Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 03/12/12
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1032 AM MST SAT MAR 10 2012
.UPDATE...
ISSUED AT 1031 AM MST SAT MAR 10 2012
THE NRN FRINGE OF THE CLOUD MASS ASSOCIATED WITH THE CLOSED LOW
CIRCULATION CENTERED OVER SWRN NEW MEXICO REACHES THE SRN COLORADO
BORDER. THE CLOSED LOW IS BEGINNING TO EJECT NORTHEAST...BUT ENERGY
ROTATING AROUND THE UPPER CIRCULATION NICKS THE ERN SAN JUAN
MOUNTAINS IN RETURN FLOW. THE HIGHER RESOLUTION MODELS INDICATE
THAT SHOWERS WILL FORM OVER LA PLATA AND ARCHULETA
COUNTIES...POSSIBLY EXTEND AS FAR WEST AS MESA VERDE NATIONAL
PARK. THE HRRR MODEL HAS BEEN DRY BUT AS BEEN TRENDING TOWARDS AN
INCREASE OF SHOWERS THIS AFTERNOON INTO EARLY EVENING. AR OF
17Z...MUCH OF THIS AREA IS CLEAR BUT MOST OF NWRN NEW MEXICO
INCLUDING FARMINGTON IS CLOUDY. HAVE BOOSTED POPS INTO THE CHANCE
CATEGORY FOR THIS AREA...BUT DRIER WITH ISOLATED FLURRIES FOR THE
NWRN SAN JUANS.
FOR THE REMAINDER OF THE FORECAST AREA...SUNNY CONDITIONS
PREVAILS WITH ABOVE TEMPS ABOVE SEASONAL VALUES.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 332 AM MST SAT MAR 10 2012
DURING THE LAST 24 HOURS...THE CLOSED UPPER LOW HAS ROTATED FROM
SOUTH-CENTRAL NM TO SOUTHEAST AZ. IT WILL CONTINUE ITS COUNTER-
CLOCKWISE ROTATION BACK INTO SOUTHWEST NEW MEXICO LATE THIS
MORNING. THE LOW WILL THEN SWING OVER LAS CRUCES THIS AFTERNOON
BEFORE EJECTING NORTHEAST TONIGHT WITH THE LOW CENTER REACHING
THE WESTERN OK PANHANDLE BY AROUND SUNRISE SUNDAY. MOISTURE
ROTATING AROUND THE LOW HAS INCREASED OVER OUR SOUTHERN EDGE EARLY
THIS MORNING...ESPECIALLY OVER THE SOUTHEAST CORNER. EXPECT CLOUDS
TO CONTINUE OVER THE SOUTHEAST CORNER THROUGH THE DAY...AND EVEN
INTO THIS EVENING AS THE LOW SHIFTS EAST...THEN NORTHEAST...
KEEPING THAT SECTOR OF OUR FORECAST AREA THE CLOSEST IN PROXIMITY.
THE FLOW...SOUTHEAST INITIALLY...THEN BECOMING NORTHEAST LATE THIS
EVENING...IS NOT ALL THAT FAVORABLE FOR OUR SIDE OF THE SAN JUANS.
BUT A FEW SHOWERS WILL BE POSSIBLE THROUGH THIS EVENING DUE TO THE
INCREASED MOISTURE AND INSTABILITY AS THE LOW EJECTS. ALSO EXPECT
SOME CLOUDS TO SPREAD NORTHWARD ALONG THE DIVIDE DURING THE
AFTERNOON IN THE WRAP AROUND FLOW.
THE BULK OF THE FORECAST AREA WILL BE SUNNY TO MOSTLY SUNNY.
TEMPERATURES WILL BE SIMILAR TO YESTERDAY...WITH POSSIBLY A LITTLE
COOLING OVER THE SOUTHEAST EDGE DUE TO MORE CLOUDS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 332 AM MST SAT MAR 10 2012
BY SUNDAY EVENING THE CLOSED LOW SHOULD BE OVER KANSAS AND
NEBRASKA WITH HIGH PRESSURE AND DRY CONDITIONS OVER ALL OF EASTERN
UT AND WESTERN CO. MONDAY AND TUESDAY...THE FORECAST AREA WILL
REMAIN BENEATH THE WESTERN PORTION OF A BIG RIDGE THAT WILL COVER
MUCH OF THE CENTRAL AND EASTERN U.S. THE NEXT PACIFIC TROUGH WILL
BE POUNDING THE WEST COAST NORTH OF SAN FRANCISCO FOR THE REST OF
THE WEEK. THIS TROUGH DEEPENS ALONG THE WEST COAST THROUGH
THURSDAY AND CONTINUOUSLY BUILDS THE RIDGE OVER THE CENTRAL U.S.
FRIDAY NIGHT A MAJOR PORTION OF THIS TROUGH IS PROJECTED TO MOVE
INLAND...REACHING THE GREAT BASIN FRIDAY NIGHT. THE GFS SHOWS SOME
SUBTROPICAL MOISTURE BEING TAPPED BY THE SSW FLOW AHEAD OF THIS
TROUGH AND CARRIED NORTH INTO CO AND EASTERN UT. THE ECMWF DOES
NOT SHOW THIS MOISTURE TAP. THE TWO MODELS DIFFER IN THE CHARACTER
OF THIS SYSTEM AS IT APPROACHES. THE GFS PRODUCES A BROADER TROUGH
WITH MORE SHORTWAVES EJECTING THROUGH IT. THE ECMWF SHOWS MORE OF
A SINGLE LARGE...LONGITUDINAL TROUGH MOVING BODILY THROUGH THE
WESTERN U.S. KEEPING TO THE ASPECTS THE MODELS HAVE IN COMMON...
HAVE INCREASED THE CHANCE OF PRECIP FRI OVER EASTERN UT AND EXTREME
WESTERN CO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1031 AM MST SAT MAR 10 2012
VFR AT ALL TAF SITES AND AIRFIELDS THROUGH TONIGHT. FOR KDRO AND
KPSO...A PASSING SHOWER MAY TEMPORARILY LOWER CIGS BKN025. FOR THE
SAN JUAN MOUNTAIN PASSES...EXPECT TERRAIN TO BE OCCASIONALLY
OBSCURED FROM AREAS OF SNOW. IMPROVING CONDITIONS WITH DISSIPATING
CIGS ARE EXPECTED AFTER 06Z TONIGHT.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...EH
LONG TERM....CC
AVIATION...PF
AREA FORECAST DISCUSSION
NWS BOISE ID
841 MDT SUN MAR 11 2012
.DISCUSSION...COLD FRONT...WHICH MARKED A PERIOD OF GUSTY WINDS AS
IT MARCHED THROUGH THE VALLEY...HAS MOVED OFF TO THE EAST THIS
EVENING. WINDS HAVE BEEN DIMINISHING WITH GUSTS ENDING OR WEAKENING
WELL BELOW ADVISORY THRESHOLDS. SHOWERS HAVE BEEN STEADILY
INCREASING IN COVERAGE OVER THE PAST HOUR WITH A SW-NE ORIENTED BAND
OF SHOWERS SETTING UP FROM SOUTHERN MALHEUR COUNTY EXTENDING ACROSS
THE TREASURE VALLEY AND INTO THE BOISE/WEST CENTRAL MTNS. SNOW HAS
STARTED TO FALL ONCE AGAIN IN MCCALL WHERE AN INCH OR TWO OF NEW
SNOWFALL IS EXPECTED OVERNIGHT. MODELS ARE TRENDING DRIER AFTER
MIDNIGHT AS THE UPPER LEVEL SUPPORT DRIVING THE SHOWERS LIFTS
NORTHWARD. NEXT SYSTEM AMPLIFIES OFFSHORE AS THE LOW-MID LEVEL S-SW
FLOW INCREASES WITH GUSTY WINDS RETURNING MONDAY AFTERNOON. WINDS
MAY BE STRONG ENOUGH IN PORTIONS OF SE OREGON TO WARRANT A WIND
ADVISORY. MOST OF THE AREA REMAINS DRY ON MONDAY BUT SHOWERS WILL BE
POSSIBLE ACROSS THE FAR NORTH. FORECAST UPDATE WILL INCLUDE REMOVING
THUNDERSTORMS AND RAISING POPS FOR THE REMAINDER OF THIS EVENING.
&&
.AVIATION...VFR IN THE VALLEYS THROUGH MONDAY. SNOW AND LOW CEILINGS
WILL OBSCURE TERRAIN IN SW IDAHO MTNS TONIGHT WITH MVFR CEILINGS
LIKELY NOT SCATTERING OUT UNTIL NOON ON MONDAY. SW WINDS ALOFT TO 30
KTS WILL CONTINUE THROUGH MONDAY. SURFACE WINDS WILL GRADUALLY SHIFT
TO THE EAST AND SOUTH TONIGHT INCREASING IN SPEED ACROSS SE OREGON
ON MONDAY.
&&
.PREV DISCUSSION...
SHORT TERM...TONIGHT THROUGH TUESDAY...COLD FRONT WITH ISOLATED
THUNDERSTORMS EXTENDED FROM AROUND DONNELLY TO JORDAN VALLEY AT 230
PM. EXPOSED FLAGSTAFF HILL RAWS GUSTED TO 64 MPH AS A THUNDERSTORM
CROSSED IT. A SPOTTER NEAR INDIAN VALLEY ESTIMATED WIND GUSTS OF
50-60 MPH AS A SEPARATE THUNDERSTORM DEVELOPED THERE...THEN WEAKENED
AS IT MOVED TOWARDS THE LONG VALLEY. GUSTY SW WINDS TO AROUND 50 MPH
WERE REPORTED ACROSS A WIDE AREA WITH AND BEHIND THE FRONT
ESPECIALLY OVER HARNEY AND MALHEUR COUNTIES. GUSTY WINDS WILL
PROGRESS THROUGH SW IDAHO THEN DROP OFF AFTER SUNSET AS A SURFACE
HIGH PRESSURE RIDGE WITH WEAK GRADIENT CROSSES SE OREGON AND SW
IDAHO OVERNIGHT. SATELLITE GOES LI WERE NEGATIVE IS SPOTS NORTH
THROUGH WEST OF BOISE AS OF 2 PM AND THE RUC MODELED CAPE EXCEEDED
200 J/KG IN EAST CENTRAL OREGON INCLUDING MUCH OF BAKER COUNTY AT
18Z/NOON MDT. THE NEXT SYSTEM WILL AMPLIFY DRAMATICALLY OFFSHORE
BRINGING A ROUND OF SHOWERS AND GUSTY STRONG SOUTH WINDS TO OREGON
AND CLOUDS WITH LOW POPS AND LESS STRONG EAST TO SE WINDS OVER
IDAHO. THIS NEXT FRONT MOVES THROUGH SW IDAHO MONDAY NIGHT AND
TUESDAY MORNING. TIMING CHANGES ARE POSSIBLE AS THE SYSTEM IS SO
AMPLIFIED.
LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...A MOIST SOUTHWEST FLOW
ALOFT WILL HOLD TEMPERATURES 5 TO 8 DEGREES ABOVE NORMAL THROUGH
THURSDAY NIGHT. THERE WILL BE PRECIPITATION THROUGH THE PERIOD...
WITH THE BEST CHANCES TUESDAY NIGHT AND AGAIN THURSDAY NIGHT AND
FRIDAY. SNOW LEVELS WILL BE MAINLY ABOVE 5000 FEET TUESDAY NIGHT
RISING TO OVER 7000 FEET THURSDAY NIGHT. ON FRIDAY A COLD FRONT WILL
CROSS OUR AREA FOLLOWED BY MUCH COOLER WEATHER FOR THE WEEKEND AS A
MAJOR UPPER LEVEL TROUGH DEEPENS OVER THE WESTERN U.S. MAX
TEMPERATURES SATURDAY AND SUNDAY WILL BE 5 TO 10 DEGREES BELOW
NORMAL...WITH MINS RETURNING TO NEAR NORMAL FOR FRIDAY NIGHT AND
SATURDAY NIGHT. SHOWERS WILL BE SCATTERED...IN THE FORM OF SNOW OVER
THE MOUNTAINS AND A MIX OF SNOW AND RAIN IN THE VALLEYS.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...BW
AVIATION.....DG
PREV SHORT TERM...VM
PREV LONG TERM....JT/WH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
828 PM CDT SUN MAR 11 2012
...UPDATE TO REDUCE PRECIPITATION CHANCES AND QPF...
.UPDATE...
ISSUED AT 821 PM CDT SUN MAR 11 2012
THE UPPER LEVEL LOW WAS PULLING OUT FASTER THAN PREVIOUSLY
THOUGHT, AS WAS THE LOW LEVEL PRESSURE SYSTEM. A FEW SHOWERS MAY
MOVE THROUGH THE NORTHEASTERN SIDE OF OUR CWA IN THE WRAPAROUND,
BUT THESE SHOULD BE FAR AND FEW BETWEEN, AND VERY LIGHT IN
PRECIPITATION AMOUNTS. WILL ONLY LEAVE PRECIP CHANCES IN THE
NORTHEAST FOR A FEW HOURS, THEN DIMINISH THEM ALL TOGETHER. I
REDUCED QPF TO .01-INCH. THE REST OF FORECAST WILL REMAIN THE
SAME.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 323 PM CDT SUN MAR 11 2012
SYNOPSIS:
ON THE SYNOPTIC SCALE...A SLOW MOVING UPPER LEVEL LOW WAS CENTERED
OVER SOUTHWEST KANSAS DURING THE MID AFTERNOON HOURS. THE RUC MODEL
WAS ANALYZING A -26C COLD CENTER AT 500MB AT THE CENTER OF THE
LOW...AND AROUND -8C AT 700MB. LOW LEVEL MOISTURE HAD WRAPPED ALL
AROUND THE LOW CENTER WHICH PREVENTED THE EROSION OF LOW STRATUS
CLOUDS...KEEPING SURFACE TEMPERATURES IN THE LOWER TO MID 40S
THROUGH THE MID AFTERNOON HOURS. THE HIGH RESOLUTION SHORT TERM
HRRR AND RUC MODELS DID AN EXCELLENT JOB WITH THE TEMPERATURES
TODAY...WITH THE NAM12 PERFORMING POORLY AS IT WAS WARMING THE
SURFACE TOO MUCH WITH CLOUDS ERODING. AS A RESULT...SURFACE-BASED
INSTABILITY DID NOT DEVELOP...AND A MORE STRATIFIED AREA OF RAIN WAS
THE RESULT ACROSS THE SOUTHERN/CENTRAL SECTIONS OF THE DDC FORECAST
AREA.
FORECAST:
WILL BE CARRYING LIKELY TO CATEGORICAL POPS THROUGH THE EARLY
EVENING HOURS ACROSS CENTRAL AND EASTERN SECTIONS OF THE FORECAST
AREA WITH DRYING BEGINNING IN THE WAKE OF THE LOW OVER THE WESTERN
COUNTIES EARLY THIS EVENING. CLEARING IS ACTUALLY STARTING TO TAKE
SHAPE OVER EXTREME SOUTHEAST COLORADO BEHIND THE LOW...AND THIS WILL
ONLY EXPAND EAST INTO SOUTHWEST KANSAS THROUGH THE EVENING. THERE
WILL NOT BE ANY COLD AIR ADVECTION BEHIND THIS LOW WITH TEMPERATURES
ACTUALLY QUITE A BIT WARMER OUTSIDE OF THE LOW AREA (NORTH, WEST,
AND SOUTH). AS FAR AS LOW TEMPERATURES ARE CONCERNED TONIGHT...HAVE
DROPPED THE LOWS A FEW DEGREES OUT WEST GIVEN THE TIMING OF CLOUD
EROSION AND THE ALREADY COOL START TO THE EVENING. RADIATIONAL
COOLING, EVEN WITH 10 KNOTS OF WIND FROM THE WEST, SHOULD DROP
TEMPERATURES DOWN INTO THE LOWER 30S PROBABLY BY MIDNIGHT...THEN
BEGIN TO STABILIZE DURING MUCH OF THE REST OF THE OVERNIGHT HOURS AS
WINDS AVERAGE 10 TO 12 KNOTS FROM THE WEST-SOUTHWEST.
TOMORROW WILL BE A VERY PLEASANT DAY AS HEIGHTS RISE WITH THE
DEPARTURE OF THE LOW NORTHEAST. 850-700MB TEMPERATURES WILL BE
WARMING SUBSTANTIALLY TONIGHT WHICH WILL SET THE STAGE FOR
TEMPERATURES TO RISE RAPIDLY AFTER SUNRISE TOMORROW. IN FACT BY
NOON TOMORROW...TEMPERATURES WILL PROBABLY ALREADY BE WELL INTO THE
MID TO UPPER 60S. HAVE NOT REALLY CHANGED THE PREVIOUS FORECAST AT
ALL REGARDING HIGHS TOMORROW...WITH WIDESPREAD MID TO PERHAPS UPPER
70S EXPECTED. THE LACK OF AN APPRECIABLE PRESSURE GRADIENT/LEESIDE
TROUGH WILL YIELD LIGHT WINDS...LIKELY LESS THAN 10 KNOTS ALL DAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 323 PM CDT SUN MAR 11 2012
THE THEME FOR THE EXTENDED PERIOD IS WARM TEMPS (WELL ABOVE NORMAL
TEMPERATURES...20 TO 30 DEGREES ABOVE NORMAL) AND SOME SMALL CHANCES
FOR THUNDERSTORMS LATE IN THE PERIOD.
FOR TUESDAY, THE LEE SURFACE TROUGH WILL STRENGTHEN WITH SW 20 TO 30
KT OF WIND DEVELOPING AT 850 HPA AND AROUND 15 TO 20 MPH
SOUTHWESTERLY DOWNSLOPE WINDS EXPECTED AT THE SFC. THIS WILL RESULT
IN A WELL MIXED ATMOSPHERE WITH RESULTANT GUSTY SOUTHWESTERLY WINDS.
MIXING FROM FORECAST SOUNDINGS IS EXPECTED TO ABOUT 700 HPA. MIX
DOWN TEMPERATURES SUPPORT LOW TO MID 80S DEG F ACROSS MUCH OF SW
KANSAS. DEWPOINTS WILL MIX DOWN TO LOW 20S DEG F TO POSSIBLY UPPER
TEENS DEG F WHICH WILL RESULT IN RH`S CRASHING DOWN TO 10 TO 15
PERCENT. AS A RESULT OF THE AFOREMENTIONED CONCERNS, HAVE ISSUED A
FIRE WEATHER WATCH (RFW) FOR TUESDAY AFTERNOON FOR FAR WESTERN
KANSAS.
BEYOND TUESDAY, A BROAD UPPER AND LOW LEVEL RIDGE ACROSS THE
SOUTHEAST ALONG WITH CONTINUED LEE SURFACE TROUGHING WILL RESULT IN
RETURN FLOW ACROSS THE SOUTHERN/CENTRAL PLAINS. THE DRYLINE SHOULD
BEGIN TO SHARPEN WEDNESDAY WITH UPPER 50S DEG F DEWPOINTS SOUTH OF
THE DRYLINE LOCATED ACROSS SOUTH CENTRAL/SE KANSAS. THE INCREASING
DEWPOINTS WILL LEAD TO MILD LOWS TOWARDS KP28 THROUGH THE REST OF
THE PD.
THE DRYLINE WILL EVENTUALLY MIX WESTWARD AS UPPER LEVEL FLOW BECOMES
MORE MERIDIONAL. THE EXACT DRYLINE POSITION FOR ANY GIVEN DAY IS
UNCERTAIN AT THIS POINT, HOWEVER...THE GENERAL TREND IN THE MODELS
IS TO MIX THE DRYLINE WESTWARD THROUGH THE END OF NEXT WEEK.
THE DRYLINE IN COMBINATION WITH WEAK IMPULSES EMBEDDED IN THE FLOW
ALOFT COULD LEAD TO SOME ISOLATED CONVECTION BEGINNING THURSDAY AND
CONTINUING THROUGH THE WEEKEND. DID NOT DEVIATE FROM THE ALLBLEND
APPROACH AS CONFIDENCE IN STORM INITIATION IS LOW AT THIS POINT. THE
BEST LOCATION FOR SEEING THUNDERSTORM ACTIVITY WILL BE ACROSS SOUTH
CENTRAL KANSAS WHERE BETTER BOUNDARY LAYER MOISTURE/HIGHER CAPE
VALUES IS EXPECTED. CAPPING COULD BE A CONCERN, PARTICULARLY IF YOU
BUY THE WARMER AND DRIER ECMWF.
LOOKING AT WEEK TWO, THE MODELS CONTINUE TO STRUGGLE WITH TIMING OF
THE EJECTION OF THE UPPER LEVEL TROUGH. BY MARCH 19TH, UL FLOW
BECOMES STRONGER AND MORE SOUTHERLY. CAPE VALUES FROM THE ECMWF SHOW
AROUND 2000 J/KG AND 0 TO 6 KM SHEAR INCREASES TO AROUND 50 KT. AT
SOME POINT SEVERE WEATHER COULD BE A SIGNIFICANT CONCERN...
PARTICULARLY AS THE UPPER LEVEL WAVE FINALLY EJECTS OUT ACROSS THE
PLAINS.
&&
.AVIATION...(FOR 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 618 PM CDT SUN MAR 11 2012
MVFR CIGS WILL BE SHORT LIVED AS BOTH A SURFACE LOW AND UPPER
LEVEL LOW PRESSURE SYSTEM MOVES SLOWLY EAST FROM WESTERN KANSAS.
BY 02Z, VFR CIGS WITH JUST A FEW STRATOCU CLOUDS WILL BE LEFT AT
KDDC AND KGCK. KHYS WILL LINGER A BIT LONGER IN THE MVFR CIGS
AROUND OVC023, BUT BREAK OUT BY 04Z. ALSO, KHYS WILL STILL SEE
SOME RAIN SHOWERS THOUGH 04Z, BUT THE RAIN HAS ENDED IN THE WEST.
&&
.FIRE WEATHER...
ISSUED AT 403 AM CDT SUN MAR 11 2012
RED FLAG WARNING CRITERIA MAY BE MET TUESDAY BEHIND THE SURFACE DRYLINE
ALONG AND WEST OF A LINE FROM DIGHTON TO GARDEN CITY TO LIBERAL.
MID-LEVEL MOMENTUM IS EXPECTED TO EASILY MIX TO THE SURFACE DURING
THE AFTERNOON WITH WIND GUSTS AS HIGH AS 25-30 KTS FOR A FEW
HOURS, ALONG WITH RELATIVE HUMIDITY VALUES BETWEEN 10 AND 15
PERCENT.
FIRE WEATHER MAY ALSO BE A CONCERN JUST ABOUT EVERY DAY IN FAR
SOUTHWEST KANSAS BEHIND THE DRYLINE FROM WEDNESDAY THROUGH THE
WEEKEND, BUT PARTICULARLY FROM FRIDAY INTO SUNDAY AS SURFACE
PRESSURES FALL IN THE LEE OF THE ROCKIES AND SURFACE WINDS
INCREASE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 76 40 83 / 0 0 0 0
GCK 31 77 37 82 / 0 0 0 0
EHA 35 75 35 82 / 0 0 0 0
LBL 33 76 38 81 / 0 0 0 0
HYS 36 77 41 82 / 20 0 0 0
P28 38 78 43 81 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
&&
$$
UPDATE...BURKE
SHORT TERM...MISCUED
LONG TERM....SUDDEN
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
618 PM CDT SUN MAR 11 2012
...UPDATED FOR 00Z ...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 323 PM CDT SUN MAR 11 2012
SYNOPSIS:
ON THE SYNOPTIC SCALE...A SLOW MOVING UPPER LEVEL LOW WAS CENTERED
OVER SOUTHWEST KANSAS DURING THE MID AFTERNOON HOURS. THE RUC MODEL
WAS ANALYZING A -26C COLD CENTER AT 500MB AT THE CENTER OF THE
LOW...AND AROUND -8C AT 700MB. LOW LEVEL MOISTURE HAD WRAPPED ALL
AROUND THE LOW CENTER WHICH PREVENTED THE EROSION OF LOW STRATUS
CLOUDS...KEEPING SURFACE TEMPERATURES IN THE LOWER TO MID 40S
THROUGH THE MID AFTERNOON HOURS. THE HIGH RESOLUTION SHORT TERM
HRRR AND RUC MODELS DID AN EXCELLENT JOB WITH THE TEMPERATURES
TODAY...WITH THE NAM12 PERFORMING POORLY AS IT WAS WARMING THE
SURFACE TOO MUCH WITH CLOUDS ERODING. AS A RESULT...SURFACE-BASED
INSTABILITY DID NOT DEVELOP...AND A MORE STRATIFIED AREA OF RAIN WAS
THE RESULT ACROSS THE SOUTHERN/CENTRAL SECTIONS OF THE DDC FORECAST
AREA.
FORECAST:
WILL BE CARRYING LIKELY TO CATEGORICAL POPS THROUGH THE EARLY
EVENING HOURS ACROSS CENTRAL AND EASTERN SECTIONS OF THE FORECAST
AREA WITH DRYING BEGINNING IN THE WAKE OF THE LOW OVER THE WESTERN
COUNTIES EARLY THIS EVENING. CLEARING IS ACTUALLY STARTING TO TAKE
SHAPE OVER EXTREME SOUTHEAST COLORADO BEHIND THE LOW...AND THIS WILL
ONLY EXPAND EAST INTO SOUTHWEST KANSAS THROUGH THE EVENING. THERE
WILL NOT BE ANY COLD AIR ADVECTION BEHIND THIS LOW WITH TEMPERATURES
ACTUALLY QUITE A BIT WARMER OUTSIDE OF THE LOW AREA (NORTH, WEST,
AND SOUTH). AS FAR AS LOW TEMPERATURES ARE CONCERNED TONIGHT...HAVE
DROPPED THE LOWS A FEW DEGREES OUT WEST GIVEN THE TIMING OF CLOUD
EROSION AND THE ALREADY COOL START TO THE EVENING. RADIATIONAL
COOLING, EVEN WITH 10 KNOTS OF WIND FROM THE WEST, SHOULD DROP
TEMPERATURES DOWN INTO THE LOWER 30S PROBABLY BY MIDNIGHT...THEN
BEGIN TO STABILIZE DURING MUCH OF THE REST OF THE OVERNIGHT HOURS AS
WINDS AVERAGE 10 TO 12 KNOTS FROM THE WEST-SOUTHWEST.
TOMORROW WILL BE A VERY PLEASANT DAY AS HEIGHTS RISE WITH THE
DEPARTURE OF THE LOW NORTHEAST. 850-700MB TEMPERATURES WILL BE
WARMING SUBSTANTIALLY TONIGHT WHICH WILL SET THE STAGE FOR
TEMPERATURES TO RISE RAPIDLY AFTER SUNRISE TOMORROW. IN FACT BY
NOON TOMORROW...TEMPERATURES WILL PROBABLY ALREADY BE WELL INTO THE
MID TO UPPER 60S. HAVE NOT REALLY CHANGED THE PREVIOUS FORECAST AT
ALL REGARDING HIGHS TOMORROW...WITH WIDESPREAD MID TO PERHAPS UPPER
70S EXPECTED. THE LACK OF AN APPRECIABLE PRESSURE GRADIENT/LEESIDE
TROUGH WILL YIELD LIGHT WINDS...LIKELY LESS THAN 10 KNOTS ALL DAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 323 PM CDT SUN MAR 11 2012
THE THEME FOR THE EXTENDED PERIOD IS WARM TEMPS (WELL ABOVE NORMAL
TEMPERATURES...20 TO 30 DEGREES ABOVE NORMAL) AND SOME SMALL CHANCES
FOR THUNDERSTORMS LATE IN THE PERIOD.
FOR TUESDAY, THE LEE SURFACE TROUGH WILL STRENGTHEN WITH SW 20 TO 30
KT OF WIND DEVELOPING AT 850 HPA AND AROUND 15 TO 20 MPH
SOUTHWESTERLY DOWNSLOPE WINDS EXPECTED AT THE SFC. THIS WILL RESULT
IN A WELL MIXED ATMOSPHERE WITH RESULTANT GUSTY SOUTHWESTERLY WINDS.
MIXING FROM FORECAST SOUNDINGS IS EXPECTED TO ABOUT 700 HPA. MIX
DOWN TEMPERATURES SUPPORT LOW TO MID 80S DEG F ACROSS MUCH OF SW
KANSAS. DEWPOINTS WILL MIX DOWN TO LOW 20S DEG F TO POSSIBLY UPPER
TEENS DEG F WHICH WILL RESULT IN RH`S CRASHING DOWN TO 10 TO 15
PERCENT. AS A RESULT OF THE AFOREMENTIONED CONCERNS, HAVE ISSUED A
FIRE WEATHER WATCH (RFW) FOR TUESDAY AFTERNOON FOR FAR WESTERN
KANSAS.
BEYOND TUESDAY, A BROAD UPPER AND LOW LEVEL RIDGE ACROSS THE
SOUTHEAST ALONG WITH CONTINUED LEE SURFACE TROUGHING WILL RESULT IN
RETURN FLOW ACROSS THE SOUTHERN/CENTRAL PLAINS. THE DRYLINE SHOULD
BEGIN TO SHARPEN WEDNESDAY WITH UPPER 50S DEG F DEWPOINTS SOUTH OF
THE DRYLINE LOCATED ACROSS SOUTH CENTRAL/SE KANSAS. THE INCREASING
DEWPOINTS WILL LEAD TO MILD LOWS TOWARDS KP28 THROUGH THE REST OF
THE PD.
THE DRYLINE WILL EVENTUALLY MIX WESTWARD AS UPPER LEVEL FLOW BECOMES
MORE MERIDIONAL. THE EXACT DRYLINE POSITION FOR ANY GIVEN DAY IS
UNCERTAIN AT THIS POINT, HOWEVER...THE GENERAL TREND IN THE MODELS
IS TO MIX THE DRYLINE WESTWARD THROUGH THE END OF NEXT WEEK.
THE DRYLINE IN COMBINATION WITH WEAK IMPULSES EMBEDDED IN THE FLOW
ALOFT COULD LEAD TO SOME ISOLATED CONVECTION BEGINNING THURSDAY AND
CONTINUING THROUGH THE WEEKEND. DID NOT DEVIATE FROM THE ALLBLEND
APPROACH AS CONFIDENCE IN STORM INITIATION IS LOW AT THIS POINT. THE
BEST LOCATION FOR SEEING THUNDERSTORM ACTIVITY WILL BE ACROSS SOUTH
CENTRAL KANSAS WHERE BETTER BOUNDARY LAYER MOISTURE/HIGHER CAPE
VALUES IS EXPECTED. CAPPING COULD BE A CONCERN, PARTICULARLY IF YOU
BUY THE WARMER AND DRIER ECMWF.
LOOKING AT WEEK TWO, THE MODELS CONTINUE TO STRUGGLE WITH TIMING OF
THE EJECTION OF THE UPPER LEVEL TROUGH. BY MARCH 19TH, UL FLOW
BECOMES STRONGER AND MORE SOUTHERLY. CAPE VALUES FROM THE ECMWF SHOW
AROUND 2000 J/KG AND 0 TO 6 KM SHEAR INCREASES TO AROUND 50 KT. AT
SOME POINT SEVERE WEATHER COULD BE A SIGNIFICANT CONCERN...
PARTICULARLY AS THE UPPER LEVEL WAVE FINALLY EJECTS OUT ACROSS THE
PLAINS.
&&
.AVIATION...(FOR 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 618 PM CDT SUN MAR 11 2012
MVFR CIGS WILL BE SHORT LIVED AS BOTH A SURFACE LOW AND UPPER
LEVEL LOW PRESSURE SYSTEM MOVES SLOWLY EAST FROM WESTERN KANSAS.
BY 02Z, VFR CIGS WITH JUST A FEW STRATOCU CLOUDS WILL BE LEFT AT
KDDC AND KGCK. KHYS WILL LINGER A BIT LONGER IN THE MVFR CIGS
AROUND OVC023, BUT BREAK OUT BY 04Z. ALSO, KHYS WILL STILL SEE
SOME RAIN SHOWERS THOUGH 04Z, BUT THE RAIN HAS ENDED IN THE WEST.
&&
.FIRE WEATHER...
ISSUED AT 403 AM CDT SUN MAR 11 2012
RED FLAG WARNING CRITERIA MAY BE MET TUESDAY BEHIND THE SURFACE DRYLINE
ALONG AND WEST OF A LINE FROM DIGHTON TO GARDEN CITY TO LIBERAL.
MID-LEVEL MOMENTUM IS EXPECTED TO EASILY MIX TO THE SURFACE DURING
THE AFTERNOON WITH WIND GUSTS AS HIGH AS 25-30 KTS FOR A FEW
HOURS, ALONG WITH RELATIVE HUMIDITY VALUES BETWEEN 10 AND 15
PERCENT.
FIRE WEATHER MAY ALSO BE A CONCERN JUST ABOUT EVERY DAY IN FAR
SOUTHWEST KANSAS BEHIND THE DRYLINE FROM WEDNESDAY THROUGH THE
WEEKEND, BUT PARTICULARLY FROM FRIDAY INTO SUNDAY AS SURFACE
PRESSURES FALL IN THE LEE OF THE ROCKIES AND SURFACE WINDS
INCREASE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 76 40 83 / 30 0 0 0
GCK 31 77 37 82 / 20 0 0 0
EHA 35 75 35 82 / 10 0 0 0
LBL 33 76 38 81 / 20 0 0 0
HYS 36 77 41 82 / 30 0 0 0
P28 38 78 43 81 / 30 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
&&
$$
UPDATE...MISCUED
SHORT TERM...MISCUED
LONG TERM....SUDDEN
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1034 PM EDT SUN MAR 11 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM, MOVING NORTHEASTWARD FROM KANSAS TOWARDS
THE GREAT LAKES, WILL BRING RAIN SHOWERS MONDAY AND MONDAY NIGHT.
MIDWEST HIGH PRESSURE WILL FOLLOW WITH DRY, SPRINGLIKE CONDITIONS
TUESDAY THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
THE 03Z UPDATE HAS BEEN ISSUED TO INCREASE SKY GRIDS TO MOSTLY
CLOUDY AND TO WARM OVERNIGHT LOWS A FEW DEGREES.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE WITH A
SWATH OF DRY AIR IN THE 1000-400MB LAYER ACROSS THE UPPER OHIO
VALLEY. CIRRUS WITH MOISTURE ABOVE 400MB IS SPILLING INTO THE
AREA WELL AHEAD OF A BOUNDARY ACROSS THE ARKLATEX REGION.
TONIGHT...CLOUD COVERAGE WILL CONTINUE TO INCREASE AS THE FRONTAL
BOUNDARY MOVES INTO THE OHIO VALLEY. DESPITE A DRY AIR MASS IN
PLACE WITH TDS IN THE 20S...WARM AIR ADVECTION AND INCREASING
CLOUD COVERAGE WILL BE INHIBITORS TO TEMPERATURES DROPPING
OVERNIGHT. FORECAST LOWS ARE CLOSER TO THE WARMER MET GUIDANCE, IN
THE LOWER TO MID 40S ACROSS MUCH OF THE AREA.
MONDAY AND MONDAY NIGHT...NAM AND SREF MODEL OUTPUT THEN SHOW A
WARM FRONTAL BAND OF SHOWERS MOVING EASTWARD THROUGH THE UPPER
OHIO VALLEY DURING THE DAY MONDAY. RECENT NAM MODEL PROFILES SHOW
LESS INSTABILITY FOR MONDAY THAN EARLIER RUNS, SO HAVE NO MENTION
OF THUNDER.
RECENT SREF AND NAM MODEL OUTPUT NEXT SHOW AN OCCLUDED FRONTAL
PASSAGE MONDAY NIGHT, WITH AT BEST SCATTERED SHOWERS IN COVERAGE.
REGARDING TEMPERATURE DETAILS, NAM AND GFS MOS, AS WELL SREF MEAN
VALUES INDICATE HIGHS MONDAY 10 DEGREES WARMER THAN NORMAL
DESPITE THE CLOUDS AND PASSING SHOWERS. WITH THE UPPER JETSTREAM
ORIENTATION BECOMING MORE SOUTHWESTERLY, TEMPERATURES MONDAY NIGHT
WILL BE 15 TO 20 DEGREES WARMER THAN NORMAL.
&&
.SHORT TERM /MONDAY NIGHT/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW AN EASTBOUND HIGH
PRESSURE RIDGE WILL FOLLOW TUESDAY AND WEDNESDAY. THE ASSOCIATED
SUBSIDENCE WILL PROMOTE DRYING AND FEW CLOUDS BY LATE TUESDAY.
FORECASTED SPRINGLIKE TEMPERATURES, USING CLOSELY CONCURRING NAM,
SREF, AND GFS MODEL OUTPUT, WITH DAYTIME HIGHS 15 TO 20 DEGREES
WARMER THAN NORMAL.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
THE EXTENDED FORECAST WILL RESEMBLE MORE OF A SPRINGTIME PATTERN
THAN A LATE WINTER PATTERN.
AN UPPER LEVEL RIDGE WILL REMAIN FIXED ALONG THE EAST COAST
THROUGHOUT THE PERIOD. SOUTHERLY WINDS, AHEAD OF GREAT PLAINS LOW
PRESSURE, WILL ADD GULF MOISTURE TO THE SPRINGLIKE WARMTH. HENCE,
DAYTIME SHOWERS AND LATE DAY THUNDERSTORMS MAY BE POSSIBLE
STARTING FRIDAY.
NORMAL MID-MARCH HIGH TEMPERATURES ARE AROUND 50...BUT DURING THIS
PERIOD, HIGHS OF 70 ARE POSSIBLE DAY. THIS SHOULD REMAIN A FEW
DEGREES BELOW RECORD WARMTH.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
EXPECT VFR TO CONTINUE THROUGH TONIGHT. WITH MAINLY CLEAR SKIES
THROUGH 09Z, FOLLOWED BY THE EASTWARD SPREAD OF MID LEVEL CLOUDS.
DURING MONDAY, A FRONTAL BAND OF MVFR SHOWERS WILL SPREAD
EASTWARD THROUGH THE UPPER OHIO VALLEY. THERE MAY BE A SHORT
EPISODE OF IFR, PER RECENT ENSEMBLE MODEL GUIDANCE.
OUTLOOK...MONDAY THROUGH FRIDAY...
RESTRICTIONS MAY STILL BE POSSIBLE WITH A SECOND FRONTAL BAND OF
SHOWERS MONDAY NIGHT. HIGH PRESSURE WILL PROMOTE VFR TUESDAY
INTO THURSDAY. RESTRICTIONS WITH SHOWERS WILL BE POSSIBLE THURSDAY
NIGHT AND FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
744 PM EDT SUN MAR 11 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM, MOVING NORTHEASTWARD FROM KANSAS TOWARDS
THE GREAT LAKES, WILL BRINGS RAIN SHOWERS MONDAY AND MONDAY NIGHT.
MIDWEST HIGH PRESSURE WILL FOLLOW WITH DRY, SPRINGLIKE CONDITIONS
TUESDAY THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
AN EARLY EVENING UPDATE HAS BEEN ISSUED TO INCREASE CLOUD
COVERAGE OVERNIGHT AS MID TO UPPER LEVEL CLOUDS MOVE INTO THE
UPPER OHIO VALLEY.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE WITH A
SWATH OF DRY AIR IN THE 1000-400MB LAYER ACROSS THE UPPER OHIO
VALLEY. CLEAR SKIES THIS EVENING ARE BEGINNING TO GIVE WAY TO
CIRRUS AS MOISTURE ABOVE 400MB BEGINS TO SPILL INTO THE AREA WELL
AHEAD OF A BOUNDARY ACROSS THE ARKLATEX REGION.
TONIGHT...CLOUD COVERAGE WILL CONTINUE TO INCREASE OVERNIGHT AS
THE FRONTAL BOUNDARY MOVES INTO THE OHIO VALLEY. DESPITE A DRY AIR
MASS IN PLACE WITH TDS IN THE 20S...WARM AIR ADVECTION AND
INCREASING CLOUD COVERAGE WILL BE INHIBITORS TO TEMPERATURES
DROPPING OVERNIGHT. FORECASTS LOWS ARE CLOSER TO THE WARMER MET
GUIDANCE, IN THE LOWER 40S ACROSS MUCH OF THE AREA.
MONDAY AND MONDAY NIGHT...NAM AND SREF MODEL OUTPUT THEN SHOW A
WARM FRONTAL BAND OF SHOWERS EASTWARD THROUGH THE UPPER OHIO
VALLEY DAYTIME MONDAY. RECENT NAM MODEL PROFILES SHOW LESS
INSTABILITY FOR MONDAY THAN EARLIER RUNS, SO HAVE NO MENTION OF
THUNDER.
RECENT SREF AND NAM MODEL OUTPUT NEXT SHOW AN OCCLUDED FRONTAL
PASSAGE MONDAY NIGHT, WITH AT BEST SCATTERED SHOWERS IN COVERAGE.
REGARDING TEMPERATURE DETAILS, NAM AND GFS MOS, AS WELL SREF MEAN
VALUES INDICATE HIGHS MONDAY 10 DEGREES WARMER THAN NORMAL
DESPITE THE CLOUDS AND PASSING SHOWERS. WITH THE UPPER JETSTREAM
ORIENTATION BECOMING MORE SOUTHWESTERLY, TEMPERATURES MONDAY NIGHT
WILL BE 15 TO 20 DEGREES WARMER THAN NORMAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW AN EASTBOUND HIGH
PRESSURE RIDGE WILL FOLLOW TUESDAY AND WEDNESDAY. THE ASSOCIATED
SUBSIDENCE WILL PROMOTE DRYING AND FEW CLOUDS BY LATE TUESDAY.
FORECASTED SPRINGLIKE TEMPERATURES, USING CLOSELY CONCURRING NAM,
SREF, AND GFS MODEL OUTPUT, WITH DAYTIME HIGHS 15 TO 20 DEGREES
WARMER THAN NORMAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE EXTENDED FORECAST WILL RESEMBLE MORE OF A SPRINGTIME PATTERN
THAN A LATE WINTER PATTERN.
AN UPPER LEVEL RIDGE WILL REMAIN FIXED ALONG THE EAST COAST
THROUGHOUT THE PERIOD. SOUTHERLY WINDS, AHEAD OF GREAT PLAINS LOW
PRESSURE, WILL ADD GULF MOISTURE TO THE SPRINGLIKE WARMTH. HENCE,
DAYTIME SHOWERS AND LATE DAY THUNDERSTORMS MAY BE POSSIBLE
STARTING FRIDAY.
NORMAL MID-MARCH HIGH TEMPERATURES ARE AROUND 50...BUT DURING THIS
PERIOD, HIGHS OF 70 ARE POSSIBLE DAY. THIS SHOULD REMAIN A FEW
DEGREES BELOW RECORD WARMTH.
&&
.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
EXPECT VFR TO CONTINUE THROUGH TONIGHT. WITH MAINLY CLEAR SKIES
THROUGH 09Z, FOLLOWED BY THE EASTWARD SPREAD OF MID LEVEL CLOUDS.
DURING MONDAY, A FRONTAL BAND OF MVFR SHOWERS WILL SPREAD
EASTWARD THROUGH THE UPPER OHIO VALLEY. THERE MAY BE A SHORT
EPISODE OF IFR, PER RECENT ENSEMBLE MODEL GUIDANCE.
OUTLOOK...MONDAY THROUGH FRIDAY...
RESTRICTIONS MAY STILL BE POSSIBLE WITH A SECOND FRONTAL BAND OF
SHOWERS MONDAY NIGHT. HIGH PRESSURE WILL PROMOTE VFR TUESDAY
INTO THURSDAY. RESTRICTIONS WITH SHOWERS WILL BE POSSIBLE THURSDAY
NIGHT AND FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
255 PM EST SAT MAR 10 2012
.SYNOPSIS...
EASTBOUND HIGH PRESSURE WILL BRING DRY, SEASONABLE CONDITIONS INTO
TONIGHT, AND MILD TEMPERATURES SUNDAY. A LOW PRESSURE SYSTEM,
TRAVELING NORTHEAST FROM KANSAS TO THE GREAT LAKES, WILL BRING
RAIN SHOWERS MONDAY AND MONDAY NIGHT, FOLLOWED BY A DRY, MILD
SPELL INTO LATE WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
STRONG RADIATIONAL COOLING UNDER CLEAR SKIES TONIGHT WILL ALLOW
LOW TEMPERATURES TONIGHT TO BE NEAR NORMAL LEVELS, WHICH IS
SUPPORTED BY RECENT GFS AND NAM MOS AND GFS LAMP AND HRRR MODEL
OUTPUT.
RECENT SREF MODEL OUTPUT SHOWS SOUTHERLY WINDS ON THE BACKSIDE OF
THE HIGH PRESSURE WILL PROVIDE A WARM UP SUNDAY, WITH STILL FEW
CLOUDS. HIGH TEMPERATURES CAN BE AS MUCH AS 10 DEGREES WARMER
THAN NORMAL, PER CONSENSUS OF RECENT GFS AND NAM MOS. LOWS SUNDAY
NIGHT CAN LIKEWISE BE UP TO 10 DEGREES WARMER THAN NORMAL.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
BLEND OF RECENT SREF, CMC, AND ECMWF MODEL OUTPUT SHOW A LOW
PRESSURE SYSTEM, MOVING NORTHEASTWARD FROM KANSAS TO THE GREAT
LAKES, WILL PUSH A WARM FRONTAL BAND OF SHOWERS EASTWARD THROUGH
THE UPPER OHIO VALLEY DAYTIME MONDAY, AND A WEAKER OCCLUDED COLD
FRONTAL BAND OF SHOWERS MONDAY NIGHT.
NAM MODEL PROFILES SUGGEST THERE MAY BE ENOUGH INSTABILITY TO
INCLUDE MENTION OF A CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS.
CLOSELY CONCURRING GFS AND NAM MOS SHOW LOWS SUNDAY NIGHT CAN BE
UP TO 10 DEGREES WARMER THAN NORMAL. DESPITE THE CLOUD INCREASE
AND RAIN PROSPECTS, BLEND OF GFS AND NAM MOS CONTINUE TO SHOW
HIGHS MONDAY TO BE SIMILAR TO SUNDAY AND AS MUCH AS 10 DEGREES
WARMER THAN NORMAL. POST-SYSTEM DRYING WILL YIELD DECREASING
CLOUDS DAYTIME TUESDAY. WITH THE JETSTREAM FLOW ALOFT NOT
SUPPORTING ANY POST-SYSTEM COOLING, NAM AND GFS MOS SHOW HIGHS
TUESDAY CAN BE MORE THAN 15 DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
NAEFS AND ECMWF MODEL OUTPUT SHOW THE UPPER LEVEL JETSTREAM
PATTERN BECOMING ORIENTED SOUTHWEST TO NORTHEAST ACROSS THE UNITED
STATES THIS PERIOD, WHICH WILL PROVIDE MILD TEMPERATURES INTO THE
WEEKEND.
MIDWEST HIGH PRESSURE WILL PROVIDE DRY CONDITIONS INTO THURSDAY. A
SERIES OF GULF-MOISTURE-FED WARM FRONTS WILL BRING SHOWERS AT
TIMES THURSDAY NIGHT INTO SATURDAY.
FORECASTED TEMPERATURES TO BE MORE THAN 20 DEGREES WARMER THAN
NORMAL PER HPC-PREFERRED CONSENSUS OF GFS MOS, AND ECMWF AND NAEFS
MODEL OUTPUT.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
EXPECT VFR WITH NO MORE THAN CIRRUS PATCHES INTO SUNDAY. SURFACE WINDS
WILL BECOME LIGHT TONIGHT, AND THEN SOUTHERLY AT NO MORE THAN 8 KTS
DAYTIME SUNDAY.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
RESTRICTIONS POSSIBLE WITH FRONTAL BANDS OF SHOWERS AND SCATTERED
LATE DAY THUNDERSTORMS MONDAY AND MONDAY NIGHT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1114 AM EST SAT MAR 10 2012
.SYNOPSIS...
EASTBOUND HIGH PRESSURE WILL BRING DRY, SEASONABLE CONDITIONS THIS
AFTERNOON, AND MILD TEMPERATURES SUNDAY. A LOW PRESSURE SYSTEM, TRAVELING
FROM KANSAS TO THE GREAT LAKES, WILL BRING RAIN SHOWERS MONDAY
INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH HIGH PRESSURE PASSING EASTWARD THROUGH THE UPPER OHIO VALLEY
THIS AFTERNOON, EXPECT LOTS OF SUNSHINE WITH TEMPERATURES WARMING
TO NEAR SEASONABLE LEVELS, BASED ON RECENT SATELLITE AND SURFACE
DATA, AND HRRR AND GFS LAMP MODEL OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
PER RECENT NAM MODEL OUTPUT, HIGH PRESSURE WILL CONTINUE TO
DOMINATE THE FORECAST THROUGH SUNDAY WITH MAINLY CLEAR SKIES.
BLEND OF GFS AND NAM MOS SHOW LOWS TONIGHT WILL BE 5 TO 10
DEGREES WARMER THAN LAST NIGHT. SOUTHERLY WINDS ON THE BACKSIDE OF
THE HIGH PRESSURE WILL PROVIDE A WARM UP SUNDAY WITH HIGH
TEMPERATURES AS MUCH AS 10 DEGREES WARMER THAN NORMAL. LOWS SUNDAY
NIGHT CAN LIKEWISE BE UP TO 10 DEGREES WARMER THAN NORMAL.
BLEND OF RECENT SREF, CMC, AND ECMWF MODEL OUTPUT SHOW A LOW PRESSURE
SYSTEM, MOVING NORTHEASTWARD FROM KANSAS TO THE GREAT LAKES, WILL
PUSH A WARM FRONTAL BAND OF SHOWERS EASTWARD THROUGH THE UPPER
OHIO VALLEY DAYTIME MONDAY. DESPITE THE CLOUD INCREASE AND RAIN
PROSPECTS, BLEND OF GFS AND NAM MOS CONTINUE TO SHOW HIGHS MONDAY
TO BE SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
BLEND OF SREF, CMC, AND ECMWF MODEL OUTPUT SHOW A BAND OF SHOWERS,
ASSOCIATED WITH THE LOW PRESSURE SYSTEM`S OCCLUDED COLD FRONT
MOVING EASTWARD THROUGH THE UPPER OHIO VALLEY MONDAY NIGHT INTO
TUESDAY MORNING.
NAEFS AND ECMWF MODEL OUTPUT THEN SHOW THE UPPER LEVEL JETSTREAM
PATTERN BECOMING ORIENTED SOUTHWEST TO NORTHEAST ACROSS THE UNITED
STATES, WHICH WILL PROVIDE MILD TEMPERATURES INTO THE WEEKEND.
MIDWEST HIGH PRESSURE WILL PROVIDE DRY CONDITIONS LATE TUESDAY AND
WEDNESDAY. A SERIES OF GULF-MOISTURE-FED WARM FRONTS WILL BRING
SHOWERS LATE WEDNESDAY NIGHT INTO FRIDAY.
TEMPERATURES ARE FORECAST TO REMAIN WELL ABOVE NORMAL FOR THE
EXTENDED PERIOD.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
EXPECT VFR WITH NO MORE THAN OCCASIONAL CIRRUS INTO SUNDAY.
SURFACE WINDS WILL BECOME SOUTHERLY AT NO MORE THAN 8 KTS.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
RESTRICTIONS POSSIBLE WITH FRONTAL BANDS OF SHOWERS MONDAY INTO
MIDDAY TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
807 AM EST SAT MAR 10 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE GREAT LAKES BRINGING DRY AND
SEASONABLE TEMPERATURES TODAY...AND MILDER TEMPERATURES INTO THE
BEGINNING OF THE WEEK. A LOW PRESSURE SYSTEM TRAVELING FROM KANSAS
TO THE GREAT LAKES WILL BRING RAIN SHOWERS LATER MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
8AM UPDATE... UPDATED THE FIRST FEW HOURS WITH THE LATEST HRRR GUIDANCE.
ONLY MINOR CHANGE WAS A DECREASE IN CLOUDS FOR THIS AFTERNOON.
REMAINDER UNCHANGED.
RIDGE OF HIGH PRESSURE WILL SETTLE OVER THE
GREAT LAKES TODAY ENDING ANY COLD ADVECTION STRATOCUMULUS THAT
CONTINUES TO SKIRT THE NORTHERN COUNTIES THIS MORNING. MUCH DRIER
AIR...LIGHT WINDS...AND MOSTLY SUNNY SKIES WILL ALLOW FOR
TEMPERATURES TO QUICKLY REBOUND TO JUST ABOVE SEASONABLE LEVELS
TODAY. HIGH CIRRUS ASSOCIATED WITH A WAVE TRAVELING ACROSS CANADA
MAY BRING SOME HAZY SUN NORTH BUT SHOULD NOT DO MUCH ELSE. USED A
BLEND OF MAV/LAMP GUIDANCE FOR TEMPS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
HIGH PRESSURE WILL CONTINUE TO DOMINATE THE FORECAST THROUGH
SUNDAY. TEMPERATURES WILL ONCE AGAIN DROP INTO THE 20`S SATURDAY
NIGHT AS THE LOWER LEVELS DECOUPLE AND SKIES REMAIN CLEAR.
AS THE RIDGE SLIDES EASTWARD...A RETURN OF SOUTHERLY FLOW
AND WARM AIR ADVECTION WILL ALLOW FOR TEMPERATURES TO WARM WELL
ABOVE NORMAL. HIGH CIRRUS AND MID-DECK ASSOCIATED WITH THE NEXT
LOW PRESSURE SYSTEM...PROGGED TO MOVE FROM KANSAS TO THE GREAT
LAKES WILL APPROACH LATE SUNDAY NIGHT.
MODELS ARE IN RELATIVELY GOOD AGREEMENT THAT SHOWERS ASSOCIATED
WITH A COOL FRONT WILL CROSS MONDAY MIDDAY/AFTERNOON. WHAT IS
SLIGHTLY DIFFERENT IS THE EXIT TIMING OF THE FRONT...AS SOME OF
THE MODELS HOLD ON TO PRECIPITATION LONGER AND HANG THE FRONT OVER
THE REGION.
FOLLOWED TEMPERATURES CLOSELY TO MAV/MET GUIDANCE ERRING ON THE
COOL SIDE SATURDAY NIGHT...AND WARMER SIDE SUNDAY AND MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MEDIUM RANGE MODELS SHOW A WEAKENING SHORT WAVE TROUGH AND SURFACE
LOW TRACKING NORTHEAST ACROSS THE GREAT LAKES MONDAY NIGHT AND EARLY
TUESDAY. THE ASSOCIATED OCCLUDED COLD FRONT WILL CONTINUE A CHANCE OF
SHOWERS MONDAY NIGHT AND TUESDAY.
A BROAD UPPER RIDGE WILL REBUILD BY MIDWEEK...FOLLOWED BY
ANOTHER WEAK COLD FRONT WITH SCATTERED SHOWERS THURSDAY INTO
THURSDAY NIGHT. A SURFACE RIDGE SLIDING ACROSS THE GREAT LAKES
SHOULD PROVIDE DRY WEATHER FRIDAY.
TEMPERATURES ARE FORECAST TO REMAIN WELL ABOVE NORMAL FOR THE
EXTENDED PERIOD.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE RIDGE OVER LAKE ERIE WILL SHIFT EAST TODAY DISSIPATING
SOME MVFR/VFR STRATUS THIS MORNING ACROSS THE NORTH. CIRRUS FROM
WARM ADVECTION ACROSS THE GREAT LAKES WILL SLIDE SOUTHEAST ACROSS
REGION DURING THE DAY. NORTH WINDS EARLY THIS MORNING WILL BECOME
LIGHT THEN SHIFT TO SOUTHERLY LESS THAN 10 KTS AS SURFACE HIGH
SHIFTS EAST.
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
SURFACE RIDGE WILL PROVIDE GENERAL VFR FOR SATURDAY NIGHT INTO
SUNDAY. A WEAKENING LOW PRESSURE SYSTEM WILL TRACK NORTHEAST INTO
THE GREAT LAKES BY MONDAY NIGHT AND DRAG A COLD FRONT ACROSS THE
UPPER OHIO VALLEY. RESTRICTIONS ARE POSSIBLE IN SCATTERED SHOWERS
MONDAY AFTERNOON INTO TUESDAY...WITH A RETURN TO VFR WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1019 PM EDT SUN MAR 11 2012
.UPDATE...
ISSUED AT 1018 PM EDT SUN MAR 11 2012
LATEST WATER VAPOR IMAGERY SHOWS A WELL DEFINED UPPER LOW MOVING
TOWARD THE WESTERN GREAT LAKES. REGIONAL RADAR SHOWS A STEADY
INCREASE IN PCPN SOUTHWEST OF THE CWA. BASED ON RADAR TRENDS AND
LATEST RUC DATA...WE INCREASED POPS OVERNIGHT. THUNDER STILL A
POSSIBILITY AFTER 06Z AS THETA-E DECREASES WITH HEIGHT.
&&
.SYNOPSIS...
ISSUED AT 250 PM EDT SUN MAR 11 2012
RAIN WILL ARRIVE AFTER MIDNIGHT AS LOW PRESSURE MOVES UP FROM THE
SOUTHERN PLAINS. SOME THUNDERSTORMS ARE POSSIBLE BY MONDAY AFTERNOON
AND INTO THE EVENING...AND SOME MAY BE STRONG TO SEVERE. A SLIGHT
RISK OF SEVERE WEATHER EXISTS FOR MUCH OF SOUTHWEST LOWER MICHIGAN
FOR MONDAY AFTERNOON AND EVENING.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 337 PM EDT SUN MAR 11 2012
FORECAST IMPACTS REVOLVE AROUND SEVERE THREAT MONDAY AFTERNOON AND
EVENING. SPC CURRENTLY HAS UPGRADED MUCH OF SOUTHERN AND CENTRAL
LOWER MICHIGAN TO A SLIGHT RISK FOR DAY 2 BUT THIS IS CONDITIONAL ON
AIRMASS RECOVERY/SFC HEATING IN DRY SLOT AFTER FIRST BATCH OF
SHOWERS AND STORMS MOVES THROUGH LATE TONIGHT AND EARLY MONDAY
MORNING.
12Z NAM IS MOST BULLISH ON SEVERE THREAT SHOWING MUCH BETTER
INSTABILITY MONDAY AFTERNOON WITH SFC HEATING AND STEEP LAPSE RATES
IN THE DRY SLOT...WHILE 12Z GFS AND ECMWF SUGGEST LESS SFC BASED
INSTABILITY BUT STILL SOME POTENTIAL FOR CONVECTION AS SHEAR
PROFILES AND HELICITIES WOULD SUPPORT STRONG TO SEVERE STORMS
INCLUDING ROTATING UPDRAFTS IF SFC BASED INSTABILITY IS REALIZED.
FOR TONIGHT...LEADING EDGE OF SHOWERS SHOULD ARRIVE ACROSS THE FAR
SOUTHWEST CWA AFTER MIDNIGHT AND SPREAD NORTH. BEAST CHANCE FOR RAIN
WILL BE FROM 08Z TO 14Z AS THIS FIRST BATCH MOVES THROUGH. FORECAST
SOUNDINGS SUGGEST MARGINAL ELEVATED INSTABILITY...BUT ENOUGH TO
INCLUDE ISOLATED THUNDER IN THE FORECAST.
THEN THE DRY SLOT ARRIVES AND THERE SHOULD BE A LULL BETWEEN 14Z AND
18Z...FOLLOWED BY POTENTIAL FOR MORE CONVECTION AS SECONDARY SPEED
MAX ROTATES THROUGH DURING THE LATE AFTERNOON AND EARLY EVENING.
GIVEN STRONG SPEED SHEAR PROFILES AND DECENT LOW LEVEL
HELICITIES...CONVECTIVE TRENDS WILL HAVE TO BE CLOSELY MONITORED
DURING THE AFTERNOON AND EVENING. THREAT DECREASES AFTER 00Z WITH
LOSS OF SFC BASED INSTABILITY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 337 PM EDT SUN MAR 11 2012
UNSEASONABLY WARM WX ANTICIPATED THRU THE LONG RANGE FCST PERIOD
WITH TEMPS AVERAGING 20 TO 25 DEGREES ABOVE NORMAL THROUGH THE
WEEKEND INTO EARLY NEXT WEEK. HIGH PRESSURE WILL BRING FAIR AND VERY
WARM WX TUE/WED WITH MAX TEMPS REACHING THE UPPER 50S TO LOWER 60S
TUE AND UPPER 60S TO LOWER 70S WED.
A WEAK FRONTAL BOUNDARY WILL BRING A FEW SHOWERS WEDNESDAY NIGHT AND
A FEW SHOWERS MAY LINGER THURSDAY THROUGH SATURDAY AS THE SW FLOW
WARM AIR ADVECTION PATTERN CONTINUES. HOWEVER COVERAGE OF ANY
SHOWERS THUR-SAT SHOULD BE LOW AND MOST OF THE TIME DRY CONDITIONS
WILL CONTINUE ALONG WITH UNSEASONABLY WARM CONDITIONS.
SOME OF THE WARMEST WEATHER OF ALL SHOULD COME SUNDAY AND ESPECIALLY
MONDAY OF EARLY NEXT WEEK AS A HIGH AMPLITUDE RIDGE/OMEGA BLOCK
DEVELOPS RIGHT OVER THE GREAT LAKES REGION AS A DEEP TROF CARVES
ITSELF OUT OVER THE ROCKIES. IT IS POSSIBLE THAT THE FIRST 80 DEGREE
READING OF THE YEAR COULD COME BY NEXT MONDAY AS H5 HEIGHTS REACH
580 DM WITH H8 TEMPS POTENTIALLY REACHING 14-16C BY THEN. MEX
NUMERICAL GUIDANCE MAX TEMPS ARE BEING SKEWED DOWN TOO MUCH BY CLIMO
VALUES FOR NEXT WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 843 PM EDT SUN MAR 11 2012
VFR CONDITIONS WILL PREVAIL THIS EVENING AND AT LEAST INTO THE
OVERNIGHT HOURS. RAIN MOVING NORTHEAST FROM THE MID MISSISSIPPI
VALLEY THOUGH WILL SPREAD INTO THE TAF SITES BEFORE DAWN. RAIN
SHOULD MOVE INTO THE AREA BETWEEN 08Z AND 12Z. CONDITIONS SHOULD
DETERIORATE FAIRLY QUICK ONCE THE RAIN STARTS WITH MOST SITES
GOING TO IFR BY 12Z OR SO. CEILINGS WILL DROP TO NEAR 1000FT WITH
VSBY/S DIPPING TO 1-2 MILES IN RAIN AND FOG.
THE RAIN SHOULD AFFECT THE TAF SITES BETWEEN 08Z AND 16Z ACROSS
SOUTHWEST LOWER MICHIGAN. CONDITIONS WILL IMPROVE DURING THE
AFTERNOON HOURS OF MONDAY FOR A TIME...BUT SHOWERS AND EVEN
THUNDERSTORMS WILL BE POSSIBLE TOWARD DUSK. WINDS WILL INCREASE
BEHIND THE MONDAY MORNING RAIN WITH SOUTHWEST WINDS OF 15-25
KNOTS.
&&
.MARINE...
ISSUED AT 337 PM EDT SUN MAR 11 2012
DROPPED THE SCA FOR ALL BUT THE NORTHERN MARINE ZONE BASED ON
CURRENT OBS AND TRENDS. CONDITIONS SHOULD IMPROVE OVERNIGHT BUT
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AFTER MIDNIGHT.
&&
.HYDROLOGY...
ISSUED AT 337 PM EDT SUN MAR 11 2012
SOME RISES ARE POSSIBLE THIS WEEK AS RAIN AND THUNDERSTORMS ARE
POSSIBLE MONDAY AFTERNOON AND THURSDAY INTO THURSDAY NIGHT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...93
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM....LAURENS
AVIATION...DUKE
MARINE...OSTUNO
HYDROLOGY...OSTUNO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1237 PM EST SAT MAR 10 2012
.SYNOPSIS...
ISSUED AT 400 AM EST SAT MAR 10 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PROGRESSIVE UPR
FLOW ACROSS NAMERICA WITH DEPARTING UPR TROF/COLD AIRMASS OVER
QUEBEC DOWNSTREAM OF ZONAL FLOW FM WRN CAN INTO NW ONTARIO. 12Z-24Z
H3 RISES OVER 200M FM NW ONTARIO INTO THE GREAT LAKES INDICATE THE
COLD AIR TO THE E IS RETREATING. 00Z H85 TEMPS RANGED FM -24C AT
MOOSONEE ONTARIO TO -15C AT YPL...-14C AT GRB...AND -9C AT INL TO A
BALMY 10C AT BISMARCK AND 12C AT GLASGOW MONTANA WITHIN DOWNSLOPED
PACIFIC AIRMASS IN THE NRN PLAINS. A BAND OF MID CLDS STRETCHING FM
NW ONTARIO INTO MN/UPR MI AND WI ARE ASSOCIATED WITH THE WAD IN THE
SW FLOW BTWN SFC HI PRES OVER LOWER MI AND LO PRES EMBEDDED IN THE
ZONAL FLOW AND NW OF LK WINNIPEG. THE AREAL EXTENT OF THIS MID CLD
IS BEST DEPICTED BY THE HIER RH SHOWN ON THE NAM 285-290K ISENTROPIC
SFCS /H8-65/. BUT SINCE THE 00Z INL RAOB SHOWS A VERY DRY SFC-H85
LYR BLO THE MID LVL MSTR ASSOCIATED WITH THIS WAD...THERE HAS BEEN
NO PCPN UNDER THE CLD BAND. AWAY FM THE MAIN BAND OF
WESTERLIES...THERE IS A CUTOFF LO OVER THE DESERT SW WITHIN THE
SUBTROPICAL BRANCH.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 400 AM EST SAT MAR 10 2012
TODAY...AS THE COLD AIR TO THE E CONTINUES TO RETREAT...THE WAD MID
CLD WL SHIFT STEADILY TO THE E PER THE NAM FCST RH ON THE 285-290K
SFCS. DESPITE THE DRYNESS OF THE LLVLS SHOWN ON THE INL/GRB RAOBS...
SOME GUIDANCE DOES GENERATE LGT QPF OVER THE NE HALF OF THE CWA THIS
MRNG UNDER THE SHARPER ISENTROPIC ASCENT. OPTED TO RETAIN SCHC POPS
FOR THIS AREA EARLY. THE BACK EDGE OF THE HIER RH IS PROGGED TO
CLEAR ERY ARND 15Z. THE INCOMING WARM AIR IS FCST TO PUSH H85 TEMPS
BY 00Z SUN TO 8-10C OVER THE W TO 4-6C OVER THE E. ALTHOUGH THERE
MAY BE SOME HI CLDS... THE EXCESSIVE DRYNESS SHOWN ON THE BISMARCK
RAOB SUGS THERE WL BE NO LO CLDS. THERE WL BE A GUSTY S WIND THIS
MRNG UNDER H925 WINDS FCST UP TO 40-50KTS ON THE SRN FLANK OF PRES
FALL PASSING OVER LK SUP. SINCE THE LLVL FLOW IS FCST TO VEER MORE
TO THE W THRU THE DAY FOLLOWING THE PASSAGE OF A SFC WARM FNT...
PREFER TO TREND MAX TEMPS TOWARD THE WARMER GFS MOS. IN FACT...
MIXING TO JUST H9 ON THE GFS FCST SDNGS YIELDS HI TEMPS PEAKING IN
THE 50S OVER MUCH OF THE W HALF OF THE CWA...SEVERAL DEGREES HIER
THAN SHOWN BY THE MOS FCST. A MORE PERSISTENT SW LLVL FLOW OVER THE
E CLOSER TO THE DEPARTING COLD AIR AND BLOWING OFF THE COOL WATERS
OF LK MI WL HOLD TEMPS IN THE 40S IN THAT AREA. THE MORE WLY FLOW WL
ALSO KEEP THE KEWEENAW A BIT COOLER. GOING FCST HI TEMPS NEED LTL
ADJUSTMENT.
TNGT...UNDER BLDG UPR RDG...THE PRES GRADIENT IS FCST TO SLACKEN
QUITE A BIT...ALLOWING FOR MUCH LIGHTER WINDS. UNDER A MOCLR SKY...
EXPECT A HEALTHY DIURNAL TEMP FALL...WITH TEMPS FALLING TOWARD THE
LO END OF GUIDANCE GIVEN THE DRYNESS OF THE BISMARCK RAOB.
SUN...EXPECT ANOTHER MOSUNNY...WARM DAY WITH UPR RDG OVHD AND H85
TEMPS ARND 8C. SOME HI CLDS WL ARRIVE FM THE SW LATER IN THE DAY IN
ADVANCE OF UPR LO LIFTING OUT FM THE DESERT SW. MIXING TO JUST H9 ON
GFS FCST SDNGS WOULD RESULT IN HI TEMPS PEAKING NEAR 60 OVER AT
LEAST THE INTERIOR W HALF. BUT IN CONTRAST WITH TDAY THOUGH...THE
PRES GRADIENT WL BE RATHER WEAK...ALLOWING FOR LK BREEZE FORMATION/
COOLING NEAR THE SHORES. WITH THE PREVAILING SW FLOW...AREAS OVER
THE E DOWNWIND OF LK MI WL BE COOLER AS WELL.
SUN NGT...EXPECT THICKENING CLDS AS NEGATIVELY TILTED SHRTWV APRCHS
FM THE SW. THE EVNG WL BE DRY WITH LINGERING LLVL DRY AIR...BUT
ARRIVAL OF DEEPER MSTR/UPR DVGC IN EXIT REGION OF SUPPORTING H3 JET
MAX/H85-7 FGEN AFT 06Z WL BRING THE THREAT OF RA IN FM THE SW. THERE
ARE NO PTYPE WORRIES WITH THIS EVENT GIVEN UNSEASONABLE WARMTH OF
THE AIRMASS. ALTHOUGH INITIAL DRYNESS OF THE LLVLS WL INHIBIT FOG
FORMATION... LLVL MSTR SURGE FCST AFT 06Z WL BRING IN SOME FOG OVER
MELTING SN PACK...ESPECIALLY IN AREAS OVER THE CNTRL THAT UPSLOPE
WITH LLVL SE WIND.
.LONG TERM...(MODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST SAT MAR 10 2012
UPPER LOW PULLING OUT OF THE SW STATES TONIGHT WILL APPROACH THE
AREA ON SUN NIGHT AND CROSS THE GREAT LAKES REGION ON MON. AT THE
SFC...BROAD TROUGH FROM A LOW CENTERED OVER THE CANADIAN ROCKIES
WILL PUSH NE ACROSS THE AREA ON MON. MODELS SEEM TO HAVE COME INTO
DECENT AGREEMENT ON TIMING/TRACK OF THE UPPER LOW...WHICH LEADS TO
ABOVE NORMAL CONF ON PCPN TIMING.
MAIN PCPN OUT AHEAD OF THE UPPER LOW AND ASSOCIATED WITH THE BEST
H925-700 WAA AND 290-300K ISENTROPIC ASCENT MOVES NE ACROSS THE CWA
LATE SUN NIGHT INTO MON MORNING. THIS WILL LIKELY BRING THE BULK OF
THE PCPN WITH THE SYSTEM. COULD SEE A BRIEF BREAK IN THE LATE
MORNING AND EARLY AFTN AS MID LVL DRY AIR PUSHES THROUGH BEFORE THE
UPPER LOW MOVES OVERHEAD IN THE AFTN AND INCREASES MOISTURE AGAIN.
THIS PRODUCES ANOTHER SURGE OF SHOWERS...ESPECIALLY OVER THE WRN
HALF OF THE CWA. POTENTIAL STORMS OVER THE CNTRL/SRN MISS VALLEY
WILL LIKELY KEEP SOME OF THE DEEPER MOISTURE FROM MAKING IT INTO THE
UPPER GREAT LKS. BUT THE WARM/MOIST AIR FROM THE GULF WILL PRODUCE
PWATS NEAR 300 PERCENT OF NORMAL WITH THE WAA/ISENTROPIC ASCENT
AHEAD OF THE UPPER LOW. THUS...EXPECT AROUND 0.2-0.3IN OF RAIN WITH
THE INITIAL SURGE OF WAA. FELT THE EXISTING POPS IN THE DEFINITE
CATEGORY WERE GOOD FOR THE MORNING AND JUST TRIED TO ADD SOME
ADDITIONAL TIMING FOR THE DRY SLOT TOWARDS MID DAY AND BETTER
CHANCES OVER THE W IN THE AFTN.
WITH THE MELTING SNOW...RAIN...AND ABUNDANT LLVL MOISTURE...WILL
CONTINUE TO MENTION AREAS OF FOG FOR MON MORN. BUT HAVE TAPERED IT
OFF HEADING INTO THE AFTN...AS BUFKIT SOUNDINGS SHOWING LLVL MIXING
DIMINISHING THE POTENTIAL. DID LEAVE THE FOG IN OVER THE E WITH THE
SW FLOW AND WARM/MOIST AIR OVER LK MI...MAINLY E OF A LINE FROM
MUNISING TO ESCANABA.
MON NIGHT...WITH SFC TROUGH AND UPPER LOW QUICKLY MOVING NE ON MON
NIGHT...HIGH PRESSURE RIDGE WILL START TO EDGE INTO THE AREA
OVERNIGHT MON FROM SRN MN. WILL LIKELY STILL SEE SOME WRAP AROUND
SHOWERS IN THE EVENING FROM THE UPPER LOW ENERGY...BUT WILL DIMINISH
FROM SW TO NE WITH THE UPPER LOW QUICKLY MOVING NE. THIS QUICK
MOVEMENT...ALONG WITH THE HIGH PRESSURE RIDGE...WILL LEAD TO A SHARP
CLEARING LINE MOVING IN OVERNIGHT. ONE ITEM OF NOTE IS THE NAM
SHOWING LLVL MOISTURE BELOW THE DEVELOPING INVERSION AT 2.5KFT.
COULD LEAD TO SOME LINGERING FOG OR LOW CLOUDS BEHIND THE EXITING
UPPER LOW. GFS IS NOT AS PRONOUNCED AND WITH THE NAM TENDING TO
OVERDO LLVL MOISTURE...WILL LEAVE OUT OF THE FCST AT THIS TIME.
DAYS 4 THROUGH 7 /TUES THROUGH FRIDAY/...
UPPER TROUGH AMPLIFYING OVER THE CENTRAL/ERN CONUS WILL LEAD TO A
WARM/DRY DAY ON TUES AS A SFC HIGH SLIDES ACROSS THE CWA. COULD LEAD
TO SOME LK BREEZES DEPENDING ON THE TIMING OF THE SFC RIDGE MOVING
THROUGH. BUT AT THIS FAR OUT...WILL NOT TRY TO GET TOO FANCY ON
TEMPS/WINDS ALONG LK SUPERIOR. AS FOR HIGHS...MIXING TOWARDS
H875 YIELDS HIGHS IN THE UPPER 50S TO NEAR 60 ALONG THE WI BORDER.
HAVE KEPT TEMPS IN THE 40S NEAR GRAND MARAIS...WHERE NW WINDS OFF LK
SUPERIOR WILL LINGER INTO THE EARLY AFTN HRS AND LIMIT WARMING.
HIGH SHIFTS E TUES NIGHT AND WED. SHORTWAVE IN THE NRN STREAM
UPPER FLOW RUNNING FROM THE PAC NW TO HUDSON BAY WILL SWEEP A COLD
FRONT ACROSS THE AREA ON WED AFTN. MAIN ENERGY FROM THE
SHORTWAVE AND THE COLD FRONT REMAINS WELL NNW OF THE AREA IN NRN
ONTARIO. THIS...COMBINED WITH LIMITED MID LVL MOISTURE...THINK THE
PCPN CHANCES ARE LOW. BUT...DID LEAVE SLIGHT CHANCES OVER THE SE
HALF OF THE CWA...AS ECMWF/GEM/GFS TRY TO PULL MLCAPE VALUES
TOWARDS 200 J/KG. ML LAPSE RATES ARE FAIRLY STRONG...AROUND
7-8C/KM...BUT THE MID LVL DRY AIR AND CAP NEAR H850 WILL LIKELY
KEEP DEVELOPMENT FROM OCCURRING. BEST CHANCES WILL BE S OF THE
CWA...IN THE SE HALF OF WI...BUT FELT KEEPING THE SLIGHT CHANCES IN
NEAR THE WI BORDER WAS REASONABLE. MIXING AGAIN TO NEAR H875 /9C/ ON
WED WILL PRODUCE HIGHS IN THE LOW/MID 60S AWAY FROM THE COOLER FLOW
OFF LK MI. STRONGER SW FLOW AHEAD OF THE COLD FRONT WILL LIMIT
CONCERNS OF COOLING DUE TO LK BREEZES NEAR LK SUPERIOR. THIS SWRLY
FLOW WILL LIKELY LEAD TO DOWNSLOPE WARMING NEAR LK SUPERIOR...SO
HAVE BUMPED TEMPS UP SOME IN THOSE AREAS.
COLD FRONT SLIDES E ON WED NIGHT AND COULD LEAD TO A SLIGHT COOL
DOWN ON THURS. ECMWF/GEM KEEP IT WARM IN THE 50/60S WHILE THE GFS
HAS IN THE 40S. HAVE TRENDED TOWARDS THE WARMER ECMWF...SINCE IT
TRADITIONAL PERFORMS MUCH BETTER IN WELL ABOVE NORMAL PATTERNS AND
DUE TO THE COLD BIAS OF THE GFS. THUS...HAVE TEMPS IN THE
50S...EXCEPT OVER THE KEWEENAW AND NEAR LK SUPERIOR OVER THE NCTNRL
AND E...WHERE LIGHT WINDS OFF LK SUPERIOR WILL KEEP TEMPS COOLER.
OTHERWISE...UPPER RIDGE REMAINS IN PLACE INTO NEXT WEEKEND. THIS
WILL CONTINUE TO PRODUCE WARM/DRY WX FOR THE UPPER GREAT LKS. MODELS
ARE TRYING TO SHOW THE UPPER TROUGH THAT WILL HAVE BEEN STATIONED IN
THE PACIFIC OFF THE W COAST OVER THE NEXT 7 DAYS TO TRY AND MOVE
INLAND THIS WEEKEND...AMPLIFYING THE RIDGE EVEN FURTHER. AS THIS
TROUGH CONTINUES E NEXT WEEK...COULD SEE A TRANSITION TO A LITTLE
MORE ACTIVE WX AND MORE NORMAL TEMPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1236 PM EST SAT MAR 10 2012
VFR CEILINGS AND VIS SHOULD REMAIN OVER THE NEXT 24 HOURS /WITH JUST
A FEW HIGH CLOUDS/. THE MAIN THREAT WILL CONTINUE TO BE THE STRONG
SOUTHERLY WINDS...WHICH WILL DIMINISH THIS AFTERNOON.
HOWEVER...WINDS NEAR OF 30 TO 40KTS SHOULD REMAIN A COUPLE THOUSAND
FEET ABOVE THE SFC THROUGH THE 09Z SUNDAY AT IWD AND SAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 AM EST SAT MAR 10 2012
EXPECT A S GALE UP TO 40 KTS OVER THE E HALF OF LK SUP INTO THIS
AFTERNOON UNDER TIGHTENING PRES GRADIENT BETWEEN DEPARTING HI PRES
TO THE SE AND LO PRES MOVING ACROSS SOUTHERN CANADA. THE ARRIVAL OF
A WEAKER PRESSURE GRADIENT WILL CAUSE DIMINISHING WINDS LATER TODAY
THRU SUN.
AN UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE UPPER GREAT LAKES
ON MONDAY AND EXIT ON MONDAY NIGHT...ALLOWING A HIGH PRESSURE RIDGE
TO MOVE OVER THE AREA ON TUESDAY. WINDS DURING THIS PERIOD SHOULD
STAY BELOW 25KTS. A COLD FRONT FROM A LOW IN NRN ONTARIO WILL BRUSH
THE AREA ON WEDNESDAY. STRONG SOUTHERLY WINDS AHEAD OF THIS FRONT
SHOULD PRODUCE WINDS IN THE 20-25KT RANGE. THINK THE MARINE LAYER
WILL LIMIT POTENTIAL FOR HIGHER WINDS ALOFT TO REACH THE SFC.
&&
.HYDROLOGY...
ISSUED AT 400 AM EST SAT MAR 10 2012
LITTLE HAS CHANGED ON THE HYDROLOGY FRONT OVER THE LAST COUPLE
DAYS. STILL EXPECT WELL ABOVE NORMAL TEMPS OVER THE NEXT 7
DAYS...WHICH WILL TAKE A SIGNIFICANT BITE OUT OF THE SNOW PACK...IF
NOT EATING ALL OF IT.
TRADITIONALLY NEED ABOUT 2 DAYS OF TEMPERATURES IN THE MID-UPPER 40S
OR ABOVE AND TD/S ABOVE FREEZING TO RIPEN THE SNOWPACK. WARM TEMPS
EARLIER THIS WEEK DID JUST THAT OVER MUCH OF THE AREA...ALTHOUGH THE
COOL DOWN OVER THE LAST TWO DAYS HELPED SLOW/END THE MELT.
THUS...WITH THE TEMPS THIS WEEKEND EXPECTED TO EXCEED THAT...SHOULD
EASILY HAVE A RIPE SNOWPACK FOR MELTING THIS WEEKEND. THE RIPE
SNOWPACK WILL BE AIDED BY RAIN EXPECTED LATE SUN NIGHT AND INTO
MON...WHICH IS EXPECTED TO PRODUCE BETWEEN 0.25-0.40IN OF
PRECIPITATION. THEREFORE...EXPECT TO SEE RIVERS START TO RISE
SUN INTO MON AND CONTINUE THROUGH THIS WEEK UNTIL THE SNOW IS
MELTED. OVERNIGHT LOWS DON/T LOOK TO GET BELOW FREEZING AFTER
TONIGHT...SO SHOULD SEE A FAIRLY STEADY MELT. WILL LIKELY SEE SNOW
PACK GONE OVER MUCH OF THE AREA BY THE END OF THIS WEEK...EXCEPT FOR
WOODED/SHADED LOCATIONS.
WITH THIS FAIRLY FAST MELT AND RUNOFF...EXPECT SOME OF THE RIVERS
ACROSS THE AREA TO EXCEED THEIR BANKS BY THE END OF NEXT WEEK.
PERSONS LIVING NEAR RIVERS AND STREAMS SHOULD MONITOR THE LATEST
RIVER CONDITIONS AND USE CAUTION IF WALKING ALONG RIVER
BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
FINALLY...NOT MUCH ICE HAS BEEN NOTED BY OBSERVERS ON THE FASTER
FLOWING RIVERS OVER NRN UPPER MI. BUT THE FORD RIVER...BOTH AT HYDE
AND THE MOUTH AT LK MI...STILL HAS A GOOD ICE COVER THAT LEADS TO
SOME CONCERN FOR ICE JAM POTENTIAL WITH THE FASTER RUNOFF. ALTHOUGH
LIMITED SNOW WAS NOTED NEAR LK MI...THERE IS STILL 5-10IN OF SNOW
AND NOHRSC ESTIMATED AROUND 1.5IN OF LIQUID TOWARDS THE HEADWATERS
THAT WILL MELTED OVER THE COMING DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LSZ249>251-266-
267.
LAKE MICHIGAN...
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LMZ248-250.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LMZ221.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KF
MARINE...KC/SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
612 AM EST SAT MAR 10 2012
.SYNOPSIS...
ISSUED AT 400 AM EST SAT MAR 10 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PROGRESSIVE UPR
FLOW ACROSS NAMERICA WITH DEPARTING UPR TROF/COLD AIRMASS OVER
QUEBEC DOWNSTREAM OF ZONAL FLOW FM WRN CAN INTO NW ONTARIO. 12Z-24Z
H3 RISES OVER 200M FM NW ONTARIO INTO THE GREAT LAKES INDICATE THE
COLD AIR TO THE E IS RETREATING. 00Z H85 TEMPS RANGED FM -24C AT
MOOSONEE ONTARIO TO -15C AT YPL...-14C AT GRB...AND -9C AT INL TO A
BALMY 10C AT BISMARCK AND 12C AT GLASGOW MONTANA WITHIN DOWNSLOPED
PACIFIC AIRMASS IN THE NRN PLAINS. A BAND OF MID CLDS STRETCHING FM
NW ONTARIO INTO MN/UPR MI AND WI ARE ASSOCIATED WITH THE WAD IN THE
SW FLOW BTWN SFC HI PRES OVER LOWER MI AND LO PRES EMBEDDED IN THE
ZONAL FLOW AND NW OF LK WINNIPEG. THE AREAL EXTENT OF THIS MID CLD
IS BEST DEPICTED BY THE HIER RH SHOWN ON THE NAM 285-290K ISENTROPIC
SFCS /H8-65/. BUT SINCE THE 00Z INL RAOB SHOWS A VERY DRY SFC-H85
LYR BLO THE MID LVL MSTR ASSOCIATED WITH THIS WAD...THERE HAS BEEN
NO PCPN UNDER THE CLD BAND. AWAY FM THE MAIN BAND OF
WESTERLIES...THERE IS A CUTOFF LO OVER THE DESERT SW WITHIN THE
SUBTROPICAL BRANCH.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 400 AM EST SAT MAR 10 2012
TODAY...AS THE COLD AIR TO THE E CONTINUES TO RETREAT...THE WAD MID
CLD WL SHIFT STEADILY TO THE E PER THE NAM FCST RH ON THE 285-290K
SFCS. DESPITE THE DRYNESS OF THE LLVLS SHOWN ON THE INL/GRB RAOBS...
SOME GUIDANCE DOES GENERATE LGT QPF OVER THE NE HALF OF THE CWA THIS
MRNG UNDER THE SHARPER ISENTROPIC ASCENT. OPTED TO RETAIN SCHC POPS
FOR THIS AREA EARLY. THE BACK EDGE OF THE HIER RH IS PROGGED TO
CLEAR ERY ARND 15Z. THE INCOMING WARM AIR IS FCST TO PUSH H85 TEMPS
BY 00Z SUN TO 8-10C OVER THE W TO 4-6C OVER THE E. ALTHOUGH THERE
MAY BE SOME HI CLDS... THE EXCESSIVE DRYNESS SHOWN ON THE BISMARCK
RAOB SUGS THERE WL BE NO LO CLDS. THERE WL BE A GUSTY S WIND THIS
MRNG UNDER H925 WINDS FCST UP TO 40-50KTS ON THE SRN FLANK OF PRES
FALL PASSING OVER LK SUP. SINCE THE LLVL FLOW IS FCST TO VEER MORE
TO THE W THRU THE DAY FOLLOWING THE PASSAGE OF A SFC WARM FNT...
PREFER TO TREND MAX TEMPS TOWARD THE WARMER GFS MOS. IN FACT...
MIXING TO JUST H9 ON THE GFS FCST SDNGS YIELDS HI TEMPS PEAKING IN
THE 50S OVER MUCH OF THE W HALF OF THE CWA...SEVERAL DEGREES HIER
THAN SHOWN BY THE MOS FCST. A MORE PERSISTENT SW LLVL FLOW OVER THE
E CLOSER TO THE DEPARTING COLD AIR AND BLOWING OFF THE COOL WATERS
OF LK MI WL HOLD TEMPS IN THE 40S IN THAT AREA. THE MORE WLY FLOW WL
ALSO KEEP THE KEWEENAW A BIT COOLER. GOING FCST HI TEMPS NEED LTL
ADJUSTMENT.
TNGT...UNDER BLDG UPR RDG...THE PRES GRADIENT IS FCST TO SLACKEN
QUITE A BIT...ALLOWING FOR MUCH LIGHTER WINDS. UNDER A MOCLR SKY...
EXPECT A HEALTHY DIURNAL TEMP FALL...WITH TEMPS FALLING TOWARD THE
LO END OF GUIDANCE GIVEN THE DRYNESS OF THE BISMARCK RAOB.
SUN...EXPECT ANOTHER MOSUNNY...WARM DAY WITH UPR RDG OVHD AND H85
TEMPS ARND 8C. SOME HI CLDS WL ARRIVE FM THE SW LATER IN THE DAY IN
ADVANCE OF UPR LO LIFTING OUT FM THE DESERT SW. MIXING TO JUST H9 ON
GFS FCST SDNGS WOULD RESULT IN HI TEMPS PEAKING NEAR 60 OVER AT
LEAST THE INTERIOR W HALF. BUT IN CONTRAST WITH TDAY THOUGH...THE
PRES GRADIENT WL BE RATHER WEAK...ALLOWING FOR LK BREEZE FORMATION/
COOLING NEAR THE SHORES. WITH THE PREVAILING SW FLOW...AREAS OVER
THE E DOWNWIND OF LK MI WL BE COOLER AS WELL.
SUN NGT...EXPECT THICKENING CLDS AS NEGATIVELY TILTED SHRTWV APRCHS
FM THE SW. THE EVNG WL BE DRY WITH LINGERING LLVL DRY AIR...BUT
ARRIVAL OF DEEPER MSTR/UPR DVGC IN EXIT REGION OF SUPPORTING H3 JET
MAX/H85-7 FGEN AFT 06Z WL BRING THE THREAT OF RA IN FM THE SW. THERE
ARE NO PTYPE WORRIES WITH THIS EVENT GIVEN UNSEASONABLE WARMTH OF
THE AIRMASS. ALTHOUGH INITIAL DRYNESS OF THE LLVLS WL INHIBIT FOG
FORMATION... LLVL MSTR SURGE FCST AFT 06Z WL BRING IN SOME FOG OVER
MELTING SN PACK...ESPECIALLY IN AREAS OVER THE CNTRL THAT UPSLOPE
WITH LLVL SE WIND.
.LONG TERM...(MODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST SAT MAR 10 2012
UPPER LOW PULLING OUT OF THE SW STATES TONIGHT WILL APPROACH THE
AREA ON SUN NIGHT AND CROSS THE GREAT LAKES REGION ON MON. AT THE
SFC...BROAD TROUGH FROM A LOW CENTERED OVER THE CANADIAN ROCKIES
WILL PUSH NE ACROSS THE AREA ON MON. MODELS SEEM TO HAVE COME INTO
DECENT AGREEMENT ON TIMING/TRACK OF THE UPPER LOW...WHICH LEADS TO
ABOVE NORMAL CONF ON PCPN TIMING.
MAIN PCPN OUT AHEAD OF THE UPPER LOW AND ASSOCIATED WITH THE BEST
H925-700 WAA AND 290-300K ISENTROPIC ASCENT MOVES NE ACROSS THE CWA
LATE SUN NIGHT INTO MON MORNING. THIS WILL LIKELY BRING THE BULK OF
THE PCPN WITH THE SYSTEM. COULD SEE A BRIEF BREAK IN THE LATE
MORNING AND EARLY AFTN AS MID LVL DRY AIR PUSHES THROUGH BEFORE THE
UPPER LOW MOVES OVERHEAD IN THE AFTN AND INCREASES MOISTURE AGAIN.
THIS PRODUCES ANOTHER SURGE OF SHOWERS...ESPECIALLY OVER THE WRN
HALF OF THE CWA. POTENTIAL STORMS OVER THE CNTRL/SRN MISS VALLEY
WILL LIKELY KEEP SOME OF THE DEEPER MOISTURE FROM MAKING IT INTO THE
UPPER GREAT LKS. BUT THE WARM/MOIST AIR FROM THE GULF WILL PRODUCE
PWATS NEAR 300 PERCENT OF NORMAL WITH THE WAA/ISENTROPIC ASCENT
AHEAD OF THE UPPER LOW. THUS...EXPECT AROUND 0.2-0.3IN OF RAIN WITH
THE INITIAL SURGE OF WAA. FELT THE EXISTING POPS IN THE DEFINITE
CATEGORY WERE GOOD FOR THE MORNING AND JUST TRIED TO ADD SOME
ADDITIONAL TIMING FOR THE DRY SLOT TOWARDS MID DAY AND BETTER
CHANCES OVER THE W IN THE AFTN.
WITH THE MELTING SNOW...RAIN...AND ABUNDANT LLVL MOISTURE...WILL
CONTINUE TO MENTION AREAS OF FOG FOR MON MORN. BUT HAVE TAPERED IT
OFF HEADING INTO THE AFTN...AS BUFKIT SOUNDINGS SHOWING LLVL MIXING
DIMINISHING THE POTENTIAL. DID LEAVE THE FOG IN OVER THE E WITH THE
SW FLOW AND WARM/MOIST AIR OVER LK MI...MAINLY E OF A LINE FROM
MUNISING TO ESCANABA.
MON NIGHT...WITH SFC TROUGH AND UPPER LOW QUICKLY MOVING NE ON MON
NIGHT...HIGH PRESSURE RIDGE WILL START TO EDGE INTO THE AREA
OVERNIGHT MON FROM SRN MN. WILL LIKELY STILL SEE SOME WRAP AROUND
SHOWERS IN THE EVENING FROM THE UPPER LOW ENERGY...BUT WILL DIMINISH
FROM SW TO NE WITH THE UPPER LOW QUICKLY MOVING NE. THIS QUICK
MOVEMENT...ALONG WITH THE HIGH PRESSURE RIDGE...WILL LEAD TO A SHARP
CLEARING LINE MOVING IN OVERNIGHT. ONE ITEM OF NOTE IS THE NAM
SHOWING LLVL MOISTURE BELOW THE DEVELOPING INVERSION AT 2.5KFT.
COULD LEAD TO SOME LINGERING FOG OR LOW CLOUDS BEHIND THE EXITING
UPPER LOW. GFS IS NOT AS PRONOUNCED AND WITH THE NAM TENDING TO
OVERDO LLVL MOISTURE...WILL LEAVE OUT OF THE FCST AT THIS TIME.
DAYS 4 THROUGH 7 /TUES THROUGH FRIDAY/...
UPPER TROUGH AMPLIFYING OVER THE CENTRAL/ERN CONUS WILL LEAD TO A
WARM/DRY DAY ON TUES AS A SFC HIGH SLIDES ACROSS THE CWA. COULD LEAD
TO SOME LK BREEZES DEPENDING ON THE TIMING OF THE SFC RIDGE MOVING
THROUGH. BUT AT THIS FAR OUT...WILL NOT TRY TO GET TOO FANCY ON
TEMPS/WINDS ALONG LK SUPERIOR. AS FOR HIGHS...MIXING TOWARDS
H875 YIELDS HIGHS IN THE UPPER 50S TO NEAR 60 ALONG THE WI BORDER.
HAVE KEPT TEMPS IN THE 40S NEAR GRAND MARAIS...WHERE NW WINDS OFF LK
SUPERIOR WILL LINGER INTO THE EARLY AFTN HRS AND LIMIT WARMING.
HIGH SHIFTS E TUES NIGHT AND WED. SHORTWAVE IN THE NRN STREAM
UPPER FLOW RUNNING FROM THE PAC NW TO HUDSON BAY WILL SWEEP A COLD
FRONT ACROSS THE AREA ON WED AFTN. MAIN ENERGY FROM THE
SHORTWAVE AND THE COLD FRONT REMAINS WELL NNW OF THE AREA IN NRN
ONTARIO. THIS...COMBINED WITH LIMITED MID LVL MOISTURE...THINK THE
PCPN CHANCES ARE LOW. BUT...DID LEAVE SLIGHT CHANCES OVER THE SE
HALF OF THE CWA...AS ECMWF/GEM/GFS TRY TO PULL MLCAPE VALUES
TOWARDS 200 J/KG. ML LAPSE RATES ARE FAIRLY STRONG...AROUND
7-8C/KM...BUT THE MID LVL DRY AIR AND CAP NEAR H850 WILL LIKELY
KEEP DEVELOPMENT FROM OCCURRING. BEST CHANCES WILL BE S OF THE
CWA...IN THE SE HALF OF WI...BUT FELT KEEPING THE SLIGHT CHANCES IN
NEAR THE WI BORDER WAS REASONABLE. MIXING AGAIN TO NEAR H875 /9C/ ON
WED WILL PRODUCE HIGHS IN THE LOW/MID 60S AWAY FROM THE COOLER FLOW
OFF LK MI. STRONGER SW FLOW AHEAD OF THE COLD FRONT WILL LIMIT
CONCERNS OF COOLING DUE TO LK BREEZES NEAR LK SUPERIOR. THIS SWRLY
FLOW WILL LIKELY LEAD TO DOWNSLOPE WARMING NEAR LK SUPERIOR...SO
HAVE BUMPED TEMPS UP SOME IN THOSE AREAS.
COLD FRONT SLIDES E ON WED NIGHT AND COULD LEAD TO A SLIGHT COOL
DOWN ON THURS. ECMWF/GEM KEEP IT WARM IN THE 50/60S WHILE THE GFS
HAS IN THE 40S. HAVE TRENDED TOWARDS THE WARMER ECMWF...SINCE IT
TRADITIONAL PERFORMS MUCH BETTER IN WELL ABOVE NORMAL PATTERNS AND
DUE TO THE COLD BIAS OF THE GFS. THUS...HAVE TEMPS IN THE
50S...EXCEPT OVER THE KEWEENAW AND NEAR LK SUPERIOR OVER THE NCTNRL
AND E...WHERE LIGHT WINDS OFF LK SUPERIOR WILL KEEP TEMPS COOLER.
OTHERWISE...UPPER RIDGE REMAINS IN PLACE INTO NEXT WEEKEND. THIS
WILL CONTINUE TO PRODUCE WARM/DRY WX FOR THE UPPER GREAT LKS. MODELS
ARE TRYING TO SHOW THE UPPER TROUGH THAT WILL HAVE BEEN STATIONED IN
THE PACIFIC OFF THE W COAST OVER THE NEXT 7 DAYS TO TRY AND MOVE
INLAND THIS WEEKEND...AMPLIFYING THE RIDGE EVEN FURTHER. AS THIS
TROUGH CONTINUES E NEXT WEEK...COULD SEE A TRANSITION TO A LITTLE
MORE ACTIVE WX AND MORE NORMAL TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 610 AM EST SAT MAR 10 2012
WITH DRY LLVL AIRMASS DOMINATING THIS FCST PERIOD...EXPECT VFR
CONDITIONS AT ALL 3 TAF SITES. GUSTY S WINDS WILL BE THE RULE THRU
THIS MORNING TO THE S OF PRES FALL CENTER MIGRATING OVER ONTARIO/LK
SUP AND UNDER SHARP PRES GRADIENT BTWN DEPARTING HI TO THE SE AND LO
PRES TRACKING ACRS SOUTHERN CAN. LOOK FOR THE WINDS TO DIMINISH
BEGINNING THIS AFTN ONCE THE PRES FALL CENTER SHIFTS FARTHER TO THE
E AND THE GRADIENT WEAKENS OVER UPR MI. WINDS WILL BE UNDER 10KTS
BY THIS EVNG.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 AM EST SAT MAR 10 2012
EXPECT A S GALE UP TO 40 KTS OVER THE E HALF OF LK SUP INTO THIS
AFTERNOON UNDER TIGHTENING PRES GRADIENT BETWEEN DEPARTING HI PRES
TO THE SE AND LO PRES MOVING ACROSS SOUTHERN CANADA. THE ARRIVAL OF
A WEAKER PRESSURE GRADIENT WILL CAUSE DIMINISHING WINDS LATER TODAY
THRU SUN.
AN UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE UPPER GREAT LAKES
ON MONDAY AND EXIT ON MONDAY NIGHT...ALLOWING A HIGH PRESSURE RIDGE
TO MOVE OVER THE AREA ON TUESDAY. WINDS DURING THIS PERIOD SHOULD
STAY BELOW 25KTS. A COLD FRONT FROM A LOW IN NRN ONTARIO WILL BRUSH
THE AREA ON WEDNESDAY. STRONG SOUTHERLY WINDS AHEAD OF THIS FRONT
SHOULD PRODUCE WINDS IN THE 20-25KT RANGE. THINK THE MARINE LAYER
WILL LIMIT POTENTIAL FOR HIGHER WINDS ALOFT TO REACH THE SFC.
&&
.HYDROLOGY...
ISSUED AT 400 AM EST SAT MAR 10 2012
LITTLE HAS CHANGED ON THE HYDROLOGY FRONT OVER THE LAST COUPLE
DAYS. STILL EXPECT WELL ABOVE NORMAL TEMPS OVER THE NEXT 7
DAYS...WHICH WILL TAKE A SIGNIFICANT BITE OUT OF THE SNOW PACK...IF
NOT EATING ALL OF IT.
TRADITIONALLY NEED ABOUT 2 DAYS OF TEMPERATURES IN THE MID-UPPER 40S
OR ABOVE AND TD/S ABOVE FREEZING TO RIPEN THE SNOWPACK. WARM TEMPS
EARLIER THIS WEEK DID JUST THAT OVER MUCH OF THE AREA...ALTHOUGH THE
COOL DOWN OVER THE LAST TWO DAYS HELPED SLOW/END THE MELT.
THUS...WITH THE TEMPS THIS WEEKEND EXPECTED TO EXCEED THAT...SHOULD
EASILY HAVE A RIPE SNOWPACK FOR MELTING THIS WEEKEND. THE RIPE
SNOWPACK WILL BE AIDED BY RAIN EXPECTED LATE SUN NIGHT AND INTO
MON...WHICH IS EXPECTED TO PRODUCE BETWEEN 0.25-0.40IN OF
PRECIPITATION. THEREFORE...EXPECT TO SEE RIVERS START TO RISE
SUN INTO MON AND CONTINUE THROUGH THIS WEEK UNTIL THE SNOW IS
MELTED. OVERNIGHT LOWS DON/T LOOK TO GET BELOW FREEZING AFTER
TONIGHT...SO SHOULD SEE A FAIRLY STEADY MELT. WILL LIKELY SEE SNOW
PACK GONE OVER MUCH OF THE AREA BY THE END OF THIS WEEK...EXCEPT FOR
WOODED/SHADED LOCATIONS.
WITH THIS FAIRLY FAST MELT AND RUNOFF...EXPECT SOME OF THE RIVERS
ACROSS THE AREA TO EXCEED THEIR BANKS BY THE END OF NEXT WEEK.
PERSONS LIVING NEAR RIVERS AND STREAMS SHOULD MONITOR THE LATEST
RIVER CONDITIONS AND USE CAUTION IF WALKING ALONG RIVER
BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
FINALLY...NOT MUCH ICE HAS BEEN NOTED BY OBSERVERS ON THE FASTER
FLOWING RIVERS OVER NRN UPPER MI. BUT THE FORD RIVER...BOTH AT HYDE
AND THE MOUTH AT LK MI...STILL HAS A GOOD ICE COVER THAT LEADS TO
SOME CONCERN FOR ICE JAM POTENTIAL WITH THE FASTER RUNOFF. ALTHOUGH
LIMITED SNOW WAS NOTED NEAR LK MI...THERE IS STILL 5-10IN OF SNOW
AND NOHRSC ESTIMATED AROUND 1.5IN OF LIQUID TOWARDS THE HEADWATERS
THAT WILL MELTED OVER THE COMING DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LSZ249>251-266-
267.
LAKE MICHIGAN...
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LMZ248-250.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LMZ221.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC/SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
404 AM EST SAT MAR 10 2012
.SYNOPSIS...
ISSUED AT 400 AM EST SAT MAR 10 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PROGRESSIVE UPR
FLOW ACROSS NAMERICA WITH DEPARTING UPR TROF/COLD AIRMASS OVER
QUEBEC DOWNSTREAM OF ZONAL FLOW FM WRN CAN INTO NW ONTARIO. 12Z-24Z
H3 RISES OVER 200M FM NW ONTARIO INTO THE GREAT LAKES INDICATE THE
COLD AIR TO THE E IS RETREATING. 00Z H85 TEMPS RANGED FM -24C AT
MOOSONEE ONTARIO TO -15C AT YPL...-14C AT GRB...AND -9C AT INL TO A
BALMY 10C AT BISMARCK AND 12C AT GLASGOW MONTANA WITHIN DOWNSLOPED
PACIFIC AIRMASS IN THE NRN PLAINS. A BAND OF MID CLDS STRETCHING FM
NW ONTARIO INTO MN/UPR MI AND WI ARE ASSOCIATED WITH THE WAD IN THE
SW FLOW BTWN SFC HI PRES OVER LOWER MI AND LO PRES EMBEDDED IN THE
ZONAL FLOW AND NW OF LK WINNIPEG. THE AREAL EXTENT OF THIS MID CLD
IS BEST DEPICTED BY THE HIER RH SHOWN ON THE NAM 285-290K ISENTROPIC
SFCS /H8-65/. BUT SINCE THE 00Z INL RAOB SHOWS A VERY DRY SFC-H85
LYR BLO THE MID LVL MSTR ASSOCIATED WITH THIS WAD...THERE HAS BEEN
NO PCPN UNDER THE CLD BAND. AWAY FM THE MAIN BAND OF
WESTERLIES...THERE IS A CUTOFF LO OVER THE DESERT SW WITHIN THE
SUBTROPICAL BRANCH.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 400 AM EST SAT MAR 10 2012
TODAY...AS THE COLD AIR TO THE E CONTINUES TO RETREAT...THE WAD MID
CLD WL SHIFT STEADILY TO THE E PER THE NAM FCST RH ON THE 285-290K
SFCS. DESPITE THE DRYNESS OF THE LLVLS SHOWN ON THE INL/GRB RAOBS...
SOME GUIDANCE DOES GENERATE LGT QPF OVER THE NE HALF OF THE CWA THIS
MRNG UNDER THE SHARPER ISENTROPIC ASCENT. OPTED TO RETAIN SCHC POPS
FOR THIS AREA EARLY. THE BACK EDGE OF THE HIER RH IS PROGGED TO
CLEAR ERY ARND 15Z. THE INCOMING WARM AIR IS FCST TO PUSH H85 TEMPS
BY 00Z SUN TO 8-10C OVER THE W TO 4-6C OVER THE E. ALTHOUGH THERE
MAY BE SOME HI CLDS... THE EXCESSIVE DRYNESS SHOWN ON THE BISMARCK
RAOB SUGS THERE WL BE NO LO CLDS. THERE WL BE A GUSTY S WIND THIS
MRNG UNDER H925 WINDS FCST UP TO 40-50KTS ON THE SRN FLANK OF PRES
FALL PASSING OVER LK SUP. SINCE THE LLVL FLOW IS FCST TO VEER MORE
TO THE W THRU THE DAY FOLLOWING THE PASSAGE OF A SFC WARM FNT...
PREFER TO TREND MAX TEMPS TOWARD THE WARMER GFS MOS. IN FACT...
MIXING TO JUST H9 ON THE GFS FCST SDNGS YIELDS HI TEMPS PEAKING IN
THE 50S OVER MUCH OF THE W HALF OF THE CWA...SEVERAL DEGREES HIER
THAN SHOWN BY THE MOS FCST. A MORE PERSISTENT SW LLVL FLOW OVER THE
E CLOSER TO THE DEPARTING COLD AIR AND BLOWING OFF THE COOL WATERS
OF LK MI WL HOLD TEMPS IN THE 40S IN THAT AREA. THE MORE WLY FLOW WL
ALSO KEEP THE KEWEENAW A BIT COOLER. GOING FCST HI TEMPS NEED LTL
ADJUSTMENT.
TNGT...UNDER BLDG UPR RDG...THE PRES GRADIENT IS FCST TO SLACKEN
QUITE A BIT...ALLOWING FOR MUCH LIGHTER WINDS. UNDER A MOCLR SKY...
EXPECT A HEALTHY DIURNAL TEMP FALL...WITH TEMPS FALLING TOWARD THE
LO END OF GUIDANCE GIVEN THE DRYNESS OF THE BISMARCK RAOB.
SUN...EXPECT ANOTHER MOSUNNY...WARM DAY WITH UPR RDG OVHD AND H85
TEMPS ARND 8C. SOME HI CLDS WL ARRIVE FM THE SW LATER IN THE DAY IN
ADVANCE OF UPR LO LIFTING OUT FM THE DESERT SW. MIXING TO JUST H9 ON
GFS FCST SDNGS WOULD RESULT IN HI TEMPS PEAKING NEAR 60 OVER AT
LEAST THE INTERIOR W HALF. BUT IN CONTRAST WITH TDAY THOUGH...THE
PRES GRADIENT WL BE RATHER WEAK...ALLOWING FOR LK BREEZE FORMATION/
COOLING NEAR THE SHORES. WITH THE PREVAILING SW FLOW...AREAS OVER
THE E DOWNWIND OF LK MI WL BE COOLER AS WELL.
SUN NGT...EXPECT THICKENING CLDS AS NEGATIVELY TILTED SHRTWV APRCHS
FM THE SW. THE EVNG WL BE DRY WITH LINGERING LLVL DRY AIR...BUT
ARRIVAL OF DEEPER MSTR/UPR DVGC IN EXIT REGION OF SUPPORTING H3 JET
MAX/H85-7 FGEN AFT 06Z WL BRING THE THREAT OF RA IN FM THE SW. THERE
ARE NO PTYPE WORRIES WITH THIS EVENT GIVEN UNSEASONABLE WARMTH OF
THE AIRMASS. ALTHOUGH INITIAL DRYNESS OF THE LLVLS WL INHIBIT FOG
FORMATION... LLVL MSTR SURGE FCST AFT 06Z WL BRING IN SOME FOG OVER
MELTING SN PACK...ESPECIALLY IN AREAS OVER THE CNTRL THAT UPSLOPE
WITH LLVL SE WIND.
.LONG TERM...(MODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST SAT MAR 10 2012
UPPER LOW PULLING OUT OF THE SW STATES TONIGHT WILL APPROACH THE
AREA ON SUN NIGHT AND CROSS THE GREAT LAKES REGION ON MON. AT THE
SFC...BROAD TROUGH FROM A LOW CENTERED OVER THE CANADIAN ROCKIES
WILL PUSH NE ACROSS THE AREA ON MON. MODELS SEEM TO HAVE COME INTO
DECENT AGREEMENT ON TIMING/TRACK OF THE UPPER LOW...WHICH LEADS TO
ABOVE NORMAL CONF ON PCPN TIMING.
MAIN PCPN OUT AHEAD OF THE UPPER LOW AND ASSOCIATED WITH THE BEST
H925-700 WAA AND 290-300K ISENTROPIC ASCENT MOVES NE ACROSS THE CWA
LATE SUN NIGHT INTO MON MORNING. THIS WILL LIKELY BRING THE BULK OF
THE PCPN WITH THE SYSTEM. COULD SEE A BRIEF BREAK IN THE LATE
MORNING AND EARLY AFTN AS MID LVL DRY AIR PUSHES THROUGH BEFORE THE
UPPER LOW MOVES OVERHEAD IN THE AFTN AND INCREASES MOISTURE AGAIN.
THIS PRODUCES ANOTHER SURGE OF SHOWERS...ESPECIALLY OVER THE WRN
HALF OF THE CWA. POTENTIAL STORMS OVER THE CNTRL/SRN MISS VALLEY
WILL LIKELY KEEP SOME OF THE DEEPER MOISTURE FROM MAKING IT INTO THE
UPPER GREAT LKS. BUT THE WARM/MOIST AIR FROM THE GULF WILL PRODUCE
PWATS NEAR 300 PERCENT OF NORMAL WITH THE WAA/ISENTROPIC ASCENT
AHEAD OF THE UPPER LOW. THUS...EXPECT AROUND 0.2-0.3IN OF RAIN WITH
THE INITIAL SURGE OF WAA. FELT THE EXISTING POPS IN THE DEFINITE
CATEGORY WERE GOOD FOR THE MORNING AND JUST TRIED TO ADD SOME
ADDITIONAL TIMING FOR THE DRY SLOT TOWARDS MID DAY AND BETTER
CHANCES OVER THE W IN THE AFTN.
WITH THE MELTING SNOW...RAIN...AND ABUNDANT LLVL MOISTURE...WILL
CONTINUE TO MENTION AREAS OF FOG FOR MON MORN. BUT HAVE TAPERED IT
OFF HEADING INTO THE AFTN...AS BUFKIT SOUNDINGS SHOWING LLVL MIXING
DIMINISHING THE POTENTIAL. DID LEAVE THE FOG IN OVER THE E WITH THE
SW FLOW AND WARM/MOIST AIR OVER LK MI...MAINLY E OF A LINE FROM
MUNISING TO ESCANABA.
MON NIGHT...WITH SFC TROUGH AND UPPER LOW QUICKLY MOVING NE ON MON
NIGHT...HIGH PRESSURE RIDGE WILL START TO EDGE INTO THE AREA
OVERNIGHT MON FROM SRN MN. WILL LIKELY STILL SEE SOME WRAP AROUND
SHOWERS IN THE EVENING FROM THE UPPER LOW ENERGY...BUT WILL DIMINISH
FROM SW TO NE WITH THE UPPER LOW QUICKLY MOVING NE. THIS QUICK
MOVEMENT...ALONG WITH THE HIGH PRESSURE RIDGE...WILL LEAD TO A SHARP
CLEARING LINE MOVING IN OVERNIGHT. ONE ITEM OF NOTE IS THE NAM
SHOWING LLVL MOISTURE BELOW THE DEVELOPING INVERSION AT 2.5KFT.
COULD LEAD TO SOME LINGERING FOG OR LOW CLOUDS BEHIND THE EXITING
UPPER LOW. GFS IS NOT AS PRONOUNCED AND WITH THE NAM TENDING TO
OVERDO LLVL MOISTURE...WILL LEAVE OUT OF THE FCST AT THIS TIME.
DAYS 4 THROUGH 7 /TUES THROUGH FRIDAY/...
UPPER TROUGH AMPLIFYING OVER THE CENTRAL/ERN CONUS WILL LEAD TO A
WARM/DRY DAY ON TUES AS A SFC HIGH SLIDES ACROSS THE CWA. COULD LEAD
TO SOME LK BREEZES DEPENDING ON THE TIMING OF THE SFC RIDGE MOVING
THROUGH. BUT AT THIS FAR OUT...WILL NOT TRY TO GET TOO FANCY ON
TEMPS/WINDS ALONG LK SUPERIOR. AS FOR HIGHS...MIXING TOWARDS
H875 YIELDS HIGHS IN THE UPPER 50S TO NEAR 60 ALONG THE WI BORDER.
HAVE KEPT TEMPS IN THE 40S NEAR GRAND MARAIS...WHERE NW WINDS OFF LK
SUPERIOR WILL LINGER INTO THE EARLY AFTN HRS AND LIMIT WARMING.
HIGH SHIFTS E TUES NIGHT AND WED. SHORTWAVE IN THE NRN STREAM
UPPER FLOW RUNNING FROM THE PAC NW TO HUDSON BAY WILL SWEEP A COLD
FRONT ACROSS THE AREA ON WED AFTN. MAIN ENERGY FROM THE
SHORTWAVE AND THE COLD FRONT REMAINS WELL NNW OF THE AREA IN NRN
ONTARIO. THIS...COMBINED WITH LIMITED MID LVL MOISTURE...THINK THE
PCPN CHANCES ARE LOW. BUT...DID LEAVE SLIGHT CHANCES OVER THE SE
HALF OF THE CWA...AS ECMWF/GEM/GFS TRY TO PULL MLCAPE VALUES
TOWARDS 200 J/KG. ML LAPSE RATES ARE FAIRLY STRONG...AROUND
7-8C/KM...BUT THE MID LVL DRY AIR AND CAP NEAR H850 WILL LIKELY
KEEP DEVELOPMENT FROM OCCURRING. BEST CHANCES WILL BE S OF THE
CWA...IN THE SE HALF OF WI...BUT FELT KEEPING THE SLIGHT CHANCES IN
NEAR THE WI BORDER WAS REASONABLE. MIXING AGAIN TO NEAR H875 /9C/ ON
WED WILL PRODUCE HIGHS IN THE LOW/MID 60S AWAY FROM THE COOLER FLOW
OFF LK MI. STRONGER SW FLOW AHEAD OF THE COLD FRONT WILL LIMIT
CONCERNS OF COOLING DUE TO LK BREEZES NEAR LK SUPERIOR. THIS SWRLY
FLOW WILL LIKELY LEAD TO DOWNSLOPE WARMING NEAR LK SUPERIOR...SO
HAVE BUMPED TEMPS UP SOME IN THOSE AREAS.
COLD FRONT SLIDES E ON WED NIGHT AND COULD LEAD TO A SLIGHT COOL
DOWN ON THURS. ECMWF/GEM KEEP IT WARM IN THE 50/60S WHILE THE GFS
HAS IN THE 40S. HAVE TRENDED TOWARDS THE WARMER ECMWF...SINCE IT
TRADITIONAL PERFORMS MUCH BETTER IN WELL ABOVE NORMAL PATTERNS AND
DUE TO THE COLD BIAS OF THE GFS. THUS...HAVE TEMPS IN THE
50S...EXCEPT OVER THE KEWEENAW AND NEAR LK SUPERIOR OVER THE NCTNRL
AND E...WHERE LIGHT WINDS OFF LK SUPERIOR WILL KEEP TEMPS COOLER.
OTHERWISE...UPPER RIDGE REMAINS IN PLACE INTO NEXT WEEKEND. THIS
WILL CONTINUE TO PRODUCE WARM/DRY WX FOR THE UPPER GREAT LKS. MODELS
ARE TRYING TO SHOW THE UPPER TROUGH THAT WILL HAVE BEEN STATIONED IN
THE PACIFIC OFF THE W COAST OVER THE NEXT 7 DAYS TO TRY AND MOVE
INLAND THIS WEEKEND...AMPLIFYING THE RIDGE EVEN FURTHER. AS THIS
TROUGH CONTINUES E NEXT WEEK...COULD SEE A TRANSITION TO A LITTLE
MORE ACTIVE WX AND MORE NORMAL TEMPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1226 AM EST SAT MAR 10 2012
IN THE WAKE OF SFC HIGH PRES RIDGE QUICKLY EXITING TO THE E...
RAPIDLY DEVELOPING WAA REGIME IS LEADING TO A BAND OF MID CLOUDS
MOVING ACROSS THE AREA. SINCE LOW-LEVELS WILL REMAIN DRY...VFR
CONDITIONS WILL CONTINUE AT KIWD/KCMX/KSAW THRU THIS FCST PERIOD.
OTHERWISE...S WINDS WILL CONTINUE TO INCREASE OVERNIGHT UNDER
SHARPENING PRESSURE GRADIENT BTWN THE DEPARTING HIGH PRES RIDGE AND
A LOW PRES SYSTEM MOVING THRU SCNTRL CANADA. NOCTURNAL INVERSION
SHOULD BE STRONG ENOUGH TO RESULT IN LLWS...ESPECIALLY AT SAW/CMX.
WITH IWD MORE EXPOSED TO S WINDS...LLWS MAY OCCUR THERE AT TIMES IN
BETWEEN GUSTY PERIODS. GUSTY WINDS ARE EXPECTED AT ALL SITES DURING
THE MORNING. HIGHEST GUSTS...AROUND 35KT...SHOULD OCCUR AT KSAW
UNDER FAVORABLE S WIND. WINDS WILL DIMINISH SLOWLY FROM W TO E IN
THE AFTN...WITH LIGHT WINDS EXPECTED BY EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 AM EST SAT MAR 10 2012
EXPECT A S GALE UP TO 40 KTS OVER THE E HALF OF LK SUP INTO THIS
AFTERNOON UNDER TIGHTENING PRES GRADIENT BETWEEN DEPARTING HI PRES
TO THE SE AND LO PRES MOVING ACROSS SOUTHERN CANADA. THE ARRIVAL OF
A WEAKER PRESSURE GRADIENT WILL CAUSE DIMINISHING WINDS LATER TODAY
THRU SUN.
AN UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE UPPER GREAT LAKES
ON MONDAY AND EXIT ON MONDAY NIGHT...ALLOWING A HIGH PRESSURE RIDGE
TO MOVE OVER THE AREA ON TUESDAY. WINDS DURING THIS PERIOD SHOULD
STAY BELOW 25KTS. A COLD FRONT FROM A LOW IN NRN ONTARIO WILL BRUSH
THE AREA ON WEDNESDAY. STRONG SOUTHERLY WINDS AHEAD OF THIS FRONT
SHOULD PRODUCE WINDS IN THE 20-25KT RANGE. THINK THE MARINE LAYER
WILL LIMIT POTENTIAL FOR HIGHER WINDS ALOFT TO REACH THE SFC.
&&
.HYDROLOGY...
ISSUED AT 400 AM EST SAT MAR 10 2012
LITTLE HAS CHANGED ON THE HYDROLOGY FRONT OVER THE LAST COUPLE
DAYS. STILL EXPECT WELL ABOVE NORMAL TEMPS OVER THE NEXT 7
DAYS...WHICH WILL TAKE A SIGNIFICANT BITE OUT OF THE SNOW PACK...IF
NOT EATING ALL OF IT.
TRADITIONALLY NEED ABOUT 2 DAYS OF TEMPERATURES IN THE MID-UPPER 40S
OR ABOVE AND TD/S ABOVE FREEZING TO RIPEN THE SNOWPACK. WARM TEMPS
EARLIER THIS WEEK DID JUST THAT OVER MUCH OF THE AREA...ALTHOUGH THE
COOL DOWN OVER THE LAST TWO DAYS HELPED SLOW/END THE MELT.
THUS...WITH THE TEMPS THIS WEEKEND EXPECTED TO EXCEED THAT...SHOULD
EASILY HAVE A RIPE SNOWPACK FOR MELTING THIS WEEKEND. THE RIPE
SNOWPACK WILL BE AIDED BY RAIN EXPECTED LATE SUN NIGHT AND INTO
MON...WHICH IS EXPECTED TO PRODUCE BETWEEN 0.25-0.40IN OF
PRECIPITATION. THEREFORE...EXPECT TO SEE RIVERS START TO RISE
SUN INTO MON AND CONTINUE THROUGH THIS WEEK UNTIL THE SNOW IS
MELTED. OVERNIGHT LOWS DON/T LOOK TO GET BELOW FREEZING AFTER
TONIGHT...SO SHOULD SEE A FAIRLY STEADY MELT. WILL LIKELY SEE SNOW
PACK GONE OVER MUCH OF THE AREA BY THE END OF THIS WEEK...EXCEPT FOR
WOODED/SHADED LOCATIONS.
WITH THIS FAIRLY FAST MELT AND RUNOFF...EXPECT SOME OF THE RIVERS
ACROSS THE AREA TO EXCEED THEIR BANKS BY THE END OF NEXT WEEK.
PERSONS LIVING NEAR RIVERS AND STREAMS SHOULD MONITOR THE LATEST
RIVER CONDITIONS AND USE CAUTION IF WALKING ALONG RIVER
BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
FINALLY...NOT MUCH ICE HAS BEEN NOTED BY OBSERVERS ON THE FASTER
FLOWING RIVERS OVER NRN UPPER MI. BUT THE FORD RIVER...BOTH AT HYDE
AND THE MOUTH AT LK MI...STILL HAS A GOOD ICE COVER THAT LEADS TO
SOME CONCERN FOR ICE JAM POTENTIAL WITH THE FASTER RUNOFF. ALTHOUGH
LIMITED SNOW WAS NOTED NEAR LK MI...THERE IS STILL 5-10IN OF SNOW
AND NOHRSC ESTIMATED AROUND 1.5IN OF LIQUID TOWARDS THE HEADWATERS
THAT WILL MELTED OVER THE COMING DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LSZ249>251-266-
267.
LAKE MICHIGAN...
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LMZ248-250.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LMZ221.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON/KC
MARINE...KC
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS BILLINGS MT
356 AM MST SAT MAR 10 2012
.SHORT TERM...VALID FOR TDY AND SUN...
WINDS IN THE UPPER YELLOWSTONE AND UPPER STILLWATER RIVER VALLEYS
HAVE WEAKENED AS SURFACE PRESSURES INCREASE LEE OF THE
DIVIDE...AND HAVE CANCELLED THE WIND ADVISORY FOR THESE AREAS.
RIDGE ALOFT WILL KEEP SUNNY AND DRY CONDITIONS ACROSS THE AREA
TODAY. LATEST RUC FORECASTS MIXING TO 600MB TODAY WHICH SHOULD BE
ENOUGH TO SEE WIDESPREAD HIGHS IN THE UPPER 60S TO MID 70S TODAY.
TEMPERATURES IN BILLINGS AND MILES CITY WILL BE CLOSE TO RECORD
LEVELS TODAY WHICH WOULD BE TWO DAYS IN A ROW FOR MILES CITY.
WINDS TODAY WILL BE MUCH WEAKER THAN FRIDAY WITH SOME MODELS
SHOWING WINDS BECOMING LIGHT ACROSS THE AREA THIS AFTERNOON. WITH
SUNNY CONDITIONS AND TEMPERATURES THIS WARM HOWEVER WILL LIKELY
SEE SOME AFTERNOON THERMAL WIND GUSTS IN THE 25 MPH RANGE. RIDGE
BEGINS TO BREAK DOWN SUNDAY WITH UPPER FLOW INCREASING AND
TURNING SOUTHWESTERLY AS NEXT PACIFIC SYSTEM MOVES INTO THE WEST
COAST. MODELS ONCE AGAIN SHOW GOOD MIXING ALONG WITH PLENTY OF
SUN FOR SUNDAY WHICH SHOULD ONCE AGAIN PUSH TEMPERATURES TOWARD
RECORD LEVELS ACROSS THE AREA. MIXING ACROSS WESTERN ZONES MAY
PULL DOWN SOME PRETTY GUSTY WINDS FROM ALOFT IN THE AFTERNOON AND
BUMPED WIND SPEEDS UP TO WINDY CATEGORY FOR THESE AREAS. PACIFIC
COLD FRONT LOOKS TO MOVE THROUGH THE AREA LATE SUNDAY NIGHT INTO
MONDAY MORNING. WHILE THERE IS A DECENT PUSH OF PACIFIC MOISTURE
WITH THIS SYSTEM...MOST OF THE ENERGY PIVOTS TO THE NORTH OF THE
FORECAST AREA KEEPING DOWNSLOPE WIND GRADIENT IN PLACE. AS A
RESULT HAVE ONLY CHANCE POPS IN PLACE FOR WESTERN ZONES FOR NOW
WITH THIS SYSTEM.
FIRE WEATHER...WITH THE UNSEASONABLY WARM AND DRY CONDITIONS FIRE
CONCERNS ARE HEIGHTENED ACROSS THE AREA. STRONG MIXING AND
OCCASIONAL THERMAL WIND GUSTS TO 25 MPH COULD RESULT IN INCREASED
FIRE BEHAVIOR TODAY. SOUTHWEST WINDS SUNDAY WILL BE STRONGER
AHEAD OF THE NEXT STORM SYSTEM WHICH MAY RESULT IN DIFFICULT
CONTROL CONDITIONS WEST OF A ROUNDUP TO SHERIDAN LINE SHOULD A
FIRE DEVELOP. CONDITIONS TODAY DO NOT WARRANT ANY FIRE HIGHLITES
BUT SUNDAY WILL HAVE TO BE LOOKED AT CLOSELY FOR WESTERN FIRE
ZONES. ANYONE PLANNING TO BURN THIS WEEKEND SHOULD TAKE EXTRA
PRECAUTIONS DUE TO THE WARM AND DRY CONDITIONS. CHAMBERS
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
DID NOT MAKE MANY CHANGES TO GOING FORECAST AS MODELS HAVE BEEN
CONSISTENT WITH UPCOMING PATTERN. A SHORTWAVE WILL ROTATE NE THROUGH
THE REGION ON MON WHILE ITS ASSOCIATED COLD FRONT WEAKENS OVER THE
AREA. PULLED BACK THE POPS TO JUST THE WESTERN MOUNTAINS AS THIS
WEAKENING TREND HAS BEEN CONSISTENT FOR AWHILE. SW FLOW WILL THEN
OVERTAKE THE AREA BEFORE ANOTHER WAVE MOVES THROUGH N MT TUE NIGHT.
THE WAVE WILL DRAG A COLD FRONT THROUGH THE AREA. KEPT THE GOING
POPS W OF KBIL ON TUE AND OVER A LARGE PORTION OF THE AREA TUE
NIGHT. WEAK UPPER RIDGING/SW FLOW WILL BRING JUST A CHANCE OF
PRECIPITATION TO THE WESTERN MOUNTAINS WED THROUGH FRI. THE NEXT
PACIFIC TROUGH TAKES SHAPE FRI NIGHT AND MODELS DIFFERED IN HOW THEY
HANDLED THE EVOLUTION OF THE SYSTEM THROUGH THE END OF THE PERIOD.
THE GFS SWINGS ENERGY NE THROUGH THE AREA...WHILE THE ECMWF KEEPS
THE TROUGH OFF TO THE W. HAD LOW POPS FROM KBIL W FRI NIGHT...THEN
DUE TO THE LARGE UNCERTAINTY WITH THE PATTERN EVOLUTION...WENT WITH
CLIMATOLOGY POPS FOR SAT AND SAT NIGHT. WITH NO COLD AIR IN
SIGHT...ABOVE NORMAL TEMPERATURES WILL CONTINUE. AT THIS TIME...THE
WARMEST DAYS APPEARED TO BE ON THU AND FRI WITH HIGH TEMPERATURES
EXPECTED TO BE WELL INTO THE 60S. ARTHUR
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL TODAY AND TONIGHT OVER THE AREA. EXPECT
GUSTY SW SURFACE WINDS AT 20 TO 30 KT OVER KLVM AND THE BEARTOOTH
FOOTHILLS THIS MORNING. ARTHUR
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 070 040/068 036/056 039/064 036/060 040/067 042/068
0/U 00/B 11/B 11/N 20/B 00/B 11/B
LVM 063 038/063 030/049 037/059 029/055 032/061 034/057
0/N 00/N 31/N 12/W 20/B 00/B 11/B
HDN 070 036/069 034/057 035/065 034/064 038/066 043/068
0/U 00/U 10/B 00/N 20/B 00/B 00/U
MLS 071 036/071 036/055 037/067 035/058 038/065 043/069
0/U 00/U 10/B 00/B 20/B 00/B 00/U
4BQ 071 035/069 035/058 036/065 036/062 036/065 039/069
0/U 00/U 00/B 00/B 00/B 00/U 00/U
BHK 070 036/069 035/055 034/064 033/059 037/064 041/068
0/U 00/U 00/U 00/B 00/B 00/U 00/U
SHR 067 033/066 031/056 035/063 034/058 033/062 040/062
0/U 00/U 00/B 00/B 00/B 00/U 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
653 PM CDT SUN MAR 11 2012
.SHORT TERM UPDATE...
BASED ON RADAR AND RECORDED PRECIPITATION AMOUNTS...WE HAVE
UPDATE THE FORECAST FOR TONIGHT FOR HIGHER PROBABILITY OF
PRECIPITATION AND SLIGHTLY HIGHER PRECIPITATION AMOUNTS FOR THIS
EVENING IN NORTH CENTRAL THROUGH SOUTHWEST NEBRASKA EAST OF A LINE
FROM VALENTINE THROUGH MULLEN AND OGALLALA TO IMPERIAL.
&&
.AVIATION...
AS THE STORM SYSTEM MOVES OUT LATE THIS EVENING AND RAINSHOWERS
MOVE OFF TO THE EAST...CEILING AND VISIBILITY WILL IMPROVE OVER
NORTH CENTRAL THROUGH SOUTHWEST NEBRASKA. WITH THE SYSTEM MOVING
EAST-NORTHEAST...IT APPEARS THAT THE AREA NORTH AND WEST OF A
VTN-MHN-OGA-IML LINE WILL HAVE LITTLE OR NO PRECIPITATION AND ONLY
VFR CEILINGS AT WORST.
WIND IS EXPECTED TO SHIFT TO THE NORTHWEST 08-10Z AND INCREASE
MONDAY MORNING 14-16Z AND BECOME NORTHWEST 290-320 AT 14-18G24-28KT.
&&
.PREV DISCUSSION... /ISSUED 310 PM CDT SUN MAR 11 2012/
DISCUSSION...
THE UPPER LEVEL LOW ACROSS ERN COLO/WRN KS WILL LIFT SLOWLY NORTHEAST
THRU ERN NEB OVERNIGHT. CURRENT RADAR TRENDS AND THE RUC SUGGEST
ISOLATED SHOWERS THIS EVENING AS FAR WEST AS SWRN NEB WHICH THEN
SPREAD NORTHEAST OVERNIGHT AND EXIT THE FCST AREA BY ROUGHLY 12Z
MONDAY.
ANOTHER BIG FIRE DAY IS POSSIBLE MONDAY. BLENDED BIAS CORRECTED
MET MAV DEW PT DATA POINTS TOWARD DEW POINTS IN THE UPPER TEENS.
MEANWHILE THE STRONGER MAV WINDS AND ASSOCIATED DEEPER MIXING
PRODUCES STRONGER WINDS. SO RED FLAG CONDITIONS ARE POSSIBLE
ACROSS A LARGE PART OF THE FCST AREA. GREATER FIRE DANGER COULD
DEVELOP TUESDAY AS LOW PRESSURE ACROSS ALBERTA AND SASKATCHEWAN
DEEPENS TO AROUND 985 MB. A DRY LINE IS FCST TO DEVELOP AND PUSH
EAST TO AROUND HIGHWAY 183 WITH WINDS GUSTING TO 25 TO 30KTS. ON
WEDNESDAY CANADIAN LOW PRESSURE WILL FORCE THE DRY LINE FARTHER
EAST TO NEAR OMAHA WHICH COULD ALSO PRODUCE CRITICAL FIRE DANGER.
TEMPERATURES CONTINUE TO SOAR IN ALL MODEL SOLNS THROUGH WEDNESDAY.
THE CANADIAN LOW PRESSURE SYSTEMS WILL TRACK FAR ENOUGH NORTH TO
PREVENT ANY KIND OF STRONG COLD FRONTS AND COOLER TEMPS FROM
MOVING THROUGH THE FCST AREA BUT IT APPEARS THE SYSTEMS WILL BE
STRONG ENOUGH TO PREVENT THE DRY LINE FROM BACKING UP VERY FAR
WEST. THIS IS VERY UNCERTAIN AT THIS POINT AS WE HAVE YET TO SEE
THIS TYPE OF PATTERN AND IN WET YEARS THE DRY LINE TENDS TO HANG
OUT AROUND HIGHWAY 61.
THE GFS CONTINUES TO INDICATE SOME CIRRUS TUESDAY AND WEDNESDAY
BUT THIS SHOULD BE A FAIRLY THIN VEIL AND HAVE ONLY MINOR IMPACT ON
MAX TEMPS.
THURSDAY THROUGH SUNDAY...THE ECM CONTINUES TO KEEP A DEVELOPING
LONG WAVE TROF WEST OF THE FCST AREA. WITH NO SIGNIFICANT NRN
STREAM LEAD SHORT WAVE...THE FCST AREA SHOULD REMAIN IN THE WARM
SECTOR. A SERIES OF LOW PRESSURE SYSTEMS LIFT OUT OF THE TROF AND
THROUGH THE ROCKIES AND HIGH PLAINS. EACH WILL SUBSEQUENTLY DRAW
HIGH PRESSURE AND COOLER TEMPS CLOSER TO THE FCST AREA. THE
EARLIEST WE MIGHT SEE COOLING IS NEXT SUNDAY WHEN WINDS MAY BACK
AROUND TO THE EAST IN RESPONSE TO DEEP LOW PRESSURE ACROSS ERN WY.
THE GFS IS FASTER BRINGING THE LONG WAVE TROF EAST QUICKER. THE
FCST LEANS TOWARD THE SLOWER ECM AND WARMER TEMPS.
THERE IS SOME SPREAD IN THE POSITION OF A VERY STRONG DRY LINE FCST
TO DEVELOP ACROSS CNTL NEB IN THE EXTENDED FCST. ALL SOLNS INDICATE
DEW POINTS IN THE 50S ACROSS ERN NEB WITH 20S OVER WRN NEB. THESE
DIFFERENCES APPEAR TO BE RELATED TO THE TIMING...LOCATION AND
INTENSITY OF THE DISTURBANCES LIFTING OUT OF THE LONG WAVE TROF.
THE MODELS APPEAR TO BE DEVELOPING A BROAD AREA OF NOCTURNAL
STRATUS IN THE DEEPER MOISTURE EAST OF THE DRY LINE SO THE POSITION OF THE
DRY LINE WILL BE CLOSELY WATCHED. LATER MODEL SOLNS MAY SHOW THE
DRY LINE BACKING UP WESTWARD TOWARD A MORE CLIMATOLOGICAL
LOCATION.
FIRE WEATHER...
A FIRE WEATHER WATCH HAS BEEN ISSUED FOR FIRE ZONES
204...206...209...210 AND 219 MONDAY AFTERNOON. THE COMBINATION OF
CURED FUELS...WEST NORTHWESTERLY DOWNSLOPING WIND...AND ABNORMALLY
WARM TEMPERATURES WILL CREATE CONDITIONS FAVORABLE FOR EXTREME FIRE
GROWTH. ONE CAVEAT HOWEVER...WIND SPEEDS MAY BE MARGINAL /BELOW RFW
CRITERIA/ AS HIGH PRESSURE BUILDS OVER THE REGION. BUT EMPLOYING
THE USE MAV GUIDANCE WOULD INDICATE THE POTENTIAL FOR GUSTS OF 25
MPH FOR A THREE TO FOUR HOUR PERIOD EARLY MONDAY AFTERNOON. BUFR
SOUNDINGS AND OTHER GUIDANCE INDICATE A WEAKER WIND PROFILE...WITH
THE NAM GOING AS FAR AS TO SUGGEST WIND SPEEDS OF LESS THAN 20 KTS
AT 700MB OVER MUCH OF THE CWA BY 21Z CONSIDERING THAT THE MODELS
INDICATE A RELAXING PRESSURE GRADIENT...PEAK WIND SPEEDS MAY NOT
CORRESPOND WITH PEAK HEATING/MINIMUM RH. HOWEVER...THE MODELS
GENERALLY HAVE STRUGGLED RECENTLY AND UNDERESTIMATED NOT ONLY WIND
SPEEDS BUT ALSO TEMPERATURES/RH VALUES DURING PEAK HEATING...FELT
THAT CONFIDENCE WAS HIGH ENOUGH FOR AT LEAST A FIRE WEATHER WATCH AT
THIS TIME. WILL INCLUDE MOST OF WESTERN AND NORTH CENTRAL NEBRASKA
IN THIS WATCH THAT WILL BE IN EFFECT FROM 17Z MONDAY UNTIL 01Z
TUESDAY.
FIRE HEADLINES MAY BE NEEDED FOR THE REMAINDER OF NEXT WEEK AS
RIDGING BUILDS OVER THE CENTRAL AND NORTHERN PLAINS. TEMPERATURES
BEYOND MONDAY SHOULD REMAIN IN THE 70S FOR HIGHS THROUGH THE END OF
THE WORK WEEK. IN FACT...TEMPERATURES TUESDAY THROUGH THURSDAY MAY
APPROACH 80 DEGREES ALONG AND SOUTH OF THE INTERSTATE 80
CORRIDOR...AND ACROSS MUCH OF THE CENTRAL/NORTHERN SAND HILLS. WITH
CURED FUELS IN PLACE...THESE ABOVE NORMAL TEMPERATURES WILL COMBINE
WITH MEAGER ATMOSPHERIC MOISTURE AND AT TIMES GUSTY WIND SPEEDS TO
CREATE CONDITIONS FAVORABLE FOR EXTREME FIRE BEHAVIOR. ALL FIRE
INTERESTS SHOULD MONITOR THIS SITUATION CLOSELY UNTIL APPRECIABLE
MOISTURE FALLS OR GREEN UP OCCURS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR NEZ204-206-209-210-219.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION/SHORT TERM UPDATE...SPRINGER
AREA FORECAST DISCUSSION
NWS HASTINGS NE
336 AM CST SAT MAR 10 2012
.SHORT TERM...TODAY THROUGH 12Z TUESDAY. MAIN FORECAST CONCERNS
WILL BE FIRE WEATHER THIS AFTERNOON...A CHANCE FOR SHOWERS TONIGHT
THROUGH SUNDAY NIGHT AND TEMPERATURES.
WARM DRY AIR CONTINUES ACROSS THE FORECAST AREA THIS MORNING WITH
BREEZY SOUTHWEST WINDS. THE WARM START TO THE DAY...PLENTY OF
SUNSHINE AND WARM ADVECTION WILL HAVE UNSEASONABLY WARM TEMPERATURES
ACROSS THE AREA FOR TODAY. BY THIS AFTERNOON THE FIRST SIGNS OF AN
APPROACHING UPPER LEVEL WAVE WILL SHOW UP WITH THE ARRIVAL OF SOME
CLOUDS. TONIGHT THE UPPER LOW CONTINUES TO APPROACH THE AREA AND
WITH THE ADDITIONAL MOISTURE ACROSS THE AREA THERE COULD BE SOME
SHOWERS STARTING IN THE SOUTH THIS EVENING AND SPREADING NORTH
THROUGH THE NIGHT.
ON SUNDAY THE UPPER LEVEL LOW MOVES THROUGH THE SOUTHEAST PART OF
THE FORECAST AREA. THE CHANCE FOR SHOWERS CONTINUES ACROSS THE AREA
ON SUNDAY...AND SLOWLY DIMINISHES SUNDAY NIGHT FROM SOUTHWEST TO
NORTHEAST DURING THE NIGHT AS THE UPPER LEVEL LOW MOVES TO THE
NORTHEAST. WITH CLOUDS AND SHOWERS AROUND TEMPERATURES WILL BE
COOLER ON SUNDAY.
WARM ADVECTION AND DRY AIR RETURNS TO THE CENTRAL PLAINS MONDAY
AND MONDAY NIGHT. A WEAK SURFACE HIGH PRESSURE SYSTEM MOVES
THROUGH THE AREA AND WINDS SHOULD BE LIGHTER THAN THEY HAVE BEEN.
TEMPERATURES WILL RETURN TO WELL ABOVE NORMAL ON MONDAY.
.LONG TERM...TUESDAY THROUGH FRIDAY. GUIDANCE CONTINUES TO
SUGGEST UPPER LEVEL RIDGING WILL DOMINATE MUCH OF THE LONG TERM
FORECAST PERIOD. THE RESULTANT LACK IN KINEMATIC FORCING WILL
PRESENT A DRY FORECAST THROUGH AT LEAST THURSDAY. THERE ARE SOME
INDICATIONS OF AN APPROACHING MID AND UPPER LEVEL TROUGH BRINGING
CHANCES FOR PRECIPITATION TO THE AREA TOWARDS THE END OF THE
CURRENT LONG TERM FORECAST PERIOD...AND SLIGHT CHANCE POPS ARE IN
PLACE ACROSS ROUGHLY THE SOUTHEASTERN HALF OF THE CWA FOR FRIDAY
AS A RESULT. WITH THE EXCEPTION OF A WEAK LOW LEVEL BAROCLINIC
ZONE CLEARING THE AREA ON WEDNESDAY...LOW LEVEL FLOW IS EXPECTED
TO REMAIN FROM THE SOUTH THROUGHOUT LONG TERM FORECAST
PERIOD...THUS PRESENTING CONTINUED LOW LEVEL WAA AND TEMPERATURES
WHICH ARE WELL ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.FIRE WEATHER...DRY AIR IS ALREADY IN PLACE ACROSS THE FORECAST
AREA TODAY. AS TEMPERATURES WARM UP THIS AFTERNOON EXPECT RELATIVE
HUMIDITY TO DROP OFF ESPECIALLY IN THE NORTH. MOISTURE IS EXPECTED
TO RETURN TO THE SOUTHERN PART OF THE FORECAST AREA THIS AFTERNOON
AND SHOULD KEEP RELATIVE HUMIDITIES A LITTLE HIGHER. WINDS WILL BE
FROM THE SOUTH TO SOUTHWEST AND SHOULD REACH 20 MPH DURING THE
DAY. WILL GO WITH A RED FLAG WARNING FOR THE NORTHERN COUNTIES FOR
THE AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 1126 PM CST FRI MAR 9 2012/
AVIATION...06Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE
NEXT 24 HOURS. MID LEVEL CLOUDS WILL BE POSSIBLE TOWARDS THE END
OF THE TAF PERIOD...BUT CEILINGS SHOULD HOLD OFF AT THE TERMINAL
UNTIL AFTER 11/06Z AND WILL LEAVE ANY MENTION OF MID LEVEL CLOUDS
OUT OF THE TAF FOR THE TIME BEING AS A RESULT. RUC ANALYSIS...LAPS AND
VWP FROM KUEX ALL INDICATE A SOUTHWESTERLY LOW LEVEL JET STREAK OF
40-45KTS EXISTING JUST ABOVE THE BOUNDARY LAYER AT AROUND 1000FT
AGL. ALTHOUGH SURFACE WINDS ARE ALSO SOMEWHAT STRONG...ENOUGH OF AN
INCREASE IN WIND SPEED EXISTS BETWEEN THE SURFACE AND 1000FT AGL THUS
JUSTIFYING THE INSERTION OF LLWS INTO THE TAF. SHORT TERM
GUIDANCE SUGGESTS THIS LOW LEVEL JET WILL REMAIN INTACT THROUGH
MUCH OF THE NIGHT...WITH LLWS ALSO REMAINING POSSIBLE UNTIL THE
BOUNDARY LAYER DEEPENS DURING THE DAY DAY SATURDAY THUS ALLOWING
FOR STRONGER WINDS AT THE SURFACE AND DIMINISHMENT OF LLWS.
VISIBILITY RESTRICTIONS ARE NOT EXPECTED AT THE TERMINAL THROUGH
THE NEXT 24 HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
NEZ039>041-046>049.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1126 PM CST FRI MAR 9 2012
.AVIATION...06Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE
NEXT 24 HOURS. MID LEVEL CLOUDS WILL BE POSSIBLE TOWARDS THE END
OF THE TAF PERIOD...BUT CEILINGS SHOULD HOLD OFF AT THE TERMINAL
UNTIL AFTER 11/06Z AND WILL LEAVE ANY MENTION OF MID LEVEL CLOUDS
OUT OF THE TAF FOR THE TIME BEING AS A RESULT. RUC ANALYSIS...LAPS AND
VWP FROM KUEX ALL INDICATE A SOUTHWESTERLY LOW LEVEL JET STREAK OF
40-45KTS EXISTING JUST ABOVE THE BOUNDARY LAYER AT AROUND 1000FT
AGL. ALTHOUGH SURFACE WINDS ARE ALSO SOMEWHAT STRONG...ENOUGH OF AN
INCREASE IN WIND SPEED EXISTS BETWEEN THE SURFACE AND 1000FT AGL THUS
JUSTIFYING THE INSERTION OF LLWS INTO THE TAF. SHORT TERM
GUIDANCE SUGGESTS THIS LOW LEVEL JET WILL REMAIN INTACT THROUGH
MUCH OF THE NIGHT...WITH LLWS ALSO REMAINING POSSIBLE UNTIL THE
BOUNDARY LAYER DEEPENS DURING THE DAY DAY SATURDAY THUS ALLOWING
FOR STRONGER WINDS AT THE SURFACE AND DIMINISHMENT OF LLWS.
VISIBILITY RESTRICTIONS ARE NOT EXPECTED AT THE TERMINAL THROUGH
THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 604 PM CST FRI MAR 9 2012/
UPDATE...RED FLAG WARNING WILL BE ALLOWED TO EXPIRE AT 6 PM AS
WINDS WILL BECOME LESS GUSTY THIS EVENING...AND RELATIVE
HUMIDITIES WILL INCREASE AS TEMPERATURES FALL WITH SUNSET.
PREV DISCUSSION... /ISSUED 344 PM CST FRI MAR 9 2012/
SHORT TERM...SUNDAY THROUGH FRIDAY. THE LEAST PLEASANT DAY OF THE
EXTENDED PERIOD WILL LIKELY BE ON SUNDAY WITH A SLOW MOVING
CLOSED OFF UPPER LOW TRACKING ACROSS OUR FORECAST AREA. THIS WILL
RESULT IN A GOOD DEAL OF CLOUD COVER AND AT LEAST A CHANCE OF RAIN
SHOWERS ON SUNDAY. IN ADDITION...SUNDAY AFTERNOON HIGH
TEMPERATURES WILL STRUGGLE INTO THE LOWER 50S...WHICH IS STILL
ABOVE NORMAL FOR THIS TIME OF YEAR...BUT MUCH COOLER THAN WHAT WE
WILL BE SEEING THE REST OF THE WEEK.
MONDAY...THE UPPER LOW IS EXPECTED TO HAVE MOVED OUT OF THE AREA
BY MONDAY AND WARM WESTERLY WINDS WILL DEVELOP. MONDAY HIGH
TEMPERATURES SHOULD BE VERY NICE RANGING FROM THE UPPER 60S TO THE
LOWER 70S.
TUESDAY THROUGH THURSDAY...DRY AND VERY MILD CONDITIONS WILL
PERSIST WITH HIGH TEMPERATURES IN THE UPPER 60S TO LOWER 70S.
OUR AREA WILL BE UNDER THE INFLUENCE OF FAIRLY WEAK SOUTHWESTERLY
FLOW ALOFT.
FRIDAY...THIS WILL MORE THAN LIKELY BE A DRY DAY...BUT THERE HAVE
BEEN A FEW MODEL RUNS THAT HAVE HINTED AT LEAST A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS. SEVERAL DAYS OF LOW LEVEL SOUTHERLY FLOW
MAY EVENTUALLY ALLOW FOR ENOUGH MOISTURE TO SQUEAK OUT A FEW
ISOLATED SHOWERS OR WEAK THUNDERSTORMS. THE ECMWF HAS BEEN
FLIPPING BACK AND FORTH ON FRIDAY PRECIP CHANCES WITH THE LATEST
12Z RUN INDICATING DRY CONDITIONS. CONFIDENCE ON PRECIPITATION
CHANCES FOR FRIDAY ARE FAIRLY LOW AND WILL JUST BE GOING WITH A
SLIGHT CHANCE.
LONG TERM...TONIGHT AND TOMORROW. PRIMARY FORECAST CONCERN LIES
WITH TEMPERATURES AND FIRE WEATHER CONCERNS TOMORROW.
UPPER LEVEL PROFILER AND SATELLITE DATA SHOWING NORTHWESTERLY FLOW
ACROSS THE REGION...WITH A TROUGH SHIFTING EAST THROUGH THE
GREAT LAKES AND A LOW PRESSURE SYSTEM SET UP OVER THE NM/AZ
BORDER. LITTLE/NO CLOUD COVER ACROSS THE CWA...AND LOOKING AT THE
SURFACE PATTERN...THE CWA SITS BETWEEN HIGH PRESSURE CENTERED OVER
THE MN/WI/IA BORDER AREA...AND A TROUGH OF LOW PRESSURE EXTENDING
SOUTH THROUGH THE HIGH PLAINS. A TIGHTENING PRESSURE GRADIENT AND
INCREASED MIXING HAS BROUGHT GUSTY SOUTHWESTERLY WINDS THIS
AFTERNOON...WITH SPEEDS BETWEEN 15 AND 25 MPH AND GUSTS ANYWHERE
FROM 20 TO 30 MPH. THE MIXING HAS ALSO ALLOWED FOR QUITE A DROP IN
DEWPOINTS...AND COMBINED WITH TEMPS IN THE MID 60S...LED TO FIRE
WEATHER CONCERNS. AREA SITTING IN THE RED FLAG WARNING WORKING OUT
PRETTY MUCH AS EXPECTED...AND LOCATIONS TO THE SOUTH ARE SEEING
SLIGHTLY LOWER WINDS.
THROUGH THE REST OF THE SHORT TERM PERIOD...MODELS IN GOOD
AGREEMENT WITH THE PATTERN ACROSS THE CONUS. MODELS NOT SHOWING
SIGNIFICANT CHANGES...THE SWRN CONUS UPPER LEVEL LOW DOESNT MAKE
MUCH PROGRESS...00Z SUNDAY IS ONLY SHIFTED INTO SCENTRAL NM.
EXPECTING DRY CONDITIONS THROUGH THE MAJORITY OF THE PERIOD...AS
SHORTWAVE RIDGING SETS UP ACROSS THE PLAINS AHEAD OF THE LOW. THE
EXCEPTION IS LATE TOMORROW AFTERNOON...WHERE SOME MODELS CONTINUE
TO HINT THAT PRECIPITATION STREAMING NORTH AHEAD OF THE LOW
MANAGES TO CREEP INTO THE SRN 3 COUNTIES...SO KEPT THE LOW POPS
GOING.
EXPECTING ANOTHER BREEZY AFTERNOON...MIXING POTENTIAL ISNT QUITE
AS GOOD TOMORROW...AN EVEN TIGHTER PRESSURE GRADIENT LOOKS TO
SET UP AS LOW PRESSURE SLIDES IN FROM THE NORTHWEST. RAISED WIND
SPEEDS INTO THE 20 TO 25 MPH RANGE...AND HIGHER GUSTS WILL
POSSIBLE. MODELS HAVE NOT DONE THE BEST WITH DEWPOINTS THE LAST
FEW DAYS...SO ITS HARD TO PUT A LOT OF CONFIDENCE INTO THEM FOR
TOMORROW...AND DID DROP THEM A FEW DEGREES. WITH ANOTHER DAY OF
HIGH TEMPERATURES IN THE 60S AND CURRENT FORECAST DEWPOINTS AND
WINDS...FIRE WEATHER WILL AGAIN BE A CONCERN TOMORROW AFTERNOON.
WILL HOLD OFF ON ANY FIRE WEATHER HEADLINES FOR NOW WITH RH VALUES
REMAINING ABOVE THAT 20 PERCENT MARK...BUT IT WILL BE SOMETHING
FOR THE MID SHIFT TO CLOSELY WATCH. WOULDNT TAKE MUCH OF AN UPWARD
SHIFT IN TEMPS OR DOWNWARD SHIFT IN DEWPOINTS TO REACH CRITICAL
LEVELS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...BRYANT
SHORT TERM...ADO
LONG TERM...WESELY
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1252 AM EST SAT MAR 10 2012
.SYNOPSIS...
A COLD NORTHWEST FLOW WILL PRODUCE LAKE EFFECT SNOW SHOWERS
SOUTHEAST OF LAKE ONTARIO INTO EARLY THIS MORNING. DRY...COLD
WEATHER IS EXPECTED THIS AFTERNOON THROUGH TONIGHT AS HIGH
PRESSURE BUILDS OVER THE AREA. UNSEASONABLY WARM WEATHER WILL
RETURN ON SUNDAY... WITH SEVERAL DAYS OF WARM WEATHER EXPECTED
THROUGH NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AT 930 PM...LOCAL RADARS SHOW WIDELY SCATTERED SNOW SHOWERS ACROSS
THE TWIN TIERS WITH WIDESPREAD ACTIVITY IN ONEIDA, MADISON AND
ONONDAGA COUNTIES. THE ACTIVITY CONTINUES TO DIMINISH IN BOTH
COVERAGE AND INTENSITY DUE TO LOSS OF DAYTIME HEATING EXCEPT FOR
THE LAKE EFFECT SNOW SHOWERS IN THE NRN CWA. SATELLITE SHOWS A
GEORGIAN BAY CONNECTION WHICH IS ENHANCING THE ACTIVITY. LOWERING
SUBSIDENCE INVERSION AND VEERING LOW LEVEL WINDS WILL GRADUALLY
MOVE THE ACTIVITY SOUTH WHILE IT WEAKENS. FOR NOW, INCREASED POPS TO
CATEGORICAL ACROSS MUCH OF ONEIDA/MADISON AND ONONDAGA COUNTIES.
AFTER MIDNIGHT THE MORE PERSISTENT SNOW SHOWERS WILL RESIDE ACROSS
ONONDAGA, SOUTHERN CAYUGA, NORTHERN CORTLAND AND NORTHERN CHENANGO
COUNTIES. IN GENERAL TOTAL SNOW ACCUMS OVERNIGHT WILL RANGE FROM 2
TO 4 INCHES IN THE ABOVE MENTIONED AREAS.
.PREVIOUS DISC...
500 MB TROUGH AND VORTICITY MAX WILL TRACK ACROSS AND
EAST OF THE AREA LATE THIS AFTERNOON INTO THIS EVENING. WIDESPREAD
SNOW SHOWERS WITH ISOLATED HEAVIER SQUALLS WILL DIMINISH LATE THIS
AFTERNOON WITH THE LOSS OF DIURNAL HEATING.
A WEAK SURFACE TROUGH OF LOW PRESSURE WILL DEVELOP FROM CENTRAL
NEW ENGLAND WNW BACK TOWARD LAKE ONTARIO THIS EVENING IN RESPONSE
TO THE SHORT WAVE MOVING EAST FROM NY ACROSS NEW ENGLAND. THAT TROUGH
ALONG WITH SOME LAKE ENHANCEMENT WITH A FLOW FROM AROUND 290
DEGREES AND 850 MB TEMP FROM -10 TO -12 SHOULD HELP TO ORGANIZE
SNOW SHOWERS SOUTHEAST OF THE LAKE IN THE MOHAWK VALLEY THIS
EVENING. VSBL SATELLITE IMAGERY OVER THE CENTRAL AND WESTERN GREAT
LAKES INDICATE THAT THE ATMOSPHERE IS CURRENTLY SUPPORTING SOME
WNW ORIENTED SNOW BANDS OVER MICHIGAN CURRENTLY... AND THESE
SHOULD TRANSLATE INTO OUR AREA THIS EVENING WITH SOME ENHANCEMENT
BY THE SURFACE TROUGH. SOUTH OF THESE BANDS EXPECT JUST A FEW
SCATTERED SNOW SHOWERS. THIS SCENARIO IS SUPPORTED BY THE HIGH
RESOLUTION HRRR AND 4 KM NAM.
THE FLOW WILL BECOME MORE NORTHWESTERLY OVERNIGHT SHIFTING TO
AROUND 320 TO 330 DEGREES AFTER MIDNIGHT. THAT SHOULD ALLOW SOME
LAKE EFFECT SHOWERS TO SHIFT SOUTH TOWARD THE FINGER LAKES
OVERNIGHT. OVERALL EXPECT SNOW AMOUNTS TONIGHT SOUTHEAST OF LAKE
ONTARIO TO BE LIGHT AS TEMPERATURES WILL ONLY BE MARGINALLY COLD
ENOUGH FOR LAKE EFFECT... WINDS WILL NOT BE VERY STRONG AND THE
INVERSION WILL BE LOWERING. NIGHT-TIME ACCUMULATIONS OF 1 TO 4
INCHES ARE EXPECTED WITH HIGHEST AMOUNTS PROBABLY IN THE HILLS
SOUTH SYRACUSE AND MOHAWK VALLEY. CONCERN WOULD BE FOR LOCALLY
HEAVIER AMOUNTS IN THE MOHAWK VALLEY IN ASSOCIATION WITH THE
SURFACE TROUGH... BUT EXPECT THAT THIS BAND WILL NOT ORGANIZE
EARLY ENOUGH TO PERSIST FOR LONG BEFORE IT SHIFTS TO THE SOUTH
WITH THE WIND SHIFT TO NORTHWEST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
VERY QUIET WEATHER EXPECTED DURING THIS PERIOD. ANY FLURRIES
SOUTHEAST OF THE FINGER LAKES SHOULD DIMINISH BY NOON ON
SATURDAY... WITH AMPLE SUNSHINE EXPECTED ACROSS THE ENTIRE AREA BY
AFTERNOON. TEMPERATURES WILL BE BELOW NORMAL SATURDAY AND SATURDAY
NIGHT BEFORE A LONG PERIOD OF WARM WEATHER. AFTER A CHILLY START
SUNDAY MORNING EXPECT SUNSHINE AND RAPIDLY WARMING TEMPERATURES
DURING THE AFTERNOON WITH ALL AREAS RECOVERING WELL INTO THE
50S... AND SOME LOWER 60S POSSIBLE OVER THE LAKE PLAIN.
NEXT CHC OF LIGHT PRECIPITATION WILL BE MONDAY AS A CLOSED UPPER
LOW OVER THE SOUTHERN PLAINS LIFTS NORTHEAST TOWARD THE GREAT
LAKES. THE GFS AND ECMWF ARE IN REASONABLY GOOD AGREEMENT WITH
THIS SCENARIO ON MONDAY... ALTHOUGH THE GFS IS SLIGHTLY FARTHER
EAST WITH SOME LIGHT PRECIPITATION. AT THIS POINT A LOW CHC POP
SHOULD COVER THINGS FOR MONDAY WITH SLIGHTLY HIGHER POPS OVER THE
WESTERN PART OF THE COUNTY WARNING AREA.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MEDIUM RANGE MODELS CONTINUE TO INDICATE A SOUTHWEST FLOW REGIME
WILL PERSIST ACROSS THE NORTHEAST WITH WELL ABOVE NORMAL 500MB
HEIGHTS AND MILD CONDITIONS.
TWO SYSTEMS WILL IMPACT THE AREA DURING THIS PERIOD. A SFC LOW WILL
MOVE FROM THE UPPER GREAT LAKES INTO EASTERN CANADA. MODEL
CONSENSUS IS A LITTLE SLOWER THAN YESTERDAY SO WILL INCLUDE CHC
POPS FOR RAIN SHOWERS BOTH MONDAY NIGHT INTO TUESDAY. TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT LOOKS DRY WITH BUILDING H5 HEIGHTS
AND SFC HIGH PRES IN THE VCNTY. A SYSTEM MOVING THROUGH EASTERN
CANADA WILL DRAG A COLD FRONT ACROSS THE AREA THURSDAY INTO
THURSDAY NIGHT. GFS MUCH STRONGER WITH THIS UPPER LEVEL WAVE
THROUGH EASTERN CANADA AND RESULTING SFC LOW COMPARED TO THE
ECMWF. FOLLOWED HPC GUIDANCE WHICH LEANED TOWARD THE GFS.
INCLUDED CHC POPS FOR RAIN SHOWERS THURSDAY/THURSDAY NIGHT,
FOLLOWED BY DRY WEATHER ON FRIDAY.
TEMPS THROUGH THE PERIOD WILL BE WELL ABOVE NORMAL MORE IN LINE
WITH LATE APRIL NORMALS, WITH LOWS GENERALLY IN THE LOWER TO
MIDDLE 40S AND HIGHS UPPER 50S TO MIDDLE 60S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
WITH LOSS OF DIURNAL HEATING...CONVECTIVE SNOW SHOWER COVERAGE HAS
GREATLY DIMINISHED ACROSS NORTHEAST PENNSYLVANIA AND FAR SOUTHERN
NEW YORK. HOWEVER...FARTHER NORTH...LAKE ONTARIO SNOW SHOWERS ARE
AFFECTING KSYR-KRME CORRIDOR. AS THE WIND VEERS 06Z-
12Z...EXPECTING SPREAD OF MVFR CIGS WITH OCCASIONAL MVFR TO IFR
VIS FROM SNOW SHOWERS...AS THE LAKE EFFECT SHIFTS SOUTHWARD TO
INCLUDE MOST OF THE CENTRAL NEW YORK TERMINALS. EVEN KAVP...WHILE
STILL VFR...WILL AT LEAST SEE THE RETURN OF A BRIEF CIG. GUSTS
WILL STILL BE IN 15-22 KT RANGE DURING THE PREDAWN HOURS. SURFACE
HIGH WILL QUICKLY BUILD IN DURING THE DAY SATURDAY...YET MOISTURE
INITIALLY TRAPPED UNDER SUBSIDENCE INVERSION MAY MAKE CIGS A BIT
STUBBORN TO BREAK. HOWEVER...SIGNIFICANT IMPROVEMENT OVERALL 14Z-
18Z. WIND WILL ALSO BECOME VARIABLE THIS AFTERNOON...EVENTUALLY
SETTLING TO LIGHT SOUTHEAST OR SOUTH INTO TONIGHT ON BACK SIDE OF
DEPARTING HIGH PRESSURE. VFR CONDITIONS AND SLACKENING WINDS ARE
FORECAST FOR SATURDAY.
.OUTLOOK...
SUN...VFR.
MON...MAINLY VFR. PSBL MVFR IN LATE DAY SHWRS.
TUE...VFR WITH PSBL MVFR IN -SHRA.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...MSE/RRM
SHORT TERM...MSE
LONG TERM...RRM
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
655 AM EST SAT MAR 10 2012
.SYNOPSIS...
COOL HIGH PRESSURE WILL BUILD INTO THE CAROLINAS THROUGH THE
WEEKEND. A WARMING TREND WILL BEGIN ON SUNDAY... AND CONTINUE
THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 300 AM SATURDAY...
SURFACE HIGH PRESSURE LOCATED OVER EASTERN MICHIGAN IS ARCING AROUND
THE CENTRAL APPALACHIANS AND SOUTH INTO VA/NC. DRIER AIR HAS
FILTERED IN THE THE NORTHERN AND WESTERN PORTIONS OF THE CWA...BUT
DEWPOINT DEPRESSIONS ARE STILL LESS THAN 5 DEGREES ALONG AND EAST OF
I-95. SOME PATCHY FOG AND STRATUS HAVE DEVELOPED FROM FAYETTEVILLE
TO ROANOKE RAPIDS. THE HRRR MODEL APPEARS TO HAVE A GOOD HANDLE ON
THE CURRENT CONDITIONS...SHOWING THE STRATUS AND FOG EXPANDING
EASTWARD BUT ALSO ERODING FROM THE WEST AS DRIER AIR FINALLY PUSHES
INTO THE COASTAL PLAIN BY 12Z. AFTER SUNRISE...CLEAR SKIES WILL
PREVAIL AROUND THE REGION AS HEIGHTS BUILD ALOFT AND THE HIGH
PRESSURE MOVES TOWARD THE MID-ATLANTIC COAST. 1000-850MB
THICKNESSES AROUND 1318M SUPPORT HIGHS A COUPLE DEGREES BELOW MOS
VALUES....WHICH SEEMS REASONABLE GIVEN COOLER NORTHEASTERLY FLOW
TODAY...52 TO 57 NORTHEAST TO SOUTHWEST. OPTIMAL RADIATIONAL
COOLING SHOULD OCCUR TONIGHT...WITH LOWS LIKELY DIPPING INTO THE
UPPER 20S TO AROUND 30S CWA-WIDE.
A WARMING TREND WILL BEGIN SUNDAY AS THE SURFACE HIGH WEAKENS AND
SLIPS SOUTH TO JUST OFF THE NC COAST. SOUTHWESTERLY RETURN FLOW
WILL BEGIN TO DEVELOP...BUT THE HIGH PRESSURE RIDGE WILL STILL BE
DRAPED ACROSS THE STATE...SO SURFACE WINDS WILL REMAIN RELATIVELY
LIGHT AND VARIABLE. 1000-850MB THICKNESSES ARE FORECAST TO RISE 20M
TO AROUND 1340M...WHICH SHOULD RESULT IN HIGHS REACHING TO LOWER
60S. INCREASING HIGH LEVEL MOISTURE AHEAD OF AN UPPER LOW EJECTING
OUT OF THE SOUTHWEST WILL BRING CIRRUS INTO THE WESTERN CWA LATE
SUNDAY...LEADING TO PARTLY O MOSTLY CLOUDY CONDITIONS SUNDAY NIGHT.
THIS COMBINED WITH INCREASING DEWPOINTS IN THE RETURN FLOW WILL KEEP
LOWS SEVERAL DEGREES WARMER...UPPER 30S TO LOWER 40S.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 255 AM SATURDAY...
FOR MONDAY/MONDAY NIGHT: DEEP RIDGING STARTS OUT THE WORK WEEK...
WITH SURFACE HIGH PRESSURE CENTERED JUST EAST OF CAPE HATTERAS AND
AN AMPLIFIED MID LEVEL RIDGE ORIENTED ALONG THE EASTERN SEABOARD.
THE LIGHT LOW LEVEL FLOW FROM THE SOUTHEAST AND SOUTH AND THE
RESULTING UPWARD SURGE IN SURFACE DEW POINTS ALONG WITH THE STABLE
AIR IN THE LOWEST 1-2 KM WILL FOSTER DEVELOPMENT OF LOW STRATUS AND
FOG TO START THE DAY. THIS SHOULD MIX OUT BY MID MORNING DUE TO THE
INCREASING SOUTHERLY FLOW AS THE SURFACE HIGH CENTER SHIFTS FURTHER
OFF THE COAST. BUT ANY MORNING SUNSHINE WILL BE SHORT-LIVED AS HIGH
CLOUDS WILL QUICKLY THICKEN WITH LOWERING BASES MONDAY AS THE CLOSED
LOW NOW OVER SE AZ MOVES NORTHEASTWARD THROUGH WI AND THE U.P. OF MI
INTO ERN ONTARIO. MODELS AGREE QUITE WELL ON RAPIDLY INCREASING
PRECIPITABLE WATER MONDAY AFTERNOON/NIGHT AS THE MOIST AIR CURRENTLY
OVER THE NW GULF AND TX COAST (AS SEEN ON BLENDED TPW IMAGERY) GETS
DRAWN TO THE NORTH THEN NNE INTO NC... WITH PW VALUES OVER NC RISING
FROM NEAR NORMAL TO 200-250 PERCENT OF NORMAL IN JUST 12-18 HRS.
DESPITE THE IMPROVING MOISTURE... FORCING FOR ASCENT REMAINS MEAGER
AS THE TROUGH DAMPENS CONSIDERABLY WHILE TRACKING THROUGH THE OHIO
VALLEY... GENERATING SCANT DPVA. A CLIMATOLOGICALLY WEAK UPPER JET
OF 60-70 KTS OVER THE INTERIOR NORTHEAST AND NEW ENGLAND WILL
PROVIDE LITTLE TO NO UPPER DIVERGENCE IN ITS RIGHT ENTRANCE REGION
OVER NC THROUGH MONDAY NIGHT... AND MOIST ISENTROPIC UPGLIDE IS ALSO
VERY WEAK TO NONEXISTENT AS THE WEAKENING LOW LEVEL JET GETS
DEFLECTED TO OUR NORTH. GIVEN THE HIGH INFLUX OF PW EXPECTED AND
BASED ON MODEL TIMING... BELIEVE WE MAY SEE SOME LIGHT PRECIP ON THE
NORTHERN AND WESTERN PORTIONS OF THE FORECAST AREA LATE MONDAY
NIGHT... BUT THE LACK OF FORCING AND THE SHIFT OF 850 MB WINDS TO
WESTERLY SUPPORTS LITTLE MORE THAN A CHANCE OF VERY LIGHT SHOWERS OR
SPRINKLES. EXPECT SKIES AREAWIDE TO TREND TO MOSTLY CLOUDY MONDAY
AND CLOUDY MONDAY NIGHT. THICKNESSES AROUND 15 METERS ABOVE NORMAL
TEMPERED BY CLOUD COVER SUPPORTS HIGHS IN THE MID 60S TO NEAR 70...
NEAR OR SLIGHTLY BELOW STATISTICAL GUIDANCE. WARM LOWS OF 50-54. -GIH
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 250 AM SATURDAY...
FOR TUESDAY/TUESDAY NIGHT: HIGH PRECIPITABLE WATER AIR WILL CONTINUE
TO ADVECT INTO NC... AND THE LATEST MODEL OUTPUT SUGGESTS THAT
PATCHY SHOWERS WILL LINGER OVER THE AREA ON TUESDAY AS THE SURFACE
FRONT HOLDS JUST TO OUR NW. POLAR STREAM ENERGY DROPS INTO THE
DEAMPLIFYING TROUGH OVER THE ONTARIO/QUEBEC BORDER TUESDAY
MORNING... CAUSING A RESTRENGTHENING AND EVOLUTION INTO A CLOSED MID
LEVEL LOW OVER THE UPPER ST LAWRENCE BY LATE TUESDAY NIGHT... AND
THIS AMPLIFICATION WILL BE AUGMENTED BY A WEAK SOUTHERN STREAM WAVE
WHICH EASES THROUGH NC LATE TUESDAY. WHILE THIS INCREASINGLY
CYCLONIC FLOW OVER THE NORTHEAST AND MIDATLANTIC REGION WILL HELP
PUSH THE SURFACE FRONT TO THE SSE THROUGH NC TUESDAY NIGHT... LOW
LEVEL CONVERGENCE ALONG THE FRONTAL ZONE IS APT TO BE SMALL GIVEN
THE DECREASING SURFACE WINDS. LIFT MECHANISMS ONCE AGAIN APPEAR TO
BE MINOR OR ABSENT... SO WILL KEEP POPS EARLY ON TUESDAY SMALL...
ENDING NW TO SE BY LATE IN THE DAY AS MID LEVEL FLOW BECOMES
NORTHWESTERLY AND THE MID-UPPER LEVELS START TO DRY OUT AND
STABILIZE. THICKNESSES INDICATE HIGHS IN THE LOWER 70S... IN LINE
WITH THE EARLIER FORECAST HIGHS. LOWS ONCE AGAIN 50-54.
FOR WEDNESDAY THROUGH FRIDAY: MID LEVEL RIDGING ONCE AGAIN BUILDS
OVER THE SOUTHEAST STATES AND CAROLINAS FROM THE WEST... AS THE ST
LAWRENCE LOW MOVES OFF THE COAST OF NEW ENGLAND AND CANADIAN
MARITIMES WITH SURFACE HIGH PRESSURE MOVING IN FROM THE WEST. MODELS
ARE IN EXCELLENT AGREEMENT ON THIS PATTERN WITH MUCH ABOVE NORMAL
THICKNESSES AND CONTINUED POSITIVE AO AND NAO... WHICH FAVORS WARM
WEATHER OVER NC. EACH MORNING`S LOW LEVEL THICKNESSES ARE 40-50
METERS ABOVE NORMAL WITH LITTLE DAY-TO-DAY CHANGE IN THE VERTICAL
THERMAL STRUCTURE... WHICH SUPPORTS HIGHS IN THE MID 70S TO NEAR 80
EACH DAY. LOWS IN THE LOWER TO MID 50S. -GIH
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 655 AM SATURDAY...
A FEW PATCHES OF STRATUS DRIFTING SOUTH-SOUTHWEST THROUGH THE
COASTAL PLAIN WILL IMPACT KFAY AND KRWI THROUGH 13Z...BUT SHOULD
THEN MOVE SOUTH AND DISSIPATE BY 13-14Z. STRATUS DRIFTING TOWARD
KFAY MAY CAUSE A BRIEF PERIOD DO IFR CEILINGS DOWN TO 700FT...WHILE
HIGHER BASED STRATUS NEAR KRWI SHOULD DEPART THE TERMINAL AREA BY
13Z. AFTERWARD...VFR CONDITIONS WILL PREVAIL TODAY AS HIGH PRESSURE
BUILDS INTO THE STATE FROM THE NORTH AND NORTHEASTERLY WINDS VARY
FROM 5KT IN THE WEST TO AROUND 10KT IN THE EAST.
OUTLOOK...
HIGH PRESSURE WILL SLIDE SOUTHEAST OF THE CAROLINA COAST
SUNDAY...LEADING TO RETURN FLOW AND A CHANCE OF STRATUS AND MVFR TO
IFR CEILINGS THROUGH EACH MORNING THIS WEEK. IN ADDITION...A FEW
SHOWERS WILL BE POSSIBLE TUESDAY AFTERNOON AS A WEAK FRONT DROPS
SOUTH INTO NC.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...SMITH
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
302 AM EST SAT MAR 10 2012
.SYNOPSIS...
COOL HIGH PRESSURE WILL BUILD INTO THE CAROLINAS THROUGH THE
WEEKEND. A WARMING TREND WILL BEGIN ON SUNDAY... AND CONTINUE
THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 300 AM SATURDAY...
SURFACE HIGH PRESSURE LOCATED OVER EASTERN MICHIGAN IS ARCING AROUND
THE CENTRAL APPALACHIANS AND SOUTH INTO VA/NC. DRIER AIR HAS
FILTERED IN THE THE NORTHERN AND WESTERN PORTIONS OF THE CWA...BUT
DEWPOINT DEPRESSIONS ARE STILL LESS THAN 5 DEGREES ALONG AND EAST OF
I-95. SOME PATCHY FOG AND STRATUS HAVE DEVELOPED FROM FAYETTEVILLE
TO ROANOKE RAPIDS. THE HRRR MODEL APPEARS TO HAVE A GOOD HANDLE ON
THE CURRENT CONDITIONS...SHOWING THE STRATUS AND FOG EXPANDING
EASTWARD BUT ALSO ERODING FROM THE WEST AS DRIER AIR FINALLY PUSHES
INTO THE COASTAL PLAIN BY 12Z. AFTER SUNRISE...CLEAR SKIES WILL
PREVAIL AROUND THE REGION AS HEIGHTS BUILD ALOFT AND THE HIGH
PRESSURE MOVES TOWARD THE MID-ATLANTIC COAST. 1000-850MB
THICKNESSES AROUND 1318M SUPPORT HIGHS A COUPLE DEGREES BELOW MOS
VALUES....WHICH SEEMS REASONABLE GIVEN COOLER NORTHEASTERLY FLOW
TODAY...52 TO 57 NORTHEAST TO SOUTHWEST. OPTIMAL RADIATIONAL
COOLING SHOULD OCCUR TONIGHT...WITH LOWS LIKELY DIPPING INTO THE
UPPER 20S TO AROUND 30S CWA-WIDE.
A WARMING TREND WILL BEGIN SUNDAY AS THE SURFACE HIGH WEAKENS AND
SLIPS SOUTH TO JUST OFF THE NC COAST. SOUTHWESTERLY RETURN FLOW
WILL BEGIN TO DEVELOP...BUT THE HIGH PRESSURE RIDGE WILL STILL BE
DRAPED ACROSS THE STATE...SO SURFACE WINDS WILL REMAIN RELATIVELY
LIGHT AND VARIABLE. 1000-850MB THICKNESSES ARE FORECAST TO RISE 20M
TO AROUND 1340M...WHICH SHOULD RESULT IN HIGHS REACHING TO LOWER
60S. INCREASING HIGH LEVEL MOISTURE AHEAD OF AN UPPER LOW EJECTING
OUT OF THE SOUTHWEST WILL BRING CIRRUS INTO THE WESTERN CWA LATE
SUNDAY...LEADING TO PARTLY O MOSTLY CLOUDY CONDITIONS SUNDAY NIGHT.
THIS COMBINED WITH INCREASING DEWPOINTS IN THE RETURN FLOW WILL KEEP
LOWS SEVERAL DEGREES WARMER...UPPER 30S TO LOWER 40S.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 255 AM SATURDAY...
FOR MONDAY/MONDAY NIGHT: DEEP RIDGING STARTS OUT THE WORK WEEK...
WITH SURFACE HIGH PRESSURE CENTERED JUST EAST OF CAPE HATTERAS AND
AN AMPLIFIED MID LEVEL RIDGE ORIENTED ALONG THE EASTERN SEABOARD.
THE LIGHT LOW LEVEL FLOW FROM THE SOUTHEAST AND SOUTH AND THE
RESULTING UPWARD SURGE IN SURFACE DEW POINTS ALONG WITH THE STABLE
AIR IN THE LOWEST 1-2 KM WILL FOSTER DEVELOPMENT OF LOW STRATUS AND
FOG TO START THE DAY. THIS SHOULD MIX OUT BY MID MORNING DUE TO THE
INCREASING SOUTHERLY FLOW AS THE SURFACE HIGH CENTER SHIFTS FURTHER
OFF THE COAST. BUT ANY MORNING SUNSHINE WILL BE SHORT-LIVED AS HIGH
CLOUDS WILL QUICKLY THICKEN WITH LOWERING BASES MONDAY AS THE CLOSED
LOW NOW OVER SE AZ MOVES NORTHEASTWARD THROUGH WI AND THE U.P. OF MI
INTO ERN ONTARIO. MODELS AGREE QUITE WELL ON RAPIDLY INCREASING
PRECIPITABLE WATER MONDAY AFTERNOON/NIGHT AS THE MOIST AIR CURRENTLY
OVER THE NW GULF AND TX COAST (AS SEEN ON BLENDED TPW IMAGERY) GETS
DRAWN TO THE NORTH THEN NNE INTO NC... WITH PW VALUES OVER NC RISING
FROM NEAR NORMAL TO 200-250 PERCENT OF NORMAL IN JUST 12-18 HRS.
DESPITE THE IMPROVING MOISTURE... FORCING FOR ASCENT REMAINS MEAGER
AS THE TROUGH DAMPENS CONSIDERABLY WHILE TRACKING THROUGH THE OHIO
VALLEY... GENERATING SCANT DPVA. A CLIMATOLOGICALLY WEAK UPPER JET
OF 60-70 KTS OVER THE INTERIOR NORTHEAST AND NEW ENGLAND WILL
PROVIDE LITTLE TO NO UPPER DIVERGENCE IN ITS RIGHT ENTRANCE REGION
OVER NC THROUGH MONDAY NIGHT... AND MOIST ISENTROPIC UPGLIDE IS ALSO
VERY WEAK TO NONEXISTENT AS THE WEAKENING LOW LEVEL JET GETS
DEFLECTED TO OUR NORTH. GIVEN THE HIGH INFLUX OF PW EXPECTED AND
BASED ON MODEL TIMING... BELIEVE WE MAY SEE SOME LIGHT PRECIP ON THE
NORTHERN AND WESTERN PORTIONS OF THE FORECAST AREA LATE MONDAY
NIGHT... BUT THE LACK OF FORCING AND THE SHIFT OF 850 MB WINDS TO
WESTERLY SUPPORTS LITTLE MORE THAN A CHANCE OF VERY LIGHT SHOWERS OR
SPRINKLES. EXPECT SKIES AREAWIDE TO TREND TO MOSTLY CLOUDY MONDAY
AND CLOUDY MONDAY NIGHT. THICKNESSES AROUND 15 METERS ABOVE NORMAL
TEMPERED BY CLOUD COVER SUPPORTS HIGHS IN THE MID 60S TO NEAR 70...
NEAR OR SLIGHTLY BELOW STATISTICAL GUIDANCE. WARM LOWS OF 50-54. -GIH
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 250 AM SATURDAY...
FOR TUESDAY/TUESDAY NIGHT: HIGH PRECIPITABLE WATER AIR WILL CONTINUE
TO ADVECT INTO NC... AND THE LATEST MODEL OUTPUT SUGGESTS THAT
PATCHY SHOWERS WILL LINGER OVER THE AREA ON TUESDAY AS THE SURFACE
FRONT HOLDS JUST TO OUR NW. POLAR STREAM ENERGY DROPS INTO THE
DEAMPLIFYING TROUGH OVER THE ONTARIO/QUEBEC BORDER TUESDAY
MORNING... CAUSING A RESTRENGTHENING AND EVOLUTION INTO A CLOSED MID
LEVEL LOW OVER THE UPPER ST LAWRENCE BY LATE TUESDAY NIGHT... AND
THIS AMPLIFICATION WILL BE AUGMENTED BY A WEAK SOUTHERN STREAM WAVE
WHICH EASES THROUGH NC LATE TUESDAY. WHILE THIS INCREASINGLY
CYCLONIC FLOW OVER THE NORTHEAST AND MIDATLANTIC REGION WILL HELP
PUSH THE SURFACE FRONT TO THE SSE THROUGH NC TUESDAY NIGHT... LOW
LEVEL CONVERGENCE ALONG THE FRONTAL ZONE IS APT TO BE SMALL GIVEN
THE DECREASING SURFACE WINDS. LIFT MECHANISMS ONCE AGAIN APPEAR TO
BE MINOR OR ABSENT... SO WILL KEEP POPS EARLY ON TUESDAY SMALL...
ENDING NW TO SE BY LATE IN THE DAY AS MID LEVEL FLOW BECOMES
NORTHWESTERLY AND THE MID-UPPER LEVELS START TO DRY OUT AND
STABILIZE. THICKNESSES INDICATE HIGHS IN THE LOWER 70S... IN LINE
WITH THE EARLIER FORECAST HIGHS. LOWS ONCE AGAIN 50-54.
FOR WEDNESDAY THROUGH FRIDAY: MID LEVEL RIDGING ONCE AGAIN BUILDS
OVER THE SOUTHEAST STATES AND CAROLINAS FROM THE WEST... AS THE ST
LAWRENCE LOW MOVES OFF THE COAST OF NEW ENGLAND AND CANADIAN
MARITIMES WITH SURFACE HIGH PRESSURE MOVING IN FROM THE WEST. MODELS
ARE IN EXCELLENT AGREEMENT ON THIS PATTERN WITH MUCH ABOVE NORMAL
THICKNESSES AND CONTINUED POSITIVE AO AND NAO... WHICH FAVORS WARM
WEATHER OVER NC. EACH MORNING`S LOW LEVEL THICKNESSES ARE 40-50
METERS ABOVE NORMAL WITH LITTLE DAY-TO-DAY CHANGE IN THE VERTICAL
THERMAL STRUCTURE... WHICH SUPPORTS HIGHS IN THE MID 70S TO NEAR 80
EACH DAY. LOWS IN THE LOWER TO MID 50S. -GIH
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1240 AM SATURDAY...
SITES FROM KCTZ TO KIXA..MAINLY ALONG AND EAST OF I-95.... ARE
REPORTING MVFR/IFR VSBYS WHERE DEWPOINTS HAVE YET TO BEGIN TO CRASH.
NEAR TERM MODEL GUIDANCE...NAMELY THE HRRR MODEL...SHOWS THIS AREA
EXPANDING THROUGH 09Z...THEN SHIFTING EASTWARD AS DRIER AIR AIR
ADVECTS IN FROM THE NORTHWEST. KRWI AND KFAY WILL LIKELY BE ON THE
WESTERN EDGE OF THE LOWER VSBYS FOR A FEW HOURS...THOUGH CONFIDENCE
IS HIGHER FOR KRWI WHERE VSBYS HAVE ALREADY DROPPED TO 3/4MI. VSBYS
MAY BOUNCE UP AND DOWN THROUGH 09Z...WITH IMPROVEMENT AFTERWARD.
CLEAR SKIES WITH NORTHEASTERLY WINDS AND A FEW GUSTS TO NEAR 20KT IN
THE EAST ARE EXPECTED DURING THE DAY TODAY...WITH VFR CONDITIONS
PREVAILING THROUGH THE END OF THE TAF PERIOD. -SMITH
THE AREA OF HIGH PRESSURE WILL RESULT IN VFR CONDITIONS ACROSS THE
REGION THROUGH AT LEAST SUNDAY EVENING. AS THE HIGH SHIFTS OFFSHORE
SUNDAY NIGHT INTO EARLY MONDAY...THE RETURN FLOW ON THE BACKSIDE OF
THE HIGH WILL BRING AN INCREASE IN LOW LEVEL MOISTURE ALONG WITH THE
POSSIBILITY OF PATCHY MVFR CEILINGS. THE THREAT FOR MORNING STRATUS
MAY BE HIGHER TUESDAY AND WEDNESDAY MORNINGS. -KRR
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...SMITH
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...SMITH/KRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 AM EST SAT MAR 10 2012
.SYNOPSIS...
COOL HIGH PRESSURE WILL BUILD INTO THE CAROLINAS THROUGH THE
WEEKEND. A WARMING TREND WILL BEGIN ON SUNDAY... AND CONTINUE
THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 300 AM SATURDAY...
SURFACE HIGH PRESSURE LOCATED OVER EASTERN MICHIGAN IS ARCING AROUND
THE CENTRAL APPALACHIANS AND SOUTH INTO VA/NC. DRIER AIR HAS
FILTERED IN THE THE NORTHERN AND WESTERN PORTIONS OF THE CWA...BUT
DEWPOINT DEPRESSIONS ARE STILL LESS THAN 5 DEGREES ALONG AND EAST OF
I-95. SOME PATCHY FOG AND STRATUS HAVE DEVELOPED FROM FAYETTEVILLE
TO ROANOKE RAPIDS. THE HRRR MODEL APPEARS TO HAVE A GOOD HANDLE ON
THE CURRENT CONDITIONS...SHOWING THE STRATUS AND FOG EXPANDING
EASTWARD BUT ALSO ERODING FROM THE WEST AS DRIER AIR FINALLY PUSHES
INTO THE COASTAL PLAIN BY 12Z. AFTER SUNRISE...CLEAR SKIES WILL
PREVAIL AROUND THE REGION AS HEIGHTS BUILD ALOFT AND THE HIGH
PRESSURE MOVES TOWARD THE MID-ATLANTIC COAST. 1000-850MB
THICKNESSES AROUND 1318M SUPPORT HIGHS A COUPLE DEGREES BELOW MOS
VALUES....WHICH SEEMS REASONABLE GIVEN COOLER NORTHEASTERLY FLOW
TODAY...52 TO 57 NORTHEAST TO SOUTHWEST. OPTIMAL RADIATIONAL
COOLING SHOULD OCCUR TONIGHT...WITH LOWS LIKELY DIPPING INTO THE
UPPER 20S TO AROUND 30S CWA-WIDE.
A WARMING TREND WILL BEGIN SUNDAY AS THE SURFACE HIGH WEAKENS AND
SLIPS SOUTH TO JUST OFF THE NC COAST. SOUTHWESTERLY RETURN FLOW
WILL BEGIN TO DEVELOP...BUT THE HIGH PRESSURE RIDGE WILL STILL BE
DRAPED ACROSS THE STATE...SO SURFACE WINDS WILL REMAIN RELATIVELY
LIGHT AND VARIABLE. 1000-850MB THICKNESSES ARE FORECAST TO RISE 20M
TO AROUND 1340M...WHICH SHOULD RESULT IN HIGHS REACHING TO LOWER
60S. INCREASING HIGH LEVEL MOISTURE AHEAD OF AN UPPER LOW EJECTING
OUT OF THE SOUTHWEST WILL BRING CIRRUS INTO THE WESTERN CWA LATE
SUNDAY...LEADING TO PARTLY O MOSTLY CLOUDY CONDITIONS SUNDAY NIGHT.
THIS COMBINED WITH INCREASING DEWPOINTS IN THE RETURN FLOW WILL KEEP
LOWS SEVERAL DEGREES WARMER...UPPER 30S TO LOWER 40S.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 200 PM FRIDAY...
INITIAL COOL WEDGED AIRMASS WILL BE DISPLACED AS THE SURFACE HIGH
PRESSURE SHIFTS OFFSHORE AND AN UPPER RIDGE AMPLIFIES OVER THE EAST
COAST. THUS CAN EXPECT DEEPENING SOUTH TO SOUTHWEST FLOW AND
INITIATION OF AN ACCOMPANYING WARMING TREND SUNDAY INTO EARLY NEXT
WEEK. HIGHS SUNDAY WILL BE NEAR TO SLIGHTLY ABOVE NORMAL...MOSTLY IN
THE LOW 60S. GOOD RADIATIONAL CONDITIONS WILL ALLOW TEMPS TO SLIP
BACK TO AROUND 40 SUNDAY NIGHT...WITH ADDITIONAL WARM ADVECTION
PUSHING HIGHS INTO THE UPPER 60S MONDAY.
AN UPPER SYSTEM IN THE MIDWEST WILL BE LIFTING NORTHEAST INTO THE
GREAT LAKES REGION MONDAY. THE ASSOCIATED SURFACE FRONT AND DEEPER
MOISTURE WILL STRONGLY SHEARED AND SLOW TO MOVE EAST...HENCE EXPECT
INCREASING MAINLY HIGH CLOUDINESS MONDAY...WITH SHOWERS DELAYED INTO
MONDAY NIGHT.
FRONT EDGES EAST AND ACROSS THE AREA ON TUESDAY WITH WEAK LOW LEVEL
FORCING. WILL LEAVE SLIGHT CHANCES IN PLACE FOR THE TUESDAY...
ALTHOUGH A WEAK SOUTHERN STREAM VORT MAX IS SUGGESTED BY BOTH GFS
AND ECMWF. THIS VORT MAX WOULD BE MOVING ALONG WITH THE FRONT
CONCURRENT WITH MAX HEATING AND SLIGHT CHANCE POPS MIGHT NEED TO BE
ADJUSTED UP IF THIS FEATURE SHOWS CONSENSUS AND PERSISTENCE IN LATER
MODEL RUNS. TUESDAYS POTENTIAL HIGHS PER LOW LEVEL THICKNESS WILL BE
TEMPERED BY THE CLOUD COVER AND POTENTIAL PRECIP...LOWER 70S LOOK
GOOD. FRONT MOVES OFF...LEAVING A WARM AIRMASS IN PLACE WITH
RESIDUAL CLOUD COVERAGE...TUE NIGHT MINS WILL BE QUITE MILD...IN THE
LOWER 50S.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 200 PM FRIDAY...
CYCLE BEGINS ANEW...WITH A SOUTHERN STREAM SHORT WAVE RIDGE BUILDING
BRIEFLY UP THE EAST COAST. WARM AIRMASS IN PLACE INITIALLY WILL BE
REINFORCED AND HIGHS WED WILL REACH THE MID 70S...PERHAPS UPPER 70S
GIVEN A NUDGE FROM INSOLATION.
MOISTURE WILL BE ON THE INCREASE ACROSS THE WESTERN GULF STATES AND
ADVECT UP THE RIDGE EAST AND NORTHEAST INTO THE AREA IN THE THURSDAY
AND FRIDAY TIME FRAME. INITIALLY WILL HAVE ONLY SLIGHT CHANCES IN
THE WEST ON THURSDAY GIVEN THE BLOCKING RIDGE...WITH SMALL CHANCES
EVERYWHERE FRIDAY AS THE RIDGE FLATTENS AND OUR NEXT COLD FRONT IS
FREED TO MAKE ITS WAY SOUTHEAST INTO THE AREA FRIDAY.
HIGHS THU AND FRI WILL BE MUCH ABOVE NORMAL...IN THE MID TO UPPER
70S...WITH POTENTIAL FOR LOWER 80S GIVEN ANY SUN...ESPECIALLY
THURSDAY. OVERNIGHT MINS SIMILARLY VERY MILD...LOW TO MID 50S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1240 AM SATURDAY...
SITES FROM KCTZ TO KIXA..MAINLY ALONG AND EAST OF I-95.... ARE
REPORTING MVFR/IFR VSBYS WHERE DEWPOINTS HAVE YET TO BEGIN TO CRASH.
NEAR TERM MODEL GUIDANCE...NAMELY THE HRRR MODEL...SHOWS THIS AREA
EXPANDING THROUGH 09Z...THEN SHIFTING EASTWARD AS DRIER AIR AIR
ADVECTS IN FROM THE NORTHWEST. KRWI AND KFAY WILL LIKELY BE ON THE
WESTERN EDGE OF THE LOWER VSBYS FOR A FEW HOURS...THOUGH CONFIDENCE
IS HIGHER FOR KRWI WHERE VSBYS HAVE ALREADY DROPPED TO 3/4MI. VSBYS
MAY BOUNCE UP AND DOWN THROUGH 09Z...WITH IMPROVEMENT AFTERWARD.
CLEAR SKIES WITH NORTHEASTERLY WINDS AND A FEW GUSTS TO NEAR 20KT IN
THE EAST ARE EXPECTED DURING THE DAY TODAY...WITH VFR CONDITIONS
PREVAILING THROUGH THE END OF THE TAF PERIOD. -SMITH
THE AREA OF HIGH PRESSURE WILL RESULT IN VFR CONDITIONS ACROSS THE
REGION THROUGH AT LEAST SUNDAY EVENING. AS THE HIGH SHIFTS OFFSHORE
SUNDAY NIGHT INTO EARLY MONDAY...THE RETURN FLOW ON THE BACKSIDE OF
THE HIGH WILL BRING AN INCREASE IN LOW LEVEL MOISTURE ALONG WITH THE
POSSIBILITY OF PATCHY MVFR CEILINGS. THE THREAT FOR MORNING STRATUS
MAY BE HIGHER TUESDAY AND WEDNESDAY MORNINGS. -KRR
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...SMITH
SHORT TERM...MLM
LONG TERM...MLM
AVIATION...SMITH/KRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1240 AM EST SAT MAR 10 2012
.SYNOPSIS...
COOL HIGH PRESSURE WILL BUILD INTO THE CAROLINAS THROUGH THE
WEEKEND. A WARMING TREND WILL BEGIN ON SUNDAY... AND CONTINUE
THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
AS OF 220 PM FRIDAY...
TONIGHT...PASSAGE OF H7 TROUGH THIS EVENING HAS FINALLY
ALLOWED CLOUDS TO CLEAR OUT...WITH CLEAR SKIES EXPECTED FOR THE
REMAINDER OF THE NIGHT. 1034MB SURFACE HIGH CENTERED OVER LAKE
MICHIGAN WILL BUILD SOUTHEAST INTO THE AREA THROUGH SATURDAY. LOWS
TONIGHT WILL BE DRIVEN BY CAA WITH STEADY NORTHERLY BREEZE OF 7
TO 10 KTS. LOW-LEVEL THICKNESSES ARE FORECAST TO BOTTOM OUT AOA 1300
METERS BY DAYBREAK. HOWEVER A WELL MIXED BOUNDARY LAYER WILL
PREVENT SFC TEMPERATURES FROM REALIZING FULL COOLING POTENTIAL.
LOWS IN THE LOWER TO MID 30S.
SATURDAY...SURFACE HIGH (1035+ MB) OVER THE OH VALLEY WILL EXTEND
INTO THE CAROLINAS. CIRCULATION AROUND THIS WEATHER FEATURE WILL
RESULT IN A CHILLY NE SURFACE FLOW INITIALLY WITH INFREQUENT GUSTS
15-20 MPH IN THE MORNING. THIS SURFACE FLOW WILL ABATE IN THE
AFTERNOON AS THE SURFACE RIDGE BECOMES ESTABLISHED OVER THE FORECAST
AREA. LOW LEVEL THICKNESSES AVERAGE ABOUT 20M BELOW NORMAL. THIS
YIELDS MAX TEMPS MAINLY IN THE LOW-MID 50S WITH THE COOLEST TEMPS IN
THE NE COUNTIES WHERE THE 850MB THERMAL TROUGH LINGERS LONGER. MAY
SEE A FEW UPPER 50S IN THE FAR SOUTH.
SATURDAY NIGHT...SURFACE HIGH AND ATTENDANT 850MB ANTI-CYCLONE
PROJECTED TO LIE OVERHEAD SATURDAY NIGHT. MID LEVEL RIDGE AXIS TO
OUR WEST SHOULD HOLD OFF ANY HIGH LEVEL CIRRUS. WITH CLEAR...COOL
AND DRY AIR MASS IN PLACE...SURFACE AIR MASS SHOULD COOL VERY
EFFICIENTLY. THIS SUPPORTS MIN TEMPS A COUPLE OF DEGREES COOLER THAN
MOS GUIDANCE. POTENTIAL FOR NORMALLY COLDER LOCALES TO DIP INTO
THE MID 20S WITH UPPER 20S-LOWER 30S EXPECTED ELSEWHERE.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 200 PM FRIDAY...
INITIAL COOL WEDGED AIRMASS WILL BE DISPLACED AS THE SURFACE HIGH
PRESSURE SHIFTS OFFSHORE AND AN UPPER RIDGE AMPLIFIES OVER THE EAST
COAST. THUS CAN EXPECT DEEPENING SOUTH TO SOUTHWEST FLOW AND
INITIATION OF AN ACCOMPANYING WARMING TREND SUNDAY INTO EARLY NEXT
WEEK. HIGHS SUNDAY WILL BE NEAR TO SLIGHTLY ABOVE NORMAL...MOSTLY IN
THE LOW 60S. GOOD RADIATIONAL CONDITIONS WILL ALLOW TEMPS TO SLIP
BACK TO AROUND 40 SUNDAY NIGHT...WITH ADDITIONAL WARM ADVECTION
PUSHING HIGHS INTO THE UPPER 60S MONDAY.
AN UPPER SYSTEM IN THE MIDWEST WILL BE LIFTING NORTHEAST INTO THE
GREAT LAKES REGION MONDAY. THE ASSOCIATED SURFACE FRONT AND DEEPER
MOISTURE WILL STRONGLY SHEARED AND SLOW TO MOVE EAST...HENCE EXPECT
INCREASING MAINLY HIGH CLOUDINESS MONDAY...WITH SHOWERS DELAYED INTO
MONDAY NIGHT.
FRONT EDGES EAST AND ACROSS THE AREA ON TUESDAY WITH WEAK LOW LEVEL
FORCING. WILL LEAVE SLIGHT CHANCES IN PLACE FOR THE TUESDAY...
ALTHOUGH A WEAK SOUTHERN STREAM VORT MAX IS SUGGESTED BY BOTH GFS
AND ECMWF. THIS VORT MAX WOULD BE MOVING ALONG WITH THE FRONT
CONCURRENT WITH MAX HEATING AND SLIGHT CHANCE POPS MIGHT NEED TO BE
ADJUSTED UP IF THIS FEATURE SHOWS CONSENSUS AND PERSISTENCE IN LATER
MODEL RUNS. TUESDAYS POTENTIAL HIGHS PER LOW LEVEL THICKNESS WILL BE
TEMPERED BY THE CLOUD COVER AND POTENTIAL PRECIP...LOWER 70S LOOK
GOOD. FRONT MOVES OFF...LEAVING A WARM AIRMASS IN PLACE WITH
RESIDUAL CLOUD COVERAGE...TUE NIGHT MINS WILL BE QUITE MILD...IN THE
LOWER 50S.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 200 PM FRIDAY...
CYCLE BEGINS ANEW...WITH A SOUTHERN STREAM SHORT WAVE RIDGE BUILDING
BRIEFLY UP THE EAST COAST. WARM AIRMASS IN PLACE INITIALLY WILL BE
REINFORCED AND HIGHS WED WILL REACH THE MID 70S...PERHAPS UPPER 70S
GIVEN A NUDGE FROM INSOLATION.
MOISTURE WILL BE ON THE INCREASE ACROSS THE WESTERN GULF STATES AND
ADVECT UP THE RIDGE EAST AND NORTHEAST INTO THE AREA IN THE THURSDAY
AND FRIDAY TIME FRAME. INITIALLY WILL HAVE ONLY SLIGHT CHANCES IN
THE WEST ON THURSDAY GIVEN THE BLOCKING RIDGE...WITH SMALL CHANCES
EVERYWHERE FRIDAY AS THE RIDGE FLATTENS AND OUR NEXT COLD FRONT IS
FREED TO MAKE ITS WAY SOUTHEAST INTO THE AREA FRIDAY.
HIGHS THU AND FRI WILL BE MUCH ABOVE NORMAL...IN THE MID TO UPPER
70S...WITH POTENTIAL FOR LOWER 80S GIVEN ANY SUN...ESPECIALLY
THURSDAY. OVERNIGHT MINS SIMILARLY VERY MILD...LOW TO MID 50S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1240 AM SATURDAY...
SITES FROM KCTZ TO KIXA..MAINLY ALONG AND EAST OF I-95.... ARE
REPORTING MVFR/IFR VSBYS WHERE DEWPOINTS HAVE YET TO BEGIN TO CRASH.
NEAR TERM MODEL GUIDANCE...NAMELY THE HRRR MODEL...SHOWS THIS AREA
EXPANDING THROUGH 09Z...THEN SHIFTING EASTWARD AS DRIER AIR AIR
ADVECTS IN FROM THE NORTHWEST. KRWI AND KFAY WILL LIKELY BE ON THE
WESTERN EDGE OF THE LOWER VSBYS FOR A FEW HOURS...THOUGH CONFIDENCE
IS HIGHER FOR KRWI WHERE VSBYS HAVE ALREADY DROPPED TO 3/4MI. VSBYS
MAY BOUNCE UP AND DOWN THROUGH 09Z...WITH IMPROVEMENT AFTERWARD.
CLEAR SKIES WITH NORTHEASTERLY WINDS AND A FEW GUSTS TO NEAR 20KT IN
THE EAST ARE EXPECTED DURING THE DAY TODAY...WITH VFR CONDITIONS
PREVAILING THROUGH THE END OF THE TAF PERIOD. -SMITH
THE AREA OF HIGH PRESSURE WILL RESULT IN VFR CONDITIONS ACROSS THE
REGION THROUGH AT LEAST SUNDAY EVENING. AS THE HIGH SHIFTS OFFSHORE
SUNDAY NIGHT INTO EARLY MONDAY...THE RETURN FLOW ON THE BACKSIDE OF
THE HIGH WILL BRING AN INCREASE IN LOW LEVEL MOISTURE ALONG WITH THE
POSSIBILITY OF PATCHY MVFR CEILINGS. THE THREAT FOR MORNING STRATUS
MAY BE HIGHER TUESDAY AND WEDNESDAY MORNINGS. -KRR
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...CBL/WSS
SHORT TERM...MLM
LONG TERM...MLM
AVIATION...SMITH/KRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
318 PM CST SAT MAR 10 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY
PRIMARY FORECAST CHALLENGE WILL BE TEMPERATURES AND FOG POTENTIAL.
MODELS ARE IN GOOD AGREEMENT...BUT ALL HAVE PERFORMED POORLY WITH
TEMPERATURES. WILL USE A BLENDED SOLUTION WITH NO REAL MODEL
PREFERENCE FOR TEMPERATURE GUIDANCE...NOTING THAT EVEN THE RUC IS
STRUGGLING.
VERY WARM TEMPERATURES TODAY HAVE RESULTED IN SIGNIFICANT SNOW
MELT AND INCREASING LOW-LEVEL MOISTURE WITH DEW POINTS IN THE
UPPER 20S TO MID 30S. HIGH MOISTURE...COMBINED WITH CLEAR SKIES
AND LIGHT WIND OVERNIGHT WILL RESULT IN FOG DEVELOPMENT. AREAL
COVERAGE AND TIMING UNCERTAINTIES EXIST...BUT WOULD NOT BE
SURPRISED TO SEE AREAS OF DENSE FOG WITH VISIBILITY BELOW 1 SM.
FOR NOW...ADDED AREAS OF FOG FOR THE ENTIRE FORECAST AREA FROM 03
UTC TONIGHT UNTIL 15 UTC TOMORROW MORNING. EVENING SHIFT WILL NEED
TO MONITOR OBSERVATIONS FOR POSSIBLE ADVISORY CONDITIONS.
TEMPERATURES TONIGHT NOT EXPECTED TO COOL MUCH BELOW CURRENT DEW
POINT VALUES...SO WILL GO WITH LOWS FROM THE UPPER 20S TO THE
LOWER 30S.
TEMPERATURES SUNDAY WILL BE TRICKY WITH SEVERAL COMPETING FACTORS.
EARLY MORNING FOG COULD DELAY TEMPERATURE RISE...BUT INCREASING
SOUTH-SOUTHEAST WIND AND MARCH SUN ANGLE SHOULD HELP LIFT/BURN OFF
FOG RATHER RAPIDLY. THE REST OF THE DAY WILL SEE SOME INCREASING
CIRRUS...BUT REMAIN MOSTLY SUNNY. SURFACE INVERSION SHOULD NOT BE
NEARLY AS STRONG AS TODAY WITH BOUNDARY LAYER WINDS AROUND 20 KTS
AND TEMPERATURES ALOFT FROM +10 TO +12 C. TEMPERATURES SHOULD BE
CLOSE TO THOSE OBSERVED TODAY WITH HIGHS IN THE MID 40S TO MID
50S. HIGHER TEMPERATURES ARE POSSIBLE...BUT WILL BE CAUTIOUS/
CONSERVATIVE WITH DEGREE OF WARMING AT THIS TIME GIVEN SOUTHERLY
WIND DIRECTION AND POSSIBLE FOG IMPACTS.
AZ/NM CUT-OFF LOW EJECTS NORTHEASTWARD TOWARD THE MN ARROWHEAD
SUNDAY NIGHT AND MONDAY...BRINGING THE NEXT CHANCE OF PRECIPITATION.
TEMPERATURES ARE WARM ENOUGH FOR ALL RAIN AND FAVORED AREA IS
STILL ALONG AND EAST OF THE VALLEY GIVEN WARM AIR ADVECTION/
ISENTROPIC LIFT...FOLLOWED BY WRAP AROUND MOISTURE. RAINFALL
AMOUNTS THROUGH MONDAY UP TO 0.3 INCH ARE POSSIBLE. WILL HAVE TO
WATCH FOR POTENTIAL IMPACTS ON AREA RIVERS AND STREAMS GIVEN
CONCURRENT SNOW MELT. HIGH TEMPERATURES MONDAY WILL STILL BE WELL
ABOVE NORMAL FROM THE UPPER 40S TO UPPER 50S...BUT SLIGHTLY COOLER
ACROSS MN WHERE CLOUDS AND RAIN SHOULD LIMIT RISE.
A FAST MOVING COLD FRONT DROPS SOUTH ACROSS THE FORECAST AREA MONDAY
AFTERNOON AND EVENING...BUT ONLY IMPACTS SHOULD BE SLIGHTLY COOLER
LOWS TUESDAY MORNING FROM THE MID 20S TO LOWER 30S AND BREEZY
NORTHWEST WIND. COOLER AIR IS QUICKLY REPLACED BY THERMAL RIDGE ALOFT
TUESDAY AFTERNOON...ALLOWING HIGH TEMPERATURES TO CLIMB BACK INTO
THE 50S AND LOWER 60S.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
MEDIUM RANGE MODELS ARE IN FAIRLY GOOD AGREEMENT ON SOUTHWESTERLY
FLOW ALOFT WITH A SHORTWAVE TROUGH EJECTING INTO MANITOBA TUESDAY
NIGHT. THIS WILL HELP PUSH A COLD FRONT DOWN INTO THE CWA LATE
TUESDAY NIGHT INTO WEDNESDAY...WITH SFC HIGH PRESSURE BUILDING IN
BEHIND IT. EVEN WITH THE COLD FRONT TEMPS WILL STILL BE WELL ABOVE
AVERAGE. SOUTHWESTERLY FLOW ALOFT WILL CONTINUE THROUGH THE REST OF
THE PERIOD...WITH SOUTH TO SOUTHWESTERLY WINDS AT THE SFC AS LOW
PRESSURE SETS UP TO OUR NORTHWEST. 850MB TEMPS GET WELL INTO THE
TEENS C...AND WITH WARM TEMPS FOR MUCH OF THE WEEK BEFORE...THERE
WILL NOT BE MUCH SNOW LEFT TO KEEP TEMPS DOWN. WILL CONTINUE TO
KEEP HIGHS IN THE 50S AND 60S FOR THURSDAY THROUGH SATURDAY...WITH
OVERNIGHT LOWS MILD IN THE UPPER 30S INTO THE 40S. WITH TEMPS
STAYING ABOVE THE FREEZING MARK...SNOW MELT AND RUN OFF WILL PICK UP
SPEED AND WILL HAVE TO WATCH RIVER LEVELS CLOSELY.
BY SATURDAY...THERE START TO BE SOME DIFFERENCES IN THE OVERALL
PATTERN WITH THE GFS EJECTING A SHORTWAVE TROUGH FROM THE NORTHERN
ROCKIES INTO SOUTHERN CANADA WHILE THE ECMWF IS MUCH MORE AMPLIFIED
AND SHOWS NO SHORTWAVE. THE GFS HAS PLENTY OF MOISTURE STREAMING UP
FROM THE GULF AND A FEW OF THE NAEFS ENSEMBLE MEMBERS HAVE PRECIP
FOR SATURDAY...SO KEPT THE LOW POPS THAT ALLBLEND GAVE US.
SHOWALTERS ARE NEGATIVE...BUT WILL HOLD OFF ON ANY THUNDER MENTION
FOR NOW AND JUST INCLUDE RAIN SHOWERS.
&&
.AVIATION...
WITH WARM TEMPERATURES THIS AFTERNOON MELTING SNOW...DEWPOINTS HAVE
RISEN INTO THE LOWER 30S ACROSS MUCH OF THE AREA. WITH LIGHT
WINDS...INCREASING LOW LEVEL MOISTURE FROM THE MELTED SNOW...AND
CLEAR SKIES...CONDITIONS CONTINUE TO LOOK FAVORABLE FOR FOG
FORMATION. VIS AND CEILINGS WILL REMAIN VFR THROUGH 04-06Z OR
SO...THEN GO DOWN TO IFR OR LOWER LATE TONIGHT. SOME OF THE FOG
COULD BE DENSE WITH VIS UNDER A MILE. FOG WILL BEGIN TO DISSIPATE
SOMETIME AROUND THE 15-17Z TIME FRAME.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/JR
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
245 PM CST SAT MAR 10 2012
.DISCUSSION.../ISSUED AT 300 PM CST/
ADDED LAST FIRE WEATHER ZONE TO RED FLAG WARNING PRIOR TO 19Z...AS
SOUTHERN PARTS OF THAT ZONE WERE ALSO FALLING TO BELOW 25 PERCENT RH
AND WINDS THERE GUSTING TO NEAR 25 MPH OR SLIGHTLY HIGHER. NORTHERN
PARTS OF THAT ZONE NOT LIKELY TO HIT RED FLAG CRITERIA...BUT LATEST
OBS ARE SHOWING RH VALUES AT KHON FLIRTING WITH 25 PERCENT AS OF 20Z
AS WELL. DEW POINTS HAVE BEEN SLOWLY CLIMBING ACROSS OUR SD COUNTIES
AS THE HRRR ALLUDED TO ON ITS EARLIER RUNS...WHICH LENDS CONFIDENCE
TO USING THIS FOR SOME GUIDANCE THROUGH THE EVENING HOURS. INCREASED
DEW POINTS NOT ENOUGH TO RAISE RELATIVE HUMIDITY SIGNIFICANTLY IN
OUR SOUTHWEST THOUGH...AS TEMPS WARMING INTO THE LOWER TO MID 70S
ARE KEEPING RH VALUES AT OR BELOW 20 PERCENT. SOUTHWEST MINNESOTA
NOT YET DOWN TO 25 PERCENT BUT GETTING VERY CLOSE AS OF 20Z AND
STRONGEST WINDS STILL SEEN IN THAT AREA WITH GUSTS TO 35+MPH MUCH OF
THE AFTERNOON. SO ALL IN ALL LOOKS LIKE A GOOD RED FLAG WARNING
THROUGHOUT THE AREA THIS AFTERNOON.
AS FOR TONIGHT...EXPECT DEW POINTS TO JUMP A BIT AND WIND GUSTS TO
DROP OFF WITH SUNSET...SO EXPIRATION OF RED FLAG WARNING AT 6PM
LOOKS OK. SOUTHERLY FLOW SHOULD STAY FAIRLY STEADY IN 10-15MPH MOST
AREAS TONIGHT. SLIGHTLY HIGHER SOUTH-SOUTHWEST WINDS IN HIGHER
ELEVATIONS...BUT NOT EXPECTED TO BE AS STRONG AS LAST NIGHT AS LOW
LEVEL JET NOT AS STRONG ACROSS THIS AREA. THE MODEST WINDS AND SOME
INCREASE IN LOW LEVEL MOISTURE WITH MORE SOUTHERLY LOW LEVEL FETCH
WILL HOLD TEMPS UP A BIT FROM LAST NIGHT...AND HAVE BUMPED LOWS UP A
FEW DEGREES INTO THE LOWER TO MID 40S.
APPROACH OF UPPER LOW SUNDAY WILL BRING INCREASING CLOUDS AND LOW
LEVEL MOISTURE. STILL THE INITIAL INTRUSION OF SHOWERS ALOFT WILL
HAVE TROUBLE GETTING TO THE SURFACE AND WILL CONTINUE TO LEAVE
PRECIPITATION OUT OF THE MORNING. OTHERWISE EXPECT THE UPPER LOW AND
ITS HALF DECENT DYNAMICS TO COMBINE WITH THE INCREASING MOISTURE
AND MEAGER THERMAL SUPPORT TO PRODUCE A HIGH PROBABILITY/ LOW QPF
EVENT OF RAIN FOR OUR EASTERN FORECAST AREA...THOUGH NOT SO LOW THAT
A TENTH OF AN INCH OR TWO COULD NOT BE SPIT OUT. A FEW LIGHT SHOWERS
MAY GET INTO THE WEST ALSO. TIMING IS MAINLY SUNDAY NIGHT...WITH
SYSTEM MOVING OUT STEADILY MONDAY AND DRY OVER THE AREA BY NOON. MID
AND DRY WEATHER EXPECTED FROM MONDAY AFTERNOON THROUGH MOST OF THE
FORECAST PERIOD WHICH GOES INTO THE COMING WEEKEND. STEADILY
INCREASING LOW LEVEL MOISTURE WILL PUMP UP LOW TEMPERATURES WHILE
DAYTIME HIGHS ARE IN THE 60S AND 70S. BASICALLY MID TO LATE APRIL
WEATHER. AS MAJOR TROUGH DIGS OVER THE WEST COAST THERE COULD BE A
WEAK WAVE OR TWO COME UP AHEAD OF TROUGH IN SOUTHWESTERLY UPPER
FLOW. ACCORDINGLY HAVE MENTIONED A CHANCE OF THUNDERSTORMS FOR
SATURDAY. THIS IS AHEAD OF MAIN SYSTEM AND THE DRY WARM SPELL COULD
GO THROUGH THE WEEKEND. HOWEVER THE AIR WILL BE GETTING MORE
UNSTABLE IN ADDITION TO THE MOISTURE INCREASE...SO THE GUIDANCE
INDICATION OF PRECIPITATION THREAT WILL BE FOLLOWED FOR NOW. THREAT
OF SIGNIFICANT SYSTEM AND SEVERE WEATHER EVENT CONTINUES TO BE
BEYOND FORECAST PERIOD AS 00Z GFS RUN WAS NOT ACCEPTED HERE.
/WILLIAMS
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
VFR CONDITIONS WILL PREVAIL THROUGH SUNDAY MORNING...THOUGH 3-4KFT
CEILINGS WILL BE MOVING INTO KSUX AREA LATE IN THE PERIOD AHEAD OF
ADVANCING UPPER LEVEL LOW. WINDS ARE THE GREATEST AVIATION CONCERN
FOR THIS TAF PERIOD. SOUTHWEST SURFACE GUSTS OF 25 TO 30 KTS LIKELY
THROUGH THE AFTERNOON IN MOST AREAS...STRONGEST THROUGH NORTHWEST
IOWA/SOUTHWEST MINNESOTA. FAR NORTHWEST CORNER OF THE FORECAST AREA
AROUND KHON EXPECTED TO SEE LIGHTER WIND SPEEDS. LOW LEVEL JET
INCREASES AGAIN OVERNIGHT ABOVE STRENGTHENING SURFACE INVERSION.
HOWEVER...SPEEDS ALOFT EXPECTED TO BE LOWER THAN EARLY THIS
MORNING...THUS WILL NOT HAVE MENTION OF LOW LEVEL WIND SHEAR IN
10/18Z TAFS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR IAZ300-301.
MN...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR MNZ900.
NE...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR NEZ249.
SD...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR SDZ255>258.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1118 AM CST SAT MAR 10 2012
.DISCUSSION.../ISSUED AT 1118 AM CST/
DRY RELATIVE HUMIDITY/DEW POINTS AND ASSOCIATED FIRE WEATHER
CONCERNS ARE MAIN FOCUS THIS MORNING. AS MENTIONED IN PREVIOUS
DISCUSSION...MODELS REALLY NOT HANDLING LOW LEVEL/SURFACE MOISTURE
WELL AT ALL...WITH INCOMING 12Z NAM/GFS INITIALIZING 3-6F TOO HIGH
AT 12Z...AND NAM/RUC STILL 5-8F TOO HIGH WITH 15Z DEW PONITS IN MOST
AREAS. THESE MODELS CONTINUE TO INCREASE SURFACE DEW POINTS INTO THE
30S/40S THROUGHOUT THE DAY WHICH IS DIFFICULT TO EXPLAIN GIVEN VAST
EXPANSE OF CURRENT DEW POINTS IN THE TEENS/20S THROUGH NEBRASKA AND
MOST OF KANSAS. SLIGHTLY HIGHER LOWER 30S IN SOUTHEAST KANSAS THUS
FAR THIS MORNING...BUT SOUTHWEST LOW LEVEL FLOW SHOULD KEEP THESE
VALUES SHUNTED OFF TO OUR EAST/SOUTHEAST. SO FAR THIS MORNING HRRR
SEEMS TO BE PROVIDING BEST GUIDANCE IN OUR AREA. HOWEVER...IT SHOWS
STREAM OF HIGHER DEW POINTS INTO OUR SOUTHWEST/CENTRAL CWA BY MID
AFTERNOON. EARLY HOURS OF HRRR RUNS WERE TOO MOIST IN SOURCE REGION
OF THIS MOISTURE PLUME THROUGH 16Z. HOWEVER 17Z SURFACE OBS IN THIS
REGION OVER SOUTHEAST COLORADO/FAR WESTERN KANSAS/FAR SOUTHWEST
NEBRASKA STARTING TO SHOW SOME INCREASE IN DEW POINTS SO WILL HAVE
TO MONITOR THAT AREA CLOSELY FOR THE AFTERNOON. FOR NOW...WITH LACK
OF CONFIDENCE IN ANY OF THE NEW GUIDANCE...WILL STICK WITH PREVIOUS
FORECAST FOR DEW POINTS THROUGH THE AFTERNOON. TEMPERATURES THUS FAR
HAVE BEEN RISING A LITTLE FASTER THAN FORECAST AND ADJUSTED HOURLY
GRIDS THROUGH THE EARLY AFTERNOON...BUT LITTLE CHANGE TO GOING HIGHS
AT THIS TIME. WINDS ALSO PRETTY MUCH ON TRACK WITH ALL AREAS EXCEPT
MIDDLE JAMES RIVER VALLEY SEEING GUSTS IN 20-30KT RANGE AS OF 17Z.
WITH GUSTINESS ALSO EXPECTED ACROSS MIDDLE BIG SIOUX VALLEY/I-29
CORRIDOR NEAR/NORTH OF SIOUX FALLS...OPTED TO ADD SDZ257 INTO THE
EXISTING RED FLAG WARNING. ALSO PULLED THE START TIME BACK TO LATE
MORNING AS SOUTHERN AREAS ALREADY SEEING RH VALUES DROPPING BELOW 25
PERCENT AND EASTERN AREAS ALREADY GUSTING OVER 30MPH. UPDATED GRIDS
HAVE BEEN SENT...AND UPDATED FIRE WEATHER PRODUCTS OUT. NO UPDATES
TO ZFP/PFM AT THIS TIME.
&&
.PREV DISCUSSION.../ISSUED AT 400 AM CST/
MAIN CONCERN TODAY IS FIRE WEATHER WITH MILD AND DRY AIRMASS
SPREADING ACROSS THE AREA. 00Z SOUNDINGS FROM UPSTREAM IN
KLBF...KDDC...KTOP AND KOMA QUITE DRY IN THE LOW LEVELS. MODELS
SUGGEST WEAK LOW LEVEL MOISTURE TRANSPORT INCREASING AFTER 18Z
ACROSS THE AREA. MODEL SOUNDINGS ARE SUFFERING MIXING ISSUES...AND
THEREFORE DEW POINT GUIDANCE WAS MUCH HIGHER THAN ANY OF THE
OBSERVATIONS WOULD SUGGEST. AS SUCH...CUT DEW POINTS BY 10-15
DEGREES OVER GUIDANCE. WITH STRONG SOUTHWESTERLY WINDS IN THE SOUTH
AND EASTERN PORTIONS OF THE FORECAST AREA...HAVE WENT AHEAD AND
UPGRADED MUCH OF THE AREA TO RED FLAG WARNING. DID NOT INCLUDE THE
TWO NORTHWEST ZONES IN EASTERN CENTRAL SOUTH DAKOTA AS WINDS WILL BE
WEAKER THERE. RH VALUES WILL STILL PROMOTE VERY HIGH TO EXTREME FIRE
DANGER ACROSS THE ENTIRE AREA.
SOUTHWEST WINDS ARE EXPECTED TO DECREASE THIS EVENING...AND AS THEY
TAKE ON A MORE PURE SOUTHERLY FLAVOR SHOULD SEE FAIRLY HEARTY
MOISTURE RETURN TO THE AREA. GUSTY SOUTHERLY WINDS WILL CONTINUE
ACROSS THE AREA ON SUNDAY AS UPPER LEVEL LOW APPROACHES FROM THE
FOUR CORNERS REGION. HAVE INCREASED POPS EAST OF THE JAMES RIVER
VALLEY WITH THIS FEATURE.
THEREAFTER...CONDITIONS RETURN TO WARM AND DRY WITH STRONG SOUTHERLY
WINDS ACROSS THE AREA. WILL LIKELY SEE ADDITIONAL FIRE WEATHER
CONCERNS THEN...AS HIGH TEMPERATURES APPROACH NEAR RECORD LEVELS.
IN THE LATTER PERIODS(WEDNESDAY THROUGH FRIDAY)...A WARM
PATTERN...FAIRLY WELL AGREED UPON BY THE VARIOUS MODELS...WITH FLAT
RIDGING EARLY BECOMING A LITTLE MORE PRONOUNCED LATE. A WEAK WAVE
NEAR THE CANADIAN BORDER WILL ALLOW A WEAK COLD FRONT TO SLIP SOUTH
ON WEDNESDAY WHICH WILL DO LITTLE MORE THAN DECREASE HIGHS IN THE
UPPER 50S TO MID 60S. AFTER THIS HIGH PRESSURE WILL SHIFT EAST AND
ALLOW SOUTHERLY FLOW TO DEVELOP GRADUALLY FROM THURSDAY INTO
FRIDAY...LIKELY BECOMING A BIT BREEZY FRIDAY. OTHERWISE...LOWS
MAINLY IN THE 40S WITH HIGHS IN THE 70S. /08
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
VFR CONDITIONS WILL PREVAIL THROUGH SUNDAY MORNING...THOUGH 3-4KFT
CEILINGS WILL BE MOVING INTO KSUX AREA LATE IN THE PERIOD AHEAD OF
ADVANCING UPPER LEVEL LOW. WINDS ARE THE GREATEST AVIATION CONCERN
FOR THIS TAF PERIOD. SOUTHWEST SURFACE GUSTS OF 25 TO 30 KTS LIKELY
THROUGH THE AFTERNOON IN MOST AREAS...STRONGEST THROUGH NORTHWEST
IOWA/SOUTHWEST MINNESOTA. FAR NORTHWEST CORNER OF THE FORECAST AREA
AROUND KHON EXPECTED TO SEE LIGHTER WIND SPEEDS. LOW LEVEL JET
INCREASES AGAIN OVERNIGHT ABOVE STRENGTHENING SURFACE INVERSION.
HOWEVER...SPEEDS ALOFT EXPECTED TO BE LOWER THAN EARLY THIS
MORNING...THUS WILL NOT HAVE MENTION OF LOW LEVEL WIND SHEAR IN
10/18Z TAFS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR IAZ300-301.
MN...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR MNZ900.
NE...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR NEZ249.
SD...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR SDZ255-257-258.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
635 PM CDT SUN MAR 11 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY
255 PM CDT SUN MAR 11 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION TONIGHT INTO MONDAY AS
WELL AS THE ABOVE NORMAL TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED AN UPPER TROUGH FROM THE NORTHEAST PACIFIC INTO THE PACIFIC
NORTHWEST...THEN ZONAL FLOW FROM MANITOBA EAST INTO QUEBEC. IN THE
SOUTHERN STREAM...AN UPPER LOW WAS OVER THE OKLAHOMA PANHANDLE WITH
RIDGING BUILDING DOWNSTREAM INTO THE UPPER MISSISSIPPI RIVER VALLEY
REGION. AHEAD OF THE UPPER LOW...SHOWERS AND EMBEDDED THUNDERSTORMS
EXTENDED FROM FAR SOUTHWEST IOWA INTO KANSAS...MISSOURI AND SOUTH TO
THE GULF COAST. THE PRECIPITATION WAS BEING FORCED FROM A NUMBER OF
FACTORS: DPVA AHEAD OF THE UPPER LOW THE BIG ONE...A STREAM OF LOW
LEVEL MOISTURE TRANSPORT NOTED BY 30-40 KT 925-850MB WINDS ON
PROFILER DATA...INSTABILITY PRODUCED BY DAYTIME HEATING ACTING WITH
THE UPPER LOW AND SURFACE DEWPOINTS CLIMBING INTO THE 40S AND 50S.
PRECIPITABLE WATER VALUES IN THE MOISTURE STREAM ARE 1-1.5 INCHES OR
200-270 PERCENT OF NORMAL PER 12Z RAOBS. OVER THE FORECAST
AREA...DRY AIR ON THE 12Z MPX AND DVN SOUNDINGS HAVE KEPT ANY CLOUD
COVERAGE AHEAD OF THE PRECIPITATION LIMITED TO CIRRUS AND MID-LEVEL
CLOUDS THUS FAR...AND THESE ARE JUST COMING INTO LOCATIONS ALONG AND
SOUTH OF I-90. WITH PLENTY OF SUN...850MB TEMPS BETWEEN 8-10C PER
12Z RAOB ANALYSIS AND A RELATIVELY BREEZY SOUTH WIND...TEMPERATURES
HAVE CLIMBED AGAIN INTO THE 60S TODAY.
TONIGHT AND MONDAY...UPPER LOW OVER THE CENTRAL PLAINS IS FORECAST
TO LIFT NORTHEAST...CROSSING THE AREA SHORTLY AFTER 12Z MONDAY...
THEN REACH LAKE SUPERIOR BY 00Z TUESDAY. THIS EJECTION IS IN
RESPONSE TO THE TROUGHING CURRENTLY OVER THE PACIFIC NORTHWEST
LIFTING INTO MANITOBA. PRETTY IMPRESSIVE 500MB HEIGHT FALLS PROGGED
TONIGHT INTO MONDAY MORNING...ANYWHERE BETWEEN 150 AND 200 METERS.
SO NEEDLESS TO SAY THE DYNAMIC FORCING IS REALLY STRONG. A STRONG
SURGE OF MOISTURE COMES UP AHEAD OF THE LOW...SEEN IN PRECIPITABLE
WATER PROGS OF AROUND 1 INCH OR 300 PERCENT OF NORMAL. THEREFORE...
THE DYNAMICS SHOULD HAVE NO PROBLEM BRINGING PRECIPITATION TO THE
AREA. DESPITE THE ABOVE NORMAL MOISTURE...NOT ANTICIPATING THIS TO
BE A HEAVY QPF EVENT FOR A NUMBER OF REASONS: THE HIGH AMOUNT OF
MOISTURE DOES NOT STICK AROUND LONG DUE TO THE UPPER LOW MOVING
QUICKLY...MUCAPE FROM THE NAM FOR MUCH OF THIS TIME PERIOD STAYS
BELOW 200 J/KG LIMITING THUNDERSTORMS TO ISOLATED AT BEST...NO UPPER
JET SUPPORT AND BEST 850MB MOISTURE TRANSPORT AIMED EAST OF HERE.
WHAT INSTABILITY DOES EXIST IS OVER WISCONSIN DURING THE DAY
MONDAY...THUS HAVE KEPT A SLIGHT CHANCE FOR THUNDER THEN. REGARDING
PRECIPITATION TRENDS IN THE FORECAST...SHOULD SEE SHOWERS MOVE IN
THIS EVENING OVER MUCH OF THE FORECAST AREA...THEN BECOME MORE
SCATTERED ON MONDAY AS THE UPPER LOW PULLS AWAY BUT ITS COLD POOL
ALOFT LINGERS. TEMPERATURES ARE LIKELY TO REMAIN MILD TONIGHT WITH
CLOUDS AND HIGHER DEWPOINTS MOVING IN. LITTLE CHANGE REQUIRED FOR
LOWS. HIGHS ON MONDAY ARE TRICKY GIVEN THAT ONLY SUN POTENTIAL WOULD
OCCUR IN THE AFTERNOON AND SOUTH OF I-90. FOR NOW STUCK WITH A BLEND
OF GUIDANCE...BUT IF CLOUDS STAY AROUND LONGER THAN FORECAST...HIGHS
MAY NEED TO BE COOLED.
MONDAY NIGHT THROUGH WEDNESDAY...UPPER LOW IS PROGGED TO MOVE
FURTHER AWAY FROM THE REGION WHILE A FEW NEW TROUGHS DROP DOWN INTO
THE PACIFIC NORTHWEST AND EJECT UP INTO CENTRAL CANADA. THE RESPONSE
OF ALL OF THIS IS TO BUILD RIDGING OVER THE UPPER MISSISSIPPI RIVER
VALLEY REGION...SENDING A SURGE OF WARMER AIR INTO THE FORECAST
AREA. 850MB TEMPS WHICH START OFF AT 4-8C AT 12Z TUESDAY ARE
FORECAST TO CLIMB TO 8-12C BY 00Z WEDNESDAY AND TO 12-14C FOR THE
WHOLE DAYTIME HOURS ON WEDNESDAY. THERE ARE EVEN SOME HINTS OF 16C
850MB TEMPS APPROACHING THE WESTERN PORTION OF THE FORECAST AREA ON
WEDNESDAY...AHEAD OF A DYING SURFACE COLD FRONT COMING INTO
MINNESOTA. THESE 850MB READINGS ARE 2-2.5 STANDARD DEVIATIONS ABOVE
NORMAL...FAVORING TEMPERATURES APPROACHING OR EXCEEDING RECORD HIGHS
GIVEN TOO THAT PLENTY OF SUN SHOULD OCCUR BOTH DAYS. LEANED TOWARDS
THE HIGH END OF ALL GUIDANCE AS A RESULT FOR HIGHS. SOME
PRECIPITATION NOTES. THE 11.12Z NAM SHOWS ELEVATED CONVECTION
BETWEEN 09-15Z WEDNESDAY OVER EASTERN IOWA AND FAR SOUTHWEST
WISCONSIN. THIS PRECIPITATION FORMS DUE TO THE PRESENCE OF A WEAK
SHORTWAVE...A WARM FRONT AND ELEVATED CAPE VALUES BETWEEN 1000-1500
J/KG. HOWEVER...THE 850MB DEWPOINT HELPING TO PRODUCE THIS CAPE IS
AROUND 10C...OR 8C HIGHER THAN THE ECMWF. THE GFS IS ALSO SLIGHTLY
LOWER. THEREFORE AM DISCOUNTING THE NAM AT THE PRESENT TIME. ON
WEDNESDAY...THE GFS SEEMS TO HAVE TOO MUCH MOISTURE AT AND BELOW
900MB...A KNOWN PROBLEM SEEN IN SOME RECENT WARM EVENTS...AND THUS
STRATUS AND DRIZZLE OUT. DISCOUNTING THIS SCENARIO AS WELL SINCE IT
DOES NOT AGREE WITH THE ECMWF/NAM/CANADIAN. LASTLY...ON WEDNESDAY
AFTERNOON THE NAM CONVECTS OVER EASTERN IOWA AND SOUTHERN
WISCONSIN...THOUGH THERE IS NO SURFACE TRIGGER. IN ADDITION...THE
MODEL BRINGS SURFACE DEWPOINTS INTO THE 60S WHICH SEEMS WAY TOO
HIGH. AS SUCH...HAVE FOLLOWED THE DRY ECMWF/CANADIAN SCENARIO.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
255 PM CDT SUN MAR 11 2012
GOOD MODEL AGREEMENT EXISTS THAT THE FLOW OF TROUGHS COMING INTO THE
PACIFIC NORTHWEST THEN LIFTING INTO NORTH CENTRAL CANADA PERSISTS
THROUGH THURSDAY NIGHT. THEN ON FRIDAY AND HEADING INTO THE
WEEKEND...ALL MODELS SHOW A REALLY DEEP TROUGH FORMING ALONG THE
WEST COAST OF THE U.S. THE 11.12Z GFS IS BY FAR THE MOST PROGRESSIVE
WITH A STRONG SHORTWAVE COMING OUT OF THIS TROUGH...RESULTING IN A
FRONT MOVING THROUGH THE AREA AT 12Z SUNDAY. THE 11.00Z/12Z ECMWF
AND 11.12Z CANADIAN KEEPS THIS SHORTWAVE WRAPPED IN THE TROUGH WHICH
SEEMS MORE REASONABLE. BASICALLY ALL THIS MEANS IS THAT THE FORECAST
AREA STAYS UNDER UPPER RIDGING AND IN THE WARM SECTOR. THERE IS ONE
POTENTIAL CAVEAT TO THE WARM SECTOR WHICH IS THE COLD FRONT FROM
WEDNESDAY OVER MINNESOTA. MODELS PROG THIS FRONT TO DIE AS IT COMES
INTO THE FORECAST AREA WEDNESDAY NIGHT AND THURSDAY...WHILE BECOMING
ORIENTED MORE WEST-EAST WITH THE UPPER FLOW. AT THIS TIME HAVE
MAINTAINED A CONSENSUS 20 PERCENT CHANCES FOR PRECIPITATION ON THUS
FRONT OVER SOUTHWEST WISCONSIN WEDNESDAY NIGHT...THEN IN NORTHEAST
IOWA ON THURSDAY. STILL...THINKING MUCH OF THIS PERIOD WILL END UP
DRY. AFTER THIS...IT BECOMES A LITTLE MORE DIFFICULT TO PINPOINT
WHEN PRECIPITATION OCCURS. AS THE UPPER LEVEL FLOW AMPLIFIES...THERE
ARE INDICATIONS OF A FEW SHORTWAVES RIDING THROUGH DURING THE FRIDAY
THROUGH SATURDAY NIGHT TIME PERIOD. DEPENDING ON THE MODEL THE
TIMING VARIES. FOR NOW HAVE STAYED WITH A CONSENSUS APPROACH WHICH
RESULTS IN MUCH OF THE FORECAST AREA HAVING 20-40 PERCENT CHANCES.
STRONGER UPPER RIDGING ON SUNDAY SHOULD PREVENT ANY PRECIPITATION.
THE MAIN STORY CONTINUES TO BE THE WARMTH. 850MB TEMPS ON AVERAGE
HOLD BETWEEN 10-14C...OR 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL.
THIS SHOULD HELP TO KEEP HIGH TEMPERATURES MOSTLY IN THE 70S AND
NEAR OR ABOVE RECORDS. PERHAPS THE ONLY EXCEPTION TO THIS MIGHT BE
ON THURSDAY OVER NORTH CENTRAL WISCONSIN ON THE NORTH SIDE OF THAT
DYING COLD FRONT. ALSO OF NOTE IS THAT LOW TEMPERATURES ARE GOING TO
BE VERY WARM FOR THIS TIME OF YEAR TOO...AIDED BY DEWPOINTS HOLDING
MAINLY IN THE 50S. IN FACT...LOWS COULD BE 10-15 DEGREES ABOVE
NORMAL HIGHS.
&&
.AVIATION...TONIGHT AND MONDAY
635 PM CDT SUN MAR 11 2012
UPPER LEVEL LOW OVER SOUTHWEST KANSAS WILL LIFT NORTHEAST
OVERNIGHT AND BE LOCATED ALONG THE IOWA/MINNESOTA BORDER AT 12Z
MONDAY AND INTO NORTHWEST WISCONSIN BY 18Z MONDAY. 11.18Z NAM AND
11.21Z RUC IN GOOD AGREEMENT WITH MOISTURE TRANSPORT NOSING INTO
THE TAF SITES BETWEEN 03Z-06Z. THUS EXPECT CEILINGS TO DROP FROM
VFR INTO THE IFR CATEGORY AS SHOWERS MOVE INTO BOTH SITES. SOME
LIFR CEILINGS LIKELY AT KRST. THESE CONDITIONS WILL THEN CONTINUE
THROUGH 16Z-18Z BEFORE THE SHOWERS BECOME LIGHTER AND CEILINGS LIFT
INTO THE LOWER MVFR CATEGORY AS THE LOW PULLS NORTH OF THE AREA.
&&
.CLIMATE...
255 PM CDT SUN MAR 11 2012
RECORD HIGHS HAVE BEEN BROKEN AT KLSE AND KRST...JUST BARELY WITH
ONLY BEING 1 DEGREE ABOVE THEM...BUT RECORDS NONETHELESS. POTENTIAL
STILL EXISTS FOR A DEGREE OR TWO RISE SO RECORD EVENT REPORTS WILL
BE HELD UNTIL DAYTIME HEATING ENDS AROUND 5 PM.
BEING NEAR OR AT RECORDS FOR HIGHS WILL BE THE NORM HERE STARTING
TUESDAY AND LASTING PERHAPS INTO EARLY NEXT WEEK. AN ANOMALOUS WARM
PATTERN IS SETTING UP OVER THE FORECAST AREA. LOW TEMPERATURES COULD
EVEN BE HIGH ENOUGH THAT WE SET NEW RECORD HIGH MINIMUMS. SEE OUR
WEBSITE FOR DETAILS ON RECORD HIGHS.
&&
.HYDROLOGY...THROUGH MONDAY
255 PM CDT SUN MAR 11 2012
NOT MUCH IN THE WAY OF ANY CHANGES TO THE GOING FORECAST. SNOWPACK
IN TAYLOR COUNTY IS IN FULL MELT MODE NOW / PER NOHRSC SNOW PACK
TEMPERATURE ANALYSIS / AND WILL CONTINUE TO MELT DURING THE NEXT
COUPLE OF DAYS. FORECAST RAINFALL AMOUNTS ARE STILL IN THE 0.35 TO
0.60 INCH RANGE WHICH WILL LIKELY LEAD TO SOME RISES ALONG THE
BLACK AND TREMPEALEAU RIVERS...BUT STILL NOT UP TO FLOOD STAGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
255 PM CDT SUN MAR 11 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
CLIMATE...AJ
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
252 PM CST SAT MAR 10 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY
252 PM CST SAT MAR 10 2012
MAIN FORECAST CONCERNS ARE ON THE EXPECTED PRECIPITATION SUNDAY
NIGHT AND MONDAY...ALONG WITH TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED THE MAIN BELT OF THE WESTERLIES TRAVERSING FROM THE PACIFIC
NORTHWEST INTO SOUTH CENTRAL CANADA...THEN DOWN INTO TROUGHING OVER
NEW ENGLAND. HOWEVER...IN THE SOUTHERN STREAM...AN UPPER LOW WAS
PRESENT OVER NEW MEXICO WITH RIDGING BUILDING UP AHEAD OF IT OVER THE
MISSISSIPPI RIVER VALLEY. MOISTURE SO FAR AHEAD OF THIS UPPER LOW
HAS ADVECTED INTO OKLAHOMA...NOTED BY SHOWERS...LOWER LEVEL STRATUS
AND DEWPOINTS IN THE LOW TO MID 30S. A MUCH DIFFERENT SITUATION
EXISTS ACROSS THE UPPER MIDWEST INTO OUR REGION...THOUGH. 12Z
SOUNDINGS FROM BIS...ABR...OAX AND MPX ALL DEPICTED A VERY DRY
ATMOSPHERE. 850MB TEMPS HAVE WARMED FAIRLY DRAMATICALLY SINCE LAST
NIGHT TOO...WITH MPX JUMPING FROM -1C AT 00Z TO 13C AT 12Z. PLENTY
OF SUNSHINE...BREEZY SOUTHWEST WINDS WITH GUSTS FROM 30 TO 45 MPH
AND THE DRY AIR HAS ALLOWED FOR TEMPERATURES TO CLIMB INTO THE 60S
OVER MUCH OF THE FORECAST AREA. EXCEPTION TO THIS IS OVER THE
SNOWPACK IN TAYLOR COUNTY WHERE READINGS ARE STILL IN THE MID 50S.
DEWPOINTS HAVE STRUGGLED TO FALL MUCH SO FAR EARLY THIS AFTERNOON...
THOUGH. THINKING THIS IS DUE TO MOISTURE STILL IN THE SOIL
EVAPOTRANSPIRATING. CONDITIONS ARE STILL CONDUCIVE FOR FIRES...
THOUGH...NOTED BY A FIRE THAT OCCURRED NEAR MANKATO MN SEEN ON MPX
RADAR.
TONIGHT AND SUNDAY...TROUGHING OVER THE NORTHEAST PACIFIC IS PROGGED
TO SLIDE INTO THE PACIFIC NORTHWEST...CAUSING THE UPPER LOW IN NEW
MEXICO TO LIFT UP INTO THE CENTRAL PLAINS. THE SPEED OF THIS UPPER
LOW EJECTION HAS REMAINED NEARLY CONSISTENT FOR THE PAST FEW
DAYS...THOUGH THE SPEED AT WHICH MOISTURE/PRECIPITATION AHEAD OF THE
UPPER LOW HAS SLOWED DOWN. IN FACT...THE 10.12Z ECMWF...GFS...NAM...
CANADIAN AND UKMET ARE ALL NOW DRY FOR SUNDAY. GIVEN THE CURRENT DRY
AIRMASS...THINK THE DRIER TREND IS THE WAY TO GO AND REMOVED ANY
PRECIPITATION CHANCES FOR SUNDAY. WE SHOULD SEE SOME MID/HIGH CLOUD
COVER ADVECT IN FROM THE SOUTH DURING THE DAY SUNDAY...THOUGH. A
WEAKER PRESSURE GRADIENT IS PROGGED TONIGHT THAN WHAT OCCURRED THIS
MORNING...BUT A 5 TO 15 MPH SOUTHWEST WIND LOOKS TO PERSIST. THE
WIND WILL HELP TO KEEP TEMPERATURES UP SOMEWHAT...THOUGH THE DRY
AIRMASS DOES LEND ITSELF FOR BETTER RADIATIONAL COOLING.
THEREFORE...HAVE KEPT THE PREVIOUS FORECAST LOWS ABOUT THE SAME.
HIGHS ON SUNDAY ARE TRICKY BECAUSE OF THE INCOMING CLOUDS. CERTAINLY
THE DRY AIR AND A SOUTH TO SOUTHWEST WIND ARE HELPFUL TO HAVE
ANOTHER WARM DAY...IN ADDITION TO 850MB TEMPS HOLDING BETWEEN 8-10C.
DECIDED TO LEAN TOWARDS A BLEND OF THE MET/ECMWF/REGIONAL CANADIAN
GUIDANCE GIVEN GOOD PERFORMANCE IN THESE ABOVE NORMAL SCENARIOS.
SUNDAY NIGHT AND MONDAY...THE UPPER LOW IS FORECAST TO CONTINUE
EJECTING NORTHEASTWARD...CROSSING THE FORECAST AREA MONDAY MORNING.
BY 00Z TUESDAY...THE UPPER LOW SHOULD BE LOCATED OVER EASTERN LAKE
SUPERIOR. IMPRESSIVE CHANGE IN 500MB HEIGHTS FOR THE FORECAST AREA.
FROM 00-12Z MONDAY...THESE HEIGHTS FALL AROUND 150 METERS. SO
DEFINITELY GOOD FORCING IN THIS TIME PERIOD FOR PRECIPITATION. ON
THE FLIP SIDE...BETWEEN 12Z MONDAY-00Z TUESDAY...THE HEIGHTS RISE
40-100 METERS...INDICATING DECENT SUBSIDENCE. WHEN LOOKING AT MODEL
QPF OUTPUT THE SAME SIGNAL SHOWS UP...WHERE SHOWERS SPREAD SOUTH TO
NORTH SUNDAY NIGHT...THEN END SOUTHWEST TO NORTHEAST MONDAY. VERY
GOOD AGREEMENT EXISTS AMONGST THE MODELS FOR PRECIPITATION...SO HAVE
RAISED PRECIPITATION CHANCES UP TO 100 WITH A LITTLE EXTRA TIMING
INFORMATION INCLUDED. AS FAR AS QPF AMOUNTS GO...PRECIPITABLE WATER
VALUES CLIMB TO 250-300 PERCENT OF NORMAL...THOUGH MUCH OF THE LOW
LEVEL MOISTURE TRANSPORT ENDS UP SHUNTED OFF TO THE EAST. VERY
LITTLE IF ANY CAPE IS PROGGED DUE TO MOIST ADIABATIC LAPSE RATES. NO
HINTS AT ANY UPPER JET FORCING EITHER. THEREFORE...THINK QPF AMOUNTS
OVERALL WILL BE FAIRLY LIGHT...ON THE ORDER OF 0.25-0.5 INCHES. WITH
THE MOISTURE COMING UP...EXPECT LOWS TO STAY ON THE MILD SIDE SUNDAY
NIGHT. ON THE OTHER HAND...THE CLOUDS AND PRECIPITATION WILL TEND TO
KEEP THINGS COOLER ON MONDAY...RELATIVELY SPEAKING FOR MID MARCH
GIVEN THAT HIGHS ARE STILL GOING TO BE WELL ABOVE NORMAL.
MONDAY NIGHT AND TUESDAY...500MB HEIGHTS ARE PROGGED TO RISE
FURTHER...DUE TO THE UPPER LOW MOVING FARTHER AWAY...AND YET ANOTHER
UPPER TROUGH FORECAST TO DIG INTO THE PACIFIC NORTHWEST. AS
SUCH...WE GET A SURGE OF WARMER AIR AT 850MB TEMPS TO ADVECT INTO
THE FORECAST AREA...CLIMBING FROM 6-10C AT 12Z TUESDAY TO 10-12C AT
00Z WEDNESDAY. OTHER THAN A LITTLE LINGERING STRATUS EARLY MONDAY
NIGHT IN THE WAKE OF THE UPPER LOW...AS WELL AS A FEW MID CLOUDS TO
PASS THROUGH THE AREA ON TUESDAY...MUCH OF THIS TIME PERIOD LOOKS TO
BE CLEAR. IN FACT...SOUNDINGS ON TUESDAY LOOK PRETTY DRY WHICH
SHOULD ALLOW US TO WARM NICELY. SO AFTER A NIGHT IN THE MID 30S TO
LOW 40S MONDAY NIGHT...ANTICIPATING TEMPERATURES TO REBOUND BACK
WELL INTO THE 60S. IN FACT...SOME LOCATIONS COULD REACH 70...
ESPECIALLY IN FAR WESTERN SECTIONS.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
252 PM CST SAT MAR 10 2012
AS STATED IN PREVIOUS DISCUSSIONS AND STILL HOLDS TRUE...THE MAIN
STORY IS THE WELL ABOVE NORMAL WARMTH. PRETTY MUCH THE ENTIRE LONG
TERM PERIOD...ACCORDING TO ALL 10.00Z/12Z MODELS...FEATURES
SOUTHWEST FLOW FROM SAY NORTHERN CALIFORNIA INTO HUDSON BAY...
ALLOWING FOR RIDGING AND DOWNSLOPED PACIFIC AIR TO DOMINATE THE
EASTERN TWO THIRDS OF THE U.S.. TOWARDS THE WEEKEND...THE SOUTHWEST
FLOW AMPLIFIES OVER THE WESTERN U.S. AS DEEP TROUGHING FORMS ALONG
THE WEST COAST. IF ANYTHING...THIS COULD SEND EVEN WARMER AIR
TOWARDS THE FORECAST AREA. 850MB TEMPS THROUGHOUT THE LONG TERM
PERIOD ARE PROGGED AT 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL. AS
SUCH...WE COULD BE DEALING WITH TEMPERATURES AT OR ABOVE RECORD
HIGHS EVERY DAY. IN GENERAL 850MB TEMPS HOLD BETWEEN 10-14C...WITH
THE WARMEST OF THESE ON WEDNESDAY. WITH WHAT LOOKS TO BE PLENTY OF
SUNSHINE THROUGHOUT...STAYED TOWARDS THE HIGH END OF ALL AVAILABLE
GUIDANCE AND FORECASTED HIGHS FROM THE UPPER 60S TO LOW 70S. THESE
ARE READINGS ARE MORE SIMILAR OF MID MAY THAN MID MARCH.
REGARDING PRECIPITATION CHANCES...THESE ARE RESTRICTED TO WEDNESDAY
NIGHT AND THEN FRIDAY THROUGH SATURDAY. FOR WEDNESDAY NIGHT...A
DYING COLD FRONT PROGGED TO MOVE THROUGH THE EASTERN PART OF THE
FORECAST AREA. NOT SURE IF THIS FRONT WILL CONVECT...BUT THE 10.12Z
ECMWF DOES SHOW A SHORTWAVE MOVING THROUGH THE FLOW ALOFT. THIS
SHORTWAVE COMBINED WITH A STREAM OF 850MB MOISTURE TRANSPORT AND
INSTABILITY COULD RESULT IN SOME CONVECTION. MAINTAINED JUST A 20
PERCENT CHANCE IN FAR SOUTHWEST WISCONSIN. FOR FRIDAY THROUGH
SATURDAY...A STREAM OF MOISTURE AND INSTABILITY COMING UP OUT OF THE
GULF OF MEXICO MAY COMBINE WITH SOME SHORTWAVES MOVING THROUGH THE
SOUTHWEST FLOW ALOFT TO INITIATE CONVECTION. HARD TO TIME AND EXACT
DETAILS VERY UNCERTAIN...THUS CHANCES ARE KEPT AT A MODEL CONSENSUS
20-40 VALUE.
IF THE CFS MODEL IS RIGHT...WHICH IT HAS BEEN DOING FAIRLY WELL THE
PAST FEW MONTHS...THE WELL ABOVE NORMAL WARMTH LOOKS TO PERSIST
THROUGH THE END OF THE MONTH AND INTO THE BEGINNING OF APRIL.
CERTAINLY IN THE LATEST 10.12Z ECMWF...THE WARM AIR AT LEAST STICKS
AROUND THROUGH NEXT MONDAY AND LIKELY WELL BEYOND.
&&
.AVIATION...THROUGH 18Z SUNDAY
1125 AM CST SAT MAR 10 2012
BIGGEST CONCERN THROUGH THE PERIOD IS WIND THROUGH THIS AFTERNOON.
TIGHT PRESSURE GRADIENT AND MIXING THROUGH 875MB YIELDING GUSTY
SOUTHWEST WINDS IN THE 20-30 MPH RANGE WITH GUSTS APPROACHING 40
MPH. THESE WINDS ARE EXPECTED TO SUBSIDE RAPIDLY BY SUNSET AND
WITH LOSS OF HEATING/MIXING. OTHERWISE...VFR/CLEAR CONDITIONS EXPECTED
TONIGHT...THEN WILL SEE A SLOW INCREASE IN MID/HIGH LEVEL CLOUDS
AFTER 15Z SUNDAY AS A MID-LEVEL LOW MOVES OUT OF THE DESERT
SOUTHWEST TOWARD THE CENTRAL PLAINS. ONSET OF RAIN FROM THIS
SYSTEM EXPECTED TO BE AT THE KRST/KLSE TAF SITES SOMETIME SUNDAY
EVENING...THEN LASTING INTO MONDAY AS THE MID-LEVEL LOW PASSES
OVER THE REGION. APPEARS THERE WILL BE LOWERING OF
CEILING/VISIBILITY ASSOCIATED WITH THIS SYSTEM WITH BETTER DETAILS
FORTHCOMING IN LATER TAF ISSUANCES.
&&
.CLIMATE...THROUGH SATURDAY
252 PM CST SAT MAR 10 2012
WE ARE APPROACHING RECORD HIGHS THIS AFTERNOON. WITH A FEW MORE
HOURS TO GO...POTENTIAL EXISTS FOR EITHER TYING OR BREAKING.
STATIONS THAT HAVE LONG PERIODS OF RECORD...OVER 115 YEARS...1894
RECORDS EXIST FOR DECORAH /66F/...LA CROSSE /67F/...MEDFORD
/53F/...AND WINONA /64F/. MEANWHILE THOSE WITH SHORTER DATA
BASES...THE TEMPERATURES WILL THREATEN RECORDS EITHER SET IN 1967
OR 1977.
LOOKING AHEAD...A STRING OF NEAR RECORDS OR RECORD HIGHS APPEAR
LIKELY FOR TUESDAY THROUGH SATURDAY...AND COULD EVEN GO BEYOND
THIS. IN ADDITION...WE COULD ALSO APPROACH OR BREAK RECORD HIGH
MINIMUMS. AN ABNORMALLY STRONG RIDGE AND WARM AIR IS PROGGED TO
REMAIN IN PLACE OVER THE EASTERN TWO THIRDS OF THE FORECAST AREA.
READINGS LOOK TO BE MORE SIMILAR OF MID MAY VERSUS MID MARCH. STAY
TUNED TO SEE HOW WARM WE ACTUALLY GET. RECORDS HAVE BEEN POSTED ON
OUR WEBSITE.
&&
.HYDROLOGY...THROUGH MONDAY
252 PM CST SAT MAR 10 2012
SIMILAR TO THE EARLIER HYDROLOGY DISCUSSION...SOME MINOR CONCERNS
ABOUT WHETHER ANY FLOODING WILL OCCUR ACROSS NORTH CENTRAL WISCONSIN
AS A RESULT OF A MELTING SNOW PACK AND RAIN SUNDAY NIGHT INTO
MONDAY. QPF AMOUNTS ARE STILL FORECAST BETWEEN 0.25-0.5 INCHES OVER
A LONG PERIOD WITH NO THUNDERSTORMS EXPECTED TO OCCUR. WITH GRADUAL
MELTING DUE TO THE WARMER TEMPERATURES...CURRENTLY EXPECT TO SEE
SOME RIVER RISES ALONG THE BLACK AND MAYBE TREMPEALEAU RIVERS...BUT
PROBABLY NOT UP TO FLOOD STAGE AT THIS POINT.
&&
.FIRE WEATHER...THROUGH SUNDAY
252 PM CST SAT MAR 10 2012
RED FLAG CONDITIONS WILL CONTINUE INTO EARLY THIS EVENING WEST OF
THE MISSISSIPPI RIVER. RELATIVE HUMIDITIES HAVE FALLEN TO 25 TO 30
PERCENT AS OF 20Z AND A LITTLE MORE FALL IS EXPECTED DURING THE NEXT
FEW HOURS. WINDS REMAIN BLUSTERY WITH GUSTS OF 30 TO 40 MPH OUT OF
THE SOUTHWEST. WITH LOSS OF HEATING THIS EVENING...ANTICIPATING
CONDITIONS TO IMPROVE FAIRLY RAPIDLY.
LOOKING AHEAD TO SUNDAY...MORE MOISTURE STREAMING FROM THE SOUTH AND
INCREASING CLOUDS IN THE AFTERNOON SHOULD KEEP THE RELATIVE
HUMIDITIES FROM DROPPING BELOW 30 PERCENT. LOWEST HUMIDITIES ARE
PLANNED OVER SOUTHWEST WISCONSIN...WHICH IN THIS AREA THE FUELS ARE
A LITTLE MORE MOIST. WINDS ARE ALSO EXPECTED TO BE QUITE A BIT
LIGHTER THAN THOSE SEEN TODAY. THEREFORE...CONDITIONS FOR FIRES WILL
NOT BE AS GOOD AS THEY WERE TODAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
252 PM CST SAT MAR 10 2012
WI...NONE.
MN...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR MNZ079-086>088-
094>096.
IA...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS
CLIMATE...BOYNE/AJ
HYDROLOGY...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1156 AM CST SAT MAR 10 2012
.UPDATE...WIND ADVISORY ISSUED THIS MORNING FOR NORTHEAST
COUNTIES...AS LATEST SOUNDINGS SHOWING UP TO 45 MPH IN THE TOP
HALF OF THE MIXING LAYER. GFS AND RUC SOUNDS ARE PARTICULARLY
AGGRESSIVE...SUGGESTING GUSTS TO NEARLY 50 MPH POSSIBLE THIS
AFTERNOON. HAVE ALREADY SEEN GUSTS AS HIGH AS 43 MPH AT FOND DU
LAC...SO APPEARS THAT THINGS ARE ON THEIR WAY. WINDS WILL
EVENTUALLY EASE LATE THIS AFTERNOON AND INTO THE EVENING AS
DAYTIME MIXING IS LOST.
WITH RELATIVELY CALM UPPER LEVEL FLOW AND ONLY A FEW
CIRRUS IN SIGHT ON SATELLITE IMAGERY...SKIES EXPECTED TO REMAIN
NEARLY CLOUD FREE THIS AFTERNOON. TEMPERATURES FORECAST BY
PREVIOUS SHIFT HAVE BEEN GOOD THROUGH THE MORNING. 925MB TEMPS OF
5 TO 8 C AND NEAR ADIABATIC LAPSE RATES SUGGEST HIGHS TODAY IN THE
UPPER 50S IN THE WEST AND LOWER 50S EAST. SHORT TERM GUIDANCE IS
WARMER THAN THIS BY A COUPLE OF DEGREES. HOWEVER...GIVEN WAA
PATTERN IN SOUTHWEST FLOW...THINK PREVIOUS FORECAST OF LOW 60S IN
THE WEST AND MID-UPPER 50S IN THE EAST WAS ONLY SLIGHTLY
OVERDONE...SO BUMPED TEMPS DOWN A COUPLE OF DEGREES.
&&
.AVIATION/18Z TAFS/...WINDY AFTERNOON IN STORE FOR SOUTHERN
WISCONSIN...AS WINDS CONTINUE TO INCREASE UNDER TIGHT PRESSURE
GRADIENT. SFC WINDS WILL BACK OFF LATE AFTERNOON AND EVENING AS
DAYTIME MIXING IS LOST...OPENING THE DOOR AGAIN FOR WIND SHEAR.
DECIDED TO KEEP THE WIND SHEAR IN THE TAFS THROUGH THE NIGHT AS 45
KT WINDS EXPECTED AT ABOUT 2 KFT. OTHERWISE...MOSTLY CLEAR SKIES
TO CONTINUE INTO SUNDAY MORNING. MID AND HIGH LEVEL CLOUDS WILL
INCREASE TOMORROW AFTERNOON AS LOW PRESSURE DRAWS NEAR...WITH
RAIN AND LOWER CLOUDS MOVING IN DURING THE EVENING HOURS.
&&
.PREV DISCUSSION... /ISSUED 342 AM CST SAT MAR 10 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE HIGH.
STRONG LOW PRESSURE WILL CONTINUE EWD ACROSS CANADA WITH A 50 TO
60KT SWLY LOW LEVEL JET SHIFTING EWD FROM THE UPPER MS RIVER
VALLEY INTO THE GREAT LAKES. STRONG WARM ADVECTION WILL OCCUR WITH
925 MB TEMPS AND FORECAST TRAJECTORIES YIELDING MAX TEMPS AROUND
60F. GUSTY WINDS TO 35 TO 40 MPH WHICH IS UNDER WIND ADVISORY
CRITERIA. PRESSURE GRADIENT TO DECREASE BY TNT BUT STILL ENOUGH OF
A PRESSURE GRADIENT INCLUDING A 40 KT LLJ TO KEEP WINDS GOING AND
THUS RELATIVELY MILD LOW TEMPS. A VERY DRY AIRMASS WILL SUPPORT MO
SUNNY DAY AND A CLEAR NIGHT.
SHORT TERM...SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE
MEDIUM TO HIGH.
SUNDAY APPEARS TO BE A DRY DAY...AS SHORT TERM MODELS SUGGEST ANY
APPRECIABLE UPWARD VERTICAL MOTION WITH APPROACHING UPPER LOW
SHOULD REMAIN SOUTHWEST OF THE AREA. THUS...EXPECT JUST INCREASING
CLOUDS DURING THE DAY SUNDAY. 925MB TEMPERATURES SUPPORT HIGHS IN
THE LOWER 60S AWAY FROM LAKE MICHIGAN...WITH GOOD LOW LEVEL
MIXING. WINDS SHOULD TURN ONSHORE LATE IN THE DAY CLOSE TO
SHORE...KEEPING HIGHS THERE SOMEWHAT COOLER.
UPPER LOW SHIFTS FROM THE CENTRAL PLAINS TO EAST CENTRAL MINNESOTA
SUNDAY NIGHT...THEN OPENS UP AS IS IT SHIFTS NORTHEAST THROUGH
LAKE SUPERIOR MONDAY. AREA FORECAST SOUNDINGS CONTINUE TO SATURATE
DURING THIS TIME...WITH ROBUST UPWARD VERTICAL MOTION. MAY SEE A
LULL IN THE RAIN MONDAY MORNING WITH DRY SLOT...BUT SHOULD SEE
MORE DEVELOPMENT IN THE AFTERNOON WITH INFLUENCE OF PASSING
VORTICITY MAXIMUM.
CONTINUED TO GO WITH HIGH POPS SUNDAY NIGHT INTO MONDAY...TAPERING
OFF AS MONDAY WEARS ON. WEAK HIGH PRESSURE THEN SLIDES INTO THE
REGION MONDAY NIGHT...GRADUALLY ENDING THE RAIN. TEMPERATURES WILL
REMAIN ON THE MILD SIDE DURING THIS TIME.
LONG TERM...TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM
TO HIGH.
WARM AIR ADVECTION KICKS IN AGAIN ACROSS THE REGION TUESDAY INTO
WEDNESDAY...WITH 925MB TEMPERATURES JUMPING INTO THE LOWER TO MID
TEENS CELSIUS RANGE. GOOD LOW LEVEL MIXING AND SOME SUNSHINE
SHOULD ALLOW FOR HIGHS TO JUMP INTO THE 60S AWAY FROM THE LAKE
TUESDAY...THEN INTO THE 70S ACROSS THE AREA WEDNESDAY WITH
SOUTHWEST WINDS.
COLD FRONT THEN SHIFTS SOUTHEAST THROUGH THE AREA LATE WEDNESDAY
AND WEDNESDAY NIGHT. AREA FORECAST SOUNDINGS FROM THE GFS SHOWING
SOME MEAN LAYER CAPES AND MOISTURE DURING THIS TIME...SO CONTINUED
TO MENTION THUNDER IN FORECAST. TEMPERATURES WILL REMAIN MILD
AFTER FRONTAL PASSAGE THROUGH THE REST OF THE WEEK.
AVIATION/12Z TAFS/...A 50-60 KT LLJ WILL DEVELOP OVER THE REGION
TODAY WITH LOW LEVEL WIND SHEAR POSSIBLE OVER SOUTH CENTRAL WI THIS
AM BEFORE WINDS AND MIXING INCREASE THERE. LOW LEVEL WIND SHEAR IS
THEN MARGINAL FOR TNT AS THE PRESSURE GRADIENT DECREASES AND MIXING
CEASES WITH A 40 KT LLJ REMAINING OVER THE AREA. OTHERWISE VFR
CONDITIONS WILL PREVAIL TODAY THROUGH SUNDAY.
MARINE...A GALE WARNING IS IN EFFECT FROM 6 AM UNTIL 6 PM. A STRONG
SWLY 50-60KT LOW LEVEL JET WILL SHIFT FROM THE UPPER MS RIVER VALLEY
INTO THE GREAT LAKES TODAY IN RESPONSE TO STRONG LOW PRESSURE MOVING
EWD ACROSS CANADA. THE PRESSURE GRADIENT AND STRONG LOW LEVEL JET
WILL PRODUCE WINDY CONDITIONS OVER THE LAKE INCLUDING WIND GUSTS TO
GALE FORCE. HIGH WAVES WILL OCCUR ESPECIALLY NORTH OF NORTH POINT
LIGHTHOUSE. THE GUSTY WINDS AND HIGH WAVES WILL LINGER INTO THE
EVENING SO A SMALL CRAFT ADVISORY MAY NEED TO FOLLOW THE CURRENT
GALE WARNING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ051-052-058>060.
LM...GALE WARNING UNTIL 6 PM CST THIS EVENING FOR LMZ643>646.
&&
$$
UPDATE...WIMBERLEY/DDV
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
SUNDAY THROUGH FRIDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
304 AM CST SAT MAR 10 2012
.SHORT TERM...TODAY THROUGH TUESDAY
304 AM CST SAT MAR 10 2012
THE MAIN STORIES IN THE SHORT TERM IS WITH THE WARM...DRY AND
WINDY CONDITIONS TODAY...THE RAIN ON SUNDAY AND MONDAY...AND THEN
HOW WARM IT WILL GET ON TUESDAY.
CURRENTLY...HIGH LEVEL CLOUD COVER IS STREAMING IN FROM THE WEST
AHEAD OF A WEAK DISTURBANCE MOVING ALONG THE US/CANADA BORDER. AT
THE SURFACE...A WARM FRONT EXTENDS SOUTHEASTWARD FROM A LOW NEAR
WINNIPEG THROUGH CENTRAL MINNESOTA AND EASTERN IOWA. WINDS HAVE
GREATLY INCREASED AS A RESULT OF A TIGHTENING PRESSURE GRADIENT
BETWEEN THIS LOW AND A BROAD RIDGE OF HIGH PRESSURE CENTERED OVER
THE GREAT LAKES. WITH THE BETTER MIXING DUE TO THE STRONGER WINDS
TO GO ALONG WITH WARM AIR ADVECTING IN FROM THE WEST IN THE LOW
LEVELS...SURFACE TEMPERATURES HAVE STARTED TO CLIMB ACROSS THE
REGION.
WITH THIS WARMER AIR MASS IN PLACE AND THE SURFACE WARM FRONT WELL
TO THE NORTH TODAY...TEMPERATURES WILL CLIMB TO NEAR RECORD LEVELS
IN THE 60S AS HIGH LEVEL CLOUD COVER BECOMES MORE SPARSE. DETAILS
OF TEMPERATURE RECORDS ARE DISCUSSED IN THE CLIMATE SECTION OF
THIS AFD. THE WINDS ARE THE MAIN CONCERN TODAY WITH WHETHER OR NOT
PORTIONS OF THE REGION WILL HIT ADVISORY CRITERIA. THE 10.00Z
GUIDANCE SUGGESTS THAT THE STRONGEST PRESSURE GRADIENT WILL MOVE
THROUGH THIS MORNING BEFORE WEAKENING IT THIS AFTERNOON. WHILE
THIS TIMING IS NOT IDEAL FOR PEAK DIURNAL HEATING AND MIXING...IT
WILL HELP TO KEEP THE WINDS UP THROUGHOUT THE DAY WITH SUSTAINED
WINDS IN THE 15 TO 25KT RANGE AND GUSTS UP TO 35KTS AT TIMES. MANY
SITES HAVE ALREADY BEEN GUSTING THIS MORNING INTO THE 20 TO 30KT
RANGE AND WOULD JUST EXPECT THESE WINDS TO INCREASE AS WARMING
SURFACE TEMPERATURES DEEPEN THE MIXING. WITH IT BEING BORDERLINE
AT THIS POINT...WILL HOLD OFF ON AN ADVISORY BUT WOULD NOT BE
SURPRISED TO SEE A FEW GUSTS GET CLOSE TO THE 40KT RANGE. THE
OTHER ASPECT OF THIS IS WITH HOW DRY CONDITIONS WILL GET THIS
AFTERNOON WITH THE MIXING. THIS ISSUE IS ADDRESSED IN THE FIRE
WEATHER SECTION OF THIS AFD.
THE FOCUS THEN SHIFTS TO SUNDAY AND MONDAY WITH THE RAIN
CHANCES...MAINLY WITH WHEN IT WILL START AND HOW MUCH WILL FALL.
THE TREND HAS BEEN TO GO LATER WITH THE ONSET OF THE RAIN WHICH
IS MAINLY DUE TO A SLOWER MODEL SOLUTION OF HAVING THE CUT OFF LOW
GET PICKED UP BY THE FLOW A TAD LATER IN THE FOUR CORNERS REGION.
MUCH OF THE 10.00Z GUIDANCE SUGGESTS THAT THE COMBINATION OF
FORCING AND SATURATION DOES NOT OCCUR UNTIL SUNDAY NIGHT AS THE
LOW TAKES AIM AT THE REGION. THUNDER STILL DOES NOT LOOK VERY
LIKELY WITH THE 10.00Z NAM AND GFS SPITTING OUT AROUND 100 J/KG OF
MUCAPE AS A RESULT OF STEEPENING MID LEVEL LAPSE RATES AHEAD OF
THE LOW. THIS SYSTEM WILL MOVE OUT OF THE REGION ON MONDAY WITH
SHOWERS BECOMING MORE AND MORE SCATTERED THROUGH THE DAY.
OVERALL...QPF LOOKS FAIRLY LIGHT AT MAYBE A QUARTER TO A HALF INCH
OF TOTAL RAIN. THIS ISSUE OF ANY SNOW MELT AND RIVER RISES IS
DISCUSSED IN THE HYDRO SECTION OF THE AFD.
BEYOND THIS...A RIDGE OF HIGH PRESSURE WILL MOVE THROUGH THE
REGION MONDAY NIGHT INTO TUESDAY MORNING WITH WARMER LOW LEVEL
GETTING ADVECTED RIGHT BACK INTO THE REGION. DAYTIME TEMPERATURES
WILL CLIMB BACK INTO THE 60S ON TUESDAY WITH WINDS COMING BACK
AROUND TO THE SOUTH.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
304 AM CST SAT MAR 10 2012
THE MAIN HIGHLIGHT IN THE EXTENDED PERIOD IS WITH THE CONTINUED
WARM TEMPERATURES THAT ARE EXPECTED THROUGHOUT THE REST OF THE
WEEK. WEDNESDAY WILL LIKELY BE THE WARMEST DAY OF THE NEXT WEEK AS
SOUTHWESTERLY SURFACE WINDS INCREASE AHEAD OF A COLD FRONT. THESE
SOUTHWESTERLY WINDS WILL LEAD TO HIGH TEMPERATURES CLIMBING INTO
THE 70S DURING THE DAY WEDNESDAY BEFORE THE FRONT COMES THROUGH
THAT EVENING. QUESTIONS STILL LINGER ABOUT WHETHER ANY CONVECTION
WILL INITIATE ALONG THE FRONT WEDNESDAY WITH THE 10.00Z
GFS/GEM/ECMWF KEEPING MUCH OF THE REGION DRY UNTIL THE FRONT GETS
INTO THE GREAT LAKES LATER WEDNESDAY NIGHT. AFTER THE FRONT MOVES
THROUGH...ANOTHER RIDGE OF HIGH PRESSURE COMES THROUGH AHEAD OF A
DEVELOPING SURFACE LOW THAT WILL LIKELY FORM IN THE PLAINS. THIS
MAY LEAD TO SOME ENHANCED LOW LEVEL MOISTURE ADVECTION AND SOME
RAIN SHOWERS GOING INTO NEXT WEEKEND.
&&
.AVIATION...THROUGH 06Z SUNDAY
1134 PM CST FRI MAR 9 2012
WINDS WERE BEGINNING TO PICK UP AT THE TAF SITES...AS THE PRESSURE
GRADIENT STRENGTHENS OVER THE AREA. BOTH 10.03Z RUC AND 10.00Z NAM
BUFKIT SOUNDINGS SHOW AN INCREASE IN THE LOW LEVEL WINDS
OVERNIGHT. IN FACT SUBSEQUENT MODEL RUNS HAVE INCREASED THEM AND
THUS WILL CONTINUE THE LLWS AT BOTH SITES...WITH 50 TO 55 KNOT
WINDS OFF THE DECK. WILL CARRY THIS THROUGH 14Z BEFORE MIXING
TAKES PLACE AND WINDS INCREASE AT THE SURFACE. STILL EXPECTING
SUSTAINED SOUTHWEST WINDS OF 20 TO 30 KNOTS...WITH GUSTS TO 35
KNOTS BETWEEN 14Z-23Z. WINDS SHOULD DIMINISH AFTER
23Z...ESPECIALLY THE GUSTS. OTHERWISE ONLY SOME HIGH CLOUDS WILL
PREVAIL THROUGH THE PERIOD.
&&
.CLIMATE...TODAY
304 AM CST SAT MAR 10 2012
THE COMBINATION OF ABUNDANT SUNSHINE...DRY DEW POINTS...AND
SOUTHWEST WINDS IN THE 15 TO 25 KNOT RANGE WILL ALLOW TEMPERATURES
TO RISE INTO THE MID AND UPPER 50S NORTH OF WISCONSIN 29...AND INTO
THE LOWER AND MID 60S ACROSS THE REMAINDER OF THE FORECAST AREA THIS
AFTERNOON. THESE TEMPERATURES WILL BE WARM ENOUGH FOR THE
POSSIBILITY OF A FEW RECORD HIGH TEMPERATURES TO BE EITHER TIED OR
BROKEN. IN LOCATIONS WHERE THE RECORDS ARE LENGTHY /MORE THAN 115
YEARS/ SUCH AS DECORAH /66F/...LA CROSSE /67F/...MEDFORD /53F/...AND
WINONA /64F/...THE TEMPERATURES THIS AFTERNOON WILL THREATEN THE
1894 RECORDS FOR THIS DATE. MEANWHILE THOSE THIS SHORTER DATA
BASES...THE TEMPERATURES WILL THREATEN RECORDS EITHER SET IN 1967 OR
1977.
&&
.HYDROLOGY...THROUGH MONDAY
304 AM CST SAT MAR 10 2012
SOME MINOR CONCERNS ABOUT WHETHER ANY FLOODING WILL OCCUR ACROSS
NORTH CENTRAL WISCONSIN AS A RESULT OF A MELTING SNOW PACK AND
RAIN SUNDAY NIGHT INTO MONDAY. QPF AMOUNTS ARE LOOKING FAIRLY
LIGHT AT THIS POINT AT JUST A QUARTER OF AN INCH TO A HALF INCH
OVER A LONG PERIOD WITH NO THUNDERSTORMS EXPECTED TO OCCUR. WITH
GRADUAL MELTING DUE TO THE WARMER TEMPERATURES...CURRENTLY EXPECT
TO SEE SOME RIVER RISES ALONG THE BLACK AND TREMPEALEAU
RIVERS...BUT PROBABLY NOT UP TO FLOOD STAGE AT THIS POINT.
&&
.FIRE WEATHER...TODAY
304 AM CST SAT MAR 10 2012
SOME FIRE WEATHER CONCERNS TODAY WITH GUSTY SOUTHWEST WINDS AND
DRY AIR IN PLACE THROUGHOUT THE REGION. THE STRONGEST SURFACE
PRESSURE GRADIENT IS EXPECTED TO MOVE INTO THE AREA THIS MORNING
THOUGH THE BETTER MIXING WILL BE THIS AFTERNOON AS SURFACE
TEMPERATURES CLIMB INTO THE 60S. 10.00Z FORECAST SOUNDINGS ARE
INDICATING MIXING UP TO 2KFT WITH MOMENTUM TRANSFER BRINGING GUSTS
UP INTO THE 35KT RANGE. THIS MIXING WOULD ALSO INDICATE THAT DEW
POINTS WOULD DROP INTO THE TEENS AND LOWER 20S...PARTICULARLY
ACROSS SOUTHEAST MINNESOTA...NORTHEAST IOWA AND WESTERN WISCONSIN.
THIS WOULD LEAD TO RH VALUES OF AROUND 20 PERCENT OR LOWER LATE
THIS MORNING AND AFTERNOON. WITH NO GREEN UP OCCURRING THUS FAR
ACROSS THE REGION...SOME FIRE CONCERNS ARE OUT THERE FOR TODAY.
WINDS SHOULD SUBSIDE QUICKLY THIS EVENING WITH DEW POINTS
REBOUNDING ONCE THE SURFACE TO 2KFT MIXING DECOUPLES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
304 AM CST SAT MAR 10 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RABERDING
CLIMATE...BOYNE
HYDROLOGY...HALBACH
FIRE WEATHER...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1134 PM CST FRI MAR 9 2012
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
332 PM CST FRI MAR 9 2012
MAIN FORECAST CONCERNS WILL BE UNSEASONABLY MILD/BREEZY CONDITIONS
SATURDAY...THEN RAIN CHANCES SUNDAY AFTERNOON THROUGH MONDAY EVENING.
SURFACE MAP THIS AFTERNOON HAS HIGH PRESSURE CENTERED DIRECTLY OVER
THE FORECAST AREA RESULTING IN CLEAR SKIES. FAIRLY CHILLY CONDITIONS
DESPITE FULL SUNSHINE WITH TEMPERATURES AT 2 PM RANGING FROM THE
MIDDLE 20S TO MIDDLE 30S. ON THE BACK SIDE OF THE HIGH AND IN
ADVANCE OF A WARM FRONT PUSHING EAST ACROSS THE DAKOTAS...A FAIRLY
THICK VEIL OF MID/HIGH CLOUD EXISTED ACROSS EASTERN ND INTO CENTRAL
MN...ADVANCING EASTWARD TOWARD THE AREA.
09.12Z NCEP MODELS/ 09.09Z SREF SHOWING VERY GOOD AGREEMENT THROUGH
THE SHORT TERM.
FOR TONIGHT...THE WARM FRONT ACROSS THE DAKOTAS WILL CONTINUE TO
ADVANCE EASTWARD ACROSS THE AREA TONIGHT...EXITING EAST BY DAYBREAK.
AFFECTS OF THE WARM FRONT WILL BE FAIRLY DENSE ALTOCUMULUS FIELD
MAINLY NORTH OF I-90. OTHERWISE...WILL LIKELY SEE A BRIEF/SMALL DOWNWARD
DIP IN TEMPERATURES THROUGH MIDNIGHT...THEN A SLOW RISE THROUGH THE
REMAINDER OF THE NIGHT AS PRESSURE GRADIENT/SOUTHERLY FLOW INTO THE
AREA INCREASES. LOOK FOR LOWS THIS EVENING IN THE LOWER 20S TO
AROUND 30...CLIMBING INTO THE MID 20S TO MIDDLE 30S BY SUNRISE.
SATURDAY LOOKS TO BE A SUNNY/UNSEASONABLY MILD AND BREEZY DAY AS THE
AREA BECOMES ENTRENCHED IN THE WARM SECTOR OF DEEP LOW PRESSURE
MOVING ACROSS ONTARIO CANADA. NAM BUFKIT SOUNDING MIXING TO AROUND
925MB THROUGH SATURDAY WITH TEMPERATURES AT THAT LEVEL WARMING INTO
THE 9-12C RANGE. THIS IS EXPECTED TO YIELD SURFACE TEMPERATURES IN
THE MIDDLE 50S IN THE SNOW PACK AREA ACROSS NORTH CENTRAL
WISCONSIN...TO THE LOWER 60S ACROSS THE REST OF THE AREA. IN
ADDITION...BUFKIT SOUNDINGS ALSO SHOWING STRONG WINDS ALOFT//ABOVE
925MB// OF 50+ KT. LUCKILY WITH A STRONG SUBSIDENCE INVERSION
INDICATED...MIXING SHOULD BE LIMITED TO 925MB WHICH WOULD YIELD WIND
GUST IN FULL MIXING TO 30-40 MPH RANGE.
A RIDGE OF HIGH PRESSURE WILL HOLD OVER THE AREA SATURDAY NIGHT
THROUGH THE MAJORITY OF SUNDAY FOR DRY CONDITIONS. MODEL RH FIELDS
SHOW AN INCREASE IN HIGH/MID CLOUDS THROUGH SUNDAY IN ADVANCE OF A
MID-LEVEL CLOSED LOW OVER THE CENTRAL PLAINS. THE NAM/GFS WANTS TO
BRING SOME -RA INTO NORTHEAST IA/SOUTHEAST MN/FAR SOUTHWEST WI LATE
IN THE AFTERNOON WHILE THE ECMWF/GEM WANT TO MAINTAIN A DRY
FORECAST. CAN SEE SOME VIRGA/FEW RAIN DROPS REACHING THE
SURFACE...SO WILL INCLUDE A SLIGHT CHANCE OF -RA ACROSS THAT AREA
FOR NOW.
GFS/NAM SHOW THE 925-850MB MOISTURE TRANSPORT INCREASING
SIGNIFICANTLY INTO THE AREA SUNDAY NIGHT AS THE MID-LEVEL LOW LIFTS
OUT OF THE CENTRAL PLAINS TOWARD THE UPPER MISSISSIPPI RIVER VALLEY
REGION. NAM/GFS ALSO SHOW PRECIPITABLE WATERS INCREASING TO 250-300
PERCENT ABOVE NORMAL AS GULF MOISTURE TAP GOES UNIMPEDED. THIS WILL
RAPIDLY SATURATE THE COLUMN FOR WIDESPREAD LIGHT-MODERATE RAINFALL.
RAIN APPEARS TO LAST THROUGH MONDAY AS THE LOW LIFTS ACROSS WI INTO
UPPER MICHIGAN. COULD SEE SOME TAPERING OFF IN THE SOUTHWEST
//ACROSS NORTHEAST IA/SOUTHEAST MN// IN THE AFTERNOON AS THE LOW
LIFTS NORTHEAST. THE MID-LEVEL LOW THEN WEAKENS/FILLS AS IT LIFTS
NORTHEAST INTO ONTARIO MONDAY EVENING. THIS SHOULD BRING AN END TO
THE RAIN CHANCES BY 06Z TUESDAY.
.LONG TERM...TUESDAY THROUGH FRIDAY
332 PM CST FRI MAR 9 2012
09.12Z GFS/ECMWF CONTINUE THE UNSEASONABLY MILD WEATHER PATTERN
THROUGH THE PERIOD. GEFS STILL INDICATING AROUND +2 STANDARD
DEVIATIONS WHICH INDICATES NEAR RECORD VALUES FOR HIGH TEMPERATURES
THROUGH THE PERIOD IN THE 60S/LOWER 70S. MAIN CONCERN/FLY IN THE
OINTMENT WILL BE A COLD FRONTAL PASSAGE ON WEDNESDAY AND THE
POTENTIAL FOR THUNDERSTORMS. ECMWF SHOWING NEAR 1500J/KG OF 0-3KM
MUCAPE WEDNESDAY AFTERNOON ALONG WITH RESPECTABLE AMOUNT OF SHEAR.
WILL THEREFORE HAVE TO KEEP A CLOSE EYE ON THIS FOR SEVERE
POTENTIAL. APPEARS BEST THUNDERSTORM CHANCES WILL BE SOUTHEAST OF A
LINE FROM NECEDAH AND VIROQUA WISCONSIN...TO FAYETTE IA.
HOWEVER...DUE TO POSSIBILITY OF A STRONG CAP/TIMING OF FRONT...KEPT
POPS LOW AT THIS TIME.
&&
.AVIATION...THROUGH 06Z SUNDAY
1134 PM CST FRI MAR 9 2012
WINDS WERE BEGINNING TO PICK UP AT THE TAF SITES...AS THE PRESSURE
GRADIENT STRENGTHENS OVER THE AREA. BOTH 10.03Z RUC AND 10.00Z NAM
BUFKIT SOUNDINGS SHOW AN INCREASE IN THE LOW LEVEL WINDS
OVERNIGHT. IN FACT SUBSEQUENT MODEL RUNS HAVE INCREASED THEM AND
THUS WILL CONTINUE THE LLWS AT BOTH SITES...WITH 50 TO 55 KNOT
WINDS OFF THE DECK. WILL CARRY THIS THROUGH 14Z BEFORE MIXING
TAKES PLACE AND WINDS INCREASE AT THE SURFACE. STILL EXPECTING
SUSTAINED SOUTHWEST WINDS OF 20 TO 30 KNOTS...WITH GUSTS TO 35
KNOTS BETWEEN 14Z-23Z. WINDS SHOULD DIMINISH AFTER
23Z...ESPECIALLY THE GUSTS. OTHERWISE ONLY SOME HIGH CLOUDS WILL
PREVAIL THROUGH THE PERIOD.
&&
.HYDROLOGY...
332 PM CST FRI MAR 9 2012
A DEEP SNOW PACK OF 3 TO AS MUCH AS 15 INCHES REMAINS ON THE GROUND
ACROSS TAYLOR COUNTY. ESTIMATED SNOW WATER EQUIVALENTS RANGE FROM A
HALF OF AN INCH UP TO 2 INCHES. THE COMBINATION OF WARM TEMPERATURES
AND EXPECTED RAINFALL AMOUNTS OF UP TO A HALF OF AN INCH FROM SUNDAY
EVENING THROUGH MONDAY...WILL CAUSE RIVERS...STREAMS AND CREEKS TO
RISE THIS WEEKEND INTO NEXT WEEK. THE MAIN RIVER TRIBUTARIES
IMPACTED BY THE RUNOFF FROM THE SNOW MELT AND RAINFALL WILL BE
MAINLY ALONG THE TREMPEALEAU AND BLACK RIVERS. SOME SITES ALONG THE
IMPACTED RIVERS MAY RISE TO FLOOD STAGE...PARTICULARLY IF ANY HEAVY
RAINFALL OCCURS SUNDAY EVENING INTO MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
332 PM CST FRI MAR 9 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...RABERDING
HYDROLOGY...DTJ
AREA FORECAST DISCUSSION
NWS LINCOLN IL
229 AM CDT MON MAR 12 2012
.DISCUSSION...
ISSUED 227 AM CDT MON MAR 12 2012
UPPER LOW CLEARLY EVIDENT IN INFRARED AND WATER VAPOR SATELLITE
IMAGERY...CENTERED OVER EASTERN NEBRASKA. DRY SLOT HAS PUSHED
ACROSS MUCH OF THE CWA...REDUCING THE RAIN TO SCATTERED SHOWERS.
THE EXTENT OF THE LINGERING RAIN IS THE INITIAL FORECAST CONCERN...
BUT THE PRIMARY FOCUS IS THE EXTENDED PERIOD OF ABNORMALLY WARM
WEATHER FOR MID MARCH.
SHORT TERM...TODAY THROUGH WEDNESDAY...
00Z MODELS ARE IN GOOD AGREEMENT WITH TRACKING THE LOW INTO WEST
CENTRAL WISCONSIN BY LATE MORNING...THEN TO THE UPPER PENINSULA OF
MICHIGAN BY EARLY EVENING. LINGERING SHOWERS ACROSS THE EASTERN
CWA SHOULD BE OUT OF THE AREA BY MID TO LATE MORNING. NORTHERN CWA
IS A BIT MORE QUESTIONABLE...AS NAM AND HRRR BOTH SHOWING SOME
INSTABILITY SHOWERS REFORMING IN THE COLDER AIR ALOFT. BOTH MODELS
SHOWING THE BEST RAIN CHANCES IN OUR NORTHERN CWA IN THE MORNING...
BUT WILL LINGER SOME SLIGHT CHANCES THERE INTO THE AFTERNOON AS
WELL.
UPPER RIDGING ACROSS THE CENTRAL U.S. BEGINS IN EARNEST LATER
TONIGHT AND PERSISTS MUCH OF THE WEEK. START OF THE WARMING TREND
BEGINS TODAY AND BY WEDNESDAY...WE WILL LIKELY BE SEEING 80 DEGREE
TEMPERATURES IN SEVERAL LOCATIONS. MOST RECORD HIGHS ON WEDNESDAY
ARE IN THE 74-78 RANGE...WITH SOME LOWER 80S ACROSS THE
SOUTHEAST...SO WILL LIKELY SEE SEVERAL RECORDS FALL. MODELS ARE
SOMEWHAT INCONSISTENT WITH SHOWER/THUNDERSTORM POTENTIAL ON
WEDNESDAY WITH THE RIDGE IN PLACE...BUT RAIN CHANCES INCREASE
WEDNESDAY NIGHT AS A WEAKENING BOUNDARY DROPS INTO THE AREA.
LONG TERM...THURSDAY THROUGH SUNDAY...
850 MB TEMPERATURES REMAIN CLOSE TO +12C THROUGH THE PERIOD...AS
THE UPPER RIDGE GRADUALLY SHIFTS TO THE EAST COAST. HOWEVER...CLOUD
COVER WILL BE MORE OF A FACTOR...AS WEAK WAVES IN THE UPPER FLOW
BRING PERIODIC CHANCES OF SHOWERS AND STORMS. HAVE KEPT HIGHS WELL
INTO THE 70S THROUGH THE PERIOD...BUT HAVE NOT GONE AS AGGRESSIVE
AS WEDNESDAY DUE TO THIS ISSUE.
GEELHART
&&
.AVIATION...
ISSUED 1150 PM CDT SUN MAR 11 2012
CEILINGS HAVE GRADUALLY LOWERED THIS EVENING AS LIGHT RAIN
OVERSPREADS THE AREA. EXPECT THIS TREND TO CONTINUE AS MOISTURE
CONTINUE INCREASES UNDER A 45-55 KT LOW LEVEL JET. SATELLITE LOOPS
SHOW THE DRY SLOT ROTATING AROUND THE NORTHERN KS UPPER LOW AND
COMING ABOUT MIDWAY THROUGH MO/AR. AS THIS CONTINUES EASTWARD INTO
IL...EXPECT RAIN TO BECOME MORE SPOTTY AND WILL LIKELY TRANSITION TO
MORE OF A DRIZZLE SITUATION AS MID/UPPER LEVEL MOISTURE IS PUSHED
OUT. FURTHER BEHIND THE DEEP-LAYER DRY SLOT...SKIES ARE BEGINNING TO
CLEAR OVER SOUTHEAST KS/NORTHEAST OK/SOUTHWESTERN MO. COMBINATION OF
MODEL TIMING AND EXTRAPOLATION USED TO TIME THE CLEARING INTO THE
SOUTHWEST AROUND 11Z...CONTINUING ACROSS THE REMAINDER OF THE TAF
SITES BEFORE 14Z. AFTER THAT...STRATOCU SHOULD INCREASE AGAIN AS
INSOLATION WORKS ON THE REMAINING LOW LEVEL MOISTURE AND DEEP
CYCLONIC FLOW. AFTER A MORNING LULL... WINDS WILL ALSO BE PICKING UP
BY MIDDAY WITH SOUTH-SOUTHWEST WINDS 18-22KT GUSTING ABOVE 30 KT AT
TIMES. SURFACE TROUGH WILL THEN COME THROUGH CENTRAL IL 00Z-04Z AND
CLEAR OUT THE CLOUDS AND BRING DECREASED WESTERLY WINDS.
04
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
423 AM EDT MON MAR 12 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
RAIN WILL MOVE EAST OF THE REGION BY MIDDAY AS AN UPPER LEVEL
DISTURBANCES TRACKS TO NEAR LAKE SUPERIOR. ISOLATED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE THOUGH INTO TONIGHT AS A WEAK
FRONTAL BOUNDARY PASSES THROUGH THE LOWER GREAT LAKES. HIGH PRESSURE
WILL THEN BUILD IN THROUGH MIDWEEK BRINGING DRY AND UNSEASONABLY
WARM WEATHER. CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN BEGINNING
WEDNESDAY NIGHT AND CONTINUING INTO THE WEEKEND AS A FRONTAL
BOUNDARY BECOMES NEARLY STATIONARY ACROSS THE REGION.
&&
.NEAR TERM /TODAY/...
RAIN CURRENTLY EXPANDING ACROSS CENTRAL INDIANA EARLY THIS MORNING.
LOW LEVEL DRY AIR HAS BEEN A SIGNIFICANT IMPEDIMENT TO RAINFALL
COVERAGE AND INTENSITY SO FAR. TEMPS WERE IN THE MID AND UPPER 50S
AS OF 07Z.
HAVE TRENDED TOWARDS THE HRRR WITH RESPECT TO PRECIPITATION TIMING
AND COVERAGE THROUGH MID MORNING AS IT APPEARS TO BE CAPTURING
CURRENT ACTIVITY WELL. AS MENTIONED ABOVE...DRY AIR THROUGH THE
BOUNDARY LAYER HAS REALLY CUT DOWN THE COVERAGE TO RAINFALL FROM
WHAT HAD BEEN PREVIOUSLY THOUGHT. DEWPOINTS AT 07Z REMAIN IN THE 30S
OVER EASTERN COUNTIES WITH QUICK RISES INTO THE 40S AND LOWER 50S
FURTHER WEST AS LOWER LEVELS SATURATE. MOST WIDESPREAD RAINFALL
COVERAGE WILL BE EXPERIENCED THROUGH 12Z WITH STRONGEST ISENTROPIC
LIFT ONGOING AND LOW LEVEL JET TRAVERSING THROUGH THE AREA. WILL
MAINTAIN CATEGORICAL POPS THROUGH DAYBREAK...BUT OVERALL QPF VALUES
WILL BE UNDER 0.25 INCHES. WILL MAINTAIN AN ISOLATED THUNDER MENTION
AS WELL BASED ON SUBTLE LEVELS OF INSTABILITY AND SAID FORCING ALOFT
PRESENT.
MUCH OF THE RAIN WILL SHIFT EAST OF THE FORECAST AREA THROUGH MID
MORNING AS DRIER PUNCH OF AIR SURGES INTO THE REGION FROM THE
SOUTHWEST. WILL HOLD ONTO HIGHEST POPS OVER EASTERN COUNTIES THROUGH
ABOUT 15Z DIMINISHING TO CHANCE OR LOWER THEREAFTER. AS DRIER AIR
PRESSES INTO CENTRAL INDIANA...MODEL SOUNDINGS INDICATE LOW LEVEL
MOISTURE WILL BECOME TRAPPED UNDERNEATH A BOUNDARY LAYER INVERSION.
THIS WOULD SUGGEST STRATOCU LIKELY TO BE SLOW TO DEPART TODAY...
WITH ANY SUNSHINE HOLDING OFF UNTIL THE AFTERNOON AS THE LOWER
LEVELS BEGIN MIXING OUT. ARRIVAL OF A SECOND LOW LEVEL JET THIS
AFTERNOON COMBINED WITH STRATOCU MIXING OUT WILL SET THE STAGE FOR
GUSTY WINDS POSSIBLY TO 30 TO 35 MPH DURING THE AFTERNOON. HAVE HELD
ONTO LOW CHANCE POPS OVER EASTERN COUNTIES THIS AFTERNOON WITH WEAK
INSTABILITY AND LINGERING LOW LEVEL MOISTURE PRESENT. LACK OF
APPRECIABLE FORCING ALOFT HOWEVER SHOULD KEEP ANY CONVECTION THAT
DEVELOPS ISOLATED AT BEST.
TEMPS...LOW LEVEL THERMALS WILL CLIMB FURTHER TODAY WITH THE STRONG
SOUTHWEST FLOW INTO THE OHIO VALLEY. DESPITE THE PRESENCE OF CLOUDS
INTO THE AFTERNOON...MANY LOCATIONS LIKELY TO MAKE IT TO THE 70
DEGREE MARK FOR THE FIRST TIME THIS YEAR. TRENDED A DEGREE OR TWO
ABOVE GUIDANCE IN MOST AREAS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON TEMPS AS SPRING PREVIEW ARRIVES TO
CENTRAL INDIANA THIS WEEK.
UPPER LOW WILL TRACK THROUGH THE NORTHERN GREAT LAKES TONIGHT WITH A
WEAK SURFACE BOUNDARY PASSING THROUGH THE LOWER GREAT LAKES
OVERNIGHT. EXPECTED CONVECTIVE DEVELOPMENT ACROSS MICHIGAN AND
NORTHERN INDIANA WHERE FORCING ALOFT AND AVAILABLE INSTABILITY WILL
BE GREATER MAY CLIP FAR NORTHERN COUNTIES AND HAVE HELD ONTO
ISOLATED POPS IN THESE AREAS. HOWEVER WITH SHALLOW MOISTURE PROFILES
NOTED ON MODEL SOUNDINGS...BOUNDARY MORE LIKELY TO PASS THROUGH THE
FORECAST AREA UNEVENTFULLY.
SURFACE HIGH PRESSURE EXPANDS INTO THE REGION TUESDAY WITH RIDGING
ALOFT. ANY LINGERING LOWER CLOUDS TUESDAY MORNING WILL DIMINISH AS
INCREASING SUBSIDENCE ABOVE THE BOUNDARY LAYER EXPANDS ACROSS THE
OHIO VALLEY. AS THE HIGH DRIFTS EAST BY WEDNESDAY NIGHT...DEVELOPING
S/SW FLOW THROUGH THE LOW LEVELS WILL BRING INCREASINGLY MOIST AIR
NORTH OUT OF THE GULF OF MEXICO. DESPITE LITTLE IF ANY FORCING ALOFT
WEDNESDAY NIGHT...ISOLATED TO SCATTERED CONVECTIVE DEVELOPMENT IS
EXPECTED AS THE INCREASING MOISTURE AND INSTABILITY INTERACT WITH AN
APPROACHING WEAK FRONTAL BOUNDARY. WILL CARRY 30 POPS OVERNIGHT
WEDNESDAY.
TEMPS...UNSEASONABLY WARM TEMPERATURES THROUGH THE PERIOD AS LOW
LEVEL THERMALS CONTINUE TO RISE WITH 850MB TEMPS APPROACHING 13C AND
15-16C AT 925MB BY WEDNESDAY. HAVE GONE AT OR ABOVE MAVMOS GUIDANCE
BOTH TUESDAY AND WEDNESDAY WITH 70S EXPECTED. HIGH TEMPERATURES MAY
APPROACH NEAR RECORD HIGHS ON WEDNESDAY AND NOT OUT OF THE QUESTION
AT THIS POINT THAT WESTERN COUNTIES FLIRT WITH 80 DEGREES. MOS
GUIDANCE LOOKED REASONABLE FOR LOWS THROUGH THE PERIOD. JUST THE
BEGINNING OF WHAT APPEARS TO BE AN EXTENDED PERIOD OF WELL ABOVE
NORMAL TEMPS FOR CENTRAL INDIANA.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ENSEMBLES SUGGEST UPPER PATTERN WILL BECOME HIGHLY AMPLIFIED
DURING THIS PERIOD. STRONG RIDGING IS EXPECTED TO DEVELOP OVER THE
EASTERN PARTS OF THE COUNTRY...WHILE A DEEP TROUGH WILL DEVELOP OVER
THE WEST COAST. ENSEMBLES SUGGEST AN UPPER DISTURBANCE MAY BE MOVING
THROUGH THE NORTHERN GREAT LAKES AROUND THURSDAY. TOWARDS NEXT
WEEKEND...IT APPEARS THAT A BROAD SOUTHWESTERLY UPPER FLOW WILL
DEVELOP OVER THE LOCAL AREA AHEAD OF WESTERN TROUGH. THIS WILL
RESULT IN THE POSSIBILITY OF EMBEDDED DISTURBANCES EJECTING OUT OF
THE TROUGH...WITH ENSEMBLES SUGGESTING A PRECIPITATION THREAT PRETTY
MUCH ALL THROUGH THE EXTENDED PERIOD. WILL KEEP POPS GOING FROM
THURSDAY THROUGH SATURDAY. INHERITED A DRY FORECAST FOR NEXT
SUNDAY...BUT SOME OF ENSEMBLE MEMBERS AND OPERATIONAL MODELS SUGGEST
AN UNSTABLE AIR MASS AND RESULTANT PRECIPITATION THREAT AT THAT TIME.
WILL CONTINUE TO KEEP SUNDAY DRY FOR NOW...BUT POPS MAY NEED TO BE
ADDED AT A LATER TIME IF TRENDS LEAN TOWARDS A WETTER SOLUTION.
&&
.AVIATION /DISCUSSION FOR THE 120900Z KIND TAF UPDATE/...
BASED ON RADAR TRENDS...PRECIPITATION EXPECTED TO BECOME MORE
INTERMITTENT IN NATURE IN THE VICINITY OF KIND THROUGH THE MID
MORNING HOURS. LOWER CEILINGS AROUND 015 HAVE BEEN SLOW TO
MATERIALIZE SO FAR...BUT ARE BEGINNING TO SHOW UP OVER EASTERN
ILLINOIS AND FAR WESTERN INDIANA. WILL BACK OFF ON THE ARRIVAL OF
THESE LOWER CEILINGS TO AROUND SUNRISE. COULD BE SOME SURFACE WIND
GUSTS 20-22KTS FROM 160-180 HEADINGS DEVELOPING OVER THE NEXT COUPLE
OF HOURS BASED ON OBSERVATIONS UPSTREAM. PREVIOUS DISCUSSION
FOLLOWS.
VFR...BECOMING MVFR EARLY THIS MORNING AND THEN BACK TO VFR BY
EARLY AFTERNOON.
CEILINGS AND VISIBILITIES WILL BEGIN LOWER TO MVFR AFTER 06Z AS A
FRONTAL BOUNDARY APPROACHES THE REGION AND THEN LIFTS NORTH OVER THE
STATE EARLY TODAY. NUMEROUS SHOWERS (NOTED UPSTREAM) WILL OCCUR WITH
THIS FEATURE. AN ISOLATED THUNDER SHOWER IS ALSO POSSIBLE (MOSTLY
ELEVATED CONVECTION)...THROUGH EARLY THIS MORNING. HOWEVER CHANCES
REMAIN TOO LOW TO MENTION. DRIER AIR BEHIND FRONT WILL BEGIN TO WORK
IN TO OUR REGION AFTER MID MORNING AND CEILINGS AND VISIBILITIES
WILL IMPROVE AFTER THAT. (AROUND 16-18Z). MID MORNING WINDS WILL
INCREASE AND BE SOUTH TO SOUTHWEST AROUND 15 KNOTS WITH GUSTS TO
25 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...SMF/JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
331 AM EDT MON MAR 12 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...
RAIN WILL MOVE EAST OF THE REGION BY MIDDAY AS AN UPPER LEVEL
DISTURBANCES TRACKS TO NEAR LAKE SUPERIOR. ISOLATED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE THOUGH INTO TONIGHT AS A WEAK
FRONTAL BOUNDARY PASSES THROUGH THE LOWER GREAT LAKES. HIGH PRESSURE
WILL THEN BUILD IN THROUGH MIDWEEK BRINGING DRY AND UNSEASONABLY
WARM WEATHER. CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN BEGINNING
WEDNESDAY NIGHT AND CONTINUING INTO THE WEEKEND AS A FRONTAL
BOUNDARY BECOMES NEARLY STATIONARY ACROSS THE REGION.
&&
.NEAR TERM /TODAY/...
RAIN CURRENTLY EXPANDING ACROSS CENTRAL INDIANA EARLY THIS MORNING.
LOW LEVEL DRY AIR HAS BEEN A SIGNIFICANT IMPEDIMENT TO RAINFALL
COVERAGE AND INTENSITY SO FAR. TEMPS WERE IN THE MID AND UPPER 50S
AS OF 07Z.
HAVE TRENDED TOWARDS THE HRRR WITH RESPECT TO PRECIPITATION TIMING
AND COVERAGE THROUGH MID MORNING AS IT APPEARS TO BE CAPTURING
CURRENT ACTIVITY WELL. AS MENTIONED ABOVE...DRY AIR THROUGH THE
BOUNDARY LAYER HAS REALLY CUT DOWN THE COVERAGE TO RAINFALL FROM
WHAT HAD BEEN PREVIOUSLY THOUGHT. DEWPOINTS AT 07Z REMAIN IN THE 30S
OVER EASTERN COUNTIES WITH QUICK RISES INTO THE 40S AND LOWER 50S
FURTHER WEST AS LOWER LEVELS SATURATE. MOST WIDESPREAD RAINFALL
COVERAGE WILL BE EXPERIENCED THROUGH 12Z WITH STRONGEST ISENTROPIC
LIFT ONGOING AND LOW LEVEL JET TRAVERSING THROUGH THE AREA. WILL
MAINTAIN CATEGORICAL POPS THROUGH DAYBREAK...BUT OVERALL QPF VALUES
WILL BE UNDER 0.25 INCHES. WILL MAINTAIN AN ISOLATED THUNDER MENTION
AS WELL BASED ON SUBTLE LEVELS OF INSTABILITY AND SAID FORCING ALOFT
PRESENT.
MUCH OF THE RAIN WILL SHIFT EAST OF THE FORECAST AREA THROUGH MID
MORNING AS DRIER PUNCH OF AIR SURGES INTO THE REGION FROM THE
SOUTHWEST. WILL HOLD ONTO HIGHEST POPS OVER EASTERN COUNTIES THROUGH
ABOUT 15Z DIMINISHING TO CHANCE OR LOWER THEREAFTER. AS DRIER AIR
PRESSES INTO CENTRAL INDIANA...MODEL SOUNDINGS INDICATE LOW LEVEL
MOISTURE WILL BECOME TRAPPED UNDERNEATH A BOUNDARY LAYER INVERSION.
THIS WOULD SUGGEST STRATOCU LIKELY TO BE SLOW TO DEPART TODAY...
WITH ANY SUNSHINE HOLDING OFF UNTIL THE AFTERNOON AS THE LOWER
LEVELS BEGIN MIXING OUT. ARRIVAL OF A SECOND LOW LEVEL JET THIS
AFTERNOON COMBINED WITH STRATOCU MIXING OUT WILL SET THE STAGE FOR
GUSTY WINDS POSSIBLY TO 30 TO 35 MPH DURING THE AFTERNOON. HAVE HELD
ONTO LOW CHANCE POPS OVER EASTERN COUNTIES THIS AFTERNOON WITH WEAK
INSTABILITY AND LINGERING LOW LEVEL MOISTURE PRESENT. LACK OF
APPRECIABLE FORCING ALOFT HOWEVER SHOULD KEEP ANY CONVECTION THAT
DEVELOPS ISOLATED AT BEST.
TEMPS...LOW LEVEL THERMALS WILL CLIMB FURTHER TODAY WITH THE STRONG
SOUTHWEST FLOW INTO THE OHIO VALLEY. DESPITE THE PRESENCE OF CLOUDS
INTO THE AFTERNOON...MANY LOCATIONS LIKELY TO MAKE IT TO THE 70
DEGREE MARK FOR THE FIRST TIME THIS YEAR. TRENDED A DEGREE OR TWO
ABOVE GUIDANCE IN MOST AREAS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON TEMPS AS SPRING PREVIEW ARRIVES TO
CENTRAL INDIANA THIS WEEK.
UPPER LOW WILL TRACK THROUGH THE NORTHERN GREAT LAKES TONIGHT WITH A
WEAK SURFACE BOUNDARY PASSING THROUGH THE LOWER GREAT LAKES
OVERNIGHT. EXPECTED CONVECTIVE DEVELOPMENT ACROSS MICHIGAN AND
NORTHERN INDIANA WHERE FORCING ALOFT AND AVAILABLE INSTABILITY WILL
BE GREATER MAY CLIP FAR NORTHERN COUNTIES AND HAVE HELD ONTO
ISOLATED POPS IN THESE AREAS. HOWEVER WITH SHALLOW MOISTURE PROFILES
NOTED ON MODEL SOUNDINGS...BOUNDARY MORE LIKELY TO PASS THROUGH THE
FORECAST AREA UNEVENTFULLY.
SURFACE HIGH PRESSURE EXPANDS INTO THE REGION TUESDAY WITH RIDGING
ALOFT. ANY LINGERING LOWER CLOUDS TUESDAY MORNING WILL DIMINISH AS
INCREASING SUBSIDENCE ABOVE THE BOUNDARY LAYER EXPANDS ACROSS THE
OHIO VALLEY. AS THE HIGH DRIFTS EAST BY WEDNESDAY NIGHT...DEVELOPING
S/SW FLOW THROUGH THE LOW LEVELS WILL BRING INCREASINGLY MOIST AIR
NORTH OUT OF THE GULF OF MEXICO. DESPITE LITTLE IF ANY FORCING ALOFT
WEDNESDAY NIGHT...ISOLATED TO SCATTERED CONVECTIVE DEVELOPMENT IS
EXPECTED AS THE INCREASING MOISTURE AND INSTABILITY INTERACT WITH AN
APPROACHING WEAK FRONTAL BOUNDARY. WILL CARRY 30 POPS OVERNIGHT
WEDNESDAY.
TEMPS...UNSEASONABLY WARM TEMPERATURES THROUGH THE PERIOD AS LOW
LEVEL THERMALS CONTINUE TO RISE WITH 850MB TEMPS APPROACHING 13C AND
15-16C AT 925MB BY WEDNESDAY. HAVE GONE AT OR ABOVE MAVMOS GUIDANCE
BOTH TUESDAY AND WEDNESDAY WITH 70S EXPECTED. HIGH TEMPERATURES MAY
APPROACH NEAR RECORD HIGHS ON WEDNESDAY AND NOT OUT OF THE QUESTION
AT THIS POINT THAT WESTERN COUNTIES FLIRT WITH 80 DEGREES. MOS
GUIDANCE LOOKED REASONABLE FOR LOWS THROUGH THE PERIOD. JUST THE
BEGINNING OF WHAT APPEARS TO BE AN EXTENDED PERIOD OF WELL ABOVE
NORMAL TEMPS FOR CENTRAL INDIANA.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ENSEMBLES SUGGEST UPPER PATTERN WILL BECOME HIGHLY AMPLIFIED
DURING THIS PERIOD. STRONG RIDGING IS EXPECTED TO DEVELOP OVER THE
EASTERN PARTS OF THE COUNTRY...WHILE A DEEP TROUGH WILL DEVELOP OVER
THE WEST COAST. ENSEMBLES SUGGEST AN UPPER DISTURBANCE MAY BE MOVING
THROUGH THE NORTHERN GREAT LAKES AROUND THURSDAY. TOWARDS NEXT
WEEKEND...IT APPEARS THAT A BROAD SOUTHWESTERLY UPPER FLOW WILL
DEVELOP OVER THE LOCAL AREA AHEAD OF WESTERN TROUGH. THIS WILL
RESULT IN THE POSSIBILITY OF EMBEDDED DISTURBANCES EJECTING OUT OF
THE TROUGH...WITH ENSEMBLES SUGGESTING A PRECIPITATION THREAT PRETTY
MUCH ALL THROUGH THE EXTENDED PERIOD. WILL KEEP POPS GOING FROM
THURSDAY THROUGH SATURDAY. INHERITED A DRY FORECAST FOR NEXT
SUNDAY...BUT SOME OF ENSEMBLE MEMBERS AND OPERATIONAL MODELS SUGGEST
AN UNSTABLE AIR MASS AND RESULTANT PRECIPITATION THREAT AT THAT TIME.
WILL CONTINUE TO KEEP SUNDAY DRY FOR NOW...BUT POPS MAY NEED TO BE
ADDED AT A LATER TIME IF TRENDS LEAN TOWARDS A WETTER SOLUTION.
&&
.AVIATION /DISCUSSION FOR THE 120600Z TAFS/...
VFR...BECOMING MVFR EARLY THIS MORNING AND THEN BACK TO VFR BY
EARLY AFTERNOON.
CEILINGS AND VISIBILITIES WILL BEGIN LOWER TO MVFR AFTER 06Z AS A
FRONTAL BOUNDARY APPROACHES THE REGION AND THEN LIFTS NORTH OVER THE
STATE EARLY TODAY. NUMEROUS SHOWERS (NOTED UPSTREAM) WILL OCCUR WITH
THIS FEATURE. AN ISOLATED THUNDER SHOWER IS ALSO POSSIBLE (MOSTLY
ELEVATED CONVECTION)...THROUGH EARLY THIS MORNING. HOWEVER CHANCES
REMAIN TOO LOW TO MENTION. DRIER AIR BEHIND FRONT WILL BEGIN TO WORK
IN TO OUR REGION AFTER MID MORNING AND CEILINGS AND VISIBILITIES
WILL IMPROVE AFTER THAT. (AROUND 16-18Z). MID MORNING WINDS WILL
INCREASE AND BE SOUTH TO SOUTHWEST AROUND 15 KNOTS WITH GUSTS TO
25 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...SMF/JAS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
410 AM CDT MON MAR 12 2012
...UPDATED FOR FIRE WEATHER DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM CDT MON MAR 12 2012
UPPER-LEVEL TROUGHING WILL PERSIST THROUGH MARCH 18TH ACROSS THE FAR
WESTERN UNITED STATES, THEN SLOWLY PROGRESS EASTWARD AND AMPLIFY
JUST TO OUR WEST BY MARCH 19-20TH. GIVEN THE EXPECTED POSITIONING OF
THIS TROUGH OVER THE FAR WESTERN UNITED STATES BY MID-WEEK,
SOUTHWESTERLY MID-LEVEL FLOW WILL BE PRESENT ACROSS THE ROCKIES AND
OVER THE PLAINS. LEE TROUGHING WILL DEVELOP IN RESPONSE TO THE FLOW
ACROSS THE ROCKIES, AND THIS WILL SERVE TO DRAW RICH LOW-LEVEL
MOISTURE NORTHWARD INTO THE SOUTHERN PLAINS. THE SURFACE DRYLINE
WILL MARK THE INTERFACE BETWEEN THE MOIST AIRMASS OVER THE PLAINS
AND THE DRY AIRMASS OVER THE WESTERN HIGH PLAINS AND ROCKIES. IT
WILL BE WARM EVERY DAY THROUGH THE WEEKEND WITH HIGHS IN THE 70S AND
80S AND LOWS FROM THE UPPER 40S WEST TO 55 TO 62 IN SOUTH CENTRAL
KANSAS. OFTENTIMES IN RETURN FLOW SITUATIONS IN MARCH, PREVIOUS COLD
FRONTAL PASSAGES THROUGH THE GULF AND EVEN INTO THE CARIBBEAN RESULT
IN ONLY MODEST MOISTURE RETURNS INTO THE PLAINS. THIS WILL NOT BE
THE CASE THIS WEEK SINCE THE GULF SEA SURFACE IS NEARLY AT
EQUILIBRIUM WITH THE AIR IMMEDIATELY ABOVE. GULF BUOY DATA INDICATE
DEWPOINTS AROUND 70F IN THE CENTRAL GULF CURRENTLY, WHICH IS VERY
IMPRESSIVE FOR THIS TIME OF YEAR. KEEP IN MIND THAT JUST BECAUSE 70F
DEWPOINTS ARE PRESENT IN THE CENTRAL GULF DOESN`T MEAN THAT WE CAN
EXPECT DEWPOINTS THAT HIGH IN SOUTHWEST KANSAS LATER THIS WEEK.
WHEN MOIST, MARINE AIR MOVES NORTHWARD INTO THE PLAINS, DEEP
VERTICAL MIXING OCCURS, WHICH CAUSES THE MOIST LAYER TO BE DEEPER,
BUT NOT QUITE AS RICH. ALSO, DODGE CITY IS 2600FT ABOVE SEA LEVEL
AND THIS INCREASED ELEVATION WILL RESULT IN SOME REDUCTION IN
DEWPOINT AS WELL AS THE MOISTURE MOVES ONTO THE HIGHER TERRAIN. SO
IT IS MORE REASONABLE TO EXPECT DEWPOINT TEMPERATURES FROM THE MID
50S TO THE MID 60S (13-18C) AHEAD OF THE DRYLINE.
BY WEDNESDAY AFTERNOON, THE SURFACE DRYLINE WILL STRETCH FROM A
WEAK SURFACE LOW AND FRONT OVER SOUTHWEST KANSAS SOUTH-SOUTHWESTWARD
INTO THE TEXAS PANHANDLE. A SUBTROPICAL JET STREAK WILL BE SITUATED
ACROSS THE TEXAS PANHANDLE. SURFACE BASED CAPE VALUES WILL APPROACH
2000 J/KG BY LATE AFTERNOON FROM DODGE CITY SOUTH AND EAST. THERE
MAY BE ENOUGH CONVERGENCE ALONG THE DRYLINE AND NEAR THE FRONT-
DRYLINE INTERSECTION, ALONG WITH STRONG ELEVATED HEATING, TO YIELD
ISOLATED THUNDERSTORMS. ANY STORMS THAT DEVELOP COULD BE SEVERE WITH
LARGE HAIL.
ISOLATED THUNDERSTORMS CANNOT BE RULED ANY DAY THROUGH MARCH 20TH AS THE
SURFACE DRYLINE REMAINS OVER WESTERN KANSAS. THE ECMWF INDICATES
THAT THE BEST CHANCES MAY BE SATURDAY FROM DODGE CITY SOUTHEASTWARD,
AND THEN AGAIN BY MONDAY AND TUESDAY AS THE UPPER-LEVEL TROUGH AND
ASSOCIATED MID-LEVEL COOLING APPROACH WESTERN KANSAS. ANY STORMS
THAT DEVELOP IN THESE PERIODS COULD BE SEVERE, ALTHOUGH THE BEST
CHANCE OF HIGH-END SEVERE STORMS WITH TORNADOES SHOULD BE LATER
MONDAY OR TUESDAY AS THE MID TO HIGH-LEVEL WINDS BECOME MUCH
STRONGER IN ADVANCE OF THE UPPER-LEVEL TROUGH. OF COURSE, A LOT
COULD CHANGE BETWEEN NOW AND MARCH 19TH-20TH; AND IT IS IMPOSSIBLE
TO SAY AT THIS POINT EXACTLY WHERE IN THE PLAINS THE BEST CHANCE
OF THUNDERSTORMS WILL BE.
KEEP IN MIND THAT DUE TO THE VERY WARM EXPECTED TEMPERATURES, RECORD
HIGH NIGHTTIME AND DAYTIME TEMPERATURES ARE POSSIBLE ACROSS WESTERN
KANSAS LATER THIS WEEK AND THIS WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1230 AM CDT MON MAR 12 2012
SOME EARLY MORNING MIST COULD REDUCE VISIBILITIES DOWN TO 5-6 MILES
AT DODGE CITY AND HAYS AT THE BEGINNING OF THIS TAF PERIOD BUT VFR
CONDITIONS SHOULD QUICKLY RETURN AND PREVAIL THROUGH THE REMAINDER OF
THE PERIOD. SOUTHERLY WINDS WILL SWITCH AROUND TO THE WEST BY 12Z AND
INCREASE INTO THE 10 TO 15 KNOT RANGE DURING THE MORNING HOURS.
&&
.FIRE WEATHER...
ISSUED AT 402 AM CDT MON MAR 12 2012
FIRE WEATHER WILL BE A CONCERN ON TUESDAY. AFTERNOON VERTICAL
MIXING WILL RESULT IN RELATIVE HUMIDITIES FROM 10 TO 15 PERCENT
ALONG WITH FREQUENT WIND GUSTS NEAR OR JUST IN EXCESS OF 25 MPH.
A FIRE WEATHER WATCH IS IN EFFECT ALONG AND WEST OF A LINE FROM
MEADE TO DIGHTON. THIS WAS NOT UPGRADED SINCE THERE IS SOME
QUESTION AS TO WHETHER SURFACE WINDS WILL BE STRONG ENOUGH. ALSO
ELLIS AND TREGO COUNTIES MAY NEED TO BE ADDED.
AFTER A LESSENING OF THE PRESSURE GRADIENT WEDNESDAY AND THURSDAY,
FIRE WEATHER WILL BE A CONCERN EVERY DAY FROM FRIDAY THROUGH SUNDAY,
ESPECIALLY IN FAR WESTERN KANSAS BEHIND THE SURFACE DRYLINE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 77 41 83 46 / 0 0 0 0
GCK 76 39 82 42 / 0 0 0 0
EHA 75 38 82 41 / 0 0 0 0
LBL 76 39 81 42 / 0 0 0 0
HYS 78 42 82 46 / 0 0 0 0
P28 78 44 81 53 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ065-066-
079>081-089-090.
&&
$$
UPDATE...BURKE
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
400 AM CDT MON MAR 12 2012
...UPDATED FOR LONG TERM DISCUSSION...
.UPDATE...
ISSUED AT 821 PM CDT SUN MAR 11 2012
THE UPPER LEVEL LOW WAS PULLING OUT FASTER THAN PREVIOUSLY
THOUGHT, AS WAS THE LOW LEVEL PRESSURE SYSTEM. A FEW SHOWERS MAY
MOVE THROUGH THE NORTHEASTERN SIDE OF OUR CWA IN THE WRAPAROUND,
BUT THESE SHOULD BE FAR AND FEW BETWEEN, AND VERY LIGHT IN
PRECIPITATION AMOUNTS. WILL ONLY LEAVE PRECIP CHANCES IN THE
NORTHEAST FOR A FEW HOURS, THEN DIMINISH THEM ALL TOGETHER. I
REDUCED QPF TO .01-INCH. THE REST OF FORECAST WILL REMAIN THE
SAME.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM CDT MON MAR 12 2012
UPPER-LEVEL TROUGHING WILL PERSIST THROUGH MARCH 18TH ACROSS THE FAR
WESTERN UNITED STATES, THEN SLOWLY PROGRESS EASTWARD AND AMPLIFY
JUST TO OUR WEST BY MARCH 19-20TH. GIVEN THE EXPECTED POSITIONING OF
THIS TROUGH OVER THE FAR WESTERN UNITED STATES BY MID-WEEK,
SOUTHWESTERLY MID-LEVEL FLOW WILL BE PRESENT ACROSS THE ROCKIES AND
OVER THE PLAINS. LEE TROUGHING WILL DEVELOP IN RESPONSE TO THE FLOW
ACROSS THE ROCKIES, AND THIS WILL SERVE TO DRAW RICH LOW-LEVEL
MOISTURE NORTHWARD INTO THE SOUTHERN PLAINS. THE SURFACE DRYLINE
WILL MARK THE INTERFACE BETWEEN THE MOIST AIRMASS OVER THE PLAINS
AND THE DRY AIRMASS OVER THE WESTERN HIGH PLAINS AND ROCKIES. IT
WILL BE WARM EVERY DAY THROUGH THE WEEKEND WITH HIGHS IN THE 70S AND
80S AND LOWS FROM THE UPPER 40S WEST TO 55 TO 62 IN SOUTH CENTRAL
KANSAS. OFTENTIMES IN RETURN FLOW SITUATIONS IN MARCH, PREVIOUS COLD
FRONTAL PASSAGES THROUGH THE GULF AND EVEN INTO THE CARIBBEAN RESULT
IN ONLY MODEST MOISTURE RETURNS INTO THE PLAINS. THIS WILL NOT BE
THE CASE THIS WEEK SINCE THE GULF SEA SURFACE IS NEARLY AT
EQUILIBRIUM WITH THE AIR IMMEDIATELY ABOVE. GULF BUOY DATA INDICATE
DEWPOINTS AROUND 70F IN THE CENTRAL GULF CURRENTLY, WHICH IS VERY
IMPRESSIVE FOR THIS TIME OF YEAR. KEEP IN MIND THAT JUST BECAUSE 70F
DEWPOINTS ARE PRESENT IN THE CENTRAL GULF DOESN`T THEN THAT WE
CAN EXPECT DEWPOINTS THAT HIGH IN SOUTHWEST KANSAS LATER THIS WEEK.
WHEN MOIST, MARINE AIR MOVES NORTHWARD INTO THE PLAINS, DEEP VERTICAL
MIXING OCCURS, WHICH CAUSES THE MOIST LAYER TO BE DEEPER, BUT NOT
QUITE AS RICH. ALSO, DODGE CITY IS 2600FT ABOVE SEA LEVEL AND THIS
INCREASED ELEVATION WILL RESULT IN SOME REDUCTION IN DEWPOINT AS
WELL AS THE MOISTURE MOVES ONTO THE HIGHER TERRAIN. SO IT IS MORE
REASONABLE TO EXPECT DEWPOINT TEMPERATURES FROM THE MID 50S TO THE
MID 60S (13-18C) AHEAD OF THE DRYLINE.
BY WEDNESDAY AFTERNOON, THE SURFACE DRYLINE WILL STRETCH FROM A
WEAK SURFACE LOW AND FRONT OVER SOUTHWEST KANSAS SOUTH-SOUTHWESTWARD
INTO THE TEXAS PANHANDLE. A SUBTROPICAL JET STREAK WILL BE SITUATED
ACROSS THE TEXAS PANHANDLE. SURFACE BASED CAPE VALUES WILL APPROACH
2000 J/KG BY LATE AFTERNOON FROM DODGE CITY SOUTH AND EAST. THERE
MAY BE ENOUGH CONVERGENCE ALONG THE DRYLINE AND NEAR THE FRONT-
DRYLINE INTERSECTION, ALONG WITH STRONG ELEVATED HEATING, TO YIELD
ISOLATED THUNDERSTORMS. ANY STORMS THAT DEVELOP COULD BE SEVERE WITH
LARGE HAIL.
ISOLATED THUNDERSTORMS CANNOT BE RULED ANY DAY THROUGH MARCH 20TH AS THE
SURFACE DRYLINE REMAINS OVER WESTERN KANSAS. THE ECMWF INDICATES
THAT THE BEST CHANCES MAY BE SATURDAY FROM DODGE CITY SOUTHEASTWARD,
AND THEN AGAIN BY MONDAY AND TUESDAY AS THE UPPER-LEVEL TROUGH AND
ASSOCIATED MID-LEVEL COOLING APPROACHE WESTERN KANSAS. ANY STORMS
THAT DEVELOP IN THESE PERIODS COULD BE SEVERE, ALTHOUGH THE BEST
CHANCE OF HIGH-END SEVERE STORMS WITH TORNADOES SHOULD BE LATER
MONDAY OR TUESDAY AS THE MID TO HIGH-LEVEL WINDS BECOME MUCH
STRONGER IN ADVANCE OF THE UPPER-LEVEL TROUGH. OF COURSE, A LOT
COULD CHANGE BETWEEN NOW AND MARCH 19TH-20TH, AND IT IS IMPOSSIBLE
TO SAY AT THIS POINT EXACTLY WHERE IN THE PLAINS THE BEST CHANCE OF
THUNDERSTORMS WILL BE.
KEEP IN MIND THAT DUE TO THE VERY WARM EXPECTED TEMPERATURES, RECORD
HIGH NIGHTTIME AND DAYTIME TEMPERATURES ARE POSSIBLE ACROSS WESTERN
KANSAS LATER THIS WEEK AND THIS WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1230 AM CDT MON MAR 12 2012
SOME EARLY MORNING MIST COULD REDUCE VISIBILITIES DOWN TO 5-6 MILES
AT DODGE CITY AND HAYS AT THE BEGINNING OF THIS TAF PERIOD BUT VFR
CONDITIONS SHOULD QUICKLY RETURN AND PREVAIL THROUGH THE REMAINDER OF
THE PERIOD. SOUTHERLY WINDS WILL SWITCH AROUND TO THE WEST BY 12Z AND
INCREASE INTO THE 10 TO 15 KNOT RANGE DURING THE MORNING HOURS.
&&
.FIRE WEATHER...
ISSUED AT 403 AM CDT SUN MAR 11 2012
RED FLAG WARNING CRITERIA MAY BE MET TUESDAY BEHIND THE SURFACE DRYLINE
ALONG AND WEST OF A LINE FROM DIGHTON TO GARDEN CITY TO LIBERAL.
MID-LEVEL MOMENTUM IS EXPECTED TO EASILY MIX TO THE SURFACE DURING
THE AFTERNOON WITH WIND GUSTS AS HIGH AS 25-30 KTS FOR A FEW
HOURS, ALONG WITH RELATIVE HUMIDITY VALUES BETWEEN 10 AND 15
PERCENT.
FIRE WEATHER MAY ALSO BE A CONCERN JUST ABOUT EVERY DAY IN FAR
SOUTHWEST KANSAS BEHIND THE DRYLINE FROM WEDNESDAY THROUGH THE
WEEKEND, BUT PARTICULARLY FROM FRIDAY INTO SUNDAY AS SURFACE
PRESSURES FALL IN THE LEE OF THE ROCKIES AND SURFACE WINDS
INCREASE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 77 41 83 46 / 0 0 0 0
GCK 76 39 82 42 / 0 0 0 0
EHA 75 38 82 41 / 0 0 0 0
LBL 76 39 81 42 / 0 0 0 0
HYS 78 42 82 46 / 0 0 0 0
P28 78 44 81 53 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ065-066-
079>081-089-090.
&&
$$
UPDATE...BURKE
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
347 AM CDT MON MAR 12 2012
...UPDATED FOR SHORT TERM DISCUSSION...
.UPDATE...
ISSUED AT 821 PM CDT SUN MAR 11 2012
THE UPPER LEVEL LOW WAS PULLING OUT FASTER THAN PREVIOUSLY
THOUGHT, AS WAS THE LOW LEVEL PRESSURE SYSTEM. A FEW SHOWERS MAY
MOVE THROUGH THE NORTHEASTERN SIDE OF OUR CWA IN THE WRAPAROUND,
BUT THESE SHOULD BE FAR AND FEW BETWEEN, AND VERY LIGHT IN
PRECIPITATION AMOUNTS. WILL ONLY LEAVE PRECIP CHANCES IN THE
NORTHEAST FOR A FEW HOURS, THEN DIMINISH THEM ALL TOGETHER. I
REDUCED QPF TO .01-INCH. THE REST OF FORECAST WILL REMAIN THE
SAME.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 323 PM CDT SUN MAR 11 2012
THE THEME FOR THE EXTENDED PERIOD IS WARM TEMPS (WELL ABOVE NORMAL
TEMPERATURES...20 TO 30 DEGREES ABOVE NORMAL) AND SOME SMALL CHANCES
FOR THUNDERSTORMS LATE IN THE PERIOD.
FOR TUESDAY, THE LEE SURFACE TROUGH WILL STRENGTHEN WITH SW 20 TO 30
KT OF WIND DEVELOPING AT 850 HPA AND AROUND 15 TO 20 MPH
SOUTHWESTERLY DOWNSLOPE WINDS EXPECTED AT THE SFC. THIS WILL RESULT
IN A WELL MIXED ATMOSPHERE WITH RESULTANT GUSTY SOUTHWESTERLY WINDS.
MIXING FROM FORECAST SOUNDINGS IS EXPECTED TO ABOUT 700 HPA. MIX
DOWN TEMPERATURES SUPPORT LOW TO MID 80S DEG F ACROSS MUCH OF SW
KANSAS. DEWPOINTS WILL MIX DOWN TO LOW 20S DEG F TO POSSIBLY UPPER
TEENS DEG F WHICH WILL RESULT IN RH`S CRASHING DOWN TO 10 TO 15
PERCENT. AS A RESULT OF THE AFOREMENTIONED CONCERNS, HAVE ISSUED A
FIRE WEATHER WATCH (RFW) FOR TUESDAY AFTERNOON FOR FAR WESTERN
KANSAS.
BEYOND TUESDAY, A BROAD UPPER AND LOW LEVEL RIDGE ACROSS THE
SOUTHEAST ALONG WITH CONTINUED LEE SURFACE TROUGHING WILL RESULT IN
RETURN FLOW ACROSS THE SOUTHERN/CENTRAL PLAINS. THE DRYLINE SHOULD
BEGIN TO SHARPEN WEDNESDAY WITH UPPER 50S DEG F DEWPOINTS SOUTH OF
THE DRYLINE LOCATED ACROSS SOUTH CENTRAL/SE KANSAS. THE INCREASING
DEWPOINTS WILL LEAD TO MILD LOWS TOWARDS KP28 THROUGH THE REST OF
THE PD.
THE DRYLINE WILL EVENTUALLY MIX WESTWARD AS UPPER LEVEL FLOW BECOMES
MORE MERIDIONAL. THE EXACT DRYLINE POSITION FOR ANY GIVEN DAY IS
UNCERTAIN AT THIS POINT, HOWEVER...THE GENERAL TREND IN THE MODELS
IS TO MIX THE DRYLINE WESTWARD THROUGH THE END OF NEXT WEEK.
THE DRYLINE IN COMBINATION WITH WEAK IMPULSES EMBEDDED IN THE FLOW
ALOFT COULD LEAD TO SOME ISOLATED CONVECTION BEGINNING THURSDAY AND
CONTINUING THROUGH THE WEEKEND. DID NOT DEVIATE FROM THE ALLBLEND
APPROACH AS CONFIDENCE IN STORM INITIATION IS LOW AT THIS POINT. THE
BEST LOCATION FOR SEEING THUNDERSTORM ACTIVITY WILL BE ACROSS SOUTH
CENTRAL KANSAS WHERE BETTER BOUNDARY LAYER MOISTURE/HIGHER CAPE
VALUES IS EXPECTED. CAPPING COULD BE A CONCERN, PARTICULARLY IF YOU
BUY THE WARMER AND DRIER ECMWF.
LOOKING AT WEEK TWO, THE MODELS CONTINUE TO STRUGGLE WITH TIMING OF
THE EJECTION OF THE UPPER LEVEL TROUGH. BY MARCH 19TH, UL FLOW
BECOMES STRONGER AND MORE SOUTHERLY. CAPE VALUES FROM THE ECMWF SHOW
AROUND 2000 J/KG AND 0 TO 6 KM SHEAR INCREASES TO AROUND 50 KT. AT
SOME POINT SEVERE WEATHER COULD BE A SIGNIFICANT CONCERN...
PARTICULARLY AS THE UPPER LEVEL WAVE FINALLY EJECTS OUT ACROSS THE
PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1230 AM CDT MON MAR 12 2012
SOME EARLY MORNING MIST COULD REDUCE VISIBILITIES DOWN TO 5-6 MILES
AT DODGE CITY AND HAYS AT THE BEGINNING OF THIS TAF PERIOD BUT VFR
CONDITIONS SHOULD QUICKLY RETURN AND PREVAIL THROUGH THE REMAINDER OF
THE PERIOD. SOUTHERLY WINDS WILL SWITCH AROUND TO THE WEST BY 12Z AND
INCREASE INTO THE 10 TO 15 KNOT RANGE DURING THE MORNING HOURS.
&&
.FIRE WEATHER...
ISSUED AT 403 AM CDT SUN MAR 11 2012
RED FLAG WARNING CRITERIA MAY BE MET TUESDAY BEHIND THE SURFACE DRYLINE
ALONG AND WEST OF A LINE FROM DIGHTON TO GARDEN CITY TO LIBERAL.
MID-LEVEL MOMENTUM IS EXPECTED TO EASILY MIX TO THE SURFACE DURING
THE AFTERNOON WITH WIND GUSTS AS HIGH AS 25-30 KTS FOR A FEW
HOURS, ALONG WITH RELATIVE HUMIDITY VALUES BETWEEN 10 AND 15
PERCENT.
FIRE WEATHER MAY ALSO BE A CONCERN JUST ABOUT EVERY DAY IN FAR
SOUTHWEST KANSAS BEHIND THE DRYLINE FROM WEDNESDAY THROUGH THE
WEEKEND, BUT PARTICULARLY FROM FRIDAY INTO SUNDAY AS SURFACE
PRESSURES FALL IN THE LEE OF THE ROCKIES AND SURFACE WINDS
INCREASE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 77 41 83 46 / 0 0 0 0
GCK 76 39 82 42 / 0 0 0 0
EHA 75 38 82 41 / 0 0 0 0
LBL 76 39 81 42 / 0 0 0 0
HYS 78 42 82 46 / 0 0 0 0
P28 78 44 81 53 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ065-066-
079>081-089-090.
&&
$$
UPDATE...BURKE
SHORT TERM...GERARD
LONG TERM....SUDDEN
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
414 AM EDT MON MAR 12 2012
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 411 AM EDT MON MAR 12 2012
WV IMAGERY AND RUC ANALYSIS SHOWING UPPER LOW SPINNING OVER ERN
NEB. BROAD AREA OF LIGHT/MOD RAIN ON RADAR/OBS COVERING MUCH OF WI
AT THIS TIME AND PUSHING N. THIS WILL BE THE INITIAL FEATURE OF
CONCERN FOR THE FIRST PART OF THE MORNING.
THIS PCPN IS LOCATED ALONG AN AREA OF H925-700 WAA/FGEN...ALONG WITH
290-300K ISENTROPIC ASCENT. IN ADDITION...NOSE OF UPPER JET ROTATING
AROUND THE BASE OF THE UPPER LOW IS FOCUSED OVER WI AND WITH THE
AREA OF PCPN. HAVE DEFINITE POPS PUSHING N ACROSS THE CWA AS THIS
AREA OF RAIN PUSHES N...BUT THERE IS CONCERN ON WHETHER THIS WILL
HOLD TOGETHER. MODELS CONSISTENT ON THIS AREA OF FORCING DIMINISHING
AND SHEARING OUT AS IT PUSHES N INTO THE CWA EARLY THIS MORNING AND
ENCOUNTERS EXISTING DRY AIR. HIRES MODELS...INCLUDING
RUC/HRRR...HAVE BEEN HANDLING THE COVERAGE OF THE RAIN WELL THIS
MORNING AND ALSO SHOW THE PCPN DIMINISHING AS IT MOVES OVER THE NRN
HALF OF THE CWA. PCPN MAY ACTUALLY END FOR A PERIOD OF TIME OVER
PORTIONS OF THE SW CWA SHORTLY AFTER MORNING DRIVE TIME. EXPECT LOW
CLOUDS TO REMAIN IN PLACE BEHIND THIS INITIAL SURGE OF RAIN...AS DRY
AIR ABOVE H850 ROTATES THROUGH. SHOULD ALSO SEE SOME FOG DEVELOP
THROUGH THE MORNING...ESPECIALLY FOR AREAS FAVORED BY UPSLOPE SE
FLOW...INCLUDING NCNTRL UPPER MI AND THE KEWEENAW.
AFTER A BRIEF REPRIEVE BEHIND THIS INITIAL BAND OF RAIN...SECONDARY
SURGE LOOKS TO ARRIVE TOWARDS MID DAY AND CONTINUE INTO THE AFTN.
THIS IS ASSOCIATED WITH THE UPPER LOW AND SFC TROUGH PUSHING NE
INTO THE CWA. NOSE OF THE UPPER JET WILL BE FOCUSED OVER LOWER MI
AT THIS TIME...BUT FORCING FROM THE UPPER LOW AND ASSOCIATED HEIGHT
FALLS SHOULD BE SUFFICIENT TO REDEVELOP SCT/NUMEROUS SHOWERS THAT
MOVE FROM SW TO NE ACROSS THE CWA. COULD EVEN HAVE A FEW RUMBLES OF
THUNDER OVER PORTIONS OF THE SRN HALF OF THE CWA THIS AFTN WITH ANY
OF THE STRONGER SHOWERS. WITH THE UPPER LOW AND STRONG HEIGHT FALLS
MOVING THROUGH THIS AFTN...MID LVL LAPSE RATES INCREASE AND CREATES
POCKETS OF WEAK INSTABILITY. HAVE EXPANDED THE PREVIOUS ISOLATED
THUNDER MENTION SLIGHTLY BASED OFF LATEST TRENDS. AS WINDS TURN TO
THE SW IN THE AFTN...EXPECT FOG TO BECOME MORE PATCHY...AS MODELS
INDICATE A LITTLE DEEPER MIXING. DELAYED THE DIMINISHING FOG A
LITTLE FARTHER INTO THE AFTN. CONTINUED TO LINGER THE FOG INTO THE
EVENING OVER THE E WHERE THE RELATIVELY WARM/MOIST AIR WILL BE
FLOWING OFF LK MI.
AS THE UPPER LOW MOVES OVER LK SUPERIOR LATE THIS AFTN AND
EVENING...THIRD WAVE OF RAIN WILL AFFECT MAINLY THE WRN HALF OF THE
CWA. THIS IS ASSOCIATED WITH THE WRAP AROUND MOISTURE AND WEAK
290-305K ISENTROPIC ASCENT. THIS SHOULD CONTINUE THROUGH MUCH OF THE
EVENING HOURS OVER THE W HALF...AS THE BACK EDGE OF THE PCPN SLIDES
FROM MN AND THROUGH THE AREA. WITH THE MOISTURE AND PCPN CLOSELY
TIED WITH THE UPPER LOW...EXPECT A QUICK DIMINISHING TREND TO
POPS/SKY AFTER MIDNIGHT TONIGHT AS THE LOW MOVES INTO ONTARIO.
OVERALL...TRYING TO TIME THESE FEATURES IS EXTREMELY
DIFFICULT...ESPECIALLY WITH THE SEVERAL PERIODS OF RAIN. HAVE OPTED
TO GO WITH A SHOWERY WORDING INSTEAD OF STRATIFORM DUE TO THESE
PERIODS.
TUES...UPPER LOW THAT PASSED THROUGH THE AREA TODAY AND THIS EVENING
WILL PHASE WITH NRN STREAM TROUGH JUST TO THE N OF LK SUPERIOR ON
TUES. THIS WILL LEAD TO NW FLOW ALOFT ON TUES...BUT TROUGH IS
QUICKLY SHIFTING EAST. SOME DIFFERENCES IN HOW FAR S THE PHASING
OCCURS...WHICH COULD LEAD TO SOME LINGERING CLOUDS OVER THE KEWEENAW
AND FAR ERN UPPER MI. 18Z/00Z GFS WAS MUCH FARTHER S THAN OTHER
MODELS...WHICH ACTUALLY HOLDS PCPN INTO THE MORNING HOURS OVER FAR
ERN UPPER MI DUE TO THE DEEPER PHASING. WILL KEEP THE CLOUDS MAINLY
OVER NE LAKE SUPERIOR TO ACCOUNT FOR THIS UNCERTAINTY.
DECENT SPREAD IN GUIDANCE FOR HIGHS DUE TO THE DIFFERENCES IN
HANDLING THE PHASING OF THE UPPER THROUGH. MIXING TO H875-850
/AROUND 2C/ YIELDS HIGHS IN THE MID 50S...SO HAVE ADJUSTED EXISTING
HIGHS DOWN A TOUCH. WITH MAINLY NW FLOW...HAVE KEPT TEMPS NEAR LK
SUPERIOR A LITTLE COOLER. DEWPOINT VALUES WILL BE THE MAIN CONCERN
FOR TUES AFTN. DROPPED VALUES A GOOD 7-10 DEGREES OVER THE WRN
HALF OF THE CWA...WITH MODELS CONSISTENTLY SHOWING DECENT MIXING
INTO DRY AIR ALOFT. SOME OF OUR LOCAL MIXED TD TOOLS ACTUALLY GIVE
VALUES IN THE SINGLE DIGITS ABOVE ZERO...WHICH DOESN/T SEEM TOO
UNREASONABLE. STRAIGHT MODEL MIXED TD VALUES ARE IN THE LOWER
TEENS...SO HAVE TRENDED TOWARDS THAT WITH VALUES IN THE UPPER
TEENS. FORTUNATELY...THERE IS STILL A DECENT SNOW PACK...OTHERWISE
THERE COULD BE FIRE WX CONCERNS WITH GUSTY NW WINDS AND RH VALUES
FALLING INTO THE LOW 20S.
TUES NIGHT...WITH UPPER TROUGH CONTINUING E AND UPPER RIDGE
REBUILDING OVER THE NRN PLAINS...EXPECT DRY WX AND MOSTLY CLEAR
SKIES. SFC RIDGE MOVING ACROSS THE AREA WILL LEAD TO LIGHT WINDS
AND HAVE DROPPED TEMPS A FEW DEGREES. COULD SEE TEMPS FALL A LITTLE
MORE THAN EXPECTED OVER THE ERN CWA...DUE TO LIGHTER WINDS AND DRY
AIR ALOFT PRODUCING PWATS AROUND 70 PERCENT OF NORMAL. HAVE COOLED
THE TRADITIONAL COLD SPOTS SOME OVER THE ERN CWA TO BELOW FREEZING
VALUES. FINALLY...H850 WAA COULD LEAD TO A FEW CLOUDS DEVELOPING
OVER THE WRN LK AND WRN UPPER MI AFTER MIDNIGHT...BUT LIMITED
MOISTURE HAS CONFIDENCE LOW.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 411 AM EDT MON MAR 12 2012
WED...THE UPR RDG OVER THE GRT LKS WL MOVE SLOWLY TO THE E...BUT ITS
EWD PROGRESS WL BE SLOWED BY CUTOFF LO OVER NEW ENGLAND. AS A FAIRLY
STRONG DISTURBANCE MOVES INTO CNTRL CAN...ITS ATTENDANT TROF WL
APRCH THE UPR LKS BY LATE IN THE DAY. THE NAM IS THE FASTEST MOVING
THIS TROF ACRS THE CWA ON WED...BUT PREFER THE CONSENSUS OF THE
SLOWER MODELS GIVEN THE BLOCKING CUTOFF IN NEW ENGLAND. THESE MODELS
HINT THE TROF WL REACH THE W ONLY LATE IN THE DAY. WITH THE DRYNESS
OF THE ANTECEDENT AIRMASS AND A LACK OF ANY SGNFT UPR FORCING SO FAR
S OF THE DISTURBANCE MOVING THRU CNTRL CAN...OPTED TO RETAIN GOING
DRY FCST. WITH H85 TEMPS PEAKING ARND 10C...EXPECT ANOTHER DAY OF
WELL ABV NORMAL TEMPS...EVEN IF THE MORE PESSIMISTIC GFS IS CORRECT
ON SHOWING ENUF LLVL MSTR ARRIVING TO SUPPORT SC DEVELOPMENT IN THE
SW FLOW AHEAD OF THE INCOMING TROF. MIXING TO JUST H875 ON GFS FCST
SDNGS WOULD YIELD HI TEMPS APRCHG 70 AWAY FM THE MODIFIYING
INFLUENCE OF LK MI WITH LLVL SLY FLOW...ESPECIALLY IN THE DOWNSLOPE
AREAS W OF MQT. SUSPECT AT LEAST SOME PLACES OVER THE W HALF MAY SEE
DAILY RECORD HI TEMPS.
WED NGT...AS THE SFC TROF/PACIFIC TYPE COLD FNT MOVES E ACRS THE
CWA...THE 00Z GFS AND ESPECIALLY THE CNDN MODELS ARE MOST AGGRESSIVE
AT GENERATING SOME PCPN OVER MAINLY THE SE ZNS UNDER AREA OF STEEPER
H7-5 LAPSE RATES UP TO 7.5-8.0C/KM AND SHOWALTER INDEX AS LO AS -2
TO -4C. THE CNDN INSTABILITY IS GREATER AS THIS MODEL SHOWS A
STRONGER SHRTWV MOVING ENEWD IN THE WSW FLOW ALF. ALTHOUGH THE TIME
OF DAY WOULD NOT BE CONDUCIVE TO TS...OPTED TO INCLUDE SCHC TS OVER
THE SE ZNS CONSIDERING THE ANOMALOUS LLVL WARMTH OF THE ANTECEDENT
AIRMASS/FCST STABILITY INDICES. DRIER AND SOMEWHAT COOLER AIR WL
ARRIVE OVER ESPECIALLY THE W IN THE WAKE OF THE COLD FROPA AS WEAK
HI PRES MOVES TO THE MN ARROWHEAD BY 12Z THU.
EXTENDED...THE STEADY SLY FLOW BTWN WRN TROF/ERN RDG WL PERSIST THRU
THE WEEKEND WITH NEAR UNPRECEDENTED WARMTH POSSIBLE FRI THRU SUN IN
THE PRESENCE OF H85 TEMPS NOT FAR FM 10-12C. THE THU-FRI PERIOD
SHOULD BE DRY WITH HI PRES RDG OVER THE AREA...BUT THERE WL BE A CHC
OF SHRA OVER THE WEEKEND AS HI PRES SHIFTS TO THE E. LACK OF
CONSISTENCY ON SHRTWV PRESENCE/TIMING SUGS NO MORE THAN CHC POPS ARE
WARRANTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 126 AM EDT MON MAR 12 2012
A MID LEVEL LOW PRESSURE SYSTEM DEVELOPING OVER ERN KS WILL LIFT
NORTHEAST INTO NW WI BY MONDAY AFTERNOON. S-SE WINDS AHEAD OF THIS
FEATURE WILL BRING IN INCREASING LOW-LVL MOISTURE AND A BAND OF RAIN
SHOWERS LATE TONIGHT AND MONDAY. EXPECT CONDITIONS TO QUICKLY FALL
FROM VFR TO IFR AND THEN TO ALT LANDING MINS AT KCMX AND KSAW BY
LATE MORNING MONDAY IN SE-E WIND UPSLOPE FOG AND STRATUS. SNOW PACK
WILL LIKELY ENHANCE FOG POTENTIAL. LOOK FOR CONDITIONS TO IMPROVE TO
IFR AS KCMX AND KSAW BY MID MONDAY AFTERNOON AS RAIN TAPERS OFF AND
WINDS VEER MORE TO THE SW. CONDITIONS AT KCMX AND KSAW MAY DIP BACK
DOWN TO ALT LANDING MINS MON EVENING AS NOCTURNAL FALL IN TEMPS AND
LINGERING LOW-LVL MOISTURE LEADS TO SATURATION. CONDITIONS WILL
LIKELY IMPROVE TO MVFR AT KIWD BY LATE MONDAY EVENING AS DRIER AIR
ADVECTS IN FROM THE WEST BEHIND SYSTEM/S COLD FRONT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 AM EDT MON MAR 12 2012
UPPER LEVEL DISTURBANCE AND SURFACE TROUGH WILL SLIDE NE ACROSS
LAKE SUPERIOR THIS AFTERNOON AND TONIGHT. EXPECT SSE WINDS TO
MAINLY STAY BELOW 20KTS...BUT THERE COULD BE A FEW GUSTS TO 25KTS
OVER THE NRN LK. AS WARM/MOIST AIR MOVES OVER LAKE SUPERIOR
TODAY...SHOULD SEE AREAS OF FOG DEVELOP LATE THIS MORNING AND
CONTINUE INTO THIS EVENING. BEHIND THE SURFACE TROUGH...EXPECT
WINDS TO INCREASE OUT OF THE WEST AFTER MIDNIGHT AND CONTINUE INTO
TUESDAY. WARM AIR ABOVE THE SURFACE WILL LIKELY KEEP THE MARINE
LAYER IN PLACE AND LIMIT THE VERY STRONG WINDS ALOFT FROM
REACHING THE SURFACE. AT THIS TIME...ONLY HAVE GUSTS REACHING
30KTS. AFTER TUESDAY...WINDS WILL REMAIN UNDER 25KTS WITH A
RELATIVELY WEAK PRESSURE GRADIENT IN PLACE.
&&
.HYDROLOGY...
ISSUED AT 411 AM EDT MON MAR 12 2012
NEAR RECORD TO RECORD SETTING TEMPS YESTERDAY HAS HELPED RIPEN THE
SNOW PACK. RAIN TODAY AND FOR PARTS OF TONIGHT WILL PROVIDE
ADDITIONAL MOISTURE TO THE AREA. EXPECT THE BULK OF THE
RAIN TO FALL DURING THE MORNING TO EARLY AFTERNOON HOURS...WITH
ACCUMULATIONS OF AROUND 0.25 TO 0.40IN. THE RAIN...COMBINED
WITH DEWPOINTS RISING INTO THE 40S...WILL HELP TO QUICKEN
SNOWMELT. AS OF THIS MORNING...THERE HAS BEEN ONLY LIMITED
RESPONSES ON THE LARGER RIVERS.
THE RAIN AND SNOW MELT TODAY...COMBINED WITH ABOVE NORMAL
TEMPERATURES THROUGH NEXT WEEKEND WILL LEAD TO A INCREASE IN
RIVER AND STREAM LEVELS OVER THE NEXT SEVERAL DAYS. EXPECT SOME OF
THE RIVERS ACROSS THE AREA TO EXCEED THEIR BANKS BY THE END OF THIS
WEEK. PERSONS LIVING NEAR RIVERS AND STREAMS SHOULD
MONITOR THE LATEST RIVER CONDITIONS AND USE CAUTION IF WALKING
ALONG RIVER BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
ICE JAM WISE...NOT MUCH ICE HAS BEEN NOTED BY OBSERVERS ON THE
FASTER FLOWING RIVERS OVER NRN UPPER MI. BUT THE FORD RIVER...BOTH
AT HYDE AND THE MOUTH AT LK MI...STILL HAS GOOD ICE COVER THAT
LEADS TO SOME CONCERN FOR ICE JAM POTENTIAL WITH THE FASTER RUNOFF.
ALTHOUGH LIMITED SNOW WAS NOTED NEAR LK MI...THERE IS STILL 4-9IN
OF SNOW ...AND NOHRSC ESTIMATED AROUND 1.25IN OF LIQUID...TOWARDS
THE HEADWATERS THAT WILL BE MELTED OVER THE COMING DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...VOSS
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
124 AM EDT MON MAR 12 2012
.UPDATE...
ISSUED AT 1018 PM EDT SUN MAR 11 2012
LATEST WATER VAPOR IMAGERY SHOWS A WELL DEFINED UPPER LOW MOVING
TOWARD THE WESTERN GREAT LAKES. REGIONAL RADAR SHOWS A STEADY
INCREASE IN PCPN SOUTHWEST OF THE CWA. BASED ON RADAR TRENDS AND
LATEST RUC DATA...WE INCREASED POPS OVERNIGHT. THUNDER STILL A
POSSIBILITY AFTER 06Z AS THETA-E DECREASES WITH HEIGHT.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 337 PM EDT SUN MAR 11 2012
FORECAST IMPACTS REVOLVE AROUND SEVERE THREAT MONDAY AFTERNOON AND
EVENING. SPC CURRENTLY HAS UPGRADED MUCH OF SOUTHERN AND CENTRAL
LOWER MICHIGAN TO A SLIGHT RISK FOR DAY 2 BUT THIS IS CONDITIONAL ON
AIRMASS RECOVERY/SFC HEATING IN DRY SLOT AFTER FIRST BATCH OF
SHOWERS AND STORMS MOVES THROUGH LATE TONIGHT AND EARLY MONDAY
MORNING.
12Z NAM IS MOST BULLISH ON SEVERE THREAT SHOWING MUCH BETTER
INSTABILITY MONDAY AFTERNOON WITH SFC HEATING AND STEEP LAPSE RATES
IN THE DRY SLOT...WHILE 12Z GFS AND ECMWF SUGGEST LESS SFC BASED
INSTABILITY BUT STILL SOME POTENTIAL FOR CONVECTION AS SHEAR
PROFILES AND HELICITIES WOULD SUPPORT STRONG TO SEVERE STORMS
INCLUDING ROTATING UPDRAFTS IF SFC BASED INSTABILITY IS REALIZED.
FOR TONIGHT...LEADING EDGE OF SHOWERS SHOULD ARRIVE ACROSS THE FAR
SOUTHWEST CWA AFTER MIDNIGHT AND SPREAD NORTH. BEAST CHANCE FOR RAIN
WILL BE FROM 08Z TO 14Z AS THIS FIRST BATCH MOVES THROUGH. FORECAST
SOUNDINGS SUGGEST MARGINAL ELEVATED INSTABILITY...BUT ENOUGH TO
INCLUDE ISOLATED THUNDER IN THE FORECAST.
THEN THE DRY SLOT ARRIVES AND THERE SHOULD BE A LULL BETWEEN 14Z AND
18Z...FOLLOWED BY POTENTIAL FOR MORE CONVECTION AS SECONDARY SPEED
MAX ROTATES THROUGH DURING THE LATE AFTERNOON AND EARLY EVENING.
GIVEN STRONG SPEED SHEAR PROFILES AND DECENT LOW LEVEL
HELICITIES...CONVECTIVE TRENDS WILL HAVE TO BE CLOSELY MONITORED
DURING THE AFTERNOON AND EVENING. THREAT DECREASES AFTER 00Z WITH
LOSS OF SFC BASED INSTABILITY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 337 PM EDT SUN MAR 11 2012
UNSEASONABLY WARM WX ANTICIPATED THRU THE LONG RANGE FCST PERIOD
WITH TEMPS AVERAGING 20 TO 25 DEGREES ABOVE NORMAL THROUGH THE
WEEKEND INTO EARLY NEXT WEEK. HIGH PRESSURE WILL BRING FAIR AND VERY
WARM WX TUE/WED WITH MAX TEMPS REACHING THE UPPER 50S TO LOWER 60S
TUE AND UPPER 60S TO LOWER 70S WED.
A WEAK FRONTAL BOUNDARY WILL BRING A FEW SHOWERS WEDNESDAY NIGHT AND
A FEW SHOWERS MAY LINGER THURSDAY THROUGH SATURDAY AS THE SW FLOW
WARM AIR ADVECTION PATTERN CONTINUES. HOWEVER COVERAGE OF ANY
SHOWERS THUR-SAT SHOULD BE LOW AND MOST OF THE TIME DRY CONDITIONS
WILL CONTINUE ALONG WITH UNSEASONABLY WARM CONDITIONS.
SOME OF THE WARMEST WEATHER OF ALL SHOULD COME SUNDAY AND ESPECIALLY
MONDAY OF EARLY NEXT WEEK AS A HIGH AMPLITUDE RIDGE/OMEGA BLOCK
DEVELOPS RIGHT OVER THE GREAT LAKES REGION AS A DEEP TROF CARVES
ITSELF OUT OVER THE ROCKIES. IT IS POSSIBLE THAT THE FIRST 80 DEGREE
READING OF THE YEAR COULD COME BY NEXT MONDAY AS H5 HEIGHTS REACH
580 DM WITH H8 TEMPS POTENTIALLY REACHING 14-16C BY THEN. MEX
NUMERICAL GUIDANCE MAX TEMPS ARE BEING SKEWED DOWN TOO MUCH BY CLIMO
VALUES FOR NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 120 AM EDT MON MAR 12 2012
RADAR SHOWS LIGHT RAIN MOVING TOWARD LOWER MICHIGAN. CIGS WILL
FALL TO MVFR OVERNIGHT AS THE RAIN MOVES IN. NOT EXPECTING TSRA AT
THE TAF SITES OVERNIGHT. A QUESTION MARK REMAINS CONCERNING STORMS
LATER THIS AFTERNOON. SOME INGREDIENTS EXIST FOR STRONG TO SEVERE
STORMS MAINLY AFTER 20Z AT THE THE SRN TAF SITES. WE COVERED THIS
WITH A VCTS COMMENT. IT/S POSSIBLE COVERAGE COULD BE MORE
WIDESPREAD THAN THAT BUT CONFIDENCE WASN/T HIGH ENOUGH TO PUT AS A
PREDOMINATE GROUP.
&&
.MARINE...
ISSUED AT 337 PM EDT SUN MAR 11 2012
DROPPED THE SCA FOR ALL BUT THE NORTHERN MARINE ZONE BASED ON
CURRENT OBS AND TRENDS. CONDITIONS SHOULD IMPROVE OVERNIGHT BUT
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AFTER MIDNIGHT.
&&
.HYDROLOGY...
ISSUED AT 337 PM EDT SUN MAR 11 2012
SOME RISES ARE POSSIBLE THIS WEEK AS RAIN AND THUNDERSTORMS ARE
POSSIBLE MONDAY AFTERNOON AND THURSDAY INTO THURSDAY NIGHT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...93
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM....LAURENS
AVIATION...93
MARINE...OSTUNO
HYDROLOGY...OSTUNO
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1234 AM CDT MON MAR 12 2012
.AVIATION...
THE UPPER LOW WILL CONTINUE CROSSING EASTERN NEBRASKA OVERNIGHT
AND WIDESPREAD RAIN WILL CONTINUE EAST OF A VTN-MHN-LBF LINE AND
SLOWLY END FROM THE WEST. IT IS LIKELY TO MOVE EAST OF AN ONL-BBW
LINE BY 15Z. WITH THE RAIN...LOW CEILINGS 800-1200 FEET AGL AND
VISIBILITY AT OR BELOW 3SM CAN BE EXPECTED. CEILING IN THE REST OF
THE AREA WILL BE AT OR ABOVE 4000 FEET AGL WITH UNRESTRICTED
VISIBILITY.
WIND AT VTN AND LBF IS EXPECTED TO SWITCH TO THE NORTHWEST
09-12Z AND BECOME 290-320 AT 12-16G24-28KT 14-18Z.
&&
.PREV DISCUSSION... /ISSUED 653 PM CDT SUN MAR 11 2012/
SHORT TERM UPDATE...
BASED ON RADAR AND RECORDED PRECIPITATION AMOUNTS...WE HAVE
UPDATE THE FORECAST FOR TONIGHT FOR HIGHER PROBABILITY OF
PRECIPITATION AND SLIGHTLY HIGHER PRECIPITATION AMOUNTS FOR THIS
EVENING IN NORTH CENTRAL THROUGH SOUTHWEST NEBRASKA EAST OF A LINE
FROM VALENTINE THROUGH MULLEN AND OGALLALA TO IMPERIAL.
&&
.PREV DISCUSSION... /ISSUED 310 PM CDT SUN MAR 11 2012/
DISCUSSION...
THE UPPER LEVEL LOW ACROSS ERN COLO/WRN KS WILL LIFT SLOWLY NORTHEAST
THRU ERN NEB OVERNIGHT. CURRENT RADAR TRENDS AND THE RUC SUGGEST
ISOLATED SHOWERS THIS EVENING AS FAR WEST AS SWRN NEB WHICH THEN
SPREAD NORTHEAST OVERNIGHT AND EXIT THE FCST AREA BY ROUGHLY 12Z
MONDAY.
ANOTHER BIG FIRE DAY IS POSSIBLE MONDAY. BLENDED BIAS CORRECTED
MET MAV DEW PT DATA POINTS TOWARD DEW POINTS IN THE UPPER TEENS.
MEANWHILE THE STRONGER MAV WINDS AND ASSOCIATED DEEPER MIXING
PRODUCES STRONGER WINDS. SO RED FLAG CONDITIONS ARE POSSIBLE
ACROSS A LARGE PART OF THE FCST AREA. GREATER FIRE DANGER COULD
DEVELOP TUESDAY AS LOW PRESSURE ACROSS ALBERTA AND SASKATCHEWAN
DEEPENS TO AROUND 985 MB. A DRY LINE IS FCST TO DEVELOP AND PUSH
EAST TO AROUND HIGHWAY 183 WITH WINDS GUSTING TO 25 TO 30KTS. ON
WEDNESDAY CANADIAN LOW PRESSURE WILL FORCE THE DRY LINE FARTHER
EAST TO NEAR OMAHA WHICH COULD ALSO PRODUCE CRITICAL FIRE DANGER.
TEMPERATURES CONTINUE TO SOAR IN ALL MODEL SOLNS THROUGH WEDNESDAY.
THE CANADIAN LOW PRESSURE SYSTEMS WILL TRACK FAR ENOUGH NORTH TO
PREVENT ANY KIND OF STRONG COLD FRONTS AND COOLER TEMPS FROM
MOVING THROUGH THE FCST AREA BUT IT APPEARS THE SYSTEMS WILL BE
STRONG ENOUGH TO PREVENT THE DRY LINE FROM BACKING UP VERY FAR
WEST. THIS IS VERY UNCERTAIN AT THIS POINT AS WE HAVE YET TO SEE
THIS TYPE OF PATTERN AND IN WET YEARS THE DRY LINE TENDS TO HANG
OUT AROUND HIGHWAY 61.
THE GFS CONTINUES TO INDICATE SOME CIRRUS TUESDAY AND WEDNESDAY
BUT THIS SHOULD BE A FAIRLY THIN VEIL AND HAVE ONLY MINOR IMPACT ON
MAX TEMPS.
THURSDAY THROUGH SUNDAY...THE ECM CONTINUES TO KEEP A DEVELOPING
LONG WAVE TROF WEST OF THE FCST AREA. WITH NO SIGNIFICANT NRN
STREAM LEAD SHORT WAVE...THE FCST AREA SHOULD REMAIN IN THE WARM
SECTOR. A SERIES OF LOW PRESSURE SYSTEMS LIFT OUT OF THE TROF AND
THROUGH THE ROCKIES AND HIGH PLAINS. EACH WILL SUBSEQUENTLY DRAW
HIGH PRESSURE AND COOLER TEMPS CLOSER TO THE FCST AREA. THE
EARLIEST WE MIGHT SEE COOLING IS NEXT SUNDAY WHEN WINDS MAY BACK
AROUND TO THE EAST IN RESPONSE TO DEEP LOW PRESSURE ACROSS ERN WY.
THE GFS IS FASTER BRINGING THE LONG WAVE TROF EAST QUICKER. THE
FCST LEANS TOWARD THE SLOWER ECM AND WARMER TEMPS.
THERE IS SOME SPREAD IN THE POSITION OF A VERY STRONG DRY LINE FCST
TO DEVELOP ACROSS CNTL NEB IN THE EXTENDED FCST. ALL SOLNS INDICATE
DEW POINTS IN THE 50S ACROSS ERN NEB WITH 20S OVER WRN NEB. THESE
DIFFERENCES APPEAR TO BE RELATED TO THE TIMING...LOCATION AND
INTENSITY OF THE DISTURBANCES LIFTING OUT OF THE LONG WAVE TROF.
THE MODELS APPEAR TO BE DEVELOPING A BROAD AREA OF NOCTURNAL
STRATUS IN THE DEEPER MOISTURE EAST OF THE DRY LINE SO THE POSITION OF THE
DRY LINE WILL BE CLOSELY WATCHED. LATER MODEL SOLNS MAY SHOW THE
DRY LINE BACKING UP WESTWARD TOWARD A MORE CLIMATOLOGICAL
LOCATION.
FIRE WEATHER...
A FIRE WEATHER WATCH HAS BEEN ISSUED FOR FIRE ZONES
204...206...209...210 AND 219 MONDAY AFTERNOON. THE COMBINATION OF
CURED FUELS...WEST NORTHWESTERLY DOWNSLOPING WIND...AND ABNORMALLY
WARM TEMPERATURES WILL CREATE CONDITIONS FAVORABLE FOR EXTREME FIRE
GROWTH. ONE CAVEAT HOWEVER...WIND SPEEDS MAY BE MARGINAL /BELOW RFW
CRITERIA/ AS HIGH PRESSURE BUILDS OVER THE REGION. BUT EMPLOYING
THE USE MAV GUIDANCE WOULD INDICATE THE POTENTIAL FOR GUSTS OF 25
MPH FOR A THREE TO FOUR HOUR PERIOD EARLY MONDAY AFTERNOON. BUFR
SOUNDINGS AND OTHER GUIDANCE INDICATE A WEAKER WIND PROFILE...WITH
THE NAM GOING AS FAR AS TO SUGGEST WIND SPEEDS OF LESS THAN 20 KTS
AT 700MB OVER MUCH OF THE CWA BY 21Z CONSIDERING THAT THE MODELS
INDICATE A RELAXING PRESSURE GRADIENT...PEAK WIND SPEEDS MAY NOT
CORRESPOND WITH PEAK HEATING/MINIMUM RH. HOWEVER...THE MODELS
GENERALLY HAVE STRUGGLED RECENTLY AND UNDERESTIMATED NOT ONLY WIND
SPEEDS BUT ALSO TEMPERATURES/RH VALUES DURING PEAK HEATING...FELT
THAT CONFIDENCE WAS HIGH ENOUGH FOR AT LEAST A FIRE WEATHER WATCH AT
THIS TIME. WILL INCLUDE MOST OF WESTERN AND NORTH CENTRAL NEBRASKA
IN THIS WATCH THAT WILL BE IN EFFECT FROM 17Z MONDAY UNTIL 01Z
TUESDAY.
FIRE HEADLINES MAY BE NEEDED FOR THE REMAINDER OF NEXT WEEK AS
RIDGING BUILDS OVER THE CENTRAL AND NORTHERN PLAINS. TEMPERATURES
BEYOND MONDAY SHOULD REMAIN IN THE 70S FOR HIGHS THROUGH THE END OF
THE WORK WEEK. IN FACT...TEMPERATURES TUESDAY THROUGH THURSDAY MAY
APPROACH 80 DEGREES ALONG AND SOUTH OF THE INTERSTATE 80
CORRIDOR...AND ACROSS MUCH OF THE CENTRAL/NORTHERN SAND HILLS. WITH
CURED FUELS IN PLACE...THESE ABOVE NORMAL TEMPERATURES WILL COMBINE
WITH MEAGER ATMOSPHERIC MOISTURE AND AT TIMES GUSTY WIND SPEEDS TO
CREATE CONDITIONS FAVORABLE FOR EXTREME FIRE BEHAVIOR. ALL FIRE
INTERESTS SHOULD MONITOR THIS SITUATION CLOSELY UNTIL APPRECIABLE
MOISTURE FALLS OR GREEN UP OCCURS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR NEZ204-206-209-210-219.
&&
$$
SHORT TERM/EXTENDED...CDC
FIRE WEATHER...JACOBS
AVIATION/SHORT TERM UPDATE...SPRINGER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
335 AM CDT MON MAR 12 2012
.SHORT TERM...MAIN CONCERNS WILL BE RAIN AND QPF ALONG WITH WIND
SPEEDS TODAY. 00Z MODELS IN DECENT AGREEMENT WITH SYNOPTIC
FEATURES AND WILL USE A BLEND.
UPPER LOW WILL PROPAGATE THROUGH IOWA AND INTO THE GREAT LAKES
REGION BY THIS EVENING...WHILE ANOTHER SHORTWAVE ACROSS THE NW
CONUS WILL PROPAGATE INTO THE NORTHERN FA. THESE TWO WAVE WILL
MAKE FOR A COMPLICATED FORECAST SCENARIO. MODELS APPEAR TO BE
HINTING THAT A BAND OF MODERATE RAIN WILL SET UP SOMEWHERE ACROSS
THE FA AND SLOWLY MOVE EAST. THIS BAND WILL BE ASSOCIATED WITH
STRONG 850-700MB FRONTOGENESIS...SYMMETRIC INSTABILITY...AND PWATS
UP TOWARD 0.9 INCHES. GIVEN THE BANDING POTENTIAL...THINK THAT
LOWER RESOLUTION MODELS ARE UNDERESTIMATING QPF POTENTIAL (SHOWING
UP TO 0.25 INCHES). HIGHER RESOLUTION MODELS ARE INDICATING 0.50
TO 1.00 INCH...WHICH APPEARS POSSIBLE GIVEN THE FORCING
MECHANISMS AND AVAILABLE MOISTURE. THE MAIN QUESTION IS WHERE WILL
THE BAND SET UP...AND HOW FAR NORTH WOULD THE HIGHER RAIN TOTALS
BE. MUCH DEPENDS ON THE EXACT SPEED OF THE EACH WAVE. WILL FOLLOW
THE HRRR AND RUC WHICH APPEAR TO HAVE A HANDLE ON THE CURRENT
RADAR TRENDS. GIVEN THESE MODELS...AND CURRENT RADAR...IT APPEARS
THIS BAND OF RAIN WILL BE LOCATED FROM THE SOUTHWEST FA INTO THE
NE FA THIS MORNING. HRRR AND RUC INDICATING STRONGER FORCING
ACROSS THE SOUTHERN FA...WITH THE HIGHER QPF TOTALS ACROSS THE
SOUTHERN VALLEY. GIVEN UNCERTAINTY...WILL GO WITH AREAL AVERAGE
QPF 0.30-0.50 INCHES WITHIN THIS EXPECTED RAIN BAND (PLUS 1.0 INCH
RAINFALL WOULD LIKELY BE ISOLATED). WILL TRY TO REFINE THIS ONCE
MORE CONFIDENCE IS OBTAINED. AS THE SECOND KICKER WAVE
APPROACHES...CLEARING SHOULD MOVE THROUGH FROM WEST TO EAST BY
THIS EVENING.
MODELS INDICATE STRONG 850MB COLD AIR ADVECTION WITH WINDS 40-43
KNOTS AT THIS LEVEL ACROSS THE DEVILS LAKE BASIN BY THIS
AFTERNOON. WILL ISSUE A WIND ADVISORY FOR THIS AREA. THE COLD AIR
ADVECTION WEAKENS AS IT MOVES EAST...WHICH SHOULD KEEP ADVISORY
CONDITIONS CONFINED TO THE DEVILS LAKE BASIN. TEMPERATURE TRICKY
TODAY...BUT THINK SOME SOLAR WILL GET TEMPS INTO THE 50S VALLEY
AND WEST (40S WHERE CLOUD COVER EXPECTED MUCH OF THE DAY).
PROGRESSIVE PATTERN REMAINDER OF THE PERIOD AND TIMING WILL HAVE
AFFECT ON TEMPERATURES. APPLIED A MODEL BIAS FROM THE PAST COUPLE
DAYS FOR GUIDANCE. NO MEASURABLE PRECIP EXPECTED.
.LONG TERM (THUR-SUN)...EARLY IN THE EXTENDED PERIOD MODELS IN
GOOD AGREEMENT THAT AN UPPER LOW WILL BE PASSING WELL NORTH OF THE
REGION. RESULTANT WESTERLY SURFACE FLOW WILL CONTINUE THE DRY AND
WARM WEATHER. FLAT WESTERLY FLOW GRADUALLY TRANSITIONS TO MORE
SOUTHWEST FLOW BY LATER ON FRIDAY. ECMWF SLOWER THAN THE
GFS/DGEX/GEM AND BASED ON OVERALL HEMISPHERIC PATTERN PROBABLY
BETTER.
VARIOUS ENSEMBLES IN AGREEMENT THAT BLOCKING OVER THE NORTHEAST U.S.
IN THE FORM OF VERY STRONG RIDGE WILL FAVOR DEEP TROUGH OVER EASTERN
PACIFIC/WESTERN U.S. BY SATURDAY DGEX/GFS BOTH BRING A SURGE OF
MODERATELY UNSTABLE AIR...FOR MARCH...INTO THE NORTHERN PLAINS. 45
KT 850 JET AND LI IN THE -2C TO -4C RANGE SET UP JUST AHEAD OF COLD
FRONT FORECAST TO MOVE THROUGH LATE IN THE DAY. SURFACE TD REACH THE
MID 50S WITH OPEN GULF OF MEXICO FLOW FORECAST FOR SEVERAL DAYS
AHEAD OF DEEPENING SURFACE LOW.
WHILE CLIMATOLOGICALLY NOT THE BEST TIME OF YEAR TSRA NOT UNHEARD OF
IN MID MARCH SO PUT TSRA VALLEY EAST SATURDAY AND EAST OF VALLEY
SATURDAY NIGHT. IF SLOWER ECMWF VERIFIES COULD EASILY SEE MORE
THUNDER AT END OF PERIOD.
MAX TEMPERATURES PEAK INTO THE 60S FRIDAY AND SATURDAY AHEAD OF
STRONG UPPER WAVE AND SURFACE FRONT. ATTM FORECAST TEMPERATURES TO
COOL BACK INTO THE 50S BEHIND EXPECTED FRONT.
&&
.AVIATION...MVFR CIGS EXPECTED ALONG AND EAST OF THE RED RIVER
VALLEY INTO THE AFTERNOON HOURS. A BAND OF RAIN WILL SET UP ACROSS
THE AREA...AND IFR CONDITIONS POSSIBLE WITHIN THIS BAND. VFR
CONDITIONS WILL SPREAD FROM WEST TO EAST BY LATE AFTERNOON. SOUTH
WINDS WILL BECOME NORTHWEST...AND BREEZY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY FROM 11 AM THIS MORNING TO 6 PM CDT THIS EVENING
FOR NDZ006-007-014-015-024.
MN...NONE.
&&
$$
TG/EWENS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
913 PM PDT SUN MAR 11 2012
.SYNOPSIS...A WARM FRONT WILL CONTINUE RAIN ALONG THE COAST
TONIGHT..WITH DECREASING SHOWERS ELSEWHERE. A STRONG PACIFIC FRONT
WILL BRING STRONG WINDS...HEAVY RAIN AND MOUNTAIN SNOW MONDAY. A
SERIES OF SYSTEMS WILL MAINTAIN DAMP AND COOL WEATHER THROUGH NEXT
WEEK.
&&
.UPDATE...WE HAVE UPGRADED THE STORM WARNING FOR THE COASTAL WATERS
TO A HURRIANCE FORCE WIND WARNING. MULTIPLE MESOSCALE
MODELS...INCLUDING THE UW NAM...RUC HRRR...AND THE PORTLAND WFO
LOCAL WRF BRING GUSTS TO 70KT...AND PRESSURE FALLS WELL OFFSHORE
HAVE BEEN 5 MB IN 1 HR/ 13 MB IN 3 HR.
.SHORT TERM...SHOWERS ARE WINDING DOWN THIS EVENING...BUT THERE WILL
NOT BE MUCH BREAK IN THE WEATHER...AT LEAST FOR THE COAST...AS THE
WARM FRONT ASSOCIATED WITH THE NEXT LOW IS QUICKLY APPROACHING FROM
THE WEST. SATELLITE IMAGERY SHOWS A SURFACE LOW DEVELOPING AROUND 37N
137W EARLY THIS EVENING. THIS LOW WILL DEEPEN AS IT NEARS THE COAST
AND SOUTH WINDS WILL INCREASE OFFSHORE AND ALONG THE COAST THROUGH
THE NIGHT. THIS STORM WILL BRING STRONG WINDS...HEAVY RAIN AND
MOUNTAIN SNOW MONDAY.
RAIN ASSOCIATED AHEAD OF THE WARM FRONT IS STARTING TO SHOW ON RADAR
AROUND 60 MILES OFFSHORE. LIGHT RAIN WILL CONTINUE ALONG THE COAST
THROUGH THE NIGHT BUT THE REST OF THE FORECAST AREA WILL HAVE A BRIEF
BREAK IN PRECIPITATION. MODELS CONTINUE TO SHOW THE OCCLUDED OR COLD
FRONT PUSHING STEADILY INLAND MONDAY. THE PRECIPITATION WILL BE HEAVY
AT TIMES AND EXPECT RAINFALL TOTALS TO APPROACH 2 INCHES ALONG THE
COAST AND 3 INCHES FOR THE COAST RANGE.
THE CASCADES WILL SEE PLENTY OF SNOW AND HAVE KEPT FORECAST SNOW
AMOUNTS NEAR HIGH END ADVISORY LEVELS. THE HIGHEST SNOW TOTALS AND
LONGEST DURATION OF SNOWFALL IS EXPECTED ACROSS THE SOUTH WASHINGTON
CASCADES. PRECIPITATION IN THE COAST RANGE AND CASCADE FOOTHILLS WILL
LIKELY START OUT AS SNOW MONDAY MORNING WITH A FEW INCHES POSSIBLE.
HOWEVER...WARM AIR WILL MOVE IN DURING THE DAY CAUSING A CHANGE OVER
TO RAIN.
WINDS OFFSHORE ARE ALREADY PICKING UP THIS EVENING WITH BUOY
OBSERVATIONS REPORTING GUSTS TO 41 KT. THE WIND FIELDS ASSOCIATED
WITH MONDAYS CYCLOGENIC BOMB ARE IMPRESSIVE. WHILE THE MODELS APPEAR
SET ON RUNNING THE DEEPENING LOW EARLY MON UP AROUND 130W OFF OF
VANCOUVER ISLAND...THE STRONG WINDS SURROUNDING THE STORM EXTEND
OUTWARDS CONSIDERABLY. GFS ENSEMBLES
CONTINUE TO SHOW SSW H8 WINDS OF 60 TO 70 KT OVER NW OREGON AND SW
WA MON MORNING...WHICH IS FIVE STANDARD DEVIATIONS ABOVE NORMAL. THE
UW MM5-NAM THROWS IN SOME 50 KT GUSTS IN THE WILLAMETTE VALLEY
MONDAY...BUT WOULD PREFER TO SEE A STRONGER N-S SURFACE PRESSURE
GRADIENT BEFORE PUTTING TOO MUCH WIND INLAND.
THE PRECIPITATION WILL TURN TO SHOWERS BEHIND THE FRONT MONDAY NIGHT
AND TUESDAY AS COLDER AIR MOVES IN. SNOW LEVELS WILL DROP DOWN TO
AROUND 1000 FEET TUESDAY MORNING...BUT SNOW ACCUMULATIONS AT THE
LOWER ELEVATIONS SHOULD BE MINIMAL.
.LONG TERM...MADE NO CHANGES...PREVIOUS DISCUSSION FOLLOWS...IT
CONTINUES TO LOOK LIKE COOL AND WET WEATHER WILL DOMINATE THE
EXTENDED FCST PERIOD. A STRONG UPPER LEVEL JET AND LONGWAVE TROUGHING
PATTERN WILL REMAIN OVER THE EASTERN PAC AT LEAST
THROUGH NEXT WEEKEND. MODEL AGREEMENT IS FAIRLY GOOD THAT WARM
FRONTAL RAIN ALONG WITH GUSTY COASTAL WINDS WILL SPREAD INTO THE
FCST AREA DURING THE SECOND HALF OF WED. AN APPROACHING SHORTWAVE
WILL BRING EVEN WETTER CONDITIONS ON THU. SNOW LEVELS WILL REMAIN
FAIRLY HIGH ON WED AND THU...WITH SIGNIFICANT SNOWFALL ACCUMULATIONS
CONFINED TO THE HIGHER ELEVATIONS OF THE CASCADES. HEADING INTO NEXT
WEEKEND...THE EXTENDED MODELS CONTINUE TO SUGGEST THAT THE UPPER
LEVEL TROUGHING WILL DIG FURTHER SOUTH...WITH THE BULK OF THE ENERGY
FOCUSED IN NORTHERN CALIFORNIA. THIS WOULD LEAVE US IN A SHOWERY
PATTERN WITH SNOW LEVELS DOWN INTO THE COAST RANGE AND CASCADE
FOOTHILLS. JFP
&&
.AVIATION...MVFR CONDITIONS WILL CONTINUE THIS EVENING BUT CIGS AND
VISIBILITY WILL BEGIN TO LOWER ON THE COAST AFTER MIDNIGHT AS A
WARM FRONT APPROACHES. CIGS WILL LOWER TO FR ALONG THE COAST
AROUND 12Z AS THE WARM FRONT PASSES WITH STRONG SOUTH WINDS. WINDS
WILL REMAIN STRONG IN THE WARM SECTOR UNTIL THE COLD FRONT PASSES.
EXPECT THE COLD FRONT TO REACH ASTORIA AROUND 19Z AND TO NEWPORT
AROUND 12Z. INLAND WINDS WILL INCREASE AROUND 12Z ESPECIALLY ALOFT
STRONG WINDS IN THE LOWER LEVELS AFTER 12Z MON...GENERALLY BELOW
900 MB...WILL LIKELY RESULT IN LOW-LEVEL WIND SHEAR...MAINLY SPEED
SHEAR OF +/- 15 KT OR MORE..AT MOST OF THE TAF SITES.
KPDX AND APPROACHES...EXPECT PRIMARILY VFR THROUGH AT LEAST 12Z
MON. LOW- LEVEL WIND INCREASES AFTER 12Z MON...FOR A THREAT OF
LOW-LEVEL WIND SHEAR (SPEED SHEAR) OF AT LEAST +/- 15 KT. EXPECT
CIGS TO REMAIN VFR UNTIL AFTERNOON WHEN CIGS WILL LOWER AS THE
FRONT APPROACHES.
&&
.MARINE...WINDS THIS EVENING HAVE BEEN VERY GUSTY WITH SHOWERS AND
ARE A BIT STRONGER THAN PREVIOUS FORECAST. THE NEW MODELS REMAIN
CONSTANT IN SHOWING SOLID STORM FORCE WINDS WITH THE DEVELOPING
LOW AND FRONT EARLY MONDAY MORNING. THE HRRR MODEL SHOWS HURRICANE
FORCE GUSTS UP TO 75KT OVER THE COASTAL WATERS...BUT SINCE THIS
GUIDANCE IS RELATIVELY NEW I HAVE CHOSEN TO STICK WITH A HIGH END
STORM WARNING. WE WILL NEED TO WATCH CLOSELY HOW THE LOW DEVELOPS.
THESE BOMB SYSTEMS ARE CAPABLE OF BEING DEEPER THAN THE MODELS
FORECAST. MODELS..SHOW STORM FORCE WIND HANGING ON LONGER OVER THE
FAR SOUTHERN WATERS MON AFTERNOON. HAD SOME CONCERNS THAT WE COULD
GET SOME ADDITIONAL STRONG WIND ON THE BACK SIDE OF THE LOW OVER THE
WASHINGTON WATERS...BUT AT THIS TIME MOST MODELS KEEP THE POISONOUS
TAIL OF THE BENT BACK OCCLUSION HEADED TO OUR NORTH.
AFTER THE MON SYSTEM...IT LOOKS LIKE ANOTHER FAIRLY STRONG
DISTURBANCE MOVES THROUGH THE WATERS WED. NAM AND GFS HAVE BACKED
OFF AND SLOWED IT DOWN...MORE INTO WED AFTERNOON. THE ECMWF STILL
BRINGS SOLID GALES TO THE WATERS LATE TUE NIGHT THROUGH WED
MORNING.
SEAS ALREADY IN THE 15 TO 16 FT RANGE WILL CONTINUE TO BUILD
RAPIDLY OVERNIGHT. WITH 12 HOURS OF STORM TO NEAR HURRICANE FORCE
WINDS I AM ADJUSTING THE SEA HEIGHTS UP IN THE FORECAST. THIS WILL
BE MORE IN LINE WITH OUR SWAN MODEL FORECAST WHICH IS BETTER WITH
THESE SYSTEMS THAT DEVELOP RAPIDLY NEAR THE COAST THAN THE
WAVEWATCH III MODEL. EXPECT TO SEE 28 TO 32 FOOT SEAS IN THE WATERS
TOMORROW...IN THE NORTH DURING THE MORNING AND IN THE SOUTH DURING
THE AFTERNOON. THE MAJORITY OF THE ENERGY WILL BE WITH THE SHORTER
PERIOD 12 SECOND WAVES. ALTHOUGH THE DIRECTION WILL BE FROM THE
SOUTHWEST WE ARE STILL AT THE LOW END FOR A HIGH SURF WARNING. THE
TIDAL ANOMALIES HAVE BEEN RUNNING 1 TO 2 FEET AND EXPECT THIS TO
REACH 3 FT TOMORROW MORNING. WITH THE HIGH TIDES AROUND 10Z TO 12Z
WE COULD HAVE COASTAL FLOODING IF THE SEAS WERE HIGH ENOUGH.
HOWEVER THE TIMING OF THE HIGHEST SWELL IS EXPECTED TO BE WHEN THE
TIDE IS FALLING AND DURING LOW TIDE. DURING THE SECOND HIGH TIDE
SHOULD NOT BE HIGH ENOUGH TO PRODUCE COASTAL FLOODING. SO FOR NOW
WE WILL NOT ISSUED A COASTAL FLOOD WARNING. SEAS WILL REMAIN ABOVE
20 FEET THROUGH LATE MONDAY AFTERNOON...THEN FALL OFF OVERNIGHT
MONDAY.
SCHNEIDER
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING FROM 2 AM TO 5 PM PDT MONDAY FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
HIGH SURF WARNING FROM 5 AM TO 11 PM PDT MONDAY FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
WINTER WEATHER ADVISORY FROM 3 PM MONDAY TO 7 AM PDT TUESDAY
FOR NORTHERN OREGON CASCADES.
WINTER WEATHER ADVISORY FROM 1 AM TO 11 AM PDT TUESDAY FOR
CASCADES IN LANE COUNTY.
WA...HIGH WIND WARNING FROM 2 AM TO 5 PM PDT MONDAY FOR SOUTH
WASHINGTON COAST.
HIGH SURF WARNING FROM 5 AM TO 11 PM PDT MONDAY FOR SOUTH
WASHINGTON COAST.
WINTER WEATHER ADVISORY FROM 7 AM MONDAY TO 5 AM PDT TUESDAY
FOR SOUTH WASHINGTON CASCADES.
PZ...HURRICANE FORCE WIND WARNING UNTIL 1 PM PDT MONDAY FOR COASTAL
WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM.
HURRICANE FORCE WIND WARNING UNTIL 6 PM PDT MONDAY FOR COASTAL
WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 PM
PDT MONDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1151 PM CDT SUN MAR 11 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY
255 PM CDT SUN MAR 11 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION TONIGHT INTO MONDAY AS
WELL AS THE ABOVE NORMAL TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED AN UPPER TROUGH FROM THE NORTHEAST PACIFIC INTO THE PACIFIC
NORTHWEST...THEN ZONAL FLOW FROM MANITOBA EAST INTO QUEBEC. IN THE
SOUTHERN STREAM...AN UPPER LOW WAS OVER THE OKLAHOMA PANHANDLE WITH
RIDGING BUILDING DOWNSTREAM INTO THE UPPER MISSISSIPPI RIVER VALLEY
REGION. AHEAD OF THE UPPER LOW...SHOWERS AND EMBEDDED THUNDERSTORMS
EXTENDED FROM FAR SOUTHWEST IOWA INTO KANSAS...MISSOURI AND SOUTH TO
THE GULF COAST. THE PRECIPITATION WAS BEING FORCED FROM A NUMBER OF
FACTORS: DPVA AHEAD OF THE UPPER LOW THE BIG ONE...A STREAM OF LOW
LEVEL MOISTURE TRANSPORT NOTED BY 30-40 KT 925-850MB WINDS ON
PROFILER DATA...INSTABILITY PRODUCED BY DAYTIME HEATING ACTING WITH
THE UPPER LOW AND SURFACE DEWPOINTS CLIMBING INTO THE 40S AND 50S.
PRECIPITABLE WATER VALUES IN THE MOISTURE STREAM ARE 1-1.5 INCHES OR
200-270 PERCENT OF NORMAL PER 12Z RAOBS. OVER THE FORECAST
AREA...DRY AIR ON THE 12Z MPX AND DVN SOUNDINGS HAVE KEPT ANY CLOUD
COVERAGE AHEAD OF THE PRECIPITATION LIMITED TO CIRRUS AND MID-LEVEL
CLOUDS THUS FAR...AND THESE ARE JUST COMING INTO LOCATIONS ALONG AND
SOUTH OF I-90. WITH PLENTY OF SUN...850MB TEMPS BETWEEN 8-10C PER
12Z RAOB ANALYSIS AND A RELATIVELY BREEZY SOUTH WIND...TEMPERATURES
HAVE CLIMBED AGAIN INTO THE 60S TODAY.
TONIGHT AND MONDAY...UPPER LOW OVER THE CENTRAL PLAINS IS FORECAST
TO LIFT NORTHEAST...CROSSING THE AREA SHORTLY AFTER 12Z MONDAY...
THEN REACH LAKE SUPERIOR BY 00Z TUESDAY. THIS EJECTION IS IN
RESPONSE TO THE TROUGHING CURRENTLY OVER THE PACIFIC NORTHWEST
LIFTING INTO MANITOBA. PRETTY IMPRESSIVE 500MB HEIGHT FALLS PROGGED
TONIGHT INTO MONDAY MORNING...ANYWHERE BETWEEN 150 AND 200 METERS.
SO NEEDLESS TO SAY THE DYNAMIC FORCING IS REALLY STRONG. A STRONG
SURGE OF MOISTURE COMES UP AHEAD OF THE LOW...SEEN IN PRECIPITABLE
WATER PROGS OF AROUND 1 INCH OR 300 PERCENT OF NORMAL. THEREFORE...
THE DYNAMICS SHOULD HAVE NO PROBLEM BRINGING PRECIPITATION TO THE
AREA. DESPITE THE ABOVE NORMAL MOISTURE...NOT ANTICIPATING THIS TO
BE A HEAVY QPF EVENT FOR A NUMBER OF REASONS: THE HIGH AMOUNT OF
MOISTURE DOES NOT STICK AROUND LONG DUE TO THE UPPER LOW MOVING
QUICKLY...MUCAPE FROM THE NAM FOR MUCH OF THIS TIME PERIOD STAYS
BELOW 200 J/KG LIMITING THUNDERSTORMS TO ISOLATED AT BEST...NO UPPER
JET SUPPORT AND BEST 850MB MOISTURE TRANSPORT AIMED EAST OF HERE.
WHAT INSTABILITY DOES EXIST IS OVER WISCONSIN DURING THE DAY
MONDAY...THUS HAVE KEPT A SLIGHT CHANCE FOR THUNDER THEN. REGARDING
PRECIPITATION TRENDS IN THE FORECAST...SHOULD SEE SHOWERS MOVE IN
THIS EVENING OVER MUCH OF THE FORECAST AREA...THEN BECOME MORE
SCATTERED ON MONDAY AS THE UPPER LOW PULLS AWAY BUT ITS COLD POOL
ALOFT LINGERS. TEMPERATURES ARE LIKELY TO REMAIN MILD TONIGHT WITH
CLOUDS AND HIGHER DEWPOINTS MOVING IN. LITTLE CHANGE REQUIRED FOR
LOWS. HIGHS ON MONDAY ARE TRICKY GIVEN THAT ONLY SUN POTENTIAL WOULD
OCCUR IN THE AFTERNOON AND SOUTH OF I-90. FOR NOW STUCK WITH A BLEND
OF GUIDANCE...BUT IF CLOUDS STAY AROUND LONGER THAN FORECAST...HIGHS
MAY NEED TO BE COOLED.
MONDAY NIGHT THROUGH WEDNESDAY...UPPER LOW IS PROGGED TO MOVE
FURTHER AWAY FROM THE REGION WHILE A FEW NEW TROUGHS DROP DOWN INTO
THE PACIFIC NORTHWEST AND EJECT UP INTO CENTRAL CANADA. THE RESPONSE
OF ALL OF THIS IS TO BUILD RIDGING OVER THE UPPER MISSISSIPPI RIVER
VALLEY REGION...SENDING A SURGE OF WARMER AIR INTO THE FORECAST
AREA. 850MB TEMPS WHICH START OFF AT 4-8C AT 12Z TUESDAY ARE
FORECAST TO CLIMB TO 8-12C BY 00Z WEDNESDAY AND TO 12-14C FOR THE
WHOLE DAYTIME HOURS ON WEDNESDAY. THERE ARE EVEN SOME HINTS OF 16C
850MB TEMPS APPROACHING THE WESTERN PORTION OF THE FORECAST AREA ON
WEDNESDAY...AHEAD OF A DYING SURFACE COLD FRONT COMING INTO
MINNESOTA. THESE 850MB READINGS ARE 2-2.5 STANDARD DEVIATIONS ABOVE
NORMAL...FAVORING TEMPERATURES APPROACHING OR EXCEEDING RECORD HIGHS
GIVEN TOO THAT PLENTY OF SUN SHOULD OCCUR BOTH DAYS. LEANED TOWARDS
THE HIGH END OF ALL GUIDANCE AS A RESULT FOR HIGHS. SOME
PRECIPITATION NOTES. THE 11.12Z NAM SHOWS ELEVATED CONVECTION
BETWEEN 09-15Z WEDNESDAY OVER EASTERN IOWA AND FAR SOUTHWEST
WISCONSIN. THIS PRECIPITATION FORMS DUE TO THE PRESENCE OF A WEAK
SHORTWAVE...A WARM FRONT AND ELEVATED CAPE VALUES BETWEEN 1000-1500
J/KG. HOWEVER...THE 850MB DEWPOINT HELPING TO PRODUCE THIS CAPE IS
AROUND 10C...OR 8C HIGHER THAN THE ECMWF. THE GFS IS ALSO SLIGHTLY
LOWER. THEREFORE AM DISCOUNTING THE NAM AT THE PRESENT TIME. ON
WEDNESDAY...THE GFS SEEMS TO HAVE TOO MUCH MOISTURE AT AND BELOW
900MB...A KNOWN PROBLEM SEEN IN SOME RECENT WARM EVENTS...AND THUS
STRATUS AND DRIZZLE OUT. DISCOUNTING THIS SCENARIO AS WELL SINCE IT
DOES NOT AGREE WITH THE ECMWF/NAM/CANADIAN. LASTLY...ON WEDNESDAY
AFTERNOON THE NAM CONVECTS OVER EASTERN IOWA AND SOUTHERN
WISCONSIN...THOUGH THERE IS NO SURFACE TRIGGER. IN ADDITION...THE
MODEL BRINGS SURFACE DEWPOINTS INTO THE 60S WHICH SEEMS WAY TOO
HIGH. AS SUCH...HAVE FOLLOWED THE DRY ECMWF/CANADIAN SCENARIO.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
255 PM CDT SUN MAR 11 2012
GOOD MODEL AGREEMENT EXISTS THAT THE FLOW OF TROUGHS COMING INTO THE
PACIFIC NORTHWEST THEN LIFTING INTO NORTH CENTRAL CANADA PERSISTS
THROUGH THURSDAY NIGHT. THEN ON FRIDAY AND HEADING INTO THE
WEEKEND...ALL MODELS SHOW A REALLY DEEP TROUGH FORMING ALONG THE
WEST COAST OF THE U.S. THE 11.12Z GFS IS BY FAR THE MOST PROGRESSIVE
WITH A STRONG SHORTWAVE COMING OUT OF THIS TROUGH...RESULTING IN A
FRONT MOVING THROUGH THE AREA AT 12Z SUNDAY. THE 11.00Z/12Z ECMWF
AND 11.12Z CANADIAN KEEPS THIS SHORTWAVE WRAPPED IN THE TROUGH WHICH
SEEMS MORE REASONABLE. BASICALLY ALL THIS MEANS IS THAT THE FORECAST
AREA STAYS UNDER UPPER RIDGING AND IN THE WARM SECTOR. THERE IS ONE
POTENTIAL CAVEAT TO THE WARM SECTOR WHICH IS THE COLD FRONT FROM
WEDNESDAY OVER MINNESOTA. MODELS PROG THIS FRONT TO DIE AS IT COMES
INTO THE FORECAST AREA WEDNESDAY NIGHT AND THURSDAY...WHILE BECOMING
ORIENTED MORE WEST-EAST WITH THE UPPER FLOW. AT THIS TIME HAVE
MAINTAINED A CONSENSUS 20 PERCENT CHANCES FOR PRECIPITATION ON THUS
FRONT OVER SOUTHWEST WISCONSIN WEDNESDAY NIGHT...THEN IN NORTHEAST
IOWA ON THURSDAY. STILL...THINKING MUCH OF THIS PERIOD WILL END UP
DRY. AFTER THIS...IT BECOMES A LITTLE MORE DIFFICULT TO PINPOINT
WHEN PRECIPITATION OCCURS. AS THE UPPER LEVEL FLOW AMPLIFIES...THERE
ARE INDICATIONS OF A FEW SHORTWAVES RIDING THROUGH DURING THE FRIDAY
THROUGH SATURDAY NIGHT TIME PERIOD. DEPENDING ON THE MODEL THE
TIMING VARIES. FOR NOW HAVE STAYED WITH A CONSENSUS APPROACH WHICH
RESULTS IN MUCH OF THE FORECAST AREA HAVING 20-40 PERCENT CHANCES.
STRONGER UPPER RIDGING ON SUNDAY SHOULD PREVENT ANY PRECIPITATION.
THE MAIN STORY CONTINUES TO BE THE WARMTH. 850MB TEMPS ON AVERAGE
HOLD BETWEEN 10-14C...OR 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL.
THIS SHOULD HELP TO KEEP HIGH TEMPERATURES MOSTLY IN THE 70S AND
NEAR OR ABOVE RECORDS. PERHAPS THE ONLY EXCEPTION TO THIS MIGHT BE
ON THURSDAY OVER NORTH CENTRAL WISCONSIN ON THE NORTH SIDE OF THAT
DYING COLD FRONT. ALSO OF NOTE IS THAT LOW TEMPERATURES ARE GOING TO
BE VERY WARM FOR THIS TIME OF YEAR TOO...AIDED BY DEWPOINTS HOLDING
MAINLY IN THE 50S. IN FACT...LOWS COULD BE 10-15 DEGREES ABOVE
NORMAL HIGHS.
&&
.AVIATION...THROUGH 06Z TUESDAY
1151 PM CDT SUN MAR 11 2012
500MB LOW NOW OVER SOUTHERN NEBRASKA AND WILL CONTINUE TO LIFT
NORTHWARD OVERNIGHT AND BY IN NORTHWEST WISCONSIN BY 18Z MONDAY.
RAIN WAS SPREADING NORTHWARD OUT OF IOWA INTO SOUTHERN MINNESOTA
AND WILL OVERSPREAD THE TAF SITES BY ISSUANCE TIME. EXPECT
CEILINGS TO DROP INTO IFR CATEGORY AND REMAIN THERE THROUGH AT
LEAST 15Z-17Z. CEILINGS WILL THEN RISE INTO THE MVFR CATEGORY AS
THE LOW LIFTS AWAY FROM THE AREA. LIGHT RAIN SHOWERS LOOK TO
PERSIST THROUGH MUCH OF THE DAY...ENDING BY MID TO LATE AFTERNOON.
SURFACE RIDGE THEN BEGINS TO BUILD INTO THE REGION FROM THE WEST.
THIS WILL CLEAR SKIES OUT BETWEEN 03Z-0-6Z AT THE TAF SITES.
&&
.CLIMATE...
255 PM CDT SUN MAR 11 2012
RECORD HIGHS HAVE BEEN BROKEN AT KLSE AND KRST...JUST BARELY WITH
ONLY BEING 1 DEGREE ABOVE THEM...BUT RECORDS NONETHELESS. POTENTIAL
STILL EXISTS FOR A DEGREE OR TWO RISE SO RECORD EVENT REPORTS WILL
BE HELD UNTIL DAYTIME HEATING ENDS AROUND 5 PM.
BEING NEAR OR AT RECORDS FOR HIGHS WILL BE THE NORM HERE STARTING
TUESDAY AND LASTING PERHAPS INTO EARLY NEXT WEEK. AN ANOMALOUS WARM
PATTERN IS SETTING UP OVER THE FORECAST AREA. LOW TEMPERATURES COULD
EVEN BE HIGH ENOUGH THAT WE SET NEW RECORD HIGH MINIMUMS. SEE OUR
WEBSITE FOR DETAILS ON RECORD HIGHS.
&&
.HYDROLOGY...THROUGH MONDAY
255 PM CDT SUN MAR 11 2012
NOT MUCH IN THE WAY OF ANY CHANGES TO THE GOING FORECAST. SNOWPACK
IN TAYLOR COUNTY IS IN FULL MELT MODE NOW / PER NOHRSC SNOW PACK
TEMPERATURE ANALYSIS / AND WILL CONTINUE TO MELT DURING THE NEXT
COUPLE OF DAYS. FORECAST RAINFALL AMOUNTS ARE STILL IN THE 0.35 TO
0.60 INCH RANGE WHICH WILL LIKELY LEAD TO SOME RISES ALONG THE
BLACK AND TREMPEALEAU RIVERS...BUT STILL NOT UP TO FLOOD STAGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
255 PM CDT SUN MAR 11 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
CLIMATE...AJ
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1023 AM CDT MON MAR 12 2012
.DISCUSSION...
ISSUED 1020 AM CDT MON MAR 12 2012
UPDATED THE FORECAST TODAY TO INCREASE CHANCES OF SHOWERS AND
ADDED ISOLATED THUNDERSTORMS LATE THIS MORNING AROUND GALESBURG
IN KNOX COUNTY. ALSO INCREASED WIND SPEEDS A BIT TODAY AS SOUTH
WINDS 15 TO 25 MPH AND GUSTS AROUND 35 MPH TURN SW DURING THE
AFTERNOON. ANOTHER MINOR ADJUSTMENT TO THE FORECAST WAS TO EXPAND
THE SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON A
BIT FURTHER SOUTH (TO JUST SOUTH OF I-74).
FAIRLY STRONG 543 DM 500 MB LOW WAS DEEPENING OVER THE EASTERN
MN/IA BORDER AS IT WAS TRACKING NE. AS THE SURFACE A STRONG 990 MB
LOW PRESSURE WAS ALONG THE NORTHERN ALBERTA/SASKATCHEWAN PROVINCE
LINE WITH A FRONTAL BOUNDARY EXTENDING SOUTHWARD ACROSS THE
CENTRAL PLAINS OVER CENTRAL NE/KS INTO NW TX. 1032 MB HIGH
PRESSURE WAS OFF THE EAST COAST. BREEZY SOUTH WINDS OF 15 TO 25
MPH AND GUSTS TO AROUND 30 MPH OVER CENTRAL IL BETWEEN THESE
WEATHER FEATURES. THIS HAD BROUGHT IN MILD AND MOIST AIR INTO IL
WITH DEWPOINTS IN THE MID TO UPPER 50S AND TEMPS AT 10 AM IN THE
LOWER 60S. RADAR MOSAIC SHOWS A STRENGTHENING BAND OF SHOWERS WITH
A FEW EMBEDDED THUNDERSTORMS IN NW IL NORTH OF GALESBURG INTO EAST
CENTRAL IA AND SOUTHERN WI AND MOVING NE.
12Z MODELS TAKE UPPER LEVEL LOW PRESSURE NE INTO WESTERN LAKE
SUPERIOR BY SUNSET WHILE THE FRONTAL BOUNDARY IN THE CENTRAL
PLAINS WEAKENS AS IT DRIFTS EASTWARD TOWARD THE MS VALLEY. INSTABILITY
INCREASES ACROSS EASTERN IL THIS AFTERNOON WITH CAPES INCREASING
TO 1000-1500 J/KG BY 21Z/4 PM EAST OF I-55. UPPER LEVEL DYNAMICS
PASS ACROSS NORTHERN IL SO BEST CHANCES OF SHOWERS AND
THUNDERSTORMS WILL BE OVER NE IL AROUND CHICAGO METRO. SPC HAS A
SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON FROM PONTIAC NE
WITH GENERAL RISK OF THUNDERSTORM SW TO ALONG I-74 CORRIDOR.
ISOLATED SHOWERS AND THUNDERSTORMS EXPECTED THIS AFTERNOON ALONG
AND NE OF I-74 AND A FEW STORMS COULD BECOME STRONG WITH HAIL AND
GUSTY WINDS. SPC HAS 2% RISK OF TORNADOES AND 5% RISK OF LARGE
HAIL AND DAMAGING WIND GUSTS NE OF BLOOMINGTON AND DANVILLE THIS
AFTERNOON. TEMPS TO CLIMB ANOTHER 10 DEGREES INTO THE LOWER TO
MIDDLE 70S AS MOSTLY CLOUDY SKIES BECOME PARTLY TO MOSTLY SUNNY
THIS AFTERNOON.
HUETTL
&&
.AVIATION...
ISSUED 530 AM CDT MON MAR 12 2012
UPPER LOW SHIFTING NE THRU WEST CENTRAL IA EARLY THIS MORNING HAS
SPREAD MVFR AND ISOLD IFR CIGS ACRS THE FORECAST AREA ALONG WITH
ISOLD SHOWERS. LOOKS LIKE AREAS ALONG THE ILLINOIS RIVER VALLEY
AND WEST STAND THE BEST CHANCE FOR SEEING ADDL RAINFALL THIS MRNG
BUT COVERAGE HAS DIMINISHED FROM EARLIER SO WILL JUST ADD VCSH
RATHER THAN TEMPO A GROUP FOR ANY PROLONGED PERIOD OF RAINFALL.
SHOULD SEE SOME DRY AIR WORK ITS WAY INTO THE SOUTHERN PORTIONS
OF THE TAF AREA THIS MRNG WITH MVFR CIGS COMMON ACRS THE NORTH
INTO THIS AFTERNOON. WEAK FRONTAL BOUNDARY WILL THEN SHIFT SE
ACRS THE AREA AFTR 21Z WITH THE POTENTIAL FOR ISOLD TSRA ALONG
IT...BUT COVERAGE WILL BE TOO LIMITED TO MENTION IN TAFS OTHER
THAN A CB GROUP IN PIA...BMI AND CMI IN THE 22Z-02Z TIME FRAME.
FRONTAL BOUNDARY SHOULD THEN SHIFT EAST OF THE TAF SITES AFTR 04Z
WITH VFR CONDITIONS EXPECTED UNTIL LATE TONIGHT WHEN SOME GROUND
FOG MAY DEVELOP IN THE 09Z-12Z TIME FRAME. WILL ADD 4-5SM IN FOG
LATE IN THE FORECAST PERIOD TO COVER THIS POTENTIAL. SFC WINDS
WILL BE GUSTY TODAY OUT OF THE SOUTH TO SOUTHWEST WITH PREVAILING
SPEEDS OF 12 TO 17 KTS...AND GUSTS IN THE 25 TO 30 KT RANGE LATE
THIS MRNG INTO THIS AFTN. WINDS SHOULD VEER MORE INTO A WESTERLY
DIRECTION LATE THIS AFTN AND EVENING AND THEN BEGIN TO DIMINISH
AFTR DARK.
SMITH
&&
.PREV DISCUSSION...
ISSUED 227 AM CDT MON MAR 12 2012
UPPER LOW CLEARLY EVIDENT IN INFRARED AND WATER VAPOR SATELLITE
IMAGERY...CENTERED OVER EASTERN NEBRASKA. DRY SLOT HAS PUSHED
ACROSS MUCH OF THE CWA...REDUCING THE RAIN TO SCATTERED SHOWERS.
THE EXTENT OF THE LINGERING RAIN IS THE INITIAL FORECAST CONCERN...
BUT THE PRIMARY FOCUS IS THE EXTENDED PERIOD OF ABNORMALLY WARM
WEATHER FOR MID MARCH.
SHORT TERM...TODAY THROUGH WEDNESDAY...
00Z MODELS ARE IN GOOD AGREEMENT WITH TRACKING THE LOW INTO WEST
CENTRAL WISCONSIN BY LATE MORNING...THEN TO THE UPPER PENINSULA OF
MICHIGAN BY EARLY EVENING. LINGERING SHOWERS ACROSS THE EASTERN
CWA SHOULD BE OUT OF THE AREA BY MID TO LATE MORNING. NORTHERN CWA
IS A BIT MORE QUESTIONABLE...AS NAM AND HRRR BOTH SHOWING SOME
INSTABILITY SHOWERS REFORMING IN THE COLDER AIR ALOFT. BOTH MODELS
SHOWING THE BEST RAIN CHANCES IN OUR NORTHERN CWA IN THE MORNING...
BUT WILL LINGER SOME SLIGHT CHANCES THERE INTO THE AFTERNOON AS
WELL.
UPPER RIDGING ACROSS THE CENTRAL U.S. BEGINS IN EARNEST LATER
TONIGHT AND PERSISTS MUCH OF THE WEEK. START OF THE WARMING TREND
BEGINS TODAY AND BY WEDNESDAY...WE WILL LIKELY BE SEEING 80 DEGREE
TEMPERATURES IN SEVERAL LOCATIONS. MOST RECORD HIGHS ON WEDNESDAY
ARE IN THE 74-78 RANGE...WITH SOME LOWER 80S ACROSS THE
SOUTHEAST...SO WILL LIKELY SEE SEVERAL RECORDS FALL. MODELS ARE
SOMEWHAT INCONSISTENT WITH SHOWER/THUNDERSTORM POTENTIAL ON
WEDNESDAY WITH THE RIDGE IN PLACE...BUT RAIN CHANCES INCREASE
WEDNESDAY NIGHT AS A WEAKENING BOUNDARY DROPS INTO THE AREA.
LONG TERM...THURSDAY THROUGH SUNDAY...
850 MB TEMPERATURES REMAIN CLOSE TO +12C THROUGH THE PERIOD...AS
THE UPPER RIDGE GRADUALLY SHIFTS TO THE EAST COAST. HOWEVER...CLOUD
COVER WILL BE MORE OF A FACTOR...AS WEAK WAVES IN THE UPPER FLOW
BRING PERIODIC CHANCES OF SHOWERS AND STORMS. HAVE KEPT HIGHS WELL
INTO THE 70S THROUGH THE PERIOD...BUT HAVE NOT GONE AS AGGRESSIVE
AS WEDNESDAY DUE TO THIS ISSUE.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
536 AM CDT MON MAR 12 2012
.DISCUSSION...
ISSUED 227 AM CDT MON MAR 12 2012
UPPER LOW CLEARLY EVIDENT IN INFRARED AND WATER VAPOR SATELLITE
IMAGERY...CENTERED OVER EASTERN NEBRASKA. DRY SLOT HAS PUSHED
ACROSS MUCH OF THE CWA...REDUCING THE RAIN TO SCATTERED SHOWERS.
THE EXTENT OF THE LINGERING RAIN IS THE INITIAL FORECAST CONCERN...
BUT THE PRIMARY FOCUS IS THE EXTENDED PERIOD OF ABNORMALLY WARM
WEATHER FOR MID MARCH.
SHORT TERM...TODAY THROUGH WEDNESDAY...
00Z MODELS ARE IN GOOD AGREEMENT WITH TRACKING THE LOW INTO WEST
CENTRAL WISCONSIN BY LATE MORNING...THEN TO THE UPPER PENINSULA OF
MICHIGAN BY EARLY EVENING. LINGERING SHOWERS ACROSS THE EASTERN
CWA SHOULD BE OUT OF THE AREA BY MID TO LATE MORNING. NORTHERN CWA
IS A BIT MORE QUESTIONABLE...AS NAM AND HRRR BOTH SHOWING SOME
INSTABILITY SHOWERS REFORMING IN THE COLDER AIR ALOFT. BOTH MODELS
SHOWING THE BEST RAIN CHANCES IN OUR NORTHERN CWA IN THE MORNING...
BUT WILL LINGER SOME SLIGHT CHANCES THERE INTO THE AFTERNOON AS
WELL.
UPPER RIDGING ACROSS THE CENTRAL U.S. BEGINS IN EARNEST LATER
TONIGHT AND PERSISTS MUCH OF THE WEEK. START OF THE WARMING TREND
BEGINS TODAY AND BY WEDNESDAY...WE WILL LIKELY BE SEEING 80 DEGREE
TEMPERATURES IN SEVERAL LOCATIONS. MOST RECORD HIGHS ON WEDNESDAY
ARE IN THE 74-78 RANGE...WITH SOME LOWER 80S ACROSS THE
SOUTHEAST...SO WILL LIKELY SEE SEVERAL RECORDS FALL. MODELS ARE
SOMEWHAT INCONSISTENT WITH SHOWER/THUNDERSTORM POTENTIAL ON
WEDNESDAY WITH THE RIDGE IN PLACE...BUT RAIN CHANCES INCREASE
WEDNESDAY NIGHT AS A WEAKENING BOUNDARY DROPS INTO THE AREA.
LONG TERM...THURSDAY THROUGH SUNDAY...
850 MB TEMPERATURES REMAIN CLOSE TO +12C THROUGH THE PERIOD...AS
THE UPPER RIDGE GRADUALLY SHIFTS TO THE EAST COAST. HOWEVER...CLOUD
COVER WILL BE MORE OF A FACTOR...AS WEAK WAVES IN THE UPPER FLOW
BRING PERIODIC CHANCES OF SHOWERS AND STORMS. HAVE KEPT HIGHS WELL
INTO THE 70S THROUGH THE PERIOD...BUT HAVE NOT GONE AS AGGRESSIVE
AS WEDNESDAY DUE TO THIS ISSUE.
GEELHART
&&
.AVIATION...
ISSUED 530 AM CDT MON MAR 12 2012
UPPER LOW SHIFTING NE THRU WEST CENTRAL IA EARLY THIS MORNING HAS
SPREAD MVFR AND ISOLD IFR CIGS ACRS THE FORECAST AREA ALONG WITH
ISOLD SHOWERS. LOOKS LIKE AREAS ALONG THE ILLINOIS RIVER VALLEY
AND WEST STAND THE BEST CHANCE FOR SEEING ADDL RAINFALL THIS MRNG
BUT COVERAGE HAS DIMINISHED FROM EARLIER SO WILL JUST ADD VCSH
RATHER THAN TEMPO A GROUP FOR ANY PROLONGED PERIOD OF RAINFALL.
SHOULD SEE SOME DRY AIR WORK ITS WAY INTO THE SOUTHERN PORTIONS
OF THE TAF AREA THIS MRNG WITH MVFR CIGS COMMON ACRS THE NORTH
INTO THIS AFTERNOON. WEAK FRONTAL BOUNDARY WILL THEN SHIFT SE
ACRS THE AREA AFTR 21Z WITH THE POTENTIAL FOR ISOLD TSRA ALONG
IT...BUT COVERAGE WILL BE TOO LIMITED TO MENTION IN TAFS OTHER
THAN A CB GROUP IN PIA...BMI AND CMI IN THE 22Z-02Z TIME FRAME.
FRONTAL BOUNDARY SHOULD THEN SHIFT EAST OF THE TAF SITES AFTR 04Z
WITH VFR CONDITIONS EXPECTED UNTIL LATE TONIGHT WHEN SOME GROUND
FOG MAY DEVELOP IN THE 09Z-12Z TIME FRAME. WILL ADD 4-5SM IN FOG
LATE IN THE FORECAST PERIOD TO COVER THIS POTENTIAL. SFC WINDS
WILL BE GUSTY TODAY OUT OF THE SOUTH TO SOUTHWEST WITH PREVAILING
SPEEDS OF 12 TO 17 KTS...AND GUSTS IN THE 25 TO 30 KT RANGE LATE
THIS MRNG INTO THIS AFTN. WINDS SHOULD VEER MORE INTO A WESTERLY
DIRECTION LATE THIS AFTN AND EVENING AND THEN BEGIN TO DIMINISH
AFTR DARK.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1045 AM EDT MON MAR 12 2012
.UPDATE...
ZONES UPDATED TO REMOVE EARLY MORNING WORDING AND WIND DOWN SHOWER
MENTION.
BULK OF PRECIP HAS SHIFTED NE OF THE AREA. A NARROW BAND OF
SHOWERS WAS LOCATED ON THE LEADING EDGE OF AT LEAST PARTIAL
CLEARING. THIS WILL QUICKLY TRAVERSE THE REMAINDER OF THE AREA AND
EXIT BY 17Z. FOCUS THEN SHIFTS TO THE WEST IN PROXIMITY OF THE
UPPER LOW. LIMITED CLEARING WAS ALREADY UNDERWAY ACROSS PORTIONS
OF CENTRAL ILLINOIS. VIS SAT SHOWING HINTS OF SOME TOWERING CU
DEVELOPMENT JUST EAST OF LINCOLN ILLINOIS. AS TEMPS CONTINUE TO
WARM AND DEWPTS CLIMB INTO THE MID AND UPPER 50S...STAGE WILL BE
SET FOR AT LEAST SCT STORM DEVELOPMENT. NARROW LINE OF CONVECTION
ALREADY FIRING ON EASTERN FRINGE OF COLD AIR ASSOCIATED WITH UPPER
LOW WITH A FEW LIGHTNING STRIKES NOTED. 11Z HRRR KEYS IN ON THIS
AREA WITH EVENTUAL DEVELOPMENT OF AFTERNOON/EVENING CONVECTION
LIKELY INITIATING ON THIS FEATURE. 12Z SWODY1 EXPANDED THE SLGT
RISK ACROSS MOST OF THE FORECAST AREA AND INCREASED PROBS FOR
DAMAGING WINDS. WILL CONTINUE TO MONITOR TRENDS THROUGH EARLY
AFTERNOON FOR CHANGES TO ZONES...INCLUDING POSSIBLE INCLUSION OF
SVR MENTION.
&&
.PREV DISCUSSION... /ISSUED 811 AM EDT MON MAR 12 2012/
AVIATION /12 UTC TAFS/...
WARM FNTL RAIN BAND MOVG NE OF THE AREA THIS MORNING BUT LEAVING
MVFR CIGS IN ITS WAKE. 55KT LLJ OVER INDIANA EARLY THIS MORNING
CONTS THREAT OF SGFNT LLWS. MIDDAY BREAKOUT WITH STRONG HEATING AS
DRY SLOT ENVELOPES NRN IN AND SW WINDS INCREASE WITH GUSTS INTO
UPPER 20S...PERHAPS SETTING STAGE FOR ERLY EVENING CONVECTION
POTNL...ADDED TSGS AT SBN WITH JUST CONTD CB MENTION AT FWA WHERE
CAPPING STILL VERY PSBL.
PREV DISCUSSION
SHORT TERM...
TODAY THROUGH TUESDAY NIGHT. HIGHLY CONDITIONAL FCST WRT CONVECTION
IN SHORT TERM WEIGHS NEGATIVELY ON OVERALL CONFIDENCE. OVERALL NOD
TOWARD NAM IN CAPTURING STRENGTH OF UPSTREAM MIDLVL CIRCULATION/CYCL
CURVED JETLET TO LIFT NEWD FM SERN KS/SWRN MO THIS AM. INITIAL WARM
CONVEYOR BELT RAFL IN STABLE ENVIRON SANS MUCAPE AND GIVEN SHALLOW
OBSERVED 88-D TOPS/POOR IR SIGNAL HAVE SQUELCHED TSRA MENTION THIS
AM. PD OF WDSPRD MVFR STRATOCU IN ORPHANED LLVL MSTR FOR SVRL HOURS
BEFORE MIX OUT INTO DRY SLOT AFFORDS RAPID INSOLATION RESPONSE. MAX
SFC HEATING/DESTABILIZATION ACRS NERN IL/NWRN IN BY LATE AFTN
COINCIDENT WITH PEAK OF SFC DPS SHOULD NOSE INTO MID 50S TO YIELD
MLCAPE AROUND 1000-1250 J/KG PER MODIFIED 21-00 UTC SNDGS ACRS NWRN
CWA. INCREASED CIN/WARM 8-7H WARM LYR SHOULD INHIBIT TSRA CHCS WITH
S/SERN EXTENT THROUGH CWA. UPDRAFT INITIATION LKLY TO PROGRESS BOTH
UPSTREAM AND TO LEE OF SRN LK MI INVOF LK INDUCED THERMAL
CIRCULATIONS/MESOSCALE BOUNDARY INTERACTIONS IN HIGH SHEAR
ENVIRONMENT WITH 50-55KT 0-6KM DEEP LYR SHEAR NWRN CWA TRAILING TO
40 KTS SOUTH. WILL ADDRESS SEVERE POTNL WITH WIND/HAIL AND SIG
LESSER EXTENT TOR IN HWO AND AWAIT INCRSD CONFIDENCE IN
STORM/UPDRAFT MORPHOLOGY TIED TO FINER DETAILS AND CONDITIONAL WRT
ADEQUATE INSTABILITY. STRONGEST HEATING/TIMING OF DRY SLOT MIXOUT
SHOULD BE AFFORDED ACRS NERN IL INTO WRN CWA SUPPORTIVE OF INCRSD
SFC BASED LAPSE RATES NOSING INTO SRN EDGE OF COLD CORE 5H CLOSED
LOW...THOUGH QUITE FARTHER AWAY THAN PREFERRED TORNADIC CONCEPTUAL
MODEL PER DAVIES. LOW WETBULB ZERO HGHTS 7.5-8.5 KFT TO PROVE
EFFICIENT FOR HAIL PRODUCTION/ALBEIT LKLY SMALL DIAMETER. BEST
CONVECTIVE POTNL/HIEST POPS NW STRADDLING EVENING/ERLY TONIGHT
PERIOD IN MORE FAVORABLE SHEAR/INSTABILITY OVERLAP WITH LAKE
BOUNDARY INFLUENCES. CHCS THEN DWINDLE ONCE DOWNSTREAM INSTABILITY
WANES WITH INCRSD DIURNAL COOLING AS SYSTEM CONTS NEWD INTO LK
SUPR/SRN CAN WHILE UNDERGOING PHASING INTO ACCELERATING SRN CAN/NEG
TILT TROF TONIGHT INTO ERLY TUES. THEREAFTER QUITE BENIGN AND WARM
PATTERN WITH UNSEASONABLY HIGH BELTED FLOW/STRONG RIDGING SFC/ALOFT
BUILDING INTO GRTLKS WITH STRONG INSOLATION/DEEP MIXING TO LKLY
OVERCOME ANY BRIEF SHALLOW COOLER AIR INTRUSION FOR SIMILAR MAX
TEMPS ON TUE...W/EXCEPTION OF LAKE SHADOW/ONSHORE COMPONENT FLOW
DY2...TO WHICH WAS REMOVED DY1 GIVEN TDYS DEEP SRLY FLOW.
LONG TERM...
WEDNESDAY THROUGH SUNDAY...A LONG WAVE TROF WILL REMAIN ENTRENCHED
ALONG THE WESTERN NORTH AMERICAN COAST THROUGH THIS PERIOD. THIS
TROF WILL CAUSE LARGE SCALE AMPLIFICATION DOWNSTREAM OVER THE
CENTRAL AND EASTERN CONUS WITH UNSEASONABLY WARM CONDITIONS THROUGH
THE ENTIRE PERIOD. THE CHALLENGE REMAINS WITH TIMING OF INDIVIDUAL
SHORT WAVES IN THE LARGE SCALE PATTERN AS GULF MOISTURE SPREADS
NORTH AND NORTHEAST ACROSS THE OHIO RIVER AND PERSISTS THROUGH THE
PERIOD. FOR THIS PACKAGE...WENT WITH A GENERAL GFS AND CANADIAN
ENSEMBLE BLEND AND USED DAILY FREQUENCIES OF THE PAST CLIMATOLOGICAL
RECORD. MADE JUST MINOR CHANGES TO SHOWER/STORM CHANCES. TEMPERED
HIGHS SOME BUT ESPECIALLY TEMPERED LOWS TO COME BETTER IN LINE WITH
CLIMATOLOGY. LOWS OF 55F OR HIGHER AT FWA FROM MARCH 14 TO 18 HAVE
ONLY OCCURRED TWICE IN THE LAST 110 YEARS. KEPT THUNDER THROUGH MOST
OF THE WEDNESDAY NIGHT THROUGH SATURDAY PERIOD. WIND FLOW SHOULD
STAY RELATIVELY WEAK...BUT MOISTURE WILL PERSIST WITH FAIRLY STEEP
LAPSE RATES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ043-046.
&&
$$
SHORT TERM...MURPHY
LONG TERM...SKIPPER
AVIATION...MURPHY/JT
UPDATE...FISHER
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
628 AM EDT MON MAR 12 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
RAIN WILL MOVE EAST OF THE REGION BY MIDDAY AS AN UPPER LEVEL
DISTURBANCES TRACKS TO NEAR LAKE SUPERIOR. ISOLATED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE THOUGH INTO TONIGHT AS A WEAK
FRONTAL BOUNDARY PASSES THROUGH THE LOWER GREAT LAKES. HIGH PRESSURE
WILL THEN BUILD IN THROUGH MIDWEEK BRINGING DRY AND UNSEASONABLY
WARM WEATHER. CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN BEGINNING
WEDNESDAY NIGHT AND CONTINUING INTO THE WEEKEND AS A FRONTAL
BOUNDARY BECOMES NEARLY STATIONARY ACROSS THE REGION.
&&
.NEAR TERM /TODAY/...
RAIN CURRENTLY EXPANDING ACROSS CENTRAL INDIANA EARLY THIS MORNING.
LOW LEVEL DRY AIR HAS BEEN A SIGNIFICANT IMPEDIMENT TO RAINFALL
COVERAGE AND INTENSITY SO FAR. TEMPS WERE IN THE MID AND UPPER 50S
AS OF 07Z.
HAVE TRENDED TOWARDS THE HRRR WITH RESPECT TO PRECIPITATION TIMING
AND COVERAGE THROUGH MID MORNING AS IT APPEARS TO BE CAPTURING
CURRENT ACTIVITY WELL. AS MENTIONED ABOVE...DRY AIR THROUGH THE
BOUNDARY LAYER HAS REALLY CUT DOWN THE COVERAGE TO RAINFALL FROM
WHAT HAD BEEN PREVIOUSLY THOUGHT. DEWPOINTS AT 07Z REMAIN IN THE 30S
OVER EASTERN COUNTIES WITH QUICK RISES INTO THE 40S AND LOWER 50S
FURTHER WEST AS LOWER LEVELS SATURATE. MOST WIDESPREAD RAINFALL
COVERAGE WILL BE EXPERIENCED THROUGH 12Z WITH STRONGEST ISENTROPIC
LIFT ONGOING AND LOW LEVEL JET TRAVERSING THROUGH THE AREA. WILL
MAINTAIN CATEGORICAL POPS THROUGH DAYBREAK...BUT OVERALL QPF VALUES
WILL BE UNDER 0.25 INCHES. WILL MAINTAIN AN ISOLATED THUNDER MENTION
AS WELL BASED ON SUBTLE LEVELS OF INSTABILITY AND SAID FORCING ALOFT
PRESENT.
MUCH OF THE RAIN WILL SHIFT EAST OF THE FORECAST AREA THROUGH MID
MORNING AS DRIER PUNCH OF AIR SURGES INTO THE REGION FROM THE
SOUTHWEST. WILL HOLD ONTO HIGHEST POPS OVER EASTERN COUNTIES THROUGH
ABOUT 15Z DIMINISHING TO CHANCE OR LOWER THEREAFTER. AS DRIER AIR
PRESSES INTO CENTRAL INDIANA...MODEL SOUNDINGS INDICATE LOW LEVEL
MOISTURE WILL BECOME TRAPPED UNDERNEATH A BOUNDARY LAYER INVERSION.
THIS WOULD SUGGEST STRATOCU LIKELY TO BE SLOW TO DEPART TODAY...
WITH ANY SUNSHINE HOLDING OFF UNTIL THE AFTERNOON AS THE LOWER
LEVELS BEGIN MIXING OUT. ARRIVAL OF A SECOND LOW LEVEL JET THIS
AFTERNOON COMBINED WITH STRATOCU MIXING OUT WILL SET THE STAGE FOR
GUSTY WINDS POSSIBLY TO 30 TO 35 MPH DURING THE AFTERNOON. HAVE HELD
ONTO LOW CHANCE POPS OVER EASTERN COUNTIES THIS AFTERNOON WITH WEAK
INSTABILITY AND LINGERING LOW LEVEL MOISTURE PRESENT. LACK OF
APPRECIABLE FORCING ALOFT HOWEVER SHOULD KEEP ANY CONVECTION THAT
DEVELOPS ISOLATED AT BEST.
TEMPS...LOW LEVEL THERMALS WILL CLIMB FURTHER TODAY WITH THE STRONG
SOUTHWEST FLOW INTO THE OHIO VALLEY. DESPITE THE PRESENCE OF CLOUDS
INTO THE AFTERNOON...MANY LOCATIONS LIKELY TO MAKE IT TO THE 70
DEGREE MARK FOR THE FIRST TIME THIS YEAR. TRENDED A DEGREE OR TWO
ABOVE GUIDANCE IN MOST AREAS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON TEMPS AS SPRING PREVIEW ARRIVES TO
CENTRAL INDIANA THIS WEEK.
UPPER LOW WILL TRACK THROUGH THE NORTHERN GREAT LAKES TONIGHT WITH A
WEAK SURFACE BOUNDARY PASSING THROUGH THE LOWER GREAT LAKES
OVERNIGHT. EXPECTED CONVECTIVE DEVELOPMENT ACROSS MICHIGAN AND
NORTHERN INDIANA WHERE FORCING ALOFT AND AVAILABLE INSTABILITY WILL
BE GREATER MAY CLIP FAR NORTHERN COUNTIES AND HAVE HELD ONTO
ISOLATED POPS IN THESE AREAS. HOWEVER WITH SHALLOW MOISTURE PROFILES
NOTED ON MODEL SOUNDINGS...BOUNDARY MORE LIKELY TO PASS THROUGH THE
FORECAST AREA UNEVENTFULLY.
SURFACE HIGH PRESSURE EXPANDS INTO THE REGION TUESDAY WITH RIDGING
ALOFT. ANY LINGERING LOWER CLOUDS TUESDAY MORNING WILL DIMINISH AS
INCREASING SUBSIDENCE ABOVE THE BOUNDARY LAYER EXPANDS ACROSS THE
OHIO VALLEY. AS THE HIGH DRIFTS EAST BY WEDNESDAY NIGHT...DEVELOPING
S/SW FLOW THROUGH THE LOW LEVELS WILL BRING INCREASINGLY MOIST AIR
NORTH OUT OF THE GULF OF MEXICO. DESPITE LITTLE IF ANY FORCING ALOFT
WEDNESDAY NIGHT...ISOLATED TO SCATTERED CONVECTIVE DEVELOPMENT IS
EXPECTED AS THE INCREASING MOISTURE AND INSTABILITY INTERACT WITH AN
APPROACHING WEAK FRONTAL BOUNDARY. WILL CARRY 30 POPS OVERNIGHT
WEDNESDAY.
TEMPS...UNSEASONABLY WARM TEMPERATURES THROUGH THE PERIOD AS LOW
LEVEL THERMALS CONTINUE TO RISE WITH 850MB TEMPS APPROACHING 13C AND
15-16C AT 925MB BY WEDNESDAY. HAVE GONE AT OR ABOVE MAVMOS GUIDANCE
BOTH TUESDAY AND WEDNESDAY WITH 70S EXPECTED. HIGH TEMPERATURES MAY
APPROACH NEAR RECORD HIGHS ON WEDNESDAY AND NOT OUT OF THE QUESTION
AT THIS POINT THAT WESTERN COUNTIES FLIRT WITH 80 DEGREES. MOS
GUIDANCE LOOKED REASONABLE FOR LOWS THROUGH THE PERIOD. JUST THE
BEGINNING OF WHAT APPEARS TO BE AN EXTENDED PERIOD OF WELL ABOVE
NORMAL TEMPS FOR CENTRAL INDIANA.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ENSEMBLES SUGGEST UPPER PATTERN WILL BECOME HIGHLY AMPLIFIED
DURING THIS PERIOD. STRONG RIDGING IS EXPECTED TO DEVELOP OVER THE
EASTERN PARTS OF THE COUNTRY...WHILE A DEEP TROUGH WILL DEVELOP OVER
THE WEST COAST. ENSEMBLES SUGGEST AN UPPER DISTURBANCE MAY BE MOVING
THROUGH THE NORTHERN GREAT LAKES AROUND THURSDAY. TOWARDS NEXT
WEEKEND...IT APPEARS THAT A BROAD SOUTHWESTERLY UPPER FLOW WILL
DEVELOP OVER THE LOCAL AREA AHEAD OF WESTERN TROUGH. THIS WILL
RESULT IN THE POSSIBILITY OF EMBEDDED DISTURBANCES EJECTING OUT OF
THE TROUGH...WITH ENSEMBLES SUGGESTING A PRECIPITATION THREAT PRETTY
MUCH ALL THROUGH THE EXTENDED PERIOD. WILL KEEP POPS GOING FROM
THURSDAY THROUGH SATURDAY. INHERITED A DRY FORECAST FOR NEXT
SUNDAY...BUT SOME OF ENSEMBLE MEMBERS AND OPERATIONAL MODELS SUGGEST
AN UNSTABLE AIR MASS AND RESULTANT PRECIPITATION THREAT AT THAT TIME.
WILL CONTINUE TO KEEP SUNDAY DRY FOR NOW...BUT POPS MAY NEED TO BE
ADDED AT A LATER TIME IF TRENDS LEAN TOWARDS A WETTER SOLUTION.
&&
.AVIATION /DISCUSSION FOR THE 121200Z TAFS/...
RADAR TRENDS AND SHORT RANGE MODEL DATA SUGGEST THE MAIN RAIN THREAT
WILL PASS EAST OF KIND/KBMG AROUND 121300Z. OTHERWISE...EXTENSIVE
AREA OF MVFR CEILINGS 015-025 UPSTREAM. MOST OF THESE LOWER CEILINGS
SHOULD MIX OUT BY THE EARLY TO MID AFTERNOON HOURS...ALTHOUGH MODEL
DATA INDICATE THERE MAY BE A PERSISTENT INVERSION AROUND 035 THIS
AFTERNOON. THIS MAY RESULT IN THE MVFR CEILINGS MIXING OUT INTO A
BROKEN DECK AROUND 035 RATHER THAN DISSIPATING COMPLETELY.
POTENTIAL FOR CONVECTIVE DEVELOPMENT MID TO LATE AFTERNOON ACROSS
NORTHERN ILLINOIS OR NORTHWEST INDIANA ALONG AN APPROACHING FRONT.
APPEARS IF ANYTHING DOES DEVELOP...IT SHOULD REMAIN NORTHWEST OF
KLAF...AT LEAST THROUGH 130000Z.
MODEL WIND PROGS INDICATE GOOD POTENTIAL FOR SURFACE WIND GUSTS
25-28KTS FROM 200-220 DEGREES THIS AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...JAS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1047 AM CDT MON MAR 12 2012
.UPDATE...
THE OVERALL FCST HAS BEEN UPDATED TO BETTER REFLECT CURRENT
CONDITIONS. THE RUC SHOWS A NARROW AREA OF F VECTOR CONVERGENCE
FROM ABOUT KBRL TO KDKB WHICH WAS ALSO ALONG A THETA E GRADIENT IN
THE 850-300MB LAYER. THESE FEATURES EXPLAIN THE NARROW BAND OF
CONVECTION WITH A FEW TSRA ASSOCIATED WITH IT. THE REMAINDER OF
THE STRATIFORM RAIN CAN BE EXPLAINED WITH CONVERGENCE IN THE
800-750MB LAYER.
RUC TRENDS SHOW THE CURRENT PRECIP EXITING THE AREA LATE THIS
MORNING. WATER VAPOR INDICATES A VORT MAX ACROSS NORTHERN MISSOURI
THAT WILL ROTATE OVER THE SOUTHEAST HALF OF THE CWFA DURING THE
AFTERNOON HOURS. LIFT TOOL SHOWS STRONG CONVERGENCE DEVELOPING
WITH ANOTHER THETA E GRADIENT ROTATING INTO THE CWFA AS THE COLD
POCKET ALOFT MOVES EAST. THUS SHOWERS SHOULD BE MOST PREVALENT
OVER THE SOUTHEAST HALF OF THE CWFA WITH LOWER CHANCES OVER THE
NORTHWEST HALF OF THE CWFA. FCST SOUNDINGS FROM THE RUC SUGGEST
THAT TSRA WILL BE ALSO POSSIBLE OVER ROUGHLY THE SOUTHEAST HALF OF
THE CWFA AND BASED ON THE PROGGED WBZ HEIGHTS SMALL HAIL MAY BE
POSSIBLE WITH THE STRONGER CELLS.
...08..
&&
.AVIATION... /ISSUED 721 AM CDT MON MAR 12 2012/
VFR CONDS SOUTH OF I-80 WITH IFR CONDS TO THE NORTH THIS MORNING.
SCATTERED SHOWERS ALL AREAS THIS MORNING THEN SCATTERED
THUNDERSTORMS THIS AFTERNOON ESPECIALLY NORTH OF INTERSTATE 80.
MVFR CIGS/VIS IN SHOWERS. HIGH PRESSURE RIDGE BRINGS SKC TONIGHT
AND TUESDAY. SOUTH TO SOUTHWEST WINDS 10 TO 20 KNOTS WITH GUSTS TO
25 KNOTS TODAY. NORTHWEST WINDS LESS THAN 10 KNOTS TONIGHT. WINDS
BECOMING SOUTHEAST LESS THAN 10 KNOTS ON TUESDAY.
&&
PREV DISCUSSION... /ISSUED 320 AM CDT MON MAR 12 2012/
SYNOPSIS...
AS EXPECTED WIDESPREAD RAIN IN THE MOIST CONVEYOR BELT MOVED
THROUGH THE DVN CWA DURING THE NIGHT AND HAS FOR THE MOST PART
LIFTED TO THE NORTHEAST OF THE CWA EARLY THIS MORNING. DOPPLER
RADAR ESTIMATES RAINFALL IN THE 1/4 TO 1/2 INCH RANGE WEST OF THE
MS RIVER WITH LESSER AMOUNTS TO THE EAST. OTHERWISE THE UPPER LOW
WAS SPINNING ACROSS WESTERN IA WITH AN AREA OF SHOWERS INTO
CENTRAL IA. THERE WAS ALSO A TRAILING VORT MAX OVER NORTHWEST MO
AND WAS LIFTING TO THE NORTHEAST...AND WAS ALSO PRODUCING SHOWERS.
INCREDIBLY MILD AND MOIST FOR THIS TIME OF NIGHT IN THE MIDDLE OF
MARCH. CURRENT SURFACE DEWPOINTS IN THE CWA WERE IN THE UPPER 40S
TO LOWER 50S WITH TEMPERATURES MAINLY IN THE LOWER TO MID 50S.
HAASE..
SHORT TERM...TODAY AND TONIGHT...
FORECAST FOCUS ON THUNDERSTORM POTENTIAL ESPECIALLY THIS
AFTERNOON...THEN CLEAR AND COOLER TONIGHT.
TODAY...WILL START OUT THE DAY WITH LOW CLOUDS AND SCATTERED
SHOWERS. HOWEVER BY AFTERNOON ENOUGH BREAKS IN THE CLOUDS TO HAVE
A MIX OF CLOUDS AND SUNSHINE TO BOOST TEMPERATURES INTO THE MID
60S NORTH TO LOWER 70S SOUTH. THE COMBINATION OF THE UPPER LOW AND
COLD POCKET LIFTING ACROSS NORTHERN IA AND INTO WISCONSIN TODAY...
AND A TRAILING VORT MAX COMING OUT OF NW MO SHOULD TRIGGER ADDITIONAL
SCATTERED SHOWERS AND EVEN A FEW THUNDERSTORMS. THE BEST COVERAGE
WILL BE IN OUR NORTHERN CWA AND WILL HAVE AT LEAST 50 POPS. WILL
NEED TO KEEP AN EYE ON THUNDERSTORM POTENTIAL THIS AFTERNOON AS
THE VORT MAX LIFTS ACROSS THE CWA IN CONCERT WITH DAYTIME HEATING.
STEEP LAPSE RATES...MODERATE TO STRONG SHEAR WILL BE IN PLACE BUT
CAPES ARE MARGINAL AND A SURFACE LOW IS LACKING TO FOCUS SURFACE
CONVERGENCE. NONETHELESS FREEZING LEVELS OF LESS THAN 8K FT ARE
IDEAL FOR SMALL HAIL AND ANY ROTATING STORM MAY BE ABLE TO PRODUCE
ISOLATED DAMAGING WIND. SPC HAS A SLIGHT RISK FOR SEVERE STORMS
EAST OF THE DVN CWA FROM NORTHEAST IL INTO LOWER MI FOR MAINLY
THIS AFTERNOON. THE VORT MAX SHOULD LIFT AWAY FROM THE DVN CWA BY
LATE AFTERNOON IF NOT SOONER ENDING THE THUNDERSTORM THREAT.
TONIGHT...HIGH PRESSURE RIDGE WITH CLEAR SKIES AND LIGHT WINDS
OVER THE REGION. WITH LOWERING DEWPOINTS MINIMUM TEMPERATURES
SHOULD BOTTOM OUT IN THE UPPER 30S TO MID 40S.
HAASE..
LONG TERM...TUESDAY THROUGH SUNDAY...
THE FORECAST OF A LONG PERIOD OF VERY WARM...POSSIBLY RECORD LEVEL
WARMTH CONTINUES TO BE EXPECTED THROUGHOUT THE ENTIRE EXTENDED
FORECAST...AND BEYOND. A VERY SUMMER-LIKE AIRMASS SHOULD SET UP
TUESDAY...WITH A WEAK FRONTAL CONVERGENCE INTO THE CWA FROM
WEDNESDAY AFTERNOON THROUGH SATURDAY OR SUNDAY. THIS WEAK
CONVERGENCE WILL COMBINE WITH THE EXTREMELY MILD AND MOIST AIRMASS
TO PROVIDE A DAILY THREAT FOR SHOWERS AND STORMS...ALBEIT VERY LOW
DAILY CONFIDENCE IN THEM. I.E. SUMMER-LIKE.
DESPITE SURFACE HIGH PRESSURE AND LIGHT WINDS TUESDAY...THE SUN AND
VERY MILD AIR ALOFT SHOULD AID GETTING MIXING HEIGHTS HIGH ENOUGH TO
TAP INTO THE MILD AIR. THUS...WIDESPREAD UPPER 60S TO MID 70S ARE
FORECAST. WEDNESDAY WILL SEE BETTER MIXING YET...AND MID 70S TO NEAR
80 IS RIGHT ON TRACK FOR NOW...ESPECIALLY SINCE CLOUDS DO NOT LOOK
OPAQUE UNTIL LATE AFTERNOON...WHEN A FEW STORMS COULD FORM ALONG THE
WEAK FRONT.
THIS WEAK FORCING CONTINUES THROUGH THE END OF THE WEEK...WITH VERY
SIMILAR DAYTIME TEMPERATURES UNLESS ORGANIZED STORMS CAN FORM. WITH
SUCH LOW CONFIDENCE IN CONVECTION...OUR TEMPERATURE ARE FORECAST
BELOW THE SUNNY POTENTIAL...BUT WELL ABOVE THE LEVELS IF STORMS
OCCUR IN ANY PERIOD.
LOOKING SLIGHTLY BEYOND...THE UPPER PATTERN BECOMES MORE VOLATILE
WITH VERY FAST WINDS ALOFT AND STRONG FORCING WITH TIME...AND OUR
AIRMASS WILL LIKELY BECOME MORE MOIST AND WARM. THIS COMBINATION
COULD BRING OUR FIRST SEVERE WEATHER TO THE DVN CWA BY EARLY NEXT
WEEK.
ERVIN..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
926 AM CDT MON MAR 12 2012
...UPDATE TO REMOVE DENSE FOG...
.UPDATE...
ISSUED AT 920 AM CDT MON MAR 12 2012
THE 11-3.9 MICRON SATELLITE IMAGERY AS WELL AS LOCAL METAR
OBSERVATIONS INDICATED THAT THE DENSE FOG ACROSS THE FAR
SOUTHEAST COUNTIES HAD DISSIPATED RAPIDLY THIS MORNING. THE DENSE
FOG ADVISORY WAS CANCELED EARLY. NO OTHER IMMEDIATE SHORT TERM
CHANGES ARE ANTICIPATED AS FIRE WEATHER ISSUES FOR TUESDAY ARE
BEING EVALUATED.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM CDT MON MAR 12 2012
UPPER-LEVEL TROUGHING WILL PERSIST THROUGH MARCH 18TH ACROSS THE FAR
WESTERN UNITED STATES, THEN SLOWLY PROGRESS EASTWARD AND AMPLIFY
JUST TO OUR WEST BY MARCH 19-20TH. GIVEN THE EXPECTED POSITIONING OF
THIS TROUGH OVER THE FAR WESTERN UNITED STATES BY MID-WEEK,
SOUTHWESTERLY MID-LEVEL FLOW WILL BE PRESENT ACROSS THE ROCKIES AND
OVER THE PLAINS. LEE TROUGHING WILL DEVELOP IN RESPONSE TO THE FLOW
ACROSS THE ROCKIES, AND THIS WILL SERVE TO DRAW RICH LOW-LEVEL
MOISTURE NORTHWARD INTO THE SOUTHERN PLAINS. THE SURFACE DRYLINE
WILL MARK THE INTERFACE BETWEEN THE MOIST AIRMASS OVER THE PLAINS
AND THE DRY AIRMASS OVER THE WESTERN HIGH PLAINS AND ROCKIES. IT
WILL BE WARM EVERY DAY THROUGH THE WEEKEND WITH HIGHS IN THE 70S AND
80S AND LOWS FROM THE UPPER 40S WEST TO 55 TO 62 IN SOUTH CENTRAL
KANSAS. OFTENTIMES IN RETURN FLOW SITUATIONS IN MARCH, PREVIOUS COLD
FRONTAL PASSAGES THROUGH THE GULF AND EVEN INTO THE CARIBBEAN RESULT
IN ONLY MODEST MOISTURE RETURNS INTO THE PLAINS. THIS WILL NOT BE
THE CASE THIS WEEK SINCE THE GULF SEA SURFACE IS NEARLY AT
EQUILIBRIUM WITH THE AIR IMMEDIATELY ABOVE. GULF BUOY DATA INDICATE
DEWPOINTS AROUND 70F IN THE CENTRAL GULF CURRENTLY, WHICH IS VERY
IMPRESSIVE FOR THIS TIME OF YEAR. KEEP IN MIND THAT JUST BECAUSE 70F
DEWPOINTS ARE PRESENT IN THE CENTRAL GULF DOESN`T MEAN THAT WE CAN
EXPECT DEWPOINTS THAT HIGH IN SOUTHWEST KANSAS LATER THIS WEEK.
WHEN MOIST, MARINE AIR MOVES NORTHWARD INTO THE PLAINS, DEEP
VERTICAL MIXING OCCURS, WHICH CAUSES THE MOIST LAYER TO BE DEEPER,
BUT NOT QUITE AS RICH. ALSO, DODGE CITY IS 2600FT ABOVE SEA LEVEL
AND THIS INCREASED ELEVATION WILL RESULT IN SOME REDUCTION IN
DEWPOINT AS WELL AS THE MOISTURE MOVES ONTO THE HIGHER TERRAIN. SO
IT IS MORE REASONABLE TO EXPECT DEWPOINT TEMPERATURES FROM THE MID
50S TO THE MID 60S (13-18C) AHEAD OF THE DRYLINE.
BY WEDNESDAY AFTERNOON, THE SURFACE DRYLINE WILL STRETCH FROM A
WEAK SURFACE LOW AND FRONT OVER SOUTHWEST KANSAS SOUTH-SOUTHWESTWARD
INTO THE TEXAS PANHANDLE. A SUBTROPICAL JET STREAK WILL BE SITUATED
ACROSS THE TEXAS PANHANDLE. SURFACE BASED CAPE VALUES WILL APPROACH
2000 J/KG BY LATE AFTERNOON FROM DODGE CITY SOUTH AND EAST. THERE
MAY BE ENOUGH CONVERGENCE ALONG THE DRYLINE AND NEAR THE FRONT-
DRYLINE INTERSECTION, ALONG WITH STRONG ELEVATED HEATING, TO YIELD
ISOLATED THUNDERSTORMS. ANY STORMS THAT DEVELOP COULD BE SEVERE WITH
LARGE HAIL.
ISOLATED THUNDERSTORMS CANNOT BE RULED ANY DAY THROUGH MARCH 20TH AS THE
SURFACE DRYLINE REMAINS OVER WESTERN KANSAS. THE ECMWF INDICATES
THAT THE BEST CHANCES MAY BE SATURDAY FROM DODGE CITY SOUTHEASTWARD,
AND THEN AGAIN BY MONDAY AND TUESDAY AS THE UPPER-LEVEL TROUGH AND
ASSOCIATED MID-LEVEL COOLING APPROACH WESTERN KANSAS. ANY STORMS
THAT DEVELOP IN THESE PERIODS COULD BE SEVERE, ALTHOUGH THE BEST
CHANCE OF HIGH-END SEVERE STORMS WITH TORNADOES SHOULD BE LATER
MONDAY OR TUESDAY AS THE MID TO HIGH-LEVEL WINDS BECOME MUCH
STRONGER IN ADVANCE OF THE UPPER-LEVEL TROUGH. OF COURSE, A LOT
COULD CHANGE BETWEEN NOW AND MARCH 19TH-20TH; AND IT IS IMPOSSIBLE
TO SAY AT THIS POINT EXACTLY WHERE IN THE PLAINS THE BEST CHANCE
OF THUNDERSTORMS WILL BE.
KEEP IN MIND THAT DUE TO THE VERY WARM EXPECTED TEMPERATURES, RECORD
HIGH NIGHTTIME AND DAYTIME TEMPERATURES ARE POSSIBLE ACROSS WESTERN
KANSAS LATER THIS WEEK AND THIS WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 600 AM CDT MON MAR 12 2012
VFR CONDITIONS WILL PREVAIL. A WEAK TROUGH OF LOW PRESSURE WILL BE SITUATED
THROUGH THE CENTRAL PLAINS TODAY. WINDS WILL SHIFT TO THE NORTHWEST
BEHIND THIS TROUGH BY MIDDAY. THE PRESSURE GRADIENT WILL WEAKEN BY
LATE AFTERNOON RESULTING IN LIGHT WINDS BY THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 402 AM CDT MON MAR 12 2012
FIRE WEATHER WILL BE A CONCERN ON TUESDAY. AFTERNOON VERTICAL
MIXING WILL RESULT IN RELATIVE HUMIDITIES FROM 10 TO 15 PERCENT
ALONG WITH FREQUENT WIND GUSTS NEAR OR JUST IN EXCESS OF 25 MPH.
A FIRE WEATHER WATCH IS IN EFFECT ALONG AND WEST OF A LINE FROM
MEADE TO DIGHTON. THIS WAS NOT UPGRADED SINCE THERE IS SOME
QUESTION AS TO WHETHER SURFACE WINDS WILL BE STRONG ENOUGH. ALSO
ELLIS AND TREGO COUNTIES MAY NEED TO BE ADDED.
AFTER A LESSENING OF THE PRESSURE GRADIENT WEDNESDAY AND THURSDAY,
FIRE WEATHER WILL BE A CONCERN EVERY DAY FROM FRIDAY THROUGH SUNDAY,
ESPECIALLY IN FAR WESTERN KANSAS BEHIND THE SURFACE DRYLINE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 77 41 83 46 / 0 0 0 0
GCK 76 39 82 42 / 0 0 0 0
EHA 75 38 82 41 / 0 0 0 0
LBL 76 39 81 42 / 0 0 0 0
HYS 78 42 82 46 / 0 0 0 0
P28 78 44 81 53 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
&&
$$
UPDATE...RUSSELL
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS TOPEKA KS
621 AM CDT MON MAR 12 2012
...AVIATION UPDATE...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
LATEST RUC AND NAM FORECAST SOUNDINGS SHOW THE BOUNDARY LAYER
REMAINING CAPPED WITH LOW LEVEL MOISTURE TRAPPED THROUGH ABOUT
16Z. WITH SATELLITE SHOWING A BROAD AREA OF STRATUS...WILL HANG
ONTO MVFR CIGS FOR TOP AND FOE A LITTLE LONGER THAN PREV FORECAST.
THERE ARE ACTUALLY SOME IFR AND LIFR CIGS JUST WEST OF MHK WHICH
COULD MOVE IN. THINK THE CLEAR SKIES CURRENTLY BEING REPORTED WILL
BE TEMPORARY UNTIL THE BOUNDARY LAYER MIXES OUT AROUND 16Z. ONCE
THE LOW LEVEL MOISTURE IS SCOURED OUT...LARGE SCALE SUBSIDENCE
SHOULD LEAD TO VFR CONDITIONS.
WOLTERS
&&
.FIRE WEATHER... /ISSUED 335 AM CDT MON MAR 12 2012/
TODAY WITH THE WARM AFTERNOON TEMPERATURES AND DEWPOINTS IN THE
MIDDLE 30S TO NEAR 40...THE RANGELAND FIRE DANGER INDEX WILL REACH
THE VERY HIGH CATEGORY FOR MUCH OF THE AREA. OF GREATEST CONCERN
WILL BE NORTH CENTRAL KANSAS...WITH MINIMUM RELATIVE HUMIDITY
VALUES IN THE 22 TO 26 PERCENT RANGE. THE PRESSURE GRADIENT
RELAXES BY EARLY AFTERNOON...WITH WIND SPEEDS DECREASING DURING
THE AFTERNOON HOURS. ADDITIONALLY...MANY LOCATIONS RECEIVED
PRECIPITATION ON SUNDAY. THESE MITIGATING FACTORS MAY HELP KEEP
FIRE WEATHER ISSUES SOMEWHAT IN CHECK. ON TUESDAY...A GRADUAL
INCREASE IN LOW LEVEL MOISTURE SHOULD KEEP CONDITIONS BELOW RED
FLAG CRITERIA...EVEN WITH SURFACE TEMPERATURES NEARING 80 DEGREES.
BLAIR
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT MON MAR 12 2012/
TODAY/TONIGHT...CENTER OF UPPER LOW CURRENTLY LOCATED OVER
SOUTHEAST NEBRASKA WILL CONTINUE ITS QUICK NORTHEASTWARD EXIT FROM
THE AREA THIS MORNING. THE LAST REMAINING PRECIPITATION AREA
REMAINS IN A FRONTOGENETICAL REGION OVER NORTH CENTRAL KANSAS.
WITH ITS CURRENT TRAJECTORY AND SOME WEAKENING ON THE SOUTHERN
END...HAVE INTRODUCED A SLIGHT CHANCE OF SHOWERS TO CONTINUE FROM
12Z THROUGH 15Z OVER THE FAR NORTHEASTERN CWA. ALL PRECIPITATION
WILL END ACROSS THE CWA BY 15Z...WITH RAPIDLY CLEARING SKIES FROM
SOUTHWEST TO NORTHEAST. TEMPERATURES WILL QUICKLY INCREASE BY
MID/LATE MORNING BEHIND THE DEPARTING SYSTEM...WITH READINGS
REACHING THE LOWER TO MIDDLE 70S DURING THE AFTERNOON. WINDS WILL
BECOME LIGHT TONIGHT WITH LITTLE INCREASE IN LOW LEVEL MOISTURE
OVERNIGHT. LOWS WILL FALL INTO THE MIDDLE 40S IN MOST LOCATIONS.
SEE FIRE WEATHER DISCUSSION BELOW FOR ADDITIONAL FORECAST DETAILS
FOR TODAY.
TUESDAY THROUGH SUNDAY...RELATIVELY PERSISTENT PATTERN EXPECTED OVER
THE PERIOD WITH THE UPPER JET RETREATING NORTHWARD AS UPPER RIDGING
DOMINATES THE CENTRAL CONUS. WEAK TO MODERATE SOUTHWEST FLOW ALOFT
WILL SPREAD OVER THE CENTRAL PLAINS...WITH OPERATIONAL MODELS
SUGGESTING OCCASIONAL WEAK DISTURBANCES TRAVERSING THE AREA. AT THE
SURFACE...A DRYLINE WILL RESIDE OVER OR JUST WEST OF THE CWA THROUGH
THE PERIOD...PLACING THE FORECAST AREA IN A WARM...MOIST AND
UNSTABLE AIRMASS. SLIGHT CHANCES OF THUNDERSTORMS WILL BE POSSIBLE
EACH DAY...WITH SPECIFIC TIMING BETTER RESOLVED AS UPPER FEATURES
AND MESOSCALE PROCESSES BECOME IDENTIFIED. TEMPERATURES WILL BE WELL
ABOVE NORMAL...CLOSER TO READINGS FOR EARLY/MID MAY...WITH HIGHS IN
THE MIDDLE 70S TO LOWER 80S. WITH DEWPOINTS INCREASING TO THE MIDDLE
50S TO LOWER 60S...LOWS WILL ONLY FALL INTO THE 50S EACH NIGHT.
BLAIR
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
603 AM CDT MON MAR 12 2012
...UPDATED FOR AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM CDT MON MAR 12 2012
UPPER-LEVEL TROUGHING WILL PERSIST THROUGH MARCH 18TH ACROSS THE FAR
WESTERN UNITED STATES, THEN SLOWLY PROGRESS EASTWARD AND AMPLIFY
JUST TO OUR WEST BY MARCH 19-20TH. GIVEN THE EXPECTED POSITIONING OF
THIS TROUGH OVER THE FAR WESTERN UNITED STATES BY MID-WEEK,
SOUTHWESTERLY MID-LEVEL FLOW WILL BE PRESENT ACROSS THE ROCKIES AND
OVER THE PLAINS. LEE TROUGHING WILL DEVELOP IN RESPONSE TO THE FLOW
ACROSS THE ROCKIES, AND THIS WILL SERVE TO DRAW RICH LOW-LEVEL
MOISTURE NORTHWARD INTO THE SOUTHERN PLAINS. THE SURFACE DRYLINE
WILL MARK THE INTERFACE BETWEEN THE MOIST AIRMASS OVER THE PLAINS
AND THE DRY AIRMASS OVER THE WESTERN HIGH PLAINS AND ROCKIES. IT
WILL BE WARM EVERY DAY THROUGH THE WEEKEND WITH HIGHS IN THE 70S AND
80S AND LOWS FROM THE UPPER 40S WEST TO 55 TO 62 IN SOUTH CENTRAL
KANSAS. OFTENTIMES IN RETURN FLOW SITUATIONS IN MARCH, PREVIOUS COLD
FRONTAL PASSAGES THROUGH THE GULF AND EVEN INTO THE CARIBBEAN RESULT
IN ONLY MODEST MOISTURE RETURNS INTO THE PLAINS. THIS WILL NOT BE
THE CASE THIS WEEK SINCE THE GULF SEA SURFACE IS NEARLY AT
EQUILIBRIUM WITH THE AIR IMMEDIATELY ABOVE. GULF BUOY DATA INDICATE
DEWPOINTS AROUND 70F IN THE CENTRAL GULF CURRENTLY, WHICH IS VERY
IMPRESSIVE FOR THIS TIME OF YEAR. KEEP IN MIND THAT JUST BECAUSE 70F
DEWPOINTS ARE PRESENT IN THE CENTRAL GULF DOESN`T MEAN THAT WE CAN
EXPECT DEWPOINTS THAT HIGH IN SOUTHWEST KANSAS LATER THIS WEEK.
WHEN MOIST, MARINE AIR MOVES NORTHWARD INTO THE PLAINS, DEEP
VERTICAL MIXING OCCURS, WHICH CAUSES THE MOIST LAYER TO BE DEEPER,
BUT NOT QUITE AS RICH. ALSO, DODGE CITY IS 2600FT ABOVE SEA LEVEL
AND THIS INCREASED ELEVATION WILL RESULT IN SOME REDUCTION IN
DEWPOINT AS WELL AS THE MOISTURE MOVES ONTO THE HIGHER TERRAIN. SO
IT IS MORE REASONABLE TO EXPECT DEWPOINT TEMPERATURES FROM THE MID
50S TO THE MID 60S (13-18C) AHEAD OF THE DRYLINE.
BY WEDNESDAY AFTERNOON, THE SURFACE DRYLINE WILL STRETCH FROM A
WEAK SURFACE LOW AND FRONT OVER SOUTHWEST KANSAS SOUTH-SOUTHWESTWARD
INTO THE TEXAS PANHANDLE. A SUBTROPICAL JET STREAK WILL BE SITUATED
ACROSS THE TEXAS PANHANDLE. SURFACE BASED CAPE VALUES WILL APPROACH
2000 J/KG BY LATE AFTERNOON FROM DODGE CITY SOUTH AND EAST. THERE
MAY BE ENOUGH CONVERGENCE ALONG THE DRYLINE AND NEAR THE FRONT-
DRYLINE INTERSECTION, ALONG WITH STRONG ELEVATED HEATING, TO YIELD
ISOLATED THUNDERSTORMS. ANY STORMS THAT DEVELOP COULD BE SEVERE WITH
LARGE HAIL.
ISOLATED THUNDERSTORMS CANNOT BE RULED ANY DAY THROUGH MARCH 20TH AS THE
SURFACE DRYLINE REMAINS OVER WESTERN KANSAS. THE ECMWF INDICATES
THAT THE BEST CHANCES MAY BE SATURDAY FROM DODGE CITY SOUTHEASTWARD,
AND THEN AGAIN BY MONDAY AND TUESDAY AS THE UPPER-LEVEL TROUGH AND
ASSOCIATED MID-LEVEL COOLING APPROACH WESTERN KANSAS. ANY STORMS
THAT DEVELOP IN THESE PERIODS COULD BE SEVERE, ALTHOUGH THE BEST
CHANCE OF HIGH-END SEVERE STORMS WITH TORNADOES SHOULD BE LATER
MONDAY OR TUESDAY AS THE MID TO HIGH-LEVEL WINDS BECOME MUCH
STRONGER IN ADVANCE OF THE UPPER-LEVEL TROUGH. OF COURSE, A LOT
COULD CHANGE BETWEEN NOW AND MARCH 19TH-20TH; AND IT IS IMPOSSIBLE
TO SAY AT THIS POINT EXACTLY WHERE IN THE PLAINS THE BEST CHANCE
OF THUNDERSTORMS WILL BE.
KEEP IN MIND THAT DUE TO THE VERY WARM EXPECTED TEMPERATURES, RECORD
HIGH NIGHTTIME AND DAYTIME TEMPERATURES ARE POSSIBLE ACROSS WESTERN
KANSAS LATER THIS WEEK AND THIS WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 600 AM CDT MON MAR 12 2012
VFR CONDITIONS WILL PREVAIL. A WEAK TROUGH OF LOW PRESSURE WILL BE SITUATED
THROUGH THE CENTRAL PLAINS TODAY. WINDS WILL SHIFT TO THE NORTHWEST
BEHIND THIS TROUGH BY MIDDAY. THE PRESSURE GRADIENT WILL WEAKEN BY
LATE AFTERNOON RESULTING IN LIGHT WINDS BY THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 402 AM CDT MON MAR 12 2012
FIRE WEATHER WILL BE A CONCERN ON TUESDAY. AFTERNOON VERTICAL
MIXING WILL RESULT IN RELATIVE HUMIDITIES FROM 10 TO 15 PERCENT
ALONG WITH FREQUENT WIND GUSTS NEAR OR JUST IN EXCESS OF 25 MPH.
A FIRE WEATHER WATCH IS IN EFFECT ALONG AND WEST OF A LINE FROM
MEADE TO DIGHTON. THIS WAS NOT UPGRADED SINCE THERE IS SOME
QUESTION AS TO WHETHER SURFACE WINDS WILL BE STRONG ENOUGH. ALSO
ELLIS AND TREGO COUNTIES MAY NEED TO BE ADDED.
AFTER A LESSENING OF THE PRESSURE GRADIENT WEDNESDAY AND THURSDAY,
FIRE WEATHER WILL BE A CONCERN EVERY DAY FROM FRIDAY THROUGH SUNDAY,
ESPECIALLY IN FAR WESTERN KANSAS BEHIND THE SURFACE DRYLINE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 77 41 83 46 / 0 0 0 0
GCK 76 39 82 42 / 0 0 0 0
EHA 75 38 82 41 / 0 0 0 0
LBL 76 39 81 42 / 0 0 0 0
HYS 78 42 82 46 / 0 0 0 0
P28 78 44 81 53 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ065-066-
079>081-089-090.
&&
$$
UPDATE...BURKE
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
821 AM EDT MON MAR 12 2012
.SYNOPSIS...
LOW PRESSURE, MOVING NORTHEASTWARD TO WISCONSIN, WILL PUSH A WARM
FRONTAL BAND OF SHOWERS EASTWARD THROUGH THE UPPER OHIO VALLEY
THIS AFTERNOON AND EVENING, FOLLOWED BY A SECOND BAND OF SCATTERED
SHOWERS TUESDAY. HIGH PRESSURE WILL FOLLOW WITH DRY CONDITIONS
INTO THURSDAY AND SPRINGLIKE CONDITIONS INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS UPDATE CONSISTED MAINLY OF TWEAKS BASED ON BLEND OF RECENT
SURFACE AND RADAR DATA AND HRRR AND NAM MODEL OUTPUT.
THINKING REMAINS THAT A LOW PRESSURE CENTER, MOVING NORTHEASTWARD
TOWARD WISCONSIN, WILL PUSH A WARM FRONTAL BAND OF NUMEROUS
SHOWERS EASTWARD THROUGH THE UPPER OHIO VALLEY THIS AFTERNOON AND
EVENING. MAINTAINED A SLIGHT CHANCE OF THUNDER, AS SURFACE
TEMPERATURES AND INSTABILITY CAN BE STUNTED BY PRECEDING CLOUD
COVER. FOR EXAMPLE, HIGHS IN EAST CENTRAL OHIO MAY OCCUR MIDDAY.
LOWS TONIGHT CAN BE 15 TO 20 DEGREES WARMER THAN NORMAL PER RECENT
GFS AND NAM MOS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
UPPER LEVEL TROUGH AXIS WILL CROSS THE GREAT LAKES TUESDAY AND
WITH MOIST LOW LEVELS SHOULD BE ABLE TO PRODUCE SCATTERED SHOWERS.
BEHIND THIS DRY CONDITIONS AND WELL ABOVE NORMAL TEMPERATURES
THROUGH WEDNESDAY UNDER SURFACE RIDGE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THE EXTENDED FORECAST WILL RESEMBLE MORE OF A SPRINGTIME PATTERN
THAN A LATE WINTER PATTERN.
AN UPPER LEVEL RIDGE WILL REMAIN FIXED ALONG THE EAST COAST
THROUGHOUT THE PERIOD. SOUTHERLY WINDS, AHEAD OF GREAT PLAINS LOW
PRESSURE, WILL ADD GULF MOISTURE TO THE SPRINGLIKE WARMTH. HENCE,
DAYTIME SHOWERS AND LATE DAY THUNDERSTORMS MAY BE POSSIBLE BY
LATER THURSDAY. TEMPERATURES WILL REMAIN MORE THAN 15 DEGREES
ABOVE NORMAL ON AVERAGE.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
VFR ALTOCUMULUS CEILINGS WILL LOWER TO STRATOCUMULUS LEVELS LATE
MORNING WITH ONSET OF WARM FRONTAL BAND OF NUMEROUS RAIN SHOWERS
AND ISOLATED THUNDERSTORMS.
LATER THIS AFTERNOON, AS THE RAIN SHOWERS MOISTEN THE SURFACE
LAYER, VISIBILITIES AND CEILINGS CAN LOWER TO MVFR. NOCTURNAL
COOLING CAN HELP MAINTAIN MVFR CONDITIONS TONIGHT.
WINDS WILL GENERALLY REMAIN SOUTHERLY AT 10KTS WITH GUSTS TO 20
KTS THIS AFTERNOON AND EARLY EVENING.
OUTLOOK...TUESDAY THROUGH FRIDAY...
RESTRICTIONS MAY STILL BE POSSIBLE WITH A SECOND FRONTAL BAND OF
SHOWERS TUESDAY MORNING. HIGH PRESSURE WILL PROMOTE VFR LATER TUESDAY
INTO THURSDAY. RESTRICTIONS WITH SHOWERS WILL BE POSSIBLE THURSDAY
NIGHT AND FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
717 AM EDT MON MAR 12 2012
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 411 AM EDT MON MAR 12 2012
WV IMAGERY AND RUC ANALYSIS SHOWING UPPER LOW SPINNING OVER ERN
NEB. BROAD AREA OF LIGHT/MOD RAIN ON RADAR/OBS COVERING MUCH OF WI
AT THIS TIME AND PUSHING N. THIS WILL BE THE INITIAL FEATURE OF
CONCERN FOR THE FIRST PART OF THE MORNING.
THIS PCPN IS LOCATED ALONG AN AREA OF H925-700 WAA/FGEN...ALONG WITH
290-300K ISENTROPIC ASCENT. IN ADDITION...NOSE OF UPPER JET ROTATING
AROUND THE BASE OF THE UPPER LOW IS FOCUSED OVER WI AND WITH THE
AREA OF PCPN. HAVE DEFINITE POPS PUSHING N ACROSS THE CWA AS THIS
AREA OF RAIN PUSHES N...BUT THERE IS CONCERN ON WHETHER THIS WILL
HOLD TOGETHER. MODELS CONSISTENT ON THIS AREA OF FORCING DIMINISHING
AND SHEARING OUT AS IT PUSHES N INTO THE CWA EARLY THIS MORNING AND
ENCOUNTERS EXISTING DRY AIR. HIRES MODELS...INCLUDING
RUC/HRRR...HAVE BEEN HANDLING THE COVERAGE OF THE RAIN WELL THIS
MORNING AND ALSO SHOW THE PCPN DIMINISHING AS IT MOVES OVER THE NRN
HALF OF THE CWA. PCPN MAY ACTUALLY END FOR A PERIOD OF TIME OVER
PORTIONS OF THE SW CWA SHORTLY AFTER MORNING DRIVE TIME. EXPECT LOW
CLOUDS TO REMAIN IN PLACE BEHIND THIS INITIAL SURGE OF RAIN...AS DRY
AIR ABOVE H850 ROTATES THROUGH. SHOULD ALSO SEE SOME FOG DEVELOP
THROUGH THE MORNING...ESPECIALLY FOR AREAS FAVORED BY UPSLOPE SE
FLOW...INCLUDING NCNTRL UPPER MI AND THE KEWEENAW.
AFTER A BRIEF REPRIEVE BEHIND THIS INITIAL BAND OF RAIN...SECONDARY
SURGE LOOKS TO ARRIVE TOWARDS MID DAY AND CONTINUE INTO THE AFTN.
THIS IS ASSOCIATED WITH THE UPPER LOW AND SFC TROUGH PUSHING NE
INTO THE CWA. NOSE OF THE UPPER JET WILL BE FOCUSED OVER LOWER MI
AT THIS TIME...BUT FORCING FROM THE UPPER LOW AND ASSOCIATED HEIGHT
FALLS SHOULD BE SUFFICIENT TO REDEVELOP SCT/NUMEROUS SHOWERS THAT
MOVE FROM SW TO NE ACROSS THE CWA. COULD EVEN HAVE A FEW RUMBLES OF
THUNDER OVER PORTIONS OF THE SRN HALF OF THE CWA THIS AFTN WITH ANY
OF THE STRONGER SHOWERS. WITH THE UPPER LOW AND STRONG HEIGHT FALLS
MOVING THROUGH THIS AFTN...MID LVL LAPSE RATES INCREASE AND CREATES
POCKETS OF WEAK INSTABILITY. HAVE EXPANDED THE PREVIOUS ISOLATED
THUNDER MENTION SLIGHTLY BASED OFF LATEST TRENDS. AS WINDS TURN TO
THE SW IN THE AFTN...EXPECT FOG TO BECOME MORE PATCHY...AS MODELS
INDICATE A LITTLE DEEPER MIXING. DELAYED THE DIMINISHING FOG A
LITTLE FARTHER INTO THE AFTN. CONTINUED TO LINGER THE FOG INTO THE
EVENING OVER THE E WHERE THE RELATIVELY WARM/MOIST AIR WILL BE
FLOWING OFF LK MI.
AS THE UPPER LOW MOVES OVER LK SUPERIOR LATE THIS AFTN AND
EVENING...THIRD WAVE OF RAIN WILL AFFECT MAINLY THE WRN HALF OF THE
CWA. THIS IS ASSOCIATED WITH THE WRAP AROUND MOISTURE AND WEAK
290-305K ISENTROPIC ASCENT. THIS SHOULD CONTINUE THROUGH MUCH OF THE
EVENING HOURS OVER THE W HALF...AS THE BACK EDGE OF THE PCPN SLIDES
FROM MN AND THROUGH THE AREA. WITH THE MOISTURE AND PCPN CLOSELY
TIED WITH THE UPPER LOW...EXPECT A QUICK DIMINISHING TREND TO
POPS/SKY AFTER MIDNIGHT TONIGHT AS THE LOW MOVES INTO ONTARIO.
OVERALL...TRYING TO TIME THESE FEATURES IS EXTREMELY
DIFFICULT...ESPECIALLY WITH THE SEVERAL PERIODS OF RAIN. HAVE OPTED
TO GO WITH A SHOWERY WORDING INSTEAD OF STRATIFORM DUE TO THESE
PERIODS.
TUES...UPPER LOW THAT PASSED THROUGH THE AREA TODAY AND THIS EVENING
WILL PHASE WITH NRN STREAM TROUGH JUST TO THE N OF LK SUPERIOR ON
TUES. THIS WILL LEAD TO NW FLOW ALOFT ON TUES...BUT TROUGH IS
QUICKLY SHIFTING EAST. SOME DIFFERENCES IN HOW FAR S THE PHASING
OCCURS...WHICH COULD LEAD TO SOME LINGERING CLOUDS OVER THE KEWEENAW
AND FAR ERN UPPER MI. 18Z/00Z GFS WAS MUCH FARTHER S THAN OTHER
MODELS...WHICH ACTUALLY HOLDS PCPN INTO THE MORNING HOURS OVER FAR
ERN UPPER MI DUE TO THE DEEPER PHASING. WILL KEEP THE CLOUDS MAINLY
OVER NE LAKE SUPERIOR TO ACCOUNT FOR THIS UNCERTAINTY.
DECENT SPREAD IN GUIDANCE FOR HIGHS DUE TO THE DIFFERENCES IN
HANDLING THE PHASING OF THE UPPER THROUGH. MIXING TO H875-850
/AROUND 2C/ YIELDS HIGHS IN THE MID 50S...SO HAVE ADJUSTED EXISTING
HIGHS DOWN A TOUCH. WITH MAINLY NW FLOW...HAVE KEPT TEMPS NEAR LK
SUPERIOR A LITTLE COOLER. DEWPOINT VALUES WILL BE THE MAIN CONCERN
FOR TUES AFTN. DROPPED VALUES A GOOD 7-10 DEGREES OVER THE WRN
HALF OF THE CWA...WITH MODELS CONSISTENTLY SHOWING DECENT MIXING
INTO DRY AIR ALOFT. SOME OF OUR LOCAL MIXED TD TOOLS ACTUALLY GIVE
VALUES IN THE SINGLE DIGITS ABOVE ZERO...WHICH DOESN/T SEEM TOO
UNREASONABLE. STRAIGHT MODEL MIXED TD VALUES ARE IN THE LOWER
TEENS...SO HAVE TRENDED TOWARDS THAT WITH VALUES IN THE UPPER
TEENS. FORTUNATELY...THERE IS STILL A DECENT SNOW PACK...OTHERWISE
THERE COULD BE FIRE WX CONCERNS WITH GUSTY NW WINDS AND RH VALUES
FALLING INTO THE LOW 20S.
TUES NIGHT...WITH UPPER TROUGH CONTINUING E AND UPPER RIDGE
REBUILDING OVER THE NRN PLAINS...EXPECT DRY WX AND MOSTLY CLEAR
SKIES. SFC RIDGE MOVING ACROSS THE AREA WILL LEAD TO LIGHT WINDS
AND HAVE DROPPED TEMPS A FEW DEGREES. COULD SEE TEMPS FALL A LITTLE
MORE THAN EXPECTED OVER THE ERN CWA...DUE TO LIGHTER WINDS AND DRY
AIR ALOFT PRODUCING PWATS AROUND 70 PERCENT OF NORMAL. HAVE COOLED
THE TRADITIONAL COLD SPOTS SOME OVER THE ERN CWA TO BELOW FREEZING
VALUES. FINALLY...H850 WAA COULD LEAD TO A FEW CLOUDS DEVELOPING
OVER THE WRN LK AND WRN UPPER MI AFTER MIDNIGHT...BUT LIMITED
MOISTURE HAS CONFIDENCE LOW.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 411 AM EDT MON MAR 12 2012
WED...THE UPR RDG OVER THE GRT LKS WL MOVE SLOWLY TO THE E...BUT ITS
EWD PROGRESS WL BE SLOWED BY CUTOFF LO OVER NEW ENGLAND. AS A FAIRLY
STRONG DISTURBANCE MOVES INTO CNTRL CAN...ITS ATTENDANT TROF WL
APRCH THE UPR LKS BY LATE IN THE DAY. THE NAM IS THE FASTEST MOVING
THIS TROF ACRS THE CWA ON WED...BUT PREFER THE CONSENSUS OF THE
SLOWER MODELS GIVEN THE BLOCKING CUTOFF IN NEW ENGLAND. THESE MODELS
HINT THE TROF WL REACH THE W ONLY LATE IN THE DAY. WITH THE DRYNESS
OF THE ANTECEDENT AIRMASS AND A LACK OF ANY SGNFT UPR FORCING SO FAR
S OF THE DISTURBANCE MOVING THRU CNTRL CAN...OPTED TO RETAIN GOING
DRY FCST. WITH H85 TEMPS PEAKING ARND 10C...EXPECT ANOTHER DAY OF
WELL ABV NORMAL TEMPS...EVEN IF THE MORE PESSIMISTIC GFS IS CORRECT
ON SHOWING ENUF LLVL MSTR ARRIVING TO SUPPORT SC DEVELOPMENT IN THE
SW FLOW AHEAD OF THE INCOMING TROF. MIXING TO JUST H875 ON GFS FCST
SDNGS WOULD YIELD HI TEMPS APRCHG 70 AWAY FM THE MODIFIYING
INFLUENCE OF LK MI WITH LLVL SLY FLOW...ESPECIALLY IN THE DOWNSLOPE
AREAS W OF MQT. SUSPECT AT LEAST SOME PLACES OVER THE W HALF MAY SEE
DAILY RECORD HI TEMPS.
WED NGT...AS THE SFC TROF/PACIFIC TYPE COLD FNT MOVES E ACRS THE
CWA...THE 00Z GFS AND ESPECIALLY THE CNDN MODELS ARE MOST AGGRESSIVE
AT GENERATING SOME PCPN OVER MAINLY THE SE ZNS UNDER AREA OF STEEPER
H7-5 LAPSE RATES UP TO 7.5-8.0C/KM AND SHOWALTER INDEX AS LO AS -2
TO -4C. THE CNDN INSTABILITY IS GREATER AS THIS MODEL SHOWS A
STRONGER SHRTWV MOVING ENEWD IN THE WSW FLOW ALF. ALTHOUGH THE TIME
OF DAY WOULD NOT BE CONDUCIVE TO TS...OPTED TO INCLUDE SCHC TS OVER
THE SE ZNS CONSIDERING THE ANOMALOUS LLVL WARMTH OF THE ANTECEDENT
AIRMASS/FCST STABILITY INDICES. DRIER AND SOMEWHAT COOLER AIR WL
ARRIVE OVER ESPECIALLY THE W IN THE WAKE OF THE COLD FROPA AS WEAK
HI PRES MOVES TO THE MN ARROWHEAD BY 12Z THU.
EXTENDED...THE STEADY SLY FLOW BTWN WRN TROF/ERN RDG WL PERSIST THRU
THE WEEKEND WITH NEAR UNPRECEDENTED WARMTH POSSIBLE FRI THRU SUN IN
THE PRESENCE OF H85 TEMPS NOT FAR FM 10-12C. THE THU-FRI PERIOD
SHOULD BE DRY WITH HI PRES RDG OVER THE AREA...BUT THERE WL BE A CHC
OF SHRA OVER THE WEEKEND AS HI PRES SHIFTS TO THE E. LACK OF
CONSISTENCY ON SHRTWV PRESENCE/TIMING SUGS NO MORE THAN CHC POPS ARE
WARRANTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 716 AM EDT MON MAR 12 2012
COMPLEX AVIATION FORECAST TODAY...AS AN UPPER LEVEL DISTURBANCE
LOCATED OVER NW IOWA AND SOUTHERN MN MOVES NORTHEAST ACROSS UPPER
MICHIGAN. THE FIRST WAVE OF -RA HAS QUICKLY MOVED IN THIS MORNING.
EXPECT THIS STEADIER RAIN TO END FROM S TO N OVER THE NEXT COUPLE
OF HOURS. THIS WILL LEAD TO MORE OFF/ON SHOWERS AT THE TAF
SITES...WITH CONCERNS FOR UPSLOPE FOG AT BOTH KCMX/KSAW. WITH THE
FAVORABLE SE WINDS AND INCREASING MOISTURE...EXPECT AIRFIELD LANDING
MINS TO BE REACHED FROM MID MORNING INTO MID AFTN. HAVE KEPT KIWD A
LITTLE HIGHER DUE TO UNFAVORABLE SE FLOW. EXPECT THE FOG TO DIMINISH
AS WINDS TURN SW THIS AFTN...BUT THIS WILL BRING THE SECOND PERIOD
OF SHOWERS. UPSTREAM OBS REINFORCE THE POTENTIAL FOR LOW MVFR AND
IFR CIGS TO REMAIN THROUGH THE EVENING WITH THESE SHOWERS. AS THE
LOW MOVES NE OVERNIGHT...EXPECT A QUICK TRANSITION TO CLEAR SKIES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 AM EDT MON MAR 12 2012
UPPER LEVEL DISTURBANCE AND SURFACE TROUGH WILL SLIDE NE ACROSS
LAKE SUPERIOR THIS AFTERNOON AND TONIGHT. EXPECT SSE WINDS TO
MAINLY STAY BELOW 20KTS...BUT THERE COULD BE A FEW GUSTS TO 25KTS
OVER THE NRN LK. AS WARM/MOIST AIR MOVES OVER LAKE SUPERIOR
TODAY...SHOULD SEE AREAS OF FOG DEVELOP LATE THIS MORNING AND
CONTINUE INTO THIS EVENING. BEHIND THE SURFACE TROUGH...EXPECT
WINDS TO INCREASE OUT OF THE WEST AFTER MIDNIGHT AND CONTINUE INTO
TUESDAY. WARM AIR ABOVE THE SURFACE WILL LIKELY KEEP THE MARINE
LAYER IN PLACE AND LIMIT THE VERY STRONG WINDS ALOFT FROM
REACHING THE SURFACE. AT THIS TIME...ONLY HAVE GUSTS REACHING
30KTS. AFTER TUESDAY...WINDS WILL REMAIN UNDER 25KTS WITH A
RELATIVELY WEAK PRESSURE GRADIENT IN PLACE.
&&
.HYDROLOGY...
ISSUED AT 411 AM EDT MON MAR 12 2012
NEAR RECORD TO RECORD SETTING TEMPS YESTERDAY HAS HELPED RIPEN THE
SNOW PACK. RAIN TODAY AND FOR PARTS OF TONIGHT WILL PROVIDE
ADDITIONAL MOISTURE TO THE AREA. EXPECT THE BULK OF THE
RAIN TO FALL DURING THE MORNING TO EARLY AFTERNOON HOURS...WITH
ACCUMULATIONS OF AROUND 0.25 TO 0.40IN. THE RAIN...COMBINED
WITH DEWPOINTS RISING INTO THE 40S...WILL HELP TO QUICKEN
SNOWMELT. AS OF THIS MORNING...THERE HAS BEEN ONLY LIMITED
RESPONSES ON THE LARGER RIVERS.
THE RAIN AND SNOW MELT TODAY...COMBINED WITH ABOVE NORMAL
TEMPERATURES THROUGH NEXT WEEKEND WILL LEAD TO A INCREASE IN
RIVER AND STREAM LEVELS OVER THE NEXT SEVERAL DAYS. EXPECT SOME OF
THE RIVERS ACROSS THE AREA TO EXCEED THEIR BANKS BY THE END OF THIS
WEEK. PERSONS LIVING NEAR RIVERS AND STREAMS SHOULD
MONITOR THE LATEST RIVER CONDITIONS AND USE CAUTION IF WALKING
ALONG RIVER BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
ICE JAM WISE...NOT MUCH ICE HAS BEEN NOTED BY OBSERVERS ON THE
FASTER FLOWING RIVERS OVER NRN UPPER MI. BUT THE FORD RIVER...BOTH
AT HYDE AND THE MOUTH AT LK MI...STILL HAS GOOD ICE COVER THAT
LEADS TO SOME CONCERN FOR ICE JAM POTENTIAL WITH THE FASTER RUNOFF.
ALTHOUGH LIMITED SNOW WAS NOTED NEAR LK MI...THERE IS STILL 4-9IN
OF SNOW ...AND NOHRSC ESTIMATED AROUND 1.25IN OF LIQUID...TOWARDS
THE HEADWATERS THAT WILL BE MELTED OVER THE COMING DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
951 AM CDT MON MAR 12 2012
.DISCUSSION...
RAIN CONTINUES TO BE CONCENTRATED ALONG THE MID LEVEL
FRONTOGENESIS BAND...CURRENTLY STRETCHING FROM THE SOUTHERN RED
RIVER VALLEY UP TOWARDS ROSEAU...BUT THE BAND SHOULD CONTINUE TO
PUSH SLOWLY EAST THROUGHOUT THE DAY. MADE ONLY A FEW MINOR TWEAKS
TO GOING POPS AS WHAT WE HAD CURRENTLY SEEMED TO CAPTURE THE BAND
WELL. MAIN CHANGE FOR THE MORNING UPDATE WAS TO ADD FOG TO THE
GRIDS FOR MUCH OF THE MORNING. INCLUDED A PATCHY MENTION ALONG THE
RAIN BAND BUT AREAS OF FOG JUST TO THE EAST AND WEST OF THE RAIN.
SOME AWOS SITES IN THE NORTHWEST AND SOUTHEASTERN COUNTIES ARE DOWN
TO A QUARTER OF A MILE...BUT WEBCAMS SHOW THAT COVERAGE IS NOT
WIDESPREAD. FOG SHOULD DECREASE THIS AFTERNOON AS WINDS PICK UP IN
THE WESTERN COUNTIES AND THE RAIN BAND MOVES INTO THE EAST. WILL
HOLD OFF ON ANY FOG HEADLINES AND JUST COVER WITH NOWCASTS FOR THE
TIME BEING.
&&
.AVIATION...
A BAND OF LIGHT TO MODERATE RAIN SHOWERS FROM LISBON TO GRAND FORKS
TO ROSEAU WILL CONTINUE TO MOVE NORTH AND EAST LATE THIS MORNING AND
AFTERNOON. IFR/LIFR CEILINGS WILL GRADUALLY IMPROVE FROM WEST TO
EAST THIS AFTERNOON AND EVENING. VISIBILITY WILL BE REDUCED TO 1 SM
AT TIMES IN RAIN ALONG AND EAST OF THE VALLEY...AND DOWN TO 1/4 SM IN
FOG AT KTVF AND KBJI. SOME FOG/MIST IS ALSO POSSIBLE AT OTHER TAF
SITES. AS CEILINGS IMPROVE...SOUTHERLY WINDS WILL SHIFT TO THE
NORTHWEST AND BECOME BREEZY THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT MON MAR 12 2012/
SHORT TERM...MAIN CONCERNS WILL BE RAIN AND QPF ALONG WITH WIND
SPEEDS TODAY. 00Z MODELS IN DECENT AGREEMENT WITH SYNOPTIC
FEATURES AND WILL USE A BLEND.
UPPER LOW WILL PROPAGATE THROUGH IOWA AND INTO THE GREAT LAKES
REGION BY THIS EVENING...WHILE ANOTHER SHORTWAVE ACROSS THE NW
CONUS WILL PROPAGATE INTO THE NORTHERN FA. THESE TWO WAVE WILL
MAKE FOR A COMPLICATED FORECAST SCENARIO. MODELS APPEAR TO BE
HINTING THAT A BAND OF MODERATE RAIN WILL SET UP SOMEWHERE ACROSS
THE FA AND SLOWLY MOVE EAST. THIS BAND WILL BE ASSOCIATED WITH
STRONG 850-700MB FRONTOGENESIS...SYMMETRIC INSTABILITY...AND PWATS
UP TOWARD 0.9 INCHES. GIVEN THE BANDING POTENTIAL...THINK THAT
LOWER RESOLUTION MODELS ARE UNDERESTIMATING QPF POTENTIAL (SHOWING
UP TO 0.25 INCHES). HIGHER RESOLUTION MODELS ARE INDICATING 0.50
TO 1.00 INCH...WHICH APPEARS POSSIBLE GIVEN THE FORCING
MECHANISMS AND AVAILABLE MOISTURE. THE MAIN QUESTION IS WHERE WILL
THE BAND SET UP...AND HOW FAR NORTH WOULD THE HIGHER RAIN TOTALS
BE. MUCH DEPENDS ON THE EXACT SPEED OF THE EACH WAVE. WILL FOLLOW
THE HRRR AND RUC WHICH APPEAR TO HAVE A HANDLE ON THE CURRENT
RADAR TRENDS. GIVEN THESE MODELS...AND CURRENT RADAR...IT APPEARS
THIS BAND OF RAIN WILL BE LOCATED FROM THE SOUTHWEST FA INTO THE
NE FA THIS MORNING. HRRR AND RUC INDICATING STRONGER FORCING
ACROSS THE SOUTHERN FA...WITH THE HIGHER QPF TOTALS ACROSS THE
SOUTHERN VALLEY. GIVEN UNCERTAINTY...WILL GO WITH AREAL AVERAGE
QPF 0.30-0.50 INCHES WITHIN THIS EXPECTED RAIN BAND (PLUS 1.0 INCH
RAINFALL WOULD LIKELY BE ISOLATED). WILL TRY TO REFINE THIS ONCE
MORE CONFIDENCE IS OBTAINED. AS THE SECOND KICKER WAVE
APPROACHES...CLEARING SHOULD MOVE THROUGH FROM WEST TO EAST BY
THIS EVENING.
MODELS INDICATE STRONG 850MB COLD AIR ADVECTION WITH WINDS 40-43
KNOTS AT THIS LEVEL ACROSS THE DEVILS LAKE BASIN BY THIS
AFTERNOON. WILL ISSUE A WIND ADVISORY FOR THIS AREA. THE COLD AIR
ADVECTION WEAKENS AS IT MOVES EAST...WHICH SHOULD KEEP ADVISORY
CONDITIONS CONFINED TO THE DEVILS LAKE BASIN. TEMPERATURE TRICKY
TODAY...BUT THINK SOME SOLAR WILL GET TEMPS INTO THE 50S VALLEY
AND WEST (40S WHERE CLOUD COVER EXPECTED MUCH OF THE DAY).
PROGRESSIVE PATTERN REMAINDER OF THE PERIOD AND TIMING WILL HAVE
AFFECT ON TEMPERATURES. APPLIED A MODEL BIAS FROM THE PAST COUPLE
DAYS FOR GUIDANCE. NO MEASURABLE PRECIP EXPECTED.
LONG TERM (THUR-SUN)...EARLY IN THE EXTENDED PERIOD MODELS IN
GOOD AGREEMENT THAT AN UPPER LOW WILL BE PASSING WELL NORTH OF THE
REGION. RESULTANT WESTERLY SURFACE FLOW WILL CONTINUE THE DRY AND
WARM WEATHER. FLAT WESTERLY FLOW GRADUALLY TRANSITIONS TO MORE
SOUTHWEST FLOW BY LATER ON FRIDAY. ECMWF SLOWER THAN THE
GFS/DGEX/GEM AND BASED ON OVERALL HEMISPHERIC PATTERN PROBABLY
BETTER.
VARIOUS ENSEMBLES IN AGREEMENT THAT BLOCKING OVER THE NORTHEAST U.S.
IN THE FORM OF VERY STRONG RIDGE WILL FAVOR DEEP TROUGH OVER EASTERN
PACIFIC/WESTERN U.S. BY SATURDAY DGEX/GFS BOTH BRING A SURGE OF
MODERATELY UNSTABLE AIR...FOR MARCH...INTO THE NORTHERN PLAINS. 45
KT 850 JET AND LI IN THE -2C TO -4C RANGE SET UP JUST AHEAD OF COLD
FRONT FORECAST TO MOVE THROUGH LATE IN THE DAY. SURFACE TD REACH THE
MID 50S WITH OPEN GULF OF MEXICO FLOW FORECAST FOR SEVERAL DAYS
AHEAD OF DEEPENING SURFACE LOW.
WHILE CLIMATOLOGICALLY NOT THE BEST TIME OF YEAR TSRA NOT UNHEARD OF
IN MID MARCH SO PUT TSRA VALLEY EAST SATURDAY AND EAST OF VALLEY
SATURDAY NIGHT. IF SLOWER ECMWF VERIFIES COULD EASILY SEE MORE
THUNDER AT END OF PERIOD.
MAX TEMPERATURES PEAK INTO THE 60S FRIDAY AND SATURDAY AHEAD OF
STRONG UPPER WAVE AND SURFACE FRONT. ATTM FORECAST TEMPERATURES TO
COOL BACK INTO THE 50S BEHIND EXPECTED FRONT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR NDZ006-007-014-015-
024.
MN...NONE.
&&
$$
JR/ROGERS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
525 AM PDT SUN MAR 12 2012
.SYNOPSIS...A STRONG PACIFIC FRONT WILL BRING STRONG WINDS...HEAVY
RAIN AND MOUNTAIN SNOW TODAY. A SERIES OF SYSTEMS WILL MAINTAIN
DAMP AND COOL WEATHER THROUGH NEXT WEEK.
&&
.UPDATE...WE ARE ISSUING A WIND ADVISORY FOR THE VALLEY...GUSTS TO
50 MPH POSSIBLE IN THE SOUTH AND CENTRAL VALLEY...GENERALLY 45 MPH
IN THE NORTH. SEE THE LATEST NPWPQR FOR MORE DETAILS. REASONING IS
THAT THE WARM SECTOR WILL GET INTO AREAS SOUTH OF MCMINNVILLE/SALEM
BRINGING THE POTENTIAL FOR SOME GOOD GUSTS...AND A LITTLE LESS
FAVORABLE ORIENTATION TO THE PRES GRADIENT FARTHER NORTH.
MCMINNVILLE HAS A GUST TO 47 MPH...AND EUGENE AND MCMINNVILLE HAVE
SUSTAINED WINDS OF 30 MPH. PEAK WINDS WILL BE THIS
MORNING...LINGERING SOUTH IN THE AFTERNOON. HEADLINES ARE UPDATED
BELOW.
ON THE MARINE FRONT...BUOY 89 HAD A PEAK GUST TO 58 KT AS OF
12Z...AND SEAS ARE ALREADY UP TO 22 TO 26 FT.
AND ON COASTAL WINDS...LINCOLN CITY HAD A GUST TO 61 MPH...AND THE
GRADIENT IS REALLY TIGHT...BUT THE WARM SECTOR IS STILL SOUTH...BUT
SHOULD BE HEADING NORTH THROUGH THE MORNING.
.SHORT TERM...POTENT STORM SYSTEM TO DEAL WITH IN THE NEXT 24 HOURS.
THE VERY STRONG SUBSIDENCE SEEN IN WATER VAPOR PICTURES NEAR 46N
130W SUPPORTS THE EXPLOSIVE CYCLOGENESIS DEPICTED IN THE MODELS
BETWEEN 06Z AND 12Z THIS MORNING. MODELS CONTINUE TO SHOW A VERY
STRONG WIND FIELD ALOFT. THE TRIPLE POINT OF THE FRONT IS DIFFICULT
TO DETERMINE DEFINITIVELY...MAKING THE FORECAST OF LAND WINDS AND
SNOW LEVELS N OF THE WARM FRONT ALL THE MORE DIFFICULT. ISENTROPIC
LIFT WITH THIS SYSTEM IS MODEST...MODELS INDICATE MOST OF THE LIFT
COMING WITH STRONG FRONTOGENESIS...WHICH MEANS THE SPREAD OF HEAVY
PRECIPITATION INLAND WILL BE RELATIVELY SLOW AND TIED TO THE SURFACE
COLD/OCCLUDED FRONT. BEST GUESS IS THAT THE TRIPLE POINT IS HEADED
INLAND ON THE NORTH OR CENTRAL OREGON COAST...AND INLAND INTO THE S
WILLAMETTE VALLEY. THIS WOULD PUT THE POTENTIAL FOR STRONGEST
SURFACE WINDS ON THE OREGON COAST...ALTHOUGH CONVECTIVE GUSTS
FURTHER N SHOULD STILL EXCEED HIGH WIND CRITERIA AS EVIDENCED BY
OBSERVED WINDS OVERNIGHT AT CLATSOP SPIT AND CAPE DISAPPOINTMENT.
GIVEN MODELS CONTINUOUSLY PUTTING PEAK GUSTS OVER THE WATER ON THE
ORDER OF 75 KT TODAY... WILL BUMP UP PEAK GUSTS SOME ESP ON THE
OREGON COAST. INLAND WINDS ALSO PROBLEMATIC AS THE UW MM5-NAM MODEL
CONTINUES TO SUGGEST WIND ADVISORY TYPE GUSTS IN THE VALLEY TODAY.
GIVEN THE LACK OF A STRONG N-S SURFACE PRES GRADIENT THOUGH...AM
RELUCTANT TO ISSUE ANY SORT OF INLAND ADVISORIES FOR WIND UNTIL WILL
SEE SOME EVIDENCE OF SUCH WINDS DEVELOPING IN SURFACE OBSERVATIONS.
AT THE END OF THE DAY...00Z TUE...WRF-GFS SUGGESTS TAIL END OF A
BENT BACK OCCLUSION BRINGING ANOTHER SHOT OF WINDS TO THE S WA AND N
OREGON COAST. AS THIS APPEARS TO BE A NEW DEVELOPMENT NOT SUPPORTED
BY OTHER MODELS...WILL NOT ACT ON THIS FEATURE BUT IT DOES BEAR
WATCHING TODAY.
SURFACE OBSERVATIONS SUGGEST SNOW LEVEL ON THE ORDER OF 1500-2000
FEET EARLY THIS MORNING. WITH LOW LEVEL OFFSHORE FLOW...SNOW LEVELS
LOOK UNLIKELY TO WARM MUCH UNTIL MAYBE THE END OF THE DAY WHEN WIND
FINALLY PICKS UP AN ONSHORE COMPONENT. WITH FAIRLY HEAVY
PRECIPITATION RATES EXPECTED WITH THE FRONT...POTENTIAL EXISTS FOR
THE N COAST RANGE AND WILLAPA HILLS TO SEE LOWERING SNOW LEVELS IN
THE HEAVY PRECIPITATION THIS AFTERNOON AND EVENING. AS SUCH...WILL
GO FOR A WINTER STORM WARNING IN THE COAST RANGE AND WILLAPA HILLS
TODAY INTO TONIGHT...MAINLY FOR AREAS ABOVE 2000 FT. THE S WA
CASCADES AND FOOTHILLS WILL BENEFIT FROM PROLONGED GOOD OROGRAPHICS
DUE TO THE STRONG SSW LOW LEVEL FLOW...SO WILL ALSO BUMP THOSE AREAS
UP TO A WINTER STORM WARNING FOR TODAY AND TONIGHT.
THE PRECIPITATION WILL TURN TO SHOWERS BEHIND THE FRONT TUE AS
COLDER AIR MOVES IN. NAM BUFR SOUNDINGS SUGGEST SNOW LEVELS BELOW
1000 FT...BUT GIVEN ONSHORE FLOW WITH 1000-500 MB THICKNESS OF 522
DM AND H8 TEMPS ON THE ORDER OF -6 C...WILL BOTTOM OUT SNOW LEVELS
AT 1000 FT IN THE SHOWERS. SHOWERS WEAKEN WITH WEAKENING ONSHORE
FLOW TUE NIGHT...THEN CHANCE FOR PRECIPITATION INCREASE AGAIN ON WED
IN THE NW PART OF THE AREA AS MOIST WARM AIR ADVECTION KICKS IN
AHEAD OF THE NEXT SYSTEM.
.LONG TERM...NO CHANGES...PREVIOUS DISCUSSION FOLLOWS.
IT CONTINUES TO LOOK LIKE COOL AND WET WEATHER WILL DOMINATE THE
EXTENDED FCST PERIOD. A STRONG UPPER LEVEL JET AND LONGWAVE
TROUGHING PATTERN WILL REMAIN OVER THE EASTERN PAC AT LEAST
THROUGH NEXT WEEKEND. MODEL AGREEMENT IS FAIRLY GOOD THAT WARM
FRONTAL RAIN ALONG WITH GUSTY COASTAL WINDS WILL SPREAD INTO THE
FCST AREA DURING THE SECOND HALF OF WED. AN APPROACHING SHORTWAVE
WILL BRING EVEN WETTER CONDITIONS ON THU. SNOW LEVELS WILL REMAIN
FAIRLY HIGH ON WED AND THU...WITH SIGNIFICANT SNOWFALL ACCUMULATIONS
CONFINED TO THE HIGHER ELEVATIONS OF THE CASCADES. HEADING INTO NEXT
WEEKEND...THE EXTENDED MODELS CONTINUE TO SUGGEST THAT THE UPPER
LEVEL TROUGHING WILL DIG FURTHER SOUTH...WITH THE BULK OF THE ENERGY
FOCUSED IN NORTHERN CALIFORNIA. THIS WOULD LEAVE US IN A SHOWERY
PATTERN WITH SNOW LEVELS DOWN INTO THE COAST RANGE AND CASCADE
FOOTHILLS. JFP
&&
.AVIATION...CIGS WILL GENERALLY BE MVFR ALONG THE COAST..THEN DROP
TO IFR THIS MORNING AT TIMES...EVEN LIFR IN HEAVY RAIN LATE THIS
MORNING THIS AFTERNOON. BIG ISSUE WILL BE THE VERY STRONG WINDS
EXPECTED IN THE MORNING ALONG THE NORTH COAST...LINGERING INTO THE
AFTERNOON SOUTH NEAR NEWPORT. SOUTH WIND GUSTS TO 50 KT AND HIGHER
ARE POSSIBLE.
INLAND WINDS WILL INCREASE AROUND 12Z ESPECIALLY ALOFT STRONG
WINDS IN THE LOWER LEVELS AFTER 12Z MON...GENERALLY BELOW 900
MB...WILL LIKELY RESULT IN LOW-LEVEL WIND SHEAR...MAINLY SPEED
SHEAR OF +/- 15 KT OR MORE..AT MOST OF THE TAF SITES...BUT THE
BEST SHOT AT THE KPDX/KTTD TAF SITES WHERE LESS MIXING MAY BE
OCCURRING. WE WILL TAKE A CLOSER LOOK AT THIS TO SEE IF IT IS
NEEDED...BUT FLIERS SHOULD AWARE THAT WHETHER THESE WINDS SURFACE
OR NOT...WINDS AT 1000-1500 FT WILL BE IN THE 40-50 KT RANGE.
EXPECT MOST OF THE INLAND PRECIP TO HOLD OFF UNTIL MID
MORNING...WITH VFR UNTIL THEN...THEN MVFR...WITH IFR IN MODERATE
TO HEAVY RAIN THIS EVENING. WE MAY SEE SOME SNOW MIXED IN DOWN TO
LOW LEVELS LATER THIS EVENING OR OVERNIGHT...BUT CONFIDENCE LOW
RIGHT NOW.
KPDX AND APPROACHES...EXPECT PRIMARILY VFR THROUGH AT LEAST 12Z
MON. LOW- LEVEL WIND INCREASES AFTER 12Z MON...FOR A THREAT OF
LOW-LEVEL WIND SHEAR (SPEED SHEAR) OF AT LEAST +/- 15 KT. EXPECT
CIGS TO REMAIN VFR UNTIL MIDDAY WHEN CIGS WILL LOWER AS THE FRONT
APPROACHES. IFR IS POSSIBLE IN MODERATE TO HEAVY RAIN THIS
EVENING. KMD
&&
.MARINE...SEAS ARE COMING UP VERY QUICKLY THIS MORNING WITH BUOY
29 NOW UP TO 22 FT...AND THE ASTORIA CANYON BUOY WHICH IS SLIGHTLY
FURTHER OFFSHORE AT 23 FT...AND OVERALL SWAN/ENP GUIDANCE IS NOT
TOO FAR OFF THE MARK. BUOY 5...ABOUT 300 NM OFFSHORE HIT ITS
LOWEST PRESSURE OF 974 MB AT 9Z...AND NOW IS ALREADY BACK UP TO
978 MB AS THE LOW HEADS NORTH INSIDE OF 130 W. WE HAVE HAD PEAK
WINDS SO FAR TO 51 KT IN THE OUTER WATERS...BUT AN IMPRESSIVE
GRADIENT IS DRAPED OVER THE WATERS WITH PRESSURES AT THE COAST
GENERALLY STILL AT 1000 MB OR HIGHER.
THE HRRR MODEL...AMONG OTHERS...ARE STILL SHOWING HURRICANE FORCE
GUSTS UP TO 75KT OVER THE COASTAL WATERS. IT IS ADVERTISING 64 KT
GUSTS AS OF NOW...AND WE HAVE HAD PEAK WINDS AT BUOY 29 (20 NM
OFFSHORE) OF 51 KT...54 KT AT BUOY 89 (70 NM OFFSHORE) SO IT MAY BE
RUNNING HIGH...POSSIBLY A TIMING ISSUE...OR THE BUOY IS STRUGGLING TO
REPORT HIGHER GUSTS. GIVEN THAT THIS CYCLOGENESIS BOMB...SEEN IN THE
BUOY 5 OBS DROPPING 25 MB IN 8 HOURS...EXPECT THAT WE WILL SEE VERY
HIGH END STORM FORCE WINDS AND SOME HURRICANE FORCE WINDS TO
MAINTAIN THE MESOSCALE MODEL ADVERTISED WIND GUSTS.
HAVE MAINTAINED THE GOING FORECAST FOR SEAS GETTING INTO THE UPPER
TO 20S TO LOW 30S AS THE SWAN ADVERTISES...AS SEAS ARE COMING UP
FAST. THE MAJORITY OF THE ENERGY WITH THESE WAVES WILL BE WITH THE
SHORTER PERIOD 12 SECOND WAVES. ALTHOUGH THE DIRECTION WILL BE
FROM THE SOUTHWEST WE ARE STILL AT THE LOW END FOR A HIGH SURF
WARNING. THE TIDAL ANOMALIES HAVE BEEN RUNNING 1 TO 2 FEET AND
EXPECT THIS TO REACH 3 FT TOMORROW MORNING. WITH THE HIGH TIDES
AROUND 10Z TO 12Z...THIS HAS PUT THE SOUTH WASHINGTON COAST INTO
COASTAL FLOOD ADVISORY CATEGORY FOR MINOR TIDAL OVERFLOW FOR A FEW
HOURS AROUND HIGH TIDE THIS MORNING...SET AROUND 430 AM AT TOKE
POINT. WIDESPREAD COASTAL FLOODING SHOULD NOT BE A CONCERN...AS THE
TIMING OF THE HIGHEST SWELL IS EXPECTED TO BE WHEN THE TIDE IS
FALLING AND DURING LOW TIDE. DURING THE SECOND HIGH TIDE SEAS SHOULD
NOT BE HIGH ENOUGH TO PRODUCE COASTAL FLOODING. SEAS WILL REMAIN
ABOVE 20 FEET THROUGH LATE MONDAY AFTERNOON...THEN FALL OFF
OVERNIGHT MONDAY.
AN DESPITE THE UW NAM ADVERTISING 50 KT WORKING ITS WAY BACK INTO
THE N OR/S WA COAST THIS AFTERNOON...IT WAS THE ONLY MODEL DOING
SO AND ONLY IN ITS CURRENT RUN. AT THIS TIME MOST MODELS KEEP THE
POISONOUS TAIL OF THE BENT BACK OCCLUSION HEADED TO OUR
NORTH...AND THUS WILL MAINTAIN THE CURRENT TIMING FOR OUR WARNINGS.
AFTER THE MON SYSTEM...IT LOOKS LIKE ANOTHER FAIRLY STRONG
DISTURBANCE MOVES THROUGH THE WATERS WED...AND A STRONGER LOW WED
NIGHT FOR SOLID GALES ON BOTH...POSSIBLY SOME LOW END STORM FORCE
GUSTS ON THE LATTER. THINGS LOOK TO CALM DOWN A BIT AFTER THIS.
KMD/SCHNEIDER
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM PDT
TUESDAY FOR NORTHERN OREGON CASCADES.
WINTER WEATHER ADVISORY FROM 1 AM TO 11 AM PDT TUESDAY FOR
CASCADES IN LANE COUNTY.
HIGH WIND WARNING UNTIL 5 PM PDT THIS AFTERNOON FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
HIGH SURF WARNING UNTIL 11 PM PDT THIS EVENING FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
WINTER STORM WARNING FROM 8 AM THIS MORNING TO 3 AM PDT TUE
FOR COAST RANGE OF NORTHWEST OREGON.
WIND ADVISORY FOR THE NORTH WILLAMETTE VALLEY UNTIL 1 PM.
WIND ADVISORY FOR THE CENTRAL AND SOUTHERN WILLAMETTE VALLEY
UNTIL 5 PM.
WA...WINTER STORM WARNING FROM 8 AM THIS MORNING TO 5 AM PDT TUE
FOR SOUTH WASHINGTON CASCADE FOOTHILLS-SOUTH WASHINGTON
CASCADES.
HIGH WIND WARNING UNTIL 5 PM PDT THIS AFTERNOON FOR SOUTH
WASHINGTON COAST.
HIGH SURF WARNING UNTIL 11 PM PDT THIS EVENING FOR SOUTH
WASHINGTON COAST.
WINTER STORM WARNING FROM 8 AM THIS MORNING TO 3 AM PDT TUE
FOR WILLAPA HILLS.
COASTAL FLOOD ADVISORY UNTIL 6 AM PDT EARLY THIS MORNING FOR
SOUTH WASHINGTON COAST.
WIND ADVISORY FOR CLARK COUNTY IN SW WASHINGTON UNTIL 1 PM.
PZ...HURRICANE FORCE WIND WARNING UNTIL 1 PM PDT THIS AFTERNOON FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 10 NM-WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
FROM 10 TO 60 NM.
HURRICANE FORCE WIND WARNING UNTIL 6 PM PDT THIS EVENING FOR
COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OR OUT 10 NM-
WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
11 AM PDT TUESDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
333 AM PDT SUN MAR 12 2012
.SYNOPSIS...A STRONG PACIFIC FRONT WILL BRING STRONG WINDS...HEAVY
RAIN AND MOUNTAIN SNOW TODAY. A SERIES OF SYSTEMS WILL MAINTAIN
DAMP AND COOL WEATHER THROUGH NEXT WEEK.
&&
.SHORT TERM...POTENT STORM SYSTEM TO DEAL WITH IN THE NEXT 24 HOURS.
THE VERY STRONG SUBSIDENCE SEEN IN WATER VAPOR PICTURES NEAR 46N
130W SUPPORTS THE EXPLOSIVE CYCLOGENESIS DEPICTED IN THE MODELS
BETWEEN 06Z AND 12Z THIS MORNING. MODELS CONTINUE TO SHOW A VERY
STRONG WIND FIELD ALOFT. THE TRIPLE POINT OF THE FRONT IS DIFFICULT
TO DETERMINE DEFINITIVELY...MAKING THE FORECAST OF LAND WINDS AND
SNOW LEVELS N OF THE WARM FRONT ALL THE MORE DIFFICULT. ISENTROPIC
LIFT WITH THIS SYSTEM IS MODEST...MODELS INDICATE MOST OF THE LIFT
COMING WITH STRONG FRONTOGENESIS...WHICH MEANS THE SPREAD OF HEAVY
PRECIPITATION INLAND WILL BE RELATIVELY SLOW AND TIED TO THE SURFACE
COLD/OCCLUDED FRONT. BEST GUESS IS THAT THE TRIPLE POINT IS HEADED
INLAND ON THE NORTH OR CENTRAL OREGON COAST...AND INLAND INTO THE S
WILLAMETTE VALLEY. THIS WOULD PUT THE POTENTIAL FOR STRONGEST
SURFACE WINDS ON THE OREGON COAST...ALTHOUGH CONVECTIVE GUSTS
FURTHER N SHOULD STILL EXCEED HIGH WIND CRITERIA AS EVIDENCED BY
OBSERVED WINDS OVERNIGHT AT CLATSOP SPIT AND CAPE DISAPPOINTMENT.
GIVEN MODELS CONTINUOUSLY PUTTING PEAK GUSTS OVER THE WATER ON THE
ORDER OF 75 KT TODAY... WILL BUMP UP PEAK GUSTS SOME ESP ON THE
OREGON COAST. INLAND WINDS ALSO PROBLEMATIC AS THE UW MM5-NAM MODEL
CONTINUES TO SUGGEST WIND ADVISORY TYPE GUSTS IN THE VALLEY TODAY.
GIVEN THE LACK OF A STRONG N-S SURFACE PRES GRADIENT THOUGH...AM
RELUCTANT TO ISSUE ANY SORT OF INLAND ADVISORIES FOR WIND UNTIL WILL
SEE SOME EVIDENCE OF SUCH WINDS DEVELOPING IN SURFACE OBSERVATIONS.
AT THE END OF THE DAY...00Z TUE...WRF-GFS SUGGESTS TAIL END OF A
BENT BACK OCCLUSION BRINGING ANOTHER SHOT OF WINDS TO THE S WA AND N
OREGON COAST. AS THIS APPEARS TO BE A NEW DEVELOPMENT NOT SUPPORTED
BY OTHER MODELS...WILL NOT ACT ON THIS FEATURE BUT IT DOES BEAR
WATCHING TODAY.
SURFACE OBSERVATIONS SUGGEST SNOW LEVEL ON THE ORDER OF 1500-2000
FEET EARLY THIS MORNING. WITH LOW LEVEL OFFSHORE FLOW...SNOW LEVELS
LOOK UNLIKELY TO WARM MUCH UNTIL MAYBE THE END OF THE DAY WHEN WIND
FINALLY PICKS UP AN ONSHORE COMPONENT. WITH FAIRLY HEAVY
PRECIPITATION RATES EXPECTED WITH THE FRONT...POTENTIAL EXISTS FOR
THE N COAST RANGE AND WILLAPA HILLS TO SEE LOWERING SNOW LEVELS IN
THE HEAVY PRECIPITATION THIS AFTERNOON AND EVENING. AS SUCH...WILL
GO FOR A WINTER STORM WARNING IN THE COAST RANGE AND WILLAPA HILLS
TODAY INTO TONIGHT...MAINLY FOR AREAS ABOVE 2000 FT. THE S WA
CASCADES AND FOOTHILLS WILL BENEFIT FROM PROLONGED GOOD OROGRAPHICS
DUE TO THE STRONG SSW LOW LEVEL FLOW...SO WILL ALSO BUMP THOSE AREAS
UP TO A WINTER STORM WARNING FOR TODAY AND TONIGHT.
THE PRECIPITATION WILL TURN TO SHOWERS BEHIND THE FRONT TUE AS
COLDER AIR MOVES IN. NAM BUFR SOUNDINGS SUGGEST SNOW LEVELS BELOW
1000 FT...BUT GIVEN ONSHORE FLOW WITH 1000-500 MB THICKNESS OF 522
DM AND H8 TEMPS ON THE ORDER OF -6 C...WILL BOTTOM OUT SNOW LEVELS
AT 1000 FT IN THE SHOWERS. SHOWERS WEAKEN WITH WEAKENING ONSHORE
FLOW TUE NIGHT...THEN CHANCE FOR PRECIPITATION INCREASE AGAIN ON WED
IN THE NW PART OF THE AREA AS MOIST WARM AIR ADVECTION KICKS IN
AHEAD OF THE NEXT SYSTEM.
.LONG TERM...NO CHANGES...PREVIOUS DISCUSSION FOLLOWS.
IT CONTINUES TO LOOK LIKE COOL AND WET WEATHER WILL DOMINATE THE
EXTENDED FCST PERIOD. A STRONG UPPER LEVEL JET AND LONGWAVE
TROUGHING PATTERN WILL REMAIN OVER THE EASTERN PAC AT LEAST
THROUGH NEXT WEEKEND. MODEL AGREEMENT IS FAIRLY GOOD THAT WARM
FRONTAL RAIN ALONG WITH GUSTY COASTAL WINDS WILL SPREAD INTO THE
FCST AREA DURING THE SECOND HALF OF WED. AN APPROACHING SHORTWAVE
WILL BRING EVEN WETTER CONDITIONS ON THU. SNOW LEVELS WILL REMAIN
FAIRLY HIGH ON WED AND THU...WITH SIGNIFICANT SNOWFALL ACCUMULATIONS
CONFINED TO THE HIGHER ELEVATIONS OF THE CASCADES. HEADING INTO NEXT
WEEKEND...THE EXTENDED MODELS CONTINUE TO SUGGEST THAT THE UPPER
LEVEL TROUGHING WILL DIG FURTHER SOUTH...WITH THE BULK OF THE ENERGY
FOCUSED IN NORTHERN CALIFORNIA. THIS WOULD LEAVE US IN A SHOWERY
PATTERN WITH SNOW LEVELS DOWN INTO THE COAST RANGE AND CASCADE
FOOTHILLS. JFP
&&
.AVIATION...CIGS WILL GENERALLY BE MVFR ALONG THE COAST..THEN DROP
TO IFR THIS MORNING AT TIMES...EVEN LIFR IN HEAVY RAIN LATE THIS
MORNING THIS AFTERNOON. BIG ISSUE WILL BE THE VERY STRONG WINDS
EXPECTED IN THE MORNING ALONG THE NORTH COAST...LINGERING INTO THE
AFTERNOON SOUTH NEAR NEWPORT. SOUTH WIND GUSTS TO 50 KT AND HIGHER
ARE POSSIBLE.
INLAND WINDS WILL INCREASE AROUND 12Z ESPECIALLY ALOFT STRONG
WINDS IN THE LOWER LEVELS AFTER 12Z MON...GENERALLY BELOW 900
MB...WILL LIKELY RESULT IN LOW-LEVEL WIND SHEAR...MAINLY SPEED
SHEAR OF +/- 15 KT OR MORE..AT MOST OF THE TAF SITES...BUT THE
BEST SHOT AT THE KPDX/KTTD TAF SITES WHERE LESS MIXING MAY BE
OCCURRING. WE WILL TAKE A CLOSER LOOK AT THIS TO SEE IF IT IS
NEEDED...BUT FLIERS SHOULD AWARE THAT WHETHER THESE WINDS SURFACE
OR NOT...WINDS AT 1000-1500 FT WILL BE IN THE 40-50 KT RANGE.
EXPECT MOST OF THE INLAND PRECIP TO HOLD OFF UNTIL MID
MORNING...WITH VFR UNTIL THEN...THEN MVFR...WITH IFR IN MODERATE
TO HEAVY RAIN THIS EVENING. WE MAY SEE SOME SNOW MIXED IN DOWN TO
LOW LEVELS LATER THIS EVENING OR OVERNIGHT...BUT CONFIDENCE LOW
RIGHT NOW.
KPDX AND APPROACHES...EXPECT PRIMARILY VFR THROUGH AT LEAST 12Z
MON. LOW- LEVEL WIND INCREASES AFTER 12Z MON...FOR A THREAT OF
LOW-LEVEL WIND SHEAR (SPEED SHEAR) OF AT LEAST +/- 15 KT. EXPECT
CIGS TO REMAIN VFR UNTIL MIDDAY WHEN CIGS WILL LOWER AS THE FRONT
APPROACHES. IFR IS POSSIBLE IN MODERATE TO HEAVY RAIN THIS
EVENING. KMD
&&
.MARINE...SEAS ARE COMING UP VERY QUICKLY THIS MORNING WITH BUOY
29 NOW UP TO 22 FT...AND THE ASTORIA CANYON BUOY WHICH IS SLIGHTLY
FURTHER OFFSHORE AT 23 FT...AND OVERALL SWAN/ENP GUIDANCE IS NOT
TOO FAR OFF THE MARK. BUOY 5...ABOUT 300 NM OFFSHORE HIT ITS
LOWEST PRESSURE OF 974 MB AT 9Z...AND NOW IS ALREADY BACK UP TO
978 MB AS THE LOW HEADS NORTH INSIDE OF 130 W. WE HAVE HAD PEAK
WINDS SO FAR TO 51 KT IN THE OUTER WATERS...BUT AN IMPRESSIVE
GRADIENT IS DRAPED OVER THE WATERS WITH PRESSURES AT THE COAST
GENERALLY STILL AT 1000 MB OR HIGHER.
THE HRRR MODEL...AMONG OTHERS...ARE STILL SHOWING HURRICANE FORCE
GUSTS UP TO 75KT OVER THE COASTAL WATERS. IT IS ADVERTISING 64 KT
GUSTS AS OF NOW...AND WE HAVE HAD PEAK WINDS AT BUOY 29 (20 NM
OFFSHORE) OF 51 KT...54 KT AT BUOY 89 (70 NM OFFSHORE) SO IT MAY BE
RUNNING HIGH...POSSIBLY A TIMING ISSUE...OR THE BUOY IS STRUGGLING TO
REPORT HIGHER GUSTS. GIVEN THAT THIS CYCLOGENESIS BOMB...SEEN IN THE
BUOY 5 OBS DROPPING 25 MB IN 8 HOURS...EXPECT THAT WE WILL SEE VERY
HIGH END STORM FORCE WINDS AND SOME HURRICANE FORCE WINDS TO
MAINTAIN THE MESOSCALE MODEL ADVERTISED WIND GUSTS.
HAVE MAINTAINED THE GOING FORECAST FOR SEAS GETTING INTO THE UPPER
TO 20S TO LOW 30S AS THE SWAN ADVERTISES...AS SEAS ARE COMING UP
FAST. THE MAJORITY OF THE ENERGY WITH THESE WAVES WILL BE WITH THE
SHORTER PERIOD 12 SECOND WAVES. ALTHOUGH THE DIRECTION WILL BE
FROM THE SOUTHWEST WE ARE STILL AT THE LOW END FOR A HIGH SURF
WARNING. THE TIDAL ANOMALIES HAVE BEEN RUNNING 1 TO 2 FEET AND
EXPECT THIS TO REACH 3 FT TOMORROW MORNING. WITH THE HIGH TIDES
AROUND 10Z TO 12Z...THIS HAS PUT THE SOUTH WASHINGTON COAST INTO
COASTAL FLOOD ADVISORY CATEGORY FOR MINOR TIDAL OVERFLOW FOR A FEW
HOURS AROUND HIGH TIDE THIS MORNING...SET AROUND 430 AM AT TOKE
POINT. WIDESPREAD COASTAL FLOODING SHOULD NOT BE A CONCERN...AS THE
TIMING OF THE HIGHEST SWELL IS EXPECTED TO BE WHEN THE TIDE IS
FALLING AND DURING LOW TIDE. DURING THE SECOND HIGH TIDE SEAS SHOULD
NOT BE HIGH ENOUGH TO PRODUCE COASTAL FLOODING. SEAS WILL REMAIN
ABOVE 20 FEET THROUGH LATE MONDAY AFTERNOON...THEN FALL OFF
OVERNIGHT MONDAY.
AN DESPITE THE UW NAM ADVERTISING 50 KT WORKING ITS WAY BACK INTO
THE N OR/S WA COAST THIS AFTERNOON...IT WAS THE ONLY MODEL DOING
SO AND ONLY IN ITS CURRENT RUN. AT THIS TIME MOST MODELS KEEP THE
POISONOUS TAIL OF THE BENT BACK OCCLUSION HEADED TO OUR
NORTH...AND THUS WILL MAINTAIN THE CURRENT TIMING FOR OUR WARNINGS.
AFTER THE MON SYSTEM...IT LOOKS LIKE ANOTHER FAIRLY STRONG
DISTURBANCE MOVES THROUGH THE WATERS WED...AND A STRONGER LOW WED
NIGHT FOR SOLID GALES ON BOTH...POSSIBLY SOME LOW END STORM FORCE
GUSTS ON THE LATTER. THINGS LOOK TO CALM DOWN A BIT AFTER THIS.
KMD/SCHNEIDER
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM PDT
TUESDAY FOR NORTHERN OREGON CASCADES.
WINTER WEATHER ADVISORY FROM 1 AM TO 11 AM PDT TUESDAY FOR
CASCADES IN LANE COUNTY.
HIGH WIND WARNING UNTIL 5 PM PDT THIS AFTERNOON FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
HIGH SURF WARNING UNTIL 11 PM PDT THIS EVENING FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
WINTER STORM WARNING FROM 8 AM THIS MORNING TO 3 AM PDT TUE
FOR COAST RANGE OF NORTHWEST OREGON.
WA...WINTER STORM WARNING FROM 8 AM THIS MORNING TO 5 AM PDT TUE
FOR SOUTH WASHINGTON CASCADE FOOTHILLS-SOUTH WASHINGTON
CASCADES.
HIGH WIND WARNING UNTIL 5 PM PDT THIS AFTERNOON FOR SOUTH
WASHINGTON COAST.
HIGH SURF WARNING UNTIL 11 PM PDT THIS EVENING FOR SOUTH
WASHINGTON COAST.
WINTER STORM WARNING FROM 8 AM THIS MORNING TO 3 AM PDT TUE
FOR WILLAPA HILLS.
COASTAL FLOOD ADVISORY UNTIL 6 AM PDT EARLY THIS MORNING FOR
SOUTH WASHINGTON COAST.
PZ...HURRICANE FORCE WIND WARNING UNTIL 1 PM PDT THIS AFTERNOON FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 10 NM-WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
FROM 10 TO 60 NM.
HURRICANE FORCE WIND WARNING UNTIL 6 PM PDT THIS EVENING FOR
COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OR OUT 10 NM-
WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
11 AM PDT TUESDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1246 PM CDT MON MAR 12 2012
.DISCUSSION...
ISSUED 1020 AM CDT MON MAR 12 2012
UPDATED THE FORECAST TODAY TO INCREASE CHANCES OF SHOWERS AND
ADDED ISOLATED THUNDERSTORMS LATE THIS MORNING AROUND GALESBURG
IN KNOX COUNTY. ALSO INCREASED WIND SPEEDS TODAY AS SOUTH WINDS
15 TO 25 MPH AND GUSTS 30 TO 40 MPH TURN SW DURING THE AFTERNOON.
ANOTHER MINOR ADJUSTMENT TO THE FORECAST WAS TO EXPAND THE SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON A BIT FURTHER
SOUTH (TO JUST SOUTH OF I-74).
FAIRLY STRONG 543 DM 500 MB LOW WAS DEEPENING OVER THE EASTERN
MN/IA BORDER AS IT WAS TRACKING NE. AS THE SURFACE A STRONG 990 MB
LOW PRESSURE WAS ALONG THE NORTHERN ALBERTA/SASKATCHEWAN PROVINCE
LINE WITH A FRONTAL BOUNDARY EXTENDING SOUTHWARD ACROSS THE
CENTRAL PLAINS OVER CENTRAL NE/KS INTO NW TX. 1032 MB HIGH
PRESSURE WAS OFF THE EAST COAST. BREEZY SOUTH WINDS OF 15 TO 25
MPH AND GUSTS TO AROUND 30 MPH OVER CENTRAL IL BETWEEN THESE
WEATHER FEATURES. THIS HAD BROUGHT IN MILD AND MOIST AIR INTO IL
WITH DEWPOINTS IN THE MID TO UPPER 50S AND TEMPS AT 10 AM IN THE
LOWER 60S. RADAR MOSAIC SHOWS A STRENGTHENING BAND OF SHOWERS WITH
A FEW EMBEDDED THUNDERSTORMS IN NW IL NORTH OF GALESBURG INTO EAST
CENTRAL IA AND SOUTHERN WI AND MOVING NE.
12Z MODELS TAKE UPPER LEVEL LOW PRESSURE NE INTO WESTERN LAKE
SUPERIOR BY SUNSET WHILE THE FRONTAL BOUNDARY IN THE CENTRAL
PLAINS WEAKENS AS IT DRIFTS EASTWARD TOWARD THE MS VALLEY. INSTABILITY
INCREASES ACROSS EASTERN IL THIS AFTERNOON WITH CAPES INCREASING
TO 1000-1500 J/KG BY 21Z/4 PM EAST OF I-55. UPPER LEVEL DYNAMICS
PASS ACROSS NORTHERN IL SO BEST CHANCES OF SHOWERS AND
THUNDERSTORMS WILL BE OVER NE IL AROUND CHICAGO METRO. SPC HAS A
SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON FROM PONTIAC NE
WITH GENERAL RISK OF THUNDERSTORM SW TO ALONG I-74 CORRIDOR.
ISOLATED SHOWERS AND THUNDERSTORMS EXPECTED THIS AFTERNOON ALONG
AND NE OF I-74 AND A FEW STORMS COULD BECOME STRONG WITH HAIL AND
GUSTY WINDS. SPC HAS 2% RISK OF TORNADOES AND 5% RISK OF LARGE
HAIL AND DAMAGING WIND GUSTS NE OF BLOOMINGTON AND DANVILLE THIS
AFTERNOON. TEMPS TO CLIMB ANOTHER 10 DEGREES INTO THE LOWER TO
MIDDLE 70S AS MOSTLY CLOUDY SKIES BECOME PARTLY TO MOSTLY SUNNY
THIS AFTERNOON.
HUETTL
&&
.AVIATION...
ISSUED 1245 PM CDT MON MAR 12 2012
MVFR BROKEN CEILINGS OF 2.5-3K FT ALONG I-74 TAF SITES OF PIA...
BMI AND CMI. ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE ALONG
I-74 THIS AFTERNOON AND SINCE QUITE ISOLATED IN NATURE...JUST
CARRIED A CB WITH BETTER CHANCES OF THUNDERSTORMS IN NE IL. THIS
DUE TO 544 DM 500 MB LOW NEAR THE MN/WI BORDER THAT MOVES INTO
WESTERN LAKE SUPERIOR BY 00Z/7 PM EALRY THIS EVENING. STRONG SSW
WINDS OF 15 TO 25 KTS WITH GUSTS OF 25 TO 35 KTS TO DIMINISH UNDER
10 KTS AND TURN WSW AFTER SUNSET. HAVE MVFR VISIBILITIES WITH
LIGHT FOG OF 4-5 MILES POSSIBLE FROM 09Z-14Z (4-9 AM) TUE
MORNING. FAIR CONDITIONS EXPECTED TUE WITH LIGHT WINDS AS WEAK
HIGH PRESSURE RIDGE SETTLES OVER IL BY 18Z/1 PM TUE.
HUETTL
&&
.PREV DISCUSSION...
ISSUED 227 AM CDT MON MAR 12 2012
UPPER LOW CLEARLY EVIDENT IN INFRARED AND WATER VAPOR SATELLITE
IMAGERY...CENTERED OVER EASTERN NEBRASKA. DRY SLOT HAS PUSHED
ACROSS MUCH OF THE CWA...REDUCING THE RAIN TO SCATTERED SHOWERS.
THE EXTENT OF THE LINGERING RAIN IS THE INITIAL FORECAST CONCERN...
BUT THE PRIMARY FOCUS IS THE EXTENDED PERIOD OF ABNORMALLY WARM
WEATHER FOR MID MARCH.
SHORT TERM...TODAY THROUGH WEDNESDAY...
00Z MODELS ARE IN GOOD AGREEMENT WITH TRACKING THE LOW INTO WEST
CENTRAL WISCONSIN BY LATE MORNING...THEN TO THE UPPER PENINSULA OF
MICHIGAN BY EARLY EVENING. LINGERING SHOWERS ACROSS THE EASTERN
CWA SHOULD BE OUT OF THE AREA BY MID TO LATE MORNING. NORTHERN CWA
IS A BIT MORE QUESTIONABLE...AS NAM AND HRRR BOTH SHOWING SOME
INSTABILITY SHOWERS REFORMING IN THE COLDER AIR ALOFT. BOTH MODELS
SHOWING THE BEST RAIN CHANCES IN OUR NORTHERN CWA IN THE MORNING...
BUT WILL LINGER SOME SLIGHT CHANCES THERE INTO THE AFTERNOON AS
WELL.
UPPER RIDGING ACROSS THE CENTRAL U.S. BEGINS IN EARNEST LATER
TONIGHT AND PERSISTS MUCH OF THE WEEK. START OF THE WARMING TREND
BEGINS TODAY AND BY WEDNESDAY...WE WILL LIKELY BE SEEING 80 DEGREE
TEMPERATURES IN SEVERAL LOCATIONS. MOST RECORD HIGHS ON WEDNESDAY
ARE IN THE 74-78 RANGE...WITH SOME LOWER 80S ACROSS THE
SOUTHEAST...SO WILL LIKELY SEE SEVERAL RECORDS FALL. MODELS ARE
SOMEWHAT INCONSISTENT WITH SHOWER/THUNDERSTORM POTENTIAL ON
WEDNESDAY WITH THE RIDGE IN PLACE...BUT RAIN CHANCES INCREASE
WEDNESDAY NIGHT AS A WEAKENING BOUNDARY DROPS INTO THE AREA.
LONG TERM...THURSDAY THROUGH SUNDAY...
850 MB TEMPERATURES REMAIN CLOSE TO +12C THROUGH THE PERIOD...AS
THE UPPER RIDGE GRADUALLY SHIFTS TO THE EAST COAST. HOWEVER...CLOUD
COVER WILL BE MORE OF A FACTOR...AS WEAK WAVES IN THE UPPER FLOW
BRING PERIODIC CHANCES OF SHOWERS AND STORMS. HAVE KEPT HIGHS WELL
INTO THE 70S THROUGH THE PERIOD...BUT HAVE NOT GONE AS AGGRESSIVE
AS WEDNESDAY DUE TO THIS ISSUE.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
655 PM EDT MON MAR 12 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISOLATED SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH
TONIGHT...AS A WEAK FRONTAL BOUNDARY PASSES THROUGH THE LOWER GREAT
LAKES. HIGH PRESSURE WILL THEN BUILD IN THROUGH MIDWEEK...BRINGING
DRY AND UNSEASONABLY WARM WEATHER. CHANCES FOR SHOWERS AND
THUNDERSTORMS RETURN BEGINNING WEDNESDAY NIGHT AND CONTINUING INTO
THE WEEKEND...AS MOISTURE INCREASES AND A FRONTAL BOUNDARY BECOMES
NEARLY STATIONARY NORTH OF THE FORECAST AREA.
&&
.NEAR TERM /REST OF TODAY/...
PRECIP IS ISOLATED IN NATURE AT THIS TIME WITH ONLY SOME LIGHT
SHOWERS ACROSS THE FAR SOUTHERN COUNTIES. HOWEVER...WILL KEEP
CHANCE POPS IN GRIDS THROUGH EARLY AFTERNOON. DRY SLOT WILL THEN
WORK ITS WAY INTO FORECAST AREA PUTTING AN END TO THE PRECIP
ACROSS MOST OF THE AREA. DID LEAVE SLIGHT CHANCE POPS ACROSS THE
NORTHERN PORTIONS IN CASE ANY OF THE PRECIP OVER NORTHERN INDIANA
MAKES ITS WAY INTO THOSE COUNTIES.
TEMPERATURES ACROSS CENTRAL INDIANA ARE CURRENTLY IN THE UPPER
50S/LOW 60S. NO CHANGES TO FORECASTED HIGHS. UPPER 60S ARE
EXPECTED ACROSS THE EASTERN PORTIONS WHERE CLOUD COVER AND PRECIP
WILL LINGER LONGEST. ELSEWHERE...HIGHS SHOULD CLIMB INTO THE LOW
70S AFTER DRY SLOT MOVES IN AND SUN BREAKS OUT THIS AFTERNOON.
UPDATED GRIDS HAVE BEEN SENT.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
THE MAIN FOCUS OF THIS SHORT TERM FORECAST WILL CONTINUE TO REMAIN
ON THE UNSEASONABLY WARM TEMPERATURES AND POP CHANCES TOWARD THE END
OF THE SHORT TERM TIMEFRAME.
THE PERIOD BEGINS WITH AN UPPER LOW OVER THE WESTERN GREAT LAKES
TREKKING TO THE EAST NORTHEAST WITH ITS ASSOCIATED SURFACE FRONT
FROM NORTHWEST INDIANA DOWN THROUGH CENTRAL ILLINOIS. THE MAJORITY
OF THE PRECIPITATION WITH THIS SYSTEM WILL HAVE PUSHED FURTHER EAST
WITH THE FORECAST AREA UNDER THE INFLUENCE OF THE DRY SLOT.
HOWEVER...MODEL GUIDANCE CURRENTLY ILLUSTRATES LOW LEVEL MOISTURE
HANGING ON ESPECIALLY ACROSS THE SOUTHWESTERN HALF OF THE FORECAST
AREA...AS EVIDENCED BY LOW CONDENSATION PRESSURE DEFICITS AT 925 MB
AND THE 1000-925 MB LAYER. KEPT AND EXPANDED SOUTHWARD THE SLIGHT
CHANCE POP FOR TONIGHT AS THE FRONT MAKES ITS WAY THROUGH THE AREA.
CONFIDENCE NOT HIGH THAT RAIN WILL MAKE IT INTO THE FORECAST AREA.
UPPER RIDGE AND SURFACE HIGH PRESSURE MOVES TOWARD THE AREA TUESDAY
AND TUESDAY NIGHT...BRINGING DRY CONDITIONS TO THE OHIO VALLEY.
UNSEASONABLY WARM TEMPERATURES ARE EXPECTED TO CONTINUE THROUGH THE
ENTIRE SHORT RANGE...WITH A GRADUAL WARMING ON WEDNESDAY AS THE SFC
HIGH PRESSES EAST AND S/SW WINDS RETURN. NOT MUCH CHANGE TO TEMPS AS
THEY MATCHED UP WELL WITH MOS GUIDANCE. STAYED ON THE HIGH SIDE OF
ENSEMBLE MOS SPREAD ON WEDNESDAY AND AFTER.
WITH MINOR UPPER LEVEL DISTURBANCES PUSHING TOWARD THE FORECAST AREA
UNDER SOUTHWEST FLOW ALOFT...POPS MAKE A RETURN TO THE FORECAST AREA
WEDNESDAY NIGHT...OWING TO INCREASING MOISTURE AND ISENTROPIC LIFT
AOA THE 300-305K SFCS. INCREASING GULF MOISTURE AND AT LEAST MODEST
INSTABILITY IS EXPECTED WEDNESDAY NIGHT THROUGH THURSDAY.
THUS...KEPT THUNDER GOING IN WX GRIDS. ON THURSDAY AFTN...THE NAM
FCST SOUNDINGS HAS 2500-3000 J/KG OF CAPE FORECAST WITH A MEAGER
20KT 0-6KM BULK SHEAR...WHILE THE GFS IS LESS BULLISH WITH THE CAPE
AOA 900 J/KG. IF THE NAM PANS OUT AND CONVECTIVE TEMPERATURES ARE
REACHED...ISOLATED SEVERE MAY BE POSSIBLE ON THURSDAY. LARGE HAIL
BEING THE MAIN THREAT WITH A FREEZING LEVEL FROM 9-10K. RIGHT NOW
CONFIDENCE IS LOW IN THIS SCENARIO...AS MODEL FORECAST SOUNDINGS
DISAGREE. WILL CONTINUE TO MONITOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS INDICATE AN UPPER AIR DISTURBANCE WILL BE MOVING ACROSS OUR
REGION EARLY IN THE EXTENDED PERIOD AND WILL AFFECT OUR
WEATHER...ESPECIALLY THURSDAY NIGHT. WILL MENTION LIKELY POPS
HERE. OTHERWISE IT IS HARD TO KEY ON ANYTHING ONE SYSTEM FRIDAY
THROUGH SATURDAY EXCEPT MODELS HAVE US UNDER A WARM HUMID AIRMASS
AND CONTINUALLY ARE PRODUCING QPF ACROSS OUR REGION AND WILL
CONTINUE CHANCE POPS HERE..
ENSEMBLES AMPLIFY THE UPPER RIDGE STRONGLY ACROSS OUR REGION EARLY
NEXT WEEK AS A STRONG UPPER TROUGH MOVES INTO THE WESTERN U.S. WILL
CONTINUE WITH A DRY FORECAST FOR SUNDAY AND I HAVE DOUBTS ABOUT ANY
PRECIP MONDAY GIVEN THE STRENGTH OF THE UPPER HIGH. FOR NOW WILL
ONLY MENTION 20 PERCENT POPS FOR MONDAY.
AS FAR AS TEMPERATURES ARE CONCERNED...FOLLOWED ALL BLEND NUMBERS
EARLY ON AND THEN WENT WITH A MIX OF HPC AND ALL BLEND NUMBERS FROM
THE WEEKEND ON. I SUSPECT ALL BLEND MAY BE A BIT COOL DURING THE
DAY AND A BIT TOO WARM AT NIGHT SUNDAY AND MONDAY GIVEN THAT THE
AIRMASS WILL BE DRYING OUT SOME.
&&
.AVIATION /DISCUSSION FOR 130000Z TAF ISSUANCE/...
WIND GUSTS OUT OF THE SOUTHWEST OF 20-30 KTS SHOULD BE DROPPING
OFF AROUND THE TIME OF ISSUANCE BUT MAY SEE ISOLATED GUSTS HANG
ON THROUGH 0-1Z BEFORE DROPPING OFF COMPLETELY. SUSTAINED WINDS
WILL DROP DURING THE NIGHT TO AROUND 5 - 10KTS BY 6Z. WHILE MAV
SHOWS ONLY A COUPLE OF HOURS OF MVFR MAINLY BASED ON VISIBILITIES
OVERNIGHT...MET NUMBERS BRING IN MVFR AND THEN AROUND 6 HOURS OF
IFR CEILINGS. BOTH NAM AND RUC FORECAST SOUNDINGS SUPPORT THE
INCLUSION OF IFR...AND VSREFS SHOW A MEAN OF MVFR CEILINGS OVER
THE ENTIRE AREA AFTER ABOUT 3-4Z WITH A HIGH PROBABILITY OF IFR
CEILINGS DEVELOPING AT LEAST OVER THE WEST AFTER 6Z. WILL FAVOR A
PREVAILING MVFR SOLUTION WITH PERHAPS THE INCLUSION OF A FEW HOURS
OF TEMPO IFR AT KIND AND KBMG BASED ON THE MORE NUMEROUS
PESSIMISTIC SOLUTIONS. WILL KEEP THE WESTERN SITES OUT OF THE IFR
AS CEILINGS MAY NOT BUILD BACK THAT FAR. CEILINGS SHOULD BE COMING
BACK UP TO VFR BETWEEN 12 AND 15Z. ON ANOTHER NOTE...MODELS ARE
SHOWING SOME POSSIBILITY THAT KLAF COULD SEE A SHOWER OR
THUNDERSTORM TONIGHT IN THE 3-6Z TIMEFRAME AT THE TAIL END OF A
SQUALL LINE HEADING THROUGH MICHIGAN. STILL LOOKS LIKE PROBABILITY
IS LOW ENOUGH TO LEAVE OUT OF FORECAST AT THIS TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MRD
NEAR TERM...TDUD
SHORT TERM...MRD
LONG TERM....JH
AVIATION...CP
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
310 PM CDT MON MAR 12 2012
.SYNOPSIS...
12Z UA ANALYSIS HAD A 700MB LOW OVER WESTERN MINNESOTA WITH SEVERAL
TROFS RUNNING FROM THE WESTERN GREAT LAKES BACK INTO THE PLAINS. A
MODERATELY STRONG LLJ RAN FROM THE OKLAHOMA PANHANDLE INTO THE GREAT
LAKES. SATELLITE TRENDS SHOWS A VORT MAX MOVING FROM NORTHERN
MISSOURI INTO NORTHERN ILLINOIS WHILE THE MAIN VORT MAX MOVES INTO
NORTHERN WISCONSIN. RADAR SHOWS SPRINKLES OVER THE AREA WITH SOME
LOW CONVECTION OVER NORTHEAST ILLINOIS.
18Z SFC ANALYSIS HAS A WEAK LOW NEAR KDLH WITH A WARM FRONT RUNNING
SOUTHEAST TO NEAR DETROIT. A COLD FRONT RAN FROM THE LOW SOUTH TO
KUIN. DEW POINTS WERE IN THE 50S AND 60S OVER THE GREAT LAKES AND
LOWER MISSISSIPPI VALLEY WITH 30S AND 40S OVER MUCH OF THE PLAINS.
&&
.SHORT TERM...TONIGHT AND TUESDAY...
REFER TO THE CLIMATE SECTION BELOW FOR RECORD HIGHS FOR MARCH 13TH
AND 14TH.
CURRENT OBSERVATIONS THROUGH 20Z COMBINED WITH RECENT RUC TRENDS
INDICATE THE WINDOW OF OPPORTUNITY FOR ANY NEW CONVECTION IS
CLOSING. RADAR INDICATES SPRINKLES WITH SOME VERY MINOR SHOWERS OVER
THE SOUTHEAST HALF OF THE CWFA BUT RUC TRENDS INDICATE THE
INSTABILITY NEEDED TO GET ANYTHING STRONGER GOING WILL END BY 2130Z.
THUS SPRINKLES WITH PERHAPS A FEW SHRA WILL CONTINUE THROUGH SUNSET
WITH POSSIBLY AN ISOLD TSRA IN THE FAR EASTERN/SOUTHEASTERN CWFA.
SATELLITE TRENDS INDICATE THE CLOUDS ARE TAKING ON A MORE CELLULAR
NATURE AND WILL SLOWLY DISSIPATE WITH SUNSET.
SO A CLEARING TREND WILL OCCUR TONIGHT AS THE STORM SYSTEM MOVES
INTO CANADA. HIGH PRESSURE BUILDING INTO THE CWFA LATE TONIGHT WILL
RESULT IN LIGHT WINDS WHICH SHOULD ALLOW TEMPERATURES TO BECOME
CHILLY BUT STILL ABOVE NORMAL.
THE HIGH WILL INITIALLY LIMIT MIXING ON TUESDAY UNTIL IT MOVES EAST
OF THE AREA. RETURN FLOW DEVELOPING BY MID DAY COMBINED WITH THE
STRONG MARCH SUN WILL ALLOW TEMPERATURES TO CLIMB WELL ABOVE NORMAL.
THE NORTHERN THIRD OR SO OF THE CWFA SHOULD REACH THE UPPER 60S WITH
70 TO 75 ELSEWHERE. ..08..
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY...
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...BOTH SFC AND UPPER RIDGE
AXIS WILL MIGRATE OFF TO THE EAST OF THE CWA INTO WED MORNING
ALLOWING RETURN FLOW TO INCREASE LATE TUE NIGHT FOR NON-DIURNAL
TEMP CURVES. LOWS WILL PROBABLY OCCUR FROM 03Z-07Z WED BEFORE STEADY
TO SLOW RISE TREND BEGINS. AS SFC FRONT TRIES TO SAG TOWARD THE CWA
FROM THE NORTHWEST...THE CWA WILL BECOME UNDER FULL INFLUENCE OF
WARM THRUST. ONLY THE WET BIASED 12Z GFS BREAKS OUT PRECIP ON WED
BEFORE 00Z THU AND WILL REMOVE ANY DAYTIME POPS. MORE INSOLATION AND
EXTENT OF CURRENTLY PROGGED THERMAL PROFILES SUGGEST HIGHS IN THE
MID TO UPPER 70S ON WED WITH THE SHOT AT A FEW 80S...ALL OF WHICH
WILL BE RECORD HIGH TERRITORY FOR ALL CLIMATE SITES FOR MARCH 14TH.
FLATTENING RIDGE-RIDING VORT WILL COMBINE WITH LLVL MOISTURE
CONVERGENCE ALONG THE INCOMING FRONT FOR A CHANCE AT SOME NOCTURNAL
SHOWERS AND THUNDERSTORMS WED NIGHT. IF A STORM COULD GET GOING IN
THE LOCAL AREA WED AFTERNOON AND EARLY EVENING AND BECOME SOMEWHAT
ORGANIZED...FCST SOUNDINGS SUGGEST A POTENTIAL FOR A SVR STORM WITH
LARGE HAIL AND DAMAGING WIND...BUT AGAIN A TRIGGER DOES NOT APPEAR
UNTIL LATER THAT NIGHT. ALSO THESE SVR PARAMETERS ARE BEING
ADVERTISED ON THE GFS AND ESPECIALLY THE NAM FCST SOUNDINGS WHICH MAY
AGAIN BE OVERDOING BOUNDARY LAYER MOISTURE.
THURSDAY AND FRIDAY...FLATTENING NON-SENSIBLE FLOW ACRS THE
MIDWEST...UNSEASONABLY MILD REGIME CONTINUES WITH LITTLE FOCUS FOR
ORGANIZED CONVECTION. WILL KEEP LOW POPS FOR WDLY SCTRD SHOWERS OR
THUNDERSTORMS POPPING UP IN THE AFTERNOON CAPES. HIGHS IN THE MID TO
UPPER 70S BOTH DAYS AS MAY ARRIVES EARLY.
SATURDAY THROUGH MONDAY...MOST 12Z RUN MEDIUM RANGE SOLUTIONS AND
LATEST ENSEMBLES SUGGEST PATTERN TO BECOME HIGH AMPLITUDE SINE WAVE
PATTERN ACRS THE CONUS...WITH THE MID MS RVR VALLEY STUCK IN THE
MIDDLE FOR THE REST OF THE EXTENDED. WARM MOIST CONVEYOR UP OFF THE
WESTERN GULF TO CONTINUE TO FLOW UP INTO THE REGION TO FUEL POSSIBLE
SHOWER AND THUNDERSTORM ACTIVITY...BUT AGAIN NO REAL SYNOPTICS SCALE
FEATURES TO SUGGEST MORE ORGANIZATION TO THE CONVECTION EVIDENT AT
THIS TIME THROUGH AT LEAST MON NIGHT...POSSIBLY NOT UNTIL MID NEXT
WEEK AS HIGH AMPLITUDE PATTERN SLOW TO MOVE. THUS WILL KEEP LOW
DIURNAL CHANCES FOR WDLY SCTRD UNORGANIZED CONVECTION IN MAINLY
DAYTIME HEATING WHICH MAY LEAD TO HIGHS IN THE MID TO UPPER 70S
EVERY DAY. ..12..
&&
.AVIATION...
MVFR TO VFR CONDITIONS WILL CONTINUE THROUGH 00Z/13 AS A STORM
SYSTEM MOVES INTO CANADA. A DISTURBANCE MOVING FROM MISSOURI INTO
ILLINOIS MIGHT ALLOW SOME SHRA OR ISOLD TSRA TO DVLP EAST OF THE
MISSISSIPPI RIVER PRIOR TO 00Z BUT WILL NOT AFFECT KMLI/KBRL. HIGH
PRESSURE BUILDING INTO THE MIDWEST AFTER 00Z/13 WILL ALLOW VFR
CONDITIONS TO SLOWLY DVLP THROUGH 12Z/13. ..08..
&&
.CLIMATE...
RECORD HIGHS FOR MARCH 13TH...
BURLINGTON........77 IN 2007 AND OTHER YEARS
CEDAR RAPIDS......74 IN 2007
DUBUQUE...........71 IN 2007
MOLINE............77 IN 2007
RECORD HIGHS FOR MARCH 14TH...
BURLINGTON........76 IN 1995
CEDAR RAPIDS......75 IN 1995
DUBUQUE...........72 IN 1995
MOLINE............77 IN 1995
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
08/12
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
136 PM CDT MON MAR 12 2012
.UPDATE...
COLD POOL ALOFT COMBINED WITH CLOUD COVER IS HELPING TO SUPPRESS
TEMPERATURES. SATELLITE AND OBS TRENDS INDICATE THE PUSH OF WARM
TEMPERATURES WILL AT BEST JUST BRUSH THE FAR EASTERN AND POSSIBLY
SOUTHEAST CWFA THIS AFTERNOON. RADAR TRENDS SHOWS NEW CONVECTION
HAS DEVELOPED FROM DE KALB COUNTY BACK INTO NORTHERN BUREAU. RUC
TRENDS USING THE LIFT TOOL SUGGEST POSSIBLE DEVELOPMENT BACK TO
THE SOUTHWEST TO AREAS EAST OF THE MISSISSIPPI. FCST SOUNDINGS ARE
MARGINAL AT BEST TO SUPPORT CONVECTION AND ONLY FOR A NARROW
WINDOW BEFORE A CAP DEVELOPS BY LATE AFTERNOON.
THERE MAY STILL BE A THREAT FOR SMALL HAIL AND GUSTY WINDS THIS
AFTERNOON IN THE FAR EASTERN CWFA AND POSSIBLY THE SOUTHEAST CWFA.
HOWEVER...IF ADDITIONAL HEATING AND INSTABILITY DOES NOT DEVELOP
SOON THEN THAT THREAT WILL BE OVER BY LATE AFTERNOON.
AN UPDATE REFLECTING THE CURRENT TRENDS HAS BEEN SENT.
..08..
&&
.PREV DISCUSSION... /ISSUED 1229 PM CDT MON MAR 12 2012/
AVIATION...
MVFR TO VFR CONDITIONS WILL BE SEEN ACROSS THE AREA THROUGH 00Z/13.
STORM SYSTEM OVER THE MIDWEST WILL SLOWLY MOVE NORTHEAST THIS
AFTERNOON AND TONIGHT. A DISTURBANCE ROTATING AROUND THE STORM MAY
ALLOW SOME TSRA TO DVLP ALONG/EAST OF THE MISSISSIPPI RIVER.
KMLI/KBRL SHOULD HAVE THE BULK OF THE ACTIVITY EAST OF THEM BUT A
CB WORDING WAS INCLUDED WITH THE 18Z TAFS. CONVECTION SHOULD REMAIN
WELL EAST OF KCID/KDBQ. AFT 00Z/13 HIGH PRESSURE WILL BUILD INTO
THE MIDWEST AND ALLOW VFR CONDITIONS TO DEVELOP.
.08..
PREV DISCUSSION... /ISSUED 1047 AM CDT MON MAR 12 2012/
UPDATE...
THE OVERALL FCST HAS BEEN UPDATED TO BETTER REFLECT CURRENT
CONDITIONS. THE RUC SHOWS A NARROW AREA OF F VECTOR CONVERGENCE
FROM ABOUT KBRL TO KDKB WHICH WAS ALSO ALONG A THETA E GRADIENT IN
THE 850-300MB LAYER. THESE FEATURES EXPLAIN THE NARROW BAND OF
CONVECTION WITH A FEW TSRA ASSOCIATED WITH IT. THE REMAINDER OF
THE STRATIFORM RAIN CAN BE EXPLAINED WITH CONVERGENCE IN THE
800-750MB LAYER.
RUC TRENDS SHOW THE CURRENT PRECIP EXITING THE AREA LATE THIS
MORNING. WATER VAPOR INDICATES A VORT MAX ACROSS NORTHERN MISSOURI
THAT WILL ROTATE OVER THE SOUTHEAST HALF OF THE CWFA DURING THE
AFTERNOON HOURS. LIFT TOOL SHOWS STRONG CONVERGENCE DEVELOPING
WITH ANOTHER THETA E GRADIENT ROTATING INTO THE CWFA AS THE COLD
POCKET ALOFT MOVES EAST. THUS SHOWERS SHOULD BE MOST PREVALENT
OVER THE SOUTHEAST HALF OF THE CWFA WITH LOWER CHANCES OVER THE
NORTHWEST HALF OF THE CWFA. FCST SOUNDINGS FROM THE RUC SUGGEST
THAT TSRA WILL BE ALSO POSSIBLE OVER ROUGHLY THE SOUTHEAST HALF OF
THE CWFA AND BASED ON THE PROGGED WBZ HEIGHTS SMALL HAIL MAY BE
POSSIBLE WITH THE STRONGER CELLS.
.08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1229 PM CDT MON MAR 12 2012
.AVIATION...
MVFR TO VFR CONDITIONS WILL BE SEEN ACROSS THE AREA THROUGH 00Z/13.
STORM SYSTEM OVER THE MIDWEST WILL SLOWLY MOVE NORTHEAST THIS
AFTERNOON AND TONIGHT. A DISTURBANCE ROTATING AROUND THE STORM MAY
ALLOW SOME TSRA TO DVLP ALONG/EAST OF THE MISSISSIPPI RIVER.
KMLI/KBRL SHOULD HAVE THE BULK OF THE ACTIVITY EAST OF THEM BUT A
CB WORDING WAS INCLUDED WITH THE 18Z TAFS. CONVECTION SHOULD REMAIN
WELL EAST OF KCID/KDBQ. AFT 00Z/13 HIGH PRESSURE WILL BUILD INTO
THE MIDWEST AND ALLOW VFR CONDITIONS TO DEVELOP.
..08..
&&
.PREV DISCUSSION... /ISSUED 1047 AM CDT MON MAR 12 2012/
UPDATE...
THE OVERALL FCST HAS BEEN UPDATED TO BETTER REFLECT CURRENT
CONDITIONS. THE RUC SHOWS A NARROW AREA OF F VECTOR CONVERGENCE
FROM ABOUT KBRL TO KDKB WHICH WAS ALSO ALONG A THETA E GRADIENT IN
THE 850-300MB LAYER. THESE FEATURES EXPLAIN THE NARROW BAND OF
CONVECTION WITH A FEW TSRA ASSOCIATED WITH IT. THE REMAINDER OF
THE STRATIFORM RAIN CAN BE EXPLAINED WITH CONVERGENCE IN THE
800-750MB LAYER.
RUC TRENDS SHOW THE CURRENT PRECIP EXITING THE AREA LATE THIS
MORNING. WATER VAPOR INDICATES A VORT MAX ACROSS NORTHERN MISSOURI
THAT WILL ROTATE OVER THE SOUTHEAST HALF OF THE CWFA DURING THE
AFTERNOON HOURS. LIFT TOOL SHOWS STRONG CONVERGENCE DEVELOPING
WITH ANOTHER THETA E GRADIENT ROTATING INTO THE CWFA AS THE COLD
POCKET ALOFT MOVES EAST. THUS SHOWERS SHOULD BE MOST PREVALENT
OVER THE SOUTHEAST HALF OF THE CWFA WITH LOWER CHANCES OVER THE
NORTHWEST HALF OF THE CWFA. FCST SOUNDINGS FROM THE RUC SUGGEST
THAT TSRA WILL BE ALSO POSSIBLE OVER ROUGHLY THE SOUTHEAST HALF OF
THE CWFA AND BASED ON THE PROGGED WBZ HEIGHTS SMALL HAIL MAY BE
POSSIBLE WITH THE STRONGER CELLS.
..08..
PREV DISCUSSION... /ISSUED 320 AM CDT MON MAR 12 2012/
SYNOPSIS...
AS EXPECTED WIDESPREAD RAIN IN THE MOIST CONVEYOR BELT MOVED
THROUGH THE DVN CWA DURING THE NIGHT AND HAS FOR THE MOST PART
LIFTED TO THE NORTHEAST OF THE CWA EARLY THIS MORNING. DOPPLER
RADAR ESTIMATES RAINFALL IN THE 1/4 TO 1/2 INCH RANGE WEST OF THE
MS RIVER WITH LESSER AMOUNTS TO THE EAST. OTHERWISE THE UPPER LOW
WAS SPINNING ACROSS WESTERN IA WITH AN AREA OF SHOWERS INTO
CENTRAL IA. THERE WAS ALSO A TRAILING VORT MAX OVER NORTHWEST MO
AND WAS LIFTING TO THE NORTHEAST...AND WAS ALSO PRODUCING SHOWERS.
INCREDIBLY MILD AND MOIST FOR THIS TIME OF NIGHT IN THE MIDDLE OF
MARCH. CURRENT SURFACE DEWPOINTS IN THE CWA WERE IN THE UPPER 40S
TO LOWER 50S WITH TEMPERATURES MAINLY IN THE LOWER TO MID 50S.
HAASE..
SHORT TERM...TODAY AND TONIGHT...
FORECAST FOCUS ON THUNDERSTORM POTENTIAL ESPECIALLY THIS
AFTERNOON...THEN CLEAR AND COOLER TONIGHT.
TODAY...WILL START OUT THE DAY WITH LOW CLOUDS AND SCATTERED
SHOWERS. HOWEVER BY AFTERNOON ENOUGH BREAKS IN THE CLOUDS TO HAVE
A MIX OF CLOUDS AND SUNSHINE TO BOOST TEMPERATURES INTO THE MID
60S NORTH TO LOWER 70S SOUTH. THE COMBINATION OF THE UPPER LOW AND
COLD POCKET LIFTING ACROSS NORTHERN IA AND INTO WISCONSIN TODAY...
AND A TRAILING VORT MAX COMING OUT OF NW MO SHOULD TRIGGER ADDITIONAL
SCATTERED SHOWERS AND EVEN A FEW THUNDERSTORMS. THE BEST COVERAGE
WILL BE IN OUR NORTHERN CWA AND WILL HAVE AT LEAST 50 POPS. WILL
NEED TO KEEP AN EYE ON THUNDERSTORM POTENTIAL THIS AFTERNOON AS
THE VORT MAX LIFTS ACROSS THE CWA IN CONCERT WITH DAYTIME HEATING.
STEEP LAPSE RATES...MODERATE TO STRONG SHEAR WILL BE IN PLACE BUT
CAPES ARE MARGINAL AND A SURFACE LOW IS LACKING TO FOCUS SURFACE
CONVERGENCE. NONETHELESS FREEZING LEVELS OF LESS THAN 8K FT ARE
IDEAL FOR SMALL HAIL AND ANY ROTATING STORM MAY BE ABLE TO PRODUCE
ISOLATED DAMAGING WIND. SPC HAS A SLIGHT RISK FOR SEVERE STORMS
EAST OF THE DVN CWA FROM NORTHEAST IL INTO LOWER MI FOR MAINLY
THIS AFTERNOON. THE VORT MAX SHOULD LIFT AWAY FROM THE DVN CWA BY
LATE AFTERNOON IF NOT SOONER ENDING THE THUNDERSTORM THREAT.
TONIGHT...HIGH PRESSURE RIDGE WITH CLEAR SKIES AND LIGHT WINDS
OVER THE REGION. WITH LOWERING DEWPOINTS MINIMUM TEMPERATURES
SHOULD BOTTOM OUT IN THE UPPER 30S TO MID 40S.
HAASE..
LONG TERM...TUESDAY THROUGH SUNDAY...
THE FORECAST OF A LONG PERIOD OF VERY WARM...POSSIBLY RECORD LEVEL
WARMTH CONTINUES TO BE EXPECTED THROUGHOUT THE ENTIRE EXTENDED
FORECAST...AND BEYOND. A VERY SUMMER-LIKE AIRMASS SHOULD SET UP
TUESDAY...WITH A WEAK FRONTAL CONVERGENCE INTO THE CWA FROM
WEDNESDAY AFTERNOON THROUGH SATURDAY OR SUNDAY. THIS WEAK
CONVERGENCE WILL COMBINE WITH THE EXTREMELY MILD AND MOIST AIRMASS
TO PROVIDE A DAILY THREAT FOR SHOWERS AND STORMS...ALBEIT VERY LOW
DAILY CONFIDENCE IN THEM. I.E. SUMMER-LIKE.
DESPITE SURFACE HIGH PRESSURE AND LIGHT WINDS TUESDAY...THE SUN AND
VERY MILD AIR ALOFT SHOULD AID GETTING MIXING HEIGHTS HIGH ENOUGH TO
TAP INTO THE MILD AIR. THUS...WIDESPREAD UPPER 60S TO MID 70S ARE
FORECAST. WEDNESDAY WILL SEE BETTER MIXING YET...AND MID 70S TO NEAR
80 IS RIGHT ON TRACK FOR NOW...ESPECIALLY SINCE CLOUDS DO NOT LOOK
OPAQUE UNTIL LATE AFTERNOON...WHEN A FEW STORMS COULD FORM ALONG THE
WEAK FRONT.
THIS WEAK FORCING CONTINUES THROUGH THE END OF THE WEEK...WITH VERY
SIMILAR DAYTIME TEMPERATURES UNLESS ORGANIZED STORMS CAN FORM. WITH
SUCH LOW CONFIDENCE IN CONVECTION...OUR TEMPERATURE ARE FORECAST
BELOW THE SUNNY POTENTIAL...BUT WELL ABOVE THE LEVELS IF STORMS
OCCUR IN ANY PERIOD.
LOOKING SLIGHTLY BEYOND...THE UPPER PATTERN BECOMES MORE VOLATILE
WITH VERY FAST WINDS ALOFT AND STRONG FORCING WITH TIME...AND OUR
AIRMASS WILL LIKELY BECOME MORE MOIST AND WARM. THIS COMBINATION
COULD BRING OUR FIRST SEVERE WEATHER TO THE DVN CWA BY EARLY NEXT
WEEK.
ERVIN..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
228 PM CDT MON MAR 12 2012
...UPDATED LONG TERM DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 224 PM CDT MON MAR 12 2012
THE NAM, GFS AND ECMWF REMAINS CONSISTENT WITH PREVIOUS RUNS IN
PLACING A DRYLINE ACROSS PORTIONS OF SOUTHWEST KANSAS WEDNESDAY
AFTERNOON WITH OVER 1000J/KG OF CAPE FORECAST BY 00Z THURSDAY. THIS
INSTABILITY AND SURFACE BOUNDARY WILL BE LOCATED NEAR THE LEFT EXIT
REGION OF AN UPPER LEVEL JET SO GIVEN THIS WILL CONTINUE TO MENTION
A CHANCE OF LATE DAY/EVENING STORMS ACROSS SOUTH CENTRAL AND
PORTIONS OF SOUTHWEST KANSAS CLOSE TO THE OKLAHOMA BORDER. ALTHOUGH
THE EXACT LOCATION OF THE DRYLINE AND COLD FRONT IS STILL SOMEWHAT
UNCLEAR IT DOES APPEAR THAT THE MORE FAVORABLE LOCATION WILL BE NEAR
OR EAST OF A LIBERAL TO DODGE CITY TO NEAR GREAT BEND LINE. IT ALSO
APPEARS THE MAIN HAZARD FROM ANY STORM THAT MAY DEVELOP STILL BE
HAIL GIVEN THE MID LEVEL INSTABILITY, 0-6KM SHEAR AT OR BELOW
30KTS AND A WET BULB ZERO HEIGHT BETWEEN 1100-1300FT.
FOR THURSDAY AND FRIDAY THIS SURFACE BOUNDARY WILL MOVE VERY LITTLE
AND LATE DAY INSTABILITY BASED ON MIXED LAYER CAPES EACH EVENING
WILL RANGE FROM 1000 AND 1500J/KG. AS A RESULT UNABLE TO COMPLETELY
RULE OUT A LATE DAY STORM EITHER EVENING BUT BASED ON THE LATEST
TIMING OF A SUBTLE WAVE ROTATING ACROSS THE CENTRAL PLAINS LATE
FRIDAY WILL FOCUS THE BETTER OPPORTUNITY FOR CONVECTION FRIDAY
NIGHT.
AS FOR TEMPERATURES...THE PREVIOUS FORECAST STILL LOOKS ON TRACK
WITH ABOVE NORMAL TEMPERATURES PERSISTING INTO THE WEEKEND PERIOD
BASED ON THE 925-850MB TEMPERATURE TRENDS. ALSO WILL BE KEEPING LOWS
ABOVE GUIDANCE LATE WEEK AND OVER THE WEEKEND PERIOD BASED ON THE
EXPECTED RETURN OF LOW LEVEL MOISTURE ACROSS SOUTH CENTRAL AND MUCH
OF SOUTHWEST KANSAS.
LATE THIS WEEKEND THE NEXT SIGNIFICANT UPPER LEVEL SYSTEM WILL START
TO MOVE OUT OF THE EASTERN PACIFIC AND ONTO THE WEST COAST. THIS
UPPER LEVEL TROUGH IS EXPECTED TO DEEPEN EARLY NEXT WEEK AS IT
CROSSES THE SOUTHWEST UNITED STATES. MODELS TODAY CONTINUE TO
STRUGGLE WITH THE TRACK AND STRENGTH OF THIS NEXT SYSTEM EARLY WEEK
BUT IT DOES APPEAR A CHANCE FOR PRECIPITATION WILL RETURN BY LATE
MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1123 AM CDT MON MAR 12 2012
A DEEP DRY 12 UTC KDDC SOUNDING WAS OBSERVED WITH MODERATE WINDS
IN THE BOUNDARY LAYER. MOMENTUM TRANSFER WILL NOT BE IMPRESSIVE
THIS AFTERNOON AND WINDS ARE ANTICIPATED TO REMAIN AROUND 12 KNOTS
THROUGH THE AFTERNOON WITH MINIMAL GUSTS. SLIGHTLY STRONGER
SOUTHERLY WINDS ARE EXPECTED BY TUESDAY MORNING MAINLY DU8E TO A
BETTER SURFACE PRESSURE GRADIENT AND A BETTER 850 MB JET NOTED BY
MOS AND THE MESOSCALE MODEL. THE DRY LOWER AND MIDDLE LEVELS WILL
REMAIN IN PLACE THROUGH THE PERIOD ENSURING VFR CONDITIONS.
&&
.FIRE WEATHER...
ISSUED AT 1123 AM CDT MON MAR 12 2012
CONCERNS ARE INCREASING FOR CRITICAL FIRE WEATHER CRITERIA FARTHER
EAST THAN THE CURRENT WATCH HAD INDICATED. THIS MORNING`S VERY
DRY AND WARM BOUNDARY LAYER WITH +16 DEGREES AT 850 MB IN
ADDITION OT THE DRY AIR SHOULD CREATE A GREAT PRE EVENT
ENVIRONMENT FOR RAPIDLY FALLING RELATIVE HUMIDITIES WITH STRONG
MIXING ON TUESDAY. THE WINDS WOULD BE ASSUMED TO BE NEGLIGIBLE
ACCORDING TO THE GLOBAL MODELS, BUT MESOSCALE MODELS ARE
INDICATING 2 METER WINDS ABOVE 15 KNOTS WHICH SHOULD TRANSLATE INTO
FREQUENT GUSTS ABOVE 20 MPH EASILY. ADDITIONALLY THE MOS IS
ADVERTISING 20 KNOT WINDS AREA WIDE. WE WILL UPGRADE ALL WATCH
COUNTIES TO RED FLAG, AND ADD HODGEMAN, NESS AND TREGO COUNTIES
TO THE RED FLAG AS WELL. A BIT OF UNCERTAINTY EXISTS FARTHER EAST
AS MOISTURE ADVECTION COMES INTO PLAY WHICH MIGHT TEND TO NEGATE
THE LOWERING RH FARTHER SOUTHEAST. TO ACCOUNT FOR THIS, A WATCH
WILL BE ISSUED FOR MUCH OF THE REMAINDER OF OUR FORECAST AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 41 83 46 81 / 0 0 0 10
GCK 39 82 42 80 / 0 0 0 0
EHA 38 82 41 81 / 0 0 0 0
LBL 39 81 42 83 / 0 0 0 0
HYS 42 82 46 79 / 0 0 0 0
P28 44 81 53 81 / 0 0 0 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ TO 8 PM CDT /7 PM MDT/
TUESDAY FOR KSZ030-043>045-061>064-074>077-084>087.
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ031-046-065-066-078>080-088-089.
&&
$$
UPDATE...RUSSELL
SHORT TERM...GERARD
LONG TERM....BURGERT
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1145 AM CDT MON MAR 12 2012
...UPDATED FOR FIRE WEATHER AND AVIATION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM CDT MON MAR 12 2012
UPPER-LEVEL TROUGHING WILL PERSIST THROUGH MARCH 18TH ACROSS THE FAR
WESTERN UNITED STATES, THEN SLOWLY PROGRESS EASTWARD AND AMPLIFY
JUST TO OUR WEST BY MARCH 19-20TH. GIVEN THE EXPECTED POSITIONING OF
THIS TROUGH OVER THE FAR WESTERN UNITED STATES BY MID-WEEK,
SOUTHWESTERLY MID-LEVEL FLOW WILL BE PRESENT ACROSS THE ROCKIES AND
OVER THE PLAINS. LEE TROUGHING WILL DEVELOP IN RESPONSE TO THE FLOW
ACROSS THE ROCKIES, AND THIS WILL SERVE TO DRAW RICH LOW-LEVEL
MOISTURE NORTHWARD INTO THE SOUTHERN PLAINS. THE SURFACE DRYLINE
WILL MARK THE INTERFACE BETWEEN THE MOIST AIRMASS OVER THE PLAINS
AND THE DRY AIRMASS OVER THE WESTERN HIGH PLAINS AND ROCKIES. IT
WILL BE WARM EVERY DAY THROUGH THE WEEKEND WITH HIGHS IN THE 70S AND
80S AND LOWS FROM THE UPPER 40S WEST TO 55 TO 62 IN SOUTH CENTRAL
KANSAS. OFTENTIMES IN RETURN FLOW SITUATIONS IN MARCH, PREVIOUS COLD
FRONTAL PASSAGES THROUGH THE GULF AND EVEN INTO THE CARIBBEAN RESULT
IN ONLY MODEST MOISTURE RETURNS INTO THE PLAINS. THIS WILL NOT BE
THE CASE THIS WEEK SINCE THE GULF SEA SURFACE IS NEARLY AT
EQUILIBRIUM WITH THE AIR IMMEDIATELY ABOVE. GULF BUOY DATA INDICATE
DEWPOINTS AROUND 70F IN THE CENTRAL GULF CURRENTLY, WHICH IS VERY
IMPRESSIVE FOR THIS TIME OF YEAR. KEEP IN MIND THAT JUST BECAUSE 70F
DEWPOINTS ARE PRESENT IN THE CENTRAL GULF DOESN`T MEAN THAT WE CAN
EXPECT DEWPOINTS THAT HIGH IN SOUTHWEST KANSAS LATER THIS WEEK.
WHEN MOIST, MARINE AIR MOVES NORTHWARD INTO THE PLAINS, DEEP
VERTICAL MIXING OCCURS, WHICH CAUSES THE MOIST LAYER TO BE DEEPER,
BUT NOT QUITE AS RICH. ALSO, DODGE CITY IS 2600FT ABOVE SEA LEVEL
AND THIS INCREASED ELEVATION WILL RESULT IN SOME REDUCTION IN
DEWPOINT AS WELL AS THE MOISTURE MOVES ONTO THE HIGHER TERRAIN. SO
IT IS MORE REASONABLE TO EXPECT DEWPOINT TEMPERATURES FROM THE MID
50S TO THE MID 60S (13-18C) AHEAD OF THE DRYLINE.
BY WEDNESDAY AFTERNOON, THE SURFACE DRYLINE WILL STRETCH FROM A
WEAK SURFACE LOW AND FRONT OVER SOUTHWEST KANSAS SOUTH-SOUTHWESTWARD
INTO THE TEXAS PANHANDLE. A SUBTROPICAL JET STREAK WILL BE SITUATED
ACROSS THE TEXAS PANHANDLE. SURFACE BASED CAPE VALUES WILL APPROACH
2000 J/KG BY LATE AFTERNOON FROM DODGE CITY SOUTH AND EAST. THERE
MAY BE ENOUGH CONVERGENCE ALONG THE DRYLINE AND NEAR THE FRONT-
DRYLINE INTERSECTION, ALONG WITH STRONG ELEVATED HEATING, TO YIELD
ISOLATED THUNDERSTORMS. ANY STORMS THAT DEVELOP COULD BE SEVERE WITH
LARGE HAIL.
ISOLATED THUNDERSTORMS CANNOT BE RULED ANY DAY THROUGH MARCH 20TH AS THE
SURFACE DRYLINE REMAINS OVER WESTERN KANSAS. THE ECMWF INDICATES
THAT THE BEST CHANCES MAY BE SATURDAY FROM DODGE CITY SOUTHEASTWARD,
AND THEN AGAIN BY MONDAY AND TUESDAY AS THE UPPER-LEVEL TROUGH AND
ASSOCIATED MID-LEVEL COOLING APPROACH WESTERN KANSAS. ANY STORMS
THAT DEVELOP IN THESE PERIODS COULD BE SEVERE, ALTHOUGH THE BEST
CHANCE OF HIGH-END SEVERE STORMS WITH TORNADOES SHOULD BE LATER
MONDAY OR TUESDAY AS THE MID TO HIGH-LEVEL WINDS BECOME MUCH
STRONGER IN ADVANCE OF THE UPPER-LEVEL TROUGH. OF COURSE, A LOT
COULD CHANGE BETWEEN NOW AND MARCH 19TH-20TH; AND IT IS IMPOSSIBLE
TO SAY AT THIS POINT EXACTLY WHERE IN THE PLAINS THE BEST CHANCE
OF THUNDERSTORMS WILL BE.
KEEP IN MIND THAT DUE TO THE VERY WARM EXPECTED TEMPERATURES, RECORD
HIGH NIGHTTIME AND DAYTIME TEMPERATURES ARE POSSIBLE ACROSS WESTERN
KANSAS LATER THIS WEEK AND THIS WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1123 AM CDT MON MAR 12 2012
A DEEP DRY 12 UTC KDDC SOUNDING WAS OBSERVED WITH MODERATE WINDS
IN THE BOUNDARY LAYER. MOMENTUM TRANSFER WILL NOT BE IMPRESSIVE
THIS AFTERNOON AND WINDS ARE ANTICIPATED TO REMAIN AROUND 12 KNOTS
THROUGH THE AFTERNOON WITH MINIMAL GUSTS. SLIGHTLY STRONGER
SOUTHERLY WINDS ARE EXPECTED BY TUESDAY MORNING MAINLY DU8E TO A
BETTER SURFACE PRESSURE GRADIENT AND A BETTER 850 MB JET NOTED BY
MOS AND THE MESOSCALE MODEL. THE DRY LOWER AND MIDDLE LEVELS WILL
REMAIN IN PLACE THROUGH THE PERIOD ENSURING VFR CONDITIONS.
&&
.FIRE WEATHER...
ISSUED AT 1123 AM CDT MON MAR 12 2012
CONCERNS ARE INCREASING FOR CRITICAL FIRE WEATHER CRITERIA FARTHER
EAST THAN THE CURRENT WATCH HAD INDICATED. THIS MORNING`S VERY
DRY AND WARM BOUNDARY LAYER WITH +16 DEGREES AT 850 MB IN
ADDITION OT THE DRY AIR SHOULD CREATE A GREAT PRE EVENT
ENVIRONMENT FOR RAPIDLY FALLING RELATIVE HUMIDITIES WITH STRONG
MIXING ON TUESDAY. THE WINDS WOULD BE ASSUMED TO BE NEGLIGIBLE
ACCORDING TO THE GLOBAL MODELS, BUT MESOSCALE MODELS ARE
INDICATING 2 METER WINDS ABOVE 15 KNOTS WHICH SHOULD TRANSLATE INTO
FREQUENT GUSTS ABOVE 20 MPH EASILY. ADDITIONALLY THE MOS IS
ADVERTISING 20 KNOT WINDS AREA WIDE. WE WILL UPGRADE ALL WATCH
COUNTIES TO RED FLAG, AND ADD HODGEMAN, NESS AND TREGO COUNTIES
TO THE RED FLAG AS WELL. A BIT OF UNCERTAINTY EXISTS FARTHER EAST
AS MOISTURE ADVECTION COMES INTO PLAY WHICH MIGHT TEND TO NEGATE
THE LOWERING RH FARTHER SOUTHEAST. TO ACCOUNT FOR THIS, A WATCH
WILL BE ISSUED FOR MUCH OF THE REMAINDER OF OUR FORECAST AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 77 41 83 46 / 0 0 0 0
GCK 76 39 82 42 / 0 0 0 0
EHA 75 38 82 41 / 0 0 0 0
LBL 76 39 81 42 / 0 0 0 0
HYS 78 42 82 46 / 0 0 0 0
P28 78 44 81 53 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
&&
$$
UPDATE...RUSSELL
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...99
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
521 PM EDT MON MAR 12 2012
.SYNOPSIS...
AN UPPER-LEVEL DISTURBANCE WILL PASS THROUGH THE REGION TONIGHT
CAUSING SOME SHOWERS. HIGH PRESSURE WILL REMAIN OVER THE WESTERN
ATLANTIC DURING THE MIDDLE PORTION OF THE WEEK AND A SOUTHERLY FLOW
AROUND THE HIGH WILL USHER IN UNUSUALLY WARM CONDITIONS FOR THIS
TIME OF YEAR. A COLD FRONT WILL STALL OUT NEAR THE REGION LATE IN
THE WEEK INTO THE WEEKEND...BRINGING UNSETTLED CONDITIONS.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
2030Z UPDATE...RADAR INDICATES SHOWERS HAVE MOVED INTO THE POTOMAC
HIGHLANDS. HRRR INDICATES POTENTIAL FOR ANOTHER LINE OF SHOWERS TO
DEVELOP FURTHER EAST. INCREASED POPS TO CHANCE ACROSS THE NORTHERN
SHENANDOAH VALLEY...NORTHERN VA AND N CNTRL MD THIS EVENING.
PREVIOUS DISCUSSION...
AN UPPER-LEVEL RIDGE AXIS WILL SHIFT EAST TONIGHT WHILE UPPER-
LEVEL LOW PRESSURE TRACKS THROUGH THE GREAT LAKES AND INTO
SOUTHERN CANADA. A SOUTHERLY FLOW AROUND SURFACE HIGH PRESSURE
OVER THE ATLANTIC HAS BROUGHT ABNORMALLY WARM CONDITIONS TO THE
REGION THIS AFTERNOON. THE SOUTHERLY FLOW WILL CAUSE DEEP MOISTURE
TO MOVE INTO THE REGION TONIGHT. A WEAK AREA OF CONVERGENCE
ASSOCIATED WITH THE DEPARTING RIDGE AXIS WILL COMBINE WITH THE
MOISTURE TO TRIGGER SHOWERS ACROSS PORTIONS OF THE AREA. DESPITE
THE RAPID INCREASE IN MOISTURE...RAINFALL AMOUNTS WILL BE LIGHT
DUE TO THE WEAK FORCING. RAINFALL AMOUNTS WILL AVERAGE LESS THAN
ONE TENTH OF AN INCH ACROSS MOST LOCATIONS...BUT PERHAPS AROUND A
QUARTER INCH ACROSS THE ALLEGHENY AND POTOMAC HIGHLANDS.
MIN TEMPS WILL BE MUCH MILDER THAN RECENT NIGHTS DUE TO CLOUD COVER
AND A SOUTHERLY FLOW. MIN TEMPS WILL RANGE FROM THE MID AND UPPER
40S IN THE POTOMAC HIGHLANDS TO THE MID 50S IN WASHINGTON/BALTIMORE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
UPPER-LEVEL LOW PRESSURE WILL CONTINUE TO TRACK THROUGH SOUTHERN
CANADA TUESDAY WHILE A SURFACE PRESSURE TROUGH DEVELOPS OVER THE
REGION. A SOUTHWEST FLOW AROUND HIGH PRESSURE OVER THE ATLANTIC WILL
USHER IN EVEN WARMER CONDITIONS TUESDAY. THE DRY SLOT ASSOCIATED
WITH THE UPPER-LEVEL LOW WILL MOVE INTO THE REGION CAUSING SOME
SUNSHINE. SUNSHINE ALONG WITH A SOUTHWEST FLOW WILL ALLOW FOR MAX
TEMPS TO SOAR INTO THE 70S ACROSS MOST LOCATIONS. A FEW LOCATIONS
ACROSS CENTRAL VIRGINIA MAY REACH 80 DEGREES.
UNUSUALLY WARM AIR ALONG WITH DEWPOINTS IN THE 50S WILL CAUSE
MODERATE INSTABILITY TO DEVELOP. THE NAM/GFS BUFKIT INDICATE ABOUT
500-1000J/KG OF MLCAPE DEVELOPING TUESDAY AFTERNOON. INSTABILITY
WILL COMBINE WITH FORCING FROM THE SURFACE TROUGH FOR POSSIBLE
T-STORMS TUESDAY AFTERNOON. HOWEVER...T-STORMS WILL BE FIGHTING WITH
MID-LEVEL DRY AIR AND SUBSIDENCE. ANY T-STORMS THAT DO DEVELOP WILL
BE ISOLATED TO PERHAPS SCATTERED. THE BEST CHANCE FOR T-STORMS WILL
BE NEAR AND EAST OF THE I-95 CORRIDOR LATER TUESDAY AFTERNOON. IF
T-STORMS DO DEVELOP THAN MID-LEVEL DRY AIR AND AN INVERTED V
SIGNATURE IN THE SOUNDINGS SUGGEST THAT GUSTY WINDS AND HAIL ARE
POSSIBLE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE ERN HALF OF THE CONUS AND PAC NW WILL BE PARTICULARLY ACTIVE
OVER THE COMING WEEK. ACTIVITY OVER THE ERN HALF WILL BE MORE OF A
SLOW BOIL. A LEFTOVER FRONTAL BOUNDARY WILL STALL FROM THE SRN MS
VLY TO THE OHIO VLY...ALLOWING DISORGANIZED BATCHES OF SHOWERS/TSTMS
TO DEVELOP DAILY ON THE WRN SIDE OF A SLOW-MOVING UPPER RIDGE. THE
RIDGE WILL TEMPORARILY BOUNCED TO SOUTH WHILE THE TUESDAY UPPER
TROF SLIDES BY TO THE NORTH. THE RIDGE WILL BUILD BACK UP THE
SOUTHEAST AND SLOWLY INCH TOWARD THE SRN ATLC COAST BY THE END OF
THE WEEK. AS IT APPROACHES...CHANCES FOR SCATTERED SHOWER/TSTM
ACTIVITY INCREASES ACROSS THE DEEP SOUTH AND INTO THE MID ATLC
REGION.
IN BETWEEN ANY POTENTIAL RAINFALL FOR THE AREA IN THE COMING DAYS...
TEMPS WILL BE ALLOWED TO RISE WELL ABOVE NORMAL - NEAR RECORD
VALUES. WITH AVG HIGHS THIS TIME OF YEAR IN THE M50S /LOWS IN THE
M30S/...HIGHS MOST DAYS THIS WEEK WILL TOP OUT WELL INTO THE
70S/NEAR 80...AND 50S FOR OVERNIGHT LOWS. THE SLOW-MOVING HIGH
PRESSURE RIDGE ACROSS THE DEEP SOUTH WILL BE RESPONSIBLE FOR THESE
FEW STRAIGHT DAYS OF MUCH WARMER WX.
TOWARD THE END OF THE WEEK...THE WEAK/MODERATE ACTIVITY ACROSS THE
MS AND TENN VLY REGIONS WILL MAKE IT TO THE EAST COAST. POPS FOR FRI
AND SAT HAVE BEEN INCREASED TO AT LEAST HIGH-CHANCE RANGE BUT MOSTLY
OF THE WIDELY SCATTERED VARIETY COMING OVER TOP THE UPPER RIDGE.
HEADING INTO THE WEEKEND AND EARLY NEXT WEEK...ANOTHER PATTERN
CHANGE. EARLY INDICATIONS ARE THAT A LARGE AND POTENT UPPER TROF
WILL DIG DOWN THE PACIFIC COAST. THIS UPPER WAVE WILL ENCOMPASS THE
ENTIRE WRN HALF OF THE CONUS AT LEAST THE FIRST HALF OF THE WEEK
BEFORE MOVING INTO THE CNTRL PLAINS. MEANWHILE...THE ERN HALF WILL
BE UNDER A LARGE DOME OF HIGH PRESSURE.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS EXPECTED THROUGH TONIGHT. GUSTS HAVE ENDED AT SOME
TERMINALS...BUT CONTINUE AT KDCA/KCHO. GUSTS AT THESE TERMINALS
SHOULD END OR AT LEAST BE SPORADIC BY 23Z.
SHOWERS ARE LIKELY TONIGHT AS A DISTURBANCES MOVES THROUGH.
CIGS/VSBYS MAY APPROACH MVFR LEVELS LATE TONIGHT IN SHOWERS. VFR
CONDITIONS ARE EXPECTED TUESDAY WITH SOUTHWEST WINDS GUSTING UP TO
20 KNOTS IN THE AFTERNOON. ISOLATED/SCATTERED T-STORMS ARE POSSIBLE
TUESDAY AFTERNOON. IF T-STORMS DO DEVELOP...GUSTY WINDS AND HAIL
CANNOT BE RULED OUT. THE BEST CHANCE FOR T-STORMS WILL BE ACROSS THE
EASTERN TERMINALS LATE TUESDAY AFTERNOON.
RAIN CHANCES LOW WED-THU AS A LARGE AREA OF GULF MOISTURE MOVES
TOWARD THE ATLC COAST. INGREDIENTS WILL COME TOGETHER BETTER THU
NIGHT INTO FRI FROM SCATTERED SHOWERS...A FEW ISOLATED TSTMS. SAME
STORY INTO SAT...W/ THIS ACTIVITY EXITING OFF THE COAST LATE SAT
INTO SUN. WINDS DURING THE MED-LONG RANGE FORECAST ARE SOME OF THE
LIGHTEST IN A WHILE...MOST DAYS WE WILL SEE SFC WINDS 10KT OR LESS.
&&
.MARINE...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH TONIGHT FOR THE
WATERS. SOUTHERLY WINDS LATE THIS AFTERNOON WILL GUST UP TO 20
KNOTS. AN UPPER-LEVEL DISTURBANCE WILL PASS THROUGH THE WATERS
TONIGHT LIKELY BRINGING SHOWERS. WIND GUSTS AROUND 20 KNOTS ARE
EXPECTED ESPECIALLY IN SHOWERS TONIGHT.
HIGH PRESSURE WILL REMAIN OVER THE ATLANTIC TUESDAY ALLOWING FOR A
SOUTHWEST FLOW. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE MIDDLE
PORTION OF THE BAY AND LOWER TIDAL POTOMAC TUESDAY MORNING...AND FOR
ALL THE WATERS TUESDAY AFTERNOON. GUSTS AROUND 20 KNOTS ARE
EXPECTED.
ISOLATED-SCATTERED T-STORMS ARE POSSIBLE TUESDAY AFTERNOON. ANY
T-STORMS THAT DO DEVELOP WILL BE CAPABLE OF PRODUCING GUSTY WINDS
AND HAIL.
A HIGH PRESSURE RIDGE WILL BUILD ACROSS THE SOUTHEAST DURING THE
MIDDLE AND LATTER PART OF THE WEEK...KEEPING THE AREA QUIET THRU
AT LEAST LATE THU. SCATTERED SHOWERS AND ISOLATED TSTMS MAY IMPACT
THE WATERS FRI/SAT...THOUGH WINDS WILL STAY FAIRLY LIGHT
THROUGHOUT THE NEXT SEVERAL DAYS /10KT OR LESS MOST DAYS/.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ530-531-535-
536-538-539.
SMALL CRAFT ADVISORY FROM NOON TO 6 PM EDT TUESDAY FOR ANZ530-
531-535-536-538-539.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ532>534-537-
540>543.
&&
$$
SYNOPSIS...
NEAR TERM...BJL/KS
SHORT TERM...BJL
LONG TERM...GMS
AVIATION...BJL/GMS/KS
MARINE...BJL/GMS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
320 PM EDT MON MAR 12 2012
.SYNOPSIS...
SOME SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE
TONIGHT INTO TOMORROW...WITH DRY WEATHER EXPECTED FOR WEDNESDAY.
TEMPERATURES ARE EXPECTED TO BE WELL ABOVE NORMAL FOR THE ENTIRE 7
DAY FORECAST.
&&
.NEAR TERM /THROUGH TUESDAY/...
WIDESPREAD RAINFALL HAS CLEARED OHIO COUNTIES AND CONTINUES TO MOVE
TO THE EAST. HOWEVER...A LINE OF SCATTERED SHOWERS HAS DEVELOPED
ACROSS WESTERN OHIO. IF ANY LIGHTNING IS TO OCCUR...IT WOULD LIKELY
BE WITH THE SECOND LINE OF SHOWERS. ALL RAIN SHOULD CLEAR THE AREA
BY LATE EVENING. A COLD FRONT IS THEN EXPECTED TO CROSS THE EASTERN
GREAT LAKES LATE TONIGHT...AND CLIP THE FORECAST AREA TOMORROW.
FRONT WILL NOT HAVE MUCH MOISTURE TO WORK WITH...AND WILL ONLY GO
CHANCE POPS. ONCE AGAIN...INSTABILITY VALUES WARRANT AT LEAST A
SLIGHT CHANCE OF THUNDER. TEMPERATURES WILL REMAIN NEARLY STEADY
FROM AFTERNOON READINGS THROUGHOUT THE NIGHT...THEN RISE INTO THE
60S TOMORROW. THESE VALUES WILL BE MUCH HIGHER THAN SEASONAL NORMALS
OF MID 40S AND MID 20S.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE RIDGE WILL BUILD IN FROM THE SOUTH TUESDAY
NIGHT...WITH ALL PRECIPITATION HAVING MOVED EAST. THIS WILL KEEP
WEATHER QUIET THROUGH WEDNESDAY NIGHT. ASSOCIATED UPPER LEVEL RIDGE
WILL BEGIN TO MOVE OFFSHORE THURSDAY. 12Z GFS/00Z ECMWF SHOW
SHORTWAVE RIDING UP FROM THE PLAINS...AND WITH SOUTHWESTERLY FLOW
BRINGING IN GULF OF MEXICO MOISTURE...CHANCE OF THUNDERSTORMS WILL
RETURN TO THE FORECAST FOR THURSDAY. HIGHS WILL APPROACH 70 DEGREES
BOTH DAYS...WITH LOWS ALSO ABOVE NORMAL...IN THE 40S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BLEND OF HPC-PREFERRED ECMWF ENSEMBLE MEAN AND NAEFS MODEL OUTPUT
SHOW THE UPPER LEVEL JETSTREAM REMAINING SOUTHWEST IN ORIENTATION
THIS PERIOD. DEEP TROUGHING ALONG THE PACIFIC COAST MAY EVEN RESULT
IN STRONG ENOUGH RIDGING OVER THE EASTERN U.S. TO DEVELOP A BLOCKED
CUTOFF LOW OFF THE ATLANTIC COAST. HENCE EXPECT SPRINGLIKE
TEMPERATURES TO CONTINUE ACROSS THE UPPER OHIO VALLEY THIS PERIOD.
JUDGING FROM THE OPERATIONAL ECMWF, CMC AND GFS, AN EASTBOUND UPPER
LEVEL SHORT-WAVE TROUGH WILL DEVELOP AN OCCLUDED FRONTAL SYSTEM
ACROSS THE MISSISSIPPI VALLEY THURSDAY, THAT WILL BE PRECEDED BY LOW
LEVEL SOUTHERLY WINDS. THE RESULTING LIFT AND INFLUX OF GULF
MOISTURE WILL RESULT IN SHOWERS ACROSS THE UPPER OHIO VALLEY FRIDAY
AND FRIDAY NIGHT.
HAVE CONTINUED A CHANCE OF SHOWERS FOR THE WEEKEND, AS THE SYSTEM
MAY BE SLOW TO EXIT AND REMAINING MOISTURE MAY GENERATE AFTERNOON
INSTABILITY SHOWERS.
FORECASTED TEMPERATURE DETAILS USING HPC-PREFERRED ECMWF MODEL
OUTPUT, TEMPERED WITH SLIGHTLY COOLER GFS MOS AND NAEFS MEDIAN
VALUES. THIS YIELDED LOWS AND HIGHS OF GENERALLY 20 DEGREES WARMER
THAN NORMAL. ALTHOUGH HIGHS CAN BE IN THE 70S, MOST MID-MARCH
RECORD HIGHS ARE CLOSER TO 80.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
EXPECT MVFR CONDITIONS TO LINGER INTO TUESDAY MORNING.
BLEND OF RECENT SURFACE AND RADAR DATA, ALONG WITH HRRR AND NAM
MODEL OUTPUT, SHOW THE WARM FRONTAL BAND OF MVFR SHOWERS WILL EXIT
EAST BY 00Z. THERE CAN BE BRIEF IFR EPISODES.
NOCTURNAL COOLING OF THE RAIN-MOISTENED SURFACE LAYER SHOULD
MAINTAIN MVFR CONDITIONS TONIGHT. A SECOND BAND OF SCATTERED SHOWERS
MAY DELAY IMPROVEMENT TO VFR LEVELS UNTIL TUESDAY AFTERNOON.
WINDS WILL GENERALLY REMAIN SOUTHERLY AT 10KTS WITH GUSTS TO
15-20KTS INTO EARLY EVENING. WINDS WILL THEN BECOME SOUTHWEST AT 5-8
KTS TONIGHT.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
VFR INTO THURSDAY. RESTRICTIONS WITH SHOWERS WILL BE POSSIBLE
THURSDAY NIGHT INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
414 PM EDT MON MAR 12 2012
.SYNOPSIS...
ISSUED AT 413 PM EDT MON MAR 12 2012
UNSEASONABLY WARM WEATHER WILL DOMINATE THIS WEEK AS ABOVE NORMAL
500MB HEIGHTS RISE SLOWLY OVERALL. INTO THE UPCOMING WEEKEND...500MB
HEIGHT ANOMALIES OVER THE UPPER LAKES WILL INCREASE FROM 2 TO 2.5
STANDARD DEVIATIONS ABOVE THE LONG TERM AVG FOR MID MARCH. 850MB
TEMPS WILL ALSO BE RUNNING 2-2.5 STANDARD DEVIATIONS ABOVE THE LONG
TERM AVG. OVERALL...IT WILL PROBABLY FEEL MORE LIKE MID MAY THAN MID
MARCH. AT LEAST HERE AT THE OFFICE...SEVERAL HIGH TEMP RECORDS WILL
PROBABLY BE CHALLENGED OVER THE NEXT 7 DAYS. RAIN CHANCES LOOK
LIMITED WITH TROF SETTING UP WELL TO THE W OVER THE WRN CONUS AND A
STRONG RIDGE BUILDING OVER THE ERN CONUS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 413 PM EDT MON MAR 12 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED MID LEVEL
LOW SPINNING NE THRU WI. MAIN ARC OF STEADIER PCPN ASSOCIATED WITH
SYSTEM HAS LIFTED N AND E THRU UPPER MI TODAY. SCT PCPN IS OCCURRING
CLOSER TO THE CENTER OF THE MID LEVEL LOW WITH COVERAGE GENERALLY
INCREASING. UNDER APPROACHING COLD POCKET ALOFT ASSOCIATED WITH THE
LOW...A FEW LIGHTNING STRIKES HAVE FINALLY BEEN NOTED OVER CNTRL WI.
AFTER MORNING RAINFALL SATURATED THE LOW-LEVELS AND WITH PCPN LESS
WIDESPREAD THIS AFTN...FOG IS FAIRLY WIDESPREAD WITH SOME AREAS OF
DENSE FOG ALONG LAKE MICHIGAN AND WHERE WINDS ARE UPSLOPING.
WITH MID LEVEL LOW MOVING ACROSS THE AREA THIS EVENING...EXPECT
SCT/NMRS SHRA THIS EVENING. MAINTAINED SLIGHT CHC THUNDER OVER THE
SCNTRL THRU LATE AFTN SINCE SHRA ACTIVITY AROUND LOW APPEARS TO BE
INCREASING IN INTENSITY AND A FEW LIGHTNING STRIKES HAVE RECENTLY
OCCURRED IN CNTRL WI. SHORTWAVE CURRENTLY OVER THE DAKOTAS MAY WORK
TO MAINTAIN BETTER COVERAGE OF SHRA INTO THE LATE EVENING HRS OVER
THE NW PORTION OF THE FCST AREA AS IT TRACKS TO LAKE SUPERIOR.
OTHERWISE...PCPN LOOKS TO END RATHER QUICKLY OVERNIGHT FROM W TO E
AS STRONG DRYING SURGES INTO THE AREA UNDERNEATH UPPER JET.
-SHRA MAY LINGER INTO THE MORNING HRS OVER THE FAR NE FCST AREA.
OTHERWISE...THE STRONG DRYING WILL SET THE STAGE FOR A SUNNY DAY
TUE. DEEP DRY AIRMASS WILL SUPPORT DEEP MIXING...PERHAPS TO
800-750MB. PER FCST SOUNDINGS...THAT WILL YIELD MAX TEMPS AROUND 60F
OVER THE SCNTRL WHERE DOWNSLOPING WRLY WINDS WILL AID WARMING. 50S
SHOULD BE THE RULE ELSEWHERE...WITH LWR 40S ON THE W SIDE OF THE
KEWEENAW AND ALONG LAKE SUPERIOR E OF MUNISING DUE TO WINDS OFF THE
COLD WATERS. GIVEN THE VERY DRY AIRMASS ALOFT THAT CAN BE TAPPED...
LEANED TOWARD DWPTS THAT CAN BE ACHIEVED BY MIXING TUE AFTN.
ALTHOUGH POTENTIAL IS THERE FOR DWPTS TO CRASH TOWARD 0F OVER THE
FAR W AND CNTRL FCST AREA...OPTED TO JUST TREND FCST IN THAT
DIRECTION BY LOWERING GOING FCST SEVERAL DEGREES TO AROUND 10F AS A
START. THIS WILL PUT AFTN RH VALUES DOWN AROUND 15PCT.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 413 PM EDT MON MAR 12 2012
THE PERIOD STARTS 00Z WEDNESDAY WITH A LOW PRESSURE SYSTEM ENE OF
THE CWA AND A 500MB RIDGE OF HIGH PRESSURE CENTERED JUST W OF THE
CWA. AT THE SAME TIME...AN UPPER SHORTWAVE TROUGH WILL BE OVER THE
NWRN CONUS/WRN CANADA...WITH A SFC LOW OVER SASK AND SFC TROUGHING
LEEWARD OF THE ROCKIES STRETCHING INTO CO.
THE UPPER RIDGE WILL BE OVER THE CENTER OF THE CWA BY 12Z WED. THE
NW CONUS SHORTWAVE WILL BE NEAR THE NRN SASK/MANITOBA
BORDER...PUSHING THE SFC TROUGH FARTHER E INTO FAR WRN MN. THE
EASTWARD MOVING TROUGH COMBINED WITH A SFC RIDGE JUST E OF THE CWA
WILL RESULT IN INCREASING SW WAA TUE NIGHT INTO WED. 850MB TEMPS
WILL INCREASE FROM 0-5C BY 00Z WED TO 10-13C BY 18Z WED. THIS
RESULTS IN VERY WARM TEMPS FOR WED...WITH HIGHS IN THE MID TO UPPER
60S EXPECTED OVER PORTIONS OF CENTRAL AND WRN UPPER MI...ESPECIALLY
IN DOWNSLOPING AREAS. OVER ERN UPPER MI...HIGHS WILL BE LOWER IN THE
LOW TO MID 50S WITH THE SSW FLOW OFF LAKE MI. THROUGH 00Z THU THINGS
SHOULD STAY DRY AS THE SFC TROUGH MOVES INTO THE FAR WRN CWA. THE
NAM SHOWS SOME CONVECTION POPPING UP BETWEEN 18Z WED AND 00Z THU
OVER THE FAR ERN CWA...BUT THE NAM IS ALSO THE FASTEST WITH MOVING
THE COLD FRONT THROUGH. WITH THE CONSENSUS IDEA...THE COLD FRONT
WILL BE MOVING OUT OF THE SERN CWA BY 00Z FRI. CONSENSUS MODELS ALSO
SHOW CONVECTION OVER CENTRAL AND ERN UPPER MI...BUT MAINLY NEAR LAKE
MI AND OVER FAR ERN UPPER MI AFTER 00Z THU. THE HEAVIER CONVECTION
SHOULD STAY S/SE OF THE CWA AS MODELS SHOW TOO MUCH CAPPING THIS FAR
N...SO SLIGHT CHANCE OF THUNDER WAS RETAINED FROM PREVIOUS FORECAST.
THURSDAY...WITH THE COLD FRONT STALLING JUST SE OF THE CWA...RAIN
WILL REMAIN POSSIBLE NEAR LAKE MI AND E...BUT ONLY CHANCE TO SLIGHT
CHANCE POPS SEEM WARRANTED AT THIS TIME. THURSDAY LOOKS TO BE COOLER
BEHIND THE COLD FRONT WITH 850MB TEMPS AROUND 7C...SO HIGHS WILL BE
IN THE 40S NEAR LAKE SUPERIOR AND NEAR 60 NEAR THE WI BORDER.
FOR THE EXTENDED...MODELS SHOW ANOTHER UPPER DISTURBANCE MOVING N OF
THE CWA THU NIGHT...WITH AN UPPER RIDGE MOVING OVER THE CWA ON FRI.
AFTER FRI...CONFIDENCE IS DECREASED SOME AS MODELS SHOW DIFFERING
SOLUTIONS WITH THE PASSAGE OF A SERIES OF SHORTWAVES THROUGH MONDAY.
HOWEVER...WARM CONDITIONS ARE A CERTAINTY INTO EARLY NEXT WEEK GIVEN
STEADY S/SW FLOW WITH SFC HIGH PRESSURE E AND LOW PRESSURE W. USED
CONSENSUS OF MODELS THROUGH THE EXTENDED WITH SLIGHT CHANCE TO LOW
CHANCE POPS AS MODELS SHOW SOME PRECIP/CONVECTION IN THE WAA REGIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 147 PM EDT MON MAR 12 2012
COMPLEX AVIATION FORECAST THIS AFTN AS MID LEVEL LOW CURRENTLY OVER
SE MN/SW WI MOVES NORTHEAST. DENSE FOG/VLIFR CONDITIONS HAVE SETTLED
INTO KCMX/KSAW UNDER LOCALLY UPSLOPING WINDS. WITH DOWNSLOPING WINDS
AT KIWD...CONDITIONS HAVE BEEN MVFR AND THAT SHOULD CONTINUE THIS
AFTN. AS NEXT ROUND OF SCT SHRA ARRIVES ALONG WITH SFC TROF...EXPECT
CONDITIONS TO IMPROVE TO MVFR AT KCMX/KSAW BY LATE AFTN. WIND SHIFT
TO SW WILL ALSO HELP IMPROVE CONDITIONS. AS THE LOW MOVES NE
OVERNIGHT...EXPECT A FAIRLY QUICK TRANSITION TO CLEAR SKIES UNDER
STRONG DRYING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 413 PM EDT MON MAR 12 2012
UPPER LEVEL DISTURBANCE AND SURFACE TROF WILL MOVE ENE ACROSS LAKE
SUPERIOR TONIGHT. AHEAD OF THE TROF...SHOWERS AND INCREASINGLY MOIST
AIRMASS WILL SUPPORT SOME FOG...ESPECIALLY OVER WRN AND NRN PORTIONS
OF THE LAKE. FOG SHOULD THIN OUT AFTER TROF PASSES AND WINDS SHIFT
AROUND TO THE W AND INCREASE. WARM AIR ABOVE THE SURFACE WILL LIKELY
KEEP THE MARINE LAYER IN PLACE AND LIMIT THE STRONGER WINDS ALOFT
FROM REACHING THE SURFACE LATE TONIGHT AND TUE. AT THIS TIME...ONLY
EXPECT GUSTS REACHING 30KTS. AFTER TUE...WINDS WILL PROBABLY REMAIN
MOSTLY UNDER 20KTS WITH A RELATIVELY WEAK PRESSURE GRADIENT IN
PLACE. UNSEASONABLY WARM AIRMASS OVER THE UPPER GREAT LAKES WILL
ALSO RESULT IN PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE
LAKE...HELPING TO KEEP WINDS LIGHTER.
&&
.HYDROLOGY...
ISSUED AT 413 PM EDT MON MAR 12 2012
NEAR RECORD TO RECORD SETTING TEMPS YESTERDAY HAS HELPED RIPEN THE
SNOW PACK. RAIN MOVING THROUGH TODAY WILL EXIT THE AREA TONIGHT. THE
BULK OF THE RAIN FELL DURING THE MORNING TO EARLY AFTERNOON HOURS
TODAY...WITH ACCUMULATIONS OF AROUND 0.25 TO 0.70IN. THE
RAIN...COMBINED WITH DEWPOINTS IN THE 40S...WILL HELP TO QUICKEN
SNOWMELT THIS EVENING. AS OF THIS AFTERNOON...LARGER RIVERS ARE
STARTING TO SHOW SOME INCREASED RESPONSE TO THE MELTING AND
PRECIPITATION.
THE RAIN AND SNOW MELT TODAY...COMBINED WITH ABOVE NORMAL
TEMPERATURES THROUGH NEXT WEEKEND WILL LEAD TO A INCREASE IN
RIVER AND STREAM LEVELS OVER THE NEXT SEVERAL DAYS. EXPECT SOME OF
THE RIVERS ACROSS THE AREA TO EXCEED THEIR BANKS BY THE END OF THIS
WEEK. PERSONS LIVING NEAR RIVERS AND STREAMS SHOULD
MONITOR THE LATEST RIVER CONDITIONS AND USE CAUTION IF WALKING
ALONG RIVER BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
ICE JAM WISE...NOT MUCH ICE HAS BEEN NOTED BY OBSERVERS ON THE
FASTER FLOWING RIVERS OVER NRN UPPER MI. BUT THE FORD RIVER...BOTH
AT HYDE AND THE MOUTH AT LK MI...STILL HAS GOOD ICE COVER THAT
LEADS TO SOME CONCERN FOR ICE JAM POTENTIAL WITH THE FASTER RUNOFF.
ALTHOUGH LIMITED SNOW WAS NOTED NEAR LK MI...THERE IS STILL 3-8IN
OF SNOW ...AND NOHRSC ESTIMATED AROUND 1.25IN OF LIQUID...TOWARDS
THE HEADWATERS THAT WILL BE MELTED OVER THE COMING DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ221-248-
250.
&&
$$
SYNOPSIS...ROLFSON
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
351 PM EDT MON MAR 12 2012
.SHORT TERM...THIS EVENING AND TONIGHT
STRONG UPPER LOW NOW LOCATED OVER NORTHERN WISCONSIN WILL CONTINUE
TO TRACK TO THE NE ACROSS LAKE SUPERIOR TONIGHT. THE SURFACE
REFLECTION IS RATHER WEAK AS IT REMAINS AN OPEN TROUGH TIED TO A
CLOSED CIRCULATION FURTHER NW OVER MANITOBA. MID LEVEL DRY SLOT IS
WORKING ITS WAY ACROSS SOUTHERN MI PUSHING THE DEEPER MOISTURE FROM
THIS MORNING OFF TO THE EAST. BREAKS IN THE CLOUD COVER HAS ALLOWED
SOME DIURNAL HEATING OVER FAR SW LOWER MI. TEMPS ARE PUSHING THE
UPPER 60S IN THOSE LOCATIONS. IN ADDITION...S/SW WINDS GUSTING UP TO
25 KNOTS HAS BROUGHT IN ABUNDANT SFC MOISTURE WITH DEWPOINTS IN THE
MID 50S ACROSS ALL OF SOUTHERN MI. THE EXCEPTION IS OVER THE EXTREME
EASTERN PORTIONS OF THE CWA WHERE A SE COMPONENT IS STILL HANGING
ON. THIS HELD THE SUB 1000FT CLOUDS FIRMLY UNTIL ABOUT THE LAST WHEN
THEY STARTED TO SCATTER OUT. THUNDERSTORM COMPLEX FROM EARLIER WEST
OF CHICAGO HAS TRACKED NORTH INTO WESTERN MI NORTH OF MUSKEGON. WITH
WIND SHEAR NEARLY UNIDIRECTIONAL FROM THE SW...COMPLEX IS STRUGGLING
TO MAKE ANY EASTWARD PROGRESS.
FOR TONIGHT...THREAT FOR SEVERE WEATHER LATE THIS EVENING REMAINS
CONDITIONAL ON AMOUNT OF SURFACE BASED INSTABILITY WE CAN ACHIEVE.
THERE LOOKS TO BE PLENTY OF WIDESPREAD LIFT SUPPORTING STORM
DEVELOPMENT WITH THE UPPER LEVEL COLD POOL IN PLACE AND THE ENTRANCE
REGION OF A JET STREAK OVER THE REGION. THERE ARE FAVORABLE WIND
PARAMETERS ASSOCIATED WITH THE FRONTAL PASSAGE. BULK SHEAR VALUES
AROUND 40-50 KNOTS...BOTH 0-3KM AND 0-1 KN HELICITY IN EXCESS OF 300
M2/S2. LOOKING AT CAPE VALUES...THOUGH NAM MUCAPE IS ADVERTISED AT
800J/KG...NEITHER THE NAM OR RUC FIND MUCH IN THE WAY OF SFC BASED
CAPE WITH VALUES UP TO 100-200 J/KG WITH HIGHEST AMOUNTS FOR THE
WESTERN PART OF THE CWA. HIRES MODELS SHOW SOME ISOLATED CELLS
TRYING TO GO UP IN ADVANCE OF THE COLD FRONT WITH THE BULK OF THE
SHOWERS/STORMS OCCURRING THE FRONT ITSELF MAINLY FROM
23Z-05Z...WORKING SOUTH FROM MBS TO DTW. LOOKS LIKE SMALL HAIL AND
WIND GUSTS TO 50MPH WILL BE THE MOST LIKELY RESULTS OF THESE
STORMS...ALTHOUGH IF WE CAN GET MORE SFC BASED INSTABILITY SEVERE
STORMS WILL NOT BE OUT OF THE QUESTION.
&&
.LONG TERM...
THE WARM PATTERN LOOKS TO STICKING AROUND FOR THE EXTENDED
PERIOD...WITH POTENTIAL PSEUDO OMEGA BLOCKING PATTERN SETTING UP
LATE IN THE WEEKEND/EARLY NEXT WEEK.
CONSOLIDATING UPPER WAVES TAKES PLACE OVER ONTARIO TOMORROW...WITH
SHORTWAVE TROUGH AXIS AND SLIGHT HEIGHT FALLS TAKING PLACE LATE IN
THE DAY. STILL...WITH FAVORABLE WESTERLY WINDS AND THE TEMP GRADIENT
ADVERTISED (925 MB TEMPS OF 8 C NORTH TO 11 C SOUTH)...LOOKING AT
UPPER 50S NORTH TO MID 60S SOUTH WITH PLENTY OF SUNSHINE.
SURFACE RIDGE AXIS ARRIVING TOMORROW EVENING SHOULD ALLOW FOR
FAVORABLE RADIATING CONDITIONS...BUT WE ALREADY HAVE MODEST LOW
LEVEL WARM ADVECTION RETURNING BY SUNRISE WEDNESDAY. GUIDANCE TEMPS
IN THE 30S APPEAR REASONABLE.
A DRY WARM FRONT EXPECTED TO PUSH NORTH OF SOUTHERN LOWER MICHIGAN
DURING WEDNESDAY AS UPPER LEVEL RIDGE BUILDS OVERHEAD...PUSHING
TEMPS TO 70 DEGREES OR BETTER BASED ON FORECASTED 925 MB TEMPS OF
+15 TO +16 C. THE EXCEPTION WILL BE ACROSS THUMB REGION WHERE FRONT
WILL PROBABLY NOT CLEAR BY DAYS END...WITH BACKED SOUTHEAST FLOW
COMING OFF COOL WATERS OF SOUTHERN LAKE HURON.
DEEP SOUTHWEST FLOW OVER THE CENTRAL CONUS THURSDAY/FRIDAY...WITH
POTENTIAL UPPER LEVEL PV FILAMENT ROLLING THROUGH ON THURSDAY...PER
12Z GFS...TO TRIGGER SHOWERS AND POSSIBLE THUNDERSTORMS...AS
RESPECTABLE SURGE IN MOISTURE TAKES PLACE. CLOUDS AND CONVECTIVE
ACTIVITY COULD BE ENOUGH TO KEEP TEMPS STUCK IN THE UPPER 60S
DESPITE THE VERY MILD START TO THE DAY. THE 12Z EUROPEAN OFFERS A
DIFFERENT SOLUTION AND SUGGESTS THE SHORTWAVE/TROUGH COMING OUT OF
THE NORTHERN PLAINS WILL BE STRONGER...MOVING THROUGH ON FRIDAY.
THIS WOULD TRANSLATE TO A WARM DAY ON THURSDAY (70S) AND BETTER
CHANCE OF SHOWERS ON FRIDAY. THE CANADIAN IS MORE IN LINE WITH THE
GFS...SO WILL NOT MAKE A BIG PUSH TO EXTENDED GRIDS MUCH.
MEDIUM RANGE MODELS STILL FORECASTING AMPLIFIED PATTERN FOR THE
WEEKEND INTO EARLY NEXT WEEK...WITH LONGWAVE TROUGH OUT WEST AND
UPPER LEVEL RIDGE BUILDING NEAR THE GREAT LAKES REGION. ALMOST
SUMMER LIKE RIDGE (582-586 DAM AT 500 MB)...AND TEMPS APPROACHING 80
DEGREES IS NOT OUT OF THE QUESTION AS WE GET TO TUESDAY AS 1000-500
MB THICKNESSES CLIMB TOWARD 564 DAM. LAKE BREEZES WOULD LIKELY BE
COMING INTO PLAY HOWEVER AND WILL NEED TO REMAIN MORE CONSERVATIVE
THAT FAR OUT...ESPECIALLY WITH THE EUROPEAN PROFILES A BIT COOLER.
&&
.MARINE...
OUTSIDE OF A FEW POSSIBLE THUNDERSTORMS THIS EVENING...MARINE
CONDITIONS ARE EXPECTED TO REMAIN QUIET. UNUSUALLY MILD AIR IN PLACE
FOR EARLY MARCH WILL LEAD TO STABLE STABLE LOW LEVEL PROFILES OVER
THE GREAT LAKES. THIS WILL MINIMIZE THE GUST POTENTIAL TO AROUND 20
KNOTS OVER THE NEXT SEVERAL DAYS. THOSE STRONGER WINDS LOOKED TO BE
CONFINED TO THE NORTH THIRD OF LAKE HURON TOMORROW...AS CHANNELING
OCCURS WITH WESTERLY FLOW. THE NEXT CHANCE OF THUNDERSTORMS RETURNS
ON THURSDAY.
&&
.AVIATION...ISSUED 133 PM EDT MON MAR 12 2012
//DISCUSSION...
FIRST WAVE OF RAIN HAS EXITED THE AREA AS THE DRY SLOT WORKS INTO
SOUTHERN MI. THIS WILL MAKE FOR MVFR CIGS THROUGH THE
AFTERNOON. ANY LINGERING IFR CIGS BELOW 1000FT WILL LIFT RAPIDLY
AFTER ISSUANCE. ATTENTION TURNS TO LATER THIS EVENING WHEN A COLD
FRONT WILL SWEEP THROUGH SE MI BRINGING ANOTHER ROUND OF SHOWERS.
GENERAL TIMING WILL BE BETWEEN 00Z (MBS) TO 05Z (DTW/DET). POTENTIAL
EXISTS FOR SOME THUNDERSTORMS TO DEVELOP BUT COVERAGE MAY BE TOO
LIMITED TO INCLUDE IN THE TAFS AT THIS TIME. TIMING OF THE FRONT
WOULD SUGGEST MBS/FNT HAVE THE BEST CHANCE FOR THUNDER BEING ABLE TO
TAP INTO DIURNAL INSTABILITY. DRY AIR WILL ADVECT INTO THE STATE ON
TUESDAY LEADING TO CLEAR SKIES BY LATE MORNING.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH TONIGHT.
* LOW CONFIDENCE IN THUNDERSTORM POTENTIAL THIS EVENING.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...DRK
LONG TERM....SF
MARINE.......SF
AVIATION.....DRK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
148 PM EDT MON MAR 12 2012
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 411 AM EDT MON MAR 12 2012
WV IMAGERY AND RUC ANALYSIS SHOWING UPPER LOW SPINNING OVER ERN
NEB. BROAD AREA OF LIGHT/MOD RAIN ON RADAR/OBS COVERING MUCH OF WI
AT THIS TIME AND PUSHING N. THIS WILL BE THE INITIAL FEATURE OF
CONCERN FOR THE FIRST PART OF THE MORNING.
THIS PCPN IS LOCATED ALONG AN AREA OF H925-700 WAA/FGEN...ALONG WITH
290-300K ISENTROPIC ASCENT. IN ADDITION...NOSE OF UPPER JET ROTATING
AROUND THE BASE OF THE UPPER LOW IS FOCUSED OVER WI AND WITH THE
AREA OF PCPN. HAVE DEFINITE POPS PUSHING N ACROSS THE CWA AS THIS
AREA OF RAIN PUSHES N...BUT THERE IS CONCERN ON WHETHER THIS WILL
HOLD TOGETHER. MODELS CONSISTENT ON THIS AREA OF FORCING DIMINISHING
AND SHEARING OUT AS IT PUSHES N INTO THE CWA EARLY THIS MORNING AND
ENCOUNTERS EXISTING DRY AIR. HIRES MODELS...INCLUDING
RUC/HRRR...HAVE BEEN HANDLING THE COVERAGE OF THE RAIN WELL THIS
MORNING AND ALSO SHOW THE PCPN DIMINISHING AS IT MOVES OVER THE NRN
HALF OF THE CWA. PCPN MAY ACTUALLY END FOR A PERIOD OF TIME OVER
PORTIONS OF THE SW CWA SHORTLY AFTER MORNING DRIVE TIME. EXPECT LOW
CLOUDS TO REMAIN IN PLACE BEHIND THIS INITIAL SURGE OF RAIN...AS DRY
AIR ABOVE H850 ROTATES THROUGH. SHOULD ALSO SEE SOME FOG DEVELOP
THROUGH THE MORNING...ESPECIALLY FOR AREAS FAVORED BY UPSLOPE SE
FLOW...INCLUDING NCNTRL UPPER MI AND THE KEWEENAW.
AFTER A BRIEF REPRIEVE BEHIND THIS INITIAL BAND OF RAIN...SECONDARY
SURGE LOOKS TO ARRIVE TOWARDS MID DAY AND CONTINUE INTO THE AFTN.
THIS IS ASSOCIATED WITH THE UPPER LOW AND SFC TROUGH PUSHING NE
INTO THE CWA. NOSE OF THE UPPER JET WILL BE FOCUSED OVER LOWER MI
AT THIS TIME...BUT FORCING FROM THE UPPER LOW AND ASSOCIATED HEIGHT
FALLS SHOULD BE SUFFICIENT TO REDEVELOP SCT/NUMEROUS SHOWERS THAT
MOVE FROM SW TO NE ACROSS THE CWA. COULD EVEN HAVE A FEW RUMBLES OF
THUNDER OVER PORTIONS OF THE SRN HALF OF THE CWA THIS AFTN WITH ANY
OF THE STRONGER SHOWERS. WITH THE UPPER LOW AND STRONG HEIGHT FALLS
MOVING THROUGH THIS AFTN...MID LVL LAPSE RATES INCREASE AND CREATES
POCKETS OF WEAK INSTABILITY. HAVE EXPANDED THE PREVIOUS ISOLATED
THUNDER MENTION SLIGHTLY BASED OFF LATEST TRENDS. AS WINDS TURN TO
THE SW IN THE AFTN...EXPECT FOG TO BECOME MORE PATCHY...AS MODELS
INDICATE A LITTLE DEEPER MIXING. DELAYED THE DIMINISHING FOG A
LITTLE FARTHER INTO THE AFTN. CONTINUED TO LINGER THE FOG INTO THE
EVENING OVER THE E WHERE THE RELATIVELY WARM/MOIST AIR WILL BE
FLOWING OFF LK MI.
AS THE UPPER LOW MOVES OVER LK SUPERIOR LATE THIS AFTN AND
EVENING...THIRD WAVE OF RAIN WILL AFFECT MAINLY THE WRN HALF OF THE
CWA. THIS IS ASSOCIATED WITH THE WRAP AROUND MOISTURE AND WEAK
290-305K ISENTROPIC ASCENT. THIS SHOULD CONTINUE THROUGH MUCH OF THE
EVENING HOURS OVER THE W HALF...AS THE BACK EDGE OF THE PCPN SLIDES
FROM MN AND THROUGH THE AREA. WITH THE MOISTURE AND PCPN CLOSELY
TIED WITH THE UPPER LOW...EXPECT A QUICK DIMINISHING TREND TO
POPS/SKY AFTER MIDNIGHT TONIGHT AS THE LOW MOVES INTO ONTARIO.
OVERALL...TRYING TO TIME THESE FEATURES IS EXTREMELY
DIFFICULT...ESPECIALLY WITH THE SEVERAL PERIODS OF RAIN. HAVE OPTED
TO GO WITH A SHOWERY WORDING INSTEAD OF STRATIFORM DUE TO THESE
PERIODS.
TUES...UPPER LOW THAT PASSED THROUGH THE AREA TODAY AND THIS EVENING
WILL PHASE WITH NRN STREAM TROUGH JUST TO THE N OF LK SUPERIOR ON
TUES. THIS WILL LEAD TO NW FLOW ALOFT ON TUES...BUT TROUGH IS
QUICKLY SHIFTING EAST. SOME DIFFERENCES IN HOW FAR S THE PHASING
OCCURS...WHICH COULD LEAD TO SOME LINGERING CLOUDS OVER THE KEWEENAW
AND FAR ERN UPPER MI. 18Z/00Z GFS WAS MUCH FARTHER S THAN OTHER
MODELS...WHICH ACTUALLY HOLDS PCPN INTO THE MORNING HOURS OVER FAR
ERN UPPER MI DUE TO THE DEEPER PHASING. WILL KEEP THE CLOUDS MAINLY
OVER NE LAKE SUPERIOR TO ACCOUNT FOR THIS UNCERTAINTY.
DECENT SPREAD IN GUIDANCE FOR HIGHS DUE TO THE DIFFERENCES IN
HANDLING THE PHASING OF THE UPPER THROUGH. MIXING TO H875-850
/AROUND 2C/ YIELDS HIGHS IN THE MID 50S...SO HAVE ADJUSTED EXISTING
HIGHS DOWN A TOUCH. WITH MAINLY NW FLOW...HAVE KEPT TEMPS NEAR LK
SUPERIOR A LITTLE COOLER. DEWPOINT VALUES WILL BE THE MAIN CONCERN
FOR TUES AFTN. DROPPED VALUES A GOOD 7-10 DEGREES OVER THE WRN
HALF OF THE CWA...WITH MODELS CONSISTENTLY SHOWING DECENT MIXING
INTO DRY AIR ALOFT. SOME OF OUR LOCAL MIXED TD TOOLS ACTUALLY GIVE
VALUES IN THE SINGLE DIGITS ABOVE ZERO...WHICH DOESN/T SEEM TOO
UNREASONABLE. STRAIGHT MODEL MIXED TD VALUES ARE IN THE LOWER
TEENS...SO HAVE TRENDED TOWARDS THAT WITH VALUES IN THE UPPER
TEENS. FORTUNATELY...THERE IS STILL A DECENT SNOW PACK...OTHERWISE
THERE COULD BE FIRE WX CONCERNS WITH GUSTY NW WINDS AND RH VALUES
FALLING INTO THE LOW 20S.
TUES NIGHT...WITH UPPER TROUGH CONTINUING E AND UPPER RIDGE
REBUILDING OVER THE NRN PLAINS...EXPECT DRY WX AND MOSTLY CLEAR
SKIES. SFC RIDGE MOVING ACROSS THE AREA WILL LEAD TO LIGHT WINDS
AND HAVE DROPPED TEMPS A FEW DEGREES. COULD SEE TEMPS FALL A LITTLE
MORE THAN EXPECTED OVER THE ERN CWA...DUE TO LIGHTER WINDS AND DRY
AIR ALOFT PRODUCING PWATS AROUND 70 PERCENT OF NORMAL. HAVE COOLED
THE TRADITIONAL COLD SPOTS SOME OVER THE ERN CWA TO BELOW FREEZING
VALUES. FINALLY...H850 WAA COULD LEAD TO A FEW CLOUDS DEVELOPING
OVER THE WRN LK AND WRN UPPER MI AFTER MIDNIGHT...BUT LIMITED
MOISTURE HAS CONFIDENCE LOW.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 411 AM EDT MON MAR 12 2012
WED...THE UPR RDG OVER THE GRT LKS WL MOVE SLOWLY TO THE E...BUT ITS
EWD PROGRESS WL BE SLOWED BY CUTOFF LO OVER NEW ENGLAND. AS A FAIRLY
STRONG DISTURBANCE MOVES INTO CNTRL CAN...ITS ATTENDANT TROF WL
APRCH THE UPR LKS BY LATE IN THE DAY. THE NAM IS THE FASTEST MOVING
THIS TROF ACRS THE CWA ON WED...BUT PREFER THE CONSENSUS OF THE
SLOWER MODELS GIVEN THE BLOCKING CUTOFF IN NEW ENGLAND. THESE MODELS
HINT THE TROF WL REACH THE W ONLY LATE IN THE DAY. WITH THE DRYNESS
OF THE ANTECEDENT AIRMASS AND A LACK OF ANY SGNFT UPR FORCING SO FAR
S OF THE DISTURBANCE MOVING THRU CNTRL CAN...OPTED TO RETAIN GOING
DRY FCST. WITH H85 TEMPS PEAKING ARND 10C...EXPECT ANOTHER DAY OF
WELL ABV NORMAL TEMPS...EVEN IF THE MORE PESSIMISTIC GFS IS CORRECT
ON SHOWING ENUF LLVL MSTR ARRIVING TO SUPPORT SC DEVELOPMENT IN THE
SW FLOW AHEAD OF THE INCOMING TROF. MIXING TO JUST H875 ON GFS FCST
SDNGS WOULD YIELD HI TEMPS APRCHG 70 AWAY FM THE MODIFIYING
INFLUENCE OF LK MI WITH LLVL SLY FLOW...ESPECIALLY IN THE DOWNSLOPE
AREAS W OF MQT. SUSPECT AT LEAST SOME PLACES OVER THE W HALF MAY SEE
DAILY RECORD HI TEMPS.
WED NGT...AS THE SFC TROF/PACIFIC TYPE COLD FNT MOVES E ACRS THE
CWA...THE 00Z GFS AND ESPECIALLY THE CNDN MODELS ARE MOST AGGRESSIVE
AT GENERATING SOME PCPN OVER MAINLY THE SE ZNS UNDER AREA OF STEEPER
H7-5 LAPSE RATES UP TO 7.5-8.0C/KM AND SHOWALTER INDEX AS LO AS -2
TO -4C. THE CNDN INSTABILITY IS GREATER AS THIS MODEL SHOWS A
STRONGER SHRTWV MOVING ENEWD IN THE WSW FLOW ALF. ALTHOUGH THE TIME
OF DAY WOULD NOT BE CONDUCIVE TO TS...OPTED TO INCLUDE SCHC TS OVER
THE SE ZNS CONSIDERING THE ANOMALOUS LLVL WARMTH OF THE ANTECEDENT
AIRMASS/FCST STABILITY INDICES. DRIER AND SOMEWHAT COOLER AIR WL
ARRIVE OVER ESPECIALLY THE W IN THE WAKE OF THE COLD FROPA AS WEAK
HI PRES MOVES TO THE MN ARROWHEAD BY 12Z THU.
EXTENDED...THE STEADY SLY FLOW BTWN WRN TROF/ERN RDG WL PERSIST THRU
THE WEEKEND WITH NEAR UNPRECEDENTED WARMTH POSSIBLE FRI THRU SUN IN
THE PRESENCE OF H85 TEMPS NOT FAR FM 10-12C. THE THU-FRI PERIOD
SHOULD BE DRY WITH HI PRES RDG OVER THE AREA...BUT THERE WL BE A CHC
OF SHRA OVER THE WEEKEND AS HI PRES SHIFTS TO THE E. LACK OF
CONSISTENCY ON SHRTWV PRESENCE/TIMING SUGS NO MORE THAN CHC POPS ARE
WARRANTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 147 PM EDT MON MAR 12 2012
COMPLEX AVIATION FORECAST THIS AFTN AS MID LEVEL LOW CURRENTLY OVER
SE MN/SW WI MOVES NORTHEAST. DENSE FOG/VLIFR CONDITIONS HAVE SETTLED
INTO KCMX/KSAW UNDER LOCALLY UPSLOPING WINDS. WITH DOWNSLOPING WINDS
AT KIWD...CONDITIONS HAVE BEEN MVFR AND THAT SHOULD CONTINUE THIS
AFTN. AS NEXT ROUND OF SCT SHRA ARRIVES ALONG WITH SFC TROF...EXPECT
CONDITIONS TO IMPROVE TO MVFR AT KCMX/KSAW BY LATE AFTN. WIND SHIFT
TO SW WILL ALSO HELP IMPROVE CONDITIONS. AS THE LOW MOVES NE
OVERNIGHT...EXPECT A FAIRLY QUICK TRANSITION TO CLEAR SKIES UNDER
STRONG DRYING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 AM EDT MON MAR 12 2012
UPPER LEVEL DISTURBANCE AND SURFACE TROUGH WILL SLIDE NE ACROSS
LAKE SUPERIOR THIS AFTERNOON AND TONIGHT. EXPECT SSE WINDS TO
MAINLY STAY BELOW 20KTS...BUT THERE COULD BE A FEW GUSTS TO 25KTS
OVER THE NRN LK. AS WARM/MOIST AIR MOVES OVER LAKE SUPERIOR
TODAY...SHOULD SEE AREAS OF FOG DEVELOP LATE THIS MORNING AND
CONTINUE INTO THIS EVENING. BEHIND THE SURFACE TROUGH...EXPECT
WINDS TO INCREASE OUT OF THE WEST AFTER MIDNIGHT AND CONTINUE INTO
TUESDAY. WARM AIR ABOVE THE SURFACE WILL LIKELY KEEP THE MARINE
LAYER IN PLACE AND LIMIT THE VERY STRONG WINDS ALOFT FROM
REACHING THE SURFACE. AT THIS TIME...ONLY HAVE GUSTS REACHING
30KTS. AFTER TUESDAY...WINDS WILL REMAIN UNDER 25KTS WITH A
RELATIVELY WEAK PRESSURE GRADIENT IN PLACE.
&&
.HYDROLOGY...
ISSUED AT 411 AM EDT MON MAR 12 2012
NEAR RECORD TO RECORD SETTING TEMPS YESTERDAY HAS HELPED RIPEN THE
SNOW PACK. RAIN TODAY AND FOR PARTS OF TONIGHT WILL PROVIDE
ADDITIONAL MOISTURE TO THE AREA. EXPECT THE BULK OF THE
RAIN TO FALL DURING THE MORNING TO EARLY AFTERNOON HOURS...WITH
ACCUMULATIONS OF AROUND 0.25 TO 0.40IN. THE RAIN...COMBINED
WITH DEWPOINTS RISING INTO THE 40S...WILL HELP TO QUICKEN
SNOWMELT. AS OF THIS MORNING...THERE HAS BEEN ONLY LIMITED
RESPONSES ON THE LARGER RIVERS.
THE RAIN AND SNOW MELT TODAY...COMBINED WITH ABOVE NORMAL
TEMPERATURES THROUGH NEXT WEEKEND WILL LEAD TO A INCREASE IN
RIVER AND STREAM LEVELS OVER THE NEXT SEVERAL DAYS. EXPECT SOME OF
THE RIVERS ACROSS THE AREA TO EXCEED THEIR BANKS BY THE END OF THIS
WEEK. PERSONS LIVING NEAR RIVERS AND STREAMS SHOULD
MONITOR THE LATEST RIVER CONDITIONS AND USE CAUTION IF WALKING
ALONG RIVER BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
ICE JAM WISE...NOT MUCH ICE HAS BEEN NOTED BY OBSERVERS ON THE
FASTER FLOWING RIVERS OVER NRN UPPER MI. BUT THE FORD RIVER...BOTH
AT HYDE AND THE MOUTH AT LK MI...STILL HAS GOOD ICE COVER THAT
LEADS TO SOME CONCERN FOR ICE JAM POTENTIAL WITH THE FASTER RUNOFF.
ALTHOUGH LIMITED SNOW WAS NOTED NEAR LK MI...THERE IS STILL 4-9IN
OF SNOW ...AND NOHRSC ESTIMATED AROUND 1.25IN OF LIQUID...TOWARDS
THE HEADWATERS THAT WILL BE MELTED OVER THE COMING DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...ROLFSON
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
333 PM EDT MON MAR 12 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED OFFSHORE WILL CONTINUE TO EXTEND WESTWARD
INTO THE CAROLINAS THROUGH TONIGHT. A WEAK SURFACE TROUGH AND UPPER
LEVEL DISTURBANCE WILL PROGRESS INTO THE AREA FROM THE WEST ON
TUESDAY. A GENERAL WARMING TREND IS EXPECTED THROUGH MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 PM MONDAY...
THIS AFTERNOON:
THE PROGRESSIVE UPPER LOW CURRENTLY IN THE NORTHERN MS RIVER VALLEY
WILL TRACK NORTHEAST INTO ONTARIO TODAY...WHILE ADDITIONAL SHORTWAVE
ENERGY CURRENTLY OVER SASKATCHEWAN/MONTANA PROGRESSES EAST TOWARD
MANITOBA. HEIGHT FALLS (ASSOC/W THE AFOREMENTIONED UPPER LOW) OVER
THE OH VALLEY/MID-ATLANTIC WILL PUSH THE H5 RIDGE OFFSHORE
TODAY...WITH INCREASINGLY WESTERLY FLOW ALOFT OVER CENTRAL NC. A
MINOR SHORTWAVE WAS PRESENT UPSTREAM OVER OKLAHOMA AT 15Z...AND IS
PROGGED TO PROGRESS EAST INTO THE WESTERN TN VALLEY BY 00Z THIS
EVENING. THE LATEST RUC MODEL DATA SHOWED A MID-LEVEL VORTICITY
MAXIMUM OVER THE DEEP SOUTH AT 15Z...APPARENTLY EMANATING FROM DEEP
CONVECTION/STRONG MID-LEVEL LATENT HEATING PRESENT OVER THE LA/MS
GULF COAST THIS MORNING...AND THE RUC SHOWS THIS FEATURE PROGRESSING
NORTHEAST INTO GA/UPSTATE SC/WESTERN NC BY 00Z THIS EVENING. IN THE
LOWER LEVELS...A 5-10 KT SOUTHERLY RETURN FLOW WILL PREVAIL OVER THE
AREA...ON THE WESTERN PERIPHERY OF THE LOW-LEVEL RIDGE AXIS NOW
CENTERED OFFSHORE THE CAROLINA COAST. W/REGARD TO PRECIP CHANCES...
LITTLE OR NO FORCING FOR ASCENT WILL BE PRESENT THIS AFTERNOON...
ASIDE FROM VERY WEAK/BROAD WARM ADVECTION ASSOC/W SOUTHERLY RETURN
FLOW. INCREASING MID/UPPER LEVEL CLOUD COVER (LIMITING INSOLATION IN
THE WEST) AND A LINGERING MID-LEVEL SUBSIDENCE INVERSION (ASSOC/W
THE DEPARTING H5 RIDGE AXIS IN THE EAST) SHOULD SIGNIFICANTLY HAMPER
ANY DIURNAL DESTABILIZATION THIS AFTERNOON...WITH VERY LITTLE OR NO
AVAILABLE INSTABILITY. AS A RESULT...EXPECT A DRY FORECAST THROUGH
00Z THIS EVENING. HIGHS WILL PRIMARILY DEPEND ON THE TIMING AND
COVERAGE OF MID/UPPER LEVEL CLOUD COVER SLOWLY PROGRESSING INTO THE
AREA FROM THE WEST. WILL FCST HIGHS RANGING FROM THE MID/UPPER 60S
(W/NW PIEDMONT) TO UPPER 60S/LOWER 70S ELSEWHERE.
TONIGHT:
UNCERTAINTY INCREASES TONIGHT...PRIMARILY WITH THE PRECIPITATION
FORECAST. FORCING FOR ASCENT OVER CENTRAL NC OVERNIGHT WILL
GENERALLY BE LIMITED TO WEAK/BROAD MID-LEVEL HEIGHT FALLS AND
LOW-LEVEL WARM ADVECTION. W/REGARD TO THERMODYNAMICS...WEAK
MID-LEVEL LAPSE RATES AND BAD DIURNAL TIMING WILL CONTRIBUTE TO VERY
LITTLE OR NO AVAILABLE INSTABILITY OVERNIGHT. THE ABOVE ALONE WOULD
ARGUE FOR VERY LITTLE OR NO CHANCE OF SHOWER ACTIVITY OVERNIGHT...
AND VIRTUALLY NO CHANCE OF THUNDER. HOWEVER...THE MID-LEVEL
VORTICITY MAXIMUM THAT DEVELOPED IN ASSOC/W DEEP CONVECTION UPSTREAM
OF THE AREA THIS MORNING IS PROGGED TO APPROACH THE WEST/SW PIEDMONT
BY ~00Z...PROGRESSING THROUGH CENTRAL NC OVERNIGHT. DESPITE POOR
THERMODYNAMICS AND WEAK BACKGROUND/SYNOPTIC ASCENT...DPVA ASSOC/W
THIS FEATURE WILL PROVIDE ADDITIONAL/FOCUSED FORCING...AND ISOLD/SCT
SHOWER ACTIVITY WILL CERTAINLY BE POSSIBLE. THE LATEST 12Z WRF-NMM
SIMULATED REFLECTIVITY PRODUCT IS MORE ROBUST THAN THE 00Z RUN IN
SHOWING SHOWER ACTIVITY DEVELOPING OVERNIGHT IN ASSOC/W THIS FEATURE.
ADDITIONALLY...THE SHORTWAVE CURRENTLY IN OKLAHOMA WILL APPROACH THE
SOUTHERN APPALACHIANS BY ~12Z TUE...AND SOME WEAK AMPLIFICATION WILL
BE POSSIBLE AS ADDITIONAL UPPER LEVEL ENERGY PROGRESSES FROM THE
DESERT SOUTHWEST INTO THE TN VALLEY. THIS COULD PROVIDE ADDITIONAL
FORCING FOR ASCENT FROM THE WEST CLOSE TO SUNRISE TUE MORNING...
ALTHOUGH THE LATEST GUIDANCE CONTINUES TO SUGGEST THE BEST FORCING
ASSOC/W THE SECOND WAVE WILL MOST LIKELY OCCUR AFTER SUNRISE...
DURING THE DAY TUE. WITH THE ABOVE IN MIND...FEEL THAT A SMALL
INCREASE IN PRECIP CHANCES IS WARRANTED OVERNIGHT...AND WILL
INDICATE A 30% CHANCE OF SHOWERS EVERYWHERE. DESPITE THE PRESENCE OF
AN UPPER LEVEL DISTURBANCE...GIVEN POOR DIURNAL TIMING AND WEAK/
INCREASINGLY MOIST ADIABATIC LAPSE RATES...LITTLE IF ANY INSTABILITY
IS EXPECTED...AND WILL LEAVE OUT MENTION OF THUNDER. WITH MOSTLY
CLOUDY OR OVERCAST SKIES...EXPECT LOWS MUCH WARMER THAN IN RECENT
DAYS...IN THE LOWER/MID 50S. -VINCENT
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 330 PM MONDAY...
TUESDAY:
AS MENTIONED IN THE NEAR TERM DISCUSSION...AN AMPLIFYING SHORTWAVE
IS EXPECTED TO PROGRESS EASTWARD ACROSS THE CAROLINAS DURING THE DAY
TUE...THOUGH THE EXACT TIMING REMAINS SOMEWHAT UNCERTAIN. IN THE
LOWER LEVELS...A PIEDMONT TROUGH DURING IS PROGGED TO DEVELOP DURING
PEAK HEATING. OTHERWISE...LIFT WILL BE CONFINED TO VERY WEAK/BROAD
LOW-LEVEL WARM ADVECTION AND MID-LEVEL HEIGHT FALLS. W/REGARD TO
THERMODYNAMICS...DESTABILIZATION WILL LIKELY BE HAMPERED BY
PERVASIVE CLOUD COVER THROUGH MUCH OF THE DAY...PARTICULARLY EAST OF
HIGHWAY 1. SOME CLEARING IS EXPECTED IN THE WEST/NW PIEDMONT BY ~18Z
IN THE PRESENCE OF A CONTINUED MOIST BOUNDARY LAYER...AND
INSTABILITY COULD ACTUALLY BE MORE FAVORABLE WEST OF HWY 1.
HOWEVER...SIGNIFICANT DRYING ALOFT IS ALSO EXPECTED AS A MUCH DRIER
MID/UPPER LEVEL AIRMASS ADVECTS INTO WESTERN PORTIONS OF THE STATE
TUE AFTERNOON...AND DRY AIR ENTRAINMENT MAY OFFSET OR COMPLETELY
NEGATE THE BENEFIT OF BETTER INSOLATION. REGARDLESS...WITH WEAK
MID-LEVEL LAPSE RATES OVER MOST OF THE AREA (ASIDE FROM WEST/NW
PIEDMONT) DURING PEAK HEATING...MLCAPE VALUES WILL LIKELY NOT EXCEED
250-500 J/KG. WITH THE ABOVE IN MIND...EXPECT SUFFICIENT FORCING AND
INSTABILITY TO WARRANT AT LEAST A LOW CHANCE (20-30%) OF SHOWERS/
STORMS...WITH THE BEST CHANCE OF THUNDER EAST OF HIGHWAY 1.
HOWEVER...IF FORCING ASSOC/W THE UPPER LEVEL WAVE IS STRONG ENOUGH
TO OVERCOME THE SIGNIFICANT AMOUNT OF DRY AIR ALOFT PROGGED IN THE
WEST/NW PIEDMONT...THUNDER WILL BE POSSIBLE THERE AS WELL. GIVEN
MARGINAL INSTABILITY...0-6 KM BULK SHEAR VALUES NO HIGHER THAN 20-25
KT (BARELY SUPPORTIVE OF MULTICELLULAR CONVECTION)...AND A
RELATIVELY SHALLOW MIXED LAYER WITH LITTLE POTENTIAL FOR
EVAPORATIVELY ENHANCED DOWNDRAFTS...DO NOT ANTICIPATE A SEVERE
THREAT WITH ANY CONVECTION. EXPECT HIGHS ON TUE TO RANGE FROM THE
UPPER 60S/LOWER 70S IN THE EAST TO THE LOWER/MID 70S IN THE WEST.
TUESDAY NIGHT:
SUBSIDENCE AND SHORTWAVE RIDGING BUILDING INTO THE AREA IN THE WAKE
OF THE SHORTWAVE SHOULD RESULT IN MOSTLY CLEAR SKIES TUE NIGHT.
GIVEN A WEAK/BAGGY MSLP GRADIENT AND THE CONTINUED PRESENCE OF A
MOIST BOUNDARY LAYER...ANTICIPATE A POTENTIAL FOR FOG ACROSS THE
AREA 06-12Z WED MORNING...ESPECIALLY IN AREAS THAT RECEIVE RAINFALL
DURING THE DAY TUE. EXPECT LOWS IN THE LOWER/MID 50S. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 230 PM MONDAY...
AS SURFACE SYSTEM MOVES OFFSHORE EARLY WEDNESDAY...WARM AIR WILL BE
SPREADING NORTH DUE TO SUBTROPICAL RIDGING INTO THE SOUTHERN PLAINS
AND WESTERN GULF STATES. HIGHS WEDNESDAY WILL BE 15 TO 20 DEGREES
ABOVE NORMAL...UPPER 70S OVER MOST OF THE AREA. MOISTURE WILL BE
BUILDING NORTH INTO THE TENNESSEE VALLEY AND POOLING ON THE WESTERN
SLOPES AS THE RIDGE HOLDS TIGHT THROUGH THURSDAY...INSTABILITY WILL
BE MINIMAL AND CAPPED...PROVIDING ANOTHER WARM DRY DAY WITH HIGHS IN
THE UPPER 70S TO LOWER 80S AFTER MILD MORNING LOWS IN THE LOWER 50S.
A MID LEVEL WAVE ORIGINATING IN THE SOUTHERN PLAINS WILL BE
DAMPENING THE RIDGE AMPLITUDE WITH WEAK SURFACE HIGH PRESSURE
SHIFTING OFFSHORE. THIS WILL PRODUCE A SLIGHT CHANCE OF SHOWERS
THURSDAY NIGHT...WITH A LITTLE BETTER CHANCES ON FRIDAY AS A WEAK
SURFACE FRONT EDGES VERY SLOWLY SOUTH AND EAST INTO THE MID ATLANTIC
REGION. PROGGED INSTABILITY IS SUFFICIENT FOR THUNDER GIVEN THE LOW
LEVEL FORCING AS HIGHS FRIDAY WILL STILL BE ON THE WARM SIDE...MID
TO UPPER 70S.
THE SURFACE FRONT WILL SAG FURTHER SOUTH ON SATURDAY AS LOW PRESSURE
AREA DEVELOPS OFF THE MID ATLANTIC COAST...WILL MAINTAIN SLIGHT
CHANCE TO CHANCE POPS ACROSS THE AREA THROUGH SATURDAY...AGAIN WITH
A CHANCE OF THUNDER GIVEN THE WARM AIRMASS AND POTENTIAL FOR THE
FRONT TO STALL OVER THE AREA. HIGHS WILL STILL BE IN THE MID TO
UPPER 70S.
THE FRONTS WILL BE SHOVED SOUTH OF THE AREA...SATURDAY NIGHT OR
SUNDAY AND WILL MAINTAIN SLIGHT CHANCES TO COVER THE TIMING
UNCERTAINTY. HIGH PRESSURE WILL WEDGE DOWN THE COAST SUNDAY/MONDAY
AND WILL TAPER OFF THE POPS SUNDAY NIGHT AND LEAVE MONDAY DRY FOR
NOW. HIGHS SUNDAY WILL BE IN THE LOW TO MID 70S WITH COOLER TEMPS IN
THE NORTHEAST WITH LINGERING CLOUD COVERAGE AND COOL AIR WEDGING
IN...WITH HIGHS ON MONDAY A TOUCH COOLER...LOWER 70S ACROSS THE
AREA.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 215 PM MONDAY...
24-HR TAF PERIOD:
VFR CONDITIONS ARE EXPECTED TO PREDOMINATE THROUGH 00Z THIS
EVENING...WITH SUB-VFR CONDITIONS POSSIBLE OVERNIGHT INTO TUESDAY.
VFR CEILINGS BETWEEN 3000-5000 FT WERE OBSERVED OVER MOST OF CENTRAL
NC AS OF 18Z THIS AFTERNOON. EXPECT CEILINGS TO REMAIN VFR OR
BORDERLINE MVFR AT BEST THROUGH 00Z THIS EVENING. TONIGHT...AN UPPER
LEVEL DISTURBANCE APPROACHING THE AREA FROM THE SOUTHWEST MAY HELP
ISOLD/SCT SHOWER ACTIVITY DEVELOP ACROSS THE AREA...THOUGH ENOUGH
UNCERTAINTY REMAINS TO PRECLUDE MENTION OF SHOWERS IN THE 18Z TAF
ISSUANCE. ADDITIONALLY...SOUTHWESTERLY RETURN FLOW AND WARM
ADVECTION IN THE LOWER LEVELS COULD RESULT IN THE DEVELOPMENT OF
MVFR/IFR CEILINGS ACROSS PORTIONS OF THE AREA OVERNIGHT. ALTHOUGH
SUB-VFR CONDITIONS WILL BE POSSIBLE EVERYWHERE...AT THIS TIME THE
BEST CHANCE THROUGH 12Z TUE APPEARS TO BE AT THE INT/GSO/RDU TAF
SITES. AFTER SUNRISE TUESDAY...THE FAY/RWI TAF SITES WILL HAVE THE
RELATIVE BEST CHANCE OF ISOLD/SCT SHOWER ACTIVITY AND SUB-VFR
CEILINGS. AN ISOLD THUNDERSTORM CANNOT BE RULED OUT AT FAY/RWI NEAR
OR PRIOR TO 18Z TUE. WINDS WILL BE SOUTHWEST AT ~10 KT THIS
AFTERNOON...WEAKENING TO ~5 KT OVERNIGHT...INCREASING TO ~10 KT
AGAIN ON TUE.
LOOKING AHEAD:
SUB-VFR CEILINGS OR FOG WILL BE POSSIBLE TUE NIGHT GIVEN MID/UPPER
LEVEL DRYING (CLEARING SKIES) IN THE PRESENCE OF A MOIST BOUNDARY
LAYER AND LIGHT/CALM WINDS. EXPECT VFR CONDITIONS TO PREVAIL WED
THROUGH THU IN ASSOC/W HIGH PRESSURE AND A RELATIVELY DRIER AIRMASS
IN PLACE. AFTER A BRIEF POTENTIAL FOR FOG FRIDAY MORNING...SHOWERS
AND STORMS WILL BE POSSIBLE FRI/FRI NIGHT AND POSSIBLY INTO SAT IN
ASSOC/W AN UPPER LEVEL DISTURBANCE AND SURFACE TROUGH PROGGED TO
PROGRESS THROUGH THE AREA. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...MLM
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EDT MON MAR 12 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED OFFSHORE WILL CONTINUE TO EXTEND WESTWARD
INTO THE CAROLINAS THROUGH TONIGHT. A WEAK SURFACE TROUGH AND UPPER
LEVEL DISTURBANCE WILL PROGRESS INTO THE AREA FROM THE WEST ON
TUESDAY. A GENERAL WARMING TREND IS EXPECTED THROUGH MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 PM MONDAY...
THIS AFTERNOON:
THE PROGRESSIVE UPPER LOW CURRENTLY IN THE NORTHERN MS RIVER VALLEY
WILL TRACK NORTHEAST INTO ONTARIO TODAY...WHILE ADDITIONAL SHORTWAVE
ENERGY CURRENTLY OVER SASKATCHEWAN/MONTANA PROGRESSES EAST TOWARD
MANITOBA. HEIGHT FALLS (ASSOC/W THE AFOREMENTIONED UPPER LOW) OVER
THE OH VALLEY/MID-ATLANTIC WILL PUSH THE H5 RIDGE OFFSHORE
TODAY...WITH INCREASINGLY WESTERLY FLOW ALOFT OVER CENTRAL NC. A
MINOR SHORTWAVE WAS PRESENT UPSTREAM OVER OKLAHOMA AT 15Z...AND IS
PROGGED TO PROGRESS EAST INTO THE WESTERN TN VALLEY BY 00Z THIS
EVENING. THE LATEST RUC MODEL DATA SHOWED A MID-LEVEL VORTICITY
MAXIMUM OVER THE DEEP SOUTH AT 15Z...APPARENTLY EMANATING FROM DEEP
CONVECTION/STRONG MID-LEVEL LATENT HEATING PRESENT OVER THE LA/MS
GULF COAST THIS MORNING...AND THE RUC SHOWS THIS FEATURE PROGRESSING
NORTHEAST INTO GA/UPSTATE SC/WESTERN NC BY 00Z THIS EVENING. IN THE
LOWER LEVELS...A 5-10 KT SOUTHERLY RETURN FLOW WILL PREVAIL OVER THE
AREA...ON THE WESTERN PERIPHERY OF THE LOW-LEVEL RIDGE AXIS NOW
CENTERED OFFSHORE THE CAROLINA COAST. W/REGARD TO PRECIP CHANCES...
LITTLE OR NO FORCING FOR ASCENT WILL BE PRESENT THIS AFTERNOON...
ASIDE FROM VERY WEAK/BROAD WARM ADVECTION ASSOC/W SOUTHERLY RETURN
FLOW. INCREASING MID/UPPER LEVEL CLOUD COVER (LIMITING INSOLATION IN
THE WEST) AND A LINGERING MID-LEVEL SUBSIDENCE INVERSION (ASSOC/W
THE DEPARTING H5 RIDGE AXIS IN THE EAST) SHOULD SIGNIFICANTLY HAMPER
ANY DIURNAL DESTABILIZATION THIS AFTERNOON...WITH VERY LITTLE OR NO
AVAILABLE INSTABILITY. AS A RESULT...EXPECT A DRY FORECAST THROUGH
00Z THIS EVENING. HIGHS WILL PRIMARILY DEPEND ON THE TIMING AND
COVERAGE OF MID/UPPER LEVEL CLOUD COVER SLOWLY PROGRESSING INTO THE
AREA FROM THE WEST. WILL FCST HIGHS RANGING FROM THE MID/UPPER 60S
(W/NW PIEDMONT) TO UPPER 60S/LOWER 70S ELSEWHERE.
TONIGHT:
UNCERTAINTY INCREASES TONIGHT...PRIMARILY WITH THE PRECIPITATION
FORECAST. FORCING FOR ASCENT OVER CENTRAL NC OVERNIGHT WILL
GENERALLY BE LIMITED TO WEAK/BROAD MID-LEVEL HEIGHT FALLS AND
LOW-LEVEL WARM ADVECTION. W/REGARD TO THERMODYNAMICS...WEAK
MID-LEVEL LAPSE RATES AND BAD DIURNAL TIMING WILL CONTRIBUTE TO VERY
LITTLE OR NO AVAILABLE INSTABILITY OVERNIGHT. THE ABOVE ALONE WOULD
ARGUE FOR VERY LITTLE OR NO CHANCE OF SHOWER ACTIVITY OVERNIGHT...
AND VIRTUALLY NO CHANCE OF THUNDER. HOWEVER...THE MID-LEVEL
VORTICITY MAXIMUM THAT DEVELOPED IN ASSOC/W DEEP CONVECTION UPSTREAM
OF THE AREA THIS MORNING IS PROGGED TO APPROACH THE WEST/SW PIEDMONT
BY ~00Z...PROGRESSING THROUGH CENTRAL NC OVERNIGHT. DESPITE POOR
THERMODYNAMICS AND WEAK BACKGROUND/SYNOPTIC ASCENT...DPVA ASSOC/W
THIS FEATURE WILL PROVIDE ADDITIONAL/FOCUSED FORCING...AND ISOLD/SCT
SHOWER ACTIVITY WILL CERTAINLY BE POSSIBLE. THE LATEST 12Z WRF-NMM
SIMULATED REFLECTIVITY PRODUCT IS MORE ROBUST THAN THE 00Z RUN IN
SHOWING SHOWER ACTIVITY DEVELOPING OVERNIGHT IN ASSOC/W THIS FEATURE.
ADDITIONALLY...THE SHORTWAVE CURRENTLY IN OKLAHOMA WILL APPROACH THE
SOUTHERN APPALACHIANS BY ~12Z TUE...AND SOME WEAK AMPLIFICATION WILL
BE POSSIBLE AS ADDITIONAL UPPER LEVEL ENERGY PROGRESSES FROM THE
DESERT SOUTHWEST INTO THE TN VALLEY. THIS COULD PROVIDE ADDITIONAL
FORCING FOR ASCENT FROM THE WEST CLOSE TO SUNRISE TUE MORNING...
ALTHOUGH THE LATEST GUIDANCE CONTINUES TO SUGGEST THE BEST FORCING
ASSOC/W THE SECOND WAVE WILL MOST LIKELY OCCUR AFTER SUNRISE...
DURING THE DAY TUE. WITH THE ABOVE IN MIND...FEEL THAT A SMALL
INCREASE IN PRECIP CHANCES IS WARRANTED OVERNIGHT...AND WILL
INDICATE A 30% CHANCE OF SHOWERS EVERYWHERE. DESPITE THE PRESENCE OF
AN UPPER LEVEL DISTURBANCE...GIVEN POOR DIURNAL TIMING AND WEAK/
INCREASINGLY MOIST ADIABATIC LAPSE RATES...LITTLE IF ANY INSTABILITY
IS EXPECTED...AND WILL LEAVE OUT MENTION OF THUNDER. WITH MOSTLY
CLOUDY OR OVERCAST SKIES...EXPECT LOWS MUCH WARMER THAN IN RECENT
DAYS...IN THE LOWER/MID 50S. -VINCENT
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM MONDAY...
OVERNIGHT SHOWERS SHOULD BE MOVING INTO THE NORTHERN COASTAL PLAIN
BY AROUND 12Z TUESDAY MORNING AS THE FIRST ROUND OF FORCING
ASSOCIATED WITH A SHORTWAVE CROSSING THE GREAT LAKES MOVES OFF THE
MID ATLANTIC COAST. WESTERLY MID LEVEL FLOW BRING DRIER MID LEVEL
AIR ACROSS THE CWA DURING THE DAY...WITH A WEAK LEE TROUGH
DEVELOPING OVER THE WESTERN PIEDMONT/FOOTHILLS. A SECOND...LOW
AMPLITUDE UPPER TROUGH/DISTURBANCE IS THEN FORECAST TO CROSS THE
AREA BETWEEN 15 AND 21Z. BECAUSE THE ORIGINAL COLD FRONT WILL
ESSENTIALLY WASH OUT AS IT CROSS THE MOUNTAINS...LOW LEVEL MOISTURE
WILL CHANGE VERY LITTLE DURING THE DAY TUESDAY. STRONG HEATING
WILL ALLOW TEMPS TO RISE INTO THE LOW TO MID 70S WITH DEWPOINTS
HOLDING IN THE MID 50S. THIS DAYTIME HEATING COMBINED WITH SLIGHTLY
STEEPER MID LEVEL LAPSE RATES SHOULD LEAD TO ANOTHER ROUND OF
ISOLATED SHOWERS...FOCUSED MAINLY NEAR THE LEE TROUGH AND AIDED BY
THE AFOREMENTIONED WEAK UPPER TROUGH PASSAGE. THE MUCH DRIER MID
LEVEL AIR WILL LIMIT COVERAGE...BUT 400-800 J/KG MAY SUPPORT A FEW
ISOLATED THUNDERSTORMS OVER THE WESTERN PIEDMONT. WEAK DEEP LAYER
SHEAR AND THIN CAPE PROFILES SHOULD PRECLUDE ANY SEVERE STORMS...BUT
DOWNDRAFT CAPE COULD CLIMB INTO THE 500-1000 J/KG RANGE AND SUPPORT
SOME ENHANCED WIND GUSTS. BASED ON THE LIMITED COVERAGE
EXPECTED...WE WILL CONTINUE THE SLIGHT CHANCE POP ADVERTISED.
ANOTHER MILD NIGHT EXPECTED TUESDAY NIGHT AS SHOWERS COME TO AN END
BUT LOW LEVEL MOISTURE REMAINS IN PLACE. SOME FOG MAY BE POSSIBLE
IN THE EAST AS WINDS BECOME LIGHT. LOWS IN THE LOW TO MID 50S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 230 PM MONDAY...
AS SURFACE SYSTEM MOVES OFFSHORE EARLY WEDNESDAY...WARM AIR WILL BE
SPREADING NORTH DUE TO SUBTROPICAL RIDGING INTO THE SOUTHERN PLAINS
AND WESTERN GULF STATES. HIGHS WEDNESDAY WILL BE 15 TO 20 DEGREES
ABOVE NORMAL...UPPER 70S OVER MOST OF THE AREA. MOISTURE WILL BE
BUILDING NORTH INTO THE TENNESSEE VALLEY AND POOLING ON THE WESTERN
SLOPES AS THE RIDGE HOLDS TIGHT THROUGH THURSDAY...INSTABILITY WILL
BE MINIMAL AND CAPPED...PROVIDING ANOTHER WARM DRY DAY WITH HIGHS IN
THE UPPER 70S TO LOWER 80S AFTER MILD MORNING LOWS IN THE LOWER 50S.
A MID LEVEL WAVE ORIGINATING IN THE SOUTHERN PLAINS WILL BE
DAMPENING THE RIDGE AMPLITUDE WITH WEAK SURFACE HIGH PRESSURE
SHIFTING OFFSHORE. THIS WILL PRODUCE A SLIGHT CHANCE OF SHOWERS
THURSDAY NIGHT...WITH A LITTLE BETTER CHANCES ON FRIDAY AS A WEAK
SURFACE FRONT EDGES VERY SLOWLY SOUTH AND EAST INTO THE MID ATLANTIC
REGION. PROGGED INSTABILITY IS SUFFICIENT FOR THUNDER GIVEN THE LOW
LEVEL FORCING AS HIGHS FRIDAY WILL STILL BE ON THE WARM SIDE...MID
TO UPPER 70S.
THE SURFACE FRONT WILL SAG FURTHER SOUTH ON SATURDAY AS LOW PRESSURE
AREA DEVELOPS OFF THE MID ATLANTIC COAST...WILL MAINTAIN SLIGHT
CHANCE TO CHANCE POPS ACROSS THE AREA THROUGH SATURDAY...AGAIN WITH
A CHANCE OF THUNDER GIVEN THE WARM AIRMASS AND POTENTIAL FOR THE
FRONT TO STALL OVER THE AREA. HIGHS WILL STILL BE IN THE MID TO
UPPER 70S.
THE FRONTS WILL BE SHOVED SOUTH OF THE AREA...SATURDAY NIGHT OR
SUNDAY AND WILL MAINTAIN SLIGHT CHANCES TO COVER THE TIMING
UNCERTAINTY. HIGH PRESSURE WILL WEDGE DOWN THE COAST SUNDAY/MONDAY
AND WILL TAPER OFF THE POPS SUNDAY NIGHT AND LEAVE MONDAY DRY FOR
NOW. HIGHS SUNDAY WILL BE IN THE LOW TO MID 70S WITH COOLER TEMPS IN
THE NORTHEAST WITH LINGERING CLOUD COVERAGE AND COOL AIR WEDGING
IN...WITH HIGHS ON MONDAY A TOUCH COOLER...LOWER 70S ACROSS THE
AREA.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 215 PM MONDAY...
24-HR TAF PERIOD:
VFR CONDITIONS ARE EXPECTED TO PREDOMINATE THROUGH 00Z THIS
EVENING...WITH SUB-VFR CONDITIONS POSSIBLE OVERNIGHT INTO TUESDAY.
VFR CEILINGS BETWEEN 3000-5000 FT WERE OBSERVED OVER MOST OF CENTRAL
NC AS OF 18Z THIS AFTERNOON. EXPECT CEILINGS TO REMAIN VFR OR
BORDERLINE MVFR AT BEST THROUGH 00Z THIS EVENING. TONIGHT...AN UPPER
LEVEL DISTURBANCE APPROACHING THE AREA FROM THE SOUTHWEST MAY HELP
ISOLD/SCT SHOWER ACTIVITY DEVELOP ACROSS THE AREA...THOUGH ENOUGH
UNCERTAINTY REMAINS TO PRECLUDE MENTION OF SHOWERS IN THE 18Z TAF
ISSUANCE. ADDITIONALLY...SOUTHWESTERLY RETURN FLOW AND WARM
ADVECTION IN THE LOWER LEVELS COULD RESULT IN THE DEVELOPMENT OF
MVFR/IFR CEILINGS ACROSS PORTIONS OF THE AREA OVERNIGHT. ALTHOUGH
SUB-VFR CONDITIONS WILL BE POSSIBLE EVERYWHERE...AT THIS TIME THE
BEST CHANCE THROUGH 12Z TUE APPEARS TO BE AT THE INT/GSO/RDU TAF
SITES. AFTER SUNRISE TUESDAY...THE FAY/RWI TAF SITES WILL HAVE THE
RELATIVE BEST CHANCE OF ISOLD/SCT SHOWER ACTIVITY AND SUB-VFR
CEILINGS. AN ISOLD THUNDERSTORM CANNOT BE RULED OUT AT FAY/RWI NEAR
OR PRIOR TO 18Z TUE. WINDS WILL BE SOUTHWEST AT ~10 KT THIS
AFTERNOON...WEAKENING TO ~5 KT OVERNIGHT...INCREASING TO ~10 KT
AGAIN ON TUE.
LOOKING AHEAD:
SUB-VFR CEILINGS OR FOG WILL BE POSSIBLE TUE NIGHT GIVEN MID/UPPER
LEVEL DRYING (CLEARING SKIES) IN THE PRESENCE OF A MOIST BOUNDARY
LAYER AND LIGHT/CALM WINDS. EXPECT VFR CONDITIONS TO PREVAIL WED
THROUGH THU IN ASSOC/W HIGH PRESSURE AND A RELATIVELY DRIER AIRMASS
IN PLACE. AFTER A BRIEF POTENTIAL FOR FOG FRIDAY MORNING...SHOWERS
AND STORMS WILL BE POSSIBLE FRI/FRI NIGHT AND POSSIBLY INTO SAT IN
ASSOC/W AN UPPER LEVEL DISTURBANCE AND SURFACE TROUGH PROGGED TO
PROGRESS THROUGH THE AREA. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH
LONG TERM...MLM
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
215 PM EDT MON MAR 12 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED OFFSHORE WILL CONTINUE TO EXTEND WESTWARD
INTO THE CAROLINAS THROUGH TONIGHT. A WEAK SURFACE TROUGH AND UPPER
LEVEL DISTURBANCE WILL PROGRESS INTO THE AREA FROM THE WEST ON
TUESDAY. A GENERAL WARMING TREND IS EXPECTED THROUGH MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 PM MONDAY...
THIS AFTERNOON:
THE PROGRESSIVE UPPER LOW CURRENTLY IN THE NORTHERN MS RIVER VALLEY
WILL TRACK NORTHEAST INTO ONTARIO TODAY...WHILE ADDITIONAL SHORTWAVE
ENERGY CURRENTLY OVER SASKATCHEWAN/MONTANA PROGRESSES EAST TOWARD
MANITOBA. HEIGHT FALLS (ASSOC/W THE AFOREMENTIONED UPPER LOW) OVER
THE OH VALLEY/MID-ATLANTIC WILL PUSH THE H5 RIDGE OFFSHORE
TODAY...WITH INCREASINGLY WESTERLY FLOW ALOFT OVER CENTRAL NC. A
MINOR SHORTWAVE WAS PRESENT UPSTREAM OVER OKLAHOMA AT 15Z...AND IS
PROGGED TO PROGRESS EAST INTO THE WESTERN TN VALLEY BY 00Z THIS
EVENING. THE LATEST RUC MODEL DATA SHOWED A MID-LEVEL VORTICITY
MAXIMUM OVER THE DEEP SOUTH AT 15Z...APPARENTLY EMANATING FROM DEEP
CONVECTION/STRONG MID-LEVEL LATENT HEATING PRESENT OVER THE LA/MS
GULF COAST THIS MORNING...AND THE RUC SHOWS THIS FEATURE PROGRESSING
NORTHEAST INTO GA/UPSTATE SC/WESTERN NC BY 00Z THIS EVENING. IN THE
LOWER LEVELS...A 5-10 KT SOUTHERLY RETURN FLOW WILL PREVAIL OVER THE
AREA...ON THE WESTERN PERIPHERY OF THE LOW-LEVEL RIDGE AXIS NOW
CENTERED OFFSHORE THE CAROLINA COAST. W/REGARD TO PRECIP CHANCES...
LITTLE OR NO FORCING FOR ASCENT WILL BE PRESENT THIS AFTERNOON...
ASIDE FROM VERY WEAK/BROAD WARM ADVECTION ASSOC/W SOUTHERLY RETURN
FLOW. INCREASING MID/UPPER LEVEL CLOUD COVER (LIMITING INSOLATION IN
THE WEST) AND A LINGERING MID-LEVEL SUBSIDENCE INVERSION (ASSOC/W
THE DEPARTING H5 RIDGE AXIS IN THE EAST) SHOULD SIGNIFICANTLY HAMPER
ANY DIURNAL DESTABILIZATION THIS AFTERNOON...WITH VERY LITTLE OR NO
AVAILABLE INSTABILITY. AS A RESULT...EXPECT A DRY FORECAST THROUGH
00Z THIS EVENING. HIGHS WILL PRIMARILY DEPEND ON THE TIMING AND
COVERAGE OF MID/UPPER LEVEL CLOUD COVER SLOWLY PROGRESSING INTO THE
AREA FROM THE WEST. WILL FCST HIGHS RANGING FROM THE MID/UPPER 60S
(W/NW PIEDMONT) TO UPPER 60S/LOWER 70S ELSEWHERE.
TONIGHT:
UNCERTAINTY INCREASES TONIGHT...PRIMARILY WITH THE PRECIPITATION
FORECAST. FORCING FOR ASCENT OVER CENTRAL NC OVERNIGHT WILL
GENERALLY BE LIMITED TO WEAK/BROAD MID-LEVEL HEIGHT FALLS AND
LOW-LEVEL WARM ADVECTION. W/REGARD TO THERMODYNAMICS...WEAK
MID-LEVEL LAPSE RATES AND BAD DIURNAL TIMING WILL CONTRIBUTE TO VERY
LITTLE OR NO AVAILABLE INSTABILITY OVERNIGHT. THE ABOVE ALONE WOULD
ARGUE FOR VERY LITTLE OR NO CHANCE OF SHOWER ACTIVITY OVERNIGHT...
AND VIRTUALLY NO CHANCE OF THUNDER. HOWEVER...THE MID-LEVEL
VORTICITY MAXIMUM THAT DEVELOPED IN ASSOC/W DEEP CONVECTION UPSTREAM
OF THE AREA THIS MORNING IS PROGGED TO APPROACH THE WEST/SW PIEDMONT
BY ~00Z...PROGRESSING THROUGH CENTRAL NC OVERNIGHT. DESPITE POOR
THERMODYNAMICS AND WEAK BACKGROUND/SYNOPTIC ASCENT...DPVA ASSOC/W
THIS FEATURE WILL PROVIDE ADDITIONAL/FOCUSED FORCING...AND ISOLD/SCT
SHOWER ACTIVITY WILL CERTAINLY BE POSSIBLE. THE LATEST 12Z WRF-NMM
SIMULATED REFLECTIVITY PRODUCT IS MORE ROBUST THAN THE 00Z RUN IN
SHOWING SHOWER ACTIVITY DEVELOPING OVERNIGHT IN ASSOC/W THIS FEATURE.
ADDITIONALLY...THE SHORTWAVE CURRENTLY IN OKLAHOMA WILL APPROACH THE
SOUTHERN APPALACHIANS BY ~12Z TUE...AND SOME WEAK AMPLIFICATION WILL
BE POSSIBLE AS ADDITIONAL UPPER LEVEL ENERGY PROGRESSES FROM THE
DESERT SOUTHWEST INTO THE TN VALLEY. THIS COULD PROVIDE ADDITIONAL
FORCING FOR ASCENT FROM THE WEST CLOSE TO SUNRISE TUE MORNING...
ALTHOUGH THE LATEST GUIDANCE CONTINUES TO SUGGEST THE BEST FORCING
ASSOC/W THE SECOND WAVE WILL MOST LIKELY OCCUR AFTER SUNRISE...
DURING THE DAY TUE. WITH THE ABOVE IN MIND...FEEL THAT A SMALL
INCREASE IN PRECIP CHANCES IS WARRANTED OVERNIGHT...AND WILL
INDICATE A 30% CHANCE OF SHOWERS EVERYWHERE. DESPITE THE PRESENCE OF
AN UPPER LEVEL DISTURBANCE...GIVEN POOR DIURNAL TIMING AND WEAK/
INCREASINGLY MOIST ADIABATIC LAPSE RATES...LITTLE IF ANY INSTABILITY
IS EXPECTED...AND WILL LEAVE OUT MENTION OF THUNDER. WITH MOSTLY
CLOUDY OR OVERCAST SKIES...EXPECT LOWS MUCH WARMER THAN IN RECENT
DAYS...IN THE LOWER/MID 50S. -VINCENT
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM MONDAY...
OVERNIGHT SHOWERS SHOULD BE MOVING INTO THE NORTHERN COASTAL PLAIN
BY AROUND 12Z TUESDAY MORNING AS THE FIRST ROUND OF FORCING
ASSOCIATED WITH A SHORTWAVE CROSSING THE GREAT LAKES MOVES OFF THE
MID ATLANTIC COAST. WESTERLY MID LEVEL FLOW BRING DRIER MID LEVEL
AIR ACROSS THE CWA DURING THE DAY...WITH A WEAK LEE TROUGH
DEVELOPING OVER THE WESTERN PIEDMONT/FOOTHILLS. A SECOND...LOW
AMPLITUDE UPPER TROUGH/DISTURBANCE IS THEN FORECAST TO CROSS THE
AREA BETWEEN 15 AND 21Z. BECAUSE THE ORIGINAL COLD FRONT WILL
ESSENTIALLY WASH OUT AS IT CROSS THE MOUNTAINS...LOW LEVEL MOISTURE
WILL CHANGE VERY LITTLE DURING THE DAY TUESDAY. STRONG HEATING
WILL ALLOW TEMPS TO RISE INTO THE LOW TO MID 70S WITH DEWPOINTS
HOLDING IN THE MID 50S. THIS DAYTIME HEATING COMBINED WITH SLIGHTLY
STEEPER MID LEVEL LAPSE RATES SHOULD LEAD TO ANOTHER ROUND OF
ISOLATED SHOWERS...FOCUSED MAINLY NEAR THE LEE TROUGH AND AIDED BY
THE AFOREMENTIONED WEAK UPPER TROUGH PASSAGE. THE MUCH DRIER MID
LEVEL AIR WILL LIMIT COVERAGE...BUT 400-800 J/KG MAY SUPPORT A FEW
ISOLATED THUNDERSTORMS OVER THE WESTERN PIEDMONT. WEAK DEEP LAYER
SHEAR AND THIN CAPE PROFILES SHOULD PRECLUDE ANY SEVERE STORMS...BUT
DOWNDRAFT CAPE COULD CLIMB INTO THE 500-1000 J/KG RANGE AND SUPPORT
SOME ENHANCED WIND GUSTS. BASED ON THE LIMITED COVERAGE
EXPECTED...WE WILL CONTINUE THE SLIGHT CHANCE POP ADVERTISED.
ANOTHER MILD NIGHT EXPECTED TUESDAY NIGHT AS SHOWERS COME TO AN END
BUT LOW LEVEL MOISTURE REMAINS IN PLACE. SOME FOG MAY BE POSSIBLE
IN THE EAST AS WINDS BECOME LIGHT. LOWS IN THE LOW TO MID 50S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 235 AM MONDAY...
FOR WEDNESDAY/WEDNESDAY NIGHT: WHAT IS LEFT OF THE WEAK SURFACE
TROUGH WILL SETTLE OVER THE SOUTHEAST CWA WEDNESDAY MORNING.
LINGERING HIGHER SURFACE DEW POINTS ALONG AND SOUTHEAST OF THIS
FRONTAL ZONE ALONG WITH LIMITED MIXING SHOULD YIELD PATCHY STRATUS
ACROSS THE EASTERN/SOUTHERN CWA EARLY WEDNESDAY MORNING... SLOWLY
MIXING OUT AND DISSIPATING BY LATE MORNING DUE TO THE DRY AIR ABOVE
850 MB. THE MID LEVEL LOW WILL MOVE SLOWLY FROM SOUTHERN QUEBEC
ACROSS MAINE AND OFF ITS COAST BY WEDNESDAY NIGHT... ALLOWING FOR
JUST A SUBTLE RISE IN MID LEVEL THICKNESSES OVER NC. DESPITE THE
LACK OF STRONG SUBSIDENCE ALOFT HOWEVER... THE MID AND UPPER LEVELS
WILL BE QUITE DRY AND THUS EXPECT PLENTY OF SUNSHINE WITH ONLY
SCATTERED FLAT STRATOCUMULUS FROM LATE MORNING ONWARD. THEN AFTER
NIGHTFALL... SURFACE WINDS WILL REMAIN VERY LIGHT WITH A LINGERING
WEAK SURFACE BOUNDARY EVIDENT OVER THE SOUTHEAST CWA. THE GFS
RETAINS GREATER LOW LEVEL MOISTURE THAN THE NAM WITH HIGHER 850 MB
THETA-E... WHICH RESULTS IN THE GFS BRINGING BROKEN MID CLOUDS OVER
THE WESTERN AND NORTHERN CWA WEDNESDAY NIGHT. THIS IS CERTAINLY
POSSIBLE GIVEN THE WEAK BUT STILL DISTINCT 850 MB WARM FRONTAL ZONE
OVER VA/NE NC AND THE POTENTIAL FOR CONVECTION UPSTREAM OVER THE MID
MISS VALLEY INTO THE OHIO VALLEY. WILL BRING IN AT LEAST SCATTERED
CLOUDS WEDNESDAY NIGHT NORTH. MODEL-PREDICTED THICKNESSES WILL BE
40+ METERS ABOVE SEASONAL NORMALS... SUPPORTING WARM FORECAST HIGHS
OF 76-80. LOWS 50-54 UNDER MOSTLY CLEAR TO PARTLY CLOUDY SKIES.
FOR THURSDAY/THURSDAY NIGHT: THE VERY WEAK SURFACE HIGH CENTERED TO
OUR NORTH WEDNESDAY NIGHT SHIFTS EASTWARD AND OFFSHORE THURSDAY...
AND THE ENSUING SOUTHEASTERLY/SOUTHERLY RETURN FLOW WILL BRING
INCREASING AMOUNTS OF LOW LEVEL MOISTURE INTO CENTRAL NC. BUT THE
GFS/ECMWF BRING THE MID LEVEL RIDGE AXIS OVERHEAD THURSDAY THROUGH
THURSDAY NIGHT WITH ENOUGH DRY AIR ALOFT TO KEEP THE FORECAST DRY...
ALBEIT WITH SCATTERED TO BRIEFLY BROKEN FLAT CUMULUS IN THE
AFTERNOON. HIGHS IN THE UPPER 70S AND LOWS IN THE LOWER-MID 50S.
FOR FRIDAY THROUGH SUNDAY: CONTINUED VERY WARM... BUT THE CHANCES
FOR AFTERNOON/EVENING CONVECTION WILL INCREASE A BIT. THE MID LEVEL
RIDGE AXIS DROPS JUST TO OUR SOUTHEAST FRIDAY AND MODELS DEPICT
MINOR DISTURBANCES TRACKING TOWARD AND INTO THE REGION WITHIN THE
FLATTENING WSW FLOW ALOFT. GFS/ECMWF SHOW ONE SUCH WEAK PERTURBATION
APPROACHING THE SOUTHERN APPALACHIANS AND INSTIGATING CONVECTION
FRIDAY AFTERNOON OVER THE MOUNTAINS/FOOTHILLS AND WRN PIEDMONT...
ALONG A SOUTH-SOUTHWESTERLY 20-25 KT 850 MB JET AND A WEAK LEE
SURFACE TROUGH JUST EAST OF THE MOUNTAINS. GIVEN THE SHIFT IN 700 MB
WINDS FROM DRY NORTHWESTERLY TO MOIST SOUTHWESTERLY AS THE RIDGE
AXIS PIVOTS ESE THROUGH CENTRAL NC... WILL RETAIN A CHANCE OF
SHOWERS AND PERHAPS A STORM OR TWO FRIDAY AFTERNOON INTO THE NIGHT
OVER THE NORTHERN AND WESTERN CWA. DEEP MID LEVEL LONGWAVE TROUGHING
CONTINUES TO DIG OVER THE WEST COAST AND ROCKIES OVER THE WEEKEND...
KEEPING A PREVAILING MEAN RIDGE OVER THE GULF AND SOUTHEAST STATES
THROUGH SUNDAY. LOW LEVEL MOISTURE WILL INCREASE STEADILY OVER NC
WITH THE PERSISTENT CARIBBEAN-SOURCE SE/S FLOW... WHILE THE EASTWARD
SHIFT OF THE 700 MB ANTICYCLONE CENTER WILL ALLOW WEST GULF MOISTURE
RIDING AROUND THE RIDGE TO WORK INTO NC FROM THE WSW. SINCE THE
RIDGE ALOFT WILL NOT BE PARTICULARLY STRONG AND WITH STRONG
SUBSIDENCE LACKING... THE SCENARIO OF INCREASING DIURNAL CONVECTION
IS REASONABLE... PARTICULARLY CONSIDERING THE RISING PRECIPITABLE
WATER TO 200-250% OF NORMAL. WILL HAVE CHANCE POPS SATURDAY THROUGH
SUNDAY... MAINLY IN THE AFTERNOON AND EVENING. WEAK STEERING WILL
SUPPORT SLOW-MOVING CELLS WITH ANY SHOWERS OR STORMS WHICH DEVELOP.
THICKNESSES HOLD WELL ABOVE NORMAL... SUPPORTING HIGHS IN THE MID
70S TO NEAR 80 AND LOWS MOSTLY IN THE MID 50S. -GIH
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 215 PM MONDAY...
24-HR TAF PERIOD:
VFR CONDITIONS ARE EXPECTED TO PREDOMINATE THROUGH 00Z THIS
EVENING...WITH SUB-VFR CONDITIONS POSSIBLE OVERNIGHT INTO TUESDAY.
VFR CEILINGS BETWEEN 3000-5000 FT WERE OBSERVED OVER MOST OF CENTRAL
NC AS OF 18Z THIS AFTERNOON. EXPECT CEILINGS TO REMAIN VFR OR
BORDERLINE MVFR AT BEST THROUGH 00Z THIS EVENING. TONIGHT...AN UPPER
LEVEL DISTURBANCE APPROACHING THE AREA FROM THE SOUTHWEST MAY HELP
ISOLD/SCT SHOWER ACTIVITY DEVELOP ACROSS THE AREA...THOUGH ENOUGH
UNCERTAINTY REMAINS TO PRECLUDE MENTION OF SHOWERS IN THE 18Z TAF
ISSUANCE. ADDITIONALLY...SOUTHWESTERLY RETURN FLOW AND WARM
ADVECTION IN THE LOWER LEVELS COULD RESULT IN THE DEVELOPMENT OF
MVFR/IFR CEILINGS ACROSS PORTIONS OF THE AREA OVERNIGHT. ALTHOUGH
SUB-VFR CONDITIONS WILL BE POSSIBLE EVERYWHERE...AT THIS TIME THE
BEST CHANCE THROUGH 12Z TUE APPEARS TO BE AT THE INT/GSO/RDU TAF
SITES. AFTER SUNRISE TUESDAY...THE FAY/RWI TAF SITES WILL HAVE THE
RELATIVE BEST CHANCE OF ISOLD/SCT SHOWER ACTIVITY AND SUB-VFR
CEILINGS. AN ISOLD THUNDERSTORM CANNOT BE RULED OUT AT FAY/RWI NEAR
OR PRIOR TO 18Z TUE. WINDS WILL BE SOUTHWEST AT ~10 KT THIS
AFTERNOON...WEAKENING TO ~5 KT OVERNIGHT...INCREASING TO ~10 KT
AGAIN ON TUE.
LOOKING AHEAD:
SUB-VFR CEILINGS OR FOG WILL BE POSSIBLE TUE NIGHT GIVEN MID/UPPER
LEVEL DRYING (CLEARING SKIES) IN THE PRESENCE OF A MOIST BOUNDARY
LAYER AND LIGHT/CALM WINDS. EXPECT VFR CONDITIONS TO PREVAIL WED
THROUGH THU IN ASSOC/W HIGH PRESSURE AND A RELATIVELY DRIER AIRMASS
IN PLACE. AFTER A BRIEF POTENTIAL FOR FOG FRIDAY MORNING...SHOWERS
AND STORMS WILL BE POSSIBLE FRI/FRI NIGHT AND POSSIBLY INTO SAT IN
ASSOC/W AN UPPER LEVEL DISTURBANCE AND SURFACE TROUGH PROGGED TO
PROGRESS THROUGH THE AREA. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH
LONG TERM...HARTFIELD
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1216 PM EDT MON MAR 12 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED OFFSHORE WILL CONTINUE TO EXTEND WESTWARD
INTO THE CAROLINAS THROUGH TONIGHT. A WEAK SURFACE TROUGH AND UPPER
LEVEL DISTURBANCE WILL PROGRESS INTO THE AREA FROM THE WEST ON
TUESDAY. A GENERAL WARMING TREND IS EXPECTED THROUGH MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1215 PM MONDAY...
TODAY:
THE PROGRESSIVE UPPER LOW CURRENTLY IN THE NORTHERN MS RIVER VALLEY
WILL TRACK NORTHEAST INTO ONTARIO TODAY...WHILE ADDITIONAL SHORTWAVE
ENERGY CURRENTLY OVER SASKATCHEWAN/MONTANA PROGRESSES EAST TOWARD
MANITOBA. HEIGHT FALLS (ASSOC/W THE AFOREMENTIONED UPPER LOW) OVER
THE OH VALLEY/MID-ATLANTIC WILL PUSH THE H5 RIDGE OFFSHORE
TODAY...WITH INCREASINGLY WESTERLY FLOW ALOFT OVER CENTRAL NC. A
MINOR SHORTWAVE WAS PRESENT UPSTREAM OVER OKLAHOMA AT 15Z...AND IS
PROGGED TO PROGRESS EAST INTO THE WESTERN TN VALLEY BY 00Z THIS
EVENING. THE LATEST RUC MODEL DATA SHOWED A MID-LEVEL VORTICITY
MAXIMUM OVER THE DEEP SOUTH AT 15Z...APPARENTLY EMANATING FROM DEEP
CONVECTION/STRONG MID-LEVEL LATENT HEATING PRESENT OVER THE LA/MS
GULF COAST THIS MORNING...AND THE RUC SHOWS THIS FEATURE PROGRESSING
NORTHEAST INTO GA/UPSTATE SC/WESTERN NC BY 00Z THIS EVENING. IN THE
LOWER LEVELS...A 5-10 KT SOUTHERLY RETURN FLOW WILL PREVAIL OVER THE
AREA...ON THE WESTERN PERIPHERY OF THE LOW-LEVEL RIDGE AXIS NOW
CENTERED OFFSHORE THE CAROLINA COAST. W/REGARD TO PRECIP CHANCES...
LITTLE OR NO FORCING FOR ASCENT WILL BE PRESENT THIS AFTERNOON...
ASIDE FROM VERY WEAK/BROAD WARM ADVECTION ASSOC/W SOUTHERLY RETURN
FLOW. INCREASING MID/UPPER LEVEL CLOUD COVER (LIMITING INSOLATION IN
THE WEST) AND A LINGERING MID-LEVEL SUBSIDENCE INVERSION (ASSOC/W
THE DEPARTING H5 RIDGE AXIS IN THE EAST) SHOULD SIGNIFICANTLY HAMPER
ANY DIURNAL DESTABILIZATION THIS AFTERNOON...WITH VERY LITTLE OR NO
AVAILABLE INSTABILITY. AS A RESULT...EXPECT A DRY FORECAST THROUGH
00Z THIS EVENING. HIGHS WILL PRIMARILY DEPEND ON THE TIMING AND
COVERAGE OF MID/UPPER LEVEL CLOUD COVER SLOWLY PROGRESSING INTO THE
AREA FROM THE WEST. WILL FCST HIGHS RANGING FROM THE MID/UPPER 60S
(W/NW PIEDMONT) TO UPPER 60S/LOWER 70S ELSEWHERE.
TONIGHT:
UNCERTAINTY IN THE FORECAST INCREASES TONIGHT...PRIMARILY WITH THE
PRECIPITATION FORECAST. FORCING FOR ASCENT OVER CENTRAL NC OVERNIGHT
WILL PRIMARILY BE LIMITED TO WEAK/BROAD MID-LEVEL HEIGHT FALLS AND
LOW-LEVEL WARM ADVECTION. W/REGARD TO THERMODYNAMICS...WEAK
MID-LEVEL LAPSE RATES AND BAD DIURNAL TIMING WILL CONTRIBUTE TO VERY
LITTLE OR NO AVAILABLE INSTABILITY OVERNIGHT. THE ABOVE ALONE WOULD
ARGUE FOR VERY LITTLE OR NO CHANCE OF SHOWER ACTIVITY OVERNIGHT...
AND VIRTUALLY NO CHANCE OF THUNDER. HOWEVER...THE MID-LEVEL
VORTICITY MAXIMUM THAT DEVELOPED IN ASSOC/W DEEP CONVECTION UPSTREAM
OF THE AREA THIS MORNING IS PROGGED TO APPROACH THE WEST/SW PIEDMONT
BY ~00Z...PROGRESSING THROUGH CENTRAL NC BETWEEN 00-06Z. DESPITE
POOR THERMODYNAMICS AND WEAK BACKGROUND/ SYNOPTIC ASCENT...DPVA
ASSOC/W THIS FEATURE WILL PROVIDE ADDITIONAL FORCING BETWEEN ROUGHLY
SUNSET AND MIDNIGHT...AND ISOLD SHOWER ACTIVITY WILL AT LEAST BE
POSSIBLE...THOUGH THE 00Z WRF-NMM SIMULATED REFLECTIVITY PRODUCT
SHOWS NO PRECIP OVER CENTRAL NC IN THAT TIME FRAME. ADDITIONALLY...
BY THE TIME THE SHORTWAVE CURRENTLY IN OKLAHOMA APPROACHES THE
SOUTHERN APPALACHIANS (~12Z TUE)...SOME WEAK AMPLIFICATION WILL BE
POSSIBLE AS ADDITIONAL UPPER LEVEL ENERGY PROGRESSES FROM THE DESERT
SOUTHWEST INTO THE TN VALLEY. THIS COULD PROVIDE ADDITIONAL FORCING
FOR ASCENT FROM THE WEST CLOSE TO SUNRISE TUE MORNING...ALTHOUGH THE
LATEST GUIDANCE SUGGESTS THE BEST FORCING ASSOC/W THE AFOREMENTIONED
FEATURE WILL MOST LIKELY OCCUR AFTER SUNRISE...DURING THE DAY TUE.
THE 00Z WRF-NMM KEEPS CENTRAL NC DRY THROUGH 09Z...THEN SHOWS
ISOLD/SCT SHOWER ACTIVITY DEVELOPING OVER THE NORTHWESTERN HALF OF
THE AREA RIGHT AROUND 12Z. WITH THE ABOVE IN MIND...WILL INDICATE A
SLIGHT TO LOW CHANCE (20-30%) OF SHOWERS OVER MOST OF THE AREA
BETWEEN 00-06Z...HIGHEST (30%) IN THE SW PIEDMONT...AND WILL KEEP A
SLIGHT CHANCE OF SHOWERS OVER THE ENTIRE AREA THROUGH THE REMAINDER
OF THE NIGHT...RELATIVE BEST CHANCE NEAR OR WEST OF HWY 1 BETWEEN
09-12Z. WILL LEAVE OUT MENTION OF THUNDER AS MENTIONED ABOVE. WITH
MOSTLY CLOUDY OR OVERCAST SKIES...EXPECT LOWS MUCH WARMER THAN IN
RECENT DAYS...IN THE LOWER/MID 50S. -VINCENT
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM MONDAY...
OVERNIGHT SHOWERS SHOULD BE MOVING INTO THE NORTHERN COASTAL PLAIN
BY AROUND 12Z TUESDAY MORNING AS THE FIRST ROUND OF FORCING
ASSOCIATED WITH A SHORTWAVE CROSSING THE GREAT LAKES MOVES OFF THE
MID ATLANTIC COAST. WESTERLY MID LEVEL FLOW BRING DRIER MID LEVEL
AIR ACROSS THE CWA DURING THE DAY...WITH A WEAK LEE TROUGH
DEVELOPING OVER THE WESTERN PIEDMONT/FOOTHILLS. A SECOND...LOW
AMPLITUDE UPPER TROUGH/DISTURBANCE IS THEN FORECAST TO CROSS THE
AREA BETWEEN 15 AND 21Z. BECAUSE THE ORIGINAL COLD FRONT WILL
ESSENTIALLY WASH OUT AS IT CROSS THE MOUNTAINS...LOW LEVEL MOISTURE
WILL CHANGE VERY LITTLE DURING THE DAY TUESDAY. STRONG HEATING
WILL ALLOW TEMPS TO RISE INTO THE LOW TO MID 70S WITH DEWPOINTS
HOLDING IN THE MID 50S. THIS DAYTIME HEATING COMBINED WITH SLIGHTLY
STEEPER MID LEVEL LAPSE RATES SHOULD LEAD TO ANOTHER ROUND OF
ISOLATED SHOWERS...FOCUSED MAINLY NEAR THE LEE TROUGH AND AIDED BY
THE AFOREMENTIONED WEAK UPPER TROUGH PASSAGE. THE MUCH DRIER MID
LEVEL AIR WILL LIMIT COVERAGE...BUT 400-800 J/KG MAY SUPPORT A FEW
ISOLATED THUNDERSTORMS OVER THE WESTERN PIEDMONT. WEAK DEEP LAYER
SHEAR AND THIN CAPE PROFILES SHOULD PRECLUDE ANY SEVERE STORMS...BUT
DOWNDRAFT CAPE COULD CLIMB INTO THE 500-1000 J/KG RANGE AND SUPPORT
SOME ENHANCED WIND GUSTS. BASED ON THE LIMITED COVERAGE
EXPECTED...WE WILL CONTINUE THE SLIGHT CHANCE POP ADVERTISED.
ANOTHER MILD NIGHT EXPECTED TUESDAY NIGHT AS SHOWERS COME TO AN END
BUT LOW LEVEL MOISTURE REMAINS IN PLACE. SOME FOG MAY BE POSSIBLE
IN THE EAST AS WINDS BECOME LIGHT. LOWS IN THE LOW TO MID 50S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 235 AM MONDAY...
FOR WEDNESDAY/WEDNESDAY NIGHT: WHAT IS LEFT OF THE WEAK SURFACE
TROUGH WILL SETTLE OVER THE SOUTHEAST CWA WEDNESDAY MORNING.
LINGERING HIGHER SURFACE DEW POINTS ALONG AND SOUTHEAST OF THIS
FRONTAL ZONE ALONG WITH LIMITED MIXING SHOULD YIELD PATCHY STRATUS
ACROSS THE EASTERN/SOUTHERN CWA EARLY WEDNESDAY MORNING... SLOWLY
MIXING OUT AND DISSIPATING BY LATE MORNING DUE TO THE DRY AIR ABOVE
850 MB. THE MID LEVEL LOW WILL MOVE SLOWLY FROM SOUTHERN QUEBEC
ACROSS MAINE AND OFF ITS COAST BY WEDNESDAY NIGHT... ALLOWING FOR
JUST A SUBTLE RISE IN MID LEVEL THICKNESSES OVER NC. DESPITE THE
LACK OF STRONG SUBSIDENCE ALOFT HOWEVER... THE MID AND UPPER LEVELS
WILL BE QUITE DRY AND THUS EXPECT PLENTY OF SUNSHINE WITH ONLY
SCATTERED FLAT STRATOCUMULUS FROM LATE MORNING ONWARD. THEN AFTER
NIGHTFALL... SURFACE WINDS WILL REMAIN VERY LIGHT WITH A LINGERING
WEAK SURFACE BOUNDARY EVIDENT OVER THE SOUTHEAST CWA. THE GFS
RETAINS GREATER LOW LEVEL MOISTURE THAN THE NAM WITH HIGHER 850 MB
THETA-E... WHICH RESULTS IN THE GFS BRINGING BROKEN MID CLOUDS OVER
THE WESTERN AND NORTHERN CWA WEDNESDAY NIGHT. THIS IS CERTAINLY
POSSIBLE GIVEN THE WEAK BUT STILL DISTINCT 850 MB WARM FRONTAL ZONE
OVER VA/NE NC AND THE POTENTIAL FOR CONVECTION UPSTREAM OVER THE MID
MISS VALLEY INTO THE OHIO VALLEY. WILL BRING IN AT LEAST SCATTERED
CLOUDS WEDNESDAY NIGHT NORTH. MODEL-PREDICTED THICKNESSES WILL BE
40+ METERS ABOVE SEASONAL NORMALS... SUPPORTING WARM FORECAST HIGHS
OF 76-80. LOWS 50-54 UNDER MOSTLY CLEAR TO PARTLY CLOUDY SKIES.
FOR THURSDAY/THURSDAY NIGHT: THE VERY WEAK SURFACE HIGH CENTERED TO
OUR NORTH WEDNESDAY NIGHT SHIFTS EASTWARD AND OFFSHORE THURSDAY...
AND THE ENSUING SOUTHEASTERLY/SOUTHERLY RETURN FLOW WILL BRING
INCREASING AMOUNTS OF LOW LEVEL MOISTURE INTO CENTRAL NC. BUT THE
GFS/ECMWF BRING THE MID LEVEL RIDGE AXIS OVERHEAD THURSDAY THROUGH
THURSDAY NIGHT WITH ENOUGH DRY AIR ALOFT TO KEEP THE FORECAST DRY...
ALBEIT WITH SCATTERED TO BRIEFLY BROKEN FLAT CUMULUS IN THE
AFTERNOON. HIGHS IN THE UPPER 70S AND LOWS IN THE LOWER-MID 50S.
FOR FRIDAY THROUGH SUNDAY: CONTINUED VERY WARM... BUT THE CHANCES
FOR AFTERNOON/EVENING CONVECTION WILL INCREASE A BIT. THE MID LEVEL
RIDGE AXIS DROPS JUST TO OUR SOUTHEAST FRIDAY AND MODELS DEPICT
MINOR DISTURBANCES TRACKING TOWARD AND INTO THE REGION WITHIN THE
FLATTENING WSW FLOW ALOFT. GFS/ECMWF SHOW ONE SUCH WEAK PERTURBATION
APPROACHING THE SOUTHERN APPALACHIANS AND INSTIGATING CONVECTION
FRIDAY AFTERNOON OVER THE MOUNTAINS/FOOTHILLS AND WRN PIEDMONT...
ALONG A SOUTH-SOUTHWESTERLY 20-25 KT 850 MB JET AND A WEAK LEE
SURFACE TROUGH JUST EAST OF THE MOUNTAINS. GIVEN THE SHIFT IN 700 MB
WINDS FROM DRY NORTHWESTERLY TO MOIST SOUTHWESTERLY AS THE RIDGE
AXIS PIVOTS ESE THROUGH CENTRAL NC... WILL RETAIN A CHANCE OF
SHOWERS AND PERHAPS A STORM OR TWO FRIDAY AFTERNOON INTO THE NIGHT
OVER THE NORTHERN AND WESTERN CWA. DEEP MID LEVEL LONGWAVE TROUGHING
CONTINUES TO DIG OVER THE WEST COAST AND ROCKIES OVER THE WEEKEND...
KEEPING A PREVAILING MEAN RIDGE OVER THE GULF AND SOUTHEAST STATES
THROUGH SUNDAY. LOW LEVEL MOISTURE WILL INCREASE STEADILY OVER NC
WITH THE PERSISTENT CARIBBEAN-SOURCE SE/S FLOW... WHILE THE EASTWARD
SHIFT OF THE 700 MB ANTICYCLONE CENTER WILL ALLOW WEST GULF MOISTURE
RIDING AROUND THE RIDGE TO WORK INTO NC FROM THE WSW. SINCE THE
RIDGE ALOFT WILL NOT BE PARTICULARLY STRONG AND WITH STRONG
SUBSIDENCE LACKING... THE SCENARIO OF INCREASING DIURNAL CONVECTION
IS REASONABLE... PARTICULARLY CONSIDERING THE RISING PRECIPITABLE
WATER TO 200-250% OF NORMAL. WILL HAVE CHANCE POPS SATURDAY THROUGH
SUNDAY... MAINLY IN THE AFTERNOON AND EVENING. WEAK STEERING WILL
SUPPORT SLOW-MOVING CELLS WITH ANY SHOWERS OR STORMS WHICH DEVELOP.
THICKNESSES HOLD WELL ABOVE NORMAL... SUPPORTING HIGHS IN THE MID
70S TO NEAR 80 AND LOWS MOSTLY IN THE MID 50S. -GIH
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 720 AM MONDAY...
THERE IS SOME STRATUS OVER THE FOOTHILLS DRIFTING TOWARD
KINT/KGSO...AND ALSO SOME FOG OVER THE COASTAL PLAIN NEAR KFAY AND
KRWI THIS MORNING. HOWEVER... BASED ON SATELLITE AND FORECAST
SOUNDINGS IT DOES NOT APPEAR THAT EITHER SHOULD CAUSE MORE THAN A
BRIEF PERIOD OF MVFR CEILINGS OR VSBYS THROUGH 15Z. MIXING WILL THEN
ERODE THE FOG AND LIFT CEILINGS TO AT OR ABOVE 4K FT OVER THE
WESTERN PIEDMONT...LEADING TO VFR CONDITIONS WITH 5-10KT
SOUTHWESTERLY WINDS TODAY AND GUSTS TO 15-20KT AT TIMES.
DEEP LAYER MOISTURE WILL CONTINUE TO INCREASE THIS EVENING AS A COLD
FRONT APPROACHES THE MOUNTAINS FROM WEST. THE COLD FRONT IS
EXPECTED TO WEAKEN DRAMATICALLY AND MOST PRECIP ASSOCIATED WITH THE
FRONT SHOULD PASS ACROSS VA OVERNIGHT. CEILINGS ARE FORECAST TO
LOWER OVERNIGHT...WITH MVFR CONDITIONS EXPECTED TO DEVELOP AFTER
MIDNIGHT. THERE IS A SLIGHT CHANCE THAT KING/KGSO AND KRDU COULD
EXPERIENCE A SHOWER OVERNIGHT...WHICH COULD BRING CEILINGS AND VSBYS
DOWN TO MVFR OR LOWER SOONER THAN EXPECTED. THE LONE EXCEPTION IS
KFAY...WHICH MAY EXPERIENCE SOME LIMITED VSBYS AS STRATUS SHOULD
REMAIN MOSTLY NORTH OF THAT TERMINAL.
LOOKING AHEAD:
SHOWERS AND POSSIBLY AN ISOLATED THUNDERSTORM ASSOCIATED WITH A
WEAKENING COLD FRONT AND AN UPPER LEVEL DISTURBANCE WILL BE POSSIBLE
TUESDAY. THUS..SOME ADVERSE AVIATION CONDITIONS CAN BE EXPECTED
TUESDAY. FOG WILL BE POSSIBLE DURING THE PREDAWN HOURS (06-12Z)
THROUGHOUT MUCH OF THE WORK WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH
LONG TERM...HARTFIELD
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
303 PM CDT MON MAR 12 2012
...NEAR OR ABOVE RECORD HIGHS EXPECTED THROUGHOUT MUCH OF THE
FORECAST...
.SHORT TERM...TONIGHT THROUGH THURSDAY
303 PM CDT MON MAR 12 2012
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT
ANALYSIS SHOWED SOUTHWEST FLOW FROM THE PACIFIC NORTHWEST TO
HUDSON BAY... WITH A SHORTWAVE TROUGH OVER SASKATCHEWAN. IN THE
SOUTHERN STREAM...AN UPPER LOW WAS NEAR EAU CLAIRE WITH A
SHORTWAVE ROUNDING ITS BASE OVER NORTHERN ILLINOIS. THIS LATTER
SHORTWAVE IS HELPING TO SUSTAIN SHOWERS AND A FEW THUNDERSTORMS
OVER SOUTHEAST WISCONSIN AND NORTHERN ILLINOIS...AIDED BY DAYTIME
HEATING. OTHER SHOWER ACTIVITY WAS OVER NORTHERN AND CENTRAL
WISCONSIN...AIDED BY DPVA FORCING AHEAD OF THE UPPER LOW. ANOTHER
AREA OF SHOWERS WERE WEST OF MINNEAPOLIS IN THE DEFORMATION ON THE
BACK SIDE OF THE UPPER LOW. THERE HAS BEEN SOME PARTIAL CLEARING
TODAY SOUTH OF I-90...THANKS TO DRY AIR WRAPPING AROUND THE UPPER
LOW. THIS CLEARING COMBINED WITH A WARM LAST NIGHT HAS ALLOWED
TEMPERATURES TO CLIMB MOSTLY INTO THE 50S...DESPITE 850MB TEMPS
WHICH HAVE DROPPED TO 2-4C PER RUC ANALYSIS...AND THE 3C READING
AT OAX AT 12Z. MUCH WARMER AIR AT 850MB EXISTS OVER THE
DAKOTAS...THOUGH...WITH READINGS OF 12C AT BIS AND UNR AT 12Z.
TONIGHT AND TUESDAY...THE UPPER LOW OVER WESTERN WISCONSIN IS
PROGGED TO CONTINUE ITS NORTHEASTWARD TREK...LIFTING INTO NORTHEAST
ONTARIO BY 12Z TUESDAY. IT APPEARS THIS UPPER LOW WILL THEN SLOW
DOWN...DUE TO THE CURRENT SHORTWAVE TROUGH IN SASKATCHEWAN WHICH
MODELS HAVE IT PHASING WITH THE UPPER LOW. THE ONLY IMPACTS THIS
PHASING HAS ON OUR FORECAST AREA IS NORTH OF I-94 TUESDAY
MORNING...WHERE SLIGHTLY COOLER AND DRIER AIR WILL MOVE IN.
OTHERWISE...850MB TEMPS ARE PROGGED TO BE ON THE RISE THROUGHOUT
THIS TIME PERIOD. AT 12Z TUESDAY...THEY SHOULD RANGE FROM
4-8C...THEN RISE TO 8-12C BY 00Z WEDNESDAY. THIS WARMING COMBINED
WITH CLEARING SKIES AND DRIER AIR FOR TUESDAY SHOULD RESULT IN
DECENT MIXING. STAYED TOWARD THE HIGH END OF GUIDANCE FOR HIGHS
WHICH PUTS THEM CLOSE TO OR ABOVE RECORD VALUES. REGARDING TONIGHTS
LOWS...PRECIPITABLE WATER VALUES ARE FORECAST TO DROP TO 0.25 INCH
BY 12Z OR LOWER AFTER BEING UP BETWEEN 0.5-0.75 INCHES. THIS DRY AIR
SHOULD HELP TEMPERATURES DROP...THOUGH WINDS KIND OF STAY UP THROUGH
MUCH OF THE NIGHT UNTIL LATE. THEREFORE HAVE TAKEN A BLEND OF
GUIDANCE APPROACH. COULD HAVE SOME PATCHY FOG WHERE WINDS CAN
DECOUPLE DUE TO RECENT RAINS...WHILE THE OVERALL WIND ESPECIALLY
RIGHT ABOVE THE SURFACE KEEPS THE FOG FROM BECOMING MORE WIDESPREAD.
TUESDAY NIGHT THROUGH THURSDAY...A BIG CHUNK OF THE UPPER TROUGHING
CURRENTLY OFF THE PACIFIC NORTHWEST COAST IS FORECAST TO LIFT OUT
INTO SOUTHWEST CANADA TUESDAY NIGHT...THEN UP TO HUDSON BAY BY
WEDNESDAY NIGHT. A STRONG LOW PRESSURE SYSTEM DEVELOPS FROM THIS
UPPER TROUGHING...THOUGH AGAIN WELL OFF TO OUR NORTH. HOWEVER...
THERE ARE GOING TO BE SOME IMPACTS FROM IT. FIRST...A SURGE OF WARM
AIR CAUSED BY DOWNSLOPING OFF THE ROCKIES WILL MOVE INTO THE AREA.
THE FIRST FEELING OF THIS COMES TUESDAY NIGHT AS INCREASING
SOUTHEAST TO SOUTH WINDS BRING HIGHER DEWPOINTS AND 850MB TEMPS RISE
TO 12-14C. THIS SITUATION MAY KEEP TEMPERATURES FROM FALLING BELOW
50 ALONG AND WEST OF THE MISSISSIPPI RIVER. ON WEDNESDAY...WINDS
TURN SOUTHWEST AHEAD OF THE LOW PRESSURE SYSTEMS COLD FRONT
CROSSING MINNESOTA. THERE ARE INDICATIONS FROM THE 12.12Z NAM/ECMWF
THAT 850MB TEMPS COULD EVEN RISE TO 16C OVER NORTHEAST IOWA...ALMOST
3 STANDARD DEVIATIONS ABOVE NORMAL. WITH PLENTY OF SUN AND A WARM
START...TEMPERATURES SHOULD EASILY CLIMB INTO THE 70S. AN 80F
READING MAY EVEN OCCUR (NOTE 81F HIGH FOR SPARTA OFF MET GUIDANCE).
DEWPOINTS ARE ALSO EXPECTED TO CLIMB INTO THE 50S WITH A GOOD FETCH
COMING OUT OF THE GULF OF MEXICO. THE COMBINATION OF THE
UNPRECEDENTED WARMTH AND DEWPOINTS WILL LIKELY LEAD TO CUMULUS
DEVELOPMENT...MAKING IT FEEL MORE LIKE LATE SPRING THAN MID MARCH.
FOR WEDNESDAY NIGHT INTO THURSDAY...THE UPPER FLOW TURNS A LITTLE
MORE TOWARDS WEST...ENOUGH TO ALLOW THE WEAKENING COLD FRONT TO MOVE
INTO THE FORECAST AREA. BELIEVE THE 12.12Z NAM IS TOO AGGRESSIVE ON
THE SPEED GIVEN THE 12.12Z GFS/UKMET/ECMWF SLOWER. IN ANY EVENT...
THE FRONT WILL RE-ORIENT ITSELF WEST-EAST...LIKELY OCCURRING ON
THURSDAY NEAR OR JUST SOUTH OF I-90. CONVECTIVE INITIATION ON THE
FRONT DOES NOT SEEM LIKELY...DUE TO CAPPING. THE 12.12Z GFS DOES TRY
TO SPIT OUT THESE VERY LIGHT QPF VALUES...BUT THIS IS MORE FROM THE
MODEL BRINGING IN TOO MUCH LOW LEVEL MOISTURE AND GENERATING
STRATUS/DRIZZLE VERSUS CONVECTION. EVEN THEN...THE PATTERN DOES NOT
FAVOR STRATUS/DRIZZLE AND THE MODEL SEEMS TO HAVE A HIGH MOISTURE
BIAS. EVEN WITH THE FRONTAL PASSAGE...850MB TEMPS ONLY DROP TO
10-12C SO THURSDAY MAY ONLY END UP A LITTLE COOLER THAN WEDNESDAY.
WEDNESDAY NIGHT ALSO LIKELY STAYING MILD...ESPECIALLY AHEAD OF THE
FRONT.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
303 PM CDT MON MAR 12 2012
MAIN STORY REMAINS THE UNPRECEDENTED WARMTH WHICH LOOKS TO PERSIST
THROUGH THE ENTIRE LONG TERM PERIOD AND BEYOND.
VERY GOOD MODEL AGREEMENT EXISTS THAT A DEEP UPPER LEVEL TROUGH IS
GOING TO DEVELOP ALONG THE WEST COAST OF THE U.S. FRIDAY INTO
SATURDAY. AS A RESULT...RIDGING BUILDS DOWNSTREAM OVER THE CENTRAL
AND EASTERN U.S.. THIS RIDGE BECOMES QUITE STRONG AND ACCORDING TO
THE CFS V2 MODEL...IT MAY PERSIST RIGHT THROUGH THE END OF THE
MONTH...WHILE THE WEST COAST TROUGH STAYS PUT OR CUTS-OFF. SINCE THE
CFS HAS BEEN DOING VERY WELL OVER THE PAST FEW MONTHS...HAVE
PREFERRED MODEL SCENARIOS WHICH KEEP THE WESTERN TROUGH IN
PLACE...WHICH LUCKILY MOST MODELS DO INCLUDING THE NEW 12.12Z ECMWF.
FOLLOWING THIS IDEA...850MB TEMPS THROUGHOUT THE LONG TERM PERIOD
STAY BETWEEN 10-14C OR 2-2.5 STANDARD DEVIATIONS ABOVE NORMAL. THIS
WOULD MEAN HIGHS NEAR OR ABOVE RECORD HIGHS. HAVE ADJUSTED ALL HIGH
TEMPERATURES TOWARDS THE HIGH END OF GUIDANCE. A PERSISTENT SOUTH
WIND OF 20-40 KT AT 925MB WILL HELP TO KEEP A PULL OF MOISTURE OUT
OF THE GULF OF MEXICO...THOUGH LACK OF VEGETATION AND THE DISTANCE
FROM THE GULF SHOULD HOLD DEWPOINTS BELOW 60. WITH THE WARM
TEMPERATURES AND DEWPOINTS...ANTICIPATING A LOT OF PARTLY SUNNY DAYS
DUE TO CUMULUS DEVELOPMENT.
PRECIPITATION CHANCES ARE VERY UNCERTAIN AND IT IS ENTIRELY POSSIBLE
THAT THE WHOLE LONG TERM PERIOD ENDS UP DRY. HOWEVER...WITH THE WELL
ABOVE NORMAL DEWPOINTS INTERACTING WITH WEAK SHORTWAVES COMING OUT
OF THE PACIFIC THROUGH THE BUILDING RIDGING...CANNOT RULE OUT A FEW
PERIODS OF SHOWERS AND THUNDERSTORMS. HAVE 20-30 PERCENT CHANCES
THROUGHOUT MUCH OF THE LONG TERM AS A RESULT. MUST BE STRESSED THAT
MUCH OF THIS PERIOD WILL LIKELY BE DRY.
&&
.AVIATION...THROUGH 18Z TUESDAY
1232 PM CDT MON MAR 12 2012
17Z WATER VAPOR IMAGERY SHOWS MID LEVEL LOW NOW OVER WEST CENTRAL
WISCONSIN. THIS LOW WILL CONTINUE TO LIFT NORTHEAST AWAY FROM THE
AREA. CEILINGS HAVE BEEN UNDULATING BETWEEN MVFR AND VFR SINCE
LATE MORNING...AS VISIBLE SATELLITE IMAGERY SHOWS SOME HOLES IN
THE CLOUDS. EXPECT THIS TREND TO CONTINUE THIS AFTERNOON AND WITH
SOME WEAK INSTABILITY WILL LIKELY SEE SOME SCATTERED SHOWERS THAT
MAY AFFECT THE TAF SITES FROM TIME TO TIME THROUGH 21Z. SURFACE
RIDGE MOVES IN FROM THE WEST TONIGHT. MODEL CONSENSUS IS FOR CLOUDS
TO CLEAR OUT BETWEEN 03Z-05Z WITH SKC AFTER THAT. WITH RIDGE AXIS
PUSHING INTO SOUTHEAST MINNESOTA LATE TONIGHT...QUESTION WILL BE
FOG POTENTIAL. BOTH THE 14.00Z NAM AND 14.15Z RUC BUFKIT SOUNDINGS
SHOWING WINDS AT THE SURFACE AROUND 5 TO 7 KNOTS...AND 10 TO 15
KNOTS JUST ABOVE THE SURFACE. CONFIDENCE CERTAINLY NOT HIGH FOR
ANY GOG. DID INCLUDE A 6SM BR AT BOTH SITES. LATER SHIFTS WILL
HAVE TO MONITOR WINDS AND IF LIGHTER MAY HAVE TO LOWER
VISIBILITIES.
&&
.CLIMATE...THROUGH EARLY NEXT WEEK
303 PM CDT MON MAR 12 2012
WELL ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGHOUT MUCH OF THE
NEXT 7 DAYS AND LIKELY BEYOND. AT LA CROSSE AND ROCHESTER...THE NEXT
3 DAYS APPEAR TO BE RELATIVE MINIMUMS FOR WHAT THE GOING RECORDS
ARE...SO ANY OF THE DAYS WILL HOLD A CHANCE FOR BREAKING THE RECORD.
WEDNESDAY STILL LOOKS LIKE THE WARMEST DAY OF THE WEEK AND HOLDS THE
HIGHEST POTENTIAL FOR BREAKING THE RECORDS WITH HIGHS EXPECTED IN
THE 70S. A FEW PLACES COULD EVEN APPROACH 80. HEADING INTO THE
WEEKEND AND EARLY NEXT WEEK...RECORDS VARY IN TERMS OF HOW HIGH THEY
ARE...BUT DEFINITELY POTENTIAL EXISTS FOR MORE RECORDS TO BE BROKEN.
SEE OUR WEBSITE FOR A LISTING OF RECORD HIGHS THROUGH EARLY NEXT
WEEK.
&&
.HYDROLOGY...
1232 PM CDT MON MAR 12 2012
ACCORDING TO OFFICIALS THERE HAVE BEEN SOME LOCALIZED ICE BLOCKAGES
ALONG THE BLACK RIVER FROM AROUND THE NEILLSVILLE AREA DOWN TO THE
UPPER PORTION OF LAKE ARBUTUS NEAR HATFIELD. REPORTS INDICATE THAT
THERE ARE LARGE BLOCKS OF ICE MOVING DOWN THE RIVER...AND THEY ARE
OCCASIONALLY GETTING HUNG UP ON RIVER BENDS AND WHERE ROCKS CAUSE
CONSTRICTIONS IN THE RIVER.
AT THIS POINT...IT DOES NOT APPEAR THERE IS A LARGE RISK FOR
FLOODING DUE TO ICE JAMS. BUT THERE IS A RISK FOR RAPID WITHIN-BANK
RISES ALONG THE BLACK RIVER DUE TO THIS ICE ACTION. WE HAVE ALREADY
SEEN SOME RISES ON THE RIVER MONITORING GAUGES IN THAT AREA.
THERE IS STILL SOME SNOW COVER OVER THE HEADWATER OF THE BLACK RIVER
BASIN...FROM WITHEE UP TO MEDFORD. WITH THE WARM TEMPERATURES
EXPECTED THIS WEEK...THAT SNOW IS EXPECTED TO MELT AND RUNOFF
QUICKLY INTO THE RIVER. THE ICE THAT REMAINS IN THE RIVER IS
EXPECTED TO BREAK UP AND MOVE DOWNSTREAM...SO WATER LEVELS WILL NEED
TO BE MONITORED THIS WEEK AS THAT COMBINATION WILL LEAD TO HIGHER
WATER ALONG THE BLACK RIVER THIS WEEK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
303 PM CDT MON MAR 12 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
CLIMATE...AJ
HYDROLOGY...MW
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1232 PM CDT MON MAR 12 2012
.SHORT TERM...TODAY THROUGH THURSDAY
315 AM CDT MON MAR 12 2012
THE MAIN FOCUS IN THE SHORT TERM IS WITH THE RAIN SHOWERS AND
POSSIBLE THUNDERSTORMS TODAY FOLLOWED BY THE RETURN OF NEAR RECORD
BREAKING TEMPERATURES THROUGH MID WEEK.
A MID TO UPPER LEVEL LOW CURRENTLY CENTERED OVER THE IOWA/NEBRASKA
BORDER WILL CONTINUE TO PROPAGATE NORTHEASTWARD INTO THE UPPER
MISSISSIPPI RIVER VALLEY BEFORE GETTING INTO THE GREAT LAKES BY
THIS EVENING. THE LEADING MOISTURE CHANNEL OUT OF THE GULF HAS
PUSHED INTO THE REGION WITH A NORTHWARD ADVANCING LIGHT TO
MODERATE RAIN BAND THAT IS ALREADY CLEAR OF NORTHEAST IOWA. THIS
BAND OF RAIN WILL CONTINUE TO MOVE NORTHWARD THIS MORNING WITH
MORE SCATTERED RAIN SHOWERS TO CONTEND WITH THROUGH THE REST OF
THE DAYTIME HOURS AS THE CORE OF THE LOW APPROACHES FROM THE
SOUTHWEST. THESE SHOWERS SHOULD END FROM WEST TO EAST THIS
AFTERNOON AND EVENING AS THE CORE OF THE TROUGH PASSES THROUGH.
THE MAIN QUESTION ABOUT TODAY IS WHETHER ANY CONVECTION WILL BE
ABLE TO DEVELOP...PARTICULARLY ACROSS WESTERN WISCONSIN. AS THE
CORE OF THE MID LEVEL LOW MOVES IN...THE LOW TO MID LEVEL PORTION
OF THE ATMOSPHERE WILL COOL WHICH WILL STEEPEN THE LAPSE RATES
ACROSS MUCH OF THE REGION. HOW MUCH INSTABILITY CAN DEVELOP WILL
DEPEND ON SURFACE TEMPERATURES WHICH WILL LIKELY BE HAMPERED BY A
BROKEN TO OVERCAST LOW LEVEL CLOUD DECK THIS MORNING AND
AFTERNOON. BY THE TIME ANY CLEARING STARTS TO GET IN...THE BETTER
FORCING WILL BE OFF TO THE EAST IN THE GREAT LAKES. WIND SHEAR
PROFILES GET BETTER THE FURTHER SOUTH AND EAST YOU GET FROM
WESTERN WISCONSIN AS A 70KT 500MB JET STREAK ROUNDS THE BASE OF
THE TROUGH FROM NORTHERN ILLINOIS INTO WESTERN MICHIGAN. THE
12.00Z NAM AND GFS BOTH DO PRODUCE A FEW HUNDRED J/KG OF MUCAPE
LATE THIS MORNING AND EARLY AFTERNOON BEFORE THE FORCING SHIFTS
OFF TO THE EAST...SO THE SLIGHT CHANCES FOR THUNDER STILL LOOK
WARRANTED. ANYTHING ORGANIZED...HOWEVER...SHOULD STAY OFF TO THE
EAST OF THE FORECAST AREA WHERE THE FORCING...SHEAR AND
INSTABILITY WILL BE BETTER MAXIMIZED.
SKIES WILL CLEAR OUT TONIGHT AS A RIDGE OF HIGH PRESSURE FOLLOWS
QUICKLY ON THE HEELS OF THIS SYSTEM WITH THE RIDGE AXIS MOVING
THROUGH THE FORECAST AREA BY TUESDAY NIGHT. AS A
RESULT...TEMPERATURES WILL QUICKLY REBOUND AS THE LOW LEVEL FLOW
COMES BACK AROUND TO THE SOUTH. THIS LOW LEVEL WARM AIR ADVECTION
WILL INCREASE GOING INTO WEDNESDAY WITH 850MB TEMPERATURES WARMING
TO AROUND +17C OFF OF THE 12.00Z NAM AND GFS. THIS LEADS TO 850MB
TEMPERATURE ANOMALIES OF +2 TO +3 STANDARD DEVIATIONS ON
WEDNESDAY...WHICH IS TYPICAL OF RECORD BREAKING TEMPERATURES.
THUS...WITH FORECAST SOUNDINGS LOOKING VERY DRY AND CAPPED...HAVE
BUMPED HIGHS INTO THE LOW TO MID 70S ACROSS MUCH OF THE REGION
WHICH WOULD LIKELY BREAK MANY RECORDS. THE COLD FRONT NOW IS BEING
FORECAST TO COME THROUGH THE REGION WEDNESDAY NIGHT...BUT DOES NOT
APPEAR TO HAVE PRECIPITATION FORM ALONG IT UNTIL IT IS INTO THE
GREAT LAKES REGION WHEN THE MID LEVEL FORCING STRENGTHENS.
.LONG TERM...THURSDAY NIGHT THROUGH SUNDAY NIGHT
315 AM CDT MON MAR 12 2012
THE MAIN CERTAINTY IN THE EXTENDED TIME FRAME IS THAT WITH THE
SOUTHWESTERLY FLOW ALOFT...OUR TEMPERATURES WILL REMAIN WELL ABOVE
NORMAL WITH MORE RECORDS POSSIBLY GOING DOWN. OTHERWISE...THE
12.00Z GFS AND ECMWF CONTINUE TO HINT AT SOME ENHANCED LOW LEVEL
MOISTURE TRANSPORT GOING INTO NEXT WEEKEND AS THE TROUGH STARTS TO
DIG SOUTH ACROSS THE ROCKIES. THIS MAY LEAD TO SOME DIURNAL SHOWER
AND THUNDERSTORM CHANCES THROUGH MUCH OF THE EXTENDED. THE TIMING
OF ANY MID LEVEL SHORT WAVE TROUGHS EJECTING NORTHEASTWARD OUT OF
THIS FLOW IS FAIRLY UNCERTAIN AT THIS POINT WITH THE EXTENDED
GUIDANCE NOT MATCHING UP WELL WITH THESE FEATURES. FOR NOW...HAVE
SOME LOW CHANCES FOR SHOWERS/THUNDER GOING THROUGH A GOOD CHUNK OF
THE EXTENDED PERIOD...BUT THESE LIKELY WOULD NOT BE ALL DAY RAINS.
&&
.AVIATION...THROUGH 18Z TUESDAY
1232 PM CDT MON MAR 12 2012
17Z WATER VAPOR IMAGERY SHOWS MID LEVEL LOW NOW OVER WEST CENTRAL
WISCONSIN. THIS LOW WILL CONTINUE TO LIFT NORTHEAST AWAY FROM THE
AREA. CEILINGS HAVE BEEN UNDULATING BETWEEN MVFR AND VFR SINCE
LATE MORNING...AS VISIBLE SATELLITE IMAGERY SHOWS SOME HOLES IN
THE CLOUDS. EXPECT THIS TREND TO CONTINUE THIS AFTERNOON AND WITH
SOME WEAK INSTABILITY WILL LIKELY SEE SOME SCATTERED SHOWERS THAT
MAY AFFECT THE TAF SITES FROM TIME TO TIME THROUGH 21Z. SURFACE
RIDGE MOVES IN FROM THE WEST TONIGHT. MODEL CONSENSUS IS FOR CLOUDS
TO CLEAR OUT BETWEEN 03Z-05Z WITH SKC AFTER THAT. WITH RIDGE AXIS
PUSHING INTO SOUTHEAST MINNESOTA LATE TONIGHT...QUESTION WILL BE
FOG POTENTIAL. BOTH THE 14.00Z NAM AND 14.15Z RUC BUFKIT SOUNDINGS
SHOWING WINDS AT THE SURFACE AROUND 5 TO 7 KNOTS...AND 10 TO 15
KNOTS JUST ABOVE THE SURFACE. CONFIDENCE CERTAINLY NOT HIGH FOR
ANY GOG. DID INCLUDE A 6SM BR AT BOTH SITES. LATER SHIFTS WILL
HAVE TO MONITOR WINDS AND IF LIGHTER MAY HAVE TO LOWER
VISIBILITIES.
&&
.CLIMATE...THIS WEEK
315 AM CDT MON MAR 12 2012
WITH ABOVE NORMAL TEMPERATURES TO CONTINUE THROUGH THE NEXT
WEEK...THERE WILL BE MANY OPPORTUNITIES TO BREAK THE RECORD HIGHS
AND HIGH MINIMUMS. AT LA CROSSE AND ROCHESTER...THE NEXT 5 DAYS
APPEAR TO BE RELATIVE MINIMUMS FOR WHAT THE GOING RECORDS ARE...SO
ANY OF THE DAYS THIS WEEK BESIDE TODAY WILL HOLD A CHANCE FOR
BREAKING THE RECORD. WEDNESDAY WILL LIKELY BE THE WARMEST OF THE
WEEK AND HOLDS THE HIGHEST POTENTIAL FOR BREAKING THE RECORDS WITH
HIGHS EXPECTED TO BE IN THE LOW TO MID 70S ACROSS THE REGION.
&&
.HYDROLOGY...
1232 PM CDT MON MAR 12 2012
ACCORDING TO OFFICIALS THERE HAVE BEEN SOME LOCALIZED ICE BLOCKAGES
ALONG THE BLACK RIVER FROM AROUND THE NEILLSVILLE AREA DOWN TO THE
UPPER PORTION OF LAKE ARBUTUS NEAR HATFIELD. REPORTS INDICATE THAT
THERE ARE LARGE BLOCKS OF ICE MOVING DOWN THE RIVER...AND THEY ARE
OCCASIONALLY GETTING HUNG UP ON RIVER BENDS AND WHERE ROCKS CAUSE
CONSTRICTIONS IN THE RIVER.
AT THIS POINT...IT DOES NOT APPEAR THERE IS A LARGE RISK FOR
FLOODING DUE TO ICE JAMS. BUT THERE IS A RISK FOR RAPID WITHIN-BANK
RISES ALONG THE BLACK RIVER DUE TO THIS ICE ACTION. WE HAVE ALREADY
SEEN SOME RISES ON THE RIVER MONITORING GAUGES IN THAT AREA.
THERE IS STILL SOME SNOW COVER OVER THE HEADWATER OF THE BLACK RIVER
BASIN...FROM WITHEE UP TO MEDFORD. WITH THE WARM TEMPERATURES
EXPECTED THIS WEEK...THAT SNOW IS EXPECTED TO MELT AND RUNOFF
QUICKLY INTO THE RIVER. THE ICE THAT REMAINS IN THE RIVER IS
EXPECTED TO BREAK UP AND MOVE DOWNSTREAM...SO WATER LEVELS WILL NEED
TO BE MONITORED THIS WEEK AS THAT COMBINATION WILL LEAD TO HIGHER
WATER ALONG THE BLACK RIVER THIS WEEK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1209 AM CDT MON MAR 12 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RABERDING
CLIMATE...HALBACH
HYDROLOGY...MW