Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 04/18/12
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1248 AM CDT MON APR 16 2012
.AVIATION...
A COLD FRONT CONTINUES TO MOVE THROUGH ARKANSAS AT THIS TIME. THE
LINE OF SHOWERS AND THUNDERSTORMS WILL EXIT SOUTHEAST ARKANSAS BY
10Z. CLEAR SKIES WILL FOLLOW BEHIND THE PRECIPITATION. THE FRONT
WILL STALL JUST SOUTHEAST OF ARKANSAS. A WAVE MOVING ALONG THE
FRONT TOMORROW EVENING SHOULD BRING HIGH CLOUDS TO THE SOUTHEAST
SECTION OF THE STATE. VFR CONDITIONS WILL DOMINATE ONCE THE RAIN
EXITS THE AREA.
&&
.PREV DISCUSSION... /ISSUED 1006 PM CDT SUN APR 15 2012/
UPDATE...
HAVE UPDATED THE MAJORITY OF FORECAST THROUGH THE OVERNIGHT HOURS
AS SEVERE THREAT CONTINUES TO WIND DOWN THIS EVENING. ONLY
MINIMAL WARNINGS WERE NEEDED THIS EVENING AS TORNADIC STORMS WERE
NEVER REALLY ABLE TO GET GOING DUE TO THE LACK OF LOW LEVEL
INSTABILITY WITH ONLY A FEW BOW ECHO STRUCTURES BEING ABLE TO GET
ESTABLISHED.
WHAT THREAT DOES REMAIN FOR THE STATE HAS PUSHED OFF TO THE EAST
AND NORTHEAST AND THE TORNADO WATCH HAS BEEN DISCONTINUED FOR THE
LITTLE ROCK COUNTY WARNING AREA. HOWEVER...SEVERAL MORE HOURS OF
SHOWERS WITH EMBEDDED THUNDER WILL PERSIST BEFORE ENDING FROM WEST
TO EAST OVERNIGHT.
FORECAST UPDATED TO ADJUST PRECIPITATION CHANCES BASED ON RADAR
TRENDS AND TEMPERATURES AS MANY AREAS ALREADY CLOSE TO OVERNIGHT
LOWS. ALL PRODUCTS OUT.
PREV DISCUSSION... /ISSUED 747 PM CDT SUN APR 15 2012/
UPDATE...
HAVE UPDATED 1ST AND 2ND PERIOD GRIDS TO REFLECT RECENT RADAR AND
SFC OBSERVATION TRENDS. MAIN BAND OF SHOWERS AND EMBEDDED
THUNDERSTORMS STRETCHES FROM MENA UP THROUGH CLARKSVILLE AND
HARRISON IN THE WEST...AND EL DORADO TO BATESVILLE IN THE EAST.
RAPID REFRESH RUC AS WELL AS OTHER HIGH RESOLUTION MODELS
CONTINUE TO INDICATE THE BACK EDGE OF THIS LINE WILL CLEAR A
HARRISON-MENA LINE BY ROUGHLY 10 PM...A BATESVILLE-LITTLE ROCK-
CAMDEN LINE AROUND 1 AM...AND FINALLY MONTICELLO SHORTLY BEFORE
DAY BREAK MONDAY MORNING. HAVE ADJUSTED POP GRIDS ACCORDINGLY.
THE THREAT THREAT FOR TORNADOES...DAMAGING WINDS AND LARGE HAIL
SEEMS TO BE QUICKLY DIMINISHING GIVEN RADAR TRENDS AND INSTABILITY
INDICES. HAVE ALREADY TRIMMED BACK SOME WESTERN COUNTIES FROM
TORNADO WATCH 179. WILL CONTINUE TO MONITOR RADAR TRENDS OVER THE
NEXT FEW HOURS...AND FURTHER TRIM COUNTIES WHEN/WHERE POSSIBLE.
OTHERWISE JUST TWEAKED TEMPS AND WINDS FOR THE OVERNIGHT HOURS.
ALL UPDATED PRODUCTS AND GRIDS ARE OUT.
PREV DISCUSSION... /ISSUED 615 PM CDT SUN APR 15 2012/
AVIATION...
THE 00Z TAFS WILL BE OUT SHORTLY.
PRIMARY CONCERNS FOR THIS TAF CYCLE WILL BE THUNDERSTORMS. LEADING
EDGE OF SQUALL LINE WAS LOCATED FROM JUST EAST OF ARKADELPHIA NE
THROUGH CONWAY AND UP THROUGH MOUNTAIN VIEW AS OF 2300Z. EXPECT
THIS LINE TO AFFECT KLIT BY RIGHT AT 00Z...KPBF BY 01-02Z...AND
KLLQ AROUND 02Z. WILL ADVERTISE PREVAILING -SHRA WITH VCTS AND
TEMPO TSRA AND MVFR CONDITIONS THROUGH ROUGHLY 04Z FOR ALL SITES
EXCEPT KHRO. BACK EDGE OF LINE IS APPROACHING KHRO AND SHOULD PUSH
EAST OF THERE BY 02Z- 03Z...EAST OF KLIT BY ROUGHLY 07Z AND
FINALLY EAST OF KLLQ BY 08Z- 09Z. AFTER LINE PUSHES THROUGH...A
QUICK RETURN TO VFR CONDITIONS SHOULD BE SEEN...WITH SKC 4-6HRS
AFTER LINE PUSHES THROUGH.
PREV DISCUSSION... /ISSUED 303 PM CDT SUN APR 15 2012/
SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
STORMS HAVING SOME DIFFICULTY INTENSIFYING IN WESTERN ARKANSAS
EARLY THIS AFTERNOON. INSTABILITY GRADUALLY INCREASING...AND
WOULD EXPECT PRECIPITATION TO CONGEAL INTO MORE OF A LINE AS
IT MOVES INTO CENTRAL/EASTERN SECTIONS OF THE STATE THIS EVENING.
SOME STORMS COULD BE SEVERE...WITH WIND DAMAGE THE MAIN CONCERN.
MAIN STORM SYSTEM WILL MOVE WELL TO THE NORTH ON MONDAY...AND THE
FRONT TRIGGERING THE PRECIPITATION WILL STALL FOR A TIME JUST
SOUTHEAST OF THE STATE. GIVEN THIS...ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS COULD LINGER SOUTHEAST OF LITTLE ROCK. OTHERWISE...
CLEARING WILL OCCUR FARTHER NORTH AND WEST...WITH SLIGHTLY
COOLER/DRIER AIR.
PRECIPITATION CHANCES WILL FINALLY COME TO AN END IN THE
SOUTHEAST MONDAY EVENING AS HIGH PRESSURE BUILDS INTO THE REGION
FROM THE PLAINS. THIS WILL KICK THE FRONT TOWARD THE SOUTHEAST
UNITED STATES.
THE REMAINDER OF THE PERIOD WILL FEATURE TRANQUIL CONDITIONS.
TEMPERATURES TUESDAY AND WEDNESDAY WILL BE MOSTLY ABOVE NORMAL.
LONG TERM...THURSDAY THROUGH SUNDAY
FORECAST WILL START OFF DRY AS NEARLY ZONAL FLOW WILL BE IN PLACE
ACROSS THE CENTRAL CONUS AT THE START OF THE LONG TERM.
HOWEVER...UPPER LEVEL TROUGH WILL EXIT THE ROCKIES BY
FRI...DEEPENING OVER THE PLAINS. THIS WILL PUSH A COLD FRONT SOUTH
ACROSS AR BY FRI EVENING. HAVE PRECIP CHANCES STARTING LATE THU
NIGHT ACROSS THE NW...THEN SPREADING SE DURING THE DAY ON FRI AS THE
FRONT TRAVERSES THE STATE. PRECIP CHANCES THEN DECREASE FROM NW TO
SE BY FRI NIGHT INTO SAT AS HIGH PRESSURE DIVES SE ACROSS THE PLAINS.
DRY CONDITIONS WILL THEN PERSIST THROUGH PRETTY MUCH THE REST OF THE
LONG TERM AS NW UPPER FLOW WILL BE DOMINANT ACROSS THE CENTRAL
CONUS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 72 49 74 49 / 10 10 0 10
CAMDEN AR 80 55 80 51 / 20 10 0 10
HARRISON AR 70 46 73 49 / 10 10 0 10
HOT SPRINGS AR 79 54 78 51 / 10 10 0 10
LITTLE ROCK AR 78 55 77 53 / 10 10 0 10
MONTICELLO AR 80 58 79 54 / 20 10 0 10
MOUNT IDA AR 77 48 77 49 / 10 10 0 10
MOUNTAIN HOME AR 73 46 75 48 / 10 10 0 10
NEWPORT AR 73 49 75 51 / 20 10 0 10
PINE BLUFF AR 78 56 78 53 / 20 10 0 10
RUSSELLVILLE AR 75 48 78 50 / 10 10 0 10
SEARCY AR 76 46 75 51 / 10 10 0 10
STUTTGART AR 77 53 76 54 / 20 10 0 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...51
AREA FORECAST DISCUSSION
NWS DENVER CO
836 PM MDT TUE APR 17 2012
.UPDATE...
&&
.AVIATION...SOME VIRGA MOVED ACROSS EARLY THIS EVENING AND CAUSED
A BRIEF INCREASE IN WNW WINDS. CURRENTLY A WK BNDRY IS MOVING SW
TOWARDS DIA WHICH MAY CAUSE THE WINDS TO GO LIGHT NELY FOR AN HOUR
OR SO BEFORE GRADUALLY BECOMING DRAINAGE BY 06Z.
&&
.PREV DISCUSSION... /ISSUED 302 PM MDT TUE APR 17 2012/
SHORT TERM...WEAK SHORTWAVE FINALLY SLIDING ACROSS WYOMING WITH
TAIL END MOVING OVER NORTHWEST COLORADO. RADAR SHOWING SOME
PRECIPITATION DEVELOPING OVER THE NORTHERN MOUNTAINS THOUGH WEB
CAMS SHOWING MOST OF THIS ACTIVITY ALONG CONTINENTAL DIVIDE IN
GRAND COUNTY. SHOULD BEGIN TO SEE THE PRECIP BECOMING A BIT MORE
WIDESPREAD AS MID LEVEL QG ASCENT INCREASES. MODELS SHOW BEST LIFT
TO STAY WELL NORTH OF COLORADO AS WAVE MOVES ACROSS REGION. RUC
AND NAM CROSS SECTIONS SHOW SOME INCREASE IN MOISTURE...MAINLY
ABOVE MOUNTAIN TOP. LATEST RUC AND HRRR AS WELL AS THE 18Z NAM
RUN DO NOT GENERATE MUCH IN THE WAY OF QPF THROUGH THE EVENING.
WILL MAINTAIN THE SCATTERED POPS FOR MOST OF MOUNTAIN AREAS NORTH
OF INTERSTATE 70 THROUGH EARLY EVENING...WITH DECREASING POPS
REST OF THE EVENING. AS FOR THUNDER CHANCES...FORECAST CAPES STILL
LOOKING LOW...MAYBE 300 J/KG FOR A SHORT TIME OVER THE NORTHERN
MOUNTAINS. SO FAR...NO LIGHTNING NOTED UPSTREAM. WILL NOT INCLUDE
FOR EVENING FORECASTS. TEMPERATURES TO BE COLD ENOUGH FOR SNOW
ACROSS THE MOUNTAINS WITH MAINLY RAIN VALLEY AREAS. ACROSS
PLAINS...STILL A SLIGHT CHANCE FOR A FEW HIGH BASED SHOWERS ALONG
THE WYOMING BORDER EARLY THIS EVENING WITH REST OF THE PLAINS DRY.
WINDS TO INCREASE FOR A SHORT TIME BEHIND THE EXITING WAVE BEFORE
DECREASING DURING THE EVENING. GRADUAL CLEARING EXPECTED OVERNIGHT
WHICH SHOULD KEEP TEMPERATURES FAIRLY MILD. ON WEDNESDAY...NEXT
TROUGH APPROACHES FROM THE NORTHWEST AS MODERATE WESTERLY FLOW
ALOFT CONTINUES OVER COLORADO. MODEL CROSS SECTIONS SHOW SOME
INCREASE IN MOISTURE ACROSS MOUNTAINS DURING THE AFTERNOON ALONG
WITH SOME WEAK QG ASCENT. BEST AREA FOR ANY PRECIPITATION LOOKS TO
BE THE NORTHERN MOUNTAINS SO WILL WILL INCREASE THE POPS THERE TO
THE CHANCE CATEGORY FOR THE AFTERNOON. THICKNESS PROGS SUGGEST
A SLIGHT CHANCE OF SNOW. FORECAST CAPES REMAIN LOW SO WILL NOT
MENTION THUNDER. AS FOR PLAINS...SOME SHOWERS POSSIBLE FOR AREAS
NEAR THE WYOMING BORDER IN AREA OF BETTER ASCENT. MODELS GENERATE
SOME CAPE ALONG THE BORDER...STILL LOOK A BIT LOW TO MENTION
THUNDER AT THIS TIME. THE SHOWERS THAT DO DEVELOP SHOULD BE HIGH
BASED AND CAPABLE OF PRODUCING BRIEF GUSTY WINDS. WILL LEAVE REST
OF PLAINS DRY. SOUTHERLY WINDS TO INCREASE AHEAD OF TROUGH...
THOUGH MODELS SHOW WINDS MORE WESTERLY ACROSS PLAINS WITH PASSAGE
OF WEAK FRONT. THIS MAY BE A BIT FAST GIVEN TO SLOW MOVEMENT OF
UPPER TROUGH. TEMPERATURE AND THICKNESS PROGS AS WELL AS GUIDANCE
SHOW HIGHS IN THE LOWER AND MIDDLE 70S ACROSS PLAINS. CURRENT
TEMPERATURE GRIDS IN LINE WITH GUIDANCE...LOOKS REASONABLE.
LONG TERM...THE NEXT UPPER LEVEL TROF WILL MOVE ACROSS COLORADO
ON LATE WEDNESDAY AND THURSDAY AND GRADUALLY DEEPEN AS IT MOVES
INTO THE CENTRAL PLAINS. THE MODELS ARE VARIED ON MOISTURE
AVAILABILITY WITH THE GFS THE WETTER OF THE MODELS AND MORE
UPSLOPE WHILE THE NAM LOOKS LIKE DRIER WITH THE MOST DOWNSLOPE
FLOW. GIVEN THE VARIABILITY WILL LEAVE THE POPS MAINLY IN THE
SLIGHT CHANCE OVER LOWER ELEVATIONS BUT A SLIGHT BUMP UPWARDS. THE
MOUNTAINS WILL PROBABLY HAVE A BRIEF PERIOD OF RAIN/SNOW SHOWERS
ON THURSDAY AND THROUGH THE NIGHT WITH LIGHT NW OROGRAPHIC FLOW.
THE QG FIELDS ARE ONLY SHOWING WEAK ASCENT SO AT THIS POINT NOT
ALL THAT EXCITED ABOUT THIS NEXT DISTURBANCE.
HIGH PRESSURE RIDGE ALOFT WILL BUILD OVER THE ENTIRE REGION FROM
FRIDAY THROUGH EARLY NEXT WEEK WITH DRYING AND WARMING TREND
THROUGH THE PERIOD. MODELS ARE SHOWING A BIT OF MOISTURE
DEVELOPING UNDER THE RIDGE BY EARLY NEXT WEEK BUT NOT WORTH ADDING
ANY POPS AT THIS TIME.
AVIATION...TROUGH STILL WEST OF THE DENVER AREA...WITH VARIABLE
WINDS AT AREA AIRPORTS. THROUGH EXPECTED TO MOVE ACROSS THE AREA
EARLY EVENING. SHOULD SEE WINDS SHIFT TO THE NORTHWEST BY 23Z WITH
SPEEDS AROUND 15 KTS. SOME INCREASE IN MID LEVEL CLOUDS BUT NOW
DOES NOT APPEAR THAT ILS CEILINGS WILL DEVELOP. WILL MAINTAIN THE
LATEST UPDATE TRENDS FOR THE 00Z ISSUANCE. ANY SHOWERS THAT
DEVELOP WILL STAY NORTH AND WEST OF DENVER AIRPORTS. WINDS TO
DECREASE AND BECOME SOUTHERLY DURING THE EVENING AS DRAINAGE FLOW
DEVELOPS. THE SOUTHERLY WINDS TO CONTINUE THROUGH THE DAY...MAY
BECOME A BIT MORE SOUTHEAST DURING THE AFTERNOON. SOME HIGH BASED
SHOWERS POSSIBLE NORTH OF THE AREA AFTER 18Z...NOT EXPECTED TO
AFFECT THE AREA AIRPORTS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....ENTREKIN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1121 AM MDT MON APR 16 2012
.UPDATE...WEAK BOUNDARY NOTED ACROSS LINCOLN AND EASTERN
WASHINGTON COUNTIES AS SHORTWAVE EXITS REGION. ECHOES CURRENTLY
DEVELOPING ALONG THE BOUNDARY WITH CAPES CURRENTLY AROUND 400
J/KG. SO SOME POTENTIAL FOR THUNDER IN THIS REGION. DRIER AIR
BEGINNING TO SPREAD ACROSS WESTERN PORTIONS OF THE CFWA AS NOTED
BY A DECREASE IN SHOWER ACTIVITY. MOUNTAIN WEB CAM HAVE ALSO SHOWN
A MARKED DECREASE. MODELS CONTINUE TO DRY OUT THE
REGION...ALTHOUGH HRRR AND RUC INDICATE SOME WEAK SHOWERS THROUGH
THE AFTERNOON ACROSS THE FAR NORTHEAST PLAINS WITH MINIMAL CAPES.
WILL BE LOWERING SHOWER CHANCES FOR THIS AFTERNOON...WITH A SLIGHT
CHANCE FOR THUNDER THROUGH 21Z. WILL ALSO DROP THE MENTION OF
SNOW. DRY CONDITIONS LOOK GOOD FOR THIS EVENING.
&&
.AVIATION...WINDS SHOULD REMAIN NORTHWESTERLY THROUGH THE
AFTERNOON AS THERE IS NO HINT OF ANY CYCLONE DEVELOPING. ANY
SHOWER ACTIVITY SHOULD STAY WELL EAST OF THE AREA AIRPORTS. WILL
MAINTAIN CURRENT TAF TRENDS FOR THE NEXT ISSUANCE.
&&
.PREV DISCUSSION... /ISSUED 435 AM MDT SUN APR 15 2012/
SHORT TERM...BATCH OF SHOWERS FROM WELD COUNTY INTO THE CENTRAL
MOUNTAINS WILL CONTINUE TO MOVE EAST THIS MORNING. IT LOOKS LIKE
THE MAIN AREA HAS MISSED DENVER...BUT I WILL ADJUST POPS A LITTLE
BIT IN ACCORDANCE WITH THE PATH OF THIS SHOWER BAND. WARMING AND
DRYING TODAY...BUT WITH COOL TEMPERATURES ALOFT WE SHOULD HAVE MORE
CONVECTION DEVELOP THIS AFTERNOON. WITH THE DRYING...CAPES WILL BE
LOWER...GENERALLY AROUND 500 J/KG...SO NOT EXPECTING HAIL BUT I WILL
ADD BACK SOME THUNDER OUT ON THE PLAINS. STILL THINK THE CHANCE OF
MEASURABLE RAIN IN DENVER IS TOO LOW TO MENTION. WITH CLEARING
SKIES TONIGHT AND DRIER AIR IT WILL BE A COOL NIGHT...LOWERED THE
LOW TEMPERATURES 3 DEGREES TO MATCH GUIDANCE TEMPS.
LONG TERM...MODELS HAVE WEST-NORTHWESTERLY FLOW ALOFT FOR THE CWA
TUESDAY INTO TUESDAY NIGHT. ZONAL FLOW TAKES OVER EARLY WEDNESDAY
MORNING INTO WEDNESDAY EVENING...THEN A WEAK UPPER TROUGH IS PROGGED
TO MOVE ACROSS THE CWA BY EARLY THURSDAY. THE SYNOPTIC SCALE ENERGY
IS NONDESCRIPT TUESDAY AND TUESDAY NIGHT. WEAK UPWARD QG VERTICAL
VELOCITY IS PROGGED FOR THE FORECAST AREA WEDNESDAY AND WEDNESDAY
EVENING. WEAK DOWNSLOPING TO NORMAL DIURNAL WIND PATTERNS ARE
PROGGED IN THE LOW LEVELS TUESDAY. NORMAL PATTERNS SHOULD PREVAIL
TUESDAY NIGHT INTO WEDNESDAY...WITH SOUTHEASTERLIES WEDNESDAY
AFTERNOON...THEN NORTH-NORTHWESTERLIES WEDNESDAY NIGHT. FOR
MOISTURE...MODELS HAVE QUITE A BIT TUESDAY THROUGH WEDNESDAY NIGHT
..BUT IT IS MOSTLY IN THE MID AND UPPER LEVELS. WEDNESDAY NIGHT
..MOISTURE IS FAIRLY DEEP OVER THE MOUNTAINS. BOUNDARY LAYER DEW
POINT FIELDS SHOW TEENS TO MID 20S F READINGS TUESDAY. THEY COME UP
A BIT TUESDAY NIGHT AND WEDNESDAY...WITH THEM GETTING INTO 30S TO
LOWER 40S F BY WEDNESDAY EVENING. THERE IS A BIT OF CAPE AROUND
LATER WEDNESDAY AFTERNOON...AND LAPSE RATES ARE PRETTY STEEP BELOW
400 MB. THE QPF FIELDS SHOW A TAD OF MEASURABLE PRECIPITATION
TUESDAY AFTERNOON/EVENING MAINLY OVER THE MOUNTAINS. THEY SHOW
SMALL AMOUNTS WEDNESDAY AFTERNOON AND NIGHT...MAINLY OVER THE
MOUNTAINS AND EASTERN HALF OF THE PLAINS. FOR POPS...WILL GO
"SLIGHT CHANCE" IN THE HIGH MOUNTAINS TUESDAY AFTERNOON. FOR
WEDNESDAY AFTERNOON AND NIGHT...WILL GO 20-40%S IN THE MOUNTAINS AND
10-20%S OUT ON THE PLAINS. FOR TEMPERATURES...TUESDAY`S HIGHS ARE
PROGGED TO WARM-UP 3-7 C FROM TODAY`S. WEDNESDAY`S HIGHS ARE 1-2 C
WARMER THAN TUESDAY`S. FOR THE LATER DAYS...THURSDAY THROUGH SUNDAY
..THERE IS NORTHWESTERLY FLOW ALOFT PROGGED ON THURSDAY...THEN A
STRONG NORTHERLY JET MAXIMUM IS PROGGED TO MOVE OVER THE CWA LATER
THURSDAY NIGHT INTO MIDDAY FRIDAY. AFTER THAT...THE FLOW ALOFT
DECREASES AND IS NORTHWESTERLY AS AN UPPER RIDGE TO THE WEST MOVES
SLOWLY THIS WAY. THERE IS SOME MOISTURE AROUND THURSDAY AND
FRIDAY...SATURDAY AND SUNDAY ARE DRY. TEMPERATURES WILL BE NEAR
SEASONAL NORMALS THURSDAY AND FRIDAY...THEN WARM-UP SATURDAY AND
SUNDAY.
AVIATION...VFR CONDITIONS ARE EXPECTED THROUGH TONIGHT. THERE WILL
BE ISOLATED SHOWERS DURING THE EARLY MORNING...WITH A CHANCE OF
NEEDING INSTRUMENT APPROACHES TO KDEN UNTIL ABOUT 15Z. ISOLATED
SHOWERS MAY REDEVELOP THIS AFTERNOON...BUT CEILINGS WILL BE HIGHER.
WINDS WILL HAVE SOME VARIABILITY EARLY THIS MORNING DUE TO THE
SHOWERS...THEN SHIFT TO THE NORTH TO NORTHWEST BY LATE MORNING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RJK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1144 PM CDT SUN APR 15 2012
.AVIATION...
WINDY CONDITIONS EXPECTED THROUGH 17/00Z. SOUTHWEST WINDS 20 TO
30 KTS...GUSTING 35 KTS WILL SHIFT TO THE WEST AND NORTHWEST BY
12Z. BKN-OVC LOW CLOUDS RESULTING IN MOSTLY MVFR CONDITIONS TO
ARRIVE BY 12Z WITH CLEARING SKIES BY 21Z. VFR CONDITIONS WITH
WINDS DECREASING TO AROUND 10 KTS TOWARD SUNSET. NICHOLS
&&
.PREV DISCUSSION... /ISSUED 337 PM CDT SUN APR 15 2012/
SYNOPSIS...
12Z UA ANALYSIS HAS A NEGATIVELY TILTED EXTRATROPICAL CYCLONE
OVER THE PLAINS. 850 AND 700MB WARM AND COLD FRONTS RAN FROM THE
UPPER LOW OVER NEBRASKA INTO SOUTH DAKOTA AND MINNESOTA. THE COLD
FRONTS DROPPED SOUTH FROM THE LOW INTO THE SOUTHERN PLAINS. A LLJ
OF 50-70 KNOTS RAIN FROM THE GULF COAST INTO THE GREAT LAKES
HELPING TO TRANSPORT MOISTURE NORTH FROM THE GULF.
18Z SFC ANALYSIS HAS A LOW NEAR KODX WITH A SECONDARY LOW NEAR KYKN.
THE WARM FRONT RAN NORTHEAST INTO SOUTHERN MINNESOTA AND THEN EAST
INTO CENTRAL WISCONSIN. THE COLD FRONT RAN FROM THE KYKN LOW SOUTH
THROUGH THE EASTERN PARTS OF KANSAS...OKLAHOMA...AND TEXAS. A SUBTLE
TROF RAN FROM THE KYKN LOW INTO NORTHEAST MISSOURI. A NARROW BAND OF
60 DEWPOINTS FROM WISCONSIN SOUTH THROUGH ILLINOIS AND THE LOWER
MISSISSIPPI VALLEY. OUTSIDE OF THIS BAND DEW POINTS WERE IN THE 50S.
DEW POINTS IN THE 30S AND 40S WERE ACROSS THE PLAINS.
SHORT TERM...TONIGHT AND MONDAY
BASED ON CURRENT RUC TRENDS THE BETTER RAIN CHANCES WILL BE ACROSS
THE EASTERN CWFA THIS EVENING. THE WINDOW OF OPPORTUNITY FOR ANY
SEVERE STORMS IS STARTING TO CLOSE. THE SUBSTANTIAL CAP ON THE 18Z
SOUNDING IS THE LIMITING FACTOR. IF THE CAP DOES NOT BREAK BY SUNSET
THEN THE CHANCES FOR ANY SEVERE STORMS WILL RAPIDLY DECREASE.
MOST OF THE PRECIPITATION THIS EVENING WILL BE DONE BY 10 PM EXCEPT
FOR THE FAR EASTERN PARTS OF THE CWFA. WHATEVER CONVECTION IS STILL
PRESENT IN THE CWFA AT 03Z WILL EXIT THE CWFA BY MIDNIGHT. AFTER
MIDNIGHT QUIET ALBEIT WINDY CONDITIONS WILL BE SEEN ACROSS THE AREA.
WRAP AROUND CLOUDS WILL MOVE ACROSS THE CWFA MONDAY MORNING WITH
SOME SHOWERS OVER ROUGHLY THE NORTHERN HALF OF THE CWFA. SKIES WILL
SLOWLY CLEAR DURING THE AFTERNOON HOURS. THE COMBINATION OF CLOUDS
AND PRECIPITATION DURING THE MORNING HOURS WILL HOLD TEMPERATURES TO
BELOW NORMAL.
LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY
THE MODELS HAVE A WEAK DISTURBANCE THAT MOVES THROUGH THE AREA LATE
MONDAY NIGHT/TUESDAY MORNING. SOME MODELS INITIATE PRECIP WITH THIS
FEATURE WHILE OTHERS DO NOT. FOR NOW HAVE OPTED TO KEEP THE SCHC
POPS BUT MOISTURE AVAILABILITY FOR ANYTHING TO DEVELOP IS
QUESTIONABLE. THE FACT THERE IS A WEAK DISTURBANCE MOVING THROUGH
THE AREA INDICATES MORE CLOUDS WILL BE PRESENT WHICH WILL HAVE AN
AFFECT ON TEMPERATURES. HIGH PRESSURE OVER THE AREA WILL RESULT IN
LIGHT WINDS WHICH WILL ALLOW TEMPERATURES TO COOL. FREEZING
TEMPERATURES ARE QUESTIONABLE BUT SOME PATCHY FROST MIGHT OCCUR IN
AND IMMEDIATELY SOUTH OF THE HWY 20 CORRIDOR.
AFTER A QUIET TUESDAY AFTERNOON/EVENING THE NEXT SYSTEM APPROACHES
THE AREA FROM THE PLAINS. MODELS SHOW THIS SYSTEM TO BE MORE
VIGOROUS SO THE CHANCES FOR PRECIPITATION SHOULD BE BETTER. THUS THE
SCHC/CHC POPS AFTER MIDNIGHT LOOK REASONABLE GIVEN THE TIMING.
ON WEDNESDAY THIS SYSTEM WILL MOVE ACROSS THE AREA BRINGING ANOTHER
CHANCE OF RAIN. POPS HAVE BEEN INCREASED TO HIGH CHC OVER MOST OF
THE AREA BUT MAY NEED TO BE INCREASED FURTHER TO LIKELY IF CURRENT
TRENDS WITH THE MODELS CONTINUE.
WEDNESDAY NIGHT ON...
MODEL CONSENSUS MAINTAINS AN ACTIVE NORTHWEST FLOW WITH SEVERAL
DISTURBANCES MOVING THROUGH IT. THE INITIAL WAVE ON WEDNESDAY EXITS
THE AREA WED EVENING SO THE SCHC/CHC POPS LOOK REASONABLE. MODELS
CONTINUE TO DISAGREE ON POSITION AND TIMING BUT ANOTHER STORM SYSTEM
WILL MOVE THROUGH THE AREA IN THE THURSDAY THROUGH FRIDAY EVENING
TIME PERIOD. CONSENSUS GIVES MAINLY CHC POPS WITH THE HIGHEST POPS
CENTERED ON THURSDAY NIGHT.
CONSENSUS HAS A WEAK DISTURBANCE MOVING THROUGH THE AREA ON
SATURDAY. MOISTURE IS QUESTIONABLE RIGHT NOW SO THE SCHC POPS BY THE
CONSENSUS LOOKS REASONABLE. RIGHT NOW SUNDAY LOOKS DRY WITH HIGH
PRESSURE MOVING THROUGH THE AREA. 08
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
552 PM CDT MON APR 16 2012
...UPDATED FOR THE 00Z TAF ISSUANCE...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 212 PM CDT MON APR 16 2012
SYNOPSIS:
THE 16 APRIL 2012 12Z SYNOPTIC MAPS SHOWED A STRONG 125 KT TO 135 KT
300 HPA JET ACROSS MISSOURI. ANOTHER 300 HPA JET STREAK WAS LOCATED
ACROSS QUEBEC. FURTHER UPSTREAM, A 50 KT TO 70 KT 300 HPA JET WAS LOCATED
ACROSS THE PACIFIC NORTHWEST. AT 500 HPA, A MINOR SHORTWAVE TROUGH WAS
MOVING ACROSS THE ROCKIES. MOISTURE ADVECTION DOWNSTREAM OF A 536 DM
LOW WAS OBSERVED ACROSS THE UPPER GREAT LAKES AND INTO THE OHIO RIVER
VALLEY. IN ADDITION, SOME MID LEVEL MOISTURE WAS PUSHING ONSHORE ACROSS
OREGON/WASHINGTON. AT 700 HPA, A RELATIVELY COOL AND DRY AIRMASS HAS
SPREAD OVER THE PLAINS IN THE WAKE OF A DEPARTING SYSTEM. AT 850 HPA,
SOME WRAP AROUND MOISTURE WAS OBSERVED ACROSS MINNESOTA AND STRETCHING
DOWN TO EASTERN KANSAS IN ASSOCIATION WITH A LOW TO MID LEVEL CYCLONE
TO THE NORTHEAST. AT THE SFC, A COLD FRONT WAS ANALYZED FROM SE ONTARIO
TO TEXAS. ANY GULF OF MEXICO MOISTURE WAS SOUTH OF THIS BOUNDARY.
TONIGHT:
VISIBLE SATELLITE AND WSR-88D TRENDS HAVE BEEN ECHOING MODEL OUTPUT,
PARTICULARLY FROM THE HRRR. AS A RESULT, HAVE RELIED HEAVILY ON THIS
MODEL FOR TONIGHT. AN UPPER LEVEL SHORTWAVE TROUGH/400 HPA PV ANOMALY
WILL MOVE ACROSS SOUTHWEST KANSAS THIS EVENING. CONVECTION HAS FORMED
ACROSS SOUTHEAST COLORADO AS A RESULT. EVEN THOUGH DEWPOINTS ARE RUNNING
ONLY IN THE 30S DEG F RANGE, THE HRRR SHOWS SOME WEAK INSTABILITY FORMING.
THIS IS ECHOED IN FORECAST SOUNDINGS ACROSS MY COUNTY WARNING AREA.
100-300 J/KG OF CAPE ALONG WITH FAIRLY STEEP 700 HPA TO 500 HPA WILL
LEAD TO EASTWARD PROPAGATING SHOWERS AND ISOLATED THUNDERSTORMS THROUGH
THE REST OF THIS AFTERNOON AND INTO THE EARLY EVENING. SEVERE WEATHER
IS NOT EXPECTED DUE TO WEAK INSTABILITY/SHEAR. OVERNIGHT LOWS WILL BE SLIGHTLY
WARMER WITH MID 30S DEG F OUT WEST AND MID 40S DEG F ACROSS SOUTH CENTRAL
KANSAS. THE 12Z NAM WAS SHOWING INCREASING 1000-850 HPA MOISTURE, BUT
THINK THIS IS AN OUTLIER COMPARED TO THE REST OF THE MODELS. THE MAIN
IMPLICATIONS FROM THIS WOULD BE AREAS OF STRATUS AND SLIGHTLY WARMER
MINIMUMS UNDER THE CLOUD DECK. WILL HOLD OFF FOR NOW ON THIS SOLUTION.
TOMORROW:
FLAT 500 HPA RIDGING IS EXPECTED ACROSS THE ROCKIES AND HIGH PLAINS
TOMORROW. THIS WILL LEAD TO WESTERLY FLOW ALOFT AND DOWNSLOPE SOUTHWESTERLY
SURFACE TO 600 HPA WINDS. THE ATMOSPHERE BECOMES DEEPLY MIXED TO ABOUT
650 HPA WHICH SUPPORTS WARMER MAXIMUM TEMPERATURES FOR TOMORROW VIA
ADIABATIC COMPRESSIONAL WARMING. THE WIND PROFILE WITHIN THIS LAYER
IS NOT PARTICULARLY STRONG, BUT I DO THINK BREEZY CONDITIONS ARE EXPECTED
AS MIXING AND RESULTANT MOMENTUM TRANSFER DEVELOPS/CONTINUES TOMORROW.
HIGHS WILL BE IN THE 70S DEG F RANGE. NO PRECIPITATION IS EXPECTED AS
SUBSIDENCE IN THE WAKE OF THE TROUGH PREVAILS. A LEE SURFACE TROUGH
ACROSS EASTERN COLORADO WILL CONTINUE AS WELL WITH THE AFOREMENTIONED
PERPENDICULAR FLOW TO THE ROCKIES.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 219 PM CDT MON APR 16 2012
WESTERLY DOWNSLOPE FLOW BEGINS TO IMPROVE TOWARDS MID WEEK AS AN
UPPER LEVEL TROUGH EMBEDDED IN THIS FLOW MOVES QUICKLY EASTWARD
TOWARDS THE NORTHERN PLAINS. THIS UPPER LEVEL TROUGH WILL CROSS OUT
INTO THE PLAINS LATE TUESDAY AND AS IT DOES A SURFACE BOUNDARY WILL
MOVE EAST INTO WESTERN KANSAS. JET UPPER LEVEL DYNAMICS APPEAR
LACKING ACROSS WESTERN KANSAS LATE TUESDAY, HOWEVER THERE WILL BE
SOME FORCING DEVELOPING LATE DAY NEAR THIS BOUNDARY THAT WILL BE
LOCATED NEAR WAKEENEY AND DODGE CITY. AT THIS TIME PRECIPITATION
CHANCES TUESDAY NIGHT STILL APPEARS VERY LOW BASED ON THE WEAK
FORCING ALOFT AND WARMING TEMPERATURES IN THE 850-700MB LAYER WHICH
SHOULD SERVE AS A CAP. AS A RESULT WILL CONTINUE TO FAVOR A DRY
FORECAST TUESDAY NIGHT BUT GIVEN THE RETURN OF NEAR 50 DEGREE
SURFACE DEWPOINTS RETURNING ACROSS SOUTH CENTRAL KANSAS WILL
CONTINUE TO FAVOR THE WARMER PREVIOUS FORECAST FOR LOWS WHICH THE
MET NOW APPEARS TO HINTING AT.
THE NEXT IN A SERIES OF UPPER LEVEL DISTURBANCES WILL THEN CROSS OUT
INTO THE PLAINS ON LATE WEDNESDAY AS WARM AIR ADVECTION IMPROVES
NORTH OF A SURFACE BOUNDARY THAT WILL EXTEND FROM WEST TO EAST
ACROSS NORTHERN KANSAS. THIS CONVECTION SHOULD STAY NORTH OF THE I70
CORRIDOR. BASED ON THE NEW 850MB TEMPERATURE TRENDS FROM THE NAM AND
GFS WILL GO AHEAD AN WARM TEMPERATURES UP INTO THE 80 TO 85 DEGREE
RANGE FOR MUCH OF SOUTHWEST KANSAS.
BY LATE WEEK AN UPPER LEVEL RIDGE IS EXPECTED TO DEVELOP ACROSS THE
WESTERN UNITED STATES AS AN UPPER LOW NEAR THE GULF OF ALASKA BEGINS
TO DROP SOUTH/SOUTHEAST. THE NEXT UPPER LEVEL TROUGH WILL MOVE OUT
INTO THE PLAINS ON THURSDAY WHICH WILL ALLOW THE FRONT ACROSS
NORTHERN KANSAS TO CROSS INTO NORTHERN OKLAHOMA BY THURSDAY EVENING.
MOIST UPSLOPE FLOW DEVELOPING NORTH OF THIS FRONT COMBINED WITH THE
LEFT EXIT REGION OF AN UPPER LEVEL JET ROTATING AROUND THIS
DEVELOPING UPPER RIDGE WILL ENHANCE THUNDERSTORM CHANCES ACROSS MUCH
OF WESTERN KANSAS THURSDAY NIGHT. THESE PRECIPITATION CHANCES WILL
END FROM WEST TO EAST EARLY FRIDAY AS THE UPPER RIDGE LOCATED OVER
THE WEST COAST STARTS TO SHIFT EASTWARD TOWARDS THE ROCKIES. AS FOR
TEMPERATURES LATE WEEK AND OVER THE WEEKEND PERIOD...AFTER A COOL
DOWN BEHIND THE FRONT THURSDAY NIGHT AND FRIDAY A WARMING TREND WILL
BEGIN FOR THE WEEKEND PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 546 PM CDT MON APR 16 2012
A SMALL BAND OF SHOWERS WILL MOVE ACROSS THE TAF SITES EARLY THIS
EVENING. AS THE SHOWERS TRANSVERSE EAST, CIGS MAY LOWER TO THE
OVC050-060CB CATEGORY. WINDS WILL BE LIGHT SOUTHEAST THIS
EVENING, BECOME SOUTH AND LIGHT UNDER 06KTS AFTER SUNDOWN. SKIES
WILL BECOME CLEAR BY MIDNIGHT AS WELL. EXPECT SOUTHWEST WINDS BY
10AM TUESDAY MORNING IN THE BREEZY 15G25KT RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 44 77 48 80 / 80 0 10 0
GCK 41 75 45 80 / 70 0 0 0
EHA 38 77 46 82 / 20 0 0 0
LBL 41 78 47 83 / 80 0 10 0
HYS 42 74 48 77 / 50 0 10 0
P28 46 74 52 80 / 50 0 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...BURGERT
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
224 PM CDT MON APR 16 2012
...UPDATED LONG TERM DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 212 PM CDT MON APR 16 2012
SYNOPSIS:
THE 16 APRIL 2012 12Z SYNOPTIC MAPS SHOWED A STRONG 125 KT TO 135 KT
300 HPA JET ACROSS MISSOURI. ANOTHER 300 HPA JET STREAK WAS LOCATED
ACROSS QUEBEC. FURTHER UPSTREAM, A 50 KT TO 70 KT 300 HPA JET WAS LOCATED
ACROSS THE PACIFIC NORTHWEST. AT 500 HPA, A MINOR SHORTWAVE TROUGH WAS
MOVING ACROSS THE ROCKIES. MOISTURE ADVECTION DOWNSTREAM OF A 536 DM
LOW WAS OBSERVED ACROSS THE UPPER GREAT LAKES AND INTO THE OHIO RIVER
VALLEY. IN ADDITION, SOME MID LEVEL MOISTURE WAS PUSHING ONSHORE ACROSS
OREGON/WASHINGTON. AT 700 HPA, A RELATIVELY COOL AND DRY AIRMASS HAS
SPREAD OVER THE PLAINS IN THE WAKE OF A DEPARTING SYSTEM. AT 850 HPA,
SOME WRAP AROUND MOISTURE WAS OBSERVED ACROSS MINNESOTA AND STRETCHING
DOWN TO EASTERN KANSAS IN ASSOCIATION WITH A LOW TO MID LEVEL CYCLONE
TO THE NORTHEAST. AT THE SFC, A COLD FRONT WAS ANALYZED FROM SE ONTARIO
TO TEXAS. ANY GULF OF MEXICO MOISTURE WAS SOUTH OF THIS BOUNDARY.
TONIGHT:
VISIBLE SATELLITE AND WSR-88D TRENDS HAVE BEEN ECHOING MODEL OUTPUT,
PARTICULARLY FROM THE HRRR. AS A RESULT, HAVE RELIED HEAVILY ON THIS
MODEL FOR TONIGHT. AN UPPER LEVEL SHORTWAVE TROUGH/400 HPA PV ANOMALY
WILL MOVE ACROSS SOUTHWEST KANSAS THIS EVENING. CONVECTION HAS FORMED
ACROSS SOUTHEAST COLORADO AS A RESULT. EVEN THOUGH DEWPOINTS ARE RUNNING
ONLY IN THE 30S DEG F RANGE, THE HRRR SHOWS SOME WEAK INSTABILITY FORMING.
THIS IS ECHOED IN FORECAST SOUNDINGS ACROSS MY COUNTY WARNING AREA.
100-300 J/KG OF CAPE ALONG WITH FAIRLY STEEP 700 HPA TO 500 HPA WILL
LEAD TO EASTWARD PROPAGATING SHOWERS AND ISOLATED THUNDERSTORMS THROUGH
THE REST OF THIS AFTERNOON AND INTO THE EARLY EVENING. SEVERE WEATHER
IS NOT EXPECTED DUE TO WEAK INSTABILITY/SHEAR. OVERNIGHT LOWS WILL BE SLIGHTLY
WARMER WITH MID 30S DEG F OUT WEST AND MID 40S DEG F ACROSS SOUTH CENTRAL
KANSAS. THE 12Z NAM WAS SHOWING INCREASING 1000-850 HPA MOISTURE, BUT
THINK THIS IS AN OUTLIER COMPARED TO THE REST OF THE MODELS. THE MAIN
IMPLICATIONS FROM THIS WOULD BE AREAS OF STRATUS AND SLIGHTLY WARMER
MINIMUMS UNDER THE CLOUD DECK. WILL HOLD OFF FOR NOW ON THIS SOLUTION.
TOMORROW:
FLAT 500 HPA RIDGING IS EXPECTED ACROSS THE ROCKIES AND HIGH PLAINS
TOMORROW. THIS WILL LEAD TO WESTERLY FLOW ALOFT AND DOWNSLOPE SOUTHWESTERLY
SURFACE TO 600 HPA WINDS. THE ATMOSPHERE BECOMES DEEPLY MIXED TO ABOUT
650 HPA WHICH SUPPORTS WARMER MAXIMUM TEMPERATURES FOR TOMORROW VIA
ADIABATIC COMPRESSIONAL WARMING. THE WIND PROFILE WITHIN THIS LAYER
IS NOT PARTICULARLY STRONG, BUT I DO THINK BREEZY CONDITIONS ARE EXPECTED
AS MIXING AND RESULTANT MOMENTUM TRANSFER DEVELOPS/CONTINUES TOMORROW.
HIGHS WILL BE IN THE 70S DEG F RANGE. NO PRECIPITATION IS EXPECTED AS
SUBSIDENCE IN THE WAKE OF THE TROUGH PREVAILS. A LEE SURFACE TROUGH
ACROSS EASTERN COLORADO WILL CONTINUE AS WELL WITH THE AFOREMENTIONED
PERPENDICULAR FLOW TO THE ROCKIES.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 219 PM CDT MON APR 16 2012
WESTERLY DOWNSLOPE FLOW BEGINS TO IMPROVE TOWARDS MID WEEK AS AN
UPPER LEVEL TROUGH EMBEDDED IN THIS FLOW MOVES QUICKLY EASTWARD
TOWARDS THE NORTHERN PLAINS. THIS UPPER LEVEL TROUGH WILL CROSS OUT
INTO THE PLAINS LATE TUESDAY AND AS IT DOES A SURFACE BOUNDARY WILL
MOVE EAST INTO WESTERN KANSAS. JET UPPER LEVEL DYNAMICS APPEAR
LACKING ACROSS WESTERN KANSAS LATE TUESDAY, HOWEVER THERE WILL BE
SOME FORCING DEVELOPING LATE DAY NEAR THIS BOUNDARY THAT WILL BE
LOCATED NEAR WAKEENEY AND DODGE CITY. AT THIS TIME PRECIPITATION
CHANCES TUESDAY NIGHT STILL APPEARS VERY LOW BASED ON THE WEAK
FORCING ALOFT AND WARMING TEMPERATURES IN THE 850-700MB LAYER WHICH
SHOULD SERVE AS A CAP. AS A RESULT WILL CONTINUE TO FAVOR A DRY
FORECAST TUESDAY NIGHT BUT GIVEN THE RETURN OF NEAR 50 DEGREE
SURFACE DEWPOINTS RETURNING ACROSS SOUTH CENTRAL KANSAS WILL
CONTINUE TO FAVOR THE WARMER PREVIOUS FORECAST FOR LOWS WHICH THE
MET NOW APPEARS TO HINTING AT.
THE NEXT IN A SERIES OF UPPER LEVEL DISTURBANCES WILL THEN CROSS OUT
INTO THE PLAINS ON LATE WEDNESDAY AS WARM AIR ADVECTION IMPROVES
NORTH OF A SURFACE BOUNDARY THAT WILL EXTEND FROM WEST TO EAST
ACROSS NORTHERN KANSAS. THIS CONVECTION SHOULD STAY NORTH OF THE I70
CORRIDOR. BASED ON THE NEW 850MB TEMPERATURE TRENDS FROM THE NAM AND
GFS WILL GO AHEAD AN WARM TEMPERATURES UP INTO THE 80 TO 85 DEGREE
RANGE FOR MUCH OF SOUTHWEST KANSAS.
BY LATE WEEK AN UPPER LEVEL RIDGE IS EXPECTED TO DEVELOP ACROSS THE
WESTERN UNITED STATES AS AN UPPER LOW NEAR THE GULF OF ALASKA BEGINS
TO DROP SOUTH/SOUTHEAST. THE NEXT UPPER LEVEL TROUGH WILL MOVE OUT
INTO THE PLAINS ON THURSDAY WHICH WILL ALLOW THE FRONT ACROSS
NORTHERN KANSAS TO CROSS INTO NORTHERN OKLAHOMA BY THURSDAY EVENING.
MOIST UPSLOPE FLOW DEVELOPING NORTH OF THIS FRONT COMBINED WITH THE
LEFT EXIT REGION OF AN UPPER LEVEL JET ROTATING AROUND THIS
DEVELOPING UPPER RIDGE WILL ENHANCE THUNDERSTORM CHANCES ACROSS MUCH
OF WESTERN KANSAS THURSDAY NIGHT. THESE PRECIPITATION CHANCES WILL
END FROM WEST TO EAST EARLY FRIDAY AS THE UPPER RIDGE LOCATED OVER
THE WEST COAST STARTS TO SHIFT EASTWARD TOWARDS THE ROCKIES. AS FOR
TEMPERATURES LATE WEEK AND OVER THE WEEKEND PERIOD...AFTER A COOL
DOWN BEHIND THE FRONT THURSDAY NIGHT AND FRIDAY A WARMING TREND WILL
BEGIN FOR THE WEEKEND PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1230 PM CDT MON APR 16 2012
MAIN CONCERN FOR THE 18Z TAFS IS THE POSSIBILITY OF SHOWERS THIS AFTERNOON.
CIGS WILL REMAIN PRIMARILY VFR THROUGH THE PERIOD. DID INSERT VCSH FOR
THE TERMINALS THIS AFTERNOON. IF IT DOESN`T PRECIPITATE THEN AT LEAST
AN INCREASE OF CUMULUS IS EXPECTED LATER AS A MINOR UL SHORTWAVE TROUGH
SKIRTS ACROSS THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 44 77 48 78 / 30 0 0 0
GCK 41 75 45 77 / 30 0 0 0
EHA 38 77 46 81 / 20 0 0 0
LBL 41 78 47 81 / 30 0 0 0
HYS 42 74 48 75 / 30 0 10 0
P28 46 74 52 79 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...BURGERT
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
212 PM CDT MON APR 16 2012
...UPDATED SYNOPSIS AND SHORT TERM DISCUSSIONS...
.SYNOPSIS...
ISSUED AT 212 PM CDT MON APR 16 2012
THE 16 APRIL 2012 12Z SYNOPTIC MAPS SHOWED A STRONG 125 KT TO 135 KT
300 HPA JET ACROSS MISSOURI. ANOTHER 300 HPA JET STREAK WAS LOCATED
ACROSS QUEBEC. FURTHER UPSTREAM, A 50 KT TO 70 KT 300 HPA JET WAS LOCATED
ACROSS THE PACIFIC NORTHWEST. AT 500 HPA, A MINOR SHORTWAVE TROUGH WAS
MOVING ACROSS THE ROCKIES. MOISTURE ADVECTION DOWNSTREAM OF A 536 DM
LOW WAS OBSERVED ACROSS THE UPPER GREAT LAKES AND INTO THE OHIO RIVER
VALLEY. IN ADDITION, SOME MID LEVEL MOISTURE WAS PUSHING ONSHORE ACROSS
OREGON/WASHINGTON. AT 700 HPA, A RELATIVELY COOL AND DRY AIRMASS HAS
SPREAD OVER THE PLAINS IN THE WAKE OF A DEPARTING SYSTEM. AT 850 HPA,
SOME WRAP AROUND MOISTURE WAS OBSERVED ACROSS MINNESOTA AND STRETCHING
DOWN TO EASTERN KANSAS IN ASSOCIATION WITH A LOW TO MID LEVEL CYCLONE
TO THE NORTHEAST. AT THE SFC, A COLD FRONT WAS ANALYZED FROM SE ONTARIO
TO TEXAS. ANY GULF OF MEXICO MOISTURE WAS SOUTH OF THIS BOUNDARY.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 212 PM CDT MON APR 16 2012
TONIGHT:
VISIBLE SATELLITE AND WSR-88D TRENDS HAVE BEEN ECHOING MODEL OUTPUT,
PARTICULARLY FROM THE HRRR. AS A RESULT, HAVE RELIED HEAVILY ON THIS
MODEL FOR TONIGHT. AN UPPER LEVEL SHORTWAVE TROUGH/400 HPA PV ANOMALY
WILL MOVE ACROSS SOUTHWEST KANSAS THIS EVENING. CONVECTION HAS FORMED
ACROSS SOUTHEAST COLORADO AS A RESULT. EVEN THOUGH DEWPOINTS ARE RUNNING
ONLY IN THE 30S DEG F RANGE, THE HRRR SHOWS SOME WEAK INSTABILITY FORMING.
THIS IS ECHOED IN FORECAST SOUNDINGS ACROSS MY COUNTY WARNING AREA.
100-300 J/KG OF CAPE ALONG WITH FAIRLY STEEP 700 HPA TO 500 HPA WILL
LEAD TO EASTWARD PROPAGATING SHOWERS AND ISOLATED THUNDERSTORMS THROUGH
THE REST OF THIS AFTERNOON AND INTO THE EARLY EVENING. SEVERE WEATHER
IS NOT EXPECTED DUE TO WEAK INSTABILITY/SHEAR. OVERNIGHT LOWS WILL BE SLIGHTLY
WARMER WITH MID 30S DEG F OUT WEST AND MID 40S DEG F ACROSS SOUTH CENTRAL
KANSAS. THE 12Z NAM WAS SHOWING INCREASING 1000-850 HPA MOISTURE, BUT
THINK THIS IS AN OUTLIER COMPARED TO THE REST OF THE MODELS. THE MAIN
IMPLICATIONS FROM THIS WOULD BE AREAS OF STRATUS AND SLIGHTLY WARMER
MINIMUMS UNDER THE CLOUD DECK. WILL HOLD OFF FOR NOW ON THIS SOLUTION.
TOMORROW:
FLAT 500 HPA RIDGING IS EXPECTED ACROSS THE ROCKIES AND HIGH PLAINS
TOMORROW. THIS WILL LEAD TO WESTERLY FLOW ALOFT AND DOWNSLOPE SOUTHWESTERLY
SURFACE TO 600 HPA WINDS. THE ATMOSPHERE BECOMES DEEPLY MIXED TO ABOUT
650 HPA WHICH SUPPORTS WARMER MAXIMUM TEMPERATURES FOR TOMORROW VIA
ADIABATIC COMPRESSIONAL WARMING. THE WIND PROFILE WITHIN THIS LAYER
IS NOT PARTICULARLY STRONG, BUT I DO THINK BREEZY CONDITIONS ARE EXPECTED
AS MIXING AND RESULTANT MOMENTUM TRANSFER DEVELOPS/CONTINUES TOMORROW.
HIGHS WILL BE IN THE 70S DEG F RANGE. NO PRECIPITATION IS EXPECTED AS
SUBSIDENCE IN THE WAKE OF THE TROUGH PREVAILS. A LEE SURFACE TROUGH
ACROSS EASTERN COLORADO WILL CONTINUE AS WELL WITH THE AFOREMENTIONED
PERPENDICULAR FLOW TO THE ROCKIES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 328 AM CDT MON APR 16 2012
THE 00Z RUNS OF THE MEDIUM RANGE MODELS CONTINUE TO BE IN FAIRLY
GOOD AGREEMENT WITH EACH OTHER AND ARE FAIRLY CONSISTENT WITH
PREVIOUS RUNS WITH REGARD TO THE UPPER FLOW PATTERN THIS WEEK. THE
ZONAL PATTERN WILL RESULT IN A WARMING TREND THROUGH MIDWEEK.
A SHORTWAVE TROUGH MOVING OUT OF THE PACIFIC NORTHWEST ON WEDNESDAY
WILL UNDERGO AMPLIFICATION AS IT MOVES OUT OVER THE PLAINS ON
THURSDAY. THE MODELS ALL SHOW A COLD FRONT PUSHING THROUGH SOUTHWEST
KANSAS ON THURSDAY. THE MODELS DEVELOP SOME LIGHT QPF WITH THE
WAVE AND FRONT. THERE IS SOME LIMITED INSTABILITY BUT MODEL
SOUNDINGS ARE NOT OVERLY IMPRESSIVE SO WILL KEEP A SLIGHT CHANCE
FOR SHOWERS AND ISOLATED THUNDERSTORMS ACROSS SOUTHWEST KANSAS
THURSDAY INTO THURSDAY EVENING.
THE MODELS SHOW A SECONDARY SHORTWAVE TROUGH DIVING OUT OF THE
NORTHERN HIGH PLAINS ACROSS KANSAS ON FRIDAY AND SHOW SOME LIGHT
PRECIPITATION WITH THIS WAVE AS WELL. NOT OVERLY CONFIDENT WE WILL
SEE ANYTHING DEVELOP IN THE NORTHWEST FLOW PATTERN BUT WILL LEAVE
IT IN FOR NOW.
DRY WEATHER WILL ROUND OUT THE WEEKEND INTO EARLY NEXT WEEK AS A
HIGH AMPLITUDE RIDGE MOVES INTO THE CENTRAL CONUS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1230 PM CDT MON APR 16 2012
MAIN CONCERN FOR THE 18Z TAFS IS THE POSSIBILITY OF SHOWERS THIS AFTERNOON.
CIGS WILL REMAIN PRIMARILY VFR THROUGH THE PERIOD. DID INSERT VCSH FOR
THE TERMINALS THIS AFTERNOON. IF IT DOESN`T PRECIPITATE THEN AT LEAST
AN INCREASE OF CUMULUS IS EXPECTED LATER AS A MINOR UL SHORTWAVE TROUGH
SKIRTS ACROSS THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 44 77 48 78 / 30 0 0 0
GCK 41 75 45 77 / 30 0 0 0
EHA 38 77 46 81 / 20 0 0 0
LBL 41 78 47 81 / 30 0 0 0
HYS 42 74 48 75 / 30 0 10 0
P28 46 74 52 79 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS JACKSON KY
1007 PM EDT TUE APR 17 2012
.UPDATE...
ISSUED AT 1007 PM EDT TUE APR 17 2012
FORECAST IS PRETTY MUCH ON TRACK THIS EVENING. THE ONLY AMENDMENT TO
THE GRIDDED DATABASE WAS TO PULL THE AREA OF LIKELY (60 TO 70
PERCENT) POPS BACK TO THE WEST A BIT INTO MCCREARY COUNTY ALONG THE
TENNESSEE BORDER. THE BULK OF RAINFALL TONIGHT SHOULD OCCUR UP THE
CUMBERLAND VALLEY AND ALONG THE VIRGINIA BORDER. HRRR WANTS TO
DEVELOP RAINFALL AS FAR NORTH AS I-64 TOWARDS DAWN BUT FEEL MUCH OF
THIS WILL FALL AS VIRGA AND THE INHERITED SMALL POP UP THAT FAR
NORTH SHOULD SUFFICE. HAVE A GOOD NIGHT...
UPDATE ISSUED AT 708 PM EDT TUE APR 17 2012
A FEROCIOUS VIRGA STORM ONGOING OUTSIDE THE WFO THIS EVENING. HARD
TO FIND MUCH EVIDENCE OF ANYTHING REACHING THE GROUND DESPITE GOOD
RETURNS ON RADAR MOVING NORTHWARD UP THE I-75 CORRIDOR.
HOWEVER...KYTC WEB CAM ON I-75 IN WHITLEY COUNTY DOES SHOW A WET
INTERSTATE. THIS SHOWER ACTIVITY SHOULD REMAIN SCATTERED AND MAINLY
CONFINED TO OUR UPPER CUMBERLAND REGION THIS EVENING BEFORE
EXPANDING IN COVERAGE OVER FAR SOUTHEAST KENTUCKY OVERNIGHT AS A
PERIOD OF ISENTROPIC LIFT OCCURS IN RESPONSE TO LOW PRESSURE
SCOOTING BY TO OUR SOUTHEAST. 18Z MODELS HAVE BROUGHT INCREASED
CONFIDENCE IN MEASURABLE RAINFALL ALONG THE VA BORDER AND HAVE
INCREASED POPS UP TO 80 PERCENT THERE...AND INTO THE 60 TO 70
PERCENT RANGE AS FAR WEST AS A WILLIAMSBURG-HAZARD-PIKEVILLE LINE.
THE RAIN WILL BE ONGOING OVER FAR SOUTHEAST KENTUCKY INTO EARLY
WEDNESDAY MORNING BEFORE MOVING OFF TO THE EAST LATER IN THE
MORNING.
OTHER THAN THE POP ADJUSTMENTS...SKY COVER WAS ALSO INCREASED WITH
OVERCAST SKIES BEING OBSERVED FOR MOST OF THE FORECAST AREA. NO
OTHER CHANGES WERE NEEDED AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 155 PM EDT TUE APR 17 2012
LOW PRESSURE DEVELOPING AT THE SFC IN THE WRN GULF IS IN RESPONSE TO
A 50H SHORT WAVE CROSSING THE LOWER MISS RIVER VALLEY. THIS WAVE WILL
CONTINUE TO TRACK EAST ACROSS THE GULF COAST STATES UNTIL REACHING
THE CAROLINA COAST BY LATE WED NIGHT. THE SFC LOW WILL ALSO MOVE TO
THE EAST ALONG THE GULF COAST WITH MOISTURE PUSHING NORTH INTO THE
TENN RIVER VALLEY AHEAD OF IT. ALTHOUGH MOST OF THE PCPN WILL REMAIN
SOUTH OF OUR BORDER...SOME PCPN IS LIKELY TO SPILL INTO OUR SERN
COUNTIES TONIGHT AS THE MOISTURE IS LIFTED OVER THE COLD FRONT THAT
HAS STALLED JUST TO OUR SOUTH. EXPECTING THE PCPN TO BE DRAGGED OUT
OF THE COMMONWEALTH AS THE LOW MOVES EAST OF THE MTNS AND THE
APPALACHIAN MTNS EFFECTIVELY BLOCK MOST OF THE LOW LEVEL FLOW AND
DOWNSLOPING CANCELS THE REST. AS THE PCPN MOVES EAST THE CLOUDS
SHOULD FOLLOW...ESPECIALLY WITH THE COOLING NIGHT TIME CONDITIONS WED
NIGHT. EXPECTING TEMPERATURES TONIGHT AND WED NIGHT IN THE 40S WITH
HIGHS ON WED IN THE UPPER 60S...WHICH IS NORMAL FOR THIS TIME OF THE
YEAR. MAY BE SOME FOG LATE WED NIGHT...BUT ALSO LOOKING FOR SOME
DRIER AIR TO CYCLE INTO ERN KY AS A WEAK RIDGE BUILDS DOWN FROM THE
GREAT LAKES. WILL WAIT TO SEE HOW MOIST IT REMAINS ON WED TO CALL FOR
FOG WED NIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 228 PM EDT TUE APR 17 2012
HIGH PRESSURE WILL BE FIRMLY IN CONTROL ACROSS EASTERN KENTUCKY TO
START THE PERIOD WITH THE SURFACE RIDGING EXTENDING FROM THE MID
ATLANTIC STATES...INTO THE SOUTHEASTERN US. THE MID LEVEL RIDGE WILL
NOSE NORTH ALONG THE AXIS OF THE APPALACHIANS. THIS WILL KEEP OUR
WEATHER QUIET AND PLEASANT FROM THURSDAY THROUGH FRIDAY. GFS TRIES TO
BREAK OUT SOME PRECIPITATION FRIDAY AFTERNOON...BUT AS IS NORMALLY
THE CASE...IT IS LIKELY BRINGING SURFACE MOISTURE IN A BIT TOO
FAST...SO PLAN TO HAVE A DRY FORECAST THROUGH FRIDAY EVENING.
MEANWHILE...ON FRIDAY...AN UPPER LEVEL TROUGH WILL DEEPEN ACROSS THE
HIGH PLAINS. THEN...MODELS DEPICT THE BEST SHORTWAVE ENERGY
GENERATING A CUT OFF LOW OVER THE SOUTHERN MISSISSIPPI RIVER VALLEY
FRIDAY NIGHT. NOT HIGHLY CONFIDENT IF THIS FEATURE WILL BECOME
COMPLETELY CUT OFF. GIVEN THE POSITIVE NAO PRESENTLY...IT WOULD FAVOR
MORE PROGRESSIVE FLOW ACROSS OUR AREA. THIS IS WHERE MODELS ARE
HAVING A TOUGH TIME IN HOW TO HANDLE THIS CUT OFF FEATURE. THE ECMWF
HAS COME IN WITH A BIT MORE PROGRESSIVE PATTERN (SUPPORTED BY THE NAO
AND IN LINE WITH ITS ENSEMBLE MEAN)...WHILE THE GFS CONTINUES TO BE
TOO DEEP AND CUT OFF WITH ITS SYSTEM. THUS...I REALLY PREFER THE
FASTER ECMWF SOLUTION THIS WEEKEND. AS THIS SYSTEM ATTEMPTS TO CUT
OFF OVER THE LOWER MISSISSIPPI RIVER VALLEY...IT WILL BEGIN TO PUSH
EAST...EVENTUALLY DRAGGING THE MID LEVEL TROUGH AXIS ACROSS OUR NECK
OF THE WOODS. IF THE FASTER SOLUTION PANS OUT...THIS WILL HAPPEN ON
SATURDAY. PRESENTLY...THE INHERITED FORECAST HAD THE HIGHEST POPS ON
SATURDAY...SO THIS SEEMS ON TRACK WITH THIS THINKING. WILL BACK OFF
POPS FOR THE REMAINDER OF THE WEEKEND...FAVORING THE FASTER SOLUTION.
WITH THE LESS CUT OFF SYSTEM...WE MAY NOT SEE AS COLD OF AIR GET
DRAWN SOUTH IN THE WAKE OF THE SYSTEM...HOPEFULLY LIMITING ANY FROST
CONCERNS BY LATE IN THE WEEKEND OR EARLY NEXT WEEK. HOWEVER...THE
TREND FOR COOLER WEATHER WILL CONTINUE INTO EARLY NEXT WEEK. HIGH
PRESSURE WILL BRING QUIET WEATHER TO START NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 740 PM EDT TUE APR 17 2012
WIDELY SCATTERED SHOWERS WILL MOVE NORTH INTO SOUTHEAST KENTUCKY
THROUGH THE EVENING HOURS AS LOW PRESSURE TRACKS ALONG A STALLED
FRONTAL BOUNDARY LOCATED TO OUR SOUTHEAST. THE RAIN WILL BECOME MORE
WIDESPREAD OVERNIGHT ALONG THE VIRGINIA BORDER...MAINLY TO THE
SOUTHEAST OF OUR TAF SITES. 1A6...I35 AND PBX WILL LIKELY BE
AFFECTED BY A PERIOD OF LIGHT RAIN AND MVFR TO IFR CIGS BETWEEN 06Z
AND 15Z. TO THE NORTHWEST...CONDITIONS ARE EXPECTED TO REMAIN VFR
FOR OUR TAF SITES UNTIL LATE TONIGHT/EARLY WEDNESDAY MORNING WHEN
CIGS SHOULD LOWER INTO THE MVFR RANGE. SOME IMPROVEMENT IS EXPECTED
LATE IN THE PERIOD AT SME...BUT THE MVFR CIGS SHOULD HOLD IN MOST OF
THE DAY ON WEDNESDAY FOR POINTS EAST OF THERE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ABE
SHORT TERM...DUSTY
LONG TERM....KAS
AVIATION...ABE
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
846 PM CDT TUE APR 17 2012
.UPDATE...
ISSUED AT 839 PM CDT TUE APR 17 2012
INTERIM EVENING UPDATE TO ADDRESS GRADIENT DROP IN TEMPERATURES
DUE TO SHARP CHANGES FROM CLEAR TO OPAQUE CLOUD COVER OVERNIGHT.
WITH THE SHARP DROP OFF OF THE WIND EXPECTED UNDER THE
NOCTURNAL/SUBSIDENCE INVERSION...THE TEMPERATURE/DEWPOINT
DIFFERENCE WILL BE A LITTLE DIFFICULT TO PINPOINT.
UTILIZED THE 13KM RUC/3KM HRRR GUIDANCE TO DEPICT THE BEST AREAS
FOR OVERNIGHT FOG PRODUCTION OVERNIGHT. FOR MOST OF THE
NIGHT...THE FOG WILL BE QUITE VARIABLE IN TIME/SPACE. THE MOST
WIDESPREAD FOG DEVELOPMENT...ALBEIT PATCHY...SHOULD OCCUR AROUND
DAYBREAK OVER THE SOUTHEAST MISSOURI FOOTHILLS...BUT SHOULD BURN
OFF WITHIN AN HOUR OR SO AFTER SUNRISE.
UPDATE ISSUED AT 633 PM CDT TUE APR 17 2012
FOR AVIATION SECTION ONLY. NO MAJOR CHANGES TO THE NEAR TERM.
&&
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 156 PM CDT TUE APR 17 2012
NOT MUCH GOING ON IN THE SHORT TERM. THE PASSAGE OF AN H5 TROF
PASSING ACROSS THE REGION OVERNIGHT COMBINED WITH OVERRUNNING
MOISTURE ASSOCIATED WITH AN INVERTED SURFACE TROF WILL CONTINUE TO
PRODUCE SHOWERS TO THE SOUTH AND EAST OF OUR CWA.
WITH ALL MODELS SHOWING DEEPER MOISTURE REMAINING TO THE SOUTH AND
EAST OF OUR CWA AS WELL AS THE EASTWARD PROGRESSION OF THE
BAROCLINIC LEAF ASSOCIATED WITH THE TROF...DO NOT THINK PRECIP WILL
MAKE IT INTO THE SOUTHEAST CORNER OF OUR CWA THIS EVENING...BUT IT
WILL COME VERY CLOSE. WILL CONTINUE TO MONITOR CLOSELY JUST IN CASE.
ONCE THE MOISTURE AND CLOUDS SHIFT TO EAST WITH THE EXIT OF THE TROF...
WEAK HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH AT LEAST WEDNESDAY
NIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 156 PM CDT TUE APR 17 2012
HIGH PRESSURE SLIDING OFF THE EAST COAST THURSDAY INTO THURSDAY
NIGHT WILL KEEP CONDITIONS DRY. INCREASING SOUTH WINDS AHEAD OF AN
APPROACHING COLD FRONT WILL CONTINUE TO PROVIDE UNSEASONABLY WARM
TEMPERATURES. THE 00Z ECMWF IS THE MORE CONSISTENT MODEL WITH ITS
RUN YESTERDAY...SPREADING SHOWERS AND SOME THUNDERSTORMS ACROSS THE
PAH FORECAST AREA MAINLY LATE FRIDAY INTO FRIDAY NIGHT. GFS AND THE
12Z ECMWF NOW HOLD OFF ANY PRECIP UNTIL LATE FRIDAY NIGHT AND
ESPECIALLY INTO SATURDAY...WHICH IS MUCH SLOWER THAN YESTERDAY.
CONSENSUS IS TO LEAN TOWARD THE 00Z ECMWF FOR NOW...WHICH DOES LEAN
TOWARD A LITTLE BIT SLOWER TREND. WENT WITH SLIGHT TO LOW CHANCE
POPS FRIDAY MORNING FOR THE WEST HALF OF THE PAH FORECAST
AREA...THEN GOOD CHANCE POPS FOR ALL BUT THE SOUTHEAST THIRD OF OUR
AREA FRIDAY AFTERNOON. STAYED WITH HIGH CHANCE POPS AS OPPOSED TO
LIKELY FRIDAY NIGHT WITH THE SLOWER GFS AND 12Z ECMWF SOLUTIONS
CASTING QUITE A BIT OF DOUBT. LIKELY POPS WILL PROBABLY BE
REASONABLE AT SOME POINT DURING THIS EVENT...BUT WANT TO SEE MORE
TIMING CONSISTENCY BEFORE GOING HIGHER WITH POPS. ON
SATURDAY...WENT WITH CHANCE POPS SOUTHEAST TO SLIGHT CHANCE WEST AND
NORTHWEST BEHIND THE FRONT...WITH DRY CONDITIONS RETURNING BY
SATURDAY NIGHT.
SIGNIFICANTLY COOLER TEMPERATURES ARE EXPECTED BEHIND THE COLD
FRONT. READINGS WILL BE 10 TO 15 DEGREES COOLER THAN MID
WEEK...WHICH WILL PUT US A FEW DEGREES BELOW SEASONAL NORMALS. HIGH
PRESSURE BUILDING OVER THE SOUTHERN PLAINS MONDAY WILL SLIDE EAST
OVER THE GULF COAST STATES TUESDAY. THIS WILL BEGIN A WARM UP ON
MONDAY...WITH SLIGHTLY ABOVE NORMAL TEMPERATURES RETURNING BY
TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 633 PM CDT TUE APR 17 2012
EXPECT CIRRUS SHIELD TO ERODE FROM WEST TO EAST TONIGHT. WINDS WILL
ALSO GO CALM...BUT BELIEVE DRY AIR JUST OF THE SURFACE SHOULD
PRECLUDE MUCH FOG DEVELOPMENT...BEST CHC WILL BE AT THE CLIMO
FAVORED KCGI SITE...WHERE VSBYS MAY BRIEFLY FALL INTO IFR FOR A
FEW HOURS TOWARD SUNRISE. WILL NEED TO MONITOR FOR SHALLOW FOG
DEVELOPMENT EVERY SITE TOWARD MORNING THO.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...JP
LONG TERM....RST
AVIATION...GM
AREA FORECAST DISCUSSION
NWS PADUCAH KY
200 AM CDT MON APR 16 2012
.UPDATE...
ISSUED AT 155 AM CDT MON APR 16 2012
MADE ADJUSTMENTS TO POPS/WX AND TEMPERATURES THROUGH 18Z. USED A
COMBINATION OF SHORT TERM MODELS TO GET THE FORECAST. SLOWED DOWN
THE DEPARTURE OF PRECIPITATION OF THE PRECIPITATION IN THE EAST.
THE FINE LINE ASSOCIATED WITH THE WIND SHIFT STILL PRODUCING WIND
GUSTS TO 30+ MPH WITH SOME DECREASE BEHIND THE LINE. THE FINE LINE
HAS OUTRACED THE MAIN PRECIPITATION SHIELD. ONLY ISOLATED
LIGHTNING STRIKES EXPECTED FOR THE REST OF THE NIGHT.
UPDATE ISSUED AT 844 PM CDT SUN APR 15 2012
THIS NEAR TERM DISCUSSION IS ISSUED TO ACKNOWLEDGE THE EXPIRATION
OF THE EARLIER LAKE WIND ADVISORY AT 7 PM CDT...AND THE RECENT
CANCELLATION OF THE TORNADO WATCH NUMBER 180 FOR
CARTER...RIPLEY...WAYNE AND BUTLER COUNTIES IN SOUTHEAST MISSOURI.
GOES IMAGERY DERIVED LIFTED INDEX VALUES HAVE BEEN SHOWING A
GRADUAL TREND TOWARD A MORE STABLE ENVIRONMENT AND THE
PRECIPITABLE WATER VALUES SUGGEST THAT THE MAIN PLUME WILL BE
FIXED WITH THE VICINITY OF CURRENT CONVECTION.
THE PREFERRED 3KM HRRR MODEL GUIDANCE SUGGESTS THAT THE SURFACE-
BASED PEAK HELICITIES /ALSO SUGGESTED BY THE 4KM NAM-WRF...12KM
NAM AND 40KM GFS GUIDANCE ON SATURDAY/ AND CAPE WOULD DIMINISH
AFTER MOVING OUT OF SOUTHEAST MISSOURI BETWEEN THE 23Z SUNDAY -
03Z MONDAY /6-9 PM CDT SUNDAY NIGHT/.
WITH THAT IN MIND...ATTEMPTED TO BLEND THE HRRR GUIDANCE TIMING OF
THE PRECIPITATION ACROSS THE WFO PAH CWA FOR THE REST OF TONIGHT
AND INTO MONDAY MORNING. IN ADDITION...UTILIZED DIFFERENTIAL
POP/WEATHER FOR THUNDERSTORMS VS. RAINSHOWERS AS THE ELEVATED
INSTABILITY DECREASES OVERIGHT AND INTO MONDAY MORNING.
WILL LIKELY MAKE ANOTHER INTERIM UPDATE BEFORE MIDNIGHT TO ADDRESS
TEMPERATURES AND WINDS IN AND AROUND THE CONVECTIVE RAIN SHIELD.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 205 PM CDT SUN APR 15 2012
THE MAIN FOCUS IN THE SHORT TERM WILL BE THE PASSAGE OF A COLD
FRONT LATE TONIGHT INTO MONDAY MORNING AND THE SHOWERS...
THUNDERSTORMS...AND OTHER WEATHER PHENOMENA ASSOCIATED WITH IT.
A LINE OF THUNDERSTORMS BISECTING THE STATE OF MISSOURI FROM
NORTHEAST TO SOUTHWEST AT THE TIME OF THIS WRITING IS EXPECTED TO
PROGRESS EASTWARD WITH THE AFOREMENTIONED FRONTAL SYSTEM THIS
EVENING AND OVERNIGHT.
AS THE SYSTEM MOVES EASTWARD THIS AFTERNOON AND EVENING...MODELS
ARE INDICATING AN INCREASE IN INSTABILITY AND SHEAR VALUES. WITH
ML CAPE VALUES APPROACHING 2000 J/KG AND DEEP LAYER SHEAR OF 50+
KTS...EXPECT STORMS TO INTENSIFY INTO A QLCS WITH THE POSSIBILITY
OF A COUPLE OF EMBEDDED SUPERCELLS.
BY LATE EVENING INTO THE EARLY MORNING HOURS...STORMS WILL LIKELY
WEAKEN AS INSTABILITY AND WIND SHEAR DECREASE A BIT. AS RESULT...
THE STORM PREDICTION CENTER HAS ALL BUT THE EASTERN THIRD OF OUR
CWA IN A SLIGHT RISK AREA FOR SEVERE THUNDERSTORMS. STORMS SHOULD BE
EXITING THE SOUTHEAST CORNER OF OUR CWA BY 3-4 PM MONDAY AFTERNOON.
AS IS OFTEN THE CASE...MODEL RUNS CONTINUE TO SLOW DOWN THE FORWARD
PROGRESS OF A PARTICULAR SYSTEM...SO LATER SHIFTS MAY HAVE TO
ADJUST ACCORDINGLY. IN THE WAKE OF THIS SYSTEM...HIGH PRESSURE
WILL DOMINATE THROUGH THE END OF THE SHORT TERM PERIOD.
GUSTY SOUTH WINDS OF 20 TO 30 MPH THIS AFTERNOON WILL DECREASE TO
10 TO 20 MPH AND VEER AROUND TO THE SOUTHWEST OVERNIGHT...THEN OUT
OF THE WEST STARTING MONDAY MORNING.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 205 PM CDT SUN APR 15 2012
BY MID WEEK...A ZONAL FLOW PATTERN WILL BECOME ESTABLISHED ACROSS
THE NATIONS MID SECTION. AS HIGH PRESSURE DEPARTS TO THE EAST...WARM
SOUTHERLY WINDS WILL RETURN IN THE LOW LEVELS. TEMPERATURES ARE
FORECAST TO REACH THE MID TO UPPER 70S BOTH WEDNESDAY AND THURSDAY
AFTERNOONS WITH PLENTY OF SUNSHINE BOTH DAYS.
THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL RETURN TO THE FORECAST
LATE THURSDAY INTO FRIDAY AS A DEVELOPING STORM SYSTEM APPROACHES
FROM THE PLAINS. DETERMINISTIC MODELS HAVE BEEN RATHER INCONSISTENT
ON TIMING THIS SYSTEM. MOST RECENT GFS OPERATIONAL RUNS HAVE FAVORED
A DEEPER AND SLOWER SOLUTION...WHILE RECENT ECMWF RUNS HAVE BEEN
FAIRLY CONSISTENT WITH A MORE PROGRESSIVE SOLUTION THAT SHIFTS MUCH
OF THE PRECIPITATION TO THE EAST OF THE AREA BY THE WEEKEND. THE
LATEST GFS AND ECMWF ENSEMBLES TEND TO FAVOR THIS APPROACH. AS A
RESULT...CURRENT FORECAST INCLUDES INCREASING SHOWER AND STORM
CHANCES THURSDAY NIGHT OVER THE WEST...PEAKING FRIDAY AND FRIDAY
EVENING...THEN DEPARTING SOUTHWEST INDIANA AND WESTERN KENTUCKY LATE
FRIDAY NIGHT AND EARLY SATURDAY.
IN THE WAKE OF THIS SYSTEM...COOLER WEATHER WILL RETURN NEXT WEEKEND
AS A NORTHWEST UPPER LEVEL FLOW PATTERN TAKES HOLD. HIGHS WILL DROP
BACK INTO THE 60S...WITH LOWS IN THE 40S BOTH WEEKEND DAYS. BOTH THE
15/12Z GFS AND ECMWF HINT AT THE POSSIBILITY FOR SOME VERY LIGHT
RAIN SATURDAY NIGHT AND SUNDAY. HOWEVER...GIVEN THE LOW CONFIDENCE
THAT FAR OUT...WILL KEEP CONDITIONS DRY FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1200 AM CDT MON APR 16 2012
AT 0455Z...LEADING EDGE OF THE CONVECTIVE ACTIVITY RAN FROM KFWC TO
KPAH. WINDS SHIFT BRIEFLY WEST AND GUST 30 TO 35 KTS...THEN BACK
TO SSW. LIGHTNING CONTINUES TO FADE...SO THUNDER MAY BE LIMITED.
HOWEVER...WILL CARRY SHRA AND TEMPO TSRA AS THE ACTIVITY MOVES
THROUGH OVER THE NEXT FEW HOURS. AFTER THAT...CLOUDS CLEAR IN THE
WAKE OF THE ACTIVITY...WITH WINDS VEERING MORE TO THE WEST...GUSTY
MAINLY THROUGH THE MORNING HOURS...TAILING OFF IN THE AFTERNOON.
WINDS SHOULD GO LIGHT MONDAY EVENING...WITH HIGH CLOUDS MOVING
BACK OVER THE AREA MAINLY EAST OF THE MISSISSIPPI RIVER.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...PS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1200 AM CDT MON APR 16 2012
.UPDATE...
ISSUED AT 844 PM CDT SUN APR 15 2012
THIS NEAR TERM DISCUSSION IS ISSUED TO ACKNOWLEDGE THE EXPIRATION
OF THE EARLIER LAKE WIND ADVISORY AT 7 PM CDT...AND THE RECENT
CANCELLATION OF THE TORNADO WATCH NUMBER 180 FOR
CARTER...RIPLEY...WAYNE AND BUTLER COUNTIES IN SOUTHEAST MISSOURI.
GOES IMAGERY DERIVED LIFTED INDEX VALUES HAVE BEEN SHOWING A
GRADUAL TREND TOWARD A MORE STABLE ENVIRONMENT AND THE
PRECIPITABLE WATER VALUES SUGGEST THAT THE MAIN PLUME WILL BE
FIXED WITH THE VICINITY OF CURRENT CONVECTION.
THE PREFERRED 3KM HRRR MODEL GUIDANCE SUGGESTS THAT THE SURFACE-
BASED PEAK HELICITIES /ALSO SUGGESTED BY THE 4KM NAM-WRF...12KM
NAM AND 40KM GFS GUIDANCE ON SATURDAY/ AND CAPE WOULD DIMINISH
AFTER MOVING OUT OF SOUTHEAST MISSOURI BETWEEN THE 23Z SUNDAY -
03Z MONDAY /6-9 PM CDT SUNDAY NIGHT/.
WITH THAT IN MIND...ATTEMPTED TO BLEND THE HRRR GUIDANCE TIMING OF
THE PRECIPITATION ACROSS THE WFO PAH CWA FOR THE REST OF TONIGHT
AND INTO MONDAY MORNING. IN ADDITION...UTILIZED DIFFERENTIAL
POP/WEATHER FOR THUNDERSTORMS VS. RAINSHOWERS AS THE ELEVATED
INSTABILITY DECREASES OVERIGHT AND INTO MONDAY MORNING.
WILL LIKELY MAKE ANOTHER INTERIM UPDATE BEFORE MIDNIGHT TO ADDRESS
TEMPERATURES AND WINDS IN AND AROUND THE CONVECTIVE RAIN SHIELD.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 205 PM CDT SUN APR 15 2012
THE MAIN FOCUS IN THE SHORT TERM WILL BE THE PASSAGE OF A COLD
FRONT LATE TONIGHT INTO MONDAY MORNING AND THE SHOWERS...
THUNDERSTORMS...AND OTHER WEATHER PHENOMENA ASSOCIATED WITH IT.
A LINE OF THUNDERSTORMS BISECTING THE STATE OF MISSOURI FROM
NORTHEAST TO SOUTHWEST AT THE TIME OF THIS WRITING IS EXPECTED TO
PROGRESS EASTWARD WITH THE AFOREMENTIONED FRONTAL SYSTEM THIS
EVENING AND OVERNIGHT.
AS THE SYSTEM MOVES EASTWARD THIS AFTERNOON AND EVENING...MODELS
ARE INDICATING AN INCREASE IN INSTABILITY AND SHEAR VALUES. WITH
ML CAPE VALUES APPROACHING 2000 J/KG AND DEEP LAYER SHEAR OF 50+
KTS...EXPECT STORMS TO INTENSIFY INTO A QLCS WITH THE POSSIBILITY
OF A COUPLE OF EMBEDDED SUPERCELLS.
BY LATE EVENING INTO THE EARLY MORNING HOURS...STORMS WILL LIKELY
WEAKEN AS INSTABILITY AND WIND SHEAR DECREASE A BIT. AS RESULT...
THE STORM PREDICTION CENTER HAS ALL BUT THE EASTERN THIRD OF OUR
CWA IN A SLIGHT RISK AREA FOR SEVERE THUNDERSTORMS. STORMS SHOULD BE
EXITING THE SOUTHEAST CORNER OF OUR CWA BY 3-4 PM MONDAY AFTERNOON.
AS IS OFTEN THE CASE...MODEL RUNS CONTINUE TO SLOW DOWN THE FORWARD
PROGRESS OF A PARTICULAR SYSTEM...SO LATER SHIFTS MAY HAVE TO
ADJUST ACCORDINGLY. IN THE WAKE OF THIS SYSTEM...HIGH PRESSURE
WILL DOMINATE THROUGH THE END OF THE SHORT TERM PERIOD.
GUSTY SOUTH WINDS OF 20 TO 30 MPH THIS AFTERNOON WILL DECREASE TO
10 TO 20 MPH AND VEER AROUND TO THE SOUTHWEST OVERNIGHT...THEN OUT
OF THE WEST STARTING MONDAY MORNING.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 205 PM CDT SUN APR 15 2012
BY MID WEEK...A ZONAL FLOW PATTERN WILL BECOME ESTABLISHED ACROSS
THE NATIONS MID SECTION. AS HIGH PRESSURE DEPARTS TO THE EAST...WARM
SOUTHERLY WINDS WILL RETURN IN THE LOW LEVELS. TEMPERATURES ARE
FORECAST TO REACH THE MID TO UPPER 70S BOTH WEDNESDAY AND THURSDAY
AFTERNOONS WITH PLENTY OF SUNSHINE BOTH DAYS.
THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL RETURN TO THE FORECAST
LATE THURSDAY INTO FRIDAY AS A DEVELOPING STORM SYSTEM APPROACHES
FROM THE PLAINS. DETERMINISTIC MODELS HAVE BEEN RATHER INCONSISTENT
ON TIMING THIS SYSTEM. MOST RECENT GFS OPERATIONAL RUNS HAVE FAVORED
A DEEPER AND SLOWER SOLUTION...WHILE RECENT ECMWF RUNS HAVE BEEN
FAIRLY CONSISTENT WITH A MORE PROGRESSIVE SOLUTION THAT SHIFTS MUCH
OF THE PRECIPITATION TO THE EAST OF THE AREA BY THE WEEKEND. THE
LATEST GFS AND ECMWF ENSEMBLES TEND TO FAVOR THIS APPROACH. AS A
RESULT...CURRENT FORECAST INCLUDES INCREASING SHOWER AND STORM
CHANCES THURSDAY NIGHT OVER THE WEST...PEAKING FRIDAY AND FRIDAY
EVENING...THEN DEPARTING SOUTHWEST INDIANA AND WESTERN KENTUCKY LATE
FRIDAY NIGHT AND EARLY SATURDAY.
IN THE WAKE OF THIS SYSTEM...COOLER WEATHER WILL RETURN NEXT WEEKEND
AS A NORTHWEST UPPER LEVEL FLOW PATTERN TAKES HOLD. HIGHS WILL DROP
BACK INTO THE 60S...WITH LOWS IN THE 40S BOTH WEEKEND DAYS. BOTH THE
15/12Z GFS AND ECMWF HINT AT THE POSSIBILITY FOR SOME VERY LIGHT
RAIN SATURDAY NIGHT AND SUNDAY. HOWEVER...GIVEN THE LOW CONFIDENCE
THAT FAR OUT...WILL KEEP CONDITIONS DRY FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1200 AM CDT MON APR 16 2012
AT 0455Z...LEADING EDGE OF THE CONVECTIVE ACTIVITY RAN FROM KFWC TO
KPAH. WINDS SHIFT BRIEFLY WEST AND GUST 30 TO 35 KTS...THEN BACK
TO SSW. LIGHTNING CONTINUES TO FADE...SO THUNDER MAY BE LIMITED.
HOWEVER...WILL CARRY SHRA AND TEMPO TSRA AS THE ACTIVITY MOVES
THROUGH OVER THE NEXT FEW HOURS. AFTER THAT...CLOUDS CLEAR IN THE
WAKE OF THE ACTIVITY...WITH WINDS VEERING MORE TO THE WEST...GUSTY
MAINLY THROUGH THE MORNING HOURS...TAILING OFF IN THE AFTERNOON.
WINDS SHOULD GO LIGHT MONDAY EVENING...WITH HIGH CLOUDS MOVING
BACK OVER THE AREA MAINLY EAST OF THE MISSISSIPPI RIVER.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1154 PM CDT SUN APR 15 2012
.DISCUSSION...
06Z TAF ISSUANCE.
&&
.AVIATION...
TSRA CONTINUES TO INCREASE ACROSS SE TX THIS EVENING...NOW JUST W
OF BPT N TO TOLEDO BEND. EXPECTING THE STRONGEST TSRA POSSIBLE
BETWEEN 06-12Z FOR AEX/BPT/LCH...AND 10-14Z FOR LFT/ARA. FOR
THIS...PLACED TEMPO GROUPS FOR TSRA ALONG WITH IFR CEILINGS/VSBY
DURING THESE TIME PERIODS. FOR THE REMAINDER OF THE FORECAST
PERIOD...THE BOUNDARY IS EXPECTING TO STALL ACROSS SE TX THRU C
LA...YIELDING SHRA WITH INTERMITTENT TSRA DURING THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 934 PM CDT SUN APR 15 2012/
UPDATE...
LINE OF SHOWERS AND A FEW STRONG THUNDERSTORMS BECOMING A BIT MORE
ORGANIZED OVER EASTERN TEXAS ALONG SURFACE BOUNDARY. WATER VAPOR
IMAGERY SHOWS AN UPPER LEVEL LOW OVER THE UPPER MIDWEST WITH AN
UPPER LEVEL DISTURBANCE AND JET STREAK SWINGING AROUND IT AND OUT
OF THE SOUTHWEST U.S. THIS DISTURBANCE WILL BEGIN TO ENHANCE UPPER
LEVEL DIVERGENCE AND PLACE THE FORECAST AREA IN A MORE FAVORABLE
RIGHT ENTRANCE REGION OF JET OVERNIGHT...AND HELP KICK THE SURFACE
BOUNDARY SLOWLY TO THE EAST...WITH BEST DEVELOPMENT OF
THUNDERSTORM ACTIVITY ALONG THE LINE NOTED AROUND AND AFTER
16/09Z.
LIKE THE LATEST RUC HANDLING OF THE CONVECTION AND WILL USE A
COMBO OF THE 16/00Z RUC AND NAM12 FOR THE REMAINDER OF THE NIGHT.
IN THIS SCENARIO...BEST CHANCE OF RAIN WILL BE WEST OF AN
ALEXANDRIA TO LAKE CHARLES LINE...AND WILL HAVE LIKELY POPS IN
THESE AREAS...TAPERING TO CHANCE OVER ACADIANA...MAINLY FOR SOME
STRAY SHOWERS DEVELOPING AHEAD OF THE LINE OFF THE GULF AND INTO
SOUTH CENTRAL LOUISIANA BEFORE DAYBREAK. SEVERE THREAT SEEMS TO
BECOMING MORE LIMITED...WITH MARGINAL LOW LEVEL INSTABILITY...
HOWEVER MAYBE SOME ISOLATED STRONG WIND GUSTS OR HAIL...AND
FREQUENT LIGHTNING WILL STILL BE POSSIBLE. PRECIPITABLE WATER ON
LATEST KLCH SOUNDING WAS AT 1.5 INCHES AND IS EXPECTED TO CONTINUE
TO INCREASE. THUS...WITH THE EXPECTED SLOW MOVEMENT OF THE SURFACE
BOUNDARY...SOME LOCALLY HEAVY RAINFALL WILL BE POSSIBLE AND WILL
KEEP MENTION OF THAT IN THE WEATHER GRIDS. RAINFALL RATES AROUND 2
INCHES PER HOUR WILL BE POSSIBLE WITH THE STORMS ALONG THE LINE.
FOR THE COASTAL WATERS...GRADIENT BEGINNING TO RELAX SOME. SMALL
CRAFT ADVISORY IS EXPECTED TO CONTINUE THROUGH-OUT THE NIGHT INTO
MONDAY NIGHT FOR THE OUTER WATERS...AS IT WILL TAKE SOME TIME FOR
THE SEAS TO FALL BELOW 7 FEET.
RUA
PREV DISCUSSION... /ISSUED 727 PM CDT SUN APR 15 2012/
UPDATE...
HAVE UPDATED FORECAST TO REMOVE WIND ADVISORY HEADLINE. WIND
ADVISORY WAS ALLOWED TO EXPIRE AT 7 PM CDT AS SUSTAINED SOUTHERLY
WINDS HAVE DECREASED TO BELOW 20 MPH.
UPPER AIR SOUNDING FROM KLCH AT 16/00Z SHOWS AN INCREASE IN
MOISTURE WITH PRECIPITABLE WATER NOW UP TO 1.5 INCHES COMPARED TO
0.9 INCHES 12 HOURS AGO. CAP HAS ALSO WEAKENED...BUT STILL ENOUGH
TO KEEP THUNDERSTORM ACTIVITY IN CHECK. SCATTERED ACTIVITY
SKIRTING THE WESTERN PORTIONS OF THE FORECAST AREA...WHERE SURFACE
BOUNDARY HAS PROVIDED ENOUGH LIFT TO GET SOME ACTIVITY GOING. AT
THE PRESENT...NAM12 SEEMS TO BE HAVING A BETTER HANDLE ON
CONVECTION THAN OTHER MODELS. ALTHOUGH...RIGHT ENTRANCE REGION OF
JET IS EXPECTED TO NEAR FORECAST AREA OVERNIGHT...WHICH MAY BE
WHAT IS NEEDED TO GET CONVECTION INITIATED AND MORE ORGANIZED...WHICH
IS WHAT OTHER GUIDANCE IS BANKING ON. IF CURRENT TRENDS CONTINUE...MAY
HAVE TO ADJUST POPS DOWNWARD EAST OF A LAKE CHARLES TO LEESVILLE
LINE FOR THE OVERNIGHT PERIOD. AT THIS POINT...WITH INCREASING
MOISTURE CONTENT...AND EXPECTED SLOW MOVEMENT OF SURFACE BOUNDARY...HEAVY
RAINFALL MAY BE THE BIGGEST CONCERN LATER ON TONIGHT INTO MONDAY.
RUA
PREV DISCUSSION... /ISSUED 622 PM CDT SUN APR 15 2012/
DISCUSSION...
00Z TAF ISSUANCE.
AVIATION...
SHRA/TSRA BEGINNING TO INCREASE JUST WEST OF THE REGION...APPROACHING
LFK. SCT SHRA/TSRA WILL BE POSSIBLE FURTHER E ACROSS SE TX/C AND
SW LA BY 02-04Z...AND ACROSS SC LA BY 04-06Z. EXPECTING THE
STRONGEST TSRA POSSIBLE BETWEEN 04-08Z FOR AEX/BPT/LCH...AND
08-12Z FOR LFT/ARA. FOR THIS...PLACED TEMPO GROUPS FOR TSRA ALONG
WITH IFR CEILINGS/VSBY DURING THESE TIME PERIODS. FOR THE
REMAINDER OF THE FORECAST PERIOD...THE BOUNDARY IS EXPECTING TO
STALL ACROSS SE TX THRU C LA...YIELDING SHRA WITH INTERMITTENT
TSRA DURING THIS TIME.
DML
PREV DISCUSSION... /ISSUED 448 PM CDT SUN APR 15 2012/
SYNOPSIS...
WATER VAPOR AND UPPER AIR ANALYSIS SHOWS DEEP TROF LIFTING INTO
THE CNTL PLAINS. A SFC COLD FRONT ASSOCIATED WITH THIS SYSTEM
EXTENDED FM THE CNTL CONUS SOUTHWARD INTO TX...ALONG ROUGHLY A
PARIS TO GONZALES LINE. DIVERGENCE ALOFT IN CONJUNCTION WITH LOW
LEVEL FORCING ASSOCIATED WITH THE FRONT ARE PRODUCING AN
EXTENSIVE BAND OF SHOWERS AND THUNDERSTORMS FROM THE MID MS VALLEY
SOUTH INTO SE TX. RECENT RADAR TRENDS INDICATE SCT SHOWERS
DEVELOPING IN THE WARM MOIST AIRMASS ACRS SE TX INTO SW LA AHEAD
OF THIS LINE.
DISCUSSION...
THIS POTENT SYSTEM WILL CONTINUE TO MOVE EAST TONIGHT...BRINGING
THE COLD FRONT TO THE SABINE RIVER VALLEY BY EARLY MONDAY MORNING.
THERE IS STILL A SLIGHT RISK FOR SEVERE WEATHER ACRS SE TX INTO
WRN LA THIS EVENING...WITH AFTN HEATING CONTRIBUTING TO THE
DESTABILIZATION OF THE ATMOSPHERE. THE POTENTIAL FOR STRONG TO
SEVERE THUNDERSTORMS WILL SHIFT INTO CNTL AND SW LA AFTER
MIDNIGHT TONIGHT AS ADEQUATE DEEP LAYER SHEAR REMAINS IN PLACE
WITH INSTABILITY BECOMING MARGINAL. THE GREATEST THREAT WILL BE
DUE TO DAMAGING WINDS...ALTHOUGH HAIL AND ISOLATED TORNADOES
CANNOT BE RULED OUT ENTIRELY.
THE BIGGER CONCERN HOWEVER REMAINS THE POTENTIAL FOR HEAVY
RAINFALL TONIGHT INTO MONDAY. ABUNDANT MOISTURE OVER THE AREA WITH
PW VALUES APPROACHING 1.7 INCHES ON MONDAY WILL RESULT IN
EFFICIENT RAIN RATES IN SOME STORMS. THE SFC FRONT IS EXPECTED TO
STALL NR THE COAST OR OVER THE NRN GULF ON MONDAY...WITH AN
INVERTED TROF DEVELOPING ALONG IT MONDAY NIGHT. THIS WILL SERVE AS
A FOCUS FOR ADDITIONAL RAINFALL DEVELOPMENT MONDAY AFTN INTO
MONDAY NIGHT. AREAL RAINFALL TOTALS FROM TONIGHT THROUGH TUESDAY
WILL RANGE BETWEEN 2-4 INCHES...ALTHOUGH LOCALIZED HIGHER AMOUNTS
WILL BE POSSIBLE. AT THIS TIME...DO NOT SEE PRECIP TOTALS
EXCEEDING FLASH FLOOD GUIDANCE DURING THE PERIOD...ALTHOUGH
ISOLATED AREAS COULD APPROACH THESE VALUES SHOULD TRAINING STORMS
DEVELOP OVER THE AREA.
THE SFC LOW/FRONT WILL FINALLY SLIDE EAST TUESDAY AS THE UPPER
TROF AXIS CROSSES THE LOWER MS VALLEY. THIS WILL BRING DRIER AIR
INTO THE AREA. MORNING LOWS WILL BE MORE SEASONABLE WHILE AFTN HIGHS
WILL CLIMB INTO THE LOWER 80S. ANOTHER SYSTEM IS FCST TO MOVE
THROUGH THE AREA FRIDAY INTO SATURDAY...BRINGING ANOTHER CHANCE
FOR RAIN AND SLIGHTLY COOLER TEMPERATURES BY NEXT WEEKEND.
MARINE...
THE COMBINATION OF PERSISTENT HIGH PRESSURE TO OUR EAST AND
DEEPENING LOW PRESSURE OVER THE PLAINS STATES WILL KEEP A
STRONG ONSHORE FLOW OVER THE COASTAL WATERS. SMALL CRAFT ADVISORY
CONDITIONS WILL PERSIST OVER THE COASTAL WATERS THROUGH EARLY
MONDAY. SOUTHERLY WINDS WILL DIMINISH MONDAY MORNING AS A COLD
FRONT ADVANCES TOWARD THE REGION...WITH THE BOUNDARY ADVANCING
INTO THE WESTERN GULF MONDAY THEN BRIEFLY SLOWING OR STALLING.
NUMEROUS SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THE FRONT FOR
THE BEGINNING OF THE WORK-WEEK. THE FRONT WILL FINALLY EXIT EAST
ON TUESDAY WITH OFFSHORE FLOW EXPECTED TUESDAY INTO WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 72 79 64 79 59 / 50 80 60 30 10
KBPT 71 79 66 80 61 / 60 80 50 30 10
KAEX 68 79 62 79 57 / 50 60 50 30 10
KLFT 72 82 65 79 60 / 30 70 60 50 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 PM CDT MONDAY FOR THE FOLLOWING
ZONES: WATERS FROM INTRACOASTAL CITY TO CAMERON LA FROM 20
TO 60 NM...WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM 20
TO 60 NM...WATERS FROM LOWER ATCHAFALAYA RIVER TO
INTRACOASTAL CITY LA FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 1 AM CDT MONDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT
20 NM...COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA
OUT 20 NM...COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO
INTRACOASTAL CITY LA OUT 20 NM.
SMALL CRAFT EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH
ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY
TO CAMERON LA OUT 20 NM...COASTAL WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
359 AM EDT MON APR 16 2012
.SYNOPSIS...
HIGH PRESSURE IS OFF THE SOUTHEAST COAST. A WEAKENING COLD FRONT
WILL APPROACH THE MID ATLANTIC TODAY...CROSSING THE REGION TONIGHT...AND
STALLING OVER THE CAROLINAS THROUGH MIDWEEK. AN UPPER DISTURBANCE WILL
MOVE THROUGH THE REGION TUESDAY NIGHT AND WEDNESDAY. HIGH
PRESSURE INFLUENCES THE MID-ATLANTIC STATES DURING THE SECOND HALF
OF THE WORK WEEK. LOW PRESSURE IS EXPECTED TO IMPACT THE REGION
THIS WEEKEND.
&&
.NEAR TERM /TODAY/...
VERY SUMMER-LIKE WX IS ON TAP FOR THE AREA TDA. 03Z SFC ANLYS
SHOWED A 1024 MB HIGH OFF THE SC CST...990 MB LOW PRES OVR SRN MN
W/ A WARM FNT XTNDG INTO ERN ONTARIO AND A COLD FNT W OF THE MS
RVR. THIS COMBINATION WL MEAN THAT THE MID ATLC WL XPRNC SSWRLY
FLOW TDA. GIVEN THE FACT THAT ALMOST THE ENTIRE AREA REACHED THE
M80S ON SUN (DMH AT 88 WAS THE HIGH POINT W/ HGR AT 79 THE LOW)
XPCT A NEAR REPEAT TDA. IR STLT DOES SHOW SOME CLD CVR OVR THE MID
ATLC...BUT THIS IS HIGH AND THIN AND SHOULDN`T DO MUCH TO SURPESS
HTG. HIGH TEMPS AGN GNRLY IN THE M80S.
&&
.SHORT TERM /TONIGHT/...
LN OF CNVCTN IN ASSO W/ THE CD FNT IS RATHER UNIFORM ATTM...AND
BOTH SREF AND HRRR SHOW CVRG IN THE LN WL BE WEAKENING AS IT
PROGRESSES TO THE E. AND THEN THERE IS THE ADAGE "WHEN IN DROUGHT
LV IT OUT." AREA IS CURRENTLY CLASSIFIED IN A D0/D1 DROUGHT. YES
THE RULE MAY BE SIMPLISTIC BUT IT IS SOMETHING TO CONSIDER...AND
IN SOME CASES IT APPLIES. WE ARE CARRYING CHC RW/TRW IN THE FAR
WRN SXNS THIS EVE...BUT IT IS DOUBTFUL THAT PCPN WL REACH FURTHER
E. A WIND SHIFT IS XPCTD LATE TNGT AS THE WEAKENING FNT CROSSES
THE RGN..W/ TEMPS SHOWING A LTL MORE DOWNWARD MVMNT LATE...BUT
GIVEN THE WARMTH OF THE PRVS TWO DAYS WL KEEP FCSTD MINS ABV GDNC
RANGING FM THE M40S IN THE HIGHLANDS TO THE LM60S I-95 AND E.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
THE COLD FRONT WILL MOVE AWAY FROM THE EAST COAST TUE MRNG. IN WAKE
OF THE COLD FRONT...BREEZY W-NW FLOW WILL ADVECT COOLER AND DRIER
AIR INTO THE MID-ATLANTIC STATES AS HIPRES BUILDS IN FROM THE GREAT
LAKES AND OH VLY. WARMING FROM DOWNSLOPING FLOW AND SUNSHINE WILL
OFFSET CAA TO SOME DEGREE EAST OF THE BLUE RIDGE. MAX TEMPS TUE WILL
RANGE FROM AROUND 60F ALONG THE ALLEGHENY FRONT TO MID 70S ALONG AND
EAST OF I-95.
SRN-STREAM SHORTWAVE TROUGH WILL TRACK FROM THE SRN/CENTRAL MS VLY
TO THE MID-ATLANTIC STATES TUE NGT AND WED. SLY FLOW OUT AHEAD OF
THE TROUGH WILL PROMOTE ISENTROPIC LIFT ALONG A FRONTAL BOUNDARY
THAT PUSHES NWD INTO SRN VA ON WED. WITH THE FRONTAL BOUNDARY
EXPECTED TO REMAIN SOUTH OF THE CWA...WEAKENING ULVL JET DYNAMICS
AND A DRY BOUNDARY LAYER IN PLACE...HAVE TRENDED TOWARD A DRIER
SOLUTION THAN THE PREV FCST. ANY SHOWERS WED WILL BE LGT AND MAINLY
FROM CENTRAL VA/SRN MD-SWD.
THE UPPER SHORTWAVE TROUGH WILL MOVE OFF THE MID-ATLANTIC COAST WED
NGT. SFC HIPRES/ZONAL FLOW DOMINATES THE AREA THU. FLOW BECOMES MORE
SLY FRI AS HIPRES SHIFTS OFF THE COAST AND AN UPPER TROUGH AMPLIFIES
OVER THE MIDWEST. ALTHOUGH AN ISO SHOWER CANNOT BE RULED OUT WEST OF
THE BLUE RIDGE FRI AS SLY FLOW DRAWS MOISTURE NWD OUT AHEAD OF THE
NEXT STORM SYSTEM...MAINLY DRY CONDITIONS IN STORE FOR THE SECOND
HALF OF THE WORK WEEK.
COMPLEX WX PATTERN THIS WEEKEND AS THE UPPER TROUGH AMPLIFIES
OVER THE ERN CONUS IN RESPONSE TO A STRONG DISTURBANCE THAT DIGS ON
THE BACKSIDE OF THE TROUGH. CHANCES FOR SHOWERS AND STORMS INCREASE
SAT AS A DEEP MOISTURE CONNECTION FROM THE GULF OF MEXICO TO THE
MID-ATLANTIC REGION EXISTS AHEAD OF A COLD FRONT. MOST EXTENDED-
RANGE GUIDANCE FCST THE DEVELOPMENT OF A CLOSED LOW ALONG THE ERN
SEABOARD LATE IN THE WEEKEND. THERE IS A LOT OF UNCERTAINTY
REGARDING THE DEVELOPMENT OF A COASTAL LOW AND ITS POTENTIAL IMPACTS
TO THE REGION. EYES WILL BE ON THIS SYSTEM AS IT MAY BRING A NEEDED
CHANCE FOR RAIN.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
VFR CONDS FCSTD AT ALL AIRPORT SITES TDA/TNGT.
BREEZY W-NW FLOW BEHIND A COLD FRONT TUE. A PROLONGED PERIOD OF VFR
CONDITIONS EXPECTED TUE-FRI. ONLY WRINKLE IN A DRY FCST WILL BE A
CHANCE OF SHOWERS WED AT CHO.
&&
.MARINE...
THE COMBO OF HIGH PRES OFFSHORE/CD FNT IN THE MS VLLY AND SRLY
CHANNELING HV CAUSED WIND GUSTS ARND 20 KT OVRNGT ON THEBAY. THIS
IS XPCTD TO CONT THIS MRNG/TNGT...AND ACROSS ALL THE WATERS DURG
MONDAY. SCA IN EFFECT FOR THESE AREAS. A WK FNT WL PUSH INTO THE
WATERS LATE TNGT. NO PCPN IS XPCTD W/ IT.
SCA HAS BEEN EXTENDED INTO TUE MRNG FOR THE CHSPK BAY SOUTH OF
POOLES ISLAND AND THE LOWER TIDAL POTOMAC RVR AS NW FLOW BEHIND A
COLD FRONT GUSTS TO 20 KT. SCA MAY NEED TO BE EXTENDED INTO TUE
AFTN...BUT CONFIDENCE WAS NOT HIGH ENOUGH TO DO SO ATTM. WINDS ARE
EXPECTED TO REMAIN BELOW SCA LVLS TUE NGT THRU THE REST OF THE WORK
WEEK.
&&
.FIRE WEATHER...
2 MAJOR FIRES PERSIST IN OUR CWA - "WOLF GAP" ALONG THE BORDER OF
HARDY AND SHENANDOAH COUNTIES..AND "SHIPWRECK" S OF MASSANUTTEN MTN.
MOISTURE LVLS HV CREPT UP...AND MID AFTN RH WL BE IN THE MU30S W
OF THE BLUE RDG. THIS IS ABV THE RH VALUES NEEDED FOR
CONSIDERATION OF A RED FLAG WRNG. WINDS OF 20-25 MPH PSBL LATE
THIS MRNG AND AFTN. 10 HR FUEL MOISTURES ARE ON THE CUSP OF RED
FLAG CONSIDERATION. AM NOT PLANNING TO ISSUE ANY TYPE OF SPL
PRODUCT - WL LV IT FOR THE DAYSHIFT TO CONTACT STATE FIRE MGRS AND
LET THEM TAKE IT FM THERE.
&&
.COMMUNICATION...
NWR XTMR WNG-736 IS CURRENTLY OFF THE AIR. TELCO HAS BEEN NOTIFIED.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TUESDAY FOR ANZ531>534-537-
539>541-543.
SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 8 PM EDT THIS
EVENING FOR ANZ530-535-536-538-542.
&&
$$
PRODUCTS...WOODY!/JRK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
210 PM EDT MON APR 16 2012
.SYNOPSIS...
ISSUED AT 556 AM EDT MON APR 16 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW POTENT SHRTWV/H5
CLOSED LO LIFTING NEWD INTO MN ON NW FLANK OF SHARP RDG OVER THE SE
CONUS...WITH OCCLUDED SFC LO NOT FAR FM MPX AT 03Z. WARM FNT
EXTENDING E FM THIS FEATURE CROSSES NRN WI TO JUST S OF MNM AND
SEPARATES SFC T/TD ARND 70/60 FM T/TD IN THE 40S AND 50S OVER UPR
MI. SLOW WARMING HAS GRADUALLY ERODED SOME LOCALLY DENSE FOG THAT
WAS PRESENT EARLIER OVER THE CWA. DRY SLOTTING ALF E OF THE SHRTWV
HAS INVADED THE CWA/MUCH OF WI...WITH SOME SHRA/TS OVER LK SUP JUST
N OF THE H85 WARM FNT WHERE H7-6 FGEN IS SHARPEST. SOME ISOLD SHRA
ARE LOCATED OVER WI S OF THE WARM FNT. HEAVIER/MORE WIDESPREAD
SHRA/TS ARE PRESENT OVER ERN WI/LK MI WITHIN THE WARM CONVEYOR BELT
MSTR TO THE E OF THE DRY SLOT THAT WL ALSO MISS UPR MI TO THE E. TO
THE NW...WELL DEFINED CCB IS PRESENT FM NRN MN EXTENDING INTO THE
ERN DAKOTAS ON THE CYC SIDE OF H5 LO TRACK. A BAND OF SHRA/SOME TS
IS PRESENT EXTENDING FM NW WI TO FAR SE MN ON THE WRN EDGE OF DRY
SLOT/IN ADVANCE OF APRCHG UPR LO...WHERE SPC MESOANALYSIS INDICATES
MUCAPE ARND 500 J/KG TO THE S OF SFC WARM FNT. DESPITE SOME SHARP
H7-3 QVECTOR CNVGC/DIFFLUENT UPR FLOW IN EXIT REGION OF SUPPORTING
120KT H3 JET MAX/HGT FALLS AHEAD OF THIS FEATURE/SFC-6KM BULK SHEAR
UP TO 70 KTS...THE TS HAVE NOT INTENSIFIED AS THE LINE OF SHRA MOVES
E INTO WI EVEN THOUGH THERE HAVE BEEN SOME WIND GUSTS UP TO 40 KTS
OBSVD WHERE THE CONVECTION IS SFC BASED IN THE WARM SECTOR. MODERATE
RA IS FALLING IN THE COLDER AIR OVER MUCH OF NRN MN UNDER THE
SHARPLY NNE CYC FLOW TO THE N AND NW OF THE SFC LO...WITH N WIND
GUSTS 30-40 KTS. SN HAS MIXED IN WITH THE PCPN OVER NRN MN AS THESE
STRONG WINDS HAVE DRAWN COLDER AIR TO THE S. THE 00Z H85 WIND AT
ABERDEEN SDAKOTA WAS 75 KTS. 02Z NE WIND GUSTS DOWN THE W END OF LK
SUP REACHED 44 MPH AT ASX IN NW WI. NO SN IS FALLING UNDER THIS AREA
AS OF MIDNGT...BUT MUCH COLDER AIR LURKS JUST TO THE N...WITH 00Z
H85 TEMP -11C AT YPL.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 556 AM EDT MON APR 16 2012
MAIN FCST CONCERNS FOR TODAY INTO TNGT ARE POPS/PTYPE/POTENTIAL FOR
STRONG WINDS ASSOCIATED WITH CCB THAT WL SHIFT ACRS UPR MI AS THE
SHRTWV/SFC LO MOVES TO THE E.
TODAY...SFC LO IS PROGGED TO MOVE TO SE LK SUP/ERN UPR MI BY 18Z
BEFORE CONTINUING INTO QUEBEC BY 00Z. SINCE THE SHRTWV WL BE MOVING
INTO A ZONE OF UPR CONFLUENCE BTWN THE BASE OF UPR TROF CENTERED
NEAR HUDSON BAY AND UPR RDG IN THE SE CONUS...THE SHRTWV/SFC LO ARE
EXPECTED TO WEAKEN...ESPECIALLY THIS AFTN. EVEN SO...TIGHT PRES
GRADIENT/SHARP NLY FLOW ON THE WRN FLANK OF THE DEPARTING LO ARE
FCST TO ADVECT MUCH COLDER AIR LURKING TO THE N INTO THE UPR LKS.
EXPECT INCRSG POPS OVER THE W BY SUNRISE TO SPREAD EWD WITH THE
DEEPER MSTR UNDER THE CCB. FCST SDNGS STILL SHOW SOME SHARP COOLING
BLO ELEVATED WARM LYR...SO WL RETAIN MENTION OF SLEET IN THE
TRANSITION BTWN ALL RA AND MORE SN ONCE DEEPER COLD AIR ARRIVES OVER
THE W BY AFTN. BUT STRONG CAD/WEAKENING UPR DVGC AS JET CORE SHIFTS
TO THE NE WL TEND TO CAUSE THE CCB TO DECAY A BIT AS LARGER SCALE
QVECTOR DVGC DVLPS OVER THE CCB. ALTHOUGH FCST H85 TEMPS FALLING AS
LO AS -13C TO -15C BY 00Z COULD ADD SOME LK ENHANCED COMPONENT INTO
THE PCPN FIELD...WEAKENING DYNAMICS SHOULD LIMIT THIS POTENTIAL WITH
THE COLDEST AIR ARRIVING ONLY AFT 18Z ONCE LARGER SCALE QVECTOR DVGC
DOMINATED BY THE CAD IS IN PLACE. SO EXPECT SN ACCUMS TO BE SUB
ADVY. THE ARRIVAL OF THE COLDER AIR WL SHARPEN LLVL INSTABILITY AND
AID MIXING OF H925 WINDS UP TO 35 TO 45 KTS. ALTHOUGH THE APRCH FM
THE WSW OF THE SHARP PRES RISE CENTER WL RESULT IN ISALLOBARIC WIND
COMPONENT AT A RIGHT ANGLE OR EVEN OPPOSING THE GRADIENT FLOW AND
THE LO WL BE WEAKENING WITH TIME... THE MAGNITUDE OF THE GRADIENT
WIND IN CONCERT WITH FAVORABLE MIXING UNDER THE INCOMING THERMAL
TROF JUSTIFY ISSUANCE OF HI WIND ADVYS FOR EXPOSED LOCATIONS NEAR
THE LK SUP SHORE.
TNGT...AS HI PRES BLDS INTO THE WRN CWA OVERNGT...THE PRES GRADIENT
WL DIMINISH QUICKLY FOLLOWING PASSAGE OF PRES RISE CENTER TO THE E
AFT 00Z. SO EXPECT GUSTY WINDS TO DIMINISH QUICKLY THIS EVNG INTO
THE OVERNGT. BUMPED POPS UP TO LIKELY IN AREAS E OF MQT WITH H85
THERMAL TROF/TEMPS AS LO AS -13C TO -15C CONDUCIVE FOR SOME LES IN
MOIST CYC NW FLOW. SUBSIDENCE DROPPING INVRN AOB 3K FT/RISING H85
TEMPS/WEAKENING CYC FLOW OVERNGT WL CAUSE ANY SHSN TO DIMINISH
STEADILY AFT MIDNGT. CONSIDERING THE CHILL OF THE INCOMING
AIRMASS...PWAT FALLING BLO 0.25 INCH...AND THE PROSPECT OF CLRG OVER
THE INTERIOR W AS HI PRES BLDS OVHD...TENDED TO GO LOWER THAN
PREVIOUS FCST FOR MIN TEMPS IN THAT AREA.
TUE...HUDSON BAY HI PRES/DRY AIRMASS WL DOMINATE UPR MI...BRINGING
RELATIVELY DRY AND TRANQUIL WX. ALTHOUGH THERE WL BE SOME LINGERING
SC OVER MAINLY THE E HALF IN THE MRNG WITH LINGERING LIGHTER CYC
FLOW/LLVL MSTR/THERMAL TROF UNDER SUBSIDENCE INVRN...THIS CLD SHOULD
DISSOLVE BY AFTN WITH ARRIVAL OF SFC HI PRES RDG/ACYC FLOW AND
DAYTIME HEATING...GIVING WAY TO JUST SOME DIURNAL CU. MIXING TO H85
ON GFS FCST SDNGS WOULD YIELD HI TEMPS RANGING FM ARND 40 AT ERY TO
50 NEAR THE WI BORDER...BUT THE DAY WL BE COOLER NEAR THE MODIFYING
INFLUENCE OF THE LKS AS WEAK PRES GRADIENT IN THE AFTN WL ALLOW FOR
LK BREEZE DEVELOPMENT.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 556 AM EDT MON APR 16 2012
MUCH OF LONGER RANGE PORTION OF FCST IS DOMINATED BY NEGATIVE UPPER
AIR ANAMOLIES STATIONED OVER NORTHEAST PACIFIC OCEAN/GULF OF ALASKA
AND OVR HUDSON BAY INTO NUNAVUT CANADA. ZONAL FLOW FCST TO IMPACT
CONUS MUCH OF THE WEEK AND INTO NEXT WEEKEND AS WELL.
ATTM ONLY ONE SYSTEM IS SURE THING TO IMPACT THE AREA IN THE LONGER
TERM. THIS IS STILL OPEN TO CHANGE DEPENDING ON TRACK OF LATE WEEK
SYSTEM.
SHORTWAVE ON SOUTHERN EDGE OF TROUGH OVR NORTHEAST PACIFIC/GULF OF
ALASKA FCST TO SLIDE ACROSS ROCKIES INTO NORTHERN PLAINS ON TUESDAY
NIGHT AND PUSH ACROSS UPPER GREAT LAKES ON WEDNESDAY. SW WINDS AHEAD
OF SFC-H85 TROUGH BRINGS MUCH WARMER/MOIST AIR INTO UPR LAKES IN WAKE
OF THE EARLY WEEK CHILL. JET STREAKS SLIDING ACROSS THE NORTHERN
PLAINS AND OVR ONTARIO SHOULD HELP SYSTEM STAY FAIRLY ORGANIZED AS
IT CROSSES CWA ON WEDNESDAY. APPEARS THAT SYSTEM WILL BE COMPACT AS
IT MOVES THROUGH...LEADING TO A FAIRLY STRONG WIND FIELD IN THE
VCNTY. HAVE INCREASED WINDS ESPECIALLY IN THE WAKE OF THE LOW LATE
WEDNESDAY INTO WEDNESDAY NIGHT NEAR LAKE SUPERIOR.
PTYPE MAY BE ISSUE INITIALLY WITH SNOW OR EVEN FREEZING RAIN
POSSIBLE INTERIOR CNTRL /10Z-12Z ON WEDNESDAY/ AS SWATH OF
PRECIPITATION ARRIVES OVER PERSISTENT SHALLOW COLD AIR. ANY WINTRY
PRECIP SHOULD BE BRIEF THOUGH AS STRONG WARM AIR ADVECTION SFC-H85
QUICKLY BECOMES DOMINANT. ADDED TSRA FOR WEDNESDAY AS WELL DUE TO
STEEP H7-H5 LAPSE RATES AOA 8C/KM. PRETTY DYNAMIC SYSTEM LOOKS TO
AFFECT THE AREA. GIVEN CONVECTIVE POTENTIAL MAY SEE RAIN TOTALS OVR
0.25 INCH IN SOME AREAS. STILL SOME POTENTIAL FOR SNOW AS SYSTEM
EXITS ON WEDNESDAY NIGHT. 850MB/925MB TEMPS AS LOW AS -10C/-6C STILL
LEAVES POTENTIAL FOR BRIEF LAKE ENHANCED SNOW OVR HIGHER TERRAIN OF
WEST CWA IF ENOUGH MOISTURE REMAINS IN PLACE. JUST LOW CHANCE POPS
FOR NOW.
IN THE EXTENDED...FRIDAY SYSTEM IS BACK ON FOR AT LEAST THE
SOUTHEAST QUARTER OF THE CWA...AT LEAST ACCORDING TO ECMWF AND
CANADIAN. ECMWF HAS SHOWN THIS OFF AND ON FOR LAST FEW DAYS AND
LATEST GFS HAS TRENDED NORTH...THOUGH IS STILL MAINLY SOUTH OF CWA
WITH ITS AXIS OF MAX QPF. SINCE SFC LOW IS STILL FCST TO PASS MAINLY
OVR CNTRL GREAT LAKES EVEN ON THE ECMWF...PCPN IF IT OCCURS WOULD
LIKELY STAY MAINLY IN FORM OF SNOW. ECMWF WOULD POINT TO SEVERAL
INCHES OF ACCUMULATION OVR SE CWA JUST NORTH OF H85-H7 LOW TRACK.
SYSTEM IS STILL NEAR THE ALLUTIANS IN THE PACIFIC SO EXPECT MORE
JUMPING AROUND ON THE POSITION OF THE LOW YET THIS WEEK. SOMETHING
TO DEFINITELY KEEP AN EYE ON THOUGH.
BEYOND FRIDAY APPEARS DRY WEATHER IS IN STORE FOR NEXT WEEKEND. WILL
NOT BE ESPECIALLY WARM THOUGH AS LARGER SCALE TROUGH RESIDES OVR
MUCH OF EASTERN CANADA AND EASTERN CONUS. SFC-H85 RIDGE WILL BE
OVERHEAD LEADING TO LIGHT WINDS/LK BREEZES. BEST CHANCE FOR DAYTIME
TEMPS AT LEAST NEAR NORMAL WILL BE WELL INLAND FM THE LAKES TOWARD
WISCONSIN BORDER. COULD ALSO BE CHILLY NIGHTS AS WELL...WITH TEMPS
POSSIBLY IN THE TEENS AND 20S. EXPECT RELATIVE HUMIDITIES TO BE ON
THE LOW SIDE FOR THE WEEKEND AS WELL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 209 PM EDT MON APR 16 2012
FROZEN PRECIPITATION IS NOW FALLING AT ALL THREE SITES AS COLD AIR
SURGES INTO THE AREA BEHIND A DEPARTING LOW PRESSURE. EXPECT -PLSN
AT SAW TO TRANSITION COMPLETELY TO -SN BY 19Z. OTHERWISE...BACK END
OF THE MAIN -SN SHIELD WILL PASS THROUGH IWD AND CMX THIS AFTERNOON
TO GIVE WAY TO -SHSN AND ALLOW BOTH SITES TO IMPROVE TO IFR
CONDITIONS. NOT TOO CONCERNED WITH VIS AS UPSTREAM AIR IS RELATIVELY
DRY...THOUGH THE HEAVIEST SNOW SHOWERS COULD TEMPORARILY DROP VIS
BELOW 1SM. STRONG WINDS QUICKLY SUBSIDE FROM WEST TO EAST THIS
EVENING AS A WEAK RIDGE BUILDS OVER LAKE SUPERIOR LATE TONIGHT.
EXPECT IFR CIGS TO HOLD THROUGHOUT THE NIGHT AS LAKE MODIFIED AIR
KEEPS A LITTLE MOISTURE AROUND...EXPECT AT IWD WHERE SOME DRYING
COULD TAKE PLACE LATE TONIGHT AND SCATTER OUT THE CLOUDS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 556 AM EDT MON APR 16 2012
CONSIDERING A NUMBER OF OBS SHOWING WIND GUSTS UP TO 50 KTS OVER THE
W HALF WHERE TERRAIN ENHANCES THE PREVAILING NE FLOW EARLY THIS
MRNG...OPTED TO ISSUE STORM WARNINGS FOR THE 3 WESTERN ZONES OF LAKE
SUPERIOR. AS THE FLOW BACKS TO N...EXPECT THE WINDS TO SUBSIDE A BIT
WITH JUST N GALES THRU THE AFTN AS THE ARRIVAL OF MUCH COLDER
ENHANCES MIXING OF HIER MOMENTUM TO THE LAKE SURFACE. EVEN THESE
WINDS WILL TEND TO DIMINISH OVER THE FAR W LATER IN THE DAY WITH
APPROACH OF HI PRES RIDGE. LINGERING GALES WILL END OVER THE REST OF
THE LAKE AS THE HI PRES RIDGE/WEAKER PRES GRADIENT DOMINATES THE
LAKE.
NEXT LOW PRES SYSTEM FCST TO MOVE THRU THE UPPER LAKES WED IS NOW
LOOKING STRONGER. EXPECT SOUTHERLY WINDS TO 30 KTS WEDNESDAY MORNING
TO SHIFT TO THE WEST AND INCREASE TO GALES ESPECIALLY OVER THE EAST
HALF OF THE LAKE BY LATER WEDNESDAY AFTN AND INTO THE EARLY EVENING.
WINDS DIMINISH BLO 25 KTS LATER WEDNESDAY NIGHT INTO THURSDAY AS
HIGH PRESSURE MOVES BACK OVR THE UPR LAKES REGION. SFC LOW PASSING
BY ACROSS THE CNTRL GREAT LAKES THURSDAY NIGHT INTO FRIDAY COULD
RESULT IN NORTHEAST WINDS 25-30 KTS OVR SOUTHERN PORTIONS OF LK
SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR MIZ002-003.
WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ001-005.
WIND ADVISORY UNTIL 11 PM EDT THIS EVENING FOR MIZ006-007.
LAKE SUPERIOR...
GALE WARNING UNTIL 2 AM EDT TUESDAY FOR LSZ251-267.
GALE WARNING UNTIL 2 AM EDT TUESDAY FOR LSZ249-250-266.
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LSZ242>245-248-
263>265.
LAKE MICHIGAN...
GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LMZ221-248-250.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
AVIATION...TK
MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
751 AM EDT MON APR 16 2012
.SYNOPSIS...
ISSUED AT 556 AM EDT MON APR 16 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW POTENT SHRTWV/H5
CLOSED LO LIFTING NEWD INTO MN ON NW FLANK OF SHARP RDG OVER THE SE
CONUS...WITH OCCLUDED SFC LO NOT FAR FM MPX AT 03Z. WARM FNT
EXTENDING E FM THIS FEATURE CROSSES NRN WI TO JUST S OF MNM AND
SEPARATES SFC T/TD ARND 70/60 FM T/TD IN THE 40S AND 50S OVER UPR
MI. SLOW WARMING HAS GRADUALLY ERODED SOME LOCALLY DENSE FOG THAT
WAS PRESENT EARLIER OVER THE CWA. DRY SLOTTING ALF E OF THE SHRTWV
HAS INVADED THE CWA/MUCH OF WI...WITH SOME SHRA/TS OVER LK SUP JUST
N OF THE H85 WARM FNT WHERE H7-6 FGEN IS SHARPEST. SOME ISOLD SHRA
ARE LOCATED OVER WI S OF THE WARM FNT. HEAVIER/MORE WIDESPREAD
SHRA/TS ARE PRESENT OVER ERN WI/LK MI WITHIN THE WARM CONVEYOR BELT
MSTR TO THE E OF THE DRY SLOT THAT WL ALSO MISS UPR MI TO THE E. TO
THE NW...WELL DEFINED CCB IS PRESENT FM NRN MN EXTENDING INTO THE
ERN DAKOTAS ON THE CYC SIDE OF H5 LO TRACK. A BAND OF SHRA/SOME TS
IS PRESENT EXTENDING FM NW WI TO FAR SE MN ON THE WRN EDGE OF DRY
SLOT/IN ADVANCE OF APRCHG UPR LO...WHERE SPC MESOANALYSIS INDICATES
MUCAPE ARND 500 J/KG TO THE S OF SFC WARM FNT. DESPITE SOME SHARP
H7-3 QVECTOR CNVGC/DIFFLUENT UPR FLOW IN EXIT REGION OF SUPPORTING
120KT H3 JET MAX/HGT FALLS AHEAD OF THIS FEATURE/SFC-6KM BULK SHEAR
UP TO 70 KTS...THE TS HAVE NOT INTENSIFIED AS THE LINE OF SHRA MOVES
E INTO WI EVEN THOUGH THERE HAVE BEEN SOME WIND GUSTS UP TO 40 KTS
OBSVD WHERE THE CONVECTION IS SFC BASED IN THE WARM SECTOR. MODERATE
RA IS FALLING IN THE COLDER AIR OVER MUCH OF NRN MN UNDER THE
SHARPLY NNE CYC FLOW TO THE N AND NW OF THE SFC LO...WITH N WIND
GUSTS 30-40 KTS. SN HAS MIXED IN WITH THE PCPN OVER NRN MN AS THESE
STRONG WINDS HAVE DRAWN COLDER AIR TO THE S. THE 00Z H85 WIND AT
ABERDEEN SDAKOTA WAS 75 KTS. 02Z NE WIND GUSTS DOWN THE W END OF LK
SUP REACHED 44 MPH AT ASX IN NW WI. NO SN IS FALLING UNDER THIS AREA
AS OF MIDNGT...BUT MUCH COLDER AIR LURKS JUST TO THE N...WITH 00Z
H85 TEMP -11C AT YPL.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 556 AM EDT MON APR 16 2012
MAIN FCST CONCERNS FOR TODAY INTO TNGT ARE POPS/PTYPE/POTENTIAL FOR
STRONG WINDS ASSOCIATED WITH CCB THAT WL SHIFT ACRS UPR MI AS THE
SHRTWV/SFC LO MOVES TO THE E.
TODAY...SFC LO IS PROGGED TO MOVE TO SE LK SUP/ERN UPR MI BY 18Z
BEFORE CONTINUING INTO QUEBEC BY 00Z. SINCE THE SHRTWV WL BE MOVING
INTO A ZONE OF UPR CONFLUENCE BTWN THE BASE OF UPR TROF CENTERED
NEAR HUDSON BAY AND UPR RDG IN THE SE CONUS...THE SHRTWV/SFC LO ARE
EXPECTED TO WEAKEN...ESPECIALLY THIS AFTN. EVEN SO...TIGHT PRES
GRADIENT/SHARP NLY FLOW ON THE WRN FLANK OF THE DEPARTING LO ARE
FCST TO ADVECT MUCH COLDER AIR LURKING TO THE N INTO THE UPR LKS.
EXPECT INCRSG POPS OVER THE W BY SUNRISE TO SPREAD EWD WITH THE
DEEPER MSTR UNDER THE CCB. FCST SDNGS STILL SHOW SOME SHARP COOLING
BLO ELEVATED WARM LYR...SO WL RETAIN MENTION OF SLEET IN THE
TRANSITION BTWN ALL RA AND MORE SN ONCE DEEPER COLD AIR ARRIVES OVER
THE W BY AFTN. BUT STRONG CAD/WEAKENING UPR DVGC AS JET CORE SHIFTS
TO THE NE WL TEND TO CAUSE THE CCB TO DECAY A BIT AS LARGER SCALE
QVECTOR DVGC DVLPS OVER THE CCB. ALTHOUGH FCST H85 TEMPS FALLING AS
LO AS -13C TO -15C BY 00Z COULD ADD SOME LK ENHANCED COMPONENT INTO
THE PCPN FIELD...WEAKENING DYNAMICS SHOULD LIMIT THIS POTENTIAL WITH
THE COLDEST AIR ARRIVING ONLY AFT 18Z ONCE LARGER SCALE QVECTOR DVGC
DOMINATED BY THE CAD IS IN PLACE. SO EXPECT SN ACCUMS TO BE SUB
ADVY. THE ARRIVAL OF THE COLDER AIR WL SHARPEN LLVL INSTABILITY AND
AID MIXING OF H925 WINDS UP TO 35 TO 45 KTS. ALTHOUGH THE APRCH FM
THE WSW OF THE SHARP PRES RISE CENTER WL RESULT IN ISALLOBARIC WIND
COMPONENT AT A RIGHT ANGLE OR EVEN OPPOSING THE GRADIENT FLOW AND
THE LO WL BE WEAKENING WITH TIME... THE MAGNITUDE OF THE GRADIENT
WIND IN CONCERT WITH FAVORABLE MIXING UNDER THE INCOMING THERMAL
TROF JUSTIFY ISSUANCE OF HI WIND ADVYS FOR EXPOSED LOCATIONS NEAR
THE LK SUP SHORE.
TNGT...AS HI PRES BLDS INTO THE WRN CWA OVERNGT...THE PRES GRADIENT
WL DIMINISH QUICKLY FOLLOWING PASSAGE OF PRES RISE CENTER TO THE E
AFT 00Z. SO EXPECT GUSTY WINDS TO DIMINISH QUICKLY THIS EVNG INTO
THE OVERNGT. BUMPED POPS UP TO LIKELY IN AREAS E OF MQT WITH H85
THERMAL TROF/TEMPS AS LO AS -13C TO -15C CONDUCIVE FOR SOME LES IN
MOIST CYC NW FLOW. SUBSIDENCE DROPPING INVRN AOB 3K FT/RISING H85
TEMPS/WEAKENING CYC FLOW OVERNGT WL CAUSE ANY SHSN TO DIMINISH
STEADILY AFT MIDNGT. CONSIDERING THE CHILL OF THE INCOMING
AIRMASS...PWAT FALLING BLO 0.25 INCH...AND THE PROSPECT OF CLRG OVER
THE INTERIOR W AS HI PRES BLDS OVHD...TENDED TO GO LOWER THAN
PREVIOUS FCST FOR MIN TEMPS IN THAT AREA.
TUE...HUDSON BAY HI PRES/DRY AIRMASS WL DOMINATE UPR MI...BRINGING
RELATIVELY DRY AND TRANQUIL WX. ALTHOUGH THERE WL BE SOME LINGERING
SC OVER MAINLY THE E HALF IN THE MRNG WITH LINGERING LIGHTER CYC
FLOW/LLVL MSTR/THERMAL TROF UNDER SUBSIDENCE INVRN...THIS CLD SHOULD
DISSOLVE BY AFTN WITH ARRIVAL OF SFC HI PRES RDG/ACYC FLOW AND
DAYTIME HEATING...GIVING WAY TO JUST SOME DIURNAL CU. MIXING TO H85
ON GFS FCST SDNGS WOULD YIELD HI TEMPS RANGING FM ARND 40 AT ERY TO
50 NEAR THE WI BORDER...BUT THE DAY WL BE COOLER NEAR THE MODIFYING
INFLUENCE OF THE LKS AS WEAK PRES GRADIENT IN THE AFTN WL ALLOW FOR
LK BREEZE DEVELOPMENT.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 556 AM EDT MON APR 16 2012
MUCH OF LONGER RANGE PORTION OF FCST IS DOMINATED BY NEGATIVE UPPER
AIR ANAMOLIES STATIONED OVER NORTHEAST PACIFIC OCEAN/GULF OF ALASKA
AND OVR HUDSON BAY INTO NUNAVUT CANADA. ZONAL FLOW FCST TO IMPACT
CONUS MUCH OF THE WEEK AND INTO NEXT WEEKEND AS WELL.
ATTM ONLY ONE SYSTEM IS SURE THING TO IMPACT THE AREA IN THE LONGER
TERM. THIS IS STILL OPEN TO CHANGE DEPENDING ON TRACK OF LATE WEEK
SYSTEM.
SHORTWAVE ON SOUTHERN EDGE OF TROUGH OVR NORTHEAST PACIFIC/GULF OF
ALASKA FCST TO SLIDE ACROSS ROCKIES INTO NORTHERN PLAINS ON TUESDAY
NIGHT AND PUSH ACROSS UPPER GREAT LAKES ON WEDNESDAY. SW WINDS AHEAD
OF SFC-H85 TROUGH BRINGS MUCH WARMER/MOIST AIR INTO UPR LAKES IN WAKE
OF THE EARLY WEEK CHILL. JET STREAKS SLIDING ACROSS THE NORTHERN
PLAINS AND OVR ONTARIO SHOULD HELP SYSTEM STAY FAIRLY ORGANIZED AS
IT CROSSES CWA ON WEDNESDAY. APPEARS THAT SYSTEM WILL BE COMPACT AS
IT MOVES THROUGH...LEADING TO A FAIRLY STRONG WIND FIELD IN THE
VCNTY. HAVE INCREASED WINDS ESPECIALLY IN THE WAKE OF THE LOW LATE
WEDNESDAY INTO WEDNESDAY NIGHT NEAR LAKE SUPERIOR.
PTYPE MAY BE ISSUE INITIALLY WITH SNOW OR EVEN FREEZING RAIN
POSSIBLE INTERIOR CNTRL /10Z-12Z ON WEDNESDAY/ AS SWATH OF
PRECIPITATION ARRIVES OVER PERSISTENT SHALLOW COLD AIR. ANY WINTRY
PRECIP SHOULD BE BRIEF THOUGH AS STRONG WARM AIR ADVECTION SFC-H85
QUICKLY BECOMES DOMINANT. ADDED TSRA FOR WEDNESDAY AS WELL DUE TO
STEEP H7-H5 LAPSE RATES AOA 8C/KM. PRETTY DYNAMIC SYSTEM LOOKS TO
AFFECT THE AREA. GIVEN CONVECTIVE POTENTIAL MAY SEE RAIN TOTALS OVR
0.25 INCH IN SOME AREAS. STILL SOME POTENTIAL FOR SNOW AS SYSTEM
EXITS ON WEDNESDAY NIGHT. 850MB/925MB TEMPS AS LOW AS -10C/-6C STILL
LEAVES POTENTIAL FOR BRIEF LAKE ENHANCED SNOW OVR HIGHER TERRAIN OF
WEST CWA IF ENOUGH MOISTURE REMAINS IN PLACE. JUST LOW CHANCE POPS
FOR NOW.
IN THE EXTENDED...FRIDAY SYSTEM IS BACK ON FOR AT LEAST THE
SOUTHEAST QUARTER OF THE CWA...AT LEAST ACCORDING TO ECMWF AND
CANADIAN. ECMWF HAS SHOWN THIS OFF AND ON FOR LAST FEW DAYS AND
LATEST GFS HAS TRENDED NORTH...THOUGH IS STILL MAINLY SOUTH OF CWA
WITH ITS AXIS OF MAX QPF. SINCE SFC LOW IS STILL FCST TO PASS MAINLY
OVR CNTRL GREAT LAKES EVEN ON THE ECMWF...PCPN IF IT OCCURS WOULD
LIKELY STAY MAINLY IN FORM OF SNOW. ECMWF WOULD POINT TO SEVERAL
INCHES OF ACCUMULATION OVR SE CWA JUST NORTH OF H85-H7 LOW TRACK.
SYSTEM IS STILL NEAR THE ALLUTIANS IN THE PACIFIC SO EXPECT MORE
JUMPING AROUND ON THE POSITION OF THE LOW YET THIS WEEK. SOMETHING
TO DEFINITELY KEEP AN EYE ON THOUGH.
BEYOND FRIDAY APPEARS DRY WEATHER IS IN STORE FOR NEXT WEEKEND. WILL
NOT BE ESPECIALLY WARM THOUGH AS LARGER SCALE TROUGH RESIDES OVR
MUCH OF EASTERN CANADA AND EASTERN CONUS. SFC-H85 RIDGE WILL BE
OVERHEAD LEADING TO LIGHT WINDS/LK BREEZES. BEST CHANCE FOR DAYTIME
TEMPS AT LEAST NEAR NORMAL WILL BE WELL INLAND FM THE LAKES TOWARD
WISCONSIN BORDER. COULD ALSO BE CHILLY NIGHTS AS WELL...WITH TEMPS
POSSIBLY IN THE TEENS AND 20S. EXPECT RELATIVE HUMIDITIES TO BE ON
THE LOW SIDE FOR THE WEEKEND AS WELL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 747 AM EDT MON APR 16 2012
COMPLICATED FORECAST OVER THE NEXT 12 HOURS AS LOW PRESSURE SYSTEM
MOVES ACROSS UPPER MICHIGAN AND MUCH COLDER AIR PUSHES INTO THE
REGION.
KIWD AND KCMX...CONDITIONS WILL REMAIN NEAR ALT LANDING MINS THROUGH
EARLY AFTN AS FLOW BCMS ONSHORE AND NERLY. COLD ADVECTION BEHIND
FRONT WILL TURN SHRA TO SN AND PL BY MID MORNING AS NORTH WINDS GUST
FM OVER 30 KTS. EXPECT CONDITIONS TO IMPROVE TO MVFR BY THIS EVENING
AS RIDGE BUILDING IN WILL KNOCK DOWN WINDS AND BRING IN DRIER AIR.
KSAW...EXPECT VFR CIGS AND POSSIBLE MVFR VSBY AS SOME SHRA MOVE
THROUGH THIS MORNING. WINDS WILL SHIFT NW AND BECOME GUSTY AOA 30
KTS BEHIND COLD FRONT BY EARLY AFTN WITH SHRA CHANGING TO SHSN
ALTHOUGH EXPECT GENERALLY MVFR CONDITIONS. RIDGING FM THE WEST
WILL DIMINISH WINDS LATER THIS EVENING AS BRIEF PERIOD OF LAKE
ENHANCED SNOW ENDS. MVFR CLOUDS WILL REMAIN THROUGH OVERNIGHT
HOURS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 556 AM EDT MON APR 16 2012
CONSIDERING A NUMBER OF OBS SHOWING WIND GUSTS UP TO 50 KTS OVER THE
W HALF WHERE TERRAIN ENHANCES THE PREVAILING NE FLOW EARLY THIS
MRNG...OPTED TO ISSUE STORM WARNINGS FOR THE 3 WESTERN ZONES OF LAKE
SUPERIOR. AS THE FLOW BACKS TO N...EXPECT THE WINDS TO SUBSIDE A BIT
WITH JUST N GALES THRU THE AFTN AS THE ARRIVAL OF MUCH COLDER
ENHANCES MIXING OF HIER MOMENTUM TO THE LAKE SURFACE. EVEN THESE
WINDS WILL TEND TO DIMINISH OVER THE FAR W LATER IN THE DAY WITH
APPROACH OF HI PRES RIDGE. LINGERING GALES WILL END OVER THE REST OF
THE LAKE AS THE HI PRES RIDGE/WEAKER PRES GRADIENT DOMINATES THE
LAKE.
NEXT LOW PRES SYSTEM FCST TO MOVE THRU THE UPPER LAKES WED IS NOW
LOOKING STRONGER. EXPECT SOUTHERLY WINDS TO 30 KTS WEDNESDAY MORNING
TO SHIFT TO THE WEST AND INCREASE TO GALES ESPECIALLY OVER THE EAST
HALF OF THE LAKE BY LATER WEDNESDAY AFTN AND INTO THE EARLY EVENING.
WINDS DIMINISH BLO 25 KTS LATER WEDNESDAY NIGHT INTO THURSDAY AS
HIGH PRESSURE MOVES BACK OVR THE UPR LAKES REGION. SFC LOW PASSING
BY ACROSS THE CNTRL GREAT LAKES THURSDAY NIGHT INTO FRIDAY COULD
RESULT IN NORTHEAST WINDS 25-30 KTS OVR SOUTHERN PORTIONS OF LK
SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR MIZ002-003.
WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ001.
WIND ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM EDT THIS EVENING
FOR MIZ006-007.
WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM EDT THIS EVENING
FOR MIZ005.
LAKE SUPERIOR...
GALE WARNING FROM 5 PM THIS AFTERNOON TO 2 AM EDT TUESDAY FOR
LSZ251-267.
GALE WARNING FROM 11 AM THIS MORNING TO 2 AM EDT TUESDAY FOR
LSZ266.
GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR LSZ265.
STORM WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ263-264.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 8 PM EDT THIS EVENING
FOR LSZ248-263-264.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 2 AM EDT TUESDAY FOR
LSZ249-250.
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LSZ242>245.
GALE WARNING UNTIL 2 PM EDT /1 PM CDT/ THIS AFTERNOON FOR LSZ240-
241.
STORM WARNING UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING FOR LSZ162.
GALE WARNING UNTIL 2 PM EDT /1 PM CDT/ THIS AFTERNOON FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
AVIATION...JLA
MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
558 AM EDT MON APR 16 2012
.SYNOPSIS...
ISSUED AT 556 AM EDT MON APR 16 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW POTENT SHRTWV/H5
CLOSED LO LIFTING NEWD INTO MN ON NW FLANK OF SHARP RDG OVER THE SE
CONUS...WITH OCCLUDED SFC LO NOT FAR FM MPX AT 03Z. WARM FNT
EXTENDING E FM THIS FEATURE CROSSES NRN WI TO JUST S OF MNM AND
SEPARATES SFC T/TD ARND 70/60 FM T/TD IN THE 40S AND 50S OVER UPR
MI. SLOW WARMING HAS GRADUALLY ERODED SOME LOCALLY DENSE FOG THAT
WAS PRESENT EARLIER OVER THE CWA. DRY SLOTTING ALF E OF THE SHRTWV
HAS INVADED THE CWA/MUCH OF WI...WITH SOME SHRA/TS OVER LK SUP JUST
N OF THE H85 WARM FNT WHERE H7-6 FGEN IS SHARPEST. SOME ISOLD SHRA
ARE LOCATED OVER WI S OF THE WARM FNT. HEAVIER/MORE WIDESPREAD
SHRA/TS ARE PRESENT OVER ERN WI/LK MI WITHIN THE WARM CONVEYOR BELT
MSTR TO THE E OF THE DRY SLOT THAT WL ALSO MISS UPR MI TO THE E. TO
THE NW...WELL DEFINED CCB IS PRESENT FM NRN MN EXTENDING INTO THE
ERN DAKOTAS ON THE CYC SIDE OF H5 LO TRACK. A BAND OF SHRA/SOME TS
IS PRESENT EXTENDING FM NW WI TO FAR SE MN ON THE WRN EDGE OF DRY
SLOT/IN ADVANCE OF APRCHG UPR LO...WHERE SPC MESOANALYSIS INDICATES
MUCAPE ARND 500 J/KG TO THE S OF SFC WARM FNT. DESPITE SOME SHARP
H7-3 QVECTOR CNVGC/DIFFLUENT UPR FLOW IN EXIT REGION OF SUPPORTING
120KT H3 JET MAX/HGT FALLS AHEAD OF THIS FEATURE/SFC-6KM BULK SHEAR
UP TO 70 KTS...THE TS HAVE NOT INTENSIFIED AS THE LINE OF SHRA MOVES
E INTO WI EVEN THOUGH THERE HAVE BEEN SOME WIND GUSTS UP TO 40 KTS
OBSVD WHERE THE CONVECTION IS SFC BASED IN THE WARM SECTOR. MODERATE
RA IS FALLING IN THE COLDER AIR OVER MUCH OF NRN MN UNDER THE
SHARPLY NNE CYC FLOW TO THE N AND NW OF THE SFC LO...WITH N WIND
GUSTS 30-40 KTS. SN HAS MIXED IN WITH THE PCPN OVER NRN MN AS THESE
STRONG WINDS HAVE DRAWN COLDER AIR TO THE S. THE 00Z H85 WIND AT
ABERDEEN SDAKOTA WAS 75 KTS. 02Z NE WIND GUSTS DOWN THE W END OF LK
SUP REACHED 44 MPH AT ASX IN NW WI. NO SN IS FALLING UNDER THIS AREA
AS OF MIDNGT...BUT MUCH COLDER AIR LURKS JUST TO THE N...WITH 00Z
H85 TEMP -11C AT YPL.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 556 AM EDT MON APR 16 2012
MAIN FCST CONCERNS FOR TODAY INTO TNGT ARE POPS/PTYPE/POTENTIAL FOR
STRONG WINDS ASSOCIATED WITH CCB THAT WL SHIFT ACRS UPR MI AS THE
SHRTWV/SFC LO MOVES TO THE E.
TODAY...SFC LO IS PROGGED TO MOVE TO SE LK SUP/ERN UPR MI BY 18Z
BEFORE CONTINUING INTO QUEBEC BY 00Z. SINCE THE SHRTWV WL BE MOVING
INTO A ZONE OF UPR CONFLUENCE BTWN THE BASE OF UPR TROF CENTERED
NEAR HUDSON BAY AND UPR RDG IN THE SE CONUS...THE SHRTWV/SFC LO ARE
EXPECTED TO WEAKEN...ESPECIALLY THIS AFTN. EVEN SO...TIGHT PRES
GRADIENT/SHARP NLY FLOW ON THE WRN FLANK OF THE DEPARTING LO ARE
FCST TO ADVECT MUCH COLDER AIR LURKING TO THE N INTO THE UPR LKS.
EXPECT INCRSG POPS OVER THE W BY SUNRISE TO SPREAD EWD WITH THE
DEEPER MSTR UNDER THE CCB. FCST SDNGS STILL SHOW SOME SHARP COOLING
BLO ELEVATED WARM LYR...SO WL RETAIN MENTION OF SLEET IN THE
TRANSITION BTWN ALL RA AND MORE SN ONCE DEEPER COLD AIR ARRIVES OVER
THE W BY AFTN. BUT STRONG CAD/WEAKENING UPR DVGC AS JET CORE SHIFTS
TO THE NE WL TEND TO CAUSE THE CCB TO DECAY A BIT AS LARGER SCALE
QVECTOR DVGC DVLPS OVER THE CCB. ALTHOUGH FCST H85 TEMPS FALLING AS
LO AS -13C TO -15C BY 00Z COULD ADD SOME LK ENHANCED COMPONENT INTO
THE PCPN FIELD...WEAKENING DYNAMICS SHOULD LIMIT THIS POTENTIAL WITH
THE COLDEST AIR ARRIVING ONLY AFT 18Z ONCE LARGER SCALE QVECTOR DVGC
DOMINATED BY THE CAD IS IN PLACE. SO EXPECT SN ACCUMS TO BE SUB
ADVY. THE ARRIVAL OF THE COLDER AIR WL SHARPEN LLVL INSTABILITY AND
AID MIXING OF H925 WINDS UP TO 35 TO 45 KTS. ALTHOUGH THE APRCH FM
THE WSW OF THE SHARP PRES RISE CENTER WL RESULT IN ISALLOBARIC WIND
COMPONENT AT A RIGHT ANGLE OR EVEN OPPOSING THE GRADIENT FLOW AND
THE LO WL BE WEAKENING WITH TIME... THE MAGNITUDE OF THE GRADIENT
WIND IN CONCERT WITH FAVORABLE MIXING UNDER THE INCOMING THERMAL
TROF JUSTIFY ISSUANCE OF HI WIND ADVYS FOR EXPOSED LOCATIONS NEAR
THE LK SUP SHORE.
TNGT...AS HI PRES BLDS INTO THE WRN CWA OVERNGT...THE PRES GRADIENT
WL DIMINISH QUICKLY FOLLOWING PASSAGE OF PRES RISE CENTER TO THE E
AFT 00Z. SO EXPECT GUSTY WINDS TO DIMINISH QUICKLY THIS EVNG INTO
THE OVERNGT. BUMPED POPS UP TO LIKELY IN AREAS E OF MQT WITH H85
THERMAL TROF/TEMPS AS LO AS -13C TO -15C CONDUCIVE FOR SOME LES IN
MOIST CYC NW FLOW. SUBSIDENCE DROPPING INVRN AOB 3K FT/RISING H85
TEMPS/WEAKENING CYC FLOW OVERNGT WL CAUSE ANY SHSN TO DIMINISH
STEADILY AFT MIDNGT. CONSIDERING THE CHILL OF THE INCOMING
AIRMASS...PWAT FALLING BLO 0.25 INCH...AND THE PROSPECT OF CLRG OVER
THE INTERIOR W AS HI PRES BLDS OVHD...TENDED TO GO LOWER THAN
PREVIOUS FCST FOR MIN TEMPS IN THAT AREA.
TUE...HUDSON BAY HI PRES/DRY AIRMASS WL DOMINATE UPR MI...BRINGING
RELATIVELY DRY AND TRANQUIL WX. ALTHOUGH THERE WL BE SOME LINGERING
SC OVER MAINLY THE E HALF IN THE MRNG WITH LINGERING LIGHTER CYC
FLOW/LLVL MSTR/THERMAL TROF UNDER SUBSIDENCE INVRN...THIS CLD SHOULD
DISSOLVE BY AFTN WITH ARRIVAL OF SFC HI PRES RDG/ACYC FLOW AND
DAYTIME HEATING...GIVING WAY TO JUST SOME DIURNAL CU. MIXING TO H85
ON GFS FCST SDNGS WOULD YIELD HI TEMPS RANGING FM ARND 40 AT ERY TO
50 NEAR THE WI BORDER...BUT THE DAY WL BE COOLER NEAR THE MODIFYING
INFLUENCE OF THE LKS AS WEAK PRES GRADIENT IN THE AFTN WL ALLOW FOR
LK BREEZE DEVELOPMENT.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 556 AM EDT MON APR 16 2012
MUCH OF LONGER RANGE PORTION OF FCST IS DOMINATED BY NEGATIVE UPPER
AIR ANAMOLIES STATIONED OVER NORTHEAST PACIFIC OCEAN/GULF OF ALASKA
AND OVR HUDSON BAY INTO NUNAVUT CANADA. ZONAL FLOW FCST TO IMPACT
CONUS MUCH OF THE WEEK AND INTO NEXT WEEKEND AS WELL.
ATTM ONLY ONE SYSTEM IS SURE THING TO IMPACT THE AREA IN THE LONGER
TERM. THIS IS STILL OPEN TO CHANGE DEPENDING ON TRACK OF LATE WEEK
SYSTEM.
SHORTWAVE ON SOUTHERN EDGE OF TROUGH OVR NORTHEAST PACIFIC/GULF OF
ALASKA FCST TO SLIDE ACROSS ROCKIES INTO NORTHERN PLAINS ON TUESDAY
NIGHT AND PUSH ACROSS UPPER GREAT LAKES ON WEDNESDAY. SW WINDS AHEAD
OF SFC-H85 TROUGH BRINGS MUCH WARMER/MOIST AIR INTO UPR LAKES IN WAKE
OF THE EARLY WEEK CHILL. JET STREAKS SLIDING ACROSS THE NORTHERN
PLAINS AND OVR ONTARIO SHOULD HELP SYSTEM STAY FAIRLY ORGANIZED AS
IT CROSSES CWA ON WEDNESDAY. APPEARS THAT SYSTEM WILL BE COMPACT AS
IT MOVES THROUGH...LEADING TO A FAIRLY STRONG WIND FIELD IN THE
VCNTY. HAVE INCREASED WINDS ESPECIALLY IN THE WAKE OF THE LOW LATE
WEDNESDAY INTO WEDNESDAY NIGHT NEAR LAKE SUPERIOR.
PTYPE MAY BE ISSUE INITIALLY WITH SNOW OR EVEN FREEZING RAIN
POSSIBLE INTERIOR CNTRL /10Z-12Z ON WEDNESDAY/ AS SWATH OF
PRECIPITATION ARRIVES OVER PERSISTENT SHALLOW COLD AIR. ANY WINTRY
PRECIP SHOULD BE BRIEF THOUGH AS STRONG WARM AIR ADVECTION SFC-H85
QUICKLY BECOMES DOMINANT. ADDED TSRA FOR WEDNESDAY AS WELL DUE TO
STEEP H7-H5 LAPSE RATES AOA 8C/KM. PRETTY DYNAMIC SYSTEM LOOKS TO
AFFECT THE AREA. GIVEN CONVECTIVE POTENTIAL MAY SEE RAIN TOTALS OVR
0.25 INCH IN SOME AREAS. STILL SOME POTENTIAL FOR SNOW AS SYSTEM
EXITS ON WEDNESDAY NIGHT. 850MB/925MB TEMPS AS LOW AS -10C/-6C STILL
LEAVES POTENTIAL FOR BRIEF LAKE ENHANCED SNOW OVR HIGHER TERRAIN OF
WEST CWA IF ENOUGH MOISTURE REMAINS IN PLACE. JUST LOW CHANCE POPS
FOR NOW.
IN THE EXTENDED...FRIDAY SYSTEM IS BACK ON FOR AT LEAST THE
SOUTHEAST QUARTER OF THE CWA...AT LEAST ACCORDING TO ECMWF AND
CANADIAN. ECMWF HAS SHOWN THIS OFF AND ON FOR LAST FEW DAYS AND
LATEST GFS HAS TRENDED NORTH...THOUGH IS STILL MAINLY SOUTH OF CWA
WITH ITS AXIS OF MAX QPF. SINCE SFC LOW IS STILL FCST TO PASS MAINLY
OVR CNTRL GREAT LAKES EVEN ON THE ECMWF...PCPN IF IT OCCURS WOULD
LIKELY STAY MAINLY IN FORM OF SNOW. ECMWF WOULD POINT TO SEVERAL
INCHES OF ACCUMULATION OVR SE CWA JUST NORTH OF H85-H7 LOW TRACK.
SYSTEM IS STILL NEAR THE ALLUTIANS IN THE PACIFIC SO EXPECT MORE
JUMPING AROUND ON THE POSITION OF THE LOW YET THIS WEEK. SOMETHING
TO DEFINITELY KEEP AN EYE ON THOUGH.
BEYOND FRIDAY APPEARS DRY WEATHER IS IN STORE FOR NEXT WEEKEND. WILL
NOT BE ESPECIALLY WARM THOUGH AS LARGER SCALE TROUGH RESIDES OVR
MUCH OF EASTERN CANADA AND EASTERN CONUS. SFC-H85 RIDGE WILL BE
OVERHEAD LEADING TO LIGHT WINDS/LK BREEZES. BEST CHANCE FOR DAYTIME
TEMPS AT LEAST NEAR NORMAL WILL BE WELL INLAND FM THE LAKES TOWARD
WISCONSIN BORDER. COULD ALSO BE CHILLY NIGHTS AS WELL...WITH TEMPS
POSSIBLY IN THE TEENS AND 20S. EXPECT RELATIVE HUMIDITIES TO BE ON
THE LOW SIDE FOR THE WEEKEND AS WELL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 126 AM EDT MON APR 16 2012
FORECAST OVER THE NEXT 24 HOURS IS FAIRLY COMPLEX WITH A LOW
PRESSURE SYSTEM AND WARM FRONT SHIFTING NORTHEASTWARD THROUGH MUCH
OF THE UPPER PENINSULA.
KIWD AND KCMX...CONDITIONS WILL REMAIN NEAR ALT LANDING MINS THROUGH
AT LEAST LATE MORNING AS FLOW BCMS ONSHORE AND NERLY. COLD ADVECTION
BEHIND FRONT WILL TURN SHRA TO SHSH BY LATE MORNING AS NORTH WINDS
GUSTS FM 30-35 KT. EXPECT CONDITIONS TO IMPROVE TO MVFR BY LATE MON
AFTERNOON AS RDG BUILDING IN WILL KNOCK DOWN WINDS AND BRING IN
DRIER AIR. STEEP LOW-LVL LAPSE RATES WILL KEEP MVFR CLOUDS INTACT
HOWEVER. INCLUDED TS VCNTY AT KIWD IN THE FIRST COUPLE OVERNIGHT
HRS.
KSAW...EXPECT CONDITIONS TO IMPROVE TO MVFR THROUGH THE EARLY
MORNING WITH WARMING AND MIXING AHEAD OF THE FRONTAL SYSTEM. WINDS
WILL SHIFT NW AND BCM GUSTY AOA 30 KT BEHIND COLD FRONT WITH SHRA
CHANGING TO SHSN ALTHOUGH EXPECT GENERALLY MVFR CONDITIONS. RDGG FM
THE WEST WILL DIE DOWN WINDS TOWARD MON EVENING AS LAKE ENHANCED
SNOW ENDS. MVFR CLOUDS WILL REMAIN THROUGH 06Z TUE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 556 AM EDT MON APR 16 2012
CONSIDERING A NUMBER OF OBS SHOWING WIND GUSTS UP TO 50 KTS OVER THE
W HALF WHERE TERRAIN ENHANCES THE PREVAILING NE FLOW EARLY THIS
MRNG...OPTED TO ISSUE STORM WARNINGS FOR THE 3 WESTERN ZONES OF LAKE
SUPERIOR. AS THE FLOW BACKS TO N...EXPECT THE WINDS TO SUBSIDE A BIT
WITH JUST N GALES THRU THE AFTN AS THE ARRIVAL OF MUCH COLDER
ENHANCES MIXING OF HIER MOMENTUM TO THE LAKE SURFACE. EVEN THESE
WINDS WILL TEND TO DIMINISH OVER THE FAR W LATER IN THE DAY WITH
APPROACH OF HI PRES RIDGE. LINGERING GALES WILL END OVER THE REST OF
THE LAKE AS THE HI PRES RIDGE/WEAKER PRES GRADIENT DOMINATES THE
LAKE.
NEXT LOW PRES SYSTEM FCST TO MOVE THRU THE UPPER LAKES WED IS NOW
LOOKING STRONGER. EXPECT SOUTHERLY WINDS TO 30 KTS WEDNESDAY MORNING
TO SHIFT TO THE WEST AND INCREASE TO GALES ESPECIALLY OVER THE EAST
HALF OF THE LAKE BY LATER WEDNESDAY AFTN AND INTO THE EARLY EVENING.
WINDS DIMINISH BLO 25 KTS LATER WEDNESDAY NIGHT INTO THURSDAY AS
HIGH PRESSURE MOVES BACK OVR THE UPR LAKES REGION. SFC LOW PASSING
BY ACROSS THE CNTRL GREAT LAKES THURSDAY NIGHT INTO FRIDAY COULD
RESULT IN NORTHEAST WINDS 25-30 KTS OVR SOUTHERN PORTIONS OF LK
SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY FROM 10 AM THIS MORNING TO 4 PM EDT THIS AFTERNOON
FOR MIZ002-003.
WIND ADVISORY FROM 10 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR MIZ001.
WIND ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM EDT THIS EVENING
FOR MIZ006-007.
WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM EDT THIS EVENING
FOR MIZ005.
LAKE SUPERIOR...
GALE WARNING FROM 5 PM THIS AFTERNOON TO 2 AM EDT TUESDAY FOR
LSZ251-267.
GALE WARNING FROM 11 AM THIS MORNING TO 2 AM EDT TUESDAY FOR
LSZ266.
GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR LSZ265.
STORM WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ263-264.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 8 PM EDT THIS EVENING
FOR LSZ248-263-264.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 2 AM EDT TUESDAY FOR
LSZ249-250.
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LSZ242>245.
GALE WARNING UNTIL 2 PM EDT /1 PM CDT/ THIS AFTERNOON FOR LSZ240-
241.
STORM WARNING UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING FOR LSZ162.
GALE WARNING UNTIL 2 PM EDT /1 PM CDT/ THIS AFTERNOON FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
AVIATION...VOSS
MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
204 AM EDT MON APR 16 2012
.SYNOPSIS...
ISSUED AT 355 PM EDT SUN APR 15 2012
A STRONG COLD FRONT WILL CROSS SOUTHWEST LOWER MICHIGAN OVERNIGHT.
IT WILL ACCOMPANIED BY A LINE OF THUNDERSTORMS WITH GUSTY WINDS.
TEMPERATURES WILL FALL DURING MONDAY WITH GUSTY WINDS. EARLY MORNING
SHOWERS AND THUNDERSTORMS WILL GIVE WAY TO SCATTERED AFTERNOON
SHOWERS. THOSE COULD BE MIXED WITH WET SNOW OVER NORTHWEST
SECTIONS BY LATE AFTERNOON. SPRINKLES AND FLURRIES WILL END MONDAY
NIGHT AND THAT WILL LEAD TO CLEARING SKIES WITH FROST AND FREEZING
TEMPERATURES. A QUICK MOVING SYSTEM WILL BRING MORE SHOWERS TO THE
AREA WEDNESDAY.
&&
.UPDATE...
ISSUED AT 205 AM EDT MON APR 16 2012
WE HAVE ISSUED A WIND ADVISORY FOR THE ENTIRE CWFA VALID BEGINNING
IMMEDIATELY THROUGH 02Z TONIGHT. LLJ RESPONSIBLE FOR THE SHOWERS
AND STORMS LAST EVENING AND EARLY THIS MORNING IS NOW ALMOST
OVERHEAD. ALMOST ALL OF THE WIND THUS FAR HAS REMAINED
ALOFT DUE TO THE WAA...EVEN WITH SOME CONVECTION IN THE AREA. HOWEVER
ALONG AND BEHIND THE FRONT WHERE CAA IS NOW BEGINNING...BETTER
MIXING IS TAKING PLACE. THIS IS RESULTING IN NON-CONVECTIVE WIND
GUSTS OF 40 TO 55 MPH ACROSS THE LAKE OVER WISCONSIN. THESE WINDS
ARE STARTING TO SHOW UP AT KMKG AND KLDM WITH GUSTS UP TO 38 KNOTS
IN THE LAST HOUR.
WE EXPECT SOME OF THIS WIND TO AFFECT THE AREA THIS MORNING. THE
STRONGEST WIND WILL COME BEGINNING AROUND MID MORNING...AND LIKELY
LAST THROUGH EARLY EVENING WITH CAA AND DIURNAL MIXING. MOS WINDS ARE
QUITE IMPRESSIVE WITH SOME SUSTAINED 30 SHOWING UP THIS AFTERNOON.
UPDATE ISSUED AT 1055 PM EDT SUN APR 15 2012
WE HAVE ISSUED AN UPDATE THIS EVENING...MAINLY TO BUMP POPS UP TO
THE 90-100 PCT CATEGORY. AXIS OF BEST MOISTURE AHEAD OF THE FRONT IS
NOW LEANING INTO THE AREA FROM THE WEST. MOST LOCATIONS WILL GET
MEASURABLE PCPN BASED OFF OF THE COVERAGE OF PCPN TO OUR SOUTH
AND WEST. THIS ALL OCCURS AS THE STRONG LLJ AHEAD OF THE SYSTEM
WILL FEED STRONG MOISTURE TRANSPORT INTO THE AREA.
SEVERE THREAT IS QUITE LIMITED MAINLY DUE TO THE LACK OF SFC/ML BASED
INSTABILITY WE WERE UNABLE TO GENERATE OVER THE AREA TODAY WITH
PLENTY OF CLOUD COVER. THAT SAID...WE CAN NOT RULE OUT SOME
ISOLATED HAIL APPROACHING SEVERE LIMITS BASED ON STORMS EARLIER
NEAR CHICAGO. LOCAL WIND GUSTS CAN NOT BE RULED OUT EITHER WITH
THE STRONG WIND FIELDS OVERHEAD.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 355 PM EDT SUN APR 15 2012
THERE ARE SEVERAL ISSUES TO DEAL WITH DURING THE SHORT TERM PART
OF THE FORECAST. FIRST IS HOW STRONG WILL THE LINE OF THUNDERSTORMS
WITH THE COLD FRONT BE? THEN THERE IS THE ISSUE OF DO WE NEED A
WIND ADVISORY MONDAY AS THE COLD AIR COMES IN BEHIND THE COLD
FRONT. FINALLY THERE IS THE ISSUE OF A FREEZE MONDAY NIGHT.
AS FOR THE CONVECTION WITH THE COLD FRONT... OUR STORY REMAINS
UNCHANGED. THEN NAM 12Z... RUC 18Z ...GFS 12Z... AND ECMWF 12Z ALL
SHOW A 60 TO 70 KNOT LOW LEVEL JET COMING ON SHORE AROUND 2 AM THEN
REACHING EASTERN LOWER MICHIGAN BY 8 AM MONDAY. SINCE AT 18Z AND
19Z THE THUNDERSTORMS AREA WHERE THEY ARE SUPPOSE TO BE ON THE LEFT
SIDE OF THE LOW LEVEL JET... THAT MEANS THE MAIN LINE OF STORMS
WILL CROSS OUR CWA AROUND TO AFTER MIDNIGHT. WHAT HELPS TO KEEP
THE STORMS FROM GOING SEVERE OVER OUR CWA THROUGH IS THE JET CORE
AT 300 MB IS CURRENTLY SOUTHWEST OF MICHIGAN AND WILL NOT BE WEST
OF MICHIGAN UNTIL 2 AM. THAT MEANS THIS AREA WILL BE IN THE RIGHT
EXIT REGION OF THE UPPER JET CORE. THAT IS NOT CONDUCIVE TO SEVERE
STORMS. THE MOST UNSTABLE CAPE IN THE 950 TO 850 LAYER IS OVER
1500 J/KG OVER WI THIS EVENING BUT LESS THEN 400 J/KG OVER MI WHEN
THE LINE IS EXPECTED TO GET HERE. SO MY SPIN IS WE WILL SEE A
WEAKENING LINE OF STORMS COME INTO SOUTHWEST LOWER MICHIGAN AROUND
MIDNIGHT. THE LINE WILL WEAKEN AS IT CROSS THE CWA LATE TONIGHT.
ANY SEVERE WINDS WILL BE NEAR THE LAKE MICHIGAN SHORE AS THE
STORMS COME DOWN OFF THE MAINE LAYER.
THE DRY SLOT MOVES IN MID DAY MONDAY. SOUTHWEST MICHIGAN IS IN THE
DRY SLOT AND THERE IS 50 KNOTS IN THE MIXED LAYER AS THIS MOVES
ACROSS THE CWA. THIS WILL BRING OUR GUSTS CLOSE TO ADVISORY
CRITERIA WINDS BUT AT THIS POINT WE FEEL THIS IS OVER DONE BY THE
NAM SO WE WILL STAY JUST BELOW ADVISORY GUSTS.
WRAP AROUND MOISTURE MOVES IN DURING THE AFTERNOON SO SCATTERED
SHOWERS WILL MOVE INTO THE CWA BY EARLY TO MID AFTERNOON. THE AIR
BECOMES COLD ENOUGH FOR SNOW OVER THE NW CWA BY LATE AFTERNOON AND
OVER THE REST OF THE CWA BY MID EVENING. SO WE COULD SEE A FEW
SNOW FLAKES MONDAY EVENING. ENOUGH DRY AIR MOVES IN BEHIND THE
SYSTEM AFTER MIDNIGHT TO CLEAR THE SKIES AND THIS LEAD TO FROST
AND FREEZING TEMPERATURES. WE WILL LIKELY NEED A FREEZE WARNING
FOR TUESDAY MORNING.
$$
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 355 PM EDT SUN APR 15 2012
COOL AND DRY HIGH PRESSURE WILL BE SETTLING OVER THE REGION FOR
THE START OF LONG TERM. TUESDAY NIGHT COULD SEE MORE FROST WITH
TEMPS DIPPING TO AROUND 30 OVER THE INTERIOR NORTH...AND UPPER 30S
OVER THE SOUTHERN NEAR SHORE.
HAVE PUSHED THE POPS BACK A BIT ON WED. LOOKS LIKE ANY PCPN WILL
HOLD OFF UNTIL WED AFTERNOON...AND MAYBE NOT UNTIL AFTER NIGHTFALL
IN THE EAST. ANOTHER RATHER WOUND-UP NORTHERN STREAM SYSTEM WILL BE
MOVING ALONG THE U.S./CANADIAN BORDER...DRAGGING A COLD FRONT
THROUGH LOWER MICHIGAN WED NIGHT. AFTER A BRIEF BREAK FROM THE PCPN
ON THURSDAY...THE FRONT WILL STALL TO OUR SOUTH WITH A WAVE OF LOW
PRESSURE TRACKING ALONG IT. NOT GOOD AGREEMENT IN THE MODELS WITH
THE POSITION OF THIS LOW WITH THE EURO MUCH FURTHER NORTH THAN THE
GFS. THIS IS CAUSED BY THE FURTHER NORTHERLY POSITION OF THE
BAROCLINIC ZONE ON THE EURO. LOOKS LIKE THE HIGH OVER SOUTHERN
CANADA WILL BE THE DECIDER...IF THIS PROVES TO BE STRONGER THE PCPN
WILL STAY SOUTH. WILL SEE HOW THIS PANS OUT...FOR NOW HAVE
CONTINUED THE CHC POPS...HIGHEST SOUTH FOR THURSDAY NIGHT AND FRIDAY.
EVEN THE EURO EXITS ANY LINGER PCPN BY FRIDAY NIGHT. NEXT WEEKEND
LOOKS DRY WITH HIGH PRESSURE SLOWLY BUILDING IN. HOWEVER...IT DOES
APPEAR TO REMAIN COOL WITH MAX TEMPS MAINLY 50 TO 55...AND MAYBE
HOLDING IN THE 40S ALONG THE LAKESHORE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 205 AM EDT MON APR 16 2012
MAIN CONCERNS WITH THE 06Z SET OF FCSTS WILL BE PCPN TRENDS
THROUGH THIS EVENING...AND WIND TRENDS.
STORMS HAVE MOVED THROUGH THE AREA LAST EVENING AND EARLY THIS
MORNING....AND HAVE WEAKENED. SOME LIGHT RAIN REMAINS OVER THE
AREA...JUST OUT AHEAD OF THE INCOMING COLD FRONT THAT WILL MOVE
THROUGH IN THE NEXT FEW HOURS FROM WEST TO EAST. RAINFALL WILL
TEMPORARILY END WITH THE FRONTAL PASSAGE. BEHIND THE FRONTAL
PASSAGE...WINDS ARE INCREASING SIGNIFICANTLY OUT OF THE SOUTH.
WINDS GUSTS OF 38 TO 35 KNOTS HAVE BEEN OBSERVED AT KMKG AND KLDM
RESPECTIVELY.
ONCE THE WINDS COME UP BEHIND THE FRONT THIS MORNING...THEY WILL
REMAIN UP INTO THIS EVENING. WE ARE EXPECTING TO SEE GUSTS PEAK
AROUND 40 KNOTS THIS AFTERNOON WITH DAYTIME HEATING AND COLDER AIR
COMING IN. SHOWERS WILL ONCE AGAIN BE POSSIBLE THIS AFTERNOON AS
THE WRAP AROUND MOISTURE ROTATES IN. THE SHOWERS WILL REMAIN
POSSIBLE INTO THIS EVENING BEFORE THEY WILL END AND SKIES WILL
CLEAR. WINDS WILL ALSO DIMINISH BELOW 20 KNOTS AT THAT TIME.
&&
.MARINE...
ISSUED AT 205 AM EDT MON APR 16 2012
WE HAVE GONE AHEAD AND PUSHED UP THE TIMING OF THE GALE WARNING TO
THE CURRENT TIME. THE STRONG WINDS ACROSS WISCONSIN ARE NOW BEING
OBSERVED ON THIS SIDE OF THE LAKE. GALES WILL CONTINUE TO BE
EXPECTED THROUGH EARLY THIS EVENING BEFORE DIMINISHING.
&&
.HYDROLOGY...
ISSUED AT 355 PM EDT SUN APR 15 2012
THERE WAS BETWEEN A HALF INCH AND TWO INCHES OF RAIN EARLY THIS
MORNING OVER MOST OF THE CWA. THE USGS PAGE SHOWS RIVER AND STREAM
LEVELS NEAR AND SOUTH OF I-96 ROSE SHARPLY THIS MORNING BUT REMAIN
WILL BELOW NORMAL NORTH OF I-96. THE RAINFALL THIS EVENING SHOULD
BE LESS THAN A HALF INCH AND HAVE LITTLE IMPACT ON STREAM LEVELS.
ONLY SYCAMORE CREEK NEAR HOLT IS FORECAST TO RISE TO NEAR ADVISORY
STAGE. WE WILL CONTINUE TO MONITOR THIS. THE BOTTOM LINE IS WE DO
NOT AT THIS POINT SEE MAJOR FLOODING ISSUES AT THIS TIME.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR MIZ037>040-
043>046-050>052-056>059-064>067-071>074.
LM...GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR LMZ844>849.
&&
$$
UPDATE...NJJ
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...JK
AVIATION...NJJ
HYDROLOGY...WDM
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
126 AM EDT MON APR 16 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 446 PM EDT SUN APR 15 2012
SHORT TERM FCST HAS BEEN A CHALLENGE TODAY WITH IMPORTANT DETAILS TO
CAPTURE IN THE GRIDS WITH NEARLY ALL FCST ELEMENTS... INCLUDING
SIGNIFICANT NON-DIURNAL TEMPS TRENDS...GALES ON THE LAKE/POSSIBLE
ADVY WINDS INLAND...POSSIBLE SVR TSRA TONIGHT...AND MIX PCPN ISSUES
MON.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS SHORTWAVE
LIFTING NE THRU THE WRN PLAINS. SFC LOW IS OVER NE NEBRASKA WITH SFC
WARM FRONT EXTENDING NE TO NEAR KMSP THAN E TO JUST N OF KGRB. FRONT
HAS MADE LITTLE PROGRESS OVER THE LAST FEW HRS...AND SO FAR...THERE
HASN`T BEEN MUCH SHRA ACTIVITY N OF THE FRONT. STRONGER LOW-MIDLEVEL
FRONTOGENESIS IS SUPPORTING BEST SHRA DEVELOPMENT TO THE W IN NE
MN/WRN LAKE SUPERIOR. HOWEVER...WITH MODELS INDICATING MOISTURE
TRANSPORT BECOMING FOCUSED TOWARD UPPER MI OVER THE NEXT FEW HRS...
SHRA SHOULD EXPAND OVER THE FCST AREA. WITH ELEVATED CAPE ALSO
INCREASING...ISOLD/SCT TSRA SHOULD ALSO DEVELOP. SVR THREAT IS
UNCERTAIN TONIGHT DUE TO UNCERTAINTY IN PROGRESS OF WARM FRONT. IF
FRONT LINGERS TO S THIS EVENING AND ELEVATED STORMS DO DEVELOP...
EFFECTIVE SHEAR WILL SUPPORT ORGANIZED UPDRAFTS AND A HAIL
POTENTIAL...ESPECIALLY OVER THE SCNTRL. IF WARM FRONT LIFTS N THRU
CNTRL/ERN UPPER MI...THERE MAY NOT BE MUCH ACTIVITY UNTIL COLD FRONT
ARRIVES LATE TONIGHT WHEN INSTABILITY WILL BE DIMINISHING. AT THIS
POINT...ELEVATED SVR STORMS APPEAR THE MORE LIKELY SCENARIO IF
STORMS CAN ORGANIZE N OF SLOW MOVING WARM FRONT. TEMPS TONIGHT WILL
ALSO BE HIGHLY DEPENDENT ON WARM FRONT LOCATION. TEMPS MAY RISE
ACROSS THE CNTRL/E WHILE A CHILLY E WIND KEEPS READINGS OVER THE
KEWEENAW IN THE LWR 40S. FOG MAY BE DENSE AT TIMES WHERE FLOW IS
UPSLOPE OFF LAKE SUPERIOR AND LAKE MICHIGAN.
SFC LOW WILL TRACK ACROSS CNTRL UPPER MI/SE LAKE SUPERIOR LATE
TONIGHT/MON MORNING. SHARP/STRONG CAA MON WILL BRING A QUICK DROP IN
TEMPS FROM NW TO SE AFTER COLD FROPA. FCST SOUNDINGS SUGGEST AT
LEAST SOME POTENTIAL FOR A BRIEF PERIOD OF SLEET BTWN THE TRANSITION
FROM RAIN TO SNOW. LOW-LEVEL TEMPS ALSO APPEAR TO FALL ENOUGH FOR
SOME LAKE ENHANCEMENT IN THE DEFORMATION PCPN AREA SWINGING ACROSS
UPPER MI MON. RIGHT NOW...EXPECT 1 TO 2 INCHES OF SNOW MON OVER THE
W AND NCNTRL. HIGH TERRAIN OF THE FAR W MAY SEE UP TO 3 INCHES.
COULD BE A SNOW ADVY EVENT IF DEFORMATION PCPN SHIELD BECOMES WELL
ORGANIZED TO THE W TONIGHT. AS FOR WINDS...SHARP CAA WILL ENHANCE
LOW-LEVEL MIXING...AND WITH 40-45KT AVBL IN THE MIXED LAYER...ADVY
LEVEL WINDS ARE A GOOD BET NEAR LAKE SUPERIOR MON...ESPECIALLY
KEWEENAW COUNTY BEGINNING IN THE MORNING AND FROM KMQT EASTWARD IN
THE AFTN. ISALLOBARIC COMPONENT TO THE WIND ROUGHLY 90 DEGREES TO
THE GRADIENT WIND SHOULD KEEP THIS FROM BEING A HIGHER END WIND
EVENT. TEMPS WILL FALL FROM NW TO SE THRU THE DAY...THOUGH THERE
WILL BE SOME WARMING OVER THE E MON MORNING PRIOR TO COLD FROPA.
TEMPS IN THE AFTN WILL PROBABLY BE AT OR BELOW FREEZING OVER THE W
AND NCNTRL.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 446 PM EDT SUN APR 15 2012
NO SIGNIFICANT CHANGES TO UPPER PATTERN DEPICTION SHOWN BY MEDIUM
RANGE MODELS YDY WITH NEGATIVE ANAMOLIES STATIONED OVER NORTHEAST
PACIFIC OCEAN/GULF OF ALASKA AND OVR HUDSON BAY INTO NUNAVUT CANADA.
ZONAL FLOW DOMINATES CONUS MUCH OF THE WEEK AND REALLY INTO NEXT
WEEKEND AS WELL. ATTM ONLY ONE SYSTEM WILL IMPACT THE AREA IN THE
LONGER TERM...BUT THAT MAY CHANGE DEPENDING ON TRACK OF LATE WEEK
SYSTEM.
BLAST OF WINTRY WEATHER GRADUALLY DIMINISHES ON MONDAY NIGHT. PLENTY
OF 925-850MB MOISTURE...CYCLONIC SFC-H85 FLOW...AND 900 TEMPS AROUND
-10C SO PREFER TO LET SNOW SHOWERS LINGER ALONG LK SUPERIOR INTO THE
OVERNIGHT HOURS FOR AREAS FAVORED BY NW WINDS. ADDITIONAL SNOW
ACCUMS MONDAY NIGHT WILL STILL BE MINIMAL. MAIN ISSUE WILL BE GUSTY
NORTH-NORTHWEST WINDS UP TO 45 MPH ALONG LK SUPERIOR ALONG WITH THE
SNOW SHOWERS. ARRIVAL OF LOW-LEVEL RIDGE DIMINISHES SNOW SHOWERS
TOWARD MORNING OVER EASTERN CWA. SFC RIDGE AND EDGE OF THERMAL TROUGH
RESULTS IN LIGHT WINDS/COOL CONDITIONS ON TUESDAY. COOLEST READINGS
AROUND 40 DEGREES ALONG LK SUPERIOR WITH NE WINDS.
SHORTWAVE ON SOUTHERN EDGE OF TROUGH OVR GULF OF ALASKA FCST TO
SLIDE ACROSS ROCKIES INTO NORTHERN PLAINS BY TUESDAY NIGHT AND PUSH
ACROSS UPPER GREAT LAKES ON WEDNESDAY. SW WINDS AHEAD OF SFC-H85
TROUGH HELP TO BRING MUCH WARMER AIR INTO UPR LAKES IN WAKE OF EARLY
WEEK CHILL AND INCREASING MOISTURE AS WELL. JET STREAKS SLIDING
ACROSS THE NORTHERN PLAINS AND OVR ONTARIO SHOULD HELP SYSTEM STAY
FAIRLY ORGANIZED AS IT CROSSES CWA ON WEDNESDAY. MSLP FCSTS DEPICT
THIS AS WELL WITH PRESSURES STEADY OR EVEN SLOWLY FALLING FM TUESDAY
NIGHT INTO WEDNESDAY ACROSS UPPER LAKES. GIVEN OVERALL DRY PATTERN
WE ARE IN CANNOT GET TOO EXCITED ABOUT SIGNIFICANT PRECIPITATION
WITH THE SYSTEM...BUT TOTAL LIQUID COULD CHECK IN AROUND 0.25 INCH
IN SOME AREAS. PTYPE MAY BE ISSUE INITIALLY LATE TUESDAY NIGHT OVER
THE WEST AS SHALLOW COLD AIR HANGS TOUGH IN WAKE OF COLD PUSH EARLY
IN THE WEEK. LATEST MODEL RUNS INDICATE POTENTIAL FOR FROZEN PRECIP
IS NOT AS HIGH AS BEFORE AS SOUTH WINDS ADVECT WELL ABOVE FREEZING
DWPNTS INTO UPR MI BY DAYBREAK WEDNESDAY. OVERALL...MAY BE SOME SNOW
OR PERHAPS FREEZING RAIN...BUT AS IT STANDS NOW IT WOULD BE PRETTY
SHORT LIVED. SOME POTENTIAL SOME SNOW AS SYSTEM EXITS ON WEDNESDAY
NIGHT. 850MB/925MB TEMPS AS LOW AS -10C/-6C WOULD EVEN OPEN DOOR TO
BRIEF LAKE ENHANCED SNOW OVR HIGHER TERRAIN OF WEST GIVEN ENOUGH
MOISTURE REMAINS AS COLDER AIR WORKS INTO UPR LAKES REGION.
IN THE EXTENDED...FRIDAY SYSTEM THAT ECMWF HAS BEEN SHOWING OFF AND
ON THE LAST FEW DAYS WAS OFF ON THE 00Z RUN BUT IS KIND OF BACK ON
AGAIN WITH THE 12Z RUN...THOUGH BULK OF HEAVIER QPF REMAINS SOUTH OF
UPR MI. GFS IS MUCH FARTHER SOUTH. SOUTHERN TRACK DOES MAKE SOME
SENSE AS PRIMARY FRONTAL BOUNDARY IS FCST TO SETTLE INTO THE
NORTHERN PORTIONS OF THE OHIO VALLEY IN WAKE OF THE WEDNESDAY SYSTEM
AND SINCE BETTER CHANCE OF CYCLOGENESIS WOULD BE ALONG THE BETTER
SFC TEMPERATURE GRADIENT. SYSTEM IS STILL NEAR THE ALLUTIANS IN THE
PACIFIC SO THERE LIKELY WILL BE SOME JUMPING AROUND ON THE POSITION
OF THE LOW YET THIS WEEK. FOR NOW THOUGH...POPS WILL STAY ON THE LOW
SIDE FOR THIS SYSTEM WITH THE HIGHER POPS OVER THE SOUTHERN CWA
THURSDAY NIGHT AND FRIDAY. ECMWF IDEA FM 12Z/14 APRIL AND 12Z THIS
MORNING WOULD INDICATE SIGNIFICANT SNOW OVR PORTIONS OF UPR LAKES
INCLUDING UPR MI.
BEYOND FRIDAY APPEARS DRY WEATHER IS IN STORE FOR NEXT WEEKEND. WILL
NOT BE ESPECIALLY WARM THOUGH AS LARGER SCALE TROUGH RESIDES OVR
MUCH OF EASTERN CANADA AND EASTERN CONUS. MODELS SHOW ANOTHER WAVE
DIVING IN FM THE PACIFIC TROUGH BUT WITH EXPECTED AMPLITUDE OF
TROUGH THIS SYSTEM WILL PROBABLY STAY TO THE SOUTH OF UPR LAKES AS
THE LATE WEEK ONE DOES. SFC-H85 RIDGE WILL BE OVERHEAD LEADING TO
LIGHT WINDS/LK BREEZES. BEST CHANCE FOR DAYTIME TEMPS AT LEAST NEAR
NORMAL WILL BE WELL INLAND FM THE LAKES TOWARD WISCONSIN BORDER.
COULD ALSO BE CHILLY NIGHTS AS WELL...WITH TEMPS POSSIBLY IN THE
TEENS AND 20S. RELATIVE HUMIDITIES LIKELY WILL BE ON THE LOW SIDE
FOR THE WEEKEND AS WELL.
APPEARS PATTERN BEGINS TO CHANGE DAYS 8-10 OR STARTING ON 24 APRIL
AS STRONG RIDGE BUILDS FM CNTRL CONUS INTO WESTERN GREAT LAKES.
GIVEN LACK OF RAINFALL THIS MONTH AND SINCE WE ARE STILL NOT
COMPLETELY GREENED UP OVR UPR MI...THE WARMER AND DRY WEATHER WILL
PROBABLY LEAD TO INCREASING FIRE WEATHER ISSUES. PLENTY OF TIME TO
DIAGNOSE THIS THOUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 126 AM EDT MON APR 16 2012
FORECAST OVER THE NEXT 24 HOURS IS FAIRLY COMPLEX WITH A LOW
PRESSURE SYSTEM AND WARM FRONT SHIFTING NORTHEASTWARD THROUGH MUCH
OF THE UPPER PENINSULA.
KIWD AND KCMX...CONDITIONS WILL REMAIN NEAR ALT LANDING MINS THROUGH
AT LEAST LATE MORNING AS FLOW BCMS ONSHORE AND NERLY. COLD ADVECTION
BEHIND FRONT WILL TURN SHRA TO SHSH BY LATE MORNING AS NORTH WINDS
GUSTS FM 30-35 KT. EXPECT CONDITIONS TO IMPROVE TO MVFR BY LATE MON
AFTERNOON AS RDG BUILDING IN WILL KNOCK DOWN WINDS AND BRING IN
DRIER AIR. STEEP LOW-LVL LAPSE RATES WILL KEEP MVFR CLOUDS INTACT
HOWEVER. INCLUDED TS VCNTY AT KIWD IN THE FIRST COUPLE OVERNIGHT
HRS.
KSAW...EXPECT CONDITIONS TO IMPROVE TO MVFR THROUGH THE EARLY
MORNING WITH WARMING AND MIXING AHEAD OF THE FRONTAL SYSTEM. WINDS
WILL SHIFT NW AND BCM GUSTY AOA 30 KT BEHIND COLD FRONT WITH SHRA
CHANGING TO SHSN ALTHOUGH EXPECT GENERALLY MVFR CONDITIONS. RDGG FM
THE WEST WILL DIE DOWN WINDS TOWARD MON EVENING AS LAKE ENHANCED
SNOW ENDS. MVFR CLOUDS WILL REMAIN THROUGH 06Z TUE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 446 PM EDT SUN APR 15 2012
SFC LOW TRACKING FROM NE NEBRASKA TO UPPER MI/SE LAKE SUPERIOR
TONIGHT/MON MORNING WILL BRING A NE TO N GALE EVENT TO LAKE SUPERIOR
TONIGHT AND MON. GALES HAVE BEEN A LITTLE SLOW TO DEVELOP OVER THE
FAR W THIS AFTN...BUT WINDS SHOULD QUICKLY RAMP UP OVER THE NEXT FEW
HRS AS PRES FALLS INCREASE IN MAGNITUDE TO THE SW OF THE LAKE AHEAD
OF THE APPROACHING SFC LOW. AS THE LOW SHIFTS ACROSS UPPER MI/SE
LAKE SUPERIOR AND THEN E MON...NE WINDS WILL BACK N WITH GALES
QUICKLY EXPANDING E ACROSS THE LAKE. SHARP CAA/STRONG LOW-LEVEL
INSTABILITY WILL SUPPORT FREQUENT HIGH END GALE GUSTS. WINDS WILL
DIMINISH TO UNDER 20KT FROM W TO E MON NIGHT/EARLY TUE AS HIGH PRES
RIDGE BUILDS SE TO THE UPPER LAKES. LIGHTER WINDS WILL PERSIST THRU
TUE AFTN. NEXT LOW PRES SYSTEM MOVING THRU THE UPPER LAKES WED WILL
BRING ANOTHER PERIOD OF 15-25KT WINDS WED/THU...WITH THE STRONGER
WINDS AFFECTING MAINLY THE E HALF OF THE LAKE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 5 PM THIS AFTERNOON TO 2 AM EDT TUESDAY FOR
LSZ251-267.
GALE WARNING FROM 11 AM THIS MORNING TO 2 AM EDT TUESDAY FOR
LSZ266.
GALE WARNING UNTIL 2 PM EDT /1 PM CDT/ THIS AFTERNOON FOR LSZ162.
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LSZ242>244-263-264.
GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR LSZ265.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 2 AM EDT TUESDAY FOR
LSZ249-250.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 8 PM EDT THIS EVENING
FOR LSZ248.
GALE WARNING FROM 5 AM EARLY THIS MORNING TO 8 PM EDT THIS
EVENING FOR LSZ245.
GALE WARNING UNTIL 11 AM EDT /10 AM CDT/ THIS MORNING FOR LSZ240-
241.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED FOR 18Z TAFS
NWS TWIN CITIES/CHANHASSEN MN
100 PM CDT MON APR 16 2012
.DISCUSSION...ISSUED 352 AM CDT
MID/UPPER LEVEL CIRCULATION WILL CONTINUE TO CAUSE LIGHT PRECIP
OVER EASTERN AREAS THIS MORNING WITH LATEST RUC PICKING UP ON A
SSW-NNE BAND OF FGEN..PRIMARILY OVER EAST CENTRAL MN BUT THEN
WEAKENING WITH TIME OVER WEST CENTRAL WI. IT DOES LOOK LIKE LOW
LEVEL THICKNESSES WILL BE COLD ENOUGH TO SUPPORT SOME SNOW OR A
LEAST A RAIN AND SNOW MIX FARTHER SOUTHEAST TOWARD STC/MSP. STILL
AT WIND ADVSY CRITERIA OVER WEST CENTRAL MN AND STRONGER WINDS
WILL LIKELY LAST THROUGH THE MORNING IN THE EASTERN AREAS OF
CURRENT ADVSY. BAND OF 40 KNOT WINDS AT AROUND 925 MB OVER
FAVORED WINDY AREAS SHOWING UP ON THE RUC AND SOME OF THE WIND
GUST PRODUCTS MATCHING AS WELL. IT MIGHT BE CLOSE FOR SOME OF THE
STRONG WINDS FARTHER EAST TOWARD MSP BUT NOT LASTING REAL LONG.
CLEARING BUILDING IN TONIGHT AND THE CURRENT MENTION OF FROST LOOKS
OK UNDER TH RIDGE. STILL RATHER ACTIVE FOR THE REST OF THE WEEK WIT
A COUPLE OF DECENT WAVE IN THE STRONG WESTERLY FLOW. THE SYSTEM
FORECAST TO MOVE INTO THE AREA ON TUESDAY NIGHT AND WEDNESDAY DOES
HAVE SOME INSTABILITY ALONG WITH A WELL DEFINED DIFLUENT FLOW
PATTERN AND PV. HAVE RAISED POPS A BIT MORE INTO THE LIKELY
CATEGORY AND AT LEAST ISOLATED THUNDER LOOKS GOOD PRIMARILY OVER
SOUTH CENTRAL MINNESOTA. THE NEXT SYSTEM IS SIMILAR BUT
INSTABILITY MUCH FARTHER SOUTH...AND MORE OF AN ISENTROPIC LIFT
BAND OF FORCING AFFECTING MAINLY SOUTHERN MN. LOOKS LIKE A QUIET
PERIOD FOR LATER IN THE WEEK AND THE WEEKEND WITH BOTH GFS AND
ECMWF SHOWING AN UPPER RIDGE DEVELOPING IN THE CENTRAL CONUS OR
JUST SLIGHTLY WEST.
&&
.AVIATION.../18Z TAF ISSUANCE/
WIDESPREAD MVFR CIGS ACROSS AREA...BUT SUBSIDENCE IN WAKE OF MASSIVE
LOW PRESSUE LIFTING NE OF AREA HAS SCOURED OUT BINOVC ACROSS MUCH OF
W MN. EXPECT TO SEE SOME THINNING OF CLOUDS FARTHER EAST DURING THE
AFTN WITH BASES SLOWLY LIFTING INTO HIGH END MVFR CIGS. EXPECT A
CONTINUED DECREASE IN THESE CLDS ACROSS AREA THIS EVENING AND INTO
THE OVERNIGHT WITH MVFR CIGS IN THE DKTS STAYING MAINLY WEST OF
TAFS. WITH WDSRPD RAINS OVER THE WEEKEND...THERE IS SOME THREAT FOR
FOG IN EASTERN TAF AREAS AS HIGH PRESSURE MOVES ACROSS OVERNITE.
PUT A PRD OF MVFR FOG AT STC FROM AROUND 05-09Z WITH PRESSURE
GRADIENT PICKING UP LATE TONGIHT. A BETTER CHC OF FOG AT EAU AND
PERHAPS RNH LAT TONIGHT. A COUPLE OF WEAK VORTS UPSTREAM IN THE
DKTS WITH ONE NEAR DVL AND THE OTHER W OF PIR. THEY MAY BRING A FEW
MID CLDS INTO W MN AS THEY DIVE SE. GUSTY NW WINDS WILL CONTINUE TO
DECREASE FROM WEST TO EAST ACROSS AREA AS DEEP SFC LOW LIFTS RPDLY
NE OF AREA NAND HIGH PRESSURE BUILDS ACROSS AREA.
KMSP...MVFR CIGS WILL CONTINUE THRU AFTN WITH BASES VERY SLOWLY
RISING AND BECOMING VFR AFT 01Z. NW WINDS TO SLOWLY DMNSH DRNG THE
AFTN WITH SPEEDS LESS THAN 10 KTS BY 01Z AND THEN LGT WINDS DRNG THE
OVERNITE...BECOMING SE ON TUESDAY MRNG.
OUTLOOK TUESDAY...VFR.
TUE NITE INTO WED NITE...VFR TO PSBL MVFR WITH -SHRA.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/BAP
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
352 AM CDT MON APR 16 2012
.DISCUSSION...
MID/UPPER LEVEL CIRCULATION WILL CONTINUE TO CAUSE LIGHT PRECIP
OVER EASTERN AREAS THIS MORNING WITH LATEST RUC PICKING UP ON A
SSW-NNE BAND OF FGEN..PRIMARILY OVER EAST CENTRAL MN BUT THEN
WEAKENING WITH TIME OVER WEST CENTRAL WI. IT DOES LOOK LIKE LOW
LEVEL THICKNESSES WILL BE COLD ENOUGH TO SUPPORT SOME SNOW OR A
LEAST A RAIN AND SNOW MIX FARTHER SOUTHEAST TOWARD STC/MSP. STILL
AT WIND ADVSY CRITERIA OVER WEST CENTRAL MN AND STRONGER WINDS
WILL LIKELY LAST THROUGH THE MORNING IN THE EASTERN AREAS OF
CURRENT ADVSY. BAND OF 40 KNOT WINDS AT AROUND 925 MB OVER
FAVORED WINDY AREAS SHOWING UP ON THE RUC AND SOME OF THE WIND
GUST PRODUCTS MATCHING AS WELL. IT MIGHT BE CLOSE FOR SOME OF THE
STRONG WINDS FARTHER EAST TOWARD MSP BUT NOT LASTING REAL LONG.
CLEARING BUILDING IN TONIGHT AND THE CURRENT MENTION OF FROST LOOKS
OK UNDER TH RIDGE. STILL RATHER ACTIVE FOR THE REST OF THE WEEK WIT
A COUPLE OF DECENT WAVE IN THE STRONG WESTERLY FLOW. THE SYSTEM
FORECAST TO MOVE INTO THE AREA ON TUESDAY NIGHT AND WEDNESDAY DOES
HAVE SOME INSTABILITY ALONG WITH A WELL DEFINED DIFLUENT FLOW
PATTERN AND PV. HAVE RAISED POPS A BIT MORE INTO THE LIKELY
CATEGORY AND AT LEAST ISOLATED THUNDER LOOKS GOOD PRIMARILY OVER
SOUTH CENTRAL MINNESOTA. THE NEXT SYSTEM IS SIMILAR BUT
INSTABILITY MUCH FARTHER SOUTH...AND MORE OF AN ISENTROPIC LIFT
BAND OF FORCING AFFECTING MAINLY SOUTHERN MN. LOOKS LIKE A QUIET
PERIOD FOR LATER IN THE WEEK AND THE WEEKEND WITH BOTH GFS AND
ECMWF SHOWING AN UPPER RIDGE DEVELOPING IN THE CENTRAL CONUS OR
JUST SLIGHTLY WEST.
&&
.AVIATION.../06Z TAF ISSUANCE/
MOST OF THE CONVECTION/THUNDERSTORMS HAD LIFTED WELL OFF TO THE EAST
OVER NORTHEAST WISCONSIN. STRONG AREA OF LOW PRESSURE HAD MOVED INTO
SOUTHERN MINNESOTA. STRONG NORTHERLY WINDS WERE OCCURRING OVER
WESTERN AND CENTRAL MN...AND SHOULD DEVELOP OVER INTO PORTIONS OF
SOUTH CENTRAL MINNESOTA DURING THE OVERNIGHT HOURS. UPPER LOW HAD
LIFTED NORTH OVER CENTRAL MN...WITH DEFORMATION AXIS EXTENDING FROM
THE UPPER GREAT LAKES BACK OVER INTO EASTERN SOUTH DAKOTA. THE LOW
WILL CONTINUE TO SQUEEZE OUT SOME PRECIPITATION ACROSS THE UPPER
MIDWEST TONIGHT AND MONDAY. THE PRECIPITATION HAD SWITCH OVER TO
LIGHT SNOW NEAR KAXN. AS LOWER LEVELS CONTINUE TO COOL BELOW
FREEZING...THE RAIN WILL BECOME MIXED OR CHANGE OVER TO SNOW OVER
CENTRAL AND THE REST OF SOUTHWEST MN OVERNIGHT. THE LATEST WEATHER
DEPICTION MAP...SHOWED AN AREA OF LOW CLOUDS ALONG THE NORTHERN
PERIMETER OF THE SFC LOW OVER PARTS OF SOUTHERN MN AND NORTHERN
WISCONSIN. CEILING WILL CONTINUE TO LOWER IN THE NEW RICHMOND AND
EAU CLAIRE AREAS AFTER MIDNIGHT. ELSEWHERE...EXPECT WIDESPREAD
MVFR/IFR CONDITIONS THROUGH THE BULK OF THE PERIOD. CONDITIONS WILL
BEGIN TO IMPROVE LATE IN THE DAY ON MONDAY AS DRIER AIR FILTER OVER
THE AREA.
KMSP...SOME PATCHY IFR CONDITIONS THROUGH EARLY MONDAY
MORNING...THEN MARGINAL VFR CONDITIONS PREVAILING THE BULK OF THE
DAY MONDAY. BECOMING VFR BY MONDAY EVENING.
OUTLOOK MON NIGHT/TUESDAY...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR BLUE EARTH-BROWN-
DOUGLAS-FARIBAULT-FREEBORN-KANDIYOHI-LE SUEUR-MARTIN-MCLEOD-
MEEKER-NICOLLET-POPE-RENVILLE-SIBLEY-STEARNS-STEELE-WASECA-
WATONWAN.
WIND ADVISORY UNTIL 7 AM CDT THIS MORNING FOR CHIPPEWA-LAC QUI
PARLE-REDWOOD-STEVENS-SWIFT-YELLOW MEDICINE.
WI...NONE.
&&
$$
JPR/JVM
AREA FORECAST DISCUSSION
NWS JACKSON MS
927 PM CDT TUE APR 17 2012
.UPDATE...PRECIP HAS GENERALLY ENDED OVER THE FORECAST AREA. HAVE
MAINTAINED A SLIGHT CHANCE OF RAIN OVER EXTREME ERN ZONES NEAR THE
MS BORDER AS THESE AREAS ARE IN CLOSEST TO THE BETTER FORCING FOUND
TO OUR E/SE. THE SECOND PUSH OF RAIN EARLIER SUGGESTED BY THE HIGH
RES MODELS IS NOW BEING DOWNPLAYED SO WILL GENERALLY KEEP THE REGION
DRY FOR TONIGHT. NO OTHER CHANGES WERE MADE TO THE PREVIOUS FORECAST.
&&
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...LARGE RAIN SHIELD
OVERSPREADING THE REGION AS ABUNDANT MOISTURE IS IN PLACE. BLENDED
TOTAL PRECIPITABLE WATER SATELLITE IMAGERY INDICATES 1-1.5 INCHES
ACROSS MAINLY LOCATIONS ALONG AND SOUTH OF I-20. THIS IS GENERALLY
120-180 PERCENT OF NORMAL. THIS HAS LED TO SEVERAL FLASH FLOOD
WARNINGS ACROSS THE REGION. STORM TOTAL PRECIP SINCE YESTERDAY
MORNING INDICATES THAT MANY LOCATIONS GENERALLY ALONG AND WEST OF
I-55 SHOWS RAINFALL TOTALS AROUND 3-5 INCHES. THIS ACTIVITY COMES AS
A SHORTWAVE TROUGH SLOWLY MOVES INTO THE REGION. WHILE THE PRIMARY
CONCERN IS THE FLOODING ACROSS THE REGION...SOME BETTER CONVECTIVE
CELLS HAVE EXHIBITED SOME STRONG TO SEVERE TENDENCY...ESPECIALLY
THOSE THAT ARE ENTERING A REGION THAT HAS BEEN ABLE TO WARM
UP/DESTABILIZE BETTER TODAY. EXTENSIVE CLOUD COVER AND CONTINUOUS
RAIN HAS KEPT TEMPERATURES IN THE UPPER 50S AND LOWER 60S FOR MUCH
OF THE DAY. THE FAR SOUTHEAST AND EAST HAVE BEEN ABLE TO WARM MORE
WITH LATER ONSET OF CLOUD COVER AND RAIN. THESE LOCATIONS HAVE
GOTTEN INTO THE MID TO UPPER 60S AND LOWER 70S. IT IS IN THESE AREAS
WHERE RUC ANALYSIS SHOWS SLIGHT BETTER SFC CAPE(CLOSE TO 1000 J/KG).
WHILE LOW LEVEL SHEAR IS ON THE LOW SIDE...DEEPER LAYER SHEAR IS
ABOUT 30-40KTS. THE MAIN CONCERN WITH THESE WOULD BE WIND GUSTS AS
MID LEVEL TEMPS ARE NOT TOO COLD WITH VALUES AROUND -11 TO -13C TO
SUPPORT MUCH HAIL...BUT IF ANY IT WILL BE ON THE SMALL SIDE.
AS THE SHORTWAVE TROUGH CONTINUES TO MOVE ACROSS THE REGION THIS
AFTERNOON AND THIS EVENING...THE AXIS OF RAIN WILL CONTINUE TO SHIFT
TO THE EAST. GRADUAL CLEARING WILL TAKE PLACE FROM WEST TO EAST
THROUGH THE EVENING INTO TONIGHT WITH DRIER AIR FILTERING IN BEHIND
IT ALONG WITH HIGH PRESSURE AT THE SFC. WITH THE CLEARING
SKIES...RELATIVELY LIGHT WINDS AND SATURATED SOILS...PATCHY FOG COULD
DEVELOP TONIGHT AFTER MIDNIGHT. THIS WOULD MAINLY BE FOR LOCATIONS
ALONG AND NORTHWEST OF THE NATCHEZ TRACE. DECENTLY HIGH SREF PROBS
ALSO INDICATE THIS PROBABILITY AND HAVE INCLUDED IN THE FORECAST. BY
12Z WEDNESDAY...MODEL PW VALUES ARE 0.45 INCHES ACROSS THE
DELTA...0.70 INCHES ACROSS THE JACKSON AREA AND JUST UNDER AN INCH IN
THE PINE BELT. THIS WILL ALLOW FOR A RATHER PLEASANT DAY WEDNESDAY.
SUNNY SKIES...A GOOD NORTH WIND AND DRIER AIR WILL BE IN PLACE.
TEMPERATURES WILL START OUT CHILLY IN THE MORNING WITH READINGS IN
THE UPPER 40S IN THE DELTA...TO THE MID/UPPER 50S IN THE PINE
BELT(WHERE CLOUDS AND RAIN WILL BE SLOWER TO DEPART OVERNIGHT).
AFTERNOON HIGHS WILL REACH INTO THE MID 70S WEDNESDAY.
SFC HIGH PRESSURE CENTERED ACROSS THE MID-ATLANTIC STATES CONTINUES
TO BE BETTER ESTABLISHED ACROSS THE AREA THROUGH THURSDAY WITH
GENERALLY ZONAL FLOW ALOFT. THIS WILL LEAD TO DRY
CONDITIONS...MOSTLY SUNNY SKIES...COOL OVERNIGHT LOWS DUE TO GOOD
RADIATIONAL COOLING CONDITIONS AND COOLER AFTERNOON HIGHS. BY
THURSDAY NIGHT...THE SFC HIGH WILL BE SHIFTING FURTHER
EAST...BRINGING THE REGION UNDER THE WESTERN PERIPHERY AND SOUTHERLY
WINDS WILL RETURN. MOISTURE WILL INCREASE AHEAD OF A DEVELOPING LOW
PRESSURE SYSTEM LOCATED ACROSS THE TEXAS PANHANDLE/RED RIVER VALLEY
AT 12Z FRIDAY. WITH THE INCREASE IN MOISTURE...OVERNIGHT LOWS ON
THURSDAY WILL BE HIGHER AND INTO THE LOWER 50S. /28/
.LONG TERM...FRIDAY THROUGH TUESDAY...MAIN FOCUS IN THE MEDIUM RANGE
WILL BE ON A DIGGING SHORTWAVE INTO THE DEEP SOUTH THAT BOTH GFS AND
ECMWF MODELS NOW ARE CLOSING OFF A 500MB(560DM) LOW CENTER NEAR THE
MS COAST FOR SATURDAY NIGHT AND THEN MOVING IT SLOWLY EWD.
MEANWHILE...A FLAT MID LEVEL RIDGE ALOFT SHOULD HOLD A DRY WNW ZONAL
FLOW IN PLACE THURSDAY THAT BACKS WITH WEAK LOW LEVEL WARM ADVECTION
DEVELOPING THURSDAY NIGHT AND FRIDAY. EXPECT LOW LEVEL FRONTOGENESIS
FROM THE MID SOUTH TO THE ARKLATEX FRIDAY NIGHT WITH INCREASING
RAIN/TSRA CHANCES FOR OUR AREA FRIDAY AFTERNOON RIGHT THROUGH
SATURDAY EVENING.
THE SLOWER PROGRESSION OF THIS SYSTEM WILL RESULT IN HIGHER QPF
AMOUNTS THAT WOULD NOW APPEAR TO BE AROUND 2 INCHES WITH LOCALLY
HIGHER 3 TO 4 INCHES POSSIBLE IN SERN MS BY EARLY SUNDAY. A WIDER
RIBBON OF 1.4 INCH PWATS AND 7-500MB LAPSE RATES OF 6.5C SUPPORT
SCATTERED TSRA ALONG THE SLOWING FRONT FRIDAY NIGHT WITH SURFACE
CYCLOGENESIS(1003MB) IN THE KMSY VICINITY EARLY SATURDAY. THE FRONT
PLODS EWD INTO THE I-59 CORRIDOR LATER ON SATURDAY WITH AN UPPER
DEFORMATION ZONE LOCKING IN THE WRAP AROUND MOISTURE BEING FORCED
NWWD ON STRENGTHENING ELY LOW LEVEL FLOW THROUGH THE GULF STATES. WE
COULD BE IN FOR A REAL SOAKER AS PATTERN TAKING ON MORE OF AN EL NINO
LOOK LATELY.
WE FINALLY BEGIN DRYING OUT EARLY SUNDAY FOLLOWED BY A NOTICEABLY
COOLER AIRMASS FOR THE START OF NEXT WEEK AS OVERNIGHT LOWS LIKELY TO
DIP INTO THE 40S EARLY SUNDAY AND MONDAY MORNINGS. OUR HIGHS STAY
WELL BELOW NORMAL IN THE 65-72F RANGE SUNDAY BEFORE A WARMING TREND
ARRIVES MONDAY AND TUESDAY. HAVE LEANED TOWARD THE ENSEMBLE MEANS
FOR MAXES OVER THE WEEKEND AS LONGER DAYLIGHT HOURS TEND TO MODERATE
THESE AIR MASSES EFFECTIVELY. 500MB HEIGHT RISES OF 40-60M SUNDAY AND
AGAIN ON MONDAY ALLOW LOW LEVEL WAA TO PUSH DAYTIME READINGS UPWARD
AND THESE SHOULD BE VERY CLOSE TO THE NORMALS FOR THIS TIME IN APRIL
WITH LOWS IN THE BACK INTO THE 50S AND HIGHS 75-80F BY TUESDAY./40/
&&
.AVIATION...WE WILL SEE IMPROVING CONDITIONS FROM WEST TO EAST WITH
VFR CONDITIONS DEVELOPING FROM THE EVENING INTO THE OVERNIGHT HOURS.
MVFR/IFR CATEGORY STRATUS WILL DEVELOP OVER EASTERN MS
(GTR/MEI/HBG)...AND WITH THE CLEARING SKIES AND DECREASING WIND
FARTHER WEST...AREAS OF FOG WILL DEVELOP AFTER 06Z AND PERSIST
DURING THE MORNING HOURS. ANY FOG/STRATUS WILL MIX OUT BY AROUND 15Z
WEDNESDAY MORNING AND VFR CONDITIONS CAN BE EXPECTED THROUGH
WEDNESDAY AFTERNOON/EVENING. /EC/03
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
28/40/EC/03
AREA FORECAST DISCUSSION
NWS JACKSON MS
720 PM CDT TUE APR 17 2012
.UPDATE...THE BACK EDGE OF THE RAIN SHIELD CONTINUES TO SLOWLY SHIFT
TO THE EAST THIS EVENING AND GUSTY WINDS HAVE BEGUN TO SUBSIDE.
UPDATED THE FORECAST TO SIGNIFICANTLY LOWER POPS GENERALLY I-55 WWD
FOR THIS EVENING. ALSO LOWERED TEMPS A LITTLE IN THE SE WHERE THE
RAIN/CLOUD SHIELD HAS RESULTED IN SLIGHTLY LOWER TEMPS THAN
ANTICIPATED. RAIN CHANCES WILL CONTINUE TO DECREASE FROM THE WEST
THIS EVENING. HAVE HELD ONTO HIGHER POPS FARTHER EAST THROUGH
MIDNIGHT AS HIGHER RES MODELS INDICATE A POSSIBLE SECOND WAVE OF
LIGHT PCPN INTO SE/SCNTRL ZONES LATER THIS EVENING.
&&
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...LARGE RAIN SHIELD
OVERSPREADING THE REGION AS ABUNDANT MOISTURE IS IN PLACE. BLENDED
TOTAL PRECIPITABLE WATER SATELLITE IMAGERY INDICATES 1-1.5 INCHES
ACROSS MAINLY LOCATIONS ALONG AND SOUTH OF I-20. THIS IS GENERALLY
120-180 PERCENT OF NORMAL. THIS HAS LED TO SEVERAL FLASH FLOOD
WARNINGS ACROSS THE REGION. STORM TOTAL PRECIP SINCE YESTERDAY
MORNING INDICATES THAT MANY LOCATIONS GENERALLY ALONG AND WEST OF
I-55 SHOWS RAINFALL TOTALS AROUND 3-5 INCHES. THIS ACTIVITY COMES AS
A SHORTWAVE TROUGH SLOWLY MOVES INTO THE REGION. WHILE THE PRIMARY
CONCERN IS THE FLOODING ACROSS THE REGION...SOME BETTER CONVECTIVE
CELLS HAVE EXHIBITED SOME STRONG TO SEVERE TENDENCY...ESPECIALLY
THOSE THAT ARE ENTERING A REGION THAT HAS BEEN ABLE TO WARM
UP/DESTABILIZE BETTER TODAY. EXTENSIVE CLOUD COVER AND CONTINUOUS
RAIN HAS KEPT TEMPERATURES IN THE UPPER 50S AND LOWER 60S FOR MUCH
OF THE DAY. THE FAR SOUTHEAST AND EAST HAVE BEEN ABLE TO WARM MORE
WITH LATER ONSET OF CLOUD COVER AND RAIN. THESE LOCATIONS HAVE
GOTTEN INTO THE MID TO UPPER 60S AND LOWER 70S. IT IS IN THESE AREAS
WHERE RUC ANALYSIS SHOWS SLIGHT BETTER SFC CAPE(CLOSE TO 1000 J/KG).
WHILE LOW LEVEL SHEAR IS ON THE LOW SIDE...DEEPER LAYER SHEAR IS
ABOUT 30-40KTS. THE MAIN CONCERN WITH THESE WOULD BE WIND GUSTS AS
MID LEVEL TEMPS ARE NOT TOO COLD WITH VALUES AROUND -11 TO -13C TO
SUPPORT MUCH HAIL...BUT IF ANY IT WILL BE ON THE SMALL SIDE.
AS THE SHORTWAVE TROUGH CONTINUES TO MOVE ACROSS THE REGION THIS
AFTERNOON AND THIS EVENING...THE AXIS OF RAIN WILL CONTINUE TO SHIFT
TO THE EAST. GRADUAL CLEARING WILL TAKE PLACE FROM WEST TO EAST
THROUGH THE EVENING INTO TONIGHT WITH DRIER AIR FILTERING IN BEHIND
IT ALONG WITH HIGH PRESSURE AT THE SFC. WITH THE CLEARING
SKIES...RELATIVELY LIGHT WINDS AND SATURATED SOILS...PATCHY FOG COULD
DEVELOP TONIGHT AFTER MIDNIGHT. THIS WOULD MAINLY BE FOR LOCATIONS
ALONG AND NORTHWEST OF THE NATCHEZ TRACE. DECENTLY HIGH SREF PROBS
ALSO INDICATE THIS PROBABILITY AND HAVE INCLUDED IN THE FORECAST. BY
12Z WEDNESDAY...MODEL PW VALUES ARE 0.45 INCHES ACROSS THE
DELTA...0.70 INCHES ACROSS THE JACKSON AREA AND JUST UNDER AN INCH IN
THE PINE BELT. THIS WILL ALLOW FOR A RATHER PLEASANT DAY WEDNESDAY.
SUNNY SKIES...A GOOD NORTH WIND AND DRIER AIR WILL BE IN PLACE.
TEMPERATURES WILL START OUT CHILLY IN THE MORNING WITH READINGS IN
THE UPPER 40S IN THE DELTA...TO THE MID/UPPER 50S IN THE PINE
BELT(WHERE CLOUDS AND RAIN WILL BE SLOWER TO DEPART OVERNIGHT).
AFTERNOON HIGHS WILL REACH INTO THE MID 70S WEDNESDAY.
SFC HIGH PRESSURE CENTERED ACROSS THE MID-ATLANTIC STATES CONTINUES
TO BE BETTER ESTABLISHED ACROSS THE AREA THROUGH THURSDAY WITH
GENERALLY ZONAL FLOW ALOFT. THIS WILL LEAD TO DRY
CONDITIONS...MOSTLY SUNNY SKIES...COOL OVERNIGHT LOWS DUE TO GOOD
RADIATIONAL COOLING CONDITIONS AND COOLER AFTERNOON HIGHS. BY
THURSDAY NIGHT...THE SFC HIGH WILL BE SHIFTING FURTHER
EAST...BRINGING THE REGION UNDER THE WESTERN PERIPHERY AND SOUTHERLY
WINDS WILL RETURN. MOISTURE WILL INCREASE AHEAD OF A DEVELOPING LOW
PRESSURE SYSTEM LOCATED ACROSS THE TEXAS PANHANDLE/RED RIVER VALLEY
AT 12Z FRIDAY. WITH THE INCREASE IN MOISTURE...OVERNIGHT LOWS ON
THURSDAY WILL BE HIGHER AND INTO THE LOWER 50S. /28/
.LONG TERM...FRIDAY THROUGH TUESDAY...MAIN FOCUS IN THE MEDIUM RANGE
WILL BE ON A DIGGING SHORTWAVE INTO THE DEEP SOUTH THAT BOTH GFS AND
ECMWF MODELS NOW ARE CLOSING OFF A 500MB(560DM) LOW CENTER NEAR THE
MS COAST FOR SATURDAY NIGHT AND THEN MOVING IT SLOWLY EWD.
MEANWHILE...A FLAT MID LEVEL RIDGE ALOFT SHOULD HOLD A DRY WNW ZONAL
FLOW IN PLACE THURSDAY THAT BACKS WITH WEAK LOW LEVEL WARM ADVECTION
DEVELOPING THURSDAY NIGHT AND FRIDAY. EXPECT LOW LEVEL FRONTOGENESIS
FROM THE MID SOUTH TO THE ARKLATEX FRIDAY NIGHT WITH INCREASING
RAIN/TSRA CHANCES FOR OUR AREA FRIDAY AFTERNOON RIGHT THROUGH
SATURDAY EVENING.
THE SLOWER PROGRESSION OF THIS SYSTEM WILL RESULT IN HIGHER QPF
AMOUNTS THAT WOULD NOW APPEAR TO BE AROUND 2 INCHES WITH LOCALLY
HIGHER 3 TO 4 INCHES POSSIBLE IN SERN MS BY EARLY SUNDAY. A WIDER
RIBBON OF 1.4 INCH PWATS AND 7-500MB LAPSE RATES OF 6.5C SUPPORT
SCATTERED TSRA ALONG THE SLOWING FRONT FRIDAY NIGHT WITH SURFACE
CYCLOGENESIS(1003MB) IN THE KMSY VICINITY EARLY SATURDAY. THE FRONT
PLODS EWD INTO THE I-59 CORRIDOR LATER ON SATURDAY WITH AN UPPER
DEFORMATION ZONE LOCKING IN THE WRAP AROUND MOISTURE BEING FORCED
NWWD ON STRENGTHENING ELY LOW LEVEL FLOW THROUGH THE GULF STATES. WE
COULD BE IN FOR A REAL SOAKER AS PATTERN TAKING ON MORE OF AN EL NINO
LOOK LATELY.
WE FINALLY BEGIN DRYING OUT EARLY SUNDAY FOLLOWED BY A NOTICEABLY
COOLER AIRMASS FOR THE START OF NEXT WEEK AS OVERNIGHT LOWS LIKELY TO
DIP INTO THE 40S EARLY SUNDAY AND MONDAY MORNINGS. OUR HIGHS STAY
WELL BELOW NORMAL IN THE 65-72F RANGE SUNDAY BEFORE A WARMING TREND
ARRIVES MONDAY AND TUESDAY. HAVE LEANED TOWARD THE ENSEMBLE MEANS
FOR MAXES OVER THE WEEKEND AS LONGER DAYLIGHT HOURS TEND TO MODERATE
THESE AIR MASSES EFFECTIVELY. 500MB HEIGHT RISES OF 40-60M SUNDAY AND
AGAIN ON MONDAY ALLOW LOW LEVEL WAA TO PUSH DAYTIME READINGS UPWARD
AND THESE SHOULD BE VERY CLOSE TO THE NORMALS FOR THIS TIME IN APRIL
WITH LOWS IN THE BACK INTO THE 50S AND HIGHS 75-80F BY TUESDAY./40/
&&
.AVIATION...WE WILL SEE IMPROVING CONDITIONS FROM WEST TO EAST WITH
VFR CONDITIONS DEVELOPING FROM THE EVENING INTO THE OVERNIGHT
HOURS...ESPECIALLY AT GLH/GWO/JAN/HBG. IFR CATEGORY STRATUS MAY BE
GENERATED OVER EASTERN MS (GTR/MEI) IN THE WEAK COLD ADVECTION
PATTERN...AND WITH THE CLEARING SKIES AND DECREASING WIND FARTHER
WEST...AREAS OF FOG MAY DEVELOP AFTER 06Z AND PERSIST DURING THE
MORNING HOURS. ANY FOG/STRATUS WILL MIX OUT BY AROUND 15Z WEDNESDAY
MORNING AND VFR CONDITIONS CAN BE EXPECTED THROUGH WEDNESDAY
AFTERNOON/EVENING. /EC/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
28/40/EC
AREA FORECAST DISCUSSION
NWS BILLINGS MT
253 AM MDT MON APR 16 2012
.SHORT TERM...VALID FOR TDY AND TUE...
RADAR ECHOES HAVE WEAKENED THROUGH THE NIGHT OVER THE BEARTOOTH
AND RED LODGE FOOTHILLS SO WILL CANCEL THE SNOW ADVISORY.
WILL ADD PATCHY FOG THROUGH 15Z TO AREAS THAT RECEIVED
PRECIPITATION YESTERDAY...AS TEMPERATURE/DEW POINT SPREADS WERE
CLOSE EARLY THIS MORNING. HAVE DRIED OUT SE MT THIS MORNING.
BOWMAN RADAR SHOWED NO PRECIPITATION OVER THIS AREA...AND THE
SHORTWAVE IN THE SE WAS MOVING QUICKLY OUT OF THE AREA PER WATER
VAPOR IMAGERY AND RUC DATA. ALSO CONFINED PRECIPITATION CHANCES TO
THE HIGH WESTERN ELEVATIONS OF THE NE BIG HORNS WITH NO RADAR
ECHOES OVER THE AREA AND GFS TIME-HEIGHTS SHOWING FAIRLY HIGH
LEVEL MOISTURE. ALSO CONFINED POPS OVER THE BEARTOOTHS AND
ABSAROKAS TO W-FACING SLOPES FOR SIMILAR REASONS. MODEL CONSENSUS
SUPPORTED ONLY LOW POPS FOR THE WESTERN MOUNTAINS THIS AFTERNOON.
MADE ONLY SLIGHT TEMPERATURE ADJUSTMENTS. EXPECT THE LOW CLOUDS TO
BURN OFF THIS MORNING WITH DAYTIME HEATING.
A PACIFIC SHORTWAVE...SEEN BETWEEN 130 AND 140W ON WATER VAPOR
IMAGERY OFF THE PACIFIC NW COAST...WILL APPROACH THE AREA TONIGHT
BRINGING AN INCREASE IN MOISTURE TO THE WESTERN MOUNTAINS. THE WAVE
WILL PUSH A WARM FRONT THROUGH THE AREA WITH LIMITED MOISTURE. NOTED
THE GFS HAD A SOUTHERN PIECE OF ENERGY MOVING INTO N WY AS
WELL...BUT LOW TO MID LEVEL MOISTURE WAS LIMITED WITH THIS FEATURE
SO WILL NOT ADD ANY POPS TO SHERIDAN COUNTY. THE GOING WESTERN
MOUNTAINS POPS AND SLIGHT CHANCE IN KLVM WERE IN GOOD SHAPE.
AS THE WAVE MOVES ACROSS THE AREA ON TUE IT WILL BE ACCOMPANIED BY
FAIRLY STRONG Q-VECTOR CONVERGENCE. IN ADDITION...BOTH THE WRF AND
GFS SHOWED STEEP 850-700 MB LAPSE RATES. SO THE GOING CHANCE OF
SHOWERS SEEMED FINE AS THE ABOVE FACTORS SHOULD OVERCOME THE
DOWNSLOPE FLOW. LOWERED HIGHS ON TUE BASED ON MIXING PROFILES AND
PARTLY CLOUDY SKIES.
THE SHORTWAVE WILL EXIT THE AREA TUE NIGHT. KEPT SOME POPS OVER
AND NEAR THE SOUTHERN MOUNTAINS TUE EVENING BASED ON THE LOCATION
OF THE MOISTURE. ANOTHER WAVE WILL APPROACH THE AREA LATE TUE
NIGHT IN THE PROGRESSIVE FLOW ALOFT BRINGING A GOOD CHANCE OF
PRECIPITATION TO THE BEARTOOTHS AND ABSAROKAS...WITH LESSER
CHANCES OVER THE ADJACENT FOOTHILLS AND NE BIG HORNS. RAISED MIN
TEMPERATURES A LITTLE BASED ON CLOUD COVER AND EXPECTED 850 MB
TEMPERATURES. ARTHUR
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
A STREAM OF ENERGY WILL KEEP SHORTWAVE TROUGHINESS OVER THE AREA
WEDNESDAY AND WEDNESDAY NIGHT BEFORE A SURGE OF HEIGHTS OVER THE
PACIFIC NORTHWEST BEGINS A WARMING TREND ON THURSDAY. WHILE THE
TROFFING ON WEDNESDAY IS NOT TOO DEEP IT DOES APPEAR TO BE
SUFFICIENT TO GENERATE SURFACE PRESSURE FALLS OVER WYOMING AND
SOUTH DAKOTA. THIS BRINGS UPSLOPISH FLOW AND WITH AIRMASS UNSTABLE
SHOULD SUPPORT SHOWER ACTIVITY...WITH BEST CHANCES FOR MOISTURE
OVER THE SOUTHERN ZONES. CLOUD COVER AND SHOWER ACTIVITY SHOULD
MAKE WEDNESDAY THE COOLEST DAY OF THE EXTENDED PERIOD.
AS HEIGHTS BUILD OVER WESTERN MONTANA ON THURSDAY IT SHIFTS THE
TROUGH AXIS TO THE MONTANA DAKOTA BORDER AND THUS THE
PRECIPITATION CHANCES WANE FOR THE WESTERN ZONES...ESPECIALLY
THURSDAY NIGHT. THEY PERSIST FOR THE EASTERN ZONES AS PERSISTENT
CONVERGENCE SUPPORTS A BETTER CHANCE FOR MOISTURE. THURSDAY NIGHT
IS A PERIOD OF LOW CONFIDENCE AS THE MODEL RUNS ARE ALTERNATING
BETWEEN SHOWING A STRONGER WAVE MOVING DOWN IN DEVELOPING
NORTHWEST FLOW VERSUS PUSHING THE TROUGH A BIT FURTHER EAST.
EXCEPT FOR THE EAST...EXPECT DECREASING CLOUD COVER TO SUPPORT
WARMER TEMPERATURES.
FRIDAY AND BEYOND RIDGE BUILDS INTO THE REGION WITH A STRONG
WARMING TREND. RIDGE LOOKS SUFFICIENTLY STRONG TO SUPPRESS
CONVECTION OVER THE LOWER ELEVATIONS THOUGH THETA E VALUES DO
INCREASE AS THE RIDGE BUILDS. TEMPERATURES WILL CLIMB INTO THE 70S
FOR THE WEEKEND. BORSUM
&&
.AVIATION...
AREAS OF FOG AND STRATUS WILL PERSIST UNTIL AFTER SUNRISE WEST AND
SOUTH OF AND INCLUDING KBIL. EXPECT QUICKLY IMPROVING CONDITIONS
THROUGH THE MID MORNING HOURS. MOST LOCATIONS WILL REMAIN DRY
THROUGH THE REST OF THE DAY THOUGH SOME MOUNTAIN SHOWERS WILL FORM
INVOF KLVM. BORSUM
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 059 040/059 036/056 040/061 036/067 042/070 045/074
1/E 14/W 13/W 33/W 22/W 21/B 11/B
LVM 054 036/054 034/052 035/056 032/063 038/067 042/072
1/N 24/W 24/W 43/T 33/W 32/W 21/B
HDN 059 037/062 033/058 035/064 036/069 040/073 041/077
1/E 14/W 13/W 33/W 32/W 21/B 11/B
MLS 055 038/063 032/059 035/060 038/066 042/074 043/077
1/B 14/W 12/W 34/W 32/W 21/B 11/U
4BQ 054 035/062 031/058 034/059 037/066 040/074 040/077
1/B 13/W 04/W 34/W 32/W 21/B 10/U
BHK 052 033/061 031/056 034/057 035/062 038/071 038/073
1/E 14/W 22/W 44/W 32/W 21/N 11/B
SHR 055 034/058 032/056 034/059 036/066 041/074 042/077
1/B 13/W 33/W 33/W 32/W 21/B 10/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1040 AM EDT MON APR 16 2012
.SYNOPSIS...
STRONG SOUTHWEST WINDS TODAY WILL BRING SUMMERLIKE TEMPERATURES TO
THE REGION BEFORE A STRONG COLD FRONT SWEEPS ACROSS THE AREA DURING
THE AFTERNOON AND EVENING. THE FRONT WILL BRING THUNDERSTORMS
SOME OF WHICH MAY BECOME SEVERE. TEMPERATURES WILL THEN RETURN TO
NEAR AVERAGE FOR THE REST OF THE WEEK WITH THE NEXT CHANCE OF RAIN
ARRIVING ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST SURFACE MAP SHOWS LOW PRESSURE LOCATED OVER NORTH CENTRAL
WISCONSIN WITH THE COLD FRONT TRAILING SOUTH ACROSS LAKE MICHIGAN
AND WESTERN INDIANA. THE NARROW BAND OF SHOWERS AND ISOLATED
THUNDERSTORMS FORMING WELL AHEAD OF THE FRONT SHOULD EXPAND A BIT
MORE DURING THE AFTERNOON AS IT ENCOUNTERS DEEPER MOISTURE OVER THE
OHIO VALLEY AND LOWER GREAT LAKES. EXPECT THIS CONVECTION TO REACH
WESTERN NEW YORK A LITTLE AFTER 18Z...THEN SPREAD EAST ACROSS THE
REST OF THE CWA DURING THE REST OF THE AFTERNOON AND EVENING. THE
MAIN QUESTION IS HOW INTENSE WILL THE CONVECTION GET. CERTAINLY THE
UNIDIRECTIONAL SHEAR PROFILES ARE FAVORABLE FOR STRONG WIND GUSTS...BUT
THERE IS STILL SOME QUESTION ABOUT INSTABILITY...ESPECIALLY IN THE
WEST WHERE CLOUDS FROM THE UPSTREAM CONVECTION WILL BE ARRIVING
SOONER. THE LATEST RUC AND NAM12 STABILITY INDICES SHOW MORE
FAVORABLE CAPES (AVERAGING AROUND 1000-1500 J/KG) DEVELOPING
ACROSS THE GENESEE VALLEY AND FINGER LAKES AREA LATER THIS
AFTERNOON. THEREFORE...IT STILL LOOKS LIKE THE POTENTIAL FOR
DAMAGING THUNDERSTORM WIND GUSTS WILL BE GREATEST ACROSS THIS
AREA. KEEP IN MIND THOUGH...THAT CONVECTION THAT IMPACTS ANY PART
OF THE CWA WILL HAVE THE POTENTIAL TO TRANSPORT HIGHER WINDS ALOFT
DOWN TO THE SURFACE...AND CONVECTIVE CELLS WILL LIKELY BE MOVING
AT A PRETTY GOOD CLIP. WITH WARM TEMPS ALOFT...AND SOMEWHAT
QUESTIONABLY INSTABILITY... HAIL SHOULD BE A LESSER SECONDARY
RISK.
OTHERWISE...THE DEEP LAYERED SOUTHERLY FLOW AHEAD OF THE APPROACHING
FRONT WILL RESULT IN SUMMER-LIKE TEMPERATURES ACROSS THE AREA THIS
AFTERNOON. MANY AREAS WILL MAKE IT INTO THE LOW OR MID 80S WITH THE
WARMEST SPOTS LIKELY FROM THE GENESEE VALLEY INTO CENTRAL NY.
STRONG SYNOPTIC SCALE WINDS WILL ALSO BE A CONCERN LATER THIS
MORNING AND DURING THE AFTERNOON AS THE CORE OF A 50 TO 60 KNOT LOW
LEVEL JET TRACKS JUST TO OUR NORTHWEST. DAYTIME HEATING WILL PROMOTE
DEEP MIXING THROUGH THE BOUNDARY LAYER WITH STRONGER WINDS FROM
ALOFT MAKING IT DOWN TO THE SURFACE. BUFKIT MOMENTUM TRANSFER
SCHEMES SUGGEST GUSTS OF 40-45 KNOTS POSSIBLE FROM NEAR THE LAKE
ERIE SHORE NORTHEAST ACROSS THE NIAGARA FRONTIER TO NEAR ROCHESTER.
THEREFORE...A WIND ADVISORY REMAINS IN EFFECT FOR WESTERN NEW YORK
THROUGH 7PM.
TONIGHT...THE FRONT LOOKS TO STILL BE PUSHING ACROSS THE FAR EASTERN
FORECAST AREA WITH SHOWERS AND THUNDERSTORMS INTO THE EVENING. THE
FRONT WILL BE COMPLETELY EAST OF THE STATE BY MIDNIGHT. WINDS WILL
CONTINUE TO GUST BEHIND THE FRONT AS COLDER AND DRIER AIR FILTERS
IN. LOW TEMPERATURES WILL FALL INTO THE MID TO LOWER 40S WITH
CLEARING SKIES AND HIGH PRESSURE RIDGING IN FROM THE UPPER LAKES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
SURFACE HIGH PRESSURE BEGINS TO BUILD INTO THE REGION AT THE
START OF THE PERIOD. SOME LEFTOVER LOW LEVEL MOISTURE COMBINED
WITH COLD AIR ADVECTION AND UPPER SHORT WAVE LIFTING ACROSS
THE REGION WILL RESULT IN A MODEST AMOUNT OF CLOUDINESS ON
TUESDAY...BUT SEE LITTLE IN THE WAY TO TRIGGER PRECIPITATION.
TUESDAY WILL BE A SHARPLY COOLER DAY THAN MONDAY WITH HIGHS SOME
20 TO 30 DEGREES COLDER THAN MONDAY`S HIGHS...MAINLY IN THE UPPER
40S TO LOWER 50S.
THE HIGH SETTLES OVER THE AREA TUESDAY NIGHT. CLEAR SKIES AND
LIGHT WINDS WILL BRING FROST/FREEZE CONCERNS AS OVERNIGHT LOWS
DROP INTO THE MID 20S TO LOWER 30S.
HIGH PRESSURE CONTINUES TO HOLD IN FIRM ACROSS THE AREA FOR
WEDNESDAY...PROVIDING A FAIR WEATHER DAY. AIR MASS LOOK
TO MODERATE WITH TEMPERATURES WARMING BACKING MID TO UPPER
50S...WITH A FEW LOWER 60S POSSIBLE.
CLOUDS WILL BE ON THE INCREASE EARLY WEDNESDAY NIGHT A RATHER
MODEST NORTHERN STREAM SHORTWAVE MOVES ALONG THE U.S./CANADIAN
BORDER...DRAGGING A COLD FRONT TOWARD WESTERN NEW YORK. AN
INCREASING LOW LEVEL JET AHEAD OFF THE FRONT SHOULD BE ABLE TO
PULL SUFFICIENT MOISTURE NORTHWARD AND INTERACT WITH THE
APPROACHING FRONT TO INCREASE THE PRECIPITATION THREAT OVERNIGHT
AND TOWARDS THURSDAY MORNING. THERE IS SOME MINOR FROZEN
PRECIPITATION POTENTIAL ACROSS PORTIONS OF THE SOUTHERN TIER AND
NORTH COUNTRY...BUT WARM AIR ADVECTION SHOULD ADVECT ABOVE
FREEZING DEWPOINTS INTO THESE AREAS BY THURSDAY MORNING...
THEREFORE IF ANY SNOW OR MIX OCCURS IT WILL BE VERY SHORT LIVED.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A ZONAL FLOW WILL CONTINUE ACROSS NORTH AMERICA THIS TIME
PERIOD...THOUGH A LONGWAVE RIDGE WILL BUILD OVER THE WESTERN
US...WITH A CORRESPONDING TROUGH OVER THE CENTRAL PLAINS.
TEMPERATURES AROUND/FEW DEGREES ABOVE NORMAL TO START THE
PERIOD...AND COOLING DOWN WITH THE FALLING HEIGHTS ALOFT FOR THE
WEEKEND. A FRONTAL BOUNDARY LOOKS TO CROSS THE REGION ON THURSDAY
WITH RAIN SHOWERS...AND THEN INCREASING CHCS FOR PRECIPITATION LATER
OVER THE WEEKEND AS THE TROUGH NEARS THE REGION. FOR THE DETAILS...
ON THURSDAY BOTH THE 12Z GFS AND ECMWF CONTINUE TO PUSH A FRONTAL
BOUNDARY ACROSS THE REGION. CONSIDERING THE ZONAL FLOW AND MODEL
CONTINUITY CHANCES ARE INCREASING FOR RAIN SHOWERS ON THURSDAY. A
EMBEDDED SHORTWAVE WITHIN THE MEAN FLOW WILL CROSS THE REGION ALONG
WITH THE 12Z GFS BRINGING THE LEFT EXIT REGION OF A 90KNOT 250 HPA
JET ACROSS THE REGION...WITH BOTH FEATURES ADDING TO THE LARGE SCALE
LIFT...AND WE WILL INCREASE POPS TO MID/HIGH CHCS THURSDAY THOUGH
QPF LOOKS TO REMAIN LIGHT.
WITH THE FRONTAL BOUNDARY PUSHING TO THE SOUTH AND EAST OF THE
REGION THURSDAY NIGHT WILL CONTINUE WITH SLIGHT CHC POPS WITH CLOUDY
SKIES SLOWLY CLEARING OVERNIGHT.
FRIDAY AND SATURDAY BOTH THE ECMWF AND GFS DEVELOP A STORM SYSTEM
ACROSS THE SOUTHERN PLAINS UNDER THE LARGE SCALE TROUGH OVER THE
PLAINS. BOTH MODEL SOLUTIONS...ALONG WITH THE MAJORITY OF THE 00Z
GEFS TAKE THIS SYNOPTIC LOW JUST TO OUR SOUTH AND EAST LEAVING THE
EASTERN GREAT LAKES ON THE COOL SIDE WITH RAIN SHOWERS. WILL
INCREASE POPS THROUGH THE DAY FRIDAY...THOUGH AT THIS TIME THE BEST
CHCS MIGHT BE LATER FRIDAY AND THROUGH SATURDAY.
AS THIS SYSTEM PULLS TO THE EAST LATER IN THE WEEKEND BOTH THE ECMWF
AND GFS DROP 850 HPA TEMPERATURES ACROSS THE REGION TO BELOW ZERO.
THE GFS IS MUCH COOLER ALOFT...DUE IN PART TO THE DEEPER LOW ACROSS
NEW ENGLAND PULLING THE COLD AIR SOUTHWARD. STILL GIVEN THE TRACK/
AND SUPPORT FROM THE GEFS PRECIPITATION CANNOT RULE OUT SOME LIGHT
SNOW SATURDAY NIGHT OR SUNDAY ESPECIALLY OVER HIGHER TERRAIN. FOR
NOW WILL GO JUST SLIGHT CHC FOR SNOW IN THE GRIDS AS THE TRACK AND
DEPTH OF THE SYNOPTIC LOW THIS FAR OUT CAN CHANGE QUITE A BIT. WITH
BOTH 12Z RUNS OF THE GFS AND ECMWF DISPLAYING AN UPPER LEVEL TROUGH
OVER THE REGION WILL UNDERCUT HIGHS BY SEVERAL DEGREES FROM MODEL
GUIDANCE AND HAVE HIGHS IN THE 40S ACROSS THE REGION.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ACROSS THE AREA THIS MORNING POSSIBLY LOWERING TO
MVFR THIS AFTERNOON IN THUNDERSTORMS. STRONG WINDS WILL PICKUP THIS
MORNING AS A 50 KT LOW LEVEL JET SETS UP OVER THE AREA BRINGING
SURFACE WIND GUSTS OF 30-45 KNOTS. THE STRONGEST WINDS EXPECTED
ACROSS WESTERN NY FROM LAKE ERIE NORTHEAST ACROSS KBUF-KIAG-KROC. A
COLD FRONT WILL SLIDE ACROSS THE STATE DURING THE LATE AFTERNOON
WITH A LINE OF FAST MOVING THUNDERSTORMS. THESE STORMS HAVE THE
POTENTIAL TO TAP INTO THE STRONGER WINDS ALOFT AND PRODUCE SPORADIC
SURFACE WIND GUSTS TO 50 KTS. THE FRONT WILL MOVE EAST OF THE AREA
TONIGHT BUT WINDS WILL STAY GUSTY THROUGH THE EVENING AS COLDER AND
DRIER AIR FILTERS IN.
OUTLOOK...
MONDAY NIGHT...SHOWERS AND THUNDERSTORMS ENDING.
TUESDAY...VFR/MVFR CIGS.
WEDNESDAY...VFR.
THURSDAY AND FRIDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
SOUTH-SOUTHWEST WINDS WILL INCREASE TODAY WITH A MODERATE TO STRONG
PRESSURE GRADIENT DEVELOPING AHEAD OF A LOW MOVING INTO THE UPPER
GREAT LAKES. THIS WILL PRODUCE SMALL CRAFT ADVISORY CONDITIONS ON
LAKE ERIE AND THE WEST HALF OF LAKE ONTARIO. A STRONG COLD FRONT
WILL CROSS THE REGION THIS EVENING...WITH WINDS BECOMING WESTERLY
AND INCREASING LATER TONIGHT INTO TUESDAY WITH ANOTHER ROUND OF
SMALL CRAFT ADVISORY CONDITIONS ON BOTH LAKES ERIE AND ONTARIO.
WINDS WILL DIMINISH TUESDAY NIGHT AND WEDNESDAY AS HIGH PRESSURE
BUILDS INTO THE LOWER LAKES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WIND ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NYZ001>003-
010>012-019-020-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ020.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT TUESDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LOZ030-042-043.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
SLZ022-024.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH/TJP
SHORT TERM...TMA
LONG TERM...THOMAS
AVIATION...SMITH
MARINE...SMITH/TMA
AREA FORECAST DISCUSSION
NWS RALEIGH NC
918 PM EDT TUE APR 17 2012
.SYNOPSIS...
A FRONT WILL REMAIN NEARLY STATIONARY ACROSS THE SOUTH CAROLINA
BORDER THIS EVENING...BEFORE HIGH PRESSURE BUILDING IN FROM THE
NORTH PUSHES IT FURTHER SOUTHWARD OVERNIGHT. MEANWHILE...AN UPPER
LEVEL TROUGH APPROACHING FROM THE WEST WILL BRING WIDESPREAD SHOWERS
AND COOLER WEATHER FOR WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 915 PM...
MOISTURE AND POTENTIAL ENERGY QUITE LIMITED WITH SCATTERED
CONVECTION LOW TOPPED AT THIS TIME. MOST MODELS CONTINUE TO
ATTEMPT TO DEVELOP PRECIPITATION TONIGHT ALONG THE BOUNDARY NEAR
SOUTH CAROLINA. HOWEVER THE RUC MODEL CONTINUES TO SHOW LIMITED
MOISTURE THROUGHOUT THE AIR COLUMN AND ONLY WEAK LOW LEVEL
CONVERGENCE IN THAT AREA. TO THE WEST CONVERGENCE LOCKED IN OVER
THE FOOTHILLS WITH MODELS OCCASIONALLY PRODUCING CONVERGENCE AND
LIFT IN THE WESTERN PIEDMONT. BEST CONVERGENCE WILL CONTINUE TO BE
OVER THE MOUNTAINS AND THE WESTERN FOOTHILLS TONIGHT. ISOLATED
RAINFALL AMOUNTS COULD BE IN EXCESS OF ONE INCH IN THE WEST... BUT
BASIN AVERAGES WILL GENERALLY BE QUITE LOW... AT A FEW HUNDREDTHS
OUTSIDE THE HEAVIEST SHOWERS. WILL LEAVE LOW LIKELY POPS IN THE
FAR WEST WITH CHANCE TO SLIGHT CHANCE POPS AS ONE MOVES EAST.
NORTHEAST FLOW WITH LOW LEVEL THICKNESSES AT SUNRISE WEDNESDAY
FALLING ABOUT 25 METERS FROM THIS MORNING. LOW TEMPERATURES MID
50S NORTH TO LOWER 60S SOUTH.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 250 PM TUESDAY...
ON WEDNESDAY...RAIN CHANCES WILL CONTINUE FOR THE REGION AS A
WEAKENING SHORT WAVE TROUGH MOVES ACROSS THE AREA...ALTHOUGH HOW
MUCH IS STILL IN QUESTION...ESPECIALLY ACROSS THE EASTERN PORTIONS
OF THE CWA. THE TROUGH IS FORECAST TO DEAMPLIFY THROUGHOUT THE DAY AS
IT PROGRESSES ACROSS OUR FORECAST AREA AND THEREFORE LESS FORCING IS
EXPECTED TO BE PRESENT BY THE TIME IT REACHES EASTERN NORTH
CAROLINA. ALSO... THE BEST ISENTROPIC LIFT IS FORECAST TO BE IN
PLACE ACROSS THE WESTERN PIEDMONT. IN ADDITION...A WEAK AREA OF
SURFACE HIGH PRESSURE CENTERED NEAR THE CHESAPEAKE BAY REGION WILL
RIDGE SOUTHWESTWARD INTO THE WESTERN PIEDMONT RESULTING IN A
HYBRID COLD AIR DAMMING EVENT...POSSIBLY HELPING TO ENHANCE
PRECIPITATION CHANCES ACROSS THIS REGION EVEN MORE.
THEREFORE...THE BEST PRECIPITATION CHANCES ARE EXPECTED ACROSS THE
WESTERN PIEDMONT (60-70 PERCENT) WEDNESDAY MORNING...WITH ONLY
SLIGHT CHANCE TO LOW END CHANCE ACROSS THE FAR EASTERN PORTIONS OF
THE FORECAST AREA DURING THE MORNING HOURS. AS THE TROUGH MOVES
EAST AND WEAKENS THROUGHOUT THE DAY...POPS WILL GRADUALLY DECREASE
ACROSS THE WEST AND INCREASE ACROSS THE EAST LATE IN THE DAY...
ALTHOUGH WILL GO NO HIGHER THAN HIGH END CHANCE FOR THE EAST DUE
TO THE WEAKENING TROUGH AND ITS ASSOCIATED WEAKER FORCING. AS THE
TROUGH FINALLY MOVES EAST AF THE AREA WEDNESDAY NIGHT...POPS WILL
TAPER OFF FROM WEST TO EAST THROUGH THE OVERNIGHT HOURS...WITH
JUST A LINGERING THREAT OF A MORNING SHOWER OR TWO IN THE EAST BY
THURSDAY MORNING.
HIGHS ON WEDNESDAY ARE EXPECTED TO RANGE FROM NEAR 60 DEGREES ACROSS
THE NORTHWEST TO THE LOW/MID 70S FURTHER SOUTH AND EAST. BEHIND THE
DEPARTING MID LEVEL TROUGH...OVERNIGHT LOWS ARE EXPECTED TO BE
SLIGHTLY COOLER...GENERALLY FROM NEAR 50 DEGREES ACROSS THE NORTH
AND WEST TO MID 50S FURTHER SOUTH AND EAST. -KRR
THURSDAY...SUBSIDENCE IN THE WAKE OF THE DAMPENING MID LEVEL
SHORT WAVE TROUGH SHOULD RESULT IN CLEARING SKIES THROUGH THE
MORNING...WITH PARTLY TO MOSTLY SUNNY SKIES BY THE AFTERNOON WITH
THE POTENTIAL FOR THE ZONAL FLOW ALOFT TO ADVECT SOME HIGH CLOUDS
INTO THE AREA. SURFACE RIDGE AXIS CENTERED OVER THE VIRGINIAS AND
CAROLINAS TO START THE DAY WILL GRADUALLY SLIP EAST BUT SHOULD
REMAIN OVER THE AREA THROUGH THURSDAY NIGHT. SEASONABLE AFTERNOON
HIGHS OF 70 TO 75. OVERNIGHT LOWS IN THE LOWER TO MIDDLE 50S. -CBL
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 250 PM TUESDAY...
INCREASING CONFIDENCE IN A WET WEEKEND...
THE LARGE SCALE FLOW OVER THE CONUS IS EXPECTED TO BECOME
INCREASINGLY AMPLIFIED BY THE START OF THE PERIOD WITH A PAIR OF
LONG WAVE TROUGHS WITH THE EVENTUAL DEVELOPMENT OVER THE WEST AND
EAST COASTS...AND A DAUNTING UPPER LEVEL RIDGE CENTERED OVER THE
ROCKIES.
BUT BEFORE THIS PATTERN COMES TO FRUITION...FRIDAY SHOULD REMAIN
DRY WITH BUILDING HEIGHTS ALOFT AND SOUTHERLY RETURN FLOW... IN
ADVANCE OF THE DOWNSTREAM AMPLIFYING TROUGH...BOOSTING
TEMPERATURES BACK INTO THE LOWER 80S AS LOW LEVEL THICKNESSES
CLIMB 25 TO 30 METERS ABOVE NORMAL. RAIN CHANCES WILL BEGIN TO
INCREASE LATE FRIDAY NIGHT AND EVEN MORE SO ON SATURDAY WITH
STRENGTHENING WARM MOIST AIR ADVECTION PUSHING SPREADING INTO THE
AREA AS THE AMPLIFYING TROUGH ADVANCES EASTWARD INTO THE
MISSISSIPPI VALLEY...WITH A MAJORITY OF THE DETERMINISTIC MODELS
AND ENSEMBLE MEMBERS GRAVITATING TOWARDS A CUT OFF/CLOSED UPPER
LOW OVER THE GULF COAST STATES.
MODEL SPREAD INCREASES LATE SUNDAY AND INTO MONDAY WITH UNCERTAINTY
REGARDING HOW MUCH INTERACTION BETWEEN THE NORTHERN STREAM TROUGH
AND THE SOUTHERN STREAM CUT OFF LOW...WITH EXACT DETAILS ON THE
TIMING AND TRACK DETERMINING THE SENSIBLE WEATHER IMPACTS SUNDAY
THROUGH EARLY MONDAY. BASED ON LATEST 12Z/17 MODEL ITERATIONS AND
MODEL TRENDS...APPEARS THERE WILL BE A THREAT FOR HEAVY RAIN
SUNDAY THROUGH SUNDAY NIGHT AS LARGE SCALE ASCENT OVERSPREADS THE
AREA WITH THE WAVY SURFACE FRONT AND UPPER LOW/TROUGH DYNAMICS
MOVING THROUGH THE AREA WITH WITH PRECIPITABLE WATERS APPROACHING
2 STANDARD DEVIATIONS ABOVE NORMAL(ABOUT 1.5 INCHES). THERE IS
ALSO THE POTENTIAL FOR SEVERE WEATHER DURING THE SAME TIME
FRAME...AGAIN LARGELY DEPENDENT ON THE TRACK OF THE LOW AND
WHETHER SUFFICIENT DESTABILIZATION CAN DEVELOP IN WHAT SHOULD BE A
WET/CLOUDY DAY VOID OF STRONG INSOLATION. WILL INCREASE POPS INTO
THE LOW-LIKELY RANGES(55 TO 60 PERCENT). HIGHS SATURDAY IN THE
LOWER TO MID 70S...WITH HIGHS SUNDAY A GOOD ONE TO TWO CATEGORIES
COOLER GIVEN EXPECTED WIDESPREAD RAIN...BUT AGAIN LARGELY
DEPENDENT ON TRACK OF SURFACE LOW AND RESULTANT WARM SECTOR.
MONDAY AND TUESDAY...DECREASING RAIN CHANCES ON MONDAY AS SYSTEM
LIFTS OFF TO THE NORTHEAST WITH DRY CONDITIONS ON MONDAY.
SEASONABLE TO SLIGHTLY BELOW TEMPERATURES WITH THE NEGATIVE HEIGHT
ANOMALIES UNDERNEATH THE EASTERN US UPPER TROUGH.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
AS OF 815 PM TUESDAY...
SHOWERS AND THUNDERSTORMS AND ASSOCIATED BRIEF SUB VFR
CONDITIONS... MAINLY AT KINT/KGSO DUE TO THE PROXIMITY OF A
SURFACE FRONT THERE...WILL REMAIN A POSSIBILITY THROUGH ABOUT 9 TO
11 PM... BEFORE DIMINISHING WITH THE LOSS OF DAYTIME HEATING AND
RESULTANT INSTABILITY. OTHERWISE...GENERALLY VFR CONDITIONS WILL
PERSIST THROUGH TONIGHT. MEANWHILE...THE APPROACH OF AN UPPER
LEVEL TROUGH ON WEDNESDAY WILL AID IN THE DEVELOPMENT OF LOWERING
CEILINGS AND RAIN POTENTIAL AS WARMER AIR TO OUR SOUTH RISES ATOP
COOLER AIR ASSOCIATED WITH A HIGH PRESSURE SYSTEM THAT WILL EXPAND
ACROSS VIRGINIA. ASSOCIATED CEILINGS WILL GRADUALLY LOWER TO MVFR
RANGE -- FIRST AT KFAY DURING THE MORNING HOURS -- THEN ELSEWHERE
THROUGH LATE AFTERNOON. IN ADDITION... FORECAST SOUNDINGS INDICATE
MOISTENING THROUGHOUT THE DEPTH OF THE ATMOSPHERE...WHICH SUGGESTS
THE AFOREMENTIONED PROBABILITY OF RAIN WILL ALSO INCREASE FROM
WEST TO EAST WITH THE APPROACH OF THE UPPER LEVEL TROUGH LATE IN
THE DAY. WINDS WILL REMAIN LIGHT FROM THE NORTHEAST THROUGH
WEDNESDAY.
OUTLOOK...MVFR CONDITIONS WILL LIKELY BECOME IFR OVERNIGHT
WEDNESDAY...AND PERSIST INTO AT LEAST EARLY THURSDAY IN
ASSOCIATION WITH THE DEVELOPMENT OF A COLD AIR DAMMING WEDGE.
WHEN THE COLD AIR DAMMING WEDGE WILL ERODE AND VFR CONDITIONS WILL
RETURN REMAINS DIFFICULT TO ASCERTAIN AT THIS TIME. IT IS POSSIBLE
THAT MVFR AND PERIODIC IFR (OVERNIGHT) CEILINGS MAY LINGER THROUGH
THURSDAY/FRIDAY IN ASSOCIATION WITH A REMNANT COLD AIR DAMMING
WEDGE AND LOW LEVEL SOUTHERLY RETURN FLOW. A POTENTIALLY
SIGNIFICANT STORM SYSTEM MAY AFFECT THE CAROLINAS OVER THE
WEEKEND...THOUGH UNCERTAINTY REMAINS HIGH WITH THIS SYSTEM AS
WELL.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CBL/KRR
LONG TERM...CBL
AVIATION...MWS/VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
146 PM EDT MON APR 16 2012
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO MOVE SLOWLY EAST...CROSSING THE
WESTERN HALF OF NORTH CAROLINA OVERNIGHT. THE FRONT THEN REMAINS
NEARLY STATIONARY TOWARD THE COAST TUESDAY NIGHT INTO WEDNESDAY.
WEAK HIGH PRESSURE BUILDS INTO THE REGION BEHIND THE COLD FRONT
THURSDAY.
&&
.NEAR TERM /TODAY/...
AS OF 1020 AM MONDAY...
THE LATEST SURFACE ANALYSIS SHOWED HIGH PRESSURE JUST OFFSHORE
NOSING WEST THROUGH CENTRAL NORTH CAROLINA...WITH MSAS INDICATIVE OF
SURFACE-BASED DIVERGENCE OVER THE AREA. ON UPPER-AIR ANALYSES...
850MB MOISTURE WAS BEGINNING TO MOVE THROUGH THE WESTERN THIRD OF
THE STATE...WITH 850MB DEW POINTS JUST BELOW 10C. HOWEVER...THE MID-
AND UPPER-LEVEL RIDGE AXES WERE FIRMLY IN PLACE OVER THE FAR EASTERN
PART OF THE STATE AND ALONG THE COAST...WITH CONSIDERABLE DRY AIR
NOTED AT 700MB AND VERY DRY AIR ALSO NOTED IN THE MID-LEVELS ON
WATER VAPOR IMAGERY. THE LATEST NAM BUFR SOUNDINGS REMAINED STABLE
DURING THE DAY...AS THE CAP AT AND JUST ABOVE 700MB HOLDS EVEN AS
850MB THETA-E VALUES INCREASE OVER THE WESTERN PIEDMONT AND
PRECIPITABLE WATER VALUES RISE TO NEARLY 1.25 INCHES. THE RUC IS NOT
AS UNSTABLE AS THE NAM THIS AFTERNOON...LIFTED INDICES OF 0C TO -1C
ON THE FORMER VERSUS -2C TO -3C ON THE LATTER...AND EVEN THE NAM IS
PREDOMINANTLY SUBSIDENT DURING THE AFTERNOON. WILL CONTINUE TO KEEP
THE FORECAST DRY.
MORNING KGSO AND AMDAR SOUNDINGS SHOWED WINDS ONCE AGAIN JUST OFF
THE SURFACE A LITTLE HIGHER THAN WAS FORECAST BY SUNDAY GUIDANCE...
CLOSE TO 40KT. AS MIXING OCCURS THESE WINDS SHOULD DIMINISH...AND
MIXING SHOULD NOT TAKE PLACE FAST ENOUGH TO RESULT IN GUSTS BEYOND
THE 20S KTS. BUFR SOUNDINGS SHOW GUST POTENTIAL IS HIGHEST TOWARD
KGSO...WHERE SOME GUSTS APPROACHING 25KT ARE POSSIBLE. 1000-850MB
THICKNESSES SUPPORT HIGHS AS CURRENTLY FORECAST...SOLIDLY 81 TO 86
WITH MAYBE A LOCATION OR TWO APPROACHING THE UPPER 80S. SURFACE DEW
POINTS WILL BE SIMILAR TO SUNDAY...AND WITH THE WARMER TEMPERATURES
RELATIVE HUMIDITIES WILL BE A LITTLE LOWER...BOTTOMING OUT AT OR
JUST BELOW 35 PERCENT. WITH THE DRY FUELS IN PLACE...AN INCREASED
FIRE DANGER CONTINUES TO BE NOTED FOR THE AFTERNOON...INTO EARLY
EVENING.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 345 AM MONDAY...
OVERVIEW:
SHORTWAVE ENERGY DIGGING SOUTHEAST THROUGH THE 4-CORNERS REGION AT
06Z THIS MORNING WILL ROUND THE BASE OF THE LONGWAVE TROUGH PRESENT
OVER THE CENTRAL CONUS TODAY...THEN PROGRESS EASTWARD INTO THE DEEP
SOUTH DURING THE DAY TUESDAY AS A MORE ZONAL PATTERN DEVELOPS OVER
THE LOWER 48 IN THE WAKE OF THE DEAMPLIFYING UPPER LEVEL LOW
PROGRESSING TOWARD THE CANADIAN MARITIMES. THE FRONT WILL BECOME
INCREASINGLY W-E ORIENTED OVER THE AREA TONIGHT AS THE PARENT LOW
WEAKENS AND TRACKS WELL NORTHEAST INTO CANADA. THE FRONT IS EXPECTED
TO STALL OUT NEAR THE SANDHILLS/COASTAL PLAIN PORTION OF THE NC/SC
BORDER DURING THE DAY TUE.
TONIGHT:
MID-LEVEL LAPSE RATES WILL WEAKEN FROM WEST-EAST OVERNIGHT AS THE
UPPER LEVEL RIDGE SHIFTS OFFSHORE...HOWEVER...INCREASING BOUNDARY
LAYER MOISTURE IN ASSOC/W THE FRONTAL ZONE PROGRESSING INTO THE AREA
MAY ALLOW FOR A VERY MARGINAL AMOUNT OF MUCAPE...ON THE ORDER OF 250
J/KG. W/REGARD TO FORCING...VERY WEAK/SHALLOW LOW LEVEL CONVERGENCE
WILL BE PRESENT OVER THE AREA AS THE FRONT SLOWS DOWN AND BECOMES
INCREASINGLY W-E ORIENTED OVER THE AREA. ALTHOUGH A WEAK DISTURBANCE
IN SOUTHWEST FLOW ALOFT CANNOT BE RULED OUT...THE AFOREMENTIONED
SHORTWAVE IS EXPECTED TO PROGRESS NO FURTHER THAN EASTERN TX BY 12Z
TUE...AND THE BEST CHANCE FOR SMALL AMPLITUDE DISTURBANCES OR
CONVECTIVE RELATED FEATURES IS EXPECTED TO BE UPSTREAM IN THE DEEP
SOUTH. IF AN UPPER LEVEL DISTURBANCE PROGRESSES INTO THE AREA VIA SW
FLOW ALOFT IN THE PRESENCE OF MARGINAL MUCAPE AND WEAK/SHALLOW
LOW-LEVEL CONVERGENCE A FEW ISOLD SHOWERS COULD NOT BE RULED OUT IN
THE WEST/SW PIEDMONT...THOUGH THAT SCENARIO APPEARS UNLIKELY. WITH
THE ABOVE IN MIND...WILL KEEP THE FCST DRY. GIVEN INCREASING
BOUNDARY LAYER MOISTURE AND LOW/MID LEVEL CLOUD COVER...EXPECT LOWS
IN THE LOWER/MID 60S.
TUESDAY:
COMPLEX FORECAST. THE AFOREMENTIONED SHORTWAVE WILL PROGRESS EAST
INTO THE DEEP SOUTH (MS/AL) BY TUE AFT/EVE...WITH BROAD H5 HEIGHT
FALLS (40 METERS 12-00Z) DOWNSTREAM OVER THE CAROLINAS ALONG WITH AN
INCREASING POTENTIAL FOR SMALL AMPLITUDE DISTURBANCES OR CONVECTIVE
RELATED FEATURES PROGRESSING INTO THE AREA VIA SW FLOW ALOFT.
HOWEVER...THE BEST UPPER LEVEL FORCING ASSOC/W THE SHORTWAVE WILL
REMAIN WELL UPSTREAM OF THE AREA (MS/AL)...AND THE TIMING/LOCATION
OF ANY SMALLER AMPLITUDE DISTURBANCES ARE VERY MUCH IN QUESTION AT
THIS TIME...AND MAY ULTIMATELY DEPEND ON THE EVOLUTION OF DEEP
CONVECTION OVER THE LOWER MS RIVER VALLEY LATE TONIGHT AND TUE
MORNING. COMPLICATING MATTERS FURTHER...MODEL GUIDANCE VARIES ON THE
POSITION OF THE STALLED FRONTAL ZONE ON TUE...RANGING FROM DIRECTLY
OVER CENTRAL NC (00Z ECMWF)...TO JUST S/SE OF THE AREA (00Z GFS)...
TO PORTIONS OF THE SANDHILLS/SE COASTAL PLAIN (00Z NAM). THE
LOCATION OF THE SFC FRONT WILL LARGELY DETERMINE THE LOCATION/EXTENT
OF DIURNAL DESTABILIZATION TUE AFTERNOON. REGARDLESS...THE RELATIVE
BEST INSTABILITY IS EXPECTED TO BE PRESENT IN FAR S/SE PORTIONS OF
THE AREA WHERE 500-1000 J/KG OF MLCAPE IS PROGGED. GIVEN
CONSIDERABLE UNCERTAINTY WITH THE TIMING/LOCATION OF UPPER LEVEL
FORCING AND THE SURFACE FRONT AS MENTIONED ABOVE...WILL LEAVE THE
PREVIOUS FCST MORE OR LESS INTACT...INDICATING CHANCES FOR
SHOWERS/STORMS RANGING FROM 20-50%...LOWEST IN THE NE COASTAL PLAIN
AND HIGHEST NEAR THE SC BORDER/SE COASTAL PLAIN. HIGH TEMPS ARE
EQUALLY CHALLENGING ON TUE...WITH A BUST POTENTIAL OF 3-7F DEPENDING
ON THE LOCATION OF FRONT AND TIMING/LOCATION OF ANY CONVECTION THAT
MAY BE PRESENT. A BLEND OF MODEL GUIDANCE APPEARS REASONABLE...WITH
HIGHS RANGING FROM THE LOWER 80S SOUTH/SE TO MID 70S N/NW.
SEVERE THREAT:
SPC HAS HIGHLIGHTED A SLIGHT RISK FOR SEVERE STORMS OVER GA/SC AND
FAR SOUTHERN PORTIONS OF CENTRAL NC...PRIMARILY ADJACENT TO THE SC
BORDER. CONSIDERABLE UNCERTAINTY PERSISTS WITH REGARD TO THE
LOCATION/COVERAGE OF CONVECTION TUE AFTERNOON AS MENTIONED ABOVE...
THOUGH THE MOST LIKELY LOCATION IS IN THE FAR SW PIEDMONT...
SANDHILLS AND SE COASTAL PLAIN WHERE 500-1000 J/KG MLCAPE IS
PROGGED. THE HEIGHT GRADIENT ALOFT WILL TIGHTEN OVER THE CAROLINAS
ON TUE AS THE SHORTWAVE PROGRESSES INTO THE DEEP SOUTH...AND 0-6 KM
BULK SHEAR VALUES ARE PROGGED TO BE AT LEAST IN THE 30-35 KT RANGE
IN SOUTHERN PORTIONS OF THE AREA (HIGHER NORTH)...WITH LARGER
AMOUNTS (40-45 KT) POSSIBLE. AS A RESULT...DEEP LAYER SHEAR WILL
CERTAINLY BE SUFFICIENT FOR MULTICELLULAR ORGANIZATION...AND
POSSIBLY SUPERCELLULAR. GIVEN VERY WEAK LOW-LEVEL SHEAR...EVEN IN
VICINITY OF THE STALLED FRONT...THE PRIMARY SEVERE THREAT WILL
LIKELY BE CONFINED TO HAIL/WIND. AN ISOLD BRIEF/WEAK TORNADO COULD
NOT BE ENTIRELY RULED OUT...THOUGH ONLY IN ASSOCIATION WITH
STORM-SCALE INTERACTIONS. -VINCENT
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
AS OF 325 AM MONDAY...
COOLER AND DAMP PERIOD MID WEEK... POTENTIAL FOR HEAVY RAIN NEXT
WEEKEND...
MODELS CONTINUE TO POINT TOWARD A COOL DAMP PERIOD TUESDAY NIGHT
THROUGH WEDNESDAY NIGHT... FOLLOWED BY A GRADUAL DRYING AND WARMING
THURSDAY AND FRIDAY. IT APPEARS THAT A FINAL MID-UPPER LEVEL WAVE
WILL BE DAMPENING OUT AS IT MOVES EAST ACROSS OUR REGION WEDNESDAY
AFTERNOON AND EVENING. THIS WEAKENING TREND IS SUPPORTED BY THE
MODELS GIVEN THE EXPECTED INCREASING ZONAL FLOW ALOFT DURING THE
PERIOD. AT THE SURFACE... A COOL HIGH PRESSURE IS EXPECTED TO BECOME
FULLY ESTABLISHED FROM NEW ENGLAND SOUTHWARD INTO SC BY 12Z/WED.
THIS HIGH IS OF SUFFICIENT STRENGTH (1025+ MB) AND FAVORABLE
POSITION (NY AND PA) FOR THE DEVELOPMENT OF A SPRING TIME CAD EVENT
OVER OUR REGION. THE TEMPERATURES WEDNESDAY MAY STAY IN THE 50S FOR
MUCH OF THE PIEDMONT ESPECIALLY IF THE QPF OF 0.25 TO 0.50 FORECAST
BY MOST MODELS IS REALIZED.
THE MID LEVEL WAVE IS EXPECTED TO REMAIN STRONG ENOUGH TO HELP
GENERATE ENOUGH LIFT FOR LIGHT TO MODERATE STRATIFORM RAINS OVER OUR
REGION WEDNESDAY. THE BEST CHANCE OF RAIN APPEARS THAT IT WILL BEGIN
IN THE SW-W PIEDMONT EARLY IN THE DAY... THEN SPREAD EAST ACROSS
CENTRAL AND EASTERN AREAS DURING THE DAY. HIGHS WILL LIKELY BE ONLY
IN THE UPPER 50S NW TO UPPER 60S SE. IT APPEARS THAT THUNDER WOULD
BE HARD TO COME BY GIVEN THE DAMPENING WAVE ALOFT AND THE
STRENGTHENING CAD CONDITIONS/STABILITY NEAR THE SURFACE. WE WILL
CARRY LIKELY POP FOR RAIN IN THE WEST DURING THE MORNING... AND
CHANCES EAST... SPREADING THE LIKELY POP EAST TO COVER ALL ZONES BY
AFTERNOON AND EVENING. ONCE THE WAVE PASSES... THE RAIN IS EXPECTED
TO TAPER OFF BY 12Z/THU. WE WILL KEEP SOME LOW POP IN THE COASTAL
PLAIN THROUGH 15Z OR SO THU... FOLLOWED BY GRADUAL CLEARING DURING
THE DAY. THE CONTINUED NE FLOW WILL LIKELY MEAN A SLOW CLEARING
PATTERN. SKIES SHOULD BECOME PARTLY CLOUDY THU AFTERNOON AND
CONTINUE INTO FRIDAY AS WEAK HIGH PRESSURE WILL LINGER OVER NC...
BEFORE SHIFTING OFFSHORE FRIDAY. HIGHS THURSDAY AND FRIDAY WILL
RECOVER BACK INTO THE 70S RATHER SLOWLY.
FOR FRIDAY NIGHT THROUGH THE WEEKEND...
THE CONTINUES TO BE A LARGE SPREAD OF SOLUTIONS FOR AN EXPECTED EAST
COAST TROUGH/LOW PRESSURE DEVELOPMENT. THE LATEST GFS AND EC
INDICATE A COASTAL STORM BY LATE SAT-SUN WITH A CHILLY RAIN FOR
CENTRAL NC. PLAN NOW IS TO KEEP CURRENT FORECAST CONTINUITY... WITH
BEST CHANCE OF RAIN OVER THE WEEKEND. THE EC SOLUTION IS ON THE SW
SIDE OF THE ENVELOP OF SOLUTIONS (STRONG SURFACE LOW DEVELOPS OVER
NW GULF OF MEX SATURDAY... THEN DEEPENS (990 MB) AS IT RIDES NE OVER
NC SUNDAY. THIS SOLUTION IS ALSO ON THE EXTREME DEEP SIDE OF THE
OTHER GUIDANCE. HOWEVER... MOST SOLUTIONS INDICATE A POTENTIAL FOR
HEAVY RAIN... A PERIOD OF STRONG STORMS WITH THE ACTUAL COLD
FRONT... AND EVEN A TURN TO A CHILLY RAIN LATE IN THE WEEKEND. WE
WILL TREND THE FORECAST TOWARD A WETTER SOLUTION SAT-SUN.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 145 PM MONDAY...
PRIMARY AVIATION IMPACTS DURING THE 18Z VALID TAF PERIOD WILL BE THE
GUSTY WINDS CONTINUING THROUGH THE AFTERNOON INTO THE EARLY
EVENING...AND AN APPROACH OF A COLD FRONT INTO CENTRAL NORTH
CAROLINA OVERNIGHT AND EARLY TUESDAY. THE LATEST GUIDANCE SUGGESTS
RELATIVELY LOW CHANCES FOR LOW CLOUDS OVERNIGHT...INSTEAD FOCUSING
ON ANY CLOUD DEVELOPMENT REMAINING IN THE VFR RANGE. WINDS WILL
START TO VEER FIRST IN THE TRIAD LIKELY IN VICINITY OF 08Z...AND
SLIGHTLY LATER TOWARD 10Z TO 12Z AT KRDU AND KRWI. THERE IS SOME
DIFFICULTY IN THE EXACT TIMING OF THE COLD FRONT TOWARD KFAY...AND
IT IS MORE LIKELY THAT KFAY WILL BE IN THE FRONTAL ZONE DURING
TUESDAY MORNING WITH A LIGHTER WIND VEERING MORE SLOWLY THAN
ELSEWHERE IN CENTRAL NORTH CAROLINA.
BEYOND THE 18Z VALID TAF PERIOD...ADVERSE AVIATION CONDITIONS IN
DEVELOPING SHOWERS AND THUNDERSTORMS...MORE NUMEROUS TOWARD KFAY...
EXIST TUESDAY AFTERNOON AND TUESDAY EVENING. THE LIKELIHOOD OF
SHOWERS AND SCATTERED THUNDERSTORMS MOVES NORTH TUESDAY NIGHT...AND
THE LIKELIHOOD OF IFR CEILINGS OUTSIDE OF ANY THUNDERSTORM BUILDS
GREATLY TOWARD THE TRIAD ESPECIALLY OVERNIGHT TUESDAY. WIDESPREAD
IFR CONDITIONS IN LOW CLOUDS BUILDS SOUTHEAST ENCOMPASSING ALL OF
CENTRAL NORTH CAROLINA BY WEDNESDAY NIGHT...BEFORE CONDITIONS SLOWLY
IMPROVE THURSDAY. THE NEXT BEST CHANCES FOR ADVERSE AVIATION
CONDITIONS OCCUR SATURDAY AND SATURDAY NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1020 AM EDT MON APR 16 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE MOUNTAINS FROM THE WEST TODAY...THEN
PROGRESS INTO CENTRAL NORTH CAROLINA TONIGHT. THE FRONT IS EXPECTED
TO STALL OUT IN VICINITY OF THE SOUTHEAST COAST THROUGH MID WEEK.
&&
.NEAR TERM /TODAY/...
AS OF 1020 AM MONDAY...
THE LATEST SURFACE ANALYSIS SHOWED HIGH PRESSURE JUST OFFSHORE
NOSING WEST THROUGH CENTRAL NORTH CAROLINA...WITH MSAS INDICATIVE OF
SURFACE-BASED DIVERGENCE OVER THE AREA. ON UPPER-AIR ANALYSES...
850MB MOISTURE WAS BEGINNING TO MOVE THROUGH THE WESTERN THIRD OF
THE STATE...WITH 850MB DEW POINTS JUST BELOW 10C. HOWEVER...THE MID-
AND UPPER-LEVEL RIDGE AXES WERE FIRMLY IN PLACE OVER THE FAR EASTERN
PART OF THE STATE AND ALONG THE COAST...WITH CONSIDERABLE DRY AIR
NOTED AT 700MB AND VERY DRY AIR ALSO NOTED IN THE MID-LEVELS ON
WATER VAPOR IMAGERY. THE LATEST NAM BUFR SOUNDINGS REMAINED STABLE
DURING THE DAY...AS THE CAP AT AND JUST ABOVE 700MB HOLDS EVEN AS
850MB THETA-E VALUES INCREASE OVER THE WESTERN PIEDMONT AND
PRECIPITABLE WATER VALUES RISE TO NEARLY 1.25 INCHES. THE RUC IS NOT
AS UNSTABLE AS THE NAM THIS AFTERNOON...LIFTED INDICES OF 0C TO -1C
ON THE FORMER VERSUS -2C TO -3C ON THE LATTER...AND EVEN THE NAM IS
PREDOMINANTLY SUBSIDENT DURING THE AFTERNOON. WILL CONTINUE TO KEEP
THE FORECAST DRY.
MORNING KGSO AND AMDAR SOUNDINGS SHOWED WINDS ONCE AGAIN JUST OFF
THE SURFACE A LITTLE HIGHER THAN WAS FORECAST BY SUNDAY GUIDANCE...
CLOSE TO 40KT. AS MIXING OCCURS THESE WINDS SHOULD DIMINISH...AND
MIXING SHOULD NOT TAKE PLACE FAST ENOUGH TO RESULT IN GUSTS BEYOND
THE 20S KTS. BUFR SOUNDINGS SHOW GUST POTENTIAL IS HIGHEST TOWARD
KGSO...WHERE SOME GUSTS APPROACHING 25KT ARE POSSIBLE. 1000-850MB
THICKNESSES SUPPORT HIGHS AS CURRENTLY FORECAST...SOLIDLY 81 TO 86
WITH MAYBE A LOCATION OR TWO APPROACHING THE UPPER 80S. SURFACE DEW
POINTS WILL BE SIMILAR TO SUNDAY...AND WITH THE WARMER TEMPERATURES
RELATIVE HUMIDITIES WILL BE A LITTLE LOWER...BOTTOMING OUT AT OR
JUST BELOW 35 PERCENT. WITH THE DRY FUELS IN PLACE...AN INCREASED
FIRE DANGER CONTINUES TO BE NOTED FOR THE AFTERNOON...INTO EARLY
EVENING.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 345 AM MONDAY...
OVERVIEW:
SHORTWAVE ENERGY DIGGING SOUTHEAST THROUGH THE 4-CORNERS REGION AT
06Z THIS MORNING WILL ROUND THE BASE OF THE LONGWAVE TROUGH PRESENT
OVER THE CENTRAL CONUS TODAY...THEN PROGRESS EASTWARD INTO THE DEEP
SOUTH DURING THE DAY TUESDAY AS A MORE ZONAL PATTERN DEVELOPS OVER
THE LOWER 48 IN THE WAKE OF THE DEAMPLIFYING UPPER LEVEL LOW
PROGRESSING TOWARD THE CANADIAN MARITIMES. THE FRONT WILL BECOME
INCREASINGLY W-E ORIENTED OVER THE AREA TONIGHT AS THE PARENT LOW
WEAKENS AND TRACKS WELL NORTHEAST INTO CANADA. THE FRONT IS EXPECTED
TO STALL OUT NEAR THE SANDHILLS/COASTAL PLAIN PORTION OF THE NC/SC
BORDER DURING THE DAY TUE.
TONIGHT:
MID-LEVEL LAPSE RATES WILL WEAKEN FROM WEST-EAST OVERNIGHT AS THE
UPPER LEVEL RIDGE SHIFTS OFFSHORE...HOWEVER...INCREASING BOUNDARY
LAYER MOISTURE IN ASSOC/W THE FRONTAL ZONE PROGRESSING INTO THE AREA
MAY ALLOW FOR A VERY MARGINAL AMOUNT OF MUCAPE...ON THE ORDER OF 250
J/KG. W/REGARD TO FORCING...VERY WEAK/SHALLOW LOW LEVEL CONVERGENCE
WILL BE PRESENT OVER THE AREA AS THE FRONT SLOWS DOWN AND BECOMES
INCREASINGLY W-E ORIENTED OVER THE AREA. ALTHOUGH A WEAK DISTURBANCE
IN SOUTHWEST FLOW ALOFT CANNOT BE RULED OUT...THE AFOREMENTIONED
SHORTWAVE IS EXPECTED TO PROGRESS NO FURTHER THAN EASTERN TX BY 12Z
TUE...AND THE BEST CHANCE FOR SMALL AMPLITUDE DISTURBANCES OR
CONVECTIVE RELATED FEATURES IS EXPECTED TO BE UPSTREAM IN THE DEEP
SOUTH. IF AN UPPER LEVEL DISTURBANCE PROGRESSES INTO THE AREA VIA SW
FLOW ALOFT IN THE PRESENCE OF MARGINAL MUCAPE AND WEAK/SHALLOW
LOW-LEVEL CONVERGENCE A FEW ISOLD SHOWERS COULD NOT BE RULED OUT IN
THE WEST/SW PIEDMONT...THOUGH THAT SCENARIO APPEARS UNLIKELY. WITH
THE ABOVE IN MIND...WILL KEEP THE FCST DRY. GIVEN INCREASING
BOUNDARY LAYER MOISTURE AND LOW/MID LEVEL CLOUD COVER...EXPECT LOWS
IN THE LOWER/MID 60S.
TUESDAY:
COMPLEX FORECAST. THE AFOREMENTIONED SHORTWAVE WILL PROGRESS EAST
INTO THE DEEP SOUTH (MS/AL) BY TUE AFT/EVE...WITH BROAD H5 HEIGHT
FALLS (40 METERS 12-00Z) DOWNSTREAM OVER THE CAROLINAS ALONG WITH AN
INCREASING POTENTIAL FOR SMALL AMPLITUDE DISTURBANCES OR CONVECTIVE
RELATED FEATURES PROGRESSING INTO THE AREA VIA SW FLOW ALOFT.
HOWEVER...THE BEST UPPER LEVEL FORCING ASSOC/W THE SHORTWAVE WILL
REMAIN WELL UPSTREAM OF THE AREA (MS/AL)...AND THE TIMING/LOCATION
OF ANY SMALLER AMPLITUDE DISTURBANCES ARE VERY MUCH IN QUESTION AT
THIS TIME...AND MAY ULTIMATELY DEPEND ON THE EVOLUTION OF DEEP
CONVECTION OVER THE LOWER MS RIVER VALLEY LATE TONIGHT AND TUE
MORNING. COMPLICATING MATTERS FURTHER...MODEL GUIDANCE VARIES ON THE
POSITION OF THE STALLED FRONTAL ZONE ON TUE...RANGING FROM DIRECTLY
OVER CENTRAL NC (00Z ECMWF)...TO JUST S/SE OF THE AREA (00Z GFS)...
TO PORTIONS OF THE SANDHILLS/SE COASTAL PLAIN (00Z NAM). THE
LOCATION OF THE SFC FRONT WILL LARGELY DETERMINE THE LOCATION/EXTENT
OF DIURNAL DESTABILIZATION TUE AFTERNOON. REGARDLESS...THE RELATIVE
BEST INSTABILITY IS EXPECTED TO BE PRESENT IN FAR S/SE PORTIONS OF
THE AREA WHERE 500-1000 J/KG OF MLCAPE IS PROGGED. GIVEN
CONSIDERABLE UNCERTAINTY WITH THE TIMING/LOCATION OF UPPER LEVEL
FORCING AND THE SURFACE FRONT AS MENTIONED ABOVE...WILL LEAVE THE
PREVIOUS FCST MORE OR LESS INTACT...INDICATING CHANCES FOR
SHOWERS/STORMS RANGING FROM 20-50%...LOWEST IN THE NE COASTAL PLAIN
AND HIGHEST NEAR THE SC BORDER/SE COASTAL PLAIN. HIGH TEMPS ARE
EQUALLY CHALLENGING ON TUE...WITH A BUST POTENTIAL OF 3-7F DEPENDING
ON THE LOCATION OF FRONT AND TIMING/LOCATION OF ANY CONVECTION THAT
MAY BE PRESENT. A BLEND OF MODEL GUIDANCE APPEARS REASONABLE...WITH
HIGHS RANGING FROM THE LOWER 80S SOUTH/SE TO MID 70S N/NW.
SEVERE THREAT:
SPC HAS HIGHLIGHTED A SLIGHT RISK FOR SEVERE STORMS OVER GA/SC AND
FAR SOUTHERN PORTIONS OF CENTRAL NC...PRIMARILY ADJACENT TO THE SC
BORDER. CONSIDERABLE UNCERTAINTY PERSISTS WITH REGARD TO THE
LOCATION/COVERAGE OF CONVECTION TUE AFTERNOON AS MENTIONED ABOVE...
THOUGH THE MOST LIKELY LOCATION IS IN THE FAR SW PIEDMONT...
SANDHILLS AND SE COASTAL PLAIN WHERE 500-1000 J/KG MLCAPE IS
PROGGED. THE HEIGHT GRADIENT ALOFT WILL TIGHTEN OVER THE CAROLINAS
ON TUE AS THE SHORTWAVE PROGRESSES INTO THE DEEP SOUTH...AND 0-6 KM
BULK SHEAR VALUES ARE PROGGED TO BE AT LEAST IN THE 30-35 KT RANGE
IN SOUTHERN PORTIONS OF THE AREA (HIGHER NORTH)...WITH LARGER
AMOUNTS (40-45 KT) POSSIBLE. AS A RESULT...DEEP LAYER SHEAR WILL
CERTAINLY BE SUFFICIENT FOR MULTICELLULAR ORGANIZATION...AND
POSSIBLY SUPERCELLULAR. GIVEN VERY WEAK LOW-LEVEL SHEAR...EVEN IN
VICINITY OF THE STALLED FRONT...THE PRIMARY SEVERE THREAT WILL
LIKELY BE CONFINED TO HAIL/WIND. AN ISOLD BRIEF/WEAK TORNADO COULD
NOT BE ENTIRELY RULED OUT...THOUGH ONLY IN ASSOCIATION WITH
STORM-SCALE INTERACTIONS. -VINCENT
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
AS OF 325 AM MONDAY...
COOLER AND DAMP PERIOD MID WEEK... POTENTIAL FOR HEAVY RAIN NEXT
WEEKEND...
MODELS CONTINUE TO POINT TOWARD A COOL DAMP PERIOD TUESDAY NIGHT
THROUGH WEDNESDAY NIGHT... FOLLOWED BY A GRADUAL DRYING AND WARMING
THURSDAY AND FRIDAY. IT APPEARS THAT A FINAL MID-UPPER LEVEL WAVE
WILL BE DAMPENING OUT AS IT MOVES EAST ACROSS OUR REGION WEDNESDAY
AFTERNOON AND EVENING. THIS WEAKENING TREND IS SUPPORTED BY THE
MODELS GIVEN THE EXPECTED INCREASING ZONAL FLOW ALOFT DURING THE
PERIOD. AT THE SURFACE... A COOL HIGH PRESSURE IS EXPECTED TO BECOME
FULLY ESTABLISHED FROM NEW ENGLAND SOUTHWARD INTO SC BY 12Z/WED.
THIS HIGH IS OF SUFFICIENT STRENGTH (1025+ MB) AND FAVORABLE
POSITION (NY AND PA) FOR THE DEVELOPMENT OF A SPRING TIME CAD EVENT
OVER OUR REGION. THE TEMPERATURES WEDNESDAY MAY STAY IN THE 50S FOR
MUCH OF THE PIEDMONT ESPECIALLY IF THE QPF OF 0.25 TO 0.50 FORECAST
BY MOST MODELS IS REALIZED.
THE MID LEVEL WAVE IS EXPECTED TO REMAIN STRONG ENOUGH TO HELP
GENERATE ENOUGH LIFT FOR LIGHT TO MODERATE STRATIFORM RAINS OVER OUR
REGION WEDNESDAY. THE BEST CHANCE OF RAIN APPEARS THAT IT WILL BEGIN
IN THE SW-W PIEDMONT EARLY IN THE DAY... THEN SPREAD EAST ACROSS
CENTRAL AND EASTERN AREAS DURING THE DAY. HIGHS WILL LIKELY BE ONLY
IN THE UPPER 50S NW TO UPPER 60S SE. IT APPEARS THAT THUNDER WOULD
BE HARD TO COME BY GIVEN THE DAMPENING WAVE ALOFT AND THE
STRENGTHENING CAD CONDITIONS/STABILITY NEAR THE SURFACE. WE WILL
CARRY LIKELY POP FOR RAIN IN THE WEST DURING THE MORNING... AND
CHANCES EAST... SPREADING THE LIKELY POP EAST TO COVER ALL ZONES BY
AFTERNOON AND EVENING. ONCE THE WAVE PASSES... THE RAIN IS EXPECTED
TO TAPER OFF BY 12Z/THU. WE WILL KEEP SOME LOW POP IN THE COASTAL
PLAIN THROUGH 15Z OR SO THU... FOLLOWED BY GRADUAL CLEARING DURING
THE DAY. THE CONTINUED NE FLOW WILL LIKELY MEAN A SLOW CLEARING
PATTERN. SKIES SHOULD BECOME PARTLY CLOUDY THU AFTERNOON AND
CONTINUE INTO FRIDAY AS WEAK HIGH PRESSURE WILL LINGER OVER NC...
BEFORE SHIFTING OFFSHORE FRIDAY. HIGHS THURSDAY AND FRIDAY WILL
RECOVER BACK INTO THE 70S RATHER SLOWLY.
FOR FRIDAY NIGHT THROUGH THE WEEKEND...
THE CONTINUES TO BE A LARGE SPREAD OF SOLUTIONS FOR AN EXPECTED EAST
COAST TROUGH/LOW PRESSURE DEVELOPMENT. THE LATEST GFS AND EC
INDICATE A COASTAL STORM BY LATE SAT-SUN WITH A CHILLY RAIN FOR
CENTRAL NC. PLAN NOW IS TO KEEP CURRENT FORECAST CONTINUITY... WITH
BEST CHANCE OF RAIN OVER THE WEEKEND. THE EC SOLUTION IS ON THE SW
SIDE OF THE ENVELOP OF SOLUTIONS (STRONG SURFACE LOW DEVELOPS OVER
NW GULF OF MEX SATURDAY... THEN DEEPENS (990 MB) AS IT RIDES NE OVER
NC SUNDAY. THIS SOLUTION IS ALSO ON THE EXTREME DEEP SIDE OF THE
OTHER GUIDANCE. HOWEVER... MOST SOLUTIONS INDICATE A POTENTIAL FOR
HEAVY RAIN... A PERIOD OF STRONG STORMS WITH THE ACTUAL COLD
FRONT... AND EVEN A TURN TO A CHILLY RAIN LATE IN THE WEEKEND. WE
WILL TREND THE FORECAST TOWARD A WETTER SOLUTION SAT-SUN.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM MONDAY...
24-HR TAF PERIOD:
A STRONG MID-LEVEL SUBSIDENCE INVERSION ASSOC/W THE UPPER LEVEL
RIDGE CURRENTLY IN PLACE (THOUGH BEGINNING TO SHIFT OFFSHORE THIS
AFTERNOON THROUGH TONIGHT) WILL REMAIN IN PLACE OVER CENTRAL NC
THROUGH THE REMAINDER OF THE TAF PERIOD...AND EXPECT VFR CONDITIONS
TO PREVAIL WITH SCATTERED DIURNAL CU (6 KFT AGL) DURING PEAK
HEATING. A 5-10 KT SOUTHWESTERLY BREEZE WILL INCREASE TO 10-15 KT
SUSTAINED WITH GUSTS UP TO 20-25 KT BY 15Z IN ASSOC/W A TIGHTENING
MSLP GRADIENT AND STRONG DIURNAL HEATING/MIXING. WINDS WILL BECOME
WEST SOUTHWEST AND WEAKEN TO 5-10 KT AT SUNSET...THEN VEERING TO THE
NORTH/NE AT 10 KT BETWEEN 06-12Z TUE MORNING IN ASSOC/W A COLD FRONT
PROGRESSING THROUGH THE AREA FROM NORTH-SOUTH.
LOOKING AHEAD:
THE NEXT CHANCE FOR SUB-VFR CONDITIONS IS EXPECTED TO BE ASSOC/W SCT
SHOWERS AND STORMS DURING THE DAY TUESDAY AS THE AFOREMENTIONED
FRONT STALLS OVER THE CAROLINAS. THE LATEST MODEL GUIDANCE SUGGESTS
A COASTAL LOW/CAD WEDGE SETUP OVER THE CAROLINAS MID-WEEK...AND THE
POTENTIAL EXISTS FOR AN EXTENDED PERIOD OF MVFR/IFR CONDITIONS LATE
TUE NIGHT INTO THE DAY THU...THOUGH CONFIDENCE REMAINS RELATIVELY
LOW. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...DJF
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
142 PM EDT MON APR 16 2012
.SYNOPSIS...
A COLD FRONT CROSSES THIS EVENING. A WAVE DEVELOPS ALONG THE FRONT
AND SKIRTS THE MOUNTAINS TUESDAY NIGHT THROUGH WEDNESDAY EVENING.
WARMER AFTERNOON TEMPERATURES RETURN FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
130 PM UPDATE...TO REMOVE MENTION OF SEVERE TSTM POTENTIAL THIS
AFTERNOON AS SPC HAS PULLED US OUT OF SLIGHT RISK. THIS IS
REASONABLE GIVEN HI RES MODEL AND SOUNDING TRENDS. HAVE DEPICTED TWO
AREAS TO CONCENTRATE BEST CHANCE OF RASH/TRW THIS AFTERNOON. THE BEST
IS ACROSS THE SOUTH WHERE BETTER MOISTURE POOLING IS...AND SECONDARY
AREA ACROSS THE NORTHWEST WHERE BETTER DYNAMICS ARE. ALSO INCREASED
CLOUDS THIS AFTERNOON PER CURRENT SATELLITE TRENDS.
OTHERWISE...TEMPS LOOK GOOD DESPITE CLOUDS.
10 AM UPDATE. MAIN CHANGE WAS TO INCREASE WIND GUSTS TO 30 TO 40 MPH
THIS AFTERNOON...GIVEN STRONGER WINDS OFF THE SURFACE AND MIXING.
HOWEVER...RELATIVE HUMIDITIES WILL REMAIN HIGH ENOUGH TO PRECLUDE A
FIRE DANGER STATEMENT. CURRENT BAND OF SHOWERS DISSIPATING TO OUR
WEST AS INDICATED BY MODELS. AM CONCERNED ABOUT PROSPECTS OF
REDEVELOPMENT OF STORMS THIS AFTERNOON AHEAD OF FRONT AS SOUNDING
PROFILES LACK DEEPER MOISTURE. BUT WILL KEEP POPS AS IS THIS
AFTERNOON...GIVEN DYNAMICS ARE THERE FOR THAT THIN LINE AHEAD OF THE
FRONT AND SPC STILL HAS US IN A SLIGHT RISK OF SEVERE.
PREVIOUS DISCUSSION BELOW...
TIMING OF FRONT AND PREFRONTAL ACTION LOOKS GOOD FROM PREV FCST.
CONCERNED ABOUT POTENTIAL LACK OF REDEVELOPMENT OF PREFRONTAL BAND
THIS AFTN. MDLS ARE NOT THRILLED WITH BAND LIGHTING BACK UP AS IT
ENTERS WESTERN ZONES BY 18Z. RAPID RUC ALSO LACKLUSTER WITH ITS
MODELED REFLECTIVITY FOR TOMORROW. GIVEN THIS AND STOUT RIDGE
CURRENTLY OVER THE AREA AMID A DRY BL AND THE FACT THIS WILL BE
RACING OUT WELL AHEAD OF ACTUALLY BAROCLINIC ZONE...ELECTED TO
KNOCK DOWN POPS SOME BUT NOT DOWN TO WHAT MDLS SUGGEST. THINKING
OF MORE ISO OR SCT CONCERNING COVERAGE WITH GREATEST COVERAGE
ALONG AND WEST OF OH RVR WITH SUBSEQUENT WEAKENING TOWARD MTNS.
MDL QPF LOOKS MEAGER TO SAY THE LEAST GIVEN LACK OF COVERAGE AND
PROGRESSIVE NATURE. WHAT CONVECTION THAT DOES FORM WILL HAVE TO BE
WATCHED FOR DAMAGING WIND GUSTS AS SPC CONT TO PAINT MUCH
OF CWA IN SLIGHT RISK. AS A RESULT WILL CONT WIND WORDING IN WX GRIDS.
ACTUAL FRONT WILL LAG SEVERAL HRS BEHIND...NOT GETTING INTO SE
OH UNTIL AFTER 00Z...WITH SUBSEQUENT OH RVR CROSSING BY 03Z AND
EXITING MTNS BY 09Z. ELECTED TO HAVE SOME SCHC POPS WITH ACTUAL
FROPA AS ENOUGH FORCING AND MOISTURE MAY EXIST FOR A FEW SHRA.
SHOULD BE WINDY TDY WITH AFTN MIXING AND GRADIENT TIGHTENING.
COULD SEE SOME 25 TO 30KTS GUSTS WITH LCL HIGHER IN ANY CONVECTION
AND WITH FROPA.
CLDS WILL STICK ARND TONIGHT WITH MID/HI LVL MOISTURE ADVECTING IN
FROM SW FLOW ALOFT.
FOR TMPS...LEANED TOWARD WARMER MAV EAST OF OH RVR AND COOLER MET
WEST OF THERE AS CONVECTION WOULD BE FIRING BEFORE MAX HEATING
COULD OCCUR THERE. WILL ALSO GO A HAIR ABV GUIDANCE E AND S FOR
TONIGHT AS BL SLOW TO COOL AND LINGERING CLDS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
GFS/CANADIAN AND ECMWF ARE SHOWING A WAVE DEVELOPING AND SKIRTING
SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA FOR TUESDAY NIGHT
THROUGH WEDNESDAY EVENING. NAM KEEPS THE WAVE SOUTH OF THE
REGION...BUT IS AN OUTLIER. THEREFORE WILL GO WITH A MAJORITY
SOLUTION AND PUSH POPS DEEPER INTO OUR TERRITORY AND INCREASE THEM
IN THE SOUTHEAST. THIS WILL ALSO NECESSITATE LOWERING HIGH
TEMPERATURES ON WEDNESDAY IN THE SOUTHERN AND EASTERN COUNTIES.
CANADIAN/GFS AND ECMWF ARE VERY SIMILAR WITH THE NEXT SYSTEM AS
WELL. THE MODELS WOULD KEEP AN APPROACHING FRONT NORTH OF THE
REGION. WILL KEEP JUST A SMALL POP IN THE NORTH THURSDAY
AFTERNOON...BUT THEN DRY GO THURSDAY NIGHT AS THE FRONT RETREATS
FURTHER NORTH. WITH AREA IN THE WARM SECTOR...WARMED HIGH
TEMPERATURES ON THURSDAY AND FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
QUITE A BIT OF UNCERTAINTY IN THE LONG TERM PERIOD AS MODELS HAVE
RUN TO RUN CONSISTENCY AND OVERALL AGREEMENT ISSUES. BUT GENERAL
CONSENSUS IS THAT A COLD FRONT IN ASSOCIATION WITH A LOW PRESSURE
SYSTEM MOVING EAST THROUGH CANADA WILL STALL OUT SOMEWHERE OVER THE
NORTHERN ZONES LATE THURSDAY/EARLY FRIDAY...WITH A LOW PRESSURE
SYSTEM OUT IN THE PLAINS MOVING NORTHEAST ALONG THE STALLED FRONTAL
BOUNDARY TOWARDS THE REGION FOR THE WEEKEND. THE LOW PRESSURE SYSTEM
AND ASSOCIATED COLD FRONT WILL PUSH EAST THROUGH THE REGION FRIDAY
THROUGH SATURDAY NIGHT...SPREADING SHOWERS AND THUNDERSTORMS INTO
THE REGION. THE LOW WILL MOVE OFF TO THE NORTHEAST ON SUNDAY...WITH
MUCH COOLER AIR FILTERING INTO THE REGION ON THE BACK SIDE OF THE
LOW. ANY LINGERING PRECIPITATION/MOISTURE IN THE NW UPSLOPE FLOW ON
THE BACK SIDE OF THE LOW COULD BE IN THE FORM OF A RAIN/SNOW MIX OR
EVEN SNOW OVER THE NORTHERN MOUNTAIN ZONES AS THE COLDER AIR TAKES
OVER ON THE BACK SIDE OF THE LOW.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
18Z MONDAY THRU 18Z TUESDAY...
PREDOMINATE VFR CEILINGS WILL PREVAIL THROUGH THE PERIOD...WITH
CLEARING ACROSS NORTHWEST HALF EARLY TONIGHT. GUSTY SW WINDS 30 TO
40 KTS THIS AFTERNOON AS A COLD FRONT APPROACHES FROM THE WEST LATE
TDY...DIMINISHING EARLY TONIGHT AS THE COLD FRONT EXITS AND WITH
LOSS OF HEATING AND MIXING.
A LINE OF SCATTERED TO BROKEN SHOWERS AND THUNDERSTORMS MAY MOVE
ACROSS THE AREA ROUGHLY BETWEEN 17Z-00Z AHEAD OF THE FRONT...BEST
CHANCE WILL BE ACROSS THE SOUTH. WILL MINIMIZE THIS IN TAFS. HAVE
SOME TEMPO MVFR VSBY IN ANY TSTM THAT DOES FLARE UP.
AFTER 00Z...AS FRONT MOVES EAST OF AREA SHOWERS BASICALLY END WITH
VFR CONDITIONS PREVAILING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: WIND DIRECTION AND SPEED WILL TEND TO
FLUCTUATE. TIMING OF SHOWERS/THUNDERSTORMS MAY VARY.
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 TUESDAY...
IFR CONDITIONS POSSIBLE TUESDAY NIGHT THROUGH WEDNESDAY EVENING IN
SOUTHWEST VIRGINIA AND THE SOUTHERN WV MOUNTAINS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/JMV/30
NEAR TERM...JMV
SHORT TERM...RPY
LONG TERM...SL
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1239 PM EDT MON APR 16 2012
.SYNOPSIS...
A COLD FRONT OVER NW OHIO WILL MOVE EAST THROUGH THE AREA THIS AFTERNOON
THEN HIGH PRESSURE WILL CROSS THE REGION LATE TUESDAY INTO EARLY
WEDNESDAY. ANOTHER COLD FRONT WILL DROP INTO THE OHIO VALLEY EARLY
THURSDAY AND STALL. LOW PRESSURE WILL MOVE ALONG THE FRONT UP THE
OHIO VALLEY FRIDAY AND TO THE MID ATLANTIC COAST SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT AT 16Z WAS LOCATED FROM NEAR A LINE FROM SANDUSKY TO MARION.
AT THIS POINT THERE ARE NO RADAR RETURNS ALONG OR AHEAD OF THIS
BOUNDARY. THERE STILL MAY BE JUST ENOUGH CONVERGENCE ALONG THE
COLD FRONT AS IT INTERACTS WITH THE UNSTABLE AIR ACROSS THE
EASTERN COUNTY WARNING AREA. IT STILL COULD DEVELOP NEAR OR EAST
OF CANTON TO ASHTABULA LINE BETWEEN 18Z AND 20Z. IF THE THUNDERSTORMS
DO DEVELOP WE WILL HAVE TO MONITOR FOR THE POTENTIAL OF A STRONGER
WIND GUST.
GUSTY SOUTHWEST WINDS WILL BE AN ISSUE THROUGH THE AFTERNOON.
INITIALLY THE LOW LEVEL JET AHEAD OF THE FRONT WILL MIX TO THE
SURFACE AND SHOULD PRODUCE SOME GUSTS THAT ARE AROUND 45 KNOTS.
THESE WINDS WILL REMAIN STRONG IN THE WAKE OF THE FRONT FOR A FEW
HOURS AS THE STRONG PRESSURE RISES MOVE IN BEHIND THE LOW PRESSURE
THAT IS TRACKING THROUGH THE CENTRAL LAKES. SO EXPECT TO SEE GUSTS
IN THE WAKE OF THE FRONT CONTINUE IN THE 45 MPH RANGE. UNCERTAINTY
AT THIS POINT IS WHEN TO DECREASE THE WINDS. FOR NOW THE ADVISORY
TIME ENDING OF 10 PM LOOKS REASONABLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
HIGH PRESSURE BUILDS IN FROM THE WEST TONIGHT SO STRONG WINDS WILL
DIMINISH FROM WEST TO EAST DURING THE EVENING BUT COULD STILL REMAIN
A LITTLE WINDY FOR THE SNOWBELT LAKESHORE INTO THE LATE NIGHT HOURS.
DRY PUNCH OF AIR BEHIND THE COLD FRONT SHIFTS INTO THE EAST DURING
THE EVENING. WRAP MOISTURE TRIES TO SPREAD EAST INTO THE CWA EARLY
TONIGHT BUT SUBSIDENCE WITH HIGH MOVING IN LOOKS TO BE TOO STRONG TO
ALLOW FOR ENOUGH CLOUDINESS TO PRODUCE ANY PRECIP.
HIGH PRESSURE WITH DRY CONDITIONS SHOULD OCCUR INTO WED NIGHT THEN
ANOTHER COLD FRONT WILL MOVE IN BRINGING A THREAT FOR SHRA MAINLY
FOR THE SECOND HALF OF WED NIGHT.
THE QUESTION FOR THU IS WHETHER THE FRONT WILL HAVE ENOUGH MOMENTUM
TO PUSH FAR ENOUGH S TO TAKE THE SHRA THREAT SOUTH OF THE CWA FOR
THU AFTERNOON AND EVENING. LOW PRESSURE WILL MOVE ALONG THE FRONT
AND SPREAD SHRA BACK NORTH OF THE FRONT THU NIGHT. RIGHT NOW MODELS
WANT TO KEEP GOOD DEEP MOISTURE OVER THE CWA LATE THU AND THU NIGHT
SO WILL SIDE WITH CAUTION AND KEEP THREAT FOR SHRA GOING ALL DAY THU
AS WELL AS THU NIGHT.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
ANOTHER COLD FRONT MOVES THROUGH ON FRIDAY WITH A FAIR AMOUNT OF
COLD AIR BEHIND IT. THE LAKE AND 850 MB TEMPERATURE DIFFERENCE WILL
BE NEAR 11 OR 12C. HIGH PRESSURE SLOWLY BUILDS IN FROM THE WEST. THE
GFS AND ECMWF ARE IN FAIR AGREEMENT FRIDAY AND SATURDAY. FOR SUNDAY
THE 00Z ECMWF HANGS UNTO THE PRECIPITATION LONGER IN THE FORECAST
AREA. AT THIS TIME REMAINED CONSISTENT WITH THE PREVIOUS FORECAST
BUT THIS WILL HAVE TO BE WATCHED. TEMPERATURES WILL BE BELOW NORMAL.
THE THREAT OF FROST IS POSSIBLE SATURDAY NIGHT BUT ESPECIALLY SUNDAY
NIGHT IF THE CLOUDS DECREASE AS EXPECTED.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
GUSTY WINDS AND A THREAT OF THUNDER ARE THE WEATHER PROBLEMS FOR
TODAY. THE SHOWERS OVER EASTERN INDIANA AND WESTERN OHIO ARE
DECREASING AS THEY MOVE EAST...THE HRRR MODEL CONCURS WITH THIS.
THE MODELS ARE TRYING TO FORECAST A NARROW SQUALL LINE DEVELOPING AHEAD
OF THE FRONT LATE THIS MORNING AND IT WILL MOVE EAST RAPIDLY. THINGS MAY
BE MOVING QUICKER AND THIS MAY LIMIT THE AMOUNT OF THUNDER AND
SEVERE WEATHER. THE BEST CHANCE FOR THUNDER IS FROM CLE EAST AS
THE AIRMASS WILL GET UNSTABLE ENOUGH. THE 00Z 4KM WRF-NMM HAS TWO
NARROW BANDS OF SHOWERS...ONE MOVES THROUGH BY EARLY AFTERNOON AND
THEN ANOTHER DEVELOPS LATE IN THE AFTERNOON. THE 4KM WRF IS THE
ONLY MODEL SHOWING THIS. ON THE EDGE ABOUT THIS.
THE PRESSURE GRADIENT INCREASED SO MOST PLACES ARE GUSTY...THUS
DECREASING THE THREAT OF SIGNIFICANT LOW LEVEL WIND SHEAR-LLWS.
THE HRRR MODEL INCREASES THE GUSTS AT THE SURFACE IN EXCESS OF 40
KNOTS BY NOON IN THE WARM ADVECTION. GETTING SOME SUNSHINE AT
TIMES WILL HELP. AT DAYBREAK SOME GUSTS TO 35 KNOTS WERE ALREADY
BEING REPORTED. THE WINDS WILL DECREASE AROUND SUNSET.
VFR FOR CLOUDS AND VISIBILITY EXCEPT IN SHOWERS AND THUNDERSTORMS.
HOWEVER...THE SREF IS TRYING TO INDICATE MVFR CEILINGS DEVELOPING
THIS MORNING AND ENDING THIS AFTERNOON. SOME MVFR CEILINGS HAVE
DEVELOPED IN INDIANA...BUT AS THE SHOWERS DECREASE...THE CLOUDS
MAY ALSO. WILL FORECAST SOME MVFR CEILINGS FOR TOL AND FDY.
.OUTLOOK...NON VFR POSSIBLE WEDNESDAY NIGHT INTO FRIDAY.
&&
.MARINE...
STRONG WARM ADVECTION WILL OCCUR THIS MORNING UNTIL THE COLD FRONT
BEGINS MOVING ACROSS LAKE ERIE FROM WEST TO EAST THIS AFTERNOON.
EVEN THOUGH PLENTY OF WARM AIR AND STRONG WINDS ALOFT...SUSTAINED
WINDS OF 20 TO 25 KNOTS WILL BE LIKELY LATER THIS MORNING AND THEN
BEHIND THE FRONT SUSTAINED WINDS OF 30 KNOTS WITH HIGHER GUSTS. SOME
CONCERN THAT ESPECIALLY ON THE EAST END THE WINDS COULD APPROACH
GALE FORCE. THE COLD ADVECTION IS NOT THAT SIGNIFICANT SO WILL
CONTINUE WITH THE 30 KNOTS SUSTAINED AND A SMALL CRAFT ADVISORY. THE
WINDS WILL DECREASE FROM WEST TO EAST TUESDAY AS HIGH PRESSURE
BUILDS IN. UNTIL THAT HAPPENS THE WATER LEVEL ON THE WEST END OF
LAKE ERIE COULD DROP LATE THIS AFTERNOON AND EVENING. AT THIS TIME
IT IS NOT EXPECTED TO DROP TO BELOW THE CRITICAL MARK FOR SAFE
NAVIGATION...THIS WILL BE WATCHED CLOSELY BY THE NEXT SHIFTS.
SOME MINOR THREAT THAT WAVES COULD APPROACH SMALL CRAFT ADVISORY ON
THURSDAY AFTER A COLD FRONTAL PASSAGE. AT THIS TIME 2 TO 4 FOOT
WAVES SEEM TO BE THE HIGHEST.
THE NEXT THREAT OF A SMALL CRAFT ADVISORY WILL BE FRIDAY NIGHT INTO
SUNDAY AS A LOW AND FRONT MOVES NEAR LAKE ERIE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR OHZ003-006>014-
017>023-027>033-036>038-047-089.
PA...WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT TUESDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT TUESDAY FOR LEZ142>146.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...MULLEN
SHORT TERM...ADAMS
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1014 AM EDT MON APR 16 2012
.SYNOPSIS...
A COLD FRONT CROSSES THIS EVENING. A WAVE DEVELOPS ALONG THE FRONT
AND SKIRTS THE MOUNTAINS TUESDAY NIGHT THROUGH WEDNESDAY EVENING.
WARMER AFTERNOON TEMPERATURES RETURN FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE. MAIN CHANGE WAS TO INCREASE WIND GUSTS TO 30 TO 40 MPH
THIS AFTERNOON...GIVEN STRONGER WINDS OFF THE SURFACE AND MIXING.
HOWEVER...RELATIVE HUMIDITIES WILL REMAIN HIGH ENOUGH TO PRECLUDE A
FIRE DANGER STATEMENT. CURRENT BAND OF SHOWERS DISSIPATING TO OUR
WEST AS INDICATED BY MODELS. AM CONCERNED ABOUT PROSPECTS OF
REDEVELOPMENT OF STORMS THIS AFTERNOON AHEAD OF FRONT AS SOUNDING
PROFILES LACK DEEPER MOISTURE. BUT WILL KEEP POPS AS IS THIS
AFTERNOON...GIVEN DYNAMICS ARE THERE FOR THAT THIN LINE AHEAD OF THE
FRONT AND SPC STILL HAS US IN A SLIGHT RISK OF SEVERE.
PREVIOUS DISCUSSION BELOW...
TIMING OF FRONT AND PREFRONTAL ACTION LOOKS GOOD FROM PREV FCST.
CONCERNED ABOUT POTENTIAL LACK OF REDEVELOPMENT OF PREFRONTAL BAND
THIS AFTN. MDLS ARE NOT THRILLED WITH BAND LIGHTING BACK UP AS IT
ENTERS WESTERN ZONES BY 18Z. RAPID RUC ALSO LACKLUSTER WITH ITS
MODELED REFLECTIVITY FOR TOMORROW. GIVEN THIS AND STOUT RIDGE
CURRENTLY OVER THE AREA AMID A DRY BL AND THE FACT THIS WILL BE
RACING OUT WELL AHEAD OF ACTUALLY BAROCLINIC ZONE...ELECTED TO
KNOCK DOWN POPS SOME BUT NOT DOWN TO WHAT MDLS SUGGEST. THINKING
OF MORE ISO OR SCT CONCERNING COVERAGE WITH GREATEST COVERAGE
ALONG AND WEST OF OH RVR WITH SUBSEQUENT WEAKENING TOWARD MTNS.
MDL QPF LOOKS MEAGER TO SAY THE LEAST GIVEN LACK OF COVERAGE AND
PROGRESSIVE NATURE. WHAT CONVECTION THAT DOES FORM WILL HAVE TO BE
WATCHED FOR DAMAGING WIND GUSTS AS SPC CONT TO PAINT MUCH
OF CWA IN SLIGHT RISK. AS A RESULT WILL CONT WIND WORDING IN WX GRIDS.
ACTUAL FRONT WILL LAG SEVERAL HRS BEHIND...NOT GETTING INTO SE
OH UNTIL AFTER 00Z...WITH SUBSEQUENT OH RVR CROSSING BY 03Z AND
EXITING MTNS BY 09Z. ELECTED TO HAVE SOME SCHC POPS WITH ACTUAL
FROPA AS ENOUGH FORCING AND MOISTURE MAY EXIST FOR A FEW SHRA.
SHOULD BE WINDY TDY WITH AFTN MIXING AND GRADIENT TIGHTENING.
COULD SEE SOME 25 TO 30KTS GUSTS WITH LCL HIGHER IN ANY CONVECTION
AND WITH FROPA.
CLDS WILL STICK ARND TONIGHT WITH MID/HI LVL MOISTURE ADVECTING IN
FROM SW FLOW ALOFT.
FOR TMPS...LEANED TOWARD WARMER MAV EAST OF OH RVR AND COOLER MET
WEST OF THERE AS CONVECTION WOULD BE FIRING BEFORE MAX HEATING
COULD OCCUR THERE. WILL ALSO GO A HAIR ABV GUIDANCE E AND S FOR
TONIGHT AS BL SLOW TO COOL AND LINGERING CLDS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
GFS/CANADIAN AND ECMWF ARE SHOWING A WAVE DEVELOPING AND SKIRTING
SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA FOR TUESDAY NIGHT
THROUGH WEDNESDAY EVENING. NAM KEEPS THE WAVE SOUTH OF THE
REGION...BUT IS AN OUTLIER. THEREFORE WILL GO WITH A MAJORITY
SOLUTION AND PUSH POPS DEEPER INTO OUR TERRITORY AND INCREASE THEM
IN THE SOUTHEAST. THIS WILL ALSO NECESSITATE LOWERING HIGH
TEMPERATURES ON WEDNESDAY IN THE SOUTHERN AND EASTERN COUNTIES.
CANADIAN/GFS AND ECMWF ARE VERY SIMILAR WITH THE NEXT SYSTEM AS
WELL. THE MODELS WOULD KEEP AN APPROACHING FRONT NORTH OF THE
REGION. WILL KEEP JUST A SMALL POP IN THE NORTH THURSDAY
AFTERNOON...BUT THEN DRY GO THURSDAY NIGHT AS THE FRONT RETREATS
FURTHER NORTH. WITH AREA IN THE WARM SECTOR...WARMED HIGH
TEMPERATURES ON THURSDAY AND FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
QUITE A BIT OF UNCERTAINTY IN THE LONG TERM PERIOD AS MODELS HAVE
RUN TO RUN CONSISTENCY AND OVERALL AGREEMENT ISSUES. BUT GENERAL
CONSENSUS IS THAT A COLD FRONT IN ASSOCIATION WITH A LOW PRESSURE
SYSTEM MOVING EAST THROUGH CANADA WILL STALL OUT SOMEWHERE OVER THE
NORTHERN ZONES LATE THURSDAY/EARLY FRIDAY...WITH A LOW PRESSURE
SYSTEM OUT IN THE PLAINS MOVING NORTHEAST ALONG THE STALLED FRONTAL
BOUNDARY TOWARDS THE REGION FOR THE WEEKEND. THE LOW PRESSURE SYSTEM
AND ASSOCIATED COLD FRONT WILL PUSH EAST THROUGH THE REGION FRIDAY
THROUGH SATURDAY NIGHT...SPREADING SHOWERS AND THUNDERSTORMS INTO
THE REGION. THE LOW WILL MOVE OFF TO THE NORTHEAST ON SUNDAY...WITH
MUCH COOLER AIR FILTERING INTO THE REGION ON THE BACK SIDE OF THE
LOW. ANY LINGERING PRECIPITATION/MOISTURE IN THE NW UPSLOPE FLOW ON
THE BACK SIDE OF THE LOW COULD BE IN THE FORM OF A RAIN/SNOW MIX OR
EVEN SNOW OVER THE NORTHERN MOUNTAIN ZONES AS THE COLDER AIR TAKES
OVER ON THE BACK SIDE OF THE LOW.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
14Z MONDAY THRU 12Z TUESDAY...
PREDOMINATE VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD.
HOWEVER...BREEZY TO GUSTY SW WINDS 30 TO 40 KTS THIS AFTERNOON AS A
COLD FRONT APPROACHES FROM THE WEST LATE TDY.
A LINE OF SCATTERED TO BROKEN SHOWERS AND THUNDERSTORMS MAY MOVE
ACROSS THE AREA ROUGHLY BETWEEN 17Z-00Z...WEAKENING AS THEY CLOSE IN
ON MTNS. SOME OF THESE STORMS MAY BE STRONG TO SEVERE...WITH STRONG
WINDS. HAVE SOME TEMPO MVFR VSBY IN TSRA FOR MOST SITES EXCEPT IN
MTNS WHERE CONFIDENCE NOT HIGH ON CONVECTION MAINTAINING SIGNIFICANT
COVERAGE...THUS HELD WITH VCTS AND VFR WITH 12Z ISSUANCE.
AFTER 00Z...AS FRONT MOVES EAST OF AREA SHOWERS BASICALLY END WITH
VFR CONDITIONS PREVAILING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: WIND DIRECTION AND SPEED WILL TEND TO
FLUCTUATE. TIMING OF SHOWERS/THUNDERSTORMS MAY VARY.
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 TUESDAY...
IFR CONDITIONS POSSIBLE TUESDAY NIGHT THROUGH WEDNESDAY EVENING IN
SOUTHWEST VIRGINIA AND THE SOUTHERN WV MOUNTAINS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/JMV/30
NEAR TERM...JMV/30
SHORT TERM...RPY
LONG TERM...SL
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
951 AM EDT MON APR 16 2012
.SYNOPSIS...
A COLD FRONT OVER NW OHIO WILL MOVE EAST THROUGH THE AREA THIS AFTERNOON
THEN HIGH PRESSURE WILL CROSS THE REGION LATE TUESDAY INTO EARLY
WEDNESDAY. ANOTHER COLD FRONT WILL DROP INTO THE OHIO VALLEY EARLY
THURSDAY AND STALL. LOW PRESSURE WILL MOVE ALONG THE FRONT UP THE
OHIO VALLEY FRIDAY AND TO THE MID ATLANTIC COAST SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT AT 13Z WAS ABOUT TO MOVE INTO NW OHIO. THERE WERE SOME
ISOLATED SHOWERS AHEAD OF THE BOUNDARY BUT THEY WERE DECREASING IN
COVERAGE AND INTENSITY AS THEY MOVED EASTWARD. CURRENT MODEL RUNS
CONTINUE TO BRING THE FRONT EASTWARD BUT THE AMOUNT OF CONVERGENCE
ALONG IT IS WEAK. STILL BELIEVE THERE WILL BE A NARROW LINE OF
CONVECTION THAT EVENTUALLY REDEVELOPS BUT IT MAY NOT OCCUR UNTIL
IT GETS INTO THE BETTER INSTABILITY THAT WILL OCCUR ACROSS THE
EASTERN HALF OF THE REGION. AT THIS POINT WE WILL GO WITH ISOLATED
TO SCATTERED CONVECTION IN THE ZONES. BEST CHANCES OF ANY SEVERE
THUNDERSTORM WIND GUSTS WILL BE ACROSS THE EASTERN COUNTY WARNING
AREA...LIKELY NEAR OR EAST OF A LINE FROM CANTON TO ASHTABULA.
GUSTY SOUTHWEST WINDS WILL BE AN ISSUE THROUGH THE DAY. INITIALLY
THE LOW LEVEL JET AHEAD OF THE FRONT WILL MIX TO THE SURFACE AND
SHOULD PRODUCE SOME GUSTS THAT ARE AROUND 45 KNOTS. THESE WINDS
WILL REMAIN STRONG IN THE WAKE OF THE FRONT FOR A FEW HOURS AS
THE STRONG PRESSURE RISES MOVE IN BEHIND THE LOW PRESSURE THAT IS
TRACKING THROUGH THE CENTRAL LAKES. SO EXPECT TO SEE GUSTS IN THE
WAKE OF THE FRONT CONTINUE IN THE 45 MPH RANGE. UNCERTAINTY AT
THIS POINT IS WHEN TO DECREASE THE WINDS. FOR NOW THE ADVISORY
TIME ENDING OF 10 PM LOOKS REASONABLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
HIGH PRESSURE BUILDS IN FROM THE WEST TONIGHT SO STRONG WINDS WILL
DIMINISH FROM WEST TO EAST DURING THE EVENING BUT COULD STILL REMAIN
A LITTLE WINDY FOR THE SNOWBELT LAKESHORE INTO THE LATE NIGHT HOURS.
DRY PUNCH OF AIR BEHIND THE COLD FRONT SHIFTS INTO THE EAST DURING
THE EVENING. WRAP MOISTURE TRIES TO SPREAD EAST INTO THE CWA EARLY
TONIGHT BUT SUBSIDENCE WITH HIGH MOVING IN LOOKS TO BE TOO STRONG TO
ALLOW FOR ENOUGH CLOUDINESS TO PRODUCE ANY PRECIP.
HIGH PRESSURE WITH DRY CONDITIONS SHOULD OCCUR INTO WED NIGHT THEN
ANOTHER COLD FRONT WILL MOVE IN BRINGING A THREAT FOR SHRA MAINLY
FOR THE SECOND HALF OF WED NIGHT.
THE QUESTION FOR THU IS WHETHER THE FRONT WILL HAVE ENOUGH MOMENTUM
TO PUSH FAR ENOUGH S TO TAKE THE SHRA THREAT SOUTH OF THE CWA FOR
THU AFTERNOON AND EVENING. LOW PRESSURE WILL MOVE ALONG THE FRONT
AND SPREAD SHRA BACK NORTH OF THE FRONT THU NIGHT. RIGHT NOW MODELS
WANT TO KEEP GOOD DEEP MOISTURE OVER THE CWA LATE THU AND THU NIGHT
SO WILL SIDE WITH CAUTION AND KEEP THREAT FOR SHRA GOING ALL DAY THU
AS WELL AS THU NIGHT.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
ANOTHER COLD FRONT MOVES THROUGH ON FRIDAY WITH A FAIR AMOUNT OF
COLD AIR BEHIND IT. THE LAKE AND 850 MB TEMPERATURE DIFFERENCE WILL
BE NEAR 11 OR 12C. HIGH PRESSURE SLOWLY BUILDS IN FROM THE WEST. THE
GFS AND ECMWF ARE IN FAIR AGREEMENT FRIDAY AND SATURDAY. FOR SUNDAY
THE 00Z ECMWF HANGS UNTO THE PRECIPITATION LONGER IN THE FORECAST
AREA. AT THIS TIME REMAINED CONSISTENT WITH THE PREVIOUS FORECAST
BUT THIS WILL HAVE TO BE WATCHED. TEMPERATURES WILL BE BELOW NORMAL.
THE THREAT OF FROST IS POSSIBLE SATURDAY NIGHT BUT ESPECIALLY SUNDAY
NIGHT IF THE CLOUDS DECREASE AS EXPECTED.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
GUSTY WINDS AND A THREAT OF THUNDER ARE THE WEATHER PROBLEMS FOR
TODAY. THE SHOWERS OVER EASTERN INDIANA AND WESTERN OHIO ARE
DECREASING AS THEY MOVE EAST...THE HRRR MODEL CONCURS WITH THIS.
THE MODELS ARE TRYING TO FORECAST A NARROW SQUALL LINE DEVELOPING AHEAD
OF THE FRONT LATE THIS MORNING AND IT WILL MOVE EAST RAPIDLY. THINGS MAY
BE MOVING QUICKER AND THIS MAY LIMIT THE AMOUNT OF THUNDER AND
SEVERE WEATHER. THE BEST CHANCE FOR THUNDER IS FROM CLE EAST AS
THE AIRMASS WILL GET UNSTABLE ENOUGH. THE 00Z 4KM WRF-NMM HAS TWO
NARROW BANDS OF SHOWERS...ONE MOVES THROUGH BY EARLY AFTERNOON AND
THEN ANOTHER DEVELOPS LATE IN THE AFTERNOON. THE 4KM WRF IS THE
ONLY MODEL SHOWING THIS. ON THE EDGE ABOUT THIS.
THE PRESSURE GRADIENT INCREASED SO MOST PLACES ARE GUSTY...THUS
DECREASING THE THREAT OF SIGNIFICANT LOW LEVEL WIND SHEAR-LLWS.
THE HRRR MODEL INCREASES THE GUSTS AT THE SURFACE IN EXCESS OF 40
KNOTS BY NOON IN THE WARM ADVECTION. GETTING SOME SUNSHINE AT
TIMES WILL HELP. AT DAYBREAK SOME GUSTS TO 35 KNOTS WERE ALREADY
BEING REPORTED. THE WINDS WILL DECREASE AROUND SUNSET.
VFR FOR CLOUDS AND VISIBILITY EXCEPT IN SHOWERS AND THUNDERSTORMS.
HOWEVER...THE SREF IS TRYING TO INDICATE MVFR CEILINGS DEVELOPING
THIS MORNING AND ENDING THIS AFTERNOON. SOME MVFR CEILINGS HAVE
DEVELOPED IN INDIANA...BUT AS THE SHOWERS DECREASE...THE CLOUDS
MAY ALSO. WILL FORECAST SOME MVFR CEILINGS FOR TOL AND FDY.
.OUTLOOK...NON VFR POSSIBLE WEDNESDAY NIGHT INTO FRIDAY.
&&
.MARINE...
STRONG WARM ADVECTION WILL OCCUR THIS MORNING UNTIL THE COLD FRONT
BEGINS MOVING ACROSS LAKE ERIE FROM WEST TO EAST THIS AFTERNOON.
EVEN THOUGH PLENTY OF WARM AIR AND STRONG WINDS ALOFT...SUSTAINED
WINDS OF 20 TO 25 KNOTS WILL BE LIKELY LATER THIS MORNING AND THEN
BEHIND THE FRONT SUSTAINED WINDS OF 30 KNOTS WITH HIGHER GUSTS. SOME
CONCERN THAT ESPECIALLY ON THE EAST END THE WINDS COULD APPROACH
GALE FORCE. THE COLD ADVECTION IS NOT THAT SIGNIFICANT SO WILL
CONTINUE WITH THE 30 KNOTS SUSTAINED AND A SMALL CRAFT ADVISORY. THE
WINDS WILL DECREASE FROM WEST TO EAST TUESDAY AS HIGH PRESSURE
BUILDS IN. UNTIL THAT HAPPENS THE WATER LEVEL ON THE WEST END OF
LAKE ERIE COULD DROP LATE THIS AFTERNOON AND EVENING. AT THIS TIME
IT IS NOT EXPECTED TO DROP TO BELOW THE CRITICAL MARK FOR SAFE
NAVIGATION...THIS WILL BE WATCHED CLOSELY BY THE NEXT SHIFTS.
SOME MINOR THREAT THAT WAVES COULD APPROACH SMALL CRAFT ADVISORY ON
THURSDAY AFTER A COLD FRONTAL PASSAGE. AT THIS TIME 2 TO 4 FOOT
WAVES SEEM TO BE THE HIGHEST.
THE NEXT THREAT OF A SMALL CRAFT ADVISORY WILL BE FRIDAY NIGHT INTO
SUNDAY AS A LOW AND FRONT MOVES NEAR LAKE ERIE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR OHZ003-006>014-
017>023-027>033-036>038-047-089.
PA...WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT TUESDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT TUESDAY FOR LEZ142>146.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...MULLEN
SHORT TERM...ADAMS
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
738 AM EDT MON APR 16 2012
.SYNOPSIS...
A COLD FRONT OVER INDIANA WILL MOVE EAST THROUGH THE AREA LATER
TODAY AND EARLY TONIGHT THEN HIGH PRESSURE WILL CROSS THE REGION
LATE TUESDAY INTO EARLY WEDNESDAY. ANOTHER COLD FRONT WILL DROP INTO
THE OHIO VALLEY EARLY THURSDAY AND STALL. LOW PRESSURE WILL MOVE
ALONG THE FRONT UP THE OHIO VALLEY FRIDAY AND TO THE MID ATLANTIC
COAST SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
INITIAL BAND OF WEAKENING SHRA/ISOLD TSRA SHOULD MOVE INTO THE NW
CO`S OVER THE NEXT HOUR OR TWO THEN PROGRESS EAST INTO MAINLY THE
EASTERN CO`S FOR THE AFTERNOON. WITH DAYTIME HEATING COULD SEE SOME
OF THE STORMS BECOME SEVERE IN THE EAST WITH DAMAGING WINDS AND TO A
LESSER EXTENT POSSIBLE LARGE HAIL OR A BRIEF TORNADO. COVERAGE OF
CONVECTION IN QUESTION SO WILL STAY WITH JUST CHANCE POPS WHICH IS
STILL HIGHER THAN MAV GUIDANCE.
THE WINDS WILL ALSO BE AN ISSUE OUTSIDE OF THE TSRA AS 850 MB WINDS
AT FRONTAL PASSAGE TIME LOOK TO BE 50 TO 55 KNOTS. AFTER
COLLABORATION HAVE DECIDED TO GO WITH WIND ADVISORY VERSUS WIND
WARNING.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
HIGH PRESSURE BUILDS IN FROM THE WEST TONIGHT SO STRONG WINDS WILL
DIMINISH FROM WEST TO EAST DURING THE EVENING BUT COULD STILL REMAIN
A LITTLE WINDY FOR THE SNOWBELT LAKESHORE INTO THE LATE NIGHT HOURS.
DRY PUNCH OF AIR BEHIND THE COLD FRONT SHIFTS INTO THE EAST DURING
THE EVENING. WRAP MOISTURE TRIES TO SPREAD EAST INTO THE CWA EARLY
TONIGHT BUT SUBSIDENCE WITH HIGH MOVING IN LOOKS TO BE TOO STRONG TO
ALLOW FOR ENOUGH CLOUDINESS TO PRODUCE ANY PRECIP.
HIGH PRESSURE WITH DRY CONDITIONS SHOULD OCCUR INTO WED NIGHT THEN
ANOTHER COLD FRONT WILL MOVE IN BRINGING A THREAT FOR SHRA MAINLY
FOR THE SECOND HALF OF WED NIGHT.
THE QUESTION FOR THU IS WHETHER THE FRONT WILL HAVE ENOUGH MOMENTUM
TO PUSH FAR ENOUGH S TO TAKE THE SHRA THREAT SOUTH OF THE CWA FOR
THU AFTERNOON AND EVENING. LOW PRESSURE WILL MOVE ALONG THE FRONT
AND SPREAD SHRA BACK NORTH OF THE FRONT THU NIGHT. RIGHT NOW MODELS
WANT TO KEEP GOOD DEEP MOISTURE OVER THE CWA LATE THU AND THU NIGHT
SO WILL SIDE WITH CAUTION AND KEEP THREAT FOR SHRA GOING ALL DAY THU
AS WELL AS THU NIGHT.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
ANOTHER COLD FRONT MOVES THROUGH ON FRIDAY WITH A FAIR AMOUNT OF
COLD AIR BEHIND IT. THE LAKE AND 850 MB TEMPERATURE DIFFERENCE WILL
BE NEAR 11 OR 12C. HIGH PRESSURE SLOWLY BUILDS IN FROM THE WEST. THE
GFS AND ECMWF ARE IN FAIR AGREEMENT FRIDAY AND SATURDAY. FOR SUNDAY
THE 00Z ECMWF HANGS UNTO THE PRECIPITATION LONGER IN THE FORECAST
AREA. AT THIS TIME REMAINED CONSISTENT WITH THE PREVIOUS FORECAST
BUT THIS WILL HAVE TO BE WATCHED. TEMPERATURES WILL BE BELOW NORMAL.
THE THREAT OF FROST IS POSSIBLE SATURDAY NIGHT BUT ESPECIALLY SUNDAY
NIGHT IF THE CLOUDS DECREASE AS EXPECTED.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
GUSTY WINDS AND A THREAT OF THUNDER ARE THE WEATHER PROBLEMS FOR
TODAY. THE SHOWERS OVER EASTERN INDIANA AND WESTERN OHIO ARE
DECREASING AS THEY MOVE EAST...THE HRRR MODEL CONCURS WITH THIS.
THE MODELS ARE TRYING TO FORECAST A NARROW SQUALL LINE DEVELOPING AHEAD
OF THE FRONT LATE THIS MORNING AND IT WILL MOVE EAST RAPIDLY. THINGS MAY
BE MOVING QUICKER AND THIS MAY LIMIT THE AMOUNT OF THUNDER AND
SEVERE WEATHER. THE BEST CHANCE FOR THUNDER IS FROM CLE EAST AS
THE AIRMASS WILL GET UNSTABLE ENOUGH. THE 00Z 4KM WRF-NMM HAS TWO
NARROW BANDS OF SHOWERS...ONE MOVES THROUGH BY EARLY AFTERNOON AND
THEN ANOTHER DEVELOPS LATE IN THE AFTERNOON. THE 4KM WRF IS THE
ONLY MODEL SHOWING THIS. ON THE EDGE ABOUT THIS.
THE PRESSURE GRADIENT INCREASED SO MOST PLACES ARE GUSTY...THUS
DECREASING THE THREAT OF SIGNIFICANT LOW LEVEL WIND SHEAR-LLWS.
THE HRRR MODEL INCREASES THE GUSTS AT THE SURFACE IN EXCESS OF 40
KNOTS BY NOON IN THE WARM ADVECTION. GETTING SOME SUNSHINE AT
TIMES WILL HELP. AT DAYBREAK SOME GUSTS TO 35 KNOTS WERE ALREADY
BEING REPORTED. THE WINDS WILL DECREASE AROUND SUNSET.
VFR FOR CLOUDS AND VISIBILITY EXCEPT IN SHOWERS AND THUNDERSTORMS.
HOWEVER...THE SREF IS TRYING TO INDICATE MVFR CEILINGS DEVELOPING
THIS MORNING AND ENDING THIS AFTERNOON. SOME MVFR CEILINGS HAVE
DEVELOPED IN INDIANA...BUT AS THE SHOWERS DECREASE...THE CLOUDS
MAY ALSO. WILL FORECAST SOME MVFR CEILINGS FOR TOL AND FDY.
.OUTLOOK...NON VFR POSSIBLE WEDNESDAY NIGHT INTO FRIDAY.
&&
.MARINE...
STRONG WARM ADVECTION WILL OCCUR THIS MORNING UNTIL THE COLD FRONT
BEGINS MOVING ACROSS LAKE ERIE FROM WEST TO EAST THIS AFTERNOON.
EVEN THOUGH PLENTY OF WARM AIR AND STRONG WINDS ALOFT...SUSTAINED
WINDS OF 20 TO 25 KNOTS WILL BE LIKELY LATER THIS MORNING AND THEN
BEHIND THE FRONT SUSTAINED WINDS OF 30 KNOTS WITH HIGHER GUSTS. SOME
CONCERN THAT ESPECIALLY ON THE EAST END THE WINDS COULD APPROACH
GALE FORCE. THE COLD ADVECTION IS NOT THAT SIGNIFICANT SO WILL
CONTINUE WITH THE 30 KNOTS SUSTAINED AND A SMALL CRAFT ADVISORY. THE
WINDS WILL DECREASE FROM WEST TO EAST TUESDAY AS HIGH PRESSURE
BUILDS IN. UNTIL THAT HAPPENS THE WATER LEVEL ON THE WEST END OF
LAKE ERIE COULD DROP LATE THIS AFTERNOON AND EVENING. AT THIS TIME
IT IS NOT EXPECTED TO DROP TO BELOW THE CRITICAL MARK FOR SAFE
NAVIGATION...THIS WILL BE WATCHED CLOSELY BY THE NEXT SHIFTS.
SOME MINOR THREAT THAT WAVES COULD APPROACH SMALL CRAFT ADVISORY ON
THURSDAY AFTER A COLD FRONTAL PASSAGE. AT THIS TIME 2 TO 4 FOOT
WAVES SEEM TO BE THE HIGHEST.
THE NEXT THREAT OF A SMALL CRAFT ADVISORY WILL BE FRIDAY NIGHT INTO
SUNDAY AS A LOW AND FRONT MOVES NEAR LAKE ERIE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR OHZ003-006>014-
017>023-027>033-036>038-047-089.
PA...WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT TUESDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT TUESDAY FOR LEZ142>146.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS
SHORT TERM...ADAMS
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
612 AM EDT MON APR 16 2012
.SYNOPSIS...
A COLD FRONT OVER INDIANA WILL MOVE EAST THROUGH THE AREA LATER
TODAY AND EARLY TONIGHT THEN HIGH PRESSURE WILL CROSS THE REGION
LATE TUESDAY INTO EARLY WEDNESDAY. ANOTHER COLD FRONT WILL DROP INTO
THE OHIO VALLEY EARLY THURSDAY AND STALL. LOW PRESSURE WILL MOVE
ALONG THE FRONT UP THE OHIO VALLEY FRIDAY AND TO THE MID ATLANTIC
COAST SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM MONDAY EVENING/...
INITIAL BAND OF WEAKENING SHRA/ISOLD TSRA SHOULD MOVE INTO THE NW
CO`S OVER THE NEXT HOUR OR TWO THEN PROGRESS EAST INTO MAINLY THE
EASTERN CO`S FOR THE AFTERNOON. WITH DAYTIME HEATING COULD SEE SOME
OF THE STORMS BECOME SEVERE IN THE EAST WITH DAMAGING WINDS AND TO A
LESSER EXTENT POSSIBLE LARGE HAIL OR A BRIEF TORNADO. COVERAGE OF
CONVECTION IN QUESTION SO WILL STAY WITH JUST CHANCE POPS WHICH IS
STILL HIGHER THAN MAV GUIDANCE.
THE WINDS WILL ALSO BE AN ISSUE OUTSIDE OF THE TSRA AS 850 MB WINDS
AT FRONTAL PASSAGE TIME LOOK TO BE 50 TO 55 KNOTS. AFTER
COLLABORATION HAVE DECIDED TO GO WITH WIND ADVISORY VERSUS WIND
WARNING.
&&
.SHORT TERM /6 PM MONDAY EVENING THROUGH THURSDAY NIGHT/...
HIGH PRESSURE BUILDS IN FROM THE WEST TONIGHT SO STRONG WINDS WILL
DIMINISH FROM WEST TO EAST DURING THE EVENING BUT COULD STILL REMAIN
A LITTLE WINDY FOR THE SNOWBELT LAKESHORE INTO THE LATE NIGHT HOURS.
DRY PUNCH OF AIR BEHIND THE COLD FRONT SHIFTS INTO THE EAST DURING
THE EVENING. WRAP MOISTURE TRIES TO SPREAD EAST INTO THE CWA EARLY
TONIGHT BUT SUBSIDENCE WITH HIGH MOVING IN LOOKS TO BE TOO STRONG TO
ALLOW FOR ENOUGH CLOUDINESS TO PRODUCE ANY PRECIP.
HIGH PRESSURE WITH DRY CONDITIONS SHOULD OCCUR INTO WED NIGHT THEN
ANOTHER COLD FRONT WILL MOVE IN BRINGING A THREAT FOR SHRA MAINLY
FOR THE SECOND HALF OF WED NIGHT.
THE QUESTION FOR THU IS WHETHER THE FRONT WILL HAVE ENOUGH MOMENTUM
TO PUSH FAR ENOUGH S TO TAKE THE SHRA THREAT SOUTH OF THE CWA FOR
THU AFTERNOON AND EVENING. LOW PRESSURE WILL MOVE ALONG THE FRONT
AND SPREAD SHRA BACK NORTH OF THE FRONT THU NIGHT. RIGHT NOW MODELS
WANT TO KEEP GOOD DEEP MOISTURE OVER THE CWA LATE THU AND THU NIGHT
SO WILL SIDE WITH CAUTION AND KEEP THREAT FOR SHRA GOING ALL DAY THU
AS WELL AS THU NIGHT.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
ANOTHER COLD FRONT MOVES THROUGH ON FRIDAY WITH A FAIR AMOUNT OF
COLD AIR BEHIND IT. THE LAKE AND 850 MB TEMPERATURE DIFFERENCE WILL
BE NEAR 11 OR 12C. HIGH PRESSURE SLOWLY BUILDS IN FROM THE WEST. THE
GFS AND ECMWF ARE IN FAIR AGREEMENT FRIDAY AND SATURDAY. FOR SUNDAY
THE 00Z ECMWF HANGS UNTO THE PRECIPITATION LONGER IN THE FORECAST
AREA. AT THIS TIME REMAINED CONSISTENT WITH THE PREVIOUS FORECAST
BUT THIS WILL HAVE TO BE WATCHED. TEMPERATURES WILL BE BELOW NORMAL.
THE THREAT OF FROST IS POSSIBLE SATURDAY NIGHT BUT ESPECIALLY SUNDAY
NIGHT IF THE CLOUDS DECREASE AS EXPECTED.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
GUSTY WINDS AND A THREAT OF THUNDER ARE THE WEATHER PROBLEMS FOR
TODAY. THE SHOWERS AND THUNDERSTORMS OVER INDIANA AND ILLINOIS ARE
DECREASING...HRRR MODEL CONCURS WITH THIS. A NARROW SQUALL LINE
DEVELOPS AHEAD OF THE FRONT LATE THIS MORNING AND MOVES EAST. THE
BEST CHANCE FOR THUNDER IS FROM CLE AND MFD EAST AS THE AIRMASS
WILL GET UNSTABLE ENOUGH.
THE PRESSURE GRADIENT WILL INCREASE DURING THE EARLY MORNING HOURS
AS THE WINDS ALOFT AT 925 MB AND 850 MB INCREASE IN EXCESS OF 50
KNOTS. AS THE WINDS AS THE SURFACE BECOME GUSTY THIS SHOULD
DECREASE THE THREAT OF LLWS. THE HRRR MODEL INCREASES THE GUSTS AT
THE SURFACE IN EXCESS OF 40 KNOTS BY NOON IN THE WARM ADVECTION.
IF WE CAN GET SOME SUNSHINE AND WE SHOULD THAT MAY BE OK. THE
WINDS WILL DECREASE AROUND SUNSET.
VFR FOR CLOUDS AND VISIBILITY EXCEPT IN SHOWERS AND THUNDERSTORMS.
HOWEVER...THE SREF IS TRYING TO INDICATE MVFR CEILINGS DEVELOPING
THIS MORNING AND ENDING THIS AFTERNOON. NOT REAL SURE OF
THIS...WILL NOT FORECAST IT ATTM.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE LATE MONDAY NIGHT INTO
TUESDAY AND THEN AGAIN WEDNESDAY NIGHT INTO FRIDAY.
&&
.MARINE...
STRONG WARM ADVECTION WILL OCCUR THIS MORNING UNTIL THE COLD FRONT
BEGINS MOVING ACROSS LAKE ERIE FROM WEST TO EAST THIS AFTERNOON.
EVEN THOUGH PLENTY OF WARM AIR AND STRONG WINDS ALOFT...SUSTAINED
WINDS OF 20 TO 25 KNOTS WILL BE LIKELY LATER THIS MORNING AND THEN
BEHIND THE FRONT SUSTAINED WINDS OF 30 KNOTS WITH HIGHER GUSTS. SOME
CONCERN THAT ESPECIALLY ON THE EAST END THE WINDS COULD APPROACH
GALE FORCE. THE COLD ADVECTION IS NOT THAT SIGNIFICANT SO WILL
CONTINUE WITH THE 30 KNOTS SUSTAINED AND A SMALL CRAFT ADVISORY. THE
WINDS WILL DECREASE FROM WEST TO EAST TUESDAY AS HIGH PRESSURE
BUILDS IN. UNTIL THAT HAPPENS THE WATER LEVEL ON THE WEST END OF
LAKE ERIE COULD DROP LATE THIS AFTERNOON AND EVENING. AT THIS TIME
IT IS NOT EXPECTED TO DROP TO BELOW THE CRITICAL MARK FOR SAFE
NAVIGATION...THIS WILL BE WATCHED CLOSELY BY THE NEXT SHIFTS.
SOME MINOR THREAT THAT WAVES COULD APPROACH SMALL CRAFT ADVISORY ON
THURSDAY AFTER A COLD FRONTAL PASSAGE. AT THIS TIME 2 TO 4 FOOT
WAVES SEEM TO BE THE HIGHEST.
THE NEXT THREAT OF A SMALL CRAFT ADVISORY WILL BE FRIDAY NIGHT INTO
SUNDAY AS A LOW AND FRONT MOVES NEAR LAKE ERIE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY FROM 10 AM THIS MORNING TO 10 PM EDT THIS
EVENING FOR OHZ003-006>014-017>023-027>033-036>038-047-
089.
PA...WIND ADVISORY FROM 10 AM THIS MORNING TO 10 PM EDT THIS
EVENING FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 4 PM
EDT TUESDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 10 AM EDT
TUESDAY FOR LEZ142>146.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS
SHORT TERM...ADAMS
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
349 AM EDT MON APR 16 2012
.SYNOPSIS...
A COLD FRONT CROSSES LATE TODAY. A WAVE DEVELOPS ALONG THE FRONT AND
MAY SKIRT THE REGION TUESDAY NIGHT THROUGH WEDNESDAY EVENING. WARMER
AFTERNOON TEMPERATURES RETURN FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
TIMING OF FRONT AND PREFRONTAL ACTION LOOKS GOOD FROM PREV FCST.
CONCERNED ABOUT POTENTIAL LACK OF REDEVELOPMENT OF PREFRONTAL BAND
THIS AFTN. MDLS ARE NOT THRILLED WITH BAND LIGHTING BACK UP AS IT
ENTERS WESTERN ZONES BY 18Z. RAPID RUC ALSO LACKLUSTER WITH ITS
MODELED REFLECTIVITY FOR TOMORROW. GIVEN THIS AND STOUT RIDGE
CURRENTLY OVER THE AREA AMID A DRY BL AND THE FACT THIS WILL BE
RACING OUT WELL AHEAD OF ACTUALLY BAROCLINIC ZONE...ELECTED TO
KNOCK DOWN POPS SOME BUT NOT DOWN TO WHAT MDLS SUGGEST. THINKING
OF MORE ISO OR SCT CONCERNING COVERAGE WITH GREATEST COVERAGE
ALONG AND WEST OF OH RVR WITH SUBSEQUENT WEAKENING TOWARD MTNS.
MDL QPF LOOKS MEAGER TO SAY THE LEAST GIVEN LACK OF COVERAGE AND
PROGRESSIVE NATURE. WHAT CONVECTION THAT DOES FORM WILL HAVE TO BE
WATCHED FOR DAMAGING WIND GUSTS AS SPC CONT TO PAINT MUCH
OF CWA IN SLIGHT RISK. AS A RESULT WILL CONT WIND WORDING IN WX GRIDS.
ACTUAL FRONT WILL LAG SEVERAL HRS BEHIND...NOT GETTING INTO SE
OH UNTIL AFTER 00Z...WITH SUBSEQUENT OH RVR CROSSING BY 03Z AND
EXITING MTNS BY 09Z. ELECTED TO HAVE SOME SCHC POPS WITH ACTUAL
FROPA AS ENOUGH FORCING AND MOISTURE MAY EXIST FOR A FEW SHRA.
SHOULD BE WINDY TDY WITH AFTN MIXING AND GRADIENT TIGHTENING.
COULD SEE SOME 25 TO 30KTS GUSTS WITH LCL HIGHER IN ANY CONVECTION
AND WITH FROPA.
CLDS WILL STICK ARND TONIGHT WITH MID/HI LVL MOISTURE ADVECTING IN
FROM SW FLOW ALOFT.
FOR TMPS...LEANED TOWARD WARMER MAV EAST OF OH RVR AND COOLER MET
WEST OF THERE AS CONVECTION WOULD BE FIRING BEFORE MAX HEATING
COULD OCCUR THERE. WILL ALSO GO A HAIR ABV GUIDANCE E AND S FOR
TONIGHT AS BL SLOW TO COOL AND LINGERING CLDS.
WILL BE DECIDING ON ANY FIRE SPS SHORTLY FOR TDY. DWPTS MAY KEEP
RH VALUES OUT OF 20S...HOWEVER ENOUGH MIXING MAY OCCUR TO SEND
DWPTS LWR THAN GUIDANCE SUGGESTS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
GFS/CANADIAN AND ECMWF ARE SHOWING A WAVE DEVELOPING AND SKIRTING
SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA FOR TUESDAY NIGHT
THROUGH WEDNESDAY EVENING. NAM KEEPS THE WAVE SOUTH OF THE
REGION...BUT IS AN OUTLIER. THEREFORE WILL GO WITH A MAJORITY
SOLUTION AND PUSH POPS DEEPER INTO OUR TERRITORY AND INCREASE THEM
IN THE SOUTHEAST. THIS WILL ALSO NECESSITATE LOWERING HIGH
TEMPERATURES ON WEDNESDAY IN THE SOUTHERN AND EASTERN COUNTIES.
CANADIAN/GFS AND ECMWF ARE VERY SIMILAR WITH THE NEXT SYSTEM AS
WELL. THE MODELS WOULD KEEP AN APPROACHING FRONT NORTH OF THE
REGION. WILL KEEP JUST A SMALL POP IN THE NORTH THURSDAY
AFTERNOON...BUT THEN DRY GO THURSDAY NIGHT AS THE FRONT RETREATS
FURTHER NORTH. WITH AREA IN THE WARM SECTOR...WARMED HIGH
TEMPERATURES ON THURSDAY AND FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
QUITE A BIT OF UNCERTAINTY IN THE LONG TERM PERIOD AS MODELS HAVE
RUN TO RUN CONSISTENCY AND OVERALL AGREEMENT ISSUES. BUT GENERAL
CONSENSUS IS THAT A COLD FRONT IN ASSOCIATION WITH A LOW PRESSURE
SYSTEM MOVING EAST THROUGH CANADA WILL STALL OUT SOMEWHERE OVER THE
NORTHERN ZONES LATE THURSDAY/EARLY FRIDAY...WITH A LOW PRESSURE
SYSTEM OUT IN THE PLAINS MOVING NORTHEAST ALONG THE STALLED FRONTAL
BOUNDARY TOWARDS THE REGION FOR THE WEEKEND. THE LOW PRESSURE SYSTEM
AND ASSOCIATED COLD FRONT WILL PUSH EAST THROUGH THE REGION FRIDAY
THROUGH SATURDAY NIGHT...SPREADING SHOWERS AND THUNDERSTORMS INTO
THE REGION. THE LOW WILL MOVE OFF TO THE NORTHEAST ON SUNDAY...WITH
MUCH COOLER AIR FILTERING INTO THE REGION ON THE BACK SIDE OF THE
LOW. ANY LINGERING PRECIPITATION/MOISTURE IN THE NW UPSLOPE FLOW ON
THE BACK SIDE OF THE LOW COULD BE IN THE FORM OF A RAIN/SNOW MIX OR
EVEN SNOW OVER THE NORTHERN MOUNTAIN ZONES AS THE COLDER AIR TAKES
OVER ON THE BACK SIDE OF THE LOW.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. HOWEVER...BREEZY
TO GUSTY SW WINDS GENERALLY AROUND THE 20G30KT RANGE WILL CONTINUE
AS WELL THROUGH THE PERIOD AS A COLD FRONT APPROACHES FROM THE
WEST LATE TDY. LLJ 40 TO 50KTS ACROSS THE AREA WARRANT CARRYING
LLWS UNTIL 12Z WHEN MORE GUSTINESS SHOULD KICK IN WITH BETTER
MIXING AFTER SUNRISE.
A BKN LINE OF SHOWERS AND THUNDERSTORMS IS EXPECTED TO MOVE
ACROSS THE AREA ROUGHLY BETWEEN 18Z- 00Z...WEAKENING AS THEY CLOSE
IN ON MTNS. SOME OF THESE STORMS MAY BE STRONG TO SEVERE...WITH
STRONG WINDS. MVFR/LCL IFR IN CONVECTION BUT HAVE KEPT OUT OF TAFS
ATTM DUE TO UNCERTAINTY IN COVERAGE AND OUTSIDE OF TEMPO TIME
FRAME.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: WIND DIRECTION AND SPEED WILL TEND TO
FLUCTUATE. TIMING OF SHOWERS/THUNDERSTORMS MAY VARY.
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 MON 04/16/12
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 M 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 M H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z TUESDAY...
IFR CONDITIONS POSSIBLE TUESDAY NIGHT THROUGH WEDNESDAY EVENING IN
SOUTHWEST VIRGINIA AND THE SOUTHERN WV MOUNTAINS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...SL
AVIATION...
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
333 AM EDT MON APR 16 2012
.SYNOPSIS...
A COLD FRONT OVER INDIANA WILL MOVE EAST THROUGH THE AREA LATER
TODAY AND EARLY TONIGHT THEN HIGH PRESSURE WILL CROSS THE REGION
LATE TUESDAY INTO EARLY WEDNESDAY. ANOTHER COLD FRONT WILL DROP INTO
THE OHIO VALLEY EARLY THURSDAY AND STALL. LOW PRESSURE WILL MOVE
ALONG THE FRONT UP THE OHIO VALLEY FRIDAY AND TO THE MID ATLANTIC
COAST SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM MONDAY EVENING/...
INITIAL BAND OF WEAKENING SHRA/ISOLD TSRA SHOULD MOVE INTO THE NW
CO`S TOWARD DAYBREAK THEN PROGRESS EAST INTO MAINLY THE EASTERN CO`S
FOR THE AFTERNOON. WITH DAYTIME HEATING COULD SEE SOME OF THE STORMS
BECOME SEVERE IN THE EAST WITH DAMAGING WINDS AND TO A LESSER EXTENT
POSSIBLE LARGE HAIL OR A BRIEF TORNADO. COVERAGE OF CONVECTION IN
QUESTION SO WILL STAY WITH JUST CHANCE POPS WHICH IS STILL HIGHER
THAN MAV GUIDANCE.
THE WINDS WILL ALSO BE AN ISSUE OUTSIDE OF THE TSRA AS 850 MB WINDS
AT FRONTAL PASSAGE TIME LOOK TO BE 50 TO 55 KNOTS. AFTER
COLLABORATION HAVE DECIDED TO GO WITH WIND ADVISORY VERSUS WIND
WARNING.
&&
.SHORT TERM /6 PM MONDAY EVENING THROUGH THURSDAY NIGHT/...
HIGH PRESSURE BUILDS IN FROM THE WEST TONIGHT SO STRONG WINDS WILL
DIMINISH FROM WEST TO EAST DURING THE EVENING BUT COULD STILL REMAIN
A LITTLE WINDY FOR THE SNOWBELT LAKESHORE INTO THE LATE NIGHT HOURS.
DRY PUNCH OF AIR BEHIND THE COLD FRONT SHIFTS INTO THE EAST DURING
THE EVENING. WRAP MOISTURE TRIES TO SPREAD EAST INTO THE CWA EARLY
TONIGHT BUT SUBSIDENCE WITH HIGH MOVING IN LOOKS TO BE TOO STRONG TO
ALLOW FOR ENOUGH CLOUDINESS TO PRODUCE ANY PRECIP.
HIGH PRESSURE WITH DRY CONDITIONS SHOULD OCCUR INTO WED NIGHT THEN
ANOTHER COLD FRONT WILL MOVE IN BRINGING A THREAT FOR SHRA MAINLY
FOR THE SECOND HALF OF WED NIGHT.
THE QUESTION FOR THU IS WHETHER THE FRONT WILL HAVE ENOUGH MOMENTUM
TO PUSH FAR ENOUGH S TO TAKE THE SHRA THREAT SOUTH OF THE CWA FOR
THU AFTERNOON AND EVENING. LOW PRESSURE WILL MOVE ALONG THE FRONT
AND SPREAD SHRA BACK NORTH OF THE FRONT THU NIGHT. RIGHT NOW MODELS
WANT TO KEEP GOOD DEEP MOISTURE OVER THE CWA LATE THU AND THU NIGHT
SO WILL SIDE WITH CAUTION AND KEEP THREAT FOR SHRA GOING ALL DAY THU
AS WELL AS THU NIGHT.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
ANOTHER COLD FRONT MOVES THROUGH ON FRIDAY WITH A FAIR AMOUNT OF
COLD AIR BEHIND IT. THE LAKE AND 850 MB TEMPERATURE DIFFERENCE WILL
BE NEAR 11 OR 12C. HIGH PRESSURE SLOWLY BUILDS IN FROM THE WEST. THE
GFS AND ECMWF ARE IN FAIR AGREEMENT FRIDAY AND SATURDAY. FOR SUNDAY
THE 00Z ECMWF HANGS UNTO THE PRECIPITATION LONGER IN THE FORECAST
AREA. AT THIS TIME REMAINED CONSISTENT WITH THE PREVIOUS FORECAST
BUT THIS WILL HAVE TO BE WATCHED. TEMPERATURES WILL BE BELOW NORMAL.
THE THREAT OF FROST IS POSSIBLE SATURDAY NIGHT BUT ESPECIALLY SUNDAY
NIGHT IF THE CLOUDS DECREASE AS EXPECTED.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
GUSTY WINDS AND A THREAT OF THUNDER ARE THE WEATHER PROBLEMS FOR
TODAY. THE SHOWERS AND THUNDERSTORMS OVER INDIANA AND ILLINOIS ARE
DECREASING...HRRR MODEL CONCURS WITH THIS. A NARROW SQUALL LINE
DEVELOPS AHEAD OF THE FRONT LATE THIS MORNING AND MOVES EAST. THE
BEST CHANCE FOR THUNDER IS FROM CLE AND MFD EAST AS THE AIRMASS
WILL GET UNSTABLE ENOUGH.
THE PRESSURE GRADIENT WILL INCREASE DURING THE EARLY MORNING HOURS
AS THE WINDS ALOFT AT 925 MB AND 850 MB INCREASE IN EXCESS OF 50
KNOTS. AS THE WINDS AS THE SURFACE BECOME GUSTY THIS SHOULD
DECREASE THE THREAT OF LLWS. THE HRRR MODEL INCREASES THE GUSTS AT
THE SURFACE IN EXCESS OF 40 KNOTS BY NOON IN THE WARM ADVECTION.
IF WE CAN GET SOME SUNSHINE AND WE SHOULD THAT MAY BE OK. THE
WINDS WILL DECREASE AROUND SUNSET.
VFR FOR CLOUDS AND VISIBILITY EXCEPT IN SHOWERS AND THUNDERSTORMS.
HOWEVER...THE SREF IS TRYING TO INDICATE MVFR CEILINGS DEVELOPING
THIS MORNING AND ENDING THIS AFTERNOON. NOT REAL SURE OF
THIS...WILL NOT FORECAST IT ATTM.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE LATE MONDAY NIGHT INTO
TUESDAY AND THEN AGAIN WEDNESDAY NIGHT INTO FRIDAY.
&&
.MARINE...
STRONG WARM ADVECTION WILL OCCUR THIS MORNING UNTIL THE COLD FRONT
BEGINS MOVING ACROSS LAKE ERIE FROM WEST TO EAST THIS AFTERNOON.
EVEN THOUGH PLENTY OF WARM AIR AND STRONG WINDS ALOFT...SUSTAINED
WINDS OF 20 TO 25 KNOTS WILL BE LIKELY LATER THIS MORNING AND THEN
BEHIND THE FRONT SUSTAINED WINDS OF 30 KNOTS WITH HIGHER GUSTS. SOME
CONCERN THAT ESPECIALLY ON THE EAST END THE WINDS COULD APPROACH
GALE FORCE. THE COLD ADVECTION IS NOT THAT SIGNIFICANT SO WILL
CONTINUE WITH THE 30 KNOTS SUSTAINED AND A SMALL CRAFT ADVISORY. THE
WINDS WILL DECREASE FROM WEST TO EAST TUESDAY AS HIGH PRESSURE
BUILDS IN. UNTIL THAT HAPPENS THE WATER LEVEL ON THE WEST END OF
LAKE ERIE COULD DROP LATE THIS AFTERNOON AND EVENING. AT THIS TIME
IT IS NOT EXPECTED TO DROP TO BELOW THE CRITICAL MARK FOR SAFE
NAVIGATION...THIS WILL BE WATCHED CLOSELY BY THE NEXT SHIFTS.
SOME MINOR THREAT THAT WAVES COULD APPROACH SMALL CRAFT ADVISORY ON
THURSDAY AFTER A COLD FRONTAL PASSAGE. AT THIS TIME 2 TO 4 FOOT
WAVES SEEM TO BE THE HIGHEST.
THE NEXT THREAT OF A SMALL CRAFT ADVISORY WILL BE FRIDAY NIGHT INTO
SUNDAY AS A LOW AND FRONT MOVES NEAR LAKE ERIE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY FROM 10 AM THIS MORNING TO 10 PM EDT THIS
EVENING FOR OHZ003-006>014-017>023-027>033-036>038-047-
089.
PA...WIND ADVISORY FROM 10 AM THIS MORNING TO 10 PM EDT THIS
EVENING FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 4 PM
EDT TUESDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 10 AM EDT
TUESDAY FOR LEZ142>146.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS
SHORT TERM...ADAMS
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
313 AM EDT MON APR 16 2012
.SYNOPSIS...
A COLD FRONT CROSSES LATE TODAY. WEAK UPPER LEVEL DISTURBANCE PASSES
TUESDAY AND TUESDAY NIGHT. HIGH PRESSURE FOLLOWS THROUGH THE END
OF WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
TIMING OF FRONT AND PREFRONTAL ACTION LOOKS GOOD FROM PREV FCST.
CONCERNED ABOUT POTENTIAL LACK OF REDEVELOPMENT OF PREFRONTAL BAND
THIS AFTN. MDLS ARE NOT THRILLED WITH BAND LIGHTING BACK UP AS IT
ENTERS WESTERN ZONES BY 18Z. RAPID RUC ALSO LACKLUSTER WITH ITS
MODELED REFLECTIVITY FOR TOMORROW. GIVEN THIS AND STOUT RIDGE
CURRENTLY OVER THE AREA AMID A DRY BL AND THE FACT THIS WILL BE
RACING OUT WELL AHEAD OF ACTUALLY BAROCLINIC ZONE...ELECTED TO
KNOCK DOWN POPS SOME BUT NOT DOWN TO WHAT MDLS SUGGEST. THINKING
OF MORE ISO OR SCT CONCERNING COVERAGE WITH GREATEST COVERAGE
ALONG AND WEST OF OH RVR WITH SUBSEQUENT WEAKENING TOWARD MTNS.
MDL QPF LOOKS MEAGER TO SAY THE LEAST GIVEN LACK OF COVERAGE AND
PROGRESSIVE NATURE. WHAT CONVECTION THAT DOES FORM WILL HAVE TO BE
WATCHED FOR DAMAGING WIND GUSTS AS SPC CONT TO PAINT MUCH
OF CWA IN SLIGHT RISK. AS A RESULT WILL CONT WIND WORDING IN WX GRIDS.
ACTUAL FRONT WILL LAG SEVERAL HRS BEHIND...NOT GETTING INTO SE
OH UNTIL AFTER 00Z...WITH SUBSEQUENT OH RVR CROSSING BY 03Z AND
EXITING MTNS BY 09Z. ELECTED TO HAVE SOME SCHC POPS WITH ACTUAL
FROPA AS ENOUGH FORCING AND MOISTURE MAY EXIST FOR A FEW SHRA.
SHOULD BE WINDY TDY WITH AFTN MIXING AND GRADIENT TIGHTENING.
COULD SEE SOME 25 TO 30KTS GUSTS WITH LCL HIGHER IN ANY CONVECTION
AND WITH FROPA.
CLDS WILL STICK ARND TONIGHT WITH MID/HI LVL MOISTURE ADVECTING IN
FROM SW FLOW ALOFT.
FOR TMPS...LEANED TOWARD WARMER MAV EAST OF OH RVR AND COOLER MET
WEST OF THERE AS CONVECTION WOULD BE FIRING BEFORE MAX HEATING
COULD OCCUR THERE. WILL ALSO GO A HAIR ABV GUIDANCE E AND S FOR
TONIGHT AS BL SLOW TO COOL AND LINGERING CLDS.
WILL BE DECIDING ON ANY FIRE SPS SHORTLY FOR TDY. DWPTS MAY KEEP
RH VALUES OUT OF 20S...HOWEVER ENOUGH MIXING MAY OCCUR TO SEND
DWPTS LWR THAN GUIDANCE SUGGESTS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
CONTINUED WITH CONVECTION ASSOCIATED WITH COLD
FRONT...DIMINISHING IN INTENSITY AS FRONT EXITS THE EASTERN
MOUNTAINS LATE MONDAY NIGHT. GOOD AGREEMENT AND CONSISTENCY AMONG
MODELS LET US HAVE GOOD CONFIDENCE WITH THIS SYSTEM.
THEREFORE...KEPT HIGH LIKELY POPS ALONG AND AHEAD FRONT EXODUS.
LINGERING RAIN SHOWERS BEHIND THE SLOWLY PROGRESSING FRONT WARRANT
LOW CHANCES EARLY TUESDAY MAINLY EASTERN MOUNTAINS. A SECOND H5
VORT MAX IS EVIDENT IN TUESDAY NIGHT TO PROVIDE SOME FORCING FOR
ANY LOW LEVEL MOISTURE TRAPPED WEST OF THE MOUNTAINS FOR
CONTINUING LOW CHANCES THROUGH TUESDAY NIGHT. KEPT THUNDER OUT FOR
NOW BEHIND THE FRONT INTO TUESDAY NIGHT.
THE AFOREMENTIONED SCENARIO...TOGETHER WITH SKY COVER GUIDANCE
FROM THE GMOS...CMC HEM AND NAM12 INDICATE AREAS OF CLEARING
ACROSS PORTIONS OF SOUTHEAST OH...CENTRAL AND NORTHERN WV
SPREADING MONDAY NIGHT INTO TUESDAY. THIS WILL ALLOW WARMER LOW
TEMPERATURES ACROSS THE CENTRAL AND SOUTHERN MOUNTAINS...INCLUDING
SOME OF THE SOUTHERN COAL FIELDS THROUGH THE KY COUNTIES MONDAY
NIGHT...AND WARMER HIGH TEMPS TUES PER MORE PERIODS OF SUNSHINE
FARTHER NORTH AND WEST. THEREFORE...STARTED WITH THE BLEND OF MAV
AND MET NUMBERS TWEAKING UP OR DOWN DEPENDING ON CLOUD COVER.
SAME REASONING FOR HIGH TEMPS ON WEDNESDAY PER CLOUDS ASSOCIATED
WITH THE SECOND H5 WAVE AFFECTING THE SOUTHEAST QUADRANT OF OUR
CWA.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
QUITE A BIT OF UNCERTAINTY IN THE LONG TERM PERIOD AS MODELS HAVE
RUN TO RUN CONSISTENCY AND OVERALL AGREEMENT ISSUES. BUT GENERAL
CONSENSUS IS THAT A COLD FRONT IN ASSOCIATION WITH A LOW PRESSURE
SYSTEM MOVING EAST THROUGH CANADA WILL STALL OUT SOMEWHERE OVER THE
NORTHERN ZONES LATE THURSDAY/EARLY FRIDAY...WITH A LOW PRESSURE
SYSTEM OUT IN THE PLAINS MOVING NORTHEAST ALONG THE STALLED FRONTAL
BOUNDARY TOWARDS THE REGION FOR THE WEEKEND. THE LOW PRESSURE SYSTEM
AND ASSOCIATED COLD FRONT WILL PUSH EAST THROUGH THE REGION FRIDAY
THROUGH SATURDAY NIGHT...SPREADING SHOWERS AND THUNDERSTORMS INTO
THE REGION. THE LOW WILL MOVE OFF TO THE NORTHEAST ON SUNDAY...WITH
MUCH COOLER AIR FILTERING INTO THE REGION ON THE BACK SIDE OF THE
LOW. ANY LINGERING PRECIPITATION/MOISTURE IN THE NW UPSLOPE FLOW ON
THE BACK SIDE OF THE LOW COULD BE IN THE FORM OF A RAIN/SNOW MIX OR
EVEN SNOW OVER THE NORTHERN MOUNTAIN ZONES AS THE COLDER AIR TAKES
OVER ON THE BACK SIDE OF THE LOW.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. HOWEVER...BREEZY
TO GUSTY SW WINDS GENERALLY AROUND THE 20G30KT RANGE WILL CONTINUE
AS WELL THROUGH THE PERIOD AS A COLD FRONT APPROACHES FROM THE
WEST LATE TDY. LLJ 40 TO 50KTS ACROSS THE AREA WARRANT CARRYING
LLWS UNTIL 12Z WHEN MORE GUSTINESS SHOULD KICK IN WITH BETTER
MIXING AFTER SUNRISE.
A BKN LINE OF SHOWERS AND THUNDERSTORMS IS EXPECTED TO MOVE
ACROSS THE AREA ROUGHLY BETWEEN 18Z- 00Z...WEAKENING AS THEY CLOSE
IN ON MTNS. SOME OF THESE STORMS MAY BE STRONG TO SEVERE...WITH
STRONG WINDS. MVFR/LCL IFR IN CONVECTION BUT HAVE KEPT OUT OF TAFS
ATTM DUE TO UNCERTAINITY IN COVERAGE AND OUTSIDE OF TEMPO TIME
FRAME.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: WIND DIRECTION AND SPEED WILL TEND TO
FLUCTUATE. TIMING OF SHOWERS/THUNDERSTORMS MAY VARY.
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 MON 04/16/12
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 M 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 M H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z TUESDAY...
NO IFR EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...30
SHORT TERM...ARJ
LONG TERM...SL
AVIATION...30
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
206 AM EDT MON APR 16 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION ON MONDAY AS LOW PRESSURE
RACES FROM THE WESTERN GREAT LAKES INTO QUEBEC. HIGH PRESSURE WILL
THEN MOVE INTO THE AREA FOR TUESDAY INTO WEDNESDAY. THE NEXT AREA
OF LOW PRESSURE MAY MOVE ACROSS ONTARIO WEDNESDAY NIGHT WITH A
COLD FRONT PASSING THROUGH THE REGION ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATE...MADE ADJUSTMENT TO CLOUDS...POPS AND WX FOR MONDAY AS
WELL AS VARIOUS ADJUSTMENTS FOR THE OVERNIGHT. STILL EXPECT MAINLY
VARIABLE CLOUDS OVERNIGHT ALTHOUGH THERE SHOULD BE A TREND TOWARD
CLOUDS INCREASING AS SYSTEM APPROACHES FROM THE WEST. TOWARD
MORNING BROUGHT CHANCE POPS INTO THE FAR NORTHWEST. LINE LOOKS GOOD
AT PRESENT ALTHOUGH HRRR INDICATES THIS SHOULD WEAKEN AS IT
APPROACHES SO WANTED TO BEGIN WITH A CHANCE POP. EXPECT THROUGH
THE MORNING AND EARLY AFTERNOON COVERAGE WILL INCREASE SO WENT
WITH LIKELY FROM CENTRAL COUNTIES EAST FROM ABOUT NOON ON. WINDS
CONTINUE TO LOOK GOOD FOR TOMORROW SO ANTICIPATE THE NEED FOR A
HEADLINE. WILL ALLOW NEXT SHIFT TO PICK TIMING AND LOCATION BASED
ON NEW GUIDANCE.
PREVIOUS...GUSTY SOUTHERLY WINDS ARE EXPECTED THROUGH THE NIGHT
AS LOW PRESSURE OVER THE PLAINS SLOWLY MOVES TOWARD THE REGION.
OTHERWISE VARIABLE AMOUNTS OF HIGH LEVEL CLOUD COVER AND THE
STRONG WARM ADVECTION WILL LEAD TO A WARM NIGHT. MOST LOCATIONS
WILL BE NEAR TO SLIGHTLY ABOVE 60.
BESIDES THE FEW THUNDERSTORMS THAT ARE ATTEMPTING TO CLIP THE
ERIE AREA THROUGH 6 PM IT APPEARS THE THREAT OF RAIN IS VERY LOW.
HOWEVER AS THE COLD FRONT MOVES CLOSER TO THE REGION TOWARD
SUNRISE THERE MAY BE A FEW SCATTERED THUNDERSTORMS THAT DRIFT INTO
THE WESTERN COUNTY WARNING AREA.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
THE COLD FRONT WILL MOVE INTO NW OHIO EARLY MONDAY MORNING. THERE
IS MUCH UNCERTAINTY WITH THE AMOUNT OF CONVECTION THAT WILL BE
LOCATED NEAR THE FRONTAL BOUNDARY IN THE MORNING. MOISTURE LEVELS
MAY BE DIFFICULT TO KEEP ELEVATED ON MONDAY IF SOME DEEPER MIXING
CAN OCCUR AHEAD OF THE FRONT. THIS COULD HAVE A LIMITING AFFECT ON
THE THUNDERSTORM DEVELOPMENT AS THE FRONT MOVES TOWARD PA. STRONG
LOW LEVEL JET AHEAD OF THE FRONT WILL BE A FACTOR WITH THE
THUNDERSTORMS THAT CAN DEVELOP. SOME OF THIS WIND MAY BE BROUGHT
TO THE SURFACE WITH THE STRONGEST CONVECTION. HOWEVER THE MAIN
CONCERN WILL BE THE GUSTY WINDS AWAY FROM THE THUNDERSTORMS AS WE
ATTEMPT TO MIX THE STRONGER WINDS TO THE SURFACE WHERE HIGHS GET
INTO THE UPPER 70S. WINDS IN THE WAKE OF THE FRONT WILL ALSO
APPROACH ADVISORY LEVELS FOR A FEW HOURS. DID NOT HOIST A WIND
ADVISORY AT THIS TIME BUT THE POTENTIAL WILL CONTINUE TO BE
MENTIONED IN THE HWO.
HIGH PRESSURE WILL MOVE INTO THE REGION BY TUESDAY AND PERSIST
INTO WEDNESDAY. THIS WILL BRING DRIER AIR INTO THE REGION THAT
WILL ALLOW FOR LARGER DIURNAL RANGES. THE COLDEST NIGHT LOOKS LIKE
IT WILL BE TUESDAY NIGHT WITH MANY LOCATIONS ACROSS THE EASTERN
HALF OF THE AREA DIPPING TO AROUND 30 DEGREES. WARMER BY WEDNESDAY
AFTERNOON WITH HIGHS VERY CLOSE TO SEASONAL LEVELS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A WEAK COLD FRONT WILL MOVE THROUGH THE AREA THURSDAY AND HAS A
MINIMAL CHANCE OF PRODUCING SOME SHOWER ACTIVITY. MAINLY DUE TO THE
WEAK UPPER LEVEL AND MOISTURE SUPPORT. LOW PRESSURE WILL MOVE INTO
THE REGION FRIDAY EVENING AND BRING YET ANOTHER ROUND OF SHOWERS TO
THE REGION AS AN UPPER LEVEL TROUGH DIGS INTO THE EASTERN UNITED
STATES.
THE UPPER LEVEL TROUGH WILL LINGER INTO THE WEEKEND AND MOVE LITTLE
AS AMPLIFICATION OF THE RIDGE TAKES PLACE IN THE CENTRAL UNITED
STATES. THIS MEANS A TREND TOWARD COOLER TEMPERATURES DURING THE
WEEKEND. TEMPERATURES WILL LIKELY BE COOL ENOUGH TO SUPPORT THE MIX
OF RAIN AND WET SNOW SATURDAY NIGHT.
MODELS ARE SUGGESTING DRYING CONDITIONS RETURNING FOR SUNDAY INTO
SUNDAY NIGHT AS WEAK HIGH PRESSURE BUILDS EAST OVER THE REGION.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
GUSTY WINDS AND A THREAT OF THUNDER ARE THE WEATHER PROBLEMS FOR
TODAY. THE SHOWERS AND THUNDERSTORMS OVER INDIANA AND ILLINOIS ARE
DECREASING...HRRR MODEL CONCURS WITH THIS. A NARROW SQUALL LINE
DEVELOPS AHEAD OF THE FRONT LATE THIS MORNING AND MOVES EAST. THE
BEST CHANCE FOR THUNDER IS FROM CLE AND MFD EAST AS THE AIRMASS
WILL GET UNSTABLE ENOUGH.
THE PRESSURE GRADIENT WILL INCREASE DURING THE EARLY MORNING HOURS
AS THE WINDS ALOFT AT 925 MB AND 850 MB INCREASE IN EXCESS OF 50
KNOTS. AS THE WINDS AS THE SURFACE BECOME GUSTY THIS SHOULD
DECREASE THE THREAT OF LLWS. THE HRRR MODEL INCREASES THE GUSTS AT
THE SURFACE IN EXCESS OF 40 KNOTS BY NOON IN THE WARM ADVECTION.
IF WE CAN GET SOME SUNSHINE AND WE SHOULD THAT MAY BE OK. THE
WINDS WILL DECREASE AROUND SUNSET.
VFR FOR CLOUDS AND VISIBILITY EXCEPT IN SHOWERS AND THUNDERSTORMS.
HOWEVER...THE SREF IS TRYING TO INDICATE MVFR CEILINGS DEVELOPING
THIS MORNING AND ENDING THIS AFTERNOON. NOT REAL SURE OF
THIS...WILL NOT FORECAST IT ATTM.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE LATE MONDAY NIGHT INTO
TUESDAY AND THEN AGAIN WEDNESDAY NIGHT INTO FRIDAY.
&&
.MARINE...
WARM AIR ADVECTION TAKING PLACE OVER THE LAKE WILL LIKELY CAUSE
STRONGER WINDS AT THE SURFACE TO RIDE UP AND OVER THE COLD DOME.
THIS SHOULD KEEP WINDS BELOW SMALL CRAFT ADVISORY CRITERIA AT THE
LAKE SURFACE UNTIL COLD FRONT MOVES THROUGH LATE MONDAY AFTERNOON
AND EVENING.
WILL LIKELY NEED TO HOIST SMALL CRAFT ADVISORIES TOMORROW NIGHT AND
WILL POSSIBLY BE ABLE TO DROP IT BY TUESDAY AFTERNOON AS WINDS
DIMINISH CONSIDERABLY.
GENERALLY LIGHT FLOW EXPECTED INTO THURSDAY AND MARGINAL SMALL CRAFT
WAVES WILL LIKELY DEVELOP THURSDAY NIGHT BUT DIMINISH ON FRIDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MULLEN
NEAR TERM...TK/MULLEN
SHORT TERM...MULLEN
LONG TERM...LOMBARDY
AVIATION...KIELTYKA
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
209 AM EDT MON APR 16 2012
.SYNOPSIS...
WELL ABOVE NORMAL TEMPERATURES WILL OCCUR ON MONDAY IN ADVANCE OF A
COLD FRONT WHICH WILL TRAVERSE THE REGION TOMORROW EVENING. HIGH
PRESSURE WILL BUILD IN FOR THE REST OF THE WEEK. A DEEPENING
TROUGH WILL LIKELY FORM OVER THE EASTERN CONUS BY NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
CIRRUS CLOUDS AND A SW BREEZE WILL KEEP TEMPS VERY MILD EARLY THIS
MORNING WITH MOST LOCATIONS BOTTOMING OUT IN THE 50S. SATL TRENDS
AND RUC 400-200MB RH FIELDS SUGGEST CIRRUS WILL LIFT NORTH OF THE
AREA BY ARND 12Z.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/...
ANOMALOUSLY WARM AIR MASS AND A CLEAR SKY FOR THE FIRST PART OF
THE DAY WILL LEAD TO SOME SPOTS GETTING TO WITHIN 4-5F OF THEIR
DAILY RECORD MAXES. THE GEFS MEAN 850 TEMPS ARE CLOSE TO 15C.
SUCH 8H TEMPS SHOULD EASILY TRANSLATE TO HIGH TEMPS FROM THE U70S
ALLEGHENY MTNS...TO THE M80S OVER THE SUSQ VALLEY. DEWPOINTS
TOMORROW WILL BE IN THE MID TO UPPER 50S...THOUGH IT SHOULDNT FEEL
ADVERSELY MOIST GIVEN THE STRONG PRESSURE GRADIENT MOVING THROUGH
THE REGION. BUFKIT SOUNDING DATA SUPPORTS GUSTS BTWN 25-35KTS
ACROSS THE NW DURING THE LATE MORNING AND THROUGH THE AFTERNOON AS
WINDS MIX TO THE SFC. DECENT SPEED SHEAR AHEAD OF THE FRONT AS
THE NOSE OF A LL JET WORKS THRU THE GREAT LAKES MAY COUPLE WITH
THE WARM MOIST TO ALLOW FOR MARGINALLY UNSTABLE CONDITIONS TO FORM
PM TSRA IN WRN PA AND MOVE IT TO THE EAST ALONG WITH THE FRONT AS
IT TRAVERSES THE COMMONWEALTH. DOWNSLOPE EFFECTS AND LOSS OF A
GOOD MOISTURE SOURCE SHOULD WEAKEN AND DISSIPATE THE SCT
CONVECTION IN THE EVENING. MODEL DATA AND SPC OUTLOOKS POINT TO A
MARGINAL SVR WX THREAT ACROSS THE N/WRN COUNTIES EARLY IN THE
EVENING BEFORE THE CONVECTION WANES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
WENT WITH A CHC OF SHOWERS AND THUNDERSTORMS ACROSS THE MOUNTAINS
MONDAY EVENING. AGREE WITH SPC...PHI...ETC...NOT MUCH WILL MAKE
IT EAST OF THE MOUNTAINS...AS DYNAMICS ARE TO THE WEST...LACK
OF SFC CONVERGENCE...AND HEATING IS LOST. HOWEVER..REMAINS OF
CONVECTION TO THE WEST WILL LIKELY MAKE IT INTO THE MOUNTAINS...
GIVEN TIMING.
TUE LOOKS LIKE A NICE DAY. SOMEWHAT BREEZY. IT WILL BE DRY OUT...
AS DEWPOINT DEPRESSIONS WILL BE IN THE 30 TO 40 DEGREE RANGE LATE
IN THE DAY. WENT WARMER THAN GUIDANCE.
FOR TUE NIGHT...EXPECT NOT A LOT OF CLDS OR WIND. WITH DRY AIR
IN PLACE...WENT WITH LOWER TEMPS.
WED LOOKS LIKE ANOTHER DECENT DAY. WITH WITH SLIGHTLY HIGHER
TEMPS.
THERE COULD BE A SHOWER ACROSS THE FAR NW LATE WED NIGHT.
FOR THU...THERE WILL BE A CHC OF A SHOWER...MAINLY NORTH AND
WEST OF THE LOWER SUSQUEHANNA VALLEY.
NOT LOOKING AT MUCH GOING ON THU NIGHT.
THE BIG STORY WILL BE FRIDAY INTO NEXT SUNDAY. WHILE SOME
OF THE MODELS MAY BE OVERDONE WITH THE SYSTEM...THE PATTERN
SUPPORTS A FAIRLY DEEP LOW WITH BREEZY AND COLD TEMPS...AND
PRECIPITATION. THERE WILL LIKELY BE A TIGHT WEST...EAST
TEMP GRADIENT FROM NW TO SE. RAIN COULD BE ON THE HEAVY SIDE.
I HAVE SOME SNOW IN FOR NEXT SUNDAY MORNING...AS SOME COULD
MIX WITH THE RAIN ON THE WEST SIDE OF THE LOW...GIVEN COLD
ADVECTION...AND SIGNIFICANT MOISTURE. STILL SOME CHC SUNDAY
NIGHT...BUT AIRMASS WILL BE MODERATING...AND MOISTURE STARTING
TO LIFT OUT...THUS I LEFT SNOW OUT FOR SUNDAY NIGHT.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS PREVAIL ACROSS THE REGION. HAVE INCLUDED A PERIOD
OF MVFR VSBYS OVER KIPT...KMDT AND KLNS DUE TO LOWERED T/TD
SPREAD OF ONLY 3 TO 5 DEGREES AND LIGHT SURFACE WINDS. OVER
CENTRAL AND WESTERN AIRFIELDS...T/TD SPREADS REMAIN 8-10 DEGREES
SO LOWER CONFIDENCE OF FOG. HOWEVER...WILL WATCH FOR POSSIBLE FOG
FORMATION AS THE NIGHT CONTINUES IN THESE LOCATIONS AS WELL.
VFR CONDITIONS FOR MONDAY. APPROACHING FRONT WILL BRING A CHANCE
OF SHOWERS AND THUNDERSTORMS TO NW REGIONS...ESPECIALLY KBFD. HAVE
NOT INCLUDED IN TAF AT THIS TIME BASED ON UNCERTAINTY IN COVERAGE.
STRENGTHENING SOUTHWESTERLY LOW LEVEL JET WILL HAS INTRODUCED
LLWS INTO MOST CENTRAL PA AIRFIELDS THROUGH ABOUT NOONTIME.
EXCEPTION IS IN FAR SOUTHEAST WHERE LOW LEVEL JET WINDS EXPECTED
TO BE LESS VIGOROUS. LLWS CONDITIONS WILL ABATE AS WINDS MIX DOWN
AND SURFACE WINDS BECOME GUSTY DURING THE LATE MORNING/EARLY
AFTERNOON.
OUTLOOK...
TUE-FRI...VFR. MAY SEE SOME SHRA THU PM/FRI AS NEXT FRONT
APPROACHES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/CERU
NEAR TERM...FITZGERALD
SHORT TERM...DANGELO/CERU
LONG TERM...MARTIN
AVIATION...JUNG/DEVOIR
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
222 AM CDT MON APR 16 2012
.UPDATE...
EARLY AM UPDATE REFLECTS OUTFLOW TRIGGERED CONVECTION OVER OUR
SOUTHEAST COUNTIES. DPROG/DT ANALYSIS OF MODELS SHOWS AN
INCREASING TREND TOWARD CONVECTION BACKING WESTWARD INTO OUR
CENTRAL COUNTIES...AND SATELLITE IMAGERY REFLECTS THIS TREND WITH
GROWING MID-LEVEL CLOUDS OVER OUR WESTERN COUNTIES. PER SPENES
ISSUANCE LAST HOUR...THE FAR SOUTHEAST COUNTIES MAY SEE SPOTTY
RAINFALL TOTALS IN EXCESS OF 2 INCHES FROM SLOW MOVING ACTIVITY
AND VERY COLD CLOUD TOPS. ROUTINE MORNING PACKAGE IS ALMOST
COMPLETED WITHIN THIS EARLY MORNING UPDATE...AND CONTINUES TO SHOW
ANOTHER ROUND OF RAINS POSSIBLE FOR FRIDAY. WILL CONTINUE TO
MONITOR THE CONVECTIVE TRENDS AND ADDITIONAL MODEL DATA TO MAKE
MAINLY 1ST AND 2ND PERIOD CHANGES AS NEEDED BEFORE SENDING OUT THE
FULL MORNING FORECAST PACKAGE.
&&
.PREV DISCUSSION... /ISSUED 1156 PM CDT SUN APR 15 2012/
AVIATION...
WEAK DISTURBANCES WILL PUSH ACROSS TONIGHT BEHIND A COLD FRONT WHICH
WILL STALL ALONG THE COASTAL REGIONS. VFR CLOUDINESS WILL CONTINUE OVER
THE I-35 CORRIDOR TAF SITES DUE TO CLOUD DEBRIS BLOWOFF FROM CONVECTION
ALONG THE COASTAL PLAINS. MOSTLY VFR CLEAR KDRT SITE TONIGHT.
ANOTHER DISTURBANCE APPROACHING FROM THE WEST LATE MONDAY AND
MONDAY NIGHT WILL BRING INCREASING MID AND UPPER LEVEL CLOUDINESS
TO THE AREA. I-35 CORRIDOR TERMINALS VARIABLE CLOUDS AOA 6 THSD.
LIGHT NORTH WINDS BECOMING LIGHT NORTHEAST MONDAY. KDRT TERMINAL
VFR CLEAR. KDRT WINDS LIGHT NORTH TONIGHT AND EARLY MONDAY
BECOMING LIGHT EASTERLY BY MIDDAY.
PREV DISCUSSION... /ISSUED 1139 PM CDT SUN APR 15 2012/
UPDATE...
A BIT SURPRISED BY THE RESURGENCE IN CONVECTION ALONG THE FRONT
OVER THE COASTAL PLAINS...SO WE HAD TO PUT POPS FOR SHOWERS AND
THUNDERSTORMS BACK INTO THE FORECAST FOR THE SOUTHEASTERN
COUNTIES. IT STILL SEEMS MOST OF THE ACTIVITY WILL REMAIN OUTSIDE
OF OUR AREA.
PREV DISCUSSION... /ISSUED 1007 PM CDT SUN APR 15 2012/
UPDATE...
JUST SENT A QUICK GRID AND TEXT UPDATE TO REMOVE POPS IN THE FAR
SOUTHEAST COUNTIES AND RETREND TEMPS...DEW POINTS...AND WINDS
OVERNIGHT. NO MAJOR CHANGES TO THE OVERALL FORECAST.
PREV DISCUSSION... /ISSUED 327 PM CDT SUN APR 15 2012/
DISCUSSION...
THE SFC FRONT IS SLOWLY WORKING ITS WAY INTO THE COASTAL
PLAINS...WITH SCATTERED CONVECTION CONTINUING ALONG THE FRONTAL
BOUNDARY. THE FRONT IS EXPECTED TO STALL ALONG THE COAST LATER
TONIGHT...WITH GOOD CONSENSUS AMONG THE NAM/GFS OF POST-FRONTAL
PRECIPITATION CONTINUING ACROSS OUR SOUTHERN COUNTIES.
HOWEVER...THE 18Z RUC AND 12Z HI-RES BOTH INDICATE THE PRECIP AXIS
WILL SHIFT COMPLETELY SOUTH OF OUR CWA THIS EVENING. HAVE SOMEWHAT
SPLIT THE DIFFERENCE AND KEPT TOKEN POPS ACROSS OUR SOUTHEASTERN
TIER OF COUNTIES FOR THIS EVENING.
AS THE FRONT STALLS ALONG THE COAST OVERNIGHT...THE MID-UPPER
LEVEL TROUGH AXIS WILL REMAIN NORTHWEST OF OUR AREA. THEREFORE
SOME POST-FRONTAL SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP
ACROSS THE SOUTHEASTERN HALF OF THE REGION TOMORROW AND INTO
TOMORROW NIGHT. RAIN CHANCES WILL CLEAR THE AREA ON TUESDAY AS THE
UPPER TROUGH AXIS SLIDES TO THE EAST OF THE REGION AND DRIER NW
FLOW ALOFT SETTLES INTO THE AREA. MOSTLY DRY AND SEASONABLE
CONDITIONS WILL PREVAIL THROUGH THE MIDDLE OF THE WEEK WITH
ONSHORE FLOW RETURNING LATE TUESDAY/EARLY WEDS. THE INCREASING LOW
LEVEL MOISTURE WILL RESULT IN A SLOW WARMING TREND THROUGH THE END
OF THE WEEK.
MID/LONG-RANGE MODELS CONTINUE TO HAVE FAIR CONSENSUS ON AN UPPER
TROUGH/COLD FRONT FOR OUR AREA LATE IN THE WEEK. CURRENT THINKING
IS THAT THE BEST TIME-FRAME FOR RAIN WOULD BE FRI AFTERNOON/NIGHT.
HOWEVER...THIS COULD EASILY SHIFT TO A FRI NIGHT/SAT MORNING OR
LATER SCENARIO GIVEN WE`RE TALKING ABOUT 126-PLUS HRS FROM NOW.
FIRE WEATHER...
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
ACROSS THE SOUTHERN EDWARDS PLATEAU AND RIO GRANDE PLAINS THROUGH
THIS EVENING IN THE WAKE OF THE COLD FRONT. LOW RELATIVE HUMIDITIES
AND GUSTY NORTHWEST WINDS NEAR 15 MPH WILL CONTINUE THROUGH THE
REMAINDER OF THE AFTERNOON WITH WINDS DECREASING TO 10 TO 15 MPH
AFTER SUNSET. RH VALUES WILL BE SLOWER TO RECOVER. ELEVATED FIRE
WEATHER CONDITIONS ARE EXPECTED ACROSS WESTERN AREAS ON MONDAY
AFTERNOON MAINLY DUE TO LOW HUMIDITIES AS WINDS WILL BE AT OR
BELOW 10 MPH.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 79 57 82 60 83 / 20 30 - - -
AUSTIN BERGSTROM INTL AIRPORT 79 55 81 55 82 / 20 30 - - -
NEW BRAUNFELS MUNI AIRPORT 79 57 81 58 81 / 30 30 - - -
BURNET MUNI AIRPORT 79 51 80 56 81 / 10 10 0 - -
DEL RIO INTL AIRPORT 84 58 85 62 86 / 0 - 0 - -
GEORGETOWN MUNI AIRPORT 78 52 80 55 81 / 20 20 - - -
HONDO MUNI AIRPORT 80 53 82 57 82 / 10 10 0 - -
SAN MARCOS MUNI AIRPORT 78 56 80 57 81 / 30 30 - - -
LA GRANGE - FAYETTE REGIONAL 78 60 80 59 81 / 40 30 10 - -
SAN ANTONIO INTL AIRPORT 79 57 82 59 82 / 20 20 - - -
STINSON MUNI AIRPORT 79 58 82 59 83 / 30 20 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...01
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1156 PM CDT SUN APR 15 2012
.AVIATION...
WEAK DISTURBANCES WILL PUSH ACROSS TONIGHT BEHIND A COLD FRONT WHICH
WILL STALL ALONG THE COASTAL REGIONS. VFR CLOUDINESS WILL CONTINUE OVER
THE I-35 CORRIDOR TAF SITES DUE TO CLOUD DEBRIS BLOWOFF FROM CONVECTION
ALONG THE COASTAL PLAINS. MOSTLY VFR CLEAR KDRT SITE TONIGHT.
ANOTHER DISTURBANCE APPROACHING FROM THE WEST LATE MONDAY AND
MONDAY NIGHT WILL BRING INCREASING MID AND UPPER LEVEL CLOUDINESS
TO THE AREA. I-35 CORRIDOR TERMINALS VARIABLE CLOUDS AOA 6 THSD.
LIGHT NORTH WINDS BECOMING LIGHT NORTHEAST MONDAY. KDRT TERMINAL
VFR CLEAR. KDRT WINDS LIGHT NORTH TONIGHT AND EARLY MONDAY
BECOMING LIGHT EASTERLY BY MIDDAY.
&&
.PREV DISCUSSION... /ISSUED 1139 PM CDT SUN APR 15 2012/
UPDATE...
A BIT SURPRISED BY THE RESURGENCE IN CONVECTION ALONG THE FRONT
OVER THE COASTAL PLAINS...SO WE HAD TO PUT POPS FOR SHOWERS AND
THUNDERSTORMS BACK INTO THE FORECAST FOR THE SOUTHEASTERN
COUNTIES. IT STILL SEEMS MOST OF THE ACTIVITY WILL REMAIN OUTSIDE
OF OUR AREA.
PREV DISCUSSION... /ISSUED 1007 PM CDT SUN APR 15 2012/
UPDATE...
JUST SENT A QUICK GRID AND TEXT UPDATE TO REMOVE POPS IN THE FAR
SOUTHEAST COUNTIES AND RETREND TEMPS...DEW POINTS...AND WINDS
OVERNIGHT. NO MAJOR CHANGES TO THE OVERALL FORECAST.
PREV DISCUSSION... /ISSUED 327 PM CDT SUN APR 15 2012/
DISCUSSION...
THE SFC FRONT IS SLOWLY WORKING ITS WAY INTO THE COASTAL
PLAINS...WITH SCATTERED CONVECTION CONTINUING ALONG THE FRONTAL
BOUNDARY. THE FRONT IS EXPECTED TO STALL ALONG THE COAST LATER
TONIGHT...WITH GOOD CONSENSUS AMONG THE NAM/GFS OF POST-FRONTAL
PRECIPITATION CONTINUING ACROSS OUR SOUTHERN COUNTIES.
HOWEVER...THE 18Z RUC AND 12Z HI-RES BOTH INDICATE THE PRECIP AXIS
WILL SHIFT COMPLETELY SOUTH OF OUR CWA THIS EVENING. HAVE SOMEWHAT
SPLIT THE DIFFERENCE AND KEPT TOKEN POPS ACROSS OUR SOUTHEASTERN
TIER OF COUNTIES FOR THIS EVENING.
AS THE FRONT STALLS ALONG THE COAST OVERNIGHT...THE MID-UPPER
LEVEL TROUGH AXIS WILL REMAIN NORTHWEST OF OUR AREA. THEREFORE
SOME POST-FRONTAL SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP
ACROSS THE SOUTHEASTERN HALF OF THE REGION TOMORROW AND INTO
TOMORROW NIGHT. RAIN CHANCES WILL CLEAR THE AREA ON TUESDAY AS THE
UPPER TROUGH AXIS SLIDES TO THE EAST OF THE REGION AND DRIER NW
FLOW ALOFT SETTLES INTO THE AREA. MOSTLY DRY AND SEASONABLE
CONDITIONS WILL PREVAIL THROUGH THE MIDDLE OF THE WEEK WITH
ONSHORE FLOW RETURNING LATE TUESDAY/EARLY WEDS. THE INCREASING LOW
LEVEL MOISTURE WILL RESULT IN A SLOW WARMING TREND THROUGH THE END
OF THE WEEK.
MID/LONG-RANGE MODELS CONTINUE TO HAVE FAIR CONSENSUS ON AN UPPER
TROUGH/COLD FRONT FOR OUR AREA LATE IN THE WEEK. CURRENT THINKING
IS THAT THE BEST TIME-FRAME FOR RAIN WOULD BE FRI AFTERNOON/NIGHT.
HOWEVER...THIS COULD EASILY SHIFT TO A FRI NIGHT/SAT MORNING OR
LATER SCENARIO GIVEN WE`RE TALKING ABOUT 126-PLUS HRS FROM NOW.
FIRE WEATHER...
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
ACROSS THE SOUTHERN EDWARDS PLATEAU AND RIO GRANDE PLAINS THROUGH
THIS EVENING IN THE WAKE OF THE COLD FRONT. LOW RELATIVE HUMIDITIES
AND GUSTY NORTHWEST WINDS NEAR 15 MPH WILL CONTINUE THROUGH THE
REMAINDER OF THE AFTERNOON WITH WINDS DECREASING TO 10 TO 15 MPH
AFTER SUNSET. RH VALUES WILL BE SLOWER TO RECOVER. ELEVATED FIRE
WEATHER CONDITIONS ARE EXPECTED ACROSS WESTERN AREAS ON MONDAY
AFTERNOON MAINLY DUE TO LOW HUMIDITIES AS WINDS WILL BE AT OR
BELOW 10 MPH.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 75 54 81 57 82 / 100 - 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 80 52 81 55 82 / 100 - 20 10 -
NEW BRAUNFELS MUNI AIRPORT 82 52 80 56 81 / 80 - 20 10 -
BURNET MUNI AIRPORT 73 49 78 52 80 / 60 - - - 0
DEL RIO INTL AIRPORT 82 51 84 57 86 / 10 - - - 0
GEORGETOWN MUNI AIRPORT 73 49 79 51 81 / 100 - 10 10 -
HONDO MUNI AIRPORT 81 50 81 55 84 / 50 - 20 10 0
SAN MARCOS MUNI AIRPORT 81 53 80 57 81 / 80 - 20 10 -
LA GRANGE - FAYETTE REGIONAL 81 60 80 60 80 / 50 - 40 30 10
SAN ANTONIO INTL AIRPORT 79 54 81 58 82 / 70 - 20 10 -
STINSON MUNI AIRPORT 82 55 81 60 83 / 70 - 20 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...02
SYNOPTIC/GRIDS...26
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1139 PM CDT SUN APR 15 2012
.UPDATE...
A BIT SURPRISED BY THE RESURGENCE IN CONVECTION ALONG THE FRONT
OVER THE COASTAL PLAINS...SO WE HAD TO PUT POPS FOR SHOWERS AND
THUNDERSTORMS BACK INTO THE FORECAST FOR THE SOUTHEASTERN
COUNTIES. IT STILL SEEMS MOST OF THE ACTIVITY WILL REMAIN OUTSIDE
OF OUR AREA.
&&
.PREV DISCUSSION... /ISSUED 1007 PM CDT SUN APR 15 2012/
UPDATE...
JUST SENT A QUICK GRID AND TEXT UPDATE TO REMOVE POPS IN THE FAR
SOUTHEAST COUNTIES AND RETREND TEMPS...DEW POINTS...AND WINDS
OVERNIGHT. NO MAJOR CHANGES TO THE OVERALL FORECAST.
PREV DISCUSSION... /ISSUED 327 PM CDT SUN APR 15 2012/
DISCUSSION...
THE SFC FRONT IS SLOWLY WORKING ITS WAY INTO THE COASTAL
PLAINS...WITH SCATTERED CONVECTION CONTINUING ALONG THE FRONTAL
BOUNDARY. THE FRONT IS EXPECTED TO STALL ALONG THE COAST LATER
TONIGHT...WITH GOOD CONSENSUS AMONG THE NAM/GFS OF POST-FRONTAL
PRECIPITATION CONTINUING ACROSS OUR SOUTHERN COUNTIES.
HOWEVER...THE 18Z RUC AND 12Z HI-RES BOTH INDICATE THE PRECIP AXIS
WILL SHIFT COMPLETELY SOUTH OF OUR CWA THIS EVENING. HAVE SOMEWHAT
SPLIT THE DIFFERENCE AND KEPT TOKEN POPS ACROSS OUR SOUTHEASTERN
TIER OF COUNTIES FOR THIS EVENING.
AS THE FRONT STALLS ALONG THE COAST OVERNIGHT...THE MID-UPPER
LEVEL TROUGH AXIS WILL REMAIN NORTHWEST OF OUR AREA. THEREFORE
SOME POST-FRONTAL SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP
ACROSS THE SOUTHEASTERN HALF OF THE REGION TOMORROW AND INTO
TOMORROW NIGHT. RAIN CHANCES WILL CLEAR THE AREA ON TUESDAY AS THE
UPPER TROUGH AXIS SLIDES TO THE EAST OF THE REGION AND DRIER NW
FLOW ALOFT SETTLES INTO THE AREA. MOSTLY DRY AND SEASONABLE
CONDITIONS WILL PREVAIL THROUGH THE MIDDLE OF THE WEEK WITH
ONSHORE FLOW RETURNING LATE TUESDAY/EARLY WEDS. THE INCREASING LOW
LEVEL MOISTURE WILL RESULT IN A SLOW WARMING TREND THROUGH THE END
OF THE WEEK.
MID/LONG-RANGE MODELS CONTINUE TO HAVE FAIR CONSENSUS ON AN UPPER
TROUGH/COLD FRONT FOR OUR AREA LATE IN THE WEEK. CURRENT THINKING
IS THAT THE BEST TIME-FRAME FOR RAIN WOULD BE FRI AFTERNOON/NIGHT.
HOWEVER...THIS COULD EASILY SHIFT TO A FRI NIGHT/SAT MORNING OR
LATER SCENARIO GIVEN WE`RE TALKING ABOUT 126-PLUS HRS FROM NOW.
FIRE WEATHER...
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
ACROSS THE SOUTHERN EDWARDS PLATEAU AND RIO GRANDE PLAINS THROUGH
THIS EVENING IN THE WAKE OF THE COLD FRONT. LOW RELATIVE HUMIDITIES
AND GUSTY NORTHWEST WINDS NEAR 15 MPH WILL CONTINUE THROUGH THE
REMAINDER OF THE AFTERNOON WITH WINDS DECREASING TO 10 TO 15 MPH
AFTER SUNSET. RH VALUES WILL BE SLOWER TO RECOVER. ELEVATED FIRE
WEATHER CONDITIONS ARE EXPECTED ACROSS WESTERN AREAS ON MONDAY
AFTERNOON MAINLY DUE TO LOW HUMIDITIES AS WINDS WILL BE AT OR
BELOW 10 MPH.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 54 81 57 82 60 / - 20 10 - -
AUSTIN BERGSTROM INTL AIRPORT 52 81 55 82 56 / - 20 10 - -
NEW BRAUNFELS MUNI AIRPORT 52 80 56 81 57 / 20 20 10 - -
BURNET MUNI AIRPORT 49 78 52 80 55 / - - - 0 -
DEL RIO INTL AIRPORT 51 84 57 86 63 / - - - 0 -
GEORGETOWN MUNI AIRPORT 49 79 51 81 56 / - 10 10 - -
HONDO MUNI AIRPORT 50 81 55 84 58 / - 20 10 0 -
SAN MARCOS MUNI AIRPORT 53 80 57 81 58 / - 20 10 - -
LA GRANGE - FAYETTE REGIONAL 60 80 60 80 60 / 20 40 30 10 -
SAN ANTONIO INTL AIRPORT 54 81 58 82 60 / - 20 10 - -
STINSON MUNI AIRPORT 55 81 60 83 60 / - 20 10 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...02
SYNOPTIC/GRIDS...26
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
645 PM CDT TUE APR 17 2012
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
312 PM CDT TUE APR 17 2012
MAIN FORECAST CONCERN IS ON THE MULTITUDE OF PRECIPITATION CHANCES
THROUGHOUT THE SHORT TERM...ESPECIALLY THURSDAY NIGHT AND FRIDAY.
P-TYPE ALSO A CONCERN FOR THURSDAY NIGHT AND FRIDAY.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED NEARLY ZONAL FLOW ACROSS MUCH OF THE COUNTRY WITH PERHAPS
SOME WEAK RIDGING OVER IDAHO AND MINNESOTA. IN-BETWEEN THESE TWO
WEAK RIDGES...A FAIRLY POTENT SHORTWAVE TROUGH IS NOTED OVER CENTRAL
MONTANA. DOWNSTREAM OF THIS SHORTWAVE...MID CLOUDS HAVE BEEN
SPREADING EAST ACROSS THE DAKOTAS AND MINNESOTA. NO PRECIPITATION AS
OF YET...DUE TO DRY AIR SEEN ON THE 12Z BIS SOUNDING BELOW 600MB.
HOWEVER...SOUTHERLY 925MB WINDS OF 10 TO 20 KT IS SLOWLY BRINGING
MORE LOW LEVEL MOISTURE NORTHWARD. DEWPOINTS HAVE CLIMBED INTO THE
MID 40S OVER MUCH OF EASTERN SOUTH DAKOTA. FARTHER SOUTHEAST...
ISENTROPIC LIFT ON THE 295K SURFACE HAS RESULTED IN SCATTERED MID-
CLOUD DEVELOPMENT OVER IOWA AND SOUTHERN MINNESOTA. MOSTLY SUNNY
SKIES OVER THE FORECAST AREA COMBINED WITH 850MB TEMPS SLOWLY
RISING...WHICH WERE 0 TO -7C PER 12Z RAOB ANALYSIS...HAS HELPED
PUSH TEMPERATURES INTO THE 50S TO LOW 60S.
TONIGHT AND WEDNESDAY...FOCUS IS ON THE POTENT SHORTWAVE TROUGH.
MODELS REMAIN REMARKABLY CONSISTENT ON THIS TROUGH TRACKING
EAST...REACHING WESTERN UPPER MICHIGAN BY 18Z WEDNESDAY. AS THE
TROUGH APPROACHES TONIGHT...A STRONG SURGE OF 850MB MOISTURE
TRANSPORT COMES UP AHEAD OF IT. PRECIPITABLE WATER CLIMBS TO 0.75 TO
1 INCH BY 12Z WEDNESDAY...A JUMP FROM 0.3 TO 0.6 INCHES NOW. THIS
SURGE OF MOISTURE COMBINED WITH DPVA/HEIGHT FALLS ASSOCIATED WITH
THE TROUGH (30-70 METERS IN 12 HOURS) WILL LIKELY LEAD TO THE
DEVELOPMENT OF A NARROW WARM CONVEYOR BELT OF SHOWERS. MUCAPE VALUES
ARE LESS THAN 300 J/KG...WHICH IS A THIN CAPE TOO ON SOUNDINGS...SO
ANTICIPATE AT MOST JUST SOME SCATTERED EMBEDDED THUNDERSTORMS. GIVEN
VERY PERSISTENT SIGNAL ON PRECIPITATION TONIGHT INTO WEDNESDAY
MORNING...HAVE RAISED PRECIPITATION CHANCES TO 100...WITH THE PEAK
TIME OF PRECIPITATION EXPECTED BETWEEN 09-15Z WEDNESDAY. DURING THE
LATE MORNING AND AFTERNOON...A DRY SLOT IS PROGGED TO COME IN BEHIND
THE SHORTWAVE TROUGH...WHICH WHEN COMBINED WITH THE SURFACE FRONT
PUSHING EAST SHOULD END PRECIPITATION OVER THE NORTHWEST HALF OF THE
AREA. OVER THE SOUTHEAST HALF...THE COLD FRONT ENDS UP SLOWING DOWN
AS THE TROUGH PULLS AWAY. COULD SEE ADDITIONAL DIURNAL DEVELOPMENT
OF SHOWERS AND STORMS ALONG THIS FRONT AS CAPE JUMPS TO AROUND 500
J/KG. THEREFORE...CHANCES OF PRECIPITATION REMAIN IN THE SOUTHEAST
HALF IN THE AFTERNOON...MAINLY IN THE 40-50 RANGE. WITH INCREASING
WARM ADVECTION TONIGHT...LOWS LIKELY TO OCCUR IN THE EVENING WITH A
SLOW RISE THEREAFTER. NEEDLESS TO SAY...A MUCH WARMER NIGHT
TONIGHT. ON WEDNESDAY...A SURGE OF 6-8C 850MB TEMPS COMING UP
WITH THE TROUGH COMBINED WITH SUN SHOULD ALLOW FOR HIGHS IN THE
60S TO POSSIBLY LOW 70S.
WEDNESDAY NIGHT AND THURSDAY...FOLLOWED THE PREVIOUS FORECAST IN
MAINTAINING A 20 PERCENT CHANCE DOWN IN THE FAR SOUTHEAST SECTION OF
THE FORECAST AREA WEDNESDAY EVENING...TO ACCOUNT FOR THE SLOW MOVING
COLD FRONT AND ANY LINGERING SHOWERS/STORMS ON IT. A SURFACE RIDGE
OF HIGH PRESSURE BUILDS IN ELSEWHERE BEHIND THE FRONT...LEADING TO
DRY CONDITIONS FOR THE EVENING. ATTENTION THEN FOCUSES ON A
SHORTWAVE TROUGH JUST OFF THE PACIFIC NORTHWEST COAST. ON WEDNESDAY
NIGHT...THIS TROUGH ALONG WITH A FEW OTHERS COMING OFF THE PACIFIC
HELP DEVELOP A BROAD TROUGH ALONG THE LEE SIDE OF THE ROCKIES. IN
RESPONSE...MOISTURE TRANSPORT...ISENTROPIC LIFT AND LOW TO MID LEVEL
FRONTOGENESIS INCREASES DOWNSTREAM...LEADING TO PRECIPITATION
DEVELOPMENT. PRIOR TO 12Z THURSDAY...MUCH OF THIS PRECIPITATION
LOOKS TO BE CONFINED TO THE DAKOTAS INTO IOWA. DID MAINTAIN THE
20-30 PERCENT CHANCES MAINLY WEST OF THE RIVER LATE WEDNESDAY NIGHT
IN CASE THE PRECIPITATION SPREADS IN QUICKER. MUCH BETTER SHOT FOR
PRECIPITATION EXISTS ON THURSDAY AS THE LOW TO MID LEVEL
FRONTOGENESIS TIGHTENS THROUGH THE DAY OVER THE AREA. IN
ADDITION...THERE ARE INDICATIONS THAT IN THE AFTERNOON AN UPPER
LEVEL JET STREAK DEVELOPING OVER NORTHERN WISCONSIN. THIS WOULD BE
VERY FAVORABLE FOR PRECIPITATION. LASTLY...LOW LEVEL MOISTURE
TRANSPORT NORTH OF A DEVELOPING WARM FRONT NEAR US-20 SHOULD BRING
SOME INSTABILITY INTO THE FRONTOGENESIS ZONE. THEREFORE...HAVE
MAINTAINED THE THUNDER CHANCES. TEMPERATURES DEFINITELY COOLER
DURING THIS TIME PERIOD...ESPECIALLY NORTH OF I-90 WHERE A NORTHEAST
FLOW WILL HELP TO FEED COOL AIR IN. WILL HAVE TO WATCH TEMPERATURES
WHEN THE PRECIPITATION STARTS...AS THEY MAY FALL DUE TO THE FEED OF
30S DEWPOINTS INTO THE AREA. HOWEVER...DID NOT INCLUDE ANY
NON-DIURNAL TREND GIVEN THE 17.12Z ECMWF/CANADIAN/UKMET WHICH IS
FARTHER NORTH WITH THE WARMER AIR.
THURSDAY NIGHT AND FRIDAY...FOCUS CONTINUES ON THE STRENGTHENING
FRONTOGENESIS ZONE OVER THE AREA FROM THURSDAY AFTERNOON. ALL MODELS
ARE WELL AGREED UPON THAT THE TROUGHING OVER THE ROCKIES WILL DIG
DOWN INTO THE CENTRAL PLAINS THURSDAY NIGHT. HOWEVER...THE 17.12Z
GFS/NAM ARE MORE PROGRESSIVE WITH EXITING THE FRONTOGENESIS ZONE TO
THE EAST AND SOUTHEAST THAN THE 17.12Z ECMWF/UKMET/CANADIAN. AM
CONCERNED THE GFS/NAM ARE TOO PROGRESSIVE. IF SO...THE NON-NCEP
MODEL GROUP WOULD YIELD A LOT MORE PRECIPITATION THURSDAY NIGHT...
ESPECIALLY FROM NORTHEAST IOWA TO GREEN BAY. THEY SHOW ANYWHERE FROM
1 TO 2 INCHES OF RAINFALL. THE NORTH EDGE OF SOME OF THIS...SAY IN
CENTRAL AND NORTHERN WISCONSIN...IS LIKELY TO MIX WITH OR CHANGE
OVER TO SNOW AS CONTINUED DRY/COOL AIR FEED AND DYNAMIC COOLING HELP
LOWER THE THERMODYNAMIC PROFILE TEMPERATURES. TOO EARLY TO SAY HOW
MUCH SNOW SAY COULD ACCUMULATE IN TAYLOR COUNTY...WHICH IS MOST
LIKELY TO SEE SNOW...BUT SOMETHING TO KEEP AN EYE ON. IN ANY
EVENT...HAVE LEANED THE FORECAST FOR THIS PERIOD TOWARDS THE
ECMWF/UKMET/CANADIAN...WHICH RESULTS IN AN INCREASE IN PRECIPITATION
CHANCES AND QPF FOR BOTH THURSDAY NIGHT AND FRIDAY. FURTHER
INCREASES MAY BE NECESSARY...ESPECIALLY IF THE GFS/NAM COME AROUND.
FOR TEMPERATURES...TOOK A BLEND OF GUIDANCE FOR NOW UNTIL MODELS CAN
SETTLE DOWN.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
312 PM CDT TUE APR 17 2012
17.12Z ECMWF/GFS AND GFS ENSEMBLES ARE IN GOOD AGREEMENT SUGGESTING
THAT THE TROUGH DIGGING DOWN THROUGH THE CENTRAL PLAINS THURSDAY
NIGHT AND FRIDAY ENDS UP CLOSING OFF NEAR THE GULF COAST FOR
SATURDAY. THIS IS AN IMPORTANT CHANGE AS NOW THE TROUGHING OVER THE
FORECAST AREA FOR THE WEEKEND IS NOT NEARLY AS DEEP. COMPARE THIS TO
THE 17.12Z CANADIAN WHICH DEVELOPS A FULL-BLOWN EASTERN TROUGH THAT
LOOKS VERY COLD. THIS MODEL SCENARIO APPEARS TO BE AN OUTLIER AND
WAS DISCOUNTED. FOLLOWING THE MAIN MODEL GROUP...MUCH OF FRIDAY
NIGHT THROUGH MONDAY SHOULD BE DRY WITH THE AREA DOMINATED BY
SURFACE HIGH PRESSURE IN THE WAKE OF FRIDAYS FRONTOGENESIS ZONE.
MAY HAVE TO DEAL WITH A LITTLE LIGHT PRECIP SATURDAY NIGHT...
ASSOCIATED WITH A SHORTWAVE COMING DOWN THROUGH THE NORTHWEST
FLOW. ALSO...WITH WITH THE RIDGE BUILDING FRIDAY NIGHT...LOCATIONS
ALONG AND NORTH OF I-94 MAY HAVE TO CONTEND WITH ANOTHER FREEZE.
RIDGING THAT DEVELOPS DURING THE WEEKEND OVER THE WESTERN U.S.
IS FORECAST TO PUSH EASTWARD MONDAY INTO TUESDAY...DUE TO A POTENT
SHORTWAVE TROUGH DROPPING INTO THE PACIFIC NORTHWEST. THE RIDGING
WILL HELP TO PUSH WARMER AIR INTO THE AREA...WITH TEMPERATURES
LIKELY CLIMBING ABOVE NORMAL. CONVECTION COULD OCCUR LATE TUESDAY
AS A WARM FRONT / LOW PRESSURE SYSTEM OVER THE NORTHERN PLAINS
MOVES INTO OUR REGION.
&&
.AVIATION...
645 PM CDT TUE APR 17 2012
THE SFC PRESSURE GRADIENT WILL BE TIGHTENING ACROSS THE REGION AS A
COLD FRONT APPROACHES FROM THE NORTHERN PLAINS. BUFKIT SOUNDINGS
DON/T SHOW MUCH DECOUPLING THIS EVENING...SO LOOKING FOR INCREASING
WINDS OVERNIGHT...AND WOULD NOT BE SURPRISED IF THERE WAS SOME
GUSTINESS FROM TIME TO TIME. LOOKING FOR A SHIFT FROM SOUTH TO WEST
WITH THE FRONTAL PASSAGE...NEAR 18Z AT KRST AND 21Z AT KLSE. IT
SHOULD ALSO BE NOTED THAT THE LOW LEVEL WINDS WILL ALSO BE
INCREASING TONIGHT...WITH BUFKIT SOUNDINGS POINTING TO 50 KTS AT 190
BY 06Z AT KRST.
CLOUDS WILL BE ON THE INCREASE...WITH A GRADUAL LOWERING IN THE CIGS
AS THE FRONT NEARS. COULD SEE A FEW HOURS OF MVFR JUST AHEAD OF THE
FRONT.
WHILE THE BEST UPPER LEVEL FORCING WILL STAY NORTH...LOW LEVEL
MOISTURE TRANSPORT AHEAD OF THE FRONT WILL HELP SPARK -SHRA AROUND
THE FRONT. INSTABILITY IS LIMITED...AND WILL NOT ADD A TS MENTION TO
THE TAFS AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
312 PM CDT TUE APR 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM... AJ
LONG TERM.... AJ
AVIATION..... RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
319 PM CDT MON APR 16 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
319 PM CDT MON APR 16 2012
MAIN FORECAST CONCERNS ARE ON FREEZE TONIGHT AND PRECIPITATION
CHANCES FOR TUESDAY NIGHT...WEDNESDAY AND AGAIN THURSDAY.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S....TROUGHING FROM ONTARIO INTO
TEXAS AND RIDGING ALONG THE EAST COAST OF THE U.S.. WITHIN THE
TROUGHING...A POTENT SHORTWAVE TROUGH WAS OVER UPPER MICHIGAN WHICH
HAS BEEN RESPONSIBLE FOR THE WINDY CONDITIONS LATELY...WHILE ANOTHER
SHORTWAVE WAS NEAR SIOUX FALLS SOUTH DAKOTA. THIS LATTER SHORTWAVE
WAS NOT DOING MUCH PRECIPITATION WISE...BUT THERE IS A DEFINITE BAND
OF LOW TO MID LEVEL CLOUDS COVERING MUCH OF THE DAKOTAS INTO
SOUTHWEST MINNESOTA. 12Z BIS SOUNDING WAS NEARLY SATURATED FROM 925
TO 700MB...SO THE SHORTWAVE DOES APPEAR TO BE SPREADING AT LEAST
CLOUDS EASTWARD. AHEAD OF THESE CLOUDS AND IN THE WAKE OF THE POTENT
TROUGH...THERE IS SOME CLEARING DROPPING DOWN THROUGH NORTHERN AND
CENTRAL MINNESOTA. WINDS ARE SLOWLY DIMINISHING ACROSS THE AREA DUE
TO A WEAKENING PRESSURE GRADIENT. SURFACE PRESSURE ANALYSIS SHOWED A
997MB LOW WAS LOCATED OVER THE EASTERN UPPER PENINSULA WHILE A RIDGE
OF HIGH PRESSURE WAS OVER THE DAKOTAS. THE WINDY NORTHWEST WINDS
HAVE DROPPED 850MB TEMPS DOWN TO -4 TO -8C OVER THE FORECAST AREA
PER RUC ANALYSIS...AND -10 TO -12C OVER NORTHERN WISCONSIN. THIS
COLD AIR LED TO SOME STRAIGHT SNOW OR RAIN/SNOW MIX OVER NORTHERN
PORTIONS OF THE FORECAST AREA THIS MORNING. 850MB TEMPS NOT MUCH
WARMER OVER THE DAKOTAS EITHER...-2 TO -6C...CONFIRMED TOO BY 12Z
RAOBS.
TONIGHT AND TUESDAY...UPPER LEVEL FLOW IS PROGGED TO BECOME MORE
ZONAL DURING THIS PERIOD AS A SHORTWAVE OFF THE PACIFIC NORTHWEST
COAST PLOWS INLAND ACROSS THE NORTHERN ROCKIES. FOR OUR AREA...WE
WILL HAVE A FEW SHORTWAVES MOVE THROUGH...THE FIRST OF WHICH IS THE
ONE NEAR SIOUX FALLS CROSSING THIS EVENING...THEN ANOTHER MUCH
WEAKER ONE SEEN ON WATER VAPOR OVER EASTERN MONTANA WHICH COMES
THROUGH TUESDAY MORNING. AGAIN...NOT ANTICIPATING ANY PRECIPITATION
WITH EITHER SHORTWAVE BECAUSE OF A LACK OF BOTH DYNAMICAL AND
ISENTROPIC LIFT. THEY WILL...HOWEVER...BRING AN INCREASE OF LOW TO
MID LEVEL STRATUS. SO AFTER WHAT COULD BE A BRIEF PERIOD OF CLEARING
THIS EVENING...MAINLY NORTH OF I-94 ASSOCIATED WITH THAT CLEARING
DROPPING DOWN THROUGH CENTRAL MINNESOTA...EXPECTING SKIES TO AT
LEAST TURN MOSTLY CLOUDY. LIKELY THE STRATUS SHOULD CLEAR OUT IN THE
WAKE OF THE SECOND SHORTWAVE...BUT THIS APPEARS BRIEF AS WELL.
LOOKING AT TUESDAY AFTERNOON...290-300 K ISENTROPIC LIFT REALLY
INCREASES DOWNSTREAM OF THAT SHORTWAVE COMING INTO THE ROCKIES...
RESULTING IN MORE MID LEVEL STRATUS. LIFT DOES NOT LOOK STRONG
ENOUGH TO PRODUCE PRECIPITATION...THOUGH. ALL OF THESE CLOUD
TRANSITIONS MAKE THE TEMPERATURE FORECAST DIFFICULT. IF IT WERE
CLEAR TONIGHT...THE SURFACE RIDGE MOVING IN AND HAVING 850MB TEMPS
IN THE 0 TO -6C RANGE IN PLACE WOULD BE VERY FAVORABLE FOR
TEMPERATURES TO PLUMMET WELL BELOW FREEZING. WITH THE CLOUDS MOVING
THROUGH TONIGHT...GENERALLY FOLLOWED CLOSE TO A BLEND OF THE 16.12Z
NAM12/16.09Z SREF MEAN. THE LOWS PROMPT THE NEED FOR A FREEZE
WARNING ALONG/NORTH OF I-94. LOWS MAY DIP TO FREEZING
ELSEWHERE...SUCH AS LA CROSSE...BUT CONFIDENCE IS NOT HIGH ENOUGH TO
ISSUE FREEZE WARNING DUE TO THE CLOUDS. FOR TUESDAY...RETURN FLOW
DOES HELP TO BOOST 850MB TEMPS UP TO 2-6C BY 00Z WEDNESDAY...BUT
TEMPERATURES WILL BE HELD BACK SOMEWHAT DUE TO THE CLOUDS. FOLLOWED
GENERALLY A BLEND OF GUIDANCE FOR HIGHS.
TUESDAY NIGHT AND WEDNESDAY...FOCUS IS ON THAT SHORTWAVE COMING OUT
OF THE ROCKIES. VERY GOOD MODEL AGREEMENT EXISTS THAT AS THE
SHORTWAVE CROSSES THE DAKOTAS AND LIFTS INTO FAR NORTHERN WISCONSIN
WEDNESDAY MORNING...IT WILL DEEPEN. IN RESPONSE TO THIS DEEPENING...
A STRONG SURGE OF SOUTHWEST 850MB MOISTURE TRANSPORT/ISENTROPIC LIFT
ON THE 290-295K SURFACE COMES ACROSS THE AREA TUESDAY EVENING.
SHOULD SEE SOME SHOWERS FALL IN THE EVENING. THERE IS SOME WEAK
CAPE...LESS THAN 200 J/KG...ENOUGH TO WARRANT A THUNDER MENTION.
AFTER MIDNIGHT INTO WEDNESDAY MORNING...THE COMBINATION OF HEIGHT
FALLS ALOFT WITH THE APPROACHING SHORTWAVE AND A PERSISTENT FLOW OF
850MB MOISTURE TRANSPORT SHOULD LEAD TO THE DEVELOPMENT OF A WARM
CONVEYOR BELT OF SHOWERS AND EMBEDDED THUNDERSTORMS. GIVEN DECENT
COVERAGE OF PRECIPITATION DEVELOPMENT...CAPE SHOULD STAY LIMITED AT
LESS THAN 500 J/KG...LIMITING ANY CHANCE FOR SEVERE WEATHER. THIS
WARM CONVEYOR BELT WILL TRACK WEST TO EAST ACROSS THE AREA THROUGH
WEDNESDAY MORNING. GIVEN GOOD MODEL CONSENSUS FOR PRECIPITATION...
HAVE RAISED PRECIPITATION CHANCES UP TO 80 PERCENT. A DRY SLOT THEN
ENTERS THE PICTURE FOR LATE WEDNESDAY MORNING INTO THE AFTERNOON...
PUNCHING IN FROM THE WEST IN THE WAKE OF THE SHORTWAVE TROUGH
LIFTING OFF TO THE NORTHEAST. THIS DRY SLOT SHOULD END PRECIPITATION
AND LIKELY RESULT IN A DECREASE IN CLOUDS. MUCH WARMER CONDITIONS
ANTICIPATED TUESDAY NIGHT WITH LOWS IN THE EVENING...THEN CLIMBING
SLIGHTLY AFTER MIDNIGHT WITH THE MOISTURE TRANSPORT SURGE. WARMER
850MB TEMPS OF 4-8C ON WEDNESDAY...PLUS SUN...WILL ALLOW FOR HIGHS
IN THE 60S TO EVEN 70.
WEDNESDAY NIGHT AND THURSDAY...THIS PERIOD FOCUS IS ON A COLLECTIONS
OF SHORTWAVES PROGGED TO MOVE INTO THE NORTHERN ROCKIES LATE
WEDNESDAY. HEIGHT FALLS DOWNSTREAM OF THESE SHORTWAVES HELP DEVELOP
A SURFACE LOW IN SOUTHEAST COLORADO. GOOD MODEL CONSENSUS EXISTS
THAT THE COLLECTION OF SHORTWAVES WILL DIG DOWN INTO THE CENTRAL
PLAINS WEDNESDAY NIGHT...LEADING TO A SHIELD OF DPVA AND DEFORMATION
FORCED PRECIPITATION DOWNSTREAM. AT THIS TIME IT APPEARS ANY
PRECIPITATION SHOULD HOLD OFF UNTIL THURSDAY. THERE ARE SOME ISSUES
THAT REMAIN FOR THURSDAY...THOUGH. ALTHOUGH GREAT MODEL AGREEMENT
EXISTS BETWEEN THE 16.12Z GFS/NAM/ECMWF/CANADIAN THAT MUCH OF THE
AREA SEES THAT DPVA AND DEFORMATION PRECIPITATION...THE
ECMWF/CANADIAN REMAIN FARTHER NORTH WITH THE ASSOCIATED SURFACE
SYSTEM. IF THESE HOLD TRUE...THUNDER CHANCES WOULD BE REQUIRED FOR
AT LEAST LOCATIONS SOUTH OF I-90. FOR NOW HAVE KEPT THUNDER OUT
GIVEN THAT IT RECENTLY WAS AND THE PERSISTENCE FOR MORE SOUTHERN
SOLUTIONS...BUT THIS WILL NEED TO BE WATCHED. CERTAINLY POTENTIAL
HERE FOR SOME DECENT QPE VALUES TOO...WITH CURRENT FORECAST QPF
ANYWHERE FROM 0.25 TO 0.75 INCHES.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
319 PM CDT MON APR 16 2012
GOOD AGREEMENT REMAINS AMONGST 16.12Z GFS/ECMWF/CANADIAN AND GFS
ENSEMBLES ON SHOWING MAJOR AMPLIFICATION WITH THE UPPER FLOW DURING
THE LONG TERM PERIOD. RIDGING IN THE WESTERN U.S. DEVELOPS THURSDAY
NIGHT THROUGH SATURDAY WHILE A POTENT SHORTWAVE RIDES DOWN THE
RIDGE...FORMING A DEEP TROUGH OVER THE SOUTHEASTERN U.S. BY SATURDAY
NIGHT. BY MONDAY...A BLOCKED UP PATTERN IS FORECAST WITH STRONG
RIDGING OVER THE WESTERN U.S. AND A WIDE/DEEP CUT-OFF UPPER LOW OVER
THE EASTERN U.S.. THIS MEANS A COOL PATTERN FOR THE FORECAST
AREA...THOUGH OVERALL RELATIVELY DRY. REALLY ONLY PRECIPITATION TO
SPEAK OF IS THURSDAY NIGHT...ASSOCIATED WITH DEFORMATION AND DPVA
INDUCED RAIN FROM THURSDAY SLOWLY EXITING. ENOUGH COLD AIR DOES WRAP
DOWN INTO THE AREA FOR A MIX OR CHANGE OVER TO SNOW...THOUGH IT IS
CONCEIVABLE THE PRECIPITATION ENDS BEFORE THE COLDER AIR ARRIVES.
ALSO HAVE A SLIGHT CHANCE OF RAIN SHOWERS IN FOR SATURDAY NIGHT
WHERE THERE ARE SUGGESTIONS OF A SHORTWAVE DROPPING DOWN INTO THE
EASTERN TROUGH. ONLY KEPT AT 20 PERCENT GIVEN VERY FEW MODELS HAVE
THIS PRECIPITATION. IN FACT...LATER FORECASTS MAY BE ABLE TO PULL
THIS IF ALL MODELS TREND TOWARD THE ECMWF/GFS. OTHERWISE...
TEMPERATURES ARE THE STORY WHICH AGAIN LOOK TO HOLD BELOW NORMAL. IN
ADDITION...COULD BE DEALING WITH FREEZE WARNINGS FOR FRIDAY NIGHT
AND POSSIBLY SATURDAY NIGHT AS WELL...IF THE PRECIPITATION DOES NOT
MATERIALIZE. BEST CHANCE FOR FREEZE IS AGAIN ALONG AND NORTH OF
I-94. PERHAPS TOWARDS MONDAY WE WILL BE ABLE TO CLIMB BACK TO NEAR
OR ABOVE NORMAL WITH HINTS OF THE UPPER RIDGE TRYING TO BUILD
TOWARDS THE AREA.
&&
.AVIATION...THIS AFTERNOON THROUGH TUESDAY
1225 PM CDT MON APR 16 2012
THE STRONG LOW PRESSURE SYSTEM CONTINUED TO MOVE QUICKLY AWAY FROM
THE AREA AT MID-DAY. THE STRONG WEST/NORTHWEST WINDS WERE BEGINNING
TO DECREASE AS THE GRADIENT RELAXED AND STRONGEST PRESSURE RISES
BEHIND THE LOW MOVED INTO NORTHERN WI. THE WINDS WILL CONTINUE TO
DECREASE THRU THE DAY THEN BECOME QUITE LIGHT THIS EVENING/OVERNIGHT
AS A RIDGE OF HIGH PRESSURE QUICKLY MOVES INTO MN/WI. THE HIGH WILL
ALREADY MOVE EAST OF THE AREA ON TUE WITH LIGHTER SOUTH WINDS
RETURNING TO THE TAF SITES. THE VFR/MVFR STRATUS ARE MORE
PROBLEMATIC. THE CLOUD DECK REMAINS MVFR WELL WEST OF THE AREA OVER
CENTRAL/NORTHERN MN AT MID-DAY...WITH THE FLOW TO ROTATE THESE
CLOUDS/MOISTURE SOUTHEAST ACROSS THE AREA INTO THIS EVENING.
DRYING/MIXING WITH THE MAIN LOW MOVING WELL EAST OF THE AREA SHOULD
ALLOW THE CIGS TO GRADUALLY RISE INTO THE 3K-4K FT LATER THIS
AFTERNOON/EVENING. CLOUD DECK SHOULD THEN SCATTER OUT THIS EVENING
WITH THE SFC-850MB RIDGE BUILDING IN...BUT ANOTHER MID-LEVEL
SHORTWAVE WILL SPIN ACROSS THE AREA DURING THE EVENING AND MAY
PROVIDE ENOUGH LIFT FOR THE CLOUD DECKS TO REMAIN BKN THRU THE
EVENING AND PERHAPS OVERNIGHT. SUBSIDENCE/FURTHER DRYING BEHIND THE
SHORTWAVE EXPECTED BRING A VFR DAY TO THE AREA ON TUE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
319 PM CDT MON APR 16 2012
WI...FREEZE WARNING FROM 1 AM TO 8 AM CDT TUESDAY FOR WIZ017-029-034-
042>044.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
319 AM EDT WED APR 18 2012
.SYNOPSIS...
CONDITIONS ARE EXPECTED TO BE DRY INTO FRIDAY...EXCEPT FOR THE
CHANCE OF LIGHT RAIN IN THE RIDGES TODAY. A WEEKEND COLD FRONT
SHOULD BRING THE NEXT CHANCE FOR WIDESPREAD RAIN.
&&
.NEAR TERM /THROUGH TONIGHT/...
ALL MODELS ARE IN GOOD AGREEMENT SHOWING THE PASSAGE OF AN UPPER
LEVEL SHORTWAVE MOVING ACROSS THE MID-ATLANTIC STATES TODAY AND
TONIGHT. SYNOPTIC/HI-RES MODELS ALSO SHOW SIMILAR DEPICTIONS OF
TIGHT PRECIPITATION GRADIENT FALLING JUST EAST OF THE FORECAST AREA.
HOWEVER...COMPARING MODEL FORECASTS AT 06Z TO RADAR SHOWS THAT ALL
MODELS EXCEPT FOR THE HRRR HAVE NOT TRENDED PRECIP FAR ENOUGH TO THE
NORTH AND WEST. THEREFORE...HAVE MOVED MORE IN THE DIRECTION OF THE
21Z SREF AND 03Z HRRR...BRINGING POPS FARTHER INTO
FAYETTE...MARION...AND MONONGALIA COUNTIES. LATER FORECASTS MAY NEED
TO BRING RAIN FARTHER TO THE NORTH AND WEST. CLOUD SHIELD WILL
EXTEND EVEN FARTHER TO THE NORTH AND WEST...WITH ALL LOCATIONS
EXPECTING PARTLY CLOUDY SKIES IN THE MORNING AND INCREASING SUN
OUTSIDE OF THE RIDGES IN THE AFTERNOON. RAIN COULD POTENTIALLY HOLD
ON INTO THE EVENING HOURS IN THE RIDGES...BUT WILL DRY OUT FOR THE
OVERNIGHT HOURS. TEMPERATURES SHOULD BE FAIRLY CLOSE TO YESTERDAYS
VALUES.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
LOW PRESSURE OVER QUEBEC THURSDAY MORNING WILL MOVE TO THE
EAST...WITH A TRAILING COLD FRONT ACROSS THE GREAT LAKES. COLD FRONT
SHOULD REMAIN ACROSS THE EASTERN GREAT LAKES ON THURSDAY...KEEPING
DRY WEATHER LOCALLY. FRONT WILL MAKE VERY SLOW PROGRESS
FRIDAY...WITH SHOWERS FINALLY DRIFTING INLAND. 21Z SREF IS THE
OUTLIER FOR MOVING THE FRONT THROUGH FRIDAY NIGHT...AND WILL
CONTINUE TO GO WITH SLOWER GFS/ECMWF SOLUTIONS. RAIN SHOULD FINALLY
MOVE IN FOR SATURDAY. WITH SOUTHWESTERLY FLOW...TEMPERATURES WILL BE
ON THE INCREASE THURSDAY AND FRIDAY...RISING TO 10 AND THEN 15
DEGREES ABOVE NORMAL. FRONTAL TIMING WILL BE THE KEY TO HIGH
TEMPERATURES ON SATURDAY...AND FOR NOW HAVE DROPPED TEMPERATURES
BACK TO NEAR NORMAL LEVELS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
PRECIPITATION WILL TAPER TO SCATTERED COVERAGE AS COLD FRONT MOVES
EAST SATURDAY NIGHT. MODELS SHOW A CLOSED UPPER LOW FORMING AT
THE BOTTOM OF A SHARP TROUGH AND RIDING EAST ALONG THE GULF COAST
SATURDAY AND SUNDAY. LATEST MODEL RUNS STILL DIFFER ON THE TRACK
OF A SURFACE LOW MOVING ALONG THE EASTERN SEABOARD AND THE WESTERN
EXTENT OF PRECIPITATION MONDAY AND TUESDAY. FORECAST POPS ARE
CLOSE TO HPC NUMBERS WITH HIGH END CHANCE POPS SUNDAY TAPERING TO
AROUND 30 PERCENT ALONG THE RIDGES AND SLIGHT CHANCE FURTHER WEST
BY MONDAY MORNING.
TEMPERATURES ARE FORECAST TO COOL TO BETWEEN 5 AND 10 DEGREES BELOW
NORMAL BY EARLY NEXT WEEK.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
EXPECT VFR TO CONTINUE ACROSS THE UPPER OHIO VALLEY THROUGH
TONIGHT, WITH LITTLE MORE THAN BANDS OF ALTOCUMULUS. SURFACE WINDS
WILL BE FROM THE NORTHEAST AND EAST AT 4-8 KTS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
EXPECT VFR THURSDAY AND FRIDAY. RESTRICTIONS WILL BECOME LIKELY
FRIDAY NIGHT INTO SUNDAY DUE TO SHOWERS ASSOCIATED WITH THE SLOW
PASSAGE OF AN EASTBOUND LOW PRESSURE SYSTEM.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GLASGOW MT
403 AM MDT WED APR 18 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH FRIDAY...
THE SHORT TERM FORECAST IS A HARD ONE TODAY FOR NORTHEAST
MONTANA... MANY VARIABLES PLAYING INTO THE FORECAST EQUATION FOR
THE NEXT 48 HOURS.
FOR THE FIRST 12 HOUR TOOK THE HRRR FOR THE POPS/QPF FORECAST. IT
HAS PREFORMED VERY WELL THIS SPRING SEASON. PLUS THE GFS/NAM AGAIN
ARE BRINGING HIGH QPF VALUES TO NORTHEAST MONTANA. THE MODELS HAVE
A POOR TRACK RECORD IN THE PAST MONTH WITH FORECASTING QPF OVER
NORTHEAST MONTANA WITH A TREMENDOUS WET BIAS. MODEL SOUNDINGS SHOW
AT THE GGW POINT ...ALONG WITH BUFR SOUNDINGS... A SLOW MOISTENING
OF THE DRY LOW LEVELS THROUGH THE AFTERNOON HOURS. SPLIT THE
WEATHER GRIDS FOR THE FIRST 12 HOURS INTO 3 HOUR BLOCKS. DID THIS
TO SHOW THE STUBBORNLY SLOW PROGRESS OF MEASURABLE PRECIPITATION
ACROSS THE REGION. DO EXPECT LOTS OF VIRGA AND GUSTY WINDS THIS
AFTERNOON AS THE ATMOSPHERE MOISTENS UP. DECIDED TO FLY THE LAKE
WIND ADVISORY WITH THE MARGINAL 15 TO 25 MPH WINDS DUE TO THE GUST
FACTOR THAT COULD SURPRISE IN EXPERIENCED BOATERS EARLY IN THE SEASON.
TONIGHT WENT WITH HIGH POP LOW QPF/LITTLE OR CHANCE OF WETTING
RAIN SOLUTION. CONFIDENCE IS MODERATE... MODELS ALL ARE GOING FOR
A WETTING RAIN ACROSS MOST OF NORTHEAST MONTANA. HOWEVER THE MODEL
PERFORMANCE ON RAINFALL HAS BEEN POOR AND OVER FORECASTING
RAINFALL.
ON THURSDAY AS THE WINDS SWITCH TO THE WEST ACROSS
THE AREA CLOUD BASES WILL RISE AND AGAIN THE BOUNDARY LAYER SHOULD
DRY OUT KEEPING MEASURABLE PRECIPITATION VALUES LOW. THE ONE
ISSUE THAT COULD INCREASE POPS THURSDAY AFTERNOON IS VERY STEEP
LAPSE RATES WHICH COULD SPARK A THUNDERSTORM AND CREATE SMALL
AREAS OF HIGHER RAINFALL.
THURSDAY NIGHT THE DAKOTA LOW WILL CONTINUE TO DRIFT EAST KEEPING
MOST AREAS DRY. ON FRIDAY A LOW MOVES OFF THE ALBERTA ROCKIES AND
SLIDES ACROSS SASKATCHEWAN INTO NORTH DAKOTA IN THE NORTHWEST FLOW
AHEAD OF THE BUILDING RIDGE. THIS MIGHT BRING ANOTHER VERY SLIGHT
CHANCE OF WETTING RAINS WITH STRONGER SHOWERS ACROSS THE NORTHERN
TIER OF ZONES. OTHERWISE MORE DUST SETTLING SHOWERS WITH LITTLE
RAIN RELIEF EXPECTED. PROTON
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
THE LAST IN A SERIES OF SEVERAL SHORTWAVE DISTURBANCES FROM THE W
MOVES OUT OF THE AREA FRI NIGHT. THEN A BUILDING UPPER RIDGE FROM
THE S OVER THE WEEKEND BRINGS SUNNY AND WARMER WEATHER. THE RIDGE
BECOMES QUITE STRONG WITH 850 MB TEMPS TO AS HIGH AS 18-24C
MONDAY. THICKNESSES VALUES REACH 570 DM. THIS SHOULD DRIVE NE MT
HIGHS INTO THE UPPER 70S TO MID 80S...WHICH WILL APPROACH RECORD
HIGHS FOR THE DATE AT SOME LOCATIONS.
MODELS AGREE WITH A MOSTLY DRY...BUT FAIRLY STRONG COLD FRONT FROM THE
WNW MOVING ACROSS THE AREA TUE...WHICH WILL START A COOLING TREND.
THE ASSOCIATED UPPER TROUGH LAGS BEHIND...AND MODELS HAVE VARIED
ON TIMING...INTENSITY...AND MOVEMENT WITH THIS. ECMWF HAS BEEN
TOO QUICK TO BREAK DOWN THE RIDGE. MEANWHILE CMC GEM DEFLECTS BOTH
COLD FRONT AND TROUGH TO OUR N AND KEEPS THE RIDGE OVER OUR AREA...WHICH
DOES APPEAR POSSIBLE. GFS ENSEMBLES INDICATE THAT ANY OF THESE AND
OTHER SOLUTIONS ARE POSSIBLE TOO...SO LOW CONFIDENCE AT THE END OF
THE PERIOD. PREFER THE 00Z OPERATIONAL GFS THOUGH WHICH IS MORE
OF A MIDDLE GROUND SOLUTION...AND DOES BRING AT LEAST A SLIGHT
CHANCE OF SHOWERS BY WED. SIMONSEN
&&
.AVIATION...
VFR...BUT WITH INCREASING CLOUDS 10 K FT AGL AND ABOVE TODAY.
W-SE WINDS INCREASE TO 10 TO 20KT. LATE THIS AFTERNOON AND
TONIGHT...CEILINGS LOWER TO 4K FT AGL WITH SCATTERED
SHOWERS...AND AN ISOLATED THUNDERSTORM OR TWO POSSIBLE AS WELL.
ALTHOUGH NOT AFFECTING ANY NE MT TAF SITE...THERE IS A CHANCE OF
SNOW MIXED WITH THE RAIN LATE TONIGHT ACROSS OUR MOST NORTHERN
LOCATIONS...INCLUDING DANIELS...SHERIDAN..AND NORTHERN VALLEY
COUNTIES. THESE AREAS COULD DROP TO 3 TO 5 MILE VISIBILITY AT
TIMES...WITH BROKEN CEILINGS 1-3K FT AGL. SIMONSEN
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 9 PM MDT THIS
EVENING FOR FORT PECK LAKE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
302 AM CDT WED APR 18 2012
.DISCUSSION...
MAIN FORECAST CONCERN WILL BE POPS IN THE NEAR TERM AS QUIET AND
WARMER WEATHER IS EXPECTED FOR THE WEEKEND INTO EARLY NEXT WEEK.
LATEST REGIONAL RADAR IMAGERY SHOWED BAND OF SHOWERS AND
THUNDERSTORMS PROGRESSING SOUTHEAST ACROSS THE NORTHERN PORTION
OF THE CWA. ACTIVITY IS ALONG A WEAK COLD FRONT OUT AHEAD OF A MID
LEVEL SHORTWAVE MOVING EWD THRU THE CENTRAL DAKOTAS. LATEST
SEVERAL RUNS OF THE HRRR HAVE HAD A GOOD HANDLE ON THIS LINE AND
EXPECT THE ACTIVITY TO EXIT THE SOUTHEASTERN FORECAST AREA AROUND
14Z.
WEAK FRONT WASHES OUT OVER THE AREA AND STRONG SOUTHERLY FLOW
RETURNS TONIGHT. ANOTHER WEAK SHORTWAVE WL MOVE THRU THE DAKOTAS
TONIGHT PUSHING A STRONGER COLD FRONT INTO THE FORECAST AREA
OVERNIGHT. THIS WILL BRING ANOTHER GOOD CHANCE FOR SCATTERED
SHOWERS AND THUNDERSTORMS OVERNIGHT AND INTO THURSDAY. THE FRONT
IS SLOW TO MOVE THRU AND LINGERS MUCH OF THE DAY THURSDAY UNTIL
STRONGER UPPER LEVEL SUPPORT ARRIVES THURSDAY NIGHT. CONTINUED
SMALL POPS IN OUR SOUTH LATE THURSDAY NIGHT INTO FRIDAY MORNING.
WARMING TREND ANTICIPATED FOR THE WEEKEND AND EARLY NEXT WEEK AS
AMPLIFIED UPPER RIDGE BUILDS OVER THE WESTERN CONUS. HIGHS IN THE
LOW 80S FORECAST BY TUESDAY.
KERN
&&
.AVIATION...06Z TAFS FOR KOFK...KOMA AND KLNK.
VFR CIGS WITH MID CLDS FLO080-012 WILL PUSH ACROSS THE TAF SITES
THROUGH 12Z. SOME LOWER VFR CIGS MAY DEVELOP AS SHOWERS AND A FEW
ISOLATED THUNDERSTORMS ACCOMPANY A COLD FRONT. THERE IS
INSTABILITY...AND MAY NEED TO ADD THUNDER AT THE SITE IF IT
BECOMES MORE PREVALENT ON THE SOUTHERN END OF THE LINE. BRISK
SOUTH TO SOUTHWEST WINDS AT 10 TO 20 KT WITH SOME HIGHER GUSTS
WILL GRADUALLY DECREASE BEHIND THE FRONT AFTER IT MOVES INTO
EASTERN NEBRASKA. INCLUDED LOW LEVEL WIND SHEAR THIS MORNING WITH
PROFILERS AT 45 TO 50KT IN ERN NEB. THE FRONT IS SLOW TO MOVE
THROUGH AND WILL AFFECT THE WIND SHIFTS...WITH THE WINDS BECOMING
NORTHWEST...THEN NORTHEAST...THEN SOUTHEAST THROUGH 06Z.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
228 AM EDT WED APR 18 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL APPROACH FROM THE WEST LATE TODAY AND
TONIGHT BRINGING UNSETTLED WEATHER TO THE REGION. A STRONG STORM
SYSTEM IS EXPECTED TO BRING THE THREAT OF HEAVY RAIN OVER THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 915 PM...
MOISTURE AND POTENTIAL ENERGY QUITE LIMITED WITH SCATTERED
CONVECTION LOW TOPPED AT THIS TIME. MOST MODELS CONTINUE TO
ATTEMPT TO DEVELOP PRECIPITATION TONIGHT ALONG THE BOUNDARY NEAR
SOUTH CAROLINA. HOWEVER THE RUC MODEL CONTINUES TO SHOW LIMITED
MOISTURE THROUGHOUT THE AIR COLUMN AND ONLY WEAK LOW LEVEL
CONVERGENCE IN THAT AREA. TO THE WEST CONVERGENCE LOCKED IN OVER
THE FOOTHILLS WITH MODELS OCCASIONALLY PRODUCING CONVERGENCE AND
LIFT IN THE WESTERN PIEDMONT. BEST CONVERGENCE WILL CONTINUE TO BE
OVER THE MOUNTAINS AND THE WESTERN FOOTHILLS TONIGHT. ISOLATED
RAINFALL AMOUNTS COULD BE IN EXCESS OF ONE INCH IN THE WEST... BUT
BASIN AVERAGES WILL GENERALLY BE QUITE LOW... AT A FEW HUNDREDTHS
OUTSIDE THE HEAVIEST SHOWERS. WILL LEAVE LOW LIKELY POPS IN THE
FAR WEST WITH CHANCE TO SLIGHT CHANCE POPS AS ONE MOVES EAST.
NORTHEAST FLOW WITH LOW LEVEL THICKNESSES AT SUNRISE WEDNESDAY
FALLING ABOUT 25 METERS FROM THIS MORNING. LOW TEMPERATURES MID
50S NORTH TO LOWER 60S SOUTH.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 155 PM WEDNESDAY...
MODELS CONTINUE TO ADVERTISE THE CURRENT MID/UPPER TROUGH OVER THE
TENNESSEE VALLEY WILL PROGRESS SLOWLY EAST AND WEAKEN WITH TIME.
SURFACE HIGH PRESSURE WILL CONTINUE TO STRENGTHEN OVER OUR PIEDMONT
DAMMING REGION LOCALLY ENHANCED BY QPF TODAY AND TONIGHT. BY
12Z/THU... THE REMNANT MID/UPPER WAVE WILL SHIFT OFFSHORE AND THIS
WILL LEAVE A WEAK SURFACE HIGH PRESSURE IN PLACE FROM OFF THE NEW
ENGLAND COAST SOUTHWESTWARD INTO THE NC/SC PIEDMONT. CLEARING SHOULD
BE SLOW DUE TO THE LOW LEVEL RESIDUAL CAD EVENT AND THE WEAK
PRESSURE GRADIENT FOLLOWING THE UPPER TROUGH`S PASSAGE. WE WILL
MAINTAIN A LOW CHANCE OF LIGHT RAIN/DRIZZLE EARLY THURSDAY... WITH
OVERCAST SKIES EXPECTED TO BECOME PARTLY SUNNY DURING THE AFTERNOON.
HIGHS WILL SLOWLY RECOVER INTO THE LOWER TO MID 70S.
WEAK HIGH PRESSURE WILL LINGER OVER THE STATE THROUGH FRIDAY.
HOWEVER... THE MID/UPPER LEVEL FLOW WILL BEGIN TO BECOME MORE
AMPLIFIED WITH TIME AS AN UPPER LEVEL LOW AND TROUGH DIGS SE INTO
THE LOWER MISSISSIPPI VALLEY AND NORTHERN GULF COAST REGION FRI-FRI
NIGHT. THIS WILL MEAN AN INCREASING SW FLOW ALOFT AND AN INCREASE IN
MID AND HIGH LEVEL MOISTURE BEGINNING FRIDAY. EXPECT PARTLY CLOUDY
CONDITIONS THU NIGHT AND FRI. LOWS GENERALLY 52-57. HIGHS 75-80.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 220 AM WEDNESDAY...
...A POTENTIAL HEAVY RAIN EVENT THIS WEEKEND CONTINUES...
THE LATEST MODELS REMAIN ON COURSE FOR A VERY WET WEEKEND FOR OUR
REGION. WE WILL NOT STRAY FAR FROM THE HPC MODEL PREFERENCES WHICH
INCLUDE A BLEND OF THE MOST RECENT 00Z/GFS/12Z ECMWF/00Z UKMET
COMPROMISE WITH INCREASING CONFIDENCE. THIS WOULD FAVOR A STRONG
SURFACE LOW PRESSURE TRACK NE FROM THE NORTHERN GULF COAST SATURDAY
AFTERNOON... TO NEAR CHARLESTON OR SAVANNAH BY LATE SUNDAY... THEN
NEAR WILMINGTON 12Z/MONDAY. A LARGE FETCH OF DEEP MOISTURE FROM OFF
THE GULF OF MEXICO AND GULF STREAM/WESTERN ATLANTIC IS EXPECTED TO
BE TAPPED INTO THE SYSTEM AS IT APPROACHES. CURRENT INDICATIONS ARE
THAT THE SYSTEM MAY BE RELATIVELY SLOW MOVING DUE TO THE NATURE OF
DEEP SOUTH CUT OFF LOWS AND THE POTENTIAL FOR THE MORE SOUTHWESTERLY
TRENDS OF RECENT FAVORED MODELS IN THE DEVELOPMENT OF THE MID LEVEL
CUT OFF LOW.
RIGHT NOW... IT APPEARS THAT SHOWERS/ISO THUNDERSTORMS WILL
DEVELOP/OVERSPREAD NC FROM THE SOUTH SATURDAY AFTERNOON. PERIODS OF
RAIN ARE EXPECTED SATURDAY NIGHT AND SUNDAY. THERE MAY BE A LULL IN
THE RAIN IF THE MID LEVEL DRY SLOT AFFECTS THE REGION LATE SUNDAY...
WITH THE POTENTIAL FOR ADDITIONAL SHOWERS WITH THE UPPER LOW AGAIN
SUNDAY NIGHT INTO MONDAY. QPF OF 1-3 INCHES LOOKS FAVORABLE.
THE POTENTIAL FOR WIDESPREAD SOAKING RAIN AND EVEN SOME FLOODING
APPEAR TO BE THE MAIN WEATHER HAZARDS FOR THE UPCOMING WEEKEND
STORM. THE FLASH FLOOD GUIDANCE HAS BEEN HIGH (4+ INCHES IN 12 HOURS
AND 2+ INCHES IN NON-URBAN AREAS IN 1 HOUR) RECENTLY DUE TO THE LACK
OF RAIN IN THE PAST 2 WEEKS. HOWEVER... NW PIEDMONT ZONES HAD
LOCALLY 1 TO 1.5 INCHES OF RAIN LAST EVENING AND AN ADDITIONAL 0.5
TO 1 INCH WITH THE CURRENT EVENT WILL REALLY MAKE THOSE THRESHOLDS
COME DOWN. WHILE FLASH FLOODING WOULD NOT BE A MAJOR CONCERN
INITIALLY... IT MAY BECOME AN ISSUE BY LATE IN THE WEEKEND IF WE DO
GET THE PROJECTED SOAKING.
THE SEVERE THREAT WOULD BE MINIMAL GIVEN THE PROJECTED STORM TRACK.
THE BEST CHANCE OF THUNDERSTORMS WOULD BE SATURDAY (ON THE LEADING
EDGE OF THE DEEP MOISTURE SHIELD) ARRIVING FROM THE SOUTH DURING THE
AFTERNOON.
SENSIBLE WEATHER... MOSTLY CLOUDY FRIDAY NIGHT WITH A SLIGHT CHANCE
OF SHOWERS. LOWS 58-63. SHOWERS DEVELOPING SATURDAY... A CHANCE OF
THUNDERSTORMS. HIGHS IN THE 70S TO AROUND 80. PERIODS OF RAIN SAT
NIGHT AND SUNDAY. SLIGHT CHANCE OF THUNDERSTORMS. LOWS IN THE 60S.
HIGHS 65-75 N TO SE.
A CHANCE OF SHOWERS SUNDAY NIGHT AND MONDAY. LOWS 50S. HIGHS IN THE
60S. BECOMING MOSTLY SUNNY TUESDAY. HIGHS IN THE 60S.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 225 AM WEDNESDAY...
BETWEEN ONE LOW AMPLITUDE MID-LEVEL DISTURBANCE OVER SOUTHWESTERN VA
AND ANOTHER MORE POTENT ONE OVER THE GULF COAST STATES...A BRIEF
LULL IN THE CURRENT SHOWER AND THUNDERSTORM ACTIVITY AFFECTING THE
TRIAD TERMINALS (KINT/KGSO) AND KRDU SHOULD OCCUR BETWEEN
APPROXIMATELY 09Z-20Z TODAY...AND RESULT IN CONTINUED GENERALLY VFR
CONDITIONS AT ALL CENTRAL NC TERMINALS THROUGH MOST OF WEDNESDAY.
HOWEVER...THE CLOSER APPROACH OF THE AFOREMENTIONED MID-UPPER
DISTURBANCE FROM THE GULF COAST STATES...AND RESULTANT UPLIFT OF AIR
ATOP GENERALLY NORTHEASTERLY FLOW AT THE SURFACE...WILL RESULT IN
THE LOWERING OF CEILINGS TO MVFR RANGE -- AND THE DEVELOPMENT OF
LIGHT RAIN -- FROM WEST TO EAST ACROSS CENTRAL NC LATE THIS
AFTERNOON AND THIS EVENING. THE DEVELOPMENT OF THE RAIN AND
RESULTANT COLD AIR DAMMING SHOULD CAUSE CEILINGS AND VISIBILITIES TO
LOWER FURTHER TO IFR AND MVFR...RESPECTIVELY -- LOWEST AT TRIAD
TERMINALS -- OVERNIGHT.
OUTLOOK...CONDITIONS WILL GRADUALLY IMPROVE TO MVFR OR LOW VFR BY
EARLY THU AFTERNOON...BUT THE CONTINUED PRESENCE OF THE RESIDUAL
COLD AIR DAMMING HIGH PRESSURE RIDGE OVER THE MIDDLE ATLANTIC REGION
SUGGESTS AT LEAST A MEDIUM CHANCE OF THE REDEVELOPMENT OF IFR
CONDITIONS THU NIGHT. THEN SIMILAR TO THU...ANY IFR CONDITIONS
SHOULD GRADUALLY LIFT TO MVFR OR LOW VFR ON FRI. A POTENTIALLY
SIGNIFICANT STORM SYSTEM MAY AFFECT CENTRAL NC WITH ADVERSE AVIATION
CONDITIONS DURING THE WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BADGETT
NEAR TERM...RLH
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
220 AM EDT WED APR 18 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL APPROACH FROM THE WEST LATE TODAY AND
TONIGHT BRINGING UNSETTLED WEATHER TO THE REGION. A STRONG STORM
SYSTEM IS EXPECTED TO BRING THE THREAT OF HEAVY RAIN OVER THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 915 PM...
MOISTURE AND POTENTIAL ENERGY QUITE LIMITED WITH SCATTERED
CONVECTION LOW TOPPED AT THIS TIME. MOST MODELS CONTINUE TO
ATTEMPT TO DEVELOP PRECIPITATION TONIGHT ALONG THE BOUNDARY NEAR
SOUTH CAROLINA. HOWEVER THE RUC MODEL CONTINUES TO SHOW LIMITED
MOISTURE THROUGHOUT THE AIR COLUMN AND ONLY WEAK LOW LEVEL
CONVERGENCE IN THAT AREA. TO THE WEST CONVERGENCE LOCKED IN OVER
THE FOOTHILLS WITH MODELS OCCASIONALLY PRODUCING CONVERGENCE AND
LIFT IN THE WESTERN PIEDMONT. BEST CONVERGENCE WILL CONTINUE TO BE
OVER THE MOUNTAINS AND THE WESTERN FOOTHILLS TONIGHT. ISOLATED
RAINFALL AMOUNTS COULD BE IN EXCESS OF ONE INCH IN THE WEST... BUT
BASIN AVERAGES WILL GENERALLY BE QUITE LOW... AT A FEW HUNDREDTHS
OUTSIDE THE HEAVIEST SHOWERS. WILL LEAVE LOW LIKELY POPS IN THE
FAR WEST WITH CHANCE TO SLIGHT CHANCE POPS AS ONE MOVES EAST.
NORTHEAST FLOW WITH LOW LEVEL THICKNESSES AT SUNRISE WEDNESDAY
FALLING ABOUT 25 METERS FROM THIS MORNING. LOW TEMPERATURES MID
50S NORTH TO LOWER 60S SOUTH.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 155 PM WEDNESDAY...
MODELS CONTINUE TO ADVERTISE THE CURRENT MID/UPPER TROUGH OVER THE
TENNESSEE VALLEY WILL PROGRESS SLOWLY EAST AND WEAKEN WITH TIME.
SURFACE HIGH PRESSURE WILL CONTINUE TO STRENGTHEN OVER OUR PIEDMONT
DAMMING REGION LOCALLY ENHANCED BY QPF TODAY AND TONIGHT. BY
12Z/THU... THE REMNANT MID/UPPER WAVE WILL SHIFT OFFSHORE AND THIS
WILL LEAVE A WEAK SURFACE HIGH PRESSURE IN PLACE FROM OFF THE NEW
ENGLAND COAST SOUTHWESTWARD INTO THE NC/SC PIEDMONT. CLEARING SHOULD
BE SLOW DUE TO THE LOW LEVEL RESIDUAL CAD EVENT AND THE WEAK
PRESSURE GRADIENT FOLLOWING THE UPPER TROUGH`S PASSAGE. WE WILL
MAINTAIN A LOW CHANCE OF LIGHT RAIN/DRIZZLE EARLY THURSDAY... WITH
OVERCAST SKIES EXPECTED TO BECOME PARTLY SUNNY DURING THE AFTERNOON.
HIGHS WILL SLOWLY RECOVER INTO THE LOWER TO MID 70S.
WEAK HIGH PRESSURE WILL LINGER OVER THE STATE THROUGH FRIDAY.
HOWEVER... THE MID/UPPER LEVEL FLOW WILL BEGIN TO BECOME MORE
AMPLIFIED WITH TIME AS AN UPPER LEVEL LOW AND TROUGH DIGS SE INTO
THE LOWER MISSISSIPPI VALLEY AND NORTHERN GULF COAST REGION FRI-FRI
NIGHT. THIS WILL MEAN AN INCREASING SW FLOW ALOFT AND AN INCREASE IN
MID AND HIGH LEVEL MOISTURE BEGINNING FRIDAY. EXPECT PARTLY CLOUDY
CONDITIONS THU NIGHT AND FRI. LOWS GENERALLY 52-57. HIGHS 75-80.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 220 AM WEDNESDAY...
...A POTENTIAL HEAVY RAIN EVENT THIS WEEKEND CONTINUES...
THE LATEST MODELS REMAIN ON COURSE FOR A VERY WET WEEKEND FOR OUR
REGION. WE WILL NOT STRAY FAR FROM THE HPC MODEL PREFERENCES WHICH
INCLUDE A BLEND OF THE MOST RECENT 00Z/GFS/12Z ECMWF/00Z UKMET
COMPROMISE WITH INCREASING CONFIDENCE. THIS WOULD FAVOR A STRONG
SURFACE LOW PRESSURE TRACK NE FROM THE NORTHERN GULF COAST SATURDAY
AFTERNOON... TO NEAR CHARLESTON OR SAVANNAH BY LATE SUNDAY... THEN
NEAR WILMINGTON 12Z/MONDAY. A LARGE FETCH OF DEEP MOISTURE FROM OFF
THE GULF OF MEXICO AND GULF STREAM/WESTERN ATLANTIC IS EXPECTED TO
BE TAPPED INTO THE SYSTEM AS IT APPROACHES. CURRENT INDICATIONS ARE
THAT THE SYSTEM MAY BE RELATIVELY SLOW MOVING DUE TO THE NATURE OF
DEEP SOUTH CUT OFF LOWS AND THE POTENTIAL FOR THE MORE SOUTHWESTERLY
TRENDS OF RECENT FAVORED MODELS IN THE DEVELOPMENT OF THE MID LEVEL
CUT OFF LOW.
RIGHT NOW... IT APPEARS THAT SHOWERS/ISO THUNDERSTORMS WILL
DEVELOP/OVERSPREAD NC FROM THE SOUTH SATURDAY AFTERNOON. PERIODS OF
RAIN ARE EXPECTED SATURDAY NIGHT AND SUNDAY. THERE MAY BE A LULL IN
THE RAIN IF THE MID LEVEL DRY SLOT AFFECTS THE REGION LATE SUNDAY...
WITH THE POTENTIAL FOR ADDITIONAL SHOWERS WITH THE UPPER LOW AGAIN
SUNDAY NIGHT INTO MONDAY. QPF OF 1-3 INCHES LOOKS FAVORABLE.
THE POTENTIAL FOR WIDESPREAD SOAKING RAIN AND EVEN SOME FLOODING
APPEAR TO BE THE MAIN WEATHER HAZARDS FOR THE UPCOMING WEEKEND
STORM. THE FLASH FLOOD GUIDANCE HAS BEEN HIGH (4+ INCHES IN 12 HOURS
AND 2+ INCHES IN NON-URBAN AREAS IN 1 HOUR) RECENTLY DUE TO THE LACK
OF RAIN IN THE PAST 2 WEEKS. HOWEVER... NW PIEDMONT ZONES HAD
LOCALLY 1 TO 1.5 INCHES OF RAIN LAST EVENING AND AN ADDITIONAL 0.5
TO 1 INCH WITH THE CURRENT EVENT WILL REALLY MAKE THOSE THRESHOLDS
COME DOWN. WHILE FLASH FLOODING WOULD NOT BE A MAJOR CONCERN
INITIALLY... IT MAY BECOME AN ISSUE BY LATE IN THE WEEKEND IF WE DO
GET THE PROJECTED SOAKING.
THE SEVERE THREAT WOULD BE MINIMAL GIVEN THE PROJECTED STORM TRACK.
THE BEST CHANCE OF THUNDERSTORMS WOULD BE SATURDAY (ON THE LEADING
EDGE OF THE DEEP MOISTURE SHIELD) ARRIVING FROM THE SOUTH DURING THE
AFTERNOON.
SENSIBLE WEATHER... MOSTLY CLOUDY FRIDAY NIGHT WITH A SLIGHT CHANCE
OF SHOWERS. LOWS 58-63. SHOWERS DEVELOPING SATURDAY... A CHANCE OF
THUNDERSTORMS. HIGHS IN THE 70S TO AROUND 80. PERIODS OF RAIN SAT
NIGHT AND SUNDAY. SLIGHT CHANCE OF THUNDERSTORMS. LOWS IN THE 60S.
HIGHS 65-75 N TO SE.
A CHANCE OF SHOWERS SUNDAY NIGHT AND MONDAY. LOWS 50S. HIGHS IN THE
60S. BECOMING MOSTLY SUNNY TUESDAY. HIGHS IN THE 60S.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
AS OF 815 PM TUESDAY...
SHOWERS AND THUNDERSTORMS AND ASSOCIATED BRIEF SUB VFR
CONDITIONS... MAINLY AT KINT/KGSO DUE TO THE PROXIMITY OF A
SURFACE FRONT THERE...WILL REMAIN A POSSIBILITY THROUGH ABOUT 9 TO
11 PM... BEFORE DIMINISHING WITH THE LOSS OF DAYTIME HEATING AND
RESULTANT INSTABILITY. OTHERWISE...GENERALLY VFR CONDITIONS WILL
PERSIST THROUGH TONIGHT. MEANWHILE...THE APPROACH OF AN UPPER
LEVEL TROUGH ON WEDNESDAY WILL AID IN THE DEVELOPMENT OF LOWERING
CEILINGS AND RAIN POTENTIAL AS WARMER AIR TO OUR SOUTH RISES ATOP
COOLER AIR ASSOCIATED WITH A HIGH PRESSURE SYSTEM THAT WILL EXPAND
ACROSS VIRGINIA. ASSOCIATED CEILINGS WILL GRADUALLY LOWER TO MVFR
RANGE -- FIRST AT KFAY DURING THE MORNING HOURS -- THEN ELSEWHERE
THROUGH LATE AFTERNOON. IN ADDITION... FORECAST SOUNDINGS INDICATE
MOISTENING THROUGHOUT THE DEPTH OF THE ATMOSPHERE...WHICH SUGGESTS
THE AFOREMENTIONED PROBABILITY OF RAIN WILL ALSO INCREASE FROM
WEST TO EAST WITH THE APPROACH OF THE UPPER LEVEL TROUGH LATE IN
THE DAY. WINDS WILL REMAIN LIGHT FROM THE NORTHEAST THROUGH
WEDNESDAY.
OUTLOOK...MVFR CONDITIONS WILL LIKELY BECOME IFR OVERNIGHT
WEDNESDAY...AND PERSIST INTO AT LEAST EARLY THURSDAY IN
ASSOCIATION WITH THE DEVELOPMENT OF A COLD AIR DAMMING WEDGE.
WHEN THE COLD AIR DAMMING WEDGE WILL ERODE AND VFR CONDITIONS WILL
RETURN REMAINS DIFFICULT TO ASCERTAIN AT THIS TIME. IT IS POSSIBLE
THAT MVFR AND PERIODIC IFR (OVERNIGHT) CEILINGS MAY LINGER THROUGH
THURSDAY/FRIDAY IN ASSOCIATION WITH A REMNANT COLD AIR DAMMING
WEDGE AND LOW LEVEL SOUTHERLY RETURN FLOW. A POTENTIALLY
SIGNIFICANT STORM SYSTEM MAY AFFECT THE CAROLINAS OVER THE
WEEKEND...THOUGH UNCERTAINTY REMAINS HIGH WITH THIS SYSTEM AS
WELL.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BADGETT
NEAR TERM...RLH
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
324 AM EDT WED APR 18 2012
.SYNOPSIS...
A WAVE DEVELOPS AND AFFECTS MAINLY THE MOUNTAINS TODAY. HIGH
PRESSURE THURSDAY AND FRIDAY. A STORM SYSTEM FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THERE CONT TO BE SOME DISAGREEMENT WITH NW EXTENT OF MEASURABLE PCPN
THIS MORNING WITH THE NAM THE LONE GUN KEEP BULK OF QPF ACROSS THE
MTNS. MOST OTHER GUIDANCE HAS SHIFTED SOME TO NW WITH MEASURABLE
QPF...TAKING .1 TO .25 INCH CONTOUR THRU THE COAL FIELDS TO ABOUT
CRW AREA AND N UP I79 CORRIDOR. PLACEMENT OF LIFT AND FORCING
SIMILAR THOUGH. LOOKING AT MDL SOUNDINGS...ONE SEES WHERE NAM IS
HOLDING ON DRY AIR NEAR THE SFC W OF MTNS AS OTHER MDLS INCLUDING
THE RUC SATURATE THE COLUMN BY 12Z W TO CRW. LATEST RADAR MOSAIC
SHOWS SOLID AREA OF MAINLY -RA OVER SW VA AND S WV MTNS ATTM. THIS
IS TRYING TO PUSH NW SLOWLY BUT HAVING A HARD TIME GIVEN DRY AIR IN
FRONT OF IT. WILL NUDGE HIGHER POPS A HAIR NW 09-15Z THIS MORNING
BUT NOT AS MUCH AS MODEL CONSENSUS SUGGESTS WITH A BELIEF THE NAM
MAY BE HANDLING THE BL MOISTURE BETTER AS EVEN WHERE THERE IS RA OUT
THERE...NOT SEEING ANY VSBY RESTRICTIONS OR LOW CIGS CURRENTLY. WILL
CONT TO MONITOR NEXT FEW HRS FOR ANY FURTHER ADJUSTMENT TO NW.
OTHERWISE REMAINDER OF PREV FCST LOOKS GOOD. S/W TROF AXIS PUSHES
THRU THIS AFTN TAKING MUCH OF THE DEEP MOISTURE WITH IT AS SFC WAVE
PUSHES OFF TO NE. WILL GRADUALLY BRING POPS DOWN FROM W TO E THIS
AFTN...WITH AREA POP FREE BY 03Z. CONCERNING CLDS...WILL HOLD WV/SW
VA ZONES IN CLDS MUCH OF THE DAY AND ALLOW FOR SOME CLEARING ACROSS SE
OH/NE KY LATER IN AFTN. MAY SEE LOW STRATUS HOLD IN MTNS TONIGHT
WITH FG FOR ANY AREAS THAT RECEIVE RA THAT MANAGE TO CLR.
WILL LEAN TOWARD LWR NUMBERS FOR TDY GIVEN ABUNDANCE OF CLDS AND RA
ACROSS MTNS AND NUDGE TOWARD WARMER GUIDANCE ACROSS SE OH WHERE
SOME PARTIAL CLEARING MAY BE REALIZED THIS AFTN. WENT WITH WARMER
GUIDANCE FOR LOWS TONIGHT EAST OF OH RVR WITH SOME LINGERING CLDS.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
MODELS SHOW HIGH PRESSURE OVER THE REGION FOR THURSDAY AND FRIDAY.
FOR SATURDAY...MODELS DISAGREE WITH EACH OTHER AND CHANGE WITH EVERY
RUN. THIS DOES NOT LEAD TO A HIGH CONFIDENCE FORECAST. CURRENT
PACKAGE IS SUPPORTED BY THE CANADIAN MODEL...SO WILL STAY THE COURSE
FOR NOW UNTIL CONFIDENCE LEVELS INCREASE IN A SOLUTION.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AT THE OUTSET OF THE PERIOD FRIDAY EVENING A TROUGH WILL BE DIGGING
SOUTHWARD THROUGH THE CENTRAL CONUS...WITH POSITIVELY-TILTED AXIS
ROUGHLY FROM UPPER MID-WEST TO TEXAS. AT THE SURFACE A FRONT WILL BE
QUASI-STATIONARY TO THE NORTHWEST OF AREA OVER CENTRAL AND WESTERN
OHIO. TRIMMED BACK POPS OVER THE AREA FRI EVE WITH THIS IN MIND.
BOTH OPERATIONAL EXTENDED MODELS IS GOOD AGREEMENT WITH REGARD TO
THIS TROUGH CLOSING OFF ON ITS SOUTHERN END OVER THE SE TEXAS/LA
REGION BY SAT MORNING AND PROGRESSING THIS LOW EASTWARD ALONG THE
GULF COAST TOWARDS THE FLORIDA PANHANDLE BY EARLY SUN. GEFS MEAN
HEIGHT SOMEWHAT SURPRISINGLY KEEPS THIS LOW OPEN AND THEREFORE A BIT
MORE PROGRESSIVE...WITH ONLY FOUR OF ITS MEMBERS DEPICTING A CLOSURE
AT SUN 06Z. HOWEVER...BOTH NCEP AND EC ENSEMBLE MEAN HEIGHTS DO SHOW
THIS LOW CLOSING OFF AND THUS WILL BASE THE FORECAST ON THIS
SOLUTION.
SATURDAY THE UPPER LOW MOVING ACROSS THE GULF COAST WITH SFC
LOW...ALONG WITH A TROUGH MOVING ACROSS THE GREAT LAKES
REGION...WILL FINALLY ALLOW THE FRONT TO THE NORTHWEST TO BEGIN
PUSHING SE ACROSS THE AREA. STILL SOME DIFFERENCES IN TIMING BUT AT
THIS POINT THE FRONT IS EXPECTED TO BE AROUND THE OHIO RIVER AREA BY
18Z SAT AND NEAR THE EASTERN CWA BORDER BY 00Z SUN. LIFT AND
ABUNDANT LOW LEVEL MOISTURE STILL SUPPORT INCREASING CHANCES OF RAIN
SATURDAY AND SATURDAY EVENING. BEYOND THIS PERIOD MODELS BEGIN TO
DIVERGE WITH RESPECT TO THE DETAILS SURROUNDING CLOSED LOW AND
NORTHERN TROUGH...WITH THE GFS MORE PROGRESSIVE IN MOVING THE CLOSED
LOW NE AND INTO PHASE WITH THE DIVING NORTHERN TROUGH BY EARLY
MON...AND THE EC MUCH SLOWER IN PROGRESSION AND KEEPING THE TWO
SYSTEMS SEPARATE. NO REAL LEANING ONE WAY OR THE OTHER WHEN IT COMES
TO ENSEMBLES HERE...AND WITH NO REAL WAY TO DIFFERENTIATE AM
INCLINED TO BELIEVE THE SLOWER SOLN AS MODELS TEND TO BE MORE
PROGRESSIVE THAN REALITY WITH CLOSED SYSTEMS. THIS SOLUTION KEEPS
THE NORTHERN TROUGH DOMINANT IN ITS MOVING PRECIP EAST OF AREA
QUICKLY AFTER SUNDAY. HOWEVER...AGAIN WITH THE UNCERTAINTY I WILL
KEEP SOME MENTION OF POPS IN FOR MONDAY INTO TUESDAY.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
06Z WEDNESDAY TO 06Z THURSDAY...
S/W TROF MOVING THRU COMBINED WITH ISENTROPIC LIFT AND SFC WAVE
WILL PROVIDE FOR MAINLY -RA ACROSS THE MTNS THRU 18Z WITH
GENERALLY MVFR CIGS AND VSBY. EXCEPTION WILL ACROSS EASTERN SLOPES
WHERE SE FLOW NEAR SFC MAY ALLOW FOR IFR CIGS TDY. ELSEWHERE...-RA
MAY PUSH FURTHER W TO A KCRW TO KCKB LINE. HOWEVER EXPECTING
MAINLY VFR CONDITIONS WITH CIGS LOWERING INTO LOW END OF RANGE AND
VSBY REMAINING UNRESTRICTED. SYS SLOWLY PULLS E WITH GRADUAL
CLEARING ACROSS SE OH THIS AFTN. CLDS WILL HANG TOUGH E OF OH RVR
THRU 00Z AS LLVL MOISTURE SLOW TO DEPART. EXPECT MVFR CIGS OVER
MTNS TO LWR INTO IFR TONIGHT WITH VSBY APPROACHING IFR AS
WELL...INCLUDING KBKW. LIFR STRATUS POSSIBLE ACROSS EASTERN SLOPES
AFTER 06Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF MVFR CIGS THIS MORNING
AND TDY. EXTENT OF -RA MAY VARY. IFR CIGS MAY EXPAND FURTHER W
FROM EASTERN SLOPES TDY TO INCLUDE KBKW.
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 WED 04/18/12
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 M M M M H H H H H
HTS CONSISTENCY H H H H H M H H H H H H
BKW CONSISTENCY M M L L L M M L L L L M
EKN CONSISTENCY H H H M M M M 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 THURSDAY...
IFR CONDITIONS TONIGHT SOUTHWEST VIRGINIA AND THE SOUTHERN WV
MOUNTAINS.
IFR CONDITIONS POSSIBLE FRIDAY NIGHT AND SATURDAY IN CLOUDS AND
PRECIPITATION.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...50
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
209 AM EDT WED APR 18 2012
.SYNOPSIS...
A WAVE DEVELOPS AND AFFECTS MAINLY THE MOUNTAINS TODAY. HIGH
PRESSURE THURSDAY. A STORM SYSTEM FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THERE CONT TO BE SOME DISAGREEMENT WITH NW EXTENT OF MEASURABLE PCPN
THIS MORNING WITH THE NAM THE LONE GUN KEEP BULK OF QPF ACROSS THE
MTNS. MOST OTHER GUIDANCE HAS SHIFTED SOME TO NW WITH MEASURABLE
QPF...TAKING .1 TO .25 INCH CONTOUR THRU THE COAL FIELDS TO ABOUT
CRW AREA AND N UP I79 CORRIDOR. PLACEMENT OF LIFT AND FORCING
SIMILAR THOUGH. LOOKING AT MDL SOUNDINGS...ONE SEES WHERE NAM IS
HOLDING ON DRY AIR NEAR THE SFC W OF MTNS AS OTHER MDLS INCLUDING
THE RUC SATURATE THE COLUMN BY 12Z W TO CRW. LATEST RADAR MOSAIC
SHOWS SOLID AREA OF MAINLY -RA OVER SW VA AND S WV MTNS ATTM. THIS
IS TRYING TO PUSH NW SLOWLY BUT HAVING A HARD TIME GIVEN DRY AIR IN
FRONT OF IT. WILL NUDGE HIGHER POPS A HAIR NW 09-15Z THIS MORNING
BUT NOT AS MUCH AS MODEL CONSENSUS SUGGESTS WITH A BELIEF THE NAM
MAY BE HANDLING THE BL MOISTURE BETTER AS EVEN WHERE THERE IS RA OUT
THERE...NOT SEEING ANY VSBY RESTRICTIONS OR LOW CIGS CURRENTLY. WILL
CONT TO MONITOR NEXT FEW HRS FOR ANY FURTHER ADJUSTMENT TO NW.
OTHERWISE REMAINDER OF PREV FCST LOOKS GOOD. S/W TROF AXIS PUSHES
THRU THIS AFTN TAKING MUCH OF THE DEEP MOISTURE WITH IT AS SFC WAVE
PUSHES OFF TO NE. WILL GRADUALLY BRING POPS DOWN FROM W TO E THIS
AFTN...WITH AREA POP FREE BY 03Z. CONCERNING CLDS...WILL HOLD WV/SW
VA ZONES IN CLDS MUCH OF THE DAY AND ALLOW FOR SOME CLRING ACROSS SE
OH/NE KY LATER IN AFTN. MAY SEE LOW STRATUS HOLD IN MTNS TONIGHT
WITH FG FOR ANY AREAS THAT RECEIVE RA THAT MANAGE TO CLR.
WILL LEAN TOWARD LWR NUMBERS FOR TDY GIVEN ABUNDANCE OF CLDS AND RA
ACROSS MTNS AND NUDGE TOWARD WARMER GUIDANCE ACROSS SE OH WHERE
SOME PARTIAL CLRING MAY BE REALIZED THIS AFTN. WENT WITH WARMER
GUIDANCE FOR LOWS TONIGHT EAST OF OH RVR WITH SOME LINGERING CLDS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
IN GENERAL...WILL SEE ANY LINGERING PRECIPITATION ON WEDNESDAY NIGHT
MOVE OUT OF THE AREA...WITH HIGH PRESSURE TAKING OVER FOR THE
REMAINDER OF THE WORK WEEK. WITH THE SURFACE HIGH MAINLY EAST OF THE
CWA...SOUTHERLY FLOW WILL BRING A WARMING TREND THROUGH THURSDAY AND
FRIDAY.
THE 12Z NAM12 TRIES TO POP SOME DIURNAL TYPE SHOWERS ACROSS THE
MOUNTAINS THROUGH THE SHORT TERM...HOWEVER THIS WAS NOT REALLY
PRESENT IN PREVIOUS RUNS...AND NOT SEEING ANYTHING IN THE 12Z GFS TO
THIS EFFECT SO WILL LEAVE THINGS DRY UNTIL LATE IN THE DAY FRIDAY.
START TO INCREASE POPS ACROSS SE OHIO LATE FRIDAY AFTERNOON INTO THE
EVENING EVENING..AHEAD OF THE WEEKEND SYSTEM.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AT THE OUTSET OF THE PERIOD FRIDAY EVENING A TROUGH WILL BE DIGGING
SOUTHWARD THROUGH THE CENTRAL CONUS...WITH POSITIVELY-TILTED AXIS
ROUGHLY FROM UPPER MID-WEST TO TEXAS. AT THE SURFACE A FRONT WILL BE
QUASI-STATIONARY TO THE NORTHWEST OF AREA OVER CENTRAL AND WESTERN
OHIO. TRIMMED BACK POPS OVER THE AREA FRI EVE WITH THIS IN MIND.
BOTH OPERATIONAL EXTENDED MODELS IS GOOD AGREEMENT WITH REGARD TO
THIS TROUGH CLOSING OFF ON ITS SOUTHERN END OVER THE SE TEXAS/LA
REGION BY SAT MORNING AND PROGRESSING THIS LOW EASTWARD ALONG THE
GULF COAST TOWARDS THE FLORIDA PANHANDLE BY EARLY SUN. GEFS MEAN
HEIGHT SOMEWHAT SURPRISINGLY KEEPS THIS LOW OPEN AND THEREFORE A BIT
MORE PROGRESSIVE...WITH ONLY FOUR OF ITS MEMBERS DEPICTING A CLOSURE
AT SUN 06Z. HOWEVER...BOTH NCEP AND EC ENSEMBLE MEAN HEIGHTS DO SHOW
THIS LOW CLOSING OFF AND THUS WILL BASE THE FORECAST ON THIS
SOLUTION.
SATURDAY THE UPPER LOW MOVING ACROSS THE GULF COAST WITH SFC
LOW...ALONG WITH A TROUGH MOVING ACROSS THE GREAT LAKES
REGION...WILL FINALLY ALLOW THE FRONT TO THE NORTHWEST TO BEGIN
PUSHING SE ACROSS THE AREA. STILL SOME DIFFERENCES IN TIMING BUT AT
THIS POINT THE FRONT IS EXPECTED TO BE AROUND THE OHIO RIVER AREA BY
18Z SAT AND NEAR THE EASTERN CWA BORDER BY 00Z SUN. LIFT AND
ABUNDANT LOW LEVEL MOISTURE STILL SUPPORT INCREASING CHANCES OF RAIN
SATURDAY AND SATURDAY EVENING. BEYOND THIS PERIOD MODELS BEGIN TO
DIVERGE WITH RESPECT TO THE DETAILS SURROUNDING CLOSED LOW AND
NORTHERN TROUGH...WITH THE GFS MORE PROGRESSIVE IN MOVING THE CLOSED
LOW NE AND INTO PHASE WITH THE DIVING NORTHERN TROUGH BY EARLY
MON...AND THE EC MUCH SLOWER IN PROGRESSION AND KEEPING THE TWO
SYSTEMS SEPARATE. NO REAL LEANING ONE WAY OR THE OTHER WHEN IT COMES
TO ENSEMBLES HERE...AND WITH NO REAL WAY TO DIFFERENTIATE AM
INCLINED TO BELIEVE THE SLOWER SOLN AS MODELS TEND TO BE MORE
PROGRESSIVE THAN REALITY WITH CLOSED SYSTEMS. THIS SOLUTION KEEPS
THE NORTHERN TROUGH DOMINANT IN ITS MOVING PRECIP EAST OF AREA
QUICKLY AFTER SUNDAY. HOWEVER...AGAIN WITH THE UNCERTAINTY I WILL
KEEP SOME MENTION OF POPS IN FOR MONDAY INTO TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
06Z WEDNESDAY TO 06Z THURSDAY...
S/W TROF MOVING THRU COMBINED WITH ISENTROPIC LIFT AND SFC WAVE
WILL PROVIDE FOR MAINLY -RA ACROSS THE MTNS THRU 18Z WITH
GENERALLY MVFR CIGS AND VSBY. EXCEPTION WILL ACROSS EASTERN SLOPES
WHERE SE FLOW NEAR SFC MAY ALLOW FOR IFR CIGS TDY. ELSEWHERE...-RA
MAY PUSH FURTHER W TO A KCRW TO KCKB LINE. HOWEVER EXPECTING
MAINLY VFR CONDITIONS WITH CIGS LWRING INTO LOW END OF RANGE AND
VSBY REMAINING UNRESTRICTED. SYS SLOWLY PULLS E WITH GRADUAL
CLRING ACROSS SE OH THIS AFTN. CLDS WILL HANG TOUGH E OF OH RVR
THRU 00Z AS LLVL MOISTURE SLOW TO DEPART. EXPECT MVFR CIGS OVER
MTNS TO LWR INTO IFR TONIGHT WITH VSBY APPROACHING IFR AS
WELL...INCLUDING KBKW. LIFR STRATUS POSSIBLE ACROSS EASTERN SLOPES
AFTER 06Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF MVFR CIGS THIS MORNING
AND TDY. EXTENT OF -RA MAY VARY. IFR CIGS MAY EXPAND FURTHER W
FROM EASTERN SLOPES TDY TO INCLUDE KBKW.
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 WED 04/18/12
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 M M M M H H H H H
HTS CONSISTENCY H H H H H M H H H H H H
BKW CONSISTENCY M M L L L M M L L L L M
EKN CONSISTENCY H H H M M M M 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 THURSDAY...
IFR CONDITIONS TONIGHTN SOUTHWEST VIRGINIA AND THE SOUTHERN WV
MOUNTAINS.
IFR CONDITIONS POSSIBLE FRIDAY NIGHT AND SATURDAY IN CLOUDS AND
PRECIPITATION.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...30
SHORT TERM...MZ
LONG TERM...50
AVIATION...30
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
330 AM CDT WED APR 18 2012
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
330 AM CDT WED APR 18 2012
FIRST CONCERN WILL BE SHOWERS/THUNDERSTORMS TODAY...THEN RAIN AGAIN
THURSDAY INTO THURSDAY NIGHT WITH PERHAPS SOME SNOW MIXING IN
THURSDAY NIGHT. LOOK FOR A CHANCE OF LINGERING RAIN/SHOWERS ON
FRIDAY AS WELL.
CURRENT WATER VAPOR IMAGERY SHOWING A RATHER DYNAMIC MID-LEVEL WAVE
PUSHING INTO WESTERN MN. AT THE SURFACE...LOW PRESSURE WAS LOCATED
OVER SOUTHWEST MN WITH WARM AIR ADVECTION/STRONG ISENTROPIC LIFT AND
MOISTURE TRANSPORT PRODUCING SCATTERED SHRA/TS ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY REGION. SO FAR MOST OF THIS ACTIVITY HAS
BEEN CONFINED ALONG/NORTH OF I-90. MEANWHILE...THE COLD FRONT FROM
THE LOW WAS PRODUCING A DECENT LINE OF THUNDERSTORMS FROM SOUTHWEST
MN INTO NORTHEAST NEB. OTHERWISE...UNDER MOSTLY CLOUDY
SKIES...TEMPERATURES AT 3 AM ACROSS THE AREA WERE IN THE MID 40S TO
MID 50S.
FOR TODAY...WILL BE WATCHING THAT LOW AND COLD FRONT TRACK EAST
ACROSS THE AREA AS THE NAM HAS 0-3KM MUCAPE INCREASING INTO THE
800-1100 J/KG RANGE THIS MORNING AND AFTERNOON. THERE IS ALSO AMPLE
SHEAR PRESENT IN THIS LAYER IN THE 35-40KT RANGE. BUFKIT ALSO
SHOWING MOST OF THIS ACTIVITY FAIRLY HIGH BASED. SO...THINKING THERE
MAY BE AN OUTSIDE CHANCE OF SOME SUB-SEVERE HAIL/WIND WITH A FEW OF
THESE STORMS. HIGHEST THREAT AREA FOR THIS OCCURRING LOOKS TO BE
SOUTHEAST OF A LINE FROM NEAR SPARTA AND VIROQUA WI...TO NEAR
OELWEIN IA. OTHERWISE...LOOK FOR GUSTY SOUTHWEST WINDS THIS MORNING
IN THE 15-30 MPH RANGE SHIFT TO THE WEST/NORTHWEST THIS AFTERNOON
WITH HIGHS TOPPING OFF WELL INTO THE 60S.
FOR TONIGHT...WILL SEE CLEARING EARLY IN THE EVENING WITH THE COLD
FRONT SLIDING SOUTHEAST OF THE AREA AND THEN STALLING OUT ACROSS NORTHERN
IL INTO CENTRAL IA. WEAK CYCLOGENESIS OVER THE CENTRAL PLAINS WILL
THEN PRODUCE ISENTROPIC LIFT/MOISTURE TRANSPORT ACROSS THIS FRONTAL
BOUNDARY FOR INCREASING CLOUDS AGAIN AFTER MIDNIGHT. ANY RAIN LOOKS
LIKE IT WILL HOLD OFF SOUTH/WEST OF THE AREA. INCREASING ISENTROPIC
LIFT/MOISTURE TRANSPORT AHEAD OF THE THE WEAK WAVE OF LOW PRESSURE
OVER THE PLAINS SPREADS RAIN INTO THE AREA ON THURSDAY. NAM STILL
SHOWING SOME WEAK ELEVATED CAPE IN THE 850-700MB LAYER FOR PERHAPS
AN ISOLATED CLAP OR TWO OF THUNDER EMBEDDED IN THE RAIN SHIELD.
OTHERWISE...EASTERLY FLOW AND RAIN WILL MAKE FOR A RATHER RAW DAY
WITH HIGHS STRUGGLING INTO THE UPPER 40S TO MIDDLE 50S.
THE WAVE OF LOW PRESSURE MOVES ACROSS NORTHERN IL THURSDAY
NIGHT..DRAGGING COOLER AIR IN ACROSS THE REGION. THIS IS EXPECTED TO
PRODUCE A COOLING DEFORMATION AREA WITH A PERHAPS A MIX OF A
RAIN/SNOW ACROSS PORTIONS OF THE AREA LATE IN THE NIGHT. NO SNOW
ACCUMULATION IS EXPECTED THOUGH.
ON FRIDAY...THE LOW TRACK EAST INTO THE EASTERN GREAT LAKES REGION
WITH PERHAPS SOME LINGERING DEFORMATION PRECIPITATION IN THE
MORNING. MEANWHILE...THE COOL/RATHER DEEP MID-LEVEL TROUGH TRACKS
OVER OUR AREA DURING THE DAY. THE NAM QPF AND NAM BUFKIT HINTS AT
SOME SHOWER ACTIVITY UNDER THIS COLDER/CYCLONIC FLOW ALOFT. HELD
ONTO SOME LOWER-END 20-40 POPS TO HONOR THIS SIGNAL. LOOK FOR
CHILLIER THAN NORMAL HIGHS IN THE UPPER 40S TO LOWER 50S AS WELL.
CLEARING THEN EXPECTED FRIDAY NIGHT AS A WEAK RIDGE OF HIGH PRESSURE
DRIFTS ACROSS THE REGION WITH LOWS DIPPING INTO THE UPPER 20S TO
LOWER 30S. WILL HAVE TO KEEP THIS IN MIND FOR POSSIBLE FROST/FREEZE
HEADLINES.
.LONG TERM...SATURDAY THROUGH TUESDAY
330 AM CDT WED APR 18 2012
18.00Z GFS AND ECMWF IN PRETTY GOOD AGREEMENT THROUGH THE LONG TERM.
BOTH MODELS HAVE SATURDAY DRY WITH SURFACE RIDGE HOLDING ACROSS THE
AREA. TEMPERATURES STILL A BIT ON THE COOL SIDE THE THOUGH WITH
HIGHS IN THE LOW-MID 50S. WARM AIR ADVECTION AHEAD OF A WEAK
MID-LEVEL WAVE IN THE NORTHWEST FLOW ALOFT WILL INCREASE CLOUDS AND
PRODUCE A CHANCE OF -SHRA SATURDAY NIGHT. THIS WILL BE MAINLY
NORTHWEST OF A MEDFORD THROUGH WINONA AND DODGE CENTER LINE. THIS
WAVE WILL THEN PRODUCE A CHANCE OF SHRA THROUGH SATURDAY MAINLY EAST
OF THE MISSISSIPPI RIVER. SUNDAY NIGHT THROUGH MONDAY WILL SEE WARM
AIR ADVECTION ACROSS THE AREA WITH HIGHS MONDAY INCREASING INTO THE
UPPER 50S TO MIDDLE 60S. MODELS THEN SHOW A BIT MORE VIGOROUS
MID-LEVEL/SURFACE LOW PUSHING ACROSS SOUTHERN CANADA AND THE
NORTHERN PLAINS...TOWARD THE AREA MONDAY NIGHT THROUGH TUESDAY FOR A
CHANCE OF SHOWERS AND THUNDERSTORMS. LOOK FOR HIGHS ON TUESDAY WELL
INTO THE 60S.
&&
.AVIATION...
1130 PM CDT TUE APR 17 2012
THE SFC PRESSURE GRADIENT WILL TIGHTEN ACROSS THE REGION DURING THE
EARLY MORNING HOURS AS A COLD FRONT APPROACHES FROM THE NORTHERN
PLAINS. LITTLE IF ANY DECOUPLING GOING ON...SO EXPECT INCREASING
WINDS OVERNIGHT...AND WOULD NOT BE SURPRISED IF THERE WAS SOME
GUSTINESS FROM TIME TO TIME. LOOKING FOR A SHIFT FROM SOUTH TO WEST
WITH THE FRONTAL PASSAGE...16-18Z AT KRST AND 19-21Z AT KLSE. IT
SHOULD ALSO BE NOTED THAT THE LOW LEVEL WINDS WILL ALSO BE
STRONG...WITH RUC13/NAM12 BUFKIT SOUNDINGS POINTING TO 19050KT NEAR
1500 FT THROUGH 12Z.
CLOUDS WILL BE ON THE INCREASE...WITH A GRADUAL LOWERING IN THE CIGS
AS THE FRONT NEARS. COULD SEE A FEW HOURS OF MVFR JUST AHEAD OF THE
FRONT.
WHILE THE BEST UPPER LEVEL FORCING WILL STAY NORTH...THE LOW LEVEL
JET/MOISTURE TRANSPORT WAS ALREADY SPARKING -SHRA AHEAD OF THE
FRONT...ALA LATEST 88-D RETURNS. THERE WAS SOME ISOLATED TS ALSO.
THE LATEST HRRR AND NAM12 HAVE SPED THE SYSTEM UP A BIT...AND HAVE
PUSHED UP THE MORE LIKELY PERIODS FOR -SHRA AS A RESULT. HAVE OPTED
TO LEAVE ANY TS OUT FOR NOW AS COVERAGE FOR THUNDER LOOKS SPOTTY AT
THE MOMENT...AND INSTABILITY IS LIMITED THROUGH THE MORNING HOURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
330 AM CDT WED APR 18 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM... DAS
LONG TERM.... DAS
AVIATION..... RIECK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1104 AM EDT WED APR 18 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE GREAT LAKES WILL BUILD TO THE EAST OVER THE
AREA INTO THURSDAY. WEAK HIGH PRESSURE BUILDS OFFSHORE ON FRIDAY.
AN APPROACHING FRONTAL SYSTEM AND WAVES OF LOW PRESSURE FORMING
ALONG THE FRONT WILL IMPACT THE REGION OVER THE WEEKEND AND INTO
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MID TO HIGH CLOUDS OVER WESTERN PORTIONS OF THE CWA ARE STRUGGLING
TO PUSH INTO EASTERN PORTIONS OF THE CWA IN RESPONSE TO A MINI
700-500 HPA RIDGE OVER THE EAST. WITH THIS FEATURE FORECAST TO
PUSH TO THE EAST...WOULD EXPECT THE CLOUDS TO OVERSPREAD EASTERN
PARTS OF THE AREA THIS AFTERNOON...WITH MOST AREAS MOSTLY
CLOUDY/PARTLY SUNNY.
KEPT THE FORECAST DRY FOR TODAY AS 12Z SOUNDINGS AT KALY AND KOKX
SHOW VERY DRY LOW LEVELS...SO WOULD ONLY EXPECT SOME VIRGA OVER
WESTERN PORTIONS OF THE CWA THIS AFTERNOON.
FOR HIGHS...WITH CLOUD COVER A BIT MORE EXPANSIVE THAN ORIGINALLY
EXPECTED...HAVE TWEAKED THEM DOWN A DEGREE OR TWO FOR
NOW...CONSISTENT WITH A BLEND OF MIXING DOWN FROM 900 HPA...NAM
2-METER TEMPERATURES AND A BLEND OF MET AND MAV GUIDANCE.
DEPENDING ON EXACTLY HOW THE CLOUD COVER PLAYS OUT...MIGHT HAVE TO
LOWER A BIT MORE WITH THE NEXT UPDATE.
MADE MINOR CHANGES IN SEABREEZE TIMING FOR THIS
AFTERNOON...STARTING IT 1-2 HOURS EARLY BASED ON BLEND OF
CONSISTENT HRRR AND NAM 10M WINDS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
THE QUIET CONDITIONS CONTINUE TONIGHT WITH THE HIGH PRESSURE MOVING
THROUGH THE NORTHEAST AND SETTLING OFFSHORE TO THE EAST THURSDAY. AS
THE HIGH MOVES...WINDS WILL SHIFT TO A MORE PERSISTENT SOUTHERLY
FLOW AND INCREASE...THOUGH STILL REMAINING LESS THAN 10 KTS.
THE 00Z GFS BRINGS IN POPS FOR THE WESTERN CWA TONIGHT WITH LOW
PRESSURE AT 700MB PUSHING IN FROM THE SOUTH BETWEEN 03Z AND 09Z. THE
12Z ECMWF AND 00Z NAM HINT AT THIS AS WELL...BUT KEEP ALL PRECIP TO
THE SOUTH WITH THE BETTER UPPER LEVEL FORCING. DID NOT INCLUDE ANY
PRECIP FOR TONIGHT...SIDING MORE WITH THE ECMWF AND NAM.
HOWEVER...THE MOISTURE AT THE 700MB WILL LEAD TO DEVELOPMENT OF
MID TO HIGH LEVEL CLOUDS OVER THE SOUTHERN PARTS OF THE
CWA...WHILE SUBSIDENCE ALOFT WILL HELP TO SCATTER SKIES IN THE
NORTHERN PORTION OF THE CWA. THIS MOISTURE PUSHES THROUGH BY
THURSDAY MORNING...AND WITH THE UPPER LEVEL SUBSIDENCE
CONTINUING...SHOULD SEE PARTLY CLOUDY SKIES THURSDAY.
925MB AND 850MB FLOW BECOMES MORE WSW TONIGHT AND THURSDAY...ONCE
AGAIN ALLOWING FOR WARMER TEMPS TO BE INJECTED IN. TEMPS WILL BE A
FEW DEGREES ABOVE NORMAL...USING A MOS/NAM BLEND ONCE AGAIN.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
FORECAST CHALLENGE CONTINUES TO BE WITH A DEVELOPING STORM SYSTEM
OVER THE EASTERN THIRD OF THE COUNTRY THIS WEEKEND. BOTH THE 00Z GFS
AND ECMWF HAVE TRENDED SLOWER...DEEPER...AND WETTER WITH THE SYSTEM
WHICH WILL IMPACT THE AREA SAT-MON. THERE IS THE POTENTIAL FOR
SEVERAL INCHES OF RAINFALL. WHILE MUCH NEEDED...ANY LARGE AMOUNT OF
RAINFALL OVER A SHORT PERIOD TIME DOES RAISE FLOODING CONCERNS.
THERE STILL IS UNCERTAINTY WITH THE LOCATION AND MAGNITUDE OF THE
CUTOFF LOW THAT FORMS OVER THE MID ATLANTIC STATES...AS WELL AS WITH
THE RESULTANT SURFACE LOW AND COASTAL FRONT. THESE DETAILS WILL BE
BETTER REFINED AS WE GET CLOSER TO THE EVENT.
INITIALLY...A NEARLY ZONAL FLOW STARTS OUT THU NIGHT...THEN SHORT
WAVE ENERGY OVER THE PLAINS SPLITS ACROSS THE LOWER MS VALLEY AND
OHIO VALLEY STATES. SUBSEQUENT SHORT WAVE ENERGY DIGS INTO THE
NORTHERN BRANCH TROUGH. THIS AMPLIFICATION EVENTUALLY LEADS TO PHASING
WITH THE SOUTHERN BRANCH. NEEDLESS TO SAY...SOME COMPLEX
INTERACTIONS GOING ON HERE...BUT TO SEE THE 00Z GUIDANCE POINTING
IN THIS DIRECTION DOES MAKE THE SOLUTION MORE CREDIBLE. THERE ALSO
APPEARS TO BE A FEED OF BOTH GULF OF MEXICO AND TROPICAL ATLANTIC
MOISTURE INTO THE SYSTEM.
THE WEEK WILL END ON A DRY NOTE WITH HIGH PRESSURE BUILDING
OFFSHORE. A PAC FRONTAL SYSTEM APPROACHES FRI NIGHT INTO
SAT...BECOMING NEARLY STATIONARY ALONG THE EAST COAST OVER THE
WEEKEND. THE 12Z MODEL RUN WAS MORE PROGRESSIVE IN ALLOWING THE
FRONT TO PUSH OFFSHORE SUN MORNING. THIS IS CURRENTLY REFLECTED IN
THE GRIDS WITH WINDS BECOMING NE...HOWEVER THE 00Z ECMWF SUPPORTS
THE GFS WITH A SLOWER PROGRESSION. THUS...THE FLOW MAY REMAIN
SOUTHERLY INTO EARLY NEXT WEEK UNTIL DEEPENING LOW PRESSURE PASSES
TO THE NORTH AND WEST. BEFORE MAKING LARGE WHOLESALE CHANGES...WOULD
LIKE TO SEE SOME CONTINUITY MAINTAINED WITH THE 12Z CYCLE. THE BEST
CHANCE FOR RAIN AT THIS TIME APPEARS TO BE FROM SAT NIGHT INTO MON.
AS FOR TEMPS...REMAINING SEVERAL DEGREES ABOVE NORMAL FRI AND SAT.
RAIN COOLED AIR WILL RESULT IN DAYTIME HIGHS SUN-TUE NEAR
NORMAL...WITH OVERNIGHT LOWS A FEW DEGREES ABOVE NORMAL DUE TO THE
CLOUD COVER.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
HIGH PRES BUILDS OVER THE AREA TODAY. VFR THROUGH THE TAF PERIOD.
NORTHERLY WINDS WILL BRIEFLY BECOME L/V 15-16Z AS HIGH PRES MOVES
OVERHEAD...THEN WILL SHIFT TO THE SOUTH AT AROUND 10 KT WITH HIGH
PRES OVER THE AREA THIS AFTERNOON. SOUTH WINDS FORECAST FIRST
FOR COASTAL CT TERMINALS AROUND 17Z...THEN KJFK...KISP AROUND 18Z
AND KLGA NEAR 19-20Z WITH INLAND TERMINALS SUCH AS KEWR/KTEB/KHPN
LAST AT ABOUT 20Z. WINDS DIMINISH AFTER SUNSET.
SOME LIGHT PRECIP MAY SPREAD INTO THE TERMINALS LATE TONIGHT. WILL
NOT INCLUDE IN TAF PACKAGE AT THIS TIME DUE TO LOW CONFIDENCE IN
PRECIP OCCURRING...AND LOW CONFIDENCE ON IMPACTS FROM ANY PRECIP
THAT WOULD DEVELOP.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: HIGH CONFIDENCE IN VFR. LOWER CONFIDENCE IN
WINDS. AMENDMENTS POSSIBLE TIMING OF SOUTHERLY WIND SHIFT...WHICH
COULD OCCUR WITHIN AN HOUR OR TWO OF FORECASTED TIME.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: HIGH CONFIDENCE IN VFR. LOWER CONFIDENCE IN
WINDS. AMENDMENTS POSSIBLE TIMING OF SOUTHERLY WIND SHIFT...WHICH
COULD OCCUR WITHIN AN HOUR OF FORECASTED TIME.
KLGA FCSTER COMMENTS: HIGH CONFIDENCE IN VFR. LOWER CONFIDENCE IN
WINDS. AMENDMENTS POSSIBLE TIMING OF SOUTHERLY WIND SHIFT...WHICH
COULD OCCUR WITHIN AN HOUR OR TWO OF FORECASTED TIME.
KTEB FCSTER COMMENTS: HIGH CONFIDENCE IN VFR. LOWER CONFIDENCE IN
WINDS. AMENDMENTS POSSIBLE TIMING OF SOUTHERLY WIND SHIFT...WHICH
COULD OCCUR WITHIN AN HOUR OR TWO OF FORECASTED TIME.
KHPN FCSTER COMMENTS: HIGH CONFIDENCE IN VFR. LOWER CONFIDENCE IN
WINDS. AMENDMENTS POSSIBLE TIMING OF SOUTHERLY WIND SHIFT...WHICH
COULD OCCUR WITHIN AN HOUR OR TWO OF FORECASTED TIME.
KISP FCSTER COMMENTS: HIGH CONFIDENCE IN VFR. LOWER CONFIDENCE IN
WINDS. AMENDMENTS POSSIBLE TIMING OF SOUTHERLY WIND SHIFT...WHICH
COULD OCCUR WITHIN AN HOUR OF FORECASTED TIME.
OUTLOOK FOR 14Z THURSDAY THROUGH SUNDAY...
.THU-FRI NIGHT...VFR.
.SAT...CIGS BELOW 3000 FT POSSIBLE.
.SUN...IFR POSSIBLE IN RAIN. GUSTY NE WINDS POSSIBLE AS WELL.
&&
.MARINE...
MINOR CHANGES MADE TO THE GRIDS TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
HIGH PRESSURE OVER THE REGION WILL HELP TO KEEP CONDITIONS ON THE
WATERS SUB-SCA THROUGH THURSDAY. WINDS WILL BEGIN INCREASING FROM THE
SOUTH THURSDAY...BUT GUSTS SHOULD REMAIN LESS THAN 20 KTS. SEAS WILL
ALSO BEGIN BUILDING WITH THE INCREASING WINDS...WITH UP TO 5 FT
SEAS POSSIBLE BY THURSDAY NIGHT ON THE OCEAN WATERS.
A PROLONGED SOUTHERLY FLOW THU NIGHT INTO SAT WILL RESULT IN SEAS
JUST BELOW SCA CRITERIA ON THE OCEAN. THE FORECAST CHALLENGE AT THIS
TIME IS WITH THE LOW TRACK LATE IN THE WEEKEND. MODELS HAVE TRENDED
DEEPER AND FARTHER WEST WITH THE LOW TRACK. SHOULD THIS HAPPEN...A
WIND SHIFT TO THE NE ON SUN WOULD NOT HAPPEN. PREFER TO SEE RUN TO
RUN CONTINUITY WITH THE 12Z MODEL CYCLE BEFORE DISCOUNTING THE WIND
SHIFT AND KEEPING THE FLOW SOUTHERLY. REGARDLESS...A STRENGTHENING
SOUTHERLY FLOW WITH A LONG FETCH WOULD ALSO PUSH THE SEAS TO ABOVE 5
FT.
&&
.FIRE WEATHER...
DRY CONDITIONS CONTINUE INTO TODAY...WITH RELATIVE HUMIDITY LEVELS
IN THE 20-35 PERCENT RANGE. HOWEVER...AS HIGH PRESSURE MOVES
OVERHEAD...WINDS AND GUSTS WILL DIMINISH...KEEPING SUSTAINED WINDS
LESS THAN 15 MPH AND GUSTS UNDER 20 MPH. WHILE THE FIRE WEATHER
THREAT WILL REMAIN ELEVATED...WE ARE NOT EXPECTED TO MEET WARNING
CRITERIA.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION EXPECTED THROUGH THE END OF THE WEEK. THERE
IS THE POTENTIAL FOR SIGNIFICANT RAINFALL ACROSS THE REGION FROM
THIS WEEKEND INTO EARLY NEXT WEEK.
SEVERE DROUGHT CONDITIONS HAVE DEVELOPED OVER SOUTHERN CT AND
LONG ISLAND. PLEASE REFER TO THE DROUGHT INFORMATION STATEMENT
FOR MORE INFORMATION.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MALOIT/SEARS/DW
NEAR TERM...MALOIT
SHORT TERM...SEARS
LONG TERM...DW
AVIATION...JM/MPS
MARINE...MALOIT/SEARS/DW
FIRE WEATHER...SEARS/MALOIT
HYDROLOGY...DW
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1008 AM EDT WED APR 18 2012
.SYNOPSIS...
HIGH PRESSURE ACROSS SOUTHERN CANADA TODAY WILL MOVE EASTWARD OFF
THE NEW ENGLAND COAST BY THURSDAY. MEANWHILE...A WEAK DISTURBANCE IS
THEN FORECAST TO TRACK SOUTH OF THE AREA TODAY INTO THURSDAY.
HIGH PRESSURE BUILDS BACK IN FOR THURSDAY AND THURSDAY NIGHT BEFORE
SHIFTING FARTHER TO THE EAST FRIDAY. THE NEXT COLD FRONT MOVES IN
DURING SATURDAY, HOWEVER AN AREA LOW LOW PRESSURE ALONG THIS FRONT
TRACKING TO OUR SOUTH WILL SLOWLY MOVE NORTHEASTWARD SUNDAY AND
MONDAY. THIS SYSTEM IS THEN FORECAST TO BE NEAR NEW ENGLAND TUESDAY
AS HIGH PRESSURE BUILDS TOWARD THE OHIO VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE AREA OF RAIN OVERRUNNING THE COOLER AIR NEAR THE SURFACE
CONTINUES TO MAKE PROGRESS INTO THE NORTHEAST DELAWARE AND
SOUTHERN DELAWARE. MOST OBSERVATIONS ARE SHOWING VERY LIGHT
RAIN...AND THIS MAKES SENSE CONSIDERING THAT THE 1200 UTC
SOUNDINGS SHOW DRY AIR UP THROUGH THE MID LEVELS. THE LATEST HRRR
RUN IS A BIT BEHIND REALITY THIS MORNING...BUT IS SHOWING A
NORTHEAST TREND WITH THE LIGHT RAIN.
CONSIDERING HOW DRY THE LOW LEVELS ARE...THE EXTENT AND AMOUNT OF
PRECIPITATION DEPICTED BY THE LATEST HRRR SEEMS A BIT OVERDONE.
HOWEVER...THE RADAR PRESENTATION (AND GROUND TRUTH BELOW THAT
ACROSS NORTHEAST MARYLAND) SUGGESTS THAT THE AREAL COVERAGE OF THE
RAIN NEEDED TO BE EXTENDED A BIT MORE ON THE LATEST FORECAST
UPDATE. IN ANY EVENT...THE RAINFALL SHOULD BE LIGHT (LESS THAN
0.10 INCHES ACROSS SOUTHERNMOST AREAS...AND PERHAPS NOT MUCH MORE
THAN A TRACE ACROSS SOUTH CENTRAL NEW JERSEY.
THE MID LEVEL CLOUDINESS IS NOT COMPLETELY OPAQUE (BASED ON THE
OBSERVATION HERE AT THE OFFICE)...AND THERE IS SOME SUNSHINE
ACROSS PORTIONS OF NEW JERSEY AND EASTERN PENNSYLVANIA. THIS
PROBABLY FILLS IN AS THE RAIN MOVES NORTHEAST. THE CLOUD COVER
SHOULD KEEP TEMPERATURES DOWN...ESPECIALLY ACROSS SOUTHERN AREAS.
THE 1200 UTC SOUNDINGS SHOW FULL SUN TEMPERATURES IN THE MID
60S...AND BASED ON CURRENT HOURLY TEMPERATURES...THAT APPEARS TOO
HIGH. ACCORDINGLY...HIGH TEMPERATURES WERE TRIMMED A BIT MORE
ACROSS SOUTHERN AREAS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
AN IMPULSE IN THE WESTERLY MID LEVEL FLOW IS FORECAST TO PASS
OVERHEAD THIS EVENING, WITH A MORE SUBSTANTIAL MID LEVEL SHORT WAVE
EXPECTED TO MOVE OFF THE MIDDLE ATLANTIC COAST OVERNIGHT. IT SHOULD
REMAIN MOSTLY CLOUDY IN OUR REGION TONIGHT WITH A CONTINUED CHANCE
OR SLIGHT CHANCE OF LIGHT SHOWERS, MAINLY IN OUR SOUTHERN COUNTIES.
THE WIND IS EXPECTED TO BE MOSTLY LIGHT AND VARIABLE, AND
TEMPERATURES SHOULD FALL INTO THE 40S AT MOST LOCATIONS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE BEGINNING OF THE LONG TERM IS DRY AS HIGH PRESSURE BUILDS BACK
ACROSS THE AREA. A FEW LINGERING CLOUDS WILL BE ACROSS ERN NJ AND
THE DELMARVA THU MORNING ASSOCIATED WITH THE DEPARTING WEAK LOW
FROM THE SHORT TERM...NO RAINFALL IS EXPECTED HOWEVER. IT WILL BE
SEASONABLY MILD ACROSS THE AREA THU WITH HIGHS IN THE MID TO UPPER
60S. THE DRY WEATHER WILL CARRY INTO FRI WITH EVEN MILDER
TEMPERATURES. HIGHS ON FRI WILL BE IN THE LOW TO MID 70S.
UNSETTLED WEATHER WILL BE ACROSS THE AREA FRI NIGHT INTO THE
WEEKEND. THE NEXT SYSTEM DOES APPEAR TO BE TRENDING A BIT SLOWER. I
KEPT THE SLGT CHC POPS IN FOR FRI NIGHT...ONLY TO MAINTAIN THE SENSE
OF CONTINUITY ACROSS THE CWA`S. IT WILL PROBABLY END UP BEING DRY
FRI NIGHT. THE STEADIER RAIN WILL PROBABLY ARRIVE LATER SAT WITH CHC
POPS IN THE GRIDS FOR THE AFTERNOON. AGAIN THE TREND TOWARD A LOWER
POPS OR A DRY FCST FOR SAT COULD STILL HAPPEN. THE EC/GFS SHOW THE
BULK OF THE RAIN FOR SAT NIGHT INTO MON WITH THE POTENTIAL FOR A
SOAKING RAIN DURING THE PERIOD. TOTAL QPF ENDING 12Z COULD BE 2 TO 3
INCHES NORTH/WEST AND CENTRAL AREAS WITH 1 TO 2 INCHES DELMARVA AND
ERN NJ. IT APPEARS THE RAINS WILL COME IN A LONG ENOUGH STRETCH TO
PRECLUDE ANY FLOODING PROBLEMS HOWEVER. HIGHS SUN AND MON WILL
MOSTLY BE IN THE UPPER 50S TO LOW 60S WITH THE CLOUDS AND RAIN.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. ISOLATED TO
SCATTERED LIGHT RAIN SHOWERS ARE POSSIBLE, ESPECIALLY AROUND KILG,
KMIV AND KACY FROM THIS AFTERNOON INTO TONIGHT. HOWEVER, THE RAIN
SHOWERS SHOULD HAVE LITTLE IMPACT AT THE TAF SITES.
A NORTH WIND AROUND 6 TO 10 KNOTS THIS MORNING IS EXPECTED TO BECOME
VARIABLE FOR THIS AFTERNOON AT 6 KNOTS OR LESS. WITH HIGH PRESSURE
NOSING INTO OUR REGION FROM THE NORTH, A LIGHT WIND IS ANTICIPATED
FOR TONIGHT, AS WELL.
OUTLOOK...
THU THRU FRI NIGHT...MOSTLY VFR.
SAT THRU SUNDAY...DETERIORATING CIGS/VSBYS WITH SHOWERS. LOW/MVFR
OR IFR POSSIBLE BY SUN.
&&
.MARINE...
A SECONDARY COLD FRONT DROPPED THROUGH OUR REGION DURING THE NIGHT.
A NORTH WIND AROUND 10 TO 15 KNOTS IS ANTICIPATED FOR THIS MORNING.
THE WIND SHOULD VEER TOWARD THE EAST THIS AFTERNOON WITH SPEEDS
DECREASING TO 5 TO 10 KNOTS FOR TONIGHT AS HIGH PRESSURE NOSES INTO
OUR REGION FROM THE NORTH. THE WIND DIRECTION MAY BECOME VARIABLE ON
OUR NORTHERN WATERS AT THAT TIME.
WAVE HEIGHTS ON OUR OCEAN WATERS SHOULD REMAIN AROUND 2 TO 3 FEET.
ON DELAWARE BAY, WAVE HEIGHTS SHOULD BE 2 FEET OR LESS FOR TODAY AND
TONIGHT.
OUTLOOK...
SUB-SCA CONDITIONS EXPECTED THU THRU SAT MORNING WITH WEAK HIGH
PRESSURE ACROSS THE WATERS. AN APPROACHING LOW/FRONT WILL CAUSE
INCREASING WINDS/SEAS LATER SAT WHICH COULD BRING SCA CONDITIONS.
ANY SCA CONDITIONS COULD LAST INTO SUN WITH THE SYSTEM MOVING
RATHER SLOWLY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...HAYES
SHORT TERM...IOVINO
LONG TERM...O`HARA
AVIATION...IOVINO
MARINE...IOVINO
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
840 AM EDT WED APR 18 2012
.SYNOPSIS...
HIGH PRESSURE ACROSS SOUTHERN CANADA TODAY WILL MOVE EASTWARD OFF
THE NEW ENGLAND COAST BY THURSDAY. MEANWHILE...A WEAK DISTURBANCE IS
THEN FORECAST TO TRACK SOUTH OF THE AREA TODAY INTO THURSDAY.
HIGH PRESSURE BUILDS BACK IN FOR THURSDAY AND THURSDAY NIGHT BEFORE
SHIFTING FARTHER TO THE EAST FRIDAY. THE NEXT COLD FRONT MOVES IN
DURING SATURDAY, HOWEVER AN AREA LOW LOW PRESSURE ALONG THIS FRONT
TRACKING TO OUR SOUTH WILL SLOWLY MOVE NORTHEASTWARD SUNDAY AND
MONDAY. THIS SYSTEM IS THEN FORECAST TO BE NEAR NEW ENGLAND TUESDAY
AS HIGH PRESSURE BUILDS TOWARD THE OHIO VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DESPITE THE DRY LOW LEVELS DEPICTED ON THE 18/1200 UTC KAPG
SOUNDING...RAIN IS PROGRESSING INTO PORTIONS OF NORTHEAST MARYLAND
AND SOON SOUTHERN DELAWARE. MOISTURE IS OVERRUNNING THE COOL
AIRMASS NEAR THE SURFACE...ALLOWING THE RAIN TO SPREAD NORTHEAST
AHEAD OF THE SHORT WAVE OVER THE LOWER OHIO VALLEY.
EXTRAPOLATION OF THE AREA OF RAIN (WHICH IS SUPPORTED BY THE
LATEST HRRR PRECIPITATION FIELDS) BRINGS IT INTO NORTHEAST
MARYLAND AND MUCH OF DELAWARE...AND THE CHANCE OF RAIN WAS
INCREASED IN THESE AREAS FOR THIS MORNING AND EARLY THIS AFTERNOON.
THE AREAL EXTENT OF THE RAIN WAS ALSO INCREASED TO INCLUDE MORE OF
SOUTHEAST PENNSYLVANIA AND SOUTHERN NEW JERSEY...AGAIN BASED ON
THE HRRR PRECIPITATION FIELDS.
THE MID CLOUDS HAVE ALREADY SLOWED THE RISE IN TEMPERATURES THIS
MORNING. FORECAST HIGHS HAVE BEEN DROPPED A BIT TO ACCOUNT FOR THE
MID LEVEL CLOUDINESS...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE
AREA...AND MAY NOT BE ENOUGH BASED ON TRENDS. ALSO...HOURLY
TEMPERATURES WERE DROPPED A BIT IN DEFERENCE TO THE CLOUDINESS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
AN IMPULSE IN THE WESTERLY MID LEVEL FLOW IS FORECAST TO PASS
OVERHEAD THIS EVENING, WITH A MORE SUBSTANTIAL MID LEVEL SHORT WAVE
EXPECTED TO MOVE OFF THE MIDDLE ATLANTIC COAST OVERNIGHT. IT SHOULD
REMAIN MOSTLY CLOUDY IN OUR REGION TONIGHT WITH A CONTINUED CHANCE
OR SLIGHT CHANCE OF LIGHT SHOWERS, MAINLY IN OUR SOUTHERN COUNTIES.
THE WIND IS EXPECTED TO BE MOSTLY LIGHT AND VARIABLE, AND
TEMPERATURES SHOULD FALL INTO THE 40S AT MOST LOCATIONS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE BEGINNING OF THE LONG TERM IS DRY AS HIGH PRESSURE BUILDS BACK
ACROSS THE AREA. A FEW LINGERING CLOUDS WILL BE ACROSS ERN NJ AND
THE DELMARVA THU MORNING ASSOCIATED WITH THE DEPARTING WEAK LOW
FROM THE SHORT TERM...NO RAINFALL IS EXPECTED HOWEVER. IT WILL BE
SEASONABLY MILD ACROSS THE AREA THU WITH HIGHS IN THE MID TO UPPER
60S. THE DRY WEATHER WILL CARRY INTO FRI WITH EVEN MILDER
TEMPERATURES. HIGHS ON FRI WILL BE IN THE LOW TO MID 70S.
UNSETTLED WEATHER WILL BE ACROSS THE AREA FRI NIGHT INTO THE
WEEKEND. THE NEXT SYSTEM DOES APPEAR TO BE TRENDING A BIT SLOWER. I
KEPT THE SLGT CHC POPS IN FOR FRI NIGHT...ONLY TO MAINTAIN THE SENSE
OF CONTINUITY ACROSS THE CWA`S. IT WILL PROBABLY END UP BEING DRY
FRI NIGHT. THE STEADIER RAIN WILL PROBABLY ARRIVE LATER SAT WITH CHC
POPS IN THE GRIDS FOR THE AFTERNOON. AGAIN THE TREND TOWARD A LOWER
POPS OR A DRY FCST FOR SAT COULD STILL HAPPEN. THE EC/GFS SHOW THE
BULK OF THE RAIN FOR SAT NIGHT INTO MON WITH THE POTENTIAL FOR A
SOAKING RAIN DURING THE PERIOD. TOTAL QPF ENDING 12Z COULD BE 2 TO 3
INCHES NORTH/WEST AND CENTRAL AREAS WITH 1 TO 2 INCHES DELMARVA AND
ERN NJ. IT APPEARS THE RAINS WILL COME IN A LONG ENOUGH STRETCH TO
PRECLUDE ANY FLOODING PROBLEMS HOWEVER. HIGHS SUN AND MON WILL
MOSTLY BE IN THE UPPER 50S TO LOW 60S WITH THE CLOUDS AND RAIN.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. ISOLATED TO
SCATTERED LIGHT RAIN SHOWERS ARE POSSIBLE, ESPECIALLY AROUND KILG,
KMIV AND KACY FROM THIS AFTERNOON INTO TONIGHT. HOWEVER, THE RAIN
SHOWERS SHOULD HAVE LITTLE IMPACT AT THE TAF SITES.
A NORTH WIND AROUND 6 TO 10 KNOTS THIS MORNING IS EXPECTED TO BECOME
VARIABLE FOR THIS AFTERNOON AT 6 KNOTS OR LESS. WITH HIGH PRESSURE
NOSING INTO OUR REGION FROM THE NORTH, A LIGHT WIND IS ANTICIPATED
FOR TONIGHT, AS WELL.
OUTLOOK...
THU THRU FRI NIGHT...MOSTLY VFR.
SAT THRU SUNDAY...DETERIORATING CIGS/VSBYS WITH SHOWERS. LOW/MVFR
OR IFR POSSIBLE BY SUN.
&&
.MARINE...
A SECONDARY COLD FRONT DROPPED THROUGH OUR REGION DURING THE NIGHT.
A NORTH WIND AROUND 10 TO 15 KNOTS IS ANTICIPATED FOR THIS MORNING.
THE WIND SHOULD VEER TOWARD THE EAST THIS AFTERNOON WITH SPEEDS
DECREASING TO 5 TO 10 KNOTS FOR TONIGHT AS HIGH PRESSURE NOSES INTO
OUR REGION FROM THE NORTH. THE WIND DIRECTION MAY BECOME VARIABLE ON
OUR NORTHERN WATERS AT THAT TIME.
WAVE HEIGHTS ON OUR OCEAN WATERS SHOULD REMAIN AROUND 2 TO 3 FEET.
ON DELAWARE BAY, WAVE HEIGHTS SHOULD BE 2 FEET OR LESS FOR TODAY AND
TONIGHT.
OUTLOOK...
SUB-SCA CONDITIONS EXPECTED THU THRU SAT MORNING WITH WEAK HIGH
PRESSURE ACROSS THE WATERS. AN APPROACHING LOW/FRONT WILL CAUSE
INCREASING WINDS/SEAS LATER SAT WHICH COULD BRING SCA CONDITIONS.
ANY SCA CONDITIONS COULD LAST INTO SUN WITH THE SYSTEM MOVING
RATHER SLOWLY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...IOVINO/HAYES
SHORT TERM...IOVINO
LONG TERM...O`HARA
AVIATION...IOVINO
MARINE...IOVINO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1003 AM CDT WED APR 18 2012
.DISCUSSION...
ISSUED 1003 AM CDT WED APR 18 2012
BAND OF RAIN SHOWERS ACROSS EASTERN IOWA HAS BEEN BREAKING UP THE
LAST FEW HOURS...WITH MAINLY THE ASSOCIATED ALTOCUMULUS CLOUDS
STILL EXPECTED TO AFFECT THE NORTHERN CWA LATER TODAY. LATEST NAM
AND HRRR MODELS HOLD ON TO ENOUGH OF THE PRECIPITATION TO JUSTIFY
HOLDING ONTO THE EXISTING 20 PERCENT RAIN CHANCES ACROSS THE FAR
NORTH THIS AFTERNOON. HAVE SENT SOME MINOR TWEAKS TO THE HOURLY
TEMPERATURE/SKY GRIDS...BUT NO CHANGE IS NEEDED TO THE WORDED
FORECASTS AT THIS TIME.
GEELHART
&&
.AVIATION...
ISSUED 605 AM CDT WED APR 18 2012
VFR CONDITIONS ARE EXPECTED THROUGH THIS FORECAST PERIOD. A COLD
FRONT TO OUR NORTHWEST WILL SLOWLY APPROACH THE AREA LATE TODAY.
OTHER THAN SOME SCATTERED CU AND MID LEVEL CLOUDS...NOT MUCH IN
THE WAY OF SENSIBLE WEATHER IS EXPECTED ACROSS THE TAF SITES TODAY.
SOME ISOLD CONVECTION WILL BE POSSIBLE NORTH OF PIA AND BMI LATE
TODAY AND TONIGHT BUT WITH THE FRONT EXPECTED TO STALL OUT NORTH
OF OUR AREA LATER IN THE FORECAST PERIOD...RAIN CHANCES WILL REMAIN
NORTH OF THE TAF SITES THRU 12Z THURSDAY. SURFACE WINDS WILL
INCREASE OUT OF THE SOUTH TO SOUTHWEST AT 12 TO 17 KTS WITH A FEW
GUSTS ARND 25 KTS AT TIMES...ESPECIALLY ALONG AND WEST OF A BMI TO
SPI LINE THIS AFTN. WINDS WILL DIMINISH SOME OUT OF THE SOUTH
TONIGHT WITH NO MORE THAN SOME SCT-BKN CIGS AT 8000-10000 FEET...
MAINLY ACROSS THE NORTH.
SMITH
&&
.PREV DISCUSSION...
ISSUED 252 AM CDT WED APR 18 2012
SHORT TERM...TODAY THROUGH FRIDAY
LOW PRESSURE ANALYZED OVER WESTERN MINNESOTA AT 06Z WILL TRACK
NORTHEASTWARD TODAY...REACHING LAKE SUPERIOR BY LATE THIS
AFTERNOON. TRAILING COLD FRONT WILL GRADUALLY SETTLE SOUTHWARD
TOWARD ILLINOIS...WITH HIGH-RES MODELS SUGGESTING WIDELY SCATTERED
SHOWERS/STORMS DEVELOPING ALONG IT AFTER 21Z. WITH BOUNDARY
EXPECTED TO REMAIN WELL TO THE NORTH...HAVE ONLY INCLUDED A SLIGHT
CHANCE POP ACROSS THE FAR NORTHERN KILX CWA AROUND GALESBURG.
FURTHER SOUTH ACROSS THE REMAINDER OF THE AREA...EXPECT MOSTLY
SUNNY AND DRY CONDITIONS. AS PRESSURE GRADIENT TIGHTENS BETWEEN
HIGH ANCHORED OVER THE OHIO RIVER VALLEY AND APPROACHING COLD
FRONT...GUSTY S/SW WINDS WILL DEVELOP THIS AFTERNOON. FORECAST
SOUNDINGS AND NUMERIC GUIDANCE INDICATE GUSTS UP TO 25
MPH...PARTICULARLY ALONG/WEST OF THE I-55 CORRIDOR.
FRONT WILL STALL ACROSS NORTHERN ILLINOIS TONIGHT INTO THURSDAY...AS
IT BECOMES PARALLEL TO THE ZONAL UPPER FLOW. AS SUCH...BEST
FORCING FOR SHOWERS/STORMS WILL REMAIN TO THE NORTH OF CENTRAL
ILLINOIS ACROSS IOWA INTO NORTHERN ILLINOIS. HAVE MAINTAINED LOW
CHANCE POPS IN CLOSER PROXIMITY TO THE BOUNDARY FROM PEORIA
NORTHWARD...BUT HAVE GONE WITH A DRY FORECAST FURTHER SOUTH ACROSS
THE REST OF THE AREA. PARTIAL SUNSHINE AND A CONTINUED STRONG
SOUTHERLY FLOW WILL HELP PUSH HIGH TEMPERATURES WELL INTO THE 70S
ON THURSDAY.
MODELS CONTINUE TO SHOW SHORT-WAVE CROSSING THE ROCKIES AND SLOWLY
AMPLIFYING OVER THE MISSISSIPPI RIVER VALLEY TOWARD THE END OF
THE WEEK...GRADUALLY PUSHING THE STALLED FRONTAL BOUNDARY FURTHER
SOUTH AND EAST. THE GENERAL TREND OVER THE PAST SEVERAL MODEL RUNS
HAS BEEN TO SLOW DOWN THIS PROCESS AS UPPER WAVE DIGS INTO THE
DEEP SOUTH AND CUTS OFF ALONG THE GULF COAST. 00Z 18 APR SUITE HAS
CONTINUED THE SLOWING TREND...NOW FEATURING FRONT REMAINING IN THE
VICINITY AT LEAST THROUGH FRIDAY NIGHT AND PERHAPS INTO SATURDAY
MORNING ACROSS THE SOUTHEAST CWA. HAVE ADJUSTED POPS
ACCORDINGLY...FOCUSING HIGHEST RAIN CHANCES ACROSS THE ILLINOIS
RIVER VALLEY THURSDAY NIGHT...THEN EVERYWHERE FRIDAY/FRIDAY NIGHT.
LONG TERM...SATURDAY THROUGH TUESDAY
DUE TO THE SLOWER DEPARTURE OF THE FRONT...HAVE HELD ON TO LOW
CHANCE POPS ALONG/SOUTH OF I-70 INTO SATURDAY. ELSEWHERE AROUND
THE AREA...DRY AND MUCH COOLER WEATHER WILL BE ON TAP AS
NORTHWESTERLY FLOW PATTERN DEVELOPS ACROSS THE MIDWEST. WITH 850MB
TEMPS DROPPING INTO THE 0 TO 5C RANGE...HIGH TEMPS WILL ONLY REACH
THE 50S ON BOTH SATURDAY AND SUNDAY...WITH OVERNIGHT LOWS DIPPING
INTO THE 30S. FURTHER OUT...MODEL DISCREPANCIES CONCERNING THE
EVOLUTION OF THE EASTERN CONUS TROUGH PERSIST...HOWEVER GENERAL
CONSENSUS POINTS TO A CONTINUED COOL NORTHWESTERLY FLOW ACROSS
ILLINOIS THROUGH AT LEAST EARLY NEXT WEEK.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1052 AM EDT WED APR 18 2012
.SYNOPSIS...
SHOWERS MOVING ACROSS THE SOUTHEAST STATES WILL EXTEND TO THE
RIDGES TODAY BEFORE HIGH PRESSURE BUILDS IN AND KEEPS CONDITIONS
DRY UNTIL FRIDAY. A SLOW MOVING COLD FRONT WILL BRING THE CHANCE
FOR SHOWERS FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER LEVEL SHORTWAVE MOVING ACROSS THE SOUTHEAST STATES WILL
CONTINUE PROVIDING SHOWERS EXTENDING INTO SOUTHERN PART OF CWA
THROUGH TONIGHT. INCREASED POPS FOR SOUTHERN COUNTIES BASED ON
LATEST HRRR AND RADAR TRENDS. CLOUD COVER WILL REMAIN THE GREATEST
IN SOUTHERN AND EASTERN CWA...KEEPING TEMPERATURES SLIGHTLY COOLER
THAN WESTERN AND NORTHERN COUNTIES.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
LOW PRESSURE OVER QUEBEC THURSDAY MORNING WILL MOVE TO THE
EAST...WITH A TRAILING COLD FRONT ACROSS THE GREAT LAKES. COLD FRONT
SHOULD REMAIN ACROSS THE EASTERN GREAT LAKES ON THURSDAY...KEEPING
DRY WEATHER LOCALLY. FRONT WILL MAKE VERY SLOW PROGRESS
FRIDAY...WITH SHOWERS FINALLY DRIFTING INLAND. 21Z SREF IS THE
OUTLIER FOR MOVING THE FRONT THROUGH FRIDAY NIGHT...AND WILL
CONTINUE TO GO WITH SLOWER GFS/ECMWF SOLUTIONS. RAIN SHOULD FINALLY
MOVE IN FOR SATURDAY. WITH SOUTHWESTERLY FLOW...TEMPERATURES WILL BE
ON THE INCREASE THURSDAY AND FRIDAY...RISING TO 10 AND THEN 15
DEGREES ABOVE NORMAL. FRONTAL TIMING WILL BE THE KEY TO HIGH
TEMPERATURES ON SATURDAY...AND FOR NOW HAVE DROPPED TEMPERATURES
BACK TO NEAR NORMAL LEVELS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
PRECIPITATION WILL TAPER TO SCATTERED COVERAGE AS COLD FRONT MOVES
EAST SATURDAY NIGHT. MODELS SHOW A CLOSED UPPER LOW FORMING AT
THE BOTTOM OF A SHARP TROUGH AND RIDING EAST ALONG THE GULF COAST
SATURDAY AND SUNDAY. LATEST MODEL RUNS STILL DIFFER ON THE TRACK
OF A SURFACE LOW MOVING ALONG THE EASTERN SEABOARD AND THE WESTERN
EXTENT OF PRECIPITATION MONDAY AND TUESDAY. FORECAST POPS ARE
CLOSE TO HPC NUMBERS WITH HIGH END CHANCE POPS SUNDAY TAPERING TO
AROUND 30 PERCENT ALONG THE RIDGES AND SLIGHT CHANCE FURTHER WEST
BY MONDAY MORNING.
TEMPERATURES ARE FORECAST TO COOL TO BETWEEN 5 AND 10 DEGREES BELOW
NORMAL BY EARLY NEXT WEEK.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
EXPECT VFR TO CONTINUE ACROSS THE UPPER OHIO VALLEY THROUGH
TONIGHT AS RAIN WITH A MID-LEVEL DISTURBANCE PASSES JUST SOUTHEAST OF
THE AREA. THERE IS A CHANCE OF A BRIEF VFR SHOWER AT KMGW, ALTHOUGH
CONFIDENCE IN NORTHERN PROGRESSION OF PRECIP IS TOO LOW TO MENTION
IN THE TAF AT THIS TIME. WINDS WILL BE FROM THE NORTHEAST AND EAST
AT 4-8 KTS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
EXPECT VFR THURSDAY AND FRIDAY. RESTRICTIONS WILL BECOME LIKELY
FRIDAY NIGHT INTO SUNDAY DUE TO SHOWERS ASSOCIATED WITH THE SLOW
PASSAGE OF AN EASTBOUND LOW PRESSURE SYSTEM.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
746 AM EDT WED APR 18 2012
.SYNOPSIS...
CONDITIONS ARE EXPECTED TO BE DRY INTO FRIDAY...EXCEPT FOR THE
CHANCE OF LIGHT RAIN IN THE RIDGES TODAY. A WEEKEND COLD FRONT
SHOULD BRING THE NEXT CHANCE FOR WIDESPREAD RAIN.
&&
.NEAR TERM /THROUGH TONIGHT/...
745AM UPDATE...UPDATED PROBABILITY OF PRECIPITATION AND WEATHER TYPE
GRIDS TO REFLECT CURRENT RADAR. PRECIPITATION TRACKING JUST A BIT
FARTHER NORTH THAN GUIDANCE. REMAINDER UNCHANGED.
PREVIOUS DISCUSSION...
ALL MODELS ARE IN GOOD AGREEMENT SHOWING THE PASSAGE OF AN UPPER
LEVEL SHORTWAVE MOVING ACROSS THE MID-ATLANTIC STATES TODAY AND
TONIGHT. SYNOPTIC/HI-RES MODELS ALSO SHOW SIMILAR DEPICTIONS OF
TIGHT PRECIPITATION GRADIENT FALLING JUST EAST OF THE FORECAST AREA.
HOWEVER...COMPARING MODEL FORECASTS AT 06Z TO RADAR SHOWS THAT ALL
MODELS EXCEPT FOR THE HRRR HAVE NOT TRENDED PRECIP FAR ENOUGH TO THE
NORTH AND WEST. THEREFORE...HAVE MOVED MORE IN THE DIRECTION OF THE
21Z SREF AND 03Z HRRR...BRINGING POPS FARTHER INTO
FAYETTE...MARION...AND MONONGALIA COUNTIES. LATER FORECASTS MAY NEED
TO BRING RAIN FARTHER TO THE NORTH AND WEST. CLOUD SHIELD WILL
EXTEND EVEN FARTHER TO THE NORTH AND WEST...WITH ALL LOCATIONS
EXPECTING PARTLY CLOUDY SKIES IN THE MORNING AND INCREASING SUN
OUTSIDE OF THE RIDGES IN THE AFTERNOON. RAIN COULD POTENTIALLY HOLD
ON INTO THE EVENING HOURS IN THE RIDGES...BUT WILL DRY OUT FOR THE
OVERNIGHT HOURS. TEMPERATURES SHOULD BE FAIRLY CLOSE TO YESTERDAYS
VALUES.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
LOW PRESSURE OVER QUEBEC THURSDAY MORNING WILL MOVE TO THE
EAST...WITH A TRAILING COLD FRONT ACROSS THE GREAT LAKES. COLD FRONT
SHOULD REMAIN ACROSS THE EASTERN GREAT LAKES ON THURSDAY...KEEPING
DRY WEATHER LOCALLY. FRONT WILL MAKE VERY SLOW PROGRESS
FRIDAY...WITH SHOWERS FINALLY DRIFTING INLAND. 21Z SREF IS THE
OUTLIER FOR MOVING THE FRONT THROUGH FRIDAY NIGHT...AND WILL
CONTINUE TO GO WITH SLOWER GFS/ECMWF SOLUTIONS. RAIN SHOULD FINALLY
MOVE IN FOR SATURDAY. WITH SOUTHWESTERLY FLOW...TEMPERATURES WILL BE
ON THE INCREASE THURSDAY AND FRIDAY...RISING TO 10 AND THEN 15
DEGREES ABOVE NORMAL. FRONTAL TIMING WILL BE THE KEY TO HIGH
TEMPERATURES ON SATURDAY...AND FOR NOW HAVE DROPPED TEMPERATURES
BACK TO NEAR NORMAL LEVELS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
PRECIPITATION WILL TAPER TO SCATTERED COVERAGE AS COLD FRONT MOVES
EAST SATURDAY NIGHT. MODELS SHOW A CLOSED UPPER LOW FORMING AT
THE BOTTOM OF A SHARP TROUGH AND RIDING EAST ALONG THE GULF COAST
SATURDAY AND SUNDAY. LATEST MODEL RUNS STILL DIFFER ON THE TRACK
OF A SURFACE LOW MOVING ALONG THE EASTERN SEABOARD AND THE WESTERN
EXTENT OF PRECIPITATION MONDAY AND TUESDAY. FORECAST POPS ARE
CLOSE TO HPC NUMBERS WITH HIGH END CHANCE POPS SUNDAY TAPERING TO
AROUND 30 PERCENT ALONG THE RIDGES AND SLIGHT CHANCE FURTHER WEST
BY MONDAY MORNING.
TEMPERATURES ARE FORECAST TO COOL TO BETWEEN 5 AND 10 DEGREES BELOW
NORMAL BY EARLY NEXT WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
EXPECT VFR TO CONTINUE ACROSS THE UPPER OHIO VALLEY THROUGH
TONIGHT, WITH LITTLE MORE THAN BANDS OF ALTOCUMULUS. SURFACE WINDS
WILL BE FROM THE NORTHEAST AND EAST AT 4-8 KTS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
EXPECT VFR THURSDAY AND FRIDAY. RESTRICTIONS WILL BECOME LIKELY
FRIDAY NIGHT INTO SUNDAY DUE TO SHOWERS ASSOCIATED WITH THE SLOW
PASSAGE OF AN EASTBOUND LOW PRESSURE SYSTEM.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GLASGOW MT
940 AM MDT WED APR 18 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH FRIDAY...
UPDATED THE FORECAST TO INCREASE POPS ACROSS THE WESTERN ZONES FOR
THIS MORNING AND TO LOWER THE OVER ALL HIGH TEMPERATURES. MADE A
FEW CALLS TO SPOTTERS AND COULD ONLY FIND VERY LIGHT RAIN TO
SPRINKLES. RAISED THE POPS UP TO AROUND 80 TO 90 PERCENT FOR THIS
MORNING AND LEFT IT AROUND 50 PERCENT FOR THIS AFTERNOON. THE HIGH
POPS FOR THIS MORNING ARE BASICALLY SAYING A VERY HIGH CHANCE OF
SPRINKLES TO MAYBE A FEW HUNDREDTHS OF AN INCH IF YOU ARE LUCKY.
SINCE WE HAVE THICKER CLOUD COVER AND THE ONSET OF PRECIPITATION
DECIDED TO LOWER THE TEMPERATURES THIS MORNING BY ALMOST 10
DEGREES ACROSS THE NORTHERN ZONES. CURRENT READING ARE STILL IN
THE UPPER 30S TO LOWER 40S ACROSS EASTERN MONTANA. EXPECT HIGHS TO
RANGE FROM THE MID 40S NORTH TO THE MID 50S ACROSS THE YELLOWSTONE
VALLEY. REST OF THE SHORT TERM FORECAST LOOKS GOOD. RSMITH
PREVIOUS DISCUSSION...THE SHORT TERM FORECAST IS A HARD ONE
TODAY FOR NORTHEAST MONTANA... MANY VARIABLES PLAYING INTO THE
FORECAST EQUATION FOR THE NEXT 48 HOURS.
FOR THE FIRST 12 HOUR TOOK THE HRRR FOR THE POPS/QPF FORECAST. IT
HAS PREFORMED VERY WELL THIS SPRING SEASON. PLUS THE GFS/NAM AGAIN
ARE BRINGING HIGH QPF VALUES TO NORTHEAST MONTANA. THE MODELS HAVE
A POOR TRACK RECORD IN THE PAST MONTH WITH FORECASTING QPF OVER
NORTHEAST MONTANA WITH A TREMENDOUS WET BIAS. MODEL SOUNDINGS SHOW
AT THE GGW POINT ...ALONG WITH BUFR SOUNDINGS... A SLOW MOISTENING
OF THE DRY LOW LEVELS THROUGH THE AFTERNOON HOURS. SPLIT THE
WEATHER GRIDS FOR THE FIRST 12 HOURS INTO 3 HOUR BLOCKS. DID THIS
TO SHOW THE STUBBORNLY SLOW PROGRESS OF MEASURABLE PRECIPITATION
ACROSS THE REGION. DO EXPECT LOTS OF VIRGA AND GUSTY WINDS THIS
AFTERNOON AS THE ATMOSPHERE MOISTENS UP. DECIDED TO FLY THE LAKE
WIND ADVISORY WITH THE MARGINAL 15 TO 25 MPH WINDS DUE TO THE GUST
FACTOR THAT COULD SURPRISE IN EXPERIENCED BOATERS EARLY IN THE
SEASON.
TONIGHT WENT WITH HIGH POP LOW QPF/LITTLE OR CHANCE OF WETTING
RAIN SOLUTION. CONFIDENCE IS MODERATE... MODELS ALL ARE GOING FOR
A WETTING RAIN ACROSS MOST OF NORTHEAST MONTANA. HOWEVER THE MODEL
PERFORMANCE ON RAINFALL HAS BEEN POOR AND OVER FORECASTING
RAINFALL.
ON THURSDAY AS THE WINDS SWITCH TO THE WEST ACROSS THE AREA CLOUD
BASES WILL RISE AND AGAIN THE BOUNDARY LAYER SHOULD DRY OUT
KEEPING MEASURABLE PRECIPITATION VALUES LOW. THE ONE ISSUE THAT
COULD INCREASE POPS THURSDAY AFTERNOON IS VERY STEEP LAPSE RATES
WHICH COULD SPARK A THUNDERSTORM AND CREATE SMALL AREAS OF HIGHER
RAINFALL.
THURSDAY NIGHT THE DAKOTA LOW WILL CONTINUE TO DRIFT EAST KEEPING
MOST AREAS DRY. ON FRIDAY A LOW MOVES OFF THE ALBERTA ROCKIES AND
SLIDES ACROSS SASKATCHEWAN INTO NORTH DAKOTA IN THE NORTHWEST FLOW
AHEAD OF THE BUILDING RIDGE. THIS MIGHT BRING ANOTHER VERY SLIGHT
CHANCE OF WETTING RAINS WITH STRONGER SHOWERS ACROSS THE NORTHERN
TIER OF ZONES. OTHERWISE MORE DUST SETTLING SHOWERS WITH LITTLE
RAIN RELIEF EXPECTED. PROTON
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
THE LAST IN A SERIES OF SEVERAL SHORTWAVE DISTURBANCES FROM THE W
MOVES OUT OF THE AREA FRI NIGHT. THEN A BUILDING UPPER RIDGE FROM
THE S OVER THE WEEKEND BRINGS SUNNY AND WARMER WEATHER. THE RIDGE
BECOMES QUITE STRONG WITH 850 MB TEMPS TO AS HIGH AS 18-24C
MONDAY. THICKNESSES VALUES REACH 570 DM. THIS SHOULD DRIVE NE MT
HIGHS INTO THE UPPER 70S TO MID 80S...WHICH WILL APPROACH RECORD
HIGHS FOR THE DATE AT SOME LOCATIONS.
MODELS AGREE WITH A MOSTLY DRY...BUT FAIRLY STRONG COLD FRONT FROM THE
WNW MOVING ACROSS THE AREA TUE...WHICH WILL START A COOLING TREND.
THE ASSOCIATED UPPER TROUGH LAGS BEHIND...AND MODELS HAVE VARIED
ON TIMING...INTENSITY...AND MOVEMENT WITH THIS. ECMWF HAS BEEN
TOO QUICK TO BREAK DOWN THE RIDGE. MEANWHILE CMC GEM DEFLECTS BOTH
COLD FRONT AND TROUGH TO OUR N AND KEEPS THE RIDGE OVER OUR AREA...WHICH
DOES APPEAR POSSIBLE. GFS ENSEMBLES INDICATE THAT ANY OF THESE AND
OTHER SOLUTIONS ARE POSSIBLE TOO...SO LOW CONFIDENCE AT THE END OF
THE PERIOD. PREFER THE 00Z OPERATIONAL GFS THOUGH WHICH IS MORE
OF A MIDDLE GROUND SOLUTION...AND DOES BRING AT LEAST A SLIGHT
CHANCE OF SHOWERS BY WED. SIMONSEN
&&
.AVIATION...
A MID-MORNING MVFR FOG BANK AND LOW CEILING WILL PERSIST UNTIL
ABOUT 15Z OR 16Z FOR KOLF AND KSDY. AFTER WHICH...VFR CONDITIONS
WILL THEN RETURN TODAY FOR ALL TAF SITES ACROSS NORTHEAST MONTANA
AS PERIODS OF RAIN PUSH IN FROM THE WEST AND SOUTHWEST. AFTERNOON
WINDS FROM THE EAST WILL INCREASE INTO THE 15G25KT RANGE. LATE
THIS AFTERNOON AND TONIGHT...CEILINGS LOWER TO 4K FT AGL WITH
SCATTERED SHOWERS. EXPECT A STRATIFORM RAIN TO PERSIST THROUGH THE
END OF THIS TAF PERIOD WITH OCCASIONAL MVFR CONDITIONS. BMICKELSON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR FORT PECK
LAKE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
622 AM CDT WED APR 18 2012
.AVIATION...
12Z TAFS FOR KOFK...KLNK AND KOMA.
VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE TAF PERIOD.
SCATTERED SHOWERS EARLY WILL MOVE EAST OF KOMA AND KLNK...WITH
SCATTERED CLOUDS OR CLEAR SKIES TO FOLLOW. WINDS WILL AVERAGE
SOUTH OR SOUTHWEST AT KLNK AND KOMA...AND NORTH AT KOFK...BUT
SPEEDS SHOULD REMAIN AT OR BELOW 12KTS. A LOW PRESSURE SYSTEM
MOVING INTO THE REGION OVERNIGHT WILL BRING THE CHANCE FOR SHOWERS
AND THUNDERSTORMS TO ALL TAF SITES AFTER 06Z. COVERAGE IS STILL A
QUESTION...SO 12Z TAFS WILL REFLECT ONLY SHOWERS AND VFR CIGS.
DERGAN
&&
.PREV DISCUSSION... /ISSUED 302 AM CDT WED APR 18 2012/
DISCUSSION...
MAIN FORECAST CONCERN WILL BE POPS IN THE NEAR TERM AS QUIET AND
WARMER WEATHER IS EXPECTED FOR THE WEEKEND INTO EARLY NEXT WEEK.
LATEST REGIONAL RADAR IMAGERY SHOWED BAND OF SHOWERS AND
THUNDERSTORMS PROGRESSING SOUTHEAST ACROSS THE NORTHERN PORTION
OF THE CWA. ACTIVITY IS ALONG A WEAK COLD FRONT OUT AHEAD OF A MID
LEVEL SHORTWAVE MOVING EWD THRU THE CENTRAL DAKOTAS. LATEST
SEVERAL RUNS OF THE HRRR HAVE HAD A GOOD HANDLE ON THIS LINE AND
EXPECT THE ACTIVITY TO EXIT THE SOUTHEASTERN FORECAST AREA AROUND
14Z.
WEAK FRONT WASHES OUT OVER THE AREA AND STRONG SOUTHERLY FLOW
RETURNS TONIGHT. ANOTHER WEAK SHORTWAVE WL MOVE THRU THE DAKOTAS
TONIGHT PUSHING A STRONGER COLD FRONT INTO THE FORECAST AREA
OVERNIGHT. THIS WILL BRING ANOTHER GOOD CHANCE FOR SCATTERED
SHOWERS AND THUNDERSTORMS OVERNIGHT AND INTO THURSDAY. THE FRONT
IS SLOW TO MOVE THRU AND LINGERS MUCH OF THE DAY THURSDAY UNTIL
STRONGER UPPER LEVEL SUPPORT ARRIVES THURSDAY NIGHT. CONTINUED
SMALL POPS IN OUR SOUTH LATE THURSDAY NIGHT INTO FRIDAY MORNING.
WARMING TREND ANTICIPATED FOR THE WEEKEND AND EARLY NEXT WEEK AS
AMPLIFIED UPPER RIDGE BUILDS OVER THE WESTERN CONUS. HIGHS IN THE
LOW 80S FORECAST BY TUESDAY.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
906 AM EDT WED APR 18 2012
.SYNOPSIS...
A WAVE OF LOW PRESSURE AFFECTS MAINLY EASTERN WEST VIRGINIA AND
SOUTHWEST VIRGINIA TODAY. HIGH PRESSURE THURSDAY AND FRIDAY. A STORM
SYSTEM FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
9 AM UPDATE. NOW ITS A MATTER OF WATCHING RADAR TRENDS TO SEE HOW
FAR THE NORTHERN EDGE OF THE RAIN WILL GET. HAVE ADJUSTED NORTHERN
EDGE A BIT FARTHER NORTH PER RADAR TRENDS...BUT STILL MOSTLY SOUTH
AND EAST OF HTS-CKB LINE. RAINFALL AMOUNTS WILL RANGE FROM AROUND A
HALF INCH SOUTHERN AND CENTRAL MOUNTAINS TO LESS THAN AROUND A TENTH
OF AN INCH TO NEAR THE CRW-CKB LINE...NOT MUCH WORTH NOTING NORTH OF
THERE.
UPDATED...
PUSHED POP GRADIENT A LITTLE FURTHER NW THIS MORNING. LATEST RADAR
MOSAIC AND OBS SHOW TIGHT PCPN SHIELD RUNNING ALONG 119/I79
CORRIDOR AND GENERALLY HOLDING THIS LINE. THUS HAVE USED THIS AS
ORIENTATION FOR DETERMINISTIC POPS WITH ACE ACROSS MTNS. SHOULD
SEE THIS SLOWLY PUSH OFF TO E LATER THIS MORNING...WITH MTNS
STAYING IN RA THRU AFTN.
PREVIOUS DISCUSSION BELOW...
THERE CONT TO BE SOME DISAGREEMENT WITH NW EXTENT OF MEASURABLE
PCPN THIS MORNING WITH THE NAM THE LONE GUN KEEP BULK OF QPF
ACROSS THE MTNS. MOST OTHER GUIDANCE HAS SHIFTED SOME TO NW WITH
MEASURABLE QPF...TAKING .1 TO .25 INCH CONTOUR THRU THE COAL
FIELDS TO ABOUT CRW AREA AND N UP I79 CORRIDOR. PLACEMENT OF LIFT
AND FORCING SIMILAR THOUGH. LOOKING AT MDL SOUNDINGS...ONE SEES
WHERE NAM IS HOLDING ON DRY AIR NEAR THE SFC W OF MTNS AS OTHER
MDLS INCLUDING THE RUC SATURATE THE COLUMN BY 12Z W TO CRW. LATEST
RADAR MOSAIC SHOWS SOLID AREA OF MAINLY -RA OVER SW VA AND S WV
MTNS ATTM. THIS IS TRYING TO PUSH NW SLOWLY BUT HAVING A HARD TIME
GIVEN DRY AIR IN FRONT OF IT. WILL NUDGE HIGHER POPS A HAIR NW
09-15Z THIS MORNING BUT NOT AS MUCH AS MODEL CONSENSUS SUGGESTS
WITH A BELIEF THE NAM MAY BE HANDLING THE BL MOISTURE BETTER AS
EVEN WHERE THERE IS RA OUT THERE...NOT SEEING ANY VSBY
RESTRICTIONS OR LOW CIGS CURRENTLY. WILL CONT TO MONITOR NEXT FEW
HRS FOR ANY FURTHER ADJUSTMENT TO NW.
OTHERWISE REMAINDER OF PREV FCST LOOKS GOOD. S/W TROF AXIS PUSHES
THRU THIS AFTN TAKING MUCH OF THE DEEP MOISTURE WITH IT AS SFC WAVE
PUSHES OFF TO NE. WILL GRADUALLY BRING POPS DOWN FROM W TO E THIS
AFTN...WITH AREA POP FREE BY 03Z. CONCERNING CLDS...WILL HOLD WV/SW
VA ZONES IN CLDS MUCH OF THE DAY AND ALLOW FOR SOME CLEARING ACROSS SE
OH/NE KY LATER IN AFTN. MAY SEE LOW STRATUS HOLD IN MTNS TONIGHT
WITH FG FOR ANY AREAS THAT RECEIVE RA THAT MANAGE TO CLR.
WILL LEAN TOWARD LWR NUMBERS FOR TDY GIVEN ABUNDANCE OF CLDS AND RA
ACROSS MTNS AND NUDGE TOWARD WARMER GUIDANCE ACROSS SE OH WHERE
SOME PARTIAL CLEARING MAY BE REALIZED THIS AFTN. WENT WITH WARMER
GUIDANCE FOR LOWS TONIGHT EAST OF OH RVR WITH SOME LINGERING CLDS.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
MODELS SHOW HIGH PRESSURE OVER THE REGION FOR THURSDAY AND FRIDAY.
FOR SATURDAY...MODELS DISAGREE WITH EACH OTHER AND CHANGE WITH EVERY
RUN. THIS DOES NOT LEAD TO A HIGH CONFIDENCE FORECAST. CURRENT
PACKAGE IS SUPPORTED BY THE CANADIAN MODEL...SO WILL STAY THE COURSE
FOR NOW UNTIL CONFIDENCE LEVELS INCREASE IN A SOLUTION.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AT THE OUTSET OF THE PERIOD FRIDAY EVENING A TROUGH WILL BE DIGGING
SOUTHWARD THROUGH THE CENTRAL CONUS...WITH POSITIVELY-TILTED AXIS
ROUGHLY FROM UPPER MID-WEST TO TEXAS. AT THE SURFACE A FRONT WILL BE
QUASI-STATIONARY TO THE NORTHWEST OF AREA OVER CENTRAL AND WESTERN
OHIO. TRIMMED BACK POPS OVER THE AREA FRI EVE WITH THIS IN MIND.
BOTH OPERATIONAL EXTENDED MODELS IS GOOD AGREEMENT WITH REGARD TO
THIS TROUGH CLOSING OFF ON ITS SOUTHERN END OVER THE SE TEXAS/LA
REGION BY SAT MORNING AND PROGRESSING THIS LOW EASTWARD ALONG THE
GULF COAST TOWARDS THE FLORIDA PANHANDLE BY EARLY SUN. GEFS MEAN
HEIGHT SOMEWHAT SURPRISINGLY KEEPS THIS LOW OPEN AND THEREFORE A BIT
MORE PROGRESSIVE...WITH ONLY FOUR OF ITS MEMBERS DEPICTING A CLOSURE
AT SUN 06Z. HOWEVER...BOTH NCEP AND EC ENSEMBLE MEAN HEIGHTS DO SHOW
THIS LOW CLOSING OFF AND THUS WILL BASE THE FORECAST ON THIS
SOLUTION.
SATURDAY THE UPPER LOW MOVING ACROSS THE GULF COAST WITH SFC
LOW...ALONG WITH A TROUGH MOVING ACROSS THE GREAT LAKES
REGION...WILL FINALLY ALLOW THE FRONT TO THE NORTHWEST TO BEGIN
PUSHING SE ACROSS THE AREA. STILL SOME DIFFERENCES IN TIMING BUT AT
THIS POINT THE FRONT IS EXPECTED TO BE AROUND THE OHIO RIVER AREA BY
18Z SAT AND NEAR THE EASTERN CWA BORDER BY 00Z SUN. LIFT AND
ABUNDANT LOW LEVEL MOISTURE STILL SUPPORT INCREASING CHANCES OF RAIN
SATURDAY AND SATURDAY EVENING. BEYOND THIS PERIOD MODELS BEGIN TO
DIVERGE WITH RESPECT TO THE DETAILS SURROUNDING CLOSED LOW AND
NORTHERN TROUGH...WITH THE GFS MORE PROGRESSIVE IN MOVING THE CLOSED
LOW NE AND INTO PHASE WITH THE DIVING NORTHERN TROUGH BY EARLY
MON...AND THE EC MUCH SLOWER IN PROGRESSION AND KEEPING THE TWO
SYSTEMS SEPARATE. NO REAL LEANING ONE WAY OR THE OTHER WHEN IT COMES
TO ENSEMBLES HERE...AND WITH NO REAL WAY TO DIFFERENTIATE AM
INCLINED TO BELIEVE THE SLOWER SOLN AS MODELS TEND TO BE MORE
PROGRESSIVE THAN REALITY WITH CLOSED SYSTEMS. THIS SOLUTION KEEPS
THE NORTHERN TROUGH DOMINANT IN ITS MOVING PRECIP EAST OF AREA
QUICKLY AFTER SUNDAY. HOWEVER...AGAIN WITH THE UNCERTAINTY I WILL
KEEP SOME MENTION OF POPS IN FOR MONDAY INTO TUESDAY.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
13Z WEDNESDAY TO 12Z THURSDAY...
13Z UPDATE...HAVE ADJUSTED NORTHERN EDGE OF RAIN A BIT FARTHER NORTH
TODAY...BUT STILL MOSTLY EAST OF A HTS-CKB LINE. IN TURN...INTRODUCED
QUICKER PREVAILING IFR CONDITIONS INTO SOUTHERN AND CENTRAL
MOUNTAINS THIS MORNING...AND OCCASIONAL MVFR CEILINGS MAY CREEP
NORTH AND WEST TO NEAR THE I79 CORRIDOR INCLUDING CRW BEFORE
SHIFTING EAST THIS AFTERNOON. ELSEWHERE...LITTLE CHANGE.
PREVIOUS DISCUSSION...
S/W TROF MOVING THRU COMBINED WITH ISENTROPIC LIFT AND SFC WAVE
WILL PROVIDE FOR MAINLY -RA ACROSS ALONG AND EAST OF US119/I79
CORRIDOR THRU 15Z BEFORE CONFINING ACROSS MTNS. GENERALLY MVFR
CIGS AND VSBY DEVELOPING ACROSS THE WV MTNS. EXCEPTION WILL ACROSS
EASTERN SLOPES WHERE SE FLOW NEAR SFC WILL ALLOW FOR IFR CIGS TDY.
ELSEWHERE...-RA MAY PUSH FURTHER W TO A KCRW TO KCKB LINE. HOWEVER
EXPECTING MAINLY VFR CONDITIONS WITH CIGS LOWERING INTO LOW END OF
RANGE AND VSBY REMAINING UNRESTRICTED. SYS SLOWLY PULLS E WITH
GRADUAL CLEARING ACROSS SE OH THIS AFTN. CLDS WILL HANG TOUGH E OF
OH RVR THRU 00Z AS LLVL MOISTURE SLOW TO DEPART. EXPECT MVFR CIGS
OVER MTNS TO LWR INTO IFR TONIGHT WITH VSBY APPROACHING IFR AS
WELL...INCLUDING KBKW. LIFR STRATUS POSSIBLE ACROSS AFTER 06Z MTN
TAF SITES.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF MVFR CIGS THIS MORNING
AND TDY. EXTENT OF -RA MAY VARY. IFR CIGS MAY EXPAND FURTHER W
FROM EASTERN SLOPES TDY TO INCLUDE KBKW. LOW STRATUS AND SOME FG MAY
DEVELOP ACROSS WV LOWLANDS TONIGHT ESPECIALLY IN AREAS THAT
RECEIVED RAINFALL.
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 M L L L M L L L L H H H
HTS CONSISTENCY H M L M M M M M H H H H
BKW CONSISTENCY M L M M M M M M L L L L
EKN CONSISTENCY M L L L H H H M M M M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H M M L L H H H H
AFTER 12Z THURSDAY...
IFR CONDITIONS TONIGHT SOUTHWEST VIRGINIA AND THE SOUTHERN WV
MOUNTAINS.
IFR CONDITIONS POSSIBLE FRIDAY NIGHT AND SATURDAY IN CLOUDS AND
PRECIPITATION.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...JMV/30
SHORT TERM...RPY
LONG TERM...50
AVIATION...JMV/30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
658 AM EDT WED APR 18 2012
.SYNOPSIS...
A WAVE DEVELOPS AND AFFECTS MAINLY THE MOUNTAINS TODAY. HIGH
PRESSURE THURSDAY AND FRIDAY. A STORM SYSTEM FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATED...
PUSHED POP GRADIENT A LITTLE FURTHER NW THIS MORNING. LATEST RADAR
MOSAIC AND OBS SHOW TIGHT PCPN SHIELD RUNNING ALONG 119/I79
CORRIDOR AND GENERALLY HOLDING THIS LINE. THUS HAVE USED THIS AS
ORIENTATION FOR DETERMINISTIC POPS WITH ACE ACROSS MTNS. SHOULD
SEE THIS SLOWLY PUSH OFF TO E LATER THIS MORNING...WITH MTNS
STAYING IN RA THRU AFTN.
PREVIOUS DISCUSSION BELOW...
THERE CONT TO BE SOME DISAGREEMENT WITH NW EXTENT OF MEASURABLE
PCPN THIS MORNING WITH THE NAM THE LONE GUN KEEP BULK OF QPF
ACROSS THE MTNS. MOST OTHER GUIDANCE HAS SHIFTED SOME TO NW WITH
MEASURABLE QPF...TAKING .1 TO .25 INCH CONTOUR THRU THE COAL
FIELDS TO ABOUT CRW AREA AND N UP I79 CORRIDOR. PLACEMENT OF LIFT
AND FORCING SIMILAR THOUGH. LOOKING AT MDL SOUNDINGS...ONE SEES
WHERE NAM IS HOLDING ON DRY AIR NEAR THE SFC W OF MTNS AS OTHER
MDLS INCLUDING THE RUC SATURATE THE COLUMN BY 12Z W TO CRW. LATEST
RADAR MOSAIC SHOWS SOLID AREA OF MAINLY -RA OVER SW VA AND S WV
MTNS ATTM. THIS IS TRYING TO PUSH NW SLOWLY BUT HAVING A HARD TIME
GIVEN DRY AIR IN FRONT OF IT. WILL NUDGE HIGHER POPS A HAIR NW
09-15Z THIS MORNING BUT NOT AS MUCH AS MODEL CONSENSUS SUGGESTS
WITH A BELIEF THE NAM MAY BE HANDLING THE BL MOISTURE BETTER AS
EVEN WHERE THERE IS RA OUT THERE...NOT SEEING ANY VSBY
RESTRICTIONS OR LOW CIGS CURRENTLY. WILL CONT TO MONITOR NEXT FEW
HRS FOR ANY FURTHER ADJUSTMENT TO NW.
OTHERWISE REMAINDER OF PREV FCST LOOKS GOOD. S/W TROF AXIS PUSHES
THRU THIS AFTN TAKING MUCH OF THE DEEP MOISTURE WITH IT AS SFC WAVE
PUSHES OFF TO NE. WILL GRADUALLY BRING POPS DOWN FROM W TO E THIS
AFTN...WITH AREA POP FREE BY 03Z. CONCERNING CLDS...WILL HOLD WV/SW
VA ZONES IN CLDS MUCH OF THE DAY AND ALLOW FOR SOME CLEARING ACROSS SE
OH/NE KY LATER IN AFTN. MAY SEE LOW STRATUS HOLD IN MTNS TONIGHT
WITH FG FOR ANY AREAS THAT RECEIVE RA THAT MANAGE TO CLR.
WILL LEAN TOWARD LWR NUMBERS FOR TDY GIVEN ABUNDANCE OF CLDS AND RA
ACROSS MTNS AND NUDGE TOWARD WARMER GUIDANCE ACROSS SE OH WHERE
SOME PARTIAL CLEARING MAY BE REALIZED THIS AFTN. WENT WITH WARMER
GUIDANCE FOR LOWS TONIGHT EAST OF OH RVR WITH SOME LINGERING CLDS.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
MODELS SHOW HIGH PRESSURE OVER THE REGION FOR THURSDAY AND FRIDAY.
FOR SATURDAY...MODELS DISAGREE WITH EACH OTHER AND CHANGE WITH EVERY
RUN. THIS DOES NOT LEAD TO A HIGH CONFIDENCE FORECAST. CURRENT
PACKAGE IS SUPPORTED BY THE CANADIAN MODEL...SO WILL STAY THE COURSE
FOR NOW UNTIL CONFIDENCE LEVELS INCREASE IN A SOLUTION.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AT THE OUTSET OF THE PERIOD FRIDAY EVENING A TROUGH WILL BE DIGGING
SOUTHWARD THROUGH THE CENTRAL CONUS...WITH POSITIVELY-TILTED AXIS
ROUGHLY FROM UPPER MID-WEST TO TEXAS. AT THE SURFACE A FRONT WILL BE
QUASI-STATIONARY TO THE NORTHWEST OF AREA OVER CENTRAL AND WESTERN
OHIO. TRIMMED BACK POPS OVER THE AREA FRI EVE WITH THIS IN MIND.
BOTH OPERATIONAL EXTENDED MODELS IS GOOD AGREEMENT WITH REGARD TO
THIS TROUGH CLOSING OFF ON ITS SOUTHERN END OVER THE SE TEXAS/LA
REGION BY SAT MORNING AND PROGRESSING THIS LOW EASTWARD ALONG THE
GULF COAST TOWARDS THE FLORIDA PANHANDLE BY EARLY SUN. GEFS MEAN
HEIGHT SOMEWHAT SURPRISINGLY KEEPS THIS LOW OPEN AND THEREFORE A BIT
MORE PROGRESSIVE...WITH ONLY FOUR OF ITS MEMBERS DEPICTING A CLOSURE
AT SUN 06Z. HOWEVER...BOTH NCEP AND EC ENSEMBLE MEAN HEIGHTS DO SHOW
THIS LOW CLOSING OFF AND THUS WILL BASE THE FORECAST ON THIS
SOLUTION.
SATURDAY THE UPPER LOW MOVING ACROSS THE GULF COAST WITH SFC
LOW...ALONG WITH A TROUGH MOVING ACROSS THE GREAT LAKES
REGION...WILL FINALLY ALLOW THE FRONT TO THE NORTHWEST TO BEGIN
PUSHING SE ACROSS THE AREA. STILL SOME DIFFERENCES IN TIMING BUT AT
THIS POINT THE FRONT IS EXPECTED TO BE AROUND THE OHIO RIVER AREA BY
18Z SAT AND NEAR THE EASTERN CWA BORDER BY 00Z SUN. LIFT AND
ABUNDANT LOW LEVEL MOISTURE STILL SUPPORT INCREASING CHANCES OF RAIN
SATURDAY AND SATURDAY EVENING. BEYOND THIS PERIOD MODELS BEGIN TO
DIVERGE WITH RESPECT TO THE DETAILS SURROUNDING CLOSED LOW AND
NORTHERN TROUGH...WITH THE GFS MORE PROGRESSIVE IN MOVING THE CLOSED
LOW NE AND INTO PHASE WITH THE DIVING NORTHERN TROUGH BY EARLY
MON...AND THE EC MUCH SLOWER IN PROGRESSION AND KEEPING THE TWO
SYSTEMS SEPARATE. NO REAL LEANING ONE WAY OR THE OTHER WHEN IT COMES
TO ENSEMBLES HERE...AND WITH NO REAL WAY TO DIFFERENTIATE AM
INCLINED TO BELIEVE THE SLOWER SOLN AS MODELS TEND TO BE MORE
PROGRESSIVE THAN REALITY WITH CLOSED SYSTEMS. THIS SOLUTION KEEPS
THE NORTHERN TROUGH DOMINANT IN ITS MOVING PRECIP EAST OF AREA
QUICKLY AFTER SUNDAY. HOWEVER...AGAIN WITH THE UNCERTAINTY I WILL
KEEP SOME MENTION OF POPS IN FOR MONDAY INTO TUESDAY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
12Z WEDNESDAY TO 12Z THURSDAY...
S/W TROF MOVING THRU COMBINED WITH ISENTROPIC LIFT AND SFC WAVE
WILL PROVIDE FOR MAINLY -RA ACROSS ALONG AND EAST OF US119/I79
CORIDOR THRU 15Z BEFORE CONFINING ACROSS MTNS. GENERALLY MVFR
CIGS AND VSBY DEVELOPING ACROSS THE WV MTNS. EXCEPTION WILL ACROSS
EASTERN SLOPES WHERE SE FLOW NEAR SFC WILL ALLOW FOR IFR CIGS TDY.
ELSEWHERE...-RA MAY PUSH FURTHER W TO A KCRW TO KCKB LINE. HOWEVER
EXPECTING MAINLY VFR CONDITIONS WITH CIGS LOWERING INTO LOW END OF
RANGE AND VSBY REMAINING UNRESTRICTED. SYS SLOWLY PULLS E WITH
GRADUAL CLEARING ACROSS SE OH THIS AFTN. CLDS WILL HANG TOUGH E OF
OH RVR THRU 00Z AS LLVL MOISTURE SLOW TO DEPART. EXPECT MVFR CIGS
OVER MTNS TO LWR INTO IFR TONIGHT WITH VSBY APPROACHING IFR AS
WELL...INCLUDING KBKW. LIFR STRATUS POSSIBLE ACROSS AFTER 06Z MTN
TAF SITES.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF MVFR CIGS THIS MORNING
AND TDY. EXTENT OF -RA MAY VARY. IFR CIGS MAY EXPAND FURTHER W
FROM EASTERN SLOPES TDY TO INCLUDE KBKW. LOW STRATUS AND SOME FG MAY
DEVELOP ACROSS WV LOWLANDS TONIGHT ESPECIALLY IN AREAS THAT
RECEIVED RAINFALL.
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 M M L M L L L M H H H H
HTS CONSISTENCY H H H M L L L L H H H H
BKW CONSISTENCY L L L L L L L L H H H H
EKN CONSISTENCY M M M H M H H M M H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H M M M H H M L H H H H
AFTER 12Z THURSDAY...
IFR CONDITIONS TONIGHT SOUTHWEST VIRGINIA AND THE SOUTHERN WV
MOUNTAINS.
IFR CONDITIONS POSSIBLE FRIDAY NIGHT AND SATURDAY IN CLOUDS AND
PRECIPITATION.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...50
AVIATION...30
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1015 AM CDT WED APR 18 2012
.DISCUSSION.../ISSUED AT 1015 AM CDT/
MAIN CONCERN THIS MORNING IS THE PESKY STRATUS SINKING SOUTHWARD
ACROSS AREAS NORTH OF I90. RUC AND HRRR GUIDANCE SUGGESTS THAT THIS
SWATH OF CLOUDS WILL BE HALTED OVER THE I90 CORRIDOR AS IT SPREADS
IN MORE OF AN EASTERLY DIRECTION. LOW AND MID LEVEL DRYING THIS
AFTERNOON SHOULD BEGIN BREAKING UP THESE CLOUDS IN THE EARLY
AFTERNOON. MEANWHILE...HIGH CLOUDS AHEAD OF A DEVELOPING SYSTEM TO
OUR WEST WILL ALSO BEGIN SPREADING EASTWARD THROUGH LATE THIS
AFTERNOON. WITH THIS IN MIND...HAVE ADJUSTED SKY COVERAGE UPWARDS
THROUGH THE NEXT 12 HOURS TO FOLLOW THESE TWO FEATURES. ALSO LOWERED
HIGHS A BIT ACROSS THE NORTH WITH CLOUDY SKIES EXPECTED FOR THE
MAJORITY OF THE DAY.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
BIGGEST CHALLENGE WILL CONTINUE TO BE TIMING THE PROGRESS OF THE
1000 FOOT STRATUS LAYER NORTH OF I90 THROUGH THIS AFTERNOON. EXPECT
THIS LAYER TO PRIMARILY REMAIN NORTH OF I90 AND SPREAD EASTWARD
THROUGH THE NEXT SEVERAL HOURS. KFSD WILL BE ON THE SOUTHERN FRINGE
OF THIS LAYER AND IS LIKELY TO SEE LOW CEILINGS FOR AN HOUR OR TWO.
FOR THE ONSET OF THE TAF PERIOD...STRATUS SHOULD BEING ERODING AND
LIFTING FROM 18 TO 21Z WHILE HIGHER CLOUDS BEING BUILDING IN FROM
THE WEST. THE NEXT SYSTEM WILL SPREAD SHOWERS AND ISOLATED
THUNDERSTORMS FROM WEST TO EAST FROM 03Z/THU TO THE END OF THE TAF
PERIOD. TEMPORARY MVFR VISIBILITIES WILL BE POSSIBLE WITH
PRECIPITATION.
&&
.PREV DISCUSSION.../ISSUED AT 300 AM CDT/
SHORT WAVE MOVING THROUGH EASTERN SD AS OF 08Z WITH ASSOCIATED COLD
FRONT MOVING ACROSS SOUTHWEST MINNESOTA AND NORTHWEST IOWA. SHOWERS
ASSOCIATED WITH THIS FEATURE EAST OF I29 SHOULD EXIT CWA BY 12Z SO
WILL LEAVE FORECAST DRY TODAY. WEAK COLD AIR ADVECTION BEHIND THIS
FRONT WILL PRODUCE SLIGHTLY COOLER HIGHS TODAY...WITH THE BULK OF
THE COOLING ACROSS THE NORTHERN CWA. SHOULD SEE PLENTY OF SUNSHINE
MOST PLACES...WITH INCREASING CLOUDS AHEAD OF NEXT WAVE LATER THIS
AFTERNOON ACROSS THE WEST.
WILL SEE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WITH THIS NEXT
WAVE...WITH THE BEST CHANCE OF RAIN LATER TONIGHT INTO THURSDAY
MORNING. WILL KEEP MENTION OF CHANCE OF THUNDERSTORMS ACROSS
SOUTHERN CWA TONIGHT CLOSER TO SURFACE FRONT WHICH WILL STALL
ACROSS NEBRASKA AND IOWA. MODELS SEEM MORE IN AGREEMENT WITH BULK OF
RAIN LIMITED TO SOUTHEAST CWA THURSDAY AFTERNOON...SO WILL TRIM THE
AFTERNOON POPS ACROSS THE NORTHWEST. WITH PLENTY OF CLOUDS AND EAST
TO NORTHEAST LOW LEVEL FLOW...WITH BE A CHILLY DAY MOST PLACES.
ANOTHER WEAK WAVE SLIDES SOUTHEAST ACROSS CWA THURSDAY NIGHT...BUT
MOISTURE WILL BE LIMITED AND WILL ONLY MENTION 20% POPS WITH THIS
FEATURE.
SHOULD DRY OUT FRIDAY BUT WILL REMAIN COOL WITH HIGHS ONLY IN THE
50S. FLOW ALOFT WILL SPREAD HIGHS CLOUDS ACROSS CWA ON FRIDAY...SO
PARTLY SUNNY AT BEST.
NORTHWEST FLOW ALOFT WILL BRING ANOTHER WAVE SOUTHEAST ACROSS CWA
LATER FRIDAY NIGHT AND SATURDAY AND COULD TRIGGER A FEW SHOWERS OVER
THE NORTHEAST HALF OF CWA AHEAD OF WEAK WARM FRONT. TEMPERATURES
WILL VARY QUITE A BIT FOR HIGHS ON SATURDAY...WITH AREAS EAST OF I29
REMAINING IN THE 50S WITH NEAR 70 ACROSS THE FAR WEST.
WARMER AIR WILL SPREAD ACROSS THE CWA SUNDAY INTO TUESDAY WITH ABOVE
NORMAL TEMPERATURES EXPECTED. THE WARMEST DAY WILL BE TUESDAY WITH
HIGHS IN THE 70S TO LOWER 80S. WILL LEAVE SUNDAY THROUGH TUESDAY DRY
WITH A CHANCE OF SHOWERS AND THUNDERSTORMS MID WEEK WITH NEXT
FRONT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
903 AM CDT WED APR 18 2012
.UPDATE...
SENDING OUT A QUICK UPDATE THIS MORNING SINCE IT`S CLOUDY
OUTSIDE...AND CURRENTLY AT LEAST 3 HOURS AWAY FROM SEEING ANY
SEMBLANCE OF CLEARING...PER RUC 925HPA RH PROGS. DID NOT ADJUST
HIGH TEMPERATURES DOWN YET...AS THERE IS STILL PLENTY OF TIME FOR
TEMPERATURE RECOVERY...CURRENTLY JUST 10 TO 15 DEGREES OFF
FORECAST HIGHS.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
THE WET WEATHER PATTERN WILL CONTINUE THROUGH AT LEAST THURSDAY
FOR THE NORTHERN PLAINS.
AS OF 8Z...AN AREA OF LOW PRESSURE IS LOCATED OVER WESTERN
MINNESOTA WITH LIGHT SHOWERS ONGOING ACROSS THE I-29 CORRIDOR. THESE
SHOWERS WILL PUSH EAST OF THE CWA BY 12Z WITH GENERALLY DRY
CONDITIONS EXPECTED FOR THE REST OF THE DAY PERIOD. WITH PARTLY TO
MOSTLY SUNNY SKIES...HIGH TEMPERATURES SHOULD WARM INTO THE 50S
AND 60S. HOWEVER BY TONIGHT...ANOTHER SHORTWAVE WILL BRING A
DECENT CHANCE FOR SHOWERS TO THE REGION. WITH LIMITED INSTABILITY
OR FORCING...WILL KEEP THE PCPN MENTION AS JUST RAIN SHOWERS.
RAINFALL AMOUNTS BETWEEN A QUARTER TO A HALF INCH COULD BE
POSSIBLE WITH THIS STORM SYSTEM.
PCPN CHANCES ON THURSDAY...ARE BEGINNING TO LOOK LIKELY THEN
BEFORE. LIGHT WRAP AROUND SHOWERS COULD BE POSSIBLE DURING THE
MORNING HOURS...ESPECIALLY IN THE EASTERN CWA. BY THE AFTERNOON
HOWEVER...MODELS SEEM TO DISAGREE WITH THE STRENGTH AND PLACEMENT
OF ANOTHER SHORTWAVE TROF. AT THIS TIME...IT SEEMS AS THOUGH THIS
WAVE IS TRENDING FURTHER NORTH WITH DRY CONDITIONS POSSIBLE IN THE
SOUTHERN CWA.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
OVERALL THE MODELS REMAIN CONSISTENT THROUGH THE LONG TERM.
SLOWING FLOW SHOULD RESULT IN MORE AMPLITUDE AT LEAST FOR A TIME
LATE THIS WEEKEND INTO EARLY NEXT WEEK AS HIGH PRESSURE ALOFT
BUILDS INTO THE PLAINS. BUT FIRST A DIGGING SYSTEM ON FRIDAY NIGHT
AND SATURDAY SHOULD BRING A FEW SHOWERS TO THE REGION. AFTER THAT
IT DRIES OUT UNTIL PERHAPS LATE IN THE PERIOD AS THE FLOW AGAIN
GETS FLATTENED BY PROGRESSIVE ENERGY COMING OFF THE PACIFIC AND
INTO THE WESTERN CONUS/WESTERN CANADA.
UNDERNEATH HIGH PRESSURE ALOFT...TEMPERATURES SHOULD FAVOR ABOVE
NORMAL THROUGH THE PERIOD.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
A BATCH OF MVFR CIGS IS ADVECTING SOUTH OVER THE AREA AND MAY
REMAIN AROUND THROUGH THE NOON HOUR BEFORE MIXING OUT. VSBYS
SHOULD BE GENERALLY VFR EXCEPT FOR PATCHY MVFR DUE TO FOG. RAIN
WILL MOVE FROM WEST TO EAST ACROSS THE REGION THIS EVENING AND
OVERNIGHT WITH IFR CIGS POSSIBLE AFTER MIDNIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...SD
LONG TERM...TDK
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
615 AM CDT WED APR 18 2012
.DISCUSSION.../ISSUED AT 300 AM CDT/
SHORT WAVE MOVING THROUGH EASTERN SD AS OF 08Z WITH ASSOCIATED COLD
FRONT MOVING ACROSS SOUTHWEST MINNESOTA AND NORTHWEST IOWA. SHOWERS
ASSOCIATED WITH THIS FEATURE EAST OF I29 SHOULD EXIT CWA BY 12Z SO
WILL LEAVE FORECAST DRY TODAY. WEAK COLD AIR ADVECTION BEHIND THIS
FRONT WILL PRODUCE SLIGHTLY COOLER HIGHS TODAY...WITH THE BULK OF
THE COOLING ACROSS THE NORTHERN CWA. SHOULD SEE PLENTY OF SUNSHINE
MOST PLACES...WITH INCREASING CLOUDS AHEAD OF NEXT WAVE LATER THIS
AFTERNOON ACROSS THE WEST.
WILL SEE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WITH THIS NEXT
WAVE...WITH THE BEST CHANCE OF RAIN LATER TONIGHT INTO THURSDAY
MORNING. WILL KEEP MENTION OF CHANCE OF THUNDERSTORMS ACROSS
SOUTHERN CWA TONIGHT CLOSER TO SURFACE FRONT WHICH WILL STALL
ACROSS NEBRASKA AND IOWA. MODELS SEEM MORE IN AGREEMENT WITH BULK OF
RAIN LIMITED TO SOUTHEAST CWA THURSDAY AFTERNOON...SO WILL TRIM THE
AFTERNOON POPS ACROSS THE NORTHWEST. WITH PLENTY OF CLOUDS AND EAST
TO NORTHEAST LOW LEVEL FLOW...WITH BE A CHILLY DAY MOST PLACES.
ANOTHER WEAK WAVE SLIDES SOUTHEAST ACROSS CWA THURSDAY NIGHT...BUT
MOISTURE WILL BE LIMITED AND WILL ONLY MENTION 20% POPS WITH THIS
FEATURE.
SHOULD DRY OUT FRIDAY BUT WILL REMAIN COOL WITH HIGHS ONLY IN THE
50S. FLOW ALOFT WILL SPREAD HIGHS CLOUDS ACROSS CWA ON FRIDAY...SO
PARTLY SUNNY AT BEST.
NORTHWEST FLOW ALOFT WILL BRING ANOTHER WAVE SOUTHEAST ACROSS CWA
LATER FRIDAY NIGHT AND SATURDAY AND COULD TRIGGER A FEW SHOWERS OVER
THE NORTHEAST HALF OF CWA AHEAD OF WEAK WARM FRONT. TEMPERATURES
WILL VARY QUITE A BIT FOR HIGHS ON SATURDAY...WITH AREAS EAST OF I29
REMAINING IN THE 50S WITH NEAR 70 ACROSS THE FAR WEST.
WARMER AIR WILL SPREAD ACROSS THE CWA SUNDAY INTO TUESDAY WITH ABOVE
NORMAL TEMPERATURES EXPECTED. THE WARMEST DAY WILL BE TUESDAY WITH
HIGHS IN THE 70S TO LOWER 80S. WILL LEAVE SUNDAY THROUGH TUESDAY DRY
WITH A CHANCE OF SHOWERS AND THUNDERSTORMS MID WEEK WITH NEXT
FRONT.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
BIGGEST CHALLENGE THIS MORNING WILL BE UNCERTAINTY REGARDING STRATUS
COVERAGE. STRATUS HAS DEVELOPED ACROSS NORTH DAKOTA AND NORTH
CENTRAL SOUTH DAKOTA EARLY THIS MORNING...AND LOOKING TO BE HEADED
TO THE SOUTH. MODELS NOT HANDLING IT VERY WELL...THOUGH RUC HINTING
AT IT MAKING INTO THE HURON AREA DURING THE MORNING HOURS. QUESTION
THEN BECOMES HOW LONG IT WILL HANG OVER THE AREA AND HOW FAR SOUTH
IT WILL MAKE IT. AT THIS POINT...INCLUDE IN KHON TAF THROUGH
15Z...AND KEPT IT OUT OF KFSD...THOUGH UNCERTAINTY FAIRLY HIGH.
AFTER ANY STRATUS DISSIPATES LATER IN THE MORNING EXPECT VFR
CONDITIONS INTO THIS EVENING...BEFORE THE NEXT SYSTEM BRINGS SHOWERS
INTO THE AREA AFTER 03Z TONIGHT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS LA CROSSE WI
710 AM CDT WED APR 18 2012
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
710 AM CDT WED APR 18 2012
UPDATE...HAVE UPDATED THE FORECAST IN REGARD TO THE RAIN SHOWERS
CURRENTLY MOVING ACROSS THE REGION. MUCH OF THE LOW LEVEL MOISTURE
ADVECTION HAS BROUGHT THESE SHOWERS OUT AHEAD OF THE COLD FRONT
WITH MUCH OF THIS SHOWER ACTIVITY INTO CENTRAL WISCONSIN BY LATER
THIS MORNING. SKIES ARE ALSO CLEARING OUT ACROSS MINNESOTA...SO
HAVE GONE WITH A MUCH FASTER END TO THE RAIN THIS
MORNING/AFTERNOON ALONG WITH THE CLOUD TRENDS. HAVE HELD ONTO A
SMALL CHANCE FOR RAIN SHOWERS LATE THIS AFTERNOON FROM SOUTHWEST
WISCONSIN INTO NORTHEAST IOWA FOR THE OFF CHANCE THAT SOME SHOWERS
COULD DEVELOP ALONG THE STALLING OUT FRONT...WHICH IS WHAT THE
PAST FEW RUNS OF THE HRRR HAVE SHOWN. CONFIDENCE IN THOSE SHOWERS
ACTUALLY DEVELOPING AT THIS POINT ARE VERY LOW THOUGH GIVEN THE
ADVANCEMENT OF THIS MORNINGS CONVECTION.
PREVIOUS SHORT TERM AFD...
FIRST CONCERN WILL BE SHOWERS/THUNDERSTORMS TODAY...THEN RAIN AGAIN
THURSDAY INTO THURSDAY NIGHT WITH PERHAPS SOME SNOW MIXING IN
THURSDAY NIGHT. LOOK FOR A CHANCE OF LINGERING RAIN/SHOWERS ON
FRIDAY AS WELL.
CURRENT WATER VAPOR IMAGERY SHOWING A RATHER DYNAMIC MID-LEVEL WAVE
PUSHING INTO WESTERN MN. AT THE SURFACE...LOW PRESSURE WAS LOCATED
OVER SOUTHWEST MN WITH WARM AIR ADVECTION/STRONG ISENTROPIC LIFT AND
MOISTURE TRANSPORT PRODUCING SCATTERED SHRA/TS ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY REGION. SO FAR MOST OF THIS ACTIVITY HAS
BEEN CONFINED ALONG/NORTH OF I-90. MEANWHILE...THE COLD FRONT FROM
THE LOW WAS PRODUCING A DECENT LINE OF THUNDERSTORMS FROM SOUTHWEST
MN INTO NORTHEAST NEB. OTHERWISE...UNDER MOSTLY CLOUDY
SKIES...TEMPERATURES AT 3 AM ACROSS THE AREA WERE IN THE MID 40S TO
MID 50S.
FOR TODAY...WILL BE WATCHING THAT LOW AND COLD FRONT TRACK EAST
ACROSS THE AREA AS THE NAM HAS 0-3KM MUCAPE INCREASING INTO THE
800-1100 J/KG RANGE THIS MORNING AND AFTERNOON. THERE IS ALSO AMPLE
SHEAR PRESENT IN THIS LAYER IN THE 35-40KT RANGE. BUFKIT ALSO
SHOWING MOST OF THIS ACTIVITY FAIRLY HIGH BASED. SO...THINKING THERE
MAY BE AN OUTSIDE CHANCE OF SOME SUB-SEVERE HAIL/WIND WITH A FEW OF
THESE STORMS. HIGHEST THREAT AREA FOR THIS OCCURRING LOOKS TO BE
SOUTHEAST OF A LINE FROM NEAR SPARTA AND VIROQUA WI...TO NEAR
OELWEIN IA. OTHERWISE...LOOK FOR GUSTY SOUTHWEST WINDS THIS MORNING
IN THE 15-30 MPH RANGE SHIFT TO THE WEST/NORTHWEST THIS AFTERNOON
WITH HIGHS TOPPING OFF WELL INTO THE 60S.
FOR TONIGHT...WILL SEE CLEARING EARLY IN THE EVENING WITH THE COLD
FRONT SLIDING SOUTHEAST OF THE AREA AND THEN STALLING OUT ACROSS NORTHERN
IL INTO CENTRAL IA. WEAK CYCLOGENESIS OVER THE CENTRAL PLAINS WILL
THEN PRODUCE ISENTROPIC LIFT/MOISTURE TRANSPORT ACROSS THIS FRONTAL
BOUNDARY FOR INCREASING CLOUDS AGAIN AFTER MIDNIGHT. ANY RAIN LOOKS
LIKE IT WILL HOLD OFF SOUTH/WEST OF THE AREA. INCREASING ISENTROPIC
LIFT/MOISTURE TRANSPORT AHEAD OF THE THE WEAK WAVE OF LOW PRESSURE
OVER THE PLAINS SPREADS RAIN INTO THE AREA ON THURSDAY. NAM STILL
SHOWING SOME WEAK ELEVATED CAPE IN THE 850-700MB LAYER FOR PERHAPS
AN ISOLATED CLAP OR TWO OF THUNDER EMBEDDED IN THE RAIN SHIELD.
OTHERWISE...EASTERLY FLOW AND RAIN WILL MAKE FOR A RATHER RAW DAY
WITH HIGHS STRUGGLING INTO THE UPPER 40S TO MIDDLE 50S.
THE WAVE OF LOW PRESSURE MOVES ACROSS NORTHERN IL THURSDAY
NIGHT..DRAGGING COOLER AIR IN ACROSS THE REGION. THIS IS EXPECTED TO
PRODUCE A COOLING DEFORMATION AREA WITH A PERHAPS A MIX OF A
RAIN/SNOW ACROSS PORTIONS OF THE AREA LATE IN THE NIGHT. NO SNOW
ACCUMULATION IS EXPECTED THOUGH.
ON FRIDAY...THE LOW TRACK EAST INTO THE EASTERN GREAT LAKES REGION
WITH PERHAPS SOME LINGERING DEFORMATION PRECIPITATION IN THE
MORNING. MEANWHILE...THE COOL/RATHER DEEP MID-LEVEL TROUGH TRACKS
OVER OUR AREA DURING THE DAY. THE NAM QPF AND NAM BUFKIT HINTS AT
SOME SHOWER ACTIVITY UNDER THIS COLDER/CYCLONIC FLOW ALOFT. HELD
ONTO SOME LOWER-END 20-40 POPS TO HONOR THIS SIGNAL. LOOK FOR
CHILLIER THAN NORMAL HIGHS IN THE UPPER 40S TO LOWER 50S AS WELL.
CLEARING THEN EXPECTED FRIDAY NIGHT AS A WEAK RIDGE OF HIGH PRESSURE
DRIFTS ACROSS THE REGION WITH LOWS DIPPING INTO THE UPPER 20S TO
LOWER 30S. WILL HAVE TO KEEP THIS IN MIND FOR POSSIBLE FROST/FREEZE
HEADLINES.
.LONG TERM...SATURDAY THROUGH TUESDAY
330 AM CDT WED APR 18 2012
18.00Z GFS AND ECMWF IN PRETTY GOOD AGREEMENT THROUGH THE LONG TERM.
BOTH MODELS HAVE SATURDAY DRY WITH SURFACE RIDGE HOLDING ACROSS THE
AREA. TEMPERATURES STILL A BIT ON THE COOL SIDE THE THOUGH WITH
HIGHS IN THE LOW-MID 50S. WARM AIR ADVECTION AHEAD OF A WEAK
MID-LEVEL WAVE IN THE NORTHWEST FLOW ALOFT WILL INCREASE CLOUDS AND
PRODUCE A CHANCE OF -SHRA SATURDAY NIGHT. THIS WILL BE MAINLY
NORTHWEST OF A MEDFORD THROUGH WINONA AND DODGE CENTER LINE. THIS
WAVE WILL THEN PRODUCE A CHANCE OF SHRA THROUGH SATURDAY MAINLY EAST
OF THE MISSISSIPPI RIVER. SUNDAY NIGHT THROUGH MONDAY WILL SEE WARM
AIR ADVECTION ACROSS THE AREA WITH HIGHS MONDAY INCREASING INTO THE
UPPER 50S TO MIDDLE 60S. MODELS THEN SHOW A BIT MORE VIGOROUS
MID-LEVEL/SURFACE LOW PUSHING ACROSS SOUTHERN CANADA AND THE
NORTHERN PLAINS...TOWARD THE AREA MONDAY NIGHT THROUGH TUESDAY FOR A
CHANCE OF SHOWERS AND THUNDERSTORMS. LOOK FOR HIGHS ON TUESDAY WELL
INTO THE 60S.
&&
.AVIATION...TODAY AND TONIGHT
626 AM CDT WED APR 18 2012
A COLD FRONT MOVING THROUGH THE REGION WILL BRING RAIN AND A FEW
THUNDERSTORMS ON IN AHEAD OF IT. THIS RAIN IS TRACKING EASTWARD A
BIT FASTER THAN THE OVERNIGHT MODELS HAD BEEN PROGGING IT TO GO
EAST WITH THE BACK EDGE APPEARING TO BE THROUGH RST BY 12Z AND
LSE BY 13Z. ANY OF THE BACK SIDE SHOWERS WILL LIFT TO THE
NORTHEAST THIS MORNING ALONG WITH THE MID TO HIGH LEVEL CLOUD
COVER. THUS...EXPECTING A QUICK CLEAR OUT THIS MORNING...THOUGH
WINDS WILL REMAIN RATHER GUSTY FOR A PERIOD BEFORE LIGHTENING UP.
SOME CU MAY FORM THIS AFTERNOON...BUT SHOULD BE VFR AT ABOUT
5-6KFT. AFTER WINDS LIGHTEN AND SKIES CLEAR THIS AFTERNOON AND
TONIGHT...THE NEXT SYSTEM WILL MOVE INTO THE REGION OVERNIGHT AND
BRING HIGH LEVEL CLOUD COVER BACK IN. ANY RAIN SHOULD HOLD OFF
UNTIL AFTER 12Z THOUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
330 AM CDT WED APR 18 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM.... DAS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1018 AM MDT WED APR 18 2012
.UPDATE...CURRENT FORECAST TRENDS STILL LOOKING ON TRACK WITH NO
PLANS FOR CHANGES AT THIS TIME. FAR NORTHEAST CORNER STILL IN A
GENERAL AREA FOR TSTMS PER SPC. RUC SHOWS A BULLSEYE OF AROUND 400
CAPE AT THE SURFACE ALONG WITH SOME CIN...REST OF THE MODELS LESS
GENEROUS. THERE LOOKS TO BE SOME SURFACE CONVERGENCE WHICH COULD
HELP EXTINGUISH ANY CIN...BUT LOOKS MINIMAL. NOT INCLUDE ANY
THUNDER BUT WILL CONTINUE TO MONITOR.
&&
.AVIATION...CURRENT TAF TRENDS LOOKING ON TRACK. SOUTHEAST WINDS
TO SHIFT TO THE SOUTHWEST THEN TOWARD THE NORTHWEST DURING THE
AFTERNOON. POTENTIAL FOR WINDS TO BECOME A BIT NORTH OR NORTHEAST
TONIGHT...THOUGH STILL SOME UNCERTAINTY. SOME POTENTIAL FOR
CEILINGS AROUND 7000 FEET AGL NORTH AND EAST OF THE AREA AIRPORTS
THIS AFTERNOON ALONG WITH SOME VIRGA AND PERHAPS GUSTY WINDS. THIS
LOW THREAT SHOULD NOT AFFECT AREA AIRPORTS. SOME SHOWERS POSSIBLE
THIS EVENING...APPEARS CEILINGS SHOULD BE ABOVE ILS CONCERNS.
&&
.PREV DISCUSSION... /ISSUED 322 AM MDT WED APR 18 2012/
SHORT TERM...TODAY IS LOOKING A LOT LIKE YESTERDAY WITH ANOTHER
SHORT WAVE BRINGING MID AND HIGH LEVEL MOISTURE IN FROM THE WEST
DURING THE DAY. TWO MINOR DIFFERENCES...THERE IS A LITTLE WARM
ADVECTION ALOFT...AND THERE IS A BIT MORE MOISTURE ALOFT AS WELL.
IT LOOKS LIKE CLOUD COVER WILL HOLD TEMPERATURES RIGHT AT THE
CONVECTIVE TEMPERATURE...CREATING A VERY MARGINAL CONVECTIVE
ENVIRONMENT. I SUSPECT THAT CONVECTION TODAY WILL BE LIMITED TO
FAIRLY WEAK ACTIVITY IN THE ELEVATED MOIST LAYER...THE INCREASED
MOISTURE MAY RESULT IN MORE CLOUDS/VIRGA BUT NOT NECESSARILY ANY
MORE RAIN. I TRIMMED POPS BACK A LITTLE ON THE PLAINS WHERE THE
CHANCES ARE PRETTY LOW UNTIL EVENING WHEN BETTER LIFT ARRIVES.
MOIST LAYER MAY LOWER ENOUGH TO ALLOW SOME PRECIP TO REACH THE
SURFACE OVERNIGHT...MORE LIKELY IN THE NORTHERN PART OF THE AREA.
HIGHER POPS OF COURSE IN THE MOUNTAINS WHERE VIRGA TURNS INTO RAIN
AND SNOW SHOWERS AS YOU GO UPHILL...BUT NOT EXPECTING MUCH IN THE
WAY OF AMOUNTS...AND AGAIN BETTER NEARER THE NORTHERN BORDER.
TRIMMED TEMPERATURES BACK A FEW DEGREES IN LINE WITH THE LATEST
GUIDANCE...AND THE INCOMING CLOUD COVER.
LONG TERM...A MODERATE WEST TO NORTHWESTERLY FLOW ALOFT WILL BE
OVER CO THURSDAY AS A WEAK UPPER LEVEL TROUGH MOVES ACROSS THE
STATE. OVERALL THE MID AND UPPER LEVEL QG ASCENT IS WEAK BUT IT
IS PROGGED TO MOVE OVER THE CWFA AROUND 18Z. IN THE MOUNTAINS
DECENT MOISTURE...WITH A FAVORABLE OROGRAPHIC COMPONENT WILL BE IN
PLACE WITH NORTHWEST WINDS IN THE 25-30 KT RANGE AROUND 650 MB.
MID LEVEL INSTBY HOWEVER WILL BE FAIRLY WEAK. WL GO WITH LIGHT
SNOW AMOUNTS IN THE MOUNTAINS...GREATEST POTENTIAL FOR
ACCUMULATIONS WILL BE ALONG THE HIGHER WEST FACING SLOPES. ACROSS
THE NORTHEAST PLAINS...WL GO WITH PRIMARILY RAIN SHOWERS WITH THE
MENTION OF A FEW TSTMS. CAPES NOT VERY IMPRESSIVE WITH VALUES OF
150-250 J/KG IN THE AFTN. IN ADDITION TO THE AFTN HEATING...THE QG
ASCENT ASSOCIATED WITH THE TROUGH WILL BE PASSING OVER THE
NORTHEAST PLAINS IN THE AFTN. WL KEEP SOME SHOWERS GOING ACROSS
THE CWFA THURSDAY NIGHT...BUT OVERALL CONDITIONS WILL
IMPROVE...ESPECIALLY AFTER 06Z FRIDAY. FOR THE REMAINDER OF THE
PERIOD...IT WILL GENERALLY BE DRY AND WARMER AS A RIDGE OF HIGH
PRESSURE ESTABLISHES ITSELF OVER THE WESTERN U.S. THE RIDGE MAY
FLATTEN SOMEWHAT BY THE MIDDLE OF NEXT WEEK AS SOME SYSTEMS MOVE
ACROSS THE NORTHERN ROCKIES...BUT NOTHING SIGNIFICANT ENUF AT THIS
TIME TO WARRANT ADDITION OF ANY POPS TO THE GRIDS FOR NEXT WEEK.
AVIATION...VFR CONDITIONS EXPECTED THROUGH TONIGHT. THE WIND
SHOULD SHIFT TO A NORTH TO NORTHWEST DIRECTION IN THE MID TO LATE
AFTERNOON. SOME UNCERTAINTY ABOUT THE WIND DIRECTION
OVERNIGHT...BUT THERE WILL PROBABLY NOT BE MUCH CHANGE IN THE
EARLY EVENING AND SPEEDS WILL BE 10 KNOTS OR LESS.
HYDROLOGY...PCPN WILL BE FAIRLY LIGHT AS THE SYSTEM MOVES OVER
THE BURN AREAS ON THURSDAY SO DO NOT ANTICIPATE ANY FLOODING
ISSUES AT THIS TIME.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....COOPER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
106 PM EDT WED APR 18 2012
.SYNOPSIS...
HIGH PRESSURE ACROSS SOUTHERN CANADA TODAY WILL MOVE EASTWARD OFF
THE NEW ENGLAND COAST BY THURSDAY. MEANWHILE...A WEAK DISTURBANCE IS
THEN FORECAST TO TRACK SOUTH OF THE AREA TODAY INTO THURSDAY.
HIGH PRESSURE BUILDS BACK IN FOR THURSDAY AND THURSDAY NIGHT BEFORE
SHIFTING FARTHER TO THE EAST FRIDAY. THE NEXT COLD FRONT MOVES IN
DURING SATURDAY, HOWEVER AN AREA LOW LOW PRESSURE ALONG THIS FRONT
TRACKING TO OUR SOUTH WILL SLOWLY MOVE NORTHEASTWARD SUNDAY AND
MONDAY. THIS SYSTEM IS THEN FORECAST TO BE NEAR NEW ENGLAND TUESDAY
AS HIGH PRESSURE BUILDS TOWARD THE OHIO VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE AREA OF RAIN OVERRUNNING THE COOLER AIR NEAR THE SURFACE
CONTINUES TO MAKE PROGRESS INTO THE NORTHEAST DELAWARE AND
SOUTHERN DELAWARE. MOST OBSERVATIONS ARE SHOWING VERY LIGHT
RAIN...AND THIS MAKES SENSE CONSIDERING THAT THE 1200 UTC
SOUNDINGS SHOW DRY AIR UP THROUGH THE MID LEVELS. THE LATEST HRRR
RUN IS A BIT BEHIND REALITY THIS MORNING...BUT IS SHOWING A
NORTHEAST TREND WITH THE LIGHT RAIN.
CONSIDERING HOW DRY THE LOW LEVELS ARE...THE EXTENT AND AMOUNT OF
PRECIPITATION DEPICTED BY THE LATEST HRRR SEEMS A BIT OVERDONE.
HOWEVER...THE RADAR PRESENTATION (AND GROUND TRUTH BELOW THAT
ACROSS NORTHEAST MARYLAND) SUGGESTS THAT THE AREAL COVERAGE OF THE
RAIN NEEDED TO BE EXTENDED A BIT MORE ON THE LATEST FORECAST
UPDATE. IN ANY EVENT...THE RAINFALL SHOULD BE LIGHT (LESS THAN
0.10 INCHES ACROSS SOUTHERNMOST AREAS...AND PERHAPS NOT MUCH MORE
THAN A TRACE ACROSS SOUTH CENTRAL NEW JERSEY.
THE MID LEVEL CLOUDINESS IS NOT COMPLETELY OPAQUE (BASED ON THE
OBSERVATION HERE AT THE OFFICE)...AND THERE IS SOME SUNSHINE
ACROSS PORTIONS OF NEW JERSEY AND EASTERN PENNSYLVANIA. THIS
PROBABLY FILLS IN AS THE RAIN MOVES NORTHEAST. THE CLOUD COVER
SHOULD KEEP TEMPERATURES DOWN...ESPECIALLY ACROSS SOUTHERN AREAS.
THE 1200 UTC SOUNDINGS SHOW FULL SUN TEMPERATURES IN THE MID
60S...AND BASED ON CURRENT HOURLY TEMPERATURES...THAT APPEARS TOO
HIGH. ACCORDINGLY...HIGH TEMPERATURES WERE TRIMMED A BIT MORE
ACROSS SOUTHERN AREAS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
AN IMPULSE IN THE WESTERLY MID LEVEL FLOW IS FORECAST TO PASS
OVERHEAD THIS EVENING, WITH A MORE SUBSTANTIAL MID LEVEL SHORT WAVE
EXPECTED TO MOVE OFF THE MIDDLE ATLANTIC COAST OVERNIGHT. IT SHOULD
REMAIN MOSTLY CLOUDY IN OUR REGION TONIGHT WITH A CONTINUED CHANCE
OR SLIGHT CHANCE OF LIGHT SHOWERS, MAINLY IN OUR SOUTHERN COUNTIES.
THE WIND IS EXPECTED TO BE MOSTLY LIGHT AND VARIABLE, AND
TEMPERATURES SHOULD FALL INTO THE 40S AT MOST LOCATIONS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE BEGINNING OF THE LONG TERM IS DRY AS HIGH PRESSURE BUILDS BACK
ACROSS THE AREA. A FEW LINGERING CLOUDS WILL BE ACROSS ERN NJ AND
THE DELMARVA THU MORNING ASSOCIATED WITH THE DEPARTING WEAK LOW
FROM THE SHORT TERM...NO RAINFALL IS EXPECTED HOWEVER. IT WILL BE
SEASONABLY MILD ACROSS THE AREA THU WITH HIGHS IN THE MID TO UPPER
60S. THE DRY WEATHER WILL CARRY INTO FRI WITH EVEN MILDER
TEMPERATURES. HIGHS ON FRI WILL BE IN THE LOW TO MID 70S.
UNSETTLED WEATHER WILL BE ACROSS THE AREA FRI NIGHT INTO THE
WEEKEND. THE NEXT SYSTEM DOES APPEAR TO BE TRENDING A BIT SLOWER. I
KEPT THE SLGT CHC POPS IN FOR FRI NIGHT...ONLY TO MAINTAIN THE SENSE
OF CONTINUITY ACROSS THE CWA`S. IT WILL PROBABLY END UP BEING DRY
FRI NIGHT. THE STEADIER RAIN WILL PROBABLY ARRIVE LATER SAT WITH CHC
POPS IN THE GRIDS FOR THE AFTERNOON. AGAIN THE TREND TOWARD A LOWER
POPS OR A DRY FCST FOR SAT COULD STILL HAPPEN. THE EC/GFS SHOW THE
BULK OF THE RAIN FOR SAT NIGHT INTO MON WITH THE POTENTIAL FOR A
SOAKING RAIN DURING THE PERIOD. TOTAL QPF ENDING 12Z COULD BE 2 TO 3
INCHES NORTH/WEST AND CENTRAL AREAS WITH 1 TO 2 INCHES DELMARVA AND
ERN NJ. IT APPEARS THE RAINS WILL COME IN A LONG ENOUGH STRETCH TO
PRECLUDE ANY FLOODING PROBLEMS HOWEVER. HIGHS SUN AND MON WILL
MOSTLY BE IN THE UPPER 50S TO LOW 60S WITH THE CLOUDS AND RAIN.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS CONTINUE EARLY THIS AFTERNOON AS A BATCH OF RAIN
MOVES NORTHEAST THROUGH THE SOUTHERN TERMINALS. VFR CONDITIONS ARE
EXPECTED TO CONTINUE INTO THE EVENING AS THE FIRST BATCH OF RAIN
PASSES MAINLY SOUTH OF KPHL...WITH CEILINGS LOWERING TO NEAR 5000
FEET BY ABOUT 0100 UTC THURSDAY.
AS ANOTHER BATCH OF RAIN PASSES MAINLY SOUTH OF THE AREA TONIGHT
WITH SURFACE LOW PRESSURE...VFR CONDITIONS ARE EXPECTED. STATISTICAL
GUIDANCE IS SHOWING THE POTENTIAL FOR MVFR CEILINGS FOR SOUTHERN
TERMINALS (MAINLY SOUTH OF KPHL) BETWEEN 0900 UTC AND 1300 UTC
THURSDAY. GIVEN THE CEILINGS NOW IN CENTRAL VIRGINIA...THIS IS
POSSIBLE FOR KMIV AND KILG...BUT FOR NOW MVFR CEILINGS WERE NOT
INCLUDED FOR KPHL.
THE LOWER VFR CEILINGS SHOULD START TO BREAK AFTER 1400 UTC ACROSS
THE SOUTH...WITH VFR CONDITIONS ELSEWHERE. THE LIGHT GRADIENT SHOULD
ALLOW WINDS TO SWING AROUND TO SOUTH AND SOUTHWEST BY AFTERNOON...
GENERALLY LESS THAN 10 KNOTS.
OUTLOOK...
THU THRU FRI NIGHT...MOSTLY VFR.
SAT THRU SUNDAY...DETERIORATING CIGS/VSBYS WITH SHOWERS. LOW/MVFR
OR IFR POSSIBLE BY SUN.
&&
.MARINE...
THE GRADIENT HAS BACKED OFF CONSIDERABLY ACROSS THE NORTHERN OCEAN
WATERS HIS AFTERNOON...AND LOCAL SEA BREEZE CIRCULATIONS ARE
POSSIBLE WITH WINDS GENERALLY LESS THAN 10 KNOTS. FURTHER
SOUTH...THE NORTHEAST GRADIENT SI SLOWLY BACKING OFF...AND WINDS
SHOULD REMAIN BELOW 15 KNOTS. THE NORTHEAST SWELL IS STARTING TO
BUILD AT 44009...BUT FOR NOW SEAS SHOULD REMAIN BELOW 4 FEET THIS
AFTERNOON.
WAVE HEIGHTS ON OUR OCEAN WATERS SHOULD REMAIN AROUND 2 TO 3 FEET.
ON DELAWARE BAY, WAVE HEIGHTS SHOULD BE 2 FEET OR LESS FOR TODAY AND
TONIGHT.
OUTLOOK...
SUB-SCA CONDITIONS EXPECTED THU THRU SAT MORNING WITH WEAK HIGH
PRESSURE ACROSS THE WATERS. AN APPROACHING LOW/FRONT WILL CAUSE
INCREASING WINDS/SEAS LATER SAT WHICH COULD BRING SCA CONDITIONS.
ANY SCA CONDITIONS COULD LAST INTO SUN WITH THE SYSTEM MOVING
RATHER SLOWLY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...HAYES
SHORT TERM...IOVINO
LONG TERM...O`HARA
AVIATION...HAYES/O`HARA
MARINE...IOVINO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1208 PM CDT WED APR 18 2012
.DISCUSSION...
ISSUED 1003 AM CDT WED APR 18 2012
BAND OF RAIN SHOWERS ACROSS EASTERN IOWA HAS BEEN BREAKING UP THE
LAST FEW HOURS...WITH MAINLY THE ASSOCIATED ALTOCUMULUS CLOUDS
STILL EXPECTED TO AFFECT THE NORTHERN CWA LATER TODAY. LATEST NAM
AND HRRR MODELS HOLD ON TO ENOUGH OF THE PRECIPITATION TO JUSTIFY
HOLDING ONTO THE EXISTING 20 PERCENT RAIN CHANCES ACROSS THE FAR
NORTH THIS AFTERNOON. HAVE SENT SOME MINOR TWEAKS TO THE HOURLY
TEMPERATURE/SKY GRIDS...BUT NO CHANGE IS NEEDED TO THE WORDED
FORECASTS AT THIS TIME.
GEELHART
&&
.AVIATION...
ISSUED 1208 PM CDT WED APR 18 2012
BAND OF SHOWERS ACROSS SOUTHEAST IOWA CONTINUES TO DIMINISH AS IT
APPROACHES THE MISSISSIPPI RIVER. LATEST NAM/HRRR CONTINUES TO
HINT AT SOME REDEVELOPMENT MAINLY OVER NORTHERN ILLINOIS. CANNOT
RULE OUT A FEW BRIEF SHOWERS NEAR OR NORTH OF KPIA THIS
AFTERNOON...BUT COVERAGE THAT FAR SOUTH SHOULD BE SPARSE ENOUGH
TO PRECLUDE MENTION IN THE TAFS AT THIS TIME.
IN GENERAL...GUSTY SOUTH/SOUTHWEST WINDS TO CONTINUE THIS
AFTERNOON AT ALL SITES...WITH THE TYPICAL DIMINISHING EARLY THIS
EVENING. PERIODS OF CLOUDINESS SHOULD REMAIN FAIRLY ELEVATED...
MAINLY 9000 FEET OR ABOVE. AN APPROACHING COLD FRONT IS EXPECTED
TO BECOME STATIONARY OVER FAR NORTHERN ILLINOIS THIS EVENING...AND
THIS WILL KEEP WINDS SOUTHERLY THROUGH THURSDAY MORNING.
HOWEVER...ASIDE FROM THE ISOLATED AFTERNOON SHOWERS MENTIONED
EARLIER...MAIN PRECIPITATION THREAT SHOULD REMAIN NORTHWEST OF THE
TAF SITES.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 252 AM CDT WED APR 18 2012
SHORT TERM...TODAY THROUGH FRIDAY
LOW PRESSURE ANALYZED OVER WESTERN MINNESOTA AT 06Z WILL TRACK
NORTHEASTWARD TODAY...REACHING LAKE SUPERIOR BY LATE THIS
AFTERNOON. TRAILING COLD FRONT WILL GRADUALLY SETTLE SOUTHWARD
TOWARD ILLINOIS...WITH HIGH-RES MODELS SUGGESTING WIDELY SCATTERED
SHOWERS/STORMS DEVELOPING ALONG IT AFTER 21Z. WITH BOUNDARY
EXPECTED TO REMAIN WELL TO THE NORTH...HAVE ONLY INCLUDED A SLIGHT
CHANCE POP ACROSS THE FAR NORTHERN KILX CWA AROUND GALESBURG.
FURTHER SOUTH ACROSS THE REMAINDER OF THE AREA...EXPECT MOSTLY
SUNNY AND DRY CONDITIONS. AS PRESSURE GRADIENT TIGHTENS BETWEEN
HIGH ANCHORED OVER THE OHIO RIVER VALLEY AND APPROACHING COLD
FRONT...GUSTY S/SW WINDS WILL DEVELOP THIS AFTERNOON. FORECAST
SOUNDINGS AND NUMERIC GUIDANCE INDICATE GUSTS UP TO 25
MPH...PARTICULARLY ALONG/WEST OF THE I-55 CORRIDOR.
FRONT WILL STALL ACROSS NORTHERN ILLINOIS TONIGHT INTO THURSDAY...AS
IT BECOMES PARALLEL TO THE ZONAL UPPER FLOW. AS SUCH...BEST
FORCING FOR SHOWERS/STORMS WILL REMAIN TO THE NORTH OF CENTRAL
ILLINOIS ACROSS IOWA INTO NORTHERN ILLINOIS. HAVE MAINTAINED LOW
CHANCE POPS IN CLOSER PROXIMITY TO THE BOUNDARY FROM PEORIA
NORTHWARD...BUT HAVE GONE WITH A DRY FORECAST FURTHER SOUTH ACROSS
THE REST OF THE AREA. PARTIAL SUNSHINE AND A CONTINUED STRONG
SOUTHERLY FLOW WILL HELP PUSH HIGH TEMPERATURES WELL INTO THE 70S
ON THURSDAY.
MODELS CONTINUE TO SHOW SHORT-WAVE CROSSING THE ROCKIES AND SLOWLY
AMPLIFYING OVER THE MISSISSIPPI RIVER VALLEY TOWARD THE END OF
THE WEEK...GRADUALLY PUSHING THE STALLED FRONTAL BOUNDARY FURTHER
SOUTH AND EAST. THE GENERAL TREND OVER THE PAST SEVERAL MODEL RUNS
HAS BEEN TO SLOW DOWN THIS PROCESS AS UPPER WAVE DIGS INTO THE
DEEP SOUTH AND CUTS OFF ALONG THE GULF COAST. 00Z 18 APR SUITE HAS
CONTINUED THE SLOWING TREND...NOW FEATURING FRONT REMAINING IN THE
VICINITY AT LEAST THROUGH FRIDAY NIGHT AND PERHAPS INTO SATURDAY
MORNING ACROSS THE SOUTHEAST CWA. HAVE ADJUSTED POPS
ACCORDINGLY...FOCUSING HIGHEST RAIN CHANCES ACROSS THE ILLINOIS
RIVER VALLEY THURSDAY NIGHT...THEN EVERYWHERE FRIDAY/FRIDAY NIGHT.
LONG TERM...SATURDAY THROUGH TUESDAY
DUE TO THE SLOWER DEPARTURE OF THE FRONT...HAVE HELD ON TO LOW
CHANCE POPS ALONG/SOUTH OF I-70 INTO SATURDAY. ELSEWHERE AROUND
THE AREA...DRY AND MUCH COOLER WEATHER WILL BE ON TAP AS
NORTHWESTERLY FLOW PATTERN DEVELOPS ACROSS THE MIDWEST. WITH 850MB
TEMPS DROPPING INTO THE 0 TO 5C RANGE...HIGH TEMPS WILL ONLY REACH
THE 50S ON BOTH SATURDAY AND SUNDAY...WITH OVERNIGHT LOWS DIPPING
INTO THE 30S. FURTHER OUT...MODEL DISCREPANCIES CONCERNING THE
EVOLUTION OF THE EASTERN CONUS TROUGH PERSIST...HOWEVER GENERAL
CONSENSUS POINTS TO A CONTINUED COOL NORTHWESTERLY FLOW ACROSS
ILLINOIS THROUGH AT LEAST EARLY NEXT WEEK.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
1127 AM MDT WED APR 18 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH FRIDAY...
AVIATION DISCUSSION UPDATED.
UPDATED THE FORECAST TO INCREASE POPS ACROSS THE WESTERN ZONES FOR
THIS MORNING AND TO LOWER THE OVER ALL HIGH TEMPERATURES. MADE A
FEW CALLS TO SPOTTERS AND COULD ONLY FIND VERY LIGHT RAIN TO
SPRINKLES. RAISED THE POPS UP TO AROUND 80 TO 90 PERCENT FOR THIS
MORNING AND LEFT IT AROUND 50 PERCENT FOR THIS AFTERNOON. THE HIGH
POPS FOR THIS MORNING ARE BASICALLY SAYING A VERY HIGH CHANCE OF
SPRINKLES TO MAYBE A FEW HUNDREDTHS OF AN INCH IF YOU ARE LUCKY.
SINCE WE HAVE THICKER CLOUD COVER AND THE ONSET OF PRECIPITATION
DECIDED TO LOWER THE TEMPERATURES THIS MORNING BY ALMOST 10
DEGREES ACROSS THE NORTHERN ZONES. CURRENT READING ARE STILL IN
THE UPPER 30S TO LOWER 40S ACROSS EASTERN MONTANA. EXPECT HIGHS TO
RANGE FROM THE MID 40S NORTH TO THE MID 50S ACROSS THE YELLOWSTONE
VALLEY. REST OF THE SHORT TERM FORECAST LOOKS GOOD. RSMITH
PREVIOUS DISCUSSION...THE SHORT TERM FORECAST IS A HARD ONE
TODAY FOR NORTHEAST MONTANA... MANY VARIABLES PLAYING INTO THE
FORECAST EQUATION FOR THE NEXT 48 HOURS.
FOR THE FIRST 12 HOUR TOOK THE HRRR FOR THE POPS/QPF FORECAST. IT
HAS PREFORMED VERY WELL THIS SPRING SEASON. PLUS THE GFS/NAM AGAIN
ARE BRINGING HIGH QPF VALUES TO NORTHEAST MONTANA. THE MODELS HAVE
A POOR TRACK RECORD IN THE PAST MONTH WITH FORECASTING QPF OVER
NORTHEAST MONTANA WITH A TREMENDOUS WET BIAS. MODEL SOUNDINGS SHOW
AT THE GGW POINT ...ALONG WITH BUFR SOUNDINGS... A SLOW MOISTENING
OF THE DRY LOW LEVELS THROUGH THE AFTERNOON HOURS. SPLIT THE
WEATHER GRIDS FOR THE FIRST 12 HOURS INTO 3 HOUR BLOCKS. DID THIS
TO SHOW THE STUBBORNLY SLOW PROGRESS OF MEASURABLE PRECIPITATION
ACROSS THE REGION. DO EXPECT LOTS OF VIRGA AND GUSTY WINDS THIS
AFTERNOON AS THE ATMOSPHERE MOISTENS UP. DECIDED TO FLY THE LAKE
WIND ADVISORY WITH THE MARGINAL 15 TO 25 MPH WINDS DUE TO THE GUST
FACTOR THAT COULD SURPRISE IN EXPERIENCED BOATERS EARLY IN THE
SEASON.
TONIGHT WENT WITH HIGH POP LOW QPF/LITTLE OR CHANCE OF WETTING
RAIN SOLUTION. CONFIDENCE IS MODERATE... MODELS ALL ARE GOING FOR
A WETTING RAIN ACROSS MOST OF NORTHEAST MONTANA. HOWEVER THE MODEL
PERFORMANCE ON RAINFALL HAS BEEN POOR AND OVER FORECASTING
RAINFALL.
ON THURSDAY AS THE WINDS SWITCH TO THE WEST ACROSS THE AREA CLOUD
BASES WILL RISE AND AGAIN THE BOUNDARY LAYER SHOULD DRY OUT
KEEPING MEASURABLE PRECIPITATION VALUES LOW. THE ONE ISSUE THAT
COULD INCREASE POPS THURSDAY AFTERNOON IS VERY STEEP LAPSE RATES
WHICH COULD SPARK A THUNDERSTORM AND CREATE SMALL AREAS OF HIGHER
RAINFALL.
THURSDAY NIGHT THE DAKOTA LOW WILL CONTINUE TO DRIFT EAST KEEPING
MOST AREAS DRY. ON FRIDAY A LOW MOVES OFF THE ALBERTA ROCKIES AND
SLIDES ACROSS SASKATCHEWAN INTO NORTH DAKOTA IN THE NORTHWEST FLOW
AHEAD OF THE BUILDING RIDGE. THIS MIGHT BRING ANOTHER VERY SLIGHT
CHANCE OF WETTING RAINS WITH STRONGER SHOWERS ACROSS THE NORTHERN
TIER OF ZONES. OTHERWISE MORE DUST SETTLING SHOWERS WITH LITTLE
RAIN RELIEF EXPECTED. PROTON
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
THE LAST IN A SERIES OF SEVERAL SHORTWAVE DISTURBANCES FROM THE W
MOVES OUT OF THE AREA FRI NIGHT. THEN A BUILDING UPPER RIDGE FROM
THE S OVER THE WEEKEND BRINGS SUNNY AND WARMER WEATHER. THE RIDGE
BECOMES QUITE STRONG WITH 850 MB TEMPS TO AS HIGH AS 18-24C
MONDAY. THICKNESSES VALUES REACH 570 DM. THIS SHOULD DRIVE NE MT
HIGHS INTO THE UPPER 70S TO MID 80S...WHICH WILL APPROACH RECORD
HIGHS FOR THE DATE AT SOME LOCATIONS.
MODELS AGREE WITH A MOSTLY DRY...BUT FAIRLY STRONG COLD FRONT FROM THE
WNW MOVING ACROSS THE AREA TUE...WHICH WILL START A COOLING TREND.
THE ASSOCIATED UPPER TROUGH LAGS BEHIND...AND MODELS HAVE VARIED
ON TIMING...INTENSITY...AND MOVEMENT WITH THIS. ECMWF HAS BEEN
TOO QUICK TO BREAK DOWN THE RIDGE. MEANWHILE CMC GEM DEFLECTS BOTH
COLD FRONT AND TROUGH TO OUR N AND KEEPS THE RIDGE OVER OUR AREA...WHICH
DOES APPEAR POSSIBLE. GFS ENSEMBLES INDICATE THAT ANY OF THESE AND
OTHER SOLUTIONS ARE POSSIBLE TOO...SO LOW CONFIDENCE AT THE END OF
THE PERIOD. PREFER THE 00Z OPERATIONAL GFS THOUGH WHICH IS MORE
OF A MIDDLE GROUND SOLUTION...AND DOES BRING AT LEAST A SLIGHT
CHANCE OF SHOWERS BY WED. SIMONSEN
&&
.AVIATION...
THIS STORM SYSTEM ACROSS NORTHEAST MONTANA WILL BE SLOW- MOVING
THROUGH THURSDAY WITH RAIN SHOWERS IN THE AFTERNOON AND A STEADY
LIGHT RAIN OVERNIGHT. EXPECT SOME INTERMITTENT MVFR CEILINGS TO
IMPACT KGGW AND KOLF. IFR TO LIFR CEILINGS ARE MORE LIKELY FOR
KSDY AND KGDV TOWARD THE END OF THIS TAF CYCLE. EXPECT OCCASIONAL
TAF AMENDMENTS THURSDAY MORNING. A LIGHT TO BARELY BREEZY EAST
WIND WILL BE OF NO CONSEQUENCE. BMICKELSON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR FORT PECK
LAKE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS OMAHA/VALLEY NE
1258 PM CDT WED APR 18 2012
.UPDATE...
.AVIATION...
18Z TAFS FOR KOFK/KLNK/KOMA.
MAIN AVIATION CONCERNS ARE CONDITIONS DETERIORATING FROM VFR TO
MVFR THURS MORNING ASSOCIATED WITH STRENGTHENING SFC BNDRY OVER
ERN NEB. EXPECT SCT PCPN ACTIVITY ALL TERMINALS MAINLY BETWEEN
09Z-15Z TIME FRAME UNTIL SFC BNDRY SLIPS SOUTH. POST-FRONTAL MVFR
CIGS PREVAILING THEN THE REST OF THE FCST PD.
DEE
.PREV DISCUSSION... /ISSUED 302 AM CDT WED APR 18 2012/
MAIN FORECAST CONCERN WILL BE POPS IN THE NEAR TERM AS QUIET AND
WARMER WEATHER IS EXPECTED FOR THE WEEKEND INTO EARLY NEXT WEEK.
LATEST REGIONAL RADAR IMAGERY SHOWED BAND OF SHOWERS AND
THUNDERSTORMS PROGRESSING SOUTHEAST ACROSS THE NORTHERN PORTION
OF THE CWA. ACTIVITY IS ALONG A WEAK COLD FRONT OUT AHEAD OF A MID
LEVEL SHORTWAVE MOVING EWD THRU THE CENTRAL DAKOTAS. LATEST
SEVERAL RUNS OF THE HRRR HAVE HAD A GOOD HANDLE ON THIS LINE AND
EXPECT THE ACTIVITY TO EXIT THE SOUTHEASTERN FORECAST AREA AROUND
14Z.
WEAK FRONT WASHES OUT OVER THE AREA AND STRONG SOUTHERLY FLOW
RETURNS TONIGHT. ANOTHER WEAK SHORTWAVE WL MOVE THRU THE DAKOTAS
TONIGHT PUSHING A STRONGER COLD FRONT INTO THE FORECAST AREA
OVERNIGHT. THIS WILL BRING ANOTHER GOOD CHANCE FOR SCATTERED
SHOWERS AND THUNDERSTORMS OVERNIGHT AND INTO THURSDAY. THE FRONT
IS SLOW TO MOVE THRU AND LINGERS MUCH OF THE DAY THURSDAY UNTIL
STRONGER UPPER LEVEL SUPPORT ARRIVES THURSDAY NIGHT. CONTINUED
SMALL POPS IN OUR SOUTH LATE THURSDAY NIGHT INTO FRIDAY MORNING.
WARMING TREND ANTICIPATED FOR THE WEEKEND AND EARLY NEXT WEEK AS
AMPLIFIED UPPER RIDGE BUILDS OVER THE WESTERN CONUS. HIGHS IN THE
LOW 80S FORECAST BY TUESDAY.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1253 PM CDT WED APR 18 2012
.UPDATE...
AVIATION DISCUSSION UPDATED FOR 18Z TAF ISSUANCE.
SENDING OUT A QUICK UPDATE THIS MORNING SINCE IT`S CLOUDY
OUTSIDE...AND CURRENTLY AT LEAST 3 HOURS AWAY FROM SEEING ANY
SEMBLANCE OF CLEARING...PER RUC 925HPA RH PROGS. DID NOT ADJUST
HIGH TEMPERATURES DOWN YET...AS THERE IS STILL PLENTY OF TIME FOR
TEMPERATURE RECOVERY...CURRENTLY JUST 10 TO 15 DEGREES OFF
FORECAST HIGHS.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
THE WET WEATHER PATTERN WILL CONTINUE THROUGH AT LEAST THURSDAY
FOR THE NORTHERN PLAINS.
AS OF 8Z...AN AREA OF LOW PRESSURE IS LOCATED OVER WESTERN
MINNESOTA WITH LIGHT SHOWERS ONGOING ACROSS THE I-29 CORRIDOR. THESE
SHOWERS WILL PUSH EAST OF THE CWA BY 12Z WITH GENERALLY DRY
CONDITIONS EXPECTED FOR THE REST OF THE DAY PERIOD. WITH PARTLY TO
MOSTLY SUNNY SKIES...HIGH TEMPERATURES SHOULD WARM INTO THE 50S
AND 60S. HOWEVER BY TONIGHT...ANOTHER SHORTWAVE WILL BRING A
DECENT CHANCE FOR SHOWERS TO THE REGION. WITH LIMITED INSTABILITY
OR FORCING...WILL KEEP THE PCPN MENTION AS JUST RAIN SHOWERS.
RAINFALL AMOUNTS BETWEEN A QUARTER TO A HALF INCH COULD BE
POSSIBLE WITH THIS STORM SYSTEM.
PCPN CHANCES ON THURSDAY...ARE BEGINNING TO LOOK LIKELY THEN
BEFORE. LIGHT WRAP AROUND SHOWERS COULD BE POSSIBLE DURING THE
MORNING HOURS...ESPECIALLY IN THE EASTERN CWA. BY THE AFTERNOON
HOWEVER...MODELS SEEM TO DISAGREE WITH THE STRENGTH AND PLACEMENT
OF ANOTHER SHORTWAVE TROF. AT THIS TIME...IT SEEMS AS THOUGH THIS
WAVE IS TRENDING FURTHER NORTH WITH DRY CONDITIONS POSSIBLE IN THE
SOUTHERN CWA.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
OVERALL THE MODELS REMAIN CONSISTENT THROUGH THE LONG TERM.
SLOWING FLOW SHOULD RESULT IN MORE AMPLITUDE AT LEAST FOR A TIME
LATE THIS WEEKEND INTO EARLY NEXT WEEK AS HIGH PRESSURE ALOFT
BUILDS INTO THE PLAINS. BUT FIRST A DIGGING SYSTEM ON FRIDAY NIGHT
AND SATURDAY SHOULD BRING A FEW SHOWERS TO THE REGION. AFTER THAT
IT DRIES OUT UNTIL PERHAPS LATE IN THE PERIOD AS THE FLOW AGAIN
GETS FLATTENED BY PROGRESSIVE ENERGY COMING OFF THE PACIFIC AND
INTO THE WESTERN CONUS/WESTERN CANADA.
UNDERNEATH HIGH PRESSURE ALOFT...TEMPERATURES SHOULD FAVOR ABOVE
NORMAL THROUGH THE PERIOD.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
AREA OF MVFR CIGS CONTINUES TO SLIDE SOUTH OVER THE AREA. THESE
CLOUDS WILL SCATTER OUT AROUND MID-AFTERNOON. VSBYS WILL BE VFR.
SCT RAIN SHOWERS WILL MOVE FROM WEST TO EAST ACROSS THE REGION THIS
EVENING AND OVERNIGHT WITH MVFR/IFR CIGS RETURNING TO ALL TAF LOCATIONS AFTER
MIDNIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...SD
LONG TERM...TDK
AVIATION...CHURCH
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
100 PM CDT WED APR 18 2012
.UPDATE...MOST OF THE MORNING SHOWERS ACROSS SOUTHERN WISCONSIN
HAVE EITHER LIFTED NORTH OR WIPED OUT. STILL HOLDING ON TO A
CHANCE FOR SHOWERS AND STORMS THIS AFTERNOON AS THE WEAK SFC COLD
FRONT MOVES THOUGH. NOT VERY CONFIDENT IN THE CHANCE THOUGH...AS
LATEST WRF NMM...WRF ARW...AND HRRR ARE ALL SIGNIFICANTLY OVERDOING
THE CURRENT RADAR COVERAGE. SOUNDINGS ARE SHOWING A LOT OF DRY
AIR...WHICH MAY BE THE REASON THINGS ARE NOT FIRING ALONG THE
FRONT. STILL...SEEING SOME CAPE DEVELOPING WITH A DECENT AMOUNT OF
SUNSHINE...SO NOT GOING TO LET GO OF CHANE FOR FURTHER DEVELOPMENT
JUST YET. OTHERWISE...TEMPS GENERALLY ON TRACK FOR THIS AFTERNOON.
&&
.AVIATION/18Z TAFS/...STILL THINK THERE COULD BE A FEW SHOWERS AND
STORMS THAT DEVELOP AHEAD OF AN APPROACHING COLD FRONT THIS
AFTERNOON. THIS SYSTEM SEEMS TO BE DRIER THAN EXPECTED...SO
CONFIDENCE IN FURTHER PRECIP DEVELOPMENT IS NOT VERY HIGH.
THE FRONT WILL SAG SOUTH OF THE WISCONSIN THIS EVENING...STALLING
OVER NORTHERN ILLINOIS. THERE WILL BE LOW CHANCES FOR A SHOWER OR
STORM NEAR THE ILLINOIS BORDER TONIGHT...BEFORE A SHORTWAVE
RIDING THROUGH THE BAROCLINIC ZONE BRINGS WIDESPREAD RAIN TO
SOUTHERN WISCONSIN THURSDAY AND THURSDAY NIGHT.
EXPECT VFR CONDITIONS TO PREVAIL THROUGH TONIGHT...WITH
DETERIORATING CONDITIONS DURING THE DAY THURSDAY. CIGS WILL LIKELY
DROP TO MVFR TOMORROW...POSSIBLY IFR BY EVENING. SOME LOWER VSBYS
LIKELY TOO AT TIMES WITH THE HEAVIER PRECIP.
&&
.PREV DISCUSSION... /ISSUED 338 AM CDT WED APR 18 2012/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
MID LEVEL SHORTWAVE EXITING THE NORTHERN PLAINS WILL MOVE ACROSS
NORTHERN WISCONSIN AND THE LAKE SUPERIOR AREA TODAY. ASSOCIATED
UPPER LEVEL DIVERGENCE PUSHES ACROSS NORTHERN AND CENTRAL WISCONSIN
BY EARLY AFTERNOON. 850 MB LOW LEVEL JET OF ALMOST 60 KNOTS PUSHES
INTO NORTHEAST WISCONSIN BY 7AM CDT. FAIRLY STRONG MOISTURE
CONVERGENCE OF ALMOST 30 G/KG/12 HR OVER MAINLY NORTHEAST WISCONSIN
THIS MORNING WITH MUCH WEAKER VALUES AROUND 4 G/KG/12 HR ACROSS THE
SOUTH BY NOON. THIS RESULTS IN FAIRLY STRONG 700 MB UPWARD MOTION
OF 13 UBAR/SEC MAINLY ACROSS NORTHERN WISCONSIN WITH MUCH WEAKER
UPWARD MOTION OVER SOUTHERN WISCONSIN.
AS A RESULT EXPECT MOST OF THE SHOWERS/THUNDERSTORMS TO OCCUR TO THE
NORTH WITH THE WARM AIR ADVECTION THIS MORNING.
0-1 KM CAPE VALUES OF ALMOST 500M J/KG OCCUR THIS AFTERNOON ALONG
THE TRAILING COLD FRONT. THEREFORE EXPECT THE BEST CHANCE OF
THUNDERSTORMS TO BE THIS AFTERNOON WITH THE COLD FRONT. LOW LEVEL
LAPSE RATES ARE RATHER STEEP WITH VALUES AROUND 9.5 C/KM BELOW 800
MB. HOWEVER MID LEVEL LAPSE RATES ARE MARGINAL. 6 KM BULK SHEAR
VALUES RISE TO BETWEEN 40 AND 50 KNOTS LATER THIS AFTERNOON.
NEXT PROBLEM IS THAT THE FRONT STALLS OUT JUST SOUTH OF THE
WISCONSIN ILLINOIS BORDER TONIGHT...ALONG WITH LINGERING MOISTURE
AND MODEST ELEVATED CAPE AROUND 120 J/KG LIFTED FROM AROUND 5000 FT.
THEREFORE WILL CONTINUE A LOW CHANCE OF SHOWERS/THUNDERSTORMS FAR
SOUTH.
THURSDAY THROUGH FRIDAY...FORECAST CONFIDENCE IS HIGH.
ANOTHER POTENT SHORTWAVE IN THE TRAIN OF WAVES TRACKING ALONG THE
ZONAL 500MB FLOW WILL REACH WI THU MORNING. AT THIS TIME...500MB
FLOW WILL BEGIN TO DEVELOP A TROUGH IN THE CENTER OF THE
COUNTRY...AND THE 850MB BAROCLINIC ZONE WILL STRENGTHEN OVER CENTRAL
WI AND THE PRECIP AREA ASSOCIATED WITH THE VORTICITY ADVECTION AND
STRONG DYNAMIC FORCING WILL REMAIN STATIONARY ACROSS SOUTHERN WI ALL
DAY THU AND INTO THU NIGHT. THE MODELS KEEP PRECIP ACROSS SOUTHEAST
WI THROUGH FRI AFTERNOON UNTIL THE 500MB LOW CLOSES OFF OVER TEXAS
AND THE 850MB BAROCLINIC ZONE FINALLY SHIFTS SOUTHEAST OF WI. THE
SURFACE WARM FRONT MAY MAKE IT INTO FAR SOUTHERN WI BY 00Z FRI AND
THEN SHIFT BACK SOUTH AFTER 06Z FRI. THE ECMWF AND CANADIAN PUSH THE
WARM FRONT FURTHER NORTH THAN THE NAM AND GFS.
INGREDIENTS COME TOGETHER ON THU TO SUPPORT A PROLONGED PRECIP EVENT
OVER SOUTHERN WI ON THU...ESPECIALLY AROUND 18Z. STRONG SLOPED
FRONTOGENESIS...STRONG OMEGA FROM 925MB THROUGH 500MB...AND THE LOW
LEVEL JET NOSING INTO SOUTHERN WI...AS WELL AS STRONG UPPER LEVEL
DIVERGENCE IN THE RIGHT ENTRANCE REGION OF THE UPPER JET. THERE WILL
BE PLENTY OF MOISTURE FEEDING INTO THE REGION...WITH INTENSE
ISENTROPIC LIFT AND SPECIFIC HUMIDITY VALUES OF 6 TO 8 G/KG.
PRECIPITABLE WATER VALUES OVER AN INCH...WITH UP TO 1.22 INCHES PER
00Z NAM BY 00Z FRI. ECMWF AND CANADIAN HAVE THE HIGHEST QPF VALUES
ACROSS SOUTH CENTRAL AND EAST CENTRAL WI...TOTALING 1.5 INCHES OR
MORE. GFS AND NAM ARE MORE PROGRESSIVE WITH THE PRECIP AREA AND THUS
HAVE LOWER QPF TOTALS...AROUND 1 INCH OR LESS. ALL MODELS SHOW A
GOOD AMOUNT OF QPF OVER THE FORECAST AREA BETWEEN 18Z THU AND 00Z
FRI...BUT THE ECMWF AND CANADIAN MODELS KEEP PRODUCING HIGH QPF
AMOUNTS THROUGH 12Z FRI AND THEN BEGIN TO TAPER THEM OFF AFTER 18Z
FRI. HPC LEANED HEAVILY ON ECMWF AND CANADIAN QPF VALUES...BUT
FORECAST OFFICES IN THE WI AREA MODERATED THE VALUES DOWNWARD A BIT.
TOTAL RAINFALL AMOUNTS COULD BE ON THE ORDER OF 2 INCHES. HOWEVER
GIVEN THE LONG TIME FRAME OF WHEN IT FALLS...FLOODING DOES NOT
APPEAR TO BE A CONCERN. ISOLATED THUNDER STILL MENTIONED FOR THU
AFTERNOON DUE TO THE STRONG DYNAMICS OF THE SYSTEM. NO SEVERE
EXPECTED SINCE THERE IS VERY LITTLE CONVECTIVE INSTABILITY. STEADY
RAIN EVENT WITH A FEW HEAVIER SHOWERS EMBEDDED.
THERE IS GENERAL MODEL AGREEMENT FOR LINGERING RAIN SHOWERS ALL DAY
FRI DUE TO DEFORMATION ON THE NORTHWEST SIDE OF THE DEPARTING
LOW...AS WELL AS STEEP LOW LEVEL LAPSE RATES. A FEW SNOW FLAKES
COULD MIX INTO THE RAIN...ESPECIALLY TOWARD CENTRAL WI...BUT NO
ACCUMULATION ANTICIPATED. TEMPS WILL BE COOL ON FRI WITH BRISK NNE
WINDS OFF LAKE MICHIGAN.
LONG TERM...
FRIDAY NIGHT THROUGH WEDNESDAY...FORECAST CONFIDENCES IS MEDIUM.
SURFACE HIGH PRESSURE SETTLING INTO THE UPPER MIDWEST WILL KEEP
QUIET AND SEASONABLY COOL WEATHER ACROSS SOUTHERN WI FOR THE
WEEKEND. BRIEF PERIOD OF CLEAR SKIES EXPECTED IN THE WAKE OF THE
DEPARTING LOW. THEN A 500MB SHORTWAVE WILL MOVE ACROSS NORTHERN MN
AND WI IN THE NORTHWEST FLOW AND BRING CLOUDS AND A SLIGHT CHANCE
FOR SHOWERS ON SUNDAY.
NEXT CHANCE FOR PRECIP WILL BE WITH A WARM FRONT AND POTENT
SHORTWAVE APPROACHING THE GREAT LAKES REGION ON TUE THROUGH WED.
THUNDER POSSIBLE WITH THIS SYSTEM.
AVIATION/12Z TAFS/...
SURFACE LOW WILL TRACK ACROSS THE LAKE SUPERIOR REGION THIS
AFTERNOON. EXPECT VFR CIGS IN THE WARM AIR ADVECTION WITH A 50 KNOT
850 MB LOW LEVEL JET WITH MUCH OF THE SHOWERS/THUNDERSTORMS OVER
CENTRAL AND NORTHERN WISCONSIN THIS MORNING.
EXPECT A CHANCE OF THUNDERSTORMS OVER THE FORECAST AREA THIS
AFTERNOON AS A TRAILING COLD FRONT MOVES ACROSS SOUTHERN WISCONSIN.
MAINLY VFR CIGS WITH CUMULUS BUT MVFR CIGS AND BRIEF IFR VSBYS
CERTAINLY POSSIBLE WITHIN THUNDERSTORMS.
THE FRONT WILL STALL JUST SOUTH OF THE ILLINOIS BORDER TONIGHT.
MAINLY VFR CIGS BUT SOME MVFR CIGS POSSIBLE ALONG THE FRONT.
MARINE...
SOUTH TO SOUTHWEST WINDS WILL GUST TO 25 TO 30 KNOTS ALONG THE SHORE
AHEAD OF AN APPROACHING COLD FRONT TODAY. HOWEVER WITH THE COLD
WATERS MORE OF AN INVERSION IS EXPECTED TOWARD OPEN WATERS...SO
WINDS MAY BE LESS THERE. A SMALL CRAFT ADVISORY IS IN EFFECT.
THE COLD FRONT WILL STALL ACROSS FAR NORTHERN ILLINOIS TONIGHT WITH
NORTHEAST WINDS LATER TONIGHT. HOWEVER WINDS WILL BE DIMINISHING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ643>646.
&&
$$
UPDATE...DDV
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
THURSDAY THROUGH TUESDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1237 PM CDT WED APR 18 2012
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
710 AM CDT WED APR 18 2012
UPDATE...HAVE UPDATED THE FORECAST IN REGARD TO THE RAIN SHOWERS
CURRENTLY MOVING ACROSS THE REGION. MUCH OF THE LOW LEVEL MOISTURE
ADVECTION HAS BROUGHT THESE SHOWERS OUT AHEAD OF THE COLD FRONT
WITH MUCH OF THIS SHOWER ACTIVITY INTO CENTRAL WISCONSIN BY LATER
THIS MORNING. SKIES ARE ALSO CLEARING OUT ACROSS MINNESOTA...SO
HAVE GONE WITH A MUCH FASTER END TO THE RAIN THIS
MORNING/AFTERNOON ALONG WITH THE CLOUD TRENDS. HAVE HELD ONTO A
SMALL CHANCE FOR RAIN SHOWERS LATE THIS AFTERNOON FROM SOUTHWEST
WISCONSIN INTO NORTHEAST IOWA FOR THE OFF CHANCE THAT SOME SHOWERS
COULD DEVELOP ALONG THE STALLING OUT FRONT...WHICH IS WHAT THE
PAST FEW RUNS OF THE HRRR HAVE SHOWN. CONFIDENCE IN THOSE SHOWERS
ACTUALLY DEVELOPING AT THIS POINT ARE VERY LOW THOUGH GIVEN THE
ADVANCEMENT OF THIS MORNINGS CONVECTION.
PREVIOUS SHORT TERM AFD...
FIRST CONCERN WILL BE SHOWERS/THUNDERSTORMS TODAY...THEN RAIN AGAIN
THURSDAY INTO THURSDAY NIGHT WITH PERHAPS SOME SNOW MIXING IN
THURSDAY NIGHT. LOOK FOR A CHANCE OF LINGERING RAIN/SHOWERS ON
FRIDAY AS WELL.
CURRENT WATER VAPOR IMAGERY SHOWING A RATHER DYNAMIC MID-LEVEL WAVE
PUSHING INTO WESTERN MN. AT THE SURFACE...LOW PRESSURE WAS LOCATED
OVER SOUTHWEST MN WITH WARM AIR ADVECTION/STRONG ISENTROPIC LIFT AND
MOISTURE TRANSPORT PRODUCING SCATTERED SHRA/TS ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY REGION. SO FAR MOST OF THIS ACTIVITY HAS
BEEN CONFINED ALONG/NORTH OF I-90. MEANWHILE...THE COLD FRONT FROM
THE LOW WAS PRODUCING A DECENT LINE OF THUNDERSTORMS FROM SOUTHWEST
MN INTO NORTHEAST NEB. OTHERWISE...UNDER MOSTLY CLOUDY
SKIES...TEMPERATURES AT 3 AM ACROSS THE AREA WERE IN THE MID 40S TO
MID 50S.
FOR TODAY...WILL BE WATCHING THAT LOW AND COLD FRONT TRACK EAST
ACROSS THE AREA AS THE NAM HAS 0-3KM MUCAPE INCREASING INTO THE
800-1100 J/KG RANGE THIS MORNING AND AFTERNOON. THERE IS ALSO AMPLE
SHEAR PRESENT IN THIS LAYER IN THE 35-40KT RANGE. BUFKIT ALSO
SHOWING MOST OF THIS ACTIVITY FAIRLY HIGH BASED. SO...THINKING THERE
MAY BE AN OUTSIDE CHANCE OF SOME SUB-SEVERE HAIL/WIND WITH A FEW OF
THESE STORMS. HIGHEST THREAT AREA FOR THIS OCCURRING LOOKS TO BE
SOUTHEAST OF A LINE FROM NEAR SPARTA AND VIROQUA WI...TO NEAR
OELWEIN IA. OTHERWISE...LOOK FOR GUSTY SOUTHWEST WINDS THIS MORNING
IN THE 15-30 MPH RANGE SHIFT TO THE WEST/NORTHWEST THIS AFTERNOON
WITH HIGHS TOPPING OFF WELL INTO THE 60S.
FOR TONIGHT...WILL SEE CLEARING EARLY IN THE EVENING WITH THE COLD
FRONT SLIDING SOUTHEAST OF THE AREA AND THEN STALLING OUT ACROSS NORTHERN
IL INTO CENTRAL IA. WEAK CYCLOGENESIS OVER THE CENTRAL PLAINS WILL
THEN PRODUCE ISENTROPIC LIFT/MOISTURE TRANSPORT ACROSS THIS FRONTAL
BOUNDARY FOR INCREASING CLOUDS AGAIN AFTER MIDNIGHT. ANY RAIN LOOKS
LIKE IT WILL HOLD OFF SOUTH/WEST OF THE AREA. INCREASING ISENTROPIC
LIFT/MOISTURE TRANSPORT AHEAD OF THE THE WEAK WAVE OF LOW PRESSURE
OVER THE PLAINS SPREADS RAIN INTO THE AREA ON THURSDAY. NAM STILL
SHOWING SOME WEAK ELEVATED CAPE IN THE 850-700MB LAYER FOR PERHAPS
AN ISOLATED CLAP OR TWO OF THUNDER EMBEDDED IN THE RAIN SHIELD.
OTHERWISE...EASTERLY FLOW AND RAIN WILL MAKE FOR A RATHER RAW DAY
WITH HIGHS STRUGGLING INTO THE UPPER 40S TO MIDDLE 50S.
THE WAVE OF LOW PRESSURE MOVES ACROSS NORTHERN IL THURSDAY
NIGHT..DRAGGING COOLER AIR IN ACROSS THE REGION. THIS IS EXPECTED TO
PRODUCE A COOLING DEFORMATION AREA WITH A PERHAPS A MIX OF A
RAIN/SNOW ACROSS PORTIONS OF THE AREA LATE IN THE NIGHT. NO SNOW
ACCUMULATION IS EXPECTED THOUGH.
ON FRIDAY...THE LOW TRACK EAST INTO THE EASTERN GREAT LAKES REGION
WITH PERHAPS SOME LINGERING DEFORMATION PRECIPITATION IN THE
MORNING. MEANWHILE...THE COOL/RATHER DEEP MID-LEVEL TROUGH TRACKS
OVER OUR AREA DURING THE DAY. THE NAM QPF AND NAM BUFKIT HINTS AT
SOME SHOWER ACTIVITY UNDER THIS COLDER/CYCLONIC FLOW ALOFT. HELD
ONTO SOME LOWER-END 20-40 POPS TO HONOR THIS SIGNAL. LOOK FOR
CHILLIER THAN NORMAL HIGHS IN THE UPPER 40S TO LOWER 50S AS WELL.
CLEARING THEN EXPECTED FRIDAY NIGHT AS A WEAK RIDGE OF HIGH PRESSURE
DRIFTS ACROSS THE REGION WITH LOWS DIPPING INTO THE UPPER 20S TO
LOWER 30S. WILL HAVE TO KEEP THIS IN MIND FOR POSSIBLE FROST/FREEZE
HEADLINES.
.LONG TERM...SATURDAY THROUGH TUESDAY
330 AM CDT WED APR 18 2012
18.00Z GFS AND ECMWF IN PRETTY GOOD AGREEMENT THROUGH THE LONG TERM.
BOTH MODELS HAVE SATURDAY DRY WITH SURFACE RIDGE HOLDING ACROSS THE
AREA. TEMPERATURES STILL A BIT ON THE COOL SIDE THE THOUGH WITH
HIGHS IN THE LOW-MID 50S. WARM AIR ADVECTION AHEAD OF A WEAK
MID-LEVEL WAVE IN THE NORTHWEST FLOW ALOFT WILL INCREASE CLOUDS AND
PRODUCE A CHANCE OF -SHRA SATURDAY NIGHT. THIS WILL BE MAINLY
NORTHWEST OF A MEDFORD THROUGH WINONA AND DODGE CENTER LINE. THIS
WAVE WILL THEN PRODUCE A CHANCE OF SHRA THROUGH SATURDAY MAINLY EAST
OF THE MISSISSIPPI RIVER. SUNDAY NIGHT THROUGH MONDAY WILL SEE WARM
AIR ADVECTION ACROSS THE AREA WITH HIGHS MONDAY INCREASING INTO THE
UPPER 50S TO MIDDLE 60S. MODELS THEN SHOW A BIT MORE VIGOROUS
MID-LEVEL/SURFACE LOW PUSHING ACROSS SOUTHERN CANADA AND THE
NORTHERN PLAINS...TOWARD THE AREA MONDAY NIGHT THROUGH TUESDAY FOR A
CHANCE OF SHOWERS AND THUNDERSTORMS. LOOK FOR HIGHS ON TUESDAY WELL
INTO THE 60S.
&&
.AVIATION...THROUGH 18Z THURSDAY
1236 PM CDT WED APR 18 2012
GUSTY WINDS WILL CONTINUE THROUGH SUNDOWN THIS EVENING. GUST SPEED
BEHAVIOR WILL BE ERRATIC OVER TIME THIS AFTERNOON WITH MUCH OF IT
DEPENDENT ON MIXING DEPTH. THE DIRECTION SHOULD BE MORE RELIABLE.
A COLD RAIN SYSTEM MOVES IN FOR LATE TONIGHT AND THURSDAY. IFR
CONDITIONS /OR VERY LOW MVFR/ ARE EXPECTED BY AFTERNOON JUST
BEYOND THE TAF TIME AT BOTH SITES IN A MODERATE RAIN. CLOUDS AND
VSBYS WILL SLOWLY LOWER THROUGH THE MORNING INTO THE AFTERNOON.
CONFIDENCE ON THIS WEATHER SYSTEM IS PRETTY HIGH. THERE MAY ALSO
BE EMBEDDED THUNDER WITHIN THE RAIN SHIELD ALTHOUGH THIS WAS NOT
INCLUDED IN THE TAFS AT THIS TIME. WOULD EXPECT A LARGE
PRECIPITATION SHIELD OVER THE REGION THURSDAY WITH THIS WEATHER
SYSTEM TRACKING EAST TO WEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
330 AM CDT WED APR 18 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM.... DAS
AVIATION...BAUMGARDT