Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 03/17/12
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
101 PM CDT THU MAR 15 2012
.AVIATION...15/18Z TAF CYCLE
LOW CLOUDS ONCE AGAIN NOTED ACRS THE FA ATTM...WITH SOME LINGERING
MVFR CIGS NOTED OVR SERN AR. VFR CONDS ARE EXPECTED TO PREVAIL
THRU MUCH OF THE FCST PD. MOST OF THE LATEST SHORT TERM MODEL DATA
INDC LIMITED CHCS OF ORGANIZED CONVECTION OVR THE AREA THIS AFTN
AND TNGT. THUS...CONTD WITH A MENTION OF VCTS FOR THE TIME BEING.
LOW CLOUDS ARE FCST TO REFORM LATER TNGT OVR MUCH OF THE AREA...
RESULTING IN OCNL MVFR CONDS INTO FRI MRNG. /44/
&&
.PREV DISCUSSION... /ISSUED 1040 AM CDT THU MAR 15 2012/
UPDATE...
HAVE TRIMMED BACK PRECIP CHANCES THROUGH 1PM. REGIONAL RADAR
TRENDS ALONG WITH RAPID UPDATE RUC GUIDANCE SUGGESTS VERY LITTLE
CHANCE OF PRECIP IN THE SOUTHERN HALF OF THE STATE THROUGH MIDDAY.
HAVE FOLLOWED THIS TREND AND REMOVED MENTION OF PRECIP FOR AREAS
SOUTH OF A LINE FROM RUSSELLVILLE TO JUST NORTH OF SEARCY AND UP
THROUGH ROUGHLY NEWPORT IN THE EAST. NORTH OF THAT LINE...HAVE
ISOLATED TO SCATTERED SHOWER/THUNDERSTORMS MENTIONED THROUGH 1PM.
MADE ONLY SOME SLIGHT ADJUSTMENTS TO THE AFTERNOON/EVENING
POPS...WITH HIGHEST POPS STILL IN THE NORTH AND EAST.
PREV DISCUSSION... /ISSUED 248 AM CDT THU MAR 15 2012/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
THE NEAR TERM WILL FEATURE A LARGE STORM SYSTEM DIGGING IN THE
SOUTHWEST UNITED STATES...AND A RIDGE BUILDING IN THE SOUTHEAST.
ARKANSAS WILL BE BETWEEN THESE FEATURES...WITH A PERSISTENT
SOUTHWEST WIND FLOW ALOFT...WELL ABOVE NORMAL TEMPERATURES...AND
ENOUGH MOISTURE TO FUEL ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS.
THERE WILL NOT BE MUCH TO TRIGGER PRECIPITATION OTHER THAN AFTERNOON
HEATING. PIECES OF ENERGY WILL PERIODICALLY RIDE THE FLOW INTO
THE REGION...AND THIS WILL LEAD TO MORE ORGANIZED CONVECTION. SUCH
WILL BE THE CASE TODAY...ESPECIALLY IN NORTHERN/CENTRAL ARKANSAS.
IN FACT...A SEVERE STORM OR TWO MAY POP UP. ANOTHER MORE ORGANIZED
EVENT MIGHT UNFOLD FRIDAY NIGHT/SATURDAY MORNING IN THE
NORTH/WEST.
NOT LOOKING FOR WIDESPREAD HEAVY RAIN THROUGH THE WEEKEND. IN
FACT...JUST AS WITH A SUMMERTIME PATTERN...SOME SPOTS MAY NOT GET
ANY RAIN AT ALL GIVEN HIT AND MISS PRECIPITATION.
LONG TERM...MONDAY THROUGH WEDNESDAY
AMPLIFIED PATTERN WILL CONTINUE THROUGH THE EXTENDED...WITH VERY
LITTLE CHANGE TO THE GOING FORECAST. DIURNAL CONVECTION WILL
CONTINUE FOR MONDAY...BEFORE LARGE UPPER LOW OVER THE DESERT
SOUTHWEST WILL SLOWLY MOVE EAST FOR THE MIDDLE OF THE WEEK. HAVE
GONE WITH THE SLOWER EUROPEAN GUIDANCE...WITH RAIN CHANCES
CONTINUING THROUGH THE END OF THE LONG TERM. WITH SOUTHWEST FLOW
PREVAILING...ABOVE NORMAL TEMPERATURES WILL CONTINUE.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1040 AM CDT THU MAR 15 2012
.UPDATE...
HAVE TRIMMED BACK PRECIP CHANCES THROUGH 1PM. REGIONAL RADAR
TRENDS ALONG WITH RAPID UPDATE RUC GUIDANCE SUGGESTS VERY LITTLE
CHANCE OF PRECIP IN THE SOUTHERN HALF OF THE STATE THROUGH MIDDAY.
HAVE FOLLOWED THIS TREND AND REMOVED MENTION OF PRECIP FOR AREAS
SOUTH OF A LINE FROM RUSSELLVILLE TO JUST NORTH OF SEARCY AND UP
THROUGH ROUGHLY NEWPORT IN THE EAST. NORTH OF THAT LINE...HAVE
ISOLATED TO SCATTERED SHOWER/THUNDERSTORMS MENTIONED THROUGH 1PM.
MADE ONLY SOME SLIGHT ADJUSTMENTS TO THE AFTERNOON/EVENING
POPS...WITH HIGHEST POPS STILL IN THE NORTH AND EAST.
&&
.PREV DISCUSSION... /ISSUED 248 AM CDT THU MAR 15 2012/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
THE NEAR TERM WILL FEATURE A LARGE STORM SYSTEM DIGGING IN THE
SOUTHWEST UNITED STATES...AND A RIDGE BUILDING IN THE SOUTHEAST.
ARKANSAS WILL BE BETWEEN THESE FEATURES...WITH A PERSISTENT
SOUTHWEST WIND FLOW ALOFT...WELL ABOVE NORMAL TEMPERATURES...AND
ENOUGH MOISTURE TO FUEL ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS.
THERE WILL NOT BE MUCH TO TRIGGER PRECIPITATION OTHER THAN AFTERNOON
HEATING. PIECES OF ENERGY WILL PERIODICALLY RIDE THE FLOW INTO
THE REGION...AND THIS WILL LEAD TO MORE ORGANIZED CONVECTION. SUCH
WILL BE THE CASE TODAY...ESPECIALLY IN NORTHERN/CENTRAL ARKANSAS.
IN FACT...A SEVERE STORM OR TWO MAY POP UP. ANOTHER MORE ORGANIZED
EVENT MIGHT UNFOLD FRIDAY NIGHT/SATURDAY MORNING IN THE
NORTH/WEST.
NOT LOOKING FOR WIDESPREAD HEAVY RAIN THROUGH THE WEEKEND. IN
FACT...JUST AS WITH A SUMMERTIME PATTERN...SOME SPOTS MAY NOT GET
ANY RAIN AT ALL GIVEN HIT AND MISS PRECIPITATION.
LONG TERM...MONDAY THROUGH WEDNESDAY
AMPLIFIED PATTERN WILL CONTINUE THROUGH THE EXTENDED...WITH VERY
LITTLE CHANGE TO THE GOING FORECAST. DIURNAL CONVECTION WILL
CONTINUE FOR MONDAY...BEFORE LARGE UPPER LOW OVER THE DESERT
SOUTHWEST WILL SLOWLY MOVE EAST FOR THE MIDDLE OF THE WEEK. HAVE
GONE WITH THE SLOWER EUROPEAN GUIDANCE...WITH RAIN CHANCES
CONTINUING THROUGH THE END OF THE LONG TERM. WITH SOUTHWEST FLOW
PREVAILING...ABOVE NORMAL TEMPERATURES WILL CONTINUE.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 80 61 79 59 / 60 30 30 20
CAMDEN AR 84 62 80 62 / 30 20 10 20
HARRISON AR 79 59 78 59 / 50 20 20 30
HOT SPRINGS AR 81 61 78 61 / 30 20 20 20
LITTLE ROCK AR 83 62 79 60 / 40 20 20 20
MONTICELLO AR 84 62 80 63 / 30 20 10 10
MOUNT IDA AR 79 61 76 60 / 30 20 20 20
MOUNTAIN HOME AR 80 60 79 59 / 60 30 30 30
NEWPORT AR 80 62 79 60 / 50 30 30 20
PINE BLUFF AR 83 62 80 62 / 30 20 10 10
RUSSELLVILLE AR 80 60 78 59 / 40 20 20 30
SEARCY AR 82 61 79 60 / 40 20 20 20
STUTTGART AR 82 61 79 61 / 40 20 20 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
64
AREA FORECAST DISCUSSION
NWS ALBANY NY
641 AM EDT THU MAR 15 2012
.SYNOPSIS...
A WEAK DISTURBANCE WILL BRING SCATTERED SHOWERS AND PERHAPS A RUMBLE
OF THUNDER FROM ALBANY NORTH AND WEST EARLY IN THE MORNING. THEN
AFTER A BREAK IN THE ACTION...A STRONGER DISTURBANCE...LINKED WITH A
MID LEVEL WARM FRONT...WILL BRING A BETTER CHANCE OF SHOWERS AND
ANOTHER THUNDERSTORM LATER TONIGHT INTO FRIDAY. HIGH PRESSURE WILL
SLOWLY BUILD IN FRIDAY NIGHT INTO SATURDAY BRING DRIER CONDITIONS
ALONG WITH VERY MILD TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 630 AM...KEEPING UP WITH THE DISTURBANCE BRINGING ISOLATED TO
SCATTERED SHOWERS FROM THE ADIRONDACKS...SOUTHEAST TO THE CAPITAL
REGION. THERE HAVE BEEN FEW IF ANY CLOUD TO GROUND LIGHTNING STRIKES
IN THE LAST HOUR OR SO. HOWEVER...UPSTREAM...CLOSER TO
ONTARIO...STILL A FEW STRIKES. HAVE WORDED IT SLIGHT CHANCE OF
THUNDER FOR A COUPLE OF HOURS.
TEMPERATURES HAVE BOTTOMED OUT GENERALLY IN THE 30S...EXCEPT 20S
WHERE THERE HAS BEEN SNOW COVER AND CLEAR SKY. IT APPEARS ANY AREAS
GETTING SHOWERS SHOULD BE ABOVE FREEZING.
THE 06Z NAM HAD ABSOLUTELY NO EVIDENCE OF THEM ON THE PLANAR VIEW.
THE LATEST HRRR AND RUC HAD FORECASTED SOME ACTIVITY BUT IN THE
WRONG PLACES AND WRONG TIMES.
THIS SHORT-WAVE...POORLY FORECASTED BY THE MODELS...HAS BEEN
RE-TOOLED IN GFE. THE SHOWERS ASSOCIATED WILL WEAKEN AS IT MOVES
AWAY FROM ITS THETA-E SOURCE.
AFTER THE DISTURBANCE MOVES THROUGH LATER THIS MORNING...IT LOOKS
DRY THROUGH MUCH OF THE AFTERNOON. HOWEVER... A STRONGER DISTURBANCE
EVIDENT ON THE H20 LP OVER THE NORTHWESTERN GREAT LAKES WILL HEAD
TOWARD OUR REGION...BUT NOT UNTIL VERY LATE IN THE DAY OR MORE
LIKELY...EVENING.
THE 11U-3.9U INDICATED MOST OF THE STRATUS HAS NOT MADE INTO OUR
SOUTHERN REGION.
ONCE THE CLOUDS ASSOCIATED WITH THE DISTURBANCE MOVES ON BY TO OUR
SOUTHEAST LATER TODAY...SOME SUNSHINE IS EXPECTED BEFORE CLOUDS TEND
TO INCREASE LATER THIS MORNING BEFORE THE NEXT BATCH OF CLOUDS ROLL
IN.
WE EXPECT HIGH TEMPERATURES SOMEWHAT SIMILAR TO WEDNESDAY/S
GENERALLY IN THE 50S. THE MID HUDSON VALLEY AND LOWER LITCHFIELD
AREA WILL BE COOLER THAN YESTERDAY AS THE WIND FLOW WILL BE
SOUTHEAST...SO THEREFORE NO BENEFICIAL DOWNSLOPE WILL ENSUE OFF THE
CATSKILLS...TOPPING OUT AROUND 60.
ONCE AGAIN HOWEVER...THESE VALUES WILL BE RUNNING AT LEAST 10
DEGREES ABOVE NORMAL FOR MID MARCH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT INTO FRIDAY AFTERNOON...THE AFOREMENTIONED SHORTWAVE ALONG
WITH IT/S WEAK SFC LOW REFLECTION WILL BE MOVING FROM THE GREAT
LAKES SOUTHEASTWARD TOWARDS UPSTATE NY. THIS WILL ALLOW FOR LIKELY
SHOWERS AND THE CHANCE OF THUNDERSTORMS ACROSS OUR AREA...MAINLY
OVERNIGHT. SHOWALTER VALUES CONTINUE SLIGHTLY NEGATIVE...AND MIXED
LAYER MUCAPE VALUES RANGE BETWEEN 0 AND 400 J/KG. WHILE THERE MAY BE
A FEW RUMBLES OF THUNDER AROUND...AND 850-500 HPA LAPSE RATES WILL
BE AROUND 6.5 DEGREES C/KM...IT/S UNLIKELY ANY STORM WOULD BECOME
STRONG DUE TO THE RELATIVELY LOW DEWPOINT TEMPS AND MEAGER CAPE.
OVERNIGHT LOW TEMPERATURES WILL WITH THE CLOUDS AND ANTICIPATED
SHOWER ACTIVITY...OVERNIGHT LOWS WILL BE MILD TONIGHT...WITH MOST
AREAS IN THE UPPER 30S TO MID 40S. TEMPERATURES ON FRIDAY WILL BE A
LITTLE COOLER THAN RECENT DAYS...BUT STILL MILD FOR THIS TIME OF
YEAR...MAINLY IN THE MID OR UPPER 50S. (A FEW READINGS AROUND 60 IN
THE MID HUDSON VALLEY).
BY FRIDAY EVENING...THE DISTURBANCE WILL BE PASSING EAST OF THE
REGION AND A DRYING TREND WILL SET IN. AN UPPER LEVEL RIDGE OVER THE
MIDWEST WILL BUILD INTO THE AREA FOR THE OVERNIGHT
HOURS...ALLOWING THE THREAT FOR SHOWERS TO END. A SURFACE HIGH WILL
BUILDING SOUTHWARD FROM CANADA. THIS SETUP USUALLY POSES A CHALLENGE
TO HOW QUICKLY WE CLEAR OUT...AS MOISTURE COULD EASILY GET TRAPPED
UNDERNEATH AN LOWERING INVERSION. THUS FAR...MODELS ARE OPTIMISTIC
THAT CLOUDS WILL AT LEAST THIN. HOWEVER IF THEY DO...CHANCES FOR FOG
WILL INCREASE. FOR NOW...WENT PARTLY CLOUDY WITH PATCHY FOG.
ASSUMING THIS MIDDLE OF THE ROAD SCENARIO...TEMPERATURES WILL DIP TO
THE MID 30S TO LOWER 40S. IF CLOUDS WERE TO PERSIST...OVERNIGHT LOWS
WOULD BE A LITTLE MILDER. ON THE OTHER HAND...IF WE WERE TO CLEAR
MORE QUICKLY...READINGS COULD DIP A BIT LOWER...ALLOWING MORE
EXTENSIVE FOG TO POSSIBLY FORM.
SATURDAY...HIGH TEMPERATURES WILL TRICKY TO FORECAST. WE ASSUME A
GOOD DEAL OF SUNSHINE. HOWEVER...THE MEAN AIR FLOW WILL BE SSE (AS
OPPOSED TO SSW) SO THERE COULD BE LINGERING MARINE INFLUENCES. THE
MET GUIDANCE (OFF THE NAM MODEL) INDICATED TEMPERATURES ONLY
REACHING THE 50S ON SATURDAY WHILE THE MAV GUIDANCE (BASED OFF THE
GFS MODEL) INDICATE MUCH WARMER READINGS WELL INTO THE 60S...SOME 15
DEGREES HIGHER THAN THE METS IN SOME CASES.
IF LOW CLOUDS WERE TO BACK IN (OR NEVER BURN OFF) THE MET VALUES
WOULD BE MORE CORRECT. HOWEVER...SINCE WE ARE BANKING ON MORE
SUNSHINE...LEANED WITH (BUT NOT QUITE ALL THE WAY) THE WARMER MAV
GUIDANCE. THIS WOULD TRANSLATE TO HIGHS MAINLY IN THE 60S ON
SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
WHILE CONFIDENCE REMAINS ABOVE NORMAL FOR UNSEASONABLY MILD
TEMPERATURES DURING THIS LONG TERM PERIOD OF THE FORECAST...AS
DISCUSSED THIS TIME YESTERDAY...THERE REMAINS CAVEATS THAT COULD
DISRUPT TRANQUIL CONDITIONS.
LATEST GLOBAL MODEL TRENDS CONTINUE TO SUPPORT A TRANQUIL END TO THE
WEEKEND AS BOTH THE SURFACE RIDGE AND POSITIVE HEIGHT ANOMALIES
ALOFT ARE EXPECTED TO BE OVER THE MID ATLANTIC AND NORTHEAST.
THEREAFTER...WE TURN UPSTREAM AS THE COMBINATION OF INCREASED
INSTABILITY AND SHORT WAVE TIMING BECOME INCREASINGLY MORE
PROBLEMATIC.
GFS/ECMWF ARE IN SOME AGREEMENT WITH AN MCS-LIKE FEATURE DEVELOPING
OVER THE MID MISSISSIPPI RIVER VALLEY DURING THIS WEEKEND. THIS MCV
PROPAGATES NORTHWARD ALONG THE BACKSIDE OF THIS DEVELOPING RIDGE
AXIS ALONG THE EASTERN SEABOARD. THIS MCV ATTEMPTS TO FIND A
WEAKNESS IN THE RIDGE AND MOVES ACROSS THE REGION LATE SUNDAY INTO
MONDAY. THIS MAY DISRUPT THE FULL INSOLATION AND KEEP TEMPERATURES
DOWN A LITTLE THAN PREVIOUS FORECASTS ALONG WITH A RENEWED CHANCE
FOR CONVECTION.
BOTH THE GFS AND ECMWF NOW SUGGEST MOISTURE BECOMES TRAPPED UNDER
THOSE INCREASING HEIGHTS ALOFT FOR MORE CLOUD COVER. AS 850MB TEMPS
CLIMB AT OR ABOVE 10C...EVEN WITH THE CLOUDS...WE SHOULD BE ABLE TO
CLIMB INTO THE LOWER HALF OF THE 70S FOR VALLEY LOCATIONS AND 60S
FOR THE HIGHER TERRAIN.
THE BEST CHANCE FOR PORTIONS OF THE REGION TO PERHAPS TOUCH THE 80
DEGREE MARK DOES APPEAR TO BE ON WEDNESDAY WITH NEAR +12C AND AN
INCREASE SOUTHERLY FLOW.
AS FOR RECORDS DURING THIS PERIOD...HERE ARE ALBANY STATS...
DATE TEMP YEAR
SUN MAR 18 65 1966
MON MAR 19 75 1894
TUE MAR 20 74 1903
WED MAR 21 78 1921
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
EXTREMELY CHALLENGING FORECAST REMAIN THROUGH TODAY.
A NARROW BAND OF SHOWERS WAS MOVING ACROSS THE MOHAWK VALLEY INTO
THE SOUTHERN PORTIONS OF THE CAPITAL REGION AND TACONICS. THIS WAS
ALONG THE WARM FRONT THAT WAS ATTEMPTING TO LIFT NORTH. ADDITIONAL
SHOWERS ARE SEEN UPSTREAM BUT IT REMAINS UNCLEAR JUST HOW MUCH WILL
MIGRATE SOUTH AND IMPACT THE TAF SITES. WE WILL CONTINUE WITH THE
VCSH UNTIL TRENDS BECOME MORE EVIDENT.
NEXT ISSUE IS THE CLOUD COVER. AS SEEN IN THE 11U-3.9U
IMAGERY...THE EDGE OF THE IFR CIGS WERE CLOSE TO KGFL AND KPOU /KGFL
JUST WENT INTO IFR/. ONCE THE MARCH SUNSHINE IS ABLE TO HEAT THE
BOUNDARY LAYER...WE SHOULD SEE THIS CIG RISE ABOVE IFR THRESHOLDS
AND WILL DO SO IN THE TAF FORECAST THIS MORNING WITH A TEMPO GROUP
FOR IFR CIGS.
WINDS THIS MORNING ARE LIGHT AND GENERALLY NORTHEAST TO EAST...WITH
EXPECTATIONS FOR THOSE WINDS TO SHIFT TOWARD A SOUTHEAST DIRECTION
AT SPEEDS 10KTS OR LESS.
OUTLOOK...
THU OVERNIGHT...MVFR/IFR...-SHRA. ISOLD -TSRA.
FRI-FRI EVENING...MVFR...SCT-NUMEROUS -SHRA AND ISOLD -TSRA.
FRI NT-SUN...VFR. NO SIG WX.
SUN NT-MON...VFR/MVFR. CHC -SHRA/-TSRA.
&&
.FIRE WEATHER...
RH VALUES WILL REMAIN HIGHER THAN YESTERDAY...BOTTOMING IN THE
MODERATE RANGE (40-60 PERCENT). 10 METER WINDS WILL BE SOUTH OR
SOUTHEAST GENERALLY AROUND 10 MPH OR LESS. THERE WILL ISOLATED
SHOWERS AND POSSIBLY A THUNDERSTORM THIS MORNING AND POSSIBLY BY
LATE IN THE DAY. MOST OF THE DAY WILL BE RAINFREE AND ANY RAINFALL
WILL AVERAGE WELL BELOW A QUARTER OF AN INCH.
THERE WILL BE MORE CLOUDS THAN WEDNESDAY BUT ALSO TIMES OF
SUNSHINE...ESPECIALLY MIDDAY.
SHOWERS WILL BECOME MORE LIKELY LATER TONIGHT AND FRIDAY AS A
DISTURBANCE AND ELEVATED WARM FRONT MOVE ACROSS THE REGION. A
QUARTER OF AN INCH OF RAIN OR MORE IS POSSIBLE...ESPECIALLY NORTH
AND WEST OF ALBANY. RH LEVELS WILL REMAIN ELEVATED ON FRIDAY
(GENERALLY HIGHER THAN 60 PERCENT).
DRY WEATHER RETURNS FRIDAY NIGHT INTO THE WEEKEND. IT WILL BECOME
UNSEASONABLY WARM WITH SOME SUNSHINE EXPECTED BOTH WEEKEND DAYS.
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE NEXT MONDAY.
&&
.HYDROLOGY...
NO HYDROLOGIC ISSUES ARE ANTICIPATED OVER THE NEXT 5 DAYS.
ISOLATED SHOWERS AND THUNDERSTORMS SHOULD HAVE NO EFFECT ON RUNOFF.
IN FACT...IN SOME CASES THE PRECIPITATION MIGHT FALL AS FREEZING
RAIN (ALBEIT VERY LIGHT).
MORE SHOWER ACTIVITY IS LIKELY TONIGHT INTO EARLY FRIDAY. AT THIS
POINT RAINFALL AMOUNTS LOOK FAIRLY LIGHT...PERHAPS APPROACHING HALF
AN INCH IN OUR NORTHWESTERN ZONES...BUT GENERALLY AROUND A QUARTER
OF AN INCH OR LESS THROUGH THE REMAINDER OF OUR HYDROLOGICAL
FORECAST AREA.
THIS RAINFALL COULD PRODUCE WELL WITHIN BANK RISES ON SOME STREAMS
AND RIVERS...ESPECIALLY THOSE NORTHWEST OF ALBANY.
THE LATEST NOHRSC MODELED SNOW COVERAGE CONTINUES TO SHOW SEVERAL
INCHES OF WATER EQUIVALENT ACROSS THE ADIRONDACKS AND GREEN
MOUNTAINS. ALTHOUGH NOT MODELED...SOME SMALL AMOUNTS OF SNOW ARE
STILL PROBABLY IN PLACE ACROSS THE HIGHEST ELEVATIONS OF THE
BERKSHIRES...AND HIGH PEAKS OF THE CATSKILLS IN GREENE AND ULSTER
COUNTIES. WARM TEMPERATURES DURING THE DAYTIME HOURS OVER THE NEXT
SEVERAL DAYS...ESPECIALLY THIS WEEKEND...WILL ALLOW FOR CONTINUED
SNOW MELT...ALTHOUGH RATES SHOULD SLOW DOWN AT NIGHT WITH
TEMPERATURES DROPPING INTO THE 30S TO LOW 40S ACROSS THE HIGH
TERRAIN. BECAUSE OF THIS GRADUAL MELTING...AND NO HEAVY
PRECIPITATION EXPECTED ANYTIME SOON...NO RIVER PROBLEMS ARE
ANTICIPATED...AND THE SHORT-TERM HYDROLOGIC ENSEMBLE SHOWS NO RIVERS
IN OUR AREA EVEN REACHING ACTION STAGE OVER THE NEXT SEVERAL DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...FRUGIS/HWJIV
LONG TERM...BGM
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
638 AM EDT THU MAR 15 2012
.SYNOPSIS...
A WEAK DISTURBANCE WILL BRING SCATTERED SHOWERS AND PERHAPS A RUMBLE
OF THUNDER FROM ALBANY NORTH AND WEST EARLY IN THE MORNING. THEN
AFTER A BREAK IN THE ACTION...A STRONGER DISTURBANCE...LINKED WITH A
MID LEVEL WARM FRONT...WILL BRING A BETTER CHANCE OF SHOWERS AND
ANOTHER THUNDERSTORM LATER TONIGHT INTO FRIDAY. HIGH PRESSURE WILL
SLOWLY BUILD IN FRIDAY NIGHT INTO SATURDAY BRING DRIER CONDITIONS
ALONG WITH VERY MILD TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 530 AM...SHOWERS AND ISOLATED THUNDERSTORMS MOVING QUICKLY
INTO THE MOHAWK VALLEY. THE 06Z NAM HAD ABSOLUTELY NO EVIDENCE OF
THEM ON THE PLANAR VIEW. THE LATEST HRRR AND RUC HAD FORECASTED SOME
ACTIVITY BUT IN THE WRONG PLACES AND WRONG TIMES.
THIS SHORT-WAVE...POORLY FORECASTED BY THE MODELS...HAS BEEN
RE-TOOLED IN GFE. WE ARE THINKING IT WILL WEAKEN AS IT MOVES AWAY
FROM ITS THETA-E SOURCE BUT STILL CARRY ISOLATED ACTIVITY PAST THE
GREATER CAPITAL DISTRICT THROUGH AT LEAST EARLY MORNING. THIS
ACTIVITY NOW STRETCHES BACK BEYOND LAKE ONTARIO SO WE MIGHT HAVE TO
EXTEND IT EVEN FURTHER INTO THE MORNING.
TEMPERATURES THIS MORNING WERE GENERALLY COLDER THIS MORNING THAN
PAST MORNING...AND IN SOME CASES...BELOW FREEZING (LIKE GLENS
FALLS). CONCERN IS THAT WITH SHOWERS MOVING INTO THESE REGIONS THERE
IS A REMOTE POSSIBILITY THAT FREEZING RAIN COULD FALL. WE WILL
MONITOR AND ISSUE MORE SPECIAL WEATHER STATEMENTS AS NEEDED.
AFTER THE DISTURBANCE MOVES THROUGH LATER THIS MORNING...IT LOOKS
DRY THROUGH MUCH OF THE AFTERNOON. HOWEVER... A STRONGER DISTURBANCE
EVIDENT ON THE H20 LP OVER THE NORTHWESTERN GREAT LAKES WILL HEAD
TOWARD OUR REGION...BUT NOT UNTIL VERY LATE IN THE DAY OR MORE
LIKELY...EVENING.
THE 11U-3.9U INDICATES THE STRATUS HAS NOT MADE MUCH PROGRESS
NORTHWARD OF LONG ISLAND WHILE AC AHEAD OF THE SHOWERS AND
THUNDERSTORMS WERE WORKING ACROSS THE MOHAWK VALLEY.
ONCE CLOUDS ASSOCIATED WITH THE DISTURBANCE MOVES ON BY TO OUR
SOUTHEAST LATER TODAY...SOME SUNSHINE IS EXPECTED BEFORE CLOUDS TEND
TO INCREASE LATER THIS MORNING BEFORE THE NEXT BATCH OF CLOUDS ROLL
IN.
WE EXPECT HIGH TEMPERATURES SOMEWHAT SIMILAR TO WEDNESDAY/S
GENERALLY IN THE 50S. THE MID HUDSON VALLEY AND LOWER LITCHFIELD
AREA WILL BE COOLER THAN YESTERDAY AS THE WIND FLOW WILL BE
SOUTHEAST...SO THEREFORE NO BENEFICIAL DOWNSLOPE WILL ENSUE OFF THE
CATSKILLS...TOPPING OUT AROUND 60.
ONCE AGAIN HOWEVER...THESE VALUES WILL BE RUNNING AT LEAST 10
DEGREES ABOVE NORMAL FOR MID MARCH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT INTO FRIDAY AFTERNOON...THE AFOREMENTIONED SHORTWAVE ALONG
WITH IT/S WEAK SFC LOW REFLECTION WILL BE MOVING FROM THE GREAT
LAKES SOUTHEASTWARD TOWARDS UPSTATE NY. THIS WILL ALLOW FOR LIKELY
SHOWERS AND THE CHANCE OF THUNDERSTORMS ACROSS OUR AREA...MAINLY
OVERNIGHT. SHOWALTER VALUES CONTINUE SLIGHTLY NEGATIVE...AND MIXED
LAYER MUCAPE VALUES RANGE BETWEEN 0 AND 400 J/KG. WHILE THERE MAY BE
A FEW RUMBLES OF THUNDER AROUND...AND 850-500 HPA LAPSE RATES WILL
BE AROUND 6.5 DEGREES C/KM...IT/S UNLIKELY ANY STORM WOULD BECOME
STRONG DUE TO THE RELATIVELY LOW DEWPOINT TEMPS AND MEAGER CAPE.
OVERNIGHT LOW TEMPERATURES WILL WITH THE CLOUDS AND ANTICIPATED
SHOWER ACTIVITY...OVERNIGHT LOWS WILL BE MILD TONIGHT...WITH MOST
AREAS IN THE UPPER 30S TO MID 40S. TEMPERATURES ON FRIDAY WILL BE A
LITTLE COOLER THAN RECENT DAYS...BUT STILL MILD FOR THIS TIME OF
YEAR...MAINLY IN THE MID OR UPPER 50S. (A FEW READINGS AROUND 60 IN
THE MID HUDSON VALLEY).
BY FRIDAY EVENING...THE DISTURBANCE WILL BE PASSING EAST OF THE
REGION AND A DRYING TREND WILL SET IN. AN UPPER LEVEL RIDGE OVER THE
MIDWEST WILL BUILD INTO THE AREA FOR THE OVERNIGHT
HOURS...ALLOWING THE THREAT FOR SHOWERS TO END. A SURFACE HIGH WILL
BUILDING SOUTHWARD FROM CANADA. THIS SETUP USUALLY POSES A CHALLENGE
TO HOW QUICKLY WE CLEAR OUT...AS MOISTURE COULD EASILY GET TRAPPED
UNDERNEATH AN LOWERING INVERSION. THUS FAR...MODELS ARE OPTIMISTIC
THAT CLOUDS WILL AT LEAST THIN. HOWEVER IF THEY DO...CHANCES FOR FOG
WILL INCREASE. FOR NOW...WENT PARTLY CLOUDY WITH PATCHY FOG.
ASSUMING THIS MIDDLE OF THE ROAD SCENARIO...TEMPERATURES WILL DIP TO
THE MID 30S TO LOWER 40S. IF CLOUDS WERE TO PERSIST...OVERNIGHT LOWS
WOULD BE A LITTLE MILDER. ON THE OTHER HAND...IF WE WERE TO CLEAR
MORE QUICKLY...READINGS COULD DIP A BIT LOWER...ALLOWING MORE
EXTENSIVE FOG TO POSSIBLY FORM.
SATURDAY...HIGH TEMPERATURES WILL TRICKY TO FORECAST. WE ASSUME A
GOOD DEAL OF SUNSHINE. HOWEVER...THE MEAN AIR FLOW WILL BE SSE (AS
OPPOSED TO SSW) SO THERE COULD BE LINGERING MARINE INFLUENCES. THE
MET GUIDANCE (OFF THE NAM MODEL) INDICATED TEMPERATURES ONLY
REACHING THE 50S ON SATURDAY WHILE THE MAV GUIDANCE (BASED OFF THE
GFS MODEL) INDICATE MUCH WARMER READINGS WELL INTO THE 60S...SOME 15
DEGREES HIGHER THAN THE METS IN SOME CASES.
IF LOW CLOUDS WERE TO BACK IN (OR NEVER BURN OFF) THE MET VALUES
WOULD BE MORE CORRECT. HOWEVER...SINCE WE ARE BANKING ON MORE
SUNSHINE...LEANED WITH (BUT NOT QUITE ALL THE WAY) THE WARMER MAV
GUIDANCE. THIS WOULD TRANSLATE TO HIGHS MAINLY IN THE 60S ON
SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
WHILE CONFIDENCE REMAINS ABOVE NORMAL FOR UNSEASONABLY MILD
TEMPERATURES DURING THIS LONG TERM PERIOD OF THE FORECAST...AS
DISCUSSED THIS TIME YESTERDAY...THERE REMAINS CAVEATS THAT COULD
DISRUPT TRANQUIL CONDITIONS.
LATEST GLOBAL MODEL TRENDS CONTINUE TO SUPPORT A TRANQUIL END TO THE
WEEKEND AS BOTH THE SURFACE RIDGE AND POSITIVE HEIGHT ANOMALIES
ALOFT ARE EXPECTED TO BE OVER THE MID ATLANTIC AND NORTHEAST.
THEREAFTER...WE TURN UPSTREAM AS THE COMBINATION OF INCREASED
INSTABILITY AND SHORT WAVE TIMING BECOME INCREASINGLY MORE
PROBLEMATIC.
GFS/ECMWF ARE IN SOME AGREEMENT WITH AN MCS-LIKE FEATURE DEVELOPING
OVER THE MID MISSISSIPPI RIVER VALLEY DURING THIS WEEKEND. THIS MCV
PROPAGATES NORTHWARD ALONG THE BACKSIDE OF THIS DEVELOPING RIDGE
AXIS ALONG THE EASTERN SEABOARD. THIS MCV ATTEMPTS TO FIND A
WEAKNESS IN THE RIDGE AND MOVES ACROSS THE REGION LATE SUNDAY INTO
MONDAY. THIS MAY DISRUPT THE FULL INSOLATION AND KEEP TEMPERATURES
DOWN A LITTLE THAN PREVIOUS FORECASTS ALONG WITH A RENEWED CHANCE
FOR CONVECTION.
BOTH THE GFS AND ECMWF NOW SUGGEST MOISTURE BECOMES TRAPPED UNDER
THOSE INCREASING HEIGHTS ALOFT FOR MORE CLOUD COVER. AS 850MB TEMPS
CLIMB AT OR ABOVE 10C...EVEN WITH THE CLOUDS...WE SHOULD BE ABLE TO
CLIMB INTO THE LOWER HALF OF THE 70S FOR VALLEY LOCATIONS AND 60S
FOR THE HIGHER TERRAIN.
THE BEST CHANCE FOR PORTIONS OF THE REGION TO PERHAPS TOUCH THE 80
DEGREE MARK DOES APPEAR TO BE ON WEDNESDAY WITH NEAR +12C AND AN
INCREASE SOUTHERLY FLOW.
AS FOR RECORDS DURING THIS PERIOD...HERE ARE ALBANY STATS...
DATE TEMP YEAR
SUN MAR 18 65 1966
MON MAR 19 75 1894
TUE MAR 20 74 1903
WED MAR 21 78 1921
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
EXTREMELY CHALLENGING FORECAST REMAIN THROUGH TODAY.
A NARROW BAND OF SHOWERS WAS MOVING ACROSS THE MOHAWK VALLEY INTO
THE SOUTHERN PORTIONS OF THE CAPITAL REGION AND TACONICS. THIS WAS
ALONG THE WARM FRONT THAT WAS ATTEMPTING TO LIFT NORTH. ADDITIONAL
SHOWERS ARE SEEN UPSTREAM BUT IT REMAINS UNCLEAR JUST HOW MUCH WILL
MIGRATE SOUTH AND IMPACT THE TAF SITES. WE WILL CONTINUE WITH THE
VCSH UNTIL TRENDS BECOME MORE EVIDENT.
NEXT ISSUE IS THE CLOUD COVER. AS SEEN IN THE 11U-3.9U
IMAGERY...THE EDGE OF THE IFR CIGS WERE CLOSE TO KGFL AND KPOU /KGFL
JUST WENT INTO IFR/. ONCE THE MARCH SUNSHINE IS ABLE TO HEAT THE
BOUNDARY LAYER...WE SHOULD SEE THIS CIG RISE ABOVE IFR THRESHOLDS
AND WILL DO SO IN THE TAF FORECAST THIS MORNING WITH A TEMPO GROUP
FOR IFR CIGS.
WINDS THIS MORNING ARE LIGHT AND GENERALLY NORTHEAST TO EAST...WITH
EXPECTATIONS FOR THOSE WINDS TO SHIFT TOWARD A SOUTHEAST DIRECTION
AT SPEEDS 10KTS OR LESS.
OUTLOOK...
THU OVERNIGHT...MVFR/IFR...-SHRA. ISOLD -TSRA.
FRI-FRI EVENING...MVFR...SCT-NUMEROUS -SHRA AND ISOLD -TSRA.
FRI NT-SUN...VFR. NO SIG WX.
SUN NT-MON...VFR/MVFR. CHC -SHRA/-TSRA.
&&
.FIRE WEATHER...
RH VALUES WILL REMAIN HIGHER THAN YESTERDAY...BOTTOMING IN THE
MODERATE RANGE (40-60 PERCENT). 10 METER WINDS WILL BE SOUTH OR
SOUTHEAST GENERALLY AROUND 10 MPH OR LESS. THERE WILL ISOLATED
SHOWERS AND POSSIBLY A THUNDERSTORM THIS MORNING AND POSSIBLY BY
LATE IN THE DAY. MOST OF THE DAY WILL BE RAINFREE AND ANY RAINFALL
WILL AVERAGE WELL BELOW A QUARTER OF AN INCH.
THERE WILL BE MORE CLOUDS THAN WEDNESDAY BUT ALSO TIMES OF
SUNSHINE...ESPECIALLY MIDDAY.
SHOWERS WILL BECOME MORE LIKELY LATER TONIGHT AND FRIDAY AS A
DISTURBANCE AND ELEVATED WARM FRONT MOVE ACROSS THE REGION. A
QUARTER OF AN INCH OF RAIN OR MORE IS POSSIBLE...ESPECIALLY NORTH
AND WEST OF ALBANY. RH LEVELS WILL REMAIN ELEVATED ON FRIDAY
(GENERALLY HIGHER THAN 60 PERCENT).
DRY WEATHER RETURNS FRIDAY NIGHT INTO THE WEEKEND. IT WILL BECOME
UNSEASONABLY WARM WITH SOME SUNSHINE EXPECTED BOTH WEEKEND DAYS.
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE NEXT MONDAY.
&&
.HYDROLOGY...
NO HYDROLOGIC ISSUES ARE ANTICIPATED OVER THE NEXT 5 DAYS.
ISOLATED SHOWERS AND THUNDERSTORMS SHOULD HAVE NO EFFECT ON RUNOFF.
IN FACT...IN SOME CASES THE PRECIPITATION MIGHT FALL AS FREEZING
RAIN (ALBEIT VERY LIGHT).
MORE SHOWER ACTIVITY IS LIKELY TONIGHT INTO EARLY FRIDAY. AT THIS
POINT RAINFALL AMOUNTS LOOK FAIRLY LIGHT...PERHAPS APPROACHING HALF
AN INCH IN OUR NORTHWESTERN ZONES...BUT GENERALLY AROUND A QUARTER
OF AN INCH OR LESS THROUGH THE REMAINDER OF OUR HYDROLOGICAL
FORECAST AREA.
THIS RAINFALL COULD PRODUCE WELL WITHIN BANK RISES ON SOME STREAMS
AND RIVERS...ESPECIALLY THOSE NORTHWEST OF ALBANY.
THE LATEST NOHRSC MODELED SNOW COVERAGE CONTINUES TO SHOW SEVERAL
INCHES OF WATER EQUIVALENT ACROSS THE ADIRONDACKS AND GREEN
MOUNTAINS. ALTHOUGH NOT MODELED...SOME SMALL AMOUNTS OF SNOW ARE
STILL PROBABLY IN PLACE ACROSS THE HIGHEST ELEVATIONS OF THE
BERKSHIRES...AND HIGH PEAKS OF THE CATSKILLS IN GREENE AND ULSTER
COUNTIES. WARM TEMPERATURES DURING THE DAYTIME HOURS OVER THE NEXT
SEVERAL DAYS...ESPECIALLY THIS WEEKEND...WILL ALLOW FOR CONTINUED
SNOW MELT...ALTHOUGH RATES SHOULD SLOW DOWN AT NIGHT WITH
TEMPERATURES DROPPING INTO THE 30S TO LOW 40S ACROSS THE HIGH
TERRAIN. BECAUSE OF THIS GRADUAL MELTING...AND NO HEAVY
PRECIPITATION EXPECTED ANYTIME SOON...NO RIVER PROBLEMS ARE
ANTICIPATED...AND THE SHORT-TERM HYDROLOGIC ENSEMBLE SHOWS NO RIVERS
IN OUR AREA EVEN REACHING ACTION STAGE OVER THE NEXT SEVERAL DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...FRUGIS/HWJIV
LONG TERM...BGM
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
550 AM EDT THU MAR 15 2012
.SYNOPSIS...
A WEAK DISTURBANCE WILL BRING SCATTERED SHOWERS AND PERHAPS A RUMBLE
OF THUNDER FROM ALBANY NORTH AND WEST EARLY IN THE MORNING. THEN
AFTER A BREAK IN THE ACTION...A STRONGER DISTURBANCE...LINKED WITH A
MID LEVEL WARM FRONT...WILL BRING A BETTER CHANCE OF SHOWERS AND
ANOTHER THUNDERSTORM LATER TONIGHT INTO FRIDAY. HIGH PRESSURE WILL
SLOWLY BUILD IN FRIDAY NIGHT INTO SATURDAY BRING DRIER CONDITIONS
ALONG WITH VERY MILD TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 530 AM...SHOWERS AND ISOLATED THUNDERSTORMS MOVING QUICKLY
INTO THE MOHAWK VALLEY. THE 06Z NAM HAD ABSOLUTELY NO EVIDENCE OF
THEM ON THE PLANAR VIEW. THE LATEST HRRR AND RUC HAD FORECASTED SOME
ACTIVITY BUT IN THE WRONG PLACES AND WRONG TIMES.
THIS SHORT-WAVE...POORLY FORECASTED BY THE MODELS...HAS BEEN
RE-TOOLED IN GFE. WE ARE THINKING IT WILL WEAKEN AS IT MOVES AWAY
FROM ITS THETA-E SOURCE BUT STILL CARRY ISOLATED ACTIVITY PAST THE
GREATER CAPITAL DISTRICT THROUGH AT LEAST EARLY MORNING. THIS
ACTIVITY NOW STRETCHES BACK BEYOND LAKE ONTARIO SO WE MIGHT HAVE TO
EXTEND IT EVEN FURTHER INTO THE MORNING.
TEMPERATURES THIS MORNING WERE GENERALLY COLDER THIS MORNING THAN
PAST MORNING...AND IN SOME CASES...BELOW FREEZING (LIKE GLENS
FALLS). CONCERN IS THAT WITH SHOWERS MOVING INTO THESE REGIONS THERE
IS A REMOTE POSSIBILITY THAT FREEZING RAIN COULD FALL. WE WILL
MONITOR AND ISSUE MORE SPECIAL WEATHER STATEMENTS AS NEEDED.
AFTER THE DISTURBANCE MOVES THROUGH LATER THIS MORNING...IT LOOKS
DRY THROUGH MUCH OF THE AFTERNOON. HOWEVER... A STRONGER DISTURBANCE
EVIDENT ON THE H20 LP OVER THE NORTHWESTERN GREAT LAKES WILL HEAD
TOWARD OUR REGION...BUT NOT UNTIL VERY LATE IN THE DAY OR MORE
LIKELY...EVENING.
THE 11U-3.9U INDICATES THE STRATUS HAS NOT MADE MUCH PROGRESS
NORTHWARD OF LONG ISLAND WHILE AC AHEAD OF THE SHOWERS AND
THUNDERSTORMS WERE WORKING ACROSS THE MOHAWK VALLEY.
ONCE CLOUDS ASSOCIATED WITH THE DISTURBANCE MOVES ON BY TO OUR
SOUTHEAST LATER TODAY...SOME SUNSHINE IS EXPECTED BEFORE CLOUDS TEND
TO INCREASE LATER THIS MORNING BEFORE THE NEXT BATCH OF CLOUDS ROLL
IN.
WE EXPECT HIGH TEMPERATURES SOMEWHAT SIMILAR TO WEDNESDAY/S
GENERALLY IN THE 50S. THE MID HUDSON VALLEY AND LOWER LITCHFIELD
AREA WILL BE COOLER THAN YESTERDAY AS THE WIND FLOW WILL BE
SOUTHEAST...SO THEREFORE NO BENEFICIAL DOWNSLOPE WILL ENSUE OFF THE
CATSKILLS...TOPPING OUT AROUND 60.
ONCE AGAIN HOWEVER...THESE VALUES WILL BE RUNNING AT LEAST 10
DEGREES ABOVE NORMAL FOR MID MARCH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT INTO FRIDAY AFTERNOON...THE AFOREMENTIONED SHORTWAVE ALONG
WITH IT/S WEAK SFC LOW REFLECTION WILL BE MOVING FROM THE GREAT
LAKES SOUTHEASTWARD TOWARDS UPSTATE NY. THIS WILL ALLOW FOR LIKELY
SHOWERS AND THE CHANCE OF THUNDERSTORMS ACROSS OUR AREA...MAINLY
OVERNIGHT. SHOWALTER VALUES CONTINUE SLIGHTLY NEGATIVE...AND MIXED
LAYER MUCAPE VALUES RANGE BETWEEN 0 AND 400 J/KG. WHILE THERE MAY BE
A FEW RUMBLES OF THUNDER AROUND...AND 850-500 HPA LAPSE RATES WILL
BE AROUND 6.5 DEGREES C/KM...IT/S UNLIKELY ANY STORM WOULD BECOME
STRONG DUE TO THE RELATIVELY LOW DEWPOINT TEMPS AND MEAGER CAPE.
OVERNIGHT LOW TEMPERATURES WILL WITH THE CLOUDS AND ANTICIPATED
SHOWER ACTIVITY...OVERNIGHT LOWS WILL BE MILD TONIGHT...WITH MOST
AREAS IN THE UPPER 30S TO MID 40S. TEMPERATURES ON FRIDAY WILL BE A
LITTLE COOLER THAN RECENT DAYS...BUT STILL MILD FOR THIS TIME OF
YEAR...MAINLY IN THE MID OR UPPER 50S. (A FEW READINGS AROUND 60 IN
THE MID HUDSON VALLEY).
BY FRIDAY EVENING...THE DISTURBANCE WILL BE PASSING EAST OF THE
REGION AND A DRYING TREND WILL SET IN. AN UPPER LEVEL RIDGE OVER THE
MIDWEST WILL BUILD INTO THE AREA FOR THE OVERNIGHT
HOURS...ALLOWING THE THREAT FOR SHOWERS TO END. A SURFACE HIGH WILL
BUILDING SOUTHWARD FROM CANADA. THIS SETUP USUALLY POSES A CHALLENGE
TO HOW QUICKLY WE CLEAR OUT...AS MOISTURE COULD EASILY GET TRAPPED
UNDERNEATH AN LOWERING INVERSION. THUS FAR...MODELS ARE OPTIMISTIC
THAT CLOUDS WILL AT LEAST THIN. HOWEVER IF THEY DO...CHANCES FOR FOG
WILL INCREASE. FOR NOW...WENT PARTLY CLOUDY WITH PATCHY FOG.
ASSUMING THIS MIDDLE OF THE ROAD SCENARIO...TEMPERATURES WILL DIP TO
THE MID 30S TO LOWER 40S. IF CLOUDS WERE TO PERSIST...OVERNIGHT LOWS
WOULD BE A LITTLE MILDER. ON THE OTHER HAND...IF WE WERE TO CLEAR
MORE QUICKLY...READINGS COULD DIP A BIT LOWER...ALLOWING MORE
EXTENSIVE FOG TO POSSIBLY FORM.
SATURDAY...HIGH TEMPERATURES WILL TRICKY TO FORECAST. WE ASSUME A
GOOD DEAL OF SUNSHINE. HOWEVER...THE MEAN AIR FLOW WILL BE SSE (AS
OPPOSED TO SSW) SO THERE COULD BE LINGERING MARINE INFLUENCES. THE
MET GUIDANCE (OFF THE NAM MODEL) INDICATED TEMPERATURES ONLY
REACHING THE 50S ON SATURDAY WHILE THE MAV GUIDANCE (BASED OFF THE
GFS MODEL) INDICATE MUCH WARMER READINGS WELL INTO THE 60S...SOME 15
DEGREES HIGHER THAN THE METS IN SOME CASES.
IF LOW CLOUDS WERE TO BACK IN (OR NEVER BURN OFF) THE MET VALUES
WOULD BE MORE CORRECT. HOWEVER...SINCE WE ARE BANKING ON MORE
SUNSHINE...LEANED WITH (BUT NOT QUITE ALL THE WAY) THE WARMER MAV
GUIDANCE. THIS WOULD TRANSLATE TO HIGHS MAINLY IN THE 60S ON
SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
WHILE CONFIDENCE REMAINS ABOVE NORMAL FOR UNSEASONABLY MILD
TEMPERATURES DURING THIS LONG TERM PERIOD OF THE FORECAST...AS
DISCUSSED THIS TIME YESTERDAY...THERE REMAINS CAVEATS THAT COULD
DISRUPT TRANQUIL CONDITIONS.
LATEST GLOBAL MODEL TRENDS CONTINUE TO SUPPORT A TRANQUIL END TO THE
WEEKEND AS BOTH THE SURFACE RIDGE AND POSITIVE HEIGHT ANOMALIES
ALOFT ARE EXPECTED TO BE OVER THE MID ATLANTIC AND NORTHEAST.
THEREAFTER...WE TURN UPSTREAM AS THE COMBINATION OF INCREASED
INSTABILITY AND SHORT WAVE TIMING BECOME INCREASINGLY MORE
PROBLEMATIC.
GFS/ECMWF ARE IN SOME AGREEMENT WITH AN MCS-LIKE FEATURE DEVELOPING
OVER THE MID MISSISSIPPI RIVER VALLEY DURING THIS WEEKEND. THIS MCV
PROPAGATES NORTHWARD ALONG THE BACKSIDE OF THIS DEVELOPING RIDGE
AXIS ALONG THE EASTERN SEABOARD. THIS MCV ATTEMPTS TO FIND A
WEAKNESS IN THE RIDGE AND MOVES ACROSS THE REGION LATE SUNDAY INTO
MONDAY. THIS MAY DISRUPT THE FULL INSOLATION AND KEEP TEMPERATURES
DOWN A LITTLE THAN PREVIOUS FORECASTS ALONG WITH A RENEWED CHANCE
FOR CONVECTION.
BOTH THE GFS AND ECMWF NOW SUGGEST MOISTURE BECOMES TRAPPED UNDER
THOSE INCREASING HEIGHTS ALOFT FOR MORE CLOUD COVER. AS 850MB TEMPS
CLIMB AT OR ABOVE 10C...EVEN WITH THE CLOUDS...WE SHOULD BE ABLE TO
CLIMB INTO THE LOWER HALF OF THE 70S FOR VALLEY LOCATIONS AND 60S
FOR THE HIGHER TERRAIN.
THE BEST CHANCE FOR PORTIONS OF THE REGION TO PERHAPS TOUCH THE 80
DEGREE MARK DOES APPEAR TO BE ON WEDNESDAY WITH NEAR +12C AND AN
INCREASE SOUTHERLY FLOW.
AS FOR RECORDS DURING THIS PERIOD...HERE ARE ALBANY STATS...
DATE TEMP YEAR
SUN MAR 18 65 1966
MON MAR 19 75 1894
TUE MAR 20 74 1903
WED MAR 21 78 1921
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
EXTREMELY CHALLENGING FORECAST OVERNIGHT INTO THURSDAY. LATEST
SATELLITE IMAGERY REVEALS A LOWERING STRATUS DECK TO OUR EAST THAT
IS ATTEMPTING BACK-BUILD INTO EASTERN NEW YORK. IN
ADDITION...CONVECTION HAS DEVELOPED NORTH OF LAKE ONTARIO THAT IS
WEAKENING WITH ITS FAST FORWARD SOUTHEAST PROPAGATION. GUIDANCE
NOT DOING WELL WITH RESPECT THE LOWER STRATUS DECK AS THE NAM
OFFERS AT LEAST HINTS OF THE EXPECTATIONS. AT THIS TIME...THE
HIGHER CHANCE FOR IFR CONDITIONS APPEARS TO BE AT KPOU AND KGFL
WHERE WE WILL PLACE TEMPO GROUPS AT THIS TIME AND CLOSELY MONITOR
TRENDS. KALB APPEARS TO BE OKAY WITH JUST AN INCREASE IN THE AC
DECK OVERNIGHT.
DURING THURSDAY...CLOUDS WILL THICKEN AND LOWER ALONG WITH THE
CHANCE FOR SHOWERS /MAINLY NORTH OF KPOU/. WE WILL PLACE A
DOMINATE MVFR CATEGORY WITH CIGS AND PLACE A VCSH DUE TO
CONFIDENCE LEVELS AT THE PRESENT TIME.
NORTH-NORTHWEST WINDS AT LESS THAN 10 KT THIS EARLY MORNING...THEN
SOUTHEAST TO SOUTH AT LESS THAN 10 KT THURSDAY DAYLIGHT HOURS.
OUTLOOK...
THU NIGHT...MVFR/IFR...-SHRA LIKELY. ISOLD -TSRA.
FRI-FRI NIGHT...MVFR...SCT-NUMEROUS -SHRA AND ISOLD -TSRA EARLY.
SAT-SUN...VFR. NO SIG WX.
SUN NIGHT-MON...MAINLY VFR. SLIGHT CHC -SHRA/-TSRA.
&&
.FIRE WEATHER...
RH VALUES WILL REMAIN HIGHER THAN YESTERDAY...BOTTOMING IN THE
MODERATE RANGE (40-60 PERCENT). 10 METER WINDS WILL BE SOUTH OR
SOUTHEAST GENERALLY AROUND 10 MPH OR LESS. THERE WILL ISOLATED
SHOWERS AND POSSIBLY A THUNDERSTORM THIS MORNING AND POSSIBLY BY
LATE IN THE DAY. MOST OF THE DAY WILL BE RAINFREE AND ANY RAINFALL
WILL AVERAGE WELL BELOW A QUARTER OF AN INCH.
THERE WILL BE MORE CLOUDS THAN WEDNESDAY BUT ALSO TIMES OF
SUNSHINE...ESPECIALLY MIDDAY.
SHOWERS WILL BECOME MORE LIKELY LATER TONIGHT AND FRIDAY AS A
DISTURBANCE AND ELEVATED WARM FRONT MOVE ACROSS THE REGION. A
QUARTER OF AN INCH OF RAIN OR MORE IS POSSIBLE...ESPECIALLY NORTH
AND WEST OF ALBANY. RH LEVELS WILL REMAIN ELEVATED ON FRIDAY
(GENERALLY HIGHER THAN 60 PERCENT).
DRY WEATHER RETURNS FRIDAY NIGHT INTO THE WEEKEND. IT WILL BECOME
UNSEASONABLY WARM WITH SOME SUNSHINE EXPECTED BOTH WEEKEND DAYS.
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE NEXT MONDAY.
&&
.HYDROLOGY...
NO HYDROLOGIC ISSUES ARE ANTICIPATED OVER THE NEXT 5 DAYS.
ISOLATED SHOWERS AND THUNDERSTORMS SHOULD HAVE NO EFFECT ON RUNOFF.
IN FACT...IN SOME CASES THE PRECIPITATION MIGHT FALL AS FREEZING
RAIN (ALBEIT VERY LIGHT).
MORE SHOWER ACTIVITY IS LIKELY TONIGHT INTO EARLY FRIDAY. AT THIS
POINT RAINFALL AMOUNTS LOOK FAIRLY LIGHT...PERHAPS APPROACHING HALF
AN INCH IN OUR NORTHWESTERN ZONES...BUT GENERALLY AROUND A QUARTER
OF AN INCH OR LESS THROUGH THE REMAINDER OF OUR HYDROLOGICAL
FORECAST AREA.
THIS RAINFALL COULD PRODUCE WELL WITHIN BANK RISES ON SOME STREAMS
AND RIVERS...ESPECIALLY THOSE NORTHWEST OF ALBANY.
THE LATEST NOHRSC MODELED SNOW COVERAGE CONTINUES TO SHOW SEVERAL
INCHES OF WATER EQUIVALENT ACROSS THE ADIRONDACKS AND GREEN
MOUNTAINS. ALTHOUGH NOT MODELED...SOME SMALL AMOUNTS OF SNOW ARE
STILL PROBABLY IN PLACE ACROSS THE HIGHEST ELEVATIONS OF THE
BERKSHIRES...AND HIGH PEAKS OF THE CATSKILLS IN GREENE AND ULSTER
COUNTIES. WARM TEMPERATURES DURING THE DAYTIME HOURS OVER THE NEXT
SEVERAL DAYS...ESPECIALLY THIS WEEKEND...WILL ALLOW FOR CONTINUED
SNOW MELT...ALTHOUGH RATES SHOULD SLOW DOWN AT NIGHT WITH
TEMPERATURES DROPPING INTO THE 30S TO LOW 40S ACROSS THE HIGH
TERRAIN. BECAUSE OF THIS GRADUAL MELTING...AND NO HEAVY
PRECIPITATION EXPECTED ANYTIME SOON...NO RIVER PROBLEMS ARE
ANTICIPATED...AND THE SHORT-TERM HYDROLOGIC ENSEMBLE SHOWS NO RIVERS
IN OUR AREA EVEN REACHING ACTION STAGE OVER THE NEXT SEVERAL DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...FRUGIS/HWJIV
LONG TERM...BGM
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
530 AM EDT THU MAR 15 2012
.SYNOPSIS...
A WEAK DISTURBANCE WILL BRING ISOLATED SHOWERS AND PERHAPS A
THUNDERSTORM TO AREAS MAINLY NORTH AND WEST OF ALBANY THIS MORNING.
THEN AFTER A BREAK IN THE ACTION...A STRONGER DISTURBANCE...LINKED
WITH A MID LEVEL WARM FRONT...WILL BRING A BETTER CHANCE OF SHOWERS
AND ANOTHER THUNDERSTORM LATER TONIGHT INTO FRIDAY. HIGH PRESSURE
WILL SLOWLY BUILD IN FRIDAY NIGHT INTO SATURDAY BRING DRIER
CONDITIONS ALONG WITH VERY MILD TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 530 AM...SHOWERS AND ISOLATED THUNDERSTORMS MOVING QUICKLY
INTO THE MOHAWK VALLEY. THE 06Z NAM HAD ABSOLUTELY NO EVIDENCE OF
THEM ON THE PLANAR VIEW. THE LATEST HRRR AND RUC HAD FORECASTED SOME
ACTIVITY BUT IN THE WRONG PLACES AND WRONG TIMES.
THIS SHORT-WAVE...POORLY FORECASTED BY THE MODELS...HAS BEEN
RE-TOOLED IN GFE. WE ARE THINKING IT WILL WEAKEN AS IT MOVES AWAY
FROM ITS THETA-E SOURCE BUT STILL CARRY ISOLATED ACTIVITY PAST THE
GREATER CAPITAL DISTRICT THROUGH AT LEAST EARLY MORNING. THIS
ACTIVITY NOW STRETCHES BACK BEYOND LAKE ONTARIO SO WE MIGHT HAVE TO
EXTEND IT EVEN FURTHER INTO THE MORNING.
TEMPERATURES THIS MORNING WERE GENERALLY COLDER THIS MORNING THAN
PAST MORNING...AND IN SOME CASES...BELOW FREEZING (LIKE GLENS
FALLS). CONCERN IS THAT WITH SHOWERS MOVING INTO THESE REGIONS THERE
IS A REMOTE POSSIBILITY THAT FREEZING RAIN COULD FALL. WE WILL
MONITOR AND ISSUE MORE SPECIAL WEATHER STATEMENTS AS NEEDED.
AFTER THE DISTURBANCE MOVES THROUGH LATER THIS MORNING...IT LOOKS
DRY THROUGH MUCH OF THE AFTERNOON. HOWEVER... A STRONGER DISTURBANCE
EVIDENT ON THE H20 LP OVER THE NORTHWESTERN GREAT LAKES WILL HEAD
TOWARD OUR REGION...BUT NOT UNTIL VERY LATE IN THE DAY OR MORE
LIKELY...EVENING.
THE 11U-3.9U INDICATES THE STRATUS HAS NOT MADE MUCH PROGRESS
NORTHWARD OF LONG ISLAND WHILE AC AHEAD OF THE SHOWERS AND
THUNDERSTORMS WERE WORKING ACROSS THE MOHAWK VALLEY.
ONCE CLOUDS ASSOCIATED WITH THE DISTURBANCE MOVES ON BY TO OUR
SOUTHEAST LATER TODAY...SOME SUNSHINE IS EXPECTED BEFORE CLOUDS TEND
TO INCREASE LATER THIS MORNING BEFORE THE NEXT BATCH OF CLOUDS ROLL
IN.
WE EXPECT HIGH TEMPERATURES SOMEWHAT SIMILAR TO WEDNESDAY/S
GENERALLY IN THE 50S. THE MID HUDSON VALLEY AND LOWER LITCHFIELD
AREA WILL BE COOLER THAN YESTERDAY AS THE WIND FLOW WILL BE
SOUTHEAST...SO THEREFORE NO BENEFICIAL DOWNSLOPE WILL ENSUE OFF THE
CATSKILLS...TOPPING OUT AROUND 60.
ONCE AGAIN HOWEVER...THESE VALUES WILL BE RUNNING AT LEAST 10
DEGREES ABOVE NORMAL FOR MID MARCH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT INTO FRIDAY AFTERNOON...THE AFOREMENTIONED SHORTWAVE ALONG
WITH IT/S WEAK SFC LOW REFLECTION WILL BE MOVING FROM THE GREAT
LAKES SOUTHEASTWARD TOWARDS UPSTATE NY. THIS WILL ALLOW FOR LIKELY
SHOWERS AND THE CHANCE OF THUNDERSTORMS ACROSS OUR AREA...MAINLY
OVERNIGHT. SHOWALTER VALUES CONTINUE SLIGHTLY NEGATIVE...AND MIXED
LAYER MUCAPE VALUES RANGE BETWEEN 0 AND 400 J/KG. WHILE THERE MAY BE
A FEW RUMBLES OF THUNDER AROUND...AND 850-500 HPA LAPSE RATES WILL
BE AROUND 6.5 DEGREES C/KM...IT/S UNLIKELY ANY STORM WOULD BECOME
STRONG DUE TO THE RELATIVELY LOW DEWPOINT TEMPS AND MEAGER CAPE.
OVERNIGHT LOW TEMPERATURES WILL WITH THE CLOUDS AND ANTICIPATED
SHOWER ACTIVITY...OVERNIGHT LOWS WILL BE MILD TONIGHT...WITH MOST
AREAS IN THE UPPER 30S TO MID 40S. TEMPERATURES ON FRIDAY WILL BE A
LITTLE COOLER THAN RECENT DAYS...BUT STILL MILD FOR THIS TIME OF
YEAR...MAINLY IN THE MID OR UPPER 50S. (A FEW READINGS AROUND 60 IN
THE MID HUDSON VALLEY).
BY FRIDAY EVENING...THE DISTURBANCE WILL BE PASSING EAST OF THE
REGION AND A DRYING TREND WILL SET IN. AN UPPER LEVEL RIDGE OVER THE
MIDWEST WILL BUILD INTO THE AREA FOR THE OVERNIGHT
HOURS...ALLOWING THE THREAT FOR SHOWERS TO END. A SURFACE HIGH WILL
BUILDING SOUTHWARD FROM CANADA. THIS SETUP USUALLY POSES A CHALLENGE
TO HOW QUICKLY WE CLEAR OUT...AS MOISTURE COULD EASILY GET TRAPPED
UNDERNEATH AN LOWERING INVERSION. THUS FAR...MODELS ARE OPTIMISTIC
THAT CLOUDS WILL AT LEAST THIN. HOWEVER IF THEY DO...CHANCES FOR FOG
WILL INCREASE. FOR NOW...WENT PARTLY CLOUDY WITH PATCHY FOG.
ASSUMING THIS MIDDLE OF THE ROAD SCENARIO...TEMPERATURES WILL DIP TO
THE MID 30S TO LOWER 40S. IF CLOUDS WERE TO PERSIST...OVERNIGHT LOWS
WOULD BE A LITTLE MILDER. ON THE OTHER HAND...IF WE WERE TO CLEAR
MORE QUICKLY...READINGS COULD DIP A BIT LOWER...ALLOWING MORE
EXTENSIVE FOG TO POSSIBLY FORM.
SATURDAY...HIGH TEMPERATURES WILL TRICKY TO FORECAST. WE ASSUME A
GOOD DEAL OF SUNSHINE. HOWEVER...THE MEAN AIR FLOW WILL BE SSE (AS
OPPOSED TO SSW) SO THERE COULD BE LINGERING MARINE INFLUENCES. THE
MET GUIDANCE (OFF THE NAM MODEL) INDICATED TEMPERATURES ONLY
REACHING THE 50S ON SATURDAY WHILE THE MAV GUIDANCE (BASED OFF THE
GFS MODEL) INDICATE MUCH WARMER READINGS WELL INTO THE 60S...SOME 15
DEGREES HIGHER THAN THE METS IN SOME CASES.
IF LOW CLOUDS WERE TO BACK IN (OR NEVER BURN OFF) THE MET VALUES
WOULD BE MORE CORRECT. HOWEVER...SINCE WE ARE BANKING ON MORE
SUNSHINE...LEANED WITH (BUT NOT QUITE ALL THE WAY) THE WARMER MAV
GUIDANCE. THIS WOULD TRANSLATE TO HIGHS MAINLY IN THE 60S ON
SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
WHILE CONFIDENCE REMAINS ABOVE NORMAL FOR UNSEASONABLY MILD
TEMPERATURES DURING THIS LONG TERM PERIOD OF THE FORECAST...AS
DISCUSSED THIS TIME YESTERDAY...THERE REMAINS CAVEATS THAT COULD
DISRUPT TRANQUIL CONDITIONS.
LATEST GLOBAL MODEL TRENDS CONTINUE TO SUPPORT A TRANQUIL END TO THE
WEEKEND AS BOTH THE SURFACE RIDGE AND POSITIVE HEIGHT ANOMALIES
ALOFT ARE EXPECTED TO BE OVER THE MID ATLANTIC AND NORTHEAST.
THEREAFTER...WE TURN UPSTREAM AS THE COMBINATION OF INCREASED
INSTABILITY AND SHORT WAVE TIMING BECOME INCREASINGLY MORE
PROBLEMATIC.
GFS/ECMWF ARE IN SOME AGREEMENT WITH AN MCS-LIKE FEATURE DEVELOPING
OVER THE MID MISSISSIPPI RIVER VALLEY DURING THIS WEEKEND. THIS MCV
PROPAGATES NORTHWARD ALONG THE BACKSIDE OF THIS DEVELOPING RIDGE
AXIS ALONG THE EASTERN SEABOARD. THIS MCV ATTEMPTS TO FIND A
WEAKNESS IN THE RIDGE AND MOVES ACROSS THE REGION LATE SUNDAY INTO
MONDAY. THIS MAY DISRUPT THE FULL INSOLATION AND KEEP TEMPERATURES
DOWN A LITTLE THAN PREVIOUS FORECASTS ALONG WITH A RENEWED CHANCE
FOR CONVECTION.
BOTH THE GFS AND ECMWF NOW SUGGEST MOISTURE BECOMES TRAPPED UNDER
THOSE INCREASING HEIGHTS ALOFT FOR MORE CLOUD COVER. AS 850MB TEMPS
CLIMB AT OR ABOVE 10C...EVEN WITH THE CLOUDS...WE SHOULD BE ABLE TO
CLIMB INTO THE LOWER HALF OF THE 70S FOR VALLEY LOCATIONS AND 60S
FOR THE HIGHER TERRAIN.
THE BEST CHANCE FOR PORTIONS OF THE REGION TO PERHAPS TOUCH THE 80
DEGREE MARK DOES APPEAR TO BE ON WEDNESDAY WITH NEAR +12C AND AN
INCREASE SOUTHERLY FLOW.
AS FOR RECORDS DURING THIS PERIOD...HERE ARE ALBANY STATS...
DATE TEMP YEAR
SUN MAR 18 65 1966
MON MAR 19 75 1894
TUE MAR 20 74 1903
WED MAR 21 78 1921
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
EXTREMELY CHALLENGING FORECAST OVERNIGHT INTO THURSDAY. LATEST
SATELLITE IMAGERY REVEALS A LOWERING STRATUS DECK TO OUR EAST THAT
IS ATTEMPTING BACK-BUILD INTO EASTERN NEW YORK. IN
ADDITION...CONVECTION HAS DEVELOPED NORTH OF LAKE ONTARIO THAT IS
WEAKENING WITH ITS FAST FORWARD SOUTHEAST PROPAGATION. GUIDANCE
NOT DOING WELL WITH RESPECT THE LOWER STRATUS DECK AS THE NAM
OFFERS AT LEAST HINTS OF THE EXPECTATIONS. AT THIS TIME...THE
HIGHER CHANCE FOR IFR CONDITIONS APPEARS TO BE AT KPOU AND KGFL
WHERE WE WILL PLACE TEMPO GROUPS AT THIS TIME AND CLOSELY MONITOR
TRENDS. KALB APPEARS TO BE OKAY WITH JUST AN INCREASE IN THE AC
DECK OVERNIGHT.
DURING THURSDAY...CLOUDS WILL THICKEN AND LOWER ALONG WITH THE
CHANCE FOR SHOWERS /MAINLY NORTH OF KPOU/. WE WILL PLACE A
DOMINATE MVFR CATEGORY WITH CIGS AND PLACE A VCSH DUE TO
CONFIDENCE LEVELS AT THE PRESENT TIME.
NORTH-NORTHWEST WINDS AT LESS THAN 10 KT THIS EARLY MORNING...THEN
SOUTHEAST TO SOUTH AT LESS THAN 10 KT THURSDAY DAYLIGHT HOURS.
OUTLOOK...
THU NIGHT...MVFR/IFR...-SHRA LIKELY. ISOLD -TSRA.
FRI-FRI NIGHT...MVFR...SCT-NUMEROUS -SHRA AND ISOLD -TSRA EARLY.
SAT-SUN...VFR. NO SIG WX.
SUN NIGHT-MON...MAINLY VFR. SLIGHT CHC -SHRA/-TSRA.
&&
.FIRE WEATHER...
RH VALUES WILL REMAIN HIGHER THAN YESTERDAY...BOTTOMING IN THE
MODERATE RANGE (40-60 PERCENT). 10 METER WINDS WILL BE SOUTH OR
SOUTHEAST GENERALLY AROUND 10 MPH OR LESS. THERE WILL ISOLATED
SHOWERS AND POSSIBLY A THUNDERSTORM THIS MORNING AND POSSIBLY BY
LATE IN THE DAY. MOST OF THE DAY WILL BE RAINFREE AND ANY RAINFALL
WILL AVERAGE WELL BELOW A QUARTER OF AN INCH.
THERE WILL BE MORE CLOUDS THAN WEDNESDAY BUT ALSO TIMES OF
SUNSHINE...ESPECIALLY MIDDAY.
SHOWERS WILL BECOME MORE LIKELY LATER TONIGHT AND FRIDAY AS A
DISTURBANCE AND ELEVATED WARM FRONT MOVE ACROSS THE REGION. A
QUARTER OF AN INCH OF RAIN OR MORE IS POSSIBLE...ESPECIALLY NORTH
AND WEST OF ALBANY. RH LEVELS WILL REMAIN ELEVATED ON FRIDAY
(GENERALLY HIGHER THAN 60 PERCENT).
DRY WEATHER RETURNS FRIDAY NIGHT INTO THE WEEKEND. IT WILL BECOME
UNSEASONABLY WARM WITH SOME SUNSHINE EXPECTED BOTH WEEKEND DAYS.
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE NEXT MONDAY.
&&
.HYDROLOGY...
NO HYDROLOGIC ISSUES ARE ANTICIPATED OVER THE NEXT 5 DAYS.
ISOLATED SHOWERS AND THUNDERSTORMS SHOULD HAVE NO EFFECT ON RUNOFF.
IN FACT...IN SOME CASES THE PRECIPITATION MIGHT FALL AS FREEZING
RAIN (ALBEIT VERY LIGHT).
MORE SHOWER ACTIVITY IS LIKELY TONIGHT INTO EARLY FRIDAY. AT THIS
POINT RAINFALL AMOUNTS LOOK FAIRLY LIGHT...PERHAPS APPROACHING HALF
AN INCH IN OUR NORTHWESTERN ZONES...BUT GENERALLY AROUND A QUARTER
OF AN INCH OR LESS THROUGH THE REMAINDER OF OUR HYDROLOGICAL
FORECAST AREA.
THIS RAINFALL COULD PRODUCE WELL WITHIN BANK RISES ON SOME STREAMS
AND RIVERS...ESPECIALLY THOSE NORTHWEST OF ALBANY.
THE LATEST NOHRSC MODELED SNOW COVERAGE CONTINUES TO SHOW SEVERAL
INCHES OF WATER EQUIVALENT ACROSS THE ADIRONDACKS AND GREEN
MOUNTAINS. ALTHOUGH NOT MODELED...SOME SMALL AMOUNTS OF SNOW ARE
STILL PROBABLY IN PLACE ACROSS THE HIGHEST ELEVATIONS OF THE
BERKSHIRES...AND HIGH PEAKS OF THE CATSKILLS IN GREENE AND ULSTER
COUNTIES. WARM TEMPERATURES DURING THE DAYTIME HOURS OVER THE NEXT
SEVERAL DAYS...ESPECIALLY THIS WEEKEND...WILL ALLOW FOR CONTINUED
SNOW MELT...ALTHOUGH RATES SHOULD SLOW DOWN AT NIGHT WITH
TEMPERATURES DROPPING INTO THE 30S TO LOW 40S ACROSS THE HIGH
TERRAIN. BECAUSE OF THIS GRADUAL MELTING...AND NO HEAVY
PRECIPITATION EXPECTED ANYTIME SOON...NO RIVER PROBLEMS ARE
ANTICIPATED...AND THE SHORT-TERM HYDROLOGIC ENSEMBLE SHOWS NO RIVERS
IN OUR AREA EVEN REACHING ACTION STAGE OVER THE NEXT SEVERAL DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...FRUGIS/HWJIV
LONG TERM...BGM
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
315 PM EDT THU MAR 15 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER NORTHERN NEW ENGLAND AND THE CANADIAN
MARITIMES WILL GRADUALLY WEAKEN AND SHIFT EASTWARD THROUGH FRIDAY.
A WEAKENING COLD FRONT WILL CROSS OUR AREA LATE FRIDAY, WITH HIGH
PRESSURE BUILDING IN DURING SATURDAY. THIS AREA OF HIGH PRESSURE
THEN BECOMES ANCHORED ALONG AND EAST OF THE MID ATLANTIC COAST
SUNDAY THROUGH THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
WE HAVE TO LOOK BOTH WAYS BEFORE CROSSING THE METEOROLOGICAL STREET
TODAY AS AT LEAST FOR ONE DAY MARCH ACTED MORE LIKE MARCH AND NOT
MAY. WITH REGARDS TO THE LOW CLOUDINESS, WE FOLLOWED THE HRRR AND
RUC13 FORECAST LOW LEVEL MOISTURE THAT WAS VERIFYING THE BEST TO
SPREAD AND DEVELOP THE LOW CLOUDS WESTWARD AS THE REST OF THE
AFTERNOON AND EVENING PROGRESSES. GIVEN THE SUBTLE SHIFT IN THE
ONSHORE FLOW, THIS WOULD FAVOR A FASTER EXPANSION IN THE NORTHERN
TWO THIRDS OF OUR CWA. UPWIND LAND OBSERVATIONS ARE SHOWING MORE
STRATUS THAN FOG AND FOR NOW WE DID NOT INCLUDE ANY FOG IN THE
GRIDS. UPWIND DEW POINTS ARE LOWER THAN WATER TEMPS, BUT NOT AS SURE
ABOUT THIS BEING THE CASE OVERNIGHT.
AS FOR PCPN CHANCES TONIGHT, COULD NOT FIND A MODEL THAT WAS
HANDLING THE ONGOING CONVECTION WELL, EVEN OUR HIGH RES VERSIONS. SO
WE TRIED TO INFER THE THOUGHT PROCESS OF TSRAS DEVELOPING IN THE
MORE UNSTABLE AIR TO OUR WEST OR NORTHWEST AND MAKING THEIR WAY INTO
OUR CWA OVERNIGHT. THERE WERE MORE SHORT WAVES NORTH THAN SOUTH
FORECAST, SO HIGHEST POPS WERE GENERALLY NORTH OF I195 IN NEW JERSEY
AND NORTHWEST OF I95 ELSEWHERE. AS FOR THUNDER POSSIBILITIES, WHILE
IT IS FORECAST UNSTABLE ENOUGH FOR THEM ALOFT, DO NOT SEE ANY STRONG
SHORT WAVES OR VIGOROUS FCST ISENTROPIC LIFT TO WARRANT A MENTION
BEYOND ISOLATED. WHILE WE ARE NOT CARRYING IT TO SIMPLIFY THE
WORDING A BIT FOR TONIGHT, THE POSSIBILITY OF DRIZZLE OCCURRING IN
ADDITION TO OTHER PTYPES IS STILL THERE.
GIVEN THAT TEMPERATURES OVERALL ARE OFF TO A MUCH COOLER START THAN
EITHER WE OR STAT GUIDANCE ANTICIPATED EARLIER TODAY, MIN TEMPS WERE
AT OR BELOW STAT GUIDANCE FOR TNGT. A BLEND OF ACTUAL WRF-NMMB,
ECMWF SFC PROG TEMPS AND LATEST MET AND MAV GUIDANCE WAS USED. WE
TRIED TO KEEP MINS AT OR ABOVE CURRENT DEW POINTS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
ON FRIDAY THE LOW LEVEL ONSHORE FLOW IS FORECAST TO CEASE WITH A
MORE GENERAL SOUTHWEST FLOW FORECAST TO OCCUR ABOVE THE BOUNDARY
LAYER. AT THE SURFACE THIS IS COMPLICATED BY A WEAK LOW PRESSURE
SYSTEM THAT IS FORECAST TO FORM ON THE WARM FRONT SOUTH OF OUR CWA
AND AT THE LEAST WOULD SLOW THE OCCURRENCE OF SOUTHWEST WINDS AT THE
SURFACE. IN ADDITION, IT IS QUITE UNSTABLE AROUND THE GREAT LAKES
AND WOULD EXPECT MORE CONVECTION AND THUS DEBRIS FOR US TO MOVE INTO
OUR CWA. THIS ALL POINTS TO POSSIBLE PROBLEMS AT ERODING THE LOW
CLOUDS AS FRIDAY CONTINUES. THE ECMWF AND WRF-NMMB WHICH DID VERY
WELL WITH THE PREVIOUS COOL AIR DAMMING EVENT IS WARMING PA AND MD
BY THE AFTERNOON. WE ARE BANKING ON THIS ONE TO GET MAX TEMPS CLOSE
TO WHAT WE ARE CARRYING (ALTHO STILL UNDER STAT GUIDANCE) AND TWO TO
INITIATE SOME CLOSER TO HOME GROWN CONVECTION DURING THE AFTERNOON.
WE DID CARRY LIKELY POPS BANKING ON THIS AND ALSO THE PRESENCE OF
SOME WEAK FCST MID LVL QVEC CONVERGENCE AND CWA BEING IN THE
ENTRANCE REGION OF A DEVELOPING H2.5 JET. THERE ARE A TRAINLOAD OF
ASSUMPTIONS BEING MADE ABOUT FRIDAY AND THUS THE PARTICULARS AND
OVERALL OUTCOME SHOULD BE VIEWED WITH LESSER CONFIDENCE THAN AVERAGE
FOR A SECOND PERIOD FORECAST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
THE SYNOPTIC SETUP STARTS OUT WITH A WEAKENING SHORT WAVE TROUGH
MOVING ACROSS THE AREA FRIDAY NIGHT, WITH AN ASSOCIATED COLD FRONT
EXPECTED TO SETTLE SOUTH AND EAST OF THE AREA. ADDITIONAL
TROUGHING THEN TAKES PLACE IN THE WESTERN U.S. THIS WILL FORCE
DOWNSTREAM RIDGING, WHICH LOOKS TO HOLD FOR MOST OF THIS TIME FRAME.
THE SURFACE HIGH INITIALLY WILL BE SLIDING ACROSS NEW ENGLAND AND
DOWN TO THE MID ATLANTIC, AND THIS MAY ALLOW FOR SOME ADDITIONAL
COOLING TO START. A SEPARATE FRONTAL BOUNDARY DRAPED WELL TO OUR
NORTH LATE SUNDAY THROUGH WEDNESDAY SHOULD REMAIN THERE GIVEN THE
SOUTHWESTERLY FLOW AND RIDGING. THE OVERALL RIDGE THEN STRENGTHENS
IN THE EAST AS AN AMPLIFYING LARGE UPPER-LEVEL TROUGH SLOWLY EJECTS
INTO THE PLAINS. GIVEN THAT THE UPPER-LEVEL JET IS CURRENTLY DIGGING
OVER THE PACIFIC AND HOW QUICKLY THE UPPER TROUGH DEVELOPS, A CUTOFF
LOW SHOULD RESULT. THE MODEL GUIDANCE IS OFTEN TO FAST IN EJECTING
UPPER-LEVEL LOWS. GIVEN THIS TENDENCY ALONG WITH THE MAJORITY OF THE
ENSEMBLE MEMBERS SUPPORTING THE SLOWER EJECTION, HPC FAVORED A
TRANSITION TO EITHER THE GEFS MEAN OR THE ECMWF ENSEMBLE MEAN FROM
TUESDAY ONWARD TO ACCOUNT FOR THE SLOWER SOLUTION. THE INCREASING
SOUTHWESTERLY FLOW WILL ALLOW WAA TO STRENGTHEN WITH TIME, HOWEVER
WE MAY HAVE TO EVENTUALLY DEAL WITH SOME SUBTLE SHORT WAVES ON THE
WESTERN PERIPHERY OF THE RIDGE, ALTHOUGH SOME OF THESE FEATURES LOOK
TO BE CONVECTIVELY INDUCED/ENHANCED.
FOR FRIDAY NIGHT AND SATURDAY, A WEAKENING SHORT WAVE TROUGH SLIDES
THROUGH WITH AN ACCOMPANY COLD FRONT. AS A PLUME OF MOISTURE AND
SOME WEAK INSTABILITY ACCOMPANIES THESE FEATURES, A COUPLE OF
SHOWERS AND A THUNDERSTORM SHOULD BE AROUND FRIDAY EVENING BEFORE
WEAKENING AND SLIDING TO OUR SOUTH AND EAST. THE BOUNDARY LOOKS TO
SETTLE FAR ENOUGH TO OUR SOUTH AS HIGH PRESSURE BUILDS ACROSS NEW
ENGLAND INTO SATURDAY. THE ACTUAL BOUNDARY MAY THEN DISSIPATE AS
UPPER-LEVEL RIDGING BUILDS IN. THE LOW-LEVEL FLOW LOOKS LIGHT ENOUGH
ON SATURDAY WITH HIGH PRESSURE SLIDING DOWN THE COAST, THEREFORE AN
ONSHORE FLOW SHOULD DEVELOP ALLOWING FOR COOLER TEMPERATURES
ESPECIALLY ALONG THE COAST. THIS MAY ALSO TRY AND DEVELOP SOME LOW
CLOUDS FOR A TIME BEFORE THE SURFACE HIGH SLIDES FAR ENOUGH
SOUTHWARD TO SHIFT THE WINDS FROM THE SOUTH.
FOR SUNDAY AND MONDAY, THE OVERALL RIDGE IS FORECAST TO STRENGTHEN
IN THE EAST AS A STRONG UPPER-LEVEL TROUGH AMPLIFIES ACROSS THE
WEST. THIS WESTERN TROUGH WILL AIDE IN STRENGTHENING SOUTHWESTERLY
FLOW AND ALSO WAA FROM THE GULF COAST ALL THE WAY INTO THE
NORTHEAST. WHATEVER IS LEFT OF THE BOUNDARY TO OUR SOUTH SHOULD LIFT
NORTHWARD AS A WARM FRONT. THERE APPEARS TO BE SOME WEAK SHORT WAVES
TRAVERSING THE WESTERN FLANK OF THE RIDGE INTO THE OHIO VALLEY AND
INTO PARTS OF THE NORTHEAST. IF WE CAN GET ENOUGH INSTABILITY
REALIZED ALONG WITH HIGHER LOW-LEVEL MOISTURE, SOME CONVECTION MAY
ACCOMPANY THESE FEATURES. GIVEN THE FORECAST POSITION OF THE RIDGE,
THE FLOW MAY END UP BEING LIGHT ENOUGH TO FOCUS ANY CONVECTION TO
OUR WEST ALONG THE HIGHER TERRAIN. IN ADDITION, A SEA BREEZE MAY
DEVELOP BOTH AFTERNOONS.
FOR TUESDAY AND WEDNESDAY, THE TROUGH IN THE WEST EJECTS OUT ACROSS
THE PLAINS. THIS FEATURE IS FORECAST TO BECOME RATHER ROBUST AND
CLOSE OFF WITH A DEEP SOUTHERLY FLOW AHEAD OF. GIVEN THE STRENGTH OF
THIS TROUGH, STRONGER RIDGING THEN IS MAINTAINED DOWNSTREAM AND OVER
THE EAST. AGAIN THERE MAY BE TERRAIN OR SUBTLE SHORT WAVE INDUCED
CONVECTION MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS TO
OUR WEST. IF THE TIGHTER PRESSURE GRADIENT REMAINS FAR ENOUGH TO OUR
WEST, THEN PLENTY OF WARMING WOULD PROBABLY FAVOR SEA BREEZE
DEVELOPMENT EACH AFTERNOON. A FRONTAL BOUNDARY DRAPED WELL TO OUR
NORTH SHOULD REMAIN THERE GIVEN THE SOUTHERLY FLOW AND RIDGING OVER
OUR AREA.
FOR THURSDAY, A CLOSED LOW ACROSS THE PLAINS LOOKS TO SLOWLY SLIDE
EASTWARD GIVEN A LARGE RIDGE DOWNSTREAM. WE MAY HAVE TO WATCH A
FRONTAL BOUNDARY WELL TO OUR NORTH AS SOME GUIDANCE SHOWS HIGH
PRESSURE TRYING TO BUILD INTO NEW ENGLAND. THERE COULD BE ENOUGH OF
A WEAKNESS IN THE FLOW TO ALLOW A LOW-LEVEL BOUNDARY TO SLIP
SOUTHWARD AT SOME POINT. FOR NOW THOUGH, WE FAVORED THE RIDGE
/SURFACE AND ALOFT/ TO HOLD ENOUGH AND KEEP THIS LOW-LEVEL BOUNDARY
TO OUR NORTH.
AFTER FRIDAY EVENING, WE KEPT POPS UNDER SLIGHT CHC GIVEN INCREASING
UNCERTAINTY WITH ANY SUBTLE SHORT WAVES ON THE WEST SIDE OF THE
RIDGE. AS FOR TEMPERATURES, WE GENERALLY WENT WITH A MOS BLEND
FRIDAY NIGHT THROUGH SUNDAY THEN HPC GUIDANCE FROM SUNDAY NIGHT
ONWARD. SOME ADJUSTMENTS WERE MADE MAINLY CLOSER TO THE COAST DUE TO
SOME SEA BREEZE/ONSHORE POTENTIAL.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE FORECAST REMAINS A LOW CONFIDENCE ONE.
THE LOW CLOUDS EROSION PROCESS TOWARD THE COAST HAS SLOWED.
THERE WILL COME A POINT LATER THIS AFTERNOON GIVING THE CONTINUED
OCEANIC TRAJECTORY THAT THIS WILL REVERSE AND A LOW MVFR TO IFR CIG
WILL SPREAD ACROSS ALL THE TERMINALS. UNTIL THEN WE MAINTAINED SOME
MVFR TO IFR CIGS DURING THE AFTERNOON AT THE LOCAL KPHL AIRPORTS AND
KACY AND KMIV. ANY SMALLER AIRPORTS NORTHEAST OF A KACY TO KTTN LINE
SHOULD REMAIN IFR. WINDS WILL BE FROM EAST AND AVERAGE AROUND 10 KTS.
WIDESPREAD IFR CONDITIONS MAINLY DUE TO CIGS ARE FORECAST FOR
TONIGHT. THERE WILL BE SOME SHOWERS AROUND AND CAN NOT RULE OUT
DRIZZLE WITH THE ONSHORE FLOW. CONFIDENCE IS NOT HIGH ENOUGH TO
INCLUDE THE MENTION OF SHOWERS IN ANY FORECAST GROUP AT THIS TIME.
THE HIGHER RESOLUTION MODELS ARE SUGGESTING IF SHOWERS WERE TO
OCCUR AT ANY TERMINAL, IT WOULD BE FOR JUST AN HOUR OR TWO. IN
ADDITION THERE IS EVEN A LOWER PROBABILITY OF THUNDER AFFECTING
ANY TERMINALS. WINDS SHOULD BE LIGHTER FROM THE NORTHEAST TO EAST.
THE IMPROVEMENT ABOVE IFR IS EXPECTED TO BE SLOW DURING THE
MORNING ON FRIDAY AND WE BRING MOST TERMINALS UP TO MVFR LATE IN THE
MORNING. WE DID INCLUDE THE CHANCE OF THUNDER IN THE KPHL TAF FOR
FRIDAY AFTERNOON AROUND THE TIME OF MAXIMUM FORECAST INSTABILITY.
OUTLOOK...
FRIDAY NIGHT AND SATURDAY...SOME AREAS OF SUB-VFR FRIDAY NIGHT AS A
WEAK SYSTEM MOVES THROUGH WITH A COUPLE OF SHOWERS OR A
THUNDERSTORM. SOME SUB-VFR CONDITIONS MAY LINGER EARLY SATURDAY
MORNING. THERE COULD BE SOME POCKETS OF LOWER CLOUDS LATER SATURDAY
FOR A TIME, BUT CONFIDENCE IS LOW.
SUNDAY THROUGH TUESDAY...OVERALL VFR WITH A SOUTHERLY WIND. THERE
COULD BE SOME AFTERNOON AND EVENING SEA/BAY BREEZES DEVELOPING. ANY
SHOWERS OR THUNDERSTORMS SHOULD BE CONFINED TO OUR WEST AND MOSTLY
TERRAIN INDUCED, BUT THESE SHOULD BE TIED TO WEAK ENERGY MOVING
AROUND THE WEST SIDE OF HIGH PRESSURE. THERE IS LOW CONFIDENCE
REGARDING ANY SUB-VFR CONDITIONS IN THE EVENT THE MOISTURE INCREASES
ENOUGH TO RESULT IN POCKETS OF LOW CLOUDS/FOG THROUGH TIME.
&&
.MARINE...
IT LOOKS AS THOUGH WE HAVE WEATHERED THE THREAT FOR SMALL CRAFT
ADVISORY CONDITIONS FOR SEAS AND WINDS WITH THE ONSHORE FLOW TODAY.
THIS FLOW IS FORECAST TO WEAKEN AS WE GO THROUGH THE NIGHT. WINDS
SHOULD BECOME LIGHTER AND MORE VARIABLE ON FRIDAY PRECEDING THE
APPROACHING FRONT AND SEAS ARE NOT EXPECTED TO STAY BELOW SMALL
CRAFT ADVISORY CRITERIA ALSO.
OUTLOOK...
A WEAKENING SYSTEM WILL MOVE THROUGH FRIDAY NIGHT WITH ANY SHOWERS
ENDING. HIGH PRESSURE BUILDS DOWN FROM NEW ENGLAND SATURDAY WITH
PERHAPS A LITTLE SURGE IN ONSHORE WINDS, BUT THE GRADIENT LOOKS WEAK
ENOUGH TO KEEP WINDS BELOW 25 KNOTS. THIS SURFACE HIGH THEN
ESTABLISHES ITSELF ALONG AND JUST EAST OF THE MID ATLANTIC COAST
SUNDAY THROUGH TUESDAY WITH A SOUTHERLY WIND DEVELOPING. OVERALL,
THE WIND FIELD IS FORECAST TO BE ON THE LIGHTER SIDE WITH
SUB-ADVISORY CONDITIONS OCCURRING. THE LOCAL NEARSHORE WINDS MAY
BECOME ENHANCED SOME AT TIMES DUE TO ANY SEA/BAY BREEZE CIRCULATIONS
THAT DEVELOP.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...GIGI
SHORT TERM...GIGI
LONG TERM...GORSE
AVIATION...GIGI/GORSE
MARINE...GIGI/GORSE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
520 PM CDT THU MAR 15 2012
.DISCUSSION...UPDATE FOR LATE AFTERNOON INTO MID EVENING...
519 PM CDT
THUNDERSTORMS CONTINUE TO DEVELOP IN THE AXIS OF MAX SB CAPE...MU
CAPE AND LOWERS SHOWALTER INDEX VALUES FROM E CENTRAL IL ENE TO
NW IN. STRONGEST CORES HAVE THE POTENTIAL FOR PRODUCING SUB-SEVERE
HAIL INTO EARLY THIS EVE TIL HEATING FALLS OF AS SUN CONTINUES TO
LOWER TOWARD THE HORIZON.
TRS
&&
.PREV DISCUSSION...
301 PM CDT
MAIN CONCERNS FOR THE REMAINDER OF THE AFTERNOON WILL FOCUS ON THE
BACK DOOR COLD FRONT PUSHING DOWN TO THE SRN TIP OF LAKE MICHIGAN
AND INLAND NERN/NCNTRL IL...AS WELL AS PCPN AND TS CHANCES IN THE
WARM...MOIST AIR OVER THE REMAINDER OF THE AREA. THE FRONT HAS
ALREADY PUSHED INTO ERN LAKE COUNTY...IL AND CONTINUES TO PUSH
SOUTH. THE FOG/ST BEHIND THE FRONT HAS THINNED PER LATEST VIS
IMAGERY...BUT EXPECT THAT THERE SHOULD BE AT LEAST PATCHY FOG INLAND
AND THERE IS STILL THE POTENTIAL FOR AREAS OF DENSE FOG ALONG THE
LAKE FRONT AS THE LAKE COOLED AIR PUSHES INLAND THIS EVENING.
HOWEVER...GIVEN THE LACK OF DEVELOPMENT AT THE CURRENT TIME...WILL
DEFER ANY DENSE FOG HEADLINES TO THE EVENING OR MID SHIFTS. AS FOR
TS POTENTIAL...THE LATEST VIS IMAGERY SHOWS WIDESPREAD CU
DEVELOPMENT WITH DECENT VERTICAL GROWTH OVER PORTIONS OF THE AREA
SOUTH OF I-80...WITH LESSER DEVELOPED STRATOCU TO THE NORTH. FEEL
THAT THERE IS STILL A CHANCE FOR SOME ISOLD TS DEVELOPMENT AS FAR
NORTH AS THE I-80 OR I-88 CORRIDOR AS THE BETTER INSTABILITY SPREADS
NORTHWARD TO THE COLD FRONT. THE TS CHANCES WILL CONTINUE THROUGH
THE NIGHT OVER ALL BUT THE FAR NRN AND NERN PORTIONS OF THE CWA
GIVEN THE WARM...MOIST AIRMASS...BUT GIVEN THE LACK OF A FOCUSING
ELEMENT...ANY ACTIVITY SHOULD BE ISOLD. TEMPERATURES HAVE ALSO BEEN
AN ISSUE TODAY AS WITH TEMPS RISING INTO THE UPPER 70S TO LOWER
80S. LOCATIONS SOUTH OF THE FRONT STILL HAVE THE POTENTIAL TO WARM
A BIT MORE BEFORE SUNSET AND ROCKFORD AND OHARE HAVE ALREADY BROKEN
RECORDS FOR TODAY.
TEMPERATURES WILL REMAIN THE BIG NEWS FOR THE NEXT SEVERAL DAYS.
HAVE ACTUALLY MADE LITTLE CHANGE TO THE GOING FORECAST AS FAR AS
MAXT AND MINT ARE CONCERNED. WITH THE UPPER RIDGE REMAINING PARKED
OVER THE REGION AND PERSISTENT SLY-SWLY FLOW DRAWING WARM...MOIST
AIR NWD...RECORD OR NEAR RECORD HIGH TEMPS ARE LIKELY THROUGH EARLY
NEXT WEEK. ALSO...GIVEN LITTLE CHANGE IN THE LARGE SCALE
AIRMASS...THERE WILL ALSO BE PERIODIC CHANCES FOR SHRA/TSRA THROUGH
THE ENTIRE FORECAST PERIOD. HOWEVER...THERE WILL NO SIGNIFICANT
FOCUSING MECHANISM THROUGH THE PERIOD...SO HAVE CONTAINED POPS TO
CHANCE/SLIGHT CHANCE LEVELS.
THERE ARE SOME INDICATIONS THAT THE RECORD WARMTH MAY MODERATE BY
THE END OF THE PERIOD AS THE MEDIUM RANGE FORECAST GUIDANCE SHOWS A
CUT-OFF LOW KICKING OUT OF THE SRN ROCKIES AND MOVING OUT OVER THE
SOUTH HIGH PLAINS...THOUGH THERE SHOULD STILL BE UPPER RIDGING
POKING BACK FROM THE SERN CONUS TO THE UPPER MISSISSIPPI VALLEY.
EVEN THOUGH THE GFS AND ECMWF ARE IN UNUSUALLY GOOD AGREEMENT FOR
SUCH A FEATURE AT THAT TIME RANGE...HAVE LOW CONFIDENCE IN THE
TIMING OF THIS SCENARIO AS CUT OFF LOWS ARE NOTORIOUSLY SLOWER IN
LIFTING OUT THAN THE GUIDANCE WOULD SUGGEST.
KREIN
&&
.CLIMATE...
540 AM CDT
RECORD MAXIMUM TEMPERATURES FOR CHICAGO
MAR 15 74 1995
MAR 16 78 1945
MAR 17 74 2009
RECORD MAXIMUM TEMPERATURES FOR ROCKFORD
MAR 15 73 1995
MAR 16 75 1945
MAR 17 74 2003
NORMAL NUMBER OF 70 DEGREE DAYS IN MARCH FOR BOTH CHICAGO AND
ROCKFORD IS 1.2.
RECORD NUMBER OF DAYS WITH MAX TEMP 70 OR ABOVE IN MARCH
CHICAGO 9 IN 1945...6 IN 1910 AND 1907.
ROCKFORD 11 IN 1910...7 IN 1945.
RECORD FOR CONSECUTIVE 70 DEGREE DAYS IN MARCH
CHICAGO...5 FROM MARCH 12-16 1995.
ROCKFORD...9 MARCH 23-31 1910.
TEMPERATURES IN THE 80S ARE EXTREMELY RARE IN MARCH. FOR
CHICAGO...DATA GOES BACK TO 1872. THERE HAVE ONLY BEEN A TOTAL OF
10 DAYS IN MARCH WITH A HIGH TEMPERATURE OF 80 DEGREES. THE MOST
IN ONE YEAR WAS 2 IN 1986. FOR ROCKFORD RECORDS GO BACK TO 1906.
THERE HAVE ONLY BEEN 12 80 DEGREE DAYS IN MARCH. THE MOST IN ONE
YEAR WAS 2 IN 1907...1939...AND 1986.
ALLSOPP
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WINDS SHIFTING TO NORTHEAST LAST THIS AFTERNOON WITH A
COLD FRONT.
* POTENTIAL FOR IFR CIGS/VIS BEHIND THE FRONT OVERNIGHT.
* POTENTIAL FOR SHOWERS/TS THIS AFTERNOON INTO THE EVENING.
PAW
//DISCUSSION...UPDATED 21Z...
COLD FRONT COMING DOWN THE LAKE HAS SLOWED CONSIDERABLY AND HAVE
MADE SIGNIFICANT CHANGES TO THE GOING TIMING OF THE FORECAST.
INHERITED TAFOR HAVE WINDS FLIPPING TO NORTHEAST AT 21Z...BUT WITH
THE FRONT STALLING OUT...HAVE TRENDED BACK BY 3-4 HOURS...AND MAY
NEED TO TWEAK CLOSER WITH THE COMING AMD. RUC AND HRRR ANALYSIS
INDICATED A FLIP TO NORTHEAST...WITH THE FRONT BEGINNING TO MAKE
SOME MOVEMENT AS THE SUN GOES DOWN...PUSHING THROUGH THE EASTERN
TERMINALS BEYOND 00Z. OVERNIGHT CIG/FOG FORECAST REMAINS UNCHANGED.
SHEA
//DISCUSSION...UPDATED 18Z...
COLD FRONT MOVING INTO NORTHERN ILLINOIS AND NORTHWEST INDIANA
FROM THE NORTH THIS AFTERNOON BEFORE STALLING OUT. WINDS WILL
SHIFT TO THE NORTHEAST WITH THE FRONT. AN AREA OF LOWER CEILING
AND VISIBILITIES BEHIND THE FRONT WILL MOVE INTO THE TERMINALS
WITHIN AN HOUR OR TWO OF FRONTAL PASSAGE AND PERSIST THROUGH THE
EVENING. LOWEST CONDITIONS SHOULD BE NEAR LAKE MICHIGAN...AND A
LITTLE BETTER FURTHER AWAY FROM THE LAKE. FRONT IN THE AREA COULD
BE A FOCUS FOR SOME ISOLATED SHOWERS/TS LATE THIS AFTERNOON AND
THIS EVENING...THOUGH THE BETTER CHANCE IS SOUTH OF THE TERMINALS.
BY FRIDAY MORNING WINDS WILL SHIFT TO THE SOUTHEAST ALLOWING
WHATEVER REMAINS OF LOWER CEILINGS AND VISIBILITIES TO IMPROVE TO
VFR.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN TIMING OF WINDSHIFT.
* LOW CONFIDENCE IN IFR OCCURRING AND TIMING.
* LOW CONFIDENCE IN SHOWERS/TS.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT THROUGH SUNDAY...PREVAILING VFR...CHANCE TSRA
PRODUCING LOCAL MVFR TO IFR.
* SUNDAY NIGHT THROUGH TUESDAY NIGHT...VFR.
* WEDNESDAY...PREVAILING VFR...CHANCE TSRA PRODUCING LOCAL MVFR
TO IFR. CMS
&&
.MARINE...
321 PM CDT
THE COLD FRONT CONTINUES TO SINK SOUTH ACROSS THE SOUTHERN THIRD OF
LAKE MICHIGAN THIS AFTERNOON...AND SHOULD BE SOUTH OF LAKE MICHIGAN
BY THIS EVENING. HOWEVER...THE FRONT HAS SLOWED OVER THE PAST FEW
HOURS...SO IT MAY NOT PASS THROUGH THE SOUTHERN PORTIONS OF LAKE
MICHIGAN UNTIL LATE TONIGHT IF AT ALL. WINDS WILL ABRUPTLY CHANGE
FROM SOUTHWEST TO NORTHEAST BEHIND THE FRONT. EARLIER TODAY AREAS
IN SOUTHEAST WISCONSIN EXPERIENCED BRIEF PERIODS OF VISIBILITY
BELOW 1 MILE IMMEDIATELY BEHIND THE FRONT...BUT CURRENT
SATELLITE IMAGERY INDICATES THE FOG IS ERODING.
THEREFORE...REDUCED VISIBILITIES ARE POSSIBLE IMMEDIATELY BEHIND
THE FRONT...BUT WILL NOT PERSIST AND THE FOG MAY NOT REDUCE
VISIBILITY TO BELOW 1 MILE. THE FRONT IS EXPECTED TO STALL JUST
SOUTH OF THE LAKE AND THEN MOVE NORTHEASTWARD TOMORROW AS A WARM
FRONT.
WINDS BECOME EAST OVER THE OPEN WATER TONIGHT AS HIGH PRESSURE
PASSES OVER LAKE SUPERIOR LATE TONIGHT. WINDS CONTINUE TO VEER TO
SOUTHERLY BY FRIDAY AFTERNOON. A PROLONGED PERIOD OF LIGHT
SOUTHERLY WINDS WILL PERSIST THROUGH TUESDAY AS WE REMAIN BETWEEN
SYSTEMS.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
519 PM CDT THU MAR 15 2012
.DISCUSSION...
301 PM CDT
MAIN CONCERNS FOR THE REMAINDER OF THE AFTERNOON WILL FOCUS ON THE
BACK DOOR COLD FRONT PUSHING DOWN TO THE SRN TIP OF LAKE MICHIGAN
AND INLAND NERN/NCNTRL IL...AS WELL AS PCPN AND TS CHANCES IN THE
WARM...MOIST AIR OVER THE REMAINDER OF THE AREA. THE FRONT HAS
ALREADY PUSHED INTO ERN LAKE COUNTY...IL AND CONTINUES TO PUSH
SOUTH. THE FOG/ST BEHIND THE FRONT HAS THINNED PER LATEST VIS
IMAGERY...BUT EXPECT THAT THERE SHOULD BE AT LEAST PATCHY FOG INLAND
AND THERE IS STILL THE POTENTIAL FOR AREAS OF DENSE FOG ALONG THE
LAKE FRONT AS THE LAKE COOLED AIR PUSHES INLAND THIS EVENING.
HOWEVER...GIVEN THE LACK OF DEVELOPMENT AT THE CURRENT TIME...WILL
DEFER ANY DENSE FOG HEADLINES TO THE EVENING OR MID SHIFTS. AS FOR
TS POTENTIAL...THE LATEST VIS IMAGERY SHOWS WIDESPREAD CU
DEVELOPMENT WITH DECENT VERTICAL GROWTH OVER PORTIONS OF THE AREA
SOUTH OF I-80...WITH LESSER DEVELOPED STRATOCU TO THE NORTH. FEEL
THAT THERE IS STILL A CHANCE FOR SOME ISOLD TS DEVELOPMENT AS FAR
NORTH AS THE I-80 OR I-88 CORRIDOR AS THE BETTER INSTABILITY SPREADS
NORTHWARD TO THE COLD FRONT. THE TS CHANCES WILL CONTINUE THROUGH
THE NIGHT OVER ALL BUT THE FAR NRN AND NERN PORTIONS OF THE CWA
GIVEN THE WARM...MOIST AIRMASS...BUT GIVEN THE LACK OF A FOCUSING
ELEMENT...ANY ACTIVITY SHOULD BE ISOLD. TEMPERATURES HAVE ALSO BEEN
AN ISSUE TODAY AS WITH TEMPS RISING INTO THE UPPER 70S TO LOWER
80S. LOCATIONS SOUTH OF THE FRONT STILL HAVE THE POTENTIAL TO WARM
A BIT MORE BEFORE SUNSET AND ROCKFORD AND OHARE HAVE ALREADY BROKEN
RECORDS FOR TODAY.
TEMPERATURES WILL REMAIN THE BIG NEWS FOR THE NEXT SEVERAL DAYS.
HAVE ACTUALLY MADE LITTLE CHANGE TO THE GOING FORECAST AS FAR AS
MAXT AND MINT ARE CONCERNED. WITH THE UPPER RIDGE REMAINING PARKED
OVER THE REGION AND PERSISTENT SLY-SWLY FLOW DRAWING WARM...MOIST
AIR NWD...RECORD OR NEAR RECORD HIGH TEMPS ARE LIKELY THROUGH EARLY
NEXT WEEK. ALSO...GIVEN LITTLE CHANGE IN THE LARGE SCALE
AIRMASS...THERE WILL ALSO BE PERIODIC CHANCES FOR SHRA/TSRA THROUGH
THE ENTIRE FORECAST PERIOD. HOWEVER...THERE WILL NO SIGNIFICANT
FOCUSING MECHANISM THROUGH THE PERIOD...SO HAVE CONTAINED POPS TO
CHANCE/SLIGHT CHANCE LEVELS.
THERE ARE SOME INDICATIONS THAT THE RECORD WARMTH MAY MODERATE BY
THE END OF THE PERIOD AS THE MEDIUM RANGE FORECAST GUIDANCE SHOWS A
CUT-OFF LOW KICKING OUT OF THE SRN ROCKIES AND MOVING OUT OVER THE
SOUTH HIGH PLAINS...THOUGH THERE SHOULD STILL BE UPPER RIDGING
POKING BACK FROM THE SERN CONUS TO THE UPPER MISSISSIPPI VALLEY.
EVEN THOUGH THE GFS AND ECMWF ARE IN UNUSUALLY GOOD AGREEMENT FOR
SUCH A FEATURE AT THAT TIME RANGE...HAVE LOW CONFIDENCE IN THE
TIMING OF THIS SCENARIO AS CUT OFF LOWS ARE NOTORIOUSLY SLOWER IN
LIFTING OUT THAN THE GUIDANCE WOULD SUGGEST.
KREIN
&&
.CLIMATE...
540 AM CDT
RECORD MAXIMUM TEMPERATURES FOR CHICAGO
MAR 15 74 1995
MAR 16 78 1945
MAR 17 74 2009
RECORD MAXIMUM TEMPERATURES FOR ROCKFORD
MAR 15 73 1995
MAR 16 75 1945
MAR 17 74 2003
NORMAL NUMBER OF 70 DEGREE DAYS IN MARCH FOR BOTH CHICAGO AND
ROCKFORD IS 1.2.
RECORD NUMBER OF DAYS WITH MAX TEMP 70 OR ABOVE IN MARCH
CHICAGO 9 IN 1945...6 IN 1910 AND 1907.
ROCKFORD 11 IN 1910...7 IN 1945.
RECORD FOR CONSECUTIVE 70 DEGREE DAYS IN MARCH
CHICAGO...5 FROM MARCH 12-16 1995.
ROCKFORD...9 MARCH 23-31 1910.
TEMPERATURES IN THE 80S ARE EXTREMELY RARE IN MARCH. FOR
CHICAGO...DATA GOES BACK TO 1872. THERE HAVE ONLY BEEN A TOTAL OF
10 DAYS IN MARCH WITH A HIGH TEMPERATURE OF 80 DEGREES. THE MOST
IN ONE YEAR WAS 2 IN 1986. FOR ROCKFORD RECORDS GO BACK TO 1906.
THERE HAVE ONLY BEEN 12 80 DEGREE DAYS IN MARCH. THE MOST IN ONE
YEAR WAS 2 IN 1907...1939...AND 1986.
ALLSOPP
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* WINDS SHIFTING TO NORTHEAST THIS EVENING WITH A
COLD FRONT.
* POTENTIAL FOR IFR CIGS/VIS BEHIND THE FRONT OVERNIGHT.
SHEA
//DISCUSSION...UPDATED 21Z...
COLD FRONT COMING DOWN THE LAKE HAS SLOWED CONSIDERABLY AND HAVE
MADE SIGNIFICANT CHANGES TO THE GOING TIMING OF THE FORECAST.
INHERITED TAFOR HAVE WINDS FLIPPING TO NORTHEAST AT 21Z...BUT WITH
THE FRONT STALLING OUT...HAVE TRENDED BACK BY 3-4 HOURS...AND MAY
NEED TO TWEAK CLOSER WITH THE COMING AMD. RUC AND HRRR ANALYSIS
INDICATED A FLIP TO NORTHEAST...WITH THE FRONT BEGINNING TO MAKE
SOME MOVEMENT AS THE SUN GOES DOWN...PUSHING THROUGH THE EASTERN
TERMINALS BEYOND 00Z. OVERNIGHT CIG/FOG FORECAST REMAINS UNCHANGED.
SHEA
//DISCUSSION...UPDATED 18Z...
COLD FRONT MOVING INTO NORTHERN ILLINOIS AND NORTHWEST INDIANA
FROM THE NORTH THIS AFTERNOON BEFORE STALLING OUT. WINDS WILL
SHIFT TO THE NORTHEAST WITH THE FRONT. AN AREA OF LOWER CEILING
AND VISIBILITIES BEHIND THE FRONT WILL MOVE INTO THE TERMINALS
WITHIN AN HOUR OR TWO OF FRONTAL PASSAGE AND PERSIST THROUGH THE
EVENING. LOWEST CONDITIONS SHOULD BE NEAR LAKE MICHIGAN...AND A
LITTLE BETTER FURTHER AWAY FROM THE LAKE. FRONT IN THE AREA COULD
BE A FOCUS FOR SOME ISOLATED SHOWERS/TS LATE THIS AFTERNOON AND
THIS EVENING...THOUGH THE BETTER CHANCE IS SOUTH OF THE TERMINALS.
BY FRIDAY MORNING WINDS WILL SHIFT TO THE SOUTHEAST ALLOWING
WHATEVER REMAINS OF LOWER CEILINGS AND VISIBILITIES TO IMPROVE TO
VFR.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM CONFIDENCE IN TIMING OF WINDSHIFT.
* LOW CONFIDENCE IN IFR OCCURRING AND TIMING.
SHEA
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT THROUGH SUNDAY...PREVAILING VFR...CHANCE TSRA
PRODUCING LOCAL MVFR TO IFR.
* SUNDAY NIGHT THROUGH TUESDAY NIGHT...VFR.
* WEDNESDAY...PREVAILING VFR...CHANCE TSRA PRODUCING LOCAL MVFR
TO IFR. CMS
&&
.MARINE...
321 PM CDT
THE COLD FRONT CONTINUES TO SINK SOUTH ACROSS THE SOUTHERN THIRD OF
LAKE MICHIGAN THIS AFTERNOON...AND SHOULD BE SOUTH OF LAKE MICHIGAN
BY THIS EVENING. HOWEVER...THE FRONT HAS SLOWED OVER THE PAST FEW
HOURS...SO IT MAY NOT PASS THROUGH THE SOUTHERN PORTIONS OF LAKE
MICHIGAN UNTIL LATE TONIGHT IF AT ALL. WINDS WILL ABRUPTLY CHANGE
FROM SOUTHWEST TO NORTHEAST BEHIND THE FRONT. EARLIER TODAY AREAS
IN SOUTHEAST WISCONSIN EXPERIENCED BRIEF PERIODS OF VISIBILITY
BELOW 1 MILE IMMEDIATELY BEHIND THE FRONT...BUT CURRENT
SATELLITE IMAGERY INDICATES THE FOG IS ERODING.
THEREFORE...REDUCED VISIBILITIES ARE POSSIBLE IMMEDIATELY BEHIND
THE FRONT...BUT WILL NOT PERSIST AND THE FOG MAY NOT REDUCE
VISIBILITY TO BELOW 1 MILE. THE FRONT IS EXPECTED TO STALL JUST
SOUTH OF THE LAKE AND THEN MOVE NORTHEASTWARD TOMORROW AS A WARM
FRONT.
WINDS BECOME EAST OVER THE OPEN WATER TONIGHT AS HIGH PRESSURE
PASSES OVER LAKE SUPERIOR LATE TONIGHT. WINDS CONTINUE TO VEER TO
SOUTHERLY BY FRIDAY AFTERNOON. A PROLONGED PERIOD OF LIGHT
SOUTHERLY WINDS WILL PERSIST THROUGH TUESDAY AS WE REMAIN BETWEEN
SYSTEMS.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
337 PM CDT THU MAR 15 2012
.DISCUSSION...
301 PM CDT
MAIN CONCERNS FOR THE REMAINDER OF THE AFTERNOON WILL FOCUS ON THE
BACK DOOR COLD FRONT PUSHING DOWN TO THE SRN TIP OF LAKE MICHIGAN
AND INLAND NERN/NCNTRL IL...AS WELL AS PCPN AND TS CHANCES IN THE
WARM...MOIST AIR OVER THE REMAINDER OF THE AREA. THE FRONT HAS
ALREADY PUSHED INTO ERN LAKE COUNTY...IL AND CONTINUES TO PUSH
SOUTH. THE FOG/ST BEHIND THE FRONT HAS THINNED PER LATEST VIS
IMAGERY...BUT EXPECT THAT THERE SHOULD BE AT LEAST PATCHY FOG INLAND
AND THERE IS STILL THE POTENTIAL FOR AREAS OF DENSE FOG ALONG THE
LAKE FRONT AS THE LAKE COOLED AIR PUSHES INLAND THIS EVENING.
HOWEVER...GIVEN THE LACK OF DEVELOPMENT AT THE CURRENT TIME...WILL
DEFER ANY DENSE FOG HEADLINES TO THE EVENING OR MID SHIFTS. AS FOR
TS POTENTIAL...THE LATEST VIS IMAGERY SHOWS WIDESPREAD CU
DEVELOPMENT WITH DECENT VERTICAL GROWTH OVER PORTIONS OF THE AREA
SOUTH OF I-80...WITH LESSER DEVELOPED STRATOCU TO THE NORTH. FEEL
THAT THERE IS STILL A CHANCE FOR SOME ISOLD TS DEVELOPMENT AS FAR
NORTH AS THE I-80 OR I-88 CORRIDOR AS THE BETTER INSTABILITY SPREADS
NORTHWARD TO THE COLD FRONT. THE TS CHANCES WILL CONTINUE THROUGH
THE NIGHT OVER ALL BUT THE FAR NRN AND NERN PORTIONS OF THE CWA
GIVEN THE WARM...MOIST AIRMASS...BUT GIVEN THE LACK OF A FOCUSING
ELEMENT...ANY ACTIVITY SHOULD BE ISOLD. TEMPERATURES HAVE ALSO BEEN
AN ISSUE TODAY AS WITH TEMPS RISING INTO THE UPPER 70S TO LOWER
80S. LOCATIONS SOUTH OF THE FRONT STILL HAVE THE POTENTIAL TO WARM
A BIT MORE BEFORE SUNSET AND ROCKFORD AND OHARE HAVE ALREADY BROKEN
RECORDS FOR TODAY.
TEMPERATURES WILL REMAIN THE BIG NEWS FOR THE NEXT SEVERAL DAYS.
HAVE ACTUALLY MADE LITTLE CHANGE TO THE GOING FORECAST AS FAR AS
MAXT AND MINT ARE CONCERNED. WITH THE UPPER RIDGE REMAINING PARKED
OVER THE REGION AND PERSISTENT SLY-SWLY FLOW DRAWING WARM...MOIST
AIR NWD...RECORD OR NEAR RECORD HIGH TEMPS ARE LIKELY THROUGH EARLY
NEXT WEEK. ALSO...GIVEN LITTLE CHANGE IN THE LARGE SCALE
AIRMASS...THERE WILL ALSO BE PERIODIC CHANCES FOR SHRA/TSRA THROUGH
THE ENTIRE FORECAST PERIOD. HOWEVER...THERE WILL NO SIGNIFICANT
FOCUSING MECHANISM THROUGH THE PERIOD...SO HAVE CONTAINED POPS TO
CHANCE/SLIGHT CHANCE LEVELS.
THERE ARE SOME INDICATIONS THAT THE RECORD WARMTH MAY MODERATE BY
THE END OF THE PERIOD AS THE MEDIUM RANGE FORECAST GUIDANCE SHOWS A
CUT-OFF LOW KICKING OUT OF THE SRN ROCKIES AND MOVING OUT OVER THE
SOUTH HIGH PLAINS...THOUGH THERE SHOULD STILL BE UPPER RIDGING
POKING BACK FROM THE SERN CONUS TO THE UPPER MISSISSIPPI VALLEY.
EVEN THOUGH THE GFS AND ECMWF ARE IN UNUSUALLY GOOD AGREEMENT FOR
SUCH A FEATURE AT THAT TIME RANGE...HAVE LOW CONFIDENCE IN THE
TIMING OF THIS SCENARIO AS CUT OFF LOWS ARE NOTORIOUSLY SLOWER IN
LIFTING OUT THAN THE GUIDANCE WOULD SUGGEST.
KREIN
&&
.CLIMATE...
540 AM CDT
RECORD MAXIMUM TEMPERATURES FOR CHICAGO
MAR 15 74 1995
MAR 16 78 1945
MAR 17 74 2009
RECORD MAXIMUM TEMPERATURES FOR ROCKFORD
MAR 15 73 1995
MAR 16 75 1945
MAR 17 74 2003
NORMAL NUMBER OF 70 DEGREE DAYS IN MARCH FOR BOTH CHICAGO AND
ROCKFORD IS 1.2.
RECORD NUMBER OF DAYS WITH MAX TEMP 70 OR ABOVE IN MARCH
CHICAGO 9 IN 1945...6 IN 1910 AND 1907.
ROCKFORD 11 IN 1910...7 IN 1945.
RECORD FOR CONSECUTIVE 70 DEGREE DAYS IN MARCH
CHICAGO...5 FROM MARCH 12-16 1995.
ROCKFORD...9 MARCH 23-31 1910.
TEMPERATURES IN THE 80S ARE EXTREMELY RARE IN MARCH. FOR
CHICAGO...DATA GOES BACK TO 1872. THERE HAVE ONLY BEEN A TOTAL OF
10 DAYS IN MARCH WITH A HIGH TEMPERATURE OF 80 DEGREES. THE MOST
IN ONE YEAR WAS 2 IN 1986. FOR ROCKFORD RECORDS GO BACK TO 1906.
THERE HAVE ONLY BEEN 12 80 DEGREE DAYS IN MARCH. THE MOST IN ONE
YEAR WAS 2 IN 1907...1939...AND 1986.
ALLSOPP
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WINDS SHIFTING TO NORTHEAST LAST THIS AFTERNOON WITH A
COLD FRONT.
* POTENTIAL FOR IFR CIGS/VIS BEHIND THE FRONT OVERNIGHT.
* POTENTIAL FOR SHOWERS/TS THIS AFTERNOON INTO THE EVENING.
PAW
//DISCUSSION...UPDATED 21Z...
COLD FRONT COMING DOWN THE LAKE HAS SLOWED CONSIDERABLY AND HAVE
MADE SIGNIFICANT CHANGES TO THE GOING TIMING OF THE FORECAST.
INHERITED TAFOR HAVE WINDS FLIPPING TO NORTHEAST AT 21Z...BUT WITH
THE FRONT STALLING OUT...HAVE TRENDED BACK BY 3-4 HOURS...AND MAY
NEED TO TWEAK CLOSER WITH THE COMING AMD. RUC AND HRRR ANALYSIS
INDICATED A FLIP TO NORTHEAST...WITH THE FRONT BEGINNING TO MAKE
SOME MOVEMENT AS THE SUN GOES DOWN...PUSHING THROUGH THE EASTERN
TERMINALS BEYOND 00Z. OVERNIGHT CIG/FOG FORECAST REMAINS UNCHANGED.
SHEA
//DISCUSSION...UPDATED 18Z...
COLD FRONT MOVING INTO NORTHERN ILLINOIS AND NORTHWEST INDIANA
FROM THE NORTH THIS AFTERNOON BEFORE STALLING OUT. WINDS WILL
SHIFT TO THE NORTHEAST WITH THE FRONT. AN AREA OF LOWER CEILING
AND VISIBILITIES BEHIND THE FRONT WILL MOVE INTO THE TERMINALS
WITHIN AN HOUR OR TWO OF FRONTAL PASSAGE AND PERSIST THROUGH THE
EVENING. LOWEST CONDITIONS SHOULD BE NEAR LAKE MICHIGAN...AND A
LITTLE BETTER FURTHER AWAY FROM THE LAKE. FRONT IN THE AREA COULD
BE A FOCUS FOR SOME ISOLATED SHOWERS/TS LATE THIS AFTERNOON AND
THIS EVENING...THOUGH THE BETTER CHANCE IS SOUTH OF THE TERMINALS.
BY FRIDAY MORNING WINDS WILL SHIFT TO THE SOUTHEAST ALLOWING
WHATEVER REMAINS OF LOWER CEILINGS AND VISIBILITIES TO IMPROVE TO
VFR.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN TIMING OF WINDSHIFT.
* LOW CONFIDENCE IN IFR OCCURRING AND TIMING.
* LOW CONFIDENCE IN SHOWERS/TS.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT THROUGH SUNDAY...PREVAILING VFR...CHANCE TSRA
PRODUCING LOCAL MVFR TO IFR.
* SUNDAY NIGHT THROUGH TUESDAY NIGHT...VFR.
* WEDNESDAY...PREVAILING VFR...CHANCE TSRA PRODUCING LOCAL MVFR
TO IFR. CMS
&&
.MARINE...
321 PM CDT
THE COLD FRONT CONTINUES TO SINK SOUTH ACROSS THE SOUTHERN THIRD OF
LAKE MICHIGAN THIS AFTERNOON...AND SHOULD BE SOUTH OF LAKE MICHIGAN
BY THIS EVENING. HOWEVER...THE FRONT HAS SLOWED OVER THE PAST FEW
HOURS...SO IT MAY NOT PASS THROUGH THE SOUTHERN PORTIONS OF LAKE
MICHIGAN UNTIL LATE TONIGHT IF AT ALL. WINDS WILL ABRUPTLY CHANGE
FROM SOUTHWEST TO NORTHEAST BEHIND THE FRONT. EARLIER TODAY AREAS
IN SOUTHEAST WISCONSIN EXPERIENCED BRIEF PERIODS OF VISIBILITY
BELOW 1 MILE IMMEDIATELY BEHIND THE FRONT...BUT CURRENT
SATELLITE IMAGERY INDICATES THE FOG IS ERODING.
THEREFORE...REDUCED VISIBILITIES ARE POSSIBLE IMMEDIATELY BEHIND
THE FRONT...BUT WILL NOT PERSIST AND THE FOG MAY NOT REDUCE
VISIBILITY TO BELOW 1 MILE. THE FRONT IS EXPECTED TO STALL JUST
SOUTH OF THE LAKE AND THEN MOVE NORTHEASTWARD TOMORROW AS A WARM
FRONT.
WINDS BECOME EAST OVER THE OPEN WATER TONIGHT AS HIGH PRESSURE
PASSES OVER LAKE SUPERIOR LATE TONIGHT. WINDS CONTINUE TO VEER TO
SOUTHERLY BY FRIDAY AFTERNOON. A PROLONGED PERIOD OF LIGHT
SOUTHERLY WINDS WILL PERSIST THROUGH TUESDAY AS WE REMAIN BETWEEN
SYSTEMS.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1153 PM CDT WED MAR 14 2012
.DISCUSSION...
ISSUED 904 PM CDT WED MAR 14 2012
MADE A FEW MINOR ADJUSTMENTS TO THE FORECAST FOR SKY COVER AND
PRECIPITATION CHANCES OVERNIGHT. THE LATEST SATELLITE LOOP SHOWS A
FEW LOW CLOUDS IN CENTRAL IL...WITH CONVECTIVE DEBRIS CLOUDS IN
SOUTHEAST IL. MAINLY CLEAR SKIES WILL BE THE RULE EARLY TONIGHT AS
THE CONVECTIVE DEBRIS MOVES OUT OF THE AREA. SCATTERED MID AND
THEN LOW CLOUDS WILL INCREASE IN AREAS NORTHWEST OF THE IL RIVER
OVERNIGHT AS A WEAK SURFACE BOUNDARY MOVES TOWARD NW IL. THE
LATEST WRF AND HRRR MODELS INDICATE SOME LIGHT SHOWERS MAY
ACCOMPANY THE CLOUDS IN NORTH CENTRAL IL...SO WILL KEEP AT LEAST A
20 POP IN THE OVERNIGHT FORECAST.
WILL KEEP THE CHANCE POPS IN SOUTHEAST IL SINCE HIGH INSTABILITY
AIR IS IN PLACE WITH CAPES OF 2000-2500 AND WEAK UPPER LEVEL
FORCING COULD PRODUCE SCATTERED T-STORMS TONIGHT.
WITH UNSEASONABLY MILD DEW POINTS IN THE UPPER 50S TO LOWER 60S...
OVERNIGHT LOWS WILL ONLY DIP INTO THE LOWER 60S...WHICH THE
PREVIOUS FORECAST HAS A GOOD HANDLE ON.
&&
.AVIATION...
ISSUED 1154 PM CDT WED MAR 14 2012
ALL OF CENTRAL ILLINOIS WILL REMAIN IN THE UNSEASONABLY WARM AND
HUMID AIRMASS THROUGH THE NEXT 24 HOURS...AND FOR SEVERAL DAYS
BEYOND. THIS WILL RESULT IN PERIODIC CHANCES FOR ISOLATED
THUNDERSTORMS EARLY THIS MORNING AND AGAIN DURING THE AFTERNOON
AND EARLY EVENING THURSDAY. THE MOST LIKELY AREA TO SEE A FEW
T-STORMS EARLY THIS MORNING WILL BE IN THE VICINITY OF KPIA
BECAUSE OF LOW LEVEL CONVERGENCE FOCUSING IN THIS REGION.
ALL OF CENTRAL ILLINOIS WILL SEE A BREAK IN THE CONVECTIVE CLOUD
DEBRIS AFTER 10Z...RESULTING IN THE DEVELOPMENT OF LIGHT FOG AND
MVFR VISIBILITY.
IT WILL BE DIFFICULT TO PINPOINT EXACTLY WHERE CONVECTION WILL
FIRE UP DURING THE AFTERNOON AND EARLY EVENING IN CENTRAL IL
THURSDAY BECAUSE OF THE LACK OF A GOOD FOCUSING BOUNDARY AND WEAK
UPPER SUPPORT...DESPITE ADEQUATE INSTABILITY. AS A RESULT...WILL
MENTION CB IN THE TAFS FOR MOST TAF SITES UP UNTIL 00Z.
MILLER
&&
.PREV DISCUSSION...
ISSUED 252 PM CDT WED MAR 14 2012
18Z SFC MAP SHOWED A LATE SPRING PATTERN IN PLACE AS SOUTHWEST WINDS
GUSTING UP TO 30 MPH AHEAD OF A COLD FRONT IN WESTERN
IOWA...HELPED BOOST TEMPERATURES TO RECORD LEVELS THE UPPER
70S AND LOWER 80S. SEVERAL DAYS OF SUSTAINED SOUTHERLY FLOW HAS
ALLOWED DEWPOINTS TO CLIMB TO UNSEASONABLY HIGH LEVELS IN THE
LOWER 60S. ALOFT...BROAD WEST-SOUTHWEST MID LEVEL FLOW FEATURED
SEVERAL WEAK EMBEDDED SHORTWAVES WHICH WILL BE THE FOCUS FOR
THUNDERSTORM CHANCES THE NEXT FEW DAYS.
SHORT TERM...TONIGHT THROUGH THURSDAY
POTENTIAL CONVECTION FOR THE SOUTHEAST HALF OF THE AREA LATE THIS
AFTERNOON AND EVENING IS FIRST FORECAST CONCERN. WARM AND HUMID
BOUNDARY LAYER COMBINED WITH STEEP MID LEVEL LAPSE RATES AND
INCREASING MOISTURE ADVECTION BELOW 800 MB HAVE LED TO AN UNCAPPED
ATMOSPHERE WITH SURFACE BASED CAPES OF 2500-3000 J/KG. INCREASING
DPVA AHEAD OF A WEAK SHORTWAVE LIFTING NE OUT OF OKLAHOMA SHOULD
LEAD TO AN INCREASE IN CONVECTION ACROSS SOUTHEAST MISSOURI AND
SOUTHERN ILLINOIS OVER THE NEXT COUPLE HOURS. WIND FIELDS ALOFT
ARE UNCHARACTERISTICALLY WEAK FOR EARLY SPRING...WITH 0-6 KM
EFFECTIVE SHEAR ONLY 25 KTS. THIS SHOULD LEAD TO A
DISORGANIZED/PULSE TYPE THUNDERSTORM MODE AND EVEN WITH HIGH
INSTABILITY WOULD ONLY EXPECT SOME NEAR SVR WIND GUSTS AND HAIL
PRIMARILY IN A 3PM-7PM WINDOW...AND BEST CHANCES SOUTH OF I-70. THIS
THINKING IS SUPPORTED BY LATEST RUN HIGH-RES HRRR AND WRF-NMM
MODEL RUNS...WITH ANY CONVECTION PUSHING INTO INDIANA AFTER 7 OR 8
PM.
THE NEXT FOCUS FOR THUNDERSTORM DEVELOPMENT LOOKS TO BE
AHEAD OF THE COLD FRONT TO OUR NORTHWEST. ISOLATED TO SCATTERED
ELEVATED STORMS SHOULD FORM LATER THIS EVENING NEAR OR EAST OF THE
MISSISSIPPI RIVER AS 30-35 KT WSW ORIENTED LOW LEVEL JET DEVELOPS.
DUE TO LIMITED INSTABILITY SEVERE STORMS ARE NOT EXPECTED WITH
THIS ACTIVITY AS IT DROPS SOUTHEAST OVERNIGHT.
THE COLD FRONT WILL BECOME ALIGNED WITH THE UPPER LEVEL FLOW ON
THURSDAY AND TEND TO PUSH MORE EAST THAN SOUTH. CURRENT GUIDANCE
SUGGESTS THE FRONT WILL NOT MAKE IT INTO OUR CWA SO ANOTHER DAY
WITH HIGHS NEAR 80. ASSUMING THE FRONT STAYS TO OUR NORTH AND
WASHES OUT...ANY CONVECTION WOULD BE DRIVEN BY SUBTLE SHORTWAVE
ENERGY. HAVE MAINTAINED LOW CHC POPS DUE TO UNCERTAINTY IN
TIMING OR LOCATION OF DEVELOPMENT...BUT WITH HIGH INSTABILITY HAIL
AND GUSTY WINDS WOULD BE POSSIBLE.
LONG TERM...FRIDAY THROUGH WEDNESDAY
THE EXTENDED PORTION OF THE FORECAST WILL FEATURE AN AMPLIFIED
UPPER AIR PATTERN WITH A WESTERN TROUGH DEEPENING AS IT APPROACHES
THE ROCKIES EARLY NEXT WEEK...WHILE A STRONG RIDGE BUILDS ACROSS
THE EASTERN THIRD OF THE COUNTRY. THIS WILL KEEP THE LOCAL AREA
BATHED IN SOUTHERLY FLOW AND TEMPERATURES MORE TYPICAL OF MID TO
LATE MAY WITH HIGHS IN THE 70S TO NEAR 80 AND LOWS IN THE UPPER 50S.
DEW POINTS WILL CONTINUE TO BE UNSEASONABLY HIGH IN THE UPPER 50S
TO LOWER 60S...GIVING A SOMEWHAT HUMID FEEL TO THE AIR. THE BEST
CHANCE OF THUNDERSTORMS DURING THE PERIOD WILL BE SATURDAY WHEN A
MORE ORGANIZED SHORTWAVE LIFTS FROM THE CENTRAL PLAINS INTO THE
LOWER GREAT LAKES. HAVE TRIED TO FOCUS ANOTHER PERIOD OF HIGHER
POPS LATE IN THE EXTENDED WHEN THE UPPER TROUGH TRACKS EAST INTO
THE PLAINS. LATEST 12Z RUN GFS AND ECMWF HAVE SLOWED THIS SYSTEM
WITH AN UPPER LOW CUTTING OFF IN THE SOUTHERN OR CENTRAL PLAINS.
THIS WOULD KEEP THE AREA IN SOUTHERLY FLOW THROUGH MID WEEK WITH
EASTERN FRINGES OF A MORE UNSETTLED PATTERN APPROACHING THE
MISSISSIPPI RIVER VALLEY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
431 PM EDT THU MAR 15 2012
.UPDATE...
AVIATION SECTIONS UPDATED
&&
.SYNOPSIS...
A BROAD UPPER LEVEL RIDGE WILL PERSIST ACROSS THE EASTERN PART OF
THE COUNTRY INTO THE MIDDLE OF NEXT WEEK...WITH TEMPERATURES
CONTINUING AT WELL ABOVE NORMAL AND NEAR RECORD LEVELS. SEVERAL
DISTURBANCES ALOFT WILL PROGRESS THROUGH THE UPPER RIDGE...PROVIDING
PERIODIC CHANCES FOR THUNDERSTORMS OVER CENTRAL INDIANA THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF THIS AFTERNOON INTO TONIGHT/...
AS OF 130 PM THIS AFTERNOON...ALL EYES TURN TO THE MCS MOVING TOWARD
THE SW FORECAST AREA FROM SE MO/SW IL. THIS FEATURE IS ASSOCIATED
WITH AN UPPER VORT MAX AND ALL SHORT TERM GUIDANCE AGREES ON
MOVING THIS FEATURE THROUGH THE OH VALLEY LATE THIS AFTERNOON AND
EVENING. SCATTERED CONVECTION WILL MOVE INTO CWA IN THE NEXT HOUR OR
SO AND THEN SPREAD QUICKLY AS DAYTIME HEATING WILL HAVE ALLOWED MANY
LOCATIONS TO REACH THEIR CONVECTIVE TEMPERATURES ACROSS THE REST OF
CENTRAL INDIANA AND THE ENTIRE OHIO VALLEY REMAINS UNDER A MOIST AND
UNSTABLE AIRMASS. THE PRESENCE OF A WEAK FRONTAL BOUNDARY TO THE
NORTH WILL LIKELY HAVE SOME INFLUENCE ON CONVECTION BUT STILL
APPEARS THE VORT MAX/MCS WILL BE THE MAIN DRIVING FEATURE
RESPONSIBLE FOR INDUCING CONVECTION OVER THE CWA AND THE OHIO VALLEY
BY LATE THIS AFTERNOON AND INTO THE EVENING.
EVEN THOUGH THE SLIGHT RISK HAS BEEN EXPANDED FARTHER NORTHWARD WITH
SPC/S MORNING UPDATE...BELIEVE STRONGEST OF THE CONVECTION SHOULD BE
FOCUSED OVER THE SOUTHERN HALF OF THE FORECAST AREA (ALONG AND SOUTH
OF I-70) AS THE DISTURBANCE TRACKS INTO THE SRN OHIO VALLEY THROUGH
THIS EVENING. WILL CONTINUE TO CARRY SCATTERED TO LIKELY TSTM POPS
IN THE FORECAST (ESP AROUND AND S OF I-70) BUT ADDED THE THREAT OF
SVR WX (FOR THE SLIGHT RISK AREA) INCLUDING LARGE HAIL AND VERY
HEAVY RAINFALL AS THE MAIN THREATS. AS MENTIONED EARLIER...BL SHEAR
VALUES REMAIN WEAK...HOWEVER WITH WBZERO VALUES ABOVE 8KFT AND STEEP
LAPSE RATES PRESENT...A FEW OF THE MORE INTENSE STORMS WILL BE
CAPABLE OF PRODUCING LARGE HAIL AND POSSIBLY SOME GUSTY WINDS.
BULK OF THE TSTM...AND ESPECIALLY THE SEVERE POTENTIAL WILL DIMINISH
LATER THIS EVENING. CHANCES CONVECTION WILL CONTINUE OVERNIGHT AS
AFOREMENTIONED UPPER WAVE DRIFTS EAST THROUGH THE OHIO VALLEY. FOCUS
FOR HIGHEST POPS WILL REMAIN SOUTH OF I-70 THROUGH THE OVERNIGHT
HOURS...LOWERING CHANCES EVEN MORE AFTER MIDNIGHT AS WEAK RIDGING
ALOFT BUILDS BACK INTO THE REGION BEHIND THE FEATURE. A MOS BLEND
SEEMS REASONABLE TO LOW TONIGHT RANGING FROM THE UPPER 50S TO AROUND
60.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FORECAST PATTERN REMAINS UNCHANGED FOR THE REST OF THE WEEK AND
ACTUALLY INTO NEXT WEEK. ABOVE NORMAL/NEAR RECORD HIGHS WILL
CONTINUE DURING THE PERIOD AND WE WILL ALSO HAVE ON AND OFF CHANCES
FOR THUNDERSTORMS THROUGH AT LEAST EARLY NEXT WEEK. FORECAST
CHALLENGE IS TRYING TO DECIPHER BETWEEN THE DRY AND WET PERIODS.
LUCKILY ALL GUIDANCE IS SIMILAR IN HANDLING OF MAIN FEATURES THROUGH
THE PERIOD.
AGREE WITH PREVIOUS FORECAST THINKING AND ACTUALLY HAVE LOWERED POPS
EVEN MORE FOR FRIDAY FROM PREVIOUS FORECAST AS CONFIDENCE IS LOWER
IN MORE SUBSTANTIAL PRECIP COVERAGE. WINDS AND OVERALL FORCING ALOFT
WEAKEN AS HEIGHTS RISE AGAIN IN RESPONSE TO THE EXPANSION OF THE
UPPER RIDGE...WITH CONVECTIVE DEVELOPMENT LIKELY TO BE LARGELY
DEPENDENT ON AVAILABLE INSTABILITY. WILL AGAIN CARRY HIGHEST POPS
(30-40 PERCENT) OVER THE SOUTH/SOUTHEAST COUNTIES...DUE TO THEIR
CLOSES PROXIMITY TO DEPARTING UPPER WAVE. OTHERWISE ONLY ANTICIPATE
ISOLATED CONVECTION NORTH OF I-70.
THERE IS MORE SUBSTANTIAL POTENTIAL FOR CONVECTION LATER IN THE DAY
SATURDAY AS LOW PRESSURE PULLS OUT INTO THE CENTRAL PLAINS. GUIDANCE
SHOWS A STRONGER SHORT WAVE ALOFT OUT OF THE SOUTHERN PLAINS
REACHING THE REGION DURING THIS TIME. THIS FEATURE SHOULD SPURN
INCREASED CONVECTION...ESPECIALLY IF THE FEATURE ARRIVES DURING PEAK
HEATING IN THE LATE AFTERNOON. HAVE BUMPED UP POPS TO 40 PERCENT
SCATTERED DURING THE AFTERNOON AND EVENING AND LASTING THROUGH
SUNDAY. HEAVY RAIN AND LOCALIZED FLOODING MAY BECOME AN ISSUE WITH
PRECIP WATER VALUES AT OR ABOVE 1 INCH FOR MUCH OF THE PERIOD.
IN TERMS OF TEMPERATURES...POTENTIAL FOR RECORD BREAKING HIGHS AT
IND WILL CONTINUE THROUGH THE PERIOD. WITH NO APPRECIABLE CHANGE IN
THE AIRMASS...EXPECT HIGHS TO BE VERY SIMILAR FRIDAY THROUGH SUNDAY.
CONTINUING THE TREND OF RUNNING A FEW DEGREES ABOVE MOS AS HIGHS IN
THE UPPER 70S AND LOWER 80S ARE LIKELY THROUGH THE PERIOD. RECORD HIGHS
AT IND ARE 79 FROM 1945 ON FRIDAY AND 76 FROM 1894 ON SATURDAY.
AND 76 ON SUNDAY FROM 1903. LOWS WILL REMAIN NEAR 60 THROUGH THE
PERIOD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
EARLY IN THE LONG TERM THINK HIGH TEMPERATURES ARE TOO LOW BASED ON
RECENT TRENDS AND FORECAST 850 MB TEMPERATURES THAT ARE SIMILAR TO
WHAT/S BEEN SEEN THE PAST FEW DAYS. THEREFORE INCREASED
INITIALIZATION BY AT LEAST A FEW DEGREES FOR HIGHS FROM MONDAY
THROUGH THURSDAY. ALSO WITH UPPER RIDGE AXIS BUILDING OVER THE AREA
EARLY IN THE LONG TERM REMOVED THE SLIGHT TO LOW CHANCE POPS FROM
SUNDAY NIGHT AND MONDAY AND INSTEAD EXPECT TO SEE DRY WEATHER UNTIL
AT LEAST WEDNESDAY.
MODELS ARE SHOWING A DECENT BIT OF VARIABILITY IN THE LATTER HALF OF
THE LONG TERM IN THE LARGE SCALE PATTERN. WHILE GFS/ECMWF/GEFS SEEM
TO AGREE ON A CUT OFF LOW DEVELOPING OUT OF THE WESTERN TROUGH THERE
IS A HIGH AMOUNT OF VARIABILITY ON WHERE THIS HAPPENS AND HOW MUCH
RIDGING REMAINS OVER CENTRAL INDIANA AND FOR HOW LONG. WITH THIS IN
MIND WILL STICK CLOSE TO INITIALIZATION FOR POPS WEDNESDAY NIGHT AND
THURSDAY.
&&
.AVIATION /DISCUSSION FOR THE 21Z IND TAF UPDATE/...
RADAR TRENDS INDICATE AN AREA OF SHOWERS AND THUNDERSTORMS OVER
SOUTH CENTRAL INDIANA PUSHING NORTHEAST. DISTANCE SPEED PROJECTION
INDICATE THAT THESE FEATURES SHOULD PUSH NEAR THE IND TAF SITE IN
THE NEXT 1-2 HOURS. BRIEF MVFR CONDITIONS ALONG WITH LIGHTING WILL
BE POSSIBLE AS THE STORMS PASS.
LITTLE CHANGE TO THE LATER PARTS OF THE FORECAST AS LOSS OF
DAYTIME HEATING IS EXPECTED TO RESULT IN DIMINISHING TSRA.
/DISCUSSION FOR 151800Z TAF ISSUANCE/...
SOME WIND GUSTS OF AROUND 20 KTS OUT OF 220 COULD BE SEEN THIS
AFTERNOON ACCORDING TO RUC SOUNDINGS.
INSTABILITY IS INCREASING AT THE SITES AND RAPID UPDATE MODELS ARE
STILL SHOWING CONVECTIVE DEVELOPMENT ACROSS PARTS OF THE AREA BY
19Z. WILL USE THIS AS A START FOR THE INCLUSION OF VCTS BUT WILL NOT
DROP CATEGORY AT ANY SITE BESIDES KBMG AS NATURE OF CONVECTION WILL
BE POP UP AND SCATTERED. KBMG IS THE EXCEPTION TO THIS AS A LINE OF
STORMS ACROSS SOUTHERN ILLINOIS AT 1630Z IS HEADED TOWARD KBMG...AND
HAVE TIMED THIS LINE IN AND INCLUDED TEMPO THUNDER AND MVFR FOR A
COUPLE HOURS AROUND THE LINES ARRIVAL. CURRENT MOVEMENT AND TIMING
HAS THIS LINE MISSING THE REST OF THE SITES.
SHOULD SEE THIS ROUND OF CONVECTION MOVING OUT OF THE AREA BY AROUND
0-1Z. COULD SEE SOME ELEVATED ACTIVITY DEVELOP OVERNIGHT BUT THINK
LIKELIHOOD IS LOW ENOUGH TO LEAVE OUT. FORECAST SOUNDINGS DO SHOW A
STRONG INVERSION DEVELOPING OVERNIGHT AND HAVE CONCERNS THAT THIS
COULD LEAD TO LOWER VISIBILITIES...BUT WITH SOME CLOUD COVER...SOME
MIXING...AND CHANCES FOR PRECIP JUST DON/T FEEL CONFIDENT ENOUGH TO
GO LOWER THAN MVFR AT THIS TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....CP
AVIATION...CP/JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
209 PM EDT THU MAR 15 2012
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A BROAD UPPER LEVEL RIDGE WILL PERSIST ACROSS THE EASTERN PART OF
THE COUNTRY INTO THE MIDDLE OF NEXT WEEK...WITH TEMPERATURES
CONTINUING AT WELL ABOVE NORMAL AND NEAR RECORD LEVELS. SEVERAL
DISTURBANCES ALOFT WILL PROGRESS THROUGH THE UPPER RIDGE...PROVIDING
PERIODIC CHANCES FOR THUNDERSTORMS OVER CENTRAL INDIANA THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF THIS AFTERNOON INTO TONIGHT/...
AS OF 130 PM THIS AFTERNOON...ALL EYES TURN TO THE MCS MOVING TOWARD
THE SW FORECAST AREA FROM SE MO/SW IL. THIS FEATURE IS ASSOCIATED
WITH AN UPPER VORT MAX AND ALL SHORT TERM GUIDANCE AGREES ON
MOVING THIS FEATURE THROUGH THE OH VALLEY LATE THIS AFTERNOON AND
EVENING. SCATTERED CONVECTION WILL MOVE INTO CWA IN THE NEXT HOUR OR
SO AND THEN SPREAD QUICKLY AS DAYTIME HEATING WILL HAVE ALLOWED MANY
LOCATIONS TO REACH THEIR CONVECTIVE TEMPERATURES ACROSS THE REST OF
CENTRAL INDIANA AND THE ENTIRE OHIO VALLEY REMAINS UNDER A MOIST AND
UNSTABLE AIRMASS. THE PRESENCE OF A WEAK FRONTAL BOUNDARY TO THE
NORTH WILL LIKELY HAVE SOME INFLUENCE ON CONVECTION BUT STILL
APPEARS THE VORT MAX/MCS WILL BE THE MAIN DRIVING FEATURE
RESPONSIBLE FOR INDUCING CONVECTION OVER THE CWA AND THE OHIO VALLEY
BY LATE THIS AFTERNOON AND INTO THE EVENING.
EVEN THOUGH THE SLIGHT RISK HAS BEEN EXPANDED FARTHER NORTHWARD WITH
SPC/S MORNING UPDATE...BELIEVE STRONGEST OF THE CONVECTION SHOULD BE
FOCUSED OVER THE SOUTHERN HALF OF THE FORECAST AREA (ALONG AND SOUTH
OF I-70) AS THE DISTURBANCE TRACKS INTO THE SRN OHIO VALLEY THROUGH
THIS EVENING. WILL CONTINUE TO CARRY SCATTERED TO LIKELY TSTM POPS
IN THE FORECAST (ESP AROUND AND S OF I-70) BUT ADDED THE THREAT OF
SVR WX (FOR THE SLIGHT RISK AREA) INCLUDING LARGE HAIL AND VERY
HEAVY RAINFALL AS THE MAIN THREATS. AS MENTIONED EARLIER...BL SHEAR
VALUES REMAIN WEAK...HOWEVER WITH WBZERO VALUES ABOVE 8KFT AND STEEP
LAPSE RATES PRESENT...A FEW OF THE MORE INTENSE STORMS WILL BE
CAPABLE OF PRODUCING LARGE HAIL AND POSSIBLY SOME GUSTY WINDS.
BULK OF THE TSTM...AND ESPECIALLY THE SEVERE POTENTIAL WILL DIMINISH
LATER THIS EVENING. CHANCES CONVECTION WILL CONTINUE OVERNIGHT AS
AFOREMENTIONED UPPER WAVE DRIFTS EAST THROUGH THE OHIO VALLEY. FOCUS
FOR HIGHEST POPS WILL REMAIN SOUTH OF I-70 THROUGH THE OVERNIGHT
HOURS...LOWERING CHANCES EVEN MORE AFTER MIDNIGHT AS WEAK RIDGING
ALOFT BUILDS BACK INTO THE REGION BEHIND THE FEATURE. A MOS BLEND
SEEMS REASONABLE TO LOW TONIGHT RANGING FROM THE UPPER 50S TO AROUND
60.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FORECAST PATTERN REMAINS UNCHANGED FOR THE REST OF THE WEEK AND
ACTUALLY INTO NEXT WEEK. ABOVE NORMAL/NEAR RECORD HIGHS WILL
CONTINUE DURING THE PERIOD AND WE WILL ALSO HAVE ON AND OFF CHANCES
FOR THUNDERSTORMS THROUGH AT LEAST EARLY NEXT WEEK. FORECAST
CHALLENGE IS TRYING TO DECIPHER BETWEEN THE DRY AND WET PERIODS.
LUCKILY ALL GUIDANCE IS SIMILAR IN HANDLING OF MAIN FEATURES THROUGH
THE PERIOD.
AGREE WITH PREVIOUS FORECAST THINKING AND ACTUALLY HAVE LOWERED POPS
EVEN MORE FOR FRIDAY FROM PREVIOUS FORECAST AS CONFIDENCE IS LOWER
IN MORE SUBSTANTIAL PRECIP COVERAGE. WINDS AND OVERALL FORCING ALOFT
WEAKEN AS HEIGHTS RISE AGAIN IN RESPONSE TO THE EXPANSION OF THE
UPPER RIDGE...WITH CONVECTIVE DEVELOPMENT LIKELY TO BE LARGELY
DEPENDENT ON AVAILABLE INSTABILITY. WILL AGAIN CARRY HIGHEST POPS
(30-40 PERCENT) OVER THE SOUTH/SOUTHEAST COUNTIES...DUE TO THEIR
CLOSES PROXIMITY TO DEPARTING UPPER WAVE. OTHERWISE ONLY ANTICIPATE
ISOLATED CONVECTION NORTH OF I-70.
THERE IS MORE SUBSTANTIAL POTENTIAL FOR CONVECTION LATER IN THE DAY
SATURDAY AS LOW PRESSURE PULLS OUT INTO THE CENTRAL PLAINS. GUIDANCE
SHOWS A STRONGER SHORT WAVE ALOFT OUT OF THE SOUTHERN PLAINS
REACHING THE REGION DURING THIS TIME. THIS FEATURE SHOULD SPURN
INCREASED CONVECTION...ESPECIALLY IF THE FEATURE ARRIVES DURING PEAK
HEATING IN THE LATE AFTERNOON. HAVE BUMPED UP POPS TO 40 PERCENT
SCATTERED DURING THE AFTERNOON AND EVENING AND LASTING THROUGH
SUNDAY. HEAVY RAIN AND LOCALIZED FLOODING MAY BECOME AN ISSUE WITH
PRECIP WATER VALUES AT OR ABOVE 1 INCH FOR MUCH OF THE PERIOD.
IN TERMS OF TEMPERATURES...POTENTIAL FOR RECORD BREAKING HIGHS AT
IND WILL CONTINUE THROUGH THE PERIOD. WITH NO APPRECIABLE CHANGE IN
THE AIRMASS...EXPECT HIGHS TO BE VERY SIMILAR FRIDAY THROUGH SUNDAY.
CONTINUING THE TREND OF RUNNING A FEW DEGREES ABOVE MOS AS HIGHS IN
THE UPPER 70S AND LOWER 80S ARE LIKELY THROUGH THE PERIOD. RECORD HIGHS
AT IND ARE 79 FROM 1945 ON FRIDAY AND 76 FROM 1894 ON SATURDAY.
AND 76 ON SUNDAY FROM 1903. LOWS WILL REMAIN NEAR 60 THROUGH THE
PERIOD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
EARLY IN THE LONG TERM THINK HIGH TEMPERATURES ARE TOO LOW BASED ON
RECENT TRENDS AND FORECAST 850 MB TEMPERATURES THAT ARE SIMILAR TO
WHAT/S BEEN SEEN THE PAST FEW DAYS. THEREFORE INCREASED
INITIALIZATION BY AT LEAST A FEW DEGREES FOR HIGHS FROM MONDAY
THROUGH THURSDAY. ALSO WITH UPPER RIDGE AXIS BUILDING OVER THE AREA
EARLY IN THE LONG TERM REMOVED THE SLIGHT TO LOW CHANCE POPS FROM
SUNDAY NIGHT AND MONDAY AND INSTEAD EXPECT TO SEE DRY WEATHER UNTIL
AT LEAST WEDNESDAY.
MODELS ARE SHOWING A DECENT BIT OF VARIABILITY IN THE LATTER HALF OF
THE LONG TERM IN THE LARGE SCALE PATTERN. WHILE GFS/ECMWF/GEFS SEEM
TO AGREE ON A CUT OFF LOW DEVELOPING OUT OF THE WESTERN TROUGH THERE
IS A HIGH AMOUNT OF VARIABILITY ON WHERE THIS HAPPENS AND HOW MUCH
RIDGING REMAINS OVER CENTRAL INDIANA AND FOR HOW LONG. WITH THIS IN
MIND WILL STICK CLOSE TO INITIALIZATION FOR POPS WEDNESDAY NIGHT AND
THURSDAY.
&&
.AVIATION /DISCUSSION FOR 151800Z TAF ISSUANCE/...
SOME WIND GUSTS OF AROUND 20 KTS OUT OF 220 COULD BE SEEN THIS
AFTERNOON ACCORDING TO RUC SOUNDINGS.
INSTABILITY IS INCREASING AT THE SITES AND RAPID UPDATE MODELS ARE
STILL SHOWING CONVECTIVE DEVELOPMENT ACROSS PARTS OF THE AREA BY
19Z. WILL USE THIS AS A START FOR THE INCLUSION OF VCTS BUT WILL NOT
DROP CATEGORY AT ANY SITE BESIDES KBMG AS NATURE OF CONVECTION WILL
BE POP UP AND SCATTERED. KBMG IS THE EXCEPTION TO THIS AS A LINE OF
STORMS ACROSS SOUTHERN ILLINOIS AT 1630Z IS HEADED TOWARD KBMG...AND
HAVE TIMED THIS LINE IN AND INCLUDED TEMPO THUNDER AND MVFR FOR A
COUPLE HOURS AROUND THE LINES ARRIVAL. CURRENT MOVEMENT AND TIMING
HAS THIS LINE MISSING THE REST OF THE SITES.
SHOULD SEE THIS ROUND OF CONVECTION MOVING OUT OF THE AREA BY AROUND
0-1Z. COULD SEE SOME ELEVATED ACTIVITY DEVELOP OVERNIGHT BUT THINK
LIKELIHOOD IS LOW ENOUGH TO LEAVE OUT. FORECAST SOUNDINGS DO SHOW A
STRONG INVERSION DEVELOPING OVERNIGHT AND HAVE CONCERNS THAT THIS
COULD LEAD TO LOWER VISIBILITIES...BUT WITH SOME CLOUD COVER...SOME
MIXING...AND CHANCES FOR PRECIP JUST DON/T FEEL CONFIDENT ENOUGH TO
GO LOWER THAN MVFR AT THIS TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....CP
AVIATION...CP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
202 PM EDT THU MAR 15 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED
BELOW.
&&
.SYNOPSIS...
A BROAD UPPER LEVEL RIDGE WILL PERSIST ACROSS THE EASTERN PART OF
THE COUNTRY INTO THE MIDDLE OF NEXT WEEK...WITH TEMPERATURES
CONTINUING AT WELL ABOVE NORMAL AND NEAR RECORD LEVELS. SEVERAL
DISTURBANCES ALOFT WILL PROGRESS THROUGH THE UPPER RIDGE...PROVIDING
PERIODIC CHANCES FOR THUNDERSTORMS OVER CENTRAL INDIANA THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF THIS AFTERNOON INTO TONIGHT/...
AS OF 130 PM THIS AFTERNOON...ALL EYES TURN TO THE MCS MOVING TOWARD
THE SW FORECAST AREA FROM SE MO/SW IL. THIS FEATURE IS ASSOCIATED
WITH AN UPPER VORT MAX AND ALL SHORT TERM GUIDANCE AGREES ON
MOVING THIS FEATURE THROUGH THE OH VALLEY LATE THIS AFTERNOON AND
EVENING. SCATTERED CONVECTION WILL MOVE INTO CWA IN THE NEXT HOUR OR
SO AND THEN SPREAD QUICKLY AS DAYTIME HEATING WILL HAVE ALLOWED MANY
LOCATIONS TO REACH THEIR CONVECTIVE TEMPERATURES ACROSS THE REST OF
CENTRAL INDIANA AND THE ENTIRE OHIO VALLEY REMAINS UNDER A MOIST AND
UNSTABLE AIRMASS. THE PRESENCE OF A WEAK FRONTAL BOUNDARY TO THE
NORTH WILL LIKELY HAVE SOME INFLUENCE ON CONVECTION BUT STILL
APPEARS THE VORT MAX/MCS WILL BE THE MAIN DRIVING FEATURE
RESPONSIBLE FOR INDUCING CONVECTION OVER THE CWA AND THE OHIO VALLEY
BY LATE THIS AFTERNOON AND INTO THE EVENING.
EVEN THOUGH THE SLIGHT RISK HAS BEEN EXPANDED FARTHER NORTHWARD WITH
SPC/S MORNING UPDATE...BELIEVE STRONGEST OF THE CONVECTION SHOULD BE
FOCUSED OVER THE SOUTHERN HALF OF THE FORECAST AREA (ALONG AND SOUTH
OF I-70) AS THE DISTURBANCE TRACKS INTO THE SRN OHIO VALLEY THROUGH
THIS EVENING. WILL CONTINUE TO CARRY SCATTERED TO LIKELY TSTM POPS
IN THE FORECAST (ESP AROUND AND S OF I-70) BUT ADDED THE THREAT OF
SVR WX (FOR THE SLIGHT RISK AREA) INCLUDING LARGE HAIL AND VERY
HEAVY RAINFALL AS THE MAIN THREATS. AS MENTIONED EARLIER...BL SHEAR
VALUES REMAIN WEAK...HOWEVER WITH WBZERO VALUES ABOVE 8KFT AND STEEP
LAPSE RATES PRESENT...A FEW OF THE MORE INTENSE STORMS WILL BE
CAPABLE OF PRODUCING LARGE HAIL AND POSSIBLY SOME GUSTY WINDS.
BULK OF THE TSTM...AND ESPECIALLY THE SEVERE POTENTIAL WILL DIMINISH
LATER THIS EVENING. CHANCES CONVECTION WILL CONTINUE OVERNIGHT AS
AFOREMENTIONED UPPER WAVE DRIFTS EAST THROUGH THE OHIO VALLEY. FOCUS
FOR HIGHEST POPS WILL REMAIN SOUTH OF I-70 THROUGH THE OVERNIGHT
HOURS...LOWERING CHANCES EVEN MORE AFTER MIDNIGHT AS WEAK RIDGING
ALOFT BUILDS BACK INTO THE REGION BEHIND THE FEATURE. A MOS BLEND
SEEMS REASONABLE TO LOW TONIGHT RANGING FROM THE UPPER 50S TO AROUND
60.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FORECAST PATTERN REMAINS UNCHANGED FOR THE REST OF THE WEEK AND
ACTUALLY INTO NEXT WEEK. ABOVE NORMAL/NEAR RECORD HIGHS WILL
CONTINUE DURING THE PERIOD AND WE WILL ALSO HAVE ON AND OFF CHANCES
FOR THUNDERSTORMS THROUGH AT LEAST EARLY NEXT WEEK. FORECAST
CHALLENGE IS TRYING TO DECIPHER BETWEEN THE DRY AND WET PERIODS.
LUCKILY ALL GUIDANCE IS SIMILAR IN HANDLING OF MAIN FEATURES THROUGH
THE PERIOD.
AGREE WITH PREVIOUS FORECAST THINKING AND ACTUALLY HAVE LOWERED POPS
EVEN MORE FOR FRIDAY FROM PREVIOUS FORECAST AS CONFIDENCE IS LOWER
IN MORE SUBSTANTIAL PRECIP COVERAGE. WINDS AND OVERALL FORCING ALOFT
WEAKEN AS HEIGHTS RISE AGAIN IN RESPONSE TO THE EXPANSION OF THE
UPPER RIDGE...WITH CONVECTIVE DEVELOPMENT LIKELY TO BE LARGELY
DEPENDENT ON AVAILABLE INSTABILITY. WILL AGAIN CARRY HIGHEST POPS
(30-40 PERCENT) OVER THE SOUTH/SOUTHEAST COUNTIES...DUE TO THEIR
CLOSES PROXIMITY TO DEPARTING UPPER WAVE. OTHERWISE ONLY ANTICIPATE
ISOLATED CONVECTION NORTH OF I-70.
THERE IS MORE SUBSTANTIAL POTENTIAL FOR CONVECTION LATER IN THE DAY
SATURDAY AS LOW PRESSURE PULLS OUT INTO THE CENTRAL PLAINS. GUIDANCE
SHOWS A STRONGER SHORT WAVE ALOFT OUT OF THE SOUTHERN PLAINS
REACHING THE REGION DURING THIS TIME. THIS FEATURE SHOULD SPURN
INCREASED CONVECTION...ESPECIALLY IF THE FEATURE ARRIVES DURING PEAK
HEATING IN THE LATE AFTERNOON. HAVE BUMPED UP POPS TO 40 PERCENT
SCATTERED DURING THE AFTERNOON AND EVENING AND LASTING THROUGH
SUNDAY. HEAVY RAIN AND LOCALIZED FLOODING MAY BECOME AN ISSUE WITH
PRECIP WATER VALUES AT OR ABOVE 1 INCH FOR MUCH OF THE PERIOD.
IN TERMS OF TEMPERATURES...POTENTIAL FOR RECORD BREAKING HIGHS AT
IND WILL CONTINUE THROUGH THE PERIOD. WITH NO APPRECIABLE CHANGE IN
THE AIRMASS...EXPECT HIGHS TO BE VERY SIMILAR FRIDAY THROUGH SUNDAY.
CONTINUING THE TREND OF RUNNING A FEW DEGREES ABOVE MOS AS HIGHS IN
THE UPPER 70S AND LOWER 80S ARE LIKELY THROUGH THE PERIOD. RECORD HIGHS
AT IND ARE 79 FROM 1945 ON FRIDAY AND 76 FROM 1894 ON SATURDAY.
AND 76 ON SUNDAY FROM 1903. LOWS WILL REMAIN NEAR 60 THROUGH THE
PERIOD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ENSEMBLES IN GENERAL AGREEMENT IN KEEPING STRONG UPPER RIDGING
ACROSS THE AREA INTO THE MIDDLE OF NEXT WEEK. THERE ARE SOME
DIFFERENCES AMONG THE MEMBERS WITH RESPECT TO HOW FAR THE WESTERN
TROUGH WILL EJECT BY THE MIDDLE OF NEXT WEEK...BUT THE FASTEST
MEMBERS BRING THE TROUGH ONLY INTO THE ARKLATEX REGION BY NEXT
WEDNESDAY WHILE MOST OF THE OTHER MEMBERS KEEP THIS SYSTEM FARTHER
WEST OVER WESTERN TEXAS OR THE SOUTHERN ROCKIES. BOTTOM LINE IS THAT
IT APPEARS PRECIPITATION THREAT FOR EARLY NEXT WEEK CONTINUES TO
DIMINISH...WITH LITTLE ENSEMBLE SUPPORT FOR A POP BEYOND SUNDAY OR
MONDAY. WILL KEEP CHANCE POPS IN THE FORECAST FOR SUNDAY AND
MONDAY...AND GO DRY TUESDAY AND WEDNESDAY. MAY BE ABLE TO TAKE OUT
POPS FOR MONDAY AS WELL AT SOME POINT IN THE FUTURE IF DRIER TRENDS
CONTINUE. WELL ABOVE NORMAL TEMPERATURES WILL PERSIST THROUGHOUT
THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 151800Z TAF ISSUANCE/...
SOME WIND GUSTS OF AROUND 20 KTS OUT OF 220 COULD BE SEEN THIS
AFTERNOON ACCORDING TO RUC SOUNDINGS.
INSTABILITY IS INCREASING AT THE SITES AND RAPID UPDATE MODELS ARE
STILL SHOWING CONVECTIVE DEVELOPMENT ACROSS PARTS OF THE AREA BY
19Z. WILL USE THIS AS A START FOR THE INCLUSION OF VCTS BUT WILL NOT
DROP CATEGORY AT ANY SITE BESIDES KBMG AS NATURE OF CONVECTION WILL
BE POP UP AND SCATTERED. KBMG IS THE EXCEPTION TO THIS AS A LINE OF
STORMS ACROSS SOUTHERN ILLINOIS AT 1630Z IS HEADED TOWARD KBMG...AND
HAVE TIMED THIS LINE IN AND INCLUDED TEMPO THUNDER AND MVFR FOR A
COUPLE HOURS AROUND THE LINES ARRIVAL. CURRENT MOVEMENT AND TIMING
HAS THIS LINE MISSING THE REST OF THE SITES.
SHOULD SEE THIS ROUND OF CONVECTION MOVING OUT OF THE AREA BY AROUND
0-1Z. COULD SEE SOME ELEVATED ACTIVITY DEVELOP OVERNIGHT BUT THINK
LIKELIHOOD IS LOW ENOUGH TO LEAVE OUT. FORECAST SOUNDINGS DO SHOW A
STRONG INVERSION DEVELOPING OVERNIGHT AND HAVE CONCERNS THAT THIS
COULD LEAD TO LOWER VISIBILITIES...BUT WITH SOME CLOUD COVER...SOME
MIXING...AND CHANCES FOR PRECIP JUST DON/T FEEL CONFIDENT ENOUGH TO
GO LOWER THAN MVFR AT THIS TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....JAS
AVIATION...CP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1245 PM EDT THU MAR 15 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
A BROAD UPPER LEVEL RIDGE WILL PERSIST ACROSS THE EASTERN PART OF
THE COUNTRY INTO THE MIDDLE OF NEXT WEEK...WITH TEMPERATURES
CONTINUING AT WELL ABOVE NORMAL AND NEAR RECORD LEVELS. SEVERAL
DISTURBANCES ALOFT WILL PROGRESS THROUGH THE UPPER RIDGE...PROVIDING
PERIODIC CHANCES FOR THUNDERSTORMS OVER CENTRAL INDIANA THROUGH THE
WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
AS OF 1030AM...THE EARLY POCKETS OF CONVECTION (ASSOCIATED WITH AN
UPPER WAVE) HAVE SINCE MOVED EAST/SOUTHEAST AND OUT OF THE CWA.
OUR EYES THEN TURN TO THIS AFTERNOON AND EVENING AS A VORT MAX
CURRENTLY LOCATED OVER LOWER MO AND SW IL MOVES EASTWARD TOWARD THE
OH VALLEY. SCATTERED CONVECTION LIKELY TO DEVELOP INTO THE FORECAST
AREA AS THE DAY PROGRESSES AS THE ENTIRE OHIO VALLEY REMAINS UNDER A
MOIST AND UNSTABLE AIRMASS. THE PRESENCE OF A WEAK FRONTAL BOUNDARY
TO THE NORTH WILL LIKELY HAVE SOME INFLUENCE ON CONVECTION BUT STILL
APPEARS THE UPPER LEVEL DISTURBANCE WILL BE THE MAIN DRIVING
FEATURE RESPONSIBLE FOR INDUCING CONVECTION OVER THE CWA AND THE
OHIO VALLEY BY THE AFTERNOON.
EVEN THOUGH THE SLIGHT RISK HAS BEEN EXPANDED FARTHER NORTHWARD
WITH SPC/S MORNING UPDATE...CONVECTION SHOULD BE ESPECIALLY
FOCUSED OVER THE SOUTHERN HALF OF THE FORECAST AREA AS THE DISTURBANCE
TRACKS INTO THE SRN OHIO VALLEY THROUGH THIS EVENING. WILL
CONTINUE TO CARRY SCATTERED TSTMS IN THE FORECAST BUT ADDED THE
THREAT OF SVR WX (FOR THE SLIGHT RISK AREA) INCLUDING LARGE HAIL
AND VERY HEAVY RAINFALL AS THE MAIN THREATS. WITH BL SHEAR VALUES
REMAINING WEAK..STORMS SHOULD REMAIN LARGELY SUBSEVERE AND DEVELOP
INTO MULTICELLULAR CLUSTERS WITH BRIEF HEAVY RAINERS. HOWEVER WITH
WBZERO VALUES NEAR 8KFT AND STEEP LAPSE RATES PRESENT...A FEW OF
THE MORE INTENSE STORMS WILL BE CAPABLE OF PRODUCING HAIL AND
POSSIBLY SOME GUSTY WINDS.
TEMPS...THE WARM START THIS MORNING AND EXPECTATION FOR SUNSHINE
THROUGH MIDDAY WILL ONCE AGAIN ENABLE TEMPS TO RISE TO AROUND 80
DEGREES THIS AFTERNOON. POTENTIAL FOR MORE CLOUDS AND PRECIP BY THIS
AFTERNOON IN SOUTHERN COUNTIES MAY HAMPER RISES A BIT...BUT
OTHERWISE SEE NO REASON TO GO A FEW DEGREES ABOVE MOS ONCE AGAIN.
STRONG POSSIBILITY THAT RECORD HIGH OF 77 FROM 1977 AT IND IS
REACHED AGAIN TODAY.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON PRECIP CHANCES AND TEMPS AS UPPER LEVEL
DISTURBANCES CONTINUE TO TRACK THROUGH THE OHIO VALLEY IN BROAD
SOUTHWEST FLOW REGIME. ALL GUIDANCE IS SIMILAR IN HANDLING OF MAIN
FEATURES THROUGH THE PERIOD.
SCATTERED CONVECTION WILL CONTINUE THIS EVENING AS AFOREMENTIONED
UPPER WAVE DRIFTS EAST THROUGH THE OHIO VALLEY. FOCUS FOR HIGHEST
POPS WILL REMAIN SOUTH OF I-70 THROUGH THE EVENING HOURS...LOWERING
AFTER MIDNIGHT AS WEAK RIDGING ALOFT BUILDS BACK INTO THE REGION
BEHIND THE FEATURE. HAVE LOWERED POPS FOR FRIDAY FROM PREVIOUS
FORECAST AS CONFIDENCE IS LOWER IN MORE SUBSTANTIAL PRECIP COVERAGE.
WINDS AND OVERALL FORCING ALOFT WEAKEN AS HEIGHTS RISE AGAIN IN
RESPONSE TO THE EXPANSION OF THE UPPER RIDGE...WITH CONVECTIVE
DEVELOPMENT LIKELY TO BE LARGELY DEPENDENT ON AVAILABLE INSTABILITY.
WILL ONCE AGAIN CARRY HIGHEST 30-40 POPS OVER SOUTHEAST COUNTIES IN
CLOSEST PROXIMITY TO DEPARTING UPPER WAVE. OTHERWISE...ANTICIPATE
ONLY ISOLATED CONVECTION.
POTENTIAL FOR MORE SUBSTANTIAL CONVECTIVE COVERAGE ON SATURDAY AS
LOW PRESSURE PULLS OUT INTO THE CENTRAL PLAINS. MODEL GUIDANCE
CONSISTENT IN BRINGING A STRONGER SHORT WAVE ALOFT OUT OF THE
SOUTHERN PLAINS AND INTO THE REGION BY SATURDAY AFTERNOON AND
EVENING. THIS FEATURE SHOULD SPURN INCREASED CONVECTION...ESPECIALLY
IF THE FEATURE ARRIVES DURING PEAK HEATING IN THE LATE AFTERNOON.
HAVE BUMPED UP POPS DURING THE AFTERNOON AND EVENING. HEAVY RAIN AND
LOCALIZED FLOODING MAY BECOME AN ISSUE WITH PRECIP WATER VALUES AT
OR ABOVE 1 INCH FOR MUCH OF THE PERIOD.
TEMPS...POTENTIAL FOR RECORD BREAKING HIGHS AT IND WILL CONTINUE
THROUGH THE PERIOD. WITH NO APPRECIABLE CHANGE IN THE AIRMASS...
EXPECT HIGHS TO BE VERY SIMILAR FRIDAY AND SATURDAY. CONTINUING THE
TREND OF RUNNING A FEW DEGREES ABOVE MOS AS HIGHS IN THE UPPER 70S
AND LOWER 80S ARE LIKELY BOTH DAYS. RECORD HIGHS AT IND ARE 79 FROM
1945 ON FRIDAY AND 76 FROM 1894 ON SATURDAY. LOWS WILL REMAIN NEAR
60 THROUGH THE PERIOD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ENSEMBLES IN GENERAL AGREEMENT IN KEEPING STRONG UPPER RIDGING
ACROSS THE AREA INTO THE MIDDLE OF NEXT WEEK. THERE ARE SOME
DIFFERENCES AMONG THE MEMBERS WITH RESPECT TO HOW FAR THE WESTERN
TROUGH WILL EJECT BY THE MIDDLE OF NEXT WEEK...BUT THE FASTEST
MEMBERS BRING THE TROUGH ONLY INTO THE ARKLATEX REGION BY NEXT
WEDNESDAY WHILE MOST OF THE OTHER MEMBERS KEEP THIS SYSTEM FARTHER
WEST OVER WESTERN TEXAS OR THE SOUTHERN ROCKIES. BOTTOM LINE IS THAT
IT APPEARS PRECIPITATION THREAT FOR EARLY NEXT WEEK CONTINUES TO
DIMINISH...WITH LITTLE ENSEMBLE SUPPORT FOR A POP BEYOND SUNDAY OR
MONDAY. WILL KEEP CHANCE POPS IN THE FORECAST FOR SUNDAY AND
MONDAY...AND GO DRY TUESDAY AND WEDNESDAY. MAY BE ABLE TO TAKE OUT
POPS FOR MONDAY AS WELL AT SOME POINT IN THE FUTURE IF DRIER TRENDS
CONTINUE. WELL ABOVE NORMAL TEMPERATURES WILL PERSIST THROUGHOUT
THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 151800Z TAF ISSUANCE/...
SOME WIND GUSTS OF AROUND 20 KTS OUT OF 220 COULD BE SEEN THIS
AFTERNOON ACCORDING TO RUC SOUNDINGS.
INSTABILITY IS INCREASING AT THE SITES AND RAPID UPDATE MODELS ARE
STILL SHOWING CONVECTIVE DEVELOPMENT ACROSS PARTS OF THE AREA BY
19Z. WILL USE THIS AS A START FOR THE INCLUSION OF VCTS BUT WILL NOT
DROP CATEGORY AT ANY SITE BESIDES KBMG AS NATURE OF CONVECTION WILL
BE POP UP AND SCATTERED. KBMG IS THE EXCEPTION TO THIS AS A LINE OF
STORMS ACROSS SOUTHERN ILLINOIS AT 1630Z IS HEADED TOWARD KBMG...AND
HAVE TIMED THIS LINE IN AND INCLUDED TEMPO THUNDER AND MVFR FOR A
COUPLE HOURS AROUND THE LINES ARRIVAL. CURRENT MOVEMENT AND TIMING
HAS THIS LINE MISSING THE REST OF THE SITES.
SHOULD SEE THIS ROUND OF CONVECTION MOVING OUT OF THE AREA BY AROUND
0-1Z. COULD SEE SOME ELEVATED ACTIVITY DEVELOP OVERNIGHT BUT THINK
LIKELIHOOD IS LOW ENOUGH TO LEAVE OUT. FORECAST SOUNDINGS DO SHOW A
STRONG INVERSION DEVELOPING OVERNIGHT AND HAVE CONCERNS THAT THIS
COULD LEAD TO LOWER VISIBILITIES...BUT WITH SOME CLOUD COVER...SOME
MIXING...AND CHANCES FOR PRECIP JUST DON/T FEEL CONFIDENT ENOUGH TO
GO LOWER THAN MVFR AT THIS TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/SMF
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...CP
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
154 AM EDT THU MAR 15 2012
.AVIATION...
06Z TAFS...ELEVATED THUNDERSTORMS HAVE BEEN ON THE INCREASE OVER
THE PAST FEW HOURS AT THE NOSE OF STRONG LOW LEVEL THEATE
ADVECTION. THIS AXIS OF FORCING HAS ORIENTED ITSELF ROUGHLY ALONG
AND EAST OF A KAZO TO KFWA LINE. WOULD SUSPECT THAT GREATER
CONVECTIVE COVERAGE WILL STAY EAST OF KFWA/KSBN THROUGH THE
REMAINDER OF THE OVERNIGHT HOURS...BUT STILL A CONCERN OF AN
ISOLATED THUNDERSTORM AFFECTING THE TERMINALS OVERNIGHT AS A WEAK
SHORT WAVE ACROSS NORTHERN ILLINOIS TRACKS INTO NORTHERN INDIANA.
PROBABILITY OF ANY TERMINAL RECEIVING TSRA IS QUITE LOW AND WILL
CONTINUE WITH CB MENTION AT THIS TIME AND MONITOR TRENDS. OTHER
CONCERN OVERNIGHT WILL BE INCREASING STRATUS/FOG POTENTIAL. STILL
FEEL THAT MORE OF A STRATUS SETUP WILL BE FAVORED BUT CONFIDENCE
REMAINS LOW ENOUGH TO KEEP CONDITIONS MVFR AT THIS TIME.
STRATUS/FOG SHOULD MIX OUT BY MID MORNING WITH GENERALLY VFR
CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE PERIOD. GUSTY
SOUTHWEST WINDS TO 10 TO 20 KNOTS EXPECTED DURING THE DAY AHEAD OF
THE FRONT. ISOLATED THUNDER POSSIBLE DURING THE AFTERNOON...BUT
LACK OF STRONG FORCING PRECLUDES TAF MENTION.
&&
SHORT TERM.../TONIGHT THROUGH THURSDAY NIGHT/
MAIN FOCUS WILL BE ON CONVECTIVE CHANCES THROUGH THE PERIOD AS WELL
AS CONTINUATION OF UNSEASONABLE WARM TEMPERATURES.
AS EXPECTED...TEMPERATURES HAVE SOARED WELL INTO THE 70S THIS
AFTERNOON WITH INCREASING LL FLOW AND STRONG MIXING. ELEVATED MIXED
LAYER IS KEEPING CLOUDS AT BAY FOR THE TIME BEING ACROSS MUCH OF THE
REGION. AS WE PROGRESS INTO THIS EVENING...THIS WILL CHANGE AS NOSE
OF LL THETA E SURGE AND INCREASING ISENTROPIC LIFT MOVES ACROSS
INDIANA INTO OHIO. LOCAL WRF MOST AGGRESSIVE WITH THIS FEATURE
FORCING CONVECTION TO INITIATE BY LATE AFTERNOON TO OUR WEST AND
SWINGING IT THROUGH THE AREA THROUGH MIDNIGHT. NAM KEEP ACTIVITY
SUPPRESSED FURTHER SOUTH. MIDDLE ROAD MODELS (HRRR/4KM SPC WRF) ALSO
FOCUS BULK OF CONVECTION ACROSS CNTRL/SOUTHERN INDIANA WITH
ISOL/WIDELY SCT CONVECTION INTO PORTIONS OF NORTHERN INDIANA. VIS
SAT SHOWS EXPANDING CU FIELD ACROSS CENTRAL ILLINOIS WHERE SFC
DEWPTS WERE NOW IN THE LOWER 60S. AT 18Z...ISOLATED SHOWERS WERE
NOTED SOUTHWEST OF ST LOUIS...WITH A FEW LIGHTNING STRIKES SHOWING
UP IN THE BOOTHILL OF MISSOURI...WHICH 14-15ZZ HRRR AND 12Z 4KM SPC
WRF PLACED PERFECTLY...WITH NAM SHOWING NO DEVELOPMENT. THE
LIGHTNING STRIKES WERE NOTED ON NOSE OF MID 60 DEWPTS. AM INCLINED
TO LEAN TOWARDS THESE MODELS AND THEIR TRENDS...WHICH BLEND NICELY
WITH INHERITED GRIDS. SPC HAS CONFINED SLGT RISK FURTHER SOUTH INTO
SOUTHERN ILLINOIS AND SW INDIANA. WILL NEED TO MONITOR CONVECTIVE
DEVELOPMENT INTO THIS EVENING WITH RISK OF STRONG STORMS IN PLACE.
WITH THE INCREASE IN LL MSTR...GRIDS NEEDED TO BE PATCHED UP TO
INCREASE OVERNIGHT LOWS CLOSER TO 60...AS WELL AS SUBSEQUENT
INCREASING IN DEWPTS. FOG POTENTIAL STILL LOOMS LATER TONIGHT AS
WEAK BOUNDARY SLIDES SOUTH TOWARDS THE AREA. HOWEVER...WITH
POTENTIAL OF EVENING CONVECTION AND CHANCES IT COULD MESS UP LL
PROFILES...WILL NOT MAKE ANY CHANGES IN REGARDS TO PREV INSERTION OF
FOG.
BOUNDARY WILL STALL OUT ACROSS THE AREA THURSDAY INTO THURSDAY
EVENING PUSHING SOUTHWARD. THIS WILL CAUSE NUMEROUS ISSUES WITH THE
FORECAST WITH POTENTIAL FOR WIDESPREAD CLOUD COVER...POSSIBLY FOG
AND CHANCES FOR SHOWERS AND STORMS. BROADBRUSHED APPROACH BEST
OPTION AT THIS POINT WITH DECREASE IN POPS IN NW AREAS BY THURS NGT
AS DRIER AIR TRIES TO FILTER IN. CAN`T REALLY ADD MUCH DETAIL TO
GRIDS AT THIS POINT WITH SEVERAL SCENARIOS POSSIBLE. UNSEASONABLY
WARM TEMPS WILL STILL BE IN STORE WITH HIGHS INTO THE 70S.
&&
LONG TERM...
FEW CHANGES TO LONG TERM GRIDS WITH CRALLBLEND INIT IN BALLPARK.
UNSEASONABLY WARM PATTERN CONTINUES THROUGH THE PERIOD WITH DEEP
TROUGH DEVELOPING IN THE WEST AND STAUNCH RIDGE FOR LATE MARCH
DEVELOPING OVER THE MIDWEST. MEDIUM RANGE MODELS HAVE DIFFERENCES IN
THE DETAILS AS EXPECTED WITH NUMEROUS SHORT WAVES AND ABUNDANT
MOISTURE. PWATS STILL EXPECTED ABOVE AN INCH THROUGH THE PERIOD WITH
SURFACE DEWPOINTS IN THE 50S AND POOLING INTO 60S AT TIMES. THIS
WILL SET STAGE FOR PERIODS OF SHOWERS AND THUNDERSTORMS DEPENDENT ON
TIMING OF EACH WAVE. SHEAR PROFILES REMAIN WEAK WHILE MUCAPES ABOVE
2000 J/KG AT TIMES SO ISOLATED SEVERE STORMS REMAIN A POSSIBILITY.
TEMPERATURES WILL REMAIN 20 TO 25 DEGREES ABOVE NORMAL THROUGH END
OF PERIOD...POSSIBLY HIGHER NEXT WEEK DEPENDING ON DEGREE OF CLOUD
COVER. HIGHS IN THE 80S REMAIN A POSSIBILITY IF FULL MIXING CAN BE
ACHIEVED NEXT WEEK. WITH SUCH A DEEP SYSTEM TO THE WEST FEEL MODELS
ARE TOO FAST WITH APPROACH OF TROUGH FOR MIDDLE OF NEXT WEEK AND
THUS WED WILL CONTINUE TO BE WARM. RAISED ALLBLEND INIT TEMPS
SEVERAL DEGREES IN LINE WITH DAY 5 AND 6 TEMPS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...FISHER
LONG TERM...LASHLEY
AVIATION...MARSILI
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
944 PM EDT FRI MAR 16 2012
.Update...
Issued at 945 PM EDT Fri Mar 16 2012
Have updated grids to mainly reflect latest position of scattered to
numerous showers across south central Kentucky associated with MCV.
Saw a lightning strike or two with the strongest updrafts earlier
this evening so will leave mention of isolated thunder in the
forecast. On an otherwise quiet evening, a few of the cells near the
Bowling Green region put on quite a show, displaying supercell
characteristics at times. Storms developed on a north south oriented
boundary across west central Kentucky and Tennessee, then maintained
sustained updrafts with deviant (right-moving) motion near Bowling
Green. Weak rotation was maintained on radar, with a spotter
observing weak rotation at times. How these cells were able to
maintain updrafts without any organized deep shear remains a mystery.
Showers associated with the MCV will slide across south central
Kentucky for the next few hours with only an isolated chance
elsewhere across the CWA. Still remains some question as to how the
overnight period will go with respect to weak isentropic lift
component across western CWA between 06-12Z so will just mention
isolated chances, however do expect coverage of precipitation to
gradually increase from southwest to northeast after 12Z. Best
chance for showers and thunderstorms still looks to be tomorrow
afternoon and evening as a shortwave moves through the region from
the southwest.
Forecast looks on track, with skies generally becoming partly cloudy
through the overnight. Will have to watch for fog potential as
recent rainfall combines with improving radiational cooling
conditions as skies clear and winds remain light and variable.
Tweaked lows down just a bit with most spots in the upper 50s and a
few locations hanging on around 60. Updated products already out.
Update issued at 654 PM EDT Fri Mar 16 2012
Showers have developed over the west central portion of the CWA with
MCV that is slowly rotating through western Kentucky. A look at
forecast soundings shows that updrafts should struggle above 15-20 K
feet as thermal profile warms significantly above this level. Do not
expect much more than a few moderate showers mainly across central
Kentucky, although cannot rule out an isolated thunderstorm or two.
Have tweaked pops just a bit through the overnight hours with the
potential for a scattered line of mainly showers to develop over the
Bowling Green region and lift northeastward from 06 to 12z. Models
disagree on the timing with NAM/GFS more toward dawn, however higher
res HRRR which has current situation handled well begins precip just
after 06 z. The main culprit appears to be some weak isentropic
lift with a weak low level jet. Will monitor trends and update
timing as needed. Otherwise, the rest of the forecast looks on track
at this point.
.Short Term (Tonight through Saturday Night)...
Updated at 255 PM EDT Mar 16 2012
Meso low continues to spin just to our west, now with a surface
reflection in latest MSAS analysis. Fortunately for us, persistent
cloud cover for most of the day so far has inhibited convection over
our CWA. Western Kentucky has been clearer though, and that area now
is seeing some convections, with cells initiating over eastern PAH`s
forecast area. Temperatures are climbing over the western forecast
area, so should start seeing some action there a little later this
afternoon, especially as that low drifts eastward.
Beyond this afternoon and through Saturday night, the atmosphere
will remain plenty moist for additional shower and storm
development. Confidence in timing/location still is not high though.
Precipitable waters will be above an inch. Will have multiple
perturbations in the flow aloft coming across the region, which will
enhance development, especially should these come during any peak
heating times. Given the moist atmosphere, diurnal temperature
swings should be short, and expect readings well above normal for
mid March. Going for lows each night around 60 and highs generally
in the upper 70s.
.Long Term (Sunday - Friday)...
Updated at 255 PM EDT Mar 16 2012
For Sunday, another shortwave in the upper level flow will cross the
Ohio Valley. The models are still having a bit of a hard time with
the timing and the placement of this feature. This will impact how
widespread storms become on Sunday. For now we will continue to
carry a 30-40% chance for thunderstorms. Soundings do become
relatively unstable during the day so a few of these storms may
become strong. These will be the pulse type like we have seen the
last couple of days, with hail being the main threat.
For the beginning of the work week, a highly amplified ridge will
build over the area. This will lead to partly cloudy skies and dry
weather Monday through Tuesday. At the surface, winds will remain
out of the south. Unseasonably warm temperatures will continue with
a shot at breaking some record highs Sunday through Monday.
Current records and forecast temps for Sun/Mon/Tues:
ASOS Sun(3/18) Mon(3/19) Tues(3/20)
Record/Forecast:
SDF 82(1982)/81 83(1907)/83 85(1894)/82
LEX 79(1982)/79 79(1945)/81 81(1894)/81
BWG 87(1908)/82 86(1907)/83 85(1921)/82
FFT 80(1908)/80 81(1948)/82 82(1921)/81
We will see a big change in the weather for the second half of the
week. A large upper level low will approach and cross the region
Wednesday through Friday. Clouds will be on the increase on
Wednesday, keeping temperatures a few degrees cooler than the
previous days. Rain from this system looks to move in Wednesday
night with showers and thunderstorms continuing into Friday as the
low slowly crosses the region. Temperatures will be much cooler
Thursday and Friday. Despite this, temps will remain above normal
for this time of year with highs in the mid 60s to lower 70s and
lows in the upper 40s to lower 50s.
&&
.Aviation (00Z TAF Issuance)...
Updated at 717 PM EDT Mar 16 2012
A few strong showers are near the BWG terminal this evening, however
should gradually slide east over the next hour or two. Otherwise,
only expect an isolated chance of a shower or storm through the rest
of the evening at all TAF sites. Conditions are expected to stay
VFR. Could see some additional shower development in the BWG region
after 1 AM CDT, however more likely toward dawn. Will watch as
conditions could become favorable for some MVFR BR at TAF sites
toward dawn as well. Much will depend on upper level sky cover as
winds will be nearly calm. Chances for scattered showers and
thunderstorms ramp up on Saturday afternoon and evening with
southwesterly winds between 5 and 10 mph.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........BJS
Short Term.......RJS
Long Term........EER
Aviation.........BJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
716 PM EDT FRI MAR 16 2012
.Update...
Issued at 654 PM EDT Fri Mar 16 2012
Showers have developed over the west central portion of the CWA with
MCV that is slowly rotating through western Kentucky. A look at
forecast soundings shows that updrafts should struggle above 15-20 K
feet as thermal profile warms significantly above this level. Do not
expect much more than a few moderate showers mainly across central
Kentucky, although cannot rule out an isolated thunderstorm or two.
Have tweaked pops just a bit through the overnight hours with the
potential for a scattered line of mainly showers to develop over the
Bowling Green region and lift northeastward from 06 to 12z. Models
disagree on the timing with NAM/GFS more toward dawn, however higher
res HRRR which has current situation handled well begins precip just
after 06 z. The main culprit appears to be some weak isentropic
lift with a weak low level jet. Will monitor trends and update
timing as needed. Otherwise, the rest of the forecast looks on track
at this point.
.Short Term (Tonight through Saturday Night)...
Updated at 255 PM EDT Mar 16 2012
Meso low continues to spin just to our west, now with a surface
reflection in latest MSAS analysis. Fortunately for us, persistent
cloud cover for most of the day so far has inhibited convection over
our CWA. Western Kentucky has been clearer though, and that area now
is seeing some convections, with cells initiating over eastern PAH`s
forecast area. Temperatures are climbing over the western forecast
area, so should start seeing some action there a little later this
afternoon, especially as that low drifts eastward.
Beyond this afternoon and through Saturday night, the atmosphere
will remain plenty moist for additional shower and storm
development. Confidence in timing/location still is not high though.
Precipitable waters will be above an inch. Will have multiple
perturbations in the flow aloft coming across the region, which will
enhance development, especially should these come during any peak
heating times. Given the moist atmosphere, diurnal temperature
swings should be short, and expect readings well above normal for
mid March. Going for lows each night around 60 and highs generally
in the upper 70s.
.Long Term (Sunday - Friday)...
Updated at 255 PM EDT Mar 16 2012
For Sunday, another shortwave in the upper level flow will cross the
Ohio Valley. The models are still having a bit of a hard time with
the timing and the placement of this feature. This will impact how
widespread storms become on Sunday. For now we will continue to
carry a 30-40% chance for thunderstorms. Soundings do become
relatively unstable during the day so a few of these storms may
become strong. These will be the pulse type like we have seen the
last couple of days, with hail being the main threat.
For the beginning of the work week, a highly amplified ridge will
build over the area. This will lead to partly cloudy skies and dry
weather Monday through Tuesday. At the surface, winds will remain
out of the south. Unseasonably warm temperatures will continue with
a shot at breaking some record highs Sunday through Monday.
Current records and forecast temps for Sun/Mon/Tues:
ASOS Sun(3/18) Mon(3/19) Tues(3/20)
Record/Forecast:
SDF 82(1982)/81 83(1907)/83 85(1894)/82
LEX 79(1982)/79 79(1945)/81 81(1894)/81
BWG 87(1908)/82 86(1907)/83 85(1921)/82
FFT 80(1908)/80 81(1948)/82 82(1921)/81
We will see a big change in the weather for the second half of the
week. A large upper level low will approach and cross the region
Wednesday through Friday. Clouds will be on the increase on
Wednesday, keeping temperatures a few degrees cooler than the
previous days. Rain from this system looks to move in Wednesday
night with showers and thunderstorms continuing into Friday as the
low slowly crosses the region. Temperatures will be much cooler
Thursday and Friday. Despite this, temps will remain above normal
for this time of year with highs in the mid 60s to lower 70s and
lows in the upper 40s to lower 50s.
&&
.Aviation (00Z TAF Issuance)...
Updated at 717 PM EDT Mar 16 2012
A few strong showers are near the BWG terminal this evening, however
should gradually slide east over the next hour or two. Otherwise,
only expect an isolated chance of a shower or storm through the rest
of the evening at all TAF sites. Conditions are expected to stay
VFR. Could see some additional shower development in the BWG region
after 1 AM CDT, however more likely toward dawn. Will watch as
conditions could become favorable for some MVFR BR at TAF sites
toward dawn as well. Much will depend on upper level sky cover as
winds will be nearly calm. Chances for scattered showers and
thunderstorms ramp up on Saturday afternoon and evening with
southwesterly winds between 5 and 10 mph.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........BJS
Short Term.......RJS
Long Term........EER
Aviation.........BJS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
211 AM EDT THU MAR 15 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK SLOWLY EAST OF THE REGION OVERNIGHT. HIGH
PRESSURE WILL BUILD BRIEFLY INTO THE AREA LATER THURSDAY. A WEAK
TROUGH OF LOW PRESSURE WILL APPROACH FROM THE WEST ON FRIDAY AND
CROSS THE STATE LATE FRIDAY AND FRIDAY NIGHT. HIGH PRESSURE WILL
REBUILD INTO THE AREA OVER THE WEEKEND WITH AN UNSEASONABLY WARM
WEATHER PATTERN SHAPING UP FOR NEXT WEEK.&&
.NEAR TERM /THROUGH TODAY/...
UPDATE: SNOW CONTS ACROSS NE AND E CENTRAL AREAS BUT HAS BEGUN TO LIGHTEN
UP AND THIS TREND WILL CONT OVR THE NEXT SEVERAL HRS BEFORE ENDING
ERLY THU AM. HAVE ALLOWED THE REMAINING ADV AND THE WNTR STORM
WRNG TO EXPIRE.
UPDATE: GOOD DEFORMATION AXIS CONTS ATTM ACROSS NE AND E CENTRAL
AREAS. PER LATEST TRENDS...RAISED SNOW AMOUNTS ACROSS ERN SECTIONS
A BIT MORE AND ADJUSTED POPS. ALLOWED WRN ADVS TO EXPIRE AND XTND
ERN ADVS TIL 2 AM. CURRENT WRNG FOR ZN2 CONTS TIL 2 AM AND COULD
SEE SOME LOCALIZED ACCUMS UP TO A FOOT ACROSS ERN SECTIONS WHEN
ALL IS SAID AND DONE.
UPDATE 2: BASED ON LATEST SPOTTER SNOW REPORTS RECEIVED FROM THE
CARIBOU...FORT FAIRFIELD...PRESQUE ISLE AREA WHICH WERE UP TO 7 TO
8 INCHES AND LATEST MESO-MODEL GUIDANCE...INCLUDING THE 18Z NAM
AND 21Z HRRR MODELS THAT NOW KEEP THE BAND ORIGINATING FROM SRN
NB AIMED TOWARD NE ME OVR THE SAME RELATIVE AREA FOR THE NEXT FEW
HRS; IT APPEARS IMMINENT THAT SOME LOCATIONS COULD EXPERIENCE A
STORM TOTAL UP TO OR JUST OVER 10 INCHES...WITH THE HIGHEST
AMOUNTS CLUSTERED NEAR THE NB BORDER BOUNDED BY LIMESTONE...
CARIBOU...PRESQUE ISLE AND MARS HILL. INDEED...THE AMOUNT OF AREA
TO BE AFFECTED BY HEAVY SN ACCUMULATIONS WITHIN NE AROOSTOOK
COUNTY IS LESS THAN 50 PERCENT OF ZONE 2...BUT IS AFFECTING THE
MOST URBAN AREAS THE MOST. RADAR INDICATES ONE LAST PULSE (PERHAPS
THE LAST) OF MDT TO HVY SN WITH THIS BAND TAKING AIM TOWARD THE
WRNG AREA...SO SNFL RATES UP TO AN INCH AN HR AT TIMES OVR SOME
AREAS CAN BE XPCTD UNTIL MDNGT OR SO BEFORE SN RATES WIND DOWN.
WITH DEEP ELEVATED WARM ADVCN WEAKENING IN THE TROWAL ZONE XTNDG
TOWARD E ME DURG THE LATE NGT/ERLY MORN HRS...ANY REMAINING
ORGANIZED SNFL SHOULD QUICKLY WIND DOWN OVR THE FA AS THE UPPER
LOW BEGINS TO MOVE INTO SRN NB.
UPDATE 1: SENT A QUICK UPDATE TO INCREASE TOTAL SNFL AMOUNTS
TO 4 TO 8 IN ACROSS PORTIONS OF NERN AND FAR NRN AROOSTOOK COUNTY
BASED ON A FEW OBS OF 5 IN ATTM. SOME UNCERTAINTY EXISTS REGARDING
HOW BANDING WILL EVOLVE OVR THE NEXT FEW HRS...WITH NEAR TERM
MODELS SUCH AS THE HRRR SHOWING THE ENHANCED BANDING CURRENTLY
JUST W OF THE ME-NB BORDER POSSIBLY GRAZING FAR NE AROOSTOOK
COUNTY. WILL MONITOR CLOSELY DURG THIS TM.
ORGNL DISC: UPPER LOW TRACKING TOWARDS THE WESTERN BORDER OF
MAINE AS EXPECTED. SOME INSTABILITY ABOVE H850 AND A SHARP UPPER
TROUGH ROTATING AROUND THE CLOSED UPPER LOW IS PRODUCING LOCALLY
HEAVIER SNOW SHOWERS IN FAR NORTHEASTERN ZONES. WILL GO FOR UP TO
5 INCHES IN NE CORNER OF STATE...BUT EXPECT WIDE VARIATIONS FOR
NORTHERN ZONES DUE TO HIT OR MISS NATURE OF THE HEAVIER SNOW
SHOWERS. MOISTURE CONTINUES TO WRAP BACK NORTHWESTWARDS FROM THE
MARITIMES AND WILL HELP PROLONG SNOW IN NORTHERN ZONES WELL INTO
THE NIGHT. DOWN EAST AREAS WILL GET A BRIEF SHOT OF SNOW THIS
EVENING THAT MAY LAY DOWN AN INCH OR SO. THIS WILL BE IN
CONJUNCTION WITH THE UPPER LOW PASSAGE. THE THREAT FOR FZDZ IS
STILL THERE WITH THE RISK FROM NEAR MILO TOWARDS NORTHERN
WASHINGTON COUNTY THIS AFTERNOON AND QUICKLY SHIFTING TO SOUTHERN
WASHINGTON COUNTY THIS EVENING BEFORE THE WARM AIR ALOFT IS GONE.
TEMPERATURES TONIGHT WILL DIP SLIGHTLY IN THE LOWER 20S NORTH AND
UPPER 20S DOWN EAST.
WITH SNOW ENDING IN THE FAR EASTERN ZONES EARLY THURSDAY
MORNING...HIGH PRESSURE WILL BUILD BUT CLOUD COVER ASSOCIATED WITH
A SUBSIDENCE INVERSION WILL BE SLOW TO ERODE FROM THE WEST. EXPECT
SOME CLEARING TOWARDS BANGOR BY AFTERNOON...BUT NOT UNTIL LATE DAY
TOWARDS THE EASTERN BORDER OF THE STATE. HIGHS WILL REACH THE LOW
TO MID 30S TOWARDS THE SJV AND INCREASE TOWARDS DOWN EAST WHERE
LOW 40S ARE LIKELY.&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL CREST THE REGION THURSDAY NIGHT AND THEN MOVE
EAST OF THE AREA EARLY FRIDAY. MODELS IN GOOD AGREEMENT WITH UPPER
TROUGH APPROACHING FROM THE WEST FRIDAY AND CROSSING THE STATE BY
FRIDAY EVENING. EXPECT ASSOCIATED LOW PRESSURE AND COLD FRONT TO
SPREAD MAINLY RAIN FROM WEST TO EAST ACROSS THE STATE FRIDAY
AFTERNOON. RAIN MAY MIX WITH SNOW ACROSS EXTREME NORTHERN
SECTIONS. THEN AS UPPER TROUGH MOVES EAST OF THE STATE, CONDITIONS
WILL IMPROVE FROM WEST TO EAST FRIDAY NIGHT. QPF AMOUNTS AT THIS
TIME APPEARS TO BE ON THE LIGHT SIDE WITH AMOUNTS GENERALLY BELOW A
QUARTER OF AN INCH. HIGH PRESSURE THEN BUILD ACROSS NEW ENGLAND ON
SATURDAY WITH CLEAR SKIES AND MODERATING TEMPERATURES INTO THE 40S
AND 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
RIDGING BUILDING ALONG THE EAST COAST WILL SET THE STAGE FOR SOME
VERY MILD WEATHER GOING INTO EARLY NEXT WEEK. HIGH PRESSURE ALONG
THE EAST COAST WILL BRING A MOSTLY CLEAR NIGHT SATURDAY NIGHT
FOLLOWED BY A PARTLY SUNNY AND MILD DAY ON SUNDAY. THE LATEST GFS
SHOWS A WEAK COLD FRONT MOVING IN LATE SUNDAY WHICH MAY BRING
INCREASING CLOUDS LATE IN THE DAY. THE ECMWF BRINGS A WEAK FRONT
THROUGH LATER MONDAY. HIGH PRESSURE THEN CONSOLIDATES AGAIN ALONG THE
EAST COAST TUESDAY AS A VERY STRONG RIDGE OF HIGH PRESSURE BUILDS
INTO THE EAST. THIS WILL BRING A PARTLY SUNNY AND VERY MILD DAY ON
TUESDAY. THE STRONGEST INFLUENCE OF THE RIDGING WILL LIKELY COME
WEDNESDAY WHEN WARM WEST TO SOUTHWEST WINDS BOOST TEMPS INTO THE 60S
AND PERHAPS EVEN 70S ACROSS THE REGION. THE VERY WARM TEMPS DURING
THE MID WEEK NEXT WEEK WILL LIKELY RESULT IN LOTS OF SNOW MELT. THE
RELEASE OF SNOW MELT MAY RESULT IN RISES ON RIVERS AND POTENTIAL ICE
JAMS DURING THE MID AND LATE WEEK NEXT WEEK.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
NEAR TERM: IFR TONIGHT FOR ALL TERMINALS...BCMG MVFR THURSDAY
MORNING AND VFR BY LATE AFTERNOON.
SHORT TERM: VFR THURSDAY NIGHT INTO EARLY FRIDAY THEN CONDITIONS
WILL LOWER TO MVFR/IFR IN RAIN FRIDAY AFTERNOON THROUGH FRIDAY
EVENING AND THEN IMPROVE TO VFR LATER FRIDAY NIGHT. EXPECT VFR
CONDITIONS SATURDAY THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM: SCA WILL CONTINUE INTO EARLY THURSDAY MORNING...BARELY
MEETING CRITERIA WITH WIND GUSTS AROUND 25 KTS AND 5 FT SEAS.
SHORT TERM: WINDS AND SEAS BELOW SCA CRITERIA THURSDAY NIGHT
THROUGH SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
ANZ050>052.
&&
$$
NEAR TERM...KHW/VJN
SHORT TERM...FOSTER
LONG TERM...BLOOMER
AVIATION...KHW
MARINE...KHW/FOSTER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1241 AM EDT THU MAR 15 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK SLOWLY EAST OF THE REGION OVERNIGHT. HIGH
PRESSURE WILL BUILD BRIEFLY INTO THE AREA LATER THURSDAY. A WEAK
TROUGH OF LOW PRESSURE WILL APPROACH FROM THE WEST ON FRIDAY AND
CROSS THE STATE LATE FRIDAY AND FRIDAY NIGHT. HIGH PRESSURE WILL
REBUILD INTO THE AREA OVER THE WEEKEND WITH AN UNSEASONABLY WARM
WEATHER PATTERN SHAPING UP FOR NEXT WEEK.&&
.NEAR TERM /THROUGH TODAY/...
UPDATE: GOOD DEFORMATION AXIS CONTS ATTM ACROSS NE AND E CENTRAL
AREAS. PER LATEST TRENDS...RAISED SNOW AMOUNTS ACROSS ERN SECTIONS
A BIT MORE AND ADJUSTED POPS. ALLOWED WRN ADVS TO EXPIRE AND XTND
ERN ADVS TIL 2 AM. CURRENT WRNG FOR ZN2 CONTS TIL 2 AM AND COULD
SEE SOME LOCALIZED ACCUMS UP TO A FOOT ACROSS ERN SECTIONS WHEN
ALL IS SAID AND DONE.
UPDATE 2: BASED ON LATEST SPOTTER SNOW REPORTS RECEIVED FROM THE
CARIBOU...FORT FAIRFIELD...PRESQUE ISLE AREA WHICH WERE UP TO 7 TO
8 INCHES AND LATEST MESO-MODEL GUIDANCE...INCLUDING THE 18Z NAM
AND 21Z HRRR MODELS THAT NOW KEEP THE BAND ORIGINATING FROM SRN
NB AIMED TOWARD NE ME OVR THE SAME RELATIVE AREA FOR THE NEXT FEW
HRS; IT APPEARS IMMINENT THAT SOME LOCATIONS COULD EXPERIENCE A
STORM TOTAL UP TO OR JUST OVER 10 INCHES...WITH THE HIGHEST
AMOUNTS CLUSTERED NEAR THE NB BORDER BOUNDED BY LIMESTONE...
CARIBOU...PRESQUE ISLE AND MARS HILL. INDEED...THE AMOUNT OF AREA
TO BE AFFECTED BY HEAVY SN ACCUMULATIONS WITHIN NE AROOSTOOK
COUNTY IS LESS THAN 50 PERCENT OF ZONE 2...BUT IS AFFECTING THE
MOST URBAN AREAS THE MOST. RADAR INDICATES ONE LAST PULSE (PERHAPS
THE LAST) OF MDT TO HVY SN WITH THIS BAND TAKING AIM TOWARD THE
WRNG AREA...SO SNFL RATES UP TO AN INCH AN HR AT TIMES OVR SOME
AREAS CAN BE XPCTD UNTIL MDNGT OR SO BEFORE SN RATES WIND DOWN.
WITH DEEP ELEVATED WARM ADVCN WEAKENING IN THE TROWAL ZONE XTNDG
TOWARD E ME DURG THE LATE NGT/ERLY MORN HRS...ANY REMAINING
ORGANIZED SNFL SHOULD QUICKLY WIND DOWN OVR THE FA AS THE UPPER
LOW BEGINS TO MOVE INTO SRN NB.
UPDATE 1: SENT A QUICK UPDATE TO INCREASE TOTAL SNFL AMOUNTS
TO 4 TO 8 IN ACROSS PORTIONS OF NERN AND FAR NRN AROOSTOOK COUNTY
BASED ON A FEW OBS OF 5 IN ATTM. SOME UNCERTAINTY EXISTS REGARDING
HOW BANDING WILL EVOLVE OVR THE NEXT FEW HRS...WITH NEAR TERM
MODELS SUCH AS THE HRRR SHOWING THE ENHANCED BANDING CURRENTLY
JUST W OF THE ME-NB BORDER POSSIBLY GRAZING FAR NE AROOSTOOK
COUNTY. WILL MONITOR CLOSELY DURG THIS TM.
ORGNL DISC: UPPER LOW TRACKING TOWARDS THE WESTERN BORDER OF
MAINE AS EXPECTED. SOME INSTABILITY ABOVE H850 AND A SHARP UPPER
TROUGH ROTATING AROUND THE CLOSED UPPER LOW IS PRODUCING LOCALLY
HEAVIER SNOW SHOWERS IN FAR NORTHEASTERN ZONES. WILL GO FOR UP TO
5 INCHES IN NE CORNER OF STATE...BUT EXPECT WIDE VARIATIONS FOR
NORTHERN ZONES DUE TO HIT OR MISS NATURE OF THE HEAVIER SNOW
SHOWERS. MOISTURE CONTINUES TO WRAP BACK NORTHWESTWARDS FROM THE
MARITIMES AND WILL HELP PROLONG SNOW IN NORTHERN ZONES WELL INTO
THE NIGHT. DOWN EAST AREAS WILL GET A BRIEF SHOT OF SNOW THIS
EVENING THAT MAY LAY DOWN AN INCH OR SO. THIS WILL BE IN
CONJUNCTION WITH THE UPPER LOW PASSAGE. THE THREAT FOR FZDZ IS
STILL THERE WITH THE RISK FROM NEAR MILO TOWARDS NORTHERN
WASHINGTON COUNTY THIS AFTERNOON AND QUICKLY SHIFTING TO SOUTHERN
WASHINGTON COUNTY THIS EVENING BEFORE THE WARM AIR ALOFT IS GONE.
TEMPERATURES TONIGHT WILL DIP SLIGHTLY IN THE LOWER 20S NORTH AND
UPPER 20S DOWN EAST.
WITH SNOW ENDING IN THE FAR EASTERN ZONES EARLY THURSDAY
MORNING...HIGH PRESSURE WILL BUILD BUT CLOUD COVER ASSOCIATED WITH
A SUBSIDENCE INVERSION WILL BE SLOW TO ERODE FROM THE WEST. EXPECT
SOME CLEARING TOWARDS BANGOR BY AFTERNOON...BUT NOT UNTIL LATE DAY
TOWARDS THE EASTERN BORDER OF THE STATE. HIGHS WILL REACH THE LOW
TO MID 30S TOWARDS THE SJV AND INCREASE TOWARDS DOWN EAST WHERE
LOW 40S ARE LIKELY.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL CREST THE REGION THURSDAY NIGHT AND THEN MOVE
EAST OF THE AREA EARLY FRIDAY. MODELS IN GOOD AGREEMENT WITH UPPER
TROUGH APPROACHING FROM THE WEST FRIDAY AND CROSSING THE STATE BY
FRIDAY EVENING. EXPECT ASSOCIATED LOW PRESSURE AND COLD FRONT TO
SPREAD MAINLY RAIN FROM WEST TO EAST ACROSS THE STATE FRIDAY
AFTERNOON. RAIN MAY MIX WITH SNOW ACROSS EXTREME NORTHERN
SECTIONS. THEN AS UPPER TROUGH MOVES EAST OF THE STATE, CONDITIONS
WILL IMPROVE FROM WEST TO EAST FRIDAY NIGHT. QPF AMOUNTS AT THIS
TIME APPEARS TO BE ON THE LIGHT SIDE WITH AMOUNTS GENERALLY BELOW A
QUARTER OF AN INCH. HIGH PRESSURE THEN BUILD ACROSS NEW ENGLAND ON
SATURDAY WITH CLEAR SKIES AND MODERATING TEMPERATURES INTO THE 40S
AND 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
RIDGING BUILDING ALONG THE EAST COAST WILL SET THE STAGE FOR SOME
VERY MILD WEATHER GOING INTO EARLY NEXT WEEK. HIGH PRESSURE ALONG
THE EAST COAST WILL BRING A MOSTLY CLEAR NIGHT SATURDAY NIGHT
FOLLOWED BY A PARTLY SUNNY AND MILD DAY ON SUNDAY. THE LATEST GFS
SHOWS A WEAK COLD FRONT MOVING IN LATE SUNDAY WHICH MAY BRING
INCREASING CLOUDS LATE IN THE DAY. THE ECMWF BRINGS A WEAK FRONT
THROUGH LATER MONDAY. HIGH PRESSURE THEN CONSOLIDATES AGAIN ALONG THE
EAST COAST TUESDAY AS A VERY STRONG RIDGE OF HIGH PRESSURE BUILDS
INTO THE EAST. THIS WILL BRING A PARTLY SUNNY AND VERY MILD DAY ON
TUESDAY. THE STRONGEST INFLUENCE OF THE RIDGING WILL LIKELY COME
WEDNESDAY WHEN WARM WEST TO SOUTHWEST WINDS BOOST TEMPS INTO THE 60S
AND PERHAPS EVEN 70S ACROSS THE REGION. THE VERY WARM TEMPS DURING
THE MID WEEK NEXT WEEK WILL LIKELY RESULT IN LOTS OF SNOW MELT. THE
RELEASE OF SNOW MELT MAY RESULT IN RISES ON RIVERS AND POTENTIAL ICE
JAMS DURING THE MID AND LATE WEEK NEXT WEEK.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
NEAR TERM: IFR TONIGHT FOR ALL TERMINALS...BCMG MVFR THURSDAY
MORNING AND VFR BY LATE AFTERNOON.
SHORT TERM: VFR THURSDAY NIGHT INTO EARLY FRIDAY THEN CONDITIONS
WILL LOWER TO MVFR/IFR IN RAIN FRIDAY AFTERNOON THROUGH FRIDAY
EVENING AND THEN IMPROVE TO VFR LATER FRIDAY NIGHT. EXPECT VFR
CONDITIONS SATURDAY THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM: SCA WILL CONTINUE INTO EARLY THURSDAY MORNING...BARELY
MEETING CRITERIA WITH WIND GUSTS AROUND 25 KTS AND 5 FT SEAS.
SHORT TERM: WINDS AND SEAS BELOW SCA CRITERIA THURSDAY NIGHT
THROUGH SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 2 AM EDT EARLY THIS MORNING FOR
MEZ002.
WINTER WEATHER ADVISORY UNTIL 2 AM EDT EARLY THIS MORNING FOR
MEZ005-006-017-032.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
ANZ050>052.
&&
$$
NEAR TERM...KHW/VJN
SHORT TERM...FOSTER
LONG TERM...BLOOMER
AVIATION...KHW
MARINE...KHW/VJN/FOSTER
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
307 PM EDT THU MAR 15 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM, MOVING SLOWLY EAST THROUGH THE GREAT LAKES,
WILL PROVIDE SHOWERS AND SCATTERED THUNDERSTORMS INTO FRIDAY
NIGHT. HIGH PRESSURE WILL FOLLOW WITH DRY CONDITIONS SATURDAY AS
TEMPERATURES WILL REMAIN UNSEASONABLY WARM INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
MODEL GUIDANCE CONTINUES TO DIVERGE ON THE EXTENT OF SHOWERS AND
THUNDERSTORMS ACROSS THE UPPER OHIO VALLEY TONIGHT INTO FRIDAY.
RECENT RADAR DATA AND HRRR MODEL OUTPUT CONTINUES TO SHOW NO MORE
THAN ISOLATED SHOWERS ACROSS THE AREA INTO EARLY EVENING. RECENT
SREF MODEL OUTPUT, SOMEWHAT SUPPORTED BY RECENT HRRR AND WRF-ARW
MODEL OUTPUT, SUGGEST A BAND OF NUMEROUS SHOWERS AND SCATTERED
THUNDERSTORMS MOVING EASTWARD THROUGH THE UPPER OHIO VALLEY LATE
THIS EVENING AND OVERNIGHT.
DESPITE SPC CONTINUING A SLIGHT RISK ACROSS OHIO WEST OF THE I-77
CORRIDOR, HAVE LOW CONFIDENCE IN SEVERE DEVELOPMENT, AS RECENT
SREF MODEL OUTPUT SHOWS WEAK INSTABILITY AND VERTICAL WIND SHEAR
TONIGHT.
FOR CONTINUITY, CONTINUED A CHANCE OF SHOWERS AND THUNDERSTORMS
FRIDAY AS MOST SREF MEMBERS SHOW THE BAND OF SHOWERS HAVING EXITED
BY MORNING, AND UPPER LEVEL RIDGING ACROSS THE EASTERN U.S.
INCREASING.
FORECASTED TEMPERATURES BASED ON BLEND OF RECENT GFS AND NAM MOS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
A SERIES OF SHORTWAVES MOVING ACROSS AN UPPER LEVEL RIDGE OVER THE
EAST COAST WILL PROVIDE UNSETTLED WEATHER THROUGH THE WEEKEND.
HAVE GONE WITH SLIGHT CHANCE OF THUNDERSTORMS ON SATURDAY AND
CHANCE ON SUNDAY. INCONSISTENCY STILL EXISTS BETWEEN THE NAM AND
GFS FOR THUNDERSTORMS.
TREND OF WELL ABOVE NORMAL TEMPERATURES CONTINUES INTO NEXT WEEK.
RECORD HIGH TEMPERATURES COULD BE SET IN AREAS AROUND PITTSBURGH
AND SOUTH WITH TEMPERATURES REACHING THE UPPER 70S. CURRENT RECORD
HIGHS FOR SPECIFIC SITES ARE LISTED IN THE CLIMATE SECTION.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WEAK TROF MOVING ACROSS SOUTHERN LAKES COULD TRIGGER SCATTERED
SHOWERS OR THUNDERSTORMS FROM LATE SUNDAY THROUGH MONDAY MORNING.
GFS MAINTAINS CONSIDERABLY STRONGER SHORT WAVE THAN OTHER MODELS. AN
UPPER RIDGE WILL AMPLIFY ACROSS THE EASTERN STATES EARLY NEXT WEEK
AND REMAIN IN PLACE THROUGH WEDNESDAY. SURFACE HIGH PRESSURE IS
PROGGED TO HOLD ALONG THE MID ATLANTIC COAST AND MAINTAIN SOUTHWEST
FLOW ACROSS THE UPPER OHIO VALLEY REGION.
MUCH ABOVE NORMAL TEMPERATURES THROUGHOUT THE PERIOD WITH
TEMPERATURES AVERAGING NEARLY 20 DEGREES PER DAY ABOVE NORMAL.
NEXT FRONT APPROACHES UPPER OHIO RIVER VALLEY ON FRIDAY.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
GENERAL VFR CONDITIONS WILL PREVAIL THROUGH 16/06Z. WEAK FRONT
LOCATED ACROSS SOUTHERN GREAT LAKES WILL MOVE ACROSS REGION LATE
TONIGHT AND POSSIBLY TRIGGER SHOWERS AND SOME THUNDERSTORMS WITH
MVFR VSBY THROUGH 14Z.
AREA OF SHOWERS AND THUNDERSTORMS CURRENTLY OVER SOUTHERN OHIO AND
MOVING INTO WEST VIRGINA WILL STAY SOUTH OF CWA. APPEARS THIS
FEATURE IS TRAPPING MOST OF THE AVAILABLE MOISTURE AND WILL KEEP
LATE AFTERNOON AND EVENING CONVECTION AT A MINIMUM ACROSS CWA.
EXPECT VFR CONDITIONS FROM FRIDAY AFTERNOON THROUGH SUNDAY WITH WEAK
HIGH PRESSURE OVER REGION.
OUTLOOK...SUNDAY NIGHT THROUGH TUESDAY...
WEAK UPPER TROF MOVING THROUGH SOUTHERN GREAT LAKES LATE SUNDAY AND
SUNDAY NIGHT MAY TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS WITH
BEST CHANCE OF RESTRICTIONS ACROSS NORTHERN PA.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES FOR MARCH 17.
PITTSBURGH PA 73 SET IN 1945.
ZANESVILLE OH 74 SET IN 1989.
MORGANTOWN WV 75 SET IN 1989.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
257 PM EDT THU MAR 15 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM, MOVING SLOWLY EAST THROUGH THE GREAT LAKES,
WILL PROVIDE SHOWERS AND SCATTERED THUNDERSTORMS INTO FRIDAY
NIGHT. HIGH PRESSURE WILL FOLLOW WITH DRY CONDITIONS SATURDAY AS
TEMPERATURES WILL REMAIN UNSEASONABLY WARM INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
MODEL GUIDANCE CONTINUES TO DIVERGE ON THE EXTENT OF SHOWERS AND
THUNDERSTORMS ACROSS THE UPPER OHIO VALLEY TONIGHT INTO FRIDAY.
RECENT RADAR DATA AND HRRR MODEL OUTPUT CONTINUES TO SHOW NO MORE
THAN ISOLATED SHOWERS ACROSS THE AREA INTO EARLY EVENING. RECENT
SREF MODEL OUTPUT, SOMEWHAT SUPPORTED BY RECENT HRRR AND WRF-ARW
MODEL OUTPUT, SUGGEST A BAND OF NUMEROUS SHOWERS AND SCATTERED
THUNDERSTORMS MOVING EASTWARD THROUGH THE UPPER OHIO VALLEY LATE
THIS EVENING AND OVERNIGHT.
DESPITE SPC CONTINUING A SLIGHT RISK ACROSS OHIO WEST OF THE I-77
CORRIDOR, HAVE LOW CONFIDENCE IN SEVERE DEVELOPMENT, AS RECENT
SREF MODEL OUTPUT SHOWS WEAK INSTABILITY AND VERTICAL WIND SHEAR
TONIGHT.
FOR CONTINUITY, CONTINUED A CHANCE OF SHOWERS AND THUNDERSTORMS
FRIDAY AS MOST SREF MEMBERS SHOW THE BAND OF SHOWERS HAVING EXITED
BY MORNING, AND UPPER LEVEL RIDGING ACROSS THE EASTERN U.S.
INCREASING.
FORECASTED TEMPERATURES BASED ON BLEND OF RECENT GFS AND NAM MOS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
A SERIES OF SHORTWAVES MOVING ACROSS AN UPPER LEVEL RIDGE OVER THE
EAST COAST WILL PROVIDE UNSETTLED WEATHER THROUGH THE WEEKEND.
HAVE GONE WITH SLIGHT CHANCE OF THUNDERSTORMS ON SATURDAY AND
CHANCE ON SUNDAY. INCONSISTENCY STILL EXISTS BETWEEN THE NAM AND
GFS FOR THUNDERSTORMS.
TREND OF WELL ABOVE NORMAL TEMPERATURES CONTINUES INTO NEXT WEEK.
RECORD HIGH TEMPERATURES COULD BE SET IN AREAS AROUND PITTSBURGH
AND SOUTH WITH TEMPERATURES REACHING THE UPPER 70S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WEAK TROF MOVING ACROSS SOUTHERN LAKES COULD TRIGGER SCATTERED
SHOWERS OR THUNDERSTORMS FROM LATE SUNDAY THROUGH MONDAY MORNING.
GFS MAINTAINS CONSIDERABLY STRONGER SHORT WAVE THAN OTHER MODELS. AN
UPPER RIDGE WILL AMPLIFY ACROSS THE EASTERN STATES EARLY NEXT WEEK
AND REMAIN IN PLACE THROUGH WEDNESDAY. SURFACE HIGH PRESSURE IS
PROGGED TO HOLD ALONG THE MID ATLANTIC COAST AND MAINTAIN SOUTHWEST
FLOW ACROSS THE UPPER OHIO VALLEY REGION.
MUCH ABOVE NORMAL TEMPERATURES THROUGHOUT THE PERIOD WITH
TEMPERATURES AVERAGING NEARLY 20 DEGREES PER DAY ABOVE NORMAL.
NEXT FRONT APPROACHES UPPER OHIO RIVER VALLEY ON FRIDAY.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
GENERAL VFR CONDITIONS WILL PREVAIL THROUGH 16/06Z. WEAK FRONT
LOCATED ACROSS SOUTHERN GREAT LAKES WILL MOVE ACROSS REGION LATE
TONIGHT AND POSSIBLY TRIGGER SHOWERS AND SOME THUNDERSTORMS WITH
MVFR VSBY THROUGH 14Z.
AREA OF SHOWERS AND THUNDERSTORMS CURRENTLY OVER SOUTHERN OHIO AND
MOVING INTO WEST VIRGINA WILL STAY SOUTH OF CWA. APPEARS THIS
FEATURE IS TRAPPING MOST OF THE AVAILABLE MOISTURE AND WILL KEEP
LATE AFTERNOON AND EVENING CONVECTION AT A MINIMUM ACROSS CWA.
EXPECT VFR CONDITIONS FROM FRIDAY AFTERNOON THROUGH SUNDAY WITH WEAK
HIGH PRESSURE OVER REGION.
OUTLOOK...SUNDAY NIGHT THROUGH TUESDAY...
WEAK UPPER TROF MOVING THROUGH SOUTHERN GREAT LAKES LATE SUNDAY AND
SUNDAY NIGHT MAY TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS WITH
BEST CHANCE OF RESTRICTIONS ACROSS NORTHERN PA.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
926 AM EDT THU MAR 15 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM MOVING SLOWLY EASTWARD THROUGH THE GREAT
LAKES WILL PROVIDE SHOWERS AND SCATTERED THUNDERSTORMS INTO FRIDAY
NIGHT. TEMPERATURES WILL REMAIN UNSEASONABLY WARM INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE MADE TO CLOUDS AND SHOWER PROSPECTS PER RECENT RADAR AND SURFACE
DATA AND HRRR AND NAM MODEL OUTPUT. RECENT SATELLITE DATA SHOWS
THICKER CLOUDS HAVE REACHED THE MOUNTAINS. EXPECT WARM FRONTAL
BAND OF SHOWERS AND SCATTERED THUNDERSTORMS TO CONTINUE EAST INTO
WESTERN PENNSYLVANIA, BUT DECREASE IN COVERAGE.
MADE SMALL ADJUSTMENTS TO TEMPERATURES PER RECENT OBSERVED
COOLING WHERE SHOWERS HAVE RECENTLY PASSED, AND EXPECTED REBOUND
PER RECENT HRRR AND NAM MODEL OUTPUT.
7AM UPDATE... PROGRESS LINE OF THUNDERSTORMS HAS SLOWED/NEARLY
STOPPED MOVING EASTWARD AND CONVECTIONS BUILDING TO THE WEST.
LOWER DEWPOINTS EAST AND MOISTURE FLUX MORE FAVORABLE TO THE WEST.
UPDATED GRIDS TO REFLECT THE SLOWER PROGRESSION. LASTEST HRRR
TENDS TO WASH OUT THE PRECIP BY THE NOON HOUR. ADJUSTED CLOUDS
GRIDS TO REFLECT THE MID AND HIGH LEVEL CLOUDS BLOWING OFF OF THE
THUNDERSTORMS.
WILL CONTINUE A CHANCE OF SHOWERS AND THUNDERSTORMS TONIGHT.
SPC CONTINUES TO PROJECT A SLIGHT RISK OF SEVERE THUNDERSTORMS AS
FAR EAST AS THE I-77 CORRIDOR IN OHIO. RECENT RUC MODEL PROFILES
SHOW INSTABILITY DEVELOPING ALOFT TODAY. HOWEVER, VERTICAL WIND SHEAR
REMAINS WEAK, WHICH COULD PRECLUDE EXTENT OF SEVERE DEVELOPMENT.
THE THREAT OF THUNDERSTORMS WILL DIMINISH AFTER MIDNIGHT TONIGHT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
UNSETTLED PATTERN WILL PERSIST THROUGH THE MIDDLE PART OF THE
WEEKEND. AS SHORTWAVES MOVE ACROSS UPPER LEVEL RIDGE PARKED OVER THE
EAST COAST...THIS WILL TEMPORARILY ENHANCE CHANCES FOR
PRECIPITATION.
AS LOW PRESSURE MOVES EASTWARD INTO NEW ENGLAND FRIDAY
NIGHT...THIS MAY ALLOW FOR THE BEST CHANCE OF PRECIP IN THE
PERIOD. MODELS ARE SHOWING LITTLE CONSISTENCY WITH INSTABILITY FOR
THUNDERSTORMS. HAVE GENERALLY GONE WITH CHANCE STORMS DURING THE
AFTERNOON AND EVENING...AND SLIGHT CHANCE DURING THE OVERNIGHT AND
MORNING HOURS. NO CHANGE IN THE TREND OF WELL ABOVE NORMAL
TEMPERATURES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AN UPPER RIDGE WILL AMPLIFY ACROSS THE EASTERN STATES EARLY NEXT
WEEK AND REMAIN IN PLACE THROUGH WEDNESDAY. SURFACE HIGH PRESSURE IS
PROGGED TO HOLD ALONG THE MID ATLANTIC COAST AND MAINTAIN SOUTHWEST
FLOW ACROSS THE UPPER OHIO VALLEY REGION.
ISOLATED SHOWERS CAN STILL BE EXPECTED SUNDAY...WITH GENERALLY DRY
WEATHER MONDAY THROUGH WEDNESDAY. TEMPERATURES WILL REMAIN 20 TO 25
DEGREES ABOVE NORMAL FOR THE EXTENDED PERIOD.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS WILL CONTINUE ACROSS THE TERMINALS THROUGH THE TAF
PERIOD. BROKEN CUMULUS IS EXPECTED TO FORM, AROUND DAWN IN THE FAR
WEST AND LATER IN THE MORNING FOR REMAINING PORTS, AS LOW LEVEL
MOISTURE INCREASES AHEAD OF AN APPROACHING SHORTWAVE TROUGH.
CURRENT HIRES MODEL DATA IS SHOWING A LINE OF SHOWERS/ISO STORMS
DEVELOPING MOVING THROUGH OHIO BTWN 12Z AND 16Z, AND ACROSS THE
REMAINDER OF THE FORECAST AREA BTWN 16Z AND 20Z. WILL INSERT TEMPO
GROUPS AT EACH PORT TO TIME THIS ACTIVITY.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
SCATTERED SHOWERS AND THUNDERSTORMS AND THE POTENTIAL FOR
RESTRICTIONS WILL CONTINUE THROUGH EARLY SATURDAY AS THE UPPER
TROUGH AND ASSOCIATED WEAK SURFACE LOW MOVE EAST TO THE ATLANTIC
COAST. SHOWERS ARE EXPECTED TO BECOME MORE ISOLATED BY SUNDAY UNDER
WEAK RIDGING.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
140 PM EDT THU MAR 15 2012
.SYNOPSIS...
ISSUED AT 405 AM EDT THU MAR 15 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WSW FLOW ALF FM
THE PAC NW TO ONTARIO BTWN UPR RDG MOVING SLOWLY E THRU THE GREAT
LKS AND A LARGER SCALE TROF OFF THE W COAST. SFC COOL FNT ATTENDANT
TO STRONG SHRTWV LIFTING NEWD THRU HUDSON BAY IS MOVING E THRU UPR
MI EARLY THIS MRNG AND WL BRING AT LEAST A TEMPORARY END TO RECORD
WARMTH THAT ENVELOPED THE AREA ON WED...WHEN THE MERCURY PEAKED IN
THE 70S AT MANY SPOTS AND AS HI AS 77 AT KENTON. THERE WAS A SURGE
OF LLVL MSTR MOVING NEWD AHEAD OF THIS COOL FNT...AND SOME FOG AND
SC HAVE DVLPD OVER THE SE HALF OF THE CWA AHEAD OF THE COOL FNT.
ALTHOUGH THE 00Z GRB RAOB SHOWS STEEP H8-5 LAPSE RATES NOT FAR FM
DRY ADIABATIC...THE DRYNESS OF THE MID LVLS AND A SHARP INVRN NEAR
H8 THAT HAS CAPPED THE LLVL MOISTENING/DESTABILIZATION AND HELD IN
THE ABSENCE OF ANY DYNAMIC SUPPORT SO FAR S OF THE HUDSON BAY SHRTWV
HAVE CONSPIRED TO PREVENT THE DEVELOPMENT OF ANY SHRA/TS. BEHIND THE
FNT...HI PRES IN THE NRN PLAINS IS TENDING TO BUILD TO THE ENE. THE
00Z INL RAOB DEPICTS A VERY DRY LOWER TROP WITH H925/H85 DEWPT
DEPRESSIONS OF 18C/22C. SFC DEWPTS HAVE FALLEN INTO THE TEENS OVER
THE N HALF OF MN. ALTHOUGH THE COOL FNT PASSED IWD/CMX IN THE EARLY
EVNG...SFC DEWPTS THERE ARE STILL IN THE MID 30S. OVER THE S HALF OF
MN...SFC DEWPTS REMAIN AS HI AS 45 EVEN BEHIND THE FROPA. BUT EXCEPT
FOR SOME HI CLDS...SKIES ARE MOCLR AS THE 00Z MPX RAOB IS QUITE DRY
IN A RELATIVE SENSE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM EDT THU MAR 15 2012
TDAY...MAIN FCST CONCERNS IN THE SHORT TERM RELATE TO THE EXTENT OF
THE LLVL DRYING THAT WL OCCUR OVER THE CWA IN THE WAKE OF THE COOL
FNT THAT IS FCST TO CLEAR THE SE ZNS BY FCST ISSUANCE. MODELS IN
RECENT DAYS HAVE SHOWN SOME DISAGREEMENT ON THIS DRYING BECAUSE THE
FLOW ALF IS EXPECTED TO REMAIN WSW AND TAKE THE SFC HI PRES/CORE OF
THE REALLY DRY AIR NOW IN NW MN INTO ONTARIO. BUT EVEN IF THE LLVL
AIRMASS MOVING INTO UPR MI COMES FM THE DIRECTION OF MPX...THE
RELATIVE DRYNESS OF THE AIRMASS THERE IS A GOOD INDICATION LO CLDS
ARE LESS LIKELY TO DEVELOP THAN PREVIOUSLY FCST. WITH THE EXCEPTION
OF THE GFS...THE 00Z RUNS HAVE COME INTO GOOD AGREEMENT SHOWING MORE
DRYING IN THE H95-9 LYR THRU THE DAY. GIVEN THE DRYNESS/LACK OF CLDS
UPSTREAM AND DIFFLUENT NATURE OF THE FLOW...WL FOLLOW THE 00Z LOCAL
WRF-ARW THAT INDICATES MORE AGGRESSIVE LLVL DRYING AND CUT BACK ON
THE EXTENT OF THE LO CLDS. THIS MODEL DOES INDICATE SOME LO CLDS MAY
LINGER OVER THE E THIS MRNG IN THE WAKE OF THE FROPA...BUT OTRW
INDICATES THE DAY SHOULD BE MOSUNNY EXCEPT FOR SOME HI CLDS. MIXING
TO H85 ON WRF-ARW SDNGS INDICATES HI TEMPS WL TOP OUT ARND 60 OVER
LOCATIONS NEAR THE WI BORDER WELL INLAND FM LK SUP COOLING IN THE
LLVL N-NE FLOW. HI TEMPS ARE LIKELY TO HOLD IN THE 40S NEAR LK SUP E
OF THE KEWEENAW WITH ONSHORE 15KT NE H925 WINDS.
TNGT...ALTHOUGH A WEAK SHRTWV IS PROGGED TO RIPPLE THRU THE UPR
FLOW...THE MID LVLS ARE TOO DRY FOR ANY PCPN. IN FACT...FCST
SOUNDINGS INDICATE ONLY SOME HI CLDS. EXPECT A HEALTHY DIURNAL TEMP
FALL WITH LIGHT WINDS. THE LOWEST MIN TEMPS ARE LIKELY OVER THE
INTERIOR E AND CNTRL WHERE THE WINDS WL BE LIGHTEST THRU THE NGT.
INCRSG S WIND LATER AS HI PRES RDG BEGINS TO RETREAT TO THE E WL
LIKELY KEEP TEMPS A BIT ELEVATED OVER THE FAR W FM IWD TO ONTONAGON.
THE LOCAL WRF-ARW FCST SDNGS INDICATE THE BEST CHC FOR FOG WL BE
OVER THE E...WHERE A BIT MORE AMPLE LLVL MSTR WL COINCIDE WITH THE
LGT WINDS.
FRI...SFC HI CENTER IS FCST TO DRIFT INTO QUEBEC...WITH INCRSG SLY
FLOW UNDER SHARPENING PRES GRADIENT BTWN THE DEPARTING HI AND
FALLING PRES IN THE PLAINS. THE RETURN OF HIER H95-9 SPECIFIC
HUMIDITY WL RESULT IN SOME AFTN CU/SC. WITH H85 TEMPS FCST TO
REBOUND TO ARND 12C...TEMPS WL REBOUND INTO THE 60S AWAY FM LK
MODERATION...WARMEST OVER THE W WHERE THE SSE SFC FLOW DOWNSLOPES.
FRI NGT...SSW H925 WINDS INCRSG UP TO 25-35 KTS ON THE WRN FLANK OF
RETREATING HI PRES ARE FCST TO BRING MORE LLVL MSTR SURGING INTO THE
UPR LKS. ALTHOUGH MODELS GENERATE SPOTTY QPF...GFS FCST SDNGS SHOW
CAPPING INVRN LINGERING BTWN H8-75 IN THE ABSENCE OF ANY DYNAMIC
SUPPORT WITHIN UPR RDG AXIS. SO OPTED TO KEEP GOING DRY FCST. SOME
FOG IS LIKELY OVER THE E IN AREAS DOWNWIND OF LK MI EVEN THOUGH THE
STRONG WINDS/LLVL MOISTENING WL RETARD THE DIURNAL FALL OF TEMP.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM EDT THU MAR 15 2012
UPPER RIDGE WILL BE IN CONTROL OF THE REGION AT THE START OF THE
PERIOD AND CONTINUE THROUGH THE FIRST HALF OF NEXT WEEK.
AT THE SFC...AREA WILL BE BETWEEN A COLD FRONT OVER THE ERN DAKOTAS
AND SFC HIGH MOVING E INTO THE NEW ENGLAND STATES. THIS WILL ALLOW
SRLY FLOW TO BE IN PLACE AND MODELS SHOWING GOOD H950-850 MOISTURE
SURGING NNE OVER THE AREA FRI NIGHT AND INTO SAT. IF THIS MOISTURE
IS PRESENT AND LOW CLOUDS FORM...COULD BE DIFFICULT TO BREAK OUT ON
SATURDAY IF THIS OCCURS. BUT LATEST TRENDS IN NAM/GFS ARE SHOWING
MORE MIXING PRESENT AND FEEL A PARTLY CLOUDY FORECAST IS WARRENTED
FOR ALL BUT NEAR LK MI...WHERE FOG ON SAT MORNING WILL KEEP THINGS
MOSTLY CLOUDY. THIS MAKES TEMPS TRICKY...AS IT WILL DEPEND ON THE
CLOUDS BREAKING OUT. THINK THE WEST HALF HAS A BETTER CHANCE OF THIS
OCCURRING AND TRENDED TOWARDS THE WARM SIDE. MIXING TO H900 WOULD
GIVE HIGHS NEAR 70S AND HAVE FOLLOWED THAT. DEPENDING ON THE WIND
DIRECTION...WHICH IS TRENDING A LITTLE SSW...SO TRENDED TEMPS UP
THERE SLIGHTLY DUE TO DOWNSLOPE WINDS.
ONE FINAL THING OF NOTE IS THE NAM IS SHOWING DECENT
INSTABILITY...2K J/KG OF CAPE...IN THE AFTN WITH THE STRONG DIURNAL
HEATING OVER THE W HALF. OPTED TO REMAIN DRY EVEN WITH THIS
INSTABILITY POTENTIAL...BUT WILL NEED TO MONITOR.
WEAK UPPER LEVEL DISTURBANCE SATURDAY NIGHT AND SUNDAY LOOKS TO STAY
S OF THE CWA. COULD SEE SOME SHOWERS DEVELOPING WITH THIS WEEK
DISTURBANCE OVER CNTRL LK MI AND LOWER MI. MAIN FEATURE OF NOTE TO
AFFECT THE CWA IS A DECAYING COLD FRONT DROPPING OVER LK SUPERIOR
SAT NIGHT. WILL PUSH N ON SUNDAY AS A WARM FRONT AS LOW PRESSURE
ORGANIZES OVER THE NRN PLAINS. QUESTION IS HOW FAR S IT WILL SINK
BEFORE PUSHING BACK N. GFS/ECMWF/GEM STALL IT OVER LK SUPERIOR AND
MAYBE REACHING THE KEWEENAW PENINSULA. NAM TRIES TO PUSH IT A TOUCH
FARTHER S AND DEVELOP PCPN OVER MUCH OF UPPER MI. FINDING IT HARD TO
BUCK THE MODEL CONSENSUS...ESPECIALLY THAT FAR OUT ON THE NAM...SO
WILL CONFINE THE CHANCE POPS OVER LK SUPERIOR AND LK MI AND KEEP
SLIGHTS IN BETWEEN.
EXTENDED /SUNDAY NIGHT THROUGH WEDNESDAY/...
ANOMALOUS H500 HEIGHTS...AROUND 2-3 STD DEV ABOVE NORMAL FOR
MID-LATE MARCH WILL REMAIN OVER THE AREA FOR THE EXTENDED PERIOD.
TROUGH OVER AMPLIFYING AND MOVING OVER THE SW CONUS WILL AMPLIFY THE
RIDGE UPSTREAM AND LEAD TO CONTINUED WARMING UNDER SRLY FLOW KEEPING
WARM AIR IN PLACE.
WITH THE SRLY FLOW...MODELS CONTINUE TO SURGE WARM/MOIST AIR OVER
THE AREA. THIS MAKES FOR A TROUBLING FORECAST...AS IT IS LARGELY
DEPENDENT ON IF LOW CLOUDS DEVELOP BELOW THE PERSISTANT H850
INVERSION. IF THE LAST 12HRS ARE ANY INDICATION...PRODUCES SOME
DOUBT TO NORTHWARD EXTENT. BUT THE PERSISTANT SRLY FLOW WILL LIKELY
PUSH THE MOISTURE INTO THE AREA AND SHOULD LEAD TO MORE
CLOUDY/FOGGY NIGHTS WHICH WILL BREAK UP DUE TO DIURNAL HEATING.
ADDED FOG OVER LK SUPERIOR/MICHIGAN THROUGH THE EXTENDED AND BLED
IT INLAND NEAR LK MI DURING THE OVERNIGHT HOURS WITH THE SSE WINDS.
TEMPS WILL GREATLY DEPEND ON LOW CLOUDS/FOG AND DAYTIME MIXING...BUT
WILL CONTINUE TO BE WELL ABOVE NORMAL WITH MANY DAYS IN THE 60S
OVER THE WEST. COOLER VALUES OVER THE E AND ALSO PORTIONS OF THE
NCNTRL...DUE TO SSE WINDS THROUGH MUCH OF THE PERIOD.
AS FOR PCPN...MODELS CONTINUING TO SHOW LIGHT QPF ALONG AND OVER
THE GREAT LKS. WHAT IS LIKELY HAPPENING IS THAT THE ABUNDANT
MOISTURE IS TOO MUCH IN THE LOW LEVELS AND THE MODELS ARE TRYING TO
RELIEVE THEMSELVES OF THIS EXCESS MOISTURE. WILL LIKELY BE FOG IN
THESE AREAS DUE TO THE MOIST AIR OVER THE COOL GREAT LKS...BUT
DON/T SEE MUCH CHANCES FOR SHOWERS WITH THE STRONG H850 CAP. IF
ANYTHING...A FOG/DZ COMBINATION WOULD OCCUR. THUS...HAVE REMOVED
MUCH OF THE SLIGHT CHANCES FROM SUN NIGHT ON.
MODELS SHOWING THE UPPER RIDGE STARTING TO SHIFT E AS THE UPPER
TROUGH STARTS TO BECOME CUT OFF ON WED. HOW THIS LOW EVOLVES WILL
AFFECT THE FORECAST FOR THE END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 137 PM EDT THU MAR 15 2012
EXPECT VFR CONDITIONS INTO FRIDAY WITH LIGHT WINDS...SCT-BKN MID-HIGH
LEVEL CLOUDINESS AND NO RESTRICTION TO VSBY. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 AM EDT THU MAR 15 2012
EXPECT WINDS TO BE MOSTLY UNDER 20 KTS THROUGH THIS WEEKEND AS A
RELATIVELY WEAK PRES GRADIENT DOMINATES. ALTHOUGH A SHARPER PRES
GRADIENT/STRONGER S FLOW WILL DEVELOP OVER THE WEEKEND...THE
UNSEASONABLY WARM AIR OVER THE UPPER GREAT LAKES WILL ALSO RESULT IN
PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE LAKE...HELPING TO
KEEP SURFACE WINDS ON THE LIGHTER SIDE. AT SOME POINT...FOG MAY
BECOME AN ISSUE...ESPECIALLY IF SOME RAINFALL OCCURS OVER THE LAKE.
RIGHT NOW...IT APPEARS DRY WEATHER SHOULD GENERALLY DOMINATE...
KEEPING FOG POTENTIAL LIMITED.
&&
.HYDROLOGY...
ISSUED AT 405 AM EDT THU MAR 15 2012
WELL ABOVE NORMAL TEMPERATURES OVER THE LAST SEVERAL DAYS...
ESPECIALLY ON WED...ALONG WITH RAIN OF 0.10 TO MORE THAN 0.5 INCH ON
MON HAS LED TO INCREASED SNOWMELT/RUNOFF. THIS RUNOFF HAS PRODUCED
SOME RISE IN LEVELS OF RIVERS IN UPR MI OVER THE LAST COUPLE OF DAYS.
ABOVE NORMAL TEMPERATURES INTO NEXT WEEK WILL CONTINUE TO MELT THE
SNOW PACK AND LEAD TO FURTHER INCREASES IN RIVER AND STREAM LEVELS.
ALTHOUGH A COOLER/DRIER AIRMASS WILL ARRIVE TODAY AND SLOW THE
MELTING...EXPECT SOME OF THE RIVERS ACROSS THE AREA TO EXCEED THEIR
BANKS BY THE END OF THIS WEEK. FORTUNATELY...THE LACK OF ANY
SIGNIFICANT RAIN IN THE FORECAST FOR THE NEXT WEEK WILL LOWER THE
CHANCE OF SIGNIFICANT FLOODING. BUT 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.
DID HAVE AN APPARENT ICE JAM ON THE ONTONAGON RIVER NEAR ROCKLAND
MON EVENING. THIS CAUSED THE RIVER LEVELS TO RISE 4FT BEFORE IT
BROKE FREE. WILL NEED TO MONITOR CONDITIONS ALONG THE ONTONAGON
RIVER OVER THE NEXT DAY OR TWO...AS THE NUMEROUS BENDS COULD CAUSE
THE ICE TO FORM ANOTHER JAM. IN ADDITION...ICE WAS REPORTED ON THE
FORD RIVER AT HYDE AND THE MOUTH AT LK MI. DEPENDING ON THE BREAKUP
OF THE ICE...THERE IS A POTENTIAL FOR MORE ICE JAMS INTO THIS
WEEKEND...WHEN THE RIVER ICE MAY CLEAR COMPLETELY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...JLA
MARINE...KC
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
734 AM EDT THU MAR 15 2012
.SYNOPSIS...
ISSUED AT 405 AM EDT THU MAR 15 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WSW FLOW ALF FM
THE PAC NW TO ONTARIO BTWN UPR RDG MOVING SLOWLY E THRU THE GREAT
LKS AND A LARGER SCALE TROF OFF THE W COAST. SFC COOL FNT ATTENDANT
TO STRONG SHRTWV LIFTING NEWD THRU HUDSON BAY IS MOVING E THRU UPR
MI EARLY THIS MRNG AND WL BRING AT LEAST A TEMPORARY END TO RECORD
WARMTH THAT ENVELOPED THE AREA ON WED...WHEN THE MERCURY PEAKED IN
THE 70S AT MANY SPOTS AND AS HI AS 77 AT KENTON. THERE WAS A SURGE
OF LLVL MSTR MOVING NEWD AHEAD OF THIS COOL FNT...AND SOME FOG AND
SC HAVE DVLPD OVER THE SE HALF OF THE CWA AHEAD OF THE COOL FNT.
ALTHOUGH THE 00Z GRB RAOB SHOWS STEEP H8-5 LAPSE RATES NOT FAR FM
DRY ADIABATIC...THE DRYNESS OF THE MID LVLS AND A SHARP INVRN NEAR
H8 THAT HAS CAPPED THE LLVL MOISTENING/DESTABILIZATION AND HELD IN
THE ABSENCE OF ANY DYNAMIC SUPPORT SO FAR S OF THE HUDSON BAY SHRTWV
HAVE CONSPIRED TO PREVENT THE DEVELOPMENT OF ANY SHRA/TS. BEHIND THE
FNT...HI PRES IN THE NRN PLAINS IS TENDING TO BUILD TO THE ENE. THE
00Z INL RAOB DEPICTS A VERY DRY LOWER TROP WITH H925/H85 DEWPT
DEPRESSIONS OF 18C/22C. SFC DEWPTS HAVE FALLEN INTO THE TEENS OVER
THE N HALF OF MN. ALTHOUGH THE COOL FNT PASSED IWD/CMX IN THE EARLY
EVNG...SFC DEWPTS THERE ARE STILL IN THE MID 30S. OVER THE S HALF OF
MN...SFC DEWPTS REMAIN AS HI AS 45 EVEN BEHIND THE FROPA. BUT EXCEPT
FOR SOME HI CLDS...SKIES ARE MOCLR AS THE 00Z MPX RAOB IS QUITE DRY
IN A RELATIVE SENSE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM EDT THU MAR 15 2012
TDAY...MAIN FCST CONCERNS IN THE SHORT TERM RELATE TO THE EXTENT OF
THE LLVL DRYING THAT WL OCCUR OVER THE CWA IN THE WAKE OF THE COOL
FNT THAT IS FCST TO CLEAR THE SE ZNS BY FCST ISSUANCE. MODELS IN
RECENT DAYS HAVE SHOWN SOME DISAGREEMENT ON THIS DRYING BECAUSE THE
FLOW ALF IS EXPECTED TO REMAIN WSW AND TAKE THE SFC HI PRES/CORE OF
THE REALLY DRY AIR NOW IN NW MN INTO ONTARIO. BUT EVEN IF THE LLVL
AIRMASS MOVING INTO UPR MI COMES FM THE DIRECTION OF MPX...THE
RELATIVE DRYNESS OF THE AIRMASS THERE IS A GOOD INDICATION LO CLDS
ARE LESS LIKELY TO DEVELOP THAN PREVIOUSLY FCST. WITH THE EXCEPTION
OF THE GFS...THE 00Z RUNS HAVE COME INTO GOOD AGREEMENT SHOWING MORE
DRYING IN THE H95-9 LYR THRU THE DAY. GIVEN THE DRYNESS/LACK OF CLDS
UPSTREAM AND DIFFLUENT NATURE OF THE FLOW...WL FOLLOW THE 00Z LOCAL
WRF-ARW THAT INDICATES MORE AGGRESSIVE LLVL DRYING AND CUT BACK ON
THE EXTENT OF THE LO CLDS. THIS MODEL DOES INDICATE SOME LO CLDS MAY
LINGER OVER THE E THIS MRNG IN THE WAKE OF THE FROPA...BUT OTRW
INDICATES THE DAY SHOULD BE MOSUNNY EXCEPT FOR SOME HI CLDS. MIXING
TO H85 ON WRF-ARW SDNGS INDICATES HI TEMPS WL TOP OUT ARND 60 OVER
LOCATIONS NEAR THE WI BORDER WELL INLAND FM LK SUP COOLING IN THE
LLVL N-NE FLOW. HI TEMPS ARE LIKELY TO HOLD IN THE 40S NEAR LK SUP E
OF THE KEWEENAW WITH ONSHORE 15KT NE H925 WINDS.
TNGT...ALTHOUGH A WEAK SHRTWV IS PROGGED TO RIPPLE THRU THE UPR
FLOW...THE MID LVLS ARE TOO DRY FOR ANY PCPN. IN FACT...FCST
SOUNDINGS INDICATE ONLY SOME HI CLDS. EXPECT A HEALTHY DIURNAL TEMP
FALL WITH LIGHT WINDS. THE LOWEST MIN TEMPS ARE LIKELY OVER THE
INTERIOR E AND CNTRL WHERE THE WINDS WL BE LIGHTEST THRU THE NGT.
INCRSG S WIND LATER AS HI PRES RDG BEGINS TO RETREAT TO THE E WL
LIKELY KEEP TEMPS A BIT ELEVATED OVER THE FAR W FM IWD TO ONTONAGON.
THE LOCAL WRF-ARW FCST SDNGS INDICATE THE BEST CHC FOR FOG WL BE
OVER THE E...WHERE A BIT MORE AMPLE LLVL MSTR WL COINCIDE WITH THE
LGT WINDS.
FRI...SFC HI CENTER IS FCST TO DRIFT INTO QUEBEC...WITH INCRSG SLY
FLOW UNDER SHARPENING PRES GRADIENT BTWN THE DEPARTING HI AND
FALLING PRES IN THE PLAINS. THE RETURN OF HIER H95-9 SPECIFIC
HUMIDITY WL RESULT IN SOME AFTN CU/SC. WITH H85 TEMPS FCST TO
REBOUND TO ARND 12C...TEMPS WL REBOUND INTO THE 60S AWAY FM LK
MODERATION...WARMEST OVER THE W WHERE THE SSE SFC FLOW DOWNSLOPES.
FRI NGT...SSW H925 WINDS INCRSG UP TO 25-35 KTS ON THE WRN FLANK OF
RETREATING HI PRES ARE FCST TO BRING MORE LLVL MSTR SURGING INTO THE
UPR LKS. ALTHOUGH MODELS GENERATE SPOTTY QPF...GFS FCST SDNGS SHOW
CAPPING INVRN LINGERING BTWN H8-75 IN THE ABSENCE OF ANY DYNAMIC
SUPPORT WITHIN UPR RDG AXIS. SO OPTED TO KEEP GOING DRY FCST. SOME
FOG IS LIKELY OVER THE E IN AREAS DOWNWIND OF LK MI EVEN THOUGH THE
STRONG WINDS/LLVL MOISTENING WL RETARD THE DIURNAL FALL OF TEMP.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM EDT THU MAR 15 2012
UPPER RIDGE WILL BE IN CONTROL OF THE REGION AT THE START OF THE
PERIOD AND CONTINUE THROUGH THE FIRST HALF OF NEXT WEEK.
AT THE SFC...AREA WILL BE BETWEEN A COLD FRONT OVER THE ERN DAKOTAS
AND SFC HIGH MOVING E INTO THE NEW ENGLAND STATES. THIS WILL ALLOW
SRLY FLOW TO BE IN PLACE AND MODELS SHOWING GOOD H950-850 MOISTURE
SURGING NNE OVER THE AREA FRI NIGHT AND INTO SAT. IF THIS MOISTURE
IS PRESENT AND LOW CLOUDS FORM...COULD BE DIFFICULT TO BREAK OUT ON
SATURDAY IF THIS OCCURS. BUT LATEST TRENDS IN NAM/GFS ARE SHOWING
MORE MIXING PRESENT AND FEEL A PARTLY CLOUDY FORECAST IS WARRENTED
FOR ALL BUT NEAR LK MI...WHERE FOG ON SAT MORNING WILL KEEP THINGS
MOSTLY CLOUDY. THIS MAKES TEMPS TRICKY...AS IT WILL DEPEND ON THE
CLOUDS BREAKING OUT. THINK THE WEST HALF HAS A BETTER CHANCE OF THIS
OCCURRING AND TRENDED TOWARDS THE WARM SIDE. MIXING TO H900 WOULD
GIVE HIGHS NEAR 70S AND HAVE FOLLOWED THAT. DEPENDING ON THE WIND
DIRECTION...WHICH IS TRENDING A LITTLE SSW...SO TRENDED TEMPS UP
THERE SLIGHTLY DUE TO DOWNSLOPE WINDS.
ONE FINAL THING OF NOTE IS THE NAM IS SHOWING DECENT
INSTABILITY...2K J/KG OF CAPE...IN THE AFTN WITH THE STRONG DIURNAL
HEATING OVER THE W HALF. OPTED TO REMAIN DRY EVEN WITH THIS
INSTABILITY POTENTIAL...BUT WILL NEED TO MONITOR.
WEAK UPPER LEVEL DISTURBANCE SATURDAY NIGHT AND SUNDAY LOOKS TO STAY
S OF THE CWA. COULD SEE SOME SHOWERS DEVELOPING WITH THIS WEEK
DISTURBANCE OVER CNTRL LK MI AND LOWER MI. MAIN FEATURE OF NOTE TO
AFFECT THE CWA IS A DECAYING COLD FRONT DROPPING OVER LK SUPERIOR
SAT NIGHT. WILL PUSH N ON SUNDAY AS A WARM FRONT AS LOW PRESSURE
ORGANIZES OVER THE NRN PLAINS. QUESTION IS HOW FAR S IT WILL SINK
BEFORE PUSHING BACK N. GFS/ECMWF/GEM STALL IT OVER LK SUPERIOR AND
MAYBE REACHING THE KEWEENAW PENINSULA. NAM TRIES TO PUSH IT A TOUCH
FARTHER S AND DEVELOP PCPN OVER MUCH OF UPPER MI. FINDING IT HARD TO
BUCK THE MODEL CONSENSUS...ESPECIALLY THAT FAR OUT ON THE NAM...SO
WILL CONFINE THE CHANCE POPS OVER LK SUPERIOR AND LK MI AND KEEP
SLIGHTS IN BETWEEN.
EXTENDED /SUNDAY NIGHT THROUGH WEDNESDAY/...
ANOMALOUS H500 HEIGHTS...AROUND 2-3 STD DEV ABOVE NORMAL FOR
MID-LATE MARCH WILL REMAIN OVER THE AREA FOR THE EXTENDED PERIOD.
TROUGH OVER AMPLIFYING AND MOVING OVER THE SW CONUS WILL AMPLIFY THE
RIDGE UPSTREAM AND LEAD TO CONTINUED WARMING UNDER SRLY FLOW KEEPING
WARM AIR IN PLACE.
WITH THE SRLY FLOW...MODELS CONTINUE TO SURGE WARM/MOIST AIR OVER
THE AREA. THIS MAKES FOR A TROUBLING FORECAST...AS IT IS LARGELY
DEPENDENT ON IF LOW CLOUDS DEVELOP BELOW THE PERSISTANT H850
INVERSION. IF THE LAST 12HRS ARE ANY INDICATION...PRODUCES SOME
DOUBT TO NORTHWARD EXTENT. BUT THE PERSISTANT SRLY FLOW WILL LIKELY
PUSH THE MOISTURE INTO THE AREA AND SHOULD LEAD TO MORE
CLOUDY/FOGGY NIGHTS WHICH WILL BREAK UP DUE TO DIURNAL HEATING.
ADDED FOG OVER LK SUPERIOR/MICHIGAN THROUGH THE EXTENDED AND BLED
IT INLAND NEAR LK MI DURING THE OVERNIGHT HOURS WITH THE SSE WINDS.
TEMPS WILL GREATLY DEPEND ON LOW CLOUDS/FOG AND DAYTIME MIXING...BUT
WILL CONTINUE TO BE WELL ABOVE NORMAL WITH MANY DAYS IN THE 60S
OVER THE WEST. COOLER VALUES OVER THE E AND ALSO PORTIONS OF THE
NCNTRL...DUE TO SSE WINDS THROUGH MUCH OF THE PERIOD.
AS FOR PCPN...MODELS CONTINUING TO SHOW LIGHT QPF ALONG AND OVER
THE GREAT LKS. WHAT IS LIKELY HAPPENING IS THAT THE ABUNDANT
MOISTURE IS TOO MUCH IN THE LOW LEVELS AND THE MODELS ARE TRYING TO
RELIEVE THEMSELVES OF THIS EXCESS MOISTURE. WILL LIKELY BE FOG IN
THESE AREAS DUE TO THE MOIST AIR OVER THE COOL GREAT LKS...BUT
DON/T SEE MUCH CHANCES FOR SHOWERS WITH THE STRONG H850 CAP. IF
ANYTHING...A FOG/DZ COMBINATION WOULD OCCUR. THUS...HAVE REMOVED
MUCH OF THE SLIGHT CHANCES FROM SUN NIGHT ON.
MODELS SHOWING THE UPPER RIDGE STARTING TO SHIFT E AS THE UPPER
TROUGH STARTS TO BECOME CUT OFF ON WED. HOW THIS LOW EVOLVES WILL
AFFECT THE FORECAST FOR THE END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 731 AM EDT THU MAR 15 2012
ALTHOUGH SOME HI CLDS WL FILTER THRU THE UPR GRT LKS...EXPECT VFR
CONDITIONS THIS FORECAST PERIOD WITH DRY HI PRES DOMINATING. WINDS
WL BE GENERALLY LGT BUT WITH A STEADIER LK BREEZE DURING THIS
AFTN... ESPECIALLY AT SAW AND CMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 AM EDT THU MAR 15 2012
EXPECT WINDS TO BE MOSTLY UNDER 20 KTS THROUGH THIS WEEKEND AS A
RELATIVELY WEAK PRES GRADIENT DOMINATES. ALTHOUGH A SHARPER PRES
GRADIENT/STRONGER S FLOW WILL DEVELOP OVER THE WEEKEND...THE
UNSEASONABLY WARM AIR OVER THE UPPER GREAT LAKES WILL ALSO RESULT IN
PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE LAKE...HELPING TO
KEEP SURFACE WINDS ON THE LIGHTER SIDE. AT SOME POINT...FOG MAY
BECOME AN ISSUE...ESPECIALLY IF SOME RAINFALL OCCURS OVER THE LAKE.
RIGHT NOW...IT APPEARS DRY WEATHER SHOULD GENERALLY DOMINATE...
KEEPING FOG POTENTIAL LIMITED.
&&
.HYDROLOGY...
ISSUED AT 405 AM EDT THU MAR 15 2012
WELL ABOVE NORMAL TEMPERATURES OVER THE LAST SEVERAL DAYS...
ESPECIALLY ON WED...ALONG WITH RAIN OF 0.10 TO MORE THAN 0.5 INCH ON
MON HAS LED TO INCREASED SNOWMELT/RUNOFF. THIS RUNOFF HAS PRODUCED
SOME RISE IN LEVELS OF RIVERS IN UPR MI OVER THE LAST COUPLE OF DAYS.
ABOVE NORMAL TEMPERATURES INTO NEXT WEEK WILL CONTINUE TO MELT THE
SNOW PACK AND LEAD TO FURTHER INCREASES IN RIVER AND STREAM LEVELS.
ALTHOUGH A COOLER/DRIER AIRMASS WILL ARRIVE TODAY AND SLOW THE
MELTING...EXPECT SOME OF THE RIVERS ACROSS THE AREA TO EXCEED THEIR
BANKS BY THE END OF THIS WEEK. FORTUNATELY...THE LACK OF ANY
SIGNIFICANT RAIN IN THE FORECAST FOR THE NEXT WEEK WILL LOWER THE
CHANCE OF SIGNIFICANT FLOODING. BUT 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.
DID HAVE AN APPARENT ICE JAM ON THE ONTONAGON RIVER NEAR ROCKLAND
MON EVENING. THIS CAUSED THE RIVER LEVELS TO RISE 4FT BEFORE IT
BROKE FREE. WILL NEED TO MONITOR CONDITIONS ALONG THE ONTONAGON
RIVER OVER THE NEXT DAY OR TWO...AS THE NUMEROUS BENDS COULD CAUSE
THE ICE TO FORM ANOTHER JAM. IN ADDITION...ICE WAS REPORTED ON THE
FORD RIVER AT HYDE AND THE MOUTH AT LK MI. DEPENDING ON THE BREAKUP
OF THE ICE...THERE IS A POTENTIAL FOR MORE ICE JAMS INTO THIS
WEEKEND...WHEN THE RIVER ICE MAY CLEAR COMPLETELY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
409 AM EDT THU MAR 15 2012
.SYNOPSIS...
ISSUED AT 405 AM EDT THU MAR 15 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WSW FLOW ALF FM
THE PAC NW TO ONTARIO BTWN UPR RDG MOVING SLOWLY E THRU THE GREAT
LKS AND A LARGER SCALE TROF OFF THE W COAST. SFC COOL FNT ATTENDANT
TO STRONG SHRTWV LIFTING NEWD THRU HUDSON BAY IS MOVING E THRU UPR
MI EARLY THIS MRNG AND WL BRING AT LEAST A TEMPORARY END TO RECORD
WARMTH THAT ENVELOPED THE AREA ON WED...WHEN THE MERCURY PEAKED IN
THE 70S AT MANY SPOTS AND AS HI AS 77 AT KENTON. THERE WAS A SURGE
OF LLVL MSTR MOVING NEWD AHEAD OF THIS COOL FNT...AND SOME FOG AND
SC HAVE DVLPD OVER THE SE HALF OF THE CWA AHEAD OF THE COOL FNT.
ALTHOUGH THE 00Z GRB RAOB SHOWS STEEP H8-5 LAPSE RATES NOT FAR FM
DRY ADIABATIC...THE DRYNESS OF THE MID LVLS AND A SHARP INVRN NEAR
H8 THAT HAS CAPPED THE LLVL MOISTENING/DESTABILIZATION AND HELD IN
THE ABSENCE OF ANY DYNAMIC SUPPORT SO FAR S OF THE HUDSON BAY SHRTWV
HAVE CONSPIRED TO PREVENT THE DEVELOPMENT OF ANY SHRA/TS. BEHIND THE
FNT...HI PRES IN THE NRN PLAINS IS TENDING TO BUILD TO THE ENE. THE
00Z INL RAOB DEPICTS A VERY DRY LOWER TROP WITH H925/H85 DEWPT
DEPRESSIONS OF 18C/22C. SFC DEWPTS HAVE FALLEN INTO THE TEENS OVER
THE N HALF OF MN. ALTHOUGH THE COOL FNT PASSED IWD/CMX IN THE EARLY
EVNG...SFC DEWPTS THERE ARE STILL IN THE MID 30S. OVER THE S HALF OF
MN...SFC DEWPTS REMAIN AS HI AS 45 EVEN BEHIND THE FROPA. BUT EXCEPT
FOR SOME HI CLDS...SKIES ARE MOCLR AS THE 00Z MPX RAOB IS QUITE DRY
IN A RELATIVE SENSE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM EDT THU MAR 15 2012
TDAY...MAIN FCST CONCERNS IN THE SHORT TERM RELATE TO THE EXTENT OF
THE LLVL DRYING THAT WL OCCUR OVER THE CWA IN THE WAKE OF THE COOL
FNT THAT IS FCST TO CLEAR THE SE ZNS BY FCST ISSUANCE. MODELS IN
RECENT DAYS HAVE SHOWN SOME DISAGREEMENT ON THIS DRYING BECAUSE THE
FLOW ALF IS EXPECTED TO REMAIN WSW AND TAKE THE SFC HI PRES/CORE OF
THE REALLY DRY AIR NOW IN NW MN INTO ONTARIO. BUT EVEN IF THE LLVL
AIRMASS MOVING INTO UPR MI COMES FM THE DIRECTION OF MPX...THE
RELATIVE DRYNESS OF THE AIRMASS THERE IS A GOOD INDICATION LO CLDS
ARE LESS LIKELY TO DEVELOP THAN PREVIOUSLY FCST. WITH THE EXCEPTION
OF THE GFS...THE 00Z RUNS HAVE COME INTO GOOD AGREEMENT SHOWING MORE
DRYING IN THE H95-9 LYR THRU THE DAY. GIVEN THE DRYNESS/LACK OF CLDS
UPSTREAM AND DIFFLUENT NATURE OF THE FLOW...WL FOLLOW THE 00Z LOCAL
WRF-ARW THAT INDICATES MORE AGGRESSIVE LLVL DRYING AND CUT BACK ON
THE EXTENT OF THE LO CLDS. THIS MODEL DOES INDICATE SOME LO CLDS MAY
LINGER OVER THE E THIS MRNG IN THE WAKE OF THE FROPA...BUT OTRW
INDICATES THE DAY SHOULD BE MOSUNNY EXCEPT FOR SOME HI CLDS. MIXING
TO H85 ON WRF-ARW SDNGS INDICATES HI TEMPS WL TOP OUT ARND 60 OVER
LOCATIONS NEAR THE WI BORDER WELL INLAND FM LK SUP COOLING IN THE
LLVL N-NE FLOW. HI TEMPS ARE LIKELY TO HOLD IN THE 40S NEAR LK SUP E
OF THE KEWEENAW WITH ONSHORE 15KT NE H925 WINDS.
TNGT...ALTHOUGH A WEAK SHRTWV IS PROGGED TO RIPPLE THRU THE UPR
FLOW...THE MID LVLS ARE TOO DRY FOR ANY PCPN. IN FACT...FCST
SOUNDINGS INDICATE ONLY SOME HI CLDS. EXPECT A HEALTHY DIURNAL TEMP
FALL WITH LIGHT WINDS. THE LOWEST MIN TEMPS ARE LIKELY OVER THE
INTERIOR E AND CNTRL WHERE THE WINDS WL BE LIGHTEST THRU THE NGT.
INCRSG S WIND LATER AS HI PRES RDG BEGINS TO RETREAT TO THE E WL
LIKELY KEEP TEMPS A BIT ELEVATED OVER THE FAR W FM IWD TO ONTONAGON.
THE LOCAL WRF-ARW FCST SDNGS INDICATE THE BEST CHC FOR FOG WL BE
OVER THE E...WHERE A BIT MORE AMPLE LLVL MSTR WL COINCIDE WITH THE
LGT WINDS.
FRI...SFC HI CENTER IS FCST TO DRIFT INTO QUEBEC...WITH INCRSG SLY
FLOW UNDER SHARPENING PRES GRADIENT BTWN THE DEPARTING HI AND
FALLING PRES IN THE PLAINS. THE RETURN OF HIER H95-9 SPECIFIC
HUMIDITY WL RESULT IN SOME AFTN CU/SC. WITH H85 TEMPS FCST TO
REBOUND TO ARND 12C...TEMPS WL REBOUND INTO THE 60S AWAY FM LK
MODERATION...WARMEST OVER THE W WHERE THE SSE SFC FLOW DOWNSLOPES.
FRI NGT...SSW H925 WINDS INCRSG UP TO 25-35 KTS ON THE WRN FLANK OF
RETREATING HI PRES ARE FCST TO BRING MORE LLVL MSTR SURGING INTO THE
UPR LKS. ALTHOUGH MODELS GENERATE SPOTTY QPF...GFS FCST SDNGS SHOW
CAPPING INVRN LINGERING BTWN H8-75 IN THE ABSENCE OF ANY DYNAMIC
SUPPORT WITHIN UPR RDG AXIS. SO OPTED TO KEEP GOING DRY FCST. SOME
FOG IS LIKELY OVER THE E IN AREAS DOWNWIND OF LK MI EVEN THOUGH THE
STRONG WINDS/LLVL MOISTENING WL RETARD THE DIURNAL FALL OF TEMP.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM EDT THU MAR 15 2012
UPPER RIDGE WILL BE IN CONTROL OF THE REGION AT THE START OF THE
PERIOD AND CONTINUE THROUGH THE FIRST HALF OF NEXT WEEK.
AT THE SFC...AREA WILL BE BETWEEN A COLD FRONT OVER THE ERN DAKOTAS
AND SFC HIGH MOVING E INTO THE NEW ENGLAND STATES. THIS WILL ALLOW
SRLY FLOW TO BE IN PLACE AND MODELS SHOWING GOOD H950-850 MOISTURE
SURGING NNE OVER THE AREA FRI NIGHT AND INTO SAT. IF THIS MOISTURE
IS PRESENT AND LOW CLOUDS FORM...COULD BE DIFFICULT TO BREAK OUT ON
SATURDAY IF THIS OCCURS. BUT LATEST TRENDS IN NAM/GFS ARE SHOWING
MORE MIXING PRESENT AND FEEL A PARTLY CLOUDY FORECAST IS WARRENTED
FOR ALL BUT NEAR LK MI...WHERE FOG ON SAT MORNING WILL KEEP THINGS
MOSTLY CLOUDY. THIS MAKES TEMPS TRICKY...AS IT WILL DEPEND ON THE
CLOUDS BREAKING OUT. THINK THE WEST HALF HAS A BETTER CHANCE OF THIS
OCCURRING AND TRENDED TOWARDS THE WARM SIDE. MIXING TO H900 WOULD
GIVE HIGHS NEAR 70S AND HAVE FOLLOWED THAT. DEPENDING ON THE WIND
DIRECTION...WHICH IS TRENDING A LITTLE SSW...SO TRENDED TEMPS UP
THERE SLIGHTLY DUE TO DOWNSLOPE WINDS.
ONE FINAL THING OF NOTE IS THE NAM IS SHOWING DECENT
INSTABILITY...2K J/KG OF CAPE...IN THE AFTN WITH THE STRONG DIURNAL
HEATING OVER THE W HALF. OPTED TO REMAIN DRY EVEN WITH THIS
INSTABILITY POTENTIAL...BUT WILL NEED TO MONITOR.
WEAK UPPER LEVEL DISTURBANCE SATURDAY NIGHT AND SUNDAY LOOKS TO STAY
S OF THE CWA. COULD SEE SOME SHOWERS DEVELOPING WITH THIS WEEK
DISTURBANCE OVER CNTRL LK MI AND LOWER MI. MAIN FEATURE OF NOTE TO
AFFECT THE CWA IS A DECAYING COLD FRONT DROPPING OVER LK SUPERIOR
SAT NIGHT. WILL PUSH N ON SUNDAY AS A WARM FRONT AS LOW PRESSURE
ORGANIZES OVER THE NRN PLAINS. QUESTION IS HOW FAR S IT WILL SINK
BEFORE PUSHING BACK N. GFS/ECMWF/GEM STALL IT OVER LK SUPERIOR AND
MAYBE REACHING THE KEWEENAW PENINSULA. NAM TRIES TO PUSH IT A TOUCH
FARTHER S AND DEVELOP PCPN OVER MUCH OF UPPER MI. FINDING IT HARD TO
BUCK THE MODEL CONSENSUS...ESPECIALLY THAT FAR OUT ON THE NAM...SO
WILL CONFINE THE CHANCE POPS OVER LK SUPERIOR AND LK MI AND KEEP
SLIGHTS IN BETWEEN.
EXTENDED /SUNDAY NIGHT THROUGH WEDNESDAY/...
ANOMALOUS H500 HEIGHTS...AROUND 2-3 STD DEV ABOVE NORMAL FOR
MID-LATE MARCH WILL REMAIN OVER THE AREA FOR THE EXTENDED PERIOD.
TROUGH OVER AMPLIFYING AND MOVING OVER THE SW CONUS WILL AMPLIFY THE
RIDGE UPSTREAM AND LEAD TO CONTINUED WARMING UNDER SRLY FLOW KEEPING
WARM AIR IN PLACE.
WITH THE SRLY FLOW...MODELS CONTINUE TO SURGE WARM/MOIST AIR OVER
THE AREA. THIS MAKES FOR A TROUBLING FORECAST...AS IT IS LARGELY
DEPENDENT ON IF LOW CLOUDS DEVELOP BELOW THE PERSISTANT H850
INVERSION. IF THE LAST 12HRS ARE ANY INDICATION...PRODUCES SOME
DOUBT TO NORTHWARD EXTENT. BUT THE PERSISTANT SRLY FLOW WILL LIKELY
PUSH THE MOISTURE INTO THE AREA AND SHOULD LEAD TO MORE
CLOUDY/FOGGY NIGHTS WHICH WILL BREAK UP DUE TO DIURNAL HEATING.
ADDED FOG OVER LK SUPERIOR/MICHIGAN THROUGH THE EXTENDED AND BLED
IT INLAND NEAR LK MI DURING THE OVERNIGHT HOURS WITH THE SSE WINDS.
TEMPS WILL GREATLY DEPEND ON LOW CLOUDS/FOG AND DAYTIME MIXING...BUT
WILL CONTINUE TO BE WELL ABOVE NORMAL WITH MANY DAYS IN THE 60S
OVER THE WEST. COOLER VALUES OVER THE E AND ALSO PORTIONS OF THE
NCNTRL...DUE TO SSE WINDS THROUGH MUCH OF THE PERIOD.
AS FOR PCPN...MODELS CONTINUING TO SHOW LIGHT QPF ALONG AND OVER
THE GREAT LKS. WHAT IS LIKELY HAPPENING IS THAT THE ABUNDANT
MOISTURE IS TOO MUCH IN THE LOW LEVELS AND THE MODELS ARE TRYING TO
RELIEVE THEMSELVES OF THIS EXCESS MOISTURE. WILL LIKELY BE FOG IN
THESE AREAS DUE TO THE MOIST AIR OVER THE COOL GREAT LKS...BUT
DON/T SEE MUCH CHANCES FOR SHOWERS WITH THE STRONG H850 CAP. IF
ANYTHING...A FOG/DZ COMBINATION WOULD OCCUR. THUS...HAVE REMOVED
MUCH OF THE SLIGHT CHANCES FROM SUN NIGHT ON.
MODELS SHOWING THE UPPER RIDGE STARTING TO SHIFT E AS THE UPPER
TROUGH STARTS TO BECOME CUT OFF ON WED. HOW THIS LOW EVOLVES WILL
AFFECT THE FORECAST FOR THE END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1259 AM EDT THU MAR 15 2012
VFR CONDITIONS WILL CONTINUE TO DOMINATE THROUGH THE PERIOD AT ALL 3
SITES UNDER A VERY DRY AIRMASS. LAKE BREEZES WILL KICK IN AT ALL 3
SITES ON THU AND MAKE THE WIND MORE NERLY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 AM EDT THU MAR 15 2012
EXPECT WINDS TO BE MOSTLY UNDER 20 KTS THROUGH THIS WEEKEND AS A
RELATIVELY WEAK PRES GRADIENT DOMINATES. ALTHOUGH A SHARPER PRES
GRADIENT/STRONGER S FLOW WILL DEVELOP OVER THE WEEKEND...THE
UNSEASONABLY WARM AIR OVER THE UPPER GREAT LAKES WILL ALSO RESULT IN
PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE LAKE...HELPING TO
KEEP SURFACE WINDS ON THE LIGHTER SIDE. AT SOME POINT...FOG MAY
BECOME AN ISSUE...ESPECIALLY IF SOME RAINFALL OCCURS OVER THE LAKE.
RIGHT NOW...IT APPEARS DRY WEATHER SHOULD GENERALLY DOMINATE...
KEEPING FOG POTENTIAL LIMITED.
&&
.HYDROLOGY...
ISSUED AT 405 AM EDT THU MAR 15 2012
WELL ABOVE NORMAL TEMPERATURES OVER THE LAST SEVERAL DAYS...
ESPECIALLY ON WED...ALONG WITH RAIN OF 0.10 TO MORE THAN 0.5 INCH ON
MON HAS LED TO INCREASED SNOWMELT/RUNOFF. THIS RUNOFF HAS PRODUCED
SOME RISE IN LEVELS OF RIVERS IN UPR MI OVER THE LAST COUPLE OF DAYS.
ABOVE NORMAL TEMPERATURES INTO NEXT WEEK WILL CONTINUE TO MELT THE
SNOW PACK AND LEAD TO FURTHER INCREASES IN RIVER AND STREAM LEVELS.
ALTHOUGH A COOLER/DRIER AIRMASS WILL ARRIVE TODAY AND SLOW THE
MELTING...EXPECT SOME OF THE RIVERS ACROSS THE AREA TO EXCEED THEIR
BANKS BY THE END OF THIS WEEK. FORTUNATELY...THE LACK OF ANY
SIGNIFICANT RAIN IN THE FORECAST FOR THE NEXT WEEK WILL LOWER THE
CHANCE OF SIGNIFICANT FLOODING. BUT 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.
DID HAVE AN APPARENT ICE JAM ON THE ONTONAGON RIVER NEAR ROCKLAND
MON EVENING. THIS CAUSED THE RIVER LEVELS TO RISE 4FT BEFORE IT
BROKE FREE. WILL NEED TO MONITOR CONDITIONS ALONG THE ONTONAGON
RIVER OVER THE NEXT DAY OR TWO...AS THE NUMEROUS BENDS COULD CAUSE
THE ICE TO FORM ANOTHER JAM. IN ADDITION...ICE WAS REPORTED ON THE
FORD RIVER AT HYDE AND THE MOUTH AT LK MI. DEPENDING ON THE BREAKUP
OF THE ICE...THERE IS A POTENTIAL FOR MORE ICE JAMS INTO THIS
WEEKEND...WHEN THE RIVER ICE MAY CLEAR COMPLETELY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...07
MARINE...KC
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
329 PM CDT THU MAR 15 2012
.SHORT TERM...
ISSUED AT 325 PM CDT THU MAR 15 2012
(TONIGHT)
MAIN CONVECTIVE THREAT SHOULD BE THIS EVENING...AND PRIMARILY OVER
S SECTIONS OF THE CWA...ALONG AND AHEAD OF BLOSSOMING CONVECTION
ACROSS THE OZARKS. MEANWHILE...HAVE CONTINUED CHANCE POPS OVER N
SECTIONS OF THE FA. NOT CERTAIN THAT MUCH PRECIP WILL BE ABLE TO
DEVELOP THAT FAR N...BUT INSTABILITY...LOW CIN...AND UPSTREAM
SHORTWAVE WARRANTS CONTINUING MENTION OF TSRA. TEMPERATURES SHOULD
REMAIN UNSEASONABLY MILD...AND RANGE FROM THE UPPER 50S TO LOWER 60S.
TRUETT
&&
.LONG TERM...
ISSUED AT 259 PM CDT THU MAR 15 2012
(FRIDAY THROUGH NEXT THURSDAY)
NOT MUCH HAS CHANGED IN MDL SOLNS FROM YESTERDAY. MDLS STILL SUGGEST
REGION REMAINS IN A SIMILAR AIRMASS INTO THE WEEKEND. MDLS PROG H85
TEMPS TO REMAIN IN THE 12C TO 14C RANGE. SCT TSRA DURING THE
AFTERNOON INTO THE EVENING AND AGAIN JUST BEFORE AND AFTER SUNRISE.
HAVE THEREFORE KEPT PERSISTENCE FORECAST GOING INTO SUN WITH ONLY
MINOR TWEAKS FROM DAY TO DAY. SAT NIGHT DOES HAVE SOME UNCERTAINTY
REGARDING TEMPS/POPS. MDLS CONTINUE TO DEPICT MCS/MCV ON SAT INTO
SAT NIGHT MOVING NEWD INTO/NEAR THE CWA. MDLS AGREE ON THE
OCCURRENCE OF THIS FEATURE. HOWEVER...TIMING AND TRACK DIFFER. TEMPS
ON SAT AND POSSIBLY INTO SUN WILL GREATLY DEPEND ON WHICH SOLN
VERIFIES.
LIKEWISE...THE GOING MAX TEMPS ARE BASED ON EXPECTING ISOD TO SCT
TSRA...DEPENDING ON LOCATION IN THE CWA. BELIEVE BEST CHANCES FOR
MULTICELL CLUSTERS WILL BE OUTSIDE OF THE CWA. HOWEVER...IF THE
LOCATION CHANGES...TEMPS WILL HAVE TO BE ALTERED IN FUTURE UPDATES
TO ACCOUNT FOR THIS.
AS FOR SVR CHANCES...WITH SAME THINKING AS MENTIONED ABOVE...AN ISOD
SVR TSRA WILL BE POSSIBLE INTO THE WEEKEND. MDLS PROG MLCAPE AROUND
2000 J/KG WITH STEEP MID LVL LAPSE RATES. DEEP LAYER SHEER WILL BE
DIMINISHED...LIMITING ORGANIZED THREAT.
FOR THE EXTD...PERSISTENCE TRENDS CONTINUE EARLY INTO THE PERIOD.
MDLS CONTINUE TO DEPICT LEE CYCLOGENESIS ON DEEP TROF CROSSING THE
ROCKIES MON INTO TUES. THIS SYSTEM WILL BEGIN TO AFFECT THE CWA AS
EARLY AS MON AND A NUMBER OF S/WS EJECT INTO THE PLAINS INCREASING
THE CHANCE OF TSRA ACROSS THE AREA.
MDLS AGREE WITH A CUT OFF LOW DEVELOPING AND EVENTUALLY IMPACTING
THE CWA. HOWEVER...MDLS DISAGREE REGARDING TIMING. FOR NOW...HAVE
CONTINUED LOWER END CHANCE POPS AND WILL INCREASE AS CONFIDENCE
INCREASES.
HAVE CONTINUED WARM TREND THRU THE EXTD PERIOD...BUT TEMPS ARE
EXPECTED TO BE COOLER WED INTO THURS AS CUT OFF LOW APPROACHES AND
SPREADS PRECIP/CLOUDS INTO THE REGION.
TILLY
&&
.AVIATION...
ISSUED AT 1234 PM CDT THU MAR 15 2012
THIS MORNINGS CONVECTIVE CLUSTER PUSHING INTO S IL ATTM...SO
FORECAST TRENDS FOR THIS AFTERNOON DEAL WITH REDEVELOPMENT IN THE
WAKE OF THIS SYSTEM. AMS IS MODERATLY UNSTABLE WITH LITTLE
CIN...SO EXPECT HIT AND MISS CONVECTION DURING THE AFTERNOON. ATTM
NOT CERTAIN IF AND/OR WHERE THE MAIN COVERAGE OF THIS AFTERNOONS
CONVECTION WILL BE...ALTHOUGH HRRR DATA HAS BEEN HINTING THAT THE
SOMEWHAT BETTER FOCUS FOR STORMS WILL BE FROM THE EASTERN OZARKS
THROUGH THE STL AREA. FOR NOW HAVE HIGHLIGHTED TS THREAT WITH CB
CLOUD GROUP ALG AND S OF I-70 CORRIDOR. HAVE ALSO KEPT CB GROUP
GOING INTO THE EVENING...AS THERE SEEMS TO BE SOME MODEL CONSENSUS
THAT SHORTWAVE CURRENTLY OVER OK WILL KEEP SOME THREAT GOING PAST
MAX HEATING. FINALLY...GIVEN PERSISTENT S FLOW AND CONDITIONS OVER
THE PLAINS AROUND DAYBREAK THIS MORNING...HAVE INTRODUCED A BIT OF
FOG AND STRATUS FOR EARLY FRIDAY MORNING...PRIMARILY IN UIN AND
COU.
SPECIFICS FOR KSTL...TAF ATTEMPTS TO REFLECT AN AMS-TYPE TSRA
THREAT WITH A BKN CU FIELD...VCSH...AND CB CLOUD GROUP...AND WILL
REFINE THIS IF/WHEN CONVECTIVE TRENDS BECOME A BIT BETTER DEFINED.
AS MENTIONED ABOVE...HAVE ALSO HELD ONTO CB CLOUD GROUP PAST MAX
HEATING AND THROUGHOUT THE EVENING DUE TO UPSTREAM SHORTWAVE.
TRUETT
&&
.CLIMATE...
HERE ARE THE RECORD HIGH MAXIMUM AND HIGH MINIMUM TEMPERATURES
FOR KSTL AND KCOU FOR THURSDAY 03/15 AND FRIDAY 03/16.
KSTL
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 80F 1945 60F 1919
FRI 03/16 86F 1945 57F 1919
KCOU
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 79F 1914 62F 1919
FRI 03/16 87F 1945 55F 1945
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 63 85 65 85 / 40 30 20 40
QUINCY 60 83 59 83 / 30 20 20 40
COLUMBIA 61 82 60 82 / 30 20 20 50
JEFFERSON CITY 61 82 63 82 / 30 20 20 50
SALEM 61 80 62 80 / 50 40 30 40
FARMINGTON 61 81 62 81 / 60 40 30 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
301 PM CDT THU MAR 15 2012
.SHORT TERM...
ISSUED AT 345 AM CDT THU MAR 15 2012
(TODAY AND TONIGHT)
LITTLE CHANGE IN THINKING SINCE PREVIOUS FORECAST. TEMPERATURES
WARMED UP ABOVE GUIDANCE YET AGAIN ON WEDNESDAY...AND I SEE NO
REASON NOT TO GO ABOVE GUIDANCE AGAIN TODAY. AM LESS CONFIDENT IN
MID 80S TODAY THAN YESTERDAY THOUGH SINCE CONVECTION MAY BE MORE
WIDESPREAD ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE CWFA AS A
SHORTWAVE RIPPLES EAST OUT OF THE PLAINS INTO THE MID-MISSISSIPPI
VALLEY. WENT 2-3 DEGREES WARMER THAN WARMEST MAV GUIDANCE ACROSS
MOST OF THE AREA. HAVE INCREASED POPS ACROSS SOUTHERN SECTIONS TO
LIKELY AS WELL TO BETTER REPRESENT THE PROPOSED TRACK OF THE
SHORTWAVE. SHOULD SEE CONVECTION DIMINISH DURING THE EVENING SINCE
THE WAVE MOVES EAST AND THERE DOESN`T APPEAR TO BE MUCH FORCING TO
MAINTAIN STORMS ESPECIALLY AFTER MIDNIGHT.
CARNEY
&&
.LONG TERM...
ISSUED AT 259 PM CDT THU MAR 15 2012
(FRIDAY THROUGH NEXT THURSDAY)
NOT MUCH HAS CHANGED IN MDL SOLNS FROM YESTERDAY. MDLS STILL SUGGEST
REGION REMAINS IN A SIMILAR AIRMASS INTO THE WEEKEND. MDLS PROG H85
TEMPS TO REMAIN IN THE 12C TO 14C RANGE. SCT TSRA DURING THE
AFTERNOON INTO THE EVENING AND AGAIN JUST BEFORE AND AFTER SUNRISE.
HAVE THEREFORE KEPT PERSISTENCE FORECAST GOING INTO SUN WITH ONLY
MINOR TWEAKS FROM DAY TO DAY. SAT NIGHT DOES HAVE SOME UNCERTAINTY
REGARDING TEMPS/POPS. MDLS CONTINUE TO DEPICT MCS/MCV ON SAT INTO
SAT NIGHT MOVING NEWD INTO/NEAR THE CWA. MDLS AGREE ON THE
OCCURRENCE OF THIS FEATURE. HOWEVER...TIMING AND TRACK DIFFER. TEMPS
ON SAT AND POSSIBLY INTO SUN WILL GREATLY DEPEND ON WHICH SOLN
VERIFIES.
LIKEWISE...THE GOING MAX TEMPS ARE BASED ON EXPECTING ISOD TO SCT
TSRA...DEPENDING ON LOCATION IN THE CWA. BELIEVE BEST CHANCES FOR
MULTICELL CLUSTERS WILL BE OUTSIDE OF THE CWA. HOWEVER...IF THE
LOCATION CHANGES...TEMPS WILL HAVE TO BE ALTERED IN FUTURE UPDATES
TO ACCOUNT FOR THIS.
AS FOR SVR CHANCES...WITH SAME THINKING AS MENTIONED ABOVE...AN ISOD
SVR TSRA WILL BE POSSIBLE INTO THE WEEKEND. MDLS PROG MLCAPE AROUND
2000 J/KG WITH STEEP MID LVL LAPSE RATES. DEEP LAYER SHEER WILL BE
DIMINISHED...LIMITING ORGANIZED THREAT.
FOR THE EXTD...PERSISTENCE TRENDS CONTINUE EARLY INTO THE PERIOD.
MDLS CONTINUE TO DEPICT LEE CYCLOGENESIS ON DEEP TROF CROSSING THE
ROCKIES MON INTO TUES. THIS SYSTEM WILL BEGIN TO AFFECT THE CWA AS
EARLY AS MON AND A NUMBER OF S/WS EJECT INTO THE PLAINS INCREASING
THE CHANCE OF TSRA ACROSS THE AREA.
MDLS AGREE WITH A CUT OFF LOW DEVELOPING AND EVENTUALLY IMPACTING
THE CWA. HOWEVER...MDLS DISAGREE REGARDING TIMING. FOR NOW...HAVE
CONTINUED LOWER END CHANCE POPS AND WILL INCREASE AS CONFIDENCE
INCREASES.
HAVE CONTINUED WARM TREND THRU THE EXTD PERIOD...BUT TEMPS ARE
EXPECTED TO BE COOLER WED INTO THURS AS CUT OFF LOW APPROACHES AND
SPREADS PRECIP/CLOUDS INTO THE REGION.
TILLY
&&
.AVIATION...
ISSUED AT 1234 PM CDT THU MAR 15 2012
THIS MORNINGS CONVECTIVE CLUSTER PUSHING INTO S IL ATTM...SO
FORECAST TRENDS FOR THIS AFTERNOON DEAL WITH REDEVELOPMENT IN THE
WAKE OF THIS SYSTEM. AMS IS MODERATLY UNSTABLE WITH LITTLE
CIN...SO EXPECT HIT AND MISS CONVECTION DURING THE AFTERNOON. ATTM
NOT CERTAIN IF AND/OR WHERE THE MAIN COVERAGE OF THIS AFTERNOONS
CONVECTION WILL BE...ALTHOUGH HRRR DATA HAS BEEN HINTING THAT THE
SOMEWHAT BETTER FOCUS FOR STORMS WILL BE FROM THE EASTERN OZARKS
THROUGH THE STL AREA. FOR NOW HAVE HIGHLIGHTED TS THREAT WITH CB
CLOUD GROUP ALG AND S OF I-70 CORRIDOR. HAVE ALSO KEPT CB GROUP
GOING INTO THE EVENING...AS THERE SEEMS TO BE SOME MODEL CONSENSUS
THAT SHORTWAVE CURRENTLY OVER OK WILL KEEP SOME THREAT GOING PAST
MAX HEATING. FINALLY...GIVEN PERSISTENT S FLOW AND CONDITIONS OVER
THE PLAINS AROUND DAYBREAK THIS MORNING...HAVE INTRODUCED A BIT OF
FOG AND STRATUS FOR EARLY FRIDAY MORNING...PRIMARILY IN UIN AND
COU.
SPECIFICS FOR KSTL...TAF ATTEMPTS TO REFLECT AN AMS-TYPE TSRA
THREAT WITH A BKN CU FIELD...VCSH...AND CB CLOUD GROUP...AND WILL
REFINE THIS IF/WHEN CONVECTIVE TRENDS BECOME A BIT BETTER DEFINED.
AS MENTIONED ABOVE...HAVE ALSO HELD ONTO CB CLOUD GROUP PAST MAX
HEATING AND THROUGHOUT THE EVENING DUE TO UPSTREAM SHORTWAVE.
TRUETT
&&
.CLIMATE...
HERE ARE THE RECORD HIGH MAXIMUM AND HIGH MINIMUM TEMPERATURES
FOR KSTL AND KCOU FOR THURSDAY 03/15 AND FRIDAY 03/16.
KSTL
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 80F 1945 60F 1919
FRI 03/16 86F 1945 57F 1919
KCOU
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 79F 1914 62F 1919
FRI 03/16 87F 1945 55F 1945
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 63 85 65 85 / 40 30 20 40
QUINCY 60 83 59 83 / 30 20 20 40
COLUMBIA 61 82 60 82 / 40 20 20 50
JEFFERSON CITY 61 82 63 82 / 40 20 20 50
SALEM 61 80 62 80 / 40 40 30 40
FARMINGTON 61 81 62 81 / 40 40 30 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
140 PM CDT THU MAR 15 2012
.UPDATE...
ISSUED AT 135 PM CDT THU MAR 15 2012
AFTERNOON CONVECTION IS NOW SHOWING ITS HAND. BASED ON TRENDS THE
LAST 45 MINUTES IT WOULD APPEAR THAT BEST COVERAGE OF STORMS WILL
BE ALONG AND SOUTH OF A KIH...CPS...1H2 LINE...ALTHOUGH AM
CERTAINLY NOT DISCOUNTING DEVELOMENT FURTHER N WITH MUCAPES
2000-2500 AND LITTLE IF ANY CIN. ALSO TWEEKED TEMPS DOWN A BIT IN
THE FAR S...WHERE TEMPS ARE STRUGGLING TO RECOVER FROM THE MORNING
CONVECTION.
TRUETT
&&
.SHORT TERM...
ISSUED AT 345 AM CDT THU MAR 15 2012
(TODAY AND TONIGHT)
LITTLE CHANGE IN THINKING SINCE PREVIOUS FORECAST. TEMPERATURES
WARMED UP ABOVE GUIDANCE YET AGAIN ON WEDNESDAY...AND I SEE NO
REASON NOT TO GO ABOVE GUIDANCE AGAIN TODAY. AM LESS CONFIDENT IN
MID 80S TODAY THAN YESTERDAY THOUGH SINCE CONVECTION MAY BE MORE
WIDESPREAD ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE CWFA AS A
SHORTWAVE RIPPLES EAST OUT OF THE PLAINS INTO THE MID-MISSISSIPPI
VALLEY. WENT 2-3 DEGREES WARMER THAN WARMEST MAV GUIDANCE ACROSS
MOST OF THE AREA. HAVE INCREASED POPS ACROSS SOUTHERN SECTIONS TO
LIKELY AS WELL TO BETTER REPRESENT THE PROPOSED TRACK OF THE
SHORTWAVE. SHOULD SEE CONVECTION DIMINISH DURING THE EVENING SINCE
THE WAVE MOVES EAST AND THERE DOESN`T APPEAR TO BE MUCH FORCING TO
MAINTAIN STORMS ESPECIALLY AFTER MIDNIGHT.
CARNEY
&&
.LONG TERM...
ISSUED AT 345 AM CDT THU MAR 15 2012
(FRIDAY THROUGH WEDNESDAY)
LITTLE CHANGE IN THINKING SINCE PREVIOUS FORECAST. TEMPERATURES
WARMED UP ABOVE GUIDANCE YET AGAIN ON WEDNESDAY...AND I SEE NO
REASON NOT TO GO ABOVE GUIDANCE AGAIN TODAY. AM LESS CONFIDENT IN
MID 80S TODAY THAN YESTERDAY THOUGH SINCE CONVECTION MAY BE MORE
WIDESPREAD ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE CWFA AS A
SHORTWAVE RIPPLES EAST OUT OF THE PLAINS INTO THE MID-MISSISSIPPI
VALLEY. WENT 2-3 DEGREES WARMER THAN WARMEST MAV GUIDANCE ACROSS
MOST OF THE AREA. HAVE INCREASED POPS ACROSS SOUTHERN SECTIONS TO
LIKELY AS WELL TO BETTER REPRESENT THE PROPOSED TRACK OF THE
SHORTWAVE. SHOULD SEE CONVECTION DIMINISH DURING THE EVENING SINCE
THE WAVE MOVES EAST AND THERE DOESN`T APPEAR TO BE MUCH FORCING TO
MAINTAIN STORMS ESPECIALLY AFTER MIDNIGHT.
CONTINUING THE IDEA OF ISOLATED TO WIDELY SCATTERED CONVECTION EACH
DAY THROUGH THE WEEKEND AS SOUTHWEST FLOW CONTINUES OVER THE AREA.
THE BEST CHANCE LOOKS LIKE SATURDAY WHEN ANOTHER WELL DEFINED
SHORTWAVE RIPPLES OUT OF THE SOUTHERN PLAINS ACROSS MISSOURI. NOT
QUITE READY TO INCREASE POPS ABOVE CHANCE SINCE THE STRENGTH OF THE
WAVE MAY BE DUE TO CONVECTIVE FEEDBACK...BUT LIKELY POPS WOULD BE
VERY APPROPRIATE IF SUBSEQUENT MODEL RUNS CONTINUE TO SHOW THIS
WAVE. MEDIUM RANGE MODELS STILL SHOW THE FLOW UNDERGOING
EYE-POPPING AMPLIFICATION SUNDAY INTO MONDAY AS A DEEP LONGWAVE TROF
DEVELOPS OVER THE WESTERN U.S. AND A RIDGE AMPLIFIES OVER THE
APPALACHIANS. SHOULD SEE RAIN CHANCES FALL OFF AS THIS OCCURS SINCE
WE`LL BE CLOSER TO THE RIDGE AXIS THAN THE TROF. HOWEVER...BOTH THE
ECMWF AND GFS SHOW A TREMENDOUS AMOUNT OF LOW LEVEL MOISTURE
CONVERGENCE SPREADING ACROSS WESTERN MISSOURI BY 00Z TUESDAY...WITH
AN IMPRESSIVE AMOUNT OF QPF ASSOCIATED WITH IT. IT DOESN`T QUITE
GET INTO OUR CENTRAL MISSOURI COUNTIES...BUT I THINK IT`S TOO CLOSE
TO PULL OUT CHANCES IN CENTRAL MO AT THIS TIME. SHOULD SEE THOSE
CHANCE POPS OVERSPREAD THE REST OF THE AREA AS THE TROF STARTS TO
SLOWLY MOVE EAST...THOUGH AM NOT SURE ON TIMING AT THIS JUNCTURE.
THIS IS CERTAINLY AN UNSEASONABLE PATTERN...SO CONFIDENCE IN THE
FORECAST FOR NEXT WEEK IS PRETTY LOW.
CARNEY
&&
.AVIATION...
ISSUED AT 1234 PM CDT THU MAR 15 2012
THIS MORNINGS CONVECTIVE CLUSTER PUSHING INTO S IL ATTM...SO
FORECAST TRENDS FOR THIS AFTERNOON DEAL WITH REDEVELOPMENT IN THE
WAKE OF THIS SYSTEM. AMS IS MODERATLY UNSTABLE WITH LITTLE
CIN...SO EXPECT HIT AND MISS CONVECTION DURING THE AFTERNOON. ATTM
NOT CERTAIN IF AND/OR WHERE THE MAIN COVERAGE OF THIS AFTERNOONS
CONVECTION WILL BE...ALTHOUGH HRRR DATA HAS BEEN HINTING THAT THE
SOMEWHAT BETTER FOCUS FOR STORMS WILL BE FROM THE EASTERN OZARKS
THROUGH THE STL AREA. FOR NOW HAVE HIGHLIGHTED TS THREAT WITH CB
CLOUD GROUP ALG AND S OF I-70 CORRIDOR. HAVE ALSO KEPT CB GROUP
GOING INTO THE EVENING...AS THERE SEEMS TO BE SOME MODEL CONSENSUS
THAT SHORTWAVE CURRENTLY OVER OK WILL KEEP SOME THREAT GOING PAST
MAX HEATING. FINALLY...GIVEN PERSISTENT S FLOW AND CONDITIONS OVER
THE PLAINS AROUND DAYBREAK THIS MORNING...HAVE INTRODUCED A BIT OF
FOG AND STRATUS FOR EARLY FRIDAY MORNING...PRIMARILY IN UIN AND
COU.
SPECIFICS FOR KSTL...TAF ATTEMPTS TO REFLECT AN AMS-TYPE TSRA
THREAT WITH A BKN CU FIELD...VCSH...AND CB CLOUD GROUP...AND WILL
REFINE THIS IF/WHEN CONVECTIVE TRENDS BECOME A BIT BETTER DEFINED.
AS MENTIONED ABOVE...HAVE ALSO HELD ONTO CB CLOUD GROUP PAST MAX
HEATING AND THROUGHOUT THE EVENING DUE TO UPSTREAM SHORTWAVE.
TRUETT
&&
.CLIMATE...
HERE ARE THE RECORD HIGH MAXIMUM AND HIGH MINIMUM TEMPERATURES
FOR KSTL AND KCOU FOR THURSDAY 03/15 AND FRIDAY 03/16.
KSTL
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 80F 1945 60F 1919
FRI 03/16 86F 1945 57F 1919
KCOU
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 79F 1914 62F 1919
FRI 03/16 87F 1945 55F 1945
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 85 61 85 65 / 40 40 30 20
QUINCY 82 60 83 59 / 30 30 20 20
COLUMBIA 82 60 82 60 / 40 40 20 20
JEFFERSON CITY 82 58 82 63 / 40 40 20 20
SALEM 75 59 80 62 / 50 40 40 30
FARMINGTON 73 59 81 62 / 60 40 40 30
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1246 PM CDT THU MAR 15 2012
.SHORT TERM...
ISSUED AT 345 AM CDT THU MAR 15 2012
(TODAY AND TONIGHT)
LITTLE CHANGE IN THINKING SINCE PREVIOUS FORECAST. TEMPERATURES
WARMED UP ABOVE GUIDANCE YET AGAIN ON WEDNESDAY...AND I SEE NO
REASON NOT TO GO ABOVE GUIDANCE AGAIN TODAY. AM LESS CONFIDENT IN
MID 80S TODAY THAN YESTERDAY THOUGH SINCE CONVECTION MAY BE MORE
WIDESPREAD ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE CWFA AS A
SHORTWAVE RIPPLES EAST OUT OF THE PLAINS INTO THE MID-MISSISSIPPI
VALLEY. WENT 2-3 DEGREES WARMER THAN WARMEST MAV GUIDANCE ACROSS
MOST OF THE AREA. HAVE INCREASED POPS ACROSS SOUTHERN SECTIONS TO
LIKELY AS WELL TO BETTER REPRESENT THE PROPOSED TRACK OF THE
SHORTWAVE. SHOULD SEE CONVECTION DIMINISH DURING THE EVENING SINCE
THE WAVE MOVES EAST AND THERE DOESN`T APPEAR TO BE MUCH FORCING TO
MAINTAIN STORMS ESPECIALLY AFTER MIDNIGHT.
CARNEY
&&
.LONG TERM...
ISSUED AT 345 AM CDT THU MAR 15 2012
(FRIDAY THROUGH WEDNESDAY)
LITTLE CHANGE IN THINKING SINCE PREVIOUS FORECAST. TEMPERATURES
WARMED UP ABOVE GUIDANCE YET AGAIN ON WEDNESDAY...AND I SEE NO
REASON NOT TO GO ABOVE GUIDANCE AGAIN TODAY. AM LESS CONFIDENT IN
MID 80S TODAY THAN YESTERDAY THOUGH SINCE CONVECTION MAY BE MORE
WIDESPREAD ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE CWFA AS A
SHORTWAVE RIPPLES EAST OUT OF THE PLAINS INTO THE MID-MISSISSIPPI
VALLEY. WENT 2-3 DEGREES WARMER THAN WARMEST MAV GUIDANCE ACROSS
MOST OF THE AREA. HAVE INCREASED POPS ACROSS SOUTHERN SECTIONS TO
LIKELY AS WELL TO BETTER REPRESENT THE PROPOSED TRACK OF THE
SHORTWAVE. SHOULD SEE CONVECTION DIMINISH DURING THE EVENING SINCE
THE WAVE MOVES EAST AND THERE DOESN`T APPEAR TO BE MUCH FORCING TO
MAINTAIN STORMS ESPECIALLY AFTER MIDNIGHT.
CONTINUING THE IDEA OF ISOLATED TO WIDELY SCATTERED CONVECTION EACH
DAY THROUGH THE WEEKEND AS SOUTHWEST FLOW CONTINUES OVER THE AREA.
THE BEST CHANCE LOOKS LIKE SATURDAY WHEN ANOTHER WELL DEFINED
SHORTWAVE RIPPLES OUT OF THE SOUTHERN PLAINS ACROSS MISSOURI. NOT
QUITE READY TO INCREASE POPS ABOVE CHANCE SINCE THE STRENGTH OF THE
WAVE MAY BE DUE TO CONVECTIVE FEEDBACK...BUT LIKELY POPS WOULD BE
VERY APPROPRIATE IF SUBSEQUENT MODEL RUNS CONTINUE TO SHOW THIS
WAVE. MEDIUM RANGE MODELS STILL SHOW THE FLOW UNDERGOING
EYE-POPPING AMPLIFICATION SUNDAY INTO MONDAY AS A DEEP LONGWAVE TROF
DEVELOPS OVER THE WESTERN U.S. AND A RIDGE AMPLIFIES OVER THE
APPALACHIANS. SHOULD SEE RAIN CHANCES FALL OFF AS THIS OCCURS SINCE
WE`LL BE CLOSER TO THE RIDGE AXIS THAN THE TROF. HOWEVER...BOTH THE
ECMWF AND GFS SHOW A TREMENDOUS AMOUNT OF LOW LEVEL MOISTURE
CONVERGENCE SPREADING ACROSS WESTERN MISSOURI BY 00Z TUESDAY...WITH
AN IMPRESSIVE AMOUNT OF QPF ASSOCIATED WITH IT. IT DOESN`T QUITE
GET INTO OUR CENTRAL MISSOURI COUNTIES...BUT I THINK IT`S TOO CLOSE
TO PULL OUT CHANCES IN CENTRAL MO AT THIS TIME. SHOULD SEE THOSE
CHANCE POPS OVERSPREAD THE REST OF THE AREA AS THE TROF STARTS TO
SLOWLY MOVE EAST...THOUGH AM NOT SURE ON TIMING AT THIS JUNCTURE.
THIS IS CERTAINLY AN UNSEASONABLE PATTERN...SO CONFIDENCE IN THE
FORECAST FOR NEXT WEEK IS PRETTY LOW.
CARNEY
&&
.AVIATION...
ISSUED AT 1234 PM CDT THU MAR 15 2012
THIS MORNINGS CONVECTIVE CLUSTER PUSHING INTO S IL ATTM...SO
FORECAST TRENDS FOR THIS AFTERNOON DEAL WITH REDEVELOPMENT IN THE
WAKE OF THIS SYSTEM. AMS IS MODERATLY UNSTABLE WITH LITTLE
CIN...SO EXPECT HIT AND MISS CONVECTION DURING THE AFTERNOON. ATTM
NOT CERTAIN IF AND/OR WHERE THE MAIN COVERAGE OF THIS AFTERNOONS
CONVECTION WILL BE...ALTHOUGH HRRR DATA HAS BEEN HINTING THAT THE
SOMEWHAT BETTER FOCUS FOR STORMS WILL BE FROM THE EASTERN OZARKS
THROUGH THE STL AREA. FOR NOW HAVE HIGHLIGHTED TS THREAT WITH CB
CLOUD GROUP ALG AND S OF I-70 CORRIDOR. HAVE ALSO KEPT CB GROUP
GOING INTO THE EVENING...AS THERE SEEMS TO BE SOME MODEL CONSENSUS
THAT SHORTWAVE CURRENTLY OVER OK WILL KEEP SOME THREAT GOING PAST
MAX HEATING. FINALLY...GIVEN PERSISTENT S FLOW AND CONDITIONS OVER
THE PLAINS AROUND DAYBREAK THIS MORNING...HAVE INTRODUCED A BIT OF
FOG AND STRATUS FOR EARLY FRIDAY MORNING...PRIMARILY IN UIN AND
COU.
SPECIFICS FOR KSTL...TAF ATTEMPTS TO REFLECT AN AMS-TYPE TSRA
THREAT WITH A BKN CU FIELD...VCSH...AND CB CLOUD GROUP...AND WILL
REFINE THIS IF/WHEN CONVECTIVE TRENDS BECOME A BIT BETTER DEFINED.
AS MENTIONED ABOVE...HAVE ALSO HELD ONTO CB CLOUD GROUP PAST MAX
HEATING AND THROUGHOUT THE EVENING DUE TO UPSTREAM SHORTWAVE.
TRUETT
&&
.CLIMATE...
HERE ARE THE RECORD HIGH MAXIMUM AND HIGH MINIMUM TEMPERATURES
FOR KSTL AND KCOU FOR THURSDAY 03/15 AND FRIDAY 03/16.
KSTL
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 80F 1945 60F 1919
FRI 03/16 86F 1945 57F 1919
KCOU
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 79F 1914 62F 1919
FRI 03/16 87F 1945 55F 1945
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 85 61 85 65 / 40 40 30 20
QUINCY 83 60 83 59 / 30 30 20 20
COLUMBIA 82 60 82 60 / 40 40 20 20
JEFFERSON CITY 82 58 82 63 / 40 40 20 20
SALEM 80 59 80 62 / 50 40 40 30
FARMINGTON 81 59 81 62 / 60 40 40 30
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1230 AM CDT THU MAR 15 2012
...UPDATE TO AVIATION...
.UPDATE...
THE 00Z NAM AND RUC CONTINUE TO INDICATE A SIGNAL FOR ISOLATED TO
WIDELY SCATTERED CONVECTIVE DEVELOPMENT LATE TONIGHT. BOTH MODELS
NOSE A WEAK CORRIDOR OF ISENTROPIC UPGLIDE IN THE 300-305 K LAYER
INTO THE REGION BEGINNING AROUND OR JUST AFTER 09Z. LIFTING
PARCELS FROM THIS SAME LAYER YIELDS LITTLE IF ANY CONVECTIVE
INHIBITION...ESPECIALLY ALONG AND SOUTH OF A PITTSBURG KANSAS TO
LAKE OF THE OZARKS LINE. THE GOING POPS HAVE THIS COVERED WELL.
DESPITE 0-6 KM EFFECTIVE BULK SHEARS AT OR BELOW 20 KNOTS...
MUCAPES IN THE 1800 TO 2400 J/KG RANGE WILL STILL SUPPORT SOME
HAIL POTENTIAL. DID ADD A LIMITED HAIL THREAT TO THE HAZARDOUS
WEATHER OUTLOOK.
SCHAUMANN
&&
.DISCUSSION...
/ISSUED 1255 PM CDT WED MAR 14 2012/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
FOR THE NEAR TERM THIS AFTERNOON...SCATTERED CU CONTINUE TO BUBBLE
UP ACROSS THE REGION...AS COMBINATION OF INCREASING TEMPERATURES AND
NEAR 60 DEWPOINTS HAS ERODED MUCH OF THE INHIBITION EVIDENT ON THIS
MORNING`S 12Z RAOB. DESPITE THIS...DRY AIR ALOFT (ALSO PER 12Z
SOUNDING) AND HIGH LFCS...ALONG WITH NEARLY NON-EXISTENT LOW LEVEL
FORCING SHOULD RESULT IN VERY LOW CONVECTIVE COVERAGE...THIS
AFTERNOON/EARLY EVENING. CURRENT THINKING REMAINS THAT HIGHER
TERRAIN OF THE BOSTON MOUNTAINS AND FAR SOUTH-CENTRAL MO WILL SERVE
AS THE INITIAL FOCUS FOR CONVECTION THIS AFTERNOON. STEEP LAPSE
RATES ALOFT AND THE AFOREMENTIONED DRY AIR COULD LEAD TO A FEW
MARGINALLY SEVERE HAIL AND WIND REPORTS WITH THE STRONGEST
STORMS...BUT AGAIN...COVERAGE SHOULD BE QUITE SPARSE.
EXPECT TO SEE MUCH OF THE CONVECTION DIMINISH WITH SUNSET TONIGHT.
A MORE ORGANIZED WAVE WILL APPROACH THE AREA TOWARD THE MORNING
HOURS TOMORROW...WITH AN ASSOCIATED UPTICK IN SHOWERS/THUNDERSTORMS
EXPECTED. THINK WE`LL SEE A FEW WAVES OF CONVECTION THROUGHOUT THE
DAY ON THURSDAY AS A 60 KT BRANCH OF THE SUBTROPICAL JET NOSES INTO
THE AREA. 0-6 KM SHEAR VALUES THURSDAY SHOULD BE IN THE 20-25 KT
RANGE...SUFFICIENT FOR AT LEAST OCCASIONAL CONVECTIVE ORGANIZATION.
INSTABILITY FORECASTS ARE A PROBLEM FOR TOMORROW...WITH VERY LOW
CONFIDENCE IN THE AMOUNT OF BREAKS IN THE CLOUDS.
OBVIOUSLY...AVAILABLE INSTABILITY WILL RISE CONSIDERABLY IF WE DO
SEE OCCASIONAL SUNSHINE DURING THE DAY. OVERALL...THINK THE SEVERE
THREAT IS LIMITED...WITH JUST AN ISOLATED WIND GUST AND/OR LARGE
HAIL REPORT EXPECTED. TEMPERATURES WILL ALSO BE TRICKY TOMORROW.
FOR NOW HAVE GONE A LITTLE ON THE COOL SIDE OF GUIDANCE (MID TO
UPPER 70S)...BUT IF A LITTLE MORE SUNSHINE THAN EXPECTED PEAKS
THROUGH THE CLOUDS...THEN READING APPROACHING OR PERHAPS EVEN
EXCEEDING 80 IN A FEW AREAS WON`T BE OUT OF THE QUESTION.
SIMILAR CONDITIONS TO TODAY ARE EXPECTED FOR FRIDAY...AS ADDITIONAL
WEAK RIPPLES PASS THROUGH IN SOUTHWEST FLOW. TEMPERATURES FOR
FRIDAY SHOULD AGAIN APPROACH THE 80 DEGREE MARK IN MANY
LOCATIONS.
BOXELL
LONG TERM (SATURDAY THROUGH WEDNESDAY)...
LATEST ROUND OF MEDIUM RANGE MODEL OUTPUT OFFERS A FEW NEW TWISTS
ON THE FORECAST. OVERALL...STILL EXPECTING AN INCREASINGLY
AMPLIFIED PATTERN WITH A DEEP TROUGH OVER THE WESTERN CONUS AND
STRONG RIDGING OVER THE EASTERN CONUS. THE CHALLENGES FOR THIS
FORECAST IS THE EXPECTED BEHAVIOR OF THE WESTERN TROUGH. THERE IS
DISAGREEMENT WITH WHETHER OR NOT THIS TROUGH WILL BECOME CUTOFF
AND LINGER TO OUR WEST (PER THE GEFS)...REMAIN AN OPEN TROUGH AND
SLOWLY TRANSLATE EASTWARD (GEM/UKMET/00Z ECMWF). GIVEN THE FIVE
WAVE PROGS IT/S REALLY DIFFICULT TO FAVOR ONE SOLUTION OVER THE
OTHER AT THIS POINT. HAVE GONE WITH A CONSENSUS OF THE MODELS FOR
THE TIME BEING UNTIL A FAVORED SOLUTION IS IDENTIFIED.
FROM A SENSIBLE WEATHER PERSPECTIVE...CONTINUED WARM WITH ISOLATED
TO WIDELY SCATTERED SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED
OVER THE WEEKEND. AT THIS POINT...BETTER COVERAGE (RELATIVELY
SPEAKING) LOOKS TO BE ON SATURDAY AFTERNOON. SHOULD SEE A QUIETER
PERIOD SUNDAY NIGHT AND MONDAY...WITH GRADUALLY INCREASING POPS
FROM WEST TO EAST TUE/WED. WELL ABOVE AVERAGE TEMPERATURES WILL
CONTINUE INTO THE FIRST PART OF NEXT WEEK.
GAGAN
&&
.AVIATION...
ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP LATE TONIGHT AND CONTINUE INTO THURSDAY
MORNING. DID INCLUDE A TEMPO GROUP FOR THUNDERSTORMS AND MVFR
VISIBILITIES TO COVER THIS. MAINLY DRY CONDITIONS AND VFR FLIGHT
CATEGORIES ARE EXPECTED FROM THURSDAY AFTERNOON INTO THURSDAY
EVENING. WINDS WILL REMAIN OUT OF THE SOUTH...BECOMING GUSTY
THURSDAY AFTERNOON.
SCHAUMANN
&&
.CLIMATE...
SPRINGFIELD (KSGF)
DAY DATE TEMP YEAR
THR 15TH 79 1983
FRI 16TH 84 1945
JOPLIN (KJLN)
DAY DATE TEMP YEAR
THR 15TH 80 1983
FRI 16TH 78 1995
ROLLA-VICHY (KVIH)
DAY DATE TEMP YEAR
THR 15TH 75 1995
FRI 16TH 78 1982
WEST PLAINS (KUNO)
DAY DATE TEMP YEAR
THR 15TH 78 1977
FRI 16TH 82 1982
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BILLINGS MT
1021 AM MDT THU MAR 15 2012
.SHORT TERM...VALID FOR TDY AND FRI...
LOW- AND MID-LEVEL WARM AIR ADVECTION WILL OCCUR TODAY WHILE THERE
ARE SOME HEIGHT RISES ALOFT. ONLY MINOR CHANGES APPEAR IN ORDER TO
THE CURRENT FORECAST...WHICH ADVERTISES RECORD OR NEAR RECORD HIGH
TEMPERATURES IN MANY AREAS...AND A RED FLAG WARNING ACROSS MOST OF
SOUTH CENTRAL MT BELOW 5000 FT BEGINNING AT 18 UTC. THERE IS A BIT
OF UNCERTAINTY AS TO HOW DEEPLY WE WILL MIX THIS AFTERNOON...WHICH
WILL HAVE AN IMPACT ON WINDS AND TEMPERATURES. THE 12 UTC NAM ONLY
MIXES SOUTH CENTRAL MT OUT TO AROUND 700 HPA BECAUSE THE ADVECTION
OF WARM AIR INTO THE MID LEVELS CAPS THE BOUNDARY LAYER A BIT. THE
RECENT RUC RUNS...ON THE OTHER HAND...SIMULATE MIXING TO ABOUT 600
HPA AT BILLINGS. THE LATTER SOLUTION IS NOT UNREASONABLE GIVEN THE
TRENDS OVER THE PAST FEW DAYS...SO WE WILL NEED TO BE AWARE OF THE
POTENTIAL FOR TEMPERATURES TO BE A BIT WARMER THAN FORECAST. WINDS
IN THE MIXED LAYER PEAK AT 30 TO 35 KT...SO WE SHOULD HAVE SOME 30
MPH OR BETTER GUSTS THIS AFTERNOON IN SOUTH CENTRAL MT. SCHULTZ
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
THE EXTENDED PERIOD BEGINS SATURDAY WITH SHORTWAVE ENERGY MOVING
INTO THE REGION FROM THE SOUTHWEST. AS IT DOES...IT INTERACTS
WITH A SURFACE WARM FRONT LIFTING NORTHWARD TO BRING A CHANCE OF
PRECIP TO NORTHERN AND WESTERN PORTIONS OF THE CWA. ALTHOUGH
THERE IS NOT A LOT OF LOW LEVEL MOISTURE TO WORK WITH...DAYTIME
TEMPERATURES WILL BE UNSEASONABLY WARM WITH FAIRLY STEEP LAPSE
RATES...THUS CAPE VALUES OF A FEW HUNDRED J/KG WILL BE SUPPORTIVE
OF SOME WEAK CONVECTION DURING THE AFTERNOON/EVENING
HOURS...ESPECIALLY ACROSS THE WEST.
STRONGER SHORTWAVE ENERGY SUPPORTING A SURFACE COLD FRONT MOVES
INTO THE REGION DURING THE DAY SUNDAY. THE MAIN SURGE OF COLD AIR
ADVECTION DOES NOT LOOK LIKE IT WILL OCCUR UNTIL LATE IN THE DAY
ACROSS THE WEST...AND OVERNIGHT ACROSS THE EAST...BUT
AGAIN...UNSEASONABLY WARM DAYTIME TEMPERATURES IN AN INCREASINGLY
UNSTABLE ATMOSPHERE SHOULD GENERATE A COUPLE HUNDRED J/KG OF CAPE
ACROSS CENTRAL PORTIONS. THIS WILL SET THE STAGE FOR AT LEAST
SOME WEAK CONVECTION AHEAD OF THE FRONT...ESPECIALLY WHEN COUPLED
WITH JET ENERGY THAT IS EXPECTED TO BE CROSSING THE REGION.
BY LATE SUNDAY NIGHT INTO MONDAY...THE REGION WILL BE ON
THE COLD SIDE OF THE FRONT WITH HIGH TEMPERATURES MONDAY NOW EXPECTED
TO BE IN THE 40S AND 50S...SO FRONTOGENESIS INTERACTING WITH
SHORTWAVE ENERGY IN BROAD CYCLONIC FLOW ACROSS THE REGION SHOULD
BE ENOUGH TO PRODUCE WIDELY SCATTERED RAIN AND SNOW
SHOWERS...ESPECIALLY OVER THE HIGHER TERRAIN. THIS PATTERN IS
EXPECTED TO CONTINUE THROUGH TUESDAY...WITH THE COLD AIR ALOFT
INCREASING INSTABILITY. AS SUCH...KEPT BROADBRUSHED LOW POPS
ACROSS THE AREA.
MODELS SOLUTIONS DIVERGE FAIRLY SUBSTANTIALLY WEDNESDAY INTO
THURSDAY. THE GFS BRINGS ANOTHER COLD FRONT INTO THE REGION
WEDNESDAY INTO THURSDAY WITH PRECIP ACROSS THE CENTRAL AND
WEST...WHILE THE ECMWF BUILDS A RIDGE WEDNESDAY...AND DOES NOT
BRING THE FRONT INTO THE REGION UNTIL LATE THURSDAY. DUE TO THE
BIG DIFFERENCES...OPTED NOT TO MAKE ANY MAJOR CHANGES TO THE
WEDNESDAY/THURSDAY FORECAST. STC
&&
.AVIATION...
MAINLY VFR CONDITIONS WILL PREVAIL ACROSS THE AREA TODAY.
SOUTHWEST WINDS GUSTING TO MORE THAN 35 KTS ARE EXPECTED FROM
LATE THIS MORNING THROUGH THIS EVENING FROM KLVM TO BIG TIMBER
NORTH TO HARLOWTON...WITH SOUTHWEST WINDS GUSTING TO NEAR 30 KTS
AS FAR EAST AS ROUNDUP AND KBIL DURING THE AFTERNOON. WIDELY
SCATTERED MOUNTAIN RAIN AND SNOW SHOWERS WILL PRODUCE SOME
MOUNTAIN TOP OBSCURATIONS THROUGH THE DAY. BT
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 069 044/069 037/066 042/062 039/052 034/055 035/059
0/N 01/N 22/W 34/W 43/W 22/W 22/W
LVM 065 043/065 032/060 039/054 036/047 031/050 032/052
1/N 12/W 25/W 55/W 54/W 22/W 22/W
HDN 072 040/073 037/070 039/070 034/056 029/057 031/061
0/N 01/N 12/W 12/W 33/W 22/W 22/W
MLS 073 043/076 040/071 041/070 040/055 031/055 032/058
0/B 00/N 12/W 11/B 22/W 22/W 22/W
4BQ 072 041/075 039/072 042/071 037/055 032/056 032/058
0/B 00/N 11/B 11/N 22/W 22/W 22/W
BHK 071 040/074 039/068 041/071 036/055 031/052 031/056
0/B 00/N 12/W 11/B 22/W 22/W 22/W
SHR 068 041/070 036/068 038/064 035/049 028/052 029/055
0/B 01/N 11/B 12/W 33/W 33/W 22/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...FIRE WEATHER WATCH IN EFFECT FROM FRIDAY MORNING THROUGH
FRIDAY EVENING FOR ZONES 117-123-130>133.
RED FLAG WARNING IN EFFECT UNTIL 6 AM MDT FRIDAY BELOW 5000
FEET FOR ZONE 123.
RED FLAG WARNING IN EFFECT UNTIL 9 PM MDT FRIDAY BELOW 5000
FEET FOR ZONES 124>129.
WY...FIRE WEATHER WATCH IN EFFECT FROM FRIDAY MORNING THROUGH
FRIDAY EVENING FOR ZONE 274.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
345 PM CDT THU MAR 15 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY. MAIN FOCUS IS ON POTENTIAL
FOR FOG/STRATUS TONIGHT AND FRIDAY MORNING. A FAIRLY LARGE AREA OF
STRATUS ENCOMPASSED THE SOUTHEAST THIRD OF OUR CWA THIS MORNING AND
THE LOW CLOUDS HAVE BEEN SLOW TO ERODE EARLY THIS AFTERNOON. YORK
VSBY DROPPED TO A QUARTER MILE OR LESS FOR THE SECOND DAY IN A ROW
AND THE LOW VSBY LINGERED TO AROUND 15Z. MOISTURE AXIS AROUND
MIDDAY WAS LOCATED FROM KOLU TO KHSI TO KHLC WITH DPS ALONG AND
SOUTH OF THIS LINE IN THE 50S. MODELS INDICATE MOISTURE AXIS WILL
EXPAND FARTHER NORTH AND WEST TONIGHT AS WINDS TRANSITION SOUTHERLY
AND REMAIN LIGHT. EXPECT STRATUS TO REDEVELOP ACROSS A LARGER
AREA...AND ENCOMPASS A GOOD PORTION OF OUR CWA. FOG/REDUCED VSBYS
HAVE BEEN A FAIRLY COMMON THEME IN THIS REGIME AND PLAN TO GO WITH
PERSISTENCE IN THIS PATTERN. POTENTIAL EXISTS FOR MORE WIDESPREAD
VSBY RESTRICTIONS FRIDAY MORNING BASED ON RUC13 VSBYS PROGS AND
MODEL NUMERICAL GUIDANCE. MODELS DO INDICATE A LITTLE MORE IN THE
WAY OF MIXING OVER THE STRATUS...AND CONTEMPLATED ADDING IN SOME
DRIZZLE MENTION...HOWEVER CONFIDENCE IN DRIZZLE IS NOT HIGH ENOUGH
ATTM. IN HIGHER MOISTURE TONIGHT...GENERALLY LOOKING AT MILDER LOWS
RANGING FM NEAR 40 ON THE WESTERN EDGE OF STRATUS...TO LOW/MID 50S
IN THE SOUTHEAST CWA WHERE DPS ARE HIGHER.
LOW CLOUDS ARE EXPECTED TO ERODE AROUND MID DAY ON FRIDAY AND
SOUTHERLY WINDS WILL BE ON THE INCREASE DURING THE AFTERNOON. IN
BETTER MIXING CONDITIONS...TEMPS SHOULD REACH THE UPPER 70S TO THE
LOWER 80S FOR HIGHS.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY.
BEGINNING THE LONG TERM...MUCH OF THE CONUS REMAINS UNDER THE
INFLUENCE OF AN UPPER LEVEL RIDGE...WHILE AN UPPER LEVEL TROUGH
BEGINS TO PUSH EAST JUST OFF THE WEST COAST. THE UPPER LEVEL TROUGH
CONTINUES TO DEEPEN THROUGH THE WEEKEND...PUSHING THE TROUGH AXIS
ACROSS SOUTHERN CALIFORNIA BY SUNDAY. A SURFACE LOW PRESSURE SYSTEM
WILL BEGIN TO DEVELOP ACROSS THE NORTHERN ROCKIES AND MONTANA BY
SUNDAY. THIS SYSTEM WILL HELP INCREASE A PRESSURE GRADIENT ACROSS
THE CENTRAL PLAINS...AND THUS INCREASING SOUTH WINDS ACROSS THE
FORECAST AREA TO NEAR WIND ADVISORY CRITERIA.
AHEAD OF THE TROUGH...MOISTURE IS EXPECTED TO SURGE NORTHWARD FROM
THE GULF OF MEXICO. WHILE THE EC KEEPS MOISTURE WELL TO THE SOUTH
ON SUNDAY...THE GFS BRINGS THE MOISTURE MUCH FARTHER NORTH MAINLY
ACROSS FAR EASTERN NEBRASKA AND IOWA. BOTH THE GFS AND THE EC
CONTINUE TO SURGE MOISTURE NORTHWARD ON MONDAY...INCLUDING ACROSS
PORTIONS OF CENTRAL AND EASTERN NEBRASKA AND KANSAS. BOTH MODELS
ALSO HINT AT THE POSSIBILITY FOR THUNDERSTORMS AND POTENTIALLY
SEVERE THUNDERSTORMS...AS MU CAPES APPROACH 500 TO 1500 J/KG.
THE UPPER LEVEL SYSTEM PUSHES A COLD FRONT THROUGH THE REGION
TUESDAY AFTERNOON DECREASING HIGH TEMPERATURES BY ABOUT 10 DEGREES
THROUGH THE REMAINDER OF THE PERIOD. HOWEVER...BOTH MODELS CONTINUE
TO PUSH ANY MOISTURE FARTHER EAST ACROSS IOWA THROUGH WEDNESDAY.
BY WEDNESDAY MORNING...THE TROUGH AXIS CONTINUES TO DEEPEN FINALLY
CLOSING OFF THE UPPER LEVEL LOW ACROSS TEXAS. AT THE SURFACE...THE
EC IS BEGINNING TO LOOK MORE LIKE THE GFS WITH A SURFACE LOW
PRESSURE SYSTEM SURGING NORTH FROM THE GULF OF MEXICO ACROSS EASTERN
TEXAS. THIS LOW LOOKS TO SPIN NORTH ACROSS THE OKLAHOMA TEXAS
PANHANDLE WRAPPING AROUND YET ANOTHER ROUND OF PRECIPITATION ACROSS
KANSAS AND SOUTHERN NEBRASKA BY WEDNESDAY NIGHT INTO THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 1209 PM CDT THU MAR 15 2012/
AVIATION...18Z TAF. LOW CLOUDS THIS AFTN SOUTH OF THE TERMINAL
ARE EXPECTED TO REMAIN TO THE SOUTH...ALTHOUGH KGRI MAY SEE SOME
SCATTERED VFR CLOUDS. TONIGHT HOWEVER...LOW CLOUDS LOOK TO ADVECT
TO KGRI OR KGRI MAY BE ON PERIPHERY OF THE LOW CLOUDS. IN
INCREASING MOISTURE/LIGHT WINDS FOG DEVELOPMENT IS LOOKING
PROBABLE AND INTRODUCED FOG AND IFR CIGS. CANNOT COMPLETELY RULE
OUT A FEW HOURS OF LIFR CONDITIONS. CLOUDS SHLD SCATTER FRIDAY MID
MORNING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...CMF
LONG TERM...SALTZMAN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1209 PM CDT THU MAR 15 2012
.AVIATION...18Z TAF. LOW CLOUDS THIS AFTN SOUTH OF THE TERMINAL
ARE EXPECTED TO REMAIN TO THE SOUTH...ALTHOUGH KGRI MAY SEE SOME
SCATTERED VFR CLOUDS. TONIGHT HOWEVER...LOW CLOUDS LOOK TO ADVECT
TO KGRI OR KGRI MAY BE ON PERIPHERY OF THE LOW CLOUDS. IN
INCREASING MOISTURE/LIGHT WINDS FOG DEVELOPMENT IS LOOKING
PROBABLE AND INTRODUCED FOG AND IFR CIGS. CANNOT COMPLETELY RULE
OUT A FEW HOURS OF LIFR CONDITIONS. CLOUDS SHLD SCATTER FRIDAY MID
MORNING.
&&
PREV DISCUSSION... /ISSUED 526 AM CDT THU MAR 15 2012/
SHORT TERM...THROUGH SATURDAY NIGHT. PRIMARY FORECAST CONCERNS
ARE STRATUS AND FOG TRENDS...TEMPERATURES...AND WHETHER ANY
THUNDERSTORM CHANCES ARE NECESSARY DURING THE NEXT 72 HOURS. IN
SHORT...LEFT FORECAST FAIRLY SIMILAR TO PREVIOUS ONE...WITH NO
OFFICIAL PRECIPITATION MENTION AND A CONTINUATION OF MUCH-ABOVE
NORMAL TEMPERATURES.
09Z OBJECTIVE SURFACE ANALYSIS AND AUTOMATED OBS REVEAL A WEAK
SURFACE PRESSURE GRADIENT ACROSS THE CWA...WITH MOST PLACES
REPORTING VARIABLE TO LIGHT EASTERLY BREEZES. HOWEVER...A SHARP
TEMPERATURE/DEWPOINT GRADIENT IS VERY EVIDENT ALONG AN AXIS FROM
SOUTHWEST KANSAS TO FAR SOUTHEAST NEBRASKA...JUST BARELY SKIRTING
THE EDGES OF THE CWA AT THIS HOUR. THIS DIVIDING LINE IS ESSENTIALLY
A WEAK WARM FRONT...EXTENDING NORTHEAST FROM A WEAK LOW IN
SOUTHWEST KANSAS. FOR EXAMPLE...DEWPOINTS RANGE FROM ONLY 39 AT
HEBRON TO 59 AT CONCORDIA...ONLY TWO COUNTIES APART. AS HAS BEEN
THE CASE FOR SEVERAL NIGHTS NOW...TEMPS ACROSS MUCH OF THE CWA
HAVE SNUCK BELOW PREVIOUSLY FORECAST LOWS...WITH MOST PLACES IN
THE 40S...BUT TYPICAL COLD SITES SUCH AS ORD ALL THE WAY INTO THE
LOW 30S. TURNING TO 11-3.9 MICRON SATELLITE IMAGERY...A SWATH OF
LOW STRATUS HAS BEEN BLOSSOMING ACROSS NORTHERN KS INTO SOUTHEAST
NEB OVER THE PAST FEW HOURS...AS GENERALLY CAPTURED BY THE 900MB
RH FIELDS FROM THE 06Z NAM. DESPITE OBJECTIVE RUC ANALYSIS
INDICATING THAT AT LEAST 1000 J/KG MUCAPE HAS LIFTED INTO THE
SOUTHERN CWA...LACK OF FORCING AND CAPPING HAS PRECLUDED ANY
SHOWER/THUNDERSTORM DEVELOPMENT IN OR NEAR THE CWA. WATER VAPOR
IMAGERY AND SHORT TERM MODEL DATA INDICATES A PERSISTENT WEST-
SOUTHWEST FLOW ALOFT...WITH NO MAJOR SHORTWAVES IN THE FLOW EXCEPT
FOR ONE WELL OFF TO THE NORTHWEST ENTERING BRITISH COLUMBIA.
STARTING OFF WITH THE VERY SHORT TERM...MAIN CHALLENGE IS EXTENT
OF STRATUS DEVELOPMENT THIS MORNING...AND WHETHER ANY IMPACTFUL
FOG WILL JOIN THE FRAY AS WELL. FOLLOWED NAM 950-900MB RH FIELDS
FAIRLY CLOSELY FOR SKY COVER THIS MORNING...WITH STRATUS RAPIDLY
EXPANDING NORTHEAST AND ENCOMPASSING MUCH OF THE SOUTHEAST 1/3 TO
1/2 OF THE CWA BY SUNRISE. AS FOR FOG...PREVIOUS FORECAST ALREADY
HAD PATCHY WORDING...AND ACTUALLY EXPANDED THIS TO COVER A BIT
LARGER AREA...AS HRRR HAS INSISTED ON REDUCED VISIBILITIES ACROSS
MUCH OF THE SAME AREAS AS THE EXPANDING STRATUS. JUST WITHIN PAST
HOUR...BELOIT HAS NOW DROPPED TO 1/2 MILE VSBY. OBVIOUSLY TEMP
TRENDS TODAY WILL BE HIGHLY DEPENDENT ON STRATUS TRENDS...WITH NAM
SOUNDING INDICATING THAT SOUTHEAST AREAS COULD POTENTIALLY HOLD
ONTO STRATUS THROUGH AT LEAST MUCH OF THE MORNING HOURS BEFORE
MIXING OUT COMMENCES. CERTAINLY CONFIDENCE IS LOW IN THE HOURLY
TRENDS...BUT PER MET/MAV GUIDANCE CONSENSUS...NUDGED DOWN HIGHS A
FEW DEGREES FROM PREVIOUS FORECAST MOST AREAS...WITH NEARLY THE
ENTIRE CWA IN A FAIRLY UNIFORM 76-79 RANGE. AS FOR CONVECTIVE
CHANCES...MODELS HAVE BACKED OFF YET AGAIN ON SUGGESTION FROM 24
HOURS AGO OF POSSIBLE CONVECTION THIS AFTERNOON/EVENING IN THE
EASTERN CWA...AND DESPITE PRESENCE OF 1000-2000 J/KG MLCAPE
BUILDING INTO EASTERN AREAS THIS AFTERNOON...LACK OF FORCING AND A
DECENT CAPPING INVERSION SHOULD KEEP STORMS AT BAY AND THUS LEFT
DRY. A POTENTIALLY BETTER RISK FOR ISOLATED/SCATTERED CONVECTION
WILL RESIDE A FEW COUNTIES EAST OF THE CWA WITHIN NORTHEAST KS AND
FAR SOUTHEAST NEB PER THE 00Z 4KM WRF-NMM. BREEZES TODAY WILL
REMAIN FAIRLY LIGHT WITH A BROAD SURFACE TROUGH AXIS DRAPED
THROUGH FROM NORTH-SOUTH...SEPARATING A NORTHERLY COMPONENT IN THE
WEST FROM A SOUTHERLY ONE IN THE WEST. WHILE DEWPOINTS ACROSS MUCH
OF THE SOUTHEAST 2/3 OF THE CWA WILL BE ON THE INCREASE
TODAY...THE WEST WILL LIKELY REMAIN RATHER DRY AND THUS CARRY AN
ELEVATED FIRE THREAT TO SOME EXTENT. SEE FIRE WEATHER DISCUSSION
BELOW.
TONIGHT...KEPT IT DRY WITH FORCING REMAINING NEGLIGIBLE. WITH
BREEZES REMAINING LIGHT OVERNIGHT...AND PLENTY OF LOW LEVEL
MOISTURE AROUND...INTRODUCED ANOTHER ROUND OF PATCHY FOG WORDING
MAINLY ACROSS THE SOUTHEAST 2/3 OF THE CWA. WITH VARIOUS
MODELS/GUIDANCE SUCH AS MET/MAV AND ALSO SREF VISIBILITY
PROBABILITIES PICKING UP ON A FOG SIGNAL...WOULD NOT BE SURPRISED
TO SEE AT LEAST A FEW HOURS OF LOCALLY DENSE DEVELOPMENT...BUT
WILL START WITH GENERIC PATCHY FOR NOW. LEFT LOW TEMPS TONIGHT
SIMILAR TO PREVIOUS FORECAST RANGING FROM LOW 40S FAR WEST TO LOW
50S EAST...BUT WOULD NOT BE SURPRISED TO SEE A FEW WESTERN AREAS
AGAIN SETTLE INTO THE 30S IF THE AIR REMAINS DRY ENOUGH.
FRIDAY...THE FIRST POTENTIAL ISSUE WILL THE EXTENT OF ANY MORNING
STRATUS/FOG...ALTHOUGH A SLOWLY STRENGTHENING HIGH PLAINS LEE
TROUGH WILL INDUCE A BIT STRONGER SOUTHERLY BREEZE...WHICH SHOULD
HELP TO MIX OUT ANY FOG BY MID TO LATE MORNING IF IT DOES IN FACT
MATERIALIZE. INSTABILITY WILL AGAIN CLIMB ACROSS EASTERN ZONES
DURING THE AFTERNOON...BUT FORECAST SOUNDINGS AND PLAN VIEW PROGS
SHOW A HEALTHY CAP TO NEAR-SURFACE BASED CONVECTION AND THUS LEFT
OUT MENTION OF STORMS DURING THE DAY AND ALSO INTO THE
NIGHT...ALTHOUGH THE NIGHT PERIOD WILL NEED WATCHED AS LOW LEVEL
JET RAMPS UP. IN FACT...06Z NAM HINTS AT POSSIBLE ISOLATED STORM
DEVELOPMENT JUST EAST OF THE CWA AT SOME POINT FRIDAY NIGHT...BUT
CONFIDENCE IS LOW GIVEN RECENT TRENDS OF CONVECTIVE SIGNALS NOT
PANNING OUT. CHANGED FRIDAY HIGH TEMPS LITTLE FROM BEFORE...WITH
NEAR 80 IN NEB ZONES AND LOW-MID 80S IN KS.
SATURDAY/SATURDAY NIGHT...THE FLOW ALOFT STARTS TURNING MORE
SOUTH-SOUTHWESTERLY IN RESPONSE TO A DEEP...HIGH AMPLITUDE TROUGH
FINALLY COMING ONSHORE ACROSS THE WESTERN CONUS. ALTHOUGH FORECAST
SOUNDINGS CONTINUE TO SHOW AIRMASS CAPPED TO CONVECTIVE
POTENTIAL...THERE ARE HINTS IN MODELS SUCH AS THE ECMWF/GFS THAT
STRATUS AND POSSIBLE DRIZZLE COULD AFFECT EASTERN ZONES DURING
THIS TIME FRAME. LEFT DRY FOR NOW HOWEVER. THE MAIN STORY SATURDAY
WILL BE INCREASING SOUTHERLY BREEZES...WITH SUSTAINED SPEEDS
LIKELY INTO THE 20-25 MPH RANGE ACROSS MUCH OF THE CWA WITH HIGHER
GUSTS. AS FOR TEMPS...SURE ENOUGH...ANOTHER DAY OF UPPER
70S-LOW 80S LOOKS IN STORE.
IN CLOSING...ALTHOUGH RISK OF CONVECTION IS CERTAINLY NOT NIL
ACROSS THE CWA DURING THE NEXT FEW DAYS...DEGREE OF CAPPING AND
LACK OF FORCING PRECLUDES FORMAL MENTION OF EVEN SLIGHT CHANCES
FOR NOW...WITH LOCATIONS GENERALLY 100-200 MILES EAST-SOUTHEAST OF
THE CWA MORE FAVORED FOR AT LEAST LIMITED STORM COVERAGE DURING
THIS TIME FRAME.
LONG TERM...SUNDAY THROUGH WEDNESDAY. THIS WILL CONTINUE TO BE AN
UNSEASONABLY WARM PERIOD. IN ADDITION...THUNDERSTORMS WILL ALSO BE
POSSIBLE AS A VERY DEEP UPPER LEVEL TROUGH DIGS ACROSS THE WESTERN
CONUS.
THIS PATTERN WILL ALLOW MOISTURE RICH AIR TO FLOW NORTH THROUGH THE
PLAINS IN ADVANCE OF THE DEEPENING WESTERN CONUS TROUGH. THE
COMBINATION OF RICH SFC MOISTURE AND STRONG UPPER LEVEL WINDS AND
SHEAR WILL LIKELY RESULT IN SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE GREAT PLAINS.
THE MOST LIKELY TIME FRAME FOR STRONG TO SEVERE THUNDERSTORMS OVER
CENTRAL NEBRASKA AND CENTRAL KANSAS WILL BE MONDAY AND TUESDAY. A
FAIRLY STRONG CAP ON SUNDAY WILL BE DIFFICULT TO OVERCOME GIVEN THAT
THE BETTER FORCING ASSOCIATED WITH THE UPPER SYSTEM WILL STILL BE
WELL OFF TO THE WEST ON SUNDAY. THE SYSTEM SHOULD THEN EITHER BE
EAST OF OUR CWA OR BECOME A CUT OFF LOW TO OUR SOUTH BY
WEDNESDAY...NEITHER OF THESE SCENARIOS WOULD BE VERY FAVORABLE FOR
THUNDERSTORMS. CONSEQUENTLY...IT APPEARS THAT MONDAY AND TUESDAY
WILL BE THE MOST FAVORABLE DAYS FOR THUNDERSTORMS INCLUDING THE
POTENTIAL FOR SOME SEVERE THUNDERSTORMS DEPENDING ON HOW FAR
EAST/WEST THE DRY LINE SETS UP. THE LATEST MODEL RUNS CONTINUE TO
SEEM TO BE TOO FAST WITH THIS SYSTEM. THE 00Z GFS AND ECMWF ARE BOTH
FASTER/FURTHER EAST WITH THE UPPER TROUGH THAN THE 00Z ENSEMBLE
MEAN. IN ADDITION...THIS KIND OF PATTERN WITH A LARGE BLOCKING RIDGE
ACROSS THE EASTERN CONUS WILL TYPICALLY SLOW SYSTEM PROGRESSION DOWN
MORE THAN THE FORECAST MODELS ACCOUNT FOR. THEREFORE...EXPECT A
POTENTIALLY STORMY START TO NEXT WEEK...ESPECIALLY IN THE MONDAY
AND/OR TUESDAY TIME FRAME.
FIRE WEATHER...ALTHOUGH WIND SPEEDS TODAY SHOULD FALL WELL SHORT
OF OFFICIAL RED FLAG WARNING CRITERIA OF 20 MPH SUSTAINED/25 MPH
GUST...LATEST 06Z NAM SUGGESTS THAT DEWPOINTS ACROSS GENERALLY THE
NORTHWEST 1/3 OF THE CWA WILL CHECK IN A BIT LOWER THAN PREVIOUSLY
EXPECTED...AND QUITE A BIT LOWER THAN VALUES ACROSS THE SOUTHEAST
1/2 OF THE CWA WHERE DEWPOINTS SHOULD STEADILY INCREASE. THE NET
RESULT IS AFTERNOON RELATIVE HUMIDITY VALUES TUMBLING TO AROUND 20
PERCENT ACROSS A HANDFUL OF FAR WESTERN/NORTHWEST COUNTIES THIS
AFTERNOON...WHILE MUCH HIGHER RH VALUES 40-50 PERCENT RESIDE
ACROSS MUCH OF THE EASTERN CWA. DESPITE THE FAIRLY LIGHT WINDS...THE
GRASSLAND FIRE DANGER STATEMENT...RFDGID...CALCULATED EXTREME FIRE
DANGER CATEGORY FOR DAWSON AND GOSPER COUNTIES FOR THIS
AFTERNOON...WITH SEVERAL BORDERING COUNTIES IN THE VERY HIGH
CATEGORY. LOOKING AHEAD A FEW DAYS...INCREASED DEWPOINTS AND THUS
RH VALUES SHOULD INVADE EVEN WESTERN COUNTIES ON FRIDAY AND
SATURDAY...THUS KEEPING RH ABOVE 20 PERCENT. HOWEVER...AN
EFFECTIVE NORTH-SOUTH DRYLINE WILL SET UP JUST WEST OF THE
CWA...MEANING THAT WESTERN COUNTIES COULD LIE VERY CLOSE TO A
SHARP MOISTURE GRADIENT ON THOSE DAYS AND FLIRT WITH DROPPING
BELOW 20 PERCENT RH. GIVEN THAT SOUTH WINDS WILL ALSO BE ON THE
INCREASE...WILL NEED TO CLOSELY WATCH WESTERN FRINGE OF CWA FOR
FIRE WEATHER ISSUES...WHILE THE MAJORITY OF THE CWA SHOULD BE IN
BETTER SHAPE THAN LATELY WITH THE ARRIVAL OF HIGHER DAYTIME DEWPOINTS
IN THE 40S AND 50S.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
554 AM CDT THU MAR 15 2012
.AVIATION...12Z KGRI TAF. A LOW STRATUS DECK IS QUICKLY EXPANDING
ACROSS KANSAS AND WILL SLIDE INTO FAR SOUTHERN NEBRASKA EARLY THIS
MORNING. FORECAST MODEL GUIDANCE KEEPS THESE LOW CEILINGS TO THE
SOUTH OF KGRI...BUT IT WILL BE A CLOSE CALL. A SCATTERED LOW DECK
AT KGRI IS CERTAINLY POSSIBLE BY MID MORNING AND EVEN MVFR OR IFR
CEILINGS CAN NOT BE RULED OUT. HOWEVER...IT IS SLIGHTLY MORE
LIKELY THAT THE LOW CEILINGS WILL STAY SOUTH OF KGRI AND
THEREFORE...WILL BE KEEPING THE VFR CEILINGS IN THE TAF FOR NOW.
ANY LOW STRATUS CLOUDS SHOULD BURN OFF BY EARLY AFTERNOON MAKING
FOR A MOSTLY SUNNY AFTERNOON. LOW STRATUS CLOUDS WILL AGAIN FORM
NEAR KGRI TONIGHT. WILL JUST CALL FOR A SCATTERED DECK FOR
NOW...BUT IFR CEILINGS ARE AT LEAST SOMEWHAT POSSIBLE AGAIN
TONIGHT. THE WIND WILL BE LIGHT AND VARIABLE THROUGHOUT THE
PERIOD.
&&
.PREV DISCUSSION... /ISSUED 526 AM CDT THU MAR 15 2012/
SHORT TERM...THROUGH SATURDAY NIGHT. PRIMARY FORECAST CONCERNS
ARE STRATUS AND FOG TRENDS...TEMPERATURES...AND WHETHER ANY
THUNDERSTORM CHANCES ARE NECESSARY DURING THE NEXT 72 HOURS. IN
SHORT...LEFT FORECAST FAIRLY SIMILAR TO PREVIOUS ONE...WITH NO
OFFICIAL PRECIPITATION MENTION AND A CONTINUATION OF MUCH-ABOVE
NORMAL TEMPERATURES.
09Z OBJECTIVE SURFACE ANALYSIS AND AUTOMATED OBS REVEAL A WEAK
SURFACE PRESSURE GRADIENT ACROSS THE CWA...WITH MOST PLACES
REPORTING VARIABLE TO LIGHT EASTERLY BREEZES. HOWEVER...A SHARP
TEMPERATURE/DEWPOINT GRADIENT IS VERY EVIDENT ALONG AN AXIS FROM
SOUTHWEST KANSAS TO FAR SOUTHEAST NEBRASKA...JUST BARELY SKIRTING
THE EDGES OF THE CWA AT THIS HOUR. THIS DIVIDING LINE IS ESSENTIALLY
A WEAK WARM FRONT...EXTENDING NORTHEAST FROM A WEAK LOW IN
SOUTHWEST KANSAS. FOR EXAMPLE...DEWPOINTS RANGE FROM ONLY 39 AT
HEBRON TO 59 AT CONCORDIA...ONLY TWO COUNTIES APART. AS HAS BEEN
THE CASE FOR SEVERAL NIGHTS NOW...TEMPS ACROSS MUCH OF THE CWA
HAVE SNUCK BELOW PREVIOUSLY FORECAST LOWS...WITH MOST PLACES IN
THE 40S...BUT TYPICAL COLD SITES SUCH AS ORD ALL THE WAY INTO THE
LOW 30S. TURNING TO 11-3.9 MICRON SATELLITE IMAGERY...A SWATH OF
LOW STRATUS HAS BEEN BLOSSOMING ACROSS NORTHERN KS INTO SOUTHEAST
NEB OVER THE PAST FEW HOURS...AS GENERALLY CAPTURED BY THE 900MB
RH FIELDS FROM THE 06Z NAM. DESPITE OBJECTIVE RUC ANALYSIS
INDICATING THAT AT LEAST 1000 J/KG MUCAPE HAS LIFTED INTO THE
SOUTHERN CWA...LACK OF FORCING AND CAPPING HAS PRECLUDED ANY
SHOWER/THUNDERSTORM DEVELOPMENT IN OR NEAR THE CWA. WATER VAPOR
IMAGERY AND SHORT TERM MODEL DATA INDICATES A PERSISTENT WEST-
SOUTHWEST FLOW ALOFT...WITH NO MAJOR SHORTWAVES IN THE FLOW EXCEPT
FOR ONE WELL OFF TO THE NORTHWEST ENTERING BRITISH COLUMBIA.
STARTING OFF WITH THE VERY SHORT TERM...MAIN CHALLENGE IS EXTENT
OF STRATUS DEVELOPMENT THIS MORNING...AND WHETHER ANY IMPACTFUL
FOG WILL JOIN THE FRAY AS WELL. FOLLOWED NAM 950-900MB RH FIELDS
FAIRLY CLOSELY FOR SKY COVER THIS MORNING...WITH STRATUS RAPIDLY
EXPANDING NORTHEAST AND ENCOMPASSING MUCH OF THE SOUTHEAST 1/3 TO
1/2 OF THE CWA BY SUNRISE. AS FOR FOG...PREVIOUS FORECAST ALREADY
HAD PATCHY WORDING...AND ACTUALLY EXPANDED THIS TO COVER A BIT
LARGER AREA...AS HRRR HAS INSISTED ON REDUCED VISIBILITIES ACROSS
MUCH OF THE SAME AREAS AS THE EXPANDING STRATUS. JUST WITHIN PAST
HOUR...BELOIT HAS NOW DROPPED TO 1/2 MILE VSBY. OBVIOUSLY TEMP
TRENDS TODAY WILL BE HIGHLY DEPENDENT ON STRATUS TRENDS...WITH NAM
SOUNDING INDICATING THAT SOUTHEAST AREAS COULD POTENTIALLY HOLD
ONTO STRATUS THROUGH AT LEAST MUCH OF THE MORNING HOURS BEFORE
MIXING OUT COMMENCES. CERTAINLY CONFIDENCE IS LOW IN THE HOURLY
TRENDS...BUT PER MET/MAV GUIDANCE CONSENSUS...NUDGED DOWN HIGHS A
FEW DEGREES FROM PREVIOUS FORECAST MOST AREAS...WITH NEARLY THE
ENTIRE CWA IN A FAIRLY UNIFORM 76-79 RANGE. AS FOR CONVECTIVE
CHANCES...MODELS HAVE BACKED OFF YET AGAIN ON SUGGESTION FROM 24
HOURS AGO OF POSSIBLE CONVECTION THIS AFTERNOON/EVENING IN THE
EASTERN CWA...AND DESPITE PRESENCE OF 1000-2000 J/KG MLCAPE
BUILDING INTO EASTERN AREAS THIS AFTERNOON...LACK OF FORCING AND A
DECENT CAPPING INVERSION SHOULD KEEP STORMS AT BAY AND THUS LEFT
DRY. A POTENTIALLY BETTER RISK FOR ISOLATED/SCATTERED CONVECTION
WILL RESIDE A FEW COUNTIES EAST OF THE CWA WITHIN NORTHEAST KS AND
FAR SOUTHEAST NEB PER THE 00Z 4KM WRF-NMM. BREEZES TODAY WILL
REMAIN FAIRLY LIGHT WITH A BROAD SURFACE TROUGH AXIS DRAPED
THROUGH FROM NORTH-SOUTH...SEPARATING A NORTHERLY COMPONENT IN THE
WEST FROM A SOUTHERLY ONE IN THE WEST. WHILE DEWPOINTS ACROSS MUCH
OF THE SOUTHEAST 2/3 OF THE CWA WILL BE ON THE INCREASE
TODAY...THE WEST WILL LIKELY REMAIN RATHER DRY AND THUS CARRY AN
ELEVATED FIRE THREAT TO SOME EXTENT. SEE FIRE WEATHER DISCUSSION
BELOW.
TONIGHT...KEPT IT DRY WITH FORCING REMAINING NEGLIGIBLE. WITH
BREEZES REMAINING LIGHT OVERNIGHT...AND PLENTY OF LOW LEVEL
MOISTURE AROUND...INTRODUCED ANOTHER ROUND OF PATCHY FOG WORDING
MAINLY ACROSS THE SOUTHEAST 2/3 OF THE CWA. WITH VARIOUS
MODELS/GUIDANCE SUCH AS MET/MAV AND ALSO SREF VISIBILITY
PROBABILITIES PICKING UP ON A FOG SIGNAL...WOULD NOT BE SURPRISED
TO SEE AT LEAST A FEW HOURS OF LOCALLY DENSE DEVELOPMENT...BUT
WILL START WITH GENERIC PATCHY FOR NOW. LEFT LOW TEMPS TONIGHT
SIMILAR TO PREVIOUS FORECAST RANGING FROM LOW 40S FAR WEST TO LOW
50S EAST...BUT WOULD NOT BE SURPRISED TO SEE A FEW WESTERN AREAS
AGAIN SETTLE INTO THE 30S IF THE AIR REMAINS DRY ENOUGH.
FRIDAY...THE FIRST POTENTIAL ISSUE WILL THE EXTENT OF ANY MORNING
STRATUS/FOG...ALTHOUGH A SLOWLY STRENGTHENING HIGH PLAINS LEE
TROUGH WILL INDUCE A BIT STRONGER SOUTHERLY BREEZE...WHICH SHOULD
HELP TO MIX OUT ANY FOG BY MID TO LATE MORNING IF IT DOES IN FACT
MATERIALIZE. INSTABILITY WILL AGAIN CLIMB ACROSS EASTERN ZONES
DURING THE AFTERNOON...BUT FORECAST SOUNDINGS AND PLAN VIEW PROGS
SHOW A HEALTHY CAP TO NEAR-SURFACE BASED CONVECTION AND THUS LEFT
OUT MENTION OF STORMS DURING THE DAY AND ALSO INTO THE
NIGHT...ALTHOUGH THE NIGHT PERIOD WILL NEED WATCHED AS LOW LEVEL
JET RAMPS UP. IN FACT...06Z NAM HINTS AT POSSIBLE ISOLATED STORM
DEVELOPMENT JUST EAST OF THE CWA AT SOME POINT FRIDAY NIGHT...BUT
CONFIDENCE IS LOW GIVEN RECENT TRENDS OF CONVECTIVE SIGNALS NOT
PANNING OUT. CHANGED FRIDAY HIGH TEMPS LITTLE FROM BEFORE...WITH
NEAR 80 IN NEB ZONES AND LOW-MID 80S IN KS.
SATURDAY/SATURDAY NIGHT...THE FLOW ALOFT STARTS TURNING MORE
SOUTH-SOUTHWESTERLY IN RESPONSE TO A DEEP...HIGH AMPLITUDE TROUGH
FINALLY COMING ONSHORE ACROSS THE WESTERN CONUS. ALTHOUGH FORECAST
SOUNDINGS CONTINUE TO SHOW AIRMASS CAPPED TO CONVECTIVE
POTENTIAL...THERE ARE HINTS IN MODELS SUCH AS THE ECMWF/GFS THAT
STRATUS AND POSSIBLE DRIZZLE COULD AFFECT EASTERN ZONES DURING
THIS TIME FRAME. LEFT DRY FOR NOW HOWEVER. THE MAIN STORY SATURDAY
WILL BE INCREASING SOUTHERLY BREEZES...WITH SUSTAINED SPEEDS
LIKELY INTO THE 20-25 MPH RANGE ACROSS MUCH OF THE CWA WITH HIGHER
GUSTS. AS FOR TEMPS...SURE ENOUGH...ANOTHER DAY OF UPPER
70S-LOW 80S LOOKS IN STORE.
IN CLOSING...ALTHOUGH RISK OF CONVECTION IS CERTAINLY NOT NIL
ACROSS THE CWA DURING THE NEXT FEW DAYS...DEGREE OF CAPPING AND
LACK OF FORCING PRECLUDES FORMAL MENTION OF EVEN SLIGHT CHANCES
FOR NOW...WITH LOCATIONS GENERALLY 100-200 MILES EAST-SOUTHEAST OF
THE CWA MORE FAVORED FOR AT LEAST LIMITED STORM COVERAGE DURING
THIS TIME FRAME.
LONG TERM...SUNDAY THROUGH WEDNESDAY. THIS WILL CONTINUE TO BE AN
UNSEASONABLY WARM PERIOD. IN ADDITION...THUNDERSTORMS WILL ALSO BE
POSSIBLE AS A VERY DEEP UPPER LEVEL TROUGH DIGS ACROSS THE WESTERN
CONUS.
THIS PATTERN WILL ALLOW MOISTURE RICH AIR TO FLOW NORTH THROUGH THE
PLAINS IN ADVANCE OF THE DEEPENING WESTERN CONUS TROUGH. THE
COMBINATION OF RICH SFC MOISTURE AND STRONG UPPER LEVEL WINDS AND
SHEAR WILL LIKELY RESULT IN SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE GREAT PLAINS.
THE MOST LIKELY TIME FRAME FOR STRONG TO SEVERE THUNDERSTORMS OVER
CENTRAL NEBRASKA AND CENTRAL KANSAS WILL BE MONDAY AND TUESDAY. A
FAIRLY STRONG CAP ON SUNDAY WILL BE DIFFICULT TO OVERCOME GIVEN THAT
THE BETTER FORCING ASSOCIATED WITH THE UPPER SYSTEM WILL STILL BE
WELL OFF TO THE WEST ON SUNDAY. THE SYSTEM SHOULD THEN EITHER BE
EAST OF OUR CWA OR BECOME A CUT OFF LOW TO OUR SOUTH BY
WEDNESDAY...NEITHER OF THESE SCENARIOS WOULD BE VERY FAVORABLE FOR
THUNDERSTORMS. CONSEQUENTLY...IT APPEARS THAT MONDAY AND TUESDAY
WILL BE THE MOST FAVORABLE DAYS FOR THUNDERSTORMS INCLUDING THE
POTENTIAL FOR SOME SEVERE THUNDERSTORMS DEPENDING ON HOW FAR
EAST/WEST THE DRY LINE SETS UP. THE LATEST MODEL RUNS CONTINUE TO
SEEM TO BE TOO FAST WITH THIS SYSTEM. THE 00Z GFS AND ECMWF ARE BOTH
FASTER/FURTHER EAST WITH THE UPPER TROUGH THAN THE 00Z ENSEMBLE
MEAN. IN ADDITION...THIS KIND OF PATTERN WITH A LARGE BLOCKING RIDGE
ACROSS THE EASTERN CONUS WILL TYPICALLY SLOW SYSTEM PROGRESSION DOWN
MORE THAN THE FORECAST MODELS ACCOUNT FOR. THEREFORE...EXPECT A
POTENTIALLY STORMY START TO NEXT WEEK...ESPECIALLY IN THE MONDAY
AND/OR TUESDAY TIME FRAME.
FIRE WEATHER...ALTHOUGH WIND SPEEDS TODAY SHOULD FALL WELL SHORT
OF OFFICIAL RED FLAG WARNING CRITERIA OF 20 MPH SUSTAINED/25 MPH
GUST...LATEST 06Z NAM SUGGESTS THAT DEWPOINTS ACROSS GENERALLY THE
NORTHWEST 1/3 OF THE CWA WILL CHECK IN A BIT LOWER THAN PREVIOUSLY
EXPECTED...AND QUITE A BIT LOWER THAN VALUES ACROSS THE SOUTHEAST
1/2 OF THE CWA WHERE DEWPOINTS SHOULD STEADILY INCREASE. THE NET
RESULT IS AFTERNOON RELATIVE HUMIDITY VALUES TUMBLING TO AROUND 20
PERCENT ACROSS A HANDFUL OF FAR WESTERN/NORTHWEST COUNTIES THIS
AFTERNOON...WHILE MUCH HIGHER RH VALUES 40-50 PERCENT RESIDE
ACROSS MUCH OF THE EASTERN CWA. DESPITE THE FAIRLY LIGHT WINDS...THE
GRASSLAND FIRE DANGER STATEMENT...RFDGID...CALCULATED EXTREME FIRE
DANGER CATEGORY FOR DAWSON AND GOSPER COUNTIES FOR THIS
AFTERNOON...WITH SEVERAL BORDERING COUNTIES IN THE VERY HIGH
CATEGORY. LOOKING AHEAD A FEW DAYS...INCREASED DEWPOINTS AND THUS
RH VALUES SHOULD INVADE EVEN WESTERN COUNTIES ON FRIDAY AND
SATURDAY...THUS KEEPING RH ABOVE 20 PERCENT. HOWEVER...AN
EFFECTIVE NORTH-SOUTH DRYLINE WILL SET UP JUST WEST OF THE
CWA...MEANING THAT WESTERN COUNTIES COULD LIE VERY CLOSE TO A
SHARP MOISTURE GRADIENT ON THOSE DAYS AND FLIRT WITH DROPPING
BELOW 20 PERCENT RH. GIVEN THAT SOUTH WINDS WILL ALSO BE ON THE
INCREASE...WILL NEED TO CLOSELY WATCH WESTERN FRINGE OF CWA FOR
FIRE WEATHER ISSUES...WHILE THE MAJORITY OF THE CWA SHOULD BE IN
BETTER SHAPE THAN LATELY WITH THE ARRIVAL OF HIGHER DAYTIME DEWPOINTS
IN THE 40S AND 50S.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
526 AM CDT THU MAR 15 2012
.SHORT TERM...THROUGH SATURDAY NIGHT. PRIMARY FORECAST CONCERNS
ARE STRATUS AND FOG TRENDS...TEMPERATURES...AND WHETHER ANY
THUNDERSTORM CHANCES ARE NECESSARY DURING THE NEXT 72 HOURS. IN
SHORT...LEFT FORECAST FAIRLY SIMILAR TO PREVIOUS ONE...WITH NO
OFFICIAL PRECIPITATION MENTION AND A CONTINUATION OF MUCH-ABOVE
NORMAL TEMPERATURES.
09Z OBJECTIVE SURFACE ANALYSIS AND AUTOMATED OBS REVEAL A WEAK
SURFACE PRESSURE GRADIENT ACROSS THE CWA...WITH MOST PLACES
REPORTING VARIABLE TO LIGHT EASTERLY BREEZES. HOWEVER...A SHARP
TEMPERATURE/DEWPOINT GRADIENT IS VERY EVIDENT ALONG AN AXIS FROM
SOUTHWEST KANSAS TO FAR SOUTHEAST NEBRASKA...JUST BARELY SKIRTING
THE EDGES OF THE CWA AT THIS HOUR. THIS DIVIDING LINE IS ESSENTIALLY
A WEAK WARM FRONT...EXTENDING NORTHEAST FROM A WEAK LOW IN
SOUTHWEST KANSAS. FOR EXAMPLE...DEWPOINTS RANGE FROM ONLY 39 AT
HEBRON TO 59 AT CONCORDIA...ONLY TWO COUNTIES APART. AS HAS BEEN
THE CASE FOR SEVERAL NIGHTS NOW...TEMPS ACROSS MUCH OF THE CWA
HAVE SNUCK BELOW PREVIOUSLY FORECASTED LOWS...WITH MOST PLACES IN
THE 40S...BUT TYPICAL COLD SITES SUCH AS ORD ALL THE WAY INTO THE
LOW 30S. TURNING TO 11-3.9 MICRON SATELLITE IMAGERY...A SWATH OF
LOW STRATUS HAS BEEN BLOSSOMING ACROSS NORTHERN KS INTO SOUTHEAST
NEB OVER THE PAST FEW HOURS...AS GENERALLY CAPTURED BY THE 900MB
RH FIELDS FROM THE 06Z NAM. DESPITE OBJECTIVE RUC ANALYSIS
INDICATING THAT AT LEAST 1000 J/KG MUCAPE HAS LIFTED INTO THE
SOUTHERN CWA...LACK OF FORCING AND CAPPING HAS PRECLUDED ANY
SHOWER/THUNDERSTORM DEVELOPMENT IN OR NEAR THE CWA. WATER VAPOR
IMAGERY AND SHORT TERM MODEL DATA INDICATES A PERSISTENT WEST-
SOUTHWEST FLOW ALOFT...WITH NO MAJOR SHORTWAVES IN THE FLOW EXCEPT
FOR ONE WELL OFF TO THE NORTHWEST ENTERING BRITISH COLUMBIA.
STARTING OFF WITH THE VERY SHORT TERM...MAIN CHALLENGE IS EXTENT
OF STRATUS DEVELOPMENT THIS MORNING...AND WHETHER ANY IMPACTFUL
FOG WILL JOIN THE FRAY AS WELL. FOLLOWED NAM 950-900MB RH FIELDS
FAIRLY CLOSELY FOR SKY COVER THIS MORNING...WITH STRATUS RAPIDLY
EXPANDING NORTHEAST AND ENCOMPASSING MUCH OF THE SOUTHEAST 1/3 TO
1/2 OF THE CWA BY SUNRISE. AS FOR FOG...PREVIOUS FORECAST ALREADY
HAD PATCHY WORDING...AND ACTUALLY EXPANDED THIS TO COVER A BIT
LARGER AREA...AS HRRR HAS INSISTED ON REDUCED VISIBILITIES ACROSS
MUCH OF THE SAME AREAS AS THE EXPANDING STRATUS. JUST WITHIN PAST
HOUR...BELOIT HAS NOW DROPPED TO 1/2 MILE VSBY. OBVIOUSLY TEMP
TRENDS TODAY WILL BE HIGHLY DEPENDENT ON STRATUS TRENDS...WITH NAM
SOUNDING INDICATING THAT SOUTHEAST AREAS COULD POTENTIALLY HOLD
ONTO STRATUS THROUGH AT LEAST MUCH OF THE MORNING HOURS BEFORE
MIXING OUT COMMENCES. CERTAINLY CONFIDENCE IS LOW IN THE HOURLY
TRENDS...BUT PER MET/MAV GUIDANCE CONSENSUS...NUDGED DOWN HIGHS A
FEW DEGREES FROM PREVIOUS FORECAST MOST AREAS...WITH NEARLY THE
ENTIRE CWA IN A FAIRLY UNIFORM 76-79 RANGE. AS FOR CONVECTIVE
CHANCES...MODELS HAVE BACKED OFF YET AGAIN ON SUGGESTION FROM 24
HOURS AGO OF POSSIBLE CONVECTION THIS AFTERNOON/EVENING IN THE
EASTERN CWA...AND DESPITE PRESENCE OF 1000-2000 J/KG MLCAPE
BUILDING INTO EASTERN AREAS THIS AFTERNOON...LACK OF FORCING AND A
DECENT CAPPING INVERSION SHOULD KEEP STORMS AT BAY AND THUS LEFT
DRY. A POTENTIALLY BETTER RISK FOR ISOLATED/SCATTERED CONVECTION
WILL RESIDE A FEW COUNTIES EAST OF THE CWA WITHIN NORTHEAST KS AND
FAR SOUTHEAST NEB PER THE 00Z 4KM WRF-NMM. BREEZES TODAY WILL
REMAIN FAIRLY LIGHT WITH A BROAD SURFACE TROUGH AXIS DRAPED
THROUGH FROM NORTH-SOUTH...SEPARATING A NORTHERLY COMPONENT IN THE
WEST FROM A SOUTHERLY ONE IN THE WEST. WHILE DEWPOINTS ACROSS MUCH
OF THE SOUTHEAST 2/3 OF THE CWA WILL BE ON THE INCREASE
TODAY...THE WEST WILL LIKELY REMAIN RATHER DRY AND THUS CARRY AN
ELEVATED FIRE THREAT TO SOME EXTENT. SEE FIRE WEATHER DISCUSSION
BELOW.
TONIGHT...KEPT IT DRY WITH FORCING REMAINING NEGLIGIBLE. WITH
BREEZES REMAINING LIGHT OVERNIGHT...AND PLENTY OF LOW LEVEL
MOISTURE AROUND...INTRODUCED ANOTHER ROUND OF PATCHY FOG WORDING
MAINLY ACROSS THE SOUTHEAST 2/3 OF THE CWA. WITH VARIOUS
MODELS/GUIDANCE SUCH AS MET/MAV AND ALSO SREF VISIBILITY
PROBABILITIES PICKING UP ON A FOG SIGNAL...WOULD NOT BE SURPRISED
TO SEE AT LEAST A FEW HOURS OF LOCALLY DENSE DEVELOPMENT...BUT
WILL START WITH GENERIC PATCHY FOR NOW. LEFT LOW TEMPS TONIGHT
SIMILAR TO PREVIOUS FORECAST RANGING FROM LOW 40S FAR WEST TO LOW
50S EAST...BUT WOULD NOT BE SURPRISED TO SEE A FEW WESTERN AREAS
AGAIN SETTLE INTO THE 30S IF THE AIR REMAINS DRY ENOUGH.
FRIDAY...THE FIRST POTENTIAL ISSUE WILL THE EXTENT OF ANY MORNING
STRATUS/FOG...ALTHOUGH A SLOWLY STRENGTHENING HIGH PLAINS LEE
TROUGH WILL INDUCE A BIT STRONGER SOUTHERLY BREEZE...WHICH SHOULD
HELP TO MIX OUT ANY FOG BY MID TO LATE MORNING IF IT DOES IN FACT
MATERIALIZE. INSTABILITY WILL AGAIN CLIMB ACROSS EASTERN ZONES
DURING THE AFTERNOON...BUT FORECAST SOUNDINGS AND PLAN VIEW PROGS
SHOW A HEALTHY CAP TO NEAR-SURFACE BASED CONVECTION AND THUS LEFT
OUT MENTION OF STORMS DURING THE DAY AND ALSO INTO THE
NIGHT...ALTHOUGH THE NIGHT PERIOD WILL NEED WATCHED AS LOW LEVEL
JET RAMPS UP. IN FACT...06Z NAM HINTS AT POSSIBLE ISOLATED STORM
DEVELOPMENT JUST EAST OF THE CWA AT SOME POINT FRIDAY NIGHT...BUT
CONFIDENCE IS LOW GIVEN RECENT TRENDS OF CONVECTIVE SIGNALS NOT
PANNING OUT. CHANGED FRIDAY HIGH TEMPS LITTLE FROM BEFORE...WITH
NEAR 80 IN NEB ZONES AND LOW-MID 80S IN KS.
SATURDAY/SATURDAY NIGHT...THE FLOW ALOFT STARTS TURNING MORE
SOUTH-SOUTHWESTERLY IN RESPONSE TO A DEEP...HIGH AMPLITUDE TROUGH
FINALLY COMING ONSHORE ACROSS THE WESTERN CONUS. ALTHOUGH FORECAST
SOUNDINGS CONTINUE TO SHOW AIRMASS CAPPED TO CONVECTIVE
POTENTIAL...THERE ARE HINTS IN MODELS SUCH AS THE ECMWF/GFS THAT
STRATUS AND POSSIBLE DRIZZLE COULD AFFECT EASTERN ZONES DURING
THIS TIME FRAME. LEFT DRY FOR NOW HOWEVER. THE MAIN STORY SATURDAY
WILL BE INCREASING SOUTHERLY BREEZES...WITH SUSTAINED SPEEDS
LIKELY INTO THE 20-25 MPH RANGE ACROSS MUCH OF THE CWA WITH HIGHER
GUSTS. AS FOR TEMPS...SURE ENOUGH...ANOTHER DAY OF UPPER
70S-LOW 80S LOOKS IN STORE.
IN CLOSING...ALTHOUGH RISK OF CONVECTION IS CERTAINLY NOT NIL
ACROSS THE CWA DURING THE NEXT FEW DAYS...DEGREE OF CAPPING AND
LACK OF FORCING PRECLUDES FORMAL MENTION OF EVEN SLIGHT CHANCES
FOR NOW...WITH LOCATIONS GENERALLY 100-200 MILES EAST-SOUTHEAST OF
THE CWA MORE FAVORED FOR AT LEAST LIMITED STORM COVERAGE DURING
THIS TIME FRAME.
.LONG TERM...SUNDAY THROUGH WEDNESDAY. THIS WILL CONTINUE TO BE AN
UNSEASONABLY WARM PERIOD. IN ADDITION...THUNDERSTORMS WILL ALSO BE
POSSIBLE AS A VERY DEEP UPPER LEVEL TROUGH DIGS ACROSS THE WESTERN
CONUS.
THIS PATTERN WILL ALLOW MOISTURE RICH AIR TO FLOW NORTH THROUGH THE
PLAINS IN ADVANCE OF THE DEEPENING WESTERN CONUS TROUGH. THE
COMBINATION OF RICH SFC MOISTURE AND STRONG UPPER LEVEL WINDS AND
SHEAR WILL LIKELY RESULT IN SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE GREAT PLAINS.
THE MOST LIKELY TIME FRAME FOR STRONG TO SEVERE THUNDERSTORMS OVER
CENTRAL NEBRASKA AND CENTRAL KANSAS WILL BE MONDAY AND TUESDAY. A
FAIRLY STRONG CAP ON SUNDAY WILL BE DIFFICULT TO OVERCOME GIVEN THAT
THE BETTER FORCING ASSOCIATED WITH THE UPPER SYSTEM WILL STILL BE
WELL OFF TO THE WEST ON SUNDAY. THE SYSTEM SHOULD THEN EITHER BE
EAST OF OUR CWA OR BECOME A CUT OFF LOW TO OUR SOUTH BY
WEDNESDAY...NEITHER OF THESE SCENARIOS WOULD BE VERY FAVORABLE FOR
THUNDERSTORMS. CONSEQUENTLY...IT APPEARS THAT MONDAY AND TUESDAY
WILL BE THE MOST FAVORABLE DAYS FOR THUNDERSTORMS INCLUDING THE
POTENTIAL FOR SOME SEVERE THUNDERSTORMS DEPENDING ON HOW FAR
EAST/WEST THE DRY LINE SETS UP. THE LATEST MODEL RUNS CONTINUE TO
SEEM TO BE TOO FAST WITH THIS SYSTEM. THE 00Z GFS AND ECMWF ARE BOTH
FASTER/FURTHER EAST WITH THE UPPER TROUGH THAN THE 00Z ENSEMBLE
MEAN. IN ADDITION...THIS KIND OF PATTERN WITH A LARGE BLOCKING RIDGE
ACROSS THE EASTERN CONUS WILL TYPICALLY SLOW SYSTEM PROGRESSION DOWN
MORE THAN THE FORECAST MODELS ACCOUNT FOR. THEREFORE...EXPECT A
POTENTIALLY STORMY START TO NEXT WEEK...ESPECIALLY IN THE MONDAY
AND/OR TUESDAY TIME FRAME.
&&
.FIRE WEATHER...ALTHOUGH WIND SPEEDS TODAY SHOULD FALL WELL SHORT
OF OFFICIAL RED FLAG WARNING CRITERIA OF 20 MPH SUSTAINED/25 MPH
GUST...LATEST 06Z NAM SUGGESTS THAT DEWPOINTS ACROSS GENERALLY THE
NORTHWEST 1/3 OF THE CWA WILL CHECK IN A BIT LOWER THAN PREVIOUSLY
EXPECTED...AND QUITE A BIT LOWER THAN VALUES ACROSS THE SOUTHEAST
1/2 OF THE CWA WHERE DEWPOINTS SHOULD STEADILY INCREASE. THE NET
RESULT IS AFTERNOON RELATIVE HUMIDITY VALUES TUMBLING TO AROUND 20
PERCENT ACROSS A HANDFUL OF FAR WESTERN/NORTHWEST COUNTIES THIS
AFTERNOON...WHILE MUCH HIGHER RH VALUES 40-50 PERCENT RESIDE
ACROSS MUCH OF THE EASTERN CWA. DESPITE THE FAIRLY LIGHT WINDS...THE
GRASSLAND FIRE DANGER STATEMENT...RFDGID...CALCULATED EXTREME FIRE
DANGER CATEGORY FOR DAWSON AND GOSPER COUNTIES FOR THIS
AFTERNOON...WITH SEVERAL BORDERING COUNTIES IN THE VERY HIGH
CATEGORY. LOOKING AHEAD A FEW DAYS...INCREASED DEWPOINTS AND THUS
RH VALUES SHOULD INVADE EVEN WESTERN COUNTIES ON FRIDAY AND
SATURDAY...THUS KEEPING RH ABOVE 20 PERCENT. HOWEVER...AN
EFFECTIVE NORTH-SOUTH DRYLINE WILL SET UP JUST WEST OF THE
CWA...MEANING THAT WESTERN COUNTIES COULD LIE VERY CLOSE TO A
SHARP MOISTURE GRADIENT ON THOSE DAYS AND FLIRT WITH DROPPING
BELOW 20 PERCENT RH. GIVEN THAT SOUTH WINDS WILL ALSO BE ON THE
INCREASE...WILL NEED TO CLOSELY WATCH WESTERN FRINGE OF CWA FOR
FIRE WEATHER ISSUES...WHILE THE MAJORITY OF THE CWA SHOULD BE IN
BETTER SHAPE THAN LATELY WITH THE ARRIVAL OF HIGHER DAYTIME DEWPOINTS
IN THE 40S AND 50S.
&&
.PREV DISCUSSION... /ISSUED 1244 AM CDT THU MAR 15 2012/
AVIATION...06Z KGRI TAF. A LOW STRATUS DECK IS SLIDING NORTH
THROUGH KANSAS EARLY THIS MORNING. THE BIG FORECAST CHALLENGE WILL
BE DETERMINING HOW FAR NORTH THESE CLOUDS WILL MAKE IT AS THE
NORTHERN EXTENT OF THE CLOUDS COULD BE VERY CLOSE TO KGRI. FOR
NOW...WILL CONTINUE TO KEEP THE LOW STRATUS DECK SOUTH OF THE KGRI
AREA ALLOWING FOR A CONTINUATION OF THE VFR CONDITIONS. THE WIND
WILL BE VERY LIGHT AND VARIABLE THROUGHOUT THE PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...PFANNKUCH
LONG TERM...WESELY
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1016 PM EDT FRI MAR 16 2012
.SYNOPSIS...
SEVERAL WEAK UPPER LEVEL DISTURBANCES WILL BRING A CHANCE OF
THUNDERSTORMS THROUGH THE WEEKEND. HIGH PRESSURE WILL BUILD INTO
THE REGION THROUGH THE FIRST PART OF NEXT WEEK WITH TEMPERATURES
REMAINING WELL ABOVE.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
MOST OF SHOWERS OVER KENTUCKY ASSOCIATED WITH WEAK LOW PRESSURE
HAVE DISSIPATED WITH LOSS OF DAYTIME HEATING. WILL HANG ON TO SOME
LOW POPS ACROSS THE SOUTH THROUGH THE OVERNIGHT HOURS THOUGH JUST
IN CASE REDEVELOPMENT OCCURS AS SUGGESTED BY THE HRRR MODEL.
EXPECT OVERNIGHT LOWS GENERALLY IN THE MID TO UPPER 50S.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
THE MID/UPPER LEVEL RIDGE WILL TRY TO BUILD UP ACROSS THE AREA
THROUGH THE WEEKEND...BUT IT WILL BE TEMPERED BY SEVERAL WEAK
SHORT WAVES RIDING OVER THE RIDGE. WITH A WARM AND SEASONABLY
MOIST AIRMASS IN PLACE...THIS SHOULD BE ENOUGH TO TRIGGER AT LEAST
SCATTERED THUNDERSTORM ACTIVITY ON AND OFF SATURDAY INTO SUNDAY.
RIGHT NOW IT LOOKS LIKE THE BEST FORCING WILL MOVE ACROSS THE AREA
ON SUNDAY BUT MODELS HAVE A DIFFICULT TIME WITH THE
TIMING/STRENGTH OF THESE SHORT WAVES. WILL THEREFORE KEEP POPS IN
THE CHANCE CATEGORY THROUGH MUCH OF THE WEEKEND. DEEP LAYER SHEAR
REMAINS RELATIVELY WEAK...ALTHOUGH IT DOES BEGIN TO INCREASE A BIT
FROM THE SOUTHWEST THROUGH THE DAY ON SUNDAY. THEREFORE WOULD
THINK SEVERE THREAT WILL REMAIN RELATIVELY LOW THROUGH THE
WEEKEND. WITH FAIRLY LIGHT FLOW...LOCALLY HEAVY RAIN SHOULD BE THE
MAIN ISSUE. TEMPERATURES WILL REMAIN DEPENDENT ON AMOUNT OF CLOUD
COVER AND PCPN. WILL KEEP HIGHS MAINLY IN THE UPPER 70S...BUT IF WE
END UP WITH MORE SUN...THESE MAY BE A LITTLE LOW.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
RIDGING WILL AMPLIFY ACROSS THE REGION IN RESPONSE TO A DEEP TROUGH
MOVING SLOWLY EAST ACROSS THE ROCKIES....BRINGING INCREASING HEIGHTS
AND TEMPERATURES ALOFT FOR MONDAY AND TUESDAY. THIS WILL RESULT IN
THE WARMEST TEMPERATURES OF THE WEEK...POSSIBLY APPROACHING RECORD
VALUES. ONE INHIBITING FACTOR FOR TEMPERATURES RISING HIGHER THAN
FORECAST WILL BE THE POTENTIAL AMOUNTS OF MID AND UPPER LEVEL CLOUD
COVER...WHICH THE MODELS ARE NOT IN AGREEMENT ON AT THIS TIME.
THE TROUGH TO OUR WEST WILL CLOSE OFF INTO AN UPPER LOW AS IT SLOWLY
MOVES EASTWARD ACROSS THE PLAINS DURING THE MID WEEK. MODELS
CONTINUE TO BRING THE LOW FINALLY ACROSS THE OHIO VALLEY LATE NEXT
WEEK. THERE CONTINUE TO BE TIMING DIFFERENCES OF WHEN THIS WILL
OCCUR. HOWEVER...AS IT DOES SO...CHANCES FOR PRECIPITATION WILL
INCREASE. HAVE SPLIT THE DIFFERENCE BETWEEN THE GFS AND ECMWF IN
BRINGING BEST POPS TO THE AREA AT 00Z FRIDAY. TEMPERATURES WILL
RETURN TO MORE SEASONABLE VALUES ONCE THE LOW ARRIVES IN OUR AREA.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL REMAIN TO THE EAST WITH A FEW MID LEVEL
DISTURBANCES INTERACTING WITH AN UNSTABLE AIRMASS TO PRODUCE
THUNDERSTORMS. CONDITIONS WILL BE VFR TO START BUT BR MAY CAUSE
MVFR VISIBILITIES TONIGHT. A FEW THUNDERSTORMS MAY OCCUR ON
SATURDAY AFTERNOON AS INSTABILITY INCREASES DUE TO DAYTIME HEATING
AND A SHORT WAVE ALOFT. WINDS WILL BE OUT OF THE SOUTH TO
SOUTHEAST AT UNDER 10 KNOTS.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...CONIGLIO/JGL
SHORT TERM...JGL
LONG TERM...LATTO
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
918 AM EDT THU MAR 15 2012
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL SLIDE EAST ACROSS LAKE ERIE
TODAY. WEAK HIGH PRESSURE WILL BUILD SOUTHEAST OUT OF CANADA LATE
FRIDAY...THEN TO THE EAST COAST ON SATURDAY. A WEAK AREA OF LOW
PRESSURE WILL BRING ANOTHER SURGE OF MOISTURE TO THE AREA AGAIN
LATE SATURDAY INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BOTH HRRR AND RUC SHOW CURRENT WIDESPREAD CONVECTION SETTLING DOWN
INTO THE MIDDAY HOURS THEN STARTING TO REDEVELOP DURING THE MID TO
LATE AFTERNOON HOURS FOR MOSTLY THE WEST HALF OF THE AREA. THE
REDEVELOPMENT MAKES SENSE BASED ON WHERE MORE SUNSHINE IS EXPECTED
BUT NOT ENTIRELY SOLD ON THE FACT THAT ALL THE CURRENT CONVECTION
COMPLETELY GOES AWAY. WILL OPT TO LEAVE AT LEAST A SMALL CHANCE
GOING FOR ALL AREAS DURING MIDDAY THEN RAMP THE POPS BACK UP FOR
THE NEW ACTIVITY. LITTLE CHANGE TO HIGH TEMP FORECAST BUT WILL
ADJUST AND BLEND FOR CURRENT AND IMMINENT CONDITIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
SIMILAR AIRMASS IN PLACE TONIGHT WITH LINGERING THETA-E RIDGE
OVERHEAD. DIFFERENCE IS LESS IN THE WAY OF A LOW LEVEL JET AND WEAK
RIDGING BUILDING OVERHEAD. WILL THEREFORE EXPECT LESS THUNDERSTORM
ACTIVITY DESPITE LINGERING ELEVATED INSTABILITY IN PLACE.
WEAK HIGH PRESSURE WILL PUSH SOUTH OUT OF CANADA ON FRIDAY WITH
ANOTHER RETURN SURGE OF MOISTURE BY LATE SATURDAY INTO SUNDAY AS THE
RIDGE BUILDS TO THE EAST COAST. TEMPERATURES REMAIN WELL ABOVE
NORMAL THROUGH THE SHORT TERM IN THE UPPER 60S AND LOW TO EVEN MID
70S AT TIMES.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
IMPRESSIVE UPPER LEVEL RIDGE WILL RESIDE OVER THE EASTERN HALF OF
THE UNITED STATES THROUGH THE EXTENDED. THERE MAY END UP BEING
ENOUGH LOW LEVEL MOISTURE TO ALLOW FOR SOME AFTERNOON AND EVENING
THUNDERSTORMS. BEST CHANCES LOOK TO BE OVER THE HILLS AND ALONG ANY
LAKE BREEZE BOUNDARY THAT DEVELOPS.
TEMPERATURES WILL BE WELL ABOVE AVERAGE...LIKELY 25 TO 30 DEGREES
ABOVE AVERAGE. LOW TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE
NORMAL HIGHS FOR THIS TIME OF YEAR.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DECREASE IN
COVERAGE AND INTENSITY AS THEY DRIFT SLOWLY TO THE EAST. HAVE
STARTED SEVERAL TAF SITES ACROSS THE CENTRAL AND EAST WITH SOME
VICINITY SHOWERS AND THUNDERSTORMS. ANY MVFR OR BRIEF IFR WILL
OCCUR WITH THE THUNDERSTORMS. AWAY FROM THIS MORNINGS THUNDERSTORMS
EXPECT TO SEE A CONTINUATION OF VFR CONDITIONS. MOST LOCATIONS WILL
SEE SOME AFTERNOON CUMULUS. ADDITIONAL THUNDERSTORMS WILL DEVELOP
BY MID TO LATE AFTERNOON AND CONTINUE INTO THE EVENING. PLENTY OF
UNCERTAINTY ABOUT WHERE ANY BOUNDARIES FROM THIS MORNING
CONVECTION WILL BE BY AFTERNOON. THIS OUTFLOW BOUNDARY AND A
DISSIPATING FRONTAL BOUNDARY THAT WILL SAG TO NEAR LAKE ERIE
OVERNIGHT WILL BECOME THE FOCUS FOR AFTERNOON AND EVENING
THUNDERSTORMS.
OUTLOOK...NON VFR CONDITIONS POSSIBLE FRIDAY NIGHT THROUGH SUNDAY
IN ISOLATED TO SCATTERED THUNDERSTORMS.
&&
.MARINE...
A WEAK DISTURBANCE OVER LAKE SUPERIOR WILL DEVELOP ON THU AND MOVE N
OF LAKE ERIE ON FRI. SW FLOW AHEAD OF THE LOW WILL INCREASE BUT
REMAIN BELOW 20KT LATE THU AND INTO FRI. A WEAK BACKDOOR COLD FRONT
COULD SLIP JUST SOUTH OF THE LAKE FRI NT AND SATURDAY. THIS WEAK
SYSTEM WASHES OUT EARLY AS THE UPPER RIDGE RE-ESTABLISHES ITSELF
OVER THE REGION INTO NEXT WEEK. THE RIDGE WILL KEEP A PREDOMINANT SW
FLOW WITH PERIODS OF S/SE. NO HEADLINES EXPECTED THROUGH THE
FORECAST PERIOD AT THIS TIME.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...ADAMS/KEC
SHORT TERM...KEC
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS NORMAN OK
1056 PM CDT FRI MAR 16 2012
.AVIATION...
CLOUD DEBRIS FROM CONVECTION ACROSS TX PANHANDLE...IS MOVING
QUICKLY TO THE NORTHEAST LATE THIS EVENING. A FEW LIGHT
SHOWERS WILL BE POSSIBLE ACROSS SOUTHERN OKLAHOMA OVERNIGHT
WITH MAYBE A BETTER CHANCE OF CONVECTION ACROSS SOUTH CENTRAL
OKLAHOMA PER SEVERAL HRRR RUNS. LOW CLOUDS WITH MAINLY MFVR
CEILINGS SHOULD DEVELOP DURING THE OVERNIGHT HOURS THEN GRADUALLY
IMPROVE BY LATE MORNING.
&&
.PREV DISCUSSION... /ISSUED 945 PM CDT FRI MAR 16 2012/
UPDATE...
SHOWER ACTIVITY CONTINUES TO DWINDLE TONIGHT AS INVERSION
STRENGTHENS ACROSS THE FA. WILL KEEP CHANCE POPS IN OVERNIGHT
MAINLY ACROSS SOUTHERN HALF OF OKLAHOMA AND WESTERN NORTH
TEXAS...WHERE LIGHT SHOWERS MAY DEVELOP IN RESPONSE TO WEAK LIFT
ASSOCIATED WITH EXITING WAVE. BUMPED MIN TEMPS UP A DEGREE OR TWO
MAINLY ACROSS CENTRAL AND SOUTHERN OKLAHOMA WITH A SIMILAR AIRMASS
IN PLACE AS LAST TWO NIGHTS. DEWPOINTS WERE INCREASED NORTHWEST AS
DRYLINE HAS MIXED RAPIDLY WESTWARD THIS EVENING. ASIDE FROM THESE
MINOR CHANGES...FORECAST IS LARGELY ON TRACK THROUGH TOMORROW
MORNING.
PREV DISCUSSION... /ISSUED 709 PM CDT FRI MAR 16 2012/
AVIATION...
STORM INTENSITY ACROSS THE TEXAS PANHANDLE IS ON THE DECREASE
EARLY THIS EVENING AND DRYLINE IS RETREATING TO THE WEST.
STILL MAY SEE A FEW STORMS ENTER WESTERN OKLAHOMA...BUT OVERALL
COVERAGE SHOULD BE ISOLATED TO WIDELY SCATTERED. LOW CLOUD COVER
MAY DECREASE A LITTLE DURING THE EARLY EVENING ACROSS CENTRAL
OKLAHOMA BUT MVFR TO IFR CEILINGS ARE EXPECTED OVERNIGHT.
PREV DISCUSSION... /ISSUED 434 PM CDT FRI MAR 16 2012/
DISCUSSION...
SOUTHERLY LOW LEVEL FLOW CONTINUES ACROSS THE REGION THIS
AFTERNOON...WITH DEWPOINTS IN THE LOW 60S PERSISTING FOR MOST
LOCATIONS. CLEARING SKIES OVER WEST/SW OK COMBINED WITH AN
APPROACHING SHORTWAVE TROUGH MOVING OVER THE CAPROCK EARLY THIS
EVENING SHOULD RESULT IN INCREASED THUNDERSTORM CHANCES FROM W/SW
OK INTO NORTH TEXAS...THEN SPREADING EASTWARD PERHAPS OVER THE
I-35 CORRIDOR LATE TONIGHT. A CU FIELD HAS DEVELOPED OVER THE
EASTERN PANHANDLE ALONG THE SFC TROUGH/DRYLINE THIS AFTERNOON.
SEVERE STORMS WITH A THREAT OF HAIL AND DAMAGING WINDS WILL BE
POSSIBLE THROUGH THE EARLY EVENING HOURS. EXPECT THE SEVERE
THREAT TO WANE AS INSTABILITY DECREASES AFTER SUNSET.
SOUTHERLY LOW LEVEL FLOW WILL CONTINUE THROUGH TOMORROW MORNING
AS PACIFIC TROUGH MOVES ONSHORE NEAR CA AND ANOTHER LLJ DEVELOPS.
THIS WILL KEEP LOW LEVEL MOISTURE TRANSPORT IN PLACE. RAIN CHANCES
WILL INCREASE DRAMATICALLY BEGINNING LATE SUNDAY NIGHT INITIALLY
ACROSS WESTERN/SOUTHWESTERN OK...AS A SHORTWAVE TROUGH AHEAD OF
THE NEGATIVELY TILTED UPPER TROUGH MOVES OVERHEAD. DEEP WIDESPREAD
LIFT WILL THEN IMPACT THE ENTIRE CWA BY EARLY MONDAY MORNING AS A
MERIDIONAL UPPER JET EXTENDS FROM WEST TX THROUGH THE CENTRAL
PLAINS. MODERATE TO HEAVY RAINFALL LOOKS TO BE ONE OF THE MAIN
THREATS AT THIS TIME CONSIDERING THE STRONG UNIDIRECTIONAL
SOUTHERLY FLOW STILL ANTICIPATED. THIS WILL BE WATCHED CLOSELY
OVER THE NEXT SEVERAL DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 63 76 59 75 / 30 20 10 20
HOBART OK 59 76 57 74 / 30 10 20 20
WICHITA FALLS TX 61 78 60 78 / 30 20 20 30
GAGE OK 57 79 58 76 / 20 10 10 20
PONCA CITY OK 62 79 62 77 / 20 20 10 20
DURANT OK 64 75 61 76 / 40 20 10 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
525 PM PDT FRI MAR 16 2012
.SYNOPSIS...A LOW PRESSURE SYSTEM RAPIDLY DEVELOPING OFF THE NORTHERN
CALIFORNIA COAST WILL MOVE INTO SOUTHWEST OREGON EARLY THIS EVENING
THEN WEAKEN AS IT MOVES NORTHEAST ACROSS THE AREA TONIGHT. IT
WILL LIKELY BRING BREEZY TO WINDY CONDITIONS INLAND TONIGHT. THE
COOL WEATHER PATTERN CONTINUES THIS WEEKEND...THEN WARMER AND WET
SYSTEMS ARRIVE EARLY NEXT WEEK. EXPECT LOW SNOW LEVELS OVER THE
WEEKEND. SNOW AMOUNTS SHOULD BE LIGHT WHEN SNOW LEVELS ARE NEAR
LOWEST POINT.
&&
.UPDATE...UPDATED AVIATION DISCUSSION BELOW...
.SHORT TERM...SATELLITE IMAGERY SHOWS THE LOW PRESSURE SYSTEM OFF
THE SW OREGON COAST NEAR 42N/128W RAPIDLY DEVELOPING THIS AFTERNOON.
THE NAM AND GFS MODELS ARE IN MUCH BETTER AGREEMENT ON THE TRACK AND
EVOLUTION OFF THIS SYSTEM THAN PREVIOUS DAYS. BOTH MODELS BRING THE
LOW INTO THE SW OREGON COAST NEAR BROOKINGS THIS EVENING. SOME SLIGHT
DIFFERENCES IN THE TRACK OF THE LOW WITH THE NAM TAKING A MORE
NORTHERLY TRACK UP THE WILLAMETTE VALLEY AND GFS A LITTLE MORE
NORTHEASTERLY DURING THE OVERNIGHT HOURS. THE PRESSURE RISE/FALL
COUPLET IS NOT NEARLY AS STRONG AS YESTERDAY MODEL RUNS...BUT STILL
INDICATE SOME STRONG WIND POTENTIAL TONIGHT WITH SOME RAPID PRESSURE
RISES BEHIND THE FRONT. LOOKS LIKE THE BEST AREA TO GET SOME STRONG
WINDS TONIGHT WILL BE SOUTHERN AND CENTRAL WILLAMETTE VALLEY AND
ADJACENT FOOTHILLS AND COASTAL RANGE AREA. HAVE OPTED TO ISSUE WIND
ADVISORY FOR THE SOUTHERN AND CENTRAL WILLAMETTE VALLEY TONIGHT FOR
WINDS GUSTS AROUND 45 MPH. WITH RECENT RAINS AND SATURATED
SOILS...THESE WINDS COULD EASILY BREAK LIMBS OFF TREES AND PUSH DOWN
SOME WEAKENED TREES. THE NORTHERN WILLAMETTE VALLEY WILL ALSO GET
SOME BREEZY WINDS BEFORE SUNRISE SATURDAY MORNING...BUT NOT AS STRONG
AS FURTHER SOUTH.
ANOTHER CONCERN IS SOME SNOW POTENTIAL DURING THE OVERNIGHT HOURS IN
THE NORTH COASTAL AREA...COAST RANGE/WILLAPA HILLS AND EASTERN
COLUMBIA RIVER GORGE. THE COOL AND DRY AIR IN THE OFFSHORE FLOW AHEAD
OF THE LOW MAY BRING LOW SNOW LEVELS TO THE EASTERN GORGE NEAR HOOD
RIVER TONIGHT AS THE WRAP AROUND PRECIPITATION COOL THE AIR COLUMN TO
BRING THE SNOW LEVEL TO NEAR THE THE SURFACE. THERE ISNT ALOT OF COLD
AIR IN THE COLUMBIA BASIN AND THE GROUND SURFACE IS FAIRLY WARM...SO
ONLY EXPECTING AROUND AN INCH IN THE EASTERN GORGE. OUT ON THE NORTH
COAST...THERE IS SOME POTENTIAL FOR SOME SNOW FOR ABOUT 4 OR 5 HOURS
DURING THE OVERNIGHT HOURS. MODEL BUFR SOUNDINGS INDICATE THE COLUMN
IS COLD ENOUGH FOR SNOW AS THE COLD AIR WRAPS AROUND THE LOW IN THE
DEFORMATION BAND. NAM MODELS SHOWS SOME HIGH PRECIPITATION RATES FOR
THE NORTHERN COASTAL REGION FROM TILLAMOOK NORTHWARD AS WELL AS THE
COAST RANGE/WILLAPA HILLS DURING THIS PERIOD. WE HAVE ISSUED A SNOW
ADVISORY FOR THE COAST RANGE AND WILLAPA HILLS. CONFIDENCE ISNT
QUITE AS HIGH FOR THE COASTAL STRIP...SO WILL MONITOR CLOSELY
TONIGHT AS SITUATION EVOLVES...BUT THE POTENTIAL FOR SOME SNOW ALONG
THE COAST EXISTS.
LOW SNOW LEVELS RETURN SUNDAY AND SUNDAY NIGHT WITH A THREAT OF SNOW
SHOWERS GETTING CLOSE TO SEA LEVEL SUNDAY NIGHT. HOWEVER...MOISTURE
BECOMES QUITE LIMITED THEN AS THE SHOWERS WIND DOWN AFTER THE UPPER
TROUGH PASSAGE. TW
&&
.HYDRO...FLOOD WARNINGS CONTINUE FOR LOWER NEHALEM RIVER NEAR FOSS
AND PUDDING RIVER. LOWER NEHALEM RIVER IS SLOWLY RECEDING AND WILL
LIKELY FALL BELOW FLOOD STAGE LATE TONIGHT OR EARLY TOMORROW. SLOW
RESPONDING PUDDING RIVER EXPECTED TO RISE TO FLOOD STAGE TONIGHT AS
HIGH WATER SLOWLY WORKS THOUGH THIS RIVER SYSTEM.
&&
.LONG TERM...FOLLOWING A WEEKEND OF MAINLY LIGHT SHOWER
ACTIVITY...THE STORM TRACK IS FCST TO MOVE BACK NORTH OVER THE PAC
NW STARTING ON TUE. FLAT RIDGING WILL REMAIN OVER THE REGION ON MON
NIGHT...BUT A SYSTEM TO THE NORTH IS FCST TO SWING A WARM FRONT INTO
THE DISTRICT LATE MON INTO TUE MORNING. EXPECT SOME GUSTY COASTAL
WINDS AND RAPIDLY RISING SNOW LEVELS AS WINDS TURN SOUTHERLY. MODEL
SOLUTIONS DIVERGE FOLLOWING THE TUE SYSTEM. THE 12Z ECMWF BRINGS
ANOTHER STRONGER SYSTEM THROUGH ON WED INTO EARLY THU. IF THIS
VERIFIES...IT LOOKS LIKE MORE HEAVY RAIN AND STRONG COASTAL WINDS.
THE 12Z GFS DIGS THE BULK OF THE ENERGY FURTHER SOUTH OF US. THE
LAST FEW RUNS OF THE ECMWF HAVE BEEN CONSISTENT WITH THIS WED
FEATURE...SO LEANED TOWARDS THIS SOLUTION FOR THE LONG TERM FCST.
HEADING INTO THE END OF THE WEEK AND NEXT WEEKEND...THE MODELS TEND
TO DIG OUT A DEEP TROUGH OVER THE ENTIRE WEST COAST. IT IS LOOKING
MUCH LIKE THE PATTERN THAT WE WILL SEE THIS WEEKEND. JFP
&&
.AVIATION...VFR CONDITIONS CONTINUE INTO THIS EVENING AHEAD OF THE
APPROACHING STRONG LOW PRESSURE SYSTEM OFF THE S OR COAST. EXPECT
VFR CONDITIONS TO PREVAIL IN THE VALLEY THROUGH MUCH OF THE EVENING
ON THE WARM SIDE OF THE SYSTEM...WITH A LOWERING OF CEILINGS
CONTINUING. EXPECT WINDS TO PICK UP AFTER 06Z...WITH SOUTHERLY WINDS
GUSTS NEAR 30 TO 35 KTS AROUND KEUG...POSSIBLY SOME GUSTS TO 30 KT
NEAR KSLE. THERE IS ALSO THE POSSIBLY OF THUNDER IN THE SOUTH
VALLEY...POSSIBLY EXTENDING SLIGHTLY FURTHER NORTH...DURING THE MID
TO LATE EVENING...AS THE DRY SLOT ASSOCIATED WITH UPPER LEVEL LOW
SPREADS IN WITH ITS ASSOCIATED STRONG FORCING AND COOLING ALOFT.
EXPECT THE BEST CHANCE FOR MVFR IN THE VALLEY WITH THE PRECIPITATION
ON THE BACK SIDE OF THE LOW...WHICH IS EXPECTED AFTER 8-9Z. THEN A
RETURN TO VFR WITH MVFR IN SHOWERS ON SATURDAY. THE LOW LEVELS ARE
VERY UNSTABLE TOMORROW...BUT FORECAST SOUNDINGS INDICATE SHALLOW
MOISTURE...SO HAVE LEFT THE THUNDER MENTION OUT FOR NOW.
THE COASTAL TAF SITES WILL REMAIN ON THE COLDER SIDE OF THE SYSTEM.
EXPECT A CHANCE OF THUNDER AROUND KONP THIS EVENING...AS THE DRY
SLOT MOVES RIGHT OVER. THEN STRONGER GUSTY WINDS AND MVFR ON THE
BACK SIDE OF THE LOW. AS FOR ASTORIA...AT THIS TIME EXPECT THE
DEFORMATION PRECIP TO MOVE OVER LATE THIS EVENING AND OVERNIGHT.
RIGHT NOW EXPECTING MOSTLY RAIN...BUT IF THE HEAVIER PRECIP PASSES
OVERHEAD...EXPECT A CHANGEOVER TO A RAIN/SNOW MIX OR POSSIBLY A
SHORT PERIOD OF JUST SNOW. WITH THE SURFACE EXPECTED TO REMAIN
FAIRLY WARM...CONFIDENCE IS LOW IN SIGNIFICANT ACCUMULATIONS. THE
RUC HRRR KEEPS THE HEAVIEST PRECIPITATION OFFSHORE...WITH A
VARIATION IN MODELS KEEPING HEAVY PRECIP OVER THE COAST AND COAST
RANGE. THIS WILL BEAR WATCHING. KMD
KPDX AND APPROACHES...VFR CONDITIONS PREVAIL WITH INCREASED CHANCES
OF LIGHT RAIN THROUGH THE EVENING. MVFR CIGS ARE POSSIBLE LATER
TONIGHT AS RAIN PICKS BACK UP. EXPECT SOUTHERLY WINDS TO INCREASE
AFTER 09Z...WITH A BRIEF PERIOD OF GUSTS NEAR 25 KT OR POSSIBLY
SLIGHTLY HIGHER KTS THROUGH EARLY SAT MORNING. THE BEST CHANCE IF IT
OCCURS WOULD BE FROM 9Z TO 15Z. THEN SHOWERS ON SATURDAY...SOME
WITH SMALL HAIL. VFR WITH MVFR AT TIMES. EXPECT THE COAST RANGE TO
BE OBSCURED WITH HEAVIER RAIN AND SNOW OVERNIGHT.
&&
.MARINE...THERE WAS A BRIEF BREAK IN GUSTY WINDS OVER THE COASTAL
WATERS EARLIER THIS AFTERNOON...BUT ARE ALREADY SEEING THEM
GRADUALLY INCREASE ONCE AGAIN. SMALL CRAFT CRITERIA GUSTS NEAR 25
KTS ARE EXPECTED EARLY THIS EVENING AND CONTINUE THROUGH TONIGHT
AS THE NEXT SYSTEM IMPACTS THE WATERS. A FEW GUSTS NEAR 30 KTS
REMAIN POSSIBLE OVERNIGHT AS THE LOW PUSHES INLAND...BUT NOT
EXPECTING WINDS ANY STRONGER DUE TO THE NORTHERLY DIRECTION OF THE
WINDS. EXPECT LITTLE CHANGE IN SEAS THROUGH SAT...WITH SEAS
REMAINING AROUND 12 TO 13 FT.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY FROM 1 AM TO 10 AM PDT SATURDAY FOR CENTRAL
WILLAMETTE VALLEY-SOUTH WILLAMETTE VALLEY.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 9 AM PDT
SATURDAY FOR COAST RANGE OF NORTHWEST OREGON.
WA...WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 9 AM PDT
SATURDAY FOR WILLAPA HILLS.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 PM PDT SATURDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 PM PDT
SUNDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE
OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 5 PM
PDT SATURDAY.
&&
$$
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 STATE COLLEGE PA
612 PM EDT THU MAR 15 2012
.SYNOPSIS...
THE LARGE SCALE PATTERN WILL BE DOMINATED BY AN UPPER RIDGE WHICH
WILL KEEP US WARMER THAN NORMAL RIGHT INTO NEXT WEEK. A SLOW
MOVING WARM FRONT WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TODAY INTO FRIDAY. HIGH PRESSURE WILL WORK BACK IN
FOR THE WEEKEND AND LAST INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
REGIONAL RADAR SHOWS SCATTERED SHRA OVR THE SC MTNS SLOWLY MOVING
EASTWARD AND DISSIPATING...AS THEY ENCOUNTER BACK DOOR COLD FRONT
SWEEPING WEST FROM THE SUSQ VALLEY. FOCUS IN THE NEAR TERM WILL
SHIFT TOWARD THE EASTERN GRT LKS...WHERE CONVECTION IS ERUPTING IN
VICINITY OF WEAK LOW PRES SYSTEM AND ASSOC COLD FRONT. SEEMS THE
BEST CHANCE OF SHWRS AND STORMS OVERNIGHT WILL BE ACROSS NW
PA...AS THIS WEAK LO PRES SYS TRACKS ACROSS LK ERIE.
BACK DOOR COLD FRONT WILL PRESS WESTWARD OVERNIGHT...BRINGING A
COOLER/MARITIME AIR MASS...AND POSS STRATUS DECK LATE TONIGHT...INTO MUCH
OF CENTRAL PA EAST OF THE ALLEGHENIES. HOWEVER...LL JET WILL
TRANSPORT INCREASING MOIST/UNSTABLE AIR ALOFT OVR THE
REGION...BRINGING THE CHC OF SCT SHRA EVEN TO THE EASTERN HALF OF
THE STATE LATE TONIGHT.
HAVE LOWERED MIN TEMPS OVERNIGHT ACROSS THE SUSQ VALLEY BASED ON
UPSTREAM READINGS AND LATEST NAM12 BLYR TEMP FCST. STILL LOOKS
LIKE A VERY MILD NIGHT EVERYWHERE...WITH LOWS RANGING FROM THE
M/U50S ACROSS THE W MTNS...TO THE MID 40S EAST OF THE SUSQ RIVER.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE REGION FRIDAY
KEEPING THE LOCAL AREA UNSETTLED...WITH A CHANCE FOR SHOWERS AND
TSTMS IN THE FCST. ACTIVITY SHUD TAPER OFF FROM NW TO SE DURING
THE LAST HALF OF THE DAY AS THE SYSTEM EXITS THE REGION.
MILD TEMPERATURES WILL CONTINUE...THOUGH MAYBE NOT AS WARM AS
TODAY...HIGHS WILL TOP OUT IN THE MID 60S TO MID 70S WHICH IS
STILL 15-25 DEG ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
NOT A LOT OF CHANGE FROM RECENT DAYS.
HUGE RIDGE WILL CONTROL THE WEATHER WELL INTO NEXT WEEK...
AS A VERY DEEP TROUGH DIGS SOUTHWARD ACROSS THE FAR WEST...
WITH THE ZERO LINE AT 850 MB SOUTH OF CA.
ANY REMAINING CONVECTION WILL BE OUT OF THE AREA BY OR
SHORTLY 00Z SAT.
THERE COULD BE A SHOWER OR THUNDERSTORM AT ANY POINT...
MAINLY AFTERNOON AND THE EARLY EVENING HOURS...ACROSS
THE REGION SUNDAY AFTERNOON INTO THU...BUT LEFT FCST DRY...
AS NOTHING REALLY FOCUS ACTIVITY ON.
ASIDE FROM THE WEEKEND...WHERE TEMPS WILL BE A FEW DEGREES
COOLER...MAINLY ACROSS THE FAR EAST...WTIH SE FLOW...
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL. EVEN FOR THE
WEEKEND...TEMPS WILL STILL BE ABOVE NORMAL. WENT ABOVE
GUIDANCE. ENJOY.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
HIGH CLOUDS CONTINUE TO BLEED INTO THE LOCAL AREA OFF THE DYING
UPSTREAM CONVECTION. THE SHOWERS OVER THE NW ARE FADING FAST.
CHANCES FOR THUNDER TO REACH OUR NW TERMINALS SEEMS TO BE
DIMINISHING IN THE SHORT TERM...AT LEAST FOR THE NEXT 3-6 HOURS.
THE REST OF THE DAY INTO THE EVENING WILL BE SEE MOISTURE AND
INSTABILITY CONTINUE TO GRADUALLY INCREASE...MAINLY OVER WESTERN
AREAS. SHORT RANGE MODELS CONTINUE THE IDEA OF SOME CONVECTION
DEVELOPING UPSTREAM AND TRACKING OVER THE REGION
OVERNIGHT...ESPECIALLY THE HRRR AND HIGH RES ARW. EXPECT MORE
WIDESPREAD MVFR/IFR TO DEVELOP AS THE MOIST AIR AND PRECIP MOVE
ACROSS OVERNIGHT INTO EARLY FRIDAY.
FRIDAY WILL START OFF WITH MOST TERMINALS MVFR/IFR...WITH
CONDITIONS GRADUALLY IMPROVING AS THE DAY WEARS ON. THINK MOST OF
THE AREA WILL LIFT UP TO VFR BY AFTERNOON.
OUTLOOK...
SAT-TUE...VFR...WITH BRIEF REDUCTIONS POSSIBLE IN SCT
SHOWERS/ISOLD TSTMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
336 PM EDT THU MAR 15 2012
.SYNOPSIS...
THE LARGE SCALE PATTERN WILL BE DOMINATED BY AN UPPER RIDGE WHICH
WILL KEEP US WARMER THAN NORMAL RIGHT INTO NEXT WEEK. A SLOW
MOVING WARM FRONT WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TODAY INTO FRIDAY. HIGH PRESSURE WILL WORK BACK IN
FOR THE WEEKEND AND LAST INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
REGIONAL RADAR SHOWS SCATTERED CONVECTION SLOWLY MOVING EASTWARD
AND DISSIPATING. RUC MESO ANAL SHOWS THAT MID LEVEL LAPSE RATES
HAVE ACTUALLY DECREASED A BIT WITH A PRETTY ROBUST CAP REMAINING
OVER MOST OF THE AREA. MOST HUMID AND UNSTABLE AIRMASS REMAINS
OVER OHIO AND FAR WESTERN PA...WITH THE SHORT RANGE MODELS
CONTINUING TO ADVECT THE INSTABILITY EASTWARD LATER TODAY AND
TONIGHT.
HAVE DOWNPLAYED THE NEAR TERM CHANCES FOR RAIN THROUGH LATE DAY TO
BETTER MATCH THE SHORT TERM GUIDANCE AND TRENDS. SEEMS THE BEST
CHANCE TO TRACK SOME SHOWERS AND STORMS ACROSS WILL BE OVERNIGHT
AS CONVECTION THAT IS EXPECTED TO FIRE OVER OHIO AND THE LOWER
LAKES GETS STEERED ACROSS OUR FCST AREA.
USED THE SREF MIN TEMPS TONIGHT WHICH ARE WARMER THAN GMOS AND
LOOK MORE REASONABLE OVER MOST OF THE AREA. I MAY BE A LITTLE WARM
OVER THE FAR SE WHERE A MARITIME FLOW HAS DEVELOPED AND MAY ALLOW
MINS TO DROP BELOW 50. OTHERWISE THE MAJORITY OF THE FCST AREA WILL
BE VERY MILD...AVERAGING 20-30 DEG ABOVE NORMAL FOR THE WANING DAYS
OF WHAT HAS BEEN A VERY UNEVENTFUL WINTER.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
A WEAK BACK DOOR COLD FRONT WILL DROP SOUTH ACROSS THE REGION
FRIDAY KEEPING THE LOCAL AREA UNSETTLED...WITH A CHANCE FOR
SHOWERS AND TSTMS IN THE FCST. ACTIVITY SHUD TAPER OFF FROM NW TO
SE DURING THE LAST HALF OF THE DAY AS THE SYSTEM EXITS THE REGION.
MILD TEMPERATURES WILL CONTINUE...THOUGH MAYBE NOT AS WARM AS
TODAY...HIGHS WILL TOP OUT IN THE MID 60S TO MID 70S WHICH IS
STILL 15-25 DEG ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
NOT A LOT OF CHANGE FROM RECENT DAYS.
HUGE RIDGE WILL CONTROL THE WEATHER WELL INTO NEXT WEEK...
AS A VERY DEEP TROUGH DIGS SOUTHWARD ACROSS THE FAR WEST...
WITH THE ZERO LINE AT 850 MB SOUTH OF CA.
ANY REMAINING CONVECTION WILL BE OUT OF THE AREA BY OR
SHORTLY 00Z SAT.
THERE COULD BE A SHOWER OR THUNDERSTORM AT ANY POINT...
MAINLY AFTERNOON AND THE EARLY EVENING HOURS...ACROSS
THE REGION SUNDAY AFTERNOON INTO THU...BUT LEFT FCST DRY...
AS NOTHING REALLY FOCUS ACTIVITY ON.
ASIDE FROM THE WEEKEND...WHERE TEMPS WILL BE A FEW DEGREES
COOLER...MAINLY ACROSS THE FAR EAST...WTIH SE FLOW...
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL. EVEN FOR THE
WEEKEND...TEMPS WILL STILL BE ABOVE NORMAL. WENT ABOVE
GUIDANCE. ENJOY.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
HIGH CLOUDS CONTINUE TO BLEED INTO THE LOCAL AREA OFF THE DYING
UPSTREAM CONVECTION. THE SHOWERS OVER THE NW ARE FADING FAST.
CHANCES FOR THUNDER TO REACH OUR NW TERMINALS SEEMS TO BE
DIMINISHING IN THE SHORT TERM...AT LEAST FOR THE NEXT 3-6 HOURS.
THE REST OF THE DAY INTO THE EVENING WILL BE SEE MOISTURE AND
INSTABILITY CONTINUE TO GRADUALLY INCREASE...MAINLY OVER WESTERN
AREAS. SHORT RANGE MODELS CONTINUE THE IDEA OF SOME CONVECTION
DEVELOPING UPSTREAM AND TRACKING OVER THE REGION
OVERNIGHT...ESPECIALLY THE HRRR AND HIGH RES ARW. EXPECT MORE
WIDESPREAD MVFR/IFR TO DEVELOP AS THE MOIST AIR AND PRECIP MOVE
ACROSS OVERNIGHT INTO EARLY FRIDAY.
FRIDAY WILL START OFF WITH MOST TERMINALS MVFR/IFR...WITH
CONDITIONS GRADUALLY IMPROVING AS THE DAY WEARS ON. THINK MOST OF
THE AREA WILL LIFT UP TO VFR BY AFTERNOON.
OUTLOOK...
SAT-TUE...VFR...WITH BRIEF REDUCTIONS POSSIBLE IN SCT
SHOWERS/ISOLD TSTMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
206 PM EDT THU MAR 15 2012
.SYNOPSIS...
THE LARGE SCALE PATTERN WILL BE DOMINATED BY AN UPPER RIDGE WHICH
WILL KEEP US WARMER THAN NORMAL RIGHT INTO NEXT WEEK. A SLOW
MOVING WARM FRONT WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TODAY INTO FRIDAY. HIGH PRESSURE WILL WORK BACK IN
FOR THE WEEKEND AND LAST INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
REGIONAL RADAR SHOWS SCATTERED CONVECTION SLOWLY MOVING EASTWARD
AND DISSIPATING. RUC MESO ANAL SHOWS THAT MID LEVEL LAPSE RATES
HAVE ACTUALLY DECREASED A BIT WITH A PRETTY ROBUST CAP REMAINING
OVER MOST OF THE AREA. MOST HUMID AND UNSTABLE AIRMASS REMAINS
OVER OHIO AND FAR WESTERN PA...WITH THE SHORT RANGE MODELS
CONTINUING TO ADVECT THE INSTABILITY EASTWARD LATER TODAY AND
TONIGHT.
HAVE DOWNPLAYED THE NEAR TERM CHANCES FOR RAIN THROUGH LATE DAY TO
BETTER MATCH THE SHORT TERM GUIDANCE AND TRENDS. SEEMS THE BEST
CHANCE TO TRACK SOME SHOWERS AND STORMS ACROSS WILL BE OVERNIGHT
AS CONVECTION THAT IS EXPECTED TO FIRE OVER OHIO AND THE LOWER
LAKES GETS STEERED ACROSS OUR FCST AREA.
USED THE SREF MIN TEMPS TONIGHT WHICH ARE WARMER THAN GMOS AND
LOOK MORE REASONABLE OVER MOST OF THE AREA. I MAY BE A LITTLE WARM
OVER THE FAR SE WHERE A MARITIME FLOW HAS DEVELOPED AND MAY ALLOW
MINS TO DROP BELOW 50. OTHERWISE THE MAJORITY OF THE FCST AREA WILL
BE VERY MILD...AVERAGING 20-30 DEG ABOVE NORMAL FOR THE WANING DAYS
OF WHAT HAS BEEN A VERY UNEVENTFUL WINTER.
&&
.SHORT TERM /FRIDAY/...
A WEAK BACK DOOR COLD FRONT WILL DROP SOUTH ACROSS THE REGION
FRIDAY KEEPING THE LOCAL AREA UNSETTLED...WITH A CHANCE FOR
SHOWERS AND TSTMS IN THE FCST. ACTIVITY SHUD TAPER OFF FROM NW TO
SE DURING THE LAST HALF OF THE DAY AS THE SYSTEM EXITS THE REGION.
MILD TEMPERATURES WILL CONTINUE...THOUGH MAYBE NOT AS WARM AS
TODAY...HIGHS WILL TOP OUT IN THE MID 60S TO MID 70S WHICH IS
STILL 15-25 DEG ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
RIDGE STRENGTHENS OVER THE REGION FRI NIGHT THROUGH SUNDAY. THIS
WILL KEEP TEMPERATURES UNSEASONABLY MILD...EVEN WITH LIGHT
NORTHERLY FLOW FRI NIGHT. RETURN FLOW BEGINS ANEW LATER SAT AS
HEIGHTS BEGIN TO BUILD...THOUGH SE FLOW COULD TEMPER MAXES A BIT
SAT. SHORTWAVE DOES SLIDE INTO THE OHIO VALLEY ON SUNDAY...WHICH
MAY KICK OFF ISOLATED SHOWERS/TSTMS IN LAUREL HIGHLANDS...BUT
OTHERWISE IT SHOULD REMAIN DRY THIS WEEKEND.
NOTICEABLY ABOVE NORMAL TEMPS WILL LINGER THROUGH NEXT WEEK...AS VERY
DEEP SYSTEM OVER THE WEST TRANSITIONS INTO A NEARLY STATIONARY
CLOSED LOW OVER THE MISSOURI VALLEY. PRECIP CHANCES REMAIN LOW...BUT
DO BEGIN TO INCREASE BY NEXT WEEKEND. TEMPERATURES REMAIN ABOUT 25F
ABOVE NORMAL.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
HIGH CLOUDS CONTINUE TO BLEED INTO THE LOCAL AREA OFF THE DYING
UPSTREAM CONVECTION. THE SHOWERS OVER THE NW ARE FADING FAST.
CHANCES FOR THUNDER TO REACH OUR NW TERMINALS SEEMS TO BE
DIMINISHING IN THE SHORT TERM...AT LEAST FOR THE NEXT 3-6 HOURS.
THE REST OF THE DAY INTO THE EVENING WILL BE SEE MOISTURE AND
INSTABILITY CONTINUE TO GRADUALLY INCREASE...MAINLY OVER WESTERN
AREAS. SHORT RANGE MODELS CONTINUE THE IDEA OF SOME CONVECTION
DEVELOPING UPSTREAM AND TRACKING OVER THE REGION
OVERNIGHT...ESPECIALLY THE HRRR AND HIGH RES ARW. EXPECT MORE
WIDESPREAD MVFR/IFR TO DEVELOP AS THE MOIST AIR AND PRECIP MOVE
ACROSS OVERNIGHT INTO EARLY FRIDAY.
FRIDAY WILL START OFF WITH MOST TERMINALS MVFR/IFR...WITH
CONDITIONS GRADUALLY IMPROVING AS THE DAY WEARS ON. THINK MOST OF
THE AREA WILL LIFT UP TO VFR BY AFTERNOON.
OUTLOOK...
SAT-TUE...VFR...WITH BRIEF REDUCTIONS POSSIBLE IN SCT
SHOWERS/ISOLD TSTMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
656 PM CDT FRI MAR 16 2012
.UPDATE...
CONVECTION ACROSS SOUTHERN KY LOOKS TO BE MOVING NEARLY DUE EAST
AT THIS HOUR. RUC DEPICTS THE LITTLE SHORTWAVE THAT IS TRIGGERING
THE PRECIP. CLOSE TO HOME...NOT SEEING ANY CONVECTION UPSTREAM AT
THIS POINT. LARGE DEVIATION WITH THE CURRENT FCST AS OPPOSED TO
THE NUMERICAL GUIDANCE. THROUGH 12Z...I AM NOT SEEING MUCH OF ANY
INCREASE IN TERMS OF MOISTURE DEPTH OR OVERALL LIFT. ALTHOUGH THE
NAM DOES HINT TOWARD A LATE NIGHT IMPULSE AIDING WITH THE VERTICAL
LIFT LATE.
FOR THE FORECAST...I WILL INCREASE POPS TO 30 PERCENT AFTER
MIDNIGHT. OTW...WITH DEWPOINTS NEAR FCST LOWS...I SEE NO REASON TO
ADJUST TEMPS. REMAINDER OF FCST IS IN GOOD SHAPE. UPDATE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 654 PM CDT FRI MAR 16 2012/
UPDATE...FOR 00Z TAFS.
AVIATION...
MODERATE MOISTURE REMAINING IN VERY WEAK ML/UL RIDGES...AS WELL
AS SERIES OF IMPULSES AND PRESENCE OF CONVECTIVE BOUNDARIES WILL
KEEP SHOWERS/STORMS PASSING FROM-TO-TIME THRU THE PERIOD. BEST
TIMEFRAME FOR STORMS SEEMINGLY 18-23Z SAT...ALTHOUGH ISOLATED
LATE NIGHT DEVELOPMENT IS ALSO EXPECTED. OUTSIDE OF CONVECTION...
VFR CONDITIONS WILL LARGELY PREVAIL ALTHOUGH SOME EARLY MORNING
FOG MAY ALSO FORM.
PREV DISCUSSION... /ISSUED 335 PM CDT FRI MAR 16 2012/
DISCUSSION...
FORECAST REASONING WILL LEAN TOWARD A CONSENSUS MODEL SOLUTION
COMPROMISE FOR THE FORECAST PERIOD UNLESS OTHERWISE NOTED.
MAIN FORECAST QUANDARIES...PROBABILITY OF PRECIPITATION(POPS)...TEMPS...
OVERALL WX PATTERN NEXT WEEK.
AS FOR TONIGHT...WILL BE MONITORING RADAR TRENDS THRU PRESS TIME FOR
FINAL DECISION(S)...BUT AT THIS TIME...IT LOOKS LIKE THAT THERE HAS BEEN
SOME RECOVERY IN THE AIRMASS ACROSS WRN PORTIONS OF THE MID STATE...BUT
NO INDICATION OF SHWR/TSTM DEVELOPMENT...WITH ONLY ACTIVITY NOTED ACROSS
THE PLATEAU REGION. WITH A FEW MORE HRS OF POSSIBLE DIURNAL INFLUENCES
KICKING IN TO INITIATE ISOLATED SHWRS/TSTMS...WILL CONTINUE TO
KEEP THEM IN THE FORECAST THRU THE MID EVENING HRS...WITH SCT SHWRS/TSTMS
ACROSS THE PLATEAU THRU THE MID EVENING HRS ALSO. CAN ALSO NOT RULE OUT
.EVEN WITH DIURNAL INFLUENCES ENDING...ISO SHWRS/TSTMS ACROSS THE
ENTIRE MID STATE THRU TONIGHT PER THIS OPEN GULF MOISTURE PATTERN.
SOME INDICATION ALSO THAT RIDGING INFLUENCES WILL BEGIN THE PROCESS OF
STRENGTHENING THRU THE NIGHT HRS ALSO. BELIEVE GFS/NAM MOS GUIDANCE VALUES
ARE REASONABLE HERE...AND WILL ONLY MAKE SOME SLIGHT ADJUSTMENTS HERE AND
THERE...WITH ENOUGH MOISTURE TO SUPPORT A MIXTURE OF PTCLDY/MOCLDY SKIES.
AS FOR SAT...EXPECT THIS MIXTURE OF PTCLDY/MOCLDY SKIES TO CONTINUE...
WITH A SLIGHT UPPER LEVEL PATTERN AMPLIFICATION PATTERN ALSO CONTINUING.
HOWEVER...WITH SUCH A PRONOUNCED OPEN GULF MOISTURE PATTERN...CAN NOT RULE
OUT SCT MAINLY DIURNAL BASED SHWRS/TSTMS UNTIL A MORE MAJOR UPPER LEVEL
AMPLIFICATION OCCURS. EXPECT A LITTLE WARMER TEMPS THAN TODAY...AND WILL
GO WITH HIGHS AROUND 80 NW TO LOWER 80S S...UPPER 70S PLATEAU.
AS FOR SAT NIGHT...LOOKS LIKE UPPER LEVEL RIDGING INFLUENCES WILL ENHANCE
ENOUGH BY LATE SAT NIGHT TO WARRANT ONLY A SLIGHT CHANCE OF SHWRS/TSTMS
ACROSS THE MID STATE. BELIEVE WE WILL AT LEAST EXPERIENCE A DECREASING
CLOUDINESS TREND...WITH LOWS MAINLY IN THE MID 50S.
AS FOR SUN...EVEN WITH RIDGING ENHANCEMENTS BECOMING EVEN MORE ENTRENCHED
AS SUN PROGRESSES...DO NOT THINK RIDGING DYNAMICS WILL BE STRONG ENOUGH TO
SUPPRESS ALL CONVECTION...THUS WILL GO WITH A SLIGHT CHANCE OF SHWRS/TSTMS.
THIS COULD BE THE WARMEST DAY ON TAP...WITH AFTERNOON HIGH TEMPS POSSIBLY
APPROACHING RECORD VALUES IN SOME LOCATIONS...MID 80S...UPPER 70S PLATEAU.
AS FOR SUN NIGHT...UPPER LEVEL RIDGING DYNAMICS SHOULD FINALLY BECOME
ENHANCED ENOUGH...ALONG WITH ANY SHWR/TSTM ACTIVITY DIMINISHING QUICKLY
AFTER SUNSET PER DIURNAL LIFTING MECHANISMS ENDING...TO GO WITH DRY
CONDITIONS...PTCLDY SKIES...AND LOWS MAINLY IN THE MID 50S.
AS FOR THE REMAINDER OF THE FORECAST PERIOD...MODEL CONSENSUS DEVELOPING
A STRONG UPPER LEVEL TROUGH ACROSS THE WRN U.S. IN ASSOCIATION WITH THE
UPPER LEVEL RIDING ACROSS OUR NECK OF THE WOODS...AND SLOWLY MOVING THIS
UPPER LEVEL SYSTEM EWD MON AND TUE. HOWEVER...AFTER TUE...SOME SIGNIFICANT
MODEL DIFFERENCES OCCUR...WITH THE EURO SOLUTION MOVING THIS UPPER LEVEL
SYSTEM THRU THE MID STATE ON WED...WITH DRY CONDITIONS THEREAFTER...THE
GFS MOVING THIS SYSTEM MUCH SLOWER ACROSS THE MID STATE...WITH A WELL
DEFINED UPPER LEVEL LOW PROGRESSING BEHIND OF IT...MEANING SHWRS/TSTM
CHANCES THRU THU NIGHT...AND WITH THE DGEX MOVING IT THE SLOWEST...WITH
THE MORE WELL DEFINED CLOSED UPPER LEVEL LOW INFLUENCING THE MID STATE`S
WX WITH SHWRS/TSTMS THRU NEXT FRI EVENING. AM GOING TO LEAN TOWARD THE
MIDDLE OF THE ROAD GFS SOLUTION HERE...WITH PARTICULAR UPPER LEVEL CLOSED
LOW DEVELOPMENT AND MOVEMENT KEY HERE...AS IT SEEMS GENERALLY THE MOST
REASONABLE. THUS...WILL GO WITH A CHANCE OF SHWRS/TSTMS THRU THU NIGHT...
BUT CAN NOT RULE OUT FRI ALSO...AND WILL CONTINUE WITH THAT MENTIONING
HERE...BUT WILL KEEP FRI NIGHT DRY. A CONTINUATION OF UNSEASONABLY WARM
TEMPS WILL CONTINUE AT LEAST FOR THE FIRST PART OF THE WEEK...WITH
HIGHS MAINLY IN THE LOWER TO MID 80S...AROUND 80 PLATEAU...FALLING TO
AROUND 70...MID 60S PLATEAU...BY FRI. LOWS WILL BE IN THE MID 50S...
COOLING TO AROUND THE UPPER 40S TO AROUND 50...MID 40S PLATEAU...BY
FRI NIGHT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
645 PM CDT FRI MAR 16 2012
.AVIATION...
INITIAL PERIOD WILL FOCUS ON OPPORTUNITY OF THUNDERSTORM ACTIVITY.
DRYLINE LOCATED JUST WEST OF KLBB COULD FIRE ONE OR TWO MORE
STORMS THIS EVENING THAT COULD IMPACT THAT TERMINAL THOUGH THE
MORE SIGNIFICANT TSRA EXISTS UP AS KCDS AS CONVECTION CONTINUES TO
MOVE IN THAT DIRECTION.
AFTER MIDNIGHT...FOCUS WILL SHIFT TO FOG AT BOTH TERMINALS AND WE
COULD SEE CONDITIONS BELOW MINIMUMS TOWARD MORNING. AS THE DAY
PROGRESSES...WIND WILL BE THE PRIMARY CONSIDERATION WITH PERHAPS A
SLIGHT RISK OF BLDU AT KLBB IN THE AFTN.
&&
.PREV DISCUSSION... /ISSUED 358 PM CDT FRI MAR 16 2012/
SHORT TERM...
THE FORECAST AND SEVERE WEATHER PARAMETERS ARE PROGRESSING AS
EXPECTED FROM THIS MORNINGS UPDATE. LATEST RUC ANALYSIS INDICATES
3500 J/KG OF SURFACE INSTABILITY NOSING INTO THE AREA WITH AREAS
OF HIGH THETA-E AIR AND NO SURFACE BASED CIN. DEEP LAYER SHEAR
CONTINUES TO INCREASE OVER THE AREA WITH ABOUT 30KT OBSERVED.
ADDITIONALLY...A LARGE AREA OF ACCAS HAS BEEN OBSERVED SOUTH AND
SOUTHWEST OF THE LUBBOCK AREA. WILL CONTINUE TO EXPECT AN
INITIATION TIME AFTER 21Z. THE PRIMARY SEVERE THREAT REMAINS AS
LARGE HAIL AND DAMAGING WINDS. DESPITE SUPERCELLULAR STRUCTURE
EXPECTED WITH STORMS...TORNADOES ARE NOT AS LIKELY DUE TO THE VERY
WEAK LOW LEVEL SHEAR.
FOG IS AGAIN EXPECTED TONIGHT AND COULD BECOME DENSE AGAIN ON THE
CAPROCK. THE DRYLINE IS EXPECTED TO MIX FURTHER EAST SATURDAY
AFTERNOON. THE CAP IS PROGGED TO BE NEARLY ZERO OFF THE CAPROCK
WITH VERY STRONG SURFACED BASED CAPE IN EXCESS OF 3 KJ/KG.
HOWEVER...THERE WILL BE A LACK OF LARGE SCALE LIFT TOMORROW
AFTERNOON WITH ONLY WEAK LOW LEVEL CONVERGENCE ALONG THE DRYLINE.
WILL KEEP THE SLIGHT CHANCE GOING FOR SATURDAY AFTERNOON GIVEN
THESE PARAMETERS IN PLACE. JDV
LONG TERM...
ANOTHER WEAK DISTURBANCE LOOKS TO MOVE OVER THE AREA SATURDAY
NIGHT INTO EARLY SUNDAY MORNING BUT POINT SOUNDINGS SHOW A PRETTY
STRONG CAP IN PLACE THAT MAY LIMIT STORM CHANCES SOMEWHAT. CHANCES
FOR STORMS...A FEW ONCE AGAIN POSSIBLY SEVERE...LOOKS TO BE BETTER
SUNDAY NIGHT INTO MONDAY MORNING AS A COMBINATION OF THE APPROACH
OF THE MAIN LOW...INCREASING DEEP LAYER SHEAR AND CURVED LOW-LEVEL
HODOGRAPH...AND INCREASING MOISTURE IN THE LOWER ATMOSPHERE THANKS
TO A LOW-LEVEL JET ALL CONTRIBUTE TO DECENT INSTABILITY LEVELS.
DID INCREASE POPS FOR SUNDAY NIGHT THROUGH MONDAY MORNING AS THE
DRYLINE/PACIFIC FRONT HELPS TO FOCUS SURFACE CONVERGENCE AND THEN
CLEAR PRECIPITATION OUT FROM WEST TO EAST THROUGH THE MORNING.
OTHER CONCERN WITH THE SYSTEM AS IT MOVES OUT ACROSS THE AREA WILL
BE FIRE WEATHER FOR MONDAY. SEE FIRE WEATHER DISCUSSION SECTION
FOR MORE DETAILS. DRY AIR WILL RAPIDLY SWEEP IN ON A BREEZY TO
WINDY WESTERLY WIND DURING THE DAY MONDAY. MODELS HAVE COME INTO
BETTER AGREEMENT ON DEVELOPING THE TROF INTO A CLOSED LOW AND
TAKING IT FURTHER EAST RATHER THAN PREVIOUS RUNS KEEPING IT CLOSER
TO THE FORECAST AREA. FORECAST PARAMETERS WILL DEPEND ON WHETHER
WE WILL HAVE WEAK SHORTWAVE RIDGING OR ZONAL FLOW ACROSS THE AREA.
DRY AIR WILL SLOWLY MODIFY AT THE SURFACE THROUGH THE END OF NEXT
WEEK WHICH WILL KEEP THE FORECAST DRY. HOWEVER...FOCUS IS ON
SEVERE WEATHER POTENTIAL FOR THE NEXT SEVERAL DAYS SO MOST OF THE
EXTENDED FORECAST WAS NOT CHANGED.
JORDAN
FIRE WEATHER...
ELEVATED TO LOW END CRITICAL FIRE WEATHER CONDITIONS WILL BE
LIKELY SATURDAY AFTERNOON ACROSS THE WESTERN SOUTH PLAINS. A
SURFACE TROUGH WILL STRENGTHEN SATURDAY AFTERNOON LEADING TO GUSTY
SOUTHWEST WINDS ON THE WEST SIDE OF A DRYLINE. THIS DRYLINE WILL
MOVE TO THE EDGE OF THE CAPROCK TOMORROW AFTERNOON WITH VERY DRY
AIR TO THE WEST OF THIS FEATURE. GUSTY WINDS COMBINED WITH VERY
WARM TEMPERATURES WILL LEAD TO THE ELEVATED OR LOW END CRITICAL
FIRE WEATHER CONDITIONS. ANOTHER MORE WIDESPREAD FIRE WEATHER
EVENT WILL BE POSSIBLE ON SUNDAY AS STRONG WESTERLY WINDS AND DRY
AIR PUSH INTO THE REGION BEHIND A DEPARTING STORM SYSTEM.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 46 84 52 81 46 / 10 0 0 20 30
TULIA 53 83 58 80 49 / 20 10 20 30 40
PLAINVIEW 51 82 58 81 50 / 30 10 20 30 50
LEVELLAND 51 82 59 82 50 / 30 10 10 30 40
LUBBOCK 54 83 60 81 53 / 30 10 20 30 50
DENVER CITY 52 82 56 84 50 / 30 10 10 20 40
BROWNFIELD 53 83 60 83 51 / 40 10 20 30 40
CHILDRESS 57 84 62 80 60 / 30 20 20 30 60
SPUR 55 83 61 80 58 / 40 20 20 30 50
ASPERMONT 59 80 64 79 59 / 40 20 20 30 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR THE FOLLOWING ZONES:
TXZ021>023-027-028-033-034-039-040.
&&
$$
99/99/26
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
952 PM EDT FRI MAR 16 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL MAINTAIN A MOIST
SOUTHWEST FLOW OF AIR ACROSS THE REGION. WEAK UPPER LEVEL IMPULSES
WILL PASS FROM THE OHIO VALLEY ACROSS THE MID ATLANTIC REGION
HELPING TO TRIGGER SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS.
A COLD FRONT WILL MOVE SOUTH THROUGH THE MID ATLANTIC STATES
TONIGHT AND SATURDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 931 PM EDT FRIDAY...
SHOWERS ARE JUST ABOUT OUT OF THE NW PIEDMONT OF NC. ANOTHER AREA
OF SHRA/TSRA MOVING ACROSS E TN INTO WRN NC JUST SOUTH OF THE NC
MTNS. LATEST HRRR AND LOCAL WRF TAKE THIS BATCH OF SHOWERS INTO
THE MTNS OF NC AND FOOTHILLS THROUGH EARLY OVERNIGHT. WEAKENING
TREND WITH LOSS OF HEATING WILL LEAD TO ONLY ISOLATED TSRA. WILL
KEEP HIGHER POPS IN THE SOUTH...WITH LESS TO NONE IN THE NRN CWA.
FOG WILL ALSO FORM TONIGHT AS THE GROUND/LOW LVLS STAY MOIST.
BACKDOOR FRONT OVER NRN/ERN VA WILL SLIDE SW TOWARD THE AREA BY
EARLY MORNING...ALTHOUGH MODELS KEEP STABLE LAYER ACROSS THE
PIEDMONT NE OF LYH THROUGH DAWN. EXPECT TO SEE TEMPS DROP TOWARD
THE UPPER 40S IN THE NW/N AND ALONG THE MTNS OF NC LATE...WITH 50S ELSEWHERE.
TEMPERATURES TRICKY FOR TOMORROW. EASTERLY FLOW SHOULD KEEP
TEMPERATURES ALONG AND EAST OF THE BLUE RIDGE COOL AND BELOW
GUIDANCE. THAT IS...IF THE AREA CAN MAINTAIN CLOUD COVER. DEW
POINTS BEHIND THE BOUNDARY ARE STILL MUGGY AND IN THE UPPER 40S TO
MID 50S. THEREFORE...IT LOOKS AS IF THE CLOUDS WILL REMAIN THROUGH
MOST OF TOMORROW. THE UPPER LEVEL TROUGH AND ASSOCIATED SHORT
WAVES SHOULD ALSO HELP MAINTAIN CLOUD COVER AND PROVIDE RAIN IN
THE AFTERNOON. DID WARM TEMPERATURES UP FROM PREVIOUS FORECAST BUT
KEPT IT COOLER THAN GUIDANCE ALONG AND EAST OF THE BLUE RIDGE.
DOWNSLOPING FLOW WILL HELP THE WESTERN SLOPES WARM ABOVE
NORMAL...ESPECIALLY AS RAIN PULLS OUT BY AFTERNOON.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 310 PM EDT FRIDAY...
FORECAST WILL BE DOMINATED BY SUB-SYNOPTIC SCALE PHENOMENA
SUNDAY-MONDAY AS SEVERAL SHORT-WAVES TRANSIT THROUGH THE BROAD UPPER
RIDGE LOCATED OVER THE EASTERN STATES. EXPECT THIS ENERGY TO
INTERACT WITH A MOIST AND FAIRLY UNSTABLE AIR MASS TO BRING CHANCES
FOR SHOWERS AND A FEW THUNDERSTORMS THROUGH MUCH OF THE PERIOD. WENT
MAINLY WITH DIURNAL/TERRAIN DRIVEN POP TRENDS WITH HIGHEST IN THE
MOUNTAINS AND IN THE AFTERNOON. TEMPS WILL REMAIN VERY WARM AS
HEIGHTS/THICKNESSES CONTINUE IN THE LATE SPRING/EARLY SUMMER
PATTERN THAT HAS BROUGHT WIDESPREAD RECORD WARMTH TO MUCH OF THE
EASTERN CONUS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 250 PM EDT THURSDAY...
EXTENDED FORECAST IS LITTLE CHANGED IN THE OVERALL SYNOPTIC PATTERN
WITH THE DEEP WESTERN TROUGH AND STRONG UPPER RIDGE STILL DOMINANT
OVER THE CONUS. THE TENDENCY IS FOR THE TROUGH TO EDGE EASTWARD AS
THE WEEK PROGRESSES. GFS ENSEMBLES SHOW VERY LITTLE SPREAD IN THE H5
HEIGHT FIELD INTO WEDNESDAY WITH INCREASING SPREAD AMONG THE MEMBERS
AS NORTHERN STREAM ENERGY EVENTUALLY BEGINS TO CARVE OUT A CLOSED
LOW OVER THE WESTERN PLAINS BY LATE WED/THU WHICH IS THEN EJECTED
SLOWLY EASTWARD REACHING THE OH VALLEY BY AROUND FRIDAY DEPENDING ON
YOUR MODEL OF CHOICE. THE MID-WEEK PERIOD WILL BE CHARACTERIZED BY A
SCATTERED DIURNAL SHOWER REGIME DRIVEN BY WEAK SHORT-WAVES AND
PROBABLE OUTFLOW BOUNDARIES. AGAIN DIFFICULT TO PINPOINT COHERENT
SPATIAL/TEMPORAL COVERAGE PATTERN OTHER THAN HIGHER LIKELIHOOD OF
TYPICAL MOUNTAIN AND AFTERNOON TO EARLY EVENING ENHANCEMENT OF POPS.
INCREASING DEEP LAYER SOUTHERLY FLOW AHEAD OF THE ADVANCING UPPER
LOW SYSTEM WILL BRING INCREASED CHANCES FOR MORE ORGANIZED
PRECIPITATION LATE IN THE WEEK. TEMPS REMAINING IN THE WELL ABOVE
NORMAL (FOR MID-MARCH) RANGE THROUGHOUT THE WEEK RUNNING AT LEAST 10
TO 15F OVER SEASONAL NORMS.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
AS OF 735 PM EST FRIDAY...
SHOWERS AND EMBEDDED THUNDERSTORMS ARE LINED UP FROM KHLX-
KDAN. THE HIGHER INSTABILITY LIES ACROSS THE MOUNTAINS...SO NOT
ANTICIPATING ANY THUNDER IN DANVILLE. WILL KEEP TEMPO GROUP FOR
MVFR VSBY IN SHOWERS TIL 01Z.
WITH A HIGH LEVEL OF MOISTURE ON THE GROUND...AND SOME CLEARING
WITH A BACK DOOR FRONT ARRIVING LATE...MAY SEE SOME FOG
DEVELOPMENT AS WELL AS LOW STRATUS. THIS IS THE MAIN AVIATION
ISSUE INTO SAT MORNING...AND FORECAST CONFIDENCE IS MODERATE ON
WHICH WILL BE MORE IMPACTED. ATTM...WILL LEAN TOWARD MORE FOG AS
THINK ENOUGH CLOUD COVER FROM AC/CS WILL KEEP STRATUS FROM
FORMING. THE FOG STABILITY OFF THE SOUNDINGS SUGGEST BETTER FOG THREAT.
WITH THIS IN MIND WILL HAVE ROA/LYH/DAN DROP TO MVFR VSBYS FROM
08Z UNTIL 13Z. LYH COULD SEE SOME STRATUS...BUT NOT ENOUGH
CONFIDENCE FOR ADDING IT.
IN THE MTNS THINK BLF/LWB/BCB WILL SEE BETTER FOG THREAT ALTHOUGH
SOME MORE CLOUDINESS ARRIVING LATE COULD SEND VSBYS BACK UP AROUND
10-12Z. FOR NOW WILL BE BRING CIGS DOWN TO IFR OR LOWER AT BLF/LWB
WITH SCT LOWER CLOUDS IN BCB. VSBYS WILL DROP TO 1 TO 4SM.
THE FOG/LOWER CLOUDS WILL BE ERODING BY MID MORNING WITH THE FLOW
VARYING FROM NE IN THE LYH AREA TO SOUTH IN THE FAR WEST. ANOTHER
SHORTWAVE MOVES ACROSS SATURDAY INTERACTING WITH SFC BOUNDARY TO
SPARK ANOTHER ROUND OF SHOWERS/TSRA. ATTM...THE FAVORED AREAS WILL
BE SOUTH OF A LWB-ROA-DAN LINE...AND WILL ONLY ADD SHRA INTO BLF
FOR NOW. WILL SEE VFR CONDITIONS AFTER LATE MORNING AT ALL
SITES.
AN EASTERLY FLOW LOOKS TO PERSIST INTO SUNDAY. THIS MAY BRING SUB-
VFR CONDITIONS TO THE AREA IF THE AIR MASS IS ABLE TO BECOME
SATURATED IN THE BOUNDARY LAYER FROM EASTERLY UPSLOPE FLOW.
SCATTERED AFTERNOON SHOWERS AND STORMS MAY ALSO OCCUR ESPCLY
ALONG/WEST OF THE BLUE RIDGE WITH MVFR OR WORSE CONDITIONS NEAR
ANY CONVECTION. STRONG HIGH PRESSURE WILL BUILD ACROSS THE REGION
EARLY NEXT WEEK RESULTING IN WIDESPREAD VFR OUTSIDE OF ISOLATED
MAINLY AFTERNOON MOUNTAIN SHOWERS BOTH MONDAY AND TUESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RCS/WP
NEAR TERM...RCS/WP
SHORT TERM...PC
LONG TERM...PC
AVIATION...RCS/WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
120 PM CDT THU MAR 15 2012
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY THROUGH FRIDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE COLD
FRONT STRETCHING FROM LA CROSSE TO DOOR COUNTY EARLY THIS MORNING
AND SLOWLY SLIDING TO THE SOUTHEAST. WIDELY SCATTERED CONVECTION
FINALLY DEVELOPED ALONG THE FRONT ACROSS SOUTHEAST WISCONSIN AND
NORTHERN ILLINOIS...AND A FEW CELLS MAY GRAZE SHEBOYGAN COUNTY.
FARTHER NORTH...4-6KFT CLOUDS HAVE BEEN EXPANDING OVER NORTHEAST
WISCONSIN AND LAKE MICHIGAN WHILE PATCHY DENSE FOG HAS DEVELOPED
OVER CENTRAL WISCONSIN. AS NORTH TO NORTHEAST WINDS DEVELOP BEHIND
THE FRONT EARLY THIS MORNING...ANTICIPATING THE FOG TO DISSIPATE WITH
MOST OF IT GONE BY THE MORNING COMMUTE. WITH THE FRONT SETTLING TO
THE SOUTH TODAY...MAIN FORECAST CONCERNS REVOLVE AROUND SKY
CONDITIONS...FOG POTENTIAL...AND TEMPS.
TODAY...SURFACE COLD FRONT WILL SETTLE ACROSS THE SOUTHERN GREAT
LAKES TODAY WHILE HIGH PRESSURE MOVES ACROSS LAKE SUPERIOR. 850MB
FRONT WILL LAG TO THE NORTH OVER NORTHERN WISCONSIN...WHICH WILL
KEEP AMPLE MOISTURE IN THE 925-850MB LAYER. BEHIND THE
FRONT...SURFACE WINDS WILL TURN NE TO EASTERLY WHICH WILL ADVECT A
SHALLOW MARINE AIRMASS OVER MUCH OF NE WISCONSIN AND PARTIALLY INTO
CENTRAL WISCONSIN. PROGGED SOUNDINGS THIS MORNING ARE FOLDED
OVER...WITH THE RESIDUAL WARM AIRMASS LAYING OVER TOP THE RELATIVELY
COLDER MARINE AIRMASS...SUGGESTING A LAYER OF STRATUS OR FOG COULD
POSSIBLY FORM. THINK THIS PROCESS IS UNDER WAY OVER NORTHERN LAKE
MICHIGAN AS INDICATED BY THE GROWING DARK BLOB ON THE SATELLITE.
WILL INCREASE SKY COVER OVER MUCH OF NE AND E-C WISCONSIN...AND SOME
OVER CENTRAL WISCONSIN TOO FOR THIS MORNING. THINK THIS WILL EVOLVE
INTO A CU DECK WITH HEATING FOR THE AFTERNOON WITH PARTIAL CLEARING
ANTICIPATED. OVER N-C WISCONSIN...A VERY DRY AIRMASS WILL PUSH IN
FROM LAKE SUPERIOR...WITH DEWPOINTS TANKING ONCE AGAIN...WHICH WILL
SET UP A FAIRLY TIGHT DEWPOINT GRADIENT ACROSS THE FORECAST AREA.
CLOUDS AND AN EAST WIND WILL COOL TEMPS DOWN TODAY...AND WILL RANGE
FROM THE UPPER 50S NORTH TO UPPER 60S SOUTH...LOCALLY COOLER NEAR
LAKE MICHIGAN AND THE BAY OF GREEN BAY.
TONIGHT...VERY LITTLE CHANGES INTO TONIGHT. LIGHT RETURN FLOW WILL
BOW THE FRONT NORTHWARD INTO THE NORTHERN MISSISSIPPI VALLEY...WHILE
WE WILL STILL SEE LIGHT EAST FLOW NORTH OF THE BOUNDARY OVER
NORTHERN WISCONSIN. PROGGED SOUNDINGS INDICATE A SIMILAR INVERSION
DEVELOPING TONIGHT WITH A SHALLOW COOL AIRMASS IN PLACE. EVENING
HIGH CLOUDS WILL DEPART BY EARLY IN THE OVERNIGHT PERIOD...WHICH
WILL SUPPORT COOLING IN THE LOW LEVELS AND THE POSSIBILITY OF
STRATUS/FOG REFORMING. WILL INCREASE SKY COVER OVER NORTHEAST
WISCONSIN AND KEEP A MENTION OF PATCHY FOG IN THE FORECAST. LOWS
RANGING FROM THE MID 30S NORTH TO MID 40S SOUTH.
FRIDAY...THE FRONT WILL CONTINUE TO LIFT SLOWLY NORTHWARD ON
FRIDAY...POSSIBLY REACHING INTO CENTRAL WISCONSIN BY LATE IN THE
AFTERNOON. WITHOUT A GOOD PUSH ALOFT THOUGH...SOUTHEAST WINDS AT
THE SURFACE WILL KEEP THE SHALLOW MARINE AIR IN PLACE OVER THE REST
OF THE FORECAST AREA. MOISTURE IN THE 850-750MB LAYER WILL TRY TO
ROTATE INTO CENTRAL WISCONSIN AND THE NAM CREATES SOME ELEVATED CAPE
UP TO AROUND 700 J/KG IN THE AFTERNOON. IF THIS PANS OUT...NOT
SEEING A STRONG ENOUGH TRIGGER TO INITIATE CONVECTION...SO WILL
STICK WITH A DRY FORECAST. HIGHS RANGING FROM THE LOW 50S EAST TO
THE LOWER 70S WEST.
.LONG TERM...FRIDAY NIGHT THRU WEDNESDAY. MAIN FORECAST CONCERNS
ARE DEALING WITH CLOUD/FOG POTENTIAL...TEMPS...AND PRECIP CHANCES.
SUMMER-LIKE PATTERN TO CONTINUE INTO EARLY NEXT WEEK AS UPPER
RIDGE BUILDS ACROSS THE EASTERN CONUS...KEEPING TEMPS WELL ABOVE
NORMAL. AMAZING STRETCH OF LOW/MID 70S ARE EXPECTED SATURDAY
THROUGH TUESDAY...WITH RECORD HIGHS LIKELY. ONLY LOCATIONS NOT
PARTICIPATING IN THE VERY WARM AIR MASS WILL BE NEAR LAKE
MICHIGAN...WHERE TEMPS WILL STRUGGLE TO GET TO 60.
PRECIP CHANCES FAIRLY LOW AS WEAK DISTURBANCES STILL FORECAST TO
RIDE THE BACK SIDE OF THE EASTERN U.S. RIDGE. STILL TOUGH TO TIME
OUT THESE SMALL/WEAK DISTURBANCES THIS FAR IN ADVANCE. SO
CONFIDENCE REMAINS LOW ON THE TIMING/LOCATION OF THESE AND IF
THEY WILL BE ABLE TO GENERATE ANY SHOWER/STORM ACTIVITY. BEST
DISTURBANCE STILL LOOKS TO CROSS INTO THE GREAT LAKES SOMEWHERE
AROUND THE SATURDAY NIGHT TIME FRAME. MODELS HAVE DRIFTED A LITTLE
EAST WITH THIS FEATURE...KEEPING THE MAJORITY OF PRECIP IN LOWER
MICHIGAN. DUE TO THE TIMING/LOCATION CONCERNS...AND LACK OF UPPER
LEVEL SUPPORT...WILL KEEP SLIGHT CHANCE POPS FROM FRIDAY NIGHT
INTO SATURDAY NIGHT TO COVER SMALL THREAT OF SOME PRECIP ACTIVITY.
BY SUNDAY...THE UPPER RIDGE BUILDS OVER THE AREA TO KEEP PRECIP
CHANCES TO THE WEST...CLOSER TO THE DEEP UPPER TROUGH CROSSING
INTO THE PLAINS. THIS SYSTEM WILL BRING A DECENT CHANCE OF
SHOWERS/STORMS TO THE AREA MID-WEEK. STILL SOME DISAGREEMENT WITH
HOW THE MODELS HANDLE THE TROUGH AS IT CUTS OFF IN THE MID-
MISSISSIPPI VALLEY. STILL PLENTY OF TIME TO WORK ON THE DETAILS
WITH THIS SYSTEM...BUT CHANCES FOR WIDESPREAD INCREASE BY
WEDNESDAY.
LAKE MICHIGAN SHOULD SLOWLY LOSE ITS INFLUENCE ON ALL BUT THE
IMMEDIATE LAKESHORE BY SATURDAY AS WINDS TURN MORE SOUTHERLY
BEHIND THE WARM FRONT PUSHING NORTH OF THE AREA. FOG COULD LINGER
ON/NEAR LAKE MICHIGAN THROUGH THE WEEKEND...HOWEVER WILL JUST
CARRY THE MENTION FOR FRIDAY NIGHT AND SATURDAY NIGHT FOR NOW.
&&
.AVIATION...UNCERTAINTY INVOLVING CIGS AND VSBYS AGAIN TODAY. AN
AREA OF MVFR CIGS AROUND CWA/AUW SEEMED TO BE EXPANDING WHILE THE
MVFR CIGS AROUND ISW LOOKED TO BE SHRINKING. GUIDANCE WAS
INDICATING LIFR IN FOG AT GRB AND AUW LATE TONIGHT/EARLY FRIDAY.
TIME/HEIGHT SECTIONS SHOWED PLENTY OF MOISTURE AT THE SURFACE
DURING THE NIGHT IN MOST AREAS INTO FRIDAY MORNING. KEEP A CLOSE
WATCH ON TRENDS AS FORECASTER CONFIDENCE IS LOW.
MG
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
635 AM CDT THU MAR 15 2012
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE.
.SHORT TERM...TODAY THROUGH FRIDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE COLD
FRONT STRETCHING FROM LA CROSSE TO DOOR COUNTY EARLY THIS MORNING
AND SLOWLY SLIDING TO THE SOUTHEAST. WIDELY SCATTERED CONVECTION
FINALLY DEVELOPED ALONG THE FRONT ACROSS SOUTHEAST WISCONSIN AND
NORTHERN ILLINOIS...AND A FEW CELLS MAY GRAZE SHEBOYGAN COUNTY.
FARTHER NORTH...4-6KFT CLOUDS HAVE BEEN EXPANDING OVER NORTHEAST
WISCONSIN AND LAKE MICHIGAN WHILE PATCHY DENSE FOG HAS DEVELOPED
OVER CENTRAL WISCONSIN. AS NORTH TO NORTHEAST WINDS DEVELOP BEHIND
THE FRONT EARLY THIS MORNING...ANTICIPATING THE FOG TO DISSIPATE WITH
MOST OF IT GONE BY THE MORNING COMMUTE. WITH THE FRONT SETTLING TO
THE SOUTH TODAY...MAIN FORECAST CONCERNS REVOLVE AROUND SKY
CONDITIONS...FOG POTENTIAL...AND TEMPS.
TODAY...SURFACE COLD FRONT WILL SETTLE ACROSS THE SOUTHERN GREAT
LAKES TODAY WHILE HIGH PRESSURE MOVES ACROSS LAKE SUPERIOR. 850MB
FRONT WILL LAG TO THE NORTH OVER NORTHERN WISCONSIN...WHICH WILL
KEEP AMPLE MOISTURE IN THE 925-850MB LAYER. BEHIND THE
FRONT...SURFACE WINDS WILL TURN NE TO EASTERLY WHICH WILL ADVECT A
SHALLOW MARINE AIRMASS OVER MUCH OF NE WISCONSIN AND PARTIALLY INTO
CENTRAL WISCONSIN. PROGGED SOUNDINGS THIS MORNING ARE FOLDED
OVER...WITH THE RESIDUAL WARM AIRMASS LAYING OVER TOP THE RELATIVELY
COLDER MARINE AIRMASS...SUGGESTING A LAYER OF STRATUS OR FOG COULD
POSSIBLY FORM. THINK THIS PROCESS IS UNDER WAY OVER NORTHERN LAKE
MICHIGAN AS INDICATED BY THE GROWING DARK BLOB ON THE SATELLITE.
WILL INCREASE SKY COVER OVER MUCH OF NE AND E-C WISCONSIN...AND SOME
OVER CENTRAL WISCONSIN TOO FOR THIS MORNING. THINK THIS WILL EVOLVE
INTO A CU DECK WITH HEATING FOR THE AFTERNOON WITH PARTIAL CLEARING
ANTICIPATED. OVER N-C WISCONSIN...A VERY DRY AIRMASS WILL PUSH IN
FROM LAKE SUPERIOR...WITH DEWPOINTS TANKING ONCE AGAIN...WHICH WILL
SET UP A FAIRLY TIGHT DEWPOINT GRADIENT ACROSS THE FORECAST AREA.
CLOUDS AND AN EAST WIND WILL COOL TEMPS DOWN TODAY...AND WILL RANGE
FROM THE UPPER 50S NORTH TO UPPER 60S SOUTH...LOCALLY COOLER NEAR
LAKE MICHIGAN AND THE BAY OF GREEN BAY.
TONIGHT...VERY LITTLE CHANGES INTO TONIGHT. LIGHT RETURN FLOW WILL
BOW THE FRONT NORTHWARD INTO THE NORTHERN MISSISSIPPI VALLEY...WHILE
WE WILL STILL SEE LIGHT EAST FLOW NORTH OF THE BOUNDARY OVER
NORTHERN WISCONSIN. PROGGED SOUNDINGS INDICATE A SIMILAR INVERSION
DEVELOPING TONIGHT WITH A SHALLOW COOL AIRMASS IN PLACE. EVENING
HIGH CLOUDS WILL DEPART BY EARLY IN THE OVERNIGHT PERIOD...WHICH
WILL SUPPORT COOLING IN THE LOW LEVELS AND THE POSSIBILITY OF
STRATUS/FOG REFORMING. WILL INCREASE SKY COVER OVER NORTHEAST
WISCONSIN AND KEEP A MENTION OF PATCHY FOG IN THE FORECAST. LOWS
RANGING FROM THE MID 30S NORTH TO MID 40S SOUTH.
FRIDAY...THE FRONT WILL CONTINUE TO LIFT SLOWLY NORTHWARD ON
FRIDAY...POSSIBLY REACHING INTO CENTRAL WISCONSIN BY LATE IN THE
AFTERNOON. WITHOUT A GOOD PUSH ALOFT THOUGH...SOUTHEAST WINDS AT
THE SURFACE WILL KEEP THE SHALLOW MARINE AIR IN PLACE OVER THE REST
OF THE FORECAST AREA. MOISTURE IN THE 850-750MB LAYER WILL TRY TO
ROTATE INTO CENTRAL WISCONSIN AND THE NAM CREATES SOME ELEVATED CAPE
UP TO AROUND 700 J/KG IN THE AFTERNOON. IF THIS PANS OUT...NOT
SEEING A STRONG ENOUGH TRIGGER TO INITIATE CONVECTION...SO WILL
STICK WITH A DRY FORECAST. HIGHS RANGING FROM THE LOW 50S EAST TO
THE LOWER 70S WEST.
.LONG TERM...FRIDAY NIGHT THRU WEDNESDAY. MAIN FORECAST CONCERNS
ARE DEALING WITH CLOUD/FOG POTENTIAL...TEMPS...AND PRECIP CHANCES.
SUMMER-LIKE PATTERN TO CONTINUE INTO EARLY NEXT WEEK AS UPPER
RIDGE BUILDS ACROSS THE EASTERN CONUS...KEEPING TEMPS WELL ABOVE
NORMAL. AMAZING STRETCH OF LOW/MID 70S ARE EXPECTED SATURDAY
THROUGH TUESDAY...WITH RECORD HIGHS LIKELY. ONLY LOCATIONS NOT
PARTICIPATING IN THE VERY WARM AIR MASS WILL BE NEAR LAKE
MICHIGAN...WHERE TEMPS WILL STRUGGLE TO GET TO 60.
PRECIP CHANCES FAIRLY LOW AS WEAK DISTURBANCES STILL FORECAST TO
RIDE THE BACK SIDE OF THE EASTERN U.S. RIDGE. STILL TOUGH TO TIME
OUT THESE SMALL/WEAK DISTURBANCES THIS FAR IN ADVANCE. SO
CONFIDENCE REMAINS LOW ON THE TIMING/LOCATION OF THESE AND IF
THEY WILL BE ABLE TO GENERATE ANY SHOWER/STORM ACTIVITY. BEST
DISTURBANCE STILL LOOKS TO CROSS INTO THE GREAT LAKES SOMEWHERE
AROUND THE SATURDAY NIGHT TIME FRAME. MODELS HAVE DRIFTED A LITTLE
EAST WITH THIS FEATURE...KEEPING THE MAJORITY OF PRECIP IN LOWER
MICHIGAN. DUE TO THE TIMING/LOCATION CONCERNS...AND LACK OF UPPER
LEVEL SUPPORT...WILL KEEP SLIGHT CHANCE POPS FROM FRIDAY NIGHT
INTO SATURDAY NIGHT TO COVER SMALL THREAT OF SOME PRECIP ACTIVITY.
BY SUNDAY...THE UPPER RIDGE BUILDS OVER THE AREA TO KEEP PRECIP
CHANCES TO THE WEST...CLOSER TO THE DEEP UPPER TROUGH CROSSING
INTO THE PLAINS. THIS SYSTEM WILL BRING A DECENT CHANCE OF
SHOWERS/STORMS TO THE AREA MID-WEEK. STILL SOME DISAGREEMENT WITH
HOW THE MODELS HANDLE THE TROUGH AS IT CUTS OFF IN THE MID-
MISSISSIPPI VALLEY. STILL PLENTY OF TIME TO WORK ON THE DETAILS
WITH THIS SYSTEM...BUT CHANCES FOR WIDESPREAD INCREASE BY
WEDNESDAY.
LAKE MICHIGAN SHOULD SLOWLY LOSE ITS INFLUENCE ON ALL BUT THE
IMMEDIATE LAKESHORE BY SATURDAY AS WINDS TURN MORE SOUTHERLY
BEHIND THE WARM FRONT PUSHING NORTH OF THE AREA. FOG COULD LINGER
ON/NEAR LAKE MICHIGAN THROUGH THE WEEKEND...HOWEVER WILL JUST
CARRY THE MENTION FOR FRIDAY NIGHT AND SATURDAY NIGHT FOR NOW.
&&
.AVIATION...EARLY MORNING FOG WILL MOSTLY DISSIPATE AT THE TAF SITES
BY THE 12Z ISSUANCE AS A LIGHT NORTH TO NORTHEAST WIND DEVELOPS.
OTHERWISE...SCT TO BKN 4000-6000 FT WILL PREVAIL ACROSS THE REGION
FOR MUCH OF THE DAY. WINDS TURN LIGHT AGAIN TONIGHT WHICH COULD
LEAD TO MORE FOG FORMATION. CONFIDENCE IS LOW AGAIN...THOUGH
MARGINALLY BETTER CHANCES LOOK TO OCCUR OVER EASTERN WISCONSIN.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
328 AM CDT THU MAR 15 2012
.SHORT TERM...TODAY THROUGH FRIDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE COLD
FRONT STRETCHING FROM LA CROSSE TO DOOR COUNTY EARLY THIS MORNING
AND SLOWLY SLIDING TO THE SOUTHEAST. WIDELY SCATTERED CONVECTION
FINALLY DEVELOPED ALONG THE FRONT ACROSS SOUTHEAST WISCONSIN AND
NORTHERN ILLINOIS...AND A FEW CELLS MAY GRAZE SHEBOYGAN COUNTY.
FARTHER NORTH...4-6KFT CLOUDS HAVE BEEN EXPANDING OVER NORTHEAST
WISCONSIN AND LAKE MICHIGAN WHILE PATCHY DENSE FOG HAS DEVELOPED
OVER CENTRAL WISCONSIN. AS NORTH TO NORTHEAST WINDS DEVELOP BEHIND
THE FRONT EARLY THIS MORNING...ANTICIPATING THE FOG TO DISSIPATE WITH
MOST OF IT GONE BY THE MORNING COMMUTE. WITH THE FRONT SETTLING TO
THE SOUTH TODAY...MAIN FORECAST CONCERNS REVOLVE AROUND SKY
CONDITIONS...FOG POTENTIAL...AND TEMPS.
TODAY...SURFACE COLD FRONT WILL SETTLE ACROSS THE SOUTHERN GREAT
LAKES TODAY WHILE HIGH PRESSURE MOVES ACROSS LAKE SUPERIOR. 850MB
FRONT WILL LAG TO THE NORTH OVER NORTHERN WISCONSIN...WHICH WILL
KEEP AMPLE MOISTURE IN THE 925-850MB LAYER. BEHIND THE
FRONT...SURFACE WINDS WILL TURN NE TO EASTERLY WHICH WILL ADVECT A
SHALLOW MARINE AIRMASS OVER MUCH OF NE WISCONSIN AND PARTIALLY INTO
CENTRAL WISCONSIN. PROGGED SOUNDINGS THIS MORNING ARE FOLDED
OVER...WITH THE RESIDUAL WARM AIRMASS LAYING OVER TOP THE RELATIVELY
COLDER MARINE AIRMASS...SUGGESTING A LAYER OF STRATUS OR FOG COULD
POSSIBLY FORM. THINK THIS PROCESS IS UNDER WAY OVER NORTHERN LAKE
MICHIGAN AS INDICATED BY THE GROWING DARK BLOB ON THE SATELLITE.
WILL INCREASE SKY COVER OVER MUCH OF NE AND E-C WISCONSIN...AND SOME
OVER CENTRAL WISCONSIN TOO FOR THIS MORNING. THINK THIS WILL EVOLVE
INTO A CU DECK WITH HEATING FOR THE AFTERNOON WITH PARTIAL CLEARING
ANTICIPATED. OVER N-C WISCONSIN...A VERY DRY AIRMASS WILL PUSH IN
FROM LAKE SUPERIOR...WITH DEWPOINTS TANKING ONCE AGAIN...WHICH WILL
SET UP A FAIRLY TIGHT DEWPOINT GRADIENT ACROSS THE FORECAST AREA.
CLOUDS AND AN EAST WIND WILL COOL TEMPS DOWN TODAY...AND WILL RANGE
FROM THE UPPER 50S NORTH TO UPPER 60S SOUTH...LOCALLY COOLER NEAR
LAKE MICHIGAN AND THE BAY OF GREEN BAY.
TONIGHT...VERY LITTLE CHANGES INTO TONIGHT. LIGHT RETURN FLOW WILL
BOW THE FRONT NORTHWARD INTO THE NORTHERN MISSISSIPPI VALLEY...WHILE
WE WILL STILL SEE LIGHT EAST FLOW NORTH OF THE BOUNDARY OVER
NORTHERN WISCONSIN. PROGGED SOUNDINGS INDICATE A SIMILAR INVERSION
DEVELOPING TONIGHT WITH A SHALLOW COOL AIRMASS IN PLACE. EVENING
HIGH CLOUDS WILL DEPART BY EARLY IN THE OVERNIGHT PERIOD...WHICH
WILL SUPPORT COOLING IN THE LOW LEVELS AND THE POSSIBILITY OF
STRATUS/FOG REFORMING. WILL INCREASE SKY COVER OVER NORTHEAST
WISCONSIN AND KEEP A MENTION OF PATCHY FOG IN THE FORECAST. LOWS
RANGING FROM THE MID 30S NORTH TO MID 40S SOUTH.
FRIDAY...THE FRONT WILL CONTINUE TO LIFT SLOWLY NORTHWARD ON
FRIDAY...POSSIBLY REACHING INTO CENTRAL WISCONSIN BY LATE IN THE
AFTERNOON. WITHOUT A GOOD PUSH ALOFT THOUGH...SOUTHEAST WINDS AT
THE SURFACE WILL KEEP THE SHALLOW MARINE AIR IN PLACE OVER THE REST
OF THE FORECAST AREA. MOISTURE IN THE 850-750MB LAYER WILL TRY TO
ROTATE INTO CENTRAL WISCONSIN AND THE NAM CREATES SOME ELEVATED CAPE
UP TO AROUND 700 J/KG IN THE AFTERNOON. IF THIS PANS OUT...NOT
SEEING A STRONG ENOUGH TRIGGER TO INITIATE CONVECTION...SO WILL
STICK WITH A DRY FORECAST. HIGHS RANGING FROM THE LOW 50S EAST TO
THE LOWER 70S WEST.
.LONG TERM...FRIDAY NIGHT THRU WEDNESDAY. MAIN FORECAST CONCERNS
ARE DEALING WITH CLOUD/FOG POTENTIAL...TEMPS...AND PRECIP CHANCES.
SUMMER-LIKE PATTERN TO CONTINUE INTO EARLY NEXT WEEK AS UPPER
RIDGE BUILDS ACROSS THE EASTERN CONUS...KEEPING TEMPS WELL ABOVE
NORMAL. AMAZING STRETCH OF LOW/MID 70S ARE EXPECTED SATURDAY
THROUGH TUESDAY...WITH RECORD HIGHS LIKELY. ONLY LOCATIONS NOT
PARTICIPATING IN THE VERY WARM AIR MASS WILL BE NEAR LAKE
MICHIGAN...WHERE TEMPS WILL STRUGGLE TO GET TO 60.
PRECIP CHANCES FAIRLY LOW AS WEAK DISTURBANCES STILL FORECAST TO
RIDE THE BACK SIDE OF THE EASTERN U.S. RIDGE. STILL TOUGH TO TIME
OUT THESE SMALL/WEAK DISTURBANCES THIS FAR IN ADVANCE. SO
CONFIDENCE REMAINS LOW ON THE TIMING/LOCATION OF THESE AND IF
THEY WILL BE ABLE TO GENERATE ANY SHOWER/STORM ACTIVITY. BEST
DISTURBANCE STILL LOOKS TO CROSS INTO THE GREAT LAKES SOMEWHERE
AROUND THE SATURDAY NIGHT TIME FRAME. MODELS HAVE DRIFTED A LITTLE
EAST WITH THIS FEATURE...KEEPING THE MAJORITY OF PRECIP IN LOWER
MICHIGAN. DUE TO THE TIMING/LOCATION CONCERNS...AND LACK OF UPPER
LEVEL SUPPORT...WILL KEEP SLIGHT CHANCE POPS FROM FRIDAY NIGHT
INTO SATURDAY NIGHT TO COVER SMALL THREAT OF SOME PRECIP ACTIVITY.
BY SUNDAY...THE UPPER RIDGE BUILDS OVER THE AREA TO KEEP PRECIP
CHANCES TO THE WEST...CLOSER TO THE DEEP UPPER TROUGH CROSSING
INTO THE PLAINS. THIS SYSTEM WILL BRING A DECENT CHANCE OF
SHOWERS/STORMS TO THE AREA MID-WEEK. STILL SOME DISAGREEMENT WITH
HOW THE MODELS HANDLE THE TROUGH AS IT CUTS OFF IN THE MID-
MISSISSIPPI VALLEY. STILL PLENTY OF TIME TO WORK ON THE DETAILS
WITH THIS SYSTEM...BUT CHANCES FOR WIDESPREAD INCREASE BY
WEDNESDAY.
LAKE MICHIGAN SHOULD SLOWLY LOSE ITS INFLUENCE ON ALL BUT THE
IMMEDIATE LAKESHORE BY SATURDAY AS WINDS TURN MORE SOUTHERLY
BEHIND THE WARM FRONT PUSHING NORTH OF THE AREA. FOG COULD LINGER
ON/NEAR LAKE MICHIGAN THROUGH THE WEEKEND...HOWEVER WILL JUST
CARRY THE MENTION FOR FRIDAY NIGHT AND SATURDAY NIGHT FOR NOW.
&&
.AVIATION...THE LIKELIHOOD OF GETTING WIDESPREAD LOW CLDS AND FOG
IS DECREASING. WL MAINTAIN SOME MVFR FG LATER TNGT...BUT THEN
EXPECT MAINLY VFR CONDITIONS TOMORROW.
SKOWRONSKI
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/BERSCH
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
101 AM EDT SAT MAR 17 2012
.Update...
Issued at 945 PM EDT Fri Mar 16 2012
Have updated grids to mainly reflect latest position of scattered to
numerous showers across south central Kentucky associated with MCV.
Saw a lightning strike or two with the strongest updrafts earlier
this evening so will leave mention of isolated thunder in the
forecast. On an otherwise quiet evening, a few of the cells near the
Bowling Green region put on quite a show, displaying supercell
characteristics at times. Storms developed on a north south oriented
boundary across west central Kentucky and Tennessee, then maintained
sustained updrafts with deviant (right-moving) motion near Bowling
Green. Weak rotation was maintained on radar, with a spotter
observing weak rotation at times. How these cells were able to
maintain updrafts without any organized deep shear remains a mystery.
Showers associated with the MCV will slide across south central
Kentucky for the next few hours with only an isolated chance
elsewhere across the CWA. Still remains some question as to how the
overnight period will go with respect to weak isentropic lift
component across western CWA between 06-12Z so will just mention
isolated chances, however do expect coverage of precipitation to
gradually increase from southwest to northeast after 12Z. Best
chance for showers and thunderstorms still looks to be tomorrow
afternoon and evening as a shortwave moves through the region from
the southwest.
Forecast looks on track, with skies generally becoming partly cloudy
through the overnight. Will have to watch for fog potential as
recent rainfall combines with improving radiational cooling
conditions as skies clear and winds remain light and variable.
Tweaked lows down just a bit with most spots in the upper 50s and a
few locations hanging on around 60. Updated products already out.
Update issued at 654 PM EDT Fri Mar 16 2012
Showers have developed over the west central portion of the CWA with
MCV that is slowly rotating through western Kentucky. A look at
forecast soundings shows that updrafts should struggle above 15-20 K
feet as thermal profile warms significantly above this level. Do not
expect much more than a few moderate showers mainly across central
Kentucky, although cannot rule out an isolated thunderstorm or two.
Have tweaked pops just a bit through the overnight hours with the
potential for a scattered line of mainly showers to develop over the
Bowling Green region and lift northeastward from 06 to 12z. Models
disagree on the timing with NAM/GFS more toward dawn, however higher
res HRRR which has current situation handled well begins precip just
after 06 z. The main culprit appears to be some weak isentropic
lift with a weak low level jet. Will monitor trends and update
timing as needed. Otherwise, the rest of the forecast looks on track
at this point.
.Short Term (Tonight through Saturday Night)...
Updated at 255 PM EDT Mar 16 2012
Meso low continues to spin just to our west, now with a surface
reflection in latest MSAS analysis. Fortunately for us, persistent
cloud cover for most of the day so far has inhibited convection over
our CWA. Western Kentucky has been clearer though, and that area now
is seeing some convections, with cells initiating over eastern PAH`s
forecast area. Temperatures are climbing over the western forecast
area, so should start seeing some action there a little later this
afternoon, especially as that low drifts eastward.
Beyond this afternoon and through Saturday night, the atmosphere
will remain plenty moist for additional shower and storm
development. Confidence in timing/location still is not high though.
Precipitable waters will be above an inch. Will have multiple
perturbations in the flow aloft coming across the region, which will
enhance development, especially should these come during any peak
heating times. Given the moist atmosphere, diurnal temperature
swings should be short, and expect readings well above normal for
mid March. Going for lows each night around 60 and highs generally
in the upper 70s.
.Long Term (Sunday - Friday)...
Updated at 255 PM EDT Mar 16 2012
For Sunday, another shortwave in the upper level flow will cross the
Ohio Valley. The models are still having a bit of a hard time with
the timing and the placement of this feature. This will impact how
widespread storms become on Sunday. For now we will continue to
carry a 30-40% chance for thunderstorms. Soundings do become
relatively unstable during the day so a few of these storms may
become strong. These will be the pulse type like we have seen the
last couple of days, with hail being the main threat.
For the beginning of the work week, a highly amplified ridge will
build over the area. This will lead to partly cloudy skies and dry
weather Monday through Tuesday. At the surface, winds will remain
out of the south. Unseasonably warm temperatures will continue with
a shot at breaking some record highs Sunday through Monday.
Current records and forecast temps for Sun/Mon/Tues:
ASOS Sun(3/18) Mon(3/19) Tues(3/20)
Record/Forecast:
SDF 82(1982)/81 83(1907)/83 85(1894)/82
LEX 79(1982)/79 79(1945)/81 81(1894)/81
BWG 87(1908)/82 86(1907)/83 85(1921)/82
FFT 80(1908)/80 81(1948)/82 82(1921)/81
We will see a big change in the weather for the second half of the
week. A large upper level low will approach and cross the region
Wednesday through Friday. Clouds will be on the increase on
Wednesday, keeping temperatures a few degrees cooler than the
previous days. Rain from this system looks to move in Wednesday
night with showers and thunderstorms continuing into Friday as the
low slowly crosses the region. Temperatures will be much cooler
Thursday and Friday. Despite this, temps will remain above normal
for this time of year with highs in the mid 60s to lower 70s and
lows in the upper 40s to lower 50s.
&&
.Aviation (06Z TAF Issuance)...
Updated at 100 AM EDT Mar 17 2012
Scattered showers across central Kentucky are slowly moving
northeast as a MCV spins over the area. Would anticipate this
scattered activity to move near LEX and even perhaps SDF for the
next few hours. Could even see areal coverage increasing a bit.
Models continue to hint at additional shower development closer to
dawn, mainly in the BWG region. Will continue to monitor trends over
the next few hours, but upstream cloud cover has diminished. If the
clearing trend works into the area as this MCV slowly moves east
this morning and there is no more shower redevelopment, then some
MVFR BR at all TAF sites will be possible toward dawn. Given the
upstream observations/trends, will continue reduced visibility in
the forecast. While the additional shower development later this
morning remains uncertain, believe the best areal coverage will be
with the mid-level wave that will approach the area this afternoon
and into the evening hours. Calm or light southeasterly winds this
morning will become southwesterly between 5 and 10 mph for the
afternoon.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........BJS
Short Term.......RJS
Long Term........EER
Aviation.........MJP
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
403 AM CDT SAT MAR 17 2012
.DISCUSSION...
LATEST WV IMAGERY OVERLAID WITH RUC 400-500MB LAYER WINDS SHOWS
SUBTLE SHORTWAVE RESPONSIBLE FOR THE EVENING CONVECTION ACROSS
NORTHERN WISCONSIN HAS MOVED NORTHEAST. MEANWHILE...ANOTHER WEAK
WAVE IS FORCING A FEW SHOWERS ACROSS SOUTHWEST WISCONSIN...BUT
THIS WILL REMAIN SOUTH AND EAST OF THE FORECAST AREA. FURTHER
UPSTREAM ANOTHER SHORT WAVE LOCATED OVER KANSAS WILL MOVE
NORTHEAST TODAY...BUT IT TOO SHOULD TRACK SOUTH AND EAST OF THE
CWA. GIVEN THE SUMMER LIKE AIRMASS IN PLACE...AS INDICATED BY
THE TROPOPAUSE HEIGHT OF 225 MB VIA THE 00Z MPS RAOB...A SMALL
AMOUNT FORCING IS SUFFICIENT TO PRODUCE CONVECTION. HOWEVER...HAVE
KEPT THE FORECAST DRY FOR TODAY AND SUNDAY SINCE CONFIDENCE IS LOW
THAT SHOWERS AND THUNDERSTORMS WILL DEVELOP DESPITE THE HIGH CAPE
VALUES. THINKING IS THAT A WIDESPREAD CUMULUS FIELD WILL ENSUE
RATHER THAN ANY DEEP CONVECTION.
BY SUNDAY NIGHT A LONG WAVE TROUGH THAT IS CURRENTLY DIGGING OFF
THE COAST OF CALIFORNIA WILL BEGIN TO AFFECT THE UPPER MIDWEST.
MODELS SHOW A WEAK SHORTWAVE MOVING UP FROM THE SOUTHWEST IN
CONJUNCTION WITH A STRENGTHENING LOW LEVEL JET. THIS SHOULD
TRIGGER SOME SHOWER AND THUNDERSTORM DEVELOPMENT SUNDAY NIGHT INTO
MONDAY. THE BEST DYNAMICS REMAIN TO THE WEST IN THE VICINITY OF A
+120KT GET...SO DEEP LAYER SHEAR VALUES IN THE 20-25KT RANGE
INDICATE A MINIMAL THREAT FOR SEVERE WEATHER. THIS IS ALSO
SUPPORTED BY THE NARROW CAPE PROFILES IN THE FORECAST SOUNDINGS.
LOOKS LIKE SOME MUCH NEEDED RAIN SHOWERS WILL BE THE MAIN
RESULT...WITH A FEW SUB SEVERE THUNDERSTORMS MIXED IN AS WELL.
MODELS THEN TRANSITION THIS TROUGH TO A CUTOFF LOW ON WEDNESDAY
AND VARY IN LOCATION. THE GEM 17.00 IS FURTHEST SOUTH OVER
ARKANSAS...WHILE THE ECMWF TAKES IT ACROSS THE OHIO RIVER
VALLEY...AND THE GFS 17.00 IS SLOW TO MOVE THIS SYSTEM OUT FROM
THE CENTRAL CONUS. GIVEN THE MODEL UNCERTAINTY...DID NOT DEVIATE
MUCH FROM GUIDANCE IN THE EXTENDED.
&&
.AVIATION.../06Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED EARLY ON WITH FEW-SCT060-080 MOVING THROUGH
MAINLY EASTERN AREAS. WEAK WAVE LIFTING NORTHEAST OVER EASTERN NE
THIS EVENING...IS GENERATING A FEW OF THESE CLOUDS SOUTH OVER IOWA
AND MAY LIFT INTO THE AREA THIS MORNING. STILL A QUANDARY WHETHER
OR NOT STRATUS WILL DEVELOP DURING THE MORNING. STILL HAVE DECENT
PRESSURE GRADIENT/WINDS AROUND...AND WILL LIMIT VSBY REDUCTION
SOMEWHAT. DEWPOINTS REMAIN HIGH HOWEVER...AND BUFKIT PROFILES STILL
SUGGEST POSSIBLITY OF STRATUS DEVELOPMENT LATE. WILL HOLD ONTO SOME
OF THAT LIFR/IFR OVER WESTERN AREAS AND NOT SO MUCH TO THE EAST.
ONLY POSSIBLE PROBLEM WOULD BE KEAU WHICH SAW A TSRA THIS EVENING.
DO ANTICIPATE IFR LIFTING TO MVFR AND THEN VFR MOST AREAS THROUGN
19Z. MODELS SUGGEST QUITE A BIT OF LOW LEVEL RH AROUND SO WILL KEEP
A BKN VFR CEILING INTO THE AFTERNOON/EVENING. SOUTHEAST TO SOUTH
WINDS TO INCREASE AS GRADIENT INCREASES AHEAD OF WESTERN
TROUGH...GUSTS OVER 25KTS POSSIBLE...ESPECIALLY OVER WSTERN AREAS IN
THE AFTERNOON.
KMSP...FEW 060-080 CLOUDS AROUND THE AREA...AND SOME MAY YET WORK
NORTH THROUGH IOWA OVERNIGHT. THIS ALONG WITH CONTINUATION OF SOME
GRADIENT WIND SHOULD LIMIT SIGNIFICANT FOG FORMATION. STILL A
QUESTION AS TO WHETHER STRATUS DEVELOPMENT WILL TAKE PLACE. KEPT
SOME LOWER FEW005 IN THERE LATER TONIGHT BUT FEEL BEST THREAT OF IFR
CONDITIONS OCCURRING WILL BE FARTHER WEST. STILL ANTICIAPTE CLOUDS
TO START THE DAY...MIXING OUT IN THE AFTERNOON. SOUTHEAST TO SOUTH
WINDS EXPECTED TO INCREASE AS WELL AND BECOME GUSTY IN THE
AFTERNOON.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
153 AM EDT SAT MAR 17 2012
.SYNOPSIS...
SEVERAL WEAK UPPER LEVEL DISTURBANCES WILL BRING A CHANCE OF
THUNDERSTORMS THROUGH THE WEEKEND. HIGH PRESSURE WILL BUILD INTO
THE REGION THROUGH THE FIRST PART OF NEXT WEEK WITH TEMPERATURES
REMAINING WELL ABOVE.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MOST OF SHOWERS OVER KENTUCKY ASSOCIATED WITH WEAK LOW PRESSURE
HAVE DISSIPATED WITH LOSS OF DAYTIME HEATING. WILL HANG ON TO SOME
LOW POPS ACROSS THE SOUTH THROUGH THE OVERNIGHT HOURS THOUGH JUST
IN CASE REDEVELOPMENT OCCURS AS SUGGESTED BY THE HRRR MODEL.
EXPECT OVERNIGHT LOWS GENERALLY IN THE MID TO UPPER 50S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
THE MID/UPPER LEVEL RIDGE WILL TRY TO BUILD UP ACROSS THE AREA
THROUGH THE WEEKEND...BUT IT WILL BE TEMPERED BY SEVERAL WEAK
SHORT WAVES RIDING OVER THE RIDGE. WITH A WARM AND SEASONABLY
MOIST AIRMASS IN PLACE...THIS SHOULD BE ENOUGH TO TRIGGER AT LEAST
SCATTERED THUNDERSTORM ACTIVITY ON AND OFF SATURDAY INTO SUNDAY.
RIGHT NOW IT LOOKS LIKE THE BEST FORCING WILL MOVE ACROSS THE AREA
ON SUNDAY BUT MODELS HAVE A DIFFICULT TIME WITH THE
TIMING/STRENGTH OF THESE SHORT WAVES. WILL THEREFORE KEEP POPS IN
THE CHANCE CATEGORY THROUGH MUCH OF THE WEEKEND. DEEP LAYER SHEAR
REMAINS RELATIVELY WEAK...ALTHOUGH IT DOES BEGIN TO INCREASE A BIT
FROM THE SOUTHWEST THROUGH THE DAY ON SUNDAY. THEREFORE WOULD
THINK SEVERE THREAT WILL REMAIN RELATIVELY LOW THROUGH THE
WEEKEND. WITH FAIRLY LIGHT FLOW...LOCALLY HEAVY RAIN SHOULD BE THE
MAIN ISSUE. TEMPERATURES WILL REMAIN DEPENDENT ON AMOUNT OF CLOUD
COVER AND PCPN. WILL KEEP HIGHS MAINLY IN THE UPPER 70S...BUT IF WE
END UP WITH MORE SUN...THESE MAY BE A LITTLE LOW.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
RIDGING WILL AMPLIFY ACROSS THE REGION IN RESPONSE TO A DEEP TROUGH
MOVING SLOWLY EAST ACROSS THE ROCKIES....BRINGING INCREASING HEIGHTS
AND TEMPERATURES ALOFT FOR MONDAY AND TUESDAY. THIS WILL RESULT IN
THE WARMEST TEMPERATURES OF THE WEEK...POSSIBLY APPROACHING RECORD
VALUES. ONE INHIBITING FACTOR FOR TEMPERATURES RISING HIGHER THAN
FORECAST WILL BE THE POTENTIAL AMOUNTS OF MID AND UPPER LEVEL CLOUD
COVER...WHICH THE MODELS ARE NOT IN AGREEMENT ON AT THIS TIME.
THE TROUGH TO OUR WEST WILL CLOSE OFF INTO AN UPPER LOW AS IT SLOWLY
MOVES EASTWARD ACROSS THE PLAINS DURING THE MID WEEK. MODELS
CONTINUE TO BRING THE LOW FINALLY ACROSS THE OHIO VALLEY LATE NEXT
WEEK. THERE CONTINUE TO BE TIMING DIFFERENCES OF WHEN THIS WILL
OCCUR. HOWEVER...AS IT DOES SO...CHANCES FOR PRECIPITATION WILL
INCREASE. HAVE SPLIT THE DIFFERENCE BETWEEN THE GFS AND ECMWF IN
BRINGING BEST POPS TO THE AREA AT 00Z FRIDAY. TEMPERATURES WILL
RETURN TO MORE SEASONABLE VALUES ONCE THE LOW ARRIVES IN OUR AREA.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
ANOTHER NIGHT OF SOMEWHAT CONFLICTING MODEL GUIDANCE PUTS THE
CONFIDENCE OF THE FORECAST IN A LOW STATE. FLOW REMAINS SOUTHERLY
OVER THE OHIO VALLEY AND THE UNSEASONABLY MILD AND MOIST AIRMASS
WILL BE ABLE TO SUPPORT THUNDERSTORM DEVELOPMENT AND PROPOGATION
AT PRETTY MUCH ANY TIME...HEIGHTENED WITH THE DAYTIME HEATING. A
MEAN UPPER LEVEL RIDGE WILL HAMPER WIDESPREAD CONVECTION BUT
A SHORTWAVE OVER ILLINOIS IS PROGGED TO UNDERCUT THIS RIDGE AT
SOME POINT IN TIME THIS AFTERNOON AND EARLY EVENING.
KEPT THE VICINITY THUNDERSTORMS IN THE FORECAST THIS AFTERNOON BUT IT
WON`T BE APPARENT UNTIL THE MID LEVEL LOBE OFF OF THE MAIN
SHORTWAVE DEVELOPS TO SEE WHERE AND WHICH TAF SITES WILL PRIMARILY
BE AFFECTED.
FORECAST IS VFR ASIDE FROM SHALLOW GROUND FOG THROUGH DAYBREAK
THIS MORNING.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...CONIGLIO/JGL
SHORT TERM...JGL
LONG TERM...LATTO
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
900 PM PDT FRI MAR 16 2012
.SYNOPSIS...ANOTHER ROUND OF WIND AND RAIN FOR THE REGION TONIGHT BUT
SHOULD SEE MORE TRANQUIL BUT COOL WEATHER FOR THIS WEEKEND.
HOWEVER...AS SPRING PREPARES TO ARRIVE NEXT WEEK...OLD MAN WINTER IS
PREPPING TO GIVE SOME SERIOUS FINAL GOODBYES TO THE PAC NW...WITH
MORE RAIN...WIND...AND LOW SNOW LEVELS NEXT WEEK.
&&
.SHORT TERM...RATHER IMPRESSIVE LOW JUST OFF THE S OREGON COAST THIS
EVENING...WITH OCCLUDED FRONT BUCKLED INTO SW OREGON. RUC MODEL AND
FOR MOST PART NAM MODEL SEEM TO BE DOING BEST WITH LOW AND ITS
MOVEMENT INTO OREGON. RAIN SHIELD HEADED N BUT RAINFALL WILL BE
HEAVIEST OVER THE WILLAMETTE VALLEY WEST INTO THE COAST RANGE AS
FRONT PRECIP HEAD N ACROSS AREA THIS EVENING.
SNOW LEVELS STILL NEAR 3000 FEET. SO DESPITE PRECIP ACROSS
REGION...LOOKS THAT WILL NOT BE HEAVY ENOUGH TO COOL THE AIR MASS
DRASTICALLY. STILL...WILL SEE ACCUMULATING SNOW DOWN TO BETWEEN 1000
AND 1200 FEET IN THE N COAST RANGE AND WILLAPA HILLS. THIS
SAID...WILL MAINTAIN WINTER WEATHER ADVISORY THERE FOR 2 TO POSSIBLY
AS MUCH AS 6 INCHES OF NEW SNOW OVERNIGHT. NO SNOW ON THE COAST...AS
JUST STAYS TOO WARM.
AS FOR SNOW IN THE COLUMBIA GORGE...WELL LOOKS UNLIKELY. TEMPS ARE
STILL IN THE MID 40S IN THE GORGE...AND IN THE LOWER 50S AT THE
DALLES. WITH LACK OF ANY COLD AIR TO THE EAST...SO WILL KEEP SNOW OUT
OF THE LOWER ELEVATIONS IN THE GORGE. MAY SEE SNOW BRIEFLY DOWN TO
1000 FEET SAT AM...BUT ACCUMULATIONS LIGHT IF ANY.
OTHER CONCERN RAISED IS GUSTY WINDS. WITH TRACK OF THE LOW...BEST
GRADIENT JUMPS ARE OCCURRING OVER SW OREGON. THESE WILL TRANSLATE
ACROSS REST OF THE REGION OVERNIGHT...BUT NOT AS STRONG AS EARLIER
INDICATED. GUSTY S WINDS OF 15 TO 25 MPH...WITH GUSTS 35 TO 45 MPH
ARE LIKELY LATER THIS EVENING OVER S WILLAMETTE VALLEY INTO THE LANE
COUNTY CASCADES...THEN SPREAD NORTHWARD OVERNIGHT. HOWEVER...WINDS
WILL MUCH LESS OVER THE N AS GRADIENTS WEAKEN LATER TONIGHT. CORE OF
STRONGEST WINDS WILL REMAIN FROM FAR S LANE COUNTY UP TO SANTIAM
PASS...WITH GUSTY WINDS EXPECTED ON EAST SLOPES OF CASCADES LATER
TONIGHT AND SAT.
UNSETTLED SHOWERY WEATHER FOR SATURDAY AND SUNDAY AS THE UPPER TROUGH
PUSHES OVER THE PAC NW. BUT AT LEAST NO STRONG WINDS AND SNOW LEVELS
REMAIN IN THE MOUNTAINS WITH NO THREAT OF LOWLAND SNOW. WILL HAVE
SOME THREAT OF SMALL HAIL WITH SOME SHOWERS. SHOWERS DECREASE
SATURDAY NIGHT. COOLER AIR ARRIVES SAT NIGHT AND SUN AS THE UPPER
TROUGH PASSES INTO EASTERN OREGON...WITH SNOW LEVELS BACK DOWN
BETWEEN 700 AND 1000 FEET. HOWEVER...MOISTURE BECOMES QUITE LIMITED
SO ANY THREAT OF LOW SNOW MAY BE WELL MITIGATED. ROCKEY.
&&
.LONG TERM...FOLLOWING A WEEKEND OF MAINLY LIGHT SHOWER
ACTIVITY...THE STORM TRACK IS FCST TO MOVE BACK NORTH OVER THE PAC
NW STARTING ON TUE. FLAT RIDGING WILL REMAIN OVER THE REGION ON MON
NIGHT...BUT A SYSTEM TO THE NORTH IS FCST TO SWING A WARM FRONT INTO
THE DISTRICT LATE MON INTO TUE MORNING. EXPECT SOME GUSTY COASTAL
WINDS AND RAPIDLY RISING SNOW LEVELS AS WINDS TURN SOUTHERLY. MODEL
SOLUTIONS DIVERGE FOLLOWING THE TUE SYSTEM. THE 12Z ECMWF BRINGS
ANOTHER STRONGER SYSTEM THROUGH ON WED INTO EARLY THU. IF THIS
VERIFIES...IT LOOKS LIKE MORE HEAVY RAIN AND STRONG COASTAL WINDS.
THE 12Z GFS DIGS THE BULK OF THE ENERGY FURTHER SOUTH OF US. THE
LAST FEW RUNS OF THE ECMWF HAVE BEEN CONSISTENT WITH THIS WED
FEATURE...SO LEANED TOWARDS THIS SOLUTION FOR THE LONG TERM FCST.
HEADING INTO THE END OF THE WEEK AND NEXT WEEKEND...THE MODELS TEND
TO DIG OUT A DEEP TROUGH OVER THE ENTIRE WEST COAST. IT IS LOOKING
MUCH LIKE THE PATTERN THAT WE WILL SEE THIS WEEKEND. JFP
&&
.AVIATION...MAINLY VFR IN THE VALLEY AS THE FIRST BATCH OF RAIN
MOVES FROM SOUTH TO NORTH. PRONOUNCED DRY SLOT ON SATELLITE/RADAR
AND CONFIRMED BY OBS AT KEUG INDICATING THE PRECIP ONLY LASTS
ABOUT 3 HOURS OR SO. WE MAY SEE BRIEF MVFR WITH THE RAIN BUT NOT
FOR LONG. MVFR LOOKS TO MOVE BACK IN AS THE LOW PRES SYSTEM
ASSOCIATED WITH THE RAIN MOVES NORTH AND EAST. WE ARE STARTING TO
SEE SOME OF THAT WITH THE LOWER VFR AND HIGHER MVFR CIGS AT TIMES IN
THE CENTRAL/SOUTH VALLEY. CONDITIONS BECOME MUCH MORE UNSTABLE
LATE TONIGHT/EARLY SATURDAY...WHICH WILL BRING THE RETURN TO VFR
WITH OCCASIONAL MVFR IN ANY HEAVIER SHOWERS. EXPECT BRIEF GUSTY
SOUTHERLY WINDS LATER TONIGHT.
AT THE COAST...EXPECT A MIX OF VFR AND MVFR AT THE COAST AS
DEFORMATION PRECIP LINGERS OVERNIGHT AND THEN SHIFTS INLAND EARLY
SATURDAY. EXPECT THE HEAVIEST PRECIP RATES OVER THE COAST RANGE.
WITH SOME COLD AIR WRAPPING IN...NOT SUPER COLD...IT IS NOT OUT OF
THE QUESTION THAT SOME SNOW MAY BE MIXED IN...BUT THE CHANCE IS
VERY LOW. LATEST 0Z COBB OUTPUT (TOP-DOWN METHODOLOGY FOR PRECIP
TYPE) HAS BEEN BACKING OFF ON ANY SNOW MIXING IN AT KAST. THEN A
RETURN TO SHOWERS AND MVFR AT TIMES. POSSIBLY A THUNDERSTORM IN
THE UNSTABLE AIR MASS.
KPDX AND APPROACHES...VFR CONDITIONS PREVAIL THROUGH TONIGHT. MVFR
CIGS ARE POSSIBLE TONIGHT AS SHOWERS GRADUALLY INCREASE. EXPECT
WINDS TO PICK UP AFTER 09Z...WITH GUSTS NEAR 25 KTS LATE
TONIGHT/EARLY SAT MORNING. SHOWERS WITH VFR AND OCCASIONAL MVFR ON
SATURDAY.
&&
.MARINE...WINDS ARE FAIRLY LIGHT OVER WATERS NOW...THOUGH EXPECT
NORTHERLY SMALL CRAFT CRITERIA GUSTS NEAR 25 KTS TONIGHT WITH A
FEW GUSTS NEAR 30 KTS DURING THE 6Z TO 12 Z PERIOD AS A STRONG BUT
WEAKENING SURFACE LOW PUSHES INLAND. EXPECT LITTLE CHANGE IN SEAS
THROUGH SAT...WITH SEAS REMAINING AROUND 12 TO 13 FT. WINDS REMAIN
BELOW 20 KT FOR THE REST OF THE WEEKEND WITH WEAK HIGH PRES IN
PLACE. ANOTHER ROUND OF GALES IS POSSIBLE MONDAY NIGHT AS A STRONG
WARM FRONT MOVES THROUGH WITH A STRONG SURFACE LOW WELL TO THE
NORTH.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 6 AM PDT SATURDAY FOR CENTRAL WILLAMETTE
VALLEY-SOUTH WILLAMETTE VALLEY.
WINTER WEATHER ADVISORY UNTIL 9 AM PDT SATURDAY FOR COAST
RANGE OF NORTHWEST OREGON.
WA...WINTER WEATHER ADVISORY UNTIL 9 AM PDT SATURDAY FOR WILLAPA
HILLS.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 2 PM PDT SATURDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 PM PDT SUNDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 AM PDT SATURDAY FOR
COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 5 PM
PDT SATURDAY.
&&
$$
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 LUBBOCK TX
1143 PM CDT FRI MAR 16 2012
.UPDATE...
HAVE UPDATED GRIDS REDUCING POPS AND ADDING MENTION OF AREAS OF
FOG PRIMARILY WEST OF A CHILDRESS TO POST LINE AS MOIST AIR
STREAMS INTO THE REGION ONCE AGAIN. IT IS POSSIBLE THAT IF THE
WINDS CONTINUE TO DIMINISH AS IS EVIDENT ACROSS THE
SOUTHEAST......PARTICULARLY ACROSS THE LLANO
ESTACADO...DENSE FOG WILL BE POSSIBLE.
&&
.AVIATION...
FOG WILL BE PRIMARY CONCERN AND IFR TO LIFR CONDITIONS ARE
CERTAINLY POSSIBLE AT BOTH SITES THIS MORNING. LOW LEVEL MOISTURE
CONTINUES TO STREAM IN UNDER CLEARING SKIES. IF DECOUPLING OF LLJ
CAN INCREASE WITH THE NEAR-SURFACE INVERSION SETTING
UP...CONDITIONS COULD DETERIORATE RAPIDLY.
&&
PREV DISCUSSION... /ISSUED 358 PM CDT FRI MAR 16 2012/
SHORT TERM...
THE FORECAST AND SEVERE WEATHER PARAMETERS ARE PROGRESSING AS
EXPECTED FROM THIS MORNINGS UPDATE. LATEST RUC ANALYSIS INDICATES
3500 J/KG OF SURFACE INSTABILITY NOSING INTO THE AREA WITH AREAS
OF HIGH THETA-E AIR AND NO SURFACE BASED CIN. DEEP LAYER SHEAR
CONTINUES TO INCREASE OVER THE AREA WITH ABOUT 30KT OBSERVED.
ADDITIONALLY...A LARGE AREA OF ACCAS HAS BEEN OBSERVED SOUTH AND
SOUTHWEST OF THE LUBBOCK AREA. WILL CONTINUE TO EXPECT AN
INITIATION TIME AFTER 21Z. THE PRIMARY SEVERE THREAT REMAINS AS
LARGE HAIL AND DAMAGING WINDS. DESPITE SUPERCELLULAR STRUCTURE
EXPECTED WITH STORMS...TORNADOES ARE NOT AS LIKELY DUE TO THE VERY
WEAK LOW LEVEL SHEAR.
FOG IS AGAIN EXPECTED TONIGHT AND COULD BECOME DENSE AGAIN ON THE
CAPROCK. THE DRYLINE IS EXPECTED TO MIX FURTHER EAST SATURDAY
AFTERNOON. THE CAP IS PROGGED TO BE NEARLY ZERO OFF THE CAPROCK
WITH VERY STRONG SURFACED BASED CAPE IN EXCESS OF 3 KJ/KG.
HOWEVER...THERE WILL BE A LACK OF LARGE SCALE LIFT TOMORROW
AFTERNOON WITH ONLY WEAK LOW LEVEL CONVERGENCE ALONG THE DRYLINE.
WILL KEEP THE SLIGHT CHANCE GOING FOR SATURDAY AFTERNOON GIVEN
THESE PARAMETERS IN PLACE. JDV
LONG TERM...
ANOTHER WEAK DISTURBANCE LOOKS TO MOVE OVER THE AREA SATURDAY
NIGHT INTO EARLY SUNDAY MORNING BUT POINT SOUNDINGS SHOW A PRETTY
STRONG CAP IN PLACE THAT MAY LIMIT STORM CHANCES SOMEWHAT. CHANCES
FOR STORMS...A FEW ONCE AGAIN POSSIBLY SEVERE...LOOKS TO BE BETTER
SUNDAY NIGHT INTO MONDAY MORNING AS A COMBINATION OF THE APPROACH
OF THE MAIN LOW...INCREASING DEEP LAYER SHEAR AND CURVED LOW-LEVEL
HODOGRAPH...AND INCREASING MOISTURE IN THE LOWER ATMOSPHERE THANKS
TO A LOW-LEVEL JET ALL CONTRIBUTE TO DECENT INSTABILITY LEVELS.
DID INCREASE POPS FOR SUNDAY NIGHT THROUGH MONDAY MORNING AS THE
DRYLINE/PACIFIC FRONT HELPS TO FOCUS SURFACE CONVERGENCE AND THEN
CLEAR PRECIPITATION OUT FROM WEST TO EAST THROUGH THE MORNING.
OTHER CONCERN WITH THE SYSTEM AS IT MOVES OUT ACROSS THE AREA WILL
BE FIRE WEATHER FOR MONDAY. SEE FIRE WEATHER DISCUSSION SECTION
FOR MORE DETAILS. DRY AIR WILL RAPIDLY SWEEP IN ON A BREEZY TO
WINDY WESTERLY WIND DURING THE DAY MONDAY. MODELS HAVE COME INTO
BETTER AGREEMENT ON DEVELOPING THE TROF INTO A CLOSED LOW AND
TAKING IT FURTHER EAST RATHER THAN PREVIOUS RUNS KEEPING IT CLOSER
TO THE FORECAST AREA. FORECAST PARAMETERS WILL DEPEND ON WHETHER
WE WILL HAVE WEAK SHORTWAVE RIDGING OR ZONAL FLOW ACROSS THE AREA.
DRY AIR WILL SLOWLY MODIFY AT THE SURFACE THROUGH THE END OF NEXT
WEEK WHICH WILL KEEP THE FORECAST DRY. HOWEVER...FOCUS IS ON
SEVERE WEATHER POTENTIAL FOR THE NEXT SEVERAL DAYS SO MOST OF THE
EXTENDED FORECAST WAS NOT CHANGED.
JORDAN
FIRE WEATHER...
ELEVATED TO LOW END CRITICAL FIRE WEATHER CONDITIONS WILL BE
LIKELY SATURDAY AFTERNOON ACROSS THE WESTERN SOUTH PLAINS. A
SURFACE TROUGH WILL STRENGTHEN SATURDAY AFTERNOON LEADING TO GUSTY
SOUTHWEST WINDS ON THE WEST SIDE OF A DRYLINE. THIS DRYLINE WILL
MOVE TO THE EDGE OF THE CAPROCK TOMORROW AFTERNOON WITH VERY DRY
AIR TO THE WEST OF THIS FEATURE. GUSTY WINDS COMBINED WITH VERY
WARM TEMPERATURES WILL LEAD TO THE ELEVATED OR LOW END CRITICAL
FIRE WEATHER CONDITIONS. ANOTHER MORE WIDESPREAD FIRE WEATHER
EVENT WILL BE POSSIBLE ON SUNDAY AS STRONG WESTERLY WINDS AND DRY
AIR PUSH INTO THE REGION BEHIND A DEPARTING STORM SYSTEM.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 46 84 52 81 46 / 0 0 0 20 30
TULIA 53 83 58 80 49 / 10 10 20 30 40
PLAINVIEW 51 82 58 81 50 / 10 10 20 30 50
LEVELLAND 51 82 59 82 50 / 0 10 10 30 40
LUBBOCK 54 83 60 81 53 / 10 10 20 30 50
DENVER CITY 52 82 56 84 50 / 0 10 10 20 40
BROWNFIELD 53 83 60 83 51 / 0 10 20 30 40
CHILDRESS 57 84 62 80 60 / 10 20 20 30 60
SPUR 55 83 61 80 58 / 10 20 20 30 50
ASPERMONT 59 80 64 79 59 / 10 20 20 30 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR THE FOLLOWING ZONES:
TXZ021>023-027-028-033-034-039-040.
&&
$$
99/99/26
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
129 AM EDT SAT MAR 17 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL MAINTAIN A MOIST
SOUTHWEST FLOW OF AIR ACROSS THE REGION. WEAK UPPER LEVEL IMPULSES
WILL PASS FROM THE OHIO VALLEY ACROSS THE MID ATLANTIC REGION
HELPING TO TRIGGER SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS.
A COLD FRONT WILL MOVE SOUTH THROUGH THE MID ATLANTIC STATES
TONIGHT AND SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 931 PM EDT FRIDAY...
SHOWERS ARE JUST ABOUT OUT OF THE NW PIEDMONT OF NC. ANOTHER AREA
OF SHRA/TSRA MOVING ACROSS E TN INTO WRN NC JUST SOUTH OF THE NC
MTNS. LATEST HRRR AND LOCAL WRF TAKE THIS BATCH OF SHOWERS INTO
THE MTNS OF NC AND FOOTHILLS THROUGH EARLY OVERNIGHT. WEAKENING
TREND WITH LOSS OF HEATING WILL LEAD TO ONLY ISOLATED TSRA. WILL
KEEP HIGHER POPS IN THE SOUTH...WITH LESS TO NONE IN THE NRN CWA.
FOG WILL ALSO FORM TONIGHT AS THE GROUND/LOW LVLS STAY MOIST.
BACKDOOR FRONT OVER NRN/ERN VA WILL SLIDE SW TOWARD THE AREA BY
EARLY MORNING...ALTHOUGH MODELS KEEP STABLE LAYER ACROSS THE
PIEDMONT NE OF LYH THROUGH DAWN. EXPECT TO SEE TEMPS DROP TOWARD
THE UPPER 40S IN THE NW/N AND ALONG THE MTNS OF NC LATE...WITH 50S ELSEWHERE.
TEMPERATURES TRICKY FOR TOMORROW. EASTERLY FLOW SHOULD KEEP
TEMPERATURES ALONG AND EAST OF THE BLUE RIDGE COOL AND BELOW
GUIDANCE. THAT IS...IF THE AREA CAN MAINTAIN CLOUD COVER. DEW
POINTS BEHIND THE BOUNDARY ARE STILL MUGGY AND IN THE UPPER 40S TO
MID 50S. THEREFORE...IT LOOKS AS IF THE CLOUDS WILL REMAIN THROUGH
MOST OF TOMORROW. THE UPPER LEVEL TROUGH AND ASSOCIATED SHORT
WAVES SHOULD ALSO HELP MAINTAIN CLOUD COVER AND PROVIDE RAIN IN
THE AFTERNOON. DID WARM TEMPERATURES UP FROM PREVIOUS FORECAST BUT
KEPT IT COOLER THAN GUIDANCE ALONG AND EAST OF THE BLUE RIDGE.
DOWNSLOPING FLOW WILL HELP THE WESTERN SLOPES WARM ABOVE
NORMAL...ESPECIALLY AS RAIN PULLS OUT BY AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 310 PM EDT FRIDAY...
FORECAST WILL BE DOMINATED BY SUB-SYNOPTIC SCALE PHENOMENA
SUNDAY-MONDAY AS SEVERAL SHORT-WAVES TRANSIT THROUGH THE BROAD UPPER
RIDGE LOCATED OVER THE EASTERN STATES. EXPECT THIS ENERGY TO
INTERACT WITH A MOIST AND FAIRLY UNSTABLE AIR MASS TO BRING CHANCES
FOR SHOWERS AND A FEW THUNDERSTORMS THROUGH MUCH OF THE PERIOD. WENT
MAINLY WITH DIURNAL/TERRAIN DRIVEN POP TRENDS WITH HIGHEST IN THE
MOUNTAINS AND IN THE AFTERNOON. TEMPS WILL REMAIN VERY WARM AS
HEIGHTS/THICKNESSES CONTINUE IN THE LATE SPRING/EARLY SUMMER
PATTERN THAT HAS BROUGHT WIDESPREAD RECORD WARMTH TO MUCH OF THE
EASTERN CONUS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 250 PM EDT THURSDAY...
EXTENDED FORECAST IS LITTLE CHANGED IN THE OVERALL SYNOPTIC PATTERN
WITH THE DEEP WESTERN TROUGH AND STRONG UPPER RIDGE STILL DOMINANT
OVER THE CONUS. THE TENDENCY IS FOR THE TROUGH TO EDGE EASTWARD AS
THE WEEK PROGRESSES. GFS ENSEMBLES SHOW VERY LITTLE SPREAD IN THE H5
HEIGHT FIELD INTO WEDNESDAY WITH INCREASING SPREAD AMONG THE MEMBERS
AS NORTHERN STREAM ENERGY EVENTUALLY BEGINS TO CARVE OUT A CLOSED
LOW OVER THE WESTERN PLAINS BY LATE WED/THU WHICH IS THEN EJECTED
SLOWLY EASTWARD REACHING THE OH VALLEY BY AROUND FRIDAY DEPENDING ON
YOUR MODEL OF CHOICE. THE MID-WEEK PERIOD WILL BE CHARACTERIZED BY A
SCATTERED DIURNAL SHOWER REGIME DRIVEN BY WEAK SHORT-WAVES AND
PROBABLE OUTFLOW BOUNDARIES. AGAIN DIFFICULT TO PINPOINT COHERENT
SPATIAL/TEMPORAL COVERAGE PATTERN OTHER THAN HIGHER LIKELIHOOD OF
TYPICAL MOUNTAIN AND AFTERNOON TO EARLY EVENING ENHANCEMENT OF POPS.
INCREASING DEEP LAYER SOUTHERLY FLOW AHEAD OF THE ADVANCING UPPER
LOW SYSTEM WILL BRING INCREASED CHANCES FOR MORE ORGANIZED
PRECIPITATION LATE IN THE WEEK. TEMPS REMAINING IN THE WELL ABOVE
NORMAL (FOR MID-MARCH) RANGE THROUGHOUT THE WEEK RUNNING AT LEAST 10
TO 15F OVER SEASONAL NORMS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 115 AM EST SATURDAY...
STILL SEEING ISOLATED -SHRA IN SPOTS OVER THE SOUTH AND WEST BUT
MAINLY STILL VFR WITH MOSTLY MID DECK AROUND. HOWEVER WITH A HIGH
LEVEL OF MOISTURE ON THE GROUND...AND SOME CLEARING ALONG WITH A
BACK DOOR FRONT ARRIVING LATE...MAY SEE SOME FOG DEVELOPMENT AS
WELL AS LOW STRATUS. THIS IS THE MAIN AVIATION ISSUE INTO SAT
MORNING...AND FORECAST CONFIDENCE IS MODERATE ON WHICH WILL BE
MORE IMPACTED. ATTM...WILL LEAN TOWARD MORE FOG AS THINK ENOUGH
CLOUD COVER FROM AC/CS WILL KEEP STRATUS FROM FORMING BUT DID BEEF
UP FOG MENTION AT KDAN OVERNIGHT. THE FOG STABILITY OFF THE
SOUNDINGS SUGGEST BETTER FOG THREAT.
WITH THIS IN MIND WILL HAVE ROA/LYH/DAN DROP TO MVFR VSBYS FROM
08Z UNTIL 13Z. LYH COULD SEE SOME STRATUS...BUT NOT ENOUGH
CONFIDENCE FOR ADDING IT.
IN THE MTNS THINK BLF/LWB/BCB WILL SEE BETTER FOG THREAT ALTHOUGH
SOME MORE CLOUDINESS ARRIVING LATE COULD SEND VSBYS BACK UP AROUND
10-12Z. FOR NOW WILL BE BRING CIGS DOWN TO IFR OR LOWER AT BLF/LWB
WITH SCT LOWER CLOUDS IN BCB. VSBYS WILL DROP TO 1 TO 4SM.
THE FOG/LOWER CLOUDS WILL BE ERODING BY MID MORNING WITH THE FLOW
VARYING FROM NE IN THE LYH AREA TO SOUTH IN THE FAR WEST. ANOTHER
SHORTWAVE MOVES ACROSS SATURDAY INTERACTING WITH SFC BOUNDARY TO
SPARK ANOTHER ROUND OF SHOWERS/TSRA. ATTM...THE FAVORED AREAS WILL
BE SOUTH OF A LWB-ROA-DAN LINE...AND WILL ADD SHRA OR VCSH/CB INTO
BLF/BCB AND PERAHPS KROA FOR NOW. WILL SEE VFR CONDITIONS AFTER
LATE MORNING AT ALL SITES.
AN EASTERLY FLOW LOOKS TO PERSIST INTO SUNDAY. THIS MAY BRING SUB-
VFR CONDITIONS TO THE AREA IF THE AIR MASS IS ABLE TO BECOME
SATURATED IN THE BOUNDARY LAYER FROM EASTERLY UPSLOPE FLOW.
SCATTERED AFTERNOON SHOWERS AND STORMS MAY ALSO OCCUR ESPCLY
ALONG/WEST OF THE BLUE RIDGE WITH MVFR OR WORSE CONDITIONS NEAR
ANY CONVECTION. STRONG HIGH PRESSURE WILL BUILD ACROSS THE REGION
EARLY NEXT WEEK RESULTING IN WIDESPREAD VFR OUTSIDE OF ISOLATED
MAINLY AFTERNOON MOUNTAIN SHOWERS MONDAY THRU WEDNESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RCS/WP
NEAR TERM...RCS/WP
SHORT TERM...PC
LONG TERM...PC
AVIATION...JH/RCS/WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
350 AM CDT SAT MAR 17 2012
.SHORT TERM...TODAY THROUGH SUNDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE WARM
FRONT LIFTING NORTHWARD OVER CENTRAL WISCONSIN EARLY THIS MORNING.
TEMPS ARE IN THE LOW TO MID 50S NORTH OF THE FRONT...AND IN THE MID
TO UPPER 60S SOUTH OF THE BOUNDARY. TEMPS ARE LOCALLY COOLER NEAR
LAKE MICHIGAN WITH SOME OF THAT MARINE AIR CURLING AROUND INTO
SHAWANO WHERE TEMPS ARE IN THE LOWER 40S WITHIN DENSE FOG. WIDELY
SCT SHOWERS AND THUNDERSTORMS THAT DEVELOPED OVER NORTH-CENTRAL
WISCONSIN HAVE BEEN WEAKENING AND WILL LIKELY EXIT THE AREA BY PRESS
TIME. ADDITIONAL ECHOES HAVE POPPED UP WITHIN THE INSTABILITY AXIS
OVER SW WISCONSIN AND NORTHWEST ILLINOIS...AND WILL ADD ISOLATED
SHOWERS AND THUNDERSTORMS NEARLY EVERYWHERE THROUGH MID-MORNING.
WITH VERY WARM AND UNSTABLE AIR MOVING INTO THE REGION TODAY...SMALL
PRECIP CHANCES ARE THE MAIN FORECAST CONCERN...FOLLOWED BY TEMPS AND
MARINE FOG.
TODAY...SURFACE WARM FRONT...WHICH SNAKES ACROSS WISCONSIN FROM NW
TO SE...WILL LIFT NORTH OF THE AREA THIS MORNING...WHICH WILL TURN
WINDS TO THE SOUTH EXCEPT ACROSS FAR NE WISCONSIN. SE WINDS
HERE...ENHANCED BY THE LAKE BREEZE THIS AFTERNOON...WILL KEEP WAVES
OF MARINE STRATUS AND FOG PROCEEDING INLAND AT TIMES.
OTHERWISE...850MB MOISTURE AND INSTABILITY AXIS WILL BE OVERHEAD
TODAY...WITH ML CAPES REACHING CLOSE TO 2500 J/KG WITH NO CIN THIS
AFTERNOON. TOUGH TO IDENTIFY A TRIGGER UPSTREAM THAT COULD TAP INTO
THIS INSTABILITY FOR THUNDERSTORM DEVELOPMENT...AND MAY JUST END UP
WITH BUBBLY CU...WHICH OCCURRED UPSTREAM TODAY. THERE ARE A COUPLE
WEAK IMPULSES UPSTREAM...OVER NW IOWA AND ANOTHER OVER WESTERN
NEBRASKA...BUT TOUGH TO SAY IF THEY WILL BE STRONG ENOUGH TO TRIGGER
CONVECTION. THE BEST THING TO LATCH ONTO IS THE SE FLOW OVER THE
DOOR...WHICH COULD GET ENHANCED BY THE LAKE BREEZE COMPONENT TO
CREATE CONVERGENCE OVER NE WISCONSIN. SYNOPTIC FLOW WILL BE OUT OF
THE SOUTH...NOT OUT OF THE SOUTHWEST OR WEST WHICH WOULD BE MORE
PREFERRED. STILL THOUGH...THAT MAGNITUDE OF CAPE CANNOT BE IGNORED
SO WILL KEEP AN ISOLATED MENTION OF SHOWERS AND THUNDERSTORMS OVER
NE WISCONSIN FOR THIS AFTERNOON. 925MB TEMPS 18C TO 20C CALL FOR
HIGHS IN THE UPPER 70S TO LOWER 80S.
TONIGHT...850MB MOISTURE AND INSTABILITY AXIS WILL REMAIN OVERHEAD.
LLJ WILL DEVELOP OVER WESTERN WISCONSIN WITH A NOSE POINTED INTO
LAKE SUPERIOR. ANY KIND OF WEAK SHORTWAVE IMPULSE COULD INITIATE
CONVECTION WITH MID-LEVEL LAPSE RATES GREATER THAN 8C...BUT TOUGH TO
IDENTIFY ANY FEATURES ON SATELLITE OR IN THE MODELS. IF SOMETHING
WERE TO POP...WESTERN WISCONSIN LOOKS BETTER ON PAPER. BUT
UNCERTAINTY IS TOO HIGH TO INCLUDE IN THE FORECAST.
OTHERWISE...SOUTH FLOW WILL AGAIN SEND WAVES OF MARINE STRATUS AND
FOG NORTH ALONG THE LAKESHORE AND ACROSS DOOR COUNTY AND FAR NE
WISCONSIN. A WARM NIGHT AHEAD WITH LOWS IN THE MID TO UPPER 50S.
SUNDAY...SHORTWAVE ENERGY WILL PASS SOUTH OF THE AREA WHILE
MID-LEVEL HEIGHTS BUILD OVERHEAD. AS A RESULT...SEEING STRONGER
CAPPING ON PROGGED SOUNDINGS WHICH SHOULD KEEP A LID ON SHOWER AND
THUNDERSTORM DEVELOPMENT. WILL GO DRY ONCE AGAIN. HIGHS AGAIN IN
THE UPPER 70S TO LOWER 80S...BUT COOLER NEAR LAKE MICHIGAN WHERE THE
ONSHORE COMPONENT WILL BE A LITTLE STRONGER.
.LONG TERM...SUNDAY NIGHT THRU FRIDAY. MAIN FORECAST CHALLENGES
ARE TEMPS...PRECIP CHANCES...AND FOG POTENTIAL.
SUMMER-LIKE PATTERN CONTINUES INTO EARLY NEXT WEEK AS UPPER RIDGE
BUILDS ACROSS THE EASTERN U.S. AND SOUTHERLY FLOW USHERS IN WARM
AIR AND RELATIVELY HIGH DEWPOINTS. TROUGH ACROSS THE WESTERN U.S.
WILL CROSS INTO THE PLAINS ON WEDNESDAY...AND TRANSITION INTO A
CUT OFF LOW THAT SLOWLY MOVES SOUTH OF THE GREAT LAKES LATE NEXT
WEEK. MODELS DISAGREE ON THE EVOLUTION FROM A LONGWAVE TROUGH TO
A CUT OFF LOW...BOTH WITH LOCATION AND TIMING...BRINGING PLENTY OF
UNCERTAINTY INTO THE FORECAST. IN GENERAL...PLAN TO FOLLOW A
GFS/ECMWF BLEND.
SUNDAY NIGHT IS STILL LOOKING DRY...AS THE AREA REMAINS UNDER
UPPER RIDGING AND NO OBVIOUS TRIGGER FOR CONVECTION. CANNOT
TOTALLY RULE OUT A STRAY SHOWER OR STORM AS STEEP LAPSE RATES
REMAIN OVER THE AREA...BUT PREFER TO STAY WITH A DRY FORECAST.
CLOUDS WILL BE ON THE INCREASE OVERNIGHT AND ON MONDAY MORNING
THOUGH...AS MOISTURE INCREASES ALOFT. WILL START TO INCREASE
POPS ON MONDAY AND MONDAY NIGHT OVER THE AREA AS UPPER TROUGH AND
SHORTWAVE ENERGY APPROACH THE AREA. STILL BELIEVE THE MAJORITY OF
THE ACTIVITY WILL STAY TO OUR WEST...WHERE THE BETTER
MOISTURE/FORCING AND BAROCLINIC ZONE IS LOCATED...BUT WILL CARRY
LOW CHANCE POPS OVER CENTRAL AND NORTH-CENTRAL WI...WITH SLIGHT
CHANCE POPS BUFFERING THIS AREA TO THE EAST. THE EXTENDED DRY
SPELL (AT LEAST FOR MOST LOCATIONS) WILL COME TO AN END TUESDAY OR
WEDNESDAY...AS THE UPPER TROUGH AND A NORTHERN PLAINS SHORTWAVE
CONVERGE ON THE AREA. POPS WILL NEED TO BE ADJUSTED FOR TUESDAY AS
THE TIMING IS PINNED DOWN...BUT PLAN TO STICK WITH CHANCE POPS
WEST AND SLIGHTS EAST TO COVER FOR NOW. HIGHEST POPS WILL BE
PLACED ON WEDNESDAY...AS THERE IS ENOUGH MODEL CONSENSUS SHOWING
PRECIP OVER THE AREA. THE UNSETTLED WEATHER LOOKS TO CONTINUE INTO
THE END OF THE WEEK AS THE UPPER LOW DRIFTS SOUTH OF THE
AREA...HOWEVER CONFIDENCE IS LOW ON THE OVERALL PATTERN. WITH
MODELS DIFFERING ON THE TIMING AND LOCATION OF THE CUT OFF
LOW...AS WELL AS A POSSIBLE SHORTWAVE OVER THE NORTHERN
PLAINS...IT WILL BE HARD TO SAY WITH CONFIDENCE WHERE THE BEST
CHANCES FOR PRECIP RESIDE AND WHEN TO GO DRY. HAVE LOW CHANCE AND
SLIGHT POPS TO COVER THIS UNCERTAINTY. DOWNPLAYED THUNDER
POTENTIAL FOR MANY OF THE PERIODS...ESPECIALLY AT NIGHT...AS
CONVECTIVE PARAMETERS ARE NOT OVERLY IMPRESSIVE.
AS FOR FOG...WILL CONTINUE TO HIGHLIGHT ON LAKE MICHIGAN AND MUCH
OF THE BAY THROUGH MID-WEEK AS UNSEASONABLY HIGH DEWPOINTS TRAVEL
ACROSS THE RELATIVELY COOLER WATERS. WILL ALSO MENTION FOG ALONG
THE IMMEDIATE SHORELINE AS ANY FOG BANK THAT DEVELOPS COULD DRIFT
INLAND. WITH DEWPOINTS IN THE 50S TO NEAR 60 THROUGH MID-
WEEK...DO EXPECT PATCHY FOG ELSEWHERE SOME NIGHTS IF WINDS CAN
DECOUPLE AND SKIES ARE CLEAR. BEST CHANCE FOR THIS WILL BE SUNDAY
NIGHT...SO WILL CONTINUE TO MENTION FOG ACROSS THE ENTIRE CWA.
WINDS LOOK TO STAY UP THE REST OF THE NIGHTS TO KEEP THE THREAT OF
FOG LOW.
RECORD OR NEAR RECORD WARMTH WILL CONTINUE ON MONDAY AND
TUESDAY AS PERSISTENT SOUTHERLY FLOW CONTINUES TO USHER IN WELL
ABOVE NORMAL TEMPS. TUESDAY LOOKS TO BE THE LAST DAY IN THE 70S
FOR PORTIONS OF CENTRAL AND EAST-CENTRAL WISCONSIN...BEFORE THE
CLOUDS AND PRECIP HOLD TEMPS IN THE MID/UPPER 50S NORTH AND LOW
60S SOUTH FOR THE END OF THE WORK WEEK. THESE MAY BE A LITTLE
GENEROUS IF PRECIP/CLOUD COVER ARE WIDESPREAD ENOUGH. ALTHOUGH
TEMPS WILL BE SIGNIFICANTLY COOLER LATE IN THE WEEK COMPARED TO
EARLY IN THE WEEK...THEY WILL REMAIN ABOVE NORMAL.
&&
.AVIATION...ISOLD CONVECTION WILL BE PASSING OVER NORTHERN
WISCONSIN OVERNIGHT. OTHERWISE AFTER SOME PATCHY MVFR VSBYS DUE
TO FOG...MAINLY VFR CONDITIONS EXPECTED SATURDAY.
TDH
&&
.MARINE...AREAS OF DENSE MARINE FOG SEEM MOST CONCENTRATED ADJACENT
TO THE DOOR PENINSULA...AND THE CENTRAL AND NORTHERN PORTIONS OF
GREEN BAY. WITH COORD FROM MKX...WILL CANCEL THE MARINE DENSE FOG
ADVISORY FOR AREAS SOUTH OF THE DOOR. WILL LEAVE A MENTION OF
PATCHY DENSE FOG THROUGH SUNDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/BERSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
310 AM CDT SAT MAR 17 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
310 AM CDT SAT MAR 17 2012
MAIN FORECAST CONCERNS ARE ON ANY CHANCES FOR PRECIPITATION THROUGH
SUNDAY NIGHT...WINDS AND THE UNPRECEDENTED WARMTH.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT
ANALYSIS SHOWED DEEP TROUGHING JUST OFF THE CALIFORNIA COAST WHILE
BROAD RIDGING WAS BUILDING DOWNSTREAM OVER THE EASTERN TWO THIRDS
OF THE U.S.. RIDGE AXIS SITS OVER THE GREAT LAKES...PLACING THE
FORECAST AREA UNDER SOUTHWEST FLOW. WITHIN THIS SOUTHWEST FLOW...A
WEAK SHORTWAVE COMBINED WITH A WARM FRONTAL BOUNDARY AND
INCREASING LOW LEVEL JET TO PRODUCE A CLUSTER OF STRONG TO SEVERE
SHOWERS AND THUNDERSTORMS LAST EVENING OVER CENTRAL WISCONSIN.
THESE HAVE SINCE LIFTED INTO UPPER MICHIGAN THANKS TO THE
SHORTWAVE MOVING NORTHEAST AND A 30-40 KT SOUTHWEST JET AT 850MB.
WITHIN THIS SOUTHWEST FLOW...THE ONLY SHORTWAVES OF NOTE ARE WEAK
ONES IN NEBRASKA...AND THESE ARE NOT PRODUCING MUCH CLOUDS AT ALL.
WITH THE FORECAST AREA UNDER THAT STRONG SOUTHWEST JET AND A
RELATIVELY TIGHT PRESSURE GRADIENT AT THE SURFACE AHEAD OF A
TROUGH IN THE DAKOTAS... TEMPERATURES HAVE STRUGGLED TO FALL.
READINGS ARE ONLY IN THE 60S. DEWPOINTS ARE ALSO STAYING UP IN THE
MID TO UPPER 50S. AIRMASS IS ALSO SEMI-CAPPED AND DRY...LOOKING AT
THE 00Z DVN SOUNDING. GOING FARTHER SOUTHWEST TO OAX AND IT DRIES
OUT EVEN MORE. DESPITE THE DRIER AIR...THERE IS ENOUGH INSTABILITY
WHEN LIFTED FROM 800MB /APPROX 700 J/KG/ TO PRODUCE PRECIPITATION.
A ZONE OF 800MB SPEED CONVERGENCE IN SOUTHWEST WISCONSIN AND
NORTHWEST ILLINOIS HAS PRODUCED SOME SHOWERS DOWN THERE.
TODAY THROUGH SUNDAY NIGHT...UPPER TROUGHING APPROACHING THE WEST
COAST OF THE U.S. RIGHT NOW IS PROGGED BY ALL MODELS TO MOVE INTO
THE ROCKIES BY 12Z MONDAY. A FAIRLY DEEP LOW PRESSURE SYSTEM ENDS UP
DEVELOPING OVER EASTERN MONTANA AS THIS TROUGH MOVES EAST...ALLOWING
FOR STRONG SOUTHERLY FLOW TO PERSIST DOWNSTREAM INTO OUR FORECAST
AREA. A COUPLE OF IMPACTS FROM THIS STRONG SOUTHERLY FLOW INCLUDE:
1. HELPING TO MAINTAIN THE UNSEASONABLY HIGH DEWPOINTS...WHICH COULD
EXCEED 60F AT TIMES BETWEEN 15-18Z BEFORE DROPPING DUE TO MIXING.
2. MAINTAIN THE UNSEASONABLY WARM 925 AND 850MB TEMPS...WHICH ARE
PROGGED TO STAY BETWEEN 16-20C AND 12-14C RESPECTIVELY. THESE
READINGS ARE VERY SIMILAR TO WHAT WAS SEEN FRIDAY...SO HIGH
TEMPERATURES BOTH TODAY AND SUNDAY ARE LIKELY TO BE SIMILAR. SOME
HINTS FROM MET GUIDANCE WHICH DID WELL YESTERDAY THAT SITES SUCH AS
BOSCOBEL COULD HIT THE MID 80S. GENERALLY FOLLOWED THIS.
3. A LOT OF GUSTY WINDS THROUGHOUT. APPEARS THAT WHEN LOOKING AT
SOUNDINGS...MIXING DEPTHS AT MOST APPROACH 850MB. MOMENTUM TRANSFER
FROM THIS LEVEL KEEPS WINDS BELOW ADVISORY CRITERIA...EVEN AT RST.
4. RESULTING FROM ITEMS 1-3 ABOVE...LOW TEMPERATURES ARE GOING TO
STAY VERY WARM FOR THIS TIME OF YEAR...LIKELY STRUGGLING TO GET MUCH
BELOW 60.
REGARDING PRECIPITATION...TRIGGERS ARE VERY HARD TO FIND THROUGH
SUNDAY NIGHT. IN ADDITION...THE AIRMASS LOOKS A LITTLE MORE CAPPED
PER RUC/GFS SOUNDINGS. WE DO HAVE THE WEAK SHORTWAVES IN NEBRASKA
COMING ACROSS THE FORECAST AREA AT 18Z TODAY...BUT THERE IS NO
SURFACE CONVERGENT FEATURE LIKE YESTERDAY WITH THE WARM FRONT. IN
FACT...NO SURFACE CONVERGENT FEATURES ARE PRESENT THROUGH SUNDAY
NIGHT. AFTER 06Z SUNDAY NIGHT...THERE ARE INDICATIONS OF A
SHORTWAVE COMING ACROSS SOUTHEAST MINNESOTA...AS WELL AS
ISENTROPIC LIFT ON THE 305-310 K SURFACES. THE 17.00Z GFS/CANADIAN
BOTH HINT AT POTENTIAL FOR SOME CONVECTION IN THIS AREA...SO
INCLUDED SOME 20 PERCENT CHANCES FOR NOW...GIVEN NAM/UKMET/ECMWF
DRY. FOR THE REST OF THE PERIOD...ALL MODELS ARE PRETTY MUCH DRY
THROUGH SUNDAY WHICH SEEMS REASONABLE.
MONDAY AND MONDAY NIGHT...THE UPPER TROUGHING OVER THE ROCKIES IS
FORECAST TO INCH EASTWARD...WITH ITS AXIS FROM EASTERN MONTANA INTO
NEW MEXICO AT 12Z TUESDAY. ALTHOUGH THIS TROUGH IS FAR AWAY FROM THE
AREA...WE WILL SEE 10-30 METER 500MB HEIGHT FALLS EACH 12 HOUR
PERIOD OVER THE FORECAST AREA...HIGHEST WEST. THESE HEIGHT FALLS
COMBINED WITH STRONG MOISTURE TRANSPORT ON A SOUTHERLY 40-60 KT
850MB JET WILL YIELD INCREASING PRECIPITATION CHANCES...ESPECIALLY
AGAIN OVER THE WEST. PRECIPITABLE WATER VALUES CLIMB TO 1-1.4 INCHES
WHICH WOULD SUPPORT SOME DECENT PRECIPITATION TOO. CAPE VALUES ARE
RESTRICTED SOMEWHAT DUE TO CLOUD COVER...PERHAPS UP TO 500 J/KG OF
VERY THIN MUCAPE. THIS SHOULD LIMIT THUNDER COVERAGE TOO. DESPITE
THE INCREASED CLOUD COVER AND PRECIPITATION...STILL ANTICIPATING
TEMPERATURES TO RISE INTO THE 70S ON MONDAY...WARMEST EAST WHERE
SOME SUN COULD OCCUR. LOWS STAY UP TOO MONDAY NIGHT WITH THE SURFACE
COLD FRONT STILL WAY OFF TO THE WEST IN THE EASTERN DAKOTAS.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
310 AM CDT SAT MAR 17 2012
LONG TERM FORECAST IS BECOMING MORE UNCERTAIN...PRIMARILY BECAUSE
MODELS ARE STRUGGLING ON HOW TO HANDLE THE WESTERN U.S. TROUGH FROM
MONDAY NIGHT. 17.00Z ECMWF/GFS/CANADIAN AND MOST GFS ENSEMBLES ALL
SUGGEST THE TROUGH WILL CUT-OFF AS IT CROSSES THE PLAINS TUESDAY AND
WEDNESDAY...BUT EXACTLY WHEN AND THEN HOW TO HANDLE THIS UPPER LOW
VARIES AMONG EVERY MODEL. THERE STILL REMAINS A FEW GFS ENSEMBLES
AND THE 17.00Z UKMET THAT SUGGEST THE TROUGH STAYS TOGETHER...
FOLLOWING THE 16.12Z ECMWF IDEA. HOWEVER...OVER THE LAST COUPLE DAYS
OF MODEL RUNS...THESE SEEM TO BE AN OUTLIER. THEREFORE PREFERENCE IS
TO FOLLOW THE MAJORITY 17.00Z GUIDANCE. AS THE UPPER TROUGH
APPROACHES THE FORECAST AREA TUESDAY INTO WEDNESDAY...THE MOISTURE
STREAM REFERENCED IN THE MONDAY/MONDAY NIGHT DISCUSSION WILL FULLY
SHIFT OVERHEAD. SEEMS LIKE TUESDAY NIGHT IS THE BEST PERIOD FOR THE
ENTIRE FORECAST AREA TO SEE RAIN. MODEL GUIDANCE CONSENSUS OF 60-70
PERCENT CHANCES ARE REASONABLE...BUT MAY NEED TO BE RAISED MORE IF
THIS TIME PERIOD REMAINS CONSISTENT FOR PRECIPITATION. AFTER
WEDNESDAY...ATTENTION TURNS TO THE SOUTHERN END OF THE SPLITTING
UPPER TROUGH WHICH TURNS INTO AN UPPER LOW. SOME MODELS SUGGEST THE
UPPER LOW COULD LIFT TOWARDS THE AREA ON FRIDAY. IF SO...THEN SOME
SHOWERS COULD MOVE IN. FOR NOW...HAVE LOWER 20-40 PERCENT CHANCES
FOR WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...ACCOUNTING FOR THE
DIMINISHING MOISTURE STREAM AND THE APPROACH OF THE UPPER LOW.
REGARDING THUNDER...REDUCED THESE PROBABILITIES TO 20 AND ONLY
DURING THE DAYTIME HOURS FOR TUESDAY THROUGH THURSDAY...GIVEN LESS
THAN 500 J/KG OF ONLY DAYTIME INSTABILITY SUGGESTED BY THE GFS.
TEMPERATURES THROUGHOUT MUCH OF THE LONG TERM PERIOD WILL STAY WELL
ABOVE NORMAL...UNTIL MAYBE FRIDAY NIGHT IF THE ECMWF IS RIGHT TRYING
TO SHOW SOME COLDER AIR COMING DOWN FROM CANADA. IN ANY
EVENT...850MB TEMPS DROP FROM 10-12C ON TUESDAY TO 6-8C BY 12Z
FRIDAY. A BLEND OF MODEL GUIDANCE SEEMED REASONABLE.
&&
.AVIATION...
1100 PM CDT FRI MAR 16 2012
WINDS WILL STAY UP TONIGHT...WITH BUFKIT SOUNDINGS INDICATING 10 TO
15 KTS BY 100-200 FT AND LITTLE IF ANY NOCTURNAL INVERSION TO HELP
LIGHTEN SFC WINDS. THE RELATIVELY MOIST AIR MASS FOR MID MARCH WILL
REMAIN IN PLACE...WITH SFC TDS IN THE UPPER 50S TO AROUND 60 THROUGH
THE WEEKEND. STILL...FEEL THE WINDS SHOULD MITIGATE THE FOG
POTENTIAL EARLY THIS MORNING...AND WILL TREND P6SM FOR NOW.
AFTERNOON INSTABILITY WITH NEARLY 300 PERCENT OF NORMAL PW IS AMPLE
FUEL FOR SHRA/TS...BUT HAVING A HARD TIME FINDING A KICKER. A WARM
FRONT IS WELL NORTH NOW...AND FCST SOUNDINGS SUGGEST MOST OF THE
INSTABILITY IS HOUSED ABOVE A LOW/MID LEVEL INVERSION THAT HANGS
THROUGH SAT-SUN. SO...THINK THE PCPN THREAT WILL BE VERY LOW UNTIL
EARLY NEXT WEEK. WILL KEEP TAF PCPN FREE...BUT IF A FOCUS FOR
SHRA/TS CAN BE FOUND...SOME INCLUSION IN THE TAFS MAY BE NEEDED.
A TIGHT PRESSURE GRADIENT WILL HOLD ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY THIS WEEKEND...AND BREEZY SOUTHERLY WINDS WILL
CONTINUE. MIXING VIA BUFKIT SOUNDINGS SUGGEST AFTERNOON GUSTS
UPWARDS OF 30 KTS AT KRST.
&&
.CLIMATE...TODAY THROUGH TUESDAY
310 AM CDT SAT MAR 17 2012
RECORD HIGHS AND RECORD WARM LOWS ARE POSSIBLE THROUGH TUESDAY...
ESPECIALLY THIS WEEKEND...AS AN UNSEASONABLY WARM AND MOIST AIR MASS
CONTINUES TO RESIDE ACROSS THE UPPER MIDWEST. TEMPERATURES SHOULD
BEGIN COOLING MON/TUE AS CLOUDS/ -SHRA INCREASE ACROSS THE AREA.
HOWEVER...RECORDS ON THOSE DAYS COMPARED TO FORECASTS STILL SUGGEST
SOME POTENTIAL TO BREAK THEM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
310 AM CDT SAT MAR 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
CLIMATE......AJ/RRS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1031 AM CDT SAT MAR 17 2012
.DISCUSSION...
ISSUED 1031 AM CDT SAT MAR 17 2012
FOG HAS BEEN SLOW TO DISSIPATE ACROSS CENTRAL ILLINOIS THIS
MORNING...WITH 15Z SATELLITE IMAGERY/SURFACE OBS INDICATING
FOG/LOW OVERCAST PERSISTING BETWEEN THE ILLINOIS RIVER VALLEY
AND THE I-55 CORRIDOR. VISBYS ARE NOW RAPIDLY IMPROVING...SO FOG
SHOULD NO LONGER BE AN ISSUE BY MIDDAY.
MID-LEVEL SHORT-WAVE EVIDENT ON WATER VAPOR IMAGERY OVER
KANSAS/OKLAHOMA WILL BE THE MAIN WEATHER-MAKER THIS AFTERNOON.
THIS FEATURE IS EXPECTED TO INTERACT WITH A VERY MOIST AND
INCREASINGLY UNSTABLE AIRMASS TO PRODUCE SCATTERED THUNDERSTORMS
ACROSS THE AREA. LATEST RADAR MOSAIC IS ALREADY SHOWING CONVECTION
DEVELOPING AHEAD OF THE WAVE FROM CENTRAL MISSOURI SOUTHEASTWARD
INTO WESTERN KENTUCKY. 12Z HRRR HAS A GOOD HANDLE ON THE CURRENT
SITUATION AND SHOWS THE CONVECTION TRACKING INTO CENTRAL ILLINOIS
AFTER 18Z. BASED ON LATEST TRENDS...HAVE MADE A FEW CHANGES TO THE
FORECAST...MAINLY TO INCREASE POPS INTO THE LIKELY CATEGORY ACROSS
THE S/SW KILX CWA. HAVE ALSO LOWERED AFTERNOON HIGHS BY A FEW
DEGREES DUE TO THE EXPECTED INCREASE IN CONVECTION. READINGS WILL
STILL REACH THE 80 DEGREE MARK ALONG/NORTH OF THE I-74 CORRIDOR...BUT
SHOULD STAY IN THE 70S FURTHER S/SW DUE TO CLOUDS/PRECIP.
BARNES
&&
.AVIATION...
ISSUED 656 AM CDT SAT MAR 17 2012
AVIATION WEATHER CONDITIONS ACROSS THE CENTRAL ILLINOIS TERMINALS
WILL BE SIMILAR TO HOW THEY HAVE BEEN THE PAST FEW DAYS...WHICH IS
TO SAY PRETTY QUIET FOR THE MOST PART. HOWEVER...PATCHY IFR
STRATUS/FOG WILL IMPACT AT LEAST KSPI/KDEC/KCMI TERMINALS FOR A
FEW HOURS THIS MORNING BEFORE BURNING OFF. THEN...VFR CIGS WILL
DEVELOP LATER TODAY AS AN UPPER LEVEL DISTURBANCE MOVES THROUGH
THE AREA...HELPING TO TRIGGER SCATTERED THUNDERSTORMS. HOWEVER...
THE COVERAGE IS EXPECTED TO BE TOO LOW TO GO ABOVE A VCTS MENTION
AT THIS TIME. THE LOWER CLOUDS WILL SCATTER OUT LATER TONIGHT AS
THE UPPER LEVEL SYSTEM PULLS AWAY. EXPECT WINDS TO REMAIN
SOUTHERLY...WITH THE HIGHEST SPEEDS AND A FEW GUSTS LIKELY DURING
THE PEAK MIXING OF THE AFTERNOON AND EARLY EVENING HOURS TODAY.
BAK
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT SAT MAR 17 2012
SHORT TERM...TODAY THROUGH TUESDAY
UNSEASONABLY WARM WEATHER STILL EXPECTED TO CONTINUE THROUGH AT
LEAST TUE WITH MORE RECORD HIGHS POSSIBLY TIED OR BROKEN.
CONVECTION CHANCES IS THE FORECAST CHALLENGE NEXT SEVERAL DAYS.
SHORT WAVE EJECTING NE TOWARD IL/MO BORDER BY SUNSET WILL INCREASE
CHANCES OF SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON
ESPECIALLY SOUTH OF I-72 AND CONTINUE CHANCES TONIGHT. SPC KEEPS
SLIGHT RISK OF SEVERE STORMS OVER FAR SOUTHERN IL INTO SE MO...
NORTHERN AR AND WESTERN PARTS OF KY/TN. ISOLATED SHOWERS AND
THUNDERSTORMS RECENTLY DEVELOPED OVER NW IL/SW WI NORTH OF I-80
AND WEST OF I-39 AND DRIFTING NE AWAY FROM CENTRAL IL. PATCHY FOG
DEVELOPING OVER SOUTHEAST IL ALONG HIGHWAY 50 WITH LAWRENCEVILLE
VSBY DOWN TO 1/2 MILE. MAY NEED TO ADD PATCHY FOG INTO MID MORNING
OVER AREAS SE OF I-70. NEAR RECORD HIGHS AROUND 80F ON THIS ST
PATRICKS DAY AND RECORD HIGHS LIKELY IN THE LOWER 80S SUNDAY WITH
JUST A 20-30% CHANCE OF SHOWERS AND THUNDERSTORMS OVER EASTERN IL
SUNDAY MORNING WITH MOSTLY CLOUDY SKIES BECOMING PARTLY TO MOSTLY
SUNNY SUNDAY AFTERNOON AS SHORT WAVE DEPARTS IL. DRY CONDITIONS
EXPECTED SUNDAY NIGHT.
DEEPENING UPPER LEVEL TROF OVER THE ROCKIES EARLY NEXT WEEK WITH
STRONG UPPER LEVEL RIDGE OVER THE EASTERN STATES. THIS TO CONTINUE
UNSEASONABLY WARM HIGHS IN THE UPPER 70S AND LOWER 80S MON/TUE
WITH MORE RECORD HIGHS LIKELY TIED OR BROKEN. HAVE 20-30% CHANCE
OF SHOWERS/THUNDERSTORMS MON-TUE WEST OF I-55 CLOSER TO UPPER
LEVEL TROF AND EJECTING SHORT WAVES OVER THE GREAT PLAINS AND
TOWARD THE MS VALLEY. EASTERN IL SHOULD GENERALLY STAY DRY AND
WARM DURING THIS TIME. SPC HAS SLIGHT RISK OF SEVERE STORMS WEST
OF IL MON AND MON NIGHT WHERE BETTER CHANCES OF THUNDERSTORMS WILL
BE.
LONG TERM...TUESDAY NIGHT THROUGH FRIDAY NIGHT
CHANCES OF SHOWERS AND THUNDERSTORMS INCREASE FROM WEST TO EAST
FROM TUE NIGHT THROUGH THU AS STRONG UPPER LEVEL TROF/LOW SHIFTS
EAST TOWARD THE MS VALLEY. HAVE LIKELY POPS OVER FAR WESTERN AREAS
TUE NIGHT AND INTO WESTERN AND SW AREAS BY WED NIGHT FROM PEORIA
TO TAYLORVILLE WEST. UPPER LEVEL TROF/LOW TO BE NEAR IL THU
WITH COOLER WEATHER AND CONTINUE CHANCES OF SHOWERS AND POSSIBLE
THUNDERSTORMS. UPPER LEVEL TROF/LOW SHIFTS EAST OF IL FRI WITH BEST
CHANCE OF SHOWERS/THUNDERSTORMS SHIFTING EAST OF IL INTO INDIANA AND
TEMPS COOLER FURTHER LATE NEXT WEEK.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
732 AM CDT SAT MAR 17 2012
.UPDATE...
UPDATED FOR THE 12Z AVIATION DISCUSSION BELOW.
.DISCUSSION...
LATEST WV IMAGERY OVERLAID WITH RUC 400-500MB LAYER WINDS SHOWS
SUBTLE SHORTWAVE RESPONSIBLE FOR THE EVENING CONVECTION ACROSS
NORTHERN WISCONSIN HAS MOVED NORTHEAST. MEANWHILE...ANOTHER WEAK
WAVE IS FORCING A FEW SHOWERS ACROSS SOUTHWEST WISCONSIN...BUT
THIS WILL REMAIN SOUTH AND EAST OF THE FORECAST AREA. FURTHER
UPSTREAM ANOTHER SHORT WAVE LOCATED OVER KANSAS WILL MOVE
NORTHEAST TODAY...BUT IT TOO SHOULD TRACK SOUTH AND EAST OF THE
CWA. GIVEN THE SUMMER LIKE AIRMASS IN PLACE...AS INDICATED BY
THE TROPOPAUSE HEIGHT OF 225 MB VIA THE 00Z MPS RAOB...A SMALL
AMOUNT FORCING IS SUFFICIENT TO PRODUCE CONVECTION. HOWEVER...HAVE
KEPT THE FORECAST DRY FOR TODAY AND SUNDAY SINCE CONFIDENCE IS LOW
THAT SHOWERS AND THUNDERSTORMS WILL DEVELOP DESPITE THE HIGH CAPE
VALUES. THINKING IS THAT A WIDESPREAD CUMULUS FIELD WILL ENSUE
RATHER THAN ANY DEEP CONVECTION.
BY SUNDAY NIGHT A LONG WAVE TROUGH THAT IS CURRENTLY DIGGING OFF
THE COAST OF CALIFORNIA WILL BEGIN TO AFFECT THE UPPER MIDWEST.
MODELS SHOW A WEAK SHORTWAVE MOVING UP FROM THE SOUTHWEST IN
CONJUNCTION WITH A STRENGTHENING LOW LEVEL JET. THIS SHOULD
TRIGGER SOME SHOWER AND THUNDERSTORM DEVELOPMENT SUNDAY NIGHT INTO
MONDAY. THE BEST DYNAMICS REMAIN TO THE WEST IN THE VICINITY OF A
+120KT GET...SO DEEP LAYER SHEAR VALUES IN THE 20-25KT RANGE
INDICATE A MINIMAL THREAT FOR SEVERE WEATHER. THIS IS ALSO
SUPPORTED BY THE NARROW CAPE PROFILES IN THE FORECAST SOUNDINGS.
LOOKS LIKE SOME MUCH NEEDED RAIN SHOWERS WILL BE THE MAIN
RESULT...WITH A FEW SUB SEVERE THUNDERSTORMS MIXED IN AS WELL.
MODELS THEN TRANSITION THIS TROUGH TO A CUTOFF LOW ON WEDNESDAY
AND VARY IN LOCATION. THE GEM 17.00 IS FURTHEST SOUTH OVER
ARKANSAS...WHILE THE ECMWF TAKES IT ACROSS THE OHIO RIVER
VALLEY...AND THE GFS 17.00 IS SLOW TO MOVE THIS SYSTEM OUT FROM
THE CENTRAL CONUS. GIVEN THE MODEL UNCERTAINTY...DID NOT DEVIATE
MUCH FROM GUIDANCE IN THE EXTENDED.
&&
.AVIATION.../12Z TAF ISSUANCE/
THIS MORNING IS QUITE SIMILAR TO WHAT WAS OBSERVED FRIDAY
MORNING - VFR STRATUS IN EASTERN MN AND WESTERN WI...MVFR/IFR
CEILINGS DEVELOPING IN NORTHWEST IA AND NORTHEAST NE AND ADVECTING
NORTH WITH TIME. ONCE AGAIN KRWF IS IN THE BEST SPOT TO SEE 1500FT
CEILINGS MOVE IN FOR A COUPLE HOURS LATE THIS MORNING. CIGS/VIS WON`T
BE NEARLY AS POOR TODAY HOWEVER. PLENTY OF 4-5SM FOG ACROSS THE
REST OF THE AREA THAT WILL QUICKLY BURN OFF ONCE THE SUN GETS UP
ABOVE THE HORIZON. THE WIND IS HELPING TO KEEP THE FOG IN CHECK.
TOWERING CUMULUS WITH BASES BETWEEN 3500-6000FT APPEAR LIKELY ONCE
AGAIN BY THIS AFTERNOON. THERE ARE A COUPLE MORE RIPPLES IN THE
ATMOSPHERE THAT MIGHT KICK OFF ANOTHER ROUND OF SHOWERS AND STORMS
IN WI/IA/IL LATE THIS AFTERNOON...BUT WHAT ACTIVITY FORMS SHOULD
BE SOUTH OF THE TAF SITES. THE WAVE THAT COULD TRIGGER STORMS IS
BACK IN KS/NE AND SHOULD TAKE 9-12HRS TO MAKE IT TO WI. SAME STORY
SUNDAY MORING - HOW MUCH FOG/STRATUS WILL THERE BE? THERE IS NO
CHANGE IN AIR MASS...HAVE A LOT OF MVFR NEAR THE END OF THE TAF.
KMSP...SKIES SHOULD ONCE AGAIN FILL WITH CUMULUS CLOUDS WITH
DECENT VERTICAL EXTENT THIS AFTERNOON AFTER A MOSTLY CLEAR
MORNING. VFR CONDITIONS EXPECTED THROUGHOUT THE DAY. SOME
INDICATION OF ANOTHER STRATUS DECK AND FOG EARLY SUNDAY MORNING.
HOWEVER...WE HAVE OVERDONE THE MVFR/IFR CONDITIONS THE LAST COUPLE
MORNINGS EVEN THOUGH THERE HAS BEEN PLENTY OF LOW LEVEL MOISTURE.
SHOULD SEE WINDS REALLY PICK UP EARLY THIS AFTERNOON AND THERE
WONT BE MUCH CHANGE IN DIRECTION FROM WHERE WE ARE NOW.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JRB/CLF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
920 AM CDT SAT MAR 17 2012
.UPDATED...LATEST SATELLITE IMAGERY SHOWED THAT THE REGION WAS UNDER
THE INFLUENCE OF A STRONG MEAN RIDGE. THIS WAS NOTED BY THIS
MORNINGS UPPER SOUNDING...WHICH REQUIRED AROUND 98 DEGREES SURFACE
TEMP TO BREAK THE MEGA MID LEVEL CAP AT 700 MB. THERE WERE SOME MINOR
PERTURBATIONS IN THE UPPER WEST SOUTHWEST FLOW COMING FROM THE
SOUTHERN PLAINS. LATEST HIGH RESOLUTION MODELS AND RUC SHOW THAT THE
CAP WILL HOLD AND WE MAY SEE SOME ISOLATED CONVECTION IN THE NORTH
AS A WEAK SHORT WAVES PASSES NORTH OF THE REGION. SO KEPT LOW
ISOLATED POPS THERE. CURRENT HIGHS 82-84 LOOKS TO BE ON TRACK. LOW
LEVEL WINDS IN THE MORNING SOUND WERE ON THE LIGHT SIDE. HAVE
ALLOWED THE DENSE FOG ADVISORY IN THE SOUTH TO EXPIRE. PIB WAS
HOLDING ON AT 1/2 MILE...BUT EXPECT THAT TO LIFT BY AROUND 15Z.
OTHERWISE THE REST OF THE FORECAST APPEARS TO BE ON TRACK./17/
./PREVIOUS DISCUSSION...443 AM CDT SAT MAR 17 2012
.DISCUSSION...
A WARM AND MOSTLY DRY PATTERN WILL CONTINUE THROUGH THE WEEKEND AND
INTO EARLY NEXT WEEK...THEN A LARGE UPPER TROUGH WILL APPROACH
THE ARKLAMISS FOR THE MIDDLE OF NEXT WEEK BRINGING THE CHANCE FOR
HEAVY RAINFALL AND A FEW STRONG TO SEVERE STORMS.
TODAY THROUGH SUNDAY NIGHT...
A STRONG MID LEVEL RIDGE AXIS CURRENTLY CENTERED OVER THE
ARKLAMISS IS FORECAST BY SHORT TERM MODEL GUIDANCE TO SHIFT VERY
LITTLE EAST AS WE GO THROUGH THE WEEKEND. THE RIDGE WILL ACT TO
DEFLECT MINOR PERTURBATIONS AND KEEP THE AREA MOSTLY PRECIPITATION-
FREE...HOWEVER CONVECTIVE PRECIPITATION DEVELOPING ON THE WESTERN
PERIPHERY OF THE RIDGE COULD MANAGE TO SNEAK INTO EXTREME WRN/NRN
PORTIONS OF THE FORECAST AREA LATER TODAY AND AGAIN SUNDAY ---
ESPECIALLY IN THE AFTERNOON/EVNG AS REFLECTED BY GUIDANCE MOS POPS.
A MID LEVEL SUBSIDENCE CAP WILL GREATLY LIMIT THE POTENTIAL FOR
TSTMS IN ANY CASE OVER THE FORECAST AREA.
FOG WILL CONTINUE TO BE A CONCERN THIS MORNING PRIMARILY SOUTH OF
THE I-20....AND ESPECIALLY SUNDAY MORNING WHEN MID/HIGH LEVEL
CLOUDINESS SHOULD NOT BE SO PREVALENT AND DISRUPTIVE OF NIGHTTIME
COOLING. FORECAST PERSISTENCE SUGGESTS THAT DENSE FOG COULD DEVELOP
AGAIN IN THE HBG AREA. OTHERWISE...LOOK FOR MORE OF THE SAME IN
REGARD TO TEMPERATURES WITH WELL-ABOVE NORMAL READINGS (~ 15 DEG F)
EXPECTED. /EC/
MONDAY THROUGH SATURDAY...
A HIGHLY AMPLIFIED UPPER AIR PATTERN WILL BE IN PLACE ACROSS THE
CONUS AT THE START OF NEXT WEEK COMPOSED OF A STRONG ANTICYCLONE
OVER THE EASTERN SEABOARD AND A DEEP TROUGH ALONG THE CONTINENTAL
DIVIDE. THE 00Z NWP GUIDANCE HAS DIFFERING OPINIONS AS TO HOW THIS
PATTERN WILL EVOLVE AS WE HEAD INTO MID WEEK...LEAVING CONFIDENCE
LOWER THAN USUAL FOR THIS TIME PERIOD. THE OP GFS AND GFS ENSEMBLE
MEAN ARE FAIRLY SIMILAR WITH THEIR EVOLUTIONS SHOWING A CUT-OFF LOW
DEVELOPING OVER THE SOUTH CENTRAL PLAINS LATE TUE INTO EARLY WED
WHICH THEN TAKES ITS TIME TO SHIFT EAST AS THE MAIN BELT OF
WESTERLIES REMAIN WELL NORTH. THE ECMWF MAINTAINS A LITTLE BETTER
PHASING WITH THE POLAR JET UNTIL LATER IN THE WEEK WHEN A CUT-OFF
LOW DEVELOPS OVER THE TN VALLEY AND GRADUALLY SHIFTS EAST.
CONFIDENCE IS SOMEWHAT HIGHER IN THE SLOWER/EARLIER CUT-OFF SOLUTION
OFFERED BY THE GFS/GEFS WHICH WILL KEEP HIGHER POPS AT BAY UNTIL A
BIT LATER THAN OFFERED BY THE EURO. SHOWERS/THUNDERSTORMS MAY BEGIN
IMPACTING AREAS WEST OF THE RIVER AS EARLY AS TUE AFTERNOON BUT FOR
SURE BY TUE NIGHT AS SYNOPTIC LIFT AHEAD OF THE LOW BEGINS TO
OVERSPREAD THE REGION.
SLOW PROGRESSION OF THE UPPER LOW/DEEPLY SATURATED PROFILES/
UNIDIRECTIONAL SOUTHERLY FLOW IS GOING TO ENHANCE THE RISK FOR
LOCALLY HEAVY RAINFALL AS THIS SYSTEM PASSES ALTHOUGH PINPOINTING
WHERE EXACTLY THAT MIGHT BE IS TOUGH AT THIS JUNCTURE. THE RISK FOR
SEVERE WEATHER IS GOING TO BE A BIG QUESTION MARK FOR THE SAME
REASONS AS RESULTANT DEEP LAYER SHEAR REMAINS MARGINAL AT BEST. WILL
CONTINUE TO HIGHLIGHT THE RISK FOR HEAVY RAINS/STRONG TO SEVERE
THUNDER POTENTIAL IN THE HWO...BUT THE POTENTIAL FOR HEAVY RAINS ARE
PROBABLY THE BIGGER CONCERN.
THE DEEPER MOISTURE WILL SHIFT EAST LATE IN THE WEEK BRINGING A
RETURN OF DRY WEATHER BY FRI/SAT. TEMPS WILL BE A BIT COOLER WED-SAT
AS THE RAINS AND COOLER TEMPS MOVE IN...BUT ABOVE NORMAL TEMPS STILL
EXPECTED LATE WEEK.
ONLY OTHER ITEM OF NOTE IS THE POTENTIAL FOR SOME GUSTY SOUTH WINDS
MON AND ESPECIALLY TUE AS THE LOW APPROACHES. ITS POSSIBLE SUSTAINED
WINDS OF 20-25 MPH WITH GUSTS CLOSE TO 35 OR 40 MPH COULD DEVELOP
PROMPTING THE NEED FOR A WIND ADVISORY(ESPECIALLY ACROSS THE DELTA)
IF THIS UNFOLDS. /BK/
&&
.AVIATION...MORNING FOG/STRATUS WAS HOLDING SITES ALONG I-20 AND
SOUTH TO IFR/LIFR CONDITIONS WHILE VFR CONDITIONS WERE BEING
OBSERVED IN THE NORTH. THE FOG SHOULD BEGIN DISSIPATING AFTER 15Z
AND VFR CONDITIONS SHOULD PREVAIL AREAWIDE BY 16Z. PERSISTENT
SOUTHERLY FLOW WILL CONTINUE THE PROSPECTS FOR LATE NIGHT/EARLY
MORNING STRATUS/FOG GOING INTO EARLY NEXT WEEK WITH VFR CONDITIONS
EXPECTED TO PREVAIL DURING THE DAY. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 84 60 84 59 / 8 4 10 10
MERIDIAN 84 54 85 54 / 8 3 4 5
VICKSBURG 83 61 84 61 / 8 4 18 13
HATTIESBURG 84 59 85 58 / 8 9 9 7
NATCHEZ 82 64 82 63 / 8 4 22 12
GREENVILLE 82 61 83 62 / 9 4 14 19
GREENWOOD 84 61 86 62 / 12 4 9 13
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
17/EC/BK
AREA FORECAST DISCUSSION
NWS BILLINGS MT
956 AM MDT SAT MAR 17 2012
.SHORT TERM...VALID FOR TDY AND SUN...
EASTERLY LOW-LEVEL FLOW IS IN PLACE OVER THE AREA AT 15 UTC THANKS
TO 3-HOUR SURFACE PRESSURE FALLS ON THE ORDER OF 2 HPA THAT EXTEND
FROM SHERIDAN NORTHWEST TO GREAT FALLS. THE 12 UTC NAM AND RUC ARE
CONSISTENT IN SHOWING A SURFACE LOW DEEPENING OVER CENTRAL MT THIS
AFTERNOON...WITH RELATIVELY IMPRESSIVE LOW- AND MID-LEVEL WARM AIR
ADVECTION OVER SOUTHEASTERN MT AS A WARM FRONT RAPIDLY LIFTS NORTH
IN STRENGTHENING SOUTHERLY FLOW. FORECAST SOUNDINGS SUGGEST MIXING
TO 700 HPA AND MEAN WINDS IN THAT LAYER OF 25 TO 30 KT BEHIND THIS
WARM FRONT IN PLACES LIKE SHERIDAN...BROADUS...AND MILES CITY. THE
850-HPA TEMPERATURES ARE EXPECTED TO APPROACH 20 C IN SOUTHEASTERN
MT BY 00 UTC...SO HIGHS SHOULD NOT HAVE MUCH PROBLEM REACHING INTO
THE UPPER 70S F. AN 80 F READING IS NOT OUT OF THE QUESTION IF THE
THERMAL RIDGE DOES MAKE IT INTO THE BROADUS AREA BY 00 UTC. THOUGH
DEWPOINTS ARE IN THE MID 30S F EVEN AT GILLETTE AS OF 15 UTC...THE
SYNOPTIC EVOLUTION AND MIXING SHOULD BRING A SURGE OF VERY DRY AIR
OUT OF WY AND INTO SOUTHEASTERN MT BY 00 UTC. THE RED FLAG WARNING
THUS LOOKS ON TRACK.
ONLY MINOR CHANGES WERE MADE TO THE FORECAST...MAINLY TO MAKE SOME
SLIGHT ADJUSTMENTS TO WINDS. BOTH WINDS AND TEMPERATURES COULD END
UP A BIT TOO LOW IN PLACES LIKE BILLINGS IF THE FURTHER WEST SURGE
OF WARM AIR AND MIXING THAT THE 12 UTC RUC SUGGESTS IS CORRECT. WE
DO NOT HAVE ENOUGH CONFIDENCE TO MAKE ANY DRASTIC MOVE TOWARD THAT
SOLUTION AT THIS POINT THOUGH. SCHULTZ
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
THE EXTENDED BEGINS MONDAY WITH A DEEP NEGATIVELY-TILTED UPPER
LEVEL TROUGH MOVING SLOWLY EASTWARD ACROSS THE REGION. STRONG QG
FORCING AND FRONTOGENESIS BEHIND A SURFACE LOW IN EASTERN
MONTANA COMBINE WITH SHORTWAVE ENERGY AND UPPER LEVEL DIVERGENCE
TO PRODUCE PRECIP ACROSS THE REGION. FAIRLY STRONG COLD AIR
ADVECTION WILL ALLOW THE PRECIP TO FALL AND ACCUMULATE AS SNOW IN
THE FOOTHILLS AND MOUNTAINS WITH SEVERAL INCHES POSSIBLE. ACROSS
FAR EASTERN MONTANA...THE PRECIP WILL FALL MAINLY AS RAIN WITH
TEMPS MAINLY IN THE 40S. PRECIP BEGINS TO DISSIPATE OVERNIGHT
MONDAY INTO TUESDAY AS DRY AIR WRAPS INTO THE REGION BEHIND THE
DEPARTING SURFACE LOW AND THE FILLING UPPER LEVEL TROUGH.
TEMPERATURES WILL REMAIN MAINLY IN THE 40S TO NEAR 50 ACROSS THE
REGION TUESDAY.
UPPER LEVEL RIDGING MOVES INTO THE REGION LATE TUESDAY AND REMAINS
OVER THE AREA INTO THURSDAY. THIS WILL ALLOW TEMPERATURES TO WARM
INTO THE 50S AND 60S BOTH WEDNESDAY AND THURSDAY. AT THE SAME
TIME...THE SURFACE PRESSURE GRADIENT TIGHTENS UP ACROSS THE WEST
IN RESPONSE TO HIGH PRESSURE STRENGTHENING UNDER THE RIDGE ACROSS
THE CENTRAL ROCKIES. THIS WILL CAUSE SOUTHWEST WINDS TO INCREASE
ACROSS WESTERN ZONES...ESPECIALLY IN THE FOOTHILLS FROM LIVINGSTON
TO NYE. AS SUCH...INCREASED WINDS ACROSS THE WEST JUST A BIT
TUESDAY NIGHT INTO EARLY THURSDAY.
MODELS DIVERGE A BIT IN THEIR SOLUTIONS LATE THURSDAY INTO FRIDAY.
THE ECMWF DRIVES A STRONG COLD FRONT THROUGH THE REGION LATE
THURSDAY WITH PRECIP MAINLY CONFINED TO THE WESTERN MOUNTAINS. THE
GFS FORECASTS A WEAK COLD FRONT TO MOVE INTO THE REGION
FRIDAY...AT WHICH POINT IT STALLS ACROSS THE AREA THROUGH FRIDAY
NIGHT. BOTH MODELS FORECAST A RETURN TO RIDGING ALOFT SATURDAY.
DUE TO THE MODEL UNCERTAINTY...DID NOT MAKE ANY MAJOR CHANGES TO
THE THURSDAY TO SATURDAY TIMEFRAME. STC
&&
.AVIATION...
SCATTERED RAIN AND HIGH ELEVATIONS SNOW SHOWERS WILL IMPACT OUR
WEST TODAY AND TONIGHT...INCLUDING KLVM. EXPECT THE BEARTOOTH
ABSAROKAS AND THE CRAZIES TO BE OBSCURED FREQUENTLY. VFR WILL
PREVAIL AT ALL TAF SITES EXCEPT FOR LOCAL MVFR IN THE KLVM AREA
DUE TO THE SHOWERS. THERE IS ALSO A SLIGHT RISK OF THUNDERSTORMS
IN OUR WEST THIS AFTERNOON. EXPECT SOUTHERLY WINDS TO INCREASE
ACROSS THE PLAINS THROUGH THE DAY WITH GUSTS OF 20-30 KTS BY
AFTERNOON. JKL
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 070 042/065 034/045 028/049 031/060 036/062 035/058
2/W 13/W 66/O 21/B 01/B 11/B 10/B
LVM 063 037/055 027/039 025/042 030/054 034/055 033/053
4/T 36/W 77/S 32/W 21/N 12/W 21/B
HDN 074 041/070 032/047 027/050 029/062 033/064 031/061
1/B 12/W 46/O 31/B 01/B 11/B 10/B
MLS 079 040/070 036/049 028/049 030/061 034/064 034/059
1/N 11/B 25/R 21/B 11/B 11/B 11/B
4BQ 077 044/074 036/051 027/049 030/062 034/066 034/060
1/N 01/N 25/R 21/B 11/B 11/U 10/B
BHK 077 041/073 040/053 028/048 029/061 035/064 034/057
1/N 01/B 22/R 21/B 10/B 01/U 11/B
SHR 075 039/070 033/046 024/045 027/060 030/062 031/056
1/N 12/W 36/O 31/B 01/B 11/B 10/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...RED FLAG WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR
ZONES 130>133.
WY...RED FLAG WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR
ZONE 274.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1017 AM CDT SAT MAR 17 2012
.UPDATE...REST OF TODAY
STRATUS CLOUDS ARE QUICKLY FILLING IN AND EXPANDING ACROSS THE
EASTERN CWA AS LOW LEVEL MOISTURE CONTINUES TO STREAM NORTHWARD.
SEVERAL CHANGES NEEDED TO WEATHER ELEMENTS THIS MORNING TO ACCOUNT
FOR THIS. INCREASED SKY COVER QUITE A BIT THROUGH THE MORNING AND
INTO THE AFTERNOON. RUC SOUNDINGS ON BUFKIT PICKING UP ON THESE
CLOUDS AND WOULD SUGGEST STRATUS STICKING AROUND INTO EARLY
AFTERNOON BEFORE STRATOCU-ING OUT. THIS ALSO THROWS A WRENCH INTO
THE TEMP RISE THIS MORNING SO ADJUSTED HOURLY READINGS. DID NOT
MESS WITH HIGHS AT THIS TIME SINCE BY MID TO LATE AFTERNOON STILL
EXPECTING CLOUDS TO BREAK UP AND TEMPS TO RISE. WILL MONITOR THIS
THOUGH. DEWPOINTS RISING THROUGH THE 50S ACROSS THE EASTERN CWA.
FOG STILL HANGING AROUND IN SPOTS AS WELL SO EXTENDED MENTION OF
THIS FOR A COUPLE MORE HOURS. FARTHER WEST...PLENTY OF SUNSHINE
ALL DAY WITH VERY LOW RH VALUES IN THE AFTERNOON LEADING TO HIGH
TO VERY HIGH FIRE DANGER. STILL APPEARS WINDS WILL NOT BE STRONG
ENOUGH TO WARRANT ANY FIRE HEADLINES FOR THIS AFTERNOON.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...THROUGH MONDAY
PRESSURE GRADIENT CONTINUES TO RELAX...WHICH WILL RESULT IN
LIGHTER WINDS TODAY...LESS EFFICIENT MIXING...AND HIGHER HUMIDITY.
A POCKET OF HIGHER MOISTURE AIR SITS ACROSS THE EAST AND WILL
EXPAND WESTWARDS WITH SOUTH/SOUTHEAST WINDS TODAY...SO
TEMPERATURES WILL BE SOMEWHAT LESS EXTREME DESPITE SIMILAR
TEMPERATURES ALOFT. AS UPPER TROF CONTINUES TO SLOWLY PUSH
EAST...WILL SEE LEE CYCLOGENISIS ACROSS WESTERN SOUTH
DAKOTA...INCREASING THE GRADIENT OVERNIGHT ALONG WITH WEAK LOW
LEVEL JET FORMATION. A TIGHT HUMIDITY GRADIENT WILL CONTINUE
ACROSS THE AREA OVERNIGHT AS WELL. AS THE SYSTEM SHIFTS EAST
SUNDAY...PRESSURE GRADIENT INTENSIFIES ALONG WITH A 50-60KT H85
JET MAX. HAVE ISSUED A FIRE WEATHER WATCH GIVEN DEEP MIXING WHICH
WILL HELP MIX OUT SHALLOW MOISTURE IN THE WEST. THERE IS PLENTY OF
UNCERTAINTY OVER HOW EFFICIENTLY THIS MOISTURE WILL MIX OUT IN THE
EAST. WINDS WILL STAY UP OVERNIGHT SUNDAY/EARLY MONDAY AS WELL.
AS FOR PRECIPITATION CHANCES...WITH WARM LOW LEVEL AIRMASS...WILL
SEE STEEP LAPSE RATES ALOFT THROUGH MOST OF THE PERIOD. MOISTURE
IS RELATIVELY SHALLOW AND DYNAMICS ARE LACKING FOR MOST OF THE
PERIOD TO WARRANT MENTION OF THUNDER...UNTIL LATE SUNDAY. A WEAK
WAVE IN SOUTHWEST FLOW COULD SUPPORT HIGH BASED ALTO CUMULUS. MORE
WIDESPREAD CONVECTION IS POSSIBLE WITH A STRONGER WAVE LIFTING
NORTH WITH A SLOW MOVING NORTH/SOUTH ORIENTED COLD FRONT PROVIDING
THE FOCUS FOR THUNDERSTORMS.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
THE THEME DURING THE EXTENDED IS COOL DOWN. MONDAY NIGHT...A COLD
FRONT IS WORKING ACROSS THE EASTERN HALF OF FORECAST ZONES...WITH
NOTABLY COOLER/DRIER AIR ADVECTING IN BEHIND FOR TUESDAY AND
WEDNESDAY. FOLLOWED THE PREFERRED ECMWF SOLUTION FOR HANDLING THE
CLOSED UPPER LOW ENERGY OVER THE LOWER/MID-MISSISSIPPI VALLEY
REGION...WHICH IS TO PROPAGATE THE LOW EASTWARD AWAY FROM THIS
REGION AS THE WEEK WEARS ON...VERSUS THE GFS SOLUTION THAT STILL
TRIES TO DRAW THE CLOSED UPPER LOW NORTHWARD TOWARD IOWA.
THE ECMWF ACTUALLY DOES TRY TO BRING A BIT OF RETURN FLOW WARMTH
BACK INTO THE REGION ON THURSDAY BEFORE A LOW PRESSURE SYSTEM IN
THE FAST WESTERLY FLOW ACROSS SOUTHERN CANADA DRAGS A COLD FRONT
ACROSS THE CWA...MAINLY THURSDAY NIGHT...RENDERING FRIDAY ALSO A
BIT COOLER. NOW...BY COOLER AND DRIER...NOT SPEAKING OF HIGHS IN
THE 30S TO LOW 40S. RATHER...HIGH TEMPERATURES WILL LIKELY BE MORE
LIKE 50S FOR TUESDAY AND WEDNESDAY /STILL ABOVE NORMAL/...A BIT
WARMER FOR THURSDAY...AND THEN LIKELY BACK DOWN INTO THE 50S FOR
FRIDAY.
PRECIPITATION CHANCES ARE TRENDING DOWNWARD MONDAY NIGHT AND ALL
BUT GONE ON TUESDAY...WITH DRY FORECAST CONDITIONS PERSISTING
THROUGH THURSDAY. THERE MAY BE ENOUGH LIFT/FORCING AND MOISTURE
AROUND THURSDAY NIGHT...ATTACHED TO THE COLD FROPA...TO SEE A FEW
SHOWERS DEVELOP...MAINLY OVER NERN SODAK OVER INTO MN.
THEN...THE FORECAST TIPS BACK OVER TO A DRY ONE ON FRIDAY.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE STILL EXPECTED AT MBG AND PIR THROUGH TODAY
AND TONIGHT. LOW LEVEL MOISTURE HAS BEEN INCREASING EARLY THIS
MORNING AND COULD BRING SOME LIGHT FOG AND LOW STRATUS TO PARTS OF
NORTHEAST SOUTH DAKOTA THIS MORNING INCLUDING AT ABR AND ATY...BUT
ESPECIALLY AT ATY. OTHERWISE...ANY LOW CLOUDS AND FOG WILL BREAK UP
THROUGH THE LATE MORNING AND EARLY AFTERNOON WITH IFR CIGS LIFTING
TO MVFR CIGS...BUT PROLLY NOT DISSIPATING COMPLETELY. LATER
TONIGHT AFTER SUNSET...SCT-BKN COVERAGE OF LOW CIGS AND/OR FOG IS
EXPECTED TO RE-ESTABLISH OVER CENTRAL AND EASTERN SOUTH DAKOTA.
WILL NEED TO MONITOR AND ADJUST FOG/STRATUS COVERAGE LATER TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR LOWER BAD RIVER-MISSOURI COTEAU-UPPER CHEYENNE-UPPER
JAMES RIVER-UPPER MISSOURI COTEAU.
MN...NONE.
&&
$$
UPDATE...TMT
SHORT TERM...CONNELLY
LONG TERM...DORN
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
710 AM CDT SAT MAR 17 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
310 AM CDT SAT MAR 17 2012
MAIN FORECAST CONCERNS ARE ON ANY CHANCES FOR PRECIPITATION THROUGH
SUNDAY NIGHT...WINDS AND THE UNPRECEDENTED WARMTH.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT
ANALYSIS SHOWED DEEP TROUGHING JUST OFF THE CALIFORNIA COAST WHILE
BROAD RIDGING WAS BUILDING DOWNSTREAM OVER THE EASTERN TWO THIRDS
OF THE U.S.. RIDGE AXIS SITS OVER THE GREAT LAKES...PLACING THE
FORECAST AREA UNDER SOUTHWEST FLOW. WITHIN THIS SOUTHWEST FLOW...A
WEAK SHORTWAVE COMBINED WITH A WARM FRONTAL BOUNDARY AND
INCREASING LOW LEVEL JET TO PRODUCE A CLUSTER OF STRONG TO SEVERE
SHOWERS AND THUNDERSTORMS LAST EVENING OVER CENTRAL WISCONSIN.
THESE HAVE SINCE LIFTED INTO UPPER MICHIGAN THANKS TO THE
SHORTWAVE MOVING NORTHEAST AND A 30-40 KT SOUTHWEST JET AT 850MB.
WITHIN THIS SOUTHWEST FLOW...THE ONLY SHORTWAVES OF NOTE ARE WEAK
ONES IN NEBRASKA...AND THESE ARE NOT PRODUCING MUCH CLOUDS AT ALL.
WITH THE FORECAST AREA UNDER THAT STRONG SOUTHWEST JET AND A
RELATIVELY TIGHT PRESSURE GRADIENT AT THE SURFACE AHEAD OF A
TROUGH IN THE DAKOTAS... TEMPERATURES HAVE STRUGGLED TO FALL.
READINGS ARE ONLY IN THE 60S. DEWPOINTS ARE ALSO STAYING UP IN THE
MID TO UPPER 50S. AIRMASS IS ALSO SEMI-CAPPED AND DRY...LOOKING AT
THE 00Z DVN SOUNDING. GOING FARTHER SOUTHWEST TO OAX AND IT DRIES
OUT EVEN MORE. DESPITE THE DRIER AIR...THERE IS ENOUGH INSTABILITY
WHEN LIFTED FROM 800MB /APPROX 700 J/KG/ TO PRODUCE PRECIPITATION.
A ZONE OF 800MB SPEED CONVERGENCE IN SOUTHWEST WISCONSIN AND
NORTHWEST ILLINOIS HAS PRODUCED SOME SHOWERS DOWN THERE.
TODAY THROUGH SUNDAY NIGHT...UPPER TROUGHING APPROACHING THE WEST
COAST OF THE U.S. RIGHT NOW IS PROGGED BY ALL MODELS TO MOVE INTO
THE ROCKIES BY 12Z MONDAY. A FAIRLY DEEP LOW PRESSURE SYSTEM ENDS UP
DEVELOPING OVER EASTERN MONTANA AS THIS TROUGH MOVES EAST...ALLOWING
FOR STRONG SOUTHERLY FLOW TO PERSIST DOWNSTREAM INTO OUR FORECAST
AREA. A COUPLE OF IMPACTS FROM THIS STRONG SOUTHERLY FLOW INCLUDE:
1. HELPING TO MAINTAIN THE UNSEASONABLY HIGH DEWPOINTS...WHICH COULD
EXCEED 60F AT TIMES BETWEEN 15-18Z BEFORE DROPPING DUE TO MIXING.
2. MAINTAIN THE UNSEASONABLY WARM 925 AND 850MB TEMPS...WHICH ARE
PROGGED TO STAY BETWEEN 16-20C AND 12-14C RESPECTIVELY. THESE
READINGS ARE VERY SIMILAR TO WHAT WAS SEEN FRIDAY...SO HIGH
TEMPERATURES BOTH TODAY AND SUNDAY ARE LIKELY TO BE SIMILAR. SOME
HINTS FROM MET GUIDANCE WHICH DID WELL YESTERDAY THAT SITES SUCH AS
BOSCOBEL COULD HIT THE MID 80S. GENERALLY FOLLOWED THIS.
3. A LOT OF GUSTY WINDS THROUGHOUT. APPEARS THAT WHEN LOOKING AT
SOUNDINGS...MIXING DEPTHS AT MOST APPROACH 850MB. MOMENTUM TRANSFER
FROM THIS LEVEL KEEPS WINDS BELOW ADVISORY CRITERIA...EVEN AT RST.
4. RESULTING FROM ITEMS 1-3 ABOVE...LOW TEMPERATURES ARE GOING TO
STAY VERY WARM FOR THIS TIME OF YEAR...LIKELY STRUGGLING TO GET MUCH
BELOW 60.
REGARDING PRECIPITATION...TRIGGERS ARE VERY HARD TO FIND THROUGH
SUNDAY NIGHT. IN ADDITION...THE AIRMASS LOOKS A LITTLE MORE CAPPED
PER RUC/GFS SOUNDINGS. WE DO HAVE THE WEAK SHORTWAVES IN NEBRASKA
COMING ACROSS THE FORECAST AREA AT 18Z TODAY...BUT THERE IS NO
SURFACE CONVERGENT FEATURE LIKE YESTERDAY WITH THE WARM FRONT. IN
FACT...NO SURFACE CONVERGENT FEATURES ARE PRESENT THROUGH SUNDAY
NIGHT. AFTER 06Z SUNDAY NIGHT...THERE ARE INDICATIONS OF A
SHORTWAVE COMING ACROSS SOUTHEAST MINNESOTA...AS WELL AS
ISENTROPIC LIFT ON THE 305-310 K SURFACES. THE 17.00Z GFS/CANADIAN
BOTH HINT AT POTENTIAL FOR SOME CONVECTION IN THIS AREA...SO
INCLUDED SOME 20 PERCENT CHANCES FOR NOW...GIVEN NAM/UKMET/ECMWF
DRY. FOR THE REST OF THE PERIOD...ALL MODELS ARE PRETTY MUCH DRY
THROUGH SUNDAY WHICH SEEMS REASONABLE.
MONDAY AND MONDAY NIGHT...THE UPPER TROUGHING OVER THE ROCKIES IS
FORECAST TO INCH EASTWARD...WITH ITS AXIS FROM EASTERN MONTANA INTO
NEW MEXICO AT 12Z TUESDAY. ALTHOUGH THIS TROUGH IS FAR AWAY FROM THE
AREA...WE WILL SEE 10-30 METER 500MB HEIGHT FALLS EACH 12 HOUR
PERIOD OVER THE FORECAST AREA...HIGHEST WEST. THESE HEIGHT FALLS
COMBINED WITH STRONG MOISTURE TRANSPORT ON A SOUTHERLY 40-60 KT
850MB JET WILL YIELD INCREASING PRECIPITATION CHANCES...ESPECIALLY
AGAIN OVER THE WEST. PRECIPITABLE WATER VALUES CLIMB TO 1-1.4 INCHES
WHICH WOULD SUPPORT SOME DECENT PRECIPITATION TOO. CAPE VALUES ARE
RESTRICTED SOMEWHAT DUE TO CLOUD COVER...PERHAPS UP TO 500 J/KG OF
VERY THIN MUCAPE. THIS SHOULD LIMIT THUNDER COVERAGE TOO. DESPITE
THE INCREASED CLOUD COVER AND PRECIPITATION...STILL ANTICIPATING
TEMPERATURES TO RISE INTO THE 70S ON MONDAY...WARMEST EAST WHERE
SOME SUN COULD OCCUR. LOWS STAY UP TOO MONDAY NIGHT WITH THE SURFACE
COLD FRONT STILL WAY OFF TO THE WEST IN THE EASTERN DAKOTAS.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
310 AM CDT SAT MAR 17 2012
LONG TERM FORECAST IS BECOMING MORE UNCERTAIN...PRIMARILY BECAUSE
MODELS ARE STRUGGLING ON HOW TO HANDLE THE WESTERN U.S. TROUGH FROM
MONDAY NIGHT. 17.00Z ECMWF/GFS/CANADIAN AND MOST GFS ENSEMBLES ALL
SUGGEST THE TROUGH WILL CUT-OFF AS IT CROSSES THE PLAINS TUESDAY AND
WEDNESDAY...BUT EXACTLY WHEN AND THEN HOW TO HANDLE THIS UPPER LOW
VARIES AMONG EVERY MODEL. THERE STILL REMAINS A FEW GFS ENSEMBLES
AND THE 17.00Z UKMET THAT SUGGEST THE TROUGH STAYS TOGETHER...
FOLLOWING THE 16.12Z ECMWF IDEA. HOWEVER...OVER THE LAST COUPLE DAYS
OF MODEL RUNS...THESE SEEM TO BE AN OUTLIER. THEREFORE PREFERENCE IS
TO FOLLOW THE MAJORITY 17.00Z GUIDANCE. AS THE UPPER TROUGH
APPROACHES THE FORECAST AREA TUESDAY INTO WEDNESDAY...THE MOISTURE
STREAM REFERENCED IN THE MONDAY/MONDAY NIGHT DISCUSSION WILL FULLY
SHIFT OVERHEAD. SEEMS LIKE TUESDAY NIGHT IS THE BEST PERIOD FOR THE
ENTIRE FORECAST AREA TO SEE RAIN. MODEL GUIDANCE CONSENSUS OF 60-70
PERCENT CHANCES ARE REASONABLE...BUT MAY NEED TO BE RAISED MORE IF
THIS TIME PERIOD REMAINS CONSISTENT FOR PRECIPITATION. AFTER
WEDNESDAY...ATTENTION TURNS TO THE SOUTHERN END OF THE SPLITTING
UPPER TROUGH WHICH TURNS INTO AN UPPER LOW. SOME MODELS SUGGEST THE
UPPER LOW COULD LIFT TOWARDS THE AREA ON FRIDAY. IF SO...THEN SOME
SHOWERS COULD MOVE IN. FOR NOW...HAVE LOWER 20-40 PERCENT CHANCES
FOR WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...ACCOUNTING FOR THE
DIMINISHING MOISTURE STREAM AND THE APPROACH OF THE UPPER LOW.
REGARDING THUNDER...REDUCED THESE PROBABILITIES TO 20 AND ONLY
DURING THE DAYTIME HOURS FOR TUESDAY THROUGH THURSDAY...GIVEN LESS
THAN 500 J/KG OF ONLY DAYTIME INSTABILITY SUGGESTED BY THE GFS.
TEMPERATURES THROUGHOUT MUCH OF THE LONG TERM PERIOD WILL STAY WELL
ABOVE NORMAL...UNTIL MAYBE FRIDAY NIGHT IF THE ECMWF IS RIGHT TRYING
TO SHOW SOME COLDER AIR COMING DOWN FROM CANADA. IN ANY
EVENT...850MB TEMPS DROP FROM 10-12C ON TUESDAY TO 6-8C BY 12Z
FRIDAY. A BLEND OF MODEL GUIDANCE SEEMED REASONABLE.
&&
.AVIATION...TODAY AND TONIGHT
710 AM CDT SAT MAR 17 2012
THE AREA WILL REMAIN IN SOUTHERLY AIRFLOW THROUGH THE
PERIOD...WITH GUSTY CONDITIONS EXPECTED TO DEVELOP BY LATE
MORNING AND THEN SUBSIDING AROUND SUNSET. LOOK FOR SOUTHERLY WIND
GUSTS IN THE 25-30KT RANGE. OTHERWISE...VFR CONDITION EXPECTED
THROUGH THE PERIOD. LOOK FOR SOME CUMULUS DEVELOPMENT TODAY...BUT
FAIRLY STRONG CAP ALOFT IN THE ATMOSPHERE EXPECTED TO INHIBIT DEEP
CONVECTION SHRA/TS ACTIVITY.
&&
.CLIMATE...TODAY THROUGH TUESDAY
310 AM CDT SAT MAR 17 2012
RECORD HIGHS AND RECORD WARM LOWS ARE POSSIBLE THROUGH TUESDAY...
ESPECIALLY THIS WEEKEND...AS AN UNSEASONABLY WARM AND MOIST AIR MASS
CONTINUES TO RESIDE ACROSS THE UPPER MIDWEST. TEMPERATURES SHOULD
BEGIN COOLING MON/TUE AS CLOUDS/ -SHRA INCREASE ACROSS THE AREA.
HOWEVER...RECORDS ON THOSE DAYS COMPARED TO FORECASTS STILL SUGGEST
SOME POTENTIAL TO BREAK THEM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
310 AM CDT SAT MAR 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS
CLIMATE......AJ/RRS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
622 AM CDT SAT MAR 17 2012
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY THROUGH SUNDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE WARM
FRONT LIFTING NORTHWARD OVER CENTRAL WISCONSIN EARLY THIS MORNING.
TEMPS ARE IN THE LOW TO MID 50S NORTH OF THE FRONT...AND IN THE MID
TO UPPER 60S SOUTH OF THE BOUNDARY. TEMPS ARE LOCALLY COOLER NEAR
LAKE MICHIGAN WITH SOME OF THAT MARINE AIR CURLING AROUND INTO
SHAWANO WHERE TEMPS ARE IN THE LOWER 40S WITHIN DENSE FOG. WIDELY
SCT SHOWERS AND THUNDERSTORMS THAT DEVELOPED OVER NORTH-CENTRAL
WISCONSIN HAVE BEEN WEAKENING AND WILL LIKELY EXIT THE AREA BY PRESS
TIME. ADDITIONAL ECHOES HAVE POPPED UP WITHIN THE INSTABILITY AXIS
OVER SW WISCONSIN AND NORTHWEST ILLINOIS...AND WILL ADD ISOLATED
SHOWERS AND THUNDERSTORMS NEARLY EVERYWHERE THROUGH MID-MORNING.
WITH VERY WARM AND UNSTABLE AIR MOVING INTO THE REGION TODAY...SMALL
PRECIP CHANCES ARE THE MAIN FORECAST CONCERN...FOLLOWED BY TEMPS AND
MARINE FOG.
TODAY...SURFACE WARM FRONT...WHICH SNAKES ACROSS WISCONSIN FROM NW
TO SE...WILL LIFT NORTH OF THE AREA THIS MORNING...WHICH WILL TURN
WINDS TO THE SOUTH EXCEPT ACROSS FAR NE WISCONSIN. SE WINDS
HERE...ENHANCED BY THE LAKE BREEZE THIS AFTERNOON...WILL KEEP WAVES
OF MARINE STRATUS AND FOG PROCEEDING INLAND AT TIMES.
OTHERWISE...850MB MOISTURE AND INSTABILITY AXIS WILL BE OVERHEAD
TODAY...WITH ML CAPES REACHING CLOSE TO 2500 J/KG WITH NO CIN THIS
AFTERNOON. TOUGH TO IDENTIFY A TRIGGER UPSTREAM THAT COULD TAP INTO
THIS INSTABILITY FOR THUNDERSTORM DEVELOPMENT...AND MAY JUST END UP
WITH BUBBLY CU...WHICH OCCURRED UPSTREAM TODAY. THERE ARE A COUPLE
WEAK IMPULSES UPSTREAM...OVER NW IOWA AND ANOTHER OVER WESTERN
NEBRASKA...BUT TOUGH TO SAY IF THEY WILL BE STRONG ENOUGH TO TRIGGER
CONVECTION. THE BEST THING TO LATCH ONTO IS THE SE FLOW OVER THE
DOOR...WHICH COULD GET ENHANCED BY THE LAKE BREEZE COMPONENT TO
CREATE CONVERGENCE OVER NE WISCONSIN. SYNOPTIC FLOW WILL BE OUT OF
THE SOUTH...NOT OUT OF THE SOUTHWEST OR WEST WHICH WOULD BE MORE
PREFERRED. STILL THOUGH...THAT MAGNITUDE OF CAPE CANNOT BE IGNORED
SO WILL KEEP AN ISOLATED MENTION OF SHOWERS AND THUNDERSTORMS OVER
NE WISCONSIN FOR THIS AFTERNOON. 925MB TEMPS 18C TO 20C CALL FOR
HIGHS IN THE UPPER 70S TO LOWER 80S.
TONIGHT...850MB MOISTURE AND INSTABILITY AXIS WILL REMAIN OVERHEAD.
LLJ WILL DEVELOP OVER WESTERN WISCONSIN WITH A NOSE POINTED INTO
LAKE SUPERIOR. ANY KIND OF WEAK SHORTWAVE IMPULSE COULD INITIATE
CONVECTION WITH MID-LEVEL LAPSE RATES GREATER THAN 8C...BUT TOUGH TO
IDENTIFY ANY FEATURES ON SATELLITE OR IN THE MODELS. IF SOMETHING
WERE TO POP...WESTERN WISCONSIN LOOKS BETTER ON PAPER. BUT
UNCERTAINTY IS TOO HIGH TO INCLUDE IN THE FORECAST.
OTHERWISE...SOUTH FLOW WILL AGAIN SEND WAVES OF MARINE STRATUS AND
FOG NORTH ALONG THE LAKESHORE AND ACROSS DOOR COUNTY AND FAR NE
WISCONSIN. A WARM NIGHT AHEAD WITH LOWS IN THE MID TO UPPER 50S.
SUNDAY...SHORTWAVE ENERGY WILL PASS SOUTH OF THE AREA WHILE
MID-LEVEL HEIGHTS BUILD OVERHEAD. AS A RESULT...SEEING STRONGER
CAPPING ON PROGGED SOUNDINGS WHICH SHOULD KEEP A LID ON SHOWER AND
THUNDERSTORM DEVELOPMENT. WILL GO DRY ONCE AGAIN. HIGHS AGAIN IN
THE UPPER 70S TO LOWER 80S...BUT COOLER NEAR LAKE MICHIGAN WHERE THE
ONSHORE COMPONENT WILL BE A LITTLE STRONGER.
.LONG TERM...SUNDAY NIGHT THRU FRIDAY. MAIN FORECAST CHALLENGES
ARE TEMPS...PRECIP CHANCES...AND FOG POTENTIAL.
SUMMER-LIKE PATTERN CONTINUES INTO EARLY NEXT WEEK AS UPPER RIDGE
BUILDS ACROSS THE EASTERN U.S. AND SOUTHERLY FLOW USHERS IN WARM
AIR AND RELATIVELY HIGH DEWPOINTS. TROUGH ACROSS THE WESTERN U.S.
WILL CROSS INTO THE PLAINS ON WEDNESDAY...AND TRANSITION INTO A
CUT OFF LOW THAT SLOWLY MOVES SOUTH OF THE GREAT LAKES LATE NEXT
WEEK. MODELS DISAGREE ON THE EVOLUTION FROM A LONGWAVE TROUGH TO
A CUT OFF LOW...BOTH WITH LOCATION AND TIMING...BRINGING PLENTY OF
UNCERTAINTY INTO THE FORECAST. IN GENERAL...PLAN TO FOLLOW A
GFS/ECMWF BLEND.
SUNDAY NIGHT IS STILL LOOKING DRY...AS THE AREA REMAINS UNDER
UPPER RIDGING AND NO OBVIOUS TRIGGER FOR CONVECTION. CANNOT
TOTALLY RULE OUT A STRAY SHOWER OR STORM AS STEEP LAPSE RATES
REMAIN OVER THE AREA...BUT PREFER TO STAY WITH A DRY FORECAST.
CLOUDS WILL BE ON THE INCREASE OVERNIGHT AND ON MONDAY MORNING
THOUGH...AS MOISTURE INCREASES ALOFT. WILL START TO INCREASE
POPS ON MONDAY AND MONDAY NIGHT OVER THE AREA AS UPPER TROUGH AND
SHORTWAVE ENERGY APPROACH THE AREA. STILL BELIEVE THE MAJORITY OF
THE ACTIVITY WILL STAY TO OUR WEST...WHERE THE BETTER
MOISTURE/FORCING AND BAROCLINIC ZONE IS LOCATED...BUT WILL CARRY
LOW CHANCE POPS OVER CENTRAL AND NORTH-CENTRAL WI...WITH SLIGHT
CHANCE POPS BUFFERING THIS AREA TO THE EAST. THE EXTENDED DRY
SPELL (AT LEAST FOR MOST LOCATIONS) WILL COME TO AN END TUESDAY OR
WEDNESDAY...AS THE UPPER TROUGH AND A NORTHERN PLAINS SHORTWAVE
CONVERGE ON THE AREA. POPS WILL NEED TO BE ADJUSTED FOR TUESDAY AS
THE TIMING IS PINNED DOWN...BUT PLAN TO STICK WITH CHANCE POPS
WEST AND SLIGHTS EAST TO COVER FOR NOW. HIGHEST POPS WILL BE
PLACED ON WEDNESDAY...AS THERE IS ENOUGH MODEL CONSENSUS SHOWING
PRECIP OVER THE AREA. THE UNSETTLED WEATHER LOOKS TO CONTINUE INTO
THE END OF THE WEEK AS THE UPPER LOW DRIFTS SOUTH OF THE
AREA...HOWEVER CONFIDENCE IS LOW ON THE OVERALL PATTERN. WITH
MODELS DIFFERING ON THE TIMING AND LOCATION OF THE CUT OFF
LOW...AS WELL AS A POSSIBLE SHORTWAVE OVER THE NORTHERN
PLAINS...IT WILL BE HARD TO SAY WITH CONFIDENCE WHERE THE BEST
CHANCES FOR PRECIP RESIDE AND WHEN TO GO DRY. HAVE LOW CHANCE AND
SLIGHT POPS TO COVER THIS UNCERTAINTY. DOWNPLAYED THUNDER
POTENTIAL FOR MANY OF THE PERIODS...ESPECIALLY AT NIGHT...AS
CONVECTIVE PARAMETERS ARE NOT OVERLY IMPRESSIVE.
AS FOR FOG...WILL CONTINUE TO HIGHLIGHT ON LAKE MICHIGAN AND MUCH
OF THE BAY THROUGH MID-WEEK AS UNSEASONABLY HIGH DEWPOINTS TRAVEL
ACROSS THE RELATIVELY COOLER WATERS. WILL ALSO MENTION FOG ALONG
THE IMMEDIATE SHORELINE AS ANY FOG BANK THAT DEVELOPS COULD DRIFT
INLAND. WITH DEWPOINTS IN THE 50S TO NEAR 60 THROUGH MID-
WEEK...DO EXPECT PATCHY FOG ELSEWHERE SOME NIGHTS IF WINDS CAN
DECOUPLE AND SKIES ARE CLEAR. BEST CHANCE FOR THIS WILL BE SUNDAY
NIGHT...SO WILL CONTINUE TO MENTION FOG ACROSS THE ENTIRE CWA.
WINDS LOOK TO STAY UP THE REST OF THE NIGHTS TO KEEP THE THREAT OF
FOG LOW.
RECORD OR NEAR RECORD WARMTH WILL CONTINUE ON MONDAY AND
TUESDAY AS PERSISTENT SOUTHERLY FLOW CONTINUES TO USHER IN WELL
ABOVE NORMAL TEMPS. TUESDAY LOOKS TO BE THE LAST DAY IN THE 70S
FOR PORTIONS OF CENTRAL AND EAST-CENTRAL WISCONSIN...BEFORE THE
CLOUDS AND PRECIP HOLD TEMPS IN THE MID/UPPER 50S NORTH AND LOW
60S SOUTH FOR THE END OF THE WORK WEEK. THESE MAY BE A LITTLE
GENEROUS IF PRECIP/CLOUD COVER ARE WIDESPREAD ENOUGH. ALTHOUGH
TEMPS WILL BE SIGNIFICANTLY COOLER LATE IN THE WEEK COMPARED TO
EARLY IN THE WEEK...THEY WILL REMAIN ABOVE NORMAL.
&&
.AVIATION...WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ARE MAKING
THERE WAY EAST ACROSS THE EASTERN HALF OF WISCONSIN THIS MORNING.
THESE STORMS ARE EXPECTED TO DISSIPATE BY LATE MORNING. PATCHY
MVFR VSBYS IN MIST OVER NORTH-CENTRAL WISCONSIN WILL QUICKLY TURN
VFR WITH DAYTIME HEATING AN HOUR OR TWO AFTER THE 12Z ISSUANCE.
OTHERWISE VFR CONDITIONS THROUGH THE TAF PERIOD. LLWS DEVELOPS
AGAIN TONIGHT OVER NORTH-CENTRAL WISCONSIN.
MPC
&&
.MARINE...AREAS OF DENSE MARINE FOG SEEM MOST CONCENTRATED ADJACENT
TO THE DOOR PENINSULA...AND THE CENTRAL AND NORTHERN PORTIONS OF
GREEN BAY. WITH COORD FROM MKX...WILL CANCEL THE MARINE DENSE FOG
ADVISORY FOR AREAS SOUTH OF THE DOOR. WILL LEAVE A MENTION OF
PATCHY DENSE FOG THROUGH SUNDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
230 PM PDT SAT MAR 17 2012
.SYNOPSIS...
A COLD AND UNSTABLE MOIST AIRMASS WILL AFFECT THE AREA THROUGH
SUNDAY...WITH SCATTERED SHOWERS...A SLIGHT CHANCE OF THUNDERSTORMS
AND MOUNTAIN SNOW. SNOW LEVELS ARE EXPECTED TO LOWER OVERNIGHT WHICH
MAY AFFECT THE ANTELOPE VALLEY FOOTHILLS...AS WELL AS THE INTERIOR
SAN LUIS OBISPO AND CUYAMA VALLEYS. TEMPERATURES WILL REMAIN WELL
BELOW NORMAL THROUGH EARLY NEXT WEEK.
&&
.SHORT TERM (TODAY-TUE)...THE BULK OF THE PRECIPITATION HAD EXITED
THE EAST PORTION OF LA COUNTY EARLY THIS AFTERNOON THOUGH PICTURES
FROM SPACE INDICATED A RELATIVELY LARGE OPEN CELL CUMULUS FIELD IN
THE VICINITY AND UPSTREAM OF THE TROUGH AXIS CENTERED OVER THE
OFFSHORE WATERS. GOES SOUNDER AND RUC INDICATED NEGATIVE LI`S OVER
THE OFFSHORE WATERS NORTH OF POINT CONCEPTION AND THE INSTABILITY
WAS GRADUALLY APPROACHING THE AREA. STABILITY WILL DECREASE THROUGH
THE EVENING AND THE RUC INDICATED MINUS 3.5 LI`S LATER THIS EVENING.
UNSTABLE AIR MASS WILL PERSIST OVER THE AREA THROUGH SUNDAY AND A
THREAT OF THUNDERSTORMS AND SHOWERS WILL EXIST. SHOWERS AND
THUNDERSTORMS WILL MOVE EAST THROUGH THE EVENING AND THEN MOVE
SOUTHEAST OVERNIGHT THROUGH SUNDAY. OTHERWISE GUIDANCE DIFFERED FROM
PREVIOUS RUNS AND BETWEEN SUITES WITH THE APPROACHING TROUGH
CURRENTLY NEAR 41/143. WILL CONTINUE WITH SLIGHT CHANCE OF LIGHT
PRECIPITATION AS WARM FRONT LIKE BOUNDARY WITH WEAK ASCENDING
NORTHWEST FLOW APPROACHES. WILL CONTINUE THE WARMING TREND MONDAY
THROUGH TUESDAY THOUGH TEMPERATURES WILL LIKELY BE 5 TO 15 DEGREES
BELOW SEASONAL NORMAL MONDAY AND AROUND 5 DEGREES BELOW NORMAL
TUESDAY.
.LONG TERM (WED-SAT)...HAVE ADDED A CHANCE OF LIGHT PRECIPITATION
NEXT SATURDAY. THERE IS A CHANCE A SURFACE FRONT WILL NOT DISSIPATE
UPSTREAM FROM THE AREA AND MOVE ASHORE NEXT SATURDAY. ECM AND GFS
OPERATIONAL GUIDANCE WERE RELATIVELY CONSISTENT AS WAS THE GFS
ENSEMBLE WITH PREVIOUS RUNS AND INDICATED A SURFACE FRONT MOVING
ASHORE. OTHERWISE A WARMING TREND WILL CONTINUE WEDNESDAY WITH
TEMPERATURES SEVERAL DEGREES ABOVE NORMAL THEN A GRADUAL COOLING
TREND IS EXPECTED AS ONSHORE FLOW INCREASES AND HEIGHTS/THICKNESSES
FALL/LOWER OVER THE AREA AHEAD OF THE APPROACHING AND LANDFALLING
FRONT THURSDAY THROUGH SATURDAY.
&&
.AVIATION...16/1755Z...
LOW CLOUDS ACROSS COAST AND VALLEY AREAS WILL BEGIN TO BREAK OUT
THIS AFTERNOON. CIGS WILL LIFT INTO THE HIGH MVFR CATEGORY AND THERE
IS A CHANCE THAT MANY SITES WILL SCATTER OUT...ESPECIALLY S OF PT
CONCEPTION...BEFORE LOW CLOUDS FILL IN AGAIN DURING THE EVENING.
A FRONTAL SYSTEM WILL SPREAD INCREASING CLOUDS AND RAIN ACROSS THE
AREA FROM NW TO SE TONIGHT INTO SAT...DEVELOPING ACROSS SLO AND SBA
COUNTIES BETWEEN MIDNIGHT AND 5 AM...AND REACHING LOS ANGELES COUNTY
BY MID MORNING SATURDAY. GUSTY S-SE WINDS WILL AFFECT MANY AIRFIELDS
BETWEEN THE HOURS OF 06Z-10Z N OF PT CONCEPTION...TO 10Z-13Z FURTHER
SOUTH. THE EXCEPTION WILL BE IN THE DESERT AIRFIELDS WHERE GUSTY SW
WINDS ARE EXPECTED THROUGH MOST OF THE FORECAST PERIOD.
KLAX...LOWER TO MODERATE CONFIDENCE IN TAF. THERE IS A 40 PERCENT
CHANCE THAT MVFR CIGS WILL SCATTER OUT AFTER 20Z. THERE IS A 30
PERCENT CHANCE THAT LOWER CIGS WILL RETURN +/- 2 HOURS FROM TAF TIME
OF 04Z...OR THAT CIGS WILL BE IN THE MVFR CATEGORY THROUGH LATE
TONIGHT. THERE IS A 20 TO 30 PERCENT CHANCE THAT EAST WINDS WILL
EXCEED 10 KNOTS AS EARLY AS 10Z SAT.
KBUR...MODERATE CONFIDENCE IN TAF. THERE IS A 40 PERCENT CHANCE THAT
MVFR CIGS WILL SCATTER OUT AFTER 20Z. THERE IS A 30 PERCENT CHANCE
THAT MVFR CIGS WILL RETURN +/- 2 HOURS FROM TAF TIME OF 04Z.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING (SEE LAXWSWLOX).
WIND ADVISORY (SEE LAXNPWLOX).
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH SURF ADVISORY (SEE LAXCFWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
&&
$$
PUBLIC...30
AVIATION...SMITH
SYNOPSIS...BARTLING
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
144 PM EDT SAT MAR 17 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL EXTEND ACROSS THE REGION TONIGHT. A
BACKDOOR COLD FRONT WILL MOVE SOUTH INTO THE AREA THIS WEEKEND
AND DISSIPATE EARLY NEXT WEEK. ATLANTIC HIGH PRESSURE WILL THEN
REGAIN CONTROL OF THE PATTERN THROUGH MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN CHANGE TO THE PREVIOUS FORECAST WAS TO PUSH RAIN CHANCES BACK
A BIT MORE TOWARD EVENING. DECENT BATCH OF MID LEVEL CLOUDS OVER
MOST OF THE FORECAST AREA HAS KEPT TEMPERATURES DOWN A TAD AND
THIS IS SLOWING DESTABILIZATION. ALSO NOTICED SLIGHTLY WARMER 500
MB TEMPS THIS AFTERNOON ACROSS THE INTERIOR AS PER LATEST RUC AND
THIS IS LIKELY ALSO CONTRIBUTING TO SLOWER CONVECTIVE DEVELOPMENT.
OTHERWISE... SEE PREVIOUS DISCUSSION FOR MORE DETAILS ON
CONVECTIVE EVOLUTION/SEVERE WX THREAT LATER THIS AFTERNOON/EVENING.
===============================================================
== DISCUSSION FOR CHATHAM COUNTY EMERGENCY MANAGEMENT AGENCY ==
===============================================================
ANOTHER ACTIVE DAY FOR SHOWERS AND TSTMS AROUND THE SAVANNAH
METRO AREA LATE THIS AFTERNOON AND EVENING. INITIALLY... MOST OF
THE ACTIVITY IS EXPECTED TO FIRE JUST WEST OF THE CITY ALONG THE
INLAND MOVING SEA BREEZE...BUT COULD PUSH BACK TOWARD THE DOWNTOWN
AREA LATE IN THE AFTERNOON INTO THIS EVENING. THE TIME FOR
GREATEST IMPACTS APPEARS TO BE FROM 1700-2200 EDT. CONDITIONS WILL
FAVOR WINDS IN EXCESS OF 40 MPH...PENNY SIZE HAIL AND FREQUENT
CLOUD-TO- GROUND LIGHTNING WITH ANY TSTMS THAT DEVELOP TODAY. A
SEVERE TSTM IS ALSO POSSIBLE WITH HAIL 1 INCH OR LARGER AND/OR
DAMAGING WINDS IN EXCESS OF 60 MPH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
TONIGHT...CLUSTERS OF STRONG TO SEVERE TSTMS WILL LIKELY BE
ONGOING AFTER SUNSET AS BOTH INSTABILITY AND LOW-LEVEL CONVERGENCE
ALONG MESOSCALE BOUNDARIES PEAK. ACTIVITY WILL GRADUALLY WIND DOWN
THROUGH THE EVENING AND OVERNIGHT...BUT IT WILL LIKELY TAKE A GOOD
PORTION OF THE NIGHT FOR ACTIVITY TO DISSIPATE. WILL SHOW LIKELY
TO CHANCE POPS ALL AREAS THIS EVENING WITH RAIN CHANCES
DIMINISHING OVERNIGHT. LOWS WILL RANGE FROM THE UPPER 50S INLAND
TO THE LOWER 60S AT THE BEACHES AND DOWNTOWN CHARLESTON. /ST
SUNDAY AND MONDAY...UPPER LEVEL RIDGING EXTENDING FROM THE GULF
OF MEXICO WILL SHIFT TOWARD THE EAST COAST AND BECOME MORE
AMPLIFIED EARLY NEXT WEEK. THE MAIN SURFACE FEATURE DRIVING MUCH
OF THE SENSIBLE WEATHER SUNDAY AND MONDAY WILL BE A BACKDOOR FRONT
DESCENDING SOUTHWARD INTO THE FORECAST AREA. MOISTURE AND
CONVERGENCE IN THE VICINITY OF THIS FRONT...WHEN COMBINED WITH
DIURNAL INSTABILITY AND SEABREEZE FORCING...WILL MAINTAIN RAIN
CHANCES BOTH SUNDAY AND MONDAY.
ALTHOUGH THERE REMAINS SOME DISAGREEMENT AMONG NUMERICAL MODEL
SOLUTIONS REGARDING THE SOUTHWARD PROGRESSION OF THE FRONT...THERE
IS A GENERAL CONSENSUS THAT THE FEATURE WILL AT LEAST SLIP INTO
THE CHARLESTON TRI COUNTY REGION ON SUNDAY...BEFORE BECOMING
DIFFUSE AND DISSIPATING LATE SUNDAY INTO MONDAY. DESPITE LITTLE TO
NO DYNAMICS ALOFT AND WEAK VERTICAL SHEAR...THERE WILL BE
SUFFICIENT MOISTURE CONVERGENCE AND INSTABILITY TO SUPPORT
ISOLATED TO SCATTERED DIURNAL CONVECTION GENERALLY AHEAD OF THE
SEABREEZE DURING THE AFTERNOON HOURS.
THE CHARLESTON TRI COUNTY AREA AGAIN APPEARS TO BE THE MOST
FAVORED LOCATION FOR CONVECTIVE COVERAGE ON SUNDAY...AS IT REMAINS
CLOSEST TO THE BOUNDARY AND ANY ASSOCIATED WEAK WAVE OF LOW
PRESSURE. HAVE INDICATED POPS IN THE 30 PERCENT RANGE FOR MOST
INLAND AREAS NORTH OF INTERSTATE 16...WITH NEAR 40 PERCENT CHANCES
IN THE FAR NORTHWEST TIER ZONES. SINCE THE FRONT WILL BE MORE
DIFFUSE ON MONDAY AND COULD PROVIDE LESS FOCUS FOR CONVECTION THAN
THE SEABREEZE...HAVE JUST INDICATED SLIGHT CHANCE POPS AWAY FROM
THE COAST MONDAY AFTERNOON. HAIL WOULD AGAIN BE THE MAIN RISK
WITHIN STRONGEST THUNDERSTORMS...ESPECIALLY CONSIDERING UNSEASONABLY
LOW 500 MB TEMPERATURES WITHIN A PERSISTENT COLD POOL ALOFT.
A SUBTLE HIGH TEMPERATURE GRADIENT COULD DEVELOP BOTH SUNDAY AND
MONDAY DEPENDING ON THE LOCATION OF THE BACKDOOR FRONT. HOWEVER
THE BOUNDARY IS EXPECTED TO HAVE LITTLE OVERALL IMPACT ON THE
UNSEASONABLY WARM CONDITIONS...WITH HIGH TEMPERATURES RANGING FROM
THE UPPER 70S CHARLESTON TRI COUNTY REGION TO THE LOW TO MID 80S
AWAY FROM THE COAST ELSEWHERE.
TUESDAY...A MORE SOLID ONSHORE FLOW WILL DEVELOP BY TUESDAY...AS
ATLANTIC HIGH PRESSURE BUILDS FROM THE NORTH. THE RESIDUAL FRONT
AND WAVE OF LOW PRESSURE WILL RESEMBLE MORE OF A COASTAL TROUGH
FEATURE...PUSHING ONSHORE FROM THE WESTERN PERIPHERY OF THE
ATLANTIC HIGH. EXPECT ENOUGH ATLANTIC MOISTURE AND FORCING FROM
THE WEAK TROUGH TO SUPPORT ISOLATED SHOWERS/THUNDERSTORMS TUESDAY
AFTERNOON...YET WITH LESS COVERAGE EXPECTED THAN PREVIOUS DAYS.
HIGH TEMPERATURES COULD BE JUST A DEGREE OR TWO COOLER WITHIN THE
ONSHORE FLOW...WHILE STILL GENERALLY RANGING FROM THE UPPER 70S TO
LOWER 80S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
BROAD UPPER RIDGING AND ATLANTIC SURFACE HIGH PRESSURE WILL
REMAIN IN CONTROL THROUGH MID WEEK...BEFORE THE FORECAST BECOMES
MORE UNCERTAIN INTO THE LATE WEEK PERIOD. MID RANGE MODELS
INDICATE A DEEP UPPER TROUGH STEADILY PROGRESSING TOWARD THE EAST
COAST THURSDAY...POSSIBLY CUTTING OFF INTO A BROAD UPPER LOW BY
FRIDAY. THIS COULD DRIVE A SURFACE FRONT TOWARD THE REGION AND
INCREASE RAIN CHANCES LATE IN THE WEEK. CONFIDENCE IN FORECAST
DETAILS THURSDAY AND FRIDAY IS QUITE LOW AT THIS TIME HOWEVER...AS
THERE IS CONSIDERABLE TIMING DIFFERENCES BETWEEN MODEL SOLUTIONS.
HAVE THUS PREFERRED TO REMAIN RATHER CONSERVATIVE WITH RAIN
CHANCES THIS FAR OUT IN THE FORECAST PERIOD...CAPPING POPS BELOW
15 PERCENT UNTIL MODEL CONSENSUS IMPROVES. HAVE ALSO CONTINUED TO
ADVERTISE ABOVE NORMAL TEMPERATURES...REACHING AT LEAST THE MID TO
UPPER 70S INTO THE WEEKEND AWAY FROM THE LOCALLY COOLER COASTLINE.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
SHOWERS/TSTMS APPEAR TO BE THE MAIN IMPACT TO AVIATION THIS
PERIOD. LATEST THINKING IS THAT SHOWERS AND THUNDERSTORMS WILL
DEVELOP ALONG THE INLAND MOVING SEA BREEZE THIS
AFTERNOON...POSSIBLY COLLIDING WITH ACTIVITY FARTHER WEST...THEN
POSSIBLY MOVING BACK TOWARD THE COAST TOWARD EVENING. HAVE
MAINTAINED TSRA AT KSAV BUT PUSHED BACK THE TIMING A BIT AS
CONVECTION APPEARS TO BE A BIT SLOWER THAN YDAY.
OTHERWISE...POSSIBLE MVFR FOG TOWARD DAYBREAK BUT CHANCES TOO LOW
TO MENTION ATTM.
EXTENDED AVIATION OUTLOOK...ELEVATED POTENTIAL FOR LATE
NIGHT/EARLY MORNING FOG AND/OR LOW CEILINGS INTO EARLY NEXT WEEK.
&&
.MARINE...
QUIET MARINE CONDITIONS THROUGH TONIGHT...ALTHOUGH TSTMS COULD
POSE A RISK FOR MARINERS CLOSER TO THE BEACHES LATE THIS AFTERNOON
AND EVENING. WINDS WILL GENERALLY BE 10 KT OR LESS WITH SEAS 3 FT
OR LESS.
SUNDAY THROUGH WEDNESDAY...THE BACKDOOR COLD FRONT WILL LIKELY
SLIP INTO THE SOUTH CAROLINA WATERS ON SUNDAY. THE PRESSURE
GRADIENT WILL REMAIN RATHER WEAK AS THIS FEATURE MOVES INTO THE
AREA...AND EXPECT LIGHT WIND FIELDS TO POTENTIALLY BE QUITE
VARIABLE THROUGH MONDAY. ONCE THE FRONT BECOMES DIFFUSE AND
DISSIPATES ON MONDAY...ATLANTIC HIGH PRESSURE WILL BUILD FROM THE
NORTH AND BECOME THE DOMINATE FEATURE THROUGH THE REMAINDER OF THE
PERIOD. THIS WILL SUPPORT SLIGHTLY STRONGER ONSHORE FLOW...YET
EXPECT WINDS SPEEDS TO REMAIN 15 KT OR LESS TUESDAY AND WEDNESDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
137 PM EDT SAT MAR 17 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED OFF THE ATLANTIC COAST WILL BE THE MAIN
WEATHER FEATURE ACROSS THE REGION TODAY. A WEAK COLD FRONT WILL
DRIFT SOUTHWARD AND DISSIPATE OVER THE REGION SUNDAY. HIGH
PRESSURE WILL REGAIN CONTROL THROUGH THE MIDDLE OF NEXT WEEK.
TEMPERATURES WILL REMAIN ABOVE NORMAL.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR CURRENTLY NOT INDICATING RETURNS OVER OUR FA. SATELLITE/SURFACE
OBS NOT INDICATING CU YET EITHER. LATEST RUC SOUNDINGS AND SPC
MESOANALYSIS PAGE INDICATING SOME LOW LEVEL CAPPING AND NEGATIVE
AREA THAT NEEDS TO BE OVERCOME BEFORE ANY CONVECTION DEVELOPS.
STILL EXPECTING SCATTERED CONVECTION TO DEVELOP LATER THIS
AFTERNOON THOUGH ONCE FORECAST CONVECTIVE TEMPS REACHED AND SOME
LIFT ENCOUNTERED ALONG ANY BOUNDARIES. WHAT DOES DEVELOP COULD
POTENTIALLY BE STRONG WITH GUSTY WINDS/HAIL POSSIBLE.
THUNDERSTORMS WILL DIMINISH DURING THE EVENING AND OVERNIGHT WITH
SLIGHT CHANCE POPS AFTER MIDNIGHT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
A WEAK BACK DOOR COLD FRONT IS EXPECTED TO MOVE INTO THE NORTHERN
MIDLANDS ON SUNDAY...AND ALTHOUGH QUITE DIFFUSE...MAY BECOME A
FOCUS FOR CONVECTION AS LOW LEVEL CONVERGENCE LIKELY ENHANCED. AIR MASS
WILL BE WEAKLY TO MODERATELY UNSTABLE WITH PRECIPITABLE WATER OVER
AN INCH. WILL KEEP CHANCE OF SHOWERS AND THUNDERSTORMS FOR
SUNDAY...MAINLY DIURNAL. LARGE SPREAD IN THE POP GUIDANCE AND
CONFIDENCE REMAINS SOMEWHAT LOW...BUT WILL CONTINUE WITH GENERALLY
CHANCE POPS. TEMPS REMAIN ABOVE NORMAL...OVERNIGHT MINIMUM
TEMPERATURES ABOVE GUIDANCE DUE TO BIAS.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
UPPER RIDGE AND SURFACE HIGH PRESSURE HOLDS ACROSS THE EASTERN U.S.
THROUGH MOST OF THE LONG TERM UNTIL LATE WEEK WHEN UPPER LEVEL LOW
PRESSURE SLOWLY APPROACHES FROM THE MISSISSIPPI VALLEY. ANOMALOUSLY
HIGH HEIGHTS WITH ABOVE NORMAL TEMPERATURES ARE EXPECTED ACROSS
THE REGION. ENSEMBLE POPS ARE AT OR BELOW AVERAGE THROUGH MID
WEEK...SO WILL KEEP THE FORECAST MAINLY DRY UNTIL TOWARD END OF
PERIOD WHEN UPPER LOW APPROACHES.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS WITH LIGHT AND VARIABLE WINDS EXPECTED...OUTSIDE ANY
SHOWER OR POSSIBLE THUNDERSTORM ACTIVITY THAT MAY DEVELOP LATE THIS
AFTERNOON INTO EARLY THIS EVENING. WILL HANDLE WITH VCSH AND CB
CLOUD GROUP IN THE TAFS FOR NOW. FOG POTENTIAL FOR LATE
TONIGHT/SUNDAY MORNING WILL BE DEPENDENT ON CLOUD COVER.
SINCE CONFIDENCE LIMITED AT THIS TIME...WILL NOT MENTION FOG.
EXTENDED AVIATION OUTLOOK...MVFR OR IFR CONDITIONS MAY OCCUR IN LATE
NIGHT/MORNING FOG THROUGH EARLY NEXT WEEK. SCATTERED AFTERNOON
SHOWERS OR A POSSIBLE THUNDERSTORM SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1233 PM CDT SAT MAR 17 2012
.DISCUSSION...
ISSUED 1031 AM CDT SAT MAR 17 2012
FOG HAS BEEN SLOW TO DISSIPATE ACROSS CENTRAL ILLINOIS THIS
MORNING...WITH 15Z SATELLITE IMAGERY/SURFACE OBS INDICATING
FOG/LOW OVERCAST PERSISTING BETWEEN THE ILLINOIS RIVER VALLEY
AND THE I-55 CORRIDOR. VISBYS ARE NOW RAPIDLY IMPROVING...SO FOG
SHOULD NO LONGER BE AN ISSUE BY MIDDAY.
MID-LEVEL SHORT-WAVE EVIDENT ON WATER VAPOR IMAGERY OVER
KANSAS/OKLAHOMA WILL BE THE MAIN WEATHER-MAKER THIS AFTERNOON.
THIS FEATURE IS EXPECTED TO INTERACT WITH A VERY MOIST AND
INCREASINGLY UNSTABLE AIRMASS TO PRODUCE SCATTERED THUNDERSTORMS
ACROSS THE AREA. LATEST RADAR MOSAIC IS ALREADY SHOWING CONVECTION
DEVELOPING AHEAD OF THE WAVE FROM CENTRAL MISSOURI SOUTHEASTWARD
INTO WESTERN KENTUCKY. 12Z HRRR HAS A GOOD HANDLE ON THE CURRENT
SITUATION AND SHOWS THE CONVECTION TRACKING INTO CENTRAL ILLINOIS
AFTER 18Z. BASED ON LATEST TRENDS...HAVE MADE A FEW CHANGES TO THE
FORECAST...MAINLY TO INCREASE POPS INTO THE LIKELY CATEGORY ACROSS
THE S/SW KILX CWA. HAVE ALSO LOWERED AFTERNOON HIGHS BY A FEW
DEGREES DUE TO THE EXPECTED INCREASE IN CONVECTION. READINGS WILL
STILL REACH THE 80 DEGREE MARK ALONG/NORTH OF THE I-74 CORRIDOR...BUT
SHOULD STAY IN THE 70S FURTHER S/SW DUE TO CLOUDS/PRECIP.
&&
.AVIATION...
ISSUED 1233 PM CDT SAT MAR 17 2012
MID-LEVEL WAVE CURRENTLY LIFTING NORTHEASTWARD INTO MISSOURI WILL
TRIGGER SCATTERED THUNDERSTORMS ACROSS CENTRAL ILLINOIS LATER THIS
AFTERNOON AND EVENING. BASED ON RADAR TIMING TOOLS...CONVECTION
AROUND KCOU WILL ARRIVE AT KSPI BETWEEN 21 AND 22Z. DUE TO
UNCERTAINTIES ASSOCIATED WITH CONVECTIVE DEVELOPMENT/LIFE
CYCLE...HAVE OPTED TO MAINTAIN VCTS AT THE TAF SITES UNTIL RADAR
TRENDS DICTATE PREDOMINANT THUNDER. USING RADAR DATA AND HRRR/NAM
FORECAST...HAVE GIVEN ALL TERMINALS A 4 TO 6 HOUR WINDOW FOR
POTENTIAL THUNDER BETWEEN 21Z AND 05Z. AFTER THAT...BEST FOCUS FOR
ADDITIONAL THUNDER SHIFTS FURTHER NORTH/EAST OUT OF THE AREA.
WINDS WILL BE FROM THE SOUTH THIS AFTERNOON AND MAY GUST TO
BETWEEN 15 AND 20KT AS MIXING OCCURS. GUSTINESS WILL SUBSIDE THIS
EVENING...WITH S/SW WINDS AT AROUND 10KT CONTINUING INTO SUNDAY
MORNING.
BARNES
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT SAT MAR 17 2012
SHORT TERM...TODAY THROUGH TUESDAY
UNSEASONABLY WARM WEATHER STILL EXPECTED TO CONTINUE THROUGH AT
LEAST TUE WITH MORE RECORD HIGHS POSSIBLY TIED OR BROKEN.
CONVECTION CHANCES IS THE FORECAST CHALLENGE NEXT SEVERAL DAYS.
SHORT WAVE EJECTING NE TOWARD IL/MO BORDER BY SUNSET WILL INCREASE
CHANCES OF SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON
ESPECIALLY SOUTH OF I-72 AND CONTINUE CHANCES TONIGHT. SPC KEEPS
SLIGHT RISK OF SEVERE STORMS OVER FAR SOUTHERN IL INTO SE MO...
NORTHERN AR AND WESTERN PARTS OF KY/TN. ISOLATED SHOWERS AND
THUNDERSTORMS RECENTLY DEVELOPED OVER NW IL/SW WI NORTH OF I-80
AND WEST OF I-39 AND DRIFTING NE AWAY FROM CENTRAL IL. PATCHY FOG
DEVELOPING OVER SOUTHEAST IL ALONG HIGHWAY 50 WITH LAWRENCEVILLE
VSBY DOWN TO 1/2 MILE. MAY NEED TO ADD PATCHY FOG INTO MID MORNING
OVER AREAS SE OF I-70. NEAR RECORD HIGHS AROUND 80F ON THIS ST
PATRICKS DAY AND RECORD HIGHS LIKELY IN THE LOWER 80S SUNDAY WITH
JUST A 20-30% CHANCE OF SHOWERS AND THUNDERSTORMS OVER EASTERN IL
SUNDAY MORNING WITH MOSTLY CLOUDY SKIES BECOMING PARTLY TO MOSTLY
SUNNY SUNDAY AFTERNOON AS SHORT WAVE DEPARTS IL. DRY CONDITIONS
EXPECTED SUNDAY NIGHT.
DEEPENING UPPER LEVEL TROF OVER THE ROCKIES EARLY NEXT WEEK WITH
STRONG UPPER LEVEL RIDGE OVER THE EASTERN STATES. THIS TO CONTINUE
UNSEASONABLY WARM HIGHS IN THE UPPER 70S AND LOWER 80S MON/TUE
WITH MORE RECORD HIGHS LIKELY TIED OR BROKEN. HAVE 20-30% CHANCE
OF SHOWERS/THUNDERSTORMS MON-TUE WEST OF I-55 CLOSER TO UPPER
LEVEL TROF AND EJECTING SHORT WAVES OVER THE GREAT PLAINS AND
TOWARD THE MS VALLEY. EASTERN IL SHOULD GENERALLY STAY DRY AND
WARM DURING THIS TIME. SPC HAS SLIGHT RISK OF SEVERE STORMS WEST
OF IL MON AND MON NIGHT WHERE BETTER CHANCES OF THUNDERSTORMS WILL
BE.
LONG TERM...TUESDAY NIGHT THROUGH FRIDAY NIGHT
CHANCES OF SHOWERS AND THUNDERSTORMS INCREASE FROM WEST TO EAST
FROM TUE NIGHT THROUGH THU AS STRONG UPPER LEVEL TROF/LOW SHIFTS
EAST TOWARD THE MS VALLEY. HAVE LIKELY POPS OVER FAR WESTERN AREAS
TUE NIGHT AND INTO WESTERN AND SW AREAS BY WED NIGHT FROM PEORIA
TO TAYLORVILLE WEST. UPPER LEVEL TROF/LOW TO BE NEAR IL THU
WITH COOLER WEATHER AND CONTINUE CHANCES OF SHOWERS AND POSSIBLE
THUNDERSTORMS. UPPER LEVEL TROF/LOW SHIFTS EAST OF IL FRI WITH BEST
CHANCE OF SHOWERS/THUNDERSTORMS SHIFTING EAST OF IL INTO INDIANA AND
TEMPS COOLER FURTHER LATE NEXT WEEK.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
435 PM EDT SAT MAR 17 2012
.UPDATE...
ISSUED AT 435 PM EDT SAT MAR 17 2012
SFC BASED INSTABILITY STILL INCREASING OVER THE AREA TO THE POINT OF
LOOKING AT A FEW...SHORT LIVED...ISOLATED SHOWERS POPPING AROUND
NERN KY WITH NO LIGHTNING ATTM. MORE ROBUST ACTIVITY OVER NRN/CENTRAL
TN WOULD BE MOVING INTO OUR CUMBERLAND COUNTIES IN THE NEXT FEW HOURS
WHERE LAPS AND SPC MESO ANALYSIS SHOWS SBCAPE CLIMBING TO AROUND
2-3K. GIVEN THE WEAK KINEMATIC FIELDS...NOT EXPECTING ANYTHING TOO
STRONG BUT SLOW MOVING HEAVY RAINERS COULD POSE SOME SHORT TERM HYDRO
PROBLEMS LATER THIS EVENING. WILL DEFINITELY KEEP A CLOSE EYE ON THIS
ACTIVITY AND UPDATE PRIOR TO 00Z IF NECESSARY. OTW...THE CURRENT
FORECAST APPEARS TO HAVE A GOOD HANDLE ON THE SITUATION AND NO MAJOR
CHANGES ARE NEEDED ATTM.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 351 PM EDT SAT MAR 17 2012
CURRENT CONDITIONS ACROSS THE AREA AS OF 19Z HAS A ROBUST CU FIELD
DEVELOPING OVER CENTRAL KENTUCKY EXTENDING INTO THE BLUE GRASS
COUNTIES AND ALONG THE I-75 CORRIDOR. SO FAR TODAY...ONLY A FEW
SHOWERS HAVE DEVELOPED AND JUDGING BY WHATS GOING ON UPSTREAM...THE
WEAK WAVE PICKED OUT IN THE RUC AND SREF...HAS ONLY BEEN ABLE TO GEN
UP A FEW SHOWERS. IT SEEMS WE WILL HAVE TO WAIT TILL TONIGHT FOR THE
STRONGER WAVE OUT IN WESTERN KENTUCKY TO MOVE INTO THE OUR CWFA TO
PRODUCE ANY SHOWERS AND THUNDERSTORMS. BY THIS POINT...THE
INSTABILITY TO WORK WITH FROM THE DAY WILL HAVE BEEN PRETTY MUCH CUT
OFF SO EXPECTING JUST SOME RUN OF THE MILL SHOWERS AND THUNDERSTORMS
THIS EVENING AND TONIGHT.
WITH AMPLE MOISTURE FROM THE GULF CONTINUING...THE WAVE MOVING
THROUGH TONIGHT WILL PRODUCE THE CHANCE FOR SHOWERS AND
THUNDERSTORMS THROUGH SUNDAY NIGHT. WATER VAPOR ALSO HINTED AT A
STRONG MOISTURE FLUX IN FROM THE BAJA REGION WITH A FEW EMBEDDED
WAVES AND THEREFORE A PROLONGED PERIOD OF PERIODIC SHOWER AND
THUNDERSTORM ACTIVITY THROUGH SUNDAY NIGHT SEEMS LIKELY. BY DAYTIME
HEATING FOR SUNDAY...SHOWER AND THUNDERSTORM ACTIVITY SHOULD
PERSIST. AT THIS POINT...DUE TO THE INCH AND A TENTH
PWATS...THINKING THAT RAINFALL DURING THIS PERIOD WILL BE THE ONLY
FACTOR TO MONITOR CLOSELY. THE CONTINUED CLOUD COVER OVER THE AREA
WILL KEEP THE THREAT OF STRONG STORMS IN CHECK BUT STORMS WITH HEAVY
RAINFALL WILL STILL BE POSSIBLE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 351 PM EDT SAT MAR 17 2012
THE MODELS BEGIN THE EXTENDED PORTION OF THE FORECAST IN DECENT
AGREEMENT ALOFT. THEY ALL HAVE THE FULL LATITUDE WESTERN TROUGH
DESCENDING AND DEEPENING INTO A CUT OFF LOW OVER NORTHERN TEXAS
DURING THE DAY TUESDAY. THIS RESULTS IN A STRONG DOWNSTREAM RIDGE
BUILDING OVER THE APPALACHIANS FROM MONDAY INTO TUESDAY NIGHT.
AROUND THIS TIME...THOUGH...THE MODELS START TO DIVERGE FROM EACH
OTHER WITH RESPECT TO THE THIS KEY FEATURE. THE ECMWF AND GEM MOVE
THE LOW EASTWARD QUICKER THAN THE GFS AND THIS DIFFERENCE CONTINUES
INTO THE DAY THURSDAY AS IT PIVOTS OVER THE MID MISSISSIPPI
VALLEY AND STARTS TO ENCROACH ON THE OHIO AND TENNESSEE VALLEYS. BY
THIS TIME THE WEAKER ECMWF IS ABOUT 200 MILES EAST OF THE GFS AND
THE GEM ABOUT THE SAME DISTANCE TO THE SOUTHEAST. GIVEN THE MID
LEVEL JET RUNNING SOUTHWEST TO NORTHEAST THROUGH THE MIDDLE OF THE
CONTINENT...PREFER THE SLOWER GFS IN THIS CUTOFF FAVORING FLOW
PATTERN. AS THE UPPER LOW SLOWLY CROSSES THE MISSISSIPPI RIVER AND
MOVES OVER WESTERN TENNESSEE AND KENTUCKY...THE ECMWF WILL START TO
RETROGRADE. AS A RESULT...BY FRIDAY EVENING THEY HAVE A SIMILAR
MAGNITUDE AND PLACEMENT FOR THE LOW...PRETTY MUCH CENTERED OVER EAST
KENTUCKY. FURTHER NORTH...THOUGH...THEY DIFFER ON THE MAGNITUDE OF A
TROUGH IN THE JET STREAM SO THAT EVEN THE SIMILARITIES OVER OUR AREA
TO END THE WEEK DOES NOT ENHANCE CONFIDENCE. THE MODELS THEN TAKE
THE REMAINS OF THEIR LOWS SLOWLY EAST THROUGH THE APPALACHIANS AND
TO THE EAST COAST...AS RIDGING BUILDS INTO THE PLAINS. DUE TO LOW
CONFIDENCE WITH HOW THE UPPER LOW IS FINALLY KICKED OUT OF THE
REGION WILL DOWN PLAY THIS POTENTIAL FOR NOW.
SENSIBLE WEATHER WILL FEATURE A CONTINUATION OF OUR RECENT HEAT
WAVE. THERE WILL BE A LULL IN THE SHOWERS AND STORMS OF THE PAST FEW
DAYS ON MONDAY AS THE UPPER RIDGE BUILDS ENOUGH TO CAP SUPPRESS ANY
CONVECTION AND SFC HIGH PRESSURE DRIES OUT THE AIR MASS A BIT. EAST
KENTUCKY WILL REMAIN BETWEEN WEATHER SYSTEMS THROUGH WEDNESDAY AS A
BAND OF CONVECTION ASSOCIATED WITH THE STACKED LOW AND ITS OCCLUDED
FRONT SLOWLY MOVE DEEPER INTO KENTUCKY. THE WARM WEATHER THAT
PRECEDED THE FRONT WILL HAVE ITS LAST HURRAH ON WEDNESDAY BEFORE THE
MATURE LOW...ITS OCCLUDED COLD SECTOR...AND RENEWED RAINS WILL
COMBINE TO RETURN US TO TEMPERATURES CLOSER TO NORMAL FOR THIS TIME
OF YEAR AT THE END OF THE WORK WEEK AND TO START THE WEEKEND. THE
BEST CONVECTIVE THREAT LOOKS TO BE THURSDAY AND INTO FRIDAY MORNING
AS THAT BOUNDARY MOVES INTO THE AREA. THIS WILL ALSO BE THE PEAK TIME
FOR EXCESSIVE RAINFALL...AS WELL. ONCE THE FRONT PASSES THROUGH THE
AREA...JUST THE SHOWERS AND STRAY THUNDERSTORMS TYPICALLY FOUND
SCATTERED AROUND THE CENTER OF A MATURE LOW CAN BE EXPECTED THROUGH
THE DAY FRIDAY AND INTO SATURDAY.
THE GRID LOAD CAME IN REASONABLE ENOUGH CONSIDERING THE SLUGGISH
MOVEMENT OF THE SFC FEATURES TO AFFECT THE AREA THROUGH THE PERIOD.
DID FINE TUNE THE POPS FOR A SLOWER ARRIVAL ON THURSDAY...
ESPECIALLY IN THE EAST. PUT A DIURNAL COMPONENT INTO THE POP GRIDS
THROUGH THE LATTER PART OF THE EXTENDED. ALSO...RAISED MAX TEMPS A
BIT FOR MONDAY THROUGH WEDNESDAY AND ADDED MINOR TERRAIN BASED
ADJUSTMENTS BENEATH THAT BUILDING RIDGE EACH NIGHT FROM MONDAY NIGHT
THROUGH WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 130 PM EDT SAT MAR 17 2012
VRF CONDITIONS...WEAK LOW LEVEL FLOW...AND ONLY SOME CEILINGS AROUND
5 KFT AND 10 KFT WILL PERSIST THROUGH THE DAY. A STRAY SHOWER IS
POSSIBLE BUT OVERALL...THIS SHOULD BE A QUIET DAY AVIATION WISE. SOME
MVFR CONDITIONS WILL DEVELOP AFTER 02Z AS A STRONGER WAVE MOVES
THROUGH THE AREA TONIGHT. SOME SCATTERED SHOWERS AND THUNDERSTORMS
MAY DEVELOP AND SHOULD PERSIST THROUGH 06Z. VFR CONDITIONS WILL
RETURN BY 15Z TOMORROW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MB
SHORT TERM...SHALLENBERGER
LONG TERM....GREIF
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
351 PM EDT SAT MAR 17 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 351 PM EDT SAT MAR 17 2012
CURRENT CONDITIONS ACROSS THE AREA AS OF 19Z HAS A ROBUST CU FIELD
DEVELOPING OVER CENTRAL KENTUCKY EXTENDING INTO THE BLUE GRASS
COUNTIES AND ALONG THE I-75 CORRIDOR. SO FAR TODAY...ONLY A FEW
SHOWERS HAVE DEVELOPED AND JUDGING BY WHATS GOING ON UPSTREAM...THE
WEAK WAVE PICKED OUT IN THE RUC AND SREF...HAS ONLY BEEN ABLE TO GEN
UP A FEW SHOWERS. IT SEEMS WE WILL HAVE TO WAIT TILL TONIGHT FOR THE
STRONGER WAVE OUT IN WESTERN KENTUCKY TO MOVE INTO THE OUR CWFA TO
PRODUCE ANY SHOWERS AND THUNDERSTORMS. BY THIS POINT...THE
INSTABILITY TO WORK WITH FROM THE DAY WILL HAVE BEEN PRETTY MUCH CUT
OFF SO EXPECTING JUST SOME RUN OF THE MILL SHOWERS AND THUNDERSTORMS
THIS EVENING AND TONIGHT.
WITH AMPLE MOISTURE FROM THE GULF CONTINUING...THE WAVE MOVING
THROUGH TONIGHT WILL PRODUCE THE CHANCE FOR SHOWERS AND
THUNDERSTORMS THROUGH SUNDAY NIGHT. WATER VAPOR ALSO HINTED AT A
STRONG MOISTURE FLUX IN FROM THE BAJA REGION WITH A FEW EMBEDDED
WAVES AND THEREFORE A PROLONGED PERIOD OF PERIODIC SHOWER AND
THUNDERSTORM ACTIVITY THROUGH SUNDAY NIGHT SEEMS LIKELY. BY DAYTIME
HEATING FOR SUNDAY...SHOWER AND THUNDERSTORM ACTIVITY SHOULD
PERSIST. AT THIS POINT...DUE TO THE INCH AND A TENTH
PWATS...THINKING THAT RAINFALL DURING THIS PERIOD WILL BE THE ONLY
FACTOR TO MONITOR CLOSELY. THE CONTINUED CLOUD COVER OVER THE AREA
WILL KEEP THE THREAT OF STRONG STORMS IN CHECK BUT STORMS WITH HEAVY
RAINFALL WILL STILL BE POSSIBLE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 351 PM EDT SAT MAR 17 2012
THE MODELS BEGIN THE EXTENDED PORTION OF THE FORECAST IN DECENT
AGREEMENT ALOFT. THEY ALL HAVE THE FULL LATITUDE WESTERN TROUGH
DESCENDING AND DEEPENING INTO A CUT OFF LOW OVER NORTHERN TEXAS
DURING THE DAY TUESDAY. THIS RESULTS IN A STRONG DOWNSTREAM RIDGE
BUILDING OVER THE APPALACHIANS FROM MONDAY INTO TUESDAY NIGHT.
AROUND THIS TIME...THOUGH...THE MODELS START TO DIVERGE FROM EACH
OTHER WITH RESPECT TO THE THIS KEY FEATURE. THE ECMWF AND GEM MOVE
THE LOW EASTWARD QUICKER THAN THE GFS AND THIS DIFFERENCE CONTINUES
INTO THE DAY THURSDAY AS IT PIVOTS OVER THE MID MISSISSIPPI
VALLEY AND STARTS TO ENCROACH ON THE OHIO AND TENNESSEE VALLEYS. BY
THIS TIME THE WEAKER ECMWF IS ABOUT 200 MILES EAST OF THE GFS AND
THE GEM ABOUT THE SAME DISTANCE TO THE SOUTHEAST. GIVEN THE MID
LEVEL JET RUNNING SOUTHWEST TO NORTHEAST THROUGH THE MIDDLE OF THE
CONTINENT...PREFER THE SLOWER GFS IN THIS CUTOFF FAVORING FLOW
PATTERN. AS THE UPPER LOW SLOWLY CROSSES THE MISSISSIPPI RIVER AND
MOVES OVER WESTERN TENNESSEE AND KENTUCKY...THE ECMWF WILL START TO
RETROGRADE. AS A RESULT...BY FRIDAY EVENING THEY HAVE A SIMILAR
MAGNITUDE AND PLACEMENT FOR THE LOW...PRETTY MUCH CENTERED OVER EAST
KENTUCKY. FURTHER NORTH...THOUGH...THEY DIFFER ON THE MAGNITUDE OF A
TROUGH IN THE JET STREAM SO THAT EVEN THE SIMILARITIES OVER OUR AREA
TO END THE WEEK DOES NOT ENHANCE CONFIDENCE. THE MODELS THEN TAKE
THE REMAINS OF THEIR LOWS SLOWLY EAST THROUGH THE APPALACHIANS AND
TO THE EAST COAST...AS RIDGING BUILDS INTO THE PLAINS. DUE TO LOW
CONFIDENCE WITH HOW THE UPPER LOW IS FINALLY KICKED OUT OF THE
REGION WILL DOWN PLAY THIS POTENTIAL FOR NOW.
SENSIBLE WEATHER WILL FEATURE A CONTINUATION OF OUR RECENT HEAT
WAVE. THERE WILL BE A LULL IN THE SHOWERS AND STORMS OF THE PAST FEW
DAYS ON MONDAY AS THE UPPER RIDGE BUILDS ENOUGH TO CAP SUPPRESS ANY
CONVECTION AND SFC HIGH PRESSURE DRIES OUT THE AIR MASS A BIT. EAST
KENTUCKY WILL REMAIN BETWEEN WEATHER SYSTEMS THROUGH WEDNESDAY AS A
BAND OF CONVECTION ASSOCIATED WITH THE STACKED LOW AND ITS OCCLUDED
FRONT SLOWLY MOVE DEEPER INTO KENTUCKY. THE WARM WEATHER THAT
PRECEDED THE FRONT WILL HAVE ITS LAST HURRAH ON WEDNESDAY BEFORE THE
MATURE LOW...ITS OCCLUDED COLD SECTOR...AND RENEWED RAINS WILL
COMBINE TO RETURN US TO TEMPERATURES CLOSER TO NORMAL FOR THIS TIME
OF YEAR AT THE END OF THE WORK WEEK AND TO START THE WEEKEND. THE
BEST CONVECTIVE THREAT LOOKS TO BE THURSDAY AND INTO FRIDAY MORNING
AS THAT BOUNDARY MOVES INTO THE AREA. THIS WILL ALSO BE THE PEAK TIME
FOR EXCESSIVE RAINFALL...AS WELL. ONCE THE FRONT PASSES THROUGH THE
AREA...JUST THE SHOWERS AND STRAY THUNDERSTORMS TYPICALLY FOUND
SCATTERED AROUND THE CENTER OF A MATURE LOW CAN BE EXPECTED THROUGH
THE DAY FRIDAY AND INTO SATURDAY.
THE GRID LOAD CAME IN REASONABLE ENOUGH CONSIDERING THE SLUGGISH
MOVEMENT OF THE SFC FEATURES TO AFFECT THE AREA THROUGH THE PERIOD.
DID FINE TUNE THE POPS FOR A SLOWER ARRIVAL ON THURSDAY...
ESPECIALLY IN THE EAST. PUT A DIURNAL COMPONENT INTO THE POP GRIDS
THROUGH THE LATTER PART OF THE EXTENDED. ALSO...RAISED MAX TEMPS A
BIT FOR MONDAY THROUGH WEDNESDAY AND ADDED MINOR TERRAIN BASED
ADJUSTMENTS BENEATH THAT BUILDING RIDGE EACH NIGHT FROM MONDAY NIGHT
THROUGH WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 130 PM EDT SAT MAR 17 2012
VRF CONDITIONS...WEAK LOW LEVEL FLOW...AND ONLY SOME CEILINGS AROUND
5 KFT AND 10 KFT WILL PERSIST THROUGH THE DAY. A STRAY SHOWER IS
POSSIBLE BUT OVERALL...THIS SHOULD BE A QUIET DAY AVIATION WISE. SOME
MVFR CONDITIONS WILL DEVELOP AFTER 02Z AS A STRONGER WAVE MOVES
THROUGH THE AREA TONIGHT. SOME SCATTERED SHOWERS AND THUNDERSTORMS
MAY DEVELOP AND SHOULD PERSIST THROUGH 06Z. VFR CONDITIONS WILL
RETURN BY 15Z TOMORROW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SHALLENBERGER
LONG TERM....GREIF
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
430 PM EDT SAT MAR 17 2012
.SYNOPSIS...
ISSUED AT 428 PM EDT SAT MAR 17 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH NEAR
THE WEST COAST AND A BROAD DOWNSTREAM RIDGE OVER THE CNTRL AND ERN
CONUS RESULTING IN SW FLOW INTO THE UPPER GREAT LAKES. AT THE
SFC...SRLY FLOW AHEAD OF A TROUGH OVER THE PLAINS HAS BROUGHT GULF
MOISTURE AND RECORD BREAKING WARM AIR FROM THE PLAINS AND MS VALLEY
INTO THE WRN GREAT LAKES AND NRN ONTARIO. DESPITE CAPE VALUES INTO
TO AROUND 2K J/KG...ENOUGH CAPPING PREVAILED OVER THE CWA...PER 12Z
KMPX SOUNDING TO PREVENT TSRA DEVELOPMENT OVER THE CWA.
HOWEVER...CONVECTION HAD DEVELOPED ABOVE THE MARINE LAYER NEAR THE
STRAITS...WHERE THE CAP WAS WEAKER.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 428 PM EDT SAT MAR 17 2012
TONIGHT INTO SUNDAY...UNSEASONABLY WARM AND MOIST CONDITIONS WILL
CONTINUE ACROSS THE AREA AS LOW LEVEL MOISTURE REMAINS IN PLACE
ALONG WITH RELATIVELY STEEP MID LEVEL LAPSE RATES FROM 7.5C-8.5C/KM.
THIS INSTABILITY WOULD BE ENOUGH TO WARRANT KEEPING SLIGHT CHC POPS
FOR TSRA POTENTIAL OVER THE AREA. HOWEVER...ANY SHORTWAVES LIFTING
INTO THE NRN GREAT LAKES ARE EXPECTED TO BE WEAK AND THE GREATEST
ISENTROPIC LIFT NEAR THE NOSE OF THE LOW LEVEL JET 850 MB WARM FRONT
AND WEAKER CAPPING SHOULD REMAIN NORTH AND EAST OF THE CWA...PER
MODEL DATA. WITH HIGHER DEWPOINTS...EXPECT MORE FOG/STRATUS
DEVELOPMENT...ESPECIALLY OFF OF LAKE MICHIGAN AND AREAS WITH UPSLOPE
SRLY FLOW. RECORD HIGH MINIMUM VALUES ARE EXPECTED WITH LOWS ONLY
DROPPING INTO THE LOWER 50S AT MOST LOCATIONS.
STRONG SRLY FLOW AND WAA WILL PUSH 850 MB TEMPS INTO THE 12C TO 14C
RANGE. SO...WITH SUNSHINE AND DECENT MIXING...EXPECT HIGH TEMPS
AGAIN WELL INTO 70S ACROSS THE W HALF OF UPPER MI AND PERHAPS EVEN
LOWER 80S AT SOME SPOTS. TEMPS WILL REMAIN SUBSTANTIALLY LOWER
DOWNWIND OF LAKE MICHIGAN WHERE READINGS WILL BE IN THE LOWER 50S
ALONG THE SHORE TO LOWER 60S WELL INLAND.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 428 PM EDT SAT MAR 17 2012
WHAT GOES UP /OUR STRETCH OF UNSEASONABLE WARM TEMPERATURES/ MUST
GO DOWN...EVENTUALLY...BUT THE MAIN QUESTION IS THE DEGREE IT WILL
GO DOWN. DEEP TROUGH OVER FAR WESTERN CONUS IS FCST TO COME EAST
THROUGHOUT THE WEEK. GOOD AGREEMENT IN OVERALL SCENARIO THROUGH
ROUGHLY MID WEEK...THEN MODEL DIFFERENCES START CREEPING INTO THE
PICTURE BY LATE WEEK/NEXT WEEKEND. MAIN ISSUE AT THAT TIME IS HOW
MUCH TROUGHING/COLD AIR WILL BE OVER THE UPR LAKES FRIDAY INTO
SATURDAY. MODELS EARLIER THIS WEEK SHOWED MAIN TROUGH SPLITTING INTO
TWO...WITH MORE OF A CUTOFF LOW OVER SOUTHERN PLAINS MEANDERING
ACROSS CNTRL CONUS...BUT MAINLY REMAINING SOUTH OF UPR LAKES. MORE
RECENT MODEL RUNS SHOWED MORE PHASING BTWN THE TWO TROUGHS OVR THE
UPR LAKES BY LATE WEEK. LATELY THE MODELS AND ENSEMBLES ARE
INDICATING MORE SPLIT PATTERN AGAIN. ECMWF IS THE ONLY MODEL SHOWING
MORE OF A PHASED LOOK WHILE ECMWF ENSEMBLES DEVELOP TROUGH FARTHER
EAST...ALLOWING HEIGHTS TO REBOUND OVR UPR LAKES AS QUICKLY AS NEXT
SATURDAY.
INITIALLY TO START THE LONGER RANGE WARM AND MOIST SOUTHERLY FLOW
REGIME WILL BE IN FULL SWING SOUTH OF WARM FRONT. NOT A WHOLE LOT OF
LARGER SCALE FEATURES TO PIN POPS TO SUNDAY NIGHT AND MONDAY. LOOKS
LIKE THERE ARE A FEW AREAS OF ISENTROPIC ASCENT FLOWING INTO THE UPR
LAKES THAT MAY TRIGGER CONVECTION IN THE MOIST ENVIRONMENT. BETTER
CHANCE WOULD BE OVER WEST AND NORTHWEST CWA. NOTHING MORE THAN
SLIGHT CHANCES THOUGH GIVEN LACK OF SUPPORT FM SHORTWAVES AND UPR
JET SUPPORT. THUNDER CHANCES SEEM PRETTY REMOTE AS H7-H5 LAPSE
RATES ARE DECREASING WITH ARRIVAL OF WARM AIR ALOFT. SI/S START OUT
SUNDAY NIGHT INTO MONDAY A BIT BLO 0C BUT BY LATER MONDAY INTO
MONDAY NIGHT STABILITY ONLY INCREASES.
WELL ABOVE NORMAL TEMPERATURES SHOULD CONTINUE THROUGH MIDWEEK
WITH MORE RECORD HIGHS EXPECTED. COOLING TREND IS EXPECTED BY
LATE WEEK INTO NEXT WEEKEND AS PLAINS TROUGH SLIDES INTO CNTRL
CONUS. GREATEST CHANCE OF RAIN FOR THE WEEK OCCURS WEDNESDAY AS
FRONTAL BOUNDARY AHEAD OF TROUGH/POOLING MOISTURE ALONG THE FRONT
AND RIGHT ENTRANCE FORCING FM UPR JET CONGEAL OVR UPR LAKES. DESPITE
ABUNDANCE OF MOISTURE STREAMING NORTH /PWATS OVR 300 PCT OF NORMAL/
NOT SURE THAT WILL EQUATE TO WIDESPREAD SOAKING RAIN OVR THE CWA.
WHERE IT DOES RAIN...IT COULD BE HEAVY AT TIMES THOUGH. FOR NOW HAVE
HIGHEST POPS ON WEDNESDAY OVER THE NORTHERN CWA CLOSER TO INFLUENCE
OF UPR JET OVR ONTARIO. EVENTUALLY THOUGH POPS MAY NEED TO BE PUSHED
INTO THE LIKELY CATEGORY OVR MUCH OF CWA.
EXTENT OF TROUGHING/COOLING STILL IN QUESTION FOR LATE WEEK AND NEXT
WEEKEND. ECMWF CONTINUES ITS TREND OF SHARPER TROUGHING AND COOLER
TEMPS /H85 TEMPS BLO -5C/ WHICH WOULD RESULT IN MORE CLOUDS THAN
CURRENT FCST SHOWS AND TEMPS COOLING INTO THE 30S. CHANCES OF PCPN
APPEAR LOW THOUGH AS ALTHOUGH IT WOULD BE COOL IT LOOKS FAIRLY DRY
AS WELL. GIVEN LACK OF CONSISTENCY IN MODEL SOLUTIONS HAVE NOT
STRAYED TOO FAR FM CONSENSUS AT THIS POINT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 133 PM EDT SAT MAR 17 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT ALL SITES EXCEPT
TONIGHT INTO SUN MORNING AT SAW. LLWS WILL ALSO BE PRESENT AT ALL
SITES EARLY THIS MORNING AND THEN AGAIN TONIGHT. CONFIDENCE IS
FAIRLY HIGH THAT ABUNDANT OF LOW-LEVEL MOISTURE WILL LEAD TO MORE
STRATUS AND FOG AT KSAW TONIGHT WITH UPSLOPE SSE FLOW. AIRFIELD
LANDING MINIMUMS COULD BE APPROACHED AT KSAW BY LATE EVENING OR
OVERNIGHT. THERE IS ALSO A SLIM RISK OF ISOLD SHRA/TSRA AT ALL THREE
SITES INTO TONIGHT. HOWEVER...CHANCE IS JUST TOO LOW AT THIS
POINT TO EVEN MENTION A CB IN THE CLOUD GROUP. FOG/STRATUS AT KSAW
SHOULD LIFT BY AROUND 15Z SUNDAY MORNING WITH DIURNAL MIXING...SIMILAR
TO TODAY. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 428 PM EDT SAT MAR 17 2012
EXPECT GENERALLY S-SE WINDS LESS THAN 25 KTS INTO NEXT WEEK AS HIGH
PRESSURE DOMINATES OVER THE UPR GREAT LAKES REGION. UNSEASONABLY
WARM AIR OVER THE UPPER GREAT LAKES WILL ALSO RESULT IN PERSISTENT
MARINE LAYER/STRONG STABILITY OVER THE LAKE. WITH THE UNSEASONABLY
HIGH DEWPOINTS MOVING INTO THE AREA...AREAS OF FOG WILL ALSO
CONTINUE OVER THE AREA WITH LCLY DENSE FOG POSSIBLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
335 PM CDT SAT MAR 17 2012
.DISCUSSION...
LARGE CU AND LEFT OVER STRATUS FILED STILL WITH US LATE THIS
AFTERNOON BUT THINNING OUT IN THE WEST..ESPECIALLY LEE OF THE
BUFFALO RIDGE INTO THE UPPER MN RIVER VALLEY. WE ARE GENERALLY IN
A BROAD WARM SECTOR WITH PLENTY OF ML CAPE BUT THE GREATER 0-3KM
CAPE IS WELL OFF TO THE EAST ON WI. ANY DEFINED SURFACE BOUNDARIES
ARE IN FAR NORTHERN MINNESOTA AND IN THE CENTRAL DAKOTAS NEAR THE
PSEUDO DRY LINE. LATEST AIRCRAFT SOUNDING OUT OF KMSP STILL
SHOWING A DECENT INVERSION. LOOKS LIKE A SIMILAR SITUATION TONIGHT FOR
REDEVELOPMENT OF THE LOW CLOUDS OVERNIGHT. LATEST RUC PROFILES AND
THE 12Z NAM SHOWING THIS TREND AND SEEMS REASONABLE BASED ON CU
FIELD ITO THE SOUTHERN PLAINS. WE MAY SEE A PERIOD OF SKC HERE AND
THERE BEFORE REDEVELOPMENT LATE TONIGHT OR EARLY SUNDAY MORNING.
NO TRIGGERS OR SIGNIFICANT ADVECTIVE FIELDS UNTIL SUNDAY NIGHT
WHEN BOTH THE EC AND NAM SHOW A WEAK WAVE MOVING NORTHEAST THROUGH
THE PLAINS. LOTS OF ML CIN OVER THE AREA ON SUNDAY AS WELL. IT
LOOKS WEAK AT THIS POINT SO WILL CONTINUE THE SLIGHT CHANCE OVER
SOUTH CENTRAL AND SOUTHWEST MINNESOTA LATER SUNDAY NIGHT.
THE MAIN PUSH OF FORCING AND HIGH PRECIPITABLE WATER OUT OF THE
LONG WEAVE TROUGH WILL BE MONDAY INTO TUESDAY. BOTH THE NAM AND
GFS ARE FORECASTING PWAT VALUES CLOSE TO 1.2 INCHES WHICH WOULD BE
AT "RECORD LEVELS" BASED ON THE CLIMATOLOGY STUDY OF CONUS RAOB
SITES. QUITE A MERIDIONAL UPPER FLOW AS THIS WAVE MOVES OUT...WITH
DECREASED SHEAR. SEVERE CHANCES STILL IN QUESTION BUT CANT RULE
OUT A FEW STRONG STORMS BEFORE THE MORE SATURATED CONDITIONS
DEVELOP. WILL UP POPS IN A FEW AREAS..ESPECIALLY WEST INITIALLY
WITH HIGHER POPS CONTINUING EAST INTO TUESDAY.
CUTTING OFF OF AN UPPER LOW OVER THE SOUTHERN PLAINS LOOKS
REASONABLE MID WEEK WHICH COULD CUT OF THE LINGERING LOWER POPS
THAT WE HAVE LATER IN THE WEEK. THE EC LOOKS TO BE MORE CUT OFF
THAN THE GFS.
&&
.AVIATION.../18Z TAF ISSUANCE/
ALL IT TOOK WITH ALL THE JUICE IN THE AIR THIS MORNING TO GET
IFR/MVFR STRATUS GOING WAS A LITTLE BIT OF LIFT ASSOCIATED WITH
GETTING MIXING GOING. SATELLITE SHOWS CLOUDS BEGINNING TO BECOME
CELLULAR IN NATURE WHILE OBS LIFTING AT THE SAME TIME. IFR
CONDITIONS ARE DONE...AND MVFR CIGS SHOULD ONLY LAST AN HOUR OR
TWO BEFORE SKIES SLOWLY WORK BACK TOWARD SKC AROUND SUNSET. LITTLE
CHANGE IN THE ATMOSPHERE IS EXPECTED OVERNIGHT...SO RELIED HEAVILY
ON PERSISTENCE WHEN IT CAME TO IFR/MVFR CIGS IN TAFS SUNDAY
MORNING. LIKE TODAY...WILL BE PLENTY OF MOISTURE IN THE LOWER
LEVELS FOR FG/STRATUS...BUT WINDS WILL KEEP THINGS MIXED...WITH
VIS ONLY DROPPING OFF INTO THE MVFR...POSSIBLE IFR RANGE. CLOUDS
NOT EXPECTED TO FORM UNTIL A SOURCE OF LIFT SHOWS UP...WHICH
WOULD BE SOLAR HEATING. ONCE AGAIN...ANTICIPATE CLOUDS TO FORM
WITHIN AN HOUR OR TWO AFTER SUNRISE...WITH SKIES REMAINING MOSTLY
CLOUDY THROUGH THE MORNING. ONE WORRY FOR THIS SCENARIO IS THAT
LOW PRESSURE THAT WAS OVER THE CENTRAL/ERN DAKOTAS THIS MORNING
WILL BE OVER ERN MT SUNDAY MORNING. AREAS OF WI FURTHER FROM THE
DAKOTAS LOW THIS MORNING SAW NO LOW CLOUDS DEVELOP. IN
ADDITION...TRAJECTORY PLOTS SHOW LOW LEVEL AIR SUNDAY MORNING
ORIGINATING FROM SRN MO THIS MORNING...WHERE THERE WAS NOT
STRATUS. BASED ON THIS...WOULD NOT BE SURPRISED IF WE WOUND UP
STRATUS FREE...THOUGH NAM/GFS BUFKIT SOUNDINGS WOULD CERTAINLY
LEAN TOWARD THE STRATUS SCENARIO. WIND DIRECTION NOT EXPECTED TO
CHANGE MUCH AT ALL...WITH SPEEDS FOLLOWING A TYPICAL DIURNAL
TREND...WITH SPEEDS TONIGHT SIMILAR TO LAST NIGHT AND SPEEDS
SUNDAY SIMILAR TO/SLIGHTLY STRONGER THAN TODAY.
KMSP...EXPECT MVFR CIGS TO LIFT INTO A VFR BKN CIG WITHIN THE
HOUR. AS BREAKS IN OVC GROW...INCREASED MIXING WILL FURTHER LIFT
THE CIGS TO AROUND 4K FT...WITH SKY COVER SLOWLY DIMINISHING
THROUGH THE AFTERNOON. PLAYED A SIMILAR TREND IN CIGS SUNDAY
MORNING TO WHAT WAS SEEN THIS MORNING. NOT COMPLETELY CONFIDENT IN
THIS PLAYING OUT...AS THE SHIFT IN THE SFC LOW BACK TO THE WEST
MAY END UP SHIFTING STRATUS FORMATION THAT WAS SEEN OVER MN TODAY
INTO THE DAKOTAS TOMORROW.
//OUTLOOK...MON THROUGH THURSDAY...
.MON-TUE...IFR/MVFR CIGS POSSIBLE. SHRA/TSRA LIKELY WITH SLOW FROPA.
.WED-THU...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
118 PM CDT SAT MAR 17 2012
.UPDATE...
18Z AVIATION DISCUSSION ADDED.
&&
.PREV DISCUSSION...
/ISSUED 732 AM CDT SAT MAR 17 2012/
LATEST WV IMAGERY OVERLAID WITH RUC 400-500MB LAYER WINDS SHOWS
SUBTLE SHORTWAVE RESPONSIBLE FOR THE EVENING CONVECTION ACROSS
NORTHERN WISCONSIN HAS MOVED NORTHEAST. MEANWHILE...ANOTHER WEAK
WAVE IS FORCING A FEW SHOWERS ACROSS SOUTHWEST WISCONSIN...BUT
THIS WILL REMAIN SOUTH AND EAST OF THE FORECAST AREA. FURTHER
UPSTREAM ANOTHER SHORT WAVE LOCATED OVER KANSAS WILL MOVE
NORTHEAST TODAY...BUT IT TOO SHOULD TRACK SOUTH AND EAST OF THE
CWA. GIVEN THE SUMMER LIKE AIRMASS IN PLACE...AS INDICATED BY
THE TROPOPAUSE HEIGHT OF 225 MB VIA THE 00Z MPX RAOB...A SMALL
AMOUNT FORCING IS SUFFICIENT TO PRODUCE CONVECTION. HOWEVER...HAVE
KEPT THE FORECAST DRY FOR TODAY AND SUNDAY SINCE CONFIDENCE IS LOW
THAT SHOWERS AND THUNDERSTORMS WILL DEVELOP DESPITE THE HIGH CAPE
VALUES. THINKING IS THAT A WIDESPREAD CUMULUS FIELD WILL ENSUE
RATHER THAN ANY DEEP CONVECTION.
BY SUNDAY NIGHT A LONG WAVE TROUGH THAT IS CURRENTLY DIGGING OFF
THE COAST OF CALIFORNIA WILL BEGIN TO AFFECT THE UPPER MIDWEST.
MODELS SHOW A WEAK SHORTWAVE MOVING UP FROM THE SOUTHWEST IN
CONJUNCTION WITH A STRENGTHENING LOW LEVEL JET. THIS SHOULD
TRIGGER SOME SHOWER AND THUNDERSTORM DEVELOPMENT SUNDAY NIGHT INTO
MONDAY. THE BEST DYNAMICS REMAIN TO THE WEST IN THE VICINITY OF A
+120KT GET...SO DEEP LAYER SHEAR VALUES IN THE 20-25KT RANGE
INDICATE A MINIMAL THREAT FOR SEVERE WEATHER. THIS IS ALSO
SUPPORTED BY THE NARROW CAPE PROFILES IN THE FORECAST SOUNDINGS.
LOOKS LIKE SOME MUCH NEEDED RAIN SHOWERS WILL BE THE MAIN
RESULT...WITH A FEW SUB SEVERE THUNDERSTORMS MIXED IN AS WELL.
MODELS THEN TRANSITION THIS TROUGH TO A CUTOFF LOW ON WEDNESDAY
AND VARY IN LOCATION. THE GEM 17.00 IS FURTHEST SOUTH OVER
ARKANSAS...WHILE THE ECMWF TAKES IT ACROSS THE OHIO RIVER
VALLEY...AND THE GFS 17.00 IS SLOW TO MOVE THIS SYSTEM OUT FROM
THE CENTRAL CONUS. GIVEN THE MODEL UNCERTAINTY...DID NOT DEVIATE
MUCH FROM GUIDANCE IN THE EXTENDED.
&&
.AVIATION.../18Z TAF ISSUANCE/
ALL IT TOOK WITH ALL THE JUICE IN THE AIR THIS MORNING TO GET
IFR/MVFR STRATUS GOING WAS A LITTLE BIT OF LIFT ASSOCIATED WITH
GETTING MIXING GOING. SATELLITE SHOWS CLOUDS BEGINNING TO BECOME
CELLULAR IN NATURE WHILE OBS LIFTING AT THE SAME TIME. IFR
CONDITIONS ARE DONE...AND MVFR CIGS SHOULD ONLY LAST AN HOUR OR
TWO BEFORE SKIES SLOWLY WORK BACK TOWARD SKC AROUND SUNSET. LITTLE
CHANGE IN THE ATMOSPHERE IS EXPECTED OVERNIGHT...SO RELIED HEAVILY
ON PERSISTENCE WHEN IT CAME TO IFR/MVFR CIGS IN TAFS SUNDAY
MORNING. LIKE TODAY...WILL BE PLENTY OF MOISTURE IN THE LOWER
LEVELS FOR FG/STRATUS...BUT WINDS WILL KEEP THINGS MIXED...WITH
VIS ONLY DROPPING OFF INTO THE MVFR...POSSIBLE IFR RANGE. CLOUDS
NOT EXPECTED TO FORM UNTIL A SOURCE OF LIFT SHOWS UP...WHICH
WOULD BE SOLAR HEATING. ONCE AGAIN...ANTICIPATE CLOUDS TO FORM
WITHIN AN HOUR OR TWO AFTER SUNRISE...WITH SKIES REMAINING MOSTLY
CLOUDY THROUGH THE MORNING. ONE WORRY FOR THIS SCENARIO IS THAT
LOW PRESSURE THAT WAS OVER THE CENTRAL/ERN DAKOTAS THIS MORNING
WILL BE OVER ERN MT SUNDAY MORNING. AREAS OF WI FURTHER FROM THE
DAKOTAS LOW THIS MORNING SAW NO LOW CLOUDS DEVELOP. IN
ADDITION...TRAJECTORY PLOTS SHOW LOW LEVEL AIR SUNDAY MORNING
ORIGINATING FROM SRN MO THIS MORNING...WHERE THERE WAS NOT
STRATUS. BASED ON THIS...WOULD NOT BE SURPRISED IF WE WOUND UP
STRATUS FREE...THOUGH NAM/GFS BUFKIT SOUNDINGS WOULD CERTAINLY
LEAN TOWARD THE STRATUS SCENARIO. WIND DIRECTION NOT EXPECTED TO
CHANGE MUCH AT ALL...WITH SPEEDS FOLLOWING A TYPICAL DIURNAL
TREND...WITH SPEEDS TONIGHT SIMILAR TO LAST NIGHT AND SPEEDS
SUNDAY SIMILAR TO/SLIGHTLY STRONGER THAN TODAY.
KMSP...EXPECT MVFR CIGS TO LIFT INTO A VFR BKN CIG WITHIN THE
HOUR. AS BREAKS IN OVC GROW...INCREASED MIXING WILL FURTHER LIFT
THE CIGS TO AROUND 4K FT...WITH SKY COVER SLOWLY DIMINISHING
THROUGH THE AFTERNOON. PLAYED A SIMILAR TREND IN CIGS SUNDAY
MORNING TO WHAT WAS SEEN THIS MORNING. NOT COMPLETELY CONFIDENT IN
THIS PLAYING OUT...AS THE SHIFT IN THE SFC LOW BACK TO THE WEST
MAY END UP SHIFTING STRATUS FORMATION THAT WAS SEEN OVER MN TODAY
INTO THE DAKOTAS TOMORROW.
//OUTLOOK...MON THROUGH THURSDAY...
.MON-TUE...IFR/MVFR CIGS POSSIBLE. SHRA/TSRA LIKELY WITH SLOW FROPA.
.WED-THU...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JRB/MPG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
454 PM EDT SAT MAR 17 2012
.SYNOPSIS...
A WEAK SURFACE TROUGH MEANDERING ACROSS THE REGION WILL BRING
ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THE WEEKEND AND INTO
MONDAY. OTHERWISE...ABOVE NORMAL TEMPERATURES WILL PREVAIL THROUGH
MUCH OF NEXT WEEK...AS AN UPPER RIDGE OVER THE REGION AMPLIFIES.
&&
.UPDATE /TONIGHT/...
AS OF 450 PM SATURDAY...AFTER SPEAKING WITH A REPRESENTATIVE OF NC
FORESTY WE HAVE ISSUED A DENSE SMOKE ADVISORY FOR INLAND PORTION OF
BRUNSWICK COUNTY FROM 8 PM THIS EVENING UNTIL 10 PM SUNDAY. A GROUND
FIRE IN THE GREEN SWAMP IS STILL PRODUCING COPIOUS AMOUNTS OF
SMOKE...WHICH SHOULD BECOME TRAPPED BY A STRONG TEMPERATURE
INVERSION TONIGHT. WE ARE EXPECTING VERY LOW VISIBILITIES TO DEVELOP
ALONG PORTIONS OF HIGHWAY 211 (GREEN SWAMP ROAD) IN NORTHWESTERN
BRUNSWICK COUNTY...WHERE SEVERAL VEHICLE ACCIDENTS WERE REPORTED
LAST NIGHT. NO OTHER CHANGES AT THIS TIME. -TRA
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SATURDAY...EAST-WEST BOUNDARY SEPARATING NRLY AND SRLY
WINDS VERY ROUGHLY BISECTING THE REGION RIGHT NOW/CLOSE TO THE STATE
LINE. RUC ANALYSIS SUGGESTS THIS BOUNDARIES VERTICAL IDENTITY
EXTENDS TO ABOUT 925MB OR 3KFT. HIGHER DEWPOINTS AND LOWER LCLS
CONTINUE TO BE FOUND TO THE NORTH OF THIS BOUNDARY BUT ALAS CU
FIELDS CONTINUE TO BE MINIMAL. RADAR PRESENTATION OF SEA BREEZE ALSO
SUGGESTS A DEPTH OF ABOUT 3KFT. IN THE ABSENCE OF SYNOPTIC SCALE
LIFT NEITHER OF THESE ARE GOING TO BE TERRIBLY EFFECTIVE IN LEADING
TO CONVECTION WITH LFCS CURRENTLY CLOSER TO 6KFT. THIS SYNOPTIC
ASCENT THOUGH GENTLE WILL BE PROVIDED BY THE SHORTWAVE CURRENTLY
COMING OUT OF EASTERN TN. THERE IS STILL A SHORT WINDOW OF
OPPORTUNITY FOR CONVECTION TODAY FROM ABOUT 20 OR 21 UTC THROUGH
SUNDOWN AT WHICH TIME ANY COVERAGE OF STORMS WILL QUICKLY RUN OUT
OF DIURNALLY DRIVEN INSTABILITY. AS SEEN LAST NIGHT HOWEVER IT IS
DIFFICULT TO GO WITH A COMPLETELY DRY OVERNIGHT FORECAST IN LIGHT
OF A TRAILING 10 S-1 VORT OR TWO STILL PROGGED TO MOVE ACROSS.
THUS-20 POPS CARRIED OVERNIGHT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...A WEAK E-W SURFACE BOUNDARY WILL MEANDER
SOUTHWARD OVER OUR FORECAST ZONES ON SUNDAY. DESPITE REMAINING
BENEATH AN UPPER RIDGE...ENOUGH COLUMN MOISTURE AND INSTABILITY
WILL EXIST TO MAINTAIN ISOLATED SHOWERS AND THUNDERSTORMS SUNDAY
AND MONDAY. IT SHOULD BE NOTED THE ENVIRONMENTAL WIND FIELD WILL
REMAIN UNIMPRESSIVE AND ANY STORMS THAT FORM WILL FAVOR SURFACE
HEATING AND WILL LIKELY EXHIBIT PULSE CHARACTERISTICS.
BY MONDAY WE MAY SEE THE BOUNDARY LIFTING BACK NORTH. MOISTURE AND
INSTABILITY REMAIN SIMILAR AND HAVE EXTENDED ISOLATED POP VALUES
INTO MONDAY. GIVEN THE EXCESSIVE WARMTH...SEA-BREEZE CONVERGENCE
MAY ALSO PLAY A ROLE INITIATING CONVECTION SUNDAY AND MONDAY IN
THE AFTERNOON AND EARLY EVENINGS. MILD TEMPERATURES WILL PREVAIL
BOTH DAYS BENEATH THE THERMAL RIDGE...JUST A FEW DEGREES COOLER
ACROSS THE NORTHERN ZONES SUNDAY BEHIND THE FRONT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...DEEP 5H TROUGH OVER THE SOUTHWEST...A FAMILIAR
SIGHT THIS YEAR...AT THE START OF THE PERIOD PROVIDES PLENTY OF
UNCERTAINTY IN THE LONG RANGE PERIOD. MEDIUM RANGE GUIDANCE IN
DECENT AGREEMENT ON THE TROUGH TURNING INTO A 5H CUTOFF...BUT LITTLE
ELSE. TIMING REMAINS A BIG QUESTION AS SURFACE AND UPPER RIDGING
ALONG THE EAST COAST IS SURE TO HOLD STRONGER THAN GUIDANCE
INDICATES...MEANING THE MEDIUM RANGE SOLUTIONS ARE ALL LIKELY TOO
FAST MOVING THE 5H TROUGH/CUTOFF LOW EAST. HPC IS ALSO FAVORING A
SLOWER SOLUTION. THE END RESULT WILL BE A SUMMER-LIKE PATTERN WITH
STRENGTHENING 5H RIDGE AND BERMUDA HIGH. DIURNAL/SEA BREEZE
CONVECTION MAY DEVELOP TUE/WED BUT BUILDING 5H RIDGE AS THE UPPER
TROUGH/LOW MOVES EAST WILL HELP SUPPRESS UPWARD MOTION THU AND MAYBE
FRI DEPENDING ON HOW SLOW THE TROUGH/LOW MOVES EAST. COLD FRONT
MOVING INTO THE REGION LATE IN THE PERIOD WILL PROVIDE THE BEST
CHANCES FOR WIDESPREAD PRECIP. AREA OF DEEP MOISTURE AHEAD OF THE
FRONT IS LIMITED AND IT LOOKS LIKE THE BEST DYNAMICS PASS TO THE
NORTH. GIVEN THE UNCERTAINTY AND THE MARGINAL CONDITIONS DO NOT FEEL
ANYTHING MORE THAN A LOW CHANCE POP IS WARRANTED. TEMPERATURES WILL
RUN ABOVE TO WELL ABOVE CLIMO WITH HIGHS IN THE MID TO UPPER 70S AND
LOWS IN THE MID 50S.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 19Z...TERMINALS ARE VFR THIS AFTERNOON. SKIES ARE GENERALLY
SCATTERED...AND CUMULUS HAS JUST BEGUN TO DEVELOP.
A WEAK COLD FRONT WILL APPROACH FROM THE NORTH TODAY. A PIEDMONT
TROUGH WILL EXIST FROM KLBT TO KFLO AND A SEA BREEZE WILL DEVELOP
AND MOVE SLIGHTLY INLAND OF THE COASTAL TERMINALS LATER THIS
AFTERNOON. SUFFICIENT INSTABILITY WILL EXIST NEAR THESE FOCUS AREAS
FOR ISOLATED TO WIDELY SCATTERED SHOWERS TO OCCUR THROUGH MUCH OF
THIS TAF VALID PERIOD. ISOLATED THUNDERSTORMS WILL ALSO DEVELOP ONCE
THE CONVECTIVE TEMPERATURE IS REACHED OVER THE NEXT SEVERAL HOURS.
CONFIDENCE IS HIGHEST THAT THUNDERSTORMS WILL OCCUR NEAR THE KILM
AND KLBT TERMINALS LATER THIS AFTERNOON WITH TEMPO MVFR/IFR POSSIBLE.
OTHERWISE...MAINLY SHOWERS CAN BE EXPECTED. VFR CAN BE EXPECTED
OUTSIDE OF SHOWERS AND THUNDERSTORMS. DUE TO THE PROXIMITY OF THE
FRONT PRECIPITATION SHOULD LINGER THROUGH MUCH OF THE EVENING AND
OVERNIGHT HOURS.
WINDS WILL BE SOUTHWEST TODAY 5-10 KNOTS...BECOMING SOUTH AT THE
COASTAL TERMINALS IN THE NEXT SEVERAL HOURS DUE TO THE SEA
BREEZE. THIS EVENING AND OVERNIGHT WINDS WILL LIKELY BECOME LIGHT
SOUTHWEST AT THE SOUTHERN TERMINALS AND LIGHT AND VARIABLE AT KILM
AND KLBT. AT KILM AND KLBT THERE IS A GOOD CHANCE FOR IFR STRATUS TO
DEVELOP... WHILE MVFR VISIBILITIES WILL BE MOST LIKELY AT THE
REMAINING TERMINALS. EXPECT MVFR CONDITIONS OR GREATER 14-16Z WITH
SHOWERS DEVELOPING.
EXTENDED OUTLOOK...THROUGH THE PERIOD...MORNING FOG/MVFR...SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS IN THE AFTERNOON...THROUGH THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SATURDAY...WINDSHIFT BOUNDARY WILL BE LURKING NOT TOO FAR
TO THE NORTH OF THE AREA FOR MOST OF THE PERIOD. THIS BOUNDARY HAS
MADE MORE SOUTHERN PROGRESS OVER LAND THAN OVER WATER AND THIS WILL
LIKELY HOLD TRUE OVERNIGHT. THIS WILL PRECLUDE ANY NORTHERLY WIND
COMPONENT FROM ENTERING THE FORECAST AREA ALTHOUGH NORTHERN ZONES
MAY GO VERY LIGHT AND VARIABLE AS A RESULT OF HE PROXIMITY OF THE
TROUGH. LIGHT S TO SWRLY FLOW CAPPED AT 10 KTS WILL REMAIN IN PLACE
ELSEWHERE AS WEAK BERMUDA HIGH PRESSURE CONTINUES TO BE THE DOMINANT
WIND MAKER. SEAS REMAINING RELATIVELY DIMINUTIVE AT 2 TO 3 FT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...BY DAYBREAK SUNDAY NE WINDS WILL PREVAIL N
OF CAPE FEAR AS AN E-W FRONTAL BOUNDARY SLIPS SLOWLY SOUTHWARD.
WIND SPEEDS WILL HOLD BELOW 20-25 KNOTS SO ADVISORIES WILL NOT
BE NEEDED. THE FRONT MAY NOT MAKE IT TO WINYAH BAY LATE SUNDAY
AND COULD MOVE BACK NORTH SUNDAY NIGHT INTO MONDAY. THUS WE MAY
VERY WELL SEE A VARIABLE WIND DIRECTION SUNDAY AND MONDAY WITH
LIGHT SPEEDS OVERALL. NO PROBLEMS WITH SEAS...ESSENTIALLY 2-3 FT
IN A MIX OF SE WAVES AND SHORTER PERIOD SSW WIND CHOP. THE WEAK
FRONTAL BOUNDARY MAY TRIP OFF ISOLATED TSTMS NEAR OR OVER THE
WATERS. MARINERS SHOULD CONSULT RADAR TRENDS BEFORE HEADING OUT
SUNDAY AND MONDAY.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...MAJORITY OF THE PERIOD WILL BE MARKED BY SOUTH
TO SOUTHEAST WINDS AT OR BELOW 10 KT. BERMUDA HIGH WILL BE THE MAIN
FEATURE THOUGH LATE IN THE PERIOD A COLD FRONT WILL APPROACH FROM
THE WEST. TIMING OF THE COLD FRONT REMAINS A BIG QUESTION...BUT EVEN
THE FASTEST SOLUTION KEEPS THE FRONT TO THE WEST THROUGH THU
EVENING. THE FASTER SOLUTION DOES LEAD TO A PINCHED GRADIENT THU
WHICH WOULD PUSH SOUTHERLY FLOW CLOSE TO 20 KT. HOWEVER THE SLOWEST
AND THE FASTEST SOLUTION IS FAVORED. SO WHILE THERE MAY BE A
MARGINAL INCREASE IN SPEEDS THU AS GRADIENT TIGHTENS A LITTLE SPEEDS
SHOULD REMAIN UNDER 15 KT. SEAS WILL RUN 2 TO 3 FT TUE INTO WED BUT
A BUILDING EAST TO SOUTHEAST SWELL LATE IN THE PERIOD WILL PUSH SEAS
INTO THE 3 TO 5 FT RANGE THU.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...DENSE SMOKE ADVISORY FOR INLAND BRUNSWICK 8 PM SATURDAY UNTIL
10 AM SUNDAY.
MARINE...NONE.
&&
$$
NEAR TERM...MBB/TRA
SHORT TERM...MJC
LONG TERM...III
AVIATION...MRR/MBB
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 PM EDT SAT MAR 17 2012
.SYNOPSIS...
A WEAK BACK DOOR COLD FRONT WILL SETTLE SOUTH THROUGH CENTRAL NC
THROUGH TONIGHT. HIGH PRESSURE WILL FOLLOW AND RIDGE INTO NC FROM
THE COASTAL MIDDLE ATLANTIC REGION THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 315 PM SATURDAY...
THROUGH EARLY TONIGHT: A SURFACE TROUGH/WEAK BACK DOOR COLD FRONT
STRETCHED AT 18Z FROM NEAR KMRH-KSOP-KEXX...WHILE THE MORE
NOTICEABLE COOLING RELATIVE TO TEMPERATURES OF FRI HAVE BEEN FOCUSED
OVER NORTHEASTERN NC/SOUTHEASTERN VA OWING TO A MORE ONSHORE
COMPONENT OF THE LOW LEVEL FLOW OFF OF COOL MIDDLE ATLANTIC COASTAL
WATERS. THIS TRAILING MARITIME PUSH...ASSOCIATED ENHANCED CUMULUS
FIELD PER VISIBLE SATELLITE IMAGERY...AND LOCATION OF A H85 TROUGH
AXIS PER REGIONAL VWP DATA...WILL LIKELY MARK THE APPROXIMATE
NORTHEASTWARD BOUND FOR THE POTENTIAL FOR DEEP CONVECTIVE
DEVELOPMENT THIS AFTERNOON. ISOLATED TO SCATTERED CONVECTION WILL
REMAIN POSSIBLE THROUGHOUT CENTRAL NC THIS AFTERNOON...GIVEN THE
PRESENCE OF THESE TWO CONVERGENCE-FOCUSING BOUNDARIES AMIDST
DEVELOPING WEAK TO MODERATE BOUNDARY LAYER (BL)-BASED INSTABILITY
PER MODIFIED 12Z PROXIMITY RAOBS FOR REPRESENTATIVE BL PARCELS OF
UPPER 70S-LOWER 80S TEMPERATURES OVER 50 TO 60 DEGREE
DEWPOINTS...FROM NW TO SE.
ALOFT...A PAIR OF VORTICITY MAXIMA STRETCHED FROM THE SC UPSTATE TO
WEST-CENTRAL NC -- THE FORMER APPARENT ON SATELLITE IMAGERY AND MUCH
STRONGER PER RUC MID LEVEL VORTICITY ANALYSES -- WILL DRIFT EASTWARD
IN WEAK (10-15 KTS) WESTERLY MID LEVEL STEERING FLOW. THESE FEATURES
MAY FOCUS CONVECTION FROM CENTRAL SC TO SE NC THIS AFTERNOON.
STORMS HAVE ALSO ALREADY FIRED ON THE EAST-FACING SLOPES OF THE
NC/VA BLUE RIDGE...AND THE CONVECTIVE ALLOWING MODELS (CAMS)
CONTINUE TO INDICATE THE POTENTIAL FOR THESE TO PROPAGATE ON THEIR
CONGLOMERATE OUTFLOWS -- AND WITH THE AFOREMENTIONED WEAK MID LEVEL
STEERING FLOW -- EASTWARD INTO THE WESTERN PIEDMONT THROUGH EARLY
THIS EVENING. SOME OF THIS ACTIVITY MAY CONTINUE EASTWARD ACROSS THE
REMAINDER OF CENTRAL NC OVERNIGHT...THOUGH CONFIDENCE IS NOT HIGH
ENOUGH TO CARRY MORE THAN A SLIGHT TO LOW CHANCE POP INTO THE NIGHT
TIME HOURS.
MOIST MARITIME NORTHEASTERLY FLOW FROM OFF THE ATLANTIC...WHICH HAS
ALREADY SUPPORTED AN EXPANSIVE AREA OF MARINE STRATUS AND FOG ALL
THE WAY DOWN THE MID ATLANTIC COASTAL WATERS TO NEAR KORF AS OF
18Z...WILL PROMOTE THE DEVELOPMENT OF LOW STRATUS AND FOG FROM NE TO
SW ACROSS THE CWFA BETWEEN 04-10Z. GIVEN A LACK OF APPRECIABLE CAA
EXCEPT OVER THE FAR NORTHEAST...LOWS WILL BE SIMILAR TO PREVIOUS
NIGHTS - 52 TO 58... COOLEST NORTHEAST.
SUN AND SUN NIGHT: LOW STRATUS AND FOG WILL SLOWLY LIFT AND BURN OFF
DURING THE MORNING AND MIDDAY HOURS...BUT SCT TO BKN 2000-3500 FT
CLOUDS WILL LIKELY LINGER THROUGHOUT THE AFTERNOON. ANY PARTIAL
CLEARING LATE IN THE DAY AND DURING THE EVENING WILL THEN CAUSE
AREAS OF FOG AND/OR STRATUS TO REDEVELOP OVERNIGHT INTO EARLY MON.
THE CLOUDS AND MORE NOTICEABLY COOLER AIR MASS (ONCE THE
NORTHEASTERLY TO EASTERLY FLOW FULLY ENCOMPASSES CENTRAL NC
TONIGHT)...SHOULD HOLD TEMPS IN THE 71 TO 78 DEGREE RANGE FROM VA TO
SC STATE BORDERS. THE COOLER TEMPS AND RESULTANT WEAK INSTABILITY...
AND ANTICYCLONIC FLOW IN HIGH PRESSURE RIDGING SOUTHWARD FROM THE
COASTAL MIDDLE ATLANTIC (AND TO THE NORTH OF THE WEAK BACK DOOR
FRONT FORECAST TO STALL/WASH OUT OVER SC SUN)...SHOULD RESULT IN
LESSER CHANCES FOR CONVECTION THAN PREVIOUS DAYS. NONETHELESS...THE
CONTINUED PRESENCE OF A MID LEVEL SHEAR AXIS THAT EARLIER SAT WAS
ANALYZED FROM THE OH VALLEY TO THE NC COAST...AND APPROACH PASSAGE
OF A SOUTHERN STREAM DISTURBANCE OVER MO THIS AFTERNOON...WARRANTS A
SLIGHT CHANCE OF SHOWERS...MAINLY WITH HEATING SUN AFT-EVE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 305 PM...
RIDGE ALOFT OVER THE EASTERN UNITED STATES WITH SURFACE HIGH
PRESSURE OFFSHORE. WEAK WINDS...PRECIPITABLE WATERS NEAR ONE INCH
AND MINIMAL INSTABILITY AND POTENTIAL ENERGY SUGGESTS NO MORE THAN A
ONE IN FIVE CHANCE FOR MEASURABLE RAIN... DIURNALLY DRIVEN BY
AFTERNOON HEATING. LOW LEVEL THICKNESSES 25 TO 30 METERS ABOVE
NORMAL WITH SOME MINIMAL REDUCTION IN INSOLATION BY CLOUDS DURING
THE AFTERNOON. AFTERNOON HIGH TEMPERATURES 76 TO 81. LOW
TEMPERATURES IN THE MID TO UPPER 50S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 305 PM...
DEEP SLOWLY PROGRESSING TROUGH OR CUT OFF LOW OVER TEXAS WEDNESDAY
MORNING ATTEMPTS TO REACH THE CAROLINAS LATE IN THE PERIOD...
ALTHOUGH THE EAST COAST RIDGE RESISTS. MODEL SPREAD IN SOLUTIONS
REDUCES CONFIDENCE... AS DOES LACK OF DECENT RUN TO RUN CONTINUITY
WITHIN MODELS. MODELS FREQUENTLY TOO FAST WITH CUT OFF LOWS AND WILL
FAVOR THE SLOWER GFS TIMING... THOUGH THIS MAY ALSO BE TOO FAST.
WILL CONTINUE LOW CHANCES FOR MAINLY AFTERNOON SHOWERS OR A
THUNDERSTORM FROM PREVIOUS DAYS INTO MID WEEK WITH RAIN CHANCES
RISING TO 30 TO 40 PERCENT FOR FRIDAY AND SATURDAY AS WINDS ALOFT
BEGIN TO INCREASE.
AFTERNOON HIGH TEMPERATURES IN THE MID 70S. LOW TEMPERATURES MID AND
UPPER 50S.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
AS OF 210 PM SATURDAY...
VFR CONDITIONS...OUTSIDE OF SCATTERED SHOWERS AND STORMS MAINLY
THROUGH THIS EVENING...WILL CONTINUE THROUGH EARLY TONIGHT. THESE
CONDITIONS WILL THEN DETERIORATE TO IFR CEILINGS AND MVFR-IFR
VISIBILITIES FROM NE TO SW BETWEEN 04-10Z...OWING TO MOIST MARITIME
NORTHEASTERLY FLOW FROM OFF THE ATLANTIC. INDEED...AN EXPANSIVE AREA
OF MARINE STRATUS AND FOG HAD ADVECTED ALL THE WAY DOWN THE MID
ATLANTIC COASTAL WATERS TO NEAR KORF AS OF 18Z...AND THIS IS THE AIR
MASS THAT WILL CONTINUE SOUTHWESTWARD AND CAUSE THE DETERIORATING
AVIATION CONDITIONS ACROSS CENTRAL NC OVERNIGHT. CONDITIONS WILL
GRADUALLY IMPROVE WITH HEATING ON SUNDAY...WITH VISIBILITIES
BECOMING VFR AND CEILINGS LIFTING TO MVFR BETWEEN 13-16Z.
LOOKING BEYOND 18Z SUNDAY: SCT TO BKN 2000-3500 FT CLOUDS WILL
LINGER THROUGHOUT THE AFTERNOON SUN...AND ANY PARTIAL CLEARING LATE
IN THE DAY AND DURING THE EVENING WILL CAUSES AREAS OF FOG AND/OR
STRATUS TO REDEVELOP OVERNIGHT INTO EARLY MON. MORNING FOG OR
STRATUS AND SCT TO BKN AFTERNOON CONVECTIVE CLOUD BASES GENERALLY
BETWEEN 2500-3500 FT...AND ASSOCIATED ISOLATED TO WIDELY SCATTERED
CONVECTION...WILL THEN RULE THROUGH THE MIDDLE OF THE WORK WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...
LONG TERM...
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
306 PM EDT SAT MAR 17 2012
.SYNOPSIS...
A WEAK BACK DOOR COLD FRONT WILL SETTLE SOUTH THROUGH CENTRAL NC
THROUGH TONIGHT. HIGH PRESSURE WILL FOLLOW AND RIDGE INTO NC FROM
THE COASTAL MIDDLE ATLANTIC REGION THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM SATURDAY...
THROUGH EARLY TONIGHT: A SURFACE TROUGH/WEAK BACK DOOR COLD FRONT
STRETCHED AT 18Z FROM NEAR KMRH-KSOP-KEXX...WHILE THE MORE
NOTICEABLE COOLING RELATIVE TO TEMPERATURES OF FRI HAVE BEEN FOCUSED
OVER NORTHEASTERN NC/SOUTHEASTERN VA OWING TO A MORE ONSHORE
COMPONENT OF THE LOW LEVEL FLOW OFF OF COOL MIDDLE ATLANTIC COASTAL
WATERS. THIS TRAILING MARITIME PUSH...ASSOCIATED ENHANCED CUMULUS
FIELD PER VISIBLE SATELLITE IMAGERY...AND LOCATION OF A H85 TROUGH
AXIS PER REGIONAL VWP DATA...WILL LIKELY MARK THE APPROXIMATE
NORTHEASTWARD BOUND FOR THE POTENTIAL FOR DEEP CONVECTIVE
DEVELOPMENT THIS AFTERNOON. ISOLATED TO SCATTERED CONVECTION WILL
REMAIN POSSIBLE THROUGHOUT CENTRAL NC THIS AFTERNOON...GIVEN THE
PRESENCE OF THESE TWO CONVERGENCE-FOCUSING BOUNDARIES AMIDST
DEVELOPING WEAK TO MODERATE BOUNDARY LAYER (BL)-BASED INSTABILITY
PER MODIFIED 12Z PROXIMITY RAOBS FOR REPRESENTATIVE BL PARCELS OF
UPPER 70S-LOWER 80S TEMPERATURES OVER 50 TO 60 DEGREE
DEWPOINTS...FROM NW TO SE.
ALOFT...A PAIR OF VORTICITY MAXIMA STRETCHED FROM THE SC UPSTATE TO
WEST-CENTRAL NC -- THE FORMER APPARENT ON SATELLITE IMAGERY AND MUCH
STRONGER PER RUC MID LEVEL VORTICITY ANALYSES -- WILL DRIFT EASTWARD
IN WEAK (10-15 KTS) WESTERLY MID LEVEL STEERING FLOW. THESE FEATURES
MAY FOCUS CONVECTION FROM CENTRAL SC TO SE NC THIS AFTERNOON.
STORMS HAVE ALSO ALREADY FIRED ON THE EAST-FACING SLOPES OF THE
NC/VA BLUE RIDGE...AND THE CONVECTIVE ALLOWING MODELS (CAMS)
CONTINUE TO INDICATE THE POTENTIAL FOR THESE TO PROPAGATE ON THEIR
CONGLOMERATE OUTFLOWS -- AND WITH THE AFOREMENTIONED WEAK MID LEVEL
STEERING FLOW -- EASTWARD INTO THE WESTERN PIEDMONT THROUGH EARLY
THIS EVENING. SOME OF THIS ACTIVITY MAY CONTINUE EASTWARD ACROSS THE
REMAINDER OF CENTRAL NC OVERNIGHT...THOUGH CONFIDENCE IS NOT HIGH
ENOUGH TO CARRY MORE THAN A SLIGHT TO LOW CHANCE POP INTO THE NIGHT
TIME HOURS.
MOIST MARITIME NORTHEASTERLY FLOW FROM OFF THE ATLANTIC...WHICH HAS
ALREADY SUPPORTED AN EXPANSIVE AREA OF MARINE STRATUS AND FOG ALL
THE WAY DOWN THE MID ATLANTIC COASTAL WATERS TO NEAR KORF AS OF
18Z...WILL PROMOTE THE DEVELOPMENT OF LOW STRATUS AND FOG FROM NE TO
SW ACROSS THE CWFA BETWEEN 04-10Z. GIVEN A LACK OF APPRECIABLE CAA
EXCEPT OVER THE FAR NORTHEAST...LOWS WILL BE SIMILAR TO PREVIOUS
NIGHTS - 52 TO 58... COOLEST NORTHEAST.
OVERNIGHT: BEHIND THE FRONT...COOLER AND MOIST MARITIME
NORTHEASTERLY FLOW IS EXPECTED TO RESULT IN SLIGHTLY COOLER
OVERNIGHT LOWS TONIGHT...ESPECIALLY ACROSS THE NORTHEAST.
THEREFORE...AM EXPECTING MIN TEMPS TO RANGE FROM THE LOWER 50S
ACROSS THE NORTHEAST TO MID/UPPER 50S FURTHER SOUTH AND WEST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 305 PM...
RIDGE ALOFT OVER THE EASTERN UNITED STATES WITH SURFACE HIGH
PRESSURE OFFSHORE. WEAK WINDS...PRECIPITABLE WATERS NEAR ONE INCH
AND MINIMAL INSTABILITY AND POTENTIAL ENERGY SUGGESTS NO MORE THAN A
ONE IN FIVE CHANCE FOR MEASURABLE RAIN... DIURNALLY DRIVEN BY
AFTERNOON HEATING. LOW LEVEL THICKNESSES 25 TO 30 METERS ABOVE
NORMAL WITH SOME MINIMAL REDUCTION IN INSOLATION BY CLOUDS DURING
THE AFTERNOON. AFTERNOON HIGH TEMPERATURES 76 TO 81. LOW
TEMPERATURES IN THE MID TO UPPER 50S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 305 PM...
DEEP SLOWLY PROGRESSING TROUGH OR CUT OFF LOW OVER TEXAS WEDNESDAY
MORNING ATTEMPTS TO REACH THE CAROLINAS LATE IN THE PERIOD...
ALTHOUGH THE EAST COAST RIDGE RESISTS. MODEL SPREAD IN SOLUTIONS
REDUCES CONFIDENCE... AS DOES LACK OF DECENT RUN TO RUN CONTINUITY
WITHIN MODELS. MODELS FREQUENTLY TOO FAST WITH CUT OFF LOWS AND WILL
FAVOR THE SLOWER GFS TIMING... THOUGH THIS MAY ALSO BE TOO FAST.
WILL CONTINUE LOW CHANCES FOR MAINLY AFTERNOON SHOWERS OR A
THUNDERSTORM FROM PREVIOUS DAYS INTO MID WEEK WITH RAIN CHANCES
RISING TO 30 TO 40 PERCENT FOR FRIDAY AND SATURDAY AS WINDS ALOFT
BEGIN TO INCREASE.
AFTERNOON HIGH TEMPERATURES IN THE MID 70S. LOW TEMPERATURES MID AND
UPPER 50S.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
AS OF 210 PM SATURDAY...
VFR CONDITIONS...OUTSIDE OF SCATTERED SHOWERS AND STORMS MAINLY
THROUGH THIS EVENING...WILL CONTINUE THROUGH EARLY TONIGHT. THESE
CONDITIONS WILL THEN DETERIORATE TO IFR CEILINGS AND MVFR-IFR
VISIBILITIES FROM NE TO SW BETWEEN 04-10Z...OWING TO MOIST MARITIME
NORTHEASTERLY FLOW FROM OFF THE ATLANTIC. INDEED...AN EXPANSIVE AREA
OF MARINE STRATUS AND FOG HAD ADVECTED ALL THE WAY DOWN THE MID
ATLANTIC COASTAL WATERS TO NEAR KORF AS OF 18Z...AND THIS IS THE AIR
MASS THAT WILL CONTINUE SOUTHWESTWARD AND CAUSE THE DETERIORATING
AVIATION CONDITIONS ACROSS CENTRAL NC OVERNIGHT. CONDITIONS WILL
GRADUALLY IMPROVE WITH HEATING ON SUNDAY...WITH VISIBILITIES
BECOMING VFR AND CEILINGS LIFTING TO MVFR BETWEEN 13-16Z.
LOOKING BEYOND 18Z SUNDAY: SCT TO BKN 2000-3500 FT CLOUDS WILL
LINGER THROUGHOUT THE AFTERNOON SUN...AND ANY PARTIAL CLEARING LATE
IN THE DAY AND DURING THE EVENING WILL CAUSES AREAS OF FOG AND/OR
STRATUS TO REDEVELOP OVERNIGHT INTO EARLY MON. MORNING FOG OR
STRATUS AND SCT TO BKN AFTERNOON CONVECTIVE CLOUD BASES GENERALLY
BETWEEN 2500-3500 FT...AND ASSOCIATED ISOLATED TO WIDELY SCATTERED
CONVECTION...WILL THEN RULE THROUGH THE MIDDLE OF THE WORK WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...
LONG TERM...
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 PM EDT SAT MAR 17 2012
.SYNOPSIS...
A WEAK BACK DOOR COLD FRONT WILL SETTLE SOUTH THROUGH CENTRAL NC
THROUGH TONIGHT. HIGH PRESSURE WILL FOLLOW AND RIDGE INTO NC FROM
THE COASTAL MIDDLE ATLANTIC REGION THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM SATURDAY...
THROUGH EARLY TONIGHT: A SURFACE TROUGH/WEAK BACK DOOR COLD FRONT
STRETCHED AT 18Z FROM NEAR KMRH-KSOP-KEXX...WHILE THE MORE
NOTICEABLE COOLING RELATIVE TO TEMPERATURES OF FRI HAVE BEEN FOCUSED
OVER NORTHEASTERN NC/SOUTHEASTERN VA OWING TO A MORE ONSHORE
COMPONENT OF THE LOW LEVEL FLOW OFF OF COOL MIDDLE ATLANTIC COASTAL
WATERS. THIS TRAILING MARITIME PUSH...ASSOCIATED ENHANCED CUMULUS
FIELD PER VISIBLE SATELLITE IMAGERY...AND LOCATION OF A H85 TROUGH
AXIS PER REGIONAL VWP DATA...WILL LIKELY MARK THE APPROXIMATE
NORTHEASTWARD BOUND FOR THE POTENTIAL FOR DEEP CONVECTIVE
DEVELOPMENT THIS AFTERNOON. ISOLATED TO SCATTERED CONVECTION WILL
REMAIN POSSIBLE THROUGHOUT CENTRAL NC THIS AFTERNOON...GIVEN THE
PRESENCE OF THESE TWO CONVERGENCE-FOCUSING BOUNDARIES AMIDST
DEVELOPING WEAK TO MODERATE BOUNDARY LAYER (BL)-BASED INSTABILITY
PER MODIFIED 12Z PROXIMITY RAOBS FOR REPRESENTATIVE BL PARCELS OF
UPPER 70S-LOWER 80S TEMPERATURES OVER 50 TO 60 DEGREE
DEWPOINTS...FROM NW TO SE.
ALOFT...A PAIR OF VORTICITY MAXIMA STRETCHED FROM THE SC UPSTATE TO
WEST-CENTRAL NC -- THE FORMER APPARENT ON SATELLITE IMAGERY AND MUCH
STRONGER PER RUC MID LEVEL VORTICITY ANALYSES -- WILL DRIFT EASTWARD
IN WEAK (10-15 KTS) WESTERLY MID LEVEL STEERING FLOW. THESE FEATURES
MAY FOCUS CONVECTION FROM CENTRAL SC TO SE NC THIS AFTERNOON.
STORMS HAVE ALSO ALREADY FIRED ON THE EAST-FACING SLOPES OF THE
NC/VA BLUE RIDGE...AND THE CONVECTIVE ALLOWING MODELS (CAMS)
CONTINUE TO INDICATE THE POTENTIAL FOR THESE TO PROPAGATE ON THEIR
CONGLOMERATE OUTFLOWS -- AND WITH THE AFOREMENTIONED WEAK MID LEVEL
STEERING FLOW -- EASTWARD INTO THE WESTERN PIEDMONT THROUGH EARLY
THIS EVENING. SOME OF THIS ACTIVITY MAY CONTINUE EASTWARD ACROSS THE
REMAINDER OF CENTRAL NC OVERNIGHT...THOUGH CONFIDENCE IS NOT HIGH
ENOUGH TO CARRY MORE THAN A SLIGHT TO LOW CHANCE POP INTO THE NIGHT
TIME HOURS.
MOIST MARITIME NORTHEASTERLY FLOW FROM OFF THE ATLANTIC...WHICH HAS
ALREADY SUPPORTED AN EXPANSIVE AREA OF MARINE STRATUS AND FOG ALL
THE WAY DOWN THE MID ATLANTIC COASTAL WATERS TO NEAR KORF AS OF
18Z...WILL PROMOTE THE DEVELOPMENT OF LOW STRATUS AND FOG FROM NE TO
SW ACROSS THE CWFA BETWEEN 04-10Z. GIVEN A LACK OF APPRECIABLE CAA
EXCEPT OVER THE FAR NORTHEAST...LOWS WILL BE SIMILAR TO PREVIOUS
NIGHTS - 52 TO 58... COOLEST NORTHEAST.
OVERNIGHT: BEHIND THE FRONT...COOLER AND MOIST MARITIME
NORTHEASTERLY FLOW IS EXPECTED TO RESULT IN SLIGHTLY COOLER
OVERNIGHT LOWS TONIGHT...ESPECIALLY ACROSS THE NORTHEAST.
THEREFORE...AM EXPECTING MIN TEMPS TO RANGE FROM THE LOWER 50S
ACROSS THE NORTHEAST TO MID/UPPER 50S FURTHER SOUTH AND WEST.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...
SUN: THE WEAK SURFACE FRONT WILL MOVE SOUTH TO NEAR THE NC/SC STATE
LINE BY SUNDAY MORNING AS A STRONG (~1030MB) SURFACE HIGH CENTERED
OFF THE MID ATLANTIC COAST RIDGES INTO THE AREA FROM THE NORTHEAST.
AS STATED ABOVE...THE REGION WILL STILL REMAIN IN A FAVORABLE
PATTERN ALOFT TO SEE SOME WEAK SHORTWAVE DISTURBANCES MOVING ATOP
THE MID LEVEL RIDGE IN PLACE. WHILE PWAT VALUES WILL STILL BE HIGH
(1.2-1.3 INCHES)...A SLIGHTLY MORE STABLE POST FRONTAL AIR MASS WILL
BE IN PLACE...ESPECIALLY ACROSS THE NORTHEASTERN HALF OF THE
FORECAST AREA. MODELS PROG WEAK INSTABILITY OF 500 TO 800 J/KG
ACROSS THE SOUTHWESTERN HALF OF THE FORECAST AREA...CLOSER TO THE
STALL FRONTAL BOUNDARY. WITH ALL THE ABOVE IN MIND...WILL TREND POPS
FROM SLIGHT CHANCE ACROSS THE NORTHEAST TO CHANCE POPS FURTHER SOUTH
AND WEST AND WILL ALSO INCLUDE A MENTION OF THUNDER ACROSS THE
SOUTHWEST DUE TO THE PROXIMITY OF THE STALLED FRONTAL BOUNDARY.
HIGHS ARE EXPECTED TO RANGE FROM THE LOW/MID 70S ACROSS THE
NORTHEAST TO MID/UPPER 70S FURTHER SOUTH AND WEST.
SUNDAY NIGHT THROUGH MONDAY NIGHT: SURFACE HIGH PRESSURE CENTERED
OFF THE MID-ATLANTIC COAST IS FORECAST TO MOVE FURTHER OUT INTO THE
ATLANTIC SUNDAY NIGHT AND INTO MONDAY AS STALLED FRONTAL ZONE SOUTH
OF THE AREA CONTINUES TO WEAKEN/DISSIPATE.
MID-LEVEL RIDGE AXIS CENTERED FROM THE GULF OF MEXICO NORTHWARD
THROUGH THE GREAT LAKES REALLY BEGINS TO RESPOND TO THE UPSTREAM
HIGH AMPLITUDE TROUGH BARRELING ONTO THE WEST COAST. MODELS INDICATE
LOW-LEVEL THICKNESSES WILL TO BE THE HIGHEST ON MONDAY...WHICH WILL
LIKELY SUPPORT THE WARMEST DAY OF THE WEEK WITH AFTERNOON HIGHS
IN THE UPPER 70S TO LOWER 80S...WITH SOME OF THE WARMEST READINGS
ACROSS THE WESTERN PART OF THE STATE.
THIS STRONG DAYTIME HEATING WILL FUEL WEAK DESTABILIZATION WITH THE
RESERVOIR OF HIGH...1.1 TO 1.2" OF PWATS SUPPORTING ISOLATED/SLIGHT
CHANCE DIURNAL CONVECTION...WITH THE POTENTIAL FOR HIGHER POPS
ACROSS THE EAST WHERE MODELS DEPICT A LOW-LEVEL CONVERGENCE ZONE
ALONG AN INVERTED COASTAL TROUGH LIKE FEATURE THAT COULD ENHANCE
A SEABREEZE BOUNDARY. ADDITIONALLY...HIGHER POPS MAY ALSO BE NEEDED
ON MONDAY IF SOME OF THE MODELS ARE CORRECT WITH SHOWING AN UPPER
SHORTWAVE VORT DISTURBANCE DIVING SOUTH/SOUTHEAST ATOP THE RIDGE
AXIS AND ACROSS THE AREA. CONFIDENCE WITH THIS FEATURE IS LOW AT
THIS TIME AND WILL KEEP POPS AT SLIGHT CHANCE...EXCEPT A SMALL
CHANCE ACROSS THE SOUTHEAST.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
...UNSEASONABLY WARM TEMPERATURES WILL CONTINUE THROUGH THE UPCOMING
WORK WEEK...
THERE IS GOOD MODEL AGREEMENT AMONG THE VARIOUS DETERMINISTIC AND
ENSEMBLE GUIDANCE THAT A CUT-OFF LOW WILL EVOLVE OVER THE SOUTHWEST
DURING THE TUESDAY/WEDNESDAY TIMEFRAME...WITH A SLOW EAST/
NORTHEASTWARD PROGRESSION THROUGH THE REMAINDER OF THE PERIOD. GIVEN
CUT-OFF STRUCTURE...WILL GIVE GREATER WEIGHT TO THE SLOWER MODEL
SOLUTIONS WHICH DELAY ANY IMPACTS ON SENSIBLE WEATHER UNTIL LATE
FRIDAY/SATURDAY. AS SUCH CENTRAL NC WILL CONTINUE TO SEE
UNSEASONABLY WARM TEMPERATURES DOWNSTREAM OF THE SYSTEM IN THE
ANOMALOUSLY HIGH HEIGHTS PARKED OVER THE EASTERN US. EXPECT HIGHS
EACH DAY IN THE MID TO UPPER 70S WITH MILD NIGHTTIME LOWS IN THE MID
50S. ONSHORE LOW-LEVEL FLOW WILL SUPPORT ISOLATED AND MAINLY
DIURNALLY DRIVEN CONVECTION TIED TO MESOSCALE INFLUENCES/FORCING
SUCH AS LOCALLY ENHANCE CONVERGENCE ZONES ALONG THE SEABREEZE NEAR
THE COAST...AND OUTFLOW BOUNDARIES ORIGINATING FROM CONVECTION
FIRING ALONG THE HIGHER TERRAIN.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 210 PM SATURDAY...
VFR CONDITIONS...OUTSIDE OF SCATTERED SHOWERS AND STORMS MAINLY
THROUGH THIS EVENING...WILL CONTINUE THROUGH EARLY TONIGHT. THESE
CONDITIONS WILL THEN DETERIORATE TO IFR CEILINGS AND MVFR-IFR
VISIBILITIES FROM NE TO SW BETWEEN 04-10Z...OWING TO MOIST MARITIME
NORTHEASTERLY FLOW FROM OFF THE ATLANTIC. INDEED...AN EXPANSIVE AREA
OF MARINE STRATUS AND FOG HAD ADVECTED ALL THE WAY DOWN THE MID
ATLANTIC COASTAL WATERS TO NEAR KORF AS OF 18Z...AND THIS IS THE AIR
MASS THAT WILL CONTINUE SOUTHWESTWARD AND CAUSE THE DETERIORATING
AVIATION CONDITIONS ACROSS CENTRAL NC OVERNIGHT. CONDITIONS WILL
GRADUALLY IMPROVE WITH HEATING ON SUNDAY...WITH VISIBILITIES
BECOMING VFR AND CEILINGS LIFTING TO MVFR BETWEEN 13-16Z.
LOOKING BEYOND 18Z SUNDAY: SCT TO BKN 2000-3500 FT CLOUDS WILL
LINGER THROUGHOUT THE AFTERNOON SUN...AND ANY PARTIAL CLEARING LATE
IN THE DAY AND DURING THE EVENING WILL CAUSES AREAS OF FOG AND/OR
STRATUS TO REDEVELOP OVERNIGHT INTO EARLY MON. MORNING FOG OR
STRATUS AND SCT TO BKN AFTERNOON CONVECTIVE CLOUD BASES GENERALLY
BETWEEN 2500-3500 FT...AND ASSOCIATED ISOLATED TO WIDELY SCATTERED
CONVECTION...WILL THEN RULE THROUGH THE MIDDLE OF THE WORK WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...KRR/CBL
LONG TERM...CBL
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
252 PM EDT SAT MAR 17 2012
.SYNOPSIS...
A WEAK SURFACE TROUGH MEANDERING ACROSS THE REGION WILL BRING
ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THE WEEKEND AND INTO
MONDAY. OTHERWISE...ABOVE NORMAL TEMPERATURES WILL PREVAIL THROUGH
MUCH OF NEXT WEEK...AS AN UPPER RIDGE OVER THE REGION AMPLIFIES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SATURDAY...EAST-WEST BOUNDARY SEPARATING NRLY AND SRLY
WINDS VERY ROUGHLY BISECTING THE REGION RIGHT NOW/CLOSE TO THE STATE
LINE. RUC ANALYSIS SUGGESTS THIS BOUNDARIES VERTICAL IDENTITY
EXTENDS TO ABOUT 925MB OR 3KFT. HIGHER DEWPOINTS AND LOWER LCLS
CONTINUE TO BE FOUND TO THE NORTH OF THIS BOUNDARY BUT ALAS CU
FIELDS CONTINUE TO BE MINIMAL. RADAR PRESENTATION OF SEA BREEZE ALSO
SUGGESTS A DEPTH OF ABOUT 3KFT. IN THE ABSENCE OF SYNOPTIC SCALE
LIFT NEITHER OF THESE ARE GOING TO BE TERRIBLY EFFECTIVE IN LEADING
TO CONVECTION WITH LFCS CURRENTLY CLOSER TO 6KFT. THIS SYNOPTIC
ASCENT THOUGH GENTLE WILL BE PROVIDED BY THE SHORTWAVE CURRENTLY
COMING OUT OF EASTERN TN. THERE IS STILL A SHORT WINDOW OF
OPPORTUNITY FOR CONVECTION TODAY FROM ABOUT 20 OR 21 UTC THROUGH
SUNDOWN AT WHICH TIME ANY COVERAGE OF STORMS WILL QUICKLY RUN OUT
OF DIURNALLY DRIVEN INSTABILITY. AS SEEN LAST NIGHT HOWEVER IT IS
DIFFICULT TO GO WITH A COMPLETELY DRY OVERNIGHT FORECAST IN LIGHT
OF A TRAILING 10 S-1 VORT OR TWO STILL PROGGED TO MOVE ACROSS.
THUS-20 POPS CARRIED OVERNIGHT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...A WEAK E-W SURFACE BOUNDARY WILL MEANDER
SOUTHWARD OVER OUR FORECAST ZONES ON SUNDAY. DESPITE REMAINING
BENEATH AN UPPER RIDGE...ENOUGH COLUMN MOISTURE AND INSTABILITY
WILL EXIST TO MAINTAIN ISOLATED SHOWERS AND THUNDERSTORMS SUNDAY
AND MONDAY. IT SHOULD BE NOTED THE ENVIRONMENTAL WIND FIELD WILL
REMAIN UNIMPRESSIVE AND ANY STORMS THAT FORM WILL FAVOR SURFACE
HEATING AND WILL LIKELY EXHIBIT PULSE CHARACTERISTICS.
BY MONDAY WE MAY SEE THE BOUNDARY LIFTING BACK NORTH. MOISTURE AND
INSTABILITY REMAIN SIMILAR AND HAVE EXTENDED ISOLATED POP VALUES
INTO MONDAY. GIVEN THE EXCESSIVE WARMTH...SEA-BREEZE CONVERGENCE
MAY ALSO PLAY A ROLE INITIATING CONVECTION SUNDAY AND MONDAY IN
THE AFTERNOON AND EARLY EVENINGS. MILD TEMPERATURES WILL PREVAIL
BOTH DAYS BENEATH THE THERMAL RIDGE...JUST A FEW DEGREES COOLER
ACROSS THE NORTHERN ZONES SUNDAY BEHIND THE FRONT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...DEEP 5H TROUGH OVER THE SOUTHWEST...A FAMILIAR
SIGHT THIS YEAR...AT THE START OF THE PERIOD PROVIDES PLENTY OF
UNCERTAINTY IN THE LONG RANGE PERIOD. MEDIUM RANGE GUIDANCE IN
DECENT AGREEMENT ON THE TROUGH TURNING INTO A 5H CUTOFF...BUT LITTLE
ELSE. TIMING REMAINS A BIG QUESTION AS SURFACE AND UPPER RIDGING
ALONG THE EAST COAST IS SURE TO HOLD STRONGER THAN GUIDANCE
INDICATES...MEANING THE MEDIUM RANGE SOLUTIONS ARE ALL LIKELY TOO
FAST MOVING THE 5H TROUGH/CUTOFF LOW EAST. HPC IS ALSO FAVORING A
SLOWER SOLUTION. THE END RESULT WILL BE A SUMMER-LIKE PATTERN WITH
STRENGTHENING 5H RIDGE AND BERMUDA HIGH. DIURNAL/SEA BREEZE
CONVECTION MAY DEVELOP TUE/WED BUT BUILDING 5H RIDGE AS THE UPPER
TROUGH/LOW MOVES EAST WILL HELP SUPPRESS UPWARD MOTION THU AND MAYBE
FRI DEPENDING ON HOW SLOW THE TROUGH/LOW MOVES EAST. COLD FRONT
MOVING INTO THE REGION LATE IN THE PERIOD WILL PROVIDE THE BEST
CHANCES FOR WIDESPREAD PRECIP. AREA OF DEEP MOISTURE AHEAD OF THE
FRONT IS LIMITED AND IT LOOKS LIKE THE BEST DYNAMICS PASS TO THE
NORTH. GIVEN THE UNCERTAINTY AND THE MARGINAL CONDITIONS DO NOT FEEL
ANYTHING MORE THAN A LOW CHANCE POP IS WARRANTED. TEMPERATURES WILL
RUN ABOVE TO WELL ABOVE CLIMO WITH HIGHS IN THE MID TO UPPER 70S AND
LOWS IN THE MID 50S.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 19Z...TERMINALS ARE VFR THIS AFTERNOON. SKIES ARE GENERALLY
SCATTERED...AND CUMULUS HAS JUST BEGUN TO DEVELOP.
A WEAK COLD FRONT WILL APPROACH FROM THE NORTH TODAY. A PIEDMONT
TROUGH WILL EXIST FROM KLBT TO KFLO AND A SEA BREEZE WILL DEVELOP
AND MOVE SLIGHTLY INLAND OF THE COASTAL TERMINALS LATER THIS
AFTERNOON. SUFFICIENT INSTABILITY WILL EXIST NEAR THESE FOCUS AREAS
FOR ISOLATED TO WIDELY SCATTERED SHOWERS TO OCCUR THROUGH MUCH OF
THIS TAF VALID PERIOD. ISOLATED THUNDERSTORMS WILL ALSO DEVELOP ONCE
THE CONVECTIVE TEMPERATURE IS REACHED OVER THE NEXT SEVERAL HOURS.
CONFIDENCE IS HIGHEST THAT THUNDERSTORMS WILL OCCUR NEAR THE KILM
AND KLBT TERMINALS LATER THIS AFTERNOON WITH TEMPO MVFR/IFR POSSIBLE.
OTHERWISE...MAINLY SHOWERS CAN BE EXPECTED. VFR CAN BE EXPECTED
OUTSIDE OF SHOWERS AND THUNDERSTORMS. DUE TO THE PROXIMITY OF THE
FRONT PRECIPITATION SHOULD LINGER THROUGH MUCH OF THE EVENING AND
OVERNIGHT HOURS.
WINDS WILL BE SOUTHWEST TODAY 5-10 KNOTS...BECOMING SOUTH AT THE
COASTAL TERMINALS IN THE NEXT SEVERAL HOURS DUE TO THE SEA
BREEZE. THIS EVENING AND OVERNIGHT WINDS WILL LIKELY BECOME LIGHT
SOUTHWEST AT THE SOUTHERN TERMINALS AND LIGHT AND VARIABLE AT KILM
AND KLBT. AT KILM AND KLBT THERE IS A GOOD CHANCE FOR IFR STRATUS TO
DEVELOP... WHILE MVFR VISIBILITIES WILL BE MOST LIKELY AT THE
REMAINING TERMINALS. EXPECT MVFR CONDITIONS OR GREATER 14-16Z WITH
SHOWERS DEVELOPING.
EXTENDED OUTLOOK...THROUGH THE PERIOD...MORNING FOG/MVFR...SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS IN THE AFTERNOON...THROUGH THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SATURDAY...WINDSHIFT BOUNDARY WILL BE LURKING NOT TOO FAR
TO THE NORTH OF THE AREA FOR MOST OF THE PERIOD. THIS BOUNDARY HAS
MADE MORE SOUTHERN PROGRESS OVER LAND THAN OVER WATER AND THIS WILL
LIKELY HOLD TRUE OVERNIGHT. THIS WILL PRECLUDE ANY NORTHERLY WIND
COMPONENT FROM ENTERING THE FORECAST AREA ALTHOUGH NORTHERN ZONES
MAY GO VERY LIGHT AND VARIABLE AS A RESULT OF HE PROXIMITY OF THE
TROUGH. LIGHT S TO SWRLY FLOW CAPPED AT 10 KTS WILL REMAIN IN PLACE
ELSEWHERE AS WEAK BERMUDA HIGH PRESSURE CONTINUES TO BE THE DOMINANT
WIND MAKER. SEAS REMAINING RELATIVELY DIMINUTIVE AT 2 TO 3 FT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...BY DAYBREAK SUNDAY NE WINDS WILL PREVAIL N
OF CAPE FEAR AS AN E-W FRONTAL BOUNDARY SLIPS SLOWLY SOUTHWARD.
WIND SPEEDS WILL HOLD BELOW 20-25 KNOTS SO ADVISORIES WILL NOT
BE NEEDED. THE FRONT MAY NOT MAKE IT TO WINYAH BAY LATE SUNDAY
AND COULD MOVE BACK NORTH SUNDAY NIGHT INTO MONDAY. THUS WE MAY
VERY WELL SEE A VARIABLE WIND DIRECTION SUNDAY AND MONDAY WITH
LIGHT SPEEDS OVERALL. NO PROBLEMS WITH SEAS...ESSENTIALLY 2-3 FT
IN A MIX OF SE WAVES AND SHORTER PERIOD SSW WIND CHOP. THE WEAK
FRONTAL BOUNDARY MAY TRIP OFF ISOLATED TSTMS NEAR OR OVER THE
WATERS. MARINERS SHOULD CONSULT RADAR TRENDS BEFORE HEADING OUT
SUNDAY AND MONDAY.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...MAJORITY OF THE PERIOD WILL BE MARKED BY SOUTH
TO SOUTHEAST WINDS AT OR BELOW 10 KT. BERMUDA HIGH WILL BE THE MAIN
FEATURE THOUGH LATE IN THE PERIOD A COLD FRONT WILL APPROACH FROM
THE WEST. TIMING OF THE COLD FRONT REMAINS A BIG QUESTION...BUT EVEN
THE FASTEST SOLUTION KEEPS THE FRONT TO THE WEST THROUGH THU
EVENING. THE FASTER SOLUTION DOES LEAD TO A PINCHED GRADIENT THU
WHICH WOULD PUSH SOUTHERLY FLOW CLOSE TO 20 KT. HOWEVER THE SLOWEST
AND THE FASTEST SOLUTION IS FAVORED. SO WHILE THERE MAY BE A
MARGINAL INCREASE IN SPEEDS THU AS GRADIENT TIGHTENS A LITTLE SPEEDS
SHOULD REMAIN UNDER 15 KT. SEAS WILL RUN 2 TO 3 FT TUE INTO WED BUT
A BUILDING EAST TO SOUTHEAST SWELL LATE IN THE PERIOD WILL PUSH SEAS
INTO THE 3 TO 5 FT RANGE THU.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MBB
SHORT TERM...MJC
LONG TERM...III
AVIATION...MRR/MBB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1230 PM EDT SAT MAR 17 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DRIFT SOUTH OVER THE CAROLINAS INTO EARLY
SUNDAY...BRINGING A FEW SHOWERS AND THUNDERSTORMS. WARM AND GENERALLY
DRY CONDITIONS ARE EXPECTED MUCH OF NEXT WEEK...AS AN UPPER RIDGE
AMPLIFIES OVER THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM SATURDAY...A BOUNDARY LIES NEARLY STALLED ALONG
NORTHERNMOST ZONES. INTERESTINGLY, SOME HIGHER DEWPOINTS HAVE POOLED
NORTH OF THIS WINDSHIFT LINE. RUC ANALYSIS IS THUS SHOWING SOME
INSTABILITY AND LOWER LCLS DEVELOPING IN THESE AREAS WHICH EXTEND
INTO BLADEN AND ROBESON AND PARTS OF PENDER CTYS. THIS MAY END UP
BEING WHERE CONVECTION INITIATES FIRST ALTHOUGH LATER INDICATION BY
DEVELOPMENT OF CU FIELDS WILL ADD GREATER CONFIDENCE. 12Z GFS AND
WRF BOTH SEEM TO SUPPORT THIS IDEA. OF LESSER CERTAINTY IS THE MODEL
DEPICTION OF ANOTHER BOUNDARY DEVELOPING ROUGHLY PARALLEL TO THE SEA
BREEZE...IF NOT THE ACTUAL SEABREEZE...ACROSS SC ZONES. (IT LOOKS A
LITTLE TOO FAR INLAND TO BE THE ACTUAL SEABREEZE WHICH IS NOT
EXPECTED TO MOVE FAR OR FAST INLAND TODAY). TIMING IS GOING TO BE A
LITTLE LATER THAN PREV THOUGHT SO FCST HAS BEEN ADJUSTED ACCORDINGLY.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 3:00 AM SATURDAY...MID LEVEL HEIGHTS WILL
BUILD THROUGH THE PERIOD ALTHOUGH WITH THE DEVELOPING HIGH AMPLITUDE
PATTERN THE AREA REMAINS ON THE EASTERN SIDE OF THE MAIN RIDGE AXIS.
AT THE SURFACE A DECAYING FRONT ALONG WITH ANY NUMBER OF WEAK
EMBEDDED SHORTWAVES OR CONVECTIVE VORTICIES WILL BE THE CATALYST FOR
CONVECTION SUNDAY. THE MET GUIDANCE REMAINS MUCH HIGHER WHEN
COMPARED TO THE GFS MAV NUMBERS BUT WITH A SUMMER LIKE PATTERN THESE
NUMBERS CAN BE OF LIMITED UTILITY WITH SUCH WEAK FORCING. I HAVE
MAINTAINED THE LOW CHANCE POPS FOR SUNDAY CITING THE FORMER. CANNOT
RULE OUT SEA BREEZE ACTIVITY ALONG WITH THE RESIDUAL BOUNDARIES AND
SUBTLE SHORTWAVES FOR ACTIVITY MONDAY ALTHOUGH I DID INCREMENTALLY
DECREASE POPS AS THE FRONT WILL BE ALL BUT DISSIPATED.
TEMPERATURE GUIDANCE HAS WARMED SLIGHTLY FOR SUNDAY AND REMAINS
SIMILAR FOR THE REMAINDER OF THE PERIOD.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3:00 AM SATURDAY...FORECAST CHALLENGES WITH
REGARDS TO THE EXTENDED CONTINUE TO BE FOCUSED IN THE WESTERN AND
CENTRAL U.S. WITH THE TIMING OF THE MASSIVE TROUGH AND EVENTUAL
CUTOFF AND ITS SLOW MOVEMENT. FOR OUR AREA...I HAVE MAINTAINED THE
MAINLY DIURNAL CONVECTION WITH THE SUMMER LIKE PATTERN AND BERMUDA
HIGH PRESSURE. POPS DO DECREASE INCREMENTALLY LATE AS THE RIDGE
INTENSIFIES AS THE TROUGH PROGRESSES EAST. NO CHANGES TO TEMPERATURE
FORECAST.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 18Z...TERMINALS ARE VFR THIS AFTERNOON. SKIES ARE GENERALLY
SCATTERED...AND CUMULUS HAS JUST BEGUN TO DEVELOP.
A WEAK COLD FRONT WILL APPROACH FROM THE NORTH TODAY. A PIEDMONT
TROUGH WILL EXIST FROM KLBT TO KFLO AND A SEA BREEZE WILL DEVELOP
AND MOVE SLIGHTLY INLAND OF THE COASTAL TERMINALS LATER THIS
AFTERNOON. SUFFICIENT INSTABILITY WILL EXIST NEAR THESE FOCUS AREAS
FOR ISOLATED TO WIDELY SCATTERED SHOWERS TO OCCUR THROUGH MUCH OF
THIS TAF VALID PERIOD. ISOLATED THUNDERSTORMS WILL ALSO DEVELOP ONCE
THE CONVECTIVE TEMPERATURE IS REACHED OVER THE NEXT SEVERAL HOURS.
CONFIDENCE IS HIGHEST THAT THUNDERSTORMS WILL OCCUR NEAR THE KILM
AND KLBT TERMINALS LATER THIS AFTERNOON WITH TEMPO MVFR/IFR POSSIBLE.
OTHERWISE...MAINLY SHOWERS CAN BE EXPECTED. VFR CAN BE EXPECTED
OUTSIDE OF SHOWERS AND THUNDERSTORMS. DUE TO THE PROXIMITY OF THE
FRONT PRECIPITATION SHOULD LINGER THROUGH MUCH OF THE EVENING AND
OVERNIGHT HOURS.
WINDS WILL BE SOUTHWEST TODAY 5-10 KNOTS...BECOMING SOUTH AT THE
COASTAL TERMINALS IN THE NEXT SEVERAL HOURS DUE TO THE SEA
BREEZE. THIS EVENING AND OVERNIGHT WINDS WILL LIKELY BECOME LIGHT
SOUTHWEST AT THE SOUTHERN TERMINALS AND LIGHT AND VARIABLE AT KILM
AND KLBT. AT KILM AND KLBT THERE IS A GOOD CHANCE FOR IFR STRATUS TO
DEVELOP... WHILE MVFR VISIBILITIES WILL BE MOST LIKELY AT THE
REMAINING TERMINALS. EXPECT MVFR CONDITIONS OR GREATER 14-16Z WITH
SHOWERS DEVELOPING.
EXTENDED OUTLOOK...THROUGH THE PERIOD...MORNING FOG/MVFR...SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS IN THE AFTERNOON...THROUGH THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM...LIGHT BERMUDA HIGH-INDUCED SWRLY WINDS TO AVERAGE
ABOUT 10 KT TODAY. SEAS RUNNING 2 TO 3 FT. DOMINANT PERIOD AT BOTH
41013 AND 41036 AROUND 9 SECONDS WITH A LESSER SPIKE SHOWING UP IN
SPECTRAL GRAPHS AT A 4 SEC WIND CHOP. THESE CONDITIONS WILL PERSIST
THROUGH THE PERIOD.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3:00 AM SATURDAY...VERY LIGHT PRESSURE PATTERN WILL PREVAIL
WITH A FRONT BISECTING THE WATERS FROM EAST TO WEST INITIALLY.
WEAK NORTHEASTERLY FLOW DEVELOPS FOR A SHORT TIME MONDAY BUT WILL
GIVE WAY TO A EASTERLY FLOW LATE VIA THE SEABREEZE AND MORE-SO THE
SYNOPTIC FLOW. GENERALLY SPEAKING WIND SPEEDS WILL BE TEN KNOTS OR
LESS. THE LATEST SWAN RUN SHOWS 2-3 FOOT SEAS WHICH SEEM MORE THAN
REASONABLE CONSIDERING THE TEPID WIND FIELDS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3:00 AM SATURDAY...WITH A SUMMERTIME PATTERN IN
PLACE...BERMUDA HIGH PRESSURE...EXPECT SOUTH TO SOUTHEAST WINDS
THROUGH THE PERIOD. SEABREEZE CIRCULATION MAY BE ENHANCED BY THE
STILL RELATIVELY COOLER WATER TEMPERATURES. CAVEAT TO THIS
FORECAST IS THE MID LEVEL LOW THE GFS IS ADVERTISING AND IF A WEAK
SURFACE LOW DEVELOPS. HAVE DISREGARDED THIS SOLUTION AS OF NOW AS
IT APPEARS TO BE CONVECTIVELY INDUCED. SEAS WILL SLOWLY INCREASE
AS THE FETCH PERSISTS FROM 2-3 FEET TO 2-4 FEET. A FEW FIVE
FOOTERS CANNOT BE RULED OUT. WAVE SPECTRUM WILL PRIMARILY CONSIST
OF LOCAL WIND GENERATED WAVES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...MBB
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
310 PM CDT SAT MAR 17 2012
.NEAR TERM...
LOW LEVEL MOISTURE CONTINUES TO SURGE NORTHWARD INTO THE AREA...
AHEAD OF A DEEPENING LOW PRESSURE CENTER BACK IN EASTERN MT. A
QUASI-STATIONARY BOUNDARY EXTENDED SOUTHERN MANITOBA AND WESTERN
ONTARIO...JUST NORTH OF THE FGF FORECAST AREA. AT 2PM...DWPTS OF
50F OR GREATER EXTENDED FROM ABERDEEN...THROUGH COOPERSTOWN...TO
THIEF RIVER FALLS AND ROSEAU. SOME +60F DEWPOINT AIR WAS EDGING
TOWARDS THE EXTREME SOUTHEASTERN ND AND WEST CENTRAL MN. WITH
MODERATE SOUTHERLY LOW LEVEL AND BOTH ADVECTING WARMTH AND
MOISTURE...MOST AREAS WILL SEE MOTTLED SUNSHINE AND NEAR RECORD
TEMPERATURES THROUGH THE AFTERNOON AND EARLY EVENING.
NEAR SURFACE AIRMASS IS BECOMING INCREASING UNSTABLE ACROSS MUCH OF
WEST CENTRAL AND NORTHWEST MN ATTM. RUC SHOWS HIGHEST ELEVATED
INSTABILITY MOVING INTO NORTHWEST AND NCNTRL MN THROUGH THE LATE
AFTERNOON AND EARLY EVENING. HAVE KEEP SLIGHT CHC OF TSTMS OVER
NCNTRL MN AS PER PREVIOUS PACKAGE FOR THE EVENING HOURS.
.SHORT TERM... TONIGHT THROUGH TUESDAY.
INCREASING H850 WINDS AND MOISTURE ADVECTION OVERNIGHT WILL HELP TO
SATURATE THE NEAR SFC AIRMASS AND TO DEVELOP PATCHY FOG AND MIST
CONDITIONS FROM THE OVERNIGHT INTO EARLY MORNING PERIOD...BEGINNING
ACROSS THE SOUTHERN RED RIVER BASIN AND ADVECTING NORTHWARD.
ON SUNDAY...PATCHY FOG AND MIST SHOULD PERSIST INTO MID MORNING...
WITH BREAKS APPEARING IN THE CLOUDS THROUGH THE FORENOON ALLOWING
FOR SOME ADDITIONAL WARMING BY MIDDAY. ABUNDANT SUNSHINE AND
INCREASING INSTABILITY THROUGH THE AFTERNOON COULD GIVE RISE TO
SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM OR TWO BY EARLY
EVENING...WITH BOUNDARY FORCING STRONGEST NEARER THE CANAM BORDER.
MONDAY...MOST OF THE AREA SHOULD SEE SOME RAINSHOWER ACTIVITY WITH
EMBEDDED THUNDERSTORMS A STRONG POSSIBILITY. LOW PRESSURE IS
EXPECTED TO DEEPEN INTO THE WESTERN DAKOTAS BY MONDAY MORNING WITH
ALL OF EASTERN ND AND WESTERN MN IN AN AREA OF INCREASED LOW LEVEL
MOISTURE AHEAD OF AN APPROACHING COLD FRONTAL BOUNDARY.
THUNDERSTORMS ARE MOST LIKELY ON MONDAY AFTERNOON ALONG THE RED
RIVER VALLEY AND POINTS EASTWARD INTO NORTHERN MINNESOTA TROUGH THE
EVENING HOURS. SOUTH WINDS SHOULD BE QUITE GUSTY ON MONDAY AS WELL
WITH TEMPERATURES ONCE AGAIN REACHING INTO RECORD SETTING VALUES.
TUESDAY...DEEP CONVECTION SHOULD HAVE MOVED INTO CENTRAL AND
NORTHCENTRAL MN BY TUESDAY MORNING...BUT MODEL GUIDANCE IS STILL
INDECISIVE ON WHETHER THE SFC FRONT WILL PUSH THROUGH THE RED RIVER
VALLEY BY THEN OR LINGER THROUGH THE DAY. FOR NOW...HAVE STUCK
CLOSER TO THE SLOWER GFS SOLUTION...AND EXPECT SOME CONVECTION TO
REDEVELOP ALONG AND EAST OF THE RED RIVER VALLEY INTO MIDDAY TUESDAY
BEFORE FRONTAL PASSAGE PUSHES ALL RAIN INTO EASTERN MINNESOTA FOR
THE LATE AFTERNOON AND EVENING PERIODS. OVERALL... TEMPERATURES
SHOULD BE MUCH COOLER WITH WIDESPREAD CLOUD COVER EARLY... AND WINDS
TURNING FROM WEST TO NORTHWEST LATE.
.LONG TERM... WEDNESDAY THROUGH FRIDAY.
A MILD AND GENERALLY DRY EXTENDED FORECAST PERIOD IS EXPECTED FOR
THE EQUINOX WEEK OF MARCH AS THE MAIN JET STREAM CONTINUES TO REMAIN
NORTH OF THE INTERNATIONAL BORDER. LOW LEVEL MOISTURE RETURN TO THE
NORTHERN PLAINS WILL BE SCANT DUE TO CUTOFF LOW IN THE SOUTHERN
MISSISSIPPI RIVER VALLEY. DUE TO NO SNOW COVER PRESENT...DAILY HIGH
TEMPERATURES SHOULD STILL AVERAGE AT LEAST 15 DEGREES WARMER THAN
SEASONAL NORMALS FOR LATE MARCH. THE SURFACE STORM TRACK SHOULD
REMAIN NORTH OF THE INTERNATIONAL BORDER INTO NEXT WEEKEND.
&&
.AVIATION...
LOW LEVEL MOISTURE ADVECTING NORTHWARD OVERNIGHT SHOULD ALLOW MVFR
CEILINGS TO CONTINUE TO MOVE NORTHWARD THIS EVENING. IN
ADDITION...SOUNDINGS HINT AT POSSIBILITY OF -DZ AND BR DEVELOPMENT
THIS EVENING...ESPECIALLY IN THE EAST AND SOUTH. THIS AREA WILL HAVE
THE DEEPER MOISTURE PRESENT WITH THE RETURN FLOW. THUS...HAVE
DECREASED VISIBILITIES AT KBJI AND ADDED -DZ AFTER SUNSET. KFAR WILL
ALSO HAVE TO BE MONITORED AS WELL FOR POSSIBLE FOG AND DRIZZLE
DEVELOPMENT. SOUTHEASTERLY SURFACE WINDS WILL INCREASE SUNDAY
MORNING AS THE PRESSURE GRADIENT TIGHTENS UP. AT THE PRESENT
TIME...EXPECT SUSTAINED WINDS OF 15 TO 20 KNOTS WITH GUSTS AROUND 25
KNOTS TO BE PREVALENT THROUGH THE MORNING HOURS ON SUNDAY.
&&
.HYDROLOGY...
RIVER FLOOD WARNING FOR FARGO AT THE RED RIVER CONTINUES. THE RED
RIVER CONTINUES TO RISE SLOWLY AND IS STILL FORECAST TO REACH A
FOOT ABOVE FLOOD STAGE EARLY NEXT WEEK. OTHER POINTS DOWNSTREAM OF
FARGO ALONG THE RED ARE SEEING WITHIN THE BANK RISES. SOME OF THE
TRIBUTARIES OVER NE ND/NW MN WILL ALSO SEE WITHIN THE BANK RISES.
THE CURRENT FCST OF RAINFALL FROM THE UPCOMING SYSTEM SHOULD NOT
BE ENOUGH TO ALTER RIVER FORECASTS GREATLY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
GUST/BRAMER/SPEICHER
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
643 PM EDT SAT MAR 17 2012
.SYNOPSIS...
WITH HIGH PRESSURE ANCHORED OFF THE EAST COAST...A SOUTHERLY FLOW
AROUND THE HIGH WILL ALLOW AN UNSEASONABLY WARM AIRMASS TO PERSIST
THROUGH MUCH OF THE UPCOMING WEEK. A MID LEVEL DISTURBANCE
INTERACTING WITH THE UNSTABLE AIRMASS WILL PRODUCE THUNDERSTORMS
MAINLY LATE TONIGHT INTO SUNDAY. THE FLOW OVER THE OHIO VALLEY
WILL BECOME ANTICYCLONIC AND WARMER AIR WILL MOVE IN ALOFT ON
MONDAY WHICH WILL BRING AN END TO THE THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
ISOLATED SHOWERS ARE OCCURRING WITH INSTABILITY INCREASING
SLIGHTLY DUE TO DAYTIME HEATING. AFTER A LULL AROUND
SUNSET...ACTIVITY WILL INCREASE IN COVERAGE AND INTENSITY LATER
TONIGHT WHEN THE ATMOSPHERE DESTABILIZES DUE TO COOLING ALOFT
ASSOCIATED WITH A SHORT WAVE MOVING UP FROM THE SOUTHWEST. KEPT
LIKELY POPS WITH HIGHEST VALUES NEAR THE OHIO RIVER. TEMPERATURES
WILL FALL TO THE UPPER 50S FOR LOWS...ABOVE NORMAL HIGHS IN THE
LOWER 50S FOR THIS PERIOD.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
THUNDERSTORMS WILL LIKELY PERSIST ON SUNDAY AS THE SHORT WAVE
CRAWLS NORTH AND INSTABILITY LINGERS INTO THE AFTERNOON.
WIDESPREAD SEVERE THUNDERSTORMS ARE NOT EXPECTED DUE TO MARGINAL
INSTABILITY AND RATHER WEAK WIND FIELDS...THOUGH CANNOT RULE OUT
LARGE HAIL WITH WBZ HEIGHTS AROUND 9 KFT.
THUNDERSTORMS WILL DIMINISH SUNDAY NIGHT AND MONDAY AS THE SHORT
WAVE LIFTS NORTH AND AN UPPER RIDGE STARTS TO BUILD IN. DRY
WEATHER IS EXPECTED BY MONDAY EVENING AS THE UPPER RIDGE BECOMES
ESTABLISHED AND A CYCLONIC FLOW DEVELOPS IN LOWER LEVELS.
TEMPERATURES WILL STAY MORE THAN 20 DEGREES ABOVE NORMAL THROUGH
THE PERIOD. HIGHS IN THE MID AND UPPER 70S ON SUNDAY AND
AROUND 80 ON MONDAY WILL BE FLIRTING WITH RECORD HIGHS AT OUR 3
CLIMATE SITES AT CINCINNATI...COLUMBUS AND DAYTON.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
HIGHLY AMPLIFIED MID/UPPER LEVEL FLOW PATTERN WITH A TROF OVER THE
WEST AND A LARGE RIDGE OVER THE EASTERN UNITED STATES. THIS RIDGE
WILL PROVIDE DRY WEATHER AND MUCH ABOVE NORMAL TEMPERATURES. FOR
TUESDAY HAVE FCST HIGHS FROM NEAR 80 NORTH TO THE LOWER 80S SOUTH.
RECORD HIGHS WILL BE IN JEOPARDY OF FALLING. TUESDAYS RECORD HIGHS
ARE CVG 82, DAY 79 AND CMH 78.
THE STRONG UPPER LEVEL RIDGE TO SLIDE OFF TO THE EAST COAST ON
WEDNESDAY WITH THE UPPER TROF MOVING INTO THE NATIONS MID SECTION.
GIVEN THE HIGH DEGREE OF AMPLIFICATION...PREFER THE SLOWER ECMWF
SOLN...KEEPING THE REGION DRY ON WED. EXPECT HIGHS TO RANGE FROM THE
UPPER 70S NORTH TO 80 SOUTH. AGAIN RECORDS WILL BE IN JEOPARDY WITH
WEDNESDAY RECORDS STANDING AT 79 FOR CVG, 78 FOR DAY AND 80 AT
CMH.
UPPER LEVEL LOW TO PUSH SLOWLY EAST INTO THE OHIO VALLEY
THURSDAY/FRIDAY. NUMERICAL MODELS GENERALLY SIMILAR WITH THE CENTER
OF THE LOW CLOSE TO CVG BY FRIDAY EVENING. WILL INTRODUCE LOW POPS
INTO THE SW LATE WED NIGHT AND THEN SPREAD THIS CHC NE ACRS THE FA
THURSDAY. WL BUMP POPS UP TO HIGH CHC LATE THURSDAY NIGHT/EARLY
FRIDAY WITH THE APPROACH OF SFC FRONTAL BOUNDARY. UNDER CONTD
INFLUENCE OF THE UPPER LOW...WL CONTINUE LOW POPS INTO NEXT WEEKEND.
HAVE TRENDED THURSDAYS AND FRIDAYS HIGHS A LTL ABOVE GUID BUT OPTED
TO GO COOLER ON SATURDAY FOLLOWING ECMWF SOLN WHICH BRINGS IN COLDER
AIR.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
REGION CONTINUES TO BE LOCATED ON THE BACK SIDE OF A MID LVL RIDGE
AXIS WHICH STRETCHES FROM THE GULF COAST NE INTO NEW ENGLAND.
WEATHER PATTERN IS COMPARABLE TO A LATE SPRING OR EARLY SUMMER
REGIME WITH EMBEDDED DISTURBANCES MOVING NE ON THE BACK SIDE OF
THE RIDGE AXIS AND CONSEQUENTLY TRIGGERING AREAS OF SHOWERS AND
STORMS IN THE MOIST...UNSTABLE AIR. MODELS USUALLY HAVE A HARD
TIME ON PLACEMENT...TIMING AND COVERAGE OF STORMS AND TONIGHT INTO
SUNDAY WILL BE NO DIFFERENT. HAVE OPTED TO TRY AND PINPOINT THE
VERY SHORT TERM AND BROAD BRUSH THE LONG TERM BEYOND 6 HOURS GIVEN
LOW CONFIDENCE. WITH THAT SAID...MOSAIC RADAR WAS SHOWING A BROKEN
LINE OF SHOWERS AND THUNDERSTORMS STRETCHING FROM SRN INDIANA INTO
NORTHERN KENTUCKY NEAR KSDF. HRRR MODEL AND RADAR MOVEMENT SUGGEST
THAT THIS ACTIVITY SHOULD MAKE IT NEAR KCVG AND KLUK BETWEEN 02Z
AND 03Z AS LONG AS IT DOES NOT FALL APART. HAVE PLACED A VCTS AND
CB IN KCVG AND KLUK IN REGARDS TO THIS POTENTIAL ACTIVITY.
FOR THE REMAINDER OF THE NIGHT...ALL EYES FOCUS ON A MAIN
DISTURBANCE LOCATED TO THE WEST OVER MISSOURI/ILLINOIS. THIS
FEATURE IS FORECAST TO SLOWLY ROTATE ENE THROUGH THE AREA ON
SUNDAY. POTENTIAL EXITS FOR SHOWERS WITH EMBEDDED THUNDER AS IT
MOVES THROUGH. FOR NOW...HAVE PLACED VFR SHOWERS IN THE TAFS IN
CONJUNCTION WITH THE BEST FORCING...KNOWING THAT LOCAL MVFR OR
EVEN ISOLATED IFR WILL BE POSSIBLE IN HEAVIER SHOWERS AND EMBEDDED
STORMS. GIVEN LOW CONFIDENCE ON THUNDER COVERAGE...VCTS/CB HAVE
BEEN LEFT OUT ATTM.
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY EVENING AND AGAIN ON
THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO
NEAR TERM...CONIGLIO
SHORT TERM...CONIGLIO
LONG TERM...AR
AVIATION...HICKMAN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1239 PM CDT SAT MAR 17 2012
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
UPDATED FIRE WEATHER WATCH TO RED FLAG WARNING ACROSS CENTRAL
SOUTH DAKOTA FOR SUNDAY AFTERNOON.
STRATUS CLOUDS ARE QUICKLY FILLING IN AND EXPANDING ACROSS THE
EASTERN CWA AS LOW LEVEL MOISTURE CONTINUES TO STREAM NORTHWARD.
SEVERAL CHANGES NEEDED TO WEATHER ELEMENTS THIS MORNING TO ACCOUNT
FOR THIS. INCREASED SKY COVER QUITE A BIT THROUGH THE MORNING AND
INTO THE AFTERNOON. RUC SOUNDINGS ON BUFKIT PICKING UP ON THESE
CLOUDS AND WOULD SUGGEST STRATUS STICKING AROUND INTO THE
AFTERNOON BEFORE STRATOCU-ING OUT. THIS ALSO THROWS A WRENCH INTO
THE TEMP RISE THIS MORNING SO ADJUSTED HOURLY READINGS. DID NOT
MESS WITH HIGHS AT THIS TIME SINCE BY MID TO LATE AFTERNOON STILL
EXPECTING CLOUDS TO BREAK UP AND TEMPS TO RISE. WILL MONITOR THIS
THOUGH. DEWPOINTS RISING THROUGH THE 50S ACROSS THE EASTERN CWA.
FOG STILL HANGING AROUND IN SPOTS AS WELL SO EXTENDED MENTION OF
THIS FOR A COUPLE MORE HOURS. FARTHER WEST...PLENTY OF SUNSHINE
ALL DAY WITH VERY LOW RH VALUES IN THE AFTERNOON LEADING TO HIGH
TO VERY HIGH FIRE DANGER. STILL APPEARS WINDS WILL NOT BE STRONG
ENOUGH TO WARRANT AND FIRE HEADLINES FOR THIS AFTERNOON.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...THROUGH MONDAY
PRESSURE GRADIENT CONTINUES TO RELAX...WHICH WILL RESULT IN
LIGHTER WINDS TODAY...LESS EFFICIENT MIXING...AND HIGHER HUMIDITY.
A POCKET OF HIGHER MOISTURE AIR SITS ACROSS THE EAST AND WILL
EXPAND WESTWARDS WITH SOUTH/SOUTHEAST WINDS TODAY...SO
TEMPERATURES WILL BE SOMEWHAT LESS EXTREME DESPITE SIMILAR
TEMPERATURES ALOFT. AS UPPER TROF CONTINUES TO SLOWLY PUSH
EAST...WILL SEE LEE CYCLOGENISIS ACROSS WESTERN SOUTH
DAKOTA...INCREASING THE GRADIENT OVERNIGHT ALONG WITH WEAK LOW
LEVEL JET FORMATION. A TIGHT HUMIDITY GRADIENT WILL CONTINUE
ACROSS THE AREA OVERNIGHT AS WELL. AS THE SYSTEM SHIFTS EAST
SUNDAY...PRESSURE GRADIENT INTENSIFIES ALONG WITH A 50-60KT H85
JET MAX. HAVE ISSUED A FIRE WEATHER WATCH GIVEN DEEP MIXING WHICH
WILL HELP MIX OUT SHALLOW MOISTURE IN THE WEST. THERE IS PLENTY OF
UNCERTAINTY OVER HOW EFFICIENTLY THIS MOISTURE WILL MIX OUT IN THE
EAST. WINDS WILL STAY UP OVERNIGHT SUNDAY/EARLY MONDAY AS WELL.
AS FOR PRECIPITATION CHANCES...WITH WARM LOW LEVEL AIRMASS...WILL
SEE STEEP LAPSE RATES ALOFT THROUGH MOST OF THE PERIOD. MOISTURE
IS RELATIVELY SHALLOW AND DYNAMICS ARE LACKING FOR MOST OF THE
PERIOD TO WARRANT MENTION OF THUNDER...UNTIL LATE SUNDAY. A WEAK
WAVE IN SOUTHWEST FLOW COULD SUPPORT HIGH BASED ALTO CUMULUS. MORE
WIDESPREAD CONVECTION IS POSSIBLE WITH A STRONGER WAVE LIFTING
NORTH WITH A SLOW MOVING NORTH/SOUTH ORIENTED COLD FRONT PROVIDING
THE FOCUS FOR THUNDERSTORMS.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
THE THEME DURING THE EXTENDED IS COOL DOWN. MONDAY NIGHT...A COLD
FRONT IS WORKING ACROSS THE EASTERN HALF OF FORECAST ZONES...WITH
NOTABLY COOLER/DRIER AIR ADVECTING IN BEHIND FOR TUESDAY AND
WEDNESDAY. FOLLOWED THE PREFERRED ECMWF SOLUTION FOR HANDLING THE
CLOSED UPPER LOW ENERGY OVER THE LOWER/MID-MISSISSIPPI VALLEY
REGION...WHICH IS TO PROPAGATE THE LOW EASTWARD AWAY FROM THIS
REGION AS THE WEEK WEARS ON...VERSUS THE GFS SOLUTION THAT STILL
TRIES TO DRAW THE CLOSED UPPER LOW NORTHWARD TOWARD IOWA.
THE ECMWF ACTUALLY DOES TRY TO BRING A BIT OF RETURN FLOW WARMTH
BACK INTO THE REGION ON THURSDAY BEFORE A LOW PRESSURE SYSTEM IN
THE FAST WESTERLY FLOW ACROSS SOUTHERN CANADA DRAGS A COLD FRONT
ACROSS THE CWA...MAINLY THURSDAY NIGHT...RENDERING FRIDAY ALSO A
BIT COOLER. NOW...BY COOLER AND DRIER...NOT SPEAKING OF HIGHS IN
THE 30S TO LOW 40S. RATHER...HIGH TEMPERATURES WILL LIKELY BE MORE
LIKE 50S FOR TUESDAY AND WEDNESDAY /STILL ABOVE NORMAL/...A BIT
WARMER FOR THURSDAY...AND THEN LIKELY BACK DOWN INTO THE 50S FOR
FRIDAY.
PRECIPITATION CHANCES ARE TRENDING DOWNWARD MONDAY NIGHT AND ALL
BUT GONE ON TUESDAY...WITH DRY FORECAST CONDITIONS PERSISTING
THROUGH THURSDAY. THERE MAY BE ENOUGH LIFT/FORCING AND MOISTURE
AROUND THURSDAY NIGHT...ATTACHED TO THE COLD FROPA...TO SEE A FEW
SHOWERS DEVELOP...MAINLY OVER NERN SODAK OVER INTO MN.
THEN...THE FORECAST TIPS BACK OVER TO A DRY ONE ON FRIDAY.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE STILL EXPECTED AT MBG AND PIR THROUGH TODAY
AND TONIGHT. THERE IS SOME POTENTIAL FOR STRATUS EARLY SUNDAY
MORNING IN THE WEST...ADVECTING IN ON SE SFC WINDS...BUT STILL TOO
UNCERTAIN TO ADD TO THE TAFS. LOW CLOUDS AND FOG WILL BREAK UP AND
THEN FILL BACK IN THROUGH THE DAY WITH IFR CIGS LIFTING TO MVFR
CIGS...BUT LIKELY NOT DISSIPATING COMPLETELY. LATER TONIGHT AFTER
SUNSET...BKN COVERAGE OF LOW CIGS AND/OR FOG IS EXPECTED TO RE-
ESTABLISH OVER CENTRAL AND EASTERN SOUTH DAKOTA. WINDS WILL
INCREASE ON SUNDAY OUT OF THE SOUTH TO SOUTHEAST.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TO 10 PM CDT /9 PM
MDT/ SUNDAY FOR LOWER BAD RIVER-MISSOURI COTEAU-UPPER
CHEYENNE-UPPER MISSOURI COTEAU.
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR UPPER JAMES RIVER.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...TMT
LONG TERM...DORN
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1125 AM CDT SAT MAR 17 2012
.UPDATE...REST OF TODAY
UPDATED FIRE WEATHER WATCH TO RED FLAG WARNING ACROSS CENTRAL
SOUTH DAKOTA FOR SUNDAY AFTERNOON.
STRATUS CLOUDS ARE QUICKLY FILLING IN AND EXPANDING ACROSS THE
EASTERN CWA AS LOW LEVEL MOISTURE CONTINUES TO STREAM NORTHWARD.
SEVERAL CHANGES NEEDED TO WEATHER ELEMENTS THIS MORNING TO ACCOUNT
FOR THIS. INCREASED SKY COVER QUITE A BIT THROUGH THE MORNING AND
INTO THE AFTERNOON. RUC SOUNDINGS ON BUFKIT PICKING UP ON THESE
CLOUDS AND WOULD SUGGEST STRATUS STICKING AROUND INTO THE
AFTERNOON BEFORE STRATOCU-ING OUT. THIS ALSO THROWS A WRENCH INTO
THE TEMP RISE THIS MORNING SO ADJUSTED HOURLY READINGS. DID NOT
MESS WITH HIGHS AT THIS TIME SINCE BY MID TO LATE AFTERNOON STILL
EXPECTING CLOUDS TO BREAK UP AND TEMPS TO RISE. WILL MONITOR THIS
THOUGH. DEWPOINTS RISING THROUGH THE 50S ACROSS THE EASTERN CWA.
FOG STILL HANGING AROUND IN SPOTS AS WELL SO EXTENDED MENTION OF
THIS FOR A COUPLE MORE HOURS. FARTHER WEST...PLENTY OF SUNSHINE
ALL DAY WITH VERY LOW RH VALUES IN THE AFTERNOON LEADING TO HIGH
TO VERY HIGH FIRE DANGER. STILL APPEARS WINDS WILL NOT BE STRONG
ENOUGH TO WARRANT AND FIRE HEADLINES FOR THIS AFTERNOON.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...THROUGH MONDAY
PRESSURE GRADIENT CONTINUES TO RELAX...WHICH WILL RESULT IN
LIGHTER WINDS TODAY...LESS EFFICIENT MIXING...AND HIGHER HUMIDITY.
A POCKET OF HIGHER MOISTURE AIR SITS ACROSS THE EAST AND WILL
EXPAND WESTWARDS WITH SOUTH/SOUTHEAST WINDS TODAY...SO
TEMPERATURES WILL BE SOMEWHAT LESS EXTREME DESPITE SIMILAR
TEMPERATURES ALOFT. AS UPPER TROF CONTINUES TO SLOWLY PUSH
EAST...WILL SEE LEE CYCLOGENISIS ACROSS WESTERN SOUTH
DAKOTA...INCREASING THE GRADIENT OVERNIGHT ALONG WITH WEAK LOW
LEVEL JET FORMATION. A TIGHT HUMIDITY GRADIENT WILL CONTINUE
ACROSS THE AREA OVERNIGHT AS WELL. AS THE SYSTEM SHIFTS EAST
SUNDAY...PRESSURE GRADIENT INTENSIFIES ALONG WITH A 50-60KT H85
JET MAX. HAVE ISSUED A FIRE WEATHER WATCH GIVEN DEEP MIXING WHICH
WILL HELP MIX OUT SHALLOW MOISTURE IN THE WEST. THERE IS PLENTY OF
UNCERTAINTY OVER HOW EFFICIENTLY THIS MOISTURE WILL MIX OUT IN THE
EAST. WINDS WILL STAY UP OVERNIGHT SUNDAY/EARLY MONDAY AS WELL.
AS FOR PRECIPITATION CHANCES...WITH WARM LOW LEVEL AIRMASS...WILL
SEE STEEP LAPSE RATES ALOFT THROUGH MOST OF THE PERIOD. MOISTURE
IS RELATIVELY SHALLOW AND DYNAMICS ARE LACKING FOR MOST OF THE
PERIOD TO WARRANT MENTION OF THUNDER...UNTIL LATE SUNDAY. A WEAK
WAVE IN SOUTHWEST FLOW COULD SUPPORT HIGH BASED ALTO CUMULUS. MORE
WIDESPREAD CONVECTION IS POSSIBLE WITH A STRONGER WAVE LIFTING
NORTH WITH A SLOW MOVING NORTH/SOUTH ORIENTED COLD FRONT PROVIDING
THE FOCUS FOR THUNDERSTORMS.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
THE THEME DURING THE EXTENDED IS COOL DOWN. MONDAY NIGHT...A COLD
FRONT IS WORKING ACROSS THE EASTERN HALF OF FORECAST ZONES...WITH
NOTABLY COOLER/DRIER AIR ADVECTING IN BEHIND FOR TUESDAY AND
WEDNESDAY. FOLLOWED THE PREFERRED ECMWF SOLUTION FOR HANDLING THE
CLOSED UPPER LOW ENERGY OVER THE LOWER/MID-MISSISSIPPI VALLEY
REGION...WHICH IS TO PROPAGATE THE LOW EASTWARD AWAY FROM THIS
REGION AS THE WEEK WEARS ON...VERSUS THE GFS SOLUTION THAT STILL
TRIES TO DRAW THE CLOSED UPPER LOW NORTHWARD TOWARD IOWA.
THE ECMWF ACTUALLY DOES TRY TO BRING A BIT OF RETURN FLOW WARMTH
BACK INTO THE REGION ON THURSDAY BEFORE A LOW PRESSURE SYSTEM IN
THE FAST WESTERLY FLOW ACROSS SOUTHERN CANADA DRAGS A COLD FRONT
ACROSS THE CWA...MAINLY THURSDAY NIGHT...RENDERING FRIDAY ALSO A
BIT COOLER. NOW...BY COOLER AND DRIER...NOT SPEAKING OF HIGHS IN
THE 30S TO LOW 40S. RATHER...HIGH TEMPERATURES WILL LIKELY BE MORE
LIKE 50S FOR TUESDAY AND WEDNESDAY /STILL ABOVE NORMAL/...A BIT
WARMER FOR THURSDAY...AND THEN LIKELY BACK DOWN INTO THE 50S FOR
FRIDAY.
PRECIPITATION CHANCES ARE TRENDING DOWNWARD MONDAY NIGHT AND ALL
BUT GONE ON TUESDAY...WITH DRY FORECAST CONDITIONS PERSISTING
THROUGH THURSDAY. THERE MAY BE ENOUGH LIFT/FORCING AND MOISTURE
AROUND THURSDAY NIGHT...ATTACHED TO THE COLD FROPA...TO SEE A FEW
SHOWERS DEVELOP...MAINLY OVER NERN SODAK OVER INTO MN.
THEN...THE FORECAST TIPS BACK OVER TO A DRY ONE ON FRIDAY.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE STILL EXPECTED AT MBG AND PIR THROUGH TODAY
AND TONIGHT. LOW LEVEL MOISTURE HAS BEEN INCREASING EARLY THIS
MORNING AND COULD BRING SOME LIGHT FOG AND LOW STRATUS TO PARTS OF
NORTHEAST SOUTH DAKOTA THIS MORNING INCLUDING AT ABR AND ATY...BUT
ESPECIALLY AT ATY. OTHERWISE...ANY LOW CLOUDS AND FOG WILL BREAK UP
THROUGH THE LATE MORNING AND EARLY AFTERNOON WITH IFR CIGS LIFTING
TO MVFR CIGS...BUT PROLLY NOT DISSIPATING COMPLETELY. LATER
TONIGHT AFTER SUNSET...SCT-BKN COVERAGE OF LOW CIGS AND/OR FOG IS
EXPECTED TO RE-ESTABLISH OVER CENTRAL AND EASTERN SOUTH DAKOTA.
WILL NEED TO MONITOR AND ADJUST FOG/STRATUS COVERAGE LATER TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TO 10 PM CDT /9 PM
MDT/ SUNDAY FOR LOWER BAD RIVER-MISSOURI COTEAU-UPPER
CHEYENNE-UPPER MISSOURI COTEAU.
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR UPPER JAMES RIVER.
MN...NONE.
&&
$$
UPDATE...TMT
SHORT TERM...CONNELLY
LONG TERM...DORN
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
324 PM CDT SAT MAR 17 2012
.SHORT TERM...TONIGHT AND SUNDAY...FORECAST CONFIDENCE MEDIUM
MAIN STORY CONTINUES TO BE THE UNSEASONABLE HEAT ACROSS SOUTHERN
WI. THE WARM PUMP JUST KEEPS ON PUMPING WITH MORE RECORD WARMTH ON
TAP FOR SUNDAY. RECORD HIGH MINIMUMS WILL BE SHATTERED TONIGHT
WITH MORE RECORDS SHATTERED ON SUNDAY. ON THE PRECIP END OF
THINGS...PER WATER VAPOR RUC COMBO...WATCHING A COUPLE OF WAVES
RIDING NORTHEAST FROM MISSOURI. APPEARS TO BE A DOUBLE VORT
STRUCTURE WITH ONE VORT IN SC MO AND THE OTHER IN THE NW. THIS
MORE NW VORT IS OF GREATEST CONCERN AS IT HAS THE POTENTIAL TO
REPEAT THE CONVECTION IN A SIMILAR FASHION TO WHAT TRANSPIRED
SATURDAY MORNING. SEEING EVIDENCE OF SOME INCREASED 850 MOISTURE
ADVECTION AROUND 12Z SUNDAY WITH DEW POINTS INCREASING A BIT ON
THE EASTERN EDGE OF THE 850 LOW LEVEL JET AXIS. WEAK 700 WARM
ADVECTION NOTED WITH SOME FRONTOGENETICAL FORCING. PER
MODELS...BELIEVE GREATER COVERAGE AND POTENTIAL WILL BE TO OUR
SOUTH WITH THE STRONGER SOUTHERN VORT. ONCE ANY OF THIS CONVECTION
GETS OUT OF THE WAY...SHAPING UP TO BE ANOTHER WARM DAY. 925 TEMPS
SUPPORT TEMPS SIMILAR TO SATURDAY WITH A FEW READINGS EXCEEDING 80
DEGREES.
SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM
UPPER RIDGING WILL BE OCCURRING FROM SUN AFT INTO SUN NT AS STRONG
LOW PRESSURE AND THE UPPER WAVE OVER THE NRN HIGH PLAINS LIFTS NWD
INTO CANADA. MEANWHILE THE SRN PORTION OF THE LARGE UPPER TROUGH
OVER THE WEST WILL SLOWLY PROGRESS INTO THE SRN HIGH PLAINS AND TX
INTO TUE. THE WARM CONVEYOR BELT AHEAD OF THE UPPER TROUGH WILL
EXTEND WELL NWD WITH THE ERN PERIPHERY AFFECTING THE WEST HALF OF
WI FOR MON-TUE. THE WEAKENING COLD FRONT OVER THE PLAINS WILL STAY
TO THE WEST DURING THIS PERIOD. THUS POPS INCREASE FROM EAST TO
WEST ACROSS THE CWA WITH BEST CHANCES FOR PCPN ON MON. THE WARM
CONVEYOR BELT MAY ACTUALLY SHIFT SLIGHTLY WWD FOR MON NT AND TUE
SO LESSER POPS ARE FORECAST. KEPT TEMPS A LITTLE COOLER FOR MON
DUE TO MORE CLOUDS AND PCPN CHANCES BUT INCREASED THEM AGAIN FOR
TUE WITH LESS CLOUDS/PCPN CHANCES.
.LONG TERM...WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE MEDIUM
THE LARGE CLOSED LOW OVER TX FOR TUE/TUE NT IS THEN DEPICTED BY
THE EXTENDED MODELS TO SLOWLY EJECT NEWD...REACHING THE OHIO RIVER
VALLEY BY FRI AND THE EAST COAST LATER ON SAT. THE WEAK COLD FRONT
WILL SLOWLY PROGRESS ACROSS SRN WI WED-THU WITH THE WARM CONVEYOR
BELT OVERHEAD. DECENT CHANCES OF SHOWERS AND TSTORMS IS FORECAST
WITH PCPN CHANCES DECREASING FOR THE END OF THE WEEK AS THE SYSTEM
MOVES AWAY. A CANADIAN COLD FRONT WILL THEN ARRIVE FRI NT IN
RESPONSE TO CYCLOGENESIS MOVING EWD ACROSS SRN CANADA. SOME
DIFFERENCES ON MODELS ON THE STRENGTH OF THE COOL AIR BUT BEST ESTIMATE
AT THIS TIME IS FOR HIGHS IN THE 50S ON SAT WHICH IS STILL ABOVE NORMAL.
&&
.AVIATION/00Z TAFS/...VFR THIS PERIOD WITH BROAD SOUTHERLY FLOW
CONTINUING BETWEEN HIGH PRESSURE ON THE EAST COAST AND LOW PRESSURE
SITUATED OVER THE NORTHERN PLAINS. CU FIELD WILL DISSIPATE WITH THE
LOSS OF DAYTIME HEATING. LIGHT FOG POTENTIAL LATER TONIGHT AND EARLY
SUNDAY BUT WILL NOT LATCH ONTO THE DENSE FOG PLAYED OUT BY MOS WITH
MAIN SYNOPTIC WARM FRONT WELL NORTH. POPS ARE IN THE SINGLE DIGITS.
WILL HAVE TO WATCH ANOTHER WAVE PROGGD TO TRACK SOUTH OF WI LATER
TONIGHT AND SUNDAY MORNING. GFS MORE GENEROUS WITH QPF BUT GUID POPS
ARE QUITE LOW. IF STORMS DEVELOP EXPECTING COVERAGE TO BE ISOLATED
AT BEST...WILL LEAVE OUT MENTION FOR NOW UNTIL CONVECTIVE TRENDS IN
TERMS OF TIMING AND COVERAGE BECOME MORE CLEAR.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/SUNDAY AND AVIATION/MARINE...COLLAR
SUNDAY NIGHT THROUGH SATURDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1231 PM CDT SAT MAR 17 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
310 AM CDT SAT MAR 17 2012
MAIN FORECAST CONCERNS ARE ON ANY CHANCES FOR PRECIPITATION THROUGH
SUNDAY NIGHT...WINDS AND THE UNPRECEDENTED WARMTH.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT
ANALYSIS SHOWED DEEP TROUGHING JUST OFF THE CALIFORNIA COAST WHILE
BROAD RIDGING WAS BUILDING DOWNSTREAM OVER THE EASTERN TWO THIRDS
OF THE U.S.. RIDGE AXIS SITS OVER THE GREAT LAKES...PLACING THE
FORECAST AREA UNDER SOUTHWEST FLOW. WITHIN THIS SOUTHWEST FLOW...A
WEAK SHORTWAVE COMBINED WITH A WARM FRONTAL BOUNDARY AND
INCREASING LOW LEVEL JET TO PRODUCE A CLUSTER OF STRONG TO SEVERE
SHOWERS AND THUNDERSTORMS LAST EVENING OVER CENTRAL WISCONSIN.
THESE HAVE SINCE LIFTED INTO UPPER MICHIGAN THANKS TO THE
SHORTWAVE MOVING NORTHEAST AND A 30-40 KT SOUTHWEST JET AT 850MB.
WITHIN THIS SOUTHWEST FLOW...THE ONLY SHORTWAVES OF NOTE ARE WEAK
ONES IN NEBRASKA...AND THESE ARE NOT PRODUCING MUCH CLOUDS AT ALL.
WITH THE FORECAST AREA UNDER THAT STRONG SOUTHWEST JET AND A
RELATIVELY TIGHT PRESSURE GRADIENT AT THE SURFACE AHEAD OF A
TROUGH IN THE DAKOTAS... TEMPERATURES HAVE STRUGGLED TO FALL.
READINGS ARE ONLY IN THE 60S. DEWPOINTS ARE ALSO STAYING UP IN THE
MID TO UPPER 50S. AIRMASS IS ALSO SEMI-CAPPED AND DRY...LOOKING AT
THE 00Z DVN SOUNDING. GOING FARTHER SOUTHWEST TO OAX AND IT DRIES
OUT EVEN MORE. DESPITE THE DRIER AIR...THERE IS ENOUGH INSTABILITY
WHEN LIFTED FROM 800MB /APPROX 700 J/KG/ TO PRODUCE PRECIPITATION.
A ZONE OF 800MB SPEED CONVERGENCE IN SOUTHWEST WISCONSIN AND
NORTHWEST ILLINOIS HAS PRODUCED SOME SHOWERS DOWN THERE.
TODAY THROUGH SUNDAY NIGHT...UPPER TROUGHING APPROACHING THE WEST
COAST OF THE U.S. RIGHT NOW IS PROGGED BY ALL MODELS TO MOVE INTO
THE ROCKIES BY 12Z MONDAY. A FAIRLY DEEP LOW PRESSURE SYSTEM ENDS UP
DEVELOPING OVER EASTERN MONTANA AS THIS TROUGH MOVES EAST...ALLOWING
FOR STRONG SOUTHERLY FLOW TO PERSIST DOWNSTREAM INTO OUR FORECAST
AREA. A COUPLE OF IMPACTS FROM THIS STRONG SOUTHERLY FLOW INCLUDE:
1. HELPING TO MAINTAIN THE UNSEASONABLY HIGH DEWPOINTS...WHICH COULD
EXCEED 60F AT TIMES BETWEEN 15-18Z BEFORE DROPPING DUE TO MIXING.
2. MAINTAIN THE UNSEASONABLY WARM 925 AND 850MB TEMPS...WHICH ARE
PROGGED TO STAY BETWEEN 16-20C AND 12-14C RESPECTIVELY. THESE
READINGS ARE VERY SIMILAR TO WHAT WAS SEEN FRIDAY...SO HIGH
TEMPERATURES BOTH TODAY AND SUNDAY ARE LIKELY TO BE SIMILAR. SOME
HINTS FROM MET GUIDANCE WHICH DID WELL YESTERDAY THAT SITES SUCH AS
BOSCOBEL COULD HIT THE MID 80S. GENERALLY FOLLOWED THIS.
3. A LOT OF GUSTY WINDS THROUGHOUT. APPEARS THAT WHEN LOOKING AT
SOUNDINGS...MIXING DEPTHS AT MOST APPROACH 850MB. MOMENTUM TRANSFER
FROM THIS LEVEL KEEPS WINDS BELOW ADVISORY CRITERIA...EVEN AT RST.
4. RESULTING FROM ITEMS 1-3 ABOVE...LOW TEMPERATURES ARE GOING TO
STAY VERY WARM FOR THIS TIME OF YEAR...LIKELY STRUGGLING TO GET MUCH
BELOW 60.
REGARDING PRECIPITATION...TRIGGERS ARE VERY HARD TO FIND THROUGH
SUNDAY NIGHT. IN ADDITION...THE AIRMASS LOOKS A LITTLE MORE CAPPED
PER RUC/GFS SOUNDINGS. WE DO HAVE THE WEAK SHORTWAVES IN NEBRASKA
COMING ACROSS THE FORECAST AREA AT 18Z TODAY...BUT THERE IS NO
SURFACE CONVERGENT FEATURE LIKE YESTERDAY WITH THE WARM FRONT. IN
FACT...NO SURFACE CONVERGENT FEATURES ARE PRESENT THROUGH SUNDAY
NIGHT. AFTER 06Z SUNDAY NIGHT...THERE ARE INDICATIONS OF A
SHORTWAVE COMING ACROSS SOUTHEAST MINNESOTA...AS WELL AS
ISENTROPIC LIFT ON THE 305-310 K SURFACES. THE 17.00Z GFS/CANADIAN
BOTH HINT AT POTENTIAL FOR SOME CONVECTION IN THIS AREA...SO
INCLUDED SOME 20 PERCENT CHANCES FOR NOW...GIVEN NAM/UKMET/ECMWF
DRY. FOR THE REST OF THE PERIOD...ALL MODELS ARE PRETTY MUCH DRY
THROUGH SUNDAY WHICH SEEMS REASONABLE.
MONDAY AND MONDAY NIGHT...THE UPPER TROUGHING OVER THE ROCKIES IS
FORECAST TO INCH EASTWARD...WITH ITS AXIS FROM EASTERN MONTANA INTO
NEW MEXICO AT 12Z TUESDAY. ALTHOUGH THIS TROUGH IS FAR AWAY FROM THE
AREA...WE WILL SEE 10-30 METER 500MB HEIGHT FALLS EACH 12 HOUR
PERIOD OVER THE FORECAST AREA...HIGHEST WEST. THESE HEIGHT FALLS
COMBINED WITH STRONG MOISTURE TRANSPORT ON A SOUTHERLY 40-60 KT
850MB JET WILL YIELD INCREASING PRECIPITATION CHANCES...ESPECIALLY
AGAIN OVER THE WEST. PRECIPITABLE WATER VALUES CLIMB TO 1-1.4 INCHES
WHICH WOULD SUPPORT SOME DECENT PRECIPITATION TOO. CAPE VALUES ARE
RESTRICTED SOMEWHAT DUE TO CLOUD COVER...PERHAPS UP TO 500 J/KG OF
VERY THIN MUCAPE. THIS SHOULD LIMIT THUNDER COVERAGE TOO. DESPITE
THE INCREASED CLOUD COVER AND PRECIPITATION...STILL ANTICIPATING
TEMPERATURES TO RISE INTO THE 70S ON MONDAY...WARMEST EAST WHERE
SOME SUN COULD OCCUR. LOWS STAY UP TOO MONDAY NIGHT WITH THE SURFACE
COLD FRONT STILL WAY OFF TO THE WEST IN THE EASTERN DAKOTAS.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
310 AM CDT SAT MAR 17 2012
LONG TERM FORECAST IS BECOMING MORE UNCERTAIN...PRIMARILY BECAUSE
MODELS ARE STRUGGLING ON HOW TO HANDLE THE WESTERN U.S. TROUGH FROM
MONDAY NIGHT. 17.00Z ECMWF/GFS/CANADIAN AND MOST GFS ENSEMBLES ALL
SUGGEST THE TROUGH WILL CUT-OFF AS IT CROSSES THE PLAINS TUESDAY AND
WEDNESDAY...BUT EXACTLY WHEN AND THEN HOW TO HANDLE THIS UPPER LOW
VARIES AMONG EVERY MODEL. THERE STILL REMAINS A FEW GFS ENSEMBLES
AND THE 17.00Z UKMET THAT SUGGEST THE TROUGH STAYS TOGETHER...
FOLLOWING THE 16.12Z ECMWF IDEA. HOWEVER...OVER THE LAST COUPLE DAYS
OF MODEL RUNS...THESE SEEM TO BE AN OUTLIER. THEREFORE PREFERENCE IS
TO FOLLOW THE MAJORITY 17.00Z GUIDANCE. AS THE UPPER TROUGH
APPROACHES THE FORECAST AREA TUESDAY INTO WEDNESDAY...THE MOISTURE
STREAM REFERENCED IN THE MONDAY/MONDAY NIGHT DISCUSSION WILL FULLY
SHIFT OVERHEAD. SEEMS LIKE TUESDAY NIGHT IS THE BEST PERIOD FOR THE
ENTIRE FORECAST AREA TO SEE RAIN. MODEL GUIDANCE CONSENSUS OF 60-70
PERCENT CHANCES ARE REASONABLE...BUT MAY NEED TO BE RAISED MORE IF
THIS TIME PERIOD REMAINS CONSISTENT FOR PRECIPITATION. AFTER
WEDNESDAY...ATTENTION TURNS TO THE SOUTHERN END OF THE SPLITTING
UPPER TROUGH WHICH TURNS INTO AN UPPER LOW. SOME MODELS SUGGEST THE
UPPER LOW COULD LIFT TOWARDS THE AREA ON FRIDAY. IF SO...THEN SOME
SHOWERS COULD MOVE IN. FOR NOW...HAVE LOWER 20-40 PERCENT CHANCES
FOR WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...ACCOUNTING FOR THE
DIMINISHING MOISTURE STREAM AND THE APPROACH OF THE UPPER LOW.
REGARDING THUNDER...REDUCED THESE PROBABILITIES TO 20 AND ONLY
DURING THE DAYTIME HOURS FOR TUESDAY THROUGH THURSDAY...GIVEN LESS
THAN 500 J/KG OF ONLY DAYTIME INSTABILITY SUGGESTED BY THE GFS.
TEMPERATURES THROUGHOUT MUCH OF THE LONG TERM PERIOD WILL STAY WELL
ABOVE NORMAL...UNTIL MAYBE FRIDAY NIGHT IF THE ECMWF IS RIGHT TRYING
TO SHOW SOME COLDER AIR COMING DOWN FROM CANADA. IN ANY
EVENT...850MB TEMPS DROP FROM 10-12C ON TUESDAY TO 6-8C BY 12Z
FRIDAY. A BLEND OF MODEL GUIDANCE SEEMED REASONABLE.
&&
.AVIATION...THIS AFTERNOON THROUGH SUNDAY
1231 PM CDT SAT MAR 17 2012
CONCERN THIS PERIOD IS THE INCREASING LOWER LEVEL MOISTURE/STRATUS
OVER THE TAF SITES. VIS IMAGERY/SFC OBS SHOWED A BROAD AREA OF SCT
TO OVC MVFR STRATUS ADVECTING NORTHEAST ACROSS IA AT MID-DAY...DUE
INTO KRST AROUND 20Z AND KLSE AROUND 22Z. LEADING EDGE OF THE CIGS
RISING WITH DIURNAL WARMING/MIXING TODAY TO NEAR MVFR/VFR THRESH-
HOLD. WITH DIURNAL COOLING TONIGHT BKN CIGS TO LOWER BACK INTO MVFR.
GIVEN THE EXTENT OF THE MOISTURE...THESE CLOUDS/CIGS LOOKING TO
PERSIST THRU AT LEAST SUN MORNING. WITH ALL THE LOW LEVEL MOISTURE
DIURNAL COOLING TONIGHT EXPECTED TO PRODUCE AREAS 3-5SM BR IN THE
08Z-15Z TIME-FRAME. PRESSURE GRADIENT OVER THE REGION WILL MAINTAIN
SOUTH WINDS 10-20KTS G25-30KT DURING THE LATE MORNINGS/AFTERNOONS...
WITH THE STRONGER/GUSTIER WINDS AT THE HIGHER ELEVATION OPEN COUNTRY
SITES LIKE KRST/KAUM/KTOB.
&&
.CLIMATE...TODAY THROUGH TUESDAY
310 AM CDT SAT MAR 17 2012
RECORD HIGHS AND RECORD WARM LOWS ARE POSSIBLE THROUGH TUESDAY...
ESPECIALLY THIS WEEKEND...AS AN UNSEASONABLY WARM AND MOIST AIR MASS
CONTINUES TO RESIDE ACROSS THE UPPER MIDWEST. TEMPERATURES SHOULD
BEGIN COOLING MON/TUE AS CLOUDS/ -SHRA INCREASE ACROSS THE AREA.
HOWEVER...RECORDS ON THOSE DAYS COMPARED TO FORECASTS STILL SUGGEST
SOME POTENTIAL TO BREAK THEM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
310 AM CDT SAT MAR 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS
CLIMATE......AJ/RRS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1229 PM CDT SAT MAR 17 2012
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY THROUGH SUNDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE WARM
FRONT LIFTING NORTHWARD OVER CENTRAL WISCONSIN EARLY THIS MORNING.
TEMPS ARE IN THE LOW TO MID 50S NORTH OF THE FRONT...AND IN THE MID
TO UPPER 60S SOUTH OF THE BOUNDARY. TEMPS ARE LOCALLY COOLER NEAR
LAKE MICHIGAN WITH SOME OF THAT MARINE AIR CURLING AROUND INTO
SHAWANO WHERE TEMPS ARE IN THE LOWER 40S WITHIN DENSE FOG. WIDELY
SCT SHOWERS AND THUNDERSTORMS THAT DEVELOPED OVER NORTH-CENTRAL
WISCONSIN HAVE BEEN WEAKENING AND WILL LIKELY EXIT THE AREA BY PRESS
TIME. ADDITIONAL ECHOES HAVE POPPED UP WITHIN THE INSTABILITY AXIS
OVER SW WISCONSIN AND NORTHWEST ILLINOIS...AND WILL ADD ISOLATED
SHOWERS AND THUNDERSTORMS NEARLY EVERYWHERE THROUGH MID-MORNING.
WITH VERY WARM AND UNSTABLE AIR MOVING INTO THE REGION TODAY...SMALL
PRECIP CHANCES ARE THE MAIN FORECAST CONCERN...FOLLOWED BY TEMPS AND
MARINE FOG.
TODAY...SURFACE WARM FRONT...WHICH SNAKES ACROSS WISCONSIN FROM NW
TO SE...WILL LIFT NORTH OF THE AREA THIS MORNING...WHICH WILL TURN
WINDS TO THE SOUTH EXCEPT ACROSS FAR NE WISCONSIN. SE WINDS
HERE...ENHANCED BY THE LAKE BREEZE THIS AFTERNOON...WILL KEEP WAVES
OF MARINE STRATUS AND FOG PROCEEDING INLAND AT TIMES.
OTHERWISE...850MB MOISTURE AND INSTABILITY AXIS WILL BE OVERHEAD
TODAY...WITH ML CAPES REACHING CLOSE TO 2500 J/KG WITH NO CIN THIS
AFTERNOON. TOUGH TO IDENTIFY A TRIGGER UPSTREAM THAT COULD TAP INTO
THIS INSTABILITY FOR THUNDERSTORM DEVELOPMENT...AND MAY JUST END UP
WITH BUBBLY CU...WHICH OCCURRED UPSTREAM TODAY. THERE ARE A COUPLE
WEAK IMPULSES UPSTREAM...OVER NW IOWA AND ANOTHER OVER WESTERN
NEBRASKA...BUT TOUGH TO SAY IF THEY WILL BE STRONG ENOUGH TO TRIGGER
CONVECTION. THE BEST THING TO LATCH ONTO IS THE SE FLOW OVER THE
DOOR...WHICH COULD GET ENHANCED BY THE LAKE BREEZE COMPONENT TO
CREATE CONVERGENCE OVER NE WISCONSIN. SYNOPTIC FLOW WILL BE OUT OF
THE SOUTH...NOT OUT OF THE SOUTHWEST OR WEST WHICH WOULD BE MORE
PREFERRED. STILL THOUGH...THAT MAGNITUDE OF CAPE CANNOT BE IGNORED
SO WILL KEEP AN ISOLATED MENTION OF SHOWERS AND THUNDERSTORMS OVER
NE WISCONSIN FOR THIS AFTERNOON. 925MB TEMPS 18C TO 20C CALL FOR
HIGHS IN THE UPPER 70S TO LOWER 80S.
TONIGHT...850MB MOISTURE AND INSTABILITY AXIS WILL REMAIN OVERHEAD.
LLJ WILL DEVELOP OVER WESTERN WISCONSIN WITH A NOSE POINTED INTO
LAKE SUPERIOR. ANY KIND OF WEAK SHORTWAVE IMPULSE COULD INITIATE
CONVECTION WITH MID-LEVEL LAPSE RATES GREATER THAN 8C...BUT TOUGH TO
IDENTIFY ANY FEATURES ON SATELLITE OR IN THE MODELS. IF SOMETHING
WERE TO POP...WESTERN WISCONSIN LOOKS BETTER ON PAPER. BUT
UNCERTAINTY IS TOO HIGH TO INCLUDE IN THE FORECAST.
OTHERWISE...SOUTH FLOW WILL AGAIN SEND WAVES OF MARINE STRATUS AND
FOG NORTH ALONG THE LAKESHORE AND ACROSS DOOR COUNTY AND FAR NE
WISCONSIN. A WARM NIGHT AHEAD WITH LOWS IN THE MID TO UPPER 50S.
SUNDAY...SHORTWAVE ENERGY WILL PASS SOUTH OF THE AREA WHILE
MID-LEVEL HEIGHTS BUILD OVERHEAD. AS A RESULT...SEEING STRONGER
CAPPING ON PROGGED SOUNDINGS WHICH SHOULD KEEP A LID ON SHOWER AND
THUNDERSTORM DEVELOPMENT. WILL GO DRY ONCE AGAIN. HIGHS AGAIN IN
THE UPPER 70S TO LOWER 80S...BUT COOLER NEAR LAKE MICHIGAN WHERE THE
ONSHORE COMPONENT WILL BE A LITTLE STRONGER.
.LONG TERM...SUNDAY NIGHT THRU FRIDAY. MAIN FORECAST CHALLENGES
ARE TEMPS...PRECIP CHANCES...AND FOG POTENTIAL.
SUMMER-LIKE PATTERN CONTINUES INTO EARLY NEXT WEEK AS UPPER RIDGE
BUILDS ACROSS THE EASTERN U.S. AND SOUTHERLY FLOW USHERS IN WARM
AIR AND RELATIVELY HIGH DEWPOINTS. TROUGH ACROSS THE WESTERN U.S.
WILL CROSS INTO THE PLAINS ON WEDNESDAY...AND TRANSITION INTO A
CUT OFF LOW THAT SLOWLY MOVES SOUTH OF THE GREAT LAKES LATE NEXT
WEEK. MODELS DISAGREE ON THE EVOLUTION FROM A LONGWAVE TROUGH TO
A CUT OFF LOW...BOTH WITH LOCATION AND TIMING...BRINGING PLENTY OF
UNCERTAINTY INTO THE FORECAST. IN GENERAL...PLAN TO FOLLOW A
GFS/ECMWF BLEND.
SUNDAY NIGHT IS STILL LOOKING DRY...AS THE AREA REMAINS UNDER
UPPER RIDGING AND NO OBVIOUS TRIGGER FOR CONVECTION. CANNOT
TOTALLY RULE OUT A STRAY SHOWER OR STORM AS STEEP LAPSE RATES
REMAIN OVER THE AREA...BUT PREFER TO STAY WITH A DRY FORECAST.
CLOUDS WILL BE ON THE INCREASE OVERNIGHT AND ON MONDAY MORNING
THOUGH...AS MOISTURE INCREASES ALOFT. WILL START TO INCREASE
POPS ON MONDAY AND MONDAY NIGHT OVER THE AREA AS UPPER TROUGH AND
SHORTWAVE ENERGY APPROACH THE AREA. STILL BELIEVE THE MAJORITY OF
THE ACTIVITY WILL STAY TO OUR WEST...WHERE THE BETTER
MOISTURE/FORCING AND BAROCLINIC ZONE IS LOCATED...BUT WILL CARRY
LOW CHANCE POPS OVER CENTRAL AND NORTH-CENTRAL WI...WITH SLIGHT
CHANCE POPS BUFFERING THIS AREA TO THE EAST. THE EXTENDED DRY
SPELL (AT LEAST FOR MOST LOCATIONS) WILL COME TO AN END TUESDAY OR
WEDNESDAY...AS THE UPPER TROUGH AND A NORTHERN PLAINS SHORTWAVE
CONVERGE ON THE AREA. POPS WILL NEED TO BE ADJUSTED FOR TUESDAY AS
THE TIMING IS PINNED DOWN...BUT PLAN TO STICK WITH CHANCE POPS
WEST AND SLIGHTS EAST TO COVER FOR NOW. HIGHEST POPS WILL BE
PLACED ON WEDNESDAY...AS THERE IS ENOUGH MODEL CONSENSUS SHOWING
PRECIP OVER THE AREA. THE UNSETTLED WEATHER LOOKS TO CONTINUE INTO
THE END OF THE WEEK AS THE UPPER LOW DRIFTS SOUTH OF THE
AREA...HOWEVER CONFIDENCE IS LOW ON THE OVERALL PATTERN. WITH
MODELS DIFFERING ON THE TIMING AND LOCATION OF THE CUT OFF
LOW...AS WELL AS A POSSIBLE SHORTWAVE OVER THE NORTHERN
PLAINS...IT WILL BE HARD TO SAY WITH CONFIDENCE WHERE THE BEST
CHANCES FOR PRECIP RESIDE AND WHEN TO GO DRY. HAVE LOW CHANCE AND
SLIGHT POPS TO COVER THIS UNCERTAINTY. DOWNPLAYED THUNDER
POTENTIAL FOR MANY OF THE PERIODS...ESPECIALLY AT NIGHT...AS
CONVECTIVE PARAMETERS ARE NOT OVERLY IMPRESSIVE.
AS FOR FOG...WILL CONTINUE TO HIGHLIGHT ON LAKE MICHIGAN AND MUCH
OF THE BAY THROUGH MID-WEEK AS UNSEASONABLY HIGH DEWPOINTS TRAVEL
ACROSS THE RELATIVELY COOLER WATERS. WILL ALSO MENTION FOG ALONG
THE IMMEDIATE SHORELINE AS ANY FOG BANK THAT DEVELOPS COULD DRIFT
INLAND. WITH DEWPOINTS IN THE 50S TO NEAR 60 THROUGH MID-
WEEK...DO EXPECT PATCHY FOG ELSEWHERE SOME NIGHTS IF WINDS CAN
DECOUPLE AND SKIES ARE CLEAR. BEST CHANCE FOR THIS WILL BE SUNDAY
NIGHT...SO WILL CONTINUE TO MENTION FOG ACROSS THE ENTIRE CWA.
WINDS LOOK TO STAY UP THE REST OF THE NIGHTS TO KEEP THE THREAT OF
FOG LOW.
RECORD OR NEAR RECORD WARMTH WILL CONTINUE ON MONDAY AND
TUESDAY AS PERSISTENT SOUTHERLY FLOW CONTINUES TO USHER IN WELL
ABOVE NORMAL TEMPS. TUESDAY LOOKS TO BE THE LAST DAY IN THE 70S
FOR PORTIONS OF CENTRAL AND EAST-CENTRAL WISCONSIN...BEFORE THE
CLOUDS AND PRECIP HOLD TEMPS IN THE MID/UPPER 50S NORTH AND LOW
60S SOUTH FOR THE END OF THE WORK WEEK. THESE MAY BE A LITTLE
GENEROUS IF PRECIP/CLOUD COVER ARE WIDESPREAD ENOUGH. ALTHOUGH
TEMPS WILL BE SIGNIFICANTLY COOLER LATE IN THE WEEK COMPARED TO
EARLY IN THE WEEK...THEY WILL REMAIN ABOVE NORMAL.
&&
.AVIATION...VFR CONDITIONS EXPECTED THRU THIS EVENING AND THEN
QUESTIONS ARISE AS TO HOW MUCH FOG WL BE ABLE TO DVLP DURING THE
OVERNIGHT HOURS. PREVAILING SOUTHERLY WINDS WL CONT TO PUMP WARM/
MOIST AIR INTO NE WI AND WITH SURFACE WINDS DIMINISHING TO 5 TO 10
KTS LATER TNGT...AT LEAST PATCHY FOG/STRATUS DECK SHOULD FORM. FOR
NOW...HAVE MENTIONED MVFR VSBYS MAINLY AFTER MIDNGT AND CONTINUING
THRU 14Z SUNDAY. AN ISOLATED TSTM COULD ALSO POP TNGT AS A SHORTWAVE
LIFTS NE TOWARD SRN SECTIONS OF THE GREAT LKS. BELIEVE ANY TSTM
ACTIVITY TO BE TOO ISOLATED TO MENTION IN TAFS. LASTLY...HAVE KEPT
SOME MENTION OF LLWS TONIGHT AS WINDS JUST ABOVE THE SURFACE COULD
REACH 35 KTS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AK