS (NO PUN INTENDED) IS ON WHAT HAS BECOME AN ISOLD SVR
TSRA (CAPABLE OF VERY LARGE HAIL & ++RA) OCCURRING OVER NRN GREENWOOD
COUNTY. FOR NOW CELL REMAINS NEARLY STATIONARY BUT CONTINUED CONCERN
THAT CELL COULD SLOWLY PROPAGATE E/SE TOWARD KCNU EARLY THU MORNING.
FOR NOW PLAN IS TO KEEP "VCTS" ASSIGNED TO KCNU & BE QUICK TO UPDATE
THE MOMENT DOPPLER TRENDS INDICATE E/SE EXPANSION TO BE FURTHER THAN
PICTURED AT THIS TIME.
SECOND FOCUS IS ON POTENTIAL FOR 1,000-1,500FT CIGS & 4-5SM VSBYS LATE
TONIGHT/EARLY THU MORNING AS WEAK LWR-DECK TROF AXIS REMAINS SITUATED
OVER WRN KS. RADIATIONAL COOLING COUPLED WITH CONTINUED NWD SURGING
GULF MOISTURE SHOULD KEEP ALL 5 TERMINALS IN MVFR STATUS 10Z-14Z WITH
ALL 5 TERMINALS RETURNING TO VFR STATUS BY 15Z.
&&
.PREV DISCUSSION... /ISSUED 834 PM CDT WED MAR 28 2012/
MESOSCALE/CONVECTIVE UPDATE...
CLUSTER OF SVR TSRA CONTINUES TO BUILD/PROPAGATE SLOWLY E/SE FROM
GREENWOOD TOWARD WOODSON & ALLEN COUNTIES ALONG FAIRLY WELL-DEFINED
SFC-850MB MOISTURE AXIS ORIENTED ALONG WEAK ELEVATED FRONTAL BOUNDARY.
AS SUCH SVR #114 HAS BEEN ISSUED FOR ALL 3 COUNTIES TIL MID-NIGHT. THE
VERY SLOW MOVEMENT OF THE CELLS NO DOUBT PRODUCES AN INCREASED THREAT
FOR LOCALIZED FLOODING FROM NRN GREENWOOD TO NRN WOODSON COUNTIES. ALL
WX/POPS/QPF HAVE BEEN FINE-TUNED.
PREV DISCUSSION... /ISSUED 308 PM CDT WED MAR 28 2012/
DISCUSSION...
THE PRIMARY FOCUS CONTINUES TO BE PERIODIC THUNDERSTORM CHANCES
THROUGH THE WEEK.
A BROAD MID/UPPER RIDGE WAS COVERING MUCH OF THE CENTRAL AND SOUTHERN
CONUS WHILE A SUBTLE SHORTWAVE TROUGH WAS MOVING OVER SOUTHERN
KANSAS EARLY THIS AFTERNOON. THE WARM FRONT HAS BECOME DIFFUSE
MOST EVIDENT IN THE TD SPREADS LOCATED NEAR I-70 EARLY THIS
AFTERNOON. STRONG CINH IS EXPECTED TO PRECLUDE MORE WIDESPREAD
THUNDERSTORM DEVELOPMENT FURTHER SOUTH ALONG THE DRY LINE THIS
AFTERNOON/EARLY EVENING BUT MAINTAINED HIGHER POPS ALONG AND NORTH
OF THE DIFFUSE WARM FRONT BORDERING TOP CWA THIS EVENING/TONIGHT AS
STRONGER 305K ISENTROPIC UPGLIDE BECOMES JUXTAPOSED ALONG THE NOSE
OF THE LLJ. THE LATEST HRRR KEEPS THE MAIN AREA OF CONVECTION WELL
NORTH OF THE FORECAST AREA...BUT MAINTAINED MID POPS ACROSS MUCH OF
CENTRAL KANSAS WHERE THE ACTIVITY MAY DEVELOP BEFORE SHIFTING
EASTWARD OUT OF THE AREA AFTER 09-11Z OR EARLIER. ANY STORMS THAT
DEVELOP THROUGH TONIGHT MAY BECOME SEVERE WITH LARGE HAIL AND
DAMAGING WINDS.
THU-SUN...ABOVE NORMAL TEMPERATURES ARE ANTICIPATED THROUGH THE
PERIOD WITH ANOTHER OPPORTUNITY FOR DEEP MOIST CONVECTION LATE
THURSDAY AFTERNOON/THURSDAY NIGHT AS A SHORT WAVE TROUGH TRANSLATES
RAPIDLY EAST OVER THE AREA. THE NAM IS MUCH MORE PROGRESSIVE WITH
THE SFC TROUGH AXIS AND TRENDED POPS FURTHER EAST COMPARED TO THE
PREVIOUS FORECAST KEEPING THE HIGHEST PROBABILITIES ALONG/EAST OF
THE KANSAS TURNPIKE. SHORTWAVE RIDGING IS PROGGED TO RETURN TO THE
CENTRAL PLAINS FRI-SAT LEADING TO FAIR WEATHER AND CONTINUED ABOVE
NORMAL TEMPERATURES. TRENDED HIGHS ON FRI-SUN SLIGHTLY HIGHER WITH
READINGS CLIMBING INTO THE LOW-MID 80S SAT-SUN.
MON-WED...ANOTHER MORE ROBUST MID/UPPER TROUGH WILL RACE EASTWARD
ACROSS THE CENTRAL PLAINS LATE SUNDAY INTO MONDAY BRINGING A RETURN
TO SEASONABLE TEMPERATURES IN THE 60S INTO THE BEGINNING OF NEXT
WEEK. PRECIPITATION CHANCES CONTINUE TO LOOK SLIM GIVIN THE
PROGRESSIVE NATURE OF THE MID/UPPER TROUGH WITH A RETURN TO ABOVE
NORMAL TEMPERATURES TOWARD THE MIDDLE OF THE WEEK.
FIRE WEATHER...
A TROUGH OF LOW PRESSURE WILL DEVELOP ACROSS CENTRAL KANSAS ON
THURSDAY WITH WIDELY SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE
ALONG AND EAST OF THIS TROUGH. FURTHER WEST...LOW RELATIVE
HUMIDITIES MAY COMBINE WITH GUSTY SOUTHWEST WINDS CREATING NEAR
CRITICAL FIRE WEATHER CONDITIONS AT TIMES DURING THE AFTERNOON HOURS
ON THURSDAY. GUSTY SOUTHWEST WINDS WILL RETURN LATE IN THE WEEKEND
AHEAD OF A STRONG STORM SYSTEM MOVING OVER THE ROCKIES. GUSTY NORTHWEST
WINDS WILL FOLLOW THE PASSAGE OF A COLD FRONT LATE SUNDAY
NIGHT/EARLY MONDAY WITH A RETURN TO MORE SEASONABLE TEMPERATURES FOR
THE BEGINNING OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 61 85 56 79 / 20 30 20 10
HUTCHINSON 60 83 54 78 / 20 20 20 10
NEWTON 60 82 57 78 / 30 20 20 10
ELDORADO 61 84 59 79 / 30 30 30 10
WINFIELD-KWLD 62 85 58 81 / 20 20 40 10
RUSSELL 55 80 49 79 / 20 20 20 10
GREAT BEND 58 81 51 78 / 10 20 20 10
SALINA 59 83 54 80 / 40 20 20 10
MCPHERSON 61 82 54 79 / 20 20 20 10
COFFEYVILLE 63 85 59 81 / 30 20 60 20
CHANUTE 61 84 59 81 / 70 20 60 10
IOLA 61 83 59 81 / 70 20 60 10
PARSONS-KPPF 62 85 59 80 / 40 20 60 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
834 PM CDT WED MAR 28 2012
.MESOSCALE/CONVECTIVE UPDATE...
CLUSTER OF SVR TSRA CONTINUES TO BUILD/PROPAGATE SLOWLY E/SE FROM
GREENWOOD TOWARD WOODSON & ALLEN COUNTIES ALONG FAIRLY WELL-DEFINED
SFC-850MB MOISTURE AXIS ORIENTED ALONG WEAK ELEVATED FRONTAL BOUNDARY.
AS SUCH SVR #114 HAS BEEN ISSUED FOR ALL 3 COUNTIES TIL MID-NIGHT. THE
VERY SLOW MOVEMENT OF THE CELLS NO DOUBT PRODUCES AN INCREASED THREAT
FOR LOCALIZED FLOODING FROM NRN GREENWOOD TO NRN WOODSON COUNTIES. ALL
WX/POPS/QPF HAVE BEEN FINE-TUNED.
&&
.PREV DISCUSSION... /ISSUED 717 PM CDT WED MAR 28 2012/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
IMMEDIATE FOCUS (NO PUN INTENDED) IS ON FAIRLY LARGE CLUSTER OF SVR
TSRA (CAPABLE OF GOLFBALL-SIZED HAIL) OCCURRING OVER NE & EC KS. THE
SRN-MOST CELL WAS SITUATED OVER NRN GREENWOOD COUNTY. MOVG NE25KTS
THIS CONVECTION WILL REMAIN N OF KCNU & HAVE THEREFORE ASSIGNED "VCTS"
TO THIS TAF FOR THIS EVENING.
SECOND FOCUS IS ON POTENTIAL FOR 1,000-1,500FT CIGS & 4-5SM VSBYS LATE
TONIGHT/EARLY THU MORNING AS WEAK LWR-DECK TROF AXIS REMAINS SITUATED
OVER WRN KS. RADIATIONAL COOLING COUPLED WITH CONTINUED NWD SURGING
GULF MOISTURE SHOULD KEEP ALL 5 TERMINALS IN MVFR STATUS 10Z-14Z WITH
ALL 5 TERMINALS RETURNING TO VFR STATUS BY 15Z.
PREV DISCUSSION... /ISSUED 308 PM CDT WED MAR 28 2012/
DISCUSSION...
THE PRIMARY FOCUS CONTINUES TO BE PERIODIC THUNDERSTORM CHANCES
THROUGH THE WEEK.
A BROAD MID/UPPER RIDGE WAS COVERING MUCH OF THE CENTRAL AND SOUTHERN
CONUS WHILE A SUBTLE SHORTWAVE TROUGH WAS MOVING OVER SOUTHERN
KANSAS EARLY THIS AFTERNOON. THE WARM FRONT HAS BECOME DIFFUSE
MOST EVIDENT IN THE TD SPREADS LOCATED NEAR I-70 EARLY THIS
AFTERNOON. STRONG CINH IS EXPECTED TO PRECLUDE MORE WIDESPREAD
THUNDERSTORM DEVELOPMENT FURTHER SOUTH ALONG THE DRY LINE THIS
AFTERNOON/EARLY EVENING BUT MAINTAINED HIGHER POPS ALONG AND NORTH
OF THE DIFFUSE WARM FRONT BORDERING TOP CWA THIS EVENING/TONIGHT AS
STRONGER 305K ISENTROPIC UPGLIDE BECOMES JUXTAPOSED ALONG THE NOSE
OF THE LLJ. THE LATEST HRRR KEEPS THE MAIN AREA OF CONVECTION WELL
NORTH OF THE FORECAST AREA...BUT MAINTAINED MID POPS ACROSS MUCH OF
CENTRAL KANSAS WHERE THE ACTIVITY MAY DEVELOP BEFORE SHIFTING
EASTWARD OUT OF THE AREA AFTER 09-11Z OR EARLIER. ANY STORMS THAT
DEVELOP THROUGH TONIGHT MAY BECOME SEVERE WITH LARGE HAIL AND
DAMAGING WINDS.
THU-SUN...ABOVE NORMAL TEMPERATURES ARE ANTICIPATED THROUGH THE
PERIOD WITH ANOTHER OPPORTUNITY FOR DEEP MOIST CONVECTION LATE
THURSDAY AFTERNOON/THURSDAY NIGHT AS A SHORT WAVE TROUGH TRANSLATES
RAPIDLY EAST OVER THE AREA. THE NAM IS MUCH MORE PROGRESSIVE WITH
THE SFC TROUGH AXIS AND TRENDED POPS FURTHER EAST COMPARED TO THE
PREVIOUS FORECAST KEEPING THE HIGHEST PROBABILITIES ALONG/EAST OF
THE KANSAS TURNPIKE. SHORTWAVE RIDGING IS PROGGED TO RETURN TO THE
CENTRAL PLAINS FRI-SAT LEADING TO FAIR WEATHER AND CONTINUED ABOVE
NORMAL TEMPERATURES. TRENDED HIGHS ON FRI-SUN SLIGHTLY HIGHER WITH
READINGS CLIMBING INTO THE LOW-MID 80S SAT-SUN.
MON-WED...ANOTHER MORE ROBUST MID/UPPER TROUGH WILL RACE EASTWARD
ACROSS THE CENTRAL PLAINS LATE SUNDAY INTO MONDAY BRINGING A RETURN
TO SEASONABLE TEMPERATURES IN THE 60S INTO THE BEGINNING OF NEXT
WEEK. PRECIPITATION CHANCES CONTINUE TO LOOK SLIM GIVIN THE
PROGRESSIVE NATURE OF THE MID/UPPER TROUGH WITH A RETURN TO ABOVE
NORMAL TEMPERATURES TOWARD THE MIDDLE OF THE WEEK.
FIRE WEATHER...
A TROUGH OF LOW PRESSURE WILL DEVELOP ACROSS CENTRAL KANSAS ON
THURSDAY WITH WIDELY SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE
ALONG AND EAST OF THIS TROUGH. FURTHER WEST...LOW RELATIVE
HUMIDITIES MAY COMBINE WITH GUSTY SOUTHWEST WINDS CREATING NEAR
CRITICAL FIRE WEATHER CONDITIONS AT TIMES DURING THE AFTERNOON HOURS
ON THURSDAY. GUSTY SOUTHWEST WINDS WILL RETURN LATE IN THE WEEKEND
AHEAD OF A STRONG STORM SYSTEM MOVING OVER THE ROCKIES. GUSTY NORTHWEST
WINDS WILL FOLLOW THE PASSAGE OF A COLD FRONT LATE SUNDAY
NIGHT/EARLY MONDAY WITH A RETURN TO MORE SEASONABLE TEMPERATURES FOR
THE BEGINNING OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 61 85 56 79 / 30 30 20 10
HUTCHINSON 60 83 54 78 / 30 20 20 10
NEWTON 60 82 57 78 / 30 20 20 10
ELDORADO 61 84 59 79 / 30 30 30 10
WINFIELD-KWLD 62 85 58 81 / 20 20 40 10
RUSSELL 55 80 49 79 / 20 20 20 10
GREAT BEND 58 81 51 78 / 20 20 20 10
SALINA 59 83 54 80 / 40 20 20 10
MCPHERSON 61 82 54 79 / 30 20 20 10
COFFEYVILLE 63 85 59 81 / 30 20 60 20
CHANUTE 61 84 59 81 / 60 20 60 10
IOLA 61 83 59 81 / 70 20 60 10
PARSONS-KPPF 62 85 59 80 / 40 20 60 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
717 PM CDT WED MAR 28 2012
.AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
IMMEDIATE FOCUS (NO PUN INTENDED) IS ON FAIRLY LARGE CLUSTER OF SVR
TSRA (CAPABLE OF GOLFBALL-SIZED HAIL) OCCURRING OVER NE & EC KS. THE
SRN-MOST CELL WAS SITUATED OVER NRN GREENWOOD COUNTY. MOVG NE25KTS
THIS CONVECTION WILL REMAIN N OF KCNU & HAVE THEREFORE ASSIGNED "VCTS"
TO THIS TAF FOR THIS EVENING.
SECOND FOCUS IS ON POTENTIAL FOR 1,000-1,500FT CIGS & 4-5SM VSBYS LATE
TONIGHT/EARLY THU MORNING AS WEAK LWR-DECK TROF AXIS REMAINS SITUATED
OVER WRN KS. RADIATIONAL COOLING COUPLED WITH CONTINUED NWD SURGING
GULF MOISTURE SHOULD KEEP ALL 5 TERMINALS IN MVFR STATUS 10Z-14Z WITH
ALL 5 TERMINALS RETURNING TO VFR STATUS BY 15Z.
&&
.PREV DISCUSSION... /ISSUED 308 PM CDT WED MAR 28 2012/
DISCUSSION...
THE PRIMARY FOCUS CONTINUES TO BE PERIODIC THUNDERSTORM CHANCES
THROUGH THE WEEK.
A BROAD MID/UPPER RIDGE WAS COVERING MUCH OF THE CENTRAL AND SOUTHERN
CONUS WHILE A SUBTLE SHORTWAVE TROUGH WAS MOVING OVER SOUTHERN
KANSAS EARLY THIS AFTERNOON. THE WARM FRONT HAS BECOME DIFFUSE
MOST EVIDENT IN THE TD SPREADS LOCATED NEAR I-70 EARLY THIS
AFTERNOON. STRONG CINH IS EXPECTED TO PRECLUDE MORE WIDESPREAD
THUNDERSTORM DEVELOPMENT FURTHER SOUTH ALONG THE DRY LINE THIS
AFTERNOON/EARLY EVENING BUT MAINTAINED HIGHER POPS ALONG AND NORTH
OF THE DIFFUSE WARM FRONT BORDERING TOP CWA THIS EVENING/TONIGHT AS
STRONGER 305K ISENTROPIC UPGLIDE BECOMES JUXTAPOSED ALONG THE NOSE
OF THE LLJ. THE LATEST HRRR KEEPS THE MAIN AREA OF CONVECTION WELL
NORTH OF THE FORECAST AREA...BUT MAINTAINED MID POPS ACROSS MUCH OF
CENTRAL KANSAS WHERE THE ACTIVITY MAY DEVELOP BEFORE SHIFTING
EASTWARD OUT OF THE AREA AFTER 09-11Z OR EARLIER. ANY STORMS THAT
DEVELOP THROUGH TONIGHT MAY BECOME SEVERE WITH LARGE HAIL AND
DAMAGING WINDS.
THU-SUN...ABOVE NORMAL TEMPERATURES ARE ANTICIPATED THROUGH THE
PERIOD WITH ANOTHER OPPORTUNITY FOR DEEP MOIST CONVECTION LATE
THURSDAY AFTERNOON/THURSDAY NIGHT AS A SHORT WAVE TROUGH TRANSLATES
RAPIDLY EAST OVER THE AREA. THE NAM IS MUCH MORE PROGRESSIVE WITH
THE SFC TROUGH AXIS AND TRENDED POPS FURTHER EAST COMPARED TO THE
PREVIOUS FORECAST KEEPING THE HIGHEST PROBABILITIES ALONG/EAST OF
THE KANSAS TURNPIKE. SHORTWAVE RIDGING IS PROGGED TO RETURN TO THE
CENTRAL PLAINS FRI-SAT LEADING TO FAIR WEATHER AND CONTINUED ABOVE
NORMAL TEMPERATURES. TRENDED HIGHS ON FRI-SUN SLIGHTLY HIGHER WITH
READINGS CLIMBING INTO THE LOW-MID 80S SAT-SUN.
MON-WED...ANOTHER MORE ROBUST MID/UPPER TROUGH WILL RACE EASTWARD
ACROSS THE CENTRAL PLAINS LATE SUNDAY INTO MONDAY BRINGING A RETURN
TO SEASONABLE TEMPERATURES IN THE 60S INTO THE BEGINNING OF NEXT
WEEK. PRECIPITATION CHANCES CONTINUE TO LOOK SLIM GIVIN THE
PROGRESSIVE NATURE OF THE MID/UPPER TROUGH WITH A RETURN TO ABOVE
NORMAL TEMPERATURES TOWARD THE MIDDLE OF THE WEEK.
FIRE WEATHER...
A TROUGH OF LOW PRESSURE WILL DEVELOP ACROSS CENTRAL KANSAS ON
THURSDAY WITH WIDELY SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE
ALONG AND EAST OF THIS TROUGH. FURTHER WEST...LOW RELATIVE
HUMIDITIES MAY COMBINE WITH GUSTY SOUTHWEST WINDS CREATING NEAR
CRITICAL FIRE WEATHER CONDITIONS AT TIMES DURING THE AFTERNOON HOURS
ON THURSDAY. GUSTY SOUTHWEST WINDS WILL RETURN LATE IN THE WEEKEND
AHEAD OF A STRONG STORM SYSTEM MOVING OVER THE ROCKIES. GUSTY NORTHWEST
WINDS WILL FOLLOW THE PASSAGE OF A COLD FRONT LATE SUNDAY
NIGHT/EARLY MONDAY WITH A RETURN TO MORE SEASONABLE TEMPERATURES FOR
THE BEGINNING OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 61 85 56 79 / 30 30 20 10
HUTCHINSON 60 83 54 78 / 30 20 20 10
NEWTON 60 82 57 78 / 30 20 20 10
ELDORADO 61 84 59 79 / 30 30 30 10
WINFIELD-KWLD 62 85 58 81 / 20 20 40 10
RUSSELL 55 80 49 79 / 20 20 20 10
GREAT BEND 58 81 51 78 / 20 20 20 10
SALINA 59 83 54 80 / 30 20 20 10
MCPHERSON 61 82 54 79 / 30 20 20 10
COFFEYVILLE 63 85 59 81 / 30 20 60 20
CHANUTE 61 84 59 81 / 50 20 60 10
IOLA 61 83 59 81 / 50 20 60 10
PARSONS-KPPF 62 85 59 80 / 30 20 60 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
636 PM CDT WED MAR 28 2012
...MESO AND AVIATION UPDATE...
.DISCUSSION...
LATEST SFC ANALYSIS SUGGESTS THE WARM FRONT HAS BECOME A LITTLE MORE
DIFFUSE OVER THE LAST HOUR. THERE IS STILL PLENTY OF INSTABILITY FOR
STORM DEVELOPMENT BUT 0 TO 1 KM SHEAR REMAINS MARGINAL. HOWEVER AS
SEEN WITH RECENT STORMS...DEEP LAYER SHEAR IS GOOD ENOUGH FOR
SUPERCELL DEVELOPMENT. THE CONCERN IS WHEN THE LOW LEVEL JET
DEVELOPS THIS EVENING. LOW LEVEL SHEAR COULD INCREASE AND ANY STORM
ROOTED IN THE BOUNDARY LAYER MAY BE ABLE TO FEED OFF OF THE
INCREASED SHEAR. EXPECT SEVERE THUNDERSTORM HAZARDS OF HAIL AND
POTENTIAL AN ISOLATED TORNADO TO PERSIST WELL INTO THE EVENING.
WOLTERS
&&
.AVIATION...
TIMING OF TS IN THE TERMINAL IS STILL NOT OBVIOUS WITH THE FRONT
BECOMING LESS DEFINED. THEREFORE WILL CONTINUE WITH VCTS UNTIL TS
BECOMES MORE OBVIOUS. OBJECTIVE GUIDANCE SUGGESTS SOME MVFR
CONDITIONS DEVELOPING AFTER MIDNIGHT IS SKIES CLEAR OUT. CONFIDENCE
IN THIS IS UNCERTAIN SINCE FOCUS IS MORE ON CONVECTION.
WOLTERS
&&
.PREV DISCUSSION... /324 PM CDT WED MAR 28 2012/
ZONAL MID AND UPPER LEVEL FLOW WAS NOTED ACROSS THE CENTRAL AND
SOUTHERN PLAINS. A MINOR H5 TROUGH WAS MOVING INTO NORTHWEST KS THIS
AFTERNOON.
AT 19Z...A WEAK SFC LOW WAS LOCATED NORTHEAST OF DDC. A WARM FRONT
FRONT EXTEND EAST-NORTHEAST FROM THE SFC LOW ACROSS CENTRAL AND
NORTHEAST KS. THE SFC WARM FRONT WAS LOCATED ABOUT 20 MILES NORTH OF
I-70. SOUTH OF THE SFC WARM FRONT DEWPOINTS WERE IN THE LOWER 60S
AND SBCAPE WAS IN THE 2,000 TO 2,500 J/KG RANGE. AS TEMPERATURES
WARM LATER THIS AFTERNOON...SBCAPE WILL INCREASE TO 3,000 TO 3,500
J/KG ACROSS THE SOUTHERN HALF OF THE CWA.
ELEVATED THUNDERSTORMS HAVE DEVELOPED NORTH OF THE WARM FRONT ACROSS
SOUTH CENTRAL NE THIS AFTERNOON. THIS AREA OF STORMS WILL EXPAND
EAST AND SOUTHEAST ACROSS NORTH CENTRAL KS LATE THIS AFTERNOON. ONCE
THE STORMS REACH THE WARM SECTOR THE NEW UPDRAFTS WILL BECOME
ROOTED IN THE BOUNDARY LAYER. 0-6KM BULK SHEAR WILL BE ABOUT 40 TO
50 KTS LATE THIS AFTERNOON AND THROUGH THE EVENING HOURS ACROSS THE
CWA. GIVEN THE MODERATE VERTICAL WIND SHEAR AND
INSTABILITY...THUNDERSTORM UPDRAFTS THAT DEVELOP ALONG AND SOUTH OF
THE WARM FRONT WILL ROTATE. THE SUPERCELL THUNDERSTORMS WILL BE
CAPABLE OF PRODUCING LARGE HAIL...MAY BE UP TO BASEBALL SIZE...AND
DAMAGING OUTFLOW WINDS. THE LOW-LEVEL VERTICAL WIND SHEAR IS
WEAKER...THUS TORNADO PROBABILITIES WILL BE LOW. HOWEVER...LATE THIS
AFTERNOON AND EARLY THIS EVENING ACROSS NORTH CENTRAL KS BRIEF
TORNADOES MAY BE POSSIBLE WITH ANY ISOLATED SUPERCELLS. ALSO, IF
SUPERCELLS ARE ISOLATED ACROSS EAST CENTRAL KS THE RUC AND NAM
MODELS SHOW THE BACKED LOW-LEVEL JET INCREASING TO 30 TO 40
KTS...WHICH WOULD PROVIDE A BETTER ENVIRONMENT FOR ANY ISOLATED
SUPERCELL TO PRODUCE TORNADOES FROM 1Z TO 4Z.
AS THE EVENING PROGRESSES THE ISOLATED TO SCATTERED SUPERCELL
THUNDERSTORMS MAY CONGEAL INTO SEGMENTED SQUALL LINES OR QLCS`S.
INDIVIDUAL UPDRAFTS MAY BE STRONG ENOUGH FOR LARGE HAIL...AND THE
THREAT FOR DAMAGING WINDS MAY INCREASE WITH THE DEVELOPMENT OF A
QLCS THROUGH THE EVENING HOURS ACROSS THE REMAINDER OF THE CWA. THE
BEST CHANCES FOR THUNDERSTORMS THIS EVENING WILL BE ALONG AND NORTH
OF THE WARM FRONT...WHICH WILL BE ABOUT I-70 NORTH TO THE NE BORDER.
THOUGH STORMS WILL DEVELOP SOUTHEAST ACROSS THE REMAINDER OF THE CWA
DURING THE LATE EVENING HOURS. THE THREAT FOR SEVERE WEATHER SHOULD
DECREASE AFTER MIDNIGHT AS THE INSTABILITY DECREASES. IF A QLCS
DEVELOPS THAN HEAVY RAINFALL MAY BE POSSIBLE LATER THIS EVENING
ACROSS NORTHEAST AND EAST CENTRAL KS.
THURSDAY...A MORE AMPLIFIED H5 TROUGH WILL MOVE ACROSS THE CENTRAL
PLAINS DURING THE AFTERNOON HOURS. A SFC COLD FRONT WILL PUSH
SOUTHEAST ACROSS NORTH CENTRAL KS BY AFTERNOON. SCATTERED
THUNDERSTORMS WILL ONCE AGAIN DEVELOP ALONG AND AHEAD OF THE COLD
FRONT. THE 12Z NAM MODEL FORECAST SBCAPE TO INCREASE TO AROUND 3,000
J/KG ACROSS THE WARM SECTOR. THUNDERSTORMS THAT DEVELOP MAY BECOME
SEVERE. THE 0-6KM BULK SHEAR WILL BE A BIT STRONGER AHEAD OF THE H5
TROUGH BUT THE LOW-LEVEL WINDS AHEAD OF THE COLD FRONT WILL VEER
THROUGH THE AFTERNOON. THEREFORE...THE PRIMARY HAZARD WITH ANY
SUPERCELL THUNDERSTORM OR SQUALL LINE WILL BE LARGE HAIL AND
DAMAGING OUTFLOW WINDS. SKIES WILL CLEAR BY MID MORNING INTO THE
EARLY AFTERNOON HOURS. THUS THE INSOLATION AND SOUTHERLY WINDS AHEAD
OF THE COLD FRONT WILL HELP HIGH TEMPERATURES TO REACH THE UPPER 70S
TO LOWER 80S ACROSS THE CWA. IF THE SFC FRONT MOVES A BIT FASTER
THEN NORTH CENTRAL KS MAY BE A FEW DEGREES COOLER.
GARGAN
CONVECTION TIED TO COLD FRONT EXPECTED TO MOVE OUT OF EASTERN
KANSAS THURSDAY NIGHT...WITH CLEARING SKIES FOR FRIDAY. MUCH ABOVE
NORMAL TEMPERATURES SHOULD CONTINUE THROUGH THE WEEKEND.
NEXT CHANCE FOR PRECIPITATION WILL OCCUR WITH A STRONGER COLD
FRONT COMING THROUGH SUNDAY NIGHT AS DEEP UPPER TROUGH MOVES
ACROSS THE PLAINS. SOME WRAPAROUND SHOWERS LOOK LIKE THEY WILL
LINGER INTO MONDAY ASSOCIATED WITH THE COLD AIR ALOFT BEHIND THE
FRONT.
TEMPERATURES TUESDAY MORNING COULD FALL INTO THE 30S BEHIND THAT
SYSTEM...BUT WITH EXPECTED MIXING CONTINUING OVERNIGHT...WOULD
NOT THINK THAT FROST WOULD BE LIKELY.
DRY CONDITIONS AND A GRADUAL WARMUP IS THEN IN STORE FOR THE
MIDDLE OF THE WEEK.
60
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
109 AM MDT TUE MAR 27 2012
.UPDATE...
ISSUED AT 914 PM MDT MON MAR 26 2012
UPDATE HAS BEEN COMPLETED. WINDS HAVE DECREASED ACROSS MOST OF THE
AREA. WITH A FEW SPOTS EXPECTED TO GUST CLOSE TO 40 TO 45 MPH FOR
A BRIEF TIME...DO NOT EXPECT WIND ADVISORY CRITERIA TO BE REACHED.
SO ADVISORY WAS ALLOWED TO EXPIRE. WINDS HAVE DECREASED AND
RELATIVE HUMIDITIES HAVE INCREASED JUST ENOUGH THAT RED FLAG
WARNING CRITERIA IS NOT BEING REACHED ANY MORE. SO RED FLAG
WARNING WAS ALLOWED TO EXPIRE.
WITH THE MAIN LIFT AND INSTABILITY TO THE NORTH AND EAST OF THE
AREA...HAVE REMOVED THE REMAINING THUNDERSTORM AREA. COLD FRONT
HAS BEGUN TO MOVE THROUGH THE AREA. WINDS IN ADVANCE OF THE FRONT
WILL BE BREEZY TO LOW END WINDY WITH BRIEF BREEZY WINDS EXPECTED
BEHIND IT. ADJUSTED WINDS ACCORDING TO REALITY AND LATEST RUC
WHICH IS CLOSE TO THIS. RUC ALSO CLOSE ON DEWPOINTS AND ADJUSTED
WITH IT AS WELL. WITH EXPECTED WINDS...CURRENT MINS LOOK FINE AT
THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 148 PM MDT MON MAR 26 2012
GUSTY WINDS WILL CONTINUE INTO THE EVENING AS THE LOW PRESSURE
CENTER TO THE NORTH OF THE AREA MOVES FURTHER EASTWARD. A COLD
FRONT WILL MOVE THROUGH THE REGION DURING THE LATE
EVENING...SHIFTING WINDS TO THE NORTHWEST. AS HIGH PRESSURE BUILDS
IN BEHIND THE FRONT...WINDS WILL BECOME LIGHT. THE DRY LINE WILL
BECOME MORE DIFFUSE AFTER THE FRONT PASSES THROUGH...AND THE DRY
LINE WILL ALSO SHIFT EASTWARD OVERNIGHT. BY MID MORNING...THE COLD
FRONT WILL BE SOUTH AND EAST OF THE AREA. DAYTIME WINDS WILL BE
LIGHT OVER MUCH OF THE AREA DUE TO HIGH PRESSURE AT THE
SURFACE...BUT GUSTS ARE EXPECTED IN THE NORTHEASTERN PORTION OF
THE AREA AWAY FROM THE HIGH PRESSURE CENTER. THE WINDOW FOR GUSTS
AND LOW HUMIDITIES SHOULD BE LESS THAN THREE HOURS IN THE
AFTERNOON...SO THE NEED FOR A FIRE WEATHER HIGHLIGHT IS NOT
EXPECTED AT THIS TIME.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 103 AM MDT TUE MAR 27 2012
WEAK SYSTEM COMING OUT OF THE ROCKIES IN ZONAL FLOW ON FRIDAY MAY
BE ENOUGH FOR ISOLATED AFTERNOON/EVENING THUNDERSTORMS TH0UGH
CONFIDENCE IS LOW. SHORTWAVE RIDGING WILL BE IN PLACE OVER THE
WEEKEND WITH WARM AND DRY CONDITIONS. MODEL SOLUTIONS FOR THE NEXT
SYSTEM COMING OUT OF THE WEST AT THE END OF THE PERIOD VARY
GREATLY. HOWEVER IT DOES LOOK LIKE IT WILL IMPACT THE LOCAL AREA
SO WILL CARRY SLIGHT CHANCE POPS FOR NOW WITH THE FORECAST LIKELY
TO CHANGE OVER THE NEXT SEVERAL DAYS. THAT SYSTEM WILL BRING
COOLER TEMPERATURES...CLOSER TO NORMAL...FOR MONDAY AND TUESDAY.
IT COULD BE A PROLIFIC WIND MAKER AS WELL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1057 PM MDT MON MAR 26 2012
VFR CONDITIONS ARE EXPECTED TO BE VFR THROUGH THE PERIOD. A COLD
FRONT IS GOING THROUGH AT THIS TIME AND WILL BRIEFLY CAUSE THE WINDS
TO BE GUSTY. AFTER THE SUN COMES UP...THE WIND SPEEDS AND GUSTS WILL
INCREASE WITH THE STRONGEST WINDS EXPECTED AT KMCK. WINDS WILL DECREASE
FROM WEST TO EAST DURING THE LATE MORNING INTO EARLY AFTERNOON BEFORE
BECOMING LIGHT AND VARIABLE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...CJS
LONG TERM....024
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1100 PM MDT MON MAR 26 2012
.UPDATE...
ISSUED AT 914 PM MDT MON MAR 26 2012
UPDATE HAS BEEN COMPLETED. WINDS HAVE DECREASED ACROSS MOST OF THE
AREA. WITH A FEW SPOTS EXPECTED TO GUST CLOSE TO 40 TO 45 MPH FOR
A BRIEF TIME...DO NOT EXPECT WIND ADVISORY CRITERIA TO BE REACHED.
SO ADVISORY WAS ALLOWED TO EXPIRE. WINDS HAVE DECREASED AND
RELATIVE HUMIDITIES HAVE INCREASED JUST ENOUGH THAT RED FLAG
WARNING CRITERIA IS NOT BEING REACHED ANY MORE. SO RED FLAG
WARNING WAS ALLOWED TO EXPIRE.
WITH THE MAIN LIFT AND INSTABILITY TO THE NORTH AND EAST OF THE
AREA...HAVE REMOVED THE REMAINING THUNDERSTORM AREA. COLD FRONT
HAS BEGUN TO MOVE THROUGH THE AREA. WINDS IN ADVANCE OF THE FRONT
WILL BE BREEZY TO LOW END WINDY WITH BRIEF BREEZY WINDS EXPECTED
BEHIND IT. ADJUSTED WINDS ACCORDING TO REALITY AND LATEST RUC
WHICH IS CLOSE TO THIS. RUC ALSO CLOSE ON DEWPOINTS AND ADJUSTED
WITH IT AS WELL. WITH EXPECTED WINDS...CURRENT MINS LOOK FINE AT
THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 148 PM MDT MON MAR 26 2012
GUSTY WINDS WILL CONTINUE INTO THE EVENING AS THE LOW PRESSURE
CENTER TO THE NORTH OF THE AREA MOVES FURTHER EASTWARD. A COLD
FRONT WILL MOVE THROUGH THE REGION DURING THE LATE
EVENING...SHIFTING WINDS TO THE NORTHWEST. AS HIGH PRESSURE BUILDS
IN BEHIND THE FRONT...WINDS WILL BECOME LIGHT. THE DRY LINE WILL
BECOME MORE DIFFUSE AFTER THE FRONT PASSES THROUGH...AND THE DRY
LINE WILL ALSO SHIFT EASTWARD OVERNIGHT. BY MID MORNING...THE COLD
FRONT WILL BE SOUTH AND EAST OF THE AREA. DAYTIME WINDS WILL BE
LIGHT OVER MUCH OF THE AREA DUE TO HIGH PRESSURE AT THE
SURFACE...BUT GUSTS ARE EXPECTED IN THE NORTHEASTERN PORTION OF
THE AREA AWAY FROM THE HIGH PRESSURE CENTER. THE WINDOW FOR GUSTS
AND LOW HUMIDITIES SHOULD BE LESS THAN THREE HOURS IN THE
AFTERNOON...SO THE NEED FOR A FIRE WEATHER HIGHLIGHT IS NOT
EXPECTED AT THIS TIME.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 148 PM MDT MON MAR 26 2012
WEDNESDAY NIGHT-THURSDAY NIGHT...MORNING LOWS IN THE 40S TO LOW
50S WITH HIGHS ON THURSDAY IN THE 70S...NEAR 80 FROM HILL CITY TO
TRIBUNE. MAY SEE GUSTY NORTHWEST WINDS THURSDAY AFTERNOON AS A
WEAK COLD FRONT MOVES THROUGH. WILL MAINTAIN SOME SLIGHT CHANCE
POPS FOR THUNDERSTORMS LATE WEDNESDAY NIGHT AND AGAIN THURSDAY
AFTERNOON...MAINLY ACROSS THE FAR EAST AND SOUTH/SOUTHEAST.
FRIDAY-MONDAY...NOT TERRIBLY EXCITED ABOUT THE SMALL CHANCE OF
PRECIP ACROSS THE FAR EASTERN PART OF THE AREA FRIDAY AS A WEATHER
DISTURBANCE MOVES THROUGH BUT WILL KEEP IT IN FOR CONSISTENCY
SAKE. HIGHS IN THE LOW TO MID 70S. WEAK UPPER RIDGING BUILDS IN
FOR SATURDAY WITH HIGHS IN THE MID 70S AND DRY CONDITIONS.
FOR SUNDAY AND MONDAY THE GFS ROLLS AN UPPER TROUGH ACROSS THE
AREA WHILE THE ECMWF IS FAR LESS AMPLIFIED AT BEST. SHOULD SEE
HIGHS IN THE 70S SUNDAY WITH UPPER 50S TO LOW 60S MONDAY. CANT
RULE OUT SOME PRECIP BUT GIVEN THE UNCERTAINTY IT WAS DECIDED TO
KEEP IT DRY FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1057 PM MDT MON MAR 26 2012
VFR CONDITIONS ARE EXPECTED TO BE VFR THROUGH THE PERIOD. A COLD
FRONT IS GOING THROUGH AT THIS TIME AND WILL BRIEFLY CAUSE THE WINDS
TO BE GUSTY. AFTER THE SUN COMES UP...THE WIND SPEEDS AND GUSTS WILL
INCREASE WITH THE STRONGEST WINDS EXPECTED AT KMCK. WINDS WILL DECREASE
FROM WEST TO EAST DURING THE LATE MORNING INTO EARLY AFTERNOON BEFORE
BECOMING LIGHT AND VARIABLE.
&&
.FIRE WEATHER...
ISSUED AT 148 PM MDT MON MAR 26 2012
CRITICAL TO EXTREMELY CRITICAL FIRE WEATHER CONDITIONS ARE
EXPECTED TODAY...MAINLY ALONG AND WEST OF THE KANSAS AND COLORADO
STATE LINE AS A DRYLINE SLOWLY ADVANCES TO THE EAST TODAY. STRONG
SOUTHERLY WINDS OF 25 TO 35 MPH WITH GUSTS TO AROUND 55 MPH WILL
COMBINE WITH HUMIDITIES AROUND 10 PERCENT DURING THE AFTERNOON AND
EARLY EVENING HOURS. A COLD FRONT WILL BEGIN TO MOVE ACROSS THE
AREA TONIGHT...BRINGING A SUDDEN SHIFT IN THE WINDS AND A BRIEF
PERIOD OF STRONG NORTHWESTERLY WINDS.
A VERY DRY AIR MASS WILL SETTLE OVER THE AREA ON TUESDAY BRINGING
HUMIDITIES DOWN TO AROUND 15 PERCENT DURING THE AFTERNOON. WHILE
WINDS WILL BE LIGHT AND VARIABLE ACROSS MUCH OF THE AREA...THERE
IS POTENTIAL FOR STRONGER WINDS AND CRITICAL FIRE WEATHER
CONDITIONS ACROSS SOUTHWEST NEBRASKA. IF WINDS DO OCCUR...WILL
LIKELY BE A MUCH SMALLER MAGNITUDE OF EVENT THAN TODAY AND CHOSE
TO NOT ISSUE A FIRE WEATHER WATCH TO AVOID CONFUSION ABOUT TODAYS
WARNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...CJS
LONG TERM....007
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1006 PM EDT WED MAR 28 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS THE REGION THIS EVENING. HIGH PRESSURE
BUILDS OVER THE AREA THURSDAY AND FRIDAY. A LOW PRESSURE SYSTEM AND
ASSOCIATED COLD FRONT WILL AFFECT THE REGION LATE FRIDAY NIGHT
THROUGH SATURDAY. HIGH PRESSURE RETURNS SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
A WEAK COLD FRONT CONTINUES TO TRACK SOUTHWARD THIS AFTERNOON AND WILL
PASS THROUGH OUR FA MAINLY BETWEEN 00Z AND 06Z THIS EVENING. AN
INCREASED PRESSURE GRADIENT AHEAD OF THE FRONT IS RESULTING IN
WARM BUT WINDY CONDITIONS THIS AFTERNOON. GUSTS BETWEEN 30-35 MPH
WILL BE COMMON UNTIL SUNSET. CURRENT REGIONAL RADAR MOSAIC SHOWS A
BROKEN LINE OF SHOWERS AND TSTMS ALONG THE FRONT. LATEST HRRR AND
RUC FORECAST GUIDANCE HAS THE LINE MOSTLY DISSIPATING BEFORE
REACHING OUR NORTHERN AREAS AROUND SUNSET. WILL MAINTAIN SLIGHT CHC
POPS THROUGH THIS EVENING TO ACCOUNT FOR THE POSSIBILITY THAT THIS
ACTIVITY HOLDS TOGETHER BUT NOT OVERLY CONFIDENT THAT IT WILL BE
MUCH OF AN ISSUE GIVEN DRY LOW-LEVEL DOWNSLOPE FLOW AND LACK OF
INSTABILITY. ONCE THE FRONT DROPS SOUTH OF THE FA OVERNIGHT WILL
SEE WIND SHIFT TO THE NW. LOWS WILL BE MILDER THAN LAST NIGHT...IN
THE 50S TO LOW 60S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
HIGH PRESSURE OVER THE NORTHERN GREAT LAKES WILL BEGIN BUILDING SE
ON THURSDAY. SHOULD BE ENOUGH OF A PRESSURE GRADIENT BETWEEN LOW
PRESSURE OFF THE NEW ENGLAND COAST AND THE HIGH OVER THE GREAT
LAKES TO ALLOW FOR BREEZY NW WINDS (ESPECIALLY EASTERN AREAS
THROUGH MID AFTN). DRY AIRMASS BUILDING IN WITH THE SFC HIGH WILL
ALLOW FOR PLENTY OF SUNSHINE. LOW-LEVEL THICKNESS VALUES/H85 TEMPS
SUPPORT HIGHS FROM THE MID-60S ON THE LOWER MD EASTERN SHORE TO
THE LOW/MID 70S IN THE SW ZONES. TURNING CHILLY AGAIN THURSDAY
NIGHT WITH THE SFC HIGH BUILDING OVERHEAD AND DRY AIR IN PLACE. LOWS
IN THE UPR 30S TO LOW 40S. FOR FRIDAY...THE SFC HIGH MOVES
OFFSHORE AND ALLOWS FOR A S-SE FLOW. ANY PRECIP IS EXPECTED TO
REMAIN TO OUR SOUTH ALONG A WEAK WARM FRONT. AN ONSHORE COMPONENT
TO THE WIND WILL CAUSE THE COOLEST TEMPS TO BE NEAR THE COAST.
HIGHS WILL RANGE FROM NR 60 ON THE LWR MD EASTERN SHORE TO THE LOW
70S IN OUR SW ZONES. AN AREA OF LOW PRESSURE WILL TRACK ACROSS THE
REGION LATE FRIDAY NIGHT THROUGH SATURDAY MORNING BEFORE MOVING
OFFSHORE SATURDAY AFTERNOON. BEST CHANCE FOR PRECIP WILL BE ACROSS
OUR NORTHERN ZONES FRIDAY NIGHT...CLOSEST TO THE APPROACHING LOW.
WILL THEN CARRY LOW END CHC POPS ALL AREAS ON SATURDAY AS THE SFC
LOW TRAVERSES THE REGION. LOWS FRIDAY NIGHT IN THE UPR 40S TO MID
50S. HIGHS SATURDAY FROM THE 60S ON THE EASTERN SHORE TO THE
MID/UPR 70S IN OUR SW ZONES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A COLD FRONT IS EXPECTED TO DROP THROUGH THE MID ATLANTIC SATURDAY
NIGHT FOLLOWED BY HIGH PRESSURE BUILDING IN FROM THE NORTH LATE
SATURDAY NIGHT INTO SUNDAY. THERE IS SOME DISAGREEMENT AMONGST MODEL
GUIDANCE WITH RESPECT TO HOW QUICKLY THE HIGH MOVES OFF THE COAST
SUNDAY AFTERNOON. GIVEN THAT THE HIGH APPEARS RATHER WEAK WILL GO
WITH THE IDEA OF IT MOVING OFF THE COAST BY AFTERNOON WITH HIGH
TEMPERATURES REACHING THE UPPER 60S IN THE EASTERN SHORE TO MID 70S
IN THE PIEDMONT. LOW-LEVEL WARM AIR SURGES INTO THE REGION BY MONDAY
ALONG WITH DOWNSLOPE FLOW AND THIS WILL RESULT IN MUCH WARMER HIGH
TEMPERATURES. MAXIMA WERE RAISED INTO THE UPPER 70S TO LOW 80S WEST
OF THE BAY...BUT LATEST LOW-LEVEL THICKNESSES WOULD SUPPORT LOW TO
MID 80S INLAND. TUESDAY SHOULD REMAIN MILD AHEAD OF A COLD FRONT
APPROACHING FROM THE WEST. MOISTURE WITH THIS FRONT IS UNCERTAIN AT
THIS TIME...SO SLIGHT CHANCE POPS WILL BE MAINTAINED. MORE SEASONAL
TEMPERATURES SHOULD ARRIVE BEHIND THE FRONT FOR MIDWEEK.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
THE COLD FRONT CLEARS THE REGION LATER TONIGHT WITH A GUSTY NW
WIND DEVELOPING THURSDAY MORNING (ESPECIALLY NEAR THE COAST).
THERE IS A POTENTIAL FOR ANOTHER ROUND OF 15-20KT SUSTAINED WIND
WITH 25-30KT GUSTS.
EXPECT VFR CONDITIONS THURSDAY INTO FRI AS WEAK HIGH PRESSURE
BUILDS OVER THE AREA.
&&
.MARINE...
A COLD FRONT CROSSES THE MID ATLANTIC COAST TONIGHT FOLLOWED BY HIGH
PRESSURE BUILDING IN FROM THE NORTH THURSDAY. THE SW WIND OF TODAY
WILL DECLINE THIS EVENING...BEFORE SHIFTING TO THE NW AND INCREASING
ONCE AGAIN LATE. A MODESTLY STRONG NW WIND SHOULD CONTINUE DURING
THE DAY THURSDAY...BEFORE DIMINISHING THURSDAY NIGHT AS HIGH
PRESSURE SETTLES OVERHEAD. CURRENT SCA HEADLINES WILL BE MAINTAINED
AS IS...ALTHOUGH LATEST GUIDANCE SUGGEST SCA CONDITIONS COULD END
BEFORE THURSDAY NIGHT. HIGH PRESSURE SHIFTS OFFSHORE FRIDAY AS LOW
PRESSURE APPROACHES FROM THE WEST. THIS AREA OF LOW PRESSURE CROSSES
THE MARINE AREA FRIDAY NIGHT AND SATURDAY...WITH HIGH PRESSURE
RETURNING SATURDAY NIGHT INTO SUNDAY. HIGH PRESSURE SETTLES OFF THE
SOUTHEAST COAST EARLY NEXT WEEK.
&&
.FIRE WEATHER...
DRY AND BREEZY CONDITIONS ON THURSDAY MAY ENHANCE FIRE DANGER
ESPECIALLY IF THERE IS NOT ANY RAIN WITH THE WEAK COLD FRONTAL
PASSAGE TONIGHT. NW WINDS WILL AVERAGE 12-20 MPH THURSDAY WITH
GUSTS UP TO 25 MPH. THE STRONGEST WINDS ARE EXPECTED DURING THE
MORNING AND EARLY AFTERNOON. ALSO...RH VALUES ARE EXPECTED TO
TUMBLE THURSDAY AFTERNOON...LIKELY FALLING INTO THE 22-32 PERCENT
RANGE. AFTER COORDINATING WITH THE FIRE AGENCIES IN MD AND
VA...WILL NOT BE ISSUING ANY HEADLINES ATTM BECAUSE CONFIDENCE IS
NOT HIGH ENOUGH THAT WE SEE WIDESPREAD 20 MPH SUSTAINED
WINDS...ESPECIALLY DURING PEAK HEATING IN THE AFTERNOON. WILL SEE
HOW MUCH RAIN FALLS TONIGHT AND THEN WILL LIKELY ISSUE AN ENHANCED
FIRE DANGER STATEMENT FOR A PORTION OF OUR MD AND VA COUNTIES
EARLY THURSDAY MORNING.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT THURSDAY NIGHT FOR
ANZ630>634-656-658.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR ANZ650-652-654.
&&
$$
SYNOPSIS...JDM
NEAR TERM...JDM
SHORT TERM...JDM
LONG TERM...AJZ
AVIATION...AJZ/DAP
MARINE...AJZ
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
310 PM EDT TUE MAR 27 2012
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT EAST OF THE AREA AND ALLOW FOR DRY WEATHER
THROUGH TONIGHT. A COLD FRONT WILL RETURN SHOWERS WITH THE CHANCE OF
THUNDERSTORMS TO THE AREA ON WEDNESDAY. LINGERING SHOWERS WILL
DIMINISH EARLY ON THURSDAY WITH HIGH PRESSURE RETURNING DRY AND
SEASONABLE CONDITIONS FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE CENTERED
ACROSS THE TN/OH VALLEYS WITH THE UPPER OHIO VALLEY IN A
NORTHWESTERLY FLOW AHEAD OF THIS FEATURE. AT THE SURFACE, HIGH
PRESSURE IS CENTERED ALONG THE NC/VA BORDER. WITH A DEEP LAYER OF
DRY AIR ALOFT, SKIES ARE MOSTLY SUNNY AS CIRRUS BEGINS TO FILTER
INTO THE AREA FROM THE WEST.
TONIGHT...A COLD FRONT WILL APPROACH FROM THE WEST, WITH CLOUD
COVERAGE INCREASING AHEAD OF THIS FEATURE. 4KM NAM SUPPORTS THE
FIRST PRE-FRONTAL SHOWERS REACHING EASTERN OHIO BY DAYBREAK.
WITH WARM AIR ADVECTION ONGOING AHEAD OF THE FRONT, TEMPS WILL FALL
OFF SLIGHTLY OVERNIGHT WITH LOWS CLOSER TO MAV GUIDANCE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
THERE IS OPERATIONAL MODEL AGREEMENT THAT A SURFACE LOW WILL PASS
NORTH OF THE GREAT LAKES DURING THE DAY WEDNESDAY AND SWING A COLD
FRONT ACROSS THE AREA, LIKELY CLEARING EAST BY THE EVENING HOURS.
LIKELY POPS ARE FORECAST WITH PRE-FRONTAL SHOWERS PUSHING ACROSS
MUCH OF THE AREA BY 18Z. THE CHANCE OF THUNDER IS MENTIONED FROM
THE LATE MORNING INTO THE EVENING HOURS WITH AROUND 1000 J/KG
SBCAPE JUST AHEAD OF THE FRONT. WITH WARM AIR ADVECTION IN AN
ENHANCED SOUTHWESTERLY LOW-FLOW AHEAD OF THE FRONT, HIGH TEMPS
WILL BE AROUND 15 DEGREES ABOVE NORMAL, WITH SEVERAL LOCATIONS
SOUTH OF PITTSBURGH WARMING INTO THE 70S.
WEDNESDAY NIGHT THROUGH THURSDAY...FORECAST IS CLOSEST TO A
GFS/NAM BLEND AS COLD AIR ADVECTION BEGINS IN THE WAKE OF THE FRONT
AND THE LOW-LEVEL FLOW BECOMES NORTHWESTERLY. IN THIS PATTERN,
HAVE CHANCE POPS LINGERING ACROSS THE I-80 CORRIDOR UNTIL EARLY
THURSDAY. HIGH PRESSURE WILL THEN BEGIN TO BUILD IN FROM THE
NORTHWEST ON THURSDAY.
THURSDAY NIGHT...THE SURFACE HIGH WILL BUILD IN FROM THE
NORTHWEST, BECOMING CENTERED OVER THE REGION BY 12Z FRIDAY. WITH
CLEAR SKIES AND NEAR CALM WINDS THURSDAY NIGHT, THIS WILL ALLOW
FOR AN IDEAL RADIATIONAL COOLING SCENARIO. FORECAST LOWS THURSDAY
NIGHT ARE ON THE COOLER SIDE OF GUIDANCE, WITH THE MAJORITY OF THE
AREA DROPPING BELOW FREEZING AGAIN. WITH THIS IN MIND, HAVE
MENTIONED THE POTENTIAL FOR ANOTHER FREEZE IN THE HWO.
FRIDAY...A FRONTAL BOUNDARY WILL APPROACH FROM THE SOUTHWEST ON
FRIDAY WITH THE GFS INDICATING A SHORT WAVE MOVING INTO THE OHIO
VALLEY. WITH UNCERTAINTY IN FAIRLY ZONAL MID-LEVEL FLOW, HAVE CHANCE
OF SHOWERS BEGINNING FRIDAY AFTERNOON. WITH A FRONTAL BOUNDARY
CURRENTLY PROGGED TO REMAIN SOUTH OF THE AREA, HIGH TEMPS WILL
BE NEAR NORMAL SEASONAL VALUES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A RELATIVELY DEAMPLIFIED FLOW PATTERN SHOULD AT LEAST START THE
LONG TERM FORECAST PERIOD OVER THE CONUS AS TWO SPRAWLING UPPER
LOW CENTERS AND A VERY SUBDUED YET BROAD RIDGE ARCS ACROSS MOST OF
THE CONTINENT. THE END RESULT LOOKS TO BE A FAIRLY HIGH SPEED FLOW
PATTERN OVER THE COUNTRY...INCLUDING OUR REGION. EMBEDDED IN THIS
FAST FLOW LOOKS TO BE A SYSTEM THAT SHOULD BEGIN TO AFFECT THE
AREA BY FRIDAY NIGHT...WITH A COLD FRONT SAGGING THROUGH THE AREA
ON SATURDAY. MODEL GUIDANCE IS FAIRLY WELL CLUSTERED WITH THIS
SYSTEM...ESPECIALLY CONSIDERING THE FLAT FLOW PATTERN THAT WILL BE
PREVAILING BY THIS TIME. IN ASSOCIATION WITH THIS SYSTEM...VERY
SUBDUED 250 MB JET COUPLING IS PRESENT ALONG WITH A COMPACT AREA
OF DIFFERENTIAL PVA AHEAD OF THE 500 MB SHORT WAVE TROUGH. THIS
SETS THE STAGE FOR A FAIRLY COMPACT YET IMPRESSIVE OMEGA SIGNATURE
ALONG THE FRONT AS IT CROSSES THE REGION ON FRIDAY NIGHT INTO
EARLY SATURDAY. AS A RESULT...POPS WERE INCREASED FOR THIS
PERIOD...HOWEVER LIKELY POPS WERE STILL KEPT OUT OF THE FORECAST
GIVEN TIMING CHALLENGES IN A FLATTER FLOW PATTERN.
AFTER FRIDAY NIGHT/SATURDAY`S SYSTEM CHARGES EASTWARD...DRIER AND
WARMER CONDITIONS SURGE BACK INTO THE REGION AS FLOW OVER THE
CONUS AGAIN AMPLIFIES GREATLY AS A DEEP UPPER TROUGH AGAIN TAKES
RESIDENCE OVER THE INTERMOUNTAIN WEST. THE RESULT IS A SPRAWLING
UPPER RIDGE THAT FIRST BUILDS OVER THE UPPER MIDWEST THEN SHIFTS
EAST TOWARD THE MIDDLE ATLANTIC BY EARLY NEXT WORK WEEK. UNDER THE
RIDGE BY MONDAY AFTERNOON...850 MB TEMPERATURES SOAR TOWARD +15C
WITH INCREASED MIXING AHEAD OF THE UPPER LOW THAT BY THEN WILL
HAVE MOVED INTO THE LOWER MISSOURI VALLEY. WITH THE RIDGE AXIS
HAVING GENERALLY SHIFTED JUST TO THE EAST OF THE AREA...DEEP LAYER
SOUTHERLY FLOW OVER THE REGION...AND A FAIRLY WELL-MIXED
PROFILE...MONDAY SHOULD BE THE WARMEST DAY OF THE FORECAST PERIOD.
AFTER MONDAY...THE UPPER LOW MOVES EASTWARD TOWARD THE
REGION...AND THE CHANCES OF SHOWERS AND THUNDERSTORMS LOOK TO
INCREASE AS TEMPERATURES FALL BACK A BIT. FRIES
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
THIN CIRRUS HAS BEGUN ITS ADVANCE INTO THE REGION THIS
AFTERNOON...WHILE THICKER MID-LEVEL CLOUDS REMAIN WELL TO THE WEST
OF THE REGION. THESE CLOUDS WILL TAKE UNTIL LATE INTO TONIGHT
BEFORE THEY REACH ANY OF THE SITES...AND RAIN SHOWERS SEEM LIKELY
TO HOLD OFF UNTIL AROUND DAYBREAK. A COLD FRONT PASSES THROUGH THE
SITES SHORTLY AFTER MIDDAY WEDNESDAY...WITH BRISK WEST TO
SOUTHWEST WINDS LIKELY AT ALL SITES BY AFTERNOON.
OUTLOOK...WEDNESDAY AFTERNOON THROUGH SUNDAY...
CONDITIONS ARE LIKELY TO IMPROVE WEDNESDAY AFTERNOON BEHIND THE
SYSTEM...WITH DRY/VFR WEATHER PREVAILING UNTIL THE NEXT SYSTEM
ARRIVES ON FRIDAY NIGHT/SATURDAY. FRIES
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
205 PM EDT TUE MAR 27 2012
.SYNOPSIS...
CANADIAN HIGH PRESSURE WILL PROVIDE SUNSHINE TODAY AND SEASONABLE
TEMPERATURES THIS AFTERNOON. A LOW PRESSURE SYSTEM COMING
SOUTHEAST FROM THE DAKOTAS WILL BRING MILD SHOWERY CONDITIONS
WEDNESDAY, FOLLOWED BY DRY, SEASONABLE CONDITIONS INTO THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE 18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO
ACCOUNT FOR THE LATEST TRENDS IN TEMP AND DEW POINT.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE CENTERED
ACROSS THE THE TN/OH VALLEYS WITH THE UPPER OHIO VALLEY IN A
NORTHWESTERLY FLOW AHEAD OF THIS FEATURE. AT THE SURFACE, HIGH
PRESSURE IS CENTERED ALONG THE NC/VA BORDER. WITH A DEEP LAYER OF
DRY AIR ALOFT, SKIES ARE CLEAR WITH ABUNDANT SUNSHINE THIS
AFTERNOON.
TODAY...MID-LEVEL RIDGING WILL SHIFT INTO THE UPPER OHIO VALLEY
WITH THE SURFACE HIGH MOVING INTO THE MID-ATLANTIC. WITH THE LOW-
LEVEL FLOW SHIFTING TO MORE SOUTHEASTERLY, WARM AIR ADVECTION IN
COMBO WITH ABUNDANT SUNSHINE WILL AID A QUICK RECOVERY IN TEMPS
TODAY. TEMPS ARE A BLEND OF LAMP/HRRR GUIDANCE, WITH HIGHS RANGING
FROM NEAR 50 ALONG THE I-80 CORRIDOR TO NEAR 60 IN PORTIONS OF
NORTH-CENTRAL WV.
TONIGHT...A COLD FRONT WILL APPROACH FROM THE WEST, WITH CLOUD
COVERAGE INCREASING AHEAD OF THIS FEATURE. 4KM NAM SUPPORTS THE
FIRST PRE-FRONTAL SHOWERS REACHING EASTERN OHIO NEAR DAYBREAK.
WITH WARM AIR ADVECTION ONGOING AHEAD OF THE FRONT, TEMPS WILL FALL
OFF SLIGHTLY OVERNIGHT WITH LOWS CLOSER TO THE WARMER MAV
GUIDANCE.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW A LOW PRESSURE SYSTEM
MOVING SOUTHEASTWARD THROUGH THE GREAT LAKES WEDNESDAY. PREFRONTAL
SHOWERS MAY AFFECT THE UPPER OHIO VALLEY LATE TUESDAY NIGHT AND
WEDNESDAY, WITH POSSIBLY AFTERNOON THUNDERSTORMS. RECENT SATELLITE
DATA SHOWS THIS SYSTEM INGESTING MOISTURE FROM THE TROPICAL
PACIFIC.
POST SYSTEM COOL DOWN MAY CAUSE LINGERING CLOUDS INTO WEDNESDAY
NIGHT.
FORECASTED MILD TEMPERATURES THIS PERIOD PER RECENT GFS AND NAM MOS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
BLEND OF RECENT GFS AND ECMWF MODEL OUTPUT SHOW POST SYSTEM
NORTHWEST FLOW MAINTAINING CLOUDS ACROSS THE UPPER OHIO VALLEY
THURSDAY AND FRIDAY. A LOW PRESSURE SYSTEM COMING EAST FROM THE
PLAINS WILL PROVIDE A CHANCE OF SHOWERS SATURDAY WITH CLOUDS
LINGERING INTO SUNDAY.
FORECASTED TEMPERATURES TO BE SEASONABLE THURSDAY AND THEN BECOME AS
MUCH AS 10 DEGREES WARMER THAN NORMAL FRIDAY INTO MONDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
CLEAR SKIES WILL SLOWLY GIVE WAY TO INCREASING HIGH CLOUDS THROUGH
THE DAY. MORE MID-CLOUDS WILL MOVE IN TOWARD THE EARLY MORNING HOURS
OF WEDNESDAY...HOWEVER ALL LOCATIONS SHOULD REMAIN VFR THROUGH THE
TAF VALID PERIOD. PRECIPITATION SHOULD HOLD OFF UNTIL SHORTLY AFTER
28/12Z.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
PREFRONTAL SHOWERS MAY PRODUCE RESTRICTIONS LATE TONIGHT AND
WEDNESDAY. POST SYSTEM COOLING MAY CAUSE CEILING RESTRICTIONS TO
LINGER INTO THURSDAY. A FRONTAL BAND OF SHOWERS MAY PROVIDE A PERIOD
OF RESTRICTIONS SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1016 AM EDT TUE MAR 27 2012
.SYNOPSIS...
CANADIAN HIGH PRESSURE WILL PROVIDE SUNSHINE TODAY AND SEASONABLE
TEMPERATURES THIS AFTERNOON. A LOW PRESSURE SYSTEM COMING
SOUTHEAST FROM THE DAKOTAS WILL BRING MILD SHOWERY CONDITIONS
WEDNESDAY, FOLLOWED BY DRY, SEASONABLE CONDITIONS INTO THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
A MID-MORNING UPDATE HAS BEEN ISSUED TO REMOVE FREEZE WARNING
HEADLINES AND TO INCREASE TEMPS A FEW DEGREES FOR HIGHS TODAY.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE CENTERED
ACROSS THE GREAT LAKES REGION WITH THE UPPER OHIO VALLEY IN A
NORTHWESTERLY FLOW AHEAD OF THIS FEATURE. AT THE SURFACE, A
1030MB HIGH IS CENTERED OVER WESTERN PENNSYLVANIA. THE 12Z KPIT
SOUNDING INDICATES DEEP SUBSIDENCE ALOFT. THUS, SKIES ARE CLEAR WITH
ABUNDANT SUNSHINE ALLOWING FOR TEMPERATURES TO RECOVER QUICKLY
THIS MORNING.
TODAY...MID-LEVEL RIDGING WILL SHIFT INTO THE UPPER OHIO VALLEY
WITH THE SURFACE HIGH MOVING INTO THE MID-ATLANTIC. WITH THE LOW-
LEVEL FLOW SHIFTING TO MORE SOUTHEASTERLY, WARM AIR ADVECTION IN
COMBO WITH ABUNDANT SUNSHINE WILL AID A QUICK RECOVERY IN TEMPS
TODAY. TEMPS ARE A BLEND OF LAMP/HRRR GUIDANCE, WITH HIGHS RANGING
FROM NEAR 50 ALONG THE I-80 CORRIDOR TO NEAR 60 IN PORTIONS OF
NORTH-CENTRAL WV.
TONIGHT...A COLD FRONT WILL APPROACH FROM THE WEST, WITH CLOUD
COVERAGE INCREASING AHEAD OF THIS FEATURE. 4KM NAM SUPPORTS THE
FIRST PRE-FRONTAL SHOWERS REACHING EASTERN OHIO NEAR DAYBREAK.
WITH WARM AIR ADVECTION ONGOING AHEAD OF THE FRONT, TEMPS WILL FALL
OFF SLIGHTLY OVERNIGHT WITH LOWS CLOSER TO THE WARMER MAV
GUIDANCE.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW A LOW PRESSURE SYSTEM
MOVING SOUTHEASTWARD THROUGH THE GREAT LAKES WEDNESDAY. PREFRONTAL
SHOWERS MAY AFFECT THE UPPER OHIO VALLEY LATE TUESDAY NIGHT AND
WEDNESDAY, WITH POSSIBLY AFTERNOON THUNDERSTORMS. RECENT SATELLITE
DATA SHOWS THIS SYSTEM INGESTING MOISTURE FROM THE TROPICAL
PACIFIC.
POST SYSTEM COOL DOWN MAY CAUSE LINGERING CLOUDS INTO WEDNESDAY
NIGHT.
FORECASTED MILD TEMPERATURES THIS PERIOD PER RECENT GFS AND NAM MOS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
BLEND OF RECENT GFS AND ECMWF MODEL OUTPUT SHOW POST SYSTEM
NORTHWEST FLOW MAINTAINING CLOUDS ACROSS THE UPPER OHIO VALLEY
THURSDAY AND FRIDAY. A LOW PRESSURE SYSTEM COMING EAST FROM THE
PLAINS WILL PROVIDE A CHANCE OF SHOWERS SATURDAY WITH CLOUDS
LINGERING INTO SUNDAY.
FORECASTED TEMPERATURES TO BE SEASONABLE THURSDAY AND THEN BECOME AS
MUCH AS 10 DEGREES WARMER THAN NORMAL FRIDAY INTO MONDAY.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
CLEAR SKIES WILL SLOWLY GIVE WAY TO INCREASING HIGH CLOUDS THROUGH
THE DAY. MORE MID-CLOUDS WILL MOVE IN TOWARD THE EARLY MORNING HOURS
OF WEDNESDAY...HOWEVER ALL LOCATIONS SHOULD REMAIN VFR THROUGH THE
TAF VALID PERIOD. PRECIPITATION SHOULD HOLD OFF UNTIL SHORTLY AFTER
28/12Z.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
PREFRONTAL SHOWERS MAY PRODUCE RESTRICTIONS LATE TONIGHT AND
WEDNESDAY. POST SYSTEM COOLING MAY CAUSE CEILING RESTRICTIONS TO
LINGER INTO THURSDAY. A FRONTAL BAND OF SHOWERS MAY PROVIDE A PERIOD
OF RESTRICTIONS SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
749 PM EDT WED MAR 28 2012
.SYNOPSIS...
ISSUED AT 355 PM EDT WED MAR 28 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE UPR GRT LKS DOWNSTREAM OF UPR RIDGE IN THE PLAINS. SHRTWV/SFC LO
THAT IMPACTED THE AREA YDAY IS NOW MOVING E THRU QUEBEC...BUT CYC
SFC-H85 NW FLOW OF MOIST AIR REMAINS IN PLACE OVER THE UPR GRT LKS.
A SHRTWV OVER MN IS MOVING SEWD...AND IN CONCERT WITH SOME DEEPER
MSTR SHOWN ON THE 12Z INL RAOB HAS CAUSED SOME SCT -SHRA THAT ARE
MIXING WITH SN AS COLDER AIR ARRIVES FM THE NW...WHERE THE 12Z H85
TEMP WAS AS LO AS -9C AT YPL. BUT UPSTREAM RAOBS SHOW MID LVL DRYING
IN THE WAKE OF THE SHRTWV IS SPREADING SEWD TOWARD THE UPR GRT LKS.
DESPITE THE HIER LVL DRYING...MUCH LO CLD LINGERS IN THE LLVL CYC
FLOW OF THE MOISTER LLVLS DEPICTED ON THE 12Z INL/YPL RAOBS. SOME
CLEARING IS SHOWING UP OVER MANITOBA CLOSER TO DRIER LLVL AIR SHOWN
ON THE 12Z THE PAS RAOB AND SFC HI PRES/RDG AXIS UNDER THE UPR RDG.
FARTHER TO THE W...A STRONG DISTURBANCE HAS COME ASHORE INTO THE PAC
NW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 355 PM EDT WED MAR 28 2012
MAIN FCST CONCERNS IN THIS PERIOD ARE CLD/CLEARING TRENDS AND TEMPS.
TNGT...UPR RDG/SFC HI PRES RDG AXIS TO THE W ARE FCST TO BUILD INTO
THE UPR GRT LKS. WITH MORE ACYC FLOW AND SOME DRYING...EXPECT AT
LEAST PARTIAL CLRG ESPECIALLY IN DOWNSLOPE AREAS AWAY FM LK SUP IN
SLOWLY VEERING FLOW TO MORE NNE BY 12Z THU. BUT EXTENSIVE CLD COVER
UPSTREAM/LINGERING H925 THERMAL TROF SUGS THE SC WL BE MORE
RESILIENT IN UPSLOPE AREAS NEAR THE LAKE UNDER STRENGTHENING INVRN
ASSOCIATED WITH LARGER SCALE SUBSIDENCE. EXPECT THE LOWEST MIN TEMPS
WELL DOWN IN THE 20S OVER THE INTERIOR W WHERE MORE EXTENSIVE CLRG
IS MOST LIKELY.
THU...AS HI PRES IN ONTARIO DRIFTS SLOWLY TO THE E AND DISTURBANCE
NOW IN THE PAC NW/SFC LO MOVE TOWARD MN LATE...THE LLVL FLOW WL VEER
TO THE E THRU THE DAY. LINGERING LK SC SHOULD SHIFT TO MAINLY OVER
THE HURON MTNS/KEWEENAW AS MID/HIER CLD IN ADVANCE OF APRCHG
DISTURBANCE ARRIVE IN THE AFTN. THE GFS IS MOST AGGRESSIVE AT MOVING
PCPN E INTO THE WRN CWA IN THE AFTN...BUT WL FOLLOW THE SLOWER 12Z
NAM/CNDN/UKMET AND 00Z ECWMF WITH VERY DRY AIRMASS ASSOCIATED WITH
HUDSON BAY HI PRES IN PLACE AND GFS FCST SHARPER QVECTOR CNVGC/FGEN
HOLDING FARTHER TO THE W. MIXING TO H85 ON NAM FCST SDNGS YIELDS HI
TEMPS APRCHG 45 AWAY FM LK MODERATION.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM EDT WED MAR 28 2012
THURSDAY NIGHT INTO FRIDAY...SHORTWAVE TROUGH OVER THE NORTHERN
PLAINS POISED TO SLIDE THROUGH THE WESTERN GREAT LAKES BY LATE
THURSDAY NIGHT. INITIALLY JUST TO THE WEST OF CWA LARGE SCALE LIFT
FM THE SHORTWAVE IS COMPLEMENTED NICELY BY 925-850MB WARM AIR
ADVECTION AND DIVERGENCE ALOFT FM JET STREAK OVR ONTARIO. ALL THIS
FORCING IS ACTING ON RATHER MOIST AIRMASS WITH PWATS UP TOWARD 200
PCT OF NORMAL. SINCE PRIMARY SHORTWAVE IS SLIDING MAINLY SOUTH OF
UPR MI AND RIGHT ENTRANCE REGION/H85 THERMAL GRADIENT FADES THROUGH
THE NIGHT...WOULD EXPECT PCPN TO LIGHTEN AS IT MOVES INTO THE CWA
OVERNIGHT. FCST SOUNDINGS POINT TO PTYPE MAINLY TAKING THE FORM OF
SNOW WITH VERY LITTLE IN WAY OF NEAR SFC WARM LAYER ON SOUNDINGS.
BASED ON PREVIOUS MODEL RUNS THIS REPRESENTS A TREND IN THE COOLER
DIRECTION. EXPLICIT QPF OUTPUT WITH THE COLDER TREND WOULD SUGGEST A
FEW INCHES OF SNOW POSSIBLE IN THE INTERIOR WEST OVERNIGHT THURSDAY
NIGHT INTO EARLY FRIDAY. WILL NOT GO WITH THAT MUCH QPF/SNOW YET
THOUGH BASED ON NEGATIVE FACTORS MENTIONED BEFORE. STILL...COULD
SEE AROUND AN INCH OF SNOW OVER INTERIOR WEST AND SCNTRL. MAJORITY
OF PCPN SHOULD EXIT THE SCNTRL/EASTERN CWA FRIDAY AFTN. PLENTY OF
CLOUDS WITH THE PCPN ALONG WITH SE WIND OFF LK MICHIGAN WILL HOLD
DOWN TEMPERATURES OVR MOST OF THE CWA IN THE LOWER-MID 40S.
SHORTWAVE TROUGH SLIDES BY OVER CNTRL CANADA ON SATURDAY BUT MAIN
IMPACTS FM DISTURBANCE FCST TO REMAIN MOSTLY NORTH OF CWA WHERE BEST
LOW-LEVEL WARM ADVECTION OCCURS AND ALONG AND EAST OF TRACK OF
SHORTWAVE. DO HAVE SOME SMALL CHANCES FOR SHOWERS /JUST RAIN AT THIS
POINT/ OVER LK SUPERIOR AND IN NORTHERN CWA ON SATURDAY NIGHT.
IN THE EXTENDED...PIECE OF BROAD UPPER TROUGH OVER THE NORTHERN
PACIFIC IS FORECAST TO EJECT ACROSS THE ROCKIES ON SUNDAY. TROUGH
AND ASSOCIATED DEEPENING SFC LOW THEN SLIDE INTO THE UPR LAKES ON
MONDAY. DETERMINISTIC MEDIUM RANGE MODELS /GFS/ECMWF/CANADIAN/
INDICATE THAT THE UPPER LOW SLOWS UP EARLY NEXT WEEK AND MAY EVEN
TRY TO CUT OFF OVR UPR LAKES AND/OR ONTARIO. NCEP PREFERS THE SLOWER
APPROACH AS MODELS HAVE TRENDED THAT WAY. EVENTUALLY GENERAL RESULT
WILL BE COOLER AND UNSETTLED WEATHER PATTERN THROUGH MIDDLE OF NEXT
WEEK. INITIALLY THOUGH...MONDAY COULD BE ON THE WARMER SIDE OUT
AHEAD OF UPR LOW. ECMWF AND GFS DIFFER ON DETAILS AS GFS SHOWS MUCH
MORE IN WAY OF CLOUDS AND LIGHTER QPF SUNDAY NIGHT INTO MONDAY
MORNING WHILE ECMWF INDICATES A SHARPER COLD FRONT WITH GREATER
POTENTIAL FOR CONVECTION JUST AHEAD OF THE FRONT WITH H7-H5 LAPSE
RATES TO 7C/KM AND SI/S BLO 0C. THERE ALSO APPEARS TO BE ENHANCED
CONVECTIVE POTENTIAL DUE TO SHARPER 1000-850MB MOISTURE FLUX
CONVERGENCE FCST IN AFTN DURING PEAK HEATING. LATEST GFS HAS TRENDED
WARMER WITH INCREASED CHANCE OF CONVECTION. HAVE INTRODUCED CHANCES
FOR THUNDER...FIRST ON SUNDAY NIGHT FOR POSSIBLE ELEVATED CONVECTION
ON EDGE OF INSTABILITY GRADIENT AND THEN ON MONDAY WITH THE FROPA.
COLDER AIR WORKS IN FOR TUESDAY AND WEDNESDAY. GFS IS BROADER AND
LESS AMPLIFIED WITH OVERALL TROUGH WHILE ECMWF INDICATES COOLER AIR
SLOWLY MOVING IN ON TUESDAY WITH STRONGER SHOT OF COLD AIR ARRIVING
BY WEDNESDAY WITH SHARPER COLD FRONT FCST. ALTHOUGH CONSISTENCY IN
HANDLING OF THE TROUGH FM THE MODELS HAS BEEN MUDDLED...DOES APPEAR
TO BE A TREND IN HOLDING ON TO THE TROUGH LONGER AND KEEPING COOLER
TEMPERATURES OVER GREAT LAKES LONGER FURTHER INTO THE WEEK. TREND
MAKES SOME SENSE GIVEN THE AMPLIFIED PATTERN THAT APPEARS TO BE
SETTING UP COMPARED TO MORE ZONAL PATTERN IN PLACE CURRENTLY.
LATEST ECMWF SLOWER YET IN KEEPING COOL TROUGHING OVER GREAT LAKES
AND NORTHEAST INTO LATE NEXT WEEK. TRYING TO PIN DOWN DETAILS TOUGH
AT THIS POINT...BUT THIS KIND OF PATTERN WOULD HAVE POTENTIAL TO
BRING RAIN/SNOW SHOWERS TO UPR LAKES...ENHANCED BY DAYTIME HEATING
AND/OR ANY SHORTWAVES MOVING AROUND THE TROUGH. CONSENSUS POPS SHOW
SMALL CHANCES THROUGH MUCH OF THE EXTENDED WHICH SEEMS ON TRACK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 748 PM EDT WED MAR 28 2012
ALTHOUGH MORE ACYC FLOW/SOME LOW LEVEL DRYING WILL RESULT KEEP VFR
CONDITIONS AT CMX/IWD. HOWEVER...MVFR CONDITIONS SHOULD LINGER
TONIGHT THROUGH THU MORNING AT KSAW WHERE MORE UPSLOPE FLOW
PREVAILS. A RETURN TO MVFR CIGS MAY ALSO BE POSSIBLE AT KCMX AS
WINDS BACK MORE TO THE ENE. BY THURSDAY AFTERNOON...EXPECT ANY
LINGERING MVFR CIGS TO SCATTER OUT AS MIXING/DRYING INCREASES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT WED MAR 28 2012
EXPECT NW WINDS UP TO 30 KTS EARLY OVER THE E HALF TO DIMINISH
TONIGHT AS HI PRES RIDGE BUILDS OVERHEAD. AS THE HI CENTER SHIFTS
EWD TOWARD HUDSON BAY ON THU...A STRONGER E WIND UP TO 25 KTS WILL
DEVELOP OVER WESTERN LK SUP WHERE TERRAIN ENHANCES THIS FLOW. GUSTY
EAST WINDS SHOULD CONTINUE ON THE LAKE INTO FRIDAY MORNING. AFTER A
BRIEF LULL...SOUTH WINDS INCREASE TO 30 KTS ON EAST HALF OF LK
SUPERIOR BY SATURDAY AFTN. WINDS SHOULD SETTLE DOWN INTO SUNDAY AS
PRESSURE GRADIENT WEAKENS. ANOTHER LOW PRESSURE SYSTEM...POSSIBLY
SLOW MOVING...IS EXPECTED TO AFFECT THE WESTERN GREAT LAKES EARLY
NEXT WEEK. COULD SEE WINDS UP TO 30 KTS WITH THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
411 PM EDT TUE MAR 27 2012
.SYNOPSIS...
ISSUED AT 408 PM EDT TUE MAR 27 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW POTENT NEGATIVELY
TILTED SHRTWV/STACKED LO MOVING ENEWD THRU NRN MN ON TOP OF MEAN RDG
OVER THE SE CONUS. PCPN/WARM CONVEYOR BELT WELL E OF THE LO HAS
MOVED E OF THE CWA...BUT LO CLDS LINGER IN THE RELATIVELY MOIST LYR
ASSOCIATED WITH SHARP WAD INVRN DEPICTED ON THE 12Z RAOBS. SKIES ARE
MOCLR OVER MN UNDER THE DRY SLOT/JET SURGE REGION OF THE LO...AND
TEMPS HAVE RISEN WELL INTO THE 50S AND 60S IN THAT AREA. DESPITE
THIS SHARP WAD STABILITY...GUSTY S WINDS UP TO 50 MPH UNDER SHARP
PRES GRADIENT BTWN THE LO AND RETREATING HI PRES OVER SE ONTARIO
HAVE IMPACTED LOCATIONS NEAR THE LK SUP SHORE...PROMPTING ISSUANCE
OF WIND ADVY. IN FACT...THE 12Z MPX RAOB INDICATED A WIND SPEED OF
61KTS AT 3K FT AGL WITHIN THE STABLE INVRN LYR. THE S WIND OFF THE
RELATIVELY CHILLY LK MI WATERS HAVE ENHANCED THE LLVL STABILITY AND
PREVENTED THE WINDS IN THAT AREA FM BEING AS STRONG AS NEAR LK SUP.
FARTHER TO THE W...DEEP WRAP ARND MSTR SHOWN ON THE 12Z BISMARCK
RAOB IS MOVING INTO NW NW IN THE WAKE OF THE DEPARTING LO.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 408 PM EDT TUE MAR 27 2012
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON WINDS/CLD TRENDS AND
PSBL WRAP ARND -SHRA AS MN LO MOVES ACRS NRN LK SUP AND INTO SE
ONTARIO ON WED.
TNGT...SHRTWV/CLOSED LO IN MN ARE PROGGED TO MOVE INTO SE ONTARIO
JUST NE OF THE SAULT BY 12Z WED. AS THE PRES GRADIENT WEAKENS AT
LEAST TEMPORARILY WITH THE APRCH OF THE SFC LO...EXPECT WINDS TO
DIMINISH LATE THIS AFTN/EARLY EVNG. SO WL LET THE GOING WIND ADVY
EXPIRE AT 21Z AS SCHEDULED. ALTHOUGH THE EARLY EVNG WL BE PCPN FREE
FOR THE MOST PART UNDER DRY SLOT...MORE CLDS/SCT -SHRA WL ARRIVE FM
THE W AS THE WRAP ARND MSTR ACCOMPANYING THE EWARD MOVING LO PRES
SLIDES INTO THE UPR LKS. STRONG W H925 WINDS UP TO 40-50 KTS ON THE
WRN FLANK OF THE LO WL ADVECT MUCH COOLER AIR INTO THE AREA...WITH
H85 TEMPS FCST AS LO AS -2C OR -3C OVER THE W BY 12Z...BUT FCST WBLB
ZERO HGT WELL ABV 1K FT SUGS THE PCPN WL REMAIN MAINLY IN THE FORM
OF RA EXCEPT OVER THE HIER TERRAIN OF THE W LATE. EXPECT STRONG W
WINDS TO IMPACT THE W LATE AS WELL...WITH WIND GUSTS APRCHG ADVY LVL
AGAIN OVER THE FAR W S OF CMX WHERE THE CORE OF STRONGEST WINDS
COINCIDES WITH THE INCOMING H85 THERMAL TROF. CONSIDERED EXTENDING
WIND ADVY FOR THE KEWEENAW...BUT AXIS OF STRONGER WINDS POINTING
TOWARD THIS EXPOSED AREA DOES NOT COINCIDE WITH THERMAL TROFFING/
REDUCED STABILITY THAT WOULD ENHANCE MIXING.
WED...AS THE CLOSED LO TO THE E MOVES FARTHER AWAY...SFC HI PRES RDG
WL BLD INTO THE AREA UNDER RISING H5 AHEAD OF PROGRESSIVE UPR RDG IN
THE PLAINS. MRNG -SHRA...MIXED WITH SN PER LOWER WBLB ZERO HGTS AS
H85 TEMPS FALL TO ARND -5C...MAINLY IN THE UPSLOPE AREAS OVER THE
NRN TIER WL DIMINISH WITH TIME UNDER NEGATIVE DYNAMICS/MID LVL
DRYING AND GRDLY MORE ACYC FLOW... BUT FCST SDNGS SUG PLENTY OF LO
CLD WL LINGER...SO TENDED TOWARD THE LOWER END OF GUIDANCE FOR
TEMPS. AS THE LO MOVES AWAY AND HI PRES MOVES TOWARD THE AREA...THE
WINDS WL DIMINISH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 408 PM EDT TUE MAR 27 2012
WED NIGHT...H925 TEMPS AROUND -6C WILL LEAD TO ENOUGH LK INSTABILITY
TO KEEP CLOUDS GOING THROUGH MUCH OF THE NIGHT FOR LOCATIONS FAVORED
BY VEERING N TO NE WINDS NEAR LK SUPERIOR. LINGERED SLIGHT CHANCES
THROUGH THE EVENING FOR THE NRLY FAVORED LOCATIONS BEFORE
DIMINISHING IT OVERNIGHT. DID HOLD ON TO THE SLIGHTS LONGER FOR THE
UPSLOPE LOCATIONS IN NCNTRL UPPER MI...ALTHOUGH THE LOWERING
INVERSION WILL LIMIT CLOUD DEPTH.
THURS SHOULD BE A SIMILAR DAY TO YESTERDAY WITH HUDSON BAY HIGH
PRESSURE RIDGE OVER UPPER MI. NE WINDS WILL PULL DRIER AIR INTO
UPPER MI AND LEAD TO A MOSTLY SUNNY DAY OVER THE EAST HALF. FARTHER
WEST...MID CLOUDS WILL BE WORKING OVER THE AREA THROUGH THE
AFTERNOON...ALONG WITH SOME SHOWERS OVER WRN LK SUPERIOR...AHEAD OF
THE APPROACHING SHORTWAVE. HIGHS WILL BE WARMEST INTERIOR AWAY FROM
THE LK SUPERIOR INFLUENCE...WHICH WILL ALLOW FOR DEEPER MIXING AND
HIGHS RISING INTO THE MID-UPPER 40S. OTHERWISE...LOCATIONS NEAR LAKE
SUPERIOR WILL BE IN THE UPPER 30S AND LOWER 40S. DEWPOINTS ARE THE
MAIN ADJUSTMENT TO THE FORECAST...AS MODELS ARE COMING INTO BETTER
AGREEMENT WITH ML DEWPOINTS FALLING INTO THE SINGLE DIGITS ABOVE
ZERO OVER THE ERN CWA. WILL DROP TD VALUES AGAIN SEVERAL DEGREES
OVER THE ERN CWA INTO THE UPPER TEENS. MAY NEED TO DROP THEM EVEN
MORE...SINCE MIXED LAYER DEWPOINTS VERIFIED FAIRLY WELL YESTERDAY.
THURS NIGHT...CLEAR INITIALLY AND WITH THE LIGHT WINDS OVER THE ERN
CWA...SHOULD SEE A QUICK FALL IN TEMPS DURING THE EVENING HOURS. BUT
INCREASING CLOUDS AHEAD OF THE APPROACHING SHORTWAVE WILL CAUSE THE
TEMPS TO RISE THROUGH THE NIGHT. TRIED TO SHOW A QUICK DROP IN
THE EVENING...BUT UNSURE THE AMOUNT OF WARMING WITH LIMITED
WINDS AND MAINLY MID-HIGH CLOUDS...SO HAVE HELD THEM STEADY. SHOWERS
ENTERING THE WRN HALF OF THE CWA DURING THE OVERNIGHT
HOURS. ASSOCIATED WITH H850-700 WAA IN THE EVENING...WHICH THEN
FOCUSES FARTHER S THROUGH THE OVERNIGHT HOURS. THIS SHOULD DIMINISH
THE COVERAGE OF THE SHOWERS AS THEY PUSH E. PTYPE IS TRICKY SINCE IT
WILL BE FALLING AS SNOW...BUT THEN AN ISOTHERMAL LAYER AT 0C LOOKS
TO SETUP FROM 2-6KFT BEFORE NEAR SFC TEMPS BELOW 2KFT WILL BE ABOVE
FREEZING. THIS CREATES A SNOW/RAIN MIX SCENARIO AND SMALL
DIFFERENCES IN THE THERMAL PROFILE WILL DETERMINE PCPN TYPE.
THUS...WENT WITH A RAIN/SNOW MIX OVER UPPER MI...WITH BETTER SNOW
CHANCES TO THE NE HALF.
FRI...MODELS BECOMING MORE CONSISTENT ON THE BULK OF THE PCPN GOING
S OF THE CWA WITH THE SHORTWAVE WEAKENING AS IT TRIES TO PUSH
THROUGH THE UPPER RIDGE AND FOCUSING OF THE BETTER H850-700 WAA
FARTHER SE OVER LK MI AND LOWER MI. THEREFORE...HAVE A DIMINISHING
TREND OVER THE ERN CWA THROUGH THE DAY DUE TO THE PERSISTENT LLVL
DRY AIR FROM THE HUDSON BAY HIGH. SHOULD BE A MIX OF RAIN/SNOW IN
THE MORNING BEFORE DAYTIME HEATING WOULD CHANGE ANY LINGERING PCPN
TO RAIN.
EXTENDED /FRIDAY NIGHT THROUGH TUESDAY/...
HPC FOLLOWED A 00Z GFS/ECMWF ENS MEAN FOR DAYS 5-7...SINCE THERE IS
DECENT CONSISTENCY IN THE TROUGH MOVING OUT OF THE WRN CONUS DURING
THAT TIMEFRAME.
ANOTHER SHORTWAVE MOVES THROUGH THE UPPER GREAT LKS FOR FRI NIGHT
INTO SAT. MOISTURE IS FAIRLY LIMITED...ALONG WITH H850-700 Q-VECTOR
CONV...SO THINK OVERALL PCPN CHANCES WILL BE LIMITED.
UPPER RIDGE BUILDS OVER THE AREA ON SAT NIGHT INTO SUN NIGHT IN
RESPONSE TO UPPER TROUGH OVER THE WRN CONUS SHIFTING INTO THE
PLAINS STATES. DETERMINISTIC RUNS STILL DIFFERING IN THE
INTENSITY/AMPLITUDE OF THIS TROUGH...WITH THE 00Z GFS MUCH DEEPER
AND THE 00Z ECMWF BROADER AND OVER THE CNTRL/NRN PLAINS. 12Z GFS
HAS TRENDED TOWARDS THE 00Z ECMWF AND WILL FOLLOW THE
HPC SOLN AND HAVE THE BROAD SFC LOW OVER THE CNTRL/NRN PLAINS ON SUN
SLIDING SE THROUGH THE UPPER MISS VALLEY AND LOWER GREAT LKS THROUGH
TUES. BEFORE THAT...WARM FRONT LOOKS TO SETUP SOMEWHERE OVER THE
UPPER GREAT LKS OR SRN ONTARIO...WHICH WOULD HAVE A LARGE AFFECT ON
HIGHS. DIFFERENCES IN MODEL SOLNS GIVE UNCERTAINTY IN TEMPS FOR
SUN...AS H850 TEMPS RANGE FROM 7-14C. MAY NOT MIX QUITE THAT
HIGH...BUT MIXING TO H900 WOULD STILL YIELD HIGHS IN THE 60S. SO
HAVE BUMPED UP THE EXISTING FORECAST A FEW DEGREES.
HEADING INTO SUN NIGHT THROUGH TUES...AREA WILL BE ON THE
NRN FRINGES OF THE SFC LOW FEATURES. IF THE LOW TRENDS TOWARDS THE
00Z GFS...WILL LIKELY BE DRY...BUT IF THE 00Z ECMWF AND 12Z GFS ARE
CORRECT WE/LL HAVE BETTER SHOT OF SEEING PCPN. DON/T SEE ANY REASON
TO GO ANYTHING MORE THAN LOW END CHANCES AND WILL KEEP THE PCPN AS
RAIN WITH THE ABUNDANT WARM AIR REMAINING OVER THE AREA.
AS THIS UPPER TROUGH SHIFTS E FOR THE END OF THE WEEK...COULD SEE A
TRANSITION TO A BELOW NORMAL TEMPERATURE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 128 PM EDT TUE MAR 27 2012
THE STRONG WINDS ABOVE THE SFC ARE MIXING DOWN...WITH GUSTS OF 25 TO
35KTS EXPECTED THROUGH TONIGHT. GUST WINDS WILL REMAIN AT CMX...BUT
IT REMAINS UNCERTAIN IF GUSTS NEAR 40KTS WILL BE POSSIBLE OVERNIGHT.
A COLD FRONT MOVING IN FROM THE WEST SHOULD BE EAST OF ALL 3 SITES
BY 05Z...WINDS WILL SLOWLY TURN W...AND THEN NW BY 12Z WEDNESDAY
WITH LAKE ENHANCED SHOWERS POSSIBLE /MAINLY AT CMX/. CIGS WILL DROP
BEHIND THE COLD FRONT...AND MAY NEED TO BE LOWERED AT ALL
SITES...ESPECIALLY AT CMX WHERE THE WIND DIRECTION WILL BE MORE
FAVORABLE FOR LOW CLOUDS. CIGS WILL THEN START TO IMPROVE FROM WEST
TO EAST TOWARD THE END OF THE TAF PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 PM EDT TUE MAR 27 2012
ALTHOUGH THE GOING S GALES OVER THE E HALF OF LK SUP WILL DIMINISH
BY EARLY THIS EVENING AS LO PRES IN MN/WEAKER PRES GRADIENT
ARRIVE...A STRONGER W TO NW WIND WILL REDEVELOP LATER TONIGHT AS THE
LO MOVES TO THE E ACROSS LAKE SUP...WITH MORE GALE FORCE WINDS OVER
MAINLY THE W AND NCENTRAL AT TIMES INTO WED MORNING WHEN THE ARRIVAL
OF COLDER AIR AS WELL WILL RESULT IN ENHANCED MIXING. THE APPROACH
OF A HI PRES RIDGE AND WEAKER PRES GRADIENT WILL RESULT IN
DIMINISHING WINDS BY WED AFTERNOON.
HIGH PRESSURE RIDGE OVER THE AREA ON WED NIGHT WILL LEAD TO
DIMINISHING WINDS AS THEY BACK TO THE NE. EXPECT WINDS TO STAY
BELOW 20KTS FOR MUCH OF THE PERIOD AS A SERIES OF WEAK DISTURBANCES
AND HIGH PRESSURE RIDGES MOVE ACROSS THE AREA THROUGH THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY UNTIL 5 PM EDT /4 PM CDT/ THIS AFTERNOON FOR
MIZ001>006-009.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LSZ267.
GALE WARNING UNTIL 11 AM EDT WEDNESDAY FOR LSZ266.
GALE WARNING FROM 5 AM TO 11 AM EDT WEDNESDAY FOR LSZ244-245-264.
GALE WARNING FROM 11 PM EDT /10 PM CDT/ THIS EVENING TO 5 AM EDT
/4 AM CDT/ WEDNESDAY FOR LSZ241-242-263.
GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR LSZ248>251.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...TITUS
MARINE...KC/SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
114 PM EDT TUE MAR 27 2012
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY EVENING)
ISSUED AT 1139 AM EDT TUE MAR 27 2012
THUNDERSTORM POTENTIAL THE MAIN WEATHER STORY...
LIKE GFS AND HRRR TREND OF ISOLATED STORMS WEST INCREASING TO
SCATTERED AS THE AREA MOVES EAST. DEVELOPMENT WILL BE ASSOCIATED WITH
NARROW RIBBON OF DEEP MOISTURE ASSOCIATED WITH 50-60KT LOW LEVEL
JET ALONG AND JUST AHEAD OF COLD FRONT. EXPECT TO SEE RAPID
INCREASE IN MOISTURE AND MUCAPE AFTER 21Z WITH FRONTAL PASSAGE BY
03Z ALONG THE COAST AND 09Z FOR THE EAST COUNTIES.
SPC HAS US IN GENERAL THUNDER WITH A FIVE PERCENT CHANCE OF SEVERE
STORMS. STRONG LOW LEVEL WIND FIELDS AND RESULTING SHEAR SUPPORT
DAMAGING WINDS AS THE MAIN SEVERE THREAT. ANY GOOD LOW-TOP SHOWERS
WILL ALSO BE CAPABLE OF PRODUCING LOCAL 40 KT WIND GUSTS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 411 AM EDT TUE MAR 27 2012
CANADIAN SFC RIDGING WILL BRING A FROST THREAT THURSDAY AND FRIDAY
MORNINGS. OVERRUNING PRECIP POSSIBLE FOR FRIDAY INTO SATURDAY. 00Z
GFS AND ECMWF HAVE TRENDED SOUTH WITH THE SFC LOW AND WOULD KEEP
LOWER MICHIGAN COOLER AND MORE STABLE SO KEPT MENTION OF THUNDER OUT
OF THE FORECAST.
PATTERN BECOMES MORE AMPLIFIED EARLY NEXT WEEK WITH SIGNIFICANT LOW
APPROACHING. LOW CONFIDENCE ON TIMING BUT STRONG BAROCLINIC ZONE
PRECEDES THE LOW WHICH COULD FOCUS SOME CONVECTION BEGINNING MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 108 PM EDT TUE MAR 27 2012
ISOLATED THUNDERSTORM THREAT THIS EVENING ASSOCIATED WITH PASSING
COLD FRONT. EXPECT COVERAGE OF SHOWER ACTIVITY TO INCREASE AS THE
FRONT PUSHES FROM WEST TO EAST WITH BEST THREAT
KBTL...KLAN...KJXN. LOCAL WIND GUSTS TO 45KTS POSSIBLE WITH
SHOWERS AND THUNDERSTORMS.
LOCAL SURFACE WIND GUSTS TO 30 KTS POSSIBLE THROUGH THIS EVENING.
THERE WILL ALSO BE A CORE OF 50 KT WINDS ABOVE 2,500 FT THROUGH
LATE EVENING.
OUTLOOK...MVFR CIG KGRR TO KLAN ASSOCIATED WITH COLD AIR
ALOFT...TOPS 5,000 FT. ISOLATED SFC WIND GUSTS 30 KTS WITH LGT/MDT
CHOP FROM SURFACE TO 5,000 FT ABOVE GROUND IN WEST-NORTHWEST WINDS.
&&
.MARINE...
ISSUED AT 1139 AM EDT TUE MAR 27 2012
CONFIDENCE OF GALE FORCE WINDS IS DOWN A BIT AND DROPPED TO SCA
FOR THREE SOUTHERN COASTAL ZONES. STILL EXPECT MARGINAL SOUTH GALES
NEAR TIME COLD FRONTAL PASSAGE EARLY THIS EVENING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WARNING UNTIL 8 AM EDT WEDNESDAY FOR LMZ847>849.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR LMZ844>846.
&&
$$
SYNOPSIS...COBB
SHORT TERM...COBB
LONG TERM....OSTUNO
AVIATION...COBB
MARINE...COBB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1204 PM EDT TUE MAR 27 2012
.SYNOPSIS...
ISSUED AT 1139 AM EDT TUE MAR 27 2012
A WARMING AFTERNOON WITH SCATTERED SHOWERS AND POSSIBLY A
THUNDERSTORM EXPECTED OVER THE AREA THIS EVENING. THE SHOWERS
ARE ASSOCIATED WITH AN APPROACHING COLD FRONT THAT WILL SWEEP
THROUGH THE STATE FROM WEST TO EAST OVERNIGHT. SEASONABLY COOL
WEATHER WILL RETURN LATE ON WEDNESDAY AND THURSDAY WITH ANOTHER
THREAT OF RAIN ON FRIDAY.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY EVENING)
ISSUED AT 1139 AM EDT TUE MAR 27 2012
THUNDERSTORM POTENTIAL THE MAIN WEATHER STORY...
LIKE GFS AND HRRR TREND OF ISOLATED STORMS WEST INCREASING TO
SCATTERED AS THE AREA MOVES EAST. DEVELOPMENT WILL BE ASSOCIATED WITH
NARROW RIBBON OF DEEP MOISTURE ASSOCIATED WITH 50-60KT LOW LEVEL
JET ALONG AND JUST AHEAD OF COLD FRONT. EXPECT TO SEE RAPID
INCREASE IN MOISTURE AND MUCAPE AFTER 21Z WITH FRONTAL PASSAGE BY
03Z ALONG THE COAST AND 09Z FOR THE EAST COUNTIES.
SPC HAS US IN GENERAL THUNDER WITH A FIVE PERCENT CHANCE OF SEVERE
STORMS. STRONG LOW LEVEL WIND FIELDS AND RESULTING SHEAR SUPPORT
DAMAGING WINDS AS THE MAIN SEVERE THREAT. ANY GOOD LOW-TOP SHOWERS
WILL ALSO BE CAPABLE OF PRODUCING LOCAL 40 KT WIND GUSTS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 411 AM EDT TUE MAR 27 2012
CANADIAN SFC RIDGING WILL BRING A FROST THREAT THURSDAY AND FRIDAY
MORNINGS. OVERRUNING PRECIP POSSIBLE FOR FRIDAY INTO SATURDAY. 00Z
GFS AND ECMWF HAVE TRENDED SOUTH WITH THE SFC LOW AND WOULD KEEP
LOWER MICHIGAN COOLER AND MORE STABLE SO KEPT MENTION OF THUNDER OUT
OF THE FORECAST.
PATTERN BECOMES MORE AMPLIFIED EARLY NEXT WEEK WITH SIGNIFICANT LOW
APPROACHING. LOW CONFIDENCE ON TIMING BUT STRONG BAROCLINIC ZONE
PRECEDES THE LOW WHICH COULD FOCUS SOME CONVECTION BEGINNING MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1139 AM EDT TUE MAR 27 2012
ISOLATED THUNDERSTORM THREAT THIS EVENING ASSOCIATED WITH PASSING
COLD FRONT. EXPECT COVERAGE OF SHOWER ACTIVITY TO INCREASE AS THE
FRONT PUSHES FROM WEST TO EAST WITH BEST THREAT
KBTL...KLAN...KJXN. LOCAL WIND GUSTS TO 45KTS POSSIBLE WITH
SHOWERS AND THUNDERSTORMS.
LOCAL SURFACE WIND GUSTS TO 30 KTS POSSIBLE THROUGH THIS EVENING.
THERE WILL ALSO BE A CORE OF 50 KT WINDS ABOVE 2,500 FT THIS
EVENING.
&&
.MARINE...
ISSUED AT 1139 AM EDT TUE MAR 27 2012
CONFIDENCE OF GALE FORCE WINDS IS DOWN A BIT AND DROPPED TO SCA
FOR THREE SOUTHERN COASTAL ZONES. STILL EXPECT MARGINAL SOUTH GALES
NEAR TIME COLD FRONTAL PASSAGE EARLY THIS EVENING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WARNING UNTIL 8 AM EDT WEDNESDAY FOR LMZ847>849.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR LMZ844>846.
&&
$$
SYNOPSIS...COBB
SHORT TERM...COBB
LONG TERM....OSTUNO
AVIATION...COBB
MARINE...COBB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
741 AM EDT TUE MAR 27 2012
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 411 AM EDT TUE MAR 27 2012
FORECAST CONCERNS DEAL WITH THE CONVECTIVE POTENTIAL LATER
TODAY/TONIGHT.
KGRR-88D SHOWS SOME LIGHT PCPN TRYING TO WORK INTO LOWER MICHIGAN.
THIS PCPN WAS BEING CAUSED BY ISENTROPIC LIFT AHEAD OF THE SFC LOW
THAT/S STILL OVER THE NRN PLAINS. 00Z SOUNDINGS REVEAL VERY DRY
LOW LEVEL AIR AND SO MUCH IF NOT ALL OF THIS PCPN SHOULD FALL AS
VIRGA OVER THE CWA. I BELIEVE THAT MUCH OF TODAY WILL BE DRY. THE
LATEST HRRR ALSO SUPPORTS THIS. THE EXCEPTION MAY BE THE NRN CWA WHERE
PCPN CHANCES ARE A BIT HIGHER.
WE COULD SEE SOME STORMS TONIGHT. AND THERE ARE DYNAMICS AVAILABLE
THAT COULD RESULT IN SOME OF THE STORMS BEING STRONG TO SEVERE.
AHEAD OF THE COLD FRONT...SOME ELEVATED INSTABILITY IS PROGD TO
DEVELOP OVER THE WRN CWA LATE THIS AFTERNOON AND EVENING. ELEVATED
LI/S FALL TO AROUND -2C. A STRONG 55KT LLJ IS SHOWN IN SEVERAL OF
THE SHORT RANGE MODELS. ADDITIONALLY...55-60 KTS OF SHEAR IS
AVAILABLE. SO IF SOME STORMS DEVELOP THEY/LL HAVE THE POTENTIAL TO
ORGANIZE. GUSTY WINDS WILL BE THE MAIN THREAT. A SLIGHT RISK FOR
SVR STORMS EXISTS JUST SOUTH OF MICHIGAN WHERE SFC HEATING WILL BE
STRONGER AND WE/LL NEED TO WATCH FOR A FEW OF THOSE STORMS MOVING
NORTH TOWARD THE CWA.
FROPA LOOKS LIKE IT WILL COME AROUND 06Z GIVE OR TAKE A COUPLE OF
HOURS. PCPN CHANCES WILL RAPIDLY FALL BEHIND THE FRONT AND
WEDNESDAY WILL BE ROUGHLY 10 DEGREES COOLER THAN TODAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 411 AM EDT TUE MAR 27 2012
CANADIAN SFC RIDGING WILL BRING A FROST THREAT THURSDAY AND FRIDAY
MORNINGS. OVERRUNING PRECIP POSSIBLE FOR FRIDAY INTO SATURDAY. 00Z
GFS AND ECMWF HAVE TRENDED SOUTH WITH THE SFC LOW AND WOULD KEEP
LOWER MICHIGAN COOLER AND MORE STABLE SO KEPT MENTION OF THUNDER OUT
OF THE FORECAST.
PATTERN BECOMES MORE AMPLIFIED EARLY NEXT WEEK WITH SIGNIFICANT LOW
APPROACHING. LOW CONFIDENCE ON TIMING BUT STRONG BAROCLINIC ZONE
PRECEDES THE LOW WHICH COULD FOCUS SOME CONVECTION BEGINNING MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 740 AM EDT TUE MAR 27 2012 WINDS WILL BE PICKING UP THIS
MORNING WITH GUSTS OVER 25 KNOTS AT TIMES THROUGH THE AFTERNOON
AND EVENING. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE BY
LATE AFTERNOON...MOSTLY FROM MKG TO AZO. LEFT THUNDER OUT OF THE
FORECAST FOR LAN AND JXN AS CHANCES WILL BE LESS THERE.
&&
.MARINE...
ISSUED AT 411 AM EDT TUE MAR 27 2012
A GALE WARNING REMAINS IN EFFECT THROUGH TONIGHT. STRONG SLY WINDS
WILL DEVELOP TODAY AND CONTINUE INTO THE EVENING PRIOR TO FROPA.
WINDS WILL BEGIN TO DIMINISH AFTER 06Z. A SCA WILL LIKELY BE
NEEDED WEDNESDAY AS WAVES WILL REMAIN HIGH.
&&
.HYDROLOGY...
ISSUED AT 411 AM EDT TUE MAR 27 2012
HYDRO ISSUES ARE MIMIMAL TODAY. A TOUR THROUGH THE HYDROGRAPHS
SHOWS RIVERS STEADY TO SLOWLY FALLING. THIS TREND WILL CONTINUE
TODAY. SCATTERED THUNDERSTORMS ARE POSSIBLE TONIGHT BUT WIDESPREAD
HEAVY RAINFALL IS NOT EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR MIZ037>040-
043>046-050>052-056>059-064>067-071>074.
LM...GALE WARNING UNTIL 8 AM EDT WEDNESDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...93
SHORT TERM...93
LONG TERM....OSTUNO
AVIATION...OSTUNO
MARINE...93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
413 AM EDT TUE MAR 27 2012
.SYNOPSIS...
ISSUED AT 411 AM EDT TUE MAR 27 2012
A COLD FRONT MOVING TOWARD THE GREAT LAKES WILL INCREASE THE
CHANCES OF SHOWERS AND THUNDERSTORMS LATE TODAY AND TONIGHT. SOME
OF THE STORMS COULD PRODUCE GUSTY WINDS. AFTER A WARM UP CLOSE TO
60 TODAY...WE/LL BE BACK NEAR 50 WEDNESDAY. MORE SHOWERS AND
THUNDERSTORMS ARE POSSIBLE TOWARD THE WEEKEND AS ANOTHER LOW
PRESSURE SYSTEM MOVES TOWARD THE GREAT LAKES.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 411 AM EDT TUE MAR 27 2012
FORECAST CONCERNS DEAL WITH THE CONVECTIVE POTENTIAL LATER
TODAY/TONIGHT.
KGRR-88D SHOWS SOME LIGHT PCPN TRYING TO WORK INTO LOWER MICHIGAN.
THIS PCPN WAS BEING CAUSED BY ISENTROPIC LIFT AHEAD OF THE SFC LOW
THAT/S STILL OVER THE NRN PLAINS. 00Z SOUNDINGS REVEAL VERY DRY
LOW LEVEL AIR AND SO MUCH IF NOT ALL OF THIS PCPN SHOULD FALL AS
VIRGA OVER THE CWA. I BELIEVE THAT MUCH OF TODAY WILL BE DRY. THE
LATEST HRRR ALSO SUPPORTS THIS. THE EXCEPTION MAY BE THE NRN CWA WHERE
PCPN CHANCES ARE A BIT HIGHER.
WE COULD SEE SOME STORMS TONIGHT. AND THERE ARE DYNAMICS AVAILABLE
THAT COULD RESULT IN SOME OF THE STORMS BEING STRONG TO SEVERE.
AHEAD OF THE COLD FRONT...SOME ELEVATED INSTABILITY IS PROGD TO
DEVELOP OVER THE WRN CWA LATE THIS AFTERNOON AND EVENING. ELEVATED
LI/S FALL TO AROUND -2C. A STRONG 55KT LLJ IS SHOWN IN SEVERAL OF
THE SHORT RANGE MODELS. ADDITIONALLY...55-60 KTS OF SHEAR IS
AVAILABLE. SO IF SOME STORMS DEVELOP THEY/LL HAVE THE POTENTIAL TO
ORGANIZE. GUSTY WINDS WILL BE THE MAIN THREAT. A SLIGHT RISK FOR
SVR STORMS EXISTS JUST SOUTH OF MICHIGAN WHERE SFC HEATING WILL BE
STRONGER AND WE/LL NEED TO WATCH FOR A FEW OF THOSE STORMS MOVING
NORTH TOWARD THE CWA.
FROPA LOOKS LIKE IT WILL COME AROUND 06Z GIVE OR TAKE A COUPLE OF
HOURS. PCPN CHANCES WILL RAPIDLY FALL BEHIND THE FRONT AND
WEDNESDAY WILL BE ROUGHLY 10 DEGREES COOLER THAN TODAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 411 AM EDT TUE MAR 27 2012
CANADIAN SFC RIDGING WILL BRING A FROST THREAT THURSDAY AND FRIDAY
MORNINGS. OVERRUNING PRECIP POSSIBLE FOR FRIDAY INTO SATURDAY. 00Z
GFS AND ECMWF HAVE TRENDED SOUTH WITH THE SFC LOW AND WOULD KEEP
LOWER MICHIGAN COOLER AND MORE STABLE SO KEPT MENTION OF THUNDER OUT
OF THE FORECAST.
PATTERN BECOMES MORE AMPLIFIED EARLY NEXT WEEK WITH SIGNIFICANT LOW
APPROACHING. LOW CONFIDENCE ON TIMING BUT STRONG BAROCLINIC ZONE
PRECEDES THE LOW WHICH COULD FOCUS SOME CONVECTION BEGINNING MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 135 AM EDT TUE MAR 27 2012
AN APPROACHING COLD FRONT WILL PUSH HIGH CLOUDS OVER THE REGION
TONIGHT. IT/S POSSIBLE KMKG COULD SEE A BRIEF SHOWER FROM 08-12Z
BUT MORE LIKELY THE PCPN WILL BE VIRGA. TSRA POSSIBLE AFTER 00Z
BUT CONFIDENCE NOT HIGH ENOUGH TO HAVE A PREDOMINATE GROUP.
&&
.MARINE...
ISSUED AT 411 AM EDT TUE MAR 27 2012
A GALE WARNING REMAINS IN EFFECT THROUGH TONIGHT. STRONG SLY WINDS
WILL DEVELOP TODAY AND CONTINUE INTO THE EVENING PRIOR TO FROPA.
WINDS WILL BEGIN TO DIMINISH AFTER 06Z. A SCA WILL LIKELY BE
NEEDED WEDNESDAY AS WAVES WILL REMAIN HIGH.
&&
.HYDROLOGY...
ISSUED AT 411 AM EDT TUE MAR 27 2012
HYDRO ISSUES ARE MIMIMAL TODAY. A TOUR THROUGH THE HYDROGRAPHS
SHOWS RIVERS STEADY TO SLOWLY FALLING. THIS TREND WILL CONTINUE
TODAY. SCATTERED THUNDERSTORMS ARE POSSIBLE TONIGHT BUT WIDESPREAD
HEAVY RAINFALL IS NOT EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR MIZ037>040-
043>046-050>052-056>059-064>067-071>074.
LM...GALE WARNING FROM 8 AM THIS MORNING TO 8 AM EDT WEDNESDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...93
SHORT TERM...93
LONG TERM....OSTUNO
AVIATION...93
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1221 AM EDT TUE MAR 27 2012
.UPDATE...
ISSUED AT 1114 PM EDT MON MAR 26 2012
WAA PCPN WAS OVER NE MN AND NW WI WAS EXPANDING IN COVERAGE AND
MOVING STEADILY TO THE NORTHEAST. ONLY MINOR ADJUSTMENTS WERE MADE
TO TIMING OF PCPN WITH A SLIGHTLY LATER ARRIVAL DUE TO THE TIME TO
SATURATE THE VERY DRY LOW LEVELS. TEMPS OVER THE WEST NEAR IRONWOOD
AND WAKEFIELD SHOULD REMAIN ABOVE FREEZING WITH MAINLY RAIN
WHILE TO THE EAST NEAR WATERSMEET AND BRUCE CROSSING...TEMPS (AIDED
BY EVAPORATIVE COOLING) MAY STILL DROP TO AROUND FREEZING. SO...LEFT
THE FZRA ADVY IN PLACE BUT EMPHASIZED FZRA HAZARD ONLY OVER THE ERN
PORTIONS OF GOGEBIC AND ONTONAGON COUNTIES.
&&
.SYNOPSIS...
ISSUED AT 417 PM EDT MON MAR 26 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPRAWLING UPR RDG
OVER CNTRL NAMERICA BTWN TROFS OVER QUEBEC/NEW ENGLAND AND ANOTHER
OFF THE W COAST. HUDSON BAY HI PRES UNDER THE CONFLUENT NW FLOW ALF
BTWN THE RDG AND ERN TROF AS WELL AS VERY DRY AIRMASS DEPICTED ON
THE 12Z INL AND GRB RAOBS /12Z H85 DEWPT DEPRESSION WAS 43C AT INL/
ARE BRINGING A TRANQUIL BUT MORE SEASONABLY CHILLY DAY TO UPR MI.
BUT MORE CLDS WELL IN ADVANCE OF SHARP WARM FNT ATTENDANT TO DVLPG
LO PRES IN THE NW HI PLAINS ARE SPREADING FM MN/NW WI TOWARD IWD.
THIS SFC LO IS ASSOCIATED WITH VIGOROUS NEGATIVELY TILTED SHRTWV
LIFTING NEWD OUT OF THE DESERT SW. THE WARM FNT SEPARATES VERY WARM
AIRMASS IN THE SRN PLAINS WITH 12Z H85 TEMP AS HI AS 20C AT DODGE
CITY KS FM CHILLY AIRMASS IN THE GRT LKS/H85 TEMPS OF -8C AT YPL AND
APX. SOME -SHRASN ARE FALLING OVER PARTS OF MN/NW WI UNDER THE
THICKER CLDS/ SHARPER H85-7 FGEN AS 12Z MPX RAOB SHOWS A SATURATED
LYR FM H85-5. THERE HAVE BEEN A FEW LTG STRIKES UNDER THIS BAND OF
SHRA TODAY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 417 PM EDT MON MAR 26 2012
MAIN FCST CONCERNS TNGT INTO TUE ARE MIXED PCPN/ICING POTENTIAL/
GOING FZRA ADVY ASSOCIATED WITH APRCHG WARM FNT...THEN SHRA CHCS ON
TUE WITH ARRIVAL OF DRY SLOT.
TNGT...AS HI PRES/COLD DRY AIRMASS IN ONTARIO THIS AFTN RETREAT INTO
QUEBEC AND SHRTWV IN THE DESERT SW SHIFTS NEWD INTO THE NRN PLAINS
TNGT IN RATHER PROGRESSIVE UPR FLOW...ATTENDANT WARM FNT/CLD BAND TO
THE SW WL CLOSE IN ON UPR MI. THE COMBINATION OF VIGOROUS ISENTROPIC
ASCENT/MID LVL MOISTENING ACCOMPANYING STRENGTHENING SSW FLOW/H925
WINDS INCRSG TO 50KTS...INCRSG H4-2 DVGC...AND H85-7 FGEN WL ALLOW
FOR PCPN TO BREAK OUT W-E TOWARD ERY ARND 12Z DESPITE LINGERING LLVL
DRY AIR. SINCE THE MID LVLS MOISTEN AND DYNAMICS ARRIVE BEFORE THE
LLVLS WARM/MOISTEN...FCST SDNGS INDICATE A GOOD POTENTIAL FOR
FZRA/SLEET WITH WBLB TEMPS AS LO AS -5C TO -7C IN THE SUB H85 LYR
UNDER THE FGEN PCPN BAND. USED A NON DIURNAL TOOL FOR TEMPS WITH MIN
READINGS RELATIVELY EARLY...THEN TEMPS RISING LATER WITH INCRSG
WIND/WAD. EVAPORATE COOLING NEAR THE SFC WL TEND TO SLOW THE RISE IN
AREAS EXPERIENCING PCPN. INCLUDED MENTION OF TS W OF THE AXIS OF MAX
FGEN WITH H8-5 LAPSE RATES NEAR MOIST ADIABATIC ENHANCED BY THE
WAD/VIGOROUS DYNAMICS.
TUE...SHRTWV/OCCLUDED LO ARE FCST TO MOVE TO JUST NW OF THUNDER BAY
ONTARIO BY 00Z WED...WITH ACCOMPANYING DRY SLOT ON ITS SE FLANK
IMPACTING THE CWA. AFT AREA OF DEEPER MSTR/WAD/H85-7 FGEN/H4-2 DVGC
EXIT THE E BY 18Z...ANY LINGERING PCPN SHOULD BE NOTHING MORE THAN
ISOLD/SCT -SHRA AS FCST SDNGS SHOW QUITE A BIT OF MID LVL DRYING/
CAPPING DVLPG AFT THE EXIT OF THE DEEPER MSTR/DYNAMICS. GUSTY WINDS
WL DVLP WITH LLVL WARMING/DESTABILIZATION MIXING OUT THE HIER
MOMENTUM ABV INITIAL SHARP INVRN. BEST CHC FOR CLRG WL BE OVER THE
FAR W FM IWD-ONTONAGON WITH DOWNSLOPING S WIND. MIXING TO H85 ON
NAM/GFS FCST SDNGS INDICATE MAX TEMPS MAY REACH 60 IN THIS AREA.
LOCATIONS DOWNWIND OF LK MI WL BE MUCH COOLER WITH FLOW OFF CHILLY
WATERS MAINTAINING HIER STABILITY/TEMPS TOWARD THE LOWER END OF
GUIDANCE.
AS FOR HEADLINES...SUSPECT MODEL QPF THAT WOULD INDICATE NEED FOR AN
ICE STORM WARNING IS A BIT TOO HI CONSIDERING THE STEADY EWD
MOVEMENT FCST OF THE FGEN/UPR DVGC CORE AND LINGERING LLVL DRY
AIR...SO ADVY SHOULD COVER THE FRZG PCPN POTENTIAL WITH ANY ICE
ACCUMULATION NOT LIKELY TO EXCEED ABOUT 0.10 INCH. RECENT WARM SOILS
ALSO WL TEND TO LIMIT ICE ACCUM POTENTIAL. TWEAKED THE TIMING OF THE
HEADLINE A BIT TO ACCOUNT FOR SLOWER ARRIVAL OF PCPN INTO THE
CENTRAL COUNTIES. ALSO EXPANDED THE FZRA HEADLINE TO THE E EXCEPT
FOR MNM COUNTY...WHICH WL BE FARTHEST S OF THE SHARPER DYNAMICS AND
PROBABLY SEE LESS PCPN/ICING.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 417 PM EDT MON MAR 26 2012
995MB LOW LOCATED OVER THE ARROWHEAD OF MN AT 00Z AND
WILL SLIDE E ACROSS LK SUPERIOR ON TUES NIGHT. BULK OF INITIAL PCPN
WILL HAVE EXITED THE CWA AT THE START OF THE LONG TERM PERIOD. MAIN
AREA OF PCPN THROUGH THE NIGHT WILL BE LOCATED ALONG THE WARM FRONT
OVER NE LK SUPERIOR...BUT WRAP AROUND SHOWERS WILL AFFECT THE NRN
HALF OF UPPER MI THROUGH A GOOD PORTION OF THE NIGHT. EXPECT THE
PCPN TO FALL AS RAIN...DUE TO THE LOW LLVL WARM AIR SURGING N
THROUGH THE NIGHT AHEAD OF THE COLD FRONT. AS COLD AIR ARRIVES OVER
THE WEST COULD SEE THE RAIN MIXING WITH SNOW OVER THE FAR WEST NEAR
DAYBREAK. WITH THE LLVL WARM AIR AHEAD OF THE FRONT...FOLLOWED A
NON-DIURNAL TEMP CURVE ON TUES NIGHT. TEMPS WILL BE WARMER OVER
PORTIONS OF THE CENTRAL/ERN CWA TUESDAY NIGHT THAN DURING THE DAY
TUESDAY...VALUES REACHING THE MID-UPPER 40S.
COLD FRONT WILL SLIDE THROUGH THE AREA ON WED MORNING AND LEAD TO
FALLING H850 TEMPS AND WINDS SHIFTING TO THE NNW. WITH H850 TEMPS
FALLING FROM 1-2C AT 12Z WED TO -4 TO -6C BY 00Z THURS SHOULD SEE
LK ENHANCED SHOWERS THROUGH A GOOD PORTION OF THE DAY...ESPECIALLY
WITH THE DEEPER MOISTURE PRESENT DURING THE MORNING HOURS. HAVE
PEAKED THE POPS OVER THE WEST DURING THAT TIME FRAME...THEN
DIMINISHED THROUGH THE DAY AS DRY AIR STARTS TO ERRODE THE PCPN
FROM THE NW.
PCPN TYPE IS THE MAIN CONCERN FOR WED. NAM SHOWING CLOUD TOP IS
AROUND -8 TO -10C SO PCPN START AS SNOW IN THE CLOUDS...BUT GFS IS
WARMER WITH CLOUD TOP TEMPS AROUND -5C AND MAINLY RAIN. HAVE
FOLLOWED A LITTLE COOLER TEMPERATURES AND A THE PCPN STARTING AT
SNOW. THE LLVL WARM LAYER WILL BE THE MAIN PCPN TYPE FACTOR...AS
IT WILL TRY TO MELT THE PCPN BEFORE IT HITS THE SFC. USED A
COMBINATION OF SFC TEMPS AND WETBULB ZERO HEIGHTS FOR RAIN/SNOW
POTENTIAL ON WED...WITH THE HIGHER TERRAIN SEEING THE SNOW
FIRST AND THEN SPREADING ACROSS THE AREA FROM N TO S THROUGH
THE AFTN AND EARLY EVENING BUT OVERALL PCPN SHOULD BE DIMINISHING
THEN. NON DIURNAL TEMP CURVE AGAIN ON WED...HIGHS IN THE MORNING
AND EARLY AFTN THEN FALLING.
LK ENHANCED SHOWERS WILL BE DIMINISHING FROM W TO E IN THE
AFTN/EVENING...AS DRIER AIR AND ANTICYCLONIC FLOW ARRIVE WITH THE
HIGH PRESSURE RIDGE. BUT H900 MOISTURE ONCE AGAIN LOOKS TO LINGER
OVER THE AREA WED NIGHT INTO THURS MORNING. WITH H900 TEMPS AROUND
-6.5C...SHOULD SEE SUFFICIENT LK INSTABILITY TO KEEP CLOUDS GOING
AS WINDS VEER TO THE NE ON WED NIGHT INTO THURS MORNING. WILL TRY
TO HOLD ONTO THE CLOUDS LONGER THAN THE MODELS ARE SHOWING...AS
THEY HAD A DIFFICULT TIME WITH THE SIMILAR FEATURE YESTERDAY. ONCE
THE LLVL MOISTURE DEPARTS OR IS MIXED OUT THURS MORNING...LOOKS TO
BE A NICE DAY ON THURS WITH THE AREA UNDER THE HIGH PRESSURE RIDGE.
COULD SEE THURS BEING VERY SIMILAR TO TODAY...WITH HUDSON BAY HIGH
PRESSURE RIDGE OVER THE AREA AND TRYING TO PULL DRIER AIR INTO THE
ERN CWA. WILL LOWER DEWPOINT VALUES 5-7 DEGREES FROM THE GOING
MID 20S OVER THE EAST...AS MODEL MIXED TD VALUES INDICATE SINGLE
DIGIT VALUES. MAY NEED TO DROP FURTHER IF TREND CONTINUES.
EXTENDED /THURSDAY NIGHT THROUGH MONDAY/...
SHORTWAVE APPROACHES THE AREA ON FRI...TRYING TO PUSH THROUGH THE
UPPER RIDGE. 00-12Z GEM/GFS/ECMWF DIFFERING ON THE THIS SHORTWAVE
AND ASSOCIATED SFC FEATURES...SO HAVE CHANCES MOVING INTO THE WRN
CWA IN THE MORNING AND THEN EXPECT A DIMINISHING TREND AS THE
SHORTWAVE WEAKENS WHILE HEADING E IN THE AFTN.
WEAK UPPER AND SFC RIDGING PUSHES IN FOR FRI NIGHT AND SHOULD LEAD
TO A DRY PERIOD...BEFORE NEXT WAVE APPROACHES FOR THE WEEKEND.
00-12Z ECMWF/GEM/GFS/UKMET RUNS VARY CONSIDERABLY WITH THIS
WAVE...IN TIMING/LOCATION/STRENGTH. CONSENSUS IDEA IS THAT IT WILL
PUSH ALONG THE US/CANADA BORDER IN THE NRN PLAINS ON FRI
NIGHT...THEN SLIDE JUST N OF LK SUPERIOR ON SAT. THIS SHOULD KEEP
MUCH OF THE PCPN TO THE N OF THE AREA...BUT THE GEM IS THE FARTHEST
S AND STRONGER WITH THE LOW CENTER AND PUSHES IT ACROSS THE CWA.
THIS WAVE WILL SLIDE E ON SAT NIGHT...LEADING TO WEAK RIDGING AGAIN
ON SUN AND SUN NIGHT BEFORE NEXT WAVE SLIDES IN ON MON. OUT OF THE
THREE WAVES IN THE EXTENDED...THE MONDAY FEATURE LOOKS TO BE THE
MOST POTENT AND AFFECTING MUCH OF THE NCNTRL U.S. WILL MENTION
CHANCES ON MON TO ACCOUNT FOR THIS.
EXTENDED PERIOD LOOKS TO SEE ABOVE NORMAL TEMPERATURES...WITH
GRADUAL WARMING HEADING THROUGH THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1215 AM EDT TUE MAR 27 2012
MID CLDS AND SOME MIXED PCPN IN ADVANCE OF A WARM FRONT WILL ARRIVE
TONIGHT...BUT LINGERING LOW LEVEL DRY AIR WILL LIMIT THE POTENTIAL
FOR LOWER CIG/VSBY INTO THE MVFR RANGE. AS THE PCPN MOVES IN WHILE
SURFACE TEMPS AREREMAIN JUST BELOW FREEZING AND LOW LEVEL DRY AIR
LINGERS EXPECT SOME -FZRA...ESPECIALLY AT SAW WHERE UPSLOPE SSE WIND
WILL MAINTAIN LOWER TEMPS LONGER. WITH A STRONG LOW LEVEL S WIND
AHEAD OF THE APPROACHING WARM FRONT...LLWS IS LIKELY TO IMPACT ALL 3
TAF SITES. THESE WINDS ARE LIKELY TO MIX TO THE SFC ON TUE FOLLOWING
SOME LLVL WARMING/DESTABILIZATION. AS WINDS VEER WRLY BEHIND A COLD
FRONT TUE EVENING AND PRES RISE MOVES THROUGH...STRONG WINDS ARE
EXPECTED AT CMX GUSTING TO NEAR 40KT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 PM EDT MON MAR 26 2012
AS THE PRESSURE GRADIENT STRENGTHENS OVER THE UPPER GREAT LAKES
BETWEEN A DEEPENING LO PRES SYSTEM MOVING E FROM THE NORTHERN PLAINS
AND RETREATING HI PRES IN SE CANADA...EXPECT INCREASING SSE WINDS TO
REACH GALE FORCE AND UP TO 40 KTS ON TUE OVER THE E HALF OF LAKE
SUPERIOR FAVORED FOR STRONGER S WINDS DESPITE HI STABILITY OVER THE
RELATIVELY CHILLY LAKE WATERS.
AS THE LOW MOVES ACROSS LAKE SUPERIOR ON TUES NIGHT AND EXITS TO
THE E ON WED...WIND WILL SHIFT TO THE NW AND GUST TO 30KTS TUES
NIGHT. MARINE LAYER WILL LIKELY KEEP THE HIGHER WINDS ALOFT
FROM REACHING THE SFC...SO DON/T THINK WE WILL SEE ANY GALES. HIGH
PRESSURE RIDGE BUILDING IN WED AFTN AND NIGHT WILL DIMINISH THE
WINDS BELOW 20KTS WITH WINDS GRADUALLY VEERING THROUGH THURS. A WEAK
DISTURBANCE WILL PUSH ACROSS THE AREA ON FRI...BUT THE ESE WINDS
SHOULD STAY BELOW 20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FREEZING RAIN ADVISORY UNTIL 11 AM EDT /10 AM CDT/ THIS MORNING
FOR MIZ004-005-010-011-084.
FREEZING RAIN ADVISORY FROM 5 AM EARLY THIS MORNING TO NOON EDT
TODAY FOR MIZ006-007-013-014-085.
FREEZING RAIN ADVISORY UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING
FOR MIZ002-009.
LAKE SUPERIOR...
GALE WARNING FROM 10 AM THIS MORNING TO 7 PM EDT THIS EVENING
FOR LSZ267.
GALE WARNING FROM 7 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR
LSZ266.
GALE WARNING FROM 8 AM THIS MORNING TO 6 PM EDT THIS EVENING FOR
LSZ244-245-248-249-264-265.
GALE WARNING FROM 10 AM THIS MORNING TO 6 PM EDT THIS EVENING
FOR LSZ250-251.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...JLB
MARINE...KC/SRF
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
956 PM CDT WED MAR 28 2012
.UPDATE...
ISSUED AT 933 PM CDT WED MAR 28 2012
ISOLATED SHOWERS AND STORMS CONTINUE TO DEVELOP ALONG FRONTAL
BOUNDARY WHICH EXTENDS FROM JUST S OF MCI SE THROUGH FAM. MORE
ORGANIZED CONVECTION WAS ACROSS ERN KS INTO W CNTRL MO JUST E OF
A SLY LOW LEVEL JET AXIS AND JUST AHEAD OF A WEAK SHORTWAVE OVER
SRN NEBRASKA AND NRN KANSAS. THIS ACTIVITY SHOULD SHIFT EWD TGT
WITH THE STRONGER STORMS IMPACTING CNTRL MO...AND WEAKER SHOWERS
AND STORMS FURTHER N MOVING EWD INTO NERN MO. AS THIS ACTIVITY
SPREADS EWD LATE TGT IT SHOULD WEAKEN AS IT GETS INTO ERN MO AND
ENCOUNTERS LESS LOW LEVEL MOISTURE AND INSTABILITY. WILL CONTINUE
WITH THE HIGHEST POPS OVER CNTRL MO INTO SERN MO NEAR THE
FRONT...WITH LITTLE IF ANY POPS OVER THE IL COUNTIES OF OUR
FORECAST AREA WITH A SFC RIDGE EXTENDING SWD THROUGH WI AND IL.
GKS
&&
.SHORT TERM...
ISSUED AT 320 PM CDT WED MAR 28 2012
(TONIGHT THROUGH FRIDAY)
PRIMARY CONCERN IN THE SHORT TERM IS POPS TONIGHT THROUGH FRIDAY.
QUASI-STATIONARY FRONT EXTENDS FROM NEAR FARMINGTON WEST-NORTHWEST
BETWEEN COLUMBIA AND SEDALIA TO NEAR TOPEKA. UNSTABLE AIRMASS IS
EVIDENT IN CUMULUS FIELD SOUTH OF THE FRONT AND SHOWERS ARE ALREADY
BREAKING OUT SOUTH OF THE ST LOUIS METRO AREA. EXPECT WIDELY
SCATTERED SHOWERS TO CONTINUE ALONG AND SOUTH OF THE FRONT THIS
AFTERNOON AND INTO THIS EVENING...BUT THE MAIN SHOW WILL DEVELOP
ACROSS SOUTHERN NEBRASKA AND NORTHERN KANSAS WHERE INSTABILITY AND
FORCING IS GREATEST. SOME QUESTION AS TO WHAT CONVECTIVE MODE THE
STORMS WILL ULTIMATELY TAKE. INSTABILITY AND SHEAR IS GREAT ENOUGH
FOR SOME ORGANIZATION...AND THE HRRR HAS ALTERNATELY BEEN DEVELOPING
DISCRETE SUPERCELLS...BOW ECHOS...AND OCCASIONALLY MULTICELL
CLUSTERS. THINK EITHER THE MULTICELL CLUSTER OR BOW ECHO IS MOST
LIKELY. FORWARD PROPAGATING CORFIDI VECTORS WOULD MOVE ANY MCS THAT
DEVELOPS EAST-SOUTHEAST INTO WESTERN MISSOURI. STORMS SHOULD RUN
OUT OF INSTABILITY AS THEY APPROACH CENTRAL MISSOURI AND SHOULD BE
IN THE WANING PHASE. WILL CONTINUE THE CHANCE FOR WIDELY SCATTERED
THUNDERSTORMS ON THURSDAY AS FRONT LIFTS BACK ACROSS THE AREA...THEN
ANOTHER SHOT OF PRECIP THURSDAY NIGHT AS A SHORTWAVE RIPPLES ACROSS
IOWA AND MISSOURI ACCOMPANIED BY ANOTHER WEAK COLD FRONT.
CARNEY
&&
.LONG TERM...
ISSUED AT 320 PM CDT WED MAR 28 2012
(SATURDAY THROUGH WEDNESDAY)
PRIMARY CONCERN IN THE SHORT TERM IS POPS TONIGHT THROUGH FRIDAY.
QUASI-STATIONARY FRONT EXTENDS FROM NEAR FARMINGTON WEST-NORTHWEST
BETWEEN COLUMBIA AND SEDALIA TO NEAR TOPEKA. UNSTABLE AIRMASS IS
EVIDENT IN CUMULUS FIELD SOUTH OF THE FRONT AND SHOWERS ARE ALREADY
BREAKING OUT SOUTH OF THE ST LOUIS METRO AREA. EXPECT WIDELY
SCATTERED SHOWERS TO CONTINUE ALONG AND SOUTH OF THE FRONT THIS
AFTERNOON AND INTO THIS EVENING...BUT THE MAIN SHOW WILL DEVELOP
ACROSS SOUTHERN NEBRASKA AND NORTHERN KANSAS WHERE INSTABILITY AND
FORCING IS GREATEST. SOME QUESTION AS TO WHAT CONVECTIVE MODE THE
STORMS WILL ULTIMATELY TAKE. INSTABILITY AND SHEAR IS GREAT ENOUGH
FOR SOME ORGANIZATION...AND THE HRRR HAS ALTERNATELY BEEN DEVELOPING
DISCRETE SUPERCELLS...BOW ECHOS...AND OCCASIONALLY MULTICELL
CLUSTERS. THINK EITHER THE MULTICELL CLUSTER OR BOW ECHO IS MOST
LIKELY. FORWARD PROPAGATING CORFIDI VECTORS WOULD MOVE ANY MCS THAT
DEVELOPS EAST-SOUTHEAST INTO WESTERN MISSOURI. STORMS SHOULD RUN
OUT OF INSTABILITY AS THEY APPROACH CENTRAL MISSOURI AND SHOULD BE
IN THE WANING PHASE. WILL CONTINUE THE CHANCE FOR WIDELY SCATTERED
THUNDERSTORMS ON THURSDAY AS FRONT LIFTS BACK ACROSS THE AREA...THEN
ANOTHER SHOT OF PRECIP THURSDAY NIGHT AS A SHORTWAVE RIPPLES ACROSS
IOWA AND MISSOURI ACCOMPANIED BY ANOTHER WEAK COLD FRONT.
THE FRONT WILL CONTINUE SOUTH INTO THE LOWER MISSISSIPPI VALLEY BY
SATURDAY BRINGING AN END TO THE PRECIP CHANCES FOR THE WEEKEND.
TEMPERATURES SHOULD REMAIN ABOVE NORMAL IN THE UPPER 70S TO THE
LOWER 80S. A SHARP TROF WILL DEVELOP OVER THE PLAINS SUNDAY NIGHT
INTO MONDAY WITH SURFACE CYCLOGENESIS TAKING PLACE OVER THE
NORTHEAST PLAINS OR THE UPPER MIDWEST. SOME TIMING DIFFERENCES ON
MEDIUM RANGE MODELS IS MAKING PRECIP TIMING DIFFICULT...BUT EXPECT
SHOWERS AND THUNDERSTORMS TO BE IN THE AREA MONDAY AND MONDAY
NIGHT...POSSIBLY LINGERING INTO TUESDAY. EXPECTING TEMPERATURES
BEHIND THE FRONT TO BE MORE SEASONABLE IN THE 60S AND LOWER 70S.
CARNEY
&&
.AVIATION...
ISSUED AT 607 PM CDT WED MAR 28 2012
A STATIONARY FRONT STRETCHED FROM SOUTHERN IL ACROSS SOUTHEAST MO
INTO NORTHERN KANSAS EARLY THIS EVENING. THE AIR MASS ALONG AND
SOUTH OF THIS BOUNDARY WAS UNSTABLE AND WAS FUELING A COUPLE OF
AREAS OF THUNDERSTORMS...ONE IN EASTERN KANSAS AND ANOTHER AREA
ACROSS SE MO INTO SRN IL. CURRENT INDICATIONS ARE THE ACTIVITY
OVER EASTERN KS WILL GROW INTO A THUNDERSTORM COMPLEX OR PERHAPS
ANOTHER REGION WILL DEVELOP NEAR THE KS/NEBRASKA BORDER. THE
THOUGHT IS THAT THIS COMPLEX OF STORMS WILL TEND TO MOVE EAST
SOUTHEASTWARD ALONG OR JUST NORTH OF THE STALLED FRONT. IF THIS
SCENARIO PANS OUT IT COULD IMPACT KCOU IN A WEAKENING STATE VERY
LATE TONIGHT TO JUST PAST DAWN ON THURSDAY...DISSIPATING AS IT
CONTINUES TO MOVE ESE THURSDAY MORNING. I HAVE ONLY MENTIONED
PRECIPITATION AT KCOU WITH VFR CONDITIONS ELSEWHERE. SURFACE WINDS
WILL BECOME EASTERLY OVERNIGHT.
SPECIFICS FOR KSTL...
VFR CONDITIONS EXPECTED TO DOMINATE THE PERIOD...THE ONLY IFFY
PERIOD IS MID MORNING ON THURSDAY. LIGHT WINDS EXPECTED TONIGHT
WITH MID/HIGH CLOUDS SPREADING INTO THE AREA OVERNIGHT. A DYING
COMPLEX OF SHOWERS AND THUNDERSTORMS MAY BE OVER CENTRAL MO IN THE
PREDAWN HOURS ON THURSDAY AND IF ANY OF THIS HOLDS TOGETHER AS IT
MOVES ESE...THEN A BRIEF PERIOD OF SHOWERS COULD OCCUR SOMETIME
AFTER 15Z. HAVE KEPT THE FORECAST DRY FOR NOW GIVEN THE LOW ODDS.
GLASS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
622 PM CDT WED MAR 28 2012
.SHORT TERM...
ISSUED AT 320 PM CDT WED MAR 28 2012
(TONIGHT THROUGH FRIDAY)
PRIMARY CONCERN IN THE SHORT TERM IS POPS TONIGHT THROUGH FRIDAY.
QUASI-STATIONARY FRONT EXTENDS FROM NEAR FARMINGTON WEST-NORTHWEST
BETWEEN COLUMBIA AND SEDALIA TO NEAR TOPEKA. UNSTABLE AIRMASS IS
EVIDENT IN CUMULUS FIELD SOUTH OF THE FRONT AND SHOWERS ARE ALREADY
BREAKING OUT SOUTH OF THE ST LOUIS METRO AREA. EXPECT WIDELY
SCATTERED SHOWERS TO CONTINUE ALONG AND SOUTH OF THE FRONT THIS
AFTERNOON AND INTO THIS EVENING...BUT THE MAIN SHOW WILL DEVELOP
ACROSS SOUTHERN NEBRASKA AND NORTHERN KANSAS WHERE INSTABILITY AND
FORCING IS GREATEST. SOME QUESTION AS TO WHAT CONVECTIVE MODE THE
STORMS WILL ULTIMATELY TAKE. INSTABILITY AND SHEAR IS GREAT ENOUGH
FOR SOME ORGANIZATION...AND THE HRRR HAS ALTERNATELY BEEN DEVELOPING
DISCRETE SUPERCELLS...BOW ECHOS...AND OCCASIONALLY MULTICELL
CLUSTERS. THINK EITHER THE MULTICELL CLUSTER OR BOW ECHO IS MOST
LIKELY. FORWARD PROPAGATING CORFIDI VECTORS WOULD MOVE ANY MCS THAT
DEVELOPS EAST-SOUTHEAST INTO WESTERN MISSOURI. STORMS SHOULD RUN
OUT OF INSTABILITY AS THEY APPROACH CENTRAL MISSOURI AND SHOULD BE
IN THE WANING PHASE. WILL CONTINUE THE CHANCE FOR WIDELY SCATTERED
THUNDERSTORMS ON THURSDAY AS FRONT LIFTS BACK ACROSS THE AREA...THEN
ANOTHER SHOT OF PRECIP THURSDAY NIGHT AS A SHORTWAVE RIPPLES ACROSS
IOWA AND MISSOURI ACCOMPANIED BY ANOTHER WEAK COLD FRONT.
CARNEY
&&
.LONG TERM...
ISSUED AT 320 PM CDT WED MAR 28 2012
(SATURDAY THROUGH WEDNESDAY)
PRIMARY CONCERN IN THE SHORT TERM IS POPS TONIGHT THROUGH FRIDAY.
QUASI-STATIONARY FRONT EXTENDS FROM NEAR FARMINGTON WEST-NORTHWEST
BETWEEN COLUMBIA AND SEDALIA TO NEAR TOPEKA. UNSTABLE AIRMASS IS
EVIDENT IN CUMULUS FIELD SOUTH OF THE FRONT AND SHOWERS ARE ALREADY
BREAKING OUT SOUTH OF THE ST LOUIS METRO AREA. EXPECT WIDELY
SCATTERED SHOWERS TO CONTINUE ALONG AND SOUTH OF THE FRONT THIS
AFTERNOON AND INTO THIS EVENING...BUT THE MAIN SHOW WILL DEVELOP
ACROSS SOUTHERN NEBRASKA AND NORTHERN KANSAS WHERE INSTABILITY AND
FORCING IS GREATEST. SOME QUESTION AS TO WHAT CONVECTIVE MODE THE
STORMS WILL ULTIMATELY TAKE. INSTABILITY AND SHEAR IS GREAT ENOUGH
FOR SOME ORGANIZATION...AND THE HRRR HAS ALTERNATELY BEEN DEVELOPING
DISCRETE SUPERCELLS...BOW ECHOS...AND OCCASIONALLY MULTICELL
CLUSTERS. THINK EITHER THE MULTICELL CLUSTER OR BOW ECHO IS MOST
LIKELY. FORWARD PROPAGATING CORFIDI VECTORS WOULD MOVE ANY MCS THAT
DEVELOPS EAST-SOUTHEAST INTO WESTERN MISSOURI. STORMS SHOULD RUN
OUT OF INSTABILITY AS THEY APPROACH CENTRAL MISSOURI AND SHOULD BE
IN THE WANING PHASE. WILL CONTINUE THE CHANCE FOR WIDELY SCATTERED
THUNDERSTORMS ON THURSDAY AS FRONT LIFTS BACK ACROSS THE AREA...THEN
ANOTHER SHOT OF PRECIP THURSDAY NIGHT AS A SHORTWAVE RIPPLES ACROSS
IOWA AND MISSOURI ACCOMPANIED BY ANOTHER WEAK COLD FRONT.
THE FRONT WILL CONTINUE SOUTH INTO THE LOWER MISSISSIPPI VALLEY BY
SATURDAY BRINGING AN END TO THE PRECIP CHANCES FOR THE WEEKEND.
TEMPERATURES SHOULD REMAIN ABOVE NORMAL IN THE UPPER 70S TO THE
LOWER 80S. A SHARP TROF WILL DEVELOP OVER THE PLAINS SUNDAY NIGHT
INTO MONDAY WITH SURFACE CYCLOGENESIS TAKING PLACE OVER THE
NORTHEAST PLAINS OR THE UPPER MIDWEST. SOME TIMING DIFFERENCES ON
MEDIUM RANGE MODELS IS MAKING PRECIP TIMING DIFFICULT...BUT EXPECT
SHOWERS AND THUNDERSTORMS TO BE IN THE AREA MONDAY AND MONDAY
NIGHT...POSSIBLY LINGERING INTO TUESDAY. EXPECTING TEMPERATURES
BEHIND THE FRONT TO BE MORE SEASONABLE IN THE 60S AND LOWER 70S.
CARNEY
&&
.AVIATION...
ISSUED AT 607 PM CDT WED MAR 28 2012
A STATIONARY FRONT STRETCHED FROM SOUTHERN IL ACROSS SOUTHEAST MO
INTO NORTHERN KANSAS EARLY THIS EVENING. THE AIR MASS ALONG AND
SOUTH OF THIS BOUNDARY WAS UNSTABLE AND WAS FUELING A COUPLE OF
AREAS OF THUNDERSTORMS...ONE IN EASTERN KANSAS AND ANOTHER AREA
ACROSS SE MO INTO SRN IL. CURRENT INDICATIONS ARE THE ACTIVITY
OVER EASTERN KS WILL GROW INTO A THUNDERSTORM COMPLEX OR PERHAPS
ANOTHER REGION WILL DEVELOP NEAR THE KS/NEBRASKA BORDER. THE
THOUGHT IS THAT THIS COMPLEX OF STORMS WILL TEND TO MOVE EAST
SOUTHEASTWARD ALONG OR JUST NORTH OF THE STALLED FRONT. IF THIS
SCENARIO PANS OUT IT COULD IMPACT KCOU IN A WEAKENING STATE VERY
LATE TONIGHT TO JUST PAST DAWN ON THURSDAY...DISSIPATING AS IT
CONTINUES TO MOVE ESE THURSDAY MORNING. I HAVE ONLY MENTIONED
PRECIPITATION AT KCOU WITH VFR CONDITIONS ELSEWHERE. SURFACE WINDS
WILL BECOME EASTERLY OVERNIGHT.
SPECIFICS FOR KSTL...
VFR CONDITIONS EXPECTED TO DOMINATE THE PERIOD...THE ONLY IFFY
PERIOD IS MID MORNING ON THURSDAY. LIGHT WINDS EXPECTED TONIGHT
WITH MID/HIGH CLOUDS SPREADING INTO THE AREA OVERNIGHT. A DYING
COMPLEX OF SHOWERS AND THUNDERSTORMS MAY BE OVER CENTRAL MO IN THE
PREDAWN HOURS ON THURSDAY AND IF ANY OF THIS HOLDS TOGETHER AS IT
MOVES ESE...THEN A BRIEF PERIOD OF SHOWERS COULD OCCUR SOMETIME
AFTER 15Z. HAVE KEPT THE FORECAST DRY FOR NOW GIVEN THE LOW ODDS.
GLASS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
918 PM MDT WED MAR 28 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT...
AFTER ANOTHER WARM DAY FOR OUR CWA...A COLD FRONT MOVING E HAS
MOVE INTO OUR W ZONES THIS EVENING. THE AIRMASS IS UNSTABLE...BUT
DRY IN LOWER LEVELS. THE RESULT HAS BEEN ISOLATED WEAK
CONVECTION...AND BRIEFLY GUSTY WINDS IN AN ALMOST INVERTED V-TYPE
SOUNDING PATTERN. A LITTLE STRONGER CONVECTION THAT WAS W OF OUR
CWA TENDING TO WEAKEN AS IT APPROACHES. HRRR RUN INDICATES THIS
WILL REMAIN RATHER ISOLATED AND WEAK. UPDATE TO ADJUST POPS AND
WINDS. SIMONSEN
PREVIOUS SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH
FRIDAY...AN OPEN SHORTWAVE TROUGH AND COLD FRONT MOVES OVER
WESTERN AND CENTRAL MONTANA TODAY. THUNDERSTORMS ARE EXPECTED WITH
THE FRONT. THIS EVENING THE FRONT SPREADS ACROSS NORTHEAST
MONTANA...LOSING SOME OF ITS PUNCH. A FEW THUNDERSTORMS MIGHT MAKE
IT INTO OUR WESTERN ZONES...BUT CAPE THAT IS APPARENT TO OUR WEST
DISSIPATES BY 00Z. BOTH THE RUC AND GFS BRING SCATTERED RAIN
SHOWERS WITH THIS FRONT THIS EVENING...MAINLY OVER PHILLIPS AND
VALLEY COUNTIES. KEPT ISOLATED POPS IN ACROSS THE AREA AFTER
MIDNIGHT. A LEE SURFACE TROUGH SHIFTING EAST ACROSS THE AREA THE
MOSTLY SOUTHEASTERLY WINDS WILL SHIFT TO THE NORTHWEST.
AFTER PASSAGE OF THE TROUGH...FLOW ALOFT BECOMES MOSTLY ZONAL
WHILE SURFACE WINDS BECOME SOUTHWESTERLY THROUGH FRIDAY...WHICH
WILL TREND TEMPERATURES UPWARD.
THICKNESS HEIGHTS BEGIN THURSDAY MORNING AROUND 540DM...THEN
INCREASE TO OVER 550DM BY EVENING. SO EXPECT MAXIMUM TEMPERATURES
TO WARM TO AROUND 15F DEGREES ABOVE NORMAL. WEAK UPPER RIDGING
WILL WILL BRING MOSTLY SUNNY SKIES FOR A MILD DAY.
THICKNESS HEIGHTS INCREASE TO AROUND 560DM ON FRIDAY SO HIGHS COULD
REACH AROUND 25F DEGREES ABOVE NORMAL. HOWEVER A SIGNIFICANT
AMOUNT OF PACIFIC MOISTURE MOVES INTO THE NORTHERN ROCKIES AND
DISTURBANCES IN THE FLOW ALOFT WILL INCREASE CLOUD COVER...WHICH
COULD INITIATE A FEW SHOWERS IN THE AFTERNOON. WHILE MET AND MAV
GUIDANCE SUGGEST WARM TEMPERATURES...OVERCAST SKY COVER COULD
LIMIT MAXIMUM TEMPERATURES LOWER THAN GUIDANCE. SCT
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
THE BULK OF CHANGES WERE MADE IN REGARDS TO THE LATE WEEKEND
SYSTEM. MODELS CONTINUE TO STRUGGLE WITH THE DETAILS OF THE
LOW PRESSURE SYSTEM FOR SATURDAY NIGHT INTO SUNDAY NIGHT. BUT
GIVEN ANY SOLUTION A PATTERN CHANGE IS IN STORE FOR NORTHEAST
MONTANA...WITH COOLER MORE NORMAL TEMPERATURES LINGERING INTO
EARLY NEXT WEEK. THUS CONSERVATIVELY TRENDED UP POPS FOR THE
SATURDAY NIGHT INTO SUNDAY NIGHT TIMEFRAME. ALSO TRENDED UP WINDS
AS SUNDAY INTO MONDAY LOOKS WINDY AS THE SURFACE LOW MOVES
THROUGH. OTHERWISE ANY OTHER TWEAKS WERE MINOR AS UPPER RIDGING
BUILDS IN NEXT WEEK. GILCHRIST
PREVIOUS LONG TERM DISCUSSION...A MODERATELY STRONG LOW PRESSURE
SYSTEM FROM THE W ARRIVES THIS WEEKEND...WHICH MODELS AGREE WITH
AND ALL PRODUCE SIGNIFICANT PRECIP OVER PARTS OF NE MT.
DIFFERENCES THOUGH ON LOCATION IN NE MT...AS MOST...BUT NOT
ALL...RECENT MODELS KEEP THE STRONGER PART OF THE SYSTEM OVER
CANADA. ALSO WITH POOR MODEL HANDLING OF PAST FEW SYSTEMS AND THE
DRY PATTERN OF LATE...WILL GO SOMEWHAT CONSERVATIVE WITH POPS. 2
PERIODS OF CHANCE POPS LOOK PLENTY ADEQUATE.
THE AIRMASS WITH THIS SYSTEM WILL BE UNSTABLE ENOUGH FOR SHOWERY
PRECIP...AND POSSIBLY AN ISOLATED THUNDERSTORM...ALTHOUGH MODELS
TEND OVERLY UNSTABLE IN EARLY SPRING. STRONG COLD ADVECTION
FOLLOWS...BUT THEY VARY QUITE A BIT TOO ON WHETHER THERE WILL BE
ENOUGH COLD ADVECTION FOR SOME PRECIP TO END AS SNOW LATE SAT
NIGHT. ADDED SNOW SHOWER MENTION TO ONLY N VALLEY AND SW PHILLIPS
ZONES. A VERY WINDY DAY SUNDAY THOUGH AS 850 WINDS OF 35 TO 50
KT LIKELY TO MIX TO THE SURFACE.
FOR THE REST OF THE FORECAST PERIOD...POOR MODEL AGREEMENT. MOST
MODELS FAVOR RIDGING WITH DRY WEATHER AND MODEST WARMING. LATEST
GFS WAS AN OUTLIER WITH OTHER MODELS THOUGH AND LOOKS THAT WAY ON
ITS ENSEMBLES AS IT BREAKS THE RIDGE DOWN VERY QUICK TUE/WED.
SIMONSEN
&&
.AVIATION...
VFR CONDITIONS WILL LARGELY DOMINATE AT ALL THE TERMINALS OVER THE
NEXT 24 HOURS. A WEAK FRONTAL PASSAGE THIS EVENING WILL BRING A
FEW SHOWERS WITH MAINLY MID LEVEL CLOUDS. SOUTHEAST WINDS AROUND
10KTS WILL TURN TO THE NORTHWEST BY MIDNIGHT WITH THE FRONT.
NORTHWEST WINDS WILL CONTINUE INTO THURSDAY MORNING AND TURN TO
THE WEST OR SOUTHWEST WITH CLEARING SKIES BY MIDDAY THURSDAY.
&&
.FIRE WEATHER...
WILL CONTINUE TO WATCH THE SOUTHERN HALF OF THE FORECAST AREA THIS
AFTERNOON. METEOROLOGICAL CONDITIONS REMAIN MARGINAL FOR
CRITICAL FIRE WEATHER CONDITIONS...BASED ON RELATIVE HUMIDITIES IN
THE LOWER 20S AND WINDS OF 15-20 MPH. FIRE WEATHER CONDITIONS
COULD BECOME CRITICAL ON FRIDAY AFTERNOON...ALSO BASED ON EXPECTED
WARM TEMPERATURES...RESULTING IN LOW RELATIVE HUMIDITIES...ALONG
WITH SOUTHWEST WINDS OF AROUND 20MPH. SCT
&&
.CLIMATE...
THE FIRST 27 DAYS OF MARCH ARE THE WARMEST ON RECORD IN GLASGOW.
THE AVERAGE TEMPERATURE OF 40.7 DEGREES IS 10.0 DEGREES ABOVE
NORMAL. WE HAVE A GOOD CHANCE OF SETTING THE ALL-TIME RECORD FOR
THE ENTIRE MONTH OF MARCH...WHICH WAS MARCH 1986. MARCH WILL MAKE
FOR THE 9TH STRAIGHT MONTH THAT HAS BEEN WARMER THAN NORMAL.
THE 26 DAY PERIOD FROM THE 2ND TO THE 27TH...ONLY 0.07 INCH OF
PRECIP FELL...WHICH IS TIED FOR 10TH DRIEST. DUE TO 0.33 ON THE
FIRST...MARCH AS A WHOLE WILL NOT RANK AS UNUSUALLY DRY. SIMONSEN
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1033 PM CDT WED MAR 28 2012
.DISCUSSION...
UPDATE THE FORECAST FOR TONIGHT TO DECREASE THE POPS ACROSS THE
NW CWA AND DELAYED THE ONSET OF THE LIKELY POPS INTO SW. OTHERWISE
THE GOING FORECAST IS IN GOOD SHAPE.
DISTINCT AND STRONG WARM FRONT AT 850 MB WAS RIGHT ALONG THE
KS/NEB BORDER THIS EVNG. THIS FNT WILL TRY AND LIFT NWD THROUGH
THE NIGHT AS THE LOW LEVEL JET INCREASES FROM KANSAS INTO SE NEB.
THIS INCREASE IN THE LOW LEVEL JET AND SUBSEQUENT INCREASE IN
MASS CONVERGENCE HAS BEEN RESPONSIBLE FOR THE INCREASE IN
CONVECTION NEAR THE THE BORDER WITH KS. LATEST RUC ANALYSIS INDCS
THAT THERE IS AROUND 1000 J/KG OF MUCAPE RIGHT ALONG THE BORDER
BUT RAPIDLY DROPS OFF FARTHER NORTH. THUS AS STORMS LIFT NWD INTO
THE AREA THEY CONT TO WEAKEN. THERE MAY BE A SLIGHT RISK FOR AN
ISOLATED LARGE HAIL /NEAR QUARTER SIZE/ ALONG THE BORDER...BUT
OTHERWISE THERE IS LITTLE SVR WX THREAT FARTHER NORTH. THE
INCREASE IN THE LOW LEVEL JET SHOULD FOCUS OVER SE NEB AND SW IA
AND THIS IS WHERE WE SHOULD SEE THE HIGHEST CONCENTRATE OF PRECIP.
SHOWERS AND ISO STORMS SHOULD LINGER INTO THU MRNG OVER SW IA. NO
ADDITIONAL UPDATES ARE PLANNED AT THE MOMENT.
BOUSTEAD
&&
.PREV DISCUSSION... /ISSUED 659 PM CDT WED MAR 28 2012/
AVIATION...
00Z TAFS FOR KOMA...KLNK AND KOFK.
SOME CONVECTIVE POTENTIAL WILL EXIST THROUGH MUCH OF THE PERIOD
AT ALL THREE SITES. WARM FRONT LOCATED SOUTH OF THE AREA AT 00Z
WILL LIFT NORTHEAST TONIGHT IN ADVANCE A COLD FRONT MOVING INTO
THE AREA ON THURSDAY AFTER 18Z. LOWER CIGS SPREAD INTO THE AREA
AFTER 06Z WITH MVFR CONDITIONS DEVELOPING AND PERSIST
THROUGH THE REMAINDER OF THE FORECAST PERIOD.
PREV DISCUSSION... /ISSUED 258 PM CDT WED MAR 28 2012/
DISCUSSION...
MAIN FORECAST PROBLEM TONIGHT WILL BE INCREASING CHANCES FOR CONVECTION
AS A WEAK IMPULSE EJECTING OFF THE HIGH PLAINS COMBINES WITH A NORTHWARD
ADVANCING WARM FRONT MOVING INTO THE REGION. ELEVATION CONVECTION
WAS ALREADY ONGOING ACROSS SOUTH CENTRAL NEBRASKA. BELIEVE THIS
WILL DEVELOP FURTHER EAST THROUGH THE EVENING ALONG THE NEBRASKA
AND KANSAS BORDER REGION...THUS HAVE INCREASED POPS IN THAT
REGION THROUGH THE EVENING. COORDINATED WITH SPC EARLIER THAT THE
SLIGHT RISK MAY NEED TO MOVED JUST SLIGHTLY NORTHWARD TO ACCOUNT
FOR SOME MARGINAL HAIL IN THAT AREA THIS EVENING. AS WE MOVE
TOWARD LATE EVENING AND OVERNIGHT...BELIEVE THAT THERE`S AT LEAST
A CHANCE OF ADDITIONAL ELEVATION CONVECTION FURTHER NORTH UP THE
MISSOURI RIVER...PUSHING SLOWLY EAST THROUGH DAYBREAK THURSDAY.
A FEW LINGERING SHOWERS OR ISOLATED STORMS MAY BE ONGOING EARLY
THURSDAY MORNING ALONG AND EAST OF THE MISSOURI RIVER...BUT MOST
OF EASTERN NEBRASKA MAY ACTUALLY BE DRY. BY MIDDAY THURSDAY...THE
WARM FRONT WILL PROBABLY BE LOCATED ALONG THE NE/KS BORDER REGION
AGAIN...WHILE A COLD FRONT ADVANCES FROM THE NORTHWEST. THE MAIN
SEVERE THREAT WILL BE ALONG THE WARM FRONT IN SOUTHEAST NEBRASKA
AND SOUTHWEST IOWA...BUT GIVEN SHEAR ALONG THE ADVANCING COLD
FRONT...WOULD EXPECT SOME HAIL POTENTIAL THERE AS WELL. PRECIP
CHANCES INCREASE NOTABLY THROUGH THE AFTERNOON THROUGH PEAK
HEATING. THERE STILL REMAINS SOME UNCERTAINTY HOW FAR NORTH THE
WARM FRONT WILL MOVE THOUGH. EVENING THUNDERSTORMS SHOULD CONTINUE
TO PUSH OUT OF HERE THROUGH MIDNIGHT TOMORROW NIGHT.
THEN WE WARM BACK UP FRIDAY AND SATURDAY AS RIDGING ALOFT BUILD
INTO THE AREA WITH DRY CONDITIONS THAT LINGER THROUGH SUNDAY WITH
HIGHS BACK INTO THE LOWER TO MID 80S. ANOTHER WAVE MOVES INTO THE
REGION SUNDAY NIGHT WITH AN ATTACHED COLD FRONT. THIS WILL BRING
ANOTHER CHANCE OF THUNDERSTORMS...AND POSSIBLY SOME LINGERING
SHOWERS ON MONDAY. MORE IMPORTANTLY...IT WILL BRING SHARPLY COOLER
TEMPERATURES AGAIN WITH HIGHS BACK IN THE LOWER TO MIDDLE 60S AND
LOWS IN THE UPPER 30S AND LOWER 40S...BUT DRY CONDITIONS.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
237 AM CDT TUE MAR 27 2012
.UPDATE...
.DISCUSSION...
PV15 ANOMALY ACROSS SWRN SD HAS DECIDED TO PRODUCE STRONG TO HIGH
WINDS ACROSS THE ERN NEBRASKA PANHANDLE AS FAR SOUTH AS CHAPPELL.
SO A WIND ADVISORY IS IN PLACE UNTIL 12Z. BY THE RUC SUGGESTS THIS
DISTURBANCE WILL HAVE MOVED OFF TO THE NORTHEAST BY THEN. NEDOR
OBS HAVE BEEN COMING IN EVER 15 MINUTES. SO WE WILL MONITOR THE
OBS FOR A POSSIBLE UPGRADE IF NECESSARY. MERRIMAN PROFILER RUNNING
STRONG SINCE 02Z WITH 40 TO 55 KTS AT THE LOWEST GATE. NEARLY
STEADY AT 50-55KT ABOVE THAT LEVEL.
&&
.PREV DISCUSSION... /ISSUED 1221 AM CDT TUE MAR 27 2012/
UPDATE...
AVIATION...
FOR THE KLBF AND KVTN TERMINALS THROUGH 06Z WEDNESDAY.
INTENSE LOW PRESSURE WILL TRACK INTO THE ARROWHEAD OF MN OVER THE
NEXT 24 HOURS WITH GUSTY WESTERLY WINDS EXPECTED OVERNIGHT AND ON
TUESDAY. WESTERLY WINDS WILL BE STRONGEST OVER NORTHERN
NEBRASKA...WHERE WIND GUSTS UP TO 35 KTS ARE POSSIBLE. GUSTS UP TO
25 KTS ARE POSSIBLE OVER SOUTHWESTERN NEBRASKA. SKIES WILL BE CLEAR
THROUGH TUESDAY AFTERNOON...WITH SOME HIGH CLOUDINESS EXPECTED AFTER
00Z WEDNESDAY WITH CIGS AOA 20000 FT AGL.
PREV DISCUSSION... /ISSUED 1150 PM CDT MON MAR 26 2012/
UPDATE...EXPIRED THE HIGH WIND WARNING AND WIND ADVISORY FOR ALL OF
WESTERN AND NORTH CENTRAL NEBRASKA. WINDS AHEAD OF THE FRONT ARE
GUSTING TO 40 MPH...WHILE BEHIND THE FRONT...WINDS ARE GUSTING UP TO
30 MPH. THESE WINDS ARE EXPECTED TO DIMINISH FURTHER AFTER 2 AM
CDT.
PREV DISCUSSION... /ISSUED 955 PM CDT MON MAR 26 2012/
AVIATION...
FOR THE KLBF AND KVTN TERMINALS THROUGH 00Z WEDNESDAY.
STRONG SOUTHWESTERLY WINDS WITH GUSTS UP 40 KTS ARE LIKELY THROUGH
LATE EVENING AHEAD OF AN APPROACHING COLD FRONT. WINDS WILL SHIFT TO
THE WEST OVERNIGHT WITH GUSTS OVER 30 KTS LIKELY. WESTERLY WINDS
WILL RANGE FROM 15 TO 25 KTS...WITH GUSTS TO 30 KTS ON TUESDAY. VFR
SKIES ARE EXPECTED OVER THE NEXT 24 HRS WITH CIGS ABOVE 15000 FT
AGL.
SYNOPSIS...
H5 CLOSED LOWS OFF PACIFIC NORTHWEST AND THE NORTHEAST US WITH A
STRONG NEGATIVELY WAVE PUSHING ACROSS THE COLORADO ROCKIES THIS AFTERNOON.
DISCUSSION...
MODELS IN GOOD AGREEMENT WITH THE EVOLUTION OF THE FORECAST
THROUGH THURSDAY AND THEN SOME TIMING ISSUES TAKE HOLD.
TONIGHT THOUGH TUESDAY...
GOOD MIXING THIS AFTERNOON ACROSS THE FORECAST AREA...WITH SFC DEW
POINTS LOWERING AHEAD OF THE ACTUAL DRY LINE. DRY LINE AS OF MID
AFTERNOON EXTENDED SOUTH FROM A SFC LOW ACROSS FAR WESTERN NEBRASKA
PANHANDLE INTO EASTERN CO. THIS DRY LINE WILL BULGE NORTHEAST THIS
EVENING AS A PACIFIC COLD FRONT OVER TAKES IT. SOME LIMITED MOISTURE
RECOVERY IS POSSIBLE TO THE EAST OF THE DRY LINE/COLD FRONT ACROSS
WESTERN NEB EARLY THIS EVENING...AND WITH DECENT FORCING ARRIVING
ABOUT THE SAME TIME...STILL SOME CHANCE FOR ISOLATED T-STORMS. IF A
STORM DEVELOPS LARGE HAIL AND DAMAGING WINDS ARE POSSIBLE...MAINLY
ACROSS NORTH CENTRAL NEB.
HIGH WIND WARNING WILL REMAIN IN EFFECT THIS EVENING FOR THE NEB
PANHANDLE...AS RAPID PRESSURE RISE COUPLET INDICATED IN THE MODELS
SUPPORTS VERY STRONG WIND POTENTIAL BEHIND THE PACIFIC COLD FRONT.
FURTHER EAST WILL GO WITH A WIND ADVISORY AS PRESSURE RISES NOT AS
INTENSE.
FOLLOWED THE ALL BLENDS THROUGH THE EXTENDED WITH A FEW TWEAKS TO
PRECIPITATION FORECAST NEAR THE END OF THE FORECAST WITH GFS MUCH
FASTER THAN EC AND GEM HOLDING A TROUGH OFF THE WEST COAST.
NICE RIDGE MOVES EAST INTO NORTHERN
PLAINS WEDNESDAY WITH TEMPERATURES INTO THE MID 70S. NEXT SEVERAL
SYSTEMS MOVE ALONG THE CANADIAN BORDER WITH TRAILING WAVES INTO
THE FORECAST AREA. BEST CHANCES LOOK TO BE THURSDAY NIGHT INTO
FRIDAY WITH SOME MOISTURE RETURN ACROSS THE SOUTHERN PLAINS
WEDNESDAY NIGHT.
FIRE WEATHER...
TUESDAY TO CONTINUE BREEZY BUT BELOW ADVISORY CRITERIA AS UPPER
LOW SHEARS OUT OF THE NORTHERN PLAINS. MINIMUM RELATIVE HUMIDITIES
QUITE LOW AND HAVE PUT OUT A RED FLAG WARNING FOR THE ENTIRE FORECAST
AREA AS SPC HAS HIGHLIGHTED MOST OF WESTERN AND CENTRAL NEBRASKA
WITH CRITICAL CONDITIONS. RED FLAG WARNING IN EFFECT FOR ALL AREAS
TUESDAY. LOW PRESSURE TO OUR NORTH WILL CREATE WESTERLY DRY
DOWNSLOPE CONDITIONS ACROSS THE AREA. CONTINUE WARM WEATHER...WITH
HIGHS IN THE UPPER 60S TO MID 70S.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...RED FLAG WARNING FROM NOON CDT
/11 AM MDT/ TODAY TO 7 PM CDT /6 PM MDT/ THIS EVENING FOR
NEZ204-206-208>210-219.
WIND ADVISORY UNTIL 6 AM MDT EARLY THIS MORNING FOR NEZ004-022-
023-035-056-094.
&&
$$
SHORT TERM/EXTENDED...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1121 PM CDT MON MAR 26 2012
.AVIATION...
06Z TAFS FOR KOMA...KLNK AND KOFK.
VFR CONDITIONS THROUGH THE PERIOD WITH COLD FRONT MOVING
THROUGH THE AREA AFTER 06Z. STRONG SOUTH WIND DECREASING
AND BECOMING WESTERLY BEHIND FRONT. ISOLATED THUNDERSTORM
POSSIBLE ALONG FRONT BUT LOW POP PRECLUDES MENTION AT
THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 330 PM CDT MON MAR 26 2012/
DISCUSSION..
WATER VAPOR IMAGERY THIS AFTERNOON SHOWING FEATURE OF INTEREST...
SHORTWAVE TROF...CROSSING THE ROCKIES. MODELS IN QUITE GOOD
AGREEMENT THIS WAVE WILL LIFT QUICKLY ACROSS THE NORTHERN PLAINS
AND NEAR THE WESTERN GREAT LAKES REGION BY TUESDAY AFTERNOON.
ATTENDANT SFC LOW CURRENTLY OVER NRN WY WILL DEEPEN SIGNIFICANTLY
THROUGH TONIGHT AS 500MB HEIGHT FALLS DROP 16DAM. INCOMING FRONT
WITH THIS SYSTEM WILL BE THE FOCUS FOR POSSIBLE THUNDER SOMETIME
AFTER 06Z. HIRES WRF AND RUC13 ARE ADVERTISING MODERATE INSTABILITY
ALONG WITH DECENT MOISTURE POOLING ALONG THE BNDRY/SFC TROF WITH BEST
CHANCE FOR DEVELOPMENT MAINLY SOUTH OF I-80. ON TUESDAY TIGHT SURFACE
PRESSURE GRADIENT SHOULD PREVAIL OVER MOST OF THE REGION...
PARTICULARLY NORTH. FIRE WEATHER ISSUE COMING TO PLAY THEN TUESDAY
AFTERNOON AS COMBINATION OF WIND AND MIXING DRIVES DEW POINTS/RH
DOWN CLOSE TO RED FLAG WARNING CRITERIA. FOCUS FOR THUNDER THEN
SHIFTS TO THE SOUTH WEDNESDAY/WEDNESDAY NIGHT AS BOUNDARY LAYER
MOISTURE CONVERGENCE INCREASES/INSTABILITY AXIS SETS UP ALONG THE
NEB/KS BORDER...THEN RE-ORIENTS THURSDAY/THURSDAY NIGHT OVER THE
CWA. AS FOR DAY 4-7...AT THIS POINT NOT INCLINED TO MAKE ANY
SIGNIFICANT CHANGES TO THE FORECAST DUE TO SIGNIFICANT GFS/ECM
DIFFERENCES PER LATEST RUN. OTHERWISE STILL LOOKING LIKE MAX TEMPS
WILL BE HOVERING AROUND 20 DEG ABOVE NORM HEADING INTO NEXT
WEEKEND.
DEE
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR NEZ045-052-053-066-067-078-088-089.
RED FLAG WARNING FROM NOON TO 8 PM CDT TUESDAY FOR NEZ011-012-
015>018-030>034-042>044-050-051-065.
IA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR IAZ055-056-069.
RED FLAG WARNING FROM NOON TO 8 PM CDT TUESDAY FOR IAZ043.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1253 AM EDT TUE MAR 27 2012
.SYNOPSIS...
SURFACE HIGH PRESSURE NEAR HUDSON BAY WILL BUILD INTO THE NORTH
COUNTRY THROUGH TUESDAY. THIS WILL RESULT IN MAINLY CLEAR SKIES
TONIGHT WITH CHILLY TEMPERATURES. ON TUESDAY...PLENTY OF SUNSHINE IS
ANTICIPATED WITH TEMPERATURES IN THE 30S TO NEAR 40...ALONG WITH
NORTHWEST WINDS OF 10 TO 20 MPH. A WARM FRONT WILL PRODUCE
INCREASING CLOUDS WITH SCATTERED RAIN AND SNOW SHOWERS BY
WEDNESDAY MORNING.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1015 PM EDT MONDAY...SATELLITE LOOP AND SURFACE
OBSERVATIONS SHOWING SKIES HAVE CLEARED OUT ACROSS THE REGION AT
THIS TIME. HOWEVER...GUSTY NORTHWEST SURFACE WINDS CONTINUE ACROSS
THE REGION OVERNIGHT. THESE GUSTY WINDS WILL ALLOW FOR GOOD MIXING
ACROSS THE REGION WHICH WILL CAUSE TEMPERATURES TO ONLY FALL OFF
SLOWLY OVERNIGHT. BASED ON LATEST GFS LAMP GUIDANCE HAVE UPPED MIN
TEMPERATURES IN A FEW LOCATIONS OVERNIGHT. OTHERWISE...THE
FORECAST IS IN GOOD SHAPE. HAVE UPDATED THE GRIDS WITH THE LATEST
SURFACE OBSERVATIONS.
PREVIOUS DISCUSSION FROM 345 PM EDT MONDAY...BIG PICTURE SHOWS
DEEP MID/UPPER LVL TROF ACRS THE NE CONUS WITH RIBBON OF
SUBSIDENCE/DRY AIR ALOFT BUILDING INTO OUR REGION. MEANWHILE...SFC
ANALYSIS SHOWS 1032MB HIGH PRES BUILDING INTO OUR CWA....WITH SFC
DWPTS IN THE SINGLE DIGITS ABOVE/BLW ZERO THIS AFTN. THIS AIRMASS
WL BE ACRS OUR FA ON TUES...ALONG WITH PLENTY OF SUNSHINE. FCST
CHALLENGE TONIGHT WL BE TEMPS...FOLLOWED BY DWPTS/RH PARAMETERS ON
TUES...ALONG WITH SFC WINDS. UPSTREAM MINS LAST NIGHT SHOW MANY
TEMPS IN THE SINGLE DIGITS WITH A FEW BLW ZERO READINGS SOUTH OF
HUDSON BAY...ASSOCIATED WITH 925MB TEMPS -20C. GIVEN SOME GRADIENT
ACRS OUR CWA....LIMITED SNOW PACK...AND SLIGHTLY WARMER 925MB
TEMPS...WL MENTION LOWS FROM 0F AT SLK/MTNS TO 5 TO 10F
CENTRAL/NORTHERN VT TO 10 TO 15F CPV/SLV. RUC13 AND NAM12 RH
PROFILES STILL SHOW SOME 975MB TO 800MB RH ACRS THE NEK/NORTHERN
VT MTNS THRU 03Z...THEREFORE WL TRY TO SHOW SOME CLOUDS...BUT
OTHERWISE MAINLY CLR SKIES TONIGHT...WITH NW WINDS OF 10 TO 20
WITH GUSTS TO 30 MPH UNTIL MTN...DECREASING TO 5 TO 15 MPH WITH
GUSTS TO 20 MPH TWD MORNING.
TUESDAY...SFC HIGH PRES CENTERED OVER THE OTTAWA VALLEY AT 12Z WL
SHIFT INTO NORTHERN NY BY 15Z AND INTO THE CPV BY 18Z TUES...WITH A
WEAKENING PRES GRADIENT. SOUNDINGS SHOW MIXED LAYER WINDS BTWN 15
AND 25 MPH THRU NOON...ESPECIALLY CENTRAL/EASTERN VT...BUT
DECREASING AS GRADIENT SLACKENS DURING THE AFTN HRS TO 5 TO 15 MPH.
AT VSF...SOUNDING SHOWS MIXED LAYER WINDS OF 25 TO 30 KNTS...THRU
16Z...HELPING TO PRODUCE SFC WIND GUSTS TO 30 MPH...DURING THE
MORNING HRS. SOUNDINGS SHOW GOOD MIXING TO 900MB ON TUES
AFTN...WHICH WL TRANSFER SOME VERY DRY AIR TO THE SFC. UPSTREAM OBS
UNDER SFC HIGH PRES SHOWS DWPTS BTWN -9F AND +5F...COMBINED WITH
ANTICIPATED HIGHS IN THE 30S ON TUES...RESULTS IN MIN RH VALUES BTWN
10% AND 18%...WITH LOWEST VALUES ACRS THE SLV/NORTHERN NY ZNS ON
TUES AFTN. GIVEN DEEP DRY LAYER...EXPECT PLENTY OF SUNSHINE WITH
TEMPS 5 TO 10 DEGREES BLW NORMAL.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 345 PM EDT MONDAY...PROGRESSIVE MID/UPPER LVL PATTERN WL DEVELOP
ACRS THE NE CONUS...WITH CHANGEABLE WX ANTICIPATED. ON TUES
NIGHT...COMBINATION OF RETURN SOUTHERLY FLW AND DEVELOPING TIGHT
SW TO NE THERMAL GRADIENT WL MAKE FOR A DIFFICULT LOW TEMP FCST.
GIVEN...VERY DRY AIR IN PLACE AND SFC DWPTS IN THE SINGLE
DIGITS...FEEL TEMPS WL QUICKLY DROP IN THE EARLY HRS...THEN
INCREASE AFT MIDNIGHT AS WINDS/CLOUDS INCREASE. THINKING LOWS WL
RANGE FROM 5 TO 10F NEK TO 20 TO 25F SLV/CPV. GFS/NAM ARE HANDLING
MOISTURE/LIFT PROFILES ASSOCIATED WITH WAA DIFFERENTLY AND THE
ACCOMPANYING QPF. NAM IS MUCH MORE AGGRESSIVE WITH QPF FIELDS ACRS
OUR CENTRAL/NORTHERN CWA...WITH AMOUNTS NEAR 0.25"...WHILE GFS IS
A TRACK TO 0.10". GIVEN...VERY DRY AIRMASS IN PLACE AHEAD OF 5H
VORT AND WAA LIFT...AND DEVELOPING SOUTHERLY FLW...WL TREND TWD
THE DRIER GFS SOLUTION. WL MENTION CHC POPS TO LOW LIKELY POPS
ACRS NNY INTO NORTHERN VT MTNS AFT 06Z WEDS...WITH SOME LIGHT SNOW
ACCUMULATION POSSIBLE (TRACE TO 1"). INITIALLY THERMAL PROFILES
SUPPORT ALL SNOW...AS 1000 TO 500MB THICKNESS VALUES ARE BLW 540
AND PROGGED 85H TEMPS ARE BTWN -2C AND -4C. BEST 850 TO 500MB RH
AND 700 TO 500MB OMEGA LIFTS FROM SW TO NW ACRS OUR CWA BTWN 06Z
AND 15Z WEDS. AFTER 15Z...BEST MOISTURE/LIFT IS ACRS OUR EXTREME
NORTHERN ZNS...AS WARM ADVECTS INTO OUR CWA. LOCAL 4KM AND NAM
SHOWS SOME LLVL DAMMING OF COLD AIR...ESPECIALLY NEK AND EXTREME
NORTHERN SLV ON WEDS...CREATING A VERY TIGHT THERMAL GRADIENT.
WITH CLRING SKIES PARTS OF THE SLV FROM GOUVERNEUR TO
POTSDAM/CANTON WL WARM INTO THE L60S...WHILE NEAR MSS COULD
STRUGGLE TO REACH 50F. ELSEWHERE...GIVEN SHARP 925MB THERMAL
GRADIENT ACRS OUR CWA...TEMPS WL BE TRICKY...WL MENTION L/M50S CPV
TO L/M40S NEK/MTNS OF VT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 354 PM EDT MONDAY...GFS/ECMWF IN FAIRLY GOOD AGREEMENT ON
THE OVERALL PATTERN FOR THURSDAY AND FRIDAY...WITH INCREASING
DISAGREEMENT BEYOND FRIDAY. TEMPERATURES THROUGH THE EXTENDED ARE
CLOSE TO NORMAL THROUGH FRIDAY...TRENDING ABOVE NORMAL BY THE
WEEKEND.
SYSTEM EXPECTED TO IMPACT THE REGION ON WEDNESDAY BEGINS TO EXIT
NEW ENGLAND THURSDAY. MAINTAINED CHANCE PRECIPITATION PROBABILITIES
FOR THURSDAY AFTERNOON...THOUGH HAVE GONE WITH SLIGHT CHANCE
PRECIPITATION PROBABILITIES FOR THURSDAY AFTERNOON/EVENING ALONG
EASTERN-FACING SLOPES WHERE UPSLOPE SHOWERS MAY CONTINUE TO LINGER.
NORTHERLY FLOW THURSDAY NIGHT ALLOWS 850MB TEMPERATURES TO FALL
INTO THE -8 TO -10C RANGE. HIGHS ON THURSDAY REACH INTO THE 40S
WITH LOWS IN THE 20S TO AROUND 30 IN THE CHAMPLAIN AND SAINT
LAWRENCE VALLEYS. WEAK HIGH PRESSURE THEN BUILDS IN FOR FRIDAY WITH
TEMPERATURES A COUPLE OF DEGREES COOLER THAN THURSDAY.
FOR THE WEEKEND...DIFFERENCES EMERGE IN TIMING REGARDING A
DEVELOPING LOW PRESSURE SYSTEM MOVING IN FROM THE SOUTHERN GREAT
LAKES/OHIO VALLEY REGION. 12Z GFS TRACKS THE LOW FURTHER TO THE
NORTH ON SATURDAY THAN THE 12Z ECMWF...AND IS ALSO MORE PROGRESSIVE
THAN THE 12Z ECMWF. DIVERGENT SOLUTIONS CONTINUE INTO EARLY NEXT
WEEK. HAVE OPTED TO NOT STRAY TOO FAR FROM CONTINUITY...SO HAVE
KEPT MODERATING TEMPERATURES AND SLIGHT CHANCE PRECIPITATION
PROBABILITIES GOING THROUGH THE REST OF THE EXTENDED.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...STRONG PRESSURE GRADIENT IS IN PLACE ACROSS
THE NORTH COUNTRY EAST OF SFC HIGH CENTERED OVER THE ERN GREAT LAKES
REGION. THIS WILL MAINTAIN N-NW WINDS THIS MORNING OF 10-20 KTS WITH
GUSTS AS HIGH AS 30 KTS AT BTV/MPV. WINDS GRADUALLY LESSEN THROUGH
THE DAYLIGHT HRS FROM WEST-EAST AS SFC HIGH MOVES IN AND CRESTS OVER
THE REGION AT 00Z WEDNESDAY. VERY DRY AIR MASS WILL PROVIDE SKC AND
NO VSBY OBSTRUCTIONS THRU THE DAY. AN APPROACHING WARM FRONT AND
ASSOCIATED LARGE-SCALE ASCENT BRINGS MID-LEVEL CLOUDS IN FROM W-E
DURING TUESDAY NIGHT...WITH CEILINGS GENERALLY 7-8 KFT BY 06Z
WEDNESDAY...AND THEN LOWERING TO 4-5 KFT BY 12Z WEDNESDAY.
OUTLOOK 12Z WEDNESDAY THROUGH SATURDAY...WAVE OF LOW PRESSURE MOVING
NW-SE OVER THE REGION BRINGS PERIODS OF LIGHT RAIN WEDNESDAY...FOLLOWED
BY LINGERING SNOW SHOWERS WEDNESDAY NIGHT INTO THURSDAY MORNING.
COULD SEE SOME MVFR CONDITIONS BY WEDNESDAY AFTN...AND GENERALLY
MVFR WITH BRIEF INTERVALS OF IFR IN -SHSN DURING WEDNESDAY NIGHT
INTO EARLY THURSDAY MORNING. BEST IFR POTL AT SLK/MPV 06-18Z
THURSDAY. NW FLOW CONTINUES THURSDAY NIGHT AND FRIDAY...BUT WITH
DRIER AIR MOVING IN SHOULD SEE A RETURN TO VFR AREAWIDE FOR
FRIDAY. RIDGE OF SFC HIGH PRESSURE SHIFTING EWD FROM THE GREAT
LAKES FOR FRIDAY SHOULD BRING LIGHT N-NW WINDS AND AID IN THE
RETURN TO DRIER/VFR CONDITIONS. NEXT WAVE OF LOW PRESSURE MAY STAY
JUST TO OUR SOUTH SATURDAY...SO JUST A SLIGHT CHANCE OR CHANCE OF
RAIN SHOWERS AT THE TERMINALS AT THAT POINT...AND MAINLY FOR
SLK/RUT BASED ON CURRENT INDICATIONS.
&&
.FIRE WEATHER...
AS OF 345 PM EDT MONDAY...CONDITIONS CONTINUE TO REMAIN FAVORABLE ON
TUESDAY FOR POTENTIAL FIRE WEATHER CONCERNS. TEMPERATURES WILL
START OUT COLD...BUT HUMIDITY RECOVERIES OVERNIGHT TONIGHT WILL BE
FAIR. MIXING DEVELOPS EARLY AND WITH THE DRIEST PORTION OF THE
CANADIAN HIGH MOVING DOWN OVER US...THE IDEA OF SHARPLY FALLING
HUMIDITIES LATE MORNING AND AFTERNOON IS A GOOD BET. THIS WILL
RESULT IN AFTERNOON RELATIVE HUMIDITIES FALLING INTO THE 12 TO 18
PERCENT RANGE. AS MENTIONED EARLIER...PRESSURE GRADIENT WILL BE
STRONGEST IN THE MORNING AND THEN TAPER OFF IN THE
AFTERNOON...NEVERTHELESS THE POTENTIAL FOR WIND GUSTS TO 25 MPH
WILL EXIST...ESPECIALLY ACROSS VERMONT. FULL SUN WILL HELP DRY THE
FINE FUELS...WHICH GOT A REPRIEVE FROM THE LIGHT SNOW/CLOUD COVER
ON MONDAY. FORESTRY PERSONNEL INDICATE ABNORMALLY DRY FUELS
OVERALL...THUS THE SITUATION WILL BE EXAMINED CLOSELY FOR POSSIBLY
UPGRADE TO A RED FLAG WARNING GIVEN THE EXPECTED WEATHER
CONDITIONS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...FIRE WEATHER WATCH FROM 11 AM EDT THIS MORNING THROUGH THIS
EVENING FOR VTZ001>012-016>019.
NY...FIRE WEATHER WATCH FROM 11 AM EDT THIS MORNING THROUGH THIS
EVENING FOR NYZ026>031-034-035-087.
&&
$$
SYNOPSIS...TABER
NEAR TERM...WGH
SHORT TERM...TABER
LONG TERM...LOCONTO
AVIATION...BANACOS
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1003 PM EDT WED MAR 28 2012
.SYNOPSIS...
A COLD FRONT WILL ADVANCE SOUTHEAST FROM THE MID ATLANTIC INTO THE
CAROLINAS THURSDAY MORNING. WEAK HIGH PRESSURE OVER ONTARIO WILL
NOSE SOUTHWARD INTO OUR AREA THURSDAY AFTERNOON INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 PM EDT WEDNESDAY...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH AN APPROACHING COLD FRONT
HAVE REMAINED GENERALLY TO THE NORTH OF THE AREA THIS EVENING.
HOWEVER... THE LATEST HI-RES MODELS CONTINUE TO INDICATE SOME OF
THIS ACTIVITY MOVING INTO/DEVELOPING ACROSS OUR NORTHERN PIEDMONT
AND NORTHERN COASTAL PLAIN COUNTIES AS RAIN COOLED OUTFLOW FROM
CURRENT ACTIVITY ACROSS SOUTHERN VA HELPS TO OVERCOME THE NEAR
SURFACE STABLE LAYER. THIS ACTIVITY HAS DECREASED IN COVERAGE OVER
THE LAST SEVERAL HOURS THOUGH... THANKS IN PART TO A STABILIZING
BOUNDARY LAYER AND LACK OF ANY SIGNIFICANT UPPER DYNAMICS.
HOWEVER... GIVEN WESTERLY DEEP LAYER SHEAR OF AROUND 30 TO 40 KTS
AND STEEP MID LEVEL LAPSE RATES OF AROUND 7.5-8 DEGREES C/KM (WHICH
IS ALSO HELPING TO KEEP THE STORMS GOING) EXPECT WE COULD SEE SOME
STRONG WINDS GUSTS AND SMALL HAIL WITH THE STRONGEST STORMS (HIGHEST
THREAT AREA BASED ON CURRENT RADAR APPEARS TO CURRENTLY BE ACROSS
THE FAR NE PIEDMONT NEAR THE NC/VA BORDER AND THE FAR NORTHERN
COASTAL PLAIN)... WITH A VERY SMALL/WANING POTENTIAL OF AN ISOLATED
SEVERE STORM. THE LATEST HRRR SHOWS THE SHOWERS AND STORMS GENERALLY
ENDING ACROSS OUR AREA BY AROUND 05/06Z OR SO... WITH GENERALLY
ISOLATED TO SCATTERED COVERAGE ACROSS THE AFOREMENTIONED AREAS
THROUGH THEN. WILL CONTINUE TO GO WITH CHANCE POPS ACROSS THE FAR
NORTH WITH SLIGHT CHANCE POPS FOR SHOWERS AND STORMS AS FAR SOUTH AS
U.S. HIGHWAY 64... THROUGH 06/07Z. THUS... STILL THINK GIVEN THE
LACK OF APPRECIABLE UPPER FORCING AND STABILIZING BOUNDARY LAYER
THAT WE WILL SEE THE SHOWERS AND STORMS COME TO AN END BY THEN.
THE ACTUAL FRONT DOES NOT START TO PUSH SOUTHWARD THROUGH THE AREA
UNTIL AROUND 12Z THURSDAY... WHICH IS CURRENTLY EXTENDS FROM PORTION
OF SOUTHERN PA WSW`WARD INTO WV AND NORTHERN KY. THUS... WILL
CONTINUE TO GO WITH MILD OVERNIGHT LOWS RANGING FROM 56-60 DEGREES.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 305 PM WEDNESDAY...
THURSDAY...SURFACE COLD FRONT WILL DRIFT SWD ACROSS THE SOUTHERN
COUNTIES EARLY THU MORNING. WHILE MOISTURE THROUGH THE COLUMN
ADEQUATE TO SUPPORT A FEW SHOWERS...FORCING WEAK OR NON-EXISTENT.
THUS ASIDE FROM SOME CLOUDINESS AND THE SURFACE WINDS SHIFTING TO
THE NW...FRONTAL PASSAGE WILL GO THROUGH VIRTUALLY UNEVENTFUL.
SUBSIDENCE BEHIND THE EXITING TROUGH WILL AID TO QUICKLY DIMINISH
CLOUD COVERAGE WITH MOSTLY SUNNY SKIES EXPECTED ALL LOCALES BY LATE
MORNING. WHILE 850MB NW...TEMP ADVECTION NEUTRAL OR SLIGHT CAA.
SINCE FLOW HAS DEFINITIVE DOWNSLOPE COMPONENT...ANY CAA WILL BE
OFFSET BY THE COMPRESSIONAL WARMING. MOS GUIDANCE IN THE 80-85
DEGREE RANGE APPEARS A TOUCH OVERDONE...SO FAVOR MAX TEMPS IN THE
UPPER 70S FAR NORTH TO LOWER 80S SOUTH.
THURSDAY NIGHT...HIGH PRESSURE CENTERED OVER ONTARIO WILL NOSE SWD
INTO CENTRAL NC. THIS WEATHER FEATURE SHOULD PROVIDE US WITH CLEAR
SKIES AND LIGHT NE FLOW. THIS WILL LEAD TO COOLER TEMPS WITH MIN
TEMPS MID 40S NE TO LOW/MID 50S FAR SOUTH.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM WEDNESDAY...
ON FRIDAY WE`LL SEE THE HIGH PRESSURE TO OUR NORTH MOVE OFFSHORE AND
THE OLD COLD FRONT TO OUR SOUTH BEGIN TO LIFT NORTH AS A WARM FRONT
IN ADVANCE OF THE NEXT SHORT WAVE TO OUR WEST CROSSING THE OHIO
RIVER VALLEY. AFTER A MAINLY CLEAR START TO THE DAY...EXPECT TO SEE
INCREASING CLOUDINESS LATER IN THE DAY AND WARMING TEMPS WITH
SOUTHWEST LOW LEVEL FLOW INCREASING. AFTER A COOL START FRIDAY
MORNING...SOUNDINGS SUGGEST TEMPS WILL MODERATE TO NEAR NORMAL
VALUES IN THE AFTERNOON...GENERALLY UPPER 70S TO AROUND 80.
WE CONTINUE TO SEE SIGNIFICANT DIFFERENCES IN MODEL SOLUTIONS
BEGINNING FRIDAY NIGHT. THE LATEST GFS AND MOST OTHER MODELS ARE
PROGRESSIVE WITH THE AFOREMENTIONED SHORT WAVE THAT WILL BE CROSSING
THE OHIO RIVER VALLEY DURING THE DAYTIME FRIDAY...AND MOVE IT AND
ITS ATTENDANT SFC COLD FRONT ACROSS OUR AREA LATE ON SATURDAY
FOLLOWED BY HIGH PRESSURE BUILDING ACROSS THE AREA FROM THE NORTH
SATURDAY NIGHT AND SUNDAY. MEANWHILE...THE 0Z ECMWF CONTINUES TO
INDICATE A MUCH DIFFERENT SOLUTION THAT BASICALLY SLOWS THE
SHORTWAVE AND DELAYS THE FRONTAL PASSAGE UNTIL SUNDAY. THE GFS AND
OTHER PROGRESSIVE MODELS BASICALLY RESULT IN LOWER-IMPACT SHOWERS
AND TSTMS LATE FRIDAY AND SATURDAY FOLLOWED BY FAIR WEATHER ON
SUNDAY...WHILE THE 0Z ECMWF WOULD SUGGEST POTENTIALLY HIGHER-IMPACT
THUNDERSTORMS DURING THE DAYTIME SATURDAY AND POSSIBLY AGAIN ON
SUNDAY WITH THE FRONTAL PASSAGE. GIVEN THE LOWER-THAN-USUAL
CONFIDENCE...FOR NOW WILL MAKE FEW CHANGES TO CURRENT FORECAST...
WHICH SHOWS RAIN CHANCES INCREASING FRIDAY NIGHT AND CONTINUING INTO
SATURDAY NIGHT THEN DIMINISHING POPS ON SUNDAY. WORTH REPEATING THAT
IF THE TREND GOES TOWARD THE 0Z ECMWF...THE RISK FOR AN ACTIVE
THUNDERSTORM DAY ON SATURDAY INCREASES. TEMPS DURING THE WEEKEND
WILL BE HIGHLY DEPENDENT ON THE EVOLUTION OF THE PRECIP AND FRONTAL
TIMING. FOR NOW WILL CONTINUE ABOVE NORMAL TEMPS SATURDAY IN THE
PREFRONTAL ENVIRONMENT...THEN COOLER ON SUNDAY WITH EITHER THE FRONT
TO OUR SOUTH (GFS)...OR DUE TO PRECIP (ECMWF) KEEPING TEMPS DOWN.
MODELS COME INTO BETTER AGREEMENT EARLY NEXT WEEK...AND INDICATE A
RIDGE ACROSS OUR REGION ON MONDAY YIELDING FAIR WEATHER WITH TEMPS
10+ DEGREES ABOVE NORMAL...FOLLOWED BY A HIGHLY AMPLIFIED TROUGH
AFFECTING THE EASTERN PORTION OF THE COUNTRY DURING THE MIDDLE OF
THE WEEK. THIS TROUGH WILL PUSH A SFC COLD FRONT ACROSS OUR AREA ON
TUESDAY AND WILL START A MUCH COOLER TREND THAT WILL LINGER THROUGH
THE MIDDLE TO LATTER PART OF THE WEEK. EXPECT A CHANCE FOR SHOWERS
AND THUNDERSTORMS ALONG AND AHEAD OF TUESDAYS COLD FRONT...OTHERWISE
MUCH OF NEXT WEEK SHOULD BE DRY.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
A WEAK COLD FRONT WILL APPROACH FROM THE NORTH THIS EVENING...BUT
SHOWER AND THUNDERSTORM ACTIVITY ALONG THE FRONT HAS BEEN
WEAKENING SINCE 21Z AND SHOULD CONTINUE TO DO SO AS THE FRONT
SLIPS FURTHER SOUTH. CONFIDENCE IS INCREASING THAT WHILE A BRIEF
SHOWER MAY MAKE IT SOUTH TO KINT/KGSO/KRDU/KRWI BETWEEN 01Z-
03Z...CEILINGS AND VSBYS SHOULD REMAIN AT 4K FT OR ABOVE. ONCE THE
SHOWERS DISSIPATE OVERNIGHT...SOUTHWESTERLY WINDS WILL SLOWLY TURN
TO WESTERLY BY THURSDAY MORNING...THEN TO NORTHWESTERLY
THURSDAY..INCREASING TO NEAR 12KT WITH GUSTS IN THE 20-25KT RANGE.
OUTLOOK...
VFR CONDITIONS ARE EXPECTED THURSDAY NIGHT AND FRIDAY...WITH THE
NEXT CHANCE OF ADVERSE AVIATION CONDITIONS EXPECTED LATE FRIDAY
NIGHT INTO SATURDAY AS A SYSTEM IMPACT THE REGION FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BSD/WSS
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...NP
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1254 PM EDT TUE MAR 27 2012
.SYNOPSIS...
HIGH PRESSURE MOVES AWAY TONIGHT. A COLD FRONT MAY BRING STRONG
STORMS WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING. COLD HIGH
PRESSURE BUILDS IN THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE...NO SIGNIFICANT CHANGES MADE TO ONGOING FORECAST.
PREVIOUS DISCUSSION...TEMPERATURES ARE STEADILY DROPPING...ROUGHLY
2-3F/HR...AROUND THE CWA WITH SEVERAL ASOS LOCATIONS ALREADY
HOVERING AROUND THE 32 DEGREE MARK. STRONG CAA WHICH ACCELERATED
THE DROPPING TEMPERATURES EARLIER TONIGHT SHOULD ONLY BE FURTHER
ENHANCED BY RADIATIONAL COOLING OVER THE NEXT SEVERAL HOURS.
LATEST RUNS OF THE RUC HAVE 925MB FLOW SLACKENING AND TURNING MORE
PARALLEL TO THE ISOTHERMS. THIS WEAKENING OF THE LOW LEVEL FLOW
SHOULD ALLOW THE SHELTERED VALLEYS TO DECOUPLE AND COOL EVEN MORE
RAPIDLY. THIS IS CONFIRMED BY THE OBSERVATION TRENDS AT KI16 OVER
THE LAST SEVERAL HOURS. THERE IS CONCERN THAT OUR SOUTHERN WV MNT
COUNTIES JUST OUTSIDE OF THE ADVISORY COULD HAVE SOME FROST DEVELOP
IN THE DEEPER VALLEYS.
DAYTIME WARMING SHOULD BEGIN QUICKLY AFTER 13Z AS WE TRANSITION OVER
TO WAA. GOING A FEW DEGREES ABOVE GUIDANCE FOR ALL LOCATIONS FOR MAX
TEMPS. TEMPERATURES TONIGHT STAY WARM UNDER SUSTAINED WAA...STAYING
A COUPLE NOTCHES HIGHER...BUT SHOULD STILL HAVE A DIURNAL TEMP TREND.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
COLD FRONT IS OVERRUN BY WEAK UPPER LEVEL S/W TROF AS IT APPROACHES
WED. IT THEN PUSHES ON THROUGH WED NT AS A STRONGER S/W TROF DIGS
SE BEHIND IT. THE LEAD S/W WILL PROVIDE SOME ADDITIONAL SUPPORT FOR
CONVECTIVE PRECIPITATION AHEAD OF THE FRONT WED. THIS IS ALSO
LIKELY TO ENHANCE INSTABILITY...CONTRIBUTING TO AN AXIS OF UP TO 1.2
INCHES PW ALONG WITH 1.5-2.5 KJ/KG CAPE AND HELICITY NOW FCST TO
EXCEED 300 AHEAD OF THE FRONT. THIS AXIS SETS UP FROM EN KY NE
ALONG THE OHIO RIVER AND INTO CENTRAL WV DURING PEAK HEATING...WITH
VALUES DECREASING AS ONE MOVES NE ALONG THE AXIS INTO NE WV.
SPC NOW HIGHLIGHTS A SLIGHT RISK IN A NARROW AXIS FROM E KY INTO WV.
LIMITING FACTOR IS WEAK LOW LEVEL CONVERGENCE. UPPER SUPPORT IS
WEAK BUT IS FCST OUT AHEAD OF THE SURFACE FRONT. ADDED GUSTY WINDS
AND SMALL HAIL AND WILL CONTINUE HWO HIGHLIGHT BUT TRY TO LIMIT AREA
TO REFLECT SPC SLIGHT RISK.
COLD FRONT MOVES S THOUGH THE AREA WED NT...BRINGING AN END TO THE
SHOWERS AND THUNDERSTORMS FROM NW TO SE. MODEL DIFFERENCES CROP UP
FOR THU W/R STRENGTH OF COLD AIR ADVECTION AND AMOUNT OF STRATOCU AS
A RESULT. DID INCREASE CLOUD FCST SOMEWHAT WITH STRENGTHENING EARLY
SPRING SUN.
HIGH PRESSURE BUILDS IN THU NT...PRESENTING ANOTHER POSSIBILITY FOR
A FROST OR FREEZE.
TEMPERATURES WERE IN LIEN WITH GUIDANCE OR GUIDANCE BLENDS FOR THE
MOST PART...EXCEPT ON HIGHS THU. OPTED TO KEEP HIGHS CLOSER TO THE
HIGHER GUIDANCE FOR THE MOST PART. ADDED FROST FOR THU NT INTO FRI
MORNING.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
WENT WITH HPC THINKING FOR MUCH OF THE PERIOD. HOWEVER...STRAYED SOME
FROM THEIR THINKING AT THE END OF THE PERIOD...DUE TO HIGH
INCERTAINTY.
AN AREA OF LOW PRESSURE WILL PUSH EAST ACROSS THE AREA FRIDAY NIGHT
INTO SATURDAY...DRAGGING A WEAK COLD FRONT WITH IT. EXPECT SOME
SHOWERS AND STORMS FRIDAY NIGHT INTO SATURDAY NIGHT.
WEAK HIGH PRESSURE SHOULD BE IN CHARGE SUNDAY INTO SUNDAY NIGHT...
BEFORE THE COLD FRONT BEGINS TO MOVE BACK NORTH AS A WARM FRONT.
ANOTHER COLD FRONT IS THEN EXPECTED TO MOVE EAST LATE MONDAY
INTO TUESDAY. MODELS DIFFER WITH THE TIMING OF THE FRONT. BECAUSE
OF THIS UNCERTAINTY...HAVE KEPT POPS LOW FOR NOW.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL HOLD STEADY WITH LIGHT EAST FLOW AT THE SURFACE
SWITCHING TO THE SOUTH THIS AFTERNOON. WINDS INCREASE TONIGHT OUT
OF THE SOUTH WITH GUSTS NEARING 20KTS AT THE SURFACE...HIGHER
GUSTS POSSIBLE IN MNT AREAS. ALTHOUGH CLOUDS INCREASE THIS EVENING
AHEAD OF ADVANCING COLD FRONT...VFR CONDITIONS WILL PREVAIL
THROUGH THE PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: NONE
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z WEDNESDAY...
IFR CONDITIONS POSSIBLE IN SHOWERS AND THUNDERSTORMS WEDNESDAY INTO
WEDNESDAY EVENING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JSH/ARJ/50
NEAR TERM...50/TAX
SHORT TERM...TRM
LONG TERM...KTB
AVIATION...TAX
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1027 AM EDT TUE MAR 27 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE AREA THIS MORNING MOVES EAST THIS EVENING. A
COLD FRONT BRINGS STRONG STORMS WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING. COLD HIGH PRESSURE BUILDS IN THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE...NO SIGNIFICANT CHANGES MADE TO ONGOING FORECAST.
PREVIOUS DISCUSSION...TEMPERATURES ARE STEADILY DROPPING...ROUGHLY
2-3F/HR...AROUND THE CWA WITH SEVERAL ASOS LOCATIONS ALREADY
HOVERING AROUND THE 32 DEGREE MARK. STRONG CAA WHICH ACCELERATED
THE DROPPING TEMPERATURES EARLIER TONIGHT SHOULD ONLY BE FURTHER
ENHANCED BY RADIATIONAL COOLING OVER THE NEXT SEVERAL HOURS.
LATEST RUNS OF THE RUC HAVE 925MB FLOW SLACKENING AND TURNING MORE
PARALLEL TO THE ISOTHERMS. THIS WEAKENING OF THE LOW LEVEL FLOW
SHOULD ALLOW THE SHELTERED VALLEYS TO DECOUPLE AND COOL EVEN MORE
RAPIDLY. THIS IS CONFIRMED BY THE OBSERVATION TRENDS AT KI16 OVER
THE LAST SEVERAL HOURS. THERE IS CONCERN THAT OUR SOUTHERN WV MNT
COUNTIES JUST OUTSIDE OF THE ADVISORY COULD HAVE SOME FROST DEVELOP
IN THE DEEPER VALLEYS.
DAYTIME WARMING SHOULD BEGIN QUICKLY AFTER 13Z AS WE TRANSITION OVER
TO WAA. GOING A FEW DEGREES ABOVE GUIDANCE FOR ALL LOCATIONS FOR MAX
TEMPS. TEMPERATURES TONIGHT STAY WARM UNDER SUSTAINED WAA...STAYING
A COUPLE NOTCHES HIGHER...BUT SHOULD STILL HAVE A DIURNAL TEMP TREND.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
COLD FRONT IS OVERRUN BY WEAK UPPER LEVEL S/W TROF AS IT APPROACHES
WED. IT THEN PUSHES ON THROUGH WED NT AS A STRONGER S/W TROF DIGS
SE BEHIND IT. THE LEAD S/W WILL PROVIDE SOME ADDITIONAL SUPPORT FOR
CONVECTIVE PRECIPITATION AHEAD OF THE FRONT WED. THIS IS ALSO
LIKELY TO ENHANCE INSTABILITY...CONTRIBUTING TO AN AXIS OF UP TO 1.2
INCHES PW ALONG WITH 1.5-2.5 KJ/KG CAPE AND HELICITY NOW FCST TO
EXCEED 300 AHEAD OF THE FRONT. THIS AXIS SETS UP FROM EN KY NE
ALONG THE OHIO RIVER AND INTO CENTRAL WV DURING PEAK HEATING...WITH
VALUES DECREASING AS ONE MOVES NE ALONG THE AXIS INTO NE WV.
SPC NOW HIGHLIGHTS A SLIGHT RISK IN A NARROW AXIS FROM E KY INTO WV.
LIMITING FACTOR IS WEAK LOW LEVEL CONVERGENCE. UPPER SUPPORT IS
WEAK BUT IS FCST OUT AHEAD OF THE SURFACE FRONT. ADDED GUSTY WINDS
AND SMALL HAIL AND WILL CONTINUE HWO HIGHLIGHT BUT TRY TO LIMIT AREA
TO REFLECT SPC SLIGHT RISK.
COLD FRONT MOVES S THOUGH THE AREA WED NT...BRINGING AN END TO THE
SHOWERS AND THUNDERSTORMS FROM NW TO SE. MODEL DIFFERENCES CROP UP
FOR THU W/R STRENGTH OF COLD AIR ADVECTION AND AMOUNT OF STRATOCU AS
A RESULT. DID INCREASE CLOUD FCST SOMEWHAT WITH STRENGTHENING EARLY
SPRING SUN.
HIGH PRESSURE BUILDS IN THU NT...PRESENTING ANOTHER POSSIBILITY FOR
A FROST OR FREEZE.
TEMPERATURES WERE IN LIEN WITH GUIDANCE OR GUIDANCE BLENDS FOR THE
MOST PART...EXCEPT ON HIGHS THU. OPTED TO KEEP HIGHS CLOSER TO THE
HIGHER GUIDANCE FOR THE MOST PART. ADDED FROST FOR THU NT INTO FRI
MORNING.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
COOLER AND DRIER AIR AGAIN IN FULL CONTROL AT START OF THE PERIOD.
SOME FROST OR FREEZE MAY AGAIN OCCUR FOR THURSDAY NIGHT OR DAWN
FRIDAY.
STILL DRY FRIDAY INTO FRIDAY NIGHT. THERE COULD BE AN INITIAL
DISTURBANCE IN THE WNW FLOW AT MID LEVELS...INCREASING MOISTURE
HERE FRIDAY NIGHT. STILL FEEL THE MAIN FEATURE IS SATURDAY INTO
SATURDAY NIGHT. WITH MODEL INCONSISTENCY...HAVE NOT GONE LIKELY
POPS YET...BUT IF TRENDS HOLD...WILL PROBABLY END UP THAT WAY.
THEN HAVE POPS LOWERING AGAIN ON SUNDAY.
ANOTHER WEAK FEATURE IN THE WNW FLOW ALOFT...MAY APPROACH ON MONDAY.
FITTING THE LAST FEW DAYS OF THIS WARM MONTH OF MARCH HAVE ABOVE
NORMAL TEMPERATURES.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL HOLD STEADY WITH LIGHT EAST FLOW AT THE SURFACE
SWITCHING TO THE SOUTH THIS AFTERNOON. WINDS INCREASE TONIGHT OUT
OF THE SOUTH WITH GUSTS NEARING 20KTS AT THE SURFACE...HIGHER
GUSTS POSSIBLE IN MNT AREAS. ALTHOUGH CLOUDS INCREASE THIS EVENING
AHEAD OF ADVANCING COLD FRONT...VFR CONDITIONS WILL PREVAIL
THROUGH THE PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: NONE
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z WEDNESDAY...
IFR CONDITIONS POSSIBLE IN SHOWERS AND THUNDERSTORMS WEDNESDAY INTO
WEDNESDAY EVENING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/TAX
NEAR TERM...50/TAX
SHORT TERM...TRM
LONG TERM...KTB
AVIATION...TAX
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
641 AM EDT TUE MAR 27 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE AREA THIS MORNING MOVES EAST THIS EVENING. A
COLD FRONT BRINGS STRONG STORMS WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING. COLD HIGH PRESSURE BUILDS IN THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
TEMPERATURES ARE STEADILY DROPPING...ROUGHLY 2-3F/HR...AROUND THE
CWA WITH SEVERAL ASOS LOCATIONS ALREADY HOVERING AROUND THE 32
DEGREE MARK. STRONG CAA WHICH ACCELERATED THE DROPPING TEMPERATURES
EARLIER TONIGHT SHOULD ONLY BE FURTHER ENHANCED BY RADIATIONAL
COOLING OVER THE NEXT SEVERAL HOURS.
LATEST RUNS OF THE RUC HAVE 925MB FLOW SLACKENING AND TURNING MORE
PARALLEL TO THE ISOTHERMS. THIS WEAKENING OF THE LOW LEVEL FLOW
SHOULD ALLOW THE SHELTERED VALLEYS TO DECOUPLE AND COOL EVEN MORE
RAPIDLY. THIS IS CONFIRMED BY THE OBSERVATION TRENDS AT KI16 OVER
THE LAST SEVERAL HOURS. THERE IS CONCERN THAT OUR SOUTHERN WV MNT
COUNTIES JUST OUTSIDE OF THE ADVISORY COULD HAVE SOME FROST DEVELOP
IN THE DEEPER VALLEYS.
DAYTIME WARMING SHOULD BEGIN QUICKLY AFTER 13Z AS WE TRANSITION OVER
TO WAA. GOING A FEW DEGREES ABOVE GUIDANCE FOR ALL LOCATIONS FOR MAX
TEMPS. TEMPERATURES TONIGHT STAY WARM UNDER SUSTAINED WAA...STAYING
A COUPLE NOTCHES HIGHER...BUT SHOULD STILL HAVE A DIURNAL TEMP TREND.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
COLD FRONT IS OVERRUN BY WEAK UPPER LEVEL S/W TROF AS IT APPROACHES
WED. IT THEN PUSHES ON THROUGH WED NT AS A STRONGER S/W TROF DIGS
SE BEHIND IT. THE LEAD S/W WILL PROVIDE SOME ADDITIONAL SUPPORT FOR
CONVECTIVE PRECIPITATION AHEAD OF THE FRONT WED. THIS IS ALSO
LIKELY TO ENHANCE INSTABILITY...CONTRIBUTING TO AN AXIS OF UP TO 1.2
INCHES PW ALONG WITH 1.5-2.5 KJ/KG CAPE AND HELICITY NOW FCST TO
EXCEED 300 AHEAD OF THE FRONT. THIS AXIS SETS UP FROM EN KY NE
ALONG THE OHIO RIVER AND INTO CENTRAL WV DURING PEAK HEATING...WITH
VALUES DECREASING AS ONE MOVES NE ALONG THE AXIS INTO NE WV.
SPC NOW HIGHLIGHTS A SLIGHT RISK IN A NARROW AXIS FROM E KY INTO WV.
LIMITING FACTOR IS WEAK LOW LEVEL CONVERGENCE. UPPER SUPPORT IS
WEAK BUT IS FCST OUT AHEAD OF THE SURFACE FRONT. ADDED GUSTY WINDS
AND SMALL HAIL AND WILL CONTINUE HWO HIGHLIGHT BUT TRY TO LIMIT AREA
TO REFLECT SPC SLIGHT RISK.
COLD FRONT MOVES S THOUGH THE AREA WED NT...BRINGING AN END TO THE
SHOWERS AND THUNDERSTORMS FROM NW TO SE. MODEL DIFFERENCES CROP UP
FOR THU W/R STRENGTH OF COLD AIR ADVECTION AND AMOUNT OF STRATOCU AS
A RESULT. DID INCREASE CLOUD FCST SOMEWHAT WITH STRENGTHENING EARLY
SPRING SUN.
HIGH PRESSURE BUILDS IN THU NT...PRESENTING ANOTHER POSSIBILITY FOR
A FROST OR FREEZE.
TEMPERATURES WERE IN LIEN WITH GUIDANCE OR GUIDANCE BLENDS FOR THE
MOST PART...EXCEPT ON HIGHS THU. OPTED TO KEEP HIGHS CLOSER TO THE
HIGHER GUIDANCE FOR THE MOST PART. ADDED FROST FOR THU NT INTO FRI
MORNING.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
COOLER AND DRIER AIR AGAIN IN FULL CONTROL AT START OF THE PERIOD.
SOME FROST OR FREEZE MAY AGAIN OCCUR FOR THURSDAY NIGHT OR DAWN
FRIDAY.
STILL DRY FRIDAY INTO FRIDAY NIGHT. THERE COULD BE AN INITIAL
DISTURBANCE IN THE WNW FLOW AT MID LEVELS...INCREASING MOISTURE
HERE FRIDAY NIGHT. STILL FEEL THE MAIN FEATURE IS SATURDAY INTO
SATURDAY NIGHT. WITH MODEL INCONSISTENCY...HAVE NOT GONE LIKELY
POPS YET...BUT IF TRENDS HOLD...WILL PROBABLY END UP THAT WAY.
THEN HAVE POPS LOWERING AGAIN ON SUNDAY.
ANOTHER WEAK FEATURE IN THE WNW FLOW ALOFT...MAY APPROACH ON MONDAY.
FITTING THE LAST FEW DAYS OF THIS WARM MONTH OF MARCH HAVE ABOVE
NORMAL TEMPERATURES.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL HOLD STEADY WITH LIGHT EAST FLOW AT THE SURFACE
SWITCHING TO THE SOUTH THIS AFTERNOON. WINDS INCREASE TONIGHT OUT
OF THE SOUTH WITH GUSTS NEARING 20KTS AT THE SURFACE...HIGHER
GUSTS POSSIBLE IN MNT AREAS. ALTHOUGH CLOUDS INCREASE THIS EVENING
AHEAD OF ADVANCING COLD FRONT...VFR CONDITIONS WILL PREVAIL
THROUGH THE PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: NONE
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z WEDNESDAY...
IFR CONDITIONS POSSIBLE IN SHOWERS AND THUNDERSTORMS WEDNESDAY INTO
WEDNESDAY EVENING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR WVZ006>011-
014>020-027>032.
FROST ADVISORY UNTIL 10 AM EDT THIS MORNING FOR WVZ005-013-
024>026.
OH...FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR OHZ066-067-075-
076-083>087.
KY...FROST ADVISORY UNTIL 10 AM EDT THIS MORNING FOR KYZ101>103-105.
VA...NONE.
&&
$$
SYNOPSIS...TRM/TAX
NEAR TERM...TAX
SHORT TERM...TRM
LONG TERM...KTB
AVIATION...TAX
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
414 AM EDT TUE MAR 27 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE AREA THIS MORNING MOVES EAST THIS EVENING. A
COLD FRONT BRINGS STRONG STORMS WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING. COLD HIGH PRESSURE BUILDS IN THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
TEMPERATURES ARE STEADILY DROPPING...ROUGHLY 2-3F/HR...AROUND THE
CWA WITH SEVERAL ASOS LOCATIONS ALREADY HOVERING AROUND THE 32
DEGREE MARK. STRONG CAA WHICH ACCELERATED THE DROPPING TEMPERATURES
EARLIER TONIGHT SHOULD ONLY BE FURTHER ENHANCED BY RADIATIONAL
COOLING OVER THE NEXT SEVERAL HOURS.
LATEST RUNS OF THE RUC HAVE 925MB FLOW SLACKENING AND TURNING MORE
PARALLEL TO THE ISOTHERMS. THIS WEAKENING OF THE LOW LEVEL FLOW
SHOULD ALLOW THE SHELTERED VALLEYS TO DECOUPLE AND COOL EVEN MORE
RAPIDLY. THIS IS CONFIRMED BY THE OBSERVATION TRENDS AT KI16 OVER
THE LAST SEVERAL HOURS. THERE IS CONCERN THAT OUR SOUTHERN WV MNT
COUNTIES JUST OUTSIDE OF THE ADVISORY COULD HAVE SOME FROST DEVELOP
IN THE DEEPER VALLEYS.
DAYTIME WARMING SHOULD BEGIN QUICKLY AFTER 13Z AS WE TRANSITION OVER
TO WAA. GOING A FEW DEGREES ABOVE GUIDANCE FOR ALL LOCATIONS FOR MAX
TEMPS. TEMPERATURES TONIGHT STAY WARM UNDER SUSTAINED WAA...STAYING
A COUPLE NOTCHES HIGHER...BUT SHOULD STILL HAVE A DIURNAL TEMP TREND.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
COLD FRONT IS OVERRUN BY WEAK UPPER LEVEL S/W TROF AS IT APPROACHES
WED. IT THEN PUSHES ON THROUGH WED NT AS A STRONGER S/W TROF DIGS
SE BEHIND IT. THE LEAD S/W WILL PROVIDE SOME ADDITIONAL SUPPORT FOR
CONVECTIVE PRECIPITATION AHEAD OF THE FRONT WED. THIS IS ALSO
LIKELY TO ENHANCE INSTABILITY...CONTRIBUTING TO AN AXIS OF UP TO 1.2
INCHES PW ALONG WITH 1.5-2.5 KJ/KG CAPE AND HELICITY NOW FCST TO
EXCEED 300 AHEAD OF THE FRONT. THIS AXIS SETS UP FROM EN KY NE
ALONG THE OHIO RIVER AND INTO CENTRAL WV DURING PEAK HEATING...WITH
VALUES DECREASING AS ONE MOVES NE ALONG THE AXIS INTO NE WV.
SPC NOW HIGHLIGHTS A SLIGHT RISK IN A NARROW AXIS FROM E KY INTO WV.
LIMITING FACTOR IS WEAK LOW LEVEL CONVERGENCE. UPPER SUPPORT IS
WEAK BUT IS FCST OUT AHEAD OF THE SURFACE FRONT. ADDED GUSTY WINDS
AND SMALL HAIL AND WILL CONTINUE HWO HIGHLIGHT BUT TRY TO LIMIT AREA
TO REFLECT SPC SLIGHT RISK.
COLD FRONT MOVES S THOUGH THE AREA WED NT...BRINGING AN END TO THE
SHOWERS AND THUNDERSTORMS FROM NW TO SE. MODEL DIFFERENCES CROP UP
FOR THU W/R STRENGTH OF COLD AIR ADVECTION AND AMOUNT OF STRATOCU AS
A RESULT. DID INCREASE CLOUD FCST SOMEWHAT WITH STRENGTHENING EARLY
SPRING SUN.
HIGH PRESSURE BUILDS IN THU NT...PRESENTING ANOTHER POSSIBILITY FOR
A FROST OR FREEZE.
TEMPERATURES WERE IN LIEN WITH GUIDANCE OR GUIDANCE BLENDS FOR THE
MOST PART...EXCEPT ON HIGHS THU. OPTED TO KEEP HIGHS CLOSER TO THE
HIGHER GUIDANCE FOR THE MOST PART. ADDED FROST FOR THU NT INTO FRI
MORNING.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
COOLER AND DRIER AIR AGAIN IN FULL CONTROL AT START OF THE PERIOD.
SOME FROST OR FREEZE MAY AGAIN OCCUR FOR THURSDAY NIGHT OR DAWN
FRIDAY.
STILL DRY FRIDAY INTO FRIDAY NIGHT. THERE COULD BE AN INITIAL
DISTURBANCE IN THE WNW FLOW AT MID LEVELS...INCREASING MOISTURE
HERE FRIDAY NIGHT. STILL FEEL THE MAIN FEATURE IS SATURDAY INTO
SATURDAY NIGHT. WITH MODEL INCONSISTENCY...HAVE NOT GONE LIKELY
POPS YET...BUT IF TRENDS HOLD...WILL PROBABLY END UP THAT WAY.
THEN HAVE POPS LOWERING AGAIN ON SUNDAY.
ANOTHER WEAK FEATURE IN THE WNW FLOW ALOFT...MAY APPROACH ON MONDAY.
FITTING THE LAST FEW DAYS OF THIS WARM MONTH OF MARCH HAVE ABOVE
NORMAL TEMPERATURES.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
EXPECT VFR CONDITIONS THROUGH THE TAF PERIOD WITH LIGHT NORTH OR
NORTHEAST FLOW AT THE SURFACE SWITCHING TO THE EAST TUES AFTERNOON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: NONE
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 03/27/12
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z WEDNESDAY...
IFR CONDITIONS POSSIBLE IN SHOWERS AND THUNDERSTORMS WEDNESDAY INTO
WEDNESDAY EVENING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR WVZ006>011-
014>020-027>032.
FROST ADVISORY UNTIL 10 AM EDT THIS MORNING FOR WVZ005-013-
024>026.
OH...FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR OHZ066-067-075-
076-083>087.
KY...FROST ADVISORY UNTIL 10 AM EDT THIS MORNING FOR KYZ101>103-105.
VA...NONE.
&&
$$
SYNOPSIS...TRM/TAX
NEAR TERM...TAX
SHORT TERM...TRM
LONG TERM...KTB
AVIATION...TAX
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
435 PM EDT TUE MAR 27 2012
.SYNOPSIS...
DRY SURFACE HIGH WILL LINGER OVER THE AREA TONIGHT THROUGH
WEDNESDAY. A WEAK COLD FRONT WILL THEN SWEEP ACROSS THE REGION EARLY
THURSDAY FOLLOWED BY ANOTHER RIDGE OF DRY HIGH PRESSURE MOVING BACK
IN BEHIND THE FRONT ON FRIDAY. A SERIES OF UPPER SHORTWAVE SYSTEMS
WILL AFFECT OUR WEATHER THIS WEEKEND.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 430 PM EDT...GRIDS ARE IN GOOD SHAPE WITH ONLY SOME THIN CI
WHICH IS RESULTING IN VERY LITTLE OPAQUE SKY COVER. MINOR TWEAKS
WERE MADE TO TEMPS AND DEWPOINTS. A TREND TOWARD SLIGHTLY HIGH
DEWPOINTS IS BECOMING ESTABLISHED OVER THE UPSTATE AND NE GA...AND
THESE AREAS MAY NEED TO HAVE TD/S ADJUSTED UP AS THE EVENING
PROGRESSES.
PREVIOUS DISCUSSIONS...
SKY COVER ACROSS THE CWA SHOULD REMAIN CLEAR THROUGH THE EVENING
HOURS...ONLY A FEW CONTRAILS. LATEST SATELLITE LOOP INDICATED A
GATHERING AREA OF LOW CLOUDS ALONG THE GA COAST. A FEW MESOSCALE
MODELS INDICATE THAT THE MOISTURE WILL ADVECT NW
OVERNIGHT...REACHING THE CAROLINA PIEDMONT AND UPPER SAVANNAH RIVER
VALLEY LATE TONIGHT INTO WEDNESDAY MORNING. HOWEVER...RECENT RUNS OF
THE RUC AND LAMP MODELS HAVE BEEN BACKING AWAY FROM THIS
SOLUTION...KEEPING THE MOISTURE FURTHER SOUTH ACROSS GA. I WILL USE
A COMPROMISE IN THE FORECAST...INDICATING PARTLY CLOUDY CONDITIONS
BY SUNRISE. LOW TEMPERATURES ARE EXPECTED TO RANGE FROM THE LOW 50S
ACROSS THE UPPER SAVANNAH RIVER VALLEY TO THE L40S ACROSS THE MTN
VALLEYS AND ALONG AND NORTH OF I-40.
WEDNESDAY...A SLOW MOVING COLD FRONT...ORIENTED SW TO NE...WILL
SLOWLY SLIDE SOUTHEAST ACROSS KY AND WV DURING THE AFTERNOON. AS THE
FRONT APPROACHES...HIGH PRESSURE WILL REMAIN CENTERED NEAR THE FL
PANHANDLE...PLACING THE CWA WITHIN A 4-6 MB PRESSURE GRADIENT.
SOUTHWEST WINDS SHOULD INCREASE THROUGH THE AFTERNOON INTO THE TEENS
GUSTING INTO THE L20S. TEMPERATURES SHOULD STEADILY WARM THROUGH THE
DAY...PEAKING IN THE MID TO U70S EAST OF THE MTNS AND WITHIN THE MTN
VALLEYS. HOWEVER...DEWPOINTS WILL REMAIN AROUND 50 DEGREES AND RH
VALUES SHOULD FALL BELOW 40 PERCENT. FORECAST SOUNDINGS INDICATE
THAT H85 FLOW WILL BECOME NEARLY DUE WEST WITH SPEEDS AROUND 30
KTS...RESULTING IN WIDESPREAD DOWNSLOPE FLOW ACROSS THE FOOTHILLS
AND PIEDMONT. CIN VALUES MAY CONTINUE TO RANGE ABOVE 40 J/KG EAST OF
THE MTNS THROUGH THE AFTERNOON. HOWEVER...THE COMBINATION OF UPSLOPE
FLOW...POSSIBLE OUTFLOW BOUNDARY...AND MODERATE INSTABILITY SHOULD
SUPPORT SCT SHRA/TSRA ACROSS THE TN BORDER COUNTIES BY LATE
AFTERNOON...LITTLE TO NO CHC EAST.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 255 PM TUESDAY...WEAK SHORT WAVE MOVES NORTH OF THE AREA
WEDNESDAY NIGHT. THE WAVE PUSHES A WEAK COLD FRONT SOUTH ACROSS THE
AREA BY EARLY THURSDAY. BEST QG FORCING REMAINS WELL TO OUR NORTH.
HOWEVER...THERE IS SOME WEAK UPPER DIVERGENCE ACROSS THE REGION LATE
WEDNESDAY NIGHT. DEEP MOISTURE REMAINS LIMITED WITH THE FRONT WITH
LITTLE IN THE WAY OF LOW LEVEL INFLOW DUE TO W TO SW WINDS AHEAD OF
THE FRONT. BEST LOW LEVEL CONVERGENCE WILL BE OVER THE MTNS AS WELL.
CONTINUED THE TREND OF HIGH CHC POP FOR THE WRN MTNS TAPERING OFF TO
LOW CHC BLUE RIDGE. ALLOWED A BRIEF PERIOD OF SLIGHT CHC ACROSS THE
ENTIRE CWFA DURING THE EVENING GIVEN THE ELEVATED INSTABILITY AND
SOME WEAK FORCING. THAT SAID...PRECIP CHC OVER THE PIEDMONT IS LOW.
STILL CANNOT RULE OUT AN ISOLATED SVR STORM OVER THE MTNS AND NRN
TIER GIVEN THE MODERATE INSTABILITY AND DECENT SHEAR. ANY CONVECTION
WILL QUICKLY END LATE WED NITE OR EARLY THU MORN WITH CLEARING
SKIES. HIGH PRESSURE BUILDS IN THU NITE THEN SLIDES EAST FRI AS A
WEAK WARM FRONT SLIDES BY TO OUR NW. THIS AND THE DEVELOPING SWLY
FLOW SHUD BE ENUF FOR AN INCREASE IN CLOUDS. HOWEVER...NO PRECIP
EXPECTED FOR NOW. LOWS 10 TO 15 DEGREES ABOVE NORMAL WED NITE FALL
TO 5 TO 10 ABOVE THU NITE. HIGHS THU 10 TO 15 DEGREES ABOVE NORMAL
IN THE CLEARING SKIES AND DEVELOPING DOWNSLOPE FLOW REMAIN NEARLY
STEADY OVER THE MTNS FRI AND FALL AROUND 5 DEGREES ELSEWHERE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 230 PM TUESDAY...THE LATEST MODELS ARE IN FAIR AGREEMENT WITH
A SERIES OF UPPER SHORTWAVE SYSTEMS MOVING ACROSS THE REGION THIS
WEEKEND WITH ANOTHER FRONTAL SYSTEM APPROACHING THE AREA FROM THE
NORTHWEST BY NEXT TUESDAY. LATE FRIDAY AND SATURDAY...A WEAK UPPER
SHORTWAVE TROUGH OVER THE GREAT LAKES FRIDAY WILL MOVE SE ACROSS THE
REGION SATURDAY FOLLOWED BY ANOTHER SOUTHERN STREAM UPPER SHORTWAVE
MOVING THROUGH ON SUNDAY. THE COMBINATION OF DIURNAL INSTABILITY AND
SOME DEGREE OF UPPER FORCING WILL SUPPORT FOR THE DEVELOPMENT OF
THUNDERSTORMS ACROSS MUCH OF THE REGION. SO I KEPT POPS IN THE 30S
SAT/SUN. MONDAY AND TUESDAY...AN UPPER LOW OVER THE DAKOTAS MONDAY
WILL MOVE SOUTHEAST ACROSS IN/KY...PUSHING A COLD FRONT SE INTO OUR
FORECAST AREA BY LATE MON/EARLY TUESDAY. HOWEVER DUE TO THE
UNCERTAINTY...I MENTIONED POPS ONLY IN THE 20S FOR MON NIGHT /TUES.
DAYTIME TEMPERATURES WILL REMAIN IN THE UPPER 70S AND SOME 80S
THROUGH OUT THE EXTENDED FORECAST PERIOD.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...LATEST SATELLITE IMAGES INDICATE MOSTLY
CLEAR CONDITIONS ACROSS THE WESTERN CAROLINAS...ONLY A FEW CONTRAILS
ACROSS THE PIEDMONT OF NC. AREAS ACROSS THE GA COAST HAS BEEN
GATHERING MVFR CLOUDS THROUGH THE DAY. NAM GUIDANCE INDICATES THAT
THE GA COASTAL MOISTURE WILL LIFT ACROSS THE PIEDMONT AND UPPER
SAVANNAH RIVER VALLEY DURING THE PRE DAWN HOURS. HOWEVER...LATEST
LAV GUIDANCE AND RUC GUIDANCE INDICATES LESS POTENTIAL FOR LOW
CLOUDS LATE TONIGHT. I WILL INDICATE A SHORT PERIOD OF MVFR CEILINGS
AT KAND BETWEEN 12Z TO 14Z. OTHERWISE...EXPECT CONDITIONS ACROSS THE
TERMINALS TO REMAIN VFR WITH LIGHT SE TO SW WINDS THROUGH THE PERIOD.
OUTLOOK...HIGH PRESSURE WILL KEEP VFR CONDITIONS ACROSS THE AREA
THROUGH WEDNESDAY. ANOTHER COLD FRONT IS EXPECTED TO MOVE IN FROM
THE NW EARLY THURSDAY WITH SCATTERED SHOWERS AND THUNDERSTORMS OVER
THE NC MOUNTAINS RESULTING IN POSSIBLE CIG RESTRICTIONS LATE WED AND
INTO THURS. HIGH PRESSURE WILL BUILD BACK INTO THE AREA BEHIND THE
COLD FRONT ON FRIDAY.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...MCAVOY/NED
SHORT TERM...RWH
LONG TERM...JOH
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
342 PM EDT TUE MAR 27 2012
.SYNOPSIS...
DRY SURFACE HIGH WILL LINGER OVER THE AREA TONIGHT THROUGH
WEDNESDAY. A WEAK COLD FRONT WILL THEN SWEEP ACROSS THE REGION EARLY
THURSDAY FOLLOWED BY ANOTHER RIDGE OF DRY HIGH PRESSURE MOVING BACK
IN BEHIND THE FRONT ON FRIDAY. A SERIES OF UPPER SHORTWAVE SYSTEMS
WILL AFFECT OUR WEATHER THIS WEEKEND.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
SKY COVER ACROSS THE CWA SHOULD REMAIN CLEAR THROUGH THE EVENING
HOURS...ONLY A FEW CONTRAILS. LATEST SATELLITE LOOP INDICATED A
GATHERING AREA OF LOW CLOUDS ALONG THE GA COAST. A FEW MESOSCALE
MODELS INDICATE THAT THE MOISTURE WILL ADVECT NW
OVERNIGHT...REACHING THE CAROLINA PIEDMONT AND UPPER SAVANNAH RIVER
VALLEY LATE TONIGHT INTO WEDNESDAY MORNING. HOWEVER...RECENT RUNS OF
THE RUC AND LAMP MODELS HAVE BEEN BACKING AWAY FROM THIS
SOLUTION...KEEPING THE MOISTURE FURTHER SOUTH ACROSS GA. I WILL USE
A COMPROMISE IN THE FORECAST...INDICATING PARTLY CLOUDY CONDITIONS
BY SUNRISE. LOW TEMPERATURES ARE EXPECTED TO RANGE FROM THE LOW 50S
ACROSS THE UPPER SAVANNAH RIVER VALLEY TO THE L40S ACROSS THE MTN
VALLEYS AND ALONG AND NORTH OF I-40.
WEDNESDAY...A SLOW MOVING COLD FRONT...ORIENTED SW TO NE...WILL
SLOWLY SLIDE SOUTHEAST ACROSS KY AND WV DURING THE AFTERNOON. AS THE
FRONT APPROACHES...HIGH PRESSURE WILL REMAIN CENTERED NEAR THE FL
PANHANDLE...PLACING THE CWA WITHIN A 4-6 MB PRESSURE GRADIENT.
SOUTHWEST WINDS SHOULD INCREASE THROUGH THE AFTERNOON INTO THE TEENS
GUSTING INTO THE L20S. TEMPERATURES SHOULD STEADILY WARM THROUGH THE
DAY...PEAKING IN THE MID TO U70S EAST OF THE MTNS AND WITHIN THE MTN
VALLEYS. HOWEVER...DEWPOINTS WILL REMAIN AROUND 50 DEGREES AND RH
VALUES SHOULD FALL BELOW 40 PERCENT. FORECAST SOUNDINGS INDICATE
THAT H85 FLOW WILL BECOME NEARLY DUE WEST WITH SPEEDS AROUND 30
KTS...RESULTING IN WIDESPREAD DOWNSLOPE FLOW ACROSS THE FOOTHILLS
AND PIEDMONT. CIN VALUES MAY CONTINUE TO RANGE ABOVE 40 J/KG EAST OF
THE MTNS THROUGH THE AFTERNOON. HOWEVER...THE COMBINATION OF UPSLOPE
FLOW...POSSIBLE OUTFLOW BOUNDARY...AND MODERATE INSTABILITY SHOULD
SUPPORT SCT SHRA/TSRA ACROSS THE TN BORDER COUNTIES BY LATE
AFTERNOON...LITTLE TO NO CHC EAST.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 255 PM TUESDAY...WEAK SHORT WAVE MOVES NORTH OF THE AREA
WEDNESDAY NIGHT. THE WAVE PUSHES A WEAK COLD FRONT SOUTH ACROSS THE
AREA BY EARLY THURSDAY. BEST QG FORCING REMAINS WELL TO OUR NORTH.
HOWEVER...THERE IS SOME WEAK UPPER DIVERGENCE ACROSS THE REGION LATE
WEDNESDAY NIGHT. DEEP MOISTURE REMAINS LIMITED WITH THE FRONT WITH
LITTLE IN THE WAY OF LOW LEVEL INFLOW DUE TO W TO SW WINDS AHEAD OF
THE FRONT. BEST LOW LEVEL CONVERGENCE WILL BE OVER THE MTNS AS WELL.
CONTINUED THE TREND OF HIGH CHC POP FOR THE WRN MTNS TAPERING OFF TO
LOW CHC BLUE RIDGE. ALLOWED A BRIEF PERIOD OF SLIGHT CHC ACROSS THE
ENTIRE CWFA DURING THE EVENING GIVEN THE ELEVATED INSTABILITY AND
SOME WEAK FORCING. THAT SAID...PRECIP CHC OVER THE PIEDMONT IS LOW.
STILL CANNOT RULE OUT AN ISOLATED SVR STORM OVER THE MTNS AND NRN
TIER GIVEN THE MODERATE INSTABILITY AND DECENT SHEAR. ANY CONVECTION
WILL QUICKLY END LATE WED NITE OR EARLY THU MORN WITH CLEARING
SKIES. HIGH PRESSURE BUILDS IN THU NITE THEN SLIDES EAST FRI AS A
WEAK WARM FRONT SLIDES BY TO OUR NW. THIS AND THE DEVELOPING SWLY
FLOW SHUD BE ENUF FOR AN INCREASE IN CLOUDS. HOWEVER...NO PRECIP
EXPECTED FOR NOW. LOWS 10 TO 15 DEGREES ABOVE NORMAL WED NITE FALL
TO 5 TO 10 ABOVE THU NITE. HIGHS THU 10 TO 15 DEGREES ABOVE NORMAL
IN THE CLEARING SKIES AND DEVELOPING DOWNSLOPE FLOW REMAIN NEARLY
STEADY OVER THE MTNS FRI AND FALL AROUND 5 DEGREES ELSEWHERE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 230 PM TUESDAY...THE LATEST MODELS ARE IN FAIR AGREEMENT WITH
A SERIES OF UPPER SHORTWAVE SYSTEMS MOVING ACROSS THE REGION THIS
WEEKEND WITH ANOTHER FRONTAL SYSTEM APPROACHING THE AREA FROM THE
NORTHWEST BY NEXT TUESDAY. LATE FRIDAY AND SATURDAY...A WEAK UPPER
SHORTWAVE TROUGH OVER THE GREAT LAKES FRIDAY WILL MOVE SE ACROSS THE
REGION SATURDAY FOLLOWED BY ANOTHER SOUTHERN STREAM UPPER SHORTWAVE
MOVING THROUGH ON SUNDAY. THE COMBINATION OF DIURNAL INSTABILITY AND
SOME DEGREE OF UPPER FORCING WILL SUPPORT FOR THE DEVELOPMENT OF
THUNDERSTORMS ACROSS MUCH OF THE REGION. SO I KEPT POPS IN THE 30S
SAT/SUN. MONDAY AND TUESDAY...AN UPPER LOW OVER THE DAKOTAS MONDAY
WILL MOVE SOUTHEAST ACROSS IN/KY...PUSHING A COLD FRONT SE INTO OUR
FORECAST AREA BY LATE MON/EARLY TUESDAY. HOWEVER DUE TO THE
UNCERTAINTY...I MENTIONED POPS ONLY IN THE 20S FOR MON NIGHT /TUES.
DAYTIME TEMPERATURES WILL REMAIN IN THE UPPER 70S AND SOME 80S
THROUGH OUT THE EXTENDED FORECAST PERIOD.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...LATEST SATELLITE IMAGES INDICATE MOSTLY
CLEAR CONDITIONS ACROSS THE WESTERN CAROLINAS...ONLY A FEW CONTRAILS
ACROSS THE PIEDMONT OF NC. AREAS ACROSS THE GA COAST HAS BEEN
GATHERING MVFR CLOUDS THROUGH THE DAY. NAM GUIDANCE INDICATES THAT
THE GA COASTAL MOISTURE WILL LIFT ACROSS THE PIEDMONT AND UPPER
SAVANNAH RIVER VALLEY DURING THE PRE DAWN HOURS. HOWEVER...LATEST
LAV GUIDANCE AND RUC GUIDANCE INDICATES LESS POTENTIAL FOR LOW
CLOUDS LATE TONIGHT. I WILL INDICATE A SHORT PERIOD OF MVFR CEILINGS
AT KAND BETWEEN 12Z TO 14Z. OTHERWISE...EXPECT CONDITIONS ACROSS THE
TERMINALS TO REMAIN VFR WITH LIGHT SE TO SW WINDS THROUGH THE PERIOD.
OUTLOOK...HIGH PRESSURE WILL KEEP VFR CONDITIONS ACROSS THE AREA
THROUGH WEDNESDAY. ANOTHER COLD FRONT IS EXPECTED TO MOVE IN FROM
THE NW EARLY THURSDAY WITH SCATTERED SHOWERS AND THUNDERSTORMS OVER
THE NC MOUNTAINS RESULTING IN POSSIBLE CIG RESTRICTIONS LATE WED AND
INTO THURS. HIGH PRESSURE WILL BUILD BACK INTO THE AREA BEHIND THE
COLD FRONT ON FRIDAY.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...NED
SHORT TERM...RWH
LONG TERM...JOH
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
327 PM EDT TUE MAR 27 2012
.SYNOPSIS...
DRY SURFACE HIGH WILL LINGER OVER THE AREA TONIGHT THROUGH
WEDNESDAY. A WEAK COLD FRONT WILL THEN SWEEP ACROSS THE REGION EARLY
THURSDAY FOLLOWED BY ANOTHER RIDGE OF DRY HIGH PRESSURE MOVING BACK
IN BEHIND THE FRONT ON FRIDAY. A SERIES OF UPPER SHORTWAVE SYSTEMS
WILL AFFECT OUR WEATHER THIS WEEKEND.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
SKY COVER ACROSS THE CWA SHOULD REMAIN CLEAR THROUGH THE EVENING
HOURS...ONLY A FEW CONTRAILS. LATEST SATELLITE LOOP INDICATED A
GATHERING AREA OF LOW CLOUDS ALONG THE GA COAST. A FEW MESOSCALE
MODELS INDICATE THAT THE MOISTURE WILL ADVECT NW
OVERNIGHT...REACHING THE CAROLINA PIEDMONT AND UPPER SAVANNAH RIVER
VALLEY LATE TONIGHT INTO WEDNESDAY MORNING. HOWEVER...RECENT RUNS OF
THE RUC AND LAMP MODELS HAVE BEEN BACKING AWAY FROM THIS
SOLUTION...KEEPING THE MOISTURE FURTHER SOUTH ACROSS GA. I WILL USE
A COMPROMISE IN THE FORECAST...INDICATING PARTLY CLOUDY CONDITIONS
BY SUNRISE. LOW TEMPERATURES ARE EXPECTED TO RANGE FROM THE LOW 50S
ACROSS THE UPPER SAVANNAH RIVER VALLEY TO THE L40S ACROSS THE MTN
VALLEYS AND ALONG AND NORTH OF I-40.
WEDNESDAY...A SLOW MOVING COLD FRONT...ORIENTED SW TO NE...WILL
SLOWLY SLIDE SOUTHEAST ACROSS KY AND WV DURING THE AFTERNOON. AS THE
FRONT APPROACHES...HIGH PRESSURE WILL REMAIN CENTERED NEAR THE FL
PANHANDLE...PLACING THE CWA WITHIN A 4-6 MB PRESSURE GRADIENT.
SOUTHWEST WINDS SHOULD INCREASE THROUGH THE AFTERNOON INTO THE TEENS
GUSTING INTO THE L20S. TEMPERATURES SHOULD STEADILY WARM THROUGH THE
DAY...PEAKING IN THE MID TO U70S EAST OF THE MTNS AND WITHIN THE MTN
VALLEYS. HOWEVER...DEWPOINTS WILL REMAIN AROUND 50 DEGREES AND RH
VALUES SHOULD FALL BELOW 40 PERCENT. FORECAST SOUNDINGS INDICATE
THAT H85 FLOW WILL BECOME NEARLY DUE WEST WITH SPEEDS AROUND 30
KTS...RESULTING IN WIDESPREAD DOWNSLOPE FLOW ACROSS THE FOOTHILLS
AND PIEDMONT. CIN VALUES MAY CONTINUE TO RANGE ABOVE 40 J/KG EAST OF
THE MTNS THROUGH THE AFTERNOON. HOWEVER...THE COMBINATION OF UPSLOPE
FLOW...POSSIBLE OUTFLOW BOUNDARY...AND MODERATE INSTABILITY SHOULD
SUPPORT SCT SHRA/TSRA ACROSS THE TN BORDER COUNTIES BY LATE
AFTERNOON...LITTLE TO NO CHC EAST.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 255 PM TUESDAY...WEAK SHORT WAVE MOVES NORTH OF THE AREA
WEDNESDAY NIGHT. THE WAVE PUSHES A WEAK COLD FRONT SOUTH ACROSS THE
AREA BY EARLY THURSDAY. BEST QG FORCING REMAINS WELL TO OUR NORTH.
HOWEVER...THERE IS SOME WEAK UPPER DIVERGENCE ACROSS THE REGION LATE
WEDNESDAY NIGHT. DEEP MOISTURE REMAINS LIMITED WITH THE FRONT WITH
LITTLE IN THE WAY OF LOW LEVEL INFLOW DUE TO W TO SW WINDS AHEAD OF
THE FRONT. BEST LOW LEVEL CONVERGENCE WILL BE OVER THE MTNS AS WELL.
CONTINUED THE TREND OF HIGH CHC POP FOR THE WRN MTNS TAPERING OFF TO
LOW CHC BLUE RIDGE. ALLOWED A BRIEF PERIOD OF SLIGHT CHC ACROSS THE
ENTIRE CWFA DURING THE EVENING GIVEN THE ELEVATED INSTABILITY AND
SOME WEAK FORCING. THAT SAID...PRECIP CHC OVER THE PIEDMONT IS LOW.
STILL CANNOT RULE OUT AN ISOLATED SVR STORM OVER THE MTNS AND NRN
TIER GIVEN THE MODERATE INSTABILITY AND DECENT SHEAR. ANY CONVECTION
WILL QUICKLY END LATE WED NITE OR EARLY THU MORN WITH CLEARING
SKIES. HIGH PRESSURE BUILDS IN THU NITE THEN SLIDES EAST FRI AS A
WEAK WARM FRONT SLIDES BY TO OUR NW. THIS AND THE DEVELOPING SWLY
FLOW SHUD BE ENUF FOR AN INCREASE IN CLOUDS. HOWEVER...NO PRECIP
EXPECTED FOR NOW. LOWS 10 TO 15 DEGREES ABOVE NORMAL WED NITE FALL
TO 5 TO 10 ABOVE THU NITE. HIGHS THU 10 TO 15 DEGREES ABOVE NORMAL
IN THE CLEARING SKIES AND DEVELOPING DOWNSLOPE FLOW REMAIN NEARLY
STEADY OVER THE MTNS FRI AND FALL AROUND 5 DEGREES ELSEWHERE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 230 PM TUESDAY...THE LATEST MODELS ARE IN FAIR AGREEMENT WITH
A SERIES OF UPPER SHORTWAVE SYSTEMS MOVING ACROSS THE REGION THIS
WEEKEND WITH ANOTHER FRONTAL SYSTEM APPROACHING THE AREA FROM THE
NORTHWEST BY NEXT TUESDAY. LATE FRIDAY AND SATURDAY...A WEAK UPPER
SHORTWAVE TROUGH OVER THE GREAT LAKES FRIDAY WILL MOVE SE ACROSS THE
REGION SATURDAY FOLLOWED BY ANOTHER SOUTHEASTERN SHORTWAVE MOVING
THROUGH ON SUNDAY. THE COMBINATION OF DIURNAL INSTABILITY AND SOME
DEGREE OF UPPER FORCING WILL SUPPORT FOR THE DEVELOPMENT OF
THUNDERSTORMS ACROSS MUCH OF THE REGION. SO I KEPT POPS IN THE 30S
SAT/SUN. MONDAY AND TUESDAY...AN UPPER LOW OVER THE DAKOTAS MONDAY
WILL MOVE SOUTHEAST ACROSS IN/KY...PUSHING A COLD FRONT SE INTO OUR
FORECAST AREA BY LATE MON/EARLY TUESDAY. HOWEVER DUE TO THE
UNCERTAINTY...I MENTIONED POPS ONLY IN THE 20S FOR MON NIGHT /TUES.
DAYTIME TEMPERATURES WILL REMAIN IN THE UPPER 70S AND SOME 80S
THROUGH OUT THE EXTENDED FORECAST PERIOD.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...LATEST SATELLITE IMAGES INDICATE MOSTLY
CLEAR CONDITIONS ACROSS THE WESTERN CAROLINAS...ONLY A FEW CONTRAILS
ACROSS THE PIEDMONT OF NC. AREAS ACROSS THE GA COAST HAS BEEN
GATHERING MVFR CLOUDS THROUGH THE DAY. NAM GUIDANCE INDICATES THAT
THE GA COASTAL MOISTURE WILL LIFT ACROSS THE PIEDMONT AND UPPER
SAVANNAH RIVER VALLEY DURING THE PRE DAWN HOURS. HOWEVER...LATEST
LAV GUIDANCE AND RUC GUIDANCE INDICATES LESS POTENTIAL FOR LOW
CLOUDS LATE TONIGHT. I WILL INDICATE A SHORT PERIOD OF MVFR CEILINGS
AT KAND BETWEEN 12Z TO 14Z. OTHERWISE...EXPECT CONDITIONS ACROSS THE
TERMINALS TO REMAIN VFR WITH LIGHT SE TO SW WINDS THROUGH THE PERIOD.
OUTLOOK...HIGH PRESSURE WILL KEEP VFR CONDITIONS ACROSS THE AREA
THROUGH WEDNESDAY. ANOTHER COLD FRONT IS EXPECTED TO MOVE IN FROM
THE NW EARLY THURSDAY WITH SCATTERED SHOWERS AND THUNDERSTORMS OVER
THE NC MOUNTAINS RESULTING IN POSSIBLE CIG RESTRICTIONS LATE WED AND
INTO THURS. HIGH PRESSURE WILL BUILD BACK INTO THE AREA BEHIND THE
COLD FRONT ON FRIDAY.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...NED
SHORT TERM...RWH
LONG TERM...JOH
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
259 PM EDT TUE MAR 27 2012
.SYNOPSIS...
DRY SURFACE HIGH WILL LINGER OVER THE AREA TONIGHT THROUGH
WEDNESDAY. A WEAK COLD FRONT WILL THEN SWEEP ACROSS THE REGION EARLY
THURSDAY FOLLOWED BY ANOTHER RIDGE OF DRY HIGH PRESSURE MOVING BACK
IN BEHIND THE FRONT ON FRIDAY. A SERIES OF UPPER SHORTWAVE SYSTEMS
WILL AFFECT OUR WEATHER THIS WEEKEND.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
SKY COVER ACROSS THE CWA SHOULD REMAIN CLEAR THROUGH THE EVENING
HOURS...ONLY A FEW CONTRAILS. LATEST SATELLITE LOOP INDICATED A
GATHERING AREA OF LOW CLOUDS ALONG THE GA COAST. A FEW MESOSCALE
MODELS INDICATE THAT THE MOISTURE WILL ADVECT NW
OVERNIGHT...REACHING THE CAROLINA PIEDMONT AND UPPER SAVANNAH RIVER
VALLEY LATE TONIGHT INTO WEDNESDAY MORNING. HOWEVER...RECENT RUNS OF
THE RUC AND LAMP MODELS HAVE BEEN BACKING AWAY FROM THIS
SOLUTION...KEEPING THE MOISTURE FURTHER SOUTH ACROSS GA. I WILL USE
A COMPROMISE IN THE FORECAST...INDICATING PARTLY CLOUDY CONDITIONS
BY SUNRISE. LOW TEMPERATURES ARE EXPECTED TO RANGE FROM THE LOW 50S
ACROSS THE UPPER SAVANNAH RIVER VALLEY TO THE L40S ACROSS THE MTN
VALLEYS AND ALONG AND NORTH OF I-40.
WEDNESDAY...A SLOW MOVING COLD FRONT...ORIENTED SW TO NE...WILL
SLOWLY SLIDE SOUTHEAST ACROSS KY AND WV DURING THE AFTERNOON. AS THE
FRONT APPROACHES...HIGH PRESSURE WILL REMAIN CENTERED NEAR THE FL
PANHANDLE...PLACING THE CWA WITHIN A 4-6 MB PRESSURE GRADIENT.
SOUTHWEST WINDS SHOULD INCREASE THROUGH THE AFTERNOON INTO THE TEENS
GUSTING INTO THE L20S. TEMPERATURES SHOULD STEADILY WARM THROUGH THE
DAY...PEAKING IN THE MID TO U70S EAST OF THE MTNS AND WITHIN THE MTN
VALLEYS. HOWEVER...DEWPOINTS WILL REMAIN AROUND 50 DEGREES AND RH
VALUES SHOULD FALL BELOW 40 PERCENT. FORECAST SOUNDINGS INDICATE
THAT H85 FLOW WILL BECOME NEARLY DUE WEST WITH SPEEDS AROUND 30
KTS...RESULTING IN WIDESPREAD DOWNSLOPE FLOW ACROSS THE FOOTHILLS
AND PIEDMONT. CIN VALUES MAY CONTINUE TO RANGE ABOVE 40 J/KG EAST OF
THE MTNS THROUGH THE AFTERNOON. HOWEVER...THE COMBINATION OF UPSLOPE
FLOW...POSSIBLE OUTFLOW BOUNDARY...AND MODERATE INSTABILITY SHOULD
SUPPORT SCT SHRA/TSRA ACROSS THE TN BORDER COUNTIES BY LATE
AFTERNOON...LITTLE TO NO CHC EAST.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 255 PM TUESDAY...WEAK SHORT WAVE MOVES NORTH OF THE AREA
WEDNESDAY NIGHT. THE WAVE PUSHES A WEAK COLD FRONT SOUTH ACROSS THE
AREA BY EARLY THURSDAY. BEST QG FORCING REMAINS WELL TO OUR NORTH.
HOWEVER...THERE IS SOME WEAK UPPER DIVERGENCE ACROSS THE REGION LATE
WEDNESDAY NIGHT. DEEP MOISTURE REMAINS LIMITED WITH THE FRONT WITH
LITTLE IN THE WAY OF LOW LEVEL INFLOW DUE TO W TO SW WINDS AHEAD OF
THE FRONT. BEST LOW LEVEL CONVERGENCE WILL BE OVER THE MTNS AS WELL.
CONTINUED THE TREND OF HIGH CHC POP FOR THE WRN MTNS TAPERING OFF TO
LOW CHC BLUE RIDGE. ALLOWED A BRIEF PERIOD OF SLIGHT CHC ACROSS THE
ENTIRE CWFA DURING THE EVENING GIVEN THE ELEVATED INSTABILITY AND
SOME WEAK FORCING. THAT SAID...PRECIP CHC OVER THE PIEDMONT IS LOW.
STILL CANNOT RULE OUT AN ISOLATED SVR STORM OVER THE MTNS AND NRN
TIER GIVEN THE MODERATE INSTABILITY AND DECENT SHEAR. ANY CONVECTION
WILL QUICKLY END LATE WED NITE OR EARLY THU MORN WITH CLEARING
SKIES. HIGH PRESSURE BUILDS IN THU NITE THEN SLIDES EAST FRI AS A
WEAK WARM FRONT SLIDES BY TO OUR NW. THIS AND THE DEVELOPING SWLY
FLOW SHUD BE ENUF FOR AN INCREASE IN CLOUDS. HOWEVER...NO PRECIP
EXPECTED FOR NOW. LOWS 10 TO 15 DEGREES ABOVE NORMAL WED NITE FALL
TO 5 TO 10 ABOVE THU NITE. HIGHS THU 10 TO 15 DEGREES ABOVE NORMAL
IN THE CLEARING SKIES AND DEVELOPING DOWNSLOPE FLOW REMAIN NEARLY
STEADY OVER THE MTNS FRI AND FALL AROUND 5 DEGREES ELSEWHERE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 230 PM TUESDAY...THE LATEST MODELS ARE IN FAIR AGREEMENT WITH
A SERIES OF UPPER SHORTWAVE SYSTEMS MOVING ACROSS THE REGION THIS
WEEKEND WITH ANOTHER FRONTAL SYSTEM APPROACHING THE AREA FROM THE
NORTHWEST BY NEXT TUESDAY. LATE FRIDAY AND SATURDAY...A WEAK UPPER
SHORTWAVE TROUGH OVER THE GREAT LAKES FRIDAY WILL MOVE SE ACROSS THE
REGION SATURDAY FOLLOWED BY ANOTHER SOUTHEASTERN SHORTWAVE MOVING
THROUGH BY SUNDAY. THE COMBINATION OF DIURNAL INSTABILITY AND SOME
DEGREE OF UPPER FORCING WILL SUPPORT FOR THE DEVELOPMENT OF
THUNDERSTORMS MAINLY IN THE AFTERNOON HOURS. SO I KEPT POPS IN THE
30S DURING THE PERIOD. MONDAY AND TUESDAY...AN UPPER LOW OVER THE
DAKOTAS MONDAY WILL MOVE EAST ACROSS THE GREAT LAKES PUSHING A COLD
FRONT SE INTO OUR FORECAST AREA BY EARLY TUESDAY. I KEPT MOSTLY DRY
CONDITIONS MONDAY WITH POPS INCREASING TO SLIGHT CHANCE CATEGORY MON
NIGHT /TUES. DAYTIME TEMPERATURES WILL REMAIN IN THE UPPER 70S AND
SOME 80S THROUGH OUT THE EXTENDED FORECAST PERIOD.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...LATEST SATELLITE IMAGES INDICATE MOSTLY
CLEAR CONDITIONS ACROSS THE WESTERN CAROLINAS...ONLY A FEW CONTRAILS
ACROSS THE PIEDMONT OF NC. AREAS ACROSS THE GA COAST HAS BEEN
GATHERING MVFR CLOUDS THROUGH THE DAY. NAM GUIDANCE INDICATES THAT
THE GA COASTAL MOISTURE WILL LIFT ACROSS THE PIEDMONT AND UPPER
SAVANNAH RIVER VALLEY DURING THE PRE DAWN HOURS. HOWEVER...LATEST
LAV GUIDANCE AND RUC GUIDANCE INDICATES LESS POTENTIAL FOR LOW
CLOUDS LATE TONIGHT. I WILL INDICATE A SHORT PERIOD OF MVFR CEILINGS
AT KAND BETWEEN 12Z TO 14Z. OTHERWISE...EXPECT CONDITIONS ACROSS THE
TERMINALS TO REMAIN VFR WITH LIGHT SE TO SW WINDS THROUGH THE PERIOD.
OUTLOOK...HIGH PRESSURE WILL KEEP VFR CONDITIONS ACROSS THE AREA
THROUGH WEDNESDAY. ANOTHER COLD FRONT IS EXPECTED TO MOVE IN FROM
THE NW EARLY THURSDAY WITH SCATTERED SHOWERS AND THUNDERSTORMS OVER
THE NC MOUNTAINS RESULTING IN POSSIBLE CIG RESTRICTIONS LATE WED AND
INTO THURS. HIGH PRESSURE WILL BUILD BACK INTO THE AREA BEHIND THE
COLD FRONT ON FRIDAY.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...NED
SHORT TERM...RWH
LONG TERM...JOH
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
158 PM EDT TUE MAR 27 2012
.SYNOPSIS...
DRY SURFACE HIGH WILL LINGER OVER THE AREA TONIGHT THROUGH
WEDNESDAY. A WEAK COLD FRONT WILL THEN SWEEP ACROSS THE REGION EARLY
THURSDAY FOLLOWED BY ANOTHER RIDGE OF DRY HIGH PRESSURE MOVING BACK
IN BEHIND THE FRONT ON FRIDAY. A SERIES OF UPPER SHORTWAVE SYSTEMS
WILL AFFECT OUR WEATHER THIS WEEKEND.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 1015 AM EDT...SKY CONDITIONS SHOULD REMAIN CLEAR TO MOSTLY
CLEAR THROUGH THIS AFTERNOON. RECENT SATELLITE TRENDS INDICATE
THINNING HIGH CLOUDS WEST OF THE SOUTHERN APPALACHIANS. FORECAST
SOUNDINGS INDICATE A FAIRLY DRY LLVL PROFILE...WITH SEVERAL DEGREE
DEWPOINT DEPRESSION AT THE BASE OF A H9 INVERSION...RESULTING IN
LOW CHCS FOR CONVECTIVE CU. BASED ON OBS AND LAV GUIDANCE...I WILL
WARM HIGH TEMPS A COUPLE OF DEGREES...INDICATING HIGHS AT OR
SLIGHTLY ABOVE CLIMO. AFTERNOON RH VALUES EAST OF THE MTNS MAY
FALL TO AROUND 25 PERCENT ACROSS THE CAROLINA FOOTHILLS AND
PIEDMONT.
AS OF 5 AM EDT...NEAR TERM FCST ON TRACK PER PREVIOUS DISCUSSION.
ALL METARS SHOWING CLR SKIES WITH NO HIGH CLOUDS AND NORTHEASTERLY
WINDS. MIN TEMPS WERE BUMPED UP A DEGREE OR 2 BASED ON THE OVERALL
SLOWER DECOUPLING SO FAR THIS EVENING/MORNING AND THE MOST RECENT
ADJMAV GUIDANCE THAT IS WARMER. SO...THE FROST POTENTIAL IS LOOKING
LOWER THAN PREVIOUSLY THOUGHT. STILL MIGHT SEE SOME PATCHY AREAS
OVER THE SHELTERED NC MT VALLEYS...BUT THEY LIKELY WONT GET COLD
ENOUGH AND/OR MOIST ENOUGH OVER THE NEXT FEW HOURS.
PREVIOUS DISCUSSION...
AS OF 2 AM EDT...CLEAR AND COOL CONDITIONS CONTINUE OVER THE REGION
AS THE UPPER RIDGE MAKES ITS WAY ACROSS THE MISS RIVER VALLEY AND
EVENTUALLY TO OUR DOORSTEP. THE CANADIAN SFC HIGH WILL SLIDE SE
TODAY AND TONIGHT AND IS EXPECTED TO BE CENTERED JUST SE OF THE
CAROLINA COAST BY 12Z WED. WINDS WILL GRADUALLY VEER AROUND FROM
NELY TO EASTERLY AND THEN SELY BY THE END OF THE PERIOD EARLY WED AS
THE HIGH MOVES SE. A BACKDOOR COLD FRONT IS MAKING ITS WAY INTO THE
NORTHERN NC FOOTHILLS AS WE SPEAK WITH DEWPTS BEGINNING TO DROP AS
EXPECTED. FROST POTENTIAL THIS MORNING IS STILL LOOKING PRETTY
MEAGER FOR MOST OF THE CWFA. ABOUT THE ONLY AREAS THAT MIGHT SEE
SOME PATCHY FROST WOULD BE SOME OF THE SHELTERED MT VALLEYS OVER NC.
SKIES SHOULD BE MOSTLY CLEAR TODAY AND TONIGHT WITH NO POPS THRU THE
PERIOD. CLOUD COVER WILL LIKELY BEGIN TO INCREASE FROM SOUTH TO
NORTH WED MORNING AS SOUTHERLY LOW LVL FLOW INCREASES AND THE BNDY
LAYER MOISTENS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 315 AM TUESDAY...THE MAIN FOCUS OF THE SHORT RANGE IS THE
PASSAGE OF A SHORT WAVE ACROSS THE MID ATLANTIC STATES ON WEDNESDAY
NIGHT. THE UPPER WAVE SHOULD HELP TO DRIVE A SURFACE BOUNDARY DOWN
FROM THE N EARLY THURSDAY. THE WAY IT STANDS RIGHT NOW...IT LOOKS
LIKE MOST OF THE UPPER FORCING WILL MOVE PAST TO OUR NORTH AND
NORTHEAST...ALTHO SOME WEAK UPPER DIVERGENCE IS FCST TO MOVE DOWN
ACROSS THE REGION LATE WEDNESDAY NIGHT. THE LATEST MODEL RUNS SHOW
LESS OF A DEEP MOISTURE RIBBON ALONG THE FRONT...AND CONSEQUENTLY
DEVELOP LESS IN THE WAY OF PRECIP...ESPECIALLY OUTSIDE THE MTNS.
THERE IS A SLIGHT TREND TOWARD DELAYING THE APPROACH OF THE FRONT...
SO PRECIP CHANCES WERE PUT OFF UNTIL WEDNESDAY AFTERNOON AND WERE
LIMITED TO THE MTNS AND FOOTHILLS. A SLIGHT CHANCE WAS EXTENDED DOWN
OVER THE WRN PIEDMONT AND NRN UPSTATE AHEAD OF THE FRONT WEDNESDAY
EVENING...AND THINK THAT SHOULD SUFFICE AS A STRENGTHENING WESTERLY
FLOW AT 850MB IS GENERALLY ANATHEMA TO CONVECTIVE DEVELOPMENT. IT
WILL PROBABLY TAKE SOME BAND OF CONVERGENCE IN THE LEE OF THE HIGHER
TERRAIN TO GET A FEW STORMS TO DEVELOP OR SURVIVE. THE BETTER CHANCE
WILL REMAIN OVER THE NC MTNS...ESPECIALLY ON THE TN BORDER...AS
STORMS DEVELOP OVER THE CUMBERLAND PLATEAU LATE IN THE DAY AND REACH
THE MTNS BEFORE DYING. THE NC PART OF THE FCST AREA STANDS THE BEST
CHANCE FOR SEVERE WEATHER AS SHEAR INCREASES NWD TOWARD VIRGINIA...
BUT IT LOOKS LIKE A LOW PROBABILITY UNTIL THERE IS A BETTER
INDICATION THAT STORMS WILL DEVELOP E OF THE MTNS. THE SLIGHT CHANCE
WILL GRADUALLY SINK S EARLY THURSDAY WITH THE SURFACE BOUNDARY...AND
AFTER SUNRISE ON THURSDAY SHOULD BE LIMITED TO THE TN BORDER WHERE A
BRIEF NW FLOW UPSLOPE WILL WEAKEN BY MIDDAY. THURSDAY AFTERNOON AND
THURSDAY NIGHT LOOK DRY...AS DOES FRIDAY AS HIGH PRESSURE MOVES
OVERHEAD. TEMPS FOLLOW A GUIDANCE BLEND...STILL ABOVE NORMAL TO WELL
ABOVE NORMAL...EXCEPT FOR WEDNESDAY NIGHT WHERE THE GFS/MAV WAS
FAVORED WITH ITS PROGRESSION OF THE FRONT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
AS OF 330 AM TUESDAY...FEW CHANGES ARE NECESSARY FOR THE MEDIUM
RANGE. THE LATEST GFS IS IN GENERAL AGREEMENT WITH OUR CURRENT
FORECAST OF A CHANCE OF PRECIP STARTING SATURDAY AS MOISTURE AND
WARM ADVECTION INCREASE AHEAD OF A SHORT WAVE AND SURFACE FRONT. THE
FRONT LOOKS LIKE IT WILL MOVE THROUGH EARLY ON SUNDAY...SO THE
CHANCES OF SHOWERS LOOK WARRANTED FOR SATURDAY NIGHT AND SUNDAY. THE
ONLY CHANGE WAS TO SOME OF THE MIN TEMPS TO INCREASE THE N TO S
GRADIENT ACROSS THE REGION AFTER THE FRONT MOVES THROUGH.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...LATEST SATELLITE IMAGES INDICATE MOSTLY
CLEAR CONDITIONS ACROSS THE WESTERN CAROLINAS...ONLY A FEW CONTRAILS
ACROSS THE PIEDMONT OF NC. AREAS ACROSS THE GA COAST HAS BEEN
GATHERING MVFR CLOUDS THROUGH THE DAY. NAM GUIDANCE INDICATES THAT
THE GA COASTAL MOISTURE WILL LIFT ACROSS THE PIEDMONT AND UPPER
SAVANNAH RIVER VALLEY DURING THE PRE DAWN HOURS. HOWEVER...LATEST
LAV GUIDANCE AND RUC GUIDANCE INDICATES LESS POTENTIAL FOR LOW
CLOUDS LATE TONIGHT. I WILL INDICATE A SHORT PERIOD OF MVFR CEILINGS
AT KAND BETWEEN 12Z TO 14Z. OTHERWISE...EXPECT CONDITIONS ACROSS THE
TERMINALS TO REMAIN VFR WITH LIGHT SE TO SW WINDS THROUGH THE PERIOD.
OUTLOOK...HIGH PRESSURE WILL KEEP VFR CONDITIONS ACROSS THE AREA
THROUGH WEDNESDAY. ANOTHER COLD FRONT IS EXPECTED TO MOVE IN FROM
THE NW EARLY THURSDAY WITH SCATTERED SHOWERS AND THUNDERSTORMS OVER
THE NC MOUNTAINS RESULTING IN POSSIBLE CIG RESTRICTIONS LATE WED AND
INTO THURS. HIGH PRESSURE WILL BUILD BACK INTO THE AREA BEHIND THE
COLD FRONT ON FRIDAY.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...NED
SHORT TERM...PM
LONG TERM...PM
AVIATION...NED
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
920 PM CDT WED MAR 28 2012
.DISCUSSION.../ISSUED AT 920 PM CDT/
SEEING SOME LIGHT SHOWERS SHOWING UP ON RADAR ACROSS EASTERN
NEBRASKA AND PORTIONS OF IOWA ASSOCIATED WITH AN AREA OF THETAE
ADVECTION ON THE NOSE OF AN INCREASING LOW LEVEL JET. THIS AREA WILL
CONTINUE TO MOVE NORTH...REACHING SIOUX CITY BY 6Z AND SIOUX FALLS
BY 9Z. TOUGH TO SAY WHETHER WE GET MUCH OUT OF THIS THROUGH 12Z.
BEST CHANCE OF SEEING A SHOWER WILL BE RIGHT ALONG THE ELEVATED
INSTABILITY BOUNDARY....WHICH ACCORDING TO THE NAM WILL RUN FROM
SIOUX CITY NORTHWEST THROUGH SIOUX FALLS AND HURON. ELEVATED CAPE
ONLY EXPECTED TO BE A FEW HUNDRED J/KG. THUS NOT EXPECTING ANYTHING
SIGNIFICANT THROUGH 12Z...IN FACT WE MIGHT NOT EVEN BE ABLE TO GET
ANY THUNDER OUT OF THESE SHOWERS. FURTHER WEST...MUCAPE WILL BE
HIGHER...BUT THE COMBINATION OF LESS LOW LEVEL LIFT AND WARMER TEMPS
ALOFT ACTING AS A CAP...SHOULD PREVENT ANYTHING FROM FORMING THERE.
LATEST HRRR IS FURTHER SOUTHWEST WITH THE BEST LOW LEVEL MOISTURE
RETURN AND ELEVATED CAPE...AND KEEPS OUR ENTIRE CWA DRY THROUGH 12Z.
FOR NOW...DECIDED TO KEEP POPS IN THROUGH THE OVERNIGHT WITH THE
NAM...GFS AND SREF SHOWING SOME SPOTTY SHOWERS. /CHENARD
PREVIOUS DISCUSSION...
SURFACE RIDGE NOSING THROUGH MINNESOTA WILL BEGIN TO SLIP EAST WITH
AN INCREASING EAST TO SOUTHEAST FLOW ACROSS THE AREA. NOT MUCH FOR
IMMEDIATE MOISTURE RETURN...BUT 50S TO LOWER 60S DEWPOINTS ARE
GATHERING ACROSS KANSAS...WITH ELEVATED CONVECTION DEVELOPING ACROSS
SOUTHERN NEBRASKA. MORE SURFACE BASED CONVECTION IS EXPECTED TO
DEVELOP ALONG THE SURFACE TO 925 HPA MOISTURE DISCONTINUITY THIS
EVENING...AND THIS WILL LIKELY DISRUPT THE DEVELOPMENT OF THE LOW
LEVEL JET SOMEWHAT. HOWEVER...BY LATE NIGHT...SOME ELEVATED CAPES
FROM 800 HPA ON THE ORDER OF 400-600 J/KG WITH CAP WEAK ON ORDER OF
25 J/KG OR LESS...BUT DISTRIBUTED OVER ABOUT A 100 HPA DEEP LAYER...
SUGGESTING WILL NEED SOME APPRECIABLE FORCING TO GET ANY ELEVATED
ACTIVITY...WHICH WILL LIKELY WAIT UNTIL LOW LEVEL JET BECOMES
ESTABLISHED...ESPECIALLY TOWARD 12Z...AND USED THE GRADIENT IN
ELEVATED INSTABILITY TO DEFINE TIMING.
CONCERN IN PLACE THAT AFTER THE INITIAL ELEVATED PUSH DURING THE
EARLY TO MID MORNING HOURS...THAT MAY SEE A FAIRLY QUIET PERIOD FOR
MOST UNTIL STRONGER DYNAMIC FORCING ASSOCIATED WITH MID LEVEL WAVE
FROM THE WEST DURING THE AFTERNOON. SOME DISTRIBUTION OF
PRECIPITATION ISSUES WILL DEPEND ON DESTABILIZATION/BOUNDARY
LOCATIONS FROM MORNING ACTIVITY...BUT IN GENERAL WILL BE A BETTER
CHANCE FROM NEAR I29 AND EAST DURING THE AFTERNOON...AND ESPECIALLY
BY LATER IN THE DAY. AT THIS TIME...SEVERE WEATHER WOULD APPEAR TO
BE A FAIRLY MINIMAL THREAT WITH A LACK OF INSTABILITY...WITH
EFFECTIVE SHEAR PERHAPS INDICATING A MARGINAL ORGANIZATION/HAIL
THREAT THROUGH THE SOUTHERN TIER WITH THE AFTERNOON DEVELOPMENT.
TEMPERATURES DIFFICULT WITH UNCERTAINTY IN CONVECTIVE POTENTIAL...
BUT HEDGED TEMPS DOWN A BIT WITH EXPECTED CLOUDS/PRECIPITATION
AND FAIRLY STABLE LOW LEVEL CONDITIONS. /CHAPMAN
WINDS WILL DECREASE ON THURSDAY NIGHT ALLOWING FOR DECENT
RADIATIONAL COOLING. NOT TO THE EXTENT OF THIS MORNING BUT ENOUGH
THAT WILL LEAN ON THE COOLER GUIDANCE OR A LITTLE BELOW...WHICH
MEANS LOWS FROM THE UPPER 30S TO LOWER 40S.
FRIDAY INTO SUNDAY WILL SEE BROAD SCALE RIDGING DEVELOP WITH WARMING
TO WAY ABOVE NORMAL AGAIN...FOR FRIDAY INTO SUNDAY. HIGHS SATURDAY
MAY EXCEED 90 IN A FEW LOCATIONS IF SOMETHING CLOSER TO THE NAM/GFS
VERIFIES WHILE MID TO UPPER 80S WOULD BE THE WARMEST PER THE ECMWF.
FRIDAY AND SUNDAY STILL WAY ABOVE NORMAL BUT MORE IN THE 70S TO
LOWER 80S...ALTHOUGH NORTHWEST IOWA COULD SEE SOME MID 80S ON SUNDAY
AHEAD OF THE INCOMING FRONT. FRIDAY NIGHT WILL BE WARM WITH SOME
SOUTHERLY FLOW...BUT NOT EXCESSIVELY STRONG. SATURDAY NIGHT WILL BE
VERY WARM WITH STRONGER SOUTHERLY FLOW. LOOKING AT LOWS IN THE MID
TO UPPER 50S SATURDAY NIGHT.
IN THE LATTER PERIODS(SUN/WED)...MODELS STILL IN AGREEMENT WITH
BRINGING A WAVE THROUGH ON MONDAY BUT STILL DIFFER ON STRENGTH AND
PLACEMENT QUITE A BIT. THIS TIME AROUND MODELS ARE A LITTLE LESS
COLD WHICH IS ABOUT THE ONLY TREND TO GRAB ON TO. MOISTURE STILL
LIMITED ON SUNDAY AFTERNOON/SUNDAY NIGHT SO WILL MAINTAIN A CHANCE
FOR THUNDERSTORMS BUT THEY MIGHT BE HARD TO COME BY IF MODELS DO NOT
BEGIN TO INCREASE MOISTURE A LITTLE MORE. OTHERWISE...WHILE COLDER
DURING THIS TIME FRAME STILL LOOKING AT ABOVE NORMAL TEMPERATURES.
LOOKING AT HIGHS ON MONDAY...TUESDAY AND WEDNESDAY IN THE 50S WITH
LOWS GENERALLY IN THE 30S. NO MAJOR CHANCES FOR PRECIPITATION DURING
THIS TIME.
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
VFR CONDITIONS WILL BE PREVALENT THIS EVENING WITH A DEVELOPING
EASTERLY FLOW OF AIR. BY AROUND MIDNIGHT AND AFTER MIDNIGHT
TONIGHT...STRONG WARM AIR ADVECTION ABOVE THE SURFACE MAY HELP TO
DEVELOP A FEW ELEVATED THUNDERSTORMS...ESPECIALLY ALONG AND SOUTH OF
THE I 90 CORRIDOR. BUT OVERALL AFTER MIDNIGHT...CONDITIONS SHOULD
REMAIN VFR. MORE RAINFALL WITH SHOWERS AND THUNDERSTORMS IS EXPECTED
ON THURSDAY...MOVING EASTWARD THROUGH THE DAY. THE DEVIL IS IN THE
DETAILS ON EXACT TIMING OF THE GREATEST POTENTIAL OF SHOWERS OR
THUNDERSTORMS. RIGHT NOW...IT APPEARS THE BEST CHANCES FOR
THUNDERSTORMS WILL BE CONFINED TO THE AFTERNOON HOURS IN NORTHWEST
IOWA AHEAD OF THE SURFACE WIND SHIFT. LEFT EXPLICIT THUNDERSTORM
MENTION OUT OF THE KFSD AND KHON TAF SITES...AS STABILITY INCREASES
TO THE NORTH AND WEST OF OUR NORTHWEST IOWA ZONES. BUT STILL...
CANNOT RULE OUT SOME GENERAL THUNDER NEARLY ANYWHERE IN OUR FORECAST
AREA ON THURSDAY EMBEDDED WITH SHOWERS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1256 PM CDT WED MAR 27 2012
.DISCUSSION.../ISSUED AT 1122 AM CDT/
WINDS AND FIRE WEATHER ARE PRIMARY CONCERN FOR THE UPDATE. LATEST
NAM APPEARS TO HAVE A SLIGHT LOW WIND BIAS AGAIN...AND PREFER RUC
WINDS WHICH MATCH UP A BIT BETTER WITH CURRENT OBSERVATIONS.
SOMEWHAT MIXED SIGNALS WITH NAM COMING IN A TOUCH COOLER WITH OFF
SURFACE TEMPERATURES...AND 15Z RUC JUST RECENTLY WARMER. DID END UP
TAKING A COUPLE DEGREES OFF MAX TEMPS FOR THE DAY...AND EXPECT WILL
GET TO NEAR THE MAX BY EARLY AFTERNOON AS WINDS ALREADY REFLECT
MIXING TOWARD 850 HPA...AND DO GET COOLING OF OFF SURFACE
TEMPERATURES THROUGH THE AFTERNOON TO SUGGEST A LONG TERM NEAR MAX
TRACE. THE COOLING ALOFT WILL ALSO KEEP A STRONG TIE TO THE FLOW
ALOFT...WHICH SHOULD SETTLE INTO THE 35 TO 40 KNOT RANGE NEAR TOP OF
MIXED LAYER THROUGH THE EARLY TO MID AFTERNOON...BUT A BIT LESSER
TOWARD THE MISSOURI RIVER.
FOR THE FIRE WEATHER HEADLINES...LOWER LEVEL MOISTURE WRAPPING
AROUND THE EXITING LOW PRESSURE HAS BROUGHT DEWPOINTS UP INTO THE
UPPER 30S TO LOWER 40S. THERE SHOULD BE SOME DECREASE HEADING TOWARD
MID AFTERNOON...BUT WILL PROBABLY NOT BE ENOUGH TO GET THE MID JAMES
VALLEY RELATIVE HUMIDITIES OUT OF THE 30S. LOWEST RELATIVE
HUMIDITIES SHOULD BE FOUND THROUGH THE MISSOURI CORRIDOR...
APPROACHING 25 PERCENT. EXTREME FIRE DANGER WILL CONTINUE ELSEWHERE
WITH WINDS...AND WARMER SEASON FUELS STILL TINDER DRY.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. STRONG WESTERLY
WINDS ARE EXPECTED TODAY. GUSTS OF 35 TO 40 KNOTS CAN BE
EXPECTED NORTH OF INTERSTATE 90 TODAY. THE WINDS WILL QUICKLY
SUBSIDE WITH SUNSET TONIGHT.
&&
.PREV DISCUSSION.../ISSUED AT 415 AM CDT/
WEAK BAND OF SHOWERS WITH ISOLATED THUNDER AHEAD OF THE FRONT IS
RAPIDLY FALLING APART AS IT MOVES INTO THE EASTERN REACHES OF THE
CWA. WITH THE FRONT EXPECTED TO CLEAR THE FORECAST AREA WITHIN THE
NEXT SEVERAL HOURS...THE PRECIPITATION CHANCES WILL COME TO AN END.
WINDS WILL BE WELL MIXED BEHIND THE FRONT AS THEY TURN MORE WESTERLY
THIS MORNING. WITH 925 MB WINDS AROUND 40 KT...EXPECT SURFACE WINDS
TO BE WELL WITHIN WIND ADVISORY LEVEL FROM MID MORNING THROUGH EARLY
EVENING. STRONGEST WINDS WILL BE ACROSS THE NORTH CLOSEST TO THE
EXITING SURFACE LOW. TEMPERATURES WILL BE MARKEDLY COOLER TODAY
ACROSS THE WEST WHILE THE NORTHEAST CORNER OF THE CWA WILL BE A BIT
WARMER WITH SOLID MIXING IN PLACE.
THE ADDITIONAL CONCERN WITH THE STRONG WINDS TODAY WILL BE IN
REGARD TO FIRE WEATHER. MIXED DEWPOINTS WILL BE ESPECIALLY LOW
ACROSS THE WEST AND SOUTH TODAY AS DRY AIR RUSHES IN BEHIND THE
EXITING TROUGH. EXPECT THE LOWEST DEWPOINTS AROUND 20 TO 25 PERCENT
IN THESE AREAS WHILE THE EAST CENTRAL SD...SW MN AND NORTHERN IA
WILL BE CLOSER TO THE 30 TO 40 PERCENT LEVEL. NO DOUBT THAT
RANGELAND FIRE DANGER WILL BE EXTREME TODAY...HOWEVER HAVE CHOSEN TO
DROP THE FIRE WEATHER WATCH MN AND OUR EASTERN IA ZONE WHERE
HUMIDITY WILL NOT REACH RED FLAG LEVEL BUT WILL PLACE A STRONGLY
WORDED HEADLINE ABOUT CONCERNS. ELSEWHERE...THE RED FLAG WARNING
CONTINUES FOR THIS AFTERNOON AND EVENING.
WINDS WILL TAPER OFF TONIGHT AS THE SURFACE LOW HEADS INTO THE GREAT
LAKES AND SURFACE HIGH PRESSURE MAKES A RETURN. UPPER LEVEL RIDGING
MAKES A RETURN ON WEDNESDAY WINDS FLOW TURNS MORE EAST SOUTHEASTERLY
BY WEDNESDAY EVENING. THIS WILL RESULT IN A SLIGHTLY COOLER DAY WITH
MUCH LESS FAVORABLE MIXING EVEN WITH MOSTLY CLEAR SKIES. HOWEVER...
EVEN THESE COOLER READINGS WILL STILL REMAIN WELL ABOVE NORMAL WITH
HIGHS IN THE UPPER 50S TO NEAR 70.
A MORE ACTIVE PATTERN SETS UP BEGINNING LATE WEDNESDAY NIGHT WITH
THE RIDGE SHIFTING INTO THE MISSISSIPPI VALLEY AND A SERIES OF WAVES
EXPECTED TO TRACK NORTHEASTWARD INTO THE CENTRAL PLAINS. STRONG WARM
AIR ADVECTION COUPLED WITH A STRENGTHENING LOW LEVEL JET WEDNESDAY
NIGHT AND THURSDAY WILL SET THE STAGE FOR SOME POTENTIAL
THUNDERSTORM DEVELOPMENT. MODELS DIVERGE A BIT WITH REGARDS TO THE
STRENGTH AND TIMING OF THE WAVE...HOWEVER COULD SEE SOME STORMS NEAR
OUR WESTERN BORDER AS EARLY AS LATE WEDNESDAY NIGHT WITH WARM
FRONTAL DEVELOPMENT BUILDING NORTHWARD DURING THE DAY ON THURSDAY.
RIGHT NOW IT LOOKS LIKE A FAIRLY STRONG CAP COULD LIMIT DEVELOPMENT
ON THURSDAY...WITH A BETTER POTENTIAL FOR DEVELOPMENT ON THURSDAY
NIGHT ACROSS OUR EAST.
WEAK QUASI-ZONAL FLOW RETURN ON FRIDAY INTO SATURDAY. THE GFS PULLS A
WEAK WAVE ACROSS THE NORTHERN PLAINS ON FRIDAY NIGHT BRINGING SOME
THUNDERSTORM POTENTIAL WHILE THE ECMWF STRENGTHENS THE RIDGE WITH A
DRIER SCENARIO. BY EARLY NEXT WEEK...MODELS HINT AT A DEEP TROUGH
DIGGING INTO THE ROCKIES SUNDAY THROUGH SUNDAY NIGHT. THE GFS IS
QUITE A BIT FASTER IN BRING THIS SYSTEM INTO THE PLAINS...HOWEVER IT
IS ALSO STRONGER THAN THE ECMWF AND THEREFORE SLOWS THE TROUGH AS IT
BECOMES CUT OFF OVER THE CENTRAL PLAINS ON MONDAY. WITH THESE
SIGNIFICANT MODEL DIFFERENCES...DID NOT ALTER MUCH FROM THE
CONSENSUS NUMBERS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...RED FLAG WARNING FROM 11 AM TO 7 PM CDT TUESDAY FOR IAZ300.
WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR IAZ001>003-012>014-
020>022-031-032.
MN...WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR MNZ071-072-080-081-089-
090-097-098.
NE...RED FLAG WARNING FROM 11 AM TO 7 PM CDT TUESDAY FOR NEZ249.
WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR NEZ013-014.
SD...RED FLAG WARNING FROM 11 AM TO 7 PM CDT TUESDAY FOR SDZ255>258.
WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR SDZ038>040-050-052>071.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1122 AM CDT WED MAR 27 2012
.DISCUSSION.../ISSUED AT 1122 AM CDT/
WINDS AND FIRE WEATHER ARE PRIMARY CONCERN FOR THE UPDATE. LATEST
NAM APPEARS TO HAVE A SLIGHT LOW WIND BIAS AGAIN...AND PREFER RUC
WINDS WHICH MATCH UP A BIT BETTER WITH CURRENT OBSERVATIONS.
SOMEWHAT MIXED SIGNALS WITH NAM COMING IN A TOUCH COOLER WITH OFF
SURFACE TEMPERATURES...AND 15Z RUC JUST RECENTLY WARMER. DID END UP
TAKING A COUPLE DEGREES OFF MAX TEMPS FOR THE DAY...AND EXPECT WILL
GET TO NEAR THE MAX BY EARLY AFTERNOON AS WINDS ALREADY REFLECT
MIXING TOWARD 850 HPA...AND DO GET COOLING OF OFF SURFACE
TEMPERATURES THROUGH THE AFTERNOON TO SUGGEST A LONG TERM NEAR MAX
TRACE. THE COOLING ALOFT WILL ALSO KEEP A STRONG TIE TO THE FLOW
ALOFT...WHICH SHOULD SETTLE INTO THE 35 TO 40 KNOT RANGE NEAR TOP OF
MIXED LAYER THROUGH THE EARLY TO MID AFTERNOON...BUT A BIT LESSER
TOWARD THE MISSOURI RIVER.
FOR THE FIRE WEATHER HEADLINES...LOWER LEVEL MOISTURE WRAPPING
AROUND THE EXITING LOW PRESSURE HAS BROUGHT DEWPOINTS UP INTO THE
UPPER 30S TO LOWER 40S. THERE SHOULD BE SOME DECREASE HEADING TOWARD
MID AFTERNOON...BUT WILL PROBABLY NOT BE ENOUGH TO GET THE MID JAMES
VALLEY RELATIVE HUMIDITIES OUT OF THE 30S. LOWEST RELATIVE
HUMIDITIES SHOULD BE FOUND THROUGH THE MISSOURI CORRIDOR...
APPROACHING 25 PERCENT. EXTREME FIRE DANGER WILL CONTINUE ELSEWHERE
WITH WINDS...AND WARMER SEASON FUELS STILL TINDER DRY.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. STRONG WESTERLY
WINDS ARE EXPECTED TODAY. GUSTS UP TO NEAR 45 KNOTS CAN BE EXPECTED
NORTH OF INTERSTATE 90 TODAY. THE WINDS WILL QUICKLY SUBSIDE WITH
SUNSET TONIGHT.
&&
.PREV DISCUSSION.../ISSUED AT 415 AM CDT/
WEAK BAND OF SHOWERS WITH ISOLATED THUNDER AHEAD OF THE FRONT IS
RAPIDLY FALLING APART AS IT MOVES INTO THE EASTERN REACHES OF THE
CWA. WITH THE FRONT EXPECTED TO CLEAR THE FORECAST AREA WITHIN THE
NEXT SEVERAL HOURS...THE PRECIPITATION CHANCES WILL COME TO AN END.
WINDS WILL BE WELL MIXED BEHIND THE FRONT AS THEY TURN MORE WESTERLY
THIS MORNING. WITH 925 MB WINDS AROUND 40 KT...EXPECT SURFACE WINDS
TO BE WELL WITHIN WIND ADVISORY LEVEL FROM MID MORNING THROUGH EARLY
EVENING. STRONGEST WINDS WILL BE ACROSS THE NORTH CLOSEST TO THE
EXITING SURFACE LOW. TEMPERATURES WILL BE MARKEDLY COOLER TODAY
ACROSS THE WEST WHILE THE NORTHEAST CORNER OF THE CWA WILL BE A BIT
WARMER WITH SOLID MIXING IN PLACE.
THE ADDITIONAL CONCERN WITH THE STRONG WINDS TODAY WILL BE IN
REGARD TO FIRE WEATHER. MIXED DEWPOINTS WILL BE ESPECIALLY LOW
ACROSS THE WEST AND SOUTH TODAY AS DRY AIR RUSHES IN BEHIND THE
EXITING TROUGH. EXPECT THE LOWEST DEWPOINTS AROUND 20 TO 25 PERCENT
IN THESE AREAS WHILE THE EAST CENTRAL SD...SW MN AND NORTHERN IA
WILL BE CLOSER TO THE 30 TO 40 PERCENT LEVEL. NO DOUBT THAT
RANGELAND FIRE DANGER WILL BE EXTREME TODAY...HOWEVER HAVE CHOSEN TO
DROP THE FIRE WEATHER WATCH MN AND OUR EASTERN IA ZONE WHERE
HUMIDITY WILL NOT REACH RED FLAG LEVEL BUT WILL PLACE A STRONGLY
WORDED HEADLINE ABOUT CONCERNS. ELSEWHERE...THE RED FLAG WARNING
CONTINUES FOR THIS AFTERNOON AND EVENING.
WINDS WILL TAPER OFF TONIGHT AS THE SURFACE LOW HEADS INTO THE GREAT
LAKES AND SURFACE HIGH PRESSURE MAKES A RETURN. UPPER LEVEL RIDGING
MAKES A RETURN ON WEDNESDAY WINDS FLOW TURNS MORE EAST SOUTHEASTERLY
BY WEDNESDAY EVENING. THIS WILL RESULT IN A SLIGHTLY COOLER DAY WITH
MUCH LESS FAVORABLE MIXING EVEN WITH MOSTLY CLEAR SKIES. HOWEVER...
EVEN THESE COOLER READINGS WILL STILL REMAIN WELL ABOVE NORMAL WITH
HIGHS IN THE UPPER 50S TO NEAR 70.
A MORE ACTIVE PATTERN SETS UP BEGINNING LATE WEDNESDAY NIGHT WITH
THE RIDGE SHIFTING INTO THE MISSISSIPPI VALLEY AND A SERIES OF WAVES
EXPECTED TO TRACK NORTHEASTWARD INTO THE CENTRAL PLAINS. STRONG WARM
AIR ADVECTION COUPLED WITH A STRENGTHENING LOW LEVEL JET WEDNESDAY
NIGHT AND THURSDAY WILL SET THE STAGE FOR SOME POTENTIAL
THUNDERSTORM DEVELOPMENT. MODELS DIVERGE A BIT WITH REGARDS TO THE
STRENGTH AND TIMING OF THE WAVE...HOWEVER COULD SEE SOME STORMS NEAR
OUR WESTERN BORDER AS EARLY AS LATE WEDNESDAY NIGHT WITH WARM
FRONTAL DEVELOPMENT BUILDING NORTHWARD DURING THE DAY ON THURSDAY.
RIGHT NOW IT LOOKS LIKE A FAIRLY STRONG CAP COULD LIMIT DEVELOPMENT
ON THURSDAY...WITH A BETTER POTENTIAL FOR DEVELOPMENT ON THURSDAY
NIGHT ACROSS OUR EAST.
WEAK QUASI-ZONAL FLOW RETURN ON FRIDAY INTO SATURDAY. THE GFS PULLS A
WEAK WAVE ACROSS THE NORTHERN PLAINS ON FRIDAY NIGHT BRINGING SOME
THUNDERSTORM POTENTIAL WHILE THE ECMWF STRENGTHENS THE RIDGE WITH A
DRIER SCENARIO. BY EARLY NEXT WEEK...MODELS HINT AT A DEEP TROUGH
DIGGING INTO THE ROCKIES SUNDAY THROUGH SUNDAY NIGHT. THE GFS IS
QUITE A BIT FASTER IN BRING THIS SYSTEM INTO THE PLAINS...HOWEVER IT
IS ALSO STRONGER THAN THE ECMWF AND THEREFORE SLOWS THE TROUGH AS IT
BECOMES CUT OFF OVER THE CENTRAL PLAINS ON MONDAY. WITH THESE
SIGNIFICANT MODEL DIFFERENCES...DID NOT ALTER MUCH FROM THE
CONSENSUS NUMBERS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...RED FLAG WARNING FROM 11 AM TO 7 PM CDT TUESDAY FOR IAZ300.
WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR IAZ001>003-012>014-
020>022-031-032.
MN...WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR MNZ071-072-080-081-089-
090-097-098.
NE...RED FLAG WARNING FROM 11 AM TO 7 PM CDT TUESDAY FOR NEZ249.
WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR NEZ013-014.
SD...RED FLAG WARNING FROM 11 AM TO 7 PM CDT TUESDAY FOR SDZ255>258.
WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR SDZ038>040-050-052>071.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
415 AM CDT TUE MAR 27 2012
.DISCUSSION.../ISSUED AT 415 AM CDT/
WEAK BAND OF SHOWERS WITH ISOLATED THUNDER AHEAD OF THE FRONT IS
RAPIDLY FALLING APART AS IT MOVES INTO THE EASTERN REACHES OF THE
CWA. WITH THE FRONT EXPECTED TO CLEAR THE FORECAST AREA WITHIN THE
NEXT SEVERAL HOURS...THE PRECIPITATION CHANCES WILL COME TO AN END.
WINDS WILL BE WELL MIXED BEHIND THE FRONT AS THEY TURN MORE WESTERLY
THIS MORNING. WITH 925 MB WINDS AROUND 40 KT...EXPECT SURFACE WINDS
TO BE WELL WITHIN WIND ADVISORY LEVEL FROM MID MORNING THROUGH EARLY
EVENING. STRONGEST WINDS WILL BE ACROSS THE NORTH CLOSEST TO THE
EXITING SURFACE LOW. TEMPERATURES WILL BE MARKEDLY COOLER TODAY
ACROSS THE WEST WHILE THE NORTHEAST CORNER OF THE CWA WILL BE A BIT
WARMER WITH SOLID MIXING IN PLACE.
THE ADDITIONAL CONCERN WITH THE STRONG WINDS TODAY WILL BE IN
REGARD TO FIRE WEATHER. MIXED DEWPOINTS WILL BE ESPECIALLY LOW
ACROSS THE WEST AND SOUTH TODAY AS DRY AIR RUSHES IN BEHIND THE
EXITING TROUGH. EXPECT THE LOWEST DEWPOINTS AROUND 20 TO 25 PERCENT
IN THESE AREAS WHILE THE EAST CENTRAL SD...SW MN AND NORTHERN IA
WILL BE CLOSER TO THE 30 TO 40 PERCENT LEVEL. NO DOUBT THAT
RANGELAND FIRE DANGER WILL BE EXTREME TODAY...HOWEVER HAVE CHOSEN TO
DROP THE FIRE WEATHER WATCH MN AND OUR EASTERN IA ZONE WHERE
HUMIDITY WILL NOT REACH RED FLAG LEVEL BUT WILL PLACE A STRONGLY
WORDED HEADLINE ABOUT CONCERNS. ELSEWHERE...THE RED FLAG WARNING
CONTINUES FOR THIS AFTERNOON AND EVENING.
WINDS WILL TAPER OFF TONIGHT AS THE SURFACE LOW HEADS INTO THE GREAT
LAKES AND SURFACE HIGH PRESSURE MAKES A RETURN. UPPER LEVEL RIDGING
MAKES A RETURN ON WEDNESDAY WINDS FLOW TURNS MORE EAST SOUTHEASTERLY
BY WEDNESDAY EVENING. THIS WILL RESULT IN A SLIGHTLY COOLER DAY WITH
MUCH LESS FAVORABLE MIXING EVEN WITH MOSTLY CLEAR SKIES. HOWEVER...
EVEN THESE COOLER READINGS WILL STILL REMAIN WELL ABOVE NORMAL WITH
HIGHS IN THE UPPER 50S TO NEAR 70.
A MORE ACTIVE PATTERN SETS UP BEGINNING LATE WEDNESDAY NIGHT WITH
THE RIDGE SHIFTING INTO THE MISSISSIPPI VALLEY AND A SERIES OF WAVES
EXPECTED TO TRACK NORTHEASTWARD INTO THE CENTRAL PLAINS. STRONG WARM
AIR ADVECTION COUPLED WITH A STRENGTHENING LOW LEVEL JET WEDNESDAY
NIGHT AND THURSDAY WILL SET THE STAGE FOR SOME POTENTIAL
THUNDERSTORM DEVELOPMENT. MODELS DIVERGE A BIT WITH REGARDS TO THE
STRENGTH AND TIMING OF THE WAVE...HOWEVER COULD SEE SOME STORMS NEAR
OUR WESTERN BORDER AS EARLY AS LATE WEDNESDAY NIGHT WITH WARM
FRONTAL DEVELOPMENT BUILDING NORTHWARD DURING THE DAY ON THURSDAY.
RIGHT NOW IT LOOKS LIKE A FAIRLY STRONG CAP COULD LIMIT DEVELOPMENT
ON THURSDAY...WITH A BETTER POTENTIAL FOR DEVELOPMENT ON THURSDAY
NIGHT ACROSS OUR EAST.
WEAK QUASI-ZONAL FLOW RETURN ON FRIDAY INTO SATURDAY. THE GFS PULLS A
WEAK WAVE ACROSS THE NORTHERN PLAINS ON FRIDAY NIGHT BRINGING SOME
THUNDERSTORM POTENTIAL WHILE THE ECMWF STRENGTHENS THE RIDGE WITH A
DRIER SCENARIO. BY EARLY NEXT WEEK...MODELS HINT AT A DEEP TROUGH
DIGGING INTO THE ROCKIES SUNDAY THROUGH SUNDAY NIGHT. THE GFS IS
QUITE A BIT FASTER IN BRING THIS SYSTEM INTO THE PLAINS...HOWEVER IT
IS ALSO STRONGER THAN THE ECMWF AND THEREFORE SLOWS THE TROUGH AS IT
BECOMES CUT OFF OVER THE CENTRAL PLAINS ON MONDAY. WITH THESE
SIGNIFICANT MODEL DIFFERENCES...DID NOT ALTER MUCH FROM THE
CONSENSUS NUMBERS.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
VFR CONDITIONS WILL DOMINATE THE SIOUX FALLS FORECAST AREA FOR
TONIGHT AND TUESDAY. IN THE SHORTER TERM...A LINE OF CONVECTION HAS
RECENTLY DEVELOPED IN SOUTH CENTRAL SD AND NORTH CENTRAL NEB. THE
HRRR HAS BEEN SHOWING THIS FEATURE THROUGH THE EVENING AND HAS
INITIALIZED IT PRETTY CLOSE IN LOCATION. THE HRRR MOVES THE LINE TO
I 29 BY 07Z TONIGHT...THEN IT BEGINS TO WEAKEN AFTER 07Z WHEN IT
MOVES THROUGH SOUTHWEST MN AND NORTHWEST IA. THEREFORE THE 06Z KFSD
AND KSUX TAFS WILL REFLECT A CHANCE FOR CONVECTION AROUND THE 06Z TO
07Z TIME FRAME FOR KFSD AND KSUX. NOT SURE WHETHER THE LINE WILL
MAKE IT AS FAR NORTH AS KHON IN EAST CENTRAL SD...SO THE CURRENT
SCATTERED CB CLOUD GROUP FOR THE LATE EVENING STILL LOOKS PRUDENT.
THE MAJOR STORY CONTINUES TO BE THE WINDS. THERE WILL BE A LOT OF 25
TO 45 MPH WIND SPEEDS THROUGHOUT THIS ENTIRE AREA TONIGHT AND
TUESDAY. SOME OF THE STRONGEST OF THE WINDS WILL OCCUR FOR A BRIEF
TIME TONIGHT WHEN THE WINDS BECOME SOUTHWESTERLY BEHIND THE LINE OF
CONVECTION...AND ALSO NORTH OF I 90 ON TUESDAY. WINDS WILL SHIFT
FROM THE SOUTHEAST TO SOUTHWEST THROUGH THE NIGHT...AND WILL BE FROM
A WESTERLY DIRECTION ON TUESDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...RED FLAG WARNING FROM 11 AM TO 10 PM CDT TUESDAY FOR IAZ300.
WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR IAZ001>003-012>014-
020>022-031-032.
MN...WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR MNZ071-072-080-081-089-
090-097-098.
NE...RED FLAG WARNING FROM 11 AM TO 10 PM CDT TUESDAY FOR NEZ249.
WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR NEZ013-014.
SD...RED FLAG WARNING FROM 11 AM TO 10 PM CDT TUESDAY FOR SDZ255>258.
WIND ADVISORY UNTIL 7 PM CDT TUESDAY FOR SDZ038>040-050-052>071.
&&
$$
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1016 PM MDT MON MAR 26 2012
.AVIATION...06Z TAF FORECAST
STRONG AND GUSTY WESTERLY WINDS WILL CONTINUE THROUGH TONIGHT AND
TUESDAY...DIMINISHING ON TUESDAY EVENING. MVFR CIGS IN -SHRA ARE
EXPECTED ACROSS PARTS OF FAR NORTHEASTERN WYOMING...THE BLACK
HILLS...AND NORTHWESTERN SOUTH DAKOTA THROUGH THE REST OF THE
NIGHT WITH VFR CONDITIONS OVER THE REST OF THE AREA. CONDITIONS
WILL IMPROVE TO VFR AROUND 16Z TUESDAY.
&&
.FIRE WEATHER...STRONG WINDS WILL CONTINUE THROUGH THE DAY
TUESDAY. TEMPERATURES TUESDAY ARE EXPECTED TO RISE INTO THE UPPER
50S TO UPPER 60S WHILE RELATIVE HUMIDITIES WILL DROP TO AS LOW AS
15 PERCENT. THESE CONDITIONS WILL PRODUCE CRITICAL FIRE WEATHER
CONDITIONS ACROSS MUCH OF THE AREA THROUGH THIS EVENING...AND
AGAIN TUESDAY.
PREV DISCUSSION... /ISSUED 300 PM MDT MON MAR 26 2012/
DISCUSSION...20Z SURFACE ANALYSIS HAD LOW OVER CENTRAL WY WITH
WELL DEFINED WARM FRONT ALONG I-90 AND COLD FRONT DEVELOPING INTO
NORTHEAST CO. 7MB/3HR PRESSURE FALLS AHEAD OF LOW AS SHORTWAVE IS
RAPIDLY MOVING INTO SOUTHEAST WY. HIGHLY ELEVATED RETURNS NOW
SHOWING UP AHEAD OF SHORTWAVE AND ON NOSE OF 100KT JET STREAK.
CONCERN THIS FORECAST IS DISPOSITION OF THESE STRONG WAVE.
12Z/18Z GUIDANCE IN PRETTY GOOD AGREEMENT. IT BRINGS SHORTWAVE OUT
NEGATIVELY-TILTED REACHING EASTERN ND BY 12Z TUESDAY. SURFACE LOW
RAPIDLY DEEPENS OVER NORTHEAST WY LATE THIS AFTERNOON AND RACES
INTO EASTERN ND BY 12Z TUESDAY. COLD FRONT BEHIND LOW RACES EAST-
NORTHEAST THROUGH THIS EVENING...PLOWING THROUGH THE CWA BY 06Z.
AHEAD OF COLD FRONT...LOW 50S TD/S POOLING GIVING AROUND 1KJ/KG
MLCAPE...BUT MLCIN FROM 50-100J/KG JUST AHEAD OF COLD FRONT. THIS
WILL BE A TOUGH CAP TO BREAK FOR SURFACE BASED STORMS...BUT
LATEST HRRR/LOCAL WRF MODEL SUGGESTS AS BEST UPPER LEVEL FORCING
OVERTAKES COLD FRONT JUST NORTHEAST OF SURFACE LOW...WE SHOULD SEE
A CLUSTER OF STORMS DEVELOP. DAMAGING WINDS POSSIBLE WITH ANY
STORM...AND LARGE HAIL WITH ANY SUPERCELL THAT DEVELOPS GIVEN
0-6KM BULK SHEAR REACHING 20-30M/S. STORMS WOULD MOVE AROUND 45KTS
TO THE NORTHEAST. WILL WATCH MESOSCALE DEVELOPMENT FOR SIGNS OF
SURFACE BASED CONVECTION.
OTHER BIG STORY WILL BE WIND BEHIND COLD FRONT. PRESSURE RISES
FORECAST OF 7-11MB BEHIND INITIAL COLD FRONT. COMBINED WITH 850MB
WINDS INCREASING TO 55KTS AND STRONG COLD AIR ADVECTION...IT
SHOULD BE ENOUGH TO PUSH STRONG WEST-SOUTHWEST WINDS TO THE
SURFACE OVER NORTHEAST WY/THE BLACK HILLS/SOUTHWEST SD EARLY THIS
EVENING AND THEN OVER NORTHWEST THROUGH SOUTH CENTRAL SD MID-
EVENING. SUBSIDENCE BEHIND COLD FRONT VERY IMPRESSIVE AND STRONG
DRYING AND LINKAGE THROUGH 700MB. LATEST RUC SHOWING SYSTEM A
LITTLE BIT SLOWER THAN PREVIOUSLY THOUGHT...BUT HEADLINES IN PLACE
WILL ACCOUNT FOR THAT SCENARIO. AS LOW MOVES INTO ND LATER THIS
EVENING...SECONDARY PRESSURE RISE SURGE MOVES INTO NORTHEAST
WY/NORTHWEST SD KEEPING WINDS GOING THERE. WINDS SPEEDS SOUTH OF
I-90 SHOULD DECREASE SOME AFTER 06Z.
TUESDAY...TIGHT GRADIENT WITH 50KT 850MB NORTHWEST WINDS WILL KEEP
HIGH WINDS GOING OVER NORTHWEST PORTIONS OF THE CWA THROUGH
TUESDAY AFTERNOON. WILL LIKELY NEED AT LEAST A WIND ADVISORY
FURTHER SOUTH ON THE SD PLAINS. TEMPERATURES WILL BE NEAR
GUIDANCE WITH A FEW LINGERING SHOWERS OVER THE FAR NORTH UNDER
CYCLONIC FLOW ALOFT.
TUESDAY NIGHT/WEDNESDAY...UPPER RIDGE BUILDS INTO THE CWA BRINGING
QUIET WEATHER TO THE AREA.
EXTENDED...A MAINLY DRY AND WARM WEATHER PATTERN CAN BE EXPECTED
LATE THIS WEEK THROUGH THE WEEKEND AS A WEAK UPPER LEVEL RIDGE
BUILDS OVER THE REGION. A WEAK UPPER LEVEL DISTURBANCE AND COOL
FRONT PASSING THROUGH THE RIDGE COULD BRING A FEW SHOWERS AND STORMS
TO SOUTH CENTRAL SD THURSDAY. HIGHS THROUGH THE END OF THE WEEK WILL
BE IN THE 60S AND 70S...WITH THE WARMEST DAY LIKELY BEING SATURDAY.
COOLER AIR WILL PUSH INTO THE AREA SUNDAY AS AN UPPER TROUGH CROSSES
THE REGION. THIS WILL ALSO BRING CHANCES FOR PRECIPITATION EARLY
NEXT WEEK. LIKELY TO BEGIN BUILDING INTO THE WESTERN PORTIONS OF THE
AREA ON SUNDAY AS RIDGE SHIFTS TO THE EAST OF THE REGION.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...RED FLAG WARNING FROM 10 AM TO 6 PM MDT TUESDAY FOR BADLANDS
AREA-CENTRAL SOUTH DAKOTA PLAINS-NORTHERN BLACK HILLS-
NORTHWESTERN SOUTH DAKOTA PLAINS-SOUTH CENTRAL SOUTH DAKOTA-
SOUTHERN BLACK HILLS-SOUTHWESTERN SOUTH DAKOTA.
HIGH WIND WARNING UNTIL 6 PM MDT /7 PM CDT/ TUESDAY FOR BENNETT-
BUTTE-CUSTER CO PLAINS-FALL RIVER-HAAKON-HARDING-HERMOSA
FOOT HILLS-JACKSON-MELLETTE-NORTHERN FOOT HILLS-NORTHERN
MEADE CO PLAINS-PENNINGTON CO PLAINS-PERKINS-RAPID CITY-
SHANNON-SOUTHERN FOOT HILLS-SOUTHERN MEADE CO PLAINS-
STURGIS/PIEDMONT FOOT HILLS-TODD-TRIPP-ZIEBACH.
WY...HIGH WIND WARNING UNTIL 2 PM MDT TUESDAY FOR NORTHEASTERN CROOK-
NORTHERN CAMPBELL-SOUTHERN CAMPBELL-WESTERN CROOK-WESTON-
WYOMING BLACK HILLS.
RED FLAG WARNING FROM 10 AM TO 6 PM MDT TUESDAY FOR LOWER
ELEVATIONS OF CROOK AND WESTON COUNTIES-NORTHERN CAMPBELL-
SOUTHERN CAMPBELL-WYOMING BLACK HILLS.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
825 PM CDT WED MAR 28 2012
.UPDATE...
FLAT CUMULUS FROM EARLIER HAS DISAPPEARED. LOOKS LIKE A QUIET
NIGHT AHEAD. HAVE REMOVED THUNDER MENTION FROM THE FCST...TWEAKED
SKY GRIDS...AND CLEANED UP THE HWO. NO OTHER CHANGES ATTM.
&&
.PREV DISCUSSION... /ISSUED 634 PM CDT WED MAR 28 2012/
AVIATION...
S/SE BREEZES TONIGHT WILL BRING IMPROVING LOW-LEVEL MOISTURE TO
THE TERMINALS...WITH THE POSSIBILITY OF A LITTLE LIGHT FOG TOWARD
MORNING. WINDS WILL TURN SOUTHWESTERLY EARLY THURSDAY BUT REMAIN
ON THE LIGHT SIDE...BEFORE BACKING AGAIN BY LATE IN THE DAY. STRONG
HEATING AND A DRYLINE BISECTING THE REGION WILL BRING A LOW CHANCE
OF HIGH-BASED CONVECTION THURSDAY AFTN/EVNG. THUNDER CHANCES
APPEAR BEST AT CDS WHERE A CB REMARK WAS INCLUDED.
PREV DISCUSSION... /ISSUED 345 PM CDT WED MAR 28 2012/
SHORT TERM...
CONVOLUTED PATTERN IN PLACE ACROSS THE AREA GIVEN THE LARGE
CONVECTIVELY ENHANCED DISTURBANCE LOCATED TO OUR SE AND GENERAL WEAK
KINEMATICS ACROSS WEST TEXAS. THE DRYLINE HAS REMAINED FAIRLY
DIFFUSE THROUGH THE DAY ALTHOUGH AS OF 3 PM...SOME BACKING OF THE
SFC WINDS HAVE BEEN NOTED ALONG WITH SOME CUMULUS DEVELOPMENT FROM
ERN GAINES COUNTY THROUGH BRISCOE COUNTY. MEANWHILE...AN OUTFLOW BOUNDARY
FROM THE MCS IS MOVING TOWARD THE SRN ROLLING PLAINS WITH NEAR 60F
DEWPOINTS APPROACHING STONEWALL COUNTY. THERE IS LITTLE INDICATION OF A
CONVECTIVE SIGNAL IN ANY OF THE OBJECTIVE GUIDANCE FOR THE REMAINDER
OF THE AFTERNOON AND EVENING...ALTHOUGH RUC ANALYSIS SHOWS THE
ATMOSPHERE TO BE NEARLY UNCAPPED WITH ABOUT 500-1000 J/KG OF CAPE IN
MUCH OF THE ROLLING PLAINS. ALOFT...THERE IS ANOTHER WEAK WAVE
LOCATED IN NRN MX BUT THIS IS LIKELY TOO FAR REMOVED TO PROVIDE
SIGNIFICANT LIFT THIS EVENING. THUS THE ENVIRONMENT IS JUST
MARGINALLY SUPPORTIVE OF CONVECTIVE DEVELOPMENT...WITH WEAK
DRYLINE FORCING WE CAN/T RULE OUT A FEW ISOLD STORMS MAINLY ACROSS
THE SRN SPLNS AND ROLLING PLAINS. THE MAIN STORM THREAT WILL BE
STRONG DOWNDRAFT WINDS BUT IF A STORM CAN TAP INTO THE DEEPER
MOISTURE MOVING IN FROM THE SE THERE MAY BE A MARGINAL HAIL THREAT
AS WELL. THE DRYLINE SHOULD RETREAT THROUGH MOST OF THE FA
OVERNIGHT...WITH HOPEFULLY NO REPEAT OF THE NOCTURNAL MCS
INTERCEPTING OUR MOISTURE RETURN.
SOME LIGHT FOG IS AGAIN EXPECTED EARLY THU MORNING...FOLLOWED BY THE
DRYLINE MIXING INTO THE WESTERN ROLLING PLAINS BY EARLY AFTERNOON.
FCST SDNGS SHOW THAT THE AIRMASS SHOULD WARM UP NICELY IN THE DRY
AIR WITH AFTERNOON HIGHS APPROACHING 90F ACROSS THE SRN AND CENTRAL
SPLNS. GIVEN THE DEGREE OF SFC HEATING...A LITTLE MORE SHARPLY DEFINED
DRYLINE...AND INCREASED LARGE-SCALE ASCENT AS A SHORTWAVE APPROACHES
FROM THE WEST LATE IN THE DAY...WE THINK THE POTENTIAL WILL IMPROVE FOR
CONVECTIVE INITIATION ALONG THE DRYLINE THU AFTERNOON/EVE. FCST
SDNGS SHOW A DEEP DRY-ADIABATIC CONVECTIVE BOUNDARY LAYER ALONG THE
DRYLINE BY LATE AFTERNOON WITH NO INHIBITION...AND MODEST
MLCAPES...AROUND 1000 J/KG OR SO. IN ADDITION...SFC TO 6 KM SHEAR
WILL BE FAIRLY WEAK. THIS WILL LIMIT STORM ORGANIZATION...AND KEEP
STRONG WIND GUSTS AND MARGINALLY LARGE HAIL AS THE MAIN THREATS.
SOME UNCERTAINTY WITH TIMING OF THE LIFT AND DRYLINE LOCATION
PREVENT US FROM GOING HIGHER THAN SLIGHT CHANCE FOR NOW.
LONG TERM...
LARGELY UNEVENTFUL FORECAST FOR MUCH /IF NOT ALL/ OF THE EXTENDED
FORECAST AS MECHANISMS FOR ASCENT APPEAR HARD TO COME BY WITHIN
WEAK WESTERLY UPPER FLOW. EVEN THE RECENT DRYLINE IS PROGGED TO
REMAIN DIFFUSE DURING THE AFTERNOON TOMORROW AND FRIDAY AS IT
MIXES ALONG OR JUST EAST OF THE EDGE OF THE CAPROCK. VERTICAL
CIRCULATIONS WITH SUCH DRYLINES ARE GREATLY REDUCED...BUT WE HAVE
RETAINED SOME MENTION OF PRECIP OFF THE CAP THU NIGHT AS A SHALLOW
S/W TROF IN THE CENTRAL PLAINS GLANCES THE REGION. ALSO...SUBTLE
UPPER DIVERGENCE ASSOCIATED WITH AN APPROACHING UPPER WIND MAX
COULD OFFER A BIT MORE ASSISTANCE FOR ISOLATED THUNDER BEFORE
LIFT DIMINISHES LATE IN THE NIGHT. DESPITE A FRONTOLYSIZING COLD
FRONT DRIFTING SOUTH FROM THE PANHANDLE ON FRIDAY BEHIND THE S/W
TROF...SUBTLE RIDGING ALOFT THROUGHOUT THE PLAINS IS NOT BODING
WELL FOR STORM CHANCES FRIDAY AFTERNOON. NAM CONTINUES TO CONVECT
THIS DAY...ALTHOUGH THIS RECENT OVERZEALOUS NATURE OF THE MODEL
HAS NOT ENJOYED MUCH SUCCESS SO WE ARE QUITE DOUBTFUL OF ITS QPF.
APPROACH OF A PROGRESSIVE PACIFIC TROUGH BY THE WEEKEND WILL
SECURE STRONGER W-SWLY WINDS IN THE LOW-MID TROPOSPHERE.
SUBSEQUENT BOOST OF THICKNESSES SHOULD EASILY PUSH MOST AREA HIGHS
AOA 90 DEG AS THE DRYLINE MIXES NEAR OR JUST BEYOND OUR ERN
COUNTIES. TREND WITH THIS NEXT TROUGH HAS BEEN TO SLOW DOWN A BIT
AMONG THE GFS/ECMWF/GEFS MEAN AND THIS WOULD DELAY THE ARRIVAL OF
STRONGEST WINDS INTO THE PANHANDLE AND NWRN SOUTH PLAINS. BIGGEST
CHANGE HERE CONCERNS THE IMPENDING PACIFIC FRONT THAT IS NOW
PROGGED TO RID MUCH OF THE LONE STAR STATE OF GULF MOISTURE ON
MONDAY AS THE BASE OF THE TROF BECOMES -TILTED AND DIVES INTO THE
OZARKS. THIS WILL LIKELY DELAY THE RETURN OF MOISTURE MUCH LATER
THAN EARLIER FORECASTS SUGGESTED...SO A DRY START TO APRIL APPEARS
IN ORDER. TEMPS SHOULD PLUMMET BLO NORMAL FOR A CHANGE ON MONDAY
WITH GRADUAL MODIFICATION THEREAFTER.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 46 85 44 82 48 / 10 10 10 10 10
TULIA 50 87 48 85 49 / 10 20 10 10 10
PLAINVIEW 50 88 49 86 50 / 10 20 10 10 10
LEVELLAND 49 89 50 87 50 / 10 10 10 10 10
LUBBOCK 54 90 53 88 52 / 10 20 10 10 10
DENVER CITY 49 89 50 86 50 / 10 10 10 10 10
BROWNFIELD 50 90 52 86 51 / 10 20 10 10 10
CHILDRESS 58 89 56 88 54 / 10 20 20 10 10
SPUR 55 88 56 87 53 / 10 20 20 10 10
ASPERMONT 61 87 58 87 56 / 10 20 20 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
23/07
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
634 PM CDT WED MAR 28 2012
.AVIATION...
S/SE BREEZES TONIGHT WILL BRING IMPROVING LOW-LEVEL MOISTURE TO
THE TERMINALS...WITH THE POSSIBILITY OF A LITTLE LIGHT FOG TOWARD
MORNING. WINDS WILL TURN SOUTHWESTERLY EARLY THURSDAY BUT REMAIN
ON THE LIGHT SIDE...BEFORE BACKING AGAIN BY LATE IN THE DAY. STRONG
HEATING AND A DRYLINE BISECTING THE REGION WILL BRING A LOW CHANCE
OF HIGH-BASED CONVECTION THURSDAY AFTN/EVNG. THUNDER CHANCES
APPEAR BEST AT CDS WHERE A CB REMARK WAS INCLUDED.
&&
.PREV DISCUSSION... /ISSUED 345 PM CDT WED MAR 28 2012/
SHORT TERM...
CONVOLUTED PATTERN IN PLACE ACROSS THE AREA GIVEN THE LARGE
CONVECTIVELY ENHANCED DISTURBANCE LOCATED TO OUR SE AND GENERAL WEAK
KINEMATICS ACROSS WEST TEXAS. THE DRYLINE HAS REMAINED FAIRLY
DIFFUSE THROUGH THE DAY ALTHOUGH AS OF 3 PM...SOME BACKING OF THE
SFC WINDS HAVE BEEN NOTED ALONG WITH SOME CUMULUS DEVELOPMENT FROM
ERN GAINES COUNTY THROUGH BRISCOE COUNTY. MEANWHILE...AN OUTFLOW BOUNDARY
FROM THE MCS IS MOVING TOWARD THE SRN ROLLING PLAINS WITH NEAR 60F
DEWPOINTS APPROACHING STONEWALL COUNTY. THERE IS LITTLE INDICATION OF A
CONVECTIVE SIGNAL IN ANY OF THE OBJECTIVE GUIDANCE FOR THE REMAINDER
OF THE AFTERNOON AND EVENING...ALTHOUGH RUC ANALYSIS SHOWS THE
ATMOSPHERE TO BE NEARLY UNCAPPED WITH ABOUT 500-1000 J/KG OF CAPE IN
MUCH OF THE ROLLING PLAINS. ALOFT...THERE IS ANOTHER WEAK WAVE
LOCATED IN NRN MX BUT THIS IS LIKELY TOO FAR REMOVED TO PROVIDE
SIGNIFICANT LIFT THIS EVENING. THUS THE ENVIRONMENT IS JUST
MARGINALLY SUPPORTIVE OF CONVECTIVE DEVELOPMENT...WITH WEAK
DRYLINE FORCING WE CAN/T RULE OUT A FEW ISOLD STORMS MAINLY ACROSS
THE SRN SPLNS AND ROLLING PLAINS. THE MAIN STORM THREAT WILL BE
STRONG DOWNDRAFT WINDS BUT IF A STORM CAN TAP INTO THE DEEPER
MOISTURE MOVING IN FROM THE SE THERE MAY BE A MARGINAL HAIL THREAT
AS WELL. THE DRYLINE SHOULD RETREAT THROUGH MOST OF THE FA
OVERNIGHT...WITH HOPEFULLY NO REPEAT OF THE NOCTURNAL MCS
INTERCEPTING OUR MOISTURE RETURN.
SOME LIGHT FOG IS AGAIN EXPECTED EARLY THU MORNING...FOLLOWED BY THE
DRYLINE MIXING INTO THE WESTERN ROLLING PLAINS BY EARLY AFTERNOON.
FCST SDNGS SHOW THAT THE AIRMASS SHOULD WARM UP NICELY IN THE DRY
AIR WITH AFTERNOON HIGHS APPROACHING 90F ACROSS THE SRN AND CENTRAL
SPLNS. GIVEN THE DEGREE OF SFC HEATING...A LITTLE MORE SHARPLY DEFINED
DRYLINE...AND INCREASED LARGE-SCALE ASCENT AS A SHORTWAVE APPROACHES
FROM THE WEST LATE IN THE DAY...WE THINK THE POTENTIAL WILL IMPROVE FOR
CONVECTIVE INITIATION ALONG THE DRYLINE THU AFTERNOON/EVE. FCST
SDNGS SHOW A DEEP DRY-ADIABATIC CONVECTIVE BOUNDARY LAYER ALONG THE
DRYLINE BY LATE AFTERNOON WITH NO INHIBITION...AND MODEST
MLCAPES...AROUND 1000 J/KG OR SO. IN ADDITION...SFC TO 6 KM SHEAR
WILL BE FAIRLY WEAK. THIS WILL LIMIT STORM ORGANIZATION...AND KEEP
STRONG WIND GUSTS AND MARGINALLY LARGE HAIL AS THE MAIN THREATS.
SOME UNCERTAINTY WITH TIMING OF THE LIFT AND DRYLINE LOCATION
PREVENT US FROM GOING HIGHER THAN SLIGHT CHANCE FOR NOW.
LONG TERM...
LARGELY UNEVENTFUL FORECAST FOR MUCH /IF NOT ALL/ OF THE EXTENDED
FORECAST AS MECHANISMS FOR ASCENT APPEAR HARD TO COME BY WITHIN
WEAK WESTERLY UPPER FLOW. EVEN THE RECENT DRYLINE IS PROGGED TO
REMAIN DIFFUSE DURING THE AFTERNOON TOMORROW AND FRIDAY AS IT
MIXES ALONG OR JUST EAST OF THE EDGE OF THE CAPROCK. VERTICAL
CIRCULATIONS WITH SUCH DRYLINES ARE GREATLY REDUCED...BUT WE HAVE
RETAINED SOME MENTION OF PRECIP OFF THE CAP THU NIGHT AS A SHALLOW
S/W TROF IN THE CENTRAL PLAINS GLANCES THE REGION. ALSO...SUBTLE
UPPER DIVERGENCE ASSOCIATED WITH AN APPROACHING UPPER WIND MAX
COULD OFFER A BIT MORE ASSISTANCE FOR ISOLATED THUNDER BEFORE
LIFT DIMINISHES LATE IN THE NIGHT. DESPITE A FRONTOLYSIZING COLD
FRONT DRIFTING SOUTH FROM THE PANHANDLE ON FRIDAY BEHIND THE S/W
TROF...SUBTLE RIDGING ALOFT THROUGHOUT THE PLAINS IS NOT BODING
WELL FOR STORM CHANCES FRIDAY AFTERNOON. NAM CONTINUES TO CONVECT
THIS DAY...ALTHOUGH THIS RECENT OVERZEALOUS NATURE OF THE MODEL
HAS NOT ENJOYED MUCH SUCCESS SO WE ARE QUITE DOUBTFUL OF ITS QPF.
APPROACH OF A PROGRESSIVE PACIFIC TROUGH BY THE WEEKEND WILL
SECURE STRONGER W-SWLY WINDS IN THE LOW-MID TROPOSPHERE.
SUBSEQUENT BOOST OF THICKNESSES SHOULD EASILY PUSH MOST AREA HIGHS
AOA 90 DEG AS THE DRYLINE MIXES NEAR OR JUST BEYOND OUR ERN
COUNTIES. TREND WITH THIS NEXT TROUGH HAS BEEN TO SLOW DOWN A BIT
AMONG THE GFS/ECMWF/GEFS MEAN AND THIS WOULD DELAY THE ARRIVAL OF
STRONGEST WINDS INTO THE PANHANDLE AND NWRN SOUTH PLAINS. BIGGEST
CHANGE HERE CONCERNS THE IMPENDING PACIFIC FRONT THAT IS NOW
PROGGED TO RID MUCH OF THE LONE STAR STATE OF GULF MOISTURE ON
MONDAY AS THE BASE OF THE TROF BECOMES -TILTED AND DIVES INTO THE
OZARKS. THIS WILL LIKELY DELAY THE RETURN OF MOISTURE MUCH LATER
THAN EARLIER FORECASTS SUGGESTED...SO A DRY START TO APRIL APPEARS
IN ORDER. TEMPS SHOULD PLUMMET BLO NORMAL FOR A CHANGE ON MONDAY
WITH GRADUAL MODIFICATION THEREAFTER.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 46 85 44 82 48 / 10 10 10 10 10
TULIA 50 87 48 85 49 / 10 20 10 10 10
PLAINVIEW 50 88 49 86 50 / 10 20 10 10 10
LEVELLAND 49 89 50 87 50 / 10 10 10 10 10
LUBBOCK 54 90 53 88 52 / 10 20 10 10 10
DENVER CITY 49 89 50 86 50 / 10 10 10 10 10
BROWNFIELD 50 90 52 86 51 / 10 20 10 10 10
CHILDRESS 58 89 56 88 54 / 10 20 20 10 10
SPUR 55 88 56 87 53 / 20 20 20 10 10
ASPERMONT 61 87 58 87 56 / 10 20 20 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
23
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1150 PM CDT MON MAR 26 2012
.AVIATION...
SSE WINDS PUMPING MODESTLY MOISTER AIR INTO THE AREA WITH MODELS
SUGGESTING SOME LIGHT FOG REMAINS POSSIBLY TOWARD SUNRISE AT KLBB
WITH LESSER CHANCES AT KCDS. MAY SEE SOME MVFR CIGS DEVELOP
ALTHOUGH CONFIDENCE IS LOW ATTM.
&&
.PREV DISCUSSION... /ISSUED 904 PM CDT MON MAR 26 2012/
UPDATE...
FORECAST HAS BEEN UPDATED TO REMOVE PRECIPITATION MENTION FOR THE
REST OF THE EVENING. ISOLATED ACTIVITY HAS DECREASED OVER THE
REGION WITH THE LOSS OF DAYTIME HEATING AND LARGER AMOUNTS OF CIN
INCREASING.
PREV DISCUSSION... /ISSUED 641 PM CDT MON MAR 26 2012/
AVIATION...
A FEW HIGH-BASED SHOWERS TO MOVE ACROSS KLBB RIGHT AT BEGINNING OF
THE TAF PERIOD BUT NO THUNDER EXPECTED. VFR CONDITIONS EXPECTED
THROUGH THE PERIOD WITH SOME MINOR RESTRICTION TO VSBY POSSIBLE AT
KLBB AROUND 12Z.
PREV DISCUSSION... /ISSUED 330 PM CDT MON MAR 26 2012/
SHORT TERM...
THE DRYLINE HAS NOT MIXED AS FAR EAST AS IN THE PAST COUPLE OF DAYS
ALTHOUGH DEWPOINTS HAVE STARTED TO MIX OUT SOMEWHAT. SOME OF THE
12Z RUNS AND MORNING RUNS OF THE HRRR TRIED TO BREAK OUT SOME
CONVECTION BETWEEN LUBBOCK AND AMARILLO BUT THE LATEST RUNS OF THE
RUC AND HRRR HAVE SIGNIFICANTLY BACKED OFF OF THIS TREND OVER THE
FORECAST AREA AND ARE NOW FAVORING FURTHERING SOUTH. MODEL
SOUNDINGS IN THE RUC INDICATE A STRONG CAP IN PLACE BUT FAIRLY STEEP
LAPSE RATES ABOVE THIS FEATURE. LACK OF LOW LEVEL FOCUS AND
CONVERGENCE DO NOT FAVOR DEVELOPMENT OF CONVECTION OVER THE FORECAST
AREA...HOWEVER VISIBLE SATELLITE DOES SHOW SOME HIGH-BASED CUMULUS
DEVELOPMENT ALONG AND JUST EAST OF THE TX/NM STATE LINE. ALTHOUGH
CHANCES FOR STORMS ARE PRETTY SLIM...THEY ARE NON-NEGLIGIBLE AND
OPTED TO RETAIN LOW END CHANCE POPS ACROSS THE REGION. SHOULD ANY
STORMS INDEED DEVELOP...THE HIGH LAPSE RATES MAY PROVIDE A SMALL
WINDOW FOR SEVERE STORMS RESULTING IN STRONG WIND GUSTS AND MAYBE
SOME HAIL REPORTS.
LOW-LEVEL MOISTURE WILL ONCE AGAIN MIX BACK WEST OVERNIGHT AND
TEMPERATURE/DEWPOINT SPREADS BECOME FAIRLY LOW ON THE CAPROCK WHICH
MAY FAVOR SOME PATCHY LOW CLOUD/FOG DEVELOPMENT. THIS WILL ALSO
HELP TO HOLD MIN TEMPERATURES UP OVERNIGHT. TOMORROW SHOULD BE A
REPEAT OF TODAY...DRYLINE GRADIENT REMAINS WEST NEAR THE STATE
LINE...DECENT INSTABILITY LEVELS...WEAK WIND SHEAR...BUT A FAIRLY
STRONG CAP. HELD OFF INCREASING POPS TOMORROW AFTERNOON BUT WILL
NEED TO EVALUATE WITH THE 00Z MODEL RUNS TO SEE IF POPS NEED TO BE
INCREASED FOR THE EARLY AFTERNOON INTO THE SLIGHT CHANCE RANGE.
JORDAN
LONG TERM...
CHANCES OF SHOWERS AND THUNDERSTORMS DURING THE FIRST-HALF OF THE
EXTENDED PERIOD...WILL BE FOLLOWED BY DRIER CONDITIONS THEREAFTER.
TEMPS ARE EXPECTED TO REMAIN ABOVE NORM THROUGHOUT MOST OF THE
EXTENDED...WITH PERHAPS A SLIGHT COOL DOWN BY EARLY NEXT WEEK.
FORECAST SOLUTIONS DISPLAYED SLIGHT SW FLOW ALOFT TOMORROW NIGHT
THROUGH WEDNESDAY...AS THE DRYLINE APPEARS TO BE SPATIALLY
DISTRIBUTED NEAR THE STATE LINE/FAR WESTERN ZONES DURING THE SAID
PERIOD. HINTS OF CONVECTION DEVELOPING ALONG THE RETREATING LINE
TOMORROW NIGHT ACROSS THE UPPER TRANS-PECOS...AND SPREADING NORTH TO
ACROSS THE FAR SOUTHWESTERN ZONES IS SHOWN BY THE NAM AND GFS
SOLUTIONS. THIS COINCIDES WITH A RELATIVELY WEAK EMBEDDED
DISTURBANCE TRANSLATING ACROSS THE UPPER TRANS-PECOS. DURING THE DAY
ON WEDNESDAY...A CAPPING INVERSION IS EVIDENT VIA MODEL
SOUNDINGS...HOWEVER A GRADUAL STEEPING OF LAPSE RATES BY THE EVENING
HOURS MAY LEAD TO CI ALONG AND EAST OF THE DRYLINE...AS THE LOW
LEVEL JET INCREASES AND THE AFOREMENTIONED EMBEDDED IMPULSE SHIFTS NE
NEAR THE WESTERN ZONES. WILL THEREFORE MAINTAIN SLIGHT CHANCE POPS
MAINLY ACROSS SWRN ZONES TOMORROW NIGHT...WITH CHANCE POPS WEDNESDAY
EVENING.
BY THURSDAY...FLOW ALOFT WILL QUICKLY TRANSITION TO NEAR ZONAL
FLOW...ALBEIT WITH EMBEDDED IMPULSES. THE FIRST IMPULSE IS NOTED
ACROSS THE LOW ROLLING PLAINS/BIG COUNTRY THURSDAY EVENING WELL EAST
OF THE DRYLINE. THIS IMPULSE APPEARS TO BE THE SAME DISTURBANCE THAT
WAS LOCATED ACROSS THE UPPER TRANS-PECOS MENTIONED ABOVE. PWATS AOA
1.00 INCH...LITTLE TO NO CIN...SFC BASED CAPE BETWEEN 1000-2000 J/KG
AND A NEARBY UPPER LEVEL DISTURBANCE COULD LEAD TO STORMS /POSSIBLY
STRONG/ ACROSS THE EASTERN ZONES. THE NAM AND ECMWF ARE MOST
AGGRESSIVE WITH THIS POSSIBILITY AS CI COMMENCES THURSDAY
AFTERNOON...PERSISTING INTO THE EVENING HOURS WITH THE ADDITION OF
DEVELOPING CONVECTION ALONG THE DRYLINE NEAR THE STATE LINE AS THE
LLJ INCREASES. THE GFS ON THE OTHER-HAND HAS BEST PRECIP DURING THE
EVENING HOURS ACROSS THE EAST...WITH HINTS OF LIGHT QPF VALUES ALONG
THE DRYLINE WEST. WILL INCREASE POPS TO CHANCE CAT ACROSS THE SE
THURSDAY NIGHT WITH SLIGHT CHANCE POPS ELSEWHERE ATTM...DUE TO MODEL
CONSISTENCY /AS OF LATE/ IN SHOWING BEST PRECIP ACROSS THE SE
NEAREST TO THE EMBEDDED DISTURBANCE. FRIDAY THE DRYLINE WILL PUSH
EAST TO LOCALES ON THE CAPROCK...AS ANOTHER DISTURBANCE IN THE FLOW
ALOFT MOVES EAST ACROSS THE SOUTH PLAINS FRIDAY MORNING/AFTERNOON.
PWATS AOA 0.65 INCHES ALONG AND EAST OF THE DRYLINE IN ADDITION TO
AN APPROACHING DISTURBANCE...MAY LEAD TO STORM DEVELOPMENT. BY THE
END OF THE WEEKEND/BEGINNING OF NEXT WEEK...UNCERTAINTY SETS IN AS
MODELS DISAGREE WITH WHAT TO DO WITH A PACIFIC UA LOW. THE GFS TREKS
THE UA LOW ESE ACROSS THE PANHANDLES/CENTRAL PLAINS SUNDAY
NIGHT/MONDAY MORNING ...AND THUS INDUCE RATHER BREEZY WESTERLY SFC
WINDS ON SUNDAY THUS PUSHING THE DRYLINE EAST OF THE CWA. BY
MONDAY...A BREEZY NORTHERLY FROPA WILL OCCUR ALTHOUGH MODEL
SOLUTIONS MAINTAIN BEST PRECIP WELL EAST OF THE CWA...COINCIDING
WITH DRYLINE FEATURE. THE ECMWF ON THE OTHER HAND MOVES THE UA LOW
WELL NORTH OF THE REGION TO ACROSS THE NORTHERN ROCKIES ON SUNDAY
GIVING WAY TO LITTLE FANFARE FOR THE SOUTHERN PLAINS. WILL THEREFORE
OPT TO MAINTAIN SILENT POPS BEYOND FRIDAY ATTM...AS THE ANALYSIS OF
FUTURE MODEL RUNS FOR CONSISTENCY IS HIGHLY DESIRED.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 46 81 47 80 48 / 10 10 10 20 20
TULIA 54 84 51 82 51 / 10 10 10 20 20
PLAINVIEW 56 83 51 82 52 / 10 10 20 20 30
LEVELLAND 57 84 52 84 52 / 10 10 20 20 30
LUBBOCK 56 83 54 84 54 / 10 10 20 20 30
DENVER CITY 57 84 52 82 53 / 10 10 20 20 30
BROWNFIELD 57 83 53 83 53 / 10 10 20 20 30
CHILDRESS 56 85 56 86 56 / 10 10 20 20 30
SPUR 57 84 55 83 56 / 10 10 20 20 30
ASPERMONT 56 85 57 83 58 / 10 10 20 20 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/99/99
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
337 PM CDT TUE MAR 27 2012
.VERY SHORT TERM...TONIGHT AND WEDNESDAY.
TONIGHT - CONFIDENCE...MEDIUM
POTENT/COMPACT 46 UNIT VORT MAX ROTATING NORTHEAST INTO CANADA. ANY
VORTICITY ADVECTION THIS FAR SOUTH IS QUITE CHANNELIZED AND LITTLE
CONTRIBUTION TO VERTICAL MOTION. IN THE LOWER LEVELS...CORE OF
STRONG 850 JET PEELS EAST THIS EVENING. GUSTS HAVE BEEN NEARING THE
ADVISORY CRITERIA AT TIMES. WILL BE CLOSE IN SOME AREAS BUT WILL
HOLD OFF ON ISSUANCE AT THIS POINT. SURFACE MOIST AXIS LEANING INTO
CWA AHEAD OF COLD FRONT. BEST INSTABILITY HAS BEEN SOUTH PER SPC
MESO ANALYSIS. SOME DESTABILIZATION EXPECTED INTO SRN WI. HOWEVER
BETTER DEW POINTS ARE POOLING TO OUR SOUTH WITH MOIST AXIS GETTING
PINCHED A BIT INTO SW WI. SOME LOW LEVEL CONVERGENCE COULD STILL
INITIATE A CELL OR TWO INTO THE EARLY EVENING HOURS. CU THUS FAR HAS
BEEN WELL CAPPED BUT WATCHING SW/SC WI IN EXISTING CU FIELD FOR ANY
POSSIBLE DEVELOPMENT. THE HRRR IS SUGGESTING SOME ISOLATED
DEVELOPMENT. MAXES LIKELY TO BE REACHED THIS EVENING AS 70S READY TO
SPILL INTO SC WI. SOME MODIFICATION IN THE EAST WITH LOSS OF
HEATING BUT STILL AN EVENING MAX LIKELY.
WEDNESDAY - CONFIDENCE...MEDIUM
LINGERING 500 MILLIBAR CYCLONIC FLOW EARLY GRADUALLY GIVES WAY TO
MORE RIDGING WITH TIME. SURFACE HIGH ALSO DRAWS CLOSER AS THE DAY
WEARS ON HELPING TO EASE BACK ON THE WINDS A BIT. CU RULE POINTS TO
GREATER COVERAGE CU IN THE NE CWA...PER COMBO OF RH
PROGS...BUFKIT...PROGGD PROXIMITY OF UPPER CYCLONIC FLOW.
.SHORT TERM...WEDNESDAY NIGHT THROUGH FRIDAY NIGHT.
WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE HIGH.
UPPER RIDGING KEEPS THIS PERIOD DRY. UPPER LEVEL NORTHWEST FLOW WITH
COLD ADVECTION DROPPING 850 MB AND 925 MB TEMPERATURES INTO THE
SINGLE DIGITS ABOVE 0C...WITH 0C OR BELOW ACROSS THE NORTHEAST.
LIGHT WINDS AND CLEAR SKIES WITH HIGH PRESSURE OVERHEAD LEADS TO
LOWS IN THE LOWER TO MIDDLE 30S. KEEPING THE AREAS OF FROST IN THE
COLDEST LOCATIONS WITH PATCHY FROST ELSEWHERE.
DRY AIR STREAMS INTO REGION WITH PERSISTENT NORTHEAST TO EAST FLOW
AROUND HUDSON BAY HIGH...WITH LOW TO MID 20 DEW POINTS IN THE EAST
AND LOW TO MID 30S WEST. SOME UPWARD MODIFICATION OF 925 MB
TEMPERATURES BRINGS UPPER 50S HIGH IN THE FAR SOUTHWEST...WITH LOW
TO MID 50S ELSEWHERE EXCEPT MID TO UPPER 40S IN THE FAR EAST NEARER
THE LAKE.
THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE MEDIUM.
SOME TIMING CONCERNS RELATED TO DIFFERING CONFIGURATIONS AMONG
MODELS WITH TROUGH CROSSING THE WESTERN GREAT LAKES. HAVE DIVIDED
POPS THIS PERIOD INTO 6-HOURLY GROUPS TO HIGHLIGHT THE 06Z TO 18Z
FRIDAY TIME FRAME AS MOST LIKELY FOR PRECIPITATION.
CLOUDS...PRECIPITATION THAT WILL BE MAINLY SHOWERS...AND EASTERLY
FLOW AROUND WEAK SURFACE LOW PASSING SOUTH WILL KEEP HIGH
TEMPERATURES SIMILAR TO THURSDAY.
.LONG TERM...SATURDAY THROUGH TUESDAY. FORECAST CONFIDENCE LOW TO
MEDIUM.
ANOTHER SHORT WAVE KEEPS POPS IN THE FORECAST FOR FRIDAY
NIGHT...THEN ZONAL FLOW BUCKLES TO THE SOUTHWEST AHEAD OF DEEPENING
WESTERN TROUGH. RISING TEMPERATURES INTO THE 60S FOR SATURDAY
AND 70S SUNDAY...WITH MID TO UPPER 60S ALONG THE LAKE AND NORTHEAST.
CYCLOGENESIS IN THE PLAINS SUNDAY AFTERNOON AND EVENING...WITH LOW
CONTINUING TO DEEPEN AS IT MOVES TOWARD WESTERN GREAT LAKES BRINGING
THE WARM AND BREEZY CONDITIONS.
UPPER SYSTEM EITHER CUTS-OFF PER GFS...OR REMAINS AN OPEN WAVE PER
LATEST ECMWF MONDAY NIGHT INTO TUESDAY...SO FOLLOWED CONSENSUS BLEND
WHICH BRINGS CHANCES FOR SHOWERS AND/OR THUNDERSTORMS THROUGH THE
REST OF THE EXTENDED...THOUGH NO ALL DAY RAINS...WITH TEMPERATURES
COOLING INTO THE 50S FOR TUESDAY.
&&
.AVIATION/00Z TAFS/...STILL LOOKS LIKE A MAINLY DRY AND VFR FROPA. CONVECTION
ISOLATED AT BEST WITH ANY SVR POTENTIAL TO OUR SOUTH PER SWODY1.
MAIN STORY WILL BE WINDY CONDITIONS WITH SOUTHWEST 850 JET GRADUALLY
SHIFTING AWAY WITH WESTERLY JET TAKING HOLD POST FROPA. SUBSIDENCE
TAKES HOLD SO EXPECT DECENT MIXING INTO THE EVENING HOURS EVEN AFTER
PEAK MIXING DUE TO INSOLATION. COLD ADVECTION PLUS PROXIMITY TO
FRINGE OF UPPER CYCLONIC SUGGESTS SOME CU DEVELOPMENT FOR
WEDNESDAY...WITH GREATEST COVERAGE LIKELY IN NE CWA.
&&
.MARINE...ASED ON TRENDS DECIDED TO EXTEND THE GALE INTO THE
EVENING HOURS AS LINGERING WARM SECTOR SOUTHWEST 850/925 JET MAX
GRADUALLY PEELS EAST. SMALL CRAFT ADVISORY WILL BE NEEDED ONCE THE
GALE EXPIRES.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...GALE WARNING UNTIL 10 PM CDT THIS EVENING FOR LMZ643>646.
&&
$$
TONIGHT/WEDNESDAY AND AVIATION/MARINE...COLLAR
WEDNESDAY NIGHT THROUGH TUESDAY...REM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
300 PM CDT TUE MAR 27 2012
.SHORT TERM...TONIGHT AND WEDNESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
MOVING NE OVER FAR NORTHERN MINNESOTA...AND ITS ASSOCIATED COLD
FRONT NOW CROSSING THE MINNESOTA/WISCONSIN BORDER. NO PRECIP ALONG
THE COLD FRONT SO FAR THROUGH EARLY THIS AFTERNOON WHERE
TEMPERATURES HAVE RISEN INTO THE MIDDLE TO UPPER 60S OVER WESTERN
WISCONSIN. MUCH COOLER OVER NE WISCONSIN WHERE CLOUD COVER HAS KEPT
TEMPERATURES IN THE 40S AND 50S. THE BIGGEST STORY SO FAR HAS BEEN
THE GUSTY WINDS...WHICH SEEM TO BE PEAKING ABOUT NOW. HAVE SEEN
SEVERAL REPORTS ALONG THE LAKESHORE FROM SHEBOYGAN TO SISTER BAY OF
GUSTS TO 45 MPH...AND A FEW REPORTS IN THE 50S AT THE KEWAUNEE AND
ALGOMA MARINE STATIONS. INLAND LOCATIONS HAVE BEEN CONSISTENTLY
GUSTING BETWEEN 35 AND 40 MPH. HAVE BEEN TREATING THE STRONG GUSTY
WINDS ALONG THE LAKESHORE AS A LOCALIZED PHENOMENA...AND USING SPS/S
TO HIGHLIGHT THE THREAT. BEHIND THE FRONT...SEE A PRETTY SOLID
STRATO-CU DECK OVER MINNESOTA AND THE DAKOTAS WITHIN A COLDER
AIRMASS. FORECAST CONCERNS INCLUDE WIND THROUGH THE EVENING...THEN
CLOUDS AND TEMPS.
TONIGHT...OCCLUDED LOW PRESSURE OVER NORTHERN MINNESOTA WILL TRACK
ENE ACROSS NORTHERN LAKE SUPERIOR TONIGHT. ASSOCIATED COLD FRONT
WILL DROP ACROSS THE SE 2/3RDS OF THE FORECAST AREA THIS
EVENING...SHIFTING OUR WINDS FROM THE SOUTH TO THE WEST. WILL
PROBABLY SEE GUSTY WINDS ALONG THE LAKESHORE THROUGH EARLY THIS
EVENING AND SHOULD DIMINISH THEREAFTER ONCE THE FRONT MOVES THROUGH.
AM TEMPTED TO PULL OUT POPS TONIGHT GIVEN A LACK OF INSTABILITY AND
CU OF LITTLE VERTICAL EXTENT UPSTREAM. WILL WAIT UNTIL THE LAST
MINUTE TO LOOK AT THE LATEST TRENDS BEFORE YANKING POPS OUT. SHOULD
SEE A PERIOD OF CLEARING WORK ACROSS THE AREA ALONG AND BEHIND THE
FRONT BEFORE WRAP AROUND STRATO-CU DIVES IN FROM NW TO SE. DEEPER
MOISTURE OVER LAKE SUPERIOR AND THE UPPER PENINSULA COMBINED WITH
UPSLOPE FLOW MAY LEAD TO SCT SHOWER ACTIVITY OVER N-C WISCONSIN AS
THE STRATO-CU WORKS INTO THE AREA. OTHERWISE...DRY CONDITIONS ARE
EXPECTED ELSEWHERE UNDER COLD ADVECTION. LOWS RANGING FROM THE
UPPER 30S NORTH TO MIDDLE 40S SOUTH.
WEDNESDAY...CYCLONIC FLOW WILL HANG AROUND WITH NW WINDS COLD
ADVECTING THE ENTIRE DAY. STEEP LOW LEVEL LAPSE RATES COMBINED WITH
AMPLE MOISTURE UP TO AROUND 800MB SUPPORTS A WIDESPREAD BKN/OVC
STRATO-CU FIELD HANGING AROUND THROUGH THE AFTERNOON. SCT LIGHT
SHOWER ACTIVITY WILL LIKELY CONTINUE THROUGH AT LEAST THE MORNING
HOURS OVER N-C WISCONSIN. LOOKED INTO SNOW POSSIBILITIES...BUT
MOISTURE DOES NOT LOOK LIKE IT WILL EXTEND HIGH ENOUGH INTO THE COLD
AIR FOR SNOWFLAKES TO BE INTRODUCED INTO THE CLOUDS. WITH COLD
ADVECTION AND CLOUD COVER...KNOCKED A DEGREE OR TWO OFF THE HIGH
TEMPS...WHICH WOULD PLACE THEM INTO THE LOWER 40S NORTH TO MIDDLE
50S SOUTH.
.LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY.
FROST AND FREEZE POTENTIAL CERTAINLY THERE FOR WEDNESDAY NIGHT AS
SURFACE HIGH DRIFTS BY TO THE NORTH AND UPPER RIDGE APPROACHES
FROM THE NORTHERN PLAINS. RECORD WARMTH EARLIER THIS MONTH HAS
STARTED THE DEVELOPMENT OF SOME VEGETATION WHICH MAY BE THREATENED
BY THIS FROST OR FREEZE.
THEN A RATHER ACTIVE PERIOD OF WEATHER EXPECTED WITH SOME RATHER
ABRUPT SWINGS POSSIBLE LATER THIS WEEK AND EARLY NEXT WEEK AS HIGH
AMPLITUDE NEGATIVELY TILTED TROUGH FORECAST TO LIFT NORTHEAST FROM
THE SOUTHERN AND CENTRAL PLAINS. TWO MUCH WEAKER UPPER TROUGHS
MOVE BY THURSDAY NIGHT AND EARLY FRIDAY AND AGAIN SATURDAY. THESE
SHOULD PRODUCE SOME SHOWERS AND ELEVATED THUNDERSTORMS IN THE
SOUTH AND RAIN OR SNOW SHOWERS IN THE NORTH. UPPER RIDGE SHARPENS
SATURDAY AND SUNDAY AND SHOULD RESULT IN MORE VERY WARM
TEMPERATURES SATURDAY SUNDAY AND MONDAY. A WARM FRONT LIFTING
NORTH SUNDAY COULD BE ACCOMPANIED BY SHOWERS AND THUNDERSTORMS
WITH SOME POSSIBILITY OF MARGINALLY SEVERE HAIL.
DEEPENING SURFACE LOW MOVING FROM THE CENTRAL PLAINS TO NORTHERN
WISCONSIN SHOULD BRING 60F DEW POINTS INTO SOUTHERN WISCONSIN WITH
POSSIBLE SEVERE STORMS AS TRIPLE POINT LOW MOVES ACROSS THE AREA.
THEN SHARPLY COLDER TUESDAY WITH RAIN AND SNOW SHOWERS.
&&
.AVIATION...A SURFACE WARM FRONT WILL LIFT INTO CENTRAL AND
EAST-CENTRAL WISCONSIN THIS AFTERNOON...WHICH WILL BE FOLLOWED
CLOSELY BY THE PASSAGE OF A COLD FRONT LATE THIS AFTERNOON INTO THIS
EVENING. A PERIOD OF MVFR CIGS IS EXPECTED OVER CENTRAL AND
NORTH-CENTRAL WISCONSIN THROUGH MID-AFTERNOON BEFORE CLEARING WORKS
IN FROM THE WEST. NOT ANTICIPATING MUCH OF A SHOWER AND
THUNDERSTORM THREAT THIS AFTERNOON...SO REMOVED FROM THE FORECAST.
BEHIND THE COLD FRONT...MVFR CIGS WILL RETURN OVER CENTRAL AND
NORTH-CENTRAL WISCONSIN...AND POSSIBLY INTO NORTHEAST WISCONSIN VERY
LATE TONIGHT OR INTO TOMORROW MORNING. LEFT CIGS AT LOW END VFR AT
GRB/ATW FOR NOW. WIND SHEAR WILL CONTINUE TO BE PRESENT TONIGHT
THROUGH SHOULD ABATE BY MORNING. MVFR CLOUDS TO LAST THROUGH THE
MORNING...BUT SHOULD SEE THEM LIFT IN THE AFTERNOON...POSSIBLY TO
VFR OVER CENTRAL WISCONSIN.
MPC
&&
.MARINE...THOUGH STABILITY WILL BE INCREASING LATER THIS
AFTERNOON...STRONG SOUTHEAST TO SOUTH WINDS CONTINUE TO IMPACT THE
LAKESHORE WITH GUSTS MEASURED BETWEEN 45 AND 50 KTS AT KEWAUNEE AND
ALGOMA. SINCE IMPACTS FROM STABILITY HAVE BEEN NON-EXISTENT SO
FAR...WILL EXTEND THE GALE WARNING THROUGH 03Z AFTER COORDINATION
WITH OFFICES TO THE SOUTH. ONCE THE GALE IS OVER...WINDS WILL SWING
AROUND TO THE WEST BEHIND A COLD FRONT THIS EVENING AND
DIMINISH...THOUGH A SMALL CRAFT ADVISORY WILL BE NEEDED DUE
LINGERING WAVES THROUGH THE REST OF THE NIGHT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/RDM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1158 PM CDT MON MAR 26 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT
230 PM CDT MON MAR 26 2012
FORECAST CONCERNS FOCUS ON POTENTIALLY STRONG WINDS...STORM AND
GRADIENT RELATED...TUE/TUE NIGHT.
A UPPER LEVEL SHORTWAVE TROUGH WAS DRIVING ACROSS THE SOUTHERN
ROCKIES...PER LATEST WATER VAPOR SATELLITE IMAGERY...WITH THE 26.12Z
NAM AND GFS TAKING THIS FEATURE ACROSS NORTHERN MN BY 00Z WED. THE
SYSTEM COMES IN STACKED WITH ITS ASSOCIATED SFC LOW...TAKING ITS
NORTH-SOUTH COLD FRONT TO THE MISSISSIPPI RIVER BY 18-21Z TUE...AND
THEN ACROSS EASTERN WI BY 03Z WED.
BEFORE THE HEART OF THIS WEATHER SYSTEM MOVES IN THERE WILL BE
STRONG LOW LEVEL 925-850 MB WARM AIR ADVECTION ACROSS THE REGION
TONIGHT INTO TUE MORNING...ALONG WITH ADVECTION ON THE ISENTROPIC
SFCS. STRONG 850 MB MOISTURE TRANSPORTS AHEAD OF THE FRONT...WITH A
60+ KT LOW LEVEL JET NOSING INTO NORTHERN MN TONIGHT...AND
CONTINUING TO POINT TO FAR NORTHERN PORTIONS OF THE REGION.
HOWEVER...SATURATION COULD BE A CONCERN A NORTH-SOUTH RUNNING
X-SECTIONS AND BUFKIT SOUNDINGS KEEPS THE DEEPER MOISTURE FARTHER
NORTH...WITH SATURATION CONFINED UNDER 700 MB FOR THE SOUTHERN 1/2
OF THE FORECAST AREA.
THE COMBINATION OF THE LOW LEVEL THERMODYNAMICS...LOW LEVEL
JET/MOISTURE TRANSPORT...AND DEEPER SATURATION MAKES PCPN MORE
LIKELY ACROSS THE NORTHERN REACHES OF THE REGION TONIGHT.
LOCALLY...MOSTLY NORTH OF A WABASHA MN TO BLACK RIVER FALLS WI LINE.
HOWEVER...CURRENT 88-D IMAGERY HAS AN EXPANDING BAND OF SHOWERS
WHICH HAVE BLOSSOMED ON THE LEADING EDGE OF THE LOWER LEVEL MOISTURE
TRANSPORT. RUC13 WOULD SLIDE THIS BAND OF PCPN ACROSS THE FORECAST
AREA THIS EVENING...WITH THE MAIN PCPN FOCUS THEN TURNING FARTHER
NORTH. WILL WORK PCPN CHANCES WITH THIS IN MIND
TUESDAY THE FRONT WILL BE MOVING ACROSS THE AREA...BUT NOT A LOT OF
FRONTOGENETIC LIFT ACCORDING TO THE NAM/GFS. SOME MUCAPE OF 250-500
J/KG WORKS INTO NORTHEAST IA/SOUTHWEST WI AHEAD OF THE BOUNDARY. 0-3
KM SHEAR CONTINUES TO BE STRONG AT 40-45 KTS FROM THE WEST. BUFKIT
SOUNDINGS INDICATE SOME DRYING IN THE SUB CLOUD LAYER...INVERTED-V
SHAPE. EXPECT SOME SHOWERS TO STORMS TO DEVELOP ALONG AND JUST AHEAD
OF THE FRONT...AND IF ANY WOULD BECOME STRONG TO SEVERE...DAMAGING
WINDS WOULD BE THE MAIN CONCERN. EVEN PERKY SHOWERS WILL BE ABLE TO
ACCELERATE SOME WIND TO THE SFC...WITH 40 MPH WIND GUSTS CERTAINLY
POSSIBLE.
SPEAKING OF THE WINDS...THE PRESSURE GRADIENT WILL CONTINUE TO
TIGHTEN TONIGHT...STAYING THAT WAY INTO TUESDAY NIGHT. 60 KT WINDS
BY 2000 FT...BUT ABOVE THE INVERSION. POST THE FRONT THOUGH...MIXING
IS DEEPER AND ALTHOUGH THE LOW LEVEL WIND FIELD WON/T BE AS
STRONG...THE POTENTIAL FOR HIGHER WIND GUSTS EXISTS. DON/T BELIEVE A
WIND ADVISORY WILL BE NEEDED AT THIS TIME...BUT IT COULD BE CLOSE
ACROSS THE OPEN AND UNSHELTERED AREAS OF SOUTHEAST MN/NORTHEAST IA
TUE AFTERNOON/EVENING.
HIGH PRESSURE WILL WORK ACROSS THE REGION WED NIGHT...BRINGING
MOSTLY CLEAR SKIES AND LIGHTER WINDS. IN ADDITION...COLDER...BUT
SEASONABLE AIR WILL RETURN...WITH RADIATIONAL COOLING HELP
TEMPERATURES FALL OFF INTO THE MID TO LOWER 30S BY DAYBREAK THU.
PATCHY TO AREAS OF FROST LOOK LIKELY. CONSIDERING THE RECENT VERY
WARM TEMPS AND EARLY START TO THE GROWING SEASON...COLD DAMAGE COULD
OCCUR TO TENDER VEGETATION AND COLD SENSITIVE PLANTS. A FROST
ADVISORY MAY BE NEEDED FOR WEDNESDAY NIGHT.
.LONG TERM...FRIDAY THROUGH MONDAY
230 PM CDT MON MAR 26 2012
GFS AND ECMWF IN PRETTY GOOD AGREEMENT WITH RETURN FLOW POST A HIGH
INTERACTING WITH A SHORTWAVE TROUGH A LOFT TO TRIGGER AREAS OF
SHOWERS AND ISOLATED THUNDERSTORMS THU NIGHT-FRI. BOTH MODELS THEN
FAVOR ANOTHER SHORTWAVE TROUGH SLIDING ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY FRI NIGHT...POSSIBLY INTO SAT. SOME DIFFERENCES WITH
TIMING...POSITIONING AND STRENGTH...BUT THERE DOES LOOK TO BE SOME
PCPN CHANCES IN THIS TIME FRAME. A STRONGER TROUGH AND SFC COLD
FRONT COULD THEN IMPACT THE AREA SUNDAY INTO MONDAY.
AGAIN...DIFFERENCES IN THE MODELS...ALTHOUGH THE SENSIBLE WEATHER IS
SIMILAR. SUNDAY NIGHT APPEARS TO BE THE MOST FAVORABLE TIME FOR
CONVECTION ALONG THE FRONT TO MOVE IN.
&&
.AVIATION...THROUGH 00Z WEDNESDAY
1158 PM CDT MON MAR 26 2012
THE RAIN AREA HAS SHIFTED EAST OF THE TAF LOCATIONS FOR THE TIME
BEING...WITH WIND THE MAIN CONCERN THROUGH THE NIGHT AND INTO
TUESDAY. SOUTHEAST WIND BLOWING AT A GOOD CLIP ALREADY...AND GRADIENT
IS TIGHTENING AS LOW CONTINUES TO DEEPEN TO OUR WEST. EXPECT
SOUTHEAST WIND 15 TO 25 KTS WITH GUSTS UP AROUND 30...ESPECIALLY OVER
THE HIGHER OPEN TERRAIN OUT NEAR KRST OVERNIGHT. FOR KLSE...SEE SOME
POTENTIAL FOR LLWS AS SOUTHEAST WINDS AT THE SURFACE...ENHANCED BY
THE VALLEY EFFECT REMAIN CUT OFF FROM THE HIGHER SPEEDS ALOFT.
COMBINE THE SPEED CHANGE WITH THE SWITCH TO SOUTHWEST ABOVE 2000 FT
AND FEEL IT IS WARRANTED TO ALERT PILOTS TO THAT WITH WIND SHEAR IN
THE TAF. MODELS AND REGIONAL RADAR VAD WIND PROFILES INDICATING AS
MUCH AS 70 KTS AT 2 TO 3 KFT. MORE OF THIS WILL MIX DOWN DURING THE
DAYLIGHT HOURS...ESPECIALLY AS SKIES CLEAR AND WARMING ALLOWS FOR
DRY ADIABATIC LAPSE RATES.
THERE IS STILL A SMALL CHANCE FOR SOME CONVECTION TO DEVELOP ALONG
THE TROUGH OR FRONT AS THEY PASS BETWEEN 10Z AND 18Z...BUT TOO
LITTLE TO INCLUDE AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
230 PM CDT MON MAR 26 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION.....MW
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
332 AM CDT THU MAR 29 2012
...UPDATE TO LONG TERM AND FIRE WEATHER SECTION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 217 AM CDT THU MAR 29 2012
.SYNOPSIS...
ISSUED AT 217 AM CDT THU MAR 29 2012
00Z 300 HPA SYNOPTIC MAP ANALYSIS SHOWS A 95 KT JET PUSHING ASHORE ACROSS
THE PACIFIC NORTHWEST IN ASSOCIATION WITH BROAD TROUGH EXTENDING FROM
THE PACNW TO THE NORTHERN ROCKIES. WEAKER 50 TO 75 KT BROAD W/NW FLOW
EXTENDED ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION.
THE 500 HPA FLOW PATTERN SHOWED THE TROUGH AXIS IN ASSOCIATION WITH
THE AFOREMENTIONED JET STREAK FROM THE NORTHEAST PACIFIC AND SE ACROSS
THE GREAT BASIN. LOWER IN THE ATMOSPHERE...NAMELY THROUGH THE 700 AND
850 HPA LAYERS, THE MOST INTERESTING ITEM WAS WARM AND DRY FLOW IN
THE LEE OF THE ROCKIES. AT THE SFC, MSAS SURFACE PRESSURE ANALYSIS SHOWED
A WEAK LOW PRESSURE CENTER ACROSS SE COLORADO. A WARM FRONT WAS EXTENDING
FROM THIS FEATURE ACROSS CENTRAL KANSAS. RICH MOISTURE AS MARKED BY
DEWPOINTS IN THE 60S DEG F EXTENDED ACROSS SOUTH CENTRAL KANSAS.
THIS MORNING:
THE MAIN ITEM OF CONCERN DURING THE MORNING PERIOD IS THE LIKELIHOOD
FOR DENSE FOG. HRRR AND MOS IS SUGGESTING THE GREATEST POTENTIAL FOR
DENSE FOG ACROSS WEST CENTRAL KANSAS THIS MORNING. THIS IS ALSO REFLECTED
IN 00Z NAM BUFKIT DATA. THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE
DEWPOINTS (LOW 50S DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A
WARM FRONT THAT WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
TODAY:
THE FOG SHOULD DISSIPATE/MIX OUT BY MID MORNING. THE REST OF THE SENSIBLE
WEATHER FOR TODAY WILL BE FAIRLY TRANQUIL. A BROAD UPPER LEVEL SHORTWAVE
TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS TODAY. SW KANSAS WILL BE
ON THE SOUTHEASTERN FRIDGES OF THE 400 HPA PV ANOMALY TODAY. AS A RESULT
OF THE AFOREMENTIONED UPPER LEVEL DYNAMICS SLIDING EAST THROUGH THE
DAY, THE RESULTANT SURFACE LOW WILL CONTINUE TO SLIDE TO THE EAST ACROSS
NORTHERN KANSAS AS WELL. A BIT OF DOWNSLOPE AND MIXING ACROSS THE SOUTHWESTERN
COUNTIES THIS AFTERNOON WILL PROVIDE VERY WARM TEMPERATURES NEAR THE
OKLAHOMA BORDER. EXPECT MID 80S DEG F IN THIS AREA. FURTHER NORTH, ONLY
LOOKING FOR UPPER 70S DEG F TO AROUND 80 DEG F AS A WEAK COLD FRONT
MOVES THROUGH EARLIER IN THE DAY. THE DRYLINE WITH UPPER 50S TO LOWER
60S DEG F DEWPOINTS WILL MIX EAST TODAY. THIS DRYLINE SHOULD BE LOCATED
ACROSS SOUTH CENTRAL KANSAS BY THIS AFTERNOON.
TONIGHT:
EVENTUALLY THE PACIFIC FRONT FOLLOWING BEHIND THE DRYLINE WILL CATCH
UP CLOSER TO THE DRYLINE. HAVE DISCOUNTED THE 00Z GFS SOLUTION AS THIS
MODEL SEEMS TO BE SUFFERING FROM BOUNDARY LAYER MOISTURE PROBLEMS AND
THE RESULTANT QPF LOOKS A LITTLE OVERZEALOUS. MAINLY STUCK WITH THE
00Z NAM AND 00Z WRF-NMM FOR POPS THIS EVENING. CONFINED POPS MAINLY ACROSS
SOUTH CENTRAL KANSAS AS TEMPERATURES IN THE 80S DEG F COMBINED WITH
NEAR 60 DEG F DEWPOINTS WILL CREATE ENOUGH SBCAPE IN THE 2000-2500 J/KG
RANGE SOUTH CENTRAL KANSAS. FORECAST SOUNDINGS SHOW CONSIDERABLE CINH
REMAINING ACROSS SC KS THROUGH MUCH OF THE DAY AND THEN FINALLY ERODING
BY TONIGHT. 0 TO 6 KM SHEAR OF AROUND 30 KT COULD SUPPORT THE NOTION
FOR MORE ORGANIZED CONVECTION ACROSS SE BARBER COUNTY. WILL HIGHLIGHT
THESE CONCERNS IN THE HWO. OTHER INFORMATION REGARDING CONVECTION CAN
BE FOUND IN THE SWODY1 PRODUCT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 328 AM CDT THU MAR 29 2012
A WEAK AREA OF HIGH PRESSURE WILL BUILD INTO WESTERN KANSAS EARLY
FRIDAY AS A COLD FRONT SINKS SOUTH INTO OKLAHOMA. THIS FRONT WILL
BECOME STATIONARY BY MID DAY AS AN UPPER LEVEL DISTURBANCE
EMBEDDED IN THE WEST NORTHWEST FLOW CROSSES INTO WESTERN KANSAS.
BOTH THE NAM AND GFS PLACES THE BETTER LATE DAY INSTABILITY
NEAR/JUST SOUTH OF THE OKLAHOMA BORDER WHICH IS ALSO WHERE THE
BETTER 850MB WARM AIR ADVECTION/ISENTROPIC LIFT IS FORECAST TO
IMPROVE AHEAD OF THIS UPPER WAVE. BASED ON THE LIFT,MOISTURE AND
INSTABILITY AT 00Z SATURDAY AHEAD OF AN UPPER LEVEL DISTURBANCE
WILL CONTINUE TO LEAN TOWARDS A DRY FORECAST FOR SOUTHWEST KANSAS.
DID HOWEVER KEEP THE 12 TO NEAR 15 PERCENT CHANCE OF PRECIPITATION
IN THE MEDICINE LODGE AND COLDWATER AREAS BASED ON HOW CLOSE THESE
LOCATIONS WILL BE TO THE MOISTURE/LIFT NORTH OF THE STATIONARY
FRONT EARLY FRIDAY NIGHT.
AS FOR TEMPERATURES...BASED ON 850MB TEMPERATURES AT 00Z SATURDAY
THE PREVIOUS FORECAST STILL LOOKS ON TRACK FOR HIGHS FRIDAY
AFTERNOON. DID HOWEVER LOWER TEMPERATURES IN SOUTHWEST KANSAS NEAR
THE OKLAHOMA BORDER BY A FEW DEGREES GIVEN THE BETTER CHANCES FOR
MORE CLOUD COVER IN THIS LOCATION FRIDAY AFTERNOON.
ONCE THIS SYSTEM MOVES EAST OF WESTERN KANSAS FRIDAY NIGHT A
WESTERLY DOWNSLOPE FLOW WILL THEN BEGIN TO DEVELOP. 24 HOUR 850MB
TEMPERATURE TRENDS OVER THE WEEKEND PERIOD SUPPORTS A NICE WARM
UP. 80S WILL BE LIKELY BOTH DAYS. A FEW LOCATIONS MAY EVEN
APPROACH 90 DEGREES ALONG AND SOUTH OF DODGE CITY IF THE 00Z
MONDAY 850MB TEMPERATURES FROM THE GFS AND ECMWF VERIFIES.
ON SUNDAY IT WILL ALSO BE WINDY AS A TIGHT SURFACE PRESSURE GRADIENT
DEVELOPS ACROSS WESTERN KANSAS IN RESPONSE TO AN AREA OF LOW
PRESSURE DEEPENING ALONG THE LEE OF THE ROCKIES. THIS DEEPENING
SURFACE LOW WILL THEN SLIDE EAST INTO WESTERN KANSAS SUNDAY NIGHT
AS AN UPPER LEVEL TROUGH EXITS THE ROCKIES AND MOVES OUT INTO THE
CENTRAL PLAINS. AN ELEVATED MIXED LAYER SHOULD INHIBIT
PRECIPITATION CHANCES ON SUNDAY AHEAD OF THIS NEXT SYSTEM. DRY AIR
MIXING DOWN TO THE SURFACE WILL INCREASE THE FIRE DANGER LEVELS
ACROSS WESTERN KANSAS...ESPECIALLY WEST OF THE DRY LINE.
A COLD FRONT WILL MOVE ACROSS WESTERN KANSAS EARLY MONDAY AS THIS
UPPER LEVEL TROUGH CROSSES INTO THE CENTRAL PLAINS. THE GFS
SUGGESTS SOME IMPROVING MID LEVEL INSTABILITY AS THE UPPER LEVEL
TROUGH CROSSES WESTERN KANSAS DURING THE DAY. BASED ON WHERE THE
BETTER MOISTURE RETURN WILL BE AHEAD OF THIS SYSTEM HAVE DECIDED
TO STAY CLOSE TO THE ALLBLEND ON PRECIPITATION CHANCES. THIS WOULD
PLACE A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS PORTIONS OF NORTH
CENTRAL KANSAS. AS FOR TEMPERATURES HAVE DECIDED TO FOLLOW THE
GENERAL 925-850MB TEMPERATURE TRENDS FROM THE GFS AND ECMWF. THIS
WOULD FAVOR HIGHS MAINLY IN THE 60S ON MONDAY AS THIS UPPER LEVEL
TROUGH PASSES.
A WARMING TREND WILL RETURN BY MID WEEK AS AN UPPER LEVEL RIDGE
CROSSES THE ROCKIES AND A WESTERLY DOWNSLOPE FLOW IMPROVES ACROSS
EASTERN COLORADO AND WESTERN KANSAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1230 AM CDT THU MAR 29 2012
MAIN CONCERN FOR THE 06Z TAFS WAS TO REDUCE CIGS, PARTICULARLY AT
KHYS IN ASSOCIATION WITH REDUCED VISIBILITIES FROM DENSE FOG. BUFKIT,
MOS, AND HRRR LOW LEVEL RH`S FIELDS SUGGEST FOG DEVELOPING THIS MORNING
AND BECOMING DENSE A FEW HOURS CENTERED AROUND SUNRISE. LIFR CIGS EXPECTED
FOR KHYS. HAVE LOWER CONFIDENCE FOR KDDC AND KGCK AND KEPT CIGS IN MVFR
CONDITIONS. DRY AIR ADVECTION WILL SPREAD ACROSS THE REGION BEHIND AND
IN ASSOCIATION WITH A TRAVERSING SFC LOW BY LATE MORNING. CIGS SHOULD
IMPROVE TO VFR BY THAT TIME.
&&
.FIRE WEATHER...
ISSUED AT 328 AM CDT THU MAR 29 2012
GUSTY SOUTHWEST WINDS WILL DEVELOP ON SUNDAY AS AN AREA OF LOW
PRESSURE DEEPENS ACROSS NORTHEAST COLORADO. SUSTAINED WINDS OF 20 TO
30 MPH WILL BE LIKELY. IN ADDITION AFTERNOON RELATIVE HUMIDITIES
ARE EXPECTED TO FALL BACK INTO THE TEENS WEST OF A DRYLINE WHICH
CURRENTLY IS EXPECTED TO EXTEND FROM NEAR SCOTT CITY TO GARDEN
CITY TO NEAR LIBERAL. THIS COMBINATION WILL RESULT IN VERY HIGH TO
CRITICAL FIRE WEATHER CONDITIONS ACROSS PORTIONS OF WESTERN KANSAS
SUNDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 83 48 78 51 / 10 10 10 10
GCK 82 47 77 51 / 0 10 10 10
EHA 81 46 76 51 / 0 10 10 10
LBL 85 47 77 49 / 0 10 10 10
HYS 79 47 79 50 / 0 10 10 10
P28 84 53 80 56 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR KSZ030-031-
043>046.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...SUGDEN
FIRE WEATHER...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
220 AM CDT THU MAR 29 2012
...UPDATE TO SYNOPSIS AND SHORT TERM DISCUSSIONS...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 217 AM CDT THU MAR 29 2012
.SYNOPSIS...
ISSUED AT 217 AM CDT THU MAR 29 2012
00Z 300 HPA SYNOPTIC MAP ANALYSIS SHOWS A 95 KT JET PUSHING ASHORE ACROSS
THE PACIFIC NORTHWEST IN ASSOCIATION WITH BROAD TROUGH EXTENDING FROM
THE PACNW TO THE NORTHERN ROCKIES. WEAKER 50 TO 75 KT BROAD W/NW FLOW
EXTENDED ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION.
THE 500 HPA FLOW PATTERN SHOWED THE TROUGH AXIS IN ASSOCIATION WITH
THE AFOREMENTIONED JET STREAK FROM THE NORTHEAST PACIFIC AND SE ACROSS
THE GREAT BASIN. LOWER IN THE ATMOSPHERE...NAMELY THROUGH THE 700 AND
850 HPA LAYERS, THE MOST INTERESTING ITEM WAS WARM AND DRY FLOW IN
THE LEE OF THE ROCKIES. AT THE SFC, MSAS SURFACE PRESSURE ANALYSIS SHOWED
A WEAK LOW PRESSURE CENTER ACROSS SE COLORADO. A WARM FRONT WAS EXTENDING
FROM THIS FEATURE ACROSS CENTRAL KANSAS. RICH MOISTURE AS MARKED BY
DEWPOINTS IN THE 60S DEG F EXTENDED ACROSS SOUTH CENTRAL KANSAS.
THIS MORNING:
THE MAIN ITEM OF CONCERN DURING THE MORNING PERIOD IS THE LIKELIHOOD
FOR DENSE FOG. HRRR AND MOS IS SUGGESTING THE GREATEST POTENTIAL FOR
DENSE FOG ACROSS WEST CENTRAL KANSAS THIS MORNING. THIS IS ALSO REFLECTED
IN 00Z NAM BUFKIT DATA. THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE
DEWPOINTS (LOW 50S DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A
WARM FRONT THAT WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
TODAY:
THE FOG SHOULD DISSIPATE/MIX OUT BY MID MORNING. THE REST OF THE SENSIBLE
WEATHER FOR TODAY WILL BE FAIRLY TRANQUIL. A BROAD UPPER LEVEL SHORTWAVE
TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS TODAY. SW KANSAS WILL BE
ON THE SOUTHEASTERN FRIDGES OF THE 400 HPA PV ANOMALY TODAY. AS A RESULT
OF THE AFOREMENTIONED UPPER LEVEL DYNAMICS SLIDING EAST THROUGH THE
DAY, THE RESULTANT SURFACE LOW WILL CONTINUE TO SLIDE TO THE EAST ACROSS
NORTHERN KANSAS AS WELL. A BIT OF DOWNSLOPE AND MIXING ACROSS THE SOUTHWESTERN
COUNTIES THIS AFTERNOON WILL PROVIDE VERY WARM TEMPERATURES NEAR THE
OKLAHOMA BORDER. EXPECT MID 80S DEG F IN THIS AREA. FURTHER NORTH, ONLY
LOOKING FOR UPPER 70S DEG F TO AROUND 80 DEG F AS A WEAK COLD FRONT
MOVES THROUGH EARLIER IN THE DAY. THE DRYLINE WITH UPPER 50S TO LOWER
60S DEG F DEWPOINTS WILL MIX EAST TODAY. THIS DRYLINE SHOULD BE LOCATED
ACROSS SOUTH CENTRAL KANSAS BY THIS AFTERNOON.
TONIGHT:
EVENTUALLY THE PACIFIC FRONT FOLLOWING BEHIND THE DRYLINE WILL CATCH
UP CLOSER TO THE DRYLINE. HAVE DISCOUNTED THE 00Z GFS SOLUTION AS THIS
MODEL SEEMS TO BE SUFFERING FROM BOUNDARY LAYER MOISTURE PROBLEMS AND
THE RESULTANT QPF LOOKS A LITTLE OVERZEALOUS. MAINLY STUCK WITH THE
00Z NAM AND 00Z WRF-NMM FOR POPS THIS EVENING. CONFINED POPS MAINLY ACROSS
SOUTH CENTRAL KANSAS AS TEMPERATURES IN THE 80S DEG F COMBINED WITH
NEAR 60 DEG F DEWPOINTS WILL CREATE ENOUGH SBCAPE IN THE 2000-2500 J/KG
RANGE SOUTH CENTRAL KANSAS. FORECAST SOUNDINGS SHOW CONSIDERABLE CINH
REMAINING ACROSS SC KS THROUGH MUCH OF THE DAY AND THEN FINALLY ERODING
BY TONIGHT. 0 TO 6 KM SHEAR OF AROUND 30 KT COULD SUPPORT THE NOTION
FOR MORE ORGANIZED CONVECTION ACROSS SE BARBER COUNTY. WILL HIGHLIGHT
THESE CONCERNS IN THE HWO. OTHER INFORMATION REGARDING CONVECTION CAN
BE FOUND IN THE SWODY1 PRODUCT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 PM CDT WED MAR 28 2012
MEDIUM RANGE MODELS INDICATE A SMALL AMPLITUDE UPPER LEVEL SHORTWAVE
TROUGH TRANSITIONING EAST ACROSS THE NORTHERN AND CENTRAL PLAINS
THURSDAY NIGHT BRINGING THE POSSIBILITY FOR SHOWERS AND THUNDERSTORMS
TO CENTRAL AND PORTIONS OF WESTERN KANSAS THURSDAY EVENING. AN
ATTENDANT COLD FRONT IS PROJECTED TO PUSH INTO WESTERN KANSAS
EARLIER THURSDAY WITH AMPLE LOW LEVEL MOISTURE POOLING AHEAD OF
THE BOUNDARY WITH H85 DEWPOINTS UP NEAR 10C. NAM AND GFS MODEL
SOUNDINGS SHOW PLENTY OF INSTABILITY AHEAD OF A DEVELOPING DRYLINE
WITH CAPE VALUES IN EXCESS OF 1500J/KG. HOWEVER, ONE ISSUE OF
CONCERN HAS ALL MODELS POINTING TO A FAIRLY WEAK WESTERLY FLOW ALOFT
ACROSS THE CENTRAL PLAINS WHICH MAY LIMIT THE STRENGTH CAPABILITY OF
ANY STORM DEVELOPMENT. STILL, WITH SOME UNCERTAINTY REMAINING AS TO
THE TIMING AND POSITIONING OF THE FRONTAL BOUNDARY, THE BEST CHANCE
FOR SHOWERS AND THUNDERSTORMS LOOKS TO BE ACROSS SOUTH CENTRAL
KANSAS THURSDAY EVENING. UPPER LEVEL RIDGING IS THEN EXPECTED TO
BUILD AS IT MOVES EAST ACROSS THE INTERMOUNTAIN WEST INTO THE
CENTRAL PLAINS THROUGH THE WEEKEND BRINGING ABOUT DRIER CONDITIONS
TO WESTERN KANSAS THROUGH AT LEAST EARLY SUNDAY. THE GFS AND ECMWF
INDICATE AN UPPER LEVEL TROUGH PUSHING ACROSS THE INTERMOUNTAIN
WEST LATE IN THE WEEKEND BRINGING THE NEXT REASONABLE CHANCE FOR
PRECIP TO WESTERN KANSAS EARLY NEXT WEEK.
TEMPERATURES ARE EXPECTED TO BE JUST ABOVE NORMAL FRIDAY EVEN IN
WAKE OF A COLD FRONTAL PASSAGE LATE THURSDAY. THE NAM, GFS, AND
ECMWF SHOW ONLY MARGINALLY COOLER AIR FILTERING INTO WESTERN KANSAS
WITH H85 TEMPERATURES MAINLY IN THE MID TO UPPER TEENS(C). LOOK FOR
HIGHS UP INTO THE 70S(F) FRIDAY AFTERNOON. A GRADUAL WARMING TREND
IS LIKELY THROUGH THE WEEKEND AS UPPER LEVEL RIDGING MOVES IN FROM
THE INTERMOUNTAIN WEST. EXPECT HIGHS UP INTO THE 80S(F) SATURDAY AND
SUNDAY AS A STRENGTHENING LEE SIDE TROUGH OF LOW PRESSURE ENHANCES
WARM AIR ADVECTION INTO WESTERN KANSAS WITHIN A STRONG SOUTHERLY LOW
LEVEL FLOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1230 AM CDT THU MAR 29 2012
MAIN CONCERN FOR THE 06Z TAFS WAS TO REDUCE CIGS, PARTICULARLY AT
KHYS IN ASSOCIATION WITH REDUCED VISIBILITIES FROM DENSE FOG. BUFKIT,
MOS, AND HRRR LOW LEVEL RH`S FIELDS SUGGEST FOG DEVELOPING THIS MORNING
AND BECOMING DENSE A FEW HOURS CENTERED AROUND SUNRISE. LIFR CIGS EXPECTED
FOR KHYS. HAVE LOWER CONFIDENCE FOR KDDC AND KGCK AND KEPT CIGS IN MVFR
CONDITIONS. DRY AIR ADVECTION WILL SPREAD ACROSS THE REGION BEHIND AND
IN ASSOCIATION WITH A TRAVERSING SFC LOW BY LATE MORNING. CIGS SHOULD
IMPROVE TO VFR BY THAT TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 83 48 78 51 / 10 10 10 10
GCK 82 47 77 51 / 0 10 10 10
EHA 81 46 76 51 / 0 10 10 10
LBL 85 47 77 49 / 0 10 10 10
HYS 79 47 79 50 / 0 10 10 10
P28 84 53 80 56 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY FROM 5 AM TO 10 AM CDT THIS MORNING FOR
KSZ030-031-043>046.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....JJOHNSON
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1230 AM CDT THU MAR 29 2012
...UPDATE FOR FOG AND 06Z TAF AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 1230 AM CDT THU MAR 29 2012
HAVE TWEAKED/CHANGED THE WX GRIDS WITHIN THE LAST HOUR TO ADD DENSE
FOG AND ISSUE THE DENSE FOG ADVISORY (NPW) PRODUCT. HRRR AND MOS
SUGGESTING THE GREATEST POTENTIAL FOR DENSE FOG ACROSS WEST CENTRAL
KANSAS THIS MORNING. THIS IS ALSO REFLECTED IN 00Z NAM BUFKIT DATA.
THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE DEWPOINTS (LOW 50S
DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A WARM FRONT THAT
WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 349 PM CDT WED MAR 28 2012
THE 12Z UPPER AIR ANALYSIS SHOWED A FLAT RIDGE OVER THE CENTRAL
UNITED STATES AHEAD OF A STRONG SHORTWAVE TROUGH THAT IS MOVING
ONSHORE OVER IN THE WEST. AT THE SURFACE...LOW PRESSURE OVER
NORTHWEST OKLAHOMA HAD SHIFTED NORTH TOWARD CENTRAL KANSAS INTO THE
VICINITY OF LARNED THIS AFTERNOON. A WEAK FRONTAL BOUNDARY HAS ALSO
SHIFTED NORTH WITH THE LOW AND EXTENDS INTO EASTERN KANSAS. A
STRONGER FRONTAL BOUNDARY WAS ALONG THE NEBRASKA/KANSAS BORDER. SOME
ELEVATED THUNDERSTORMS THAT DEVELOPED IN THAT AREA EARLIER TODAY
APPEAR TO BE LOCATED IN AN AREA OF MID LEVEL ASCENT ALONG THE 305K
ISENTROPIC SURFACE. AGREE WITH THE MODELS AND SPC DEPICTION OF THIS
CLUSTER OF STORMS DEVELOPING EAST AND SOUTHEAST ACROSS NORTH CENTRAL
AND NORTHEAST KANSAS AS THE UPGLIDE DEVELOPS INTO THAT AREA. THE NAM
IS ALSO SHOWING A SMALL AREA OF ASCENT DEVELOPING OVER SOUTH CENTRAL
KANSAS THIS EVENING. AM NOT OVERLY CONFIDENT WE WILL SEE ANYTHING
DEVELOP BUT WILL MAINTAIN SOME SMALL POPS GENERALLY EAST OF A LINE
FROM HAYS THROUGH KINSLEY AND MEDICINE LODGE DURING THE LATER
EVENING HOURS.
MOST OF THE ENERGY ASSOCIATED WITH THE SHORTWAVE TROUGH OVER THE
PACIFIC NORTHWEST LIFTS INTO SOUTHERN CANADA LATER TONIGHT AND
THURSDAY. THERE WILL BE SOME SHORTWAVE ENERGY MOVING EAST ACROSS THE
NORTHERN AND CENTRAL PLAINS ON THURSDAY. A SURFACE LOW PRESSURE
TROUGH WILL PUSH THROUGH WESTERN KANSAS DURING THE LATE MORNING AND
AFTERNOON HOURS. THE NAM AND GFS DIFFER ON WHETHER SHOWERS AND
THUNDERSTORMS WILL BREAK OUT ALONG THIS BOUNDARY WHICH MAKES SENSE
GIVEN THAT THE NAM MODEL SOUNDINGS ARE MORE CAPPED THROUGHOUT THE
DAY THAN THE GFS. WILL KEEP THE SLIGHT CHANCE POPS CURRENTLY IN THE
FORECAST GOING THROUGH THE AFTERNOON HOURS GENERALLY EAST OF HIGHWAY
283.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 PM CDT WED MAR 28 2012
MEDIUM RANGE MODELS INDICATE A SMALL AMPLITUDE UPPER LEVEL SHORTWAVE
TROUGH TRANSITIONING EAST ACROSS THE NORTHERN AND CENTRAL PLAINS
THURSDAY NIGHT BRINGING THE POSSIBILITY FOR SHOWERS AND THUNDERSTORMS
TO CENTRAL AND PORTIONS OF WESTERN KANSAS THURSDAY EVENING. AN
ATTENDANT COLD FRONT IS PROJECTED TO PUSH INTO WESTERN KANSAS
EARLIER THURSDAY WITH AMPLE LOW LEVEL MOISTURE POOLING AHEAD OF
THE BOUNDARY WITH H85 DEWPOINTS UP NEAR 10C. NAM AND GFS MODEL
SOUNDINGS SHOW PLENTY OF INSTABILITY AHEAD OF A DEVELOPING DRYLINE
WITH CAPE VALUES IN EXCESS OF 1500J/KG. HOWEVER, ONE ISSUE OF
CONCERN HAS ALL MODELS POINTING TO A FAIRLY WEAK WESTERLY FLOW ALOFT
ACROSS THE CENTRAL PLAINS WHICH MAY LIMIT THE STRENGTH CAPABILITY OF
ANY STORM DEVELOPMENT. STILL, WITH SOME UNCERTAINTY REMAINING AS TO
THE TIMING AND POSITIONING OF THE FRONTAL BOUNDARY, THE BEST CHANCE
FOR SHOWERS AND THUNDERSTORMS LOOKS TO BE ACROSS SOUTH CENTRAL
KANSAS THURSDAY EVENING. UPPER LEVEL RIDGING IS THEN EXPECTED TO
BUILD AS IT MOVES EAST ACROSS THE INTERMOUNTAIN WEST INTO THE
CENTRAL PLAINS THROUGH THE WEEKEND BRINGING ABOUT DRIER CONDITIONS
TO WESTERN KANSAS THROUGH AT LEAST EARLY SUNDAY. THE GFS AND ECMWF
INDICATE AN UPPER LEVEL TROUGH PUSHING ACROSS THE INTERMOUNTAIN
WEST LATE IN THE WEEKEND BRINGING THE NEXT REASONABLE CHANCE FOR
PRECIP TO WESTERN KANSAS EARLY NEXT WEEK.
TEMPERATURES ARE EXPECTED TO BE JUST ABOVE NORMAL FRIDAY EVEN IN
WAKE OF A COLD FRONTAL PASSAGE LATE THURSDAY. THE NAM, GFS, AND
ECMWF SHOW ONLY MARGINALLY COOLER AIR FILTERING INTO WESTERN KANSAS
WITH H85 TEMPERATURES MAINLY IN THE MID TO UPPER TEENS(C). LOOK FOR
HIGHS UP INTO THE 70S(F) FRIDAY AFTERNOON. A GRADUAL WARMING TREND
IS LIKELY THROUGH THE WEEKEND AS UPPER LEVEL RIDGING MOVES IN FROM
THE INTERMOUNTAIN WEST. EXPECT HIGHS UP INTO THE 80S(F) SATURDAY AND
SUNDAY AS A STRENGTHENING LEE SIDE TROUGH OF LOW PRESSURE ENHANCES
WARM AIR ADVECTION INTO WESTERN KANSAS WITHIN A STRONG SOUTHERLY LOW
LEVEL FLOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1230 AM CDT THU MAR 29 2012
MAIN CONCERN FOR THE 06Z TAFS WAS TO REDUCE CIGS, PARTICULARLY AT
KHYS IN ASSOCIATION WITH REDUCED VISIBILITIES FROM DENSE FOG. BUFKIT,
MOS, AND HRRR LOW LEVEL RH`S FIELDS SUGGEST FOG DEVELOPING THIS MORNING
AND BECOMING DENSE A FEW HOURS CENTERED AROUND SUNRISE. LIFR CIGS EXPECTED
FOR KHYS. HAVE LOWER CONFIDENCE FOR KDDC AND KGCK AND KEPT CIGS IN MVFR
CONDITIONS. DRY AIR ADVECTION WILL SPREAD ACROSS THE REGION BEHIND AND
IN ASSOCIATION WITH A TRAVERSING SFC LOW BY LATE MORNING. CIGS SHOULD
IMPROVE TO VFR BY THAT TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 50 79 51 83 / 10 10 10 0
GCK 47 79 50 83 / 10 10 10 0
EHA 46 79 48 83 / 10 10 10 0
LBL 48 80 49 83 / 10 10 10 0
HYS 49 79 51 83 / 10 10 10 0
P28 55 79 53 82 / 20 10 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY FROM 5 AM TO 10 AM CDT THIS MORNING FOR
KSZ030-031-043>046.
&&
$$
UPDATE...SUGDEN
SHORT TERM...GERARD
LONG TERM....JJOHNSON
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1205 AM CDT THU MAR 29 2012
...AVIATION UPDATE...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
UNCERTAIN THAT GROUND FOG WILL DEVELOP...BUT THERE IS STILL SOME
HINT OF IT FROM THE OBJECTIVE MOS GUIDANCE...SO WILL KEEP A TEMPO
FOR MVFR VSBY AROUND SUNRISE. OTHERWISE THINK SUBSIDENCE FROM THE
MCV WILL LIMIT ADDITIONAL CONVECTION OVERNIGHT. STORMS WILL BE
POSSIBLE AGAIN LATE THURSDAY AFTERNOON AS A COLD FRONT SWEEPS
THROUGH.
WOLTERS
&&
.PREV DISCUSSION... /636 PM CDT WED MAR 28 2012/
LATEST SFC ANALYSIS SUGGESTS THE WARM FRONT HAS BECOME A LITTLE MORE
DIFFUSE OVER THE LAST HOUR. THERE IS STILL PLENTY OF INSTABILITY FOR
STORM DEVELOPMENT BUT 0 TO 1 KM SHEAR REMAINS MARGINAL. HOWEVER AS
SEEN WITH RECENT STORMS...DEEP LAYER SHEAR IS GOOD ENOUGH FOR
SUPERCELL DEVELOPMENT. THE CONCERN IS WHEN THE LOW LEVEL JET
DEVELOPS THIS EVENING. LOW LEVEL SHEAR COULD INCREASE AND ANY STORM
ROOTED IN THE BOUNDARY LAYER MAY BE ABLE TO FEED OFF OF THE
INCREASED SHEAR. EXPECT SEVERE THUNDERSTORM HAZARDS OF HAIL AND
POTENTIAL AN ISOLATED TORNADO TO PERSIST WELL INTO THE EVENING.
WOLTERS
/324 PM CDT WED MAR 28 2012/
ZONAL MID AND UPPER LEVEL FLOW WAS NOTED ACROSS THE CENTRAL AND
SOUTHERN PLAINS. A MINOR H5 TROUGH WAS MOVING INTO NORTHWEST KS THIS
AFTERNOON.
AT 19Z...A WEAK SFC LOW WAS LOCATED NORTHEAST OF DDC. A WARM FRONT
FRONT EXTEND EAST-NORTHEAST FROM THE SFC LOW ACROSS CENTRAL AND
NORTHEAST KS. THE SFC WARM FRONT WAS LOCATED ABOUT 20 MILES NORTH OF
I-70. SOUTH OF THE SFC WARM FRONT DEWPOINTS WERE IN THE LOWER 60S
AND SBCAPE WAS IN THE 2,000 TO 2,500 J/KG RANGE. AS TEMPERATURES
WARM LATER THIS AFTERNOON...SBCAPE WILL INCREASE TO 3,000 TO 3,500
J/KG ACROSS THE SOUTHERN HALF OF THE CWA.
ELEVATED THUNDERSTORMS HAVE DEVELOPED NORTH OF THE WARM FRONT ACROSS
SOUTH CENTRAL NE THIS AFTERNOON. THIS AREA OF STORMS WILL EXPAND
EAST AND SOUTHEAST ACROSS NORTH CENTRAL KS LATE THIS AFTERNOON. ONCE
THE STORMS REACH THE WARM SECTOR THE NEW UPDRAFTS WILL BECOME
ROOTED IN THE BOUNDARY LAYER. 0-6KM BULK SHEAR WILL BE ABOUT 40 TO
50 KTS LATE THIS AFTERNOON AND THROUGH THE EVENING HOURS ACROSS THE
CWA. GIVEN THE MODERATE VERTICAL WIND SHEAR AND
INSTABILITY...THUNDERSTORM UPDRAFTS THAT DEVELOP ALONG AND SOUTH OF
THE WARM FRONT WILL ROTATE. THE SUPERCELL THUNDERSTORMS WILL BE
CAPABLE OF PRODUCING LARGE HAIL...MAY BE UP TO BASEBALL SIZE...AND
DAMAGING OUTFLOW WINDS. THE LOW-LEVEL VERTICAL WIND SHEAR IS
WEAKER...THUS TORNADO PROBABILITIES WILL BE LOW. HOWEVER...LATE THIS
AFTERNOON AND EARLY THIS EVENING ACROSS NORTH CENTRAL KS BRIEF
TORNADOES MAY BE POSSIBLE WITH ANY ISOLATED SUPERCELLS. ALSO, IF
SUPERCELLS ARE ISOLATED ACROSS EAST CENTRAL KS THE RUC AND NAM
MODELS SHOW THE BACKED LOW-LEVEL JET INCREASING TO 30 TO 40
KTS...WHICH WOULD PROVIDE A BETTER ENVIRONMENT FOR ANY ISOLATED
SUPERCELL TO PRODUCE TORNADOES FROM 1Z TO 4Z.
AS THE EVENING PROGRESSES THE ISOLATED TO SCATTERED SUPERCELL
THUNDERSTORMS MAY CONGEAL INTO SEGMENTED SQUALL LINES OR QLCS`S.
INDIVIDUAL UPDRAFTS MAY BE STRONG ENOUGH FOR LARGE HAIL...AND THE
THREAT FOR DAMAGING WINDS MAY INCREASE WITH THE DEVELOPMENT OF A
QLCS THROUGH THE EVENING HOURS ACROSS THE REMAINDER OF THE CWA. THE
BEST CHANCES FOR THUNDERSTORMS THIS EVENING WILL BE ALONG AND NORTH
OF THE WARM FRONT...WHICH WILL BE ABOUT I-70 NORTH TO THE NE BORDER.
THOUGH STORMS WILL DEVELOP SOUTHEAST ACROSS THE REMAINDER OF THE CWA
DURING THE LATE EVENING HOURS. THE THREAT FOR SEVERE WEATHER SHOULD
DECREASE AFTER MIDNIGHT AS THE INSTABILITY DECREASES. IF A QLCS
DEVELOPS THAN HEAVY RAINFALL MAY BE POSSIBLE LATER THIS EVENING
ACROSS NORTHEAST AND EAST CENTRAL KS.
THURSDAY...A MORE AMPLIFIED H5 TROUGH WILL MOVE ACROSS THE CENTRAL
PLAINS DURING THE AFTERNOON HOURS. A SFC COLD FRONT WILL PUSH
SOUTHEAST ACROSS NORTH CENTRAL KS BY AFTERNOON. SCATTERED
THUNDERSTORMS WILL ONCE AGAIN DEVELOP ALONG AND AHEAD OF THE COLD
FRONT. THE 12Z NAM MODEL FORECAST SBCAPE TO INCREASE TO AROUND 3,000
J/KG ACROSS THE WARM SECTOR. THUNDERSTORMS THAT DEVELOP MAY BECOME
SEVERE. THE 0-6KM BULK SHEAR WILL BE A BIT STRONGER AHEAD OF THE H5
TROUGH BUT THE LOW-LEVEL WINDS AHEAD OF THE COLD FRONT WILL VEER
THROUGH THE AFTERNOON. THEREFORE...THE PRIMARY HAZARD WITH ANY
SUPERCELL THUNDERSTORM OR SQUALL LINE WILL BE LARGE HAIL AND
DAMAGING OUTFLOW WINDS. SKIES WILL CLEAR BY MID MORNING INTO THE
EARLY AFTERNOON HOURS. THUS THE INSOLATION AND SOUTHERLY WINDS AHEAD
OF THE COLD FRONT WILL HELP HIGH TEMPERATURES TO REACH THE UPPER 70S
TO LOWER 80S ACROSS THE CWA. IF THE SFC FRONT MOVES A BIT FASTER
THEN NORTH CENTRAL KS MAY BE A FEW DEGREES COOLER.
GARGAN
CONVECTION TIED TO COLD FRONT EXPECTED TO MOVE OUT OF EASTERN
KANSAS THURSDAY NIGHT...WITH CLEARING SKIES FOR FRIDAY. MUCH ABOVE
NORMAL TEMPERATURES SHOULD CONTINUE THROUGH THE WEEKEND.
NEXT CHANCE FOR PRECIPITATION WILL OCCUR WITH A STRONGER COLD
FRONT COMING THROUGH SUNDAY NIGHT AS DEEP UPPER TROUGH MOVES
ACROSS THE PLAINS. SOME WRAPAROUND SHOWERS LOOK LIKE THEY WILL
LINGER INTO MONDAY ASSOCIATED WITH THE COLD AIR ALOFT BEHIND THE
FRONT.
TEMPERATURES TUESDAY MORNING COULD FALL INTO THE 30S BEHIND THAT
SYSTEM...BUT WITH EXPECTED MIXING CONTINUING OVERNIGHT...WOULD
NOT THINK THAT FROST WOULD BE LIKELY.
DRY CONDITIONS AND A GRADUAL WARMUP IS THEN IN STORE FOR THE
MIDDLE OF THE WEEK.
60
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1155 PM CDT WED MAR 28 2012
.UPDATE...
REST OF TONIGHT:
ONE FINAL UPDATE HAS BEEN ISSUED TO CANCEL SVR #114 FROM GREENWOOD...
WOODSON & ALLEN COUNTIES AS TSRA QUICKLY DISSIPATED IN RESPONSE TO
EQUALLY RAPID AIRMASS STABILIZATION. ALL POPS/WX/QPF GRIDS HAVE
LIKEWISE BEEN UPDATED TO REFLECT THESE MOST RECENT TRENDS. THERE STILL
REMAINS SOME CONCERN FOR LIGHT FOG DEVELOPMENT 4-5AM WITH 2SM BR VSBYS
POSSIBLE. ANY FOG THAT DOES DEVELOP WOULD DISSIPATE BY 9AM CDT.
&&
.PREV DISCUSSION... /ISSUED 1010 PM CDT WED MAR 28 2012/
MESOSCALE/CONVECTIVE UPDATE...
NEARLY STATIONARY SVR TSRA CELL ~30NM IN DIAMETER REMAINS CAMPED OVER
NE 1/3 OF GREENWOOD COUNTY WHERE TENNISBALL-SIZED HAIL & FLASH FLOOD-
PRODUCING TORRENTIAL RAINS WILL CONTINUE TO PLAGUE THE COUNTY THROUGH
MID-NIGHT & LIKELY BEYOND. STILL ANTICIPATE SOME ESE PROPAGATION AS
LOW-LVL JET CONTINUES TO STRENGTHEN FROM CNTRL OK N/NE ACROSS SE KS.
SHARPENED POPS/WX/QPF GRIDS THROUGH MID-NIGHT TO FURTHER REFINE MOST
RECENT CONVECTIVE TRENDS...NO DOUBT FOCUSING GREENWOOD & WOODSON
COUNTIES. FURTHER REFINEMENT IS LIKELY FROM MID- NGT THROUGH 7 AM CDT.
STAY TUNED.
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
IMMEDIATE FOCUS (NO PUN INTENDED) IS ON WHAT HAS BECOME AN ISOLD SVR
TSRA (CAPABLE OF VERY LARGE HAIL & ++RA) OCCURRING OVER NRN GREENWOOD
COUNTY. FOR NOW CELL REMAINS NEARLY STATIONARY BUT CONTINUED CONCERN
THAT CELL COULD SLOWLY PROPAGATE E/SE TOWARD KCNU EARLY THU MORNING.
FOR NOW PLAN IS TO KEEP "VCTS" ASSIGNED TO KCNU & BE QUICK TO UPDATE
THE MOMENT DOPPLER TRENDS INDICATE E/SE EXPANSION TO BE FURTHER THAN
PICTURED AT THIS TIME.
SECOND FOCUS IS ON POTENTIAL FOR 1,000-1,500FT CIGS & 4-5SM VSBYS LATE
TONIGHT/EARLY THU MORNING AS WEAK LWR-DECK TROF AXIS REMAINS SITUATED
OVER WRN KS. RADIATIONAL COOLING COUPLED WITH CONTINUED NWD SURGING
GULF MOISTURE SHOULD KEEP ALL 5 TERMINALS IN MVFR STATUS 10Z-14Z WITH
ALL 5 TERMINALS RETURNING TO VFR STATUS BY 15Z.
PREV DISCUSSION... /ISSUED 834 PM CDT WED MAR 28 2012/
MESOSCALE/CONVECTIVE UPDATE...
CLUSTER OF SVR TSRA CONTINUES TO BUILD/PROPAGATE SLOWLY E/SE FROM
GREENWOOD TOWARD WOODSON & ALLEN COUNTIES ALONG FAIRLY WELL-DEFINED
SFC-850MB MOISTURE AXIS ORIENTED ALONG WEAK ELEVATED FRONTAL BOUNDARY.
AS SUCH SVR #114 HAS BEEN ISSUED FOR ALL 3 COUNTIES TIL MID-NIGHT. THE
VERY SLOW MOVEMENT OF THE CELLS NO DOUBT PRODUCES AN INCREASED THREAT
FOR LOCALIZED FLOODING FROM NRN GREENWOOD TO NRN WOODSON COUNTIES. ALL
WX/POPS/QPF HAVE BEEN FINE-TUNED.
PREV DISCUSSION... /ISSUED 308 PM CDT WED MAR 28 2012/
DISCUSSION...
THE PRIMARY FOCUS CONTINUES TO BE PERIODIC THUNDERSTORM CHANCES
THROUGH THE WEEK.
A BROAD MID/UPPER RIDGE WAS COVERING MUCH OF THE CENTRAL AND SOUTHERN
CONUS WHILE A SUBTLE SHORTWAVE TROUGH WAS MOVING OVER SOUTHERN
KANSAS EARLY THIS AFTERNOON. THE WARM FRONT HAS BECOME DIFFUSE
MOST EVIDENT IN THE TD SPREADS LOCATED NEAR I-70 EARLY THIS
AFTERNOON. STRONG CINH IS EXPECTED TO PRECLUDE MORE WIDESPREAD
THUNDERSTORM DEVELOPMENT FURTHER SOUTH ALONG THE DRY LINE THIS
AFTERNOON/EARLY EVENING BUT MAINTAINED HIGHER POPS ALONG AND NORTH
OF THE DIFFUSE WARM FRONT BORDERING TOP CWA THIS EVENING/TONIGHT AS
STRONGER 305K ISENTROPIC UPGLIDE BECOMES JUXTAPOSED ALONG THE NOSE
OF THE LLJ. THE LATEST HRRR KEEPS THE MAIN AREA OF CONVECTION WELL
NORTH OF THE FORECAST AREA...BUT MAINTAINED MID POPS ACROSS MUCH OF
CENTRAL KANSAS WHERE THE ACTIVITY MAY DEVELOP BEFORE SHIFTING
EASTWARD OUT OF THE AREA AFTER 09-11Z OR EARLIER. ANY STORMS THAT
DEVELOP THROUGH TONIGHT MAY BECOME SEVERE WITH LARGE HAIL AND
DAMAGING WINDS.
THU-SUN...ABOVE NORMAL TEMPERATURES ARE ANTICIPATED THROUGH THE
PERIOD WITH ANOTHER OPPORTUNITY FOR DEEP MOIST CONVECTION LATE
THURSDAY AFTERNOON/THURSDAY NIGHT AS A SHORT WAVE TROUGH TRANSLATES
RAPIDLY EAST OVER THE AREA. THE NAM IS MUCH MORE PROGRESSIVE WITH
THE SFC TROUGH AXIS AND TRENDED POPS FURTHER EAST COMPARED TO THE
PREVIOUS FORECAST KEEPING THE HIGHEST PROBABILITIES ALONG/EAST OF
THE KANSAS TURNPIKE. SHORTWAVE RIDGING IS PROGGED TO RETURN TO THE
CENTRAL PLAINS FRI-SAT LEADING TO FAIR WEATHER AND CONTINUED ABOVE
NORMAL TEMPERATURES. TRENDED HIGHS ON FRI-SUN SLIGHTLY HIGHER WITH
READINGS CLIMBING INTO THE LOW-MID 80S SAT-SUN.
MON-WED...ANOTHER MORE ROBUST MID/UPPER TROUGH WILL RACE EASTWARD
ACROSS THE CENTRAL PLAINS LATE SUNDAY INTO MONDAY BRINGING A RETURN
TO SEASONABLE TEMPERATURES IN THE 60S INTO THE BEGINNING OF NEXT
WEEK. PRECIPITATION CHANCES CONTINUE TO LOOK SLIM GIVIN THE
PROGRESSIVE NATURE OF THE MID/UPPER TROUGH WITH A RETURN TO ABOVE
NORMAL TEMPERATURES TOWARD THE MIDDLE OF THE WEEK.
FIRE WEATHER...
A TROUGH OF LOW PRESSURE WILL DEVELOP ACROSS CENTRAL KANSAS ON
THURSDAY WITH WIDELY SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE
ALONG AND EAST OF THIS TROUGH. FURTHER WEST...LOW RELATIVE
HUMIDITIES MAY COMBINE WITH GUSTY SOUTHWEST WINDS CREATING NEAR
CRITICAL FIRE WEATHER CONDITIONS AT TIMES DURING THE AFTERNOON HOURS
ON THURSDAY. GUSTY SOUTHWEST WINDS WILL RETURN LATE IN THE WEEKEND
AHEAD OF A STRONG STORM SYSTEM MOVING OVER THE ROCKIES. GUSTY NORTHWEST
WINDS WILL FOLLOW THE PASSAGE OF A COLD FRONT LATE SUNDAY
NIGHT/EARLY MONDAY WITH A RETURN TO MORE SEASONABLE TEMPERATURES FOR
THE BEGINNING OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 61 85 56 79 / 20 30 20 10
HUTCHINSON 60 83 54 78 / 10 20 20 10
NEWTON 60 82 57 78 / 30 20 20 10
ELDORADO 61 84 59 79 / 30 30 30 10
WINFIELD-KWLD 62 85 58 81 / 20 20 40 10
RUSSELL 55 80 49 79 / 20 20 20 10
GREAT BEND 58 81 51 78 / 10 20 20 10
SALINA 59 83 54 80 / 40 20 20 10
MCPHERSON 61 82 54 79 / 20 20 20 10
COFFEYVILLE 63 85 59 81 / 30 20 60 20
CHANUTE 61 84 59 81 / 70 20 60 10
IOLA 61 83 59 81 / 70 20 60 10
PARSONS-KPPF 62 85 59 80 / 40 20 60 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
406 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD TODAY AND PROVIDE DRY...BUT COOLER
WEATHER. RAIN CHANCES ARE SET TO INCREASE ON FRIDAY AS LOW
PRESSURE CROSSES THE REGION. WEEKEND WEATHER WILL FEATURE
ONLY LOW PRECIPITATION CHANCES AND MODERATING TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
STRATOCUMULUS BLANKET WILL CONTINUE TO SLIDE SOUTHWARD ACROSS THE
UPPER OHIO REGION AS COLD ADVECTION IS UNDERWAY FOLLOWING PASSAGE
OF YESTERDAYS FRONT. PRECIP PROBABILITIES FOR THIS MORNING WERE
REDUCED GIVEN MODEL AGREEMENT ON LOW INVERSION LEVELS AND DRYING
ALOFT. SLIGHT NUMBERS WERE RETAINED FOR AREAS NORTH AND EAST OF
PITTSBURGH THROUGH THE PREDAWN HOURS.
STRATOCU WILL ERODE BY THE EVENING AS SURFACE RIDGE AXIS SLIDES
OVER THE AREA. WITH DIMINISHED WIND AND CLOUD COVER...RADIATIONAL
COOLING WILL RAPIDLY COMMENCE WITH TEMPERATURES FALLING INTO THE
30S ACROSS THE ENTIRE AREA BY FRIDAY MORNING...AND UPPER 20S ARE
PROJECTED OVER THE RIDGE ZONES AND OVER COUNTIES NORTH OF PITTSBURGH.
WARM...MOIST ADVECTION/MID LEVEL CLOUDINESS IN ADVANCE OF MIDWRN
LOW PRESSURE ARE CURRENTLY PROJECTED TO ARRIVE AT AROUND
DAYBREAK...TOO LATE TO PRECLUDE AREAS OF FROST FOR ALL ZONES.
FREEZE WARNING WAS ISSUED FOR THE NORTHEASTERN HALF OF THE COUNTY
WARNING AREA...WHERE SURFACE RIDGE AXIS WILL CROSS AND WHERE
DRIER AIR WILL SETTLE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AFOREMENTIONED MIDWRN LOW PRES LOOKS TO APPROACH THE AREA ON
FRIDAY...WITH PASSAGE PROJECTED FOR FRIDAY NIGHT...AND SYSTEM EXIT
ON SATURDAY. HAVE GENERALLY PERSISTED WITH PREVIOUS
FORECAST...BUT WITH ADJUSTMENTS TO TIMING AS PER LATEST
DETERMINISTIC MODEL TRENDS. HAVE ALSO INCLUDED A THUNDER MENTION
FOR THE SOUTHERN ZONES ON FRIDAY AFTERNOON GIVEN THE INSTABILITY
PROGNOSIS AND LOW PRESSURE TRACK.
BY SUNDAY...TEMPERATURE MODERATION IS FORECAST TO BE UNDERWAY AS
GREAT LAKES RIDGE AMPLIFIES...BUT SHORTWAVE IN NORTHWEST FLOW MAY
SPAWN SOME SHOWERS GIVEN LATEST MODEL SOLUTIONS. HAVE DECIDED TO
ENTER A SLIGHT CHANCE FOR NOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE NEXT LOW WILL TRACK FROM THE UPPER MS VALLEY INTO SOUTHERN
ONTARIO AND WILL PUSH A COLD FRONT THROUGH THE OHIO VALLEY
TUESDAY. SCATTERED SHOWERS SHOULD ACCOMPANY THIS SYSTEM TUESDAY
INTO EARLY WEDNESDAY.
TEMPERATURES ARE FORECAST TO RANGE BETWEEN 10 AND 15 DEGREES ABOVE
NORMAL THROUGH TUESDAY...WITH A RETURN TO NEAR NORMAL READINGS BY
WEDNESDAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
RECENT SURFACE AND SATELLITE DATA, COUPLED WITH HRRR AND NAM MODEL
OUTPUT, SHOW COLD POOL MVFR STRATOCUMULUS EXPANDING SOUTHWARD ACROSS
THE UPPER OHIO VALLEY THROUGH 12Z. DAYTIME HEATING WILL INDUCE
VERTICAL MIXING TO CAUSE CLOUD CEILINGS TO LIFT THIS MORNING AND
THEN DISSIPATE, SOUTH TO NORTH, THIS AFTERNOON. EXPECT VFR WITH
MOSTLY CLEAR SKIES TONIGHT.
SURFACE WINDS WILL BE NORTHWEST 10-15 KTS TODAY AND BECOME LIGHT
TONIGHT.
OUTLOOK...FRIDAY THROUGH MONDAY...
RESTRICTIONS ARE POSSIBLE FRIDAY AFTERNOON INTO SATURDAY DUE TO
SHOWERS AND LOW CLOUDS ASSOCIATED WITH PASSING EASTBOUND LOW
PRESSURE SYSTEM. EXPECT MAINLY VFR SUNDAY AND MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR MDZ001.
OH...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR OHZ041.
PA...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR PAZ007>009-
013>016-020>023-029-073>076.
WV...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR WVZ023-041.
&&
$$
15/11
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
137 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD TODAY AND PROVIDE DRY...BUT COOLER
WEATHER. RAIN CHANCES ARE SET TO INCREASE ON FRIDAY AS LOW
PRESSURE CROSSES THE REGION. WEEKEND WEATHER WILL FEATURE
IMPROVING CONDITIONS AND MODERATING TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
STRATOCUMULUS BLANKET WILL CONTINUE TO SLIDE SOUTHWARD ACROSS THE
UPPER OHIO REGION AS COLD ADVECTION IS UNDERWAY FOLLOWING PASSAGE
OF YESTERDAYS FRONT. PRECIP PROBABILITIES FOR THIS MORNING WERE
REDUCED GIVEN MODEL AGREEMENT ON LOW INVERSION LEVELS AND DRYING
ALOFT. SLIGHT NUMBERS WERE RETAINED FOR AREAS NORTH AND EAST OF
PITTSBURGH THROUGH THE PREDAWN HOURS.
STRATOCU WILL ERODE BY THE EVENING AS SURFACE RIDGE AXIS SLIDES
OVER THE AREA. WITH DIMINISHED WIND AND CLOUD COVER...RADIATIONAL
COOLING WILL RAPIDLY COMMENCE WITH TEMPERATURES FALLING INTO THE
30S ACROSS THE ENTIRE AREA BY FRIDAY MORNING...AND UPPER 20S ARE
PROJECTED OVER THE RIDGE ZONES AND OVER COUNTIES NORTH OF PITTSBURGH.
WARM...MOIST ADVECTION/MID LEVEL CLOUDINESS IN ADVANCE OF MIDWRN
LOW PRESSURE ARE CURRENTLY PROJECTED TO ARRIVE AT AROUND
DAYBREAK...TOO LATE TO PRECLUDE AREAS OF FROST FOR ALL ZONES. SUB
30 COUNTIES ARE BEING EVALUATED FOR HEADLINES.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AFOREMENTIONED MIDWRN LOW PRES LOOKS TO APPROACH THE AREA ON
FRIDAY...WITH PASSAGE PROJECTED FOR FRIDAY NIGHT...AND SYSTEM EXIT
ON SATURDAY. HAVE GENERALLY PERSISTED WITH PREVIOUS
FORECAST...BUT WITH ADJUSTMENTS TO TIMING AS PER LATEST
DETERMINISTIC MODEL TRENDS. HAVE ALSO INCLUDED A THUNDER MENTION
FOR THE SOUTHERN ZONES ON FRIDAY AFTERNOON GIVEN THE INSTABILITY
PROGNOSIS.
BY SUNDAY...TEMPERATURE MODERATION IS FORECAST TO BE UNDERWAY AS
GREAT LAKES RIDGE AMPLIFIES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE NEXT LOW WILL TRACK FROM THE UPPER MS VALLEY INTO SOUTHERN
ONTARIO AND WILL PUSH A COLD FRONT THROUGH THE OHIO VALLEY
TUESDAY. SCATTERED SHOWERS SHOULD ACCOMPANY THIS SYSTEM TUESDAY
INTO EARLY WEDNESDAY.
TEMPERATURES ARE FORECAST TO RANGE BETWEEN 10 AND 15 DEGREES ABOVE
NORMAL THROUGH TUESDAY...WITH A RETURN TO NEAR NORMAL READINGS BY
WEDNESDAY.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
RECENT SURFACE AND SATELLITE DATA, COUPLED WITH HRRR AND NAM MODEL
OUTPUT, SHOW COLD POOL MVFR STRATOCUMULUS EXPANDING SOUTHWARD ACROSS
THE UPPER OHIO VALLEY THROUGH 12Z, BEFORE STOPPING NEAR THE I-70
CORRIDOR. DAYTIME HEATING WILL INDUCE VERTICAL MIXING TO CAUSE CLOUD
CEILINGS TO LIFT THIS MORNING AND THEN DISSIPATE, SOUTH TO NORTH,
THIS AFTERNOON. EXPECT VFR WITH MOSTLY CLEAR SKIES TONIGHT.
SURFACE WINDS WILL BE NORTHWEST 10-15 KTS TODAY AND BECOME LIGHT
TONIGHT.
OUTLOOK...FRIDAY THROUGH MONDAY...
RESTRICTIONS ARE POSSIBLE FRIDAY AFTERNOON INTO SATURDAY DUE TO
SHOWERS AND LOW CLOUDS ASSOCIATED WITH PASSING EASTBOUND LOW
PRESSURE SYSTEM. EXPECT MAINLY VFR SUNDAY AND MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/11
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1258 AM EDT THU MAR 29 2012
.UPDATE...
ISSUED AT 1214 AM EDT THU MAR 29 2012
RAISED LOW TEMPERATURES A BIT AS CLOUD COVER LOOKS TO BE STUBBORN
AND SLOW TO LEAVE. ALSO KEPT CLOUDS IN FOR THE REST OF TONIGHT
ALMOST EVERYWHERE EXCEPT THE FAR WEST AND SOUTH AS DRIER AIR WORKS
IN.
&&
.SYNOPSIS...
ISSUED AT 355 PM EDT WED MAR 28 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE UPR GRT LKS DOWNSTREAM OF UPR RIDGE IN THE PLAINS. SHRTWV/SFC LO
THAT IMPACTED THE AREA YDAY IS NOW MOVING E THRU QUEBEC...BUT CYC
SFC-H85 NW FLOW OF MOIST AIR REMAINS IN PLACE OVER THE UPR GRT LKS.
A SHRTWV OVER MN IS MOVING SEWD...AND IN CONCERT WITH SOME DEEPER
MSTR SHOWN ON THE 12Z INL RAOB HAS CAUSED SOME SCT -SHRA THAT ARE
MIXING WITH SN AS COLDER AIR ARRIVES FM THE NW...WHERE THE 12Z H85
TEMP WAS AS LO AS -9C AT YPL. BUT UPSTREAM RAOBS SHOW MID LVL DRYING
IN THE WAKE OF THE SHRTWV IS SPREADING SEWD TOWARD THE UPR GRT LKS.
DESPITE THE HIER LVL DRYING...MUCH LO CLD LINGERS IN THE LLVL CYC
FLOW OF THE MOISTER LLVLS DEPICTED ON THE 12Z INL/YPL RAOBS. SOME
CLEARING IS SHOWING UP OVER MANITOBA CLOSER TO DRIER LLVL AIR SHOWN
ON THE 12Z THE PAS RAOB AND SFC HI PRES/RDG AXIS UNDER THE UPR RDG.
FARTHER TO THE W...A STRONG DISTURBANCE HAS COME ASHORE INTO THE PAC
NW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 355 PM EDT WED MAR 28 2012
MAIN FCST CONCERNS IN THIS PERIOD ARE CLD/CLEARING TRENDS AND TEMPS.
TNGT...UPR RDG/SFC HI PRES RDG AXIS TO THE W ARE FCST TO BUILD INTO
THE UPR GRT LKS. WITH MORE ACYC FLOW AND SOME DRYING...EXPECT AT
LEAST PARTIAL CLRG ESPECIALLY IN DOWNSLOPE AREAS AWAY FM LK SUP IN
SLOWLY VEERING FLOW TO MORE NNE BY 12Z THU. BUT EXTENSIVE CLD COVER
UPSTREAM/LINGERING H925 THERMAL TROF SUGS THE SC WL BE MORE
RESILIENT IN UPSLOPE AREAS NEAR THE LAKE UNDER STRENGTHENING INVRN
ASSOCIATED WITH LARGER SCALE SUBSIDENCE. EXPECT THE LOWEST MIN TEMPS
WELL DOWN IN THE 20S OVER THE INTERIOR W WHERE MORE EXTENSIVE CLRG
IS MOST LIKELY.
THU...AS HI PRES IN ONTARIO DRIFTS SLOWLY TO THE E AND DISTURBANCE
NOW IN THE PAC NW/SFC LO MOVE TOWARD MN LATE...THE LLVL FLOW WL VEER
TO THE E THRU THE DAY. LINGERING LK SC SHOULD SHIFT TO MAINLY OVER
THE HURON MTNS/KEWEENAW AS MID/HIER CLD IN ADVANCE OF APRCHG
DISTURBANCE ARRIVE IN THE AFTN. THE GFS IS MOST AGGRESSIVE AT MOVING
PCPN E INTO THE WRN CWA IN THE AFTN...BUT WL FOLLOW THE SLOWER 12Z
NAM/CNDN/UKMET AND 00Z ECWMF WITH VERY DRY AIRMASS ASSOCIATED WITH
HUDSON BAY HI PRES IN PLACE AND GFS FCST SHARPER QVECTOR CNVGC/FGEN
HOLDING FARTHER TO THE W. MIXING TO H85 ON NAM FCST SDNGS YIELDS HI
TEMPS APRCHG 45 AWAY FM LK MODERATION.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM EDT WED MAR 28 2012
THURSDAY NIGHT INTO FRIDAY...SHORTWAVE TROUGH OVER THE NORTHERN
PLAINS POISED TO SLIDE THROUGH THE WESTERN GREAT LAKES BY LATE
THURSDAY NIGHT. INITIALLY JUST TO THE WEST OF CWA LARGE SCALE LIFT
FM THE SHORTWAVE IS COMPLEMENTED NICELY BY 925-850MB WARM AIR
ADVECTION AND DIVERGENCE ALOFT FM JET STREAK OVR ONTARIO. ALL THIS
FORCING IS ACTING ON RATHER MOIST AIRMASS WITH PWATS UP TOWARD 200
PCT OF NORMAL. SINCE PRIMARY SHORTWAVE IS SLIDING MAINLY SOUTH OF
UPR MI AND RIGHT ENTRANCE REGION/H85 THERMAL GRADIENT FADES THROUGH
THE NIGHT...WOULD EXPECT PCPN TO LIGHTEN AS IT MOVES INTO THE CWA
OVERNIGHT. FCST SOUNDINGS POINT TO PTYPE MAINLY TAKING THE FORM OF
SNOW WITH VERY LITTLE IN WAY OF NEAR SFC WARM LAYER ON SOUNDINGS.
BASED ON PREVIOUS MODEL RUNS THIS REPRESENTS A TREND IN THE COOLER
DIRECTION. EXPLICIT QPF OUTPUT WITH THE COLDER TREND WOULD SUGGEST A
FEW INCHES OF SNOW POSSIBLE IN THE INTERIOR WEST OVERNIGHT THURSDAY
NIGHT INTO EARLY FRIDAY. WILL NOT GO WITH THAT MUCH QPF/SNOW YET
THOUGH BASED ON NEGATIVE FACTORS MENTIONED BEFORE. STILL...COULD
SEE AROUND AN INCH OF SNOW OVER INTERIOR WEST AND SCNTRL. MAJORITY
OF PCPN SHOULD EXIT THE SCNTRL/EASTERN CWA FRIDAY AFTN. PLENTY OF
CLOUDS WITH THE PCPN ALONG WITH SE WIND OFF LK MICHIGAN WILL HOLD
DOWN TEMPERATURES OVR MOST OF THE CWA IN THE LOWER-MID 40S.
SHORTWAVE TROUGH SLIDES BY OVER CNTRL CANADA ON SATURDAY BUT MAIN
IMPACTS FM DISTURBANCE FCST TO REMAIN MOSTLY NORTH OF CWA WHERE BEST
LOW-LEVEL WARM ADVECTION OCCURS AND ALONG AND EAST OF TRACK OF
SHORTWAVE. DO HAVE SOME SMALL CHANCES FOR SHOWERS /JUST RAIN AT THIS
POINT/ OVER LK SUPERIOR AND IN NORTHERN CWA ON SATURDAY NIGHT.
IN THE EXTENDED...PIECE OF BROAD UPPER TROUGH OVER THE NORTHERN
PACIFIC IS FORECAST TO EJECT ACROSS THE ROCKIES ON SUNDAY. TROUGH
AND ASSOCIATED DEEPENING SFC LOW THEN SLIDE INTO THE UPR LAKES ON
MONDAY. DETERMINISTIC MEDIUM RANGE MODELS /GFS/ECMWF/CANADIAN/
INDICATE THAT THE UPPER LOW SLOWS UP EARLY NEXT WEEK AND MAY EVEN
TRY TO CUT OFF OVR UPR LAKES AND/OR ONTARIO. NCEP PREFERS THE SLOWER
APPROACH AS MODELS HAVE TRENDED THAT WAY. EVENTUALLY GENERAL RESULT
WILL BE COOLER AND UNSETTLED WEATHER PATTERN THROUGH MIDDLE OF NEXT
WEEK. INITIALLY THOUGH...MONDAY COULD BE ON THE WARMER SIDE OUT
AHEAD OF UPR LOW. ECMWF AND GFS DIFFER ON DETAILS AS GFS SHOWS MUCH
MORE IN WAY OF CLOUDS AND LIGHTER QPF SUNDAY NIGHT INTO MONDAY
MORNING WHILE ECMWF INDICATES A SHARPER COLD FRONT WITH GREATER
POTENTIAL FOR CONVECTION JUST AHEAD OF THE FRONT WITH H7-H5 LAPSE
RATES TO 7C/KM AND SI/S BLO 0C. THERE ALSO APPEARS TO BE ENHANCED
CONVECTIVE POTENTIAL DUE TO SHARPER 1000-850MB MOISTURE FLUX
CONVERGENCE FCST IN AFTN DURING PEAK HEATING. LATEST GFS HAS TRENDED
WARMER WITH INCREASED CHANCE OF CONVECTION. HAVE INTRODUCED CHANCES
FOR THUNDER...FIRST ON SUNDAY NIGHT FOR POSSIBLE ELEVATED CONVECTION
ON EDGE OF INSTABILITY GRADIENT AND THEN ON MONDAY WITH THE FROPA.
COLDER AIR WORKS IN FOR TUESDAY AND WEDNESDAY. GFS IS BROADER AND
LESS AMPLIFIED WITH OVERALL TROUGH WHILE ECMWF INDICATES COOLER AIR
SLOWLY MOVING IN ON TUESDAY WITH STRONGER SHOT OF COLD AIR ARRIVING
BY WEDNESDAY WITH SHARPER COLD FRONT FCST. ALTHOUGH CONSISTENCY IN
HANDLING OF THE TROUGH FM THE MODELS HAS BEEN MUDDLED...DOES APPEAR
TO BE A TREND IN HOLDING ON TO THE TROUGH LONGER AND KEEPING COOLER
TEMPERATURES OVER GREAT LAKES LONGER FURTHER INTO THE WEEK. TREND
MAKES SOME SENSE GIVEN THE AMPLIFIED PATTERN THAT APPEARS TO BE
SETTING UP COMPARED TO MORE ZONAL PATTERN IN PLACE CURRENTLY.
LATEST ECMWF SLOWER YET IN KEEPING COOL TROUGHING OVER GREAT LAKES
AND NORTHEAST INTO LATE NEXT WEEK. TRYING TO PIN DOWN DETAILS TOUGH
AT THIS POINT...BUT THIS KIND OF PATTERN WOULD HAVE POTENTIAL TO
BRING RAIN/SNOW SHOWERS TO UPR LAKES...ENHANCED BY DAYTIME HEATING
AND/OR ANY SHORTWAVES MOVING AROUND THE TROUGH. CONSENSUS POPS SHOW
SMALL CHANCES THROUGH MUCH OF THE EXTENDED WHICH SEEMS ON TRACK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1258 AM EDT THU MAR 29 2012
ALTHOUGH ACYC FLOW/SOME LOW LEVEL DRYING HAVE BROUGHT CIGS UP INTO
THE VFR RANGE. HOWEVER...A RETURN TO MVFR CIGS IS EXPECTED OVERNIGHT
AT SAW AND CMX AS NE OR ENE UPSLOPE FLOW DEVELOPS AS WINDS BACK.
BY THURSDAY AFTERNOON...EXPECT ANY LINGERING MVFR CIGS TO SCATTER
OUT AS MIXING/DRYING INCREASES. MID CLOUDS WILL THICKEN THIS EVENING
AHEAD OF A WARM FRONT TO THE SOUTHWEST. HOWEVER...ANY LOWER CIGS
VSBY WITH PCPN MOVING INTO THE AREA SHOULD HOLD OFF UNTIL AFTER THE
TAF PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT WED MAR 28 2012
EXPECT NW WINDS UP TO 30 KTS EARLY OVER THE E HALF TO DIMINISH
TONIGHT AS HI PRES RIDGE BUILDS OVERHEAD. AS THE HI CENTER SHIFTS
EWD TOWARD HUDSON BAY ON THU...A STRONGER E WIND UP TO 25 KTS WILL
DEVELOP OVER WESTERN LK SUP WHERE TERRAIN ENHANCES THIS FLOW. GUSTY
EAST WINDS SHOULD CONTINUE ON THE LAKE INTO FRIDAY MORNING. AFTER A
BRIEF LULL...SOUTH WINDS INCREASE TO 30 KTS ON EAST HALF OF LK
SUPERIOR BY SATURDAY AFTN. WINDS SHOULD SETTLE DOWN INTO SUNDAY AS
PRESSURE GRADIENT WEAKENS. ANOTHER LOW PRESSURE SYSTEM...POSSIBLY
SLOW MOVING...IS EXPECTED TO AFFECT THE WESTERN GREAT LAKES EARLY
NEXT WEEK. COULD SEE WINDS UP TO 30 KTS WITH THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...07
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1215 AM EDT THU MAR 29 2012
.UPDATE...
ISSUED AT 1214 AM EDT THU MAR 29 2012
RAISED LOW TEMPERATURES A BIT AS CLOUD COVER LOOKS TO BE STUBBORN
AND SLOW TO LEAVE. ALSO KEPT CLOUDS IN FOR THE REST OF TONIGHT
ALMOST EVERYWHERE EXCEPT THE FAR WEST AND SOUTH AS DRIER AIR WORKS
IN.
&&
.SYNOPSIS...
ISSUED AT 355 PM EDT WED MAR 28 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE UPR GRT LKS DOWNSTREAM OF UPR RIDGE IN THE PLAINS. SHRTWV/SFC LO
THAT IMPACTED THE AREA YDAY IS NOW MOVING E THRU QUEBEC...BUT CYC
SFC-H85 NW FLOW OF MOIST AIR REMAINS IN PLACE OVER THE UPR GRT LKS.
A SHRTWV OVER MN IS MOVING SEWD...AND IN CONCERT WITH SOME DEEPER
MSTR SHOWN ON THE 12Z INL RAOB HAS CAUSED SOME SCT -SHRA THAT ARE
MIXING WITH SN AS COLDER AIR ARRIVES FM THE NW...WHERE THE 12Z H85
TEMP WAS AS LO AS -9C AT YPL. BUT UPSTREAM RAOBS SHOW MID LVL DRYING
IN THE WAKE OF THE SHRTWV IS SPREADING SEWD TOWARD THE UPR GRT LKS.
DESPITE THE HIER LVL DRYING...MUCH LO CLD LINGERS IN THE LLVL CYC
FLOW OF THE MOISTER LLVLS DEPICTED ON THE 12Z INL/YPL RAOBS. SOME
CLEARING IS SHOWING UP OVER MANITOBA CLOSER TO DRIER LLVL AIR SHOWN
ON THE 12Z THE PAS RAOB AND SFC HI PRES/RDG AXIS UNDER THE UPR RDG.
FARTHER TO THE W...A STRONG DISTURBANCE HAS COME ASHORE INTO THE PAC
NW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 355 PM EDT WED MAR 28 2012
MAIN FCST CONCERNS IN THIS PERIOD ARE CLD/CLEARING TRENDS AND TEMPS.
TNGT...UPR RDG/SFC HI PRES RDG AXIS TO THE W ARE FCST TO BUILD INTO
THE UPR GRT LKS. WITH MORE ACYC FLOW AND SOME DRYING...EXPECT AT
LEAST PARTIAL CLRG ESPECIALLY IN DOWNSLOPE AREAS AWAY FM LK SUP IN
SLOWLY VEERING FLOW TO MORE NNE BY 12Z THU. BUT EXTENSIVE CLD COVER
UPSTREAM/LINGERING H925 THERMAL TROF SUGS THE SC WL BE MORE
RESILIENT IN UPSLOPE AREAS NEAR THE LAKE UNDER STRENGTHENING INVRN
ASSOCIATED WITH LARGER SCALE SUBSIDENCE. EXPECT THE LOWEST MIN TEMPS
WELL DOWN IN THE 20S OVER THE INTERIOR W WHERE MORE EXTENSIVE CLRG
IS MOST LIKELY.
THU...AS HI PRES IN ONTARIO DRIFTS SLOWLY TO THE E AND DISTURBANCE
NOW IN THE PAC NW/SFC LO MOVE TOWARD MN LATE...THE LLVL FLOW WL VEER
TO THE E THRU THE DAY. LINGERING LK SC SHOULD SHIFT TO MAINLY OVER
THE HURON MTNS/KEWEENAW AS MID/HIER CLD IN ADVANCE OF APRCHG
DISTURBANCE ARRIVE IN THE AFTN. THE GFS IS MOST AGGRESSIVE AT MOVING
PCPN E INTO THE WRN CWA IN THE AFTN...BUT WL FOLLOW THE SLOWER 12Z
NAM/CNDN/UKMET AND 00Z ECWMF WITH VERY DRY AIRMASS ASSOCIATED WITH
HUDSON BAY HI PRES IN PLACE AND GFS FCST SHARPER QVECTOR CNVGC/FGEN
HOLDING FARTHER TO THE W. MIXING TO H85 ON NAM FCST SDNGS YIELDS HI
TEMPS APRCHG 45 AWAY FM LK MODERATION.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM EDT WED MAR 28 2012
THURSDAY NIGHT INTO FRIDAY...SHORTWAVE TROUGH OVER THE NORTHERN
PLAINS POISED TO SLIDE THROUGH THE WESTERN GREAT LAKES BY LATE
THURSDAY NIGHT. INITIALLY JUST TO THE WEST OF CWA LARGE SCALE LIFT
FM THE SHORTWAVE IS COMPLEMENTED NICELY BY 925-850MB WARM AIR
ADVECTION AND DIVERGENCE ALOFT FM JET STREAK OVR ONTARIO. ALL THIS
FORCING IS ACTING ON RATHER MOIST AIRMASS WITH PWATS UP TOWARD 200
PCT OF NORMAL. SINCE PRIMARY SHORTWAVE IS SLIDING MAINLY SOUTH OF
UPR MI AND RIGHT ENTRANCE REGION/H85 THERMAL GRADIENT FADES THROUGH
THE NIGHT...WOULD EXPECT PCPN TO LIGHTEN AS IT MOVES INTO THE CWA
OVERNIGHT. FCST SOUNDINGS POINT TO PTYPE MAINLY TAKING THE FORM OF
SNOW WITH VERY LITTLE IN WAY OF NEAR SFC WARM LAYER ON SOUNDINGS.
BASED ON PREVIOUS MODEL RUNS THIS REPRESENTS A TREND IN THE COOLER
DIRECTION. EXPLICIT QPF OUTPUT WITH THE COLDER TREND WOULD SUGGEST A
FEW INCHES OF SNOW POSSIBLE IN THE INTERIOR WEST OVERNIGHT THURSDAY
NIGHT INTO EARLY FRIDAY. WILL NOT GO WITH THAT MUCH QPF/SNOW YET
THOUGH BASED ON NEGATIVE FACTORS MENTIONED BEFORE. STILL...COULD
SEE AROUND AN INCH OF SNOW OVER INTERIOR WEST AND SCNTRL. MAJORITY
OF PCPN SHOULD EXIT THE SCNTRL/EASTERN CWA FRIDAY AFTN. PLENTY OF
CLOUDS WITH THE PCPN ALONG WITH SE WIND OFF LK MICHIGAN WILL HOLD
DOWN TEMPERATURES OVR MOST OF THE CWA IN THE LOWER-MID 40S.
SHORTWAVE TROUGH SLIDES BY OVER CNTRL CANADA ON SATURDAY BUT MAIN
IMPACTS FM DISTURBANCE FCST TO REMAIN MOSTLY NORTH OF CWA WHERE BEST
LOW-LEVEL WARM ADVECTION OCCURS AND ALONG AND EAST OF TRACK OF
SHORTWAVE. DO HAVE SOME SMALL CHANCES FOR SHOWERS /JUST RAIN AT THIS
POINT/ OVER LK SUPERIOR AND IN NORTHERN CWA ON SATURDAY NIGHT.
IN THE EXTENDED...PIECE OF BROAD UPPER TROUGH OVER THE NORTHERN
PACIFIC IS FORECAST TO EJECT ACROSS THE ROCKIES ON SUNDAY. TROUGH
AND ASSOCIATED DEEPENING SFC LOW THEN SLIDE INTO THE UPR LAKES ON
MONDAY. DETERMINISTIC MEDIUM RANGE MODELS /GFS/ECMWF/CANADIAN/
INDICATE THAT THE UPPER LOW SLOWS UP EARLY NEXT WEEK AND MAY EVEN
TRY TO CUT OFF OVR UPR LAKES AND/OR ONTARIO. NCEP PREFERS THE SLOWER
APPROACH AS MODELS HAVE TRENDED THAT WAY. EVENTUALLY GENERAL RESULT
WILL BE COOLER AND UNSETTLED WEATHER PATTERN THROUGH MIDDLE OF NEXT
WEEK. INITIALLY THOUGH...MONDAY COULD BE ON THE WARMER SIDE OUT
AHEAD OF UPR LOW. ECMWF AND GFS DIFFER ON DETAILS AS GFS SHOWS MUCH
MORE IN WAY OF CLOUDS AND LIGHTER QPF SUNDAY NIGHT INTO MONDAY
MORNING WHILE ECMWF INDICATES A SHARPER COLD FRONT WITH GREATER
POTENTIAL FOR CONVECTION JUST AHEAD OF THE FRONT WITH H7-H5 LAPSE
RATES TO 7C/KM AND SI/S BLO 0C. THERE ALSO APPEARS TO BE ENHANCED
CONVECTIVE POTENTIAL DUE TO SHARPER 1000-850MB MOISTURE FLUX
CONVERGENCE FCST IN AFTN DURING PEAK HEATING. LATEST GFS HAS TRENDED
WARMER WITH INCREASED CHANCE OF CONVECTION. HAVE INTRODUCED CHANCES
FOR THUNDER...FIRST ON SUNDAY NIGHT FOR POSSIBLE ELEVATED CONVECTION
ON EDGE OF INSTABILITY GRADIENT AND THEN ON MONDAY WITH THE FROPA.
COLDER AIR WORKS IN FOR TUESDAY AND WEDNESDAY. GFS IS BROADER AND
LESS AMPLIFIED WITH OVERALL TROUGH WHILE ECMWF INDICATES COOLER AIR
SLOWLY MOVING IN ON TUESDAY WITH STRONGER SHOT OF COLD AIR ARRIVING
BY WEDNESDAY WITH SHARPER COLD FRONT FCST. ALTHOUGH CONSISTENCY IN
HANDLING OF THE TROUGH FM THE MODELS HAS BEEN MUDDLED...DOES APPEAR
TO BE A TREND IN HOLDING ON TO THE TROUGH LONGER AND KEEPING COOLER
TEMPERATURES OVER GREAT LAKES LONGER FURTHER INTO THE WEEK. TREND
MAKES SOME SENSE GIVEN THE AMPLIFIED PATTERN THAT APPEARS TO BE
SETTING UP COMPARED TO MORE ZONAL PATTERN IN PLACE CURRENTLY.
LATEST ECMWF SLOWER YET IN KEEPING COOL TROUGHING OVER GREAT LAKES
AND NORTHEAST INTO LATE NEXT WEEK. TRYING TO PIN DOWN DETAILS TOUGH
AT THIS POINT...BUT THIS KIND OF PATTERN WOULD HAVE POTENTIAL TO
BRING RAIN/SNOW SHOWERS TO UPR LAKES...ENHANCED BY DAYTIME HEATING
AND/OR ANY SHORTWAVES MOVING AROUND THE TROUGH. CONSENSUS POPS SHOW
SMALL CHANCES THROUGH MUCH OF THE EXTENDED WHICH SEEMS ON TRACK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 748 PM EDT WED MAR 28 2012
ALTHOUGH MORE ACYC FLOW/SOME LOW LEVEL DRYING WILL RESULT KEEP VFR
CONDITIONS AT CMX/IWD. HOWEVER...MVFR CONDITIONS SHOULD LINGER
TONIGHT THROUGH THU MORNING AT KSAW WHERE MORE UPSLOPE FLOW
PREVAILS. A RETURN TO MVFR CIGS MAY ALSO BE POSSIBLE AT KCMX AS
WINDS BACK MORE TO THE ENE. BY THURSDAY AFTERNOON...EXPECT ANY
LINGERING MVFR CIGS TO SCATTER OUT AS MIXING/DRYING INCREASES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT WED MAR 28 2012
EXPECT NW WINDS UP TO 30 KTS EARLY OVER THE E HALF TO DIMINISH
TONIGHT AS HI PRES RIDGE BUILDS OVERHEAD. AS THE HI CENTER SHIFTS
EWD TOWARD HUDSON BAY ON THU...A STRONGER E WIND UP TO 25 KTS WILL
DEVELOP OVER WESTERN LK SUP WHERE TERRAIN ENHANCES THIS FLOW. GUSTY
EAST WINDS SHOULD CONTINUE ON THE LAKE INTO FRIDAY MORNING. AFTER A
BRIEF LULL...SOUTH WINDS INCREASE TO 30 KTS ON EAST HALF OF LK
SUPERIOR BY SATURDAY AFTN. WINDS SHOULD SETTLE DOWN INTO SUNDAY AS
PRESSURE GRADIENT WEAKENS. ANOTHER LOW PRESSURE SYSTEM...POSSIBLY
SLOW MOVING...IS EXPECTED TO AFFECT THE WESTERN GREAT LAKES EARLY
NEXT WEEK. COULD SEE WINDS UP TO 30 KTS WITH THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...07
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
317 AM CDT THU MAR 29 2012
.DISCUSSION...
TEMPERATURES THIS MORNING ARE FINALLY NEAR NORMAL IN A FEW
AREAS ESPECIALLY OVER WEST CENTRAL WISCONSIN WHERE SOME UPPER 20S
TO LOW 30S WERE NOTED...COURTESY OF HIGH PRESSURE AND CLEAR SKIES.
FREEZE WARNING LOOKS GOOD THIS MORNING. ELSEWHERE....INCREASING
MID LEVEL CLOUDS OVER NORTH DAKOTA AND NORTHWEST MINNESOTA IN ZONE
OF DEVELOPING WARM ADVECTION AND MID LEVEL THETA E ADVECTION.
A FEW RETURNS SHOWING UP IN THE REGION BUT SATURATION A FEW HOURS
AWAY YET. THE 06Z RUC SEEMS TO HAVE A DECENT TREND ON THE
INCREASING FGEN FORCING THIS MORNING FOR WEST CENTRAL MINNESOTA.
LOW LOWER LEVEL MOISTURE TRANSPORT STILL BOTTLED UP OVER THE
CENTRAL PLAINS. HAVE DELAYED POPS A BIT TODAY UNTIL THE WAVE OVER
EASTERN ID AND WESTERN WY GETS CLOSER ALONG WITH SOME OF THE
MOISTURE TRANSPORT REACHING IOWA. THE GFS AND NAM BOTH SHOW
PRECIPITABLE WATER VALUES REACHING JUST OVER AN INCH BY 00Z AT MSP
WHICH IS NEAR 2 STANDARD DEVIATIONS ABOVE NORMAL. HAVE RAISED POPS
BY EVENING INTO THE CATEGORICAL AREA OVER AT LEAST THE CENTRAL CWA
AND THEN FARTHER EAST INTO WISCONSIN LATER IN THE EVENING. THE GFS
IS A LITTLE FASTER WITH THE WAVE BUT NOT BY MUCH. MOST LINGERING
PRECIP SHOULD BE CONFINED TO A FEW AREAS OF WEST CENTRAL WISCONSIN
BY FRIDAY MORNING. BEST CHANCE OF ISOLATED THUNDER OVER WEST
CENTRAL MN THIS MORNING INTO THE AFTERNOON WITH THE INITIAL BURST
OF WARM ADVECTION AND THEN MAINLY SOUTHERN HALF OF THE CWA IN THE
AFTERNOON AND EVENING NEAR THE EDGE OF THE DEEPER INSTABILITY
TO UR SOUTH.
LOOKS LIKE LINGERING CLOUDS EASTERN AREAS FRIDAY INTO SATURDAY
MORNING WITH THE DEVELOPING STRONGER WARM FRONT. A LITTLE
CONCERNED ABOUT A FEW SHOWERS DEVELOPING LATER FRIDAY NIGHT AND
SATURDAY MORNING NEAR THE FRONT. WILL LEAVE OUT FOR NOW WITH THE
INITIAL DRIER BEHIND THE DEPARTING WAVE LATER TONIGHT.
STILL LOOKS WARM FOR THE WEEKEND...ESPECIALLY SUNDAY DEEP INTO THE
WARM SECTOR. MIXING DOWN FROM AROUND 875-900MB EVEN YIELDS SOME
LOWER 80S ON THE SOUTH. CHANCES FOR TSTMS LOOK SLIM WITH A CAPPED
ENVIRONMENT INTITIALLY BUT SUNDAY NIGHT LOOKS BETTER EASTERN AREAS.
&&
.AVIATION.../06Z TAF ISSUANCE/
JUST SOME PATCHY CIRRUS CLOUDS OVERNIGHT BEFORE MID DECK OF CLOUDS
ROLL INTO WESTERN MN BY MID OR LATE MORNING. WEATHER CONDITIONS
REMAINING VFR THROUGH MID AFTERNOON THURSDAY...THEN SCATTERED SHRA
DEVELOPING AHEAD OF LOW PRESSURE TROUGH. SOME WEAK INSTABILITY OVER
THE FORECAST AREA THURSDAY AFTERNOON/EVENING. ONLY EXPECT SOME
ISOLATED THUNDERSTORMS EMBEDDED IN THE AREA OF RAINSHOWERS.
THERE ARE HIGHER PROBABILITIES FOR THUNDERSTORMS WELL TO THE SOUTH
OF THE AREA WHERE THE INSTABILITY WILL MUCH BETTER. ONCE THE SHOWERS
MOVE IN...THERE IS ROUGHLY A 3-5 HOUR WINDOW WHEN THE TAF SITES
COULD SEE THE RAIN. A LOT OF 5000-7000 CEILINGS TOMORROW...WITH
POTENTIAL FOR CEILINGS TO LOWER TO 3000-4000FT UNDER THE HEAVIER
SHOWER AND PERHAPS BRIEFLY YIELDING A 4-5SM VISIBILITY. MUCH BETTER
CHANCES FOR MVFR CEILINGS BEHIND THE SHOWERS THURSDAY NIGHT.
KMSP...NO PROBLEM TONIGHT THROUGH THURSDAY AFTERNOON. VFR FLYING
CONDITIONS PREVAILING THROUGH THE BULK OF THE PERIOD. RAIN
DEVELOPING AFTER 400 PM...WITH POSSIBLY AN EMBEDDED THUNDERSTORM
BEFORE MIDNIGHT. CEILINGS COULD LOWER BRIEFLY AROUND 3000-4000 FEET
AGL AND VISIBILITIES 5 TO 6 MILES IN HEAVIER SHOWERS ESPECIALLY
TOMORROW EVENING.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR BARRON-CHIPPEWA-
DUNN-EAU CLAIRE-POLK-RUSK.
&&
$$
JPR/JVM
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1203 AM CDT THU MAR 29 2012
.UPDATE...
ISSUED AT 933 PM CDT WED MAR 28 2012
ISOLATED SHOWERS AND STORMS CONTINUE TO DEVELOP ALONG FRONTAL
BOUNDARY WHICH EXTENDS FROM JUST S OF MCI SE THROUGH FAM. MORE
ORGANIZED CONVECTION WAS ACROSS ERN KS INTO W CNTRL MO JUST E OF
A SLY LOW LEVEL JET AXIS AND JUST AHEAD OF A WEAK SHORTWAVE OVER
SRN NEBRASKA AND NRN KANSAS. THIS ACTIVITY SHOULD SHIFT EWD TGT
WITH THE STRONGER STORMS IMPACTING CNTRL MO...AND WEAKER SHOWERS
AND STORMS FURTHER N MOVING EWD INTO NERN MO. AS THIS ACTIVITY
SPREADS EWD LATE TGT IT SHOULD WEAKEN AS IT GETS INTO ERN MO AND
ENCOUNTERS LESS LOW LEVEL MOISTURE AND INSTABILITY. WILL CONTINUE
WITH THE HIGHEST POPS OVER CNTRL MO INTO SERN MO NEAR THE
FRONT...WITH LITTLE IF ANY POPS OVER THE IL COUNTIES OF OUR
FORECAST AREA WITH A SFC RIDGE EXTENDING SWD THROUGH WI AND IL.
GKS
&&
.SHORT TERM...
ISSUED AT 320 PM CDT WED MAR 28 2012
(TONIGHT THROUGH FRIDAY)
PRIMARY CONCERN IN THE SHORT TERM IS POPS TONIGHT THROUGH FRIDAY.
QUASI-STATIONARY FRONT EXTENDS FROM NEAR FARMINGTON WEST-NORTHWEST
BETWEEN COLUMBIA AND SEDALIA TO NEAR TOPEKA. UNSTABLE AIRMASS IS
EVIDENT IN CUMULUS FIELD SOUTH OF THE FRONT AND SHOWERS ARE ALREADY
BREAKING OUT SOUTH OF THE ST LOUIS METRO AREA. EXPECT WIDELY
SCATTERED SHOWERS TO CONTINUE ALONG AND SOUTH OF THE FRONT THIS
AFTERNOON AND INTO THIS EVENING...BUT THE MAIN SHOW WILL DEVELOP
ACROSS SOUTHERN NEBRASKA AND NORTHERN KANSAS WHERE INSTABILITY AND
FORCING IS GREATEST. SOME QUESTION AS TO WHAT CONVECTIVE MODE THE
STORMS WILL ULTIMATELY TAKE. INSTABILITY AND SHEAR IS GREAT ENOUGH
FOR SOME ORGANIZATION...AND THE HRRR HAS ALTERNATELY BEEN DEVELOPING
DISCRETE SUPERCELLS...BOW ECHOS...AND OCCASIONALLY MULTICELL
CLUSTERS. THINK EITHER THE MULTICELL CLUSTER OR BOW ECHO IS MOST
LIKELY. FORWARD PROPAGATING CORFIDI VECTORS WOULD MOVE ANY MCS THAT
DEVELOPS EAST-SOUTHEAST INTO WESTERN MISSOURI. STORMS SHOULD RUN
OUT OF INSTABILITY AS THEY APPROACH CENTRAL MISSOURI AND SHOULD BE
IN THE WANING PHASE. WILL CONTINUE THE CHANCE FOR WIDELY SCATTERED
THUNDERSTORMS ON THURSDAY AS FRONT LIFTS BACK ACROSS THE AREA...THEN
ANOTHER SHOT OF PRECIP THURSDAY NIGHT AS A SHORTWAVE RIPPLES ACROSS
IOWA AND MISSOURI ACCOMPANIED BY ANOTHER WEAK COLD FRONT.
CARNEY
&&
.LONG TERM...
ISSUED AT 320 PM CDT WED MAR 28 2012
(SATURDAY THROUGH WEDNESDAY)
PRIMARY CONCERN IN THE SHORT TERM IS POPS TONIGHT THROUGH FRIDAY.
QUASI-STATIONARY FRONT EXTENDS FROM NEAR FARMINGTON WEST-NORTHWEST
BETWEEN COLUMBIA AND SEDALIA TO NEAR TOPEKA. UNSTABLE AIRMASS IS
EVIDENT IN CUMULUS FIELD SOUTH OF THE FRONT AND SHOWERS ARE ALREADY
BREAKING OUT SOUTH OF THE ST LOUIS METRO AREA. EXPECT WIDELY
SCATTERED SHOWERS TO CONTINUE ALONG AND SOUTH OF THE FRONT THIS
AFTERNOON AND INTO THIS EVENING...BUT THE MAIN SHOW WILL DEVELOP
ACROSS SOUTHERN NEBRASKA AND NORTHERN KANSAS WHERE INSTABILITY AND
FORCING IS GREATEST. SOME QUESTION AS TO WHAT CONVECTIVE MODE THE
STORMS WILL ULTIMATELY TAKE. INSTABILITY AND SHEAR IS GREAT ENOUGH
FOR SOME ORGANIZATION...AND THE HRRR HAS ALTERNATELY BEEN DEVELOPING
DISCRETE SUPERCELLS...BOW ECHOS...AND OCCASIONALLY MULTICELL
CLUSTERS. THINK EITHER THE MULTICELL CLUSTER OR BOW ECHO IS MOST
LIKELY. FORWARD PROPAGATING CORFIDI VECTORS WOULD MOVE ANY MCS THAT
DEVELOPS EAST-SOUTHEAST INTO WESTERN MISSOURI. STORMS SHOULD RUN
OUT OF INSTABILITY AS THEY APPROACH CENTRAL MISSOURI AND SHOULD BE
IN THE WANING PHASE. WILL CONTINUE THE CHANCE FOR WIDELY SCATTERED
THUNDERSTORMS ON THURSDAY AS FRONT LIFTS BACK ACROSS THE AREA...THEN
ANOTHER SHOT OF PRECIP THURSDAY NIGHT AS A SHORTWAVE RIPPLES ACROSS
IOWA AND MISSOURI ACCOMPANIED BY ANOTHER WEAK COLD FRONT.
THE FRONT WILL CONTINUE SOUTH INTO THE LOWER MISSISSIPPI VALLEY BY
SATURDAY BRINGING AN END TO THE PRECIP CHANCES FOR THE WEEKEND.
TEMPERATURES SHOULD REMAIN ABOVE NORMAL IN THE UPPER 70S TO THE
LOWER 80S. A SHARP TROF WILL DEVELOP OVER THE PLAINS SUNDAY NIGHT
INTO MONDAY WITH SURFACE CYCLOGENESIS TAKING PLACE OVER THE
NORTHEAST PLAINS OR THE UPPER MIDWEST. SOME TIMING DIFFERENCES ON
MEDIUM RANGE MODELS IS MAKING PRECIP TIMING DIFFICULT...BUT EXPECT
SHOWERS AND THUNDERSTORMS TO BE IN THE AREA MONDAY AND MONDAY
NIGHT...POSSIBLY LINGERING INTO TUESDAY. EXPECTING TEMPERATURES
BEHIND THE FRONT TO BE MORE SEASONABLE IN THE 60S AND LOWER 70S.
CARNEY
&&
.AVIATION...
ISSUED AT 1142 PM CDT WED MAR 28 2012
SHOWERS AND THUNDERSTORMS HAVE BOTH MOVED AND DEVELOPED FURTHER
EAST THAN EXPECTED THIS EVENING AND WERE SCATTERED ACROSS CENTRAL
MO TO AROUND 40-50 MILES WEST OF ST LOUIS. A BAND OF STRONGER AND
BETTER ORGANIZED THUNDERSTORMS WAS LOCATED THROUGH WEST CENTRAL
MO. ALL OF THIS ACTIVITY WAS OCCURING ALONG AND NORTH OF A
STATIONARY FRONT LOCATED ACORSS SOUTHERN MISSOURI AND SOUTHERN
ILLINOIS. THE SCATTERED ACTIVITY SHOULD GRADUALLY BE ENCOUNTERING
A MORE STABLE AIR MASS AS IT MOVES EAST SOUTHEAST. I HAVE ADDED A
-SHRA OR VCSH OVERNIGHT FOR THE ST LOUIS AREA TAFS GIVEN THE
SCATTERED COVERAGE AND UNCERTAINTY ABOUT A MORE DIRECT IMPACT AT
THE TERMINALS. KCOU HAS ALREADY SEEN SOME LIGHT RAIN AND THUNDER
AND THEY APPEAR TO BE IN LINE FOR ANOTHER STRONGER ROUND
OVERNIGHT. I THINK SOME OF THE ACTIVITY OVER NORTHWEST MO MAY HOLD
TOGETHER AS IT MOVES EAST AND IMPACT KUIN JUST AFTER DAYBREAK. I
THINK ALL THE PRECIPITATION WILL HAVE MOVED TO THE EAST BY MID
MORNING IF NOT SOONER WITH VFR CONDITIONS DOMINATING THE REMAINDER
OF THE TAF PERIOD.
SPECIFICS FOR KSTL...
SHOWERS AND THUNDERSTORMS HAVE BOTH MOVED AND DEVELOPED FURTHER
EAST THAN EXPECTED THIS EVENING AND WERE SCATTERED ACROSS CENTRAL
MO TO AROUND 40-50 MILES WEST OF ST LOUIS. THIS SCATTERED
ACTIVITY SHOULD GRADUALLY BE ENCOUNTERING A MORE STABLE AIR MASS
AS IT MOVES EAST SOUTHEAST. I HAVE ADDED -SHRA FOR A PERIOD OVERNIGHT
GIVEN THE SCATTERED COVERAGE AND UNCERTAINTY ABOUT A MORE DIRECT
IMPACT AT THE TERMINALS. I THINK ALL THE PRECIPITATION WILL HAVE
MOVED TO THE EAST OR DISSIPATED BY DAYBREAK IF NOT SOONER WITH VFR
CONDITIONS DOMINATING THE REMAINDER OF THE TAF PERIOD.
GLASS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1127 PM CDT WED MAR 28 2012
.AVIATION...
06Z TAFS FOR KOMA...KLNK AND KOFK.
SOME CONVECTIVE POTENTIAL WILL EXIST THROUGH MUCH OF THE PERIOD
AT ALL THREE SITES. WARM FRONT LOCATED SOUTH OF THE AREA AT 06Z
WILL LIFT NORTHEAST TONIGHT IN ADVANCE A COLD FRONT MOVING INTO
THE AREA ON THURSDAY AFTER 18Z. ANOTHER ROUND OF CONVECTION
POSSIBLE WITH THE COLD FRONT BETWEEN 18Z AND 00Z.
&&
.PREV DISCUSSION... /ISSUED 1033 PM CDT WED MAR 28 2012/
DISCUSSION...
UPDATE THE FORECAST FOR TONIGHT TO DECREASE THE POPS ACROSS THE
NW CWA AND DELAYED THE ONSET OF THE LIKELY POPS INTO SW. OTHERWISE
THE GOING FORECAST IS IN GOOD SHAPE.
DISTINCT AND STRONG WARM FRONT AT 850 MB WAS RIGHT ALONG THE
KS/NEB BORDER THIS EVNG. THIS FNT WILL TRY AND LIFT NWD THROUGH
THE NIGHT AS THE LOW LEVEL JET INCREASES FROM KANSAS INTO SE NEB.
THIS INCREASE IN THE LOW LEVEL JET AND SUBSEQUENT INCREASE IN
MASS CONVERGENCE HAS BEEN RESPONSIBLE FOR THE INCREASE IN
CONVECTION NEAR THE THE BORDER WITH KS. LATEST RUC ANALYSIS INDCS
THAT THERE IS AROUND 1000 J/KG OF MUCAPE RIGHT ALONG THE BORDER
BUT RAPIDLY DROPS OFF FARTHER NORTH. THUS AS STORMS LIFT NWD INTO
THE AREA THEY CONT TO WEAKEN. THERE MAY BE A SLIGHT RISK FOR AN
ISOLATED LARGE HAIL /NEAR QUARTER SIZE/ ALONG THE BORDER...BUT
OTHERWISE THERE IS LITTLE SVR WX THREAT FARTHER NORTH. THE
INCREASE IN THE LOW LEVEL JET SHOULD FOCUS OVER SE NEB AND SW IA
AND THIS IS WHERE WE SHOULD SEE THE HIGHEST CONCENTRATE OF PRECIP.
SHOWERS AND ISO STORMS SHOULD LINGER INTO THU MRNG OVER SW IA. NO
ADDITIONAL UPDATES ARE PLANNED AT THE MOMENT.
BOUSTEAD
PREV DISCUSSION... /ISSUED 258 PM CDT WED MAR 28 2012/
DISCUSSION...
MAIN FORECAST PROBLEM TONIGHT WILL BE INCREASING CHANCES FOR CONVECTION
AS A WEAK IMPULSE EJECTING OFF THE HIGH PLAINS COMBINES WITH A NORTHWARD
ADVANCING WARM FRONT MOVING INTO THE REGION. ELEVATION CONVECTION
WAS ALREADY ONGOING ACROSS SOUTH CENTRAL NEBRASKA. BELIEVE THIS
WILL DEVELOP FURTHER EAST THROUGH THE EVENING ALONG THE NEBRASKA
AND KANSAS BORDER REGION...THUS HAVE INCREASED POPS IN THAT
REGION THROUGH THE EVENING. COORDINATED WITH SPC EARLIER THAT THE
SLIGHT RISK MAY NEED TO MOVED JUST SLIGHTLY NORTHWARD TO ACCOUNT
FOR SOME MARGINAL HAIL IN THAT AREA THIS EVENING. AS WE MOVE
TOWARD LATE EVENING AND OVERNIGHT...BELIEVE THAT THERE`S AT LEAST
A CHANCE OF ADDITIONAL ELEVATION CONVECTION FURTHER NORTH UP THE
MISSOURI RIVER...PUSHING SLOWLY EAST THROUGH DAYBREAK THURSDAY.
A FEW LINGERING SHOWERS OR ISOLATED STORMS MAY BE ONGOING EARLY
THURSDAY MORNING ALONG AND EAST OF THE MISSOURI RIVER...BUT MOST
OF EASTERN NEBRASKA MAY ACTUALLY BE DRY. BY MIDDAY THURSDAY...THE
WARM FRONT WILL PROBABLY BE LOCATED ALONG THE NE/KS BORDER REGION
AGAIN...WHILE A COLD FRONT ADVANCES FROM THE NORTHWEST. THE MAIN
SEVERE THREAT WILL BE ALONG THE WARM FRONT IN SOUTHEAST NEBRASKA
AND SOUTHWEST IOWA...BUT GIVEN SHEAR ALONG THE ADVANCING COLD
FRONT...WOULD EXPECT SOME HAIL POTENTIAL THERE AS WELL. PRECIP
CHANCES INCREASE NOTABLY THROUGH THE AFTERNOON THROUGH PEAK
HEATING. THERE STILL REMAINS SOME UNCERTAINTY HOW FAR NORTH THE
WARM FRONT WILL MOVE THOUGH. EVENING THUNDERSTORMS SHOULD CONTINUE
TO PUSH OUT OF HERE THROUGH MIDNIGHT TOMORROW NIGHT.
THEN WE WARM BACK UP FRIDAY AND SATURDAY AS RIDGING ALOFT BUILD
INTO THE AREA WITH DRY CONDITIONS THAT LINGER THROUGH SUNDAY WITH
HIGHS BACK INTO THE LOWER TO MID 80S. ANOTHER WAVE MOVES INTO THE
REGION SUNDAY NIGHT WITH AN ATTACHED COLD FRONT. THIS WILL BRING
ANOTHER CHANCE OF THUNDERSTORMS...AND POSSIBLY SOME LINGERING
SHOWERS ON MONDAY. MORE IMPORTANTLY...IT WILL BRING SHARPLY COOLER
TEMPERATURES AGAIN WITH HIGHS BACK IN THE LOWER TO MIDDLE 60S AND
LOWS IN THE UPPER 30S AND LOWER 40S...BUT DRY CONDITIONS.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
326 AM EDT THU MAR 29 2012
.SYNOPSIS...
A DRY COLD FRONT WILL CROSS NC TODAY AND SETTLE INTO SC TONIGHT. THE
FRONT WILL RETURN NORTHWARD AS A WARM FRONT ON FRIDAY...IN ADVANCE
OF A LOW PRESSURE SYSTEM AND TRAILING COLD FRONT THAT WILL CROSS THE
MIDDLE ATLANTIC STATES FRIDAY NIGHT THROUGH SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 10 PM EDT WEDNESDAY...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH AN APPROACHING COLD FRONT
HAVE REMAINED GENERALLY TO THE NORTH OF THE AREA THIS EVENING.
HOWEVER... THE LATEST HI-RES MODELS CONTINUE TO INDICATE SOME OF
THIS ACTIVITY MOVING INTO/DEVELOPING ACROSS OUR NORTHERN PIEDMONT
AND NORTHERN COASTAL PLAIN COUNTIES AS RAIN COOLED OUTFLOW FROM
CURRENT ACTIVITY ACROSS SOUTHERN VA HELPS TO OVERCOME THE NEAR
SURFACE STABLE LAYER. THIS ACTIVITY HAS DECREASED IN COVERAGE OVER
THE LAST SEVERAL HOURS THOUGH... THANKS IN PART TO A STABILIZING
BOUNDARY LAYER AND LACK OF ANY SIGNIFICANT UPPER DYNAMICS.
HOWEVER... GIVEN WESTERLY DEEP LAYER SHEAR OF AROUND 30 TO 40 KTS
AND STEEP MID LEVEL LAPSE RATES OF AROUND 7.5-8 DEGREES C/KM (WHICH
IS ALSO HELPING TO KEEP THE STORMS GOING) EXPECT WE COULD SEE SOME
STRONG WINDS GUSTS AND SMALL HAIL WITH THE STRONGEST STORMS (HIGHEST
THREAT AREA BASED ON CURRENT RADAR APPEARS TO CURRENTLY BE ACROSS
THE FAR NE PIEDMONT NEAR THE NC/VA BORDER AND THE FAR NORTHERN
COASTAL PLAIN)... WITH A VERY SMALL/WANING POTENTIAL OF AN ISOLATED
SEVERE STORM. THE LATEST HRRR SHOWS THE SHOWERS AND STORMS GENERALLY
ENDING ACROSS OUR AREA BY AROUND 05/06Z OR SO... WITH GENERALLY
ISOLATED TO SCATTERED COVERAGE ACROSS THE AFOREMENTIONED AREAS
THROUGH THEN. WILL CONTINUE TO GO WITH CHANCE POPS ACROSS THE FAR
NORTH WITH SLIGHT CHANCE POPS FOR SHOWERS AND STORMS AS FAR SOUTH AS
U.S. HIGHWAY 64... THROUGH 06/07Z. THUS... STILL THINK GIVEN THE
LACK OF APPRECIABLE UPPER FORCING AND STABILIZING BOUNDARY LAYER
THAT WE WILL SEE THE SHOWERS AND STORMS COME TO AN END BY THEN.
THE ACTUAL FRONT DOES NOT START TO PUSH SOUTHWARD THROUGH THE AREA
UNTIL AROUND 12Z THURSDAY... WHICH IS CURRENTLY EXTENDS FROM PORTION
OF SOUTHERN PA WSW`WARD INTO WV AND NORTHERN KY. THUS... WILL
CONTINUE TO GO WITH MILD OVERNIGHT LOWS RANGING FROM 56-60 DEGREES.
THURSDAY...SURFACE COLD FRONT WILL DRIFT SWD ACROSS THE SOUTHERN
COUNTIES EARLY THU MORNING. WHILE MOISTURE THROUGH THE COLUMN
ADEQUATE TO SUPPORT A FEW SHOWERS...FORCING WEAK OR NON-EXISTENT.
THUS ASIDE FROM SOME CLOUDINESS AND THE SURFACE WINDS SHIFTING TO
THE NW...FRONTAL PASSAGE WILL GO THROUGH VIRTUALLY UNEVENTFUL.
SUBSIDENCE BEHIND THE EXITING TROUGH WILL AID TO QUICKLY DIMINISH
CLOUD COVERAGE WITH MOSTLY SUNNY SKIES EXPECTED ALL LOCALES BY LATE
MORNING. WHILE 850MB NW...TEMP ADVECTION NEUTRAL OR SLIGHT CAA.
SINCE FLOW HAS DEFINITIVE DOWNSLOPE COMPONENT...ANY CAA WILL BE
OFFSET BY THE COMPRESSIONAL WARMING. MOS GUIDANCE IN THE 80-85
DEGREE RANGE APPEARS A TOUCH OVERDONE...SO FAVOR MAX TEMPS IN THE
UPPER 70S FAR NORTH TO LOWER 80S SOUTH.
THURSDAY NIGHT...HIGH PRESSURE CENTERED OVER ONTARIO WILL NOSE SWD
INTO CENTRAL NC. THIS WEATHER FEATURE SHOULD PROVIDE US WITH CLEAR
SKIES AND LIGHT NE FLOW. THIS WILL LEAD TO COOLER TEMPS WITH MIN
TEMPS MID 40S NE TO LOW/MID 50S FAR SOUTH.
ON FRIDAY WE`LL SEE THE HIGH PRESSURE TO OUR NORTH MOVE OFFSHORE AND
THE OLD COLD FRONT TO OUR SOUTH BEGIN TO LIFT NORTH AS A WARM FRONT
IN ADVANCE OF THE NEXT SHORT WAVE TO OUR WEST CROSSING THE OHIO
RIVER VALLEY. AFTER A MAINLY CLEAR START TO THE DAY...EXPECT TO SEE
INCREASING CLOUDINESS LATER IN THE DAY AND WARMING TEMPS WITH
SOUTHWEST LOW LEVEL FLOW INCREASING. AFTER A COOL START FRIDAY
MORNING...SOUNDINGS SUGGEST TEMPS WILL MODERATE TO NEAR NORMAL
VALUES IN THE AFTERNOON...GENERALLY UPPER 70S TO AROUND 80.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 325 AM...
A SHORT WAVE IS FORECAST TO BE APPROACHING THE MID ATLANTIC STATES
SATURDAY WITH A SURFACE LOW IN THE VICINITY OF DELAWARE. WITH
NORTHWEST FLOW ALOFT... THERE WOULD BE LIMITED POTENTIAL FOR RAIN...
CONFINED TO THE EAST DURING THE MORNING... WITH THE SURFACE LOW
EXITING INTO THE ATLANTIC EARLY IN THE DAY. UPPER LEVEL RIDGING
APPROACHED THE AREA FROM THE WEST. HIGH TEMPERATURES 80 TO 84
SATURDAY... UPPER 70S TO LOWER 80S SUNDAY. LOW TEMPERATURES IN THE
MID TO UPPER 50S.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 325 AM...
MAJORITY OF OPERATIONAL MODELS CLOSING OFF AN UPPER LOW IN THE
SOUTHERN ROCKIES OR PLAINS MONDAY WITH THE ECMWF CONTINUING WITH AN
OPEN WAVE. REGARDLESS THE MORE RAPID ADVANCE OF THE GFS IS DISCARDED
WITH THE EAST COAST RIDGE MUCH MORE PERSISTENT ON MOST MODELS. HAVE
DELAYED ANY SIGNIFICANT RAIN CHANCES (SLIGHT) UNTIL TUESDAY
AFTERNOON... ALTHOUGH THE UKMET AND CANADIAN SUGGEST EVEN THIS IS
TOO AGGRESSIVE. SHOULD THE TROUGH OR WAVE MOVE THROUGH CENTRAL NORTH
CAROLINA TUESDAY NIGHT... CLEARING SKIES AND COOLER TEMPERATURES
WOULD BE EXPECTED. THIS WOULD BE PERSISTENT WITH CURRENT FORECAST
AND HPC GUIDANCE AND ACCEPTED WITH LOW CONFIDENCE.
EXPECT HIGH TEMPERATURES IN THE MID 80S UNDER THE UPPER RIDGE WITH
UPPER 70S TO LOWER 80S TUESDAY WITH MORE CLOUDINESS AND MOISTURE.
ASSUMING THE SURFACE TROUGH PASSES THROUGH TUESDAY... HIGHS FALL TO
THE LOW TO MID 70S. LOW TEMPERATURES MID TO UPPER 50S UNTIL TUESDAY
NIGHT... WHEN SUNRISE TEMPERATURES WEDNESDAY SLIP TO 50 TO 55.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AS OF 225 AM THURSDAY...
IT APPEARS THAT A BAND OF SHOWERS AND EVEN AN ISOLATED THUNDERSTORM
-- AND AN ASSOCIATED GUSTY WNW WIND AND VERY BRIEF MVFR CEILING/
VISIBILITY -- OVER SW VA AND NW NC AT 06Z WILL HOLD TOGETHER AND
THREATEN KGSO/KINT THROUGH ABOUT 08Z. OVERALL...THIS ACTIVITY IS
EXPECTED TO GRADUALLY DISSIPATE AS IT MOVES SOUTHEASTWARD INTO
CENTRAL NC...BUT CURRENT INDICATIONS ARE THAT IT MAY HOLD TOGETHER
TO AFFECT KRDU BETWEEN 07-08Z. OTHERWISE...VFR CONDITIONS WILL HOLD
THROUGH THE 06Z TAF PERIOD. A SOUTHWEST BREEZE WILL GRADUALLY VEER
TO NORTHWEST AND LESSEN THROUGH DAYBREAK...THEN INCREASE INTO THE
9-13 KT RANGE WITH OCCASIONAL GUSTINESS INTO THE MID-UPPER TEENS KTS
FROM MIDDAY THROUGH THIS AFTERNOON. WINDS WILL THEN BECOME LIGHT
NORTH TO NORTHEASTERLY AFTER 00Z...AS A DRY COLD FRONT SETTLES
SOUTHWARD INTO SC.
OUTLOOK:
A PERIOD OF MVFR CEILINGS...MAINLY AT KRDU AND KRWI...WILL BE
POSSIBLE LATE-MORNING THROUGH THE AFTERNOON FRI...AS THE
AFOREMENTIONED SURFACE FRONT RETURNS NORTHWARD AS A WARM FRONT
DURING THE DAY. THE PASSAGE OF THE BOUNDARY AND RESULTANT INCREASING
LIFT AND HUMIDITY WILL ALSO PROMOTE THE DEVELOPMENT OF SCATTERED
AFTERNOON THUNDERSTORMS MAINLY AT KRDU/KRWI/KFAY...FOLLOWED BY A LOW
CHANCE OF STRATUS...AND A CONTINUED THREAT OF A SHOWER OR STORM...
FRI NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...WSS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
228 AM EDT THU MAR 29 2012
.SYNOPSIS...
A DRY COLD FRONT WILL CROSS NC TODAY AND SETTLE INTO SC TONIGHT. THE
FRONT WILL RETURN NORTHWARD AS A WARM FRONT ON FRIDAY...IN ADVANCE
OF A LOW PRESSURE SYSTEM AND TRAILING COLD FRONT THAT WILL CROSS THE
MIDDLE ATLANTIC STATES FRIDAY NIGHT THROUGH SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 PM EDT WEDNESDAY...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH AN APPROACHING COLD FRONT
HAVE REMAINED GENERALLY TO THE NORTH OF THE AREA THIS EVENING.
HOWEVER... THE LATEST HI-RES MODELS CONTINUE TO INDICATE SOME OF
THIS ACTIVITY MOVING INTO/DEVELOPING ACROSS OUR NORTHERN PIEDMONT
AND NORTHERN COASTAL PLAIN COUNTIES AS RAIN COOLED OUTFLOW FROM
CURRENT ACTIVITY ACROSS SOUTHERN VA HELPS TO OVERCOME THE NEAR
SURFACE STABLE LAYER. THIS ACTIVITY HAS DECREASED IN COVERAGE OVER
THE LAST SEVERAL HOURS THOUGH... THANKS IN PART TO A STABILIZING
BOUNDARY LAYER AND LACK OF ANY SIGNIFICANT UPPER DYNAMICS.
HOWEVER... GIVEN WESTERLY DEEP LAYER SHEAR OF AROUND 30 TO 40 KTS
AND STEEP MID LEVEL LAPSE RATES OF AROUND 7.5-8 DEGREES C/KM (WHICH
IS ALSO HELPING TO KEEP THE STORMS GOING) EXPECT WE COULD SEE SOME
STRONG WINDS GUSTS AND SMALL HAIL WITH THE STRONGEST STORMS (HIGHEST
THREAT AREA BASED ON CURRENT RADAR APPEARS TO CURRENTLY BE ACROSS
THE FAR NE PIEDMONT NEAR THE NC/VA BORDER AND THE FAR NORTHERN
COASTAL PLAIN)... WITH A VERY SMALL/WANING POTENTIAL OF AN ISOLATED
SEVERE STORM. THE LATEST HRRR SHOWS THE SHOWERS AND STORMS GENERALLY
ENDING ACROSS OUR AREA BY AROUND 05/06Z OR SO... WITH GENERALLY
ISOLATED TO SCATTERED COVERAGE ACROSS THE AFOREMENTIONED AREAS
THROUGH THEN. WILL CONTINUE TO GO WITH CHANCE POPS ACROSS THE FAR
NORTH WITH SLIGHT CHANCE POPS FOR SHOWERS AND STORMS AS FAR SOUTH AS
U.S. HIGHWAY 64... THROUGH 06/07Z. THUS... STILL THINK GIVEN THE
LACK OF APPRECIABLE UPPER FORCING AND STABILIZING BOUNDARY LAYER
THAT WE WILL SEE THE SHOWERS AND STORMS COME TO AN END BY THEN.
THE ACTUAL FRONT DOES NOT START TO PUSH SOUTHWARD THROUGH THE AREA
UNTIL AROUND 12Z THURSDAY... WHICH IS CURRENTLY EXTENDS FROM PORTION
OF SOUTHERN PA WSW`WARD INTO WV AND NORTHERN KY. THUS... WILL
CONTINUE TO GO WITH MILD OVERNIGHT LOWS RANGING FROM 56-60 DEGREES.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 305 PM WEDNESDAY...
THURSDAY...SURFACE COLD FRONT WILL DRIFT SWD ACROSS THE SOUTHERN
COUNTIES EARLY THU MORNING. WHILE MOISTURE THROUGH THE COLUMN
ADEQUATE TO SUPPORT A FEW SHOWERS...FORCING WEAK OR NON-EXISTENT.
THUS ASIDE FROM SOME CLOUDINESS AND THE SURFACE WINDS SHIFTING TO
THE NW...FRONTAL PASSAGE WILL GO THROUGH VIRTUALLY UNEVENTFUL.
SUBSIDENCE BEHIND THE EXITING TROUGH WILL AID TO QUICKLY DIMINISH
CLOUD COVERAGE WITH MOSTLY SUNNY SKIES EXPECTED ALL LOCALES BY LATE
MORNING. WHILE 850MB NW...TEMP ADVECTION NEUTRAL OR SLIGHT CAA.
SINCE FLOW HAS DEFINITIVE DOWNSLOPE COMPONENT...ANY CAA WILL BE
OFFSET BY THE COMPRESSIONAL WARMING. MOS GUIDANCE IN THE 80-85
DEGREE RANGE APPEARS A TOUCH OVERDONE...SO FAVOR MAX TEMPS IN THE
UPPER 70S FAR NORTH TO LOWER 80S SOUTH.
THURSDAY NIGHT...HIGH PRESSURE CENTERED OVER ONTARIO WILL NOSE SWD
INTO CENTRAL NC. THIS WEATHER FEATURE SHOULD PROVIDE US WITH CLEAR
SKIES AND LIGHT NE FLOW. THIS WILL LEAD TO COOLER TEMPS WITH MIN
TEMPS MID 40S NE TO LOW/MID 50S FAR SOUTH.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM WEDNESDAY...
ON FRIDAY WE`LL SEE THE HIGH PRESSURE TO OUR NORTH MOVE OFFSHORE AND
THE OLD COLD FRONT TO OUR SOUTH BEGIN TO LIFT NORTH AS A WARM FRONT
IN ADVANCE OF THE NEXT SHORT WAVE TO OUR WEST CROSSING THE OHIO
RIVER VALLEY. AFTER A MAINLY CLEAR START TO THE DAY...EXPECT TO SEE
INCREASING CLOUDINESS LATER IN THE DAY AND WARMING TEMPS WITH
SOUTHWEST LOW LEVEL FLOW INCREASING. AFTER A COOL START FRIDAY
MORNING...SOUNDINGS SUGGEST TEMPS WILL MODERATE TO NEAR NORMAL
VALUES IN THE AFTERNOON...GENERALLY UPPER 70S TO AROUND 80.
WE CONTINUE TO SEE SIGNIFICANT DIFFERENCES IN MODEL SOLUTIONS
BEGINNING FRIDAY NIGHT. THE LATEST GFS AND MOST OTHER MODELS ARE
PROGRESSIVE WITH THE AFOREMENTIONED SHORT WAVE THAT WILL BE CROSSING
THE OHIO RIVER VALLEY DURING THE DAYTIME FRIDAY...AND MOVE IT AND
ITS ATTENDANT SFC COLD FRONT ACROSS OUR AREA LATE ON SATURDAY
FOLLOWED BY HIGH PRESSURE BUILDING ACROSS THE AREA FROM THE NORTH
SATURDAY NIGHT AND SUNDAY. MEANWHILE...THE 0Z ECMWF CONTINUES TO
INDICATE A MUCH DIFFERENT SOLUTION THAT BASICALLY SLOWS THE
SHORTWAVE AND DELAYS THE FRONTAL PASSAGE UNTIL SUNDAY. THE GFS AND
OTHER PROGRESSIVE MODELS BASICALLY RESULT IN LOWER-IMPACT SHOWERS
AND TSTMS LATE FRIDAY AND SATURDAY FOLLOWED BY FAIR WEATHER ON
SUNDAY...WHILE THE 0Z ECMWF WOULD SUGGEST POTENTIALLY HIGHER-IMPACT
THUNDERSTORMS DURING THE DAYTIME SATURDAY AND POSSIBLY AGAIN ON
SUNDAY WITH THE FRONTAL PASSAGE. GIVEN THE LOWER-THAN-USUAL
CONFIDENCE...FOR NOW WILL MAKE FEW CHANGES TO CURRENT FORECAST...
WHICH SHOWS RAIN CHANCES INCREASING FRIDAY NIGHT AND CONTINUING INTO
SATURDAY NIGHT THEN DIMINISHING POPS ON SUNDAY. WORTH REPEATING THAT
IF THE TREND GOES TOWARD THE 0Z ECMWF...THE RISK FOR AN ACTIVE
THUNDERSTORM DAY ON SATURDAY INCREASES. TEMPS DURING THE WEEKEND
WILL BE HIGHLY DEPENDENT ON THE EVOLUTION OF THE PRECIP AND FRONTAL
TIMING. FOR NOW WILL CONTINUE ABOVE NORMAL TEMPS SATURDAY IN THE
PREFRONTAL ENVIRONMENT...THEN COOLER ON SUNDAY WITH EITHER THE FRONT
TO OUR SOUTH (GFS)...OR DUE TO PRECIP (ECMWF) KEEPING TEMPS DOWN.
MODELS COME INTO BETTER AGREEMENT EARLY NEXT WEEK...AND INDICATE A
RIDGE ACROSS OUR REGION ON MONDAY YIELDING FAIR WEATHER WITH TEMPS
10+ DEGREES ABOVE NORMAL...FOLLOWED BY A HIGHLY AMPLIFIED TROUGH
AFFECTING THE EASTERN PORTION OF THE COUNTRY DURING THE MIDDLE OF
THE WEEK. THIS TROUGH WILL PUSH A SFC COLD FRONT ACROSS OUR AREA ON
TUESDAY AND WILL START A MUCH COOLER TREND THAT WILL LINGER THROUGH
THE MIDDLE TO LATTER PART OF THE WEEK. EXPECT A CHANCE FOR SHOWERS
AND THUNDERSTORMS ALONG AND AHEAD OF TUESDAYS COLD FRONT...OTHERWISE
MUCH OF NEXT WEEK SHOULD BE DRY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 225 AM THURSDAY...
IT APPEARS THAT A BAND OF SHOWERS AND EVEN AN ISOLATED THUNDERSTORM
-- AND AN ASSOCIATED GUSTY WNW WIND AND VERY BRIEF MVFR CEILING/
VISIBILITY -- OVER SW VA AND NW NC AT 06Z WILL HOLD TOGETHER AND
THREATEN KGSO/KINT THROUGH ABOUT 08Z. OVERALL...THIS ACTIVITY IS
EXPECTED TO GRADUALLY DISSIPATE AS IT MOVES SOUTHEASTWARD INTO
CENTRAL NC...BUT CURRENT INDICATIONS ARE THAT IT MAY HOLD TOGETHER
TO AFFECT KRDU BETWEEN 07-08Z. OTHERWISE...VFR CONDITIONS WILL HOLD
THROUGH THE 06Z TAF PERIOD. A SOUTHWEST BREEZE WILL GRADUALLY VEER
TO NORTHWEST AND LESSEN THROUGH DAYBREAK...THEN INCREASE INTO THE
9-13 KT RANGE WITH OCCASIONAL GUSTINESS INTO THE MID-UPPER TEENS KTS
FROM MIDDAY THROUGH THIS AFTERNOON. WINDS WILL THEN BECOME LIGHT
NORTH TO NORTHEASTERLY AFTER 00Z...AS A DRY COLD FRONT SETTLES
SOUTHWARD INTO SC.
OUTLOOK:
A PERIOD OF MVFR CEILINGS...MAINLY AT KRDU AND KRWI...WILL BE
POSSIBLE LATE-MORNING THROUGH THE AFTERNOON FRI...AS THE
AFOREMENTIONED SURFACE FRONT RETURNS NORTHWARD AS A WARM FRONT
DURING THE DAY. THE PASSAGE OF THE BOUNDARY AND RESULTANT INCREASING
LIFT AND HUMIDITY WILL ALSO PROMOTE THE DEVELOPMENT OF SCATTERED
AFTERNOON THUNDERSTORMS MAINLY AT KRDU/KRWI/KFAY...FOLLOWED BY A LOW
CHANCE OF STRATUS...AND A CONTINUED THREAT OF A SHOWER OR STORM...
FRI NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...NP
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
128 AM EDT THU MAR 29 2012
.SYNOPSIS...
A DRY COLD FRONT WILL CROSS NC TODAY AND SETTLE INTO SC TONIGHT. THE
FRONT WILL RETURN NORTHWARD AS A WARM FRONT ON FRIDAY...IN ADVANCE
OF A LOW PRESSURE SYSTEM AND TRAILING COLD FRONT THAT WILL CROSS THE
MIDDLE ATLANTIC STATES FRIDAY NIGHT THROUGH SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 PM EDT WEDNESDAY...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH AN APPROACHING COLD FRONT
HAVE REMAINED GENERALLY TO THE NORTH OF THE AREA THIS EVENING.
HOWEVER... THE LATEST HI-RES MODELS CONTINUE TO INDICATE SOME OF
THIS ACTIVITY MOVING INTO/DEVELOPING ACROSS OUR NORTHERN PIEDMONT
AND NORTHERN COASTAL PLAIN COUNTIES AS RAIN COOLED OUTFLOW FROM
CURRENT ACTIVITY ACROSS SOUTHERN VA HELPS TO OVERCOME THE NEAR
SURFACE STABLE LAYER. THIS ACTIVITY HAS DECREASED IN COVERAGE OVER
THE LAST SEVERAL HOURS THOUGH... THANKS IN PART TO A STABILIZING
BOUNDARY LAYER AND LACK OF ANY SIGNIFICANT UPPER DYNAMICS.
HOWEVER... GIVEN WESTERLY DEEP LAYER SHEAR OF AROUND 30 TO 40 KTS
AND STEEP MID LEVEL LAPSE RATES OF AROUND 7.5-8 DEGREES C/KM (WHICH
IS ALSO HELPING TO KEEP THE STORMS GOING) EXPECT WE COULD SEE SOME
STRONG WINDS GUSTS AND SMALL HAIL WITH THE STRONGEST STORMS (HIGHEST
THREAT AREA BASED ON CURRENT RADAR APPEARS TO CURRENTLY BE ACROSS
THE FAR NE PIEDMONT NEAR THE NC/VA BORDER AND THE FAR NORTHERN
COASTAL PLAIN)... WITH A VERY SMALL/WANING POTENTIAL OF AN ISOLATED
SEVERE STORM. THE LATEST HRRR SHOWS THE SHOWERS AND STORMS GENERALLY
ENDING ACROSS OUR AREA BY AROUND 05/06Z OR SO... WITH GENERALLY
ISOLATED TO SCATTERED COVERAGE ACROSS THE AFOREMENTIONED AREAS
THROUGH THEN. WILL CONTINUE TO GO WITH CHANCE POPS ACROSS THE FAR
NORTH WITH SLIGHT CHANCE POPS FOR SHOWERS AND STORMS AS FAR SOUTH AS
U.S. HIGHWAY 64... THROUGH 06/07Z. THUS... STILL THINK GIVEN THE
LACK OF APPRECIABLE UPPER FORCING AND STABILIZING BOUNDARY LAYER
THAT WE WILL SEE THE SHOWERS AND STORMS COME TO AN END BY THEN.
THE ACTUAL FRONT DOES NOT START TO PUSH SOUTHWARD THROUGH THE AREA
UNTIL AROUND 12Z THURSDAY... WHICH IS CURRENTLY EXTENDS FROM PORTION
OF SOUTHERN PA WSW`WARD INTO WV AND NORTHERN KY. THUS... WILL
CONTINUE TO GO WITH MILD OVERNIGHT LOWS RANGING FROM 56-60 DEGREES.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 305 PM WEDNESDAY...
THURSDAY...SURFACE COLD FRONT WILL DRIFT SWD ACROSS THE SOUTHERN
COUNTIES EARLY THU MORNING. WHILE MOISTURE THROUGH THE COLUMN
ADEQUATE TO SUPPORT A FEW SHOWERS...FORCING WEAK OR NON-EXISTENT.
THUS ASIDE FROM SOME CLOUDINESS AND THE SURFACE WINDS SHIFTING TO
THE NW...FRONTAL PASSAGE WILL GO THROUGH VIRTUALLY UNEVENTFUL.
SUBSIDENCE BEHIND THE EXITING TROUGH WILL AID TO QUICKLY DIMINISH
CLOUD COVERAGE WITH MOSTLY SUNNY SKIES EXPECTED ALL LOCALES BY LATE
MORNING. WHILE 850MB NW...TEMP ADVECTION NEUTRAL OR SLIGHT CAA.
SINCE FLOW HAS DEFINITIVE DOWNSLOPE COMPONENT...ANY CAA WILL BE
OFFSET BY THE COMPRESSIONAL WARMING. MOS GUIDANCE IN THE 80-85
DEGREE RANGE APPEARS A TOUCH OVERDONE...SO FAVOR MAX TEMPS IN THE
UPPER 70S FAR NORTH TO LOWER 80S SOUTH.
THURSDAY NIGHT...HIGH PRESSURE CENTERED OVER ONTARIO WILL NOSE SWD
INTO CENTRAL NC. THIS WEATHER FEATURE SHOULD PROVIDE US WITH CLEAR
SKIES AND LIGHT NE FLOW. THIS WILL LEAD TO COOLER TEMPS WITH MIN
TEMPS MID 40S NE TO LOW/MID 50S FAR SOUTH.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM WEDNESDAY...
ON FRIDAY WE`LL SEE THE HIGH PRESSURE TO OUR NORTH MOVE OFFSHORE AND
THE OLD COLD FRONT TO OUR SOUTH BEGIN TO LIFT NORTH AS A WARM FRONT
IN ADVANCE OF THE NEXT SHORT WAVE TO OUR WEST CROSSING THE OHIO
RIVER VALLEY. AFTER A MAINLY CLEAR START TO THE DAY...EXPECT TO SEE
INCREASING CLOUDINESS LATER IN THE DAY AND WARMING TEMPS WITH
SOUTHWEST LOW LEVEL FLOW INCREASING. AFTER A COOL START FRIDAY
MORNING...SOUNDINGS SUGGEST TEMPS WILL MODERATE TO NEAR NORMAL
VALUES IN THE AFTERNOON...GENERALLY UPPER 70S TO AROUND 80.
WE CONTINUE TO SEE SIGNIFICANT DIFFERENCES IN MODEL SOLUTIONS
BEGINNING FRIDAY NIGHT. THE LATEST GFS AND MOST OTHER MODELS ARE
PROGRESSIVE WITH THE AFOREMENTIONED SHORT WAVE THAT WILL BE CROSSING
THE OHIO RIVER VALLEY DURING THE DAYTIME FRIDAY...AND MOVE IT AND
ITS ATTENDANT SFC COLD FRONT ACROSS OUR AREA LATE ON SATURDAY
FOLLOWED BY HIGH PRESSURE BUILDING ACROSS THE AREA FROM THE NORTH
SATURDAY NIGHT AND SUNDAY. MEANWHILE...THE 0Z ECMWF CONTINUES TO
INDICATE A MUCH DIFFERENT SOLUTION THAT BASICALLY SLOWS THE
SHORTWAVE AND DELAYS THE FRONTAL PASSAGE UNTIL SUNDAY. THE GFS AND
OTHER PROGRESSIVE MODELS BASICALLY RESULT IN LOWER-IMPACT SHOWERS
AND TSTMS LATE FRIDAY AND SATURDAY FOLLOWED BY FAIR WEATHER ON
SUNDAY...WHILE THE 0Z ECMWF WOULD SUGGEST POTENTIALLY HIGHER-IMPACT
THUNDERSTORMS DURING THE DAYTIME SATURDAY AND POSSIBLY AGAIN ON
SUNDAY WITH THE FRONTAL PASSAGE. GIVEN THE LOWER-THAN-USUAL
CONFIDENCE...FOR NOW WILL MAKE FEW CHANGES TO CURRENT FORECAST...
WHICH SHOWS RAIN CHANCES INCREASING FRIDAY NIGHT AND CONTINUING INTO
SATURDAY NIGHT THEN DIMINISHING POPS ON SUNDAY. WORTH REPEATING THAT
IF THE TREND GOES TOWARD THE 0Z ECMWF...THE RISK FOR AN ACTIVE
THUNDERSTORM DAY ON SATURDAY INCREASES. TEMPS DURING THE WEEKEND
WILL BE HIGHLY DEPENDENT ON THE EVOLUTION OF THE PRECIP AND FRONTAL
TIMING. FOR NOW WILL CONTINUE ABOVE NORMAL TEMPS SATURDAY IN THE
PREFRONTAL ENVIRONMENT...THEN COOLER ON SUNDAY WITH EITHER THE FRONT
TO OUR SOUTH (GFS)...OR DUE TO PRECIP (ECMWF) KEEPING TEMPS DOWN.
MODELS COME INTO BETTER AGREEMENT EARLY NEXT WEEK...AND INDICATE A
RIDGE ACROSS OUR REGION ON MONDAY YIELDING FAIR WEATHER WITH TEMPS
10+ DEGREES ABOVE NORMAL...FOLLOWED BY A HIGHLY AMPLIFIED TROUGH
AFFECTING THE EASTERN PORTION OF THE COUNTRY DURING THE MIDDLE OF
THE WEEK. THIS TROUGH WILL PUSH A SFC COLD FRONT ACROSS OUR AREA ON
TUESDAY AND WILL START A MUCH COOLER TREND THAT WILL LINGER THROUGH
THE MIDDLE TO LATTER PART OF THE WEEK. EXPECT A CHANCE FOR SHOWERS
AND THUNDERSTORMS ALONG AND AHEAD OF TUESDAYS COLD FRONT...OTHERWISE
MUCH OF NEXT WEEK SHOULD BE DRY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 125 AM THURSDAY...
IT APPEARS THAT A BAND OF SHOWERS AND EVEN AN ISOLATED THUNDERSTORM
-- AND AN ASSOCIATED GUSTY WNW WIND AND VERY BRIEF MVFR CEILING/
VISIBILITY -- OVER SW VA AND NW NC AT 06Z WILL HOLD TOGETHER AND
THREATEN KGSO/KINT THROUGH ABOUT 08Z. OVERALL...THIS ACTIVITY IS
EXPECTED TO GRADUALLY DISSIPATE AS IT MOVES SOUTHEASTWARD INTO
CENTRAL NC...BUT CURRENT INDICATIONS ARE THAT IT MAY HOLD TOGETHER
TO AFFECT KRDU BETWEEN 07-08Z. OTHERWISE...VFR CONDITIONS WILL HOLD
THROUGH THE 06Z TAF PERIOD. A SOUTHWEST BREEZE WILL GRADUALLY VEER
TO NORTHWEST AND LESSEN THROUGH DAYBREAK...THEN INCREASE INTO THE
9-13 KT RANGE WITH OCCASIONAL GUSTINESS INTO THE MID-UPPER TEENS KTS
FROM MIDDAY THROUGH THIS AFTERNOON. WINDS WILL THEN BECOME LIGHT
NORTH TO NORTHEASTERLY AFTER 00Z...AS A DRY COLD FRONT SETTLES
SOUTHWARD INTO SC.
OUTLOOK:
A PERIOD OF MVFR CEILINGS...MAINLY AT KRDU AND KRWI...WILL BE
POSSIBLE LATE-MORNING THROUGH THE AFTERNOON FRI...AS THE
AFOREMENTIONED SURFACE FRONT RETURNS NORTHWARD AS A WARM FRONT
DURING THE DAY. THE PASSAGE OF THE BOUNDARY AND RESULTANT INCREASING
LIFT AND HUMIDITY WILL ALSO PROMOTE THE DEVELOPMENT OF SCATTERED
AFTERNOON THUNDERSTORMS MAINLY AT KRDU/KRWI/KFAY...FOLLOWED BY A LOW
CHANCE OF STRATUS...AND A CONTINUED THREAT OF A SHOWER OR STORM...
FRI NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...NP
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
526 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE PASSES TO THE NORTH LATE TODAY. LOW PRESSURE BRINGS
A WARM FRONT...THEN A COLD FRONT FRIDAY...THE LATTER WITH MORE
STORMS LATE FRIDAY. HIGH PRESSURE CROSSES SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST IR IMAGERY HAS CLEAR SKY FOR ENTIRE CWA CURRENTLY.
HOWEVER...LOW LEVEL MOISTURE ASSOCIATED WITH THE POST-FRONTAL TROF
TO OUR NORTH IS OOZING SOUTHWARD AND SHOULD BEGIN TO POOL UP AGAINST
THE NRN WV MOUNTAINS EVENTUALLY DEVELOPING OROGRAPHICALLY INDUCED
CLOUDS AND NOTHING MORE.
CURRENT WV IMAGERY SHOWING COPIOUS DRY AIR DIRECTLY OVER OUR
AREA...AND THIS IS HANDLED WELL IN THE RUC H5-H7 LAYER.
THIS...COMBINED WITH MORNING DAYTIME HEATING...SHOULD WORK TO
QUICKLY DISSIPATE THE LOW LEVEL CLOUDS THAT ARE CONTINUING TO
DEVELOP IN THE NRN WV MNTS CURRENTLY. OVERALL...A PLEASANT DAY IS ON
TAP WITH CLEAR SKY CONDITIONS AND TEMPERATURES RETURNING A LITTLE
CLOSER TO SEASONAL AVERAGE.
CLEAR SKY AND MODEST CAA EARLY TONIGHT WILL WORK TO BRING
TEMPERATURES DOWN IN THE NRN ZONES NEARING THE POINT OF FROST
DEVELOPMENT. AT THE SAME TIME...NEAR TERM MODELS HAVE BEEN SPEEDING
UP THE TIMING OF THE APPROACH OF THE NEXT WARM FRONT. 06Z NAM AND
03Z SREF MEAN HAS THETA-E GRADIENT EAST OF THE TUG FORK VALLEY AND
THE TRI-STATE AREA BY 12Z FRI. WITH THIS IN MIND...WILL NOT BE
ISSUING FROST ADVY FOR NRN ZONES WITH THIS ISSUANCE...BUT WILL
MENTION POSSIBILITY FOR PATCHY FROST IN WX GRIDS AND ZONES.
FOR REASONS MENTIONED ABOVE...HAVE SPED UP TIMING OF THE ONSET OF
CLOUD COVER AND POPS ASSOCIATED WITH WARM FRONT TOWARDS THE END OF
THE NEAR TERM. BY MID-DAY FRI...CWA SHOULD BE FIRMLY PLANTED IN THE
WARM SECTOR WITH TEMPS REBOUNDING QUICKLY.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
SHIFTED SAT SYSTEM TO FRI YESTERDAY...RESULTING IN AN ENTIRELY DRY
WEEKEND. NOW IT LOOKS LIKE WE MAY BE TAKING BACK SUNDAY.
FRI SYSTEM REMAINS ON TRACK AS EVEN ECMWF HAS COME AROUND TO THE
FASTER TIMING. NW-SE ORIENTED WARM FRONT...THEN THE WARM
SECTOR...THEN NE-SW ORIENTED COLD FRONT MARCH ACROSS IN A NICE
CLASSICAL SYNOPTIC SETUP. WORRIED PRECIPITATION COULD BREAK OUT
ALONG THE WARM FRONT FRI MORNING...WHICH IS MARKED BY WELL DEFINED
THETA E GRADIENT. WE COULD EVEN SEE A CONVECTIVE COMPLEX SIMILAR TO
WHAT IS GOING ON THIS MORNING OVER THE MIDWEST ALONG SAID GRADIENT.
AFTER A BREAK IN THE WARM SECTOR EARLY FRI AFTERNOON...SHOWERS AND
STRONG THUNDERSTORMS FIRE UP AHEAD OF THE COLD FRONT LATE FRI
AFTERNOON AND TRAVERSE THE AREA FROM NW TO SE THROUGH FRI EVENING.
THE THERMODYNAMIC AND KINEMATIC PARAMETERS LOOK SIMILAR TO THOSE
AHEAD OF THE COLD FRONT THAT TRAVERSED THE AREA LAST NIGHT...SO A
SIMILAR HAIL AND WIND THREAT IS ANTICIPATED. INSTABILITY LOOKS TO
BE GREATEST AS ONE MOVES SW ALONG FRONT...CLOSE TO MOISTURE SOURCE.
INDEED...SPC CONTINUES TO PEG WESTERN PORTIONS OF THE AREA FOR THE
SLIGHT RISK.
WILL KEEP HWO HAZARD AND RWS IMPACT FOR SEVERE THUNDERSTORMS
EMPHASIZING THE W.
COLD ADVECTION IN THE WAKE OF THE SYSTEM SAT WILL BE ACCOMPANIED BY
DEEPER MOISTURE COMPARED WITH TODAY...ALONG WITH SOME SUB FREEZING
LOW LEVEL TEMPERATURES...SO OPTED TO LEAVE SHOWER CHANCE IN THE
MOUNTAINS. ALSO LOTS OF STRATOCU ATOP MIXED LAYER THROUGHOUT THE
AREA.
THE CONUNDRUM SUNDAY IS A NW FLOW WARM ADVECTION FEATURE THAT MAY
AGAIN MATERIALIZE AS A CONVECTIVE COMPLEX. FOR NOW...JUST ADDED THE
SLIGHT CHANCE FOR SHOWERS IN CONCERT WITH NEIGHBORS TO THE N AND W.
THANKS ILN AND PBZ FOR COORD ON THIS CHANGE. WOULD NOT BE SURPRISED
TO SEE THIS BLOW UP INTO SOMETHING MORE IF THE GENERAL PATTERN
EVOLUTION HOLDS.
USED A CACOPHONY OF GUIDANCE BLENDS TO ARRIVE AT TEMPERATURES.
TRIED TO RAISE HIGHS FRI IN THE WARM SECTOR...ESPECIALLY SOUTHERN
AND CENTRAL PORTIONS OF THE AREA. LOWERED A LITTLE FRI NT THROUGH
SAT NT ALTHOUGH NAM12 SUGGESTS IT WILL BE EVEN COLDER. TRENDED
TEMPERATURES UP JUST A BIT SUN AND SUN NT.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
STILL HAVE A DEGREE OF UNCERTAINTY TO THE EXTENDED...PER
USUAL...RESULTING IN A BLEND COMING FROM HPC IN THE FORECAST GRIDS.
DID ADJUST SOME OF THE SKIES DURING THE EXTENDED PERIOD TO BETTER
MATCH UP WITH THE POPS IN THE FORECAST. OVERALL...LOOKING AT MORE
SEASONAL TEMPERATURES...AND DESPITE A COUPLE OF SYSTEMS IN THE LONG
TERM MODELS...OVERALL PRECIPITATION TO COME IN ON THE LOWER SIDE. DO
HAVE A COUPLE OF NIGHTS TOWARDS THE END OF THE PERIOD WHERE WE MAY
NEED TO BE CAREFUL OF FROST AND FREEZE GIVEN THE TRENDS IN THAT TIME
PERIOD WITH A DEEP TROUGH LIFTING OUT AND THE SKY TRYING TO
CLEAR...BUT AS OF NOW...NOTHING TO BE MENTIONED IN THE HWO OR RWS.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
00Z THURSDAY THRU 00Z FRIDAY...
HIGH PRESSURE BUILDS IN THIS MORNING. GENERALLY VFR WITH MOSTLY
CLEAR CONDITIONS. SOME LOW LEVEL MOISTURE SNEAKS BACK IN LATE
TONIGHT AND THURSDAY IN THE NORTH AND EAST...BUT EXPECT VFR SCT-BKN
CLOUDS TO PREVAIL THERE THROUGH 00Z THURSDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: NONE
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 03/29/12
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z FRIDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/TAX
NEAR TERM...TAX
SHORT TERM...TRM
LONG TERM...26
AVIATION...TAX
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1110 PM CDT WED MAR 28 2012
.DISCUSSION.../ISSUED AT 920 PM CDT/
SEEING SOME LIGHT SHOWERS SHOWING UP ON RADAR ACROSS EASTERN
NEBRASKA AND PORTIONS OF IOWA ASSOCIATED WITH AN AREA OF THETAE
ADVECTION ON THE NOSE OF AN INCREASING LOW LEVEL JET. THIS AREA WILL
CONTINUE TO MOVE NORTH...REACHING SIOUX CITY BY 6Z AND SIOUX FALLS
BY 9Z. TOUGH TO SAY WHETHER WE GET MUCH OUT OF THIS THROUGH 12Z.
BEST CHANCE OF SEEING A SHOWER WILL BE RIGHT ALONG THE ELEVATED
INSTABILITY BOUNDARY....WHICH ACCORDING TO THE NAM WILL RUN FROM
SIOUX CITY NORTHWEST THROUGH SIOUX FALLS AND HURON. ELEVATED CAPE
ONLY EXPECTED TO BE A FEW HUNDRED J/KG. THUS NOT EXPECTING ANYTHING
SIGNIFICANT THROUGH 12Z...IN FACT WE MIGHT NOT EVEN BE ABLE TO GET
ANY THUNDER OUT OF THESE SHOWERS. FURTHER WEST...MUCAPE WILL BE
HIGHER...BUT THE COMBINATION OF LESS LOW LEVEL LIFT AND WARMER TEMPS
ALOFT ACTING AS A CAP...SHOULD PREVENT ANYTHING FROM FORMING THERE.
LATEST HRRR IS FURTHER SOUTHWEST WITH THE BEST LOW LEVEL MOISTURE
RETURN AND ELEVATED CAPE...AND KEEPS OUR ENTIRE CWA DRY THROUGH 12Z.
FOR NOW...DECIDED TO KEEP POPS IN THROUGH THE OVERNIGHT WITH THE
NAM...GFS AND SREF SHOWING SOME SPOTTY SHOWERS. /CHENARD
PREVIOUS DISCUSSION...
SURFACE RIDGE NOSING THROUGH MINNESOTA WILL BEGIN TO SLIP EAST WITH
AN INCREASING EAST TO SOUTHEAST FLOW ACROSS THE AREA. NOT MUCH FOR
IMMEDIATE MOISTURE RETURN...BUT 50S TO LOWER 60S DEWPOINTS ARE
GATHERING ACROSS KANSAS...WITH ELEVATED CONVECTION DEVELOPING ACROSS
SOUTHERN NEBRASKA. MORE SURFACE BASED CONVECTION IS EXPECTED TO
DEVELOP ALONG THE SURFACE TO 925 HPA MOISTURE DISCONTINUITY THIS
EVENING...AND THIS WILL LIKELY DISRUPT THE DEVELOPMENT OF THE LOW
LEVEL JET SOMEWHAT. HOWEVER...BY LATE NIGHT...SOME ELEVATED CAPES
FROM 800 HPA ON THE ORDER OF 400-600 J/KG WITH CAP WEAK ON ORDER OF
25 J/KG OR LESS...BUT DISTRIBUTED OVER ABOUT A 100 HPA DEEP LAYER...
SUGGESTING WILL NEED SOME APPRECIABLE FORCING TO GET ANY ELEVATED
ACTIVITY...WHICH WILL LIKELY WAIT UNTIL LOW LEVEL JET BECOMES
ESTABLISHED...ESPECIALLY TOWARD 12Z...AND USED THE GRADIENT IN
ELEVATED INSTABILITY TO DEFINE TIMING.
CONCERN IN PLACE THAT AFTER THE INITIAL ELEVATED PUSH DURING THE
EARLY TO MID MORNING HOURS...THAT MAY SEE A FAIRLY QUIET PERIOD FOR
MOST UNTIL STRONGER DYNAMIC FORCING ASSOCIATED WITH MID LEVEL WAVE
FROM THE WEST DURING THE AFTERNOON. SOME DISTRIBUTION OF
PRECIPITATION ISSUES WILL DEPEND ON DESTABILIZATION/BOUNDARY
LOCATIONS FROM MORNING ACTIVITY...BUT IN GENERAL WILL BE A BETTER
CHANCE FROM NEAR I29 AND EAST DURING THE AFTERNOON...AND ESPECIALLY
BY LATER IN THE DAY. AT THIS TIME...SEVERE WEATHER WOULD APPEAR TO
BE A FAIRLY MINIMAL THREAT WITH A LACK OF INSTABILITY...WITH
EFFECTIVE SHEAR PERHAPS INDICATING A MARGINAL ORGANIZATION/HAIL
THREAT THROUGH THE SOUTHERN TIER WITH THE AFTERNOON DEVELOPMENT.
TEMPERATURES DIFFICULT WITH UNCERTAINTY IN CONVECTIVE POTENTIAL...
BUT HEDGED TEMPS DOWN A BIT WITH EXPECTED CLOUDS/PRECIPITATION
AND FAIRLY STABLE LOW LEVEL CONDITIONS. /CHAPMAN
WINDS WILL DECREASE ON THURSDAY NIGHT ALLOWING FOR DECENT
RADIATIONAL COOLING. NOT TO THE EXTENT OF THIS MORNING BUT ENOUGH
THAT WILL LEAN ON THE COOLER GUIDANCE OR A LITTLE BELOW...WHICH
MEANS LOWS FROM THE UPPER 30S TO LOWER 40S.
FRIDAY INTO SUNDAY WILL SEE BROAD SCALE RIDGING DEVELOP WITH WARMING
TO WAY ABOVE NORMAL AGAIN...FOR FRIDAY INTO SUNDAY. HIGHS SATURDAY
MAY EXCEED 90 IN A FEW LOCATIONS IF SOMETHING CLOSER TO THE NAM/GFS
VERIFIES WHILE MID TO UPPER 80S WOULD BE THE WARMEST PER THE ECMWF.
FRIDAY AND SUNDAY STILL WAY ABOVE NORMAL BUT MORE IN THE 70S TO
LOWER 80S...ALTHOUGH NORTHWEST IOWA COULD SEE SOME MID 80S ON SUNDAY
AHEAD OF THE INCOMING FRONT. FRIDAY NIGHT WILL BE WARM WITH SOME
SOUTHERLY FLOW...BUT NOT EXCESSIVELY STRONG. SATURDAY NIGHT WILL BE
VERY WARM WITH STRONGER SOUTHERLY FLOW. LOOKING AT LOWS IN THE MID
TO UPPER 50S SATURDAY NIGHT.
IN THE LATTER PERIODS(SUN/WED)...MODELS STILL IN AGREEMENT WITH
BRINGING A WAVE THROUGH ON MONDAY BUT STILL DIFFER ON STRENGTH AND
PLACEMENT QUITE A BIT. THIS TIME AROUND MODELS ARE A LITTLE LESS
COLD WHICH IS ABOUT THE ONLY TREND TO GRAB ON TO. MOISTURE STILL
LIMITED ON SUNDAY AFTERNOON/SUNDAY NIGHT SO WILL MAINTAIN A CHANCE
FOR THUNDERSTORMS BUT THEY MIGHT BE HARD TO COME BY IF MODELS DO NOT
BEGIN TO INCREASE MOISTURE A LITTLE MORE. OTHERWISE...WHILE COLDER
DURING THIS TIME FRAME STILL LOOKING AT ABOVE NORMAL TEMPERATURES.
LOOKING AT HIGHS ON MONDAY...TUESDAY AND WEDNESDAY IN THE 50S WITH
LOWS GENERALLY IN THE 30S. NO MAJOR CHANCES FOR PRECIPITATION DURING
THIS TIME.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
VFR CONDITIONS WILL BE PREVALENT FOR THE REST OF THE NIGHT. THERE IS
STILL A CHANCE THAT A FEW SHOWERS OR THUNDERSTORMS WILL MAKE IT AS
FAR NORTH AS SIOUX CITY AFTER MIDNIGHT TONIGHT. HOWEVER ELEVATED
CONDITIONS ARE MUCH MORE STABLE IN OUR AREA AS OPPOSED TO THE SOUTH.
ON THURSDAY...MORE RAINFALL IS EXPECTED WITH SHOWERS AND POSSIBLE
EMBEDDED THUNDERTORMS. RIGHT NOW...IT APPEARS THE BEST CHANCES FOR
THUNDERSTORMS WILL BE CONFINED TO THE AFTERNOON HOURS IN NORTHWEST
IOWA AHEAD OF THE SURFACE WIND SHIFT. LEFT EXPLICIT THUNDERSTORM
MENTION OUT OF THE KFSD AND KHON TAF SITES...AS STABILITY INCREASES
TO THE NORTH AND WEST OF OUR NORTHWEST IOWA ZONES. BUT STILL...
CANNOT RULE OUT SOME GENERAL THUNDER NEARLY ANYWHERE IN OUR FORECAST
AREA ON THURSDAY EMBEDDED WITH THE SHOWERS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1148 PM CDT WED MAR 28 2012
.AVIATION...
BREEZY SOUTHERLY WINDS UNDER A MODERATE LLJ HAVE BROUGHT BACK
IMPROVED LOW-LEVEL MOISTURE TO THE TERMINALS. AS WINDS DECREASE
AND VEER TOWARD MORNING...TEMPERATURES WILL COOL TO NEAR THE
DEWPOINT AND THIS COULD RESULT IN A LITTLE FOG/LOW CLOUD FORMATION
IN/AROUND THE TERMINALS. IF ANY SUB-VFR CONDITIONS DEVELOP THEY
SHOULD QUICKLY DIMINISH AS HEATING/MIXING COMMENCES AFTER SUNRISE.
OTHERWISE...ANOTHER WARM DAY...COUPLED WITH A DRYLINE IN THE
AREA...COULD PRODUCE HIGH-BASED CONVECTION THURSDAY
AFTN/EVNG...FAVORING LOCATIONS OFF THE CAPROCK. HENCE...HAVE
CONTINUED A CB REMARK IN THE CDS TAF AFTER 21Z.
&&
.PREV DISCUSSION... /ISSUED 825 PM CDT WED MAR 28 2012/
UPDATE...
FLAT CUMULUS FROM EARLIER HAS DISAPPEARED. LOOKS LIKE A QUIET
NIGHT AHEAD. HAVE REMOVED THUNDER MENTION FROM THE FCST...TWEAKED
SKY GRIDS...AND CLEANED UP THE HWO. NO OTHER CHANGES ATTM.
PREV DISCUSSION... /ISSUED 345 PM CDT WED MAR 28 2012/
SHORT TERM...
CONVOLUTED PATTERN IN PLACE ACROSS THE AREA GIVEN THE LARGE
CONVECTIVELY ENHANCED DISTURBANCE LOCATED TO OUR SE AND GENERAL WEAK
KINEMATICS ACROSS WEST TEXAS. THE DRYLINE HAS REMAINED FAIRLY
DIFFUSE THROUGH THE DAY ALTHOUGH AS OF 3 PM...SOME BACKING OF THE
SFC WINDS HAVE BEEN NOTED ALONG WITH SOME CUMULUS DEVELOPMENT FROM
ERN GAINES COUNTY THROUGH BRISCOE COUNTY. MEANWHILE...AN OUTFLOW BOUNDARY
FROM THE MCS IS MOVING TOWARD THE SRN ROLLING PLAINS WITH NEAR 60F
DEWPOINTS APPROACHING STONEWALL COUNTY. THERE IS LITTLE INDICATION OF A
CONVECTIVE SIGNAL IN ANY OF THE OBJECTIVE GUIDANCE FOR THE REMAINDER
OF THE AFTERNOON AND EVENING...ALTHOUGH RUC ANALYSIS SHOWS THE
ATMOSPHERE TO BE NEARLY UNCAPPED WITH ABOUT 500-1000 J/KG OF CAPE IN
MUCH OF THE ROLLING PLAINS. ALOFT...THERE IS ANOTHER WEAK WAVE
LOCATED IN NRN MX BUT THIS IS LIKELY TOO FAR REMOVED TO PROVIDE
SIGNIFICANT LIFT THIS EVENING. THUS THE ENVIRONMENT IS JUST
MARGINALLY SUPPORTIVE OF CONVECTIVE DEVELOPMENT...WITH WEAK
DRYLINE FORCING WE CAN/T RULE OUT A FEW ISOLD STORMS MAINLY ACROSS
THE SRN SPLNS AND ROLLING PLAINS. THE MAIN STORM THREAT WILL BE
STRONG DOWNDRAFT WINDS BUT IF A STORM CAN TAP INTO THE DEEPER
MOISTURE MOVING IN FROM THE SE THERE MAY BE A MARGINAL HAIL THREAT
AS WELL. THE DRYLINE SHOULD RETREAT THROUGH MOST OF THE FA
OVERNIGHT...WITH HOPEFULLY NO REPEAT OF THE NOCTURNAL MCS
INTERCEPTING OUR MOISTURE RETURN.
SOME LIGHT FOG IS AGAIN EXPECTED EARLY THU MORNING...FOLLOWED BY THE
DRYLINE MIXING INTO THE WESTERN ROLLING PLAINS BY EARLY AFTERNOON.
FCST SDNGS SHOW THAT THE AIRMASS SHOULD WARM UP NICELY IN THE DRY
AIR WITH AFTERNOON HIGHS APPROACHING 90F ACROSS THE SRN AND CENTRAL
SPLNS. GIVEN THE DEGREE OF SFC HEATING...A LITTLE MORE SHARPLY DEFINED
DRYLINE...AND INCREASED LARGE-SCALE ASCENT AS A SHORTWAVE APPROACHES
FROM THE WEST LATE IN THE DAY...WE THINK THE POTENTIAL WILL IMPROVE FOR
CONVECTIVE INITIATION ALONG THE DRYLINE THU AFTERNOON/EVE. FCST
SDNGS SHOW A DEEP DRY-ADIABATIC CONVECTIVE BOUNDARY LAYER ALONG THE
DRYLINE BY LATE AFTERNOON WITH NO INHIBITION...AND MODEST
MLCAPES...AROUND 1000 J/KG OR SO. IN ADDITION...SFC TO 6 KM SHEAR
WILL BE FAIRLY WEAK. THIS WILL LIMIT STORM ORGANIZATION...AND KEEP
STRONG WIND GUSTS AND MARGINALLY LARGE HAIL AS THE MAIN THREATS.
SOME UNCERTAINTY WITH TIMING OF THE LIFT AND DRYLINE LOCATION
PREVENT US FROM GOING HIGHER THAN SLIGHT CHANCE FOR NOW.
LONG TERM...
LARGELY UNEVENTFUL FORECAST FOR MUCH /IF NOT ALL/ OF THE EXTENDED
FORECAST AS MECHANISMS FOR ASCENT APPEAR HARD TO COME BY WITHIN
WEAK WESTERLY UPPER FLOW. EVEN THE RECENT DRYLINE IS PROGGED TO
REMAIN DIFFUSE DURING THE AFTERNOON TOMORROW AND FRIDAY AS IT
MIXES ALONG OR JUST EAST OF THE EDGE OF THE CAPROCK. VERTICAL
CIRCULATIONS WITH SUCH DRYLINES ARE GREATLY REDUCED...BUT WE HAVE
RETAINED SOME MENTION OF PRECIP OFF THE CAP THU NIGHT AS A SHALLOW
S/W TROF IN THE CENTRAL PLAINS GLANCES THE REGION. ALSO...SUBTLE
UPPER DIVERGENCE ASSOCIATED WITH AN APPROACHING UPPER WIND MAX
COULD OFFER A BIT MORE ASSISTANCE FOR ISOLATED THUNDER BEFORE
LIFT DIMINISHES LATE IN THE NIGHT. DESPITE A FRONTOLYSIZING COLD
FRONT DRIFTING SOUTH FROM THE PANHANDLE ON FRIDAY BEHIND THE S/W
TROF...SUBTLE RIDGING ALOFT THROUGHOUT THE PLAINS IS NOT BODING
WELL FOR STORM CHANCES FRIDAY AFTERNOON. NAM CONTINUES TO CONVECT
THIS DAY...ALTHOUGH THIS RECENT OVERZEALOUS NATURE OF THE MODEL
HAS NOT ENJOYED MUCH SUCCESS SO WE ARE QUITE DOUBTFUL OF ITS QPF.
APPROACH OF A PROGRESSIVE PACIFIC TROUGH BY THE WEEKEND WILL
SECURE STRONGER W-SWLY WINDS IN THE LOW-MID TROPOSPHERE.
SUBSEQUENT BOOST OF THICKNESSES SHOULD EASILY PUSH MOST AREA HIGHS
AOA 90 DEG AS THE DRYLINE MIXES NEAR OR JUST BEYOND OUR ERN
COUNTIES. TREND WITH THIS NEXT TROUGH HAS BEEN TO SLOW DOWN A BIT
AMONG THE GFS/ECMWF/GEFS MEAN AND THIS WOULD DELAY THE ARRIVAL OF
STRONGEST WINDS INTO THE PANHANDLE AND NWRN SOUTH PLAINS. BIGGEST
CHANGE HERE CONCERNS THE IMPENDING PACIFIC FRONT THAT IS NOW
PROGGED TO RID MUCH OF THE LONE STAR STATE OF GULF MOISTURE ON
MONDAY AS THE BASE OF THE TROF BECOMES -TILTED AND DIVES INTO THE
OZARKS. THIS WILL LIKELY DELAY THE RETURN OF MOISTURE MUCH LATER
THAN EARLIER FORECASTS SUGGESTED...SO A DRY START TO APRIL APPEARS
IN ORDER. TEMPS SHOULD PLUMMET BLO NORMAL FOR A CHANGE ON MONDAY
WITH GRADUAL MODIFICATION THEREAFTER.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 46 85 44 82 48 / 10 10 10 10 10
TULIA 50 87 48 85 49 / 10 20 10 10 10
PLAINVIEW 50 88 49 86 50 / 10 20 10 10 10
LEVELLAND 49 89 50 87 50 / 10 10 10 10 10
LUBBOCK 54 90 53 88 52 / 10 20 10 10 10
DENVER CITY 49 89 50 86 50 / 10 10 10 10 10
BROWNFIELD 50 90 52 86 51 / 10 20 10 10 10
CHILDRESS 58 89 56 88 54 / 10 20 20 10 10
SPUR 55 88 56 87 53 / 10 20 20 10 10
ASPERMONT 61 87 58 87 56 / 10 20 20 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
23
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1136 PM MDT WED MAR 28 2012
.AVIATION...06Z TAF ISSUANCE...SCATTERED TO BROKEN MID AND HIGH
LEVEL CLOUDINESS WILL MOVE FROM WEST TO EAST ACROSS WYOMING
OVERNIGHT IN ADVANCE OF UPPER LEVEL TROUGH. A SURFACE FRONT
OVER CENTRAL WYOMING WILL MOVE THROUGH SOUTHEAST WYOMING BY
DAYBREAK...AND THE WESTERN PANHANDLE EARLY THURSDAY MORNING.
A BRIEF PERIOD OF MVFR CONDITIONS IN LIGHT RAIN/SNOW SHOWERS WILL
BE POSSIBLE AT RAWLINS. 00Z HRRR AND SREF MODEL GUIDANCE SUGGEST
SOME LOW LEVEL MOISTURE POOLING OVER THE SOUTHERN AND EAST
PANHANDLE...WITH AREAS OF FOG AND LOW CEILINGS DEVELOPING AFTER
08Z. A PERIOD OF IFR TO LIFR CONDITIONS WILL BE POSSIBLE FROM
ALLIANCE TO SIDNEY FROM 08Z TO 12Z. AS WINDS SHIFT TO THE WEST
AND PICK UP...CEILINGS AND FOG SHOULD LIFT. GUSTY NORTHWEST WINDS
WILL THEN OCCUR WITH THE FRONTAL PASSAGE AND LAST THROUGH THURSDAY
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 941 PM MDT WED MAR 28 2012/
UPDATE...LATEST WATER VAPOR LOOP WAS SHOWING A FAIRLY DECENT
SHORTWAVE MOVING THROUGH EASTERN IDAHO WITH ABOUT 100-110KT JET
STREAK MOVING THROUGH THAT REGION. LATEST IR IMAGERY WAS SHOWING A
NARROW BAND OF CLOUD TOPS COOLING ACROSS NORTHERN UTAH STRETCHING
NORTHEAST INTO SOUTHEAST IDAHO. CURRENT OBSERVATIONS ARE NOT
SHOWING MUCH IN THE WAY OF PRECIP FALLING UNDERNEATH THESE COOLING
TOPS. HOWEVER...THIS MAY NOT LAST LONG AS THE COLUMN CONTINUES TO
SATURATE WHICH IS EVIDENT ON THE BLENDED PRECIPITABLE WATER
IMAGERY. THIS BAND OF PRECIP ALSO APPEARS TO BE ASSOCIATED WITH
SOME DECENT INSTABILITY IN THE 700-600MB LAYER WHICH MAY RESULT IN
SOME POCKETS OF HIGHER AMOUNTS (IE .10 INCH). THE MODELS ARE
PROGGING THIS BAND OF PRECIP TO SHIFT EAST AS THE NIGHT WEARS ON
WHICH MAY RESULT IN SOME LIGHT RAIN/SNOW SHOWERS WITH THE BULK OF
THE SNOW SHOWERS POSSIBLE IN ELEVATIONS ABOVE 7000FT. WE DID
INCREASE POPS ACROSS THE WESTERN COUNTIES OVERNIGHT INTO TOMORROW
MORNING AND ALSO RAISED SNOW AMOUNTS TO AROUND AN INCH IN THE
SNOWY AND SIERRA MADRE RANGES.
FOG IS STILL POSSIBLE IN THE SOUTHEAST PANHANDLE OVERNIGHT AS THE
SOUTHERLY FLOW CONTINUES TO ADVECT IN HIGHER DEW POINTS BEFORE THE
TROF PASSES THROUGH.
COX
PREV DISCUSSION... /ISSUED 557 PM MDT WED MAR 28 2012/
LATEST SURFACE ANALYSIS WAS SHOWING A FAIRLY DISTINCT SURFACE
TROF EXTENDING FROM NEAR GILLETTE TO AREAS BETWEEN CASPER AND
RIVERTON SOUTH TO NEAR ROCK SPRINGS. AHEAD OF THIS BOUNDARY THERE
IS ABOUT 2MB PRESSURE FALLS WITH VERY LIMITED PRESSURE RISES
DIRECTLY BEHIND IT. IN FACT...THE BETTER PRESSURE RISES ARE ACROSS
IDAHO WHERE THERMAL GRADIENT IS A LITTLE BETTER. AT THIS
JUNCTURE...I WOULD EXPECT SOUTH/SOUTHWEST FLOW TO PERSIST THROUGH
MUCH OF THE EVENING. THE BETTER SOUTHERLY FLOW SHOULD BE MAINLY
EAST OF THE LARAMIE RANGE WHILE TO THE WEST SHOULD BE MAINLY
SOUTHWEST. LATER TONIGHT THE TROF WILL PASS THROUGH LARAMIE
SHORTLY AFTER MIDNIGHT .CYS AND BFF NEAR DAYBREAK.
THE TAF SITES IN THE PANHANDLE WILL MAINLY SEE SOUTHERLY FLOW. 50
DEGREE DEWPOINT ARE BEGINNING TO KNOCK ON THE DOOR IN SOUTHWEST
NEBRASKA. I AM A BIT CONCERNED THAT SOME OF THIS LOW LEVEL
MOISTURE MAY BLEED INTO SNY OVERNIGHT AND CAUSE SOME LIFR CEILINGS
TO DEVELOP. AS A RESULT...I WENT AHEAD AND MENTIONED A BRIEF
PERIOD OF LIFR CEILINGS SHORTLY AFTER MIDNIGHT...BUT THESE
CEILINGS SHOULD ERODE FAIRLY QUICKLY BEFORE DAYBREAK AS THE TROF
PUSHES THROUGH. AFTER THE TROF PASSES THROUGH...NORTHWEST FLOW
WILL PERSIST ACROSS MOST OF THE TAF SITES TOMORROW AT SPEEDS OF 15
TO 25 KT.
COX
PREV DISCUSSION... /ISSUED 251 PM MDT WED MAR 28 2012/
SHORT TERM...TONIGHT THROUGH SATURDAY...TEMPERATURES TO REMAIN
WELL ABOVE NORMAL AND MINIMAL CHANCES FOR PRECIPITATION THROUGH
SATURDAY. THE ONE CHANCE FOR PRECIPITATION WILL BE TONIGHT WITH
THE PASSAGE OF AN UPPER TROUGH. WATER VAPOR SHOWING AN UPPER LOW
CURRENTLY OVER WESTERN WASHINGTON LIFTING NORTHEAST INTO SOUTHWEST
CANADA. SOUTHWEST FLOW AHEAD OF THE LOW IS STREAMING MOISTURE OUT
OF THE PACIFIC INTO THE SOUTHWEST CONUS. MOST MOISTURE WILL BE
RUNG OUT BEFORE REACHING THE FORECAST AREA. MAINLY EXPECTING
INCREASED CLOUD COVER TONIGHT BUT SOME RAIN AND SNOW IS A GOOD
POSSIBILITY INTO THE FAR WESTERN FORECAST AREA INCLUDING THE SNOWY
AND SIERRA RANGES. PRECIPITATION AMOUNTS IN THESE AREAS...SHOULD
IT OCCUR...WILL BE MINIMAL WITH LESS THAN A TENTH OF AN INCH OF
WATER EXPECTED. HIGHER ELEVATIONS MAINLY ABOVE 10 KFT WILL SEE
TEMPERATURES DROP ENOUGH LATE TONIGHT FOR SNOW. ANY ACCUMULATIONS
SHOULD BE ABOVE 10 KFT WITH AN INCH OR LESS OF ACCUMULATION.
CHANCES FOR MEASURABLE PRECIPITATION VERY LOW EAST OF THE LARAMIE
RANGE TONIGHT. PROGGED SOUNDINGS DRY BELOW ABOUT 10 KFT AGL SUCH
THAT PRECIPITATION ALOFT WILL HAVE A TOUGH TIME REACHING THE
GROUND. EXPECTING TO SEE PLENTY OF RETURNS ON RADAR LATE TONIGHT
BUT SHOULD MOSTLY BE VIRGA.
COULD SEE SOME FOG FORM OVER THE WESTERN NEBRASKA PANHANDLE FOR A
TIME TONIGHT. RELATIVELY JUICY DEW POINTS WILL CONTINUE TO ADVECT
INTO THE AREA THIS EVENING WITH DEW POINTS WELL INTO THE 40S
AROUND SIDNEY AND ALLIANCE. WINDS WILL BECOME LIGHT AND VARIABLE
POSSIBLE ALLOW FOR RADIATION FOG TO FORM. FORTUNATELY WINDS WILL
SHIFT TO THE WEST AS THE UPPER TROUGH APPROACHES. THIS WILL
SIGNIFICANTLY MITIGATE THE POTENTIAL FOR WIDESPREAD OR DENSE FOG
TONIGHT.
SLIGHTLY COOLER THURSDAY AS COOLER AIR WILL MOVE INTO THE AREA
BEHIND THE TROUGH TONIGHT. EVEN WITH THE COOLER AIR IN PLACE HIGH
TEMPERATURES WILL SEE BE AROUND 15 DEGREES ABOVE NORMAL THURSDAY.
RIDGING TOMORROW NIGHT INTO FRIDAY WILL ALLOW FOR HIGH
TEMPERATURES TO WARM BACK TO 20 TO 25 DEGREES ABOVE NORMAL. NOT
EXPECTING RECORD HIGH TEMPERATURES FRIDAY BUT RECORD HIGH ARE
A GOOD BET FOR SATURDAY AS VERY WARM AIR PUSHES NORTH AHEAD OF
THE NEXT UPPER LEVEL SYSTEM.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...ANOTHER MILD NIGHT
IS EXPECTED SATURDAY NIGHT BEFORE A PACIFIC COLD FRONT MOVES FROM
WEST TO EAST ACROSS THE AREA SUNDAY MORNING. SHOULD SEE COOLER
TEMPS FROM SATURDAY...ALTHOUGH VALUES STILL LOOK TO REMAIN ABOVE
NORMAL. THE OVERALL UPPER LEVEL TROUGH ASSOCIATED WITH THIS FRONT
LOOKS TO BE SLIGHTLY SLOWER AND DIGGING FURTHER SOUTH WITH THE
12Z MODELS...AND MID LEVEL MOISTURE LOOKS SUFFICIENT TO BRING A
CHANCE FOR RAIN AND SNOW ACROSS THE AREA SUNDAY AND SUNDAY NIGHT.
BUMPED UP POPS SOME FOR THIS SCENARIO AS THE MODELS ARE FAIRLY
CONSISTENT WITH EACH OTHER WITH THIS TREND. NORTHWEST WINDS BEHIND
THE FRONT WILL BE MODERATE TO STRONG AT TIMES ON SUNDAY AS
HIGH PRESSURE BUILDING IN FROM THE WEST TIGHTENS THE LLVL PRESSURE
GRADIENT...ESPECIALLY IN THE WIND CORRIDOR REGION. THE FRONT WILL
PUSH OFF TO THE EAST SUNDAY NIGHT AND MONDAY WITH THE GRADIENT
REMAINING RELATIVELY STRONG THROUGH THIS TIME. THE MAIN TROUGH
WILL MOVE OVERHEAD THEN AS WELL...SO THE COMBINATION OF SUBSIDENCE
ALOFT AND THE GRADIENT WILL KEEP WINDS ELEVATED ON MONDAY WITH
LESS WIND FOR TUESDAY. MONDAY WILL CONTINUE TO BE
COOLER...RELATIVELY SPEAKING...BUT RIDGING WILL RETURN TO THE
ROCKIES FOR TUESDAY WITH A RISE IN TEMPS ONCE AGAIN. DRY AND
BREEZY CONDITIONS WILL PERSIST THROUGH WEDNESDAY WITH A BETTER
CHANCE FOR CRITICAL FIRE WEATHER CONDITIONS TO BE MET DURING THIS
TIME.
&&
FIRE WEATHER...
RED FLAG WARNING TO EXPIRE THIS EVENING AS WINDS WILL DIE
OFF AND HUMIDITY RECOVERS. COOLER TEMPERATURES YIELDING HIGHER
HUMIDITY THURSDAY SHOULD PRECLUDE RED FLAG CONDITIONS ALTHOUGH
MARGINAL CONDITIONS ARE EXPECTED FOR A FEW HOURS TOWARD CHEYENNE
IN THE AFTERNOON...BUT CERTAINLY NOTHING WIDESPREAD. TROUGH
PASSING ACROSS THE AREA TONIGHT MAY PRODUCE SOME LIGHT RAIN
SHOWERS TOWARD THE RAWLINS AFTER MIDNIGHT WITH SOME SNOW
POSSIBLE IN THE HIGHER ELEVATIONS OF THE SNOWY AND SIERRA RANGES.
ANY ACCUMULATIONS SHOULD BE AN INCH OR LESS. TEMPERATURES FRIDAY
WILL BE SIMILAR TO THAT OF TODAY AS WILL WIND SPEEDS BUT HUMIDITY
VALUES MAY NOT DROP AS FAR. AT THIS TIME IT APPEARS MARGINAL FOR
RED FLAG FRIDAY DEPENDING ON SURFACE DEW POINTS...HOWEVER...
WIDESPREAD RED FLAG CONDITIONS ARE EXPECTED SATURDAY AS NEAR
RECORD TEMPERATURES AND GUSTY WEST TO SOUTHWEST WINDS DEVELOP.
ACTUALLY IT WILL BE VERY WINDY SATURDAY. DRY THURSDAY THROUGH
SATURDAY WITH VIRTUALLY NO CHANCE FOR PRECIPITATION.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...TJT
LONG TERM/AVIATION...JAMSKI
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
438 AM MDT THU MAR 29 2012
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 438 AM MDT THU MAR 29 2012
AT 3 AM THE COLD FRONT WAS ACROSS THE NW HALF OF THE FORECAST AREA
AND SAGGING SOUTH. DEWPOINTS CLIMBING FROM TEENS TO 20-30S WITH
THE FRONT. ONLY LIGHT SHOWERS HAVE BEEN CAUGHT BY SURFACE
REPORTING STATIONS IN THE PARK AND ELK MOUNTAINS. GENERALLY
FOLLOWED THE HRRR LIGHT PRECIP PATTERN FOR THIS MORNING. THE WEAK
COLD CORE BRUSHES THE NORTH THIS MORNING WITH MARGINAL INSTABILITY
SHRINKING INTO THE EARLY AFTERNOON. OTHERWISE TEMPERATURES WILL BE
3-5 DEGREES COOLER THAN ON WEDNESDAY BUT WILL STILL BE WELL ABOVE
NORMAL. WINDS WILL VEER TO NW BEHIND THE FRONT AND DIMINISH
THROUGH THE AFTERNOON.
A SECOND WEAK WAVE PROGGED TO PASS THIS EVENING BUT LOOKS MOISTURE
STARVED BELOW 500MB. SO LOWERED POPS FOR THIS EVENING. THE MID-
HIGH CLOUDS WILL SHIFT EAST AFTER MIDNIGHT BUT MAY LIMIT THE LOW
TEMPERATURES OVERNIGHT ESPECIALLY IN WESTERN COLORADO. WARMING
TREND BEGINS ON FRIDAY IN A FLAT BENIGN FLOW.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 438 AM MDT THU MAR 29 2012
DRY AND UNSEASONABLY WARM WEATHER WILL CONTINUE INTO THE EARLY
PART OF THE WEEKEND AS FLOW SHIFTS TO THE SOUTHWEST AHEAD OF AN
APPROACHING PACIFIC TROUGH. IN FACT...INDICATIONS ARE THAT HIGHS
WILL BE NEAR RECORD LEVELS. A TIGHTENING PRESSURE GRADIENT WILL
GENERATE STRONG AND GUSTY SOUTHWEST WINDS WHICH WILL NOT ONLY HELP
LIFT HIGHS NEARLY 20 DEGREES ABOVE NORMAL BUT WILL ALSO DRIVE RH
DOWN...POTENTIALLY YIELDING CRITICAL FIRE WEATHER CONDITIONS.
MODELS WERE CONSISTENT IN MOVING THE TROUGH OVER THE GREAT BASIN
SATURDAY NIGHT. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM IS
EXPECTED TO JUST REACH THE GREEN RIVER SUNDAY MORNING. PRE-
FRONTAL WINDS WILL CONTINUE MUCH OF THE NIGHT HELPING TO BUOY
OVERNIGHT LOWS. PRECIPITATION WILL LARGELY HOLD OFF UNTIL THE
FRONT SWEEPS ACROSS THE REGION SUNDAY. SNOW LEVELS WILL BEGIN NEAR
THE TREE-LINE...LOWERING WITH FROPA TO VALLEY FLOORS ACROSS THE
NORTH AND THE HIGHER CENTRAL VALLEYS. LATEST SNOWFALL OUTPUT
SUGGESTS AMOUNTS WILL LARGELY BE BELOW ADVISORY LEVELS...THOUGH
BLOWING SNOW AND REDUCED VISIBILITY COULD CREATE SOME TRAVEL
DIFFICULTIES. CLOUDS...SHOWERS AND CAA BEHIND THE FRONT WILL
RESULT IN MUCH COOLER TEMPERATURES SUNDAY...THOUGH STILL JUST A
BIT ABOVE NORMAL.
SNOW IS EXPECTED TO LINGER ALONG THE CONTINENTAL DIVIDE SUNDAY
NIGHT...LIKELY ENDING BY MONDAY MORNING. TEMPERATURES WILL REMAIN
COOL MONDAY UNDER A NORTHWEST FLOW REGIME. LOOK FOR A WARMING
TREND FOR THE MIDDLE OF THE WEEK AS FLOW BECOMES ZONAL TUESDAY
...THEN SHIFTS TO THE SOUTHWEST WEDNESDAY. DRY CONDITIONS ARE
EXPECTED THROUGH MIDWEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z EARLY FRIDAY MORNING)
ISSUED AT 438 AM MDT THU MAR 29 2012
AT 09Z A WEAK COLD FRONT WAS SOUTH OF THE I-70 CORRIDOR AND
SHIFTING EAST. CURRENT CLOUD HEIGHTS BEHIND THE FRONT ARE BETWEEN
7000 TO 10000 FT AGL FOR PREVAILING VFR CONDITIONS AT ALL TAF
SITES. LIGHT SHOWERS AND LOCALLY LOWERED CEILINGS ARE POSSIBLE
THROUGH 18Z FOR MTNS IN THE VCNTY OF KSBS SOUTH TO KEGE AND KASE.
THESE ISOLATED SHOWERS END AFTER 21Z.
&&
.FIRE WEATHER...
ISSUED AT 438 AM MDT THU MAR 29 2012
A PACIFIC TROUGH WILL MOVE INTO THE WESTERN GREAT BASIN SATURDAY
RESULTING IN A SHIFT TO SOUTHWEST FLOW. A TIGHTENING PRESSURE
GRADIENT COMBINED WITH NEAR RECORD WARMTH WILL HELP MIX STRONG
WINDS ALOFT TO THE SURFACE DURING THE AFTERNOON AND EVENING. THE
DEEP MIXING WILL ALSO SERVE TO REDUCE RELATIVE HUMIDITY BELOW 15
PERCENT ACROSS MUCH OF THE REGION DURING PEAK HEATING. THAT
SAID...NOT COMFORTABLE ISSUING FIRE WEATHER WATCH FOR THE LATE 5TH
AND 6TH PERIODS AND WILL LET LATER SHIFTS PULL THE TRIGGER AS THE
DETAILS COME TOGETHER.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM.....JOE
LONG TERM......NL
AVIATION.......JOE
FIRE WEATHER...NL
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
945 AM EDT THU MAR 29 2012
.UPDATE (REST OF TODAY AND TONIGHT)...
13Z WATER VAPOR AND H4 RUC ANALYSIS SHOWS AND AMPLIFIED BUT
PROGRESSIVE NORTHERN STREAM FLOW. NORTHERN STREAM ARRIVES OVER THE
PACIFIC NORTHWEST COAST WITH AN ELONGATED SHORTWAVE NEAR THE
CONTINENTAL DIVIDE. THE FLOW THEN RIDGING NORTHWARD INTO
SOUTH-CENTRAL CANADA/WESTERN GREAT LAKES BEFORE DIVING BACK
SOUTHEASTWARD OVER THE NE/MID-ATLANTIC STATES. CLOSER TO HOME WE
FIND BROAD UPPER RIDGING IN PLACE OVER THE EASTERN GULF OF MEXICO
AND THE FL PENINSULA. A WEAK SHORTWAVE CURRENTLY OVER TEXAS WILL
SLOWLY MOVE EAST ALONG THE NORTHERN GULF COAST DURING THE NEXT 24-36
HOURS AND POTENTIALLY BRING A SLIGHT ENHANCEMENT TO THE SHOWER/STORM
CHANCES OVER OUR NORTHERN ZONES FRIDAY AFTERNOON/EVENING. WV IMAGERY
HAS SHOWN GRADUAL MOISTURE ADVECTION INTO OUR REGION WITHIN THE
UPPER LEVELS. THIS TREND IS SEEN CLEARLY OVER THE PAST 24 HOURS
LOOKING AT THE KTBW SOUNDING PROFILE...WHERE DEWPOINT DEPRESSIONS
HAVE SIGNIFICANTLY DECREASED ABOVE THE H5 LEVEL. THE 12Z SOUNDING
STILL SHOWS THAT WE ARE DEALING WITH A HEALTHY LAYER OF DRY AIR
BETWEEN 800-500MB EARLY THIS MORNING. MID-LEVEL THETA-E VALUES
WITHIN THIS LAYER REMAIN BELOW 320K AND ARE RATHER HOSTILE TO DEEP
CONVECTION...HOWEVER...MODEL FORECAST SOUNDING ALL SHOW THAT EVEN
THIS LAYER WILL MOISTEN SOMEWHAT BY THE END OF THE DAY. THIS TREND
SHOULD LEAD TO AT LEAST A FEW GENERALLY LATE AFTERNOON/EVENING
SHOWERS/STORMS ASSOCIATED WITH THE LOW LEVEL FOCUS OF THE SEA-BREEZE.
AT THE SURFACE...GRADIENT IS QUITE WEAK ACROSS THE FORECAST AREA
THIS MORNING WITH THE SUBTROPICAL RIDGE AXIS EXTENDING ACROSS THE
CENTRAL FLORIDA PENINSULA. MOSTLY SUNNY SKIES ARE GIVING WAY TO
ANOTHER QUICK TEMPERATURE RISE. PAST SEVERAL DAYS...A TIGHTER
GRADIENT HAS ALLOWED FOR EXCELLENT DIURNAL MIXING UP TO AROUND THE
7KFT LEVEL. MAY NOT SEE QUITE AS EFFICIENT MIXING TODAY...BUT EVEN
6000-6500KFT WILL YIELD LATE AFTERNOON HIGH TEMPS INTO THE MIDDLE
80S INLAND. DO ANTICIPATE SEA-BREEZE CIRCULATIONS TO DEVELOP BY
EARLY AFTERNOON WITH WILL HELP HOLD DOWN TEMPS A FEW DEGREES CLOSE
TO THE COAST.
AS MENTIONED ABOVE...THIS SEA-BREEZE COMBINED WITH AN INCREASINGLY
FAVORABLE COLUMN FOR DEEP CONVECTION SHOULD YIELD ISOLATED TO WIDELY
SCATTERED SHOWERS BY LATE IN THE DAY. MANY OF THE HI-RESOLUTION
ENSEMBLE CAM (CONVECTION ALLOWING MODELS) AGREE WITH THIS SOLUTION.
AT THIS TIME THERE IS NO CLEAR BIAS NORTH TO SOUTH AS TO WHERE THE
OVERALL BEST CHANCES FOR THE "POP UP" SHOWERS WILL BE...AND WILL
LEAVE THE GENERAL 20% RAIN CHANCES INHERITED FROM THE PREVIOUS
FORECAST.
WITHOUT ANY CLEAR UPPER LEVEL SUPPORT...SHOULD SEE A FEW LINGERING
SHOWERS ONLY UNTIL AROUND 02-03Z THIS EVENING BEFORE FADING WITH THE
LOSS OF DIURNAL HEATING. THE REMAINDER OF THE NIGHT LOOKS QUIET WITH
JUST A FEW HIGHER LEVEL CLOUDS. INLAND LOW TEMPS WILL DROP TO THE
UPPER 50S/LOWER 60S...WITH MIDDLE 60S ALONG THE COAST.
&&
.AVIATION...
A FEW SHOWERS MAY DEVELOP TO THE EAST OF THE TERMINAL SITES
DURING MID TO LATE AFTERNOON...OTHERWISE VFR CONDITIONS ARE
EXPECTED DURING THE NEXT 24 HOURS. SOUTHEAST TO SOUTH WINDS
AROUND 5 KNOTS THIS MORNING...WILL BECOME SOUTHWEST TO WEST
AROUND 10 KNOTS AFTER 18Z AS THE SEA BREEZE DEVELOPS. WINDS
WILL BECOME LIGHT AND VARIABLE AFTER 30/02Z TONIGHT.
&&
.MARINE...
WINDS AND SEAS ARE EXPECTED TO REMAIN GENERALLY BELOW HEADLINE
CRITERIA THROUGH FRIDAY. LIGHT AND VARIABLE FLOW THIS MORNING WILL
TURN ONSHORE DURING THE AFTERNOON WITH THE DEVELOPMENT OF LOCAL
SEA-BREEZE CIRCULATIONS. LARGE SCALE FLOW WILL BECOME MORE
SOUTHERLY/PARALLEL TO THE COASTLINE OVERNIGHT AND THEN VEER OUT
OF THE SOUTHWEST BY THE END OF FRIDAY IN ADVANCE OF AN APPROACHING
WEAK COLD FRONT.
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...14/MROCZKA
AVIATION...57/MCMICHAEL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
930 AM CDT THU MAR 29 2012
...UPDATES TO MORNING FORECAST...
.UPDATE...
ISSUED AT 930 AM CDT THU MAR 29 2012
HAVE CANCELLED THE DENSE FOG ADVISORY FOR TREGO/ELLIS COUNTIES AS
THE FOG HAS BEEN ERODING RAPIDLY OUT OF THAT AREA. MORNING TEMPERATURES
ARE ALSO A LITTLE WARMER IN AREAS OUT ALONG AND WEST OF HIGHWAY
83. HAVE MADE A FEW TWEAKS TO ACCOUNT FOR THIS AS WELL.
UPDATE ISSUED AT 634 AM CDT THU MAR 29 2012
SOUTHWEST WINDS WERE DEVELOPING ACROSS WESTERN KANSAS WITH LOWER
DEWPOINTS BEGINNING TO ADVECT INTO PORTIONS OF THE DENSE FOG
ADVISORY AREA. SATELLITE, SURFACE OBS AND PHONE CALLS AT OF 6 AM
INDICATED PATCH FOG AT BEST WERE OCCURRING SOUTH OF INTERSTATE 70.
AS A RESULT WILL TRIM SEVERAL COUNTIES OUT OF THE DENSE FOG
ADVISORY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 217 AM CDT THU MAR 29 2012
.SYNOPSIS...
ISSUED AT 217 AM CDT THU MAR 29 2012
00Z 300 HPA SYNOPTIC MAP ANALYSIS SHOWS A 95 KT JET PUSHING ASHORE ACROSS
THE PACIFIC NORTHWEST IN ASSOCIATION WITH BROAD TROUGH EXTENDING FROM
THE PACNW TO THE NORTHERN ROCKIES. WEAKER 50 TO 75 KT BROAD W/NW FLOW
EXTENDED ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION.
THE 500 HPA FLOW PATTERN SHOWED THE TROUGH AXIS IN ASSOCIATION WITH
THE AFOREMENTIONED JET STREAK FROM THE NORTHEAST PACIFIC AND SE ACROSS
THE GREAT BASIN. LOWER IN THE ATMOSPHERE...NAMELY THROUGH THE 700 AND
850 HPA LAYERS, THE MOST INTERESTING ITEM WAS WARM AND DRY FLOW IN
THE LEE OF THE ROCKIES. AT THE SFC, MSAS SURFACE PRESSURE ANALYSIS SHOWED
A WEAK LOW PRESSURE CENTER ACROSS SE COLORADO. A WARM FRONT WAS EXTENDING
FROM THIS FEATURE ACROSS CENTRAL KANSAS. RICH MOISTURE AS MARKED BY
DEWPOINTS IN THE 60S DEG F EXTENDED ACROSS SOUTH CENTRAL KANSAS.
THIS MORNING:
THE MAIN ITEM OF CONCERN DURING THE MORNING PERIOD IS THE LIKELIHOOD
FOR DENSE FOG. HRRR AND MOS IS SUGGESTING THE GREATEST POTENTIAL FOR
DENSE FOG ACROSS WEST CENTRAL KANSAS THIS MORNING. THIS IS ALSO REFLECTED
IN 00Z NAM BUFKIT DATA. THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE
DEWPOINTS (LOW 50S DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A
WARM FRONT THAT WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
TODAY:
THE FOG SHOULD DISSIPATE/MIX OUT BY MID MORNING. THE REST OF THE SENSIBLE
WEATHER FOR TODAY WILL BE FAIRLY TRANQUIL. A BROAD UPPER LEVEL SHORTWAVE
TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS TODAY. SW KANSAS WILL BE
ON THE SOUTHEASTERN FRIDGES OF THE 400 HPA PV ANOMALY TODAY. AS A RESULT
OF THE AFOREMENTIONED UPPER LEVEL DYNAMICS SLIDING EAST THROUGH THE
DAY, THE RESULTANT SURFACE LOW WILL CONTINUE TO SLIDE TO THE EAST ACROSS
NORTHERN KANSAS AS WELL. A BIT OF DOWNSLOPE AND MIXING ACROSS THE SOUTHWESTERN
COUNTIES THIS AFTERNOON WILL PROVIDE VERY WARM TEMPERATURES NEAR THE
OKLAHOMA BORDER. EXPECT MID 80S DEG F IN THIS AREA. FURTHER NORTH, ONLY
LOOKING FOR UPPER 70S DEG F TO AROUND 80 DEG F AS A WEAK COLD FRONT
MOVES THROUGH EARLIER IN THE DAY. THE DRYLINE WITH UPPER 50S TO LOWER
60S DEG F DEWPOINTS WILL MIX EAST TODAY. THIS DRYLINE SHOULD BE LOCATED
ACROSS SOUTH CENTRAL KANSAS BY THIS AFTERNOON.
TONIGHT:
EVENTUALLY THE PACIFIC FRONT FOLLOWING BEHIND THE DRYLINE WILL CATCH
UP CLOSER TO THE DRYLINE. HAVE DISCOUNTED THE 00Z GFS SOLUTION AS THIS
MODEL SEEMS TO BE SUFFERING FROM BOUNDARY LAYER MOISTURE PROBLEMS AND
THE RESULTANT QPF LOOKS A LITTLE OVERZEALOUS. MAINLY STUCK WITH THE
00Z NAM AND 00Z WRF-NMM FOR POPS THIS EVENING. CONFINED POPS MAINLY ACROSS
SOUTH CENTRAL KANSAS AS TEMPERATURES IN THE 80S DEG F COMBINED WITH
NEAR 60 DEG F DEWPOINTS WILL CREATE ENOUGH SBCAPE IN THE 2000-2500 J/KG
RANGE SOUTH CENTRAL KANSAS. FORECAST SOUNDINGS SHOW CONSIDERABLE CINH
REMAINING ACROSS SC KS THROUGH MUCH OF THE DAY AND THEN FINALLY ERODING
BY TONIGHT. 0 TO 6 KM SHEAR OF AROUND 30 KT COULD SUPPORT THE NOTION
FOR MORE ORGANIZED CONVECTION ACROSS SE BARBER COUNTY. WILL HIGHLIGHT
THESE CONCERNS IN THE HWO. OTHER INFORMATION REGARDING CONVECTION CAN
BE FOUND IN THE SWODY1 PRODUCT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 328 AM CDT THU MAR 29 2012
A WEAK AREA OF HIGH PRESSURE WILL BUILD INTO WESTERN KANSAS EARLY
FRIDAY AS A COLD FRONT SINKS SOUTH INTO OKLAHOMA. THIS FRONT WILL
BECOME STATIONARY BY MID DAY AS AN UPPER LEVEL DISTURBANCE
EMBEDDED IN THE WEST NORTHWEST FLOW CROSSES INTO WESTERN KANSAS.
BOTH THE NAM AND GFS PLACES THE BETTER LATE DAY INSTABILITY
NEAR/JUST SOUTH OF THE OKLAHOMA BORDER WHICH IS ALSO WHERE THE
BETTER 850MB WARM AIR ADVECTION/ISENTROPIC LIFT IS FORECAST TO
IMPROVE AHEAD OF THIS UPPER WAVE. BASED ON THE LIFT,MOISTURE AND
INSTABILITY AT 00Z SATURDAY AHEAD OF AN UPPER LEVEL DISTURBANCE
WILL CONTINUE TO LEAN TOWARDS A DRY FORECAST FOR SOUTHWEST KANSAS.
DID HOWEVER KEEP THE 12 TO NEAR 15 PERCENT CHANCE OF PRECIPITATION
IN THE MEDICINE LODGE AND COLDWATER AREAS BASED ON HOW CLOSE THESE
LOCATIONS WILL BE TO THE MOISTURE/LIFT NORTH OF THE STATIONARY
FRONT EARLY FRIDAY NIGHT.
AS FOR TEMPERATURES...BASED ON 850MB TEMPERATURES AT 00Z SATURDAY
THE PREVIOUS FORECAST STILL LOOKS ON TRACK FOR HIGHS FRIDAY
AFTERNOON. DID HOWEVER LOWER TEMPERATURES IN SOUTHWEST KANSAS NEAR
THE OKLAHOMA BORDER BY A FEW DEGREES GIVEN THE BETTER CHANCES FOR
MORE CLOUD COVER IN THIS LOCATION FRIDAY AFTERNOON.
ONCE THIS SYSTEM MOVES EAST OF WESTERN KANSAS FRIDAY NIGHT A
WESTERLY DOWNSLOPE FLOW WILL THEN BEGIN TO DEVELOP. 24 HOUR 850MB
TEMPERATURE TRENDS OVER THE WEEKEND PERIOD SUPPORTS A NICE WARM
UP. 80S WILL BE LIKELY BOTH DAYS. A FEW LOCATIONS MAY EVEN
APPROACH 90 DEGREES ALONG AND SOUTH OF DODGE CITY IF THE 00Z
MONDAY 850MB TEMPERATURES FROM THE GFS AND ECMWF VERIFIES.
ON SUNDAY IT WILL ALSO BE WINDY AS A TIGHT SURFACE PRESSURE GRADIENT
DEVELOPS ACROSS WESTERN KANSAS IN RESPONSE TO AN AREA OF LOW
PRESSURE DEEPENING ALONG THE LEE OF THE ROCKIES. THIS DEEPENING
SURFACE LOW WILL THEN SLIDE EAST INTO WESTERN KANSAS SUNDAY NIGHT
AS AN UPPER LEVEL TROUGH EXITS THE ROCKIES AND MOVES OUT INTO THE
CENTRAL PLAINS. AN ELEVATED MIXED LAYER SHOULD INHIBIT
PRECIPITATION CHANCES ON SUNDAY AHEAD OF THIS NEXT SYSTEM. DRY AIR
MIXING DOWN TO THE SURFACE WILL INCREASE THE FIRE DANGER LEVELS
ACROSS WESTERN KANSAS...ESPECIALLY WEST OF THE DRY LINE.
A COLD FRONT WILL MOVE ACROSS WESTERN KANSAS EARLY MONDAY AS THIS
UPPER LEVEL TROUGH CROSSES INTO THE CENTRAL PLAINS. THE GFS
SUGGESTS SOME IMPROVING MID LEVEL INSTABILITY AS THE UPPER LEVEL
TROUGH CROSSES WESTERN KANSAS DURING THE DAY. BASED ON WHERE THE
BETTER MOISTURE RETURN WILL BE AHEAD OF THIS SYSTEM HAVE DECIDED
TO STAY CLOSE TO THE ALLBLEND ON PRECIPITATION CHANCES. THIS WOULD
PLACE A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS PORTIONS OF NORTH
CENTRAL KANSAS. AS FOR TEMPERATURES HAVE DECIDED TO FOLLOW THE
GENERAL 925-850MB TEMPERATURE TRENDS FROM THE GFS AND ECMWF. THIS
WOULD FAVOR HIGHS MAINLY IN THE 60S ON MONDAY AS THIS UPPER LEVEL
TROUGH PASSES.
A WARMING TREND WILL RETURN BY MID WEEK AS AN UPPER LEVEL RIDGE
CROSSES THE ROCKIES AND A WESTERLY DOWNSLOPE FLOW IMPROVES ACROSS
EASTERN COLORADO AND WESTERN KANSAS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 606 AM CDT THU MAR 29 2012
10Z SURFACE ANALYSIS CONTINUES TO SUPPORT THE 06Z NAM AND 08Z
HRRR IN PLACING THE BETTER OPPORTUNITY FOR LIFR FOG/STATUS ACROSS
NORTH CENTRAL KANSAS, NEAR HAYS, EARLY THIS MORNING WHERE A MOIST
UPSLOPE FLOW CONTINUES. AS A RESULT WILL KEEP LIFR CIGS/VSBYS GOING
FOR THE NEXT FEW HOURS. FURTHER SOUTH AT GCK AND DDC A GUSTY
SOUTHWEST WIND HAD ALREADY DEVELOPS WITH LOWER DEWPOINTS NOW BEING
ADVECTED INTO THIS REGION SO VFR CONDITIONS ARE EXPECTED. MET AND
HRRR WERE IN DECENT AGREEMENT WITH TIMING OF THE NORTHWEST WINDS
DEVELOPING DURING THE EARLY AFTERNOON AS A WEAK COLD FRONT CROSSES
WESTERN KANSAS SO WILL STAY CLOSE TO MET TIMING OF THE WIND SHIFT
LATER TODAY.
&&
.FIRE WEATHER...
ISSUED AT 328 AM CDT THU MAR 29 2012
GUSTY SOUTHWEST WINDS WILL DEVELOP ON SUNDAY AS AN AREA OF LOW
PRESSURE DEEPENS ACROSS NORTHEAST COLORADO. SUSTAINED WINDS OF 20 TO
30 MPH WILL BE LIKELY. IN ADDITION AFTERNOON RELATIVE HUMIDITIES
ARE EXPECTED TO FALL BACK INTO THE TEENS WEST OF A DRYLINE WHICH
CURRENTLY IS EXPECTED TO EXTEND FROM NEAR SCOTT CITY TO GARDEN
CITY TO NEAR LIBERAL. THIS COMBINATION WILL RESULT IN VERY HIGH TO
CRITICAL FIRE WEATHER CONDITIONS ACROSS PORTIONS OF WESTERN KANSAS
SUNDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 83 48 78 51 / 10 10 10 10
GCK 82 47 77 51 / 0 10 10 0
EHA 81 46 76 51 / 0 10 10 0
LBL 85 47 77 49 / 0 10 10 10
HYS 79 47 79 50 / 0 10 10 0
P28 84 53 80 56 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GERARD
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
643 AM CDT THU MAR 29 2012
...UPDATED TO CANCEL PARTS OF THE DENSE FOG ADVISORY...
.UPDATE...
ISSUED AT 634 AM CDT THU MAR 29 2012
SOUTHWEST WINDS WERE DEVELOPING ACROSS WESTERN KANSAS WITH LOWER
DEWPOINTS BEGINNING TO ADVECT INTO PORTIONS OF THE DENSE FOG
ADVISORY AREA. SATELLITE, SURFACE OBS AND PHONE CALLS AT OF 6 AM
INDICATED PATCH FOG AT BEST WERE OCCURRING SOUTH OF INTERSTATE 70.
AS A RESULT WILL TRIM SEVERAL COUNTIES OUT OF THE DENSE FOG
ADVISORY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 217 AM CDT THU MAR 29 2012
.SYNOPSIS...
ISSUED AT 217 AM CDT THU MAR 29 2012
00Z 300 HPA SYNOPTIC MAP ANALYSIS SHOWS A 95 KT JET PUSHING ASHORE ACROSS
THE PACIFIC NORTHWEST IN ASSOCIATION WITH BROAD TROUGH EXTENDING FROM
THE PACNW TO THE NORTHERN ROCKIES. WEAKER 50 TO 75 KT BROAD W/NW FLOW
EXTENDED ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION.
THE 500 HPA FLOW PATTERN SHOWED THE TROUGH AXIS IN ASSOCIATION WITH
THE AFOREMENTIONED JET STREAK FROM THE NORTHEAST PACIFIC AND SE ACROSS
THE GREAT BASIN. LOWER IN THE ATMOSPHERE...NAMELY THROUGH THE 700 AND
850 HPA LAYERS, THE MOST INTERESTING ITEM WAS WARM AND DRY FLOW IN
THE LEE OF THE ROCKIES. AT THE SFC, MSAS SURFACE PRESSURE ANALYSIS SHOWED
A WEAK LOW PRESSURE CENTER ACROSS SE COLORADO. A WARM FRONT WAS EXTENDING
FROM THIS FEATURE ACROSS CENTRAL KANSAS. RICH MOISTURE AS MARKED BY
DEWPOINTS IN THE 60S DEG F EXTENDED ACROSS SOUTH CENTRAL KANSAS.
THIS MORNING:
THE MAIN ITEM OF CONCERN DURING THE MORNING PERIOD IS THE LIKELIHOOD
FOR DENSE FOG. HRRR AND MOS IS SUGGESTING THE GREATEST POTENTIAL FOR
DENSE FOG ACROSS WEST CENTRAL KANSAS THIS MORNING. THIS IS ALSO REFLECTED
IN 00Z NAM BUFKIT DATA. THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE
DEWPOINTS (LOW 50S DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A
WARM FRONT THAT WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
TODAY:
THE FOG SHOULD DISSIPATE/MIX OUT BY MID MORNING. THE REST OF THE SENSIBLE
WEATHER FOR TODAY WILL BE FAIRLY TRANQUIL. A BROAD UPPER LEVEL SHORTWAVE
TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS TODAY. SW KANSAS WILL BE
ON THE SOUTHEASTERN FRIDGES OF THE 400 HPA PV ANOMALY TODAY. AS A RESULT
OF THE AFOREMENTIONED UPPER LEVEL DYNAMICS SLIDING EAST THROUGH THE
DAY, THE RESULTANT SURFACE LOW WILL CONTINUE TO SLIDE TO THE EAST ACROSS
NORTHERN KANSAS AS WELL. A BIT OF DOWNSLOPE AND MIXING ACROSS THE SOUTHWESTERN
COUNTIES THIS AFTERNOON WILL PROVIDE VERY WARM TEMPERATURES NEAR THE
OKLAHOMA BORDER. EXPECT MID 80S DEG F IN THIS AREA. FURTHER NORTH, ONLY
LOOKING FOR UPPER 70S DEG F TO AROUND 80 DEG F AS A WEAK COLD FRONT
MOVES THROUGH EARLIER IN THE DAY. THE DRYLINE WITH UPPER 50S TO LOWER
60S DEG F DEWPOINTS WILL MIX EAST TODAY. THIS DRYLINE SHOULD BE LOCATED
ACROSS SOUTH CENTRAL KANSAS BY THIS AFTERNOON.
TONIGHT:
EVENTUALLY THE PACIFIC FRONT FOLLOWING BEHIND THE DRYLINE WILL CATCH
UP CLOSER TO THE DRYLINE. HAVE DISCOUNTED THE 00Z GFS SOLUTION AS THIS
MODEL SEEMS TO BE SUFFERING FROM BOUNDARY LAYER MOISTURE PROBLEMS AND
THE RESULTANT QPF LOOKS A LITTLE OVERZEALOUS. MAINLY STUCK WITH THE
00Z NAM AND 00Z WRF-NMM FOR POPS THIS EVENING. CONFINED POPS MAINLY ACROSS
SOUTH CENTRAL KANSAS AS TEMPERATURES IN THE 80S DEG F COMBINED WITH
NEAR 60 DEG F DEWPOINTS WILL CREATE ENOUGH SBCAPE IN THE 2000-2500 J/KG
RANGE SOUTH CENTRAL KANSAS. FORECAST SOUNDINGS SHOW CONSIDERABLE CINH
REMAINING ACROSS SC KS THROUGH MUCH OF THE DAY AND THEN FINALLY ERODING
BY TONIGHT. 0 TO 6 KM SHEAR OF AROUND 30 KT COULD SUPPORT THE NOTION
FOR MORE ORGANIZED CONVECTION ACROSS SE BARBER COUNTY. WILL HIGHLIGHT
THESE CONCERNS IN THE HWO. OTHER INFORMATION REGARDING CONVECTION CAN
BE FOUND IN THE SWODY1 PRODUCT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 328 AM CDT THU MAR 29 2012
A WEAK AREA OF HIGH PRESSURE WILL BUILD INTO WESTERN KANSAS EARLY
FRIDAY AS A COLD FRONT SINKS SOUTH INTO OKLAHOMA. THIS FRONT WILL
BECOME STATIONARY BY MID DAY AS AN UPPER LEVEL DISTURBANCE
EMBEDDED IN THE WEST NORTHWEST FLOW CROSSES INTO WESTERN KANSAS.
BOTH THE NAM AND GFS PLACES THE BETTER LATE DAY INSTABILITY
NEAR/JUST SOUTH OF THE OKLAHOMA BORDER WHICH IS ALSO WHERE THE
BETTER 850MB WARM AIR ADVECTION/ISENTROPIC LIFT IS FORECAST TO
IMPROVE AHEAD OF THIS UPPER WAVE. BASED ON THE LIFT,MOISTURE AND
INSTABILITY AT 00Z SATURDAY AHEAD OF AN UPPER LEVEL DISTURBANCE
WILL CONTINUE TO LEAN TOWARDS A DRY FORECAST FOR SOUTHWEST KANSAS.
DID HOWEVER KEEP THE 12 TO NEAR 15 PERCENT CHANCE OF PRECIPITATION
IN THE MEDICINE LODGE AND COLDWATER AREAS BASED ON HOW CLOSE THESE
LOCATIONS WILL BE TO THE MOISTURE/LIFT NORTH OF THE STATIONARY
FRONT EARLY FRIDAY NIGHT.
AS FOR TEMPERATURES...BASED ON 850MB TEMPERATURES AT 00Z SATURDAY
THE PREVIOUS FORECAST STILL LOOKS ON TRACK FOR HIGHS FRIDAY
AFTERNOON. DID HOWEVER LOWER TEMPERATURES IN SOUTHWEST KANSAS NEAR
THE OKLAHOMA BORDER BY A FEW DEGREES GIVEN THE BETTER CHANCES FOR
MORE CLOUD COVER IN THIS LOCATION FRIDAY AFTERNOON.
ONCE THIS SYSTEM MOVES EAST OF WESTERN KANSAS FRIDAY NIGHT A
WESTERLY DOWNSLOPE FLOW WILL THEN BEGIN TO DEVELOP. 24 HOUR 850MB
TEMPERATURE TRENDS OVER THE WEEKEND PERIOD SUPPORTS A NICE WARM
UP. 80S WILL BE LIKELY BOTH DAYS. A FEW LOCATIONS MAY EVEN
APPROACH 90 DEGREES ALONG AND SOUTH OF DODGE CITY IF THE 00Z
MONDAY 850MB TEMPERATURES FROM THE GFS AND ECMWF VERIFIES.
ON SUNDAY IT WILL ALSO BE WINDY AS A TIGHT SURFACE PRESSURE GRADIENT
DEVELOPS ACROSS WESTERN KANSAS IN RESPONSE TO AN AREA OF LOW
PRESSURE DEEPENING ALONG THE LEE OF THE ROCKIES. THIS DEEPENING
SURFACE LOW WILL THEN SLIDE EAST INTO WESTERN KANSAS SUNDAY NIGHT
AS AN UPPER LEVEL TROUGH EXITS THE ROCKIES AND MOVES OUT INTO THE
CENTRAL PLAINS. AN ELEVATED MIXED LAYER SHOULD INHIBIT
PRECIPITATION CHANCES ON SUNDAY AHEAD OF THIS NEXT SYSTEM. DRY AIR
MIXING DOWN TO THE SURFACE WILL INCREASE THE FIRE DANGER LEVELS
ACROSS WESTERN KANSAS...ESPECIALLY WEST OF THE DRY LINE.
A COLD FRONT WILL MOVE ACROSS WESTERN KANSAS EARLY MONDAY AS THIS
UPPER LEVEL TROUGH CROSSES INTO THE CENTRAL PLAINS. THE GFS
SUGGESTS SOME IMPROVING MID LEVEL INSTABILITY AS THE UPPER LEVEL
TROUGH CROSSES WESTERN KANSAS DURING THE DAY. BASED ON WHERE THE
BETTER MOISTURE RETURN WILL BE AHEAD OF THIS SYSTEM HAVE DECIDED
TO STAY CLOSE TO THE ALLBLEND ON PRECIPITATION CHANCES. THIS WOULD
PLACE A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS PORTIONS OF NORTH
CENTRAL KANSAS. AS FOR TEMPERATURES HAVE DECIDED TO FOLLOW THE
GENERAL 925-850MB TEMPERATURE TRENDS FROM THE GFS AND ECMWF. THIS
WOULD FAVOR HIGHS MAINLY IN THE 60S ON MONDAY AS THIS UPPER LEVEL
TROUGH PASSES.
A WARMING TREND WILL RETURN BY MID WEEK AS AN UPPER LEVEL RIDGE
CROSSES THE ROCKIES AND A WESTERLY DOWNSLOPE FLOW IMPROVES ACROSS
EASTERN COLORADO AND WESTERN KANSAS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 606 AM CDT THU MAR 29 2012
10Z SURFACE ANALYSIS CONTINUES TO SUPPORT THE 06Z NAM AND 08Z
HRRR IN PLACING THE BETTER OPPORTUNITY FOR LIFR FOG/STATUS ACROSS
NORTH CENTRAL KANSAS, NEAR HAYS, EARLY THIS MORNING WHERE A MOIST
UPSLOPE FLOW CONTINUES. AS A RESULT WILL KEEP LIFR CIGS/VSBYS GOING
FOR THE NEXT FEW HOURS. FURTHER SOUTH AT GCK AND DDC A GUSTY
SOUTHWEST WIND HAD ALREADY DEVELOPS WITH LOWER DEWPOINTS NOW BEING
ADVECTED INTO THIS REGION SO VFR CONDITIONS ARE EXPECTED. MET AND
HRRR WERE IN DECENT AGREEMENT WITH TIMING OF THE NORTHWEST WINDS
DEVELOPING DURING THE EARLY AFTERNOON AS A WEAK COLD FRONT CROSSES
WESTERN KANSAS SO WILL STAY CLOSE TO MET TIMING OF THE WIND SHIFT
LATER TODAY.
&&
.FIRE WEATHER...
ISSUED AT 328 AM CDT THU MAR 29 2012
GUSTY SOUTHWEST WINDS WILL DEVELOP ON SUNDAY AS AN AREA OF LOW
PRESSURE DEEPENS ACROSS NORTHEAST COLORADO. SUSTAINED WINDS OF 20 TO
30 MPH WILL BE LIKELY. IN ADDITION AFTERNOON RELATIVE HUMIDITIES
ARE EXPECTED TO FALL BACK INTO THE TEENS WEST OF A DRYLINE WHICH
CURRENTLY IS EXPECTED TO EXTEND FROM NEAR SCOTT CITY TO GARDEN
CITY TO NEAR LIBERAL. THIS COMBINATION WILL RESULT IN VERY HIGH TO
CRITICAL FIRE WEATHER CONDITIONS ACROSS PORTIONS OF WESTERN KANSAS
SUNDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 83 48 78 51 / 10 10 10 10
GCK 82 47 77 51 / 0 10 10 10
EHA 81 46 76 51 / 0 10 10 10
LBL 85 47 77 49 / 0 10 10 10
HYS 79 47 79 50 / 0 10 10 10
P28 84 53 80 56 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR KSZ030-031-
043>046.
&&
$$
UPDATE...BURGERT
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
608 AM CDT THU MAR 29 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 217 AM CDT THU MAR 29 2012
.SYNOPSIS...
ISSUED AT 217 AM CDT THU MAR 29 2012
00Z 300 HPA SYNOPTIC MAP ANALYSIS SHOWS A 95 KT JET PUSHING ASHORE ACROSS
THE PACIFIC NORTHWEST IN ASSOCIATION WITH BROAD TROUGH EXTENDING FROM
THE PACNW TO THE NORTHERN ROCKIES. WEAKER 50 TO 75 KT BROAD W/NW FLOW
EXTENDED ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION.
THE 500 HPA FLOW PATTERN SHOWED THE TROUGH AXIS IN ASSOCIATION WITH
THE AFOREMENTIONED JET STREAK FROM THE NORTHEAST PACIFIC AND SE ACROSS
THE GREAT BASIN. LOWER IN THE ATMOSPHERE...NAMELY THROUGH THE 700 AND
850 HPA LAYERS, THE MOST INTERESTING ITEM WAS WARM AND DRY FLOW IN
THE LEE OF THE ROCKIES. AT THE SFC, MSAS SURFACE PRESSURE ANALYSIS SHOWED
A WEAK LOW PRESSURE CENTER ACROSS SE COLORADO. A WARM FRONT WAS EXTENDING
FROM THIS FEATURE ACROSS CENTRAL KANSAS. RICH MOISTURE AS MARKED BY
DEWPOINTS IN THE 60S DEG F EXTENDED ACROSS SOUTH CENTRAL KANSAS.
THIS MORNING:
THE MAIN ITEM OF CONCERN DURING THE MORNING PERIOD IS THE LIKELIHOOD
FOR DENSE FOG. HRRR AND MOS IS SUGGESTING THE GREATEST POTENTIAL FOR
DENSE FOG ACROSS WEST CENTRAL KANSAS THIS MORNING. THIS IS ALSO REFLECTED
IN 00Z NAM BUFKIT DATA. THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE
DEWPOINTS (LOW 50S DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A
WARM FRONT THAT WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
TODAY:
THE FOG SHOULD DISSIPATE/MIX OUT BY MID MORNING. THE REST OF THE SENSIBLE
WEATHER FOR TODAY WILL BE FAIRLY TRANQUIL. A BROAD UPPER LEVEL SHORTWAVE
TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS TODAY. SW KANSAS WILL BE
ON THE SOUTHEASTERN FRIDGES OF THE 400 HPA PV ANOMALY TODAY. AS A RESULT
OF THE AFOREMENTIONED UPPER LEVEL DYNAMICS SLIDING EAST THROUGH THE
DAY, THE RESULTANT SURFACE LOW WILL CONTINUE TO SLIDE TO THE EAST ACROSS
NORTHERN KANSAS AS WELL. A BIT OF DOWNSLOPE AND MIXING ACROSS THE SOUTHWESTERN
COUNTIES THIS AFTERNOON WILL PROVIDE VERY WARM TEMPERATURES NEAR THE
OKLAHOMA BORDER. EXPECT MID 80S DEG F IN THIS AREA. FURTHER NORTH, ONLY
LOOKING FOR UPPER 70S DEG F TO AROUND 80 DEG F AS A WEAK COLD FRONT
MOVES THROUGH EARLIER IN THE DAY. THE DRYLINE WITH UPPER 50S TO LOWER
60S DEG F DEWPOINTS WILL MIX EAST TODAY. THIS DRYLINE SHOULD BE LOCATED
ACROSS SOUTH CENTRAL KANSAS BY THIS AFTERNOON.
TONIGHT:
EVENTUALLY THE PACIFIC FRONT FOLLOWING BEHIND THE DRYLINE WILL CATCH
UP CLOSER TO THE DRYLINE. HAVE DISCOUNTED THE 00Z GFS SOLUTION AS THIS
MODEL SEEMS TO BE SUFFERING FROM BOUNDARY LAYER MOISTURE PROBLEMS AND
THE RESULTANT QPF LOOKS A LITTLE OVERZEALOUS. MAINLY STUCK WITH THE
00Z NAM AND 00Z WRF-NMM FOR POPS THIS EVENING. CONFINED POPS MAINLY ACROSS
SOUTH CENTRAL KANSAS AS TEMPERATURES IN THE 80S DEG F COMBINED WITH
NEAR 60 DEG F DEWPOINTS WILL CREATE ENOUGH SBCAPE IN THE 2000-2500 J/KG
RANGE SOUTH CENTRAL KANSAS. FORECAST SOUNDINGS SHOW CONSIDERABLE CINH
REMAINING ACROSS SC KS THROUGH MUCH OF THE DAY AND THEN FINALLY ERODING
BY TONIGHT. 0 TO 6 KM SHEAR OF AROUND 30 KT COULD SUPPORT THE NOTION
FOR MORE ORGANIZED CONVECTION ACROSS SE BARBER COUNTY. WILL HIGHLIGHT
THESE CONCERNS IN THE HWO. OTHER INFORMATION REGARDING CONVECTION CAN
BE FOUND IN THE SWODY1 PRODUCT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 328 AM CDT THU MAR 29 2012
A WEAK AREA OF HIGH PRESSURE WILL BUILD INTO WESTERN KANSAS EARLY
FRIDAY AS A COLD FRONT SINKS SOUTH INTO OKLAHOMA. THIS FRONT WILL
BECOME STATIONARY BY MID DAY AS AN UPPER LEVEL DISTURBANCE
EMBEDDED IN THE WEST NORTHWEST FLOW CROSSES INTO WESTERN KANSAS.
BOTH THE NAM AND GFS PLACES THE BETTER LATE DAY INSTABILITY
NEAR/JUST SOUTH OF THE OKLAHOMA BORDER WHICH IS ALSO WHERE THE
BETTER 850MB WARM AIR ADVECTION/ISENTROPIC LIFT IS FORECAST TO
IMPROVE AHEAD OF THIS UPPER WAVE. BASED ON THE LIFT,MOISTURE AND
INSTABILITY AT 00Z SATURDAY AHEAD OF AN UPPER LEVEL DISTURBANCE
WILL CONTINUE TO LEAN TOWARDS A DRY FORECAST FOR SOUTHWEST KANSAS.
DID HOWEVER KEEP THE 12 TO NEAR 15 PERCENT CHANCE OF PRECIPITATION
IN THE MEDICINE LODGE AND COLDWATER AREAS BASED ON HOW CLOSE THESE
LOCATIONS WILL BE TO THE MOISTURE/LIFT NORTH OF THE STATIONARY
FRONT EARLY FRIDAY NIGHT.
AS FOR TEMPERATURES...BASED ON 850MB TEMPERATURES AT 00Z SATURDAY
THE PREVIOUS FORECAST STILL LOOKS ON TRACK FOR HIGHS FRIDAY
AFTERNOON. DID HOWEVER LOWER TEMPERATURES IN SOUTHWEST KANSAS NEAR
THE OKLAHOMA BORDER BY A FEW DEGREES GIVEN THE BETTER CHANCES FOR
MORE CLOUD COVER IN THIS LOCATION FRIDAY AFTERNOON.
ONCE THIS SYSTEM MOVES EAST OF WESTERN KANSAS FRIDAY NIGHT A
WESTERLY DOWNSLOPE FLOW WILL THEN BEGIN TO DEVELOP. 24 HOUR 850MB
TEMPERATURE TRENDS OVER THE WEEKEND PERIOD SUPPORTS A NICE WARM
UP. 80S WILL BE LIKELY BOTH DAYS. A FEW LOCATIONS MAY EVEN
APPROACH 90 DEGREES ALONG AND SOUTH OF DODGE CITY IF THE 00Z
MONDAY 850MB TEMPERATURES FROM THE GFS AND ECMWF VERIFIES.
ON SUNDAY IT WILL ALSO BE WINDY AS A TIGHT SURFACE PRESSURE GRADIENT
DEVELOPS ACROSS WESTERN KANSAS IN RESPONSE TO AN AREA OF LOW
PRESSURE DEEPENING ALONG THE LEE OF THE ROCKIES. THIS DEEPENING
SURFACE LOW WILL THEN SLIDE EAST INTO WESTERN KANSAS SUNDAY NIGHT
AS AN UPPER LEVEL TROUGH EXITS THE ROCKIES AND MOVES OUT INTO THE
CENTRAL PLAINS. AN ELEVATED MIXED LAYER SHOULD INHIBIT
PRECIPITATION CHANCES ON SUNDAY AHEAD OF THIS NEXT SYSTEM. DRY AIR
MIXING DOWN TO THE SURFACE WILL INCREASE THE FIRE DANGER LEVELS
ACROSS WESTERN KANSAS...ESPECIALLY WEST OF THE DRY LINE.
A COLD FRONT WILL MOVE ACROSS WESTERN KANSAS EARLY MONDAY AS THIS
UPPER LEVEL TROUGH CROSSES INTO THE CENTRAL PLAINS. THE GFS
SUGGESTS SOME IMPROVING MID LEVEL INSTABILITY AS THE UPPER LEVEL
TROUGH CROSSES WESTERN KANSAS DURING THE DAY. BASED ON WHERE THE
BETTER MOISTURE RETURN WILL BE AHEAD OF THIS SYSTEM HAVE DECIDED
TO STAY CLOSE TO THE ALLBLEND ON PRECIPITATION CHANCES. THIS WOULD
PLACE A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS PORTIONS OF NORTH
CENTRAL KANSAS. AS FOR TEMPERATURES HAVE DECIDED TO FOLLOW THE
GENERAL 925-850MB TEMPERATURE TRENDS FROM THE GFS AND ECMWF. THIS
WOULD FAVOR HIGHS MAINLY IN THE 60S ON MONDAY AS THIS UPPER LEVEL
TROUGH PASSES.
A WARMING TREND WILL RETURN BY MID WEEK AS AN UPPER LEVEL RIDGE
CROSSES THE ROCKIES AND A WESTERLY DOWNSLOPE FLOW IMPROVES ACROSS
EASTERN COLORADO AND WESTERN KANSAS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 606 AM CDT THU MAR 29 2012
10Z SURFACE ANALYSIS CONTINUES TO SUPPORT THE 06Z NAM AND 08Z
HRRR IN PLACING THE BETTER OPPORTUNITY FOR LIFR FOG/STATUS ACROSS
NORTH CENTRAL KANSAS, NEAR HAYS, EARLY THIS MORNING WHERE A MOIST
UPSLOPE FLOW CONTINUES. AS A RESULT WILL KEEP LIFR CIGS/VSBYS GOING
FOR THE NEXT FEW HOURS. FURTHER SOUTH AT GCK AND DDC A GUSTY
SOUTHWEST WIND HAD ALREADY DEVELOPS WITH LOWER DEWPOINTS NOW BEING
ADVECTED INTO THIS REGION SO VFR CONDITIONS ARE EXPECTED. MET AND
HRRR WERE IN DECENT AGREEMENT WITH TIMING OF THE NORTHWEST WINDS
DEVELOPING DURING THE EARLY AFTERNOON AS A WEAK COLD FRONT CROSSES
WESTERN KANSAS SO WILL STAY CLOSE TO MET TIMING OF THE WIND SHIFT
LATER TODAY.
&&
.FIRE WEATHER...
ISSUED AT 328 AM CDT THU MAR 29 2012
GUSTY SOUTHWEST WINDS WILL DEVELOP ON SUNDAY AS AN AREA OF LOW
PRESSURE DEEPENS ACROSS NORTHEAST COLORADO. SUSTAINED WINDS OF 20 TO
30 MPH WILL BE LIKELY. IN ADDITION AFTERNOON RELATIVE HUMIDITIES
ARE EXPECTED TO FALL BACK INTO THE TEENS WEST OF A DRYLINE WHICH
CURRENTLY IS EXPECTED TO EXTEND FROM NEAR SCOTT CITY TO GARDEN
CITY TO NEAR LIBERAL. THIS COMBINATION WILL RESULT IN VERY HIGH TO
CRITICAL FIRE WEATHER CONDITIONS ACROSS PORTIONS OF WESTERN KANSAS
SUNDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 83 48 78 51 / 10 10 10 10
GCK 82 47 77 51 / 0 10 10 10
EHA 81 46 76 51 / 0 10 10 10
LBL 85 47 77 49 / 0 10 10 10
HYS 79 47 79 50 / 0 10 10 10
P28 84 53 80 56 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR KSZ030-031-
043>046.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1010 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD TODAY AND PROVIDE DRY...BUT COOLER
WEATHER. RAIN CHANCES ARE SET TO INCREASE ON FRIDAY AS LOW
PRESSURE CROSSES THE REGION. WEEKEND WEATHER WILL FEATURE
ONLY LOW PRECIPITATION CHANCES AND MODERATING TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
A MID-MORNING UPDATE HAS BEEN ISSUED IN ORDER TO ACCOUNT FOR THE
LATEST TRENDS IN SKY COVERAGE.
A COLD NORTHWESTERLY FLOW WILL CONTINUE TO ALLOW FOR STRATOCUMULUS
TO FILTER ACROSS AREAS MOSTLY EAST OF I-77 THROUGH THE EARLY
AFTERNOON. MOISTURE WILL BEGIN TO PULL EAST OF THE AREA AND ERODE
WITH BREAKS EARLY THIS AFTERNOON AND CLEARING FROM THE SOUTHWEST
BY LATE AFTERNOON. CLOUD COVERAGE WILL KEEP TEMPS DOWN TODAY.
HIGHS TODAY WILL RANGE FROM THE MID 40S ALONG THE I-80 CORRIDOR
AND EASTERN RIDGES TO THE UPPER 50S WITH MORE SUNSHINE IN PORTIONS
OF EASTERN OHIO.
WITH DIMINISHED WIND AND CLOUD COVER TONIGHT...RADIATIONAL COOLING
WILL RAPIDLY COMMENCE WITH TEMPERATURES FALLING INTO THE 30S
ACROSS THE ENTIRE AREA BY FRIDAY MORNING...AND UPPER 20S ARE
PROJECTED OVER THE RIDGE ZONES AND OVER COUNTIES NORTH OF
PITTSBURGH.
WARM...MOIST ADVECTION/MID LEVEL CLOUDINESS IN ADVANCE OF MIDWRN
LOW PRESSURE ARE CURRENTLY PROJECTED TO ARRIVE AT AROUND
DAYBREAK...TOO LATE TO PRECLUDE AREAS OF FROST FOR ALL ZONES.
FREEZE WARNING WAS ISSUED FOR THE NORTHEASTERN HALF OF THE COUNTY
WARNING AREA...WHERE SURFACE RIDGE AXIS WILL CROSS AND WHERE
DRIER AIR WILL SETTLE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AFOREMENTIONED MIDWRN LOW PRES LOOKS TO APPROACH THE AREA ON
FRIDAY...WITH PASSAGE PROJECTED FOR FRIDAY NIGHT...AND SYSTEM EXIT
ON SATURDAY. HAVE GENERALLY PERSISTED WITH PREVIOUS
FORECAST...BUT WITH ADJUSTMENTS TO TIMING AS PER LATEST
DETERMINISTIC MODEL TRENDS. HAVE ALSO INCLUDED A THUNDER MENTION
FOR THE SOUTHERN ZONES ON FRIDAY AFTERNOON GIVEN THE INSTABILITY
PROGNOSIS AND LOW PRESSURE TRACK.
BY SUNDAY...TEMPERATURE MODERATION IS FORECAST TO BE UNDERWAY AS
GREAT LAKES RIDGE AMPLIFIES...BUT SHORTWAVE IN NORTHWEST FLOW MAY
SPAWN SOME SHOWERS GIVEN LATEST MODEL SOLUTIONS. HAVE DECIDED TO
ENTER A SLIGHT CHANCE FOR NOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE NEXT LOW WILL TRACK FROM THE UPPER MS VALLEY INTO SOUTHERN
ONTARIO AND WILL PUSH A COLD FRONT THROUGH THE OHIO VALLEY
TUESDAY. SCATTERED SHOWERS SHOULD ACCOMPANY THIS SYSTEM TUESDAY
INTO EARLY WEDNESDAY.
TEMPERATURES ARE FORECAST TO RANGE BETWEEN 10 AND 15 DEGREES ABOVE
NORMAL THROUGH TUESDAY...WITH A RETURN TO NEAR NORMAL READINGS BY
WEDNESDAY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
RECENT SURFACE AND SATELLITE DATA, COUPLED WITH HRRR AND NAM MODEL
OUTPUT, SHOW COLD POOL MVFR STRATOCUMULUS EXPANDING SOUTHWARD ACROSS
THE UPPER OHIO VALLEY THROUGH 12Z. DAYTIME HEATING WILL INDUCE
VERTICAL MIXING TO CAUSE CLOUD CEILINGS TO LIFT THIS MORNING AND
THEN DISSIPATE, SOUTH TO NORTH, THIS AFTERNOON. EXPECT VFR WITH
MOSTLY CLEAR SKIES TONIGHT.
SURFACE WINDS WILL BE NORTHWEST 10-15 KTS TODAY AND BECOME LIGHT
TONIGHT.
OUTLOOK...FRIDAY THROUGH MONDAY...
RESTRICTIONS ARE POSSIBLE FRIDAY AFTERNOON INTO SATURDAY DUE TO
SHOWERS AND LOW CLOUDS ASSOCIATED WITH PASSING EASTBOUND LOW
PRESSURE SYSTEM. EXPECT MAINLY VFR SUNDAY AND MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR MDZ001.
OH...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR OHZ041.
PA...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR PAZ007>009-
013>016-020>023-029-073>076.
WV...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
639 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD TODAY AND PROVIDE DRY...BUT COOLER
WEATHER. RAIN CHANCES ARE SET TO INCREASE ON FRIDAY AS LOW
PRESSURE CROSSES THE REGION. WEEKEND WEATHER WILL FEATURE
ONLY LOW PRECIPITATION CHANCES AND MODERATING TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
630AM UPDATE. ONLY MINOR CHANGES TO REFLECT CURRENT CONDITIONS.
BRISK WINDS DURING THE DAY AND STRATOCU WILL ERODE BY LATE DAY AS
SURFACE RIDGE AXIS SLIDES OVER THE AREA.
TONIGHT WITH DIMINISHED WIND AND CLOUD COVER...RADIATIONAL
COOLING WILL RAPIDLY COMMENCE WITH TEMPERATURES FALLING INTO THE
30S ACROSS THE ENTIRE AREA BY FRIDAY MORNING...AND UPPER 20S ARE
PROJECTED OVER THE RIDGE ZONES AND OVER COUNTIES NORTH OF
PITTSBURGH.
WARM...MOIST ADVECTION/MID LEVEL CLOUDINESS IN ADVANCE OF MIDWRN
LOW PRESSURE ARE CURRENTLY PROJECTED TO ARRIVE AT AROUND
DAYBREAK...TOO LATE TO PRECLUDE AREAS OF FROST FOR ALL ZONES.
FREEZE WARNING WAS ISSUED FOR THE NORTHEASTERN HALF OF THE COUNTY
WARNING AREA...WHERE SURFACE RIDGE AXIS WILL CROSS AND WHERE
DRIER AIR WILL SETTLE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AFOREMENTIONED MIDWRN LOW PRES LOOKS TO APPROACH THE AREA ON
FRIDAY...WITH PASSAGE PROJECTED FOR FRIDAY NIGHT...AND SYSTEM EXIT
ON SATURDAY. HAVE GENERALLY PERSISTED WITH PREVIOUS
FORECAST...BUT WITH ADJUSTMENTS TO TIMING AS PER LATEST
DETERMINISTIC MODEL TRENDS. HAVE ALSO INCLUDED A THUNDER MENTION
FOR THE SOUTHERN ZONES ON FRIDAY AFTERNOON GIVEN THE INSTABILITY
PROGNOSIS AND LOW PRESSURE TRACK.
BY SUNDAY...TEMPERATURE MODERATION IS FORECAST TO BE UNDERWAY AS
GREAT LAKES RIDGE AMPLIFIES...BUT SHORTWAVE IN NORTHWEST FLOW MAY
SPAWN SOME SHOWERS GIVEN LATEST MODEL SOLUTIONS. HAVE DECIDED TO
ENTER A SLIGHT CHANCE FOR NOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE NEXT LOW WILL TRACK FROM THE UPPER MS VALLEY INTO SOUTHERN
ONTARIO AND WILL PUSH A COLD FRONT THROUGH THE OHIO VALLEY
TUESDAY. SCATTERED SHOWERS SHOULD ACCOMPANY THIS SYSTEM TUESDAY
INTO EARLY WEDNESDAY.
TEMPERATURES ARE FORECAST TO RANGE BETWEEN 10 AND 15 DEGREES ABOVE
NORMAL THROUGH TUESDAY...WITH A RETURN TO NEAR NORMAL READINGS BY
WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
RECENT SURFACE AND SATELLITE DATA, COUPLED WITH HRRR AND NAM MODEL
OUTPUT, SHOW COLD POOL MVFR STRATOCUMULUS EXPANDING SOUTHWARD ACROSS
THE UPPER OHIO VALLEY THROUGH 12Z. DAYTIME HEATING WILL INDUCE
VERTICAL MIXING TO CAUSE CLOUD CEILINGS TO LIFT THIS MORNING AND
THEN DISSIPATE, SOUTH TO NORTH, THIS AFTERNOON. EXPECT VFR WITH
MOSTLY CLEAR SKIES TONIGHT.
SURFACE WINDS WILL BE NORTHWEST 10-15 KTS TODAY AND BECOME LIGHT
TONIGHT.
OUTLOOK...FRIDAY THROUGH MONDAY...
RESTRICTIONS ARE POSSIBLE FRIDAY AFTERNOON INTO SATURDAY DUE TO
SHOWERS AND LOW CLOUDS ASSOCIATED WITH PASSING EASTBOUND LOW
PRESSURE SYSTEM. EXPECT MAINLY VFR SUNDAY AND MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR MDZ001.
OH...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR OHZ041.
PA...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR PAZ007>009-
013>016-020>023-029-073>076.
WV...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
624 AM CDT THU MAR 29 2012
.DISCUSSION...
TEMPERATURES THIS MORNING ARE FINALLY NEAR NORMAL IN A FEW
AREAS ESPECIALLY OVER WEST CENTRAL WISCONSIN WHERE SOME UPPER 20S
TO LOW 30S WERE NOTED...COURTESY OF HIGH PRESSURE AND CLEAR SKIES.
FREEZE WARNING LOOKS GOOD THIS MORNING. ELSEWHERE....INCREASING
MID LEVEL CLOUDS OVER NORTH DAKOTA AND NORTHWEST MINNESOTA IN ZONE
OF DEVELOPING WARM ADVECTION AND MID LEVEL THETA E ADVECTION.
A FEW RETURNS SHOWING UP IN THE REGION BUT SATURATION A FEW HOURS
AWAY YET. THE 06Z RUC SEEMS TO HAVE A DECENT TREND ON THE
INCREASING FGEN FORCING THIS MORNING FOR WEST CENTRAL MINNESOTA.
LOW LOWER LEVEL MOISTURE TRANSPORT STILL BOTTLED UP OVER THE
CENTRAL PLAINS. HAVE DELAYED POPS A BIT TODAY UNTIL THE WAVE OVER
EASTERN ID AND WESTERN WY GETS CLOSER ALONG WITH SOME OF THE
MOISTURE TRANSPORT REACHING IOWA. THE GFS AND NAM BOTH SHOW
PRECIPITABLE WATER VALUES REACHING JUST OVER AN INCH BY 00Z AT MSP
WHICH IS NEAR 2 STANDARD DEVIATIONS ABOVE NORMAL. HAVE RAISED POPS
BY EVENING INTO THE CATEGORICAL AREA OVER AT LEAST THE CENTRAL CWA
AND THEN FARTHER EAST INTO WISCONSIN LATER IN THE EVENING. THE GFS
IS A LITTLE FASTER WITH THE WAVE BUT NOT BY MUCH. MOST LINGERING
PRECIP SHOULD BE CONFINED TO A FEW AREAS OF WEST CENTRAL WISCONSIN
BY FRIDAY MORNING. BEST CHANCE OF ISOLATED THUNDER OVER WEST
CENTRAL MN THIS MORNING INTO THE AFTERNOON WITH THE INITIAL BURST
OF WARM ADVECTION AND THEN MAINLY SOUTHERN HALF OF THE CWA IN THE
AFTERNOON AND EVENING NEAR THE EDGE OF THE DEEPER INSTABILITY
TO UR SOUTH.
LOOKS LIKE LINGERING CLOUDS EASTERN AREAS FRIDAY INTO SATURDAY
MORNING WITH THE DEVELOPING STRONGER WARM FRONT. A LITTLE
CONCERNED ABOUT A FEW SHOWERS DEVELOPING LATER FRIDAY NIGHT AND
SATURDAY MORNING NEAR THE FRONT. WILL LEAVE OUT FOR NOW WITH THE
INITIAL DRIER BEHIND THE DEPARTING WAVE LATER TONIGHT.
STILL LOOKS WARM FOR THE WEEKEND...ESPECIALLY SUNDAY DEEP INTO THE
WARM SECTOR. MIXING DOWN FROM AROUND 875-900MB EVEN YIELDS SOME
LOWER 80S ON THE SOUTH. CHANCES FOR TSTMS LOOK SLIM WITH A CAPPED
ENVIRONMENT INITIALLY BUT SUNDAY NIGHT LOOKS BETTER EASTERN AREAS.
&&
.AVIATION.../12Z TAF ISSUANCE/
MAIN AVIATION CONCERN IS TIMING OF INITIAL CONVECTION ACROSS
WESTERN MN...AND HOW IT TRANSLATES TO THE EAST THIS EVENING
OVERNIGHT.
THE FIRST 6-9 HRS SHOULD BE VFR ALONG WITH INCREASING E/SE WNDS.
CIGS WILL REMAIN AOA 6K. AFT 18-21Z...EXPECT SHRA AND EMBEDDED
TSRA TO DEVELOP NEAR AXN/RWF WITH TEMPORARY MVFR CIGS/VSBYS. THESE
CONDITIONS WILL OCCUR AT STC AFT 00Z...AND AT RNH/MSP BETWEEN
01-03Z. THERE SHOULD BE A PERIOD OF LIGHT TO MODERATE SHRA ALONG
WITH CIGS AVERAGING ARND 2-3K. VSBYS WILL ONLY LOWER IN HEAVIER
SHRA. AFT 3Z...MOST OF THE SHRA SHOULD MOVE EAST OF RWF/AXN WITH
CIGS DROPPING TO IFR. WNDS WILL REMAIN FROM THE SE THRU 00Z...THEN
DECREASE AND BECOME MORE W/NW AFT 3-6Z. TIMING IS THE MOST
IMPORTANT FACTOR IN THIS TAF PERIOD AS UPDATES WILL BE LIKELY AS
SHRA/TSRA DEVELOP.
MSP...VFR CONDITIONS ALONG WITH INCREASING ESE/SE WNDS DURING THE
MORNING. GUSTS UP TO 24 KTS POSSIBLE AFT 18Z...BEFORE DECREASING
DURING THE EVENING AND BECOMING MORE E...THEN NW TOWARD 12Z. MOST
OF THE SHRA/TSRA SHOULD HOLD OFF UNTIL AFT 01Z...WITH A PERIOD
BETWEEN 3-9Z WITH LIGHT TO MODERATE SHRA/TSRA. WILL CONTINUE CB/S
AS TIMING WHEN TSRA DEVELOP IS PROBLEMATIC. EVEN A TEMPORARY IS
NOT NECESSARY AT THIS TIME. LATER SHIFTS CAN PINPOINT THE 1-2 HR
PERIOD WHERE TSRA MOVE ACROSS THE AIRPORT THIS EVENING. CIGS WILL
LIKELY DROP TO MVFR ONCE THE HEAVIER SHRA DEVELOP...WITH IFR CIGS
BY 12Z.
.FRI MORNING...IFR/MVFR CIGS. VFR BY AFTN.
.SAT MORNING...BR/FG POSSIBLE. OTHERWISE VFR.
.SUN.VFR.
.MON...MVFR SHRA/TSRA.
.JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR BARRON-CHIPPEWA-
DUNN-EAU CLAIRE-POLK-RUSK.
&&
$$
JPR/JLT
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1043 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE PASSES TO THE NORTH LATE TODAY. LOW PRESSURE BRINGS
A WARM FRONT...THEN A COLD FRONT FRIDAY...THE LATTER WITH MORE
STORMS LATE FRIDAY. HIGH PRESSURE CROSSES SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE...BUMPED UP SKY COVER ACROSS ROUGHLY NORTHERN THIRD
OF FORECAST AREA. LOW-LEVEL STRATOCU OVER NORTHEAST OHIO CURRENTLY
PUSHING SOUTHWARD...ALONG WITH SOME LOW-LEVEL CU FORMING ACROSS NW
ZONES WARRANTED A BUMP IN SKY COVER TO MOSTLY SUNNY/PARTLY CLOUDY
PERHAPS DURING THE MID/LATE MORNING HOURS. THESE CLOUDS SHOULD
DISSIPATE DURING THE AFTERNOON HOURS. OTHERWISE...NO SIGNIFICANT
CHANGES MADE.
PREVIOUS DISCUSSION...LATEST IR IMAGERY HAS CLEAR SKY FOR ENTIRE CWA
CURRENTLY. HOWEVER...LOW LEVEL MOISTURE ASSOCIATED WITH THE POST-FRONTAL
TROF TO OUR NORTH IS OOZING SOUTHWARD AND SHOULD BEGIN TO POOL UP AGAINST
THE NRN WV MOUNTAINS EVENTUALLY DEVELOPING OROGRAPHICALLY INDUCED CLOUDS
AND NOTHING MORE.
CURRENT WV IMAGERY SHOWING COPIOUS DRY AIR DIRECTLY OVER OUR
AREA...AND THIS IS HANDLED WELL IN THE RUC H5-H7 LAYER.
THIS...COMBINED WITH MORNING DAYTIME HEATING...SHOULD WORK TO
QUICKLY DISSIPATE THE LOW LEVEL CLOUDS THAT ARE CONTINUING TO
DEVELOP IN THE NRN WV MNTS CURRENTLY. OVERALL...A PLEASANT DAY IS ON
TAP WITH CLEAR SKY CONDITIONS AND TEMPERATURES RETURNING A LITTLE
CLOSER TO SEASONAL AVERAGE.
CLEAR SKY AND MODEST CAA EARLY TONIGHT WILL WORK TO BRING
TEMPERATURES DOWN IN THE NRN ZONES NEARING THE POINT OF FROST
DEVELOPMENT. AT THE SAME TIME...NEAR TERM MODELS HAVE BEEN SPEEDING
UP THE TIMING OF THE APPROACH OF THE NEXT WARM FRONT. 06Z NAM AND
03Z SREF MEAN HAS THETA-E GRADIENT EAST OF THE TUG FORK VALLEY AND
THE TRI-STATE AREA BY 12Z FRI. WITH THIS IN MIND...WILL NOT BE
ISSUING FROST ADVY FOR NRN ZONES WITH THIS ISSUANCE...BUT WILL
MENTION POSSIBILITY FOR PATCHY FROST IN WX GRIDS AND ZONES.
FOR REASONS MENTIONED ABOVE...HAVE SPED UP TIMING OF THE ONSET OF
CLOUD COVER AND POPS ASSOCIATED WITH WARM FRONT TOWARDS THE END OF
THE NEAR TERM. BY MID-DAY FRI...CWA SHOULD BE FIRMLY PLANTED IN THE
WARM SECTOR WITH TEMPS REBOUNDING QUICKLY.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
SHIFTED SAT SYSTEM TO FRI YESTERDAY...RESULTING IN AN ENTIRELY DRY
WEEKEND. NOW IT LOOKS LIKE WE MAY BE TAKING BACK SUNDAY.
FRI SYSTEM REMAINS ON TRACK AS EVEN ECMWF HAS COME AROUND TO THE
FASTER TIMING. NW-SE ORIENTED WARM FRONT...THEN THE WARM
SECTOR...THEN NE-SW ORIENTED COLD FRONT MARCH ACROSS IN A NICE
CLASSICAL SYNOPTIC SETUP. WORRIED PRECIPITATION COULD BREAK OUT
ALONG THE WARM FRONT FRI MORNING...WHICH IS MARKED BY WELL DEFINED
THETA E GRADIENT. WE COULD EVEN SEE A CONVECTIVE COMPLEX SIMILAR TO
WHAT IS GOING ON THIS MORNING OVER THE MIDWEST ALONG SAID GRADIENT.
AFTER A BREAK IN THE WARM SECTOR EARLY FRI AFTERNOON...SHOWERS AND
STRONG THUNDERSTORMS FIRE UP AHEAD OF THE COLD FRONT LATE FRI
AFTERNOON AND TRAVERSE THE AREA FROM NW TO SE THROUGH FRI EVENING.
THE THERMODYNAMIC AND KINEMATIC PARAMETERS LOOK SIMILAR TO THOSE
AHEAD OF THE COLD FRONT THAT TRAVERSED THE AREA LAST NIGHT...SO A
SIMILAR HAIL AND WIND THREAT IS ANTICIPATED. INSTABILITY LOOKS TO
BE GREATEST AS ONE MOVES SW ALONG FRONT...CLOSE TO MOISTURE SOURCE.
INDEED...SPC CONTINUES TO PEG WESTERN PORTIONS OF THE AREA FOR THE
SLIGHT RISK.
WILL KEEP HWO HAZARD AND RWS IMPACT FOR SEVERE THUNDERSTORMS
EMPHASIZING THE W.
COLD ADVECTION IN THE WAKE OF THE SYSTEM SAT WILL BE ACCOMPANIED BY
DEEPER MOISTURE COMPARED WITH TODAY...ALONG WITH SOME SUB FREEZING
LOW LEVEL TEMPERATURES...SO OPTED TO LEAVE SHOWER CHANCE IN THE
MOUNTAINS. ALSO LOTS OF STRATOCU ATOP MIXED LAYER THROUGHOUT THE
AREA.
THE CONUNDRUM SUNDAY IS A NW FLOW WARM ADVECTION FEATURE THAT MAY
AGAIN MATERIALIZE AS A CONVECTIVE COMPLEX. FOR NOW...JUST ADDED THE
SLIGHT CHANCE FOR SHOWERS IN CONCERT WITH NEIGHBORS TO THE N AND W.
THANKS ILN AND PBZ FOR COORD ON THIS CHANGE. WOULD NOT BE SURPRISED
TO SEE THIS BLOW UP INTO SOMETHING MORE IF THE GENERAL PATTERN
EVOLUTION HOLDS.
USED A CACOPHONY OF GUIDANCE BLENDS TO ARRIVE AT TEMPERATURES.
TRIED TO RAISE HIGHS FRI IN THE WARM SECTOR...ESPECIALLY SOUTHERN
AND CENTRAL PORTIONS OF THE AREA. LOWERED A LITTLE FRI NT THROUGH
SAT NT ALTHOUGH NAM12 SUGGESTS IT WILL BE EVEN COLDER. TRENDED
TEMPERATURES UP JUST A BIT SUN AND SUN NT.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
STILL HAVE A DEGREE OF UNCERTAINTY TO THE EXTENDED...PER
USUAL...RESULTING IN A BLEND COMING FROM HPC IN THE FORECAST GRIDS.
DID ADJUST SOME OF THE SKIES DURING THE EXTENDED PERIOD TO BETTER
MATCH UP WITH THE POPS IN THE FORECAST. OVERALL...LOOKING AT MORE
SEASONAL TEMPERATURES...AND DESPITE A COUPLE OF SYSTEMS IN THE LONG
TERM MODELS...OVERALL PRECIPITATION TO COME IN ON THE LOWER SIDE. DO
HAVE A COUPLE OF NIGHTS TOWARDS THE END OF THE PERIOD WHERE WE MAY
NEED TO BE CAREFUL OF FROST AND FREEZE GIVEN THE TRENDS IN THAT TIME
PERIOD WITH A DEEP TROUGH LIFTING OUT AND THE SKY TRYING TO
CLEAR...BUT AS OF NOW...NOTHING TO BE MENTIONED IN THE HWO OR RWS.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
00Z THURSDAY THRU 00Z FRIDAY...
HIGH PRESSURE CURRENTLY BUILDING IN. GENERALLY VFR WITH MOSTLY CLEAR
CONDITIONS. LIGHT SURFACE FLOW OUT OF THE NORTH WILL BACK AROUND
TO THE SOUTH AND WEST TONIGHT. HIGH CLOUDS WILL BEGIN TO STREAM
IN TONIGHT AHEAD OF A WARM FRONT FOR FRIDAY...BUT VFR WILL REMAIN
THE PREVAILING CATEGORY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: NONE
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z FRIDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/TAX
NEAR TERM...50/TAX
SHORT TERM...TRM
LONG TERM...26
AVIATION...TAX
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
622 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE PASSES TO THE NORTH LATE TODAY. LOW PRESSURE BRINGS
A WARM FRONT...THEN A COLD FRONT FRIDAY...THE LATTER WITH MORE
STORMS LATE FRIDAY. HIGH PRESSURE CROSSES SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST IR IMAGERY HAS CLEAR SKY FOR ENTIRE CWA CURRENTLY.
HOWEVER...LOW LEVEL MOISTURE ASSOCIATED WITH THE POST-FRONTAL TROF
TO OUR NORTH IS OOZING SOUTHWARD AND SHOULD BEGIN TO POOL UP AGAINST
THE NRN WV MOUNTAINS EVENTUALLY DEVELOPING OROGRAPHICALLY INDUCED
CLOUDS AND NOTHING MORE.
CURRENT WV IMAGERY SHOWING COPIOUS DRY AIR DIRECTLY OVER OUR
AREA...AND THIS IS HANDLED WELL IN THE RUC H5-H7 LAYER.
THIS...COMBINED WITH MORNING DAYTIME HEATING...SHOULD WORK TO
QUICKLY DISSIPATE THE LOW LEVEL CLOUDS THAT ARE CONTINUING TO
DEVELOP IN THE NRN WV MNTS CURRENTLY. OVERALL...A PLEASANT DAY IS ON
TAP WITH CLEAR SKY CONDITIONS AND TEMPERATURES RETURNING A LITTLE
CLOSER TO SEASONAL AVERAGE.
CLEAR SKY AND MODEST CAA EARLY TONIGHT WILL WORK TO BRING
TEMPERATURES DOWN IN THE NRN ZONES NEARING THE POINT OF FROST
DEVELOPMENT. AT THE SAME TIME...NEAR TERM MODELS HAVE BEEN SPEEDING
UP THE TIMING OF THE APPROACH OF THE NEXT WARM FRONT. 06Z NAM AND
03Z SREF MEAN HAS THETA-E GRADIENT EAST OF THE TUG FORK VALLEY AND
THE TRI-STATE AREA BY 12Z FRI. WITH THIS IN MIND...WILL NOT BE
ISSUING FROST ADVY FOR NRN ZONES WITH THIS ISSUANCE...BUT WILL
MENTION POSSIBILITY FOR PATCHY FROST IN WX GRIDS AND ZONES.
FOR REASONS MENTIONED ABOVE...HAVE SPED UP TIMING OF THE ONSET OF
CLOUD COVER AND POPS ASSOCIATED WITH WARM FRONT TOWARDS THE END OF
THE NEAR TERM. BY MID-DAY FRI...CWA SHOULD BE FIRMLY PLANTED IN THE
WARM SECTOR WITH TEMPS REBOUNDING QUICKLY.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
SHIFTED SAT SYSTEM TO FRI YESTERDAY...RESULTING IN AN ENTIRELY DRY
WEEKEND. NOW IT LOOKS LIKE WE MAY BE TAKING BACK SUNDAY.
FRI SYSTEM REMAINS ON TRACK AS EVEN ECMWF HAS COME AROUND TO THE
FASTER TIMING. NW-SE ORIENTED WARM FRONT...THEN THE WARM
SECTOR...THEN NE-SW ORIENTED COLD FRONT MARCH ACROSS IN A NICE
CLASSICAL SYNOPTIC SETUP. WORRIED PRECIPITATION COULD BREAK OUT
ALONG THE WARM FRONT FRI MORNING...WHICH IS MARKED BY WELL DEFINED
THETA E GRADIENT. WE COULD EVEN SEE A CONVECTIVE COMPLEX SIMILAR TO
WHAT IS GOING ON THIS MORNING OVER THE MIDWEST ALONG SAID GRADIENT.
AFTER A BREAK IN THE WARM SECTOR EARLY FRI AFTERNOON...SHOWERS AND
STRONG THUNDERSTORMS FIRE UP AHEAD OF THE COLD FRONT LATE FRI
AFTERNOON AND TRAVERSE THE AREA FROM NW TO SE THROUGH FRI EVENING.
THE THERMODYNAMIC AND KINEMATIC PARAMETERS LOOK SIMILAR TO THOSE
AHEAD OF THE COLD FRONT THAT TRAVERSED THE AREA LAST NIGHT...SO A
SIMILAR HAIL AND WIND THREAT IS ANTICIPATED. INSTABILITY LOOKS TO
BE GREATEST AS ONE MOVES SW ALONG FRONT...CLOSE TO MOISTURE SOURCE.
INDEED...SPC CONTINUES TO PEG WESTERN PORTIONS OF THE AREA FOR THE
SLIGHT RISK.
WILL KEEP HWO HAZARD AND RWS IMPACT FOR SEVERE THUNDERSTORMS
EMPHASIZING THE W.
COLD ADVECTION IN THE WAKE OF THE SYSTEM SAT WILL BE ACCOMPANIED BY
DEEPER MOISTURE COMPARED WITH TODAY...ALONG WITH SOME SUB FREEZING
LOW LEVEL TEMPERATURES...SO OPTED TO LEAVE SHOWER CHANCE IN THE
MOUNTAINS. ALSO LOTS OF STRATOCU ATOP MIXED LAYER THROUGHOUT THE
AREA.
THE CONUNDRUM SUNDAY IS A NW FLOW WARM ADVECTION FEATURE THAT MAY
AGAIN MATERIALIZE AS A CONVECTIVE COMPLEX. FOR NOW...JUST ADDED THE
SLIGHT CHANCE FOR SHOWERS IN CONCERT WITH NEIGHBORS TO THE N AND W.
THANKS ILN AND PBZ FOR COORD ON THIS CHANGE. WOULD NOT BE SURPRISED
TO SEE THIS BLOW UP INTO SOMETHING MORE IF THE GENERAL PATTERN
EVOLUTION HOLDS.
USED A CACOPHONY OF GUIDANCE BLENDS TO ARRIVE AT TEMPERATURES.
TRIED TO RAISE HIGHS FRI IN THE WARM SECTOR...ESPECIALLY SOUTHERN
AND CENTRAL PORTIONS OF THE AREA. LOWERED A LITTLE FRI NT THROUGH
SAT NT ALTHOUGH NAM12 SUGGESTS IT WILL BE EVEN COLDER. TRENDED
TEMPERATURES UP JUST A BIT SUN AND SUN NT.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
STILL HAVE A DEGREE OF UNCERTAINTY TO THE EXTENDED...PER
USUAL...RESULTING IN A BLEND COMING FROM HPC IN THE FORECAST GRIDS.
DID ADJUST SOME OF THE SKIES DURING THE EXTENDED PERIOD TO BETTER
MATCH UP WITH THE POPS IN THE FORECAST. OVERALL...LOOKING AT MORE
SEASONAL TEMPERATURES...AND DESPITE A COUPLE OF SYSTEMS IN THE LONG
TERM MODELS...OVERALL PRECIPITATION TO COME IN ON THE LOWER SIDE. DO
HAVE A COUPLE OF NIGHTS TOWARDS THE END OF THE PERIOD WHERE WE MAY
NEED TO BE CAREFUL OF FROST AND FREEZE GIVEN THE TRENDS IN THAT TIME
PERIOD WITH A DEEP TROUGH LIFTING OUT AND THE SKY TRYING TO
CLEAR...BUT AS OF NOW...NOTHING TO BE MENTIONED IN THE HWO OR RWS.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
00Z THURSDAY THRU 00Z FRIDAY...
HIGH PRESSURE CURRENTLY BUILDING IN. GENERALLY VFR WITH MOSTLY CLEAR
CONDITIONS. LIGHT SURFACE FLOW OUT OF THE NORTH WILL BACK AROUND
TO THE SOUTH AND WEST TONIGHT. HIGH CLOUDS WILL BEGIN TO STREAM
IN TONIGHT AHEAD OF A WARM FRONT FOR FRIDAY...BUT VFR WILL REMAIN
THE PREVAILING CATEGORY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: NONE
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H L H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z FRIDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/TAX
NEAR TERM...TAX
SHORT TERM...TRM
LONG TERM...26
AVIATION...TAX
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
641 AM CDT THU MAR 29 2012
.AVIATION...
A MODEST LOW LEVEL WIND MAXIMUM AROUND 35 KTS AT 800 FT ABOVE THE
GROUND CONTINUED OVER THE CENTRAL SOUTH PLAINS NEAR KLBB ACCORDING
TO THE HIGH RESOLUTION REESE CENTER SODAR FROM THE WEST TEXAS
MESONET. THE CURRENT RUC RUN SHIFTS THIS MAX TO THE NORTHEAST
BETWEEN 13Z AND 14Z THIS MORNING ABOUT AS MIXING OUT BEGINS.
SHALLOW LOW LEVEL MOISTURE WAS MORE NOTABLE WITH A PATCH OF
STRATUS FORMING NEAR KHOB AND THE LEADING EDGE OF A LARGE AREA OF
STRATUS NEAR KABI. SOME CHANCE THAT WE COULD SEE AN LIFR CIG FORM
NEAR EITHER KCDS OR KLBB OVER THE NEXT FEW HOURS BUT OVER-ALL RISK
SEEMS TOO LOW FOR INCLUSION IN THE TAF. WE DID HOLD ON TO MINOR
VISIBILITY RESTRICTIONS...HOWEVER...THROUGH 14Z. BY LATE MORNING
EXPECT DRIER SOUTHWEST BREEZES TO DOMINATE KLBB WHILE A DRY-LINE
WILL BE IN POSITION NEAR KCDS. APPROACH OF AN UPPER LEVEL TROUGH
LATER TODAY COULD BREAK CAP AND ALLOW HIGH-BASED THUNDERSTORMS NOT
FAR FROM KCDS. RETAINED CB MENTION AT KCDS LATER TODAY. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 514 AM CDT THU MAR 29 2012/
SHORT TERM...
A FULL-LATITUDE UPPER LEVEL TROUGH WILL SWING EAST FROM THE ROCKIES
INTO THE NORTHERN AND CENTRAL HIGH PLAINS LATE THIS AFTERNOON AND
EVENING. SOMEWHAT ENHANCED LOW LEVEL WEST TO SOUTHWEST FLOW SHOULD
DEVELOP ON THE CAPROCK AND HELP TIGHTEN A DRY-LINE OVER THE ROLLING
PLAINS...PERHAPS DIRECTLY ADJACENT TO THE CAP-ROCK. PRIMARY UPWARDS
FORCING WILL OCCUR TO THE NORTH...BUT WE MAY SEE ENOUGH LIFT WITH A
MODESTLY UNSTABLE AIRMASS TO BREAK THE CAP AND ALLOW DEVELOPMENT OF
A FEW HIGH-BASED STORMS ALONG THE DRY-LINE. SOME THREAT FOR ENTIRE
DRY-LINE TO ERUPT BUT FORCING WEAKER HEADING SOUTHWARD AS WELL.
SEVERE THREAT FROM STORMS WILL BE HIGHEST AS WELL OVER NORTHERN
ROLLING PLAINS WITH STRONG WINDS GREATEST RISK. WE TRIMMED THUNDER
CHANCES A BIT MORE TO THE EAST WITH SOLUTIONS FAVORING THE DRY
SCENARIO ON THE CAPROCK TODAY WHILE EXPANDING LOW CHANCE MENTION
THIS EVENING OVER THE NORTHERN ROLLING PLAINS. THUNDER CHANCES WILL
DIMINISH LATER TONIGHT WHILE A COLD FRONT SHOULD SETTLE SOUTHWARD
OUT OF THE PANHANDLE INTO NORTHERN ZONES LATER TONIGHT. VERY WARM
TEMPERATURES FAVORED AGAIN TODAY WITH MINOR CHANGES. RMCQUEEN
LONG TERM...
LOW AMPLITUDE RIDGING WILL RETURN TO THE AREA ON FRIDAY BEHIND A
MINOR DISTURBANCE PASSING OVERHEAD AROUND MID-DAY. THIS RIDGING
WILL PERSIST UNTIL EARLY SUNDAY MORNING WHEN A RETURN TO ENHANCED
SOUTHWESTERLY FLOW COMES ON SUNDAY AHEAD OF A POTENT STORM SYSTEM
DIVING DOWN THE WEST COAST. GUIDANCE CONTINUES TO SLOW THE
PROGRESSION OF THE SYSTEM WHICH WILL HELP THE WIND/FIRE WEATHER
POTENTIAL TO SOME EXTENT THOUGH BOTH WIND SPEEDS AND FIRE DANGER WILL BE
ENHANCED. BY MONDAY MORNING NVA WILL SET IN WITH A RETURN TO
RIDGING FOR MID-WEEK.
QUESTION WILL BE IF THIS HAS MUCH CHANCE AT ALL AT INITIATING
CONVECTION ACROSS THE AREA FOR FRIDAY...GIVEN THE TRENDS THIS
WEEK...TSTM CHANCES REMAIN QUITE LOW...ACTUALLY...TOO LOW FOR A
MENTION IN THE GRIDS. THUS WILL CONTINUE WITH A POP FREE FORECAST
FOR THE ENTIRE EXTENDED. OF NOTE THOUGH ON FRIDAY WILL BE A WEAK
COLD FRONT WHICH IS PROGGED TO ENTER AT LEAST THE NORTHERN ZONES.
THIS WOULD UNDOUBTEDLY PLAY HAVOC WITH AFTERNOON HIGHS. THE
BOUNDARY IS TRENDING FURTHER SOUTH THAN EVIDENT FOR THE LAST FEW
NIGHTS AND THUS...WILL BLEND TEMPS DOWNWARD SOMEWHAT ACROSS THE
NORTH FRIDAY AFTERNOON. DRYLINE WILL REMAIN EAST OF THE AREA FOR
MUCH OF THE REST OF THE EXTENDED. WINDS STILL LOOK TO BE QUITE BREEZY ON
SUNDAY WITH AN ATTENDANT FIRE WEATHER THREAT DUE TO THE DRY NATURE
OF THE LOWER ATMOSPHERE. SUNDAY H7 GRADIENTS OF 60M/200NM WILL
LIKELY PUSH US INTO WIND ADVISORY TERRITORY AND IF TRENDS DO NOT
CHANGE WITH VIGOR...A RED FLAG PRODUCT AS WELL. COLD FRONT DUE IN
SUNDAY NIGHT WILL BRING GUSTY WINDS IN ITS WAKE AND THESE WINDS
MAY VERY WELL BRING ADVISORY WINDS TO THE AREA THROUGH MONDAY AS A
VERY TIGHT PRESSURE GRADIENT OVERSPREADS THE AREA. AFTER THE WINDS
DIE DOWN LATE MONDAY...QUIESCENT WEATHER RETURNS TO THE SOUTHERN
PLAINS.
FIRE WEATHER...
UPPER TROUGH PASSING EAST FROM THE ROCKIES INTO THE CENTRAL AND
NORTHER HIGH PLAINS THIS AFTERNOON AND EVENING SHOULD LEAD TO
ENHANCED DOWNWARD FORCING ACROSS CENTRAL AND WESTERN SOUTH PLAINS
WITH DEEPER MIXING INTO SOMEWHAT STRONGER WEST-SOUTHWEST FLOW ALOFT.
THIS SHOULD BE ENOUGH FOR MARGINAL WINDS TO ENHANCE FIRE WEATHER
RISK ALONG WITH VERY DRY AIRMASS AND TEMPERATURES WELL ABOVE NORMAL.
GREEN-UP RECENTLY CERTAINLY HAS LESSENED FUELS THREAT FOR MANY AREAS
CENTRAL AND EAST...PROBABLY LESS SO IN THE WEST. FIRE DANGER WAS
RATED HIGH ON WEDNESDAY AND WILL NOT BE ANY LESS TODAY. ANYWAY...
ENOUGH OF A MARGINAL RISK TODAY TO INCLUDE A FIRE DANGER STATEMENT
FOR AREAS ON THE CAP-ROCK THIS AFTERNOON AND EARLY THIS EVENING.
RMCQUEEN
DRY SURFACE CONDITIONS WILL CONTINUE THE REST OF THE WEEK LEADING TO
INCREASING FUEL VOLATILITY ACROSS THE REGION ESPECIALLY IN THE WEST
WHERE GREEN-UP HAS BEEN SLOW DUE TO A LACK OF MOISTURE. SATURDAY
MAY SEE ANOTHER RANGELAND FIRE DANGER DAY WITH MIN RH
VALUES NEAR 10 PCT. SUNDAY HAS PROSPECTS TO BE A CRITICAL FIRE
WEATHER DAY AS WINDS OF 20-30MPH COMBINE WITH MIN RH VALUES NEAR
10 PCT. H8 THERMAL RIDGE NOW PROGGED TO BE ORIENTED FROM THE BIG
BEND INTO WESTERN KANSAS WHILE H5 SPEED MAX WILL LIE ACROSS
CENTRAL NEW MEXICO. THIS POINTS TO THE MOST SIGNIFICANT THREAT
NEAR THE TX/NM STATE LINE. THE THREAT MAY PERSIST OVERNIGHT
WITH LITTLE RECOVERY AND BREEZY CONDITIONS. A COLD FRONT IS DUE IN
SUNDAY NIGHT AND WINDS BEHIND THE FRONT OF 25 TO 35 MPH MAY HAMPER
EFFORTS ON ANY FIRES WHICH MAY INITIATE. THESE WINDS LOOK TO
PERSIST WELL INTO MONDAY BEFORE SUBSIDING MONDAY NIGHT. THE
LATE WEEKEND SYSTEM CERTAINLY CONTINUES TO WARRANT CAREFUL
MONITORING.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 86 45 80 47 86 / 10 10 10 10 0
TULIA 87 47 78 51 87 / 10 10 10 10 0
PLAINVIEW 87 47 80 51 88 / 10 10 10 10 0
LEVELLAND 88 48 84 52 89 / 10 10 10 10 0
LUBBOCK 89 49 84 52 89 / 10 10 10 10 0
DENVER CITY 87 49 87 52 89 / 10 10 10 10 0
BROWNFIELD 89 50 87 53 90 / 10 10 10 10 0
CHILDRESS 91 55 82 55 89 / 20 30 10 10 0
SPUR 90 54 86 56 91 / 20 20 10 10 0
ASPERMONT 88 58 90 60 91 / 20 20 10 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1140 AM MDT THU MAR 29 2012
.UPDATE...
ISSUED AT 1130 AM MDT THU MAR 29 2012
CURRENT OBSERVATIONS SHOW ONLY FAIR WEATHER CUMULUS OVER THE
FORECAST AREA AT THIS TIME WITH NO SHOWERS NOTED. BASED ON THIS AND
SHORT TERM MODELS INDICATING VERY LIMITED QPF CHANCES FOR THE
AFTERNOON...DECIDED TO LOWER THE REMAINING POPS TO ISOLATED
COVERAGE OVER THE NORTHERN MOUNTAINS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 438 AM MDT THU MAR 29 2012
AT 3 AM THE COLD FRONT WAS ACROSS THE NW HALF OF THE FORECAST AREA
AND SAGGING SOUTH. DEWPOINTS CLIMBING FROM TEENS TO 20-30S WITH
THE FRONT. ONLY LIGHT SHOWERS HAVE BEEN CAUGHT BY SURFACE
REPORTING STATIONS IN THE PARK AND ELK MOUNTAINS. GENERALLY
FOLLOWED THE HRRR LIGHT PRECIP PATTERN FOR THIS MORNING. THE WEAK
COLD CORE BRUSHES THE NORTH THIS MORNING WITH MARGINAL INSTABILITY
SHRINKING INTO THE EARLY AFTERNOON. OTHERWISE TEMPERATURES WILL BE
3-5 DEGREES COOLER THAN ON WEDNESDAY BUT WILL STILL BE WELL ABOVE
NORMAL. WINDS WILL VEER TO NW BEHIND THE FRONT AND DIMINISH
THROUGH THE AFTERNOON.
A SECOND WEAK WAVE PROGGED TO PASS THIS EVENING BUT LOOKS MOISTURE
STARVED BELOW 500MB. SO LOWERED POPS FOR THIS EVENING. THE MID-
HIGH CLOUDS WILL SHIFT EAST AFTER MIDNIGHT BUT MAY LIMIT THE LOW
TEMPERATURES OVERNIGHT ESPECIALLY IN WESTERN COLORADO. WARMING
TREND BEGINS ON FRIDAY IN A FLAT BENIGN FLOW.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 438 AM MDT THU MAR 29 2012
DRY AND UNSEASONABLY WARM WEATHER WILL CONTINUE INTO THE EARLY
PART OF THE WEEKEND AS FLOW SHIFTS TO THE SOUTHWEST AHEAD OF AN
APPROACHING PACIFIC TROUGH. IN FACT...INDICATIONS ARE THAT HIGHS
WILL BE NEAR RECORD LEVELS. A TIGHTENING PRESSURE GRADIENT WILL
GENERATE STRONG AND GUSTY SOUTHWEST WINDS WHICH WILL NOT ONLY HELP
LIFT HIGHS NEARLY 20 DEGREES ABOVE NORMAL BUT WILL ALSO DRIVE RH
DOWN...POTENTIALLY YIELDING CRITICAL FIRE WEATHER CONDITIONS.
MODELS WERE CONSISTENT IN MOVING THE TROUGH OVER THE GREAT BASIN
SATURDAY NIGHT. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM IS
EXPECTED TO JUST REACH THE GREEN RIVER SUNDAY MORNING. PRE-
FRONTAL WINDS WILL CONTINUE MUCH OF THE NIGHT HELPING TO BUOY
OVERNIGHT LOWS. PRECIPITATION WILL LARGELY HOLD OFF UNTIL THE
FRONT SWEEPS ACROSS THE REGION SUNDAY. SNOW LEVELS WILL BEGIN NEAR
THE TREE-LINE...LOWERING WITH FROPA TO VALLEY FLOORS ACROSS THE
NORTH AND THE HIGHER CENTRAL VALLEYS. LATEST SNOWFALL OUTPUT
SUGGESTS AMOUNTS WILL LARGELY BE BELOW ADVISORY LEVELS...THOUGH
BLOWING SNOW AND REDUCED VISIBILITY COULD CREATE SOME TRAVEL
DIFFICULTIES. CLOUDS...SHOWERS AND CAA BEHIND THE FRONT WILL
RESULT IN MUCH COOLER TEMPERATURES SUNDAY...THOUGH STILL JUST A
BIT ABOVE NORMAL.
SNOW IS EXPECTED TO LINGER ALONG THE CONTINENTAL DIVIDE SUNDAY
NIGHT...LIKELY ENDING BY MONDAY MORNING. TEMPERATURES WILL REMAIN
COOL MONDAY UNDER A NORTHWEST FLOW REGIME. LOOK FOR A WARMING
TREND FOR THE MIDDLE OF THE WEEK AS FLOW BECOMES ZONAL TUESDAY
...THEN SHIFTS TO THE SOUTHWEST WEDNESDAY. DRY CONDITIONS ARE
EXPECTED THROUGH MIDWEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1130 AM MDT THU MAR 29 2012
VFR CONDITIONS ARE EXPECTED TO PERSIST AT ALL TAF SITES THROUGH
FRIDAY MORNING.THIS MORNINGS COLD FRONT HAS DISSIPATED WITH ONLY
SCATTERED MID LEVEL CLOUDS CURRENTLY OVER SOME OF THE MOUNTAINS.
ANOTHER WEAK UPPER LEVEL WAVE WILL PASS THROUGH THIS EVENING
BRINGING WITH IT AN INCREASE IN UPPER/MID LEVEL CLOUDS BEGINNING
THIS AFTERNOON. CLOUDS WILL BE AROUND THROUGH THE FIRST HALF OF
TONIGHT WITH A FEW LIGHT SHOWERS POSSIBLE OVER THE FAR NORTHERN
MOUNTAINS FOLLOWED BY CLEARING EARLY ON FRIDAY.
&&
.FIRE WEATHER...
ISSUED AT 438 AM MDT THU MAR 29 2012
A PACIFIC TROUGH WILL MOVE INTO THE WESTERN GREAT BASIN SATURDAY
RESULTING IN A SHIFT TO SOUTHWEST FLOW. A TIGHTENING PRESSURE
GRADIENT COMBINED WITH NEAR RECORD WARMTH WILL HELP MIX STRONG
WINDS ALOFT TO THE SURFACE DURING THE AFTERNOON AND EVENING. THE
DEEP MIXING WILL ALSO SERVE TO REDUCE RELATIVE HUMIDITY BELOW 15
PERCENT ACROSS MUCH OF THE REGION DURING PEAK HEATING. THAT
SAID...NOT COMFORTABLE ISSUING FIRE WEATHER WATCH FOR THE LATE 5TH
AND 6TH PERIODS AND WILL LET LATER SHIFTS PULL THE TRIGGER AS THE
DETAILS COME TOGETHER.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...TB/JAD
SHORT TERM.....JOE
LONG TERM......NL
AVIATION...TB/JAD
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
155 PM EDT THU MAR 29 2012
.SYNOPSIS...
18Z WATER VAPOR AND H4 RUC ANALYSIS SHOWS AND AMPLIFIED BUT
PROGRESSIVE NORTHERN STREAM FLOW. NORTHERN STREAM ARRIVES OVER THE
PACIFIC NORTHWEST COAST WITH AN ELONGATED SHORTWAVE NEAR THE
CONTINENTAL DIVIDE. THE FLOW THEN RIDGING NORTHWARD INTO
SOUTH-CENTRAL CANADA/WESTERN GREAT LAKES BEFORE DIVING BACK
SOUTHEASTWARD OVER THE NE/MID-ATLANTIC STATES. CLOSER TO HOME WE
FIND BROAD UPPER RIDGING IN PLACE OVER THE EASTERN GULF OF MEXICO
AND THE FL PENINSULA. A WEAK SHORTWAVE CURRENTLY OVER TEXAS WILL
SLOWLY MOVE EAST ALONG THE NORTHERN GULF COAST DURING THE NEXT 24-36
HOURS AND POTENTIALLY BRING AN ENHANCEMENT TO THE SHOWER/STORM
CHANCES OVER OUR NORTHERN ZONES BY FRIDAY EVENING. WV IMAGERY HAS
SHOWN GRADUAL MOISTURE ADVECTION INTO OUR REGION WITHIN THE UPPER
LEVELS. THIS TREND IS SEEN CLEARLY OVER THE PAST 24 HOURS LOOKING AT
THE KTBW SOUNDING PROFILE...WHERE DEWPOINT DEPRESSIONS HAVE
SIGNIFICANTLY DECREASED ABOVE THE H5 LEVEL. THE 12Z SOUNDING STILL
SHOWS THAT WE WERE DEALING WITH A HEALTHY LAYER OF DRY AIR/LOW
THETA-E VALUES BETWEEN 800-500MB. MODEL FORECAST SOUNDING ALL SHOW
THAT EVEN THIS LAYER WILL CONTINUE TO MOISTEN SOMEWHAT BY THE END OF
THE DAY. VISIBLE SATELLITE SHOWS A SCT-BKN CU FIELD WELL ESTABLISHED
AWAY FROM THE MORE STABILIZED BOUNDARY LAYER BEHIND THE DEVELOPING
SEA-BREEZE. THE FOCUS ALONG THE SEABREEZE COMBINED WITH THE SLIGHTLY
MORE FAVORABLE COLUMN FOR CONVECTION SHOULD STILL GIVE WAY TO
ISOLATED SHOWERS FOR THE LATE AFTERNOON/EARLY EVENING. WILL KEEP THE
SLIGHT CHANCE 20% POPS FOR THE REST OF THE DAY INLAND AND REMOVE
RAIN CHANCES FROM THE BEACHES.
AT THE SURFACE...GRADIENT IS QUITE WEAK ACROSS THE FORECAST AREA
WITH THE SUBTROPICAL RIDGE AXIS EXTENDING ACROSS THE FL PENINSULA.
CURRENT TEMPS HAVE REACHES THE LOWER 80S INLAND WITH A COUPLE
DEGREES FURTHER RISE EXPECTED. LOCAL SEA-BREEZE CIRCULATIONS WILL
HELP HOLD DOWN TEMPS A FEW DEGREES INTO THE MID/UPPER 70S AT THE
BEACHES.
.SHORT TERM (TONIGHT THROUGH SATURDAY)...
TONIGHT...
WITHOUT ANY CLEAR UPPER LEVEL SUPPORT...SHOULD SEE A FEW LINGERING
SHOWERS ONLY UNTIL AROUND 02-03Z THIS EVENING BEFORE FADING WITH THE
LOSS OF DIURNAL HEATING. THE REMAINDER OF THE NIGHT LOOKS QUIET WITH
JUST A FEW HIGHER LEVEL CLOUDS. INLAND LOW TEMPS WILL DROP TO THE
UPPER 50S/LOWER 60S...WITH MIDDLE 60S ALONG THE COAST.
FRIDAY...
SURFACE RIDGE AXIS WILL SHIFT A BIT FURTHER SOUTH ALLOWING A MORE
MOIST SOUTHWEST LOW LEVEL FLOW TO DEVELOP ACROSS THE AREA. MID/UPPER
LEVEL SHORTWAVE ENERGY WILL CONTINUE TO ADVANCE ALONG THE NORTHERN
GULF COAST AND BE APPROACHING THE NORTHERN FL PENINSULA BY EVENING.
DEEPER MOISTURE...AND WEAK OVERSPREADING SYNOPTIC SUPPORT/QG FORCING
AHEAD OF THE SHORTWAVE SHOULD SUPPORT AT LEAST ISOLATED TO WIDELY
SCT CONVECTION FOR THE AFTERNOON HOURS. HAVE NOT GONE ALL THAT
AGGRESSIVE WITH THE RAIN CHANCES WITHIN THIS FORECAST PACKAGE DUE TO
SOME MODEL DISAGREEMENT AS TO WHEN THE SYNOPTIC SUPPORT WILL
ARRIVE...HOWEVER WOULD NOT BE SURPRISED IF THESE POP NUMBERS NEEDED
TO BE RAISED. TEMPERATURES LOOK TO REMAIN ABOVE AVERAGE IN THE
MIDDLE 80S AWAY FROM THE COAST...AND MID 70S TO AROUND 80 AT THE
COAST.
FRIDAY NIGHT...
INITIAL SHORTWAVE WILL QUICKLY PASS NORTH OF THE REGION THE FIRST
HALF OF THE NIGHT WITH A WEAK SURFACE FRONT/TROUGH STALLING UP
TOWARDS THE FL PANHANDLE/NE GULF OF MEXICO. DESPITE THE WEAK FOCUS
ALONG IS BOUNDARY...GLOBAL MEMBERS/SREF SHOWING AT LEAST SOME
CONVECTION OVER THE NORTHERN HALF OF THE FORECAST AREA. FORECAST POP
GRADIENT WILL SHOW RAIN CHANCES AROUND 40% UP TOWARD LEVY COUNTY AND
TAPER DOWN TO SLIGHT CHANCE 20% AROUND THE TAMPA BAY AREA. FURTHER
SOUTH...WILL KEEP THINGS DRY FOR NOW. A WARM OVERNIGHT ON TAP WITH
THE FLOW OFF THE GULF. LOW TEMPS RANGING FROM THE LOWER 60S INLAND
TO THE MIDDLE/UPPER 60S CLOSE TO THE WATER.
SATURDAY...
EXPECTING ZONAL MID/UPPER LEVEL FLOW WITH ANY SIGNIFICANT SYNOPTIC
SUPPORT REMAINING TO OUR NORTH. AT THE SURFACE...SUBTROPICAL RIDGE
AXIS WILL HOLD TO OUR SOUTH KEEPING A MOIST WEST/SW FLOW OFF THE
GULF. WITH WESTERLY FLOW WILL AID THE INLAND SEA-BREEZE PROPAGATION
HELPING TO KEEP THE BEST SHOWER/STORM CHANCES (~30%) TO THE WEST OF
THE I-75 CORRIDOR. TEMPS FOR YET ANOTHER DAY REACHING INTO THE
MIDDLE 80S INLAND AND MID/UPPER 70S AT THE BEACHES.
&&
.LONG TERM (SATURDAY NIGHT - THURSDAY)...
FORECAST CONFIDENCE IS INCREASING AS MODELS HAVE COME MORE IN LINE
DURING THE LONG TERM PERIOD. A WEAK UPPER LEVEL SHORTWAVE WILL MOVE
OFF THE SOUTHEAST U.S. COAST SATURDAY NIGHT WITH SOME RIDGING
BUILDING OVER THE SOUTHEAST U.S. AND FLORIDA SUNDAY AND MONDAY AHEAD
OF THE NEXT TROUGH MOVING THROUGH THE CENTRAL STATES. THE SURFACE
RIDGE AXIS WILL REMAIN ACROSS SOUTH FLORIDA DURING THIS TIME
CONTINUING THE SOUTH TO SOUTHWEST FLOW ACROSS THE AREA. ENOUGH
MOISTURE COMBINED WITH SUFFICIENT INSTABILITY...DAYTIME HEATING AND
THE SEA BREEZE WILL LEAD TO A SLIGHT CHANCE OF AFTERNOON
THUNDERSTORMS...BUT THE FLOW WILL DRIVE THE WEST COAST SEA BREEZE
WELL INLAND BOTH DAYS AND THEREFORE KEEP THE BEST CHANCE OF SEEING A
SHOWER OR THUNDERSTORM OVER THE EASTERN HALF OF THE FLORIDA
PENINSULA. DURING TUESDAY AND WEDNESDAY THE NEXT TROUGH WILL MOVE
ACROSS THE EASTERN U.S. HELPING TO PUSH A COOL FRONT TOWARD THE
REGION. PRESENT GUIDANCE DOES MOVE THIS FRONT THROUGH THE AREA
TUESDAY NIGHT AND WEDNESDAY...BUT WHETHER THIS BOUNDARY ACTUALLY
MOVES ALL THE WAY THROUGH OR NOT...IT DOES LOOK LIKE THE ENTIRE
REGION WILL SEE A CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY INTO
WEDNESDAY.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE PERIOD. DAYTIME
HIGHS WILL BE MOSTLY IN THE MID TO UPPER 80S...EXCEPT CLOSE TO THE
COAST WHERE THE ONSHORE FLOW WILL KEEP READINGS IN THE UPPER 70S TO
LOWER 80S. OVERNIGHT LOWS WILL BE MOSTLY IN THE 60S...EXCEPT AROUND
70 ALONG THE COAST.
&&
.AVIATION...
A FEW SHOWERS MAY PRODUCE BRIEF MVFR CONDITIONS AT KLAL AFTER 21Z
WITH ADDITIONAL MVFR VISIBILITIES POSSIBLE AFTER 30/08Z AT KPGD AND
KLAL FROM PATCHY FOG...OTHERWISE MAINLY VFR CONDITIONS ARE EXPECTED
AT ALL TERMINAL SITES. SOUTHWEST TO WEST WINDS AROUND 10 KNOTS THIS
AFTERNOON WILL BECOME LIGHT AND VARIABLE AFTER 30/02Z TONIGHT.
&&
.MARINE...
WINDS AND SEAS ARE EXPECTED TO REMAIN GENERALLY BELOW HEADLINE
CRITERIA THROUGH FRIDAY. LOCAL SEA-BREEZE CIRCULATIONS WILL KEEP
WINDS ONSHORE THROUGH THE MIDDLE EVENING HOURS. LARGE SCALE FLOW
WILL BECOME MORE SOUTHERLY/PARALLEL TO THE COASTLINE OVERNIGHT AND
THEN VEER OUT OF THE SOUTHWEST BY THE END OF FRIDAY IN ADVANCE OF AN
APPROACHING WEAK COLD FRONT.
&&
.FIRE WEATHER...
A BRIEF PERIOD OF NEAR CRITICAL LEVELS OF RELATIVE HUMIDITY ARE
EXPECTED OVER INLAND ZONES FRIDAY AFTERNOON...HOWEVER CRITICAL
DURATIONS ARE NOT EXPECTED AND DISPERSION INDICES ARE FORECAST BELOW
75. INCREASING LOW LEVEL MOISTURE ARE EXPECTED TO PREVENT CRITICAL
LEVELS OF RELATIVE HUMIDITY DURING THE UPCOMING WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 64 83 66 83 / 15 20 20 30
FMY 63 86 65 86 / 15 20 10 10
GIF 59 86 62 86 / 20 20 15 30
SRQ 63 83 65 84 / 15 20 20 25
BKV 59 84 62 84 / 20 20 25 30
SPG 67 81 68 81 / 20 20 20 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...14/MROCZKA
AVIATION/FIRE WEATHER...57/MCMICHAEL
LONG TERM...69/CLOSE
AREA FORECAST DISCUSSION
NWS DES MOINES IA
600 PM CDT THU MAR 29 2012
.UPDATE 30/00Z AVIATION DISCUSSION...
.SHORT TERM /TONIGHT/...
MAIN FOCUS IS SHOWER AND THUNDERSTORM DEVELOPMENT AS SURFACE
LOW...CURRENTLY OVER NORTHERN KANSAS MOVES ACROSS SOUTHERN IOWA
TONIGHT. WHILE THIS IS HAPPENING...A COLD FRONT ACROSS THE EASTERN
DAKOTAS INTO NEBRASKA WILL ALSO MOVE ACROSS IOWA TONIGHT...SO THERE
COULD BE TWO ROUNDS OF PRECIPITATION FOCUS. WHAT WAS TO BE A WARM
FRONT HAS REMAINED STALLED ALONG THE MISSOURI RIVER IN
MISSOURI...WITH ONLY LIMITED PUSH NORTH INTO SE NEBRASKA...DUE TO
PERSISTENT CONVECTION IN NORTHERN MISSOURI. FRONT APPEARS UNLIKELY
TO MAKE INTO IOWA UNTIL MID OR LATE EVENING...SO THE OPPORTUNITY FOR
SURFACE BASED CONVECTION AND SIGNIFICANT SEVERE WEATHER POTENTIAL
APPEARS LIMITED. LOW-LEVEL SHEAR AND HELICITY WILL BE MODERATELY
STRONG OVER THE SOUTHWESTERN FORECAST AREA...BUT STORMS MOVING INTO
THAT AREA ARE LIKELY TO BE SOMEWHAT ELEVATED...SO MAIN THREAT WOULD
BE LARGE HAIL AND POTENTIALLY DAMAGING WINDS. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR AND NORTHEAST OF THE
SURFACE LOW AS IT TRACKS INTO IOWA THIS EVENING. MORE SCATTERED
DEVELOPMENT IS EXPECTED ALONG AND AHEAD OF THE COLD FRONT AS IT
MOVES EAST. RUC MODEL SEEMS TO HAVE A GOOD HANDLE ON THIS EVOLUTION.
SEVERE THREAT IS LIKELY TO DIMINISH AFTER 9-10 PM. THERE IS SOME
POTENTIAL FOR THE SOUTHERN CONVECTION TO BLOSSOM NORTHWARD AS THE
COLD FRONT APPROACHES...SO THE HEAVIER PRECIPITATION AXIS IS LIKELY
TO BE FROM LAMONI TO EAST OF DES MOINES WITH 0.5-0.75 INCHES
POSSIBLE. TEMPERATURES WILL NOT FALL RAPIDLY OVERNIGHT DUE TO CLOUD
COVER AND WARM AND MOIST ADVECTION FOR A GOOD PORTION OF THE NIGHT.
.LONG TERM /FRIDAY THROUGH THURSDAY/...
FORECAST HAS CHANGED SOMEWHAT FROM PREVIOUS ISSUANCES WITH A BIT
MORE EMPHASIS ON PRECIP FRIDAY NIGHT AND SATURDAY NIGHT. CURRENT
SYSTEM WILL HAVE DEPARTED BY ONSET OF THE PERIOD WITH FAIR WEATHER
AND MORE MILD TEMPERATURES FRIDAY. HOWEVER SOME SEMBLANCE OF
CURRENT INSTABILITY GRADIENT AND BAROCLINIC ZONE JUST TO OUR SOUTH
IS EXPECTED TO RETURN NORTHWARD FRIDAY NIGHT AND COULD VERY WELL
ACTIVE MUCH LIKE IT HAS SINCE YESTERDAY. NAM/GFS/SREF ARE NOT
REALLY SUGGESTING MUCH IN THE WAY OF PRECIP TOMORROW NIGHT...HOWEVER
RECENT GEM REGIONAL AND GLOBAL MODELS AS WELL AS ECMWF RUNS HAVE
SUGGESTED ELEVATED CONVECTION WILL DEVELOP OVER EASTERN SECTIONS
OVERNIGHT. ECMWF HAS SHOWN NICE BAROCLINIC ZONE AND LIFT ALONG 300K
ISENT SURFACE. DO NOT EXPECT ANYTHING SIGNIFICANT BUT AM NO LONGER
COMFORTABLE GOING DRY SO SLIGHTS HAVE BEEN INTRODUCED. SIMILAR
SITUATION SATURDAY NIGHT ALTHOUGH DOMESTIC MODELS ARE NOW ON BOARD
TOO IN SIMILAR AREAS SO HAVE ADDED SLIGHT MENTIONS THERE AS WELL.
MODELS CONTINUE TO HAVE VARIED SOLUTIONS FOR SYSTEM EARLY NEXT WEEK
WITH DIFFERENT IDEAS ON STRENGTH OF SHORT WAVE IN BASE OF THE LONG
WAVE TROUGH AND OVERALL TIMING. GFS/GEM SOLUTIONS ARE SLOWER WITH
MORE EMPHASIS ON SRN PLAINS CLOSED LOW WHILE ECWMF HAS MORE NRN
STREAM ENERGY AND FASTER SOLUTION. THESE VARIED SOLUTIONS DO NOT
HAVE MUCH IMPACT ON SENSIBLE WEATHER HOWEVER WITH CHANCES INCREASE
EARLY MONDAY MORNING AND CONTINUE INTO MONDAY EVENING CENTRAL AND
EAST. REMAINDER OF THE FORECAST IS MILD AND DRY WITH UPPER LEVEL
RIDGING BUILDING BACK INTO THE MO VALLEY. NO FROST OR FREEZING
CONDITIONS APPEAR TO BE IN THE OFFING...AT LEAST THROUGH THE END OF
THE NEXT WORK WEEK.
&&
.AVIATION...30/00Z
MAIN CONCERNS IN THE IMMEDIATE 6-12 HOURS IS THUNDER. WARM FRONT
BECOMING ACTIVE AND APPROACHING COLD FRONT FROM NORTWEST WILL
INCREASE CHANCES FOR THUNDER BY 02-03Z WEST AND SOUTH...THEN
TRACKING EAST ACROSS ALL TAF SITES THROUGH 07Z. LOW RESPONSIBLE FOR
ACTIVITY WILL PULL EAST BY 12Z AND EXPECT SKIES TO CLEAR QUICKLY.
CHANCE FOR INCREASED WINDS/SMALL HAIL EXISTS FOR SOUTHERN TAF SITES
AFT 03Z...BUT MOST STORMS APPEAR TO BE ELEVATED WITH LESS SUPPORT
OVER THE REGION...SO VISBY AND BRIEFLY LOWER CIGS ALONG WITH SOME
WIND GUSTS APPEAR TO BE MAIN CONCERNS. WILL MONITOR THROUGH EVENING
AS EVENT UNFOLDS. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...JUNGBLUTH
AVIATION...REV
LONG TERM...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
349 PM CDT THU MAR 29 2012
.SHORT TERM /TONIGHT/...
MAIN FOCUS IS SHOWER AND THUNDERSTORM DEVELOPMENT AS SURFACE
LOW...CURRENTLY OVER NORTHERN KANSAS MOVES ACROSS SOUTHERN IOWA
TONIGHT. WHILE THIS IS HAPPENING...A COLD FRONT ACROSS THE EASTERN
DAKOTAS INTO NEBRASKA WILL ALSO MOVE ACROSS IOWA TONIGHT...SO THERE
COULD BE TWO ROUNDS OF PRECIPITATION FOCUS. WHAT WAS TO BE A WARM
FRONT HAS REMAINED STALLED ALONG THE MISSOURI RIVER IN
MISSOURI...WITH ONLY LIMITED PUSH NORTH INTO SE NEBRASKA...DUE TO
PERSISTENT CONVECTION IN NORTHERN MISSOURI. FRONT APPEARS UNLIKELY
TO MAKE INTO IOWA UNTIL MID OR LATE EVENING...SO THE OPPORTUNITY FOR
SURFACE BASED CONVECTION AND SIGNIFICANT SEVERE WEATHER POTENTIAL
APPEARS LIMITED. LOW-LEVEL SHEAR AND HELICITY WILL BE MODERATELY
STRONG OVER THE SOUTHWESTERN FORECAST AREA...BUT STORMS MOVING INTO
THAT AREA ARE LIKELY TO BE SOMEWHAT ELEVATED...SO MAIN THREAT WOULD
BE LARGE HAIL AND POTENTIALLY DAMAGING WINDS. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR AND NORTHEAST OF THE
SURFACE LOW AS IT TRACKS INTO IOWA THIS EVENING. MORE SCATTERED
DEVELOPMENT IS EXPECTED ALONG AND AHEAD OF THE COLD FRONT AS IT
MOVES EAST. RUC MODEL SEEMS TO HAVE A GOOD HANDLE ON THIS EVOLUTION.
SEVERE THREAT IS LIKELY TO DIMINISH AFTER 9-10 PM. THERE IS SOME
POTENTIAL FOR THE SOUTHERN CONVECTION TO BLOSSOM NORTHWARD AS THE
COLD FRONT APPROACHES...SO THE HEAVIER PRECIPITATION AXIS IS LIKELY
TO BE FROM LAMONI TO EAST OF DES MOINES WITH 0.5-0.75 INCHES
POSSIBLE. TEMPERATURES WILL NOT FALL RAPIDLY OVERNIGHT DUE TO CLOUD
COVER AND WARM AND MOIST ADVECTION FOR A GOOD PORTION OF THE NIGHT.
.LONG TERM /FRIDAY THROUGH THURSDAY/...
FORECAST HAS CHANGED SOMEWHAT FROM PREVIOUS ISSUANCES WITH A BIT
MORE EMPHASIS ON PRECIP FRIDAY NIGHT AND SATURDAY NIGHT. CURRENT
SYSTEM WILL HAVE DEPARTED BY ONSET OF THE PERIOD WITH FAIR WEATHER
AND MORE MILD TEMPERATURES FRIDAY. HOWEVER SOME SEMBLANCE OF
CURRENT INSTABILITY GRADIENT AND BAROCLINIC ZONE JUST TO OUR SOUTH
IS EXPECTED TO RETURN NORTHWARD FRIDAY NIGHT AND COULD VERY WELL
ACTIVE MUCH LIKE IT HAS SINCE YESTERDAY. NAM/GFS/SREF ARE NOT
REALLY SUGGESTING MUCH IN THE WAY OF PRECIP TOMORROW NIGHT...HOWEVER
RECENT GEM REGIONAL AND GLOBAL MODELS AS WELL AS ECMWF RUNS HAVE
SUGGESTED ELEVATED CONVECTION WILL DEVELOP OVER EASTERN SECTIONS
OVERNIGHT. ECMWF HAS SHOWN NICE BAROCLINIC ZONE AND LIFT ALONG 300K
ISENT SURFACE. DO NOT EXPECT ANYTHING SIGNIFICANT BUT AM NO LONGER
COMFORTABLE GOING DRY SO SLIGHTS HAVE BEEN INTRODUCED. SIMILAR
SITUATION SATURDAY NIGHT ALTHOUGH DOMESTIC MODELS ARE NOW ON BOARD
TOO IN SIMILAR AREAS SO HAVE ADDED SLIGHT MENTIONS THERE AS WELL.
MODELS CONTINUE TO HAVE VARIED SOLUTIONS FOR SYSTEM EARLY NEXT WEEK
WITH DIFFERENT IDEAS ON STRENGTH OF SHORT WAVE IN BASE OF THE LONG
WAVE TROUGH AND OVERALL TIMING. GFS/GEM SOLUTIONS ARE SLOWER WITH
MORE EMPHASIS ON SRN PLAINS CLOSED LOW WHILE ECWMF HAS MORE NRN
STREAM ENERGY AND FASTER SOLUTION. THESE VARIED SOLUTIONS DO NOT
HAVE MUCH IMPACT ON SENSIBLE WEATHER HOWEVER WITH CHANCES INCREASE
EARLY MONDAY MORNING AND CONTINUE INTO MONDAY EVENING CENTRAL AND
EAST. REMAINDER OF THE FORECAST IS MILD AND DRY WITH UPPER LEVEL
RIDGING BUILDING BACK INTO THE MO VALLEY. NO FROST OR FREEZING
CONDITIONS APPEAR TO BE IN THE OFFING...AT LEAST THROUGH THE END OF
THE NEXT WORK WEEK.
&&
.AVIATION...29/18Z
WARM FRONT IS NOT MAKING MUCH NORTHWARD PROGRESS DUE TO LOW CLOUDS
AND PERSISTENT THUNDERSTORMS OVER MO. TWO ROUND OF THUNDERSTORMS
POSSIBLE THIS EVENING AS LOW LEVEL MOISTURE LIFTS NORTH. FIRST ROUND
MAY HAVE EMBEDDED TSRA AS IT LIFTS NE ACROSS IA FROM 29/23Z-30/04Z.
SECOND ROUND WILL BE A NARROW BAND AS IT SWINGS EAST ACROSS NORTHERN
TAF SITES 30/04-07Z. IN BETWEEN...LIKELY TO BE LOW CLOUDS WITH MVFR
CIGS. COULD BE SOME IFR CEILINGS AND EVEN SOME FOG BEFORE WLY FLOW
AND DRIER AIR SWEEPS WEST TO EAST AFTER 30/09-12Z. ANY SEVERE
THUNDERSTORMS ARE LIKELY TO BE SW OF KDSM AND KOTM.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/AVIATION...JUNGBLUTH
LONG TERM...SMALL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1236 PM CDT THU MAR 29 2012
...UPDATED AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 930 AM CDT THU MAR 29 2012
HAVE CANCELLED THE DENSE FOG ADVISORY FOR TREGO/ELLIS COUNTIES AS
THE FOG HAS BEEN ERODING RAPIDLY OUT OF THAT AREA. MORNING TEMPERATURES
ARE ALSO A LITTLE WARMER IN AREAS OUT ALONG AND WEST OF HIGHWAY
83. HAVE MADE A FEW TWEAKS TO ACCOUNT FOR THIS AS WELL.
UPDATE ISSUED AT 634 AM CDT THU MAR 29 2012
SOUTHWEST WINDS WERE DEVELOPING ACROSS WESTERN KANSAS WITH LOWER
DEWPOINTS BEGINNING TO ADVECT INTO PORTIONS OF THE DENSE FOG
ADVISORY AREA. SATELLITE, SURFACE OBS AND PHONE CALLS AT OF 6 AM
INDICATED PATCH FOG AT BEST WERE OCCURRING SOUTH OF INTERSTATE 70.
AS A RESULT WILL TRIM SEVERAL COUNTIES OUT OF THE DENSE FOG
ADVISORY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 217 AM CDT THU MAR 29 2012
.SYNOPSIS...
ISSUED AT 217 AM CDT THU MAR 29 2012
00Z 300 HPA SYNOPTIC MAP ANALYSIS SHOWS A 95 KT JET PUSHING ASHORE ACROSS
THE PACIFIC NORTHWEST IN ASSOCIATION WITH BROAD TROUGH EXTENDING FROM
THE PACNW TO THE NORTHERN ROCKIES. WEAKER 50 TO 75 KT BROAD W/NW FLOW
EXTENDED ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION.
THE 500 HPA FLOW PATTERN SHOWED THE TROUGH AXIS IN ASSOCIATION WITH
THE AFOREMENTIONED JET STREAK FROM THE NORTHEAST PACIFIC AND SE ACROSS
THE GREAT BASIN. LOWER IN THE ATMOSPHERE...NAMELY THROUGH THE 700 AND
850 HPA LAYERS, THE MOST INTERESTING ITEM WAS WARM AND DRY FLOW IN
THE LEE OF THE ROCKIES. AT THE SFC, MSAS SURFACE PRESSURE ANALYSIS SHOWED
A WEAK LOW PRESSURE CENTER ACROSS SE COLORADO. A WARM FRONT WAS EXTENDING
FROM THIS FEATURE ACROSS CENTRAL KANSAS. RICH MOISTURE AS MARKED BY
DEWPOINTS IN THE 60S DEG F EXTENDED ACROSS SOUTH CENTRAL KANSAS.
THIS MORNING:
THE MAIN ITEM OF CONCERN DURING THE MORNING PERIOD IS THE LIKELIHOOD
FOR DENSE FOG. HRRR AND MOS IS SUGGESTING THE GREATEST POTENTIAL FOR
DENSE FOG ACROSS WEST CENTRAL KANSAS THIS MORNING. THIS IS ALSO REFLECTED
IN 00Z NAM BUFKIT DATA. THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE
DEWPOINTS (LOW 50S DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A
WARM FRONT THAT WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
TODAY:
THE FOG SHOULD DISSIPATE/MIX OUT BY MID MORNING. THE REST OF THE SENSIBLE
WEATHER FOR TODAY WILL BE FAIRLY TRANQUIL. A BROAD UPPER LEVEL SHORTWAVE
TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS TODAY. SW KANSAS WILL BE
ON THE SOUTHEASTERN FRIDGES OF THE 400 HPA PV ANOMALY TODAY. AS A RESULT
OF THE AFOREMENTIONED UPPER LEVEL DYNAMICS SLIDING EAST THROUGH THE
DAY, THE RESULTANT SURFACE LOW WILL CONTINUE TO SLIDE TO THE EAST ACROSS
NORTHERN KANSAS AS WELL. A BIT OF DOWNSLOPE AND MIXING ACROSS THE SOUTHWESTERN
COUNTIES THIS AFTERNOON WILL PROVIDE VERY WARM TEMPERATURES NEAR THE
OKLAHOMA BORDER. EXPECT MID 80S DEG F IN THIS AREA. FURTHER NORTH, ONLY
LOOKING FOR UPPER 70S DEG F TO AROUND 80 DEG F AS A WEAK COLD FRONT
MOVES THROUGH EARLIER IN THE DAY. THE DRYLINE WITH UPPER 50S TO LOWER
60S DEG F DEWPOINTS WILL MIX EAST TODAY. THIS DRYLINE SHOULD BE LOCATED
ACROSS SOUTH CENTRAL KANSAS BY THIS AFTERNOON.
TONIGHT:
EVENTUALLY THE PACIFIC FRONT FOLLOWING BEHIND THE DRYLINE WILL CATCH
UP CLOSER TO THE DRYLINE. HAVE DISCOUNTED THE 00Z GFS SOLUTION AS THIS
MODEL SEEMS TO BE SUFFERING FROM BOUNDARY LAYER MOISTURE PROBLEMS AND
THE RESULTANT QPF LOOKS A LITTLE OVERZEALOUS. MAINLY STUCK WITH THE
00Z NAM AND 00Z WRF-NMM FOR POPS THIS EVENING. CONFINED POPS MAINLY ACROSS
SOUTH CENTRAL KANSAS AS TEMPERATURES IN THE 80S DEG F COMBINED WITH
NEAR 60 DEG F DEWPOINTS WILL CREATE ENOUGH SBCAPE IN THE 2000-2500 J/KG
RANGE SOUTH CENTRAL KANSAS. FORECAST SOUNDINGS SHOW CONSIDERABLE CINH
REMAINING ACROSS SC KS THROUGH MUCH OF THE DAY AND THEN FINALLY ERODING
BY TONIGHT. 0 TO 6 KM SHEAR OF AROUND 30 KT COULD SUPPORT THE NOTION
FOR MORE ORGANIZED CONVECTION ACROSS SE BARBER COUNTY. WILL HIGHLIGHT
THESE CONCERNS IN THE HWO. OTHER INFORMATION REGARDING CONVECTION CAN
BE FOUND IN THE SWODY1 PRODUCT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 328 AM CDT THU MAR 29 2012
A WEAK AREA OF HIGH PRESSURE WILL BUILD INTO WESTERN KANSAS EARLY
FRIDAY AS A COLD FRONT SINKS SOUTH INTO OKLAHOMA. THIS FRONT WILL
BECOME STATIONARY BY MID DAY AS AN UPPER LEVEL DISTURBANCE
EMBEDDED IN THE WEST NORTHWEST FLOW CROSSES INTO WESTERN KANSAS.
BOTH THE NAM AND GFS PLACES THE BETTER LATE DAY INSTABILITY
NEAR/JUST SOUTH OF THE OKLAHOMA BORDER WHICH IS ALSO WHERE THE
BETTER 850MB WARM AIR ADVECTION/ISENTROPIC LIFT IS FORECAST TO
IMPROVE AHEAD OF THIS UPPER WAVE. BASED ON THE LIFT,MOISTURE AND
INSTABILITY AT 00Z SATURDAY AHEAD OF AN UPPER LEVEL DISTURBANCE
WILL CONTINUE TO LEAN TOWARDS A DRY FORECAST FOR SOUTHWEST KANSAS.
DID HOWEVER KEEP THE 12 TO NEAR 15 PERCENT CHANCE OF PRECIPITATION
IN THE MEDICINE LODGE AND COLDWATER AREAS BASED ON HOW CLOSE THESE
LOCATIONS WILL BE TO THE MOISTURE/LIFT NORTH OF THE STATIONARY
FRONT EARLY FRIDAY NIGHT.
AS FOR TEMPERATURES...BASED ON 850MB TEMPERATURES AT 00Z SATURDAY
THE PREVIOUS FORECAST STILL LOOKS ON TRACK FOR HIGHS FRIDAY
AFTERNOON. DID HOWEVER LOWER TEMPERATURES IN SOUTHWEST KANSAS NEAR
THE OKLAHOMA BORDER BY A FEW DEGREES GIVEN THE BETTER CHANCES FOR
MORE CLOUD COVER IN THIS LOCATION FRIDAY AFTERNOON.
ONCE THIS SYSTEM MOVES EAST OF WESTERN KANSAS FRIDAY NIGHT A
WESTERLY DOWNSLOPE FLOW WILL THEN BEGIN TO DEVELOP. 24 HOUR 850MB
TEMPERATURE TRENDS OVER THE WEEKEND PERIOD SUPPORTS A NICE WARM
UP. 80S WILL BE LIKELY BOTH DAYS. A FEW LOCATIONS MAY EVEN
APPROACH 90 DEGREES ALONG AND SOUTH OF DODGE CITY IF THE 00Z
MONDAY 850MB TEMPERATURES FROM THE GFS AND ECMWF VERIFIES.
ON SUNDAY IT WILL ALSO BE WINDY AS A TIGHT SURFACE PRESSURE GRADIENT
DEVELOPS ACROSS WESTERN KANSAS IN RESPONSE TO AN AREA OF LOW
PRESSURE DEEPENING ALONG THE LEE OF THE ROCKIES. THIS DEEPENING
SURFACE LOW WILL THEN SLIDE EAST INTO WESTERN KANSAS SUNDAY NIGHT
AS AN UPPER LEVEL TROUGH EXITS THE ROCKIES AND MOVES OUT INTO THE
CENTRAL PLAINS. AN ELEVATED MIXED LAYER SHOULD INHIBIT
PRECIPITATION CHANCES ON SUNDAY AHEAD OF THIS NEXT SYSTEM. DRY AIR
MIXING DOWN TO THE SURFACE WILL INCREASE THE FIRE DANGER LEVELS
ACROSS WESTERN KANSAS...ESPECIALLY WEST OF THE DRY LINE.
A COLD FRONT WILL MOVE ACROSS WESTERN KANSAS EARLY MONDAY AS THIS
UPPER LEVEL TROUGH CROSSES INTO THE CENTRAL PLAINS. THE GFS
SUGGESTS SOME IMPROVING MID LEVEL INSTABILITY AS THE UPPER LEVEL
TROUGH CROSSES WESTERN KANSAS DURING THE DAY. BASED ON WHERE THE
BETTER MOISTURE RETURN WILL BE AHEAD OF THIS SYSTEM HAVE DECIDED
TO STAY CLOSE TO THE ALLBLEND ON PRECIPITATION CHANCES. THIS WOULD
PLACE A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS PORTIONS OF NORTH
CENTRAL KANSAS. AS FOR TEMPERATURES HAVE DECIDED TO FOLLOW THE
GENERAL 925-850MB TEMPERATURE TRENDS FROM THE GFS AND ECMWF. THIS
WOULD FAVOR HIGHS MAINLY IN THE 60S ON MONDAY AS THIS UPPER LEVEL
TROUGH PASSES.
A WARMING TREND WILL RETURN BY MID WEEK AS AN UPPER LEVEL RIDGE
CROSSES THE ROCKIES AND A WESTERLY DOWNSLOPE FLOW IMPROVES ACROSS
EASTERN COLORADO AND WESTERN KANSAS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1236 PM CDT THU MAR 29 2012
MVFR CIGS WILL OCCUR AROUND HAYS FOR A FEW HOURS THIS AFTERNOON.
INCREASED MIXING AND WINDS SHOULD HELP SCATTER THE CIGS OUT BY
21Z. A WEAK COLD FRONT MOVING THROUGH SOUTHWEST KANSAS WILL BRING
GUSTY NORTH TO NORTHWEST WINDS TO THE TAF SITES BETWEEN 19Z AND
21Z. WIND GUSTS OF 25 TO 30 KNOTS WILL BE POSSIBLE. THUNDERSTORMS
ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON OR EARLY EVENING ALONG
THE FRONT. THE FRONT SHOULD BE WELL TO THE SOUTHEAST OF DODGE CITY
BY THEN BUT WILL CARRY A TAF PERIOD WITH CB`S FROM AROUND 21Z TO 02Z.
&&
.FIRE WEATHER...
ISSUED AT 328 AM CDT THU MAR 29 2012
GUSTY SOUTHWEST WINDS WILL DEVELOP ON SUNDAY AS AN AREA OF LOW
PRESSURE DEEPENS ACROSS NORTHEAST COLORADO. SUSTAINED WINDS OF 20 TO
30 MPH WILL BE LIKELY. IN ADDITION AFTERNOON RELATIVE HUMIDITIES
ARE EXPECTED TO FALL BACK INTO THE TEENS WEST OF A DRYLINE WHICH
CURRENTLY IS EXPECTED TO EXTEND FROM NEAR SCOTT CITY TO GARDEN
CITY TO NEAR LIBERAL. THIS COMBINATION WILL RESULT IN VERY HIGH TO
CRITICAL FIRE WEATHER CONDITIONS ACROSS PORTIONS OF WESTERN KANSAS
SUNDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 83 48 78 51 / 10 10 10 10
GCK 82 47 77 51 / 0 10 10 0
EHA 81 46 76 51 / 0 10 10 0
LBL 85 47 77 49 / 0 10 10 10
HYS 79 47 79 50 / 0 10 10 0
P28 84 53 80 56 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GERARD
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
410 PM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD IN OVERNIGHT, ALLOWING FOR A
FREEZE ACROSS MANY LOCATIONS. THE CHANCE OF SHOWERS AND
THUNDERSTORMS WILL INCREASE FRIDAY AS LOW PRESSURE CROSSES THE
REGION. WEEKEND WEATHER WILL FEATURE ONLY LOW PRECIPITATION
CHANCES AND MODERATING TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A BROAD RIDGE ACROSS
THE UPPER MIDWEST WITH THE UPPER OHIO VALLEY IN A NORTHWESTERLY
FLOW AHEAD OF THIS FEATURE. AT THE SURFACE, A HIGH CENTERED
ACROSS ONTARIO EXTENDS SOUTHWARD INTO THE GREAT LAKES. A COLD
NORTHWESTERLY FLOW IN THE LOWER LEVELS CONTINUES TO ALLOW FOR
STRATOCUMULUS TO FILTER ACROSS AREAS NORTH OF THE PITTSBURGH
METRO. OTHERWISE, CLOUD DECK IS ERODING AND SKIES ARE CLEARING
FROM THE SOUTH.
TONIGHT...HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE GREAT
LAKES, WITH A LOBE OF HIGHER PRESSURE CENTERED ACROSS CENTRAL PA BY
DAWN ON FRIDAY. WITH SKIES CLEARING AND LIGHT WINDS, RADIATIONAL
COOLING WILL ALLOW TEMPS TO DROP BELOW FREEZING PRIMARILY
NORTHEAST OF PITTSBURGH. FURTHER SOUTHWESTWARD, TDS IN THE MID 30S
AND UPPER LEVEL CLOUDS MOVING IN FROM THE WEST WILL BE LIMITING
FACTORS AND KEEP TEMPS ABOVE FREEZING. THUS, NO CHANGES TO THE FREEZE
WARNING OVERNIGHT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
A SURFACE LOW ALONG WITH A WEAK SHORT WAVE WILL TRAVERSE ACROSS THE
OHIO VALLEY THROUGHOUT THE DAY ON FRIDAY. GFS/ECMWF SOLUTIONS
SUPPORT CHANCE POPS BEGINNING BEFORE NOON ON FRIDAY, AS
OVERRUNNING OCCURS AHEAD A WARM FRONTAL BOUNDARY APPROACHING FROM
THE SOUTHWEST. POPS INCREASE TO CATEGORICAL WITH THE SURFACE LOW
PROGGED TO REACH WESTERN PA BY 06Z ON SATURDAY. A FASTER AND MORE
NORTHERN TRACK WOULD INCREASE THE CHANCES OF SEVERE WEATHER ACROSS
THE AREA TOMORROW EVENING WITH THE NAM 4KM SUPPORTING CONVECTION
BECOMING LINEAR IN THE WARM SECTOR AHEAD OF THE COLD FRONT THAT
WILL SWING IN BEHIND THE LOW. FOR NOW, SEVERE THREAT IS JUST
MENTIONED IN THE HWO FOR EAST-CENTRAL OHIO WITH ANY LINEAR
CONVECTION THERE ANTICIPATED TO WEAKEN WITH THE LOSS OF HEATING AS
IT PUSHES ACROSS THE REMAINDER OF THE AREA.
CHALLENGING TEMPERATURE FORECAST FRIDAY AND FRIDAY NIGHT AS THE
FRONTAL BOUNDARY APPROACHES FROM THE SOUTHWEST AND THEN COLD AIR
ADVECTION BEGINS LATE FRIDAY NIGHT AS THE LOW PUSHES EAST OF THE AREA.
HIGHS 5 TO 10 DEGREES ABOVE SEASONAL NORMALS WILL BE REACHED IN THE
EVENING IN MANY LOCATIONS AS THE WARM SECTOR PUSHES INTO THE AREA.
FRIDAY NIGHT LOWS WILL RANGE FROM THE UPPER 40S ACROSS NORTH-
CENTRAL WV TO THE UPPER 30S NORTH OF PITTSBURGH.
SATURDAY AND SUNDAY...THE SURFACE LOW WILL PUSH OFF THE MID-
ATLANTIC COAST ON SATURDAY. WITH A NORTHWESTERLY MID-LEVEL FLOW AND COLD
AIR ADVECTION IN THE WAKE OF THE COLD FRONT. A FEW LINGERING
SHOWERS WILL CONTINUE EARLY ON INTO SATURDAY. MODEL THICKNESSES
WILL DECREASE TO SLIGHTLY TOO WARM FOR SNOW, SO PRECIP IS FORECAST
TO REMAIN ALL RAIN ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES FOR
NOW. HIGH PRESSURE WILL THEN BRIEFLY BUILD IN WITH A DRY
FORECAST SATURDAY INTO EARLY SUNDAY. THE NEXT FRONTAL BOUNDARY
WILL LIFT INTO THE AREA LATE ON SUNDAY AND RETURN THE CHANCE OF
SHOWERS. TEMPERATURES WILL BE NEAR NORMAL VALUES ON SATURDAY AND
WARM TO AROUND 15 DEGREES ABOVE NORMAL BY SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE EXTENDED PERIOD BEGINS WITH GOOD AGREEMENT ON THE ADVANCEMENT
OF AN UPPER RIDGE TOWARD THE AREA FOR THE START OF NEXT WEEK. AS
THIS OCCURS...A GOOD BIT OF WARMING SHOULD OCCUR ACROSS THE CWA AS
850 MB TEMPERATURES ON ALL GUIDANCE WARM INTO THE 10-14C RANGE BY
EARLY TUESDAY. TIMING DIFFERENCES AMONGST THE MODELS BECOME VERY
APPARENT BY THE TIME THE RIDGE IS TRAVERSING THE AREA ON MONDAY
WITH REGARD TO THE NEXT ORGANIZED PIECE OF ENERGY THAT SHOULD
AFFECT THE AREA THAT WILL BE LIKELY MOVING INTO THE SOUTHERN
PLAINS OR MID-MISSISSIPPI VALLEY BY THAT JUNCTURE. THE GFS/DGEX
COMBO IS FAR DEEPER AND ALSO CLOSED OFF WITH THE MID-LEVEL ENERGY
WITH THIS SYSTEM BY MONDAY...WHILE THE ECMWF PREFER A MORE OPEN
WAVE AND FASTER SOLUTION. THE RAMIFICATIONS OF THESE DIFFERENCES
BECOME APPARENT IN OUR FORECAST BY THE TUESDAY TO WEDNESDAY TIME
FRAME AS THE GFS LAGS THE ECMWF IN BRINGING PRECIPITATION INTO THE
AREA. ADDITIONALLY...THE GFS BECAUSE OF ITS MORE AMPLIFIED
SCENARIO ALSO BRINGS SIGNIFICANTLY WARMER AIR INTO THE CWA FOR A
LONGER DURATION AHEAD OF THE SYSTEM. WHILE THERE REALLY IS LITTLE
TO GO ON IN TERMS OF REAL DATA TO SELECT A MODEL PREFERENCE...THE
GEFS MEMBERS DO LEAN MORE TOWARD AN OPEN WAVE SOLUTION...WHICH
TENDS TO FAVOR THE ECMWF SOLUTION OVER THE OPERATIONAL GFS. AS A
RESULT...THE FORECAST LEANS A BIT TOWARD THE FASTER ECMWF
SOLUTION. HOWEVER...IT DOES NOT NEGLECT THE CLOSED/SLOWER GFS
SOLUTION...AS THE GFS HAS BEEN DEPICTING THE CLOSED SOLUTION FOR
AT LEAST A COUPLE OF CYCLES NOW.
WITH THE PASSAGE OF THE MAIN SYSTEM BY TUESDAY NIGHT...GOOD
AGREEMENT AGAIN EXISTS IN THE ESTABLISHMENT OF DEEP LAYER
NORTHWESTERLY FLOW OVER THE AREA. AS THIS OCCURS...SIGNIFICANTLY
COLDER AIR IS SET TO ARRIVE IN THE CWA BY NEXT FRIDAY NIGHT. JUST
AFTER THE END OF THE VALID PERIOD OF THE FORECAST AND ESPECIALLY
INTO NEXT WEEKEND...EARLY INDICATIONS ARE THAT 850 MB TEMPERATURES
COULD FALL OFF INTO THE -4 TO -8C RANGE OVER A GOOD CHUNK OF THE
FORECAST AREA. IF THIS WERE TO OCCUR IN THE AFOREMENTIONED
UNSTABLE NORTHWESTERLY FLOW...A TRANSITION TO A PERIOD OF SNOW
SHOWERS WOULD BE LIKELY...WITH SIGNIFICANTLY COLDER TEMPERATURES
THAN THOSE TO WHICH WE HAVE BECOME ACCUSTOMED. STAY TUNED. FRIES
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
CUMULUS HAS BEEN DEVELOPING ON THE PERIPHERY OF THE STRATUS FIELD
THAT HAS BEEN STUBBORNLY ADVANCING FROM THE NORTHWEST ACROSS THE
TAF SITES ALL MORNING. SOME BETTER MIXING IS EVIDENT IN THE
STRATUS LAYER...AS BREAKS ARE EVEN BECOMING APPARENT AROUND KPIT
AS OF 18Z. AS THE AFTERNOON CONTINUES...BREAKS IN THE STRATUS
SHOULD BECOME MORE COMMON...WHILE CUMULUS WILL CONTINUE TO DEVELOP
AROUND IT. FLOW IN THE MIXED LAYER SHOULD GRADUALLY WEAKEN AND
TURN MORE WESTERLY BY EARLY EVENING...WHICH SHOULD HELP TO BRING
SOME DRIER AIR OVER THE AREA...THAT ALONG WITH THE LOSS OF
AFTERNOON HEATING SHOULD HELP TO DISSIPATE BOTH THE STRATUS AND
CUMULUS OVER THE AREA. AS THIS OCCURS...WINDS SHOULD
DECOUPLE...AND WE WILL LIKELY BE LEFT WITH LIGHT WINDS AND
CLEARING SKIES FOR THE OVERNIGHT AND EARLY HALF OF FRIDAY.
OUTLOOK...FRIDAY THROUGH TUESDAY...
RESTRICTIONS ARE POSSIBLE FRIDAY AFTERNOON INTO SATURDAY DUE TO
SHOWERS AND LOW CLOUDS ASSOCIATED WITH PASSING EASTBOUND LOW
PRESSURE SYSTEM. EXPECT MAINLY VFR SUNDAY AND MONDAY BEFORE
ANOTHER SYSTEM ADVANCES FOR TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR MDZ001.
OH...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR OHZ041.
PA...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR PAZ007>009-
013>016-020>023-029-073>076.
WV...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION...UPDATED FOR 18Z TAFS
NWS TWIN CITIES/CHANHASSEN MN
1255 PM CDT THU MAR 29 2012
.DISCUSSION...ISSUED 317 AM CDT
TEMPERATURES THIS MORNING ARE FINALLY NEAR NORMAL IN A FEW
AREAS ESPECIALLY OVER WEST CENTRAL WISCONSIN WHERE SOME UPPER 20S
TO LOW 30S WERE NOTED...COURTESY OF HIGH PRESSURE AND CLEAR SKIES.
FREEZE WARNING LOOKS GOOD THIS MORNING. ELSEWHERE....INCREASING
MID LEVEL CLOUDS OVER NORTH DAKOTA AND NORTHWEST MINNESOTA IN ZONE
OF DEVELOPING WARM ADVECTION AND MID LEVEL THETA E ADVECTION.
A FEW RETURNS SHOWING UP IN THE REGION BUT SATURATION A FEW HOURS
AWAY YET. THE 06Z RUC SEEMS TO HAVE A DECENT TREND ON THE
INCREASING FGEN FORCING THIS MORNING FOR WEST CENTRAL MINNESOTA.
LOW LOWER LEVEL MOISTURE TRANSPORT STILL BOTTLED UP OVER THE
CENTRAL PLAINS. HAVE DELAYED POPS A BIT TODAY UNTIL THE WAVE OVER
EASTERN ID AND WESTERN WY GETS CLOSER ALONG WITH SOME OF THE
MOISTURE TRANSPORT REACHING IOWA. THE GFS AND NAM BOTH SHOW
PRECIPITABLE WATER VALUES REACHING JUST OVER AN INCH BY 00Z AT MSP
WHICH IS NEAR 2 STANDARD DEVIATIONS ABOVE NORMAL. HAVE RAISED POPS
BY EVENING INTO THE CATEGORICAL AREA OVER AT LEAST THE CENTRAL CWA
AND THEN FARTHER EAST INTO WISCONSIN LATER IN THE EVENING. THE GFS
IS A LITTLE FASTER WITH THE WAVE BUT NOT BY MUCH. MOST LINGERING
PRECIP SHOULD BE CONFINED TO A FEW AREAS OF WEST CENTRAL WISCONSIN
BY FRIDAY MORNING. BEST CHANCE OF ISOLATED THUNDER OVER WEST
CENTRAL MN THIS MORNING INTO THE AFTERNOON WITH THE INITIAL BURST
OF WARM ADVECTION AND THEN MAINLY SOUTHERN HALF OF THE CWA IN THE
AFTERNOON AND EVENING NEAR THE EDGE OF THE DEEPER INSTABILITY
TO UR SOUTH.
LOOKS LIKE LINGERING CLOUDS EASTERN AREAS FRIDAY INTO SATURDAY
MORNING WITH THE DEVELOPING STRONGER WARM FRONT. A LITTLE
CONCERNED ABOUT A FEW SHOWERS DEVELOPING LATER FRIDAY NIGHT AND
SATURDAY MORNING NEAR THE FRONT. WILL LEAVE OUT FOR NOW WITH THE
INITIAL DRIER BEHIND THE DEPARTING WAVE LATER TONIGHT.
STILL LOOKS WARM FOR THE WEEKEND...ESPECIALLY SUNDAY DEEP INTO THE
WARM SECTOR. MIXING DOWN FROM AROUND 875-900MB EVEN YIELDS SOME
LOWER 80S ON THE SOUTH. CHANCES FOR TSTMS LOOK SLIM WITH A CAPPED
ENVIRONMENT INITIALLY BUT SUNDAY NIGHT LOOKS BETTER EASTERN AREAS.
&&
.AVIATION.../18Z TAF ISSUANCE/
BAND OF -SHRA WITH SOME EMBEDDED TSTMS HAS BEEN MOVING NE 25 TO 30
KTS. LEADING EDGE OF THIS BAND RUNS FROM NEAR AXN TO JUST W OF BKX
TO 20W OF FSD. THEY LIE E OF N-S SFC TROF ACROSS THE CENTRAL DKTS
WITH RATHER SHARP MID LVL TROF ACRS THE CNTL DKTS PROVIDING
FAVORABLE VERTICAL MOTION. SB INSTABILITY RATHER WEAK WITH LOW SFC
DWPTS...BUT FAIRLY GOOD ELEVATED MOVING ACROSS AREA THIS
AFTN/EVENING WHICH WILL MAINTAIN A CHANCE OF A FEW TSTMS. AS SHWRS
EXIT AREA IN THE OVERNIGHT...WINDS BECOME LIGHT WITH WEAK TROFFINESS
ACROSS AREA. THIS WILL BRING A GOOD POTENTIAL OF STRATUS ACROSS
AREA WITH POSSIBLY SOME DZL IN THE EAST. CIGS MAY BE SLOW TO IMPROVE
WITH LGT NELY SFC WINDS IN THE MORNING.
MSP...SHWRS WILL APRCH MSP BY 00Z WITH PCPN THEN BECOMING LIKELY
UNTIL AROUND 06Z. ENUF ELEVATED INSTABILTY ACROSS AREA FOR A CHANCE
OF A TSTM EARLY IN THE EVENING. MID CLDS...BASES ARND 10K MOVING
INTO AREA DRNG ERLY/MID AFTN. BY 23Z BASES SHUD BE ARND 5K WITH MVFR
CIGS DVLPG DURING THE EVENINGIN PCPN. BY 09Z EXPECT IFR CIGS AS
STRATUS DEVELOPS WITH POSSIBLY DZL AROUND DAYBREAK. EXPECT MVFR BY
MID MORNING INTO MID AFTN BEFORE BECOMING VFR.
.FRI MORNING...IFR/MVFR CIGS. VFR BY AFTN.
.SAT MORNING...BR/FG POSSIBLE. OTHERWISE VFR.
.SUN.VFR.
.MON...MVFR SHRA/TSRA.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/BAP
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
310 PM CDT THU MAR 29 2012
.SHORT TERM...
ISSUED AT 204 PM CDT THU MAR 29 2012
(TONIGHT)
CONVECTION THAT HAS PERSISTED OVER NORTHWEST MISSOURI THE PAST
SEVERAL HOURS HAS SHOWN SLOW EAST SOUTHEASTWARD MOVEMENT IN THE
LAST HOUR OR TWO. THIS CONVECTION IS OCCURRING JUST NORTH OF A
WARM FRONT FROM THE KANSAS CITY METRO AREA TO SOUTH OF JEFFERSON
CITY. THIS FRONT WILL MOVE SLOWLY NORTH THE REST OF THE AFTERNOON
INTO TONIGHT IN RESPONSE TO THE TROUGH NOW MOVING EAST INTO THE
CENTRAL PLAINS. THE RUC IS SHOWING THAT THE BEST LOW LEVEL
MOISTURE CONVERGENCE WILL BE SHIFTING TO THE NORTHEAST WITH
TIME...SO WILL CONTINUE WITH SCT SHRA/TSRA BASICALLY ALONG AND
NORTH OF I-70 INTO EARLY THIS EVENING.
THEREAFTER...WARM FRONT WILL MOVE NORTH THIS EVENING. LOCAL VERSION
OF THE WRF AND GFS SHOWS 925-850MB MOISTURE CONVERGENCE MOVING
NORTH OF THE AREA THIS EVENING. MORE CONCENTRATED POTENTIAL FOR
ADDITIONAL THUNDERSTORMS WILL OCCUR AFTER MIDNIGHT AS A COLD FRONT
ASSOCIATED WITH THE AFOREMENTIONED TROUGH MOVES EASTWARD THROUGH
MISSOURI. HAVE KEPT LIKELY POPS OVER NORTHEAST MO/WEST CENTRAL IL
WHICH WILL BE CLOSEST TO THE TRACK OF THE ATTENDANT SURFACE LOW...
WITH SCATTERED THUNDERSTORMS TO THE SOUTH. MUCAPES IN THE 500-1000
J/KG RANGE AND DEEP LAYER SHEAR OF 30-40KTS SUGGEST THERE MAY
STILL BE A FEW STRONG STORMS CAPABLE OF PRODUCING HAIL AND GUSTY
WINDS INTO THE OVERNIGHT HOURS.
BRITT
&&
.LONG TERM...
ISSUED AT 309 PM CDT THU MAR 29 2012
(FRIDAY THROUGH THURSDAY)
GUIDANCE MOVES THE SURFACE LOW ACROSS NORTHERN ILLINOIS FRIDAY
MORNING WITH THE ATTENDANT WEAK COLD FRONT DROPPING THROUGH THE CWFA
INTO SOUTHERN MISSOURI BY 00-06Z SATURDAY. FORECAST SOUNDINGS ARE
INDICATING A WEAK CAP WITH MODEST INSTABILITY OF 1000-1500 J/KG.
CONVERGENCE ON THE FRONT DOESN`T LOOK VERY IMPRESSIVE...BUT THINK
SCATTERED THUNDERSTORMS WILL CONTINUE AS THE FRONT MOVES SOUTH.
WIND WILL QUICKLY SHIFT BACK TO THE SOUTH ON SATURDAY ALLOWING
TEMPERATURES TO ONCE AGAIN CLIMB INTO THE MID 70S TO LOW 80S. THE
GFS IS KICKING OUT A LITTLE OZARK-EFFECT DIURNAL CONVECTION LATE
SATURDAY AFTERNOON/EVENING AND THIS LOOKS REASONABLE GIVEN THE
PATTERN SO HAVE INCREASED POPS TO SLIGHT CHANCE ACROSS SOUTHERN
PORTIONS OF THE AREA. LOW LEVEL JET RAMPS UP LATE SATURDAY
NIGHT...ESPECIALLY ACROSS PARTS OF IOWA AND ILLINOIS AND BOTH THE
GFS AND NAM ARE PRINTING OUT PRECIP IN THOSE AREAS. LOW LEVEL
MOISTURE CONVERGENCE SIGNATURES ARE VERY BROAD AND COULD INDICATE
PRECIP ALMOST ANYWHERE IN EASTERN IOWA/WESTERN ILLINOIS. THINK SOME
RAIN IS LIKELY SOMEWHERE IN THAT AREA...BUT AM UNSURE WHAT THE
COVERAGE...STRENGTH...OR DURATION OF THE CONVECTION WILL BE. HAVE
THEREFORE DECIDED TO BE CONSERVATIVE AND ONLY INCREASED POPS TO
SLIGHT CHANCE THROUGH 12Z SUNDAY MORNING. WARM ADVECTION CONTINUES
SUNDAY WITH 850MB TEMPS BETWEEN 16-18C WHICH SHOULD EASILY PRODUCE
HIGHS IN THE LOW TO MID 80S ACROSS THE ENTIRE AREA...UNLESS THE
SATURDAY NIGHT CONVECTION IS STRONGER THAN ANTICIPATED AND COOLS THE
ATMOSPHERE OFF MORE THAN ANTICIPATED.
MEDIUM RANGE MODELS CONTINUE TO BRING A SHARP TROF OUT FROM THE
GREAT PLAINS ACROSS THE MIDWEST EARLY NEXT WEEK. WITH THE GULF OPEN
AND PLENTY OF MOISTURE AVAILABLE WE SHOULD SEE INCREASING COVERAGE
OF CONVECTION MONDAY AND MONDAY NIGHT AHEAD OF THE COLD FRONT
ASSOCIATED WITH THIS WAVE. ECMWF IS FASTER AND KEEPS AN OPEN WAVE
MOVING THROUGH THE AREA BY LATE MONDAY NIGHT WHILE THE GFS CLOSES
THE WAVE OFF AND HOLDS PRECIP BACK OVER THE AREA INTO TUESDAY
NIGHT. GEM IS MORE SIMILAR TO THE GFS...SO KEPT CHANCE POPS GOING
THROUGH TUESDAY BUT ENDED PRECIP TUESDAY NIGHT. TEMPERATURES WILL
FALL CLOSER TO CLIMATOLOGICAL AVERAGE BEHIND THE FRONT WEDNESDAY AND
THURSDAY.
CARNEY
&&
.AVIATION...
ISSUED AT 1250 PM CDT THU MAR 29 2012
COMPLEX OF THUNDERSTORMS OVER NORTHWEST MISSOURI IS MOVING SLOWLY
EASTWARD AND CURRENTLY BELIEVE THAT IT WILL STAY NORTH OF KCOU AND
THE ST. METRO ARE TAF SITES. IF THE SYSTEM DOES TURN SLIGHTLY
SOUTHEASTWARD AND MAINTAINS ITS STRENGTH...THEN AMENDMENTS WILL BE
REQUIRED FOR ALL OF THESE SITES TO INCLUDE TEMPO FOR TSRA. EXPECT
THERE WILL BE A PERIOD OF DRY WEATHER THIS EVENING BEFORE A COLD
FRONT APPROACHES THE AREA FROM THE WEST LATE TONIGHT AND EARLY
FRIDAY. HAVE ADDED VCSH WITH A CB GROUP TO ACCOMMODATE THE
POTENTIAL FOR SCATTERED THUNDERSTORMS MOVING ALONG THE FRONT.
WINDS IN THE ST. METRO AREA ARE CURRENTLY BEING INFLUENCED BY
DECAYING THUNDERSTORMS...BUT SHOULD TURN EASTERLY AND SLOWLY BACK
THROUGH THE TAF PERIOD.
SPECIFICS FOR KSTL...HAVE GONE INITIALLY WITH A DRY CONDITIONS
FOR THIS AFTERNOON. IF THE THUNDERSTORM COMPLEX TO THE NORTHWEST
OF KCOU HOLDS TOGETHER AND MOVES SLIGHTLY MORE SOUTHEAST...THEN IT
MAY AFFECT THE EVENING RUSH HOUR AFTER 23Z. OTHERWISE EXPECT
MAINLY DRY AND VFR CONDITIONS...THOUGH SCATTERED THUNDERSTORMS MAY
DEVELOP AHEAD OF A COLD FRONT THAT WILL MOVE THROUGH THE TERMINAL
LATE ON FRIDAY MORNING.
BRITT
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 59 77 53 79 / 40 40 10 10
QUINCY 56 73 50 78 / 60 50 10 10
COLUMBIA 60 76 54 81 / 50 30 10 10
JEFFERSON CITY 60 77 53 81 / 50 30 10 10
SALEM 55 77 50 74 / 20 30 10 10
FARMINGTON 58 77 52 80 / 20 30 10 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
204 PM CDT THU MAR 29 2012
.SHORT TERM...
ISSUED AT 204 PM CDT THU MAR 29 2012
(TONIGHT)
CONVECTION THAT HAS PERSISTED OVER NORTHWEST MISSOURI THE PAST
SEVERAL HOURS HAS SHOWN SLOW EAST SOUTHEASTWARD MOVEMENT IN THE
LAST HOUR OR TWO. THIS CONVECTION IS OCCURRING JUST NORTH OF A
WARM FRONT FROM THE KANSAS CITY METRO AREA TO SOUTH OF JEFFERSON
CITY. THIS FRONT WILL MOVE SLOWLY NORTH THE REST OF THE AFTERNOON
INTO TONIGHT IN RESPONSE TO THE TROUGH NOW MOVING EAST INTO THE
CENTRAL PLAINS. THE RUC IS SHOWING THAT THE BEST LOW LEVEL
MOISTURE CONVERGENCE WILL BE SHIFTING TO THE NORTHEAST WITH
TIME...SO WILL CONTINUE WITH SCT SHRA/TSRA BASICALLY ALONG AND
NORTH OF I-70 INTO EARLY THIS EVENING.
THEREAFTER...WARM FRONT WILL MOVE NORTH THIS EVENING. LOCAL VERSION
OF THE WRF AND GFS SHOWS 925-850MB MOISTURE CONVERGENCE MOVING
NORTH OF THE AREA THIS EVENING. MORE CONCENTRATED POTENTIAL FOR
ADDITIONAL THUNDERSTORMS WILL OCCUR AFTER MIDNIGHT AS A COLD FRONT
ASSOCIATED WITH THE AFOREMENTIONED TROUGH MOVES EASTWARD THROUGH
MISSOURI. HAVE KEPT LIKELY POPS OVER NORTHEAST MO/WEST CENTRAL IL
WHICH WILL BE CLOSEST TO THE TRACK OF THE ATTENDANT SURFACE LOW...
WITH SCATTERED THUNDERSTORMS TO THE SOUTH. MUCAPES IN THE 500-1000
J/KG RANGE AND DEEP LAYER SHEAR OF 30-40KTS SUGGEST THERE MAY
STILL BE A FEW STRONG STORMS CAPABLE OF PRODUCING HAIL AND GUSTY
WINDS INTO THE OVERNIGHT HOURS.
BRITT
&&
.LONG TERM...
ISSUED AT 328 AM CDT THU MAR 29 2012
(FRIDAY-WEDNESDAY)
KEPT POPS GOING FRI ALONG THE CDFNT MENTIONED ABOVE. AFTER THIS
SYSTEM MOVES OUT OF THE AREA...DRY CONDITIONS ARE FORECAST THRU
THE WEEKEND. IS SOME QUESTION ABOUT CHANCES FOR TSRA LATE SAT
NIGHT INTO SUN MORNING WITH RETURN FLOW SETUP AND DECENT LLJ OVER
THE AREA. HOWEVER...CHANCES ARE TOO LOW TO MENTION ATTM.
AFTER A BRIEF COOLER PERIOD EXPECTED ON FRI...CONTINUED A WARM
TREND FOR SAT WITH SLY FLOW RETURNING TO THE AREA.
FOR THE EXTD...PERIOD...AND APRIL...EXPECTED TO BEGIN WITH A VERY
WARM DAY. SOME GUIDANCE SUGGESTS TEMPS MAY BE NEAR RECORD HIGHS IN
THE UPPER 80S ACROSS MUCH OF THE REGION. HAVE NOT TRENDED THAT
WARM YET...BUT MDLS CONTINUE TO SUGGEST A VERY WARM PATTERN WITH
H85 TEMPS IN THE 16C TO 20C RANGE. THOUGHT A FORECAST GOING OVER
25 DEGREES ABOVE SEASONAL AVG WAS A GOOD START.
ECMWF/GFS HAVE COME INTO FAIRLY GOOD AGREEMENT FOR MON. WITH THE
GEM AS AN OUTLIER...HAVE TRENDED AWAY FROM THIS SOLN. WITH THE
ECMWF NOW ALSO SUGGESTING PRECIP ALONG THE CDFNT AS IT PUSHES THRU
THE REGION...HAVE RAISED POPS INTO THE CHANCE RANGE FOR MON INTO
MON NIGHT.
TRENDED TWD A GUIDANCE BLEND FOR TUES WITH A BRIEF PERIOD OF TEMPS
NEAR AVG BEFORE SW FLOW SETS UP AGAIN BY WED.
TILLY
&&
.AVIATION...
ISSUED AT 1250 PM CDT THU MAR 29 2012
COMPLEX OF THUNDERSTORMS OVER NORTHWEST MISSOURI IS MOVING SLOWLY
EASTWARD AND CURRENTLY BELIEVE THAT IT WILL STAY NORTH OF KCOU AND
THE ST. METRO ARE TAF SITES. IF THE SYSTEM DOES TURN SLIGHTLY
SOUTHEASTWARD AND MAINTAINS ITS STRENGTH...THEN AMENDMENTS WILL BE
REQUIRED FOR ALL OF THESE SITES TO INCLUDE TEMPO FOR TSRA. EXPECT
THERE WILL BE A PERIOD OF DRY WEATHER THIS EVENING BEFORE A COLD
FRONT APPROACHES THE AREA FROM THE WEST LATE TONIGHT AND EARLY
FRIDAY. HAVE ADDED VCSH WITH A CB GROUP TO ACCOMMODATE THE
POTENTIAL FOR SCATTERED THUNDERSTORMS MOVING ALONG THE FRONT.
WINDS IN THE ST. METRO AREA ARE CURRENTLY BEING INFLUENCED BY
DECAYING THUNDERSTORMS...BUT SHOULD TURN EASTERLY AND SLOWLY BACK
THROUGH THE TAF PERIOD.
SPECIFICS FOR KSTL...HAVE GONE INITIALLY WITH A DRY CONDITIONS
FOR THIS AFTERNOON. IF THE THUNDERSTORM COMPLEX TO THE NORTHWEST
OF KCOU HOLDS TOGETHER AND MOVES SLIGHTLY MORE SOUTHEAST...THEN IT
MAY AFFECT THE EVENING RUSH HOUR AFTER 23Z. OTHERWISE EXPECT
MAINLY DRY AND VFR CONDITIONS...THOUGH SCATTERED THUNDERSTORMS MAY
DEVELOP AHEAD OF A COLD FRONT THAT WILL MOVE THROUGH THE TERMINAL
LATE ON FRIDAY MORNING.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1251 PM CDT THU MAR 29 2012
.UPDATE...
ISSUED AT 1250 PM CDT THU MAR 29 2012
HAVE LEFT CHANCE POPS GOING BASICALLY NORTH OF INTERSTATE 70 FOR
THE REMAINDER TO THE AFTERNOON. CONVECTION OVER NORTHWEST
MISSOURI HAS ONLY RECENTLY SHOWN SOME SLOW EASTWARD PROPAGATION IN
THE LAST HOUR. THE RUC 925-850MB MOISTURE CONVERGENCE HAS HAD THE
BEST HANDLE ON THE DEVELOPMENT AND DEPICTS THAT IT WILL BE MOVING
NORTHEAST MO/WEST CENTRAL IL BY 00Z. HAVE ADJUSTED AFTERNOON
TEMPERATURES DOWNWARD BASED ON CLOUDS/RAIN CHANCES.
BRITT
&&
.SHORT TERM...
ISSUED AT 328 AM CDT THU MAR 29 2012
(TODAY-TONIGHT)
EXPECT ONGOING PRECIP TO GRADUALLY WEAKEN THIS MORNING ACROSS THE
AREA AND SHUD REFOCUS TO THE N AND W. THE EXACT TIMING OF THIS IS
ALSO UNCERTAIN...BUT EXPECT MOST OF THE CWA TO BE DRY BY NOON.
HOWEVER...CHANCES FOR TSRA SHUD INCREASE AGAIN THIS AFTERNOON
ALONG THE SFC WRMFNT. MDLS DIFFER EXACTLY WHERE THE WRMFNT WILL BE
LOCATED THIS AFTERNOON WITH THE NAM WITH A SRN OUTLIER SOLN.
BELIEVE THE NAM IS TOO FAR S...BUT THE ECMWF/GFS ARE LIKELY TOO
FAR N GIVEN THE CONVECTION THIS MORNING. HAVE TRENDED TWD A
COMPROMISE FCST WHICH IS CLOSE TO THE LOCAL WRF.
THIS WILL HAVE A LARGE IMPACT ON TEMPS FOR TODAY. TEMPS SHUD CLIMB
INTO THE 80S S OF THE FNT WHILE STRUGGLING TO REACH THE 70S
FURTHER N. TRENDED TWD THE WARMER MOS S OF THE FNT AND COOLER TO
THE N.
UNCERTAINTY REMAINS FOR PRECIP CHANCES TONIGHT. EXPECT PRECIP TO
DEVELOP AHEAD OF THE DEVELOPING SFC LOW ACROSS ERN KS THIS
AFTERNOON. THESE TSRA SHUD WEAKEN AS THE LOW APPROACHES THE
CWA...BUT BELIEVE THE NRN THIRD OF THE CWA WILL SEE TSRA TONIGHT.
STORMS MAY DEVELOP FURTHER S ALONG THE CDFNT AS IT MOVES THRU THE
REGION CLOSER TO SUNRISE FRI. CHANCES FOR THIS ARE LOWER AND JUST
HAVE LOW CHANCE POPS FOR NOW AS IS THERE IS ALSO A GREAT DEAL OF
UNCERTAINTY REGARDING TIMING OF THE FNT.
TILLY
&&
.LONG TERM...
ISSUED AT 328 AM CDT THU MAR 29 2012
(FRIDAY-WEDNESDAY)
KEPT POPS GOING FRI ALONG THE CDFNT MENTIONED ABOVE. AFTER THIS
SYSTEM MOVES OUT OF THE AREA...DRY CONDITIONS ARE FORECAST THRU
THE WEEKEND. IS SOME QUESTION ABOUT CHANCES FOR TSRA LATE SAT
NIGHT INTO SUN MORNING WITH RETURN FLOW SETUP AND DECENT LLJ OVER
THE AREA. HOWEVER...CHANCES ARE TOO LOW TO MENTION ATTM.
AFTER A BRIEF COOLER PERIOD EXPECTED ON FRI...CONTINUED A WARM
TREND FOR SAT WITH SLY FLOW RETURNING TO THE AREA.
FOR THE EXTD...PERIOD...AND APRIL...EXPECTED TO BEGIN WITH A VERY
WARM DAY. SOME GUIDANCE SUGGESTS TEMPS MAY BE NEAR RECORD HIGHS IN
THE UPPER 80S ACROSS MUCH OF THE REGION. HAVE NOT TRENDED THAT
WARM YET...BUT MDLS CONTINUE TO SUGGEST A VERY WARM PATTERN WITH
H85 TEMPS IN THE 16C TO 20C RANGE. THOUGHT A FORECAST GOING OVER
25 DEGREES ABOVE SEASONAL AVG WAS A GOOD START.
ECMWF/GFS HAVE COME INTO FAIRLY GOOD AGREEMENT FOR MON. WITH THE
GEM AS AN OUTLIER...HAVE TRENDED AWAY FROM THIS SOLN. WITH THE
ECMWF NOW ALSO SUGGESTING PRECIP ALONG THE CDFNT AS IT PUSHES THRU
THE REGION...HAVE RAISED POPS INTO THE CHANCE RANGE FOR MON INTO
MON NIGHT.
TRENDED TWD A GUIDANCE BLEND FOR TUES WITH A BRIEF PERIOD OF TEMPS
NEAR AVG BEFORE SW FLOW SETS UP AGAIN BY WED.
TILLY
&&
.AVIATION...
ISSUED AT 1250 PM CDT THU MAR 29 2012
COMPLEX OF THUNDERSTORMS OVER NORTHWEST MISSOURI IS MOVING SLOWLY
EASTWARD AND CURRENTLY BELIEVE THAT IT WILL STAY NORTH OF KCOU AND
THE ST. METRO ARE TAF SITES. IF THE SYSTEM DOES TURN SLIGHTLY
SOUTHEASTWARD AND MAINTAINS ITS STRENGTH...THEN AMENDMENTS WILL BE
REQUIRED FOR ALL OF THESE SITES TO INCLUDE TEMPO FOR TSRA. EXPECT
THERE WILL BE A PERIOD OF DRY WEATHER THIS EVENING BEFORE A COLD
FRONT APPROACHES THE AREA FROM THE WEST LATE TONIGHT AND EARLY
FRIDAY. HAVE ADDED VCSH WITH A CB GROUP TO ACCOMMODATE THE
POTENTIAL FOR SCATTERED THUNDERSTORMS MOVING ALONG THE FRONT.
WINDS IN THE ST. METRO AREA ARE CURRENTLY BEING INFLUENCED BY
DECAYING THUNDERSTORMS...BUT SHOULD TURN EASTERLY AND SLOWLY BACK
THROUGH THE TAF PERIOD.
SPECIFICS FOR KSTL...HAVE GONE INITIALLY WITH A DRY CONDITIONS
FOR THIS AFTERNOON. IF THE THUNDERSTORM COMPLEX TO THE NORTHWEST
OF KCOU HOLDS TOGETHER AND MOVES SLIGHTLY MORE SOUTHEAST...THEN IT
MAY AFFECT THE EVENING RUSH HOUR AFTER 23Z. OTHERWISE EXPECT
MAINLY DRY AND VFR CONDITIONS...THOUGH SCATTERED THUNDERSTORMS MAY
DEVELOP AHEAD OF A COLD FRONT THAT WILL MOVE THROUGH THE TERMINAL
LATE ON FRIDAY MORNING.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
342 PM CDT THU MAR 29 2012
.SHORT TERM...THROUGH FRIDAY. MAIN FORECAST CONCERN WILL BE
THUNDERSTORMS THIS AFTERNOON.
STRATUS HAS BEEN PERSISTENT ACROSS THE CENTRAL PART OF THE
FORECAST AREA MUCH OF THE DAY...WHILE THE NORTH AND SOUTH HAVE HAD
SOME CLEARING. THE LATEST TREND IN THE RADAR HAS SOME WEAK SHOWERY
TYPE PRECIPITATION FORMING UNDER THE STRATUS. THUNDERSTORMS THAT
HAD DEVELOPED IN NORTH CENTRAL NEBRASKA EARLIER HAVE DECREASED TO
WEAK SHOWERS. SURFACE ANALYSIS SHOWS THE SURFACE LOW IN CENTRAL
KANSAS WITH A BOUNDARY EXTENDING TO THE NORTH THROUGH THE FORECAST
AREA. THE BOUNDARY IS MORE OF A BROAD TROUGH THAN A REAL COLD
FRONT. WINDS SWITCH FROM EASTERLY TO NORTHERLY AS THE TROUGH GOES
PAST...BUT THE DRIER AIR AND WIND INCREASE IS FURTHER TO THE WEST.
THE UPPER LEVEL WAVE AND SURFACE BOUNDARY WILL CONTINUE TO MOVE
TO THE EAST. THEY WILL PUSH THROUGH THE EASTERN HALF OF THE
FORECAST AREA DURING THE REMAINDER OF THE AFTERNOON AND SHOULD BE
TO THE EAST BY EVENING. THE MODELS CONTINUE TO HAVE SOME SHOWERS
AND THUNDERSTORMS DEVELOP LATE THIS AFTERNOON AS THE FRONT MOVES
THROUGH THE AREA. THE 00Z 4KM WRF AND THE HRRR DEVELOP SOME
SHOWERS AND THUNDERSTORMS ALONG AND JUST BEHIND THE FRONT LATE
THIS AFTERNOON. WILL KEEP CHANCES FOR THUNDERSTORMS ACROSS THE
AREA...BUT THE BEST CHANCE WILL BE IN THE NORTHEAST WHERE THE
UPPER WAVE IS STRONGEST. MUCAPE IS 1500 TO 2000 J/KG SO THERE
COULD BE SOME STRONG TO SEVERE THUNDERSTORMS.
ONCE THE BOUNDARY MOVES TO THE EAST THE CHANCES FOR THUNDERSTORMS
DROPS OFF AND HAVE KEPT THE FORECAST DRY FOR THIS EVENING. THE
PRECIPITATION SHOULD BE TO THE EAST OF THE FORECAST AREA BY EVENING.
BY LATE TONIGHT A SURFACE HIGH PRESSURE SYSTEM BUILDS INTO THE AREA
AND SKIES BECOME MOSTLY CLEAR TO PARTLY CLOUDY. ON FRIDAY THERE IS
WARM ADVECTION SO THE TEMPERATURES SHOULD WARM UP FROM TODAY.
.LONG TERM...SATURDAY THROUGH THURSDAY.
FOR MUCH OF THE MID TERM PERIOD...SATURDAY AND SUNDAY...THE
CENTRAL PLAINS REMAIN CENTERED UNDER A WEAK RIDGE...WITH FAIRLY
ZONAL FLOW ACROSS THE REGION. NO PRECIPITATION IS EXPECTED THROUGH
THE MID TERM PERIOD. DECIDED TO BUMP UP TEMPERATURES SLIGHTLY BOTH
SATURDAY AND SUNDAY AS GUIDANCE IS A FEW DEGREES IN HIGHER IN BOTH
THE NAM AND THE GFS. 850 TEMPERATURES NEAR 20 DEGREES CELSIUS BOTH
DAYS SHOULD WARM UP THE AREA QUITE NICELY.
BEGINNING THE EXTENDED PERIOD SUNDAY NIGHT...AN UPPER LEVEL
TROUGH CONTINUES TO PUSH OFF THE WEST COAST TOWARDS THE COLORADO
ROCKIES. THE GFS IS DEEPER THAN THE NAM SOLUTION WITH THIS
TROUGH...WHILE BOTH MODELS SUGGEST SURFACE LOW PRESSURE STRETCHING
FROM THE WESTERN PORTION OF THE PLAINS INTO CANADA SUNDAY NIGHT.
AS THE PRESSURE SYSTEMS PUSH THROUGH THE REGION SUNDAY NIGHT INTO
MONDAY MORNING...BOTH MODELS SUGGEST THE POSSIBILITY FOR
THUNDERSTORM CHANCES OVERNIGHT AHEAD OF THE SURFACE BOUNDARY. THE
EC REMAINS THE FASTER OF THE TWO SOLUTIONS WITH THE FRONT
COMPLETELY THROUGH THE FORECAST AREA BY 12Z...WHILE THE GFS PUSHES
THE FRONT ABOUT HALFWAY THROUGH BY 12Z. THAT BEING SAID...BOTH
MODELS ARE SUGGESTING A VERY TIGHT PRESSURE GRADIENT BEHIND THE
FRONT AND PRESSURE RISES OF 15 TO 20 MB ACROSS THE FORECAST AREA.
THE MAIN CONCERN WILL BE WITH THE TIMING OF THE INCREASED WINDS
BEHIND THE FRONT...WHILE THE EC INCREASES WINDS BY THE 6Z TO 12Z
TIME RANGE...THE GFS LAGS A BIT BEHIND AND INCREASES WINDS TOWARDS
THE MORNING AND AFTERNOON HOURS ON MONDAY. SUSTAINED NORTHWEST
WINDS NEAR 25 TO 30 MILES PER HOUR WITH WIND GUSTS NEAR 30 TO 35
MILES PER HOUR CAN BE EXPECTED BEHIND THE FRONT. DRY AIR BEHIND
THE FRONT WILL HELP REDUCE DEWPOINTS ACROSS THE REGION...IN
COMBINATION WITH HIGHER WINDS ON MONDAY...RELATIVE HUMIDITY VALUES
WILL NEED TO BE WATCHED AS THEY ARE CURRENTLY FORECAST TO BE IN
THE LOWER 20S ACROSS THE WEST. SHOULD HIGH TEMPERATURES INCREASE
OR DEWPOINTS DECREASE JUST SLIGHTLY...FIRE WEATHER MAY BE A
CONCERN ON MONDAY AFTERNOON.
AS THE TROUGH TRIES TO PUSH OUT OF THE REGION MONDAY
EVENING...THE EC BEGINS TO BRING IN AN UPPER LEVEL RIDGE AND
SURFACE HIGH PRESSURE SYSTEM IMMEDIATELY FOLLOWING...WHILE THE GFS
TAKES A BIT SLOWER TO MOVE OUT AND PRODUCES A CUT OFF LOW AT THE
UPPER LEVELS AND A STRONGER SURFACE LOW ACROSS OKLAHOMA AND
ARKANSAS BEFORE PUSHING OUT OF THE REGION BY TUESDAY EVENING.
COOLER TEMPERATURES ARE EXPECTED ACROSS THE PLAINS BOTH MONDAY AND
TUESDAY WITH HIGHS IN THE 60S.
BOTH MODELS KEEP THE CENTRAL PLAINS UNDER AN UPPER LEVEL RIDGE
AND SURFACE HIGH THROUGH THE END OF THE LONG TERM WITH SOUTHERLY
WINDS AND HIGH TEMPERATURES IN THE LOW TO MID 70S WEDNESDAY AND
THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 1219 PM CDT THU MAR 29 2012/
AVIATION...18Z TAF. LOWER CLOUDS HAVE BEEN PERSISTING ACROSS THE
AREA BUT SHOULD START TO LIFT SOME THIS AFTERNOON. THUNDERSTORMS
ARE POSSIBLE THIS AFTERNOON AS A BROAD TROUGH OF LOW PRESSURE
MOVES THROUGH THE KGRI TERMINAL AREA. ONCE THE BOUNDARY MOVES TO
THE EAST THE CLOUDS WILL DIMINISH THIS EVENING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
615 PM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT EAST OF THE AREA TONIGHT. FRIDAY LOW
PRESSURE WILL MOVE ACROSS NORTHERN OHIO FROM THE WEST BRINGING A
THREAT OF SHOWERS AND THUNDERSTORMS TO THE REGION. HIGH PRESSURE
WILL BUILD INTO THE AREA LATE SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
NO CHANGES NEEDED FOR 630 PM UPDATE.
COMPLICATED FORECAST FOR TONIGHT WITH REGARD TO THE CURRENT
FROST/FREEZE HEADLINES. PERSISTENT STRATUS DECK CONTINUES TO ERODE
AND SHOULD LEAD TO SOME FAIRLY CLEAR SKIES FOR A WHILE TONIGHT.
SINCE TEMPS OVER MUCH OF THE EAST HALF OF THE AREA ALREADY NOT FAR
FROM THE FREEZING POINT...ANY CLEARING SHOULD SET THE STAGE FOR
FREEZING CONDITIONS TO OCCUR. THUS NOT CHANGES TO FROST/FREEZE
HEADLINES.
FIRST CONVECTIVE COMPLEX OVER IL IS WEAKENING AND WITH LOW LEVEL
DRIER FURTHER TO THE EAST NOT SEEING HOW THE HRRR MODEL CAN POSSIBLY
BE RIGHT WITH MEASURABLE PRECIP MOVING INTO THE SW PART OF THE AREA
BETWEEN 06Z AND 08Z.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
COMPACT SHORTWAVE TO MOVE QUICKLY THROUGH THE FLOW AND ACROSS THE
OHIO VALLEY FRIDAY. SOUTHWEST PART OF THE AREA IDENTIFIED IN A
SLIGHT RISK AREA FOR SEVERE THUNDERSTORMS. LOW CENTER SHOULD TRACK
WEST TO EAST ALONG U.S. ROUTE 30. GOOD PRECIP SHIELD EXPECTED
NORTH OF THE LOW TRACK TOO WITH EMBEDDED THUNDER...ACROSS
MI...LAKE ERIE/NRN OH...AND INTO NW PA. WILL HAVE CATEGORICAL POPS
FOR ALL. WILL HAVE A DECENT GRADIENT IN TEMPERATURE WITH ERIE
LIKELY HAVING A NORTHERLY COMPONENT WIND BY LATE IN THE DAY AND
THE WARM FRONT NOT MAKING IT MUCH FURTHER NORTH THAN MANSFIELD.
WILL HAVE UPPER 40S ACROSS THE EXTREME NORTHEAST AND MID 60S DOWN
AROUND MT VERNON. SHOWERS/THUNDERSTORMS SHOULD BE EAST OF THE I71
CORRIDOR BY 8PM. TEMPS WILL DROP BACK INTO THE 30S FRIDAY NIGHT.
QUESTION AS TO HOW MUCH SHOWERY ACTIVITY LINGERS ACROSS THE
EXTREME EAST SNOWBELT OVERNIGHT INTO SATURDAY MORNING.
SATURDAY HIGH PRESSURE WILL AGAIN NOSE SOUTH ACROSS THE GREAT
LAKES FROM CANADA INTO THE OHIO VALLEY WITH ONLY WEAK RIDGING
ALOFT. WILL HAVE SEASONABLE TEMPERATURES.
MODELS STRUGGLE WITH WHAT TO DO ON SUNDAY. WHILE IT LOOKS
WARMER...GFS AND NAM WANT TO TAKE A QUICK COLD FRONT ACROSS THE
AREA AND WILL SQUASH TEMPS SOMEWHAT ACROSS AT LEAST THE NORTHEAST.
WILL PUT IN A CHANCE OF SHOWERS AND HAVE A GRADIENT IN TEMPS FROM
AROUND 60 IN NW PA TO THE LOWER AND POSSIBLY MID 70S NEAR FINDLAY.
ECMWF DOES NOT HAVE MUCH OF THIS FEATURE AT ALL AND IS BUILDING
HEIGHTS/RIDGE AND REALLY WARMING THINGS UP.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
A FRONT WILL BE DRAPED ACROSS THE LOCAL AREA AT THE START OF
PERIOD. THERE COULD BE SOME LINGERING PRECIP ALONG THIS FEATURE BUT
NOT EXPECTING MUCH IN THE WAY OF QPF. WILL JUST MAINTAIN A SMALL
MENTION IN THE FORECAST. THE BIG STORY THE REMAINDER OF THE PERIOD
WILL BE A POTENT LOW THAT IS EXPECTED TO MOVE EAST ACROSS THE OHIO
VALLEY DURING THE MIDDLE PORTION OF THE WEEK. THE 12Z GUIDANCE IS
MUCH FURTHER SOUTH WITH THIS SYSTEM THAN THE MODELS WERE YESTERDAY.
STILL THINK THE LOCAL AREA WILL SEE PRECIP BUT HAVE BACKED OFF ON
TEMPS SOME FROM THE EARLIER PACKAGE. HIGH PRESSURE WILL REESTABLISH
ITSELF FOR THE END OF THE PERIOD WITH DRY WEATHER EXPECTED ON
THURSDAY. MONDAY WILL BE WARM WITH HIGHS MAINLY IN THE 70S. BY
WEDNESDAY AND THURSDAY TEMPS WILL BE BACK CLOSE TO NORMAL.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
STRATO CU DECK HAS OVERSPREAD ALL OF THE TAF SITES TODAY. DRIER
AIR WILL CONTINUE TO MOVE IN THE AREA AND SHOULD SEE THIS CLOUD
DECK ERODE FROM SW TO NE LATER THIS AFTERNOON. EXPECT ALL SITES
BUT KERI TO BE SCT BY 00Z. HIGH CLOUDS WILL MOVE IN FROM THE WEST
THIS EVENING AND BY MORNING EXPECT MID LEVEL CIGS MOST AREAS.
SHOWERS WILL REACH NW OH BY THE END OF THE PERIOD AS A WARM FRONT
SETS UP ACROSS THE REGION. NW TO N FLOW WILL BECOME NE BY EVENING AND
EASTERLY OVERNIGHT. SPEEDS FOR THE MOST PART WILL BE UNDER 10
KNOTS BUT SOME GUSTINESS POSSIBLE ON FRIDAY ESPECIALLY IN THE
SOUTH WHERE THE FLOW WILL TAKE ON A SOUTHERLY COMPONENT.
.OUTLOOK...NON VFR CONDITIONS LIKELY TO DEVELOP AGAIN ON FRIDAY
WITH SHOWERS THEN CONTINUE INTO SATURDAY.
&&
.MARINE...
SEVERAL SYSTEMS WILL BE MOVING ACROSS THE LAKE THROUGH THE SHORT
TERM PERIOD CREATING A RATHER UNSTABLE WIND PATTERN. HIGH PRESSURE
WILL REMAIN OVER THE LAKE TONIGHT. A WEAK SURFACE LOW IS PROGGED TO
MOVE ACROSS LAKE ERIE ON FRIDAY. THIS WILL CREATE A VARIABLE WIND
PATTERN WITH A MAINLY NORTH TO NORTHEAST FLOW OVER THE LAKE. HIGH
PRESSURE WILL BUILD ONCE AGAIN OVER THE LAKE ON SATURDAY. THE FLOW
WILL GRADUALLY SHIFT TO THE SOUTH IN ADVANCE OF A COLD FRONT ON
SUNDAY. THE CURRENT FORECAST MODELS SHOW SEVERAL STORM SYSTEMS
MOVING TOWARDS THE REGION FOR THE MIDDLE PART OF NEXT WEEK KEEPING
THE PATTERN UNSETTLED.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FROST ADVISORY FROM 2 AM TO 9 AM EDT FRIDAY FOR OHZ009>012-019-
028>030-036-037-047-089.
FREEZE WARNING FROM 2 AM TO 9 AM EDT FRIDAY FOR OHZ013-014-
020>023-031>033-038.
PA...FROST ADVISORY FROM 2 AM TO 9 AM EDT FRIDAY FOR PAZ001.
FREEZE WARNING FROM 2 AM TO 9 AM EDT FRIDAY FOR PAZ002-003.
MARINE...NONE.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...OUDEMAN/ADAMS
SHORT TERM...OUDEMAN
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...GARNET
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
144 PM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE PASSES TO THE NORTH LATE TODAY. LOW PRESSURE BRINGS
A WARM FRONT...THEN A COLD FRONT FRIDAY...THE LATTER WITH MORE
STORMS LATE FRIDAY. HIGH PRESSURE CROSSES SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
130 PM UPDATE...BUMPED MAX TEMPS UP A FEW DEGREES MAINLY IN THE
MOUNTAINS PER LATEST OBS. OTHERWISE...REMAINDER OF FORECAST ON TRACK.
PREVIOUS DISCUSSION...LATEST IR IMAGERY HAS CLEAR SKY FOR ENTIRE CWA
CURRENTLY. HOWEVER...LOW LEVEL MOISTURE ASSOCIATED WITH THE POST-FRONTAL
TROF TO OUR NORTH IS OOZING SOUTHWARD AND SHOULD BEGIN TO POOL UP AGAINST
THE NRN WV MOUNTAINS EVENTUALLY DEVELOPING OROGRAPHICALLY INDUCED CLOUDS
AND NOTHING MORE.
CURRENT WV IMAGERY SHOWING COPIOUS DRY AIR DIRECTLY OVER OUR
AREA...AND THIS IS HANDLED WELL IN THE RUC H5-H7 LAYER.
THIS...COMBINED WITH MORNING DAYTIME HEATING...SHOULD WORK TO
QUICKLY DISSIPATE THE LOW LEVEL CLOUDS THAT ARE CONTINUING TO
DEVELOP IN THE NRN WV MNTS CURRENTLY. OVERALL...A PLEASANT DAY IS ON
TAP WITH CLEAR SKY CONDITIONS AND TEMPERATURES RETURNING A LITTLE
CLOSER TO SEASONAL AVERAGE.
CLEAR SKY AND MODEST CAA EARLY TONIGHT WILL WORK TO BRING
TEMPERATURES DOWN IN THE NRN ZONES NEARING THE POINT OF FROST
DEVELOPMENT. AT THE SAME TIME...NEAR TERM MODELS HAVE BEEN SPEEDING
UP THE TIMING OF THE APPROACH OF THE NEXT WARM FRONT. 06Z NAM AND
03Z SREF MEAN HAS THETA-E GRADIENT EAST OF THE TUG FORK VALLEY AND
THE TRI-STATE AREA BY 12Z FRI. WITH THIS IN MIND...WILL NOT BE
ISSUING FROST ADVY FOR NRN ZONES WITH THIS ISSUANCE...BUT WILL
MENTION POSSIBILITY FOR PATCHY FROST IN WX GRIDS AND ZONES.
FOR REASONS MENTIONED ABOVE...HAVE SPED UP TIMING OF THE ONSET OF
CLOUD COVER AND POPS ASSOCIATED WITH WARM FRONT TOWARDS THE END OF
THE NEAR TERM. BY MID-DAY FRI...CWA SHOULD BE FIRMLY PLANTED IN THE
WARM SECTOR WITH TEMPS REBOUNDING QUICKLY.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
SHIFTED SAT SYSTEM TO FRI YESTERDAY...RESULTING IN AN ENTIRELY DRY
WEEKEND. NOW IT LOOKS LIKE WE MAY BE TAKING BACK SUNDAY.
FRI SYSTEM REMAINS ON TRACK AS EVEN ECMWF HAS COME AROUND TO THE
FASTER TIMING. NW-SE ORIENTED WARM FRONT...THEN THE WARM
SECTOR...THEN NE-SW ORIENTED COLD FRONT MARCH ACROSS IN A NICE
CLASSICAL SYNOPTIC SETUP. WORRIED PRECIPITATION COULD BREAK OUT
ALONG THE WARM FRONT FRI MORNING...WHICH IS MARKED BY WELL DEFINED
THETA E GRADIENT. WE COULD EVEN SEE A CONVECTIVE COMPLEX SIMILAR TO
WHAT IS GOING ON THIS MORNING OVER THE MIDWEST ALONG SAID GRADIENT.
AFTER A BREAK IN THE WARM SECTOR EARLY FRI AFTERNOON...SHOWERS AND
STRONG THUNDERSTORMS FIRE UP AHEAD OF THE COLD FRONT LATE FRI
AFTERNOON AND TRAVERSE THE AREA FROM NW TO SE THROUGH FRI EVENING.
THE THERMODYNAMIC AND KINEMATIC PARAMETERS LOOK SIMILAR TO THOSE
AHEAD OF THE COLD FRONT THAT TRAVERSED THE AREA LAST NIGHT...SO A
SIMILAR HAIL AND WIND THREAT IS ANTICIPATED. INSTABILITY LOOKS TO
BE GREATEST AS ONE MOVES SW ALONG FRONT...CLOSE TO MOISTURE SOURCE.
INDEED...SPC CONTINUES TO PEG WESTERN PORTIONS OF THE AREA FOR THE
SLIGHT RISK.
WILL KEEP HWO HAZARD AND RWS IMPACT FOR SEVERE THUNDERSTORMS
EMPHASIZING THE W.
COLD ADVECTION IN THE WAKE OF THE SYSTEM SAT WILL BE ACCOMPANIED BY
DEEPER MOISTURE COMPARED WITH TODAY...ALONG WITH SOME SUB FREEZING
LOW LEVEL TEMPERATURES...SO OPTED TO LEAVE SHOWER CHANCE IN THE
MOUNTAINS. ALSO LOTS OF STRATOCU ATOP MIXED LAYER THROUGHOUT THE
AREA.
THE CONUNDRUM SUNDAY IS A NW FLOW WARM ADVECTION FEATURE THAT MAY
AGAIN MATERIALIZE AS A CONVECTIVE COMPLEX. FOR NOW...JUST ADDED THE
SLIGHT CHANCE FOR SHOWERS IN CONCERT WITH NEIGHBORS TO THE N AND W.
THANKS ILN AND PBZ FOR COORD ON THIS CHANGE. WOULD NOT BE SURPRISED
TO SEE THIS BLOW UP INTO SOMETHING MORE IF THE GENERAL PATTERN
EVOLUTION HOLDS.
USED A CACOPHONY OF GUIDANCE BLENDS TO ARRIVE AT TEMPERATURES.
TRIED TO RAISE HIGHS FRI IN THE WARM SECTOR...ESPECIALLY SOUTHERN
AND CENTRAL PORTIONS OF THE AREA. LOWERED A LITTLE FRI NT THROUGH
SAT NT ALTHOUGH NAM12 SUGGESTS IT WILL BE EVEN COLDER. TRENDED
TEMPERATURES UP JUST A BIT SUN AND SUN NT.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
STILL HAVE A DEGREE OF UNCERTAINTY TO THE EXTENDED...PER
USUAL...RESULTING IN A BLEND COMING FROM HPC IN THE FORECAST GRIDS.
DID ADJUST SOME OF THE SKIES DURING THE EXTENDED PERIOD TO BETTER
MATCH UP WITH THE POPS IN THE FORECAST. OVERALL...LOOKING AT MORE
SEASONAL TEMPERATURES...AND DESPITE A COUPLE OF SYSTEMS IN THE LONG
TERM MODELS...OVERALL PRECIPITATION TO COME IN ON THE LOWER SIDE. DO
HAVE A COUPLE OF NIGHTS TOWARDS THE END OF THE PERIOD WHERE WE MAY
NEED TO BE CAREFUL OF FROST AND FREEZE GIVEN THE TRENDS IN THAT TIME
PERIOD WITH A DEEP TROUGH LIFTING OUT AND THE SKY TRYING TO
CLEAR...BUT AS OF NOW...NOTHING TO BE MENTIONED IN THE HWO OR RWS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
18Z THURSDAY THRU 18Z FRIDAY...GENERALLY VFR THROUGHOUT THE PERIOD.
LIGHT SURFACE WINDS WILL SLOWLY VEER TO THE SOUTH/SOUTHWEST BY THE
MORNING HOURS FRIDAY AS A WARM FRONT LIFTS NORTHWARD ACROSS THE
AREA. SHOWERS AND A FEW THUNDERSTORMS MAY ACCOMPANY THE FRONT BUT
NOT ENOUGH CONFIDENCE IN COVERAGE AT THIS POINT TO INCLUDE IN TAF.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: NONE
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z FRIDAY...IFR VISIBILITY MAY BE POSSIBLE IN STRONGER
STORMS LATE AFTERNOON AND EVENING FRIDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/TAX
NEAR TERM...50/TAX
SHORT TERM...TRM
LONG TERM...26
AVIATION...50/TAX
AREA FORECAST DISCUSSION
NWS NORMAN OK
328 PM CDT THU MAR 29 2012
.DISCUSSION...
WARM AND HUMID CONDITIONS WILL CONTINUE FOR THE NEXT SEVERAL DAYS
WITH A FEW OPPORTUNITIES FOR WIDELY SCATTERED SHOWERS AND STORMS.
RECENT HRRR RUNS/NAM12/GFS SIMILAR WITH DEVELOPMENT OF STORMS
ACROSS NORTHWEST OKLAHOMA LATE THIS AFTERNOON INTO THE EARLY
EVENING. STEEP LAPSE RATES AND FAIRLY WEAK MID-LEVEL FLOW WILL
FAVOR LARGE HAIL AND DAMAGING WINDS WITH THE STRONGER STORMS.
LOW AMPLITUDE WAVE WILL PROVIDE SOME SUPPORT...BUT STORM INTENSITY
SHOULD DECREASE BY MID EVENING.
A WEAK SURFACE BOUNDARY AND UPPER WAVE MAY PROVIDE ENOUGH LIFT
FOR ISOLATED/WIDELY SCATTERED SHOWERS AND STORMS MAINLY IN THE
LATE AFTERNOON/EARLY EVENING FRIDAY. OVERALL COVERAGE AND
ORGANIZATION APPEARS LOW.
MAINLY DRY CONDITIONS ARE EXPECTED FOR AT LEAST THE FIRST HALF
OF THE WEEKEND WITH LOW AMPLITUDE RIDGE OVER THE CENTRAL US.
MODELS BEGIN TO DIVERGE ON STRENGTH AND OVERALL TIMING WITH
ANOTHER TROUGH THAT IS FORECAST TO APPROACH THE SOUTHERN PLAINS
LATE SUNDAY INTO MONDAY. EC MODEL LESS AMPLIFIED AND FASTER WHICH
MATCHES CURRENT FORECAST. FOR NOW WILL FOLLOW FASTER SOLUTION
WHICH WILL PLACE BETTER CHANCES FOR STORM OVER EASTERN 1/3 OF
OKLAHOMA.
DRYLINE/COLD FRONT MAY BE DELAYED ENOUGH ON SUNDAY THAT HUMIDITY
LEVELS WILL REMAIN ABOVE 20-25 PERCENT ACROSS FAR WESTERN OKLAHOMA.
THIS SYSTEM WILL BRING IN SOMEWHAT COOLER AND DRIER AIR BY
MONDAY/TUESDAY OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 60 82 60 83 / 10 30 20 10
HOBART OK 58 85 57 83 / 20 20 20 0
WICHITA FALLS TX 60 88 59 87 / 10 30 20 0
GAGE OK 50 80 51 85 / 20 10 10 0
PONCA CITY OK 58 81 57 84 / 30 10 10 10
DURANT OK 61 81 60 83 / 10 30 20 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
333 PM CDT THU MAR 29 2012
.SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...ATMOSPHERE WAS PRETTY
WORKED OVER TODAY FROM LAST NIGHT/S CONVECTION WITH REMNANT MCV
NOTED ACROSS HGX CWA. LOW CLOUD DECK HAS BEEN SLOW TO MIX OUT
ACROSS BRUSH COUNTRY...BUT IS FINALLY STARTING TO DO SO AND ALL IN
ALL ATMOSPHERE IS GRADUALLY BECOMING MORE UNSTABLE AGAIN. PATTERN
LOOKS MORE LIKE MAY THAN MARCH WITH VORT MAXES TRAVERSING ACROSS
SOUTH TX IN THE MID LEVEL FLOW PRODUCING CONTINUING CHANCES OF
SHOWERS AND THUNDERSTORMS. OVER THE PAST HOUR CONVECTION HAS BEEN
TRYING TO FIRE ALONG THE SEABREEZE AS IT MOVES INLAND. THE
COMBINATION OF AN INCREASINGLY UNSTABLE AIRMASS AND AN AXIS OF
HIGHER PWATS DRAPED FROM SW TO NE ACROSS THE COASTAL PLAINS SHOULD
ALLOW ADDITIONAL CONVECTION TO DEVELOP ALONG THE SEABREEZE THROUGH
EARLY EVENING. ATTENTION THEN TURNS TO THE WEST WHERE CONVECTION
IS CURRENTLY DEVELOPING ACROSS HIGHER TERRAIN OF OLD MEX. HIRES
MODELS PROVIDE A VARIETY OF OUTPUT WITH 4KM WRF DEVELOPING
SIGNIFICANT CONVECTION ACROSS MUCH OF S TX THIS EVENING WHILE HRRR
IS MORE OF THE ISOLATED VARIETY. HRRR INITIALIZED MUCH BETTER THAN
4KM WRF SO HAVE LEANED MORE TOWARDS ITS OUTPUT FOR TONIGHT.
TRIMMED POPS SOME FOR TONIGHT OUT WEST BUT NOT AS DRY AS HRRR
GIVEN UNCERTAINTY. ANY STORMS THAT DEVELOP MAY BRIEFLY PULSE TO
STRONG/SEVERE LEVELS BUT WIDESPREAD SEVERE WX IS NOT CURRENTLY
ANTICIPATED. TOMORROW S TX IS PROG TO BE IN BETWEEN VORT MAXES AND
SHOULD GENERALLY BE DRY ASIDE FROM ISOLATED CONVECTION DEVELOPING
FROM DAYTIME MIXING AND INTERACTIONS WITH THE SEABREEZE. STRONGER
VORT MAX PROG TO APPROACH AREA FRI NIGHT WITH GOOD
PVA...INSTABILITY...AND MOISTURE TO EXIST FOR MCS FEATURE TO
POSSIBLY DEVELOP ALONG RIO GRANDE AND MOVE WEST THROUGH THE NIGHT.
STRONG WINDS AND HAIL MAY OCCUR IF MCS DEVELOPS BUT FINER DETAILS
TO COME IN FUTURE FORECASTS. TEMPS THROUGH THE SHORT TERM PERIOD
WILL BE DEPENDENT ON IF THEY BECOME RAIN COOLED AND HOW MUCH CLOUD
COVER DEVELOPS FROM CONVECTION. FOR NOW HAVE GONE GENERALLY WITH A
MOS BLEND.
&&
.LONG TERM (SATURDAY THROUGH THURSDAY)...EXPECT NOCTURNAL MCS TO BE
MOVING OUT OF THE FORECAST AREA BY THE START OF THE EXTENDED PERIOD.
HAVE ADDED 20 POPS TO THE FAR EAST TO ACCOUNT FOR TIMING OF THE
CONVECTION POSSIBLY LASTING INTO THE SATURDAY MORNING TIME PERIOD.
EXPECT TIMING WILL BE SIMILAR TO THE CONVECTION THE PAST TWO NIGHTS.
BY SATURDAY NIGHT LOOKS LIKE ALTHOUGH THUNDERSTORMS OVER THE SIERRA
MADRE ARE POSSIBLE...THE MOVEMENT SHOULD BE QUITE DIFFERENT THAN
OTHER NIGHTS HAVE BEEN AND WILL BE. CORFIDI VECTORS AND THICKNESS
CONTOURS WOULD INDICATE AN ALMOST DUE SOUTH MOVEMENT SO HAVE OPTED
TO TAKE PRECIP WORDING OUT OF THE FORECAST FOR SATURDAY NIGHT. COLD
FRONT STILL ON TRACK FOR MONDAY...WITH RATHER IMPRESSIVE MODEL
AGREEMENT FOR FOUR DAYS OUT. TIMING IS CLOSER TO THE SLOWER ECMWF
FROM YDAY RUNS AND HAVE STUCK MAINLY WITH THE ECMWF FOR THE FORECAST
THIS AFTERNOON. PRECIP CHANCES DO NOT LOOK GREAT AT THIS TIME...WITH
SLIGHT CHANCES IN THE EAST. BEHIND THE FRONT LOOK FOR A MODEST COOL
DOWN OF 5 TO 10 DEGREES FOR THE NEXT FEW DAYS WITH DRIER CONDITIONS
AND MOSTLY CLEAR SKIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 67 86 68 86 68 / 20 20 30 20 10
VICTORIA 67 84 67 84 68 / 30 20 20 20 10
LAREDO 68 92 69 93 69 / 40 20 50 10 10
ALICE 68 89 66 89 68 / 30 20 40 10 10
ROCKPORT 69 82 69 80 70 / 20 20 20 20 10
COTULLA 67 86 65 88 67 / 40 20 50 10 10
KINGSVILLE 68 87 68 88 67 / 30 20 30 20 10
NAVY CORPUS 71 81 68 82 69 / 20 20 20 20 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
SHORT TERM...HART/79
LONG TERM...ZABEL/83
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1131 AM CDT THU MAR 29 2012
.UPDATE...
AFTER A BRIEF FLIRTATION WITH MOISTURE ON THE CAPROCK THIS
MORNING...THE DRYLINE IS STARTING TO JUMP EAST. WEST TEXAS MESONET
OBS SHOW DEWPOINTS DROPPING QUICKLY ACROSS THE WEST. WINDS ARE
EVEN VEERING IN THE ROLLING PLAINS WHICH IS A BIT CONCERNING FOR
HOLDING ON TO SUFFICIENT MOISTURE FOR OUR AFTERNOON TSTM
CHANCES...BUT LATEST GUIDANCE STILL DEPICT THE WIND TO START TO BACK
ACROSS THE ROLLING PLAINS BY 21Z WHICH SHOULD PUT A QUICK STOP TO
THE DRYLINE/S EASTWARD PROGRESS. BETWEEN 21-0Z...THE QUASI-
STATIONARY DRYLINE SHOULD BE LOCATED ROUGHLY FROM HALL COUNTY TO
KENT COUNTY...BULGING SLIGHTLY EAST IN DICKENS AND MOTLEY
COUNTIES. ATMOSPHERE SHOULD BECOME NEARLY UNCAPPED DURING THIS
PERIOD WITH SFC TEMPS APPROACHING 90F. AROUND THE SAME TIME...WE
SHOULD BEGIN TO SEE INCREASING LARGE-SCALE ASCENT AS A SHORTWAVE
APPROACHES FROM THE WEST...ALTHOUGH THIS WILL BE BE PRIMARILY
FOCUSED TO OUR NORTH. CAPE-SHEAR COMBINATION WILL LIKELY SUPPORT
AN ISOLD THREAT OF SVR WIND AND HAIL ACROSS A LIMITED
AREA...MAINLY ERN HALL...CHILDRESS AND ERN COTTLE
COUNTIES...DEPENDING ON JUST WHERE EXACTLY THE DRYLINE ENDS
UP. MOST OF THE HIGH-RES GUIDANCE SUGGESTS THAT CAP WILL HOLD
UNTIL VERY LATE IN THE AFTERNOON OR POSSIBLY EARLY EVENING...ABOUT
23-01Z RANGE. IT MAY BREAK FIRST ACROSS THE ERN PANHANDLE WHERE
LOW-LVL CONVERGENCE WILL BE MAXIMIZED.
SO...EXCEPT FOR SOME MINOR ADJUSTMENTS THE BULK OF THE FCST LOOKS TO
BE ON TRACK WITH A 15-20 POPS STILL LOOKING VALID ALONG/EAST OF
THE DRYLINE.
&&
.PREV DISCUSSION... /ISSUED 641 AM CDT THU MAR 29 2012/
AVIATION...
A MODEST LOW LEVEL WIND MAXIMUM AROUND 35 KTS AT 800 FT ABOVE THE
GROUND CONTINUED OVER THE CENTRAL SOUTH PLAINS NEAR KLBB ACCORDING
TO THE HIGH RESOLUTION REESE CENTER SODAR FROM THE WEST TEXAS
MESONET. THE CURRENT RUC RUN SHIFTS THIS MAX TO THE NORTHEAST
BETWEEN 13Z AND 14Z THIS MORNING ABOUT AS MIXING OUT BEGINS.
SHALLOW LOW LEVEL MOISTURE WAS MORE NOTABLE WITH A PATCH OF
STRATUS FORMING NEAR KHOB AND THE LEADING EDGE OF A LARGE AREA OF
STRATUS NEAR KABI. SOME CHANCE THAT WE COULD SEE AN LIFR CIG FORM
NEAR EITHER KCDS OR KLBB OVER THE NEXT FEW HOURS BUT OVER-ALL RISK
SEEMS TOO LOW FOR INCLUSION IN THE TAF. WE DID HOLD ON TO MINOR
VISIBILITY RESTRICTIONS...HOWEVER...THROUGH 14Z. BY LATE MORNING
EXPECT DRIER SOUTHWEST BREEZES TO DOMINATE KLBB WHILE A DRY-LINE
WILL BE IN POSITION NEAR KCDS. APPROACH OF AN UPPER LEVEL TROUGH
LATER TODAY COULD BREAK CAP AND ALLOW HIGH-BASED THUNDERSTORMS NOT
FAR FROM KCDS. RETAINED CB MENTION AT KCDS LATER TODAY. RMCQUEEN
PREV DISCUSSION... /ISSUED 514 AM CDT THU MAR 29 2012/
SHORT TERM...
A FULL-LATITUDE UPPER LEVEL TROUGH WILL SWING EAST FROM THE ROCKIES
INTO THE NORTHERN AND CENTRAL HIGH PLAINS LATE THIS AFTERNOON AND
EVENING. SOMEWHAT ENHANCED LOW LEVEL WEST TO SOUTHWEST FLOW SHOULD
DEVELOP ON THE CAPROCK AND HELP TIGHTEN A DRY-LINE OVER THE ROLLING
PLAINS...PERHAPS DIRECTLY ADJACENT TO THE CAP-ROCK. PRIMARY UPWARDS
FORCING WILL OCCUR TO THE NORTH...BUT WE MAY SEE ENOUGH LIFT WITH A
MODESTLY UNSTABLE AIRMASS TO BREAK THE CAP AND ALLOW DEVELOPMENT OF
A FEW HIGH-BASED STORMS ALONG THE DRY-LINE. SOME THREAT FOR ENTIRE
DRY-LINE TO ERUPT BUT FORCING WEAKER HEADING SOUTHWARD AS WELL.
SEVERE THREAT FROM STORMS WILL BE HIGHEST AS WELL OVER NORTHERN
ROLLING PLAINS WITH STRONG WINDS GREATEST RISK. WE TRIMMED THUNDER
CHANCES A BIT MORE TO THE EAST WITH SOLUTIONS FAVORING THE DRY
SCENARIO ON THE CAPROCK TODAY WHILE EXPANDING LOW CHANCE MENTION
THIS EVENING OVER THE NORTHERN ROLLING PLAINS. THUNDER CHANCES WILL
DIMINISH LATER TONIGHT WHILE A COLD FRONT SHOULD SETTLE SOUTHWARD
OUT OF THE PANHANDLE INTO NORTHERN ZONES LATER TONIGHT. VERY WARM
TEMPERATURES FAVORED AGAIN TODAY WITH MINOR CHANGES. RMCQUEEN
LONG TERM...
LOW AMPLITUDE RIDGING WILL RETURN TO THE AREA ON FRIDAY BEHIND A
MINOR DISTURBANCE PASSING OVERHEAD AROUND MID-DAY. THIS RIDGING
WILL PERSIST UNTIL EARLY SUNDAY MORNING WHEN A RETURN TO ENHANCED
SOUTHWESTERLY FLOW COMES ON SUNDAY AHEAD OF A POTENT STORM SYSTEM
DIVING DOWN THE WEST COAST. GUIDANCE CONTINUES TO SLOW THE
PROGRESSION OF THE SYSTEM WHICH WILL HELP THE WIND/FIRE WEATHER
POTENTIAL TO SOME EXTENT THOUGH BOTH WIND SPEEDS AND FIRE DANGER WILL BE
ENHANCED. BY MONDAY MORNING NVA WILL SET IN WITH A RETURN TO
RIDGING FOR MID-WEEK.
QUESTION WILL BE IF THIS HAS MUCH CHANCE AT ALL AT INITIATING
CONVECTION ACROSS THE AREA FOR FRIDAY...GIVEN THE TRENDS THIS
WEEK...TSTM CHANCES REMAIN QUITE LOW...ACTUALLY...TOO LOW FOR A
MENTION IN THE GRIDS. THUS WILL CONTINUE WITH A POP FREE FORECAST
FOR THE ENTIRE EXTENDED. OF NOTE THOUGH ON FRIDAY WILL BE A WEAK
COLD FRONT WHICH IS PROGGED TO ENTER AT LEAST THE NORTHERN ZONES.
THIS WOULD UNDOUBTEDLY PLAY HAVOC WITH AFTERNOON HIGHS. THE
BOUNDARY IS TRENDING FURTHER SOUTH THAN EVIDENT FOR THE LAST FEW
NIGHTS AND THUS...WILL BLEND TEMPS DOWNWARD SOMEWHAT ACROSS THE
NORTH FRIDAY AFTERNOON. DRYLINE WILL REMAIN EAST OF THE AREA FOR
MUCH OF THE REST OF THE EXTENDED. WINDS STILL LOOK TO BE QUITE BREEZY ON
SUNDAY WITH AN ATTENDANT FIRE WEATHER THREAT DUE TO THE DRY NATURE
OF THE LOWER ATMOSPHERE. SUNDAY H7 GRADIENTS OF 60M/200NM WILL
LIKELY PUSH US INTO WIND ADVISORY TERRITORY AND IF TRENDS DO NOT
CHANGE WITH VIGOR...A RED FLAG PRODUCT AS WELL. COLD FRONT DUE IN
SUNDAY NIGHT WILL BRING GUSTY WINDS IN ITS WAKE AND THESE WINDS
MAY VERY WELL BRING ADVISORY WINDS TO THE AREA THROUGH MONDAY AS A
VERY TIGHT PRESSURE GRADIENT OVERSPREADS THE AREA. AFTER THE WINDS
DIE DOWN LATE MONDAY...QUIESCENT WEATHER RETURNS TO THE SOUTHERN
PLAINS.
FIRE WEATHER...
UPPER TROUGH PASSING EAST FROM THE ROCKIES INTO THE CENTRAL AND
NORTHER HIGH PLAINS THIS AFTERNOON AND EVENING SHOULD LEAD TO
ENHANCED DOWNWARD FORCING ACROSS CENTRAL AND WESTERN SOUTH PLAINS
WITH DEEPER MIXING INTO SOMEWHAT STRONGER WEST-SOUTHWEST FLOW ALOFT.
THIS SHOULD BE ENOUGH FOR MARGINAL WINDS TO ENHANCE FIRE WEATHER
RISK ALONG WITH VERY DRY AIRMASS AND TEMPERATURES WELL ABOVE NORMAL.
GREEN-UP RECENTLY CERTAINLY HAS LESSENED FUELS THREAT FOR MANY AREAS
CENTRAL AND EAST...PROBABLY LESS SO IN THE WEST. FIRE DANGER WAS
RATED HIGH ON WEDNESDAY AND WILL NOT BE ANY LESS TODAY. ANYWAY...
ENOUGH OF A MARGINAL RISK TODAY TO INCLUDE A FIRE DANGER STATEMENT
FOR AREAS ON THE CAP-ROCK THIS AFTERNOON AND EARLY THIS EVENING.
RMCQUEEN
DRY SURFACE CONDITIONS WILL CONTINUE THE REST OF THE WEEK LEADING TO
INCREASING FUEL VOLATILITY ACROSS THE REGION ESPECIALLY IN THE WEST
WHERE GREEN-UP HAS BEEN SLOW DUE TO A LACK OF MOISTURE. SATURDAY
MAY SEE ANOTHER RANGELAND FIRE DANGER DAY WITH MIN RH
VALUES NEAR 10 PCT. SUNDAY HAS PROSPECTS TO BE A CRITICAL FIRE
WEATHER DAY AS WINDS OF 20-30MPH COMBINE WITH MIN RH VALUES NEAR
10 PCT. H8 THERMAL RIDGE NOW PROGGED TO BE ORIENTED FROM THE BIG
BEND INTO WESTERN KANSAS WHILE H5 SPEED MAX WILL LIE ACROSS
CENTRAL NEW MEXICO. THIS POINTS TO THE MOST SIGNIFICANT THREAT
NEAR THE TX/NM STATE LINE. THE THREAT MAY PERSIST OVERNIGHT
WITH LITTLE RECOVERY AND BREEZY CONDITIONS. A COLD FRONT IS DUE IN
SUNDAY NIGHT AND WINDS BEHIND THE FRONT OF 25 TO 35 MPH MAY HAMPER
EFFORTS ON ANY FIRES WHICH MAY INITIATE. THESE WINDS LOOK TO
PERSIST WELL INTO MONDAY BEFORE SUBSIDING MONDAY NIGHT. THE
LATE WEEKEND SYSTEM CERTAINLY CONTINUES TO WARRANT CAREFUL
MONITORING.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 86 45 80 47 86 / 0 10 10 10 0
TULIA 87 47 78 51 87 / 10 10 10 10 0
PLAINVIEW 87 47 80 51 88 / 10 10 10 10 0
LEVELLAND 88 48 84 52 89 / 10 10 10 10 0
LUBBOCK 89 49 84 52 89 / 10 10 10 10 0
DENVER CITY 87 49 87 52 89 / 10 10 10 10 0
BROWNFIELD 89 50 87 53 90 / 10 10 10 10 0
CHILDRESS 91 55 82 55 89 / 20 30 10 10 0
SPUR 90 54 86 56 91 / 20 20 10 10 0
ASPERMONT 88 58 90 60 91 / 20 20 10 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33/93
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
347 PM CDT THU MAR 29 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
346 PM CDT THU MAR 29 2012
AT 3 PM...A SHORT WAVE TROUGH WAS PRODUCING A CLUSTER OF
THUNDERSTORMS ACROSS SOUTHERN IOWA AND NORTHERN MISSOURI.
FURTHER TO THE WEST OVER THE CENTRAL AND NORTHERN PLAINS...
THERE WERE TWO ADDITIONAL SHORT WAVE TROUGHS. THE 29.12Z
MODELS ARE IN FAIRLY GOOD AGREEMENT THE SHORT WAVE OVER THE
NORTHERN PLAINS WILL MOVE ACROSS NORTHERN MINNESOTA AND
WESTERN ONTARIO TONIGHT. MEANWHILE THE SECOND SHORT WAVE
/CURRENTLY OVER THE CENTRAL PLAINS WILL EAST SOUTHEAST
ACROSS IOWA AND MISSOURI TONIGHT AND FRIDAY. AS A RESULT...
THE BEST FORCING WILL BE TO THE NORTH AND SOUTH OF THE
FORECAST AREA TONIGHT. EVEN THOUGH THIS WILL BE THE CASE...
THE 850 MB JET WILL FOCUS MODEST MOISTURE TRANSPORT INTO THE AREA
FOR LATE THIS EVENING AND OVERNIGHT. AS A RESULT...THE AREA WILL
SEE ANYWHERE FROM A QUARTER TO A HALF INCH OF RAIN AS THESE
SYSTEMS MOVE THROUGH THE REGION. IN AREAS WHERE THE FORCING IS
BETTER PRECIPITATION TOTALS WILL LIKELY RANGE FROM A HALF TO ONE
INCH. THE MODELS CONTINUE TO INDICATE THAT THERE WILL BE SOME
ELEVATED CAPES /UP TO 200 J/KG MOVING ACROSS THE AREA FROM LATE
THIS EVENING INTO THE OVERNIGHT. THIS SHOULD BE ENOUGH TO KEEP THE
ISOLATED THUNDERSTORMS IN THE FORECAST. IN ADDITION...THE MODEL
SOUNDINGS ACROSS TAYLOR AND NORTHERN CLARK COUNTIES SHOW THAT
THERE WILL BE AN ELEVATED WARM LAYER /UP 2C/ BETWEEN 900 MB AND
750 MB WITH A COLD LAYER BELOW. THIS WILL BE DEEP ENOUGH TO
REFREEZE ANY SNOW THAT MELTED IN THE WARM LAYER AFTER MIDNIGHT. AS
A RESULT...WENT WITH A MIX OF RAIN...SLEET...AND SNOW FOR THESE
COUNTIES. WITH THE SURFACE TEMPERATURES AND SOILS UNUSUALLY
WARM...NOT EXPECTING ANY ACCUMULATIONS OF SNOW OR SLEET FROM THIS
SYSTEM.
ON FRIDAY...THE MODELS ARE INDICATING THAT THERE WILL BE A
CHANCE OF LIGHT RAIN OR DRIZZLE ACROSS WISCONSIN DURING THE
MORNING. ADDITIONAL RAINFALL AMOUNTS WILL LIKELY ONLY RANGE
FROM A TRACE TO A FEW HUNDREDTHS OF AN INCH. LIKE THE PAST
COUPLE OF DAYS...THE MODELS CONTINUE TO SHOW THAT EAST WINDS OFF
OF THE GREAT LAKES WILL BRING MUCH COOLER TEMPERATURES INTO THE
REGION. TEMPERATURES ACROSS MUCH OF EASTERN WISCONSIN WILL LIKELY
ONLY GET INTO THE 40S. MEANWHILE TEMPERATURES IN SOUTHEAST
MINNESOTA AND NORTHEAST IOWA WILL BE MAINLY IN THE 60S.
ON FRIDAY NIGHT...IT CONTINUES TO LOOK LIKE A SURFACE HIGH
WILL BUILD ACROSS NORTHERN AND EASTERN WISCONSIN. THIS HIGH
WILL RESULT IN LIGHT AND VARIABLE WINDS AND ALLOW THE
TEMPERATURES TO FALL OFF INTO THE MID 30S ACROSS NORTH-CENTRAL
AND CENTRAL WISCONSIN. IF SKIES HAPPEN TO CLEAR OFF MORE THAN
EXPECTED...THESE TEMPERATURES MAY FALL TO AROUND 30. FOR THE
TIME BEING...JUST MENTIONED THE POSSIBILITY OF FROST IN THE
GRIDS TO COVER THIS POTENTIAL.
ON SATURDAY AFTERNOON AND NIGHT...A WARM FRONT WILL BE LOCATED
ACROSS NORTHERN IOWA AND NORTHERN ILLINOIS. THE MODELS THAT
THE 850 MB JET WILL BRING SOME MODEST MOISTURE TRANSPORT INTO
NORTHEAST IOWA AND SOUTHWEST WISCONSIN. THE NAM/WRF IS THE
MOST ROBUST AND THE FASTEST AT GENERATING PRECIPITATION ACROSS
THIS AREA. MEANWHILE THE OTHER MODELS SUGGEST THAT THE BETTER
CHANCES WILL BE ON SATURDAY EVENING. WITH MEAN LAYER CAPES
CLIMBING INTO THE 500 TO 1000 J/KG RANGE...THERE WILL BE THE
POTENTIAL OF SOME THUNDERSTORMS. THE MODELS SHOW 0-6KM SHEAR
IN THE EXCESS OF 40 KNOTS. HOWEVER WITH MUCH OF THE SHEAR LOCATED
BELOW THE INVERSION...THERE IS SOME CONCERN THAT THE MODELS MAY BE
OVERDOING THE SHEAR AVAILABLE FOR THESE THUNDERSTORMS. THIS AREA
IS CURRENTLY UNDER SEE TEXT FOR DAY 3 AND WILL HAVE TO BE WATCHED
OVER THE NEXT TWO DAYS. IF SEVERE WEATHER DID HAPPEN TO OCCUR...
THE MAIN SEVERE WEATHER THREAT WOULD BE LARGE HAIL.
.LONG TERM...SUNDAY THROUGH THURSDAY
346 PM CDT THU MAR 29 2012
FOR SUNDAY...THE MODELS CONTINUE TO STRUGGLE WITH THE LOCATION OF
THE WARM FRONT. SOME OF THE MODELS SUGGEST A FURTHER SOUTHWEST
LOCATION. AS A RESULT...WESTERN WISCONSIN IS NOT AS WARM AS SOME
MODELS INDICATE...THEREFORE...WENT MORE CONSERVATIVE WITH MAXIMUM
TEMPERATURES FOR THIS TIME PERIOD.
FOR THE REMAINDER OF THIS TIME PERIOD...THE MODELS CONTINUE TO
STRUGGLE WITH THE TIMING AND STRENGTH OF SHORT WAVES MOVING THROUGH
THE REGION. THIS MAKES THE TEMPERATURE AND PRECIPITATION FORECAST
RATHER UNCERTAIN. AS A RESULT...STAYED WITH THE ALL BLEND DATA.
&&
.AVIATION...THROUGH 18Z FRIDAY
1242 PM CDT THU MAR 29 2012
MAIN AVIATION FORECAST CONCERNS ARE CLOUDS INCREASING AND CEILINGS
LOWERING INTO THE IFR/MVFR CONDITIONS...AND THE POSSIBILITY OF
THUNDERSTORMS AT BOTH RST AND LSE TAF SITES AFTER 02Z FRIDAY.
LATEST MOSAIC RADAR SHOWING A LINE OF SHOWERS AND THUNDERSTORMS
FROM NORTHWEST MINNESOTA INTO EASTERN SOUTH DAKOTA. LATEST 29.12Z
NAM AND 29.15Z RUC INDICATE LOW PRESSURE OVER THE CENTRAL PLAINS
TO TRACK SOUTH OF THE AREA AND INTO WESTERN ILLINOIS TONIGHT AND
FRIDAY MORNING. BOTH THE NAM/RUC BUFKIT SOUNDINGS SHOW CEILINGS
LOWERING AFTER 02Z FRIDAY AND VISIBILITIES REDUCED...DUE TO ONSET
OF SHOWERS...INTO THE IFR RANGE AT RST AFTER 05Z FRIDAY...WITH
MVFR TO NEAR IFR CONDITIONS EXPECTED AT LSE AFTER 06Z. THE 28.12Z
NAM AND 28.15Z RUC SHOW THE MVFR TO NEAR IFR CONDITIONS TO LINGER
THROUGH 18Z FRIDAY AND ALSO THE POSSIBILITY OF DRIZZLE PER BUFKIT
SOUNDINGS. HAVE CONTINUED THESE CONDITIONS AT BOTH TAF SITES
THROUGH 18Z. THE DETERMINISTIC RUC AND NAM CONTINUE SHOW SOME
INSTABILITY IN ASSOCIATION WITH THE LOW PRESSURE SYSTEM AND HAVE
MENTIONED CB BETWEEN 05-09Z FRIDAY WHEN THE BEST CHANCES OF
THUNDERSTORMS POSSIBLY OCCURRING AT BOTH RST AND LSE TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
346 PM CDT THU MAR 29 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1243 PM CDT THU MAR 29 2012
.SHORT TERM...TODAY
856 AM CDT THU MAR 29 2012
LATEST 14Z METARS INDICATE TEMPERATURES HAVE CLIMBED INTO THE
MIDDLE 30S TO UPPER 40S. THEREFORE...THE FREEZE WARNING AND FROST
ADVISORY HAS BEEN ALLOWED TO EXPIRE AT 9 AM THIS MORNING.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
351 AM CDT THU MAR 29 2012
29.00Z MODELS IN BETTER AGREEMENT SUNDAY WITH THE AREA TO BE UNDER
STRONG RIDGING ALOFT AND IN THE WARM SECTOR OF THE NEXT LOW/TROUGH
MOVING ACROSS THE NORTHERN PLAINS. STRONG SOUTHERLY LOW LEVEL FLOW
OVER THE AREA SUN WITH 925MB TEMPS CLIMBING INTO THE +20 TO +24C
RANGE. RAISED SUNDAY HIGHS TOWARD THE WARMER MID 70S TO LOWER 80S
GUIDANCE VALUES OVER MUCH OF THE FCST AREA. BEYOND SUNDAY...MODELS
DIFFER...WITH LARGE DIFFERENCES...ON THE EVOLUTION OF THE TROUGHING
MOVING INTO/ACROSS THE CENTRAL CONUS. GFS/ECMWF ARE MORE PROGRESSIVE
SOLUTION WHILE UKMET/GEM SLOWER...MORE CLOSED LOW LINGERING IN THE
CENTRAL CONUS EARLY NEXT WEEK. ECMWF DOES SHOW SOME BETTER RUN-TO-
RUN CONSISTENCY IN THE MON-WED PERIOD AS THE TROUGHING MOVES ACROSS
THE UPPER MIDWEST. A BLEND OF IT AND THE ENSEMBLE MEANS PREFERRED.
SHRA/TSRA CHANCES IN THE 30-40 PERCENT RANGE CENTERED ON MON/MON
NIGHT REASONABLE FOR NOW WITH THE EXPECTED SFC-MID LEVEL TROUGH
PASSAGE. AFTER A WARM SUN/MON...TEMPS COOL IN DEEPER NORTHWEST FLOW
BEHIND THE TROUGH/LOW FOR TUE/WED. DAY 4-7 FCST GRIDS USING A
MODEL/ENSEMBLE CONSENSUS LOOK WELL TRENDED AT THIS TIME.
&&
.AVIATION...THROUGH 18Z FRIDAY
1242 PM CDT THU MAR 29 2012
MAIN AVIATION FORECAST CONCERNS ARE CLOUDS INCREASING AND CEILINGS
LOWERING INTO THE IFR/MVFR CONDITIONS...AND THE POSSIBILITY OF
THUNDERSTORMS AT BOTH RST AND LSE TAF SITES AFTER 02Z FRIDAY.
LATEST MOSAIC RADAR SHOWING A LINE OF SHOWERS AND THUNDERSTORMS
FROM NORTHWEST MINNESOTA INTO EASTERN SOUTH DAKOTA. LATEST 29.12Z
NAM AND 29.15Z RUC INDICATE LOW PRESSURE OVER THE CENTRAL PLAINS
TO TRACK SOUTH OF THE AREA AND INTO WESTERN ILLINOIS TONIGHT AND
FRIDAY MORNING. BOTH THE NAM/RUC BUFKIT SOUNDINGS SHOW CEILINGS
LOWERING AFTER 02Z FRIDAY AND VISIBILITIES REDUCED...DUE TO ONSET
OF SHOWERS...INTO THE IFR RANGE AT RST AFTER 05Z FRIDAY...WITH
MVFR TO NEAR IFR CONDITIONS EXPECTED AT LSE AFTER 06Z. THE 28.12Z
NAM AND 28.15Z RUC SHOW THE MVFR TO NEAR IFR CONDITIONS TO LINGER
THROUGH 18Z FRIDAY AND ALSO THE POSSIBILITY OF DRIZZLE PER BUFKIT
SOUNDINGS. HAVE CONTINUED THESE CONDITIONS AT BOTH TAF SITES
THROUGH 18Z. THE DETERMINISTIC RUC AND NAM CONTINUE SHOW SOME
INSTABILITY IN ASSOCIATION WITH THE LOW PRESSURE SYSTEM AND HAVE
MENTIONED CB BETWEEN 05-09Z FRIDAY WHEN THE BEST CHANCES OF
THUNDERSTORMS POSSIBLY OCCURRING AT BOTH RST AND LSE TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
922 AM CDT THU MAR 29 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM....RRS
AVIATION...DTJ