Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/28/15
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1205 AM MST THU FEB 26 2015
.UPDATE...
ISSUED AT 1203 AM MST THU FEB 26 2015
QUICK UPDATE TO PRECIPITATION FORECAST THROUGH THE EARLY MORNING
HOURS. SHOWERS HAVE TAPERED OFF EXCEPT FOR A FEW ISO SHOWERS OVER
THE CENTRAL MTNS OF WESTERN CO AND THE SAN JUANS. WEATHER SHOULD
BE RELATIVELY QUIET UNTIL AROUND NOON THURSDAY.
UPDATE ISSUED AT 646 PM MST WED FEB 25 2015
SCATTERED SNOW SHOWERS HAVE BEEN SPILLING INTO THE WEST CENTRAL
VALLEYS. HRRR MODEL SHOWING SNOW SHOWER ACTIVITY MOVING INTO
MONTROSE LATER THIS EVENING. BOOSTED VALLEY POPS THIS EVENING TO
REFLECT CURRENT SHORT TERM TRENDS.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 330 PM MST WED FEB 25 2015
MOIST...UNSTABLE CONDITIONS HAVE KEPT SNOW SHOWERS GOING ALL DAY
ACROSS WESTERN COLORADO AND THIS WILL CONTINUE INTO THE LATE
EVENING HOURS. THE COOL ADVECTIVE NORTHWEST FLOW IS FAVORING MANY
NORTH AND WEST FACING ASPECTS FROM THE FLAT TOPS AND NORTHERN
PLATEAUS TO THE NORTHERN SAN JUANS. WEBCAMS SHOW THE INTENSITY OF
THE CONVECTIVE SNOW SHOWERS WITH VISIBILITIES DROPPING QUICKLY AS
SNOW RATES INCREASE. HOWEVER LOOKING AT AREA WEB CAMS ROADWAYS ARE
STAYING IN FAIRLY GOOD SHAPE...EVEN OVER THE HIGHER PASSES.
SNOTELS HAVE PICKED UP THIS AFTERNOON WITH THE ADDED OCTANE BUT
STILL THE MAJORITY ARE IN THE 2 TO 4 INCH RANGE. SNOW STAKES SHOW
THE SAME AT LOCAL SKI AREAS. WATER VAPOR IMAGERY INDICATES THE
WAVE DRIVING THESE SHOWERS IS DROPPING ACROSS SOUTHWEST WYOMING
LATE THIS AFTERNOON AND WILL BE SHEARING ACROSS THE COLORADO UTAH
BORDER THROUGH THE EVENING. THOUGH SOME BOOST WILL BE LOST AT
SUNSET SHOWERS SHOULD CONTINUE ACROSS THE CENTRAL AND SOUTHERN
MOUNTAINS THROUGH LATE EVENING...ENDING OVERNIGHT. SOME SHOWERS
ARE LIKELY TO LEAK INTO THE LOWER VALLEYS OF WESTERN COLORADO
ALONG I-70 AND NORTHWARD AS WELL BUT LITTLE ACCUMULATION IS
EXPECTED. SUBSIDENCE AND INCREASING STABILITY IN THE TRANSITION
AREA BETWEEN THE DEPARTING WAVE AND THE NEXT ENERGY DIGGING TO OUR
WEST LOOKS TO BRING A RATHER SIGNIFICANT BREAK THURSDAY MORNING
FOR OUR CWA. LIGHT OROGRAPHIC SNOW SHOWERS COULD REMAIN OVER THE
DIVIDE MOUNTAINS OVER THE NEXT 24 HOURS AS DENDRITIC TEMPERATURES
AT MOUNTAIN TOP LEVEL WILL BE IN THE SWEET SPOT. ADDITIONAL LIGHT
ACCUMULATIONS WILL BE POSSIBLE BUT SNOW RATES NOT EXCESSIVE. HIGH
LEVEL MOISTURE WILL BEGIN TO MAKE IT/S WAY BACK INTO THE GREAT
BASIN THROUGH THE DAY AS ANOTHER UPSTREAM WAVE MOVES THROUGH THE
NORTHWEST FLOW INTO THE GREAT BASIN. INSTABILITY WILL BE PRESENT
BUT NOT QUITE AS ROBUST AS THIS AFTERNOON AND JET SUPPORT RETREATS
TO THE WEST. EXPECT INCREASING POPS MAINLY ON THE TERRAIN ON
THURSDAY AFTERNOON WITH SOME DECREASE IN ACTIVITY AT SUNSET.
THURSDAY NIGHT THE WAVE TAKES A TIGHTER CYCLONIC CURVE ACROSS THE
4 CORNERS AS THE UPPER JET BEGINS TO CURVE ALOFT. THIS WILL LIKELY
KEEP SOME SNOW GOING IN THE HILLS FAVORING THE SOUTHERN CWA
THROUGH THE NIGHT BUT AGAIN ONLY LIGHT ACCUMULATIONS ARE EXPECTED.
UPSTREAM ACROSS THE LEFT COAST FROM SO.CAL NORTHWARD...300K
SURFACES SHOW A HEALTHY SURGE OF PACIFIC MOISTURE BEING
TRANSPORTED INLAND AS OUR WEATHER MAKER FOR THE WEEKEND DROPS
ACROSS THE PACIFIC NORTHWEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM MST WED FEB 25 2015
WELCOME TO WEEKEND STORM NUMBER TWO UNDER THIS NEW IMPROVED
WEATHER PATTERN. THIS STORM IS NOTABLE FOR ITS EXTENDED PERIOD OF
PERSISTENT SHOWERS...PERHAPS THROUGH NEXT WEDNESDAY.
THE FIRST OF TWO PACIFIC TROUGHS SLIDES DOWN THE WEST COAST
EVENTUALLY CLOSING OFF ALONG THE SOUTHERN CALIFORNIA COAST BY
SUNDAY. DESCENT MOISTURE AND GOOD OROGRAPHICS WITH PERIODS OF
UPPER LEVEL SUPPORT SHOULD PRODUCE GOOD SNOWFALL FROM THE FOUR
CORNERS NE TO THE WEST ELK MOUNTAINS. A WINTER STORM WATCH HAS
BEEN ISSUED FOR THESE ZONES.
FRIDAY-FRIDAY NIGHT...IN MILD WARM MOIST ADVECTION...SHOWERS WILL
INCREASE ACROSS THE SOUTH. OROGRAPHICS WILL FAVOR SW-FACING
SLOPES.
SATURDAY-SATURDAY NIGHT THE PATTERN AMPLIFIES AS THE LOW DIGS
DOWN THE COAST. THE 120KT JET OVER NEW MEXICO LIFTS ACROSS THE SAN
JUAN MTNS INTO THE WEST ELKS. 700MB WINDS INCREASE TO 40KTS UNDER
THE JET. A SURFACE-700MB LOW DEEPENS IN SE UTAH ADDING TO THE
OROGRAPHIC COMPONENT INTO THE SOUTHERN MOUNTAIN SLOPES. 700MB
TEMPERATURES AROUND -4C WOULD PRODUCE AFTERNOON SNOW LEVELS
AROUND 7KFT. THE JET SHIFTS EAST ON SUNDAY FOR SOME DIMINISHING OF
THE MOUNTAIN WINDS BUT MOIST OROGRAPHIC SNOW REMAINS IN PLACE.
FOR MONDAY THE 18Z GFS HAS SLOWED DOWN TO MATCH THE EC TIMING WITH
THE PROGRESSION OF THIS FIRST LOW OFF TO THE SE. THE SFC LOW
LIFTS THROUGH THE SOUTH THRU THE DAY. A DOWN TURN OF SHOWERS IS
EXPECTED MONDAY NIGHT AND WE HAVE ENDED THE WINTER STORM WATCH
HERE.
BUT ALREADY BY TUESDAY A COLDER TROUGH HAS DIVED DOWN THE COAST
SETTLING OVER THE GREAT BASIN. A STRONG COLD FRONT PASSES ON
TUESDAY DRIVING SNOW LEVELS TO THE LOWEST ELEVATIONS AND
EFFICIENTLY TURNING ANY AVAILABLE MOISTURE TO SNOW. TUESDAY NIGHT
INTO WEDNESDAY THE FLOW TURNS TO COLD ADVECTIVE NORTH WITH SNOW
LINGERING ALONG THE NORTH-FACING SLOPES BUT STILL FAVORING THE
SOUTH WHERE MOISTURE IS DEEPEST. HIGHLIGHTS ARE EXPECTED WITH THIS
SECOND LOW ALSO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1042 PM MST WED FEB 25 2015
SCATTERED SHOWERS CONTINUE ACROSS WEST CENTRAL COLORADO AND THE
SOUTHWESTERN COLORADO MOUNTAINS. SHOWERS ARE EXPECTED TO TAPER OFF
BY 12Z THURSDAY MORNING. VFR CONDITIONS EXPECTED BETWEEN 12Z AND
18Z THURSDAY...BUT MORE SNOW WILL DEVELOP OVER WESTERN COLORADO
(MAINLY IN THE MOUNTAINS) AFTER 18Z INCLUDING KASE...KEGE...AND
KTEX. ALL TAF SITES HAVE A CHANCE OF RECEIVING PRECIPITATION AFTER
00Z THURSDAY EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WATCH FROM FRIDAY MORNING THROUGH MONDAY EVENING
FOR COZ012-014-018-019-022-023.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...15
LONG TERM...JOE
AVIATION...JAM
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1046 PM MST WED FEB 25 2015
.UPDATE...
ISSUED AT 646 PM MST WED FEB 25 2015
SCATTERED SNOW SHOWERS HAVE BEEN SPILLING INTO THE WEST CENTRAL
VALLEYS. HRRR MODEL SHOWING SNOW SHOWER ACTIVITY MOVING INTO
MONTROSE LATER THIS EVENING. BOOSTED VALLEY POPS THIS EVENING TO
REFLECT CURRENT SHORT TERM TRENDS.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 330 PM MST WED FEB 25 2015
MOIST...UNSTABLE CONDITIONS HAVE KEPT SNOW SHOWERS GOING ALL DAY
ACROSS WESTERN COLORADO AND THIS WILL CONTINUE INTO THE LATE
EVENING HOURS. THE COOL ADVECTIVE NORTHWEST FLOW IS FAVORING MANY
NORTH AND WEST FACING ASPECTS FROM THE FLAT TOPS AND NORTHERN
PLATEAUS TO THE NORTHERN SAN JUANS. WEBCAMS SHOW THE INTENSITY OF
THE CONVECTIVE SNOW SHOWERS WITH VISIBILITIES DROPPING QUICKLY AS
SNOW RATES INCREASE. HOWEVER LOOKING AT AREA WEB CAMS ROADWAYS ARE
STAYING IN FAIRLY GOOD SHAPE...EVEN OVER THE HIGHER PASSES.
SNOTELS HAVE PICKED UP THIS AFTERNOON WITH THE ADDED OCTANE BUT
STILL THE MAJORITY ARE IN THE 2 TO 4 INCH RANGE. SNOW STAKES SHOW
THE SAME AT LOCAL SKI AREAS. WATER VAPOR IMAGERY INDICATES THE
WAVE DRIVING THESE SHOWERS IS DROPPING ACROSS SOUTHWEST WYOMING
LATE THIS AFTERNOON AND WILL BE SHEARING ACROSS THE COLORADO UTAH
BORDER THROUGH THE EVENING. THOUGH SOME BOOST WILL BE LOST AT
SUNSET SHOWERS SHOULD CONTINUE ACROSS THE CENTRAL AND SOUTHERN
MOUNTAINS THROUGH LATE EVENING...ENDING OVERNIGHT. SOME SHOWERS
ARE LIKELY TO LEAK INTO THE LOWER VALLEYS OF WESTERN COLORADO
ALONG I-70 AND NORTHWARD AS WELL BUT LITTLE ACCUMULATION IS
EXPECTED. SUBSIDENCE AND INCREASING STABILITY IN THE TRANSITION
AREA BETWEEN THE DEPARTING WAVE AND THE NEXT ENERGY DIGGING TO OUR
WEST LOOKS TO BRING A RATHER SIGNIFICANT BREAK THURSDAY MORNING
FOR OUR CWA. LIGHT OROGRAPHIC SNOW SHOWERS COULD REMAIN OVER THE
DIVIDE MOUNTAINS OVER THE NEXT 24 HOURS AS DENDRITIC TEMPERATURES
AT MOUNTAIN TOP LEVEL WILL BE IN THE SWEET SPOT. ADDITIONAL LIGHT
ACCUMULATIONS WILL BE POSSIBLE BUT SNOW RATES NOT EXCESSIVE. HIGH
LEVEL MOISTURE WILL BEGIN TO MAKE IT/S WAY BACK INTO THE GREAT
BASIN THROUGH THE DAY AS ANOTHER UPSTREAM WAVE MOVES THROUGH THE
NORTHWEST FLOW INTO THE GREAT BASIN. INSTABILITY WILL BE PRESENT
BUT NOT QUITE AS ROBUST AS THIS AFTERNOON AND JET SUPPORT RETREATS
TO THE WEST. EXPECT INCREASING POPS MAINLY ON THE TERRAIN ON
THURSDAY AFTERNOON WITH SOME DECREASE IN ACTIVITY AT SUNSET.
THURSDAY NIGHT THE WAVE TAKES A TIGHTER CYCLONIC CURVE ACROSS THE
4 CORNERS AS THE UPPER JET BEGINS TO CURVE ALOFT. THIS WILL LIKELY
KEEP SOME SNOW GOING IN THE HILLS FAVORING THE SOUTHERN CWA
THROUGH THE NIGHT BUT AGAIN ONLY LIGHT ACCUMULATIONS ARE EXPECTED.
UPSTREAM ACROSS THE LEFT COAST FROM SO.CAL NORTHWARD...300K
SURFACES SHOW A HEALTHY SURGE OF PACIFIC MOISTURE BEING
TRANSPORTED INLAND AS OUR WEATHER MAKER FOR THE WEEKEND DROPS
ACROSS THE PACIFIC NORTHWEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM MST WED FEB 25 2015
WELCOME TO WEEKEND STORM NUMBER TWO UNDER THIS NEW IMPROVED
WEATHER PATTERN. THIS STORM IS NOTABLE FOR ITS EXTENDED PERIOD OF
PERSISTENT SHOWERS...PERHAPS THROUGH NEXT WEDNESDAY.
THE FIRST OF TWO PACIFIC TROUGHS SLIDES DOWN THE WEST COAST
EVENTUALLY CLOSING OFF ALONG THE SOUTHERN CALIFORNIA COAST BY
SUNDAY. DESCENT MOISTURE AND GOOD OROGRAPHICS WITH PERIODS OF
UPPER LEVEL SUPPORT SHOULD PRODUCE GOOD SNOWFALL FROM THE FOUR
CORNERS NE TO THE WEST ELK MOUNTAINS. A WINTER STORM WATCH HAS
BEEN ISSUED FOR THESE ZONES.
FRIDAY-FRIDAY NIGHT...IN MILD WARM MOIST ADVECTION...SHOWERS WILL
INCREASE ACROSS THE SOUTH. OROGRAPHICS WILL FAVOR SW-FACING
SLOPES.
SATURDAY-SATURDAY NIGHT THE PATTERN AMPLIFIES AS THE LOW DIGS
DOWN THE COAST. THE 120KT JET OVER NEW MEXICO LIFTS ACROSS THE SAN
JUAN MTNS INTO THE WEST ELKS. 700MB WINDS INCREASE TO 40KTS UNDER
THE JET. A SURFACE-700MB LOW DEEPENS IN SE UTAH ADDING TO THE
OROGRAPHIC COMPONENT INTO THE SOUTHERN MOUNTAIN SLOPES. 700MB
TEMPERATURES AROUND -4C WOULD PRODUCE AFTERNOON SNOW LEVELS
AROUND 7KFT. THE JET SHIFTS EAST ON SUNDAY FOR SOME DIMINISHING OF
THE MOUNTAIN WINDS BUT MOIST OROGRAPHIC SNOW REMAINS IN PLACE.
FOR MONDAY THE 18Z GFS HAS SLOWED DOWN TO MATCH THE EC TIMING WITH
THE PROGRESSION OF THIS FIRST LOW OFF TO THE SE. THE SFC LOW
LIFTS THROUGH THE SOUTH THRU THE DAY. A DOWN TURN OF SHOWERS IS
EXPECTED MONDAY NIGHT AND WE HAVE ENDED THE WINTER STORM WATCH
HERE.
BUT ALREADY BY TUESDAY A COLDER TROUGH HAS DIVED DOWN THE COAST
SETTLING OVER THE GREAT BASIN. A STRONG COLD FRONT PASSES ON
TUESDAY DRIVING SNOW LEVELS TO THE LOWEST ELEVATIONS AND
EFFICIENTLY TURNING ANY AVAILABLE MOISTURE TO SNOW. TUESDAY NIGHT
INTO WEDNESDAY THE FLOW TURNS TO COLD ADVECTIVE NORTH WITH SNOW
LINGERING ALONG THE NORTH-FACING SLOPES BUT STILL FAVORING THE
SOUTH WHERE MOISTURE IS DEEPEST. HIGHLIGHTS ARE EXPECTED WITH THIS
SECOND LOW ALSO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1042 PM MST WED FEB 25 2015
SCATTERED SHOWERS CONTINUE ACROSS WEST CENTRAL COLORADO AND THE
SOUTHWESTERN COLORADO MOUNTAINS. SHOWERS ARE EXPECTED TO TAPER OFF
BY 12Z THURSDAY MORNING. VFR CONDITIONS EXPECTED BETWEEN 12Z AND
18Z THURSDAY...BUT MORE SNOW WILL DEVELOP OVER WESTERN COLORADO
(MAINLY IN THE MOUNTAINS) AFTER 18Z INCLUDING KASE...KEGE...AND
KTEX. ALL TAF SITES HAVE A CHANCE OF RECEIVING PRECIPITATION AFTER
00Z THURSDAY EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WATCH FROM FRIDAY MORNING THROUGH MONDAY EVENING
FOR COZ012-014-018-019-022-023.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...15
LONG TERM...JOE
AVIATION...JAM
AREA FORECAST DISCUSSION
NWS NEW YORK NY
941 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE TRACKS TO THE SOUTHEAST TODAY. HIGH PRESSURE BUILDS
FROM THE WEST TONIGHT THROUGH SATURDAY. THE HIGH THEN SLIDES
OFFSHORE FROM SATURDAY NIGHT INTO SUNDAY. A COLD FRONT APPROACHES
FROM THE NORTHWEST LATE SUNDAY...THEN CROSSES THE AREA SUNDAY
NIGHT AND EARLY MONDAY...WITH WAVES OF LOW PRESSURE RIDING ALONG
THE FRONT. HIGH PRESSURE BUILDS IN BEHIND THE FRONT INTO TUESDAY.
ANOTHER STORM SYSTEM IMPACTS THE AREA TUESDAY NIGHT AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE LOW PASSES WELL TO THE SE TODAY WHILE A SHORTWAVE ALOFT
SHIFTS THROUGH INTO EARLY AFTERNOON. BEST ASSOCIATED LIFT WILL BE
TO THE SOUTH. LOW LEVELS HAVING TROUBLE MOISTENING UP AS EVIDENCED
BY RADAR AND SURFACE OBS. HRRR AND RAP CONTINUE TO SHOW FOR THE
PAST FEW RUNS THAT MOST OF WHAT REACHES THE SURFACE REMAINS
OFFSHORE. HAVE LOWERED POPS FROM SLIGHT CHC NW TO CHC SE.
WITH COLD AIR IN PLACE...NORTH TO NORTHEAST WINDS AND PLENTY OF
CLOUD COVER WILL PREVENT TEMPS FROM RISING MUCH TODAY. BLENDED
MAV/MET AND 12Z ECS STATISTICAL MOS OVER HI RES NMM BACKGROUND.
EXPECT HIGH TEMPS GENERALLY IN THE LOWER TO MID 20S. THIS REMAIN
20 DEGREES BELOW NORMAL LEVELS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WEAKENING UPPER TROUGH EXTENDING FROM NE TO SW ACROSS THE GREAT
LAKES REGION MAKES SLOW PROGRESS EAST...WEAKENING AS IT DOES SO. MID
AND HIGH LEVEL MOISTURE WILL TRANSLATE TO LEFTOVER CLOUDS TONIGHT
AND INTO FRIDAY AS THIS FEATURE SLOWLY PROGRESSES EAST.
AT THE SURFACE...PREVAILING NORTHERLY FLOW CONTINUES AS RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE WEST.
DRY WEATHER IS ANTICIPATED...ALTHOUGH CANNOT COMPLETELY RULE OUT A
FLURRY OR TWO DUE TO THE MID/UPPER LEVEL TROUGH APPROACHING.
TEMPS REMAIN COLD THROUGH FRIDAY. BLENDED MOS ONCE AGAIN. LOWS
TONIGHT WILL RANGE FROM THE SINGLE DIGITS ACROSS THE INTERIOR TO THE
TEENS ELSEWHERE. ON FRIDAY...TEMPS RISE TO THE MIDDLE 20S. STILL
QUITE COLD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF WITH HIGH PRESSURE BUILDING INTO THE
REGION FRIDAY NIGHT AND SATURDAY...THEN MOVING OFFSHORE SATURDAY
NIGHT AND SUNDAY MORNING. EXPECT DRY CONDITIONS THROUGH THIS PERIOD.
A COLD FRONT AND MID LEVEL SHORTWAVE APPROACH LATE SUNDAY AND MOVE
ACROSS THE REGION EARLY MONDAY MORNING. WE SHOULD MAINLY SEE ALL
SNOW...WITH POSSIBLY A WINTRY MIX ALONG THE COAST. FOR
SIMPLICITY...KEEPING PRECIPITATION ALL SNOW FOR NOW. IF
PRECIPITATION LINGERS INTO MONDAY AFTERNOON OVER EASTERN
ZONES...THEN THE BOUNDARY LAYER COULD WARM ENOUGH TO CHANGE THINGS
TO PLAIN RAIN BEFORE ENDING.
MONDAY NIGHT WILL BE DRY UNDER NW FLOW ALOFT AND HIGH PRESSURE
PASSING OVER THE REGION.
ANOTHER STORM SYSTEM IMPACTS THE REGION TUESDAY INTO WEDNESDAY.
THERE ARE SOME MODEL DIFFERENCES WITH THIS SYSTEM WITH RESPECT TO
THE TRACK OF THE SURFACE LOW AND THE LOCATION OF ITS ASSOCIATED
FRONTAL BOUNDARIES. WILL CONTINUE...FOR SIMPLICITY PURPOSES...NOT TO
ADDRESS THE SLEET OR FREEZING RAIN POTENTIAL AT THIS TIME.
TEMPERATURES ARE EXPECTED TO REMAIN BELOW NORMAL SATURDAY AND
SUNDAY...WITH A RETURN TO NEAR NORMAL ON MONDAY. TEMPERATURES FALL
BACK BELOW NORMAL ON TUESDAY...WITH TEMPERATURES APPROACHING NORMAL
ONCE AGAIN ON WEDNESDAY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE PASSES WELL TO THE SE TODAY. HIGH PRESSURE BUILDS IN
TONIGHT.
VFR THROUGH THE TAF PERIOD. REMOVED TEMPO FOR -SN FROM ALL BUT
KISP AND KJFK...AND RAISED THOSE TO VFR. IF CURRENT TRENDS
HOLD...COULD REMOVE THOSE IN FUTURE TAFS. CEILINGS GENERALLY 5-9
THOUSAND FEET THROUGH TAF PERIOD.
N-NE WINDS 8-13 KT DURING THE MORNING AND AFTERNOON...DIMINISHING
THIS EVENING.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: WIND DIRECTION VARYING FROM 010-040 TRUE
(020-050 MAGNETIC) INTO THIS AFTERNOON. OCCASIONAL GUSTS TO 20KT
POSSIBLE THROUGH EARLY AFTERNOON. LOW CHANCE MVFR CEILINGS INTO
EARLY AFTERNOON.
KLGA FCSTER COMMENTS: WIND DIRECTION VARYING FROM 020-050 TRUE
(030-060 MAGNETIC) INTO THIS AFTERNOON. OCCASIONAL GUSTS TO 20KT
POSSIBLE THROUGH EARLY AFTERNOON. VERY LOW CHANCE MVFR CEILINGS
INTO EARLY AFTERNOON.
KEWR FCSTER COMMENTS: OCCASIONAL GUSTS TO 20KT POSSIBLE THROUGH
EARLY AFTERNOON. VERY LOW CHANCE MVFR CEILINGS INTO EARLY
AFTERNOON.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: OCCASIONAL GUSTS TO 20KT POSSIBLE THROUGH
EARLY AFTERNOON. VERY LOW CHANCE MVFR CEILINGS INTO EARLY
AFTERNOON.
KHPN FCSTER COMMENTS: OCCASIONAL GUSTS TO 20KT POSSIBLE THROUGH
EARLY AFTERNOON. VERY LOW CHANCE MVFR CEILINGS INTO EARLY
AFTERNOON.
KISP FCSTER COMMENTS: OCCASIONAL GUSTS TO 20KT POSSIBLE THROUGH
EARLY AFTERNOON. LOW CHANCE MVFR CEILINGS INTO EARLY AFTERNOON.
.OUTLOOK FOR 12Z FRI THROUGH MON...
.FRIDAY-SUNDAY...VFR.
.SUNDAY NIGHT-MONDAY...CHANCE MVFR IN LIGHT SNOW...POSSIBLY MIXED
WITH RAIN SOUTHERN TERMINALS.
&&
.MARINE...
AN AREA OF LOW PRESSURE OFF THE MID ATLANTIC COAST THIS MORNING WILL
PASS TO THE SOUTHEAST OF THE WATERS TODAY. ISSUED A SCA EARLIER
FOR THE OCEAN WATERS AFTER COLLABORATION WITH SURROUNDING OFFICES.
WINDS...ESPECIALLY ACROSS THE OUTER PORTION OF THE ZONES WELL
SOUTH OF LONG ISLAND...WILL COME CLOSE TO 25 KT. IN
ADDITION...SEAS PER WAVE WATCH BUILD TO 5 FEET FOR THE OFFSHORE
BUOYS. BORDERLINE...BUT SCA ALREADY IN EFFECT FOR THE WATERS OFF
NJ AND NEW ENGLAND...SO WILL FOLLOW FOR CONTINUITY. LIGHT FREEZING
SPRAY IS EXPECTED DUE TO COLD WATER...COLD AIR TEMPS...ROUGH SEAS
AND 15 KT WINDS.
BY TONIGHT...THE LOW PASSES WELL TO THE EAST AS A RIDGE OF HIGH
PRESSURE BUILDS FROM THE WEST. PERSISTENT NORTHERLY WINDS
CONTINUE...BUT LIGHTEN. DO NOT ANTICIPATE WIND SPEEDS CLOSE TO SCA
CRITERIA TONIGHT AND FRIDAY. THE BIGGEST QUESTION IS WHAT HAPPENS TO
OCEAN SEAS. GUIDANCE SUGGESTS SEAS SUBSIDE TONIGHT...BUT BUILD CLOSE
TO 5 FEET YET AGAIN TOWARD FRIDAY MORNING DUE TO E/SE SWELL. NOT TOO
SURE ABOUT THIS...SO NO PLANS AT THIS TIME TO EXTEND THE SCA. IF
ANYTHING...A SCA FOR HAZARDOUS SEAS MAY BE NEEDED LATE TONIGHT
THROUGH FRIDAY.
FOR THE WATERS SURROUNDING LONG ISLAND...WINDS REMAIN BELOW 25
KT...AND SEAS REMAIN RATHER TRANQUIL. SPEAKING OF SEAS...MANY OF
THE BAYS REMAIN FROZEN...AND THAT IS NOT GOING TO CHANGE ANYTIME
SOON.
SCA LEVEL SEAS COULD LINGER ON THE COASTAL OCEAN WATERS EAST OF
MORICHES INLET FRIDAY NIGHT...OTHERWISE SUB-SMALL CRAFT ADVISORY
CONDITIONS ARE EXPECTED ON ALL WATERS FROM FRIDAY NIGHT INTO SUNDAY.
INCREASING SW WINDS ARE EXPECTED TO BUILD SEAS TO SCA LEVELS ON THE
COASTAL OCEAN WATERS LATE SUNDAY INTO MONDAY. NW FLOW BEHIND A COLD
FRONT COULD PRODUCE GUSTS TO SMALL CRAFT LEVELS ON ALL WATERS ON
MONDAY.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION EXPECTED THROUGH SATURDAY.
THERE IS THE POTENTIAL FOR LIGHT TO POSSIBLY MODERATE LIQUID
EQUIVALENT TO FALL FROM SUNDAY INTO MONDAY. AT THIS TIME NO
SIGNIFICANT PRECIPITATION IS EXPECTED.
ICE WILL CONTINUE TO DEVELOP ON LOCAL AREA RIVERS AND STREAMS AS
TEMPS REMAIN WELL BELOW AVERAGE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...PW/BC
NEAR TERM...JC/PW
SHORT TERM...PW
LONG TERM...BC
AVIATION...MALOIT/DS
MARINE...PW/BC
HYDROLOGY...PW/BC
AREA FORECAST DISCUSSION
NWS ALBANY NY
657 AM EST THU FEB 26 2015
.SYNOPSIS...
A STORM PASSING OFF THE MID ATLANTIC COAST MAY ALLOW FOR
SOME FLURRIES OR SNOW SHOWERS TODAY...MAINLY FOR AREAS SOUTH AND
EAST OF ALBANY. OTHERWISE...DRY WEATHER IS EXPECTED THROUGH
SATURDAY...BUT IT WILL REMAIN RATHER FRIGID. A STORM SYSTEM LOOKS TO
BRING SOME LIGHT SNOW TO THE REGION LATE SUNDAY INTO MONDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 641 AM EST...AN AREA OF LOW PRESSURE IS SITUATED ALONG THE
COAST OF THE CAROLINAS...AND IS MOVING NORTHEAST OUT TOWARDS THE
WESTERN ATLANTIC OCEAN. A LARGE SHIELD OF CLOUDS ASSOCIATED WITH
THIS SYSTEM HAVE MOVED UP THE EASTERN SEABOARD...ALTHOUGH THE
COLDEST/DEEPEST CLOUD COVER IS LOCATED SOUTHEAST OF OUR AREA.
STILL...SKIES ARE CLOUDY OVER MUCH OF OUR AREA THANKS TO A JET
STREAK ASSOCIATED WITH THIS STORM SYSTEM...AND THIS LOOKS TO
CONTINUE THROUGH THE MORNING HOURS.
AS THE STORM CONTINUES TO MOVE NORTHEAST TODAY...SOME MOISTURE
WILL MOVE UP THE COAST. IT LOOKS LIKE MOST OF THIS WILL MISS OUR
AREA TO THE SOUTH AND EAST...BUT WE CANNOT RULE OUT SOME VERY
LIGHT SNOW SHOWERS OCCURRING ACROSS SOUTHEASTERN PARTS OF THE CWA.
THE 10Z 3KM HRRR SUGGEST THE MOST LIKELY TIME FOR THIS TO OCCUR
WOULD BE BETWEEN 13Z AND 18Z. HOWEVER...THE NEAREST REPORTING SITE
SHOWING SNOW IS OVER MARYLAND...SO DESPITE RADAR RETURNS SHOWING
SOME SNOW OVER SOUTHERN NY AND NORTHERN NJ...IT SEEMS THAT THE
VERY DRY AIR AT LOW LEVELS IS WINNING OUT SO FAR THIS MORNING...AS
PRECIP IS DRYING UP BEFORE IT REACHES THE SURFACE. WITH DEWPOINTS
IN THE SINGLE DIGITS ABOVE AND BELOW ZERO...MOST OF THE QPF SHOWN
IN THE MODELS WON/T REACH THE GROUND. WE HAVE GONE WITH SLIGHT TO
LOW CHC POPS FOR SOUTHERN AREAS FOR THIS MORNING INTO EARLY THIS
AFTN...WITH A LIGHT DUSTING OF SNOW POSSIBLE...BUT IT WOULDN/T BE
SURPRISING TO SEE ANY SNOW THAT OCCURS IN OUR AREA TO BE JUST
FLURRIES WITH NO ACCUMULATION AT ALL.
IN ADDITION...A WEAK NORTHERN STREAM DISTURBANCE WILL BE MOVING
ACROSS THE UPPER GREAT LAKES LATER TODAY AND WILL BE APPROACHING
SOUTHERN CANADA BY EARLY EVENING. A SNOW SHOWER OR TWO THANKS TO
THIS SYSTEM IS POSSIBLE FOR NORTHWESTERN AREAS...MAINLY FOR THE
LATE DAY HOURS. MOISTURE IS ALSO LACKING WITH THIS SYSTEM...SO
ANY SNOW WOULD BE VERY LIGHT...AND LITTLE TO NO ACCUMULATION IS
EXPECTED WITH ACTIVITY AS WELL.
OTHERWISE...SKIES LOOK TO REMAIN CLOUDY THROUGH MUCH OF THE DAY.
TEMPS WILL REMAIN COOL...WITH 850 HPA TEMPS IN THE -11 TO -18
DEGREE C RANGE. MAX TEMPS LOOK TO MAINLY BE IN THE TEENS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
WITH THE UPPER LEVEL SHORTWAVE SLIDING BY TO THE NORTH...THERE
MAY BE A SNOW SHOWER THIS EVENING...MAINLY ACROSS THE ADIRONDACKS.
OTHERWISE...IT LOOKS TO BE DRY TONIGHT...ALTHOUGH A FAIR AMOUNT
OF CLOUDS WILL REMAIN IN PLACE. DESPITE THE CLOUDS...THE ARCTIC
AIR MASS IN PLACE WILL CONTINUE TO KEEP TEMPS RATHER COLD. MINS
WILL GENERALLY BE ZERO TO 10...ALTHOUGH THE CATSKILLS...MOHAWK
VALLEY...AND SRN GREEN MOUNTAINS WILL SEE TEMPS O TO -10 F...WITH
READINGS -5 TO -15 F OVER THE ADIRONDACKS. WINDS LOOK VERY LIGHT
TO CALM...SO NO WIND CHILL CONCERNS FOR TONIGHT.
CLOUDS WILL BREAK FOR SUNSHINE ON FRIDAY AS SFC HIGH PRESSURE
OVER GREAT LAKES AND OHIO VALLEY RIDGES INTO THE NORTHEAST. THIS
WILL CONTINUE TO ALLOW FOR DRY BUT CHILLY WEATHER. TEMPS ON FRIDAY
WILL ONCE AGAIN ONLY BE IN THE TEENS TO LOW 20S.
ANOTHER VERY COLD NIGHT IS EXPECTED FOR FRIDAY NIGHT. WITH
CLEARING SKIES...TEMPS MAY BE A LITTLE COLDER THAN THURSDAY
NIGHT...WITH BELOW ZERO READINGS FOR MOST LOCATIONS. TEMPS COULD
BE AS COLD AS -15 F OVER THE ADIRONDACKS. WITH THE HIGH PRESSURE
JUST OFF TO THE SOUTHWEST...THERE PROBABLY WON/T BE TOO MUCH
WIND...EXCEPT AT THE HIGHER ELEVATIONS. WIND CHILL VALUES MAY
APPROACH ADVISORY CRITERIA OVER THESE HIGHER ELEVATION AREAS...SO
WILL MENTION THIS IN THE HWO STATEMENT. WINDS SHOULD REMAIN LIGHT
IN ENOUGH IN VALLEY AREAS /5 MPH OR LESS/ TO NOT REQUIRE WIND
CHILL HEADLINES...BUT WE WILL CONTINUE TO MONITOR THIS CLOSELY.
IT WILL BE CONTINUED DRY ON SATURDAY...AS THE HIGH PRESSURE AREA
MOVES BY TO THE SOUTH OVER THE MID ATLANTIC. MOSTLY SUNNY SKIES
ARE EXPECTED ON SATURDAY. TEMPS WILL BE A LITTLE WARMER...WITH
HIGHS IN THE MID TEENS TO MID 20S. ANOTHER VERY COLD NIGHT IS
EXPECTED FOR SAT NIGHT...WITH LOWS 5 BELOW TO 5 ABOVE. ALTHOUGH
SKIES WILL START OFF CLEAR...SOME MID/HIGH LEVEL CLOUDS MAY START
TO INCREASE TOWARDS DAYBREAK SUNDAY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE...HOWEVER NOT SIGNIFICANTLY
BELOW NORMAL LIKE HAS BEEN THE CASE FOR THE PAST COUPLE OF WEEKS.
WILL HAVE AN ACTIVE NORTHERN STREAM WITH A SYSTEM CROSSING THE
REGION SUNDAY INTO MONDAY AND ANOTHER FOR MID WEEK.
A LIGHT SNOWFALL...GENERALLY LESS THAN 4 INCHES...IS EXPECTED SUNDAY
AFTERNOON INTO MONDAY MORNING AS A LOW PRESSURE SYSTEM APPROACHES AND
CROSSES THE REGION.
A SECONDARY COLD FRONT IS EXPECTED TO SWEEP ACROSS THE REGION MONDAY
MORNING BRINGING A REINFORCING SHOT OF COLDER AIR INTO THE REGION.
SURFACE HIGH PRESSURE IS EXPECTED TO BEGIN TO BUILD IN MONDAY
AFTERNOON AND SHIFT EASTWARD ACROSS THE REGION THROUGH TUESDAY
MORNING. ALOFT RIDGING IS EXPECTED TO DEVELOP AS A DEEP TROUGH
DIGGING OVER THE WESTERN CONUS. THIS WILL RESULT IN A COLD NIGHT
MONDAY WITH LOWS MAINLY IN THE SINGLE DIGITS.
AS THE TROUGH CONTINUES TO DEEPEN AND SHIFTS/MOVES EASTWARD A LOW
PRESSURE SYSTEM WILL DEVELOP AND WITH BROAD SOUTHWEST ACROSS THE
EASTERN CONUS HEAD TOWARD THE NORTHEAST. PRECIPITATION ASSOCIATED
WITH THE SYSTEM IS ANTICIPATED TO BEGIN TO OVERSPREAD THE REGION
TUESDAY AFTERNOON AND CONTINUE THROUGH WEDNESDAY. THERE ARE
DIFFERENCES IN THE GUIDANCE WITH THE TIMING AND EXACT TRACK OF THE
SYSTEM SO HAVE RESTRICTED POPS TO CHANCE. THE OTHER CONCERN IS THE
THERMAL PROFILE. INITIALLY SNOW IS EXPECTED HOWEVER TEMPERATURES MAY
WARM UP ENOUGH FOR RAIN ESPECIALLY UP THE HUDSON VALLEY. HOW MUCH
QPF THERE WILL BE IS HIGHLY UNCERTAINTY AT THIS TIME.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
RIDGING OVER THE REGION WILL WEAKEN SOME TODAY AS A POTENT
SOUTHERN STREAM LOW PRESSURE SYSTEM MOVES OFF THE SOUTHEAST COAST
THIS MORNING AND TRACKS EAST-NORTHEAST OUT TO SEA. RIDGING WILL
BUILD BACK IN AS THE STORM MOVES FARTHER AWAY FROM THE COAST
TONIGHT.
CLOUDS ASSOCIATED WITH THE SYSTEM WILL CONTINUE TO OVERSPREAD THE
REGION THICKENING AND LOWERING. THE PRECIPITATION SHIELD ASSOCIATED
WITH THE STORM IS EXPECTED TO EXTENT IN THE LOWER/MID HUDSON VALLEY
AND SOUTHERN NEW ENGLAND. HOWEVER THE ATMOSPHERE IS RATHER DRY SO
ONLY SOME LIGHT SNOW IS EXPECTED. IN ADDITION FLURRIES ARE POSSIBLE
AS AN UPPER TROUGH AXIS APPROACHES AS NORTHERN STREAM ENERGY MOVES
INTO THE LONGWAVE TROUGH DEEPENING IT OVER THE EASTERN UNITED STATES.
MVFR CONDITIONS ARE EXPECTED AT KPOU BY EARLY THIS AFTERNOON WITH
SOME LIGHT SNOW. MVFR CEILINGS ARE EXPECTED TO DEVELOP FOR A PERIOD
BY THIS AFTERNOON INTO THE EVENING WITH SOME FLURRIES.
LIGHT MAINLY NORTHERLY WINDS.
OUTLOOK...
FRI-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUN: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE AFTERNOON.
SUN NIGHT: HIGH OPERATIONAL IMPACT. SN LIKELY.
MON: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE MORNING.
&&
.HYDROLOGY...
A FEW SNOW SHOWERS OR FLURRIES ARE POSSIBLE FOR FAR SOUTHEASTERN
AREAS ON THURSDAY...BUT TOTAL LIQUID EQUIVALENT WILL GENERALLY
ONLY BE A FEW HUNDREDTHS OF AN INCH AT MOST. OTHERWISE...IT WILL
REMAIN DRY THROUGH SUNDAY MORNING. SOME LIGHT SNOWFALL IS
POSSIBLE FOR THE REGION LATE SUNDAY THROUGH MONDAY MORNING.
TEMPERATURES WILL REMAIN BELOW FREEZING THROUGH SUNDAY NIGHT.
TEMPERATURES MAY BRIEFLY RISE ABOVE FREEZING DURING THE DAY ON
MONDAY. WITH THE CONTINUED COLD CONDITIONS IN PLACE...ICE WILL
CONTINUE TO STRENGTHEN AND THICKEN ON AREA RIVERS...STREAMS...LAKES...AND
PONDS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
641 AM EST THU FEB 26 2015
.SYNOPSIS...
A STORM PASSING OFF THE MID ATLANTIC COAST MAY ALLOW FOR
SOME FLURRIES OR SNOW SHOWERS TODAY...MAINLY FOR AREAS SOUTH AND
EAST OF ALBANY. OTHERWISE...DRY WEATHER IS EXPECTED THROUGH
SATURDAY...BUT IT WILL REMAIN RATHER FRIGID. A STORM SYSTEM LOOKS TO
BRING SOME LIGHT SNOW TO THE REGION LATE SUNDAY INTO MONDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 641 AM EST...AN AREA OF LOW PRESSURE IS SITUATED ALONG THE
COAST OF THE CAROLINAS...AND IS MOVING NORTHEAST OUT TOWARDS THE
WESTERN ATLANTIC OCEAN. A LARGE SHIELD OF CLOUDS ASSOCIATED WITH
THIS SYSTEM HAVE MOVED UP THE EASTERN SEABOARD...ALTHOUGH THE
COLDEST/DEEPEST CLOUD COVER IS LOCATED SOUTHEAST OF OUR AREA.
STILL...SKIES ARE CLOUDY OVER MUCH OF OUR AREA THANKS TO A JET
STREAK ASSOCIATED WITH THIS STORM SYSTEM...AND THIS LOOKS TO
CONTINUE THROUGH THE MORNING HOURS.
AS THE STORM CONTINUES TO MOVE NORTHEAST TODAY...SOME MOISTURE
WILL MOVE UP THE COAST. IT LOOKS LIKE MOST OF THIS WILL MISS OUR
AREA TO THE SOUTH AND EAST...BUT WE CANNOT RULE OUT SOME VERY
LIGHT SNOW SHOWERS OCCURRING ACROSS SOUTHEASTERN PARTS OF THE CWA.
THE 10Z 3KM HRRR SUGGEST THE MOST LIKELY TIME FOR THIS TO OCCUR
WOULD BE BETWEEN 13Z AND 18Z. HOWEVER...THE NEAREST REPORTING SITE
SHOWING SNOW IS OVER MARYLAND...SO DESPITE RADAR RETURNS SHOWING
SOME SNOW OVER SOUTHERN NY AND NORTHERN NJ...IT SEEMS THAT THE
VERY DRY AIR AT LOW LEVELS IS WINNING OUT SO FAR THIS MORNING...AS
PRECIP IS DRYING UP BEFORE IT REACHES THE SURFACE. WITH DEWPOINTS
IN THE SINGLE DIGITS ABOVE AND BELOW ZERO...MOST OF THE QPF SHOWN
IN THE MODELS WON/T REACH THE GROUND. WE HAVE GONE WITH SLIGHT TO
LOW CHC POPS FOR SOUTHERN AREAS FOR THIS MORNING INTO EARLY THIS
AFTN...WITH A LIGHT DUSTING OF SNOW POSSIBLE...BUT IT WOULDN/T BE
SURPRISING TO SEE ANY SNOW THAT OCCURS IN OUR AREA TO BE JUST
FLURRIES WITH NO ACCUMULATION AT ALL.
IN ADDITION...A WEAK NORTHERN STREAM DISTURBANCE WILL BE MOVING
ACROSS THE UPPER GREAT LAKES LATER TODAY AND WILL BE APPROACHING
SOUTHERN CANADA BY EARLY EVENING. A SNOW SHOWER OR TWO THANKS TO
THIS SYSTEM IS POSSIBLE FOR NORTHWESTERN AREAS...MAINLY FOR THE
LATE DAY HOURS. MOISTURE IS ALSO LACKING WITH THIS SYSTEM...SO
ANY SNOW WOULD BE VERY LIGHT...AND LITTLE TO NO ACCUMULATION IS
EXPECTED WITH ACTIVITY AS WELL.
OTHERWISE...SKIES LOOK TO REMAIN CLOUDY THROUGH MUCH OF THE DAY.
TEMPS WILL REMAIN COOL...WITH 850 HPA TEMPS IN THE -11 TO -18
DEGREE C RANGE. MAX TEMPS LOOK TO MAINLY BE IN THE TEENS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
WITH THE UPPER LEVEL SHORTWAVE SLIDING BY TO THE NORTH...THERE
MAY BE A SNOW SHOWER THIS EVENING...MAINLY ACROSS THE ADIRONDACKS.
OTHERWISE...IT LOOKS TO BE DRY TONIGHT...ALTHOUGH A FAIR AMOUNT
OF CLOUDS WILL REMAIN IN PLACE. DESPITE THE CLOUDS...THE ARCTIC
AIR MASS IN PLACE WILL CONTINUE TO KEEP TEMPS RATHER COLD. MINS
WILL GENERALLY BE ZERO TO 10...ALTHOUGH THE CATSKILLS...MOHAWK
VALLEY...AND SRN GREEN MOUNTAINS WILL SEE TEMPS O TO -10 F...WITH
READINGS -5 TO -15 F OVER THE ADIRONDACKS. WINDS LOOK VERY LIGHT
TO CALM...SO NO WIND CHILL CONCERNS FOR TONIGHT.
CLOUDS WILL BREAK FOR SUNSHINE ON FRIDAY AS SFC HIGH PRESSURE
OVER GREAT LAKES AND OHIO VALLEY RIDGES INTO THE NORTHEAST. THIS
WILL CONTINUE TO ALLOW FOR DRY BUT CHILLY WEATHER. TEMPS ON FRIDAY
WILL ONCE AGAIN ONLY BE IN THE TEENS TO LOW 20S.
ANOTHER VERY COLD NIGHT IS EXPECTED FOR FRIDAY NIGHT. WITH
CLEARING SKIES...TEMPS MAY BE A LITTLE COLDER THAN THURSDAY
NIGHT...WITH BELOW ZERO READINGS FOR MOST LOCATIONS. TEMPS COULD
BE AS COLD AS -15 F OVER THE ADIRONDACKS. WITH THE HIGH PRESSURE
JUST OFF TO THE SOUTHWEST...THERE PROBABLY WON/T BE TOO MUCH
WIND...EXCEPT AT THE HIGHER ELEVATIONS. WIND CHILL VALUES MAY
APPROACH ADVISORY CRITERIA OVER THESE HIGHER ELEVATION AREAS...SO
WILL MENTION THIS IN THE HWO STATEMENT. WINDS SHOULD REMAIN LIGHT
IN ENOUGH IN VALLEY AREAS /5 MPH OR LESS/ TO NOT REQUIRE WIND
CHILL HEADLINES...BUT WE WILL CONTINUE TO MONITOR THIS CLOSELY.
IT WILL BE CONTINUED DRY ON SATURDAY...AS THE HIGH PRESSURE AREA
MOVES BY TO THE SOUTH OVER THE MID ATLANTIC. MOSTLY SUNNY SKIES
ARE EXPECTED ON SATURDAY. TEMPS WILL BE A LITTLE WARMER...WITH
HIGHS IN THE MID TEENS TO MID 20S. ANOTHER VERY COLD NIGHT IS
EXPECTED FOR SAT NIGHT...WITH LOWS 5 BELOW TO 5 ABOVE. ALTHOUGH
SKIES WILL START OFF CLEAR...SOME MID/HIGH LEVEL CLOUDS MAY START
TO INCREASE TOWARDS DAYBREAK SUNDAY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE...HOWEVER NOT SIGNIFICANTLY
BELOW NORMAL LIKE HAS BEEN THE CASE FOR THE PAST COUPLE OF WEEKS.
WILL HAVE AN ACTIVE NORTHERN STREAM WITH A SYSTEM CROSSING THE
REGION SUNDAY INTO MONDAY AND ANOTHER FOR MID WEEK.
A LIGHT SNOWFALL...GENERALLY LESS THAN 4 INCHES...IS EXPECTED SUNDAY
AFTERNOON INTO MONDAY MORNING AS A LOW PRESSURE SYSTEM APPROACHES AND
CROSSES THE REGION.
A SECONDARY COLD FRONT IS EXPECTED TO SWEEP ACROSS THE REGION MONDAY
MORNING BRINGING A REINFORCING SHOT OF COLDER AIR INTO THE REGION.
SURFACE HIGH PRESSURE IS EXPECTED TO BEGIN TO BUILD IN MONDAY
AFTERNOON AND SHIFT EASTWARD ACROSS THE REGION THROUGH TUESDAY
MORNING. ALOFT RIDGING IS EXPECTED TO DEVELOP AS A DEEP TROUGH
DIGGING OVER THE WESTERN CONUS. THIS WILL RESULT IN A COLD NIGHT
MONDAY WITH LOWS MAINLY IN THE SINGLE DIGITS.
AS THE TROUGH CONTINUES TO DEEPEN AND SHIFTS/MOVES EASTWARD A LOW
PRESSURE SYSTEM WILL DEVELOP AND WITH BROAD SOUTHWEST ACROSS THE
EASTERN CONUS HEAD TOWARD THE NORTHEAST. PRECIPITATION ASSOCIATED
WITH THE SYSTEM IS ANTICIPATED TO BEGIN TO OVERSPREAD THE REGION
TUESDAY AFTERNOON AND CONTINUE THROUGH WEDNESDAY. THERE ARE
DIFFERENCES IN THE GUIDANCE WITH THE TIMING AND EXACT TRACK OF THE
SYSTEM SO HAVE RESTRICTED POPS TO CHANCE. THE OTHER CONCERN IS THE
THERMAL PROFILE. INITIALLY SNOW IS EXPECTED HOWEVER TEMPERATURES MAY
WARM UP ENOUGH FOR RAIN ESPECIALLY UP THE HUDSON VALLEY. HOW MUCH
QPF THERE WILL BE IS HIGHLY UNCERTAINTY AT THIS TIME.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
RIDGING OVER THE REGION WILL WEAKEN SOME TODAY AS A POTENT
SOUTHERN STREAM LOW PRESSURE SYSTEM MOVES OFF THE SOUTHEAST COAST
THIS MORNING AND TRACKS EAST-NORTHEAST OUT TO SEA. RIDGING WILL
BUILD BACK IN AS THE STORM MOVES FARTHER AWAY FROM THE COAST
TONIGHT.
CLOUDS ASSOCIATED WITH THE SYSTEM WILL CONTINUE TO OVERSPREAD THE
REGION THICKENING AND LOWERING. THE PRECIPITATION SHIELD ASSOCIATED
WITH THE STORM IS EXPECTED TO EXTEND IN THE LOWER/MID HUDSON
VALLEY AND SOUTHERN NEW ENGLAND. HOWEVER THE ATMOSPHERE IS RATHER
DRY SO ONLY SOME LIGHT SNOW IS EXPECTED. IN ADDITION FLURRIES ARE
POSSIBLE AS AN UPPER TROUGH AXIS APPROACHES AS NORTHERN STREAM
ENERGY MOVES INTO THE LONGWAVE TROUGH DEEPENING IT OVER THE
EASTERN UNITED STATES.
MVFR CONDITIONS ARE EXPECTED AT KPOU LATER THIS MORNING INTO THE
AFTERNOON. MVFR CEILINGS ARE EXPECTED TO DEVELOP FOR A PERIOD BY
THIS AFTERNOON INTO THE EVENING. LIGHT AND VARIABLE WINDS.
OUTLOOK...
FRI-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUN: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE AFTERNOON.
SUN NIGHT: HIGH OPERATIONAL IMPACT. SN LIKELY.
MON: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE MORNING.
&&
.HYDROLOGY...
A FEW SNOW SHOWERS OR FLURRIES ARE POSSIBLE FOR FAR SOUTHEASTERN
AREAS ON THURSDAY...BUT TOTAL LIQUID EQUIVALENT WILL GENERALLY
ONLY BE A FEW HUNDREDTHS OF AN INCH AT MOST. OTHERWISE...IT WILL
REMAIN DRY THROUGH SUNDAY MORNING. SOME LIGHT SNOWFALL IS
POSSIBLE FOR THE REGION LATE SUNDAY THROUGH MONDAY MORNING.
TEMPERATURES WILL REMAIN BELOW FREEZING THROUGH SUNDAY NIGHT.
TEMPERATURES MAY BRIEFLY RISE ABOVE FREEZING DURING THE DAY ON
MONDAY. WITH THE CONTINUED COLD CONDITIONS IN PLACE...ICE WILL
CONTINUE TO STRENGTHEN AND THICKEN ON AREA RIVERS...STREAMS...LAKES...AND
PONDS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
627 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE TRACKS TO THE SOUTHEAST TODAY. HIGH PRESSURE BUILDS
FROM THE WEST TONIGHT THROUGH SATURDAY. THE HIGH THEN SLIDES
OFFSHORE FROM SATURDAY NIGHT INTO SUNDAY. A COLD FRONT APPROACHES
FROM THE NORTHWEST LATE SUNDAY...THEN CROSSES THE AREA SUNDAY
NIGHT AND EARLY MONDAY...WITH WAVES OF LOW PRESSURE RIDING ALONG
THE FRONT. HIGH PRESSURE BUILDS IN BEHIND THE FRONT INTO TUESDAY.
ANOTHER STORM SYSTEM IMPACTS THE AREA TUESDAY NIGHT AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THERE APPEARS TO BE GENERAL MODEL AGREEMENT ON OVERALL FEATURES
THROUGH TODAY. ALOFT...WEAK SHORTWAVE TRAVERSES QUICKLY SW TO
NE...PASSING JUST SOUTH OF THE AREA. SFC LOW PRESSURE OFF THE MID
ATLANTIC THIS MORNING MOVES NORTHEAST TODAY...PASSING TO THE SOUTH
OF THE 40N/70W BENCHMARK.
BEST LIFT ASSOCIATED WITH UPPER SHORTWAVE AND JET WILL REMAIN TO THE
SOUTH OF THE AREA. ANALYSIS OF HIGH RES MODELS CONTINUES TO INDICATE
LIGHT PRECIP APPROACHING CSTL ZONES THIS MORNING...WITH LIGHT PRECIP
IMPACTING CSTL ZONES FOR A SHORT PERIOD LATE THIS MORNING INTO
THE EARLY AFTERNOON. CONCERN THOUGH FOR LOW DEW POINTS THIS
MORNING...THUS PLENTY OF DRY AIR TO SATURATE.
LIGHT SNOW ACROSS SRN NJ AS OF 11Z.
SIMULATED REFLECTIVITY FROM LATEST HRRR KEEPS THE BULK OF THE
LIGHT SNOW TO THE SOUTH OF THE AREA. WRF-NMM INDICATES POTENTIAL
LIGHT SNOW CLIPPING LONG ISLAND...WITH THE BEST CHANCE FOR
MEASURABLE SNOW CSTL AND EASTERN LI AND INTO SE CT.
SPOTTY LIGHT SNOW CAN BE EXPECTED ACROSS THE INTERIOR...WITH
LOWER CHANCES FOR MEASURABLE. WILL MAINTAIN SIMILAR POPS FROM
PREVIOUS...LAYERED FROM CHANCE NW TO LIKELY EAST. TIMING OF ANY
LIGHT SNOW THAT COULD POSSIBLY MEASURE WOULD BE 14Z THROUGH 19Z.
GENERALLY UNDER AN INCH FOR CSTL LOCALES WITH PERHAPS A COATING
ELSEWHERE.
WITH COLD AIR IN PLACE...NORTH TO NORTHEAST WINDS AND PLENTY OF
CLOUD COVER WILL PREVENT TEMPS FROM RISING MUCH TODAY. BLENDED
MAV/MET AND 12Z ECS STATISTICAL MOS OVER HI RES NMM BACKGROUND.
EXPECT HIGH TEMPS GENERALLY IN THE LOWER TO MID 20S. THIS REMAIN 20
DEGREES BELOW NORMAL LEVELS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WEAKENING UPPER TROUGH EXTENDING FROM NE TO SW ACROSS THE GREAT
LAKES REGION MAKES SLOW PROGRESS EAST...WEAKENING AS IT DOES SO. MID
AND HIGH LEVEL MOISTURE WILL TRANSLATE TO LEFTOVER CLOUDS TONIGHT
AND INTO FRIDAY AS THIS FEATURE SLOWLY PROGRESSES EAST.
AT THE SURFACE...PREVAILING NORTHERLY FLOW CONTINUES AS RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE WEST.
DRY WEATHER IS ANTICIPATED...ALTHOUGH CANNOT COMPLETELY RULE OUT A
FLURRY OR TWO DUE TO THE MID/UPPER LEVEL TROUGH APPROACHING.
TEMPS REMAIN COLD THROUGH FRIDAY. BLENDED MOS ONCE AGAIN. LOWS
TONIGHT WILL RANGE FROM THE SINGLE DIGITS ACROSS THE INTERIOR TO THE
TEENS ELSEWHERE. ON FRIDAY...TEMPS RISE TO THE MIDDLE 20S. STILL
QUITE COLD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF WITH HIGH PRESSURE BUILDING INTO THE
REGION FRIDAY NIGHT AND SATURDAY...THEN MOVING OFFSHORE SATURDAY
NIGHT AND SUNDAY MORNING. EXPECT DRY CONDITIONS THROUGH THIS PERIOD.
A COLD FRONT AND MID LEVEL SHORTWAVE APPROACH LATE SUNDAY AND MOVE
ACROSS THE REGION EARLY MONDAY MORNING. WE SHOULD MAINLY SEE ALL
SNOW...WITH POSSIBLY A WINTRY MIX ALONG THE COAST. FOR
SIMPLICITY...KEEPING PRECIPITATION ALL SNOW FOR NOW. IF
PRECIPITATION LINGERS INTO MONDAY AFTERNOON OVER EASTERN
ZONES...THEN THE BOUNDARY LAYER COULD WARM ENOUGH TO CHANGE THINGS
TO PLAIN RAIN BEFORE ENDING.
MONDAY NIGHT WILL BE DRY UNDER NW FLOW ALOFT AND HIGH PRESSURE
PASSING OVER THE REGION.
ANOTHER STORM SYSTEM IMPACTS THE REGION TUESDAY INTO WEDNESDAY.
THERE ARE SOME MODEL DIFFERENCES WITH THIS SYSTEM WITH RESPECT TO
THE TRACK OF THE SURFACE LOW AND THE LOCATION OF ITS ASSOCIATED
FRONTAL BOUNDARIES. WILL CONTINUE...FOR SIMPLICITY PURPOSES...NOT TO
ADDRESS THE SLEET OR FREEZING RAIN POTENTIAL AT THIS TIME.
TEMPERATURES ARE EXPECTED TO REMAIN BELOW NORMAL SATURDAY AND
SUNDAY...WITH A RETURN TO NEAR NORMAL ON MONDAY. TEMPERATURES FALL
BACK BELOW NORMAL ON TUESDAY...WITH TEMPERATURES APPROACHING NORMAL
ONCE AGAIN ON WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE PASSES WELL TO THE SE OF THE TERMINALS TODAY. HIGH
PRESSURE BUILDS IN TONIGHT.
VFR TO START THE TAF PERIOD. LOWERING CLOUDS WITH PASSING LOW
PRESSURE MAY PRODUCE SOME LIGHT SNOW AND MVFR CIGS MAINLY FROM LATE
MORNING INTO EARLY AFTERNOON. OTHERWISE...VFR THIS EVENING INTO THE
OVERNIGHT.
N-NE WINDS 8-13 KT DURING THE MORNING AND AFTERNOON...DIMINISHING
THIS EVENING.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z. MODERATE
CONFIDENCE VFR CONDS THIS EVENING.
KLGA FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z. MODERATE
CONFIDENCE VFR CONDS THIS EVENING.
KEWR FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z. MODERATE
CONFIDENCE VFR CONDS THIS EVENING.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z. MODERATE
CONFIDENCE VFR CONDS THIS EVENING.
KHPN FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z. MODERATE
CONFIDENCE VFR CONDS THIS EVENING.
KISP FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z. MODERATE
CONFIDENCE VFR CONDS THIS EVENING.
.OUTLOOK FOR 12Z FRI THROUGH MON...
.FRI-SUNDAY...VFR.
.SUNDAY NIGHT-MON...LIGHT SNOW POSSIBLY MIXED WITH RAIN. MVFR CONDS
POSSIBLE.
&&
.MARINE...
AN AREA OF LOW PRESSURE OFF THE MID ATLANTIC COAST THIS MORNING WILL
PASS TO THE SOUTHEAST OF THE WATERS TODAY. ISSUED A SCA EARLIER
FOR THE OCEAN WATERS AFTER COLLAB WITH SURROUNDING OFFICES.
WINDS...ESPECIALLY ACROSS THE OUTER PORTION OF THE ZONES WELL
SOUTH OF LONG ISLAND...WILL COME CLOSE TO 25 KTS. IN
ADDITION...SEAS PER WAVE WATCH BUILD TO 5 FEET FOR THE OFFSHORE
BUOYS. BORDERLINE...BUT SCA ALREADY IN EFFECT FOR THE WATERS OFF
NJ AND NEW ENGLAND...SO WILL FOLLOW FOR CONTINUITY. LIGHT FREEZING
SPRAY IS EXPECTED DUE TO COLD WATER...COLD AIR TEMPS...ROUGH SEAS
AND 15 KT WINDS.
BY TONIGHT...THE LOW PASSES WELL TO THE EAST AS A RIDGE OF HIGH
PRESSURE BUILDS FROM THE WEST. PERSISTENT NORTHERLY WINDS
CONTINUE...BUT LIGHTEN. DO NOT ANTICIPATE WIND SPEEDS CLOSE TO SCA
CRITERIA TONIGHT AND FRIDAY. THE BIGGEST QUESTION IS WHAT HAPPENS TO
OCEAN SEAS. GUIDANCE SUGGESTS SEAS SUBSIDE TONIGHT...BUT BUILD CLOSE
TO 5 FEET YET AGAIN TOWARD FRIDAY MORNING DUE TO E/SE SWELL. NOT TOO
SURE ABOUT THIS...SO NO PLANS AT THIS TIME TO EXTEND THE SCA. IF
ANYTHING...A SCA FOR HAZARDOUS SEAS MAY BE NEEDED LATE TONIGHT
THROUGH FRIDAY.
FOR THE WATERS SURROUNDING LONG ISLAND...WINDS REMAIN BELOW 25
KTS...AND SEAS REMAIN RATHER TRANQUIL. SPEAKING OF SEAS...MANY OF
THE BAYS REMAIN FROZEN...AND THAT IS NOT GOING TO CHANGE ANYTIME
SOON.
SCA LEVEL SEAS COULD LINGER ON THE COASTAL OCEAN WATERS EAST OF
MORICHES INLET FRIDAY NIGHT...OTHERWISE SUB-SMALL CRAFT ADVISORY
CONDITIONS ARE EXPECTED ON ALL WATERS FROM FRIDAY NIGHT INTO SUNDAY.
INCREASING SW WINDS ARE EXPECTED TO BUILD SEAS TO SCA LEVELS ON THE
COASTAL OCEAN WATERS LATE SUNDAY INTO MONDAY. NW FLOW BEHIND A COLD
FRONT COULD PRODUCE GUSTS TO SMALL CRAFT LEVELS ON ALL WATERS ON
MONDAY.
&&
.HYDROLOGY...
A FEW HUNDREDTHS OF LIQUID EQUIVALENT IS POSSIBLE TODAY.
THERE IS THE POTENTIAL FOR LIGHT TO POSSIBLY MODERATE LIQUID
EQUIVALENT TO FALL FROM SUNDAY INTO MONDAY. AT THIS TIME NO
SIGNIFICANT PRECIPITATION IS EXPECTED.
ICE WILL CONTINUE TO DEVELOP ON LOCAL AREA RIVERS AND STREAMS AS
TEMPS REMAIN WELL BELOW AVERAGE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...BC/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...BC
AVIATION...DS
MARINE...BC/PW
HYDROLOGY...BC/PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
335 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE TRACKS TO THE SOUTHEAST TODAY. HIGH PRESSURE BUILDS
FROM THE WEST TONIGHT THROUGH SATURDAY. THE HIGH THEN SLIDES
OFFSHORE FROM SATURDAY NIGHT INTO SUNDAY. A COLD FRONT APPROACHES
FROM THE NORTHWEST LATE SUNDAY...THEN CROSSES THE AREA SUNDAY
NIGHT AND EARLY MONDAY...WITH WAVES OF LOW PRESSURE RIDING ALONG
THE FRONT. HIGH PRESSURE BUILDS IN BEHIND THE FRONT INTO TUESDAY.
ANOTHER STORM SYSTEM IMPACTS THE AREA TUESDAY NIGHT AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THERE APPEARS TO BE GENERAL MODEL AGREEMENT ON OVERALL FEATURES
THROUGH TODAY. ALOFT...WEAK SHORTWAVE TRAVERSES QUICKLY SW TO
NE...PASSING JUST SOUTH OF THE AREA. SFC LOW PRESSURE OFF THE MID
ATLANTIC THIS MORNING MOVES NORTHEAST TODAY...PASSING TO THE SOUTH
OF THE 40N/70W BENCHMARK.
BEST LIFT ASSOCIATED WITH UPPER SHORTWAVE AND JET WILL REMAIN TO THE
SOUTH OF THE AREA. ANALYSIS OF HIGH RES MODELS CONTINUES TO INDICATE
LIGHT PRECIP APPROACHING CSTL ZONES BY 12Z...WITH LIGHT PRECIP
IMPACTING CSTL ZONES FOR A SHORT PERIOD THIS MORNING INTO THE EARLY
AFTERNOON. CONCERN THOUGH FOR FALLING DEW POINTS THIS
MORNING...THUS PLENTY OF DRY AIR TO SATURATE.
SIMULATED REFLECTIVITY FROM LATEST HRRR AND WRF-NMM INDICATED
POTENTIAL LIGHT SNOW CLIPPING LONG ISLAND...WITH THE BEST CHANCE
FOR MEASURABLE SNOW CSTL AND EASTERN LI AND INTO SE CT.
SPOTTY LIGHT SNOW CAN BE EXPECTED ACROSS THE INTERIOR...WITH
LOWER CHANCES FOR MEASURABLE. WILL MAINTAIN SIMILAR POPS FROM
PREVIOUS...LAYERED FROM CHANCE NW TO LIKELY EAST. TIMING OF ANY
LIGHT SNOW THAT COULD POSSIBLY MEASURE WOULD BE 14Z THROUGH 19Z.
GENERALLY UNDER AN INCH FOR CSTL LOCALES WITH PERHAPS A COATING
ELSEWHERE.
WITH COLD AIR IN PLACE...NORTH TO NORTHEAST WINDS AND PLENTY OF
CLOUD COVER WILL PREVENT TEMPS FROM RISING MUCH TODAY. BLENDED
MAV/MET AND 12Z ECS STATISTICAL MOS OVER HI RES NMM BACKGROUND.
EXPECT HIGH TEMPS GENERALLY IN THE LOWER TO MID 20S. THIS REMAIN 20
DEGREES BELOW NORMAL LEVELS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WEAKENING UPPER TROUGH EXTENDING FROM NE TO SW ACROSS THE GREAT
LAKES REGION MAKES SLOW PROGRESS EAST...WEAKENING AS IT DOES SO. MID
AND HIGH LEVEL MOISTURE WILL TRANSLATE TO LEFTOVER CLOUDS TONIGHT
AND INTO FRIDAY AS THIS FEATURE SLOWLY PROGRESSES EAST.
AT THE SURFACE...PREVAILING NORTHERLY FLOW CONTINUES AS RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE WEST.
DRY WEATHER IS ANTICIPATED...ALTHOUGH CANNOT COMPLETELY RULE OUT A
FLURRY OR TWO DUE TO THE MID/UPPER LEVEL TROUGH APPROACHING.
TEMPS REMAIN COLD THROUGH FRIDAY. BLENDED MOS ONCE AGAIN. LOWS
TONIGHT WILL RANGE FROM THE SINGLE DIGITS ACROSS THE INTERIOR TO THE
TEENS ELSEWHERE. ON FRIDAY...TEMPS RISE TO THE MIDDLE 20S. STILL
QUITE COLD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF WITH HIGH PRESSURE BUILDING INTO THE
REGION FRIDAY NIGHT AND SATURDAY...THEN MOVING OFFSHORE SATURDAY
NIGHT AND SUNDAY MORNING. EXPECT DRY CONDITIONS THROUGH THIS PERIOD.
A COLD FRONT AND MID LEVEL SHORTWAVE APPROACH LATE SUNDAY AND MOVE
ACROSS THE REGION EARLY MONDAY MORNING. WE SHOULD MAINLY SEE ALL
SNOW...WITH POSSIBLY A WINTRY MIX ALONG THE COAST. FOR
SIMPLICITY...KEEPING PRECIPITATION ALL SNOW FOR NOW. IF
PRECIPITATION LINGERS INTO MONDAY AFTERNOON OVER EASTERN
ZONES...THEN THE BOUNDARY LAYER COULD WARM ENOUGH TO CHANGE THINGS
TO PLAIN RAIN BEFORE ENDING.
MONDAY NIGHT WILL BE DRY UNDER NW FLOW ALOFT AND HIGH PRESSURE
PASSING OVER THE REGION.
ANOTHER STORM SYSTEM IMPACTS THE REGION TUESDAY INTO WEDNESDAY.
THERE ARE SOME MODEL DIFFERENCES WITH THIS SYSTEM WITH RESPECT TO
THE TRACK OF THE SURFACE LOW AND THE LOCATION OF ITS ASSOCIATED
FRONTAL BOUNDARIES. WILL CONTINUE...FOR SIMPLICITY PURPOSES...NOT TO
ADDRESS THE SLEET OR FREEZING RAIN POTENTIAL AT THIS TIME.
TEMPERATURES ARE EXPECTED TO REMAIN BELOW NORMAL SATURDAY AND
SUNDAY...WITH A RETURN TO NEAR NORMAL ON MONDAY. TEMPERATURES FALL
BACK BELOW NORMAL ON TUESDAY...WITH TEMPERATURES APPROACHING NORMAL
ONCE AGAIN ON WEDNESDAY.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL PASS WELL TO THE SE OF THE TERMINALS TODAY. HIGH
PRESSURE BUILDS IN TONIGHT.
VFR TO START THE TAF PERIOD. LOWERING CLOUDS WITH PASSING LOW
PRESSURE MAY PRODUCE SOME LIGHT SNOW AND MVFR CIGS MAINLY FROM LATE
MORNING INTO EARLY AFTERNOON. HIGH CONFIDENCE IN VFR THIS EVENING.
N-NE WINDS 5-10 KT THIS MORNING BECOME 8-12 KT DURING THE LATE
MORNING AND AFTERNOON...THEN DIMINISH THIS EVENING.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z.
KLGA FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z.
KEWR FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z.
KHPN FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z.
KISP FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z.
.OUTLOOK FOR 06Z FRI THROUGH MON...
.LATE THU NIGHT-SUNDAY...VFR.
.SUNDAY NIGHT-MON...LIGHT SNOW POSSIBLY MIXED WITH RAIN. MVFR CONDS
POSSIBLE.
&&
.MARINE...
AN AREA OF LOW PRESSURE OFF THE MID ATLANTIC COAST THIS MORNING WILL
PASS TO THE SOUTHEAST OF THE WATERS TODAY. AFTER COLLAB WITH
SURROUNDING OFFICES...WILL ISSUE A SCA FOR THE OCEAN WATERS TODAY.
WINDS...ESPECIALLY ACROSS THE OUTER PORTION OF THE ZONES WELL SOUTH
OF LONG ISLAND...WILL COME CLOSE TO 25 KTS. IN ADDITION...SEAS PER
WAVE WATCH BUILD TO 5 FEET FOR THE OFFSHORE BUOYS. BORDERLINE...BUT
SCA ALREADY IN EFFECT FOR THE WATERS OFF NJ AND NEW ENGLAND...SO
WILL FOLLOW FOR CONTINUITY.
BY TONIGHT...THE LOW PASSES WELL TO THE EAST AS A RIDGE OF HIGH
PRESSURE BUILDS FROM THE WEST. PERSISTENT NORTHERLY WINDS
CONTINUE...BUT LIGHTEN. DO NOT ANTICIPATE WIND SPEEDS CLOSE TO SCA
CRITERIA TONIGHT AND FRIDAY. THE BIGGEST QUESTION IS WHAT HAPPENS TO
OCEAN SEAS. GUIDANCE SUGGESTS SEAS SUBSIDE TONIGHT...BUT BUILD CLOSE
TO 5 FEET YET AGAIN TOWARD FRIDAY MORNING DUE TO E/SE SWELL. NOT TOO
SURE ABOUT THIS...SO NO PLANS AT THIS TIME TO EXTEND THE SCA. IF
ANYTHING...A SCA FOR HAZARDOUS SEAS MAY BE NEEDED LATE TONIGHT
THROUGH FRIDAY.
FOR THE WATERS SURROUNDING LONG ISLAND...WINDS REMAIN BELOW 25
KTS...AND SEAS REMAIN RATHER TRANQUIL. SPEAKING OF SEAS...MANY OF
THE BAYS REMAIN FROZEN...AND THAT IS NOT GOING TO CHANGE ANYTIME
SOON.
SCA LEVEL SEAS COULD LINGER ON THE COASTAL OCEAN WATERS EAST OF
MORICHES INLET FRIDAY NIGHT...OTHERWISE SUB-SMALL CRAFT ADVISORY
CONDITIONS ARE EXPECTED ON ALL WATERS FROM FRIDAY NIGHT INTO SUNDAY.
INCREASING SW WINDS ARE EXPECTED TO BUILD SEAS TO SCA LEVELS ON THE
COASTAL OCEAN WATERS LATE SUNDAY INTO MONDAY. NW FLOW BEHIND A COLD
FRONT COULD PRODUCE GUSTS TO SMALL CRAFT LEVELS ON ALL WATERS ON
MONDAY.
&&
.HYDROLOGY...
A FEW HUNDREDTHS OF LIQUID EQUIVALENT IS POSSIBLE TODAY.
THERE IS THE POTENTIAL FOR LIGHT TO POSSIBLY MODERATE LIQUID
EQUIVALENT TO FALL FROM SUNDAY INTO MONDAY. AT THIS TIME NO
SIGNIFICANT PRECIPITATION IS EXPECTED.
ICE WILL CONTINUE TO DEVELOP ON LOCAL AREA RIVERS AND STREAMS AS
TEMPS REMAIN WELL BELOW AVERAGE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...BC/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...BC
AVIATION...DS
MARINE...BC/PW
HYDROLOGY...BC/PW
AREA FORECAST DISCUSSION
NWS ALBANY NY
100 AM EST THU FEB 26 2015
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE REGION TONIGHT. A
SOUTHERN STREAM STORM SHOULD PASS WELL TO OUR SOUTH ON THURSDAY...
BUT COULD BRING SOME LIGHT SNOW TO AREAS WELL SOUTH OF ALBANY...
WITH A WEAK DISTURBANCE PASSING BY TO THE NORTH... POSSIBLY
BRINGING SOME LIGHT SNOW TO THE REST OF THE REGION...ESPECIALLY
NORTH AND WEST OF ALBANY. ANOTHER HIGH PRESSURE AND MORE COLD
WEATHER WILL FINISH OFF OUR SECOND COLDEST FEBRUARY ON RECORD.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 100 AM EST...A STORM SYSTEM IS LOCATED OVER THE SOUTHEAST
AND IS LIFTING NORTHEAST TOWARDS THE MID ATLANTIC STATES. ALTHOUGH
THE BULK OF THE MOISTURE WITH THIS SYSTEM IS SHIFTING OFFSHORE...A
LARGE SHIELD OF MID AND HIGH LEVEL CLOUDS ARE STREAMING UP FROM
THE SOUTHWEST TOWARDS OUR AREA. WITH LIGHT WINDS AND RELATIVELY
CLEAR SKIES IN PLACE...TEMPS HAVE DROPPED QUICKLY THIS EVENING
INTO THE SINGLE DIGITS AND TEENS. HOWEVER...TEMPS WILL STOP
FALLING AS FAST WITH THE CLOUDS MOVING INTO THE AREA. OVERNIGHT
LOWS WILL GENERALLY BE 0 TO 10...ALTHOUGH THE SRN ADIRONDACKS AND
LAKE GEORGE-GLENS FALLS AREA WILL SEE LOWS ZERO TO 10 BELOW...AS
CLOUDS WILL TAKE THE LONGEST TO REACH THOSE NORTHERN AREAS.
THE 04Z 3KM HRRR SHOWS IT REMAINING PRECIP FREE OVERNIGHT.
HOWEVER...SOME VERY LIGHT SNOW SHOWERS OR FLURRIES MAY TRY TO MOVE
TOWARDS THE MID HUDSON VALLEY TOWARDS SUNRISE...ALTHOUGH WITH VERY
DRY LOW LEVELS IN PLACE...IT/S EXPECTED THAT ANY OF THIS PRECIP
WILL LIKELY DRY UP BEFORE IT REACHES THE SURFACE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
A POTENT SOUTHERN STREAM STORM LOOKS TO BRING A SIGNIFICANT
SNOWFALL TO THE SOUTHEAST AND MID ATLANTIC REGION. THIS STORM
SHOULD STAY WELL TO OUR SOUTH. HOWEVER...A WEAK DISTURBANCE IN THE
NORTHERN STREAM...NOTICEABLE ON THE H20 WATER VAPOR LOOP OVER
THE UPPER MIDWEST MIGHT HAVE JUST ENOUGH MOISTURE ON THE NORTHERN
FRINGE OF THE STORM...TO GENERATE A LITTLE LIGHT SNOW OR FLURRIES
IN OUR PARTS COME THURSDAY. ANY FLURRIES OR LIGHT SNOW LOOK TO
OVERSPREAD THE REGION AFTER DAYBREAK...BUT WILL MAINLY ONLY AFFECT
THE FAR SOUTHEASTERN AREAS OF THE CWA. AT MOST...A DUSTING OF SNOW
WILL OCCUR.
IT WILL COLD WITH MORE CLOUDS THAN SUNSHINE...ESPECIALLY ALBANY
SOUTHWARD. LOOK FOR HIGHS GENERALLY IN THE TEENS TO AROUND 20. A
NORTH WIND WILL AVERAGE 5 TO 15 MPH.
THURSDAY NIGHT...THE WEAK NORTHERN SYSTEM (AND THE MUCH STRONG
SOUTHERN STORM) WILL PULL AWAY AND ALLOW A LARGE HIGH PRESSURE TO
BUILD IN TO OUR SOUTH. THIS WILL PROVIDE ANOTHER SHORT OF VERY COLD
ARCTIC...NOT QUITE AS COLD AS ITS PREDECESSORS...BUT COLD ENOUGH TO
POTENTIALLY GIVE ALBANY TWO BELOW ZERO NIGHTS (THURSDAY AND FRIDAY
NIGHTS). OUTLYING AREAS LOOK TO REACH DOUBLE DIGITS BELOW ZERO EACH
NIGHT.
IF ALBANY WERE TO GO BELOW ZERO BOTH THESE THURSDAY AND FRIDAY
NIGHTS...WE WOULD TIE THE MOST NIGHTS BELOW ZERO IN ANY FEBRUARY
WITH 13 (LAST HAPPENED IN 1914). WE ALSO LOOK TO HAVE A LOCK ON THE
SECOND COLDEST FEBRUARY EVER AND STILL HAVE A SHOT AT OUR COLDEST ON
RECORD...12.1 DEGREES SET BACK IN 1934.
SUNSHINE ON FRIDAY AND ESPECIALLY SATURDAY SHOULD SEND HIGHS
GENERALLY BACK INTO THE TEENS FROM THE CAPITAL REGION
NORTHWARD...AND LOWER AND EVEN SOME MID 20S TO THE SOUTH OF ALBANY.
KEEP IN MIND NORMAL HIGHS FOR THE CAPITAL REGION WILL BE IN THE
UPPER 30S AT THIS POINT SO WE WILL STILL BE WAY BELOW AVERAGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE LONG TERM
PORTION OF THE FORECAST. IN ADDITION...THE STORM TRACK...WHICH HAS
BEEN TEMPORARILY DEFLECTED MAINLY SOUTH OF THE REGION IN THE NEAR-
AND SHORT-TERM...WILL BEGIN TO LIFT BACK NORTH...OFFERING SOME
THREATS FOR AT LEAST LIGHT-MODERATE PRECIP LATE SUN INTO EARLY
MON...THEN AGAIN FOR LATE TUE-WED. HERE ARE SOME MORE SPECIFICS...
SAT NT-MON...HIGH PRESSURE SHOULD BRING GENERALLY CLEAR AND COLD
CONDITIONS FOR SAT NT/SUN AM...WITH MIN TEMPS LIKELY FALLING BELOW
ZERO IN MOST AREAS. THEN...A PV ANOMALY IN THE NORTHERN STREAM IS
EXPECTED TO PASS NORTH OF THE GREAT LAKES LATER SUN INTO SUN NT.
SOME SOUTHERN STREAM MOISTURE...ASSOCIATED WITH A BROAD MID/UPPER
LEVEL SOUTHWEST FLOW MAY BECOME ENTRAINED INTO THE APPROACHING UPPER
LEVEL DYNAMICS WITH THIS SYSTEM...ALLOWING FOR LIGHT TO POSSIBLY
MODERATE SNOW TO DEVELOP SUN AFTERNOON/EVENING...AND CONTINUING INTO
MUCH OF SUN NT BEFORE TAPERING OFF FROM NW TO SE MON AM. QPF IS
HIGHEST ON THE ECMWF...WHERE AROUND 0.35-0.50 LIQUID EQUIVALENT IS
INDICATED...GREATEST FOR AREAS NEAR AND ESP NORTH OF INTERSTATE 90.
FORECAST THERMAL PROFILES APPEAR FAVORABLE FOR ALL SNOW...SO THERE
COULD BE SOME MODERATE AMTS...PARTICULARLY AGAIN IN THE MOHAWK
VALLEY/LAKE GEORGE/SARATOGA REGIONS INTO SOUTHERN VT. AT THIS
TIME...WILL INDICATE HIGH CHC POPS FOR LATE SUN...THEN LIKELY FOR
SUN NT FROM I-90 NORTHWARD...AND HIGH CHC TO THE SOUTH. TEMPS
SHOULD BE MAINLY IN THE 20S TO LOWER 30S FOR SUN MAXES...AND TEENS
TO LOWER/MID 20S IN VALLEY AREAS FOR SUN NT/MON AM...WARMEST
ACROSS THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD CO CT. ON
MON...AFTER ANY STEADIER PRECIP TAPERS OFF...CLOUDS AND SOME
SPOTTY FLURRIES OR EVEN DRIZZLE MAY LINGER...AS MAX TEMPS REACH
THE LOWER/MID 30S IN VALLEYS...AND 25-30 ACROSS HIGHER ELEVATIONS.
MON NT-WED...HIGH PRESSURE BRIEFLY BUILDS INTO THE REGION FOR MON NT-
EARLY TUE...BEFORE ANOTHER PV ANOMALY...THIS ONE ORIGINATING IN THE
SOUTHERN STREAM...APPROACHES FROM THE SOUTHWEST LATER TUE INTO WED.
THERE IS MUCH UNCERTAINTY REGARDING THIS FEATURE...AND WHETHER IT
SHEARS OUT IN THE STRONGLY MID/UPPER LEVEL SOUTHWEST CONFLUENT FLOW
EXTENDING FROM THE SOUTHERN ROCKIES INTO THE NORTHEAST STATES...AND
ALSO WHERE THE LOW/MID LEVEL THERMAL GRADIENT SETS UP. BOTH THE
12Z/25 GFS AND ECMWF SUGGEST THAT THE PV ANOMALY WEAKENS AS IT
TRACKS TOWARD THE GREAT LAKES REGION. HOWEVER...A SURGE OF
ISENTROPIC LIFT DEVELOPS AHEAD OF THE FEATURE...WITH VARYING DEGREES
ON NORTHWARD EXTENT AND RESULTING PRECIP. THE DETERMINISTIC GFS
SUGGEST POSSIBLY A QUICK SURGE OF SNOW OR A WINTRY MIX DEVELOPING
LATE TUE OR TUE NT...GRADUALLY TAPERING OFF WED AM...POSSIBLY AS A
LIGHT MIX OR EVEN RAIN/DRIZZLE...WHILE THE ECMWF SUGGESTS MOST OF
THE PRECIP TRACKS SOUTH OF THE REGION...WHICH IS MUCH FARTHER SOUTH
THAN ITS PREVIOUS CYCLES. MEANWHILE...THE 12Z/25 GEFS VARY
SIGNIFICANTLY IN HANDLING THE TRACK OF ANY ASSOCIATED SFC
SYSTEM...WITH SOME SUGGESTING A N/W TRACK ALLOWING FOR WARMING AND
MORE RAIN ACROSS THE REGION...AND OTHERS FURTHER S AND E WITH SNOW
OR A WINTRY MIX. AT THIS TIME...DUE TO SIGNIFICANT
UNCERTAINTY...WILL FAVOR A COLDER SOLUTION...BUT ALSO FURTHER N WITH
THE PRECIP...WITH CHANCES FOR SNOW FOR LATE TUE INTO EARLY WED. MON
NT/TUE AM SHOULD BE QUITE COLD WITH MINS MAINLY IN THE SINGLE DIGITS
TO LOWER TEENS...AND TUE MAXES IN THE 20S...WITH PERHAPS SOME LOWER
30S IN VALLEY AREAS SOUTH OF ALBANY. TUE NT/WED AM MINS SHOULD ONLY
FALL INTO THE 20S FOR MOST AREAS...WITH WED MAX TEMPS POSSIBLY
RISING INTO THE 30S FOR VALLEYS...AND 25-30 ACROSS HIGHER ELEVATIONS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
RIDGING OVER THE REGION WILL WEAKEN SOME TODAY AS A POTENT SOUTHERN
STREAM LOW PRESSURE SYSTEM MOVES OFF THE SOUTHEAST COAST AND TRACKS
EAST-NORTHEAST OUT TO SEA. RIDGING WILL BUILD BACK IN AS THE STORM
MOVES FARTHER AWAY FROM THE COAST.
CLOUDS ASSOCIATED WITH THE SYSTEM WILL OVERSPREAD THE REGION AND
THICKEN AND LOWER TODAY. THE NORTHERN EDGE OF THE PRECIPITATION
SHIELD ASSOCIATED WITH THE STORM IS EXPECTED TO POSSIBLY REACHED
KPOU WITH LIGHT SNOW THIS MORNING INTO THE EARLY AFTERNOON.
OTHERWISE MVFR CONDITIONS ARE POSSIBLE AT THE OTHER TAF SITES
LATER IN THE AFTERNOON INTO THE EVENING WITH SOME FLURRIES
POSSIBLE.
LIGHT MAINLY NORTHWEST TO NORTHEAST WINDS ARE EXPECTED THROUGH THE
TAF PERIOD...06Z/FRIDAY.
OUTLOOK...
FRI-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUN: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE AFTERNOON.
SUN NIGHT: HIGH OPERATIONAL IMPACT. SN LIKELY.
MON: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE MORNING.
&&
.HYDROLOGY...
A FEW SNOW SHOWERS OR FLURRIES ARE POSSIBLE FOR FAR SOUTHEASTERN
AREAS ON THURSDAY...BUT TOTAL LIQUID EQUIVALENT WILL GENERALLY
ONLY BE A FEW HUNDREDTHS OF AN INCH AT MOST. OTHERWISE...IT WILL
REMAIN DRY THROUGH SUNDAY MORNING. SOME LIGHT SNOWFALL IS
POSSIBLE FOR THE REGION LATE SUNDAY THROUGH MONDAY MORNING.
TEMPERATURES WILL REMAIN BELOW FREEZING THROUGH SUNDAY NIGHT.
TEMPERATURES MAY BRIEFLY RISE ABOVE FREEZING DURING THE DAY ON
MONDAY. WITH THE CONTINUED COLD CONDITIONS IN PLACE...ICE WILL
CONTINUE TO STRENGTHEN AND THICKEN ON AREA RIVERS...STREAMS...LAKES...AND
PONDS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...HWJIV/FRUGIS
LONG TERM...KL
AVIATION...IAA
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1259 AM EST THU FEB 26 2015
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE REGION TONIGHT. A
SOUTHERN STREAM STORM SHOULD PASS WELL TO OUR SOUTH ON THURSDAY...
BUT COULD BRING SOME LIGHT SNOW TO AREAS WELL SOUTH OF ALBANY...
WITH A WEAK DISTURBANCE PASSING BY TO THE NORTH... POSSIBLY
BRINGING SOME LIGHT SNOW TO THE REST OF THE REGION...ESPECIALLY
NORTH AND WEST OF ALBANY. ANOTHER HIGH PRESSURE AND MORE COLD
WEATHER WILL FINISH OFF OUR SECOND COLDEST FEBRUARY ON RECORD.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1259 AM EST...A STORM SYSTEM IS LOCATED OVER THE SOUTHEAST
AND IS LIFTING NORTHEAST TOWARDS THE MID ATLANTIC STATES.
ALTHOUGH THE BULK OF THE MOISTURE WITH THIS SYSTEM IS SHIFTING
OFFSHORE...A LARGE SHIELD OF MID AND HIGH LEVEL CLOUDS ARE
STREAMING UP FROM THE SOUTHWEST TOWARDS OUR AREA. WITH LIGHT WINDS
AND RELATIVELY CLEAR SKIES IN PLACE...TEMPS HAVE DROPPED QUICKLY
THIS EVENING INTO THE SINGLE DIGITS AND TEENS. HOWEVER...TEMPS
WILL STOP FALLING AS FAST WITH THE CLOUDS MOVING INTO THE AREA.
OVERNIGHT LOWS WILL GENERALLY BE 0 TO 10...ALTHOUGH THE SRN
ADIRONDACKS AND LAKE GEORGE-GLENS FALLS AREA WILL SEE LOWS ZERO TO
10 BELOW...AS CLOUDS WILL TAKE THE LONGEST TO REACH THOSE NORTHERN
AREAS.
THE 04Z 3KM HRRR SHOWS IT REMAINING PRECIP FREE OVERNIGHT.
HOWEVER...SOME VERY LIGHT SNOW SHOWERS OR FLURRIES MAY TRY TO MOVE
TOWARDS THE MID HUDSON VALLEY TOWARDS SUNRISE...ALTHOUGH WITH VERY
DRY LOW LEVELS IN PLACE...IT/S EXPECTED THAT ANY OF THIS PRECIP
WILL LIKELY DRY UP BEFORE TI REACHES THE SURFACE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
A POTENT SOUTHERN STREAM STORM LOOKS TO BRING A SIGNIFICANT
SNOWFALL TO THE SOUTHEAST AND MID ATLANTIC REGION. THIS STORM
SHOULD STAY WELL TO OUR SOUTH. HOWEVER...A WEAK DISTURBANCE IN THE
NORTHERN STREAM...NOTICEABLE ON THE H20 WATER VAPOR LOOP OVER
THE UPPER MIDWEST MIGHT HAVE JUST ENOUGH MOISTURE ON THE NORTHERN
FRINGE OF THE STORM...TO GENERATE A LITTLE LIGHT SNOW OR FLURRIES
IN OUR PARTS COME THURSDAY. ANY FLURRIES OR LIGHT SNOW LOOK TO
OVERSPREAD THE REGION AFTER DAYBREAK...BUT WILL MAINLY ONLY AFFECT
THE FAR SOUTHEASTERN AREAS OF THE CWA. AT MOST...A DUSTING OF SNOW
WILL OCCUR.
IT WILL COLD WITH MORE CLOUDS THAN SUNSHINE...ESPECIALLY ALBANY
SOUTHWARD. LOOK FOR HIGHS GENERALLY IN THE TEENS TO AROUND 20. A
NORTH WIND WILL AVERAGE 5 TO 15 MPH.
THURSDAY NIGHT...THE WEAK NORTHERN SYSTEM (AND THE MUCH STRONG
SOUTHERN STORM) WILL PULL AWAY AND ALLOW A LARGE HIGH PRESSURE TO
BUILD IN TO OUR SOUTH. THIS WILL PROVIDE ANOTHER SHORT OF VERY COLD
ARCTIC...NOT QUITE AS COLD AS ITS PREDECESSORS...BUT COLD ENOUGH TO
POTENTIALLY GIVE ALBANY TWO BELOW ZERO NIGHTS (THURSDAY AND FRIDAY
NIGHTS). OUTLYING AREAS LOOK TO REACH DOUBLE DIGITS BELOW ZERO EACH
NIGHT.
IF ALBANY WERE TO GO BELOW ZERO BOTH THESE THURSDAY AND FRIDAY
NIGHTS...WE WOULD TIE THE MOST NIGHTS BELOW ZERO IN ANY FEBRUARY
WITH 13 (LAST HAPPENED IN 1914). WE ALSO LOOK TO HAVE A LOCK ON THE
SECOND COLDEST FEBRUARY EVER AND STILL HAVE A SHOT AT OUR COLDEST ON
RECORD...12.1 DEGREES SET BACK IN 1934.
SUNSHINE ON FRIDAY AND ESPECIALLY SATURDAY SHOULD SEND HIGHS
GENERALLY BACK INTO THE TEENS FROM THE CAPITAL REGION
NORTHWARD...AND LOWER AND EVEN SOME MID 20S TO THE SOUTH OF ALBANY.
KEEP IN MIND NORMAL HIGHS FOR THE CAPITAL REGION WILL BE IN THE
UPPER 30S AT THIS POINT SO WE WILL STILL BE WAY BELOW AVERAGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE LONG TERM
PORTION OF THE FORECAST. IN ADDITION...THE STORM TRACK...WHICH HAS
BEEN TEMPORARILY DEFLECTED MAINLY SOUTH OF THE REGION IN THE NEAR-
AND SHORT-TERM...WILL BEGIN TO LIFT BACK NORTH...OFFERING SOME
THREATS FOR AT LEAST LIGHT-MODERATE PRECIP LATE SUN INTO EARLY
MON...THEN AGAIN FOR LATE TUE-WED. HERE ARE SOME MORE SPECIFICS...
SAT NT-MON...HIGH PRESSURE SHOULD BRING GENERALLY CLEAR AND COLD
CONDITIONS FOR SAT NT/SUN AM...WITH MIN TEMPS LIKELY FALLING BELOW
ZERO IN MOST AREAS. THEN...A PV ANOMALY IN THE NORTHERN STREAM IS
EXPECTED TO PASS NORTH OF THE GREAT LAKES LATER SUN INTO SUN NT.
SOME SOUTHERN STREAM MOISTURE...ASSOCIATED WITH A BROAD MID/UPPER
LEVEL SOUTHWEST FLOW MAY BECOME ENTRAINED INTO THE APPROACHING UPPER
LEVEL DYNAMICS WITH THIS SYSTEM...ALLOWING FOR LIGHT TO POSSIBLY
MODERATE SNOW TO DEVELOP SUN AFTERNOON/EVENING...AND CONTINUING INTO
MUCH OF SUN NT BEFORE TAPERING OFF FROM NW TO SE MON AM. QPF IS
HIGHEST ON THE ECMWF...WHERE AROUND 0.35-0.50 LIQUID EQUIVALENT IS
INDICATED...GREATEST FOR AREAS NEAR AND ESP NORTH OF INTERSTATE 90.
FORECAST THERMAL PROFILES APPEAR FAVORABLE FOR ALL SNOW...SO THERE
COULD BE SOME MODERATE AMTS...PARTICULARLY AGAIN IN THE MOHAWK
VALLEY/LAKE GEORGE/SARATOGA REGIONS INTO SOUTHERN VT. AT THIS
TIME...WILL INDICATE HIGH CHC POPS FOR LATE SUN...THEN LIKELY FOR
SUN NT FROM I-90 NORTHWARD...AND HIGH CHC TO THE SOUTH. TEMPS
SHOULD BE MAINLY IN THE 20S TO LOWER 30S FOR SUN MAXES...AND TEENS
TO LOWER/MID 20S IN VALLEY AREAS FOR SUN NT/MON AM...WARMEST
ACROSS THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD CO CT. ON
MON...AFTER ANY STEADIER PRECIP TAPERS OFF...CLOUDS AND SOME
SPOTTY FLURRIES OR EVEN DRIZZLE MAY LINGER...AS MAX TEMPS REACH
THE LOWER/MID 30S IN VALLEYS...AND 25-30 ACROSS HIGHER ELEVATIONS.
MON NT-WED...HIGH PRESSURE BRIEFLY BUILDS INTO THE REGION FOR MON NT-
EARLY TUE...BEFORE ANOTHER PV ANOMALY...THIS ONE ORIGINATING IN THE
SOUTHERN STREAM...APPROACHES FROM THE SOUTHWEST LATER TUE INTO WED.
THERE IS MUCH UNCERTAINTY REGARDING THIS FEATURE...AND WHETHER IT
SHEARS OUT IN THE STRONGLY MID/UPPER LEVEL SOUTHWEST CONFLUENT FLOW
EXTENDING FROM THE SOUTHERN ROCKIES INTO THE NORTHEAST STATES...AND
ALSO WHERE THE LOW/MID LEVEL THERMAL GRADIENT SETS UP. BOTH THE
12Z/25 GFS AND ECMWF SUGGEST THAT THE PV ANOMALY WEAKENS AS IT
TRACKS TOWARD THE GREAT LAKES REGION. HOWEVER...A SURGE OF
ISENTROPIC LIFT DEVELOPS AHEAD OF THE FEATURE...WITH VARYING DEGREES
ON NORTHWARD EXTENT AND RESULTING PRECIP. THE DETERMINISTIC GFS
SUGGEST POSSIBLY A QUICK SURGE OF SNOW OR A WINTRY MIX DEVELOPING
LATE TUE OR TUE NT...GRADUALLY TAPERING OFF WED AM...POSSIBLY AS A
LIGHT MIX OR EVEN RAIN/DRIZZLE...WHILE THE ECMWF SUGGESTS MOST OF
THE PRECIP TRACKS SOUTH OF THE REGION...WHICH IS MUCH FARTHER SOUTH
THAN ITS PREVIOUS CYCLES. MEANWHILE...THE 12Z/25 GEFS VARY
SIGNIFICANTLY IN HANDLING THE TRACK OF ANY ASSOCIATED SFC
SYSTEM...WITH SOME SUGGESTING A N/W TRACK ALLOWING FOR WARMING AND
MORE RAIN ACROSS THE REGION...AND OTHERS FURTHER S AND E WITH SNOW
OR A WINTRY MIX. AT THIS TIME...DUE TO SIGNIFICANT
UNCERTAINTY...WILL FAVOR A COLDER SOLUTION...BUT ALSO FURTHER N WITH
THE PRECIP...WITH CHANCES FOR SNOW FOR LATE TUE INTO EARLY WED. MON
NT/TUE AM SHOULD BE QUITE COLD WITH MINS MAINLY IN THE SINGLE DIGITS
TO LOWER TEENS...AND TUE MAXES IN THE 20S...WITH PERHAPS SOME LOWER
30S IN VALLEY AREAS SOUTH OF ALBANY. TUE NT/WED AM MINS SHOULD ONLY
FALL INTO THE 20S FOR MOST AREAS...WITH WED MAX TEMPS POSSIBLY
RISING INTO THE 30S FOR VALLEYS...AND 25-30 ACROSS HIGHER ELEVATIONS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
RIDGING OVER THE REGION WILL WEAKEN SOME TODAY AS A POTENT SOUTHERN
STREAM LOW PRESSURE SYSTEM MOVES OFF THE SOUTHEAST COAST AND TRACKS
EAST-NORTHEAST OUT TO SEA. RIDGING WILL BUILD BACK IN AS THE STORM
MOVES FARTHER AWAY FROM THE COAST.
CLOUDS ASSOCIATED WITH THE SYSTEM WILL OVERSPREAD THE REGION AND
THICKEN AND LOWER TODAY. THE NORTHERN EDGE OF THE PRECIPITATION
SHIELD ASSOCIATED WITH THE STORM IS EXPECTED TO POSSIBLY REACHED
KPOU WITH LIGHT SNOW THIS MORNING INTO THE EARLY AFTERNOON.
OTHERWISE MVFR CONDITIONS ARE POSSIBLE AT THE OTHER TAF SITES
LATER IN THE AFTERNOON INTO THE EVENING WITH SOME FLURRIES
POSSIBLE.
LIGHT MAINLY NORTHWEST TO NORTHEAST WINDS ARE EXPECTED THROUGH THE
TAF PERIOD...06Z/FRIDAY.
OUTLOOK...
FRI-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUN: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE AFTERNOON.
SUN NIGHT: HIGH OPERATIONAL IMPACT. SN LIKELY.
MON: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE MORNING.
&&
.HYDROLOGY...
A FEW SNOW SHOWERS OR FLURRIES ARE POSSIBLE FOR FAR SOUTHEASTERN
AREAS ON THURSDAY...BUT TOTAL LIQUID EQUIVALENT WILL GENERALLY
ONLY BE A FEW HUNDREDTHS OF AN INCH AT MOST. OTHERWISE...IT WILL
REMAIN DRY THROUGH SUNDAY MORNING. SOME LIGHT SNOWFALL IS
POSSIBLE FOR THE REGION LATE SUNDAY THROUGH MONDAY MORNING.
TEMPERATURES WILL REMAIN BELOW FREEZING THROUGH SUNDAY NIGHT.
TEMPERATURES MAY BRIEFLY RISE ABOVE FREEZING DURING THE DAY ON
MONDAY. WITH THE CONTINUED COLD CONDITIONS IN PLACE...ICE WILL
CONTINUE TO STRENGTHEN AND THICKEN ON AREA RIVERS...STREAMS...LAKES...AND
PONDS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...HWJIV/FRUGIS
LONG TERM...KL
AVIATION...IAA
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
947 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE SYSTEM WILL QUICKLY MOVE OFF THE NORTH CAROLINA COAST
TODAY WHILE ANOTHER ARCTIC HIGH PRESSURE SYSTEM NOSES IN BY FRIDAY.
THE HIGH WILL MOVE OFF THE COAST BY EARLY NEXT WEEK FOLLOWED BY
ANOTHER COLD FRONT PASSAGE ON MONDAY. A LOW PRESSURE EJECTS OUT OF
THE CENTRAL PLAINS AND CROSSES OUR REGION ON TUESDAY INTO WEDNESDAY.
THE LOWS ASSOCIATED COLD FRONT PUSHES THROUGH LATER ON WEDNESDAY
WITH ANOTHER EXPANSIVE HIGH PRESSURE SYSTEM FILLING IN BEHIND IT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST COASTAL LOW CONTINUES TO LIFT NORTHEAST OFF THE
CAROLINA COAST. SEVERAL INCHES OF SNOW HAVE FALLEN ACROSS THE
EASTERN SHORE OF MARYLAND, CENTRAL AND SOUTHERN DELAWARE AND
SOUTHEAST NEW JERSEY. THE HIGHEST TOTAL CLOSE TO 5 INCHES WAS
RECORDED ON FENWICK ISLAND SO FAR. SNOW TOTALS WERE UPDATED WITH
THESE CURRENT REPORTS AND WITH THE PROSPECTS FOR AN ADDITIONAL HOUR
OR TWO OF STEADY SNOW POSSIBLY MODERATE TO HEAVY FOR BRIEF
INTERVALS. THIS DID RAISE TOTALS ALONG THE DELAWARE BEACHES NORTH
THROUGH ATLANTIC CITY SLIGHTLY. FURTHER NORTHWEST, DRY AIR HAS
ERODED THE NORTHERN EDGE OF THE PRECIPITATION SHIELD SUFFICIENTLY
THIS MORNING. TOTALS WERE UNDER AN INCH THROUGH WILMINGTON AND
PHILADELPHIA THIS MORNING. THE NORTHERN EXTENT OF THE WINTER
WEATHER ADVISORY HAS BEEN CANCELLED WITH ONLY SOME LINGERING
FLURRIES POSSIBLE. THE RAP AND HRRR SHOW SNOW EXITING THE BEACHES
AROUND 17Z AND THE WINTER STORM ADVISORIES/WARNINGS GO THROUGH
18Z WHERE ACCUMULATING SNOW HAS FALLEN.
DRY AIR WILL CONTINUE TO PENETRATE FURTHER SOUTH THROUGHOUT THE
DAY AND HAVE POPS TAPERING DOWN TO SLIGHT CHANCE FOR THE AFTERNOON
HOURS. ADDITIONAL SNOW SHOULD JUST BE IN THE FORM OF FLURRIES OR
VERY LIGHT SNOW THIS AFTERNOON. TEMPERATURES WERE ADJUSTED
DOWNWARD SOME WITH THE PRECIPITATION IN THE AREA. &&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
TONIGHT, A WEAK MID LEVEL SHORT WAVE TROUGH LOOKS TO SIDESWIPE THE
NORTHWESTERN PORTIONS OF OUR REGION. AS A RESULT...LIGHT SNOW IS
POSSIBLE GENERALLY NORTH AND WEST OF THE PHILLY SUBURBS. MOISTURE
AVAILABILITY IS GOING TO BE PROBLEMATIC FOR THIS SYSTEM AS THERE IS
LITTLE CHANCE FOR ANY MOISTURE ADVECTION BEHIND TODAYS SYSTEM.
THEREFORE, ANY SNOW AMOUNTS SHOULD BE BELOW AN INCH.
AS FOR TEMPERATURES...STAYED CLOSE TO GUIDANCE AS MID LEVEL CLOUDS
SHOULD HELP TO LIMIT RADIATIONAL COOLING EVEN FOR LOCATIONS THAT
STILL HAVE SNOW PACK.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
LAST PIECE OF MID-LEVEL ENERGY MOVES THROUGH THE REGION ON FRIDAY AS
THE BROAD SCALE TROUGHING FINALLY RELINQUISHING ITS GRASP ON OUR
REGION. THE MID-LEVELS TAKE ON MORE OF A ZONAL-ISH FLOW OVER THE
WEEKEND WITH THE NEXT EMBEDDED WAVE EXPECTED BY MONDAY FOLLOWED BY
RIDGING THROUGH THE REMAINDER OF THE PERIOD.
FRIDAY - SATURDAY...HIGH PRESSURE WILL BE SQUEEZING IN LATER ON
FRIDAY FROM THE WEST-NORTHWEST. JUST AHEAD OF THE RIDGING WILL BE A
LAST DITCH EFFORT BY THE BROAD TROUGH TO PUSH A DAMPENING SHORTWAVE
THROUGH THE REGION. WITH LIMITED AMOUNTS OF MOISTURE EXPECTED WE
CONFINED THE SLIGHT CHANCE POPS TO OUR WESTERN ZONES BEFORE DRYING
OUT LATER FRIDAY AFTERNOON. AT THIS POINT THE RIDGING WILL BE ABLE
TO EXERT ITSELF UPON THE AREA AND WE REMAIN DRY, BUT COLD, THROUGH
SATURDAY.
SUNDAY - MONDAY...ZONAL-ISH FLOW TURNS A BIT SHARPER AS THE BROAD
TROUGH RELOADS WELL TO OUR WEST. ANOTHER PASSING SHORTWAVE ALOFT
APPROACHES AND PUSHES A COLD FRONT THROUGH THE REGION LATE SUNDAY
INTO MONDAY MORNING. OUT AHEAD OF THE FRONT TEMPERATURES ARE ABLE TO
MODIFY A BIT THANKS TO THE DEPARTING HIGH PRESSURE NOW OFF THE COAST
AND A LIGHT RETURN FLOW SETTING UP. WE CONFINED THE HIGHER POPS
UNTIL LATE SUNDAY NIGHT JUST AHEAD AND WITH THE FRONTAL PASSAGE.
DECENT AMOUNT OF THETA-E ADVECTION OCCURRING AHEAD OF THE FRONT WITH
ENOUGH LIFT FOR A LIGHT SNOW TO START BEFORE A WINTRY MIX/
CHANGEOVER, MOSTLY ACROSS THE SOUTHERN HALF OF THE CWA, BY MONDAY
MORNING. THE FRONT THEN MOVES THROUGH AND ALLOWS FOR ANOTHER SHOT OF
COOLER AIR AND MORE PRECIPITATION PHASE CHANGES.
TUESDAY - WEDNEDSAY...WITH THE COLD FRONT TO OUR EAST AND A BRIEF
SHOT OF HIGH PRESSURE BEHIND IT, THE NEXT SYSTEM, FORMING DEEP IN
THE SOUTH, BEGINS TO ENTER THE REGION FROM THE SOUTHWEST LATER ON
TUESDAY. A LIGHT ONSHORE FLOW WILL HELP TO ENHANCE THE LOW-LEVEL
MOISTURE FLUX WHEN COMBINED WITH A STRONG LOW-LEVEL SOUTHERLY SURGE
OF WARM/MOIST AIR. THIS EVENT COULD HAVE A COPIOUS AMOUNT OF
MOISTURE WITH IT, GIVEN ITS ORIGIN AND THE MODIFYING AIRMASS WE`LL
HAVE IN PLACE. TOO EARLY FOR PTYPE SPECIFICS BUT IT DOES APPEAR TO
BE A MIXED EVENT. IT SHOULD BE NOTED THAT SEVERAL TIMES THIS WINTER
THE NUMERICAL GUIDANCE HAS BEEN TOO STRONG WITH THE LOW PRESSURE AS
IT CROSSES THE MID-WEST AND THEREFORE OVER AMPLIFIES/WARMS THE LOW-
LEVELS. A SHIFT TO THE EAST AND A WEAKER SOLUTION WOULD LEAD TO LESS
MIXING.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
SNOW IS TRYING TO BUILD FURTHER NORTH THROUGH THE REGION. HOWEVER, IT
IS ENCOUNTERING A WALL OF DRY AIR. WESTERN TAF SITES, KABE AND
KRDG, WILL LIKELY NOT SEE ANY SNOW AT ALL. FOR THE DELAWARE VALLEY
SITES, KPHL, KPNE, AND KTTN, A 2 TO 3 HOUR PERIOD OF MOSTLY LIGHT
SNOW IS POSSIBLE BETWEEN 12 AND 16Z (SOONER AT KILG, WHILE KTTN
WILL BE THE LAST TO BE AFFECTED). THOUGH IT APPEARS THE MAIN
WINDOW FOR THIS WILL BE ENDING SOON BY 14Z-15Z. AT KILG, KMIV AND
KACY, MOSTLY LIGHT BUT SOME PERIODS OF MODERATE TO HEAVY SNOW SNOW
WILL BE POSSIBLE FOR A MAJORITY OF THE MORNING. BY 18Z HOWEVER,
SNOW SHOULD BE OUT OF THE REGION. TAFS REFLECT MORE OPTIMISTIC
CONDITIONS THAN WHAT IS DEPICTED IN THE GFS LAMP AS IT APPEARS TO
BE UNDERESTIMATING THE DRY AIR IN THE BOUNDARY LAYER. THUS...THINK
THAT ONCE THE SNOW MOVES OUT CONDITIONS SHOULD RETURN TO
VFR...THOUGH THERE REMAINS A SMALL CHANCE THAT MVFR CEILINGS WILL
LINGER THROUGH THE DAY.
OVERNIGHT, CEILINGS SHOULD INCREASE BACK TO VFR, ALBEIT THE LOWER
END OF VFR. THERE IS SOME RISK OF BR DEVELOPING ACROSS THE REGION,
AND A LOW CHANCE OF ANOTHER ROUND OF -SN FOR KRDG AND KABE AFTER
06Z. HOWEVER, IN BOTH CASES THE CHANCE IS TOO LOW TO MENTION IN THE
TAFS AT THIS TIME.
OUTLOOK...
FRIDAY - SATURDAY...MOSTLY VFR. SLIGHT CHANCE FOR EARLY
AFTERNOON MVFR SNOW SHOWERS. NORTHERLY WINDS PREVAIL AS HIGH
PRESSURE NOSES IN FROM THE WEST.
SUNDAY - MONDAY...VFR TO START. CONDITIONS DETERIORATE LATE IN THE
DAY AS THE NEXT SYSTEM APPROACHES FROM THE WEST-SOUTHWEST. SOUTHERLY
WINDS EXPECTED.
&&
.MARINE...
WINDS SHOULD INCREASE SOON RESULTING IN SCA CONDITIONS FOR THE LOWER
BAY AND THE ATLANTIC COASTAL WATERS FOR MUCH OF THE DAY. WITH THE
INCREASE IN WINDS, SEAS WILL SLOWLY BUILD AS WELL (PRIMARILY ON THE
OCEAN). FOR THE OCEAN WATERS A FEW GUSTS ABOVE 30 KT ARE POSSIBLE
PRIMARILY LATE THIS MORNING INTO EARLY THIS AFTERNOON. BY EARLY THIS
EVENING, WINDS SHOULD DIMINISH BELOW 25KT, BUT SEAS ON THE OCEAN
WILL BE SLOW TO DIMINISH. THUS, HAVE EXTENDED THE SCA FOR THE OCEAN
ZONES THROUGH 06Z FOR THE NORTHERN WATERS AND 11Z FOR THE SOUTHERN
WATERS.
OUTLOOK...
FRIDAY - SATURDAY...SUB-SCA EXPECTED, THOUGH PERSISTENT
NORTHEAST WINDS MAY ALLOW FOR BUILDING SEAS ACROSS OUR SOUTHERN
ZONES.
SUNDAY - MONDAY...POSSIBLE SCA CONDITIONS LATE ON SUNDAY AHEAD OF AN
APPROACHING COLD FRONT. INCREASING SOUTHERLY WINDS AND BUILDING SEAS
EXPECTED.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ021>025.
DE...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ002.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ003-
004.
MD...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MDZ012-015-019-020.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ450-451.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ431.
&&
$$
SYNOPSIS...HEAVENER
NEAR TERM...GAINES/JOHNSON
SHORT TERM...JOHNSON
LONG TERM...HEAVENER
AVIATION...GAINES/HEAVENER/JOHNSON
MARINE...HEAVENER/JOHNSON
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
747 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE SYSTEM WILL QUICKLY MOVE OFF THE NORTH CAROLINA COAST
TODAY WHILE ANOTHER ARCTIC HIGH PRESSURE SYSTEM NOSES IN BY FRIDAY.
THE HIGH WILL MOVE OFF THE COAST BY EARLY NEXT WEEK FOLLOWED BY
ANOTHER COLD FRONT PASSAGE ON MONDAY. A LOW PRESSURE EJECTS OUT OF
THE CENTRAL PLAINS AND CROSSES OUR REGION ON TUESDAY INTO WEDNESDAY.
THE LOWS ASSOCIATED COLD FRONT PUSHES THROUGH LATER ON WEDNESDAY
WITH ANOTHER EXPANSIVE HIGH PRESSURE SYSTEM FILLING IN BEHIND IT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
630 AM UPDATE...NO MAJOR CHANGES FROM THE PREVIOUS FORECAST.
HEAVIER SNOW BANDS MOVING THROUGH SOUTHERN DELMARVA AND FAR
SOUTHERN NJ NOW. EXPECT THE BULK OF THE SNOW TO OCCUR BETWEEN NOW
AND LATE THIS MORNING.
PREVIOUS NEAR TERM DISCUSSION...THE LATEST COASTAL LOW CONTINUES
TO LIFT NORTHEAST OFF THE CAROLINA COAST. SNOW HAS BEEN REPORTED
IN SOUTHERN DELMARVA, BUT AS OF 330 AM REMAINS JUST SOUTH OF OUR
CWA.
TIMING STILL LOOKS ON TRACK WITH A MAJORITY OF THE SNOW OCCURRING
FROM NOW THROUGH THE MORNING RUSH HOUR, THEN THE SNOW TAPERING OFF
MID DAY THROUGH THE AFTERNOON HOURS.
AS FOR AMOUNTS, TRENDED THE AMOUNTS DOWN SLIGHTLY FOR THE FOLLOWING
REASONS. FIRST, THERE HAS BEEN PERSISTENT CONVECTION OFF THE NC
COAST WHICH COULD LIMIT THE MOISTURE AND ENERGY THIS FAR NORTH.
SECOND, LATEST WV AND IR SATELLITE IMAGERY SHOW A MID AND UPPER LEVEL
DRY SLOT QUICKLY SLIDING IN FROM THE SW. AS OF 3 AM THE DRY SLOT
EXTENDED FROM SW VA UP TO THE POCONOS. THIS COULD HAVE A SIGNIFICANT
IMPACT FOR THE WESTERN EXTENT OF THE PRECIP. ALSO RELATED TO
SATELLITE, EVEN EAST OF THE DRY SLOT OVER SOUTHERN DELMARVA AND THE
ATLANTIC COASTAL WATERS THERE HAS BEEN A CLOUD TOP WARMING TREND FOR
THE LAST FEW HOURS. FINALLY, MOST OF THE HEAVIER BANDS OF SNOW WE`VE
SEEN UP STREAM SEEM TO BE ASSOCIATED WITH A BAND OF FRONTOGENESIS
WHICH HAS BEEN WELL DEPICTED BY THE RAP. THE RAP SHOWS THIS
FRONTOGENESIS BAND SLIDING EAST BEFORE IT GETS AS FAR AS OUR REGION.
FOR NOW THOUGH, WILL KEEP THE WINTER WEATHER ADVISORY AND WINTER
STORM WARNING AS SOME MODEL SOUNDINGS CONTINUE TO SHOW MODEST OMEGA
VALUES WITHIN THE DENDRITIC GROWTH ZONE, PRIMARILY IN THE FEW HOURS
AROUND THE MORNING RUSH HOUR. THUS THE TIMING OF THE SNOW MAY BE
MORE IMPACTFUL THAN THE ACTUAL AMOUNTS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
TONIGHT, A WEAK MID LEVEL SHORT WAVE TROUGH LOOKS TO SIDESWIPE THE
NORTHWESTERN PORTIONS OF OUR REGION. AS A RESULT...LIGHT SNOW IS
POSSIBLE GENERALLY NORTH AND WEST OF THE PHILLY SUBURBS. MOISTURE
AVAILABILITY IS GOING TO BE PROBLEMATIC FOR THIS SYSTEM AS THERE IS
LITTLE CHANCE FOR ANY MOISTURE ADVECTION BEHIND TODAYS SYSTEM.
THEREFORE, ANY SNOW AMOUNTS SHOULD BE BELOW AN INCH.
AS FOR TEMPERATURES...STAYED CLOSE TO GUIDANCE AS MID LEVEL CLOUDS
SHOULD HELP TO LIMIT RADIATIONAL COOLING EVEN FOR LOCATIONS THAT
STILL HAVE SNOW PACK.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
LAST PIECE OF MID-LEVEL ENERGY MOVES THROUGH THE REGION ON FRIDAY AS
THE BROAD SCALE TROUGHING FINALLY RELINQUISHING ITS GRASP ON OUR
REGION. THE MID-LEVELS TAKE ON MORE OF A ZONAL-ISH FLOW OVER THE
WEEKEND WITH THE NEXT EMBEDDED WAVE EXPECTED BY MONDAY FOLLOWED BY
RIDGING THROUGH THE REMAINDER OF THE PERIOD.
FRIDAY - SATURDAY...HIGH PRESSURE WILL BE SQUEEZING IN LATER ON
FRIDAY FROM THE WEST-NORTHWEST. JUST AHEAD OF THE RIDGING WILL BE A
LAST DITCH EFFORT BY THE BROAD TROUGH TO PUSH A DAMPENING SHORTWAVE
THROUGH THE REGION. WITH LIMITED AMOUNTS OF MOISTURE EXPECTED WE
CONFINED THE SLIGHT CHANCE POPS TO OUR WESTERN ZONES BEFORE DRYING
OUT LATER FRIDAY AFTERNOON. AT THIS POINT THE RIDGING WILL BE ABLE
TO EXERT ITSELF UPON THE AREA AND WE REMAIN DRY, BUT COLD, THROUGH
SATURDAY.
SUNDAY - MONDAY...ZONAL-ISH FLOW TURNS A BIT SHARPER AS THE BROAD
TROUGH RELOADS WELL TO OUR WEST. ANOTHER PASSING SHORTWAVE ALOFT
APPROACHES AND PUSHES A COLD FRONT THROUGH THE REGION LATE SUNDAY
INTO MONDAY MORNING. OUT AHEAD OF THE FRONT TEMPERATURES ARE ABLE TO
MODIFY A BIT THANKS TO THE DEPARTING HIGH PRESSURE NOW OFF THE COAST
AND A LIGHT RETURN FLOW SETTING UP. WE CONFINED THE HIGHER POPS
UNTIL LATE SUNDAY NIGHT JUST AHEAD AND WITH THE FRONTAL PASSAGE.
DECENT AMOUNT OF THETA-E ADVECTION OCCURRING AHEAD OF THE FRONT WITH
ENOUGH LIFT FOR A LIGHT SNOW TO START BEFORE A WINTRY MIX/
CHANGEOVER, MOSTLY ACROSS THE SOUTHERN HALF OF THE CWA, BY MONDAY
MORNING. THE FRONT THEN MOVES THROUGH AND ALLOWS FOR ANOTHER SHOT OF
COOLER AIR AND MORE PRECIPITATION PHASE CHANGES.
TUESDAY - WEDNEDSAY...WITH THE COLD FRONT TO OUR EAST AND A BRIEF
SHOT OF HIGH PRESSURE BEHIND IT, THE NEXT SYSTEM, FORMING DEEP IN
THE SOUTH, BEGINS TO ENTER THE REGION FROM THE SOUTHWEST LATER ON
TUESDAY. A LIGHT ONSHORE FLOW WILL HELP TO ENHANCE THE LOW-LEVEL
MOISTURE FLUX WHEN COMBINED WITH A STRONG LOW-LEVEL SOUTHERLY SURGE
OF WARM/MOIST AIR. THIS EVENT COULD HAVE A COPIOUS AMOUNT OF
MOISTURE WITH IT, GIVEN ITS ORIGIN AND THE MODIFYING AIRMASS WE`LL
HAVE IN PLACE. TOO EARLY FOR PTYPE SPECIFICS BUT IT DOES APPEAR TO
BE A MIXED EVENT. IT SHOULD BE NOTED THAT SEVERAL TIMES THIS WINTER
THE NUMERICAL GUIDANCE HAS BEEN TOO STRONG WITH THE LOW PRESSURE AS
IT CROSSES THE MID-WEST AND THEREFORE OVER AMPLIFIES/WARMS THE LOW-
LEVELS. A SHIFT TO THE EAST AND A WEAKER SOLUTION WOULD LEAD TO LESS
MIXING.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
SNOW IS TRYING TO BUILD FURTHER NORTH THROUGH THE REGION. HOWEVER, IT
IS ENCOUNTERING A WALL OF DRY AIR. WESTERN TAF SITES, KABE AND
KRDG, WILL LIKELY NOT SEE ANY SNOW AT ALL. FOR THE DELAWARE VALLEY
SITES, KPHL, KPNE, AND KTTN, A 2 TO 3 HOUR PERIOD OF MOSTLY LIGHT
SNOW IS POSSIBLE BETWEEN 12 AND 16Z (SOONER AT KILG, WHILE KTTN
WILL BE THE LAST TO BE AFFECTED). THOUGH IT APPEARS THE MAIN
WINDOW FOR THIS WILL BE ENDING SOON BY 14Z-15Z. AT KILG, KMIV AND
KACY, MOSTLY LIGHT BUT SOME PERIODS OF MODERATE TO HEAVY SNOW SNOW
WILL BE POSSIBLE FOR A MAJORITY OF THE MORNING. BY 18Z HOWEVER,
SNOW SHOULD BE OUT OF THE REGION. TAFS REFLECT MORE OPTIMISTIC
CONDITIONS THAN WHAT IS DEPICTED IN THE GFS LAMP AS IT APPEARS TO
BE UNDERESTIMATING THE DRY AIR IN THE BOUNDARY LAYER. THUS...THINK
THAT ONCE THE SNOW MOVES OUT CONDITIONS SHOULD RETURN TO
VFR...THOUGH THERE REMAINS A SMALL CHANCE THAT MVFR CEILINGS WILL
LINGER THROUGH THE DAY.
OVERNIGHT, CEILINGS SHOULD INCREASE BACK TO VFR, ALBEIT THE LOWER
END OF VFR. THERE IS SOME RISK OF BR DEVELOPING ACROSS THE REGION,
AND A LOW CHANCE OF ANOTHER ROUND OF -SN FOR KRDG AND KABE AFTER
06Z. HOWEVER, IN BOTH CASES THE CHANCE IS TOO LOW TO MENTION IN THE
TAFS AT THIS TIME.
OUTLOOK...
FRIDAY - SATURDAY...MOSTLY VFR. SLIGHT CHANCE FOR EARLY
AFTERNOON MVFR SNOW SHOWERS. NORTHERLY WINDS PREVAIL AS HIGH
PRESSURE NOSES IN FROM THE WEST.
SUNDAY - MONDAY...VFR TO START. CONDITIONS DETERIORATE LATE IN THE
DAY AS THE NEXT SYSTEM APPROACHES FROM THE WEST-SOUTHWEST. SOUTHERLY
WINDS EXPECTED.
&&
.MARINE...
WINDS SHOULD INCREASE SOON RESULTING IN SCA CONDITIONS FOR THE LOWER
BAY AND THE ATLANTIC COASTAL WATERS FOR MUCH OF THE DAY. WITH THE
INCREASE IN WINDS, SEAS WILL SLOWLY BUILD AS WELL (PRIMARILY ON THE
OCEAN). FOR THE OCEAN WATERS A FEW GUSTS ABOVE 30 KT ARE POSSIBLE
PRIMARILY LATE THIS MORNING INTO EARLY THIS AFTERNOON. BY EARLY THIS
EVENING, WINDS SHOULD DIMINISH BELOW 25KT, BUT SEAS ON THE OCEAN
WILL BE SLOW TO DIMINISH. THUS, HAVE EXTENDED THE SCA FOR THE OCEAN
ZONES THROUGH 06Z FOR THE NORTHERN WATERS AND 11Z FOR THE SOUTHERN
WATERS.
OUTLOOK...
FRIDAY - SATURDAY...SUB-SCA EXPECTED, THOUGH PERSISTENT
NORTHEAST WINDS MAY ALLOW FOR BUILDING SEAS ACROSS OUR SOUTHERN
ZONES.
SUNDAY - MONDAY...POSSIBLE SCA CONDITIONS LATE ON SUNDAY AHEAD OF AN
APPROACHING COLD FRONT. INCREASING SOUTHERLY WINDS AND BUILDING SEAS
EXPECTED.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>027.
DE...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001-002.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ003-
004.
MD...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MDZ008-012-015-019-020.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ450-451.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ431.
&&
$$
SYNOPSIS...HEAVENER
NEAR TERM...JOHNSON
SHORT TERM...JOHNSON
LONG TERM...HEAVENER
AVIATION...GAINES/HEAVENER/JOHNSON
MARINE...HEAVENER/JOHNSON
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
652 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE SYSTEM WILL QUICKLY MOVE OFF THE NORTH CAROLINA COAST
TODAY WHILE ANOTHER ARCTIC HIGH PRESSURE SYSTEM NOSES IN BY FRIDAY.
THE HIGH WILL MOVE OFF THE COAST BY EARLY NEXT WEEK FOLLOWED BY
ANOTHER COLD FRONT PASSAGE ON MONDAY. A LOW PRESSURE EJECTS OUT OF
THE CENTRAL PLAINS AND CROSSES OUR REGION ON TUESDAY INTO WEDNESDAY.
THE LOWS ASSOCIATED COLD FRONT PUSHES THROUGH LATER ON WEDNESDAY
WITH ANOTHER EXPANSIVE HIGH PRESSURE SYSTEM FILLING IN BEHIND IT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
630 AM UPDATE...NO MAJOR CHANGES FROM THE PREVIOUS FORECAST.
HEAVIER SNOW BANDS MOVING THROUGH SOUTHERN DELMARVA AND FAR
SOUTHERN NJ NOW. EXPECT THE BULK OF THE SNOW TO OCCUR BETWEEN NOW
AND LATE THIS MORNING.
PREVIOUS NEAR TERM DISCUSSION...THE LATEST COASTAL LOW CONTINUES
TO LIFT NORTHEAST OFF THE CAROLINA COAST. SNOW HAS BEEN REPORTED
IN SOUTHERN DELMARVA, BUT AS OF 330 AM REMAINS JUST SOUTH OF OUR
CWA.
TIMING STILL LOOKS ON TRACK WITH A MAJORITY OF THE SNOW OCCURRING
FROM NOW THROUGH THE MORNING RUSH HOUR, THEN THE SNOW TAPERING OFF
MID DAY THROUGH THE AFTERNOON HOURS.
AS FOR AMOUNTS, TRENDED THE AMOUNTS DOWN SLIGHTLY FOR THE FOLLOWING
REASONS. FIRST, THERE HAS BEEN PERSISTENT CONVECTION OFF THE NC
COAST WHICH COULD LIMIT THE MOISTURE AND ENERGY THIS FAR NORTH.
SECOND, LATEST WV AND IR SATELLITE IMAGERY SHOW A MID AND UPPER LEVEL
DRY SLOT QUICKLY SLIDING IN FROM THE SW. AS OF 3 AM THE DRY SLOT
EXTENDED FROM SW VA UP TO THE POCONOS. THIS COULD HAVE A SIGNIFICANT
IMPACT FOR THE WESTERN EXTENT OF THE PRECIP. ALSO RELATED TO
SATELLITE, EVEN EAST OF THE DRY SLOT OVER SOUTHERN DELMARVA AND THE
ATLANTIC COASTAL WATERS THERE HAS BEEN A CLOUD TOP WARMING TREND FOR
THE LAST FEW HOURS. FINALLY, MOST OF THE HEAVIER BANDS OF SNOW WE`VE
SEEN UP STREAM SEEM TO BE ASSOCIATED WITH A BAND OF FRONTOGENESIS
WHICH HAS BEEN WELL DEPICTED BY THE RAP. THE RAP SHOWS THIS
FRONTOGENESIS BAND SLIDING EAST BEFORE IT GETS AS FAR AS OUR REGION.
FOR NOW THOUGH, WILL KEEP THE WINTER WEATHER ADVISORY AND WINTER
STORM WARNING AS SOME MODEL SOUNDINGS CONTINUE TO SHOW MODEST OMEGA
VALUES WITHIN THE DENDRITIC GROWTH ZONE, PRIMARILY IN THE FEW HOURS
AROUND THE MORNING RUSH HOUR. THUS THE TIMING OF THE SNOW MAY BE
MORE IMPACTFUL THAN THE ACTUAL AMOUNTS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
TONIGHT, A WEAK MID LEVEL SHORT WAVE TROUGH LOOKS TO SIDESWIPE THE
NORTHWESTERN PORTIONS OF OUR REGION. AS A RESULT...LIGHT SNOW IS
POSSIBLE GENERALLY NORTH AND WEST OF THE PHILLY SUBURBS. MOISTURE
AVAILABILITY IS GOING TO BE PROBLEMATIC FOR THIS SYSTEM AS THERE IS
LITTLE CHANCE FOR ANY MOISTURE ADVECTION BEHIND TODAYS SYSTEM.
THEREFORE, ANY SNOW AMOUNTS SHOULD BE BELOW AN INCH.
AS FOR TEMPERATURES...STAYED CLOSE TO GUIDANCE AS MID LEVEL CLOUDS
SHOULD HELP TO LIMIT RADIATIONAL COOLING EVEN FOR LOCATIONS THAT
STILL HAVE SNOW PACK.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
LAST PIECE OF MID-LEVEL ENERGY MOVES THROUGH THE REGION ON FRIDAY AS
THE BROAD SCALE TROUGHING FINALLY RELINQUISHING ITS GRASP ON OUR
REGION. THE MID-LEVELS TAKE ON MORE OF A ZONAL-ISH FLOW OVER THE
WEEKEND WITH THE NEXT EMBEDDED WAVE EXPECTED BY MONDAY FOLLOWED BY
RIDGING THROUGH THE REMAINDER OF THE PERIOD.
FRIDAY - SATURDAY...HIGH PRESSURE WILL BE SQUEEZING IN LATER ON
FRIDAY FROM THE WEST-NORTHWEST. JUST AHEAD OF THE RIDGING WILL BE A
LAST DITCH EFFORT BY THE BROAD TROUGH TO PUSH A DAMPENING SHORTWAVE
THROUGH THE REGION. WITH LIMITED AMOUNTS OF MOISTURE EXPECTED WE
CONFINED THE SLIGHT CHANCE POPS TO OUR WESTERN ZONES BEFORE DRYING
OUT LATER FRIDAY AFTERNOON. AT THIS POINT THE RIDGING WILL BE ABLE
TO EXERT ITSELF UPON THE AREA AND WE REMAIN DRY, BUT COLD, THROUGH
SATURDAY.
SUNDAY - MONDAY...ZONAL-ISH FLOW TURNS A BIT SHARPER AS THE BROAD
TROUGH RELOADS WELL TO OUR WEST. ANOTHER PASSING SHORTWAVE ALOFT
APPROACHES AND PUSHES A COLD FRONT THROUGH THE REGION LATE SUNDAY
INTO MONDAY MORNING. OUT AHEAD OF THE FRONT TEMPERATURES ARE ABLE TO
MODIFY A BIT THANKS TO THE DEPARTING HIGH PRESSURE NOW OFF THE COAST
AND A LIGHT RETURN FLOW SETTING UP. WE CONFINED THE HIGHER POPS
UNTIL LATE SUNDAY NIGHT JUST AHEAD AND WITH THE FRONTAL PASSAGE.
DECENT AMOUNT OF THETA-E ADVECTION OCCURRING AHEAD OF THE FRONT WITH
ENOUGH LIFT FOR A LIGHT SNOW TO START BEFORE A WINTRY MIX/
CHANGEOVER, MOSTLY ACROSS THE SOUTHERN HALF OF THE CWA, BY MONDAY
MORNING. THE FRONT THEN MOVES THROUGH AND ALLOWS FOR ANOTHER SHOT OF
COOLER AIR AND MORE PRECIPITATION PHASE CHANGES.
TUESDAY - WEDNEDSAY...WITH THE COLD FRONT TO OUR EAST AND A BRIEF
SHOT OF HIGH PRESSURE BEHIND IT, THE NEXT SYSTEM, FORMING DEEP IN
THE SOUTH, BEGINS TO ENTER THE REGION FROM THE SOUTHWEST LATER ON
TUESDAY. A LIGHT ONSHORE FLOW WILL HELP TO ENHANCE THE LOW-LEVEL
MOISTURE FLUX WHEN COMBINED WITH A STRONG LOW-LEVEL SOUTHERLY SURGE
OF WARM/MOIST AIR. THIS EVENT COULD HAVE A COPIOUS AMOUNT OF
MOISTURE WITH IT, GIVEN ITS ORIGIN AND THE MODIFYING AIRMASS WE`LL
HAVE IN PLACE. TOO EARLY FOR PTYPE SPECIFICS BUT IT DOES APPEAR TO
BE A MIXED EVENT. IT SHOULD BE NOTED THAT SEVERAL TIMES THIS WINTER
THE NUMERICAL GUIDANCE HAS BEEN TOO STRONG WITH THE LOW PRESSURE AS
IT CROSSES THE MID-WEST AND THEREFORE OVER AMPLIFIES/WARMS THE LOW-
LEVELS. A SHIFT TO THE EAST AND A WEAKER SOLUTION WOULD LEAD TO LESS
MIXING.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
CEILINGS SHOULD GRADUALLY LOWER THROUGH 12Z AS SNOW APPROACHES FROM
THE SOUTH. STILL SOME UNCERTAINTY IF THE WESTERN TAF SITES, KABE AND
KRDG, WILL SEE ANY SNOW AT ALL. FOR THE DELAWARE VALLEY SITES, KPHL,
KPNE, AND KTTN, A 2 TO 3 HOUR PERIOD OF MOSTLY LIGHT SNOW IS
POSSIBLE BETWEEN 12 AND 16Z (SOONER AT KILG, WHILE KTTN WILL BE
THE LAST TO BE AFFECTED). AT KILG, KMIV AND KACY, MOSTLY LIGHT
BUT SOME PERIODS OF MODERATE TO HEAVY SNOW SNOW WILL BE POSSIBLE
FOR A MAJORITY OF THE MORNING. BY 18Z HOWEVER, SNOW SHOULD BE
OUT OF THE REGION. TAFS REFLECT MORE OPTOMISTIC CONDITIONS THAN
WHAT IS DEPICTED IN THE GFS LAMP AS IT APPEARS TO BE
UNDERESTIMATING THE DRY AIR IN THE BOUNDARY LAYER. THUS...THINK
THAT ONCE THE SNOW MOVES OUT CONDITIONS SHOULD RETURN TO
VFR...THOUGH THERE REMAINS A SMALL CHANCE THAT MVFR CEILINGS WILL
LINGER THROUGH THE DAY.
OVERNIGHT, CEILINGS SHOULD INCREASE BACK TO VFR, ALBEIT THE LOWER
END OF VFR. THERE IS SOME RISK OF BR DEVELOPING ACROSS THE REGION,
AND A LOW CHANCE OF ANOTHER ROUND OF -SN FOR KRDG AND KABE AFTER
06Z. HOWEVER, IN BOTH CASES THE CHANCE IS TOO LOW TO MENTION IN THE
TAFS AT THIS TIME.
OUTLOOK...
FRIDAY - SATURDAY...MOSTLY VFR. SLIGHT CHANCE FOR EARLY
AFTERNOON MVFR SNOW SHOWERS. NORTHERLY WINDS PREVAIL AS HIGH
PRESSURE NOSES IN FROM THE WEST.
SUNDAY - MONDAY...VFR TO START. CONDITIONS DETERIORATE LATE IN THE
DAY AS THE NEXT SYSTEM APPROACHES FROM THE WEST-SOUTHWEST. SOUTHERLY
WINDS EXPECTED.
&&
.MARINE...
WINDS SHOULD INCREASE SOON RESULTING IN SCA CONDITIONS FOR THE LOWER
BAY AND THE ATLANTIC COASTAL WATERS FOR MUCH OF THE DAY. WITH THE
INCREASE IN WINDS, SEAS WILL SLOWLY BUILD AS WELL (PRIMARILY ON THE
OCEAN). FOR THE OCEAN WATERS A FEW GUSTS ABOVE 30 KT ARE POSSIBLE
PRIMARILY LATE THIS MORNING INTO EARLY THIS AFTERNOON. BY EARLY THIS
EVENING, WINDS SHOULD DIMINISH BELOW 25KT, BUT SEAS ON THE OCEAN
WILL BE SLOW TO DIMINISH. THUS, HAVE EXTENDED THE SCA FOR THE OCEAN
ZONES THROUGH 06Z FOR THE NORTHERN WATERS AND 11Z FOR THE SOUTHERN
WATERS.
OUTLOOK...
FRIDAY - SATURDAY...SUB-SCA EXPECTED, THOUGH PERSISTENT
NORTHEAST WINDS MAY ALLOW FOR BUILDING SEAS ACROSS OUR SOUTHERN
ZONES.
SUNDAY - MONDAY...POSSIBLE SCA CONDITIONS LATE ON SUNDAY AHEAD OF AN
APPROACHING COLD FRONT. INCREASING SOUTHERLY WINDS AND BUILDING SEAS
EXPECTED.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>027.
DE...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001-002.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ003-
004.
MD...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MDZ008-012-015-019-020.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ450-451.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ431.
&&
$$
SYNOPSIS...HEAVENER
NEAR TERM...JOHNSON
SHORT TERM...JOHNSON
LONG TERM...HEAVENER
AVIATION...HEAVENER/JOHNSON
MARINE...HEAVENER/JOHNSON
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
424 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE SYSTEM WILL QUICKLY MOVE OFF THE NORTH CAROLINA COAST
TODAY WHILE ANOTHER ARCTIC HIGH PRESSURE SYSTEM NOSES IN BY FRIDAY.
THE HIGH WILL MOVE OFF THE COAST BY EARLY NEXT WEEK FOLLOWED BY
ANOTHER COLD FRONT PASSAGE ON MONDAY. A LOW PRESSURE EJECTS OUT OF
THE CENTRAL PLAINS AND CROSSES OUR REGION ON TUESDAY INTO WEDNESDAY.
THE LOWS ASSOCIATED COLD FRONT PUSHES THROUGH LATER ON WEDNESDAY
WITH ANOTHER EXPANSIVE HIGH PRESSURE SYSTEM FILLING IN BEHIND IT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST COASTAL LOW CONTINUES TO LIFT NORTHEAST OFF THE CAROLINA
COAST. SNOW HAS BEEN REPORTED IN SOUTHERN DELMARVA, BUT AS OF 330 AM
REMAINS JUST SOUTH OF OUR CWA.
TIMING STILL LOOKS ON TRACK WITH A MAJORITY OF THE SNOW OCCURRING
FROM NOW THROUGH THE MORNING RUSH HOUR, THEN THE SNOW TAPERING OFF
MID DAY THROUGH THE AFTERNOON HOURS.
AS FOR AMOUNTS, TRENDED THE AMOUNTS DOWN SLIGHTLY FOR THE FOLLOWING
REASONS. FIRST, THERE HAS BEEN PERSISTENT CONVECTION OFF THE NC
COAST WHICH COULD LIMIT THE MOISTURE AND ENERGY THIS FAR NORTH.
SECOND, LATEST WV AND IR SATELLITE IMAGERY SHOW A MID AND UPPER LEVEL
DRY SLOT QUICKLY SLIDING IN FROM THE SW. AS OF 3 AM THE DRY SLOT
EXTENDED FROM SW VA UP TO THE POCONOS. THIS COULD HAVE A SIGNIFICANT
IMPACT FOR THE WESTERN EXTENT OF THE PRECIP. ALSO RELATED TO
SATELLITE, EVEN EAST OF THE DRY SLOT OVER SOUTHERN DELMARVA AND THE
ATLANTIC COASTAL WATERS THERE HAS BEEN A CLOUD TOP WARMING TREND FOR
THE LAST FEW HOURS. FINALLY, MOST OF THE HEAVIER BANDS OF SNOW WE`VE
SEEN UP STREAM SEEM TO BE ASSOCIATED WITH A BAND OF FRONTOGENESIS
WHICH HAS BEEN WELL DEPICTED BY THE RAP. THE RAP SHOWS THIS
FRONTOGENESIS BAND SLIDING EAST BEFORE IT GETS AS FAR AS OUR REGION.
FOR NOW THOUGH, WILL KEEP THE WINTER WEATHER ADVISORY AND WINTER
STORM WARNING AS SOME MODEL SOUNDINGS CONTINUE TO SHOW MODEST OMEGA
VALUES WITHIN THE DENDRITIC GROWTH ZONE, PRIMARILY IN THE FEW HOURS
AROUND THE MORNING RUSH HOUR. THUS THE TIMING OF THE SNOW MAY BE
MORE IMPACTFUL THAN THE ACTUAL AMOUNTS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
TONIGHT, A WEAK MID LEVEL SHORT WAVE TROUGH LOOKS TO SIDESWIPE THE
NORTHWESTERN PORTIONS OF OUR REGION. AS A RESULT...LIGHT SNOW IS
POSSIBLE GENERALLY NORTH AND WEST OF THE PHILLY SUBURBS. MOISTURE
AVAILABILITY IS GOING TO BE PROBLEMATIC FOR THIS SYSTEM AS THERE IS
LITTLE CHANCE FOR ANY MOISTURE ADVECTION BEHIND TODAYS SYSTEM.
THEREFORE, ANY SNOW AMOUNTS SHOULD BE BELOW AN INCH.
AS FOR TEMPERATURES...STAYED CLOSE TO GUIDANCE AS MID LEVEL CLOUDS
SHOULD HELP TO LIMIT RADIATIONAL COOLING EVEN FOR LOCATIONS THAT
STILL HAVE SNOW PACK.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
LAST PIECE OF MID-LEVEL ENERGY MOVES THROUGH THE REGION ON FRIDAY AS
THE BROAD SCALE TROUGHING FINALLY RELINQUISHING ITS GRASP ON OUR
REGION. THE MID-LEVELS TAKE ON MORE OF A ZONAL-ISH FLOW OVER THE
WEEKEND WITH THE NEXT EMBEDDED WAVE EXPECTED BY MONDAY FOLLOWED BY
RIDGING THROUGH THE REMAINDER OF THE PERIOD.
FRIDAY - SATURDAY...HIGH PRESSURE WILL BE SQUEEZING IN LATER ON
FRIDAY FROM THE WEST-NORTHWEST. JUST AHEAD OF THE RIDGING WILL BE A
LAST DITCH EFFORT BY THE BROAD TROUGH TO PUSH A DAMPENING SHORTWAVE
THROUGH THE REGION. WITH LIMITED AMOUNTS OF MOISTURE EXPECTED WE
CONFINED THE SLIGHT CHANCE POPS TO OUR WESTERN ZONES BEFORE DRYING
OUT LATER FRIDAY AFTERNOON. AT THIS POINT THE RIDGING WILL BE ABLE
TO EXERT ITSELF UPON THE AREA AND WE REMAIN DRY, BUT COLD, THROUGH
SATURDAY.
SUNDAY - MONDAY...ZONAL-ISH FLOW TURNS A BIT SHARPER AS THE BROAD
TROUGH RELOADS WELL TO OUR WEST. ANOTHER PASSING SHORTWAVE ALOFT
APPROACHES AND PUSHES A COLD FRONT THROUGH THE REGION LATE SUNDAY
INTO MONDAY MORNING. OUT AHEAD OF THE FRONT TEMPERATURES ARE ABLE TO
MODIFY A BIT THANKS TO THE DEPARTING HIGH PRESSURE NOW OFF THE COAST
AND A LIGHT RETURN FLOW SETTING UP. WE CONFINED THE HIGHER POPS
UNTIL LATE SUNDAY NIGHT JUST AHEAD AND WITH THE FRONTAL PASSAGE.
DECENT AMOUNT OF THETA-E ADVECTION OCCURRING AHEAD OF THE FRONT WITH
ENOUGH LIFT FOR A LIGHT SNOW TO START BEFORE A WINTRY MIX/
CHANGEOVER, MOSTLY ACROSS THE SOUTHERN HALF OF THE CWA, BY MONDAY
MORNING. THE FRONT THEN MOVES THROUGH AND ALLOWS FOR ANOTHER SHOT OF
COOLER AIR AND MORE PRECIPITATION PHASE CHANGES.
TUESDAY - WEDNEDSAY...WITH THE COLD FRONT TO OUR EAST AND A BRIEF
SHOT OF HIGH PRESSURE BEHIND IT, THE NEXT SYSTEM, FORMING DEEP IN
THE SOUTH, BEGINS TO ENTER THE REGION FROM THE SOUTHWEST LATER ON
TUESDAY. A LIGHT ONSHORE FLOW WILL HELP TO ENHANCE THE LOW-LEVEL
MOISTURE FLUX WHEN COMBINED WITH A STRONG LOW-LEVEL SOUTHERLY SURGE
OF WARM/MOIST AIR. THIS EVENT COULD HAVE A COPIOUS AMOUNT OF
MOISTURE WITH IT, GIVEN ITS ORIGIN AND THE MODIFYING AIRMASS WE`LL
HAVE IN PLACE. TOO EARLY FOR PTYPE SPECIFICS BUT IT DOES APPEAR TO
BE A MIXED EVENT. IT SHOULD BE NOTED THAT SEVERAL TIMES THIS WINTER
THE NUMERICAL GUIDANCE HAS BEEN TOO STRONG WITH THE LOW PRESSURE AS
IT CROSSES THE MID-WEST AND THEREFORE OVER AMPLIFIES/WARMS THE LOW-
LEVELS. A SHIFT TO THE EAST AND A WEAKER SOLUTION WOULD LEAD TO LESS
MIXING.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
CEILINGS SHOULD GRADUALLY LOWER THROUGH 12Z AS SNOW APPROACHES FROM
THE SOUTH. STILL SOME UNCERTAINTY IF THE WESTERN TAF SITES, KABE AND
KRDG, WILL SEE ANY SNOW AT ALL. FOR THE DELAWARE VALLEY SITES, KPHL,
KILG, KPNE, AND KTTN, A 2 TO 3 HOUR PERIOD OF MOSTLY LIGHT SNOW IS
POSSIBLE BETWEEN 12 AND 16Z (SOONER AT KILG, WHILE KTTN WILL BE THE
LAST TO BE AFFECTED). AT KMIV AND KACY, MOSTLY LIGHT BUT SOME
PERIODS OF MODERATE TO HEAVY SNOW SNOW WILL BE POSSIBLE FOR A
MAJORITY OF THE MORNING. BY 18Z HOWEVER, SNOW SHOULD BE MOVING OUT
OF THE REGION, THOUGH TIME HEIGHT DISPLAYS OF THE GFS SHOW MVFR
CEILINGS LINGERING THROUGH THE DAY TIME HOURS.
OVERNIGHT, CEILINGS SHOULD INCREASE BACK TO VFR, ALBEIT THE LOWER
END OF VFR. THERE IS SOME RISK OF BR DEVELOPING ACROSS THE REGION,
AND A LOW CHANCE OF ANOTHER ROUND OF -SN FOR KRDG AND KABE AFTER
06Z. HOWEVER, IN BOTH CASES THE CHANCE IS TOO LOW TO MENTION IN THE
TAFS AT THIS TIME.
OUTLOOK...
FRIDAY - SATURDAY...MOSTLY VFR. SLIGHT CHANCE FOR EARLY
AFTERNOON MVFR SNOW SHOWERS. NORTHERLY WINDS PREVAIL AS HIGH
PRESSURE NOSES IN FROM THE WEST.
SUNDAY - MONDAY...VFR TO START. CONDITIONS DETERIORATE LATE IN THE
DAY AS THE NEXT SYSTEM APPROACHES FROM THE WEST-SOUTHWEST. SOUTHERLY
WINDS EXPECTED.
&&
.MARINE...
WINDS SHOULD INCREASE SOON RESULTING IN SCA CONDITIONS FOR THE LOWER
BAY AND THE ATLANTIC COASTAL WATERS FOR MUCH OF THE DAY. WITH THE
INCREASE IN WINDS, SEAS WILL SLOWLY BUILD AS WELL (PRIMARILY ON THE
OCEAN). FOR THE OCEAN WATERS A FEW GUSTS ABOVE 30 KT ARE POSSIBLE
PRIMARILY LATE THIS MORNING INTO EARLY THIS AFTERNOON. BY EARLY THIS
EVENING, WINDS SHOULD DIMINISH BELOW 25KT, BUT SEAS ON THE OCEAN
WILL BE SLOW TO DIMINISH. THUS, HAVE EXTENDED THE SCA FOR THE OCEAN
ZONES THROUGH 06Z FOR THE NORTHERN WATERS AND 11Z FOR THE SOUTHERN
WATERS.
OUTLOOK...
FRIDAY - SATURDAY...SUB-SCA EXPECTED, THOUGH PERSISTENT
NORTHEAST WINDS MAY ALLOW FOR BUILDING SEAS ACROSS OUR SOUTHERN
ZONES.
SUNDAY - MONDAY...POSSIBLE SCA CONDITIONS LATE ON SUNDAY AHEAD OF AN
APPROACHING COLD FRONT. INCREASING SOUTHERLY WINDS AND BUILDING SEAS
EXPECTED.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>020-026-027.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ021>025.
DE...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ003-
004.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ002.
MD...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MDZ008.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MDZ012-015-019-020.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ450-451.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ431.
&&
$$
SYNOPSIS...HEAVENER
NEAR TERM...JOHNSON
SHORT TERM...JOHNSON
LONG TERM...HEAVENER
AVIATION...HEAVENER/JOHNSON
MARINE...HEAVENER/JOHNSON
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
8 PM EST FRI FEB 27 2015
.DISCUSSION...
CURRENT-OVERNIGHT...BOTH THE RAP AND HRRR SHOW THE INVERTED TROUGH
OVER THE COASTAL WATERS MOVING WEST AND FLATTENING A LITTLE IN THE
NORTHEAST TO EAST LARGE SCALE FLOW OVERNIGHT. THE VERTICAL WIND
PROFILERS ARE SHOWING A SLOW SHIFT TO THE NORTH NORTHEAST PAST
COUPLE OF HOURS. THIS SHOULD RESULT IN WINDS OVER WATER AND AT THE
COAST TO BECOME NORTHEAST WHILE REMAINING MORE NORTHERLY INLAND.
MODEL TIME HEIGHT CROSS SECTIONS ALONG WITH WATER VAPOR AND IR LOOPS
SHOW THE SAME...MOIST AND WARMER SOUTH TO SOUTHWEST FLOW ABOVE THE
SURFACE MOVING OVERTOP A SHALLOW COOLER NORTHEAST TO EAST FLOW. THIS
SET UP INDICATES CONTINUED LOW CLOUDS AND OCCASIONAL SPRINKLES OR
LIGHT RAIN COMING OFF THE ATLANTIC AND WORKING THEIR WAY WELL INLAND
BEFORE DISSIPATING. CURRENT FORECAST GRIDS AND FORECAST DEPICTS THIS
WELL.
THE EVENING UPDATE REMOVES MENTION OF THUNDER.
PREVIOUS ZONES DISCUSSION
CURRENT...TODAY`S WEATHER IN CENTRAL FL WAS GRACIOUSLY DONATED TO US
BY THE CITY OF LONDON. OR WAS IT SEATTLE? TAKE YOUR PICK...EITHER
WAY THIS HAS BEEN A TRULY DREARY DAY. S-SW WINDS OVERRUNNING THE 2-
3KFT NRLY POST-FRONTAL AIR MASS HAS PRODUCED WIDESPREAD LOW CLOUDS
WITH MIST/DRIZZLE AND OCNL LIGHT RAIN COVERING THE SRN 2/3 (ISM TO
MCO TO NORTH OF TTS) ADDING TO THE MISERY ARE 10-20MPH NRLY
WINDS...MAKING THE CHILL THAT MUCH MORE BITING. IT`S BECOME
PAINFULLY APPARENT THAT SHAVING A COUPLE DEGS OFF OF MAX TEMPS WAS A
SMALL STEP IN THE RIGHT DIRECTION...THE KEY WORD BEING "SMALL".
ABOUT THE ONLY AREAS THAT ARE SEEING OR WILL SEE 60F TODAY ARE THOSE
THAT NEVER FELL BELOW 60F BEHIND THE FROPA THU MORNING OR OVERNIGHT
(I.E THE TREASURE COAST). OTHERWISE...AFTERNOON TEMPS HAVE EITHER
HELD STEADY IN THE M50S-L60S OR HAVE ACTUALLY DROPPED A DEGREE OR
TWO SINCE THIS MORNING. 00Z MOS GUIDANCE WILL WIND UP BUSTING HIGH
BY A FULL 2-3 CATS.
OVERNIGHT...AS THE LARGE COLD HIGH TO THE NORTH OF FL BUILDS EWD...
BLYR WINDS WINDS WILL VEER TO NE BUT WILL BE SLOWER TO DO SO OVER
LAND AS NRLY DRAINAGE FLOW WILL HOLD FIRM OVER MOST OF THE AREA
OVERNIGHT. SURFACE WINDS HAVE ALREADY SHIFTED TO NE WELL OFFSHORE
OVER THE ATLC AS 41010/SPGF1 ARE E OF THE INVERTED TROUGH AXIS...
WHICH IS STILL APPARENT ON BOTH RADAR/VISIBLE SAT IMAGERY). THIS
TROUGH OR COASTAL FRONT WILL CREEP CLOSER TO THE COAST LATE THIS
EVENING...AND EVENTUALLY PUSH ONSHORE PRIOR TO MIDNIGHT ALONG THE
TREASURE COAST...THEN SLOWLY EDGE WEST TOWARD THE INTERIOR THROUGH
SUNRISE. WE`LL LIKELY SEE TEMPS REMAIN NEARLY STEADY WEST OF THE
BOUNDARY TONIGHT...MUCH LIKE THEY DID ALL MORNING AND AFTERNOON...
WHILE MINS OCCUR THIS EVENING ALONG COASTAL AREAS...BEFORE JUMPING
SEVERAL DEGREES WITH THE PASSAGE OF THE TROUGH/COASTAL FRONT.
SAT...TROUGH WILL PUSH WESTWARD ACROSS THE PENINSULA WITH MILDER
MARINE AIR AND OCNL BREEZY EAST WINDS BEHIND THE BDRY OVERSPREADING
THE REMAINDER OF THE CWA. WHILE TEMPS WILL BE MUCH WARMER THAN TODAY
...STILL EXPECT WIDESPREAD CLOUDS AND HIGH RAIN CHANCES (60 COAST/50
INLAND) AS LOW LEVEL MCONVG WILL BE ENHANCED OVER THE PENINSULA. AS
SUCH...WENT BELOW MOS GUIDANCE FOR MAXES BY 1-2F AREAWIDE.
SAT NIGHT...BREEZY CONDITIONS WILL CONTINUE NEAR THE COAST WITH
PRESSURE GRADIENT REMAINING TIGHT. POPS IN SCATTERED/CHANCE CATEGORY
ALL AREAS...BUT COASTAL ZONES FAVORED FOR THE HIGHER VALUES WITH
ONSHORE MOVING ATLANTIC SHOWERS. MILD OVERNIGHT MINS RANGING FROM
MAINLY LOW/MID 60S INTERIOR/VOLUSIA AND UPPER 60S NEAR 70S TREASURE
COAST.
SUNDAY...EASTERLY FLOW ESTABLISHED WITH HIGH PRESSURE CENTER PUSHING
OFF THE MID ATLANTIC COAST TO THE NORTH. PRESSURE GRADIENT WEAKENS A
LITTLE OVER SATURDAY BUT MAY CONTINUE TO BE A LITTLE BREEZY AT THE
COAST. MOISTURE AND PLENTY OF CLOUDS HANGING AROUND...HAVE POPS AT
30/40% ALL AREAS FOR CONTINUED ONSHORE MOVING COASTAL SHOWERS. THE
12Z MODEL RUNS CONTINUE TO PEAK SEAS AT 10 FEET NORTHERN OFFSHORE
EARLY SUNDAY SO ROUGH SURF CAN BE EXPECTED AT THE BEACHES.
MONDAY...LOW LEVEL FLOW CONTINUES TO VEER TOWARD THE SE AND RIDGE
ALOFT BUILDS OVER THE GULF. WARMER TEMPERATURES CAN BE EXPECTED WITH
HIGHS REACHING LOWER 80S INTERIOR AND ON THE COAST RANGING FROM MID
70S NORTHERN COAST AND UPPER 70S/NEAR 80 SOUTH. LINGERING MOISTURE
POOLED OVER NORTHERN SECTIONS AND HEATING MAY PRODUCE A FEW SHOWERS
ACROSS THE NORTHERN SECTIONS IN THE AFTERNOON.
PREVIOUS EXTENDED DISCUSSION FOLLOWS... TUE-WED...THE MID WEEK
PERIOD WILL BE WARM WITH LITTLE CHANCE FOR ANY RAIN AS A MID LVL
RIDGE TRANSITIONS FROM THE ERN GULF ACROSS FL TO THE BAHAMAS. SE
FLOW TUE AND SOUTHERLY FLOW WED WILL ALLOW HIGHS TO WARM INTO THE
UPPER 70S TO LOWER 80S. LOWS WILL BE IN THE 60S.
THU-FRI...00Z GFS INDICATES A MORE PROGRESSIVE S/W SLIDING THROUGH
THE OHIO VALLEY ON THU WHICH WOULD ALLOW A FRONTAL PASSAGE BY THU
NIGHT. 12Z/00Z ECM GUIDANCE CONTINUES A STRONGER RIDGE OVER THE AREA
FOR MID WEEK WHICH IS SLOWER TO BREAK DOWN LATE NEXT WEEK. THE ECM
ALSO SHOWS A LESS AMPLIFIED S/W SLIDING TWD THE MID ATLC RESULTING
IN FRONTAL MOISTURE JUST REACHING OUR NRN AREAS FRIDAY AS A TRAILING
FRONT IS BRIDGED BY HIGH PRESSURE TO THE NORTH. WILL LEAN TWD THE
ECMWF SOLUTION FOR NOW WHICH WILL KEEP ONLY SLIGHT SHOWER CHCS NORTH
THU AND WILL KEEP FRIDAY DRY FOR NOW UNTIL THE MODELS COME INTO
BETTER AGREEMENT.
&&
.AVIATION... PERSISTENCE FORECAST WITH IFR/MVFR CEILINGS AND MVFR
VISIBILITIES OVERNIGHT.
PREVIOUS AVIATION DISCUSSION
IFR CIGS OVC005-009 WITH MVFR VSBYS IN ST AND -RADZ/BR
HAVE OVERSPREAD AREAS SOUTH OF A KISM-KMCO-KEVB LINE...AND THE 18Z
TAF PACKAGE KEEPS IMC ACROSS THESE AREAS THROUGH 15Z SAT. WHILE MOS
SUGGEST IFR WILL SPREAD NORTH ACROSS THE NORTHERN 5 AERODROMES AFTER
00Z...STOPPED SHORT F THAT AND WENT PREVAILING BKN-OVC012-015 AFT
00Z. WILL BE CLOSELY MONITORING TRENDS.
&&
.MARINE...
CURRENT-REST OF THE NIGHT...
WINDS AT BUOY 009 HAVE COME DOWN A COUPLE OF KNOTS AS THEY SHIFT
FROM THE NORTH TO THE NORTH NORTHEAST PAST COUPLE OF HOURS. SEAS
AROUND 6 FEET. THE CMAN SITE AT SEBASTIAN INLET WAS RECORDING NORTH
NORTHWEST WINDS AROUND 22 KNOTS. THE SCRIPPS BUOYS AT 4 AND 6NM OFF
THE BEACH WERE RECORDING E 3 TO 6 FOOT SEAS. BUOY REPORTS IN LINE
WITH ONGOING MARINE FORECAST.
UPDATE TO REMOVE THUNDER FROM THE FORECAST.
PREVIOUS MARINE DISCUSSION
OVERNIGHT/SUN...MADE MINOR TWEAK TO EXTEND SCA FOR WINDS THROUGH 4
AM FOR THE ENTIRE MARINE AREA...BEFORE FULL SCA FOR WINDS/SEAS GOES
INTO EFFECT FOR SATURDAY. 12Z MODEL GUIDANCE LOWERED PEAK WINDSPEEDS
BY AROUND 5KT...AND NOW KEEP THEM BELOW 25KT FOR THE EVENT...SO FOR
NOW NO NEED TO CONSIDER ANY SORT OF ADVISORY FOR MARGINAL GALE CONDS.
SEAS BUILD TO 5-8FT LATE TONIGHT...AND 6-9FT ON SATURDAY.
SAT NIGHT-MON...12Z MODEL RUNS CONTINUE TO INDICATE SEA HEIGHTS
PEAKING OUT EARLY SUNDAY WITH UP TO 10 FEET NORTHERN OFFSHORE LEGS.
SLOW DECLINE IN WIND SPEEDS SUNDAY WITH FLOW VEERING TOWARD THE EAST
BUT SLOWER RESPONSE OF SEAS EXPECTED TO KEEP SCA CONDITIONS UP INTO
SUNDAY EVENING. SLOW TREND DOWNWARD IN SEAS CONTINUES INTO MONDAY
WITH 4-5 FEET BY LATE IN THE DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 59 66 62 75 / 30 60 50 30
MCO 58 75 62 80 / 20 50 40 40
MLB 62 74 67 77 / 40 60 50 40
VRB 65 76 68 80 / 50 60 50 40
LEE 54 70 59 79 / 20 50 40 40
SFB 57 72 60 79 / 20 50 40 40
ORL 58 74 61 80 / 20 50 40 40
FPR 66 76 69 79 / 50 60 50 40
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM SATURDAY FROM FLAGLER
BEACH TO JUPITER INLET 0-20 NM OFFSHORE.
SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 11 PM SUNDAY FROM
FLAGLER BEACH TO JUPITER INLET OUT TO 60 NM OFFSHORE.
&&
$$
SHORT TERM/AVIATION...WIMMER
LONG TERM/IMPACT WX...KELLY
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
333 AM EST THU FEB 26 2015
.DISCUSSION...
...A FEW STRONG STORMS POSSIBLE THIS MORNING WITH GUSTY WINDS...
TODAY-TONIGHT...PRE FRONTAL SQUALL LINE MOVING EASTWARD AT 40 TO
50 MPH WILL AFFECT THE NORTH HALF OF THE AREA BEFORE SUNRISE AND
AREAS SOUTHWARD THROUGH THE LATE MORNING. THE LINE SHOULD SLOW IN
SOUTHERN SECTIONS WHILE WEAKENING...BUT PERSIST THROUGH AFTERNOON
OR EARLY EVENING. LATEST HRRR MODEL SHOWS SOME REINVIGORATED
CONVECTION IN THE SOUTH THIS AFTERNOON AS SOME HEATING INTO THE
UPPER 70S OR LOWER 80S OCCURS.
DUE TO THE FAST CELL MOVEMENT...WILL HAVE TO WATCH FOR STRONG
WIND GUSTS ESPECIALLY THIS MORNING. BY AFTERNOON LOW LEVEL WIND
FIELDS WILL START TO EASE BUT STILL A QUITE FAST CELL MOTION WILL
PERSIST.
COLD FRONT WILL SLIDE INTO SOUTH FLORIDA THIS EVENING BUT
CONSIDERABLE CLOUDS WILL LINGER. ENOUGH DRYING SHOULD OCCUR TO
TAKE OUT MENTION OF SHOWER CHANCES BY LATE EVENING EXCEPT FOR THE
FAR SOUTH.
FRI-SAT...MODELS REMAIN IN FAIRLY GOOD AGREEMENT SHOWING FRONTAL
BOUNDARY MEANDERING OVER SOUTH FLORIDA DURING THE PERIOD. STOUT
SOUTHWEST AND WESTERLY FLOW ALOFT ON TOP OF SHALLOW NORTHERLY FLOW
AT THE SURFACE WILL KEEP CLOUD COVER HIGH THROUGH SATURDAY. WEAK
UPGLIDE IN TANDEM WITH SHORTWAVE ENERGY MOVING OVERHEAD WILL ALLOW
FOR SOME LIGHT RAIN SHOWERS TO DEVELOP...WITH THE BEST CHANCE
ACROSS OUR SOUTHERN ZONES. KEPT RAIN CHANCES BETWEEN 20 AND 30
PERCENT FOR THE PERIOD...MAINLY GIVEN THE FACT THAT RAINFALL
TOTALS ARE EXPECTED TO BE LIGHT.
HIGH PRESSURE MOVING OFF THE MID ATLANTIC COAST LATE SATURDAY INTO
SUNDAY WILL TRANSITION OUR WINDS ONSHORE. FAIRLY TIGHT GRADIENT
WILL PRODUCE BREEZY TO WINDY CONDITIONS...ESPECIALLY ALONG THE
COAST.
SUN-WED...BOUNDARY WILL MOVE BACK NORTH AS A WARM FRONT LATE THIS
WEEKEND...ALLOWING TEMPS TO CLIMB AND CLOUD COVER TO GRADUALLY
DECREASE. TEMPERATURES ABOVE CLIMO EXPECTED MONDAY AND CONTINUING
INTO MID WEEK AS RIDGING DEVELOPS TO OUR EAST. WARM SOUTHERLY FLOW
WILL ALLOW TEMPERATURES TO WARM INTO THE 80S ACROSS MUCH OF THE
AREA...EXCEPT ALONG THE IMMEDIATE COASTLINE WHERE TEMPERATURES WILL
BE MODERATED BY THE CHILLY ATLANTIC.
&&
.AVIATION...
FAST MOVING PRE FRONTAL SQUALL LINE WILL TRAVERSE MOST OF THE
TERMINALS EARLY THIS MORNING. SOME STRONG WIND GUSTS 40-50 MPH ARE
POSSIBLE. KVRB-KSUA SHOULD SEE A CHANCE FOR SHOWERS/STORMS FROM
LATE MORNING INTO THE AFTERNOON. BEHIND THE LINE...OCCASIONAL MVFR
CEILINGS ARE EXPECTED TO LINGER THROUGH TONIGHT.
&&
.MARINE...
TODAY-TONIGHT...GUSTY SOUTHWEST WINDS CURRENTLY OCCURRING AHEAD OF
COLD FRONT AND PRODUCING HAZARDOUS BOATING. ADDITIONALLY...A FAST
MOVING SQUALL LINE WILL AFFECT THE WATERS FROM CANAVERAL NORTHWARD
THROUGH SUNRISE. SHOWERS AND SLIGHT CHANCE OF STORMS WILL OCCUR
SOUTHWARD THROUGH LATE MORNING AND AFTERNOON.
MARINERS SHOULD EXPECT SPECIAL MARINE WARNINGS EARLY THIS
MORNING...ESPECIALLY SEBASTIAN INLET NORTHWARD.
GUSTY WINDS WILL PERSIST OFFSHORE UNTIL ABOUT MIDDAY. THEN AS
FRONTAL TROUGH MOVES THROUGH...EXPECT WEST/NORTHWEST WINDS 10-15
KNOTS THIS AFTERNOON AND TURNING NORTHERLY THIS EVENING.
FRI-SUN...NORTHERLY WINDS ON FRIDAY WILL BEGIN TRANSITIONING TO THE
NORTHEAST FRIDAY NIGHT AS HIGH PRESSURE BUILDS ACROSS THE EASTERN
US. THE LOCAL PRESSURE GRADIENT WILL TIGHTEN ON SATURDAY...
INCREASING ONSHORE WINDS TO 20 TO 25 KNOTS WITH HIGHER GUSTS. POOR
BOATING CONDITIONS WILL RESULT WITH SEAS OFFSHORE EXPECTED TO
BUILD UP TO 8 TO 10 FEET BY EARLY SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 67 46 62 52 / 60 10 10 30
MCO 70 51 67 53 / 60 10 20 30
MLB 73 53 67 59 / 70 30 30 30
VRB 78 58 69 61 / 70 50 30 30
LEE 67 49 66 50 / 50 10 10 30
SFB 68 47 65 51 / 60 10 20 30
ORL 69 49 66 52 / 60 10 20 30
FPR 79 57 70 62 / 70 50 30 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM EST THIS MORNING FOR
FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 0-20 NM-
SEBASTIAN INLET TO JUPITER INLET 0-20 NM-VOLUSIA-BREVARD
COUNTY LINE TO SEBASTIAN INLET 0-20 NM.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE
20-60 NM- SEBASTIAN INLET TO JUPITER INLET 20-60 NM-VOLUSIA-
BREVARD COUNTY LINE TO SEBASTIAN INLET 20-60 NM.
&&
$$
SHORT TERM...LASCODY
LONG TERM....ULRICH
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1258 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE OVER NORTHERN FLORIDA THIS EVENING WILL TRACK
NORTHEASTWARD ALONG THE GEORGIA AND SOUTH CAROLINA COAST LATE
TONIGHT. COLD AND DRY HIGH PRESSURE WILL BUILD INTO THE AREA
FRIDAY AND SATURDAY. TEMPERATURES WILL REMAIN BELOW NORMAL.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WINTER STORM WARNING REMAINS IN EFFECT FOR PARTS OF THE NORTHERN
AND WESTERN FORECAST AREA.
PRECIPITATION HAS OVERSPREAD THE FORECAST AREA MAINLY ASSOCIATED
WITH ISENTROPIC LIFT...AND MOISTURE AND INSTABILITY AHEAD OF THE
MID-LEVEL SHORTWAVE TROUGH MOVING INTO THE AREA. THE MODELS
INDICATE THE GREATEST ISENTROPIC LIFT WILL OCCUR UNTIL AROUND 100
AM. SATELLITE TRENDS SUPPORT A PROGRESSIVE PATTERN. THE COLDEST
CLOUD TOPS INDICATING THE STRONGEST LIFT SHOULD SHIFT EAST OF THE
AREA BEFORE 100 AM.
THE LATEST OBSERVATIONS AND MODEL DATA INDICATE A MIX OF
RAIN...SLEET AND SNOW IN THE NORTH PART WHERE WE HAVE POSTED A
WINTER STORM WARNING. THE LATEST RAP HAS INDICATED A WARMING TREND
IN THE NORTH PART INDICATING PRECIPITATION MAY NOT BECOME ALL
SNOW. MOISTURE ALSO APPEARS TO BECOME SHALLOW AND BELOW THE SNOW
GROWTH AREA BEHIND THE MID-LEVEL SHORTWAVE TROUGH DURING THE
EARLY MORNING HOURS. THE MAIN PRECIPITATION TYPE MAY BECOME DRIZZLE
WITH FREEZING DRIZZLE POSSIBLE IN THE NORTH PART.
FARTHER SOUTH...THE LATEST RAP KEEPS THE LOWEST LAYERS ABOVE
FREEZING IN THE CSRA AND CENTRAL PART OVERNIGHT. THIS APPEARS ON
TRACK BASED ON OBSERVATION TRENDS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
THE SYSTEM RAPIDLY MOVES AWAY FROM THE REGION DURING THE DAY
THURSDAY. STILL PLENTY OF SHALLOW/LEVEL MOISTURE AROUND FOR
CLOUDS AND PERHAPS MORNING DRIZZLE. MODELS INDICATE UPPER LEVEL
ENERGY CROSSING THE REGION IN SOUTHWEST FLOW ALOFT. TEMPERATURES
WILL BE ABLE TO CLIMB BACK TO THE MIDDLE 40S ACROSS THE
SOUTH...WITH THE MIDDLE/UPPER 30S EXPECTED ACROSS THE NORTH WITH
SNOW COVER. LOWS IN THE MID 20S NORTH TO LOWER 30S SOUTH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LARGE COLD CANADIAN HIGH PRESSURE WILL BUILD EASTWARD FROM THE
CENTRAL MS RIVER VALLEY ON FRIDAY TO THE CENTRAL APPALACHIANS AND
OHIO VALLEY ON SATURDAY. DRY WEATHER WEATHER ALONG WITH BELOW NORMAL
TEMPERATURES EXPECT FRIDAY INTO SATURDAY WITH PWAT AT OR BELOW 0.50
INCHES. POSSIBLE WEDGE SET UP LATE IN THE WEEKEND WITH TROUGH/WEAK
LOW PRESSURE DEVELOPING ALONG THE SOUTH CAROLINA COAST. ISENTROPIC
LIFT AND INCREASING MOISTURE IS EXPECTED TO INCREASE SATURDAY NIGHT
INTO SUNDAY AS SURFACE HIGH PRESSURE MOVES OFF THE COAST AND A LOW
PRESSURE SYSTEM APPROACHES FROM THE WEST. CHANCE OF RAIN SUNDAY
THROUGH WEDNESDAY. SHOULD SEE WARMING TEMPERATURES MONDAY INTO
WEDNESDAY AS UPPER LEVEL RIDGE BUILDS OVER THE EASTERN CONUS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE IN RESTRICTIONS THROUGH THE TAF PERIOD.
RAIN CONTINUES TO CROSS THE TAF SITES ALONG WITH IFR...PATCHY
LIFR...CONDITIONS. LOW PRESSURE ALONG THE GA COAST WILL MOVE
NORTHWARD THROUGH THE TAF PERIOD WITH LOW LEVEL MOISTURE REMAINING
LINGERING. PRECIPITATION WILL REMAIN ALL RAIN THROUGH THE PERIOD
WITH RAIN DIMINISHING TO DRIZZLE DURING THE EARLY MORNING HOURS.
CIGS WILL IMPROVE TO MVFR AROUND 16Z WITH DRIZZLE COMING TO AN
END. WINDS WILL BE NORTHERLY AT 10 KNOTS OR LESS THROUGH
22Z...THEN DIMINISH TO LIGHT AND VARIABLE FOR THE REST OF THE
PERIOD.
EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN RESTRICTIONS
CONTINUING THROUGH FRIDAY AS A FRONTAL BOUNDARY REMAINS STALLED
ACROSS THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR SCZ015-
016-020>022.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
300 PM CST THU FEB 26 2015
.SHORT TERM...
THROUGH SATURDAY...
243 PM...LAKE EFFECT IS NOW ORGANIZING INTO A SINGLE BAND AS
WINDS TURN MORE NORTHWEST ACROSS NORTHEAST IL AND THIS BAND IS
SHIFTING TO THE SOUTHEAST AND WILL BE OUT OF COOK COUNTY IN THE
NEXT HOUR OR SO. WILL BE EXPIRING LAKE COUNTY IL FROM THE WARNING
AND FOR NOW WILL LET COOK COUNTY RIDE UNTIL 6 PM...BUT IF CURRENT
TRENDS CONTINUE...IT PROBABLY WILL BE CANCELLED EARLY.
HI RES GUIDANCE IS IN REASONABLE AGREEMENT THAT THE LAKE EFFECT
BAND WILL SHIFT INTO PORTER COUNTY BY EARLY/MID EVENING...SO
EXPECTED AMOUNTS IN NORTHERN LAKE COUNTY INDIANA ARE A BIT
UNCERTAIN BUT WITH RATES OF 1-2 INCHES PER HOUR IN THE BAND...ITS
POSSIBLE SOME ISOLATED AMOUNTS OF 3 TO 6 INCHES WILL BE POSSIBLE.
MORE CONFIDENCE WITH AMOUNTS INTO NORTHERN PORTER COUNTY AS THE
BAND REMAINS THERE FROM MID EVENING THROUGH THE OVERNIGHT HOURS
WITH LOCALLY 4 TO 7 INCHES...PERHAPS MOSTLY NEAR THE LAKE. THE
BAND THEN BEGINS TO SHIFT OUT OF THE LAKE TOWARD MORNING. SO NOT
PLANNING ANY CHANGES TO THE WARNING END TIME FOR EITHER LAKE OR
PORTER COUNTIES...THOUGH CONFIDENCE REGARDING WHEN EXACTLY PRECIP
ENDS IS A BIT UNCERTAIN.
HIGH PRESSURE BUILDS ACROSS THE MIDWEST TONIGHT AND THEN MOVES
ACROSS THE AREA ON FRIDAY. WINDS WILL SLOWLY DIMINISH OVERNIGHT
BUT LIKLELY REMAIN IN THE 5-10 MPH. THIS COMBINED WITH TEMPS
DROPPING WELL BELOW ZERO AWAY FROM CHICAGO WILL RESULT IN WINDS
CHILLS 20 BELOW TO 25 BELOW ZERO ACROSS THE NORTHERN CWA AND INTO
THE 15 BELOW RANGE SOUTH OF I-80. VALUES ARE BIT MARGINAL INTO
CHICAGO AND ALONG THE I-80 CORRIDOR BUT PLAN TO ISSUE A WIND
CHILL ADVISORY OVERNIGHT INTO FRIDAY MORNING GENERALLY ALONG AND
NORTH OF I-80 IN ILLINOIS.
DESPITE THE LIGHT WINDS AND SUNNY SKIES ON FRIDAY AS THE HIGH
SLOWLY MOVES ACROSS THE AREA...THE AIRMASS WILL REMAIN VERY COLD
WITH HIGHS ONLY REACHING THE MID TO PERHAPS UPPER TEENS. TEMPS
WILL LIKELY TANK FRIDAY NIGHT AS THE HIGH SHIFTS EAST AND LIGHT
WINDS TURN SOUTHERLY. SATURDAY WILL BE DRY AND A BIT WARMER WITH
HIGHS IN THE LOWER/MIDS 20S WITH INCREASING CLOUDS IN THE
AFTERNOON. CMS
&&
.LONG TERM...
SATURDAY NIGHT THROUGH THURSDAY...
THE TIME FRAME WILL START OUT ACTIVE AS A PERIOD OF ACCUMULATING
SNOW IS APPEARING LIKELY SATURDAY NIGHT INTO SUNDAY. STEADILY
INCREASING UPPER LEVEL FLOW OUT AHEAD OF DIGGING TROUGH TO THE
NORTH WILL ALLOW SHORT WAVE ENERGY TO TRAVERSE THE REGION DURING
THIS PERIOD...WHILE ONGOING WAA PERSISTS. THIS SHOULD ALLOW SNOW
TO SPREAD NORTHEAST ACROSS THE CWA DURING THE EVENING HOURS WITH
SNOW LIKELY ACROSS MUCH OF THE CWA AFTER THE MIDNIGHT TIME
FRAME...THEN LIKELY CONTINUING INTO SUNDAY AFTERNOON. MOST
GUIDANCE IN AGREEMENT WITH OVERALL LARGE SCALE SETUP DURING THIS
TIME AND EVEN WITH THIS SNOW SPREADING OVER THE CWA.
HOWEVER...THERE DOES APPEAR TO BE SOME TIMING DIFFERENCES OF THE
ONSET AND TIMING OF BEST SNOWFALL. SO I DO FEEL IT WILL SNOW AND
HAVE LIKELY POPS OVER THE ENTIRE CWA LATE SATURDAY NIGHT INTO
SUNDAY MORNING...BUT DID NOT GO TO CATEGORICAL BASED ON THE
PREVIOUSLY MENTIONED UNCERTAINTIES. ONLY MINOR CHANGES MADE TO THE
CURRENT SNOW FORECAST WITH THE BEST FORCING AND HIGHEST SNOWFALL
TOTALS CURRENTLY EXPECTED TO BE SOUTH OF I80. WHILE MOST OF THE
CWA WILL LIKELY OBSERVE ACCUMULATING SNOWFALL...THE SOUTHERN CWA
COULD APPROACH ADVISORY TYPE SNOW. HOWEVER I WONDER IF MY CURRENT
TOTAL MIGHT BE A LITTLE TOO HIGH...ESPECIALLY WITH THE ANTICIPATED
DRIVING MECHANISMS OF THIS SNOW...BUT THE LONGER DURATION OF THIS
LIGHT TO AT TIME MODERATE SNOW COULD HELP FOR THE CURRENT FORECAST
TOTALS. SYSTEM SNOW WILL DEPART TO THE EAST LATE SUNDAY AND SUNDAY
EVENING...AS HIGH PRESSURE BUILDS ACROSS THE REGION.
EARLY NEXT WEEK APPEARS TO BEGIN QUIET...BUT WITH ACTIVE WEATHER
RETURNING THROUGH MIDWEEK. HIGHLY AMPLIFIED PATTERN WITH UPPER
LEVEL RIDGE OVER THE EASTERN US AND A DIGGING TROUGH OVER THE
WESTERN CONUS WILL BE IN PLACE ON TUESDAY...AS DEEPENING SURFACE
LOW APPROACHES THE CWA FROM THE SOUTHWEST. STRONG WARM AIR AND
MOIST ADVECTION IS ANTICIPATED MONDAY NIGHT AND ESPECIALLY
TUESDAY/TUESDAY NIGHT. THIS WILL NOT ONLY PROVIDE THE POTENTIAL
FOR INITIAL VARYING PRECIP TYPE BUT WITH ALSO STEADIER
RAINFALL...AS A BROAD AREA OF PRECIP IS EXPECTED TO ACCOMPANY THIS
SYSTEM. EC AND GFS SIMILAR WITH REGARDS TO WAA...BUT WITH THE GFS
NOT AS ROBUST WITH THE MOISTURE ADVECTION AS THE EC IS APPEARING
TO BE. IF THE EC WERE TO VERIFY...THEN SURFACE DEWPOINTS COULD
APPROACH 50 DEG AND 850MB DEWPOINTS APPROACHING 10-11C. THIS WILL
BE CONCERNING FOR POSSIBLE HYDRO ISSUES...ESPECIALLY WITH THE
ANTICIPATED SNOW THIS WEEKEND. THERMAL PROFILES SUPPORTIVE OF ALL
RAIN ON TUESDAY AND ALTHOUGH I HAVENT INCLUDED THUNDER IN THE
GRIDS AT THIS TIME...WILL NEED TO MONITOR THIS POTENTIAL AS
WELL...ESPECIALLY FOR THE SOUTHERN CWA.
RODRIGUEZ
&&
.CLIMATE...
345 AM CST
TEMPERATURES ARE FORECAST ONCE AGAIN TO BE CLOSE OR BREAK THE
FOLLOWING RECORDS THROUGH THE LATTER HALF OF THIS WEEK...INCLUDING
ONE ON FRIDAY IN ROCKFORD THAT WAS SET JUST LAST WINTER:
ROCKFORD...
TODAY FEB 26TH LOW MAXIMUM: 11 IN 1920
FRIDAY FEB 27TH LOW MAXIMUM: 15 IN 2014
SATURDAY FEB 28TH LOW: -7 IN 1962
SATURDAY FEB 28TH LOW MAXIMUM: 17 IN 1962
CHICAGO...
FRIDAY FEB 27TH LOW: -6 IN 1897
SATURDAY FEB 28TH LOW: 0 IN 1884
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NORTHERLY WINDS 10 TO 14 KT BECOING NORTHWEST THIS EVENING.
KJB
//DISCUSSION...UPDATED 18Z...
THE FOCUS FOR LAKE EFFECT SNOW SHOWERS WILL GRADUALLY BEGIN TO SHIFT
EASTWARD INTO SOUTHERN COOK AND NORTHWESTERN INDIANA OVER THE NEXT
FEW HOURS. AREA SURFACE OBSERVATIONS INDICATE WINDS SHIFTING
NORTHERLY ACROSS LAKE AND NORTHERN COOK COUNTIES IN ILLINOIS. RADAR
TRENDS OVER THE PAST HOUR HAVE ALSO SHOWN A DECREASE IN INTENSITIES
ACROSS LAKE COUNTY ILLINOIS...WITH SEVERAL SITES NOW OUT OF THE SNOW
AREA. THESE SAME TRENDS SHOULD GRADUALLY SHIFT SOUTH AND EASTWARD
THROUGH THE AFTERNOON. A BETTER WELL DEVELOPED BAND OF LAKE EFFECT
SNOW SHOWERS WILL TRY TO MOVE OVER KMDW OVER THE NEXT HOUR OR
SO...AND THIS COULD RESULT IN ANOTHER BRIEF PERIOD OF LOW
VISIBILITIES...POSSIBLY DOWN TO A HALF MILE. CONDITIONS WILL
IMPROVE BY MID AFTERNOON AT KMDW...BUT AT KGYY PERIODS OF LAKE
EFFECT SNOW SHOWERS WILL CONTINUE THROUGH THE AFTERNOON...BEFORE
ABATING THIS EVENING.
AFTER THIS LAKE EFFECT FOCUS SHIFTS EAST OF THE TERMINALS A PERIOD
OF QUIET WEATHER IS EXPECTED FOR TONIGHT AND FRIDAY AS A SURFACE
RIDGE OF HIGH PRESSURE MOVES OVER CENTRAL ILLINOIS. WINDS ARE
EXPECTED TO BE RATHER LIGHT WITH A WESTERLY DIRECTION.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
HIGH WITH ALL ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. SOUTHWEST WINDS.
SATURDAY...VFR THEN SNOW WITH IFR PROBABLE SATURDAY NIGHT. SOUTH
WINDS.
SUNDAY...SNOW WITH IFR POSSIBLE. SOUTHWEST WINDS.
MONDAY...VFR THEN LIGHT SNOW WITH IFR POSSIBLE MONDAY NIGHT. NORTH
WINDS.
TUESDAY...WINTRY MIX LIKELY WITH IFR. SOUTHWEST WINDS.
WEDNESDAY...SLIGHT CHANCE OF SNOW AND IFR. NORTHWEST WINDS.
MTF
&&
.MARINE...
215 PM CST
THE FAR NORTHERN PORTIONS OF THE LAKE REMAINS ICE COVERED AS DO
THE SOUTHERN NEARSHORE WATERS. THERE...WAVES HAVE REMOVED FROM THE
FORECAST FOR THESE AREAS.
HIGH PRESSURE EXTENDS FROM THE NORTHERN PLAINS...WITH A CENTRAL
PRESSURE OF 30.8 INCHES...SOUTH THROUGH TEXAS AND EAST ACROSS THE
GREAT LAKES. THE CENTER OF THE HIGH WILL CONTINUE TO DROP TO THE
SOUTHEAST...TO THE UPPER MISSOURI VALLEY BY FRIDAY MORNING. WITH
RIDGE AXIS EXTENDING ACROSS LAKE MICHIGAN...A CONVERGENCE BAND HAS
SET UP WITH A PLUME OF LAKE EFFECT SNOW MOVING ACROSS THE SOUTHERN
PORTIONS OF THE LAKE. AS THE CENTER OF THE HIGH CONTINUES TO
SETTLE INTO THE OHIO VALLEY FRIDAY AND FRIDAY NIGHT...WINDS OVER
THE LAKE WILL BACK FROM NORTHERLY TO WESTERLY FRIDAY NIGHT AND
SATURDAY. AS THE HIGH MOVES OFF TO THE EAST...A WEAK COLD FRONT IS
EXPECTED TO CROSS THE UPPER MISSISSIPPI VALLEY SATURDAY
NIGHT...BACKING WINDS OVER THE LAKE TO SOUTHWESTERLY. THROUGH THIS
PERIOD...WINDS WILL BE ON A GENERAL WEAKENING TREND. THE WEAK COLD
FRONT IS EXPECTED TO SWEEP ACROSS THE LAKE SUNDAY EVENING WITH
ANOTHER ARCTIC HIGH QUICKLY FOLLOWING IN IT`S WAKE. THIS HIGH WILL
TAKE A MORE NORTHERLY TRACK...WITH THE CENTER OF THE HIGH CROSSING
THE LAKE SUNDAY NIGHT AND MONDAY...LEADING TO A SHORT PERIOD OF
LIGHT AND VARIABLE WINDS. THE HIGH SHOULD THEN PUSH EAST OF THE
LAKE MONDAY AND MONDAY NIGHT AS LOW PRESSURE DEVELOPS OVER
KANSAS/NEBRASKA IN THE LEE OF THE ROCKIES...SETTING UP A PERIOD OF
SOUTHEAST WINDS AS AN ASSOCIATED WARM FRONT EXTENDS EAST OF THE
LOW...TO THE OHIO VALLEY. THE LOW IS EXPECTED TO DEEPEN TO 29.1
INCHES AS IT TRACKS NORTHEAST AND CROSSES THE MIDDLE OF LAKE
MICHIGAN TUESDAY EVENING.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...LAKE EFFECT SNOW WARNING...ILZ014 UNTIL 6 PM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022...2
AM FRIDAY TO 9 AM FRIDAY.
LAKE EFFECT SNOW WARNING...ILZ006 UNTIL 3 PM THURSDAY.
IN...LAKE EFFECT SNOW WARNING...INZ001 UNTIL 9 PM THURSDAY.
LAKE EFFECT SNOW WARNING...INZ002 UNTIL 6 AM FRIDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
249 PM CST Thu Feb 26 2015
.SHORT TERM...(Tonight)
ISSUED AT 249 PM CST THU FEB 26 2015
Will issue a wind chill advisory for areas along and north of a
Jacksonville to Springfield to Decatur to Paris line overnight into
mid Fri morning for wind chills of 15-24F below zero with the
coldest wind chills in Knox and Stark counties around dawn Friday.
Wind chills reach near or below 15F below near Galesburg around
midnight, and se toward I-72 later tonight. Lows overnight to
range from 5-10F below zero from the IL river valley nw to zero to
5F above in southeast IL from I-70 se. Broken to overcast low
clouds still cover much of IL with some clearing far west central
and northern IL near WI border. Still getting scattered light snow
showers and areas of flurries over central IL (visibilities as low as
2-5 miles) due to lingering moisture off lake MI along with a short
wave dropping se into the area. HRRR may be a bit too progressive in
clearing low clouds from north to south during early and mid
evening. Low clouds to likely decrease over IL river valley early
this evening, but thinking it may take until overnight for
decreasing of low clouds in southeast IL since short wave still
affecting southern counties tonight. Also lingered chance of
flurries from I-55 east late this afternoon and early evening and
into mid evening in southeast IL. Strong 1042 mb arctic high
pressure near the MT/ND and southern Saskatchewan border and ridging
SSE into the Great Plains to settle se into IA/MO by Friday morning
bringing dry weather and bitter cold temperatures overnight into Fri
morning. North winds 10-17 mph and gusts 18-24 mph this afternoon
will veer nw and decrease to 5-10 mph overnight.
&&
.LONG TERM...(Friday through Thursday)
ISSUED AT 249 PM CST THU FEB 26 2015
Morning upper air and satellite imagery depicts trough over the
central plains with clipper shortwave moving over IL, producing
continued light snow in strong 850mb cold air advection. Wave
continuing to move east and will break up in afternoon.
Ridge of high pressure to build in overnight, again producing wind
chills. Ridge to move off to the east through Friday and into
Saturday. By Saturday afternoon, overrunning from the next system
begins to develop into plains. NAM model brings snow into western IL
and feel not unreasonable. Will therefore add slight chc pops Sat
afternoon, with main pcpn Sat night to Sunday.
Models similar in development of frontal zone from western plains
low into Ozarks, with significant lift over boundary Saturday night.
This will push snow formation into central IL Saturday night,
continuing into Sunday. Main lift is Saturday night as upper wave
moves across great lakes, with pcpn lingering into Sunday. Diminshed
the pcpn Sun night as high pressure builds in.
Upper flow changes Monday to Tuesday, with pcpn again developing
into Monday night to Tuesday as surface low center develops in
plains and moves northeast, west of cwa though. The result is that
with this feature, area stays in the warm section and so pcpn starts
as freezing rain and changes to rain. Still uncertainty though, as
the operational models are very different on the timing of the
system movement. made few changes due to these differences.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1159 AM CST THU FEB 26 2015
Light snow mainly se of the IL river at midday to gradually
diminish to scattered flurries during the afternoon. Carried vsbys
1.5-3 miles from I-55 se until mid afternoon and then mainly VFR
vsbys thereafter with flurries. MVFR ceilings to lift to low end
VFR ceilings during mid/late afternoon and then scatter out from
nw to se during mid/late evening. Another upper level short wave
to pass through IL later today and then clearing to come in behind
this feature by overnight. North winds 10-17 kts this afternoon to
veer NW and diminish to 4-8 kts by overnight and Friday morning as
1043 mb arctic high pressure over southern Sasketchewan settles
into IA/MO/IL by 18Z/noon Friday bringing fair wx and lighter winds.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY from Midnight tonight to 10 AM CST Friday
FOR ILZ027>031-036>038-040>051-053-055-057.
&&
$$
SHORT TERM...07
LONG TERM...Goetsch
AVIATION...07
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1026 AM MST THU FEB 26 2015
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 254 AM MST THU FEB 26 2015
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW BROAD
MEAN TROUGH ACROSS THE CONUS..WITH SHARP N-NW FLOW EXPECTING
ACROSS THE CENTRAL ROCKIES AND NORTHERN PLAINS. AT THE SURFACE
1042 SURFACE HIGH PRESSURE IS EXPECTING FROM THE CANADIAN/US
BORDER WITH ITS INFLUENCE EXTENDING SOUTH OVER OUR CWA AND
TOWARDS THE SOUTHERN PLAINS. RADAR SHOWS LIGHT SNOW TRANSITIONING
ALONG THE PALMER DIVIDE AND ACROSS THE SOUTHEAST PLAINS OF
COLORADO...WITH THE NORTHEAST EXTENT OVER OUR FAR SOUTHWESTERN
CWA.
GUIDANCE CONTINUES TO SHOW POTENTIAL FOR LIGHT SNOW ACROSS THE
WEST AND SOUTHWEST PARTS OF THE CWA THROUGH MOST OF THE DAY. THIS
APPEARS TO BE DRIVEN MOSTLY BY WEAK FRONTOGENETIC FORCING AND
OVERRUNNING OVER THE SHALLOW ARCTIC AIR MASS IN PLACE. ANY
SNOWFALL THIS MORNING THOUGH THE AFTERNOON APPEARS TO BE VERY
LIGHT AS DEEP MOISTURE AND LARGE SCALE FORCING DO NOT APPEAR TO BE
IN PLACE OVER OUR CWA. BY LATE AFTERNOON/EVENING A QUICK MOVING
SHORT WAVE TROUGH WILL DROP SOUTH OVER THE CWA WITH SOUNDINGS
SHOWING DEEP SATURATION WITHIN THE DENDRITIC LAYER OCCURRING BY
LATE TONIGHT- EARLY FRIDAY MORNING OVER THE SOUTHERN HALF OF OUR
CWA. BETTER SIGNAL APPEARS TO BE ALONG/SOUTH OF HIGHWAY 24 WHERE
1-2" OF SNOW IS CURRENTLY FORECAST. WHILE I CANT RULE OUT 3" TOTAL
SNOWFALL FROM THIS AFTERNOON THROUGH FRIDAY MORNING IN OUR FAR
SOUTH...CONFIDENCE IS TOO LOW FOR ADVISORY ISSUANCE.
WINDS WILL BEGIN TO INCREASE ON THE BACK SIDE OF THIS SHORTWAVE
IN THE 12-15Z TIME PERIOD FROM THE WEST TO EAST WITH DAYTIME GUSTS
FRIDAY AROUND 30 MPH. IMPACT COULD BE A BRIEF WINDOW FOR WIND
CHILLS EARLY FRIDAY MORNING NEAR OR BELOW ADVISORY CRITERIA. WHILE
THE AIR MASS IS CERTAINLY COLD ENOUGH TO RAISE THE POTENTIAL FOR
-15F WIND CHILLS...HOWEVER WE MAY NOT SEE IDEAL CONDITIONS FOR
RADIATIONAL COOLING OVER MOST OF THE CWA. INCREASING THICK CLOUD
COVER/POSSIBLE PRECIPITATION COULD LIMIT OVERNIGHT COOLING AND
LOWERS CONFIDENCE. CURRENT FORECAST SHOWS WIND CHILLS JUST
OUTSIDE CRITERIA...WITH LOWEST VALUES IN A 2-3HR WINDOW AROUND 12Z
FRIDAY MORNING.
TROUGH BEGINS TO AMPLIFY ACROSS THE WESTERN US ALLOWING H3 JET TO
SHIFT NORTH AND STRONGER FORCING TO BUILD NORTH OVER OUR CWA BY
LATE FRIDAY NIGHT INTO SATURDAY/SATURDAY NIGHT ALONG WITH
INCREASING MOISTURE ADVECTION INTO OUR SOUTHERN AND EASTERN CWA.
STRONGEST PRECIP SIGNAL IS IN OUR EAST AND SOUTHEAST CWA...WHERE
CURRENT MODEL CONSENSUS SHOWS POSSIBILITY OF 3" SNOW FALL
(ROUGHLY ALONG/EAST OF HIGHWAY 83). WILL NEED TO MONITOR THIS AS
THIS COULD BE OUR BEST CHANCE TO REACH ADVISORY CRITERIA FOR
SNOWFALL IN THE NEXT 7 DAYS.
REGARDING TEMPS THROUGH THE PERIOD...ARCTIC AIR MASS WILL BE IN
PLACE WITH ONLY SLIGHT MODERATION OCCURRING SATURDAY AHEAD OF
AMPLIFYING TROUGH. RESULT WILL BE BELOW NORMAL TEMPERATURES...WITH
DAYTIME/NIGHT TIME MAX/MINS DEPENDENT ON CLOUD COVERS INFLUENCE
ON MIXING. I TRENDED DAYTIME TEMPS BACK A LITTLE AND BUMPED
OVERNIGHT TEMPS UP (MAINLY TONIGHT) CONSIDERING ONGOING FORECAST
FOR PERSISTENT/THICK CLOUD COVER. OVERALL TEMPERATURES TRENDS
HAVE CHANGED LITTLE FROM PREVIOUS FORECAST.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 254 AM MST THU FEB 26 2015
AN UPPER TROUGH SWINGS THROUGH THE NORTHERN PLAINS DURING THE DAY ON
SUNDAY JUST TO THE NORTH OF THE FORECAST AREA WHILE THE SOUTHERN
BRANCH OF THE UPPER FLOW REMAINS IN PLACE EXTENDING FROM THE FAR
SOUTHWEST U.S. TO THE MID MISSISSIPPI VALLEY REGION. THE UPPER LOW
CENTER THAT HAS BEEN TRAVELING SOUTH ALONG THE WEST COAST IS KICKED
EAST AS AN OPEN WAVE OVER THE SOUTHWEST U.S. AHEAD OF A LOW PRESSURE
AREA DIVING INTO THE PACIFIC NORTHWEST WITH A STRONG JET PUSHING
SOUTH ALONG THE WEST COAST. THIS SHOULD RESULT IN AN ACTIVE WEATHER
PATTERN ACROSS THE CENTRAL HIGH PLAINS REGION THROUGH THE MIDDLE OF
NEXT WEEK AS A NUMBER OF SHORT WAVE TROUGHS LIFTING OUT OF THE MAIN
TROUGH TRANSITION THE REGION IN ADVANCE OF THE MAIN UPPER TROUGH
THAT EVENTUALLY MOVES EAST OF THE ROCKIES ON WEDNESDAY NIGHT/EARLY
THURSDAY.
EXPECT THE PRIMARY SURFACE FRONTAL ZONE TO BE PUSHED UP ALONG THE
ROCKIES AND EXTENDING EAST ACROSS MAINLY THE SOUTHERN HIGH PLAINS
WITH THE OCCASIONAL PUSH NORTH INTO THE FORECAST AREA. HAVE KEPT
TEMPERATURES COLDER THAN AVERAGE THROUGH THE EXTENDED PERIOD AS A
RESULT WITH HIGHS MAINLY IN THE 20S AND 30S AND LOWS IN THE SINGLE
DIGITS TO TEENS. HAVE ALSO BROAD BRUSHED AREAS OF SLIGHT CHANCE TO
CHANCE POPS STRETCHING ACROSS THE FORECAST AREA EACH PERIOD FROM
SUNDAY THROUGH WEDNESDAY NIGHT AS A RESULT OF THE FRONTAL ZONE BEING
IN THE VICINITY WITH THE SHORT WAVE IMPULSES ALSO STREAMING ACROSS
THE AREA. DO NOT EXPECT ANY SIGNIFICANT SNOWFALL AMOUNTS AT THIS
TIME. CONFIDENCE IS VERY LOW IN THE TIMING AND SPECIFIC SNOWFALL
AMOUNTS OVER SPECIFIC LOCATIONS SINCE EVEN SMALL SMALL DIFFERENCES
IS THE POSITION OF FEATURES COULD RESULT IN LARGE DIFFERENCES IS
THE PROBABILITIES OF RECEIVING PRECIPITATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1022 AM MST THU FEB 26 2015
AT KGLD...VFR EXPECTED THROUGH THE AFTERNOON AND EARLY EVENING
HOURS ALTHOUGH MID LEVEL DECK WILL GRADUALLY THICKEN.
TONIGHT...LIGHT SNOW WILL SPREAD OUT OF EASTERN COLORADO WITH
CEILING AND VISIBILITY RESTRICTIONS LIKELY AFTER MIDNIGHT AND
CONTINUING THROUGH FRIDAY MORNING. LIFR POSSIBLE FRIDAY MORNING
WITH 1/2SM VISIBILITIES IN LIGHT TO MODERATE SNOW.
AT KMCK...VFR EXPECTED THROUGH THE PERIOD. SNOW WILL LIKELY STAY
SOUTH OF KMCK...ALTHOUGH CLOUDS WILL INCREASE AND MAY APPROACH
MVFR CEILINGS AT TIMES LATE TONIGHT AND FRIDAY MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JSL
AVIATION...024
AREA FORECAST DISCUSSION
NWS GOODLAND KS
421 AM MST THU FEB 26 2015
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 254 AM MST THU FEB 26 2015
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW BROAD
MEAN TROUGH ACROSS THE CONUS..WITH SHARP N-NW FLOW EXPECTING
ACROSS THE CENTRAL ROCKIES AND NORTHERN PLAINS. AT THE SURFACE
1042 SURFACE HIGH PRESSURE IS EXPECTING FROM THE CANADIAN/US
BORDER WITH ITS INFLUENCE EXTENDING SOUTH OVER OUR CWA AND
TOWARDS THE SOUTHERN PLAINS. RADAR SHOWS LIGHT SNOW TRANSITIONING
ALONG THE PALMER DIVIDE AND ACROSS THE SOUTHEAST PLAINS OF
COLORADO...WITH THE NORTHEAST EXTENT OVER OUR FAR SOUTHWESTERN
CWA.
GUIDANCE CONTINUES TO SHOW POTENTIAL FOR LIGHT SNOW ACROSS THE
WEST AND SOUTHWEST PARTS OF THE CWA THROUGH MOST OF THE DAY. THIS
APPEARS TO BE DRIVEN MOSTLY BY WEAK FRONTOGENETIC FORCING AND
OVERRUNNING OVER THE SHALLOW ARCTIC AIR MASS IN PLACE. ANY
SNOWFALL THIS MORNING THOUGH THE AFTERNOON APPEARS TO BE VERY
LIGHT AS DEEP MOISTURE AND LARGE SCALE FORCING DO NOT APPEAR TO BE
IN PLACE OVER OUR CWA. BY LATE AFTERNOON/EVENING A QUICK MOVING
SHORT WAVE TROUGH WILL DROP SOUTH OVER THE CWA WITH SOUNDINGS
SHOWING DEEP SATURATION WITHIN THE DENDRITIC LAYER OCCURRING BY
LATE TONIGHT- EARLY FRIDAY MORNING OVER THE SOUTHERN HALF OF OUR
CWA. BETTER SIGNAL APPEARS TO BE ALONG/SOUTH OF HIGHWAY 24 WHERE
1-2" OF SNOW IS CURRENTLY FORECAST. WHILE I CANT RULE OUT 3" TOTAL
SNOWFALL FROM THIS AFTERNOON THROUGH FRIDAY MORNING IN OUR FAR
SOUTH...CONFIDENCE IS TOO LOW FOR ADVISORY ISSUANCE.
WINDS WILL BEGIN TO INCREASE ON THE BACK SIDE OF THIS SHORTWAVE
IN THE 12-15Z TIME PERIOD FROM THE WEST TO EAST WITH DAYTIME GUSTS
FRIDAY AROUND 30 MPH. IMPACT COULD BE A BRIEF WINDOW FOR WIND
CHILLS EARLY FRIDAY MORNING NEAR OR BELOW ADVISORY CRITERIA. WHILE
THE AIR MASS IS CERTAINLY COLD ENOUGH TO RAISE THE POTENTIAL FOR
-15F WIND CHILLS...HOWEVER WE MAY NOT SEE IDEAL CONDITIONS FOR
RADIATIONAL COOLING OVER MOST OF THE CWA. INCREASING THICK CLOUD
COVER/POSSIBLE PRECIPITATION COULD LIMIT OVERNIGHT COOLING AND
LOWERS CONFIDENCE. CURRENT FORECAST SHOWS WIND CHILLS JUST
OUTSIDE CRITERIA...WITH LOWEST VALUES IN A 2-3HR WINDOW AROUND 12Z
FRIDAY MORNING.
TROUGH BEGINS TO AMPLIFY ACROSS THE WESTERN US ALLOWING H3 JET TO
SHIFT NORTH AND STRONGER FORCING TO BUILD NORTH OVER OUR CWA BY
LATE FRIDAY NIGHT INTO SATURDAY/SATURDAY NIGHT ALONG WITH
INCREASING MOISTURE ADVECTION INTO OUR SOUTHERN AND EASTERN CWA.
STRONGEST PRECIP SIGNAL IS IN OUR EAST AND SOUTHEAST CWA...WHERE
CURRENT MODEL CONSENSUS SHOWS POSSIBILITY OF 3" SNOW FALL
(ROUGHLY ALONG/EAST OF HIGHWAY 83). WILL NEED TO MONITOR THIS AS
THIS COULD BE OUR BEST CHANCE TO REACH ADVISORY CRITERIA FOR
SNOWFALL IN THE NEXT 7 DAYS.
REGARDING TEMPS THROUGH THE PERIOD...ARCTIC AIR MASS WILL BE IN
PLACE WITH ONLY SLIGHT MODERATION OCCURRING SATURDAY AHEAD OF
AMPLIFYING TROUGH. RESULT WILL BE BELOW NORMAL TEMPERATURES...WITH
DAYTIME/NIGHT TIME MAX/MINS DEPENDENT ON CLOUD COVERS INFLUENCE
ON MIXING. I TRENDED DAYTIME TEMPS BACK A LITTLE AND BUMPED
OVERNIGHT TEMPS UP (MAINLY TONIGHT) CONSIDERING ONGOING FORECAST
FOR PERSISTENT/THICK CLOUD COVER. OVERALL TEMPERATURES TRENDS
HAVE CHANGED LITTLE FROM PREVIOUS FORECAST.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 254 AM MST THU FEB 26 2015
AN UPPER TROUGH SWINGS THROUGH THE NORTHERN PLAINS DURING THE DAY ON
SUNDAY JUST TO THE NORTH OF THE FORECAST AREA WHILE THE SOUTHERN
BRANCH OF THE UPPER FLOW REMAINS IN PLACE EXTENDING FROM THE FAR
SOUTHWEST U.S. TO THE MID MISSISSIPPI VALLEY REGION. THE UPPER LOW
CENTER THAT HAS BEEN TRAVELING SOUTH ALONG THE WEST COAST IS KICKED
EAST AS AN OPEN WAVE OVER THE SOUTHWEST U.S. AHEAD OF A LOW PRESSURE
AREA DIVING INTO THE PACIFIC NORTHWEST WITH A STRONG JET PUSHING
SOUTH ALONG THE WEST COAST. THIS SHOULD RESULT IN AN ACTIVE WEATHER
PATTERN ACROSS THE CENTRAL HIGH PLAINS REGION THROUGH THE MIDDLE OF
NEXT WEEK AS A NUMBER OF SHORT WAVE TROUGHS LIFTING OUT OF THE MAIN
TROUGH TRANSITION THE REGION IN ADVANCE OF THE MAIN UPPER TROUGH
THAT EVENTUALLY MOVES EAST OF THE ROCKIES ON WEDNESDAY NIGHT/EARLY
THURSDAY.
EXPECT THE PRIMARY SURFACE FRONTAL ZONE TO BE PUSHED UP ALONG THE
ROCKIES AND EXTENDING EAST ACROSS MAINLY THE SOUTHERN HIGH PLAINS
WITH THE OCCASIONAL PUSH NORTH INTO THE FORECAST AREA. HAVE KEPT
TEMPERATURES COLDER THAN AVERAGE THROUGH THE EXTENDED PERIOD AS A
RESULT WITH HIGHS MAINLY IN THE 20S AND 30S AND LOWS IN THE SINGLE
DIGITS TO TEENS. HAVE ALSO BROAD BRUSHED AREAS OF SLIGHT CHANCE TO
CHANCE POPS STRETCHING ACROSS THE FORECAST AREA EACH PERIOD FROM
SUNDAY THROUGH WEDNESDAY NIGHT AS A RESULT OF THE FRONTAL ZONE BEING
IN THE VICINITY WITH THE SHORT WAVE IMPULSES ALSO STREAMING ACROSS
THE AREA. DO NOT EXPECT ANY SIGNIFICANT SNOWFALL AMOUNTS AT THIS
TIME. CONFIDENCE IS VERY LOW IN THE TIMING AND SPECIFIC SNOWFALL
AMOUNTS OVER SPECIFIC LOCATIONS SINCE EVEN SMALL SMALL DIFFERENCES
IS THE POSITION OF FEATURES COULD RESULT IN LARGE DIFFERENCES IS
THE PROBABILITIES OF RECEIVING PRECIPITATION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 421 AM MST THU FEB 26 2015
2000-3000 KFT AGL CIGS WILL CONTINUE TO BE POSSIBLE AT KGLD EARLY
THIS MORNING...THOUGH VFR SHOULD PREVAIL. LIGHT SNOW WILL BEGIN
TO SPREAD NORTH AND BY LATE THIS AFTERNOON OUT OF EASTERN COLORADO
INTO NORTHWEST KANSAS. QUESTION IS WHETHER IT WILL IMPACT EITHER
TERMINAL...AND AT THIS POINT CONFIDENCE IS TOO LOW TO ADD MENTION
AT ANY POINT IN THE TAF PERIOD. THERE IS A BETTER CHANCE FOR SNOW
AT KGLD AFTER 06Z...BUT WILL NOT INCLUDE AS GUIDANCE IS STILL
SHOWING THE STRONGEST SIGNAL SOUTH. MVFR CIGS WILL LIKELY
REDEVELOP OVER THE KGLD TERMINAL LATE TONIGHT WITH INCREASING
MOISTURE. WINDS WILL SHIFT FROM THE NORTH TO THE SOUTHEAST THROUGH
THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JSL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
255 AM MST THU FEB 26 2015
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 254 AM MST THU FEB 26 2015
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW BROAD
MEAN TROUGH ACROSS THE CONUS..WITH SHARP N-NW FLOW EXPECTING
ACROSS THE CENTRAL ROCKIES AND NORTHERN PLAINS. AT THE SURFACE
1042 SURFACE HIGH PRESSURE IS EXPECTING FROM THE CANADIAN/US
BORDER WITH ITS INFLUENCE EXTENDING SOUTH OVER OUR CWA AND
TOWARDS THE SOUTHERN PLAINS. RADAR SHOWS LIGHT SNOW TRANSITIONING
ALONG THE PALMER DIVIDE AND ACROSS THE SOUTHEAST PLAINS OF
COLORADO...WITH THE NORTHEAST EXTENT OVER OUR FAR SOUTHWESTERN
CWA.
GUIDANCE CONTINUES TO SHOW POTENTIAL FOR LIGHT SNOW ACROSS THE
WEST AND SOUTHWEST PARTS OF THE CWA THROUGH MOST OF THE DAY. THIS
APPEARS TO BE DRIVEN MOSTLY BY WEAK FRONTOGENETIC FORCING AND
OVERRUNNING OVER THE SHALLOW ARCTIC AIR MASS IN PLACE. ANY
SNOWFALL THIS MORNING THOUGH THE AFTERNOON APPEARS TO BE VERY
LIGHT AS DEEP MOISTURE AND LARGE SCALE FORCING DO NOT APPEAR TO BE
IN PLACE OVER OUR CWA. BY LATE AFTERNOON/EVENING A QUICK MOVING
SHORT WAVE TROUGH WILL DROP SOUTH OVER THE CWA WITH SOUNDINGS
SHOWING DEEP SATURATION WITHIN THE DENDRITIC LAYER OCCURRING BY
LATE TONIGHT- EARLY FRIDAY MORNING OVER THE SOUTHERN HALF OF OUR
CWA. BETTER SIGNAL APPEARS TO BE ALONG/SOUTH OF HIGHWAY 24 WHERE
1-2" OF SNOW IS CURRENTLY FORECAST. WHILE I CANT RULE OUT 3" TOTAL
SNOWFALL FROM THIS AFTERNOON THROUGH FRIDAY MORNING IN OUR FAR
SOUTH...CONFIDENCE IS TOO LOW FOR ADVISORY ISSUANCE.
WINDS WILL BEGIN TO INCREASE ON THE BACK SIDE OF THIS SHORTWAVE
IN THE 12-15Z TIME PERIOD FROM THE WEST TO EAST WITH DAYTIME GUSTS
FRIDAY AROUND 30 MPH. IMPACT COULD BE A BRIEF WINDOW FOR WIND
CHILLS EARLY FRIDAY MORNING NEAR OR BELOW ADVISORY CRITERIA. WHILE
THE AIR MASS IS CERTAINLY COLD ENOUGH TO RAISE THE POTENTIAL FOR
-15F WIND CHILLS...HOWEVER WE MAY NOT SEE IDEAL CONDITIONS FOR
RADIATIONAL COOLING OVER MOST OF THE CWA. INCREASING THICK CLOUD
COVER/POSSIBLE PRECIPITATION COULD LIMIT OVERNIGHT COOLING AND
LOWERS CONFIDENCE. CURRENT FORECAST SHOWS WIND CHILLS JUST
OUTSIDE CRITERIA...WITH LOWEST VALUES IN A 2-3HR WINDOW AROUND 12Z
FRIDAY MORNING.
TROUGH BEGINS TO AMPLIFY ACROSS THE WESTERN US ALLOWING H3 JET TO
SHIFT NORTH AND STRONGER FORCING TO BUILD NORTH OVER OUR CWA BY
LATE FRIDAY NIGHT INTO SATURDAY/SATURDAY NIGHT ALONG WITH
INCREASING MOISTURE ADVECTION INTO OUR SOUTHERN AND EASTERN CWA.
STRONGEST PRECIP SIGNAL IS IN OUR EAST AND SOUTHEAST CWA...WHERE
CURRENT MODEL CONSENSUS SHOWS POSSIBILITY OF 3" SNOW FALL
(ROUGHLY ALONG/EAST OF HIGHWAY 83). WILL NEED TO MONITOR THIS AS
THIS COULD BE OUR BEST CHANCE TO REACH ADVISORY CRITERIA FOR
SNOWFALL IN THE NEXT 7 DAYS.
REGARDING TEMPS THROUGH THE PERIOD...ARCTIC AIR MASS WILL BE IN
PLACE WITH ONLY SLIGHT MODERATION OCCURRING SATURDAY AHEAD OF
AMPLIFYING TROUGH. RESULT WILL BE BELOW NORMAL TEMPERATURES...WITH
DAYTIME/NIGHT TIME MAX/MINS DEPENDENT ON CLOUD COVERS INFLUENCE
ON MIXING. I TRENDED DAYTIME TEMPS BACK A LITTLE AND BUMPED
OVERNIGHT TEMPS UP (MAINLY TONIGHT) CONSIDERING ONGOING FORECAST
FOR PERSISTENT/THICK CLOUD COVER. OVERALL TEMPERATURES TRENDS
HAVE CHANGED LITTLE FROM PREVIOUS FORECAST.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 254 AM MST THU FEB 26 2015
AN UPPER TROUGH SWINGS THROUGH THE NORTHERN PLAINS DURING THE DAY ON
SUNDAY JUST TO THE NORTH OF THE FORECAST AREA WHILE THE SOUTHERN
BRANCH OF THE UPPER FLOW REMAINS IN PLACE EXTENDING FROM THE FAR
SOUTHWEST U.S. TO THE MID MISSISSIPPI VALLEY REGION. THE UPPER LOW
CENTER THAT HAS BEEN TRAVELING SOUTH ALONG THE WEST COAST IS KICKED
EAST AS AN OPEN WAVE OVER THE SOUTHWEST U.S. AHEAD OF A LOW PRESSURE
AREA DIVING INTO THE PACIFIC NORTHWEST WITH A STRONG JET PUSHING
SOUTH ALONG THE WEST COAST. THIS SHOULD RESULT IN AN ACTIVE WEATHER
PATTERN ACROSS THE CENTRAL HIGH PLAINS REGION THROUGH THE MIDDLE OF
NEXT WEEK AS A NUMBER OF SHORT WAVE TROUGHS LIFTING OUT OF THE MAIN
TROUGH TRANSITION THE REGION IN ADVANCE OF THE MAIN UPPER TROUGH
THAT EVENTUALLY MOVES EAST OF THE ROCKIES ON WEDNESDAY NIGHT/EARLY
THURSDAY.
EXPECT THE PRIMARY SURFACE FRONTAL ZONE TO BE PUSHED UP ALONG THE
ROCKIES AND EXTENDING EAST ACROSS MAINLY THE SOUTHERN HIGH PLAINS
WITH THE OCCASIONAL PUSH NORTH INTO THE FORECAST AREA. HAVE KEPT
TEMPERATURES COLDER THAN AVERAGE THROUGH THE EXTENDED PERIOD AS A
RESULT WITH HIGHS MAINLY IN THE 20S AND 30S AND LOWS IN THE SINGLE
DIGITS TO TEENS. HAVE ALSO BROAD BRUSHED AREAS OF SLIGHT CHANCE TO
CHANCE POPS STRETCHING ACROSS THE FORECAST AREA EACH PERIOD FROM
SUNDAY THROUGH WEDNESDAY NIGHT AS A RESULT OF THE FRONTAL ZONE BEING
IN THE VICINITY WITH THE SHORT WAVE IMPULSES ALSO STREAMING ACROSS
THE AREA. DO NOT EXPECT ANY SIGNIFICANT SNOWFALL AMOUNTS AT THIS
TIME. CONFIDENCE IS VERY LOW IN THE TIMING AND SPECIFIC SNOWFALL
AMOUNTS OVER SPECIFIC LOCATIONS SINCE EVEN SMALL SMALL DIFFERENCES
IS THE POSITION OF FEATURES COULD RESULT IN LARGE DIFFERENCES IS
THE PROBABILITIES OF RECEIVING PRECIPITATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1037 PM MST WED FEB 25 2015
MVFR CONDITIONS ARE EXPECTED AT KGLD AND KMCK OVERNIGHT DUE TO
METARS UPSTREAM SHOWING MVFR CIGS. STRATUS WILL BE SLOW TO BREAK
UP AT KGLD. KMCK WILL BECOME VFR BY MIDDAY AND REMAIN VFR THROUGH
THE REST OF THIS FORECAST PERIOD. THE FORECAST SOUNDING FOR KGLD
INDICATES STRATUS SHOULD RETURN THURSDAY EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JSL
AVIATION...FS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
701 AM CST THU FEB 26 2015
.UPDATE...
ISSUED AT 700 AM CST THU FEB 26 2015
WELL...THE HRRR HAS CONSISTENTLY BEEN UNDERSELLING THE LIGHT
SNOWS OVER KSTL EARLY THIS MORNING. DECIDED TO UPDATE TO INCREASE
POPS IN THE FAR NORTHWEST TO LIKELY FOR A FEW HOURS THIS MORNING.
ALSO INCREASED QPF USING A BLEND OF THE 00Z ECMWF AND 06Z GFS...WHICH
ARE REAL SIMILAR. USING A SLR OF 14:1 GIVES CLOSER TO 3/4" OVER
PERRY COUNTY ILLINOIS THIS MORNING. STILL LOOKING FOR IT TO
DIMINISH TOWARD MIDDAY AS IT MOVES FARTHER SOUTH AND EAST ACROSS
THE AREA.
UPDATE ISSUED AT 546 AM CST THU FEB 26 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 338 AM CST THU FEB 26 2015
A BROAD AREA OF LIGHT SNOW OVER THE NORTHERN HALF OF ILLINOIS
DOWN INTO THE ST LOUIS METRO AREA APPEARS TO BE THE RESULT OF THE
RIGHT ENTRANCE REGION OF A DEPARTING WESTERLY JET ALOFT. ALL 00Z
GUIDANCE AND THE MOST RECENT HRRR...INDICATE A SIGNIFICANT
WEAKENING THROUGH DAYBREAK. THE SNOW WILL DRY TO DEVELOP SOUTHWARD
ALONG THE MS RIVER THROUGH MIDDAY AND THEN REALLY DRY UP AS IT
SPREADS EASTWARD ACROSS THE REMAINDER OF THE REGION THIS AFTERNOON
AND EARLY EVENING.
THE BEST CHANCE AT MEASURABLE SNOWFALL WILL BE ALONG AND NORTHWEST
OF A DONIPHAN MISSOURI TO MT VERNON ILLINOIS LINE THIS MORNING. UP
TO A HALF INCH WILL BE POSSIBLE...BUT MOST PLACES ARE LIKELY TO
ONLY SEE A LIGHT DUSTING. WE WILL CONTINUE TO MONITOR FOR SIGNS OF
A MORE SIGNIFICANT SNOWFALL THIS MORNING.
THIS AFTERNOON...SOME PATCHES OF LIGHT SNOW MAY RESULT IN A
DUSTING IN A FEW LOCATIONS MAINLY OVER WEST KENTUCKY AND SOUTHWEST
INDIANA. FLURRIES WILL BE POSSIBLE OVER MUCH OF THE AREA WELL INTO
THE EVENING HOURS...AS ARCTIC AIR SURGES BACK ACROSS THE REGION.
ARCTIC HIGH PRESSURE WILL SLOWLY BEGIN TO BUILD INTO THE AREA
THROUGH MIDDAY...AND THEN NORTH WINDS WILL REALLY PICK UP AND
BECOME GUSTY THROUGH THE AFTERNOON AND EVENING HOURS. THE
STRONGEST WINDS WILL BE IN THE VICINITY OF 00Z. WITH OVERCAST
CONDITIONS EXPECTED AND FAIRLY STRONG COLD ADVECTION THROUGH THE
DAY...MOST LOCATIONS WILL SEE HIGH TEMPERATURES THIS MORNING WITH
STEADY OR SLOWLY FALLING TEMPERATURES THROUGH THE AFTERNOON. USED
SOME LAMP DATA TO TRY TO REFLECT POSSIBLE HOURLY TEMPERATURE
TRENDS THROUGH THE DAY.
FOR TONIGHT...THERE MAY HAVE BEEN JUST A SLIGHT INCREASE IN
LOWS...WITH A RANGE OF 4 NEAR MT VERNON ILLINOIS TO 14 NEAR FT
CAMPBELL KENTUCKY. WIND CHILLS WILL GENERALLY RANGE FROM ZERO TO
10 BELOW FROM SOUTH TO NORTH ACROSS THE AREA LATE TONIGHT THROUGH
FRIDAY MORNING. WILL CONTINUE TO GIVE THIS A MENTION IN THE HWO.
THE ARCTIC SURFACE HIGH WILL SETTLE JUST NORTH OF THE REGION
FRIDAY AFTERNOON...SO A MODEST NORTHEAST WIND WILL CONTINUE
THROUGH THE DAY AND FRIDAY NIGHT. MAY HAVE NUDGED TEMPERATURE UP
JUST A DEGREE OR SO FROM THE PREVIOUS FORECAST FOR HIGHS FRIDAY
AND LOWS FRIDAY NIGHT. WIND CHILLS OVER THE NORTHERN HALF OF THE
AREA MAY DROPPED JUST A BELOW ZERO FOR A FEW HOURS LATE FRIDAY
NIGHT AND AREA SATURDAY MORNING. WILL ALSO MENTION THIS IN THE
HWO.
THE ARCTIC HIGH WILL QUICKLY BUILD EASTWARD SATURDAY...AS THE
FLOW ALOFT BECOMES RATHER FAST AND ZONAL. WARM ADVECTION
PRECIPITATION IS LIKELY IN THIS SCENARIO...AND THE MODELS TEND TO
BE A LITTLE SLOW WITH THE ONSET. INTRODUCED A SLIGHT CHANCE OF
SNOW TO THE FAR WESTERN PORTIONS OF SOUTHEAST MISSOURI SATURDAY
AFTERNOON JUST TO HINT AT THAT POSSIBILITY.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 338 AM CST THU FEB 26 2015
BROAD WARM AIR ADVECTION WILL ALLOW FOR THE DEVELOPMENT OF
PRECIPITATION SATURDAY NIGHT WITH THE BULK OF IT OCCURRING TO OUR
WEST AND NORTH. LOW LEVELS APPEAR TO BE FAIRLY DRY DURING THE
FIRST PART OF THE EVENING BUT MOISTEN UP NICELY AFTER 06Z SUNDAY.
BEST CHANCES FOR PRECIPITATION WILL BE OVER PARTS OF SOUTHERN IL,
SOUTHWEST IN AND SEMO. ALTHOUGH WAA WILL BE ONGOING...WE WILL
LIKELY HAVE TO DEAL WITH FREEZING PRECIPITATION AT THE ONSET SINCE
WE WILL BE STARTING OUT RATHER COLD. WHILE WE MAY SEE A FEW
SNOWFLAKES EARLY IN THE EVENING, A WARM LAYER ALOFT WOULD MEAN
MORE OF A CHANCE FOR SLEET OR FREEZING RAIN LATER ON. HOWEVER,
SOUNDINGS INDICATE A FAIRLY QUICK WARM UP DURING THE OVERNIGHT
HOURS WHICH SHOULD MEAN A CHANGEOVER TO RAIN BY SOMETIME SUNDAY
MORNING.
NEXT PROBLEM WILL BE TIMING AN INCOMING FRONTAL BOUNDARY FROM THE
NORTHWEST. THE 12Z/00Z ECMWF IS FASTER IN BRINGING IT THROUGH WHILE
THE 00Z GFS IS A BIT SLOWER. THIS HAS IMPLICATIONS ON WHEN THE
HIGHEST POPS SHOULD BE ADVERTISED...I.E. SUNDAY OR SUNDAY NIGHT.
COLD AIR POURS BACK INTO THE REGION BEHIND THIS FRONT. IT LOOKS LIKE
THE PRECIPITATION WILL END BEFORE THE COLD AIR INFILTRATES BUT WILL
SHOW A WINTRY MIX POSSIBLE FOR PARTS OF THE AREA LATE SUNDAY NIGHT
INTO MONDAY JUST IN CASE.
AS WAS SEEN YESTERDAY...IT APPEARS AS THOUGH WE SHOULD HAVE A BRIEF
BREAK ON MONDAY AS HIGH PRESSURE TRIES TO BUILD IN. BUT THAT BREAK
IS DEFINITELY BRIEF AS WE COULD SEE PRECIPITATION SNEAK BACK INTO
THE REGION AS EARLY AS 00Z TUESDAY. OUR NEXT WEATHER SYSTEM DEVELOPS
IN THE ROCKIES AND THEN MOVES INTO THE SOUTH CENTRAL PLAINS EARLY IN
THE WEEK. OF COURSE THERE ARE DIFFERENCES IN THE LOCATION OF THE SFC
LOW BUT MODELS AGREE ON AGGRESSIVELY BRINGING PRECIPITATION BACK
INTO THE AREA MONDAY NIGHT. SOUNDINGS, THICKNESS VALUES AND RAW
MODEL SFC TEMPS INDICATE THAT WE SHOULD BE WARM ENOUGH FOR ALL
LIQUID AS THIS PRECIPITATION RETURNS. THERE MIGHT BE A BRIEF PERIOD
WHERE SOME FREEZING/FROZEN PRECIP IS POSSIBLE AT THE
ONSET...EARLY IN THE EVENING ON MONDAY...ESPECIALLY IN OUR FAR NORTH.
AS THE SFC LOW MOVES TOWARD THE REGION ON TUESDAY INTO TUESDAY
NIGHT...WE COULD BE DEALING WITH SOME HEAVY RAIN AND EVEN SOME
THUNDER ACROSS PORTIONS OF THE REGION BUT WHEN EXACTLY AND WHERE
REMAINS TO BE SEEN AS MODELS OBTAIN A BETTER HANDLE ON THE LOW
PLACEMENT. DEPENDING ON THE EXACT PATH OF THE SFC LOW...WINDS COULD
BECOME SOUTHERLY ACROSS THE AREA ON TUESDAY AND THAT WOULD ALLOW
TEMPERATURES TO REALLY RAMP UP. WE WILL KEEP THINGS CONSERVATIVE FOR
NOW BUT SEEING HOW THE NEW EURO HAS COME IN LINE WITH THE GFS...WILL
RAISE TEMPS. MODELS AGREE THAT THIS SYSTEM WILL MOVE OUT SOMETIME
LATE TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION...
ISSUED AT 546 AM CST THU FEB 26 2015
THE LATEST GUIDANCE AND CURRENT OBSERVATIONAL TRENDS SUPPORT
PUSHING BACK THE ARRIVAL OF MVFR CEILINGS AND GUSTY NORTH WINDS
ASSOCIATED WITH THE ARCTIC SURGE TODAY. A NICE AREA OF MVFR SNOW
OVER KSTL AND POINTS NORTH IS EXPECTED TO DRY UP AS IT ATTEMPTS TO
SPREAD SOUTH AND EAST INTO OUR REGION. THREW IN A MENTION OF VFR
SNOW AT ALL SITES FOR A FEW HOURS WITH THE INTIAL ARRIVAL OF THE
MVFR CEILINGS. GUIDANCE APPEARS TO BE UNDER-ESTIMATING THE SNOW
AT THIS TIME...SO WILL HAVE TO MONITOR CLOSELY FOR MORE
SIGNIFICANT SNOWS AT ALL SITES TODAY. THERE IS SOME EVIDENCE THAT
THE MVFR CEILINGS MAY SCATTER OUT AT KEVV AND KOWB PRIOR TO 12Z
FRIDAY.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...CW
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS JACKSON KY
159 AM EST THU FEB 26 2015
.UPDATE...
ISSUED AT 158 AM EST THU FEB 26 2015
UPDATED THE FORECAST TO HIGHLIGHT A BANDED AREA OF PRECIP THAT HAS
DEVELOPED ALONG A LINE FROM MT VERNON AND NORTHEAST THROUGH WEST
LIBERTY. THIS HAS DEVELOPED ALONG A 700MB LINE OF FRONTOGENESIS
AND WILL SATURATE THE LOWER LEVELS IN A SHORT PERIOD OF TIME. WITH
THIS...THE HRRR AND SREF INDICATE OF A PERIOD OF TIME RESIDENCE
TIME THROUGH THE NEXT COUPLE OF HOURS. THIS WILL BE ENOUGH PERIOD
OF TIME FOR GREATER THAN AN INCH TO POSSIBLY TWO INCHES ALONG THIS
LINE...ESPECIALLY WITH THE LOW THAT IS SLOW TO EXIT TO THE EAST. A
NEW ZFP HAS BEEN SENT OUT FOR THIS UPDATE AND THE WSW HAS BEEN
EXTENDED TO A TIER OF COUNTIES TO THE NORTH.
UPDATE ISSUED AT 1125 PM EST WED FEB 25 2015
GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT RADAR TRENDS AND NEAR
TERM GUIDANCE. SNOW HAS BEEN REPORTED TO BE REACHING THE GROUND
FROM MCCREARY COUNTY OVER TO KNOX COUNTY AND LESLIE COUNTY TO
LETCHER COUNTY. SOCIAL MEDIA WOULD INDICATE ABOUT HALF AN INCH OR
SO OF NEW SNOW IN HARLAN COUNTY. THE ONLY OTHER CHANGE WITH THIS
UPDATE WAS TO INCREASE QPF SLIGHTLY ALONG THE VA BORDER WHICH LED
TO SOLID 2 TO 3 INCH AMOUNTS FROM BELL COUNTY THROUGH HARLAN
COUNTY INTO LETCHER COUNTY. AT 2000 FEET AND ABOVE IN THESE
COUNTIES AS WELL AS PIKE COUNTY IN THE FLATWOODS AREAS TOTALS
AROUND 4 INCHES WILL BE POSSIBLE. THERE IS STILL SOME UNCERTAINTY
IN THE NORTHWARD EXTENT OF THE SHARP CUTOFF WITH SOME WAFFLING
FROM RUN TO RUN OF THE HRRR. HOWEVER...THE AVERAGE OF THE PAST FEW
HOURS STILL SUPPORTS THE CURRENT AREAL EXTENT OF THE ADVISORY.
UPDATE ISSUED AT 800 PM EST WED FEB 25 2015
SOME MINOR ADJUSTMENTS HAVE BEEN MADE TO HOURLY GRIDS FOR THE
OVERNIGHT PERIOD INTO EARLY ON THURSDAY. INITIALLY THESE WERE
BASED ON RECENT OBSERVATION AND RADAR TRENDS AS WELL AS THE RECENT
22Z AND 23Z HRRR RUNS WITH A CONSIDERATION OF 21Z SREF QPF AS
WELL. THIS LED TO COOLING OFF THE HIGHER TERRAIN WHERE WETBULBING
APPEARS TO ALREADY HAVE BEGUN AND QPF WAS NUDGED UP A TAD FOR
THESE HIGHER TERRAIN LOCATIONS BORDERING VA. THE TOP OF BLACK MTN
HAS AN RH NEAR 75 PERCENT.
AT THIS POINT...WE ARE IN THE WAIT FOR THE ATMOSPHERE TO CONTINUE
MOISTENING UP FROM THE TOP DOWN. UPSTREAM OF EASTERN KY...THE
SNOW IS NOW REACHING THE GROUND IN THE KTYS AND KGKT OR KNOXVILLE
AND SEVIERVILLE/GATLINBURG AREAS AS WELL AS AT KCSV AND KOQT.
BASED ON THIS...THE RECENT HRRR SEEMS TO HAVE A DECENT HANDLE ON
NORTHWARD PROGRESS OF THE AREA OF SNOW. THIS SHOULD BRING THE SNOW
INTO THE SOUTHERN PART OF THE CWA AROUND WHITLEY...HARLAN AND BELL
COUNTIES AROUND OR SHORTLY BEFORE 10 PM AND THEN GRADUALLY SPREAD
NORTH AND EAST. HOWEVER...THE 18Z OPERATIONAL RUNS AND THE RECENT
NEAR TERM GUIDANCE SUCH AS THE HRRR RUNS INDICATE THAT THE SNOW
WILL PROBABLY NOT MAKE IT MUCH FURTHER NORTH THE NORTHERN END OF
THE ADVISORY AS THERE WILL BE A SHARP NORTH OR NORTHWEST CUTOFF.
IN FACT...ACROSS THE NORTHERN TIER OF THE ADVISORY AMOUNTS COULD
RANGE FROM NOT MORE THAN A DUSTING IN THE NORTHERN OR NORTHWESTERN
END OF THE COUNTIES TO AN INCH OR MORE IN THE SOUTHERN END OF
THESE COUNTIES. IT STILL APPEARS THAT 2 TO 3 INCHES SHOULD BE
COMMON FROM SOUTHERN WHITELY COUNTY THROUGH BELL COUNTY NORTHEAST
ACROSS HARLAN AND LETCHER COUNTIES TO SOUTHERN PIKE COUNTY.
AMOUNTS AROUND 4 INCHES CANNOT BE RULED OUT ABOVE 3000 FEET.
POPS WERE RAISED FROM LIKELY TO CATEGORICAL FOR NEARLY ALL OF THE
AREA OF THE COUNTIES ON THE NORTHERN END OF THE ADVISORY. THE
SLIGHTLY HIGHER QPF LED TO SLIGHTLY HIGHER SNOWFALL FOR ELEVATIONS
OF 2000 FEET AND ABOVE FROM BELL COUNTY NORTHEAST TO EXTREME
SOUTHERN PIKE COUNTY. ATTM...THE ADVISORY CONTINUES TO REMAIN
VALID AND NO CHANGES ARE EXPECTED AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 500 PM EST WED FEB 25 2015
20Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE APPROACHING FROM
THE NORTHWEST WHILE ANOTHER IS MOVING IN FROM THE SOUTHWEST. IT IS
THIS SOUTHERN ONE WITH ITS WELL DEVELOPED PCPN SHIELD THAT WILL
GIVE MUCH OF THE AREA A DECENT CHANCE OF ACCUMULATING SNOW LATER
TONIGHT. UNDER OVERCAST SKIES TEMPERATURES ARE PEAKING INTO THE
MID 30S WHILE THE DEWPOINTS ARE STILL IN THE MID TEENS MOST
PLACES...THOUGH LOW 20S ARE FOUND IN THE FAR SOUTHWEST PARTS OF
THE CWA. WINDS ARE GENERALLY FROM THE NORTHEAST AT AROUND 5 MPH.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH A DAMPENING BUT STILL
RATHER ROBUST SOUTHERN STREAM WAVE MOVING THROUGH THE SOUTHERN
APPALACHIANS. THIS IS TRAILED BY A ANOTHER...MORE BROAD...UPPER
LEVEL TROUGH THAT WILL CROSS THE OHIO VALLEY LATER THURSDAY AND
INTO THURSDAY NIGHT. AT THE SAME TIME...ANOTHER WEAKER WAVE WILL
PASS SOUTH OF KENTUCKY IN THE SOUTHERN STREAM. THESE STREAMS
REMAIN SEPARATE ENOUGH THROUGH THE SHORT TERM PORTION OF THE
FORECAST THAT THEIR SFC REFLECTIONS WILL LIKEWISE REMAIN ON THE
WEAKER SIDE OF POTENTIAL. GIVEN THE MODEL AGREEMENT ALOFT...AND
THE HIGHER RESOLUTION OF THE NAM12 AND HRRR...HAVE FOLLOWED THOSE
LATTER MODELS MOST CLOSELY FOR WX SPECIFICS.
SENSIBLE WEATHER WILL FEATURE THE EXPANDING NORTHERN FRINGE OF THE
SOUTHERN LOW STRAFING EASTERN KENTUCKY WITH SNOW ARRIVING SHORTLY
AFTER SUNSET AND THEN QUICKLY SPREADING NORTHEAST INTO THE LATTER
PART OF THE EVENING. THE DYNAMICS OF THIS SYSTEM AS SEEN IN THE
HIGHER RESOLUTION MODELS SUGGEST THAT THE SNOW COULD COME DOWN
BRIEFLY HEAVY WHEN IT SETS IN. THE LAST COUPLE OF RUNS OF THE
HRRR AND THE 18Z NAM12 DID PUSH SOME OF THE HIGHER QPF AND OMEGA A
TAD FURTHER NORTH INTO EASTERN KENTUCKY. SO WITH THIS AGREEMENT
AND THE POTENTIAL FOR QUICK ACCUMULATIONS HAVE DECIDED TO ADD
SEVERAL MORE COUNTIES TO THE INITIAL ADVISORY FROM MARTIN WEST TO
OWSLEY COUNTY. OTHERWISE...THE FORECAST IS ON TRACK WITH BETWEEN 1
AND 2 INCHES OF ACCUMULATION POSSIBLE MOST PLACES IN THE
ADVISORY...A BIT LESS IN THE WEST AND NORTH WITH HIGHER AMOUNTS
CLOSER TO THE VIRGINIA BORDER...PARTICULARLY FOR ELEVATIONS ABOVE
2500 FEET.
THE SNOW WILL TAPER TO FLURRIES AND POSSIBLE END FOR A TIME OVER
MOST OF THE AREA BY MIDDAY THURSDAY BEFORE THE APPROACH OF THAT
NEXT MID LEVEL TROUGH AND A SFC ARCTIC FRONT. SIMILAR TO SOME OF
THE FRONTS WE HAVE SEEN SO FAR THIS WINTER...WE EXPECT SNOW SHOWER
DEVELOPMENT ALONG AND BEHIND IT INTO THE NIGHT THURSDAY WITH BEST
LIFT AND FORCING TAKING PLACE IN THE EVENING. UP TO AN INCH OF
ADDITIONAL ACCUMULATION WILL BE POSSIBLE FROM THIS SET UP...BUT
MOST PLACES WILL SEE JUST A DUSTING OR TWO OF ACCUMULATION. ARCTIC
TEMPERATURES WILL SEND READINGS INTO THE TEENS MOST PLACES BY
FRIDAY MORNING.
USED THE CONSSHORT TO JUMP START THE T/TD/WIND GRIDS THROUGH THE
DAY THURSDAY...WITH SOME TERRAIN BASED ADJUSTMENTS. AFTER THAT
FAVORED THE SUPERBLEND INTO FRIDAY MORNING FOR A STARTING POINT.
AS FOR POPS...ENDED UP ON THE HIGH SIDE OF GUIDANCE THROUGH THE
PERIOD.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 345 PM EST WED FEB 25 2015
BROAD MID AND UPPER LEVEL TROUGH ACROSS THE ENTIRE CONUS WILL DEEPEN
OVER THE FAR SOUTHWEST...BAJA THROUGH THE WEEKEND PLACING OUR AREA
IN A GENERAL SOUTHWEST FLOW REGIME FOR THE BULK OF THE EXTENDED.
THIS WILL TEND TO KEEP STORM TRACKS SOMEWHAT CENTERED OVER THE OHIO
VALLEY REGION AS A SERIES OF DISTURBANCES RIDE NORTHEAST ACROSS THE
EASTERN CONUS. OVERALL IT APPEARS WE WILL BE GETTING INTO A VERY
ACTIVE WEATHER PATTERN...TYPICAL FOR THE APPROACH OF EARLY SPRING.
ACTUAL SENSIBLE WEATHER...PRECIPITATION TYPES...AMOUNTS ETC. WILL
DEPEND MORE ON EXACT TRACK OF SURFACE LOWS THROUGH THE REGION.
CONSIDERING THE CURRENT SNOWPACK ALONG WITH THE WATER CONTENT
PRESENT ACROSS A LARGE PART OF THE AREA...POTENTIAL HYDRO ISSUES
WILL NEED TO BE CONSIDERED SHOULD MUCH OF ANY PRECIPITATION WE
REALIZE THROUGH THE PERIOD FALL IN THE FORM OF RAIN.
MODEL SOLUTIONS APPEAR TO BE IN FAIRLY GOOD AGREEMENT THROUGH THE
EXTENDED. A SERIES OF STORM SYSTEMS SHOOT OUT OF THE INTER-MOUNTAIN/
SOUTH CENTRAL PLAINS AREA IN RAPID FIRE FASHION THROUGH THE PERIOD.
THE FIRST SHOULD AFFECT OUR AREA SUNDAY INTO MONDAY...THE SECOND
TUESDAY THROUGH EARLY WEDNESDAY AND THEN THE THIRD LATE WEDNESDAY
NIGHT INTO THURSDAY. ATTM MODEL CONSENSUS IS FOR SFC LOWS TO TRACK
GENERALLY TO OUR NORTHWEST...KEEPING OUR AREA IN THE WARM SECTORS OF
THESE SYSTEMS. HOWEVER...THE COLDER AIR THAT FILTERS IN BEHIND EACH
PASSING SYSTEM MAY ALLOW FOR THE A WINTRY MIX AT THE ONSET OF EACH
NEW ROUND OF WEATHER. THIS MAY BE ESPECIALLY TRUE NEXT TUESDAY
MORNING. AFTER A VERY COLD START FOR FRIDAY...EXPECT TEMPERATURES TO
GRADUALLY MODERATE TOWARDS MORE NORMAL LEVELS THROUGH THE EXTENDED
THOUGH OVERALL WE WILL REMAIN BELOW NORMS FOR THIS TIME OF THE
YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1222 AM EST THU FEB 26 2015
LOW LEVEL CIGS AND SNOWFALL WILL CONTINUE TO CREEP NORTH AND
NORTHEASTWARD THROUGH THE NIGHT AS THE LOW PRESSURE SYSTEM TRACKS
EAST ACROSS THE APPALACHIAN RANGE TONIGHT. THESE BELOW IFR CIGS
AT TIMES AND LOW VISIBILITY WILL CONTINUE AT MOST OF THE TAF SITES
BESIDES SYM THROUGH 14Z. WINDS WILL GENERALLY BE LIGHT AND
VARIABLE OR MAINLY OUT OF THE NORTH. HEADING INTO THE
AFTERNOON...THE SNOW WILL TRANSITION INTO UPSLOPE SNOW SHOWERS
THROUGH THE AFTERNOON WITH MAINLY FLURRIES AND A PERSISTENT MVFR
CIGS THROUGH THE REST OF THE TAF PERIOD. WINDS WILL INCREASE OUT
OF THE NORTHWEST THROUGH THIS PERIOD AS WELL.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR
KYZ058>060-068-069-079-080-083>088-106>120.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM...RAY
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
1222 AM EST THU FEB 26 2015
.UPDATE...
ISSUED AT 1125 PM EST WED FEB 25 2015
GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT RADAR TRENDS AND NEAR
TERM GUIDANCE. SNOW HAS BEEN REPORTED TO BE REACHING THE GROUND
FROM MCCREARY COUNTY OVER TO KNOX COUNTY AND LESLIE COUNTY TO
LETCHER COUNTY. SOCIAL MEDIA WOULD INDICATE ABOUT HALF AN INCH OR
SO OF NEW SNOW IN HARLAN COUNTY. THE ONLY OTHER CHANGE WITH THIS
UPDATE WAS TO INCREASE QPF SLIGHTLY ALONG THE VA BORDER WHICH LED
TO SOLID 2 TO 3 INCH AMOUNTS FROM BELL COUNTY THROUGH HARLAN
COUNTY INTO LETCHER COUNTY. AT 2000 FEET AND ABOVE IN THESE
COUNTIES AS WELL AS PIKE COUNTY IN THE FLATWOODS AREAS TOTALS
AROUND 4 INCHES WILL BE POSSIBLE. THERE IS STILL SOME UNCERTAINTY
IN THE NORTHWARD EXTENT OF THE SHARP CUTOFF WITH SOME WAFFLING
FROM RUN TO RUN OF THE HRRR. HOWEVER...THE AVERAGE OF THE PAST FEW
HOURS STILL SUPPORTS THE CURRENT AREAL EXTENT OF THE ADVISORY.
UPDATE ISSUED AT 800 PM EST WED FEB 25 2015
SOME MINOR ADJUSTMENTS HAVE BEEN MADE TO HOURLY GRIDS FOR THE
OVERNIGHT PERIOD INTO EARLY ON THURSDAY. INITIALLY THESE WERE
BASED ON RECENT OBSERVATION AND RADAR TRENDS AS WELL AS THE RECENT
22Z AND 23Z HRRR RUNS WITH A CONSIDERATION OF 21Z SREF QPF AS
WELL. THIS LED TO COOLING OFF THE HIGHER TERRAIN WHERE WETBULBING
APPEARS TO ALREADY HAVE BEGUN AND QPF WAS NUDGED UP A TAD FOR
THESE HIGHER TERRAIN LOCATIONS BORDERING VA. THE TOP OF BLACK MTN
HAS AN RH NEAR 75 PERCENT.
AT THIS POINT...WE ARE IN THE WAIT FOR THE ATMOSPHERE TO CONTINUE
MOISTENING UP FROM THE TOP DOWN. UPSTREAM OF EASTERN KY...THE
SNOW IS NOW REACHING THE GROUND IN THE KTYS AND KGKT OR KNOXVILLE
AND SEVIERVILLE/GATLINBURG AREAS AS WELL AS AT KCSV AND KOQT.
BASED ON THIS...THE RECENT HRRR SEEMS TO HAVE A DECENT HANDLE ON
NORTHWARD PROGRESS OF THE AREA OF SNOW. THIS SHOULD BRING THE SNOW
INTO THE SOUTHERN PART OF THE CWA AROUND WHITLEY...HARLAN AND BELL
COUNTIES AROUND OR SHORTLY BEFORE 10 PM AND THEN GRADUALLY SPREAD
NORTH AND EAST. HOWEVER...THE 18Z OPERATIONAL RUNS AND THE RECENT
NEAR TERM GUIDANCE SUCH AS THE HRRR RUNS INDICATE THAT THE SNOW
WILL PROBABLY NOT MAKE IT MUCH FURTHER NORTH THE NORTHERN END OF
THE ADVISORY AS THERE WILL BE A SHARP NORTH OR NORTHWEST CUTOFF.
IN FACT...ACROSS THE NORTHERN TIER OF THE ADVISORY AMOUNTS COULD
RANGE FROM NOT MORE THAN A DUSTING IN THE NORTHERN OR NORTHWESTERN
END OF THE COUNTIES TO AN INCH OR MORE IN THE SOUTHERN END OF
THESE COUNTIES. IT STILL APPEARS THAT 2 TO 3 INCHES SHOULD BE
COMMON FROM SOUTHERN WHITELY COUNTY THROUGH BELL COUNTY NORTHEAST
ACROSS HARLAN AND LETCHER COUNTIES TO SOUTHERN PIKE COUNTY.
AMOUNTS AROUND 4 INCHES CANNOT BE RULED OUT ABOVE 3000 FEET.
POPS WERE RAISED FROM LIKELY TO CATEGORICAL FOR NEARLY ALL OF THE
AREA OF THE COUNTIES ON THE NORTHERN END OF THE ADVISORY. THE
SLIGHTLY HIGHER QPF LED TO SLIGHTLY HIGHER SNOWFALL FOR ELEVATIONS
OF 2000 FEET AND ABOVE FROM BELL COUNTY NORTHEAST TO EXTREME
SOUTHERN PIKE COUNTY. ATTM...THE ADVISORY CONTINUES TO REMAIN
VALID AND NO CHANGES ARE EXPECTED AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 500 PM EST WED FEB 25 2015
20Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE APPROACHING FROM
THE NORTHWEST WHILE ANOTHER IS MOVING IN FROM THE SOUTHWEST. IT IS
THIS SOUTHERN ONE WITH ITS WELL DEVELOPED PCPN SHIELD THAT WILL
GIVE MUCH OF THE AREA A DECENT CHANCE OF ACCUMULATING SNOW LATER
TONIGHT. UNDER OVERCAST SKIES TEMPERATURES ARE PEAKING INTO THE
MID 30S WHILE THE DEWPOINTS ARE STILL IN THE MID TEENS MOST
PLACES...THOUGH LOW 20S ARE FOUND IN THE FAR SOUTHWEST PARTS OF
THE CWA. WINDS ARE GENERALLY FROM THE NORTHEAST AT AROUND 5 MPH.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH A DAMPENING BUT STILL
RATHER ROBUST SOUTHERN STREAM WAVE MOVING THROUGH THE SOUTHERN
APPALACHIANS. THIS IS TRAILED BY A ANOTHER...MORE BROAD...UPPER
LEVEL TROUGH THAT WILL CROSS THE OHIO VALLEY LATER THURSDAY AND
INTO THURSDAY NIGHT. AT THE SAME TIME...ANOTHER WEAKER WAVE WILL
PASS SOUTH OF KENTUCKY IN THE SOUTHERN STREAM. THESE STREAMS
REMAIN SEPARATE ENOUGH THROUGH THE SHORT TERM PORTION OF THE
FORECAST THAT THEIR SFC REFLECTIONS WILL LIKEWISE REMAIN ON THE
WEAKER SIDE OF POTENTIAL. GIVEN THE MODEL AGREEMENT ALOFT...AND
THE HIGHER RESOLUTION OF THE NAM12 AND HRRR...HAVE FOLLOWED THOSE
LATTER MODELS MOST CLOSELY FOR WX SPECIFICS.
SENSIBLE WEATHER WILL FEATURE THE EXPANDING NORTHERN FRINGE OF THE
SOUTHERN LOW STRAFING EASTERN KENTUCKY WITH SNOW ARRIVING SHORTLY
AFTER SUNSET AND THEN QUICKLY SPREADING NORTHEAST INTO THE LATTER
PART OF THE EVENING. THE DYNAMICS OF THIS SYSTEM AS SEEN IN THE
HIGHER RESOLUTION MODELS SUGGEST THAT THE SNOW COULD COME DOWN
BRIEFLY HEAVY WHEN IT SETS IN. THE LAST COUPLE OF RUNS OF THE
HRRR AND THE 18Z NAM12 DID PUSH SOME OF THE HIGHER QPF AND OMEGA A
TAD FURTHER NORTH INTO EASTERN KENTUCKY. SO WITH THIS AGREEMENT
AND THE POTENTIAL FOR QUICK ACCUMULATIONS HAVE DECIDED TO ADD
SEVERAL MORE COUNTIES TO THE INITIAL ADVISORY FROM MARTIN WEST TO
OWSLEY COUNTY. OTHERWISE...THE FORECAST IS ON TRACK WITH BETWEEN 1
AND 2 INCHES OF ACCUMULATION POSSIBLE MOST PLACES IN THE
ADVISORY...A BIT LESS IN THE WEST AND NORTH WITH HIGHER AMOUNTS
CLOSER TO THE VIRGINIA BORDER...PARTICULARLY FOR ELEVATIONS ABOVE
2500 FEET.
THE SNOW WILL TAPER TO FLURRIES AND POSSIBLE END FOR A TIME OVER
MOST OF THE AREA BY MIDDAY THURSDAY BEFORE THE APPROACH OF THAT
NEXT MID LEVEL TROUGH AND A SFC ARCTIC FRONT. SIMILAR TO SOME OF
THE FRONTS WE HAVE SEEN SO FAR THIS WINTER...WE EXPECT SNOW SHOWER
DEVELOPMENT ALONG AND BEHIND IT INTO THE NIGHT THURSDAY WITH BEST
LIFT AND FORCING TAKING PLACE IN THE EVENING. UP TO AN INCH OF
ADDITIONAL ACCUMULATION WILL BE POSSIBLE FROM THIS SET UP...BUT
MOST PLACES WILL SEE JUST A DUSTING OR TWO OF ACCUMULATION. ARCTIC
TEMPERATURES WILL SEND READINGS INTO THE TEENS MOST PLACES BY
FRIDAY MORNING.
USED THE CONSSHORT TO JUMP START THE T/TD/WIND GRIDS THROUGH THE
DAY THURSDAY...WITH SOME TERRAIN BASED ADJUSTMENTS. AFTER THAT
FAVORED THE SUPERBLEND INTO FRIDAY MORNING FOR A STARTING POINT.
AS FOR POPS...ENDED UP ON THE HIGH SIDE OF GUIDANCE THROUGH THE
PERIOD.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 345 PM EST WED FEB 25 2015
BROAD MID AND UPPER LEVEL TROUGH ACROSS THE ENTIRE CONUS WILL DEEPEN
OVER THE FAR SOUTHWEST...BAJA THROUGH THE WEEKEND PLACING OUR AREA
IN A GENERAL SOUTHWEST FLOW REGIME FOR THE BULK OF THE EXTENDED.
THIS WILL TEND TO KEEP STORM TRACKS SOMEWHAT CENTERED OVER THE OHIO
VALLEY REGION AS A SERIES OF DISTURBANCES RIDE NORTHEAST ACROSS THE
EASTERN CONUS. OVERALL IT APPEARS WE WILL BE GETTING INTO A VERY
ACTIVE WEATHER PATTERN...TYPICAL FOR THE APPROACH OF EARLY SPRING.
ACTUAL SENSIBLE WEATHER...PRECIPITATION TYPES...AMOUNTS ETC. WILL
DEPEND MORE ON EXACT TRACK OF SURFACE LOWS THROUGH THE REGION.
CONSIDERING THE CURRENT SNOWPACK ALONG WITH THE WATER CONTENT
PRESENT ACROSS A LARGE PART OF THE AREA...POTENTIAL HYDRO ISSUES
WILL NEED TO BE CONSIDERED SHOULD MUCH OF ANY PRECIPITATION WE
REALIZE THROUGH THE PERIOD FALL IN THE FORM OF RAIN.
MODEL SOLUTIONS APPEAR TO BE IN FAIRLY GOOD AGREEMENT THROUGH THE
EXTENDED. A SERIES OF STORM SYSTEMS SHOOT OUT OF THE INTER-MOUNTAIN/
SOUTH CENTRAL PLAINS AREA IN RAPID FIRE FASHION THROUGH THE PERIOD.
THE FIRST SHOULD AFFECT OUR AREA SUNDAY INTO MONDAY...THE SECOND
TUESDAY THROUGH EARLY WEDNESDAY AND THEN THE THIRD LATE WEDNESDAY
NIGHT INTO THURSDAY. ATTM MODEL CONSENSUS IS FOR SFC LOWS TO TRACK
GENERALLY TO OUR NORTHWEST...KEEPING OUR AREA IN THE WARM SECTORS OF
THESE SYSTEMS. HOWEVER...THE COLDER AIR THAT FILTERS IN BEHIND EACH
PASSING SYSTEM MAY ALLOW FOR THE A WINTRY MIX AT THE ONSET OF EACH
NEW ROUND OF WEATHER. THIS MAY BE ESPECIALLY TRUE NEXT TUESDAY
MORNING. AFTER A VERY COLD START FOR FRIDAY...EXPECT TEMPERATURES TO
GRADUALLY MODERATE TOWARDS MORE NORMAL LEVELS THROUGH THE EXTENDED
THOUGH OVERALL WE WILL REMAIN BELOW NORMS FOR THIS TIME OF THE
YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1222 AM EST THU FEB 26 2015
LOW LEVEL CIGS AND SNOWFALL WILL CONTINUE TO CREEP NORTH AND
NORTHEASTWARD THROUGH THE NIGHT AS THE LOW PRESSURE SYSTEM TRACKS
EAST ACROSS THE APPALACHIAN RANGE TONIGHT. THESE BELOW IFR CIGS
AT TIMES AND LOW VISIBILITY WILL CONTINUE AT MOST OF THE TAF SITES
BESIDES SYM THROUGH 14Z. WINDS WILL GENERALLY BE LIGHT AND
VARIABLE OR MAINLY OUT OF THE NORTH. HEADING INTO THE
AFTERNOON...THE SNOW WILL TRANSITION INTO UPSLOPE SNOW SHOWERS
THROUGH THE AFTERNOON WITH MAINLY FLURRIES AND A PERSISTENT MVFR
CIGS THROUGH THE REST OF THE TAF PERIOD. WINDS WILL INCREASE OUT
OF THE NORTHWEST THROUGH THIS PERIOD AS WELL.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR KYZ079-
080-083>088-107-109-110-112>120.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...RAY
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1133 PM EST WED FEB 25 2015
.UPDATE...
ISSUED AT 1125 PM EST WED FEB 25 2015
GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT RADAR TRENDS AND NEAR
TERM GUIDANCE. SNOW HAS BEEN REPORTED TO BE REACHING THE GROUND
FROM MCCREARY COUNTY OVER TO KNOX COUNTY AND LESLIE COUNTY TO
LETCHER COUNTY. SOCIAL MEDIA WOULD INDICATE ABOUT HALF AN INCH OR
SO OF NEW SNOW IN HARLAN COUNTY. THE ONLY OTHER CHANGE WITH THIS
UPDATE WAS TO INCREASE QPF SLIGHTLY ALONG THE VA BORDER WHICH LED
TO SOLID 2 TO 3 INCH AMOUNTS FROM BELL COUNTY THROUGH HARLAN
COUNTY INTO LETCHER COUNTY. AT 2000 FEET AND ABOVE IN THESE
COUNTIES AS WELL AS PIKE COUNTY IN THE FLATWOODS AREAS TOTALS
AROUND 4 INCHES WILL BE POSSIBLE. THERE IS STILL SOME UNCERTAINTY
IN THE NORTHWARD EXTENT OF THE SHARP CUTOFF WITH SOME WAFFLING
FROM RUN TO RUN OF THE HRRR. HOWEVER...THE AVERAGE OF THE PAST FEW
HOURS STILL SUPPORTS THE CURRENT AREAL EXTENT OF THE ADVISORY.
UPDATE ISSUED AT 800 PM EST WED FEB 25 2015
SOME MINOR ADJUSTMENTS HAVE BEEN MADE TO HOURLY GRIDS FOR THE
OVERNIGHT PERIOD INTO EARLY ON THURSDAY. INITIALLY THESE WERE
BASED ON RECENT OBSERVATION AND RADAR TRENDS AS WELL AS THE RECENT
22Z AND 23Z HRRR RUNS WITH A CONSIDERATION OF 21Z SREF QPF AS
WELL. THIS LED TO COOLING OFF THE HIGHER TERRAIN WHERE WETBULBING
APPEARS TO ALREADY HAVE BEGUN AND QPF WAS NUDGED UP A TAD FOR
THESE HIGHER TERRAIN LOCATIONS BORDERING VA. THE TOP OF BLACK MTN
HAS AN RH NEAR 75 PERCENT.
AT THIS POINT...WE ARE IN THE WAIT FOR THE ATMOSPHERE TO CONTINUE
MOISTENING UP FROM THE TOP DOWN. UPSTREAM OF EASTERN KY...THE
SNOW IS NOW REACHING THE GROUND IN THE KTYS AND KGKT OR KNOXVILLE
AND SEVIERVILLE/GATLINBURG AREAS AS WELL AS AT KCSV AND KOQT.
BASED ON THIS...THE RECENT HRRR SEEMS TO HAVE A DECENT HANDLE ON
NORTHWARD PROGRESS OF THE AREA OF SNOW. THIS SHOULD BRING THE SNOW
INTO THE SOUTHERN PART OF THE CWA AROUND WHITLEY...HARLAN AND BELL
COUNTIES AROUND OR SHORTLY BEFORE 10 PM AND THEN GRADUALLY SPREAD
NORTH AND EAST. HOWEVER...THE 18Z OPERATIONAL RUNS AND THE RECENT
NEAR TERM GUIDANCE SUCH AS THE HRRR RUNS INDICATE THAT THE SNOW
WILL PROBABLY NOT MAKE IT MUCH FURTHER NORTH THE NORTHERN END OF
THE ADVISORY AS THERE WILL BE A SHARP NORTH OR NORTHWEST CUTOFF.
IN FACT...ACROSS THE NORTHERN TIER OF THE ADVISORY AMOUNTS COULD
RANGE FROM NOT MORE THAN A DUSTING IN THE NORTHERN OR NORTHWESTERN
END OF THE COUNTIES TO AN INCH OR MORE IN THE SOUTHERN END OF
THESE COUNTIES. IT STILL APPEARS THAT 2 TO 3 INCHES SHOULD BE
COMMON FROM SOUTHERN WHITELY COUNTY THROUGH BELL COUNTY NORTHEAST
ACROSS HARLAN AND LETCHER COUNTIES TO SOUTHERN PIKE COUNTY.
AMOUNTS AROUND 4 INCHES CANNOT BE RULED OUT ABOVE 3000 FEET.
POPS WERE RAISED FROM LIKELY TO CATEGORICAL FOR NEARLY ALL OF THE
AREA OF THE COUNTIES ON THE NORTHERN END OF THE ADVISORY. THE
SLIGHTLY HIGHER QPF LED TO SLIGHTLY HIGHER SNOWFALL FOR ELEVATIONS
OF 2000 FEET AND ABOVE FROM BELL COUNTY NORTHEAST TO EXTREME
SOUTHERN PIKE COUNTY. ATTM...THE ADVISORY CONTINUES TO REMAIN
VALID AND NO CHANGES ARE EXPECTED AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 500 PM EST WED FEB 25 2015
20Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE APPROACHING FROM
THE NORTHWEST WHILE ANOTHER IS MOVING IN FROM THE SOUTHWEST. IT IS
THIS SOUTHERN ONE WITH ITS WELL DEVELOPED PCPN SHIELD THAT WILL
GIVE MUCH OF THE AREA A DECENT CHANCE OF ACCUMULATING SNOW LATER
TONIGHT. UNDER OVERCAST SKIES TEMPERATURES ARE PEAKING INTO THE
MID 30S WHILE THE DEWPOINTS ARE STILL IN THE MID TEENS MOST
PLACES...THOUGH LOW 20S ARE FOUND IN THE FAR SOUTHWEST PARTS OF
THE CWA. WINDS ARE GENERALLY FROM THE NORTHEAST AT AROUND 5 MPH.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH A DAMPENING BUT STILL
RATHER ROBUST SOUTHERN STREAM WAVE MOVING THROUGH THE SOUTHERN
APPALACHIANS. THIS IS TRAILED BY A ANOTHER...MORE BROAD...UPPER
LEVEL TROUGH THAT WILL CROSS THE OHIO VALLEY LATER THURSDAY AND
INTO THURSDAY NIGHT. AT THE SAME TIME...ANOTHER WEAKER WAVE WILL
PASS SOUTH OF KENTUCKY IN THE SOUTHERN STREAM. THESE STREAMS
REMAIN SEPARATE ENOUGH THROUGH THE SHORT TERM PORTION OF THE
FORECAST THAT THEIR SFC REFLECTIONS WILL LIKEWISE REMAIN ON THE
WEAKER SIDE OF POTENTIAL. GIVEN THE MODEL AGREEMENT ALOFT...AND
THE HIGHER RESOLUTION OF THE NAM12 AND HRRR...HAVE FOLLOWED THOSE
LATTER MODELS MOST CLOSELY FOR WX SPECIFICS.
SENSIBLE WEATHER WILL FEATURE THE EXPANDING NORTHERN FRINGE OF THE
SOUTHERN LOW STRAFING EASTERN KENTUCKY WITH SNOW ARRIVING SHORTLY
AFTER SUNSET AND THEN QUICKLY SPREADING NORTHEAST INTO THE LATTER
PART OF THE EVENING. THE DYNAMICS OF THIS SYSTEM AS SEEN IN THE
HIGHER RESOLUTION MODELS SUGGEST THAT THE SNOW COULD COME DOWN
BRIEFLY HEAVY WHEN IT SETS IN. THE LAST COUPLE OF RUNS OF THE
HRRR AND THE 18Z NAM12 DID PUSH SOME OF THE HIGHER QPF AND OMEGA A
TAD FURTHER NORTH INTO EASTERN KENTUCKY. SO WITH THIS AGREEMENT
AND THE POTENTIAL FOR QUICK ACCUMULATIONS HAVE DECIDED TO ADD
SEVERAL MORE COUNTIES TO THE INITIAL ADVISORY FROM MARTIN WEST TO
OWSLEY COUNTY. OTHERWISE...THE FORECAST IS ON TRACK WITH BETWEEN 1
AND 2 INCHES OF ACCUMULATION POSSIBLE MOST PLACES IN THE
ADVISORY...A BIT LESS IN THE WEST AND NORTH WITH HIGHER AMOUNTS
CLOSER TO THE VIRGINIA BORDER...PARTICULARLY FOR ELEVATIONS ABOVE
2500 FEET.
THE SNOW WILL TAPER TO FLURRIES AND POSSIBLE END FOR A TIME OVER
MOST OF THE AREA BY MIDDAY THURSDAY BEFORE THE APPROACH OF THAT
NEXT MID LEVEL TROUGH AND A SFC ARCTIC FRONT. SIMILAR TO SOME OF
THE FRONTS WE HAVE SEEN SO FAR THIS WINTER...WE EXPECT SNOW SHOWER
DEVELOPMENT ALONG AND BEHIND IT INTO THE NIGHT THURSDAY WITH BEST
LIFT AND FORCING TAKING PLACE IN THE EVENING. UP TO AN INCH OF
ADDITIONAL ACCUMULATION WILL BE POSSIBLE FROM THIS SET UP...BUT
MOST PLACES WILL SEE JUST A DUSTING OR TWO OF ACCUMULATION. ARCTIC
TEMPERATURES WILL SEND READINGS INTO THE TEENS MOST PLACES BY
FRIDAY MORNING.
USED THE CONSSHORT TO JUMP START THE T/TD/WIND GRIDS THROUGH THE
DAY THURSDAY...WITH SOME TERRAIN BASED ADJUSTMENTS. AFTER THAT
FAVORED THE SUPERBLEND INTO FRIDAY MORNING FOR A STARTING POINT.
AS FOR POPS...ENDED UP ON THE HIGH SIDE OF GUIDANCE THROUGH THE
PERIOD.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 345 PM EST WED FEB 25 2015
BROAD MID AND UPPER LEVEL TROUGH ACROSS THE ENTIRE CONUS WILL DEEPEN
OVER THE FAR SOUTHWEST...BAJA THROUGH THE WEEKEND PLACING OUR AREA
IN A GENERAL SOUTHWEST FLOW REGIME FOR THE BULK OF THE EXTENDED.
THIS WILL TEND TO KEEP STORM TRACKS SOMEWHAT CENTERED OVER THE OHIO
VALLEY REGION AS A SERIES OF DISTURBANCES RIDE NORTHEAST ACROSS THE
EASTERN CONUS. OVERALL IT APPEARS WE WILL BE GETTING INTO A VERY
ACTIVE WEATHER PATTERN...TYPICAL FOR THE APPROACH OF EARLY SPRING.
ACTUAL SENSIBLE WEATHER...PRECIPITATION TYPES...AMOUNTS ETC. WILL
DEPEND MORE ON EXACT TRACK OF SURFACE LOWS THROUGH THE REGION.
CONSIDERING THE CURRENT SNOWPACK ALONG WITH THE WATER CONTENT
PRESENT ACROSS A LARGE PART OF THE AREA...POTENTIAL HYDRO ISSUES
WILL NEED TO BE CONSIDERED SHOULD MUCH OF ANY PRECIPITATION WE
REALIZE THROUGH THE PERIOD FALL IN THE FORM OF RAIN.
MODEL SOLUTIONS APPEAR TO BE IN FAIRLY GOOD AGREEMENT THROUGH THE
EXTENDED. A SERIES OF STORM SYSTEMS SHOOT OUT OF THE INTER-MOUNTAIN/
SOUTH CENTRAL PLAINS AREA IN RAPID FIRE FASHION THROUGH THE PERIOD.
THE FIRST SHOULD AFFECT OUR AREA SUNDAY INTO MONDAY...THE SECOND
TUESDAY THROUGH EARLY WEDNESDAY AND THEN THE THIRD LATE WEDNESDAY
NIGHT INTO THURSDAY. ATTM MODEL CONSENSUS IS FOR SFC LOWS TO TRACK
GENERALLY TO OUR NORTHWEST...KEEPING OUR AREA IN THE WARM SECTORS OF
THESE SYSTEMS. HOWEVER...THE COLDER AIR THAT FILTERS IN BEHIND EACH
PASSING SYSTEM MAY ALLOW FOR THE A WINTRY MIX AT THE ONSET OF EACH
NEW ROUND OF WEATHER. THIS MAY BE ESPECIALLY TRUE NEXT TUESDAY
MORNING. AFTER A VERY COLD START FOR FRIDAY...EXPECT TEMPERATURES TO
GRADUALLY MODERATE TOWARDS MORE NORMAL LEVELS THROUGH THE EXTENDED
THOUGH OVERALL WE WILL REMAIN BELOW NORMS FOR THIS TIME OF THE
YEAR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 735 PM EST WED FEB 25 2015
EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE FIRST PART OF THE
TAF PERIOD. LOOK FOR HIGH CIGS TO DROP TOWARD MVFR BY 02Z IN THE
FAR SOUTH AND BETWEEN 4Z AND 8Z AT THE TAF SITES AS SNOW MOVES
INTO THE AREA FROM THE SOUTH...AS THE ATMOSPHERE SATURATES...CIGS
AND OR VIS OF IFR OR LOWER WILL BE POSSIBLE FOR A FEW HOURS.
THESE LOWER CIGS WILL ACCOMPANY THE NORTHERN FRINGE OF A
SIGNIFICANT WINTER STORM SYSTEM PASSING THROUGH THE SOUTHEAST
PARTS OF THE NATION BRINGING A PERIOD OF SNOW TO THE AREA. THE
HEAVIEST AND HARDEST OF THE SNOW SHOULD FALL SOUTHEAST OF
SME...LOZ...JKL AND SJS. SYM WILL BE LEAST AFFECTED. THE SNOW
WILL TAPER OFF AND CIGS WILL START TO IMPROVE 11Z TO 16Z. WINDS
WILL BE LIGHT AND VARIABLE THROUGH LATE EVENING FOR MOST PLACES
BEFORE SWITCHING TO THE NORTHEAST AND NORTH AT BETWEEN 5 AND 10
KTS 10Z TO 16Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR KYZ079-080-
083>088-107-109-110-112>120.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...RAY
AVIATION...JP
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1158 PM CST WED FEB 25 2015
.UPDATE...
ISSUED AT 1157 PM CST WED FEB 25 2015
SATELLITE SHOWS MID-LVL OVC HEADING SE AND THIS WILL RETARD THE
TEMP FALL THE REST OF THE NIGHT. SO LOW TEMPS WERE NUDGE UP 3-4F
AND FCST SKY COVER WAS INCREASED SUBSTANTIALLY. RADAR AND SFC OBS
SHOW FLURRY ACTIVITY DIMINISHING AND LIMITED TO MAINLY THE SE 1/4
OF THE FCST AREA. HJH DROPPED BRIEFLY TO 2.5 MI AT 1135 PM. THERE
ARE STILL SOME FLURRIES OVER THE SANDHILLS. WILL NEED TO MONITOR
FOR POTENTIAL INCLUSION INTO THE WRN PART OF THE FCST AREA
OVERNIGHT. OTHERWISE...NO CHANGES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 345 PM CST WED FEB 25 2015
LATEST RADAR SHOWS THE RAIN AND SNOW IS MOVING OUT OF THE FORECAST
AREA THIS AFTERNOON. THERE HAVE BEEN A FEW FLURRIES BEHIND THE MAIN
BAND...BUT EVEN THOSE ARE DIMINISHING THIS AFTERNOON. SURFACE
ANALYSIS HAS THE COLD FRONT ALREADY THROUGH THE FORECAST AREA AND
GUSTY NORTH WINDS ACROSS THE AREA. TEMPERATURES HAVE BEEN FALLING
FOR MUCH OF THE AREA THIS AFTERNOON.
MAIN QUESTION THIS AFTERNOON IS HOW QUICKLY THE PRECIPITATION WILL
MOVE OUT OF THE FORECAST AREA. THE RAP AND THE WRF BOTH INDICATE THE
PRECIPITATION SHOULD BE AN AFTERNOON EVENT AND BE DONE BEFORE THIS
EVENING. EVEN THE NAM AND THE GFS HAS IT ENDING BEFORE 00Z. WILL
START THE EVENING WITH A DRY FORECAST.
A SURFACE HIGH PRESSURE BUILDS IN THE DAKOTAS TONIGHT AND THURSDAY.
THIS WILL PUSH THE MOISTURE AND CLOUDS OUT OF THE AREA. SINCE THE
CENTER OF THE HIGH REMAINS TO THE NORTHEAST THROUGH THE
PERIOD...THERE WILL BE A FEW CLOUDS AROUND...BUT EXPECT CLOUDS TO
DIMINISH GRADUALLY LATE TONIGHT INTO THURSDAY.
THE COLD AIR HAS ALREADY STARTED TO MOVE INTO THE AREA THIS
AFTERNOON AND TEMPERATURES FOR MUCH OF THE AREA ARE COOLER NOW THAN
EARLIER. THE TEMPERATURES WILL CONTINUE TO PLUMMET TONIGHT WITH THE
DIMINISHING CLOUDS. THE COLD AIR REMAINS FIRMLY IN PLACE FOR
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 PM CST WED FEB 25 2015
THE FOCUS OF THE LONG TERM FORECAST CENTERS AROUND PRECIPITATION
CHANCES OVER THE WEEKEND AND BEGINNING OF THE WORK WEEK AS WELL AS
BELOW NORMAL TEMPERATURES.
HEADING INTO THE LONG TERM...A DEEP UPPER LEVEL TROUGH WILL DIG
SOUTH ACROSS THE WESTERN COAST PROVIDING OUR WINTER WEATHER FOR THE
NEXT SEVERAL DAYS. THIS TROUGH WILL ALLOW MULTIPLE DISTURBANCES TO
TREK ACROSS THE CENTRAL PLAINS...WITH THE FIRST PASSING THROUGH
DURING THE WEEKEND TIMEFRAME AND THE SECOND HITTING MONDAY INTO
TUESDAY.
BY SATURDAY MORNING THE MAIN UPPER LEVEL LOW WILL BE POSITIONED
ALONG THE CALIFORNIA NEVADA BORDER WITH THE MID LEVEL LOW SLIGHTLY
EAST. THE FIRST ROUND OF MID LEVEL WAVES WILL BEGIN TO SLIDE THROUGH
THE PLAINS BY SATURDAY MORNING AHEAD OF THE PARENT LOW SYSTEM. IN
ADDITION TO THE WAVE...WARM AIR ADVECTION ACROSS THE PLAINS WILL
FUEL PLENTY OF MID LEVEL MOISTURE ACROSS THE REGION. WHILE THE GFS
IS STRONGER THAN THE ECMWF...BOTH MODEL SOLUTIONS SUGGEST GOOD
ISENTROPIC LIFT ESPECIALLY ACROSS KANSAS THROUGH THE WEEKEND.
FINALLY...A COLD FRONT WILL SLIDE THROUGH THE AREA SUNDAY MORNING
WITH AT LEAST SOME FRONTOGENETIC LIFT ALONG ITS BOUNDARY. ALTHOUGH
THIS IS NOT A MAJOR SYNOPTIC SETUP...BUT RATHER A MINOR
WAVE...SEVERAL KEY COMPONENTS ARE COMING TOGETHER TO FORM A DECENT
CHANCE FOR SNOW SATURDAY INTO SUNDAY MORNING. WITH MODEL AGREEMENT
LEANING TOWARDS BETTER LIFT OVER KANSAS...PLACED HIGHER AMOUNTS OVER
NORTH CENTRAL KANSAS. CURRENT MODEL TRENDS INDICATE THE POTENTIAL
FOR AT LEAST A COUPLE OF INCHES OF SNOW BY THE END OF THE WEEKEND
ACROSS NORTH CENTRAL KANSAS...POSSIBLY ADVISORY CRITERIA...WITH
LESSER AMOUNTS FARTHER NORTH.
THE NEXT SYSTEM SLIDES THROUGH MONDAY INTO TUESDAY...AND IS SOMEWHAT
MORE INTRIGUING. WHILE THE MAIN UPPER LEVEL LOW SLOWLY SHIFTS ACROSS
THE ROCKY MOUNTAINS...THE MID LEVEL LOW SURGES NORTHWARD ACROSS
NORTHERN NEBRASKA AND DAKOTAS. STRONG WARM AIR ADVECTION AND
SOUTHEASTERLY WINDS WILL BRING PLENTY OF MOISTURE AGAIN TO THE
CENTRAL PLAINS. ISENTROPIC LIFT IS BETTER IN BOTH THE GFS AND ECMWF
THAN THE WEEKEND STORM. AND ANOTHER COLD FRONT WILL DRAG ACROSS THE
CWA BY TUESDAY AFTERNOON. LOOKING AT ANOTHER ROUND OF SNOW FOR THE
FORECAST AREA. AT THIS TIME...ITS TOO EARLY TO DETERMINE
AMOUNTS...BUT RIGHT NOW MODELS FOCUS HEAVIER BANDS NORTH OF
INTERSTATE 80.
COLD TEMPERATURES CONTINUE THROUGHOUT THE LONG TERM...WITH AT LEAST
TWO SHOTS OF REINFORCING COLD AIR...AND LITTLE TO ANY WARM UPS. BOTH
COLD FRONTS...SUNDAY AND TUESDAY BRING VERY COLD 850 MB AIR TO THE
REGION...THE COLDER OF THE TWO ON TUESDAY. 850 TEMPERATURES DIP TO
NEAR 15 DEGREES BELOW BY WEDNESDAY AFTER THE COLD FRONTAL PASSAGE.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z THU NIGHT)
ISSUED AT 1157 PM CST WED FEB 25 2015
REST OF TONIGHT: VARIABLE BETWEEN VFR AND MVFR...BUT TRENDING MORE
TOWARD VFR. SOME MVFR CIGS 2000-2500 FT REMAIN BUT ARE NOT SOLID.
EAR HAS A BETTER CHANCE OF OCCASIONAL MVFR CIGS THRU 09Z.
OTHERWISE VFR CIGS AROUND 10K FT. N WINDS WILL CONT GUSTING TO
NEAR 30 KTS AT TIMES. CONFIDENCE: MEDIUM
THU: SOME SCT STRATOCU MAY REMAIN THRU THE MORNING. THERE IS A LOT
OF UNCERTAINTY AS TO WHAT OCCURS WITH THE MID-LVL CIGS AROUND 10K
FT AS THE MODELS DO NOT HAVE A GOOD HANDLE VS WHAT IS ACTUALLY
OCCURRING ON SATELLITE. SO WHILE WE HAVE INDICATED SKC...WE MAY
NEED TO INCLUDE SOME SCT-BKN 10K FT CLOUDS AS WE MONITOR TRENDS.
GUSTINESS ENDS WITH N WINDS SETTLING AROUND 15 KTS. CONFIDENCE:
MEDIUM
THU EVE: VFR SKC. WINDS DECREASE BELOW 10 KTS AND SHIFT TO NE.
CONFIDENCE: MEDIUM
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...JCB
LONG TERM...SALTZMAN
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
520 PM MST FRI FEB 27 2015
.AVIATION...
00Z TAF CYCLE
MTS OBSCURED IN WDSPRD MVFR TO IFR CIGS/VSBYS IN SNOW AND FOG
ACROSS MOST OF FCST AREA OVERNIGHT AND INTO AT LEAST SAT MORN...
ALTHOUGH A MIX OF RAIN AND SNOW POSSIBLE LOWER ELEVATIONS WEST OF
A LINE FROM THE BOSQUE DEL APACHE TO THE CHUSKA MTS BEFORE 28/04Z
WHERE SOME PATCHES OF VFR CONDITIONS MAY REMAIN OVERNIGHT. SNOW TO
INCREASE A LITTLE FURTHER AT TIMES THIS EVE FROM THE CHUSKA MTS
EAST AND NORTHEAST TO THE SANGRE DE CRISTO MTS AND AS FAR SOUTH AS
CIBOLA...VALENCIA...TORRANCE AND GUADALUPE COUNTIES. PRECIP
EXPECTED TO DIMINISH SOMEWHAT OR BECOME MORE SPOTTY BETWEEN
MIDNIGHT AND DAWN. MUCH OF WESTERN...SOUTHERN AND CENTRAL NM
SHOULD IMPROVE TO VFR CONDITIONS BY LATE MORN OR EARLY AFTN WITH
TEMPS RISING WELL ABOVE FREEZING. SOME MT OBSCURATIONS MAY
CONTINUE EVEN INTO THE AFTN.
43
&&
.PREV DISCUSSION...332 PM MST FRI FEB 27 2015...
.SYNOPSIS...
AN UNSETTLED WEATHER PATTERN CONTINUES OVER NORTHERN AND CENTRAL
NEW MEXICO AS A SERIES OF STORM SYSTEMS PUSH OVER THE REGION. AS
ONE UPPER LEVEL DISTURBANCE DEPARTED THE STATE TO THE EAST THIS
MORNING...ANOTHER ONE IS CURRENTLY ARRIVING FROM THE WEST.
ADDITIONAL SNOW ACCUMULATIONS ARE EXPECTED THIS EVENING AND
OVERNIGHT...PRIMARILY IN NORTHWESTERN TO CENTRAL AND NORTH CENTRAL
PARTS OF NEW MEXICO. INTO SATURDAY AND SUNDAY...ANOTHER POTENT
DISTURBANCE WILL DIVE INTO CALIFORNIA BEFORE SLOWLY SPREADING OVER
NEW MEXICO. A PROLONGED PERIOD OF HIGH ELEVATION SNOW IS EXPECTED
OVER NORTH CENTRAL TO NORTHWESTERN NEW MEXICO
SATURDAY...SUNDAY...AND INTO MONDAY AND TUESDAY. THE HIGHEST SNOW
TOTALS WILL BE FOUND IN THE SAN JUAN OR TUSAS MOUNTAINS NEAR THE
COLORADO BORDER WHERE AN ADDITIONAL ONE TO TWO FEET OF SNOW COULD
ACCUMULATE...PRIMARILY IN THE HIGHER ELEVATIONS ABOVE EIGHT
THOUSAND FEET. RAIN WILL FALL IN LOWER ELEVATIONS DURING THIS
WEEKEND TO EARLY NEXT WEEK PERIOD.
&&
.DISCUSSION...
THE MIDDLE OF A BARRAGE OF UPPER LEVEL DISTURBANCES. NOT MUCH OF A
RESPITE OR LULL IN THE PRECIPITATION WAS OBSERVED THIS MORNING
BEFORE THE NEXT UPSTREAM SYSTEM STARTED SPREADING MORE BATCHES OF
SNOW INTO WETSERN NM. THIS LATTER DISTURBANCE IS A BIT MORE SUBTLE
LOOKING ON WATER VAPOR IMAGERY COMPARED TO ITS
PREDECESSOR...HOWEVER JET DYNAMICS ARE UNDERWAY AND STRENGTHENING
WITH LOTS OF DIVERGENCE ALOFT BEING DEPICTED BY FORECAST MODELS.
THIS SEEMS TO BE QUICKLY COMING TO FRUITION GIVEN LIGHT SNOW THAT
HAS ALREADY ENSUED AND STARTED AGAIN IN CENTRAL TO WESTERN ZONES.
FORECAST MODELS KEEP THIS DIVERGENCE ALOFT PEGGED OVER THE
NORTHWESTERN QUADRANT OF NM TONIGHT...AND QPF IS GENEROUSLY
PAINTED BENEATH. HRRR MODEL IS ALSO QUITE GENEROUS WITH THIS TREND
WITH A FEW MESOSCALE BANDS OF SNOW BEING DEPICTED. THUS...FELT
PRUDENT TO SPATIALLY AND TEMPORALLY EXTEND ADVISORIES/WARNING
WESTWARD AND LONGER RESPECTIVELY. THESE AMENDMENTS WERE MADE AT
NOON AND WILL HOLD FOR NOW.
INTO SATURDAY THE DIVERGENCE SLOWLY DECREASES IN INTENSITY OVER NM
AND THE FLOW ALOFT BEGINS BACKING MORE SOUTHWESTERLY AS A LOW
TAKES SHAPE AND DIVES INTO CA. THIS SHOULD BEGIN A REDUCTION IN
THE COVERAGE OF PRECIPITATION IN SOME LOWER ELEVATION
AREAS...REDUCTION BEING RELATIVE...WHILE OROGRAPHICS BECOME THE
MORE DOMINANT FORCING MECHANISM FOR THE HIGHER TERRAIN. ELEVATIONS
BELOW 7000 FEET WOULD ALSO OBSERVE A QUICK WARMING TREND AS WARM
AIR ADVECTION BEGINS IN THE SOUTHWESTERLY FLOW. THE FORECAST
MODELS MAY BE A BIT TOO HIGH WITH MAX TEMPERATURE GUIDANCE ON THIS
THOUGH...AS THE CLOUD COVER MAY BE SLOW TO ERODE...STUNTING THE
WARMING MORE THAN WHAT IS ADVERTISED BY MODELS. HAVE BUILT IN A
QUICK CHANGEOVER TO RAIN IN THESE LOWER ELEVATIONS BY LATE MORNING
AND INTO THE AFTERNOON...BUT THIS COULD BE A BIT PREMATURE AND
WILL NEED TO BE CLOSELY MONITORED. PRECIPITATION COULD ALSO BEGIN
TO TAKE ON A SHOWERY OR CONVECTIVE NATURE TO IT AS MODELS HAVE
LIFTED INDICES OF 0 TO -1C PROGGED OVER SOME NORTH CENTRAL TO
NORTHWESTERN ZONES SATURDAY AFTERNOON. THIS WOULD ONLY ADD TO SNOW
RATES IN THE HIGHER TERRAIN. THE WINTER HIGHLIGHTS/STATEMENTS IN
THE NORTHWESTERN ZONES DROP OFF SATURDAY MORNING...BUT MAY NEED TO
BE EXTENDED FOR AFOREMENTIONED REASONINGS.
THE PRECIPITATION REALLY FOCUSES TOWARD THE NORTHWESTERN THIRD OF
THE FORECAST AREA INTO SATURDAY NIGHT AND SUNDAY WITH FLOW
CONTINUING TO BACK SLIGHTLY MORE WHILE SPEEDS ALOFT INCREASE. THIS
WILL KEEP STEADY OROGRAPHIC FORCING OVER THE NORTH CENTRAL TO
NORTHWESTERN MOUNTAINS WITH SOME PRONOUNCED PRECIPITATION SHADOWS
DOWNWIND OR NORTHEAST OF CHUSKAS AND OTHER TOPOGRAPHICAL BARRIERS.
THE SOUTHWESTERLY FLOW ALOFT AND RISING PRESSURE HEIGHTS WILL ALSO
KEEP THE WARMER AIR ADVECTING THIS WAY...AND SATURDAY NIGHT`S LOW
TEMPERATURES WILL BE 10 TO 15 DEGREES WARMER THAN TONIGHT`S
READINGS WHILE SUNDAY`S HIGHS RISE ANOTHER 5 TO 15 DEGREES ABOVE
SATURDAY`S HIGHS. THIS WARMING TREND WILL SHIFT SNOWFALL
ACCUMULATIONS UPWARD TO 7500 TO 8500 FEET SUNDAY AFTERNOON. WHILE
THIS WILL LIMIT THE SPATIAL AREA OF SNOWFALL ACCUMULATIONS...THE
PEAKS ABOVE THIS THRESHOLD WILL STILL SEE REMARKABLE SNOW
AMOUNTS...LIKELY ONE TO THREE FEET ON MANY PEAKS ABOVE 8500 FEET
AND CLOSER TO FOUR FEET NEAR THE CO/NM BORDER ABOVE 10000 FEET.
RUNOFF AND SNOW MELT AT LOWER ELEVATIONS WILL ALSO NEED TO BE
MONITORED CLOSELY ON SUNDAY...PERHAPS CREATING HYDROLOGY ISSUES.
AND THE THREAT FOR ACCUMULATION STILL WON`T END THROUGH MONDAY AS
THE UPPER LOW ROUNDS SOUTHERN CA AND DRIVES A PACIFIC FRONT CLOSER
TO NM...EVENTUALLY CROSSING INTO OUR FORECAST AREA MONDAY NIGHT.
THIS FRONTOGENETICAL FORCING IN ITSELF WILL ALSO INDUCE A HEALTHY
SLUG OF PRECIPITATION...POSSIBLY ENHANCED BY A SUBTROPICAL
MOISTURE TAP. THEN A KICKER SHORT WAVE TROUGH WILL DIG ON THE BACK
SIDE OF THIS BEFORE TURNING INTO OLD MEXICO TUESDAY AND EARLY
WEDNESDAY. FINALLY THE CABOOSE IN THE TRAIN OF STORM SPILLS
SOUTHWARD IN STRONG MERIDIONAL FLOW ON WEDNESDAY...UNLOCKING THE
DOOR TO SOME VERY COLD CONTINENTAL POLAR AIR. ONCE THIS SYSTEM
PASSES...A WELCOME DRIER PATTERN SHOULD FOLLOW INTO THURSDAY OF
NEXT WEEK.
52
&&
.FIRE WEATHER...
AN ACTIVE WEATHER PATTERN WILL PERSIST THROUGH THE MIDDLE OF NEXT
WEEK. MOIST WESTERLY FLOW WILL CONTINUE OVER NORTHERN AND CENTRAL
NEW MEXICO TONIGHT AND SATURDAY...ALLOWING WEST FACING HIGHER
TERRAIN LOCATIONS...ESPECIALLY FROM THE WEST CENTRAL TO THE NORTH
CENTRAL...TO CONTINUE PICKING UP SNOW. THE WINDS ALOFT TRANSITION TO
SOUTHWEST SUNDAY INTO MONDAY AS AN UPPER LOW/TROUGH DIG INTO SOCAL
AND ARIZONA. TEMPERATURES WILL WARM IN ADVANCE OF THE LOW...ALLOWING
SNOW LEVELS TO GRADUALLY RISE FROM WHAT THEY ARE THIS AFTERNOON.
SOME COOLER AIR MAY ENTER THE EASTERN PLAINS SUNDAY...BOTH ECMWF AND
GFS AGREE...BUT LOOKS LIKE IT MERELY RETARDS WARMING IN THE PLAINS
FOR ANOTHER DAY RATHER THAN BRINGS ANOTHER SURGE OF MUCH COLDER AIR.
A SPLIT FLOW PATTERN DOMINATES EARLY TO MID NEXT WEEK...PERMITTING A
MUCH COLDER AND DRIER AIR MASS TO SURGE INTO THE EASTERN PLAINS
TUESDAY NIGHT/WEDNESDAY. THIS LOOKS TO BE THE LAST GASP FOR THE
ACTIVE WEATHER AT LEAST FOR THE REST OF NEXT WEEK.
THROUGH EARLY NEXT WEEK...HEAVY SNOW ACCUMULATIONS ARE LIKELY FOR
THE NORTHERN MOUNTAINS. ALTHOUGH SNOW LEVELS ARE FORECAST TO RISE
SUNDAY INTO MONDAY...SOME OF THE HIGHER NORTHERN/WESTERN TERRAIN
WILL CONTINUE TO RECEIVE SNOW...AND SNOW LEVELS OVERALL FALL AGAIN
TUESDAY AS THE UPPER LOW/TROUGH MOVE OVERHEAD AND TO OUR SOUTH.
HIGH TEMPERATURES THROUGH THE MIDDLE OF NEXT WEEK WILL REMAIN BELOW
AVERAGE. VENT RATES WILL BE POOR IN THE EAST SATURDAY AND SUNDAY BUT
GOOD TO EXCELLENT OVER MOST OF THE WEST CENTRAL AND SOUTHWEST DUE TO
INCREASING WINDS AND MIXING HEIGHTS. VENT RATES OVERALL NEXT MONDAY
AND TUESDAY WILL BE EXCELLENT THEN WORSEN SOMEWHAT WEDNESDAY.
EXCELLENT RH RECOVERIES EXPECTED THROUGH THE PERIOD ALTHOUGH MIN RH
VALUES TREND MUCH LOWER WEDNESDAY INTO THURSDAY.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 8 AM MST SATURDAY FOR THE FOLLOWING
ZONES...NMZ502>504-516-518-519-521.
WINTER WEATHER ADVISORY UNTIL 8 AM MST SATURDAY FOR THE FOLLOWING
ZONES...NMZ501-505>507-517.
WINTER STORM WARNING UNTIL 4 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ510>515-527.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
956 PM EST FRI FEB 27 2015
.SYNOPSIS...
HIGH PRESSURE WILL WEDGE DOWN THE COAST THIS WEEKEND. DRY BUT CHILLY
WEATHER IS EXPECTED ON SATURDAY. RAIN CHANCES WILL INCREASE SUNDAY
AS TEMPERATURES MODERATE. A COLD FRONT WILL CROSS THE AREA MONDAY
ACCOMPANIED BY SHOWERS. SEASONABLE WEATHER IS EXPECTED TUESDAY
BEFORE THIS FRONT LIFTS NORTH AS A WARM FRONT WEDNESDAY...BRINGING
ONE DAY OF WELL ABOVE NORMAL TEMPERATURES. ANOTHER COLD FRONT WILL
APPROACH WEDNESDAY NIGHT OR THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 945 PM FRIDAY...SUBTROPICAL JET STREAM MOISTURE CONTINUES OVER
THE COASTAL CAROLINAS...WITH UPSTREAM SATELLITE TRENDS INDICATING
THE WESTERN EDGE OF THIS CLOUD DECK MAY NOT DRIFT OFFSHORE AFTER
ALL. NORTHEAST WINDS ARE FIRMLY ESTABLISHED AT THE SURFACE...
ALTHOUGH WIND SPEEDS HAVE YET TO RAMP UP WITH THE COLD AIR SURGE
EXPECTED TO BEGIN AROUND MIDNIGHT. RECENT RUC AND HRRR MODEL TRENDS
HAVE BEEN UPWARD WITH LOW TEMPERATURES TONIGHT AND I HAVE MADE
UPWARD TWEAKS AT MOST LOCATIONS: 27-31 ACROSS SE NORTH CAROLINA AND
29-32 OVER NE SOUTH CAROLINA...WARMEST AT THE COAST. DISCUSSION FROM
630 PM FOLLOWS...
ONLY MINOR CHANGES MADE TO THE NEAR TERM FORECAST THIS EVENING. THE
LEADING EDGE OF A NE SURGE CURRENTLY DROPPING SOUTH ACROSS THE
CHESAPEAKE BAY WILL REACH OUR AREA AFTER MIDNIGHT. THE BIGGEST
QUESTION REMAINS HOW MUCH (IF ANY) LOW CLOUDINESS DEVELOPS IN THE
NORTHEASTERLY LOW-LEVEL FLOW BEHIND THE SURGE? 18Z NAM AND GFS MODEL
OUTPUT SHOW ENOUGH MOISTURE IN THE LOWEST 1000 FEET OF THE
ATMOSPHERE DEVELOPING OVERHEAD BETWEEN 09-12Z (4-7 AM) TO PRODUCE
LOW CLOUDS. A LOCAL RULE OF THUMB IS TO LOOK AT
CONVERGENCE/DIVERGENCE WITHIN THE MOISTURE-BEARING LAYER TO HELP
DIAGNOSE THE POTENTIAL FOR LOW CLOUDINESS -- AND ALL MODELS SHOW
DIVERGENCE ON THE 1000 MB SURFACE TONIGHT. FOR THIS REASON I HAVE
REDUCED THE AMOUNT OF FORECAST CLOUDINESS LATE TONIGHT...
ANTICIPATING MAINLY 300 MB CIRRUS MOISTURE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...DEVELOPING COLD WEDGE THIS WEEKEND WILL KEEP
SKIES CLOUDY AND HOLD HIGHS 10 TO 20 DEGREES BELOW CLIMO. WEAKLY
AMPLIFIED MID LEVEL PATTERN WILL CONTINUE TO PUMP MOISTURE INTO THE
SOUTHEAST. SOUTHWEST FLOW ALOFT COMBINED WITH LOW LEVEL NORTHEAST
FLOW WILL MAINTAIN WEAK ISENTROPIC LIFT FOR MUCH OF THE PERIOD BUT
LOW LEVEL DRY AIR HOLDING ON SAT AND MOST OF SAT NIGHT WILL KEEP THE
REGION DRY FOR THE FIRST HALF OF THE WEEKEND. LOW LEVELS MOISTEN UP
SUN MORNING WITH LIGHT RAIN SPREADING OVER THE AREA AS COASTAL
TROUGH DEVELOPS OFFSHORE. LATER SUN MID LEVEL RIDGE EXPANDING NORTH
FROM THE GULF OF MEXICO STARTS TO WEAKEN THE WEDGE...LESSENING
ISENTROPIC LIFT. WEDGE COMPLETELY BREAKS DOWN SUN NIGHT WITH LIGHT
WESTERLY FLOW DEVELOPING AFTER MIDNIGHT. ALTHOUGH NORTHERLY FLOW
CONTINUES AT THE SURFACE DURING SUN THERE WILL BE SOME MODEST WARM
ADVECTION JUST ABOVE THE BOUNDARY LAYER. THIS WILL HELP PUSH HIGHS
ON SUN CLOSER TO CLIMO...THOUGH TEMPS WILL ULTIMATELY FALL 5 TO 10
DEGREES SHORT. CLOUD COVER WILL HELP KEEP LOWS NEAR FREEZING SAT
NIGHT. WARM ADVECTION ALONG WITH CLOUDS WILL KEEP LOWS NEAR CLIMO
SUN NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 330 PM FRIDAY...COLD FRONT WILL MAKE ITS WAY OFF SHORE MONDAY
AS HIGH PRESSURE BUILDS DOWN FROM THE NORTHWEST TO NORTH. DEEPER
WESTERLY FLOW EARLY MONDAY WILL BECOME NW AS SHORTWAVE MOVES OFF TO
THE E-NE THROUGH LATE MONDAY. THEREFORE...INITIALLY THE DOWNSLOPE
FLOW AND SOME BREAKS OF SUNSHINE SHOULD PUSH TEMP UP AROUND 60 ON
MONDAY. BY LATER ON MONDAY A DEEPER NW FLOW WILL INCREASE CAA
BRINGING 850 TEMPS FROM CLOSE TO 10C EARLY MON DOWN TO 4 C BY TUES
MORNING. THE WINDS WILL SHIFT AROUND BECOMING MORE NORTHERLY
OVERNIGHT AND MORE ON SHORE BY TUES AFTN. INCREASING CLOUD COVER
AND WINDS MON NIGHT SHOULD KEEP TEMPS ABOVE NORMAL.
A RIDGE IN THE MID TO UPPER LEVELS WILL PUSH UP FROM THE GULF MON
NIGHT INTO TUES AND WILL SHARPEN AS TROUGH DIGS DOWN THROUGH THE MID
WEST BY WED. AT THE SAME TIME THE SFC HIGH TO THE NORTH WILL MOVE
OFF SHORE THROUGH TUES AND RIDGE TO THE SOUTH WILL HELP PUSH COLD
FRONT BACK NORTH AS WARM FRONT. A BRIEF WEDGE WILL DEVELOP WITH
INCREASING ISENTROPIC LIFT AS WARM FRONT MOVES NORTH INTO SHALLOW
RELATIVELY COOLER AIR IN PLACE ON TUES. EXPECT CLOUDS AND CHC OF PCP
ON TUES AS WARM FRONT LIFTS NORTH. WILL KEEP A LARGER TEMP RANGE IN
TIGHTENED GRADIENT BETWEEN COOL TEMPS TO THE NORTH AND WARMER TEMPS
TO THE SOUTH ON TUES BEFORE WARM FRONT LIFTS BY END OF DAY. TUES
NIGHT WILL HAVE NEAR STEADY OR RISING TEMPS IN WAA BEHIND FRONT.
COASTAL CAROLINAS WILL BE IN WARM AND MOIST AIR MASS ON WED AHEAD OF
APPROACHING COLD FRONT. TEMPS SHOULD SOAR INTO THE 70S MOST PLACES
EXCEPT CLOSER TO THE COAST WHERE COOLER OCEAN TEMPS WILL KEEP THE
AIR COOLER. ALTHOUGH CLOUDS WILL LIMIT WARMING...SOME BREAKS MAY
PUSH TEMPS HIGHER IN A FEW PLACES. ECMWF IS MUCH SLOWER WITH COLD
FRONT WHILE GFS BRINGS IT THROUGH BY MIDNIGHT WED NIGHT. FOR NOW
WILL HEDGE TOWARD SLOWER FROPA AND KEEP TEMPS WARMER WED NIGHT AND
WILL BRING FRONT THROUGH EARLIER ON THURS WITH TEMPS COOLING IN CAA
THROUGH THURS INTO FRI. IF FRONT COMES EARLIER THAN SHOWERS WILL BE
MORE WIDESPREAD ON WED AFTN AND EVENING. OVERALL EXPECT INCREASING
SHOWERS AHEAD OF FRONT. EXPECT TEMPS BELOW NORMAL AGAIN LATE THURS
INTO FRI AS COLD AND DRY HIGH PRESSURE BUILDS IN.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z SATURDAY...VFR EXPECTED THROUGH THE VALID TAF PERIOD AS
HIGH PRESSURE CONTINUES TO BUILD IN.
LATEST SATELLITE IMAGERY DEPICTS A SWATH OF HIGH CLOUDS ACROSS THE
AREA...MAINLY ALONG THE COAST. COVERAGE WILL REMAIN FEW/SCT THROUGH
THE OVERNIGHT HOURS...THUS ALLOWING FOR VFR TO PREVAIL WITH LIGHT
NORTHEAST WINDS. ON SATURDAY...EXPECT A GRADUAL TIGHTENING OF THE
PRESSURE GRADIENT WHICH WILL ALLOW FOR AN INCREASE IN NORTHEAST
WINDS...SUSTAINED AOB 15 KTS AND GUSTS UP TO AROUND 20 KTS
THROUGHOUT THE DAY. MOISTURE WITHIN THE ATMOSPHERIC COLUMN INCREASES
AS WELL AS LATEST TIME-HEIGHT ANALYSIS AND FCST SOUNDINGS ILLUSTRATE
THIS...WHICH WILL ALLOW FOR MID TO HIGH CLOUDS ON SATURDAY.
EXTENDED OUTLOOK...MVFR/IFR POSSIBLE LATE SUNDAY THROUGH TUESDAY AS
A WEDGE SETS UP. WINDY WEDNESDAY WITH POSSIBLE SHOWERS WEDNESDAY
NIGHT. OTHERWISE EXPECT VFR.
&&
.MARINE...
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 PM FRIDAY...WINDS AND SEAS ARE RAMPING UP MORE SLOWLY THAN
ANTICIPATED...DELAYING THE ONSET OF SMALL CRAFT ADVISORY CONDITIONS.
UPSTREAM OBSERVATIONS ACROSS THE OUTER BANKS AND NORTHEASTERN NORTH
CAROLINA CONTINUE TO SUPPORT THE IDEA OF STRONGER WINDS MOVING INTO
THE AREA OVER THE NEXT FEW HOURS. THERE IS LITTLE SPREAD IN MODEL
GUIDANCE LENDING HIGH CONFIDENCE THAT WE WILL EVENTUALLY SEE THESE
DETERIORATING CONDITIONS DEVELOP. DISCUSSION FROM 630 PM FOLLOWS...
NO SIGNIFICANT CHANGES ARE NEEDED TO THE FORECAST WITH THIS
EARLY-EVENING UPDATE. FORECAST WIND SPEEDS HAVE BEEN REDUCED BY 3-5
KNOTS BASED ON OBSERVATIONS THROUGH THE EVENING...WITH INCREASING
SPEEDS EXPECTED OVERNIGHT AS THE PRESSURE GRADIENT TIGHTENS UP ON
THE SOUTH EDGE OF HIGH PRESSURE.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...SURFACE HIGH WEDGING DOWN THE EAST COAST WILL
MAINTAIN A PINCHED GRADIENT OVER THE WATERS SAT AND SAT NIGHT.
NORTHEAST FLOW WILL BE SOLIDLY IN THE 20 TO 25 KT RANGE WITH SEAS 4
TO 8 FT SAT. ONLY EXCEPTION WILL BE LOCATIONS WHERE NORTHEAST FLOW
IS OFFSHORE. IN THESE LOCATIONS NEAR SHORE SEAS WILL RUN 1 TO 3 FT.
GRADIENT STARTS TO RELAX LATE SAT NIGHT AS COASTAL TROUGH TAKES
SHAPE AND HIGH STARTS TO WEAKEN. WINDS DROP UNDER 20 KT EARLY SUN
MORNING AND BY AFTERNOON WILL BE 10 KT OR LESS. REDUCTION IN
NORTHEAST FLOW WILL ALLOW SEAS TO DROP AND BY DAYBREAK SUN SEAS
SHOULD BE 3 TO 5 FT AND 2 TO 4 FT BY THE END OF THE PERIOD.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...A COLD FRONT WILL DROP TOWARDS...AND THEN
ACROSS...THE WATERS DURING MONDAY PRODUCING VARIABLE WINDS THAT WILL
VEER FROM SW EARLY MONDAY...TO NE BY TUESDAY MORNING. THE GRADIENT
REMAINS RATHER WEAK DURING THIS TIME HOWEVER...SO SPEEDS WILL BE
LESS THAN 15 KTS THROUGH THE DAY. THIS FRONT WILL STALL SOUTH OF THE
WATERS THE FIRST HALF OF TUESDAY...MAINTAINING THE NE WINDS...BEFORE
LIFTING RAPIDLY BACK NORTH AS A WARM FRONT LATE TUESDAY. WINDS WILL
AGAIN VEER THROUGH HALF THE COMPASS...BECOMING SW AND RISING TO
15-20 KTS LATE. SEAS OF 2-4 FT WILL BE COMMON MONDAY AND THE FIRST
HALF OF TUESDAY...ALTHOUGH COMPRISED BY A VARIETY OF WIND WAVES
WHICH WILL FOLLOW THE PRIMARY WIND DIRECTION. THIS WILL LIKELY
CREATE PERIODS OF CONFUSED WAVE STATES DURING MONDAY AND TUESDAY.
LATE TUESDAY SEAS BUILD TOWARDS 6 FT...AND AN SCA MAY BE REQUIRED AT
THE END OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 5 AM EST
SUNDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...RGZ
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
950 PM EST FRI FEB 27 2015
.SYNOPSIS...COLD HIGH PRESSURE OVER THE CENTRAL PLAINS WILL BUILD
INTO THE MID ATLANTIC THROUGH SATURDAY. A COLD FRONT WILL APPROACH
FROM THE NORTHWEST ON SUNDAY AND MOVE INTO THE AREA BY MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
AS OF 950 PM FRIDAY...
GOOD RADIATIONAL COOLING TO START THE NIGHT AS SKIES ARE CLEAR AND
WINDS ARE EITHER LIGHT OR CALM. REGIONAL RAOB ANALYSIS REVEALS
MODEST COLD ADVECTION IN THE LOW-LEVELS (BELOW 850MB) AS ANOTHER
1040MB HIGH IS MOVING EAST ACROSS THE MIDWEST STATES. THE NAM AND
GFS BOTH SHOW RAPID MOISTENING IN THE BOUNDARY LAYER...WITH
SATURATION REACHING UP TO AROUND -8C AND EVEN A LITTLE QPF VIA SOME
SHALLOW FGEN WITH THE INITIAL SURGE OF COLD ADVECTION.
HOWEVER...THIS IS NOT SUPPORTED BY THE LATEST RAP AND HRRR. THE
STRATUS WOULD ESSENTIALLY DEVELOP OVERHEAD...SO THE LACK OF CLOUDS
DEVELOPING UPSTREAM OVER VA ISNT MUCH HELP. THE MOST RECENT NAM AND
GFS FORECAST SOUNDS HAVE TREND SLIGHTLY WARMER IN BOUNDARY LAYER AND
SLOWER WITH THE SATURATION WHICH COULD BE AN INDICATION THAT THEY
HAVE BEEN OVERDONE. SREF MEMBERS ARE PRETTY MUCH SPLIT DOWN THE
MIDDLE. STILL EXPECT SOME STRATUS WITH THE NORTHEAST FLOW BUT MAYBE
MORE PATCHY THAT PREVIOUSLY THOUGHT. WILL LOWER LOWS A DEGREE OR
TWO BASED ON TRENDS...DIPPING TO NEAR 20 IN THE NORTHEAST AND CLOSER
TO 30 IN THE SOUTHEAST.
AS FOR BLACK ICE...DESPITE A DAY OF GOOD MELTING TODAY...THE
POTENTIAL FOR BLACK ICE TONIGHT AND SAT MORNING IS STILL THERE FOR
AREAS THAT RECEIVED THE HEAVIEST SNOW. AFTER COORDINATING WITH
OFFICIALS FROM SEVERAL OF THE HARDEST HIT COUNTIES...WE HAVE DECIDED
TO ISSUE AN ADVISORY FOR BLACK ICE FOR TONIGHT FOR OUR VA BORDER
COUNTIES...AND FOR FORSYTH EAST TO FRANKLIN. WE WILL ALSO ISSUE AN
SPS FOR THE REMAINING COUNTIES THAT GOT LESSER AMOUNTS OF SNOW TO
COVER THE MORE ISOLATED NATURE OF BLACK ICE POTENTIAL.
FOR SATURDAY...COOL HIGH PRESSURE WILL CONTINUE BUILDING SOUTH
DURING THE DAY SATURDAY...RESULTING IN FAIR WEATHER WITH BELOW-
NORMAL TEMPS. HIGHS ONLY IN THE MID 30S. LIKE TODAY...IF THERE IS
LESS CLOUD COVER THAN FORECAST...THE SUN COULD HELP WARM TEMPS
SEVERAL DEGREES HIGHER THAN FORECAST.
SATURDAY NIGHT...FLOW IN THE 925-850 MB LAYER WILL TURN TO THE SW
AND BEGIN ADVECTING MOISTURE UP INTO OUR AREA AS THE 850MB RIDGE
MOVES EAST AHEAD OF THE TROUGH MOVING ACROSS THE UPPER MISS VALLEY.
WITH THE SFC RIDGE AXIS HOLDING FIRMLY IN PLACE ACROSS OUR AREA...
THE SUBSEQUENT OVERRUNNING AND UPGLIDE WILL RESULT IN INCREASING
CLOUDS OVERNIGHT. THERE ARE VARYING SOLUTIONS RIGHT NOW REGARDING
WHEN PRECIP WILL DEVELOP ACROSS OUR AREA...BUT THE PRECIP START TIME
IS IMPORTANT BECAUSE IF IT STARTS EARLY ENOUGH...SAY A FEW HOURS
EITHER SIDE OF SUNRISE...IT MAY BE COLD ENOUGH STILL FOR A VERY
BRIEF PERIOD OF FREEZING RAIN AT THE ONSET OF PRECIP. EVEN IF THE
EARLIER SOLUTIONS WERE TO VERIFY...THE QPF DURING THAT TIME WOULD BE
VERY LIGHT...SO LITTLE IF ANY IMPACTS WOULD BE EXPECTED. IT`S
DEFINITELY WORTH KEEPING AN EYE ON. LOWS IN THE MID TO UPPER 20S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 240 PM FRIDAY...
SURFACE HIGH PRESSURE RIDGING INTO CENTRAL NC FROM THE NORTHEAST
WILL LINGER OVER THE AREA THROUGH SUNDAY...WITH CONTINUED COLD
ADVECTION AND CLOUDY SKIES. HIGHS EXPECTED TO BE MAINLY IN THE UPPER
30S NW TO MID 40S SE. THE SURFACE HIGH WILL BE SUPPRESSED TO THE
SOUTHEAST SUNDAY EVE/NIGHT AS A SURFACE LOW TRAVERSES THE GREAT
LAKES AND ITS ASSOCIATED COLD FRONT PUSHES SE TOWARD THE REGION.
RAINFALL COULD BEGIN AS EARLY AS MONDAY AFT/EVE AHEAD OF THE FRONT
AS WARM MOIST SOUTHWEST FLOW ABOVE THE SURFACE OVERRUNS THE COLD AIR
AT THE SURFACE...PARTICULARLY IN THE WESTERN PORTIONS OF THE AREA...
ALTHOUGH THE GFS IS A BIT MORE EXCITED ABOUT THAT POSSIBILITY THAN
THE ECMWF. THERE WILL HOPEFULLY BE ENOUGH WARM ADVECTION FROM THE
SOUTHWEST AHEAD OF THE FRONT TO KEEP TEMPERATURES ABOVE FREEZING...AS
A NON-DIURNAL TEMPERATURE CURVE IS ANTICIPATED FROM 18Z SUNDAY
THROUGH 00Z TUESDAY. REGARDLESS...FORECAST SOUNDINGS SHOW ENOUGH OF
A WARM NOSE ABOVE THE SURFACE AND LIMITED MOISTURE IN THE ICE
NUCLEATION REGION THAT PRECIPITATION SHOULD BE ALL LIQUID.
TEMPERATURES SHOULD RISE APPROXIMATELY 5 DEGREES OR SO OVERNIGHT
INTO THE UPPER 30S NW TO MID 40S SE BY MONDAY MORNING. BY SUNRISE
MONDAY THE COLD FRONT IS EXPECTED TO BE ON THE DOORSTEP OF CENTRAL
NC...WITH THE BEST RAINFALL CHANCES ACTUALLY ENDING WELL AHEAD OF
THE FRONT. THE MODELS SHOW THE RAINFALL ALONG THE MAIN AXIS OF THE
FRONT DISSIPATING AS IT CROSSES THE MOUNTAINS AND THE FRONT BECOMING
ORIENTED MORE WEST TO EAST THROUGH CENTRAL NC MONDAY AFT/EVE.
DIFFERENCES/UNCERTAINTY IN THE TIMING AND LOCATION OF THE FRONT AS
IT SETTLES SOUTH WILL RESULT IN A FAIRLY BIG MARGIN FOR ERROR IN THE
MAX AND MIN TEMPS AS COLD HIGH PRESSURE BUILDS IN FROM THE NORTH
BEHIND THE FRONT. FOR NOW EXPECT HIGHS AROUND 50 DEGREES NORTH TO
MID 50S SOUTH AND LOWS IN THE LOW 30S NORTH TO UPPER 30S SOUTH.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 310 PM FRIDAY...
A COLORADO LOW IS EXPECTED TO DEVELOP OVER THE MIDWEST EARLY TUESDAY
AS SURFACE HIGH PRESSURE AND NORTHWEST FLOW ALOFT LINGER OVER
CENTRAL NC. THE HIGH WILL SHIFT OFFSHORE TUESDAY AFTERNOON...WITH
WARM MOIST SOUTHERLY RETURN FLOW ADVECTING INTO THE REGION.
SUBSEQUENTLY...THE COLD FRONT WILL LIFT NORTH THROUGH THE AREA AS A
WARM FRONT...WITH THE CHANCE FOR RAIN TO ONCE AGAIN MOVE INTO THE
SOUTHWEST PORTIONS OF THE AREA TUESDAY AFT/EVE AND INTO THE
OVERNIGHT HOURS. ALTHOUGH CONFIDENCE IN TEMPERATURES IS FAIRLY LOW
AT THIS TIME...HIGHS ARE EXPECTED TO BE IN THE MID 40S TO MID 50S
FROM NW TO SE AND WILL AGAIN LIKELY BOTTOM OUT IN THE LATE EVENING
BEFORE GRADUALLY RISING OVERNIGHT TO POTENTIALLY THE LOW 50S NW TO
AROUND 60 DEGREES SE AT SUNRISE WEDNESDAY. THE MODELS STILL DIFFER
QUITE A BIT WITH REGARD TO THE TIMING OF THE FRONT...AND GIVEN THE
HABIT OF THE GFS TO BE A BIT ON THE FAST SIDE...WILL LEAN TOWARD THE
SLOWER SIDE OF THE FROPA TIMING AND THE ASSOCIATED PRE-FRONTAL
RAINFALL. THE GFS BRINGS PRE-FRONTAL CONVECTION INTO THE NW PIEDMONT
AS EARLY AS WEDNESDAY AFTERNOON...WHILE THE ECMWF HOLDS OFF UNTIL
AFTER MIDNIGHT THURSDAY. HIGHEST CHANCES WILL START AROUND 00Z
THURSDAY IN THE NW AND END AROUND 00Z FRIDAY IN THE SE AND DRYING
OUT EVERYWHERE BY FRIDAY AFTERNOON (AS OF THE LATEST RUNS). TEMPS
CONTINUE TO BE LOW CONFIDENCE AS THEY WILL DEPEND STRONGLY ON THE
TIMING OF THE FRONT...BUT WITH THAT BEING SAID HAVE HIGHS WED IN THE
UPPER 50S NW TO LOW 70S SE. LOWS WED NIGHT AND HIGHS THURSDAY
PROBABLY A BIT TOO COOL...LOW 40S NW TO AROUND 50 DEGREES SOUTH AND
UPPER AROUND 50 DEGREES NW TO UPPER 50S SE...RESPECTIVELY. EXPECT A
COOL BUT DRY PERIOD THU NIGHT INTO FRIDAY...LOWS IN THE MID 20S TO
AROUND 30 DEGREES AND HIGHS UPPER 40S TO AROUND 50 DEGREES.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 645 PM FRIDAY...
24-HR TAF PERIOD: VFR CONDITIONS WERE REPORTED EVERYWHERE AS OF 00Z
THIS EVENING. A PERIOD OF MVFR/IFR CEILINGS IS EXPECTED TO DEVELOP
IN ASSOCIATION WITH A BACKDOOR COLD FRONT PROGRESSING SOUTHWARD INTO
CENTRAL NC OVERNIGHT AS 1040-1045 MB HIGH PRESSURE BUILDS EASTWARD
FROM THE OH VALLEY INTO THE MID-ATLANTIC. WINDS WILL BECOME NORTH TO
NORTHEAST AT 10-15 KT IN THE WAKE OF THE COLD FRONT. SUB-VFR
CEILINGS ARE EXPECTED TO DISSIPATE BY OR SHORTLY AFTER SUNRISE AT
MOST TERMINALS...ASIDE FROM INT/GSO WHERE MVFR CEILINGS COULD
POTENTIALLY LINGER INTO THE AFTERNOON.
LOOKING AHEAD: ADVERSE CONDITIONS WILL LARGELY PREVAIL THROUGH MID
NEXT WEEK. IFR/LIFR CEILINGS AND LIGHT PRECIPITATION ARE EXPECTED TO
DEVELOP AROUND MIDNIGHT (05Z) SUN MORNING AND LINGER THROUGH THE DAY
SUNDAY. PRECIP THAT FALLS BETWEEN 06-15Z SUN WOULD PREDOMINATELY
FALL AS SLEET/FZRA. IMPROVEMENT TO VFR WILL BE POSSIBLE FOR A PERIOD
OF TIME MON THROUGH MON EVENING AS DRY HIGH PRESSURE PROGRESSES INTO
THE REGION IN THE WAKE OF A COLD FRONTAL PASSAGE. HOWEVER... SUB-VFR
CONDITIONS APPEAR LIKELY TO RETURN LATE MON NIGHT THROUGH WEDNESDAY
AS THE HIGH MOVES OFFSHORE IN ADVANCE OF THE NEXT LOW PRESSURE
SYSTEM DEVELOPING OVER THE CENTRAL PLAINS AND TRACKING NORTHEAST
INTO THE GREAT LAKES. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FOR
BLACK ICE FROM 9 PM THIS EVENING TO 10 AM EST SATURDAY FOR
NCZ007>011-021>026-041.
&&
$$
SYNOPSIS...RAH
NEAR TERM...RAH/BLS
SHORT TERM...KC
LONG TERM...KC
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
320 PM EST THU FEB 26 2015
.SYNOPSIS... LOW PRESSURE WILL MOVE AWAY FROM THE NORTH CAROLINA
COAST THIS EVENING. HIGH PRESSURE OVER THE CENTRAL PLAINS WILL BUILD
INTO THE MID ATLANTIC ON FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 320 PM THURSDAY...
...WINTER WEATHER ADVISORY FOR BLACK ICE IN EFFECT FROM 9PM TONIGHT
THROUGH 10 AM FRIDAY...
ANOTHER COMPLICATED FORECAST FOR TONIGHT AND INTO FRIDAY WITH LOTS
OF CONSIDERATIONS INCLUDING LOW TEMPERATURES FCST ISSUES...BLACK
ICE...FOG OR FREEZING FOG AND PERHAPS SOME SPOTTY LIGHT FREEZING
RAIN OR SNOW ACROSS THE NORTHWEST PIEDMONT.
WIDESPREAD LOW OVERCAST CONTINUES ACROSS CENTRAL NC THIS AFTERNOON
WITH JUST A FEW BREAKS ACROSS THE WESTERN PIEDMONT. WHILE SOME
ADDITIONAL BREAKS MAY DEVELOP THIS EVENING...AN APPROACHING SHEARED
SHORT WAVE TROUGH ALOFT AND SHALLOW LOW LEVEL ASCENT SHOULD WORK TO
MAINTAIN A FAIR DEGREE OF CLOUDINESS OVERNIGHT. MODEL BUFR
SOUNDINGS...ESPECIALLY THE NAM/HRRR AND RAP AGGRESSIVELY COOL THE
SURFACE AND GENERATE A NOTABLE AREA OF SHALLOW STRATUS AND/OR DENSE
FOG. NOT VERY CONFIDENT ON THE HOW THIS WILL EVOLVE AND THE DEGREE
OF FOG DEVELOPMENT GIVEN MIXED SIGNALS IN THE PATTERN. CONDITIONS AT
THE GROUND LEVEL ARE VERY MOIST WITH EITHER A FRESH SNOW COVER OF
WET SNOW OR MELT WATER OR JUST DAMP CONDITIONS FROM HEAVY RAIN LAST
NIGHT. SKIES ARE NOT EXPECTED TO CLEAR MUCH OVERNIGHT SO RADIATIONAL
CONDITIONS ARE NOT IDEAL. IN ADDITION WEAK WEAK COOL ADVECTION OVER
A SNOW PACK GENERALLY ISN`T FAVORABLE FOR FOG DEVELOPMENT. STILL SOME
FOG IS EXPECTED AND WILL BE ADDED TO THE FORECAST.
TO FURTHER COMPLICATE THINGS...THE NAM AND GFS SUGGEST SOME SPOTTY
LIGHT PRECIPITATION WILL DEVELOP OVERNIGHT IN THE TRIAD AS A WEAK
SURFACE TROUGH DROPS SOUTHEAST AND A SHEARING SHORT WAVE CROSSES THE
REGION. HIGH RES CONVECTION ALLOWING MODELS ALSO GENERATE SOME
PRECIPITATION. WHILE CONFIDENCE IS LOW...FEEL IT IS PRUDENT TO ADD A
SLIGHT CHANCE OF SOME SPOTTY FREEZING DRIZZLE. THE SATURATION IS
SHALLOW BUT MAY BE SUFFICIENTLY DEEP TO APPROACH THE ICE NUCLEATION
REGION AND WARRANT THE INCLUSION OF SOME SPOTTY LIGHT SNOW. SO WEVE
ADDED A SLIGHT CHANCE OF SOME FREEZING RAIN AND LIGHT SNOW IN THE
TRIAD TONIGHT.
LOW TEMPERATURES TONIGHT ARE ALSO PROBLEMATIC GIVEN THE NEW SNOW
COVER WHICH WOULD GENERALLY PROMOTE COOLING AND LOWER TEMPERATURES.
HIGHER RESOLUTION GUIDANCE INCLUDING THE RAP AND HRRR JUMP ALL OVER
THE LOCALIZED COOLING AND SUGGEST LOWS IN THE 10-15 RANGE ACROSS
MUCH OF THE FRESH SNOW COVER AREA. GIVEN THE AMOUNT OF CLOUD COVER
AND NON IDEAL RADIATIONAL CONDITIONS...THIS SEEMS OVERDONE. ALSO THE
RIPENESS OF THE SNOW WOULD SUGGEST A LOWER CHILLING EFFECT OF THE
SNOW COMPARED TO A NEW VIRGIN SNOW COVER. HAVE GONE WITH A FORECAST
OF LOWS RANGING FROM THE 21 TO 27 DEGREES FROM NORTHEAST TO
SOUTHWEST.
WITH THESE TEMPERATURES IN MIND...EXPECT ANY LINGERING MOISTURE ON
AREA ROADS TO REFREEZE OVERNIGHT. TEMPERATURES GENERALLY WONT FALL
BELOW FREEZING UNTIL AFTER 9PM AND EXPECT REFREEZING TO BE MOST
PROBLEMATIC AFTER MIDNIGHT.
FRIDAY SHOULD FEATURE A GOOD DEAL OF CLOUDINESS TO START.
TEMPERATURES WILL SLOWLY CLIMB TO AROUND FREEZING BY 10AM ALTHOUGH
THIS COULD BE DELAYED IF CLOUD COVER HOLDS LONGER OR LOWS TONIGHT
BOTTOM OUT EVEN FURTHER THAN FORECAST. EXPECT SOME BREAKS IN THE
CLOUDS ON FRIDAY AFTERNOON WITH HIGHS CLIMBING INTO THE UPPER 30S TO
LOWER 40S. -BLAES
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/...
AS OF 320 PM THURSDAY...
1044 HPA HIGH BUILDING ACROSS THE GREAT LAKES BEGINS RIDGING SOUTH
INTO THE AREA. IN ADDITION...A WEAK SHORT WAVE WILL BE RACING ACROSS
THE NORTHERN TIER OF THE STATE IN FAST WEST SOUTHWEST FLOW. THE
LATEST GFS AND NMM SHOW SPOTTY SHOWERS IN THE FOOTHILLS AND A FLURRY
INTO THE FAR NORTHWEST LOOKS POSSIBLE...BUT MOISTURE WILL VERY
LIMITED (PW ~0.25 IN) AND WILL MAINTAIN A DRY...BUT MOSTLY CLOUDY
FORECAST OVERNIGHT. COOL AIRMASS IN PLACE AND REINFORCED CAA
OVERNIGHT WILL PRODUCE MINS IN THE UPPER TEENS IN THE NORTHEAST...
WITH MOSTLY LOWER 20S ACROSS THE SOUTH.
CONSIDERABLE CLOUDINESS ALONG WITH DAMMING SETTLED IN PLACE SATURDAY
WILL PRODUCE ANOTHER WELL-BELOW NORMAL DAY. HIGHS IN THE 30S...FROM
LOW 30S NORTHEAST UNDER THE RIDGE AXIS...TO NEAR 40 IN THE FAR
SOUTHWEST. MINS SATURDAY NIGHT WILL BE SIMILAR TO FRIDAY
NIGHT...PERHAPS A DEGREE OR TWO LOWER IF SKIES ARE CLEAR ENOUGH TO
PROMOTE BETTER RADIATION...WITH TEENS IN THE NORTHEAST TO MOSTLY
LOWER 20S ELSEWHERE.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 PM THURSDAY...
THERE IS A LOT OF UNCERTAINTY AS TO PRECIPITATION TIMING AS SPLIT
FLOW PATTERN CONTINUES INTO NEXT WEEK. INITIAL COLD AIR DAMMING
SUNDAY WILL BE NUDGED OFFSHORE BY A NORTHERN STREAM SHORT WAVE AND
ASSOCIATED COLD FRONT WHICH WILL BE MOVING ACROSS THE AREA SUNDAY
NIGHT...WITH PRECIP AHEAD OF THE FRONT EARLY SUNDAY NIGHT SPREADING
INTO THE EAST AFTER MIDNIGHT. HIGHS SUNDAY WILL BE MOSTLY IN THE LOW
TO MID 40S. MINS WILL BE MODERATING A BIT SUNDAY NIGHT WITH HEAVIER
CLOUDINESS AND SCOURING OF THE ARCTIC AIRMASS KEEPING MINS IN THE
30S.
THE AIRMASS SETTLING IN BEHIND THE FRONT WILL BE CONSIDERABLY
MILDER...BUT THE OVERALL PATTERN CONTINUES TO FAVOR YET ANOTHER
TRANSITION TO A DAMMING SCENARIO BY TUESDAY. A BACKDOOR FRONT SAGS
SOUTH ON MONDAY...WITH GOOD CHANCES OF RAIN WHICH WOULD DAMPEN/DELAY
THE POTENTIAL WARMUP INTO MID WEEK. WILL MAINTAIN A WARMUP INTO THE
50S PRE-FROPA ON MONDAY...ALONG WITH RAIN WHICH WOULD PRODUCE AN IN-
SITU COOLOFF ON TUESDAY...WITH HIGHS IN THE MID 40S WEST TO MID 50S
EAST. PROBABILITY OF RAIN WILL REMAIN AT LEAST IN THE CHANCE
CATEGORY ON WEDNESDAY INTO THURSDAY AHEAD OF A STRONG FRONTAL SYSTEM
APPROACHING FROM THE WEST. THIS SLOW MOVING SYSTEMS TIMING IS NOT
VERY CERTAIN AT THIS TIME...BUT IT LOOKS LIKE IT WOULD BE ON
WEDNESDAY NIGHT...WITH WARM AIR ADVECTION AHEAD OF THE SYSTEM
WARMING US INTO THE 60S ON WEDNESDAY AND EVEN THURSDAY AS COLD AIR
ADVECTION IS DELAYED TIL LATE DAY. &&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 250 PM THURSDAY...
ADVERSE AVIATION CONDITIONS ARE EXPECTED THROUGH MUCH OF THE TAF
FORECAST PERIOD. WIDESPREAD MVFR CEILINGS ACROSS CENTRAL NC WITH
BKN-OVC BASES AROUND 1.5-2.0KFT ARE EXPECTED TO CONTINUE THIS
AFTERNOON AND EARLY EVENING AS A RESIDUAL MOISTURE AIR MASS
REMAINS IN PLACE. AREAS OF FOG AND LOW STRATUS ARE EXPECTED TO
DEVELOP THIS EVENING WITH THE DEGREE OF THE VISIBILITY RESTRICTION
AND CEILINGS STILL SOMEWHAT UNCERTAIN. BUT FOR FOR NOW WILL GO WITH
A FORECAST OF PREVAILING MVFR/IFR CIGS AND VSBYS TEMPORALLY FALLING
TO THE LIFR CIGS AND VSBYS LATE TONIGHT. CONDITIONS WILL GRADUALLY
IMPROVE WITH LINGERING FOG AN OVERCAST SKIES GIVING WAY TO SCT-BKN
CLOUDS WITH VFR BASES AROUND 3-3.5 KFT AROUND MIDDAY FRIDAY.
LOOKING FURTHER AHEAD...
GENERALLY FAIR WEATHER CONDITIONS ARE EXPECTED ON FRIDAY NIGHT
INTO SATURDAY NIGHT. AVIATION CONDITIONS ARE LIKELY TO DETEIORATE
ON SUNDAY WITH ADVERSE AVIATION CONDITIONS LIKELY PERSISTING INTO
MID WEEK. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 10 AM EST
FRIDAY FOR NCZ007>011-021>028-038>043-073>078-083>086-088-089.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...MLM
LONG TERM...MLM
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
933 PM CST FRI FEB 27 2015
.UPDATE...
ISSUED AT 933 PM CST FRI FEB 27 2015
A WEAK COLD FRONT IS SITUATED ALONG THE MONTANA BORDER AT 03 UTC
THIS EVENING. AHEAD OF THE FRONT SOUTHERLY FLOW CONTINUES. WITH
INCREASING MOISTURE TRANSPORT...AREAS OF MID LEVEL CLOUDS HAVE
DEVELOPED ALONG AND AHEAD OF THE FRONT AND ARE LIFTING NORTHEAST
ACROSS WESTERN AND CENTRAL NORTH DAKOTA. OVER THE FAR EAST
TEMPERATURES HAVE FALLEN TO NEAR ZERO. LATEST 02 UTC RAP SHOWS THE
STRONGER LOW LEVEL WARM ADVECTION MOVING INTO THIS AREA BY AROUND
MIDNIGHT SO THINK TEMPERATURES HERE MAY FALL A FEW DEGREES BEFORE
LEVELING OFF. IN THE WEST TEMPERATURES ARE VARYING GREATLY
DEPENDING ON WHERE THE MID LEVEL CLOUDS ARE. IN GENERAL...HAVE
LOWERED TEMPERATURES OVER THE SOUTHEAST A COUPLE OF DEGREES AND
HAVE RAISED TEMPERATURES IN THE SOUTHWEST A COUPLE OF DEGREES.
EVEN THOUGH WE ARE IN THE TEENS OUT WEST...WE SHOULD SEE SOME COLD
ADVECTION DEVELOP BEHIND THE FRONT LATE TONIGHT...DROPPING THEM
CLOSE TO FORECAST LOWS. OVERALL A TRICKY TEMPERATURE FORECAST
TONIGHT. DID BUMP UP SKY COVER A LITTLE MORE BASED ON THE
INCREASING MID LEVEL CLOUDS.
UPDATE ISSUED AT 604 PM CST FRI FEB 27 2015
NO CHANGES FOR THE EARLY EVENING UPDATE. THIN HIGH CLOUDS MOVING
IN FROM THE WEST. SHOULD SEE AN INCREASE IN CLOUDS LATER TONIGHT
AS A WEAK FRONTAL BOUNDARY MOVES INTO NORTHWEST NORTH AROUND
MIDNIGHT AND MAKING ITS WAY INTO CENTRAL NORTH DAKOTA BY SATURDAY
MORNING.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 322 PM CST FRI FEB 27 2015
SUNNY SKIES AND SOUTHERLY/SOUTHWESTERLY WINDS WILL CONTINUE
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE AFTERNOON AS
HIGH PRESSURE SHIFTS EAST OF THE REGION.
A WEAK DRY COLD FRONT IS PROGGED TO ENTER WESTERN NORTH DAKOTA
AROUND MIDNIGHT...THEN PUSH INTO CENTRAL NORTH DAKOTA BY SATURDAY
MORNING. THE ONLY NOTICEABLE IMPACT WILL BE A WIND SHIFT TO
NORTHWESTERLY IN THE WAKE OF THE FRONT. GIVEN THE WEAK NATURE OF
THE BOUNDARY...NOT MUCH WIND IS EXPECTED. TEMPERATURES WILL ONCE
AGAIN BE BELOW NORMAL...RANGING FROM THE TEENS TO 20S BY SATURDAY
AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 322 PM CST FRI FEB 27 2015
THE MAIN LONG TERM HIGHLIGHT IS ANOTHER CHUNK OF ARCTIC AIR MONDAY
NIGHT AND CONTINUING THROUGH WEDNESDAY NIGHT WITH DANGEROUS WIND
CHILL TEMPERATURES ONCE AGAIN DEVELOPING. PRECIPITATION PROSPECTS
THROUGH THE LONG TERM REMAIN REMAIN SLIM TO NONE. THE PREVIOUS
TREND OF A GRADUAL MODERATING TREND LATE IN THE EXTENDED REMAINS
ON TRACK.
FOR SATURDAY NIGHT AND SUNDAY...ANOTHER UPPER LOW SHIFTS INTO
HUDSON BAY ALLOWING THE PERSISTENT LONGWAVE TROUGH ACROSS THE
GREAT LAKES AND RESULTANT NORTHWEST FLOW INTO NORTH DAKOTA TO
PERSIST. A SHORTWAVE TROUGH WILL ROTATE AROUND THE AFOREMENTIONED
HUDSON BAY LOW SATURDAY NIGHT AND SLIDE INTO SASKATCHEWAN. THIS
WILL SUPPORT A WEAK SURFACE COLD FRONT TO PASS THROUGH FROM WEST
TO EAST...06Z SUNDAY THROUGH 00Z MONDAY. PRECIPITATION POTENTIAL
IS MEAGER...WITH WEAK/SHALLOW LIFT ALONG THE SURFACE COLD FRONTAL
AS WELL AS THE SHORTWAVE TROUGH PASSAGE. THUS ONLY EXPECT A SLIGHT
CHANCE OF SNOW SATURDAY NIGHT NORTHWEST AND FAR NORTH CENTRAL WITH
THE FRONTAL PASSAGE...FOLLOWED BY FLURRIES SUNDAY WITH THE
SHORTWAVE TROUGH.
FOR SUNDAY NIGHT AND MONDAY...A BRIEF TRANSITORY RIDGE SUNDAY
NIGHT WILL BE FOLLOWED BY A SURFACE WARM FRONTAL FRONTAL SYSTEM
THROUGH WESTERN AND CENTRAL NORTH DAKOTA MONDAY. RISING H85
TEMPERATURES AND CORRESPONDING SURFACE HIGHS WILL BRIEFLY RESULT
IN AFTERNOON HIGH TEMPERATURES IN THE 30S WEST AND SOUTH
CENTRAL...AND 20S FARTHER NORTH AND EAST. AN ARCTIC FRONT PUSHES
INTO NORTHWEST NORTH DAKOTA JUST PRIOR TO 00Z TUESDAY.
MONDAY NIGHT THROUGH WEDNESDAY NIGHT...THE AFOREMENTIONED ARCTIC
FRONT QUICKLY SWEEPS THROUGH CENTRAL NORTH DAKOTA BY 06Z TUESDAY
WITH AS A TIGHT BAROCLINIC ZONE SHIFTING THROUGH. A MINOR THREAT
FOR A BRIEF SNOWSHOWER ALONG THE FRONT AS IT SLIPS THROUGH
OTHERWISE THE MAIN HIGHLIGHT WILL BE INCREASING WINDS AND COLD AIR
ADVECTION. 6HR PRESSURE RISES OF 12MB PER GFS PUSH INTO NORTHWEST
NORTH DAKOTA BY 06Z TUESDAY...THEN WEAKEN SLIGHTLY ACROSS THE REST
OF WESTERN AND SOUTH CENTRAL NORTH DAKOTA LATE MONDAY
NIGHT/TUESDAY MORNING. GFS BUFKIT SOUNDINGS AT KDIK AND KBIS
INDICATE COLD AIR ADVECTION COMMENCING AFTER MIDNIGHT WITH THE
ONSET OF A DEEPENING MIXED LAYER. THE MAGNITUDE OF THE MIXED LAYER
WINDS ARE 30KT WITH NEAR 40KT AT THE TOP. DESPITE HIGHER MIXING
HEIGHTS DURING THE DAYLIGHT HOURS TUESDAY...WIND SPEEDS REMAIN
SIMILAR TO LATE MONDAY NIGHT. A CONSIDERATION FOR A LOW-END WIND
ADVISORY WILL BE REVISITED IN FUTURE MODEL RUNS AS WE GET CLOSER.
WITH CYCLONIC FLOW AND SUCCESSIVE SHORTWAVES TO PUSH
THROUGH...PARTLY TO MOSTLY CLOUDY CONDITIONS DOMINATE MONDAY NIGHT
THROUGH WEDNESDAY NIGHT.
IN TERMS OF TEMPERATURES...THE COLDEST CHUNK OF AIR ARRIVES LATE
TUESDAY THROUGH WEDNESDAY. THE NORTH AMERICAN ENSEMBLE FORECAST
PERCENTILE TABLE SHOWS H85 TEMPS OF -24C COVERING MOST OF WESTERN
AND CENTRAL NORTH DAKOTA TUESDAY NIGHT THROUGH WEDNESDAY. IN FACT
THE H85-H50 COLUMN ADVERTISES VALUES NEAR OR AT THE MIN WITH
RESPECT TO CLIMATOLOGY. THIS INDICATES THE ENSEMBLE IS FORECASTING
TEMPERATURES FALLING OUTSIDE THE 1979-2009 CLIMATOLOGY FOR THIS
TIME OF YEAR. NORTHWEST WINDS TUESDAY NIGHT INTO WEDNESDAY WILL
REMAIN AT 10 TO 20 MPH AS THE SURFACE HIGH STILL RESIDES OVER
WESTERN SASKATCHEWAN. WITH MIXING...IN COMBINATION WITH PARTLY TO
MOSTLY CLOUDY SKY CONDITIONS...EXPECT MINIMUM TEMPERATURES IN THE
5 BELOW TO 15 BELOW RANGE AS OPPOSED TO A POTENTIALLY COLDER
SCENARIO OTHERWISE. THE BRISK WINDS WILL HOWEVER ALLOW WIND CHILL
TEMPERATURES TO REACH THE 25F BELOW TO 39F BELOW RANGE TUESDAY
NIGHT THROUGH WEDNESDAY MORNING OVER ALL BUT THE FAR SOUTHWEST.
HIGHS WEDNESDAY WILL RANGE FROM ZERO NORTHEAST TO 15 ABOVE
SOUTHWEST.
THURSDAY THROUGH FRIDAY...SURFACE HIGH QUICKLY SLIDES THROUGH
WEDNESDAY NIGHT WITH LOW LEVEL WARM AIR ADVECTION MAKING A RETURN
12Z THURSDAY INTO FRIDAY. THIS IS A REFLECTION OF A WARM FRONTAL
PUSH THROUGH WESTERN AND CENTRAL NORTH DAKOTA THURSDAY INTO FRIDAY
MORNING...TEMPORARILY PUSHING THE MAIN BAROCLINIC ZONE INTO
SOUTHERN CANADA. HOWEVER BY FRIDAY AFTERNOON AND BEYOND...AS A
SURFACE LOW SLIDES EAST AND ALLOWS THE CLIPPER COLD FRONT TO SHIFT
THROUGH...THE BAROCLINIC ZONE WILL ADVANCE SOUTH INTO NORTH
DAKOTA. REMAINING DRY THURSDAY AND FRIDAY WITH MODERATING
TEMPERATURES. HIGHS THURSDAY WILL RANGE FROM 15F IN THE TURTLE
MOUNTAINS TO 35F IN THE SOUTHWEST. BY FRIDAY AFTERNOON...HIGHS
WILL WARM TO THE MID 20S NORTHEAST TO LOWER 40S SOUTHWEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 933 PM CST FRI FEB 27 2015
A FRONTAL BOUNDARY WILL MOVE INTO WESTERN NORTH DAKOTA LATE THIS
EVENING AND INTO CENTRAL NORTH DAKOTA BY SATURDAY MORNING. WINDS
WILL SHIFT FROM THE SOUTH AHEAD OF THE BOUNDARY TO NORTHWEST TO
NORTH BEHIND THE FRONT. INCREASING MID LEVEL MOISTURE WILL BRING
AN INCREASE IN VFR CLOUDS LATE TONIGHT AND SATURDAY. THERE IS SOME
INDICATION OF AREAS OF MVFR CLOUDS ON SATURDAY. NAM GUIDANCE LOOKS
WAY OVERDONE WITH THE LOW LEVEL MOISTURE WHILE GFS GUIDANCE MAY BE
A BIT TOO DRY. FOR NOW WILL STICK WITH INCREASING VFR CLOUDS AND
HOLD OFF ON ANY MVFR CLOUDINESS UNTIL AFTER THE 00Z MODEL GUIDANCE
ARRIVES.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...TM
LONG TERM...KS
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS TULSA OK
958 PM CST FRI FEB 27 2015
.DISCUSSION...
MOST OF THE SNOW HAS TAPERED OFF THIS EVENING BUT NOT BEFORE A
NARROW MESOSCALE BAND OF VERY HEAVY SNOW DUMPED 5-7 INCHES
NORTH AND NORTHWEST OF TULSA. THE SECOND ROUND OF PRECIPITATION IS
ALREADY UNDERWAY HOWEVER AS AREAS OF SNOW ARE DEVELOPING ACORSS
PARTS OF CENTRAL AND SOUTHERN OKLAHOMA AS WARM ADVECTION
INCREASES. THE HRRR INDICATES THESE SNOW AREAS WILL EXPAND SLOWLY
NORTH OVERNIGHT AND INTENSIFY AROUND SUNRISE. AS A RESULT...HAVE
EXPANDED AND EXTENDED THE WINTER WEATHER ADVISORY TO INCLUDE OUR
ENTIRE FORECAST AREA FROM NOW UNTIL MIDNIGHT SATURDAY NIGHT. THE
ADVISORY WILL LIKELY NEED TO BE EXTENDED INTO SUNDAY MORNING IN
SOME PLACES.
THE HEAVIEST SNOWFALL IS STILL EXPECTED TO FALL ACROSS NORTHEAST
OKLAHOMA AND FAR NORTHWEST ARKANSAS SATURDAY MORNING INTO EARLY
AFTERNOON. A CHANGEOVER TO SOME LIGHT SLEET AND EVENTUALLY LIGHT
FREEZING RAIN AND/OR FREEZING DRIZZLE WILL OCCUR FROM SOUTH TO
NORTH SATURDAY AFTERNOON AND EVENING. ALTHOUGH THE FREEZING
RAIN/DRIZZLE IS EXPECTED TO BE LIGHT...TRAVEL PROBLEMS ARE LIKELY
EVEN DOWN TO THE RED RIVER GIVEN THE VERY COLD ANTECEDENT
TEMPERATURES.
HAVE UPDATED POPS...SNOW AMOUNTS AND TEMPS TONIGHT INTO SATURDAY
BASED ON CURRENT AND EXPECTED CONDITIONS.
UPDATE ON THE WAY.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL MIDNIGHT SUNDAY FOR OKZ049-OKZ053-
OKZ054-OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-
OKZ062-OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-
OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.
AR...WINTER WEATHER ADVISORY UNTIL MIDNIGHT SUNDAY FOR ARZ001-ARZ002-
ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
SHORT TERM...06
LONG TERM....05
PLATE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
656 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE OFF THE CAROLINA COAST AND THE JET STREAM
FAVORS BROAD BUT WEAK LIFT OVER THE STATE TODAY. AN UPPER LEVEL
TROUGH WILL CROSS THE STATE TONIGHT AND EARLY ON FRIDAY. A LARGE
AREA OF HIGH PRESSURE WILL BUILD ACROSS THE AREA FOR THE FIRST
PART OF THE WEEKEND. THE PATTERN WILL THEN BECOME RATHER STORMY
WITH A FRONTAL BOUNDARY WAGGLING NORTH AND SOUTH OVER THE AREA
INTO MID WEEK.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
645 AM UPDATE...
KNOCKED POPS AND COVERAGE OF SHSN DOWN FOR THE NEXT FEW HOURS AND
HURRIED THE ENDING OF ANY SNOW FOR THE SE BY AN HOUR OR TWO. NO
CHANGES FOR THE WEST. CURRENT TEMPS MAY LEAD TO A MILDER
AFTERNOON...BUT LOTS OF CLOUDS STILL AROUND AND WILL HOLD STEADY
WITH THOSE NUMBERS FOR NOW. THE LIGHT SNOW IS RIGHT AT THE STATE
LINE...RIGHT ON TIME.
PREV...
CLOUDS LOWERING AND LIGHT SNOW GETTING CLOSER TO THE STATE FROM
THE S AND FROM THE NW...IT IS SNOWING AT KEKN AND KCAK. THE
DOUGHNUT ON THE RADAR INDICATING SNOW ALOFT SHOULD CONTINUE TO
CLOSE IN AS THE PRECIP WORKS DOWN TO THE SURFACE BY SUNRISE RIGHT
ALONG THE SRN BORDER. THE LEFT EXIT REGION OF THE 120+KT JET IS
ALSO OVERHEAD AND THE FAVORABLE LIFT COULD PRODUCE FLURRIES ACROSS
THE ENTIRE AREA THIS MORNING. GFS WET VS MOST OTHER MDLS/ENSEMBLE
MEMBERS. HRRR AND RAP KEEP THE ACCUM PRECIP TO THE FAR SE AND OVER
THE NW MTNS. NAM DOES SNEAK SOME PRECIP N OF THE BORDER...BUT QPF
REMAINS LITTLE TO NONE. SO WILL KEEP THE LIKELY POPS CONFINED TO
THE FAR SE...MAINLY SRN LANCASTER/YORK COS. THE AMOUNTS THERE WILL
BE AN INCH OR LESS...WITH A DUSTING ALL ALONG THE MD BORDER AND
IN THE LAURELS AND NW. THE WEAKNESS IN THE LIFT AND PERSISTENT
NORTHERLY FLOW TODAY WILL KEEP THE LOW LEVELS VERY DRY IN THE
CENTRAL AND NERN PARTS OF THE CWA. THEREFORE...HAVE JUST PUT IN
SOME FLURRIES THERE. THE LOW ZIPS AWAY AND ANY SNOW IN THE SE
SHOULD MOVE AWAY/STOP BEFORE NOON. THE WINDS BACK TO THE NW AND
SOME SNOW SHOWERS WILL REMAIN IN THE WRN MTNS ALL DAY. TEMPS
SHOULD MOVE ONLY A FEW DEGS UP THROUGH THE DAY.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM FRIDAY/...
THE UPPER TROUGH AXIS MOVES OVERHEAD LATE TONIGHT AND FRIDAY
MORNING. NW WINDS WILL KEEP AN UPSLOPE GOING IN THE WEST AS WELL.
THUS...SNOW SHOWERS WILL BE POSSIBLE - MAINLY IN THE WEST AND
SOUTHERN HALF OF THE AREA THRU FRIDAY MORNING...AND WILL PROBABLY
HOLD ON IN THE LAURELS THROUGH FRIDAY EVENING.
LOW TEMPS TONIGHT WILL BE ZERO TO 5 BELOW ACROSS THE NRN
MTNS...AND UPPER SINGLE DIGITS TO LOWER TEENS ELSEWHERE. FRIDAY
MAXES WILL BE IN THE SINGLE DIGITS TO L-M20S. THE LIGHT NW WIND
APPEARS LIKE IT SHOULD NOT BE HIGH ENOUGH TO MAKE DANGEROUS WIND
CHILLS WIDESPREAD ENOUGH FOR AN ADVY FRI MORNING.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDING INTO THE REGION DRIES THINGS OUT FOR EARLY
WEEKEND. AS IT MOVES TO THE ATLANTIC COAST ON SUNDAY...RETURN FLOW
SHOULD DRAW MOISTURE UP INTO THE OHIO VALLEY. MOISTURE WILL
OVERSPREAD THE OHIO VALLEY AND SLIDE ACROSS PA IN A DISORGANIZED
PRECIPITATION PATTERN. ANOTHER BLAST OF ARCTIC AIR THEN SHOVES
THAT SYSTEM OFF TO THE EAST.
AS A SOUTHWEST UPPER FLOW SETS UP NEXT WEEK...MOISTURE WILL SPREAD
TOWARD THE AREA BY LATER TUESDAY. COLD AIR IN PLACE OVER THE
RIDGE AND VALLEY REGION COULD LEAD TO THE INITIAL PRECIPITATION
SHIELD TO BE SLEET OR FREEZING RAIN. THE BULK OF THE MOISTURE DOES
APPEAR TO TRAVEL SOUTH OF PA AT THIS TIME. UNSETTLED CONDITIONS
WILL LINGER THROUGH LATE WEEK AS THE AREA WOBBLES AROUND THE ZERO
DEGREE H850 LINE..
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
A STORM SYSTEM NEAR CAPE HATTERAS EARLY THIS MORNING WILL TRACK
OUT TO SEA LATER TODAY. HRRR OUTPUT AND LATEST RADAR TRENDS
SUGGEST THE STEADIEST SNOW AND ASSOC SIG VIS REDUCTIONS WILL STAY
SOUTH OF THE AREA. HOWEVER...UPSTREAM OBS SUGGEST VIS REDUCTIONS
IN THE 3-5SM RANGE ARE POSSIBLE ACROSS SOUTHERN PA BTWN 12Z-16Z.
COASTAL STORM WILL HAVE MADE IT/S CLOSEST PASS AND WILL BE
PULLING AWAY FROM THE AREA BY ARND 16Z. FOCUS WILL THEN SHIFT
TOWARD A WEAKER LOW PRES SYSTEM LIFTING NE FROM THE OHIO VALLEY.
LATEST MDL GUIDANCE SUGGESTS THIS SYSTEM WILL SPREAD LIGHT
SNOW/SIG VIS REDUCTIONS INTO THE NW MTNS /KBFD/ BY LATE AM...THEN
THE LAUREL HIGHLANDS /KJST/ DURING THE AFTN. PREDOMINANTLY IFR
CONDS APPEAR LIKELY AT THESE LOCATIONS INTO THIS EVENING...AS THE
SLOW-MOVING LOW PRES SYSTEM AND ASSOC LIGHT SNOW MOVES THRU. A
DOWNSLOPING NNW WIND SHOULD RESULT IN SOMEWHAT MORE FAVORABLE
CONDS EAST OF THE MTNS WITH WIDESPREAD MVFR CIGS AND OCNL LGT
SNOW. HOWEVER...CAN/T RULE OUT BRIEF IFR VIS REDUCTIONS THIS
EVENING AT KUNV/KAOO.
OUTLOOK...
FRI...EARLY AM LGT SNOW/VIS REDUCTIONS POSSIBLE.
SAT...NO SIG WX EXPECTED.
SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE.
MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM.
&&
.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 25TH...IPT 18.0...MDT 20.7.
THE CURRENT RECORD COLDEST FEBRUARY..IPT 19.3...MDT 21.4 BOTH SET
IN 1934.
SO FAR...THIS MONTH IS THE THIRD COLDEST EVER AT IPT...AND FOURTH
COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...TYBURSKI
AVIATION...FITZGERALD
CLIMATE...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
646 AM EST THU FEB 26 2015
.SYNOPSIS...
VERY LIGHT SNOW IS POSSIBLE OVER THE REGION TODAY AS LOW PRESSURE
MOVES OFF THE CAROLINA COAST AND THE UPPER JET STREAM FAVORS BROAD
BUT WEAK LIFT OVER THE STATE. THE UPPER LOW WILL CROSS THE STATE
EARLY ON FRIDAY. A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS
THE AREA FOR THE FIRST PART OF THE WEEKEND. THE PATTERN WILL THEN
BECOME RATHER STORMY WITH A FRONTAL BOUNDARY WAGGLING NORTH AND
SOUTH OVER THE AREA INTO MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS LOWERING AND LIGHT SNOW GETTING CLOSER TO THE STATE FROM
THE S AND FROM THE NW...IT IS SNOWING AT KEKN AND KCAK. THE
DOUGHNUT ON THE RADAR INDICATING SNOW ALOFT SHOULD CONTINUE TO
CLOSE IN AS THE PRECIP WORKS DOWN TO THE SURFACE BY SUNRISE RIGHT
ALONG THE SRN BORDER. THE LEFT EXIT REGION OF THE 120+KT JET IS
ALSO OVERHEAD AND THE FAVORABLE LIFT COULD PRODUCE FLURRIES ACROSS
THE ENTIRE AREA THIS MORNING. GFS WET VS MOST OTHER MDLS/ENSEMBLE
MEMBERS. HRRR AND RAP KEEP THE ACCUM PRECIP TO THE FAR SE AND OVER
THE NW MTNS. NAM DOES SNEAK SOME PRECIP N OF THE BORDER...BUT QPF
REMAINS LITTLE TO NONE. SO WILL KEEP THE LIKELY POPS CONFINED TO
THE FAR SE...MAINLY SRN LANCASTER/YORK COS. THE AMOUNTS THERE WILL
BE AN INCH OR LESS...WITH A DUSTING ALL ALONG THE MD BORDER AND
IN THE LAURELS AND NW. THE WEAKNESS IN THE LIFT AND PERSISTENT
NORTHERLY FLOW TODAY WILL KEEP THE LOW LEVELS VERY DRY IN THE
CENTRAL AND NERN PARTS OF THE CWA. THEREFORE...HAVE JUST PUT IN
SOME FLURRIES THERE. THE LOW ZIPS AWAY AND ANY SNOW IN THE SE
SHOULD MOVE AWAY/STOP BEFORE NOON. THE WINDS BACK TO THE NW AND
SOME SNOW SHOWERS WILL REMAIN IN THE WRN MTNS ALL DAY. TEMPS
SHOULD MOVE ONLY A FEW DEGS UP THROUGH THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
THE UPPER TROUGH AXIS MOVES OVERHEAD LATE TONIGHT AND FRIDAY
MORNING. NW WINDS WILL KEEP AN UPSLOPE GOING IN THE WEST AS WELL.
THUS...SNOW SHOWERS WILL BE POSSIBLE - MAINLY IN THE WEST AND
SOUTHERN HALF OF THE AREA THRU FRIDAY MORNING...AND WILL PROBABLY
HOLD ON IN THE LAURELS THROUGH FRIDAY EVENING.
LOW TEMPS TONIGHT WILL BE ZERO TO 5 BELOW ACROSS THE NRN
MTNS...AND UPPER SINGLE DIGITS TO LOWER TEENS ELSEWHERE. FRIDAY
MAXES WILL BE IN THE SINGLE DIGITS TO L-M20S. THE LIGHT NW WIND
APPEARS LIKE IT SHOULD NOT BE HIGH ENOUGH TO MAKE DANGEROUS WIND
CHILLS WIDESPREAD ENOUGH FOR AN ADVY FRI MORNING.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDING INTO THE REGION DRIES THINGS OUT FOR EARLY
WEEKEND. AS IT MOVES TO THE ATLANTIC COAST ON SUNDAY...RETURN FLOW
SHOULD DRAW MOISTURE UP INTO THE OHIO VALLEY. MOISTURE WILL
OVERSPREAD THE OHIO VALLEY AND SLIDE ACROSS PA IN A DISORGANIZED
PRECIPITATION PATTERN. ANOTHER BLAST OF ARCTIC AIR THEN SHOVES
THAT SYSTEM OFF TO THE EAST.
AS A SOUTHWEST UPPER FLOW SETS UP NEXT WEEK...MOISTURE WILL SPREAD
TOWARD THE AREA BY LATER TUESDAY. COLD AIR IN PLACE OVER THE
RIDGE AND VALLEY REGION COULD LEAD TO THE INITIAL PRECIPITATION
SHIELD TO BE SLEET OR FREEZING RAIN. THE BULK OF THE MOISTURE DOES
APPEAR TO TRAVEL SOUTH OF PA AT THIS TIME. UNSETTLED CONDITIONS
WILL LINGER THROUGH LATE WEEK AS THE AREA WOBBLES AROUND THE ZERO
DEGREE H850 LINE..
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
A STORM SYSTEM NEAR CAPE HATTERAS EARLY THIS MORNING WILL TRACK
OUT TO SEA LATER TODAY. HRRR OUTPUT AND LATEST RADAR TRENDS
SUGGEST THE STEADIEST SNOW AND ASSOC SIG VIS REDUCTIONS WILL STAY
SOUTH OF THE AREA. HOWEVER...UPSTREAM OBS SUGGEST VIS REDUCTIONS
IN THE 3-5SM RANGE ARE POSSIBLE ACROSS SOUTHERN PA BTWN 12Z-16Z.
COASTAL STORM WILL HAVE MADE IT/S CLOSEST PASS AND WILL BE
PULLING AWAY FROM THE AREA BY ARND 16Z. FOCUS WILL THEN SHIFT
TOWARD A WEAKER LOW PRES SYSTEM LIFTING NE FROM THE OHIO VALLEY.
LATEST MDL GUIDANCE SUGGESTS THIS SYSTEM WILL SPREAD LIGHT
SNOW/SIG VIS REDUCTIONS INTO THE NW MTNS /KBFD/ BY LATE AM...THEN
THE LAUREL HIGHLANDS /KJST/ DURING THE AFTN. PREDOMINANTLY IFR
CONDS APPEAR LIKELY AT THESE LOCATIONS INTO THIS EVENING...AS THE
SLOW-MOVING LOW PRES SYSTEM AND ASSOC LIGHT SNOW MOVES THRU. A
DOWNSLOPING NNW WIND SHOULD RESULT IN SOMEWHAT MORE FAVORABLE
CONDS EAST OF THE MTNS WITH WIDESPREAD MVFR CIGS AND OCNL LGT
SNOW. HOWEVER...CAN/T RULE OUT BRIEF IFR VIS REDUCTIONS THIS
EVENING AT KUNV/KAOO.
OUTLOOK...
FRI...EARLY AM LGT SNOW/VIS REDUCTIONS POSSIBLE.
SAT...NO SIG WX EXPECTED.
SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE.
MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM.
&&
.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 25TH...IPT 18.0...MDT 20.7.
THE CURRENT RECORD COLDEST FEBRUARY..IPT 19.3...MDT 21.4 BOTH SET
IN 1934.
SO FAR...THIS MONTH IS THE THIRD COLDEST EVER AT IPT...AND FOURTH
COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...TYBURSKI
AVIATION...FITZGERALD
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
346 AM EST THU FEB 26 2015
.SYNOPSIS...
VERY LIGHT SNOW IS POSSIBLE OVER THE REGION TODAY AS LOW PRESSURE
MOVES OFF THE CAROLINA COAST AND THE UPPER JET STREAM FAVORS BROAD
BUT WEAK LIFT OVER THE STATE. THE UPPER LOW WILL CROSS THE STATE
EARLY ON FRIDAY. A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS
THE AREA FOR THE FIRST PART OF THE WEEKEND. THE PATTERN WILL THEN
BECOME RATHER STORMY WITH A FRONTAL BOUNDARY WAGGLING NORTH AND
SOUTH OVER THE AREA INTO MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS LOWERING AND LIGHT SNOW GETTING CLOSER TO THE STATE FROM
THE S AND FROM THE NW...IT IS SNOWING AT KEKN AND KCAK. THE
DOUGHNUT ON THE RADAR INDICATING SNOW ALOFT SHOULD CONTINUE TO
CLOSE IN AS THE PRECIP WORKS DOWN TO THE SURFACE BY SUNRISE RIGHT
ALONG THE SRN BORDER. THE LEFT EXIT REGION OF THE 120+KT JET IS
ALSO OVERHEAD AND THE FAVORABLE LIFT COULD PRODUCE FLURRIES ACROSS
THE ENTIRE AREA THIS MORNING. GFS WET VS MOST OTHER MDLS/ENSEMBLE
MEMBERS. HRRR AND RAP KEEP THE ACCUM PRECIP TO THE FAR SE AND OVER
THE NW MTNS. NAM DOES SNEAK SOME PRECIP N OF THE BORDER...BUT QPF
REMAINS LITTLE TO NONE. SO WILL KEEP THE LIKELY POPS CONFINED TO
THE FAR SE...MAINLY SRN LANCASTER/YORK COS. THE AMOUNTS THERE WILL
BE AN INCH OR LESS...WITH A DUSTING ALL ALONG THE MD BORDER AND
IN THE LAURELS AND NW. THE WEAKNESS IN THE LIFT AND PERSISTENT
NORTHERLY FLOW TODAY WILL KEEP THE LOW LEVELS VERY DRY IN THE
CENTRAL AND NERN PARTS OF THE CWA. THEREFORE...HAVE JUST PUT IN
SOME FLURRIES THERE. THE LOW ZIPS AWAY AND ANY SNOW IN THE SE
SHOULD MOVE AWAY/STOP BEFORE NOON. THE WINDS BACK TO THE NW AND
SOME SNOW SHOWERS WILL REMAIN IN THE WRN MTNS ALL DAY. TEMPS
SHOULD MOVE ONLY A FEW DEGS UP THROUGH THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
THE UPPER TROUGH AXIS MOVES OVERHEAD LATE TONIGHT AND FRIDAY
MORNING. NW WINDS WILL KEEP AN UPSLOPE GOING IN THE WEST AS WELL.
THUS...SNOW SHOWERS WILL BE POSSIBLE - MAINLY IN THE WEST AND
SOUTHERN HALF OF THE AREA THRU FRIDAY MORNING...AND WILL PROBABLY
HOLD ON IN THE LAURELS THROUGH FRIDAY EVENING.
LOW TEMPS TONIGHT WILL BE ZERO TO 5 BELOW ACROSS THE NRN
MTNS...AND UPPER SINGLE DIGITS TO LOWER TEENS ELSEWHERE. FRIDAY
MAXES WILL BE IN THE SINGLE DIGITS TO L-M20S. THE LIGHT NW WIND
APPEARS LIKE IT SHOULD NOT BE HIGH ENOUGH TO MAKE DANGEROUS WIND
CHILLS WIDESPREAD ENOUGH FOR AN ADVY FRI MORNING.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDING INTO THE REGION DRIES THINGS OUT FOR EARLY
WEEKEND. AS IT MOVES TO THE ATLANTIC COAST ON SUNDAY...RETURN FLOW
SHOULD DRAW MOISTURE UP INTO THE OHIO VALLEY. MOISTURE WILL
OVERSPREAD THE OHIO VALLEY AND SLIDE ACROSS PA IN A DISORGANIZED
PRECIPITATION PATTERN. ANOTHER BLAST OF ARCTIC AIR THEN SHOVES
THAT SYSTEM OFF TO THE EAST.
AS A SOUTHWEST UPPER FLOW SETS UP NEXT WEEK...MOISTURE WILL SPREAD
TOWARD THE AREA BY LATER TUESDAY. COLD AIR IN PLACE OVER THE
RIDGE AND VALLEY REGION COULD LEAD TO THE INITIAL PRECIPITATION
SHIELD TO BE SLEET OR FREEZING RAIN. THE BULK OF THE MOISTURE DOES
APPEAR TO TRAVEL SOUTH OF PA AT THIS TIME. UNSETTLED CONDITIONS
WILL LINGER THROUGH LATE WEEK AS THE AREA WOBBLES AROUND THE ZERO
DEGREE H850 LINE..
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
A STORM SYSTEM OVER THE CAROLINAS WILL TRACK NORTHEAST TO CAPE
HATTERAS...THEN OUT TO SEA LATER TODAY. THE NORTHERN EDGE OF IT/S
PRECIP SHEILD COULD GRAZE KLNS WITH A BRIEF PERIOD OF LGT
SNOW/LOW VSBYS BTWN 12Z-15Z BASED ON LATEST NEAR TERM MDL
GUIDANCE. CONFIDENCE ABOUT 50/50 WHETHER KLNS SEES IFR VSBYS. CHC
OF IFR VSBY AT KMDT BTWN 12Z-15Z IS EVEN LOWER...BUT NOT ZERO.
COASTAL STORM WILL HAVE MADE IT/S CLOSEST PASS AND WILL BE
PULLING AWAY FROM THE AREA BY ARND 16Z. FOCUS WILL THEN SHIFT
TOWARD A WEAKER LOW PRES SYSTEM LIFTING NE FROM THE OHIO VALLEY.
LATEST MDL GUIDANCE SUGGESTS THIS SYSTEM WILL SPREAD LIGHT
SNOW/SIG VIS REDUCTIONS INTO THE NW MTNS /KBFD/ BY LATE AM...THEN
THE LAUREL HIGHLANDS /KJST/ DURING THE AFTN. PREDOMINANTLY IFR
CONDS APPEAR LIKELY AT THESE LOCATIONS INTO THIS EVENING...AS THE
SLOW-MOVING LOW PRES SYSTEM AND ASSOC LIGHT SNOW MOVES THRU. A
DOWNSLOPING NNW WIND SHOULD RESULT IN SOMEWHAT MORE FAVORABLE
CONDS EAST OF THE MTNS WITH WIDESPREAD MVFR CIGS AND OCNL LGT
SNOW. HOWEVER...CAN/T RULE OUT BRIEF IFR VIS REDUCTIONS THIS
EVENING AT KUNV/KAOO.
OUTLOOK...
FRI...EARLY AM LGT SNOW/VIS REDUCTIONS POSSIBLE.
SAT...NO SIG WX EXPECTED.
SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE.
MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM.
&&
.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 25TH...IPT 18.0...MDT 20.7.
THE CURRENT RECORD COLDEST FEBRUARY..IPT 19.3...MDT 21.4 BOTH SET
IN 1934.
SO FAR...THIS MONTH IS THE THIRD COLDEST EVER AT IPT...AND FOURTH
COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...TYBURSKI
AVIATION...FITZGERALD
CLIMATE...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
217 AM EST THU FEB 26 2015
.SYNOPSIS...
VERY LIGHT SNOW IS POSSIBLE OVER THE REGION TODAY AS LOW PRESSURE
MOVES OFF THE CAROLINA COAST AND THE UPPER JET STREAM FAVORS BROAD
BUT WEAK LIFT OVER THE STATE. THE UPPER LOW WILL CROSS THE STATE
ON FRIDAY. A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE
AREA FOR THE FIRST PART OF THE WEEKEND. THE PATTERN WILL THEN
BECOME RATHER STORMY WITH A FRONTAL BOUNDARY WAGGLING NORTH AND
SOUTH OVER THE AREA INTO MID WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
HIGH CLOUDS NOW COVER THE AREA AND THE DOUGHNUT OF SNOW ALOFT
SHOULD SLOWLY CLOSE IN AS THE PRECIP WORKS DOWN TO THE SURFACE BY
SUNRISE RIGHT ALONG THE SRN BORDER. THE LEFT EXIT REGION OF THE
JET IS ALSO OVERHEAD AND THE FAVORABLE LIFT COULD PRODUCE FLURRIES
ACROSS THE ENTIRE AREA THIS MORNING. GFS WET VS MOST OTHER
MDLS/ENSEMBLE MEMBERS. HRRR AND RAP KEEP THE ACCUM PRECIP TO THE
FAR SE AND OVER THE NW MTNS. SO WILL KEEP THE LIKELY POPS CONFINED
TO THE FAR SE...MAINLY SRN LANCASTER/YORK COS. THE AMOUNTS THERE
WILL BE AN INCH OR LESS...WITH A DUSTING TO AN INCH IN MOST
PLACES ALONG THE MD BORDER AND IN THE LAURELS AND NW. THE WEAKNESS
IN THE LIFT AND PERSISTENT NORTHERLY FLOW TODAY WILL KEEP THE LOW
LEVELS VERY DRY IN THE CENTRAL AND NERN PARTS OF THE CWA.
THEREFORE...HAVE JUST PUT IN SOME FLURRIES THERE. THE LOW ZIPS
AWAY AND ANY SNOW IN THE SE SHOULD MOVE AWAY/STOP BY NOON. THE
WINDS BACK TO THE NW AND SOME SNOW SHOWERS WILL REMAIN IN THE WRN
MTNS ALL DAY. TEMPS SHOULD MOVE ONLY A FEW DEGS UP THROUGH THE
DAY.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/...
THE UPPER TROUGH AXIS MOVES OVERHEAD LATE TONIGHT AND FRIDAY
MORNING. NW WINDS WILL KEEP AN UPSLOPE GOING IN THE WEST AS WELL.
THUS...SNOW SHOWERS WILL BE POSSIBLE - MAINLY IN THE WEST AND
SOUTHERN HALF OF THE AREA THRU FRIDAY MORNING...AND HOLD ON IN THE
LAURELS THROUGH FRIDAY EVENING.
LOW TEMPS THURSDAY NIGHT WILL BE ZERO TO 5 BELOW ACROSS THE NRN
MTNS...AND UPPER SINGLE DIGITS TO LOWER TEENS ELSEWHERE. FRIDAY
MAXES WILL BE IN THE UPPER SINGLE DIGITS TO L-M20S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDING INTO THE REGION DRIES THINGS OUT FOR EARLY
WEEKEND. AS IT MOVES TO THE ATLANTIC COAST ON SUNDAY...RETURN FLOW
SHOULD DRAW MOISTURE UP INTO THE OHIO VALLEY. MOISTURE WILL
OVERSPREAD THE OHIO VALLEY AND SLIDE ACROSS PA IN A DISORGANIZED
PRECIPITATION PATTERN. ANOTHER BLAST OF ARCTIC AIR THEN SHOVES
THAT SYSTEM OFF TO THE EAST.
AS A SOUTHWEST UPPER FLOW SETS UP NEXT WEEK...MOISTURE WILL SPREAD
TOWARD THE AREA BY LATER TUESDAY. COLD AIR IN PLACE OVER THE
RIDGE AND VALLEY REGION COULD LEAD TO THE INITIAL PRECIPITATION
SHIELD TO BE SLEET OR FREEZING RAIN. THE BULK OF THE MOISTURE DOES
APPEAR TO TRAVEL SOUTH OF PA AT THIS TIME. UNSETTLED CONDITIONS
WILL LINGER THROUGH LATE WEEK AS THE AREA WOBBLES AROUND THE ZERO
DEGREE H850 LINE..
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
A STORM SYSTEM OVER THE CAROLINAS WILL TRACK NORTHEAST TO CAPE
HATTERAS...THEN OUT TO SEA LATER TODAY. THE NORTHERN EDGE OF IT/S
PRECIP SHEILD COULD GRAZE KLNS WITH A BRIEF PERIOD OF LGT
SNOW/LOW VSBYS BTWN 12Z-15Z BASED ON LATEST NEAR TERM MDL
GUIDANCE. CONFIDENCE ABOUT 50/50 WHETHER KLNS SEES IFR VSBYS. CHC
OF IFR VSBY AT KMDT BTWN 12Z-15Z IS EVEN LOWER...BUT NOT ZERO.
COASTAL STORM WILL HAVE MADE IT/S CLOSEST PASS AND WILL BE
PULLING AWAY FROM THE AREA BY ARND 16Z. FOCUS WILL THEN SHIFT
TOWARD A WEAKER LOW PRES SYSTEM LIFTING NE FROM THE OHIO VALLEY.
LATEST MDL GUIDANCE SUGGESTS THIS SYSTEM WILL SPREAD LIGHT
SNOW/SIG VIS REDUCTIONS INTO THE NW MTNS /KBFD/ BY LATE AM...THEN
THE LAUREL HIGHLANDS /KJST/ DURING THE AFTN. PREDOMINANTLY IFR
CONDS APPEAR LIKELY AT THESE LOCATIONS INTO THIS EVENING...AS THE
SLOW-MOVING LOW PRES SYSTEM AND ASSOC LIGHT SNOW MOVES THRU. A
DOWNSLOPING NNW WIND SHOULD RESULT IN SOMEWHAT MORE FAVORABLE
CONDS EAST OF THE MTNS WITH WIDESPREAD MVFR CIGS AND OCNL LGT
SNOW. HOWEVER...CAN/T RULE OUT BRIEF IFR VIS REDUCTIONS THIS
EVENING AT KUNV/KAOO.
OUTLOOK...
FRI...EARLY AM LGT SNOW/VIS REDUCTIONS POSSIBLE.
SAT...NO SIG WX EXPECTED.
SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE.
MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM.
&&
.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 24TH...IPT 18.4...MDT 21.2.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO
SHORT TERM...LAMBERT
LONG TERM...TYBURSKI
AVIATION...FITZGERALD
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
145 AM EST THU FEB 26 2015
.SYNOPSIS...
VERY LIGHT SNOW IS POSSIBLE OVER THE REGION TODAY AS LOW PRESSURE
MOVES OFF THE CAROLINA COAST AND THE UPPER JET STREAM FAVORS BROAD
BUT WEAK LIFT OVER THE STATE. THE UPPER LOW WILL CROSS THE STATE
ON FRIDAY. A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE
AREA FOR THE FIRST PART OF THE WEEKEND. THE PATTERN WILL THEN
BECOME RATHER STORMY WITH A FRONTAL BOUNDARY WAGGLING NORTH AND
SOUTH OVER THE AREA INTO MID WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
HIGH CLOUDS NOW COVER THE AREA AND THE DOUGHNUT OF SNOW ALOFT
SHOULD SLOWLY CLOSE IN AS THE PRECIP WORKS DOWN TO THE SURFACE BY
SUNRISE RIGHT ALONG THE SRN BORDER. THE LEFT EXIT REGION OF THE
JET IS ALSO OVERHEAD AND THE FAVORABLE LIFT COULD PRODUCE FLURRIES
ACROSS THE ENTIRE AREA THIS MORNING. GFS WET VS MOST OTHER
MDLS/ENSEMBLE MEMBERS. HRRR AND RAP KEEP THE ACCUM PRECIP TO THE
FAR SE AND OVER THE NW MTNS. SO WILL KEEP THE LIKELY POPS CONFINED
TO THE FAR SE...MAINLY SRN LANCASTER/YORK COS. THE AMOUNTS THERE
WILL BE AN INCH OR LESS...WITH A DUSTING TO AN INCH IN MOST
PLACES ALONG THE MD BORDER AND IN THE LAURELS AND NW. THE WEAKNESS
IN THE LIFT AND PERSISTENT NORTHERLY FLOW TODAY WILL KEEP THE LOW
LEVELS VERY DRY IN THE CENTRAL AND NERN PARTS OF THE CWA.
THEREFORE...HAVE JUST PUT IN SOME FLURRIES THERE. THE LOW ZIPS
AWAY AND ANY SNOW IN THE SE SHOULD MOVE AWAY/STOP BY NOON. THE
WINDS BACK TO THE NW AND SOME SNOW SHOWERS WILL REMAIN IN THE WRN
MTNS ALL DAY. TEMPS SHOULD MOVE ONLY A FEW DEGS UP THROUGH THE
DAY.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/...
THE UPPER TROUGH AXIS MOVES OVERHEAD LATE TONIGHT AND FRIDAY
MORNING. NW WINDS WILL KEEP AN UPSLOPE GOING IN THE WEST AS WELL.
THUS...SNOW SHOWERS WILL BE POSSIBLE - MAINLY IN THE WEST AND
SOUTHERN HALF OF THE AREA THRU FRIDAY MORNING...AND HOLD ON IN THE
LAURELS THROUGH FRIDAY EVENING.
LOW TEMPS THURSDAY NIGHT WILL BE ZERO TO 5 BELOW ACROSS THE NRN
MTNS...AND UPPER SINGLE DIGITS TO LOWER TEENS ELSEWHERE. FRIDAY
MAXES WILL BE IN THE UPPER SINGLE DIGITS TO L-M20S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDING INTO THE REGION DRIES THINGS OUT FOR EARLY
WEEKEND. AS IT MOVES TO THE ATLANTIC COAST ON SUNDAY...RETURN FLOW
SHOULD DRAW MOISTURE UP INTO THE OHIO VALLEY. MOISTURE WILL
OVERSPREAD THE OHIO VALLEY AND SLIDE ACROSS PA IN A DISORGANIZED
PRECIPITATION PATTERN. ANOTHER BLAST OF ARCTIC AIR THEN SHOVES
THAT SYSTEM OFF TO THE EAST.
AS A SOUTHWEST UPPER FLOW SETS UP NEXT WEEK...MOISTURE WILL SPREAD
TOWARD THE AREA BY LATER TUESDAY. COLD AIR IN PLACE OVER THE
RIDGE AND VALLEY REGION COULD LEAD TO THE INITIAL PRECIPITATION
SHIELD TO BE SLEET OR FREEZING RAIN. THE BULK OF THE MOISTURE DOES
APPEAR TO TRAVEL SOUTH OF PA AT THIS TIME. UNSETTLED CONDITIONS
WILL LINGER THROUGH LATE WEEK AS THE AREA WOBBLES AROUND THE ZERO
DEGREE H850 LINE..
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
ARCTIC COLD FRONT WILL MOVE EAST OF THE AIRSPACE LATER THIS
EVENING. LACK OF SFC CONVERGENCE ALONG AND AHEAD OF THE FRONT HAS
HELPED TO ERODE PRACTICALLY ALL OF THE PREVIOUS...SHALLOW STRATO
CU CLOUDS.
THIN SCT CIRRUS WILL GRADUALLY THICKEN UP AND LOWER FROM SW TO NE
OVERNIGHT...BUT CONDITIONS WILL STAY VFR FOR MOST OF THE
OVERNIGHT. THE LONE EXCEPTION MAY BE AT KJST THAT COULD DIP TO
MVFR CIGS AROUND DAYBREAK THURSDAY.
MDT STRONG NW WINDS WITH THE FRONT WILL BE DECREASING AND VEERING
AROUND THROUGH THE NORTH TONIGHT...THEN TO THE NORTHEAST BY
DAYBREAK THURSDAY.
ISOLATED TO SCATTERED SNOW SHOWERS EXPECTED FOR THURSDAY...WITH
CLOUD BASES MAINLY AOA 4KFT AGL. AREAS OF MVFR CIGS AND VSBYS IN
MORE FREQUENT SNOW SHOWERS EXPECTED AT KJST AND KBFD.
OUTLOOK...
THU NIGHT...AREAS OF MVFR /MAINLY ACROSS THE NRN AND WRN MTNS/ SCTD
SNOW SHOWERS.
FRI...MAINLY DRY WITH VFR CONDITIONS.
SAT...DRY WEATHER EXPECTED WITH VFR CONDITIONS.
SUN...VFR CONDITIONS EARLY...THEN A CHANCE OF
MIXED PRECIPITATION LATE.
MON...WINTRY PCPN PSBL WITH REDUCTIONS...IMPROVING CONDS LATE.
&&
.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 24TH...IPT 18.4...MDT 21.2.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO
SHORT TERM...LAMBERT
LONG TERM...TYBURSKI
AVIATION...LAMBERT/GARTNER
CLIMATE...
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1200 PM CST THU FEB 26 2015
.AVIATION...
A COLD FRONT ALONG A K6R6 TO KECU TO KAUS TO KRWV LINE AT 17Z WILL
MOVE STEADILY SOUTH ACROSS THE REMAINDER OF SOUTH CENTRAL TEXAS
THIS AFTERNOON. VFR SKIES WILL PRECEDE THE FRONTAL PASSAGE...THEN
WITHIN AN HOUR OR TWO OF PASSAGE...LOW END MVFR CIGS WILL MOVE IN
FROM THE NORTH. HAD EARLIER EXPECTED THE MVFR CIGS TO BREAK UP TO
FEW-SCT STRATUS THIS EVENING INTO THE OVERNIGHT HOURS. NOW EXPECT
MVFR CIGS TO HOLD THROUGH TONIGHT INTO FRIDAY AS WEAK ISENTROPIC
LIFT DEVELOPS OVERNIGHT OVER THE COLD LOWER LEVELS. BY MORNING
THERE MAY BE ENOUGH MOISTURE FOR A MIX OF -RA/DZ/FZDZ/SN AND IFR
CIGS FRIDAY. HOWEVER...CHANCES ARE TOO LOW TO MENTION AT ANY TAF
SITE AND WILL MONITOR RADAR TRENDS FOR POSSIBLE LATER MENTION.
ELY WINDS AT 5 TO 10 KTS WILL PRECEDE THE FRONT...THEN SHIFT TO
NLY AND INCREASE TO 10 TO 20 KTS WITH GUSTS TO 28 KTS AS HIGH
PRESSURE BUILDS INTO THE AREA. OVERNIGHT INTO FRIDAY...WINDS WILL
DECREASE TO 6 TO 12 KTS WHILE TURNING MORE NELY MOST AREAS AND ELY
ALONG THE RIO GRANDE.
&&
.PREV DISCUSSION... /ISSUED 506 AM CST THU FEB 26 2015/
AVIATION...
AT 5 AM...THE COLD FRONT WAS LOCATED NEAR A SAN ANGELO TO DALLAS
LINE AND IS QUICKLY MOVING SOUTH. THE FRONT SHOULD BE THROUGH
KAUS/KDRT AROUND 17Z AND THOUGH THE SAN ANTONIO SITES SHORTLY
AFTER. THERE IS A NARROW BAND OF MVFR CEILINGS JUST BEHIND THE
FRONTAL BOUNDARY AND WILL SHOW A FEW HOURS OF POST FRONTAL MVFR
IN THE I-35 TAF SITES. THE FRONT WILL ALSO BRING BREEZY NORTH
WINDS WITH GUSTS UP TO 25 KNOTS EXPECTED THIS AFTERNOON. VFR WILL
PREVAIL BY LATE AFTERNOON BUT A RETURN TO MVFR IS EXPECTED AFTER
12Z TOMORROW AS LOW-LEVEL MOISTURE INCREASES ACROSS THE REGION.
PRECIPITATION CHANCES IN THE EXTENDED PORTION OF TAF AUS AND
TAFSAT ARE TOO LOW TO MENTION AT THIS TIME.
HAMPSHIRE
PREV DISCUSSION... /ISSUED 415 AM CST THU FEB 26 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
A FEW HIGHLIGHTS IN THE SHORT TERM INCLUDE A STRONG ARCTIC FRONTAL
PASSAGE TODAY AND THE POSSIBILITY OF LIGHT WINTER PRECIPITATION ON
FRIDAY.
WATER VAPOR CHANNELS AND RAP ANALYSIS DEPICT THE BASE OF A S/WV
TROUGH AXIS PIVOTING ACROSS TEXAS THIS MORNING. THIS TROUGH...IN
CONJUNCTION WITH A STRONG SURFACE HIGH OVER THE NORTHERN PLAINS
WILL DRIVE A SUBSTANTIALLY COLD AIR MASS THROUGH THE REGION STARTING
LATE MORNING INTO THE AFTERNOON WITH MORE CLOUDS. THIS COLD FRONT IS
CURRENTLY LOCATED NEAR ABILENE AS OF 10Z AND WHILE THE COLDEST AIR
WILL LAG BEHIND THE MAIN FRONT...TODAY`S HIGHS WILL BE ABOUT 10F
DEGREES COOLER THAN YESTERDAY. GUSTY NORTH WINDS WILL OCCUR THROUGH
THE AFTERNOON AND THESE WERE INCREASED SLIGHTLY TOWARDS GFS LAMP
GUIDANCE. A WIDESPREAD FREEZE FOR MOST AREAS...OTHER THAN THE RIO
GRANDE VALLEY...IS EXPECTED FRIDAY MORNING WITH SOME READINGS
DIPPING TO THE MID TO UPPER 20S FOR THE HILL COUNTRY. WIND CHILLS
COULD FALL INTO THE TEENS FRIDAY MORNING.
HIGHS FRIDAY WILL STRUGGLE TO WARM...REACHING ONLY INTO THE MID 30S
IN THE HILL COUNTRY TO NEAR 40 ALONG THE 35 CORRIDOR AND MID 40S
TOWARDS THE COASTAL PLAINS. UNFORTUNATELY...IT APPEARS WEAK
ISENTROPIC UPGLIDE ALONG THE 290K LAYER WILL AID IN STEADY
MOISTENING OF THE BOUNDARY LAYER MID-MORNING INTO THE EVENING AND
THIS COULD LEAD TO SLIGHT CHANCES OF WINTER PRECIPITATION TYPES
ACROSS PORTIONS OF THE AREA BEFORE HIGHS ARE REACHED AND THEN AGAIN
OVERNIGHT INTO SATURDAY. NAM/GFS BUFR SOUNDINGS INDICATE THAT A
COMBINATION OF SLEET/RAIN AND SLEET/SNOW MIXES COULD OCCUR MAINLY
FOR THE HILL COUNTRY BUT NOT OUTSIDE THE POSSIBILITY OF THE I-35
CORRIDOR AS WELL. PRECIPITATION TOTALS ARE STILL LOW WITH ONLY A FEW
HUNDREDTHS LIKELY BUT IF CONCENTRATED ENOUGH...SOME MINOR IMPACTS
COULD OCCUR. WILL ISSUE AN SPECIAL WEATHER STATEMENT FOR THE HILL
COUNTRY AREA TO HIGHLIGHT THIS RISK. OVERALL CONFIDENCE IS MODERATE
GIVEN MODEL AGREEMENT ON VERTICAL PROFILES BUT ONE DETRACTOR OF
IMPACTS COULD BE THOSE PROFILES INDICATING A NEAR SURFACE DRY LAYER
THAT WOULD REQUIRE SOME ADIABATIC COOLING FOR PRECIPITATION TO MAKE
IT TO THE GROUND.
LONG TERM (SATURDAY THROUGH WEDNESDAY)...
HIGHLIGHTS THIS PERIOD CONTINUE TO BE THE WINTER PRECIPITATION
POSSIBILITY EARLY SATURDAY MORNING AND THEN A FOCUS ON A FRONTAL
PASSAGE TUESDAY/WEDNESDAY THAT COULD BRING A ROUND OF THUNDERSTORMS
TO THE AREA.
WEAK OVER-RUNNING OF THE SHALLOW ARCTIC AIRMASS WILL CONTINUE INTO
EARLY SATURDAY AS TEMPERATURES FALL BACK BELOW FREEZING FOR THE HILL
COUNTRY. WHILE THERE WILL BE LIMITED MOISTURE IN THE MID-LEVELS...
ENOUGH SATURATION IN THE SFC-H7 LAYER COULD BE ENOUGH FOR FREEZING
DRIZZLE/MIST. TEMPERATURES WILL WARM THROUGH THE DAY SATURDAY AS
LOW-LVL FLOW SHIFTS TO THE SOUTHEAST AND WAA COMMENCES...ENDING ANY
FURTHER WINTER PRECIP RISK.
SATURDAY AFTERNOON THROUGH NEXT TUESDAY WILL BE A WARMING TREND WITH
SOLID INCREMENTAL WARM UPS EACH DAY AS STRONGER SUBTROPICAL HIGH
PRESSURE INFLUENCES THE REGION. ABOVE NORMAL TEMPERATURES ARE
EXPECTED WITH HIGHS CLIMBING INTO THE 70S AND EVEN THE 80S BY EARLY
NEXT WEEK. CONCURRENTLY...A H5 TROUGH WILL DIG OVER CALIFORNIA AND
EVENTUALLY SWING EAST BY MID-WEEK. THERE REMAINS SOME DIFFERENCES IN
THE GFS/EC IN HANDLING THIS WAVE AND THUS THE TIMING OF THE
PACIFIC FRONT THAT SHOULD MOVE THROUGH THE REGION ON TUESDAY BUT IT
MAY BE DELAYED UNTIL WEDNESDAY. DESPITE THE TIMING DIFFERENCES...
ADDED MOISTURE /PWATS NEAR 90TH PERCENTILE/ LEADING TO SURFACE
INSTABILITY SHOULD EQUATE TO SOME THUNDERSTORM DEVELOPMENT. ANOTHER
DEEP ARCTIC PLUNGE LOOKS TO OCCUR THURSDAY WITH BELOW NORMAL
TEMPERATURES EXPECTED BY LATE WEEK. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 49 29 40 34 47 / 10 10 20 30 40
AUSTIN BERGSTROM INTL AIRPORT 50 28 40 34 47 / 10 10 20 30 40
NEW BRAUNFELS MUNI AIRPORT 55 30 42 35 49 / 10 10 20 30 40
BURNET MUNI AIRPORT 42 26 35 29 43 / 10 10 20 30 40
DEL RIO INTL AIRPORT 62 36 42 36 50 / - 20 20 40 20
GEORGETOWN MUNI AIRPORT 46 27 38 31 46 / 10 10 20 30 40
HONDO MUNI AIRPORT 61 33 41 35 49 / - 10 20 30 30
SAN MARCOS MUNI AIRPORT 53 29 41 34 49 / 10 10 20 30 40
LA GRANGE - FAYETTE REGIONAL 54 31 46 37 53 / 10 10 20 30 40
SAN ANTONIO INTL AIRPORT 57 30 41 36 48 / 10 10 20 30 40
STINSON MUNI AIRPORT 59 33 43 36 50 / - 10 20 30 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...05
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
ISSUED BY NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
1200 PM CST Thu Feb 26 2015
.AVIATION...
/18Z TAFS/
MVFR ceilings will continue across the terminals through the
afternoon hours. Light snow will reduced visibilities across the
KABI terminal through early afternoon before tapering off. Some
improvement to ceilings is expected by early evening but
deteriorating flight conditions is expected again Friday morning
as an upper level disturbance affects the region. Light snow will
develop after 12Z across the northern terminals IFR conditions
likely at KABI due to steady/heavier snowfall. Some light frozen
precipitation is possible at the remaining terminals by mid to
late morning but confidence is not high enough to mention at this
time.
&&
.PREV DISCUSSION... /ISSUED 1022 AM CST Thu Feb 26 2015/
UPDATE...
Light snow continues to fall mainly across the Big Country this
morning and roads across the area are becoming snow covered and
slick. Latest HRRR indicates snow continuing through early
afternoon before tapering off. Have issued a Winter Weather
Advisory for the Big Country through 19Z today, with 1 to 3 inches
of snow is possible. Temperatures across the area will remain in
the upper 20s through early afternoon, so deteriorating road
conditions are likely.
PREV DISCUSSION... /ISSUED 528 AM CST Thu Feb 26 2015/
AVIATION...
/12Z TAFS/
Strong gusty north wind and lowering ceilings to MVFR are expected
behind a strong cold front this morning. Light rain at KABI will
transition to light snow mid morning. KABI will see the strongest
wind gusts up to 33 KTS this morning. Winds will gradually
decrease this afternoon. MVFR ceilings will return tonight over
most TAF sites, mainly after midnight.
PREV DISCUSSION... /ISSUED 433 AM CST Thu Feb 26 2015/
SHORT TERM...
(Today and Tonight)
Cold front was just south of I-20 from Big Spring to Abilene at 3
AM. There was a pre-frontal trough ahead of it, with north winds of
5 to 10 mph. Winds were north 15 to 25 mph behind it. Front should
be along a San Angelo to Brownwood line around 6 AM...and south of
I-10 by 9 AM.
A band of snow has developed in the southern Texas Panhandle down
to the Lubbock area at 3 AM, associated with an upper shortwave.
The area of snow will move east across the Big Country this
morning. It may start off as light rain, but transition to snow by
9 AM, with strong cold air advection behind the cold front.
Temperatures will not be rising much today, especially across the
Big Country, where clouds, snow, and cold air advection will keep
temperatures below freezing for much of the day. Temperatures in
the Big Country, in fact, may dip in the upper 20s mid morning,
and stay there. Snow amounts in the Big Country will be light,
perhaps 1 to 2 tenths, with a few flurries in the afternoon.
Tonight, the NAM model indicates an increasing potential for
light snow developing towards Friday morning, especially in the
Big Country, with increasing low mid/level lift and moisture over
the front. Have precipitation as snow, as sounding is well below
freezing and saturated up to -20 C (500MB) by Friday 6 AM CST.
04
LONG TERM...
(Friday through next Wednesday)
The challenge for the long term portion of the forecast remains
the winter weather event for the early portion of the long term,
generally Friday and Friday night.
Models are in fairly good agreement generally when it comes to
the overall pattern Friday into the weekend. A shortwave trough
will approach the area Friday morning, and move northeast away
from the area Friday night. At the surface, temperatures are not
expected to make it above freezing for most of the area Friday
through Friday night. With synoptic scale lift in the mid and
upper levels associated with the shortwave trough during the day
Friday, we should see saturation through the vertical column to
levels where snow can be efficiently produced. Therefore, have
mostly snow in the forecast Friday across the entire area. The
only exception is our far southern areas where there may be some
melting, then re-freezing taking place in the lower layers of the
atmosphere, and some sleet could develop with the snow. The path
of the shortwave is expected to be across the Texas panhandle and
caprock areas at this time. This would bring the best lift for our
area to locations mainly along and north of Interstate 20. It`s
well within the realm of possibilities that these areas could see
accumulating snowfall totals to Winter Weather Advisory criteria
(1-3") during the day Friday, with lesser amounts south of the Big
Country.
Friday night becomes more complicated. With the shortwave moving
off to the northeast, we lose our synoptic scale lift in the mid
and upper levels, meaning we will likely see some drying aloft.
However, we will still have saturated low levels (generally from
the surface through 5000 feet or so), and weak lift associated
with warm air advection over the top of the cold surface air mass.
With this in mind, we could see additional light precipitation
Friday night with temperatures still below freezing. Given that
snow production would likely end, and near surface temperatures
will be below freezing, the mostly likely precipitation for most
of the area would be freezing rain or freezing drizzle. Light ice
accumulations would be possible with this precipitation, and could
be near advisory criteria.
On Saturday, temperatures should warm to above freezing by late
morning or early afternoon for most of the area, and have brought
liquid precipitation back into the forecast for everywhere except
north of I-20 by Saturday afternoon, and even north of the I-20
will eventually turn to all liquid, but temperatures may still be
cool enough for some light freezing rain or drizzle into early
afternoon here.
Forecast looks to remain above freezing from Saturday night
through the end of the period, and models continue to hold on to a
chance for light rain or sprinkles through Tuesday, although any
precipitation we get should be very light.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 19 29 24 41 39 / 10 40 30 30 30
San Angelo 23 31 27 50 45 / 10 30 30 20 20
Junction 25 36 29 50 44 / 10 20 30 30 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 1 PM CST this afternoon FOR THE
FOLLOWING ZONES: Callahan...Fisher...Haskell...Jones...Nolan...
Shackelford...Taylor...Throckmorton.
&&
$$
99/99/99
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1022 AM CST Thu Feb 26 2015
.UPDATE...
Light snow continues to fall mainly across the Big Country this
morning and roads across the area are becoming snow covered and
slick. Latest HRRR indicates snow continuing through early
afternoon before tapering off. Have issued a Winter Weather
Advisory for the Big Country through 19Z today, with 1 to 3 inches
of snow is possible. Temperatures across the area will remain in
the upper 20s through early afternoon, so deteriorating road
conditions are likely.
&&
.PREV DISCUSSION... /ISSUED 528 AM CST Thu Feb 26 2015/
AVIATION...
/12Z TAFS/
Strong gusty north wind and lowering ceilings to MVFR are expected
behind a strong cold front this morning. Light rain at KABI will
transition to light snow mid morning. KABI will see the strongest
wind gusts up to 33 KTS this morning. Winds will gradually
decrease this afternoon. MVFR ceilings will return tonight over
most TAF sites, mainly after midnight.
PREV DISCUSSION... /ISSUED 433 AM CST Thu Feb 26 2015/
SHORT TERM...
(Today and Tonight)
Cold front was just south of I-20 from Big Spring to Abilene at 3
AM. There was a pre-frontal trough ahead of it, with north winds of
5 to 10 mph. Winds were north 15 to 25 mph behind it. Front should
be along a San Angelo to Brownwood line around 6 AM...and south of
I-10 by 9 AM.
A band of snow has developed in the southern Texas Panhandle down
to the Lubbock area at 3 AM, associated with an upper shortwave.
The area of snow will move east across the Big Country this
morning. It may start off as light rain, but transition to snow by
9 AM, with strong cold air advection behind the cold front.
Temperatures will not be rising much today, especially across the
Big Country, where clouds, snow, and cold air advection will keep
temperatures below freezing for much of the day. Temperatures in
the Big Country, in fact, may dip in the upper 20s mid morning,
and stay there. Snow amounts in the Big Country will be light,
perhaps 1 to 2 tenths, with a few flurries in the afternoon.
Tonight, the NAM model indicates an increasing potential for
light snow developing towards Friday morning, especially in the
Big Country, with increasing low mid/level lift and moisture over
the front. Have precipitation as snow, as sounding is well below
freezing and saturated up to -20 C (500MB) by Friday 6 AM CST.
04
LONG TERM...
(Friday through next Wednesday)
The challenge for the long term portion of the forecast remains
the winter weather event for the early portion of the long term,
generally Friday and Friday night.
Models are in fairly good agreement generally when it comes to
the overall pattern Friday into the weekend. A shortwave trough
will approach the area Friday morning, and move northeast away
from the area Friday night. At the surface, temperatures are not
expected to make it above freezing for most of the area Friday
through Friday night. With synoptic scale lift in the mid and
upper levels associated with the shortwave trough during the day
Friday, we should see saturation through the vertical column to
levels where snow can be efficiently produced. Therefore, have
mostly snow in the forecast Friday across the entire area. The
only exception is our far southern areas where there may be some
melting, then re-freezing taking place in the lower layers of the
atmosphere, and some sleet could develop with the snow. The path
of the shortwave is expected to be across the Texas panhandle and
caprock areas at this time. This would bring the best lift for our
area to locations mainly along and north of Interstate 20. It`s
well within the realm of possibilities that these areas could see
accumulating snowfall totals to Winter Weather Advisory criteria
(1-3") during the day Friday, with lesser amounts south of the Big
Country.
Friday night becomes more complicated. With the shortwave moving
off to the northeast, we lose our synoptic scale lift in the mid
and upper levels, meaning we will likely see some drying aloft.
However, we will still have saturated low levels (generally from
the surface through 5000 feet or so), and weak lift associated
with warm air advection over the top of the cold surface air mass.
With this in mind, we could see additional light precipitation
Friday night with temperatures still below freezing. Given that
snow production would likely end, and near surface temperatures
will be below freezing, the mostly likely precipitation for most
of the area would be freezing rain or freezing drizzle. Light ice
accumulations would be possible with this precipitation, and could
be near advisory criteria.
On Saturday, temperatures should warm to above freezing by late
morning or early afternoon for most of the area, and have brought
liquid precipitation back into the forecast for everywhere except
north of I-20 by Saturday afternoon, and even north of the I-20
will eventually turn to all liquid, but temperatures may still be
cool enough for some light freezing rain or drizzle into early
afternoon here.
Forecast looks to remain above freezing from Saturday night
through the end of the period, and models continue to hold on to a
chance for light rain or sprinkles through Tuesday, although any
precipitation we get should be very light.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 31 19 29 24 41 / 80 10 40 30 30
San Angelo 33 23 31 27 50 / 10 10 30 30 20
Junction 37 25 36 29 50 / 10 10 20 30 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 1 PM CST this afternoon FOR THE
FOLLOWING ZONES: Callahan...Fisher...Haskell...Jones...Nolan...
Shackelford...Taylor...Throckmorton.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
406 AM MST THU FEB 26 2015
.SYNOPSIS...
YET ANOTHER COOL FRONT WILL MOVE WEST THROUGH MUCH OF THE BORDERLAND
TODAY...DROPPING TEMPERATURES BACK BELOW NORMAL AND PRODUCING SOME
BREEZY WINDS. THE FRONT WILL ALSO PUSH LOWER CLOUDS INTO THE
SACRAMENTO MOUNTAINS ALONG WITH A CHANCE OF LIGHT SNOW. TEMPERATURES
WILL REMAIN COOL ON FRIDAY BEFORE AN UPPER LOW MOVES DOWN OVER
NEVADA ON SATURDAY...BRINGING SOUTHWEST FLOW AND WARMER TEMPERATURES
BACK TO THE AREA FOR SATURDAY THROUGH MONDAY. THIS SOUTHWEST FLOW
WILL ALSO BRING MOISTURE IN AND BY SATURDAY ANOTHER CHANCE OF
SHOWERS WILL DEVELOP...MOSTLY WEST OF DEMING...AND THEN SLOWLY
SPREADING EAST SUNDAY AND MONDAY. MOUNTAIN AREAS COULD RECEIVE HEAVY
SNOW MONDAY AND TUESDAY.
&&
.DISCUSSION...
LOOKS LIKE THE LATEST BACK DOOR FRONT HAS REACHED THE EAST SLOPES OF
THE SACRAMENTO MOUNTAINS A SHORT WHILE AGO ALONG WITH LOW CLOUDS.
EXPECT MOST OF THESE CLOUDS TO REMAIN ALONG AND OVER THE HIGHER
TERRAIN OF THE EASTERN CWA THIS MORNING AND AFTERNOON...WHILE THE
FRONT WILL TREK WESTWARD. HRRR SHOWS FRONT REACHING EL PASO NEXT 3-6
HOURS WITH FRONT REACHING AT LEAST THE CONTINENTAL DIVIDE BY EARLY
FRIDAY MORNING...IF NOT ALL THE WAY TO THE ARIZONA BORDER. NO OTHER
WEATHER EXPECTED WITH THIS FRONT OTHER THAN COOLER TEMPERATURES BACK
BELOW NORMAL. AS THE WEST/SOUTHWEST FLOW STRENGTHENS ACROSS THE AREA
FROM ADVANCING LOW FROM THE PAC NORTHWEST...SEVERAL DISTURBANCES
WILL PASS THROUGH TONIGHT AND FRIDAY NIGHT. LIKELY WILL NOT AFFECT
THE AREA MUCH THOUGH DID KEEP LOW POPS IN FOR THE NORTHERN TIER OF
ZONES.
DEVELOPING UPPER LOW DROPS DOWN OVER CENTRAL CALIFORNIA SATURDAY...
INCREASING THE SOUTHWEST FLOW AND MOISTURE OVER THE AREA. CHANCE OF
SHOWERS WILL SPREAD TO THE GILA SATURDAY AND SATURDAY NIGHT AND THEN
ABOUT AS FAR EAST AS DEMING SUNDAY. BY SUNDAY NIGHT OR MONDAY THE
REMAINDER OF THE CWA WILL SEE A CHANCE OF SHOWERS. SHOWERS COULD
BECOME OCCASIONALLY HEAVY SUNDAY AND MONDAY AS AIRMASS BECOMES
SLIGHTLY UNSTABLE. SNOW LEVELS WILL BEGIN QUITE HIGH SATURDAY AT
AROUND 8000-9000 FT BUT THEN BEGIN LOWERING MONDAY WITH INCOMING
PACIFIC COOL FRONT...AS LOW 5000 FT IN THE NORTH...6000-7000 FT IN
THE SOUTH. MODELS...ESPECIALLY THE GFS...CONTINUE TO SHOW HEAVY SNOW
FOR BOTH GILA/BLACK RANGE MOUNTAINS AND THE SACRAMENTO MOUNTAINS.
POTENTIAL FOR VERY HEAVY SNOW IS DEFINITELY THERE.
&&
.AVIATION...VALID 26/12Z-27/12Z...
GENLY VFR. COLD FRONT PUSHING IN FROM THE EAST WILL SPREAD LOW
CLOUDS...FOG AND POSSIBLY LIGHT SNOW TO THE SACRAMENTO MOUNTAINS
THIS MORNING AND AFTERNOON. IFR CONDS WILL DEVELOP OVER THESE
MOUNTAINS...MOST PREVALENT ON THE EAST SLOPES OF THE SACRAMENTO
MOUNTAINS. AFT 00Z...BKN120 OVC 200 WITH ISOLD -SHRA BKN080 FROM
ALM-TCS NORTH. AFT 18Z SURFACE WINDS INCREASING EAST 10-20 KTS. EAST
WINDS TO 20 KTS WITH GUSTS TO 30 KTS ALONG WEST SLOPES OF TERRAIN.
&&
.FIRE WEATHER...
ANOTHER COLD FRONT WILL MOVE IN FROM THE EAST THIS MORNING AND
AFTERNOON...SPREADING COOLER TEMPERATURES AND BRISK EAST WINDS TO
MUCH OF THE FIRE ZONES EAST OF DEMING. SOME LIGHT SNOW IS POSSIBLE
OVER THE SACRAMENTO MOUNTAINS THROUGH TONIGHT. A LARGE LOW MOVES
DOWN OVER NEVADA SATURDAY AND BRINGS BACK STRONG SOUTHWEST FLOW WITH
MOISTURE. THIS WILL CREATE BREEZY TO WINDY CONDITIONS FROM SATURDAY
INTO THE FIRST HALF OF NEXT WEEK. THE SOUTHWEST FLOW WILL ALSO BRING
MOISTURE UP...WITH SHOWERS DEVELOPING WESTERN ZONES SATURDAY AND
SPREADING TO REMAINDER OF ZONES SUNDAY AND MONDAY. AS THE SNOW
LEVELS DROP SUNDAY AND MONDAY THE MOUNTAINS WILL BEGIN RECEIVING
SNOW...WHICH COULD BECOME HEAVY.
&&
.PRELIMINARY POINT TEMPS/POPS...
EL PASO 57 33 56 35 68 / 0 0 0 0 0
SIERRA BLANCA 50 28 53 25 66 / 0 0 0 0 0
LAS CRUCES 57 31 58 30 66 / 0 0 0 0 0
ALAMOGORDO 52 29 54 31 61 / 0 20 0 0 0
CLOUDCROFT 32 18 34 23 42 / 20 50 10 10 0
TRUTH OR CONSEQUENCES 56 31 59 33 59 / 0 20 0 0 10
SILVER CITY 57 28 56 31 58 / 0 0 0 10 20
DEMING 62 30 60 32 65 / 0 0 0 0 0
LORDSBURG 67 29 63 32 64 / 0 0 0 0 10
WEST EL PASO METRO 55 34 58 36 69 / 0 0 0 0 0
DELL CITY 48 23 40 25 64 / 0 0 20 0 0
FORT HANCOCK 55 31 57 33 67 / 0 0 0 0 0
LOMA LINDA 48 28 49 26 64 / 0 0 0 0 0
FABENS 56 31 58 33 69 / 0 0 0 0 0
SANTA TERESA 57 32 58 32 68 / 0 0 0 0 0
WHITE SANDS HQ 52 30 54 30 63 / 0 0 0 0 0
JORNADA RANGE 53 25 56 25 64 / 0 0 0 0 0
HATCH 56 28 60 31 64 / 0 0 0 0 0
COLUMBUS 65 33 61 36 66 / 0 0 0 0 0
OROGRANDE 54 29 52 29 64 / 0 0 0 0 0
MAYHILL 32 17 30 21 50 / 20 60 20 10 0
MESCALERO 36 19 34 25 49 / 20 50 20 20 0
TIMBERON 37 20 35 24 49 / 10 30 10 10 0
WINSTON 51 27 46 31 56 / 0 20 0 10 20
HILLSBORO 54 30 46 31 60 / 0 10 0 0 20
SPACEPORT 57 27 56 28 61 / 0 20 0 0 0
LAKE ROBERTS 52 28 45 30 56 / 0 10 0 10 30
HURLEY 60 29 58 30 60 / 0 0 0 0 20
CLIFF 62 25 54 33 62 / 0 0 0 10 20
MULE CREEK 58 22 59 28 60 / 0 0 0 10 20
FAYWOOD 59 31 47 31 60 / 0 0 0 0 20
ANIMAS 68 30 65 38 66 / 0 0 0 0 10
HACHITA 62 28 57 33 66 / 0 0 0 0 10
ANTELOPE WELLS 67 34 63 39 67 / 0 0 0 0 10
CLOVERDALE 62 33 59 38 65 / 0 0 0 0 10
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
17 HEFNER
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
506 AM CST THU FEB 26 2015
.AVIATION...
AT 5 AM...THE COLD FRONT WAS LOCATED NEAR A SAN ANGELO TO DALLAS
LINE AND IS QUICKLY MOVING SOUTH. THE FRONT SHOULD BE THROUGH
KAUS/KDRT AROUND 17Z AND THOUGH THE SAN ANTONIO SITES SHORTLY
AFTER. THERE IS A NARROW BAND OF MVFR CEILINGS JUST BEHIND THE
FRONTAL BOUNDARY AND WILL SHOW A FEW HOURS OF POST FRONTAL MVFR
IN THE I-35 TAF SITES. THE FRONT WILL ALSO BRING BREEZY NORTH
WINDS WITH GUSTS UP TO 25 KNOTS EXPECTED THIS AFTERNOON. VFR WILL
PREVAIL BY LATE AFTERNOON BUT A RETURN TO MVFR IS EXPECTED AFTER
12Z TOMORROW AS LOW-LEVEL MOISTURE INCREASES ACROSS THE REGION.
PRECIPITATION CHANCES IN THE EXTENDED PORTION OF TAF AUS AND
TAFSAT ARE TOO LOW TO MENTION AT THIS TIME.
HAMPSHIRE
&&
.PREV DISCUSSION... /ISSUED 415 AM CST THU FEB 26 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
A FEW HIGHLIGHTS IN THE SHORT TERM INCLUDE A STRONG ARCTIC FRONTAL
PASSAGE TODAY AND THE POSSIBILITY OF LIGHT WINTER PRECIPITATION ON
FRIDAY.
WATER VAPOR CHANNELS AND RAP ANALYSIS DEPICT THE BASE OF A S/WV
TROUGH AXIS PIVOTING ACROSS TEXAS THIS MORNING. THIS TROUGH...IN
CONJUNCTION WITH A STRONG SURFACE HIGH OVER THE NORTHERN PLAINS
WILL DRIVE A SUBSTANTIALLY COLD AIR MASS THROUGH THE REGION STARTING
LATE MORNING INTO THE AFTERNOON WITH MORE CLOUDS. THIS COLD FRONT IS
CURRENTLY LOCATED NEAR ABILENE AS OF 10Z AND WHILE THE COLDEST AIR
WILL LAG BEHIND THE MAIN FRONT...TODAYS HIGHS WILL BE ABOUT 10F
DEGREES COOLER THAN YESTERDAY. GUSTY NORTH WINDS WILL OCCUR THROUGH
THE AFTERNOON AND THESE WERE INCREASED SLIGHTLY TOWARDS GFS LAMP
GUIDANCE. A WIDESPREAD FREEZE FOR MOST AREAS...OTHER THAN THE RIO
GRANDE VALLEY...IS EXPECTED FRIDAY MORNING WITH SOME READINGS
DIPPING TO THE MID TO UPPER 20S FOR THE HILL COUNTRY. WIND CHILLS
COULD FALL INTO THE TEENS FRIDAY MORNING.
HIGHS FRIDAY WILL STRUGGLE TO WARM...REACHING ONLY INTO THE MID 30S
IN THE HILL COUNTRY TO NEAR 40 ALONG THE 35 CORRIDOR AND MID 40S
TOWARDS THE COASTAL PLAINS. UNFORTUNATELY...IT APPEARS WEAK
ISENTROPIC UPGLIDE ALONG THE 290K LAYER WILL AID IN STEADY
MOISTENING OF THE BOUNDARY LAYER MID-MORNING INTO THE EVENING AND
THIS COULD LEAD TO SLIGHT CHANCES OF WINTER PRECIPITATION TYPES
ACROSS PORTIONS OF THE AREA BEFORE HIGHS ARE REACHED AND THEN AGAIN
OVERNIGHT INTO SATURDAY. NAM/GFS BUFR SOUNDINGS INDICATE THAT A
COMBINATION OF SLEET/RAIN AND SLEET/SNOW MIXES COULD OCCUR MAINLY
FOR THE HILL COUNTRY BUT NOT OUTSIDE THE POSSIBILITY OF THE I-35
CORRIDOR AS WELL. PRECIPITATION TOTALS ARE STILL LOW WITH ONLY A FEW
HUNDREDTHS LIKELY BUT IF CONCENTRATED ENOUGH...SOME MINOR IMPACTS
COULD OCCUR. WILL ISSUE AN SPECIAL WEATHER STATEMENT FOR THE HILL
COUNTRY AREA TO HIGHLIGHT THIS RISK. OVERALL CONFIDENCE IS MODERATE
GIVEN MODEL AGREEMENT ON VERTICAL PROFILES BUT ONE DETRACTOR OF
IMPACTS COULD BE THOSE PROFILES INDICATING A NEAR SURFACE DRY LAYER
THAT WOULD REQUIRE SOME ADIABATIC COOLING FOR PRECIPITATION TO MAKE
IT TO THE GROUND.
LONG TERM (SATURDAY THROUGH WEDNESDAY)...
HIGHLIGHTS THIS PERIOD CONTINUE TO BE THE WINTER PRECIPITATION
POSSIBILITY EARLY SATURDAY MORNING AND THEN A FOCUS ON A FRONTAL
PASSAGE TUESDAY/WEDNESDAY THAT COULD BRING A ROUND OF THUNDERSTORMS
TO THE AREA.
WEAK OVER-RUNNING OF THE SHALLOW ARCTIC AIRMASS WILL CONTINUE INTO
EARLY SATURDAY AS TEMPERATURES FALL BACK BELOW FREEZING FOR THE HILL
COUNTRY. WHILE THERE WILL BE LIMITED MOISTURE IN THE MID-LEVELS...
ENOUGH SATURATION IN THE SFC-H7 LAYER COULD BE ENOUGH FOR FREEZING
DRIZZLE/MIST. TEMPERATURES WILL WARM THROUGH THE DAY SATURDAY AS
LOW-LVL FLOW SHIFTS TO THE SOUTHEAST AND WAA COMMENCES...ENDING ANY
FURTHER WINTER PRECIP RISK.
SATURDAY AFTERNOON THROUGH NEXT TUESDAY WILL BE A WARMING TREND WITH
SOLID INCREMENTAL WARM UPS EACH DAY AS STRONGER SUBTROPICAL HIGH
PRESSURE INFLUENCES THE REGION. ABOVE NORMAL TEMPERATURES ARE
EXPECTED WITH HIGHS CLIMBING INTO THE 70S AND EVEN THE 80S BY EARLY
NEXT WEEK. CONCURRENTLY...A H5 TROUGH WILL DIG OVER CALIFORNIA AND
EVENTUALLY SWING EAST BY MID-WEEK. THERE REMAINS SOME DIFFERENCES IN
THE GFS/EC IN HANDLING THIS WAVE AND THUS THE TIMING OF THE
PACIFIC FRONT THAT SHOULD MOVE THROUGH THE REGION ON TUESDAY BUT IT
MAY BE DELAYED UNTIL WEDNESDAY. DESPITE THE TIMING DIFFERENCES...
ADDED MOISTURE /PWATS NEAR 90TH PERCENTILE/ LEADING TO SURFACE
INSTABILITY SHOULD EQUATE TO SOME THUNDERSTORM DEVELOPMENT. ANOTHER
DEEP ARCTIC PLUNGE LOOKS TO OCCUR THURSDAY WITH BELOW NORMAL
TEMPERATURES EXPECTED BY LATE WEEK. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 50 29 40 34 47 / 10 10 20 30 40
AUSTIN BERGSTROM INTL AIRPORT 50 28 40 34 47 / 10 10 20 30 40
NEW BRAUNFELS MUNI AIRPORT 55 30 42 35 49 / 10 10 20 30 40
BURNET MUNI AIRPORT 45 26 35 29 43 / 10 10 20 30 40
DEL RIO INTL AIRPORT 62 36 42 36 50 / - 20 20 40 20
GEORGETOWN MUNI AIRPORT 47 27 38 31 46 / 10 10 20 30 40
HONDO MUNI AIRPORT 61 33 41 35 49 / - 10 20 30 30
SAN MARCOS MUNI AIRPORT 53 29 41 34 49 / 10 10 20 30 40
LA GRANGE - FAYETTE REGIONAL 54 31 46 37 53 / 10 10 20 30 40
SAN ANTONIO INTL AIRPORT 57 30 41 36 48 / 10 10 20 30 40
STINSON MUNI AIRPORT 59 33 43 36 50 / - 10 20 30 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...29
SYNOPTIC/GRIDS...15
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
415 AM CST THU FEB 26 2015
.SHORT TERM (TODAY THROUGH FRIDAY)...
A FEW HIGHLIGHTS IN THE SHORT TERM INCLUDE A STRONG ARCTIC FRONTAL
PASSAGE TODAY AND THE POSSIBILITY OF LIGHT WINTER PRECIPITATION ON
FRIDAY.
WATER VAPOR CHANNELS AND RAP ANALYSIS DEPICT THE BASE OF A S/WV
TROUGH AXIS PIVOTING ACROSS TEXAS THIS MORNING. THIS TROUGH...IN
CONJUNCTION WITH A STRONG SURFACE HIGH OVER THE NORTHERN PLAINS
WILL DRIVE A SUBSTANTIALLY COLD AIR MASS THROUGH THE REGION STARTING
LATE MORNING INTO THE AFTERNOON WITH MORE CLOUDS. THIS COLD FRONT IS
CURRENTLY LOCATED NEAR ABILENE AS OF 10Z AND WHILE THE COLDEST AIR
WILL LAG BEHIND THE MAIN FRONT...TODAYS HIGHS WILL BE ABOUT 10F
DEGREES COOLER THAN YESTERDAY. GUSTY NORTH WINDS WILL OCCUR THROUGH
THE AFTERNOON AND THESE WERE INCREASED SLIGHTLY TOWARDS GFS LAMP
GUIDANCE. A WIDESPREAD FREEZE FOR MOST AREAS...OTHER THAN THE RIO
GRANDE VALLEY...IS EXPECTED FRIDAY MORNING WITH SOME READINGS
DIPPING TO THE MID TO UPPER 20S FOR THE HILL COUNTRY. WIND CHILLS
COULD FALL INTO THE TEENS FRIDAY MORNING.
HIGHS FRIDAY WILL STRUGGLE TO WARM...REACHING ONLY INTO THE MID 30S
IN THE HILL COUNTRY TO NEAR 40 ALONG THE 35 CORRIDOR AND MID 40S
TOWARDS THE COASTAL PLAINS. UNFORTUNATELY...IT APPEARS WEAK
ISENTROPIC UPGLIDE ALONG THE 290K LAYER WILL AID IN STEADY
MOISTENING OF THE BOUNDARY LAYER MID-MORNING INTO THE EVENING AND
THIS COULD LEAD TO SLIGHT CHANCES OF WINTER PRECIPITATION TYPES
ACROSS PORTIONS OF THE AREA BEFORE HIGHS ARE REACHED AND THEN AGAIN
OVERNIGHT INTO SATURDAY. NAM/GFS BUFR SOUNDINGS INDICATE THAT A
COMBINATION OF SLEET/RAIN AND SLEET/SNOW MIXES COULD OCCUR MAINLY
FOR THE HILL COUNTRY BUT NOT OUTSIDE THE POSSIBILITY OF THE I-35
CORRIDOR AS WELL. PRECIPITATION TOTALS ARE STILL LOW WITH ONLY A FEW
HUNDREDTHS LIKELY BUT IF CONCENTRATED ENOUGH...SOME MINOR IMPACTS
COULD OCCUR. WILL ISSUE AN SPECIAL WEATHER STATEMENT FOR THE HILL
COUNTRY AREA TO HIGHLIGHT THIS RISK. OVERALL CONFIDENCE IS MODERATE
GIVEN MODEL AGREEMENT ON VERTICAL PROFILES BUT ONE DETRACTOR OF
IMPACTS COULD BE THOSE PROFILES INDICATING A NEAR SURFACE DRY LAYER
THAT WOULD REQUIRE SOME ADIABATIC COOLING FOR PRECIPITATION TO MAKE
IT TO THE GROUND.
&&
.LONG TERM (SATURDAY THROUGH WEDNESDAY)...
HIGHLIGHTS THIS PERIOD CONTINUE TO BE THE WINTER PRECIPITATION
POSSIBILITY EARLY SATURDAY MORNING AND THEN A FOCUS ON A FRONTAL
PASSAGE TUESDAY/WEDNESDAY THAT COULD BRING A ROUND OF THUNDERSTORMS
TO THE AREA.
WEAK OVER-RUNNING OF THE SHALLOW ARCTIC AIRMASS WILL CONTINUE INTO
EARLY SATURDAY AS TEMPERATURES FALL BACK BELOW FREEZING FOR THE HILL
COUNTRY. WHILE THERE WILL BE LIMITED MOISTURE IN THE MID-LEVELS...
ENOUGH SATURATION IN THE SFC-H7 LAYER COULD BE ENOUGH FOR FREEZING
DRIZZLE/MIST. TEMPERATURES WILL WARM THROUGH THE DAY SATURDAY AS
LOW-LVL FLOW SHIFTS TO THE SOUTHEAST AND WAA COMMENCES...ENDING ANY
FURTHER WINTER PRECIP RISK.
SATURDAY AFTERNOON THROUGH NEXT TUESDAY WILL BE A WARMING TREND WITH
SOLID INCREMENTAL WARM UPS EACH DAY AS STRONGER SUBTROPICAL HIGH
PRESSURE INFLUENCES THE REGION. ABOVE NORMAL TEMPERATURES ARE
EXPECTED WITH HIGHS CLIMBING INTO THE 70S AND EVEN THE 80S BY EARLY
NEXT WEEK. CONCURRENTLY...A H5 TROUGH WILL DIG OVER CALIFORNIA AND
EVENTUALLY SWING EAST BY MID-WEEK. THERE REMAINS SOME DIFFERENCES IN
THE GFS/EC IN HANDLING THIS WAVE AND THUS THE TIMING OF THE
PACIFIC FRONT THAT SHOULD MOVE THROUGH THE REGION ON TUESDAY BUT IT
MAY BE DELAYED UNTIL WEDNESDAY. DESPITE THE TIMING DIFFERENCES...
ADDED MOISTURE /PWATS NEAR 90TH PERCENTILE/ LEADING TO SURFACE
INSTABILITY SHOULD EQUATE TO SOME THUNDERSTORM DEVELOPMENT. ANOTHER
DEEP ARCTIC PLUNGE LOOKS TO OCCUR THURSDAY WITH BELOW NORMAL
TEMPERATURES EXPECTED BY LATE WEEK. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 50 29 40 34 47 / 10 10 20 30 40
AUSTIN BERGSTROM INTL AIRPORT 50 28 40 34 47 / 10 10 20 30 40
NEW BRAUNFELS MUNI AIRPORT 55 30 42 35 49 / 10 10 20 30 40
BURNET MUNI AIRPORT 45 26 35 29 43 / 10 10 20 30 40
DEL RIO INTL AIRPORT 62 36 42 36 50 / - 20 20 40 20
GEORGETOWN MUNI AIRPORT 47 27 38 31 46 / 10 10 20 30 40
HONDO MUNI AIRPORT 61 33 41 35 49 / - 10 20 30 30
SAN MARCOS MUNI AIRPORT 53 29 41 34 49 / 10 10 20 30 40
LA GRANGE - FAYETTE REGIONAL 54 31 46 37 53 / 10 10 20 30 40
SAN ANTONIO INTL AIRPORT 57 30 41 36 48 / 10 10 20 30 40
STINSON MUNI AIRPORT 59 33 43 36 50 / - 10 20 30 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...29
SYNOPTIC/GRIDS...15
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
940 AM CST THU FEB 26 2015
.UPDATE...
A LAKE EFFECT SNOW ADVISORY IS IN EFFECT FOR RACINE AND KENOSHA
COUNTIES UNTIL 16Z THIS MORNING. LOOKS LIKE THE LAKE EFFECT SNOW
SQUALL IS STARTING TO SHIFT OFF TO THE EAST AS THE WINDS HAVE
STARTED BACKING TO A MORE NORTHWEST DIRECTION. THIS SHOULD HELP
MOVE THE SNOW SQUALL TO THE SOUTHEAST. MESO MODELS ALSO INDICATE
THE SNOW SQUALL WILL TAPER OFF RAPIDLY AND MOVE OUT OF THE
FORECAST AREA LATER THIS MORNING. EASTERN PORTIONS OF RACINE AND
KENOSHA WILL STILL BE DEALING WITH SOME LIGHT TO MODERATE SNOW FOR
THE NEXT HOUR OR SO.
&&
.AVIATION/18Z TAFS/...
MVFR CONDITIONS WILL PERSIST INTO THE AFTERNOON AS SOME LOW CLOUDS
WILL STICK AROUND THE AREA. ENW SHOULD SEE THE CURRENT LAKE
EFFECT SNOW SQUALL BAND QUICKLY SHIFT OFF TO THE EAST THIS MORNING.
OTHERWISE...EXPECT SOME LOW LEVEL CLOUDS...MAINLY FEW TO SCT WILL
PREVAIL THIS AFTN. SOME BKN SKIES COULD OCCUR AS LOW LEVEL LAPSE
RATES STEEPEN THIS AFTN. WINDS WILL STAY AT MORE NORTHERLY
DIRECTION THIS AFTN AND SHIFT MORE TO THE WEST AS ARCTIC HIGH
PRESSURE WILL ONCE AGAIN MOVE INTO THE REGION. COLD TEMPERATURES
WILL RETURN LATER TONIGHT. HOWEVER...WINDS SHOULD BE FAIRLY LIGHT
TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 527 AM CST THU FEB 26 2015/
UPDATE...DECIDED TO EXTEND LAKE EFFECT SNOW ADVY FOR MILWAUKEE CO
UNTIL 14Z AND RACINE/KENOSHA COUNTIES UNTIL 16Z. KMKX/TMKE RADARS
SHOW ENHANCED LAKE BAND CONTINUING TO REGENERATE AND EXTENDS ABOUT
30 MILES NORTHEAST OF KMKE AND IS MOVING STEADILY SSW AT 20KTS.
THIS WILL PROBABLY BE THE LAST ROUND OF HEAVIER SNOW SHOWERS IN
SOUTHEAST MKE COUNTY BUT MAY STILL CLIP ERN RACINE/KENOSHA
COUNTIES THROUGH LATE MRNG. LATEST RAP SHOWS ENHANCED CONVERGENCE
AND OMEGA WEAKENING AND SLIDING SOUTHEAST OF KENOSHA CO BY LATE
MRNG.
&&
.TODAY...FORECAST CONFIDENCE IS MEDIUM.
PULLED TRIGGER ON LAKE EFFECT SNOW ADVY FOR THREE SOUTHEAST
COUNTIES EARLIER. OBSERVER IN OAK CREEK HAD REPORTED 4 INCHES OF
FLUFF BEFORE LAKE BAND HAD DEVELOPED. AROUND 07Z...IMPRESSIVE LAKE
EFFECT ENHANCED BAND RAPIDLY DEVELOPED OVER THE NEAR SHORE WATERS
AND SPREAD INLAND BY 0730Z. THIS WAS WHEN THE STRONGEST LOW LEVEL
CONVERGENCE AND PEAK LIFT WERE TO OCCUR OVER THE NEARSHORE
WATERS...SPREADING INLAND THRU PARTS OF THE THREE COUNTIES.
WITH BAND ORIENTATED NNE TO SSW AND MOVING TO THE SSW...HIGH SNOW
LIQUID RATIOS WOULD RESULT IN ADDITIONAL 1 TO 3 INCHES...ADDING TO
THE ALREADY 1 TO 3 INCHES THAT HAD ALREADY OCCURRED OVER MUCH OF
THE AREA.
LATEST RAP13 CONTINUES TO SHOW OMEGA LINGERING OVER SE MKE COUNTY
UNTIL ABOUT 14Z AND ERN RAC/KEN COUNTIES UNTIL 15Z OR SO. HOWEVER
DURING THIS TIME...LOW LEVEL FLOW BEGINS BACKING MORE TO THE NORTH
TO NORTHEAST...DECREASING FETCH AND LOW LEVEL RH ALSO DECREASES.
MAY NEED TO EXTEND LAKE EFFECT SNOW ADVY FOR AN HOUR OR TWO
PENDING STRENGTH OF LAKE BAND.
OTHERWISE...GRADUAL CLEARING SHOULD CONTINUE AS DRIER AIR SLIDES
ACROSS SRN WI TODAY. MAY BE SOME LINGERING SC FOR A TIME THIS AFTN
DUE TO LINGERING LOW LEVEL RH FLOW AND STEEP LOW LEVEL LAPSE
RATES.
.TONIGHT...FORECAST CONFIDENCE IS HIGH.
HIGH PRESSURE RIDGE AXIS REMAINS WEST OF WI OVERNIGHT TONIGHT AS
SHORT WAVE RIDGING SETTLES IN. INCREASING SUBSIDENCE SHOULD CLEAR
SKIES OVERNIGHT AS LOW LEVEL FLOW TURNS NORTHWEST. WITH LAKE
SUPERIOR PRETTY WELL ICE-COVERED...NOT THINKING MUCH THREAT OF
LAKE CLOUDS FROM THE NORTH.
ENOUGH MIXINESS OF 3 TO 5 KTS OVERNIGHT...AND OVERNIGHT LOWS FROM
4 TO 12 BELOW...TO RESULT IN A THREE HOUR WINDOW OF WIND CHILLS
AROUND 20 BELOW. WL LET DAY SHIFT MAKE FINAL DECISION ON WIND
CHILL ADVY.
.SHORT TERM...FRIDAY THROUGH SUNDAY...FORECAST CONFIDENCE IS
MEDIUM.
MODELS ARE IN GOOD AGREEMENT WITH TAKING ARCTIC HIGH PRESSURE FROM
WESTERN IOWA TO NORTHERN OHIO FRIDAY AND FRIDAY NIGHT. THE HIGH
WILL BRING QUIET WEATHER BUT CONTINUED COLD TEMPERATURES. GIVEN
MOSTLY CLEAR SKIES AND STRONG INVERSION JUST ABOVE THE
SURFACE...COULD SEE RADIATIONAL COOLING WITH LOWS EVEN COLDER THAN
CURRENTLY FORECAST FRIDAY NIGHT.
WIND CHILLS AGAIN HOVER AROUND 20 BELOW ZERO FOR A COUPLE
HOURS...THOUGH WINDS MAY BE TOO LIGHT IF DECOUPLING OCCURS. LATER
SHIFTS CAN EVALUATE NEED FOR WIND CHILL ADVISORY.
WARM AIR ADVECTION SLOWLY DEVELOPS ACROSS THE AREA SATURDAY INTO
SATURDAY NIGHT...AS THE HIGH MOVES FURTHER EAST OF THE REGION.
DEEP MOISTURE SHIFTS NORTHEASTWARD INTO THE AREA SATURDAY
NIGHT...ALONG WITH INITIAL 500 MB VORTICITY MAXIMUM. SURFACE COLD
FRONT THEN SHIFTS EASTWARD THROUGH THE REGION SUNDAY. TIMING OF
THE FRONTAL PASSAGE VARIES SOMEWHAT ON THE MODELS. UPWARD VERTICAL
MOTION SATURDAY NIGHT AND SUNDAY IS WEAK TO MODEST...THOUGH DOES
TAP DENDRITE SNOW GROWTH ZONE.
SREF PROBABILITIES OF MEASURABLE PRECIPITATION ARE OVER 90
PERCENT FOR SATURDAY NIGHT. THUS...RAISED POPS ESPECIALLY LATER
SATURDAY NIGHT...WITH LIKELY VALUES IN THE SOUTHWEST COUNTIES. MAY
NEED EVEN HIGHER POPS SATURDAY NIGHT INTO SUNDAY MORNING IN LATER
FORECASTS...IF MODELS REMAIN CONSISTENT. COULD SEE 1 TO 2 INCHES
OF SNOW ACCUMULATION NORTH...TO 2 TO 3 INCHES SOUTH...HIGHEST
AMOUNTS FAR SOUTHEAST.
.LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY...FORECAST CONFIDENCE
IS MEDIUM.
MAIN ISSUE THIS PERIOD WILL BE SYSTEM FOR TUESDAY AND
PRECIPITATION AMOUNTS/TYPES. GFS/ECMWF ARE IN SOMEWHAT BETTER
AGREEMENT WITH THE SURFACE LOW TRACK. THEY TAKE LOW FROM CENTRAL
KANSAS TO CENTRAL ILLINOIS TUESDAY...THEN INTO THE EASTERN GREAT
LAKES REGION TUESDAY NIGHT. GOOD AMOUNT OF WARM AIR ADVECTION
OCCURS MONDAY NIGHT INTO TUESDAY...WITH STRONG MOISTURE ADVECTION
AND A 500 MB VORTICITY MAXIMUM PASSAGE INTO TUESDAY NIGHT.
MODELS SHOWING THE BEST UPWARD VERTICAL MOTION OVER THE AREA
TUESDAY. GFS FORECAST SOUNDINGS ARE SUGGESTING SOME MIXINESS OF
FREEZING RAIN/SLEET IN THE FAR SOUTH AND SOUTHEAST TUESDAY. RAISED
POPS FOR MONDAY NIGHT INTO TUESDAY NIGHT...HIGHEST ON TUESDAY.
SEVERAL INCHES OF SNOW ARE POSSIBLE...WITH SLEET/FREEZING RAIN
POSSIBLE...SO STAY TUNED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...LAKE EFFECT SNOW ADVISORY UNTIL 10 AM CST THIS MORNING FOR
WIZ071-072.
LM...SMALL CRAFT ADVISORY UNTIL 10 AM CST THIS MORNING FOR LMZ645-646.
&&
$$
UPDATE...JTS
TODAY/TONIGHT AND AVIATION/MARINE...MBK
FRIDAY THROUGH WEDNESDAY...WOOD
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
527 AM CST THU FEB 26 2015
.UPDATE...DECIDED TO EXTEND LAKE EFFECT SNOW ADVY FOR MILWAUKEE CO
UNTIL 14Z AND RACINE/KENOSHA COUNTIES UNTIL 16Z. KMKX/TMKE RADARS
SHOW ENHANCED LAKE BAND CONTINUING TO REGENERATE AND EXTENDS ABOUT
30 MILES NORTHEAST OF KMKE AND IS MOVING STEADILY SSW AT 20KTS.
THIS WILL PROBABLY BE THE LAST ROUND OF HEAVIER SNOW SHOWERS IN
SOUTHEAST MKE COUNTY BUT MAY STILL CLIP ERN RACINE/KENOSHA
COUNTIES THROUGH LATE MRNG. LATEST RAP SHOWS ENHANCED CONVERGENCE
AND OMEGA WEAKENING AND SLIDING SOUTHEAST OF KENOSHA CO BY LATE
MRNG.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...LAKE EFFECT SNOW ADVISORY UNTIL 8 AM CST THIS MORNING FOR WIZ066.
LAKE EFFECT SNOW ADVISORY UNTIL 10 AM CST THIS MORNING FOR
WIZ071-072.
LM...SMALL CRAFT ADVISORY UNTIL 10 AM CST THIS MORNING FOR LMZ645-646.
&&
$$
UPDATE...MBK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
920 PM MST WED FEB 25 2015
.UPDATE...
ISSUED AT 916 PM MST WED FEB 25 2015
LATEST RADAR IMAGERY...INFRARED SATELLITE IMAGERY AND AREA
OBSERVATIONS ARE ALL SHOWING SNOW EASING OVER THE AREA. WENT AHEAD
AND CANCELLED SNOW ADVISORY EARLY AS FURTHER ACCUMULATING SNOW NO
LONGER EXPECTED. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 309 PM MST WED FEB 25 2015
SFC COLD FRONT HAS SLID SOUTH OF THE CWFA TODAY LEAVING NORTHERLY
LLVL WINDS IN ITS WAKE. MODERATE TO AT TIMES HEAVY BANDS OF SNOW
DEVELOPED INITIALLY OVR THE HIER TERRAIN AS WELL AS ACROSS
NORTHEASTERN LARAMIE COUNTY. THIS POCKET OF MODERATE SNOW EXPANDED
AS IT SHIFTED WEST THRU MUCH OF THE DAY WITH THE MOST INTENSE AXIS
AT 21Z SETTLING ON THE SRN LARAMIE RANGE. LATEST SATELLITE PIX
SHOW CONVECTIVE ELEMENTS ESPECIALLY OVR THE HIER TERRAIN OF SRN
CARBON COUNTY WHERE INSTABILITY WAS PROGD TO BE THE GREATEST.
AREAS OF BLOWING SNOW IS ALSO A CONCERN WITH RECENT WIND GUSTS
OBSERVED AT 25- 35 MPH ACROSS SE WYOMING. IN AN EARLIER UPDATE
EXPANDED THE WINTER WEATHER ADVISORY INTO ARLINGTON AS WELL AS OVR
THE SRN LARAMIE RANGE FOOTHILLS LARAMIE COUNTY...WHERE SNOWFALL
RATES FROM BOTH WEBCAMS AND KCYS RADAR RETURNS WERE THE GREATEST.
THESE SNOWFALL RATES WILL WANE SOMEWHAT WITH INSTABILITY LOSS THIS
EVENING...THOUGH LINGERING LIGHT SNOW WILL STILL BE A GOOD
POSSIBILITY. IF SNOWFALL RATES ALLOW...EVENING SHIFT MAY BE ABLE
TO CANX THE ADVISORY EARLY. A COLD NIGHT AHEAD...ESPECIALLY ACROSS
SOUTHEAST WYOMING WHERE THE COMBINATION OF FRESH SNOWPACK AND SOME
LLVL CAA PLUMMET LOW TEMPERATURES TO AROUND 0F IN THE LARAMIE
VALLEY AND SINGLE DIGITS ELSEWHERE.
ALTHOUGH BEST SHORTWAVE ENERGY SHIFTS SOUTH OVERNIGHT...LLVL
FRONT WILL BECOME STATIONARY ACROSS CARBON COUNTY AT LEAST THRU
THE DAY ON THURSDAY. MODELS SUGGEST A SECONDARY SHORTWAVE WILL
PUSH ATOP THE FRONT PRODUCING SOME PERIODS OF LIGHT SNOW OR
FLURRIES. HIER ELEVATIONS AND AREAS NR THE CO/WY STATELINE WILL
HAVE THE BEST OPPORTUNITY TO SEE LT SNOW ON THURSDAY. ANY
ACCUMULATIONS WILL BE VERY LIGHT WITH PERHAPS UP TO AN INCH
POSSIBLE. THURSDAY WILL BE COLDER HOWEVER WITH HIGHS THAT WILL
RISE GENERALLY JUST INTO THE TEENS.
THE PATTERN BEGINS TO FLATTEN ON FRIDAY AS THE NEXT UPSTREAM
TROUGH CARVES TOWARDS THE GREAT BASIN. LLVL FLOW TURNS SOUTHEAST
AHEAD OF IT WHICH IS TYPICALLY A FAVORABLE FOG PATTERN FOR THE
CHEYENNE RIDGE AND LARAMIE COUNTY. SO IT WILL LIKELY BE A
CLOUDY/FOGGY START TO THE DAY FOR FRIDAY. FLATTENING FLOW WILL
PUSH THE FRONT EAST TO AROUND THE LARAMIE RANGE BY LATE FRIDAY.
THIS WILL HELP TEMPERATURES UP A FEW DEGREES WITH TEENS AND 20S
EXPECTED MOST AREAS. OUTSIDE OF MOUNTAIN LOCATIONS...SNOW CHANCES
WILL BE MINIMAL ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 309 PM MST WED FEB 25 2015
SATURDAY...ARCTIC AIR REMAINS ENTRENCHED THUS STILL WELL BELOW
NORMAL TEMPERATURES. SUFFICIENTLY MOIST AIRMASS PROGGED AND WITH
SOUTHWEST FLOW ALOFT AND AN APPROACHING SHORTWAVE TROUGH ALOFT AND
OROGRAPHICS...WILL SEE WIDESPREAD SNOWS OVER THE SNOWY AND SIERRA
MADRE RANGES WITH SCATTERED SNOW SHOWERS NEARBY.
SUNDAY...MOIST SOUTHWEST FLOW ALOFT CONTINUES PRODUCING WIDESPREAD
OROGRAPHIC SNOWS OVER OUR NORTHERN LARAMIE...SNOWY AND SIERRA MADRE
RANGES WITH MOSTLY DRY CONDITIONS ELSEWHERE. CONTINUED COLD WITH
ARCTIC AIR ENTRENCHED.
MONDAY...ARCTIC AIR WILL RETREAT EASTWARD WITH TEMPERATURES WARMING.
GFS LOOKS OVERDONE WITH QPF WITH THE SHORTWAVE TROUGH ALOFT MOVING
ACROSS AND PREFER THE LESS AMPLIFIED AND DRIER ECMWF VERSION WHICH
MESHES WELL WITH OUR SURROUNDING NEIGHBORING OFFICES...THUS EXPECT
SCATTERED OROGRAPHIC SNOWS OVER THE SNOWY AND SIERRA MADRE RANGES
AND DRY ELSEWHERE.
TUESDAY...COLD TEMPERATURES CONTINUE IN THE WAKE OF ANOTHER PASSING
ARCTIC COLD FRONT. MOIST WEST FLOW ALOFT AND ADEQUATE LOW AND MID
LEVEL MOISTURE WILL KEEP SCATTERED SNOWS WEST OF INTERSTATE 25 AND
MOSTLY DRY ELSEWHERE DUE TO DOWNSLOPING MID LEVEL WINDS.
WEDNESDAY...FLOW ALOFT TURNS NORTHWEST. NOW THE ECMWF LOOKS OVERDONE
WITH RESPECT TO QPF AND PREFER THE DRIER GFS VERSION SHOWING DRY AND
COLD NORTHWEST FLOW ALOFT...THUS EXPECT A WINDY DAY WITH PERHAPS A
FEW MOUNTAIN SNOW SHOWERS...AND DRY ELSEWHERE...WHICH MESHES WELL
WITH OUR SURROUNDING NEIGHBORING OFFICES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 916 PM MST WED FEB 25 2015
LATEST HRRR GUIDANCE USED FOR THE 06Z TAFS ACROSS SOUTHEAST
WYOMING AND NEBRASKA PANHANDLE. CEILINGS ARE COMING DOWN HERE AT
KCYS AND HRRR SHOWING A SMALL PERSISTENT IFR AREA OVER KCYS. LOOKS
LIKE WE COULD GET ANOTHER SHOT AT IFR CONDITIONS THURSDAY
AFTERNOON AS THE AREA SEES A WIDESPREAD LIGHT SNOW EVENT.
&&
.FIRE WEATHER...
ISSUED AT 309 PM MST WED FEB 25 2015
COLD TEMPERATURES AND UNSETTLED CONDITIONS WILL HOLD ANY FIRE
WEATHER CONCERNS AT BAY FOR THE FORESEEABLE FUTURE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...GCC
SHORT TERM...CAH
LONG TERM...RUBIN
AVIATION...GCC
FIRE WEATHER...CAH
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
305 AM MST SAT FEB 28 2015
.SYNOPSIS...
LOW PRESSURE WILL SLOWLY APPROACH THE AREA THIS WEEKEND...BRINGING
MOISTURE INTO THE REGION ALONG WITH INCREASING CHANCES OF SHOWERS
SUNDAY AND MONDAY. PERIODS OF HEAVY RAIN ARE POSSIBLE AT TIMES
ESPECIALLY SUNDAY NIGHT THROUGH MONDAY AFTERNOON. COOLER
TEMPERATURES WILL ALSO ACCOMPANY THIS STORM WITH BELOW NORMAL
READINGS EXPECTED MONDAY THROUGH LATE WEEK.
&&
.DISCUSSION...
...A PROLONGED WET WINTER WEATHER EVENT IS IN STORE FOR THE DESERT
SOUTHWEST SUNDAY THROUGH LATE MONDAY...
EARLY MORNING WATER VAPOR IMAGERY REVEALS DEEPENING LOW PRESSURE
OVER OREGON WITH AN INITIAL SHORTWAVE TROUGH DEVELOPING OVER
PORTIONS OF NEVADA AND CENTRAL CALIFORNIA. TO THE SOUTH ACROSS
ARIZONA AND SOUTHERN CALIFORNIA...THE LOW HAS STARTED ADVECTING
SOMEWHAT HIGHER PWATS AND SURFACE DEWPOINTS INTO THE AREA...EVEN
STARTING TO SEE SOME SHOWERS ON RADAR ACROSS CENTRAL ARIZONA NEAR
THE MID LEVEL MOISTURE GRADIENT. HOWEVER ACROSS THE LOWER DESERTS
THIS MORNING...THERE WAS ONLY A SUBTLE INCREASE IN CLOUD COVER. 09Z
TEMPERATURES WERE QUITE A BIT WARMER THAN THIS TIME FRIDAY WITH MANY
LOCATIONS STILL IN THE LOWER 60S.
A COUPLE OF THINGS TO ADDRESS THIS MORNING WITH RESPECT TO THE
POTENTIAL FOR RAINFALL ACROSS THE AREA THIS WEEKEND INTO EARLY NEXT
WEEK. AS HAS BEEN THE CASE FOR THE LAST SEVERAL DAYS...ALL
OPERATIONAL MODELS ARE IN AGREEMENT THAT THE UPSTREAM LOW WILL SAG
SOUTHWARD...DEEPEN...AND RETROGRADE WEST OF SAN DIEGO THIS WEEKEND.
THIS STILL LOOKS ON TARGET HOWEVER THERE ARE ONCE AGAIN SIGNALS IN
THIS MORNING`S 00Z GUIDANCE TO SUGGEST PRECIP WILL BE SLOW TO ARRIVE
ACROSS THE AREA...ESPECIALLY IN THE PHOENIX METRO.
CONCEPTUALLY...MUCH OF TODAY WILL BE SPENT MOISTENING THE BOUNDARY
LAYER AS THE LOW IS STILL SEVERAL HUNDRED MILES AWAY AND HAS YET TO
TAP INTO THE DEEPER/MORE SUBSTANTIAL SUBTROPICAL MOISTURE SOURCE
SOUTH OF BAJA CALIFORNIA. IN ALL LIKELIHOOD THERE WILL BE SCATTERED
SHOWERS TO THE NORTH AND EAST OF PHOENIX WITH A FEW ISOLATED SHOWERS
ACROSS THE METRO...BUT THAT`S ABOUT IT. THIS IDEA IS SUPPORTED BY
ALL OPERATIONAL 18Z AND 00Z DETERMINISTIC MODELS AND IS ALSO WITHIN
THE WINDOW OF THE LATEST /07Z AND 08Z/ HRRR RUNS. MADE SOME DOWNWARD
ADJUSTMENTS TO THE POPS FOR TODAY ESPECIALLY ACROSS THE LOWER
DESERTS ALONG WITH SOME UPWARD ADJUSTMENTS TO TEMPERATURES. NOT
GOING TO REMOVE THE MENTION OF PRECIP ALTOGETHER FOR THE PHOENIX
AREA AS THERE COULD EASILY BE 20-30 PERCENT COVERAGE ACROSS THE
METRO. BUT FOR THE MOST PART TODAY LOOKS TO BE MORE DRY THAN WET.
BY THIS EVENING THE LOW WILL BE LOCATED WEST OF LOS ANGELES BUT
STILL TOO FAR NORTH TO TAP INTO THE AFOREMENTIONED SUBTROPICAL
MOISTURE PLUME NEAR THE BAJA SPUR. THE MODELS ARE NOW SUGGESTING THE
BEST CHANCE OF PRECIP ACROSS SOUTHEAST CALIFORNIA AND FAR SW ARIZONA
WON`T OCCUR UNTIL DURING THE DAY ON SUNDAY...ABOUT 6-12 HRS SLOWER
THAN PREVIOUSLY INDICATED. FOLLOWING THAT TREND...PRECIP ISN`T
EXPECTED TO MOVE INTO THE PHOENIX AREA UNTIL MUCH LATER AS WELL
/SUNDAY AFTERNOON OR EVENING/. THUS I MADE SOME ADJUSTMENTS TO THE
POPS/QPF AND FLOOD WATCH TIMING FOR THIS EVENT TO BETTER MATCH THE
00Z DETERMINISTIC AND PROBABILISTIC GUIDANCE. I`M NOT REMOVING POPS
ALTOGETHER FOR THE PHOENIX AREA SUNDAY BUT DRASTICALLY TRIMMING
VALUES AND HIGHLIGHTING SUNDAY EVENING THROUGH MID-DAY MONDAY AS THE
PRIME-TIME FOR SHOWERS ACROSS THE AREA. POPS DURING THIS SUNDAY
EVENING-MONDAY TIME PERIOD STILL LOOK GOOD IN THE 80-100 PERCENT
RANGE AS THIS IS WHEN THE UPPER LOW FINALLY GETS A KICK FROM ANOTHER
UPSTREAM TROUGH. ALSO NOTED A SOMEWHAT CONCERNING REDUCTION IN
ENSEMBLE QPF THIS MORNING WITH THE HIGHEST MEMBERS INDICATING AROUND
1 INCH OF PRECIP IN THE PHOENIX AREA...WITH A MEAN MORE IN THE
0.5-0.75 INCH REALM. PERHAPS THIS IS A RESULT OF THE MORE
PROGRESSIVE NATURE OF THE TROUGH VS THE SOMEWHAT NEGATIVELY TILTED
DEPICTION THE MODELS WERE INDICATING THE PAST FEW DAYS.
REGARDLESS...THERE WILL ALMOST CERTAINLY BE LOCALLY HIGHER VALUES
ESPECIALLY IN THE OROGRAPHICALLY FAVORED AREAS NORTH/EAST OF PHOENIX
WITHIN THE INHERITED FLOOD WATCH BUT I WILL MAKE SOME REDUCTIONS TO
THE TOTAL QPF FORECAST ESPECIALLY ACROSS THE SOUTHERN HALF OF THE
FORECAST AREA. WILL ADJUST THE FLOOD WATCH TO RUN FROM 5 PM SUNDAY
TO 5 PM MONDAY.
RAINFALL WILL QUICKLY MOVE THROUGH THE AREA MONDAY BUT ONE MORE
UPSTREAM TROUGH WILL DIVE SOUTHWARD TUESDAY AFTERNOON. PRECIP
CHANCES WITH THIS TROUGH WILL BE HIGHEST NORTH/EAST OF PHOENIX BUT
STILL THINK THERE COULD BE SOME SCATTERED SHOWERS ACROSS THE
DESERTS. WILL LEAVE THE FORECAST FOR TUESDAY LARGELY UNCHANGED WITH
20-30 POPS AROUND PHOENIX AND 40-50 POPS IN THE HIGHER TERRAIN.
AFTER THAT...DRY NORTHWESTERLY FLOW WILL PERSIST THROUGH MID
WEEK...FOLLOWED BY LATE WEEK RIDGING/WARMING. TEMPERATURES WILL
REACH THEIR LOWEST VALUES ON MONDAY AND WILL SLOWLY REBOUND BACK
INTO THE UPPER 70S/LOWER 80S BY LATE NEXT WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
AN APPROACHING WEATHER SYSTEM IS EXPECTED TO TIGHTEN THE PRESSURE
GRADIENT OVER THE REGION OVER THE NEXT 24 HOURS. THE MAIN IMPACTS TO
THE PHX AREA TERMINALS WILL BE TO ENHANCE THE NORMAL SE-LY DRAINAGE
WINDS TONIGHT...WITH SUSTAINED WIND SPEEDS AS HIGH AS 15KT POSSIBLE
BY DAYBREAK ON SATURDAY. ONCE THE WINDS SWITCH TO WESTERLY SAT
AFTERNOON...SUSTAINED WINDS AROUND 15KTS WITH GUSTS TO 25KTS CAN BE
EXPECTED. LOW LEVEL MOISTURE WILL START INCREASING LATE TONIGHT AS
WELL...WHICH SHOULD ALLOW FOR SOME LOWER SCT CLOUD LAYERS TO DEVELOP
AT AROUND 5-6K FEET FOR A TIME ON SATURDAY MORNING...WITH THESE
CLOUDS LIKELY BEING MIXED OUT FOR A TIME ON SAT AFTERNOON BEFORE
REDEVELOPING SAT EVENING. THERE IS AN OUTSIDE RISK OF FEW-SCT
SHOWERS DEVELOPING AS WELL ON SAT...BUT CONFIDENCE IS TOO LOW TO
INCLUDE IN THE TAFS AT THIS TIME...EXCEPT FOR VCSH AT KSDL.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
LOW PRESSURE APPROACHING FROM THE NORTHWEST IS EXPECTED TO KEEP
GUSTY WESTERLY WINDS GOING AT KIPL AND SOUTHWESTERLY WINDS AT KBLH
THROUGH THE ENTIRE TAF PERIOD...WITH GUSTS AS HIGH AS 35KT...AND
EVEN AN OUTSIDE CHANCE OF BLOWING DUST POSSIBLE FOR A TIME ON SAT AT
BOTH TAF SITES. INCREASING MOISTURE LEVELS THROUGH THE COLUMN WILL
ALLOW CIGS TO GRADUALLY LOWER THROUGH THE TAF PERIOD...WITH CLOUD
BASES DROPPING AS LOW AS 5K FT ON SAT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
COOL AND WET CONDITIONS WILL BE PRESENT THROUGH THE FIRST PART OF
THE PERIOD WITH THE BEST CHANCES FOR WIDESPREAD RAINS ON SUNDAY AND
MONDAY. THERE WILL BE A CHANCE OF A FEW THUNDERSTORMS ON MONDAY AND
POTENTIALLY TUESDAY. HUMIDITIES WILL BE WELL ABOVE TYPICAL VALUES
THROUGH TUESDAY BEFORE MINIMUM VALUES FALL BACK TO AROUND 20 PERCENT
ON THURSDAY AFTERNOON. PERIODS OF BREEZY SOUTHWESTERLY WINDS CAN BE
EXPECTED ON MONDAY AND TUESDAY. HIGH TEMPERATURES ACROSS THE DESERTS
WILL ONLY REACH INTO THE 60S SUNDAY THROUGH WEDNESDAY. HIGH PRESSURE
AND DRIER WEATHER SHOULD MOVE IN STARTING LATER WEDNESDAY AND SHOULD
PERSIST THROUGH THE END OF THE WEEK.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLOOD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON
AZZ021>024.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...PERCHA
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
955 PM MST FRI FEB 27 2015
.UPDATE...
ISSUED AT 950 PM MST FRI FEB 27 2015
ONLY A FEW MORE TWEAKS AT THIS POINT...DROPPED LOWS A DEGREE OR
TWO MOST PLACES BUT MORE IN NORTH PARK WHERE IT IS ALREADY NEAR
ZERO.
UPDATE ISSUED AT 555 PM MST FRI FEB 27 2015
WITH CLEARING DENOTED OVER SOME OF THE NORTHERN MOUNTAINS AS WELL
AS OVER THE PLAINS ON SATELLITE AND OBSERVATIONS...HAVE ADJUSTED
FORECAST POP...SKY AND WEATHER GRIDS. WITH LITTLE MIDLEVEL MOISTURE
OVER THE PLAINS...HAVE CHANGED THE SLIGHT CHANCE OF SNOW TO A
SLIGHT CHANCE OF FLURRIES. SEEMS AS THOUGH OVERALL...MODELS AND
CONDITIONS WILL SLOW THE CHANCE FOR SNOW AFTER TOMORROW`S EXPECTED
COLD FRONT COMPARED TO FORECAST TIME....HAVE BACKED OFF A COUPLE
HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 126 PM MST FRI FEB 27 2015
FOR TONIGHT...A RELATIVELY MOIST WESTERLY FLOW ALOFT WILL BE
OVER COLORADO. PERSISTENT OVERRUNNING LIGHT SNOW HAS CONTINUED IN
THE MOUNTAINS WITH A COUPLE OF INCHES AT THE SKI AREAS TODAY.
THIS WILL CONTINUE INTO THE EVENING SO WL KEEP LIKELY POPS GOING
AT LEAST IN ZONE 34 THROUGH THIS EVENING...WITH ANOTHER 1-2 INCHES
POSSIBLE. ACROSS THE NORTHEAST PLAINS...SOME NAGGING STRATUS AND
POCKETS OF LIGHT SNOW TRAPPED UNDER AN INVERSION THROUGH THE DAY.
GUSTY SSELY WINDS ACROSS THE NORTHEAST PLAINS BUT HIGHWAY CAMS DO
NOT SHOW MUCH IMPACT FROM BLOWING SNOW. DENVER CYCLONE WILL
CONTINUE OVERNIGHT WITH THE MDLS SHOWING LOW BOUNDARY LYR MOISTURE
WRAPPING INTO THE DENVER AREA LATE TONIGHT INTO SATURDAY
MORNING...10-16Z. NOT SURE IF IT WILL BE A LOW STRATUS DECK FOR
FOG...FOR NOW WL HEDGE THINGS TOWARDS STRATUS BUT ALSO MENTION
PATCHY FREEZING FOG. WEAK MID AND UPPER LEVEL QG DOES START TO
ADVECT INTO THE MOUNTAINS FM THE WEST ON SATURDAY AS THE NEXT
UPPER TROUGH DROPS INTO THE GREAT BASIN. WL KEEP THE MENTION OF
SNOW WITH ACCUMULATIONS IN THE 1-4 INCH RANGE FOR THE MOUNTAINS...
FAVORING ZONE 34 THE MOST. AS FOR THE NORTHEAST PLAINS...THE COLD
FRONT DOES SLIP INTO DENVER IN THE AFTN...WITH NELY UPSLOPE WINDS
IN THE AFTN. SHOULD SEE LIGHT SNOW DEVELOPING IN AND NEAR THE
FOOTHILLS AND PALMER DIVIDE AFTER 21Z.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 126 PM MST FRI FEB 27 2015
AN UPPER LEVEL LOW WILL SLOWLY MOVE SOUTH ACROSS CALIFORNIA SATURDAY
NIGHT THROUGH MONDAY. THIS WILL KEEP A SOUTHWEST FLOW ALOFT OVER
COLORADO. FOR SATURDAY NIGHT...A WEAK WAVE EMBEDDED IN THE FLOW
ALOFT WILL MOVE ACROSS COLORADO. MEANWHILE...A SURFACE HIGH WILL
MOVE FROM THE NORTHERN ROCKIES SOUTHEAST TO THE CENTRAL PLAINS
SATURDAY NIGHT AND SUNDAY. THIS WILL KEEP A WEAK NORTH TO NORTHEAST
UPSLOPE LOW LEVEL FLOW OVER NORTHEAST COLORADO. LIFT FROM THE WAVE
AND LOW LEVEL UPSLOPE ALONG THE FRONT RANGE WILL PRODUCE LIGHT SNOW
SATURDAY NIGHT AND EARLY SUNDAY. MAY ALSO GET SOME LIFT FROM THE JET
AXIS AS IT SHIFTS NORTH ACROSS COLORADO. EXPECT UP TO 3 INCHES ALONG
THE FRONT RANGE...WITH A LITTLE LESS OVER THE EASTERN PLAINS.
MOUNTAIN TOP LEVEL WINDS WILL INCREASE SUNDAY BEHIND THE WAVE
HELPING TO PRODUCE OROGRAPHIC SNOW. EXPECT TOTALS TO BE A LITTLE
HIGHER IN THE MOUNTAINS SINCE IT WILL SNOW LONGER...GENERALLY 2 TO 6
INCHES FOR SATURDAY NIGHT AND SUNDAY TIME FRAME.
ON MONDAY...MODELS SHOWING HEAVY SNOW OVER THE MOUNTAINS OF WESTERN
COLORADO ASSOCIATED WITH A DEEP MOIST STRONG SOUTHWEST FLOW ALOFT.
THIS IS EXPECTED BRING SNOW TO PARTS OF THE NORTH CENTRAL MOUNTAINS.
IF FLOW BACKS TOO SOUTHERLY...THE NORTHERN CENTRAL MOUNTAINS MAY
MISS OUT ON A GOOD PART OF THE HEAVY SNOW. OVER THE PLAINS...
SOUTHERLY FLOW WILL WARM TEMPERATURES AND BRING DRY CONDITIONS.
AS THE UPPER LEVEL TROUGH FILLS AND MOVES INLAND...FLOW ALOFT WILL
TURN MORE WESTERLY AND BRING A BETTER CHANCE FOR SNOW TO THE
MOUNTAINS MONDAY NIGHT AND TUESDAY. IN THE MEANTIME...A STRONG WAVE
WILL DROP SOUTH ACROSS THE NORTHERN ROCKIES AND INTO THE CENTRAL
ROCKIES TUESDAY NIGHT. A COLD FRONT WILL ACCOMPANY THE WAVE FROM THE
NORTH. THIS IS EXPECTED TO BRING A ROUND OF WIDESPREAD SNOW TUESDAY
AND TUESDAY NIGHT. THE AIRMASS BEHIND IT WILL BE COLD. SNOW IS
EXPECTED TO TAPER OFF EARLY WEDNESDAY AS THE UPPER LEVEL SYSTEM
MOVES EAST OF THE AREA. HIGHS WILL STRUGGLE TO CLIMB ABOVE 20
DEGREES WEDNESDAY. IF IT CLEARS OUT WEDNESDAY NIGHT...SUB ZERO LOWS
WILL BE POSSIBLE.
FOR THURSDAY AND FRIDAY...THERE WILL BE A BREAK FROM THE SNOW AND
COLD. AN UPPER LEVEL RIDGE BUILDS OVER THE GREAT BASIN AND PRODUCES
A DRY NORTHWEST FLOW ALOFT OVER COLORADO. TEMPERATURES WILL
WARM...BUT ARE STILL EXPECTED TO BE SLIGHTLY BELOW NORMAL. THE
WARMING TREND WILL CONTINUE INTO FRIDAY WITH HIGHS EXPECTED TO BE
AROUND NORMAL WITH UPPER 40S AND LOWER 50S EXPECTED OVER NORTHEAST
COLORADO.
&&
.AVIATION...(FOR THE TAFS THROUGH 06Z SATURDAY EVENING)
ISSUED AT 950 PM MST FRI FEB 27 2015
LATEST HRRR MATCHES PREVIOUS EXPECTATIONS OF INCREASING THE DENVER
CYCLONE CIRCULATION OVERNIGHT AND SHIFTING IT EASTWARD IN THE
MORNING. THIS SHOULD BRING NORTH TO NORTHWEST WINDS INTO KDEN/KAPA
AND PROBABLY SOME COOL AIR WITH LOW CLOUDS AND/OR FOG. FOR NOW
WILL STICK WITH THE PLAN OF STRATUS AS LOW LEVEL AIR HAS DRIED TO
THE NORTH...BUT IN ANY EVENT A DECENT CHANCE OF IFR OF LOWER END
MVFR CONDITIONS FOR SEVERAL HOURS AROUND SUNRISE. STILL EXPECTING
LIGHT SNOW TO SPREAD INTO THE DENVER AREA BETWEEN 21Z AND 00Z
SATURDAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GIMMESTAD
SHORT TERM...COOPER
LONG TERM...MEIER
AVIATION...GIMMESTAD
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
400 AM EST SAT FEB 28 2015
.SYNOPSIS...
09Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A CURRENTLY UNAMPLIFIED
UPPER LEVEL PATTERN ACROSS THE CONUS. A GENERAL ZONAL FLOW PATTERN
IS IN PLACE OVER MUCH OF THE CONUS...ALTHOUGH ENERGY DIPPING SOUTH
ALONG THE PACIFIC COAST IS IN THE PROCESS OF EVOLVING A DEEPER
TROUGH ACROSS THE FAR WEST. THIS TROUGH WILL HAVE A POSITIVE
INFLUENCE ON OUR FORECAST AS IT EVENTUALLY HELPS TO BUILD DOWNSTREAM
RIDGING OVER THE GULF OF MEXICO AND FL PENINSULA BY THE EARLY
PORTION OF THE UPCOMING WEEK. IN THE SHORT TERM HOWEVER...OUR UPPER
LEVEL FLOW CONSISTS OF DEEP LAYER SOUTHWESTERLY FLOW OVERTOP A
SHALLOW NORTHEAST TO EASTERLY REGIME IN THE VERY LOWEST LEVELS. THE
EASTERLY FLOW IN THE LOWEST LEVELS IS THE RESULT OF THE GRADIENT
AROUND STRONG 1040+MB HIGH PRESSURE RIDGING DOWN THE ATLANTIC
SEABOARD INTO OUR REGION. THIS PATTERN WILL PERSIST FOR THE
REMAINDER OF TODAY...AND HELP DEVELOP/EXPAND A DECENT ISENTROPIC
UPGLIDE REGION NORTHWARD OVER THE FL PENINSULA.
THIS UPGLIDE REGIME IS JUST STARING TO GET ITS ACT TOGETHER WITH A
WIDESPREAD LOWER CLOUDS DECK AND A FEW SPRINKLES/LIGHT SHOWERS
SHOWING UP ON RADAR ACROSS THE REGION. THIS CLOUD DECK IS FOCUSED
BENEATH A PRONOUNCED INVERSION WHERE WINDS VEER FROM NORTHEAST TO
SOUTHEAST BETWEEN 950-900MB...AND ANOTHER INVERSION AROUND 850MB AS
SEEN ON THE 28/00Z KTBW SOUNDING PROFILE. WITH THE LOW LEVEL RIDGE
CONTINUING TO RIDGE SOUTHWARD INTO THE DAYLIGHT HOURS...THIS PATTERN
WILL ENSURE A MOSTLY CLOUDY DAY WITH SCATTERED LIGHT SHOWERS FOR
ALL.
FURTHER TO THE NORTH WE FIND NARROW BY FOCUSED ZONE OF RAIN
EXTENDING FROM SOUTH OF APALACHICOLA TO THE NATURE COAST OF
LEVY/DIXIE COUNTIES. WHILE THERE IS SOME WEAK UPGLIDE BEGINNING UP
OVER THESE AREAS AS WELL...THIS BAND OF RAIN IS MAINLY BEING FORCED
BY A APPROACH OF A SUBTLE SHORTWAVE...AND A WELL DEFINED COUPLED
UPPER LEVEL JET STRUCTURE. THE RER (RIGHT ENTRANCE REGION) OF
NORTHERN STREAM JET ENERGY EXITING UP THE EAST COAST IS COINCIDENT
WITH THE LER (LEFT EXIT REGION) OF A SOUTHERN STREAM JET STREAK
CROSSING INTO THE NORTHEAST GULF OF MEXICO. PRONOUNCED UPPER LEVEL
DIVERGENCE FIELDS ARE SHOWN BY THE GUIDANCE SUITE AND LINE UP
VERY WELL WITH THE ONGOING BAND OF RAIN. THIS BAND OF RAIN WILL BE
FLIRTING WITH NORTHERN LEVY COUNTY (CHIEFLAND) AREA INTO THE MORNING
HOURS...BEFORE THE SHORTWAVE DYNAMICS AND UPPER DIVERGENCE SHIFT
EASTWARD OUT OF OUR REGION FOR THE AFTERNOON.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
TODAY...WELCOME TO THE FINAL DAY OF METEOROLOGICAL WINTER. WHILE
ASTRONOMICAL SPRING DOES NOT ARRIVE UNTIL MARCH 20TH...
METEOROLOGICAL WINTER IS DEFINED AS DECEMBER THROUGH FEBRUARY...
WHICH MEANS TOMORROW IS THE START OF METEOROLOGICAL SPRING! IT WILL
CERTAINLY BE FEELING LIKE SPRING AROUND THESE PARTS BY THE EARLY
PART OF NEXT WEEK.
AS MENTIONED IN THE SYNOPSIS...WILL BE WATCHING THE EVOLUTION OF THE
NARROW BUT FOCUSED BAND OF RAIN FORCED BY THE COUPLED UPPER JET
STRUCTURE MOVING ACROSS APALACHEE BAY INTO THE NATURE COAST.
GENERALLY SPEAKING THE MAJORITY OF THIS RAIN SHOULD STAY JUST TO THE
NORTH OF LEVY COUNTY...BUT IT IS A VERY CLOSE CALL...AND SHOWER
ALONG THE SOUTHERN PERIPHERY OF THE BAND WILL PERIODICALLY REACH FAR
ENOUGH SOUTH TO IMPACT AREAS AROUND CHIEFLAND. HAVE LIKELY POPS FOR
NORTHERN LEVY COUNTY THIS MORNING TO ACCOUNT FOR THIS. ELSEWHERE THE
EXPANDING UPGLIDE REGIME AND CONTINUED MOISTENING OF THE LOW LEVEL
COLUMN SHOULD RESULT IN WIDELY SCT SPRINKLES GIVING WAY TO SCATTERED
SHOWERS ACROSS THE REGION. CERTAINLY SOME AREA WILL END UP WITH
CONDITIONS WARRANTING LIKELY RAIN CHANCES...BUT IT IS TOUGH TO
PREDICT WITHIN SUCH A BROAD UPGLIDE REGIME JUST WHERE THE BEST QPF
FIELDS WILL DEVELOP. OVERALL THE BEST UPGLIDE FIELDS COINCIDENT WITH
SPEED CONVERGENCE ALONG THE EAST COAST SUGGEST THE HIGHEST COVERAGE
OF SHOWERS WILL BE OVER OUR INTERIOR ZONES. SLOWLY RAMP UP THE POPS
ACROSS THE REGION THROUGH THE DAY...ALLOWING AREAS WELL INLAND AND
SOUTH OF I-4 TO GO LIKELY FOR RAIN CHANCES DURING THE AFTERNOON.
ELSEWHERE HAVE HIGH END CHANCE 45-55% POPS. GENERALLY SPEAKING THE
SHOWERS SHOULD BE ON THE LIGHTER SIDE WITH QPF UNDER A QUARTER OF AN
INCH...AND IN MOST CASES UNDER A TENTH OF AN INCH. THE UPGLIDE
REGIME...AND DEFINED INVERSIONS WILL KEEP OUR SKIES MOSTLY CLOUDY
AND DISCOURAGE RAPID DIURNAL TEMP RISES. THE BEST CHANCES AT ANY
BREAKS OF SUN IN THE AFTERNOON WILL BE DOWN SOUTH OF SARASOTA...AND
WILL ALLOW TEMPS TO BREAK INTO THE LOWER/MID 70S FOR THESE SOUTHERN
ZONES. TEMPS FURTHER NORTH WILL STRUGGLE MORE AS THE UPGLIDE ONLY
INCREASES THROUGH THE DAY...AND THE RIDGE CONTINUES TO SUPPLY
DRIER AIR TO THE BOUNDARY LAYER. WET BULB EFFECTS FROM THE SCT
SHOWERS FALLING THROUGH THE BOUNDARY LAYER WILL FURTHER SLOW THE
TEMPERATURE RISE...AND THINK LOCATIONS UP TOWARD TAMPA WILL STRUGGLE
TO REACH 70...AND UP TOWARD LEVY COUNTY MAY STRUGGLE TO RISE INTO
THE LOWER 60S TODAY.
TONIGHT...
UPGLIDE REGIME ABOVE 5000 FEET WILL BEGIN TO PIVOT OFF TO THE
NORTHEAST WITH TIME LEAVING JUST THE VERY LOWEST LEVELS WITH ANY
LIFT. GUIDANCE IS IN AGREEMENT THAT SHOWER PRODUCTION WILL BEGIN TO
DISSIPATE QUICKLY AS THIS OCCURS AND ALSO PIVOT NORTHEAST DURING THE
EVENING HOURS. WILL TAPER RAIN CHANCES THIS EVENING AND GENERALLY
END THE SHOWERS FOR ALL AREAS AFTER MIDNIGHT. HOWEVER...THE LOWER
UPGLIDE REGIME WILL LIKELY CONTINUE TO SUPPORT LOWER STRATUS AND
WILL KEEP THE FORECAST FOR MOSTLY CLOUDY TO CLOUDS SKIES. OVERNIGHT
THE RIDGE ALSO BEGINS TO SLOWLY WEAKEN TO OUR NORTH AND ALLOW THE
GRADIENT TO RELAX OVER OUR REGION. THIS WEAKER GRADIENT IS SHOWN BY
MANY OF THE GUIDANCE MEMBERS TO ALLOW A WELL DEFINED INVERTED
SURFACE TROUGH TO DEVELOP JUST EAST OF FLORIDA OVER THE WARMER
WATERS OF THE GULF STREAM. THIS SURFACE TROUGH WILL ALSO HELP TO
FOCUS THE MAJORITY OF THE SHOWER ACTIVITY TO THE EAST AND NORTHEAST
OF OUR ZONES.
SUNDAY...
THE RIDGE LOOSES ITS GRIP ON OUR AREA ALLOWING A MUCH WEAKER
GRADIENT AND WEAKER EASTERLY FLOW TO DEVELOP. ALTHOUGH THE EASTERLY
FLOW WILL BE WEAKER...IT IS STILL SHOW TO BE ENOUGH TO MIGRATE THE
SURFACE TROUGH MENTIONED ABOVE WESTWARD OVER THE FL PENINSULA DURING
THE DAY. THIS WILL COME INTO PLAY DURING THE AFTERNOON. SUNDAY WILL
SEE THE FIRST SIGNS OF RIDGING BUILDING NORTH FROM THE CARRIBEAN
WITH OUR UPPER FLOW BECOMING MORE WESTERLY. THE LOSS OF THE
INFLUENCE FROM THE SURFACE RIDGE WILL QUICKLY DISSIPATE THE
INVERSION AND ALLOW ANY MORNING LOWER STRATUS TO BURN OFF...AND
SKIES TO BECOME PARTLY CLOUDY. THE ATMOSPHERIC TEMP POTENTIAL IS
QUITE HIGH ON SUNDAY AND THE SUNNY BREAKS SHOULD HELP BOOST TEMPS
INTO THE THE 70S NORTH AND LOWER 80S SOUTH. THE STRONG TERRESTRIAL
HEATING SHOULD ALLOW FOR WINDS TO TURN ONSHORE FOR A TIME DURING THE
AFTERNOON WITH SEA-BREEZE DEVELOPMENT. THIS IS WHERE THINGS GET
INTERESTING. WE LOOK TO ALREADY HAVE A WEAK SURFACE TROUGH IN PLACE
NEARBY TO FOCUS SOME MEAGER LOW LEVEL CONVERGENCE...NOW ADD
CONVERGENCE AS THE SEA-BREEZE INTERACTS WITH THE SURFACE TROUGH AND
WE CAN NOT RULE OUT THE POTENTIAL FOR A FEW AFTERNOON CONVECTIVE
SHOWERS...OR EVEN A THUNDERSTORM TO THE SOUTH OF I-4. IT IS
IMPORTANT TO NOTE THAT SUNDAY IS NOT GOING TO BE A WET DAY...AND
OUTDOOR PLANS SHOULD NOT BE DISCOURAGED. HOWEVER...HAVE GONE WITH A
20-30% POP SUNDAY AFTERNOON FOR THE POTENTIAL WIDELY SCT CONVECTION.
ANY RAINFALL WILL BE SHORT-LIVED...BUT HAVE TO AT LEAST MENTION THE
POTENTIAL IN THE FORECAST.
&&
.LONG TERM (MONDAY THROUGH NEXT FRIDAY)...
THROUGH WED; A BUILDING UPPER LEVEL RIDGE CENTERED OVER THE
YUCATAN...AND DOMINATING THE GULF OF MEXICO...SLOWLY SLIDES
EAST AND STRETCHES FROM THE WESTERN CARIBBEAN TO NORTHEAST OF
THE BAHAMAS. THIS IS IN RESPONSE TO A LONG WAVE TROUGH DEEPENING
OVER THE WESTERN CONUS. AT THE SURFACE HIGH PRESSURE EXTENDING
ACROSS FL FROM THE ATLANTIC WILL MOVE EAST AS HIGH PRESSURE OVER THE
NORTHERN AND CENTRAL PLAINS TRACKS EAST...ACROSS THE EASTERN SEA
BOARD TO THE OPEN ATLANTIC. THE UPPER LEVEL RIDGING WILL PROVIDE A
STABLE AND GENERALLY DRY AND WARM AIRMASS WITH TEMPERATURES ON THE
WARM SIDE OF NORMAL AND NO SIGNIFICANT RAINFALL. THE DEPARTING HIGH
PRESSURE OVER THE ATLANTIC AND THE PLAINS HIGH PRESSURE MOVING BY TO
THE NORTH WILL RESULT IN A RELAXED EASTERLY LOW LEVEL FLOW THAT
GRADUALLY BECOMES SOUTHEAST AND SOUTHERLY AND SLIGHTLY MORE ROBUST.
THE SOUTHERLY FLOW WILL ADVECT ENOUGH WARM AND HUMID AIR ACROSS THE
COOLER SHELF WATERS OF THE GULF TO POSSIBLY FORM SOME SEA FOG AROUND
MID-WEEK.
THU-FRI; BY THU THE WESTERN LONG WAVE TROUGH HAS MOVED EAST...
FROM THE UPPER GREAT LAKES TO THE SOUTHERN HIGH PLAINS...AND
CONTINUES TO THE EASTERN SEABOARD BY FRI AS IT DE-AMPLIFIES SOME.
THE CARIBBEAN-BAHAMAS RIDGE FLATTENS AND SHIFT TO THE SOUTHEAST. A
COLD FRONT ACCOMPANYING THE UPPER TROUGH MOVES INTO THE WESTERN
GULF-SOUTHEAST U.S. AREAS THU THEN THE EASTERN GULF AND ROUGHLY THE
NORTHERN HALF OF FL BY FRI. WHILE THE MODELS HAD BEEN RATHER
CONSISTENT THEY BEGIN TO DIVERGE THU AND FRI. THE GFS IS SLIGHTLY
FASTER AND MORE ROBUST WITH THE RAINFALL WHILE THE ECMWF LAGS BEHIND
AND IS DRIER. FOR NOW WILL MAINTAIN THE CURRENT FORECAST OF SLIGHT
CHANCE TO LOW END CHANCE SHOWERS. TEMPERATURES INITIALLY ABOVE
NORMAL WILL COOL TO NORMAL OR SLIGHTLY BELOW.
&&
.AVIATION...
WIDESPREAD MVFR TO IFR CONDITIONS ACROSS WEST-CENTRAL AND SOUTHWEST
FLORIDA EARLY THIS MORNING...AND CONDITIONS ARE LIKELY TO TRANSITION
TO MORE AND MORE IFR CIGS WITH TIME. THESE RESTRICTIONS ARE EXPECTED
TO LINGER INTO THE LATER MORNING HOURS...WITH CIGS SLOWLY RAISING
BACK INTO THE MVFR CATEGORY FOR ALL TERMINALS BEFORE MIDDAY. THE
AFTERNOON SHOULD FEATURE CONTINUED MVFR CIGS FOR THE TERMINALS ALONG
THE I-4 CORRIDOR...WHILE MORE SOUTHERN TERMINALS WILL HAVE A CHANCE
TO BREAK OUT INTO VFR CIGS FOR A WHILE DURING THE LATER AFTERNOON
AND EARLY EVENING HOURS. LOOK FOR SCATTERED SHOWERS THROUGH THE
DAY...HOWEVER RAINFALL IS GENERALLY EXPECTED TO BE LIGHT WITH
LIMITED VISIBILITY RESTRICTIONS. CEILING HEIGHTS SHOULD AGAIN LOWER
AFTER SUNSET THIS EVENING WITH WIDESPREAD MVFR CONDITIONS INTO THE
OVERNIGHT HOURS.
&&
.MARINE...
STRONG HIGH PRESSURE RIDGING DOWN THE EASTERN SEABOARD WILL KEEP THE
LOCAL GRADIENT TIGHT INTO THIS EVENING ACROSS THE EASTERN GULF OF
MEXICO. ADVISORY LEVEL WINDS AND SEAS OVER THE OFFSHORE WATERS EARLY
THIS MORNING WILL END BY THE AFTERNOON HOURS...BUT MAY ONCE AGAIN
BRIEFLY OCCUR THIS EVENING BEFORE THE GRADIENT BEGINS TO RELAX EARLY
SUNDAY MORNING. WINDS AND SEAS SUNDAY AND MONDAY ARE EXPECTED TO
REMAIN BELOW 15 KNOTS...WITH WINDS LOCALLY TURNING ONSHORE EACH
AFTERNOON DUE TO SEABREEZE DEVELOPMENT. HIGH PRESSURE WILL SHIFT
EASTWARD INTO THE ATLANTIC TUESDAY INTO WEDNESDAY ALLOWING WINDS
OVER THE EASTERN GULF TO SHIFT SOUTHEAST AND EVENTUALLY SOUTH WITH
TIME. AS WINDS BECOME MORE SOUTHERLY LATER TUESDAY INTO WEDNESDAY...
THE RISK LOOKS TO INCREASE FOR THE DEVELOPMENT OF SEA FOG OVER THE
NEAR SHORE WATERS AND BAYS.
&&
.FIRE WEATHER...
A CLOUDY DAY ON TAP WITH OCCASIONAL SHOWERS AND SPRINKLES
REGION-WIDE. MIXING HEIGHTS WILL BE SHALLOW KEEPING LDSI VALUES ON
THE LOW SIDE...DESPITE STEADY WINDS IN THE BOUNDARY LAYER. RELATIVE
HUMIDITY VALUES WILL REMAIN WELL ABOVE CRITICAL LEVELS. NO
SIGNIFICANT FIRE WEATHER CONCERNS CONTINUE INTO SUNDAY AND
MONDAY...WITH RELATIVE HUMIDITY VALUES WELL ABOVE CRITICAL LEVELS.
TEMPERATURES WILL BEGIN TO MODERATE ON SUNDAY AND GENERALLY BE ABOVE
AVERAGE FOR THE EARLY PORTION OF NEXT WEEK.
FOG POTENTIAL...PATCHY FOG IS EXPECTED SATURDAY NIGHT INTO EARLY
SUNDAY MORNING...WITH MORE NUMEROUS AREAS OF FOG POSSIBLE SUNDAY
NIGHT INTO MONDAY MORNING...ESPECIALLY ALONG AND TO THE NORTH OF THE
I-4 CORRIDOR. THE FOG MAY BECOME LOCALLY DENSE EARLY MONDAY MORNING
OVER THESE NORTHERN AREAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 70 62 77 64 / 50 30 30 20
FMY 78 66 83 65 / 50 20 30 10
GIF 72 63 80 64 / 60 40 30 20
SRQ 72 63 78 63 / 50 20 20 20
BKV 69 60 78 59 / 50 40 30 10
SPG 69 64 75 65 / 50 30 30 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING
FOR ENGLEWOOD TO TARPON SPRINGS OUT 20 TO 60 NM-TARPON
SPRINGS TO SUWANNEE RIVER OUT 20 TO 60 NM.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT SERVICES...RUDE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
352 AM EST SAT FEB 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM EST SAT FEB 28 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A MORE SPLIT FLOW
OVER NAMERICA WITH UPR MI ON THE SRN FLANK OF A WNW FLOW ON THE SW
FLANK OF ARCTIC BRANCH CLOSED LO DRIFTING OFF THE NEWFOUNDLAND
COAST. SHRTWV RDG APRCHG THRU MN/VERY DRY AIR SHOWN ON LOCAL 00Z
RAOBS /00Z PWATS WERE ARND 0.07 INCH OR 30-35 PCT OF NORMAL/ ARE
RESULTING IN MOCLR SKIES EARLY THIS MRNG. DESPITE DRYNESS OF THIS
AIRMASS AND CHILL WITH 00Z H85 TEMPS IN THE -16 TO -17C RANGE...
STEADY WSW FLOW UNDER THE RATHER TIGHT PRES GRADIENT TO THE N OF HI
CENTER IN THE OH RIVER VALLEY HAS RESTRICTED THE DROP IN TEMP OVER
MUCH OF THE CWA...ESPECIALLY AT THE MORE EXPOSED LOCATIONS NEAR THE
LAKES...WHERE CURRENT TEMPS RANGE FM ZERO TO 10 ABOVE. BUT SOME OF
THE SHELTERED INTERIOR LOCATIONS HAVE SEEN THE MERCURY FALL TO AS LO
AS -15F TO -20F. LOOKING UPSTREAM...HI CLDS ARE STREAMING INTO MN IN
ADVANCE OF A SHRTWV MOVING E INTO NDAKOTA. BUT SINCE THE AIRMASS IN
THE NRN PLAINS IS ALSO QUITE DRY /AREA PWATS ARE UNDER 0.10 INCH AND
THE 00Z H85 AND H7 DEWPT DEPRESSIONS AT BISMARCK WERE 19C AND 30C
RESPECTIVELY/...THERE IS AN ABSENCE OF PCPN ACCOMPANYING THIS
DISTURBANCE.
MAIN FCST CONCERNS IN THE SHORT TERM WL FOCUS ON MAX TEMPS TODAY AND
IMPACT TNGT OF SHRTWV NOW MOVING THRU THE NRN PLAINS.
TODAY...SHRTWV RDG AXIS NOW IN MN IS PROGGED TO PASS THRU THE CWA
THIS AFTN. ACCOMPANYING AREA OF H85-5 RH UNDER 20 PCT WL RESULT IN
SUNSHINE FILTERED AT TIMES BY SOME HI CLDS STREAMING INTO THE AREA
IN ADVANCE OF SHRTWV THAT IS FCST TO REACH NW MN BY 00Z SUN. AS H85
TEMPS REBOUND TO ARND -14C IN THE SW FLOW ARND SFC HI PRES SHIFTING
TOWARD THE MID ATLANTIC STATES...EXPECT MAX TEMPS TO TOP OUT A
COUPLE OF DEGREES HIER THAN OBSVD YDAY...PERHAPS UP TO 25 IN THE
DOWNSLOPE AREAS NEAR LK SUP BTWN MARQUETTE AND BARAGA. THE LOWEST
TEMPS IN THE TEENS ARE LIKELY DOWNWIND OF THE ICE COVERED NRN BAY OF
GREEN BAY/LK MI.
TNGT...SHRTWV OVER NW MN IS PROGGED TO SHIFT E ACROSS NRN LK SUP AND
INTO ONTARIO JUST E OF THE LK BY 12Z ON SUN. SOME DPVA/MODEST DEEP
LYR QVECTOR CNVGC IS FCST TO INFLUENCE UPR MI AHEAD OF THE SHRTWV.
BUT MODEST MSTR INFLOW/ISENTROPIC ASCENT INTO ANTECEDENT BONE DRY
AIRMASS WL GREATLY RESTRICT POPS. IN FACT...MOST OF THE MODELS
INDICATE A MAINLY DRY OVERNGT AND GENERATE ONLY PATCHY LIGHT PCPN.
SEEMS THE BEST CHC FOR PCPN WL BE OVER LK SUP AND PERHAPS DOWNWIND
OF LK MI FM MANISTIQUE TO NEWBERRY. WL RETAIN MENTION OF SCHC
POPS...MAINLY OVERNGT. LO TEMPS TNGT COULD BE TRICKY WITH LINGERING
DRY AIR IN PLACE BEFORE THICKER CLDS ARRIVE. TENDED TO GO HIER WITH
MIN TEMPS IN THE DOWNSLOPE AREAS NEAR LK SUP IN PREVAILING SSW FLOW.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 351 AM EST SAT FEB 28 2015
MAIN ISSUE THIS FORECAST PERIOD WILL BE WIDESPREAD LIGHT TO MODERATE
SNOWFALL POTENTIAL TUESDAY INTO TUESDAY EVENING WITH CONTINUED
MODERATING TEMPERATURES.
SUNDAY THROUGH MONDAY...A SURFACE TROUGH/WEAK COLD FRONT WILL
CONTINUE TO SHIFT EASTWARD AND PASS THROUGH THE CENTRAL AND EASTERN
PORTIONS OF THE UPPER PENINSULA THROUGH THE DAY SUNDAY. MOISTURE
WILL BE SHALLOW AND FAIRLY LIMITED ALONG THE FRONT WITH CONTINUED
WEAK FORCING. THIS WILL TOUCH OFF VERY LIGHT SNOW THROUGH THE DAY
SUNDAY. BEHIND THE FRONT...AN UPPER LEVEL 500MB TROUGH IS POISED TO
SWING ACROSS THE U.P. SUNDAY NIGHT. AS THIS HAPPENS...ENOUGH
MOISTURE WILL REMAIN IN PLACE WITH MINIMAL ADDITIONAL MOISTURE ADDED
FROM THE VERY ICE COVERED LAKE SUPERIOR TO ALLOW A CHANCE OF LAKE
EFFECT SNOW SHOWERS TO DEVELOP FOR WEST TO NORTHWEST WIND FAVORED
LOCATIONS. 850MB TEMPERATURES WILL DROP TO AROUND -15C TO -20C
ALLOWING FOR SUFFICIENT DELTA T VALUES FOR LAKE EFFECT WITH THE
TROUGH AXIS SLIDING ACROSS...BUT LAKE EFFECT INTENSITY/COVERAGE WILL
BE LIMITED TO AREAS THAT BREAKS IN THE ICE COVER OCCUR. THIS IS
ESPECIALLY TRUE NOW THAT THE ICE EXTENT ON LAKE SUPERIOR IS AT 95.55
COVERED...WHICH IS THE MAX FOR THE SEASON TO THIS POINT. ANY LAKE
EFFECT THAT IS ABLE TO DEVELOP SUNDAY NIGHT WILL BE SHORT LIVED AS
MUCH DRIER AIR AND HIGH PRESSURE AT THE SURFACE AND RIDGING ALOFT
PUSH INTO THE UPPER GREAT LAKES REGION DURING THE DAY MONDAY. THIS
WILL ALL MOST AREAS TO SEE MAINLY SUNNY SKIES DURING THE DAY MONDAY
WITH HIGHS IN THE 20S FOR MOST AREAS. THIS IS STILL BE AROUND 5 TO
10 DEGREES BELOW NORMAL...BUT IT WILL DEFINITELY BE WARMER THAN THE
LAST SEVERAL WEEKS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE SURFACE HIGH PRESSURE
SYSTEM WILL BE SHORT LIVED AND WILL SHIFT TO THE LOWER GREAT LAKES
THROUGH MONDAY EVENING...THEN TO THE EASTERN SEABOARD LATE MONDAY
NIGHT. THIS WILL ALLOW A MORE MOIST...SLIGHTLY WARMER...SOUTHERLY
FLOW TO DEVELOP ON THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A
SURFACE LOW PRESSURE SYSTEM IS PROGGED TO DEVELOP ALONG A SHORTWAVE
OVER THE FOUR CORNERS REGION OF THE CONUS. ANOTHER STRONGER WAVE OF
ENERGY IS PROGGED TO PUSH ACROSS CENTRAL CANADA AND WORK TOWARD THE
JAMES BAY AREA. MODEL DIFFERENCES CONTINUE WITH THE PHASING OF THE
TWO SYSTEMS. THE 18Z/27 00Z/28 GFS CONTINUES TO BE MORE PROGRESSIVE
WITH BOTH SYSTEMS AND THE PHASING OF THE SYSTEMS.
ADDITIONALLY...THE GFS INTENSIFIES THE SOUTHERN SYSTEM MORE
AGGRESSIVELY THAN THE LAST TWO RUNS OF THE EC. EVEN THOUGH IT IS
MORE PROGRESSIVE OVERALL...THE LATEST RUNS OF THE GFS ARE SLOWER
WITH BRINGING PRECIP INTO THE AREA THAN IT HAS BEEN OVER THE
PREVIOUS DAYS RUNS...MORE IN LINE WITH THE EC. THE EC 12/27 00Z/28
CONTINUES TO BE MUCH SLOWER WITH THE PHASING...KEEPING THE
PRECIPITATION OUT OF THE AREA UNTIL VERY LATE MONDAY NIGHT INTO
TUESDAY MORNING. THE OVERALL IMPACT...AS FAR AS SNOWFALL
AMOUNTS...WILL LARGELY DEPEND ON HOW AND WHEN THESE SYSTEM MERGE.
EITHER WAY...IT DOES LOOK LIKE MOST OF THE U.P. WILL SEE WIDESPREAD
SNOWFALL THROUGH THE DAY TUESDAY INTO TUESDAY EVENING...WITH THE
HEAVIER SNOWFALL TOTALS EXPECTED ACROSS SOUTH CENTRAL AND THE EAST
HALF OF THE U.P. MODELS AGREE WITH QPF BEING PAINTED OUT ACROSS
THESE AREAS TO THE POINT THAT LIKELY POPS ARE IN ORDER ESPECIALLY
TUESDAY AFTERNOON INTO TUESDAY EVENING
...AGAIN THE AMOUNTS ARE THE MAIN QUESTION AT THIS POINT WITH THE
GFS PLACING AROUND A HALF INCH QPF ACROSS THE AREA AND THE EC
PAINTING AROUND A QUARTER INCH. THIS WOULD GIVE SNOWFALL TOTALS OF
AROUND 1 TO 3 INCHES OVER THE WEST HALF WITH AROUND 2 TO 5 INCHES
OVER THE EAST HALF...AGAIN THESE ARE PRELIMINARY ESTIMATES AND WILL
BE ADJUSTED AS MODELS BEGIN TO COME INTO BETTER AGREEMENT WITH
BETTER SAMPLING OVER TIME. THE FORTUNATE ASPECT OF THIS SYSTEM IS
THAT IT IS FAIRLY QUICK MOVING...WHICH SHOULD HELP TO KEEP SNOWFALL
TOTALS IN CHECK...BUT IT COULD BE SOMEWHAT OF A HASSLE AS THE
HEAVIER SNOW WOULD FALL DURING THE TUESDAY AFTERNOON/EVENING COMMUTE.
WEDNESDAY THROUGH THE REMAINING EXTENDED...BOTH THE EC AND GFS AGREE
ON AN UPPER LEVEL TROUGH AXIS ALONG WITH CONTINUED MOISTURE ACROSS
THE AREA DURING THIS TIME PERIOD. THE COLDER TEMPERATURES ALOFT
ALONG WITH ANY ADDITIONAL MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR
LAKE EFFECT SNOW CHANCES ACROSS PORTIONS OF THE U.P...ESPECIALLY
THROUGH THURSDAY. AGAIN...THE EXACT LOCATION ALONG WITH INTENSITY
WILL BE LARGELY TIED TO ANY BREAKS IN THE ICE COVER ON LAKE
SUPERIOR. THE FAVORED LOCATIONS BASED SOLELY ON WIND WOULD BE FOR
THE WEST TO WEST NORTHWEST WIND FAVORED SNOW BELTS WITH A SURFACE
HIGH PRESSURE SYSTEM PASSING TO THE SOUTH OF THE REGION.
GENERALLY...ANY LAKE EFFECT SNOW SHOULD REMAIN FAIRLY LIGHT...BUT
THIS WILL DEPEND ON ANY BREAKS IN THE ICE ON LAKE SUPERIOR. THURSDAY
NIGHT...THE SURFACE HIGH WILL SHIFT TO THE EAST OF THE AREA AS A
SURFACE TROUGH APPROACHES THE U.P. FROM THE WEST. THIS WILL
EFFECTIVELY TURN WINDS SOUTH TO SOUTHWESTERLY...ENDING ANY LAKE
EFFECT SNOW CHANCES ACROSS THE U.P.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1223 AM EST SAT FEB 28 2015
WITH DRY HIGH PRES DOMINATING...VFR CONDITIONS WILL BE THE RULE AT
KIWD/KCMX/KSAW THRU THIS FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 AM EST SAT FEB 28 2015
NO GALES EXPECTED INTO NEXT WEEK...WITH WINDS NO HIGHER THAN 20 TO
25 KTS. LAKE SUPERIOR REMAINS MOSTLY ICE COVERED AND THOUGH SHIFTING
WINDS WITH A SERIES OF TROUGH PASSAGES MAY CAUSE HOLES TO OPEN IN
THE ICE FROM TIME TO TIME...A CONTINUED DOMINANCE OF ARCTIC AIR WILL
MAINTAIN AN OVERALL EXTENSIVE ICE COVER.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1111 PM MST FRI FEB 27 2015
.AVIATION...
06Z TAF CYCLE
WDSPRD MVFR TO IFR CIGS/VSBYS IN SNOW AND FOG ACROSS FCST AREA REST
OF NIGHT AND INTO AT LEAST SAT MORN...ALTHOUGH LESS SNOW AND
HIGHER CIGS AND VSBY MAINLY SOUTH OF A LINE FROM ROUGHLY RUIDOSO TO
FENCE LAKE. MTS CONTINUOUSLY OBSCD THROUGH AT LEAST SAT MORN.
GENERALLY LOWEST CIGS LIKELY AT SAF...LVS AND FMN. SNOW EXPECTED
TO DIMINISH SOMEWHAT OR BECOME MORE SPOTTY BETWEEN MIDNIGHT AND
DAWN EXCEPT MAY INCREASE A BIT NORTH OF A ROUGHLY SAF TO GUP LINE.
MOST OR ALL OF THE SW HALF OF THE FCST AREA SHOULD IMPROVE TO VFR
CONDITIONS BY LATE MORN OR EARLY AFTN WITH TEMPS RISING ABOVE
FREEZING. SOME MT OBSCURATIONS MAY CONTINUE EVEN INTO THE AFTN.
THESE GENERAL CONDITIONS LIKELY INTO SAT EVE.
43
&&
.PREV DISCUSSION...332 PM MST FRI FEB 27 2015...
.SYNOPSIS...
AN UNSETTLED WEATHER PATTERN CONTINUES OVER NORTHERN AND CENTRAL
NEW MEXICO AS A SERIES OF STORM SYSTEMS PUSH OVER THE REGION. AS
ONE UPPER LEVEL DISTURBANCE DEPARTED THE STATE TO THE EAST THIS
MORNING...ANOTHER ONE IS CURRENTLY ARRIVING FROM THE WEST.
ADDITIONAL SNOW ACCUMULATIONS ARE EXPECTED THIS EVENING AND
OVERNIGHT...PRIMARILY IN NORTHWESTERN TO CENTRAL AND NORTH CENTRAL
PARTS OF NEW MEXICO. INTO SATURDAY AND SUNDAY...ANOTHER POTENT
DISTURBANCE WILL DIVE INTO CALIFORNIA BEFORE SLOWLY SPREADING OVER
NEW MEXICO. A PROLONGED PERIOD OF HIGH ELEVATION SNOW IS EXPECTED
OVER NORTH CENTRAL TO NORTHWESTERN NEW MEXICO
SATURDAY...SUNDAY...AND INTO MONDAY AND TUESDAY. THE HIGHEST SNOW
TOTALS WILL BE FOUND IN THE SAN JUAN OR TUSAS MOUNTAINS NEAR THE
COLORADO BORDER WHERE AN ADDITIONAL ONE TO TWO FEET OF SNOW COULD
ACCUMULATE...PRIMARILY IN THE HIGHER ELEVATIONS ABOVE EIGHT
THOUSAND FEET. RAIN WILL FALL IN LOWER ELEVATIONS DURING THIS
WEEKEND TO EARLY NEXT WEEK PERIOD.
&&
.DISCUSSION...
THE MIDDLE OF A BARRAGE OF UPPER LEVEL DISTURBANCES. NOT MUCH OF A
RESPITE OR LULL IN THE PRECIPITATION WAS OBSERVED THIS MORNING
BEFORE THE NEXT UPSTREAM SYSTEM STARTED SPREADING MORE BATCHES OF
SNOW INTO WETSERN NM. THIS LATTER DISTURBANCE IS A BIT MORE SUBTLE
LOOKING ON WATER VAPOR IMAGERY COMPARED TO ITS
PREDECESSOR...HOWEVER JET DYNAMICS ARE UNDERWAY AND STRENGTHENING
WITH LOTS OF DIVERGENCE ALOFT BEING DEPICTED BY FORECAST MODELS.
THIS SEEMS TO BE QUICKLY COMING TO FRUITION GIVEN LIGHT SNOW THAT
HAS ALREADY ENSUED AND STARTED AGAIN IN CENTRAL TO WESTERN ZONES.
FORECAST MODELS KEEP THIS DIVERGENCE ALOFT PEGGED OVER THE
NORTHWESTERN QUADRANT OF NM TONIGHT...AND QPF IS GENEROUSLY
PAINTED BENEATH. HRRR MODEL IS ALSO QUITE GENEROUS WITH THIS TREND
WITH A FEW MESOSCALE BANDS OF SNOW BEING DEPICTED. THUS...FELT
PRUDENT TO SPATIALLY AND TEMPORALLY EXTEND ADVISORIES/WARNING
WESTWARD AND LONGER RESPECTIVELY. THESE AMENDMENTS WERE MADE AT
NOON AND WILL HOLD FOR NOW.
INTO SATURDAY THE DIVERGENCE SLOWLY DECREASES IN INTENSITY OVER NM
AND THE FLOW ALOFT BEGINS BACKING MORE SOUTHWESTERLY AS A LOW
TAKES SHAPE AND DIVES INTO CA. THIS SHOULD BEGIN A REDUCTION IN
THE COVERAGE OF PRECIPITATION IN SOME LOWER ELEVATION
AREAS...REDUCTION BEING RELATIVE...WHILE OROGRAPHICS BECOME THE
MORE DOMINANT FORCING MECHANISM FOR THE HIGHER TERRAIN. ELEVATIONS
BELOW 7000 FEET WOULD ALSO OBSERVE A QUICK WARMING TREND AS WARM
AIR ADVECTION BEGINS IN THE SOUTHWESTERLY FLOW. THE FORECAST
MODELS MAY BE A BIT TOO HIGH WITH MAX TEMPERATURE GUIDANCE ON THIS
THOUGH...AS THE CLOUD COVER MAY BE SLOW TO ERODE...STUNTING THE
WARMING MORE THAN WHAT IS ADVERTISED BY MODELS. HAVE BUILT IN A
QUICK CHANGEOVER TO RAIN IN THESE LOWER ELEVATIONS BY LATE MORNING
AND INTO THE AFTERNOON...BUT THIS COULD BE A BIT PREMATURE AND
WILL NEED TO BE CLOSELY MONITORED. PRECIPITATION COULD ALSO BEGIN
TO TAKE ON A SHOWERY OR CONVECTIVE NATURE TO IT AS MODELS HAVE
LIFTED INDICES OF 0 TO -1C PROGGED OVER SOME NORTH CENTRAL TO
NORTHWESTERN ZONES SATURDAY AFTERNOON. THIS WOULD ONLY ADD TO SNOW
RATES IN THE HIGHER TERRAIN. THE WINTER HIGHLIGHTS/STATEMENTS IN
THE NORTHWESTERN ZONES DROP OFF SATURDAY MORNING...BUT MAY NEED TO
BE EXTENDED FOR AFOREMENTIONED REASONINGS.
THE PRECIPITATION REALLY FOCUSES TOWARD THE NORTHWESTERN THIRD OF
THE FORECAST AREA INTO SATURDAY NIGHT AND SUNDAY WITH FLOW
CONTINUING TO BACK SLIGHTLY MORE WHILE SPEEDS ALOFT INCREASE. THIS
WILL KEEP STEADY OROGRAPHIC FORCING OVER THE NORTH CENTRAL TO
NORTHWESTERN MOUNTAINS WITH SOME PRONOUNCED PRECIPITATION SHADOWS
DOWNWIND OR NORTHEAST OF CHUSKAS AND OTHER TOPOGRAPHICAL BARRIERS.
THE SOUTHWESTERLY FLOW ALOFT AND RISING PRESSURE HEIGHTS WILL ALSO
KEEP THE WARMER AIR ADVECTING THIS WAY...AND SATURDAY NIGHT`S LOW
TEMPERATURES WILL BE 10 TO 15 DEGREES WARMER THAN TONIGHT`S
READINGS WHILE SUNDAY`S HIGHS RISE ANOTHER 5 TO 15 DEGREES ABOVE
SATURDAY`S HIGHS. THIS WARMING TREND WILL SHIFT SNOWFALL
ACCUMULATIONS UPWARD TO 7500 TO 8500 FEET SUNDAY AFTERNOON. WHILE
THIS WILL LIMIT THE SPATIAL AREA OF SNOWFALL ACCUMULATIONS...THE
PEAKS ABOVE THIS THRESHOLD WILL STILL SEE REMARKABLE SNOW
AMOUNTS...LIKELY ONE TO THREE FEET ON MANY PEAKS ABOVE 8500 FEET
AND CLOSER TO FOUR FEET NEAR THE CO/NM BORDER ABOVE 10000 FEET.
RUNOFF AND SNOW MELT AT LOWER ELEVATIONS WILL ALSO NEED TO BE
MONITORED CLOSELY ON SUNDAY...PERHAPS CREATING HYDROLOGY ISSUES.
AND THE THREAT FOR ACCUMULATION STILL WON`T END THROUGH MONDAY AS
THE UPPER LOW ROUNDS SOUTHERN CA AND DRIVES A PACIFIC FRONT CLOSER
TO NM...EVENTUALLY CROSSING INTO OUR FORECAST AREA MONDAY NIGHT.
THIS FRONTOGENETICAL FORCING IN ITSELF WILL ALSO INDUCE A HEALTHY
SLUG OF PRECIPITATION...POSSIBLY ENHANCED BY A SUBTROPICAL
MOISTURE TAP. THEN A KICKER SHORT WAVE TROUGH WILL DIG ON THE BACK
SIDE OF THIS BEFORE TURNING INTO OLD MEXICO TUESDAY AND EARLY
WEDNESDAY. FINALLY THE CABOOSE IN THE TRAIN OF STORM SPILLS
SOUTHWARD IN STRONG MERIDIONAL FLOW ON WEDNESDAY...UNLOCKING THE
DOOR TO SOME VERY COLD CONTINENTAL POLAR AIR. ONCE THIS SYSTEM
PASSES...A WELCOME DRIER PATTERN SHOULD FOLLOW INTO THURSDAY OF
NEXT WEEK.
52
&&
.FIRE WEATHER...
AN ACTIVE WEATHER PATTERN WILL PERSIST THROUGH THE MIDDLE OF NEXT
WEEK. MOIST WESTERLY FLOW WILL CONTINUE OVER NORTHERN AND CENTRAL
NEW MEXICO TONIGHT AND SATURDAY...ALLOWING WEST FACING HIGHER
TERRAIN LOCATIONS...ESPECIALLY FROM THE WEST CENTRAL TO THE NORTH
CENTRAL...TO CONTINUE PICKING UP SNOW. THE WINDS ALOFT TRANSITION TO
SOUTHWEST SUNDAY INTO MONDAY AS AN UPPER LOW/TROUGH DIG INTO SOCAL
AND ARIZONA. TEMPERATURES WILL WARM IN ADVANCE OF THE LOW...ALLOWING
SNOW LEVELS TO GRADUALLY RISE FROM WHAT THEY ARE THIS AFTERNOON.
SOME COOLER AIR MAY ENTER THE EASTERN PLAINS SUNDAY...BOTH ECMWF AND
GFS AGREE...BUT LOOKS LIKE IT MERELY RETARDS WARMING IN THE PLAINS
FOR ANOTHER DAY RATHER THAN BRINGS ANOTHER SURGE OF MUCH COLDER AIR.
A SPLIT FLOW PATTERN DOMINATES EARLY TO MID NEXT WEEK...PERMITTING A
MUCH COLDER AND DRIER AIR MASS TO SURGE INTO THE EASTERN PLAINS
TUESDAY NIGHT/WEDNESDAY. THIS LOOKS TO BE THE LAST GASP FOR THE
ACTIVE WEATHER AT LEAST FOR THE REST OF NEXT WEEK.
THROUGH EARLY NEXT WEEK...HEAVY SNOW ACCUMULATIONS ARE LIKELY FOR
THE NORTHERN MOUNTAINS. ALTHOUGH SNOW LEVELS ARE FORECAST TO RISE
SUNDAY INTO MONDAY...SOME OF THE HIGHER NORTHERN/WESTERN TERRAIN
WILL CONTINUE TO RECEIVE SNOW...AND SNOW LEVELS OVERALL FALL AGAIN
TUESDAY AS THE UPPER LOW/TROUGH MOVE OVERHEAD AND TO OUR SOUTH.
HIGH TEMPERATURES THROUGH THE MIDDLE OF NEXT WEEK WILL REMAIN BELOW
AVERAGE. VENT RATES WILL BE POOR IN THE EAST SATURDAY AND SUNDAY BUT
GOOD TO EXCELLENT OVER MOST OF THE WEST CENTRAL AND SOUTHWEST DUE TO
INCREASING WINDS AND MIXING HEIGHTS. VENT RATES OVERALL NEXT MONDAY
AND TUESDAY WILL BE EXCELLENT THEN WORSEN SOMEWHAT WEDNESDAY.
EXCELLENT RH RECOVERIES EXPECTED THROUGH THE PERIOD ALTHOUGH MIN RH
VALUES TREND MUCH LOWER WEDNESDAY INTO THURSDAY.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 8 AM MST SATURDAY FOR THE FOLLOWING
ZONES...NMZ502>504-516-518-519-521.
WINTER WEATHER ADVISORY UNTIL 8 AM MST SATURDAY FOR THE FOLLOWING
ZONES...NMZ501-505>507-517.
WINTER STORM WARNING UNTIL 4 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ510>515-527.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1245 AM EST SAT FEB 28 2015
.SYNOPSIS...COLD HIGH PRESSURE OVER THE CENTRAL PLAINS WILL BUILD
INTO THE MID ATLANTIC THROUGH SATURDAY. A COLD FRONT WILL APPROACH
FROM THE NORTHWEST ON SUNDAY AND MOVE INTO THE AREA BY MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
AS OF 950 PM FRIDAY...
GOOD RADIATIONAL COOLING TO START THE NIGHT AS SKIES ARE CLEAR AND
WINDS ARE EITHER LIGHT OR CALM. REGIONAL RAOB ANALYSIS REVEALS
MODEST COLD ADVECTION IN THE LOW-LEVELS (BELOW 850MB) AS ANOTHER
1040MB HIGH IS MOVING EAST ACROSS THE MIDWEST STATES. THE NAM AND
GFS BOTH SHOW RAPID MOISTENING IN THE BOUNDARY LAYER...WITH
SATURATION REACHING UP TO AROUND -8C AND EVEN A LITTLE QPF VIA SOME
SHALLOW FGEN WITH THE INITIAL SURGE OF COLD ADVECTION.
HOWEVER...THIS IS NOT SUPPORTED BY THE LATEST RAP AND HRRR. THE
STRATUS WOULD ESSENTIALLY DEVELOP OVERHEAD...SO THE LACK OF CLOUDS
DEVELOPING UPSTREAM OVER VA ISNT MUCH HELP. THE MOST RECENT NAM AND
GFS FORECAST SOUNDS HAVE TREND SLIGHTLY WARMER IN BOUNDARY LAYER AND
SLOWER WITH THE SATURATION WHICH COULD BE AN INDICATION THAT THEY
HAVE BEEN OVERDONE. SREF MEMBERS ARE PRETTY MUCH SPLIT DOWN THE
MIDDLE. STILL EXPECT SOME STRATUS WITH THE NORTHEAST FLOW BUT MAYBE
MORE PATCHY THAT PREVIOUSLY THOUGHT. WILL LOWER LOWS A DEGREE OR
TWO BASED ON TRENDS...DIPPING TO NEAR 20 IN THE NORTHEAST AND CLOSER
TO 30 IN THE SOUTHEAST.
AS FOR BLACK ICE...DESPITE A DAY OF GOOD MELTING TODAY...THE
POTENTIAL FOR BLACK ICE TONIGHT AND SAT MORNING IS STILL THERE FOR
AREAS THAT RECEIVED THE HEAVIEST SNOW. AFTER COORDINATING WITH
OFFICIALS FROM SEVERAL OF THE HARDEST HIT COUNTIES...WE HAVE DECIDED
TO ISSUE AN ADVISORY FOR BLACK ICE FOR TONIGHT FOR OUR VA BORDER
COUNTIES...AND FOR FORSYTH EAST TO FRANKLIN. WE WILL ALSO ISSUE AN
SPS FOR THE REMAINING COUNTIES THAT GOT LESSER AMOUNTS OF SNOW TO
COVER THE MORE ISOLATED NATURE OF BLACK ICE POTENTIAL.
FOR SATURDAY...COOL HIGH PRESSURE WILL CONTINUE BUILDING SOUTH
DURING THE DAY SATURDAY...RESULTING IN FAIR WEATHER WITH BELOW-
NORMAL TEMPS. HIGHS ONLY IN THE MID 30S. LIKE TODAY...IF THERE IS
LESS CLOUD COVER THAN FORECAST...THE SUN COULD HELP WARM TEMPS
SEVERAL DEGREES HIGHER THAN FORECAST.
SATURDAY NIGHT...FLOW IN THE 925-850 MB LAYER WILL TURN TO THE SW
AND BEGIN ADVECTING MOISTURE UP INTO OUR AREA AS THE 850MB RIDGE
MOVES EAST AHEAD OF THE TROUGH MOVING ACROSS THE UPPER MISS VALLEY.
WITH THE SFC RIDGE AXIS HOLDING FIRMLY IN PLACE ACROSS OUR AREA...
THE SUBSEQUENT OVERRUNNING AND UPGLIDE WILL RESULT IN INCREASING
CLOUDS OVERNIGHT. THERE ARE VARYING SOLUTIONS RIGHT NOW REGARDING
WHEN PRECIP WILL DEVELOP ACROSS OUR AREA...BUT THE PRECIP START TIME
IS IMPORTANT BECAUSE IF IT STARTS EARLY ENOUGH...SAY A FEW HOURS
EITHER SIDE OF SUNRISE...IT MAY BE COLD ENOUGH STILL FOR A VERY
BRIEF PERIOD OF FREEZING RAIN AT THE ONSET OF PRECIP. EVEN IF THE
EARLIER SOLUTIONS WERE TO VERIFY...THE QPF DURING THAT TIME WOULD BE
VERY LIGHT...SO LITTLE IF ANY IMPACTS WOULD BE EXPECTED. IT`S
DEFINITELY WORTH KEEPING AN EYE ON. LOWS IN THE MID TO UPPER 20S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 240 PM FRIDAY...
SURFACE HIGH PRESSURE RIDGING INTO CENTRAL NC FROM THE NORTHEAST
WILL LINGER OVER THE AREA THROUGH SUNDAY...WITH CONTINUED COLD
ADVECTION AND CLOUDY SKIES. HIGHS EXPECTED TO BE MAINLY IN THE UPPER
30S NW TO MID 40S SE. THE SURFACE HIGH WILL BE SUPPRESSED TO THE
SOUTHEAST SUNDAY EVE/NIGHT AS A SURFACE LOW TRAVERSES THE GREAT
LAKES AND ITS ASSOCIATED COLD FRONT PUSHES SE TOWARD THE REGION.
RAINFALL COULD BEGIN AS EARLY AS MONDAY AFT/EVE AHEAD OF THE FRONT
AS WARM MOIST SOUTHWEST FLOW ABOVE THE SURFACE OVERRUNS THE COLD AIR
AT THE SURFACE...PARTICULARLY IN THE WESTERN PORTIONS OF THE AREA...
ALTHOUGH THE GFS IS A BIT MORE EXCITED ABOUT THAT POSSIBILITY THAN
THE ECMWF. THERE WILL HOPEFULLY BE ENOUGH WARM ADVECTION FROM THE
SOUTHWEST AHEAD OF THE FRONT TO KEEP TEMPERATURES ABOVE FREEZING...AS
A NON-DIURNAL TEMPERATURE CURVE IS ANTICIPATED FROM 18Z SUNDAY
THROUGH 00Z TUESDAY. REGARDLESS...FORECAST SOUNDINGS SHOW ENOUGH OF
A WARM NOSE ABOVE THE SURFACE AND LIMITED MOISTURE IN THE ICE
NUCLEATION REGION THAT PRECIPITATION SHOULD BE ALL LIQUID.
TEMPERATURES SHOULD RISE APPROXIMATELY 5 DEGREES OR SO OVERNIGHT
INTO THE UPPER 30S NW TO MID 40S SE BY MONDAY MORNING. BY SUNRISE
MONDAY THE COLD FRONT IS EXPECTED TO BE ON THE DOORSTEP OF CENTRAL
NC...WITH THE BEST RAINFALL CHANCES ACTUALLY ENDING WELL AHEAD OF
THE FRONT. THE MODELS SHOW THE RAINFALL ALONG THE MAIN AXIS OF THE
FRONT DISSIPATING AS IT CROSSES THE MOUNTAINS AND THE FRONT BECOMING
ORIENTED MORE WEST TO EAST THROUGH CENTRAL NC MONDAY AFT/EVE.
DIFFERENCES/UNCERTAINTY IN THE TIMING AND LOCATION OF THE FRONT AS
IT SETTLES SOUTH WILL RESULT IN A FAIRLY BIG MARGIN FOR ERROR IN THE
MAX AND MIN TEMPS AS COLD HIGH PRESSURE BUILDS IN FROM THE NORTH
BEHIND THE FRONT. FOR NOW EXPECT HIGHS AROUND 50 DEGREES NORTH TO
MID 50S SOUTH AND LOWS IN THE LOW 30S NORTH TO UPPER 30S SOUTH.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 310 PM FRIDAY...
A COLORADO LOW IS EXPECTED TO DEVELOP OVER THE MIDWEST EARLY TUESDAY
AS SURFACE HIGH PRESSURE AND NORTHWEST FLOW ALOFT LINGER OVER
CENTRAL NC. THE HIGH WILL SHIFT OFFSHORE TUESDAY AFTERNOON...WITH
WARM MOIST SOUTHERLY RETURN FLOW ADVECTING INTO THE REGION.
SUBSEQUENTLY...THE COLD FRONT WILL LIFT NORTH THROUGH THE AREA AS A
WARM FRONT...WITH THE CHANCE FOR RAIN TO ONCE AGAIN MOVE INTO THE
SOUTHWEST PORTIONS OF THE AREA TUESDAY AFT/EVE AND INTO THE
OVERNIGHT HOURS. ALTHOUGH CONFIDENCE IN TEMPERATURES IS FAIRLY LOW
AT THIS TIME...HIGHS ARE EXPECTED TO BE IN THE MID 40S TO MID 50S
FROM NW TO SE AND WILL AGAIN LIKELY BOTTOM OUT IN THE LATE EVENING
BEFORE GRADUALLY RISING OVERNIGHT TO POTENTIALLY THE LOW 50S NW TO
AROUND 60 DEGREES SE AT SUNRISE WEDNESDAY. THE MODELS STILL DIFFER
QUITE A BIT WITH REGARD TO THE TIMING OF THE FRONT...AND GIVEN THE
HABIT OF THE GFS TO BE A BIT ON THE FAST SIDE...WILL LEAN TOWARD THE
SLOWER SIDE OF THE FROPA TIMING AND THE ASSOCIATED PRE-FRONTAL
RAINFALL. THE GFS BRINGS PRE-FRONTAL CONVECTION INTO THE NW PIEDMONT
AS EARLY AS WEDNESDAY AFTERNOON...WHILE THE ECMWF HOLDS OFF UNTIL
AFTER MIDNIGHT THURSDAY. HIGHEST CHANCES WILL START AROUND 00Z
THURSDAY IN THE NW AND END AROUND 00Z FRIDAY IN THE SE AND DRYING
OUT EVERYWHERE BY FRIDAY AFTERNOON (AS OF THE LATEST RUNS). TEMPS
CONTINUE TO BE LOW CONFIDENCE AS THEY WILL DEPEND STRONGLY ON THE
TIMING OF THE FRONT...BUT WITH THAT BEING SAID HAVE HIGHS WED IN THE
UPPER 50S NW TO LOW 70S SE. LOWS WED NIGHT AND HIGHS THURSDAY
PROBABLY A BIT TOO COOL...LOW 40S NW TO AROUND 50 DEGREES SOUTH AND
UPPER AROUND 50 DEGREES NW TO UPPER 50S SE...RESPECTIVELY. EXPECT A
COOL BUT DRY PERIOD THU NIGHT INTO FRIDAY...LOWS IN THE MID 20S TO
AROUND 30 DEGREES AND HIGHS UPPER 40S TO AROUND 50 DEGREES.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1245 AM SATURDAY...
DEVELOPING NE LOW LEVEL FLOW WILL CAUSE A DECK OF STRATOCU TO
PROGRESS SWWD ACROSS SECTIONS OF THE NORTHERN COASTAL PLAIN AND THE
NORTHERN PIEDMONT OVERNIGHT. BY 10Z...THE STRATOCU WILL LIKELY BE
BANKED UP AGAINST THE BLUE RIDGE AND EXTEND BACK INTO THE TRIAD
REGION. THIS STRATOCU DECK SHOULD DIMINISH IN VICINITY OF THE TRIAD
BY 14Z-15Z. OTHERWISE EXPECT VFR CONDITIONS AND A BRISK NE SFC WIND
THIS MORNING WITH OCCASIONAL GUSTS 15-18KTS BETWEEN 10Z-18Z. THIS
FLOW WILL DEPOSIT A COLD DRY AIR MASS ACROSS THE REGION
TODAY...LINGERING INTO EARLY SUNDAY.
AN AREA OF LOW PRESSURE WILL APPROACH FROM THE SOUTHWEST LATE
TONIGHT INTO SUNDAY. SLY FLOW A FEW THOUSAND FEET ABOVE THE COLD
STABLE AIR MASS AT THE SURFACE WILL PULL WARM MOIST AIR INTO THE
REGION. THIS WILL CAUSE WIDESPREAD LOW CLOUDS TO DEVELOP ALONG WITH
A AREAS OF LIGHT PRECIPITATION. WITH NEAR SURFACE TEMPS EXPECTED TO
BE NEAR OR SLIGHTLY BELOW FREEZING...THE PRECIPITATION WILL LIKELY
START OUT AS FREEZING RAIN SUNDAY MORNING THEN TRANSITION TO RAIN AS
SFC TEMPS WARM TO ABOVE FREEZING BY MID DAY-EARLY AFTERNOON. THE
FREEZING PRECIPITATION WILL LAST LONGEST OVER THE NORTHERN
PIEDMONT...AND THE LEAST IN VICINITY OF KFAY.
A COLD FRONT WILL CROSS THE REGION MONDAY...FOLLOWED BY AN AREA OF
HIGH PRESSURE AND ITS ASSOCIATED VFR CONDITIONS. ANOTHER LOW
PRESSURE SYSTEM WILL CAUSE ANOTHER PERIOD OF SUB VFR CONDITIONS LATE
TUESDAY INTO WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FOR
BLACK ICE IN EFFECT THROUGH 10 AM EST THIS MORNING FOR NCZ007>011-
021>026-041.
&&
$$
SYNOPSIS...RAH
NEAR TERM...RAH/BLS
SHORT TERM...KC
LONG TERM...KC
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1237 AM EST SAT FEB 28 2015
.SYNOPSIS...
HIGH PRESSURE WILL WEDGE DOWN THE COAST THIS WEEKEND. DRY BUT CHILLY
WEATHER IS EXPECTED ON SATURDAY. RAIN CHANCES WILL INCREASE SUNDAY
AS TEMPERATURES MODERATE. A COLD FRONT WILL CROSS THE AREA MONDAY
ACCOMPANIED BY SHOWERS. SEASONABLE WEATHER IS EXPECTED TUESDAY
BEFORE THIS FRONT LIFTS NORTH AS A WARM FRONT WEDNESDAY...BRINGING
ONE DAY OF WELL ABOVE NORMAL TEMPERATURES. ANOTHER COLD FRONT WILL
APPROACH WEDNESDAY NIGHT OR THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 945 PM FRIDAY...SUBTROPICAL JET STREAM MOISTURE CONTINUES OVER
THE COASTAL CAROLINAS...WITH UPSTREAM SATELLITE TRENDS INDICATING
THE WESTERN EDGE OF THIS CLOUD DECK MAY NOT DRIFT OFFSHORE AFTER
ALL. NORTHEAST WINDS ARE FIRMLY ESTABLISHED AT THE SURFACE...
ALTHOUGH WIND SPEEDS HAVE YET TO RAMP UP WITH THE COLD AIR SURGE
EXPECTED TO BEGIN AROUND MIDNIGHT. RECENT RUC AND HRRR MODEL TRENDS
HAVE BEEN UPWARD WITH LOW TEMPERATURES TONIGHT AND I HAVE MADE
UPWARD TWEAKS AT MOST LOCATIONS: 27-31 ACROSS SE NORTH CAROLINA AND
29-32 OVER NE SOUTH CAROLINA...WARMEST AT THE COAST. DISCUSSION FROM
630 PM FOLLOWS...
ONLY MINOR CHANGES MADE TO THE NEAR TERM FORECAST THIS EVENING. THE
LEADING EDGE OF A NE SURGE CURRENTLY DROPPING SOUTH ACROSS THE
CHESAPEAKE BAY WILL REACH OUR AREA AFTER MIDNIGHT. THE BIGGEST
QUESTION REMAINS HOW MUCH (IF ANY) LOW CLOUDINESS DEVELOPS IN THE
NORTHEASTERLY LOW-LEVEL FLOW BEHIND THE SURGE? 18Z NAM AND GFS MODEL
OUTPUT SHOW ENOUGH MOISTURE IN THE LOWEST 1000 FEET OF THE
ATMOSPHERE DEVELOPING OVERHEAD BETWEEN 09-12Z (4-7 AM) TO PRODUCE
LOW CLOUDS. A LOCAL RULE OF THUMB IS TO LOOK AT
CONVERGENCE/DIVERGENCE WITHIN THE MOISTURE-BEARING LAYER TO HELP
DIAGNOSE THE POTENTIAL FOR LOW CLOUDINESS -- AND ALL MODELS SHOW
DIVERGENCE ON THE 1000 MB SURFACE TONIGHT. FOR THIS REASON I HAVE
REDUCED THE AMOUNT OF FORECAST CLOUDINESS LATE TONIGHT...
ANTICIPATING MAINLY 300 MB CIRRUS MOISTURE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...DEVELOPING COLD WEDGE THIS WEEKEND WILL KEEP
SKIES CLOUDY AND HOLD HIGHS 10 TO 20 DEGREES BELOW CLIMO. WEAKLY
AMPLIFIED MID LEVEL PATTERN WILL CONTINUE TO PUMP MOISTURE INTO THE
SOUTHEAST. SOUTHWEST FLOW ALOFT COMBINED WITH LOW LEVEL NORTHEAST
FLOW WILL MAINTAIN WEAK ISENTROPIC LIFT FOR MUCH OF THE PERIOD BUT
LOW LEVEL DRY AIR HOLDING ON SAT AND MOST OF SAT NIGHT WILL KEEP THE
REGION DRY FOR THE FIRST HALF OF THE WEEKEND. LOW LEVELS MOISTEN UP
SUN MORNING WITH LIGHT RAIN SPREADING OVER THE AREA AS COASTAL
TROUGH DEVELOPS OFFSHORE. LATER SUN MID LEVEL RIDGE EXPANDING NORTH
FROM THE GULF OF MEXICO STARTS TO WEAKEN THE WEDGE...LESSENING
ISENTROPIC LIFT. WEDGE COMPLETELY BREAKS DOWN SUN NIGHT WITH LIGHT
WESTERLY FLOW DEVELOPING AFTER MIDNIGHT. ALTHOUGH NORTHERLY FLOW
CONTINUES AT THE SURFACE DURING SUN THERE WILL BE SOME MODEST WARM
ADVECTION JUST ABOVE THE BOUNDARY LAYER. THIS WILL HELP PUSH HIGHS
ON SUN CLOSER TO CLIMO...THOUGH TEMPS WILL ULTIMATELY FALL 5 TO 10
DEGREES SHORT. CLOUD COVER WILL HELP KEEP LOWS NEAR FREEZING SAT
NIGHT. WARM ADVECTION ALONG WITH CLOUDS WILL KEEP LOWS NEAR CLIMO
SUN NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 330 PM FRIDAY...COLD FRONT WILL MAKE ITS WAY OFF SHORE MONDAY
AS HIGH PRESSURE BUILDS DOWN FROM THE NORTHWEST TO NORTH. DEEPER
WESTERLY FLOW EARLY MONDAY WILL BECOME NW AS SHORTWAVE MOVES OFF TO
THE E-NE THROUGH LATE MONDAY. THEREFORE...INITIALLY THE DOWNSLOPE
FLOW AND SOME BREAKS OF SUNSHINE SHOULD PUSH TEMP UP AROUND 60 ON
MONDAY. BY LATER ON MONDAY A DEEPER NW FLOW WILL INCREASE CAA
BRINGING 850 TEMPS FROM CLOSE TO 10C EARLY MON DOWN TO 4 C BY TUES
MORNING. THE WINDS WILL SHIFT AROUND BECOMING MORE NORTHERLY
OVERNIGHT AND MORE ON SHORE BY TUES AFTN. INCREASING CLOUD COVER
AND WINDS MON NIGHT SHOULD KEEP TEMPS ABOVE NORMAL.
A RIDGE IN THE MID TO UPPER LEVELS WILL PUSH UP FROM THE GULF MON
NIGHT INTO TUES AND WILL SHARPEN AS TROUGH DIGS DOWN THROUGH THE MID
WEST BY WED. AT THE SAME TIME THE SFC HIGH TO THE NORTH WILL MOVE
OFF SHORE THROUGH TUES AND RIDGE TO THE SOUTH WILL HELP PUSH COLD
FRONT BACK NORTH AS WARM FRONT. A BRIEF WEDGE WILL DEVELOP WITH
INCREASING ISENTROPIC LIFT AS WARM FRONT MOVES NORTH INTO SHALLOW
RELATIVELY COOLER AIR IN PLACE ON TUES. EXPECT CLOUDS AND CHC OF PCP
ON TUES AS WARM FRONT LIFTS NORTH. WILL KEEP A LARGER TEMP RANGE IN
TIGHTENED GRADIENT BETWEEN COOL TEMPS TO THE NORTH AND WARMER TEMPS
TO THE SOUTH ON TUES BEFORE WARM FRONT LIFTS BY END OF DAY. TUES
NIGHT WILL HAVE NEAR STEADY OR RISING TEMPS IN WAA BEHIND FRONT.
COASTAL CAROLINAS WILL BE IN WARM AND MOIST AIR MASS ON WED AHEAD OF
APPROACHING COLD FRONT. TEMPS SHOULD SOAR INTO THE 70S MOST PLACES
EXCEPT CLOSER TO THE COAST WHERE COOLER OCEAN TEMPS WILL KEEP THE
AIR COOLER. ALTHOUGH CLOUDS WILL LIMIT WARMING...SOME BREAKS MAY
PUSH TEMPS HIGHER IN A FEW PLACES. ECMWF IS MUCH SLOWER WITH COLD
FRONT WHILE GFS BRINGS IT THROUGH BY MIDNIGHT WED NIGHT. FOR NOW
WILL HEDGE TOWARD SLOWER FROPA AND KEEP TEMPS WARMER WED NIGHT AND
WILL BRING FRONT THROUGH EARLIER ON THURS WITH TEMPS COOLING IN CAA
THROUGH THURS INTO FRI. IF FRONT COMES EARLIER THAN SHOWERS WILL BE
MORE WIDESPREAD ON WED AFTN AND EVENING. OVERALL EXPECT INCREASING
SHOWERS AHEAD OF FRONT. EXPECT TEMPS BELOW NORMAL AGAIN LATE THURS
INTO FRI AS COLD AND DRY HIGH PRESSURE BUILDS IN.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...VFR EXPECTED THROUGH THE VALID TAF PERIOD AS HIGH
PRESSURE CONTINUES TO BUILD IN...WITH POSSIBLE MVFR ALONG THE COAST
TOWARDS THE END OF THE PERIOD.
LATEST SATELLITE IMAGERY DEPICTS A SWATH OF SCT HIGH CLOUDS ACROSS
THE AREA. THIS WILL PERSIST THROUGH THE OVERNIGHT HOURS AND ALLOW
FOR VFR TO PREVAIL WITH LIGHT NORTHEAST WINDS. AFTER
DAYBREAK...EXPECT A GRADUAL TIGHTENING OF THE PRESSURE GRADIENT
WHICH WILL BRING AN INCREASE IN NORTHEAST WINDS...SUSTAINED AOB 15
KTS AND GUSTS UP TO AROUND 20 KTS. MOISTURE WITHIN THE ATMOSPHERIC
COLUMN IS FORECAST TO INCREASE AS WELL YIELDING INCREASING MID TO
HIGH CLOUDS DURING THE DAYLIGHT HOURS TODAY. INTO THE EVENING
HOURS...THERE IS THE POSSIBILITY OF LOWERING CIGS ALONG THE COAST
WHICH COULD CREATE MVFR.
EXTENDED OUTLOOK...MVFR/IFR POSSIBLE LATE SUNDAY THROUGH TUESDAY AS
A WEDGE SETS UP. WINDY WEDNESDAY WITH POSSIBLE SHOWERS WEDNESDAY
NIGHT. OTHERWISE EXPECT VFR.
&&
.MARINE...
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 PM FRIDAY...WINDS AND SEAS ARE RAMPING UP MORE SLOWLY THAN
ANTICIPATED...DELAYING THE ONSET OF SMALL CRAFT ADVISORY CONDITIONS.
UPSTREAM OBSERVATIONS ACROSS THE OUTER BANKS AND NORTHEASTERN NORTH
CAROLINA CONTINUE TO SUPPORT THE IDEA OF STRONGER WINDS MOVING INTO
THE AREA OVER THE NEXT FEW HOURS. THERE IS LITTLE SPREAD IN MODEL
GUIDANCE LENDING HIGH CONFIDENCE THAT WE WILL EVENTUALLY SEE THESE
DETERIORATING CONDITIONS DEVELOP. DISCUSSION FROM 630 PM FOLLOWS...
NO SIGNIFICANT CHANGES ARE NEEDED TO THE FORECAST WITH THIS
EARLY-EVENING UPDATE. FORECAST WIND SPEEDS HAVE BEEN REDUCED BY 3-5
KNOTS BASED ON OBSERVATIONS THROUGH THE EVENING...WITH INCREASING
SPEEDS EXPECTED OVERNIGHT AS THE PRESSURE GRADIENT TIGHTENS UP ON
THE SOUTH EDGE OF HIGH PRESSURE.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...SURFACE HIGH WEDGING DOWN THE EAST COAST WILL
MAINTAIN A PINCHED GRADIENT OVER THE WATERS SAT AND SAT NIGHT.
NORTHEAST FLOW WILL BE SOLIDLY IN THE 20 TO 25 KT RANGE WITH SEAS 4
TO 8 FT SAT. ONLY EXCEPTION WILL BE LOCATIONS WHERE NORTHEAST FLOW
IS OFFSHORE. IN THESE LOCATIONS NEAR SHORE SEAS WILL RUN 1 TO 3 FT.
GRADIENT STARTS TO RELAX LATE SAT NIGHT AS COASTAL TROUGH TAKES
SHAPE AND HIGH STARTS TO WEAKEN. WINDS DROP UNDER 20 KT EARLY SUN
MORNING AND BY AFTERNOON WILL BE 10 KT OR LESS. REDUCTION IN
NORTHEAST FLOW WILL ALLOW SEAS TO DROP AND BY DAYBREAK SUN SEAS
SHOULD BE 3 TO 5 FT AND 2 TO 4 FT BY THE END OF THE PERIOD.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...A COLD FRONT WILL DROP TOWARDS...AND THEN
ACROSS...THE WATERS DURING MONDAY PRODUCING VARIABLE WINDS THAT WILL
VEER FROM SW EARLY MONDAY...TO NE BY TUESDAY MORNING. THE GRADIENT
REMAINS RATHER WEAK DURING THIS TIME HOWEVER...SO SPEEDS WILL BE
LESS THAN 15 KTS THROUGH THE DAY. THIS FRONT WILL STALL SOUTH OF THE
WATERS THE FIRST HALF OF TUESDAY...MAINTAINING THE NE WINDS...BEFORE
LIFTING RAPIDLY BACK NORTH AS A WARM FRONT LATE TUESDAY. WINDS WILL
AGAIN VEER THROUGH HALF THE COMPASS...BECOMING SW AND RISING TO
15-20 KTS LATE. SEAS OF 2-4 FT WILL BE COMMON MONDAY AND THE FIRST
HALF OF TUESDAY...ALTHOUGH COMPRISED BY A VARIETY OF WIND WAVES
WHICH WILL FOLLOW THE PRIMARY WIND DIRECTION. THIS WILL LIKELY
CREATE PERIODS OF CONFUSED WAVE STATES DURING MONDAY AND TUESDAY.
LATE TUESDAY SEAS BUILD TOWARDS 6 FT...AND AN SCA MAY BE REQUIRED AT
THE END OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 5 AM EST
SUNDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...RGZ
AVIATION...SGL/31
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
318 AM CST SAT FEB 28 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 315 AM CST SAT FEB 28 2015
FORECAST CHALLENGES CONCERN TEMPERATURES AND LOW END SNOW CHANCES.
MAIN MODEL DIFFERENCES WILL BE -SN POTENTIAL WITH WEAK WAVE
PASSAGES AND WILL USE A BLEND.
SEVERAL WEAK WAVES WILL ROTATE THROUGH BASE OF NORTHERN STREAM MID
LEVEL TROUGH THIS WEEKEND. FIRST OF THESE FEATURES AND ASSOCIATED
SURFACE TROUGH MOVING INTO WESTERN ND WILL PROPAGATE EAST ACROSS
FA LATER TODAY AND TONIGHT. ECMWF CONTINUES TO BE WEAKEST WITH -SN
POTENTIAL. AT THIS POINT IT LOOKS TO BE THE ODD MODEL OUT AS
GFS/GEM/NAM ALL SHOWING BETTER SNOW POTENTIAL ALBEIT LIGHT MAINLY
THIS EVENING. RUC ALSO DEVELOPING -SN FROM VALLEY EASTWARD LATE
THIS AFTERNOON INTO THE EVENING. WITH RUCS SPOTTY NATURE OF
POSSIBLE -SN HESITANT TO RAISE POPS TOO FAR AND KEPT WITHIN CHANCE
RANGE. LOW LEVEL WARM ADVECTION WILL CONTINUE AHEAD OF TROUGH AND
WILL BE STARTING OUT ABOUT 10 DEGREES WARMER THAN YESTERDAY.
SATELLITE IMAGERY/SFC OBS INDICATING BKN SC DECK ACROSS CENTRAL-
WESTERN ND WHICH SHOULD MOVE IN TODAY WHICH MAY HAVE AN IMPACT ON
DEGREE OF WARMING. FOR THIS WAS CONSERVATIVE ON MAXIMUM
TEMPERATURES. ANY -SN THIS EVENING OVER NW MN SHOULD EXIT FA TO
THE EAST AFT MIDNIGHT. OVERALL LOOKING A HALF INCH OR SO OF
POTENTIAL ACCUMULATION. CLOUDS WILL ALSO HAVE A BEARING ON MINIMUM
TEMPERATURES TONIGHT.
A WEAKER WAVE WILL AFFECT FA ON SUNDAY. SURFACE FEATURES ALSO
WEAKER SO LIKELY LOOKING AT MAINLY FLURRIES BUT DID INTRODUCE SOME
LOW POPS OVER NW MN LATE IN THE AFTERNOON. FOLLOWED PERSISTENCE
WITH TEMPERATURES AS CLOUDS AND HOW COLD WE START OUT IN THE MORNING
WILL IMPACT MAX TEMPERATURES.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 AM CST SAT FEB 28 2015
HIGH PRESSURE WILL SHIFT ACROSS CENTRAL PLAINS SUNDAY NIGHT. WITH
HIGH CENTER TO OUR SOUTH W-SW SURFACE FLOW AND WARM ADVECTION WILL
LIMIT TEMPERATURE DROP AND SHOULD SEE MINS A FEW DEGREES EITHER
SIDE OF ZERO.
BRISK SOUTHERLY FLOW AND CONTINUED WARM ADVECTION MONDAY SHOULD
ALLOW TEMPERATURES TO FINALLY APPROACH SEASONAL AVERAGES.
MAINTAINED LOW POPS MONDAY NIGHT WITH APPROACH OF NEXT WAVE AND
COLD FRONT ALTHOUGH MODELS NOT IN VERY GOOD AGREEMENT. BASED ON
TIMING OF COLD FRONT BOUNDARY LOOKS TO BE THROUGH ALL BUT THE FAR
SE BY MORNING. THIS COULD SET UP RESPECTABLE TEMPERATURE CONTRAST
ACROSS THE FA WITH COLDEST MINIMUMS ACROSS THE NW DEEPER IN THE
COLDER AIR.
A BREEZY TO WINDY EXTENDED PERIOD LOOKS TO BE SHAPING UP AS ARCTIC
BOUNDARY PUSHES THROUGH THE FORECAST AREA EARLY TUESDAY SWINGING
WINDS FROM SW TO NNW. CAA BEHIND BOUNDARY WILL MAKE WEDNESDAY THE
COLDEST OF THE BUNCH WITH AREA WIDE HIGHS ONLY IN THE POSITIVE
SINGLE INTEGERS. GFS/ECMWF ARE CLOSE WITH 850 MB TEMPS PEGGING A
CORE OF -20 TO NEAR -30C INTO AND THROUGH THE NORTHERN VALLEY. ASIDE
FROM A PERIOD OF LIGHT SNOW/SNOW SHOWERS FOR WC MN TUE AFTN THE
ENTIRETY OF THE EXTENDED IS ESSENTIALLY POP FREE. UPPER FLOW BECOMES
MORE ZONAL THUR INTO FRI AND AS SURFACE HIGH DRIFTS SOUTH AND
SOUTHEAST EXPECT THERMAL RECOVERY TO NEAR AVERAGE VALUES BY
FRI...MAXES FROM THE UPPER 20S TO LOW 30S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1149 PM CST FRI FEB 27 2015
NO CHANGE IN THINKING WITH THIS ISSUANCE. VFR CONDITIONS EXPECTED
INTO SATURDAY EVENING. HIGH CLOUDS TONIGHT...WITH GRADUALLY
LOWERING CIGS ON SATURDAY. WINDS SHOULD REMAIN BELOW 12
KNOTS...GENERALLY FROM A SOUTHERLY DIRECTION.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...VOELKER
LONG TERM...WJB/VOELKER
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1233 AM CST SAT FEB 28 2015
.UPDATE...
ISSUED AT 1232 AM CST SAT FEB 28 2015
ONLY MINOR UPDATES WERE MADE TO OVERNIGHT LOW TEMPERATURES AND SKY
COVER FOR THIS UPDATE.
COLDEST AIR IS LAGGING BEHIND THE COLD FRONT CURRENTLY DRAPED
ACROSS NORTHWEST NORTH DAKOTA. WITH CLOUD COVER AND MODERATE
WINDS...LOW TEMPERATURES MAY STRUGGLE TO DROP NEAR OR BELOW ZERO
TONIGHT ACROSS MOST OF THE AREA. THEREFORE...INCREASED OVERNIGHT
LOWS ACROSS MOST OF THE AREA. WARMEST TEMPERATURES EXPECTED ACROSS
THE SOUTH AS THE COLD FRONT WILL NOT LIKELY MAKE IT THROUGH UNTIL
THE LATE MORNING HOURS. ALSO INCREASED SKY COVER ACROSS WESTERN
NORTH DAKOTA EARLY THIS MORNING AS FAIRLY WIDESPREAD CLOUD COVER
WAS EXPANDING INTO WESTERN AND CENTRAL NORTH DAKOTA.
UPDATE ISSUED AT 933 PM CST FRI FEB 27 2015
A WEAK COLD FRONT IS SITUATED ALONG THE MONTANA BORDER AT 03 UTC
THIS EVENING. AHEAD OF THE FRONT SOUTHERLY FLOW CONTINUES. WITH
INCREASING MOISTURE TRANSPORT...AREAS OF MID LEVEL CLOUDS HAVE
DEVELOPED ALONG AND AHEAD OF THE FRONT AND ARE LIFTING NORTHEAST
ACROSS WESTERN AND CENTRAL NORTH DAKOTA. OVER THE FAR EAST
TEMPERATURES HAVE FALLEN TO NEAR ZERO. LATEST 02 UTC RAP SHOWS THE
STRONGER LOW LEVEL WARM ADVECTION MOVING INTO THIS AREA BY AROUND
MIDNIGHT SO THINK TEMPERATURES HERE MAY FALL A FEW DEGREES BEFORE
LEVELING OFF. IN THE WEST TEMPERATURES ARE VARYING GREATLY
DEPENDING ON WHERE THE MID LEVEL CLOUDS ARE. IN GENERAL...HAVE
LOWERED TEMPERATURES OVER THE SOUTHEAST A COUPLE OF DEGREES AND
HAVE RAISED TEMPERATURES IN THE SOUTHWEST A COUPLE OF DEGREES.
EVEN THOUGH WE ARE IN THE TEENS OUT WEST...WE SHOULD SEE SOME COLD
ADVECTION DEVELOP BEHIND THE FRONT LATE TONIGHT...DROPPING THEM
CLOSE TO FORECAST LOWS. OVERALL A TRICKY TEMPERATURE FORECAST
TONIGHT. DID BUMP UP SKY COVER A LITTLE MORE BASED ON THE
INCREASING MID LEVEL CLOUDS.
UPDATE ISSUED AT 604 PM CST FRI FEB 27 2015
NO CHANGES FOR THE EARLY EVENING UPDATE. THIN HIGH CLOUDS MOVING
IN FROM THE WEST. SHOULD SEE AN INCREASE IN CLOUDS LATER TONIGHT
AS A WEAK FRONTAL BOUNDARY MOVES INTO NORTHWEST NORTH AROUND
MIDNIGHT AND MAKING ITS WAY INTO CENTRAL NORTH DAKOTA BY SATURDAY
MORNING.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 322 PM CST FRI FEB 27 2015
SUNNY SKIES AND SOUTHERLY/SOUTHWESTERLY WINDS WILL CONTINUE
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE AFTERNOON AS
HIGH PRESSURE SHIFTS EAST OF THE REGION.
A WEAK DRY COLD FRONT IS PROGGED TO ENTER WESTERN NORTH DAKOTA
AROUND MIDNIGHT...THEN PUSH INTO CENTRAL NORTH DAKOTA BY SATURDAY
MORNING. THE ONLY NOTICEABLE IMPACT WILL BE A WIND SHIFT TO
NORTHWESTERLY IN THE WAKE OF THE FRONT. GIVEN THE WEAK NATURE OF
THE BOUNDARY...NOT MUCH WIND IS EXPECTED. TEMPERATURES WILL ONCE
AGAIN BE BELOW NORMAL...RANGING FROM THE TEENS TO 20S BY SATURDAY
AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 322 PM CST FRI FEB 27 2015
THE MAIN LONG TERM HIGHLIGHT IS ANOTHER CHUNK OF ARCTIC AIR MONDAY
NIGHT AND CONTINUING THROUGH WEDNESDAY NIGHT WITH DANGEROUS WIND
CHILL TEMPERATURES ONCE AGAIN DEVELOPING. PRECIPITATION PROSPECTS
THROUGH THE LONG TERM REMAIN REMAIN SLIM TO NONE. THE PREVIOUS
TREND OF A GRADUAL MODERATING TREND LATE IN THE EXTENDED REMAINS
ON TRACK.
FOR SATURDAY NIGHT AND SUNDAY...ANOTHER UPPER LOW SHIFTS INTO
HUDSON BAY ALLOWING THE PERSISTENT LONGWAVE TROUGH ACROSS THE
GREAT LAKES AND RESULTANT NORTHWEST FLOW INTO NORTH DAKOTA TO
PERSIST. A SHORTWAVE TROUGH WILL ROTATE AROUND THE AFOREMENTIONED
HUDSON BAY LOW SATURDAY NIGHT AND SLIDE INTO SASKATCHEWAN. THIS
WILL SUPPORT A WEAK SURFACE COLD FRONT TO PASS THROUGH FROM WEST
TO EAST...06Z SUNDAY THROUGH 00Z MONDAY. PRECIPITATION POTENTIAL
IS MEAGER...WITH WEAK/SHALLOW LIFT ALONG THE SURFACE COLD FRONTAL
AS WELL AS THE SHORTWAVE TROUGH PASSAGE. THUS ONLY EXPECT A SLIGHT
CHANCE OF SNOW SATURDAY NIGHT NORTHWEST AND FAR NORTH CENTRAL WITH
THE FRONTAL PASSAGE...FOLLOWED BY FLURRIES SUNDAY WITH THE
SHORTWAVE TROUGH.
FOR SUNDAY NIGHT AND MONDAY...A BRIEF TRANSITORY RIDGE SUNDAY
NIGHT WILL BE FOLLOWED BY A SURFACE WARM FRONTAL FRONTAL SYSTEM
THROUGH WESTERN AND CENTRAL NORTH DAKOTA MONDAY. RISING H85
TEMPERATURES AND CORRESPONDING SURFACE HIGHS WILL BRIEFLY RESULT
IN AFTERNOON HIGH TEMPERATURES IN THE 30S WEST AND SOUTH
CENTRAL...AND 20S FARTHER NORTH AND EAST. AN ARCTIC FRONT PUSHES
INTO NORTHWEST NORTH DAKOTA JUST PRIOR TO 00Z TUESDAY.
MONDAY NIGHT THROUGH WEDNESDAY NIGHT...THE AFOREMENTIONED ARCTIC
FRONT QUICKLY SWEEPS THROUGH CENTRAL NORTH DAKOTA BY 06Z TUESDAY
WITH AS A TIGHT BAROCLINIC ZONE SHIFTING THROUGH. A MINOR THREAT
FOR A BRIEF SNOWSHOWER ALONG THE FRONT AS IT SLIPS THROUGH
OTHERWISE THE MAIN HIGHLIGHT WILL BE INCREASING WINDS AND COLD AIR
ADVECTION. 6HR PRESSURE RISES OF 12MB PER GFS PUSH INTO NORTHWEST
NORTH DAKOTA BY 06Z TUESDAY...THEN WEAKEN SLIGHTLY ACROSS THE REST
OF WESTERN AND SOUTH CENTRAL NORTH DAKOTA LATE MONDAY
NIGHT/TUESDAY MORNING. GFS BUFKIT SOUNDINGS AT KDIK AND KBIS
INDICATE COLD AIR ADVECTION COMMENCING AFTER MIDNIGHT WITH THE
ONSET OF A DEEPENING MIXED LAYER. THE MAGNITUDE OF THE MIXED LAYER
WINDS ARE 30KT WITH NEAR 40KT AT THE TOP. DESPITE HIGHER MIXING
HEIGHTS DURING THE DAYLIGHT HOURS TUESDAY...WIND SPEEDS REMAIN
SIMILAR TO LATE MONDAY NIGHT. A CONSIDERATION FOR A LOW-END WIND
ADVISORY WILL BE REVISITED IN FUTURE MODEL RUNS AS WE GET CLOSER.
WITH CYCLONIC FLOW AND SUCCESSIVE SHORTWAVES TO PUSH
THROUGH...PARTLY TO MOSTLY CLOUDY CONDITIONS DOMINATE MONDAY NIGHT
THROUGH WEDNESDAY NIGHT.
IN TERMS OF TEMPERATURES...THE COLDEST CHUNK OF AIR ARRIVES LATE
TUESDAY THROUGH WEDNESDAY. THE NORTH AMERICAN ENSEMBLE FORECAST
PERCENTILE TABLE SHOWS H85 TEMPS OF -24C COVERING MOST OF WESTERN
AND CENTRAL NORTH DAKOTA TUESDAY NIGHT THROUGH WEDNESDAY. IN FACT
THE H85-H50 COLUMN ADVERTISES VALUES NEAR OR AT THE MIN WITH
RESPECT TO CLIMATOLOGY. THIS INDICATES THE ENSEMBLE IS FORECASTING
TEMPERATURES FALLING OUTSIDE THE 1979-2009 CLIMATOLOGY FOR THIS
TIME OF YEAR. NORTHWEST WINDS TUESDAY NIGHT INTO WEDNESDAY WILL
REMAIN AT 10 TO 20 MPH AS THE SURFACE HIGH STILL RESIDES OVER
WESTERN SASKATCHEWAN. WITH MIXING...IN COMBINATION WITH PARTLY TO
MOSTLY CLOUDY SKY CONDITIONS...EXPECT MINIMUM TEMPERATURES IN THE
5 BELOW TO 15 BELOW RANGE AS OPPOSED TO A POTENTIALLY COLDER
SCENARIO OTHERWISE. THE BRISK WINDS WILL HOWEVER ALLOW WIND CHILL
TEMPERATURES TO REACH THE 25F BELOW TO 39F BELOW RANGE TUESDAY
NIGHT THROUGH WEDNESDAY MORNING OVER ALL BUT THE FAR SOUTHWEST.
HIGHS WEDNESDAY WILL RANGE FROM ZERO NORTHEAST TO 15 ABOVE
SOUTHWEST.
THURSDAY THROUGH FRIDAY...SURFACE HIGH QUICKLY SLIDES THROUGH
WEDNESDAY NIGHT WITH LOW LEVEL WARM AIR ADVECTION MAKING A RETURN
12Z THURSDAY INTO FRIDAY. THIS IS A REFLECTION OF A WARM FRONTAL
PUSH THROUGH WESTERN AND CENTRAL NORTH DAKOTA THURSDAY INTO FRIDAY
MORNING...TEMPORARILY PUSHING THE MAIN BAROCLINIC ZONE INTO
SOUTHERN CANADA. HOWEVER BY FRIDAY AFTERNOON AND BEYOND...AS A
SURFACE LOW SLIDES EAST AND ALLOWS THE CLIPPER COLD FRONT TO SHIFT
THROUGH...THE BAROCLINIC ZONE WILL ADVANCE SOUTH INTO NORTH
DAKOTA. REMAINING DRY THURSDAY AND FRIDAY WITH MODERATING
TEMPERATURES. HIGHS THURSDAY WILL RANGE FROM 15F IN THE TURTLE
MOUNTAINS TO 35F IN THE SOUTHWEST. BY FRIDAY AFTERNOON...HIGHS
WILL WARM TO THE MID 20S NORTHEAST TO LOWER 40S SOUTHWEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1232 AM CST SAT FEB 28 2015
VFR TO POTENTIALLY MVFR CONDITIONS ARE EXPECTED ACROSS ALL TAF
SITES THROUGH THE TAF PERIOD. A COLD FRONT...CURRENTLY JUST EAST
OF KISN...WILL CONTINUE TO SLOWLY MOVE OFF TO THE SOUTHEAST
THROUGH THE MORNING HOURS. SOUTH WINDS WILL SHIFT OUT OF THE
NORTHWEST BEHIND THE FRONT...BEGINNING AT KISN NOW AND EVENTUALLY
MAKING IT INTO KJMS BY THIS AFTERNOON. AT THIS TIME IT APPEARS
MOST LOCATIONS WILL REMAIN VFR...HOWEVER A FEW POCKETS OF MFVR
CIGS WILL BE POSSIBLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AJ
SHORT TERM...TM
LONG TERM...KS
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS TULSA OK
1106 PM CST FRI FEB 27 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
FOR THE 6Z TAFS... VFR CONDITIONS ARE EXPECTED TO PREVAIL
OVERNIGHT AT ALL SITES. INTERMITTENT SNOW FLURRIES WILL BE
POSSIBLE AS WELL. A BRIEF PERIOD OF MVFR CONDITIONS MAY BE POSSIBLE
WITH ANY AREAS OF SNOW.
A NEW WEATHER SYSTEM WILL BRING ANOTHER ROUND OF SNOWFALL TO ALL
SITES BEGINNING DURING THE DAY SATURDAY . IFR CEILINGS AND VISIBILITY
WILL PREVAIL FOR THE REMAINDER OF THE FORECAST PERIOD WITH THIS
SYSTEM.
&&
.PREV DISCUSSION... /ISSUED 958 PM CST FRI FEB 27 2015/
DISCUSSION...
MOST OF THE SNOW HAS TAPERED OFF THIS EVENING BUT NOT BEFORE A
NARROW MESOSCALE BAND OF VERY HEAVY SNOW DUMPED 5-7 INCHES
NORTH AND NORTHWEST OF TULSA. THE SECOND ROUND OF PRECIPITATION IS
ALREADY UNDERWAY HOWEVER AS AREAS OF SNOW ARE DEVELOPING ACROSS
PARTS OF CENTRAL AND SOUTHERN OKLAHOMA AS WARM ADVECTION
INCREASES. THE HRRR INDICATES THESE SNOW AREAS WILL EXPAND SLOWLY
NORTH OVERNIGHT AND INTENSIFY AROUND SUNRISE. AS A RESULT...HAVE
EXPANDED AND EXTENDED THE WINTER WEATHER ADVISORY TO INCLUDE OUR
ENTIRE FORECAST AREA FROM NOW UNTIL MIDNIGHT SATURDAY NIGHT. THE
ADVISORY WILL LIKELY NEED TO BE EXTENDED INTO SUNDAY MORNING IN
SOME PLACES.
THE HEAVIEST SNOWFALL IS STILL EXPECTED TO FALL ACROSS NORTHEAST
OKLAHOMA AND FAR NORTHWEST ARKANSAS SATURDAY MORNING INTO EARLY
AFTERNOON. A CHANGEOVER TO SOME LIGHT SLEET AND EVENTUALLY LIGHT
FREEZING RAIN AND/OR FREEZING DRIZZLE WILL OCCUR FROM SOUTH TO
NORTH SATURDAY AFTERNOON AND EVENING. ALTHOUGH THE FREEZING
RAIN/DRIZZLE IS EXPECTED TO BE LIGHT...TRAVEL PROBLEMS ARE LIKELY
EVEN DOWN TO THE RED RIVER GIVEN THE VERY COLD ANTECEDENT
TEMPERATURES.
HAVE UPDATED POPS...SNOW AMOUNTS AND TEMPS TONIGHT INTO SATURDAY
BASED ON CURRENT AND EXPECTED CONDITIONS.
UPDATE ON THE WAY.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL MIDNIGHT SUNDAY FOR OKZ049-OKZ053-
OKZ054-OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-
OKZ062-OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-
OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.
AR...WINTER WEATHER ADVISORY UNTIL MIDNIGHT SUNDAY FOR ARZ001-ARZ002-
ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS NORMAN OK
1044 PM CST FRI FEB 27 2015
.DISCUSSION...
ANOTHER WIDESPREAD ROUND OF ACCUMULATING SNOW IS EXPECTED
AFTER 2 AM TONIGHT INTO SATURDAY.
LATEST RADARS INDICATED ONE BAND OF SNOW ASSOCIATED WITH
FRONTOGENESIS AROUND 800 MB FROM NEAR CHICKASHA TO NORMAN TO
SEMINOLE...WHICH IS FORECAST TO WEAKEN OVER THE NEXT FEW HOURS AS
IT MOVES NORTHEAST. ADDITIONAL LIGHT SNOW CONTINUES ACROSS
SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS. ACCUMULATIONS FROM
THESE FEATURES ARE EXPECTED TO BE LIGHT...GENERALLY A DUSTING TO
ONE INCH THROUGH THE NIGHT.
THE NEXT ROUND IS JUST GETTING STARTED OVER THE PANHANDLES
TO OUR WEST. THIS WILL MOVE EAST AND IMPACT THE AREA LATE TONIGHT
INTO SATURDAY. THE I-35 CORRIDOR WILL BEGIN TO BE IMPACTED IN THE
6 AM TO 8 AM RANGE. LIGHT TO MODERATE SNOW WILL BE THE MAIN
WEATHER TYPE...THOUGH SOME SLEET AND EVEN FREEZING RAIN MAY OCCUR
OVER SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS AS WARMER AIR
ALOFT MOVES IN. KEPT ACCUMULATIONS IN THE 1 TO 4 INCH RANGE WITH
THE HIGHEST ACCUMULATIONS IN NORTHERN OKLAHOMA WHERE BANDING OF
MODERATE SNOW IS HIGHEST...ALTHOUGH LATEST HRRR RUNS HAVE BEEN
SHIFTING THE HEAVIEST SNOW FARTHER SOUTH CLOSER TO I-40.
DURING THE DAY ON SATURDAY INTO SUNDAY MORNING...LIGHT ICE
ACCUMULATION FROM FREEZING DRIZZLE AND LIGHT RAIN FREEZING RAIN
WILL BE ANOTHER BIG CONCERN...AND WILL ONLY ENHANCE SLICK AND
HAZARDOUS TRAVEL. ALTHOUGH ICE AMOUNTS ARE EXPECTED TO BE LIGHT
AND GENERALLY UNDER 0.10 INCH...GLAZING MAY BE WIDESPREAD.
SLICK AND HAZARDOUS TRAVEL WILL CONTINUE THROUGH SUNDAY IN MANY
LOCATIONS. SOME IMPROVEMENT MAY OCCUR AS EARLY AS LATE SATURDAY
AFTERNOON IN FAR SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS WHERE
TEMPERATURES WILL RISE ABOVE FREEZING FIRST.
AVIATION DISCUSSION FOR THE 06Z TAFS IS BELOW.
MBS
&&
.AVIATION...
HAVE MODERATE CONFIDENCE IN THE TAFS.
THROUGH 09Z...THINK ALL LOCATIONS WILL BOUNCE BETWEEN VFR/MVFR
WITH AREAS OF -SN. IFR CONDITIONS MAY OCCUR BRIEFLY AT NEARLY
ANY SITE EXCEPT KPNC.
AFTER 09Z...ANOTHER BATCH OF HEAVIER -SN WITH IFR OR LOWER
CONDITIONS WILL MOVE INTO AND THROUGH THE AREA. KOKC WILL BE
AFFECTED MAINLY 12-21Z AND KLAW WILL BE AFFECTED 10-19Z. KSPS
MAY BE AFFECTED 10-17Z AS WELL. -PL MAY OCCUR SOUTH OF KCSM-
KSWO...BUT DID NOT MENTION DUE TO LOW CHANCES OF OCCURRENCE.
AFTER 17Z...-FZDZ WILL LIKELY DEVELOP AND SPREAD NORTHWARD...
AFFECTING MAINLY LOCATIONS SOUTH OF KCSM-KOKC. IFR OR LOWER
CONDITIONS WILL LIKELY CONTINUE DURING THIS TIME FRAME AS WELL.
WIDESPREAD LIFR CONDITIONS MAY DEVELOP AFTER 00Z.
MBS
&&
.PREV DISCUSSION... /ISSUED 543 PM CST FRI FEB 27 2015/
DISCUSSION...
AVIATION DISCUSSION FOR THE 00Z TAFS IS BELOW.
AVIATION...
HAVE MODERATE CONFIDENCE IN THE TAFS.
THROUGH 09Z...THINK ALL LOCATIONS WILL BOUNCE BETWEEN VFR/MVFR
WITH -SN FLURRIES.
AFTER 09Z...ANOTHER BATCH OF HEAVIER -SN WITH IFR OR LOWER
CONDITIONS WILL MOVE INTO AND THROUGH THE AREA. KOKC WILL BE
AFFECTED MAINLY 12-21Z AND KLAW WILL BE AFFECTED 10-19Z. KSPS
MAY BE AFFECTED 10-17Z AS WELL.
AFTER 17Z...FZDZ MAY DEVELOP AND SPREAD NORTHWARD...AFFECTING
MAINLY LOCATIONS SOUTH OF KCSM-KOKC. IFR OR LOWER CONDITIONS WILL
LIKELY CONTINUE DURING THIS TIME FRAME AS WELL.
MBS
PREV DISCUSSION... /ISSUED 256 PM CST FRI FEB 27 2015/
DISCUSSION...
THE FIRST ROUND OF THIS MULTI-PART WEATHER EVENT IS STARTING TO
WIND DOWN. THROUGH MIDNIGHT...SIGNIFICANT SNOWFALL SHOULD BE
RESTRICTED TO THE SOUTHERN THIRD OR SO OF OKLAHOMA...AND WESTERN
NORTH TEXAS. THINGS BEGIN TO TURN VERY COMPLICATED TOMORROW...AS
HIGHER TEMPERATURES START TO ADVANCE NORTH. THIS WILL...OVER THE
COURSE OF THE WEEKEND...TURN THE SNOW TO SLEET...FREEZING
RAIN...AND THEN RAIN...WITH VARIOUS COMBINATIONS THEREOF DURING
THE TRANSITION PERIOD.
THE PREVIOUSLY-ISSUED ADVISORIES APPEAR TO MAKE SENSE FOR THE
REST OF TODAY/THIS EVENING. HOWEVER...THE EVENING SHIFT WILL NEED
TO TAKE ANOTHER LOOK AT SNOW/ICE ACCUMULATION POTENTIAL
OVERNIGHT...ESPECIALLY OVER SOUTHERN OKLAHOMA AND WESTERN NORTH
TEXAS. THIS MAY REQUIRE AN EXTENSION OF OUR CURRENT ADVISORY FOR
THAT AREA.
THE MAIN BRUNT OF THE NEXT UPPER-LEVEL WAVE SHOULD AFFECT THE
NORTHERN TWO ROWS OF COUNTIES IN OKLAHOMA TOMORROW. SNOWFALL
SHOULD BE SUFFICIENT TO WARRANT THE WINTER WEATHER ADVISORY THAT
WILL BE NEW WITH THIS FORECAST UPDATE.
FREEZING RAIN WILL PROBABLY REQUIRE ADDITIONAL ADVISORIES OVER THE
WEEKEND...BUT UNCERTAINTY IN TIMING AND LOCATION PRECLUDE ISSUING
THEM NOW.
BY TUESDAY...MOST OF THE WINTER WEATHER WILL TEMPORARILY MAKE WAY
FOR A SPRINGLIKE DAY...COMPLETE WITH A CHANCE OF THUNDERSTORMS
OVER THE SOUTHEASTERN HALF OR SO OF OKLAHOMA. AT THIS
TIME...SEVERE WEATHER APPEARS TO BE UNLIKELY.
IN KEEPING WITH THE THEME OF WILD EXTREMES OF WEATHER...ANOTHER
STRONG COLD FRONT IS SCHEDULED TO ARRIVE TUESDAY AFTERNOON IN
NORTHWEST OKLAHOMA...AND LATE TUESDAY EVENING IN THE SOUTHEAST.
SOME LIGHT SNOW OR OTHER FREEZING/FROZEN PRECIPITATION WILL BE
POSSIBLE WITH THIS SYSTEM...BUT IT DOES NOT LOOK LIKE A
SIGNIFICANT EVENT. AND...BY THE END OF THE WEEK...TEMPERATURES
SHOULD REBOUND TO A FEW DEGREES BELOW THE SEASONAL AVERAGE.
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR OKZ019-
020-025-026-028>032-040>043-047-048.
WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST SATURDAY FOR
OKZ007-008-012-013-018>020-024>032-040>043-047-048.
WINTER WEATHER ADVISORY UNTIL 6 PM CST SATURDAY FOR OKZ004>006-
010-011-015>017-023-038.
WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR OKZ009-014-
021-022-034-035.
WINTER WEATHER ADVISORY UNTIL 6 PM CST SATURDAY FOR OKZ039-
044>046-050>052.
WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR OKZ033-036-
037.
TX...WINTER WEATHER ADVISORY UNTIL 6 PM CST SATURDAY FOR TXZ086-089-
090.
WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR TXZ083>085-
087-088.
&&
$$
03/17
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
507 AM MST SAT FEB 28 2015
.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...
&&
.SYNOPSIS...
LOW PRESSURE WILL SLOWLY APPROACH THE AREA THIS WEEKEND...BRINGING
MOISTURE INTO THE REGION ALONG WITH INCREASING CHANCES OF SHOWERS
SUNDAY AND MONDAY. PERIODS OF HEAVY RAIN ARE POSSIBLE AT TIMES
ESPECIALLY SUNDAY NIGHT THROUGH MONDAY AFTERNOON. COOLER
TEMPERATURES WILL ALSO ACCOMPANY THIS STORM WITH BELOW NORMAL
READINGS EXPECTED MONDAY THROUGH LATE WEEK.
&&
.DISCUSSION...
...A PROLONGED WET WINTER WEATHER EVENT IS IN STORE FOR THE DESERT
SOUTHWEST SUNDAY THROUGH LATE MONDAY...
EARLY MORNING WATER VAPOR IMAGERY REVEALS DEEPENING LOW PRESSURE
OVER OREGON WITH AN INITIAL SHORTWAVE TROUGH DEVELOPING OVER
PORTIONS OF NEVADA AND CENTRAL CALIFORNIA. TO THE SOUTH ACROSS
ARIZONA AND SOUTHERN CALIFORNIA...THE LOW HAS STARTED ADVECTING
SOMEWHAT HIGHER PWATS AND SURFACE DEWPOINTS INTO THE AREA...EVEN
STARTING TO SEE SOME SHOWERS ON RADAR ACROSS CENTRAL ARIZONA NEAR
THE MID LEVEL MOISTURE GRADIENT. HOWEVER ACROSS THE LOWER DESERTS
THIS MORNING...THERE WAS ONLY A SUBTLE INCREASE IN CLOUD COVER. 09Z
TEMPERATURES WERE QUITE A BIT WARMER THAN THIS TIME FRIDAY WITH MANY
LOCATIONS STILL IN THE LOWER 60S.
A COUPLE OF THINGS TO ADDRESS THIS MORNING WITH RESPECT TO THE
POTENTIAL FOR RAINFALL ACROSS THE AREA THIS WEEKEND INTO EARLY NEXT
WEEK. AS HAS BEEN THE CASE FOR THE LAST SEVERAL DAYS...ALL
OPERATIONAL MODELS ARE IN AGREEMENT THAT THE UPSTREAM LOW WILL SAG
SOUTHWARD...DEEPEN...AND RETROGRADE WEST OF SAN DIEGO THIS WEEKEND.
THIS STILL LOOKS ON TARGET HOWEVER THERE ARE ONCE AGAIN SIGNALS IN
THIS MORNING`S 00Z GUIDANCE TO SUGGEST PRECIP WILL BE SLOW TO ARRIVE
ACROSS THE AREA...ESPECIALLY IN THE PHOENIX METRO.
CONCEPTUALLY...MUCH OF TODAY WILL BE SPENT MOISTENING THE BOUNDARY
LAYER AS THE LOW IS STILL SEVERAL HUNDRED MILES AWAY AND HAS YET TO
TAP INTO THE DEEPER/MORE SUBSTANTIAL SUBTROPICAL MOISTURE SOURCE
SOUTH OF BAJA CALIFORNIA. IN ALL LIKELIHOOD THERE WILL BE SCATTERED
SHOWERS TO THE NORTH AND EAST OF PHOENIX WITH A FEW ISOLATED SHOWERS
ACROSS THE METRO...BUT THAT`S ABOUT IT. THIS IDEA IS SUPPORTED BY
ALL OPERATIONAL 18Z AND 00Z DETERMINISTIC MODELS AND IS ALSO WITHIN
THE WINDOW OF THE LATEST /07Z AND 08Z/ HRRR RUNS. MADE SOME DOWNWARD
ADJUSTMENTS TO THE POPS FOR TODAY ESPECIALLY ACROSS THE LOWER
DESERTS ALONG WITH SOME UPWARD ADJUSTMENTS TO TEMPERATURES. NOT
GOING TO REMOVE THE MENTION OF PRECIP ALTOGETHER FOR THE PHOENIX
AREA AS THERE COULD EASILY BE 20-30 PERCENT COVERAGE ACROSS THE
METRO. BUT FOR THE MOST PART TODAY LOOKS TO BE MORE DRY THAN WET.
BY THIS EVENING THE LOW WILL BE LOCATED WEST OF LOS ANGELES BUT
STILL TOO FAR NORTH TO TAP INTO THE AFOREMENTIONED SUBTROPICAL
MOISTURE PLUME NEAR THE BAJA SPUR. THE MODELS ARE NOW SUGGESTING THE
BEST CHANCE OF PRECIP ACROSS SOUTHEAST CALIFORNIA AND FAR SW ARIZONA
WON`T OCCUR UNTIL DURING THE DAY ON SUNDAY...ABOUT 6-12 HRS SLOWER
THAN PREVIOUSLY INDICATED. FOLLOWING THAT TREND...PRECIP ISN`T
EXPECTED TO MOVE INTO THE PHOENIX AREA UNTIL MUCH LATER AS WELL
/SUNDAY AFTERNOON OR EVENING/. THUS I MADE SOME ADJUSTMENTS TO THE
POPS/QPF AND FLOOD WATCH TIMING FOR THIS EVENT TO BETTER MATCH THE
00Z DETERMINISTIC AND PROBABILISTIC GUIDANCE. I`M NOT REMOVING POPS
ALTOGETHER FOR THE PHOENIX AREA SUNDAY BUT DRASTICALLY TRIMMING
VALUES AND HIGHLIGHTING SUNDAY EVENING THROUGH MID-DAY MONDAY AS THE
PRIME-TIME FOR SHOWERS ACROSS THE AREA. POPS DURING THIS SUNDAY
EVENING-MONDAY TIME PERIOD STILL LOOK GOOD IN THE 80-100 PERCENT
RANGE AS THIS IS WHEN THE UPPER LOW FINALLY GETS A KICK FROM ANOTHER
UPSTREAM TROUGH. ALSO NOTED A SOMEWHAT CONCERNING REDUCTION IN
ENSEMBLE QPF THIS MORNING WITH THE HIGHEST MEMBERS INDICATING AROUND
1 INCH OF PRECIP IN THE PHOENIX AREA...WITH A MEAN MORE IN THE
0.5-0.75 INCH REALM. PERHAPS THIS IS A RESULT OF THE MORE
PROGRESSIVE NATURE OF THE TROUGH VS THE SOMEWHAT NEGATIVELY TILTED
DEPICTION THE MODELS WERE INDICATING THE PAST FEW DAYS.
REGARDLESS...THERE WILL ALMOST CERTAINLY BE LOCALLY HIGHER VALUES
ESPECIALLY IN THE OROGRAPHICALLY FAVORED AREAS NORTH/EAST OF PHOENIX
WITHIN THE INHERITED FLOOD WATCH BUT I WILL MAKE SOME REDUCTIONS TO
THE TOTAL QPF FORECAST ESPECIALLY ACROSS THE SOUTHERN HALF OF THE
FORECAST AREA. WILL ADJUST THE FLOOD WATCH TO RUN FROM 5 PM SUNDAY
TO 5 PM MONDAY.
RAINFALL WILL QUICKLY MOVE THROUGH THE AREA MONDAY BUT ONE MORE
UPSTREAM TROUGH WILL DIVE SOUTHWARD TUESDAY AFTERNOON. PRECIP
CHANCES WITH THIS TROUGH WILL BE HIGHEST NORTH/EAST OF PHOENIX BUT
STILL THINK THERE COULD BE SOME SCATTERED SHOWERS ACROSS THE
DESERTS. WILL LEAVE THE FORECAST FOR TUESDAY LARGELY UNCHANGED WITH
20-30 POPS AROUND PHOENIX AND 40-50 POPS IN THE HIGHER TERRAIN.
AFTER THAT...DRY NORTHWESTERLY FLOW WILL PERSIST THROUGH MID
WEEK...FOLLOWED BY LATE WEEK RIDGING/WARMING. TEMPERATURES WILL
REACH THEIR LOWEST VALUES ON MONDAY AND WILL SLOWLY REBOUND BACK
INTO THE UPPER 70S/LOWER 80S BY LATE NEXT WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
AN APPROACHING WEATHER SYSTEM WILL BRING BREEZY SOUTHWESTERLY WINDS
DURING THE DAYTIME HOURS TODAY WITH GUSTS APPROACHING 25 KNOTS THIS
AFTERNOON. INCREASING LOW LEVEL MOISTURE WILL CAUSE PERIODIC LOW VFR
CIGS THROUGH THIS EVENING AND THEN MORE PERSISTENT BROKEN CIGS AT
5-6K FEET LATE TONIGHT. THERE IS A CHANCE OF FEW-SCT SHOWERS MAINLY
ACROSS THE NORTHERN FRINGES OF THE PHOENIX AREA THROUGHOUT THE
PERIOD WITH INCREASING CHANCES ON SUNDAY. CONFIDENCE IS TOO LOW TO
INCLUDE IN THE TAFS AT THIS TIME...EXCEPT FOR VCSH AT KSDL.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
LOW PRESSURE APPROACHING FROM THE NORTHWEST WILL KEEP GUSTY
SOUTHWESTERLY WINDS GOING THROUGH EARLY THIS EVENING WITH SOME GUSTS
APPROACHING 35 KNOTS THIS AFTERNOON. THERE IS AN OUTSIDE CHANCE OF
BLOWING DUST POSSIBLE FOR A TIME THIS AFTERNOON AT BOTH TAF SITES.
INCREASING MOISTURE LEVELS THROUGH THE COLUMN WILL ALLOW LOW VFR
CIGS TO DEVELOP THIS EVENING AND PERSIST THROUGH THE OVERNIGHT
HOURS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
COOL AND WET CONDITIONS WILL BE PRESENT ON MONDAY AND LIKELY INTO
TUESDAY WITH THE BEST CHANCES FOR WIDESPREAD RAINS ON MONDAY. THERE
WILL BE A CHANCE OF A FEW THUNDERSTORMS ON MONDAY. HUMIDITIES WILL
BE WELL ABOVE TYPICAL VALUES THROUGH TUESDAY BEFORE MINIMUM VALUES
FALL BACK INTO THE TEENS STARTING THURSDAY AFTERNOON. PERIODS OF
BREEZY SOUTHWESTERLY WINDS CAN BE EXPECTED ON MONDAY AND AGAIN ON
WEDNESDAY. HIGH TEMPERATURES ACROSS THE DESERTS WILL ONLY REACH INTO
THE 60S THROUGH WEDNESDAY. HIGH PRESSURE BRINGING WARMER AND DRIER
WEATHER SHOULD MOVE IN STARTING LATER WEDNESDAY AND SHOULD PERSIST
THROUGH THE END OF THE WEEK.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLOOD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON
AZZ021>024.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
420 AM PST Sat Feb 28 2015
.Synopsis...
A weather system is impacting California today with cooler and wetter
weather. Snow will impact travel in the mountains above 3500 feet,
and more so above 5000 feet. Showers dissipate on Sunday then a
second wave of wet weather arrives Monday.
&&
.Discussion...
Storm system continues to impact NorCal this morning. Current
radar shows that most of the shower activity is occurring across
the Western Sierra slopes south of Plumas County including
Interstate 80 and Highway 50. The center of this low pressure
storm will be over the Bay Area this afternoon and gradually
continue tracking southward. The latest HRRR run is showing that
showers along the Western Sierra slopes will continue into this
evening and that the bulk of shower activity will occur south of
Plumas County. By 3 pm, the HRRR shows that snow showers will be
south of Interstate 80 but will continue to impact Highways 50,
88, and 4.
After updating the QPF and Snow Amount forecast grids, have made a
couple of changes to the Winter Weather Advisory: 1) removed zone
68 from the Advisory which included elevations above 5000 ft for
Plumas, eastern Tehama & eastern Shasta counties 2) extended the
time of the Advisory until 10 pm to better match up with
neighboring forecast offices. As of 4 am, it looks like snow
levels are around 4500 ft and will lower down to 3500 ft as the
center of the low moves into the region. The bulk of snow
accumulation will be above 5000 ft with another 2-5 inches
possible today. Localized spots could reach Warning criteria for
snow amounts by the end of the day, but that criteria isn`t
expected to be widespread. Main message with this system is that
travel over the Sierra from Interstate 80 southward will be
hazardous at the higher elevations and motorists should expect delays.
For the rest of the forecast area, rain amounts will be hit or
miss in the valley since most of the moisture will be across
higher terrain. However, thunderstorms are possible again today
which means local spots could get brief heavy downpours as well as
small hail accumulation...both of which can also impact travel
with slick roads and lowered visibilities.
Showers will taper off late Saturday night and Sunday will bring a
brief break in wet weather. Sunday highs will be mid 60s for the
valley and 40s to 50s in the mountains. A secondary wave of wet
weather arrives Monday into early Tuesday, but moisture will be
more limited with that wave so not much additional rain/snow
expected. Snow levels should be between 4000-5000 ft. JBB
&&
.Extended Discussion (Wednesday through Saturday)
Models trending drier for Tuesday as subsidence increases under
Northerly flow aloft. Dry weather with warmer temperatures
expected through Saturday as blocking ridge off the West Coast
builds inland. High temperatures in the Central Valley expected
in the upper 60s to lower 70s with mostly 50s to 60s for the
mountains and foothills.
By Monday, even though it is out of our official forecast range,
GFS/ECMWF both show the ridge shifting into the Great Basin and a
rather deep upper level Low progressing slowly eastward between
135W to 140W west of Oregon/NorCal. JClapp
&&
.Aviation...
Upper low drops south over interior NorCal next 12 to 18 hrs with
probable areas MVFR/IFR in showers...mainly over Sierra. Potential
isolated aftn/eve t-storms with small hail today with best chances
in valley and foothills. Snow levels around 045 early this morn
lowering to near 035 later this morn or early aftn. Winds are
fairly light and variable as Low moves overhead. JClapp
&&
.STO Watches/Warnings/Advisories...
winter weather advisory until 10 pm pst this evening above 5000
feet in the west slope northern sierra nevada.
&&
$$
AREA FORECAST DISCUSSION
NWS RENO NV
318 AM PST SAT FEB 28 2015
.SYNOPSIS...
SNOW SHOWERS ASSOCIATED WITH A WINTER SYSTEM WILL CONTINUE THROUGH
THE WEEKEND. ACCUMULATING SNOW AND DIFFICULT TRAVEL ARE LIKELY IN
THE SIERRA WITH LIGHTER AMOUNTS AND MORE LOCALIZED TRAVEL ISSUES IN
WESTERN NEVADA. THIS SYSTEM WILL EXIT SUNDAY WITH A WEAKER SYSTEM
EXPECTED MONDAY AFTERNOON KEEPING TEMPERATURES BELOW NORMAL. DRY
CONDITIONS AND A WARMING TREND ARE EXPECTED LATER NEXT WEEK.
&&
.SHORT TERM...
THE CORE OF AN UPPER LEVEL LOW IS BEGINNING TO SETTLE ACROSS NORTHERN
CALIFORNIA WITH A DEFORMATION AREA DEVELOPING ACROSS THE NORTHERN
SIERRA. SNOW LEVELS ARE CURRENTLY NEAR 4500 FEET WITH SNOW BEGINNING
TO MIX IN WITH RAIN AROUND DOWNTOWN RENO. NUMEROUS CHAIN CONTROLS
EXTEND ACROSS THE TAHOE BASIN INCLUDING STRETCHES OF INTERSTATE 80
THROUGH THE SIERRA TO JUST WEST OF RENO AND HWY 395 NORTH OF RENO AS
OF 2AM. SLICK AND ICY ROADWAYS CAN BE EXPECTED THROUGH THE MORNING
WHERE SNOW WILL CONTINUE TO ACCUMULATE ON ROAD SURFACES.
MAIN IMPACTS FROM SNOWFALL WILL CONTINUE OVER THE NEXT 8-10 HOURS
ACROSS THE RENO, CARSON CITY, MINDEN REGION. THESE HAVE BEEN THE
FAVORED REGIONS FOR BANDED SNOWFALL TO DEVELOP BENEATH THE AREA OF
DEFORMATION FORCING AND INSTABILITY. LATEST RADAR AND SATELLITE
TRENDS COUPLED WITH SHORT RANGE HI-RES HRRR MODEL INDICATE MAIN BAND
OF SNOWFALL POSITIONED FROM RENO TO CARSON CITY THROUGH ABOUT 10AM
THEN SHIFTING SOUTH THROUGH DOUGLAS, ALPINE, AND NORTHERN MONO
COUNTY INTO THE EARLY AFTERNOON. ADDITIONAL SNOWFALL ACCUMULATIONS
OF 1-2 INCHES IS POSSIBLE THROUGH EARLY AFTERNOON IN FAR WESTERN
NEVADA WITH 2-4" POSSIBLE AT LAKE LEVEL. WINTER WEATHER ADVISORIES
WILL CONTINUE THROUGH LATE MORNING FOR FAR WESTERN NEVADA AND
THROUGH THE AFTERNOON ACROSS THE LAKE TAHOE BASIN.
SNOW SHOWERS WILL SHIFT SOUTH INTO MONO COUNTY THROUGH THE AFTERNOON
WITH 1-2 INCHES OF SNOWFALL POSSIBLE THROUGH THE HWY 395 CORRIDOR.
COLD TEMPERATURES ALOFT WILL ALLOW FOR INCREASED INSTABILITY WITH
DAYTIME HEATING WHICH WILL PRODUCE THE POSSIBILITY OF THUNDER
THROUGH THE AFTERNOON. LIGHT SNOW SHOWERS WILL CONTINUE THROUGH
SUNDAY AFTERNOON IN MONO COUNTY WITH 6"+ POSSIBLE ALONG THE CREST.
ANOTHER DISTURBANCE FOLLOWS SUIT ON MONDAY BUT IS SHOWING SIGNS OF
SPLITTING WITH THE SOUTHERN SHORTWAVE TRACKING OFF THE CENTRAL
CALIFORNIA COAST BY MONDAY AFTERNOON. THIS SHOULD PRESENT SOME
ADDITIONAL CHANCES FOR SNOW SHOWERS MAINLY ACROSS THE SIERRA. THIS
DOES NOT APPEAR TO BE A BIG SNOW PRODUCER BY ANY MEANS, BUT A FEW
ADDITIONAL INCHES OF SNOWFALL STILL COULD CREATE SOME TRAVEL
IMPACTS ACROSS SIERRA PASSES LATE MONDAY AFTERNOON AND EVENING.
FUENTES
.LONG TERM...TUESDAY THROUGH FRIDAY...
MODELS CONTINUE TO LOCK IN ON A FARTHER EAST (OVER EASTERN NEVADA,
IDAHO AND UTAH) SOLUTION FOR AN UPPER WAVE MOVING DOWN THE EAST SIDE
OF A PACIFIC RIDGE. THIS WILL MEAN A MOST LIKELY DRY AND COOL NORTH
FLOW ON TUESDAY FOR WESTERN NEVADA AND EASTERN CALIFORNIA. STILL, I
HAVE LEFT THE SLIGHT CHANCE OF SHOWERS OVER MONO AND MINERAL
COUNTIES TUESDAY AS A NOD TOWARDS THE FARTHER WEST SOLUTIONS SUCH AS
THE 27/12Z AND 28/00Z OPERATIONAL ECMWF. THESE SHOWERS MAY BE ABLE
TO BE PULLED ALTOGETHER SOON IF MODELS CONTINUE TO TREND EASTWARD ON
THE UPPER DISTURBANCE.
FROM WEDNESDAY THROUGH FRIDAY, GUIDANCE IS IN GOOD AGREEMENT WITH A
RIDGE REBUILDING INLAND ACROSS THE GREAT BASIN, RESULTING IN DRY
CONDITIONS AND A GRADUAL WARMING TREND. AFTERNOON TEMPERATURES WILL
RISE BACK TO NEAR AVERAGE ON THURSDAY BEFORE RISING ABOVE AVERAGE ON
FRIDAY. SNYDER
&&
.AVIATION...
UPPER LOW DIRECTLY OVER NORTHWEST/WESTERN NEVADA IS BRINGING
WIDESPREAD -SN WITH IFR (LOCALLY LIFR) CONDITIONS TO FAR WESTERN
NEVADA, WITH AREAS OF MVFR CIGS/VIS FOR THE LAKE TAHOE AREA AND OUT
TOWARDS KNFL/KLOL/KHTH (CIGS). THE SHORT RANGE HIGH RESOLUTION MODEL
(HRRR) INDICATES WIDESPREAD -SN OVER WESTERN NEVADA THIS MORNING AS
THE UPPER LOW SLOWLY DROPS SOUTH. THIS SHOULD KEEP LOWERED CIGS/VIS
AND WIDESPREAD TERRAIN OBSCURATION GOING IN -SN THIS MORNING FOR
WESTERN NEVADA, WITH AREAS OF LOW CIGS/VIS IN THE TAHOE AREA MAINLY
SOUTH OF KTRK. IMPROVEMENT IS EXPECTED THIS AFTERNOON FOR KRNO/KCXP
AS THE MAIN AREA OF SNOW SHIFTS SOUTH. PAVEMENT TEMPERATURES WILL
REMAIN NEAR FREEZING THROUGH MID MORNING FOR FAR WESTERN NEVADA AND
THE NORTHERN SIERRA SO UNTREATED SURFACES WILL SEE A LIGHT
ACCUMULATION.
FARTHER SOUTH INTO MONO AND MINERAL COUNTIES, WORSENING CIGS/VIS ARE
LIKELY TO MOVE IN LATER THIS AFTERNOON AND TONIGHT AS THE UPPER LOW
DROPS SOUTH. LIGHT SNOW ACCUMULATIONS FOR TERMINALS IN MONO COUNTY
ARE LIKELY, WITH A POSSIBLE LIGHT ACCUMULATION OUT IN MINERAL AND
SOUTHERN LYON COUNTIES BELOW 5000 FEET TONIGHT. OUT IN THE BASIN AND
RANGE (KLOL/KNFL), ACCUMULATIONS ARE UNLIKELY WITH THE MAIN ISSUE
LOWERED CIGS AND HIGHER TERRAIN OBSCURATION THIS MORNING. SNYDER
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 4 PM PST THIS AFTERNOON NVZ002.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING NVZ003.
CA...WINTER WEATHER ADVISORY UNTIL 4 PM PST THIS AFTERNOON CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION...UPDATED
NWS TAMPA BAY RUSKIN FL
530 AM EST SAT FEB 28 2015
...UPDATED TO DISCUSS INCREASED RAIN CHANCES TODAY...
.SYNOPSIS...
09Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A CURRENTLY UNAMPLIFIED
UPPER LEVEL PATTERN ACROSS THE CONUS. A GENERAL ZONAL FLOW PATTERN
IS IN PLACE OVER MUCH OF THE CONUS...ALTHOUGH ENERGY DIPPING SOUTH
ALONG THE PACIFIC COAST IS IN THE PROCESS OF EVOLVING A DEEPER
TROUGH ACROSS THE FAR WEST. THIS TROUGH WILL HAVE A POSITIVE
INFLUENCE ON OUR FORECAST AS IT EVENTUALLY HELPS TO BUILD DOWNSTREAM
RIDGING OVER THE GULF OF MEXICO AND FL PENINSULA BY THE EARLY
PORTION OF THE UPCOMING WEEK. IN THE SHORT TERM HOWEVER...OUR UPPER
LEVEL FLOW CONSISTS OF DEEP LAYER SOUTHWESTERLY FLOW OVERTOP A
SHALLOW NORTHEAST TO EASTERLY REGIME IN THE VERY LOWEST LEVELS. THE
EASTERLY FLOW IN THE LOWEST LEVELS IS THE RESULT OF THE GRADIENT
AROUND STRONG 1040+MB HIGH PRESSURE RIDGING DOWN THE ATLANTIC
SEABOARD INTO OUR REGION. THIS PATTERN WILL PERSIST FOR THE
REMAINDER OF TODAY...AND HELP DEVELOP/EXPAND A DECENT ISENTROPIC
UPGLIDE REGION NORTHWARD OVER THE FL PENINSULA.
THIS UPGLIDE REGIME IS JUST STARING TO GET ITS ACT TOGETHER WITH A
WIDESPREAD LOWER CLOUDS DECK AND A FEW SPRINKLES/LIGHT SHOWERS
SHOWING UP ON RADAR ACROSS THE REGION. THIS CLOUD DECK IS FOCUSED
BENEATH A PRONOUNCED INVERSION WHERE WINDS VEER FROM NORTHEAST TO
SOUTHEAST BETWEEN 950-900MB...AND ANOTHER INVERSION AROUND 850MB AS
SEEN ON THE 28/00Z KTBW SOUNDING PROFILE. WITH THE LOW LEVEL RIDGE
CONTINUING TO RIDGE SOUTHWARD INTO THE DAYLIGHT HOURS...THIS PATTERN
WILL ENSURE A MOSTLY CLOUDY DAY WITH SCATTERED LIGHT SHOWERS FOR
ALL.
FURTHER TO THE NORTH WE FIND NARROW BY FOCUSED ZONE OF RAIN
EXTENDING FROM SOUTH OF APALACHICOLA TO THE NATURE COAST OF
LEVY/DIXIE COUNTIES. WHILE THERE IS SOME WEAK UPGLIDE BEGINNING UP
OVER THESE AREAS AS WELL...THIS BAND OF RAIN IS MAINLY BEING FORCED
BY A APPROACH OF A SUBTLE SHORTWAVE...AND A WELL DEFINED COUPLED
UPPER LEVEL JET STRUCTURE. THE RER (RIGHT ENTRANCE REGION) OF
NORTHERN STREAM JET ENERGY EXITING UP THE EAST COAST IS COINCIDENT
WITH THE LER (LEFT EXIT REGION) OF A SOUTHERN STREAM JET STREAK
CROSSING INTO THE NORTHEAST GULF OF MEXICO. PRONOUNCED UPPER LEVEL
DIVERGENCE FIELDS ARE SHOWN BY THE GUIDANCE SUITE AND LINE UP
VERY WELL WITH THE ONGOING BAND OF RAIN. THIS BAND OF RAIN WILL BE
FLIRTING WITH NORTHERN LEVY COUNTY (CHIEFLAND) AREA INTO THE MORNING
HOURS...BEFORE THE SHORTWAVE DYNAMICS AND UPPER DIVERGENCE SHIFT
EASTWARD OUT OF OUR REGION FOR THE AFTERNOON.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
TODAY...WELCOME TO THE FINAL DAY OF METEOROLOGICAL WINTER. WHILE
ASTRONOMICAL SPRING DOES NOT ARRIVE UNTIL MARCH 20TH...
METEOROLOGICAL WINTER IS DEFINED AS DECEMBER THROUGH FEBRUARY...
WHICH MEANS TOMORROW IS THE START OF METEOROLOGICAL SPRING! IT WILL
CERTAINLY BE FEELING LIKE SPRING AROUND THESE PARTS BY THE EARLY
PART OF NEXT WEEK.
AS MENTIONED IN THE SYNOPSIS...WILL BE WATCHING THE EVOLUTION OF THE
NARROW BUT FOCUSED BAND OF RAIN FORCED BY THE COUPLED UPPER JET
STRUCTURE MOVING ACROSS APALACHEE BAY INTO THE NATURE COAST.
GENERALLY SPEAKING THE MAJORITY OF THIS RAIN SHOULD STAY JUST TO THE
NORTH OF LEVY COUNTY...BUT IT IS A VERY CLOSE CALL...AND SHOWER
ALONG THE SOUTHERN PERIPHERY OF THE BAND WILL PERIODICALLY REACH FAR
ENOUGH SOUTH TO IMPACT AREAS AROUND CHIEFLAND. HAVE LIKELY POPS FOR
NORTHERN LEVY COUNTY THIS MORNING TO ACCOUNT FOR THIS. ELSEWHERE THE
EXPANDING UPGLIDE REGIME AND CONTINUED MOISTENING OF THE LOW LEVEL
COLUMN SHOULD RESULT IN WIDELY SCT SPRINKLES/PATCHY DRIZZLE GIVING
WAY TO SCATTERED/NUMEROUS LIGHT SHOWERS ACROSS THE REGION. CERTAINLY
SOME AREA WILL END UP WITH CONDITIONS WARRANTING LIKELY RAIN
CHANCES...BUT IT IS TOUGH TO PREDICT WITHIN SUCH A BROAD UPGLIDE
REGIME JUST WHERE THE BEST QPF FIELDS WILL DEVELOP. OVERALL THE BEST
UPGLIDE FIELDS COINCIDENT WITH SPEED CONVERGENCE ALONG THE EAST
COAST SUGGEST THE HIGHEST COVERAGE OF SHOWERS WILL BE OVER OUR
INTERIOR ZONES. HOWEVER...GIVEN THE RADAR PRESENTATION AT THIS EARLY
HOURS...AND THE LATEST ECS/MAV (ECMWF AND GFS MOS) SHOWING
CATEGORICAL POPS ALL THE WAY OVER TO THE I-75 CORRIDOR...HAVE
DECIDED TO NOT FIGHT GUIDANCE AND GO WITH AT LEAST LIKELY POPS FOR
ALL AREAS LATER THIS MORNING...AND ESPECIALLY INTO THE AFTERNOON.
WILL SLOWLY RAMP UP THE POPS ACROSS THE REGION THROUGH THE FIRST
HALF OF THE DAY. THIS IS A SITUATION OF HIGH RAIN CHANCES...BUT LOW
QPF (RAINFALL AMOUNTS). THE SHOWERS SHOULD BE ON THE LIGHTER SIDE
WITH QPF GENERALLY UNDER A QUARTER OF AN INCH...AND IN MANY CASES
UNDER A TENTH OF AN INCH. THE UPGLIDE REGIME...AND DEFINED
INVERSIONS WILL KEEP OUR SKIES MOSTLY CLOUDY AND DISCOURAGE RAPID
DIURNAL TEMP RISES. THE BEST CHANCES AT ANY BREAKS OF SUN IN THE
AFTERNOON WILL BE DOWN SOUTH OF SARASOTA...AND WILL ALLOW TEMPS TO
BREAK INTO THE LOWER/MID 70S FOR THESE SOUTHERN ZONES. TEMPS FURTHER
NORTH WILL STRUGGLE MORE AS THE UPGLIDE ONLY INCREASES THROUGH THE
DAY...AND THE RIDGE CONTINUES TO SUPPLY DRIER AIR TO THE BOUNDARY
LAYER. WET BULB EFFECTS FROM THE SCT SHOWERS FALLING THROUGH THE
BOUNDARY LAYER WILL FURTHER SLOW THE TEMPERATURE RISE...AND THINK
LOCATIONS UP TOWARD TAMPA WILL STRUGGLE TO REACH 70...AND UP TOWARD
LEVY COUNTY MAY STRUGGLE TO RISE INTO THE LOWER 60S TODAY.
TONIGHT...
UPGLIDE REGIME ABOVE 5000 FEET WILL BEGIN TO PIVOT OFF TO THE
NORTHEAST WITH TIME LEAVING JUST THE VERY LOWEST LEVELS WITH ANY
LIFT. GUIDANCE IS IN AGREEMENT THAT SHOWER PRODUCTION WILL BEGIN TO
DISSIPATE QUICKLY AS THIS OCCURS AND ALSO PIVOT NORTHEAST DURING THE
EVENING HOURS. WILL TAPER RAIN CHANCES THIS EVENING AND GENERALLY
END THE SHOWERS FOR ALL AREAS AFTER MIDNIGHT. HOWEVER...THE LOWER
UPGLIDE REGIME WILL LIKELY CONTINUE TO SUPPORT LOWER STRATUS AND
WILL KEEP THE FORECAST FOR MOSTLY CLOUDY TO CLOUDS SKIES. OVERNIGHT
THE RIDGE ALSO BEGINS TO SLOWLY WEAKEN TO OUR NORTH AND ALLOW THE
GRADIENT TO RELAX OVER OUR REGION. THIS WEAKER GRADIENT IS SHOWN BY
MANY OF THE GUIDANCE MEMBERS TO ALLOW A WELL DEFINED INVERTED
SURFACE TROUGH TO DEVELOP JUST EAST OF FLORIDA OVER THE WARMER
WATERS OF THE GULF STREAM. THIS SURFACE TROUGH WILL ALSO HELP TO
FOCUS THE MAJORITY OF THE SHOWER ACTIVITY TO THE EAST AND NORTHEAST
OF OUR ZONES.
SUNDAY...
THE RIDGE LOOSES ITS GRIP ON OUR AREA ALLOWING A MUCH WEAKER
GRADIENT AND WEAKER EASTERLY FLOW TO DEVELOP. ALTHOUGH THE EASTERLY
FLOW WILL BE WEAKER...IT IS STILL SHOW TO BE ENOUGH TO MIGRATE THE
SURFACE TROUGH MENTIONED ABOVE WESTWARD OVER THE FL PENINSULA DURING
THE DAY. THIS WILL COME INTO PLAY DURING THE AFTERNOON. SUNDAY WILL
SEE THE FIRST SIGNS OF RIDGING BUILDING NORTH FROM THE CARRIBEAN
WITH OUR UPPER FLOW BECOMING MORE WESTERLY. THE LOSS OF THE
INFLUENCE FROM THE SURFACE RIDGE WILL QUICKLY DISSIPATE THE
INVERSION AND ALLOW ANY MORNING LOWER STRATUS TO BURN OFF...AND
SKIES TO BECOME PARTLY CLOUDY. THE ATMOSPHERIC TEMP POTENTIAL IS
QUITE HIGH ON SUNDAY AND THE SUNNY BREAKS SHOULD HELP BOOST TEMPS
INTO THE THE 70S NORTH AND LOWER 80S SOUTH. THE STRONG TERRESTRIAL
HEATING SHOULD ALLOW FOR WINDS TO TURN ONSHORE FOR A TIME DURING THE
AFTERNOON WITH SEA-BREEZE DEVELOPMENT. THIS IS WHERE THINGS GET
INTERESTING. WE LOOK TO ALREADY HAVE A WEAK SURFACE TROUGH IN PLACE
NEARBY TO FOCUS SOME MEAGER LOW LEVEL CONVERGENCE...NOW ADD
CONVERGENCE AS THE SEA-BREEZE INTERACTS WITH THE SURFACE TROUGH AND
WE CAN NOT RULE OUT THE POTENTIAL FOR A FEW AFTERNOON CONVECTIVE
SHOWERS...OR EVEN A THUNDERSTORM TO THE SOUTH OF I-4. IT IS
IMPORTANT TO NOTE THAT SUNDAY IS NOT GOING TO BE A WET DAY...AND
OUTDOOR PLANS SHOULD NOT BE DISCOURAGED. HOWEVER...HAVE GONE WITH A
20-30% POP SUNDAY AFTERNOON FOR THE POTENTIAL WIDELY SCT CONVECTION.
ANY RAINFALL WILL BE SHORT-LIVED...BUT HAVE TO AT LEAST MENTION THE
POTENTIAL IN THE FORECAST.
&&
.LONG TERM (MONDAY THROUGH NEXT FRIDAY)...
THROUGH WED; A BUILDING UPPER LEVEL RIDGE CENTERED OVER THE
YUCATAN...AND DOMINATING THE GULF OF MEXICO...SLOWLY SLIDES
EAST AND STRETCHES FROM THE WESTERN CARIBBEAN TO NORTHEAST OF
THE BAHAMAS. THIS IS IN RESPONSE TO A LONG WAVE TROUGH DEEPENING
OVER THE WESTERN CONUS. AT THE SURFACE HIGH PRESSURE EXTENDING
ACROSS FL FROM THE ATLANTIC WILL MOVE EAST AS HIGH PRESSURE OVER THE
NORTHERN AND CENTRAL PLAINS TRACKS EAST...ACROSS THE EASTERN SEA
BOARD TO THE OPEN ATLANTIC. THE UPPER LEVEL RIDGING WILL PROVIDE A
STABLE AND GENERALLY DRY AND WARM AIRMASS WITH TEMPERATURES ON THE
WARM SIDE OF NORMAL AND NO SIGNIFICANT RAINFALL. THE DEPARTING HIGH
PRESSURE OVER THE ATLANTIC AND THE PLAINS HIGH PRESSURE MOVING BY TO
THE NORTH WILL RESULT IN A RELAXED EASTERLY LOW LEVEL FLOW THAT
GRADUALLY BECOMES SOUTHEAST AND SOUTHERLY AND SLIGHTLY MORE ROBUST.
THE SOUTHERLY FLOW WILL ADVECT ENOUGH WARM AND HUMID AIR ACROSS THE
COOLER SHELF WATERS OF THE GULF TO POSSIBLY FORM SOME SEA FOG AROUND
MID-WEEK.
THU-FRI; BY THU THE WESTERN LONG WAVE TROUGH HAS MOVED EAST...
FROM THE UPPER GREAT LAKES TO THE SOUTHERN HIGH PLAINS...AND
CONTINUES TO THE EASTERN SEABOARD BY FRI AS IT DE-AMPLIFIES SOME.
THE CARIBBEAN-BAHAMAS RIDGE FLATTENS AND SHIFT TO THE SOUTHEAST. A
COLD FRONT ACCOMPANYING THE UPPER TROUGH MOVES INTO THE WESTERN
GULF-SOUTHEAST U.S. AREAS THU THEN THE EASTERN GULF AND ROUGHLY THE
NORTHERN HALF OF FL BY FRI. WHILE THE MODELS HAD BEEN RATHER
CONSISTENT THEY BEGIN TO DIVERGE THU AND FRI. THE GFS IS SLIGHTLY
FASTER AND MORE ROBUST WITH THE RAINFALL WHILE THE ECMWF LAGS BEHIND
AND IS DRIER. FOR NOW WILL MAINTAIN THE CURRENT FORECAST OF SLIGHT
CHANCE TO LOW END CHANCE SHOWERS. TEMPERATURES INITIALLY ABOVE
NORMAL WILL COOL TO NORMAL OR SLIGHTLY BELOW.
&&
.AVIATION...
WIDESPREAD MVFR TO IFR CONDITIONS ACROSS WEST-CENTRAL AND SOUTHWEST
FLORIDA EARLY THIS MORNING...AND CONDITIONS ARE LIKELY TO TRANSITION
TO MORE AND MORE IFR CIGS WITH TIME. THESE RESTRICTIONS ARE EXPECTED
TO LINGER INTO THE LATER MORNING HOURS...WITH CIGS SLOWLY RAISING
BACK INTO THE MVFR CATEGORY FOR ALL TERMINALS BEFORE MIDDAY. THE
AFTERNOON SHOULD FEATURE CONTINUED MVFR CIGS FOR THE TERMINALS ALONG
THE I-4 CORRIDOR...WHILE MORE SOUTHERN TERMINALS WILL HAVE A CHANCE
TO BREAK OUT INTO VFR CIGS FOR A WHILE DURING THE LATER AFTERNOON
AND EARLY EVENING HOURS. LOOK FOR SCATTERED SHOWERS THROUGH THE
DAY...HOWEVER RAINFALL IS GENERALLY EXPECTED TO BE LIGHT WITH
LIMITED VISIBILITY RESTRICTIONS. CEILING HEIGHTS SHOULD AGAIN LOWER
AFTER SUNSET THIS EVENING WITH WIDESPREAD MVFR CONDITIONS INTO THE
OVERNIGHT HOURS.
&&
.MARINE...
STRONG HIGH PRESSURE RIDGING DOWN THE EASTERN SEABOARD WILL KEEP THE
LOCAL GRADIENT TIGHT INTO THIS EVENING ACROSS THE EASTERN GULF OF
MEXICO. ADVISORY LEVEL WINDS AND SEAS OVER THE OFFSHORE WATERS EARLY
THIS MORNING WILL END BY THE AFTERNOON HOURS...BUT MAY ONCE AGAIN
BRIEFLY OCCUR THIS EVENING BEFORE THE GRADIENT BEGINS TO RELAX EARLY
SUNDAY MORNING. WINDS AND SEAS SUNDAY AND MONDAY ARE EXPECTED TO
REMAIN BELOW 15 KNOTS...WITH WINDS LOCALLY TURNING ONSHORE EACH
AFTERNOON DUE TO SEABREEZE DEVELOPMENT. HIGH PRESSURE WILL SHIFT
EASTWARD INTO THE ATLANTIC TUESDAY INTO WEDNESDAY ALLOWING WINDS
OVER THE EASTERN GULF TO SHIFT SOUTHEAST AND EVENTUALLY SOUTH WITH
TIME. AS WINDS BECOME MORE SOUTHERLY LATER TUESDAY INTO WEDNESDAY...
THE RISK LOOKS TO INCREASE FOR THE DEVELOPMENT OF SEA FOG OVER THE
NEAR SHORE WATERS AND BAYS.
&&
.FIRE WEATHER...
A CLOUDY DAY ON TAP WITH OCCASIONAL SHOWERS AND SPRINKLES
REGION-WIDE. MIXING HEIGHTS WILL BE SHALLOW KEEPING LDSI VALUES ON
THE LOW SIDE...DESPITE STEADY WINDS IN THE BOUNDARY LAYER. RELATIVE
HUMIDITY VALUES WILL REMAIN WELL ABOVE CRITICAL LEVELS. NO
SIGNIFICANT FIRE WEATHER CONCERNS CONTINUE INTO SUNDAY AND
MONDAY...WITH RELATIVE HUMIDITY VALUES WELL ABOVE CRITICAL LEVELS.
TEMPERATURES WILL BEGIN TO MODERATE ON SUNDAY AND GENERALLY BE ABOVE
AVERAGE FOR THE EARLY PORTION OF NEXT WEEK.
FOG POTENTIAL...PATCHY FOG IS EXPECTED SATURDAY NIGHT INTO EARLY
SUNDAY MORNING...WITH MORE NUMEROUS AREAS OF FOG POSSIBLE SUNDAY
NIGHT INTO MONDAY MORNING...ESPECIALLY ALONG AND TO THE NORTH OF THE
I-4 CORRIDOR. THE FOG MAY BECOME LOCALLY DENSE EARLY MONDAY MORNING
OVER THESE NORTHERN AREAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 70 62 77 64 / 50 30 30 20
FMY 78 66 83 65 / 50 20 30 10
GIF 72 63 80 64 / 60 40 30 20
SRQ 72 63 78 63 / 50 20 20 20
BKV 69 60 78 59 / 50 40 30 10
SPG 69 64 75 65 / 50 30 30 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING
FOR ENGLEWOOD TO TARPON SPRINGS OUT 20 TO 60 NM-TARPON
SPRINGS TO SUWANNEE RIVER OUT 20 TO 60 NM.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT SERVICES...RUDE
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
519 AM EST SAT FEB 28 2015
...NOR`EASTER CONDITIONS ALONG THE COAST THROUGH THIS EVENING...
...COLD AND DAMP CONDITIONS IN SOUTHEAST GA THROUGH TONIGHT...
.CURRENTLY...
EARLY MORNING SURFACE ANALYSIS DEPICTS STRONG HIGH PRESSURE (1041
MILLIBARS) CENTERED OVER THE OHIO VALLEY. A STATIONARY FRONTAL
BOUNDARY WAS LOCATED OVER THE FLORIDA STRAITS...WITH A COASTAL
TROUGH DEVELOPING OVER OUR ADJACENT ATLANTIC WATERS. ALOFT...OUR
REGION REMAINS EMBEDDED IN DEEP SOUTHWEST FLOW BETWEEN STOUT
RIDGING OVER THE SOUTHWEST ATLANTIC AND BROAD TROUGHING THAT
BLANKETS THE NORTHERN TIER OF THE NATION. A SERIES OF DISTURBANCES
ARE EMBEDDED IN THE SOUTHWEST FLOW ALOFT...AND STRENGTHENING
ISENTROPIC ASCENT HAS DEVELOPED A LENGTHY BAND OF SHOWERS OVER THE
NORTHEAST GULF OF MEXICO THAT IS MOVING RAPIDLY E-NE INTO THE
SUWANNEE VALLEY AND NORTHEAST FL. ABUNDANT CLOUDINESS AND
INCREASING BOUNDARY LAYER WINDS HAVE KEPT TEMPERATURES OVERNIGHT
IN THE 40S THROUGHOUT INLAND SOUTHEAST GA...AND TEMPS IN NORTHEAST
AND NORTH CENTRAL FL HAVE MOSTLY RISEN TO THE LOW/MID 50S.
.SHORT TERM (TODAY THROUGH MONDAY NIGHT)...
COASTAL TROUGHING WILL SHARPEN AS STRONG HIGH PRESSURE WEDGES FROM
THE APPALACHIANS INTO THE DEEP SOUTH. A TIGHTENING LOCAL PRESSURE
GRADIENT WILL INCREASE LOW-LEVEL CONVERGENCE IN COASTAL
LOCATIONS...AND DISTURBANCES ALOFT EMBEDDED WITHIN THE DEEP
SOUTHWEST FLOW WILL CONTINUE TO MIGRATE THROUGH OUR REGION. N-NE
WINDS ALONG COASTAL SOUTHEAST GA MAY APPROACH WIND ADVISORY
CRITERIA THIS AFTERNOON...BUT SUSTAINED SPEEDS MAY ONLY TOUCH 25
MPH FOR A FEW HOURS...SO WE OPTED NOT TO ISSUE A WIND ADVISORY AT
THIS TIME. WINDY CONDITIONS WILL PREVAIL NORTH OF ST. AUGUSTINE
INTO THE EVENING HOURS...WITH BREEZY CONDITIONS DEVELOPING OVER
MUCH OF OUR REGION BY AFTERNOON. HI-RES SHORT TERM GUIDANCE SUCH
AS THE HRRR KEEPS A BAND OF LIGHT TO MODERATE RAINS OVER THE
SUWANNEE VALLEY AND NORTHEAST FL THROUGH THIS AFTERNOON...WITH
COVERAGE EXPANDING INTO COASTAL SOUTHEAST GA LATER THIS MORNING.
ISENTROPIC LIFT WILL CONTINUE TO STRENGTHEN ALONG COASTAL
NORTHEAST FL...WHERE CATEGORICAL POPS WERE USED TODAY. RAINFALL
AMOUNTS SHOULD REMAIN BELOW ONE THIRD OF AN INCH ACROSS NORTHEAST
FL AND COASTAL SOUTHEAST GA...WITH HEAVIER AMOUNTS POSSIBLE ALONG
THE IMMEDIATE COAST. HIGHS WILL RANGE FROM NEAR 50 ALONG THE
SOUTHEAST GA COAST TO THE MID 60S OVER NORTH CENTRAL FL.
MEANWHILE...THE COLD AIR WEDGE WILL FILTER INTO SOUTHEAST GA AS
WEAK ISENTROPIC ASCENT DEVELOPS THIS AFTERNOON. EXPECT LIGHT RAIN
AND DRIZZLE TO DEVELOP THIS AFTERNOON...WITH HIGHS REMAINING IN
THE 40S FOR INTERIOR SOUTHEAST GA...OR MORE THAN 20 DEGREES BELOW
LATE FEB CLIMO.
THE COASTAL TROUGH WILL BEGIN LIFTING NORTHWARD THIS
EVENING...RESULTING IN A SLOW RELAXATION OF ONSHORE WINDS IN
COASTAL LOCATIONS NORTH OF ST. AUGUSTINE. LIKELY POPS WERE LEFT
IN THE FORECAST GRIDS THIS EVENING IN THE COASTAL COUNTIES...WITH
CHANCE POPS ELSEWHERE THROUGH THE NIGHT AS WEAK ISENTROPIC LIFT
PERSISTS. THIS WILL MOSTLY BE IN THE FORM OF DRIZZLE AND LIGHT
RAINFALL...WITH RAINFALL TOTALS BARELY MEASURING AFTER MIDNIGHT. A
WIDE RANGE IN LOWS ARE EXPECTED...WITH THE WEDGE KEEPING LOWS IN
THE LOWER 40S NEAR THE ALTAMAHA AND UPPER 40S ALONG THE SOUTHEAST
GA COAST. TEMPERATURES WILL REMAIN STEADY OR RISE THROUGH THE 50S
FOR MOST OF NORTHEAST AND NORTH CENTRAL FL AS LOW LEVEL WINDS VEER
TO A SOUTHEASTERLY DIRECTION.
SUNDAY...HIGH PRESSURE ALONG THE MID ATLANTIC COAST BEGINS TO
WEAKEN AS THE COASTAL TROUGH LIFTS NORTHEAST RESULTING IN DECREASING
WINDS AND RAIN CHANCES BY THE THE AFTERNOON. HAVE CHANCE POPS IN
THE MORNING FOLLOWED BY SOME DECREASE IN CLOUDS AND LOWER POPS IN THE
AFTERNOON. HOWEVER...THE WEDGE IS LIKELY HOLD IN ACROSS SE GA
PRODUCING A CONTINUATION OF MOSTLY CLOUDY AND COOL CONDITIONS
THERE. A WIDE RANGE IN AFTERNOON TEMPS RANGING FROM NEAR 60 ACROSS
THE FAR NORTH... WHERE THERE WILL STILL BE EVIDENCE OF A WEDGE
HOLDING ON THERE... TO THE UPPER 70S ACROSS THE FAR SOUTH WHERE
VEERING WINDS AND FEW PEAKS OF SUN WILL HELP WARM TEMPS THERE.
SUNDAY NIGHT...WITH LIGHT WINDS...RETURN OF LOW LEVEL
MOISTURE...AND DRIER MID LEVEL AIR...CONDITIONS APPEAR FAVORABLE
FOR AREAS OF LATE NIGHT FOG TO FORM. THE FOG MAY BE LOCALLY DENSE
IN A FEW SPOTS. GUIDANCE APPEARED TOO COOL AND WENT WITH MIN TEMPS
RANGING FROM THE UPPER 40S ACROSS THE FAR NORTH TO NEAR 60 FAR
SOUTH.
MONDAY......A WEAK AREA OF HIGH PRESSURE WILL BE SITUATED ACROSS
THE REGION AND WITH WEAK DYNAMICS EXPECTING WARMER AND MORE STABLE
CONDITIONS AREA WIDE. AFTER MORNING FOG...SKIES BECOMING PARTLY
CLOUDY WITH AFTER TEMPS REACHING WELL INTO THE 70S ACROSS THE
INLAND AREAS OF THE FAR SOUTH...LOWER TO MID 70S ACROSS THE REST
OF THE INLAND AREAS...TO MID/UPPER 60S ALONG THE COAST.
MONDAY NIGHT...A FRONT WILL STALL OUT NORTH OF THE AREA BUT MAY
PRODUCE OF FEW SHOWERS ACROSS SE GA. OTHERWISE ANOTHER PARTLY
CLOUDY NIGHT WITH AREAS OF LATE NIGHT FOG. MIN TEMPS ONLY
FALLING INTO THE UPPER 50S TO NEAR 60 DEGREES.
.LONG TERM (TUESDAY THROUGH FRIDAY)...
A MID/UPPER RIDGE BUILDS IN ACROSS THE AREA FROM THE CARBON WHILE
A STRONG SURFACE HIGH QUICKLY MOVES OFFSHORE THE U.S. EAST COAST.
THIS RESULTS IN A STEADY WARM UP EACH DAY AS LOW LEVEL WINDS
CONTINUE TO VEER TO THE SOUTH...WITH TEMPS WELL ABOVE NORMAL BY
MID WEEK WHEN AFTERNOON TEMPS EXPECTED TO CLIMB INTO THE LOWER 80S
AWAY FROM THE COAST. THE NEXT COLD FRONT WILL BRING A CHANCE OF
SHOWERS TO THE AREA THURSDAY/THURSDAY NIGHT WITH LINGERING RAIN
CHANCES ACROSS THE SE ZONES FRIDAY AS THE FRONT IS EXPECTED TO
SLOW DOWN. COOLER CONDITIONS EXPECTED BEHIND THE FRONT WITH BELOW
NORMAL TEMPS BY THE END OF THE PERIOD.
&&
.AVIATION...
MVFR CIGS WILL PREVAIL AT THE NORTHEAST FLORIDA TERMINALS THROUGH
AROUND 15Z/16Z. VFR CIGS AROUND 3500 FT ARE EXPECTED AT SSI
THROUGH AROUND 12Z...WITH MVFR CIGS THEN THROUGH AROUND 18Z.
STRONG NORTHEAST WINDS PREVAIL JUST ABOVE THE SURFACE...WITH
SPEEDS AT 1500 FT IN THE 35-40 KNOT RANGE. THESE STRONG WINDS
JUST OFF THE SURFACE WILL PREVAIL THROUGH AROUND 15Z AT THE
REGIONAL TERMINALS...CREATING LOW LEVEL WIND SHEAR. NORTH TO
NORTHEAST SURFACE WINDS SUSTAINED AT 10-15 KNOTS ARE EXPECTED AT
THE NORTHEAST FLORIDA TERMINALS...WITH FREQUENT GUSTS OF 20-25
KNOTS DEVELOPING AFTER SUNRISE. SUSTAINED WINDS AT SSI NEAR 15
KNOTS EARLY THIS MORNING WILL INCREASE TO NEAR 20 KNOTS AFTER
SUNRISE. MOSTLY LIGHT RAINFALL WILL OVERSPREAD THE TERMINALS AS
THE MORNING PROGRESSES. IFR CIGS WILL LIKELY DEVELOP IN THE 15Z-
18Z TIME FRAME...WITH SOME PERIODS OF HEAVIER RAINFALL POSSIBLE
THROUGH 00Z. IFR CIGS WILL LIKELY PERSIST THROUGH THE EVENING
HOURS AT THE REGIONAL TERMINALS.
&&
.MARINE...
SMALL CRAFT ADVISORY CONDITIONS WILL CONTINUE THROUGH AT LEAST
SUNDAY MORNING OVER THE NEAR SHORE WATERS...AND THROUGH AT LEAST
SUNDAY EVENING OFFSHORE. A COASTAL TROUGH WILL SHARPEN LATER THIS
MORNING AND AFTERNOON...CREATING OCCASIONAL GALE FORCE
GUSTS...ESPECIALLY OVER THE ADJACENT SOUTHEAST GEORGIA COASTAL
WATERS. WINDS SOUTH OF ST. AUGUSTINE MAY SUBSIDE BELOW SCA LATER
TODAY...BUT CONFIDENCE REMAINS LOW AND ELEVATED SEAS WILL REMAIN
IN THE 6-7 FT RANGE. ELSEWHERE...SEAS OVER THE NEAR SHORE GEORGIA
WATERS MAY APPROACH 8 FT...WITH OCCASIONAL SEAS UP TO 10 FEET
POSSIBLE. OFFSHORE SEAS WILL LIKELY PEAK IN THE 8-11 FT RANGE
TODAY...ONLY GRADUALLY SUBSIDING THROUGH SUNDAY. WINDS WILL
DECREASE FROM SOUTH TO NORTH TONIGHT AS THE COASTAL TROUGH LIFTS
NORTHWARD...BUT SEAS WILL REMAIN AT SCA LEVELS NEAR SHORE THROUGH
SUNDAY MORNING. SEAS OFFSHORE WILL REMAIN AT SCA LEVELS THROUGH
SUNDAY NIGHT. WINDS AND SEAS WILL CONTINUE TO SUBSIDE EARLY NEXT
WEEK...WITH SOUTHERLY WINDS AND SEAS INCREASING WELL IN ADVANCE
OF A FRONTAL BOUNDARY TOWARDS MIDWEEK.
RIP CURRENTS: HIGH RISK EXPECTED TODAY...WITH BREAKERS EXPECTED IN
THE 4 TO 6 FOOT RANGE AT THE BEACHES. MODERATE TO HIGH RISK
EXPECTED ON SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 47 42 60 48 / 50 50 30 20
SSI 50 47 59 51 / 60 60 30 20
JAX 54 51 67 51 / 80 60 30 10
SGJ 60 57 67 55 / 80 70 30 10
GNV 59 54 73 56 / 60 40 30 10
OCF 66 58 77 58 / 60 40 30 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH LATE TONIGHT FOR COASTAL DUVAL-
COASTAL NASSAU-FLAGLER-ST. JOHNS.
GA...HIGH RIP CURRENT RISK THROUGH LATE TONIGHT FOR COASTAL CAMDEN-
COASTAL GLYNN.
AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR WATERS FROM
ALTAMAHA SOUND GA TO FERNANDINA BEACH FL FROM 20 TO 60 NM-
WATERS FROM FERNANDINA BEACH TO ST. AUGUSTINE FL FROM 20 TO
60 NM-WATERS FROM ST. AUGUSTINE TO FLAGLER BEACH FL FROM 20
TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 10 AM EST SUNDAY FOR COASTAL WATERS
FROM ALTAMAHA SOUND TO FERNANDINA BEACH FL OUT 20 NM-
COASTAL WATERS FROM FERNANDINA BEACH TO ST. AUGUSTINE FL
OUT 20 NM-COASTAL WATERS FROM ST. AUGUSTINE TO FLAGLER
BEACH FL OUT 20 NM.
&&
$$
NELSON/PETERSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
628 AM EST SAT FEB 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM EST SAT FEB 28 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A MORE SPLIT FLOW
OVER NAMERICA WITH UPR MI ON THE SRN FLANK OF A WNW FLOW ON THE SW
FLANK OF ARCTIC BRANCH CLOSED LO DRIFTING OFF THE NEWFOUNDLAND
COAST. SHRTWV RDG APRCHG THRU MN/VERY DRY AIR SHOWN ON LOCAL 00Z
RAOBS /00Z PWATS WERE ARND 0.07 INCH OR 30-35 PCT OF NORMAL/ ARE
RESULTING IN MOCLR SKIES EARLY THIS MRNG. DESPITE DRYNESS OF THIS
AIRMASS AND CHILL WITH 00Z H85 TEMPS IN THE -16 TO -17C RANGE...
STEADY WSW FLOW UNDER THE RATHER TIGHT PRES GRADIENT TO THE N OF HI
CENTER IN THE OH RIVER VALLEY HAS RESTRICTED THE DROP IN TEMP OVER
MUCH OF THE CWA...ESPECIALLY AT THE MORE EXPOSED LOCATIONS NEAR THE
LAKES...WHERE CURRENT TEMPS RANGE FM ZERO TO 10 ABOVE. BUT SOME OF
THE SHELTERED INTERIOR LOCATIONS HAVE SEEN THE MERCURY FALL TO AS LO
AS -15F TO -20F. LOOKING UPSTREAM...HI CLDS ARE STREAMING INTO MN IN
ADVANCE OF A SHRTWV MOVING E INTO NDAKOTA. BUT SINCE THE AIRMASS IN
THE NRN PLAINS IS ALSO QUITE DRY /AREA PWATS ARE UNDER 0.10 INCH AND
THE 00Z H85 AND H7 DEWPT DEPRESSIONS AT BISMARCK WERE 19C AND 30C
RESPECTIVELY/...THERE IS AN ABSENCE OF PCPN ACCOMPANYING THIS
DISTURBANCE.
MAIN FCST CONCERNS IN THE SHORT TERM WL FOCUS ON MAX TEMPS TODAY AND
IMPACT TNGT OF SHRTWV NOW MOVING THRU THE NRN PLAINS.
TODAY...SHRTWV RDG AXIS NOW IN MN IS PROGGED TO PASS THRU THE CWA
THIS AFTN. ACCOMPANYING AREA OF H85-5 RH UNDER 20 PCT WL RESULT IN
SUNSHINE FILTERED AT TIMES BY SOME HI CLDS STREAMING INTO THE AREA
IN ADVANCE OF SHRTWV THAT IS FCST TO REACH NW MN BY 00Z SUN. AS H85
TEMPS REBOUND TO ARND -14C IN THE SW FLOW ARND SFC HI PRES SHIFTING
TOWARD THE MID ATLANTIC STATES...EXPECT MAX TEMPS TO TOP OUT A
COUPLE OF DEGREES HIER THAN OBSVD YDAY...PERHAPS UP TO 25 IN THE
DOWNSLOPE AREAS NEAR LK SUP BTWN MARQUETTE AND BARAGA. THE LOWEST
TEMPS IN THE TEENS ARE LIKELY DOWNWIND OF THE ICE COVERED NRN BAY OF
GREEN BAY/LK MI.
TNGT...SHRTWV OVER NW MN IS PROGGED TO SHIFT E ACROSS NRN LK SUP AND
INTO ONTARIO JUST E OF THE LK BY 12Z ON SUN. SOME DPVA/MODEST DEEP
LYR QVECTOR CNVGC IS FCST TO INFLUENCE UPR MI AHEAD OF THE SHRTWV.
BUT MODEST MSTR INFLOW/ISENTROPIC ASCENT INTO ANTECEDENT BONE DRY
AIRMASS WL GREATLY RESTRICT POPS. IN FACT...MOST OF THE MODELS
INDICATE A MAINLY DRY OVERNGT AND GENERATE ONLY PATCHY LIGHT PCPN.
SEEMS THE BEST CHC FOR PCPN WL BE OVER LK SUP AND PERHAPS DOWNWIND
OF LK MI FM MANISTIQUE TO NEWBERRY. WL RETAIN MENTION OF SCHC
POPS...MAINLY OVERNGT. LO TEMPS TNGT COULD BE TRICKY WITH LINGERING
DRY AIR IN PLACE BEFORE THICKER CLDS ARRIVE. TENDED TO GO HIER WITH
MIN TEMPS IN THE DOWNSLOPE AREAS NEAR LK SUP IN PREVAILING SSW FLOW.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 351 AM EST SAT FEB 28 2015
MAIN ISSUE THIS FORECAST PERIOD WILL BE WIDESPREAD LIGHT TO MODERATE
SNOWFALL POTENTIAL TUESDAY INTO TUESDAY EVENING WITH CONTINUED
MODERATING TEMPERATURES.
SUNDAY THROUGH MONDAY...A SURFACE TROUGH/WEAK COLD FRONT WILL
CONTINUE TO SHIFT EASTWARD AND PASS THROUGH THE CENTRAL AND EASTERN
PORTIONS OF THE UPPER PENINSULA THROUGH THE DAY SUNDAY. MOISTURE
WILL BE SHALLOW AND FAIRLY LIMITED ALONG THE FRONT WITH CONTINUED
WEAK FORCING. THIS WILL TOUCH OFF VERY LIGHT SNOW THROUGH THE DAY
SUNDAY. BEHIND THE FRONT...AN UPPER LEVEL 500MB TROUGH IS POISED TO
SWING ACROSS THE U.P. SUNDAY NIGHT. AS THIS HAPPENS...ENOUGH
MOISTURE WILL REMAIN IN PLACE WITH MINIMAL ADDITIONAL MOISTURE ADDED
FROM THE VERY ICE COVERED LAKE SUPERIOR TO ALLOW A CHANCE OF LAKE
EFFECT SNOW SHOWERS TO DEVELOP FOR WEST TO NORTHWEST WIND FAVORED
LOCATIONS. 850MB TEMPERATURES WILL DROP TO AROUND -15C TO -20C
ALLOWING FOR SUFFICIENT DELTA T VALUES FOR LAKE EFFECT WITH THE
TROUGH AXIS SLIDING ACROSS...BUT LAKE EFFECT INTENSITY/COVERAGE WILL
BE LIMITED TO AREAS THAT BREAKS IN THE ICE COVER OCCUR. THIS IS
ESPECIALLY TRUE NOW THAT THE ICE EXTENT ON LAKE SUPERIOR IS AT 95.55
COVERED...WHICH IS THE MAX FOR THE SEASON TO THIS POINT. ANY LAKE
EFFECT THAT IS ABLE TO DEVELOP SUNDAY NIGHT WILL BE SHORT LIVED AS
MUCH DRIER AIR AND HIGH PRESSURE AT THE SURFACE AND RIDGING ALOFT
PUSH INTO THE UPPER GREAT LAKES REGION DURING THE DAY MONDAY. THIS
WILL ALL MOST AREAS TO SEE MAINLY SUNNY SKIES DURING THE DAY MONDAY
WITH HIGHS IN THE 20S FOR MOST AREAS. THIS IS STILL BE AROUND 5 TO
10 DEGREES BELOW NORMAL...BUT IT WILL DEFINITELY BE WARMER THAN THE
LAST SEVERAL WEEKS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE SURFACE HIGH PRESSURE
SYSTEM WILL BE SHORT LIVED AND WILL SHIFT TO THE LOWER GREAT LAKES
THROUGH MONDAY EVENING...THEN TO THE EASTERN SEABOARD LATE MONDAY
NIGHT. THIS WILL ALLOW A MORE MOIST...SLIGHTLY WARMER...SOUTHERLY
FLOW TO DEVELOP ON THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A
SURFACE LOW PRESSURE SYSTEM IS PROGGED TO DEVELOP ALONG A SHORTWAVE
OVER THE FOUR CORNERS REGION OF THE CONUS. ANOTHER STRONGER WAVE OF
ENERGY IS PROGGED TO PUSH ACROSS CENTRAL CANADA AND WORK TOWARD THE
JAMES BAY AREA. MODEL DIFFERENCES CONTINUE WITH THE PHASING OF THE
TWO SYSTEMS. THE 18Z/27 00Z/28 GFS CONTINUES TO BE MORE PROGRESSIVE
WITH BOTH SYSTEMS AND THE PHASING OF THE SYSTEMS.
ADDITIONALLY...THE GFS INTENSIFIES THE SOUTHERN SYSTEM MORE
AGGRESSIVELY THAN THE LAST TWO RUNS OF THE EC. EVEN THOUGH IT IS
MORE PROGRESSIVE OVERALL...THE LATEST RUNS OF THE GFS ARE SLOWER
WITH BRINGING PRECIP INTO THE AREA THAN IT HAS BEEN OVER THE
PREVIOUS DAYS RUNS...MORE IN LINE WITH THE EC. THE EC 12/27 00Z/28
CONTINUES TO BE MUCH SLOWER WITH THE PHASING...KEEPING THE
PRECIPITATION OUT OF THE AREA UNTIL VERY LATE MONDAY NIGHT INTO
TUESDAY MORNING. THE OVERALL IMPACT...AS FAR AS SNOWFALL
AMOUNTS...WILL LARGELY DEPEND ON HOW AND WHEN THESE SYSTEM MERGE.
EITHER WAY...IT DOES LOOK LIKE MOST OF THE U.P. WILL SEE WIDESPREAD
SNOWFALL THROUGH THE DAY TUESDAY INTO TUESDAY EVENING...WITH THE
HEAVIER SNOWFALL TOTALS EXPECTED ACROSS SOUTH CENTRAL AND THE EAST
HALF OF THE U.P. MODELS AGREE WITH QPF BEING PAINTED OUT ACROSS
THESE AREAS TO THE POINT THAT LIKELY POPS ARE IN ORDER ESPECIALLY
TUESDAY AFTERNOON INTO TUESDAY EVENING
...AGAIN THE AMOUNTS ARE THE MAIN QUESTION AT THIS POINT WITH THE
GFS PLACING AROUND A HALF INCH QPF ACROSS THE AREA AND THE EC
PAINTING AROUND A QUARTER INCH. THIS WOULD GIVE SNOWFALL TOTALS OF
AROUND 1 TO 3 INCHES OVER THE WEST HALF WITH AROUND 2 TO 5 INCHES
OVER THE EAST HALF...AGAIN THESE ARE PRELIMINARY ESTIMATES AND WILL
BE ADJUSTED AS MODELS BEGIN TO COME INTO BETTER AGREEMENT WITH
BETTER SAMPLING OVER TIME. THE FORTUNATE ASPECT OF THIS SYSTEM IS
THAT IT IS FAIRLY QUICK MOVING...WHICH SHOULD HELP TO KEEP SNOWFALL
TOTALS IN CHECK...BUT IT COULD BE SOMEWHAT OF A HASSLE AS THE
HEAVIER SNOW WOULD FALL DURING THE TUESDAY AFTERNOON/EVENING COMMUTE.
WEDNESDAY THROUGH THE REMAINING EXTENDED...BOTH THE EC AND GFS AGREE
ON AN UPPER LEVEL TROUGH AXIS ALONG WITH CONTINUED MOISTURE ACROSS
THE AREA DURING THIS TIME PERIOD. THE COLDER TEMPERATURES ALOFT
ALONG WITH ANY ADDITIONAL MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR
LAKE EFFECT SNOW CHANCES ACROSS PORTIONS OF THE U.P...ESPECIALLY
THROUGH THURSDAY. AGAIN...THE EXACT LOCATION ALONG WITH INTENSITY
WILL BE LARGELY TIED TO ANY BREAKS IN THE ICE COVER ON LAKE
SUPERIOR. THE FAVORED LOCATIONS BASED SOLELY ON WIND WOULD BE FOR
THE WEST TO WEST NORTHWEST WIND FAVORED SNOW BELTS WITH A SURFACE
HIGH PRESSURE SYSTEM PASSING TO THE SOUTH OF THE REGION.
GENERALLY...ANY LAKE EFFECT SNOW SHOULD REMAIN FAIRLY LIGHT...BUT
THIS WILL DEPEND ON ANY BREAKS IN THE ICE ON LAKE SUPERIOR. THURSDAY
NIGHT...THE SURFACE HIGH WILL SHIFT TO THE EAST OF THE AREA AS A
SURFACE TROUGH APPROACHES THE U.P. FROM THE WEST. THIS WILL
EFFECTIVELY TURN WINDS SOUTH TO SOUTHWESTERLY...ENDING ANY LAKE
EFFECT SNOW CHANCES ACROSS THE U.P.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 628 AM EST SAT FEB 28 2015
A DRY SW FLOW ARND HI PRES SHIFTING TOWARD THE MID ATLANTIC STATES
WL BRING VFR CONDITIONS TO THE TAF SITES THRU THIS FCST PERIOD. SOME
THICKER CLDS WL ARRIVE TNGT IN ADVANCE OF AN APRCHG LO PRES TROF...
BUT THE LLVLS SHOULD REMAIN DRY ENUF TO MAINTAIN VFR CIGS EVEN IF
THERE IS SOME VERY LIGHT SN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 AM EST SAT FEB 28 2015
NO GALES EXPECTED INTO NEXT WEEK...WITH WINDS NO HIGHER THAN 20 TO
25 KTS. LAKE SUPERIOR REMAINS MOSTLY ICE COVERED AND THOUGH SHIFTING
WINDS WITH A SERIES OF TROUGH PASSAGES MAY CAUSE HOLES TO OPEN IN
THE ICE FROM TIME TO TIME...A CONTINUED DOMINANCE OF ARCTIC AIR WILL
MAINTAIN AN OVERALL EXTENSIVE ICE COVER.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
701 AM CST SAT FEB 28 2015
.UPDATE...
ISSUED AT 658 AM CST SAT FEB 28 2015
NO UPDATE NECESSARY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 315 AM CST SAT FEB 28 2015
FORECAST CHALLENGES CONCERN TEMPERATURES AND LOW END SNOW CHANCES.
MAIN MODEL DIFFERENCES WILL BE -SN POTENTIAL WITH WEAK WAVE
PASSAGES AND WILL USE A BLEND.
SEVERAL WEAK WAVES WILL ROTATE THROUGH BASE OF NORTHERN STREAM MID
LEVEL TROUGH THIS WEEKEND. FIRST OF THESE FEATURES AND ASSOCIATED
SURFACE TROUGH MOVING INTO WESTERN ND WILL PROPAGATE EAST ACROSS
FA LATER TODAY AND TONIGHT. ECMWF CONTINUES TO BE WEAKEST WITH -SN
POTENTIAL. AT THIS POINT IT LOOKS TO BE THE ODD MODEL OUT AS
GFS/GEM/NAM ALL SHOWING BETTER SNOW POTENTIAL ALBEIT LIGHT MAINLY
THIS EVENING. RUC ALSO DEVELOPING -SN FROM VALLEY EASTWARD LATE
THIS AFTERNOON INTO THE EVENING. WITH RUCS SPOTTY NATURE OF
POSSIBLE -SN HESITANT TO RAISE POPS TOO FAR AND KEPT WITHIN CHANCE
RANGE. LOW LEVEL WARM ADVECTION WILL CONTINUE AHEAD OF TROUGH AND
WILL BE STARTING OUT ABOUT 10 DEGREES WARMER THAN YESTERDAY.
SATELLITE IMAGERY/SFC OBS INDICATING BKN SC DECK ACROSS CENTRAL-
WESTERN ND WHICH SHOULD MOVE IN TODAY WHICH MAY HAVE AN IMPACT ON
DEGREE OF WARMING. FOR THIS WAS CONSERVATIVE ON MAXIMUM
TEMPERATURES. ANY -SN THIS EVENING OVER NW MN SHOULD EXIT FA TO
THE EAST AFT MIDNIGHT. OVERALL LOOKING A HALF INCH OR SO OF
POTENTIAL ACCUMULATION. CLOUDS WILL ALSO HAVE A BEARING ON MINIMUM
TEMPERATURES TONIGHT.
A WEAKER WAVE WILL AFFECT FA ON SUNDAY. SURFACE FEATURES ALSO
WEAKER SO LIKELY LOOKING AT MAINLY FLURRIES BUT DID INTRODUCE SOME
LOW POPS OVER NW MN LATE IN THE AFTERNOON. FOLLOWED PERSISTENCE
WITH TEMPERATURES AS CLOUDS AND HOW COLD WE START OUT IN THE MORNING
WILL IMPACT MAX TEMPERATURES.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 AM CST SAT FEB 28 2015
HIGH PRESSURE WILL SHIFT ACROSS CENTRAL PLAINS SUNDAY NIGHT. WITH
HIGH CENTER TO OUR SOUTH W-SW SURFACE FLOW AND WARM ADVECTION WILL
LIMIT TEMPERATURE DROP AND SHOULD SEE MINS A FEW DEGREES EITHER
SIDE OF ZERO.
BRISK SOUTHERLY FLOW AND CONTINUED WARM ADVECTION MONDAY SHOULD
ALLOW TEMPERATURES TO FINALLY APPROACH SEASONAL AVERAGES.
MAINTAINED LOW POPS MONDAY NIGHT WITH APPROACH OF NEXT WAVE AND
COLD FRONT ALTHOUGH MODELS NOT IN VERY GOOD AGREEMENT. BASED ON
TIMING OF COLD FRONT BOUNDARY LOOKS TO BE THROUGH ALL BUT THE FAR
SE BY MORNING. THIS COULD SET UP RESPECTABLE TEMPERATURE CONTRAST
ACROSS THE FA WITH COLDEST MINIMUMS ACROSS THE NW DEEPER IN THE
COLDER AIR.
A BREEZY TO WINDY EXTENDED PERIOD LOOKS TO BE SHAPING UP AS ARCTIC
BOUNDARY PUSHES THROUGH THE FORECAST AREA EARLY TUESDAY SWINGING
WINDS FROM SW TO NNW. CAA BEHIND BOUNDARY WILL MAKE WEDNESDAY THE
COLDEST OF THE BUNCH WITH AREA WIDE HIGHS ONLY IN THE POSITIVE
SINGLE INTEGERS. GFS/ECMWF ARE CLOSE WITH 850 MB TEMPS PEGGING A
CORE OF -20 TO NEAR -30C INTO AND THROUGH THE NORTHERN VALLEY. ASIDE
FROM A PERIOD OF LIGHT SNOW/SNOW SHOWERS FOR WC MN TUE AFTN THE
ENTIRETY OF THE EXTENDED IS ESSENTIALLY POP FREE. UPPER FLOW BECOMES
MORE ZONAL THUR INTO FRI AND AS SURFACE HIGH DRIFTS SOUTH AND
SOUTHEAST EXPECT THERMAL RECOVERY TO NEAR AVERAGE VALUES BY
FRI...MAXES FROM THE UPPER 20S TO LOW 30S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 658 AM CST SAT FEB 28 2015
OFF AND ON VFR CIGS EXPECTED ACROSS THE REGION TODAY AHEAD OF A
WEAK FRONTAL BOUNDARY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...VOELKER
LONG TERM...WJB/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS MEDFORD OR
306 AM PST SAT FEB 28 2015
.DISCUSSION...CURRENT WATER VAPOR IMAGE SHOWS THE UPPER TROUGH
MOVING SOUTH AND IS OVER THE FORECAST AREA. PLENTY OF SHOWERS ARE
AROUND AND SOME OF THOSE ARE IN THE LOWER LEVELS THAT THE RADAR
CANNOT PICK UP ON, ESPECIALLY EAST OF THE CASCADES BECAUSE IT`S
OVER SHOOTING THE LOW LEVEL MOISTURE. A LOOK AT THE CAMERAS AT
SISKIYOU SUMMIT SUGGEST ROADS THERE ARE SLICK WITH AN INCH OR LESS
OF SNOW. IT`S ALSO SNOWING ALONG DEAD INDIAN MEMORIAL SUMMIT WITH
ROADS SNOW COVERED THERE. SNOW HAS STOPPED FOR THE MOMENT AT
DIAMOND LAKE AND LAKE OF THE WOODS. COULD NOT RULE OUT ADDITIONAL
SNOW SHOWERS THIS MORNING, BUT WITH LITTLE OR NO ADDITIONAL
ACCUMULATION.
TEMPERATURES IN NORTHEAST OREGON...SOUTHEAST WASHINGTON AND
WESTERN IDAHO REMAIN RELATIVELY MILD AND HAVE NOT DROPPED MUCH
DURING THE OVERNIGHT HOURS. TEMPERATURES EAST OF THE CASCADES HAVE
BEEN SITTING AROUND FREEZING. THIS SHOULD REMAIN THE CASE INTO THE
MORNING HOURS AND WITH DAYTIME WARMING WHICH SHOULD LIMIT THE
AMOUNT OF ACCUMULATING SNOW. THE NAM CONTINUES TO SHOW UPSLOPE
FLOW EAST OF THE CASCADES AS HIGH PRESSURE BUILDS IN FROM THE
NORTH. ALSO THE HRRR RADAR REFLECTIVITY PICKS UP ON THIS FEATURE
WELL. THEREFORE EXPECT SNOW TO DEVELOP IN EASTERN KLAMATH AND LAKE
COUNTIES THIS MORNING, THEN DECREASE AND MOVING SOUTH IN THE
AFTERNOON. STILL COULD NOT RULE OUT 1-3 INCHES FOR THESE LOCATIONS
THROUGH THE MORNING HOURS.
AS THE UPPER TROUGH MOVES SOUTH THIS AFTERNOON, A DRY NORTHEAST
FLOW WILL SET UP AND WE`LL SEE PRECIPITATION QUICKLY ENDING FROM
NORTHWEST TO SOUTHEAST. PRECIPITATION COULD LINGER INTO THE
AFTERNOON FOR THE NORTH FACING SLOPES OF THE SISKIYOUS DUE TO
NORTHERLY UPSLOPE FLOW, BUT IT WILL BE LIGHT AND WITH WARMING
ROADS IT SHOULD NOT ACCUMULATE.
THE UPPER TROUGH/LOW WILL CONTINUE TO MOVE SOUTH TONIGHT AND RIDGE
WILL NUDGE INTO WESTERN OREGON. DRY WEATHER IS EXPECTED TONIGHT
WITH MOSTLY CLEAR SKIES AND COLDER TEMPERATURES. SUNDAY REMAINS
DRY WITH CLEAR SKIES AND MILDER TEMPERATURES IN THE AFTERNOON.
MODELS SHOW ANOTHER SHORTWAVE MOVING SOUTH ALONG THE NORTHWEST
COAST SUNDAY NIGHT INTO MONDAY. THE MODELS ARE IN SIMILAR AGREEMENT
SHOWING JUST ENOUGH OVER WATER TRAJECTORY FOR PRECIPITATION TO
SPREAD INTO WESTERN OREGON. THIS SHORTWAVE WILL BE A QUICK MOVER,
SO NOT EXPECTING A LOT OF QPF FROM THIS AND MOST OF IT WILL BE
ALONG AND WEST OF THE CASCADES.
DRY WEATHER RETURNS TUESDAY AND COULD VERY WELL LAST INTO NEXT
WEEKEND. THE GFS AND EC SHOW SIMILAR RESULTS WITH THE RIDGE AXIS
BUILDING OVER THE PAC NW BY THE MIDDLE OF THE WEEK AND REMAINING
THERE INTO NEXT WEEKEND. -PETRUCELLI
&&
.AVIATION...FOR THE 28/06Z TAF CYCLE...SHOWERS WILL DIMINISH FROM
THE NORTH THROUGH THE NIGHT. CONDITIONS ARE GENERALLY EXPECTED TO BE
VFR AT THE TERMINALS EXCEPT FOR BRIEF MVFR IN SHOWERS. THERE MAY BE
ENOUGH CLEARING BY SATURDAY MORNING FOR SOME LOWER STRATUS TO
DEVELOP WITH MVFR OR IFR CIGS, MAINLY NORTH COAST AND UMPQUA BASIN.
SKIES SHOULD ALL CLEAR TO VFR BY LATE TOMORROW MORNING WITH GUSTY
NORTH WINDS DEVELOPING IN THE AFTERNOON. -WRIGHT
&&
.MARINE...UPDATED 4 PM PST, FRIDAY, 27 FEB, 2015...LOW PRESSURE
ALONG THE COAST WILL MOVE SOUTH OF THE AREA TONIGHT. MODERATE
NORTHWEST WINDS AND SHOWERS WILL PERSIST THROUGH TONIGHT AND THERE
IS A SLIGHT CHANCE OF THUNDERSTORMS. ANY THUNDERSTORMS MAY PRODUCE
HEAVY RAIN. NORTHERLY WINDS WILL INCREASE SATURDAY INTO SATURDAY
EVENING AND WILL BE STRONGEST IN THE OUTER WATERS SOUTH OF CAPE
BLANCO. GALE FORCE WINDS ARE BECOMING MORE LIKELY DURING THIS TIME
PERIOD...AND VERY STEEP AND HAZARDOUS SEAS WILL ACCOMPANY THESE
STRONG WINDS. WINDS AND SEAS WILL DIMINISH SOME LATE SATURDAY
NIGHT...BUT THE THERMAL TROUGH PATTERN AND GUSTY NORTH WINDS AND
STEEP SEAS...MAINLY SOUTH OF CAPE BLANCO...WILL CONTINUE INTO NEXT
WEEK. SK
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 7 AM PST THIS MORNING FOR
ORZ027-028-617-621-623-624.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 4 AM
PST SUNDAY FOR PZZ350-356.
HAZARDOUS SEAS WARNING FROM 10 AM THIS MORNING TO 4 AM PST
SUNDAY FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST MONDAY
FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST SUNDAY FOR PZZ370.
GALE WATCH FROM THIS AFTERNOON THROUGH LATE TONIGHT FOR PZZ376.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST MONDAY FOR PZZ376.
$$
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
925 AM MST SAT FEB 28 2015
...A PROLONGED WET WINTER WEATHER EVENT IS IN STORE FOR THE DESERT
SOUTHWEST SUNDAY THROUGH LATE MONDAY...
&&
.SYNOPSIS...
LOW PRESSURE WILL SLOWLY APPROACH THE AREA THIS WEEKEND...BRINGING
MOISTURE INTO THE REGION ALONG WITH INCREASING CHANCES OF SHOWERS
SUNDAY AND MONDAY. PERIODS OF HEAVY RAIN ARE POSSIBLE AT TIMES
ESPECIALLY SUNDAY NIGHT THROUGH MONDAY AFTERNOON. COOLER
TEMPERATURES WILL ALSO ACCOMPANY THIS STORM WITH BELOW NORMAL
READINGS EXPECTED MONDAY THROUGH LATE WEEK.
&&
.DISCUSSION...
MORNING SATELLITE LOOPS AND 12Z RAOBS PLOT THE LARGE UPPER LOW OVER
NORTHERN NV/CA WITH A BROAD SWATH OF MID AND UPPER JET ENERGY
CUTTING ONSHORE OVER CENTRAL CA OFF THE PACIFIC AND STRETCHING
ACROSS THE ENTIRE SOUTHERN CONUS. 300MB JET LEVEL WINDS REMAIN
UNIDIRECTIONAL FROM THE WEST. THROUGH THE 700-500MB LAYER...WINDS
BECOME MORE DIVERGENT ACROSS CENTRAL AZ AND ARE MORE FAVORABLY
ORIENTED TO THE MOGOLLON RIM/NORTHERN AZ HIGHER TERRAIN. IN RESPONSE
TO THE OVERHEAD JET...WINDY TO LOCALLY GUSTY CONDITIONS WILL
CONTINUE OVER THE SOUTHEAST CA HIGHER TERRAIN AND THE CO RIVER
VALLEY. THESE DOWNSLOPE WINDS WILL ALSO KEEP ANY THREAT OF PRECIP
OUT OF THE SOUTHEAST CA FORECASTS FOR THE DAY.
MOSTLY LIGHT PRECIP/SHOWER ACTIVITY BEGAN IN THIS "LIFT" REGION
OVERNIGHT ACROSS PORTIONS OF THE RIM AND HAVE SLOWLY STRETCHED BACK
DOWN ACROSS THE PHX METRO...FAVORING MOSTLY THE NORTH AND WEST
VALLEY LOCALES. GAUGES SO FAR WITH THE HEALTHIEST RAINFALL TOTALS
LIE ACROSS NORTHERN MARICOPA COUNTY ALONG THE CAVE CREEK DRAINAGE
WITH 6-HR TOTALS IN THE 0.10 TO NEAR 0.20" RANGE. OTHER WIDELY
SCATTERED RAINFALL REPORTS INCLUDE TRACE AMOUNTS OVER THE NORTHERN
PHX VALLEY AND A COUPLE HUNDREDTHS OUT IN THE VICINITY OF LUKE AFB.
AS THE PREVIOUS SHIFT PUT IT...TODAY WILL BE MORE ABOUT WORKING UP
MOISTURE CONTENT IN THE BOUNDARY LAYER. AREA PWATS ARE ALREADY UP
AND ABOVE NORMAL VALUES...165 PERCENT OUT OF SAN DIEGO WITH A DEEP
MARINE LAYER TO BE WORKED EASTWARD...126 PERCENT UP FOR FLAGSTAFF
AND 200 PERCENT FOR TUCSON. WITH SOME MID TO UPPER LEVEL JET SUPPORT
AND DIVERGENT PROFILE THROUGH THE MID LEVELS...ISOLATED TO WIDELY
SCATTERED SHOWERS OVER PORTIONS OF SOUTH-CENTRAL AZ WILL BE THE
REGIME TODAY. GRIDDED PRECIPITATION GUIDANCE HAS BEEN PRESENTING A
FAIRLY CONSISTENT FORECAST...WITH ISOLATED TO SCATTERED SHOWER
COVERAGE FROM MARICOPA COUNTY EAST TO NORTHEASTWARD ON AND OFF
THROUGH THE DAY. MADE ONLY MINOR BLENDS TO THE PREVIOUS FORECAST
POPS GRIDS AND WENT WITH COVERAGE WORDING FOR THE WEATHER GRIDS
TODAY /THROUGH 29/00Z/.
FORECAST CHALLENGE GETTING LATER INTO THE DAY WILL BE TO WATCH FOR
ANY FURTHER TIMING SLIPS IN OUR HEAVIEST PRECIPITATION WINDOW /LATE
SUNDAY THROUGH LATE MONDAY/ FROM THE 12Z DETERMINISTIC AND ENSEMBLE
MODEL SUITES. REST OF DISCUSSION BELOW STILL APPLIES.
&&
.PREVIOUS DISCUSSION /ISSUED AT 305 AM MST/...
A COUPLE OF THINGS TO ADDRESS THIS MORNING WITH RESPECT TO THE
POTENTIAL FOR RAINFALL ACROSS THE AREA THIS WEEKEND INTO EARLY NEXT
WEEK. AS HAS BEEN THE CASE FOR THE LAST SEVERAL DAYS...ALL
OPERATIONAL MODELS ARE IN AGREEMENT THAT THE UPSTREAM LOW WILL SAG
SOUTHWARD...DEEPEN...AND RETROGRADE WEST OF SAN DIEGO THIS WEEKEND.
THIS STILL LOOKS ON TARGET HOWEVER THERE ARE ONCE AGAIN SIGNALS IN
THIS MORNING`S 00Z GUIDANCE TO SUGGEST PRECIP WILL BE SLOW TO ARRIVE
ACROSS THE AREA...ESPECIALLY IN THE PHOENIX METRO.
CONCEPTUALLY...MUCH OF TODAY WILL BE SPENT MOISTENING THE BOUNDARY
LAYER AS THE LOW IS STILL SEVERAL HUNDRED MILES AWAY AND HAS YET TO
TAP INTO THE DEEPER/MORE SUBSTANTIAL SUBTROPICAL MOISTURE SOURCE
SOUTH OF BAJA CALIFORNIA. IN ALL LIKELIHOOD THERE WILL BE SCATTERED
SHOWERS TO THE NORTH AND EAST OF PHOENIX WITH A FEW ISOLATED SHOWERS
ACROSS THE METRO...BUT THAT`S ABOUT IT. THIS IDEA IS SUPPORTED BY
ALL OPERATIONAL 18Z AND 00Z DETERMINISTIC MODELS AND IS ALSO WITHIN
THE WINDOW OF THE LATEST /07Z AND 08Z/ HRRR RUNS. MADE SOME DOWNWARD
ADJUSTMENTS TO THE POPS FOR TODAY ESPECIALLY ACROSS THE LOWER
DESERTS ALONG WITH SOME UPWARD ADJUSTMENTS TO TEMPERATURES. NOT
GOING TO REMOVE THE MENTION OF PRECIP ALTOGETHER FOR THE PHOENIX
AREA AS THERE COULD EASILY BE 20-30 PERCENT COVERAGE ACROSS THE
METRO. BUT FOR THE MOST PART TODAY LOOKS TO BE MORE DRY THAN WET.
BY THIS EVENING THE LOW WILL BE LOCATED WEST OF LOS ANGELES BUT
STILL TOO FAR NORTH TO TAP INTO THE AFOREMENTIONED SUBTROPICAL
MOISTURE PLUME NEAR THE BAJA SPUR. THE MODELS ARE NOW SUGGESTING THE
BEST CHANCE OF PRECIP ACROSS SOUTHEAST CALIFORNIA AND FAR SW ARIZONA
WON`T OCCUR UNTIL DURING THE DAY ON SUNDAY...ABOUT 6-12 HRS SLOWER
THAN PREVIOUSLY INDICATED. FOLLOWING THAT TREND...PRECIP ISN`T
EXPECTED TO MOVE INTO THE PHOENIX AREA UNTIL MUCH LATER AS WELL
/SUNDAY AFTERNOON OR EVENING/. THUS I MADE SOME ADJUSTMENTS TO THE
POPS/QPF AND FLOOD WATCH TIMING FOR THIS EVENT TO BETTER MATCH THE
00Z DETERMINISTIC AND PROBABILISTIC GUIDANCE. I`M NOT REMOVING POPS
ALTOGETHER FOR THE PHOENIX AREA SUNDAY BUT DRASTICALLY TRIMMING
VALUES AND HIGHLIGHTING SUNDAY EVENING THROUGH MID-DAY MONDAY AS THE
PRIME-TIME FOR SHOWERS ACROSS THE AREA. POPS DURING THIS SUNDAY
EVENING-MONDAY TIME PERIOD STILL LOOK GOOD IN THE 80-100 PERCENT
RANGE AS THIS IS WHEN THE UPPER LOW FINALLY GETS A KICK FROM ANOTHER
UPSTREAM TROUGH. ALSO NOTED A SOMEWHAT CONCERNING REDUCTION IN
ENSEMBLE QPF THIS MORNING WITH THE HIGHEST MEMBERS INDICATING AROUND
1 INCH OF PRECIP IN THE PHOENIX AREA...WITH A MEAN MORE IN THE
0.5-0.75 INCH REALM. PERHAPS THIS IS A RESULT OF THE MORE
PROGRESSIVE NATURE OF THE TROUGH VS THE SOMEWHAT NEGATIVELY TILTED
DEPICTION THE MODELS WERE INDICATING THE PAST FEW DAYS.
REGARDLESS...THERE WILL ALMOST CERTAINLY BE LOCALLY HIGHER VALUES
ESPECIALLY IN THE OROGRAPHICALLY FAVORED AREAS NORTH/EAST OF PHOENIX
WITHIN THE INHERITED FLOOD WATCH BUT I WILL MAKE SOME REDUCTIONS TO
THE TOTAL QPF FORECAST ESPECIALLY ACROSS THE SOUTHERN HALF OF THE
FORECAST AREA. WILL ADJUST THE FLOOD WATCH TO RUN FROM 5 PM SUNDAY
TO 5 PM MONDAY.
RAINFALL WILL QUICKLY MOVE THROUGH THE AREA MONDAY BUT ONE MORE
UPSTREAM TROUGH WILL DIVE SOUTHWARD TUESDAY AFTERNOON. PRECIP
CHANCES WITH THIS TROUGH WILL BE HIGHEST NORTH/EAST OF PHOENIX BUT
STILL THINK THERE COULD BE SOME SCATTERED SHOWERS ACROSS THE
DESERTS. WILL LEAVE THE FORECAST FOR TUESDAY LARGELY UNCHANGED WITH
20-30 POPS AROUND PHOENIX AND 40-50 POPS IN THE HIGHER TERRAIN.
AFTER THAT...DRY NORTHWESTERLY FLOW WILL PERSIST THROUGH MID
WEEK...FOLLOWED BY LATE WEEK RIDGING/WARMING. TEMPERATURES WILL
REACH THEIR LOWEST VALUES ON MONDAY AND WILL SLOWLY REBOUND BACK
INTO THE UPPER 70S/LOWER 80S BY LATE NEXT WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
AN APPROACHING WEATHER SYSTEM WILL BRING BREEZY SOUTHWESTERLY WINDS
DURING THE DAYTIME HOURS TODAY WITH GUSTS APPROACHING 25 KNOTS THIS
AFTERNOON. INCREASING LOW LEVEL MOISTURE WILL CAUSE PERIODIC LOW VFR
CIGS THROUGH THIS EVENING AND THEN MORE PERSISTENT BROKEN CIGS AT
5-6K FEET LATE TONIGHT. THERE IS A CHANCE OF FEW-SCT SHOWERS MAINLY
ACROSS THE NORTHERN FRINGES OF THE PHOENIX AREA THROUGHOUT THE
PERIOD WITH INCREASING CHANCES ON SUNDAY. CONFIDENCE IS TOO LOW TO
INCLUDE IN THE TAFS AT THIS TIME...EXCEPT FOR VCSH AT KSDL.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
LOW PRESSURE APPROACHING FROM THE NORTHWEST WILL KEEP GUSTY
SOUTHWESTERLY WINDS GOING THROUGH EARLY THIS EVENING WITH SOME GUSTS
APPROACHING 35 KNOTS THIS AFTERNOON. THERE IS AN OUTSIDE CHANCE OF
BLOWING DUST POSSIBLE FOR A TIME THIS AFTERNOON AT BOTH TAF SITES.
INCREASING MOISTURE LEVELS THROUGH THE COLUMN WILL ALLOW LOW VFR
CIGS TO DEVELOP THIS EVENING AND PERSIST THROUGH THE OVERNIGHT
HOURS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
COOL AND WET CONDITIONS WILL BE PRESENT ON MONDAY AND LIKELY INTO
TUESDAY WITH THE BEST CHANCES FOR WIDESPREAD RAINS ON MONDAY. THERE
WILL BE A CHANCE OF A FEW THUNDERSTORMS ON MONDAY. HUMIDITIES WILL
BE WELL ABOVE TYPICAL VALUES THROUGH TUESDAY BEFORE MINIMUM VALUES
FALL BACK INTO THE TEENS STARTING THURSDAY AFTERNOON. PERIODS OF
BREEZY SOUTHWESTERLY WINDS CAN BE EXPECTED ON MONDAY AND AGAIN ON
WEDNESDAY. HIGH TEMPERATURES ACROSS THE DESERTS WILL ONLY REACH INTO
THE 60S THROUGH WEDNESDAY. HIGH PRESSURE BRINGING WARMER AND DRIER
WEATHER SHOULD MOVE IN STARTING LATER WEDNESDAY AND SHOULD PERSIST
THROUGH THE END OF THE WEEK.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLOOD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON
AZZ021>024.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...NOLTE
PREVIOUS DISCUSSION...LEINS
AVIATION...KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
935 AM PST SAT FEB 28 2015
.UPDATE...
THE SNOW BAND ENDED UP DEVELOPING FURTHER NORTH THAN EXPECTED, AND
JUST SHOWS THE DIFFICULT NATURE OF SLIDER SYSTEMS. AS FOR THIS
MORNING, UPDATING TO EXPIRE THE WINTER WEATHER ADVISORY FOR THE
SIERRA FRONT. WHILE THE BAND OF SNOW NEAR AND NORTH OF I-80
CONTINUES, THE HIGHER SUN ANGLE OF LATE FEBRUARY IS HELPING TO
MELT THE SNOW ON ROADS IN THE LOWER ELEVATIONS. MANY ROAD TEMPS
ARE IN THE MID 30S AND WEBCAMS SHOWING ROADS JUST WET. WHILE THERE
COULD BE A FEW LOCALIZED SLUSHY SPOTS THE NEXT HOUR, EXPECT THESE
TO DIMINISH. THE HRRR ALSO SHOWS THE BAND DISSIPATING IN THE NEXT
HOUR OR TWO. BASED ON CURRENT TRENDS, THIS APPEARS TOO FAST, BUT
STILL EXPECT A SLOW WEAKENING INTO EARLY AFTERNOON.
AS FOR TAHOE, ROADS ARE STILL AN ISSUE THERE AROUND THE NORTH
SHORE AND I-80 SO THE ADVISORY STILL LOOKS GOOD. ADDTIONAL
ACCUMULATIONS OF 1-2 INCHES ARE LIKELY IN THE BAND WITH LOCALIZED
AMOUNTS UP TO 4". WALLMANN
&&
.PREVIOUS DISCUSSION... /ISSUED 318 AM PST SAT FEB 28 2015/
SYNOPSIS...
SNOW SHOWERS ASSOCIATED WITH A WINTER SYSTEM WILL CONTINUE THROUGH
THE WEEKEND. ACCUMULATING SNOW AND DIFFICULT TRAVEL ARE LIKELY IN
THE SIERRA WITH LIGHTER AMOUNTS AND MORE LOCALIZED TRAVEL ISSUES IN
WESTERN NEVADA. THIS SYSTEM WILL EXIT SUNDAY WITH A WEAKER SYSTEM
EXPECTED MONDAY AFTERNOON KEEPING TEMPERATURES BELOW NORMAL. DRY
CONDITIONS AND A WARMING TREND ARE EXPECTED LATER NEXT WEEK.
SHORT TERM...
THE CORE OF AN UPPER LEVEL LOW IS BEGINNING TO SETTLE ACROSS NORTHERN
CALIFORNIA WITH A DEFORMATION AREA DEVELOPING ACROSS THE NORTHERN
SIERRA. SNOW LEVELS ARE CURRENTLY NEAR 4500 FEET WITH SNOW BEGINNING
TO MIX IN WITH RAIN AROUND DOWNTOWN RENO. NUMEROUS CHAIN CONTROLS
EXTEND ACROSS THE TAHOE BASIN INCLUDING STRETCHES OF INTERSTATE 80
THROUGH THE SIERRA TO JUST WEST OF RENO AND HWY 395 NORTH OF RENO AS
OF 2AM. SLICK AND ICY ROADWAYS CAN BE EXPECTED THROUGH THE MORNING
WHERE SNOW WILL CONTINUE TO ACCUMULATE ON ROAD SURFACES.
MAIN IMPACTS FROM SNOWFALL WILL CONTINUE OVER THE NEXT 8-10 HOURS
ACROSS THE RENO, CARSON CITY, MINDEN REGION. THESE HAVE BEEN THE
FAVORED REGIONS FOR BANDED SNOWFALL TO DEVELOP BENEATH THE AREA OF
DEFORMATION FORCING AND INSTABILITY. LATEST RADAR AND SATELLITE
TRENDS COUPLED WITH SHORT RANGE HI-RES HRRR MODEL INDICATE MAIN BAND
OF SNOWFALL POSITIONED FROM RENO TO CARSON CITY THROUGH ABOUT 10AM
THEN SHIFTING SOUTH THROUGH DOUGLAS, ALPINE, AND NORTHERN MONO
COUNTY INTO THE EARLY AFTERNOON. ADDITIONAL SNOWFALL ACCUMULATIONS
OF 1-2 INCHES IS POSSIBLE THROUGH EARLY AFTERNOON IN FAR WESTERN
NEVADA WITH 2-4" POSSIBLE AT LAKE LEVEL. WINTER WEATHER ADVISORIES
WILL CONTINUE THROUGH LATE MORNING FOR FAR WESTERN NEVADA AND
THROUGH THE AFTERNOON ACROSS THE LAKE TAHOE BASIN.
SNOW SHOWERS WILL SHIFT SOUTH INTO MONO COUNTY THROUGH THE AFTERNOON
WITH 1-2 INCHES OF SNOWFALL POSSIBLE THROUGH THE HWY 395 CORRIDOR.
COLD TEMPERATURES ALOFT WILL ALLOW FOR INCREASED INSTABILITY WITH
DAYTIME HEATING WHICH WILL PRODUCE THE POSSIBILITY OF THUNDER
THROUGH THE AFTERNOON. LIGHT SNOW SHOWERS WILL CONTINUE THROUGH
SUNDAY AFTERNOON IN MONO COUNTY WITH 6"+ POSSIBLE ALONG THE CREST.
ANOTHER DISTURBANCE FOLLOWS SUIT ON MONDAY BUT IS SHOWING SIGNS OF
SPLITTING WITH THE SOUTHERN SHORTWAVE TRACKING OFF THE CENTRAL
CALIFORNIA COAST BY MONDAY AFTERNOON. THIS SHOULD PRESENT SOME
ADDITIONAL CHANCES FOR SNOW SHOWERS MAINLY ACROSS THE SIERRA. THIS
DOES NOT APPEAR TO BE A BIG SNOW PRODUCER BY ANY MEANS, BUT A FEW
ADDITIONAL INCHES OF SNOWFALL STILL COULD CREATE SOME TRAVEL
IMPACTS ACROSS SIERRA PASSES LATE MONDAY AFTERNOON AND EVENING.
FUENTES
LONG TERM...TUESDAY THROUGH FRIDAY...
MODELS CONTINUE TO LOCK IN ON A FARTHER EAST (OVER EASTERN NEVADA,
IDAHO AND UTAH) SOLUTION FOR AN UPPER WAVE MOVING DOWN THE EAST SIDE
OF A PACIFIC RIDGE. THIS WILL MEAN A MOST LIKELY DRY AND COOL NORTH
FLOW ON TUESDAY FOR WESTERN NEVADA AND EASTERN CALIFORNIA. STILL, I
HAVE LEFT THE SLIGHT CHANCE OF SHOWERS OVER MONO AND MINERAL
COUNTIES TUESDAY AS A NOD TOWARDS THE FARTHER WEST SOLUTIONS SUCH AS
THE 27/12Z AND 28/00Z OPERATIONAL ECMWF. THESE SHOWERS MAY BE ABLE
TO BE PULLED ALTOGETHER SOON IF MODELS CONTINUE TO TREND EASTWARD ON
THE UPPER DISTURBANCE.
FROM WEDNESDAY THROUGH FRIDAY, GUIDANCE IS IN GOOD AGREEMENT WITH A
RIDGE REBUILDING INLAND ACROSS THE GREAT BASIN, RESULTING IN DRY
CONDITIONS AND A GRADUAL WARMING TREND. AFTERNOON TEMPERATURES WILL
RISE BACK TO NEAR AVERAGE ON THURSDAY BEFORE RISING ABOVE AVERAGE ON
FRIDAY. SNYDER
AVIATION...
UPPER LOW DIRECTLY OVER NORTHWEST/WESTERN NEVADA IS BRINGING
WIDESPREAD -SN WITH IFR (LOCALLY LIFR) CONDITIONS TO FAR WESTERN
NEVADA, WITH AREAS OF MVFR CIGS/VIS FOR THE LAKE TAHOE AREA AND OUT
TOWARDS KNFL/KLOL/KHTH (CIGS). THE SHORT RANGE HIGH RESOLUTION MODEL
(HRRR) INDICATES WIDESPREAD -SN OVER WESTERN NEVADA THIS MORNING AS
THE UPPER LOW SLOWLY DROPS SOUTH. THIS SHOULD KEEP LOWERED CIGS/VIS
AND WIDESPREAD TERRAIN OBSCURATION GOING IN -SN THIS MORNING FOR
WESTERN NEVADA, WITH AREAS OF LOW CIGS/VIS IN THE TAHOE AREA MAINLY
SOUTH OF KTRK. IMPROVEMENT IS EXPECTED THIS AFTERNOON FOR KRNO/KCXP
AS THE MAIN AREA OF SNOW SHIFTS SOUTH. PAVEMENT TEMPERATURES WILL
REMAIN NEAR FREEZING THROUGH MID MORNING FOR FAR WESTERN NEVADA AND
THE NORTHERN SIERRA SO UNTREATED SURFACES WILL SEE A LIGHT
ACCUMULATION.
FARTHER SOUTH INTO MONO AND MINERAL COUNTIES, WORSENING CIGS/VIS ARE
LIKELY TO MOVE IN LATER THIS AFTERNOON AND TONIGHT AS THE UPPER LOW
DROPS SOUTH. LIGHT SNOW ACCUMULATIONS FOR TERMINALS IN MONO COUNTY
ARE LIKELY, WITH A POSSIBLE LIGHT ACCUMULATION OUT IN MINERAL AND
SOUTHERN LYON COUNTIES BELOW 5000 FEET TONIGHT. OUT IN THE BASIN AND
RANGE (KLOL/KNFL), ACCUMULATIONS ARE UNLIKELY WITH THE MAIN ISSUE
LOWERED CIGS AND HIGHER TERRAIN OBSCURATION THIS MORNING. SNYDER
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 4 PM PST THIS AFTERNOON NVZ002.
CA...WINTER WEATHER ADVISORY UNTIL 4 PM PST THIS AFTERNOON CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
342 PM CST SAT FEB 28 2015
...UPDATED SHORT TERM SECTION...
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 341 PM CST SAT FEB 28 2015
AS WE REMAIN IN THIS BROAD, CYCLONICALLY-CURVED FLOW PATTERN, WE
WILL CONTINUE TO SEE THE TREND OF MINOR SHORTWAVE PERTURBATIONS
ROTATING ACROSS SOUTHWESTERN KANSAS...PROVIDING US WITH CHANCES FOR
LIGHT PRECIPITATION AS WE SEE SUBTLE DEFORMATION/CONVERGENCE IN THE
LOWER-MID TROPOSPHERE ALONG THE BAROCLINIC ZONE. THE NEXT IN THE
SERIES WILL BE TONIGHT AFTER THE BREAK WE HAD THIS AFTERNOON. POPS
WILL BE INCREASED BACK UP IN TO THE LIKELY CATEGORY WITH A
CONTINUATION OF THE WINTER WEATHER ADVISORY. THE VERY LATEST 18Z
RUNS OF THE NAM12 AND THE HRRR/RAP HAVE THROWN A LITTLE WRINKLE IN
THE NEAR TERM FORECAST. THE NAM12 SUGGESTS THE NEXT LIGHT
PRECIPITATION EVENT WILL START ABOUT 6 HOURS SOONER THAN PREVIOUSLY
THOUGHT (WHICH IS SIGNIFICANT AT THIS CLOSE OF A TIME RANGE) WHEREAS
THE RAP AND HRRR REALLY SHOW NOTHING MUCH AT ALL. IT REALLY IS A
FINE LINE BETWEEN NO PRECIP AT ALL AND LIGHT ACCUMULATING PRECIP IN
THIS FLOW REGIME, AS MUCH DOWNSLOPE AS THERE IS (YET MOIST). THE
SHORT TERM MODELS SHOW A WARMING OF THE 850-750MB LAYER TO THE POINT
THAT A SLIGHT WARM NOSE ABOVE 0C WILL DEVELOP. THIS WILL FAVOR SLEET
AS A PRECIPITATION TYPE LATE TONIGHT, PARTICULARLY SOUTH OF THE
ARKANSAS RIVER. IT SHOULD BE NOTED THAT, AGAIN, ANY PRECIPITATION
TONIGHT WOULD BE QUITE LIGHT AND MAY NOT EVEN HAPPEN AT ALL. THE
INCOMING SWING SHIFT WILL NEED TO WATCH TRENDS TO SEE OF THE WINTER
WX ADVISORY IS STILL NEED THROUGH THE OVERNIGHT HOURS AND IN TO THE
MORNING SUNDAY. TEMPERATURES OVERNIGHT WILL REMAIN QUASI-STEADY
AROUND 20 DEGREES WITH THE CONTINUED SOUTH WINDS AND CLOUDS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 214 PM CST SAT FEB 28 2015
A WEAK DISTURBANCE WILL BRING A SLIGHT CHANCE OF LIGHT SNOW
ACROSS FAR WESTERN AND WEST CENTRAL KANSAS SUNDAY NIGHT. LITTLE TO
NO ACCUMULATION IS EXPECTED OVERNIGHT. LOW LEVEL WARM AIR
ADVECTION WILL INCREASE THROUGHOUT THE DAY MONDAY WITH WINDS
SHIFTING TO MORE OF A SOUTHERLY DIRECTION. TEMPERATURES WILL
INCREASE TO ABOVE FREEZING MONDAY INTO MONDAY NIGHT LEADING TO
LIGHT RAIN OR DRIZZLE TO FALL IN SOME LOCATIONS. OTHERWISE EXPECT
MOSTLY CLOUDY SKIES TO CONTINUE. AS FOR TEMPERATURES, LOWS SUNDAY
NIGHT LOOK TO DIP TO AROUND 20 DEGREES WITH HIGHS MONDAY INTO
MONDAY NIGHT REACHING TO THE MID TO UPPER 30S.
MEDIUM RANGE MODELS THEN INDICATE THAT A STRONG UPPER LEVEL
SHORTWAVE WILL MOVE SOUTHEAST OUT OF WESTERN CANADA AND INTO THE
NORTHERN ROCKIES MONDAY NIGHT THEN INTO THE CENTRAL AND NORTHERN
PLAINS TUESDAY. THIS SYSTEM WILL HELP PUSH ANOTHER STRONG COLD
FRONT ACROSS WESTERN KANSAS DURING THE DAY. AS OF NOW FRONTAL
PASSAGE LOOKS TO BE MAINLY DURING THE MORNING HOURS, BUT WITH THIS
SYSTEM BEING 3 DAYS OUT THERE COULD STILL BE SOME CHANGES AS IT
APPROACHES. NEVERTHELESS, STRONG NORTHERLY WINDS ARE ANTICIPATED
BEHIND THIS COLD FRONT WITH CONTINUED MOSTLY CLOUDY SKIES. A
CHANCE OF LIGHT SNOW WILL BE POSSIBLE TUESDAY NIGHT WITH A SLIGHT
CHANCE WEDNESDAY MORNING WITH DECREASING CLOUDINESS EXPECTED
WEDNESDAY AFTERNOON. A WIDE RANGE OF TEMPERATURES ARE ANTICIPATED
TUESDAY DUE TO THE EARLY FRONTAL PASSAGE WITH HIGHS RANGING FROM
THE LOWER 40S ACROSS WEST CENTRAL KANSAS TO MID 50S ACROSS THE
KS/OK BORDER. LOWS LOOK TO FALL INTO THE TEENS TUESDAY NIGHT WITH
HIGHS ONLY REACHING INTO THE MID 20S WEDNESDAY AFTERNOON.
THE REMAINDER OF THE FORECAST LOOKS DRY AS AN UPPER LEVEL RIDGE
BUILDS ACROSS THE WESTERN UNITED STATES. WINDS WILL GENERALLY BE
FROM THE SOUTH TO SOUTHWEST DURING THIS TIME FRAME WITH PARTLY
CLOUDY SKIES. HIGHS ARE FORECASTED TO BE IN THE LOWER 40S THURSDAY
THEN LOWER 50S FRIDAY. LOWS LOOK TO DIP INTO THE LOWER TEENS
WEDNESDAY NIGHT WITH 20S THURSDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 539 AM CST SAT FEB 28 2015
LIGHT TO MODERATE SNOW WILL PERSIST AT THAT TAF SITES ACROSS CENTRAL
AND SOUTHWEST KANSAS THROUGH MID MORNING BEFORE TAPERING OFF TO FLURRIES.
VISIBILITIES IN THE 1-3 MILE RANGE THIS MORNING WILL IMPROVE TO VFR
BEFORE LOWERING INTO THE MVFR CATEGORY AGAIN AROUND OR AFTER 00Z. MVFR
CEILINGS WILL DEGRADE TO IFR BY THIS EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 21 31 20 38 / 70 60 20 20
GCK 19 31 19 40 / 60 30 20 20
EHA 24 33 21 45 / 30 20 30 20
LBL 24 34 22 43 / 50 30 20 10
HYS 20 35 21 39 / 40 30 20 20
P28 23 32 22 39 / 60 60 10 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR KSZ046-064>066-
076>081-086>090.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM...HOVORKA_42
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
259 PM EST SAT FEB 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM EST SAT FEB 28 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A MORE SPLIT FLOW
OVER NAMERICA WITH UPR MI ON THE SRN FLANK OF A WNW FLOW ON THE SW
FLANK OF ARCTIC BRANCH CLOSED LO DRIFTING OFF THE NEWFOUNDLAND
COAST. SHRTWV RDG APRCHG THRU MN/VERY DRY AIR SHOWN ON LOCAL 00Z
RAOBS /00Z PWATS WERE ARND 0.07 INCH OR 30-35 PCT OF NORMAL/ ARE
RESULTING IN MOCLR SKIES EARLY THIS MRNG. DESPITE DRYNESS OF THIS
AIRMASS AND CHILL WITH 00Z H85 TEMPS IN THE -16 TO -17C RANGE...
STEADY WSW FLOW UNDER THE RATHER TIGHT PRES GRADIENT TO THE N OF HI
CENTER IN THE OH RIVER VALLEY HAS RESTRICTED THE DROP IN TEMP OVER
MUCH OF THE CWA...ESPECIALLY AT THE MORE EXPOSED LOCATIONS NEAR THE
LAKES...WHERE CURRENT TEMPS RANGE FM ZERO TO 10 ABOVE. BUT SOME OF
THE SHELTERED INTERIOR LOCATIONS HAVE SEEN THE MERCURY FALL TO AS LO
AS -15F TO -20F. LOOKING UPSTREAM...HI CLDS ARE STREAMING INTO MN IN
ADVANCE OF A SHRTWV MOVING E INTO NDAKOTA. BUT SINCE THE AIRMASS IN
THE NRN PLAINS IS ALSO QUITE DRY /AREA PWATS ARE UNDER 0.10 INCH AND
THE 00Z H85 AND H7 DEWPT DEPRESSIONS AT BISMARCK WERE 19C AND 30C
RESPECTIVELY/...THERE IS AN ABSENCE OF PCPN ACCOMPANYING THIS
DISTURBANCE.
MAIN FCST CONCERNS IN THE SHORT TERM WL FOCUS ON MAX TEMPS TODAY AND
IMPACT TNGT OF SHRTWV NOW MOVING THRU THE NRN PLAINS.
TODAY...SHRTWV RDG AXIS NOW IN MN IS PROGGED TO PASS THRU THE CWA
THIS AFTN. ACCOMPANYING AREA OF H85-5 RH UNDER 20 PCT WL RESULT IN
SUNSHINE FILTERED AT TIMES BY SOME HI CLDS STREAMING INTO THE AREA
IN ADVANCE OF SHRTWV THAT IS FCST TO REACH NW MN BY 00Z SUN. AS H85
TEMPS REBOUND TO ARND -14C IN THE SW FLOW ARND SFC HI PRES SHIFTING
TOWARD THE MID ATLANTIC STATES...EXPECT MAX TEMPS TO TOP OUT A
COUPLE OF DEGREES HIER THAN OBSVD YDAY...PERHAPS UP TO 25 IN THE
DOWNSLOPE AREAS NEAR LK SUP BTWN MARQUETTE AND BARAGA. THE LOWEST
TEMPS IN THE TEENS ARE LIKELY DOWNWIND OF THE ICE COVERED NRN BAY OF
GREEN BAY/LK MI.
TNGT...SHRTWV OVER NW MN IS PROGGED TO SHIFT E ACROSS NRN LK SUP AND
INTO ONTARIO JUST E OF THE LK BY 12Z ON SUN. SOME DPVA/MODEST DEEP
LYR QVECTOR CNVGC IS FCST TO INFLUENCE UPR MI AHEAD OF THE SHRTWV.
BUT MODEST MSTR INFLOW/ISENTROPIC ASCENT INTO ANTECEDENT BONE DRY
AIRMASS WL GREATLY RESTRICT POPS. IN FACT...MOST OF THE MODELS
INDICATE A MAINLY DRY OVERNGT AND GENERATE ONLY PATCHY LIGHT PCPN.
SEEMS THE BEST CHC FOR PCPN WL BE OVER LK SUP AND PERHAPS DOWNWIND
OF LK MI FM MANISTIQUE TO NEWBERRY. WL RETAIN MENTION OF SCHC
POPS...MAINLY OVERNGT. LO TEMPS TNGT COULD BE TRICKY WITH LINGERING
DRY AIR IN PLACE BEFORE THICKER CLDS ARRIVE. TENDED TO GO HIER WITH
MIN TEMPS IN THE DOWNSLOPE AREAS NEAR LK SUP IN PREVAILING SSW FLOW.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 259 PM EST SAT FEB 28 2015
GOOD AGREEMENT FM THE MODELS ON OVERALL LOOK OF LARGE SCALE PATTERN
THROUGH THE EXTENDED. TROUGH AND COLD AIR THAT HAS DOMINATED FOR
FEBRUARY EASES FIRST PART OF THE WEEK. JUST BEFORE THAT OCCURS THERE
COULD BE SOME LIGHT LAKE EFFECT SNOW SHOWERS SUNDAY NIGHT FOR AREAS
FAVORED BY WNW WINDS. SOUNDINGS INDICATE INVERSIONS UP TO 5KFT WITH
A LOT OF THE MOIST LAYER IN THE DGZ. LACK OF OPEN WATER WILL HAMPER
THE LES...BUT WILL CARRY SCATTERED POPS FOR SNOW BELTS EAST OF MQT
AND P53. LES COULD LINGER AS FLURRIES ON MONDAY MORNING...BUT WILL
OPT FOR DRY FORECAST AS HIGH PRESSURE RIDGE SHOULD BE PUTTING AN END
TO THE LES. WITH A NW LOW-LEVEL FLOW...MODELS HANG ON TO LOW CLOUDS
PROBABLY ENHANCED DUE TO DAYTIME HEATING. MODELS MAY BE OVERDOING
LOW-LEVEL RH THOUGH...SO WILL JUST GO PARTLY CLOUDY FOR DAYTIME ON
MONDAY. HIGHS BOUNCE UP INTO THE 20S...THOUGH WILL REMAIN ONLY TO
AROUND 20 OVER EAST WITH LINGERING NW WINDS OFF ICE OF LK SUPERIOR
MOST OF THE DAY.
CLOUDS THICKEN ON MONDAY NIGHT AHEAD OF DOUBLE BARRELLED LOW
PRESSURE SYSTEM THAT MOVES OVER THE REGION ON TUESDAY. TEMPS MAY
FALL QUICKLY OVER THE EAST CWA ON MONDAY NIGHT...BUT WILL BE IN THE
TEENS ELSEWHERE. ON TUESDAY...NORTHERN STREAM LOW IS THE ONE
AFFECTING ALASKA THIS AFTN AND THE SOUTHERN STREAM LOW IS FORECAST
TO EMERGE OUT OF GENERAL TROUGHING CURRENTLY OVER THE SOUTHWEST
CONUS. H85-H7/H7-H5 Q-VECTOR CONVERGENCE AND MOISTURE ADVECTION
AHEAD OF SFC-H85 TROUGHS WITH H7 MIXING RATIOS 2-3 G/KG SUPPORT
POTENTIAL FOR MODERATE SNOWFALL OVER EAST HALF OF UPR MICHIGAN.
BLEND OF QPF ALONG WITH EXPECTED SLR/S IN THE 13-18:1 RANGE POINT TO
SNOWFALL RANGING FM 2-4 INCHES/3-5 INCHES. KIND OF SEEMS THAT THERE
MAY BE TWO MAIN TIMES OF SNOW WITH THE SYSTEM...LATE MONDAY NIGHT
INTO TUESDAY MORNING...THEN AGAIN TUESDAY AFTN INTO EARLY TUESDAY
EVENING. MODELS ARE LOCKED IN THAT THE TUESDAY AFTN AND TUESDAY
EVENING TIME FRAME WILL FEATURE THE HEAVIEST SNOW...POSSIBLY WITH
SNOWFALL RATES AROUND 1 INCH PER HOUR. IMPACT COULD BE ON THE HIGHER
SIDE TOO AS THE HEAVIEST SNOW COULD FALL DURING THE AFTN AND EVENING
COMMUTE. WILL CONTINUE TO MENTION IN THE HWO AND EHWO GRAPHICS.
REPRIEVE IN THE COLD AIR IS BRIEF AS MORE COLD AIR...CURRENTLY
UPSTREAM OF THE LOW PRESSURE SYSTEM OVER ALASKA...CHARGES IN LATE
TUESDAY NIGHT INTO WEDNESDAY AND LINGERS THROUGH LATE WEEK. RETURN
OF THE COLD WITH H85 TEMPS BLO -20C WILL LEAD TO LAKE EFFECT FOR NW
FLOW AREAS. SOUNDINGS SHOW INVERSIONS START OUT AT 5KFT ON TUESDAY
NIGHT OVER EASTERN LK SUPERIOR BUT RISE UP TO 8KFT ON WEDNESDAY.
EXTENT OF OVER-WATER INSTABILITY AND DEPTH OF THE CONVECTIVE LAYER
SUGGESTS LOCALLY MODERATE SNOW SHOWERS WILL BE POSSIBLE FOR MAINLY
WNW-NW FLOW AREAS. OVERALL THE LOW VSBY WITH SMALLER SNOWFLAKES WILL
BE THE LARGER IMPACT. WINDS 25-30 KTS SO MAY ALSO HAVE BLSN ALONG
THE SHORE...ESPECIALLY IN THE SNOW BELTS EAST OF MQT. WITH ENOUGH
MOISTURE INLAND ON WEDNESDAY...MAY ALSO SEE DIURNALLY ENHANCED SNOW
SHOWERS WITH PERIODS OF GUSTY WINDS/LOWER VSBY. WINDS BACK W-WSW ON
WEDNESDAY NIGHT WHICH WILL END THE LES ALONG MOST OF LK SUPERIOR.
TEMPS INLAND WILL FALL OFF WELL BLO ZERO. WINDS WILL BE ON THE
DECLINE BUT MAY STILL BE STRONG ENOUGH TO PRODUCE NEAR ADVISORY WIND
CHILLS THURSDAY MORNING OVER PARTS OF THE CWA.
HIGH PRESSURE BUILDING OVER THE NORTHERN PLAINS BY THURSDAY SLIDES
TO THE OHIO VALLEY INTO FRIDAY AS LOW PRESSURE SYSTEM CROSSING
NORTHERN ONTARIO PUSHES A WARM FRONT ACROSS THE UPPER GREAT LAKES.
MID-LEVEL MOISTURE H85-H7 AND WEAK LIFT MAY TRIGGER A FEW SNOW
SHOWERS OR FLURRIES THURSDAY NIGHT INTO FRIDAY MORNING. GFS AND
ECMWF BOTH SHOW MAIN FORCING STAYING OVER LK SUPERIOR AND TO THE
NORTH. ANOTHER COLD FRONT WORKS THROUGH ON FRIDAY NIGHT WITH MORE
COLD AIR SETTLING OVER THE AREA BY NEXT SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1244 PM EST SAT FEB 28 2015
A DRY SW FLOW AROUND HIGH PRES SHIFTING TOWARD THE MID ATLANTIC
STATES WILL BRING VFR CONDITIONS TO KIWD/KCMX/KSAW THRU THIS FCST
PERIOD. SOME THICKER CLOUDS WILL ARRIVE TONIGHT IN ADVANCE OF AN
APPROACHING LOW PRES TROF...BUT THE LOW-LEVELS SHOULD REMAIN DRY
ENOUGH TO MAINTAIN VFR CIGS EVEN IF THERE IS SOME VERY LIGHT SNOW OR
FLURRIES. GUSTIER W WINDS WILL DEVELOP LATE SUN MORNING/EARLY AFTN
AT KCMX AFTER SFC TROF PASSAGE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 259 PM EST SAT FEB 28 2015
NO GALES EXPECTED INTO NEXT WEEK. WSW WINDS TO 30 KTS EXPECTED ON
SUNDAY OVER WESTERN HALF OF LK SUPERIOR WITH NW WINDS TO 30 KTS
TUESDAY NIGHT INTO WEDNESDAY OVER THE EASTERN HALF OF LK SUPERIOR IN
WAKE OF A STRONGER LOW PRESSURE SYSTEM AND COLD FRONT THAT CROSS THE
UPPER GREAT LAKES ON TUESDAY. OTHERWISE...WINDS WILL BE 20 TO 25 KTS
THROUGH THE WEEK. THE STRONG WINDS WILL LIKELY ALTER THE COVERAGE OF
THE ICE SOMEWHAT ON LK SUPERIOR...BUT IN GENERAL EXPECT THE HIGHER
COVERAGE TO PERSIST AS DESPITE SOME WARMING...TEMPERATURES WILL STAY
BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1245 PM EST SAT FEB 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM EST SAT FEB 28 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A MORE SPLIT FLOW
OVER NAMERICA WITH UPR MI ON THE SRN FLANK OF A WNW FLOW ON THE SW
FLANK OF ARCTIC BRANCH CLOSED LO DRIFTING OFF THE NEWFOUNDLAND
COAST. SHRTWV RDG APRCHG THRU MN/VERY DRY AIR SHOWN ON LOCAL 00Z
RAOBS /00Z PWATS WERE ARND 0.07 INCH OR 30-35 PCT OF NORMAL/ ARE
RESULTING IN MOCLR SKIES EARLY THIS MRNG. DESPITE DRYNESS OF THIS
AIRMASS AND CHILL WITH 00Z H85 TEMPS IN THE -16 TO -17C RANGE...
STEADY WSW FLOW UNDER THE RATHER TIGHT PRES GRADIENT TO THE N OF HI
CENTER IN THE OH RIVER VALLEY HAS RESTRICTED THE DROP IN TEMP OVER
MUCH OF THE CWA...ESPECIALLY AT THE MORE EXPOSED LOCATIONS NEAR THE
LAKES...WHERE CURRENT TEMPS RANGE FM ZERO TO 10 ABOVE. BUT SOME OF
THE SHELTERED INTERIOR LOCATIONS HAVE SEEN THE MERCURY FALL TO AS LO
AS -15F TO -20F. LOOKING UPSTREAM...HI CLDS ARE STREAMING INTO MN IN
ADVANCE OF A SHRTWV MOVING E INTO NDAKOTA. BUT SINCE THE AIRMASS IN
THE NRN PLAINS IS ALSO QUITE DRY /AREA PWATS ARE UNDER 0.10 INCH AND
THE 00Z H85 AND H7 DEWPT DEPRESSIONS AT BISMARCK WERE 19C AND 30C
RESPECTIVELY/...THERE IS AN ABSENCE OF PCPN ACCOMPANYING THIS
DISTURBANCE.
MAIN FCST CONCERNS IN THE SHORT TERM WL FOCUS ON MAX TEMPS TODAY AND
IMPACT TNGT OF SHRTWV NOW MOVING THRU THE NRN PLAINS.
TODAY...SHRTWV RDG AXIS NOW IN MN IS PROGGED TO PASS THRU THE CWA
THIS AFTN. ACCOMPANYING AREA OF H85-5 RH UNDER 20 PCT WL RESULT IN
SUNSHINE FILTERED AT TIMES BY SOME HI CLDS STREAMING INTO THE AREA
IN ADVANCE OF SHRTWV THAT IS FCST TO REACH NW MN BY 00Z SUN. AS H85
TEMPS REBOUND TO ARND -14C IN THE SW FLOW ARND SFC HI PRES SHIFTING
TOWARD THE MID ATLANTIC STATES...EXPECT MAX TEMPS TO TOP OUT A
COUPLE OF DEGREES HIER THAN OBSVD YDAY...PERHAPS UP TO 25 IN THE
DOWNSLOPE AREAS NEAR LK SUP BTWN MARQUETTE AND BARAGA. THE LOWEST
TEMPS IN THE TEENS ARE LIKELY DOWNWIND OF THE ICE COVERED NRN BAY OF
GREEN BAY/LK MI.
TNGT...SHRTWV OVER NW MN IS PROGGED TO SHIFT E ACROSS NRN LK SUP AND
INTO ONTARIO JUST E OF THE LK BY 12Z ON SUN. SOME DPVA/MODEST DEEP
LYR QVECTOR CNVGC IS FCST TO INFLUENCE UPR MI AHEAD OF THE SHRTWV.
BUT MODEST MSTR INFLOW/ISENTROPIC ASCENT INTO ANTECEDENT BONE DRY
AIRMASS WL GREATLY RESTRICT POPS. IN FACT...MOST OF THE MODELS
INDICATE A MAINLY DRY OVERNGT AND GENERATE ONLY PATCHY LIGHT PCPN.
SEEMS THE BEST CHC FOR PCPN WL BE OVER LK SUP AND PERHAPS DOWNWIND
OF LK MI FM MANISTIQUE TO NEWBERRY. WL RETAIN MENTION OF SCHC
POPS...MAINLY OVERNGT. LO TEMPS TNGT COULD BE TRICKY WITH LINGERING
DRY AIR IN PLACE BEFORE THICKER CLDS ARRIVE. TENDED TO GO HIER WITH
MIN TEMPS IN THE DOWNSLOPE AREAS NEAR LK SUP IN PREVAILING SSW FLOW.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 351 AM EST SAT FEB 28 2015
MAIN ISSUE THIS FORECAST PERIOD WILL BE WIDESPREAD LIGHT TO MODERATE
SNOWFALL POTENTIAL TUESDAY INTO TUESDAY EVENING WITH CONTINUED
MODERATING TEMPERATURES.
SUNDAY THROUGH MONDAY...A SURFACE TROUGH/WEAK COLD FRONT WILL
CONTINUE TO SHIFT EASTWARD AND PASS THROUGH THE CENTRAL AND EASTERN
PORTIONS OF THE UPPER PENINSULA THROUGH THE DAY SUNDAY. MOISTURE
WILL BE SHALLOW AND FAIRLY LIMITED ALONG THE FRONT WITH CONTINUED
WEAK FORCING. THIS WILL TOUCH OFF VERY LIGHT SNOW THROUGH THE DAY
SUNDAY. BEHIND THE FRONT...AN UPPER LEVEL 500MB TROUGH IS POISED TO
SWING ACROSS THE U.P. SUNDAY NIGHT. AS THIS HAPPENS...ENOUGH
MOISTURE WILL REMAIN IN PLACE WITH MINIMAL ADDITIONAL MOISTURE ADDED
FROM THE VERY ICE COVERED LAKE SUPERIOR TO ALLOW A CHANCE OF LAKE
EFFECT SNOW SHOWERS TO DEVELOP FOR WEST TO NORTHWEST WIND FAVORED
LOCATIONS. 850MB TEMPERATURES WILL DROP TO AROUND -15C TO -20C
ALLOWING FOR SUFFICIENT DELTA T VALUES FOR LAKE EFFECT WITH THE
TROUGH AXIS SLIDING ACROSS...BUT LAKE EFFECT INTENSITY/COVERAGE WILL
BE LIMITED TO AREAS THAT BREAKS IN THE ICE COVER OCCUR. THIS IS
ESPECIALLY TRUE NOW THAT THE ICE EXTENT ON LAKE SUPERIOR IS AT 95.55
COVERED...WHICH IS THE MAX FOR THE SEASON TO THIS POINT. ANY LAKE
EFFECT THAT IS ABLE TO DEVELOP SUNDAY NIGHT WILL BE SHORT LIVED AS
MUCH DRIER AIR AND HIGH PRESSURE AT THE SURFACE AND RIDGING ALOFT
PUSH INTO THE UPPER GREAT LAKES REGION DURING THE DAY MONDAY. THIS
WILL ALL MOST AREAS TO SEE MAINLY SUNNY SKIES DURING THE DAY MONDAY
WITH HIGHS IN THE 20S FOR MOST AREAS. THIS IS STILL BE AROUND 5 TO
10 DEGREES BELOW NORMAL...BUT IT WILL DEFINITELY BE WARMER THAN THE
LAST SEVERAL WEEKS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE SURFACE HIGH PRESSURE
SYSTEM WILL BE SHORT LIVED AND WILL SHIFT TO THE LOWER GREAT LAKES
THROUGH MONDAY EVENING...THEN TO THE EASTERN SEABOARD LATE MONDAY
NIGHT. THIS WILL ALLOW A MORE MOIST...SLIGHTLY WARMER...SOUTHERLY
FLOW TO DEVELOP ON THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A
SURFACE LOW PRESSURE SYSTEM IS PROGGED TO DEVELOP ALONG A SHORTWAVE
OVER THE FOUR CORNERS REGION OF THE CONUS. ANOTHER STRONGER WAVE OF
ENERGY IS PROGGED TO PUSH ACROSS CENTRAL CANADA AND WORK TOWARD THE
JAMES BAY AREA. MODEL DIFFERENCES CONTINUE WITH THE PHASING OF THE
TWO SYSTEMS. THE 18Z/27 00Z/28 GFS CONTINUES TO BE MORE PROGRESSIVE
WITH BOTH SYSTEMS AND THE PHASING OF THE SYSTEMS.
ADDITIONALLY...THE GFS INTENSIFIES THE SOUTHERN SYSTEM MORE
AGGRESSIVELY THAN THE LAST TWO RUNS OF THE EC. EVEN THOUGH IT IS
MORE PROGRESSIVE OVERALL...THE LATEST RUNS OF THE GFS ARE SLOWER
WITH BRINGING PRECIP INTO THE AREA THAN IT HAS BEEN OVER THE
PREVIOUS DAYS RUNS...MORE IN LINE WITH THE EC. THE EC 12/27 00Z/28
CONTINUES TO BE MUCH SLOWER WITH THE PHASING...KEEPING THE
PRECIPITATION OUT OF THE AREA UNTIL VERY LATE MONDAY NIGHT INTO
TUESDAY MORNING. THE OVERALL IMPACT...AS FAR AS SNOWFALL
AMOUNTS...WILL LARGELY DEPEND ON HOW AND WHEN THESE SYSTEM MERGE.
EITHER WAY...IT DOES LOOK LIKE MOST OF THE U.P. WILL SEE WIDESPREAD
SNOWFALL THROUGH THE DAY TUESDAY INTO TUESDAY EVENING...WITH THE
HEAVIER SNOWFALL TOTALS EXPECTED ACROSS SOUTH CENTRAL AND THE EAST
HALF OF THE U.P. MODELS AGREE WITH QPF BEING PAINTED OUT ACROSS
THESE AREAS TO THE POINT THAT LIKELY POPS ARE IN ORDER ESPECIALLY
TUESDAY AFTERNOON INTO TUESDAY EVENING
...AGAIN THE AMOUNTS ARE THE MAIN QUESTION AT THIS POINT WITH THE
GFS PLACING AROUND A HALF INCH QPF ACROSS THE AREA AND THE EC
PAINTING AROUND A QUARTER INCH. THIS WOULD GIVE SNOWFALL TOTALS OF
AROUND 1 TO 3 INCHES OVER THE WEST HALF WITH AROUND 2 TO 5 INCHES
OVER THE EAST HALF...AGAIN THESE ARE PRELIMINARY ESTIMATES AND WILL
BE ADJUSTED AS MODELS BEGIN TO COME INTO BETTER AGREEMENT WITH
BETTER SAMPLING OVER TIME. THE FORTUNATE ASPECT OF THIS SYSTEM IS
THAT IT IS FAIRLY QUICK MOVING...WHICH SHOULD HELP TO KEEP SNOWFALL
TOTALS IN CHECK...BUT IT COULD BE SOMEWHAT OF A HASSLE AS THE
HEAVIER SNOW WOULD FALL DURING THE TUESDAY AFTERNOON/EVENING COMMUTE.
WEDNESDAY THROUGH THE REMAINING EXTENDED...BOTH THE EC AND GFS AGREE
ON AN UPPER LEVEL TROUGH AXIS ALONG WITH CONTINUED MOISTURE ACROSS
THE AREA DURING THIS TIME PERIOD. THE COLDER TEMPERATURES ALOFT
ALONG WITH ANY ADDITIONAL MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR
LAKE EFFECT SNOW CHANCES ACROSS PORTIONS OF THE U.P...ESPECIALLY
THROUGH THURSDAY. AGAIN...THE EXACT LOCATION ALONG WITH INTENSITY
WILL BE LARGELY TIED TO ANY BREAKS IN THE ICE COVER ON LAKE
SUPERIOR. THE FAVORED LOCATIONS BASED SOLELY ON WIND WOULD BE FOR
THE WEST TO WEST NORTHWEST WIND FAVORED SNOW BELTS WITH A SURFACE
HIGH PRESSURE SYSTEM PASSING TO THE SOUTH OF THE REGION.
GENERALLY...ANY LAKE EFFECT SNOW SHOULD REMAIN FAIRLY LIGHT...BUT
THIS WILL DEPEND ON ANY BREAKS IN THE ICE ON LAKE SUPERIOR. THURSDAY
NIGHT...THE SURFACE HIGH WILL SHIFT TO THE EAST OF THE AREA AS A
SURFACE TROUGH APPROACHES THE U.P. FROM THE WEST. THIS WILL
EFFECTIVELY TURN WINDS SOUTH TO SOUTHWESTERLY...ENDING ANY LAKE
EFFECT SNOW CHANCES ACROSS THE U.P.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1244 PM EST SAT FEB 28 2015
A DRY SW FLOW AROUND HIGH PRES SHIFTING TOWARD THE MID ATLANTIC
STATES WILL BRING VFR CONDITIONS TO KIWD/KCMX/KSAW THRU THIS FCST
PERIOD. SOME THICKER CLOUDS WILL ARRIVE TONIGHT IN ADVANCE OF AN
APPROACHING LOW PRES TROF...BUT THE LOW-LEVELS SHOULD REMAIN DRY
ENOUGH TO MAINTAIN VFR CIGS EVEN IF THERE IS SOME VERY LIGHT SNOW OR
FLURRIES. GUSTIER W WINDS WILL DEVELOP LATE SUN MORNING/EARLY AFTN
AT KCMX AFTER SFC TROF PASSAGE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 AM EST SAT FEB 28 2015
NO GALES EXPECTED INTO NEXT WEEK...WITH WINDS NO HIGHER THAN 20 TO
25 KTS. LAKE SUPERIOR REMAINS MOSTLY ICE COVERED AND THOUGH SHIFTING
WINDS WITH A SERIES OF TROUGH PASSAGES MAY CAUSE HOLES TO OPEN IN
THE ICE FROM TIME TO TIME...A CONTINUED DOMINANCE OF ARCTIC AIR WILL
MAINTAIN AN OVERALL EXTENSIVE ICE COVER.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
311 PM CST Sat Feb 28 2015
.SHORT TERM...(This Evening through Sunday Night)
Issued at 307 PM CST SAT FEB 28 2015
A large area of snow has blanketed all of the Missouri Ozarks and
extreme southeastern Kansas as of mid afternoon. Visibilities were
pretty much below one mile over all areas...with occasional
observations indicating quarter mile visibilities with heavy snow.
Snowfall accumulations up through 3 PM have been in the 1-3"
range. We suspect that some locations across extreme southeastern
Kansas and west-central Missouri may be in that 3-4" range.
As we head into late this afternoon and this evening, short term
models are beginning to change their tune a bit. Both the RAP
and the HRRR have somewhat backed off on a secondary band of snow
developing along the I-44 corridor this evening. Even the 18Z NAM
has trended this way. Instead, models gradually take the large
area of moderate to occasionally heavy snow to the east and
northeast with the back edge of the heavier snow moving east
across the Ozarks this evening. This would tend to make sense as
low level isentropic upglide and a weak upper level jet coupling
structure shift towards the Mid Mississippi Valley. We will still
have to watch for some banding of snow as models do indicate some
slugs of increased 700 mb frontogenesis...especially along and
north of the I-44 corridor.
As we head into later tonight, the main area of snow will have
shifted east of the area. Pockets of light snow and flurries
will be left in its wake. While snow intensity will be on the
downward trend this evening (again from west to east), it will
tend to accumulate more efficiently given that the sun will have
set. Models are also indicating perhaps some loss of cloud ice
later tonight. Additionally, models still bring a warm nose into
southern Missouri by late tonight. Thus, we are continuing a
mention of either light freezing rain or freezing drizzle.
This trend will then continue into Sunday morning with pockets of
light snow and drizzle/freezing drizzle. We have slowed the
progress of the surface freezing line to the north by a few
hours...which does keep the door open a bit longer for minor ice
accumulation. One thing we will have to watch very closely is what
will be a good setup for a banded snow event from late tonight
into Sunday morning up towards I-70. Models continue to indicate
strong 700 mb frontogenesis and available negative EPV becoming
juxtaposed with a favorable upper level jet streak. If this
materializes, it could put down a narrow swath of additional
heavier snowfall. While this could glance our central Missouri
counties, confidence is higher that it will remain just north of
the area. Once we get into Sunday afternoon and especially Sunday
night, the primary precipitation will be shifting east and
southeast of the region.
As for storm total ice and snow amounts, we have not changed much.
Any ice accumulations are still expected to remain at or below
five-hundredths of an inch. 1-3" of snow is expected across
south-central Missouri. Accumulations near and north of the I-44
corridor will be in the 3-6" range. We still think a few isolated
reports of around 7" will be possible. Given that any 6-7" amounts
are expected to be isolated (if they occur at all), the current
Winter Weather Advisory will be left intact.
.LONG TERM...(Monday through Saturday)
Issued at 307 PM CST SAT FEB 28 2015
By Monday morning, precipitation should push south of the region,
at least temporarily, as high pressure noses south from the
Dakotas. Highs on Monday look to reach the upper 30s in most
locations.
Precipitation will then return to the area Monday night into
Tuesday, though at this point it appears that temperatures
should be above freezing by the time rain begins to fall Monday
night. Rain will continue through much of the day Tuesday, as low
pressure at the surface deepens and lifts north across Kansas and
northern Missouri. Breezy southwest winds during the day Tuesday
will help temperatures warm into the low to mid 50s. Will continue
to include a mention of thunder in the forecast for Tuesday, with
guidance suggesting a couple hundred J/KG of CAPE making its way
into the CWA.
A strong cold front will then sweep across the area Tuesday
afternoon and evening, with colder air quickly advecting into
the area Tuesday night. We will need to carefully watch the
potential for post frontal snow Tuesday night and Wednesday, as
lift from a secondary trough axis may be enough to result in areas
of snow on Wednesday. As it stands right now, the highest snow
potential for Wednesday looks to be south of I-44, though this
will be highly dependent on the eventual location of the front.
The upper level flow will then flatten out a bit, with
southwesterly flow developing at the surface for the end of the
week into next weekend. This is suggestive of warmer temperatures
for the end of the week, with highs perhaps (finally) approaching
climatological averages by this time next weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1149 AM CST SAT FEB 28 2015
IFR and LIFR conditions will continue this afternoon and evening
across the region as moderate to at times heavy snow affect the
terminals. Prevailing conditions will likely be just above airport
minimums at SGF and JLN, but dips to or below mins are likely
if/when bands of the heaviest snow move overhead.
Snow intensity should decrease somewhat later tonight, though cigs
will remain low. A south to north transition to a wintry mix of
snow, rain and freezing rain is expected at some point late
tonight, with an eventual changeover to just rain around mid day
tomorrow as temperatures rise above freezing. While this
transition has been indicated in the TAFs, confidence in exact
timing is very low.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...WINTER WEATHER ADVISORY until Noon CST Sunday FOR MOZ055>058-
066>071-077>083-088>098-101>106.
KS...WINTER WEATHER ADVISORY until Noon CST Sunday FOR KSZ073-097-101.
&&
$$
SHORT TERM...Schaumann
LONG TERM...Boxell
AVIATION...Boxell
AREA FORECAST DISCUSSION
NWS HASTINGS NE
335 PM CST SAT FEB 28 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 333 PM CST SAT FEB 28 2015
ZONAL FLOW REMAINS IN PLACE ACROSS THE REGION THIS
AFTERNOON...WITH SATELLITE IMAGERY SHOWING THE SHORTWAVE
DISTURBANCE WHICH BROUGHT ACCUMULATING SNOW TO SRN PORTIONS OF THE
CWA CONTINUING TO SLIDE EAST THROUGH THE PLAINS. RADAR TRENDS SHOW
THE BRUNT OF THE SNOWFALL HAS SHIFTED OFF INTO ERN KS/SERN
NEB...WITH JUST SOME LIGHT SNOW/FLURRIES LINGERING ACROSS OUR ERN
COUNTIES. REPORTS RECEIVED FROM PORTIONS OF NC KS HAD TOTALS
TOPPING OUT AROUND 1.5 INCHES. AT THE SFC...THE CWA REMAINS IN
BETWEEN HIGH PRESSURE NOW CENTERED OVER THE NERN CONUS AND LOW
PRESSURE OVER THE HIGH PLAINS...KEEPING THOSE SRLY WINDS IN PLACE.
TEMPS THIS AFTERNOON GOING PRETTY MUCH AS EXPECTED...WITH 3 PM
TEMPS RUNNING THE WHOLE RANGE OF 20S.
WITH THE FIRST WAVE SHIFTING EAST THROUGH THE AREA THIS AFTERNOON
AND THE CWA SITTING IN A BIT OF A LULL...DECIDED TO KEEP THE
EVENING HOURS DRY. DO HAVE POPS RETURNING POST 06Z
TONIGHT...WITH THE POTENTIAL FOR A BIT MORE SNOW AS ANOTHER WEAKER
SHORTWAVE DISTURBANCE AND THE ENTRANCE REGION OF A 140ISH KT UPPER
LEVEL JET STREAK MOVES IN. EVEN THIS CLOSE TO THE POTENTIAL
PRECIP...MODELS DO NO AGREE WITH WHAT THE CWA WILL SEE. 4KM AND
SREF SHOW CHANCES AFFECTING AREAS SOUTH OF I-80...WHILE OTHERS
LIKE THE RAP AND ECMWF SHOW BASICALLY NOTHING. INHERITED FORECAST
INCLUDED SOME CHANCE POPS...AND ONLY MADE MINOR ADJUSTMENTS TO
THOSE. SHOULD SNOW DEVELOP/MOVE INTO THE CWA...ONLY EXPECTING AN
ADDITION FEW TENTHS OF A INCH OF ACCUMULATION.
HAVE LINGERING LOW POPS DURING THE MORNING HOURS TOMORROW...WITH
DRY CONDITIONS FOR THE AFTERNOON. WHILE PLENTY OF CLOUD COVER IS
EXPECTED TONIGHT...WITH TIME TOMORROW SKY COVER SHOULD DIMINISH.
WITH THIS DISTURBANCE MOVING THROUGH LATE TONIGHT/EARLY
TOMORROW...EXPECTING A SWITCH IN WINDS TO THE NORTHWEST
ACCOMPANYING A FRONTAL BOUNDARY. DID BUMP UP HIGHS A FEW
DEGREES...AS MODELS SHOW SLIGHTLY WARMING TEMPS ALOFT WORKING IN
THROUGH THE DAY WITH THOSE NWRLY WINDS /ALTHOUGH THEY ARE ONLY
AROUND 10 MPH/. HIGHS CURRENTLY FORECAST TO REACH INTO THE MID
30S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 333 PM CST SAT FEB 28 2015
MAIN CHALLENGE WILL BE DETERMINING CHANCES OF PRECIPITATION LATE
SUNDAY NIGHT THROUGH TUESDAY NIGHT AND PRECIPITATION TYPE LATE
MONDAY NIGHT INTO TUESDAY MORNING.
NUMERICAL MODELS AGREE QUITE WELL WITH SYNOPTIC FEATURES. A DEEP
TROUGH IN THE WEST WILL CONTINUE TO APPROACH THE PLAINS FOR THE
FIRST PART OF THE EXTENDED FORECAST. WHILE IN SOUTHWEST
FLOW...THERE COULD BE GENERALLY LOW CHANCES OF PRECIPITATION AS
LOW AMPLITUDE WAVES ARE KICKED OUT OF THE BASE OF THE TROUGH. NOT
UNTIL THE TROUGH MAKES ITS WAY INTO AND EAST OF THE GREAT PLAINS
WILL BE SHUT OFF THE POTENTIAL FOR PRECIPITATION. THE SPECIFICS
AND TIMING ARE FAR FROM AGREED UPON BETWEEN NUMERICAL MODELS.
GENERALLY NEED TO GO WITH LOW CHANCES FOR MOST OF THE FIRST HALF
OF THE LONG TERM FORECAST TO ESSENTIALLY COVER OUR BASES.
CONFIDENCE IS RATHER LOW REGARDING TIMING OF ANY LULLS ALONG WITH
PRECIPITATION AS BOUTS OF SNOW MAY BE RELATIVELY SHORT LIVED. THE
NAM INDICATES ISENTROPIC LIFT FOR MONDAY...GIVING US A SHOT AT
SOME RAIN/SNOW. BOTH THE NAM AND GFS INDICATE CONTINUED ISENTROPIC
LIFT TOWARD LATE MONDAY NIGHT...BUT THE NAM INDICATES A LOSS OF
SATURATION IN THE DENDRITIC GROWTH ZONE...SO THERE COULD BE A
SHORT PERIOD OF FREEZING DRIZZLE BEFORE ISENTROPIC DOWNGLIDE
ENSUES. STILL...THERE IS SO MUCH INCONSISTENCY AND LACK OF
AGREEMENT...I CONTINUE TO BE QUITE SKEPTICAL OF THIS...SO I WILL
PROBABLY CONTINUE TO LEAVE THIS OUT OF THE FORECAST FOR NOW AND
STICK WITH SNOW.
ANOTHER THING TO KEEP AN EYE ON IS WIND SPEED IN COMBINATION WITH
SNOW FALLING FOR TUESDAY BEHIND A COLD FRONT. NORTHWEST WINDS AT
30 MPH GUSTING TO 40 MPH ARE EXPECTED...AND WITH UP TO 2 INCHES
OF SNOWFALL...WE COULD EASILY HAVE REDUCED VISIBILITY.
WIND CHILLS ON WEDNESDAY MORNING DID NOT DIP QUITE LOW ENOUGH TO
MENTION IN THE HWO.
ONCE WE GET THE TROUGH EAST OF US...WE WILL BE MORE CONFIDENTLY
DRY AND EVENTUALLY WARM UP TOWARD NEXT WEEKEND...MAYBE EVEN NEAR
OR ABOVE NORMAL FOR A CHANGE AS A RIDGE IN THE WEST NUDGES EAST.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1125 AM CST SAT FEB 28 2015
MAIN CONCERN FOR THIS TAF LIES WITH THE BEGINNING AND END FEW
HOURS. A SHORTWAVE DISTURBANCE CONTINUES TO BRING SNOW TO SRN
PORTIONS OF THE CWA AT MIDDAY...WITH BOTH TERMINALS BARELY OUTSIDE
THE NRN FRINGE OF THE PRECIP. CANT COMPLETELY RULE OUT EITHER
GETTING CLIPPED BY SOME -SN SO DECIDED TO INSERT A TEMPO GROUP
FOR A FEW HOURS. ALSO MENTIONED MVFR CONDITIONS...THOUGH
CONFIDENCE IN HOW LONG THOSE DO/DO NOT STICK AROUND THIS AFTERNOON
IS LOW. HAVE ANOTHER MENTION OF MVFR CONDITIONS TOWARD THE END OF
THE TAF PERIOD...AS A COLD FRONT PUSHES ITS WAY THROUGH THE AREA.
PRIOR TO THE FRONT...WINDS WILL REMAIN SRLY AT BOTH
TERMINALS...WITH NORTHWEST WINDS FILLING IN BEHIND THE FRONT
AROUND MID MORNING TOMORROW.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADP
LONG TERM...HEINLEIN
AVIATION...ADP
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1227 PM CST SAT FEB 28 2015
.UPDATE...
ISSUED AT 1225 PM CST SAT FEB 28 2015
THE FORECAST IS IN GOOD SHAPE...WITH NO CHANGES NEEDED.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 315 AM CST SAT FEB 28 2015
FORECAST CHALLENGES CONCERN TEMPERATURES AND LOW END SNOW CHANCES.
MAIN MODEL DIFFERENCES WILL BE -SN POTENTIAL WITH WEAK WAVE
PASSAGES AND WILL USE A BLEND.
SEVERAL WEAK WAVES WILL ROTATE THROUGH BASE OF NORTHERN STREAM MID
LEVEL TROUGH THIS WEEKEND. FIRST OF THESE FEATURES AND ASSOCIATED
SURFACE TROUGH MOVING INTO WESTERN ND WILL PROPAGATE EAST ACROSS
FA LATER TODAY AND TONIGHT. ECMWF CONTINUES TO BE WEAKEST WITH -SN
POTENTIAL. AT THIS POINT IT LOOKS TO BE THE ODD MODEL OUT AS
GFS/GEM/NAM ALL SHOWING BETTER SNOW POTENTIAL ALBEIT LIGHT MAINLY
THIS EVENING. RUC ALSO DEVELOPING -SN FROM VALLEY EASTWARD LATE
THIS AFTERNOON INTO THE EVENING. WITH RUCS SPOTTY NATURE OF
POSSIBLE -SN HESITANT TO RAISE POPS TOO FAR AND KEPT WITHIN CHANCE
RANGE. LOW LEVEL WARM ADVECTION WILL CONTINUE AHEAD OF TROUGH AND
WILL BE STARTING OUT ABOUT 10 DEGREES WARMER THAN YESTERDAY.
SATELLITE IMAGERY/SFC OBS INDICATING BKN SC DECK ACROSS CENTRAL-
WESTERN ND WHICH SHOULD MOVE IN TODAY WHICH MAY HAVE AN IMPACT ON
DEGREE OF WARMING. FOR THIS WAS CONSERVATIVE ON MAXIMUM
TEMPERATURES. ANY -SN THIS EVENING OVER NW MN SHOULD EXIT FA TO
THE EAST AFT MIDNIGHT. OVERALL LOOKING A HALF INCH OR SO OF
POTENTIAL ACCUMULATION. CLOUDS WILL ALSO HAVE A BEARING ON MINIMUM
TEMPERATURES TONIGHT.
A WEAKER WAVE WILL AFFECT FA ON SUNDAY. SURFACE FEATURES ALSO
WEAKER SO LIKELY LOOKING AT MAINLY FLURRIES BUT DID INTRODUCE SOME
LOW POPS OVER NW MN LATE IN THE AFTERNOON. FOLLOWED PERSISTENCE
WITH TEMPERATURES AS CLOUDS AND HOW COLD WE START OUT IN THE MORNING
WILL IMPACT MAX TEMPERATURES.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 AM CST SAT FEB 28 2015
HIGH PRESSURE WILL SHIFT ACROSS CENTRAL PLAINS SUNDAY NIGHT. WITH
HIGH CENTER TO OUR SOUTH W-SW SURFACE FLOW AND WARM ADVECTION WILL
LIMIT TEMPERATURE DROP AND SHOULD SEE MINS A FEW DEGREES EITHER
SIDE OF ZERO.
BRISK SOUTHERLY FLOW AND CONTINUED WARM ADVECTION MONDAY SHOULD
ALLOW TEMPERATURES TO FINALLY APPROACH SEASONAL AVERAGES.
MAINTAINED LOW POPS MONDAY NIGHT WITH APPROACH OF NEXT WAVE AND
COLD FRONT ALTHOUGH MODELS NOT IN VERY GOOD AGREEMENT. BASED ON
TIMING OF COLD FRONT BOUNDARY LOOKS TO BE THROUGH ALL BUT THE FAR
SE BY MORNING. THIS COULD SET UP RESPECTABLE TEMPERATURE CONTRAST
ACROSS THE FA WITH COLDEST MINIMUMS ACROSS THE NW DEEPER IN THE
COLDER AIR.
A BREEZY TO WINDY EXTENDED PERIOD LOOKS TO BE SHAPING UP AS ARCTIC
BOUNDARY PUSHES THROUGH THE FORECAST AREA EARLY TUESDAY SWINGING
WINDS FROM SW TO NNW. CAA BEHIND BOUNDARY WILL MAKE WEDNESDAY THE
COLDEST OF THE BUNCH WITH AREA WIDE HIGHS ONLY IN THE POSITIVE
SINGLE INTEGERS. GFS/ECMWF ARE CLOSE WITH 850 MB TEMPS PEGGING A
CORE OF -20 TO NEAR -30C INTO AND THROUGH THE NORTHERN VALLEY. ASIDE
FROM A PERIOD OF LIGHT SNOW/SNOW SHOWERS FOR WC MN TUE AFTN THE
ENTIRETY OF THE EXTENDED IS ESSENTIALLY POP FREE. UPPER FLOW BECOMES
MORE ZONAL THUR INTO FRI AND AS SURFACE HIGH DRIFTS SOUTH AND
SOUTHEAST EXPECT THERMAL RECOVERY TO NEAR AVERAGE VALUES BY
FRI...MAXES FROM THE UPPER 20S TO LOW 30S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1225 PM CST SAT FEB 28 2015
MAINLY VFR CONDITIONS ARE EXPECTED THIS AFTERNOON THRU TONIGHT AT
THE TAF SITES. A WEAK COLD FRONT WILL CROSS THE AREA LATER IN THE
PERIOD CAUSING THE WINDS TO SHIFT TO A WEST TO NORTHWESTERLY
DIRECTION. SOME MVFR CIGS CAN BE EXPECTED NEAR THE END OF THE
PERIOD...WITH SOME LIGHT FLURRIES MIXED IN.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...VOELKER
LONG TERM...WJB/VOELKER
AVIATION...DK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1012 AM CST SAT FEB 28 2015
.UPDATE...
ISSUED AT 1010 AM CST SAT FEB 28 2015
WE WILL INCREASE WINDS A BIT ALONG AND EAST OF THE VALLEY...WITH
ABOUT 30-35KT NEAR 925MB THROUGH 18Z. WINDS SHOULD SLOWLY SUBSIDE
BY LATE AFTERNOON. OTHERWISE...NO CHANGES NEEDED THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 315 AM CST SAT FEB 28 2015
FORECAST CHALLENGES CONCERN TEMPERATURES AND LOW END SNOW CHANCES.
MAIN MODEL DIFFERENCES WILL BE -SN POTENTIAL WITH WEAK WAVE
PASSAGES AND WILL USE A BLEND.
SEVERAL WEAK WAVES WILL ROTATE THROUGH BASE OF NORTHERN STREAM MID
LEVEL TROUGH THIS WEEKEND. FIRST OF THESE FEATURES AND ASSOCIATED
SURFACE TROUGH MOVING INTO WESTERN ND WILL PROPAGATE EAST ACROSS
FA LATER TODAY AND TONIGHT. ECMWF CONTINUES TO BE WEAKEST WITH -SN
POTENTIAL. AT THIS POINT IT LOOKS TO BE THE ODD MODEL OUT AS
GFS/GEM/NAM ALL SHOWING BETTER SNOW POTENTIAL ALBEIT LIGHT MAINLY
THIS EVENING. RUC ALSO DEVELOPING -SN FROM VALLEY EASTWARD LATE
THIS AFTERNOON INTO THE EVENING. WITH RUCS SPOTTY NATURE OF
POSSIBLE -SN HESITANT TO RAISE POPS TOO FAR AND KEPT WITHIN CHANCE
RANGE. LOW LEVEL WARM ADVECTION WILL CONTINUE AHEAD OF TROUGH AND
WILL BE STARTING OUT ABOUT 10 DEGREES WARMER THAN YESTERDAY.
SATELLITE IMAGERY/SFC OBS INDICATING BKN SC DECK ACROSS CENTRAL-
WESTERN ND WHICH SHOULD MOVE IN TODAY WHICH MAY HAVE AN IMPACT ON
DEGREE OF WARMING. FOR THIS WAS CONSERVATIVE ON MAXIMUM
TEMPERATURES. ANY -SN THIS EVENING OVER NW MN SHOULD EXIT FA TO
THE EAST AFT MIDNIGHT. OVERALL LOOKING A HALF INCH OR SO OF
POTENTIAL ACCUMULATION. CLOUDS WILL ALSO HAVE A BEARING ON MINIMUM
TEMPERATURES TONIGHT.
A WEAKER WAVE WILL AFFECT FA ON SUNDAY. SURFACE FEATURES ALSO
WEAKER SO LIKELY LOOKING AT MAINLY FLURRIES BUT DID INTRODUCE SOME
LOW POPS OVER NW MN LATE IN THE AFTERNOON. FOLLOWED PERSISTENCE
WITH TEMPERATURES AS CLOUDS AND HOW COLD WE START OUT IN THE MORNING
WILL IMPACT MAX TEMPERATURES.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 AM CST SAT FEB 28 2015
HIGH PRESSURE WILL SHIFT ACROSS CENTRAL PLAINS SUNDAY NIGHT. WITH
HIGH CENTER TO OUR SOUTH W-SW SURFACE FLOW AND WARM ADVECTION WILL
LIMIT TEMPERATURE DROP AND SHOULD SEE MINS A FEW DEGREES EITHER
SIDE OF ZERO.
BRISK SOUTHERLY FLOW AND CONTINUED WARM ADVECTION MONDAY SHOULD
ALLOW TEMPERATURES TO FINALLY APPROACH SEASONAL AVERAGES.
MAINTAINED LOW POPS MONDAY NIGHT WITH APPROACH OF NEXT WAVE AND
COLD FRONT ALTHOUGH MODELS NOT IN VERY GOOD AGREEMENT. BASED ON
TIMING OF COLD FRONT BOUNDARY LOOKS TO BE THROUGH ALL BUT THE FAR
SE BY MORNING. THIS COULD SET UP RESPECTABLE TEMPERATURE CONTRAST
ACROSS THE FA WITH COLDEST MINIMUMS ACROSS THE NW DEEPER IN THE
COLDER AIR.
A BREEZY TO WINDY EXTENDED PERIOD LOOKS TO BE SHAPING UP AS ARCTIC
BOUNDARY PUSHES THROUGH THE FORECAST AREA EARLY TUESDAY SWINGING
WINDS FROM SW TO NNW. CAA BEHIND BOUNDARY WILL MAKE WEDNESDAY THE
COLDEST OF THE BUNCH WITH AREA WIDE HIGHS ONLY IN THE POSITIVE
SINGLE INTEGERS. GFS/ECMWF ARE CLOSE WITH 850 MB TEMPS PEGGING A
CORE OF -20 TO NEAR -30C INTO AND THROUGH THE NORTHERN VALLEY. ASIDE
FROM A PERIOD OF LIGHT SNOW/SNOW SHOWERS FOR WC MN TUE AFTN THE
ENTIRETY OF THE EXTENDED IS ESSENTIALLY POP FREE. UPPER FLOW BECOMES
MORE ZONAL THUR INTO FRI AND AS SURFACE HIGH DRIFTS SOUTH AND
SOUTHEAST EXPECT THERMAL RECOVERY TO NEAR AVERAGE VALUES BY
FRI...MAXES FROM THE UPPER 20S TO LOW 30S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 658 AM CST SAT FEB 28 2015
OFF AND ON VFR CIGS EXPECTED ACROSS THE REGION TODAY AHEAD OF A
WEAK FRONTAL BOUNDARY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...VOELKER
LONG TERM...WJB/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS MEDFORD OR
854 AM PST SAT FEB 28 2015
.UPDATE...WHILE THE BULK OF PRECIPITATION HAS COME TO AN END,
SOME SHOWERS REMAIN, PARTICULARLY OVER THE EAST SIDE. SATELLITE
IMAGERY SHOWS AN AREA OF COOLER CLOUD TOPS SPREADING INTO THE EAST
SIDE AND UP AGAINST THE CASCADES FROM THE NORTHEAST, AND COMBINED
WITH UPSLOPE EFFECTS, MORE SNOW IS LIKELY TO BE PRODUCED ON THE
NORTH TO EAST FACING SLOPES. AMOUNTS SHOULD BE LIGHT, BUT
LOCALIZED AREAS COULD SEE AN ADDITIONAL INCH OF SNOW THROUGH THIS
MORNING AND EARLY AFTERNOON.
HAVE MADE SOME ADJUSTMENTS TO ACCOUNT FOR THESE FACTORS,
BASICALLY SPREADING SLIGHT TO CHANCE POPS FARTHER NORTH AND
DELAYING THE SOUTHERLY RETREAT THROUGH THE AFTERNOON. HAVE ALSO
ALLOWED THE WINTER WEATHER ADVISORY FOR THE CASCADES TO EXPIRE
THISMORNING, ALTHOUGH SOME ADDITIONAL SNOW IS POSSIBLE, AS
MENTIONED BEFORE, AMOUNTS SHOULD BE LIGHT. SEE THE PREVIOUS
DISCUSSION BELOW FOR MORE INFORMATION. -BPN
&&
.AVIATION...FOR THE 28/12Z TAF CYCLE...SHOWERS ARE DIMINISHING THIS
MORNING BUT WILL LINGER LONGEST EAST OF THE CASCADES. SKIES ARE VFR
AT THE COAST AND ARE FORECAST TO REMAIN VFR INTO SUNDAY MORNING.
ELSEWHERE, THERE IS A MIX OF IFR AND MVFR CIGS AND VSBYS WITH
ISOLATED SHOWERS AND SNOW SHOWERS. CONDITIONS WILL GRADUALLY IMPROVE
THIS MORNING INTO THIS AFTERNOON WITH VFR EXPECTED TO BE WIDESPREAD
DURING THE AFTERNOON AND CONTINUING INTO THIS EVENING. GUSTY
NORTHEAST LOW LEVEL WINDS WILL INCREASE INTO THIS EVENING WITH
SPEEDS OF 25 TO 40 KT EXPECTED TO BE COMMON ACROSS THE AREA. WINDS
WILL DIMINISH LATER IN THE EVENING THEN PATCHY WEST SIDE VALLEY IFR
IS EXPECTED TO DEVELOP AND PERSIST INTO SUNDAY MORNING. /DW
&&
.MARINE...UPDATED 4 AM PST, SATURDAY, 28 FEB, 2015...NORTHERLY WIND
WAVE DOMINATED SEAS WILL BUILD TO A PEAK THIS EVENING AS LOW
PRESSURE ALONG THE COAST MOVES SOUTH AND HIGH PRESSURE OFFSHORE
BUILDS TOWARD THE WATERS. WINDS WILL BE STRONGEST IN THE OUTER
WATERS SOUTH OF CAPE BLANCO. THE OFFSHORE HIGH AND COASTAL LOW WILL
PERSIST WITH SLIGHTLY WEAKER NORTHERLY WINDS ON SUNDAY. ANOTHER LOW
MOVING SOUTH WILL LIKELY BRING RAIN AND AN INCREASE OF WINDS SUNDAY
NIGHT INTO MONDAY. A THERMAL TROUGH PATTERN WILL FOLLOW WITH GUSTY
NORTH WINDS AND STEEP SEAS...MAINLY SOUTH OF CAPE BLANCO THROUGH THE
MIDDLE OF THE WEEK. WINDS ARE FORECAST TO DIMINISH AND BACK TO
SOUTHERLY ON THURSDAY THEN REMAIN WEAK INTO SATURDAY. /DW
&&
.PREV DISCUSSION... /ISSUED 306 AM PST SAT FEB 28 2015/
DISCUSSION...CURRENT WATER VAPOR IMAGE SHOWS THE UPPER TROUGH
MOVING SOUTH AND IS OVER THE FORECAST AREA. PLENTY OF SHOWERS ARE
AROUND AND SOME OF THOSE ARE IN THE LOWER LEVELS THAT THE RADAR
CANNOT PICK UP ON, ESPECIALLY EAST OF THE CASCADES BECAUSE IT`S
OVER SHOOTING THE LOW LEVEL MOISTURE. A LOOK AT THE CAMERAS AT
SISKIYOU SUMMIT SUGGEST ROADS THERE ARE SLICK WITH AN INCH OR LESS
OF SNOW. IT`S ALSO SNOWING ALONG DEAD INDIAN MEMORIAL SUMMIT WITH
ROADS SNOW COVERED THERE. SNOW HAS STOPPED FOR THE MOMENT AT
DIAMOND LAKE AND LAKE OF THE WOODS. COULD NOT RULE OUT ADDITIONAL
SNOW SHOWERS THIS MORNING, BUT WITH LITTLE OR NO ADDITIONAL
ACCUMULATION.
TEMPERATURES IN NORTHEAST OREGON...SOUTHEAST WASHINGTON AND
WESTERN IDAHO REMAIN RELATIVELY MILD AND HAVE NOT DROPPED MUCH
DURING THE OVERNIGHT HOURS. TEMPERATURES EAST OF THE CASCADES HAVE
BEEN SITTING AROUND FREEZING. THIS SHOULD REMAIN THE CASE INTO THE
MORNING HOURS AND WITH DAYTIME WARMING WHICH SHOULD LIMIT THE
AMOUNT OF ACCUMULATING SNOW. THE NAM CONTINUES TO SHOW UPSLOPE
FLOW EAST OF THE CASCADES AS HIGH PRESSURE BUILDS IN FROM THE
NORTH. ALSO THE HRRR RADAR REFLECTIVITY PICKS UP ON THIS FEATURE
WELL. THEREFORE EXPECT SNOW TO DEVELOP IN EASTERN KLAMATH AND LAKE
COUNTIES THIS MORNING, THEN DECREASE AND MOVING SOUTH IN THE
AFTERNOON. STILL COULD NOT RULE OUT 1-3 INCHES FOR THESE LOCATIONS
THROUGH THE MORNING HOURS.
AS THE UPPER TROUGH MOVES SOUTH THIS AFTERNOON, A DRY NORTHEAST
FLOW WILL SET UP AND WE`LL SEE PRECIPITATION QUICKLY ENDING FROM
NORTHWEST TO SOUTHEAST. PRECIPITATION COULD LINGER INTO THE
AFTERNOON FOR THE NORTH FACING SLOPES OF THE SISKIYOUS DUE TO
NORTHERLY UPSLOPE FLOW, BUT IT WILL BE LIGHT AND WITH WARMING
ROADS IT SHOULD NOT ACCUMULATE.
THE UPPER TROUGH/LOW WILL CONTINUE TO MOVE SOUTH TONIGHT AND RIDGE
WILL NUDGE INTO WESTERN OREGON. DRY WEATHER IS EXPECTED TONIGHT
WITH MOSTLY CLEAR SKIES AND COLDER TEMPERATURES. SUNDAY REMAINS
DRY WITH CLEAR SKIES AND MILDER TEMPERATURES IN THE AFTERNOON.
MODELS SHOW ANOTHER SHORTWAVE MOVING SOUTH ALONG THE NORTHWEST
COAST SUNDAY NIGHT INTO MONDAY. THE MODELS ARE IN SIMILAR AGREEMENT
SHOWING JUST ENOUGH OVER WATER TRAJECTORY FOR PRECIPITATION TO
SPREAD INTO WESTERN OREGON. THIS SHORTWAVE WILL BE A QUICK MOVER,
SO NOT EXPECTING A LOT OF QPF FROM THIS AND MOST OF IT WILL BE
ALONG AND WEST OF THE CASCADES.
DRY WEATHER RETURNS TUESDAY AND COULD VERY WELL LAST INTO NEXT
WEEKEND. THE GFS AND EC SHOW SIMILAR RESULTS WITH THE RIDGE AXIS
BUILDING OVER THE PAC NW BY THE MIDDLE OF THE WEEK AND REMAINING
THERE INTO NEXT WEEKEND. -PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 1 PM THIS AFTERNOON TO 4 AM
PST SUNDAY FOR PZZ350-356.
HAZARDOUS SEAS WARNING UNTIL 4 AM PST SUNDAY FOR
PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST MONDAY
FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST SUNDAY FOR PZZ370.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST MONDAY FOR PZZ376.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 10 PM PST THIS EVENING
FOR PZZ376.
$$
BPN/MAP/DW