Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/24/13
AREA FORECAST DISCUSSION
NWS TUCSON AZ
845 PM MST SAT FEB 23 2013
.SYNOPSIS...LOW PRESSURE WILL MOVE ACROSS THE FOUR CORNERS SUNDAY
BRINGING ANOTHER SHOT OF COLD AIR TO SOUTHEAST ARIZONA ABOARD BRISK
NORTHWEST WINDS. SNOW SHOWERS WILL GENERALLY BE CONFINED TO AREAS
NEAR THE EASTERN MOUNTAINS. CLEARING AND COLD MONDAY MORNING. DRY
WITH A WARMING TREND MOST OF THE REST OF THE WEEK.
&&
.DISCUSSION...CLEAR AND COOL AHEAD OF THE NEXT WEATHER SYSTEM.
STRONG TROUGH DIGGING THROUGH THE CENTRAL GREAT BASIN WITH A LOW
TRACKING THROUGH SOUTHERN UTAH TOWARD THE 4 CORNERS REGION TONIGHT.
ASSOCIATED COLD FRONT DRAPED THROUGH NORTHERN ARIZONA PUSHING INTO
OUR AREA IN THE EARLY MORNING HOURS. BASED ON LATE DAY 18Z
NAMDNG5...12Z ECMWF GUIDANCE AND HRRR TRENDS AS WELL AS TIMING OF
THE FRONTAL BOUNDARY WE ADJUSTED TEMPERATURES DOWN A FEW DEGREES
SUNDAY WHILE DOUBLING SNOW SHOWERS IN THE EASTERN MOUNTAINS AND
GRAHAM COUNTY. AN EARLY LOOK AT 00Z MODEL TRENDS REINFORCES THIS
IDEA AND MORE WITH LATEST HRRR TRENDS DEVELOPING MORE WIDESPREAD
SHOWER ACTIVITY THROUGH NORTHERN GRAHAM COUNTY EARLY SUNDAY
MORNING...SO ANOTHER UPDATE TO INCREASE SHOWERS STILL MAINLY
NORTHEAST OF TUCSON SUNDAY. SNOW AMOUNTS RAISED INTO THE 2 TO 5 INCH
RANGE IN THE SOUTHERN WHITE MOUNTAINS...STILL BELOW ADVISORY LEVELS.
THE WIND ADVISORY SUNDAY LOOKS GOOD EAST OF TUCSON AND IN MOUNTAINS.
&&
.PREV DISCUSSION...LOW PRESSURE TRACKING ACROSS GREAT BASIN AT THIS
TIME WILL BRING A COLDER SUNDAY TO SE AZ. THIS SYSTEM IS REMINISCENT
OF THE ONE THAT PASSED THROUGH ABOUT 2 WEEKS AGO WITH COLD AIR
EVIDENT ON SATELLITE IMAGERY DIVING SOUTHWARD ALONG CA/NV BORDER.
OPERATIONAL MODELS INITIALLY UNDERESTIMATED THE AMOUNT AND
SOUTHWESTWARD EXTENT OF THE PRECIPITATION DURING THAT EVENT.
HOWEVER MANY MEMBERS OF THE GFS ENSEMBLE HANDLED THE ABILITY OF THE
COLD AIR TO SQUEEZE PRECIPITATION OUT OF A RELATIVELY DRY
ATMOSPHERE. WITH THAT SAID THE GOING FORECAST THIS TIME AROUND WAS
ALREADY IN GOOD SHAPE AND ONLY MADE SLIGHT ADJUSTMENTS AS BACKED UP
BY GFS ENSEMBLES SHOWING PRECIP PERHAPS AS FAR SOUTHWEST AS THE
CATALINA MOUNTAINS SUNDAY MORNING. BEST CHANCES STILL APPEAR TO BE
IN THE WHITES WHERE A QUICK COUPLE OF INCHES OF SNOW COULD OCCUR.
WINDS WITH THIS SYSTEM FIGURE TO BE THE MAIN IMPACT AS A STRONG NW
FLOW FROM ABOUT 700 MB UPWARD CREATES STRONG WINDS ON MOUNTAIN TOPS
AND MIXES TO VALLEYS IN STRONG COLD AIR ADVECTION. GFS GUIDANCE
WIND SPEEDS LOOK TOO HIGH BUT NAM GUIDANCE PROBABLY TOO LOW
CONSIDERING THE GRADIENT THAT IS FORECAST. THE MIDDLE OF THE ROAD
STILL YIELDS WIND SPEEDS DURING THE AFTERNOON REACHING WIND ADVISORY
CRITERIA OF SUSTAINED AT 30 MPH IN VALLEYS AND 35 MPH ABOVE 5000
FEET. THE TUCSON METRO SHOULD REMAIN BELOW ADVISORY SPEEDS BUT BRISK
CONDITIONS ARE FORECAST DUE TO THE WIND COMBINING WITH TEMPERATURES
ONLY TOPPING OUT IN THE 50S.
YET ANOTHER FREEZE IS LIKELY IN THE TUCSON METRO SUNDAY NIGHT AFTER
WINDS SUBSIDE AND SKIES CLEAR. IT SHOULD GENERALLY BE A LIGHT FREEZE
HERE BUT DOWN NEAR 20 AGAIN IN THE VALLEYS OF GRAHAM AND COCHISE
COUNTIES.
AFTER THIS SYSTEM PASSES BY...THERE WILL BE ANOTHER COUPLE OF
SYSTEMS PASSING TO OUR EAST THIS UPCOMING WEEK. THE MAIN IMPACT FOR
SE AZ WILL BE GIVE US GLANCING BLOWS OF COOLER AIR...JUST ENOUGH TO
TEMPER OUR WARMING TREND SUCH THAT WE DO NOT CLIMB BACK ABOVE
SEASONAL NORMALS UNTIL THE WEEKEND WHEN THE GFS AND ECMWF BOTH AGREE
ON A RIDGE SETTING UP OVER SW US...KD
&&
.AVIATION...FEW-SCT CLOUDS AT 20K FT AND SFC WND GENERALLY LESS THAN
10 KTS THRU EARLY SUNDAY OR 24/15Z. INCREASING WIND FROM THE NW
SUNDAY AFTERNOON PEAKING AROUND 24/23Z WITH SUSTAINED 17-30 KTS AND
GUSTS AROUND 40 KTS...ESPECIALLY NEAR SAD AND DUG. MIDDLE LAYER
SCT-BKN 100-150 CLOUD DECK MOVING INTO THE AREA FROM 24/15Z THROUGH
25/06Z. SCT SHRA/SHSN WITH CIGS 030-060 AND MVFR NEAR MOUNTAINS
ESPECIALLY 24/16Z-22Z FROM KSAD NEWD. NW WIND DECREASING EARLY
SUNDAY EVENING AFTER 25/02Z AND BECOMING GENERALLY LESS THAN 10 KTS
AFTER 24/07Z. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A COLD LOW PRESSURE SYSTEM DROPPING INTO NORTHERN
ARIZONA AND NEW MEXICO WILL CAUSE STRONG NORTHWEST WINDS SUNDAY
AFTERNOON WITH SPEEDS EXCEEDING 30 MPH IN PORTIONS OF COCHISE AND
GRAHAM COUNTIES. MINIMUM HUMIDITY THRESHOLDS OF 15 PERCENT MAY BE
APPROACHED BRIEFLY BUT BE HELD IN CHECK BY THE COLDER TEMPERATURES
AND A MODEST MOISTURE INCREASE. THE FIRE DANGER RATING IS EXPECTED
TO REMAIN LOW TO MODERATE AS THIS SYSTEM PASSES THROUGH. WINDS
SUBSIDING LATE SUNDAY NIGHT WITH A RETURN TO MORE AVERAGE WIND
CONDITIONS ON MONDAY...ALTHOUGH TEMPERATURES WILL REMAIN COOL.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TO 7 PM MST SUNDAY FOR AZZ507>509-511>514.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
MEYER/GLUECK/DROZD/SAMPSON
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
513 PM EST FRI FEB 22 2013
.SYNOPSIS...
A LOW LEVEL WEDGE WILL REMAIN IN PLACE THROUGH SATURDAY. AN AREA
OF LOW PRESSURE WILL DEVELOP ALONG THE GULF COAST TONIGHT AND MOVE
UP THE CAROLINA COAST SATURDAY....PROVIDING MORE RAIN COVERAGE
TONIGHT AND SATURDAY. HIGH PRESSURE WILL BRIEFLY BUILD IN SUNDAY.
ANOTHER WEATHER SYSTEM WILL PROVIDE RAIN LATE SUNDAY NIGHT AND
MONDAY...FOLLOWED BY CLEARING TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LATE THIS AFTERNOON AND EARLY THIS EVENING...UPPER LEVEL RIDGE
AXIS HAS SHIFTED TO THE EAST COAST...WITH A MOIST SW FLOW OVER OUR
REGION. LOW LEVEL WEDGE OVER OUR FORECAST AREA...AS SURFACE HIGH
PRESSURE RIDGES DOWN THE EAST COAST. RADAR SHOWS THAT ONE AREA OF
LIGHT RAIN HAS SHIFTED TO THE EAST. LATEST 13 KM RUC RUN SHOWS
VERY WEAK SHORT WAVE OR RIPPLE IN UPPER FLOW MOVING EAST DURING
THE LATE AFTERNOON TIME PERIOD WITH LOW LEVEL MOISTURE TRANSPORT
TO THE REGION. ALSO...THE RUC13 HOURLY POPS HAVE CHANCES
INCREASING.
TONIGHT...AN UPPER DISTURBANCE WILL MOVE ACROSS OUR REGION
LEADING TO A STRONGER LOW LEVEL JET AND MORE ISENTROPIC LIFT
PRECIPITATION DEVELOPING AND MOVING INTO THE REGION...AS A LOW
PRESSURE WAVE DEVELOPS ALONG THE GULF COAST TONIGHT AND BEGINS TO
TRANSITION EASTWARD.
WITH WEDGE AND LOW CLOUDS REMAINING IN PLACE...WILL EXPECT TEMPS TO
REMAIN GENERALLY STEADY THROUGH TONIGHT. DID LOWER OVERNIGHT LOW
TEMPERATURES A BIT USING THE LAMP25 GUIDANCE AND THE MIN TEMPERATURE
SMART TOOL. CAME UP WITH MAINLY UPPER 30S NORTH TO LOWER 40S SOUTH.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
SURFACE LOW ALONG THE CAROLINA COAST WILL BE MOVING
NORTHEAST ALTHOUGH CONTINUED MOISTURE FLUX INTO THE
REGION....PRECIPITABLE WATER 2 STANDARD DEVIATIONS ABOVE NORMAL
EARLY. STRONGEST ISENTROPIC LIFT SHIFTING TO THE EAST BY AFTERNOON.
MODEL SURFACE ANALYSIS/T-SECTIONS INDICATE IN-SITU WEDGE WILL
CONTINUE THROUGH THE DAY AND EXPECT EXTENSIVE CLOUDINESS. AFTER
MORNING RAIN...SHIFTING EAST IN THE AFTERNOON...PATCHY LIGHT RAIN
AND OR DRIZZLE. CLEARING SHOULD BE DELAYED UNTIL AFTER 06Z SUNDAY
AS MID LEVEL SHORT WAVE TROUGH LIFTS NORTHEAST ACROSS THE MIDDLE
ATLANTIC AND FLOW SHIFTS FROM SOUTHWEST TO WEST. MET MAXIMUM
TEMPERATURE GUIDANCE LOOKS THE MOST REASONABLE FOR SATURDAY...MAV
WAY TOO HIGH GIVE IN-SITU WEDGE. BLEND OF LOCAL WEDGE AND MET
GUIDANCE FOR MAXIMUM TEMPERATURE...THIS IS SUPPORTED BY SREF.
COLD FRONT MOVING THROUGH SATURDAY NIGHT WITH DRYING BY SUNDAY
MORNING. DESPITE COLD ADVECTION EARLY SUNDAY...TEMPERATURES WILL
WARM TO ABOVE NORMAL VALUES DUE TO DOWNSLOPE FLOW. SURFACE RIDGE
AGAIN BUILDING INTO THE REGION FROM THE NORTH AND UPPER LEVEL FLOW
BECOMING SOUTH...WHICH WILL SET UP ANOTHER WEDGE SITUATION.
INCREASING CLOUDS AFTER MIDNIGHT WITH LIGHT RAIN POSSIBLE MAINLY
CSRA TOWARD MORNING.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
RIDGE OVER THE NORTHEASTERN STATES EXTENDING INTO THE
CAROLINAS...WEDGE COLD AIR DAMMING MONDAY. CONFIDENCE IS HIGH FOR
WIDESPREAD RAIN GIVEN DEGREE OF MOISTURE FLUX/ISENTROPIC LIFT SO
FORECAST POPS ABOVE MOS GUIDANCE. LOWERED HIGH TEMPERATURES BELOW
GUIDANCE FOR MONDAY. RAIN IS EXPECTED TO DIMINISH EARLY TUESDAY AS
SURFACE LOW MOVES TO THE NORTHEAST AND COLD ADVECTION DEVELOPS.
SEVERAL SHORT WAVES MOVING THROUGH THE REGION IN BROAD UPPER LEVEL
CYCLONIC FLOW...HOWEVER AIR MASS APPEARS DRY THROUGH THE REST OF
THE PERIOD...ALTHOUGH TEMPERATURES MORE LIKELY TO BE BELOW NORMAL.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
LOW LEVEL WEDGE IN PLACE AS HIGH PRESSURE RIDGES DOWN THE EAST COAST.
LATEST RADAR LOOPS SHOW LIGHT RAIN MOVING EAST. SO WE MAY HAVE A BREAK
IN THE RAINFALL FOR 2-3 HOURS. HOWEVER...REGIONAL RADARS SHOW MORE
RAIN IN SOUTHERN GEORGIA AND THE LATEST MODEL RUNS INDICATE THAT THIS
AREA WILL SPREAD ON INTO THE FORECAST AREA.
LATEST OBS INDICATING IFR CONDITIONS. WILL SOME LOWERING OF
VSBYS/CIGS TO LIFR AS RAIN MOVES IN TONIGHT. PRECIPITATION AND
LOW LEVEL WEDGE EXPECTED TO CONTINUE THROUGH AT LEAST MIDDAY
SATURDAY...POSSIBLY LONGER. SO NO SIGNIFICANT IMPROVEMENT IN
CIGS/VSBYS EXPECTED THROUGH AT LEAST SATURDAY MORNING.
EXTENDED AVIATION OUTLOOK...LOW CIGS AND POSSIBLY VSBYS MAY LINGER
INTO SATURDAY NIGHT...THOUGH GRADUAL IMPROVEMENT POSSIBLE. NO
IMPACTS TO AVIATION EXPECTED SUNDAY. DETERIORATING CONDITIONS
EXPECTED AGAIN LATE SUNDAY NIGHT AND MONDAY AS ANOTHER SYSTEM
PROVIDES PRECIPITATION AND WEDGE LIKE CONDITIONS. IMPROVING
CONDITIONS TUESDAY...WITH BREEZY CONDITIONS POSSIBLE. NO SIGNIFICANT
IMPACTS TO AVIATION EXPECTED WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1258 PM EST FRI FEB 22 2013
.PREV DISCUSSION...
UPDATE...
/ISSUED 1037 AM EST FRI FEB 22 2013/
BULK OF PRECIP HAS SHIFTED TO THE SOUTHEAST PART OF THE CWA AND
MAIN UPDATE TO THE FORECAST WAS DECREASE PRECIPITATION ACROSS
NORTH GEORGIA. GIVEN LOW CLOUDS...MOISTURE AND VERY LIGHT RETURNS
ON RADAR...HAVE MENTIONED DRIZZLE ACROSS NORTH GEORGIA FOR THIS
MORNING. ALTHOUGH PRECIP WILL CONTINUE ACROSS THE SOUTHEAST
PORTION OF THE CWA THROUGH THE AFTERNOON...THE HRRR HOLDS OFF ON
BRINGING BETTER RAIN CHANCES BACK INTO THE ATL METRO AREA UNTIL
LATE THIS AFTERNOON. OTHER HI RES MODELS SUGGEST A LATER TIME
FRAME WITH THE BETTER POPS BEGINNING TONIGHT FOR THE ATL AREA.
CURRENT FORECAST TRENDS TOWARD THE TIMING OF THE HRRR...BUT MAY
STILL BE ON THE EARLY SIDE.
MU CAPE THROUGH THE AFTERNOON IS AROUND 400 J/KG. WITH LIMITED
LIGHTNING STRIKES THIS MORNING...HAVE OPTED TO SHOW ISOLATED
THUNDER THROUGH 18Z AND THEN SCATTERED THUNDER FOR THE AFTERNOON
WITH THE BETTER HEATING OF THE DAY.
HAVE SEEN ONE RIVER SITE /CUMMING/ GO INTO FLOOD THIS MORNING BUT
WITH BULK OF PRECIP EXPECTED OVERNIGHT...THINK MOST HYDRO PROBLEMS
SHOULD HOLD OFF UNTIL TONIGHT.
11
SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...
/ISSUED 410 AM EST FRI FEB 22 2013/
GEORGIA REMAINS UNDER PERSISTENT SOUTHWESTERLY UPPER FLOW THROUGH
THE FORECAST. MAIN UPPER LOW/SHORT WAVE TRACK REMAINS WELL NORTH
OF THE STATE...HOWEVER RICH MOISTURE FEED...STALLED FRONTAL BOUNDARY
AND A SERIES OF WEAK TO MODERATE SHORT WAVES AND ASSOCIATED SURFACE
LOWS CONTINUE TO TRACK ACROSS THE REGION THROUGH THE SHORT TERM
FORECAST PERIOD. INSTABILITY REMAINS MARGINAL AND NO WIDESPREAD
SEVERE THUNDERSTORMS ARE EXPECTED...HOWEVER THE ACTIVITY ALONG AND
SOUTH OF THE FRONT WILL NEED TO BE WATCHED FOR THE POTENTIAL FOR
ISOLATED SEVERE WEATHER. MAIN THREAT CONTINUES TO BE THE PERSISTENT
HEAVY RAIN AND FLOODING POTENTIAL. AREA OF SHOWERS AND A FEW
THUNDERSTORMS CURRENTLY ALONG THE FRONT SINKS INTO CENTRAL GEORGIA
TAKING THE BETTER PRECIPITATION TOTALS WITH IT...BUT WIDESPREAD
LIGHT TO OCCASIONALLY MODERATE RAIN IS STILL POSSIBLE OVER THE
NORTH. RAINFALL RATES DIMINISH SOMEWHAT TODAY BUT HEAVY RAIN WILL
MOVE UP THE FRONTAL BOUNDARY AGAIN TONIGHT AND EARLY SATURDAY AS THE
NEXT WAVE SWEEPS UP THE FRONTAL BOUNDARY. STILL LOOKS LIKE A BIT OF
A BREAK IN THE ACTION SATURDAY NIGHT AS THE SHORT WAVE EXITS AND THE
FRONTAL BOUNDARY...AT LEAST TEMPORARILY... SINKS SOUTH OF THE
FORECAST AREA.
LATEST QPF REMAINS IN LINE WITH PREVIOUS TRENDS SO I DO NOT PLAN ON
ADJUSTING THE CURRENT FLOOD WATCH AT THIS TIME. CENTRAL GEORGIA HAS
THE POTENTIAL TO SEE OVER 4 INCHES OF RAIN BY EARLY SUNDAY MORNING
WITH SLIGHTLY LOWER BUT STILL SIGNIFICANT AMOUNTS OVER 2 INCHES
ALONG THE I-20/I-85 CORRIDOR.
20
LONG TERM /SUNDAY THROUGH THURSDAY/...
/ISSUED 410 AM EST FRI FEB 22 2013/
LONG TERM FORECAST REMAINS FULL OF ACTIVITY. THE FIRST SYSTEM IS
EXPECTED TO AFFECT THE CWA ON MONDAY AND POSSIBLY INTO TUESDAY. I
HAVE WORKED THREE SHIFTS ON THIS DESK HOPING THAT THE GUIDANCE
WOULD COME TO A CONSENSUS OR START CONVERGING ON A SOLUTION FOR
THIS SYSTEM. THEY HAVE NOT. THE EURO CONTINUES TO BE THE SLOWEST
OF ALL SOLUTIONS...AND IS FAVORED BY HPC. AS SUCH...DECIDED TO GO
WITH A THE EURO SOLUTION. THIS BRINGS THE WARM FRONT ACROSS THE
CWA DURING THE LATE AFTERNOON ON MONDAY. MOST OF CENTRAL GEORGIA
SHOULD BE IN THE WARM SECTOR. THE COLD FRONT IS EXPECTED TO
APPROACH THE CWA AROUND 06Z TUESDAY. DEPENDING ON HOW MUCH
MOISTURE RETURN CAN OCCUR IN THE WARM SECTOR...SBCAPES ARE
LOW...SO HAVE DECIDED TO INCLUDE A SLIGHT CHANCE FOR THUNDER. DEEP
LAYER SHEAR IS ABOUT 50 TO 80 KNOTS FROM SOUTH TO NORTH ACROSS THE
CWA...AND LOW LEVEL SHEAR LOOKS DECENT AT THIS TIME. THIS WILL
NEED TO BE WATCHED CLOSELY AS WE GET CLOSER TO THE EVENT.
THIS UPPER LEVEL LOW IS FORECAST TO CUTOFF ACROSS THE GREAT LAKES
REGION THROUGH THE REST OF THE PERIOD. COOLER AIR IS FORECAST TO
MOVE IN FROM THE NORTH AS SHORTWAVES CIRCULATE AROUND THE LOW. ONE
OF THESE SHORTWAVES COULD LEAD TO SOME PRECIP ACROSS NORTHERN
PORTIONS OF THE CWA LATER IN THE PERIOD.
ARG
&&
.AVIATION...
18Z UPDATE...
BULK OF PRECIP REMAINS SOUTH OF THE TAF SITES WITH SOME LIGHT
SHOWERS AROUND MCN. -DZ WILL CONTINUE ON AND OFF IN THE ATL AREA
THROUGH THIS AFTERNOON AND BETTER CHANCES OF -SHRA DO NOT RETURN
UNTIL 00-02Z FOR ATL. LIFR TO IFR CIGS WILL CONTINUE THROUGH SATURDAY
MORNING. ALTHOUGH ATL CIGS HAVE REACHED 400FT...COULD STILL SEE A
SLIGHT IMPROVEMENT TO 600FT AT SOME POINT THIS AFTERNOON. LARGE
DISCREPANCIES ON WIND DIRECTION SATURDAY AFTERNOON...SO CONFIDENCE
ON WIND DIRECTION IS LOW.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON CIGS AND VSBYS. HIGH CONFIDENCE ON
WIND...EXCEPT LOW CONFIDENCE ON DIRECTION AFTER 12Z SATURDAY.
MEDIUM CONFIDENCE ON TIMING OF SHRA RETURNING.
11
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 48 43 55 41 / 90 100 80 10
ATLANTA 52 46 59 39 / 80 100 80 10
BLAIRSVILLE 48 41 54 35 / 70 100 80 10
CARTERSVILLE 53 45 59 37 / 70 100 80 10
COLUMBUS 63 56 65 43 / 100 100 80 20
GAINESVILLE 49 42 54 40 / 80 100 80 10
MACON 62 54 64 43 / 100 100 90 20
ROME 55 45 60 35 / 60 90 70 10
PEACHTREE CITY 54 47 61 39 / 90 100 80 10
VIDALIA 70 58 69 51 / 100 100 80 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES:
BALDWIN...BANKS...BARROW...BIBB...BLECKLEY...BUTTS...CARROLL...
CHATTAHOOCHEE...CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...
CRISP...DEKALB...DODGE...DOOLY...DOUGLAS...EMANUEL...FAYETTE...
FORSYTH...GLASCOCK...GREENE...GWINNETT...HALL...HANCOCK...
HARALSON...HARRIS...HEARD...HENRY...HOUSTON...JACKSON...JASPER...
JEFFERSON...JOHNSON...JONES...LAMAR...LAURENS...MACON...
MADISON...MARION...MERIWETHER...MONROE...MONTGOMERY...MORGAN...
MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...
PAULDING...PEACH...PIKE...POLK...PULASKI...PUTNAM...ROCKDALE...
SCHLEY...SOUTH FULTON...SPALDING...STEWART...SUMTER...TALBOT...
TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...TREUTLEN...TROUP...
TWIGGS...UPSON...WALTON...WARREN...WASHINGTON...WEBSTER...
WHEELER...WILCOX...WILKES...WILKINSON.
&&
$$
SHORT TERM...20/11
LONG TERM....ARG
AVIATION...11
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1037 AM EST FRI FEB 22 2013
.UPDATE...
BULK OF PRECIP HAS SHIFTED TO THE SOUTHEAST PART OF THE CWA AND
MAIN UPDATE TO THE FORECAST WAS DECREASE PRECIPITATION ACROSS
NORTH GEORGIA. GIVEN LOW CLOUDS...MOISTURE AND VERY LIGHT RETURNS
ON RADAR...HAVE MENTIONED DRIZZLE ACROSS NORTH GEORGIA FOR THIS
MORNING. ALTHOUGH PRECIP WILL CONTINUE ACROSS THE SOUTHEAST
PORTION OF THE CWA THROUGH THE AFTERNOON...THE HRRR HOLDS OFF ON
BRINGING BETTER RAIN CHANCES BACK INTO THE ATL METRO AREA UNTIL
LATE THIS AFTERNOON. OTHER HI RES MODELS SUGGEST A LATER TIME
FRAME WITH THE BETTER POPS BEGINNING TONIGHT FOR THE ATL AREA.
CURRENT FORECAST TRENDS TOWARD THE TIMING OF THE HRRR...BUT MAY
STILL BE ON THE EARLY SIDE.
MU CAPE THROUGH THE AFTERNOON IS AROUND 400 J/KG. WITH LIMITED
LIGHTNING STRIKES THIS MORNING...HAVE OPTED TO SHOW ISOLATED
THUNDER THROUGH 18Z AND THEN SCATTERED THUNDER FOR THE AFTERNOON
WITH THE BETTER HEATING OF THE DAY.
HAVE SEEN ONE RIVER SITE /CUMMING/ GO INTO FLOOD THIS MORNING BUT
WITH BULK OF PRECIP EXPECTED OVERNIGHT...THINK MOST HYDRO PROBLEMS
SHOULD HOLD OFF UNTIL TONIGHT.
11
&&
.PREV DISCUSSION...
SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...
/ISSUED 410 AM EST FRI FEB 22 2013/
GEORGIA REMAINS UNDER PERSISTENT SOUTHWESTERLY UPPER FLOW THROUGH
THE FORECAST. MAIN UPPER LOW/SHORT WAVE TRACK REMAINS WELL NORTH
OF THE STATE...HOWEVER RICH MOISTURE FEED...STALLED FRONTAL BOUNDARY
AND A SERIES OF WEAK TO MODERATE SHORT WAVES AND ASSOCIATED SURFACE
LOWS CONTINUE TO TRACK ACROSS THE REGION THROUGH THE SHORT TERM
FORECAST PERIOD. INSTABILITY REMAINS MARGINAL AND NO WIDESPREAD
SEVERE THUNDERSTORMS ARE EXPECTED...HOWEVER THE ACTIVITY ALONG AND
SOUTH OF THE FRONT WILL NEED TO BE WATCHED FOR THE POTENTIAL FOR
ISOLATED SEVERE WEATHER. MAIN THREAT CONTINUES TO BE THE PERSISTENT
HEAVY RAIN AND FLOODING POTENTIAL. AREA OF SHOWERS AND A FEW
THUNDERSTORMS CURRENTLY ALONG THE FRONT SINKS INTO CENTRAL GEORGIA
TAKING THE BETTER PRECIPITATION TOTALS WITH IT...BUT WIDESPREAD
LIGHT TO OCCASIONALLY MODERATE RAIN IS STILL POSSIBLE OVER THE
NORTH. RAINFALL RATES DIMINISH SOMEWHAT TODAY BUT HEAVY RAIN WILL
MOVE UP THE FRONTAL BOUNDARY AGAIN TONIGHT AND EARLY SATURDAY AS THE
NEXT WAVE SWEEPS UP THE FRONTAL BOUNDARY. STILL LOOKS LIKE A BIT OF
A BREAK IN THE ACTION SATURDAY NIGHT AS THE SHORT WAVE EXITS AND THE
FRONTAL BOUNDARY...AT LEAST TEMPORARILY... SINKS SOUTH OF THE
FORECAST AREA.
LATEST QPF REMAINS IN LINE WITH PREVIOUS TRENDS SO I DO NOT PLAN ON
ADJUSTING THE CURRENT FLOOD WATCH AT THIS TIME. CENTRAL GEORGIA HAS
THE POTENTIAL TO SEE OVER 4 INCHES OF RAIN BY EARLY SUNDAY MORNING
WITH SLIGHTLY LOWER BUT STILL SIGNIFICANT AMOUNTS OVER 2 INCHES
ALONG THE I-20/I-85 CORRIDOR.
20
LONG TERM /SUNDAY THROUGH THURSDAY/...
/ISSUED 410 AM EST FRI FEB 22 2013/
LONG TERM FORECAST REMAINS FULL OF ACTIVITY. THE FIRST SYSTEM IS
EXPECTED TO AFFECT THE CWA ON MONDAY AND POSSIBLY INTO TUESDAY. I
HAVE WORKED THREE SHIFTS ON THIS DESK HOPING THAT THE GUIDANCE
WOULD COME TO A CONSENSUS OR START CONVERGING ON A SOLUTION FOR
THIS SYSTEM. THEY HAVE NOT. THE EURO CONTINUES TO BE THE SLOWEST
OF ALL SOLUTIONS...AND IS FAVORED BY HPC. AS SUCH...DECIDED TO GO
WITH A THE EURO SOLUTION. THIS BRINGS THE WARM FRONT ACROSS THE
CWA DURING THE LATE AFTERNOON ON MONDAY. MOST OF CENTRAL GEORGIA
SHOULD BE IN THE WARM SECTOR. THE COLD FRONT IS EXPECTED TO
APPROACH THE CWA AROUND 06Z TUESDAY. DEPENDING ON HOW MUCH
MOISTURE RETURN CAN OCCUR IN THE WARM SECTOR...SBCAPES ARE
LOW...SO HAVE DECIDED TO INCLUDE A SLIGHT CHANCE FOR THUNDER. DEEP
LAYER SHEAR IS ABOUT 50 TO 80 KNOTS FROM SOUTH TO NORTH ACROSS THE
CWA...AND LOW LEVEL SHEAR LOOKS DECENT AT THIS TIME. THIS WILL
NEED TO BE WATCHED CLOSELY AS WE GET CLOSER TO THE EVENT.
THIS UPPER LEVEL LOW IS FORECAST TO CUTOFF ACROSS THE GREAT LAKES
REGION THROUGH THE REST OF THE PERIOD. COOLER AIR IS FORECAST TO
MOVE IN FROM THE NORTH AS SHORTWAVES CIRCULATE AROUND THE LOW. ONE
OF THESE SHORTWAVES COULD LEAD TO SOME PRECIP ACROSS NORTHERN
PORTIONS OF THE CWA LATER IN THE PERIOD.
ARG
AVIATION...
12Z UPDATE...
/ISSUED 635 AM EST FRI FEB 22 2013/
MIXTURE OF MVFR AND IFR CONDITIONS ACROSS THE FORECAST AREA WILL
CONTINUE THROUGH 00Z. ALL AREAS WILL TREND TOWARD IFR BY 06Z WITH
AREAS OF LIFR DEVELOPING AFTER 06Z. WINDS WILL REMAIN EASTERLY...
GENERALLY 6-10KT ALTHOUGH PERIODS OF GUSTY CONDITIONS WILL OCCUR
THROUGH AROUND 16-18Z ACROSS MOST AREAS. BEST PRECIPITATION
COVERAGE WILL BE ACROSS CENTRAL GEORGIA WITH SOME THUNDER POSSIBLE
THERE AS WELL. BETTER COVERAGE OF RAIN WILL EXPAND BACK NORTH
AFTER 00Z.
//ATL CONFIDENCE...12Z UPDATE...
CONFIDENCE IS MEDIUM ON ALL ELEMENTS.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 48 43 55 41 / 90 100 80 10
ATLANTA 52 46 59 39 / 80 100 80 10
BLAIRSVILLE 48 41 54 35 / 70 100 80 10
CARTERSVILLE 53 45 59 37 / 70 100 80 10
COLUMBUS 63 56 65 43 / 100 100 80 20
GAINESVILLE 49 42 54 40 / 80 100 80 10
MACON 62 54 64 43 / 100 100 90 20
ROME 55 45 60 35 / 60 90 70 10
PEACHTREE CITY 54 47 61 39 / 90 100 80 10
VIDALIA 70 58 69 51 / 100 100 80 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES:
BALDWIN...BANKS...BARROW...BIBB...BLECKLEY...BUTTS...CARROLL...
CHATTAHOOCHEE...CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...
CRISP...DEKALB...DODGE...DOOLY...DOUGLAS...EMANUEL...FAYETTE...
FORSYTH...GLASCOCK...GREENE...GWINNETT...HALL...HANCOCK...
HARALSON...HARRIS...HEARD...HENRY...HOUSTON...JACKSON...JASPER...
JEFFERSON...JOHNSON...JONES...LAMAR...LAURENS...MACON...
MADISON...MARION...MERIWETHER...MONROE...MONTGOMERY...MORGAN...
MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...
PAULDING...PEACH...PIKE...POLK...PULASKI...PUTNAM...ROCKDALE...
SCHLEY...SOUTH FULTON...SPALDING...STEWART...SUMTER...TALBOT...
TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...TREUTLEN...TROUP...
TWIGGS...UPSON...WALTON...WARREN...WASHINGTON...WEBSTER...
WHEELER...WILCOX...WILKES...WILKINSON.
&&
$$
SHORT TERM...20/11
LONG TERM....ARG
AVIATION...20
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
640 PM EST SAT FEB 23 2013
.AVIATION...
MVFR CIGS ACROSS THE AREA THIS EVENING. SATELLITE SHOWS CLEARING
ACROSS IL TRYING TO WORK NORTHEAST. ITS DOUBTFUL THIS CLEARING WILL
BE ABLE TO REACH TAF SITES BEFORE LOW LEVEL FLOW VEERS IN WAKE OF
MID LEVEL TROUGH AND ADDITIONAL SYNOPTIC MOISTURE COUPLED WITH LAKE
MOISTURE MOVES SOUTHEAST. LATEST RAP LOW LEVEL RH PROGS SUGGEST
CLOUDS WILL HANG ACROSS THE REGION SO KEPT TAFS IN MVFR RANGE. A FEW
LIGHT SNOW SHOWERS AND FLURRIES EXPECTED BUT LITTLE TO NO IMPACT TO
TAF SITES EXPECTED. CONDITIONS EXPECTED TO IMPROVE LATE SUNDAY TO
VFR AS FLOW BACKS AND DRIER AIR MOVES IN.
&&
.SHORT TERM.../TONIGHT-SUNDAY NGT/
VERTICALLY STACKED LOW PRESSURE SYSTEM CENTERED OVER THE ERN U.P.
THIS AFTN WILL MOVE SLOWLY EAST TONIGHT WITH TRAILING TROF MOVG
ACROSS OUR AREA. VEERING WINDS OVER SRN LM SHOULD RESULT IN GRADUAL
REORIENTATION OF LAKE EFFECT SNOW BANDS AS FAR SOUTH AS FAR NRN
INDIANA. ALTHOUGH LAKE INDUCED INSTABILITY WILL BE LIMITED WITH
DELTA T`S ONLY 12C TO 13C... INCREASE IN MID LEVEL MOISTURE
ACCOMPANYING THE TROF SHOULD RESULT IN AN SCT SNOW SHOWERS WITH
LIGHT ACCUMS... MAINLY ACROSS SRN MI. EXPECT CLOUDS AND GRADIENT
MIXING WILL HOLD TEMPS UP A BIT ABOVE LATEST MOS GUIDANCE FOR LOWS
TONIGHT.
UPR GRTLKS LOW WILL ACCELERATE EASTWARD SUNDAY AS IT GETS ABSORBED
BY STRENGTHENING LOW OFF THE NEW ENGLAND COAST. THIS FEATURE
COMBINED WITH DEEPENING LOW OVER THE SRN PLAINS WILL RESULT IN A
STRENGHTENING RIDGE MOVG INTO THE WRN GRTLKS/OH VALLEY SUNDAY-SUNDAY
NIGHT. LOW CLOUDS OVER THE AREA SHOULD GRDLY ERODE FROM THE SW
SUNDAY-SUNDAY EVE AS LOW MOVES AWAY AND LOW LEVEL FLOW BECOMES
ANTICYCLONIC... WITH VANGUARD HIGH CLOUDS AHEAD OF SRN PLAINS LOW
MOVG INTO THE SW LATE SUNDAY NIGHT. WK MIXING SHOULD PREVENT WAA
ALOFT ASSOCIATED WITH UPR RIDGE BUILDING INTO THE AREA FROM HAVING
MUCH AFFECT IN OUR AREA THROUGH THIS PERIOD WITH HIGHS SUNDAY
JUST SLIGHTLY WARMER THAN TODAY... AND LOWS SUNDAY NIGHT UNDER GOOD
RADIATIONAL COOLING GENERALLY A LITTLE COOLER THAN SATURDAY NIGHT.
&&
.LONG TERM...
MONDAY THROUGH SATURDAY...THE MAIN CHALLENGES THIS PERIOD CONTINUE
TO BE LATE MONDAY NIGHT THROUGH TUESDAY INTO TUESDAY NIGHT WHEN AN
UPPER LEVEL SYSTEM EJECTS NORTH OF THE OHIO RIVER. FOR THIS
PACKAGE...FAVORED THE ECMWF OPERATIONAL RUN WITH INCREASING SUPPORT
FROM THE NAM/WRF....TRENDING TOWARD A SLIGHTLY SLOWER SOLUTION. THE
CANADIAN GEM 00Z RUN APPEARED TO BE A MAJOR OUTLIER...BUT NOW
SUPPORTS THE EC. THE EC APPEARS TO HAVE THE BEST RUN TO RUN SUPPORT
OF THE POSITION OF THE UPPER LOW AND SFC LOW. CIPS ANALOGS WERE
SHOWING VERY LOW SCORES FOR THIS EVENT...NOT HELPING MUCH WITH FCST
CONFIDENCE THIS PACKAGE. THE ONGOING GRIDS/FCST MONDAY NIGHT INTO
TUESDAY REFLECTS MUCH OF CURRENT THINKING WITH A WINTRY MIX OF
PRECIP DEVELOPING RAPIDLY...BECOMING ALL SNOW MOST AREAS AROUND OR
AFTER DAYBREAK TUESDAY. WAS HESITANT TO ADD HEAVY SNOW TUESDAY
MORNING AS WELL DEFINED TROWAL MOVES ACROSS THE AREA GIVEN THERMAL
PROFILES TEMPS EXCEEDING 5C IN THE LOWER LAYER ON THE LATEST BUFKIT
AT FWA AT 14Z. CURRENT THINKING IS PRECIP WILL DEVELOP RAPIDLY AS A
MAINLY A FREEZING RAIN/SNOW MIX...OR JUST FREEZING RAIN SOUTHEAST
AREAS...AND THEN TRANSITION TO ALL SNOW VERY FAST WITH MASSIVE
DIABATIC COOLING OF LOWER LAYERS. CURRENT THINKING IS ICE POTENTIAL
COULD REACH OVER 1/4 INCH IF THERE IS ANY DELAY IN THE CHANGEOVER
DUE TO WARM LAYER AND IF SFC TEMPS REMAIN BELOW FREEZING.
OTHERWISE...SYSTEM WILL BECOME COMPLETELY CUT OFF WITH LINGERING
LIGHT SNOW SHOWERS FOR AN EXTENDED TIME. KEPT TEMPS BELOW TO MUCH
BELOW NORMAL FOR THE REST OF THIS PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL NOON EST SUNDAY FOR LMZ043.
&&
$$
SHORT TERM...JT
LONG TERM...SKIPPER
AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
259 PM CST FRI FEB 22 2013
.SYNOPSIS...
ISSUED AT 257 PM CST FRI FEB 22 2013
SLOWLY FILLING SURFACE LOW THAT HAS MOVED NORTH ACROSS THE FORECAST
AREA TODAY IS CONTINUING TO MOVE UP INTO SOUTHERN WISCONSIN...AND AS
OF 2 PM WAS LOCATED WEST OF MADISON WISCONSIN...WITH A BROAD AREA OF
PRESSURE FALLS OVER WISCONSIN. A VERY WEAK TROUGH AXIS EXTENDS BACK
INTO NORTHERN IOWA...WHERE SNOW CONTINUES TO FALL VERY LIGHTLY. LOW
CLOUDS EXTEND BACK INTO NORTHERN MISSOURI. THERE IS AN AREA IN
NORTHWEST MISSOURI WHERE THE CLOUDS HAVE EITHER THINNED OR CLEARED
OUT ENTIRELY AS WE CAN SEE THE TEXTURE OF THE GROUND BENEATH ON
VISIBLE SATELLITE IMAGERY. THIS IS IN A OBSERVATIONAL DATA VOID
AREA...SO IT IS HARD TO DETERMINE WHAT EXACTLY IS GOING ON. AT
UPPER LEVELS...BROAD UPPER LEVEL TROUGH OVER THE WESTERN CONUS WITH
THE STRONG SHORTWAVE OVER THE MIDWEST ASSOCIATED WITH THIS STORM
SYSTEM. STRONG PRESSURE FALLS AHEAD OF THE SHORTWAVE IMPLY THAT IT
WILL CONTINUE NORTHEAST...BUT SMALL RISES BEHIND IT SHOW THAT IT IS
FILLING AND THE BROADER SCALE TROUGH IS STILL DEEPENING. ..LE..
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 257 PM CST FRI FEB 22 2013
THIS AFTERNOON THE SNOW BAND IS EXPECTED TO CONTINUE TO MOVE
NORTHEAST OUT OF THE AREA...AND PLAN ON ALLOWING THE WINTER STORM
WARNING AND ADVISORY EXPIRE HERE AT 3 PM. SOME FLURRIES WILL LIKELY
STILL AFFECT THE NORTHERN THIRD OF THE FORECAST AREA WITH SOME LOW
LEVEL CONVERGENCE AND LIFT GOING ON ACCORDING TO THE RUC THIS
EVENING. THUS...HAVE CONTINUED THE SLIGHT CHANCE POPS THIS EVENING
BUT WITH NO ACCUMULATIONS EXPECTED.
TONIGHT THE SURFACE LOW EJECTS OFF TO THE NORTHEAST...AND WILL BE
OVER THE UP OF MICHIGAN BY 06Z TONIGHT. THAT WILL DRAW THE LIFT AND
MOST OF THE MOISTURE OFF TO THE NORTHEAST...LEAVING US WITH SOME
LINGERING LOW LEVEL MOISTURE. IN FACT...ACCORDING TO SOUNDINGS WE
REMAIN FAIRLY WELL SATURATED BELOW 850MB THROUGH SATURDAY MORNING.
FLURRIES SHOULD BE POSSIBLE AS THE LEAST LITTLE WIGGLE IS GOING TO
PRODUCE THEM. IT APPEARS THAT WE WILL BE COLD ENOUGH AT THE TOP OF
THAT LAYER FOR THESE TO BE FLURRIES INSTEAD OF FREEZING DRIZZLE..BUT
LATER SHIFTS WILL HAVE TO WATCH FOR THIS. UPSTREAM MIN TEMPERATURES
FELL INTO THE TEENS OVER NEBRASKA AND KANSAS LAST NIGHT...SO HAVE
KEPT THE MIN TEMPS IN THE TEENS OVERNIGHT. MAY BE SLIGHTLY WARMER
WITH THE EXTRA CLOUD COVER...SO DID NOT BRING IN ANY SINGLE DIGIT
VALUES. THE EXTRA CLOUD COVER IS ALSO GOING TO KEEP TEMPS FROM
FALLING OFF VERY FAST OVERNIGHT...SO A SLOW DROP OFF IN THE EVENING
IS EXPECTED.
SATURDAY TO BE COLD AND QUIET WITH THE STORM OFF TO THE NORTHEAST
AND A GRADUAL CLEARING TREND FROM THE SOUTH. WE ARE NOT BRINGING IN
A COLD AIRMASS BEHIND THIS SYSTEM...BUT WITH THE SNOW COVER WE ARE
GOING TO BE COLDER THAN WE WOULD WITHOUT. SO...EXPECT HIGHS IN THE
20S TO NEAR 30. LINGERING LOW LEVEL MOISTURE SHOULD LIFT TO
AFTERNOON STRATOCUMULUS...BUT STILL ALLOWING A FAIR AMOUNT OF
SUNSHINE THROUGH. ..LE..
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 257 PM CST FRI FEB 22 2013
ANOTHER MAJOR AND STRONGER WINTER STORM FOR MONDAY/TUESDAY THE MAIN
FORECAST CHALLENGE.
OVERVIEW...INITIALIZATION GOOD TO EXCELLENT UPSTREAM INTO THE NORTH
PACIFIC. THE 18Z VERIFICATION SUPPORT ALL 4 LONGER RANGE SOLUTIONS
VERIFYING WELL AND ARE ALL SIMILAR. THATS THE GOOD NEWS...UNLESS ONE
LIKES LOTS OF SNOW...THEY ALL PUT AREA IN THE WHEELHOUSE OF A MAJOR
WINTER STORM WITH STRONG WINDS. PREFER A BLEND OF ALL 4 AS A MIX
WHICH SUPPORTS MOST OR ALL THE AREA TO PICK UP ANOTHER 4-6+ INCHES OF
SNOW WITH LOCALLY UP TO OVER 12 INCHES POSSIBLE WITH WINDS OF 20 TO
35+ MPH AND POSSIBLY HIGHER. THE CONSISTENCY OF FORCING OF UPPER JET
STRUCTURE TOOLS ALL SUGGEST IF THIS TREND CONTINUES THE NEXT 24 HOURS
THAT OUR AREA WILL SEE A MAJOR...HIGHER END WINTER STORM EVENT WITH
POSSIBLE NEAR BLIZZARD CONDITIONS. WILL UPDATE THE LOCAL HWODVN
HAZARDOUS WEATHER OUTLOOK PRODUCT FOR STRONGER AND HIGHER IMPACT
WORDING.
SATURDAY NIGHT AND SUNDAY...VERY MINOR CHANGES WITH LESS CLOUDS ARE
LIKELY SUPPORTING LOWER MINS FROM OUR SNOW-PACK AND HIGHER MAX TEMP
VALUES FROM LATE FEBRUARY SUNSHINE. LATER SHIFTS MAY NEED TO BUMP
HIGHS A FEW MORE DEGREES DUE TO THE SUNSHINE. SUNDAY NIGHT...SEE
INCREASING CLOUDS AND KEPT VERY LOW POPS FAR WEST SECTIONS OVERNIGHT
AS LEADING EDGE OF ELEVATED FORCING FOR THE NEXT MAJOR WINTER STORM
ARRIVES WITH MAIN BRUNT OF FORCING ON TAP TO IMPACT THE AREA LATER ON
MONDAY PM HOURS INTO TUESDAY.
MONDAY THROUGH NEXT WEDNESDAY...HAVE UPPED POPS MONDAY NIGHT AND
TUESDAY TO LIKELY WITH MODERATE TO HEAVY SNOW AMOUNTS SUGGESTED.
NUMEROUS TOOLS SUGGEST MOST OF THE AREA TO SEE WELL OVER 4+ INCHES
WITH MOST RELIABLE TOOLS ALL SUGGESTING A SWATH OF 6-12+ INCHES OF
HEAVY SNOW THAT RIGHT NOW IS TRENDING TOWARD A IRK-MUS-FEP LINE.
THIS SHOULD BE BETTER CLARIFIED IN THE NEXT 24 HOURS. IF PHASING
ON THE BACK SIDE OCCURS AS SUGGESTED BY SOME SOLUTIONS WITH STRONGER
OCCLUSION THEN STRONGER COLD CONVEYOR BELT SUGGESTED AND NEAR
BLIZZARD CONDITIONS LIKELY. SOME TOOLS SUGGEST WIND GUSTS OF 40-45
MPH WHICH ARE VERY CLOSE TO BLIZZARD THRESHOLD FOR LATER SHIFTS TO
MONITOR. THERE IS NO DOUBT THIS WILL BE A MAJOR EVENT LAST 12-18+
HOURS AND LIKELY GREATER THAN THE EVENT THE PAST 24 HOURS. THIS IS
A DEVELOPING SYSTEM THAT WILL STRENGTHEN VERSUS A WEAKENING AND
FILLING SYSTEM THAT PASSED. ADD WERE IN THE NATURAL BAROCLINIC
ZONE OF A PRONOUNCED SNOW AND NO SNOW LINE...THIS MAKES RISK OF A
MAJOR EVENT GREATER. THE DATA AS OF NOW...SUPPORTS AT LEAST PART
OF THE AREA WILL SEE A MAJOR WINTER STORM. AREA SNOW TO LIQUID WATER
EQUIVALENT RATIOS ARE SUGGESTED TO BE IN THE 12-15 TO 1 RANGE. ARE
TEMPERATURES SHOULD STAY IN THE MID 20S TO LOWER 30S FOR THIS EVENT.
THURSDAY AND FRIDAY...DRY WITH BELOW NORMAL TEMPERATURES AND WITH
AN EVEN GREATER THICKER AND FRESH SNOW PACK LIKELY...AREA TEMPS ARE
AGAIN PROBABLY TOO MILD. MINS COULD BE AT LEAST 5 TO 10 DEGREES TOO
MILD FOR LATER SHIFTS TO RECONSIDER. NORTHWESTERLY FLOW AND BELOW
NORMAL TEMPERATURES REMAIN APPEAR LIKELY INTO THE FIRST FEW DAYS OF
MARCH...ALL INDICATIONS ARE THIS MARCH WILL NOTHING LIKE THE
RECORD WARM MARCH OF 2012.
NICHOLS
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 257 PM CST FRI FEB 22 2013
A BROAD AREA OF IFR CIGS CONTINUES OVER THE AREA WITH MAINLY VFR
VISIBILITIES. KDBQ AND SURROUNDING AREAS ARE GETTING IFR CIGS AND
VSBYS WITH SOME LINGERING LIGHT SNOW. THIS TO GRADUALLY IMPROVE IN
THE NEXT FEW HOURS TO JUST MVFR CIGS WITH VFR VSBYS. EXPECT THAT
MVFR CIGS WILL LINGER OVERNIGHT TONIGHT AND INTO SATURDAY MORNING.
PATCHES OF HIGHER CIGS MAY IMPACT KCID AND KDBQ THIS AFTERNOON AND
EARLY EVENING...BUT THESE ARE EXPECTED TO BE TEMPORARY...AND WILL
DEFINITELY FILL BACK IN AND LOWER BY 02Z. FOR NOW HAVE DECIDED TO
KEEP AN EYE ON SATELLITE AND IF LARGE ENOUGH HOLES APPEAR WILL PUT
IN A TEMPO GROUP. WINDS TO TURN WEST/SOUTHWEST THIS AFTERNOON AND
REMAIN THROUGH REMAINDER OF FORECAST AT LESS THAN 10KTS. CIGS TO
FINALLY COME TO VFR SATURDAY MORNING. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...LE
SHORT TERM...LE
LONG TERM...WDN
AVIATION...LE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
131 PM CST FRI FEB 22 2013
.UPDATE...
ISSUED AT 129 PM CST FRI FEB 22 2013
HAVE DECIDED TO CANCEL A PORTION OF THE WARNING AND ADVISORY AS
SNOW HAS TAPERED OFF TO FLURRIES FOR THESE AREAS. WILL LIKELY LET
THE REMAINING PORTIONS OF THE WARNING AND ADVISORY GO AT 3 PM AS
SCHEDULED. THIS IS BASED MAINLY OFF RADAR TRENDS WITH THAT LAST
LITTLE WAVE OF SNOW MOVING THROUGH THE NORTHERN PORTIONS OF THE
AREA. HAVE ALSO UPDATED OTHER ELEMENTS...BUT WITH LITTLE CHANGE.
&&
.SHORT TERM...TODAY AND TONIGHT
/ISSUED 316 AM CST FRI FEB 22 2013/
RUNNING BEHIND DUE TO OTHER PROBLEMS. FIRST...BASED ON RAP TRENDS
WILL DROP HEADLINES FOR ROUGHLY THE SOUTHERN THIRD. THE OTHER
HEADLINES WILL CONTINUE FOR NOW BUT MAY GET CANCELLED OR MODIFIED
OVER THE NEXT 3-4 HRS.
RAP TRENDS INDICATE THE WAA WING OF SNOW WILL BE IN MN/WI SHORTLY.
FLURRIES OR VERY LIGHT SNOW IS SPORADIC ACROSS THE AREA BUT VERY
LITTLE IN THE WAY OF NEW ACCUMULATION SHOULD BE SEEN THROUGH 12Z.
DURING THE DAY THE RAP DEVELOPS NEW FORCING AS THE OCCLUDED LOW
MOVES UP THROUGH THE FAR WESTERN CWFA WHICH SHOULD INDUCE SOME NEW
LIGHT SNOW DURING THE DAY ACROSS THE AREA. CONDENSATION PRESSURE
DEFICITS WILL SLOWLY RISE SO THERE SHOULD BE A GRADUAL END TO THE
SNOW FROM SOUTH TO NORTH DURING THE DAY.
ADDITIONAL ACCUMULATIONS FOR THE REMAINDER OF THE DAY SHOULD RANGE
FROM A DUSTING TO PERHAPS AN INCH.
TONIGHT...CYCLONIC FLOW SHOULD CONTINUE TO KEEP LIGHT
SNOW/FLURRIES GOING ACROSS ROUGHLY THE NORTH/NORTHEAST THIRD OF
THE CWFA DURING THE EVENING THAT GRADUALLY ENDS DURING THE NIGHT.
BASED ON TEMPERATURES CURRENTLY IN MISSOURI...THE EASTERN CWFA
SHOULD SEE READING GET TO OR JUST ABOVE FREEZING DURING THE
DAYLIGHT HOURS. ..08..
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
/ISSUED 316 AM CST FRI FEB 22 2013/
ANOTHER ACTIVE PERIOD IS LOOMING IN THE LONG TERM...WITH ALL
MODELS SHOWING A DYNAMIC SYSTEM MONDAY THROUGH MID WEEK. THERE IS
PLENTY OF MODEL SPREAD ON TIMING AND TRACK OF THIS SYSTEM...AS
WELL AS ITS EVENTUAL EVOLUTION INTO A MAJOR LONG WAVE TROF.
THUS...FOR NOW...AND WILL FULL SUPPORT OF THIS FORECASTER...WE
WILL TAKE SOME BABY STEPS TOWARD A WINTER EVENT...OF SNOW AND
POTENTIALLY WIND. I AM ENCOURAGED THAT BOTH THE 00Z
ECMWF..UKMET...GEM...AND NAM ALL TAKE THE SYSTEM SOUTH...WITH THE
BEST TRACK FOR HEAVY QPF OVER CWAS JUST SOUTH. NOT THAT THAT WILL
OCCUR...BUT I FEEL THIS WINTER REPRESENT YET ANOTHER YEAR THAT WE
MODELS WILL EVENTUALLY TRACK SYSTEMS A BIT FARTHER NORTH THAN
THEIR DAY 3 TO 7 FORECASTS. THE GFS REMAINS MUCH FARTHER
NORTH...WEAKER...AND FASTER THAN OTHER MODELS...AND IT LARGELY
DISREGARDED EXCEPT FOR INSERTING SOME SLIGHT CHANCE POPS FOR
SUNDAY NIGHT. IN THE END...IT WOULD SEEM SLOWER IS THE WAY TO GO
ON THIS SYSTEM...ESPECIALLY SINCE IT IS ANOTHER CLOSED UPPER LOW
SYNOPTIC SYSTEM. IT TRENDS HOLD TRUE ON THE ECMWF AND OTHERS...WE
ARE CERTAIN TO NEED CATEGORICAL POPS FOR MONDAY NIGHT INTO
TUESDAY.
TEMPERATURES WILL REMAIN SOMEWHAT COOLER THAN SEASONAL NORMALS
THROUGHOUT THE FORECAST PERIOD. THUS...WITH HIGHS IN THE LOWER TO
MID 30S MUCH OF THE FORECAST...WE WILL SLOWLY LOSE SNOW COVER IN
PERIODS WE ARE NOT GAINING IT. THIS SEEMS PRETTY TYPICAL FOR LATE
FEBRUARY IN MY EXPERIENCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1203 PM CST FRI FEB 22 2013
AT THIS TIME CONDITIONS ARE MAINLY IFR...WITH VFR VISIBILITIES
FOR KMLI AND KBRL WHERE SNOW HAS ENDED. THIS TREND TO GRADUALLY
SPREAD NORTH WITH VISIBILITIES IMPROVING TO VFR FOR KCID AND KDBQ
IN THE NEXT FEW HOURS. EXPECT THAT IFR CIGS WILL LINGER OVERNIGHT
TONIGHT AND INTO SATURDAY MORNING. PATCHES OF HIGHER CIGS MAY
IMPACT KCID AND KDBQ THIS AFTERNOON...BUT THESE ARE EXPECTED TO BE
TEMPORARY...AND WILL DEFINITELY FILL BACK IN BY 00Z. FOR NOW HAVE
DECIDED TO KEEP AN EYE ON SATELLITE AND IF LARGE ENOUGH WILL PUT
IN A TEMPO GROUP. WINDS TO TURN WEST/SOUTHWEST THIS AFTERNOON AND
REMAIN THROUGH REMAINDER OF FORECAST AT LESS THAN 10KTS. CIGS TO
FINALLY COME TO VFR SATURDAY MORNING. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR IAZ054.
WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR
IAZ040>042-051>053.
IL...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR ILZ001-
002-007.
MO...NONE.
&&
$$
UPDATE...LE
SHORT TERM...08
LONG TERM...ERVIN
AVIATION...LE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1204 PM CST FRI FEB 22 2013
.UPDATE...
ISSUED AT 1203 PM CST FRI FEB 22 2013
HAVE BEEN SENDING SOME UPDATES THIS MORNING FOR
TEMPERATURE...WIND AND PRECIPITATION TRENDS. FORECAST IS GENERALLY
WORKING OUT REASONABLY WELL...BUT WE HAVE ONE LAST BAND OF SNOW
OVER CENTRAL IOWA RIGHT NOW THAT SHOULD ROTATE ACROSS THE
NORTHWEST PORTIONS OF THE FORECAST AREA. THOUGH THIS BAND IS
PRODUCING SOME VISIBILITIES DOWN TO A MILE...THIS SHOULD BE
TEMPORARY ENOUGH THAT DO NOT EXPECT ANY MORE THAN A DUSTING OF
ADDITIONAL ACCUMULATION. WITH THAT SAID...WILL BE EVALUATING
DROPPING SOME COUNTIES OUT OF THE WINTER STORM WARNING HERE IN THE
NEXT HOUR OR SO WHERE THE PRECIPITATION HAS ENDED. ..LE..
&&
.SHORT TERM...TODAY AND TONIGHT
/ISSUED 316 AM CST FRI FEB 22 2013/
RUNNING BEHIND DUE TO OTHER PROBLEMS. FIRST...BASED ON RAP TRENDS
WILL DROP HEADLINES FOR ROUGHLY THE SOUTHERN THIRD. THE OTHER
HEADLINES WILL CONTINUE FOR NOW BUT MAY GET CANCELLED OR MODIFIED
OVER THE NEXT 3-4 HRS.
RAP TRENDS INDICATE THE WAA WING OF SNOW WILL BE IN MN/WI SHORTLY.
FLURRIES OR VERY LIGHT SNOW IS SPORADIC ACROSS THE AREA BUT VERY
LITTLE IN THE WAY OF NEW ACCUMULATION SHOULD BE SEEN THROUGH 12Z.
DURING THE DAY THE RAP DEVELOPS NEW FORCING AS THE OCCLUDED LOW
MOVES UP THROUGH THE FAR WESTERN CWFA WHICH SHOULD INDUCE SOME NEW
LIGHT SNOW DURING THE DAY ACROSS THE AREA. CONDENSATION PRESSURE
DEFICITS WILL SLOWLY RISE SO THERE SHOULD BE A GRADUAL END TO THE
SNOW FROM SOUTH TO NORTH DURING THE DAY.
ADDITIONAL ACCUMULATIONS FOR THE REMAINDER OF THE DAY SHOULD RANGE
FROM A DUSTING TO PERHAPS AN INCH.
TONIGHT...CYCLONIC FLOW SHOULD CONTINUE TO KEEP LIGHT
SNOW/FLURRIES GOING ACROSS ROUGHLY THE NORTH/NORTHEAST THIRD OF
THE CWFA DURING THE EVENING THAT GRADUALLY ENDS DURING THE NIGHT.
BASED ON TEMPERATURES CURRENTLY IN MISSOURI...THE EASTERN CWFA
SHOULD SEE READING GET TO OR JUST ABOVE FREEZING DURING THE
DAYLIGHT HOURS. ..08..
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
/ISSUED 316 AM CST FRI FEB 22 2013/
ANOTHER ACTIVE PERIOD IS LOOMING IN THE LONG TERM...WITH ALL
MODELS SHOWING A DYNAMIC SYSTEM MONDAY THROUGH MID WEEK. THERE IS
PLENTY OF MODEL SPREAD ON TIMING AND TRACK OF THIS SYSTEM...AS
WELL AS ITS EVENTUAL EVOLUTION INTO A MAJOR LONG WAVE TROF.
THUS...FOR NOW...AND WILL FULL SUPPORT OF THIS FORECASTER...WE
WILL TAKE SOME BABY STEPS TOWARD A WINTER EVENT...OF SNOW AND
POTENTIALLY WIND. I AM ENCOURAGED THAT BOTH THE 00Z
ECMWF..UKMET...GEM...AND NAM ALL TAKE THE SYSTEM SOUTH...WITH THE
BEST TRACK FOR HEAVY QPF OVER CWAS JUST SOUTH. NOT THAT THAT WILL
OCCUR...BUT I FEEL THIS WINTER REPRESENT YET ANOTHER YEAR THAT WE
MODELS WILL EVENTUALLY TRACK SYSTEMS A BIT FARTHER NORTH THAN
THEIR DAY 3 TO 7 FORECASTS. THE GFS REMAINS MUCH FARTHER
NORTH...WEAKER...AND FASTER THAN OTHER MODELS...AND IT LARGELY
DISREGARDED EXCEPT FOR INSERTING SOME SLIGHT CHANCE POPS FOR
SUNDAY NIGHT. IN THE END...IT WOULD SEEM SLOWER IS THE WAY TO GO
ON THIS SYSTEM...ESPECIALLY SINCE IT IS ANOTHER CLOSED UPPER LOW
SYNOPTIC SYSTEM. IT TRENDS HOLD TRUE ON THE ECMWF AND OTHERS...WE
ARE CERTAIN TO NEED CATEGORICAL POPS FOR MONDAY NIGHT INTO
TUESDAY.
TEMPERATURES WILL REMAIN SOMEWHAT COOLER THAN SEASONAL NORMALS
THROUGHOUT THE FORECAST PERIOD. THUS...WITH HIGHS IN THE LOWER TO
MID 30S MUCH OF THE FORECAST...WE WILL SLOWLY LOSE SNOW COVER IN
PERIODS WE ARE NOT GAINING IT. THIS SEEMS PRETTY TYPICAL FOR LATE
FEBRUARY IN MY EXPERIENCE.
ERVIN
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1203 PM CST FRI FEB 22 2013
AT THIS TIME CONDITIONS ARE MAINLY IFR...WITH VFR VISIBILITIES
FOR KMLI AND KBRL WHERE SNOW HAS ENDED. THIS TREND TO GRADUALLY
SPREAD NORTH WITH VISIBILITIES IMPROVING TO VFR FOR KCID AND KDBQ
IN THE NEXT FEW HOURS. EXPECT THAT IFR CIGS WILL LINGER OVERNIGHT
TONIGHT AND INTO SATURDAY MORNING. PATCHES OF HIGHER CIGS MAY
IMPACT KCID AND KDBQ THIS AFTERNOON...BUT THESE ARE EXPECTED TO BE
TEMPORARY...AND WILL DEFINITELY FILL BACK IN BY 00Z. FOR NOW HAVE
DECIDED TO KEEP AN EYE ON SATELLITE AND IF LARGE ENOUGH WILL PUT
IN A TEMPO GROUP. WINDS TO TURN WEST/SOUTHWEST THIS AFTERNOON AND
REMAIN THROUGH REMAINDER OF FORECAST AT LESS THAN 10KTS. CIGS TO
FINALLY COME TO VFR SATURDAY MORNING. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR IAZ054-
066-068.
WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR
IAZ040>042-051>053-063>065-067.
IL...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR ILZ001-
002-007-009-015>018-024.
MO...NONE.
&&
$$
UPDATE...LE
SHORT TERM...08
LONG TERM...ERVIN
AVIATION...LE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
533 AM CST FRI FEB 22 2013
.UPDATE...
DATA AT 11Z PLACES THE OCCLUDED LOW BETWEEN KOTM AND KTVK. RAP
MODEL TRENDS MOVE THE OCCLUDED LOW NORTHEAST INTO WISCONSIN BY MID
AFTERNOON. TRIPLE POINT MOVING UP THROUGH THE EASTERN CWFA MAY OR
MAY NOT SEE A WEAK WAVE DEVELOP ALONG IT.
THE CURRENT AREA OF -SN IN THE WESTERN CWFA IS EXPECTED TO
CONTINUE A SLOW DRIFT NORTHEAST AHEAD OF THE OCCLUDED LOW WHICH
SHOULD GENERATE SOME NEW ACCUMULATING AMOUNTS OF POTENTIALLY AN
INCH. IF THE RAP TRENDS ARE CORRECT THIS AREA OF -SN SHOULD EXIT
THE NORTHEAST CWFA EARLY THIS AFTERNOON.
AS FOR HEADLINES...WILL KEEP THEM IN PLACE FOR A FEW MORE HOURS.
HOWEVER...MORE OF THE AREA MAY BE CLEARED EARLY IF WHAT IS BEING
SUGGESTED BY THE RAP IS CORRECT. ..08..
&&
.AVIATION...
RAP MODEL TRENDS INDICATE THE SFC LOW WILL MOVE THROUGH EASTERN
IOWA TOWARD WISCONSIN. A WARM FRONT WILL MOVE THROUGH KBRL/KMLI
HELPING TO TURN WINDS SOUTH BEFORE BECOMING WEST WITH THE LOW
PASSAGE. IFR/MVFR CONDITIONS WILL CONTINUE THROUGH 00Z/23 WITH
POTENTIALLY LOWER VSBYS IN HEAVIER SHSN. AFT 00Z/23 ANY IFR
CONDITIONS WILL IMPROVE TO MVFR. ..08..
&&
.PREV DISCUSSION... /ISSUED 316 AM CST FRI FEB 22 2013/
SYNOPSIS...
06Z SFC ANALYSIS HAS THE OCCLUDED LOW IN WEST CENTRAL MISSOURI
WITH A NEW TRIPLE POINT DEVELOPING JUST WEST OF KSTL. AN INVERTED
TROF RAN FROM THE OCCLUDED LOW INTO WESTERN IOWA. RADAR SHOWS THE
BULK OF THE MAIN SNOW MOVING NORTH INTO MN/WI. HOWEVER...VERY
LIGHT SNOW WAS BEING REPORTED AS FAR SOUTH AS MISSOURI. DEW POINTS
WERE IN THE TEENS AND 20S ACROSS MUCH OF THE MIDWEST WITH 30S AND
HIGHER FROM THE OHIO VALLEY ON SOUTH.
SHORT TERM...TODAY AND TONIGHT
RUNNING BEHIND DUE TO OTHER PROBLEMS. FIRST...BASED ON RAP TRENDS
WILL DROP HEADLINES FOR ROUGHLY THE SOUTHERN THIRD. THE OTHER
HEADLINES WILL CONTINUE FOR NOW BUT MAY GET CANCELLED OR MODIFIED
OVER THE NEXT 3-4 HRS.
RAP TRENDS INDICATE THE WAA WING OF SNOW WILL BE IN MN/WI SHORTLY.
FLURRIES OR VERY LIGHT SNOW IS SPORADIC ACROSS THE AREA BUT VERY
LITTLE IN THE WAY OF NEW ACCUMULATION SHOULD BE SEEN THROUGH 12Z.
DURING THE DAY THE RAP DEVELOPS NEW FORCING AS THE OCCLUDED LOW
MOVES UP THROUGH THE FAR WESTERN CWFA WHICH SHOULD INDUCE SOME NEW
LIGHT SNOW DURING THE DAY ACROSS THE AREA. CONDENSATION PRESSURE
DEFICITS WILL SLOWLY RISE SO THERE SHOULD BE A GRADUAL END TO THE
SNOW FROM SOUTH TO NORTH DURING THE DAY.
ADDITIONAL ACCUMULATIONS FOR THE REMAINDER OF THE DAY SHOULD RANGE
FROM A DUSTING TO PERHAPS AN INCH.
TONIGHT...CYCLONIC FLOW SHOULD CONTINUE TO KEEP LIGHT
SNOW/FLURRIES GOING ACROSS ROUGHLY THE NORTH/NORTHEAST THIRD OF
THE CWFA DURING THE EVENING THAT GRADUALLY ENDS DURING THE NIGHT.
BASED ON TEMPERATURES CURRENTLY IN MISSOURI...THE EASTERN CWFA
SHOULD SEE READING GET TO OR JUST ABOVE FREEZING DURING THE
DAYLIGHT HOURS. ..08..
LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
ANOTHER ACTIVE PERIOD IS LOOMING IN THE LONG TERM...WITH ALL MODELS
SHOWING A DYNAMIC SYSTEM MONDAY THROUGH MID WEEK. THERE IS PLENTY
OF MODEL SPREAD ON TIMING AND TRACK OF THIS SYSTEM...AS WELL AS ITS
EVENTUAL EVOLUTION INTO A MAJOR LONG WAVE TROF. THUS...FOR NOW...AND
WILL FULL SUPPORT OF THIS FORECASTER...WE WILL TAKE SOME BABY STEPS
TOWARD A WINTER EVENT...OF SNOW AND POTENTIALLY WIND. I AM
ENCOURAGED THAT BOTH THE 00Z ECMWF..UKMET...GEM...AND NAM ALL TAKE
THE SYSTEM SOUTH...WITH THE BEST TRACK FOR HEAVY QPF OVER CWAS JUST
SOUTH. NOT THAT THAT WILL OCCUR...BUT I FEEL THIS WINTER REPRESENT
YET ANOTHER YEAR THAT WE MODELS WILL EVENTUALLY TRACK SYSTEMS A BIT
FARTHER NORTH THAN THEIR DAY 3 TO 7 FORECASTS. THE GFS REMAINS MUCH
FARTHER NORTH...WEAKER...AND FASTER THAN OTHER MODELS...AND IT
LARGELY DISREGARDED EXCEPT FOR INSERTING SOME SLIGHT CHANCE POPS FOR
SUNDAY NIGHT. IN THE END...IT WOULD SEEM SLOWER IS THE WAY TO GO ON
THIS SYSTEM...ESPECIALLY SINCE IT IS ANOTHER CLOSED UPPER LOW
SYNOPTIC SYSTEM. IT TRENDS HOLD TRUE ON THE ECMWF AND OTHERS...WE
ARE CERTAIN TO NEED CATEGORICAL POPS FOR MONDAY NIGHT INTO TUESDAY.
TEMPERATURES WILL REMAIN SOMEWHAT COOLER THAN SEASONAL NORMALS
THROUGHOUT THE FORECAST PERIOD. THUS...WITH HIGHS IN THE LOWER TO
MID 30S MUCH OF THE FORECAST...WE WILL SLOWLY LOSE SNOW COVER IN
PERIODS WE ARE NOT GAINING IT. THIS SEEMS PRETTY TYPICAL FOR LATE
FEBRUARY IN MY EXPERIENCE.
ERVIN
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR
CLINTON-JACKSON-SCOTT.
WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR BENTON-
BUCHANAN-CEDAR-DELAWARE-DUBUQUE-IOWA-JOHNSON-JONES-LINN-
MUSCATINE.
IL...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR BUREAU-
CARROLL-HENRY IL-JO DAVIESS-MERCER-PUTNAM-ROCK ISLAND-
STEPHENSON-WHITESIDE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
316 AM CST FRI FEB 22 2013
.SYNOPSIS...
06Z SFC ANALYSIS HAS THE OCCLUDED LOW IN WEST CENTRAL MISSOURI
WITH A NEW TRIPLE POINT DEVELOPING JUST WEST OF KSTL. AN INVERTED
TROF RAN FROM THE OCCLUDED LOW INTO WESTERN IOWA. RADAR SHOWS THE
BULK OF THE MAIN SNOW MOVING NORTH INTO MN/WI. HOWEVER...VERY
LIGHT SNOW WAS BEING REPORTED AS FAR SOUTH AS MISSOURI. DEW POINTS
WERE IN THE TEENS AND 20S ACROSS MUCH OF THE MIDWEST WITH 30S AND
HIGHER FROM THE OHIO VALLEY ON SOUTH.
&&
.SHORT TERM...TODAY AND TONIGHT
RUNNING BEHIND DUE TO OTHER PROBLEMS. FIRST...BASED ON RAP TRENDS
WILL DROP HEADLINES FOR ROUGHLY THE SOUTHERN THIRD. THE OTHER
HEADLINES WILL CONTINUE FOR NOW BUT MAY GET CANCELLED OR MODIFIED
OVER THE NEXT 3-4 HRS.
RAP TRENDS INDICATE THE WAA WING OF SNOW WILL BE IN MN/WI SHORTLY.
FLURRIES OR VERY LIGHT SNOW IS SPORADIC ACROSS THE AREA BUT VERY
LITTLE IN THE WAY OF NEW ACCUMULATION SHOULD BE SEEN THROUGH 12Z.
DURING THE DAY THE RAP DEVELOPS NEW FORCING AS THE OCCLUDED LOW
MOVES UP THROUGH THE FAR WESTERN CWFA WHICH SHOULD INDUCE SOME NEW
LIGHT SNOW DURING THE DAY ACROSS THE AREA. CONDENSATION PRESSURE
DEFICITS WILL SLOWLY RISE SO THERE SHOULD BE A GRADUAL END TO THE
SNOW FROM SOUTH TO NORTH DURING THE DAY.
ADDITIONAL ACCUMULATIONS FOR THE REMAINDER OF THE DAY SHOULD RANGE
FROM A DUSTING TO PERHAPS AN INCH.
TONIGHT...CYCLONIC FLOW SHOULD CONTINUE TO KEEP LIGHT
SNOW/FLURRIES GOING ACROSS ROUGHLY THE NORTH/NORTHEAST THIRD OF
THE CWFA DURING THE EVENING THAT GRADUALLY ENDS DURING THE NIGHT.
BASED ON TEMPERATURES CURRENTLY IN MISSOURI...THE EASTERN CWFA
SHOULD SEE READING GET TO OR JUST ABOVE FREEZING DURING THE
DAYLIGHT HOURS. ..08..
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
ANOTHER ACTIVE PERIOD IS LOOMING IN THE LONG TERM...WITH ALL MODELS
SHOWING A DYNAMIC SYSTEM MONDAY THROUGH MID WEEK. THERE IS PLENTY
OF MODEL SPREAD ON TIMING AND TRACK OF THIS SYSTEM...AS WELL AS ITS
EVENTUAL EVOLUTION INTO A MAJOR LONG WAVE TROF. THUS...FOR NOW...AND
WILL FULL SUPPORT OF THIS FORECASTER...WE WILL TAKE SOME BABY STEPS
TOWARD A WINTER EVENT...OF SNOW AND POTENTIALLY WIND. I AM
ENCOURAGED THAT BOTH THE 00Z ECMWF..UKMET...GEM...AND NAM ALL TAKE
THE SYSTEM SOUTH...WITH THE BEST TRACK FOR HEAVY QPF OVER CWAS JUST
SOUTH. NOT THAT THAT WILL OCCUR...BUT I FEEL THIS WINTER REPRESENT
YET ANOTHER YEAR THAT WE MODELS WILL EVENTUALLY TRACK SYSTEMS A BIT
FARTHER NORTH THAN THEIR DAY 3 TO 7 FORECASTS. THE GFS REMAINS MUCH
FARTHER NORTH...WEAKER...AND FASTER THAN OTHER MODELS...AND IT
LARGELY DISREGARDED EXCEPT FOR INSERTING SOME SLIGHT CHANCE POPS FOR
SUNDAY NIGHT. IN THE END...IT WOULD SEEM SLOWER IS THE WAY TO GO ON
THIS SYSTEM...ESPECIALLY SINCE IT IS ANOTHER CLOSED UPPER LOW
SYNOPTIC SYSTEM. IT TRENDS HOLD TRUE ON THE ECMWF AND OTHERS...WE
ARE CERTAIN TO NEED CATEGORICAL POPS FOR MONDAY NIGHT INTO TUESDAY.
TEMPERATURES WILL REMAIN SOMEWHAT COOLER THAN SEASONAL NORMALS
THROUGHOUT THE FORECAST PERIOD. THUS...WITH HIGHS IN THE LOWER TO
MID 30S MUCH OF THE FORECAST...WE WILL SLOWLY LOSE SNOW COVER IN
PERIODS WE ARE NOT GAINING IT. THIS SEEMS PRETTY TYPICAL FOR LATE
FEBRUARY IN MY EXPERIENCE.
ERVIN
&&
.AVIATION... /ISSUED 1129 PM CST THU FEB 21 2013/
(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1121 PM CST THU FEB 21 2013
LOW PRESSURE OVER MISSOURI WILL LIFT NORTHEAST INTO WISCONSIN BY
EARLY FRIDAY EVENING. MODERATE TO HEAVY SNOW OVER THE FORECAST
AREA AND NORTH OF THE SURFACE LOW WILL LIFT NORTH EARLY THIS
MORNING WITH LINGERING LIGHT SNOWS CONTINUING INTO FRIDAY MORNING.
THE LIGHT SNOW WILL END FROM SOUTH TO NORTH BY FRIDAY AFTERNOON.
IFR TO LIFR CONDITIONS ARE EXPECTED DURING THE OVERNIGHT HOURS
WITH THE LIFR CONDITIONS MOVING OUT OF THE AREA WITH THE BAND OF
HEAVIER SNOWS. STRONG EAST WINDS WILL GRADUALLY DIMINISH EARLY
FRIDAY MORNING AND TURN TO THE WEST LATE FRIDAY MORNING AS THE
LOW MOVES TO THE NORTHEAST OF THE FORECAST AREA. THE WEST WINDS
WILL PULL IN SOME DRIER AIR CAUSING VISIBILITIES AND CIGS TO
IMPROVE TO MVFR FRIDAY AFTERNOON AND EVENING.
DLF
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR
CLINTON-JACKSON-SCOTT.
WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR BENTON-
BUCHANAN-CEDAR-DELAWARE-DUBUQUE-IOWA-JOHNSON-JONES-LINN-
MUSCATINE.
IL...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR BUREAU-
CARROLL-HENRY IL-JO DAVIESS-MERCER-PUTNAM-ROCK ISLAND-
STEPHENSON-WHITESIDE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1142 PM CST THU FEB 21 2013
.UPDATE...
HAVE LOWERED SNOW AMOUNTS WITH THE EVENING UPDATE. DSM RAP PROFILES
SHOW PLENTY OF MOISTURE UP TO AT LEAST 17KFT...BUT WITH ONLY A VERY
NARROW LAYER OF LIFT IN THE DENDRITIC GROWTH ZONE /DGZ/ NEAR THE TOP
OF THAT MOISTURE LAYER. THIS HAS RESULTED IN MUCH OF THAT UPWARD
VERTICAL MOTION IN TEMPS WARMER THAN -12C AND NON-DENDRITIC SNOW
CRYSTALS THAT HAVE NOT ACCUMULATED MUCH...AT LEAST IN WIDESPREAD
FASHION. HIGHEST TOTALS HAVE FALLEN SOUTH AND WEST OF DSM METRO
AREA. RAP INDICATES ANOTHER FINAL SURGE OF LIFT IN THE DGZ WITH THE
NW-SE ORIENTED RADAR BAND AND COOLER CLOUD TOPS MOVING THROUGH SRN
IA RIGHT NOW. LIGHT SNOW OR FLURRIES ARE THEN EXPECTED TO LINGER
INTO FRIDAY MORNING WITH GENERAL AMOUNTS NOW 4-6 INCHES. EVEN THIS
MAY BE TOO MUCH...BUT DO NOT WANT TO GET TOO AGGRESSIVE TRIMMING
AMOUNTS. WITH BORDERLINE AMOUNTS UP TO 6 INCHES...WILL ALSO LEAVE
WARNING IN PLACE. NOTHING TO GAIN BY DOWNGRADING AT THIS POINT.
&&
.SHORT TERM /TONIGHT/...
SNOW BAND ADVECTING NORTHWARD ACROSS MUCH OF THE FORECAST AREA THIS
AFTERNOON INTO THE EVENING CAUSING RAPIDLY DETERIORATING CONDITIONS.
MODELS REMAIN IN GREAT AGREEMENT WITH TIMING AND PLACEMENT OF
HEAVIEST BAND TONIGHT AND WITH THE UPPER LOW TRACK DURING THE
OVERNIGHT HOURS. LEANED TOWARD THE TIMING OF NAM12/HRRR/HIRES
ARW-WRF FOR BAND DURING THE EVENING HOURS AND SREF/NAM OVERNIGHT.
IMPRESSIVE ISENTROPIC LIFT AHEAD OF THE UPPER LOW...GENERALLY ALONG
THE 285K TO 305K ISENTROPIC SURFACES...COMBINED WITH GOOD MOISTURE
TRANSPORT WILL CONTINUE TO PUSH THE CURRENT SNOW BAND FURTHER NORTH
LATE THIS AFTERNOON AND EVENING. THE ISENTROPIC LIFT DIMINISHES IN
STRENGTH AS THE UPPER LOW APPROACHES FROM KANSAS LATER TONIGHT INTO
THE OVERNIGHT HOURS BUT ENOUGH DEEP FORCING ASSOCIATED WITH IT AS IT
PASSES THROUGH THE STATE TO KEEP HIGH POPS GOING OVERNIGHT.
ALSO...EXPECTING THE SNOW TO CONTINUE TO FILL IN ACROSS SOUTHWEST
IOWA AND REMAIN FAIRLY PERSISTENT ACROSS THE FORECAST AREA FOR
SEVERAL HOURS TONIGHT. RAP CONFIRMS THIS AS IT HAS MAX OMEGA WITHIN
THE DENDRITIC LAYER PERSISTING THROUGH 02Z AT DSM...AND THROUGH 06Z
ACROSS NORTH CENTRAL IOWA. EVEN WITH SNOW INTENSITIES
DIMINISHING...STILL EXPECTING LIGHTER SNOWFALL ACCUMULATIONS B/T 06Z
AND 12Z FRIDAY WITH PASSAGE OF THE UPPER LOW. LEANED TOWARD A BLEND
OF THE GFS/NAM FOR QPF AMOUNTS AND STILL ON TRACK FOR GOOD SWATH OF
6 TO 9 INCHES GENERALLY SOUTH OF HIGHWAY 20. SLIGHTLY LESS FURTHER
NORTH AS THE BEST FORCING SKIRTS TO ITS SOUTHEAST.
SHARP PRESSURE GRADIENT ACROSS THE STATE KEEPS EAST TO NORTHEAST
WINDS GUSTS THROUGH 03-06Z TONIGHT BEFORE DIMINISHING. 925MB WINDS
AT 03Z STILL GUSTING AT 30KTS OVER CENTRAL PORTION OF THE FORECAST
AREA. VISIBILITY RAPIDLY DIMINISHING WITH THE ONSET OF THE SNOW AND
WILL PERSIST BEFORE THE WINDS WEAKEN LATER THIS EVENING.
.LONG TERM /FRIDAY THROUGH THURSDAY/...
UPPER LOW WILL BE DEPARTING TO THE NORTHEAST ON FRIDAY WITH FORCING
SUBSIDING THROUGH THE DAY. HAVE CONTINUED CATEGORICAL WORDING IN
THE FAR NORTHEAST DURING THE MORNING WITH A DECENT GRADIENT TO
ESSENTIALLY NO PCPN IN FAR SOUTHWEST. SUBSIDENCE WILL CONTINUE TO
OVERSPREAD THE AREA DURING THE DAY AND HAVE CUT THE POPS OFF ACROSS
THE SOUTH BY AFTERNOON AND LEFT SCATTERED SNOW SHOWERS AND FLURRIES
IN THE NORTH UNDER THE UPPER LOW WHERE SOME WEAK LIFT WILL CONTINUE
TO RESIDE. THE THREAT OF ANY PCPN WILL END BY SATURDAY NIGHT IN THE
NORTH AS THE SYSTEM PULLS AWAY. THE 850MB THERMAL TROF IS NEARLY
ASSOCIATED WITH THE UPPER LOW SO WARM ADVECTION WILL COMMENCE
IMMEDIATELY ON FRIDAY NIGHT INTO SATURDAY ON BACKSIDE OF THE SYSTEM.
THIS WILL KEEP TEMPERATURES FROM DROPPING AS MUCH AS WOULD BE
EXPECTED WITH FRESH SNOW COVER WITH HIGHS ON SUNDAY APPROACHING OR
SLIGHTLY ABOVE FREEZING.
FOCUS WILL THEN SHIFT ON SHORTWAVE DROPPING INTO THE ROCKIES DURING
THE WEEKEND. GFS IS FARTHER NORTH AND FASTER WITH THE EVOLUTION OF
THIS SYSTEM AND APPEARS TO BE THE ODD MODEL OUT. THE EURO AND GEM
HAVE BEEN MORE CONSISTENT DIGGING THE SYSTEM THROUGH THE
INTERMOUNTAIN WEST THEN MOVING THE STORM EASTWARD THROUGH THE MID
MISSISSIPPI RIVER VALLEY. THE IMPLICATIONS OF THIS WOULD BE TO KEEP
THE BULK OF FORCING AND MOISTURE TO OUR SOUTH WITH MISSOURI SEEING
THE WORST CONDITIONS. HOWEVER...SOME WEAKER FORCING WILL BLEED INTO
THE STATE AS THE UPPER TROF IS ELONGATED FROM THE CENTRAL INTO THE
NORTHERN PLAINS. THEREFORE...SOME SNOWFALL IS STILL EXPECTED ACROSS
THE STATE FROM LATE SUNDAY NIGHT INTO TUESDAY MORNING...PRIMARILY
IMPACTING THE SOUTHERN HALF OF IOWA. SOME LIGHT TO MODERATE
ACCUMULATIONS ARE EXPECTED WITH THIS STORM AND WILL CONTINUE TO
MONITOR THE TRACK SINCE ANY NORTHWARD SHIFT WOULD BEGIN TO BRING
SIGNIFICANTLY HIGHER AMOUNTS INTO THE STATE. AFTER THIS SYSTEM
PULLS AWAY...DRIER CONDITIONS ARE EXPECTED WITH TEMPERATURES BELOW
NORMAL WITH COOL NORTHERLY FLOW BEHIND THE SYSTEM.
&&
.AVIATION...22/06Z
NARROW BAND OF LIFR SNOW JUST EXITING KDSM/KOTM WILL MOVE THROUGH
KFOD SHORTLY. AT LEAST IFR CONDITIONS WILL ALSO AFFECT KMCW/KALO
FOR SEVERAL HOURS EARLY FRI AS WELL AS LAST BAND OF HEAVIER SNOW
MOVES NORTHWARD. THIS WILL BE FOLLOWED BY MVFR/IFR CIGS UPSTREAM
INTO KS AND MO...ALONG WITH LIGHT SNOW AND FLURRIES THROUGH AT LEAST
FRI MORNING. MODELS SUGGEST STRATUS WILL PERSIST THROUGH MUCH OF
THE PERIOD AS WELL...ALTHOUGH CONFIDENCE IN MVFR OR IFR IS LOW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST FRIDAY FOR
ADAIR-ADAMS-APPANOOSE-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CLARKE-
CRAWFORD-DALLAS-DAVIS-DECATUR-GREENE-GUTHRIE-JASPER-LUCAS-MADISON-
MAHASKA-MARION-MONROE-POLK-POWESHIEK-RINGGOLD-SAC-STORY-TAYLOR-UNION-
WAPELLO-WARREN-WAYNE-BLACK HAWK-BREMER-BUTLER-CERRO GORDO-EMMET-
FRANKLIN-GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-MARSHALL-
PALO ALTO-POCAHONTAS-TAMA-WEBSTER-WINNEBAGO-WORTH-WRIGHT.
&&
$$
UPDATE/AVIATION...SMALL
SHORT TERM...KLP
LONG TERM...COGIL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1129 PM CST THU FEB 21 2013
...UPDATE TO AVIATION...
.DISCUSSION...
TONIGHT THROUGH FRIDAY...
THE UPPER LEVEL LOW WAS LOCATED ACROSS THE NORTHEAST TEXAS PANHANDLE
THIS AFTERNOON. ONE 1.5PV ANOMALY WAS LIFTING NORTHWARD ACROSS WEST
CENTRAL KS...WITH A SECOND 1.5PV ANOMALY OVER WESTERN OK. THE
SHORT-TERM MODELS...HRRR AND RAP SHOW THE 1.5PV ANOMALY
LIFTING NORTHEAST ACROSS EASTERN KS. AHEAD OF THE 1.5PV ANOMALY THE
FRONTOGENETICAL FORCING SHOULD INCREASE TO PROVIDE A PERIOD OF LIGHT
SNOW. THE MODELS SHOW AN INCREASE IN THE NEGATIVE SATURATED
EPV...CSI...WHICH COULD CAUSE SOME SLIGHTLY HEAVIER SNOW
BANDS...THUS THE WESTERN AND CENTRAL COUNTIES OF THE CWA COULD SEE
SOME LOCALLY HIGHER SNOW AMOUNTS.
UNTIL THE DENDRITIC GROWTH ZONE SATURATES LATER THIS AFTERNOON
THERE MAY BE PERIODS OF FREEZING DRIZZLE ACROSS THE EASTERN HALF OF
THE CWA. THE PATCHY FREEZING DRIZZLE MAY REFORM LATER THIS EVENING
ONCE THE STRONGER ASCENT SHIFTS NORTHEAST OF THE CWA. ISENTROPIC
DOWN GLIDE SHOULD BRING AN END THE THE FREEZING DRIZZLE CHANCE AFTER
MIDNIGHT.
THE STORM TOTAL SNOWFALL WILL RANGE FROM 6 TO 15 INCHES WITH SOME
LOCALLY HIGHER AMOUNTS.
I WILL KEEP THE WINTER STORM WARNING IN EFFECT UNTIL 00Z FOR THE
WESTERN HALF OF THE CWA AND UNTIL MIDNIGHT FOR THE EASTERN HALF OF
THE CWA.
FRIDAY...THE SKIES SHOULD BEGIN TO CLEAR FROM WEST TO EAST ACROSS
THE CWA THROUGH THE MID AND LATE MORNING HOURS. HIGHS WILL CONTINUE
TO BE COLD WITH MID 20S...GIVEN SEVERAL INCHES OF SNOW COVER.
GARGAN
FRIDAY NIGHT THROUGH THURSDAY...
DRY CONDITIONS ARE EXPECTED FOR THE START OF THE WEEKEND AS THE
UPPER LEVEL TROUGH THAT IMPACTED THE REGION WITH WINTER WEATHER
TODAY SLIDES NORTH TOWARD THE GREAT LAKES REGION. SURFACE HIGH
PRESSURE BRIEFLY WILL SETTLE INTO THE REGION BEHIND THE EXITING
STORM SYSTEM BEFORE THE NEXT UPPER LEVEL TROUGH BEGINS TO DIG
SOUTHWARD ACROSS THE NORTHERN AND CENTRAL PLAINS DURING THE LATTER
PART OF THE WEEKEND. THERE IS STILL UNCERTAINTY AMONGST THE MODELS
REGARDING JUST HOW FAR SOUTH THIS TROUGH WILL DIG ALONG AND EAST OF
THE ROCKY MOUNTAINS AND HOW QUICKLY THE UPPER LOW EJECTS
NORTHEASTWARD ACROSS THE FORECAST AREA AND FURTHER EAST OF THE AREA.
THESE MODEL DISCREPANCIES LEAD TO DIFFICULTIES IN PINNING DOWN THE
TIMING OF ANY PRECIPITATION FROM THIS SYSTEM. MODELS SEEM TO BE A
BIT SLOWER IN BRINGING THE SYSTEM INTO THE AREA...SO HAVE DECREASED
POPS FOR SUNDAY WITH CHANCE POPS FOR THE SUNDAY NIGHT THROUGH MONDAY
NIGHT TIME FRAME. THESE POPS BEST REFLECT A BLEND OF THE ECMWF/GEM.
THE GFS CURRENTLY IS AN OUTLIER IN KEEPING THE UPPER TROUGH FURTHER
NORTH AND ONLY HAVING PRECIPITATION SKIMMING ACROSS THE NORTHERN
PORTION OF THE FORECAST AREA. DEPENDING UPON THE TIMING OF
PRECIPITATION...THE REGION COULD SEE A COMBINATION OF RAIN AND SNOW
SHOWERS WITH THIS SYSTEM. AT THIS TIME...THE SYSTEM LOOKS TO EXIT
EAST OF THE AREA BY TUESDAY. A WEAK RIDGE WILL MOVE INTO THE REGION
BEHIND THIS TROUGH WITH DRY CONDITIONS EXPECTED FOR MID-WEEK. BY THE
END OF THE PERIOD MODEL DISCREPANCIES EXIST WITH REGARDS TO THE NEXT
SHORTWAVE THAT EJECTS INTO THE CENTRAL PLAINS. KEPT ANY MENTION OF
PRECIPITATION OUT OF THE FORECAST AT THIS TIME.
TEMPERATURE FORECASTS FOR THE PERIOD HAVE BEEN COMPLICATED BY THE
SEVERAL INCHES OF SNOW RECEIVED ACROSS THE FORECAST AREA FROM
TODAY`S STORM. WITH THIS IN MIND...HAVE TRENDED WITH TEMPERATURES
STAYING BELOW THE SEASONAL NORMALS THROUGH THE EXTENDED FORECAST
PERIOD...WITH HIGHS GENERALLY IN THE 30S. THE COLDEST NIGHT LOOKS TO
BE FRIDAY NIGHT/EARLY SATURDAY MORNING AS LOW TEMPERATURES PLUMMET
INTO THE SINGLE DIGITS...WITH WIND CHILL VALUES ANYWHERE FROM ZERO
TO 8 BELOW ZERO. OTHERWISE...LOWS GENERALLY LOOK TO BE IN THE TEENS
AND 20S. TEMPERATURE FORECASTS WILL NEED TO BE ADJUSTED DEPENDING
UPON ANY MELTING OF SNOW THAT OCCURS IN THE UPCOMING DAYS.
ACH
&&
.AVIATION...
SNOW SHOWERS COMING TO AN END ACROSS THE AREA. EXPECT FLURRIES TO
HOLD ON FOR A COUPLE MORE HOURS BEFORE MOVING OUT OF THE AREA.
KMHK CURRENTLY SHOWS A VFR OB...HOWEVER GIVEN SEVERAL OBS IN THE
AREA WITH CIGS AROUND 1500 FEET HAVE INTRODUCED A TEMPO FOR MVFR
CIGS AT KMHK. VFR CIGS LOOK TO MOVE INTO THE AREA AROUND 10-12Z AT
ALL TERMINALS JUDGING BY OBSERVATIONS AND TIME OF ARRIVAL TOOL OF
HIGHER CIGS. WILL AMEND AS NECESSARY TO ADJUST TIMING.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
409 PM EST FRI FEB 22 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD INTO THE AREA TONIGHT. A WEAK
COLD FRONT WILL MOVE ACROSS THE AREA ON SATURDAY...FOLLOWED BY
BUILDING HIGH PRESSURE SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED 500MB LOW
CENTERED ACROSS THE UPPER MIDWEST. AT THE SURFACE...AN OCCLUDED FRONT
EXTENDS FROM THE LOW IN THE TN VALLEY. FROM THE OCCLUDED FRONT...A
WARM EXTENDS EASTWARD INTO NORTH-CENTRAL WV. WITH A DRY LAYER IN
PLACE ABOVE 800MB...ANY LINGERING PRECIPITATION IN WEAK LIFT AHEAD
OF THE FRONT HAS BEEN IN THE FORM OF DRIZZLE OR FREEZING DRIZZLE
ACROSS THE AREA. LOCATIONS NORTH OF PITTSBURGH AND ACROSS THE
LAUREL HIGHLANDS/ALLEGHENY FRONT REMAIN BELOW FREEZING.
TONIGHT...LOW-LEVEL MOISTURE WILL LINGER ACROSS THE AREA NORTH AND
EAST OF PITTSBURGH AS A COLD FRONT APPROACHES FROM THE WEST.
RAP/GFS/NAM SOUNDINGS CONTINUE TO INDICATE A DRY DENDRITIC
GROWTH ZONE WITH A SATURATED LAYER FROM 800MB TO THE SURFACE.
THUS...HAVE CONTINUED MENTIONING OF DZ/FZDZ FOR LOCATIONS NORTH AND
EAST OF PITTSBURGH. TEMPS WILL BE FAIRLY STEADY
OVERNIGHT...RANGING FROM THE LOWER 30S NORTH AND EAST OF
PITTSBURGH TO THE UPPER 30S IN PORTIONS OF EASTERN OHIO AND NORTH-
CENTRAL WV.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
A MODEL CONSENSUS INDICATES THAT THE UPPER LOW WILL SHIFT
NORTHEASTWARD INTO THE NORTHERN GREAT LAKES AND A WEAK COLD FRONT
WILL SWING ACROSS THE OHIO VALLEY ON SATURDAY. MEANWHILE...A
SURFACE LOW WILL MOVE FROM THE SOUTHEAST INTO THE MID-
ATLANTIC...PASSING TO THE SOUTHEAST OF THE FORECAST AREA.
DESPITE MODEL AGREEMENT IN THE SYNOPTIC SCALE PATTERN...THERE
STILL LIES SOME UNCERTAINTY IN RESOLVING PRECIPITATION WITH THE
FRONTAL PASSAGE ON SATURDAY.
HAVE ONLY GONE WITH SCHC IN WESTERN PA AND CHC ACROSS THE RIDGES
ON SATURDAY AS THE WEAK FRONT MAY BE ABLE TO PRODUCE A FEW SHOWERS
WHEN IT ENCOUNTERS A BIT MORE AVAILABLE MOISTURE IN WESTERN PA AND
NORTHERN WV. OTHERWISE...WENT DRY IN OHIO. FOR PRECIP
TYPE...MOSTLY RAIN IS FORECAST AS WAA CONTINUES AHEAD OF THE FRONT.
THERE IS STILL SOME UNCERTAINTY AS TO WHETHER COLDER AIR TRAPPED
AT THE SURFACE WILL REMAIN IN PLACE NORTH OF PITTSBURGH AND ACROSS
THE RIDGES...SO HAVE THE MENTION OF SCHC OR CHC FZRA THERE. FOR
TEMPS...SIDED WITH THE WARMER MAV...WITH HIGHS RANGING FROM THE
LOWER TO MID 40S ACROSS MUCH OF THE AREA.
SATURDAY NIGHT THROUGH MONDAY...THE FRONT WILL PASS EAST OF THE
AREA SAT NIGHT WITH THE UPPER LEVEL LOW PASSING NORTH OF THE AREA
ON SUNDAY. HIGH PRESSURE WILL THEN BUILD IN FROM THE SOUTHWEST
SUNDAY NIGHT INTO MONDAY. IN A CYCLONIC MID-LEVEL FLOW SAT NIGHT THAT
WILL BECOME MORE NORTHWESTERLY ON SUN...HAVE CHC POPS ACROSS THE
I-80 CORRIDOR AND WITH UPSLOPING FOR THE LAUREL
HIGHLANDS/ALLEGHENY FRONT. A DRY FORECAST IS IN PLACE SUN NIGHT
INTO MONDAY AS THE HIGH MOVES OVER THE REGION. TEMPS WILL BE A FEW
DEGREES BELOW NORMAL IN THE WAKE OF THE FRONT ON SUNDAY BEFORE
MODERATING TO 5 TO 10 DEGREES ABOVE NORMAL ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
H5 RDG AXIS WILL MOVE ACRS RGN MON NGT IN ADVC OF A STRONG CLOSED
UPR LOW OVER THE SRN PLNS. AS THE WAVE APRCHS LATE MON NGT...WARM
AIR ADVCTN WILL DVLP IN EARNEST...PROVIDING SGFNT MSTR FOR WDSPRD
PCPN. LGT PCPN XPCD TO SPREAD NEWD LATE MON NGT.
CVRG OF PCPN WILL INCR ON TUE AS THE NEGATIVELY-TILTED WAVE
CROSSES THE RGN. GIVEN CONSISTENT FCST AMONG THE MODELS AND
PERSISTENT MEXMOS PCPN SIGNAL ON TUE...CATEGORICAL POPS WERE
INCLUDED ALL ZONES ON TUE. DRY SLOT XPCD TO BRING END TO PCPN TUE
NGT.
EXACT EVOLUTION OF UPR AIR PATTERN THEREAFTER IS LESS CERTAIN...
BUT H5 TROF XPCD TO RMN OVER ERN CONUS. RESULT WILL BE PERSISTENT
COLDER AIR AND OCNL SNOW SHWRS AS WLY-NWLY LOW-LVL FLOW DOMINATES
THE RGN.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MEDIUM...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
LOW TO MEDIUM CONFIDENCE FORECAST.
AREA OF FZRA CONTINUES TO EXIT QUICKLY WITH PATCHY DRIZZLE AND
FREEZING DRIZZLE IN ITS WAKE. BRIEF IFR WX WILL LAST AT PIT METRO
TERMINALS AND FKL/DUJ THRU 20Z. DRY SLOT THAT IS RACING NE FROM
SERN OH AND WV PER LOW LEVEL DOWNSLOPE WINDS AND SW FLOW ALOFT
REACHES ZZV - PIT - LBE THIS AFTN. BKN VFR CIGS WILL CARRY THROUGH
THE EVENING HOURS AT THE AFOREMENTIONED AIRPORTS.
HARDEST PART OF THE FORECAST IS WHAT WILL HAPPEN OVERNIGHT. ALL OF
THE STATISTICAL GUIDANCE YIELDS MVFR / IFR CIGS WHILE UPSTREAM OBS
SAY IT WILL BE VFR. PLAYED THE OPTIMISTIC ROLE FOR MOST
TERMINALS...SAVE FOR FKL/DUJ/ZZV WHERE MVFR CIGS SHOULD OCCUR FOR AT
LEAST PART OF THE NIGHT. ANY MVFR CIGS LIFT BY MID MRNG DUE TO
LIGHT SW WINDS.
WHERE TAFS COULD GO WRONG:
- MVFR CIGS COULD LINGER THROUGH THE AFTN
- MVFR/IFR CIGS MAY DEVELOP DURING THE OVERNIGHT HOURS AREA WIDE
- MVFR CIGS COULD TAKE UNTIL 15-17Z TO LIFT
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
IFR WEATHER IS POSSIBLE MONDAY NIGHT INTO TUESDAY WITH THE NEXT
WEATHER SYSTEM.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MDZ001.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
PAZ007>009-015-016-022-023.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
SHORT TERM...WOODRUM
LONG TERM...KRAMAR
AVIATION...98
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
322 PM EST FRI FEB 22 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA TODAY WITH A LIGHT
WINTRY MIX MOSTLY COMING TO AN END THIS AFTERNOON AND LINGERING
DRIZZLE CONTINUING INTO THE EVENING. A WEAK COLD FRONT WILL MOVE
THROUGH SATURDAY...FOLLOWED BY BUILDING HIGH PRESSURE SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AN UPDATE HAS BEEN ISSUED TO CANCEL THE WINTER WEATHER ADVISORY
FOR THE PITTSBURGH METRO AND FOR ALL OF THE RIDGE ZONES EXCEPT FOR
GARRETT COUNTY. COLD AIR REMAINS DAMMED WITH FREEZING DRIZZLE
ONGOING IN GARRETT CO.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED 500MB LOW
CENTERED ACROSS IOWA. AT THE SURFACE...AN OCCLUDED FRONT EXTENDS
FROM THE LOW IN THE TN VALLEY. FROM THE OCCLUDED FRONT...A WARM
EXTENDS EASTWARD ACROSS CENTRAL WV. 280-300K LAYER ISENTROPIC LIFT
IS PROVIDING FORCING FOR SCATTERED AREAS OF FREEZING RAIN NORTH OF
THE WARM FRONT THIS MORNING FOR LOCATIONS PRIMARILY NORTHEAST OF
A FRANKLIN-CLARION-INDIANA LINE.
THIS AFTERNOON...THE WARM FRONT WILL CONTINUE TO LIFT NORTHWARD
INTO THE UPPER OHIO VALLEY WITH THE AREA OF ISENTROPIC LIFT LIFTING
NORTHEAST OF THE AREA AND BRINGING MEASURABLE MIXED PRECIPITATION
TO AN END. MODEL SOUNDINGS INDICATE THAT DRY AIR ABOVE 800MB WILL
PREVENT ANY DENDRITIC GROWTH INTO THE AFTERNOON...WITH THE LOWER
LEVELS REMAINING SATURATED. THUS...THIS SOUNDING ALLOWS FOR A
DRIZZLE/FREEZING DRIZZLE SCENARIO.
HIGH TEMPS TODAY ARE A FEW DEGREES COOLER THAN LAMP GUIDANCE...RANGING
FROM THE LOWER 30S ACROSS THE I-80 CORRIDOR AND LAUREL
HIGHLANDS/ALLEGHENY FRONT TO MID 40S IN PORTIONS OF EASTERN OHIO
AND NORTH-CENTRAL WV.
TONIGHT...LOW-LEVEL MOISTURE WILL LINGER ACROSS THE AREA NORTH AND
EAST OF PITTSBURGH AS A COLD FRONT APPROACHES FROM THE WEST.
RAP/GFS/NAM SOUNDINGS CONTINUE TO INDICATE A DRY DENDRITIC
GROWTH ZONE WITH A SATURATED LAYER FROM 800MB TO THE SURFACE.
THUS...HAVE CONTINUED MENTIONING OF DZ/FZDZ FOR LOCATIONS NORTH AND
EAST OF PITTSBURGH. TEMPS WILL BE FAIRLY STEADY
OVERNIGHT...RANGING FROM THE LOWER 30S NORTH AND EAST OF
PITTSBURGH TO THE UPPER 30S IN PORTIONS OF EASTERN OHIO AND NORTH-
CENTRAL WV.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
GFS TRIES TO BRING IN PCPN WITH A DVLPG COASTAL LOW ACRS THE
RIDGES SAT. NAM/ECMWF KEEP IT FURTHER E. PREFER THE DRIER SOLNS
GIVEN SE DOWNSLOPING WNDS...AND WITH DVLPG SFC LOW CENTER SO FAR E
ALG THE COAST. WK...DRY TROF/CDFNT MOVES THRU SAT WITH COLD AIR
ADVCTN SHSN PSBL SAT NT/SUN. HI PRES RETURNS SUN NT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
H5 RDG AXIS WILL MOVE ACRS RGN MON NGT IN ADVC OF A STRONG CLOSED
UPR LOW OVER THE SRN PLNS. AS THE WAVE APRCHS LATE MON NGT...WARM
AIR ADVCTN WILL DVLP IN EARNEST...PROVIDING SGFNT MSTR FOR WDSPRD
PCPN. LGT PCPN XPCD TO SPREAD NEWD LATE MON NGT.
CVRG OF PCPN WILL INCR ON TUE AS THE NEGATIVELY-TILTED WAVE
CROSSES THE RGN. GIVEN CONSISTENT FCST AMONG THE MODELS AND
PERSISTENT MEXMOS PCPN SIGNAL ON TUE...CATEGORICAL POPS WERE
INCLUDED ALL ZONES ON TUE. DRY SLOT XPCD TO BRING END TO PCPN TUE
NGT.
EXACT EVOLUTION OF UPR AIR PATTERN THEREAFTER IS LESS CERTAIN...
BUT H5 TROF XPCD TO RMN OVER ERN CONUS. RESULT WILL BE PERSISTENT
COLDER AIR AND OCNL SNOW SHWRS AS WLY-NWLY LOW-LVL FLOW DOMINATES
THE RGN. KRAMAR
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MEDIUM...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
LOW TO MEDIUM CONFIDENCE FORECAST.
AREA OF FZRA CONTINUES TO EXIT QUICKLY WITH PATCHY DRIZZLE AND
FREEZING DRIZZLE IN ITS WAKE. BRIEF IFR WX WILL LAST AT PIT METRO
TERMINALS AND FKL/DUJ THRU 20Z. DRY SLOT THAT IS RACING NE FROM
SERN OH AND WV PER LOW LEVEL DOWNSLOPE WINDS AND SW FLOW ALOFT
REACHES ZZV - PIT - LBE THIS AFTN. BKN VFR CIGS WILL CARRY THROUGH
THE EVENING HOURS AT THE AFOREMENTIONED AIRPORTS.
HARDEST PART OF THE FORECAST IS WHAT WILL HAPPEN OVERNIGHT. ALL OF
THE STATISTICAL GUIDANCE YIELDS MVFR / IFR CIGS WHILE UPSTREAM OBS
SAY IT WILL BE VFR. PLAYED THE OPTIMISTIC ROLE FOR MOST
TERMINALS...SAVE FOR FKL/DUJ/ZZV WHERE MVFR CIGS SHOULD OCCUR FOR AT
LEAST PART OF THE NIGHT. ANY MVFR CIGS LIFT BY MID MRNG DUE TO
LIGHT SW WINDS.
WHERE TAFS COULD GO WRONG:
- MVFR CIGS COULD LINGER THROUGH THE AFTN
- MVFR/IFR CIGS MAY DEVELOP DURING THE OVERNIGHT HOURS AREA WIDE
- MVFR CIGS COULD TAKE UNTIL 15-17Z TO LIFT
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
IFR WEATHER IS POSSIBLE MONDAY NIGHT INTO TUESDAY WITH THE NEXT
WEATHER SYSTEM.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MDZ001.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
PAZ007>009-013>016-022-023.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
238 PM EST FRI FEB 22 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA TODAY WITH A LIGHT
WINTRY MIX MOSTLY COMING TO AN END THIS AFTERNOON AND LINGERING
DRIZZLE CONTINUING INTO THE EVENING. A WEAK COLD FRONT WILL MOVE
THROUGH SATURDAY...FOLLOWED BY BUILDING HIGH PRESSURE SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN UPDATE HAS BEEN ISSUED TO CANCEL THE WINTER WEATHER ADVISORY
FOR THE PITTSBURGH METRO AND FOR ALL OF THE RIDGE ZONES EXCEPT FOR
GARRETT COUNTY. COLD AIR REMAINS DAMMED WITH FREEZING DRIZZLE
ONGOING IN GARRETT CO.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED 500MB LOW
CENTERED ACROSS IOWA. AT THE SURFACE...AN OCCLUDED FRONT EXTENDS
FROM THE LOW IN THE TN VALLEY. FROM THE OCCLUDED FRONT...A WARM
EXTENDS EASTWARD ACROSS CENTRAL WV. 280-300K LAYER ISENTROPIC LIFT
IS PROVIDING FORCING FOR SCATTERED AREAS OF FREEZING RAIN NORTH OF
THE WARM FRONT THIS MORNING FOR LOCATIONS PRIMARILY NORTHEAST OF
A FRANKLIN-CLARION-INDIANA LINE.
THIS AFTERNOON...THE WARM FRONT WILL CONTINUE TO LIFT NORTHWARD
INTO THE UPPER OHIO VALLEY WITH THE AREA OF ISENTROPIC LIFT LIFTING
NORTHEAST OF THE AREA AND BRINGING MEASURABLE MIXED PRECIPITATION
TO AN END. MODEL SOUNDINGS INDICATE THAT DRY AIR ABOVE 800MB WILL
PREVENT ANY DENDRITIC GROWTH INTO THE AFTERNOON...WITH THE LOWER
LEVELS REMAINING SATURATED. THUS...THIS SOUNDING ALLOWS FOR A
DRIZZLE/FREEZING DRIZZLE SCENARIO.
HIGH TEMPS TODAY ARE A FEW DEGREES COOLER THAN LAMP GUIDANCE...RANGING
FROM THE LOWER 30S ACROSS THE I-80 CORRIDOR AND LAUREL
HIGHLANDS/ALLEGHENY FRONT TO MID 40S IN PORTIONS OF EASTERN OHIO
AND NORTH-CENTRAL WV.
TONIGHT...LOW-LEVEL MOISTURE WILL LINGER ACROSS THE AREA NORTH AND
EAST OF PITTSBURGH AS A COLD FRONT APPROACHES FROM THE WEST.
RAP/GFS/NAM SOUNDINGS CONTINUE TO INDICATE A DRY DENDRITIC
GROWTH ZONE WITH A SATURATED LAYER FROM 800MB TO THE SURFACE.
THUS...HAVE CONTINUED MENTIONING OF DZ/FZDZ FOR LOCATIONS NORTH AND
EAST OF PITTSBURGH. TEMPS WILL BE FAIRLY STEADY
OVERNIGHT...RANGING FROM THE LOWER 30S NORTH AND EAST OF
PITTSBURGH TO THE UPPER 30S IN PORTIONS OF EASTERN OHIO AND NORTH-
CENTRAL WV.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
GFS TRIES TO BRING IN PCPN WITH A DVLPG COASTAL LOW ACRS THE
RIDGES SAT. NAM/ECMWF KEEP IT FURTHER E. PREFER THE DRIER SOLNS
GIVEN SE DOWNSLOPING WNDS...AND WITH DVLPG SFC LOW CENTER SO FAR E
ALG THE COAST. WK...DRY TROF/CDFNT MOVES THRU SAT WITH COLD AIR
ADVCTN SHSN PSBL SAT NT/SUN. HI PRES RETURNS SUN NT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
A FAIRLY ACTIVE PATTERN CONTINUES FOR THE START OF THE LONG TERM
WITH ALL OF THE MODELS HAVING ESSENTIALLY A COPY-CAT PATTERN TO
FRIDAYS SYSTEM. A DIGGING UPPER LEVEL TROUGH WILL SHIFT
NORTHEASTWARD THROUGH THE CENTRAL US...HEADING TO THE GREAT LAKES
WHILE ANOTHER LOW DEVELOPS ON THE EAST COAST. AT THIS TIME THE GFS
TENDS TO BE FASTEST WITH THE ECMWF THE SLOWEST. WITH SUCH
UNCERTAINTY IN TIMING...OPTED TO REMAIN NEAR THE GEFS MEAN AND THE
HPC GUIDANCE BUT DID TAKE INTO ACCOUNT THE HIGH MEX GUIDANCE SIGNALS
MON NGT/TUES. BEYOND TUESDAY...MODEL SOLUTIONS DIVERGE COMPLETELY SO
OPTED TO REMAIN CLOSE TO HPC GUIDANCE WITH A DEEP TROUGH KEEPING THE
WEATHER UNSETTLED THROUGH THURSDAY. TEMPERATURES WERE GENERALLY KEPT
NEAR NORMAL THROUGH THE PERIOD.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MEDIUM...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
LOW TO MEDIUM CONFIDENCE FORECAST.
AREA OF FZRA CONTINUES TO EXIT QUICKLY WITH PATCHY DRIZZLE AND
FREEZING DRIZZLE IN ITS WAKE. BRIEF IFR WX WILL LAST AT PIT METRO
TERMINALS AND FKL/DUJ THRU 20Z. DRY SLOT THAT IS RACING NE FROM
SERN OH AND WV PER LOW LEVEL DOWNSLOPE WINDS AND SW FLOW ALOFT
REACHES ZZV - PIT - LBE THIS AFTN. BKN VFR CIGS WILL CARRY THROUGH
THE EVENING HOURS AT THE AFOREMENTIONED AIRPORTS.
HARDEST PART OF THE FORECAST IS WHAT WILL HAPPEN OVERNIGHT. ALL OF
THE STATISTICAL GUIDANCE YIELDS MVFR / IFR CIGS WHILE UPSTREAM OBS
SAY IT WILL BE VFR. PLAYED THE OPTIMISTIC ROLE FOR MOST
TERMINALS...SAVE FOR FKL/DUJ/ZZV WHERE MVFR CIGS SHOULD OCCUR FOR AT
LEAST PART OF THE NIGHT. ANY MVFR CIGS LIFT BY MID MRNG DUE TO
LIGHT SW WINDS.
WHERE TAFS COULD GO WRONG:
- MVFR CIGS COULD LINGER THROUGH THE AFTN
- MVFR/IFR CIGS MAY DEVELOP DURING THE OVERNIGHT HOURS AREA WIDE
- MVFR CIGS COULD TAKE UNTIL 15-17Z TO LIFT
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
IFR WEATHER IS POSSIBLE MONDAY NIGHT INTO TUESDAY WITH THE NEXT
WEATHER SYSTEM.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MDZ001.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
PAZ007>009-013>016-022-023.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1226 PM EST FRI FEB 22 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA TODAY WITH A LIGHT
WINTRY MIX MOSTLY COMING TO AN END THIS AFTERNOON AND LINGERING
DRIZZLE CONTINUING INTO THE EVENING. A WEAK COLD FRONT WILL MOVE
THROUGH SATURDAY...FOLLOWED BY BUILDING HIGH PRESSURE SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN EARLY AFTERNOON UPDATE HAS BEEN ISSUED TO CANCEL THE WINTER
WEATHER ADVISORY FOR PORTIONS OF EASTERN OHIO...NORTHERN PANHANDLE
OF WV...AND EXTREME SOUTHWEST PA.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED 500MB LOW
CENTERED ACROSS IOWA. AT THE SURFACE...AN OCCLUDED FRONT EXTENDS
FROM THE LOW IN THE TN VALLEY. FROM THE OCCLUDED FRONT...A WARM
EXTENDS EASTWARD ACROSS CENTRAL WV. 280-300K LAYER ISENTROPIC LIFT
IS PROVIDING FORCING FOR SCATTERED AREAS OF FREEZING RAIN NORTH OF
THE WARM FRONT THIS MORNING FOR LOCATIONS PRIMARILY NORTHEAST OF
A FRANKLIN-CLARION-INDIANA LINE.
THIS AFTERNOON...THE WARM FRONT WILL CONTINUE TO LIFT NORTHWARD
INTO THE UPPER OHIO VALLEY WITH THE AREA OF ISENTROPIC LIFT LIFTING
NORTHEAST OF THE AREA AND BRINGING MEASURABLE MIXED PRECIPITATION
TO AN END. MODEL SOUNDINGS INDICATE THAT DRY AIR ABOVE 800MB WILL
PREVENT ANY DENDRITIC GROWTH INTO THE AFTERNOON...WITH THE LOWER
LEVELS REMAINING SATURATED. THUS...THIS SOUNDING IS FAVORABLE FOR
A DRIZZLE/FREEZING DRIZZLE SETUP. A LIGHT ICING HAS BEEN REPORTED
ACROSS MOST OF THE AREA AND HIRES MODELS SUPPORT AN ADDITIONAL FEW
HUNDREDTHS OF ICE ACCUMULATION NORTHEAST OF PITTSBURGH.
HIGH TEMPS TODAY ARE A FEW DEGREES COOLER THAN LAMP GUIDANCE...RANGING
FROM THE LOWER 30S ACROSS THE I-80 CORRIDOR AND LAUREL
HIGHLANDS/ALLEGHENY FRONT TO MID 40S IN PORTIONS OF EASTERN OHIO
AND NORTH-CENTRAL WV.
TONIGHT...LOW-LEVEL MOISTURE WILL LINGER ACROSS THE AREA NORTH AND
EAST OF PITTSBURGH AS A COLD FRONT APPROACHES FROM THE WEST.
RAP/GFS/NAM SOUNDINGS CONTINUE TO INDICATE A DRY DENDRITIC
GROWTH ZONE WITH A SATURATED LAYER FROM 800MB TO THE SURFACE.
THUS...HAVE CONTINUED MENTIONING OF DZ/FZDZ FOR LOCATIONS NORTH AND
EAST OF PITTSBURGH. TEMPS WILL BE FAIRLY STEADY
OVERNIGHT...RANGING FROM THE LOWER 30S NORTH AND EAST OF
PITTSBURGH TO THE UPPER 30S IN PORTIONS OF EASTERN OHIO AND NORTH-
CENTRAL WV.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
GFS TRIES TO BRING IN PCPN WITH A DVLPG COASTAL LOW ACRS THE
RIDGES SAT. NAM/ECMWF KEEP IT FURTHER E. PREFER THE DRIER SOLNS
GIVEN SE DOWNSLOPING WNDS...AND WITH DVLPG SFC LOW CENTER SO FAR E
ALG THE COAST. WK...DRY TROF/CDFNT MOVES THRU SAT WITH COLD AIR
ADVCTN SHSN PSBL SAT NT/SUN. HI PRES RETURNS SUN NT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
A FAIRLY ACTIVE PATTERN CONTINUES FOR THE START OF THE LONG TERM
WITH ALL OF THE MODELS HAVING ESSENTIALLY A COPY-CAT PATTERN TO
FRIDAYS SYSTEM. A DIGGING UPPER LEVEL TROUGH WILL SHIFT
NORTHEASTWARD THROUGH THE CENTRAL US...HEADING TO THE GREAT LAKES
WHILE ANOTHER LOW DEVELOPS ON THE EAST COAST. AT THIS TIME THE GFS
TENDS TO BE FASTEST WITH THE ECMWF THE SLOWEST. WITH SUCH
UNCERTAINTY IN TIMING...OPTED TO REMAIN NEAR THE GEFS MEAN AND THE
HPC GUIDANCE BUT DID TAKE INTO ACCOUNT THE HIGH MEX GUIDANCE SIGNALS
MON NGT/TUES. BEYOND TUESDAY...MODEL SOLUTIONS DIVERGE COMPLETELY SO
OPTED TO REMAIN CLOSE TO HPC GUIDANCE WITH A DEEP TROUGH KEEPING THE
WEATHER UNSETTLED THROUGH THURSDAY. TEMPERATURES WERE GENERALLY KEPT
NEAR NORMAL THROUGH THE PERIOD.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MEDIUM...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
LOW TO MEDIUM CONFIDENCE FORECAST.
AREA OF FZRA CONTINUES TO EXIT QUICKLY WITH PATCHY DRIZZLE AND
FREEZING DRIZZLE IN ITS WAKE. BRIEF IFR WX WILL LAST AT PIT METRO
TERMINALS AND FKL/DUJ THRU 20Z. DRY SLOT THAT IS RACING NE FROM
SERN OH AND WV PER LOW LEVEL DOWNSLOPE WINDS AND SW FLOW ALOFT
REACHES ZZV - PIT - LBE THIS AFTN. BKN VFR CIGS WILL CARRY THROUGH
THE EVENING HOURS AT THE AFOREMENTIONED AIRPORTS.
HARDEST PART OF THE FORECAST IS WHAT WILL HAPPEN OVERNIGHT. ALL OF
THE STATISTICAL GUIDANCE YIELDS MVFR / IFR CIGS WHILE UPSTREAM OBS
SAY IT WILL BE VFR. PLAYED THE OPTIMISTIC ROLE FOR MOST
TERMINALS...SAVE FOR FKL/DUJ/ZZV WHERE MVFR CIGS SHOULD OCCUR FOR AT
LEAST PART OF THE NIGHT. ANY MVFR CIGS LIFT BY MID MRNG DUE TO
LIGHT SW WINDS.
WHERE TAFS COULD GO WRONG:
- MVFR CIGS COULD LINGER THROUGH THE AFTN
- MVFR/IFR CIGS MAY DEVELOP DURING THE OVERNIGHT HOURS AREA WIDE
- MVFR CIGS COULD TAKE UNTIL 15-17Z TO LIFT
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
IFR WEATHER IS POSSIBLE MONDAY NIGHT INTO TUESDAY WITH THE NEXT
WEATHER SYSTEM.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR OHZ040-
041-050.
PA...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
PAZ007>009-013>016-022-023-074-076.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR PAZ020-
021-029-073-075.
WV...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
WVZ023-041.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ001-
002.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...98
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1019 AM EST FRI FEB 22 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA TODAY WITH A LIGHT
WINTRY MIX MOSTLY COMING TO AN END THIS AFTERNOON AND LINGERING
DRIZZLE CONTINUING INTO THE EVENING. A WEAK COLD FRONT WILL MOVE
THROUGH SATURDAY...FOLLOWED BY BUILDING HIGH PRESSURE SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A QUICK UPDATE WAS ISSUED THIS MORNING BASED ON RECENT OBS...RADAR
TRENDS...AND MODEL SOUNDINGS THIS MORNING. PRECIP WAS CHANGED TO ALL
LIGHT FREEZING RAIN SOUTHWEST OF PITTSBURGH AND RAIN IN
NORTH-CENTRAL WV. THE WINTER WEATHER ADVISORY HAS BEEN ALLOWED TO
EXPIRE IN NORTH-CENTRAL WV AND HAS BEEN CONTINUED IN EASTERN OHIO.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED 500MB LOW
CENTERED ACROSS IOWA. AT THE SURFACE...AN OCCLUDED FRONT EXTENDS
FROM THE LOW IN THE TN VALLEY. FROM THE OCCLUDED FRONT...A WARM
EXTENDS EASTWARD ACROSS CENTRAL WV. 280-300K LAYER ISENTROPIC LIFT
IS PROVIDING FORCING FOR SCATTERED AREAS OF FREEZING RAIN NORTH OF
THE WARM FRONT THIS MORNING FOR LOCATIONS PRIMARILY NORTHEAST OF
A NEW PHILADELPHIA-WHEELING-MORGANTOWN LINE.
THIS AFTERNOON...THE WARM FRONT WILL CONTINUE TO LIFT NORTHWARD
INTO THE UPPER OHIO VALLEY WITH THE AREA OF ISENTROPIC LIFT LIFTING
NORTHEAST OF THE AREA AND BRINGING MEASURABLE MIXED PRECIPITATION
TO AN END. MODEL SOUNDINGS INDICATE THAT DRY AIR ABOVE 750MB WILL
PREVENT ANY DENDRITIC GROWTH INTO THE AFTERNOON...WITH THE LOWER
LEVELS REMAINING SATURATED. THUS...THIS SOUNDING IS FAVORABLE FOR
A DRIZZLE/FREEZING DRIZZLE SETUP. WITH THIS IN MIND...HAVE
EXTENDED THE WINTER WEATHER ADVISORY IN OHIO WITH TEMPS STILL
BELOW FREEZING AND ADDED MORE MENTION OF DRIZZLE/FZDZ ACROSS THE
AREA THIS EVENING. A LIGHT ICING HAS BEEN REPORTED ACROSS MOST OF
THE AREA AND HIRES MODELS SUPPORT AN ADDITIONAL FEW HUNDREDTHS OF
ICE ACCUMULATION IN WESTERN PA AND THE ALLEGHENY FRONT OF MD/WV.
HIGH TEMPS TODAY ARE A FEW DEGREES COOLER THAN LAMP
GUIDANCE...RANGING FROM THE LOWER 30S ACROSS THE I-80 CORRIDOR
AND LAUREL HIGHLANDS/ALLEGHENY FRONT TO MID 40S IN PORTIONS OF
EASTERN OHIO AND NORTH-CENTRAL WV.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
SOME PTCHY FZDZ COULD LINGER THIS EVE N OF I 80 AND IN THE RIDGES
WITH AMPLE LLVL MOISTURE. GFS TRIES TO BRING IN PCPN WITH A DVLPG
COASTAL LOW ACRS THE RIDGES SAT. NAM/ECMWF KEEP IT FURTHER E.
PREFER THE DRIER SOLNS GIVEN SE DOWNSLOPING WNDS...AND WITH DVLPG
SFC LOW CENTER SO FAR E ALG THE COAST. WK...DRY TROF/CDFNT MOVES
THRU SAT WITH COLD AIR ADVCTN SHSN PSBL SAT NT/SUN. HI PRES
RETURNS SUN NT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
A FAIRLY ACTIVE PATTERN CONTINUES FOR THE START OF THE LONG TERM
WITH ALL OF THE MODELS HAVING ESSENTIALLY A COPY-CAT PATTERN TO
FRIDAYS SYSTEM. A DIGGING UPPER LEVEL TROUGH WILL SHIFT
NORTHEASTWARD THROUGH THE CENTRAL US...HEADING TO THE GREAT LAKES
WHILE ANOTHER LOW DEVELOPS ON THE EAST COAST. AT THIS TIME THE GFS
TENDS TO BE FASTEST WITH THE ECMWF THE SLOWEST. WITH SUCH
UNCERTAINTY IN TIMING...OPTED TO REMAIN NEAR THE GEFS MEAN AND THE
HPC GUIDANCE BUT DID TAKE INTO ACCOUNT THE HIGH MEX GUIDANCE SIGNALS
MON NGT/TUES. BEYOND TUESDAY...MODEL SOLUTIONS DIVERGE COMPLETELY SO
OPTED TO REMAIN CLOSE TO HPC GUIDANCE WITH A DEEP TROUGH KEEPING THE
WEATHER UNSETTLED THROUGH THURSDAY. TEMPERATURES WERE GENERALLY KEPT
NEAR NORMAL THROUGH THE PERIOD.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
MEDIUM CONFIDENCE FORECAST.
AREA OF FZRA BRIEFLY MIXING WITH SLEET WILL VACATE THE AREA BY 17Z
OWING TO SPOTTY DZ AND FZDZ THE BALANCE OF THE AFTERNOON. IFR CIGS
ARE EXPECT FOR A SHORT PERIOD AT ZZV THRU 16Z...OTHERWISE MOST SITES
SHALL STAY MVFR THROUGH THE BALANCE OF THE FORECAST.
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
IFR WEATHER IS POSSIBLE MONDAY NIGHT INTO TUESDAY WITH THE NEXT
WEATHER SYSTEM.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR OHZ039-048-
049-057>059-068-069.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR OHZ040-
041-050.
PA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR PAZ031.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
PAZ007>009-013>016-022-023-074-076.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR PAZ020-
021-029-073-075.
WV...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR WVZ003-004.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
WVZ023-041.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ001-
002.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...98
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
620 AM EST FRI FEB 22 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY WEAKEN OVER THE REGION THROUGH
TODAY...WHILE LOW PRESSURE DEVELOPS OVER THE CENTRAL GULF COAST
STATES. THE LOW WILL TRACK NORTHEAST TO OFF THE VIRGINIA COAST
TONIGHT THROUGH SATURDAY. HIGH PRESSURE RETURNS TO THE MID
ATLANTIC STATES SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DRY AIR OVR THE FA HOLDING ON ATTM. SPLIT IN PCPN AS IT HAS
ENTERED THE RGN HAS OCCURRED...W/ ONLY VRY SPOTTY/LGT PCPN FM
CNTRL VA ON S INTO INTR NE NC. HAVE CONTEMPLATED LWRG THE WINTER
WX ADSVRY...THOUGH CONTG TO WATCH AN AREA OF PCPN MOVING THROUGH
WCNTRL VA (FM THE MTNS) IN THE PAST HR OR TWO WHICH MAY HOLD
TOGETHER INTO PORTIONS OF THE ADVSRY AREA. TEMPS RMN AT OR SLGTLY
ABV FRZG MOST PLACES. HV MADE MINOR ADJSTMNTS TO POPS/TEMPS BASED
ON TRENDS AND LATEST LAV GUID.
PREV DISCUSSION:
SFC HI PRES (NR 1030MB) RMNS WEDGED OVR THE FA...RESULTING IN MDT
CAD. DEWPTS RMN IN THE TEENS OVR THE FA ATTM. PCPN SPREADING EWD
THROUGH SW VA AND WRN/CNTRL NC AS WEAKENING MID LVL S/W MOVES INTO
THE CNTRL MTNS. THE PCPN IS ENCOUNTERING THE SUBSTANTIAL LO LVL
DRY AIR IN PLACE THIS FAR E OF THE MTNS. ADDITIONALLY...RECENT
TRENDS IN RADAR SUGGEST THAT THE GFS/RUC IDEA OF A SPLIT IN THE
PCPN (ONE AREA PUSHING N INTO NRN WV/NW VA AND WRN PA...THE OTHER
MOVING E ACRS NC/EXTREME SW VA) IS CORRECT. SO FAR...ROA/LYH AND
HSP HAVE RECEIVED NO PCPN...AND THAT MAY SUGGEST THAT ANY
WIDESPREAD PCPN WILL BE DIFFICULT TO REACH CNTRL AND ERN VA
THROUGH THE ERY MRNG/MIDDAY HRS. 00Z GFS AND 03Z RUC BOTH ONLY
BRING ABT A HUNDREDTH OR TWO INTO CNTRL AND NRN SECTIONS OF THE
FA...W/ HIGHEST QPF (THOUGH ONLY TO ABT 0.05" ON AVG) TO AREAS
NR/S OF THE VA/NC BORDER IN INTR SRN VA/NE NC. MDL SNDGS HAVE
SUBSTANTIAL DRYING AOA 700MB BY MID/LT MRNG HRS ACRS THE FA...AND
CONT THAT THROUGH THE AFTN...POINTING TO ONLY LGT/SPOTTY PCPN ACRS
THE FA AS TEMPS RISE ABV FRZG (LASTLY PTNTLLY OVR THE FAR NW PDMNT
CTYS WHERE TEMPS XPCD TO HOVER NR FRZG ALL DAY).
PTYPE IS THE OTHER CONCERN...WILL HAVE CHCS FOR SN/IP AS WELL AS
FRZG RA (AGN AMTS VRY LGT...AND INCRSGLY SPOTTY THROUGH THE
ERY/MID MRNG HRS). WILL KP WINTER WX ADSVRY AS IS FOR NOW...AND
MONITOR TRENDS THROUGH ERY MRNG. ANY ACCUMS (ESP ICE)...GENLY AOB
0.01-0.02". SPOTTY LGT RA AND/OR DZ FM MIDDAY THROUGH THE AFTN
HRS...AGN QPF QUITE LGT (LESS THAN 0.05") THROUGHOUT.
HI TEMPS FM NR 32F FAR NW TO L40S FAR SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
HIGHER CONFIDENCE/PROB FOR PCPN TNGT FM SW TO NE AS LO PRES FM
THE CNTRL GULF STATES TRACKS NE THROUGH GA/SC/NC. INCRSD POPS TO
80-100% ACRS MUCH OF THE AREA OVRNGT...W/ 60-80% FAR NNE SECTIONS.
HI PROB (90-100% POPS) OVR ENTIRE FA SAT MRNG. THE LO REACHES OFF
THE VA CST SAT AFTN/EVE LEADING TO A GRADUAL LWRG OF POPS FM WSW
TO E (THOUGH CLDNS WILL HANG ON). STM TOTAL QPF RANGING FM
0.25-0.50" NW TO 1-1.5" SE. TEMPS HOLD NRLY STEADY OR ONLY RISE A
CPL/FEW DEGS F INLAND...WHILE CLOSE TO THE CST...ESP SE VA/NE
NC...TEMPS RISE INTO/THROUGH THE 40S. HI TEMPS SAT M40S NW TO
M/U50S SE VA/NE NC.
SLOLY DRYING OUT BY LT SAT NGT/ERY SUN. SFC HI PRES BUIDS TWD THE
RGN FM THE NW ON SUN LEADING TO SUBSTANTIAL CLRG (AND MNLY SUNNY)
AND MILD CONDS. HI TEMPS 50-55F N TO 55-60F S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE BUILDS IN FROM THE WEST ON SUNDAY WITH DRY CONDITIONS
INTO SUNDAY NIGHT. A NEGATIVELY TILTED UPPER LEVEL RIDGE AMPLIFIES
OVER THE REGION ON MONDAY IN RESPONSE TO A BROAD UPPER LEVEL TROUGH
DIGGING OVER THE CTRL PLAINS. WEAK ENERGY FLOWING AROUND THE BASE OF
THE AFOREMENTIONED TROUGH IS EXPECTED TO MOVE NE ACROSS THE SE
STATES AS SW FLOW DEVELOPS ALOFT. THIS ENERGY AND ASSOCIATED
PRECIPITATION (ALL RAIN) IS THEN EXPECTED TO MOVE THROUGH THE MID
ATLANTIC REGION MONDAY NIGHT INTO TUESDAY. THERE WERE INDICATIONS OF
A COASTAL LOW DEVELOPING TUESDAY NIGHT ONCE IT MOVES OVER THE WATER
AND THIS TREND HAS CONTINUED...HOWEVER THERE ARE NOW MORE ADVERSE
TIMING DIFFERENCES BTWN VARIOUS 12Z MODEL RUNS. WILL TREND THE
FORECAST BTWN THE TWO MODELS FOR THE TIME BEING. A BROAD UPPER
TROUGH BECOMES ANCHORED OVER THE NE CONUS THE REMAINDER OF THE
WEEK...KEEPING CONDITIONS COOL AND UNSETTLED.
&&
.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
SHORTWV ENERGY WILL PUSH ACRS THE AREA THIS MORNG INTO EARLY THIS
AFTN...AND MAY BRING A MIX OF LIGHT SLEET...SNOW OR FREEZING RAIN.
OTHRWISE...CLDS WILL THICKEN AND LWR DURING TODAY...AS WINDS
BECOME ESE WELL AHEAD OF LO PRES DEVELOPING OVR THE GULF CST
STATES. MVFR/IFR CIGS/VSBYS THEN LIKELY THIS EVENG INTO SAT
NGT...AS THE LO MOVES UP ALNG AND JUST OFF THE CST...BRINGING
RAIN TO THE AREA. DRY/VFR CONDITIONS RETURN SUN INTO MON...AS
HI PRES BLDS IN FM THE W.
&&
.MARINE...
NO HEADLINES IN THE MARINE AREA THRU TNGT...BUT WILL LIKELY NEED
TO ISSUE SCA`S FOR AT LEAST THE CHES BAY AND CSTL ZNS FOR SAT INTO
EARLY SUN...DUE TO LO PRES MOVNG UP ALNG AND JUST OFF THE CST. N
WINDS 10 TO 15 KT EARLY THIS MORNG...WILL BECOME ESE 10 KT OR LESS
THIS AFTN. ESE WINDS 10 TO 20 KT AND GUSTY THEN EXPECTED LATER
TNGT INTO SAT AFTN...THEN BECOME NW 10 TO 20 KT AND GUSTY FOR SAT
NGT THRU SUN...AS THE LO MOVES AWAY TO THE NE AND HI PRES BLDS IN
FM THE WNW. HI PRES WILL BLD INTO AND OVR THE REGION FOR LATER SUN
INTO MON.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NCZ012-013-030.
VA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
VAZ092.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ060-
065>067-079-080-087-088.
MARINE...NONE.
&&
$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB
SHORT TERM...ALB
LONG TERM...BMD
AVIATION...TMG
MARINE...TMG
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
434 AM EST FRI FEB 22 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY WEAKEN OVER THE REGION THROUGH
TODAY...WHILE LOW PRESSURE DEVELOPS OVER THE CENTRAL GULF COAST
STATES. THE LOW WILL TRACK NORTHEAST TO OFF THE VIRGINIA COAST
TONIGHT THROUGH SATURDAY. HIGH PRESSURE RETURNS TO THE MID
ATLANTIC STATES SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC HI PRES (NR 1030MB) RMNS WEDGED OVR THE FA...RESULTING IN MDT
CAD. DEWPTS RMN IN THE TEENS OVR THE FA ATTM. PCPN SPREADING EWD
THROUGH SW VA AND WRN/CNTRL NC AS WEAKENING MID LVL S/W MOVES INTO
THE CNTRL MTNS. THE PCPN IS ENCOUNTERING THE SUBSTANTIAL LO LVL
DRY AIR IN PLACE THIS FAR E OF THE MTNS. ADDITIONALLY...RECENT
TRENDS IN RADAR SUGGEST THAT THE GFS/RUC IDEA OF A SPLIT IN THE
PCPN (ONE AREA PUSHING N INTO NRN WV/NW VA AND WRN PA...THE OTHER
MOVING E ACRS NC/EXTREME SW VA) IS CORRECT. SO FAR...ROA/LYH AND
HSP HAVE RECEIVED NO PCPN...AND THAT MAY SUGGEST THAT ANY
WIDESPREAD PCPN WILL BE DIFFICULT TO REACH CNTRL AND ERN VA
THROUGH THE ERY MRNG/MIDDAY HRS. 00Z GFS AND 03Z RUC BOTH ONLY
BRING ABT A HUNDREDTH OR TWO INTO CNTRL AND NRN SECTIONS OF THE
FA...W/ HIGHEST QPF (THOUGH ONLY TO ABT 0.05" ON AVG) TO AREAS
NR/S OF THE VA/NC BORDER IN INTR SRN VA/NE NC. MDL SNDGS HAVE
SUBSTANTIAL DRYING AOA 700MB BY MID/LT MRNG HRS ACRS THE FA...AND
CONT THAT THROUGH THE AFTN...POINTING TO ONLY LGT/SPOTTY PCPN ACRS
THE FA AS TEMPS RISE ABV FRZG (LASTLY PTNTLLY OVR THE FAR NW PDMNT
CTYS WHERE TEMPS XPCD TO HOVER NR FRZG ALL DAY).
PTYPE IS THE OTHER CONCERN...WILL HAVE CHCS FOR SN/IP AS WELL AS
FRZG RA (AGN AMTS VRY LGT...AND INCRSGLY SPOTTY THROUGH THE
ERY/MID MRNG HRS). WILL KP WINTER WX ADSVRY AS IS FOR NOW...AND
MONITOR TRENDS THROUGH ERY MRNG. ANY ACCUMS (ESP ICE)...GENLY AOB
0.01-0.02". SPOTTY LGT RA AND/OR DZ FM MIDDAY THROUGH THE AFTN
HRS...AGN QPF QUITE LGT (LESS THAN 0.05") THROUGHOUT.
HI TEMPS FM NR 32F FAR NW TO L40S FAR SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
HIGHER CONFIDENCE/PROB FOR PCPN TNGT FM SW TO NE AS LO PRES FM
THE CNTRL GULF STATES TRACKS NE THROUGH GA/SC/NC. INCRSD POPS TO
80-100% ACRS MUCH OF THE AREA OVRNGT...W/ 60-80% FAR NNE SECTIONS.
HI PROB (90-100% POPS) OVR ENTIRE FA SAT MRNG. THE LO REACHES OFF
THE VA CST SAT AFTN/EVE LEADING TO A GRADUAL LWRG OF POPS FM WSW
TO E (THOUGH CLDNS WILL HANG ON). STM TOTAL QPF RANGING FM
0.25-0.50" NW TO 1-1.5" SE. TEMPS HOLD NRLY STEADY OR ONLY RISE A
CPL/FEW DEGS F INLAND...WHILE CLOSE TO THE CST...ESP SE VA/NE
NC...TEMPS RISE INTO/THROUGH THE 40S. HI TEMPS SAT M40S NW TO
M/U50S SE VA/NE NC.
SLOLY DRYING OUT BY LT SAT NGT/ERY SUN. SFC HI PRES BUIDS TWD THE
RGN FM THE NW ON SUN LEADING TO SUBSTANTIAL CLRG (AND MNLY SUNNY)
AND MILD CONDS. HI TEMPS 50-55F N TO 55-60F S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE BUILDS IN FROM THE WEST ON SUNDAY WITH DRY CONDITIONS
INTO SUNDAY NIGHT. A NEGATIVELY TILTED UPPER LEVEL RIDGE AMPLIFIES
OVER THE REGION ON MONDAY IN RESPONSE TO A BROAD UPPER LEVEL TROUGH
DIGGING OVER THE CTRL PLAINS. WEAK ENERGY FLOWING AROUND THE BASE OF
THE AFOREMENTIONED TROUGH IS EXPECTED TO MOVE NE ACROSS THE SE
STATES AS SW FLOW DEVELOPS ALOFT. THIS ENERGY AND ASSOCIATED
PRECIPITATION (ALL RAIN) IS THEN EXPECTED TO MOVE THROUGH THE MID
ATLANTIC REGION MONDAY NIGHT INTO TUESDAY. THERE WERE INDICATIONS OF
A COASTAL LOW DEVELOPING TUESDAY NIGHT ONCE IT MOVES OVER THE WATER
AND THIS TREND HAS CONTINUED...HOWEVER THERE ARE NOW MORE ADVERSE
TIMING DIFFERENCES BTWN VARIOUS 12Z MODEL RUNS. WILL TREND THE
FORECAST BTWN THE TWO MODELS FOR THE TIME BEING. A BROAD UPPER
TROUGH BECOMES ANCHORED OVER THE NE CONUS THE REMAINDER OF THE
WEEK...KEEPING CONDITIONS COOL AND UNSETTLED.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
SHORTWV ENERGY WILL PUSH ACRS THE AREA THIS MORNG INTO EARLY THIS
AFTN...AND MAY BRING A MIX OF LIGHT SLEET...SNOW OR FREEZING RAIN.
OTHRWISE...CLDS WILL THICKEN AND LWR DURING TODAY...AS WINDS
BECOME ESE WELL AHEAD OF LO PRES DEVELOPING OVR THE GULF CST
STATES. MVFR/IFR CIGS/VSBYS THEN LIKELY THIS EVENG INTO SAT
NGT...AS THE LO MOVES UP ALNG AND JUST OFF THE CST...BRINGING
RAIN TO THE AREA. DRY/VFR CONDITIONS RETURN SUN INTO MON...AS
HI PRES BLDS IN FM THE W.
&&
.MARINE...
NO HEADLINES IN THE MARINE AREA THRU TNGT...BUT WILL LIKELY NEED
TO ISSUE SCA`S FOR AT LEAST THE CHES BAY AND CSTL ZNS FOR SAT INTO
EARLY SUN...DUE TO LO PRES MOVNG UP ALNG AND JUST OFF THE CST. N
WINDS 10 TO 15 KT EARLY THIS MORNG...WILL BECOME ESE 10 KT OR LESS
THIS AFTN. ESE WINDS 10 TO 20 KT AND GUSTY THEN EXPECTED LATER
TNGT INTO SAT AFTN...THEN BECOME NW 10 TO 20 KT AND GUSTY FOR SAT
NGT THRU SUN...AS THE LO MOVES AWAY TO THE NE AND HI PRES BLDS IN
FM THE WNW. HI PRES WILL BLD INTO AND OVR THE REGION FOR LATER SUN
INTO MON.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NCZ012-013-030.
VA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
VAZ092.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ060-
065>067-079-080-087-088.
MARINE...NONE.
&&
$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB
SHORT TERM...ALB
LONG TERM...BMD
AVIATION...TMG
MARINE...TMG
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
358 AM EST FRI FEB 22 2013
.SYNOPSIS...
HIGH PRESSURE IS MOVING OFF THE COAST...AHEAD OF AN APPROACHING LOW
PRESSURE SYSTEM FROM THE MIDWEST. A COASTAL LOW PRESSURE SYSTEM
WILL IMPACT THE AREA SATURDAY BEFORE HIGH PRESSURE RETURNS SUNDAY
INTO THE EARLY PART OF NEXT WEEK. LOW PRESSURE WILL AFFECT THE
AREA DURING THE MID PART OF NEXT WEEK.
&&
.NEAR TERM /TODAY/...
THIS IS A VERY TRICKY FCST. AS I HV WRITTEN THE PAST TWO NGTS IN MY
DSCN THIS IS NOT A TYPICAL SYNOPTIC SET UP FOR FZRA WHERE HIGH PRES
IS CAMPED OUT OVR NY STATE AND COLD DRY AIR ON NRLY WINDS IS BEING
FED INTO THE MID ATLC ON THE E SIDE OF THE APLCHNS WHILE MOISTURE
STREAMS UP FM THE S. TNGT THERE IS A STRONG AREA OF HIGH PRES...BUT
IT IS CENTERED OVR MOOSONEE ON THE S SHORE OF JAMES BAY. THE S SIDE
OF THAT HIGH WL BE MOVG OFFSHORE THIS AFTN...MOST LKLY THE LOW LVL
WINDS E OF THE APLCHNS WL BE FM THE SE. AGN THIS IS NOT FAVORABLE
FOR LO LVL CAD AND FZN/FRZG PCPN. IN ADTN DWPTS ARE STILL IN THE M
TEENS. THE ATMOSPHERIC COLUMN IS GOING TO REQUIRE SOME TIME TO
MOISTEN.
ATTM THE MOISTURE ATTEMPTING TO SPREAD NEWD IS RUNNING INTO THAT
HIGH PRES RDG.
ANOTHER CONSIDERATION WL BE SFC TEMPS TDA. THE TEMPS I INHERITED
WERE IN MANY CASES SVRL DEGS BLO WHAT ANY 00Z MDL GDNC WAS
PRESENTING. THERE ARE CASES WHERE THAT IS THE RIGHT WAY TO GO...BUT
DURG FEB I`D ESTIMATE THAT 1ST PD MDL TEMP VERIFICATION HAS BEEN TOO
WARM ABT 65-70% OF THE TIME. SO BTWN THAT HISTORY AND THAT THE HIGH IS NOT
IN A POSN TO HOLD IN CD AIR I`VE TAKEN TEMPS E OF THE MTNS UP SVRL
DEGS FOR TDA...WHICH OF COURSE IS A BIG DEAL WHEN U R CLOSE TO FRZG
W/ PCPN APRCHG.
HIGHS WON`T CHG A LOT TDA FM MRNG TEMPS - M30S E OF THE BLUE
RDG...MU30S IN THE CITIES. W/ THE XPCTN OF AT HIGHER ELEVS WE
ACTUALLY HV THE ENTIRE CWA AOA FRZG. THIS WL NOT PRECLUDE THE PSBLTY
OF IP/S...BUT LIMITS THE THREAT OF FZRA WHICH IS OF COURSE THE
BIGGEST TRAVEL CONCERN. BECAUSE OF THE HIGHER ELEVS GOING SUB FRZG
IT IS LKLY THAT WE WL NEED TO BE ISSUING A WINT WX ADVSRY. SEE
COUNTIES AT BOTTOM OF THIS PRODUCT OR ON OUR WEB SITE. HOWEVER AT
THIS TIME WE DO NOT FORESEE THE NEED FOR ONE IN THE DC/BALT RGN TDA.
AND YET ANOTHER CONSIDERATION IS HOW MUCH PCPN IS GOING TO RCV. 21Z
SREF...01Z HRRR AND 00Z ECM REALLY TEAR THE PCPN APART WHEN IT TRIES
TO MOVE E OF THE MTNS. BUT THE COMP RDR IS SHOWING HIGHER REF OVR
SWRN VA...HOWEVER THE HIGHER REFLECTIVITIES ARE QUITE PSBLY DUE TO
BRIGHT BANDING.
&&
.SHORT TERM /TONIGHT/...
IN BOTH PDS THE MAIN CONCERN IS WHETHER WE NEED TO ISSUE AN ADVSRY
AS WELL AS WHERE. TNGT LOOKS LK ANOTHER BORDERLINE SITUATION WHERE
ADVSORIES MAY BE REQUIRED...BUT WE ARE PUTTING OUR MENTAL ENERGIES
ON TRYING TO SOLVE THE TDA PD AND BUY THE DAYSHIFT SOME TIME TO
ATTEMPT TO FIGURE OUT IF HEADLINES ARE NEEDED TNGT. AGN IT LOOKS LK
IF THESE ARE NEEDED THE WRN PART OF THE CWA HAS THE BEST BET AS
TEMPS E OF THE BLUE RDG WL BE XTRMLY MARGINAL.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
SRN STREAM JET INCREASES AND SPREADS EAST ACROSS THE E-CNTRL CONUS
SATURDAY AHEAD OF AN UPR TROUGH AXIS REACHING THE MID-SOUTH STATES
BY THE EVENING BEFORE CROSSING THE MID-ATLANTIC SATURDAY NIGHT. A
COASTAL LOW WILL DEVELOP NEAR THE NC/VA BORDER MIDDAY SATURDAY AND
SPREAD NORTHEAST OFF THE DELMARVA THROUGH THE EVENING. STRATIFORM
RAIN AHEAD OF THIS LOW LOOKS TO OVERSPREAD THE AREA MAINLY EAST FROM
THE BLUE RIDGE SATURDAY MORNING...THEN CONTRACT AND PULL NORTHEAST
AS THE LOW DEVELOPS AND MOVES OFF.
SATURDAY...MIN TEMPS WILL PLAY A MAJOR ROLE WHETHER PRECIP STARTS
OFF AS FREEZING OR PLAIN RAIN. AS OF NOW FAR NW BALT-WASH SUBURBS
LOOK TO BE RIGHT AROUND 32F SO POCKETS OF FREEZING RAIN ARE POSSIBLE
THERE AND THE BLUE RIDGE WEST TO THE POTOMAC HIGHLANDS. THIS ICY
SCENARIO COULD LAST THROUGH THE MID MORNING HOURS. OTHERWISE PLAIN
RAIN.
SATURDAY NIGHT...PRECIP PULLS OUT OF THE AREA TO THE NORTHEAST WITH
THE LOW. THE UPPER TROUGH AXIS PUSHES THROUGH FROM THE WEST LATE IN
THE NIGHT...SO 30 POP AND WHAT THERMALLY WOULD BE SNOW SHOWERS OR
FLURRIES WERE ADDED FOR THE NORTHEASTERN 2/3 OF THE LWX CWA. THIS IS
A FAIRLY LOW CONFIDENCE FORECAST /NO MODEL ACTUALLY PRINTS OUT
PRECIP OVER LWX/ AND THE DAY SHIFT WILL HAVE TO ANALYZE THIS
POTENTIAL FURTHER. PERHAPS FLURRY WORDING WOULD BE BETTER.
SUNDAY AND MONDAY...SFC HIGH PRESSURE BUILDS OVERHEAD WITH AT OR
JUST ABOVE NORMAL TEMPERATURES AND DRY WEATHER. NWLY GUSTS ON SUNDAY
LOOK TO BE IN THE 30 TO 35 MPH RANGE.
THE NEXT ACTIVE WEATHER COMES IN A SIMILAR PATTERN TO THE CURRENT
LOW SYSTEM WITH A CNTRL CONUS LOW DEVELOPING AND OCCLUDING OVER THE
MIDWEST AS A LEADING WAVE APPROACHES THE MID-ATLANTIC. TIMING IS
UNCERTAIN AS SHOWN BY OPERATIONAL 00Z ECMWF/GFS OFF BY ABOUT 12 HRS
/GFS QUICKER AND MORE MONDAY NIGHT WHILE ECMWF IS TUESDAY FOR
PRECIP/. SFC LOW DEVELOPMENT ALONG THE LEADING WAVE LOOKS LIKELY SO
P-TYPE IS QUITE UNCERTAIN AS OF NOW. MAINTAINED LOOK OF RAIN OR SNOW
FOR ALL AREAS OUTSIDE OF SRN MD WHICH SEEMS REASONABLE.
THE OCCLUDED LOW THEN PERSISTS INTO THE LATER PARTS OF NEXT
WEEK...POSSIBLY BRINGING MORE ACTIVE WEATHER TO THE MID-ATLANTIC.
EXTENDED GRIDS LEFT ALONE TONIGHT.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
CIGS CURRENTLY IN VFR RANGE. THESE ARE XPCTD TO LOWER DURG THE
DAY..DROPPING INTO LIFR AT CHO BY MID AFTN...AND IAD/DCA LATE THIS
AFTN. FRUTHER LOWERING PSBL THIS EVE AS A LGT WINTRY MIX OF PCPN
OVERPREADS THE RGN.
IFR A SURE BET FOR SATURDAY AS SLY FLOW BRING LOW CLOUDS AND RAIN TO
THE TERMINALS. PRECIP PUSHES OUT TO THE NORTHEAST SATURDAY EVENING
WITH POTENTIAL FOR SOME FLURRIES LATE IN THE NIGHT. NWLY GUSTS 25 TO
30 KT EXPECTED BEHIND THE COLD FRONT ON SUNDAY. VFR MONDAY UNDER
HIGH PRESSURE THEN NEXT ACTIVE WEATHER RAIN OR POSSIBLE MIX MONDAY
NIGHT OR TUESDAY.
&&
.MARINE...
WINDS BLO DCA VALUES TDA AND TNGT.
SCA LIKELY NEEDED FOR SATURDAY MIDDAY AND ON FOR ONSHORE FLOW FROM
LOW CENTER CROSSING VA PORTION OF THE BAY. NWLY FLOW THEN STARTS
SATURDAY NIGHT AND GUSTY THROUGH SUNDAY. SCA THROUGH THIS TIME WITH
PEAK GUSTS AROUND 30 KT. TRANQUIL ON MONDAY IN ADVANCE OF THE NEXT
WEATHER MONDAY NIGHT OR TUESDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR MDZ501-
502.
VA...WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR
VAZ025>027-029-036>040-503-504.
WV...WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR WVZ050-
055-501>506.
MARINE...NONE.
&&
$$
PRODUCTS...WOODY!/BAJ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
349 AM EST FRI FEB 22 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY WEAKEN OVER THE REGION THROUGH
TODAY...WHILE LOW PRESSURE DEVELOPS OVER THE CENTRAL GULF COAST
STATES. THE LOW WILL TRACK NORTHEAST TO OFF THE VIRGINIA COAST
TONIGHT THROUGH SATURDAY. HIGH PRESSURE RETURNS TO THE MID
ATLANTIC STATES SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC HI PRES (NR 1030MB) RMNS WEDGED OVR THE FA...RESULTING IN MDT
CAD. DEWPTS RMN IN THE TEENS OVR THE FA ATTM. PCPN SPREADING EWD
THROUGH SW VA AND WRN/CNTRL NC AS WEAKENING MID LVL S/W MOVES INTO
THE CNTRL MTNS. THE PCPN IS ENCOUNTERING THE SUBSTANTIAL LO LVL
DRY AIR IN PLACE THIS FAR E OF THE MTNS. ADDITIONALLY...RECENT
TRENDS IN RADAR SUGGEST THAT THE GFS/RUC IDEA OF A SPLIT IN THE
PCPN (ONE AREA PUSHING N INTO NRN WV/NW VA AND WRN PA...THE OTHER
MOVING E ACRS NC/EXTREME SW VA) IS CORRECT. SO FAR...ROA/LYH AND
HSP HAVE RECEIVED NO PCPN...AND THAT MAY SUGGEST THAT ANY
WIDESPREAD PCPN WILL BE DIFFICULT TO REACH CNTRL AND ERN VA
THROUGH THE ERY MRNG/MIDDAY HRS. 00Z GFS AND 03Z RUC BOTH ONLY
BRING ABT A HUNDREDTH OR TWO INTO CNTRL AND NRN SECTIONS OF THE
FA...W/ HIGHEST QPF (THOUGH ONLY TO ABT 0.05" ON AVG) TO AREAS
NR/S OF THE VA/NC BORDER IN INTR SRN VA/NE NC. MDL SNDGS HAVE
SUBSTANTIAL DRYING AOA 700MB BY MID/LT MRNG HRS ACRS THE FA...AND
CONT THAT THROUGH THE AFTN...POINTING TO ONLY LGT/SPOTTY PCPN ACRS
THE FA AS TEMPS RISE ABV FRZG (LASTLY PTNTLLY OVR THE FAR NW PDMNT
CTYS WHERE TEMPS XPCD TO HOVER NR FRZG ALL DAY).
PTYPE IS THE OTHER CONCERN...WILL HAVE CHCS FOR SN/IP AS WELL AS
FRZG RA (AGN AMTS VRY LGT...AND INCRSGLY SPOTTY THROUGH THE
ERY/MID MRNG HRS). WILL KP WINTER WX ADSVRY AS IS FOR NOW...AND
MONITOR TRENDS THROUGH ERY MRNG. ANY ACCUMS (ESP ICE)...GENLY AOB
0.01-0.02". SPOTTY LGT RA AND/OR DZ FM MIDDAY THROUGH THE AFTN
HRS...AGN QPF QUITE LGT (LESS THAN 0.05") THROUGHOUT.
HI TEMPS FM NR 32F FAR NW TO L40S FAR SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
HIGHER CONFIDENCE/PROB FOR PCPN TNGT FM SW TO NE AS LO PRES FM
THE CNTRL GULF STATES TRACKS NE THROUGH GA/SC/NC. INCRSD POPS TO
80-100% ACRS MUCH OF THE AREA OVRNGT...W/ 60-80% FAR NNE SECTIONS.
HI PROB (90-100% POPS) OVR ENTIRE FA SAT MRNG. THE LO REACHES OFF
THE VA CST SAT AFTN/EVE LEADING TO A GRADUAL LWRG OF POPS FM WSW
TO E (THOUGH CLDNS WILL HANG ON). STM TOTAL QPF RANGING FM
0.25-0.50" NW TO 1-1.5" SE. TEMPS HOLD NRLY STEADY OR ONLY RISE A
CPL/FEW DEGS F INLAND...WHILE CLOSE TO THE CST...ESP SE VA/NE
NC...TEMPS RISE INTO/THROUGH THE 40S. HI TEMPS SAT M40S NW TO
M/U50S SE VA/NE NC.
SLOLY DRYING OUT BY LT SAT NGT/ERY SUN. SFC HI PRES BUIDS TWD THE
RGN FM THE NW ON SUN LEADING TO SUBSTANTIAL CLRG (AND MNLY SUNNY)
AND MILD CONDS. HI TEMPS 50-55F N TO 55-60F S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE BUILDS IN FROM THE WEST ON SUNDAY WITH DRY CONDITIONS
INTO SUNDAY NIGHT. A NEGATIVELY TILTED UPPER LEVEL RIDGE AMPLIFIES
OVER THE REGION ON MONDAY IN RESPONSE TO A BROAD UPPER LEVEL TROUGH
DIGGING OVER THE CTRL PLAINS. WEAK ENERGY FLOWING AROUND THE BASE OF
THE AFOREMENTIONED TROUGH IS EXPECTED TO MOVE NE ACROSS THE SE
STATES AS SW FLOW DEVELOPS ALOFT. THIS ENERGY AND ASSOCIATED
PRECIPITATION (ALL RAIN) IS THEN EXPECTED TO MOVE THROUGH THE MID
ATLANTIC REGION MONDAY NIGHT INTO TUESDAY. THERE WERE INDICATIONS OF
A COASTAL LOW DEVELOPING TUESDAY NIGHT ONCE IT MOVES OVER THE WATER
AND THIS TREND HAS CONTINUED...HOWEVER THERE ARE NOW MORE ADVERSE
TIMING DIFFERENCES BTWN VARIOUS 12Z MODEL RUNS. WILL TREND THE
FORECAST BTWN THE TWO MODELS FOR THE TIME BEING. A BROAD UPPER
TROUGH BECOMES ANCHORED OVER THE NE CONUS THE REMAINDER OF THE
WEEK...KEEPING CONDITIONS COOL AND UNSETTLED.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
SHORTWV ENERGY WILL PUSH ACRS THE AREA THIS MORNG INTO EARLY THIS
AFTN...AND MAY BRING A MIX OF LIGHT SLEET...SNOW OR FREEZING RAIN.
OTHRWISE...CLDS WILL THICKEN AND LWR DURING TODAY...AS WINDS
BECOME ESE WELL AHEAD OF LO PRES DEVELOPING OVR THE GULF CST
STATES. MVFR/IFR CIGS/VSBYS THEN LIKELY THIS EVENG INTO SAT
NGT...AS THE LO MOVES UP ALNG AND JUST OFF THE CST...BRINGING
RAIN TO THE AREA. DRY/VFR CONDITIONS RETURN SUN INTO MON...AS
HI PRES BLDS IN FM THE W.
&&
.MARINE...
TIGHTENING PRESSURE GRADIENT BETWEEN THE HIGH OVER CANADA AND LOW
MOVING OVER THE THE NORTH ATLANTIC HAS CAUSED WINDS TO INCREASE TO
SCA CONDITIONS OVER THE BAY. INCLUDED BAY ZONES FROM WINDMILL
POINT TO THE MOUTH OF THE BAY IN A SHORT(UNTIL 06Z)SCA AS WINDS
WILL GUST TO AROUND 25 KT.
HIGH PRESSURE BUILDS IN FROM THE NW TONIGHT...BRINGING AN END TO SCA
NW WINDS OVER THE BAY AND COASTAL WATERS NORTH OF PARRAMORE
ISLAND BY LATE EVENING. WATERS BECOME QUIET AFTER MIDNIGHT AS NW
WINDS BECOME NRLY AND DIMINISH TO GENERALLY AOB 15 KT. ONSHORE
FLOW DEVELOPS ON FRI (AOB 10 KT) AS THE SFC HIGH SLIDES OFFSHORE
AND A COMPLEX LOW PRESSURE SYSTEM THE AREA FROM THE SW. A WINTRY
MIX OF PRECIPITATION IS EXPECTED FRI MORNING...TRANSITIONING TO
ALL RAIN DURING THE EARLY AFTN. WINDS BEING TO VEER TO THE S-SE
LATE FRI NIGHT/EARLY SAT MORNING AS THE ACTUAL LOW PRESSURE CENTER
MOVES INTO SRN WATERS...BRINGING WIDESPREAD MODERATE RAIN TO ALL
WATERS DURING THE DAY. ONGOING WAA PROCESSES AND STEADY RAIN WILL
LIKELY LIMIT MIXING OVER THE WATERS...HOWEVER SCA FLAGS ARE
POSSIBLE OVER THE SOUND...SRN CHES BAY...AND SRN COASTAL WATERS AS
THE LOW PASSES THROUGH THE REGION. BY SAT NIGHT...THE LOW MOVES
OFF THE MID ATLANTIC COAST AND DEEPENS INTO A COASTAL LOW THAT IS
EXPECTED TO TRACK NE UP THE ERN SEABOARD TWD MASSACHUSETTS. A
TIGHTENING PRESSURE GRADIENT LATE SAT NIGHT AND WEAK CAA MAY
RESULT IN SCA CONDITIONS OVER NRN PORTIONS OF CHES BAY AND COASTAL
WATERS...ESPECIALLY AS WINDS BECOME NW. FLAGS HAVE NOT BEEN ISSUED
FOR THIS SITUATION AND WILL NEED TO BE MONITORED. AS HIGH PRESSURE
BUILDS INTO THE REGION ON SUN...POTENTIAL SCA CONDITIONS WILL
DIMINISH AND WATERS WILL BECOME QUIET SUN NIGHT THROUGH MON.
&&
.TIDES/COASTAL FLOODING...
ESTOFS AND MDL GUIDANCE CONTINUE TO SHOW NEGATIVE ANOMALIES
OCCURRING DURING THE LOW TIDE CYCLE TODAY AND FRIDAY...SLOWLY
RISING TWD MLLW LEVELS INTO THE WEEKEND. TIDE LEVELS ARE STILL
RUNNING ABOUT ONE HALF FT TO POSSIBLY ONE FT BELOW MLLW.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NCZ012-013-030.
VA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ060-
065>067-079-080-087-088.
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
VAZ092.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
ANZ630>632-634-650-652.
&&
$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB
SHORT TERM...ALB
LONG TERM...BMD
AVIATION...TMG
MARINE...TMG
TIDES/COASTAL FLOODING...AKQ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1205 AM EST FRI FEB 22 2013
.SYNOPSIS...
ISSUED AT 330 PM EST THU FEB 21 2013
SNOW WILL SPREAD NORTHEAST ACROSS THE AREA OVERNIGHT INTO FRIDAY
MORNING. A QUICK 1 TO 2 INCHES OF SNOW MAY AFFECT THE FRIDAY MORNING
COMMUTE. THIS WILL BE FOLLOWED BY A TRANSITION TO FREEZING DRIZZLE
LATER IN THE DAY. A CHANCE OF WINTRY PRECIPITATION WILL PERSIST
THROUGH SATURDAY NIGHT. THE NEXT CHANCES FOR PRECIPITATION WILL BE
MONDAY NIGHT AND TUESDAY...WHEN A MIX OF RAIN AND SNOW IS EXPECTED.
TEMPERATURES WILL MODERATE NEXT WEEK WITH HIGHS REACHING THE UPPER
30S.
&&
.UPDATE...
ISSUED AT 1022 PM EST THU FEB 21 2013
NO CHANGES TO THE HEADLINES. REGIONAL RADAR SHOWS A BAND OF
SNOW...ON THE LEADING EDGE...AND FREEZING RAIN MOVING NORTH ACROSS
INDIANA. THE NRN FRINGE IS THINNING AS IT MOVES NORTH AND WILL
LIKELY TAKE A WHILE TO GET TO THE SRN CWA. STILL LOOKING FOR PCPN
TO BEGIN AFTER 08-09Z SOUTH OF I-94 AND MOVE NORTH.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 330 PM EST THU FEB 21 2013
WILL BE ISSUING A WINTER WEATHER ADVISORY FOR OUR SOUTHERN CWFA TO
ACCOUNT FOR POSSIBLE BRIEF INTENSE SNOWFALL DURING THE FRIDAY
MORNING COMMUTE. CALIBRATED SREF GUIDANCE SHOWS GREATER THAN 1 INCH
PER HOUR SNOWFALL PROBABILITIES ACROSS OUR SOUTHERN COUNTY WARNING
AREA IN THE 12-15Z TIMEFRAME FRIDAY. ALSO LATEST GRR SNOWTOOL
GUIDANCE FROM THE RAP SUGGESTS THAT 1"/HR RATES WILL BE POSSIBLE
AFTER 10Z. ADVISORY WILL BE COMING OUT SHORTLY.
AFTER THIS INITIAL BURST OF SNOWFALL...AGREE WITH THE PREVIOUS
DISCUSSION THAT IMPACTS SHOULD BE MINOR. THE RESPONSIBLE SYSTEM
CURRENTLY IN THE PLAINS WILL FILL AS IT SHEARS NORTHEAST. BEHIND THE
NARROW BUT POTENTIALLY INTENSE BAND OF WARM ADVECTION SNOW...ALL BUT
THE EXTREME NORTHERN PART OF THE FORECAST AREA DESATURATES IN THE
DGZ DURING THE LATE MORNING...MEANING A TRANSITION TO FREEZING
DRIZZLE AND THEN POSSIBLY DRIZZLE AS SURFACE TEMPERATURES WARM. ICE
ACCUMULATION IS EXPECTED TO BE MINIMAL... ESPECIALLY WITH THE
MITIGATING EFFECTS OF SNOW COVER...RESIDUAL SALT...AND DAYTIME
INSOLATION ALL DISCUSSED IN THE PREVIOUS AFD.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM EST THU FEB 21 2013
A HIGH PRESSURE RIDGE WILL PRODUCE DRY WX WITH SEASONABLY COOL
TEMPERATURES SUNDAY THROUGH SUNDAY NIGHT. LOW PRESSURE TRACKING NE
INTO OUR REGION WILL BRING A SLIGHT CHANCE FOR A MIX OF LIGHT RAIN
AND LIGHT SNOW AS EARLY AS MONDAY BASED ON 12Z GFS GUIDANCE.
HOWEVER THE MUCH BETTER CHANCE FOR MIXED PCPN SHOULD HOLD OFF UNTIL
LATE MONDAY NIGHT AND TUESDAY AS SUGGESTED BY THE SLOWER AND
PREFERRED ECMWF 12Z GUIDANCE SOLUTION (WHICH IS CONSISTENT WITH PCPN
TIMING FROM THE 00Z RUN).
TEMPS WILL UNDERGO A GRADUAL MODERATING TREND DURING THE EARLY TO
MIDDLE PORTION OF NEXT WEEK WITH MAX TEMPS EXPECTED TO REACH THE
UPPER 30S TO LOWER 40S BY TUESDAY AND WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1204 AM EST FRI FEB 22 2013
FORECAST THINKING HAS NOT CHANGED MUCH FROM THE 00Z SET OF TAFS.
STILL EXPECTING MVFR CEILINGS TO FILL IN THE REMAINDER OF THE
NIGHT WITH SNOW BREAKING OUT AROUND 09Z AT KAZO. THE SNOW WILL
SPREAD NORTHEAST BETWEEN 09Z AND 15Z. THE BAND OF SNOW WILL HAVE
BURSTS THAT WILL BE HEAVY AT TIMES...DROPPING VSBY/S POSSIBLY TO
AROUND A HALF MILE AT TIMES. THE SNOW WILL EXIT THE TAF SITES
BETWEEN 14Z-15Z WITH FREEZING DRIZZLE PERSISTING INTO THE
AFTERNOON HOURS. THE IFR CEILINGS THAT WILL ACCOMPANY THE SNOW
WILL LINGER INTO THE EVENING HOURS.
&&
.MARINE...
ISSUED AT 359 PM EST THU FEB 21 2013
AFTER FURTHER CONSIDERATION...ISSUED A NEW SMALL CRAFT ADVISORY BEGINNING
TONIGHT TO ACCOUNT FOR STRENGTHENING EAST WINDS TOWARDS MORNING. ALTHOUGH
WAVE GROWTH WILL BE LIMITED SOMEWHAT BY POOR FETCH...SUSTAINED WINDS
WELL IN EXCESS OF 20 KTS TOWARDS SUNRISE WILL GREATLY INCREASE THE
HAZARD.
&&
.HYDROLOGY...
ISSUED AT 330 PM EST THU FEB 21 2013
WITH ADDITIONAL QPF EXPECTED TO STAY WELL UNDER HALF AN INCH...THERE
ARE NO CONCERNS AT THIS TIME.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY FROM 4 AM TO 1 PM EST FRIDAY FOR MIZ050-
056>059-064>067-071>074.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST SATURDAY FOR LMZ844>849.
&&
$$
UPDATE...93
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...TJT
MARINE...TJT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1227 PM CST FRI FEB 22 2013
.UPDATED FOR 18Z AVIATION DISCUSSION...
&&
.DISCUSSION...
/ISSUED AT 850 AM CST FRI FEB 22 2013/
EMBEDDED VORT MAXI WITHIN THE UPPER LEVEL LOW HAS RESULTED IN AN
AREA OF FRONTOGENESIS ALONG AND EAST OF THE MISSISSIPPI RIVER AS
IDENTIFIED BY THE RAP13 SHORT RANGE MODEL. SURFACE OBS INDICATED
VISBYS OF 1/2MI UNDER THIS BAND...SO USED THE HRRR AND RAP TRENDS
TO INCREASE SNOW AMOUNTS TODAY...AND ADD HEAVY SNOW WORDING THIS
MORNING.
.PREVIOUS DISCUSSION...
/ISSUED AT 335AM CST FRI FEB 22 2013/
THIS MORNING AND TODAY...SNOW HAS OVERTAKEN SOUTHERN MINNESOTA
AND WESTERN WISCONSIN EARLY THIS MORNING. SURFACE LOW PRESSURE
CENTER OVER NORTH CENTRAL MISSOURI THIS MORNING WILL CONTINUE
LIFTING NORTHEAST THROUGH EASTERN IOWA AND INTO CENTRAL WISCONSIN
BY THIS EVENING. THE HEAVIEST SNOW FALL ACROSS THE AREA WILL FALL
FROM NOW THROUGH MID MORNING...AND WILL MAKE FOR A SLOW COMMUTE
THIS MORNING. THE WEAKENING SURFACE LOW WILL MAINTAIN A RELATIVELY
RELAXED PRESSURE GRADIENT...MEANING THE WIND WILL WILL BE
RELATIVELY LIGHT SO BLOWING SNOW WILL NOT BE AN ISSUE TODAY.
SNOWFALL TOTALS WERE TWEAKED VERY SLIGHTLY FROM THE PREVIOUS
FORECAST...WITH 3 TO 6 INCHES STILL EXPECTED ACROSS THE SOUTHERN
THIRD OF MINNESOTA...AND INTO PARTS OF WEST CENTRAL
WISCONSIN...WITH GENERALLY 1 TO 3 INCHES TO THE NORTHWEST. THE
SNOWFALL TAPER OFF AND BECOME VERY LIGHT THIS AFTERNOON AND LINGER
INTO TONIGHT.
THE LOW PIVOTS OVER THE GREAT LAKES INTO SATURDAY. WEAK
LIFT AND RESIDUAL MOISTURE ON ITS WESTERN PERIPHERY WILL YIELD
LINGERING LIGHT SNOW FROM NORTH/EAST CENTRAL MN INTO WEST CENTRAL
WISCONSIN UNTIL MID-DAY SATURDAY. ADDITIONAL SNOWFALL AMOUNTS
DURING THAT TIME FRAME OF A DUSTING TO ONE INCH ARE POSSIBLE. TEMPERATURES
WILL REMAIN ON THE MILD SIDE...WITH SATURDAY MORNING LOWS RANGING
FROM 5 TO 15...AND HIGHS MAINLY FROM 25 TO 30 DEGREES.
SATURDAY NIGHT AND SUNDAY WILL BE THE BENIGN TIME FRAME DURING THE
FORECAST PERIOD...AS WEAK MID LEVEL RIDGING BUILDS LOCALLY AS AN
UPSTREAM TROUGH DIGS OVER THE FOUR CORNERS REGION. MODEL
SOLUTIONS CONTINUE TO EXHIBIT POOR AGREEMENT WITH RESPECT TO THE
EVOLUTION OF THIS FEATURE. THE ECMWF WAS THE PREFERRED MODEL THIS
MORNING...LARGELY DUE TO ITS CONSISTENCY. THIS FAVORS A SLIGHTLY
WEAKER SYSTEM WITH A PROLONGED LIGHTER INTENSITY SNOWFALL
EVENT...OVER THE STRONGER GFS WITH HIGHER RATES OF SNOWFALL. HAVE
MAINTAINED 30-50 POPS IN THE SUNDAY NIGHT THROUGH TUESDAY NIGHT
WINDOW...WITH 20S LINGERING ON WEDNESDAY. HAVE ALSO KEPT THE
HIGHER CHANCES IN SOUTHERN MN...IN CLOSER PROXIMITY TO THE SURFACE
TROUGH. HIGH TEMPERATURES NEXT WEEK WILL REMAIN SLIGHTLY BELOW
NORMAL...WITH HIGHS IN THE UPPER 20S TO MID 30S. CONVERSELY...MILD
LOWS IN THE MID TEENS TO LOWER 20S ARE ANTICIPATED.
&&
.AVIATION.../18Z TAF ISSUANCE/
MVFR CEILINGS WILL PERSIST THROUGH THE FORECAST PERIOD...WITH
LIGHT SNOW SHOWERS DIMINISHING THIS AFTERNOON/EVENING. BOTH RADAR
AND SATELLITE TRENDS DEPICT SNOW BECOMING LIGHTER IN INTENSITY
AND MORE ISOLATED IN COVERAGE. FORECAST GUIDANCE SHOWS SURFACE LOW
LIFTING NORTHEAST...WITH HIGH PRESSURE BUILDING IN OVERNIGHT.
WINDS WILL BE LIGHT...AND THE LOW LEVEL MOISTURE SHOULD HANG
AROUND AS AN MVFR CLOUD DECK...WITH SOME THINNING EXPECTED ON
SATURDAY AFTERNOON.
KMSP...A FEW LIGHT SNOW SHOWERS WILL LINGER ACROSS THE REGION THIS
AFTERNOON AND COULD BRIEFLY TAKE VISBYS DOWN TO AROUND 2SM. A
LIGHTER BAND OF SNOW CURRENTLY ACROSS WESTERN MINNESOTA COULD
IMPACT KMSP THIS EVENING...BUT AT THIS TIME AGREE WITH THE
SHORT TERM GUIDANCE THAT THIS WILL FALL APART AND MOVE NORTHWARD
INTO NORTH CENTRAL MINNESOTA. TONIGHT CEILINGS SHOULD LOWER BELOW
THE CRITICAL 1700FT THRESHOLD...BUT LIFT AGAIN BY SATURDAY MID
MORNING.
/OUTLOOK FOR KMSP/
SUN...VFR/MVFR WITH -SN AND MVFR/IFR VISBY/CIGS POSSIBLE LATE.
WINDS SW AT 05KTS.
MON...MVFR WITH -SN POSSIBLE. WINDS NNE AT 05KTS.
TUE...MVFR WITH -SN POSSIBLE. WINDS N AT N AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR ANOKA-
CARVER-CHISAGO-DAKOTA-GOODHUE-HENNEPIN-ISANTI-MCLEOD-MEEKER-
RAMSEY-RICE-SCOTT-SHERBURNE-WASHINGTON-WRIGHT.
WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR BARRON-
CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX.
&&
$$
LS/JRB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
850 AM CST FRI FEB 22 2013
.UPDATED DISCUSSION FOR INCREASED SNOW AMOUNTS...
EMBEDDED VORT MAXI WITHIN THE UPPER LEVEL LOW HAS RESULTED IN AN
AREA OF FRONTOGENESIS ALONG AND EAST OF THE MISSISSIPPI RIVER AS
IDENTIFIED BY THE RAP13 SHORT RANGE MODEL. SURFACE OBS INDICATED
VISBYS OF 1/2MI UNDER THIS BAND...SO USED THE HRRR AND RAP TRENDS
TO INCREASE SNOW AMOUNTS TODAY...AND ADD HEAVY SNOW WORDING THIS
MORNING.
.PREVIOUS DISCUSSION...
/ISSUED AT 335AM CST FRI FEB 22 2013/
THIS MORNING AND TODAY...SNOW HAS OVERTAKEN SOUTHERN MINNESOTA
AND WESTERN WISCONSIN EARLY THIS MORNING. SURFACE LOW PRESSURE
CENTER OVER NORTH CENTRAL MISSOURI THIS MORNING WILL CONTINUE
LIFTING NORTHEAST THROUGH EASTERN IOWA AND INTO CENTRAL WISCONSIN
BY THIS EVENING. THE HEAVIEST SNOW FALL ACROSS THE AREA WILL FALL
FROM NOW THROUGH MID MORNING...AND WILL MAKE FOR A SLOW COMMUTE
THIS MORNING. THE WEAKENING SURFACE LOW WILL MAINTAIN A RELATIVELY
RELAXED PRESSURE GRADIENT...MEANING THE WIND WILL WILL BE
RELATIVELY LIGHT SO BLOWING SNOW WILL NOT BE AN ISSUE TODAY.
SNOWFALL TOTALS WERE TWEAKED VERY SLIGHTLY FROM THE PREVIOUS
FORECAST...WITH 3 TO 6 INCHES STILL EXPECTED ACROSS THE SOUTHERN
THIRD OF MINNESOTA...AND INTO PARTS OF WEST CENTRAL
WISCONSIN...WITH GENERALLY 1 TO 3 INCHES TO THE NORTHWEST. THE
SNOWFALL TAPER OFF AND BECOME VERY LIGHT THIS AFTERNOON AND LINGER
INTO TONIGHT.
THE LOW PIVOTS OVER THE GREAT LAKES INTO SATURDAY. WEAK
LIFT AND RESIDUAL MOISTURE ON ITS WESTERN PERIPHERY WILL YIELD
LINGERING LIGHT SNOW FROM NORTH/EAST CENTRAL MN INTO WEST CENTRAL
WISCONSIN UNTIL MID-DAY SATURDAY. ADDITIONAL SNOWFALL AMOUNTS
DURING THAT TIME FRAME OF A DUSTING TO ONE INCH ARE POSSIBLE. TEMPERATURES
WILL REMAIN ON THE MILD SIDE...WITH SATURDAY MORNING LOWS RANGING
FROM 5 TO 15...AND HIGHS MAINLY FROM 25 TO 30 DEGREES.
SATURDAY NIGHT AND SUNDAY WILL BE THE BENIGN TIME FRAME DURING THE
FORECAST PERIOD...AS WEAK MID LEVEL RIDGING BUILDS LOCALLY AS AN
UPSTREAM TROUGH DIGS OVER THE FOUR CORNERS REGION. MODEL
SOLUTIONS CONTINUE TO EXHIBIT POOR AGREEMENT WITH RESPECT TO THE
EVOLUTION OF THIS FEATURE. THE ECMWF WAS THE PREFERRED MODEL THIS
MORNING...LARGELY DUE TO ITS CONSISTENCY. THIS FAVORS A SLIGHTLY
WEAKER SYSTEM WITH A PROLONGED LIGHTER INTENSITY SNOWFALL
EVENT...OVER THE STRONGER GFS WITH HIGHER RATES OF SNOWFALL. HAVE
MAINTAINED 30-50 POPS IN THE SUNDAY NIGHT THROUGH TUESDAY NIGHT
WINDOW...WITH 20S LINGERING ON WEDNESDAY. HAVE ALSO KEPT THE
HIGHER CHANCES IN SOUTHERN MN...IN CLOSER PROXIMITY TO THE SURFACE
TROUGH. HIGH TEMPERATURES NEXT WEEK WILL REMAIN SLIGHTLY BELOW
NORMAL...WITH HIGHS IN THE UPPER 20S TO MID 30S. CONVERSELY...MILD
LOWS IN THE MID TEENS TO LOWER 20S ARE ANTICIPATED.
&&
.AVIATION.../12Z TAF ISSUANCE/
WIDESPREAD SNOWFALL HAS SPREAD ACROSS THE REGION EARLY THIS
MORNING...IMPACTING ALL TAF SITES IN THE MPX FORECAST AREA.
HEAVIEST ACCUMULATIONS ARE EXPECTED AT EAU CLAIRE WITH THE LEAST
OCCURRING AT ALEXANDRIA. SNOW WILL CONTINUE TO FALL MOST OF THE
DAY ACROSS THE REGION...BUT SHOULD RAPIDLY TAPER THIS AFTERNOON AS
BEST FORCING IS SHUNTED OFF TO THE NORTH AND EAST. HOWEVER...THERE
IS CONCERN THAT A DEFORMATION BAND OF SNOW WILL IMPACT
AXN...RWF...AND STC THIS AFTERNOON...SO THERE MAY BE TEMPORARY
PERIODS THIS AFTERNOON WHEN VSBYS FALL BELOW THOSE CURRENTLY
ADVERTISED IN THE TAF AT THOSE SITES. DID NOT FEEL CONFIDENT ENOUGH
IN THE INTENSITY AND EXACT PLACEMENT SPATIALLY AND TEMPORALLY TO
INTRODUCE A TEMPO VSBY RESTRICTION AT THIS TIME...THIS WILL BE
MONITORED CLOSELY TODAY. WINDS ARE EXPECTED TO BE GENERALLY LIGHT
OUT OF THE NORTHEAST FOR MUCH OF THE DAY...BEFORE SHIFTING NORTH
THIS AFTERNOON...THEN NORTHWESTERLY TONIGHT AS THE SURFACE LOW
MAKES ITS WAY FROM NORTHERN MISSOURI THIS MORNING...TOWARD CENTRAL
WISCONSIN TONIGHT.
KMSP...THE HEAVIEST SNOW AT MSP IS BEHIND US AT THIS POINT...BUT
LIGHT SNOW WILL CONTINUE FOR MOST OF THE DAY. WE STILL EXPECT
ANOTHER INCH OR TWO OF ACCUMULATION AT THE AIRFIELD TODAY.
CEILINGS HAVE BEEN INCONSISTENT THIS MORNING...AND DOWNSTREAM
OBSERVATIONS SHOW A RANGE OF CEILING HEIGHTS FROM 500 FEET TO 2500
FEET. EXPECT CEILINGS TO DROP TO NEAR 1000 FEET AND SEE MINIMAL
IMPROVEMENT THROUGH THE TAF PERIOD. INITIAL NORTHEAST WIND WILL
TURN NORTHWEST BY EVENING...AND WESTERLY NEAR MIDNIGHT TONIGHT.
/OUTLOOK FOR KMSP/
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR ANOKA-
BLUE EARTH-BROWN-CARVER-CHIPPEWA-CHISAGO-DAKOTA-FARIBAULT-
FREEBORN-GOODHUE-HENNEPIN-ISANTI-KANDIYOHI-LE SUEUR-MARTIN-
MCLEOD-MEEKER-NICOLLET-RAMSEY-REDWOOD-RENVILLE-RICE-SCOTT-
SHERBURNE-SIBLEY-STEELE-WASECA-WASHINGTON-WATONWAN-WRIGHT-
YELLOW MEDICINE.
WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR BARRON-
CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX.
&&
$$
LS/JRB
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
106 PM EST FRI FEB 22 2013
.SYNOPSIS...
DRY WEATHER IS EXPECTED ACROSS THE NORTH COUNTRY TODAY AND
TONIGHT WITH A RETURN TO MORE SEASONAL TEMPERATURES. OUR AREA
WILL BE IN BETWEEN TWO LOW PRESSURE SYSTEMS THIS WEEKEND...BUT
BOTH WILL BE CLOSE ENOUGH TO SPREAD LIGHT TO MODERATE SNOW INTO
THE REGION SATURDAY AND CONTINUE RIGHT THROUGH SUNDAY. AT THIS
TIME A GENERAL 3 TO 7 INCHES OF SNOW CAN BE EXPECTED.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1135 AM EST FRIDAY...LINGERING LOW CLOUDS CONTINUE TO
PERSIST ACROSS NORTHERN VERMONT AND FAR NORTHERN NEW YORK. FELT
THAT THE 15Z RAP HAS CAPTURED THE EXTENT OF CLOUD COVER THE BEST
AND GENERALLY FOLLOWED ITS DEPICTION OF VERY GRADUAL THINNING AND
DISSIPATION DURING THE AFTERNOON HOURS. AT THE SAME
TIME...INCREASING BUT THINNING HIGH CLOUDS CONTINUE TO PUSH INTO
CENTRAL AND WESTERN NEW YORK. THEREFORE A PARTLY-MOSTLY CLOUDY
AFTERNOON ANTICIPATED WITH THE MOST SUN IN BETWEEN THESE TWO CLOUD
CONCENTRATIONS ACROSS THE SOUTHEAST ADIRONDACKS AND
CENTRAL/SOUTHERN VERMONT. TEMPERATURES HAVE REBOUNDED NICELY FROM
THIS MORNINGS LOWS AND REMAIN ON TRACK TO REACH THE MID 30S IN
MOST LOCATIONS...WITH SOME LOWER 30S HANGING ON IN THE ADIRONDACKS
AND FAR NORTHEAST KINGDOM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AS OF 348 AM EST FRIDAY...DRY WEATHER CONTINUES TONIGHT...BUT
MORE CLOUDS RETURN ON SATURDAY AND SKIES WILL REMAIN CLOUDY RIGHT
THROUGH SUNDAY. THIS IS IN RESPONSE TO DEEPER MOISTURE MOVING
INTO THE REGION ON SOUTHWEST FLOW ALOFT. ESSENTIALLY OUR AREA
WILL BE IN BETWEEN TWO LOW PRESSURE SYSTEMS...ONE OVER THE
EASTERN GREAT LAKES ON SATURDAY AND ONE DEVELOPING OFFSHORE SOUTH
OF NEW JERSEY AND MOVES SOUTH OF CAPE COD ON SUNDAY.
HOWEVER...OUR AREA WILL BE IN AREA OF LARGE SCALE
ASCENT/DIFFLUENT FLOW SATURDAY AFTERNOON THROUGH SUNDAY AS
EASTERN GREAT LAKES UPPER LOW EVENTUALLY MOVES INTO THE AREA ON
SUNDAY. THUS LOOKING AT WIDESPREAD LIGHT SNOWS OVER A LONGER
DURATION OF TIME...WHICH WILL LEAD TO ACCUMULATING SNOWS. THERE
MAY BE SOME BRIEF PERIODS OF MODERATE SNOW...ESPECIALLY OVER
SOUTH CENTRAL VERMONT LATER SATURDAY NIGHT AND SUNDAY MORNING. AT
THIS TIME...TOTAL SNOWFALL FOR THE 48 HOUR PERIOD FROM SATURDAY
THROUGH SUNDAY LOOKS TO BE IN THE 2 TO 5 INCH RANGE ACROSS
NORTHERN NEW YORK AND 3 TO 7 INCHES ACROSS VERMONT. OF NOTE WILL
BE THE GREATER WATER CONTENT IN THE SNOW AND THUS LOOKING AT A
WETTER SNOW. THERMAL PROFILE SUGGESTS ONLY THE NEAR SURFACE WILL
GET ABOVE FREEZING...THUS THE RAIN THREAT WILL BE CONFINED TO
SATURDAY AFTERNOON AND ACROSS PARTS OF THE CHAMPLAIN AND SAINT
LAWRENCE VALLEYS. OTHERWISE LOOKING AT SNOW FOR SATURDAY NIGHT
INTO SUNDAY. HIGHS ON SATURDAY WILL BE IN THE 30S AND IN THE
LOWER TO MID 30S ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 348 AM EST FRIDAY...SNOW SHOWERS CONTINUE SUNDAY
NIGHT...ESPECIALLY IN THE MOUNTAINS...AS COASTAL LOW MOVES AWAY
FROM THE REGION AND NORTHERN STREAM LOW DRIFTS EASTWARD AS IT
WEAKENS. RIDGE OF HIGH PRESSURE WILL BUILD OVER THE NORTH COUNTRY
MONDAY AND MONDAY NIGHT. NEXT LOW PRESSURE SYSTEM TO IMPACT THE
NORTH COUNTRY APPROACHES OUR FORECAST AREA TOWARDS THE MIDDLE OF
THE WEEK. GFS CONTINUES TO BE FASTER BRINGING PRECIPITATION INTO
OUR FORECAST AREA ON TUESDAY...WHILE THE ECMWF HOLDS OFF TILL
TUESDAY NIGHT. BOTH MODELS DEPICT TWO LOW PRESSURE SYSTEMS
PHASING INTO ONE LARGE LOW PRESSURE SYSTEM...AND LINGERING OVER
THE REGION THROUGH THE END OF THE PERIOD. STILL A LOT OF
UNCERTAINTY DUE TO LACK OF MODEL- TO- MODEL AND RUN-TO-RUN
CONSISTENCY. UNFORTUNATELY HAVE CHANCE POPS MENTIONED FROM
TUESDAY THROUGH THURSDAY DUE TO TIMING DIFFERENCES OF THE GFS AND
ECMWF. HOPEFULLY MODELS WILL COME INTO BETTER AGREEMENT WITH
REGARDS TO THIS SYSTEM SOON.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 18Z SATURDAY...A RIDGE OF HIGH PRESSURE OVER THE REGION AT 18Z
FRIDAY WILL MOVE EAST TO THE CANADIAN MARITIMES BY 06Z SATURDAY. A WARM
FRONT WILL APPROACH THE REGION AFTER 06Z SATURDAY THROUGH 18Z SATURDAY.
SURFACE OBSERVATIONS AND VISIBLE SATELLITE LOOP SHOWING LOW CLOUDS ACROSS
THE NORTHERN PORTION OF THE FORECAST AREA AS OF 18Z FRIDAY...WITH
SOME AREAS OF MVFR CEILINGS. WIND FLOW AT THE SURFACE AND ALOFT IS LIGHT
DUE TO THE HIGH PRESSURE AREA OVER THE REGION...SO HAVE GONE WITH
A PERSISTANCE FORECAST FOR THOSE AREAS THAT ARE NOW IN THE LOW OVERCAST.
MODEL GUIDANCE SHOWING SOME LIGHT PRECIPITATION MAY BREAK OUT OVER
THE REGION AFTER 06Z SATURDAY THROUGH 18Z SATURDAY. FEEL THIS WILL
BE QUITE LIGHT AND WILL NOT CAUSE ANY RESTRICTIONS TO VISIBILITY
AT THIS TIME...SO HAVE NOT INCLUDED THIS IN THE TAF FORECASTS AT
THIS TIME.
OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY...
18Z SATURDAY THROUGH 12Z MONDAY...AREAS OF MVFR/IFR IN LIGHT SNOW
THROUGH THE PERIOD.
VFR CONDITIONS EXPECTED FROM 12Z MONDAY THROUGH 00Z WEDNESDAY...AS
A RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION.
00Z WEDNESDAY THROUGH 00Z THURSDAY...DEVELOPING IFR/MVFR IN SNOW...RAIN
AND MIXED PRECIPITATION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...EVENSON
NEAR TERM...MUCCILLI
SHORT TERM...EVENSON
LONG TERM...NEILES
AVIATION...WGH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1142 AM EST FRI FEB 22 2013
.SYNOPSIS...
DRY WEATHER IS EXPECTED ACROSS THE NORTH COUNTRY TODAY AND
TONIGHT WITH A RETURN TO MORE SEASONAL TEMPERATURES. OUR AREA
WILL BE IN BETWEEN TWO LOW PRESSURE SYSTEMS THIS WEEKEND...BUT
BOTH WILL BE CLOSE ENOUGH TO SPREAD LIGHT TO MODERATE SNOW INTO
THE REGION SATURDAY AND CONTINUE RIGHT THROUGH SUNDAY. AT THIS
TIME A GENERAL 3 TO 7 INCHES OF SNOW CAN BE EXPECTED.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1135 AM EST FRIDAY...LINGERING LOW CLOUDS CONTINUE TO
PERSIST ACROSS NORTHERN VERMONT AND FAR NORTHERN NEW YORK. FELT
THAT THE 15Z RAP HAS CAPTURED THE EXTENT OF CLOUD COVER THE BEST
AND GENERALLY FOLLOWED ITS DEPICTION OF VERY GRADUAL THINNING AND
DISSIPATION DURING THE AFTERNOON HOURS. AT THE SAME
TIME...INCREASING BUT THINNING HIGH CLOUDS CONTINUE TO PUSH INTO
CENTRAL AND WESTERN NEW YORK. THEREFORE A PARTLY-MOSTLY CLOUDY
AFTERNOON ANTICIPATED WITH THE MOST SUN IN BETWEEN THESE TWO CLOUD
CONCENTRATIONS ACROSS THE SOUTHEAST ADIRONDACKS AND
CENTRAL/SOUTHERN VERMONT. TEMPERATURES HAVE REBOUNDED NICELY FROM
THIS MORNINGS LOWS AND REMAIN ON TRACK TO REACH THE MID 30S IN
MOST LOCATIONS...WITH SOME LOWER 30S HANGING ON IN THE ADIRONDACKS
AND FAR NORTHEAST KINGDOM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AS OF 348 AM EST FRIDAY...DRY WEATHER CONTINUES TONIGHT...BUT
MORE CLOUDS RETURN ON SATURDAY AND SKIES WILL REMAIN CLOUDY RIGHT
THROUGH SUNDAY. THIS IS IN RESPONSE TO DEEPER MOISTURE MOVING
INTO THE REGION ON SOUTHWEST FLOW ALOFT. ESSENTIALLY OUR AREA
WILL BE IN BETWEEN TWO LOW PRESSURE SYSTEMS...ONE OVER THE
EASTERN GREAT LAKES ON SATURDAY AND ONE DEVELOPING OFFSHORE SOUTH
OF NEW JERSEY AND MOVES SOUTH OF CAPE COD ON SUNDAY.
HOWEVER...OUR AREA WILL BE IN AREA OF LARGE SCALE
ASCENT/DIFFLUENT FLOW SATURDAY AFTERNOON THROUGH SUNDAY AS
EASTERN GREAT LAKES UPPER LOW EVENTUALLY MOVES INTO THE AREA ON
SUNDAY. THUS LOOKING AT WIDESPREAD LIGHT SNOWS OVER A LONGER
DURATION OF TIME...WHICH WILL LEAD TO ACCUMULATING SNOWS. THERE
MAY BE SOME BRIEF PERIODS OF MODERATE SNOW...ESPECIALLY OVER
SOUTH CENTRAL VERMONT LATER SATURDAY NIGHT AND SUNDAY MORNING. AT
THIS TIME...TOTAL SNOWFALL FOR THE 48 HOUR PERIOD FROM SATURDAY
THROUGH SUNDAY LOOKS TO BE IN THE 2 TO 5 INCH RANGE ACROSS
NORTHERN NEW YORK AND 3 TO 7 INCHES ACROSS VERMONT. OF NOTE WILL
BE THE GREATER WATER CONTENT IN THE SNOW AND THUS LOOKING AT A
WETTER SNOW. THERMAL PROFILE SUGGESTS ONLY THE NEAR SURFACE WILL
GET ABOVE FREEZING...THUS THE RAIN THREAT WILL BE CONFINED TO
SATURDAY AFTERNOON AND ACROSS PARTS OF THE CHAMPLAIN AND SAINT
LAWRENCE VALLEYS. OTHERWISE LOOKING AT SNOW FOR SATURDAY NIGHT
INTO SUNDAY. HIGHS ON SATURDAY WILL BE IN THE 30S AND IN THE
LOWER TO MID 30S ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 348 AM EST FRIDAY...SNOW SHOWERS CONTINUE SUNDAY
NIGHT...ESPECIALLY IN THE MOUNTAINS...AS COASTAL LOW MOVES AWAY
FROM THE REGION AND NORTHERN STREAM LOW DRIFTS EASTWARD AS IT
WEAKENS. RIDGE OF HIGH PRESSURE WILL BUILD OVER THE NORTH COUNTRY
MONDAY AND MONDAY NIGHT. NEXT LOW PRESSURE SYSTEM TO IMPACT THE
NORTH COUNTRY APPROACHES OUR FORECAST AREA TOWARDS THE MIDDLE OF
THE WEEK. GFS CONTINUES TO BE FASTER BRINGING PRECIPITATION INTO
OUR FORECAST AREA ON TUESDAY...WHILE THE ECMWF HOLDS OFF TILL
TUESDAY NIGHT. BOTH MODELS DEPICT TWO LOW PRESSURE SYSTEMS
PHASING INTO ONE LARGE LOW PRESSURE SYSTEM...AND LINGERING OVER
THE REGION THROUGH THE END OF THE PERIOD. STILL A LOT OF
UNCERTAINTY DUE TO LACK OF MODEL- TO- MODEL AND RUN-TO-RUN
CONSISTENCY. UNFORTUNATELY HAVE CHANCE POPS MENTIONED FROM
TUESDAY THROUGH THURSDAY DUE TO TIMING DIFFERENCES OF THE GFS AND
ECMWF. HOPEFULLY MODELS WILL COME INTO BETTER AGREEMENT WITH
REGARDS TO THIS SYSTEM SOON.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 12Z SATURDAY...CONDITIONS IMPROVE THROUGH THE DAY WITH
JUST SCT CLOUDS AFTER 14Z AS HIGH PRESSURE MOVES ACROSS THE
REGION. WINDS LESS THAN 10 KTS THROUGH THE PERIOD. WINDS PICK UP
OUT OF THE SOUTHEAST SATURDAY MORNING AND CLOUDS WILL INCREASE
AND LOWER AFTER 06Z.
OUTLOOK 12Z SATURDAY THROUGH TUESDAY... SATURDAY THERE WILL BE
SOME SNOW SHOWERS WITH MVFR CONDITIONS AT TIMES. STEADIER SNOW
WITH PERIODS OF IFR EXPECTED SATURDAY NIGHT/SUNDAY. MONDAY WILL
SEE A RETURN TO HIGH PRESSURE AND VFR CONDITIONS. TUESDAY WILL
HAVE INCREASING CLOUDS WITH SNOW/RAIN POSSIBLE ALONG WITH MVFR/IFR
CONDITIONS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...EVENSON
NEAR TERM...MUCCILLI
SHORT TERM...EVENSON
LONG TERM...NEILES
AVIATION...NEILES
AREA FORECAST DISCUSSION
NWS BUFFALO NY
655 AM EST FRI FEB 22 2013
.SYNOPSIS...
LOW PRESSURE WILL APPROACH THE AREA FROM THE OHIO VALLEY THROUGH
TONIGHT...BRINGING THE CHANCE FOR A LIGHT WINTRY MIX OF
PRECIPITATION THIS AFTERNOON THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER LOW CROSSING THE NEBRASKA/IOWA BORDER EARLY THIS MORNING
WILL MOVE NORTHEAST INTO SOUTHERN WISCONSIN BY THIS EVENING...
REACHING THE UPPER PENINSULA OF MICHIGAN BY LATE TONIGHT. THE
ACCOMPANYING LOW LEVEL THETA-E RIDGE ON THE NOSE OF A 50 KNOT PLUS
SOUTHERLY LOW LEVEL JET CURRENTLY FOCUSING A BAND OF PRECIPITATION
ACROSS SOUTHERN LOWER MICHIGAN INTO CENTRAL OHIO. LATEST HRRR RUNS
SEEMS TO HAVE A DECENT HANDLE ON SPEED OF APPROACHING
PRECIPITATION WHICH SHOWS LITTLE DEVIATION FROM PREVIOUS FORECAST
TIMING...PLACING THE LEADING EDGE OF WEAKENING PRECIPITATION
SHIELD INTO SOUTHWEST NEW YORK AROUND NOON TIME. EVAPORATIONAL
COOLING AFFECTS WILL MORE THAN LIKELY RESULT IN PRECIPITATION TYPE
AS PREDOMINANTLY SNOW...ALTHOUGH PORTIONS OF THE SOUTHERN TIER
COULD POTENTIAL EXPERIENCE SUFFICIENT LOW LEVEL WARM AIR ADVECTION
FOR PRECIPITATION TO CHANGE TO SLEET/FREEZING RAIN BRIEFLY BEFORE
MID LEVEL DRY SLOT MOVES IN. THE OVERALL SYSTEM TAKING ON A SPLIT
PATTERN AS THE MAIN UPPER LEVEL SUPPORT LIFTS NORTH AND WEST OF
THE AREA INTO THE UPPER LAKES...WHILE THE PRIMARY PLUME OF DEEP
MOISTURE SLIDES OFF TO THE SOUTH AND EAST INTO THE MID ATLANTIC
STATES. THIS WILL LIKELY GREATLY LIMIT THE PRECIPITATION POTENTIAL
ACROSS WESTERN NEW YORK WITH ONLY LIGHT AMOUNTS EXPECTED...WITH
EVEN THE POTENTIAL FOR SOME AREAS NOT RECEIVING ANY MEASURABLE
PRECIPITATION AT ALL. AFTER THE DRY SLOT MOVES THROUGH THE AREA
TONIGHT...LINGERING LOW LEVEL WARM AIR ADVECTION COMBINED WITH
SATURATED LOW LEVELS MAY RESULT IN A PERIOD OF FREEZING DRIZZLE
ACROSS THE AREA BEFORE LOW LEVELS DRY OUT A BIT AND THE WARM AIR
ADVECTION DIMINISHES. EVEN AT THIS STAGE OF THE FORECAST TOO MANY
UNCERTAINTIES TO ISSUE HEADLINES...ALTHOUGH HEADLINES MAY
EVENTUALLY BE NEEDED FOR PORTIONS OF THE AREA AS THE EVENT UNFOLDS.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
ON SATURDAY...THE LOW OVER THE GREAT LAKES WILL MOVE INTO SOUTHERN
ONTARIO AND WEAKEN AS THE COASTAL LOW MOVING NORTHEAST NEAR THE
CAROLINA COAST GATHERS STRENGTH OFFSHORE. THIS WILL MAINTAIN A SPLIT
IN THE PRECIP FIELD WITH MOST PRECIP NORTH AND SOUTH OF THE FORECAST
AREA...BUT INCREASING POPS OVER CENTRAL AND NORTHERN NY SATURDAY
AFTERNOON AND EVENING ASSOCIATED WITH GREAT LAKES/ONTARIO LOW`S COLD
FRONT INTERCEPTING WRAP AROUND MOISTURE FROM THE GATHERING STORM
ALONG THE COAST.
THE PRECIP TYPE WILL BE A WINTRY MIX IN THE MORNING WITH A CHANCE OF
SNOW...FREEZING RAIN AND SLEET FOR THE SOUTHERN TIER AND EASTERN
LAKE ONTARIO COUNTIES...AND PLAIN RAIN FOR THE WARMER LOWER
ELEVATIONS ALONG THE LAKE PLAINS SOUTH OF LAKE ONTARIO AND CLOSER TO
LAKE ERIE. THE PRECIP SHOULD TRANSITION TO ALL RAIN BY THE AFTERNOON
AS TEMPS CLIMB TO THE MID 30S TO LOWER 40S.
MID LEVEL MOISTURE BECOMES SCARCE FROM WEST TO EAST THROUGH THE LATE
AFTERNOON AND EVENING...AS A DRY SLOT BETWEEN THE NOW FADING LOW
OVER SOUTHERN ONTARIO AND THE COASTAL LOW SOUTH OF COASTAL NEW
ENGLAND. THERE WILL BE A LINGERING CHANCE OF LIGHT SNOW ALONG THE
CHAUTAUQUA RIDGE WITH WESTERLY WINDS PROVIDING SUFFICIENT LIFT OF
THE MARGINAL LOW LEVEL MOISTURE TO CREATE LIGHT PRECIP. CENTRAL AND
NORTHERN NY WILL HAVE CHANCE POPS FOR LIGHT SNOW AS WELL...AND THE
ENTIRE FORECAST AREA WILL EXPERIENCE LOW TEMPS IN THE LOWER TO MID
20S DURING SATURDAY NIGHT.
EXPECT CLEARING AND SUNNIER SKIES ON SUNDAY FOR WESTERN NY AND
FINGER LAKES...WITH STUBBORN CLOUDS CLINGING TO THE CHAUTAUQUA
RIDGE...AND CONTINUED CLOUDINESS AND SCATTERED LIGHT SNOW ACROSS THE
NORTH COUNTRY FROM THE NOW DEPARTING COASTAL LOW. AN INFLUX OF
COLDER AIR FROM THE WEST WILL HOLD HIGH TEMPS ON SUNDAY TO THE LOWER
TO MIDDLE 30S.
UPPER RIDGING AND SURFACE HIGH PRESSURE WILL BRING NEARLY CLEAR
SKIES FOR SUNDAY NIGHT THROUGH MUCH OF MONDAY...WITH LOWS SUNDAY
NIGHT IN THE LOWER TO MIDDLE 20S AND HIGHS ON MONDAY IN THE UPPER
30S TO LOWER 40S.
ANOTHER MID CONTINENTAL CUT OFF LOW AND ATTENDANT SURFACE LOW WILL
RECURVE TO THE NORTHEAST ACROSS THE MID MISSISSIPPI
VALLEY...SHUNTING A WARM FRONT NORTHWARD TO THE OHIO VALLEY. THIS
WILL BRING MORE CLOUDINESS TO THE REGION MONDAY NIGHT AND A CHANCE
OF LIGHT SNOW OR A RAIN/SNOW MIX TO THE WESTERN SOUTHERN TIER. 00Z
GFS IS MUCH FASTER THAN 00Z ECMWF WITH THIS PRECIP MONDAY NIGHT...
THE PREFERRED MODEL IS THE ECMWF SO WILL GO CLOSER TO EC AND SLOW
SPREAD OF PRECIP TO MAINLY THE AREA WEST OF THE GENESEE RIVER.
LOW MONDAY NIGHT WILL BE LIMITED TO THE UPPER 20S TO LOWER 30S FOR
MOST OF THE REGION WITH THE INFLUX OF CLOUD COVER...THE LOWER TO MID
20S EAST OF LAKE ONTARIO WHERE CLOUDS WILL ARRIVE LATER.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
THE EXTENDED PERIOD WILL START OFF WITH FAIR WEATHER ON MONDAY AS
THE AXIS OF STRONG SURFACE RIDGING DRIFTS EAST ACROSS NEW YORK
STATE. WITH 850 MB TEMPS LOOKING TO BE IN THE -7C TO -8C RANGE...
TEMPS SHOULD BE SEASONABLE TO SLIGHTLY ABOVE NORMAL...WITH HIGHS IN
THE 35-40 RANGE.
AFTER THAT...CONDITIONS WILL GO DOWNHILL FOR THE REST OF THE PERIOD
AS A DEEP CUTOFF LOW FORMS OVER THE CENTRAL MISSISSIPPI VALLEY...
THEN MIGRATES INTO THE GREAT LAKES REGION. MEANWHILE AT THE
SURFACE...A CORRESPONDING SURFACE LOW OVER ILLINOIS WILL SLOWLY LIFT
NORTHEAST INTO THE CENTRAL GREAT LAKES...WHILE A SECONDARY WAVE OF
LOW PRESSURE DEVELOPS OFF THE MID ATLANTIC COAST.
WHILE THE MEDIUM RANGE MODELS AGREE ON THIS GENERAL SCENARIO...THEY
DISAGREE CONSIDERABLY ON THE TIMING OF ALL OF THIS...WITH THE 12Z
GFS MUCH FASTER WITH THE NORTHEASTWARD TRANSLATION OF THE CUTOFF AND
ASSOCIATED SURFACE LOW COMPARED TO THE MUCH SLOWER 12Z ECMWF...WITH
THE 12Z GEM GLOBAL LYING IN BETWEEN THESE TWO SOLUTIONS. THIS SORT
OF TIMING DISAGREEMENT IS TYPICAL FOR THE MODELS WHEN ATTEMPTING TO
HANDLE THE EVOLUTION OF A LARGE CUTOFF LOW THIS FAR OUT...WHICH IN
GENERAL TEND TO MOVE MORE SLOWLY THAN THE GUIDANCE SUGGESTS. WITH
THIS IN MIND...WILL TEND TO LEAN A BIT MORE TOWARD THE SLOWER ECMWF
FOR THE LATTER PORTIONS OF THE EXTENDED...THOUGH AT THE SAME TIME
WILL ALSO NOT ENTIRELY DISREGARD THE OTHER SOLUTIONS EITHER.
REGARDLESS OF THIS UNCERTAINTY IN TIMING...ALL OF THIS SHOULD
ULTIMATELY BRING INCREASED CHANCES FOR PRECIPITATION TO OUR AREA FOR
THE TUESDAY THROUGH THURSDAY PERIOD...WITH AT LEAST SOME POTENTIAL
FOR SIGNIFICANT PRECIP AMOUNTS /I.E. THOSE OF ONE INCH OR HIGHER/ AT
SOME POINT GIVEN WHAT SHOULD BE AN INFLUX OF PLENTIFUL ATLANTIC
MOISTURE ON THE EAST SIDE OF THIS SYSTEM. ACCORDINGLY...WILL
INDICATE A FAIRLY PROLONGED PERIOD OF HIGHER CHANCE TO EVEN SOME LOW
LIKELY POPS BEGINNING ON TUESDAY. IN TERMS OF PTYPE...TEMPS LOOK TO
BE RATHER MARGINAL THROUGHOUT THE MIDDLE OF NEXT WEEK...SO FOR NOW
WILL JUST INDICATE A GENERAL RAIN/SNOW MIX...WITH THE EXACT PTYPES
AT ANY GIVEN TIME DEPENDENT UPON THE POINT IN THE DIURNAL CYCLE.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
CIGS WILL CONTINUE TO IMPROVE THROUGH 15Z AS THE LOW LEVEL FLOW
TURNS SOUTHEAST ALLOWING THE INFLUX OF DRIER AIR. VFR CONDITIONS
WILL THEN PREVAIL FOR THE REST OF THE DAY. AS THE WARM FRONT MOVES
INTO THE AREA LATER THIS AFTERNOON AND INTO THE EVENING HOURS THERE
WILL LIKELY BE AT LEAST A BRIEF PERIOD OF -SN THAT WILL CHANGE OVER
TO A WINTRY MIX AS WARM AIR ALOFT MAKES ITS WAY INTO THE AREA.
HOWEVER MODEL SOUNDINGS INDICATE THE PRESENCE OF DRY AIR IN THE
MID-LEVELS THAT MAY BE CONDUCIVE TO PRECIP MAINLY FALLING AS DZ/FZDZ
AFTER 00Z ACROSS WESTERN NEW YORK AS TEMPERATURES WILL HOVER RIGHT
AROUND OR JUST ABOVE FREEZING...HOWEVER CONFIDENCE IS MEDIUM TO LOW
REGARDING THIS SCENARIO AT THIS POINT IN TIME AND FOR NOW WILL LEAVE
IT OUT OF TAFS WITH THE EXCEPTION OF KJHW WHERE CONFIDENCE IS HIGHER.
OUTLOOK...
TONIGHT AND SATURDAY...MVFR WITH A CHANCE OF MIXED
PCPN...TRANSITIONING TO A CHANCE OF RAIN.
SUNDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
MONDAY...VFR.
TUESDAY...MVFR WITH A CHANCE OF RAIN/SNOW.
&&
.MARINE...
EASTERLY WINDS WILL PICK UP TODAY AHEAD OF AN APPROACHING AREA OF
LOW PRESSURE...BRINGING INCREASING WAVE ACTION ABOVE 4 FEET ON THE
WESTERN HALF OF LAKE ONTARIO. ALTHOUGH THE BULK OF THE HIGHER WAVES
ARE EXPECTED OVER THE MIDDLE AND NORTHERN PORTIONS OF THE LAKE...
SMALL CRAFT CONDITIONS WILL LIKELY DEVELOP FOR A PERIOD LATE THIS
MORNING THROUGH THIS EVENING...WEST OF IRONDEQUOIT.
A COLD FRONT WILL THEN PUSH ACROSS THE LAKES ON SATURDAY...HOWEVER
THE PRESSURE GRADIENT ACROSS THE REGION SHOULD REMAIN RELAXED
ENOUGH THAT SMALL CRAFT ADVISORY CONDITIONS ARE NOT ANTICIPATED
THROUGH THE WEEKEND AT THIS TIME.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR LOZ042-043.
&&
$$
SYNOPSIS...TMA
NEAR TERM...TMA
SHORT TERM...WCH
LONG TERM...JJR
AVIATION...TMA
MARINE...TMA
AREA FORECAST DISCUSSION
NWS BUFFALO NY
332 AM EST FRI FEB 22 2013
.SYNOPSIS...
LOW PRESSURE WILL APPROACH THE AREA FROM THE OHIO VALLEY THROUGH
TONIGHT...BRINGING THE CHANCE FOR A LIGHT WINTRY MIX OF
PRECIPITATION THIS AFTERNOON THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER LOW CROSSING THE NEBRASKA/IOWA BORDER EARLY THIS MORNING
WILL MOVE NORTHEAST INTO SOUTHERN WISCONSIN BY THIS EVENING...
REACHING THE UPPER PENINSULA OF MICHIGAN BY LATE TONIGHT. THE
ACCOMPANYING LOW LEVEL THETA-E RIDGE ON THE NOSE OF A 50 KNOT PLUS
SOUTHERLY LOW LEVEL JET CURRENTLY FOCUSING A BAND OF PRECIPITATION
ACROSS SOUTHERN LOWER MICHIGAN INTO CENTRAL OHIO. LATEST HRRR RUNS
SEEMS TO HAVE A DECENT HANDLE ON SPEED OF APPROACHING
PRECIPITATION WHICH SHOWS LITTLE DEVIATION FROM PREVIOUS FORECAST
TIMING...PLACING THE LEADING EDGE OF WEAKENING PRECIPITATION
SHIELD INTO SOUTHWEST NEW YORK AROUND NOON TIME. EVAPORATIONAL
COOLING AFFECTS WILL MORE THAN LIKELY RESULT IN PRECIPITATION TYPE
AS PREDOMINANTLY SNOW...ALTHOUGH PORTIONS OF THE SOUTHERN TIER
COULD POTENTIAL EXPERIENCE SUFFICIENT LOW LEVEL WARM AIR ADVECTION
FOR PRECIPITATION TO CHANGE TO SLEET/FREEZING RAIN BRIEFLY BEFORE
MID LEVEL DRY SLOT MOVES IN. THE OVERALL SYSTEM TAKING ON A SPLIT
PATTERN AS THE MAIN UPPER LEVEL SUPPORT LIFTS NORTH AND WEST OF
THE AREA INTO THE UPPER LAKES...WHILE THE PRIMARY PLUME OF DEEP
MOISTURE SLIDES OFF TO THE SOUTH AND EAST INTO THE MID ATLANTIC
STATES. THIS WILL LIKELY GREATLY LIMIT THE PRECIPITATION POTENTIAL
ACROSS WESTERN NEW YORK WITH ONLY LIGHT AMOUNTS EXPECTED...WITH
EVEN THE POTENTIAL FOR SOME AREAS NOT RECEIVING ANY MEASURABLE
PRECIPITATION AT ALL. AFTER THE DRY SLOT MOVES THROUGH THE AREA
TONIGHT...LINGERING LOW LEVEL WARM AIR ADVECTION COMBINED WITH
SATURATED LOW LEVELS MAY RESULT IN A PERIOD OF FREEZING DRIZZLE
ACROSS THE AREA BEFORE LOW LEVELS DRY OUT A BIT AND THE WARM AIR
ADVECTION DIMINISHES. EVEN AT THIS STAGE OF THE FORECAST TOO MANY
UNCERTAINTIES TO ISSUE HEADLINES...ALTHOUGH HEADLINES MAY
EVENTUALLY BE NEEDED FOR PORTIONS OF THE AREA AS THE EVENT UNFOLDS.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
ON SATURDAY...THE LOW OVER THE GREAT LAKES WILL MOVE INTO SOUTHERN
ONTARIO AND WEAKEN AS THE COASTAL LOW MOVING NORTHEAST NEAR THE
CAROLINA COAST GATHERS STRENGTH OFFSHORE. THIS WILL MAINTAIN A SPLIT
IN THE PRECIP FIELD WITH MOST PRECIP NORTH AND SOUTH OF THE FORECAST
AREA...BUT INCREASING POPS OVER CENTRAL AND NORTHERN NY SATURDAY
AFTERNOON AND EVENING ASSOCIATED WITH GREAT LAKES/ONTARIO LOW`S COLD
FRONT INTERCEPTING WRAP AROUND MOISTURE FROM THE GATHERING STORM
ALONG THE COAST.
THE PRECIP TYPE WILL BE A WINTRY MIX IN THE MORNING WITH A CHANCE OF
SNOW...FREEZING RAIN AND SLEET FOR THE SOUTHERN TIER AND EASTERN
LAKE ONTARIO COUNTIES...AND PLAIN RAIN FOR THE WARMER LOWER
ELEVATIONS ALONG THE LAKE PLAINS SOUTH OF LAKE ONTARIO AND CLOSER TO
LAKE ERIE. THE PRECIP SHOULD TRANSITION TO ALL RAIN BY THE AFTERNOON
AS TEMPS CLIMB TO THE MID 30S TO LOWER 40S.
MID LEVEL MOISTURE BECOMES SCARCE FROM WEST TO EAST THROUGH THE LATE
AFTERNOON AND EVENING...AS A DRY SLOT BETWEEN THE NOW FADING LOW
OVER SOUTHERN ONTARIO AND THE COASTAL LOW SOUTH OF COASTAL NEW
ENGLAND. THERE WILL BE A LINGERING CHANCE OF LIGHT SNOW ALONG THE
CHAUTAUQUA RIDGE WITH WESTERLY WINDS PROVIDING SUFFICIENT LIFT OF
THE MARGINAL LOW LEVEL MOISTURE TO CREATE LIGHT PRECIP. CENTRAL AND
NORTHERN NY WILL HAVE CHANCE POPS FOR LIGHT SNOW AS WELL...AND THE
ENTIRE FORECAST AREA WILL EXPERIENCE LOW TEMPS IN THE LOWER TO MID
20S DURING SATURDAY NIGHT.
EXPECT CLEARING AND SUNNIER SKIES ON SUNDAY FOR WESTERN NY AND
FINGER LAKES...WITH STUBBORN CLOUDS CLINGING TO THE CHAUTAUQUA
RIDGE...AND CONTINUED CLOUDINESS AND SCATTERED LIGHT SNOW ACROSS THE
NORTH COUNTRY FROM THE NOW DEPARTING COASTAL LOW. AN INFLUX OF
COLDER AIR FROM THE WEST WILL HOLD HIGH TEMPS ON SUNDAY TO THE LOWER
TO MIDDLE 30S.
UPPER RIDGING AND SURFACE HIGH PRESSURE WILL BRING NEARLY CLEAR
SKIES FOR SUNDAY NIGHT THROUGH MUCH OF MONDAY...WITH LOWS SUNDAY
NIGHT IN THE LOWER TO MIDDLE 20S AND HIGHS ON MONDAY IN THE UPPER
30S TO LOWER 40S.
ANOTHER MID CONTINENTAL CUT OFF LOW AND ATTENDANT SURFACE LOW WILL
RECURVE TO THE NORTHEAST ACROSS THE MID MISSISSIPPI
VALLEY...SHUNTING A WARM FRONT NORTHWARD TO THE OHIO VALLEY. THIS
WILL BRING MORE CLOUDINESS TO THE REGION MONDAY NIGHT AND A CHANCE
OF LIGHT SNOW OR A RAIN/SNOW MIX TO THE WESTERN SOUTHERN TIER. 00Z
GFS IS MUCH FASTER THAN 00Z ECMWF WITH THIS PRECIP MONDAY NIGHT...
THE PREFERRED MODEL IS THE ECMWF SO WILL GO CLOSER TO EC AND SLOW
SPREAD OF PRECIP TO MAINLY THE AREA WEST OF THE GENESEE RIVER.
LOW MONDAY NIGHT WILL BE LIMITED TO THE UPPER 20S TO LOWER 30S FOR
MOST OF THE REGION WITH THE INFLUX OF CLOUD COVER...THE LOWER TO MID
20S EAST OF LAKE ONTARIO WHERE CLOUDS WILL ARRIVE LATER.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
THE EXTENDED PERIOD WILL START OFF WITH FAIR WEATHER ON MONDAY AS
THE AXIS OF STRONG SURFACE RIDGING DRIFTS EAST ACROSS NEW YORK
STATE. WITH 850 MB TEMPS LOOKING TO BE IN THE -7C TO -8C RANGE...
TEMPS SHOULD BE SEASONABLE TO SLIGHTLY ABOVE NORMAL...WITH HIGHS IN
THE 35-40 RANGE.
AFTER THAT...CONDITIONS WILL GO DOWNHILL FOR THE REST OF THE PERIOD
AS A DEEP CUTOFF LOW FORMS OVER THE CENTRAL MISSISSIPPI VALLEY...
THEN MIGRATES INTO THE GREAT LAKES REGION. MEANWHILE AT THE
SURFACE...A CORRESPONDING SURFACE LOW OVER ILLINOIS WILL SLOWLY LIFT
NORTHEAST INTO THE CENTRAL GREAT LAKES...WHILE A SECONDARY WAVE OF
LOW PRESSURE DEVELOPS OFF THE MID ATLANTIC COAST.
WHILE THE MEDIUM RANGE MODELS AGREE ON THIS GENERAL SCENARIO...THEY
DISAGREE CONSIDERABLY ON THE TIMING OF ALL OF THIS...WITH THE 12Z
GFS MUCH FASTER WITH THE NORTHEASTWARD TRANSLATION OF THE CUTOFF AND
ASSOCIATED SURFACE LOW COMPARED TO THE MUCH SLOWER 12Z ECMWF...WITH
THE 12Z GEM GLOBAL LYING IN BETWEEN THESE TWO SOLUTIONS. THIS SORT
OF TIMING DISAGREEMENT IS TYPICAL FOR THE MODELS WHEN ATTEMPTING TO
HANDLE THE EVOLUTION OF A LARGE CUTOFF LOW THIS FAR OUT...WHICH IN
GENERAL TEND TO MOVE MORE SLOWLY THAN THE GUIDANCE SUGGESTS. WITH
THIS IN MIND...WILL TEND TO LEAN A BIT MORE TOWARD THE SLOWER ECMWF
FOR THE LATTER PORTIONS OF THE EXTENDED...THOUGH AT THE SAME TIME
WILL ALSO NOT ENTIRELY DISREGARD THE OTHER SOLUTIONS EITHER.
REGARDLESS OF THIS UNCERTAINTY IN TIMING...ALL OF THIS SHOULD
ULTIMATELY BRING INCREASED CHANCES FOR PRECIPITATION TO OUR AREA FOR
THE TUESDAY THROUGH THURSDAY PERIOD...WITH AT LEAST SOME POTENTIAL
FOR SIGNIFICANT PRECIP AMOUNTS /I.E. THOSE OF ONE INCH OR HIGHER/ AT
SOME POINT GIVEN WHAT SHOULD BE AN INFLUX OF PLENTIFUL ATLANTIC
MOISTURE ON THE EAST SIDE OF THIS SYSTEM. ACCORDINGLY...WILL
INDICATE A FAIRLY PROLONGED PERIOD OF HIGHER CHANCE TO EVEN SOME LOW
LIKELY POPS BEGINNING ON TUESDAY. IN TERMS OF PTYPE...TEMPS LOOK TO
BE RATHER MARGINAL THROUGHOUT THE MIDDLE OF NEXT WEEK...SO FOR NOW
WILL JUST INDICATE A GENERAL RAIN/SNOW MIX...WITH THE EXACT PTYPES
AT ANY GIVEN TIME DEPENDENT UPON THE POINT IN THE DIURNAL CYCLE.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE MOVING ACROSS THE REGION TONIGHT WILL KEEP CONDITIONS
DRY THROUGH THE OVERNIGHT PERIOD. LIGHT NORTHERLY FLOW OFF OF LAKE
ONTARIO WILL LIKELY KEEP MVFR CIGS...WITH LOCALIZED IFR CONDITIONS
ACROSS HIGHER TERRAIN IN THE SOUTHERN TIER AND NORTH
COUNTRY...LOCKED IN ACROSS THE AREA AT LEAST THROUGH 08-10Z UNTIL
INCREASING EAST-SOUTHEAST FLOW HELPS CLEAR OUT LOWER CLOUD
COVER...ALLOWING CONDITIONS TO IMPROVE TO VFR.
HIGH CLOUDS STREAMING NORTH AHEAD OF AN APPROACHING WARM FRONT WILL
MOVE INTO THE REGION LATER TONIGHT...HOWEVER VFR CONDITIONS SHOULD
PREVAIL AT LEAST THROUGH THE MORNING HOURS. BREEZY SOUTHEASTERLY
FLOW WILL DEVELOP AT KJHW DURING THE AFTERNOON AS STRONGER WINDS
ALOFT MIX DOWN TO THE SURFACE...BUT OTHERWISE OTHER TERMINALS SHOULD
STAY SOUTHEASTERLY AROUND 10KTS.
AS THE WARM FRONT MOVES INTO THE AREA LATER TOMORROW AFTERNOON AND
INTO THE EVENING HOURS THERE WILL LIKELY BE AT LEAST A BRIEF PERIOD
OF -SN THAT WILL CHANGE OVER TO A WINTRY MIX AS WARM AIR ALOFT MAKES
ITS WAY INTO THE AREA. HOWEVER MODEL SOUNDINGS INDICATE THE PRESENCE
OF DRY AIR IN THE MID-LEVELS THAT MAY BE CONDUCIVE TO PRECIP MAINLY
FALLING AS DZ/FZDZ AFTER 21Z ACROSS WESTERN NEW YORK AS TEMPERATURES
WILL HOVER RIGHT AROUND OR JUST ABOVE FREEZING...HOWEVER CONFIDENCE IS
MEDIUM TO LOW REGARDING THIS SCENARIO AT THIS POINT IN TIME AND FOR
NOW WILL LEAVE IT OUT OF TAFS WITH THE EXCEPTION OF KJHW WHERE
CONFIDENCE IS HIGHER.
OUTLOOK...
FRIDAY NIGHT AND SATURDAY...MVFR WITH A CHANCE OF MIXED
PCPN...TRANSITIONING TO A CHANCE OF RAIN.
SUNDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
MONDAY...VFR.
TUESDAY...MVFR WITH A CHANCE OF RAIN/SNOW.
WEDNESDAY...MVFR WITH A CHANCE OF SNOW SHOWERS.
&&
.MARINE...
EASTERLY WINDS WILL PICK UP TODAY AHEAD OF AN APPROACHING AREA OF
LOW PRESSURE...BRINGING INCREASING WAVE ACTION ABOVE 4 FEET ON THE
WESTERN HALF OF LAKE ONTARIO. ALTHOUGH THE BULK OF THE HIGHER WAVES
ARE EXPECTED OVER THE MIDDLE AND NORTHERN PORTIONS OF THE LAKE...
SMALL CRAFT CONDITIONS WILL LIKELY DEVELOP FOR A PERIOD LATE THIS
MORNING THROUGH THIS EVENING...WEST OF IRONDEQUOIT.
A COLD FRONT WILL THEN PUSH ACROSS THE LAKES ON SATURDAY...HOWEVER
THE PRESSURE GRADIENT ACROSS THE REGION SHOULD REMAIN RELAXED
ENOUGH THAT SMALL CRAFT ADVISORY CONDITIONS ARE NOT ANTICIPATED
THROUGH THE WEEKEND AT THIS TIME.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR LOZ042-043.
&&
$$
SYNOPSIS...TMA
NEAR TERM...TMA
SHORT TERM...WCH
LONG TERM...JJR
AVIATION...WOOD
MARINE...TMA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
642 AM CST FRI FEB 22 2013
.DISCUSSION...
NO SIGNIFICANT CHANGES WERE REQUIRED WITH THIS FORECAST UPDATE AS
THE ONGOING FORECAST FOR TODAY IS WELL SUPPORTED BY THE FULL 06
UTC GUIDANCE SUITE AND THE LATEST RAP RUNS. DRY LOW LEVEL AIR
ACROSS THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY WILL
KEEP THESE LOCATIONS SNOW FREE THE REMAINDER OF THE DAY. VERY
LIGHT SNOW/FLURRIES WILL CONTINUE ALONG AND WEST OF THE HIGHWAY 83
CORRIDOR THIS MORNING...AS WEAK ISENTROPIC LIFT SLOWLY FADES BY
EARLY AFTERNOON.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS WESTERN AND CENTRAL NORTH DAKOTA
FOR THE 12 UTC TAF CYCLE WELL NORTHWEST OF A STRONG WINTER STORM
ACROSS THE UPPER MISSISSIPPI VALLEY. WHILE AREAS OF MVFR CONDITIONS
IN SCATTERED LIGHT SNOW SHOWERS ARE POSSIBLE THIS MORNING...IMPACTS
TO THE TERMINALS IS EXPECTED TO BE NONE TO MINIMAL. WHILE
UNCERTAINTY IS HIGH...THERE IS A POTENTIAL FOR FOG TONIGHT AT
KMOT...KBIS AND KJMS AFTER 10 UTC AS SKIES CLEAR WITH LIGHT
WINDS. GIVEN THE UNCERTAINTY...ONLY REDUCED VISIBILITIES TO 5-6 SM
AND WILL LET LATER SHIFTS EVALUATE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
131 AM CST FRI FEB 22 2013
.DISCUSSION...MAIN UPDATE EARLY THIS MORNING WAS PRECIPITATION
PLACEMENT AND TEMPERATURES.
NORTH TO SOUTH BAND OF LIGHT SNOW CONTINUES ACROSS
WESTERN/CENTRAL NORTH DAKOTA. WEAK UPPER LEVEL TROUGH FROM THE
MANITOBA ROCKIES SOUTH THROUGH CENTRAL MONTANA MOVING VERY SLOWLY
EAST AND MAY CONTRIBUTE TO ADDITIONAL WEAK FORCING FOR LIGHT SNOW
ACROSS MY WEST NOW THROUGH 15Z. ALSO...A FEW SNOW SHOWERS
ASSOCIATED WITH THE UPPER LOW TO OUR SOUTH HAVE MADE IT INTO FAR
SOUTHERN NORTH DAKOTA AROUND WISHEK. MADE ADJUSTMENTS TO POPS
BASED ON LATEST RADAR RETURNS AND THE RAP GUIDANCE.
ADJUSTED TEMPERATURES BASED ON LATEST OBS AND NEAR TERM MODEL
DATA. SURFACE DEWPOINT TEMPERATURES LOOK TO REMAIN IN THE MID TO
UPPER TEENS WEST SO INCREASED LOWS THERE. LOWERED TEMPERATURES
ACROSS MY NORTHEAST WHERE NEAR ZERO SFC TDS ARE LOCATED/ADVECTING
INTO.
&&
.AVIATION...
MODEL GUIDANCE INDICATES ABUNDANT LOW LEVEL MOISTURE AND
NUMERICAL GUIDANCE INDICATES AT LEAST PATCHY IF NOT WIDESPREAD
FOG OVER TAF SITES TONIGHT. EXCEPT FOR KISN AND KDIK WHERE
VISIBILITIES ARE ALREADY REDUCED IN LIGHT SNOW...WILL BRING IN
AREAS OF LOWER CEILINGS...BUT WILL DELAY THE TIMING FROM WHAT
NUMERICAL GUIDANCE INDICATES. THEN KEEP MAINLY MVFR CEILINGS
THROUGH FRIDAY MORNING...AND BREAKING OUT TO VFR BY FRIDAY
AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
AVIATION...TWH/NH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
108 AM EST FRI FEB 22 2013
.SYNOPSIS...
A WINTRY MIX OF SNOW AND SLEET...SHOULD TRANSITION TO FREEZING
RAIN AS TEMPERATURES REMAIN BELOW FREEZING AT THE SURFACE OVERNIGHT.
TEMPERATURES WILL RISE ABOVE FREEZING AND THE FREEZING RAIN WILL
TRANSITION TO RAIN LATE TONIGHT THROUGH FRIDAY MORNING. A COLD
FRONT WILL THEN PUSH ACROSS THE AREA FRIDAY NIGHT WITH SEASONABLE
TEMPERATURES EXPECTED FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE FORECAST HAS BEEN UPDATED TONIGHT WITH A FEW CHANGES.
FIRST...POPS WERE INCREASED AND SPED UP...AS PRECIPITATION HAS
ALREADY ENTERED ABOUT A THIRD OF THE CWA. TIMING WAS BASED HEAVILY
ON LATEST HRRR RUNS...WITH THE BACK EDGE OF THE PRECIPITATION ALSO
SPED UP A LITTLE BIT TOMORROW MORNING. GIVEN THE CERTAINTY OF
PRECIPITATION...100 PERCENT CHANCES WERE USED EVERYWHERE.
THE MORE COMPLICATED DECISIONS WERE RELATED TO PRECIPITATION TYPE.
IT IS APPARENT FROM THE RECENT OBSERVATIONS THAT THE WARM
ADVECTION ALOFT IS PERHAPS OCCURRING SLIGHTLY SLOWER THAN WAS
EARLIER FORECAST. ON THE OTHER HAND...THIS COULD ALSO BE THE
RESULT OF THE FASTER ONSET OF PRECIPITATION THAN WAS PREVIOUSLY
ANTICIPATED. BECAUSE OF THIS...HYDROMETEORS AT PRECIP ONSET ARE
NOT COMPLETING MELTING...LEADING TO A PLETHORA OF SLEET OBS OVER
THE ILN CWA...AND A POCKET OF MODERATE SNOW NOW MOVING INTO THE
WHITEWATER VALLEY AREA.
FREEZING RAIN IS STILL EXPECTED TO BE THE PRIMARY PRECIPITATION
TYPE OVERNIGHT...BUT THE GRIDS NOW REFLECT A GREATER MIXING IN THE
FIRST FEW HOURS OF THE FORECAST. SNOW/SLEET ACCUMULATIONS OF UP TO
A HALF INCH WERE ADDED INTO THE INDIANA COUNTIES AND WESTERN MIAMI
VALLEY (MAINLY EXPECTED IN THE NEXT FEW HOURS)...WITH THE ORIGINAL
FORECAST OF UP TO AN INCH OF SNOW IN THE FAR NORTH STILL ON TRACK.
THE WINTER WEATHER ADVISORY ISSUED BY THE DAY SHIFT COVERS THIS
MIX OF PRECIPITATION QUITE WELL...SO WHILE UPDATES WERE MADE TO
ADD SOME OF THE NEW DETAIL...THE OVERALL PLAN AND LAYOUT FOR THE
HEADLINE PRODUCT HAS NOT CHANGED.
PREVIOUS DISCUSSION >
FOCUS IS ON POTENTIAL FOR ICE EVENT TONIGHT/FRIDAY MORNING IN THE
OHIO VALLEY. UPPER LEVEL AND SFC LOW OVER CENTRAL PLAINS TO EJECT
NE INTO THE MID MS VLY BY 12Z FRIDAY. FAVORABLE ISENTROPIC LIFT
DEVELOPS AHD OF THIS SYSTEM ACRS ILN/S FA TONIGHT. SOUTHERLY 8H
JET OF 60KTS WEAKENS TO 50-55KTS AS IT MOVES INTO THE OHIO VALLEY
BY MORNING. THIS JET WORKS TO PROVIDE GOOD FORCING AND WAA. THE
BEST LIFT DEVELOPS BETWEEN 06Z AND 12Z. WILL CONTINUE RAMPING POPS
UP TO CATEGORICAL LATE THIS EVENING INTO EARLY FRIDAY. QUESTION
REVOLVES AROUND QPF/THERMAL PROFILES AND ULTIMATELY THE AMOUNT OF
ICING. NAM IS THE MORE ENERGETIC WITH FORCING AND THEREFORE HAS
HIGHER QPF. 12Z RUN SOLNS ARE CLOSER AND THEREFORE HAVE GONE WITH
A BLENDED SOLN. UNDER STRONG WAA...TEMPS ALOFT WARM SUFFICIENTLY
FOR LIQUID WHILE SFC TEMPS REMAIN BELOW FREEZING WITH A LOW LEVEL
EASTERLY FLOW.
EXPECT NON-DIURNAL TEMPERATURES WITH READINGS RISING ABOVE
FREEZING ACRS THE FAR SOUTH TOWARD SUNRISE. BASED ON A PROLONGED
PERIOD OF BELOW FREEZING TEMPERATURES EXPECT 1 TO 2 TENTHS OF AN
INCH OF ICE ACCUMULATION WITH THE HIGHEST AMOUNTS ACRS EAST
CENTRAL INDIANA/WHITEWATER VALLEY AND THE MIAMI VALLEY. WILL
CONTINUE WINTER WEATHER ADVISORIES ACRS THE ENTIRE FA FOR THIS
ICE IMPACT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
UPPER LEVEL/SFC LOW PRESSURE TO MIGRATE SLOWLY NE FROM THE UPR MS
VLY INTO THE WESTERN GREAT LAKES FRIDAY. NUMERICAL MODEL SOLNS
CONSISTENT WITH DEEP MSTR AND FORCING ASSOCIATED WITH STRONG LLJ
SHIFTING NE OF ILNS FA FRIDAY MORNING. AT THE SAME TIME UNDER THE
INFLUENCE OF WAA...SFC TEMPERATURES WARM ABOVE FREEZING BY MIDDAY
FROM SOUTH TO NORTH. WILL DIMINISH POPS A LTL QUICKER TO REFLECT
THIS FASTER TIMING AS THE FAVORABLE FORCING EXITS THE REGION.
EXPECT HIGH TEMPS TO BE A LTL ABOVE NORMAL...RANGING FROM THE
UPPER 30S NW TO THE LOWER 50S FAR SOUTH.
SFC LOW TO MIGRATE THRU THE GREAT LAKES WITH A TRAILING COLD
FRONT FROM THE LOW CROSSING THE FORECAST AREA FRIDAY NIGHT. THIS
WILL BRING A RETURN TO COLDER...MORE SEASONABLE TEMPERATURES. DUE
TO A LACK OF SIGNIFICANT FORCING AND MSTR HAVE ONLY CONTINUED
SLIGHT CHC POPS ACRS THE FAR NORTH. FRIDAY NIGHTS LOWS WILL RANGE
FROM THE UPPER 20S NORTHWEST TO THE MID 30S SE.
UPPER LOW TO CONTINUE TO WORK ACRS THE GREAT LAKES SAT/SAT NIGHT.
BETTER MSTR LOOKS TO STAY NORTH OF ILNS/ FA AND IT APPEARS AT
THIS TIME THAT THE FLOW TRAJECTORIES AROUND THE LOW WILL NOT BE
FAVORABLE TO BRING ANY SNOW SHOWERS INTO OUR AREA. THEREFORE HAVE
MAINTAINED A DRY FCST. EXPECT SATURDAYS HIGHS TO BE A LTL BELOW
NORMAL...RANGING FROM THE MID 30S NW TO THE MID 40S SE. LOWS SAT
NIGHT ARE EXPECTED TO RANGE FROM THE LOWER 20S NW TO THE MID 20S SE.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MODELS SHOW HIGH PRESSURE BUILDING IN ON SUNDAY SO KEPT THE FORECAST
DRY. NEXT SYSTEM DUE TO ARRIVE LATE MONDAY IS SLOWER ON LATEST MODEL
RUNS...SO HELD BACK ONSET AND ENDING OF SHOWERS BY A FEW HOURS.
COLDER TEMPERATURES EARLY MONDAY NIGHT MAY ALLOW SNOW TO MIX IN FOR
A TIME. MAIN BAND OF SHOWERS SHOULD EXIT EAST TUESDAY AFTERNOON.
A COLDER PATTERN WITH A LINGERING LOW OVER THE GREAT LAKES WILL SET
UP TUESDAY NIGHT THROUGH THURSDAY. THIS WILL RESULT IN A FEW ROUNDS
OF SNOW SHOWERS...WITH RAIN POSSIBLY MIXING IN AT SOUTHERN
LOCATIONS.
COOL READINGS AROUND 40 ON SUNDAY WILL BE BOOSTED CLOSE TO 50 ON
MONDAY DUE TO WARM ADVECTION AHEAD OF THE LOW. BELOW NORMAL HIGHS IN
THE 30S ARE EXPECTED BY THURSDAY IN A NORTHWESTERLY LOW LEVEL FLOW.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
FREEZING RAIN WILL START OUT THE TAF PERIOD AT KCVG AND KLUK.
FURTHER TO THE NE AT KILN SOME ICE PELLETS MAY STILL MIX IN WITH
THE FREEZING RAIN AT THE TAF ONSET HOWEVER AS THE OVERNIGHT HOURS
PROGRESS THE PRECIPITATION TYPE WILL GENERALLY BE FREEZING RAIN.
AT KDAY A MIXTURE OF SNOW AND ICE PELLETS WILL START OUT THE TAF
PERIOD AND THEN ALSO GRADUALLY TRANSITION OVER TO FREEZING RAIN.
KCMH AND KLCK TAF SITES WILL START OUT DRY HOWEVER SNOW AND ICE
PELLETS WILL QUICKLY MOVE INTO THOSE LOCATIONS. KCMH AND KLCK WILL
ALSO GRADUALLY TRANSITION OVER TO FREEZING RAIN DURING THE
OVERNIGHT HOURS.
TEMPERATURES WILL GRADUALLY WARM ACROSS THE TAF SITES OVERNIGHT
AND INTO FRIDAY WITH TAF SITES SURFACE TEMPERATURES GOING ABOVE
FREEZING BETWEEN AROUND 10Z AT KCVG AND KLUK TO 14Z AT KCMH AND
KLCK. RAIN WILL TAPER OFF DURING THE MORNING HOURS ACROSS THE TAF
SITES LEAVING MAINLY DRY CONDITIONS BY THE LATE MORNING HOURS.
WINDS WILL GUST OFF AND ON FOR A FEW HOURS AT THE BEGINNING TO THE
TAF PERIOD. AFTER THIS TIME EXPECT WIND GUST ACTIVITY TO DECREASE
HOWEVER WINDS WILL STAY UP ACROSS THE TAF SITES. SOME ADDITIONAL
WIND GUSTS WILL BE POSSIBLE DURING THE AFTERNOON HOURS ON FRIDAY
AT KCVG. WINDS WILL BE OUT OF THE EAST TO START AND GRADUALLY
TRANSITION TO SOUTHERLY AND FINALLY TO WEST SOUTHWEST AS THE TAF
PERIOD PROGRESSES.
VFR CIGS WILL START OUT THE TAF PERIOD HOWEVER EXPECT CIGS TO
GRADUALLY BECOME MVFR TO IFR ACROSS THE TAF SITES. MOST OF THE TAF
SITES WILL STAY MVFR TO IFR THEN THROUGH THE TAF PERIOD HOWEVER
KCVG AND KLUK MAY BECOME VFR FOR A FEW HOURS DURING THE AFTERNOON
ON FRIDAY.
OUTLOOK...MVFR TO IFR CEILINGS MAY CONTINUE INTO FRIDAY
NIGHT...AND POSSIBLY THROUGH SATURDAY FOR THE NORTHERN TAF SITES.
MVFR CONDITIONS ARE POSSIBLE AGAIN ON MONDAY AND TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR OHZ026-034-
035-042>046-051>056-060>065-070>074-080-082.
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
OHZ077>079-081-088.
KY...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
KYZ089>100.
IN...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR INZ050-058-
059-066.
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
INZ073>075-080.
&&
$$
SYNOPSIS...AR
NEAR TERM...HATZOS/AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...NOVAK
AREA FORECAST DISCUSSION
NWS MEDFORD OR
830 PM PST THU FEB 21 2013
.DISCUSSION...WE HAVE LOWERED CHANCES FOR PRECIPITATION ACROSS THE
NORTHERN CALIFORNIA AND EXTREME SOUTHWESTERN OREGON FOR TONIGHT
GIVEN THE LATEST OBSERVATIONS AND RAP GUIDANCE FOR TONIGHT. THE
WARM FRONTAL PRECIPITATION WILL WANE OVERNIGHT...FOCUSING
PRIMARILY OVER THE CASCADES. A BRIEF BREAK IN PRECIPITATION WILL
OCCUR FRIDAY MORNING AHEAD OF THE STRONG COLD FRONT.
TODAY`S EFFORTS HAVE BEEN FOCUSED ON THE STRONG STORM DUE TO
ARRIVE FRIDAY EVENING...LETTING US KNOW THAT WINTER IS STILL ALIVE
AND WELL IN SOUTHERN OREGON. A WINTER STORM WARNING AND A COUPLE
WINTER WEATHER ADVISORIES HAVE BEEN ISSUED AT WSWMFR TO HIGHLIGHT
THE SNOWFALL EXPECTED. ADDITIONALLY...HIGH SURF AND STRONG WINDS
WILL IMPACT THE COAST...AND A SPECIAL WEATHER STATEMENT AT SPSMFR
BRINGS ATTENTION TO THIS. ESRL REFORECAST ANALOGS CONFIRM OUR
THOUGHTS THAT THIS WILL BE A SIGNIFICANT WINTER STORM...SUGGESTING
THIS WILL RANK IN THE TOP THIRD IN TERMS OF 24-HR PRECIPITATION FOR
MOST OF SOUTHERN OREGON ALONG AND WEST OF THE CASCADES. STRONG WEST
WINDS WILL ACCOMPANY THIS STORM...THUS FOCUSING THE HEAVIEST
PRECIPITATION OVER WEST AND NORTHWEST FACING SLOPES OF THE CASCADES.
TRAVEL IN AND AROUND THE CASCADES WILL BE SEVERELY IMPACTED FROM
FRIDAY NIGHT INTO SATURDAY.
FOR LOWER ELEVATIONS OF THE WEST SIDE...AROUND 2000 FEET OR A BIT
LOWER...MODELS STILL POINT TOWARD THE POSSIBILITY OF SNOWFALL LATE
FRIDAY NIGHT OR SATURDAY MORNING. 850MB TEMPERATURES BOTTOM OUT NEAR
-6C...AND A SECONDARY PULSE OF UPWARD MOTION AND ASSOCIATED SHOWERS
IN THE NAM ARE GOOD INDICATORS OF THIS POSSIBILITY.
PLEASE SEE THE DISCUSSION BELOW FOR MORE DETAILS REGARDING THE
EVOLUTION OF THE APPROACHING STORM...AND THE EXPECTED CONTINUATION
OF ACTIVE WEATHER THROUGH EARLY NEXT WEEK.
&&
.AVIATION...FROM THE CASCADES WEST...AREAS OF MVFR CIGS WITH HIGHER TERRAIN
OCCASIONALLY OBSCURED WILL PERSIST INTO FRIDAY MORNING. CONDITIONS
WILL BRIEFLY IMPROVE TO LOCAL MVFR CIGS LATE FRIDAY MORNING...THEN
WIDESPREAD MVFR CIGS WITH AREAS OF MVFR VSBYS WITH HIGHER TERRAIN
OBSCURED WILL SPREAD INLAND FROM THE COAST FRIDAY AFTERNOON.
STRONG SOUTH WINDS WILL AFFECT THE COAST FRIDAY. MODERATE TO
HEAVY RAIN AND STRONG WINDS WILL ACCOMPANY THE LOWER CIG/VSBYS.
FREEZING LEVELS WILL DROP SHARPLY FRIDAY AFTERNOON AS THE COLD
FRONT MOVES INLAND...AND MODERATE TO HEAVY SNOW WILL AFFECT THE
HIGHER TERRAIN.
EAST OF THE CASCADES...MOSTLY VFR CONDITIONS WILL PREVAIL INTO
FRIDAY AFTERNOON. GUSTY WINDS WILL DEVELOP FRIDAY AFTERNOON...THEN
AREAS OF MVFR CIGS/VSBYS IN RAIN AND SNOW WILL DEVELOP LATE FRIDAY
AFTERNOON NEAR THE CASCADES.
&&
.PREV DISCUSSION... /ISSUED 414 PM PST THU FEB 21 2013/
DISCUSSION...A STRONG FRONT IS EXPECTED TO BRING SIGNIFICANT
SNOWFALL TO THE NORTHERN CASCADES LATE FRIDAY INTO EARLY SATURDAY.
WEST SIDE VALLEYS COULD ALSO SEE SEVERAL INCHES OF SNOW DOWN TO
2000 FEET BY SATURDAY MORNING.
BUT BEFORE WE GET TO THAT SYSTEM, WE ARE WATCHING A WEAKER FRONT
MOVE ACROSS THE AREA THIS AFTERNOON. THIS SYSTEM IS BEHAVING AS THE
MODELS INDICATED AND MANY OF THE WEST SIDE OBSERVATION SITES HAVE
REPORTED LIGHT RAIN ALREADY. THIS SYSTEM WILL MAKE ITS WAY INLAND TO
THE CASCADES BEFORE FALLING APART OVER THAT HIGHER TERRAIN LATER
TONIGHT.
THEN THE ATTENTION SHIFTS TO FRIDAY AFTERNOON. THE COLD FRONT IS
STILL ON TRACK WITH VERY FEW CHANGES FROM THE EARLIER MODEL RUNS.
THE BRUNT OF THE ENERGY WITH A 100+ KT JET IS STILL FOCUSED OVER
NORTHERN OREGON. BUT THERE WILL STILL BE PLENTY OF ACTIVITY OVER
THE SOUTHERN CASCADES. RIGHT NOW, IT LOOKS AS IF THE HEAVIEST SNOW
ACCUMULATION WILL ALIGN FROM THE LAKE OF THE WOODS AREA NORTHWARD.
THE FRONT ITSELF WILL BE RESPONSIBLE FOR PRODUCING THE MAJORITY OF
THE PRECIPITATION AND THE HEAVIEST ACCUMULATION WILL LIKELY BE
LATE FRIDAY AFTERNOON INTO FRIDAY EVENING. THEN THE MODELS SHOW A
SLIGHT BREAK AROUND MIDNIGHT BEFORE MORE SHOWERS FILL IN OVER THE
SAME AREA SATURDAY MORNING. THERE IS A FAIR AMOUNT OF UNCERTAINTY
WITH ACCUMULATIONS IN THESE SHOWERS THROUGH THE DAY SATURDAY. BUT
AMOUNTS AND INTENSITY SHOULD DECREASE SIGNIFICANTLY AFTER
DAYBREAK, SO HAVE OPTED TO END THE WARNING AT 4AM.
WE ALSO ELECTED TO HOIST A WINTER WEATHER ADVISORY WSWMFR FOR
AREAS ABOVE 2000 FEET WEST OF THE CASCADES. ACCUMULATIONS WILL
DEFINITELY BE HEAVIEST ON WEST AND NORTHWEST FACING SLOPES WITH
40KTS AT 850MB LEADING TO UPSLOPE ENHANCEMENT. THE TIMING OF THE
COLD AIR LOOKS TO MAKE IT IN BEHIND THE FRONT WHILE ENOUGH
MOISTURE LINGERS TO PRODUCE 1 TO 3 INCHES OF ACCUMULATION. WITH
THE MAJORITY OF THE PRECIPITATION FALLING DURING THE OVERNIGHT
HOURS THIS WILL MAKE FOR THE BEST CHANCE FOR ACCUMULATION ON
ROADWAYS AS TEMPERATURES BOTTOM OUT. MODELS DID SHOW A SLIGHT
TENDENCY TO SHUNTING THE COLD AIR TO THE NORTH AND EAST OF OUR
AREA, SO WE WILL BE KEEPING AN EYE ON THIS. THE NEXT COMPONENT OF
THIS SYSTEM WILL BE GUSTY SW WINDS. WINDS SHOULD MAKE ADVISORY
CRITERIA OVER THE HIGHER TERRAIN EAST OF THE CASCADES. AND EVEN
FOR THE WEST SIDE, WINDS COULD CAUSE ENOUGH BLOWING SNOW TO MAKE
TRAVEL THAT MUCH MORE CHALLENGING.
FOR THE REST OF THE WEEKEND...SHOWERS WILL CONTINUE IN THE WAKE OF
THE STRONG FRONT ON SATURDAY. ACCUMULATIONS SHOULD BE LIGHT DURING
THE DAY AND THEN TAPER OFF COMPLETELY BEFORE SUNDAY MORNING. THE
BIGGEST STORY FOR SATURDAY WILL BE THE HIGH SURF AT THE COAST. SEE
THE SPSMFR FOR MORE DETAILS ON THIS. SUNDAY WILL BRING A
SHORTWAVE RIDGE TO DRY OUT THE AREA AND ALLOW SNOW LEVELS TO
REBOUND TO NEAR 4000 FT.
..EXTENDED TERM...MONDAY THOUGH THURSDAY NIGHT...
THE LONG TERM MODEL SOLUTIONS ARE SIMILAR IN TIMING...BUT HAVE
CONSIDERABLE DIFFERENCES IN THE OVERALL STRENGTH OF THE VARIOUS
WEATHER MAKING FEATURES THAT ARE EXPECTED TO PASS THROUGH THE AREA.
THIS OF COURSE RESULTS IN REDUCED CONFIDENCE FOR MOST OF THE
FORECAST DETAILS. HOWEVER...THERE REMAINS DECENT CONFIDENCE IN THE
OVERALL PATTERN.
THE FIRST SYSTEM TO ENTER THE REGION WILL RIDE THE NORTHWEST FLOW
ALOFT INTO THE AREA MONDAY. THE TROUGH...MORE PRONOUNCED AND SHARPER
IN THE ECMWF SOLUTION THAN IN THE GFS...SHOULD RESULT IN INCREASED
CHANCES OF PRECIPITATION...ESPECIALLY NORTH OF THE OREGON/CALIFORNIA
STATE LINE. SNOW LEVELS LOOK TO STAY ABOVE 3000 FEET DURING THE
EVENT...AND PRECIPITATION AMOUNTS APPEAR TO BE MUCH LIGHTER THAN IN
THE SHORT TERM SYSTEMS. HOWEVER...DESPITE THE TROUGH EXITING THE
AREA MONDAY NIGHT AND WEAK RIDGING BUILDING INTO THE AREA...THERE
REMAINS THE CHANCE OF LINGERING SHOWERS THROUGH TUESDAY.
THE NEXT SYSTEM...DUE TUESDAY NIGHT OR WEDNESDAY...APPEARS EVEN
WEAKER THAN THE PREVIOUS...AND IS FORECAST TO PASS FURTHER TO THE
NORTH. WITH SNOW LEVELS OF 5000 FEET OR ABOVE...MOST PRECIPITATION
IN THE AREA WILL BE LIGHT RAIN. SHOWERS AND ONSHORE FLOW ARE
EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE TERM.
WITH HIGH PRESSURE GAINING MORE AND MORE INFLUENCE AS THE WEEK
PROGRESSES...TEMPERATURES WILL EXPERIENCE A GRADUAL WARMING TREND
THROUGH THE TERM...FROM SLIGHTLY BELOW NORMAL AT THE BEGINNING OF
THE WEEK TO NEAR NORMAL OR SLIGHTLY ABOVE BY THURSDAY.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY FROM 1 PM FRIDAY TO 4 AM PST SATURDAY FOR
ORZ030-031.
WINTER WEATHER ADVISORY FROM 10 PM FRIDAY TO 10 AM PST SATURDAY
FOR ORZ023-024-026.
WINTER STORM WARNING FROM 4 PM FRIDAY TO 4 AM PST SATURDAY FOR
ORZ027-028.
WINTER WEATHER ADVISORY FROM 8 PM FRIDAY TO 10 AM PST SATURDAY
FOR ORZ025.
CA...WIND ADVISORY FROM 1 PM FRIDAY TO 4 AM PST SATURDAY FOR CAZ085.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 4 AM TO 4 PM PST FRIDAY FOR
PZZ356-376.
HAZARDOUS SEAS WARNING FROM 7 AM FRIDAY TO 10 PM PST SATURDAY
FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 7 AM PST FRIDAY
FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS FROM 4 AM TO 10 AM PST FRIDAY FOR
PZZ350-370.
GALE WARNING FROM 10 AM TO 4 PM PST FRIDAY FOR PZZ350-370.
$$
NSK/BPN/JRS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1201 AM CST FRI FEB 22 2013
.UPDATE...FOR 06Z TAFS...
&&
.AVIATION...
ONLY A FEW WEAK SHOWERS STILL SHOWING UP ON THE RADAR. BNA AND CKV
SHOULD BE DRY FOR THE REMAINDER OF THE TAF PERIOD WITH A FEW LIGHT SHOWERS
POSSIBLE AT CSV THROUGH 07Z. LIGHT FOG MAY REDUCE VISIBILITIES TO
AROUND 4 MILES AT SOME SITES IN THE EARLY MORNING HOURS. CIGS ARE
CONTINUING TO DROP INTO IFR RANGE AS THE PRECIP MOVES EAST...BUT
CONDITIONS ARE EXPECTED TO IMPROVE CLOSER TO DAWN ON FRIDAY WITH
INCREASING CIGS AND VISIBILITY. HOWEVER OVERCAST HIGH CLOUDS ARE
EXPECTED TO REMAIN IN PLACE THROUGHOUT THE DAY.
&&
.PREV DISCUSSION... /ISSUED 816 PM CST THU FEB 21 2013/
UPDATE...
LATEST RADAR IMAGERY SHOWS LARGE AREA OF LIGHT TO MODERATE RAIN
ACROSS THE MID STATE...BUT BACK EDGE CAN BE SEEN NOW EAST OF THE
MISSISSIPPI RIVER. HRRR TIMING INDICATES MOST OF THE RAIN WILL
LIKELY END WEST OF I-65 AROUND MIDNIGHT...WITH SOME RAIN
CONTINUING THROUGH THE NIGHT TO THE EAST. HAVE ADJUSTED POPS
DOWNWARD IN THE 06-12Z TIMEFRAME WITH CHANCE POPS IN THE WEST TO
CATEGORICAL IN THE EAST. WILL ALSO ADD MENTION OF ISOLATED THUNDER
TO THE SOUTHWEST HALF OF THE CWA THIS EVENING AS A FEW LIGHTNING
STRIKES HAVE BEEN NOTED FROM TIME TO TIME.
TEMPERATURES CURRENTLY RANGE FROM THE MID 30S ALONG THE KY BORDER
TO THE MID 40S ALONG THE AL BORDER. THESE VALUES WILL BE THE LOWS
FOR TONIGHT AS WAA CONTINUES TO INCREASE THROUGH THE NIGHT AND
TEMPERATURES WARM WELL INTO THE 40S AREAWIDE BY SUNRISE AND
POSSIBLY 50S IN OUR SOUTHERN ZONES. MADE MINOR ADJUSTMENTS TO
TEMPS BUT NO OTHER CHANGES ATTM.
PREV DISCUSSION... /ISSUED 657 PM CST THU FEB 21 2013/
UPDATE...FOR 00Z TAFS...
AVIATION...
LIGHT TO MODERATE RAIN SHOWERS CONTINUE TO MOVE ACROSS THE MID
STATE THIS EVENING..WITH OBS INDICATING A FEW LIGHTNING STRIKES IN
THE STRONGER CELLS. CEILINGS ARE EXPECTED TO LOWER TO AROUND 2500 FEET
AROUND MIDNIGHT AS THE PRECIP CONTINUES TO WEAKEN AND BECOME MORE
SCATTERED. RAIN SHOULD TAPER OFF FROM WEST TO EAST IN THE EARLY
MORNING HOURS ON FRIDAY WITH CEILINGS INCREASING AND CLOUDS
THINNING THROUGHOUT THE DAY.
PREV DISCUSSION... /ISSUED 313 PM CST THU FEB 21 2013/
DISCUSSION...
LATEST RADAR IMAGERY SHOWING THE WIDESPREAD RAINFALL MASSING WITH
THE LEADING EDGE APPROACHING I-65. LITTLE IN THE WAY OF LIGHTNING
RETURNS ACROSS WESTERN TN. HOWEVER...WE ARE GETTING SOME ACTIVITY
ALONG AND WEST OF THE MS RIVER. SOUTHWARD SUPPRESSION OF THE
INSTABILITY AXIS HAS OCCURRED OVER THE PAST FEW HOURS HOWEVER. THE
WIDESPREAD RAINFALL EXTENDS WESTWARD THROUGH CENTRAL AR.
THE ASSOCIATED STRONG UPPER LEVEL SYSTEM IS TRACKING ACROSS KANSAS
WITH A NORTHEASTWARD MOVEMENT. THUS...A TRACK THIS FAR TO OUR
NORTHWEST WILL LEAVE TN ON THE WARMER SIDE OF THE STORM SYSTEM AND
WE WILL CONTINUE TO SEE WET BULB TEMPS INCH UPWARD. RIGHT
NOW...THOSE WET BULB TEMPS ARE ABOVE FREEZING ACROSS THE
SOUTHWESTERN HALF OF THE MID STATE. CURRENT TEMPS ARE IN THE 40S FOR
MOST AREAS.
TONIGHT...THE RAINFALL WILL OVERSPREAD THE AREA. STILL EXPECTING
THE SHOWALTER AND THETA E INSTABILITY AXES TO MOVE ACROSS THE AREA
OVERNIGHT. SO...TSTMS WILL BE INCLUDED AS WELL. THE SHOWERS WILL END
BY FRIDAY MORNING BUT WILL LIKELY CONTINUE A SLIGHT CHANCE ACROSS
THE PLATEAU FOR FRIDAY MORNING.
PARTIAL CLEARING EXPECTED DURING THE DAY ON FRIDAY AS SOME OF THE
HIGHER CLOUDINESS HANGS ON. LOOKS LIKE A DRY BUT MILD DAY AS HEIGHTS
ARE ON THE INCREASE.
ON FRIDAY NIGHT...SOME PATCHY FOG WILL BE POSSIBLE LATE. SKIES WILL
BE PARTLY CLOUDY BUT DEWPOINTS WILL REMAIN SOMEWHAT ELEVATED. TOVER
VALUES WILL BE FAVORABLE FOR SOME PATCHY FOG DEVELOPMENT. MILD
CONDITIONS AGAIN FOR SATURDAY UNDER PCLDY SKIES.
IN THE EXT FCST...AFTER A COLD FRONT BRINGS A CHANCE OF SHOWERS TO
THE AREA ON MONDAY...WE THEN TRANSITION TO SOMEWHAT COLDER TEMPS AND
A SEMI-UNSETTLED REGIME. EURO AND GFS BOTH IN SUPPORT OF A GENERAL
TROUGHING PATTERN IN THE EAST WITH A FEW WEAK UPPER LEVEL SYSTEM
TRAVERSING THE AREA. NOTHING MUCH IN TERMS OF WINTRY WEATHER TO GET
EXCITED ABOUT AT THIS POINT. HOWEVER...I WILL ELECT TO PLACE A
RAIN/SNOW MIX IN THE FCST FOR WED NT. POPS WILL BE LOW FOR NOW.
VERSUS THE MEX GUIDANCE...SLIGHT UNDERCUTS THROUGH THE EXTENDED.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
11
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1153 PM CST THU FEB 21 2013
.UPDATE...
LATEST RADAR IMAGERY SHOWS RAIN CONTINUES TO QUICKLY MOVE OUT OF
THE FORECAST AREA...AND IS NOW GENERALLY CONFINED TO ALONG AND
EAST OF THE I-65 CORRIDOR. WILL LOWER POPS SIGNIFICANTLY FOR THE
REST OF THE NIGHT AND REMOVE MENTION OF THUNDER. NO OTHER CHANGES
AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 816 PM CST THU FEB 21 2013/
UPDATE...
LATEST RADAR IMAGERY SHOWS LARGE AREA OF LIGHT TO MODERATE RAIN
ACROSS THE MID STATE...BUT BACK EDGE CAN BE SEEN NOW EAST OF THE
MISSISSIPPI RIVER. HRRR TIMING INDICATES MOST OF THE RAIN WILL
LIKELY END WEST OF I-65 AROUND MIDNIGHT...WITH SOME RAIN
CONTINUING THROUGH THE NIGHT TO THE EAST. HAVE ADJUSTED POPS
DOWNWARD IN THE 06-12Z TIMEFRAME WITH CHANCE POPS IN THE WEST TO
CATEGORICAL IN THE EAST. WILL ALSO ADD MENTION OF ISOLATED THUNDER
TO THE SOUTHWEST HALF OF THE CWA THIS EVENING AS A FEW LIGHTNING
STRIKES HAVE BEEN NOTED FROM TIME TO TIME.
TEMPERATURES CURRENTLY RANGE FROM THE MID 30S ALONG THE KY BORDER
TO THE MID 40S ALONG THE AL BORDER. THESE VALUES WILL BE THE LOWS
FOR TONIGHT AS WAA CONTINUES TO INCREASE THROUGH THE NIGHT AND
TEMPERATURES WARM WELL INTO THE 40S AREAWIDE BY SUNRISE AND
POSSIBLY 50S IN OUR SOUTHERN ZONES. MADE MINOR ADJUSTMENTS TO
TEMPS BUT NO OTHER CHANGES ATTM.
PREV DISCUSSION... /ISSUED 657 PM CST THU FEB 21 2013/
UPDATE...FOR 00Z TAFS...
AVIATION...
LIGHT TO MODERATE RAIN SHOWERS CONTINUE TO MOVE ACROSS THE MID
STATE THIS EVENING..WITH OBS INDICATING A FEW LIGHTNING STRIKES IN
THE STRONGER CELLS. CEILINGS ARE EXPECTED TO LOWER TO AROUND 2500 FEET
AROUND MIDNIGHT AS THE PRECIP CONTINUES TO WEAKEN AND BECOME MORE
SCATTERED. RAIN SHOULD TAPER OFF FROM WEST TO EAST IN THE EARLY
MORNING HOURS ON FRIDAY WITH CEILINGS INCREASING AND CLOUDS
THINNING THROUGHOUT THE DAY.
PREV DISCUSSION... /ISSUED 313 PM CST THU FEB 21 2013/
DISCUSSION...
LATEST RADAR IMAGERY SHOWING THE WIDESPREAD RAINFALL MASSING WITH
THE LEADING EDGE APPROACHING I-65. LITTLE IN THE WAY OF LIGHTNING
RETURNS ACROSS WESTERN TN. HOWEVER...WE ARE GETTING SOME ACTIVITY
ALONG AND WEST OF THE MS RIVER. SOUTHWARD SUPPRESSION OF THE
INSTABILITY AXIS HAS OCCURRED OVER THE PAST FEW HOURS HOWEVER. THE
WIDESPREAD RAINFALL EXTENDS WESTWARD THROUGH CENTRAL AR.
THE ASSOCIATED STRONG UPPER LEVEL SYSTEM IS TRACKING ACROSS KANSAS
WITH A NORTHEASTWARD MOVEMENT. THUS...A TRACK THIS FAR TO OUR
NORTHWEST WILL LEAVE TN ON THE WARMER SIDE OF THE STORM SYSTEM AND
WE WILL CONTINUE TO SEE WET BULB TEMPS INCH UPWARD. RIGHT
NOW...THOSE WET BULB TEMPS ARE ABOVE FREEZING ACROSS THE
SOUTHWESTERN HALF OF THE MID STATE. CURRENT TEMPS ARE IN THE 40S FOR
MOST AREAS.
TONIGHT...THE RAINFALL WILL OVERSPREAD THE AREA. STILL EXPECTING
THE SHOWALTER AND THETA E INSTABILITY AXES TO MOVE ACROSS THE AREA
OVERNIGHT. SO...TSTMS WILL BE INCLUDED AS WELL. THE SHOWERS WILL END
BY FRIDAY MORNING BUT WILL LIKELY CONTINUE A SLIGHT CHANCE ACROSS
THE PLATEAU FOR FRIDAY MORNING.
PARTIAL CLEARING EXPECTED DURING THE DAY ON FRIDAY AS SOME OF THE
HIGHER CLOUDINESS HANGS ON. LOOKS LIKE A DRY BUT MILD DAY AS HEIGHTS
ARE ON THE INCREASE.
ON FRIDAY NIGHT...SOME PATCHY FOG WILL BE POSSIBLE LATE. SKIES WILL
BE PARTLY CLOUDY BUT DEWPOINTS WILL REMAIN SOMEWHAT ELEVATED. TOVER
VALUES WILL BE FAVORABLE FOR SOME PATCHY FOG DEVELOPMENT. MILD
CONDITIONS AGAIN FOR SATURDAY UNDER PCLDY SKIES.
IN THE EXT FCST...AFTER A COLD FRONT BRINGS A CHANCE OF SHOWERS TO
THE AREA ON MONDAY...WE THEN TRANSITION TO SOMEWHAT COLDER TEMPS AND
A SEMI-UNSETTLED REGIME. EURO AND GFS BOTH IN SUPPORT OF A GENERAL
TROUGHING PATTERN IN THE EAST WITH A FEW WEAK UPPER LEVEL SYSTEM
TRAVERSING THE AREA. NOTHING MUCH IN TERMS OF WINTRY WEATHER TO GET
EXCITED ABOUT AT THIS POINT. HOWEVER...I WILL ELECT TO PLACE A
RAIN/SNOW MIX IN THE FCST FOR WED NT. POPS WILL BE LOW FOR NOW.
VERSUS THE MEX GUIDANCE...SLIGHT UNDERCUTS THROUGH THE EXTENDED.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHAMBURGER
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1102 AM PST Fri Feb 22 2013
.SYNOPSIS...A strong and wet storm system will plow into the
Pacific Northwest today and tonight. This will result in windy
conditions and heavy snow in the mountains. Mountain snow showers
will likely linger into Saturday afternoon. A very short break in
the active weather is possible early Sunday, before another
frontal system brings increasing chances for rain and snow to the
region on Monday. This active late winter weather pattern will
continue through the next week.
&&
.DISCUSSION...
Morning update: The forecast from overnight is generally on track.
This update was mainly to tweak the POPs and snow amounts for this
afternoon into tonight. The HRRR model did not resolve the warm
front that moved through this morning, but does seem to be doing a
mush better job with the cold front pushing into the Pac NW this
morning. Area web cams this morning did show some light
accumulations across the Spokane Area, in Pullman and in the
valleys of the Idaho Panhandle and in the Northeast Mountains.
This initial band has shifted into the Idaho Panhandle with
increasing isentropic ascent and moisture pushing in behind the
warm front. Surface pressure gradients will increase as the cold
front pushes onshore. This will result in increasing southerly to
southeasterly winds and warm air advection. Winds at Spokane
International have already began to pick up to around 15 mph with
gusts up to around 25 mph. These winds are beginning to move into
Okanogan Valley and up into the valleys of the Northeast Mountains
and into the ID Panhandle, including up the Purcell Trench.
Surface temperatures have risen just above freezing across these
valley locations. Dew point temperatures are hovering right at or
just below freezing, so we will likely still see some snow for
places like Spokane, Pullman, Coeur d`Alene, Sandpoint and
Colville for a few more hours. However, the warm temperatures will
result in snow melting as it hits the surface and I don`t expect
much in the way of any impacts due to snow through the rest of
this morning into this evening.
Strong westerly flow will create a rain shadow just east of the
Cascades for locations like Moses Lake, Wenatchee and into Omak.
Radar shows some returns over these areas, so a few hundreds of an
inch will be possible. Chances for precipitation will decrease for
these areas after about 1 PM with the focus of the precip over the
eastern half of the forecast area, except for right along the
Cascade crest. The cold front is expected to push across the
region this evening and drier air behind the front will result in
precip shutting off across the basin into the Spokane Area through
this period. Snow amounts did not change much across the
mountains; although the Northeast Mountains may have a hard time
reaching warming criteria. I do not anticipate making any changes
to our winter weather highlights at this time even with the
slightly less accumulations in the Northeast Mountains.
We may need to consider issuing some wind highlights with 850 mb
winds up around 40 to 50 knots across the Columbia Basin into the
Palouse and into the Northeast Blue Mountains. The question will
be if we see enough mixing for these stronger winds to reach the
surface. In the warm sector of this system through this afternoon,
I do not anticipate enough mixing for an advisory. However, with
the passage of the cold front this evening, we will see a better
potential for some stronger winds mixing down to the surface. High
resolution models indicate the strongest winds and best
possibility for advisory criteria wind speeds to develop into the
Palouse and along the foothills of the Northeast Blue Mountains.
No wind highlights will be issued at this time, but will
reconsider with the afternoon package. /SVH
&&
.AVIATION...
18Z TAFS: Local radar shows the warm front moving through my
eastern zones at 0930 and will continue to push east through the
remainder of the morning. Low clouds and moderate snow will result
in mountain obscurations the remainder of the afternoon. Further
west Rain and snow showers will continue to form and push east
across the basin and into the eastern highlands through the
afternoon resulting in varying conditions. A cold front will
approach from the west with fropa at KEAT between 23z-01z and
KGEG between 03z-06z. All TAF sites will see a 2-3 hour period of
heavier precipitation and mainly as rain. Conditions are expected
to dry out behind the front. Expect increasing pre-frontal winds
out of the south-southwest through the afternoon with peak winds
with and just behind fropa this afternoon and evening. Sustained
winds of 15-20kts with gusts 25-30kts will be likely at all TAF
sites through at least 12z. /Tobin
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 39 29 40 26 37 29 / 100 60 20 10 20 40
Coeur d`Alene 39 30 38 27 37 29 / 100 100 30 10 20 40
Pullman 43 32 39 27 39 30 / 100 100 50 20 30 30
Lewiston 51 35 48 31 45 34 / 40 50 50 20 10 20
Colville 40 27 41 24 39 25 / 100 30 20 10 20 40
Sandpoint 39 29 38 25 34 28 / 100 100 50 10 30 50
Kellogg 36 29 37 26 35 28 / 100 100 80 30 30 50
Moses Lake 50 31 49 28 46 31 / 60 10 10 0 10 20
Wenatchee 45 30 46 28 43 32 / 70 40 10 0 10 20
Omak 39 23 41 19 35 26 / 60 10 10 10 20 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Storm Warning until 7 PM PST Saturday for Central
Panhandle Mountains.
Winter Weather Advisory until 10 AM PST Saturday for Lewis and
Southern Nez Perce Counties.
Winter Storm Warning until 4 AM PST Saturday for Northern
Panhandle.
WA...Winter Storm Warning until 4 AM PST Saturday for Northeast
Mountains.
Winter Weather Advisory until 10 AM PST Saturday for East Slopes
Northern Cascades.
Winter Storm Warning until 7 PM PST Saturday for Northeast Blue
Mountains.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
959 PM CST SAT FEB 23 2013
.SHORT TERM...OVERNIGHT
959 PM CST SAT FEB 23 2013
THE CLEARING LINE STOPPED ITS EASTWARD PROGRESS ACROSS SOUTHEAST
MINNESOTA AND NORTHEAST IOWA AROUND 6 PM. BOTH THE RAP AND NAM ARE
IN GOOD AGREEMENT THAT THE CLEARING WILL NOT TAKE PLACE UNTIL THE
SURFACE RIDGE AXIS SLIDES THROUGH THE AREA. THIS WILL NOT OCCUR
UNTIL AFTER 3 AM FOR THE COUNTIES ALONG THE MISSISSIPPI RIVER AND
FOR CENTRAL WISCONSIN UNTIL AFTER 6 AM. IN ADDITION...IF SKIES DID
CLEAR...RAP SOUNDINGS SHOW 10 TO 15 KNOT WINDS IN THE LOWEST 1K
FEET UNTIL 24.11Z. THIS WOULD ONLY LEAVE A COUPLE OF HOURS FOR THE
FREEZING FOG TO FORM. AS A RESULT...NOT OVERLY CONFIDENT THAT THE
WESTERN WISCONSIN WILL SEE ANY FREEZING FOG.
IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA...THERE ARE AREAS OF FOG
ALREADY...THUS THINKING THESE AREAS HAVE A MUCH BETTER CHANCE OF
SEEING THE FREEZING FOG.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
255 PM CST SAT FEB 23 2013
THE LONG TERM FORECAST OVERALL IS FAIRLY QUIET. IN THE UPPER LEVEL
PATTERN...THE ECMWF/GFS/CANADIAN CONTINUE TO FORECAST THAT THE
WEAKENING STORM SYSTEM FROM TUESDAY IS GOING TO GET BOTTLED UP OVER
THE GREAT LAKES REGION...ONLY SLOWLY MOVING TO THE EAST. THERE ARE
TWO REASONS FOR THIS...1. THE SYSTEM IS HAVING TO GET THAT THROUGH
THE RIDGING AHEAD OF IT AND 2. THERE IS ANOTHER FAIRLY POTENT
SHORTWAVE TROUGH ON ITS HEELS COMING ACROSS THE SOUTHERN U.S. THAT
EVENTUALLY GETS ABSORBED. WHAT THIS MEANS FOR OUR AREA IS THAT WE
COULD SEE A GOOD 24 HOURS OR SO OF LIGHT SNOW FROM TUESDAY NIGHT
INTO WEDNESDAY...ASSOCIATED WITH MOISTURE WRAPPING AROUND THE UPPER
LOW. RAISED PRECIPITATION CHANCES SLIGHTLY...BUT FURTHER INCREASES
ARE LIKELY NEEDED. ONCE THE UPPER LOW SHIFTS EAST...THEN HIGH
PRESSURE BUILDS IN FROM THE U.S. AND CANADIAN PLAINS. HOWEVER...THE
HIGH PRESSURE AREA DOES NOT LOOK TO BUILD INTO THE AREA UNTIL
SATURDAY AT THE EARLIEST. A COMBINATION OF UPPER RIDGING BUILDING
OVER THE WESTERN U.S. AND TROUGHING HOLDING IN PLACE OVER THE
EASTERN U.S. LOOKS TO RESULT IN THIS SETUP. THEREFORE...A PROLONGED
PERIOD OF DRY...NORTHERLY FLOW IS EXPECTED. DESPITE THE NORTHERLY
FLOW...THE 850MB TEMPS BOTTOM OUT MAYBE AROUND -10C...THUS
TEMPERATURES SHOULD HANG JUST BELOW NORMAL.
&&
.AVIATION...TONIGHT AND MONDAY
740 PM CST SAT FEB 23 2013
DURING THE PAST HOUR...THE EASTWARD PROGRESS OF THE CLEARING HAS
ABRUPTLY STOPPED. THE FOG PRODUCT EVEN SHOWS A BIT DRIFT TO THE
SOUTH. THE LATEST RAP SEEMS TO HAVE THE BEST HANDLE ON THE CURRENT
CLOUD TRENDS AND IT SHOWS LITTLE EASTWARD ADVANCEMENT OF THE
WESTERN EDGE OF THESE CLOUDS THROUGH 24.0Z /THE LAST FRAME
AVAILABLE AT THIS TIME/. DUE TO THIS DELAYED THE CLEARING INTO
LA CROSSE UNTIL 24.05Z. MAY HAVE TO EXTEND THIS EVEN MORE...BUT
WILL WAIT UNTIL THE 24.00Z MODEL RUNS COME IN.
AT THIS TIME...THE BEST CHANCE FOR DENSE FOG LOOKS TO BE ACROSS
SOUTHEAST MINNESOTA AND NORTHEAST IOWA. KRST WILL LIKELY DEVELOP
DENSE FOG AROUND 24.09Z AND THEN PERSIST THROUGH 24.15Z. EVEN IF
KLSE DOES CLEAR...STILL NOT QUITE AS SURE THERE SINCE THE RAP
SOUNDINGS CONTINUE TO SHOW 10 TO 15 KNOTS THROUGH 24.11Z WITHIN
THE LOWEST 1K FEET...AND THEN THE WINDS IN THIS LAYER DROP TO 6
KNOTS OR LESS. IF THESE WINDS ARE CORRECT...A BIT CONCERNED THAT
THE FOG MAY NOT DEVELOP. AS A RESULT...WILL JUST DECREASE THE
VISIBILITIES TO 2 MILES AFTER 24.09Z.
THE FOG WILL DISSIPATE IN THE 14-16Z TIME FRAME WITH CONDITIONS
GRADUALLY IMPROVING TO MVFR BY MID SUNDAY MORNING AND EVENTUALLY
OF VFR BY THE LATE MORNING HOURS. A LAYER OF 10-15K FEET CLOUDS
WILL MOVE INTO THE AREA DURING THE LATE MORNING AND CONTINUE INTO
THE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
255 PM CST SAT FEB 23 2013
WI...FREEZING FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST SUNDAY
FOR WIZ032>034-041-042-053>055-061.
MN...FREEZING FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST SUNDAY
FOR MNZ079-086>088-094>096.
IA...FREEZING FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST SUNDAY
FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...BOYNE
LONG TERM...AJ
AVIATION...BOYNE
SKIES BY SUNDAY AFTERNOON. READ THE MAIN FORECAST DISCUSSION ABOVE
FOR SKY COVER UNCERTAINTIES.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...HENTZ
TONIGHT/SUNDAY AND AVIATION/MARINE...MRC
SUNDAY NIGHT THROUGH SATURDAY...DAVIS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
740 PM CST SAT FEB 23 2013
.SHORT TERM...TONIGHT THROUGH TUESDAY
255 PM CST SAT FEB 23 2013
MAIN FORECAST CONCERNS ARE ON FREEZING FOG POTENTIAL TONIGHT AND IF
AND WHEN SNOW CAN MOVE IN FOR EARLY NEXT WEEK.
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED TROUGHING DIGGING DOWN THROUGH THE U.S. ROCKIES...
RIDGING BUILDING HEAD OF THIS TROUGH INTO THE CENTRAL PLAINS AND
AN UPPER LOW ENCOMPASSING MUCH OF THE WESTERN GREAT LAKES REGION.
THIS UPPER LOW COMBINED WITH MOISTURE AND WEAK SHORTWAVES ROTATING
AROUND IT HAS KEPT CLOUDS IN PLACE ACROSS THE NORTHWEST HALF OF
THE FORECAST AREA. 12Z GRB AND MPX SOUNDINGS REFLECT THE
MOISTURE...TRAPPED BELOW A SUBSIDENCE INVERSION BETWEEN 750-800MB.
THERE WERE SOME SNOW SHOWERS/FLURRIES EARLIER...BUT THESE HAVE
SINCE DISSIPATED FOR THE MOST PART. TO THE WEST...CLEARING HAS
BEEN WORKING INTO SOUTHWESTERN PORTIONS OF THE FORECAST AREA FROM
THE PLAINS AND IOWA. 12Z ABR AND OAX SOUNDINGS SHOWED THE DRIER
AIR WITH DEWPOINT DEPRESSIONS OF 5C OR MORE FROM JUST ABOVE THE
SURFACE TO 300MB. AT THE SURFACE WAS A STRONG RADIATIONAL
INVERSION THAT WAS SATURATED...REFLECTING THE FOG THAT OCCURRED.
BOTH LOCATIONS WERE UNDER A RIDGE OF HIGH PRESSURE WHICH HAS
SHIFTED EAST TO CENTRAL PORTIONS OF IOWA AND MINNESOTA. AIRMASS
REMAINS COOL WITH 850MB TEMPS FROM 12Z SOUNDINGS BETWEEN -10C AND
-12C...OR 1 STANDARD DEVIATION BELOW NORMAL.
SHORT TERM HIGHLIGHTS/CONCERNS...
TONIGHT - CLEARING/TEMPS/FOG - MODELS ARE STRUGGLING A BIT WITH THE
CLEARING IMPACTING WESTERN PORTIONS OF THE FORECAST AREA. 925MB RH
FIELDS FROM THE RAP/NAM/GFS WOULD ALL SUGGEST A PESSIMISTIC IDEA
WITH CLOUDS HANGING AROUND MUCH OF THE NIGHT ACROSS THE FORECAST
AREA. HOWEVER...AS NOTED BY SATELLITE IMAGERY...WE HAVE PARTIALLY
CLEARED OUT ALREADY OVER THE SOUTHWEST HALF OF THE AREA. WITH THE
SURFACE RIDGE MOVING OVER THE ENTIRE FORECAST AREA BY 12Z
SUNDAY...THINKING THE CLEARING SHOULD CONTINUE TO PROGRESS EAST. THE
CLEARING SKIES IN THE EVENING COMBINED WITH LIGHT WINDS...DRIER
AIR MOVING IN ALOFT AND THE FRESH SNOW PACK MAKE A GREAT SITUATION
FOR RADIATIONAL COOLING. WENT TOWARDS THE COLDER GFS40 2 METER
TEMPERATURE GUIDANCE FOR LOWS...WHICH WAS FAIRLY SIMILAR TO THE
PREVIOUS FORECAST. THE LOWS...WHICH DROP INTO THE SINGLE DIGITS
ABOVE ZERO SOUTHWEST OF I-94...COMBINED WITH THE CURRENT AFTERNOON
DEWPOINTS IN THE 15 TO 20 RANGE YIELD A FAVORABLE FOG AND VERY LOW
STRATUS SITUATION VIA CROSS-OVER APPROACH. SREF PROBABILITIES OF
LESS THAN 1 MILE SHOW A RAPID DEVELOPMENT AND EXPANSION OF FOG
THROUGH THE EVENING ACROSS MINNESOTA AND IOWA...THEN SPREADING EAST
INTO WISCONSIN. LATEST HRRR RUNS ARE VERY SIMILAR. GIVEN THE
TEMPERATURES...FREEZING FOG WITH RIMING ON UNTREATED SURFACES WOULD
OCCUR. HAVE ADDED THE FOG TO THE FORECAST...WITH THE MOST COVERAGE
WEST AND SOUTH OF I-94 WHERE CONFIDENCE IS HIGHEST. IN ADDITION...
AFTER COLLABORATION FROM SURROUNDING OFFICES...ISSUED A FREEZING FOG
ADVISORY FOR MUCH OF THE FORECAST AREA LINING UP WITH THE GENERAL
MINIMUM IN LOW TEMPS AND CLEARING AREA. IT IS POSSIBLE DENSE FOG
COULD OCCUR AS WELL...BUT CONFIDENCE IS TOO LOW TO GO WITH THAT
ADVISORY TYPE AT THIS TIME. IF DENSE FOG WERE TO OCCUR...ALONG
AND WEST OF HIGHWAY 52 WOULD APPEAR TO HAVE THE BEST CHANCE. LATER
SHIFTS MAY NEED TO REPLACE SOME OF THE FREEZING FOG ADVISORY WITH
DENSE FOG IF CONFIDENCE OF GROWS. ANY FOG/STRATUS MAY TAKE SOME
TIME TO MIX OUT...BUT THE HIGHER LATE FEBRUARY SUN ANGLE SHOULD
ALLOW IT TO CLEAR OUT BY 18Z.
MONDAY THROUGH TUESDAY - WINTER STORM COMING OUT OF THE SOUTHERN
PLAINS - WHAT HAS BEEN CONSISTENT...
1. THE UPPER TROUGH RESPONSIBLE FOR THE STORM...CURRENTLY THE BASE
OF THE TROUGH CROSSING THE ROCKIES...IS FORECAST TO DIG INTO TEXAS
AND OKLAHOMA ON MONDAY...FARTHER SOUTH THAN THE RECENT STORM.
2. STRONG RIDGING DEVELOPS AHEAD OF UPPER TROUGH FROM THE
MID-ATLANTIC TOWARDS OUR FORECAST AREA.
3. MODEL TRENDS OVERALL FROM THE GFS...CANADIAN AND ECMWF THE PAST
FEW DAYS HAVE BEEN SLOWER LIFTING THE STORM OUT OF THE SOUTHERN
PLAINS AND MORE TO THE SOUTHEAST...REPRESENTATIVE OF THE IMPACT THE
STRONG RIDGING AHEAD OF IT IS HAVING.
WHAT HAS BEEN INCONSISTENT...WHETHER THE HEAVIER BUT WEAKENING
DEFORMATION BAND ON THE NORTHWEST SIDE OF THE SYSTEM WILL IMPACT
PORTIONS OF THE AREA...OR STAY TO THE SOUTHEAST. TAKE FOR EXAMPLE
THE 23.12Z CANADIAN...WHICH OVER THE PAST FEW DAYS HAS BEEN A
SOUTHEAST SOLUTION...NOW HAS SHIFTED NORTHWEST TOWARDS THE 23.12Z
GFS WHICH HAS BEEN A MORE NORTHWEST SOLUTION ALL ALONG. THE 23.12Z
NAM HAS FOLLOWED SIMILARLY TO THE CANADIAN. LASTLY...THE 23.12Z
ECMWF HAS SHIFTED BACK MORE NORTHWEST COMPARED TO ITS 00Z RUN.
NO MATTER WHAT MODEL SOLUTION IS FOLLOWED...ANY PRECIPITATION
ASSOCIATED WITH THE SYSTEM...EITHER FROM THE DEFORMATION BAND OR
FROM AN INVERTED TROUGH EXTENDING NORTH FROM THE LOW...LOOKS TO HOLD
OFF TO OUR WEST AND SOUTH THROUGH 12Z TUESDAY. THIS MAKES SENSE WITH
THE BUILDING RIDGING ALOFT AND DRY AIR FLOW FROM HIGH PRESSURE
HEADING EAST INTO THE GREAT LAKES. IN FACT...THE DRY AIR FLOW ONLY
INTENSIFIES AS THE SYSTEM LIFTS NORTHEAST DUE TO THE WINDS
INCREASING. THUS...HAVE A DRY FORECAST FOR MONDAY AND MONDAY NIGHT.
FOR TUESDAY...FOLLOWED A CONSENSUS APPROACH ON PRECIPITATION CHANCES
FOR NOW GIVEN THE MODEL INCONSISTENCIES ON THE DEFORMATION BAND.
STILL...THE BEST CHANCES FOR SNOW ON TUESDAY WOULD OCCUR IN THE
SOUTHEAST 1/3 OF THE AREA. AMOUNTS RIGHT NOW WOULD BE MAYBE WORTHY
OF AN ADVISORY AT MOST. THE SYSTEM JUST REALLY WEAKENS AS IT LIFTS
NORTHEAST AND RUNS INTO THE RIDGE.
OUTSIDE OF THE SHORT TERM HIGHLIGHTS ABOVE...EXPECT THE MOST
SUNSHINE TOMORROW AFTER THE MORNING FOG/STRATUS MIX OUT. AS WE HEAD
INTO MONDAY AND TUESDAY...CIRRUS WILL DOMINATE THE AREA AND
EVENTUALLY LOWER CLOUDS COME TUESDAY. DESPITE THE HIGH
CLOUDS...THERE SHOULD BE ENOUGH SUN GETTING THROUGH TO COMBINE WITH
SLIGHTLY WARMING 925MB TEMPS TO BRING TEMPERATURES UP A LITTLE EACH
DAY. EVEN ON TUESDAY...WHEN THE SYSTEM APPROACHES...925MB TEMPS ARE
ONLY -2 TO -4C.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
255 PM CST SAT FEB 23 2013
THE LONG TERM FORECAST OVERALL IS FAIRLY QUIET. IN THE UPPER LEVEL
PATTERN...THE ECMWF/GFS/CANADIAN CONTINUE TO FORECAST THAT THE
WEAKENING STORM SYSTEM FROM TUESDAY IS GOING TO GET BOTTLED UP OVER
THE GREAT LAKES REGION...ONLY SLOWLY MOVING TO THE EAST. THERE ARE
TWO REASONS FOR THIS...1. THE SYSTEM IS HAVING TO GET THAT THROUGH
THE RIDGING AHEAD OF IT AND 2. THERE IS ANOTHER FAIRLY POTENT
SHORTWAVE TROUGH ON ITS HEELS COMING ACROSS THE SOUTHERN U.S. THAT
EVENTUALLY GETS ABSORBED. WHAT THIS MEANS FOR OUR AREA IS THAT WE
COULD SEE A GOOD 24 HOURS OR SO OF LIGHT SNOW FROM TUESDAY NIGHT
INTO WEDNESDAY...ASSOCIATED WITH MOISTURE WRAPPING AROUND THE UPPER
LOW. RAISED PRECIPITATION CHANCES SLIGHTLY...BUT FURTHER INCREASES
ARE LIKELY NEEDED. ONCE THE UPPER LOW SHIFTS EAST...THEN HIGH
PRESSURE BUILDS IN FROM THE U.S. AND CANADIAN PLAINS. HOWEVER...THE
HIGH PRESSURE AREA DOES NOT LOOK TO BUILD INTO THE AREA UNTIL
SATURDAY AT THE EARLIEST. A COMBINATION OF UPPER RIDGING BUILDING
OVER THE WESTERN U.S. AND TROUGHING HOLDING IN PLACE OVER THE
EASTERN U.S. LOOKS TO RESULT IN THIS SETUP. THEREFORE...A PROLONGED
PERIOD OF DRY...NORTHERLY FLOW IS EXPECTED. DESPITE THE NORTHERLY
FLOW...THE 850MB TEMPS BOTTOM OUT MAYBE AROUND -10C...THUS
TEMPERATURES SHOULD HANG JUST BELOW NORMAL.
&&
.AVIATION...TONIGHT AND MONDAY
740 PM CST SAT FEB 23 2013
DURING THE PAST HOUR...THE EASTWARD PROGRESS OF THE CLEARING HAS
ABRUPTLY STOPPED. THE FOG PRODUCT EVEN SHOWS A BIT DRIFT TO THE
SOUTH. THE LATEST RAP SEEMS TO HAVE THE BEST HANDLE ON THE CURRENT
CLOUD TRENDS AND IT SHOWS LITTLE EASTWARD ADVANCEMENT OF THE
WESTERN EDGE OF THESE CLOUDS THROUGH 24.0Z /THE LAST FRAME
AVAILABLE AT THIS TIME/. DUE TO THIS DELAYED THE CLEARING INTO
LA CROSSE UNTIL 24.05Z. MAY HAVE TO EXTEND THIS EVEN MORE...BUT
WILL WAIT UNTIL THE 24.00Z MODEL RUNS COME IN.
AT THIS TIME...THE BEST CHANCE FOR DENSE FOG LOOKS TO BE ACROSS
SOUTHEAST MINNESOTA AND NORTHEAST IOWA. KRST WILL LIKELY DEVELOP
DENSE FOG AROUND 24.09Z AND THEN PERSIST THROUGH 24.15Z. EVEN IF
KLSE DOES CLEAR...STILL NOT QUITE AS SURE THERE SINCE THE RAP
SOUNDINGS CONTINUE TO SHOW 10 TO 15 KNOTS THROUGH 24.11Z WITHIN
THE LOWEST 1K FEET...AND THEN THE WINDS IN THIS LAYER DROP TO 6
KNOTS OR LESS. IF THESE WINDS ARE CORRECT...A BIT CONCERNED THAT
THE FOG MAY NOT DEVELOP. AS A RESULT...WILL JUST DECREASE THE
VISIBILITIES TO 2 MILES AFTER 24.09Z.
THE FOG WILL DISSIPATE IN THE 14-16Z TIME FRAME WITH CONDITIONS
GRADUALLY IMPROVING TO MVFR BY MID SUNDAY MORNING AND EVENTUALLY
OF VFR BY THE LATE MORNING HOURS. A LAYER OF 10-15K FEET CLOUDS
WILL MOVE INTO THE AREA DURING THE LATE MORNING AND CONTINUE INTO
THE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
255 PM CST SAT FEB 23 2013
WI...FREEZING FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST SUNDAY
FOR WIZ032>034-041-042-053>055-061.
MN...FREEZING FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST SUNDAY
FOR MNZ079-086>088-094>096.
IA...FREEZING FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST SUNDAY
FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
546 PM CST SAT FEB 23 2013
.SHORT TERM...TONIGHT THROUGH TUESDAY
255 PM CST SAT FEB 23 2013
MAIN FORECAST CONCERNS ARE ON FREEZING FOG POTENTIAL TONIGHT AND IF
AND WHEN SNOW CAN MOVE IN FOR EARLY NEXT WEEK.
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED TROUGHING DIGGING DOWN THROUGH THE U.S. ROCKIES...
RIDGING BUILDING HEAD OF THIS TROUGH INTO THE CENTRAL PLAINS AND
AN UPPER LOW ENCOMPASSING MUCH OF THE WESTERN GREAT LAKES REGION.
THIS UPPER LOW COMBINED WITH MOISTURE AND WEAK SHORTWAVES ROTATING
AROUND IT HAS KEPT CLOUDS IN PLACE ACROSS THE NORTHWEST HALF OF
THE FORECAST AREA. 12Z GRB AND MPX SOUNDINGS REFLECT THE
MOISTURE...TRAPPED BELOW A SUBSIDENCE INVERSION BETWEEN 750-800MB.
THERE WERE SOME SNOW SHOWERS/FLURRIES EARLIER...BUT THESE HAVE
SINCE DISSIPATED FOR THE MOST PART. TO THE WEST...CLEARING HAS
BEEN WORKING INTO SOUTHWESTERN PORTIONS OF THE FORECAST AREA FROM
THE PLAINS AND IOWA. 12Z ABR AND OAX SOUNDINGS SHOWED THE DRIER
AIR WITH DEWPOINT DEPRESSIONS OF 5C OR MORE FROM JUST ABOVE THE
SURFACE TO 300MB. AT THE SURFACE WAS A STRONG RADIATIONAL
INVERSION THAT WAS SATURATED...REFLECTING THE FOG THAT OCCURRED.
BOTH LOCATIONS WERE UNDER A RIDGE OF HIGH PRESSURE WHICH HAS
SHIFTED EAST TO CENTRAL PORTIONS OF IOWA AND MINNESOTA. AIRMASS
REMAINS COOL WITH 850MB TEMPS FROM 12Z SOUNDINGS BETWEEN -10C AND
-12C...OR 1 STANDARD DEVIATION BELOW NORMAL.
SHORT TERM HIGHLIGHTS/CONCERNS...
TONIGHT - CLEARING/TEMPS/FOG - MODELS ARE STRUGGLING A BIT WITH THE
CLEARING IMPACTING WESTERN PORTIONS OF THE FORECAST AREA. 925MB RH
FIELDS FROM THE RAP/NAM/GFS WOULD ALL SUGGEST A PESSIMISTIC IDEA
WITH CLOUDS HANGING AROUND MUCH OF THE NIGHT ACROSS THE FORECAST
AREA. HOWEVER...AS NOTED BY SATELLITE IMAGERY...WE HAVE PARTIALLY
CLEARED OUT ALREADY OVER THE SOUTHWEST HALF OF THE AREA. WITH THE
SURFACE RIDGE MOVING OVER THE ENTIRE FORECAST AREA BY 12Z
SUNDAY...THINKING THE CLEARING SHOULD CONTINUE TO PROGRESS EAST. THE
CLEARING SKIES IN THE EVENING COMBINED WITH LIGHT WINDS...DRIER
AIR MOVING IN ALOFT AND THE FRESH SNOW PACK MAKE A GREAT SITUATION
FOR RADIATIONAL COOLING. WENT TOWARDS THE COLDER GFS40 2 METER
TEMPERATURE GUIDANCE FOR LOWS...WHICH WAS FAIRLY SIMILAR TO THE
PREVIOUS FORECAST. THE LOWS...WHICH DROP INTO THE SINGLE DIGITS
ABOVE ZERO SOUTHWEST OF I-94...COMBINED WITH THE CURRENT AFTERNOON
DEWPOINTS IN THE 15 TO 20 RANGE YIELD A FAVORABLE FOG AND VERY LOW
STRATUS SITUATION VIA CROSS-OVER APPROACH. SREF PROBABILITIES OF
LESS THAN 1 MILE SHOW A RAPID DEVELOPMENT AND EXPANSION OF FOG
THROUGH THE EVENING ACROSS MINNESOTA AND IOWA...THEN SPREADING EAST
INTO WISCONSIN. LATEST HRRR RUNS ARE VERY SIMILAR. GIVEN THE
TEMPERATURES...FREEZING FOG WITH RIMING ON UNTREATED SURFACES WOULD
OCCUR. HAVE ADDED THE FOG TO THE FORECAST...WITH THE MOST COVERAGE
WEST AND SOUTH OF I-94 WHERE CONFIDENCE IS HIGHEST. IN ADDITION...
AFTER COLLABORATION FROM SURROUNDING OFFICES...ISSUED A FREEZING FOG
ADVISORY FOR MUCH OF THE FORECAST AREA LINING UP WITH THE GENERAL
MINIMUM IN LOW TEMPS AND CLEARING AREA. IT IS POSSIBLE DENSE FOG
COULD OCCUR AS WELL...BUT CONFIDENCE IS TOO LOW TO GO WITH THAT
ADVISORY TYPE AT THIS TIME. IF DENSE FOG WERE TO OCCUR...ALONG
AND WEST OF HIGHWAY 52 WOULD APPEAR TO HAVE THE BEST CHANCE. LATER
SHIFTS MAY NEED TO REPLACE SOME OF THE FREEZING FOG ADVISORY WITH
DENSE FOG IF CONFIDENCE OF GROWS. ANY FOG/STRATUS MAY TAKE SOME
TIME TO MIX OUT...BUT THE HIGHER LATE FEBRUARY SUN ANGLE SHOULD
ALLOW IT TO CLEAR OUT BY 18Z.
MONDAY THROUGH TUESDAY - WINTER STORM COMING OUT OF THE SOUTHERN
PLAINS - WHAT HAS BEEN CONSISTENT...
1. THE UPPER TROUGH RESPONSIBLE FOR THE STORM...CURRENTLY THE BASE
OF THE TROUGH CROSSING THE ROCKIES...IS FORECAST TO DIG INTO TEXAS
AND OKLAHOMA ON MONDAY...FARTHER SOUTH THAN THE RECENT STORM.
2. STRONG RIDGING DEVELOPS AHEAD OF UPPER TROUGH FROM THE
MID-ATLANTIC TOWARDS OUR FORECAST AREA.
3. MODEL TRENDS OVERALL FROM THE GFS...CANADIAN AND ECMWF THE PAST
FEW DAYS HAVE BEEN SLOWER LIFTING THE STORM OUT OF THE SOUTHERN
PLAINS AND MORE TO THE SOUTHEAST...REPRESENTATIVE OF THE IMPACT THE
STRONG RIDGING AHEAD OF IT IS HAVING.
WHAT HAS BEEN INCONSISTENT...WHETHER THE HEAVIER BUT WEAKENING
DEFORMATION BAND ON THE NORTHWEST SIDE OF THE SYSTEM WILL IMPACT
PORTIONS OF THE AREA...OR STAY TO THE SOUTHEAST. TAKE FOR EXAMPLE
THE 23.12Z CANADIAN...WHICH OVER THE PAST FEW DAYS HAS BEEN A
SOUTHEAST SOLUTION...NOW HAS SHIFTED NORTHWEST TOWARDS THE 23.12Z
GFS WHICH HAS BEEN A MORE NORTHWEST SOLUTION ALL ALONG. THE 23.12Z
NAM HAS FOLLOWED SIMILARLY TO THE CANADIAN. LASTLY...THE 23.12Z
ECMWF HAS SHIFTED BACK MORE NORTHWEST COMPARED TO ITS 00Z RUN.
NO MATTER WHAT MODEL SOLUTION IS FOLLOWED...ANY PRECIPITATION
ASSOCIATED WITH THE SYSTEM...EITHER FROM THE DEFORMATION BAND OR
FROM AN INVERTED TROUGH EXTENDING NORTH FROM THE LOW...LOOKS TO HOLD
OFF TO OUR WEST AND SOUTH THROUGH 12Z TUESDAY. THIS MAKES SENSE WITH
THE BUILDING RIDGING ALOFT AND DRY AIR FLOW FROM HIGH PRESSURE
HEADING EAST INTO THE GREAT LAKES. IN FACT...THE DRY AIR FLOW ONLY
INTENSIFIES AS THE SYSTEM LIFTS NORTHEAST DUE TO THE WINDS
INCREASING. THUS...HAVE A DRY FORECAST FOR MONDAY AND MONDAY NIGHT.
FOR TUESDAY...FOLLOWED A CONSENSUS APPROACH ON PRECIPITATION CHANCES
FOR NOW GIVEN THE MODEL INCONSISTENCIES ON THE DEFORMATION BAND.
STILL...THE BEST CHANCES FOR SNOW ON TUESDAY WOULD OCCUR IN THE
SOUTHEAST 1/3 OF THE AREA. AMOUNTS RIGHT NOW WOULD BE MAYBE WORTHY
OF AN ADVISORY AT MOST. THE SYSTEM JUST REALLY WEAKENS AS IT LIFTS
NORTHEAST AND RUNS INTO THE RIDGE.
OUTSIDE OF THE SHORT TERM HIGHLIGHTS ABOVE...EXPECT THE MOST
SUNSHINE TOMORROW AFTER THE MORNING FOG/STRATUS MIX OUT. AS WE HEAD
INTO MONDAY AND TUESDAY...CIRRUS WILL DOMINATE THE AREA AND
EVENTUALLY LOWER CLOUDS COME TUESDAY. DESPITE THE HIGH
CLOUDS...THERE SHOULD BE ENOUGH SUN GETTING THROUGH TO COMBINE WITH
SLIGHTLY WARMING 925MB TEMPS TO BRING TEMPERATURES UP A LITTLE EACH
DAY. EVEN ON TUESDAY...WHEN THE SYSTEM APPROACHES...925MB TEMPS ARE
ONLY -2 TO -4C.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
255 PM CST SAT FEB 23 2013
THE LONG TERM FORECAST OVERALL IS FAIRLY QUIET. IN THE UPPER LEVEL
PATTERN...THE ECMWF/GFS/CANADIAN CONTINUE TO FORECAST THAT THE
WEAKENING STORM SYSTEM FROM TUESDAY IS GOING TO GET BOTTLED UP OVER
THE GREAT LAKES REGION...ONLY SLOWLY MOVING TO THE EAST. THERE ARE
TWO REASONS FOR THIS...1. THE SYSTEM IS HAVING TO GET THAT THROUGH
THE RIDGING AHEAD OF IT AND 2. THERE IS ANOTHER FAIRLY POTENT
SHORTWAVE TROUGH ON ITS HEELS COMING ACROSS THE SOUTHERN U.S. THAT
EVENTUALLY GETS ABSORBED. WHAT THIS MEANS FOR OUR AREA IS THAT WE
COULD SEE A GOOD 24 HOURS OR SO OF LIGHT SNOW FROM TUESDAY NIGHT
INTO WEDNESDAY...ASSOCIATED WITH MOISTURE WRAPPING AROUND THE UPPER
LOW. RAISED PRECIPITATION CHANCES SLIGHTLY...BUT FURTHER INCREASES
ARE LIKELY NEEDED. ONCE THE UPPER LOW SHIFTS EAST...THEN HIGH
PRESSURE BUILDS IN FROM THE U.S. AND CANADIAN PLAINS. HOWEVER...THE
HIGH PRESSURE AREA DOES NOT LOOK TO BUILD INTO THE AREA UNTIL
SATURDAY AT THE EARLIEST. A COMBINATION OF UPPER RIDGING BUILDING
OVER THE WESTERN U.S. AND TROUGHING HOLDING IN PLACE OVER THE
EASTERN U.S. LOOKS TO RESULT IN THIS SETUP. THEREFORE...A PROLONGED
PERIOD OF DRY...NORTHERLY FLOW IS EXPECTED. DESPITE THE NORTHERLY
FLOW...THE 850MB TEMPS BOTTOM OUT MAYBE AROUND -10C...THUS
TEMPERATURES SHOULD HANG JUST BELOW NORMAL.
&&
.AVIATION...TONIGHT AND SUNDAY
545 PM CST SAT FEB 23 2013
DURING THE PAST HOUR...SKIES HAVE CLEARED AT KRST. AS SUBSIDENCE
INCREASES IN THE WAKE OF A SHORT WAVE AND THE WINDS SHIFT TO
WEST...EXPECT THAT THIS CLEARING WILL REACH KLSE AROUND 24.02Z.
WITH CLEARING AND WINDS BECOMING LIGHT AND VARIABLE AT BOTH TAF
SITES. AREAS OF FOG ARE EXPECTED TO DEVELOP. THIS FOG WILL BE
LIKELY DENSE ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA. KRST
WILL LIKELY DEVELOP DENSE FOG AROUND 24.09Z AND THEN PERSIST
THROUGH 24.15Z. STILL NOT QUITE AS SURE AT KLSE. THE RAP SOUNDINGS
SUGGEST SHOW 10 TO 15 KNOTS THROUGH 24.11Z WITHIN THE LOWEST 1K
FEET...AND THEN THE WINDS IN THIS LAYER DROP TO 6 KNOTS OR LESS.
IF THESE WINDS ARE CORRECT...A BIT CONCERNED THAT THE FOG MAY NOT
DEVELOP. AS A RESULT...WILL JUST DECREASE THE VISIBILITIES TO
2 MILES AFTER 24.09Z.
THE FOG WILL DISSIPATE IN THE 14-16Z TIME FRAME WITH CONDITIONS
GRADUALLY IMPROVING TO MVFR BY MID SUNDAY MORNING AND EVENTUALLY
OF VFR BY THE LATE MORNING HOURS. A LAYER OF 10-15K FEET CLOUDS
WILL MOVE INTO THE AREA DURING THE LATE MORNING AND CONTINUE INTO
THE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
255 PM CST SAT FEB 23 2013
WI...FREEZING FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST SUNDAY
FOR WIZ032>034-041-042-053>055-061.
MN...FREEZING FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST SUNDAY
FOR MNZ079-086>088-094>096.
IA...FREEZING FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST SUNDAY
FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
318 PM CST FRI FEB 22 2013
.SHORT TERM...TONIGHT THROUGH MONDAY
318 PM CST FRI FEB 22 2013
FORECAST CONCERNS REMAIN ON HOW LONG THE LIGHT SNOW WILL LINGER
ACROSS NORTH CENTRAL WISCONSIN THIS EVENING AND SNOW CHANCES LATE
TONIGHT THROUGH SATURDAY. FOCUS THEN TURNS TO THE LOW PRESSURE
SYSTEM TRACKING ACROSS THE CENTRAL PLAINS SUNDAY NIGHT AND
POSSIBLY LIFTING NORTHEAST AND IMPACTING THE UPPER MISSISSIPPI
RIVER VALLEY.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS PLACED A CLOSED
500 MB LOW CENTERED OVER EXTREME SOUTHEAST MINNESOTA/WEST CENTRAL
WISCONSIN...MOVING NORTHEAST. THIS LOW IS RESPONSIBLE FOR PRODUCING
2 TO 10 INCHES OF SNOWFALL ACROSS THE FORECAST AREA FROM LATE
THURSDAY NIGHT THROUGH THE DAY TODAY.
LIGHT SNOW WILL CONTINUE OVER NORTH CENTRAL WISCONSIN EARLY THIS
EVENING BEFORE TAPERING OFF. ANY LINGERING SNOW ACROSS THE REST OF
THE FORECAST AREA SHOULD TAPER OFF TO VERY LIGHT SNOW OR FLURRIES
DURING THE OVERNIGHT HOURS. THE LOW IS EXPECTED TO MOVE INTO
NORTHEAST WISCONSIN LATE TONIGHT AND EVENTUALLY INTO EASTERN UPPER
MICHIGAN DURING THE DAY ON SATURDAY. CYCLONIC FLOW OVER THE FORECAST
AREA ON THE BACK SIDE OF THE DEPARTING LOW WILL BRINGING CONTINUED
CHANCES FOR LIGHT SNOW OR FLURRIES ACROSS MUCH OF THE FORECAST AREA
THROUGH SATURDAY MORNING. CHANCES FOR LIGHT SNOW WILL SHIFT
NORTHEAST EAST MAINLY TO ALONG AND NORTHEAST OF THE INTERSTATE 94
CORRIDOR SATURDAY AFTERNOON. LOCATIONS ACROSS NORTH CENTRAL
WISCONSIN COULD RECEIVE AROUND AN INCH OF SNOWFALL BEFORE THIS
ACTIVITY EXITS THE AREA SATURDAY NIGHT. HIGH PRESSURE IS EXPECTED
TO BUILD INTO THE FORECAST AREA LATE SATURDAY NIGHT INTO SUNDAY
PROVIDING QUIET WEATHER. PLAN ON PARTLY SUNNY SKIES ON SUNDAY WITH
THE HIGH IN CONTROL. LOOK FOR HIGHS ON SATURDAY TO RANGE FROM THE
MID TO UPPER 20S OVER SOUTHEAST MINNESOTA INTO NORTH CENTRAL WISCONSIN
TO AROUND 30 OVER FAR SOUTHWEST WISCONSIN. LOWS SATURDAY NIGHT ARE
EXPECTED TO RANGE FROM THE LOWER TEENS OVER NORTHEAST IOWA TO THE
SINGLE DIGITS ABOVE ZERO OVER NORTH CENTRAL WISCONSIN. HIGHS ON
SUNDAY WILL BE NEAR NORMAL...WITH HIGHS IN THE UPPER 20 TO LOWER
30S.
A VIGOROUS TROUGH WILL MOVE OUT OF THE CENTRAL ROCKIES AND FOUR
CORNERS REGION AND INTO THE CENTRAL PLAINS SUNDAY NIGHT INTO MONDAY.
22.12 FORECAST MODELS ARE IN REASONABLE AGREEMENT ON MONDAY SHOWING
THE TROUGH ADVANCING EAST INTO THE CENTRAL PLAINS AND DEEPENING INTO
A STRONG UPPER LOW. SOLUTIONS START TO DIVERGE SLIGHTLY LEADING INTO
MONDAY NIGHT ON THE EXACT TRACK THIS SYSTEM WILL FOLLOW. THE TROUGH
COULD JUST EDGE INTO LOCATIONS ALONG AND WEST OF THE MISSISSIPPI
RIVER LATE ON MONDAY SO WILL MAINTAIN CHANCES FOR LIGHT SNOW ACROSS
THESE AREAS.
.LONG TERM...MONDAY NIGHT THROUGH THURSDAY
318 PM CST FRI FEB 22 2013
22.12 MEDIUM RANGE MODELS IN SLIGHTLY BETTER AGREEMENT TODAY
REGARDING THE TRACK OF THE STRONG UPPER LOW MONDAY NIGHT INTO
TUESDAY. THE GFS AND ECMWF BRINGING ACCUMULATING SNOW TO THE
FORECAST AREA WHILE THE GEM TAKES THE LOW WELL SOUTH OF THE FORECAST
AREA. THE GFS AND ECMWF TAKE THE LOW ACROSS CENTRAL ILLINOIS ON
TUESDAY AND INTO LOWER MICHIGAN TUESDAY NIGHT. THE GEM TAKES THE LOW
UP THE OHIO RIVER VALLEY. MEANWHILE...THE NAM OFFERS A VERY SIMILAR
SOLUTION TO THE GEM. UNCERTAINTY REMAINS ON THE TRACK OF THE STORM.
DECIDED TO LEAN TOWARD THE ECMWF AND GFS SINCE THE ECMWF TENDS TO
HAVE A BETTER TRACK RECORD WITH THE SYSTEMS FURTHER OUT IT IN
TIME...INCREASING PRECIPITATION CHANCES ACROSS NORTHEAST IOWA INTO
SOUTHWEST AND CENTRAL WISCONSIN. WILL HAVE TO MAINTAIN A CLOSE WATCH
ON THIS SYSTEM SINCE IT HAS THE POTENTIAL TO PRODUCE SIGNIFICANT
SNOWFALL. CHANCES FOR LIGHT SNOW ARE EXPECTED TO LINGER WEDNESDAY
INTO THURSDAY AS THE LOW PUSHES INTO THE EASTERN GREAT LAKES AND
STALLS.
&&
.AVIATION...THROUGH 18Z SATURDAY
1211 PM CST FRI FEB 22 2013
TRICKY AVIATION FORECAST WITH SEVERAL DIFFERENT WEATHER CONDITIONS
TO TEND WITH. SURFACE LOW WILL DRIFT TO THE EAST THIS
AFTERNOON...WITH UPPER LEVEL FEATURE MOVING NEARLY OVERHEAD. THIS
KEEPS CYCLONIC FLOW OVER KRST/KLSE THROUGH AT LEAST SATURDAY. AT
KLSE...LIGHT SNOW WILL PERSIST THROUGH EARLY AFTERNOON THEN
CONDITIONS WILL GRADUALLY IMPROVE WITH MVFR CEILINGS PREVAILING.
AT KRST...SNOW IS FINISHED MINUS INTERMITTENT SNOW SHOWERS THIS
AFTERNOON.
BREAKS AND THINNING OF THE CLOUDS THIS AFTERNOON ALONG WITH THE
FRESH 5 TO 7 INCHES OF SNOW WILL LEAD TO A FILLING OF THE CLOUD
DECK. RADIATIONAL COOLING TONIGHT AND LOW-LEVEL MOISTURE PROFILES
SUGGESTS CONFIDENCE IS PRETTY HIGH THAT THIS WILL HAPPEN...BUT
WHETHER IT COMES IN AS IFR OR MVFR IS UNCERTAIN. MODEL GUIDANCE
VARIES CONSIDERABLY...AND FOR NOW HAVE TRENDED CEILINGS AND
VISIBILITIES BACK DOWN TO LOW-END MVFR BY MID EVENING. THIS WILL
NEED TO BE CLOSELY WATCHED AND THERE IS THE CHANCE FOR A PERIOD OF
IFR CONDITIONS BEGINNING LATE TONIGHT.
FOR SATURDAY THE AREA REMAINS UNDER CYCLONIC FLOW WITH FLURRIES OR
OCCASIONAL LIGHT SNOW POSSIBLE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
318 PM CST FRI FEB 22 2013
WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ017-
029.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1205 PM CST FRI FEB 22 2013
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM UPDATE...
BANDS OF LIGHT TO MODERATE SNOWFALL CONTINUE OVER THE FORECAST
AREA THIS MORNING. VISIBLITIES HAVE BEEN GENERALLY AROUND A MILE
TO A 1/2 MILE IN THE HEAVIER SNOWBANDS. OFFICIALLY 1.9 OF INCHES
OF SNOW SO FAR AT THE OFFICE AS OF 6 AM. VERY GENERALLY ABOUT 1
TO 3 INCHES SO FAR THIS MORNING OVER PARTS OF CENTRAL AND
EASTCENTRAL WISCONSIN. JUST STARTING TO GET ADDITIONAL SNOWFALL
REPORTS FROM OBSERVERS.
AM GETTING CONCERNED THAT MID-LEVEL DRYING MAY VERY WELL WORK ITS
WAY INTO THE SOUTHERN PORTION OF THE FORECAST AREA IN THE NEXT
COUPLE OF HOURS. EXTRAPOLATION OF BACK EDGE OF INITIAL PRIAMRY
SNOWBAND WOULD TAKE IT TO ABOUT AN OSHKOSH TO MARSHFIELD LINE BY
8AM...AND PERHAPS INTO THE GREEN BAY AREA BY 10 AM. THIS TREND IS
ALSO APPEARING IN THE LATEST HRRR SHORT TERM FORECAST. HRRR ALSO
CONTINUES TO INSIST THAT SOME SECONDARY WEAKER SNOWBAND
DEVELOPMENT WILL OCCUR JUST SOUTHWEST OF THE FORECAST AREA TOWARD
NOONTIME THAT IS PROJECTED TO SPREAD NORTHEAST BACK INTO THE
FORECAST AREA. GIVEN THAT THE STORM SYSTEM IS BEGINNING THE
PROCESS OF WEAKENING...SECONDARY DEVELOPMENT WILL NOT BE AS
ROBUST AS WITH A DEEPENING SYSTEM.
WILL LIKELY NEED TO MAKE SOME ADJUSTMENTS IN THE MORNING FORECAST
TO ACCOUNT FOR THESE TRENDS. OBVIOUSLY IF WE DO NOT GET ADDITIONAL
SNOWBAND DEVELOPMENT UPSTREAM IN THE NORTHEAST QUADRANT OF THE
APPROACHING UPPER-LOW THIS COULD CUT STORM SNOWFALL TOTALS.
FORECAST UPDATE WILL BE OUT HOPEFULLY BY 630 AM.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY.
EXPECT SOME LIGHT SNOW SHOWERS OR FLURRIES TO PERSIST ACROSS THE
NORTHERN PART OF THE FORECAST AREA ON SATURDAY NIGHT AS THE
CURRENT STORM SYSTEM CONTINUES TO MOVE AWAY FROM WISCONSIN. AFTER
THAT THERE WILL BE A PERIOD OF DRY WEATHER...THROUGH SUNDAY
NIGHT...WITH SURFACE HIGH PRESSURE AND AN UPPER LEVEL RIDGE OVER
THE STATE.
CONFIDENCE IS LOW REGARDING THE NEXT STORM SYSTEM EXPECTED TO
IMPACT THE AREA. THERE WERE SIGNIFICANT DIFFERENCES AMONG THE
MODELS IN THEIR HANDLING OF THE SYSTEM. THIS HAS RESULTED IN A
FORECAST OF CHANCE POPS MONDAY NIGHT THROUGH WEDNESDAY...FOR NOW.
HOPEFULLY MODELS WILL CONVERGE ON A SIMILAR SOLUTION WITHIN THE
NEXT COUPLE OF DAYS.
LOW TEMPERATURES ON SUNDAY NIGHT MAY NEED TO BE LOWERED DUE TO
FRESH SNOW AND LIGHT WINDS...BUT NOT SURE WHETHER CLOUDS WILL HANG
AROUND THE AREA SO DID NOT GO TOO COLD. OTHERWISE TEMPERATURES
SHOULD BE AT OR ABOVE NORMAL WITH MAINLY SOUTHWEST OR ZONAL UPPER
FLOW THE REST OF THE PERIOD.
&&
.AVIATION...SNOW AND MOSTLY IFR CONDITIONS ARE EXPECTED TO
CONTINUE THIS AFTERNOON AND TONIGHT. THE SNOW WILL DIMINISH TO
SNOW SHOWERS OR FLURRIES OVERNIGHT. MVFR CEILINGS AND SNOW SHOWERS
ARE EXPECTED SATURDAY.
RDM
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR WIZ005-
010>013-018>022-030-031-035>040-045-048>050-073-074.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
613 AM CST FRI FEB 22 2013
.SHORT TERM UPDATE...
BANDS OF LIGHT TO MODERATE SNOWFALL CONTINUE OVER THE FORECAST
AREA THIS MORNING. VISIBLITIES HAVE BEEN GENERALLY AROUND A MILE
TO A 1/2 MILE IN THE HEAVIER SNOWBANDS. OFFICIALLY 1.9 OF INCHES
OF SNOW SO FAR AT THE OFFICE AS OF 6 AM. VERY GENERALLY ABOUT 1
TO 3 INCHES SO FAR THIS MORNING OVER PARTS OF CENTRAL AND
EASTCENTRAL WISCONSIN. JUST STARTING TO GET ADDITIONAL SNOWFALL
REPORTS FROM OBSERVERS.
AM GETTING CONCERNED THAT MID-LEVEL DRYING MAY VERY WELL WORK ITS
WAY INTO THE SOUTHERN PORTION OF THE FORECAST AREA IN THE NEXT
COUPLE OF HOURS. EXTRAPOLATION OF BACK EDGE OF INITIAL PRIAMRY
SNOWBAND WOULD TAKE IT TO ABOUT AN OSHKOSH TO MARSHFIELD LINE BY
8AM...AND PERHAPS INTO THE GREEN BAY AREA BY 10 AM. THIS TREND IS
ALSO APPEARING IN THE LATEST HRRR SHORT TERM FORECAST. HRRR ALSO
CONTINUES TO INSIST THAT SOME SECONDARY WEAKER SNOWBAND
DEVELOPMENT WILL OCCUR JUST SOUTHWEST OF THE FORECAST AREA TOWARD
NOONTIME THAT IS PROJECTED TO SPREAD NORTHEAST BACK INTO THE
FORECAST AREA. GIVEN THAT THE STORM SYSTEM IS BEGINNING THE
PROCESS OF WEAKENING...SECONDARY DEVELOPMENT WILL NOT BE AS
ROBUST AS WITH A DEEPENING SYSTEM.
WILL LIKELY NEED TO MAKE SOME ADJUSTMENTS IN THE MORNING FORECAST
TO ACCOUNT FOR THESE TRENDS. OBVIOUSLY IF WE DO NOT GET ADDITIONAL
SNOWBAND DEVELOPMENT UPSTREAM IN THE NORTHEAST QUADRANT OF THE
APPROACHING UPPER-LOW THIS COULD CUT STORM SNOWFALL TOTALS.
FORECAST UPDATE WILL BE OUT HOPEFULLY BY 630 AM.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY.
EXPECT SOME LIGHT SNOW SHOWERS OR FLURRIES TO PERSIST ACROSS THE
NORTHERN PART OF THE FORECAST AREA ON SATURDAY NIGHT AS THE
CURRENT STORM SYSTEM CONTINUES TO MOVE AWAY FROM WISCONSIN. AFTER
THAT THERE WILL BE A PERIOD OF DRY WEATHER...THROUGH SUNDAY
NIGHT...WITH SURFACE HIGH PRESSURE AND AN UPPER LEVEL RIDGE OVER
THE STATE.
CONFIDENCE IS LOW REGARDING THE NEXT STORM SYSTEM EXPECTED TO
IMPACT THE AREA. THERE WERE SIGNIFICANT DIFFERENCES AMONG THE
MODELS IN THEIR HANDLING OF THE SYSTEM. THIS HAS RESULTED IN A
FORECAST OF CHANCE POPS MONDAY NIGHT THROUGH WEDNESDAY...FOR NOW.
HOPEFULLY MODELS WILL CONVERGE ON A SIMILAR SOLUTION WITHIN THE
NEXT COUPLE OF DAYS.
LOW TEMPERATURES ON SUNDAY NIGHT MAY NEED TO BE LOWERED DUE TO
FRESH SNOW AND LIGHT WINDS...BUT NOT SURE WHETHER CLOUDS WILL HANG
AROUND THE AREA SO DID NOT GO TOO COLD. OTHERWISE TEMPERATURES
SHOULD BE AT OR ABOVE NORMAL WITH MAINLY SOUTHWEST OR ZONAL UPPER
FLOW THE REST OF THE PERIOD.
&&
.AVIATION...LOOK FOR DETERIORATING CONDITIONS OVERNIGHT AS SNOW
MOVES INTO THE REGION. VISBYS EXPECTED TO DROP QUICKLY AS SNOW
MOVES IN...WITH IFR OR LIFR CONDITIONS EXPECTED THROUGH THE
MORNING HOURS. 3 TO 5 INCHES OF SNOW EXPECTED IN MOST PLACES WITH
GUSTY WINDS PRODUCING SOME BLOWING AND DRIFTING ESPECIALLY AT
SUE/MTW/GRB/ATW/OSH FRIDAY MORNING. LOOK FOR LONG DURATION/INTO
SAT/ OF LIGHT SNOW OR FLURRIES AS UPPER LEVEL LOW PRESSURE SYSTEM
LIFTS NORTH THROUGH STATE.
TE
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR WIZ005-
010>013-018>022-030-031-035>040-045-048>050-073-074.
&&
$$
ESB
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
345 AM CST FRI FEB 22 2013
.SHORT TERM...
AT THIS TIME NO SIGNIFICANT CHANGES IN SHORT TERM FORECAST AS
SYSTEM GENERALLY BEHAVING AS MODELS HAVE PROJECTED.
STRONG UPPER-LEVEL CIRCULATION CURRENTLY LOCATED OVER SOUTHWEST
IOWA IS CONSISTENT WITH 00Z MODEL FORECASTS. BANDS OF MODERATE
SNOW CONTINUE TO DEVELOP IN BROAD FGEN ZONE AND WAA OVER SOUTHERN
WISCONSIN AND ARE SPREADING QUICKLY NORTHWARD. LEADING EDGE OF MODERATE
SNOWFALL...AT 330 AM...EXTENDS FROM ABOUT KEWAUNEE TO GREEN
BAY...WESTWARD TO MOSINEE. VISIBLITIES ALONG HIGHWAY 29 SOUTHWARD
HAVE BEEN RANGING FROM 1 TO 1/2 MILE. HRRR FORECAST REFLECTIVITY
DATA CONSISTENT WITH CURRENT RADAR TRENDS. HRRR SHORT-TERM
FORECAST SUGGEST INITIAL MODERATE SNOWBAND WILL PUSH NORTH TO
ABOUT SUE-RHI BY 12Z...THEN WEAKEN SOMEWHAT BY TIME IT REACHES THE
WISCONSIN-MICHIGAN BORDER BY AROUND 14Z. LATEST MODEL GUIDANCE
ALSO A BIT COLDER AT 925/850MB COMPARED TO PREVIOUS RUNS...LENDING
MORE SUPPORT TO SOME LAKE ENHANCEMENT IN THE EAST. RADAR TRENDS
OVER LAKE MICHIGAN DO SEEM TO SUPPORT THIS. NOTE THAT BOUNDARY
LAYER WINDS NOT IDEAL WITH A BIT TOO MUCH DIRECTIONAL SHEAR AND
OVERWATER INSTABLITY WILL DECREASE DURING THE MORNING AS WAA
CONTINUES THUS LAKE CONTRIBUTION NOT EXPECTED TO BE SIGNIFICANT.
NEED TO WATCH THE PROGESS OF THE MID-LEVEL DRY INTRUSTION NOW
ENTERING SOUTHERN WISCONSIN. LATEST MODEL GUIDANCE DOES NOT
SUGGEST A CLEAN DRY SLOT WILL BE ABLE TO PUSH NORTHEAST INTO THE
SOUTHERN PORTION OF THE FORECAST AREA LATE THIS MORNING. IN FACT
THE HIGHER RESOLUTION WRF ARW/NMM AND HRRR SUGGEST THAT A COUPLE
SOMEWHAT WEAKER SNOWBANDS WILL LIKELY DEVELOP OVER SOUTHWEST
WISCONSIN LATER THIS MORNING AND ALSO PUSH INTO THE FORECAST AREA
INTO THE AFTERNOON. DAY-SHIFT WILL NEED TO MONITOR THIS EVOLUTION.
IF SOME MID-LEVEL DRYING IS ABLE TO PUNCH INTO THE SOUTHERN
PORTION OF THE FORECAST AREA...COULD SEE BRIEF PERIOD OF FREEZING
DRIZZLE LATER THIS MORNING. IF THIS DOES OCCUR...PROBABALY NOT A
HUGE IMPACT ON ROADS AS THEY WILL LIKELY BE SNOW-COVERED ANYWAY.
BOTTOM LINE IS THAT ADVISORY STILL LOOKS GOOD WITH 3 TO 5 INCH
AMOUNTS EXPECTED BY EARLY THIS EVENING. WITH WEAKENING UPPER
SYSTEM LINGERING INTO SATURDAY MORNING...COULD BE AN ADDITIONAL
INCH OR TWO...ESPECIALLY NORTH OF HIGHWAY 29...AND PERHAPS OVER
THE FAR NORTHEAST PORTION OF THE FORECAST AREA WHERE LINGERING
MODEST VERTICAL MOTION WILL PERSIST INTO THIS EVENING.
WINDS TO REMAIN STRONG FROM THE EAST THROUGH THE MORNING HOURS
AHEAD OF SURFACE LOW. 925 MB WINDS OF 25 TO 35 KNOTS EXPECTED
RESULT IN SURFACE WINDS OF 15 TO 25 MPH WITH HIGHER GUSTS
ESPECIALLY NEAR LAKE MICHIGAN. VISIBILITIES WILL BE LIMITED IN
SNOW AND BLOWING SNOW THIS MORNING. STILL EXPECT HIGHEST SNOWFALL
RATES TO OCCUR THROUGH ABOUT MID-DAY...THEN LOWER THEREAFTER.
EXPECT CONTINUED CYCLONIC FLOW ASSOCIATED WITH UPPER LOW FORECAST
TO DRIFT ACROSS THE FORECAST AREA...AND SUFFICIENTLY DEEP
MOISTURE TO REMAIN IN PLACE TO KEEP PERIODS OF LIGHT SNOW THROUGH
MUCH OF TONIGHT AND INTO SATURDAY. GFS HINTS THAT ADDITIONAL
SHORTWAVE ENERGY TO MOVE THROUGH ON BACKSIDE OF WEAKENING UPPER
LOW SATURDAY AFTERNOON...THOUGH OTHER MODELS NOT AS SUPPORTIVE IN
THAT REGARD. WILL GO WITH MORE SCATTERED WORDING FOR THAT DAY
PERIOD.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY.
EXPECT SOME LIGHT SNOW SHOWERS OR FLURRIES TO PERSIST ACROSS THE
NORTHERN PART OF THE FORECAST AREA ON SATURDAY NIGHT AS THE
CURRENT STORM SYSTEM CONTINUES TO MOVE AWAY FROM WISCONSIN. AFTER
THAT THERE WILL BE A PERIOD OF DRY WEATHER...THROUGH SUNDAY
NIGHT...WITH SURFACE HIGH PRESSURE AND AN UPPER LEVEL RIDGE OVER
THE STATE.
CONFIDENCE IS LOW REGARDING THE NEXT STORM SYSTEM EXPECTED TO
IMPACT THE AREA. THERE WERE SIGNIFICANT DIFFERENCES AMONG THE
MODELS IN THEIR HANDLING OF THE SYSTEM. THIS HAS RESULTED IN A
FORECAST OF CHANCE POPS MONDAY NIGHT THROUGH WEDNESDAY...FOR NOW.
HOPEFULLY MODELS WILL CONVERGE ON A SIMILAR SOLUTION WITHIN THE
NEXT COUPLE OF DAYS.
LOW TEMPERATURES ON SUNDAY NIGHT MAY NEED TO BE LOWERED DUE TO
FRESH SNOW AND LIGHT WINDS...BUT NOT SURE WHETHER CLOUDS WILL HANG
AROUND THE AREA SO DID NOT GO TOO COLD. OTHERWISE TEMPERATURES
SHOULD BE AT OR ABOVE NORMAL WITH MAINLY SOUTHWEST OR ZONAL UPPER
FLOW THE REST OF THE PERIOD.
&&
.AVIATION...LOOK FOR DETERIORATING CONDITIONS OVERNIGHT AS SNOW
MOVES INTO THE REGION. VISBYS EXPECTED TO DROP QUICKLY AS SNOW
MOVES IN...WITH IFR OR LIFR CONDITIONS EXPECTED THROUGH THE
MORNING HOURS. 3 TO 5 INCHES OF SNOW EXPECTED IN MOST PLACES WITH
GUSTY WINDS PRODUCING SOME BLOWING AND DRIFTING ESPECIALLY AT
SUE/MTW/GRB/ATW/OSH FRIDAY MORNING. LOOK FOR LONG DURATION/INTO
SAT/ OF LIGHT SNOW OR FLURRIES AS UPPER LEVEL LOW PRESSURE SYSTEM
LIFTS NORTH THROUGH STATE.
TE
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR
WIZ018>021-030-031-035>040-045-048>050-074.
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR WIZ005-
010>013-022-073.
&&
$$
ESB/MG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1123 PM CST THU FEB 21 2013
.SHORT TERM...
909 PM CST THU FEB 21 2013
SNOW WAS BREAKING OUT ACROSS NORTHEAST IOWA...WITH A DUSTING BEING
REPORTED IN THE EDGEWOOD AREA OF FAYETTE COUNTY. 22.00Z HRRR
CONTINUES TO PUSH THIS BAND OF SNOW NORTHEAST ACROSS THE FORECAST
AREA THROUGH THE REMAINDER OF THE EVENING...WITH AREAS NORTH
OF INTERSTATE 94 MOST LIKELY TO SEE THE SNOW BREAK OUT BETWEEN
06Z-09Z. 22.00Z NAM ALSO IN LINE WITH THIS TREND AS WELL. WILL BE
MAKING JUST SOME MINOR TWEAKS TO THE GRIDS BASED ON CURRENT TRENDS.
SOME CONCERN AS TO SNOW AMOUNTS ACROSS NORTHEAST IOWA THROUGH 06Z.
REPORTS BACK IN DMX AREA SHOWS GENERALLY 1 TO 3 INCHES HAVE
FALLEN. 22.00Z HRRR SHOWS THE LIGHTER SNOW AREAS TO FILL IN LATER
THIS EVENING AS IT LIFTS NORTHEAST. IF THIS OCCURS THEN WILL
REALIZE THE 2 TO 3 INCHES WE HAVE ACROSS FLOYD COUNTY. OTHERWISE
SNOW AMOUNTS THROUGH 06Z MAY BE A BIT HIGH. NONE THE LESS STILL
EXPECTING LOW END WARNING CRITERIA TO BE MET IN MUCH OF NORTHEAST
IOWA...WITH THE 4 TO 6 INCHES LIKELY ELSEWHERE.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
306 PM CST THU FEB 21 2013
21.12 MEDIUM RANGE MODELS ARE SHOWING SOME DIFFERENCES REGARDING THE
EVOLUTION OF THE TROUGH SUNDAY NIGHT THROUGH TUESDAY. THE GFS WRAPS
THE TROUGH INTO AN UPPER LOW OVER THE UPPER MIDWEST. THE ECMWF TAKES
THE TROUGH INTO THE CENTRAL AND SOUTHERN PLAINS AND DEEPENS INTO AN
UPPER LOW. THE GFS TAKES THE LOW EAST OVER SOUTHERN WISCONSIN ON
MONDAY WHILE THE ECMWF TAKES IT THROUGH THE OHIO RIVER VALLEY. THIS
SYSTEM HAS THE POTENTIAL TO BRING ACCUMULATING SNOW THE AREA BUT
THERE IS CONSIDERABLE UNCERTAINTY WITH THE STORM TRACK. HAVE LEANED
TOWARD A MODEL CONSENSUS BLEND SUNDAY NIGHT THROUGH TUESDAY. THE LOW
LOOKS TO MERGE WITH A SOUTHERN STREAM SYSTEM TUESDAY INTO WEDNESDAY
STALLING OVER THE EASTERN GREAT LAKES REGION. CYCLONIC FLOW IS
EXPECTED TO SET UP OVER THE FORECAST AREA ON THE WESTERN SIDE OF THE
LOW. EMBEDDED SHORTWAVES WILL BRING CHANCES FOR LIGHT SNOW TO THE
AREA WEDNESDAY INTO THURSDAY.
&&
.AVIATION...THROUGH 06Z SATURDAY
1123 PM CST THU FEB 21 2013
SNOW IS SPREADING INTO THE TAF SITES AND EXPECT CEILINGS AND
VISIBILITIES TO DROP RAPIDLY OVER THE NEXT HOUR INTO THE
IFR AND PERHAPS LIFR CATEGORY. EXPECT THESE CONDITIONS TO THEN
PERSIST THROUGH AT LEAST 14Z BEFORE A VERY GRADUAL INCREASE IN
VISIBILITIES ARE EXPECTED AS THE SNOW RATES BEGIN TO
DIMINISH...WITH VISIBILITIES STILL IN THE 1-2SM RANGE THROUGH 06Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
306 PM CST THU FEB 21 2013
WI...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
FRIDAY FOR WIZ041-053>055-061.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST FRIDAY
FOR WIZ017-029-032>034-042>044.
MN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
FRIDAY FOR MNZ079-086>088-094>096.
IA...WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM CST FRIDAY
FOR IAZ008>010-018-019-029-030.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
FRIDAY FOR IAZ011.
&&
$$
SHORT TERM...RABERDING
LONG TERM...WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
944 PM MST SAT FEB 23 2013
.UPDATE...
&&
.SHORT TERM...SNOW STARTING TO DEVELOP ALONG THE FRONT RANGE AS
LIFT MOVES IN AND PRESSURE FALLS MOVE INTO SOUTHERN COLORADO.
INTENSITY WILL BE LOW INITIALLY...PARTLY DUE TO DRY LOW LEVEL AIR
THAT WILL TAKE SEVERAL HOURS TO SATURATE. BUMPED UP THE TIMING OF
SNOW BEGINNING TO REFLECT WHAT IS HAPPENING...BUT NOT MUCH CHANGE
TO THE EXPECTED INTENSIFICATION LATER TONIGHT.
MODEL TRENDS CONTINUE TO BE A LITTLE STRONGER/SLOWER WITH A BIT
MORE SNOW...MAINLY DUE TO THE SNOW ENDING LATER. LATEST RUNS
SUGGEST ANOTHER INCH OR TWO IN THE DENVER AREA SUNDAY
EVENING...WITH SREF ENSEMBLES SUGGESTING 7-14 INCHES ACROSS DENVER
AND SEVERAL MEMBERS OVER 20 INCHES AT KAPA. THE SLOWER SPEED WOULD
ESPECIALLY IMPACT AREAS SOUTH OF DENVER WHERE THE SNOW RATES WOULD
STILL BE GOOD WITH THE UPSLOPE WIND. WE MAY NEED TO MOVE THE
FORECAST IN THAT DIRECTION...BUT WILL WAIT FOR MORE CONFIDENCE ON
THAT...LITTLE IMPACT ON THE CURRENT WARNINGS ANYWAY.
&&
.AVIATION...LITTLE CHANGE. SNOW BECOMING WIDESPREAD BY 08Z WITH
MVFR CONDITIONS PREVAILING...THEN LIFR CONDITIONS PREVAILING BY
12Z. 06Z TAFS WILL HAVE STRONGER WINDS SUNDAY
AFTERNOON...EXPECTING BLIZZARD CONDITIONS FOR SEVERAL HOURS AT
KDEN AND POSSIBLY KAPA...KBJC WILL LIKELY STAY LIFR BUT WILL
LIKELY HAVE LESS WIND AND VISIBILITY IMPACT. SOME SNOW
ACCUMULATION AND BLOWING/DRIFTING CONTINUING INTO SUNDAY EVENING
THEN MUCH BETTER BY 06Z MONDAY AT KBJC/KDEN AND 08Z AT KAPA.
&&
.PREV DISCUSSION... /ISSUED 330 PM MST SAT FEB 23 2013/
SHORT TERM....CURRENT WATER VAPOR AND Q-G ANALYSIS SHOWS A
STRONG STORM SYSTEM CARVING OUT ACROSS THE GREAT BASIN. LATEST
MODEL TRENDS FROM THE 12Z NAM...GFS...GEM AND EVEN WRF HAVE SHOWN
A SLIGHT NORTHWARD SHIFT IN AREAS OF BEST LIFT AND HEAVIER
SNOWFALL. HOWEVER...12Z ECMWF STILL MAINTAINED A PERSISTENT AND
PREFERRED SOLUTION BUT AT THE SAME TIME HAS INCREASED SNOWFALL
AMOUNTS AN INCH OR TWO MORE THAN THE 00Z RUN. NCEP FORECASTERS
WITH ACCESS TO 00Z EC ENSEMBLE MEMBERS NOTED THAT SOME UNCERTAINTY
EVEN REGARDED THE SLIGHTLY FARTHER SOUTH ECMWF SOLUTION...BUT Q-G
HEIGHT FALL ANALYSIS FROM THE RUC INDICATES THE OPERATION ECMWF
SEEMS QUITE REASONABLE. THE ONLY ARGUMENT WOULD BE IF A MID LEVEL
CIRCULATION CENTER PERHAPS RELATED TO LARGER LATENT HEAT RELEASE
WOULD RESULT IN A MORE NORTHERLY SOLUTION. AT THIS TIME...HAVE
STILL LEANED HEAVILY TOWARD THE ECMWF...BUT ALSO INCORPORATED A
BIT OF THE MESOSCALE/SREF MODEL SOLUTIONS.
ALL OF THESE FACTORS ADD UP TO A HIGH POTENTIAL FOR A HEAVY SNOW
EVENT. THEY INCLUDE...NEUTRAL STABILITY PROFILES...AVERAGE OF
25-30 KTS OF NNE UPSLOPE FLOW...DEEP UPSLOPE COMPONENT WELL ABOVE
MOUNTAIN TOP...GOOD MICROPHYSICS WITH LARGE OMEGA THROUGH THE
DENDRITIC GROWTH REGION...AND A 12-18 HOUR PERIOD OF MODERATE Q-G
VERTICAL MOTION. THIS ALL SUPPORTS THE UPGRADE OF BLIZZARD WATCHES
TO WARNING...WINTER STORM WATCHES TO WINTER STORM WARNINGS...AND
MOST OTHER LOCATIONS TO WINTER WEATHER ADVISORIES FOR SNOW AND
BLOWING SNOW. THE OVERALL BLENDING USING A MAJORITY OF THE ECMWF
WITH A LITTLE BIT OF MESOSCALE/SREF MODELS SUPPORT THE FOLLOWING
AMOUNTS...6-10 INCHES FOR DENVER/BOULDER AREA...8-12 INCHES PALMER
DIVIDE...7-14 INCHES FOOTHILLS...AND 4-8 INCHES THROUGH SOUTHERN
WELD...MORGAN...TOWARD WASHINGTON/LINCOLN COUNTY.
LONG TERM...THE BRUNT OF SUNDAY`S STORM SHOULD BE GETTING CLOSE
TO ENDING BY THE BEGINNING OF THE LONG TERM PERIOD 25/00Z. THERE
WILL PROBABLY STILL BE SOME SNOW OVER THE SOUTHEAST THIRD OR SO OF
THE CWA DURING THE EVENING BUT THAT WILL FLUSH OUT TOWARDS MORNING.
SURFACE PRESSURE GRADIENTS WILL REMAIN SUFFICIENT TO KEEP GUSTY
WINDS OVER MANY LOWER ELEVATIONS IN THE EVENING BUT THESE TOO WILL
SETTLE DOWN OVERNIGHT. ONLY A QUICK BREAK IN THINGS AS A SHORT
WAVE RIDGE MOVES IN FOR MONDAY WITH THE NEXT PACIFIC SYSTEM
IMPACTING OUR WEATHER ON TUESDAY. THIS WILL BE MAINLY A MOUNTAIN
EVENT BUT ENOUGH QG LIFT BLEEDS OVER THE HILLS TO BRING A THREAT
OF PRECIPITATION TO THE PLAINS TUESDAY. ANOTHER WEAKER SYSTEM IS
PROGGED TO PUSH OVER THE CENTRAL ROCKIES THURSDAY...AGAIN BEING
MAINLY A PRECIPITATION PRODUCER FOR THE HIGH COUNTRY. TEMPERATURES
WILL REMAIN BELOW NORMAL THROUGH MOST OF THE WEEK BUT SHOULD
APPROACH NORMAL TOWARD WEEK`S AS A STRONG RIDGE ALOFT BUILDS INTO
THE GREAT BASIN. THE MOUNTAINS AND FOOTHILLS WILL ALSO EXPERIENCE
SOME WINDY PERIODS AS THE FLOW ALOFT BECOMES NORTHWESTERLY.
AVIATION...SIGNIFICANT AVIATION IMPACTS EXPECTED FROM THIS
WINTER STORM. CEILINGS AND VISIBILITIES WILL TUMBLE TONIGHT AND
REMAIN VERY LOW THROUGH MOST OF SUNDAY. ONSET TIMING OF THIS IS
STILL RATHER DIFFICULT...BUT WE SHOULD SEE SNOW DEVELOPING IN THE
FRONT RANGE AIRPORTS MOST LIKELY BETWEEN 05Z AND 08Z...WITH VLIFR
CONDITIONS BY 09Z-11Z WHEN SNOWFALL RATES INCREASE TO AROUND 1
INCH PER. THE HEAVY SNOW WILL LIKELY CONTINUE THROUGH ABOUT 20Z
SUNDAY BEFORE CONDITIONS SLOWLY IMPROVE. GUSTS UP TO 30 KTS AT
KDEN WITH CONSIDERABLE BLOWING AND DRIFTING SNOW AND POOR
VISIBILITIES CLOSE TO ONE QUARTER MILE FOR SEVERAL HOURS DURING
THE HEAVIEST SNOW 11Z-20Z...THEN GRADUAL IMPROVEMENT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 AM TO 5 PM MST SUNDAY FOR COZ048-
050-051.
WINTER STORM WARNING UNTIL 5 PM MST SUNDAY FOR COZ035-036-039-
040.
WINTER WEATHER ADVISORY UNTIL 5 PM MST SUNDAY FOR COZ031-033-034.
WINTER WEATHER ADVISORY UNTIL 5 PM MST SUNDAY FOR COZ038-042.
WINTER STORM WARNING FROM 2 AM TO 5 PM MST SUNDAY FOR COZ043-044.
BLIZZARD WARNING FROM 2 AM TO 5 PM MST SUNDAY FOR COZ041-045.
BLIZZARD WARNING FROM 5 AM TO 5 PM MST SUNDAY FOR COZ046-047-049.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM....ET
AVIATION/UPDATE...GIMMESTAD
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
349 AM EST SUN FEB 24 2013
...DENSE FOG ADVISORY IN EFFECT THIS MORNING...
...FLOOD WATCH IN EFFECT FOR PORTIONS OF NORTH AND ALL OF CENTRAL
GEORGIA MONDAY THROUGH TUESDAY...
.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...
LATEST REGIONAL RAP ANALYSIS INDICATES FRONTAL BOUNDARY HAS MADE
ITS WAY THROUGH THE FORECAST AREA WITH NW FLOW AT THE SURFACE.
MOISTURE...ESPECIALLY AT THE EXTREME LOW LEVELS HAS BEEN MUCH
SLOWER TO DEPART RESULTING IN DENSE FOG ACROSS THE REGION. HAVE
BEEN TRACKING TWO SEPARATE AREAS OF DENSE FOG...BOTH OF WHICH ARE
TRANSIENT MAKING THE FORECAST CHALLENGING TO SAY THE LEAST AS FAR
AS VISIBILITY IS CONCERNED THROUGH DAYBREAK. HAVE OPTED TO GO WITH
A DENSE FOG ADVISORY FOR THE ENTIRE AREA AND AS CONDITIONS IMPROVE
THROUGH DAYBREAK...CANCEL COUNTIES OUT AS NECESSARY.
TODAY LOOKS TO BE A TRANSITION DAY ACROSS THE AREA...A MUCH NEEDED
BREAK FROM RECENT RAINFALL ACROSS THE SOUTHERN TIER ALTHOUGH
FLOODING WILL BE ONGOING. SOME 5 INCHES OF RAIN IN AREAS FROM
PREVIOUS SYSTEM AND HAVE AREAL FLOOD WARNING IN EFFECT FOR CRISP
COUNTY. WILL SEE FRONT FRONT SETTLE ACROSS NORTH FLORIDA WITH HIGH
PRESSURE BUILDING IN OVER THE OHIO VALLEY AND RIDGING THROUGH
TENNESSEE AND THE LOCAL FORECAST AREA. FLOW ALOFT LOOKS TO REMAIN
ZONAL TO SLIGHTLY RIDGING AND ONCE LOW CLOUDS CLEAR...WE SHOULD
SEE A STELLAR END TO THE WEEKEND WITH TEMPS IN THE 60S AND EVEN A
FEW LOW 70S TO THE SOUTH.
RESPITE FROM THE RAIN LOOKS QUITE SHORT LIVED AS POTENT SHORTWAVE
DIVES INTO THE SOUTHERN PLAINS CREATING A LARGE SCALE DIFFLUENT
FLOW ALOFT FOR THE SOUTHEAST. ADD TO THIS RIPPLES EMBEDDED IN THE
ZONAL FLOW AND SHOULD SEE AREA OF MODERATE RAIN DEVELOP ACROSS THE
SOUTHERN TIER BY MONDAY MORNING. WITH WEDGE STRENGTHENING OVER THE
CAROLINAS...ADIABATIC OMEGA BECOMES MAXIMIZED DURING THE DAY
MONDAY WITH NEAR CATEGORICAL POPS ANTICIPATED AREA WIDE. WILL
DISCUSS FLOOD IMPLICATIONS FURTHER IN HYDROLOGY SECTION.
BY MONDAY NIGHT...WARM FRONT WILL PUSH INTO THE SOUTHERN MOST
COUNTIES WITH LIMITED SURFACE INSTABILITY BUT INCREASED LOW LEVEL
HELICITY. APPEARS AT THIS POINT THAT SEVERE THREAT WILL BE
ISOLATED AT BEST BUT STILL HAVE A FEW ANALOGS WHICH POINT TO
POTENTIAL ISOLATED TORNADO DEVELOPMENT MONDAY NIGHT INTO TUESDAY
MORNING. SREF ADDS SOME VALIDITY TO THIS WITH PROBABILITY OF 50
PERCENT OF STP OF 1 OR GREATER TUESDAY MORNING.
DEESE
.LONG TERM /TUESDAY THROUGH SATURDAY/...
GFS AND ECMWF MODELS SIMILAR THROUGH THE EXTENDED FORECAST PERIOD
CONCERNING THE LARGE SCALE PATTERN. RAIN LIFTING OUT OF THE FORECAST
AREA THROUGH THE DAY TUESDAY AS THE MAIN UPPER LOW AND ASSOCIATED
SURFACE LOW LIFT INTO THE EASTERN OHIO VALLEY. UPPER PATTERN THROUGH
THE MAJORITY OF THE REMAINDER OF THE EXTENDED FORECAST PERIOD
DOMINATED BY MODERATE TO STRONG NORTHWESTERLY FLOW AS BROAD BUT DEEP
UPPER TROUGH LINGERS OVER THE EASTERN U.S. TIGHT SURFACE PRESSURE
GRADIENT PERSISTS AS WELL THROUGH THE PERIOD WITH MODERATE TO STRONG
NORTHWESTERLY FLOW PERSISTING. GFS KEEPS LOW QPF ALONG OUR FAR
NORTHERN COUNTIES WEDNESDAY THROUGH SATURDAY WHILE THE ECMWF KEEPS
THE ENTIRE FORECAST AREA DRY THROUGH ALL BUT THURSDAY. HAVE KEPT THE
PREVIOUS TREND OF SLIGHT CHANCE POPS AND VERY LOW QPF FOR THE FAR
NORTH WEDNESDAY THROUGH SATURDAY. MODEL THICKNESSES AND TEMPERATURES
WOULD INDICATE A CHANCE FOR MIXED PRECIPITATION THROUGH THE
PERIOD...ALTHOUGH WITH THE LOW CHANCES AND LIMITED MOISTURE AVAILABLE
ANY AMOUNTS WOULD LIKELY BE VERY SMALL. THIS TREND WILL NEED TO BE
WATCHED CLOSELY AS WE MOVE INTO THE MIDDLE OF THE WEEK. HOWEVER THIS
PATTERN DOES POINT TO A PERIOD OF BELOW NORMAL TEMPERATURES THROUGH
THE EXTENDED FORECAST PERIOD.
20
&&
.HYDROLOGY...QPE FROM PREVIOUS EVENT INDICATES 2 INCHES OF RAIN
FELL FROM ROUGHLY THE ATLANTA METRO TO AS MUCH AS 4 INCHES FOR THE
SOUTHERN TIER. SAME AREA IS TARGETED FOR THIS EVENT WITH AN
ADDITIONAL 2 TO 3 INCHES EXPECTED AND HAVE ISSUED A FLOOD WATCH
THROUGH TUESDAY EVENING.
&&
AVIATION...
06Z UPDATE...
CHALLENGING FORECAST IN STORE AS LOW LEVEL MOISTURE CLEARS BUT
RESIDUAL MOISTURE FROM RECENT RAINS REMAINS AT THE SURFACE. THIS
SHOULD RESULT IN LOW CLOUDS CLEARING BUT THE POTENTIAL FOR FOG
DEVELOPMENT. ATL STILL AT 5 TO 7 KTS WITH VSBY REMAINING MVFR TO
VFR BUT MUCH LESS VISIBILITY VALUES NOTED TO THE NORTH. FEEL WE
WILL GET REDUCTIONS AT ALL SITES FOR THE FIRST HALF OF THE
OVERNIGHT PERIOD...ESPECIALLY AT SOUTHERN SITES AND AHN BUT MAY
SEE PARTIAL IMPROVEMENT TOWARD DAYBREAK BUT CONFIDENCE IS LOW.
//ATL CONFIDENCE...06Z UPDATE...
LOW ON FOG DEVELOPMENT.
HIGH ON REMAINING ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 67 38 47 41 / 0 0 90 100
ATLANTA 63 43 47 41 / 0 20 100 100
BLAIRSVILLE 57 35 47 38 / 0 0 70 100
CARTERSVILLE 62 37 48 45 / 0 0 90 100
COLUMBUS 68 50 52 47 / 0 60 100 90
GAINESVILLE 64 38 49 38 / 0 0 90 100
MACON 70 44 51 48 / 0 40 100 80
ROME 62 35 49 47 / 0 0 90 100
PEACHTREE CITY 64 35 48 45 / 0 30 100 100
VIDALIA 72 49 58 55 / 20 40 100 60
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM MONDAY MORNING THROUGH TUESDAY EVENING FOR THE
FOLLOWING ZONES: BALDWIN...BANKS...BARROW...BIBB...BLECKLEY...
BUTTS...CARROLL...CHATTAHOOCHEE...CLARKE...CLAYTON...COBB...
COWETA...CRAWFORD...CRISP...DEKALB...DODGE...DOOLY...DOUGLAS...
EMANUEL...FAYETTE...FORSYTH...GLASCOCK...GREENE...GWINNETT...
HALL...HANCOCK...HARRIS...HEARD...HENRY...HOUSTON...JACKSON...
JASPER...JEFFERSON...JOHNSON...JONES...LAMAR...LAURENS...MACON...
MADISON...MARION...MERIWETHER...MONROE...MONTGOMERY...MORGAN...
MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...PEACH...
PIKE...PULASKI...PUTNAM...ROCKDALE...SCHLEY...SOUTH FULTON...
SPALDING...STEWART...SUMTER...TALBOT...TALIAFERRO...TAYLOR...
TELFAIR...TOOMBS...TREUTLEN...TROUP...TWIGGS...UPSON...WALTON...
WARREN...WASHINGTON...WEBSTER...WHEELER...WILCOX...WILKES...
WILKINSON.
DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR THE FOLLOWING
ZONES: BALDWIN...BANKS...BARROW...BARTOW...BIBB...BLECKLEY...
BUTTS...CARROLL...CATOOSA...CHATTAHOOCHEE...CHATTOOGA...
CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...CRISP...
DADE...DAWSON...DEKALB...DODGE...DOOLY...DOUGLAS...EMANUEL...
FANNIN...FAYETTE...FLOYD...FORSYTH...GILMER...GLASCOCK...
GORDON...GREENE...GWINNETT...HALL...HANCOCK...HARALSON...
HARRIS...HEARD...HENRY...HOUSTON...JACKSON...JASPER...
JEFFERSON...JOHNSON...JONES...LAMAR...LAURENS...LUMPKIN...
MACON...MADISON...MARION...MERIWETHER...MONROE...MONTGOMERY...
MORGAN...MURRAY...MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...
OGLETHORPE...PAULDING...PEACH...PICKENS...PIKE...POLK...
PULASKI...PUTNAM...ROCKDALE...SCHLEY...SOUTH FULTON...SPALDING...
STEWART...SUMTER...TALBOT...TALIAFERRO...TAYLOR...TELFAIR...
TOOMBS...TOWNS...TREUTLEN...TROUP...TWIGGS...UNION...UPSON...
WALKER...WALTON...WARREN...WASHINGTON...WEBSTER...WHEELER...
WHITE...WHITFIELD...WILCOX...WILKES...WILKINSON.
&&
$$
SHORT TERM...DEESE
LONG TERM....20
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
354 AM CST SUN FEB 24 2013
...UPDATED SYNOPSIS AND SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 352 AM CST SUN FEB 24 2013
THE 00Z UPPER AIR ANALYSIS SHOWED A MID/UPPER LEVEL TROUGH OVER THE
GREAT BASIN. THIS TROUGH CONTINUES TO DEEPEN AS IT MOVES SOUTHEAST
AND SHOULD CONTINUE TO DO SO GIVEN A 130 KNOT UPPER LEVEL JET ON THE
BACK SIDE OF THE UPPER TROUGH AND 130 METER HEIGHT FALLS TO ITS
SOUTHEAST. AT THE SURFACE, LOW PRESSURE WAS DEEPENING OVER NORTHEAST
NEW MEXICO. EAST OF THE LOW, UPPER 20S TO LOW 30S DEWPOINTS WERE
SPREADING NORTHWARD TOWARD THE CENTRAL HIGH PLAINS. AREAS OF FOG AND
LOW STRATUS WERE OCCURRING OVER WEST CENTRAL AND NORTHWEST KANSAS
EARLY THIS MORNING WITH SOME INDICATIONS OF DEVELOPMENT INTO
SOUTHWEST KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 352 AM CST SUN FEB 24 2013
VISIBILITIES ACROSS SOUTHWEST KANSAS HAVE BEEN STAYING MOSTLY IN THE
MVFR CATEGORY THROUGH THE EARLY MORNING HOURS WITH THE FAR NORTHERN
LOCATIONS AROUND HAYS SEEING VISIBILITIES OCCASIONALLY DROPPING TO A
QUARTER TO HALF MILE IN FOG. THE RUC13 AND HRRR ARE PICKING UP ON
THE FOG AND ARE SHOWING SOME SIGNIFICANT DEVELOPMENT TO THE SOUTH
ACROSS MUCH OF WEST CENTRAL AND SOUTHWEST KANSAS THROUGH THE NEXT
FEW HOURS THROUGH SUNRISE. THE 11-3.9U FOG CHANNEL HAS BEEN SHOWING
SOME HINTS OF FOG/STRATUS DEVELOPMENT AROUND COLDWATER/MEDICINE
LODGE AND GREENSBURG OVER THE PAST HOUR SO IT APPEARS THAT THERE IS
STILL POTENTIAL FOR THE FOG TO DEVELOP. HAVE LEFT THE DENSE FOG
ADVISORY IN PLACE THROUGH 9AM. IF NOTHING HAPPENS BY SUNRISE THEN
THE ADVISORY MAY BE ADJUSTED OR CANCELLED SOONER.
CONDITIONS ARE CONTINUING TO COME TOGETHER FOR A SIGNIFICANT WINTER
WEATHER EVENT ACROSS PARTS OF THE CENTRAL HIGH PLAINS STARTING THIS
EVENING AND CONTINUING THROUGH MONDAY EVENING. THE 00Z RUNS OF THE
NAM/GFS AND ECMWF ALL SHOW AN UPPER LOW CLOSING OFF OVER NEW MEXICO
BY THIS EVENING AND THEN INTENSIFYING AS IT TRACKS EAST INTO THE RED
RIVER VALLEY ON MONDAY. THE MODELS ARE ALL SHOWING PRECIPITATION
DEVELOPING ACROSS SOUTHWEST KANSAS LATE THIS AFTERNOON AND TONIGHT.
INITIAL PRECIPITATION COULD BE IN THE FORM OF FREEZING DRIZZLE OVER
FAR WESTERN KANSAS BUT THINK THIS WILL BE SHORT LIVED AS THE MID
LEVELS MOISTEN UP AND THE RESULTANT SEEDER/FEEDER MECHANISM CHANGES
PRECIPITATION OVER TO SNOW. FAR SOUTH CENTRAL KANSAS MAY SEE A
RAIN/SNOW MIX FOR A TIME TONIGHT AS TEMPERATURES IN THE LOWER LEVELS
HOVER AT OR SLIGHTLY ABOVE ZERO. AT ANY RATE, SNOW SHOULD BE
DEVELOPING OVER ALL OF SOUTHWEST AND CENTRAL KANSAS AS THE NIGHT
GOES ON AND BECOME HEAVY AT TIMES. SNOWFALL ACCUMULATIONS COULD BE
AS MUCH AS TWO TO FIVE INCHES BY MONDAY MORNING. WITH NORTH WINDS
EXPECTED TO INCREASE TO AROUND 25 TO 35 MPH, THERE WILL BE
CONSIDERABLE BLOWING AND DRIFTING SNOW WITH WIDESPREAD VISIBILITIES
AT A QUARTER MILE OR LESS EXPECTED. WITH THIS IN MIND, HAVE UPGRADED
THE BLIZZARD WATCH TO A BLIZZARD WARNING FOR ALL OF SOUTHWEST INTO
WEST CENTRAL AND SOUTH CENTRAL KANSAS TONIGHT.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 350 PM CST SAT FEB 23 2013
A SIGNIFICANT SHIFT WESTWARD IN THE DEVELOPMENT OF THE CYCLONE HAS
OCCURRED IN A NUMBER OF THE MODELS...ESPECIALLY THE GEM MODEL AND
THE HIGH RESOLUTION MODEL SUITE. CONFIDENCE HAS INCREASED ENOUGH TO
SUPPORT A BLIZZARD WATCH. THIS REPLACES THE WINTER STORM WATCH AS IT
NOW APPEARS THERE WILL BE A LONG-DURATION OF MODERATE TO HEAVY SNOW
AND NORTH WINDS 25-40 MPH. THIS WILL ALL UNFOLD LATE SUNDAY EVENING
AS THE INITIAL ROUND OF PRECIPITATION FORMS ACROSS THE TEXAS
PANHANDLE...AND LIFTS NORTHEASTWARD INTO SOUTHWEST KANSAS. THE
500MB LOW WILL DEEPEN FROM 542 DECAMETERS OVER EASTERN NEW MEXICO AT
06Z MONDAY TO 536 DECAMETERS NEAR WICHITA FALLS, TX AT 18Z MONDAY.
THIS ROBUST DEVELOPMENT WILL LEAD TO A TREMENDOUS DEVELOPMENT OF
COLD SECTOR PRECIPITATION AS MID LEVEL FLOW GAINS SOME EASTERLY
COMPONENT NORTH OF THE LOW. THIS WILL PULL ABUNDANT LOW LEVEL
MOISTURE INTO THE COLD SECTOR NORTH OF THE LOW. THE LATEST 15Z SREF
MEANS SHOW A DIRE SCENARIO OF WIDESPREAD 15 OR MORE INCHES OF SNOW
ACROSS MUCH OF KANSAS. THE ECMWF AND UKMET MODELS SHOW LESS STORM
TOTAL QPF ACROSS SOUTHWEST KANSAS AS IT IS NOT AS EXPANSIVE WITH THE
COMMA HEAD PRECIPITATION AS SOME OF THE HIGHER RESOLUTION MODELS ARE
SUGGESTING. MAKE NO MISTAKE, WHETHER WE RECEIVE 5 INCHES OR 15
INCHES OF SNOW, IMPACTS WILL BE SEVERE GIVEN A) ALREADY ESTABLISHED
SNOWPACK FROM EARLIER WEEK STORM LEADING TO IMMEDIATE
BLOWING/DRIFTING CONCERNS AND B) NORTH WINDS GUSTING OVER 50 MPH.
SHOULD THE SREF MEANS AND CANADIAN GEM MODEL COME TO FRUITION AND
MID LEVEL CYCLOGENESIS IS AS FAR WEST AND AS SIGNIFICANT AS THESE
MODELS SHOW...WE WILL HAVE A HISTORIC AND CRIPPLING EVENT TO DEAL
WITH ACROSS MUCH OF THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1151 PM CST SAT FEB 23 2013
WEAK UPSLOPE FLOW AND A MOIST BOUNDARY LAYER WILL AID IN THE
DEVELOPMENT OF FOG AND STRATUS LATER TONIGHT. THE LOW STRATUS AND
FOG WAS ALREADY DEVELOPING ALONG THE COLORADO BORDER AND IS EXPECTED
TO CONTINUE TO DEVELOP EASTWARD ACROSS SOUTHWEST INTO CENTRAL KANSAS
THROUGH THE PREDAWN HOURS. PREDOMINANTLY IFR CONDITIONS ARE EXPECTED
BY SUNRISE. VSBYS COULD IMPROVE TO MVFR DURING THE DAY ALONG WITH
SOME BREAKS IN THE LOW CLOUDS BUT ANY IMPROVEMENT WILL BE SHORT LIVED.
WINDS WILL SWITCH AROUND TO THE NORTH BY 00Z MONDAY AND SHOULD BE
INCREASING INTO THE 15 TO 25 KNOT RANGE DURING THE EVENING HOURS.
SOME LIGHT SNOW IS ALSO EXPECTED TO DEVELOP
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 32 24 32 18 / 40 90 90 60
GCK 32 22 33 13 / 40 80 80 30
EHA 32 18 33 16 / 40 80 80 30
LBL 33 21 33 14 / 30 90 90 30
HYS 30 24 31 21 / 40 80 80 60
P28 34 28 32 25 / 30 90 90 80
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST /8 AM MST/ THIS MORNING FOR
KSZ030-031-043>046-061>066-074>081-084>090.
BLIZZARD WARNING FROM 6 PM CST /5 PM MST/ THIS EVENING TO
MIDNIGHT CST /11 PM MST/ MONDAY NIGHT FOR KSZ030-031-043>046-
061>066-074>081-084>090.
&&
$$
SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...UMSCHEID
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
335 AM EST SUN FEB 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM EST SUN FEB 24 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED LO THAT HAS
BROUGHT SN/SHSN TO UPR MI THE LAST FEW DAYS MOVING SLOWLY TO THE E
AS UPR RDG AXIS EXTENDING FM HUDSON BAY INTO THE NRN PLAINS DRIFTS
SLOWLY TO THE E. COMBINATION OF LINGERING CYC NLY FLOW AND DEEP MSTR
SHOWN ON THE 00Z APX RAOB HAS ALLOWED SOME SHSN TO PERSIST OVER
MAINLY THE E HALF OF THE CWA UNDER POCKET OF H85/7 TEMPS AS LO AS
-11C/-17C...BUT THE CYC FLOW IS TENDING TO WEAKEN WITH SFC LO
SHIFTING TO THE E. IN FACT...THE WINDS AT STANNARD ROCK HAVE FALLEN
NEAR 5KTS EARLY THIS MRNG. 00Z RAOBS AT INL/YPL TO THE W/NW ALSO
SHOW A PRONOUNCED DRYING TREND ASSOCIATED WITH INCOMING RDG...WHICH
DROPPED THE INVRN BASE AS LO AS H9 AT YPL AT 00Z. 00Z H85 TEMPS
RANGE FM -11C AT GRB TO -6C AT INL AND -5C AT YPL. RECENT RADAR
TRENDS SHOW PERSISTENT HEAVIER SHSN THAT IMPACTED THE MQT AREA ARE
DIMINISHING WITH WEAKENING FLOW/SOME UPR DRYING UNDER DEEP LYR
QVECTOR DVGC/SUBSIDENCE LEFT IN THE WAKE OF SLOWLY DEPARTING CLOSED
LO. BUT SFC OBS/STLT IMAGERY SHOW LO CLDS LINGERING W INTO THE MN
ARROWHEAD. SKIES HAVE CLEARED OVER CNTRL MN UNDER SFC RDG AXIS.
FARTHER TO THE W...THERE IS A SHRTWV MOVING THRU SASKATCHEWAN.
PLENTY OF MID/HI CLDS ARE PRESENT TO THE E OF THIS DISTURBANCE...BUT
PCPN APPEARS LIMITED BY RATHER DRY LLVLS SHOWN ON THE 00Z BISMARCK
RAOB. ANOTHER MORE POTENT SHRTWV IS MOVING THRU THE SCENTRAL
ROCKIES. OTRW...THERE IS A LACK OF TRUE ARCTIC AIR OVER THE NRN
CONUS/SRN CANADA. IN FACT...THE 00Z H85 TEMP OF -11C AT GRB IS THE
LOWEST H85 TEMP IN CANADA S OF THE NW TERRITORIES AND NRN QUEBEC.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON CLD TRENDS/
IMPACT ON TEMPS.
TODAY...AS CLOSED LO SLIDES TO THE E...UPR RDG IS PROGGED TO BLD
OVER THE UPR LKS...RESULTING IN 12HR H5 HGT RISES UP TO 100M UNDER
INFLUENCE OF DEEP LYR QVECTOR DVGC/SUBSIDENCE. WITH SFC HI PRES RDG
AXIS FCST TO SHIFT INTO THE W HALF OF THE CWA BY 00Z MON...EXPECT
ANY LINGERING -SHSN TO END W-E. WITH LLVL NW FLOW PERSISTING THRU
THE DAY OVER THE E AHEAD OF INCOMING RDG AXIS...MIGHT EXPECT AT
LEAST SCT -SHSN TO PERSIST THERE. BUT FCST H85 TEMPS TO -8C TO -9C
IN THAT AREA /COMPARED TO LK WATER TEMPS 1 TO 2C/ BY 00Z AS WELL AS
DIFFLUENT NATURE OF THE INCRSG ACYC FLOW INDICATE THE ACTIVITY WL
END EVEN THERE IN THE AFTN. CLD TRENDS WL BE MORE DIFFICULT TO PIN
DOWN. AS THE SFC RDG AXIS ARRIVES...FCST SDNGS SHOWN INVRN BASE
SINKING TOWARD H9...WHICH MIGHT TRAP LINGERING LLVL MSTR AND RESULT
IN SC OVC. BUT WITH ACYC LLVL FLOW...SUSPECT SOME BREAKS IN THE CLDS
MAY DVLP OVER THE W NEAR THE WI BORDER LATER IN THE DAY...WHICH IS
CONSISTENT WITH THE CLRG OBSVD EARLY THIS MRNG CLOSER TO THE RDG
AXIS IN MN. AREAS OVER THE SCENTRAL FARTHER FM LK SUP INFLUENCE MAY
ALSO SEE SOME CLRG DESPITE RATHER WEAK WINDS/DOWNSLOPE IMPACT.
TNGT...THE SFC RDG AXIS IS PROGGED TO DRIFT SLOWLY TO THE E TNGT.
WITH WSHFT TO THE SW...EXPECT AT LEAST SOME BREAKS IN THE LINGERING
LO CLDS. WITH LGT WINDS...LOCATIONS THAT SEE SOME CLRG MIGHT SEE
TEMPS DROP SHARPLY. SO MAINTAINED FLAVOR OF GOING FCST SHOWING MIN
TEMPS DROPPING TOWARD THE LO END OF GUIDANCE. SOME HI CLDS AHEAD OF
SHRTWV MOVING ACRS SCENTRAL CANADA MAY MOVE INTO THE W LATE. SINCE
FOG HAS DVLPD UPSTREAM WHERE SKIES CLEARED IN MN...ADDED A MENTION
OF PATCHY FOG OVER THE INTERIOR AFTER MIDNGT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 323 AM EST SUN FEB 24 2013
MUCH OF THE WEATHER FOR THE LONG TERM WILL BE DOMINATED BY THE
CURRENT 500MB LOW/TROUGH CENTERED OVER UTAH AND WESTERN COLORADO.
LOOK FOR THE LOW TO DEEPEN AS IT ROUNDS NORTHERN TEXAS ON
MONDAY...WITH A DISTINCT/WRAPPED UP SFC LOW DEVELOPING.
EXPECT A PROLONGED PERIOD OF WINDS FROM THE NORTHEAST QUADRANT
/360-90 DEGREES/ FROM TUESDAY THROUGH AT LEAST SATURDAY. IF
TEMPERATURES WERE COLDER WE WOULD BE LOOKING AT AN EXTENDED PERIOD
OF MODERATE LAKE EFFECT SNOW SHOWERS ACROSS MUCH OF THE AREA...AND
PARTICULAR NORTH CENTRAL UPPER MICHIGAN. HOWEVER...SURFACE TEMPS
NEAR FREEZING AND 850MB TEMPS -3C TO -5C TUESDAY THROUGH WEDNESDAY
WILL ONLY SUPPORT SOME LAKE ENHANCEMENT TO THE SNOW ROTATING AROUND
THE BACK SIDE OF THE SURFACE LOW FROM TUESDAY NIGHT ON.
THE GFS REMAINS STRONGEST WITH THE N/NNE WINDS THROUGH MUCH OF THE
PERIOD...WITH WINDS NEAR OR ABOVE 30KTS FROM WEDNESDAY AFTERNOON
THROUGH FRIDAY ACROSS LAKE SUPERIOR. THE ECMWF RANGES FROM 3-9KTS
LIGHTER WITH THE WINDS...THANKS TO THE OVERALL WEAKER LOW EJECTING
FROM THE SOUTHERN PLAINS AND ACROSS ILLINOIS TUESDAY...AND OVER
LOWER MICHIGAN WEDNESDAY. THIS IS THE MAIN DIFFERENCE...WHETHER THE
LOW ENDS UP BEING 992MB /23/18Z GFS/ OR 1000MB /23/12Z ECMWF/ AS IT
CROSSES INTO SOUTHERN LOWER MI WEDNESDAY MORNING. EVEN THROUGH THE
TRACK OF THE SFC LOW MAY BE A BIT ON THE QUICK SIDE OFF OF THE
ECMWF...THE CONSENSUS IS TO HAVE A WEAKER SYSTEM THAN WHAT IS
INDICATED BY THE GFS. THE 00Z RUN OF THE GFS CAME IN SLIGHTLY WEAKER
AND FARTHER S OF ITS 18Z RUN TRACK /APPROX 250MI SSE OF THE 18Z RUN
LOW AT 12Z THURSDAY/...WHICH ALSO DIMINISHED WIND SPEEDS ON THE
ORDER OF 2-5KTS. THE SLIGHTLY EASTWARD 23/12Z AND 24/00Z ECMWF RUNS
FOR THE LOW TRACK DO NOT LOOK LIKE SUCH AN OUTLIERS ANYMORE.
ANOTHER EXTENDED SFC TROUGH WILL LINGER ACROSS OUR AREA THROUGH
FRIDAY NIGHT...DESPITE STRONG HIGH PRESSURE PUSHING IN FROM THE
WEST. COLD AIR WILL REMAIN TRAPPED OVER NORTHEASTERN CANADA...WITH
-12C 850MB TEMPS OVER ONTARIO...-8 TO -10C ACROSS UPPER MICHIGAN
THURSDAY AFTERNOON THROUGH SATURDAY. WITH DRY HIGH PRESSURE
FILTERING IN AT THE SFC AND ALOFT...EXPECT DIMINISHING LAKE ENHANCED
PRECIPITATION NEAR LAKE SUPERIOR WITH ONLY MINOR ACCUMULATIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1227 AM EST SUN FEB 24 2013
EXPECT LOW-END MVFR CEILINGS AT ALL SITES TO GRADUALLY IMPROVE TO
HIGHER-END MVFR CIGS BY SUNDAY AFTERNOON AS DEEPER MOISTURE DEPARTS
EAST WITH MOVEMENT OF LOW PRESSURE SYSTEM AND DRIER AIR FILTERS IN
FM WEST. ANY LINGERING LAKE ENHANCED SHSN AT KSAW SHOULD DISSIPATE
TO FLURRIES LATE TONIGHT AS DEEPER MOISTURE MOVES EAST AND LOW-LVL
CONVERGENCE WEAKENS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 323 AM EST SUN FEB 24 2013
THE TROUGH OF LOW PRESSURE OVER EASTERN LAKE SUPERIOR WILL SLOWLY
DISSIPATE TODAY AS HIGH PRESSURE BUILDS ACROSS THE UPPER GREAT LAKES
THROUGH MONDAY NIGHT. EXPECT LOW PRESSURE OVER THE SOUTHERN PLAINS
SUNDAY NIGHT TO TRACK NORTHEAST ACROSS THE MID MISSISSIPPI VALLEY ON
TUESDAY...BEFORE MOVING THROUGH THE LOWER GREAT LAKES WEDNESDAY INTO
WEDNESDAY NIGHT...WITH A PROLONGED PERIOD OF N-NE WINDS FROM TUESDAY
THROUGH SATURDAY. THE LOW WILL MOVE EASTWARD THROUGH THURSDAY WHILE
LEAVING YET ANOTHER TROUGH OVER LAKE SUPERIOR AS HIGH PRESSURE MOVES
EAST THROUGH MANITOBA. THE NORTH WINDS ARE EXPECTED TO INCREASE
SLIGHTLY FOR THURSDAY WITH A FEW GALE FORCE GUSTS POSSIBLE.
OTHERWISE...WINDS SHOULD REMAIN BELOW 30KTS THROUGH THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
355 AM CST SUN FEB 24 2013
.DISCUSSION...
MORE AND MORE...THE UPCOMING WEEK IS LOOKING DRY...AS MODELS
CONTINUE TO TREND THE BIG MIDWEEK WINTER STORM SOUTH AND EAST OF THE
MPX AREA. OTHERWISE...ONLY CONCERN TONIGHT AND AGAIN MONDAY NIGHT
WILL BE FOR REPEAT PERFORMANCES OF DENSE FOG.
OUT THE GATE THIS MORNING...MOIST BOUNDARY LAYER HAS COMBINED WITH
CLEAR SKIES AND LIGHT WINDS UNDER A SFC RIDGE ACROSS THE WRN HALF OF
MN TO GET SOME FAIRLY WIDESPREAD FOG GOING. PRETTY SOLID AREA OF 1/2
MILE OR LESS VIS FROM WEST CENTRAL UP THROUGH NW MN. FROM THE TWIN
CITIES ON EAST...STUBBORN CLOUD LAYER HAS KEPT FOG FROM FORMING. AS
FOR CURRENT ADVY...WILL TRIM COUNTIES UNDER THE INFLUENCE OF CLOUDS
OUT OF WHILE LEAVING THE REST IN PLACE...THOUGH MAY EXPAND IT ACROSS
THE REST OF SOUTH CENTRAL MN GIVEN DENSE FOG OBS AT FAIRMONT AND ST.
JAMES. BASED ON VIS FORECASTS FROM HRRR AND HOPWRF ENSEMBLE...NOT
EXPECTING ANY SIGNIFICANT IMPROVEMENTS UNTIL AFTER 15Z. IN
FACT...WHERE FOG IS MOST DENSE AROUND THE AXN AREA...MAY NOT BE
UNTIL CLOSER TO 18Z BEFORE SIGNIFICANT IMPROVEMENTS ARE MADE. THE
SLOW VIS RECOVERY IS SUPPORTED PHYSICALLY BY THE FACT THAT WE STILL
HAVE A SOMEWHAT SHALLOW LATE FEBRUARY SOLAR ANGLE AND VIRTUALLY NO
WIND IS EXPECTED WITHIN THE LOWEST 7K FT OF THE ATMO TODAY TO HELP
MIX THINGS OUT.
AS FOR FOG POTENTIAL AFTER TONIGHT...THE MPX AREA WILL REMAIN UNDER
A COL IN THE PRESSURE FIELD THROUGH MONDAY NIGHT...RESULTING IN WEAK
WINDS AND THEREFORE WEAK MECHANICAL MIXING. THE BIG QUESTION MARK
THE NEXT TWO NIGHTS WILL BE MID/UPPER LEVEL CLOUDS. TONIGHT LOOKS TO
OFFER A DECENT AMOUNT OF UPPER CLOUDS AS COMPLEX UPPER TROUGH
CURRENTLY OVER THE HIGH PLAINS MOVES OVERHEAD. SATELLITE IMAGERY
SHOWS PLENTY OF CLOUD COVER ASSOCIATED WITH THIS TROUGH AND AS THIS
PUSHES EAST DURING THE DAY...THIS SHOULD RESULT IN PLENTY OF
MID/UPPER CLOUDS TONIGHT. MONDAY NIGHT MAY FEATURE LESS CLOUD COVER
AS THE NRN STREAM WAVE SHEARS OUT. FORECAST SOUNDINGS BOTH NIGHTS
SHOW PLENTY OF LOW LEVEL MOISTURE BEING IN PLACE UNDER THE SFC RIDGE
TO SUPPORT FOG FORMATION...SO LONG AS THERE IS MINIMAL CLOUD COVER.
WITH UNCERTAINTIES IN CLOUD COVER BOTH NIGHTS...DID NOT MENTION ANY
FOG IN THE FORECAST...BUT THIS IS SOMETHING THAT WILL NEED TO BE
WATCHED CLOSELY.
WHEN IT COMES TO PRECIPITATION...NOW DOWN TO BASICALLY ONE
MODEL...THE GEM...THAT IS STILL BRINGING PRECIP TO THE AREA MID WEEK
IN ASSOCIATION WITH THE DEEP TROUGH NOW OVER THE 4-CORNERS. MODELS
ALL PRETTY SIMILAR WITH TAKING THIS UPPER LOW FROM NEW MEXICO TODAY
OVER TO THE LAKE ERIE REGION BY WEDNESDAY. THIS WILL BE QUITE THE
IMPRESSIVE SYSTEM...WITH H5 HEIGHT FALLS ON THE ORDER OF 200M AND A
WELL DEFINED H7 LOW. HEAVY SNOW SWATH STILL LOOKS LIKE A GOOD BET
FROM THE NE TX PANHANDLE UP INTO THE CHICAGO METRO AREA AND MID
MICHIGAN. FOR THE MPX AREA...WE WILL BE BATTLING RATHER STRONG DRY
AIR ADVECTION AND SUBSIDENCE ON THE NORTH SIDE OF THE SYSTEM. ONLY
REAL HOPE FOR PRECIP IN THE MPX AREA LOOKS TO COME TUESDAY NIGHT
INTO WEDNESDAY AS SFC LOW IS TRACKING FROM SRN IL TOWARD NRN OH. THE
QUESTION HERE IS HOW FAR NW DOES EXPANSIVE WRAP-AROUND PRECIP SHIELD
MAKE IT. AT THIS POINT...ONLY THE WRN OUTLIER GEM IS SHOWING PRECIP
ACROSS THE MPX CWA...WITH EVEN THE 24.03 SREF TRENDING SE WITH
PRECIP...KEEPING EVEN ERN AREAS WEST OF THE PRECIP. IF THIS TREND
CONTINUES...FUTURE SHIFTS COULD PROBABLY START PULLING OUT PRECIP
MENTION COMPLETELY. AS FOR WIND AND BLOWING SNOW POTENTIAL MID
WEEK...STILL EXPECT SPEEDS TO PICK UP TUESDAY THROUGH THURSDAY...BUT
WITH THE MAIN SFC LOW GOING AS FAR SOUTH AS IT IS...NOT EXPECTING
WINDS STRONG ENOUGH TO LEAD TO SIGNIFICANT ISSUES. LIKE TO SEE GUST
POTENTIAL OVER 30 MPH TO START SEEING SIGNIFICANT BLOWING SNOW
ISSUES...AND FORECAST SOUNDINGS FROM THE GFS KEEP EVERYTHING IN THE
20S.
FINALLY...WITH TEMPERATURES...NOT EXPECTING MUCH VARIATION OVER THE
NEXT WEEK AS 925-850 TEMPS LOOK TO STAY MORE OR LESS UNCHANGED. THIS
MEANS WE SHOULD CONTINUE TO SEE LOWER ALBEDO AREAS ACROSS CENTRAL
AND EAST CENTRAL MN INTO WRN WI WITH HIGHS MAINLY IN THE 30S...WHILE
HIGHER ALBEDO AREAS FROM WEST CENTRAL INTO SOUTH CENTRAL MN SEE HIGH
MAINLY SEE IN THE 20S. FOR LOWS...FOR THE NEXT COUPLE OF NIGHTS WITH
THE COL IN THE PRESSURE FIELD REMAINING OVERHEAD...THIS WILL LEAD TO
THE POTENTIAL FOR LOWS AROUND ZERO WHERE EVER A FEW HOURS OF
CLEARING CAN BE SEEN. OTHERWISE...LOWS WILL REMAIN ON THE MILD END
UNDER THE INFLUENCE OF CLOUDS...REMAINING UP IN THE TEENS AND 20S.
&&
.AVIATION.../06Z TAF ISSUANCE/
A BATCH OF VFR CIGS REMAINS ALONG AND EAST OF A LINE FROM RZN...TO
FCM...TO LVN AT TAF ISSUANCE TIME. LEVELS HAVE BEEN RUNNING BETWEEN 031
TO 040 IN THOSE AREAS. THE CLEARING LINE HAS SLOWED ITS
PROGRESSION EAST...SO EXPECTING THESE CIGS TO HANG IN FOR THE
OVERNIGHT. FURTHER WEST...FREEZING FOG IS BECOMING WIDESPREAD AND
LOCALLY DENSE WITH AXN EXPECTED TO REMAIN LIFR THROUGH MUCH OF THE
OVERNIGHT. A DETERIORATING VSBY TREND IS FORECAST AT STC AND RWF
DURING THE NEXT SEVERAL HOURS. HIGH CLOUDS OVER THE DAKOTAS WILL
SPREAD EAST EARLY SUNDAY MORNING WHICH COULD HELP IMPROVE
CONDITIONS A BIT NEAR SUNRISE. VFR CONDITIONS THEN RETURN BY
SUNDAY AFTERNOON.
KMSP...VFR CIGS OVERHEAD AT TAF ISSUANCE TIME...BUT CIGS HAVE BEEN
HOVERING NEAR THE VFR/MVFR CRITERIA THRESHOLD DURING THE LAST
SEVERAL HOURS. SHOULD SEE SOME DECREASE IN CLOUD COVER BY 09Z.
THEREAFTER...COULD SEE REDUCTIONS IN VSBY AND A REDEVELOPMENT OF
MVFR CIGS WITH THE LIGHT FOG/MIST. VFR CONDITIONS EXPECTED LATE
SUNDAY MORNING THROUGH THE EVENING WITH LIGHT WINDS.
/OUTLOOK FOR KMSP/
MON...MVFR WITH -SN POSSIBLE. WINDS ENE AT 5KTS.
TUE...MVFR WITH IFR AND -SN POSSIBLE WINDS N AT 10G15KTS.
WED...MVFR WITH -SN POSSIBLE. WINDS NNE AT 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FREEZING FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR BLUE EARTH-
BROWN-CARVER-CHIPPEWA-DOUGLAS-FARIBAULT-FREEBORN-KANDIYOHI-
LE SUEUR-MARTIN-MCLEOD-MEEKER-NICOLLET-POPE-RENVILLE-RICE-
SCOTT-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT-TODD-WASECA-
WATONWAN-WRIGHT.
WI...NONE.
&&
$$
MPG/BORGHOFF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
310 AM EST SUN FEB 24 2013
.SYNOPSIS...
WEAK LOW PRESSURE MOVES AWAY FROM THE CAROLINA COAST AS HIGH
PRESSURE BUILDS INTO THE AREA TODAY. ANOTHER STORM SYSTEM MOVES INTO
THE REGION BY TUESDAY. THE LOW PRESSURE SYSTEM WILL INFLUENCE THE
WEATHER OF THE REGION INTO LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM SUNDAY...
WHILE THE AXIS OF DEEPEST MOISTURE HAS FOR THE MOST PART SHIFTED
EAST AND DRIZZLE HAS BEEN MORE COMMON AROUND THE CWA ...A FEW
SHOWERS HAVE POPPED UP DURING THE PAST HOUR IN RESPONSE TO THE
APPROACHING UPPER TROUGH AXIS. THE HRRR HAS HAD A DECENT HANDLE ON
THIS EXPANDING PRECIP...AND WILL BE USED TO UPDATE THE NEAR TERM
FORECAST. WITH CONTINUED DRYING ALOFT COINCIDENT WITH THE TROUGH
PASSAGE...WILL BRING POPS TO AN END OVER THE NORTHERN COASTAL PLAIN
BY 12Z.
THE OTHER MAIN CONCERN IN THE NEAR TERM IS THE POTENTIAL FOR FOG.
THE BACK EDGE OF THE MAIN MID/HIGH CLOUD DECK HAS CLEARED THE
WESTERN PIEDMONT...BUT VISIBILITIES HAVE BEEN SLOW TO FALL BELOW 2SM
AT MOST SITES. A SECONDARY COLD FRONT IS WORKING ITS WAY ACROSS THE
MOUNTAINS...BUT AMPLE LOW LEVEL MOISTURE IN THE RESIDUAL WEDGE
AIRMASS WOULD SUPPORT DENSE FOG...MAINLY WEST OF RALEIGH. WE
WILL CONTINUE TO MONITOR THE OBSERVING SITES...BUT A DENSE FOG
ADVISORY MAY BE NEEDED BY 09-10Z.
LATER THIS MORNING..SKIES WILL CLEAR AND DRIER AIR WILL WORKS ITS
WAY ACROSS THE CWA. MODELS SHOW HE BETTER POST FRONTAL COLD
ADVECTION HOLDING OFF UNTIL AFTER 21Z...AND WITH FULL
INSOLATION...HIGHS SHOULD REBOUND RATHER NICELY. 1000-850MB
THICKNESSES REACHING THE 1330S THROUGH EARLY AFTERNOON SUPPORT HIGHS
IN THE UPPER 50S NORTH TO LOW/MID 60S SOUTH. HIGH PRESSURE WILL
BUILD INTO THE AREA TONIGHT...WITH THE RIDGE AXIS AND BEST POTENTIAL
FOR DECOUPLING ACROSS THE NORTHERN PIEDMONT/COASTAL PLAIN. LOWS
SHOULD FALL TO THE LOW TO MID 30S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
AS OF 305 AM SUNDAY...
MONDAY AND MONDAY NIGHT...
COLD HIGH PRESSURE WILL SETTLE OVER NEW ENGLAND ON MONDAY...RIDGING
SOUTH INTO THE CAROLINAS. A 15-20M DROP IN 1000-850MB THICKNESSES
FROM SUNDAY TO MONDAY SUGGESTS HIGHS WILL STRUGGLE TO CLIMB OUT OF
THE LOW TO MID 50S...EVEN WITH A FAIR AMOUNT OF SUN THROUGH MIDDAY.
HIGH CLOUDS WILL BEGIN TO POUR INTO THE AREA MONDAY AFTERNOON AHEAD
OF A LOW PRESSURE SYSTEM EJECTING OUT OF THE SOUTHERN PLAINS. WARM
ADVECTION AND ISENTROPIC LIFT WILL INCREASE RAPIDLY MONDAY NIGHT
AHEAD OF A STRONG LOW LEVEL JET AND SURFACE-850MB WARM FRONT
EMANATING OFF OF THE GULF COAST REGION. WHILE FORECAST SOUNDINGS
SHOW QUITE A BIT OF DRY AIR BELOW 10K FT...STRENGTHENING UPPER
DIVERGENCE AND A BACKED LOW-LEVEL ATLANTIC MOISTURE FEED ASSOCIATED
WITH AN APPROACHING UPPER JET SHOULD QUICKLY OVERWHELM THE
AIRMASS...LEADING TO POPS RANGING FROM CATEGORICAL IN THE SOUTHWEST
TO LIKELY IN THE NORTHEAST AFTER MIDNIGHT. LOWS IN THE MID 30S TO
LOWER 40S. -SMITH
TUESDAY AND TUESDAY NIGHT...
DIFFLUENCE ALOFT EXISTS IN EARNEST TUESDAY AS THE UPPER LOW LIFTS TO
THE NORTHWEST OF THE STATE. GOOD 850MB THETA-E ADVECTION IS IN
PLACE...AND BY 18Z TUESDAY...PRECIPITABLE WATER VALUES ARE CLOSING
IN ON 1.5 INCHES...NEAR THE MAXIMUM OF THE CLIMATOLOGICAL ENVELOPE
FOR LATE FEBRUARY IN CENTRAL NORTH CAROLINA. DEEP AND BROAD SURFACE
LOW PRESSURE IN CONJUNCTION WITH MOISTURE AND LIFT SUGGESTS
WIDESPREAD RAIN IN A WEDGED AIR MASS INTO TUESDAY AFTERNOON...AND
SOME OF THE RAIN COULD BE LOCALLY HEAVY WITH...CURRENTLY...THE
HEAVIEST RAIN MOST LIKELY FOCUSED ALONG AND EAST OF U.S. 1 WHERE
850MB THETA-E RIDGING IS GREATEST DURING THE DAY...AND WHERE 850MB
CONVERGENCE LINGERS LONGEST. BASIN AVERAGE RAINFALL FOR THIS
FORECAST WILL BE AROUND 0.75 INCH TOWARD THE TRIAD...AND AROUND 1.5
INCHES SOUTH OF A LINE FROM KMEB TO KGSB...INCLUDING KFAY.
WHILE THE NAM FORECASTS A SURFACE LOW FARTHER WEST IN CENTRAL NORTH
CAROLINA TOWARD 00Z WEDNESDAY...THE GFS FORECASTS THE TRIPLE POINT
OF LOW PRESSURE SKIRTING THE FAR SOUTHEAST OF CENTRAL NORTH
CAROLINA...MORE TOWARD KFAY...KCTZ...AND KGSB. BUFR SOUNDINGS FROM
BOTH THE NAM AND THE GFS SHOW THE WEDGE TO BE FAIRLY STRONG AND
PROBABLY DIFFICULT TO DISLODGE...AND INSTABILITY FOR NOW APPEARS TO
BE LIMITED IN CENTRAL NORTH CAROLINA FOR THIS EVENT. DURING TUESDAY
AFTERNOON...THE GFS FORECASTS MIXED LAYER CAPE APPROACHING 700J/KG
OVER PARTS OF EASTERN SOUTH CAROLINA WHICH DIMINISHES AS THE TRIPLE
POINT MOVES NORTHEAST INTO THE WEDGE...SKIRTING THE FAR SOUTHERN
COASTAL PLAIN WITH VALUES UNDER 500J/KG AND LIFTED INDICES JUST
BELOW ZERO. IT SHOULD BE A NARROW WINDOW FOR ANY POTENTIAL OF STRONG
THUNDER IN THE SOUTHEAST...NEEDING TO BE COINCIDENT WITH ENOUGH
WARMTH IN VICINITY OF THE TRIPLE POINT AS THE DRY SLOT MOVES IN. GFS
BUFR SOUNDINGS SHOW THE POTENTIAL FOR STRONGER STORMS IS GREATER
TOWARD THE COAST...WHERE THE 850MB AND 925MB WINDS...ALONG WITH
1000-500MB LAPSE RATES...WILL BE BETTER LATE IN THE DAY. CONSIDERING
A SLIGHT CHANCE OF THUNDER ONLY FOR THE FAR SOUTHEAST PART OF
CENTRAL NORTH CAROLINA AS OF THIS WRITING NEAR THE CURRENTLY
EXPECTED TRACK OF THE SURFACE LOW COINCIDENT WITH THE HIGHEST
AFTERNOON TEMPERATURES IN CENTRAL NORTH CAROLINA.
IN TERMS OF TEMPERATURES...THERE SHOULD BE A STRONG GRADIENT IN
HIGHS TUESDAY...STRUGGLING TO RISE THROUGH THE 40S IN THE TRIAD...
TO THE LOWER OR EVEN POSSIBLY THE MID 60S IN THE FAR SOUTHEAST. THE
MORNING BUFR SOUNDING TOWARD KGSO TUESDAY SHOWS A PORTION OF THE
TEMPERATURE PROFILE BELOW ZERO ALOFT...BUT PARTIAL THICKNESSES NOTE
THE PRECIPITATION TYPE SHOULD BE ALL LIQUID. THE DRY SLOT AND
DIMINISHING MOISTURE OVERALL PROVIDE FOR CHANCES FOR PRECIPITATION
LOWERING QUICKLY FROM LATE TUESDAY AFTERNOON THROUGH TUESDAY
EVENING...BUT THE NAM MAY BE ON TO SOMETHING WITH ITS BUFR SOUNDINGS
IN SHOWING LOW-LEVEL MOISTURE AND CLOUDS SLOW TO ERODE IN AREAS WEST
OF U.S. 1 AND PARTICULARLY TOWARD THE TRIAD. WILL TREND TOWARD
WARMER OVERNIGHT LOWS TUESDAY NIGHT...MOSTLY IN THE 40S. -DJF
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 305 AM SUNDAY...
DURING THE MIDDLE AND END OF THE WEEK...THE LONG-TERM GUIDANCE IS
FAIRLY CONSISTENT IN FORECASTING AN UPPER LOW OVER OR NEAR THE LOWER
GREAT LAKES...GRADUALLY MIGRATING EAST. CONSISTENCY IS ALSO APPARENT
IN THE GUIDANCE...WITH SUBTLE TIMING DIFFERENCES...IN FORECASTING AT
LEAST A MODERATE MID-LEVEL SHORTWAVE MOVING ACROSS THE STATE
SOMETIME WEDNESDAY INTO WEDNESDAY EVENING ACCOMPANIED BY A SURFACE
TROUGH OR SECONDARY COLD FRONT. FROM THERE...A BROAD UPPER TROUGH
REMAINS OVER CENTRAL NORTH CAROLINA THROUGH THE END OF THIS CURRENT
LONG-TERM PERIOD...WITH MAINLY NORTHWEST...CONFLUENT FLOW ALOFT
DEVELOPING THURSDAY...AND THE TROUGH AXIS BUILDING BACK SOUTHWEST
AND INTRODUCING SOUTHWEST FLOW ALOFT ACROSS CENTRAL NORTH CAROLINA
BY THE END OF THE WORK WEEK. MUCH OF THE MEASURABLE GUIDANCE QPF IS
AWAY FROM CENTRAL NORTH CAROLINA TO THE NORTHWEST AND NORTH...
CREEPING CLOSEST WITH THE APPROACH AND PASSAGE OF BOTH THE STRONGER
MID-LEVEL SHORTWAVE AND THE SURFACE TROUGH WEDNESDAY INTO WEDNESDAY
EVENING.
THE 00Z GFS BUFR SOUNDING FOR KGSO NEAR 00Z THURSDAY IS INTERESTING
IN ITS STEEP LAPSE RATES AND POTENTIAL INSTABILITY INTO THE ICE
NUCLEATION REGION...AND DESPITE THE STABILITY OF THE ECMWF COARSE
MODEL SOUNDINGS FOR KGSO AND ELSEWHERE IN CENTRAL NORTH CAROLINA...
THE STRENGTH OF THE MID-LEVEL WAVE AHEAD OF THE MID-LEVEL TROUGH AND
ITS HEIGHT FALLS...ACCOMPANIED BY THE SURFACE FEATURE...WOULD SEEM
TO WARRANT AT LEAST A SLIGHT CHANCE OF A SHOWER WEDNESDAY AFTERNOON
INTO WEDNESDAY EVENING NORTH OF U.S. 64 AND ESPECIALLY FROM
THE TRIAD TOWARD THE VIRGINIA BORDER RELATIVE TO THE REST OF THE
AREA. PARTIAL THICKNESSES ARE SUPPORTIVE OF ALL LIQUID AT THAT TIME.
THE SAME SOUNDINGS ALSO SHOW SOME MID-LEVEL MOISTURE PRESENT LATE
WEDNESDAY NIGHT INTO THURSDAY MORNING...AND AS THE TROUGH AXIS
ROTATES THROUGH...THERE COULD BE A FEW FLURRIES THEN WITH NO
ANTICIPATED IMPACT. FOR THIS FORECAST...WILL INTRODUCE A SLIGHT
CHANCE OF RAIN SHOWERS WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING
NORTH...WITH DRY CONDITIONS ELSEWHERE AND THEREAFTER FOR NOW.
WEDNESDAY AND THURSDAY SHOULD BE BREEZY DAYS IN A TIGHT SURFACE
GRADIENT BOTH AHEAD OF...AND ESPECIALLY BEHIND...THE SURFACE TROUGH
AND THICKNESS AND HEIGHT FALLS. FRIDAY SHOULD FEATURE SOMEWHAT
BREEZY CONDITIONS EARLY WITH MIXING BEFORE THE GRADIENT SLACKENS AS
LOW PRESSURE RETREATS OFFSHORE OF NEW ENGLAND AND THE MID-ATLANTIC.
THERE IS ALSO GOOD CONFIDENCE IN BELOW NORMAL HIGHS FOR THE END OF
THE WEEK INTO THE WEEKEND...LIKELY IN THE RANGE OF FIVE TO AROUND
TEN DEGREES BELOW WHAT SHOULD BE MID 50S TO AROUND 60. THE CONSENSUS
OF THE TEMPERATURE GUIDANCE...AND THE BLEND OF 1000-850MB
THICKNESSES BETWEEN THE GFS AND THE ECMWF...ARE BELOW MEX MOS
THURSDAY THROUGH SATURDAY. -DJF
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 1240 AM SUNDAY...
LOW CLOUDS AND LIMITED VSBYS CONTINUE ACROSS CENTRAL NC THIS MORNING
AS A MURKY WEDGE AIRMASS LINGERS EAST OF THE MOUNTAINS. DRYING OF
THIS AIRMASS IS EXPECTED OVER THE NEXT 6-10 HOURS...FIRST IN THE MID
LEVELS THROUGH 09Z...THEN AT LOW LEVELS BY 12-15Z. AS THE MID
LEVELS DRY AND MID/HIGH CLOUDS MOVE EAST...VSBYS SHOULD CONTINUE TO
DROP TO IFR AND/OR LIFR LEVELS...WITH A FEW HOURS OF DENSE FOG
POSSIBLE FROM MAINLY KRDU TO KGSO/KINT AND SURROUNDING SITES IN THE
WESTERN PIEDMONT. EAST OF KRDU...LIGHT RAIN AND CEILINGS IN THE
200-500 FT RANGE ARE MORE LIKELY. DRIER LOW LEVEL AIR IS EXPECTED
TO ARRIVE WITH A NORTHWESTERLY WIND AT KGSO/KINT BY 10-12Z...WITH
CEILINGS AND VSBYS IMPROVING TO VFR FROM WEST TO EAST QUICKLY AFTER
12Z.
VFR CONDITIONS WILL THEN PREVAIL THROUGH THE TAF PERIOD.
OUTLOOK...
VFR CONDITIONS WILL CONTINUE TONIGHT AND MONDAY. A STORM
SYSTEM MOVING INTO THE REGION MONDAY NIGHT WILL BRING SUB-VFR
CONDITIONS WITH THE POTENTIAL FOR ISOLATED THUNDERSTORMS (KFAY/KRWI)
AND HEAVY RAIN TUESDAY. VFR CONDITIONS ARE THEN EXPECTED TO RETURN
BY TUESDAY NIGHT AND PERSIST THROUGH THE END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...SMITH
SHORT TERM...SMITH/DJF
LONG TERM...SMITH
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
230 AM EST SUN FEB 24 2013
.SYNOPSIS...
WEAK LOW PRESSURE MOVES AWAY FROM THE CAROLINA COAST AS HIGH
PRESSURE BUILDS INTO THE AREA TODAY. ANOTHER STORM SYSTEM MOVES INTO
THE REGION BY TUESDAY. THE LOW PRESSURE SYSTEM WILL INFLUENCE THE
WEATHER OF THE REGION INTO LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM SUNDAY...
WHILE THE AXIS OF DEEPEST MOISTURE HAS FOR THE MOST PART SHIFTED
EAST AND DRIZZLE HAS BEEN MORE COMMON AROUND THE CWA ...A FEW
SHOWERS HAVE POPPED UP DURING THE PAST HOUR IN RESPONSE TO THE
APPROACHING UPPER TROUGH AXIS. THE HRRR HAS HAD A DECENT HANDLE ON
THIS EXPANDING PRECIP...AND WILL BE USED TO UPDATE THE NEAR TERM
FORECAST. WITH CONTINUED DRYING ALOFT COINCIDENT WITH THE TROUGH
PASSAGE...WILL BRING POPS TO AN END OVER THE NORTHERN COASTAL PLAIN
BY 12Z.
THE OTHER MAIN CONCERN IN THE NEAR TERM IS THE POTENTIAL FOR FOG.
THE BACK EDGE OF THE MAIN MID/HIGH CLOUD DECK HAS CLEARED THE
WESTERN PIEDMONT...BUT VISIBILITIES HAVE BEEN SLOW TO FALL BELOW 2SM
AT MOST SITES. A SECONDARY COLD FRONT IS WORKING ITS WAY ACROSS THE
MOUNTAINS...BUT AMPLE LOW LEVEL MOISTURE IN THE RESIDUAL WEDGE
AIRMASS WOULD SUPPORT DENSE FOG...MAINLY WEST OF RALEIGH. WE
WILL CONTINUE TO MONITOR THE OBSERVING SITES...BUT A DENSE FOG
ADVISORY MAY BE NEEDED BY 09-10Z.
LATER THIS MORNING..SKIES WILL CLEAR AND DRIER AIR WILL WORKS ITS
WAY ACROSS THE CWA. MODELS SHOW HE BETTER POST FRONTAL COLD
ADVECTION HOLDING OFF UNTIL AFTER 21Z...AND WITH FULL
INSOLATION...HIGHS SHOULD REBOUND RATHER NICELY. 1000-850MB
THICKNESSES REACHING THE 1330S THROUGH EARLY AFTERNOON SUPPORT HIGHS
IN THE UPPER 50S NORTH TO LOW/MID 60S SOUTH. HIGH PRESSURE WILL
BUILD INTO THE AREA TONIGHT...WITH THE RIDGE AXIS AND BEST POTENTIAL
FOR DECOUPLING ACROSS THE NORTHERN PIEDMONT/COASTAL PLAIN. LOWS
SHOULD FALL TO THE LOW TO MID 30S.
&&
.SHORT TERM /MONDAY/
AS OF 232 PM SATURDAY...
RIDGING WILL BE IN PLACE ALONG THE EASTERN SEABOARD SUNDAY NIGHT
INTO MIDDAY MONDAY. THE SURFACE HIGH PRESSURE IS FORECAST TO BE OF
SUFFICIENT STRENGTH AND OF A FAVORABLE LOCATION TO DELIVER DRY AND
CHILLY AIR INTO OUR REGION SUNDAY NIGHT AND MONDAY... ENOUGH TO
SUPPORT THE EVOLUTION OF ANOTHER CAD EVENT IN THE FOLLOWING PERIOD
(SEE DISCUSSION BELOW). DEW POINTS ARE FORECAST TO FALL INTO THE
TEENS NORTHEAST... RANGING INTO THE LOWER TO MID 20S SOUTH MONDAY.
EXPECT MOSTLY CLEAR SKIES SUNDAY NIGHT AND EARLY MONDAY... THEN
INCREASING CLOUDINESS MONDAY. A CHANCE OF RAIN LATE IN THE SW. LOWS
25-32. A COOLER NE FLOW SUGGEST HIGHS MONDAY WILL NOT BE MUCH WARMER
THAN 50-55.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS OF 232 PM SATURDAY...
...SIGNIFICANT RAIN AND POSSIBLY SOME FLOODING MONDAY NIGHT INTO
TUESDAY...
MODELS WERE STILL ADVERTISING QUITE A SPREAD IN LOCATION/STRENGTH OF
THE MAIN MID-UPPER LOW THAT IS FORECAST TO DEVELOP OVER THE SOUTHERN
PLAINS AND GENERALLY MOVE NE TOWARD THE LOWER OHIO VALLEY AND
EASTERN GREAT LAKES TUESDAY. THE EVENTUAL TRACK/STRENGTH OF THE
SYSTEM WILL HAVE RAMIFICATIONS IN OUR FORECAST OF RAINFALL TIMING
AND AMOUNTS FOR LATE MONDAY THROUGH TUESDAY. THE OVERALL PATTERN
SUPPORTS ANOTHER CAD EVENT EVENT WITH THE VERY DRY AND CHILLY DRY
AIR RIDGE ALONG THE EASTERN SEABOARD INITIALLY BEFORE THE RAIN
DEVELOPS.
THE PATTERN OF A DEEPENING AND CLOSING OFF OF A MID/UPPER LOW SHOULD
LEAD TO A SLOWER SOLUTION THAN THE FASTER MODELS SUGGEST (NAM). THE
LATEST OPERATIONAL EUROPEAN MODEL APPEARS TO FALL MUCH IN LINE WITH
THE AVERAGE SREF ENSEMBLE SOLUTIONS AND WILL BE PREFERRED. IT
APPEARS THAT THE DRY AIR RIDGE ALONG THE EASTERN SEABOARD WILL HOLD
ON INTO MONDAY AFTERNOON... WITH RAIN DEVELOPING FROM THE SOUTH
REACHING THE SOUTHERN PIEDMONT BY 00/TUESDAY. STRONG ISENTROPIC LIFT
OF WARM MOIST AIR FROM THE GULF AND WESTERN ATLANTIC SHOULD BE
TAPPED AND DRIVEN UP AND OVER A WARM/COASTAL SURFACE FRONT THAT WILL
BE SLOWLY ADVANCING N-NW TOWARD OUR SE COASTAL PLAIN BY LATE MONDAY
NIGHT AND EARLY TUESDAY. IF THE EC SOLUTION PROVES CORRECT... THE
SLOWER TIMING AND THE NEGATIVE TILT OF THE MID/UPPER TROUGH SHOULD
ALLOW FOR INCREASING HEAVY RAIN POTENTIAL LATE MONDAY NIGHT AND
TUESDAY. THE FORECAST OF A SECONDARY LOW PRESSURE ALONG THE
RETREATING WARM FRONT SHOULD ALSO FOCUS THE HEAVY RAIN OVER CENTRAL
AND EASTERN NC. EVEN THE LATEST EC MAY BE DEVELOPING THE IMPORTANT
WAVE OF LOW PRESSURE TOO FAR WEST INTO THE PIEDMONT OF NC (DEEP IN
THE EXPECTED CAD REGION). WE PREFER THE EVOLUTION OF THE LOW TO BE
ALONG THE CAD BOUNDARY CLOSER TO THE COAST. IF THIS IS CORRECT...
OUR REGION WILL NOT GET IN THE WARM SECTOR AND THE CHANCE OF SURFACE
BASED THUNDER WILL BE NEARLY NIL. HOWEVER... ELEVATED THUNDERSTORMS
MAY DEVELOP AS THE MID-LEVEL LAPSE RATES ARE SUGGESTING.
THIS WILL BE AN IMPORTANT STORM SYSTEM FOR OUR REGION ESPECIALLY IN
REGARDS TO POTENTIALLY FOR HEAVY RAIN AND POSSIBLY SOME FLOODING. WE
WILL CONTINUE TO HIGHLIGHT THIS POTENTIAL IN THE HAZARDOUS WEATHER
OUTLOOK. QPF APPEARS THAT IT WILL NEED TO BE BEEFED UP TO AN AVERAGE
OF 1.5 INCHES... WITH 1-2 INCHES LIKELY. TIMING APPEARS TO BE MONDAY
NIGHT INTO TUESDAY... ENDING DURING TUESDAY AFTERNOON. THE SEVERE
THREAT APPEARS NIL AT THIS TIME... UNLESS FUTURE FORECASTS ARE FOR
LESS CAD... AND MORE IN THE WAY OF AN INLAND PENETRATING CAD
BOUNDARY. WINTER WEATHER APPEARS NIL AS WELL... AS THE MID LEVELS
ARE EXPECTED TO WARM SIGNIFICANTLY MONDAY NIGHT AND TUESDAY OUT
AHEAD OF THE MID/UPPER LOW. HOWEVER... THE CAD WILL POSE A RISK OF
BRIEF FREEZING RAIN MONDAY NIGHT IF THE TEMPERATURES WET BULB TO
30-31 OR 32. HOWEVER... IT APPEARS THAT THE CURRENT WET BULB
PROJECTIONS WILL BE IN THE 33-35 RANGE AT A MINIMUM BY 12Z/TUESDAY
SUGGESTING ALL RAIN EVEN IN THE HEART OF THE COLD AIR DAMMING OVER
THE PIEDMONT.
AFTER THIS SYSTEM LIFTS OUT LATE TUESDAY... A MILDER AND DRY
WESTERLY FLOW WILL FOLLOW WEDNESDAY AS THE STRONG LOW LIFTS OVER THE
GREAT LAKES. STRONG COOLING WILL FINALLY OCCUR WED NIGHT AND
THURSDAY AS THE H5 TROUGH DIGS OVER OUR REGION FROM THE MIDWEST. A
COLD AND LIKELY DRY NW FLOW PATTERN IS THEN EXPECTED FOR THE BALANCE
OF THE WEEK.
SENSIBLE WEATHER INCLUDES...
RAIN MONDAY NIGHT AND TUESDAY... POSSIBLY 1-2 INCHES. LOWS IN THE
30S TO AROUND 40 SE. HIGHS 40S NW TO LOWER 60S EAST TUESDAY. MILDER
AND DRY WED. LOWS IN THE UPPER 30S AND 40S. HIGHS IN THE MID 50S TO
MID 60S EAST. COLDER AND MOST LIKELY DRY LATER IN THE WEEK. WATCH
ANY DISTURBANCES IN THE NW FLOW HOWEVER... LOWS IN THE 20S AND LOWER
30S. HIGHS IN THE MID 40S TO MID 50S NW TO SE.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 1240 AM SUNDAY...
LOW CLOUDS AND LIMITED VSBYS CONTINUE ACROSS CENTRAL NC THIS MORNING
AS A MURKY WEDGE AIRMASS LINGERS EAST OF THE MOUNTAINS. DRYING OF
THIS AIRMASS IS EXPECTED OVER THE NEXT 6-10 HOURS...FIRST IN THE MID
LEVELS THROUGH 09Z...THEN AT LOW LEVELS BY 12-15Z. AS THE MID
LEVELS DRY AND MID/HIGH CLOUDS MOVE EAST...VSBYS SHOULD CONTINUE TO
DROP TO IFR AND/OR LIFR LEVELS...WITH A FEW HOURS OF DENSE FOG
POSSIBLE FROM MAINLY KRDU TO KGSO/KINT AND SURROUNDING SITES IN THE
WESTERN PIEDMONT. EAST OF KRDU...LIGHT RAIN AND CEILINGS IN THE
200-500 FT RANGE ARE MORE LIKELY. DRIER LOW LEVEL AIR IS EXPECTED
TO ARRIVE WITH A NORTHWESTERLY WIND AT KGSO/KINT BY 10-12Z...WITH
CEILINGS AND VSBYS IMPROVING TO VFR FROM WEST TO EAST QUICKLY AFTER
12Z.
VFR CONDITIONS WILL THEN PREVAIL THROUGH THE TAF PERIOD.
OUTLOOK...
VFR CONDITIONS WILL CONTINUE TONIGHT AND MONDAY. A STORM
SYSTEM MOVING INTO THE REGION MONDAY NIGHT WILL BRING SUB-VFR
CONDITIONS WITH THE POTENTIAL FOR ISOLATED THUNDERSTORMS (KFAY/KRWI)
AND HEAVY RAIN TUESDAY. VFR CONDITIONS ARE THEN EXPECTED TO RETURN
BY TUESDAY NIGHT AND PERSIST THROUGH THE END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...SMITH
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
318 AM CST SUN FEB 24 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
318 AM CST SUN FEB 24 2013
THE MAIN FOCUS THROUGH THE EARLY PART OF NEXT WEEK IS WITH THE
NEXT STORM SYSTEM THAT WILL TRACK INTO THE REGION AND BRING THE
POSSIBILITY OF SOME SNOW ALONG WITH IT.
CURRENTLY...SKIES HAVE CLEARED THROUGH MUCH OF THE REGION WITH THE
MAIN EXCEPTION BEING ACROSS NORTHERN WISCONSIN WHERE AN INVERTED
SURFACE TROUGH LINGERS NEAR THE UPPER GREAT LAKES. A SURFACE RIDGE
AXIS RUNS FROM THE TRIPLE POINT OF NORTH/SOUTH DAKOTA AND
MINNESOTA DOWN INTO CENTRAL ILLINOIS AND IS WHERE TEMPERATURES
HAVE DROPPED ENOUGH TO PRODUCE SOME POCKETS OF SHALLOW GROUND FOG.
A FEW SITES IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA HAVE BRIEFLY
GONE DOWN TO A 1/2SM...BUT HAVE JUST AS QUICKLY IMPROVED DUE TO
THE SHALLOW NATURE OF THIS FOG. WITH THE 24.07Z RAP SHOWING THIS
RIDGE AXIS NOT MAKING IT EAST OF THE RIVER UNTIL MID MORNING...AM
NOT EXPECTING MUCH IN THE WAY OF WIDESPREAD FOG IN THIS REGION.
MAY HAVE TO TRIM BACK SOME OF THE FREEZING FOG ADVISORY OVER THE
NEXT FEW HOURS WITH THE CHOPPING BLOCK LIKELY BEING WITH ANY
COUNTIES ALONG AND EAST OF THE MISSISSIPPI RIVER. EVEN IN THE
AREAS WHERE THE FOG DOES OCCUR...IMPACTS ARE EXPECTED TO BE
MINIMAL WITH THE SHORT DURATION OF IT...IF IT EVEN OCCURS. WITH
THE RIDGE AXIS OVER THE REGION TODAY...EXPECT A DECENT DAY WITH
MAINLY SUNNY SKIES AND HIGHS RIGHT AROUND NORMAL.
THIS RIDGE AXIS WILL LINGER ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY INTO MONDAY BEFORE THE NEXT SYSTEM MOVES IN FROM THE
SOUTHWEST AND ESCORTS IT OFF TO THE NORTH BY TUESDAY. THE TREND
FOR THIS NEXT SYSTEM APPEARS TO STILL BE THE SAME WITH THE MORE
SOUTHERLY TRACK THAT KEEPS MUCH OF THE HEAVIER SNOW TO THE SOUTH
OF THE FORECAST AREA. THE 24.00Z NAM/GFS/ECMWF ARE ALL FAIRLY
CLOSE WITH THE TRACK AND TIMING OF THE LOW RUNNING FROM SOUTH
CENTRAL MISSOURI TUESDAY MORNING ON INTO CENTRAL INDIANA BY
TUESDAY EVENING. THE 24.00Z NAM SEEMS TO BE A LITTLE UNDERDONE ON
ITS QPF AS BUFKIT SOUNDINGS OUT OF DBQ SHOW A FULLY SATURATED
SOUNDING FROM LATE TUESDAY AFTERNOON INTO THE OVERNIGHT HOURS BUT
QPF IS 0.00 THERE. HOWEVER...JUST TO THE NORTHWEST OF THAT AREA AT
ALO AND BLR...THESE SAME SOUNDINGS SHOW A SUBSTANTIAL DRY LAYER
THAT WILL NEED TO BE OVERCOME FROM THE SURFACE ON UP TO 700MB. DUE
TO THIS DRY LAYER...AM CONCERNED THAT THE SNOW FROM THIS SYSTEM
MAY NOT MAKE IT VERY FAR TO THE NORTHWEST OF THE MAIN BAND THAT IS
EXPECTED TO BE IN EASTERN IOWA/NORTHERN ILLINOIS. HAVE KEPT THE
CHANCES FOR SNOW GOING FOR THE TIME BEING...BUT THEY MAY HAVE TO
GET TRIMMED BACK IF THE 24.00Z NAM/ECMWF SOUTHEAST TREND HOLDS
FIRM.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
318 AM CST SUN FEB 24 2013
CONFIDENCE IS SOMEWHAT LOW WITH HOW LONG THE LIGHT SNOW MAY HOLD
ON ACROSS THE REGION AS THE TAIL END OF THE SYSTEM MOVES THROUGH.
THERE ARE DIFFERING OPINIONS ON WHERE THE INVERTED SURFACE TROUGH
SETS UP WITH THE 24.00Z ECMWF KEEPING THE AREA DRY THROUGH THE
REST OF THE WEEK WHILE THE 24.00Z GFS/GEM KEEPS SOME LIGHT SNOW IN
THROUGH THURSDAY. KEPT SOME SMALL CHANCES IN THERE FOR NOW INTO
EARLY THURSDAY MORNING...BUT AS MENTIONED FOR TUESDAY...CONFIDENCE
IN HOW FAR NORTHWEST THE SNOW MAKES IT IS PRETTY LOW AT THIS
POINT. DESPITE NORTHERLY FLOW ALOFT AND AT THE SURFACE...THERE IS
NOT MUCH OF A COLD SOURCE OF AN AIR MASS ACROSS CANADA TO PULL ANY
COLD AIR DOWN FROM...SO TEMPERATURES WILL REMAIN AT OR JUST BELOW
NORMAL THROUGH MUCH OF THE NEXT WEEK.
&&
.AVIATION...THROUGH 06Z MONDAY
1139 PM CST SAT FEB 23 2013
BOTH THE NAM AND RAP SHOW THAT THE CLEARING WILL NOT GET INTO KLSE
UNTIL AFTER 23.10Z. IN ADDITION...THE RAP STILL SHOWS 10 TO 15
KNOTS BELOW 1K FEET. AS A RESULT...FEEL THAT THE ODDS OF FREEZING
FOG IS MINUTE. MAIN FORECAST ADJUST WAS TO DELAY THE 2SM BR
ANOTHER 2 HOURS AND START IT AT 24.11Z.
LIKE EARLIER IN THE EVENING...THE BEST CHANCE FOR DENSE FREEZING FOG
WILL BE ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA. KRST WILL
LIKELY DEVELOP DENSE FOG AROUND 24.09Z. THIS FOG WILL THEN DISSIPATE
IN THE 14-16Z TIME FRAME WITH CONDITIONS GRADUALLY IMPROVING TO
MVFR BY MID SUNDAY MORNING AND EVENTUALLY OF VFR BY THE LATE
MORNING HOURS. AS THIS OCCURS..A LAYER OF 10-15K FEET CLOUDS
WILL MOVE INTO THE AREA AND PERSIST INTO SUNDAY EVENING
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
318 AM CST SUN FEB 24 2013
WI...FREEZING FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ032>034-
041-042-053>055-061.
MN...FREEZING FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ079-
086>088-094>096.
IA...FREEZING FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR IAZ008>011-
018-019-029-030.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CST SAT FEB 23 2013
.SHORT TERM...OVERNIGHT
959 PM CST SAT FEB 23 2013
THE CLEARING LINE STOPPED ITS EASTWARD PROGRESS ACROSS SOUTHEAST
MINNESOTA AND NORTHEAST IOWA AROUND 6 PM. BOTH THE RAP AND NAM ARE
IN GOOD AGREEMENT THAT THE CLEARING WILL NOT TAKE PLACE UNTIL THE
SURFACE RIDGE AXIS SLIDES THROUGH THE AREA. THIS WILL NOT OCCUR
UNTIL AFTER 3 AM FOR THE COUNTIES ALONG THE MISSISSIPPI RIVER AND
FOR CENTRAL WISCONSIN UNTIL AFTER 6 AM. IN ADDITION...IF SKIES DID
CLEAR...RAP SOUNDINGS SHOW 10 TO 15 KNOT WINDS IN THE LOWEST 1K
FEET UNTIL 24.11Z. THIS WOULD ONLY LEAVE A COUPLE OF HOURS FOR THE
FREEZING FOG TO FORM. AS A RESULT...NOT OVERLY CONFIDENT THAT THE
WESTERN WISCONSIN WILL SEE ANY FREEZING FOG.
IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA...THERE ARE AREAS OF FOG
ALREADY...THUS THINKING THESE AREAS HAVE A MUCH BETTER CHANCE OF
SEEING THE FREEZING FOG.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
255 PM CST SAT FEB 23 2013
THE LONG TERM FORECAST OVERALL IS FAIRLY QUIET. IN THE UPPER LEVEL
PATTERN...THE ECMWF/GFS/CANADIAN CONTINUE TO FORECAST THAT THE
WEAKENING STORM SYSTEM FROM TUESDAY IS GOING TO GET BOTTLED UP OVER
THE GREAT LAKES REGION...ONLY SLOWLY MOVING TO THE EAST. THERE ARE
TWO REASONS FOR THIS...1. THE SYSTEM IS HAVING TO GET THAT THROUGH
THE RIDGING AHEAD OF IT AND 2. THERE IS ANOTHER FAIRLY POTENT
SHORTWAVE TROUGH ON ITS HEELS COMING ACROSS THE SOUTHERN U.S. THAT
EVENTUALLY GETS ABSORBED. WHAT THIS MEANS FOR OUR AREA IS THAT WE
COULD SEE A GOOD 24 HOURS OR SO OF LIGHT SNOW FROM TUESDAY NIGHT
INTO WEDNESDAY...ASSOCIATED WITH MOISTURE WRAPPING AROUND THE UPPER
LOW. RAISED PRECIPITATION CHANCES SLIGHTLY...BUT FURTHER INCREASES
ARE LIKELY NEEDED. ONCE THE UPPER LOW SHIFTS EAST...THEN HIGH
PRESSURE BUILDS IN FROM THE U.S. AND CANADIAN PLAINS. HOWEVER...THE
HIGH PRESSURE AREA DOES NOT LOOK TO BUILD INTO THE AREA UNTIL
SATURDAY AT THE EARLIEST. A COMBINATION OF UPPER RIDGING BUILDING
OVER THE WESTERN U.S. AND TROUGHING HOLDING IN PLACE OVER THE
EASTERN U.S. LOOKS TO RESULT IN THIS SETUP. THEREFORE...A PROLONGED
PERIOD OF DRY...NORTHERLY FLOW IS EXPECTED. DESPITE THE NORTHERLY
FLOW...THE 850MB TEMPS BOTTOM OUT MAYBE AROUND -10C...THUS
TEMPERATURES SHOULD HANG JUST BELOW NORMAL.
&&
.AVIATION...THROUGH 06Z MONDAY
1139 PM CST SAT FEB 23 2013
BOTH THE NAM AND RAP SHOW THAT THE CLEARING WILL NOT GET INTO KLSE
UNTIL AFTER 23.10Z. IN ADDITION...THE RAP STILL SHOWS 10 TO 15
KNOTS BELOW 1K FEET. AS A RESULT...FEEL THAT THE ODDS OF FREEZING
FOG IS MINUTE. MAIN FORECAST ADJUST WAS TO DELAY THE 2SM BR
ANOTHER 2 HOURS AND START IT AT 24.11Z.
LIKE EARLIER IN THE EVENING...THE BEST CHANCE FOR DENSE FREEZING FOG
WILL BE ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA. KRST WILL
LIKELY DEVELOP DENSE FOG AROUND 24.09Z. THIS FOG WILL THEN DISSIPATE
IN THE 14-16Z TIME FRAME WITH CONDITIONS GRADUALLY IMPROVING TO
MVFR BY MID SUNDAY MORNING AND EVENTUALLY OF VFR BY THE LATE
MORNING HOURS. AS THIS OCCURS..A LAYER OF 10-15K FEET CLOUDS
WILL MOVE INTO THE AREA AND PERSIST INTO SUNDAY EVENING
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
255 PM CST SAT FEB 23 2013
WI...FREEZING FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST SUNDAY
FOR WIZ032>034-041-042-053>055-061.
MN...FREEZING FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST SUNDAY
FOR MNZ079-086>088-094>096.
IA...FREEZING FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST SUNDAY
FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...BOYNE
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
646 AM EST SUN FEB 24 2013
.PREV DISCUSSION... /ISSUED 349 AM EST SUN FEB 24 2013/
..DENSE FOG ADVISORY IN EFFECT THIS MORNING...
..FLOOD WATCH IN EFFECT FOR PORTIONS OF NORTH AND ALL OF CENTRAL
GEORGIA MONDAY THROUGH TUESDAY...
SHORT TERM /TODAY THROUGH MONDAY NIGHT/...
LATEST REGIONAL RAP ANALYSIS INDICATES FRONTAL BOUNDARY HAS MADE
ITS WAY THROUGH THE FORECAST AREA WITH NW FLOW AT THE SURFACE.
MOISTURE...ESPECIALLY AT THE EXTREME LOW LEVELS HAS BEEN MUCH
SLOWER TO DEPART RESULTING IN DENSE FOG ACROSS THE REGION. HAVE
BEEN TRACKING TWO SEPARATE AREAS OF DENSE FOG...BOTH OF WHICH ARE
TRANSIENT MAKING THE FORECAST CHALLENGING TO SAY THE LEAST AS FAR
AS VISIBILITY IS CONCERNED THROUGH DAYBREAK. HAVE OPTED TO GO WITH
A DENSE FOG ADVISORY FOR THE ENTIRE AREA AND AS CONDITIONS IMPROVE
THROUGH DAYBREAK...CANCEL COUNTIES OUT AS NECESSARY.
TODAY LOOKS TO BE A TRANSITION DAY ACROSS THE AREA...A MUCH NEEDED
BREAK FROM RECENT RAINFALL ACROSS THE SOUTHERN TIER ALTHOUGH
FLOODING WILL BE ONGOING. SOME 5 INCHES OF RAIN IN AREAS FROM
PREVIOUS SYSTEM AND HAVE AREAL FLOOD WARNING IN EFFECT FOR CRISP
COUNTY. WILL SEE FRONT FRONT SETTLE ACROSS NORTH FLORIDA WITH HIGH
PRESSURE BUILDING IN OVER THE OHIO VALLEY AND RIDGING THROUGH
TENNESSEE AND THE LOCAL FORECAST AREA. FLOW ALOFT LOOKS TO REMAIN
ZONAL TO SLIGHTLY RIDGING AND ONCE LOW CLOUDS CLEAR...WE SHOULD
SEE A STELLAR END TO THE WEEKEND WITH TEMPS IN THE 60S AND EVEN A
FEW LOW 70S TO THE SOUTH.
RESPITE FROM THE RAIN LOOKS QUITE SHORT LIVED AS POTENT SHORTWAVE
DIVES INTO THE SOUTHERN PLAINS CREATING A LARGE SCALE DIFFLUENT
FLOW ALOFT FOR THE SOUTHEAST. ADD TO THIS RIPPLES EMBEDDED IN THE
ZONAL FLOW AND SHOULD SEE AREA OF MODERATE RAIN DEVELOP ACROSS THE
SOUTHERN TIER BY MONDAY MORNING. WITH WEDGE STRENGTHENING OVER THE
CAROLINAS...ADIABATIC OMEGA BECOMES MAXIMIZED DURING THE DAY
MONDAY WITH NEAR CATEGORICAL POPS ANTICIPATED AREA WIDE. WILL
DISCUSS FLOOD IMPLICATIONS FURTHER IN HYDROLOGY SECTION.
BY MONDAY NIGHT...WARM FRONT WILL PUSH INTO THE SOUTHERN MOST
COUNTIES WITH LIMITED SURFACE INSTABILITY BUT INCREASED LOW LEVEL
HELICITY. APPEARS AT THIS POINT THAT SEVERE THREAT WILL BE
ISOLATED AT BEST BUT STILL HAVE A FEW ANALOGS WHICH POINT TO
POTENTIAL ISOLATED TORNADO DEVELOPMENT MONDAY NIGHT INTO TUESDAY
MORNING. SREF ADDS SOME VALIDITY TO THIS WITH PROBABILITY OF 50
PERCENT OF STP OF 1 OR GREATER TUESDAY MORNING.
DEESE
LONG TERM /TUESDAY THROUGH SATURDAY/...
GFS AND ECMWF MODELS SIMILAR THROUGH THE EXTENDED FORECAST PERIOD
CONCERNING THE LARGE SCALE PATTERN. RAIN LIFTING OUT OF THE FORECAST
AREA THROUGH THE DAY TUESDAY AS THE MAIN UPPER LOW AND ASSOCIATED
SURFACE LOW LIFT INTO THE EASTERN OHIO VALLEY. UPPER PATTERN THROUGH
THE MAJORITY OF THE REMAINDER OF THE EXTENDED FORECAST PERIOD
DOMINATED BY MODERATE TO STRONG NORTHWESTERLY FLOW AS BROAD BUT DEEP
UPPER TROUGH LINGERS OVER THE EASTERN U.S. TIGHT SURFACE PRESSURE
GRADIENT PERSISTS AS WELL THROUGH THE PERIOD WITH MODERATE TO STRONG
NORTHWESTERLY FLOW PERSISTING. GFS KEEPS LOW QPF ALONG OUR FAR
NORTHERN COUNTIES WEDNESDAY THROUGH SATURDAY WHILE THE ECMWF KEEPS
THE ENTIRE FORECAST AREA DRY THROUGH ALL BUT THURSDAY. HAVE KEPT THE
PREVIOUS TREND OF SLIGHT CHANCE POPS AND VERY LOW QPF FOR THE FAR
NORTH WEDNESDAY THROUGH SATURDAY. MODEL THICKNESSES AND TEMPERATURES
WOULD INDICATE A CHANCE FOR MIXED PRECIPITATION THROUGH THE
PERIOD...ALTHOUGH WITH THE LOW CHANCES AND LIMITED MOISTURE AVAILABLE
ANY AMOUNTS WOULD LIKELY BE VERY SMALL. THIS TREND WILL NEED TO BE
WATCHED CLOSELY AS WE MOVE INTO THE MIDDLE OF THE WEEK. HOWEVER THIS
PATTERN DOES POINT TO A PERIOD OF BELOW NORMAL TEMPERATURES THROUGH
THE EXTENDED FORECAST PERIOD.
20
HYDROLOGY...QPE FROM PREVIOUS EVENT INDICATES 2 INCHES OF RAIN
FELL FROM ROUGHLY THE ATLANTA METRO TO AS MUCH AS 4 INCHES FOR THE
SOUTHERN TIER. SAME AREA IS TARGETED FOR THIS EVENT WITH AN
ADDITIONAL 2 TO 3 INCHES EXPECTED AND HAVE ISSUED A FLOOD WATCH
THROUGH TUESDAY EVENING.
&&
.AVIATION...
12Z UPDATE...
CHALLENGING FORECAST SHOULD EASE AS LOW LEVEL MOISTURE CONTINUES
TO CLEAR. WILL STILL SEE AREAS OF LIFR FOR THE SOUTHERN MOST TAF
SITES BUT GUIDANCE AGREES EVEN THESE SHOULD IMPROVE RAPIDLY TO VFR
BY 14Z. VFR FOR THE REMAINDER OF THE PERIOD BUT WILL NEED TO ADD A
PROB30 FOR DEVELOPMENT OF -RA MONDAY MORNING. LOOKING FOR A
WINDSHIFT OVERNIGHT AS WELL WITH GOOD AGREEMENT AT A SWITCHOVER TO
EAST AFTER 06Z.
//ATL CONFIDENCE...12Z UPDATE...
HIGH ON ALL ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 67 38 47 41 / 0 0 90 100
ATLANTA 63 43 47 41 / 0 20 100 100
BLAIRSVILLE 57 35 47 38 / 0 0 70 100
CARTERSVILLE 62 37 48 45 / 0 0 90 100
COLUMBUS 68 50 52 47 / 0 60 100 90
GAINESVILLE 64 38 49 38 / 0 0 90 100
MACON 70 44 51 48 / 0 40 100 80
ROME 62 35 49 47 / 0 0 90 100
PEACHTREE CITY 64 35 48 45 / 0 30 100 100
VIDALIA 72 49 58 55 / 20 40 100 60
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM MONDAY MORNING THROUGH TUESDAY EVENING FOR THE
FOLLOWING ZONES: BALDWIN...BANKS...BARROW...BIBB...BLECKLEY...
BUTTS...CARROLL...CHATTAHOOCHEE...CLARKE...CLAYTON...COBB...
COWETA...CRAWFORD...CRISP...DEKALB...DODGE...DOOLY...DOUGLAS...
EMANUEL...FAYETTE...FORSYTH...GLASCOCK...GREENE...GWINNETT...
HALL...HANCOCK...HARRIS...HEARD...HENRY...HOUSTON...JACKSON...
JASPER...JEFFERSON...JOHNSON...JONES...LAMAR...LAURENS...MACON...
MADISON...MARION...MERIWETHER...MONROE...MONTGOMERY...MORGAN...
MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...PEACH...
PIKE...PULASKI...PUTNAM...ROCKDALE...SCHLEY...SOUTH FULTON...
SPALDING...STEWART...SUMTER...TALBOT...TALIAFERRO...TAYLOR...
TELFAIR...TOOMBS...TREUTLEN...TROUP...TWIGGS...UPSON...WALTON...
WARREN...WASHINGTON...WEBSTER...WHEELER...WILCOX...WILKES...
WILKINSON.
DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR THE FOLLOWING
ZONES: BALDWIN...BANKS...BARROW...BARTOW...BIBB...BLECKLEY...
BUTTS...CARROLL...CATOOSA...CHATTAHOOCHEE...CHATTOOGA...
CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...CRISP...
DADE...DAWSON...DEKALB...DODGE...DOOLY...DOUGLAS...EMANUEL...
FANNIN...FAYETTE...FLOYD...FORSYTH...GILMER...GLASCOCK...
GORDON...GREENE...GWINNETT...HALL...HANCOCK...HARALSON...
HARRIS...HEARD...HENRY...HOUSTON...JACKSON...JASPER...
JEFFERSON...JOHNSON...JONES...LAMAR...LAURENS...LUMPKIN...
MACON...MADISON...MARION...MERIWETHER...MONROE...MONTGOMERY...
MORGAN...MURRAY...MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...
OGLETHORPE...PAULDING...PEACH...PICKENS...PIKE...POLK...
PULASKI...PUTNAM...ROCKDALE...SCHLEY...SOUTH FULTON...SPALDING...
STEWART...SUMTER...TALBOT...TALIAFERRO...TAYLOR...TELFAIR...
TOOMBS...TOWNS...TREUTLEN...TROUP...TWIGGS...UNION...UPSON...
WALKER...WALTON...WARREN...WASHINGTON...WEBSTER...WHEELER...
WHITE...WHITFIELD...WILCOX...WILKES...WILKINSON.
&&
$$
SHORT TERM...DEESE
LONG TERM....20
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
451 AM MST SUN FEB 24 2013
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 416 AM MST SUN FEB 24 2013
MAIN FORECAST CONCERN WILL WINTER STORM THAT WILL AFFECT THE AREA
THROUGH MOST OF THE SHORT TERM. SATELLITE SHOWING A PROGRESSIVE FLOW
OVER THE PACIFIC. THIS TRANSITIONS TO A MORE AMPLIFIED AND SPLIT
FLOW OVER NORTH AMERICA. MAIN FEATURE OF INTEREST IS SYSTEM
DEVELOPING NEAR THE FOUR CORNERS.
AT JET LEVEL...THE ECMWF WAS DOING SLIGHTLY BETTER THAN THE REST OF
THE MODELS. AT MID LEVELS...SATELLITE AND UPPER AIR ANALYSIS WOULD
INDICATE THAT THE UKMET AND GFS HAVE THE BEST HANDLE ON INCOMING
STORM SYSTEM THROUGH. THE HIGH RESOLUTION NAM/RUC FOLLOWED BY THE
ECMWF GO THE SURFACE WIND/PRESSURE FIELD THE BEST. THE GFS AND NAM
WERE DOING SLIGHTLY BETTER ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...DRY MID LEVEL AIR IS BEING DRAWN UP AHEAD OF THE
UPPER SYSTEM. THIS IS ON TOP OF A RATHER MOIST LOW LEVELS PER
CURRENT OBSERVATIONS WITH STRATUS/FOG. MODELS SHOW THAT THE LEFT
FRONT QUADRANT IS AFFECT THE AREA AT 12Z. THIS MOVES SLOWLY SOUTH AND
EAST AND BY LATE AFTERNOON/EARLY EVENING IT IS SOUTH OF THE AREA.
COMPLEX UPPER LOW MOVES INTO THE AREA TODAY AND THEN SPLITS AND/OR
REDEVELOPS FURTHER SOUTH BEGINNING LATER TODAY INTO TONIGHT. MOST
NEW MODEL RUNS ARE FURTHER SOUTH WITH THIS LOW THAN YESTERDAY WITH
THE ENSEMBLES SHOWING THAT SAME TREND AS WELL. IN ADDITION TO BE
FURTHER SOUTH THE MODELS SHOWING THIS REDEVELOPMENT FURTHER WEST AS
WELL. MODELS ARE FURTHER WEST/SLOWER THAN YESTERDAY. ALL THESE TRENDS
MAKES SENSE WITH THE STRONGEST JET WINDS ON THE BACKSIDE OF THE
TROUGH WITH STILL LARGE HEIGHT FALLS AT THE BASE/BEHIND THE TROUGH.
SATELLITE SHOWING/CONFIRMING THIS NICELY.
VERY COMPLEX AND LOW CONFIDENCE FORECAST WITH A NUMBER OF ISSUES TO
ADDRESS. INITIALLY WILL HAVE DENSE FOG COVERING MOST OF THE AREA
THROUGH THE MORNING WITH THE MODELS STILL HAVING A HARD TIME WITH
THIS BUT THE HRRR SEEMS TO HAVE CAUGHT ONTO IT. BECAUSE OF THE
DRIER IN PLACE ABOVE THE SATURATED LOW LAYERS AND THE BETTER LIFT
FURTHER SOUTH AND WEST THAN BEFORE...ALSO NOT ALIGNING WELL WITH
EACH OTHER...AM NOT VERY OPTIMISTIC ABOUT VERY MUCH SNOW OCCURRING.
KEPT THE PATCHY FREEZING DRIZZLE IN THROUGH THE DAY. SNOW SHOULD
DEVELOP IN THE WEST ON THE BACKSIDE OF THE WEAKENING NORTHERN
PORTION OF THIS LOW. BY THE TIME THE SYSTEM GETS ITS ACT TOGETHER
IT IS TOO FAR SOUTH TO GIVE THE AREA A SIGNIFICANT AMOUNT OF SNOW.
SO ENDED UP CUTTING AMOUNTS. NEXT COMES THE WINDS WITH THIS SYSTEM.
BECAUSE OF THE FURTHER SOUTH AND WEST PATH OF THIS SYSTEM...THE
HIGHER WINDS HAVE BEEN PULLED FURTHER SOUTH AND WEST. DO EXPECT
BREEZY CONDITIONS BUT NOTHING STRONG ENOUGH TO WARRANT UPGRADING
THE BLIZZARD WATCH TO A WARNING.
SO BECAUSE OF THE DENSE FOG...JUST ENOUGH SNOW THAT WILL GET BLOWN
BY THE WIND...ADDED YUMA AND KIT CARSON TO THE WINTER WEATHER
ADVISORY AND EXPANDED THE ADVISORY THROUGH THE NIGHT SINCE EXPECT
BLOWING TO CONTINUE EVEN AFTER THE SNOW LETS UP. DUE TO THE MODELS
POOR HANDLING OF HIGH TEMPERATURES WITH THE SNOWFIELD...NOT VERY
CONFIDENT WITH THE MAXES TODAY WHICH ARE EVEN MORE COMPLEX.
MONDAY/MONDAY NIGHT...UPPER LOW KEEPS PULLING AWAY WITH THE OUTER
CONTOURS STILL NEAR THE AREA. GUT FEELING IS THAT DESPITE THE SIZE
OF THE SYSTEM...WITH IT MOVING AWAY AND THE DISTANCE IT IS FROM THE
AREA...FEEL THE QPF IS OVERBLOWN WITH MODELS AND SOME OF MY
NEIGHBORS HOLDING TO THIS TOO LONG. WILL KEEP THE A LOW CHANCE OF
SNOW BUT FEEL IT WILL NOT BE A LOT OF SNOW. WINDS WILL STAY UP AND
DEPENDING ON MUCH SNOW DOES FALL...THERE COULD BE SOME BLOWING SNOW
PROBLEMS. SO KEPT PATCHY BLOWING SNOW IN FOR THE FORECAST. HAVE NO
GOOD FEEL FOR TEMPERATURES.
TUESDAY/TUESDAY NIGHT...MODELS ALL OVER THE PLACE WITH HOW TO HANDLE
THIS TROUGH ONCE IT MOVES AWAY. THERE IS A POSSIBILITY OF SOME
LIGHT SNOW AND FLURRIES CONTINUING THROUGH THIS PERIOD.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY NIGHT)
ISSUED AT 300 AM MST SUN FEB 24 2013
WEDNESDAY-WEDNESDAY NIGHT...RATHER TIGHT PRESSURE GRADIENT ACROSS
THE AREA DURING THE DAY LEADING TO BREEZY/WINDY NORTHWEST WINDS.
CLOUDINESS WILL DECREASE FROM WEST TO EAST LATE IN THE DAY WITH
MOSTLY CLEAR/PARTLY CLOUDY CONDITIONS DURING THE NIGHT AS PRIOR DAYS
STORM SYSTEM CONTINUES TO MOVE AWAY FROM THE AREA.
THURSDAY-THURSDAY NIGHT...UPPER FLOW STARTS TO AMPLIFY OFF THE WEST
COAST WHILE IN OUR AREA IT APPEARS AN UPPER LEVEL DISTURBANCE MOVES
THROUGH FROM THE NORTH/NORTHWEST. SHOULD HAVE SOME INCREASE IN
CLOUDINESS WITH IT. WILL NEED TO WATCH FOR A SMALL THREAT FOR LIGHT
PRECIPITATION LATE THURSDAY AFTERNOON PER 850-500 MOISTURE. JET
POSITION AND 850-500 MOISTURE MAY BE A BIT MORE FAVORABLE ACROSS FAR
EASTERN COLORADO AROUND 12Z FRIDAY.
FRIDAY-FRIDAY NIGHT...AMPLIFIED UPPER RIDGE SLOWLY MOVES ONSHORE AND
ACROSS THE WESTERN 1/4 OF THE COUNTRY. SMALL CHANCE FOR PRECIP
ACROSS FAR EASTERN COLORADO AT 12Z FRIDAY SLIDES SOUTHEAST ACROSS
THE REMAINDER OF THE AREA DURING THE DAY WITH ANOTHER BATCH OF
MOISTURE ALONG/AHEAD OF APPROACHING UPPER JET MOVING IN LATE FRIDAY
NIGHT. WILL KEEP SILENT POPS GOING FOR NOW
SATURDAY-SATURDAY NIGHT...UPPER RIDGE CONTINUES TO MOVE SLOWLY EAST
AND BY THE END OF THE PERIOD SHOULD BE ALONG AND WEST OF THE
CONTINENTAL DIVIDE. SHOULD HAVE SCATTERED CLOUDINESS THROUGH THE
PERIOD WITH DRY CONDITIONS EXPECTED.
TEMPERATURES THROUGH THE PERIOD BELOW NORMAL...NOT ONLY FROM CURRENT
SNOW COVER BUT 850 TEMPERATURES. A SLIGHT WARMUP EXPECTED...MAINLY
ALONG AND WEST OF THE CO/KS BORDER SATURDAY AND SUNDAY UNDER THE
APPROACHING UPPER RIDGE WHERE WARMER 850 TEMPERATURES MOVE INTO THE
AREA.
THANKS TO ALL FOR COLLABORATION THROUGH THE WHOLE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 447 AM MST SUN FEB 24 2013
COMPLICATED TAFS WITH MODEL DATA HELPING MUCH AS THEY ARE HAVING
TROUBLE WITH THE CURRENT CONDITIONS. MODELS UNDERDOING THE EXTENT
OF THE DENSE FOG. THE HRRR AND TO A LESSER DEGREE THE RUC ARE
DOING WELL. VLIFR CONDITIONS ARE EXPECTED UNTIL LATE THIS
AFTERNOON TO EARLY AFTERNOON. IFR/LIFR CEILINGS ARE EXPECTED
THROUGH THE REST OF THE PERIOD. SNOW IS EXPECTED TO DEVELOP BUT
NOT UNTIL LATER THIS AFTERNOON TO EARLY EVENING. MVFR VSIBILITIES
ARE EXPECTED WHEN THE SNOW OCCURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 5 AM MST /6 AM CST/ MONDAY FOR
KSZ001>004-013>016-027>029-041-042.
CO...WINTER WEATHER ADVISORY UNTIL 5 AM MST MONDAY FOR COZ090>092.
NE...WINTER WEATHER ADVISORY UNTIL 5 AM MST /6 AM CST/ MONDAY FOR
NEZ079>081.
&&
$$
SHORT TERM...BULLER
LONG TERM...DDT
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
416 AM MST SUN FEB 24 2013
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 416 AM MST SUN FEB 24 2013
MAIN FORECAST CONCERN WILL WINTER STORM THAT WILL AFFECT THE AREA
THROUGH MOST OF THE SHORT TERM. SATELLITE SHOWING A PROGRESSIVE FLOW
OVER THE PACIFIC. THIS TRANSITIONS TO A MORE AMPLIFIED AND SPLIT
FLOW OVER NORTH AMERICA. MAIN FEATURE OF INTEREST IS SYSTEM
DEVELOPING NEAR THE FOUR CORNERS.
AT JET LEVEL...THE ECMWF WAS DOING SLIGHTLY BETTER THAN THE REST OF
THE MODELS. AT MID LEVELS...SATELLITE AND UPPER AIR ANALYSIS WOULD
INDICATE THAT THE UKMET AND GFS HAVE THE BEST HANDLE ON INCOMING
STORM SYSTEM THROUGH. THE HIGH RESOLUTION NAM/RUC FOLLOWED BY THE
ECMWF GO THE SURFACE WIND/PRESSURE FIELD THE BEST. THE GFS AND NAM
WERE DOING SLIGHTLY BETTER ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...DRY MID LEVEL AIR IS BEING DRAWN UP AHEAD OF THE
UPPER SYSTEM. THIS IS ON TOP OF A RATHER MOIST LOW LEVELS PER
CURRENT OBSERVATIONS WITH STRATUS/FOG. MODELS SHOW THAT THE LEFT
FRONT QUADRANT IS AFFECT THE AREA AT 12Z. THIS MOVES SLOWLY SOUTH AND
EAST AND BY LATE AFTERNOON/EARLY EVENING IT IS SOUTH OF THE AREA.
COMPLEX UPPER LOW MOVES INTO THE AREA TODAY AND THEN SPLITS AND/OR
REDEVELOPS FURTHER SOUTH BEGINNING LATER TODAY INTO TONIGHT. MOST
NEW MODEL RUNS ARE FURTHER SOUTH WITH THIS LOW THAN YESTERDAY WITH
THE ENSEMBLES SHOWING THAT SAME TREND AS WELL. IN ADDITION TO BE
FURTHER SOUTH THE MODELS SHOWING THIS REDEVELOPMENT FURTHER WEST AS
WELL. MODELS ARE FURTHER WEST/SLOWER THAN YESTERDAY. ALL THESE TRENDS
MAKES SENSE WITH THE STRONGEST JET WINDS ON THE BACKSIDE OF THE
TROUGH WITH STILL LARGE HEIGHT FALLS AT THE BASE/BEHIND THE TROUGH.
SATELLITE SHOWING/CONFIRMING THIS NICELY.
VERY COMPLEX AND LOW CONFIDENCE FORECAST WITH A NUMBER OF ISSUES TO
ADDRESS. INITIALLY WILL HAVE DENSE FOG COVERING MOST OF THE AREA
THROUGH THE MORNING WITH THE MODELS STILL HAVING A HARD TIME WITH
THIS BUT THE HRRR SEEMS TO HAVE CAUGHT ONTO IT. BECAUSE OF THE
DRIER IN PLACE ABOVE THE SATURATED LOW LAYERS AND THE BETTER LIFT
FURTHER SOUTH AND WEST THAN BEFORE...ALSO NOT ALIGNING WELL WITH
EACH OTHER...AM NOT VERY OPTIMISTIC ABOUT VERY MUCH SNOW OCCURRING.
KEPT THE PATCHY FREEZING DRIZZLE IN THROUGH THE DAY. SNOW SHOULD
DEVELOP IN THE WEST ON THE BACKSIDE OF THE WEAKENING NORTHERN
PORTION OF THIS LOW. BY THE TIME THE SYSTEM GETS ITS ACT TOGETHER
IT IS TOO FAR SOUTH TO GIVE THE AREA A SIGNIFICANT AMOUNT OF SNOW.
SO ENDED UP CUTTING AMOUNTS. NEXT COMES THE WINDS WITH THIS SYSTEM.
BECAUSE OF THE FURTHER SOUTH AND WEST PATH OF THIS SYSTEM...THE
HIGHER WINDS HAVE BEEN PULLED FURTHER SOUTH AND WEST. DO EXPECT
BREEZY CONDITIONS BUT NOTHING STRONG ENOUGH TO WARRANT UPGRADING
THE BLIZZARD WATCH TO A WARNING.
SO BECAUSE OF THE DENSE FOG...JUST ENOUGH SNOW THAT WILL GET BLOWN
BY THE WIND...ADDED YUMA AND KIT CARSON TO THE WINTER WEATHER
ADVISORY AND EXPANDED THE ADVISORY THROUGH THE NIGHT SINCE EXPECT
BLOWING TO CONTINUE EVEN AFTER THE SNOW LETS UP. DUE TO THE MODELS
POOR HANDLING OF HIGH TEMPERATURES WITH THE SNOWFIELD...NOT VERY
CONFIDENT WITH THE MAXES TODAY WHICH ARE EVEN MORE COMPLEX.
MONDAY/MONDAY NIGHT...UPPER LOW KEEPS PULLING AWAY WITH THE OUTER
CONTOURS STILL NEAR THE AREA. GUT FEELING IS THAT DESPITE THE SIZE
OF THE SYSTEM...WITH IT MOVING AWAY AND THE DISTANCE IT IS FROM THE
AREA...FEEL THE QPF IS OVERBLOWN WITH MODELS AND SOME OF MY
NEIGHBORS HOLDING TO THIS TOO LONG. WILL KEEP THE A LOW CHANCE OF
SNOW BUT FEEL IT WILL NOT BE A LOT OF SNOW. WINDS WILL STAY UP AND
DEPENDING ON MUCH SNOW DOES FALL...THERE COULD BE SOME BLOWING SNOW
PROBLEMS. SO KEPT PATCHY BLOWING SNOW IN FOR THE FORECAST. HAVE NO
GOOD FEEL FOR TEMPERATURES.
TUESDAY/TUESDAY NIGHT...MODELS ALL OVER THE PLACE WITH HOW TO HANDLE
THIS TROUGH ONCE IT MOVES AWAY. THERE IS A POSSIBILITY OF SOME
LIGHT SNOW AND FLURRIES CONTINUING THROUGH THIS PERIOD.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY NIGHT)
ISSUED AT 300 AM MST SUN FEB 24 2013
WEDNESDAY-WEDNESDAY NIGHT...RATHER TIGHT PRESSURE GRADIENT ACROSS
THE AREA DURING THE DAY LEADING TO BREEZY/WINDY NORTHWEST WINDS.
CLOUDINESS WILL DECREASE FROM WEST TO EAST LATE IN THE DAY WITH
MOSTLY CLEAR/PARTLY CLOUDY CONDITIONS DURING THE NIGHT AS PRIOR DAYS
STORM SYSTEM CONTINUES TO MOVE AWAY FROM THE AREA.
THURSDAY-THURSDAY NIGHT...UPPER FLOW STARTS TO AMPLIFY OFF THE WEST
COAST WHILE IN OUR AREA IT APPEARS AN UPPER LEVEL DISTURBANCE MOVES
THROUGH FROM THE NORTH/NORTHWEST. SHOULD HAVE SOME INCREASE IN
CLOUDINESS WITH IT. WILL NEED TO WATCH FOR A SMALL THREAT FOR LIGHT
PRECIPITATION LATE THURSDAY AFTERNOON PER 850-500 MOISTURE. JET
POSITION AND 850-500 MOISTURE MAY BE A BIT MORE FAVORABLE ACROSS FAR
EASTERN COLORADO AROUND 12Z FRIDAY.
FRIDAY-FRIDAY NIGHT...AMPLIFIED UPPER RIDGE SLOWLY MOVES ONSHORE AND
ACROSS THE WESTERN 1/4 OF THE COUNTRY. SMALL CHANCE FOR PRECIP
ACROSS FAR EASTERN COLORADO AT 12Z FRIDAY SLIDES SOUTHEAST ACROSS
THE REMAINDER OF THE AREA DURING THE DAY WITH ANOTHER BATCH OF
MOISTURE ALONG/AHEAD OF APPROACHING UPPER JET MOVING IN LATE FRIDAY
NIGHT. WILL KEEP SILENT POPS GOING FOR NOW
SATURDAY-SATURDAY NIGHT...UPPER RIDGE CONTINUES TO MOVE SLOWLY EAST
AND BY THE END OF THE PERIOD SHOULD BE ALONG AND WEST OF THE
CONTINENTAL DIVIDE. SHOULD HAVE SCATTERED CLOUDINESS THROUGH THE
PERIOD WITH DRY CONDITIONS EXPECTED.
TEMPERATURES THROUGH THE PERIOD BELOW NORMAL...NOT ONLY FROM CURRENT
SNOW COVER BUT 850 TEMPERATURES. A SLIGHT WARMUP EXPECTED...MAINLY
ALONG AND WEST OF THE CO/KS BORDER SATURDAY AND SUNDAY UNDER THE
APPROACHING UPPER RIDGE WHERE WARMER 850 TEMPERATURES MOVE INTO THE
AREA.
THANKS TO ALL FOR COLLABORATION THROUGH THE WHOLE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1013 PM MST SAT FEB 23 2013
MVFR HAS BECOME WIDESPREAD ACROSS THE AREA WITH FOG ALONG WITH
PATCHY AREAS OF LIFR AND VLIFR DUE TO FREEZING FOG AND LOW
CEILINGS. CONDITIONS WILL CONTINUE TO DETERIORATE ACROSS THE
REGION WITH IFR AND LIFR BECOMING WIDESPREAD BETWEEN 09Z AND 12Z
WITH AREAS OF VLIFR. AREAS OF FREEZING DRIZZLE ARE ALSO EXPECTED
TO DEVELOP AFTER 09Z. LOW CEILINGS AND VISIBILITIES WILL CONTINUE
THROUGH THE TAF PERIOD WITH LIGHT SOUTHEAST WINDS TURNING
NORTHEAST AND BECOMING GUSTY BY 16Z. LIGHT SNOW WILL BE COMMON
AFTER 16Z WITH AREAS OF BLOWING SNOW POSSIBLE AS WINDS CONTINUE TO
INCREASE AND TURN NORTHERLY AFTER 00Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 5 AM MST /6 AM CST/ MONDAY FOR
KSZ001>004-013>016-027>029-041-042.
CO...WINTER WEATHER ADVISORY UNTIL 5 AM MST MONDAY FOR COZ090>092.
NE...WINTER WEATHER ADVISORY UNTIL 5 AM MST /6 AM CST/ MONDAY FOR
NEZ079>081.
&&
$$
SHORT TERM...BULLER
LONG TERM...DDT
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
500 AM CST SUN FEB 24 2013
...UPDATE TO AVIATION FOR 12Z TAFS...
.SYNOPSIS...
ISSUED AT 352 AM CST SUN FEB 24 2013
THE 00Z UPPER AIR ANALYSIS SHOWED A MID/UPPER LEVEL TROUGH OVER THE
GREAT BASIN. THIS TROUGH CONTINUES TO DEEPEN AS IT MOVES SOUTHEAST
AND SHOULD CONTINUE TO DO SO GIVEN A 130 KNOT UPPER LEVEL JET ON THE
BACK SIDE OF THE UPPER TROUGH AND 130 METER HEIGHT FALLS TO ITS
SOUTHEAST. AT THE SURFACE, LOW PRESSURE WAS DEEPENING OVER NORTHEAST
NEW MEXICO. EAST OF THE LOW, UPPER 20S TO LOW 30S DEWPOINTS WERE
SPREADING NORTHWARD TOWARD THE CENTRAL HIGH PLAINS. AREAS OF FOG AND
LOW STRATUS WERE OCCURRING OVER WEST CENTRAL AND NORTHWEST KANSAS
EARLY THIS MORNING WITH SOME INDICATIONS OF DEVELOPMENT INTO
SOUTHWEST KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 352 AM CST SUN FEB 24 2013
VISIBILITIES ACROSS SOUTHWEST KANSAS HAVE BEEN STAYING MOSTLY IN THE
MVFR CATEGORY THROUGH THE EARLY MORNING HOURS WITH THE FAR NORTHERN
LOCATIONS AROUND HAYS SEEING VISIBILITIES OCCASIONALLY DROPPING TO A
QUARTER TO HALF MILE IN FOG. THE RUC13 AND HRRR ARE PICKING UP ON
THE FOG AND ARE SHOWING SOME SIGNIFICANT DEVELOPMENT TO THE SOUTH
ACROSS MUCH OF WEST CENTRAL AND SOUTHWEST KANSAS THROUGH THE NEXT
FEW HOURS THROUGH SUNRISE. THE 11-3.9U FOG CHANNEL HAS BEEN SHOWING
SOME HINTS OF FOG/STRATUS DEVELOPMENT AROUND COLDWATER/MEDICINE
LODGE AND GREENSBURG OVER THE PAST HOUR SO IT APPEARS THAT THERE IS
STILL POTENTIAL FOR THE FOG TO DEVELOP. HAVE LEFT THE DENSE FOG
ADVISORY IN PLACE THROUGH 9AM. IF NOTHING HAPPENS BY SUNRISE THEN
THE ADVISORY MAY BE ADJUSTED OR CANCELLED SOONER.
CONDITIONS ARE CONTINUING TO COME TOGETHER FOR A SIGNIFICANT WINTER
WEATHER EVENT ACROSS PARTS OF THE CENTRAL HIGH PLAINS STARTING THIS
EVENING AND CONTINUING THROUGH MONDAY EVENING. THE 00Z RUNS OF THE
NAM/GFS AND ECMWF ALL SHOW AN UPPER LOW CLOSING OFF OVER NEW MEXICO
BY THIS EVENING AND THEN INTENSIFYING AS IT TRACKS EAST INTO THE RED
RIVER VALLEY ON MONDAY. THE MODELS ARE ALL SHOWING PRECIPITATION
DEVELOPING ACROSS SOUTHWEST KANSAS LATE THIS AFTERNOON AND TONIGHT.
INITIAL PRECIPITATION COULD BE IN THE FORM OF FREEZING DRIZZLE OVER
FAR WESTERN KANSAS BUT THINK THIS WILL BE SHORT LIVED AS THE MID
LEVELS MOISTEN UP AND THE RESULTANT SEEDER/FEEDER MECHANISM CHANGES
PRECIPITATION OVER TO SNOW. FAR SOUTH CENTRAL KANSAS MAY SEE A
RAIN/SNOW MIX FOR A TIME TONIGHT AS TEMPERATURES IN THE LOWER LEVELS
HOVER AT OR SLIGHTLY ABOVE ZERO. AT ANY RATE, SNOW SHOULD BE
DEVELOPING OVER ALL OF SOUTHWEST AND CENTRAL KANSAS AS THE NIGHT
GOES ON AND BECOME HEAVY AT TIMES. SNOWFALL ACCUMULATIONS COULD BE
AS MUCH AS TWO TO FIVE INCHES BY MONDAY MORNING. WITH NORTH WINDS
EXPECTED TO INCREASE TO AROUND 25 TO 35 MPH, THERE WILL BE
CONSIDERABLE BLOWING AND DRIFTING SNOW WITH WIDESPREAD VISIBILITIES
AT A QUARTER MILE OR LESS EXPECTED. WITH THIS IN MIND, HAVE UPGRADED
THE BLIZZARD WATCH TO A BLIZZARD WARNING FOR ALL OF SOUTHWEST INTO
WEST CENTRAL AND SOUTH CENTRAL KANSAS TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 400 AM CST SUN FEB 24 2013
BLIZZARD CONDITIONS WILL CONTINUE MONDAY. VERY DANGEROUS TRAVEL CONDITIONS
ARE EXPECTED ACROSS THE REGION WITH HEAVY MESOSCALE SNOW BANDS DEVELOPING
IN THE 700 HPA DEFORMATION AXIS IN COMBINATION WITH 30 KT SURFACE WINDS.
THE 00Z GUIDANCE STILL SUPPORTS THE ONGOING FORECAST WITH HEAVY SNOW
ACROSS KANSAS. THE NAM SUGGESTS AS HIGH AS 60 KT 850 HPA WINDS, WHICH
WOULD MEAN SUSTAINED WINDS POSSIBLY AS HIGH AS 35-40 KT AT THE SURFACE.
THE ECMWF IS WEAKER WITH THE WIND PROFILE. TRAVEL IS NOT RECOMMENDED
MONDAY...IT WILL BE VERY UNSAFE TRAVEL CONDITIONS WITH WHITEOUT CONDITIONS
AND VERY LARGE SNOWDRIFTS. FOR MORE SPECIFIC INFORMATION REGARDING THE
BLIZZARD, PLEASE SEE THE WARNING TEXT /WSWDDC/. CONDITIONS WILL TAPER
WEST TO EAST THROUGH TUESDAY MORNING AS THE CYCLONE MOVES SOUTHEAST
OF THE REGION.
THE REST OF THE FORECAST WAS LEFT AS IS FROM THE ALLBLEND SOLUTION DUE
TO TIME CONSTRAINTS. HIGHS WILL MODERATE INTO THE 30S AND 40S BY MIDWEEK,
ALTHOUGH THE ALLBLEND NUMBERS COULD BE ON THE HIGH SIDE IF THE HEAVY
SNOWPACK DOES COME INTO FRUITION. LOWS WILL BE IN THE TEENS AND 20S.
AGAIN, THESE VALUES COULD BE ON THE HIGH SIDE IF WE GET SIGNIFICANT
ADDITIONAL SNOWS. THE REST OF THE FORECAST LOOKS DRY AS UPPER LEVEL
RIDGING DEVELOPS OUT WEST AND A DRY NORTHERLY FLOW PATTERN PREVAILS
ACROSS WESTERN KANSAS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 500 AM CST SUN FEB 24 2013
LIFR CONDITIONS THIS MORNING IN ASSOCIATION WITH FOG. IMPROVEMENT TO
MVFR LATE MORNING AS FOG ERODES. LIFR CONDITIONS LIKELY AGAIN THIS
EVENING AS BLIZZARD STARTS WITH DETERIORATING CONDITIONS THEREAFTER.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 32 24 32 18 / 40 90 90 60
GCK 32 22 33 13 / 40 80 80 30
EHA 32 18 33 16 / 40 80 80 30
LBL 33 21 33 14 / 30 90 90 30
HYS 30 24 31 21 / 40 80 80 60
P28 34 28 32 25 / 30 90 90 80
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST /8 AM MST/ THIS MORNING FOR
KSZ030-031-043>046-061>066-074>081-084>090.
BLIZZARD WARNING FROM 6 PM CST /5 PM MST/ THIS EVENING TO
MIDNIGHT CST /11 PM MST/ MONDAY NIGHT FOR KSZ030-031-043>046-
061>066-074>081-084>090.
&&
$$
SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...SUGDEN
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
400 AM CST SUN FEB 24 2013
...UPDATE TO LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 352 AM CST SUN FEB 24 2013
THE 00Z UPPER AIR ANALYSIS SHOWED A MID/UPPER LEVEL TROUGH OVER THE
GREAT BASIN. THIS TROUGH CONTINUES TO DEEPEN AS IT MOVES SOUTHEAST
AND SHOULD CONTINUE TO DO SO GIVEN A 130 KNOT UPPER LEVEL JET ON THE
BACK SIDE OF THE UPPER TROUGH AND 130 METER HEIGHT FALLS TO ITS
SOUTHEAST. AT THE SURFACE, LOW PRESSURE WAS DEEPENING OVER NORTHEAST
NEW MEXICO. EAST OF THE LOW, UPPER 20S TO LOW 30S DEWPOINTS WERE
SPREADING NORTHWARD TOWARD THE CENTRAL HIGH PLAINS. AREAS OF FOG AND
LOW STRATUS WERE OCCURRING OVER WEST CENTRAL AND NORTHWEST KANSAS
EARLY THIS MORNING WITH SOME INDICATIONS OF DEVELOPMENT INTO
SOUTHWEST KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 352 AM CST SUN FEB 24 2013
VISIBILITIES ACROSS SOUTHWEST KANSAS HAVE BEEN STAYING MOSTLY IN THE
MVFR CATEGORY THROUGH THE EARLY MORNING HOURS WITH THE FAR NORTHERN
LOCATIONS AROUND HAYS SEEING VISIBILITIES OCCASIONALLY DROPPING TO A
QUARTER TO HALF MILE IN FOG. THE RUC13 AND HRRR ARE PICKING UP ON
THE FOG AND ARE SHOWING SOME SIGNIFICANT DEVELOPMENT TO THE SOUTH
ACROSS MUCH OF WEST CENTRAL AND SOUTHWEST KANSAS THROUGH THE NEXT
FEW HOURS THROUGH SUNRISE. THE 11-3.9U FOG CHANNEL HAS BEEN SHOWING
SOME HINTS OF FOG/STRATUS DEVELOPMENT AROUND COLDWATER/MEDICINE
LODGE AND GREENSBURG OVER THE PAST HOUR SO IT APPEARS THAT THERE IS
STILL POTENTIAL FOR THE FOG TO DEVELOP. HAVE LEFT THE DENSE FOG
ADVISORY IN PLACE THROUGH 9AM. IF NOTHING HAPPENS BY SUNRISE THEN
THE ADVISORY MAY BE ADJUSTED OR CANCELLED SOONER.
CONDITIONS ARE CONTINUING TO COME TOGETHER FOR A SIGNIFICANT WINTER
WEATHER EVENT ACROSS PARTS OF THE CENTRAL HIGH PLAINS STARTING THIS
EVENING AND CONTINUING THROUGH MONDAY EVENING. THE 00Z RUNS OF THE
NAM/GFS AND ECMWF ALL SHOW AN UPPER LOW CLOSING OFF OVER NEW MEXICO
BY THIS EVENING AND THEN INTENSIFYING AS IT TRACKS EAST INTO THE RED
RIVER VALLEY ON MONDAY. THE MODELS ARE ALL SHOWING PRECIPITATION
DEVELOPING ACROSS SOUTHWEST KANSAS LATE THIS AFTERNOON AND TONIGHT.
INITIAL PRECIPITATION COULD BE IN THE FORM OF FREEZING DRIZZLE OVER
FAR WESTERN KANSAS BUT THINK THIS WILL BE SHORT LIVED AS THE MID
LEVELS MOISTEN UP AND THE RESULTANT SEEDER/FEEDER MECHANISM CHANGES
PRECIPITATION OVER TO SNOW. FAR SOUTH CENTRAL KANSAS MAY SEE A
RAIN/SNOW MIX FOR A TIME TONIGHT AS TEMPERATURES IN THE LOWER LEVELS
HOVER AT OR SLIGHTLY ABOVE ZERO. AT ANY RATE, SNOW SHOULD BE
DEVELOPING OVER ALL OF SOUTHWEST AND CENTRAL KANSAS AS THE NIGHT
GOES ON AND BECOME HEAVY AT TIMES. SNOWFALL ACCUMULATIONS COULD BE
AS MUCH AS TWO TO FIVE INCHES BY MONDAY MORNING. WITH NORTH WINDS
EXPECTED TO INCREASE TO AROUND 25 TO 35 MPH, THERE WILL BE
CONSIDERABLE BLOWING AND DRIFTING SNOW WITH WIDESPREAD VISIBILITIES
AT A QUARTER MILE OR LESS EXPECTED. WITH THIS IN MIND, HAVE UPGRADED
THE BLIZZARD WATCH TO A BLIZZARD WARNING FOR ALL OF SOUTHWEST INTO
WEST CENTRAL AND SOUTH CENTRAL KANSAS TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 400 AM CST SUN FEB 24 2013
BLIZZARD CONDITIONS WILL CONTINUE MONDAY. VERY DANGEROUS TRAVEL CONDITIONS
ARE EXPECTED ACROSS THE REGION WITH HEAVY MESOSCALE SNOW BANDS DEVELOPING
IN THE 700 HPA DEFORMATION AXIS IN COMBINATION WITH 30 KT SURFACE WINDS.
THE 00Z GUIDANCE STILL SUPPORTS THE ONGOING FORECAST WITH HEAVY SNOW
ACROSS KANSAS. THE NAM SUGGESTS AS HIGH AS 60 KT 850 HPA WINDS, WHICH
WOULD MEAN SUSTAINED WINDS POSSIBLY AS HIGH AS 35-40 KT AT THE SURFACE.
THE ECMWF IS WEAKER WITH THE WIND PROFILE. TRAVEL IS NOT RECOMMENDED
MONDAY...IT WILL BE VERY UNSAFE TRAVEL CONDITIONS WITH WHITEOUT CONDITIONS
AND VERY LARGE SNOWDRIFTS. FOR MORE SPECIFIC INFORMATION REGARDING THE
BLIZZARD, PLEASE SEE THE WARNING TEXT /WSWDDC/. CONDITIONS WILL TAPER
WEST TO EAST THROUGH TUESDAY MORNING AS THE CYCLONE MOVES SOUTHEAST
OF THE REGION.
THE REST OF THE FORECAST WAS LEFT AS IS FROM THE ALLBLEND SOLUTION DUE
TO TIME CONSTRAINTS. HIGHS WILL MODERATE INTO THE 30S AND 40S BY MIDWEEK,
ALTHOUGH THE ALLBLEND NUMBERS COULD BE ON THE HIGH SIDE IF THE HEAVY
SNOWPACK DOES COME INTO FRUITION. LOWS WILL BE IN THE TEENS AND 20S.
AGAIN, THESE VALUES COULD BE ON THE HIGH SIDE IF WE GET SIGNIFICANT
ADDITIONAL SNOWS. THE REST OF THE FORECAST LOOKS DRY AS UPPER LEVEL
RIDGING DEVELOPS OUT WEST AND A DRY NORTHERLY FLOW PATTERN PREVAILS
ACROSS WESTERN KANSAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1151 PM CST SAT FEB 23 2013
WEAK UPSLOPE FLOW AND A MOIST BOUNDARY LAYER WILL AID IN THE
DEVELOPMENT OF FOG AND STRATUS LATER TONIGHT. THE LOW STRATUS AND
FOG WAS ALREADY DEVELOPING ALONG THE COLORADO BORDER AND IS EXPECTED
TO CONTINUE TO DEVELOP EASTWARD ACROSS SOUTHWEST INTO CENTRAL KANSAS
THROUGH THE PREDAWN HOURS. PREDOMINANTLY IFR CONDITIONS ARE EXPECTED
BY SUNRISE. VSBYS COULD IMPROVE TO MVFR DURING THE DAY ALONG WITH
SOME BREAKS IN THE LOW CLOUDS BUT ANY IMPROVEMENT WILL BE SHORT LIVED.
WINDS WILL SWITCH AROUND TO THE NORTH BY 00Z MONDAY AND SHOULD BE
INCREASING INTO THE 15 TO 25 KNOT RANGE DURING THE EVENING HOURS.
SOME LIGHT SNOW IS ALSO EXPECTED TO DEVELOP
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 32 24 32 18 / 40 90 90 60
GCK 32 22 33 13 / 40 80 80 30
EHA 32 18 33 16 / 40 80 80 30
LBL 33 21 33 14 / 30 90 90 30
HYS 30 24 31 21 / 40 80 80 60
P28 34 28 32 25 / 30 90 90 80
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST /8 AM MST/ THIS MORNING FOR
KSZ030-031-043>046-061>066-074>081-084>090.
BLIZZARD WARNING FROM 6 PM CST /5 PM MST/ THIS EVENING TO
MIDNIGHT CST /11 PM MST/ MONDAY NIGHT FOR KSZ030-031-043>046-
061>066-074>081-084>090.
&&
$$
SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...SUGDEN
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS CARIBOU ME
935 AM EST SUN FEB 24 2013
.SYNOPSIS...
LOW PRESSURE IS EXPECTED TO PASS SOUTH OF THE REGION TODAY AND
PASS SOUTH OF NOVA SCOTIA TONIGHT. HIGH PRESSURE WILL BUILD IN
TO THE REGION ON MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
930 AM UPDATE...CHALLENGING FORECAST FOR TODAY AS A NORLUN-TYPE
EVENT LOOKS TO BE SETTING UP. THE CHALLENGE IS PREDICTING EXACTLY
WHERE THE BAND OF SNOW IS GOING TO DEVELOP, BUT BASED ON CURRENT
RADAR AND THE 3KM HRRR MODEL, BELIEVE THE HEAVIEST SNOW WILL BE
WEST OF AN ELLSWORTH-BANGOR-GREENVILLE LINE. OTHER THAN SOME MINOR
TWEAKS, HAVE KEPT THE PREVIOUS SHIFT`S SNOWFALL AMOUNTS UNTIL THE
SNOW BAND SETTLES IN PLACE. DID BACK DOWN ON POPS OVER NORTHERN
AREAS THOSE AREAS SHOULD SEE JUST SCATTERED SNOW SHOWERS THROUGH
THE REMAINDER OF THE DAY. THE REST OF THE FORECAST IS IN GOOD
SHAPE AND NO OTHER CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...THE CHALLENGE THIS TERM WILL BE THE SNOW
AND WHETHER OR NOT TO EXTEND THE WINTER WEATHER ADVISORIES FURTHER
N AND E. DETAILS BELOW AND LENGTHY.
FIRST BATCH OF SNOW DIMINISHING SOME AS MID LEVEL FORCING HAS
WEAKENED FOR THE TIME BEING. 07Z SFC ANALYSIS SHOWED INVERTED
TROF HOLDING ACROSS WESTERN AND NORTHERN MAINE W/HIGH PRES HOLDING
STRONG INTO EASTERN MAINE. RECEIVED REPORTS OF 2-3 INCHES IN
SOUTHERN PISCATAQUIS COUNTY AND PORTIONS OF SWRN PENOBSCOT COUNTY.
THE OTHER CONCERN WILL BE ACROSS THE FAR NWRN AREA FOR THE ST.
JOHN VALLEY AS THE RADAR DOES SHOW ANOTHER BAND SETTING UP THIS
MORNING IN THE INVERTED TROF. THIS COULD TIP SNOWFALL AMOUNTS NEAR
ADVISORY CRITERIA W/IN THE 24 HR PERIOD. THIS WILL NEED TO BE
WATCHED. FURTHER S, LOW PRES OFF THE NJ COAST IS MOVING ENE AND IS
FCST TO REMAIN WELL S OF THE GULF OF MAINE BUT WILL PLAY A ROLE
AND THIS IS MENTIONED BELOW.
THE LATEST REGIONAL RADAR HAS PRECIP SHIELD FILLING BACK IN
ACROSS SRN MAINE AND MOVING NE TOWARD THE DOWNEAST REGION. ATTM,
THE UPPER LEVEL LOW IS FCST TO REORGANIZE E OF NANTUCKET AND MOVE
E. THIS SETUP APPEARS SIMILAR TO A NORLUN SETUP W/AN INVERTED TROF
EXTENDING OFF THE SFC LOW BACK ACROSS SRN MAINE. THE 00Z NAM/CANADIAN
GEM AND TO SOME EXTENT THE GFS HAD A DECENT HANDLE ON THE LATEST
SETUP PER THE RADAR AND SFC ANALYSIS. Q-VECTOR FORCING FCST TO
SET UP BACK ACROSS INTERIOR DOWNEAST EXTENDING BACK UP INTO THE
CENTRAL HIGHLANDS(GNR-KOKADJO) TODAY RIGHT INTO EARLY TONIGHT AND
THEN WEAKEN. THIS WOULD ENHANCE SNOWFALL ACROSS THE CENTRAL
HIGHLANDS DOWN TO THE COAST, WHILE FURTHER N, THE FORCING IS SHOWN
TO WEAKEN BY THE AFTERNOON. THEREFORE, DECIDED TO BOOST SNOWFALL
TOTALS ESPECIALLY IN THE ADVISORY AREA USING A 17-20:1 SNOWFALL
RATIO GIVEN WHAT HAD FALLEN OVERNIGHT W/HIGH RATIOS. THIS MATCHES
UP WELL W/THE LATEST BUFKIT SHOWING DECENT SNOW IN THE DENTRITIC
ZONE ABOVE 850MBS. THIS MEANS SNOWFALL TOTALS OF 4 TO 7 INCHES
W/THE HIGHEST TOTALS FOR THE INTERIOR DOWNEAST TO THE COAST. THE
SNOWFALL TOTALS RUN FROM LAST NIGHT THROUGH TONIGHT WHICH COVER A
30HR PERIOD. THE NAM INDICATES A PERIOD OF POSSIBLY HEAVY SNOWFALL
IN A NARROW CORRIDOR FORM BANGOR TO ELLSWORTH AND POSSIBLY THE BAR
HARBOR. THIS WILL BE MONITORED FURTHER THIS MORNING.
THE ACTIVITY IS FCST TO WIND DOWN TONIGHT AS THE LOW PULLS FURTHER
AWAY AND THE FORCING WEAKENS. FOR THE POPS, USED THE SREF/GFS AND
NAM AND THEN ADJUSTED MANUALLY THIS MORNING TO FIT THE RADAR TRENDS.
THE QPF FOR THIS EVENT IS A BLEND OF HPC/GFS AND 00Z NERFC WHICH
SHOWS .30-.50 INCHES IN THE ADVISORY AREA W/THE HIGHEST TOTALS
ACROSS THE DOWNEAST REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LOW PRESSURE WILL CONTINUE TO MOVE WELL EAST OF THE NEW ENGLAND
COAST MONDAY. LOW CLOUDS WILL LIKELY LINGER FOR A TIME AT LEAST FOR
THE FIRST PART OF THE DAY BEFORE DRIER AIR AND INCREASING SUBSIDENCE
ASSOCIATED WITH HIGH PRESSURE BUILDING IN FROM THE WEST ALLOWS FOR
AT LEAST PARTIAL CLEARING LATER MONDAY AFTERNOON.
MONDAY NIGHT SHOULD SEE MAINLY CLEAR TO PARTLY CLOUDY SKIES ACROSS
THE FA WITH SURFACE HIGH PRESSURE ACROSS THE REGION. SOME
RADIATIONAL COOLING IS LIKELY ESPECIALLY ACROSS NORTHERN AND EASTERN
PORTIONS.
THE SURFACE HIGH WILL MOVE EAST TUESDAY WITH INCREASING CLOUDS
DURING TUESDAY AFTERNOON.
HIGH TEMPERATURES BOTH MONDAY AND TUESDAY WILL BE ABOVE NORMAL FOR
THIS TIME OF YEAR WITH LOWER 30S NORTH AND MID TO UPPER 30S
DOWNEAST. LOW TEMPERATURES MONDAY NIGHT WILL RANGE FROM ZERO TO 5
ABOVE ACROSS THE SJV TO THE MID TO UPPER TEENS ACROSS INTERIOR
DOWNWEAST AND COASTAL MAINE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
CUTOFF LOW SLOWLY MOVE EAST OF THE NEW ENGLAND COAST THROUGH
FRIDAY. THIS SYSTEM WILL LIKELY KEEP AN UNSETTLED WEATHER PATTERN
ACROSS THE REGION THROUGH MUCH OF THE MID TO LATE WEEK PERIOD.
STILL PREFER THE DRIER ECMWF SOLUTION FOR WEDNESDAY WITH
MODERATELY STRONG SURFACE HIGH TO THE NORTH OF THE FORECAST AREA.
THUS...WILL CONTINUE TO ADVERTISE DRY WEATHER ACROSS NORTHER AND
EASTERN PORTIONS OF THE FA WEDNESDAY WITH CHANCE POPS DOWNEAST.
BEYOND WEDNESDAY WILL CONTINUE TO ADVERTISE CHANCE TO LOW END
LIKELY POPS AS THE HIGH TO THE NORTH BEGINS TO BREAK DOWN.
PRECIPITATION TYPE DURING THIS PERIOD WILL LIKELY BE SNOW OR
RAINSHOWERS BY DAY WITH SURFACE TEMPERATURES IN THE LOW TO MID 30S
AND SNOW SHOWERS BY NIGHT.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: MVFR/IFR EXPECTED THROUGH TONIGHT W/SNOW FOR ALL THE
TERMINALS. THERE IS EXPECTED TO BE PERIODS OF VFR EARLY TODAY.
SHORT TERM: MVFR CIGS ARE EXPECTED THROUGH MONDAY MORNING THEN
CIGS SHOULD LIFT TO VFR BY MONDAY AFTERNOON. VFR CONDITIONS ARE
EXPECTED MONDAY NIGHT THROUGH TUE. MVFR CONDITIONS LIKELY WED AND
THU.
&&
.MARINE...
NEAR TERM: SCA CONTINUES AND WILL POSSIBLY NEED TO BE EXTENDED
INTO TONIGHT ESPECIALLY FOR HAZARDOUS SEAS. ATTM, CONDITIONS ARE
BELOW SCA LEVELS BUT ARE PICKING UP. EXPECTATION IS THAT WINDS
WILL BE CLOSE TO SCA BY LATER THIS MORNING INTO EARLY AFTERNOON
AND THEN FALL BACK AS THE LOW PULLS AWAY. A SWELL COMPONENT IS
EXPECTED TO SET UP LATER TODAY AND CONTINUE THROUGH TONIGHT. THIS
COULD VERY WELL KEEP WAVE HEIGHTS ABV 6 FT.
SHORT TERM: WINDS/SEAS WILL REMAIN BELOW SCA LEVELS THROUGH MONDAY
THROUGH TUE NIGHT. WINDS/SEAS WILL INCREASE TO SCA LEVELS BY
WED.&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MEZ003-
004-010-015-016-029-031.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO MIDNIGHT EST
TONIGHT FOR ANZ050>052.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MEZ003-
004-010-015-016-029-031.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ050>052.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
626 AM EST SUN FEB 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM EST SUN FEB 24 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED LO THAT HAS
BROUGHT SN/SHSN TO UPR MI THE LAST FEW DAYS MOVING SLOWLY TO THE E
AS UPR RDG AXIS EXTENDING FM HUDSON BAY INTO THE NRN PLAINS DRIFTS
SLOWLY TO THE E. COMBINATION OF LINGERING CYC NLY FLOW AND DEEP MSTR
SHOWN ON THE 00Z APX RAOB HAS ALLOWED SOME SHSN TO PERSIST OVER
MAINLY THE E HALF OF THE CWA UNDER POCKET OF H85/7 TEMPS AS LO AS
-11C/-17C...BUT THE CYC FLOW IS TENDING TO WEAKEN WITH SFC LO
SHIFTING TO THE E. IN FACT...THE WINDS AT STANNARD ROCK HAVE FALLEN
NEAR 5KTS EARLY THIS MRNG. 00Z RAOBS AT INL/YPL TO THE W/NW ALSO
SHOW A PRONOUNCED DRYING TREND ASSOCIATED WITH INCOMING RDG...WHICH
DROPPED THE INVRN BASE AS LO AS H9 AT YPL AT 00Z. 00Z H85 TEMPS
RANGE FM -11C AT GRB TO -6C AT INL AND -5C AT YPL. RECENT RADAR
TRENDS SHOW PERSISTENT HEAVIER SHSN THAT IMPACTED THE MQT AREA ARE
DIMINISHING WITH WEAKENING FLOW/SOME UPR DRYING UNDER DEEP LYR
QVECTOR DVGC/SUBSIDENCE LEFT IN THE WAKE OF SLOWLY DEPARTING CLOSED
LO. BUT SFC OBS/STLT IMAGERY SHOW LO CLDS LINGERING W INTO THE MN
ARROWHEAD. SKIES HAVE CLEARED OVER CNTRL MN UNDER SFC RDG AXIS.
FARTHER TO THE W...THERE IS A SHRTWV MOVING THRU SASKATCHEWAN.
PLENTY OF MID/HI CLDS ARE PRESENT TO THE E OF THIS DISTURBANCE...BUT
PCPN APPEARS LIMITED BY RATHER DRY LLVLS SHOWN ON THE 00Z BISMARCK
RAOB. ANOTHER MORE POTENT SHRTWV IS MOVING THRU THE SCENTRAL
ROCKIES. OTRW...THERE IS A LACK OF TRUE ARCTIC AIR OVER THE NRN
CONUS/SRN CANADA. IN FACT...THE 00Z H85 TEMP OF -11C AT GRB IS THE
LOWEST H85 TEMP IN CANADA S OF THE NW TERRITORIES AND NRN QUEBEC.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON CLD TRENDS/
IMPACT ON TEMPS.
TODAY...AS CLOSED LO SLIDES TO THE E...UPR RDG IS PROGGED TO BLD
OVER THE UPR LKS...RESULTING IN 12HR H5 HGT RISES UP TO 100M UNDER
INFLUENCE OF DEEP LYR QVECTOR DVGC/SUBSIDENCE. WITH SFC HI PRES RDG
AXIS FCST TO SHIFT INTO THE W HALF OF THE CWA BY 00Z MON...EXPECT
ANY LINGERING -SHSN TO END W-E. WITH LLVL NW FLOW PERSISTING THRU
THE DAY OVER THE E AHEAD OF INCOMING RDG AXIS...MIGHT EXPECT AT
LEAST SCT -SHSN TO PERSIST THERE. BUT FCST H85 TEMPS TO -8C TO -9C
IN THAT AREA /COMPARED TO LK WATER TEMPS 1 TO 2C/ BY 00Z AS WELL AS
DIFFLUENT NATURE OF THE INCRSG ACYC FLOW INDICATE THE ACTIVITY WL
END EVEN THERE IN THE AFTN. CLD TRENDS WL BE MORE DIFFICULT TO PIN
DOWN. AS THE SFC RDG AXIS ARRIVES...FCST SDNGS SHOWN INVRN BASE
SINKING TOWARD H9...WHICH MIGHT TRAP LINGERING LLVL MSTR AND RESULT
IN SC OVC. BUT WITH ACYC LLVL FLOW...SUSPECT SOME BREAKS IN THE CLDS
MAY DVLP OVER THE W NEAR THE WI BORDER LATER IN THE DAY...WHICH IS
CONSISTENT WITH THE CLRG OBSVD EARLY THIS MRNG CLOSER TO THE RDG
AXIS IN MN. AREAS OVER THE SCENTRAL FARTHER FM LK SUP INFLUENCE MAY
ALSO SEE SOME CLRG DESPITE RATHER WEAK WINDS/DOWNSLOPE IMPACT.
TNGT...THE SFC RDG AXIS IS PROGGED TO DRIFT SLOWLY TO THE E TNGT.
WITH WSHFT TO THE SW...EXPECT AT LEAST SOME BREAKS IN THE LINGERING
LO CLDS. WITH LGT WINDS...LOCATIONS THAT SEE SOME CLRG MIGHT SEE
TEMPS DROP SHARPLY. SO MAINTAINED FLAVOR OF GOING FCST SHOWING MIN
TEMPS DROPPING TOWARD THE LO END OF GUIDANCE. SOME HI CLDS AHEAD OF
SHRTWV MOVING ACRS SCENTRAL CANADA MAY MOVE INTO THE W LATE. SINCE
FOG HAS DVLPD UPSTREAM WHERE SKIES CLEARED IN MN...ADDED A MENTION
OF PATCHY FOG OVER THE INTERIOR AFTER MIDNGT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 323 AM EST SUN FEB 24 2013
MUCH OF THE WEATHER FOR THE LONG TERM WILL BE DOMINATED BY THE
CURRENT 500MB LOW/TROUGH CENTERED OVER UTAH AND WESTERN COLORADO.
LOOK FOR THE LOW TO DEEPEN AS IT ROUNDS NORTHERN TEXAS ON
MONDAY...WITH A DISTINCT/WRAPPED UP SFC LOW DEVELOPING.
EXPECT A PROLONGED PERIOD OF WINDS FROM THE NORTHEAST QUADRANT
/360-90 DEGREES/ FROM TUESDAY THROUGH AT LEAST SATURDAY. IF
TEMPERATURES WERE COLDER WE WOULD BE LOOKING AT AN EXTENDED PERIOD
OF MODERATE LAKE EFFECT SNOW SHOWERS ACROSS MUCH OF THE AREA...AND
PARTICULAR NORTH CENTRAL UPPER MICHIGAN. HOWEVER...SURFACE TEMPS
NEAR FREEZING AND 850MB TEMPS -3C TO -5C TUESDAY THROUGH WEDNESDAY
WILL ONLY SUPPORT SOME LAKE ENHANCEMENT TO THE SNOW ROTATING AROUND
THE BACK SIDE OF THE SURFACE LOW FROM TUESDAY NIGHT ON.
THE GFS REMAINS STRONGEST WITH THE N/NNE WINDS THROUGH MUCH OF THE
PERIOD...WITH WINDS NEAR OR ABOVE 30KTS FROM WEDNESDAY AFTERNOON
THROUGH FRIDAY ACROSS LAKE SUPERIOR. THE ECMWF RANGES FROM 3-9KTS
LIGHTER WITH THE WINDS...THANKS TO THE OVERALL WEAKER LOW EJECTING
FROM THE SOUTHERN PLAINS AND ACROSS ILLINOIS TUESDAY...AND OVER
LOWER MICHIGAN WEDNESDAY. THIS IS THE MAIN DIFFERENCE...WHETHER THE
LOW ENDS UP BEING 992MB /23/18Z GFS/ OR 1000MB /23/12Z ECMWF/ AS IT
CROSSES INTO SOUTHERN LOWER MI WEDNESDAY MORNING. EVEN THROUGH THE
TRACK OF THE SFC LOW MAY BE A BIT ON THE QUICK SIDE OFF OF THE
ECMWF...THE CONSENSUS IS TO HAVE A WEAKER SYSTEM THAN WHAT IS
INDICATED BY THE GFS. THE 00Z RUN OF THE GFS CAME IN SLIGHTLY WEAKER
AND FARTHER S OF ITS 18Z RUN TRACK /APPROX 250MI SSE OF THE 18Z RUN
LOW AT 12Z THURSDAY/...WHICH ALSO DIMINISHED WIND SPEEDS ON THE
ORDER OF 2-5KTS. THE SLIGHTLY EASTWARD 23/12Z AND 24/00Z ECMWF RUNS
FOR THE LOW TRACK DO NOT LOOK LIKE SUCH AN OUTLIERS ANYMORE.
ANOTHER EXTENDED SFC TROUGH WILL LINGER ACROSS OUR AREA THROUGH
FRIDAY NIGHT...DESPITE STRONG HIGH PRESSURE PUSHING IN FROM THE
WEST. COLD AIR WILL REMAIN TRAPPED OVER NORTHEASTERN CANADA...WITH
-12C 850MB TEMPS OVER ONTARIO...-8 TO -10C ACROSS UPPER MICHIGAN
THURSDAY AFTERNOON THROUGH SATURDAY. WITH DRY HIGH PRESSURE
FILTERING IN AT THE SFC AND ALOFT...EXPECT DIMINISHING LAKE ENHANCED
PRECIPITATION NEAR LAKE SUPERIOR WITH ONLY MINOR ACCUMULATIONS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 625 AM EST SUN FEB 24 2013
EXPECT MVFR CIGS TO DOMINATE MOST OF TODAY AT ALL 3 TAF SITES WITH
LLVL MSTR TRAPPED BLO LOWERING INVRN BASE. THE ARRIVAL OF A HI PRES
RDG/LLVL ACYC FLOW MAY BRING SOME CLRG TO AT LEAST IWD AND SAW...BUT
MORE PERSISTENT UPSLOPE W WIND WL LIKELY MAINTAIN MVFR CONDITIONS AT
THE MORE EXPOSED CMX LOCATION. IF SKIES DO CLR AT IWD/SAW...FOG MAY
DVLP AT THOSE LOCATIONS TNGT AS HAPPENED IN MN UNDER THE RDG AXIS
EARLY THIS MRNG. IF THIS FOG DOES DVLP...IFR CONDITIONS ARE PSBL.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 323 AM EST SUN FEB 24 2013
THE TROUGH OF LOW PRESSURE OVER EASTERN LAKE SUPERIOR WILL SLOWLY
DISSIPATE TODAY AS HIGH PRESSURE BUILDS ACROSS THE UPPER GREAT LAKES
THROUGH MONDAY NIGHT. EXPECT LOW PRESSURE OVER THE SOUTHERN PLAINS
SUNDAY NIGHT TO TRACK NORTHEAST ACROSS THE MID MISSISSIPPI VALLEY ON
TUESDAY...BEFORE MOVING THROUGH THE LOWER GREAT LAKES WEDNESDAY INTO
WEDNESDAY NIGHT...WITH A PROLONGED PERIOD OF N-NE WINDS FROM TUESDAY
THROUGH SATURDAY. THE LOW WILL MOVE EASTWARD THROUGH THURSDAY WHILE
LEAVING YET ANOTHER TROUGH OVER LAKE SUPERIOR AS HIGH PRESSURE MOVES
EAST THROUGH MANITOBA. THE NORTH WINDS ARE EXPECTED TO INCREASE
SLIGHTLY FOR THURSDAY WITH A FEW GALE FORCE GUSTS POSSIBLE.
OTHERWISE...WINDS SHOULD REMAIN BELOW 30KTS THROUGH THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
716 AM CST SUN FEB 24 2013
.UPDATE...
UPDATED TO INCLUDE 12Z AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
MORE AND MORE...THE UPCOMING WEEK IS LOOKING DRY...AS MODELS
CONTINUE TO TREND THE BIG MIDWEEK WINTER STORM SOUTH AND EAST OF THE
MPX AREA. OTHERWISE...ONLY CONCERN TONIGHT AND AGAIN MONDAY NIGHT
WILL BE FOR REPEAT PERFORMANCES OF DENSE FOG.
OUT THE GATE THIS MORNING...MOIST BOUNDARY LAYER HAS COMBINED WITH
CLEAR SKIES AND LIGHT WINDS UNDER A SFC RIDGE ACROSS THE WRN HALF OF
MN TO GET SOME FAIRLY WIDESPREAD FOG GOING. PRETTY SOLID AREA OF 1/2
MILE OR LESS VIS FROM WEST CENTRAL UP THROUGH NW MN. FROM THE TWIN
CITIES ON EAST...STUBBORN CLOUD LAYER HAS KEPT FOG FROM FORMING. AS
FOR CURRENT ADVY...WILL TRIM COUNTIES UNDER THE INFLUENCE OF CLOUDS
OUT OF WHILE LEAVING THE REST IN PLACE...THOUGH MAY EXPAND IT ACROSS
THE REST OF SOUTH CENTRAL MN GIVEN DENSE FOG OBS AT FAIRMONT AND ST.
JAMES. BASED ON VIS FORECASTS FROM HRRR AND HOPWRF ENSEMBLE...NOT
EXPECTING ANY SIGNIFICANT IMPROVEMENTS UNTIL AFTER 15Z. IN
FACT...WHERE FOG IS MOST DENSE AROUND THE AXN AREA...MAY NOT BE
UNTIL CLOSER TO 18Z BEFORE SIGNIFICANT IMPROVEMENTS ARE MADE. THE
SLOW VIS RECOVERY IS SUPPORTED PHYSICALLY BY THE FACT THAT WE STILL
HAVE A SOMEWHAT SHALLOW LATE FEBRUARY SOLAR ANGLE AND VIRTUALLY NO
WIND IS EXPECTED WITHIN THE LOWEST 7K FT OF THE ATMO TODAY TO HELP
MIX THINGS OUT.
AS FOR FOG POTENTIAL AFTER TONIGHT...THE MPX AREA WILL REMAIN UNDER
A COL IN THE PRESSURE FIELD THROUGH MONDAY NIGHT...RESULTING IN WEAK
WINDS AND THEREFORE WEAK MECHANICAL MIXING. THE BIG QUESTION MARK
THE NEXT TWO NIGHTS WILL BE MID/UPPER LEVEL CLOUDS. TONIGHT LOOKS TO
OFFER A DECENT AMOUNT OF UPPER CLOUDS AS COMPLEX UPPER TROUGH
CURRENTLY OVER THE HIGH PLAINS MOVES OVERHEAD. SATELLITE IMAGERY
SHOWS PLENTY OF CLOUD COVER ASSOCIATED WITH THIS TROUGH AND AS THIS
PUSHES EAST DURING THE DAY...THIS SHOULD RESULT IN PLENTY OF
MID/UPPER CLOUDS TONIGHT. MONDAY NIGHT MAY FEATURE LESS CLOUD COVER
AS THE NRN STREAM WAVE SHEARS OUT. FORECAST SOUNDINGS BOTH NIGHTS
SHOW PLENTY OF LOW LEVEL MOISTURE BEING IN PLACE UNDER THE SFC RIDGE
TO SUPPORT FOG FORMATION...SO LONG AS THERE IS MINIMAL CLOUD COVER.
WITH UNCERTAINTIES IN CLOUD COVER BOTH NIGHTS...DID NOT MENTION ANY
FOG IN THE FORECAST...BUT THIS IS SOMETHING THAT WILL NEED TO BE
WATCHED CLOSELY.
WHEN IT COMES TO PRECIPITATION...NOW DOWN TO BASICALLY ONE
MODEL...THE GEM...THAT IS STILL BRINGING PRECIP TO THE AREA MID WEEK
IN ASSOCIATION WITH THE DEEP TROUGH NOW OVER THE 4-CORNERS. MODELS
ALL PRETTY SIMILAR WITH TAKING THIS UPPER LOW FROM NEW MEXICO TODAY
OVER TO THE LAKE ERIE REGION BY WEDNESDAY. THIS WILL BE QUITE THE
IMPRESSIVE SYSTEM...WITH H5 HEIGHT FALLS ON THE ORDER OF 200M AND A
WELL DEFINED H7 LOW. HEAVY SNOW SWATH STILL LOOKS LIKE A GOOD BET
FROM THE NE TX PANHANDLE UP INTO THE CHICAGO METRO AREA AND MID
MICHIGAN. FOR THE MPX AREA...WE WILL BE BATTLING RATHER STRONG DRY
AIR ADVECTION AND SUBSIDENCE ON THE NORTH SIDE OF THE SYSTEM. ONLY
REAL HOPE FOR PRECIP IN THE MPX AREA LOOKS TO COME TUESDAY NIGHT
INTO WEDNESDAY AS SFC LOW IS TRACKING FROM SRN IL TOWARD NRN OH. THE
QUESTION HERE IS HOW FAR NW DOES EXPANSIVE WRAP-AROUND PRECIP SHIELD
MAKE IT. AT THIS POINT...ONLY THE WRN OUTLIER GEM IS SHOWING PRECIP
ACROSS THE MPX CWA...WITH EVEN THE 24.03 SREF TRENDING SE WITH
PRECIP...KEEPING EVEN ERN AREAS WEST OF THE PRECIP. IF THIS TREND
CONTINUES...FUTURE SHIFTS COULD PROBABLY START PULLING OUT PRECIP
MENTION COMPLETELY. AS FOR WIND AND BLOWING SNOW POTENTIAL MID
WEEK...STILL EXPECT SPEEDS TO PICK UP TUESDAY THROUGH THURSDAY...BUT
WITH THE MAIN SFC LOW GOING AS FAR SOUTH AS IT IS...NOT EXPECTING
WINDS STRONG ENOUGH TO LEAD TO SIGNIFICANT ISSUES. LIKE TO SEE GUST
POTENTIAL OVER 30 MPH TO START SEEING SIGNIFICANT BLOWING SNOW
ISSUES...AND FORECAST SOUNDINGS FROM THE GFS KEEP EVERYTHING IN THE
20S.
FINALLY...WITH TEMPERATURES...NOT EXPECTING MUCH VARIATION OVER THE
NEXT WEEK AS 925-850 TEMPS LOOK TO STAY MORE OR LESS UNCHANGED. THIS
MEANS WE SHOULD CONTINUE TO SEE LOWER ALBEDO AREAS ACROSS CENTRAL
AND EAST CENTRAL MN INTO WRN WI WITH HIGHS MAINLY IN THE 30S...WHILE
HIGHER ALBEDO AREAS FROM WEST CENTRAL INTO SOUTH CENTRAL MN SEE HIGH
MAINLY SEE IN THE 20S. FOR LOWS...FOR THE NEXT COUPLE OF NIGHTS WITH
THE COL IN THE PRESSURE FIELD REMAINING OVERHEAD...THIS WILL LEAD TO
THE POTENTIAL FOR LOWS AROUND ZERO WHERE EVER A FEW HOURS OF
CLEARING CAN BE SEEN. OTHERWISE...LOWS WILL REMAIN ON THE MILD END
UNDER THE INFLUENCE OF CLOUDS...REMAINING UP IN THE TEENS AND 20S.
&&
.AVIATION.../12Z TAF ISSUANCE/
HIGH PRES TO SLIDE ACRS THE REGION THRU THE NEXT 24 HRS...BUT
RELATIVELY DEEP MOISTURE WITH E WINDS ALOFT WILL HELP KEEP FOG/LOW
CLOUDS IN PLACE THRU THE FIRST HALF OF THE DAY TDA. MOST OF THE
FOG THIS MRNG IS IN WRN-CENTRAL MN WITH THE LOW STRATUS IN ERN MN
INTO WRN WI...BUT CONDS WILL IMPROVE SLOWLY THRU THE MRNG HOURS.
SEVERAL HRS OF VFR CONDS XPCTD THIS AFTN INTO THIS EVE. HOWEVER...
WITH LGT WINDS AGAIN TNGT...WILL AGAIN LOOK FOR MVFR-IFR CONDS DUE
TO FOG/LOW STRATUS SETTLING IN. NO PRECIP ISSUES AND NO WINDS OVR
5-6 KT XPCTD.
KMSP...MVFR CONDS...MAINLY DUE TO VSBY...TO START ALTHOUGH MUCH
LOWER CONDS PLAGUE SMALLER TERMINALS ALL ARND MSP. HOWEVER... HAVE
BEEN OBSERVING IMPROVEMENTS AT ALL SITES SO AM NOT THINKING MSP
WOULD DROP INTO IFR FOR ANY GREAT LENGTH...IF AT ALL...THIS MRNG.
VFR CONDS THEN XPCTD FOR MUCH OF THE DAY INTO THIS EVENING. CONDS
THEN DROP AGAIN TNGT...STARTING ARND MIDNIGHT...HITTING MVFR RANGE
WITH A FEW OBS OF IFR POSSIBLE.
/OUTLOOK FOR KMSP/
MON...MVFR POSSIBLE IN THE MORNING...OTHERWISE VFR. WINDS ENE 5KTS.
TUE...MVFR WITH IFR AND -SN POSSIBLE. WINDS N 10G15KTS.
WED...MVFR POSSIBLE IN THE MORNING...OTHERWISE VFR. WINDS NNE 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FREEZING FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR BLUE EARTH-
BROWN-CARVER-CHIPPEWA-DOUGLAS-FARIBAULT-FREEBORN-KANDIYOHI-
LE SUEUR-MARTIN-MCLEOD-MEEKER-NICOLLET-POPE-RENVILLE-RICE-
SCOTT-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT-TODD-WASECA-
WATONWAN-WRIGHT.
WI...NONE.
&&
$$
JPC
AREA FORECAST DISCUSSION
NWS BUFFALO NY
957 AM EST SUN FEB 24 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL BRING OCCASIONAL SNOW SHOWERS THROUGH THE
AFTERNOON WITH ONLY VERY LIGHT ACCUMULATIONS. EXPECT A DRY DAY ON
MONDAY AS HIGH PRESSURE CRESTS INTO THE EASTERN GREAT LAKES REGION.
A LARGE AREA OF LOW PRESSURE WILL APPROACH THE REGION LATE TUESDAY
WITH UNSETTLED WEATHER LASTING FROM TUESDAY NIGHT THROUGH THE END OF
THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE ANALYSIS THIS MORNING SHOWING A WEAK LOW OVER SOUTHERN
QUEBEC WITH SECONDARY COASTAL CYCLOGENESIS UNDERWAY JUST SOUTHEAST
OF CAPE COD. A SHARP MID LEVEL TROUGH EVIDENT IN WATER VAPOR IMAGERY
AND OBJECTIVE RUC ANALYSIS OVER SOUTHERN ONTARIO AT 15Z WILL SWING
EAST ACROSS THE REGION FROM LATE MORNING THROUGH MID AFTERNOON AND
CONTINUE TO PROVIDE A PERIOD OF LARGE SCALE ASCENT IN THE DPVA
REGION AHEAD OF THE TROUGH.
RADAR IMAGERY SHOWING RATHER WIDESPREAD LIGHT SNOW SHOWERS ACROSS
WESTERN NY AND ALSO BEGINNING TO ENTER THE EASTERN LAKE ONTARIO
REGION. BY AFTERNOON AS THE COLD CORE ALOFT CROSSES THE REGION...
850MB TEMPS DROP TO AROUND -11C. THIS MAY BE JUST COLD ENOUGH TO
SUPPORT SOME VERY LIMITED LAKE ENHANCEMENT. THIS COMBINED WITH
UPSLOPE FLOW MAY PRODUCE UP TO AN INCH OF ACCUMULATION ON THE HILLS
OF THE SOUTHERN TIER AND ALSO ACROSS THE TUG HILL REGION. ELSEWHERE
ONLY A LIGHT COATING OF ACCUMULATION IS EXPECTED...AND WITH THE NOW
STRONGER LATE FEBRUARY SUN ANGLE EXPECT MOST ROADS TO JUST REMAIN
WET.
HIGHS TODAY WILL BE IN THE UPPER 20S ACROSS THE HIGHER TERRAIN OF
THE FORECAST AREA IN THE SOUTHERN TIER AND TUG HILL...WITH LOWER 30S
ACROSS THE LOWER ELEVATIONS OF THE LAKE PLAINS AND CLOSE TO THE LAKE
ERIE SHORE. LOWS TONIGHT WILL BE IN THE LOWER 20S AWAY FROM THE
LAKES...AND IN THE MID TO UPPER 20S ALONG AND DOWNWIND OF THE LAKES
WHERE CLOUDS WILL ALSO LINGER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AT THE START OF THE PERIOD WE WILL SEE THE UPPER TROUGH SHIFTING
OFF TO OUR EAST AS THE AREA COMES UNDER THE INCREASING INFLUENCE
OF UPPER RIDGING AND HIGH PRESSURE...PUSHING EAST FROM THE GREAT
LAKES AND OHIO VALLEY. THIS WILL SUPPORT A WEAKENING TO THE
NORTHWESTERLY FLOW AND A LOWERING OF OVER-LAKE INVERSION HEIGHTS.
THIS WILL ACT TO SUPPRESS ANY LINGERING LAKE SNOW SHOWERS
SOUTHEAST OF LAKE ONTARIO. BUFR SOUNDINGS SHOWING CONSIDERABLE LOW
LEVEL MOISTURE UNDERNEATH SUBSIDENCE INVERSION AND CONSIDERING
LIGHT NORTHERLY FLOW DEVELOPING...IT MAY BE TAKE AWHILE BEFORE
CLOUDS CAN SCATTER OUT. TEMPERATURES WILL RUN NEAR NORMAL WITH
HIGHS IN THE LOWER TO MID 30S.
MONDAY NIGHT...THE CENTER OF THE SURFACE HIGH WILL MOVE OVERHEAD
THEN SHIFT EAST TO NEW ENGLAND WITH A BETTER CHANCE TO SEE
CLEARING SKIES...ALTHOUGH HIGH CLOUDS MAY BEGIN TO SLIDE OVERHEAD
ACROSS THE WEST AHEAD OF THE NEXT STORM SYSTEM.
THE TUESDAY AND TUESDAY NIGHT TIME FRAME CONTINUES TO BE THE MAIN
FORECAST CHALLENGE...AS THE COMPACT UPPER LEVEL SYSTEM EJECTS INTO
THE OHIO VALLEY. FOR THIS PACKAGE...WE WILL LEAN TOWARD TO THE
OPERATIONAL ECMWF RUN WITH INCREASING SUPPORT FROM THE GFS. THE
SYSTEM WILL BE UNDERGOING AN OCCLUSION PROCESS DURING THIS TIME
FRAME. THIS WEAKENING PROCESS WOULD OFTEN SIGNAL THAT THE
PRECIPITATION SHIELD ON THE NORTHERN SIDE OF THE UPPER LOW WILL
BE WANING...HOWEVER A WELL DEFINED CONVEYOR OF MOISTURE FROM THE
ATLANTIC WILL BE WORKING INTO THE NORTHERN OR COLD SIDE OF THE
SYSTEM. MID TROPOSPHERIC DEFORMATION ALONG THE NORTHERN FLANK OF
THE UPPER LOW IS FORECAST TO BE EXCELLENT WITHIN A HIGHLY
DIFFLUENT UPPER FLOW. THE STRONG DYNAMIC SUPPORT IS EXPECTED TO
LIFT ACROSS WESTERN AND CENTRAL NEW YORK LATE TUESDAY AND TUESDAY
NIGHT DEVELOPING WIDESPREAD PRECIPITATION. THERMAL PROFILES
SUGGESTING PRECIPITATION WILL LIKELY START AS A RAIN DUE TO THE
LATE DAYTIME ARRIVAL...ALTHOUGH A WINTRY MIX COULD BECOME
PROBLEMATIC ALONG THE SOUTHERN TIER. CONCERNS ARISE TUESDAY NIGHT
AS PRECIPITATION MAY FALL AT SUFFICIENT RATES TO CAUSE SIGNIFICANT
DIABATIC COOLING OF LOWER LAYERS ALLOWING FOR A GREATER RISK FOR
SNOW. HEAVY SNOW NOT TOTALLY OUT OF THE QUESTION FOR SOME AREAS AS
A WELL DEFINED TROWAL FEATURE EVOLVES. HOWEVER...TOP CIPS ANALOGS
WERE SHOWING GREATEST SUPPORT FOR SNOWFALL AMOUNTS TO REMAIN
BELOW WARNING CRITERIA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A BUILDING BLOCKING PATTERN CURRENTLY TAKING SHAPE OVER THE NORTH
ATLANTIC CAN BE SEEN WITHIN THE ECMWF 500MB HEMISPHERIC PLOT AND
CURRENT NEGATIVE PHASE OF THE NAO WHICH WILL MAKE FOR A SLOW-TO-MOVE
WEATHER PATTERN AT LEAST FROM MIDWEEK INTO THE WEEKEND. MODEL
ENSEMBLE FORECASTS FOR THE NAO INDEX SHOW THIS COULD PERSIST INTO
EARLY MARCH AS WELL. THE STORM SYSTEM WHICH WILL BE NEAR THE
FORECAST AREA ON WEDNESDAY WILL CONTINUE TO BRING CLOUDS AND
DIURNALLY INFLUENCED PRECIPITATION. AFTER THE INITIAL WARM FRONTAL
FORCED SLUG OF PRECIP PUSHES THROUGH TUESDAY NIGHT WE WILL SEE
MAINLY SCATTERED SHOWER ACTIVITY AS THE SYSTEM OCCLUDES TO OUR WEST
WEDNESDAY AND WEDNESDAY NIGHT WHICH THE 12Z GFS AND ECMWF AGREE
UPON.
MODELS SHOW THE SYSTEM WILL GET NUDGED EASTWARD THROUGH THURSDAY
WHERE A SLUG OF MOISTURE BENEATH THE UPPER LOW WILL LIKELY AGAIN
BRING RAIN AND SNOW ACROSS THE FORECAST AREA. P-TYPE WILL BE
DIURNALLY INFLUENCED AS DAYTIME TEMPS WILL RISE ABOVE FREEZING IN
MANY SPOTS DURING THE DAY WITH RAIN OCCURRING AND OVERNIGHT TEMPS
FALLING BACK TO NEAR OR BELOW FREEZING WHERE SNOW CAN BE EXPECTED.
FRIDAY AND SATURDAY WITH THE LOW NOW EAST OF THE LOWER LAKES SOME
COLDER AIR MOVES IN AND WITH LINGERING TROUGHINESS ALOFT WE KEPT A
CHANCE OF SNOW IN THE FORECAST. BY SATURDAY WE LOOK TO RETURN TO
BELOW NORMAL WHERE HIGHS MAY NOT BREAK ABOVE FREEZING.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
UPPER CUT OFF LOW TO CROSS THE REGION TODAY WITH MAINLY MVFR
CIGS/VSBY IN LIGHT SNOW AND OCCASIONAL BRIEF DROPS TO IFR VSBY IN
ANY STEADIER SNOW SHOWERS.
CONDITIONS WILL IMPROVE TO VFR 00Z-03Z AS DRYING ALOFT ASSOCIATED
WITH HIGH PRESSURE MOVING INTO THE REGION...SOME MVFR CIGS FOR
SOUTHERN TIER AND KROC-KSYR CORRIDOR.
OUTLOOK...
TONIGHT...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
MONDAY...VFR.
TUESDAY THROUGH THURSDAY...MVFR WITH A CHANCE OF RAIN/SNOW.
&&
.MARINE...
A WEST WIND OVER LAKE ERIE UNDER CYCLONIC FLOW AND COLD AIR
ADVECTION ALOFT WILL STRENGTHEN TOWARDS 15 TO 20 KNOTS. A SMALL
CRAFT ADVISORY FOR LAKE ERIE WILL BE IN EFFECT THROUGH THE EARLY
EVENING. WINDS AND WAVES WILL ALSO CREATE SMALL CRAFT CONDITIONS ON
LAKE ONTARIO FROM SODUS BAY TO MEXICO BAY AND NORTH TO HENDERSON
BAY. THESE CONDITIONS WILL DEVELOP AROUND MID DAY AND PERSIST
THROUGH THE EVENING.
ON MONDAY AN AREA OF HIGH PRESSURE WILL CROSS THE LAKE WITH MINIMAL
WINDS AND WAVES ON THE LAKES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
LOZ044-045.
&&
$$
SYNOPSIS...HITCHCOCK/WCH
NEAR TERM...HITCHCOCK/WCH
SHORT TERM...TMA
LONG TERM...SMITH
AVIATION...HITCHCOCK/WCH
MARINE...WCH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
645 AM EST SUN FEB 24 2013
.SYNOPSIS...
WEAK LOW PRESSURE MOVES AWAY FROM THE CAROLINA COAST AS HIGH
PRESSURE BUILDS INTO THE AREA TODAY. ANOTHER STORM SYSTEM MOVES INTO
THE REGION BY TUESDAY. THE LOW PRESSURE SYSTEM WILL INFLUENCE THE
WEATHER OF THE REGION INTO LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM SUNDAY...
WHILE THE AXIS OF DEEPEST MOISTURE HAS FOR THE MOST PART SHIFTED
EAST AND DRIZZLE HAS BEEN MORE COMMON AROUND THE CWA ...A FEW
SHOWERS HAVE POPPED UP DURING THE PAST HOUR IN RESPONSE TO THE
APPROACHING UPPER TROUGH AXIS. THE HRRR HAS HAD A DECENT HANDLE ON
THIS EXPANDING PRECIP...AND WILL BE USED TO UPDATE THE NEAR TERM
FORECAST. WITH CONTINUED DRYING ALOFT COINCIDENT WITH THE TROUGH
PASSAGE...WILL BRING POPS TO AN END OVER THE NORTHERN COASTAL PLAIN
BY 12Z.
THE OTHER MAIN CONCERN IN THE NEAR TERM IS THE POTENTIAL FOR FOG.
THE BACK EDGE OF THE MAIN MID/HIGH CLOUD DECK HAS CLEARED THE
WESTERN PIEDMONT...BUT VISIBILITIES HAVE BEEN SLOW TO FALL BELOW 2SM
AT MOST SITES. A SECONDARY COLD FRONT IS WORKING ITS WAY ACROSS THE
MOUNTAINS...BUT AMPLE LOW LEVEL MOISTURE IN THE RESIDUAL WEDGE
AIRMASS WOULD SUPPORT DENSE FOG...MAINLY WEST OF RALEIGH. WE
WILL CONTINUE TO MONITOR THE OBSERVING SITES...BUT A DENSE FOG
ADVISORY MAY BE NEEDED BY 09-10Z.
LATER THIS MORNING..SKIES WILL CLEAR AND DRIER AIR WILL WORKS ITS
WAY ACROSS THE CWA. MODELS SHOW HE BETTER POST FRONTAL COLD
ADVECTION HOLDING OFF UNTIL AFTER 21Z...AND WITH FULL
INSOLATION...HIGHS SHOULD REBOUND RATHER NICELY. 1000-850MB
THICKNESSES REACHING THE 1330S THROUGH EARLY AFTERNOON SUPPORT HIGHS
IN THE UPPER 50S NORTH TO LOW/MID 60S SOUTH. HIGH PRESSURE WILL
BUILD INTO THE AREA TONIGHT...WITH THE RIDGE AXIS AND BEST POTENTIAL
FOR DECOUPLING ACROSS THE NORTHERN PIEDMONT/COASTAL PLAIN. LOWS
SHOULD FALL TO THE LOW TO MID 30S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
AS OF 305 AM SUNDAY...
MONDAY AND MONDAY NIGHT...
COLD HIGH PRESSURE WILL SETTLE OVER NEW ENGLAND ON MONDAY...RIDGING
SOUTH INTO THE CAROLINAS. A 15-20M DROP IN 1000-850MB THICKNESSES
FROM SUNDAY TO MONDAY SUGGESTS HIGHS WILL STRUGGLE TO CLIMB OUT OF
THE LOW TO MID 50S...EVEN WITH A FAIR AMOUNT OF SUN THROUGH MIDDAY.
HIGH CLOUDS WILL BEGIN TO POUR INTO THE AREA MONDAY AFTERNOON AHEAD
OF A LOW PRESSURE SYSTEM EJECTING OUT OF THE SOUTHERN PLAINS. WARM
ADVECTION AND ISENTROPIC LIFT WILL INCREASE RAPIDLY MONDAY NIGHT
AHEAD OF A STRONG LOW LEVEL JET AND SURFACE-850MB WARM FRONT
EMANATING OFF OF THE GULF COAST REGION. WHILE FORECAST SOUNDINGS
SHOW QUITE A BIT OF DRY AIR BELOW 10K FT...STRENGTHENING UPPER
DIVERGENCE AND A BACKED LOW-LEVEL ATLANTIC MOISTURE FEED ASSOCIATED
WITH AN APPROACHING UPPER JET SHOULD QUICKLY OVERWHELM THE
AIRMASS...LEADING TO POPS RANGING FROM CATEGORICAL IN THE SOUTHWEST
TO LIKELY IN THE NORTHEAST AFTER MIDNIGHT. LOWS IN THE MID 30S TO
LOWER 40S. -SMITH
TUESDAY AND TUESDAY NIGHT...
DIFFLUENCE ALOFT EXISTS IN EARNEST TUESDAY AS THE UPPER LOW LIFTS TO
THE NORTHWEST OF THE STATE. GOOD 850MB THETA-E ADVECTION IS IN
PLACE...AND BY 18Z TUESDAY...PRECIPITABLE WATER VALUES ARE CLOSING
IN ON 1.5 INCHES...NEAR THE MAXIMUM OF THE CLIMATOLOGICAL ENVELOPE
FOR LATE FEBRUARY IN CENTRAL NORTH CAROLINA. DEEP AND BROAD SURFACE
LOW PRESSURE IN CONJUNCTION WITH MOISTURE AND LIFT SUGGESTS
WIDESPREAD RAIN IN A WEDGED AIR MASS INTO TUESDAY AFTERNOON...AND
SOME OF THE RAIN COULD BE LOCALLY HEAVY WITH...CURRENTLY...THE
HEAVIEST RAIN MOST LIKELY FOCUSED ALONG AND EAST OF U.S. 1 WHERE
850MB THETA-E RIDGING IS GREATEST DURING THE DAY...AND WHERE 850MB
CONVERGENCE LINGERS LONGEST. BASIN AVERAGE RAINFALL FOR THIS
FORECAST WILL BE AROUND 0.75 INCH TOWARD THE TRIAD...AND AROUND 1.5
INCHES SOUTH OF A LINE FROM KMEB TO KGSB...INCLUDING KFAY.
WHILE THE NAM FORECASTS A SURFACE LOW FARTHER WEST IN CENTRAL NORTH
CAROLINA TOWARD 00Z WEDNESDAY...THE GFS FORECASTS THE TRIPLE POINT
OF LOW PRESSURE SKIRTING THE FAR SOUTHEAST OF CENTRAL NORTH
CAROLINA...MORE TOWARD KFAY...KCTZ...AND KGSB. BUFR SOUNDINGS FROM
BOTH THE NAM AND THE GFS SHOW THE WEDGE TO BE FAIRLY STRONG AND
PROBABLY DIFFICULT TO DISLODGE...AND INSTABILITY FOR NOW APPEARS TO
BE LIMITED IN CENTRAL NORTH CAROLINA FOR THIS EVENT. DURING TUESDAY
AFTERNOON...THE GFS FORECASTS MIXED LAYER CAPE APPROACHING 700J/KG
OVER PARTS OF EASTERN SOUTH CAROLINA WHICH DIMINISHES AS THE TRIPLE
POINT MOVES NORTHEAST INTO THE WEDGE...SKIRTING THE FAR SOUTHERN
COASTAL PLAIN WITH VALUES UNDER 500J/KG AND LIFTED INDICES JUST
BELOW ZERO. IT SHOULD BE A NARROW WINDOW FOR ANY POTENTIAL OF STRONG
THUNDER IN THE SOUTHEAST...NEEDING TO BE COINCIDENT WITH ENOUGH
WARMTH IN VICINITY OF THE TRIPLE POINT AS THE DRY SLOT MOVES IN. GFS
BUFR SOUNDINGS SHOW THE POTENTIAL FOR STRONGER STORMS IS GREATER
TOWARD THE COAST...WHERE THE 850MB AND 925MB WINDS...ALONG WITH
1000-500MB LAPSE RATES...WILL BE BETTER LATE IN THE DAY. CONSIDERING
A SLIGHT CHANCE OF THUNDER ONLY FOR THE FAR SOUTHEAST PART OF
CENTRAL NORTH CAROLINA AS OF THIS WRITING NEAR THE CURRENTLY
EXPECTED TRACK OF THE SURFACE LOW COINCIDENT WITH THE HIGHEST
AFTERNOON TEMPERATURES IN CENTRAL NORTH CAROLINA.
IN TERMS OF TEMPERATURES...THERE SHOULD BE A STRONG GRADIENT IN
HIGHS TUESDAY...STRUGGLING TO RISE THROUGH THE 40S IN THE TRIAD...
TO THE LOWER OR EVEN POSSIBLY THE MID 60S IN THE FAR SOUTHEAST. THE
MORNING BUFR SOUNDING TOWARD KGSO TUESDAY SHOWS A PORTION OF THE
TEMPERATURE PROFILE BELOW ZERO ALOFT...BUT PARTIAL THICKNESSES NOTE
THE PRECIPITATION TYPE SHOULD BE ALL LIQUID. THE DRY SLOT AND
DIMINISHING MOISTURE OVERALL PROVIDE FOR CHANCES FOR PRECIPITATION
LOWERING QUICKLY FROM LATE TUESDAY AFTERNOON THROUGH TUESDAY
EVENING...BUT THE NAM MAY BE ON TO SOMETHING WITH ITS BUFR SOUNDINGS
IN SHOWING LOW-LEVEL MOISTURE AND CLOUDS SLOW TO ERODE IN AREAS WEST
OF U.S. 1 AND PARTICULARLY TOWARD THE TRIAD. WILL TREND TOWARD
WARMER OVERNIGHT LOWS TUESDAY NIGHT...MOSTLY IN THE 40S. -DJF
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 305 AM SUNDAY...
DURING THE MIDDLE AND END OF THE WEEK...THE LONG-TERM GUIDANCE IS
FAIRLY CONSISTENT IN FORECASTING AN UPPER LOW OVER OR NEAR THE LOWER
GREAT LAKES...GRADUALLY MIGRATING EAST. CONSISTENCY IS ALSO APPARENT
IN THE GUIDANCE...WITH SUBTLE TIMING DIFFERENCES...IN FORECASTING AT
LEAST A MODERATE MID-LEVEL SHORTWAVE MOVING ACROSS THE STATE
SOMETIME WEDNESDAY INTO WEDNESDAY EVENING ACCOMPANIED BY A SURFACE
TROUGH OR SECONDARY COLD FRONT. FROM THERE...A BROAD UPPER TROUGH
REMAINS OVER CENTRAL NORTH CAROLINA THROUGH THE END OF THIS CURRENT
LONG-TERM PERIOD...WITH MAINLY NORTHWEST...CONFLUENT FLOW ALOFT
DEVELOPING THURSDAY...AND THE TROUGH AXIS BUILDING BACK SOUTHWEST
AND INTRODUCING SOUTHWEST FLOW ALOFT ACROSS CENTRAL NORTH CAROLINA
BY THE END OF THE WORK WEEK. MUCH OF THE MEASURABLE GUIDANCE QPF IS
AWAY FROM CENTRAL NORTH CAROLINA TO THE NORTHWEST AND NORTH...
CREEPING CLOSEST WITH THE APPROACH AND PASSAGE OF BOTH THE STRONGER
MID-LEVEL SHORTWAVE AND THE SURFACE TROUGH WEDNESDAY INTO WEDNESDAY
EVENING.
THE 00Z GFS BUFR SOUNDING FOR KGSO NEAR 00Z THURSDAY IS INTERESTING
IN ITS STEEP LAPSE RATES AND POTENTIAL INSTABILITY INTO THE ICE
NUCLEATION REGION...AND DESPITE THE STABILITY OF THE ECMWF COARSE
MODEL SOUNDINGS FOR KGSO AND ELSEWHERE IN CENTRAL NORTH CAROLINA...
THE STRENGTH OF THE MID-LEVEL WAVE AHEAD OF THE MID-LEVEL TROUGH AND
ITS HEIGHT FALLS...ACCOMPANIED BY THE SURFACE FEATURE...WOULD SEEM
TO WARRANT AT LEAST A SLIGHT CHANCE OF A SHOWER WEDNESDAY AFTERNOON
INTO WEDNESDAY EVENING NORTH OF U.S. 64 AND ESPECIALLY FROM
THE TRIAD TOWARD THE VIRGINIA BORDER RELATIVE TO THE REST OF THE
AREA. PARTIAL THICKNESSES ARE SUPPORTIVE OF ALL LIQUID AT THAT TIME.
THE SAME SOUNDINGS ALSO SHOW SOME MID-LEVEL MOISTURE PRESENT LATE
WEDNESDAY NIGHT INTO THURSDAY MORNING...AND AS THE TROUGH AXIS
ROTATES THROUGH...THERE COULD BE A FEW FLURRIES THEN WITH NO
ANTICIPATED IMPACT. FOR THIS FORECAST...WILL INTRODUCE A SLIGHT
CHANCE OF RAIN SHOWERS WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING
NORTH...WITH DRY CONDITIONS ELSEWHERE AND THEREAFTER FOR NOW.
WEDNESDAY AND THURSDAY SHOULD BE BREEZY DAYS IN A TIGHT SURFACE
GRADIENT BOTH AHEAD OF...AND ESPECIALLY BEHIND...THE SURFACE TROUGH
AND THICKNESS AND HEIGHT FALLS. FRIDAY SHOULD FEATURE SOMEWHAT
BREEZY CONDITIONS EARLY WITH MIXING BEFORE THE GRADIENT SLACKENS AS
LOW PRESSURE RETREATS OFFSHORE OF NEW ENGLAND AND THE MID-ATLANTIC.
THERE IS ALSO GOOD CONFIDENCE IN BELOW NORMAL HIGHS FOR THE END OF
THE WEEK INTO THE WEEKEND...LIKELY IN THE RANGE OF FIVE TO AROUND
TEN DEGREES BELOW WHAT SHOULD BE MID 50S TO AROUND 60. THE CONSENSUS
OF THE TEMPERATURE GUIDANCE...AND THE BLEND OF 1000-850MB
THICKNESSES BETWEEN THE GFS AND THE ECMWF...ARE BELOW MEX MOS
THURSDAY THROUGH SATURDAY. -DJF
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 645 AM SUNDAY...
LOW CLOUDS AND LIMITED VSBYS CONTINUE ACROSS CENTRAL NC THIS MORNING
AS A MURKY WEDGE AIRMASS LINGERS EAST OF THE MOUNTAINS. THE
DEPARTURE OF MID/HIGH CLOUDS HAS LEAD TO REDUCED VSBYS AT MANY
TERMINALS...THE LOWEST BEING IN THE TRIAD AT KGSO/KINT WHERE VSBYS
ARE LIFR. EAST OF THE TRIAD...VSBYS ARE ARE NOT AS LOW...BUT
CEILINGS ARE AT LIFR LEVELS. A SECONDARY COLD FRONT AND DRIER AIR
ARE BEGINNING TO PUSH EAST OF THE MOUNTAINS....AND VSBYS/CEILINGS
WILL BEGIN TO IMPROVE FROM WEST TO EAST BETWEEN 12Z AND 16Z. VFR
CONDITIONS ARE THEN EXPECTED FOR THE REMAINDER OF THE TAF
PERIOD...WITH NORTHWESTERLY WINDS TURNING TO NORTHEASTERLY OVERNIGHT
AS HIGH PRESSURE BUILDS INTO CENTRAL NC FROM THE NORTH.
OUTLOOK...
VFR CONDITIONS WILL CONTINUE TONIGHT AND MONDAY. A STORM
SYSTEM MOVING INTO THE REGION MONDAY NIGHT WILL BRING SUB-VFR
CONDITIONS WITH THE POTENTIAL FOR ISOLATED THUNDERSTORMS (KFAY/KRWI)
AND HEAVY RAIN TUESDAY. VFR CONDITIONS ARE THEN EXPECTED TO RETURN
BY TUESDAY NIGHT AND PERSIST THROUGH THE END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...SMITH
SHORT TERM...SMITH/DJF
LONG TERM...SMITH
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
420 AM CST SUN FEB 24 2013
.SHORT TERM...
CHALLENGE FOR THE FORECAST INCLUDES FOG THIS MORNING AND ITS AFFECT
TODAY ON TEMPS IN NW MN. OTHERWISE TEMPS AND CLOUD THE MAIN
CHALLENGE FOR THE FIRST PART OF THE WEEK. MODELS IN GOOD AGREEMENT
AND USED A BLEND FOR THE FORECAST PACKAGE.
HAVE INHERITED FOG ADVSY AND NEED TO EXPEND NORTH AS OBS AT CRK AND
HCO ARE QUARTER MILE. HRRR SHOWS LOW VSBYS THRU 18Z SO WILL EXTEND IN
TIME ALSO. STRATUS DECK WILL LIFT AS 925 WINDS INCREASE AND IMPROVE
MIXING THROUGH THE MORNING HOURS SIMILAR TO SATURDAY MORNING. WEAK
SFC LOW IS EXPECTED TO CONTINUE TO MOVE ACROSS ND TODAY AND SLOWLY
WEAKEN AS LIGHT SNOW COVERAGE DIMINISHES. KEPT THE CHC POPS IN THE
DVL BSN THRU NOON THEN WENT FLURRIES FOR THIS AFTERNOON.
MON AND TUE ARE DRY WITH CONCERN BEING CLOUD COVER AND ITS EFFECTS
ON TEMPS. 500MB SPLIT FLOW WITH SOUTHERN PLAINS CUTOFF STORM SYSTEM
AND RIDGING BUILDING INTO THE NORTHERN PLAINS WILL GIVE MORE SUN
THAN CLOUDS WITH 925 TEMPS INCREASING TO NEAR 0 BY 00Z TUE WILL GIVE
ABOVE NORMAL TEMPS TO THE AREA.
.LONG TERM (WEDNESDAY-SATURDAY)...
MODELS AGREE THAT AN UPPER RIDGE
WILL BUILD ACROSS THE WESTERN CONUS THROUGH THE PERIOD. THIS WILL
PLACE A SFC RIDGE ACROSS THE REGION AND LEAD TO DRY WEATHER.
TEMPERATURES WILL BE NEAR NORMAL.
&&
.AVIATION...
ANOTHER MORNING OF FG ACROSS ALL TAF SITES EXCEPT DVL. INTERMITTENT 1/4
VSBYS TO LAST THROUGH EARLY MORNING WITH IFR CIGS/VSBYS TO IMPROVE
LATE MORNING TO EARLY AFTN.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FREEZING FOG ADVISORY UNTIL NOON CST TODAY FOR NDZ053.
MN...FREEZING FOG ADVISORY UNTIL NOON CST TODAY FOR MNZ001>009-
013>017-022>024-027>032-040.
&&
$$
JK/TG
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1041 AM EST SUN FEB 24 2013
.SYNOPSIS...
AN UPPER LEVEL LOW OVER THE GREAT LAKES WILL SLIDE EAST ACROSS
UPSTATE NEW YORK TODAY. A RIDGE OF HIGH PRESSURE WILL BUILD OVER
PENNSYLVANIA ON MONDAY. A STORM SYSTEM OVER THE PLAINS WILL TRACK
NORTHEAST INTO PENNSYLVANIA ON TUESDAY. THE PARENT UPPER LOW WILL
REMAIN OVER THE NORTHEAST CONUS THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED PACKAGE. CURRENT FCST GOOD...SOME SNOW SHOWERS WORKING
IN LATER ACROSS THE NORTH...SOME SUN EARLY THIS MORNING.
EARLIER DISCUSSION BELOW.
DRIER WESTERLY FLOW WORKING INTO CENTRAL PA EARLY THIS AM BEHIND
OCCLUDED FRONT. HOWEVER...ABUNDANT LOW LVL MOISTURE AND A CALM
WIND AHEAD OF THIS BOUNDARY CONTINUES TO RESULT IN AREAS OF FOG
ACROSS THE SUSQ VALLEY AT 11Z. LATEST 3KM HRRR SUGGESTS FOG WILL
LIFT ACROSS THE EASTERN ZONES BY ARND 13Z...AS DRIER AIR ARRIVES.
FOCUS THEN SHIFTS TOWARD UPPER LOW SLIDING EAST FROM THE GRT LKS.
LG SCALE FORCING AHEAD OF THIS FEATURE SHOULD SUPPORT SCT -SHSN
ACROSS THE W MTNS LATER TODAY...WHICH WILL LIKELY DUST THE GROUND
OVER THE HIGHER TERRAIN.
CAA AND PLENTY OF STRATO-CU SHOULD KEEP TEMPS FROM RISING MUCH
TODAY...THE EXCEPTION BEING THE LOWER SUSQ VALLEY...WHERE
DRYING/DOWNSLOPING FLOW SHOULD YIELD PTSUNNY SKIES AND TEMPS
REACHING THE M40S. A TIGHTENING PRES GRADIENT BTWN HIGH PRES OVR
THE MIDWEST AND INTENSIFYING LOW SOUTH OF NEW ENG WILL RESULT IN
AN INCREASINGLY GUSTY WNW WIND ACROSS CENTRAL PA TODAY. BUFKIT MDL
SOUNDINGS INDICATE THERE WILL BE GUSTS ARND 25KTS BY MID AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
SCT SNOW SHOWERS ACROSS THE NW MTNS SHOULD TAPER OFF THIS
EVENING...AS UPPER LOW LIFTS OUT AND INVERSION HGTS FALL. EXPECT A
GENERAL CLEARING TREND TONIGHT...AS SFC HIGH BUILDS TOWARD PA FROM
THE MIDWEST. HOWEVER...MDL SOUNDINGS INDICATE LOW LVL MOISTURE
TRAPPED BENEATH INVERSION WILL REMAIN BANKED AGAINST THE NW MTNS
THRU MUCH OF THE NIGHT.
HIGH PRES SHOULD PROVIDE MOST OF THE REGION WITH SUNNY SKIES AND
LGT WINDS MONDAY WITH TEMPS NEAR SEASONAL LEVELS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ALL MED RANGE GUIDANCE INDICATING UPPER LOW OVR THE MISS VALLEY
WILL LIFT NE TOWARD PA ON TUESDAY...PROVIDING INCREASING
CONFIDENCE IN A FAIRLY SIGNIFICANT PRECIP EVENT FOR PA WITH GEFS
MEAN QPF BTWN 0.5 AND 1 INCH. BOTH ECMWF ENSEMBLE MEAN AND GEFS MEAN
SOLUTIONS TRACK A PRIMARY SFC LOW TO OUR WEST WITH A SECONDARY
LIFTING THRU EASTERN PA. THIS SCENARIO WOULD LIKELY RESULT IN SOME
WARMER AIR WORKING IN ALOFT...RESULTING IN MIXED PRECIP TYPES.
ECMWF ENS MEAN 850 TEMPS SUPPORT THE BEST CHC OF WINTRY PRECIP OVR
THE N MTNS WITH RAIN MOST LIKELY IN THE SE.
THE BULK OF THE PRECIP SHOULD BE OVER BY WED...AS SERLY LL JET AND
PLUME OF ANOMALOUS PWATS LIFTS NORTH OF PA. HOWEVER...UNSETTLED/COOL
WX SEEMS LIKELY THRU THE END OF NEXT WEEK WITH MED RANGE MDL DATA
ALL KEEPING UPPER LOW IN THE VICINITY OF PA. ALTHOUGH AIR MASS
DOESN/T LOOK INITIALLY COLD ENOUGH FOR LAKE EFFECT...A
DEEP...MOIST NWRLY FLOW SHOULD YIELD PERSISTENT UPSLOPE SNOW
SHOWERS ACROSS THE W MTNS WED-FRI. LIGHT ACCUMS SEEM PROBABLE ESP
AT NIGHT. DAYTIME TEMPS WED-THU SHOULD GET ABV FREEZING EVERYWHERE
BASED ON ECMWF ENS MEAN 8H TEMPS.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
FRONT HAS CROSSED CENTRAL PENNSYLVANIA...AND SHIFTED WINDS TO THE
NORTHWEST. IT WILL REMAIN BREEZY THIS AFTERNOON...WITH 10 TO 20
KNOT WINDS COMMON.
WITH THE FRONTAL PASSAGE...MOST FOG HAS NOW LIFTED. SOME RESIDUAL
LOWER STRATUS IN THE EAST SHOULD BE GONE IN THE NEXT HOUR OR TWO
AS DRIER LOW LEVEL AIR MOVES IN. AT THE SAME TIME...WNW FLOW WILL
INDUCE TYPICAL MOUNTAIN STRATUS AND SNOW SHOWERS ACROSS THE
WESTERN AND NORTHERN MOUNTAINS. STILL EXPECTING CENTRAL AREAS
/KAOO...KUNV/ TO HAVE CIGS LIFT TO LOW VFR CONDITIONS BY 17Z OR SO.
KJST AND KBFD WILL LIKELY REMAIN IN MVFR CONDITIONS ALL DAY...WITH
KBFD OCCASIONALLY FALLING INTO IFR RANGE AT TIMES IN SNOW SHOWERS.
VFR CONDITIONS FOR MONDAY AS HIGH PRESSURE MOVES ACROSS THE
REGION.
ANOTHER SIGNIFICANT WEATHER SYSTEM WILL BRING LOWERING CONDITIONS
AND MIXED PRECIPITATION TO CENTRAL PENNSYLVANIA BEGINNING
TUESDAY...LASTING INTO WEDNESDAY.
OUTLOOK...
MON...MAINLY VFR.
TUE...DETERIORATING CONDITIONS FROM SW TO NE. MVFR TO IFR.
WED...CONTINUED MIXED PRECIPITATION...MVFR TO IFR.
THU...CONTINUING RAIN AND SNOW SHOWERS...REDUCED CIGS AND VSBYS
ESPECIALLY WEST AND CENTRAL.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD/MARTIN
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...JUNG/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
931 AM EST SUN FEB 24 2013
.SYNOPSIS...
AN UPPER LEVEL LOW OVER THE GREAT LAKES WILL SLIDE EAST ACROSS
UPSTATE NEW YORK TODAY. A RIDGE OF HIGH PRESSURE WILL BUILD OVER
PENNSYLVANIA ON MONDAY. A STORM SYSTEM OVER THE PLAINS WILL TRACK
NORTHEAST INTO PENNSYLVANIA ON TUESDAY. THE PARENT UPPER LOW WILL
REMAIN OVER THE NORTHEAST CONUS THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED PACKAGE. CURRENT FCST GOOD...SOME SNOW SHOWERS WORKING
IN LATER ACROSS THE NORTH...SOME SUN EARLY THIS MORNING.
EARLIER DISCUSSION BELOW.
DRIER WESTERLY FLOW WORKING INTO CENTRAL PA EARLY THIS AM BEHIND
OCCLUDED FRONT. HOWEVER...ABUNDANT LOW LVL MOISTURE AND A CALM
WIND AHEAD OF THIS BOUNDARY CONTINUES TO RESULT IN AREAS OF FOG
ACROSS THE SUSQ VALLEY AT 11Z. LATEST 3KM HRRR SUGGESTS FOG WILL
LIFT ACROSS THE EASTERN ZONES BY ARND 13Z...AS DRIER AIR ARRIVES.
FOCUS THEN SHIFTS TOWARD UPPER LOW SLIDING EAST FROM THE GRT LKS.
LG SCALE FORCING AHEAD OF THIS FEATURE SHOULD SUPPORT SCT -SHSN
ACROSS THE W MTNS LATER TODAY...WHICH WILL LIKELY DUST THE GROUND
OVER THE HIGHER TERRAIN.
CAA AND PLENTY OF STRATO-CU SHOULD KEEP TEMPS FROM RISING MUCH
TODAY...THE EXCEPTION BEING THE LOWER SUSQ VALLEY...WHERE
DRYING/DOWNSLOPING FLOW SHOULD YIELD PTSUNNY SKIES AND TEMPS
REACHING THE M40S. A TIGHTENING PRES GRADIENT BTWN HIGH PRES OVR
THE MIDWEST AND INTENSIFYING LOW SOUTH OF NEW ENG WILL RESULT IN
AN INCREASINGLY GUSTY WNW WIND ACROSS CENTRAL PA TODAY. BUFKIT MDL
SOUNDINGS INDICATE THERE WILL BE GUSTS ARND 25KTS BY MID AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
SCT SNOW SHOWERS ACROSS THE NW MTNS SHOULD TAPER OFF THIS
EVENING...AS UPPER LOW LIFTS OUT AND INVERSION HGTS FALL. EXPECT A
GENERAL CLEARING TREND TONIGHT...AS SFC HIGH BUILDS TOWARD PA FROM
THE MIDWEST. HOWEVER...MDL SOUNDINGS INDICATE LOW LVL MOISTURE
TRAPPED BENEATH INVERSION WILL REMAIN BANKED AGAINST THE NW MTNS
THRU MUCH OF THE NIGHT.
HIGH PRES SHOULD PROVIDE MOST OF THE REGION WITH SUNNY SKIES AND
LGT WINDS MONDAY WITH TEMPS NEAR SEASONAL LEVELS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ALL MED RANGE GUIDANCE INDICATING UPPER LOW OVR THE MISS VALLEY
WILL LIFT NE TOWARD PA ON TUESDAY...PROVIDING INCREASING
CONFIDENCE IN A FAIRLY SIGNIFICANT PRECIP EVENT FOR PA WITH GEFS
MEAN QPF BTWN 0.5 AND 1 INCH. BOTH ECMWF ENSEMBLE MEAN AND GEFS MEAN
SOLUTIONS TRACK A PRIMARY SFC LOW TO OUR WEST WITH A SECONDARY
LIFTING THRU EASTERN PA. THIS SCENARIO WOULD LIKELY RESULT IN SOME
WARMER AIR WORKING IN ALOFT...RESULTING IN MIXED PRECIP TYPES.
ECMWF ENS MEAN 850 TEMPS SUPPORT THE BEST CHC OF WINTRY PRECIP OVR
THE N MTNS WITH RAIN MOST LIKELY IN THE SE.
THE BULK OF THE PRECIP SHOULD BE OVER BY WED...AS SERLY LL JET AND
PLUME OF ANOMALOUS PWATS LIFTS NORTH OF PA. HOWEVER...UNSETTLED/COOL
WX SEEMS LIKELY THRU THE END OF NEXT WEEK WITH MED RANGE MDL DATA
ALL KEEPING UPPER LOW IN THE VICINITY OF PA. ALTHOUGH AIR MASS
DOESN/T LOOK INITIALLY COLD ENOUGH FOR LAKE EFFECT...A
DEEP...MOIST NWRLY FLOW SHOULD YIELD PERSISTENT UPSLOPE SNOW
SHOWERS ACROSS THE W MTNS WED-FRI. LIGHT ACCUMS SEEM PROBABLE ESP
AT NIGHT. DAYTIME TEMPS WED-THU SHOULD GET ABV FREEZING EVERYWHERE
BASED ON ECMWF ENS MEAN 8H TEMPS.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AN UPPER LEVEL LOW OVER THE GREAT LAKES WILL SLIDE EAST ACROSS
UPSTATE NEW YORK TODAY DRAGGING AN OCCLUDED FRONT THROUGH MARKING
THE BEGINNINGS OF DRIER LOW LEVEL AIR...AS WINDS TURN AROUND TO
THE WNW AND BECOME BREEZY. AS THIS HAPPENS THROUGH LATE
MORNING...WIDESPREAD MVFR-IFR CONDITIONS THIS MORNING WILL SWITCH
TO A MORE TYPICAL NW FLOW SCENARIO - WITH MVFR CIGS AND LIGHT SNOW
SHOWERS POSS IN THE WESTERN/NORTHERN HIGHER TERRAIN WHILE CENTRAL
AND SE SECTIONS IMPROVE TO VFR AS DOWNSLOPE FLOW KICKS IN.
ANOTHER SIGNIFICANT WEATHER SYSTEM WILL BRING IMPACTS TO AVIATION
TUE INTO WED.
OUTLOOK...
MON...NO SIG WX EXPECTED.
TUE-THU...STORM SYSTEM BRINGING DETERIORATING CONDITIONS IN
RAIN/SNOW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD/MARTIN
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
747 AM EST SUN FEB 24 2013
.SYNOPSIS...
AN UPPER LEVEL LOW OVER THE GREAT LAKES WILL SLIDE EAST ACROSS
UPSTATE NEW YORK TODAY. A RIDGE OF HIGH PRESSURE WILL BUILD OVER
PENNSYLVANIA ON MONDAY. A STORM SYSTEM OVER THE PLAINS WILL TRACK
NORTHEAST INTO PENNSYLVANIA ON TUESDAY. THE PARENT UPPER LOW WILL
REMAIN OVER THE NORTHEAST CONUS THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DRIER WESTERLY FLOW WORKING INTO CENTRAL PA EARLY THIS AM BEHIND
OCCLUDED FRONT. HOWEVER...ABUNDANT LOW LVL MOISTURE AND A CALM
WIND AHEAD OF THIS BOUNDARY CONTINUES TO RESULT IN AREAS OF FOG
ACROSS THE SUSQ VALLEY AT 11Z. LATEST 3KM HRRR SUGGESTS FOG WILL
LIFT ACROSS THE EASTERN ZONES BY ARND 13Z...AS DRIER AIR ARRIVES.
FOCUS THEN SHIFTS TOWARD UPPER LOW SLIDING EAST FROM THE GRT LKS.
LG SCALE FORCING AHEAD OF THIS FEATURE SHOULD SUPPORT SCT -SHSN
ACROSS THE W MTNS LATER TODAY...WHICH WILL LIKELY DUST THE GROUND
OVER THE HIGHER TERRAIN.
CAA AND PLENTY OF STRATO-CU SHOULD KEEP TEMPS FROM RISING MUCH
TODAY...THE EXCEPTION BEING THE LOWER SUSQ VALLEY...WHERE
DRYING/DOWNSLOPING FLOW SHOULD YIELD PTSUNNY SKIES AND TEMPS
REACHING THE M40S. A TIGHTENING PRES GRADIENT BTWN HIGH PRES OVR
THE MIDWEST AND INTENSIFYING LOW SOUTH OF NEW ENG WILL RESULT IN
AN INCREASINGLY GUSTY WNW WIND ACROSS CENTRAL PA TODAY. BUFKIT MDL
SOUNDINGS INDICATE THERE WILL BE GUSTS ARND 25KTS BY MID AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
SCT SNOW SHOWERS ACROSS THE NW MTNS SHOULD TAPER OFF THIS
EVENING...AS UPPER LOW LIFTS OUT AND INVERSION HGTS FALL. EXPECT A
GENERAL CLEARING TREND TONIGHT...AS SFC HIGH BUILDS TOWARD PA FROM
THE MIDWEST. HOWEVER...MDL SOUNDINGS INDICATE LOW LVL MOISTURE
TRAPPED BENEATH INVERSION WILL REMAIN BANKED AGAINST THE NW MTNS
THRU MUCH OF THE NIGHT.
HIGH PRES SHOULD PROVIDE MOST OF THE REGION WITH SUNNY SKIES AND
LGT WINDS MONDAY WITH TEMPS NEAR SEASONAL LEVELS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ALL MED RANGE GUIDANCE INDICATING UPPER LOW OVR THE MISS VALLEY
WILL LIFT NE TOWARD PA ON TUESDAY...PROVIDING INCREASING
CONFIDENCE IN A FAIRLY SIGNIFICANT PRECIP EVENT FOR PA WITH GEFS
MEAN QPF BTWN 0.5 AND 1 INCH. BOTH ECMWF ENSEMBLE MEAN AND GEFS MEAN
SOLUTIONS TRACK A PRIMARY SFC LOW TO OUR WEST WITH A SECONDARY
LIFTING THRU EASTERN PA. THIS SCENARIO WOULD LIKELY RESULT IN SOME
WARMER AIR WORKING IN ALOFT...RESULTING IN MIXED PRECIP TYPES.
ECMWF ENS MEAN 850 TEMPS SUPPORT THE BEST CHC OF WINTRY PRECIP OVR
THE N MTNS WITH RAIN MOST LIKELY IN THE SE.
THE BULK OF THE PRECIP SHOULD BE OVER BY WED...AS SERLY LL JET AND
PLUME OF ANOMALOUS PWATS LIFTS NORTH OF PA. HOWEVER...UNSETTLED/COOL
WX SEEMS LIKELY THRU THE END OF NEXT WEEK WITH MED RANGE MDL DATA
ALL KEEPING UPPER LOW IN THE VICINITY OF PA. ALTHOUGH AIR MASS
DOESN/T LOOK INITIALLY COLD ENOUGH FOR LAKE EFFECT...A
DEEP...MOIST NWRLY FLOW SHOULD YIELD PERSISTENT UPSLOPE SNOW
SHOWERS ACROSS THE W MTNS WED-FRI. LIGHT ACCUMS SEEM PROBABLE ESP
AT NIGHT. DAYTIME TEMPS WED-THU SHOULD GET ABV FREEZING EVERYWHERE
BASED ON ECMWF ENS MEAN 8H TEMPS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AN UPPER LEVEL LOW OVER THE GREAT LAKES WILL SLIDE EAST ACROSS
UPSTATE NEW YORK TODAY DRAGGING AN OCCLUDED FRONT THROUGH MARKING
THE BEGINNINGS OF DRIER LOW LEVEL AIR...AS WINDS TURN AROUND TO
THE WNW AND BECOME BREEZY. AS THIS HAPPENS THROUGH LATE
MORNING...WIDESPREAD MVFR-IFR CONDITIONS THIS MORNING WILL SWITCH
TO A MORE TYPICAL NW FLOW SCENARIO - WITH MVFR CIGS AND LIGHT SNOW
SHOWERS POSS IN THE WESTERN/NORTHERN HIGHER TERRAIN WHILE CENTRAL
AND SE SECTIONS IMPROVE TO VFR AS DOWNSLOPE FLOW KICKS IN.
ANOTHER SIGNIFICANT WEATHER SYSTEM WILL BRING IMPACTS TO AVIATION
TUE INTO WED.
OUTLOOK...
MON...NO SIG WX EXPECTED.
TUE-THU...STORM SYSTEM BRINGING DETERIORATING CONDITIONS IN
RAIN/SNOW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
634 AM EST SUN FEB 24 2013
.SYNOPSIS...
AN UPPER LEVEL LOW OVER THE GREAT LAKES WILL SLIDE EAST ACROSS
UPSTATE NEW YORK TODAY. A RIDGE OF HIGH PRESSURE WILL BUILD OVER
PENNSYLVANIA ON MONDAY. A STORM SYSTEM OVER THE PLAINS WILL TRACK
NORTHEAST INTO PENNSYLVANIA ON TUESDAY. THE PARENT UPPER LOW WILL
REMAIN OVER THE NORTHEAST CONUS THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DRIER WESTERLY FLOW WORKING INTO CENTRAL PA EARLY THIS AM BEHIND OCCLUDED
FRONT. HOWEVER...ABUNDANT LOW LVL MOISTURE AND A CALM WIND AHEAD
OF THIS BOUNDARY CONTINUES TO RESULT IN AREAS OF FOG ACROSS THE
SUSQ VALLEY AT 11Z. LATEST 3KM HRRR SUGGESTS FOG WILL LIFT ACROSS
THE EASTERN ZONES BY ARND 13Z...AS DRIER AIR ARRIVES. FOCUS THEN
SHIFTS TOWARD UPPER LOW SLIDING EAST FROM THE GRT LKS. LG SCALE
FORCING AHEAD OF THIS FEATURE SHOULD SUPPORT SCT -SHSN ACROSS THE
W MTNS LATER TODAY...WHICH WILL LIKELY DUST THE GROUND OVER THE
HIGHER TERRAIN.
CAA AND PLENTY OF STRATO-CU SHOULD KEEP TEMPS FROM RISING MUCH
TODAY...THE EXCEPTION BEING THE LOWER SUSQ VALLEY...WHERE
DRYING/DOWNSLOPING FLOW SHOULD YIELD PTSUNNY SKIES AND TEMPS
REACHING THE M40S. A TIGHTENING PRES GRADIENT BTWN HIGH PRES OVR
THE MIDWEST AND INTENSIFYING LOW SOUTH OF NEW ENG WILL RESULT IN
AN INCREASINGLY GUSTY WNW WIND ACROSS CENTRAL PA TODAY. BUFKIT MDL
SOUNDINGS INDICATE THERE WILL BE GUSTS ARND 25KTS BY MID AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
SCT SNOW SHOWERS ACROSS THE NW MTNS SHOULD TAPER OFF THIS
EVENING...AS UPPER LOW LIFTS OUT AND INVERSION HGTS FALL. EXPECT A
GENERAL CLEARING TREND TONIGHT...AS SFC HIGH BUILDS TOWARD PA FROM
THE MIDWEST. HOWEVER...MDL SOUNDINGS INDICATE LOW LVL MOISTURE
TRAPPED BENEATH INVERSION WILL REMAIN BANKED AGAINST THE NW MTNS
THRU MUCH OF THE NIGHT.
HIGH PRES SHOULD PROVIDE MOST OF THE REGION WITH SUNNY SKIES AND
LGT WINDS MONDAY WITH TEMPS NEAR SEASONAL LEVELS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ALL MED RANGE GUIDANCE INDICATING UPPER LOW OVR THE MISS VALLEY
WILL LIFT NE TOWARD PA ON TUESDAY...PROVIDING INCREASING
CONFIDENCE IN A FAIRLY SIGNIFICANT PRECIP EVENT FOR PA WITH GEFS
MEAN QPF BTWN 0.5 AND 1 INCH. BOTH ECMWF ENSEMBLE MEAN AND GEFS MEAN
SOLUTIONS TRACK A PRIMARY SFC LOW TO OUR WEST WITH A SECONDARY
LIFTING THRU EASTERN PA. THIS SCENARIO WOULD LIKELY RESULT IN SOME
WARMER AIR WORKING IN ALOFT...RESULTING IN MIXED PRECIP TYPES.
ECMWF ENS MEAN 850 TEMPS SUPPORT THE BEST CHC OF WINTRY PRECIP OVR
THE N MTNS WITH RAIN MOST LIKELY IN THE SE.
THE BULK OF THE PRECIP SHOULD BE OVER BY WED...AS SERLY LL JET AND
PLUME OF ANOMALOUS PWATS LIFTS NORTH OF PA. HOWEVER...UNSETTLED/COOL
WX SEEMS LIKELY THRU THE END OF NEXT WEEK WITH MED RANGE MDL DATA
ALL KEEPING UPPER LOW IN THE VICINITY OF PA. ALTHOUGH AIR MASS
DOESN/T LOOK INITIALLY COLD ENOUGH FOR LAKE EFFECT...A
DEEP...MOIST NWRLY FLOW SHOULD YIELD PERSISTENT UPSLOPE SNOW
SHOWERS ACROSS THE W MTNS WED-FRI. LIGHT ACCUMS SEEM PROBABLE ESP
AT NIGHT. DAYTIME TEMPS WED-THU SHOULD GET ABV FREEZING EVERYWHERE
BASED ON ECMWF ENS MEAN 8H TEMPS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
LIGHT WIND AND NARROW T/TD SPREAD OF JUST A FEW DEG F COMBINED
WITH THE TEMPORARY CLEARING EARLIER THIS EVENING BRINGING SEVERAL
DEG F OF RADIATIONAL COOLING QUICKLY REDEVELOPED THE LOW
STRATUS/STRATOCU DECK ACROSS THE WRN MTNS.
THE CIGS FOR THE REST OF THE OVERNIGHT HOURS /RANGING FROM
GENERALLY MVFR ACROSS THE WEST...TO IFR AND LIFR IN THE EAST WILL
HOLD...OR DROP BY UP TO SEVERAL HUNDRED FEET AS THERE IS LITTLE
DRY/COLD ADVECTION TO SPEAK OF.
VSBYS WILL LIKELY STAY WITHIN THE MVFR RANGE WEST...AND VARY
BETWEEN VLIFR AND IFR IN FOG ACROSS THE SUSQ VALLEY AND PORTIONS
OF CENTRAL MTNS. THE LOWEST CIGS WILL PERSIST ACROSS THE SUSQ VALLEY
/TAF SITES KIPT...KMDT AND KLNS/ UNTIL 10-12Z SUNDAY...BEFORE
GRADUALLY IMPROVING TO MVFR AND BORDERLINE VFR FOR THE LATE
MORNING AND AFTERNOON HOURS SUNDAY.
SOME SNOW SHOWERS AND CONTINUED MVFR FLYING CONDITIONS WILL BE
POSSIBLE AT BFD...AND PERHAPS JST...AS THE UPPER LVL LOW AND COLD
AIR ALOFT WILL BE SLOW TO MOVE OUT.
ANOTHER SIGNIFICANT WEATHER SYSTEM EXPECTED ON TUE.
OUTLOOK...
MON...NO SIG WX EXPECTED.
TUE-THU...STORM SYSTEM BRINGING DETERIORATING CONDITIONS IN
RAIN/SNOW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...LAMBERT/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
550 AM EST SUN FEB 24 2013
.SYNOPSIS...
AN UPPER LEVEL LOW OVER THE GREAT LAKES WILL SLIDE EAST ACROSS
UPSTATE NEW YORK TODAY. A RIDGE OF HIGH PRESSURE WILL BUILD OVER
PENNSYLVANIA ON MONDAY. A STORM SYSTEM OVER THE PLAINS WILL TRACK
NORTHEAST INTO PENNSYLVANIA ON TUESDAY. THE PARENT UPPER LOW WILL
REMAIN OVER THE NORTHEAST CONUS THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DRIER WESTERLY FLOW WORKING INTO CENTRAL PA EARLY THIS AM BEHIND OCCLUDED
FRONT. HOWEVER...ABUNDANT LOW LVL MOISTURE AND A CALM WIND AHEAD
OF THIS BOUNDARY CONTINUES TO RESULT IN AREAS OF FOG ACROSS THE
SUSQ VALLEY AT 10Z. LATEST 3KM HRRR SUGGESTS FOG WILL LIFT ACROSS
THE EASTERN ZONES BY ARND 13Z...AS DRIER AIR ARRIVES. FOCUS THEN
SHIFTS TOWARD UPPER LOW SLIDING EAST FROM THE GRT LKS. LG SCALE
FORCING AHEAD OF THIS FEATURE SHOULD SUPPORT SCT -SHSN ACROSS THE
W MTNS LATER TODAY...WHICH WILL LIKELY DUST THE GROUND OVER THE
HIGHER TERRAIN.
CAA AND PLENTY OF STRATO-CU SHOULD KEEP TEMPS FROM RISING MUCH
TODAY...THE EXCEPTION BEING THE LOWER SUSQ VALLEY...WHERE
DRYING/DOWNSLOPING FLOW SHOULD YIELD PTSUNNY SKIES AND TEMPS
REACHING THE M40S. A TIGHTENING PRES GRADIENT BTWN HIGH PRES OVR
THE MIDWEST AND INTENSIFYING LOW SOUTH OF NEW ENG WILL RESULT IN
AN INCREASINGLY GUSTY WNW WIND ACROSS CENTRAL PA TODAY. BUFKIT MDL
SOUNDINGS INDICATE THERE WILL BE GUSTS ARND 25KTS BY MID AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
SCT SNOW SHOWERS ACROSS THE NW MTNS SHOULD TAPER OFF THIS
EVENING...AS UPPER LOW LIFTS OUT AND INVERSION HGTS FALL. EXPECT A
GENERAL CLEARING TREND TONIGHT...AS SFC HIGH BUILDS TOWARD PA FROM
THE MIDWEST. HOWEVER...MDL SOUNDINGS INDICATE LOW LVL MOISTURE
TRAPPED BENEATH INVERSION WILL REMAIN BANKED AGAINST THE NW MTNS
THRU MUCH OF THE NIGHT.
HIGH PRES SHOULD PROVIDE MOST OF THE REGION WITH SUNNY SKIES AND
LGT WINDS MONDAY WITH TEMPS NEAR SEASONAL LEVELS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ALL MED RANGE GUIDANCE INDICATING UPPER LOW OVR THE MISS VALLEY
WILL LIFT NE TOWARD PA ON TUESDAY...PROVIDING INCREASING
CONFIDENCE IN A FAIRLY SIGNIFICANT PRECIP EVENT FOR PA WITH GEFS
MEAN QPF BTWN 0.5 AND 1 INCH. BOTH ECMWF ENSEMBLE MEAN AND GEFS MEAN
SOLUTIONS TRACK A PRIMARY SFC LOW TO OUR WEST WITH A SECONDARY
LIFTING THRU EASTERN PA. THIS SCENARIO WOULD LIKELY RESULT IN SOME
WARMER AIR WORKING IN ALOFT...RESULTING IN MIXED PRECIP TYPES.
ECMWF ENS MEAN 850 TEMPS SUPPORT THE BEST CHC OF WINTRY PRECIP OVR
THE N MTNS WITH RAIN MOST LIKELY IN THE SE.
THE BULK OF THE PRECIP SHOULD BE OVER BY WED...AS SERLY LL JET AND
PLUME OF ANOMALOUS PWATS LIFTS NORTH OF PA. HOWEVER...UNSETTLED/COOL
WX SEEMS LIKELY THRU THE END OF NEXT WEEK WITH MED RANGE MDL DATA
ALL KEEPING UPPER LOW IN THE VICINITY OF PA. ALTHOUGH AIR MASS
DOESN/T LOOK INITIALLY COLD ENOUGH FOR LAKE EFFECT...A
DEEP...MOIST NWRLY FLOW SHOULD YIELD PERSISTENT UPSLOPE SNOW
SHOWERS ACROSS THE W MTNS WED-FRI. LIGHT ACCUMS SEEM PROBABLE ESP
AT NIGHT. DAYTIME TEMPS WED-THU SHOULD GET ABV FREEZING EVERYWHERE
BASED ON ECMWF ENS MEAN 8H TEMPS.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
LIGHT WIND AND NARROW T/TD SPREAD OF JUST A FEW DEG F COMBINED
WITH THE TEMPORARY CLEARING EARLIER THIS EVENING BRINGING SEVERAL
DEG F OF RADIATIONAL COOLING QUICKLY REDEVELOPED THE LOW
STRATUS/STRATOCU DECK ACROSS THE WRN MTNS.
THE CIGS FOR THE REST OF THE OVERNIGHT HOURS /RANGING FROM
GENERALLY MVFR ACROSS THE WEST...TO IFR AND LIFR IN THE EAST WILL
HOLD...OR DROP BY UP TO SEVERAL HUNDRED FEET AS THERE IS LITTLE
DRY/COLD ADVECTION TO SPEAK OF.
VSBYS WILL LIKELY STAY WITHIN THE MVFR RANGE WEST...AND VARY
BETWEEN VLIFR AND IFR IN FOG ACROSS THE SUSQ VALLEY AND PORTIONS
OF CENTRAL MTNS. THE LOWEST CIGS WILL PERSIST ACROSS THE SUSQ VALLEY
/TAF SITES KIPT...KMDT AND KLNS/ UNTIL 10-12Z SUNDAY...BEFORE
GRADUALLY IMPROVING TO MVFR AND BORDERLINE VFR FOR THE LATE
MORNING AND AFTERNOON HOURS SUNDAY.
SOME SNOW SHOWERS AND CONTINUED MVFR FLYING CONDITIONS WILL BE
POSSIBLE AT BFD...AND PERHAPS JST...AS THE UPPER LVL LOW AND COLD
AIR ALOFT WILL BE SLOW TO MOVE OUT.
ANOTHER SIGNIFICANT WEATHER SYSTEM EXPECTED ON TUE.
OUTLOOK...
MON...NO SIG WX EXPECTED.
TUE-THU...STORM SYSTEM BRINGING DETERIORATING CONDITIONS IN
RAIN/SNOW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...LAMBERT/RXR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
725 AM CST SUN FEB 24 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
725 AM CST SUN FEB 24 2013
HAVE UPDATED GRIDS/ZONES AND CANCELLED THE REST OF THE FREEZING FOG
ADVISORY. FOG REMAINS VERY PATCHY...EVEN ACROSS THE SOUTHWEST END OF
THE FCST AREA...WITH NO RIMING/HOAR FROST/SLIPPERY ROAD CONDITIONS
REPORTED. THEREFORE LET THE REST OF THE ADVISORY GO. FOG AT KLSE IS
VERY LOCAL AND SHALLOW...CONFINED TO THE AIRPORT ITSELF. OFFICE WEB
CAM AND OTHER LOCAL REPORTS SHOW/INDICATE ONLY MINOR HAZE IN THE
REST OF THE NEARBY MS AND LSE RIVER VALLEYS. WHAT FOG IT AT KLSE
SHOULD BURN OFF RATHER QUICKLY NOW THAT THE SUN IS UP.
REMAINDER OF 318 AM SHORT-TERM DISCUSSION FOLLOWS.
THE MAIN FOCUS THROUGH THE EARLY PART OF NEXT WEEK IS WITH THE
NEXT STORM SYSTEM THAT WILL TRACK INTO THE REGION AND BRING THE
POSSIBILITY OF SOME SNOW ALONG WITH IT.
CURRENTLY...SKIES HAVE CLEARED THROUGH MUCH OF THE REGION WITH THE
MAIN EXCEPTION BEING ACROSS NORTHERN WISCONSIN WHERE AN INVERTED
SURFACE TROUGH LINGERS NEAR THE UPPER GREAT LAKES. A SURFACE RIDGE
AXIS RUNS FROM THE TRIPLE POINT OF NORTH/SOUTH DAKOTA AND
MINNESOTA DOWN INTO CENTRAL ILLINOIS AND IS WHERE TEMPERATURES
HAVE DROPPED ENOUGH TO PRODUCE SOME POCKETS OF SHALLOW GROUND FOG.
A FEW SITES IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA HAVE BRIEFLY
GONE DOWN TO A 1/2SM...BUT HAVE JUST AS QUICKLY IMPROVED DUE TO
THE SHALLOW NATURE OF THIS FOG. WITH THE 24.07Z RAP SHOWING THIS
RIDGE AXIS NOT MAKING IT EAST OF THE RIVER UNTIL MID MORNING...AM
NOT EXPECTING MUCH IN THE WAY OF WIDESPREAD FOG IN THIS REGION.
MAY HAVE TO TRIM BACK SOME OF THE FREEZING FOG ADVISORY OVER THE
NEXT FEW HOURS WITH THE CHOPPING BLOCK LIKELY BEING WITH ANY
COUNTIES ALONG AND EAST OF THE MISSISSIPPI RIVER. EVEN IN THE
AREAS WHERE THE FOG DOES OCCUR...IMPACTS ARE EXPECTED TO BE
MINIMAL WITH THE SHORT DURATION OF IT...IF IT EVEN OCCURS. WITH
THE RIDGE AXIS OVER THE REGION TODAY...EXPECT A DECENT DAY WITH
MAINLY SUNNY SKIES AND HIGHS RIGHT AROUND NORMAL.
THIS RIDGE AXIS WILL LINGER ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY INTO MONDAY BEFORE THE NEXT SYSTEM MOVES IN FROM THE
SOUTHWEST AND ESCORTS IT OFF TO THE NORTH BY TUESDAY. THE TREND
FOR THIS NEXT SYSTEM APPEARS TO STILL BE THE SAME WITH THE MORE
SOUTHERLY TRACK THAT KEEPS MUCH OF THE HEAVIER SNOW TO THE SOUTH
OF THE FORECAST AREA. THE 24.00Z NAM/GFS/ECMWF ARE ALL FAIRLY
CLOSE WITH THE TRACK AND TIMING OF THE LOW RUNNING FROM SOUTH
CENTRAL MISSOURI TUESDAY MORNING ON INTO CENTRAL INDIANA BY
TUESDAY EVENING. THE 24.00Z NAM SEEMS TO BE A LITTLE UNDERDONE ON
ITS QPF AS BUFKIT SOUNDINGS OUT OF DBQ SHOW A FULLY SATURATED
SOUNDING FROM LATE TUESDAY AFTERNOON INTO THE OVERNIGHT HOURS BUT
QPF IS 0.00 THERE. HOWEVER...JUST TO THE NORTHWEST OF THAT AREA AT
ALO AND BLR...THESE SAME SOUNDINGS SHOW A SUBSTANTIAL DRY LAYER
THAT WILL NEED TO BE OVERCOME FROM THE SURFACE ON UP TO 700MB. DUE
TO THIS DRY LAYER...AM CONCERNED THAT THE SNOW FROM THIS SYSTEM
MAY NOT MAKE IT VERY FAR TO THE NORTHWEST OF THE MAIN BAND THAT IS
EXPECTED TO BE IN EASTERN IOWA/NORTHERN ILLINOIS. HAVE KEPT THE
CHANCES FOR SNOW GOING FOR THE TIME BEING...BUT THEY MAY HAVE TO
GET TRIMMED BACK IF THE 24.00Z NAM/ECMWF SOUTHEAST TREND HOLDS
FIRM.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
318 AM CST SUN FEB 24 2013
CONFIDENCE IS SOMEWHAT LOW WITH HOW LONG THE LIGHT SNOW MAY HOLD
ON ACROSS THE REGION AS THE TAIL END OF THE SYSTEM MOVES THROUGH.
THERE ARE DIFFERING OPINIONS ON WHERE THE INVERTED SURFACE TROUGH
SETS UP WITH THE 24.00Z ECMWF KEEPING THE AREA DRY THROUGH THE
REST OF THE WEEK WHILE THE 24.00Z GFS/GEM KEEPS SOME LIGHT SNOW IN
THROUGH THURSDAY. KEPT SOME SMALL CHANCES IN THERE FOR NOW INTO
EARLY THURSDAY MORNING...BUT AS MENTIONED FOR TUESDAY...CONFIDENCE
IN HOW FAR NORTHWEST THE SNOW MAKES IT IS PRETTY LOW AT THIS
POINT. DESPITE NORTHERLY FLOW ALOFT AND AT THE SURFACE...THERE IS
NOT MUCH OF A COLD SOURCE OF AN AIR MASS ACROSS CANADA TO PULL ANY
COLD AIR DOWN FROM...SO TEMPERATURES WILL REMAIN AT OR JUST BELOW
NORMAL THROUGH MUCH OF THE NEXT WEEK.
&&
.AVIATION...TODAY AND TONIGHT
545 AM CST SUN FEB 24 2013
MAIN WEATHER CONCERN AT BOTH TAF SITES THRU TONIGHT IS FZFG THRU
15-16Z THIS MORNING. AFTER THAT...MAINLY MID/HIGH CLOUDS AOA 10K FT
TO STREAM ACROSS THE AREA THRU THIS AFTERNOON/TONIGHT...ALONG WITH
LIGHT/VARIABLE WINDS.
AS FOR THE EARLY MORNING FOG...FZFG AT KLSE APPEARS TO BE VERY LOCAL
AND/OR SHALLOW. OFFICE WEB CAM AND VIEW FROM THE OFFICE OFF THE
BLUFF TOP SHOW NO OTHER FOG IN EITHER THE MS VALLEY OR LSE RIVER
VALLEY. EXPECT VSBYS AT KLSE TO BOUNCE AROUND THRU 15Z AS LIGHT
WINDS PUSH WHATEVER FOG IS ON/NEAR THE AIRFIELD AROUND A BIT. WITH
THE FOG SEEMINGLY SHALLOW...IT SHOULD BURN OFF RATHER QUICKLY THIS
MORNING.
AT KRST...DESPITE THREAT OF FZFG VSBYS AT KRST HAVE REMAIN VFR SINCE
MIDNIGHT. ONLY CARRIED A TEMPO 3SM BR AT KRST THRU 14Z WITH SOME
PATCHY MVFR BR ELSEWHERE ACROSS THE HIGHER TERRAIN OF SOUTHEAST MN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
725 AM CST SUN FEB 24 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH/RRS
LONG TERM....HALBACH
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
545 AM CST SUN FEB 24 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
318 AM CST SUN FEB 24 2013
THE MAIN FOCUS THROUGH THE EARLY PART OF NEXT WEEK IS WITH THE
NEXT STORM SYSTEM THAT WILL TRACK INTO THE REGION AND BRING THE
POSSIBILITY OF SOME SNOW ALONG WITH IT.
CURRENTLY...SKIES HAVE CLEARED THROUGH MUCH OF THE REGION WITH THE
MAIN EXCEPTION BEING ACROSS NORTHERN WISCONSIN WHERE AN INVERTED
SURFACE TROUGH LINGERS NEAR THE UPPER GREAT LAKES. A SURFACE RIDGE
AXIS RUNS FROM THE TRIPLE POINT OF NORTH/SOUTH DAKOTA AND
MINNESOTA DOWN INTO CENTRAL ILLINOIS AND IS WHERE TEMPERATURES
HAVE DROPPED ENOUGH TO PRODUCE SOME POCKETS OF SHALLOW GROUND FOG.
A FEW SITES IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA HAVE BRIEFLY
GONE DOWN TO A 1/2SM...BUT HAVE JUST AS QUICKLY IMPROVED DUE TO
THE SHALLOW NATURE OF THIS FOG. WITH THE 24.07Z RAP SHOWING THIS
RIDGE AXIS NOT MAKING IT EAST OF THE RIVER UNTIL MID MORNING...AM
NOT EXPECTING MUCH IN THE WAY OF WIDESPREAD FOG IN THIS REGION.
MAY HAVE TO TRIM BACK SOME OF THE FREEZING FOG ADVISORY OVER THE
NEXT FEW HOURS WITH THE CHOPPING BLOCK LIKELY BEING WITH ANY
COUNTIES ALONG AND EAST OF THE MISSISSIPPI RIVER. EVEN IN THE
AREAS WHERE THE FOG DOES OCCUR...IMPACTS ARE EXPECTED TO BE
MINIMAL WITH THE SHORT DURATION OF IT...IF IT EVEN OCCURS. WITH
THE RIDGE AXIS OVER THE REGION TODAY...EXPECT A DECENT DAY WITH
MAINLY SUNNY SKIES AND HIGHS RIGHT AROUND NORMAL.
THIS RIDGE AXIS WILL LINGER ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY INTO MONDAY BEFORE THE NEXT SYSTEM MOVES IN FROM THE
SOUTHWEST AND ESCORTS IT OFF TO THE NORTH BY TUESDAY. THE TREND
FOR THIS NEXT SYSTEM APPEARS TO STILL BE THE SAME WITH THE MORE
SOUTHERLY TRACK THAT KEEPS MUCH OF THE HEAVIER SNOW TO THE SOUTH
OF THE FORECAST AREA. THE 24.00Z NAM/GFS/ECMWF ARE ALL FAIRLY
CLOSE WITH THE TRACK AND TIMING OF THE LOW RUNNING FROM SOUTH
CENTRAL MISSOURI TUESDAY MORNING ON INTO CENTRAL INDIANA BY
TUESDAY EVENING. THE 24.00Z NAM SEEMS TO BE A LITTLE UNDERDONE ON
ITS QPF AS BUFKIT SOUNDINGS OUT OF DBQ SHOW A FULLY SATURATED
SOUNDING FROM LATE TUESDAY AFTERNOON INTO THE OVERNIGHT HOURS BUT
QPF IS 0.00 THERE. HOWEVER...JUST TO THE NORTHWEST OF THAT AREA AT
ALO AND BLR...THESE SAME SOUNDINGS SHOW A SUBSTANTIAL DRY LAYER
THAT WILL NEED TO BE OVERCOME FROM THE SURFACE ON UP TO 700MB. DUE
TO THIS DRY LAYER...AM CONCERNED THAT THE SNOW FROM THIS SYSTEM
MAY NOT MAKE IT VERY FAR TO THE NORTHWEST OF THE MAIN BAND THAT IS
EXPECTED TO BE IN EASTERN IOWA/NORTHERN ILLINOIS. HAVE KEPT THE
CHANCES FOR SNOW GOING FOR THE TIME BEING...BUT THEY MAY HAVE TO
GET TRIMMED BACK IF THE 24.00Z NAM/ECMWF SOUTHEAST TREND HOLDS
FIRM.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
318 AM CST SUN FEB 24 2013
CONFIDENCE IS SOMEWHAT LOW WITH HOW LONG THE LIGHT SNOW MAY HOLD
ON ACROSS THE REGION AS THE TAIL END OF THE SYSTEM MOVES THROUGH.
THERE ARE DIFFERING OPINIONS ON WHERE THE INVERTED SURFACE TROUGH
SETS UP WITH THE 24.00Z ECMWF KEEPING THE AREA DRY THROUGH THE
REST OF THE WEEK WHILE THE 24.00Z GFS/GEM KEEPS SOME LIGHT SNOW IN
THROUGH THURSDAY. KEPT SOME SMALL CHANCES IN THERE FOR NOW INTO
EARLY THURSDAY MORNING...BUT AS MENTIONED FOR TUESDAY...CONFIDENCE
IN HOW FAR NORTHWEST THE SNOW MAKES IT IS PRETTY LOW AT THIS
POINT. DESPITE NORTHERLY FLOW ALOFT AND AT THE SURFACE...THERE IS
NOT MUCH OF A COLD SOURCE OF AN AIR MASS ACROSS CANADA TO PULL ANY
COLD AIR DOWN FROM...SO TEMPERATURES WILL REMAIN AT OR JUST BELOW
NORMAL THROUGH MUCH OF THE NEXT WEEK.
&&
.AVIATION...TODAY AND TONIGHT
545 AM CST SUN FEB 24 2013
MAIN WEATHER CONCERN AT BOTH TAF SITES THRU TONIGHT IS FZFG THRU
15-16Z THIS MORNING. AFTER THAT...MAINLY MID/HIGH CLOUDS AOA 10K FT
TO STREAM ACROSS THE AREA THRU THIS AFTERNOON/TONIGHT...ALONG WITH
LIGHT/VARIABLE WINDS.
AS FOR THE EARLY MORNING FOG...FZFG AT KLSE APPEARS TO BE VERY LOCAL
AND/OR SHALLOW. OFFICE WEB CAM AND VIEW FROM THE OFFICE OFF THE
BLUFF TOP SHOW NO OTHER FOG IN EITHER THE MS VALLEY OR LSE RIVER
VALLEY. EXPECT VSBYS AT KLSE TO BOUNCE AROUND THRU 15Z AS LIGHT
WINDS PUSH WHATEVER FOG IS ON/NEAR THE AIRFIELD AROUND A BIT. WITH
THE FOG SEEMINGLY SHALLOW...IT SHOULD BURN OFF RATHER QUICKLY THIS
MORNING.
AT KRST...DESPITE THREAT OF FZFG VSBYS AT KRST HAVE REMAIN VFR SINCE
MIDNIGHT. ONLY CARRIED A TEMPO 3SM BR AT KRST THRU 14Z WITH SOME
PATCHY MVFR BR ELSEWHERE ACROSS THE HIGHER TERRAIN OF SOUTHEAST MN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
545 AM CST SUN FEB 24 2013
WI...NONE.
MN...FREEZING FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ086-
094.
IA...FREEZING FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR IAZ008-
009-018-019.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS TUCSON AZ
915 AM MST SUN FEB 24 2013
.SYNOPSIS...LOW PRESSURE WILL MOVE ACROSS THE FOUR CORNERS TODAY
BRINGING ANOTHER SHOT OF COLD AIR TO SOUTHEAST ARIZONA ABOARD BRISK
NORTHWEST WINDS. SNOW SHOWERS WILL GENERALLY BE CONFINED TO AREAS
NEAR THE EASTERN MOUNTAINS. CLEARING AND COLD MONDAY MORNING. DRY
WITH A WARMING TREND MOST OF THE REST OF THE WEEK.
&&
.DISCUSSION...COLD FRONT CONTINUES TO SAG SOUTH ACROSS THE FORECAST
AREA THIS MORNING. BASED ON SURFACE OBSERVATIONS...THE FRONT
EXTENDED FROM NEAR CLIFTON TO JUST SOUTH OF TUCSON. OBS AND RADAR
INDICATED LIGHT SHOWERS WITH MOUNTAIN CAMERAS FROM CATALINAS TO THE
WHITES SHOWING SNOW SHOWERS. THIS AREA OF SHOWERS...BASED ON HRRR
AND RAP MODELS...SHOULD BE AROUND INTO THE AFTERNOON HOURS...THEN
OUT OF THE AREA BY THIS EVENING. OTHERWISE THE WIND AND MUCH COOLER
TEMPERATURES WILL BE THE MAIN STORY FOR TODAY. THE STRONGEST NW
WINDS WILL BE EAST OF TUCSON...ESPECIALLY IN NW-SE ORIENTED
VALLEY...WHERE GUSTS TO 45 MPH ARE POSSIBLE TODAY. HIGHS TODAY WILL
BE 10-15 DEGREES COLDER THAN SATURDAY WITH MOST LOCALS WILL
STRUGGLING TO GET OUT OF THE 40S AND LOW 50S. FORECASTS LOOK TO BE
IN GOOD SHAPE...SO NO UPDATED NEEDED AT THIS TIME.
&&
.AVIATION...WINDS ARE THE MAIN AVIATION CONCERN THROUGH THE TAF
PERIOD. GENERALLY LIGHT WINDS TO BEGIN THE DAY...BUT INCREASING
NORTHWESTERLY WINDS TO DEVELOP BY AROUND 18Z. AT KTUS...WIND GUSTS
NEAR 30 KTS POSSIBLE AFTER 20Z. STRONGEST WINDS EXPECTED AT KDUG
WITH GUSTS APPROACHING 40 KTS BY 21Z. KOLS WILL EXPERIENCE SIMILAR
WINDS AS KTUS. WINDS SHOULD DECREASE NEAR 02Z. MID CLOUD COVER ALSO
EXPECTED TODAY BUT SHOULD REMAIN IN THE VFR RANGE.
&&
.FIRE WEATHER...A COLD LOW PRESSURE SYSTEM DROPPING INTO NORTHERN
ARIZONA AND NEW MEXICO WILL CAUSE NORTHWEST WINDS THIS AFTERNOON
WITH SPEEDS EXCEEDING 30 MPH IN PORTIONS OF COCHISE AND GRAHAM
COUNTIES. MINIMUM HUMIDITY THRESHOLDS OF 15 PERCENT WILL BE
APPROACHED BRIEFLY BUT BE HELD IN CHECK BY THE COLDER TEMPERATURES.
THE FIRE DANGER RATING IS EXPECTED TO REMAIN LOW TO MODERATE AS THIS
SYSTEM PASSES THROUGH. WINDS SUBSIDING LATE TONIGHT WITH A RETURN TO
MORE AVERAGE WIND CONDITIONS ON MONDAY...ALTHOUGH TEMPERATURES WILL
REMAIN COOL.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TO 7 PM MST TODAY FOR AZZ507>509-511>514.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
946 AM MST SUN FEB 24 2013
.UPDATE...WINTER STORM HAS REALLY RAMPED UP THIS MORNING WITH
WIDESPREAD HEAVY SNOW FROM THE FRONT RANGE EASTWARD TO ABOUT
STERLING...AKRON...AND JUST WEST OF LIMON. BASED ON CURRENT
RADAR...SNOWFALL RATES...SPECTACULAR UPPER LEVEL DIVERGENCE NOTED
ON SATELLITE...AND RAP GUIDANCE...HAVE INCREASED SNOWFALL AMOUNTS
ANOTHER 2 INCHES FOR POINTS CLOSER TO THE FRONT RANGE WITH UP TO
4-6 INCHES MORE IN THE SOUTHERN FOOTHILLS. MEANWHILE...SHAVED A
COUPLE INCHES ACCUMULATION OVER THE FAR EASTERN PORTIONS OF THE
FORECAST AREA PER LATEST RADAR TRENDS/MODEL GUIDANCE.
&&
.AVIATION...SIGNIFICANT AVIATION IMPACTS WITH DECREASED ARRIVAL
RATES...VLIFR CONDITIONS...AND HEAVY SNOW/BLOWING SNOW THROUGH AT
LEAST 21Z. SHOULD SEE SLOW BUT GRADUAL IMPROVEMENT AT KDEN
THEREAFTER...BUT KAPA AND KBJC COULD VERY WELL STAY DOWN AT VLIFR
THROUGH 00Z. SNOW WILL THEN DECREASE WITH VISIBILITY GRADUALLY
IMPROVING THROUGH 07Z. TOTAL ACCUMULATIONS LIKELY NEAR 8 INCHES AT
KDEN...AND 10-12 INCHES AT KBJC AND KAPA.
&&
.PREV DISCUSSION... /ISSUED 417 AM MST SUN FEB 24 2013/
SHORT TERM...UPPER LOW OVER SOUTHEAST UTAH CONTINUES TO TRACK
SOUTHEASTWARD TOWARDS THE FOUR CORNERS. LATEST MODEL CONSENSUS
CONTINUES TO TRACK THIS LOW SOUTHEASTWARD DOWN ACROSS CENTRAL NEW
MEXICO BY THIS EVENING AND OUT ACROSS THE TEXAS PANHANDLE BY
MONDAY MORNING. MEANWHILE THE 850-700 MB LOW CONTINUES TO WIND UP
IN SOUTHEAST COLORADO AT THIS HOUR. CIRCULATION AROUND THIS
CYCLONE WILL BE INSTRUMENTAL IN PRODUCING THE IMPRESSIVE SNOW
AMOUNTS OFFERED BY THE VARIOUS MODELS DURING THE NEXT 12-18 HRS.
THERE/S STILL SOME CONCERN THAT THE MORE SOUTHERLY TRACK OF THE
UPPER LOW WILL LIMIT THE LIFT AND THUS THE SNOW AMOUNTS ACROSS
THE FCST AREA. HOWEVER...MODELS...NOTABLY THE LATEST RUC...
CONTINUE TO CRANK OUT RESPECTABLE SNOW AMOUNTS IN AND NEAR THE
FRONT RANGE AND ESPLY OVER THE PALMER DIVIDE BY 00Z/MONDAY...AND
EVEN A BIT MORE ACCUMULATION ALONG THE PALMER DIVIDE THIS EVENING.
IN ADDITION TO THE MODERATE TO HEAVY SNOWFALL ANTICIPATED EAST OF
THE MTNS THIS MORNING THRU EARLY THIS AFTERNOON...MODELS ARE
STILL GENERATING STRONG NORTH-NORTHEAST SFC WINDS ON THE PLAINS
NEXT 12-18 HOURS IN RESPONSE TO THE DEEPENING LOW IN SERN
COLORADO. SPEEDS OF 30-40KTS LOOK BELIEVABLE FOR LATER THIS
MORNING INTO THE AFTERNOON IN THE AREA COVERED BY A BLIZZARD
WARNING. SNOWFALL HAS YET TO DEVELOP IN THIS AREA...BUT STILL
COUNTING ON IT BEGINNING WITHIN THE NEXT HOUR OR TWO. AS FOR THE
HIGH COUNTRY...THIS WAS NEVER MEANT TO BE A BIG SNOW PRODUCER FOR
AREAS WEST OF THE CONTINENTAL DIVIDE. ALTHOUGH SHOULD STILL
RECEIVE ENOUGH SNOW TO WARRANT HANGING ONTO THE WINTER WEATHER
ADVISORY UP THERE. LASTLY...EXTENDED THE WINTER STORM AND
BLIZZARD WARNING ON THE PLAINS TO 06Z TONIGHT...BUT WILL ALLOW
THE WINTER WEATHER ADVY IN THE MTNS AND NORTHEAST PLAINS TO
EXPIRE ON TIME.
LONG TERM...THE UPPER LOW WILL BE OVER THE TEXAS PANHANDLE
MONDAY MORNING BUT THERE IS STILL SOME MOISTURE OVER SOUTH AND
EASTERN PORTIONS OF THE CWA. WILL ADD SOME LOW POPS OVER THE
PALMER DIVIDE REGION DUE TO THE NORTHERLY FLOW EARLY MON AM AND
SLOWER TRACK OF THE STORM.
WEAK RIDGING ALOFT FOR MONDAY EVENING BUT NEXT TROF IS COMING IN
ON ITS HEELS FOR TUESDAY AND TUESDAY NIGHT. THIS NEXT ONE IS
STILL COMING IN AS AN OPEN WAVE SO THE MOUNTAINS LOOK TO BE THE
MAIN BENEFICIARY. HOWEVER THERE IS STILL SOME DECENT UPWARD ASCENT
MOVING OVER CENTRAL COLORADO AND INSTABILITY WITH THIS WAVE.
CHANCES OF PRECIP OVER THE PLAINS WOULD FAVOR THE PALMER DIVIDE
REGION WITH THE MODEST NORTHERLY FLOW. WILL MAINTAIN 20-30 POPS
OVER THE PLAINS THROUGH TUESDAY AFTERNOON AND NIGHT OVER THE
PLAINS. ANOTHER WEAK SYSTEM ON THURSDAY WHICH WILL AGAIN FAVOR THE
MOUNTAINS BUT NOT MUCH MOISTURE TO WORK WITH OVER EASTERN
COLORADO. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THURSDAY
WITH THE UNSETTLED PATTERN. BROAD RIDGING ALOFT BUILDS ACROSS
THE REGION FOR FRIDAY THROUGH SUNDAY WITH A DRYING AND WARMING
TREND.
AVIATION...LIFR AND IFR CONDITIONS IN SNOW AND BLOWING SNOW
THROUGH THE DAY. NORTHERLY WINDS OF 20-30KTS AFTER 16KTS WILL
PRODUCE BLOWING AND DRIFTING SNOW. SNOW AND BLOWING SNOW WILL
POTENTIALLY PRODUCE VISIBILITIES TO NEAR ZERO AT TIMES.
CONDITIONS WILL GRADUALLY IMPROVE THIS EVENING...ADD RETURN TO
MVFR AFTER MIDNIGHT AS THIS LATEST STORM SYSTEM PULLS AWAY FOR
THE FRONT RANGE.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ031-
033-034-038-042-048-050-051.
WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ035-
043-044.
WINTER STORM WARNING UNTIL 8 PM MST THIS EVENING FOR COZ039-040.
WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING FOR COZ036.
BLIZZARD WARNING UNTIL 11 PM MST THIS EVENING FOR COZ041-045>047-
049.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM....ENTREKIN
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
250 PM EST SUN FEB 24 2013
...MODERATE TO LOCALLY HEAVY RAINFALL POSSIBLE LATE TONIGHT INTO
TUESDAY...
...A SLIGHT RISK OF SEVERE THUNDERSTORMS MONDAY THRU TUESDAY...
.CURRENTLY...STATIONARY FRONT NOTED OVER N CENTRAL FL WITH WEAK LLVL
CONVERGENCE NOTED OVER MARION COUNTY. ALOFT...WEAK IMPULSE NOTED
ABOUT 200 MI TO THE WSW OF OCF MOVING ENE WHICH WILL HELP TRIGGER A
FEW SHOWERS AND POSSIBLE STORMS THIS AFTERNOON MAINLY OVER INLAND NE
FL.
.SHORT TERM...
TONIGHT...AS A POTENT CLOSED MID/UPPER LEVEL LOW EJECTS OUT OF THE
SW U.S...THE NEARLY STATIONARY FRONT OVER N CENTRAL FL WILL BEGIN TO
DRIFT BACK NWD AS A WARM FRONT THANKS TO INCREASING SWLY FLOW ALOFT.
A FEW THUNDERSTORMS ARE POSSIBLE OVER THE INLAND NE FL ZONES THIS
EVENING AND MAY CONTINUE TO BE A LOW END CHANCE OVER INLAND ZONES
AFTER MIDNIGHT AS STRONGER FORCING IS REALIZED AS UPPER LEVEL
IMPULSES RIDE ENEWD THROUGH THE CWA. LOWS NEAR 50 N ZONES TO AROUND
60 S ZONES. FOR LATE TONIGHT...HAVE INCLUDED A MENTION OF LOCALLY
HEAVY RAINFALL NEAR THE SUWANNEE VALLEY AREA BASED ON SREF GUIDANCE
AND LATEST RAP FCSTS.
MONDAY...WARM FRONT EXPECTED TO MOVE UP TO NRN FL NEAR I-10 CORRIDOR
AND WILL NOT BUDGE MUCH WITH NMRS TO WIDESPREAD PRECIPITATION...
HEAVY AT TIMES ESPECIALLY OVER SE GA AND HAVE INCLUDED HEAVY
RAINFALL WORDING THERE. RAINFALL AMOUNTS OF 1-2 INCHES POSSIBLE IN
SE GA BUT AT THIS TIME DOES NOT QUITE WARRANT ANY FLOOD WATCHES.
TEMPS WILL BE HELD DOWN BY CLOUDS AND PRECIP WITH 60S N TO UPPER 70S
S ZONES. MONDAY NIGHT...THE BOUNDARY WILL LIFT NWD AS AFOREMENTIONED
MID/UPPER LEVEL LOW MOVES NEWD THROUGH THE MID MS VALLEY...WITH A
TRAILING COLD FRONT MOVING FROM ERN LA AT 00Z TUE TO ABOUT THE
TALLAHASSEE AREA BY 12Z TUE. PRECIP COVERAGE WILL CONTINUE TO BE
HIGH OVER SE GA IN THE EVENING...THEN GRADUAL LESSENING AS THE WARM
FRONT LIFTS NWD AND LIFT WEAKENS SLIGHTLY. THERE WILL BE A POTENTIAL
FOR STRONG/LOCALLY SEVERE TSTMS WITH INCREASING DEEP LAYER SHEAR.
LOWS AROUND 60 TO 65 WILL PREVAIL FOR MONDAY NIGHT.
TUESDAY...THERE CONTS TO BE SOME DISAGREEMENT WITH FRONTAL TIMING
THROUGH OUR CWA WITH THE NAM SLOWER THAN THE GFS AND ECMWF. HAVE
LEANED TOWARD A LITTLE FASTER SOLUTION THAN THE NAM. WE ANTICIPATE
LIKELY SHOWER CHANCES EARLY TUESDAY WITH SCT TSTMS POTENTIAL AS THE
FRONT PRESSES THROUGH THE AREA. THE FRONT IS EXPECTED TO PUSH
OFFSHORE IN THE AFTN WITH RAIN CHANCES DIMINISHED BY MID TO LATE AFTN.
A PREFRONTAL SQUALL LINE IS LIKELY WITH POSSIBLY OF STRONG TO SEVERE
STORMS THOUGH INSTABILITY AS IS TYPICALLY THE CASE IS WEAK BUT
SUFFICIENT FOR SOME STRONG STORMS. THE STORM PREDICTION CENTER HAS
OUR FORECAST AREA IN A SLIGHT RISK FOR SEVERE THUNDERSTORM
DEVELOPMENT. HIGHS WILL CLIMB INTO THE 70S AHEAD OF THE FRONT.
SOUTHWEST SURFACE WINDS MAY APPROACH LAKE WIND ADVISORY CRITERIA
OVER OUR ERN ZONES AFTER SUNRISE ON TUES.
TUESDAY NIGHT THROUGH WED...WEAK HIGH PRES WILL BUILD INTO THE
REGION WITH A MUCH DRIER AIRMASS. NOT VERY COLD BEHIND THE FRONT WITH
LOWS TUE NIGHT IN THE MID 40S TO LOWER 50S AND HIGHS WED NEAR
CLIMATOLOGY AROUND UPPER 60S TO LOWER 70S. PREVAILING LLVL FLOW FROM
THE SW AND W AROUND 10-15 MPH.
.LONG TERM...WED NIGHT-SUN.
GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT AN AMPLIFIED MID/UPPER
PATTERN WILL EXIST DURING THE EXTDD PERIOD WITH A STRONG RIDGE
BUILDING INTO THE ROCKIES AND BROAD TROUGHING LOCATED OVER THE ERN
CONUS. MEAN W TO NW FLOW EXPECTED FOR THE FORECAST AREA WITH A
SERIES OF REINFORCING COLD FRONTS OVER THE SE STATES. A ~995 MB SFC
LOW INITIALLY OVER THE OHIO VALLEY TO PA AREA WILL SHIFT EWD AND
INTO THE WRN ATLC BY THE WEEKEND. THE MODELS SHOW WITH DIFFERING
STRENGTHS AND LOCATION A STRONG SHORTWAVE TROUGH (S) AND SOME
INCREASE IN MOISTURE DROPPING S-SE ON THE WRN SIDE OF THE MEAN LAYER
TROUGH. THIS MAY AFFECT THE SE CONUS LATE FRI THROUGH THE
WEEKEND...WITH A HINT OF POSSIBLE SHOWERS FROM THIS FEATURE IN OUR
CWA BUT CHANCES SEEM BELOW 15% ATTM. CONFIDENCE IN BELOW NORMAL
TEMPS IS HIGH...WITH FREEZES CERTAINLY POSSIBLE FOR INTERIOR
LOCATIONS NEXT WEEKEND DEPENDING ON THE PLACEMENT OF SURFACE RIDGING
OVER THE SOUTHEASTERN STATES. HIGH TEMPERATURES WILL LIKELY REMAIN
IN THE 50S NEXT WEEKEND...WITH PERSISTENT BREEZY NORTHWESTERLY WINDS.
&&
.AVIATION...PREVAILING VFR THIS EVE. WARM FRONT LIFTING INTO THE
AREA BY LATE TONIGHT WILL PRODUCE WIDESPREAD SHOWERS ALONG WITH MVFR
AND POSSIBLY IFR CONDITIONS AT ALL TERMINALS. MVFR CONDITIONS
POSSIBLE IN GNV BY 04Z.
.MARINE...A WARM FRONT WILL LIFT NORTH ACROSS THE WATERS BY LATE
MONDAY. WINDS WILL INCREASE TO SCA OFFSHORE BY MONDAY AFTERNOON
AND THEN CONTINUE AT SCA AND VEER TO THE SOUTH BY TUESDAY WITH THE
APPROACH OF THE COLD FRONT AND THEN SHIFT TO WEST TUESDAY NIGHT
FOLLOWING THE FRONTAL PASSAGE. WIDESPREAD SHOWERS ARE EXPECTED LATE
TONIGHT INTO MONDAY WITH NUMEROUS SHOWERS AND AND SCATTERED STORMS
MONDAY NIGHT AND TUESDAY WITH THE COLD FRONT. WIND AND SEAS MAY BE
HIGHER IN AND NEAR SHOWERS AND STORMS. SCEC TO SCA CONDITIONS WILL
PERSIST FOR THE MUCH OF THE LATTER HALF OF THE WEEK.
RIP CURRENTS: LOW RISK TODAY, MODERATE RISK MONDAY WITH INCREASING
ONSHORE FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 51 61 59 74 / 60 100 90 60
SSI 56 62 60 73 / 60 100 100 60
JAX 56 68 62 78 / 70 90 90 60
SGJ 60 70 66 76 / 60 70 70 60
GNV 58 74 62 76 / 60 70 60 70
OCF 61 78 62 78 / 50 60 60 60
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY FROM NOON MONDAY TO 4 AM EST WEDNESDAY FOR
ALTAMAHA SOUND GA TO FERNANDINA BEACH FL 20 NM TO 60 NM
OFFSHORE-FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM
OFFSHORE-ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM
OFFSHORE.
&&
$$
SHASHY/PETERSON/CHASE
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1240 AM EST SUN FEB 24 2013
...UPDATE...
NO CHANGES WERE MADE TO MORNING FORECAST EXCEPT TO LET DENSE FOG
ADVISORY EXPIRE.
41
.PREV DISCUSSION... /ISSUED 349 AM EST SUN FEB 24 2013/
..DENSE FOG ADVISORY IN EFFECT THIS MORNING...
..FLOOD WATCH IN EFFECT FOR PORTIONS OF NORTH AND ALL OF CENTRAL
GEORGIA MONDAY THROUGH TUESDAY...
SHORT TERM /TODAY THROUGH MONDAY NIGHT/...
LATEST REGIONAL RAP ANALYSIS INDICATES FRONTAL BOUNDARY HAS MADE
ITS WAY THROUGH THE FORECAST AREA WITH NW FLOW AT THE SURFACE.
MOISTURE...ESPECIALLY AT THE EXTREME LOW LEVELS HAS BEEN MUCH
SLOWER TO DEPART RESULTING IN DENSE FOG ACROSS THE REGION. HAVE
BEEN TRACKING TWO SEPARATE AREAS OF DENSE FOG...BOTH OF WHICH ARE
TRANSIENT MAKING THE FORECAST CHALLENGING TO SAY THE LEAST AS FAR
AS VISIBILITY IS CONCERNED THROUGH DAYBREAK. HAVE OPTED TO GO WITH
A DENSE FOG ADVISORY FOR THE ENTIRE AREA AND AS CONDITIONS IMPROVE
THROUGH DAYBREAK...CANCEL COUNTIES OUT AS NECESSARY.
TODAY LOOKS TO BE A TRANSITION DAY ACROSS THE AREA...A MUCH NEEDED
BREAK FROM RECENT RAINFALL ACROSS THE SOUTHERN TIER ALTHOUGH
FLOODING WILL BE ONGOING. SOME 5 INCHES OF RAIN IN AREAS FROM
PREVIOUS SYSTEM AND HAVE AREAL FLOOD WARNING IN EFFECT FOR CRISP
COUNTY. WILL SEE FRONT FRONT SETTLE ACROSS NORTH FLORIDA WITH HIGH
PRESSURE BUILDING IN OVER THE OHIO VALLEY AND RIDGING THROUGH
TENNESSEE AND THE LOCAL FORECAST AREA. FLOW ALOFT LOOKS TO REMAIN
ZONAL TO SLIGHTLY RIDGING AND ONCE LOW CLOUDS CLEAR...WE SHOULD
SEE A STELLAR END TO THE WEEKEND WITH TEMPS IN THE 60S AND EVEN A
FEW LOW 70S TO THE SOUTH.
RESPITE FROM THE RAIN LOOKS QUITE SHORT LIVED AS POTENT SHORTWAVE
DIVES INTO THE SOUTHERN PLAINS CREATING A LARGE SCALE DIFFLUENT
FLOW ALOFT FOR THE SOUTHEAST. ADD TO THIS RIPPLES EMBEDDED IN THE
ZONAL FLOW AND SHOULD SEE AREA OF MODERATE RAIN DEVELOP ACROSS THE
SOUTHERN TIER BY MONDAY MORNING. WITH WEDGE STRENGTHENING OVER THE
CAROLINAS...ADIABATIC OMEGA BECOMES MAXIMIZED DURING THE DAY
MONDAY WITH NEAR CATEGORICAL POPS ANTICIPATED AREA WIDE. WILL
DISCUSS FLOOD IMPLICATIONS FURTHER IN HYDROLOGY SECTION.
BY MONDAY NIGHT...WARM FRONT WILL PUSH INTO THE SOUTHERN MOST
COUNTIES WITH LIMITED SURFACE INSTABILITY BUT INCREASED LOW LEVEL
HELICITY. APPEARS AT THIS POINT THAT SEVERE THREAT WILL BE
ISOLATED AT BEST BUT STILL HAVE A FEW ANALOGS WHICH POINT TO
POTENTIAL ISOLATED TORNADO DEVELOPMENT MONDAY NIGHT INTO TUESDAY
MORNING. SREF ADDS SOME VALIDITY TO THIS WITH PROBABILITY OF 50
PERCENT OF STP OF 1 OR GREATER TUESDAY MORNING.
DEESE
LONG TERM /TUESDAY THROUGH SATURDAY/...
GFS AND ECMWF MODELS SIMILAR THROUGH THE EXTENDED FORECAST PERIOD
CONCERNING THE LARGE SCALE PATTERN. RAIN LIFTING OUT OF THE FORECAST
AREA THROUGH THE DAY TUESDAY AS THE MAIN UPPER LOW AND ASSOCIATED
SURFACE LOW LIFT INTO THE EASTERN OHIO VALLEY. UPPER PATTERN THROUGH
THE MAJORITY OF THE REMAINDER OF THE EXTENDED FORECAST PERIOD
DOMINATED BY MODERATE TO STRONG NORTHWESTERLY FLOW AS BROAD BUT DEEP
UPPER TROUGH LINGERS OVER THE EASTERN U.S. TIGHT SURFACE PRESSURE
GRADIENT PERSISTS AS WELL THROUGH THE PERIOD WITH MODERATE TO STRONG
NORTHWESTERLY FLOW PERSISTING. GFS KEEPS LOW QPF ALONG OUR FAR
NORTHERN COUNTIES WEDNESDAY THROUGH SATURDAY WHILE THE ECMWF KEEPS
THE ENTIRE FORECAST AREA DRY THROUGH ALL BUT THURSDAY. HAVE KEPT THE
PREVIOUS TREND OF SLIGHT CHANCE POPS AND VERY LOW QPF FOR THE FAR
NORTH WEDNESDAY THROUGH SATURDAY. MODEL THICKNESSES AND TEMPERATURES
WOULD INDICATE A CHANCE FOR MIXED PRECIPITATION THROUGH THE
PERIOD...ALTHOUGH WITH THE LOW CHANCES AND LIMITED MOISTURE AVAILABLE
ANY AMOUNTS WOULD LIKELY BE VERY SMALL. THIS TREND WILL NEED TO BE
WATCHED CLOSELY AS WE MOVE INTO THE MIDDLE OF THE WEEK. HOWEVER THIS
PATTERN DOES POINT TO A PERIOD OF BELOW NORMAL TEMPERATURES THROUGH
THE EXTENDED FORECAST PERIOD.
20
HYDROLOGY...QPE FROM PREVIOUS EVENT INDICATES 2 INCHES OF RAIN
FELL FROM ROUGHLY THE ATLANTA METRO TO AS MUCH AS 4 INCHES FOR THE
SOUTHERN TIER. SAME AREA IS TARGETED FOR THIS EVENT WITH AN
ADDITIONAL 2 TO 3 INCHES EXPECTED AND HAVE ISSUED A FLOOD WATCH
THROUGH TUESDAY EVENING.
&&
.AVIATION...
18Z UPDATE...
VFR FORECAST INTO THE OVERNIGHT HOURS WITH NORTHWEST WINDS 5 TO 8KT.
CONDITIONS LOWERING TO MVFR BEYOND SUNRISE MONDAY AS NEXT RAIN
PRODUCING SYSTEM STARTS TO MOVE INTO THE LOWER MISSISSIPPI VALLEY.
WINDS SHOULD SHIFT TO NE 5 TO 10KT LATE TONIGHT AROUND 03Z TO 06Z.
//ATL CONFIDENCE...18Z UPDATE...
HIGH ON ALL ELEMENTS.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 67 38 47 41 / 0 0 90 100
ATLANTA 63 43 47 41 / 0 20 100 100
BLAIRSVILLE 57 35 47 38 / 0 0 70 100
CARTERSVILLE 62 37 48 45 / 0 0 90 100
COLUMBUS 68 50 52 47 / 0 60 100 90
GAINESVILLE 64 38 49 38 / 0 0 90 100
MACON 70 44 51 48 / 0 40 100 80
ROME 62 35 49 47 / 0 0 90 100
PEACHTREE CITY 64 35 48 45 / 0 30 100 100
VIDALIA 72 49 58 55 / 20 40 100 60
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM MONDAY MORNING THROUGH TUESDAY EVENING FOR THE
FOLLOWING ZONES: BALDWIN...BANKS...BARROW...BIBB...BLECKLEY...
BUTTS...CARROLL...CHATTAHOOCHEE...CLARKE...CLAYTON...COBB...
COWETA...CRAWFORD...CRISP...DEKALB...DODGE...DOOLY...DOUGLAS...
EMANUEL...FAYETTE...FORSYTH...GLASCOCK...GREENE...GWINNETT...
HALL...HANCOCK...HARRIS...HEARD...HENRY...HOUSTON...JACKSON...
JASPER...JEFFERSON...JOHNSON...JONES...LAMAR...LAURENS...MACON...
MADISON...MARION...MERIWETHER...MONROE...MONTGOMERY...MORGAN...
MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...PEACH...
PIKE...PULASKI...PUTNAM...ROCKDALE...SCHLEY...SOUTH FULTON...
SPALDING...STEWART...SUMTER...TALBOT...TALIAFERRO...TAYLOR...
TELFAIR...TOOMBS...TREUTLEN...TROUP...TWIGGS...UPSON...WALTON...
WARREN...WASHINGTON...WEBSTER...WHEELER...WILCOX...WILKES...
WILKINSON.
&&
$$
SHORT TERM...DEESE
LONG TERM....20
AVIATION...41
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1159 AM CST SUN FEB 24 2013
...UPDATED FOR AVIATION...
.SYNOPSIS...
ISSUED AT 352 AM CST SUN FEB 24 2013
THE 00Z UPPER AIR ANALYSIS SHOWED A MID/UPPER LEVEL TROUGH OVER THE
GREAT BASIN. THIS TROUGH CONTINUES TO DEEPEN AS IT MOVES SOUTHEAST
AND SHOULD CONTINUE TO DO SO GIVEN A 130 KNOT UPPER LEVEL JET ON THE
BACK SIDE OF THE UPPER TROUGH AND 130 METER HEIGHT FALLS TO ITS
SOUTHEAST. AT THE SURFACE, LOW PRESSURE WAS DEEPENING OVER NORTHEAST
NEW MEXICO. EAST OF THE LOW, UPPER 20S TO LOW 30S DEWPOINTS WERE
SPREADING NORTHWARD TOWARD THE CENTRAL HIGH PLAINS. AREAS OF FOG AND
LOW STRATUS WERE OCCURRING OVER WEST CENTRAL AND NORTHWEST KANSAS
EARLY THIS MORNING WITH SOME INDICATIONS OF DEVELOPMENT INTO
SOUTHWEST KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 352 AM CST SUN FEB 24 2013
VISIBILITIES ACROSS SOUTHWEST KANSAS HAVE BEEN STAYING MOSTLY IN THE
MVFR CATEGORY THROUGH THE EARLY MORNING HOURS WITH THE FAR NORTHERN
LOCATIONS AROUND HAYS SEEING VISIBILITIES OCCASIONALLY DROPPING TO A
QUARTER TO HALF MILE IN FOG. THE RUC13 AND HRRR ARE PICKING UP ON
THE FOG AND ARE SHOWING SOME SIGNIFICANT DEVELOPMENT TO THE SOUTH
ACROSS MUCH OF WEST CENTRAL AND SOUTHWEST KANSAS THROUGH THE NEXT
FEW HOURS THROUGH SUNRISE. THE 11-3.9U FOG CHANNEL HAS BEEN SHOWING
SOME HINTS OF FOG/STRATUS DEVELOPMENT AROUND COLDWATER/MEDICINE
LODGE AND GREENSBURG OVER THE PAST HOUR SO IT APPEARS THAT THERE IS
STILL POTENTIAL FOR THE FOG TO DEVELOP. HAVE LEFT THE DENSE FOG
ADVISORY IN PLACE THROUGH 9AM. IF NOTHING HAPPENS BY SUNRISE THEN
THE ADVISORY MAY BE ADJUSTED OR CANCELLED SOONER.
CONDITIONS ARE CONTINUING TO COME TOGETHER FOR A SIGNIFICANT WINTER
WEATHER EVENT ACROSS PARTS OF THE CENTRAL HIGH PLAINS STARTING THIS
EVENING AND CONTINUING THROUGH MONDAY EVENING. THE 00Z RUNS OF THE
NAM/GFS AND ECMWF ALL SHOW AN UPPER LOW CLOSING OFF OVER NEW MEXICO
BY THIS EVENING AND THEN INTENSIFYING AS IT TRACKS EAST INTO THE RED
RIVER VALLEY ON MONDAY. THE MODELS ARE ALL SHOWING PRECIPITATION
DEVELOPING ACROSS SOUTHWEST KANSAS LATE THIS AFTERNOON AND TONIGHT.
INITIAL PRECIPITATION COULD BE IN THE FORM OF FREEZING DRIZZLE OVER
FAR WESTERN KANSAS BUT THINK THIS WILL BE SHORT LIVED AS THE MID
LEVELS MOISTEN UP AND THE RESULTANT SEEDER/FEEDER MECHANISM CHANGES
PRECIPITATION OVER TO SNOW. FAR SOUTH CENTRAL KANSAS MAY SEE A
RAIN/SNOW MIX FOR A TIME TONIGHT AS TEMPERATURES IN THE LOWER LEVELS
HOVER AT OR SLIGHTLY ABOVE ZERO. AT ANY RATE, SNOW SHOULD BE
DEVELOPING OVER ALL OF SOUTHWEST AND CENTRAL KANSAS AS THE NIGHT
GOES ON AND BECOME HEAVY AT TIMES. SNOWFALL ACCUMULATIONS COULD BE
AS MUCH AS TWO TO FIVE INCHES BY MONDAY MORNING. WITH NORTH WINDS
EXPECTED TO INCREASE TO AROUND 25 TO 35 MPH, THERE WILL BE
CONSIDERABLE BLOWING AND DRIFTING SNOW WITH WIDESPREAD VISIBILITIES
AT A QUARTER MILE OR LESS EXPECTED. WITH THIS IN MIND, HAVE UPGRADED
THE BLIZZARD WATCH TO A BLIZZARD WARNING FOR ALL OF SOUTHWEST INTO
WEST CENTRAL AND SOUTH CENTRAL KANSAS TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 400 AM CST SUN FEB 24 2013
BLIZZARD CONDITIONS WILL CONTINUE MONDAY. VERY DANGEROUS TRAVEL CONDITIONS
ARE EXPECTED ACROSS THE REGION WITH HEAVY MESOSCALE SNOW BANDS DEVELOPING
IN THE 700 HPA DEFORMATION AXIS IN COMBINATION WITH 30 KT SURFACE WINDS.
THE 00Z GUIDANCE STILL SUPPORTS THE ONGOING FORECAST WITH HEAVY SNOW
ACROSS KANSAS. THE NAM SUGGESTS AS HIGH AS 60 KT 850 HPA WINDS, WHICH
WOULD MEAN SUSTAINED WINDS POSSIBLY AS HIGH AS 35-40 KT AT THE SURFACE.
THE ECMWF IS WEAKER WITH THE WIND PROFILE. TRAVEL IS NOT RECOMMENDED
MONDAY...IT WILL BE VERY UNSAFE TRAVEL CONDITIONS WITH WHITEOUT CONDITIONS
AND VERY LARGE SNOWDRIFTS. FOR MORE SPECIFIC INFORMATION REGARDING THE
BLIZZARD, PLEASE SEE THE WARNING TEXT /WSWDDC/. CONDITIONS WILL TAPER
WEST TO EAST THROUGH TUESDAY MORNING AS THE CYCLONE MOVES SOUTHEAST
OF THE REGION.
THE REST OF THE FORECAST WAS LEFT AS IS FROM THE ALLBLEND SOLUTION DUE
TO TIME CONSTRAINTS. HIGHS WILL MODERATE INTO THE 30S AND 40S BY MIDWEEK,
ALTHOUGH THE ALLBLEND NUMBERS COULD BE ON THE HIGH SIDE IF THE HEAVY
SNOWPACK DOES COME INTO FRUITION. LOWS WILL BE IN THE TEENS AND 20S.
AGAIN, THESE VALUES COULD BE ON THE HIGH SIDE IF WE GET SIGNIFICANT
ADDITIONAL SNOWS. THE REST OF THE FORECAST LOOKS DRY AS UPPER LEVEL
RIDGING DEVELOPS OUT WEST AND A DRY NORTHERLY FLOW PATTERN PREVAILS
ACROSS WESTERN KANSAS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1158 AM CST SUN FEB 24 2013
RAPIDLY DETERIORATING CEILINGS AND VISIBILITY WITH TIME IS EXPECTED
DURING THIS TAF PERIOD. AS SURFACE PRESSURE FALLS ACROSS FAR
SOUTHEAST COLORADO CONTINUES, LIFR/VLIFR STRATUS CLOUDS WILL FILL IN
FROM NORTHWEST TO SOUTHEAST ACROSS WESTERN KANSAS TERMINALS SITES.
SNOW WILL DEVELOP OVER THE PANHANDLES AND SPREAD RAPIDLY NORTHWARD
ACROSS THE AREA BETWEEN 00 UTC AND 03 UTC. CONDITIONS WILL
DETERIORATE WITH RESPECT TO BLSN AND M1/4SM VISIBILITIES DURING THE
OVERNIGHT BASED ON EXCELLENT MODEL AGREEMENT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 32 24 32 18 / 40 100 100 60
GCK 32 22 33 13 / 40 90 100 40
EHA 32 18 33 16 / 40 90 100 30
LBL 33 21 33 14 / 30 100 100 40
HYS 30 24 31 21 / 40 100 100 60
P28 34 28 32 25 / 30 100 100 80
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FROM 6 PM CST /5 PM MST/ THIS EVENING TO
MIDNIGHT CST /11 PM MST/ MONDAY NIGHT FOR KSZ030-031-043>046-
061>066-074>081-084>090.
&&
$$
SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...SUGDEN
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1035 AM MST SUN FEB 24 2013
.UPDATE...
ISSUED AT 935 AM MST SUN FEB 24 2013
MADE A QUICK UPDATE TO FORECAST TO CONTINUE DENSE FOG/VERY LIGHT
FREEZING DRIZZLE THROUGH MUCH OF THE DAY AS VISIBILITIES REMAIN LOW
IN FOG ACROSS ALL BUT THE NORTHWEST SECTION OF CWA. ALSO MODIFIED
WX/SNOW GRIDS TO REFLECT CURRENT PRECIPITATION SHIELD WITH SNOW
BEGINNING TO ACCUMULATE AROUND YUMA CO. LATEST RUC HAS A VERY GOOD
HANDLE ON THE PRECIPITATION AND USED IT AS BASELINE FOR FORECAST
OVER NEXT 3-4 HOURS. WHILE THERE DOES APPEAR TO BE A POCKET OF
WEAKER STABILITY IN THE NORTHWEST...DOES NOT APPEAR TO BE
CO LOCATED WITH STRONGER MESOSCALE FORCING AND WILL KEEP AMOUNTS IN
THE 1 TO 3 IN RANGE FOR THE AFTERNOON. STILL ASSESSING NEWEST
GUIDANCE WITH RESPECT TO HOW SYSTEM DEVELOPS TOMORROW.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 416 AM MST SUN FEB 24 2013
MAIN FORECAST CONCERN WILL WINTER STORM THAT WILL AFFECT THE AREA
THROUGH MOST OF THE SHORT TERM. SATELLITE SHOWING A PROGRESSIVE FLOW
OVER THE PACIFIC. THIS TRANSITIONS TO A MORE AMPLIFIED AND SPLIT
FLOW OVER NORTH AMERICA. MAIN FEATURE OF INTEREST IS SYSTEM
DEVELOPING NEAR THE FOUR CORNERS.
AT JET LEVEL...THE ECMWF WAS DOING SLIGHTLY BETTER THAN THE REST OF
THE MODELS. AT MID LEVELS...SATELLITE AND UPPER AIR ANALYSIS WOULD
INDICATE THAT THE UKMET AND GFS HAVE THE BEST HANDLE ON INCOMING
STORM SYSTEM THROUGH. THE HIGH RESOLUTION NAM/RUC FOLLOWED BY THE
ECMWF GO THE SURFACE WIND/PRESSURE FIELD THE BEST. THE GFS AND NAM
WERE DOING SLIGHTLY BETTER ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...DRY MID LEVEL AIR IS BEING DRAWN UP AHEAD OF THE
UPPER SYSTEM. THIS IS ON TOP OF A RATHER MOIST LOW LEVELS PER
CURRENT OBSERVATIONS WITH STRATUS/FOG. MODELS SHOW THAT THE LEFT
FRONT QUADRANT IS AFFECT THE AREA AT 12Z. THIS MOVES SLOWLY SOUTH AND
EAST AND BY LATE AFTERNOON/EARLY EVENING IT IS SOUTH OF THE AREA.
COMPLEX UPPER LOW MOVES INTO THE AREA TODAY AND THEN SPLITS AND/OR
REDEVELOPS FURTHER SOUTH BEGINNING LATER TODAY INTO TONIGHT. MOST
NEW MODEL RUNS ARE FURTHER SOUTH WITH THIS LOW THAN YESTERDAY WITH
THE ENSEMBLES SHOWING THAT SAME TREND AS WELL. IN ADDITION TO BE
FURTHER SOUTH THE MODELS SHOWING THIS REDEVELOPMENT FURTHER WEST AS
WELL. MODELS ARE FURTHER WEST/SLOWER THAN YESTERDAY. ALL THESE TRENDS
MAKES SENSE WITH THE STRONGEST JET WINDS ON THE BACKSIDE OF THE
TROUGH WITH STILL LARGE HEIGHT FALLS AT THE BASE/BEHIND THE TROUGH.
SATELLITE SHOWING/CONFIRMING THIS NICELY.
VERY COMPLEX AND LOW CONFIDENCE FORECAST WITH A NUMBER OF ISSUES TO
ADDRESS. INITIALLY WILL HAVE DENSE FOG COVERING MOST OF THE AREA
THROUGH THE MORNING WITH THE MODELS STILL HAVING A HARD TIME WITH
THIS BUT THE HRRR SEEMS TO HAVE CAUGHT ONTO IT. BECAUSE OF THE
DRIER IN PLACE ABOVE THE SATURATED LOW LAYERS AND THE BETTER LIFT
FURTHER SOUTH AND WEST THAN BEFORE...ALSO NOT ALIGNING WELL WITH
EACH OTHER...AM NOT VERY OPTIMISTIC ABOUT VERY MUCH SNOW OCCURRING.
KEPT THE PATCHY FREEZING DRIZZLE IN THROUGH THE DAY. SNOW SHOULD
DEVELOP IN THE WEST ON THE BACKSIDE OF THE WEAKENING NORTHERN
PORTION OF THIS LOW. BY THE TIME THE SYSTEM GETS ITS ACT TOGETHER
IT IS TOO FAR SOUTH TO GIVE THE AREA A SIGNIFICANT AMOUNT OF SNOW.
SO ENDED UP CUTTING AMOUNTS. NEXT COMES THE WINDS WITH THIS SYSTEM.
BECAUSE OF THE FURTHER SOUTH AND WEST PATH OF THIS SYSTEM...THE
HIGHER WINDS HAVE BEEN PULLED FURTHER SOUTH AND WEST. DO EXPECT
BREEZY CONDITIONS BUT NOTHING STRONG ENOUGH TO WARRANT UPGRADING
THE BLIZZARD WATCH TO A WARNING.
SO BECAUSE OF THE DENSE FOG...JUST ENOUGH SNOW THAT WILL GET BLOWN
BY THE WIND...ADDED YUMA AND KIT CARSON TO THE WINTER WEATHER
ADVISORY AND EXPANDED THE ADVISORY THROUGH THE NIGHT SINCE EXPECT
BLOWING TO CONTINUE EVEN AFTER THE SNOW LETS UP. DUE TO THE MODELS
POOR HANDLING OF HIGH TEMPERATURES WITH THE SNOWFIELD...NOT VERY
CONFIDENT WITH THE MAXES TODAY WHICH ARE EVEN MORE COMPLEX.
MONDAY/MONDAY NIGHT...UPPER LOW KEEPS PULLING AWAY WITH THE OUTER
CONTOURS STILL NEAR THE AREA. GUT FEELING IS THAT DESPITE THE SIZE
OF THE SYSTEM...WITH IT MOVING AWAY AND THE DISTANCE IT IS FROM THE
AREA...FEEL THE QPF IS OVERBLOWN WITH MODELS AND SOME OF MY
NEIGHBORS HOLDING TO THIS TOO LONG. WILL KEEP THE A LOW CHANCE OF
SNOW BUT FEEL IT WILL NOT BE A LOT OF SNOW. WINDS WILL STAY UP AND
DEPENDING ON MUCH SNOW DOES FALL...THERE COULD BE SOME BLOWING SNOW
PROBLEMS. SO KEPT PATCHY BLOWING SNOW IN FOR THE FORECAST. HAVE NO
GOOD FEEL FOR TEMPERATURES.
TUESDAY/TUESDAY NIGHT...MODELS ALL OVER THE PLACE WITH HOW TO HANDLE
THIS TROUGH ONCE IT MOVES AWAY. THERE IS A POSSIBILITY OF SOME
LIGHT SNOW AND FLURRIES CONTINUING THROUGH THIS PERIOD.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY NIGHT)
ISSUED AT 300 AM MST SUN FEB 24 2013
WEDNESDAY-WEDNESDAY NIGHT...RATHER TIGHT PRESSURE GRADIENT ACROSS
THE AREA DURING THE DAY LEADING TO BREEZY/WINDY NORTHWEST WINDS.
CLOUDINESS WILL DECREASE FROM WEST TO EAST LATE IN THE DAY WITH
MOSTLY CLEAR/PARTLY CLOUDY CONDITIONS DURING THE NIGHT AS PRIOR DAYS
STORM SYSTEM CONTINUES TO MOVE AWAY FROM THE AREA.
THURSDAY-THURSDAY NIGHT...UPPER FLOW STARTS TO AMPLIFY OFF THE WEST
COAST WHILE IN OUR AREA IT APPEARS AN UPPER LEVEL DISTURBANCE MOVES
THROUGH FROM THE NORTH/NORTHWEST. SHOULD HAVE SOME INCREASE IN
CLOUDINESS WITH IT. WILL NEED TO WATCH FOR A SMALL THREAT FOR LIGHT
PRECIPITATION LATE THURSDAY AFTERNOON PER 850-500 MOISTURE. JET
POSITION AND 850-500 MOISTURE MAY BE A BIT MORE FAVORABLE ACROSS FAR
EASTERN COLORADO AROUND 12Z FRIDAY.
FRIDAY-FRIDAY NIGHT...AMPLIFIED UPPER RIDGE SLOWLY MOVES ONSHORE AND
ACROSS THE WESTERN 1/4 OF THE COUNTRY. SMALL CHANCE FOR PRECIP
ACROSS FAR EASTERN COLORADO AT 12Z FRIDAY SLIDES SOUTHEAST ACROSS
THE REMAINDER OF THE AREA DURING THE DAY WITH ANOTHER BATCH OF
MOISTURE ALONG/AHEAD OF APPROACHING UPPER JET MOVING IN LATE FRIDAY
NIGHT. WILL KEEP SILENT POPS GOING FOR NOW
SATURDAY-SATURDAY NIGHT...UPPER RIDGE CONTINUES TO MOVE SLOWLY EAST
AND BY THE END OF THE PERIOD SHOULD BE ALONG AND WEST OF THE
CONTINENTAL DIVIDE. SHOULD HAVE SCATTERED CLOUDINESS THROUGH THE
PERIOD WITH DRY CONDITIONS EXPECTED.
TEMPERATURES THROUGH THE PERIOD BELOW NORMAL...NOT ONLY FROM CURRENT
SNOW COVER BUT 850 TEMPERATURES. A SLIGHT WARMUP EXPECTED...MAINLY
ALONG AND WEST OF THE CO/KS BORDER SATURDAY AND SUNDAY UNDER THE
APPROACHING UPPER RIDGE WHERE WARMER 850 TEMPERATURES MOVE INTO THE
AREA.
THANKS TO ALL FOR COLLABORATION THROUGH THE WHOLE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1032 AM MST SUN FEB 24 2013
IFR TO VLIFR CONDITIONS WILL CONTINUE THROUGH MUCH OF THE PERIOD
AS COMBINATION OF FREEZING FOG/DRIZZLE AND LOW STRATUS CONTINUES.
WHILE VISIBILITY HAS BEEN SOMEWHAT VARIABLE...AND WILL LIKELY
BECOME MORE VARIABLE AS WINDS INCREASE...CIGS HAVE REMAINED IN THE
100 TO 400 FT RANGE AND THINK THEY WILL REMAIN SO THROUGH THE
EVENING INTO THE MORNING HOURS. WHILE BOTH TAF SITES WILL BE OUT
OF HEAVIER SNOW ACCUMULATIONS LINGERING FOG/LIGHT SNOW AND
POTENTIALLY BLOWING SNOW WILL KEEP VISIBILITIES UNDER 5 MILES AS
STRONG LOW DEVELOPS ACROSS OKLAHOMA TONIGHT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 5 AM MST /6 AM CST/ MONDAY FOR
KSZ001>004-013>016-027>029-041-042.
CO...WINTER WEATHER ADVISORY UNTIL 5 AM MST MONDAY FOR COZ090>092.
NE...WINTER WEATHER ADVISORY UNTIL 5 AM MST /6 AM CST/ MONDAY FOR
NEZ079>081.
&&
$$
UPDATE...JRM
SHORT TERM...BULLER
LONG TERM...DDT
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
941 AM MST SUN FEB 24 2013
.UPDATE...
ISSUED AT 935 AM MST SUN FEB 24 2013
MADE A QUICK UPDATE TO FORECAST TO CONTINUE DENSE FOG/VERY LIGHT
FREEZING DRIZZLE THROUGH MUCH OF THE DAY AS VISIBILITIES REMAIN LOW
IN FOG ACROSS ALL BUT THE NORTHWEST SECTION OF CWA. ALSO MODIFIED
WX/SNOW GRIDS TO REFLECT CURRENT PRECIPITATION SHIELD WITH SNOW
BEGINNING TO ACCUMULATE AROUND YUMA CO. LATEST RUC HAS A VERY GOOD
HANDLE ON THE PRECIPITATION AND USED IT AS BASELINE FOR FORECAST
OVER NEXT 3-4 HOURS. WHILE THERE DOES APPEAR TO BE A POCKET OF
WEAKER STABILITY IN THE NORTHWEST...DOES NOT APPEAR TO BE
CO LOCATED WITH STRONGER MESOSCALE FORCING AND WILL KEEP AMOUNTS IN
THE 1 TO 3 IN RANGE FOR THE AFTERNOON. STILL ASSESSING NEWEST
GUIDANCE WITH RESPECT TO HOW SYSTEM DEVELOPS TOMORROW.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 416 AM MST SUN FEB 24 2013
MAIN FORECAST CONCERN WILL WINTER STORM THAT WILL AFFECT THE AREA
THROUGH MOST OF THE SHORT TERM. SATELLITE SHOWING A PROGRESSIVE FLOW
OVER THE PACIFIC. THIS TRANSITIONS TO A MORE AMPLIFIED AND SPLIT
FLOW OVER NORTH AMERICA. MAIN FEATURE OF INTEREST IS SYSTEM
DEVELOPING NEAR THE FOUR CORNERS.
AT JET LEVEL...THE ECMWF WAS DOING SLIGHTLY BETTER THAN THE REST OF
THE MODELS. AT MID LEVELS...SATELLITE AND UPPER AIR ANALYSIS WOULD
INDICATE THAT THE UKMET AND GFS HAVE THE BEST HANDLE ON INCOMING
STORM SYSTEM THROUGH. THE HIGH RESOLUTION NAM/RUC FOLLOWED BY THE
ECMWF GO THE SURFACE WIND/PRESSURE FIELD THE BEST. THE GFS AND NAM
WERE DOING SLIGHTLY BETTER ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...DRY MID LEVEL AIR IS BEING DRAWN UP AHEAD OF THE
UPPER SYSTEM. THIS IS ON TOP OF A RATHER MOIST LOW LEVELS PER
CURRENT OBSERVATIONS WITH STRATUS/FOG. MODELS SHOW THAT THE LEFT
FRONT QUADRANT IS AFFECT THE AREA AT 12Z. THIS MOVES SLOWLY SOUTH AND
EAST AND BY LATE AFTERNOON/EARLY EVENING IT IS SOUTH OF THE AREA.
COMPLEX UPPER LOW MOVES INTO THE AREA TODAY AND THEN SPLITS AND/OR
REDEVELOPS FURTHER SOUTH BEGINNING LATER TODAY INTO TONIGHT. MOST
NEW MODEL RUNS ARE FURTHER SOUTH WITH THIS LOW THAN YESTERDAY WITH
THE ENSEMBLES SHOWING THAT SAME TREND AS WELL. IN ADDITION TO BE
FURTHER SOUTH THE MODELS SHOWING THIS REDEVELOPMENT FURTHER WEST AS
WELL. MODELS ARE FURTHER WEST/SLOWER THAN YESTERDAY. ALL THESE TRENDS
MAKES SENSE WITH THE STRONGEST JET WINDS ON THE BACKSIDE OF THE
TROUGH WITH STILL LARGE HEIGHT FALLS AT THE BASE/BEHIND THE TROUGH.
SATELLITE SHOWING/CONFIRMING THIS NICELY.
VERY COMPLEX AND LOW CONFIDENCE FORECAST WITH A NUMBER OF ISSUES TO
ADDRESS. INITIALLY WILL HAVE DENSE FOG COVERING MOST OF THE AREA
THROUGH THE MORNING WITH THE MODELS STILL HAVING A HARD TIME WITH
THIS BUT THE HRRR SEEMS TO HAVE CAUGHT ONTO IT. BECAUSE OF THE
DRIER IN PLACE ABOVE THE SATURATED LOW LAYERS AND THE BETTER LIFT
FURTHER SOUTH AND WEST THAN BEFORE...ALSO NOT ALIGNING WELL WITH
EACH OTHER...AM NOT VERY OPTIMISTIC ABOUT VERY MUCH SNOW OCCURRING.
KEPT THE PATCHY FREEZING DRIZZLE IN THROUGH THE DAY. SNOW SHOULD
DEVELOP IN THE WEST ON THE BACKSIDE OF THE WEAKENING NORTHERN
PORTION OF THIS LOW. BY THE TIME THE SYSTEM GETS ITS ACT TOGETHER
IT IS TOO FAR SOUTH TO GIVE THE AREA A SIGNIFICANT AMOUNT OF SNOW.
SO ENDED UP CUTTING AMOUNTS. NEXT COMES THE WINDS WITH THIS SYSTEM.
BECAUSE OF THE FURTHER SOUTH AND WEST PATH OF THIS SYSTEM...THE
HIGHER WINDS HAVE BEEN PULLED FURTHER SOUTH AND WEST. DO EXPECT
BREEZY CONDITIONS BUT NOTHING STRONG ENOUGH TO WARRANT UPGRADING
THE BLIZZARD WATCH TO A WARNING.
SO BECAUSE OF THE DENSE FOG...JUST ENOUGH SNOW THAT WILL GET BLOWN
BY THE WIND...ADDED YUMA AND KIT CARSON TO THE WINTER WEATHER
ADVISORY AND EXPANDED THE ADVISORY THROUGH THE NIGHT SINCE EXPECT
BLOWING TO CONTINUE EVEN AFTER THE SNOW LETS UP. DUE TO THE MODELS
POOR HANDLING OF HIGH TEMPERATURES WITH THE SNOWFIELD...NOT VERY
CONFIDENT WITH THE MAXES TODAY WHICH ARE EVEN MORE COMPLEX.
MONDAY/MONDAY NIGHT...UPPER LOW KEEPS PULLING AWAY WITH THE OUTER
CONTOURS STILL NEAR THE AREA. GUT FEELING IS THAT DESPITE THE SIZE
OF THE SYSTEM...WITH IT MOVING AWAY AND THE DISTANCE IT IS FROM THE
AREA...FEEL THE QPF IS OVERBLOWN WITH MODELS AND SOME OF MY
NEIGHBORS HOLDING TO THIS TOO LONG. WILL KEEP THE A LOW CHANCE OF
SNOW BUT FEEL IT WILL NOT BE A LOT OF SNOW. WINDS WILL STAY UP AND
DEPENDING ON MUCH SNOW DOES FALL...THERE COULD BE SOME BLOWING SNOW
PROBLEMS. SO KEPT PATCHY BLOWING SNOW IN FOR THE FORECAST. HAVE NO
GOOD FEEL FOR TEMPERATURES.
TUESDAY/TUESDAY NIGHT...MODELS ALL OVER THE PLACE WITH HOW TO HANDLE
THIS TROUGH ONCE IT MOVES AWAY. THERE IS A POSSIBILITY OF SOME
LIGHT SNOW AND FLURRIES CONTINUING THROUGH THIS PERIOD.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY NIGHT)
ISSUED AT 300 AM MST SUN FEB 24 2013
WEDNESDAY-WEDNESDAY NIGHT...RATHER TIGHT PRESSURE GRADIENT ACROSS
THE AREA DURING THE DAY LEADING TO BREEZY/WINDY NORTHWEST WINDS.
CLOUDINESS WILL DECREASE FROM WEST TO EAST LATE IN THE DAY WITH
MOSTLY CLEAR/PARTLY CLOUDY CONDITIONS DURING THE NIGHT AS PRIOR DAYS
STORM SYSTEM CONTINUES TO MOVE AWAY FROM THE AREA.
THURSDAY-THURSDAY NIGHT...UPPER FLOW STARTS TO AMPLIFY OFF THE WEST
COAST WHILE IN OUR AREA IT APPEARS AN UPPER LEVEL DISTURBANCE MOVES
THROUGH FROM THE NORTH/NORTHWEST. SHOULD HAVE SOME INCREASE IN
CLOUDINESS WITH IT. WILL NEED TO WATCH FOR A SMALL THREAT FOR LIGHT
PRECIPITATION LATE THURSDAY AFTERNOON PER 850-500 MOISTURE. JET
POSITION AND 850-500 MOISTURE MAY BE A BIT MORE FAVORABLE ACROSS FAR
EASTERN COLORADO AROUND 12Z FRIDAY.
FRIDAY-FRIDAY NIGHT...AMPLIFIED UPPER RIDGE SLOWLY MOVES ONSHORE AND
ACROSS THE WESTERN 1/4 OF THE COUNTRY. SMALL CHANCE FOR PRECIP
ACROSS FAR EASTERN COLORADO AT 12Z FRIDAY SLIDES SOUTHEAST ACROSS
THE REMAINDER OF THE AREA DURING THE DAY WITH ANOTHER BATCH OF
MOISTURE ALONG/AHEAD OF APPROACHING UPPER JET MOVING IN LATE FRIDAY
NIGHT. WILL KEEP SILENT POPS GOING FOR NOW
SATURDAY-SATURDAY NIGHT...UPPER RIDGE CONTINUES TO MOVE SLOWLY EAST
AND BY THE END OF THE PERIOD SHOULD BE ALONG AND WEST OF THE
CONTINENTAL DIVIDE. SHOULD HAVE SCATTERED CLOUDINESS THROUGH THE
PERIOD WITH DRY CONDITIONS EXPECTED.
TEMPERATURES THROUGH THE PERIOD BELOW NORMAL...NOT ONLY FROM CURRENT
SNOW COVER BUT 850 TEMPERATURES. A SLIGHT WARMUP EXPECTED...MAINLY
ALONG AND WEST OF THE CO/KS BORDER SATURDAY AND SUNDAY UNDER THE
APPROACHING UPPER RIDGE WHERE WARMER 850 TEMPERATURES MOVE INTO THE
AREA.
THANKS TO ALL FOR COLLABORATION THROUGH THE WHOLE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 447 AM MST SUN FEB 24 2013
COMPLICATED TAFS WITH MODEL DATA HELPING MUCH AS THEY ARE HAVING
TROUBLE WITH THE CURRENT CONDITIONS. MODELS UNDERDOING THE EXTENT
OF THE DENSE FOG. THE HRRR AND TO A LESSER DEGREE THE RUC ARE
DOING WELL. VLIFR CONDITIONS ARE EXPECTED UNTIL LATE THIS
AFTERNOON TO EARLY AFTERNOON. IFR/LIFR CEILINGS ARE EXPECTED
THROUGH THE REST OF THE PERIOD. SNOW IS EXPECTED TO DEVELOP BUT
NOT UNTIL LATER THIS AFTERNOON TO EARLY EVENING. MVFR VSIBILITIES
ARE EXPECTED WHEN THE SNOW OCCURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 5 AM MST /6 AM CST/ MONDAY FOR
KSZ001>004-013>016-027>029-041-042.
CO...WINTER WEATHER ADVISORY UNTIL 5 AM MST MONDAY FOR COZ090>092.
NE...WINTER WEATHER ADVISORY UNTIL 5 AM MST /6 AM CST/ MONDAY FOR
NEZ079>081.
&&
$$
UPDATE...JRM
SHORT TERM...BULLER
LONG TERM...DDT
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1213 PM EST SUN FEB 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM EST SUN FEB 24 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED LO THAT HAS
BROUGHT SN/SHSN TO UPR MI THE LAST FEW DAYS MOVING SLOWLY TO THE E
AS UPR RDG AXIS EXTENDING FM HUDSON BAY INTO THE NRN PLAINS DRIFTS
SLOWLY TO THE E. COMBINATION OF LINGERING CYC NLY FLOW AND DEEP MSTR
SHOWN ON THE 00Z APX RAOB HAS ALLOWED SOME SHSN TO PERSIST OVER
MAINLY THE E HALF OF THE CWA UNDER POCKET OF H85/7 TEMPS AS LO AS
-11C/-17C...BUT THE CYC FLOW IS TENDING TO WEAKEN WITH SFC LO
SHIFTING TO THE E. IN FACT...THE WINDS AT STANNARD ROCK HAVE FALLEN
NEAR 5KTS EARLY THIS MRNG. 00Z RAOBS AT INL/YPL TO THE W/NW ALSO
SHOW A PRONOUNCED DRYING TREND ASSOCIATED WITH INCOMING RDG...WHICH
DROPPED THE INVRN BASE AS LO AS H9 AT YPL AT 00Z. 00Z H85 TEMPS
RANGE FM -11C AT GRB TO -6C AT INL AND -5C AT YPL. RECENT RADAR
TRENDS SHOW PERSISTENT HEAVIER SHSN THAT IMPACTED THE MQT AREA ARE
DIMINISHING WITH WEAKENING FLOW/SOME UPR DRYING UNDER DEEP LYR
QVECTOR DVGC/SUBSIDENCE LEFT IN THE WAKE OF SLOWLY DEPARTING CLOSED
LO. BUT SFC OBS/STLT IMAGERY SHOW LO CLDS LINGERING W INTO THE MN
ARROWHEAD. SKIES HAVE CLEARED OVER CNTRL MN UNDER SFC RDG AXIS.
FARTHER TO THE W...THERE IS A SHRTWV MOVING THRU SASKATCHEWAN.
PLENTY OF MID/HI CLDS ARE PRESENT TO THE E OF THIS DISTURBANCE...BUT
PCPN APPEARS LIMITED BY RATHER DRY LLVLS SHOWN ON THE 00Z BISMARCK
RAOB. ANOTHER MORE POTENT SHRTWV IS MOVING THRU THE SCENTRAL
ROCKIES. OTRW...THERE IS A LACK OF TRUE ARCTIC AIR OVER THE NRN
CONUS/SRN CANADA. IN FACT...THE 00Z H85 TEMP OF -11C AT GRB IS THE
LOWEST H85 TEMP IN CANADA S OF THE NW TERRITORIES AND NRN QUEBEC.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON CLD TRENDS/
IMPACT ON TEMPS.
TODAY...AS CLOSED LO SLIDES TO THE E...UPR RDG IS PROGGED TO BLD
OVER THE UPR LKS...RESULTING IN 12HR H5 HGT RISES UP TO 100M UNDER
INFLUENCE OF DEEP LYR QVECTOR DVGC/SUBSIDENCE. WITH SFC HI PRES RDG
AXIS FCST TO SHIFT INTO THE W HALF OF THE CWA BY 00Z MON...EXPECT
ANY LINGERING -SHSN TO END W-E. WITH LLVL NW FLOW PERSISTING THRU
THE DAY OVER THE E AHEAD OF INCOMING RDG AXIS...MIGHT EXPECT AT
LEAST SCT -SHSN TO PERSIST THERE. BUT FCST H85 TEMPS TO -8C TO -9C
IN THAT AREA /COMPARED TO LK WATER TEMPS 1 TO 2C/ BY 00Z AS WELL AS
DIFFLUENT NATURE OF THE INCRSG ACYC FLOW INDICATE THE ACTIVITY WL
END EVEN THERE IN THE AFTN. CLD TRENDS WL BE MORE DIFFICULT TO PIN
DOWN. AS THE SFC RDG AXIS ARRIVES...FCST SDNGS SHOWN INVRN BASE
SINKING TOWARD H9...WHICH MIGHT TRAP LINGERING LLVL MSTR AND RESULT
IN SC OVC. BUT WITH ACYC LLVL FLOW...SUSPECT SOME BREAKS IN THE CLDS
MAY DVLP OVER THE W NEAR THE WI BORDER LATER IN THE DAY...WHICH IS
CONSISTENT WITH THE CLRG OBSVD EARLY THIS MRNG CLOSER TO THE RDG
AXIS IN MN. AREAS OVER THE SCENTRAL FARTHER FM LK SUP INFLUENCE MAY
ALSO SEE SOME CLRG DESPITE RATHER WEAK WINDS/DOWNSLOPE IMPACT.
TNGT...THE SFC RDG AXIS IS PROGGED TO DRIFT SLOWLY TO THE E TNGT.
WITH WSHFT TO THE SW...EXPECT AT LEAST SOME BREAKS IN THE LINGERING
LO CLDS. WITH LGT WINDS...LOCATIONS THAT SEE SOME CLRG MIGHT SEE
TEMPS DROP SHARPLY. SO MAINTAINED FLAVOR OF GOING FCST SHOWING MIN
TEMPS DROPPING TOWARD THE LO END OF GUIDANCE. SOME HI CLDS AHEAD OF
SHRTWV MOVING ACRS SCENTRAL CANADA MAY MOVE INTO THE W LATE. SINCE
FOG HAS DVLPD UPSTREAM WHERE SKIES CLEARED IN MN...ADDED A MENTION
OF PATCHY FOG OVER THE INTERIOR AFTER MIDNGT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 323 AM EST SUN FEB 24 2013
MUCH OF THE WEATHER FOR THE LONG TERM WILL BE DOMINATED BY THE
CURRENT 500MB LOW/TROUGH CENTERED OVER UTAH AND WESTERN COLORADO.
LOOK FOR THE LOW TO DEEPEN AS IT ROUNDS NORTHERN TEXAS ON
MONDAY...WITH A DISTINCT/WRAPPED UP SFC LOW DEVELOPING.
EXPECT A PROLONGED PERIOD OF WINDS FROM THE NORTHEAST QUADRANT
/360-90 DEGREES/ FROM TUESDAY THROUGH AT LEAST SATURDAY. IF
TEMPERATURES WERE COLDER WE WOULD BE LOOKING AT AN EXTENDED PERIOD
OF MODERATE LAKE EFFECT SNOW SHOWERS ACROSS MUCH OF THE AREA...AND
PARTICULAR NORTH CENTRAL UPPER MICHIGAN. HOWEVER...SURFACE TEMPS
NEAR FREEZING AND 850MB TEMPS -3C TO -5C TUESDAY THROUGH WEDNESDAY
WILL ONLY SUPPORT SOME LAKE ENHANCEMENT TO THE SNOW ROTATING AROUND
THE BACK SIDE OF THE SURFACE LOW FROM TUESDAY NIGHT ON.
THE GFS REMAINS STRONGEST WITH THE N/NNE WINDS THROUGH MUCH OF THE
PERIOD...WITH WINDS NEAR OR ABOVE 30KTS FROM WEDNESDAY AFTERNOON
THROUGH FRIDAY ACROSS LAKE SUPERIOR. THE ECMWF RANGES FROM 3-9KTS
LIGHTER WITH THE WINDS...THANKS TO THE OVERALL WEAKER LOW EJECTING
FROM THE SOUTHERN PLAINS AND ACROSS ILLINOIS TUESDAY...AND OVER
LOWER MICHIGAN WEDNESDAY. THIS IS THE MAIN DIFFERENCE...WHETHER THE
LOW ENDS UP BEING 992MB /23/18Z GFS/ OR 1000MB /23/12Z ECMWF/ AS IT
CROSSES INTO SOUTHERN LOWER MI WEDNESDAY MORNING. EVEN THROUGH THE
TRACK OF THE SFC LOW MAY BE A BIT ON THE QUICK SIDE OFF OF THE
ECMWF...THE CONSENSUS IS TO HAVE A WEAKER SYSTEM THAN WHAT IS
INDICATED BY THE GFS. THE 00Z RUN OF THE GFS CAME IN SLIGHTLY WEAKER
AND FARTHER S OF ITS 18Z RUN TRACK /APPROX 250MI SSE OF THE 18Z RUN
LOW AT 12Z THURSDAY/...WHICH ALSO DIMINISHED WIND SPEEDS ON THE
ORDER OF 2-5KTS. THE SLIGHTLY EASTWARD 23/12Z AND 24/00Z ECMWF RUNS
FOR THE LOW TRACK DO NOT LOOK LIKE SUCH AN OUTLIERS ANYMORE.
ANOTHER EXTENDED SFC TROUGH WILL LINGER ACROSS OUR AREA THROUGH
FRIDAY NIGHT...DESPITE STRONG HIGH PRESSURE PUSHING IN FROM THE
WEST. COLD AIR WILL REMAIN TRAPPED OVER NORTHEASTERN CANADA...WITH
-12C 850MB TEMPS OVER ONTARIO...-8 TO -10C ACROSS UPPER MICHIGAN
THURSDAY AFTERNOON THROUGH SATURDAY. WITH DRY HIGH PRESSURE
FILTERING IN AT THE SFC AND ALOFT...EXPECT DIMINISHING LAKE ENHANCED
PRECIPITATION NEAR LAKE SUPERIOR WITH ONLY MINOR ACCUMULATIONS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1212 PM EST SUN FEB 24 2013
VERY TRICKY AVIATION FORECAST FOR THE NEXT 24 HOURS...AS CONDITIONS
LARGELY DEPEND ON THE LOW CLOUDS TRAPPED UNDER THE INCREASING
INVERSION FROM A HIGH PRESSURE RIDGE MOVING ACROSS UPPER MICHIGAN.
EXPECT MVFR CONDITIONS AT ALL THREE SITES INTO THE EARLY
EVENING...ALTHOUGH SOME DRYING OVER WESTERN LAKE SUPERIOR COULD
LEAD TO A FEW BREAKS AT KCMX. THEN AS DIURNAL HEATING IS LOST...A
SLIGHTLY DRIER POCKET OF AIR IN SOUTH CENTRAL UPPER MI...WHERE CU
HAS DEVELOPED THIS AFTERNOON...WILL LIKELY SCATTER OR CLEAR
OUT. WITH WINDS BACKING TO THE SOUTHWEST...THINK THIS WILL
INFLUENCE KSAW AND HAVE CONTINUED MENTION OF SCATTERED CLOUDS. THE
MORE PERSISTENT MOISTURE/CLOUDS IN NORTH CENTRAL WI MAY KEEP
KIWD/KCMX CLOUDY THROUGH THE NIGHT...ALTHOUGH WITH INCREASING
SOUTHWEST FLOW ALOFT OVERNIGHT...COULD SEE KIWD SCATTER OUT LATE
TONIGHT OR MONDAY MORNING.
IF LOCATIONS SCATTER OUT...WOULD EXPECT TEMPERATURES TO QUICKLY
FALL AND FOG TO DEVELOP. HAVE CONTINUED MVFR VISIBILITIES DUE TO
UNCERTAINTY...BUT BASED ON OBS LAST NIGHT IN MINNESOTA...COULD SEE
IFR VISIBILITIES...ESPECIALLY AT KSAW/KIWD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 323 AM EST SUN FEB 24 2013
THE TROUGH OF LOW PRESSURE OVER EASTERN LAKE SUPERIOR WILL SLOWLY
DISSIPATE TODAY AS HIGH PRESSURE BUILDS ACROSS THE UPPER GREAT LAKES
THROUGH MONDAY NIGHT. EXPECT LOW PRESSURE OVER THE SOUTHERN PLAINS
SUNDAY NIGHT TO TRACK NORTHEAST ACROSS THE MID MISSISSIPPI VALLEY ON
TUESDAY...BEFORE MOVING THROUGH THE LOWER GREAT LAKES WEDNESDAY INTO
WEDNESDAY NIGHT...WITH A PROLONGED PERIOD OF N-NE WINDS FROM TUESDAY
THROUGH SATURDAY. THE LOW WILL MOVE EASTWARD THROUGH THURSDAY WHILE
LEAVING YET ANOTHER TROUGH OVER LAKE SUPERIOR AS HIGH PRESSURE MOVES
EAST THROUGH MANITOBA. THE NORTH WINDS ARE EXPECTED TO INCREASE
SLIGHTLY FOR THURSDAY WITH A FEW GALE FORCE GUSTS POSSIBLE.
OTHERWISE...WINDS SHOULD REMAIN BELOW 30KTS THROUGH THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...SRF
MARINE...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1127 AM CST SUN FEB 24 2013
.DISCUSSION...
MORE AND MORE...THE UPCOMING WEEK IS LOOKING DRY...AS MODELS
CONTINUE TO TREND THE BIG MIDWEEK WINTER STORM SOUTH AND EAST OF THE
MPX AREA. OTHERWISE...ONLY CONCERN TONIGHT AND AGAIN MONDAY NIGHT
WILL BE FOR REPEAT PERFORMANCES OF DENSE FOG.
OUT THE GATE THIS MORNING...MOIST BOUNDARY LAYER HAS COMBINED WITH
CLEAR SKIES AND LIGHT WINDS UNDER A SFC RIDGE ACROSS THE WRN HALF OF
MN TO GET SOME FAIRLY WIDESPREAD FOG GOING. PRETTY SOLID AREA OF 1/2
MILE OR LESS VIS FROM WEST CENTRAL UP THROUGH NW MN. FROM THE TWIN
CITIES ON EAST...STUBBORN CLOUD LAYER HAS KEPT FOG FROM FORMING. AS
FOR CURRENT ADVY...WILL TRIM COUNTIES UNDER THE INFLUENCE OF CLOUDS
OUT OF WHILE LEAVING THE REST IN PLACE...THOUGH MAY EXPAND IT ACROSS
THE REST OF SOUTH CENTRAL MN GIVEN DENSE FOG OBS AT FAIRMONT AND ST.
JAMES. BASED ON VIS FORECASTS FROM HRRR AND HOPWRF ENSEMBLE...NOT
EXPECTING ANY SIGNIFICANT IMPROVEMENTS UNTIL AFTER 15Z. IN
FACT...WHERE FOG IS MOST DENSE AROUND THE AXN AREA...MAY NOT BE
UNTIL CLOSER TO 18Z BEFORE SIGNIFICANT IMPROVEMENTS ARE MADE. THE
SLOW VIS RECOVERY IS SUPPORTED PHYSICALLY BY THE FACT THAT WE STILL
HAVE A SOMEWHAT SHALLOW LATE FEBRUARY SOLAR ANGLE AND VIRTUALLY NO
WIND IS EXPECTED WITHIN THE LOWEST 7K FT OF THE ATMO TODAY TO HELP
MIX THINGS OUT.
AS FOR FOG POTENTIAL AFTER TONIGHT...THE MPX AREA WILL REMAIN UNDER
A COL IN THE PRESSURE FIELD THROUGH MONDAY NIGHT...RESULTING IN WEAK
WINDS AND THEREFORE WEAK MECHANICAL MIXING. THE BIG QUESTION MARK
THE NEXT TWO NIGHTS WILL BE MID/UPPER LEVEL CLOUDS. TONIGHT LOOKS TO
OFFER A DECENT AMOUNT OF UPPER CLOUDS AS COMPLEX UPPER TROUGH
CURRENTLY OVER THE HIGH PLAINS MOVES OVERHEAD. SATELLITE IMAGERY
SHOWS PLENTY OF CLOUD COVER ASSOCIATED WITH THIS TROUGH AND AS THIS
PUSHES EAST DURING THE DAY...THIS SHOULD RESULT IN PLENTY OF
MID/UPPER CLOUDS TONIGHT. MONDAY NIGHT MAY FEATURE LESS CLOUD COVER
AS THE NRN STREAM WAVE SHEARS OUT. FORECAST SOUNDINGS BOTH NIGHTS
SHOW PLENTY OF LOW LEVEL MOISTURE BEING IN PLACE UNDER THE SFC RIDGE
TO SUPPORT FOG FORMATION...SO LONG AS THERE IS MINIMAL CLOUD COVER.
WITH UNCERTAINTIES IN CLOUD COVER BOTH NIGHTS...DID NOT MENTION ANY
FOG IN THE FORECAST...BUT THIS IS SOMETHING THAT WILL NEED TO BE
WATCHED CLOSELY.
WHEN IT COMES TO PRECIPITATION...NOW DOWN TO BASICALLY ONE
MODEL...THE GEM...THAT IS STILL BRINGING PRECIP TO THE AREA MID WEEK
IN ASSOCIATION WITH THE DEEP TROUGH NOW OVER THE 4-CORNERS. MODELS
ALL PRETTY SIMILAR WITH TAKING THIS UPPER LOW FROM NEW MEXICO TODAY
OVER TO THE LAKE ERIE REGION BY WEDNESDAY. THIS WILL BE QUITE THE
IMPRESSIVE SYSTEM...WITH H5 HEIGHT FALLS ON THE ORDER OF 200M AND A
WELL DEFINED H7 LOW. HEAVY SNOW SWATH STILL LOOKS LIKE A GOOD BET
FROM THE NE TX PANHANDLE UP INTO THE CHICAGO METRO AREA AND MID
MICHIGAN. FOR THE MPX AREA...WE WILL BE BATTLING RATHER STRONG DRY
AIR ADVECTION AND SUBSIDENCE ON THE NORTH SIDE OF THE SYSTEM. ONLY
REAL HOPE FOR PRECIP IN THE MPX AREA LOOKS TO COME TUESDAY NIGHT
INTO WEDNESDAY AS SFC LOW IS TRACKING FROM SRN IL TOWARD NRN OH. THE
QUESTION HERE IS HOW FAR NW DOES EXPANSIVE WRAP-AROUND PRECIP SHIELD
MAKE IT. AT THIS POINT...ONLY THE WRN OUTLIER GEM IS SHOWING PRECIP
ACROSS THE MPX CWA...WITH EVEN THE 24.03 SREF TRENDING SE WITH
PRECIP...KEEPING EVEN ERN AREAS WEST OF THE PRECIP. IF THIS TREND
CONTINUES...FUTURE SHIFTS COULD PROBABLY START PULLING OUT PRECIP
MENTION COMPLETELY. AS FOR WIND AND BLOWING SNOW POTENTIAL MID
WEEK...STILL EXPECT SPEEDS TO PICK UP TUESDAY THROUGH THURSDAY...BUT
WITH THE MAIN SFC LOW GOING AS FAR SOUTH AS IT IS...NOT EXPECTING
WINDS STRONG ENOUGH TO LEAD TO SIGNIFICANT ISSUES. LIKE TO SEE GUST
POTENTIAL OVER 30 MPH TO START SEEING SIGNIFICANT BLOWING SNOW
ISSUES...AND FORECAST SOUNDINGS FROM THE GFS KEEP EVERYTHING IN THE
20S.
FINALLY...WITH TEMPERATURES...NOT EXPECTING MUCH VARIATION OVER THE
NEXT WEEK AS 925-850 TEMPS LOOK TO STAY MORE OR LESS UNCHANGED. THIS
MEANS WE SHOULD CONTINUE TO SEE LOWER ALBEDO AREAS ACROSS CENTRAL
AND EAST CENTRAL MN INTO WRN WI WITH HIGHS MAINLY IN THE 30S...WHILE
HIGHER ALBEDO AREAS FROM WEST CENTRAL INTO SOUTH CENTRAL MN SEE HIGH
MAINLY SEE IN THE 20S. FOR LOWS...FOR THE NEXT COUPLE OF NIGHTS WITH
THE COL IN THE PRESSURE FIELD REMAINING OVERHEAD...THIS WILL LEAD TO
THE POTENTIAL FOR LOWS AROUND ZERO WHERE EVER A FEW HOURS OF
CLEARING CAN BE SEEN. OTHERWISE...LOWS WILL REMAIN ON THE MILD END
UNDER THE INFLUENCE OF CLOUDS...REMAINING UP IN THE TEENS AND 20S.
&&
.AVIATION.../18Z TAF ISSUANCE/
VERY SIMILAR CONCERNS WITH THIS TAF PERIOD AS LOW LEVEL WINDS AND
MIXING REMAINS NEARLY NON-EXISTENT UNTIL AFT 00Z/26...OR UNTIL THE
MAIN STORM SYSTEM THAT IS EXPECTED TO DEVELOP ACROSS THE
PLAINS...BEGINS TO INTERACT WITH THE SFC RIDGE OVER OUR REGION.
THIS WOULD LEAD TO A MORE MORE PREVAILING E/NE WIND FLOW MONDAY
NIGHT/TUE. IN THE SHORT TERM...AND MAINLY THE AFFECTS OF CLOUD
COVER AND LITTLE MIXING...CONFIDENCE REMAINS LOW ON THE
REDEVELOPMENT OF FG/BR OVERNIGHT. WILL CONTINUE THE SAME
PERSISTENT TREND WITH LOW CLDS AND VERY LOW VSBYS DEVELOPING
OVERNIGHT. BUT WITH THE AMT OF CLOUD COVER SPREADING E/NE ACROSS
THE UPPER MIDWEST...THIS WILL PLAY HAVOC ON ANY RADIATIONAL FG/BR
AFFECTS AND MORE MVFR/IFR VSBYS AND LITTLE IN THE WAY OF LOW CIGS.
THIS WAS THE CASE IN WC WI OVERNIGHT WHERE THE CLDS KEPT THE
AFFECTS OF RADIATIONAL COOLING AT A MINIMAL.
KMSP...
BEST SCENARIO FOR THIS TAF PERIOD IS PERSISTENCE AS MORE CLOUDS
SPREADING NE ACROSS IA...WILL BEGIN TO AFFECT SC/SE/EC MN BY THE
LATE AFTN/EARLY EVENING TIME PERIOD. THESE CLOUDS ARE WELL DEFINED
IN THE LATEST 3.9U SATELLITE IMAGERY ACROSS NW IA...WITH A BLEND
OF HIGHER CLDS/BR ACROSS THE REST OF THE FA. BEST TIME FRAME FOR
THE MVFR CIGS TO SPREAD INTO EC MN WILL BEGIN AFT 22-23Z THIS
AFTN. THIS WILL LIKELY HINDER THE AFFECTS OF RADIATIONAL COOLING
AND THE FORMATION OF BR/FG OVERNIGHT. HOWEVER...THIS CLOUDS ARE
EXPECTED TO DISSIPATE BY 6Z...WHICH WILL LEAD TO LESS CLOUD COVER
AND MORE IN THE WAY OF FG/BR FORMATION. THE WORSE CONDS WILL
LIKELY BE THE TYPICAL 09-15Z TIME FRAME WITH THE POSSIBILITY OF
LIFR CIGS/VSBYS. A GENERAL TREND OF CIGS SLOWLY RISING TO MVFR BY
18Z...AND POSSIBLY ABV 1.7K BY THE EARLY AFTN. WINDS WILL BE
NEARLY CALM...WITH A SLIGHT TREND OF A SE COMPONENT THIS
AFTN...AND MORE OF A SW COMPONENT MONDAY.
/OUTLOOK FOR KMSP/
TUE...MVFR WITH IFR AND -SN POSSIBLE. WINDS N 10G15KTS.
WED...MVFR POSSIBLE IN THE MORNING...OTHERWISE VFR. WINDS NNE 10KTS.
THU...MVFR/VFR CIGS WITH -SN POSSIBLE. NW WIND 10 KTS. ..JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/JLT
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1208 PM EST SUN FEB 24 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL BRING OCCASIONAL SNOW SHOWERS THROUGH THE
AFTERNOON WITH ONLY VERY LIGHT ACCUMULATIONS. EXPECT A DRY DAY ON
MONDAY AS HIGH PRESSURE CRESTS INTO THE EASTERN GREAT LAKES REGION.
A LARGE AREA OF LOW PRESSURE WILL APPROACH THE REGION LATE TUESDAY
WITH UNSETTLED WEATHER LASTING FROM TUESDAY NIGHT THROUGH THE END OF
THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWING A WEAK LOW FADING AWAY
OVER SOUTHERN QUEBEC AS SECONDARY COASTAL CYCLOGENESIS CONTINUES
JUST SOUTHEAST OF CAPE COD. A SHARP MID LEVEL TROUGH EVIDENT IN
WATER VAPOR IMAGERY AND OBJECTIVE RUC ANALYSIS OVER SOUTHERN ONTARIO
AND WESTERN NY AT 17Z WILL SWING EAST ACROSS THE REGION THROUGH MID
AFTERNOON AND CONTINUE TO PROVIDE A PERIOD OF LARGE SCALE ASCENT IN
THE DPVA REGION AHEAD OF THE TROUGH.
RADAR IMAGERY SHOWING RATHER WIDESPREAD LIGHT SNOW SHOWERS ACROSS
WESTERN AND CENTRAL NY AND ALSO THE EASTERN LAKE ONTARIO REGION AS
OF 17Z. THIS WILL CONTINUE INTO THE AFTERNOON...WITH A GENERAL TREND
TOWARDS TAPERING OFF FROM WEST TO EAST AS THE MID LEVEL TROUGH
CONTINUES EAST AND LARGE SCALE ASCENT ENDS.
WITH THE COLD CORE ALOFT CROSSING THE REGION THIS AFTERNOON...850MB
TEMPS DROP TO AROUND -11C. THIS MAY BE JUST COLD ENOUGH TO SUPPORT
SOME VERY LIMITED LAKE ENHANCEMENT. THIS COMBINED WITH UPSLOPE FLOW
MAY PRODUCE UP TO AN INCH OF ACCUMULATION ON THE HILLS OF THE
SOUTHERN TIER AND ALSO ACROSS THE TUG HILL REGION. ELSEWHERE ONLY A
LIGHT COATING OF ACCUMULATION IS EXPECTED...AND WITH THE NOW
STRONGER LATE FEBRUARY SUN ANGLE EXPECT MOST ROADS TO JUST REMAIN
WET.
HIGHS TODAY WILL BE IN THE UPPER 20S ACROSS THE HIGHER TERRAIN OF
THE FORECAST AREA IN THE SOUTHERN TIER AND TUG HILL...WITH LOWER 30S
ACROSS THE LOWER ELEVATIONS OF THE LAKE PLAINS AND CLOSE TO THE LAKE
ERIE SHORE. LOWS TONIGHT WILL BE IN THE LOWER 20S AWAY FROM THE
LAKES...AND IN THE MID TO UPPER 20S ALONG AND DOWNWIND OF THE LAKES
WHERE CLOUDS WILL ALSO LINGER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AT THE START OF THE PERIOD WE WILL SEE THE UPPER TROUGH SHIFTING
OFF TO OUR EAST AS THE AREA COMES UNDER THE INCREASING INFLUENCE
OF UPPER RIDGING AND HIGH PRESSURE...PUSHING EAST FROM THE GREAT
LAKES AND OHIO VALLEY. THIS WILL SUPPORT A WEAKENING TO THE
NORTHWESTERLY FLOW AND A LOWERING OF OVER-LAKE INVERSION HEIGHTS.
THIS WILL ACT TO SUPPRESS ANY LINGERING LAKE SNOW SHOWERS
SOUTHEAST OF LAKE ONTARIO. BUFR SOUNDINGS SHOWING CONSIDERABLE LOW
LEVEL MOISTURE UNDERNEATH SUBSIDENCE INVERSION AND CONSIDERING
LIGHT NORTHERLY FLOW DEVELOPING...IT MAY BE TAKE AWHILE BEFORE
CLOUDS CAN SCATTER OUT. TEMPERATURES WILL RUN NEAR NORMAL WITH
HIGHS IN THE LOWER TO MID 30S.
MONDAY NIGHT...THE CENTER OF THE SURFACE HIGH WILL MOVE OVERHEAD
THEN SHIFT EAST TO NEW ENGLAND WITH A BETTER CHANCE TO SEE
CLEARING SKIES...ALTHOUGH HIGH CLOUDS MAY BEGIN TO SLIDE OVERHEAD
ACROSS THE WEST AHEAD OF THE NEXT STORM SYSTEM.
THE TUESDAY AND TUESDAY NIGHT TIME FRAME CONTINUES TO BE THE MAIN
FORECAST CHALLENGE...AS THE COMPACT UPPER LEVEL SYSTEM EJECTS INTO
THE OHIO VALLEY. FOR THIS PACKAGE...WE WILL LEAN TOWARD TO THE
OPERATIONAL ECMWF RUN WITH INCREASING SUPPORT FROM THE GFS. THE
SYSTEM WILL BE UNDERGOING AN OCCLUSION PROCESS DURING THIS TIME
FRAME. THIS WEAKENING PROCESS WOULD OFTEN SIGNAL THAT THE
PRECIPITATION SHIELD ON THE NORTHERN SIDE OF THE UPPER LOW WILL
BE WANING...HOWEVER A WELL DEFINED CONVEYOR OF MOISTURE FROM THE
ATLANTIC WILL BE WORKING INTO THE NORTHERN OR COLD SIDE OF THE
SYSTEM. MID TROPOSPHERIC DEFORMATION ALONG THE NORTHERN FLANK OF
THE UPPER LOW IS FORECAST TO BE EXCELLENT WITHIN A HIGHLY
DIFFLUENT UPPER FLOW. THE STRONG DYNAMIC SUPPORT IS EXPECTED TO
LIFT ACROSS WESTERN AND CENTRAL NEW YORK LATE TUESDAY AND TUESDAY
NIGHT DEVELOPING WIDESPREAD PRECIPITATION. THERMAL PROFILES
SUGGESTING PRECIPITATION WILL LIKELY START AS A RAIN DUE TO THE
LATE DAYTIME ARRIVAL...ALTHOUGH A WINTRY MIX COULD BECOME
PROBLEMATIC ALONG THE SOUTHERN TIER. CONCERNS ARISE TUESDAY NIGHT
AS PRECIPITATION MAY FALL AT SUFFICIENT RATES TO CAUSE SIGNIFICANT
DIABATIC COOLING OF LOWER LAYERS ALLOWING FOR A GREATER RISK FOR
SNOW. HEAVY SNOW NOT TOTALLY OUT OF THE QUESTION FOR SOME AREAS AS
A WELL DEFINED TROWAL FEATURE EVOLVES. HOWEVER...TOP CIPS ANALOGS
WERE SHOWING GREATEST SUPPORT FOR SNOWFALL AMOUNTS TO REMAIN
BELOW WARNING CRITERIA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A BUILDING BLOCKING PATTERN CURRENTLY TAKING SHAPE OVER THE NORTH
ATLANTIC CAN BE SEEN WITHIN THE ECMWF 500MB HEMISPHERIC PLOT AND
CURRENT NEGATIVE PHASE OF THE NAO WHICH WILL MAKE FOR A SLOW-TO-MOVE
WEATHER PATTERN AT LEAST FROM MIDWEEK INTO THE WEEKEND. MODEL
ENSEMBLE FORECASTS FOR THE NAO INDEX SHOW THIS COULD PERSIST INTO
EARLY MARCH AS WELL. THE STORM SYSTEM WHICH WILL BE NEAR THE
FORECAST AREA ON WEDNESDAY WILL CONTINUE TO BRING CLOUDS AND
DIURNALLY INFLUENCED PRECIPITATION. AFTER THE INITIAL WARM FRONTAL
FORCED SLUG OF PRECIP PUSHES THROUGH TUESDAY NIGHT WE WILL SEE
MAINLY SCATTERED SHOWER ACTIVITY AS THE SYSTEM OCCLUDES TO OUR WEST
WEDNESDAY AND WEDNESDAY NIGHT WHICH THE 12Z GFS AND ECMWF AGREE
UPON.
MODELS SHOW THE SYSTEM WILL GET NUDGED EASTWARD THROUGH THURSDAY
WHERE A SLUG OF MOISTURE BENEATH THE UPPER LOW WILL LIKELY AGAIN
BRING RAIN AND SNOW ACROSS THE FORECAST AREA. P-TYPE WILL BE
DIURNALLY INFLUENCED AS DAYTIME TEMPS WILL RISE ABOVE FREEZING IN
MANY SPOTS DURING THE DAY WITH RAIN OCCURRING AND OVERNIGHT TEMPS
FALLING BACK TO NEAR OR BELOW FREEZING WHERE SNOW CAN BE EXPECTED.
FRIDAY AND SATURDAY WITH THE LOW NOW EAST OF THE LOWER LAKES SOME
COLDER AIR MOVES IN AND WITH LINGERING TROUGHINESS ALOFT WE KEPT A
CHANCE OF SNOW IN THE FORECAST. BY SATURDAY WE LOOK TO RETURN TO
BELOW NORMAL WHERE HIGHS MAY NOT BREAK ABOVE FREEZING.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
AN UPPER LEVEL LOW WILL CROSS THE REGION THIS AFTERNOON WITH
WIDESPREAD MVFR CIGS/VSBY IN LIGHT SNOW SHOWERS AND A FEW POCKETS OF
IFR VSBY IN STEADIER SNOW. THE SNOW SHOWERS ARE EXPECTED TO
GRADUALLY TAPER OFF FROM WEST TO EAST FROM MID AFTERNOON THROUGH
EARLY EVENING AS THE UPPER LEVEL DISTURBANCE EXITS THE REGION TO THE
EAST. THIS WILL LEAVE BEHIND MAINLY MVFR CIGS THROUGH THE FIRST HALF
OF TONIGHT BEFORE SLOWLY SCATTERING OUT LATE TONIGHT AND MONDAY
MORNING WITH A RETURN TO VFR IN MOST LOCATIONS...ALTHOUGH SOME
POCKETS OF MVFR CIGS WILL LIKELY LINGER THROUGH THE FIRST HALF OF
MONDAY.
OUTLOOK...
TUESDAY...MAINLY VFR.
TUESDAY NIGHT AND WEDNESDAY...IFR WITH SNOW...RAIN AND WINTRY MIX.
THURSDAY AND FRIDAY...MVFR/IFR WITH SNOW SHOWERS LIKELY.
&&
.MARINE...
A WEST WIND OVER LAKE ERIE UNDER CYCLONIC FLOW AND COLD AIR
ADVECTION ALOFT WILL STRENGTHEN TOWARDS 15 TO 20 KNOTS. A SMALL
CRAFT ADVISORY FOR LAKE ERIE WILL BE IN EFFECT THROUGH THE EARLY
EVENING. WINDS AND WAVES WILL ALSO CREATE SMALL CRAFT CONDITIONS ON
LAKE ONTARIO FROM SODUS BAY TO MEXICO BAY AND NORTH TO HENDERSON
BAY. THESE CONDITIONS WILL DEVELOP AROUND MID DAY AND PERSIST
THROUGH THE EVENING.
ON MONDAY AN AREA OF HIGH PRESSURE WILL CROSS THE LAKE WITH MINIMAL
WINDS AND WAVES ON THE LAKES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
LOZ044-045.
&&
$$
SYNOPSIS...HITCHCOCK/WCH
NEAR TERM...HITCHCOCK/WCH
SHORT TERM...TMA
LONG TERM...SMITH
AVIATION...HITCHCOCK
MARINE...WCH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1112 AM CST SUN FEB 24 2013
.DISCUSSION...
FOG WAS DISSIPATING AT A GOOD CLIP THIS MORNING OVER THE MN SIDE.
WILL CANCEL FOG ADVISORY FOR THE AREA. HOWEVER WILL HAVE PATCHY FOG
FOR THE REST OF THE MORNING ON THE MN SIDE.
FEW RETURNS ON RADAR WITH A COUPLE OBS SITES REPORTED LIGHT SNOW
OVER THE FAR NORTHWEST ZONES. WILL KEEP FLURRIES FOR THIS AFTERNOON
MAINLY ON THE ND SIDE.
ESSENTIALLY LITTLE CHANGE TO TEMPS FOR TODAY.
&&
.PREVIOUS DISCUSSION.../ISSUED 420 AM CST SUN FEB 24 2013/
CHALLENGE FOR THE FORECAST INCLUDES FOG THIS MORNING AND ITS AFFECT
TODAY ON TEMPS IN NW MN. OTHERWISE TEMPS AND CLOUD THE MAIN
CHALLENGE FOR THE FIRST PART OF THE WEEK. MODELS IN GOOD AGREEMENT
AND USED A BLEND FOR THE FORECAST PACKAGE.
HAVE INHERITED FOG ADVISORY AND NEED TO EXPEND NORTH AS OBS AT CKN AND
HCO ARE QUARTER MILE. HRRR SHOWS LOW VSBYS THRU 18Z SO WILL EXTEND IN
TIME ALSO. STRATUS DECK WILL LIFT AS 925 WINDS INCREASE AND IMPROVE
MIXING THROUGH THE MORNING HOURS SIMILAR TO SATURDAY MORNING. WEAK
SFC LOW IS EXPECTED TO CONTINUE TO MOVE ACROSS ND TODAY AND SLOWLY
WEAKEN AS LIGHT SNOW COVERAGE DIMINISHES. KEPT THE CHC POPS IN THE
DVL BASIN THRU NOON THEN WENT FLURRIES FOR THIS AFTERNOON.
MON AND TUE ARE DRY WITH CONCERN BEING CLOUD COVER AND ITS EFFECTS
ON TEMPS. 500MB SPLIT FLOW WITH SOUTHERN PLAINS CUTOFF STORM SYSTEM
AND RIDGING BUILDING INTO THE NORTHERN PLAINS WILL GIVE MORE SUN
THAN CLOUDS WITH 925 TEMPS INCREASING TO NEAR 0 BY 00Z TUE WILL GIVE
ABOVE NORMAL TEMPS TO THE AREA.
LONG TERM (WEDNESDAY-SATURDAY)...
MODELS AGREE THAT AN UPPER RIDGE
WILL BUILD ACROSS THE WESTERN CONUS THROUGH THE PERIOD. THIS WILL
PLACE A SFC RIDGE ACROSS THE REGION AND LEAD TO DRY WEATHER.
TEMPERATURES WILL BE NEAR NORMAL.
&&
.AVIATION...
FOG WAS LIFTING ACROSS THE NORTHWEST MN. SCATTERED MVFR TO IFR WAS
MOVING INTO THE WESTERN ZONES. EXPECT CIGS IN THE WEST TO RISE TO
AROUND 2 THOUSAND FT THIS AFTERNOON.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
HOPPES
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1239 PM EST SUN FEB 24 2013
.SYNOPSIS...
AN UPPER LEVEL LOW OVER THE GREAT LAKES WILL SLIDE EAST ACROSS
UPSTATE NEW YORK TODAY. A RIDGE OF HIGH PRESSURE WILL BUILD OVER
PENNSYLVANIA ON MONDAY. A STORM SYSTEM OVER THE PLAINS WILL TRACK
NORTHEAST INTO PENNSYLVANIA ON TUESDAY. THE PARENT UPPER LOW WILL
REMAIN OVER THE NORTHEAST CONUS THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FEW FLURRIES DOWN TO THE DUBOIS AREA. CURRENT FCST GOOD.
EARLIER DISCUSSION BELOW.
DRIER WESTERLY FLOW WORKING INTO CENTRAL PA EARLY THIS AM BEHIND
OCCLUDED FRONT. HOWEVER...ABUNDANT LOW LVL MOISTURE AND A CALM
WIND AHEAD OF THIS BOUNDARY CONTINUES TO RESULT IN AREAS OF FOG
ACROSS THE SUSQ VALLEY AT 11Z. LATEST 3KM HRRR SUGGESTS FOG WILL
LIFT ACROSS THE EASTERN ZONES BY ARND 13Z...AS DRIER AIR ARRIVES.
FOCUS THEN SHIFTS TOWARD UPPER LOW SLIDING EAST FROM THE GRT LKS.
LG SCALE FORCING AHEAD OF THIS FEATURE SHOULD SUPPORT SCT -SHSN
ACROSS THE W MTNS LATER TODAY...WHICH WILL LIKELY DUST THE GROUND
OVER THE HIGHER TERRAIN.
CAA AND PLENTY OF STRATO-CU SHOULD KEEP TEMPS FROM RISING MUCH
TODAY...THE EXCEPTION BEING THE LOWER SUSQ VALLEY...WHERE
DRYING/DOWNSLOPING FLOW SHOULD YIELD PTSUNNY SKIES AND TEMPS
REACHING THE M40S. A TIGHTENING PRES GRADIENT BTWN HIGH PRES OVR
THE MIDWEST AND INTENSIFYING LOW SOUTH OF NEW ENG WILL RESULT IN
AN INCREASINGLY GUSTY WNW WIND ACROSS CENTRAL PA TODAY. BUFKIT MDL
SOUNDINGS INDICATE THERE WILL BE GUSTS ARND 25KTS BY MID AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
SCT SNOW SHOWERS ACROSS THE NW MTNS SHOULD TAPER OFF THIS
EVENING...AS UPPER LOW LIFTS OUT AND INVERSION HGTS FALL. EXPECT A
GENERAL CLEARING TREND TONIGHT...AS SFC HIGH BUILDS TOWARD PA FROM
THE MIDWEST. HOWEVER...MDL SOUNDINGS INDICATE LOW LVL MOISTURE
TRAPPED BENEATH INVERSION WILL REMAIN BANKED AGAINST THE NW MTNS
THRU MUCH OF THE NIGHT.
HIGH PRES SHOULD PROVIDE MOST OF THE REGION WITH SUNNY SKIES AND
LGT WINDS MONDAY WITH TEMPS NEAR SEASONAL LEVELS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ALL MED RANGE GUIDANCE INDICATING UPPER LOW OVR THE MISS VALLEY
WILL LIFT NE TOWARD PA ON TUESDAY...PROVIDING INCREASING
CONFIDENCE IN A FAIRLY SIGNIFICANT PRECIP EVENT FOR PA WITH GEFS
MEAN QPF BTWN 0.5 AND 1 INCH. BOTH ECMWF ENSEMBLE MEAN AND GEFS MEAN
SOLUTIONS TRACK A PRIMARY SFC LOW TO OUR WEST WITH A SECONDARY
LIFTING THRU EASTERN PA. THIS SCENARIO WOULD LIKELY RESULT IN SOME
WARMER AIR WORKING IN ALOFT...RESULTING IN MIXED PRECIP TYPES.
ECMWF ENS MEAN 850 TEMPS SUPPORT THE BEST CHC OF WINTRY PRECIP OVR
THE N MTNS WITH RAIN MOST LIKELY IN THE SE.
THE BULK OF THE PRECIP SHOULD BE OVER BY WED...AS SERLY LL JET AND
PLUME OF ANOMALOUS PWATS LIFTS NORTH OF PA. HOWEVER...UNSETTLED/COOL
WX SEEMS LIKELY THRU THE END OF NEXT WEEK WITH MED RANGE MDL DATA
ALL KEEPING UPPER LOW IN THE VICINITY OF PA. ALTHOUGH AIR MASS
DOESN/T LOOK INITIALLY COLD ENOUGH FOR LAKE EFFECT...A
DEEP...MOIST NWRLY FLOW SHOULD YIELD PERSISTENT UPSLOPE SNOW
SHOWERS ACROSS THE W MTNS WED-FRI. LIGHT ACCUMS SEEM PROBABLE ESP
AT NIGHT. DAYTIME TEMPS WED-THU SHOULD GET ABV FREEZING EVERYWHERE
BASED ON ECMWF ENS MEAN 8H TEMPS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
TYPICAL POST-COLD-FRONT NORTHWEST FLOW SET UP ACROSS THE
REGION...WITH MVFR TO OCCASIONAL IFR CONDITIONS ACROSS THE
MOUNTAINS IN LOW CEILINGS AND SNOW SHOWERS...AND MAINLY VFR
ELSEWHERE. EXPECT THIS PATTERN TO CONTINUE THE REST OF THE
AFTERNOON AND MUCH OF THE TONIGHT...ALTHOUGH LIKELY TO SEE A
SLOW DIMINISHING OF SNOW SHOWER ACTIVITY IN THE WEST AS DRY AIR
MOVES INTO THE REGION.
WINDS WILL REMAIN BREEZY THROUGH THE AFTERNOON...WITH 10 TO 20
KNOT WINDS COMMON...SLOWLY DIMINISHING THIS EVENING.
VFR CONDITIONS FOR MONDAY ALL AREAS AS HIGH PRESSURE MOVES ACROSS
THE REGION.
ANOTHER SIGNIFICANT WEATHER SYSTEM WILL BRING LOWERING CONDITIONS
AND MIXED PRECIPITATION TO CENTRAL PENNSYLVANIA BEGINNING
TUESDAY...LASTING INTO WEDNESDAY.
OUTLOOK...
MON...MAINLY VFR.
TUE...DETERIORATING CONDITIONS FROM SW TO NE. MVFR TO IFR.
WED...CONTINUED MIXED PRECIPITATION...MVFR TO IFR.
THU...CONTINUING RAIN AND SNOW SHOWERS...REDUCED CIGS AND VSBYS
ESPECIALLY WEST AND CENTRAL.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD/MARTIN
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...JUNG/RXR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
307 PM CST SUN FEB 24 2013
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
306 PM CST SUN FEB 24 2013
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING FROM JUST OFF THE CALIFORNIA COAST INTO SOUTHERN
ALBERTA...A POTENT SOUTHERN STREAM UPPER LOW OVER ARIZONA AND NEW
MEXICO...RIDGING BUILDING IN THE SOUTHERN STREAM AHEAD OF IT FROM
THE LOWER MISSISSIPPI RIVER VALLEY INTO OUR FORECAST AREA...AND A
NORTHERN STREAM SHORTWAVE TROUGH CROSSING SOUTH CENTRAL CANADA AND
NORTHWEST NORTH DAKOTA. SUBSIDENCE UNDER THE SOUTHERN STREAM UPPER
RIDGE COMBINED WITH PLENTY OF DRY AIR SEEN ON THE 12Z MPX AND DVN
SOUNDINGS HAS RESULTED IN A DRY DAY ACROSS THE FORECAST AREA.
VARYING CLOUD COVER ACROSS THE AREA. HAD ONE PATCH OF CIRRUS MOVE
ACROSS TOPPING THE RIDGE. MORE IMPORTANTLY...A STRATUS DECK LINGERS
NORTHEAST OF I-94...AND TO THE SOUTHWEST A STRATUS DECK HAS BEEN
EXPANDING NORTHEAST FROM EASTERN NEBRASKA TO AUSTIN MN AND MASON
CITY IA. THE FORMER STRATUS IS RELATED TO MOISTURE STILL TRAPPED
FROM FRIDAYS STORM...EVIDENT ON THE 12Z GRB SOUNDING. THE LATTER
STRATUS IS ALONG AN INVERTED SURFACE TROUGH...WHICH EXTENDS FROM
DEEPENING LOW PRESSURE IN WEST TEXAS INTO SOUTHWEST MN. AIRMASS HAS
WARMED QUITE A BIT WITH 850MB TEMPS OF -5C AT MPX AT 12Z COMPARED TO
-10C AT 12Z YESTERDAY. THIS WARMING HAS BEEN REFLECTED BY
TEMPERATURES IN THE FORECAST AREA ABOUT 5-10 DEGREES WARMER THAN
YESTERDAY.
SHORT TERM HIGHLIGHTS / CONCERNS...
1. POTENTIAL FOR FOG AGAIN TONIGHT AND MONDAY NIGHT -
DEWPOINTS THROUGH MIXING AND SOME PARTIAL SNOW MELTING HAVE RISEN
BACK UP TO AROUND 20 F. COOLING TONIGHT...EVEN UNDER THE STRATUS
DECK EXPANDING NORTHEAST...BRINGS UP THE CONCERN OF FALLING THROUGH
THESE CROSS-OVER TEMPERATURES AND RESULTING IN FOG. SREF
PROBABILITIES OF LESS THAN 1 MILE VISIBILITY AND HRRR VISIBILITY
PROGS INDICATE FOG FORMING AGAIN...AS SOON AS 03Z AND THEN
DISSIPATING BY 15Z. BOTH SUGGEST NORTHEAST IOWA INTO FAR SOUTHWEST
WI AND ACROSS TAYLOR/CLARK COUNTIES AS THE BEST CHANCES FOR FOG. OF
THEM...THINK THE FIRST AREA WOULD HAVE THE BEST CHANCE AS THEY
SHOULD REMAIN CLEAR THE LONGEST AND BE ABLE TO GO THROUGH THE
CROSS-OVER. THERE ARE MID/HIGH CLOUDS ACROSS NEBRASKA PROGGED TO
SPREAD IN DURING THE NIGHT...WHICH SHOULD DISRUPT THE FOG PROCESS.
FEEL THERE IS ENOUGH SIGNAL HERE TO JUST GO WITH PATCHY FREEZING FOG
ACROSS THE ENTIRE AREA TONIGHT...DISSIPATING AFTER MIDNIGHT EXCEPT
OVER TAYLOR/CLARK TO MATCH THE INCOMING MID/HIGH CLOUDS. WOULD NOT
COMPLETELY RULE OUT DENSE FOG EITHER...BUT WOULD LIKE TO SEE
DEWPOINTS RIGHT NOW A LITTLE HIGHER BEFORE MENTIONING DENSE FOG.
LOOKING AHEAD TO MONDAY NIGHT...THE SREF AGAIN POINTS TO POSSIBLE
FOG FORMATION OVER THE NORTH HALF OF WISCONSIN. THERE MIGHT BE A
LITTLE BETTER CHANCE AS MOST MODELS SHOW POTENTIAL FOR PARTIAL
CLEARING AFTER MIDNIGHT. THUS...INCLUDING A MENTION OF PATCHY
FREEZING FOG OVER TAYLOR/CLARK COUNTIES.
2. LIGHT QPF SIGNALS FROM GFS/NAM/REGIONAL CANADIAN/SREF TONIGHT
THROUGH MONDAY NIGHT -
24.12Z NAM/GFS/REGIONAL CANADIAN AND 24.15Z SREF POP FORECASTS HAVE
HIGHLIGHTED AN AREA OF LIGHT QPF POSSIBLE FROM SOUTHERN MN INTO THE
NORTH HALF OF WI TONIGHT THROUGH MONDAY NIGHT. THIS LIGHT
PRECIPITATION IS RELATED TO MOISTURE STUCK AT OR BELOW 900 MB AND
WEAK LIFT GETS APPLIED TO IT. THE MOISTURE IS DEFINITELY THERE NOTED
BY THAT STRATUS DECK ALREADY OVER NORTHWEST IOWA. THE LIFT COMES
FROM TWO FEATURES. THE FIRST IS A SURFACE TROUGH ACCOMPANYING THE
CURRENT SHORTWAVE TROUGH TRACKING ACROSS SOUTH CENTRAL CANADA...
WHICH APPROACHES THE AREA MONDAY NIGHT. THE SECOND IS THAT INVERTED
TROUGH WHICH IS PROGGED TO LINGER OVER WESTERN IOWA AND SOUTHWEST
MINNESOTA. SHOULD THIS PRECIPITATION OCCUR...WE COULD BE DEALING
WITH FLURRIES AND/OR FREEZING DRIZZLE...WITH THE LATTER FAVORED MORE
FOR MONDAY NIGHT WHEN NO ICE IS PRESENT ALOFT. HOWEVER...FEEL THIS
WEAK LIFT IS OVERDONE. MOST OF THESE MODELS SUGGEST THERE SHOULD
HAVE PRECIPITATION ALREADY AND THERE HAS NOT BEEN. ADDITIONALLY...
THERE IS BASICALLY NO ISENTROPIC LIFT TO SPEAK OF ALONG THE INVERTED
TROUGH. THUS...THINKING THE LIGHT QPF MIGHT BE MORE OF A SIGNAL FOR
THE LOW CLOUDS AND FOG POTENTIAL...AND THERE WAS FOG THIS MORNING.
SO HAVE KEPT THE FORECAST DRY FOR NOW FOR TONIGHT THROUGH MONDAY
NIGHT.
3. THE SOUTHERN STREAM UPPER LOW AND DEVELOPING WINTER STORM -
MODEL TRENDS...FLIP-FLOPPING CONTINUES ON WHETHER OR NOT THE
DEFORMATION BAND ON THE NORTHWEST SIDE OF THE STORM IMPACTS PORTIONS
OF THE AREA FOR TUESDAY INTO TUESDAY NIGHT. THERE APPEARS TO BE 2
REASONS FOR THIS...ONE ON HOW MUCH THE UPPER LOW WILL DECAY AS IT
RUNS INTO THE DOWNSTREAM UPPER RIDGE...AND THE SECOND RELATED TO A
KICKER SHORTWAVE DROPPING INTO NEW MEXICO ON TUESDAY ALONG WITH THE
WAVELENGTH BETWEEN IT AND THE UPPER LOW. THE LATEST EXAMPLE OF
FLIP-FLOPPING IS THE 24.12Z NAM...WHICH THE PREVIOUS 2 RUNS WENT
MORE SOUTHEAST AND BASICALLY HAD THE AREA DRY. NOW THE 24.12Z NAM
SHIFTED NORTHWEST... PRODUCING 0.50 TO 1 INCH OF LIQUID EQUIVALENT
FROM FAYETTE COUNTY EAST TO GRANT COUNTY. THIS WOULD EASILY BE
WORTHY OF AN ADVISORY AND POSSIBLY A WARNING. LATEST 24.18Z NAM IS
SIMILAR TO THE 12Z BUT CAME DOWN A BIT QPF WISE. THE GFS HAS BEEN
ONE OF THE MORE STABLE MODELS WITH THE PAST 6 TO 8 RUNS STAYING
FAIRLY CONSISTENT...BRINGING THE BAND INTO THE SOUTHEAST 1/2 OF THE
AREA TUESDAY AFTERNOON AND LINGERING IT INTO THE DAY WEDNESDAY. THE
QPF IS NOT NEARLY AS HEAVY AS THE NAM...UP TO 0.40 INCHES...BUT
WOULD BE ADVISORY WORTHY. THE LAST FEW CANADIAN RUNS INCLUDING THE
LATEST 24.12Z RUN HAVE BEEN SIMILAR TO THE GFS. LASTLY...THE 24.12Z
RUN OF THE ECMWF SHIFTED BACK TO THE NORTHWEST TOWARDS ITS 23.12Z
RUN...COMING MORE IN-LINE WITH THE GFS AND SAYING THAT THE 24.00Z
RUN WAS A FLUKE.
FOR THE FORECAST...SINCE THE 24.12Z MODELS ARE IN PRETTY GOOD
AGREEMENT THAT OUR SOUTHEAST END WILL BE IMPACTED TUESDAY INTO
TUESDAY NIGHT...AND GIVEN THE MORE STABLE NATURE OF THE GFS/CANADIAN
IMPACTING THE SAME AREA...HAVE RAISED PRECIPITATION CHANCES. NOW THE
SYSTEM AS IT LIFTS OUT OF THE SOUTHERN PLAINS AND INTO ILLINOIS WILL
BE WEAKENING...DUE TO IT RUNNING INTO THE RIDGING BUILT UP AHEAD OF
IT AS MENTIONED EARLIER AND THE SYSTEM GOING THROUGH THE OCCLUSION
PROCESS. THUS...THE IDEA MODELS HAVE SUGGESTED OF QPF DIMINISHING
DUE TO WEAKENING FORCING ALOFT SEEMS REASONABLE. SO AT THIS TIME...
ONLY THINKING MAYBE A MINIMAL ADVISORY WOULD BE NEEDED AT MOST...FOR
FAYETTE COUNTY EAST TO GRANT COUNTY. THINGS COULD STILL CHANGE...
THOUGH. THE NORTHWEST HALF OF THE FORECAST AREA MAY NOT GET MUCH IF
ANYTHING OUT OF THIS BRUSH BY FROM THE STORM...BUT THE CYCLONIC FLOW
AND MOISTURE WRAPPING AROUND WARRANTS KEEPING SOME 20-40
PRECIPITATION CHANCES. THESE CHANCES GO INTO WEDNESDAY...THOUGH THE
24.12Z ECMWF/CANADIAN WOULD SUGGEST THE PRECIPITATION COULD END
FASTER WEST TO EAST.
OUTSIDE THE ISSUES NOTED ABOVE...DESPITE THE APPROACH OF THE STORM
SYSTEM...HIGH TEMPERATURES SHOULD CLIMB UP TO AROUND NORMAL. PART OF
THIS IS DUE TO THE 925MB TEMPS HOLDING AROUND -4C EACH DAY...ABOUT 2
C WARMER THAN TODAY. THE SECOND IS THAT EVEN IF WE HAVE TO DEAL WITH
CLOUD ISSUES...THE HIGHER SUN ANGLE CAN HELP MIX BETTER NOW. MEDFORD
WI IS A GOOD EXAMPLE TODAY MANAGING TO HIT 30F DESPITE HAVING LOW
CLOUDS AROUND ALL DAY AND 925MB TEMPS AROUND -6C.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
306 PM CST SUN FEB 24 2013
THE LONG TERM FORECAST CONTINUES TO LOOK QUIET. GOOD MODEL AGREEMENT
CONTINUES AMONGST THE 24.12Z ECMWF/GFS/CANADIAN AND ECMWF
ENSEMBLES...WHICH SHOW RIDGING BUILDING UP OVER THE WESTERN U.S.
THROUGH SATURDAY WHILE TROUGHING HANGS IN PLACE OVER THE EASTERN
U.S.. THE FORECAST AREA IS CAUGHT IN THE MIDDLE BETWEEN THE
TWO...FAVORING A RIDGE OF HIGH PRESSURE WHICH SLOWLY BUILDS EAST
INTO THE FORECAST AREA DURING THIS PERIOD. THERE ARE INDICATIONS OF
A SHORTWAVE TROUGH DROPPING SOUTH THROUGH THE AREA ON FRIDAY...BUT
THERE ARE BOTH UNCERTAINTIES EXACTLY ON WHERE IT TRACKS AND WHETHER
IT WILL HAVE ENOUGH MOISTURE TO PRODUCE PRECIPITATION. THEREFORE...
AFTER SOME LINGERING SMALL PRECIPITATION CHANCES OVER WISCONSIN
AREAS WEDNESDAY NIGHT ASSOCIATED WITH THE SLOWLY DEPARTING AND
WEAKENING STORM TO OUR EAST...HAVE A DRY FORECAST FOR THURSDAY INTO
SATURDAY. HEADING INTO SUNDAY...A MORE POTENT SHORTWAVE TROUGH LOOKS
TO CRASH THROUGH THE WESTERN U.S. RIDGE...BUT ONLY MAKE IT INTO THE
NORTHERN ROCKIES BY 00Z MONDAY. IT SHOULD BE ENOUGH TO PUSH SOME OF
THE UPPER RIDGE EAST...ALLOWING THE SURFACE HIGH PRESSURE RIDGE TO
AT LEAST MOVE OVER IF NOT SHIFT OFF TO THE EAST FORECAST AREA.
NEEDLESS TO SAY...ANOTHER DRY DAY IS ANTICIPATED SUNDAY.
TEMPERATURES ARE A LITTLE TOUGH GIVEN A NORTHERLY FLOW PRESENT WHICH
BRINGS DOWN SOME COOLER AIR FOR MUCH OF THE PERIOD. HOWEVER...IT IS
NOT THAT COLD...NOTED BY 850MB TEMPS AT MOST DROPPING TO -8 TO -12C
BY FRIDAY. ANY SUNSHINE THAT OCCURS...WHICH MORE COULD HAPPEN IF THE
ECMWF IS RIGHT...WILL ALLOW FOR GOOD MIXING. THUS HAVE LEFT A
CONSENSUS APPROACH WHICH YIELDS HIGHS JUST SLIGHTLY BELOW NORMAL.
&&
.AVIATION...THROUGH 18Z MONDAY
1143 AM CST SUN FEB 24 2013
MAIN AVIATION CONCERNS ARE ON AN AREA OF IFR/MVFR
STRATUS...CURRENTLY OVER MUCH OF WESTERN IOWA...EXPANDING
NORTHEAST THIS AFTERNOON INTO THIS EVENING. THE STRATUS DECK IS
EXPECTED TO MOVE OVER KRST BY 2130Z THIS AFTERNOON WITH CEILINGS
LOWERING TO 1500FT...THEN LOWERING FURTHER TO 500 FT BY 00Z.
ALSO...THERE ARE VISIBILITY RESTRICTIONS OCCURRING UNDER THIS SO
PLAN ON VISIBILITIES LOWERING TO 4SM. CONDITIONS WILL CONTINUE TO
DETERIORATE THROUGH THE EVENING HOURS AND BY 03Z CEILINGS LOOK TO
LOWER TO 200FT WITH VISIBILITIES LOWERING TO 3SM. THESE CONDITIONS
WILL PERSIST AT KRST THROUGH THE OVERNIGHT HOURS WITH IMPROVEMENTS
EXPECTED AROUND 14Z. THE BULK OF THE STRATUS DECK SHOULD REMAIN
JUST NORTHEAST OF KLSE THROUGH THE EVENING HOURS...THEN
POTENTIALLY EXPANDING TO THE SOUTHEAST. PLAN ON CEILINGS LOWERING
TO 1500 FT AT KLSE AROUND 11Z. WINDS WILL BE LIGHT AND GENERALLY
OUT OF THE SOUTH/SOUTHEAST THROUGH THE FORECAST PERIOD AT 3 TO 7
KTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
306 PM CST SUN FEB 24 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1143 AM CST SUN FEB 24 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
318 AM CST SUN FEB 24 2013
THE MAIN FOCUS THROUGH THE EARLY PART OF NEXT WEEK IS WITH THE
NEXT STORM SYSTEM THAT WILL TRACK INTO THE REGION AND BRING THE
POSSIBILITY OF SOME SNOW ALONG WITH IT.
CURRENTLY...SKIES HAVE CLEARED THROUGH MUCH OF THE REGION WITH THE
MAIN EXCEPTION BEING ACROSS NORTHERN WISCONSIN WHERE AN INVERTED
SURFACE TROUGH LINGERS NEAR THE UPPER GREAT LAKES. A SURFACE RIDGE
AXIS RUNS FROM THE TRIPLE POINT OF NORTH/SOUTH DAKOTA AND
MINNESOTA DOWN INTO CENTRAL ILLINOIS AND IS WHERE TEMPERATURES
HAVE DROPPED ENOUGH TO PRODUCE SOME POCKETS OF SHALLOW GROUND FOG.
A FEW SITES IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA HAVE BRIEFLY
GONE DOWN TO A 1/2SM...BUT HAVE JUST AS QUICKLY IMPROVED DUE TO
THE SHALLOW NATURE OF THIS FOG. WITH THE 24.07Z RAP SHOWING THIS
RIDGE AXIS NOT MAKING IT EAST OF THE RIVER UNTIL MID MORNING...AM
NOT EXPECTING MUCH IN THE WAY OF WIDESPREAD FOG IN THIS REGION.
MAY HAVE TO TRIM BACK SOME OF THE FREEZING FOG ADVISORY OVER THE
NEXT FEW HOURS WITH THE CHOPPING BLOCK LIKELY BEING WITH ANY
COUNTIES ALONG AND EAST OF THE MISSISSIPPI RIVER. EVEN IN THE
AREAS WHERE THE FOG DOES OCCUR...IMPACTS ARE EXPECTED TO BE
MINIMAL WITH THE SHORT DURATION OF IT...IF IT EVEN OCCURS. WITH
THE RIDGE AXIS OVER THE REGION TODAY...EXPECT A DECENT DAY WITH
MAINLY SUNNY SKIES AND HIGHS RIGHT AROUND NORMAL.
THIS RIDGE AXIS WILL LINGER ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY INTO MONDAY BEFORE THE NEXT SYSTEM MOVES IN FROM THE
SOUTHWEST AND ESCORTS IT OFF TO THE NORTH BY TUESDAY. THE TREND
FOR THIS NEXT SYSTEM APPEARS TO STILL BE THE SAME WITH THE MORE
SOUTHERLY TRACK THAT KEEPS MUCH OF THE HEAVIER SNOW TO THE SOUTH
OF THE FORECAST AREA. THE 24.00Z NAM/GFS/ECMWF ARE ALL FAIRLY
CLOSE WITH THE TRACK AND TIMING OF THE LOW RUNNING FROM SOUTH
CENTRAL MISSOURI TUESDAY MORNING ON INTO CENTRAL INDIANA BY
TUESDAY EVENING. THE 24.00Z NAM SEEMS TO BE A LITTLE UNDERDONE ON
ITS QPF AS BUFKIT SOUNDINGS OUT OF DBQ SHOW A FULLY SATURATED
SOUNDING FROM LATE TUESDAY AFTERNOON INTO THE OVERNIGHT HOURS BUT
QPF IS 0.00 THERE. HOWEVER...JUST TO THE NORTHWEST OF THAT AREA AT
ALO AND BLR...THESE SAME SOUNDINGS SHOW A SUBSTANTIAL DRY LAYER
THAT WILL NEED TO BE OVERCOME FROM THE SURFACE ON UP TO 700MB. DUE
TO THIS DRY LAYER...AM CONCERNED THAT THE SNOW FROM THIS SYSTEM
MAY NOT MAKE IT VERY FAR TO THE NORTHWEST OF THE MAIN BAND THAT IS
EXPECTED TO BE IN EASTERN IOWA/NORTHERN ILLINOIS. HAVE KEPT THE
CHANCES FOR SNOW GOING FOR THE TIME BEING...BUT THEY MAY HAVE TO
GET TRIMMED BACK IF THE 24.00Z NAM/ECMWF SOUTHEAST TREND HOLDS
FIRM.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
318 AM CST SUN FEB 24 2013
CONFIDENCE IS SOMEWHAT LOW WITH HOW LONG THE LIGHT SNOW MAY HOLD
ON ACROSS THE REGION AS THE TAIL END OF THE SYSTEM MOVES THROUGH.
THERE ARE DIFFERING OPINIONS ON WHERE THE INVERTED SURFACE TROUGH
SETS UP WITH THE 24.00Z ECMWF KEEPING THE AREA DRY THROUGH THE
REST OF THE WEEK WHILE THE 24.00Z GFS/GEM KEEPS SOME LIGHT SNOW IN
THROUGH THURSDAY. KEPT SOME SMALL CHANCES IN THERE FOR NOW INTO
EARLY THURSDAY MORNING...BUT AS MENTIONED FOR TUESDAY...CONFIDENCE
IN HOW FAR NORTHWEST THE SNOW MAKES IT IS PRETTY LOW AT THIS
POINT. DESPITE NORTHERLY FLOW ALOFT AND AT THE SURFACE...THERE IS
NOT MUCH OF A COLD SOURCE OF AN AIR MASS ACROSS CANADA TO PULL ANY
COLD AIR DOWN FROM...SO TEMPERATURES WILL REMAIN AT OR JUST BELOW
NORMAL THROUGH MUCH OF THE NEXT WEEK.
&&
.AVIATION...THROUGH 18Z MONDAY
1143 AM CST SUN FEB 24 2013
MAIN AVIATION CONCERNS ARE ON AN AREA OF IFR/MVFR
STRATUS...CURRENTLY OVER MUCH OF WESTERN IOWA...EXPANDING
NORTHEAST THIS AFTERNOON INTO THIS EVENING. THE STRATUS DECK IS
EXPECTED TO MOVE OVER KRST BY 2130Z THIS AFTERNOON WITH CEILINGS
LOWERING TO 1500FT...THEN LOWERING FURTHER TO 500 FT BY 00Z.
ALSO...THERE ARE VISIBILITY RESTRICTIONS OCCURRING UNDER THIS SO
PLAN ON VISIBILITIES LOWERING TO 4SM. CONDITIONS WILL CONTINUE TO
DETERIORATE THROUGH THE EVENING HOURS AND BY 03Z CEILINGS LOOK TO
LOWER TO 200FT WITH VISIBILITIES LOWERING TO 3SM. THESE CONDITIONS
WILL PERSIST AT KRST THROUGH THE OVERNIGHT HOURS WITH IMPROVEMENTS
EXPECTED AROUND 14Z. THE BULK OF THE STRATUS DECK SHOULD REMAIN
JUST NORTHEAST OF KLSE THROUGH THE EVENING HOURS...THEN
POTENTIALLY EXPANDING TO THE SOUTHEAST. PLAN ON CEILINGS LOWERING
TO 1500 FT AT KLSE AROUND 11Z. WINDS WILL BE LIGHT AND GENERALLY
OUT OF THE SOUTH/SOUTHEAST THROUGH THE FORECAST PERIOD AT 3 TO 7
KTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
725 AM CST SUN FEB 24 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH/RRS
LONG TERM....HALBACH
AVIATION...WETENKAMP