Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/02/15
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
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 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...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 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
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...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 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 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 JACKSON KY
911 PM EST SUN MAR 1 2015
.UPDATE...
ISSUED AT 911 PM EST SUN MAR 1 2015
UPDATED FORECAST TO TOSS IN SOME FOG THROUGH THE OVERNIGHT HOURS
AS SOME LOCALLY DENSE FOG HAS DEVELOPED. WILL ALSO UPDATE THE ZFP
AND HWO TO INCLUDE A MENTION OF FOG. FREEZING RAIN THREAT APPEARS
TO BE MINIMAL AS BEST RETURNS WILL LIKELY OCCUR WELL AHEAD OF
AREAS WHERE TEMPERATURES ARE REACHING THE FREEZING MARK.
THUS...WILL LIMIT THE FORECAST TO JUST RAIN OR SNOW FOR THE
REMAINDER OF THE NIGHT. AGAIN...ANY SNOW WILL BE MINOR AND HAVE
VERY LITTLE IMPACT. IN FACT...LATEST OBS ARE HANGING UP MUCH
HIGHER THAN EXPECTED TO THIS POINT...WITH MID TO UPPER 30S STILL
BE REPORTED ACROSS THE NORTHERN PORTION OF THE AREA WITH LOW TO
MID 40S TO THE SOUTH.
UPDATE ISSUED AT 641 PM EST SUN MAR 1 2015
UPDATED TO REMOVE POPS THROUGH THE EVENING AS WE REMAIN DRY
SLOTTED. HOWEVER...THE COLD FRONT...CURRENTLY PUSHING SOUTH ACROSS
NORTHERN KENTUCKY WILL SLIP SOUTH LATER THIS EVENING AND
OVERNIGHT. AS THIS HAPPENS...A MID LEVEL WAVE WILL PUSH EAST WITH
MOISTURE RAPIDLY INCREASING ALONG THE FRONTAL ZONE. THIS WILL MEAN
INCREASING PRECIPITATION CHANCES INTO THE OVERNIGHT HOURS. AS THE
FRONT SLIPS SOUTH...PRECIPITATION WILL END FROM NORTH TO SOUTH
THROUGH THE OVERNIGHT HOURS. PRECIPITATION WILL LIKELY HOLD ON THE
LONGEST IN SOUTHEAST KENTUCKY. ADJUSTED THE POPS TO REFLECT THE
HIGHEST PRECIPITATION CHANCES (CATEGORICAL) IN SOUTHEAST
KENTUCKY...TRAILING OFF TO JUST CHANCE IN THE NORTH...WHERE THE
FRONT WILL PUSH THROUGH MUCH FASTER THIS EVENING. HRRR CONTINUES
TO SHOW A GOOD HANDLE ON PRECIPITATION COVERAGE THIS EVENING...SO
WILL CONTINUE TO FOLLOW IT FAIRLY CLOSELY WITH EXPECTED ARRIVAL OF
MORE WIDESPREAD PRECIPITATION OVERNIGHT. THE PATTERN WOULD SUGGEST
TEMPERATURES WILL HAVE A TOUGH TIME COOLING FAST ENOUGH TO ALLOW
FOR MUCH FREEZING RAIN AND WITH GROUND TEMPERATURES FAIRLY WARM
GOING INTO THINGS TONIGHT...NOT NEARLY AS CONCERNED ABOUT ICING
TONIGHT. HOWEVER...THE CONVECTIVE NATURE OF THE HRRR WOULD SUGGEST
SOME PRECIPITATION RATES COULD GET FAIRLY GOOD LATER
TONIGHT...PERHAPS ALLOWING A QUICK CHANGEOVER TO SNOW IN THE
HEAVIER SHOWERS. THIS WOULD SEEM REASONABLE AND WILL HAVE TO WATCH
FOR THIS AS THIS COULD PUT DOWN A QUICK COATING OF SNOW IN SOME
AREAS...LEADING TO SOME SLICK ROADS. AT THE SAME
TIME...TEMPERATURES ARE NOT EXPECTED TO FALL MUCH BELOW FREEZING
FOR MUCH OF THE AREA...SO ANY SNOW MAY NOT LAST ON ROADS GIVEN THE
WARMTH TODAY. THUS...IT MAY JUST BE A VERY SHORT TERM ISSUE TO
CONTEND WITH OVERNIGHT FOR THOSE DRIVING ACROSS EASTERN
KENTUCKY...ESPECIALLY SOUTHEAST KENTUCKY. WE MAY CONSIDER DOING A
SHORT TERM SPS IF THE HEAVIER SNOW BURSTS APPEAR TO BE MORE LIKELY
LATER ON. ALL FORECAST CHANGES HAVE BEEN INCORPORATED INTO THE
UPDATE WITH THE MAIN IMPACTS TO JUST HAVE LESS FREEZING RAIN
POTENTIAL.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 320 PM EST SUN MAR 1 2015
ZONAL FLOW WILL HOLD ON THROUGH THE NIGHT AS A WEAK SURFACE BOUNDARY
FINALLY SHIFTS EASTWARD AND OUT OF THE REGION BY 12Z MONDAY MORNING.
THIS WILL LEAD TO CONTINUED RAIN CHANCES LATE THIS AFTERNOON AND
EVENING...POSSIBLY MIXING WITH SOME FREEZING RAIN AND EVENTUALLY
SNOW BEFORE TAPERING OFF MONDAY MORNING/EARLY AFTERNOON. AS ROAD
TEMPERATURES WARM THROUGHOUT TODAY...EXPECT THEM TO LAG BEHIND THE
AIR TEMPERATURE FALLING OVERNIGHT BY AT LEAST AN HOUR OR
TWO...THOUGH A FAIRLY STRONG WARM NOSE EXISTS BETWEEN 6 AND 12Z
ACROSS EASTERN KY. EXPECT THE FREEZING RAIN TO OCCUR AS THE RAIN IS
SWITCHING OVER TO SNOW...WITH SOME MIXING POSSIBLE THROUGH 12Z. MOST
OF THE IMPACTS WILL LIKELY BE OVER THE NORTHER HALF OF THE
CWA...WHERE TEMPS WILL BE THE COLDEST.
UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE IS EXPECTED TO TAKE
HOLD DURING THE DAY TOMORROW. DRY AIR WILL QUICKLY CUT OFF ANY
LINGERING PRECIP BY LATE TOMORROW MORNING ACROSS EASTERN KY...AND
ALLOW FOR SOME BREAKING UP OF THE ONGOING CLOUD COVER. UNDER LIGHT
WINDS...AND WITHOUT THE INFLUENCE OF THE SOUTHERLY FLOW WE HAD
TODAY...EXPECT TEMPS TO BE SLIGHTLY COOLER IN THE AFTERNOON...ONLY
REACHING THE UPPER 30S TO LOW 40S. THIS SYSTEM WILL BE VERY SHORT
LIVED UNFORTUNATELY...AS THE HIGH PRESSURE QUICKLY SHIFTS EAST OF
THE REGION BY 6Z TUESDAY...WINDS BECOME MORE SRLY ONCE MORE...AND WE
START TO SEE THE INFLUENCES OF OUR NEXT APPROACHING SYSTEM.
CLOUDS WILL BE INCREASING THROUGHOUT THE NIGHT TUESDAY NIGHT...AS A
SURFACE LOW PRESSURE SYSTEM APPROACHES FROM THE CENTRAL
PLAINS...FOLLOWING THE UPPER LEVEL RIDGING PATTERN AND SHIFTING
NORTH EASTWARD THROUGH THE DAY TUESDAY. WITH STRONG SRLY FLOW
PULLING IN DECENT GULF MOISTURE...EXPECT PRECIP TO BEGIN WELL AHEAD
OF THIS SYSTEM...WITH POPS EXPECTED IN EASTERN KY AS EARLY AS LATE
TUESDAY NIGHT. THOUGH SURFACE TEMPS WILL REMAIN NEAR OR BELOW
FREEZING BY TUESDAY MORNING...THIS STRONGER SRLY FLOW WILL INTRODUCE
AN IMPRESSIVELY LARGE WARM NOSE INTO THE LOWER LEVELS. ONCE
AGAIN...THIS LOOKS LIKE A GOOD SET UP FOR SOME FREEZING RAIN AT THE
ONSET THROUGH 12Z...EVENTUALLY CHANGING TO ALL RAIN AS TEMPS CONTINUE
TO WARM AT THE SURFACE AND ALOFT THROUGH THE DAY TUESDAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 355 PM EST SUN MAR 1 2015
THE MODELS REMAIN IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE
PATTERN CONTINUING TO RULE ACROSS THE CONUS THROUGH THE END OF THE
WORKWEEK...BEFORE DAMPENING A BIT NEXT WEEKEND. A POSITIVELY
TILTED TROUGH OUT WEST WILL RESULT IN DEEP SOUTHWEST FLOW SETTING
UP ACROSS THE MISSISSIPPI VALLEY. THIS WILL ALLOW FOR A STOUT
BAROCLINIC ZONE TO MEANDER THROUGH THE OHIO AND TENNESSEE VALLEYS
THROUGH THE MIDDLE OF THE WEEK...WITH MUCH WARMER AND WETTER AIR
BEING ADVECTED INTO THE REGION. ANOTHER SHARP COOL DOWN WILL
FOLLOW...WITH ANY LINGERING PRECIPITATION GOING OVER TO SNOW
BEFORE ENDING THE WEEK MUCH COLDER AND DRIER.
DETAILS ON WHERE THE AXIS OF HEAVIER PRECIPITATION SETS UP AND
LINGERS WILL LIKELY CONTINUE TO VARY OVER THE COMING DAYS. AS
SUCH...HAVE CONTINUED TO STICK TO A GENERAL BLEND OF THE
SOLUTIONS...INCLUDING THE QPF AMOUNTS. IN GENERAL...THE MODELS
CONTINUE TO PAINT 2 TO 3 INCHES OF PRECIPITATION ACROSS THE AREA
BETWEEN TUESDAY AFTERNOON AND THURSDAY MORNING. THE BULK OF THIS
WILL FALL TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...WITH HEAVIER
AMOUNTS STARTING OUT IN THE NORTHWEST...AND THEN EVENTUALLY
SPREADING TO THE SOUTHEAST WITH TIME. THIS WILL BE MORE THAN
ENOUGH TO CAUSE FLOODING CONCERNS AND WILL CONTINUE TO HIGHLIGHT
THIS THREAT IN AN ONGOING HYDROLOGIC OUTLOOK.
PRECIPITATION MAY START OUT AS A WINTRY MIX OF FREEZING RAIN AND
RAIN FOR THE NORTHEAST PORTION OF THE AREA EARLY TUESDAY...
BEFORE QUICKLY GOING OVER TO JUST RAIN AS MUCH WARMER AIR ADVECTS
INTO THE REGION. A SURFACE WARM FRONT WILL LIFT THROUGH DURING THE
DAY...WITH THE BETTER RAINFALL AMOUNTS LIKELY FALLING WEST OF I-75
AND NEAR THE I-64 CORRIDOR...AS SOME DOWNSLOPING MAY CUT INTO
TOTALS TO THE SOUTHEAST. THE COLD FRONT WILL FOLLOW AND VERY
GRADUALLY SLIDE SOUTHEAST THROUGH THE AREA TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...PROVIDING THE BULK OF THE HEAVIER RAINFALL.
MUCH COLDER AIR WILL MOVE IN WEDNESDAY NIGHT INTO THURSDAY BEHIND
THE FRONT...WITH ANY LINGERING PRECIPITATION GOING OVER TO
SNOW...WITH SOME LIGHT ACCUMULATIONS POSSIBLE. SOME OF THE MODELS
ARE INDICATING THAT THE COLD AIR WILL MAKE IT IN BEFORE THE DEEPER
MOISTURE EXITS...IN PARTICULAR THE ECMWF...RESULTING IN THE
POTENTIAL FOR A GOOD WINDOW OF HEAVY WET SNOW. THIS IS NOT A
TYPICAL OUTCOME FOR THIS PATTERN...BUT WILL STILL NEED TO BE
WATCHED IN THE COMING DAYS.
AFTER ENJOYING HIGHS IN THE 50S TUESDAY AND WEDNESDAY...READINGS
WILL FALL BACK INTO THE 20S AND 30S FOR THURSDAY...WITH LOWS
BOTTOMING OUT NEAR THE 10 DEGREE MARK FRIDAY MORNING. HIGHS WILL
RETURN TO THE 40S FOR SATURDAY AND SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 641 PM EST SUN MAR 1 2015
NEAR LIFR CIGS WILL CONTINUE TO PUSH SOUTH ACROSS EASTERN KENTUCKY
THIS EVENING. THIS WILL ESSENTIALLY PUT CIGS AT OR BELOW AIRPORT
MINIMUMS THROUGH MUCH OF THE NIGHT WITH LITTLE IMPROVEMENT
EXPECTED. IN ADDITION...VISIBILITIES WILL BE SHARPLY REDUCED AT
TIMES...ALSO WITH A CHANCE TO GO UNDER AIRPORT MINIMUMS AT TIMES.
THIS WILL YIELD A VERY BAD CONDITIONS FOR AVIATION CUSTOMERS. CIGS
SHOULD BREAK UP AND LIFT TOMORROW MORNING AS THE FRONTAL BOUNDARY
SHIFTS SOUTH OF THE AREA. THIS WILL ALLOW FOR A RETURN TO VFR
CONDITIONS BY MIDDAY TOMORROW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
641 PM EST SUN MAR 1 2015
.UPDATE...
ISSUED AT 641 PM EST SUN MAR 1 2015
UPDATED TO REMOVE POPS THROUGH THE EVENING AS WE REMAIN DRY
SLOTTED. HOWEVER...THE COLD FRONT...CURRENTLY PUSHING SOUTH ACROSS
NORTHERN KENTUCKY WILL SLIP SOUTH LATER THIS EVENING AND
OVERNIGHT. AS THIS HAPPENS...A MID LEVEL WAVE WILL PUSH EAST WITH
MOISTURE RAPIDLY INCREASING ALONG THE FRONTAL ZONE. THIS WILL MEAN
INCREASING PRECIPITATION CHANCES INTO THE OVERNIGHT HOURS. AS THE
FRONT SLIPS SOUTH...PRECIPITATION WILL END FROM NORTH TO SOUTH
THROUGH THE OVERNIGHT HOURS. PRECIPITATION WILL LIKELY HOLD ON THE
LONGEST IN SOUTHEAST KENTUCKY. ADJUSTED THE POPS TO REFLECT THE
HIGHEST PRECIPITATION CHANCES (CATEGORICAL) IN SOUTHEAST
KENTUCKY...TRAILING OFF TO JUST CHANCE IN THE NORTH...WHERE THE
FRONT WILL PUSH THROUGH MUCH FASTER THIS EVENING. HRRR CONTINUES
TO SHOW A GOOD HANDLE ON PRECIPITATION COVERAGE THIS EVENING...SO
WILL CONTINUE TO FOLLOW IT FAIRLY CLOSELY WITH EXPECTED ARRIVAL OF
MORE WIDESPREAD PRECIPITATION OVERNIGHT. THE PATTERN WOULD SUGGEST
TEMPERATURES WILL HAVE A TOUGH TIME COOLING FAST ENOUGH TO ALLOW
FOR MUCH FREEZING RAIN AND WITH GROUND TEMPERATURES FAIRLY WARM
GOING INTO THINGS TONIGHT...NOT NEARLY AS CONCERNED ABOUT ICING
TONIGHT. HOWEVER...THE CONVECTIVE NATURE OF THE HRRR WOULD SUGGEST
SOME PRECIPITATION RATES COULD GET FAIRLY GOOD LATER
TONIGHT...PERHAPS ALLOWING A QUICK CHANGEOVER TO SNOW IN THE
HEAVIER SHOWERS. THIS WOULD SEEM REASONABLE AND WILL HAVE TO WATCH
FOR THIS AS THIS COULD PUT DOWN A QUICK COATING OF SNOW IN SOME
AREAS...LEADING TO SOME SLICK ROADS. AT THE SAME
TIME...TEMPERATURES ARE NOT EXPECTED TO FALL MUCH BELOW FREEZING
FOR MUCH OF THE AREA...SO ANY SNOW MAY NOT LAST ON ROADS GIVEN THE
WARMTH TODAY. THUS...IT MAY JUST BE A VERY SHORT TERM ISSUE TO
CONTEND WITH OVERNIGHT FOR THOSE DRIVING ACROSS EASTERN
KENTUCKY...ESPECIALLY SOUTHEAST KENTUCKY. WE MAY CONSIDER DOING A
SHORT TERM SPS IF THE HEAVIER SNOW BURSTS APPEAR TO BE MORE LIKELY
LATER ON. ALL FORECAST CHANGES HAVE BEEN INCORPORATED INTO THE
UPDATE WITH THE MAIN IMPACTS TO JUST HAVE LESS FREEZING RAIN
POTENTIAL.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 320 PM EST SUN MAR 1 2015
ZONAL FLOW WILL HOLD ON THROUGH THE NIGHT AS A WEAK SURFACE BOUNDARY
FINALLY SHIFTS EASTWARD AND OUT OF THE REGION BY 12Z MONDAY MORNING.
THIS WILL LEAD TO CONTINUED RAIN CHANCES LATE THIS AFTERNOON AND
EVENING...POSSIBLY MIXING WITH SOME FREEZING RAIN AND EVENTUALLY
SNOW BEFORE TAPERING OFF MONDAY MORNING/EARLY AFTERNOON. AS ROAD
TEMPERATURES WARM THROUGHOUT TODAY...EXPECT THEM TO LAG BEHIND THE
AIR TEMPERATURE FALLING OVERNIGHT BY AT LEAST AN HOUR OR
TWO...THOUGH A FAIRLY STRONG WARM NOSE EXISTS BETWEEN 6 AND 12Z
ACROSS EASTERN KY. EXPECT THE FREEZING RAIN TO OCCUR AS THE RAIN IS
SWITCHING OVER TO SNOW...WITH SOME MIXING POSSIBLE THROUGH 12Z. MOST
OF THE IMPACTS WILL LIKELY BE OVER THE NORTHER HALF OF THE
CWA...WHERE TEMPS WILL BE THE COLDEST.
UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE IS EXPECTED TO TAKE
HOLD DURING THE DAY TOMORROW. DRY AIR WILL QUICKLY CUT OFF ANY
LINGERING PRECIP BY LATE TOMORROW MORNING ACROSS EASTERN KY...AND
ALLOW FOR SOME BREAKING UP OF THE ONGOING CLOUD COVER. UNDER LIGHT
WINDS...AND WITHOUT THE INFLUENCE OF THE SOUTHERLY FLOW WE HAD
TODAY...EXPECT TEMPS TO BE SLIGHTLY COOLER IN THE AFTERNOON...ONLY
REACHING THE UPPER 30S TO LOW 40S. THIS SYSTEM WILL BE VERY SHORT
LIVED UNFORTUNATELY...AS THE HIGH PRESSURE QUICKLY SHIFTS EAST OF
THE REGION BY 6Z TUESDAY...WINDS BECOME MORE SRLY ONCE MORE...AND WE
START TO SEE THE INFLUENCES OF OUR NEXT APPROACHING SYSTEM.
CLOUDS WILL BE INCREASING THROUGHOUT THE NIGHT TUESDAY NIGHT...AS A
SURFACE LOW PRESSURE SYSTEM APPROACHES FROM THE CENTRAL
PLAINS...FOLLOWING THE UPPER LEVEL RIDGING PATTERN AND SHIFTING
NORTH EASTWARD THROUGH THE DAY TUESDAY. WITH STRONG SRLY FLOW
PULLING IN DECENT GULF MOISTURE...EXPECT PRECIP TO BEGIN WELL AHEAD
OF THIS SYSTEM...WITH POPS EXPECTED IN EASTERN KY AS EARLY AS LATE
TUESDAY NIGHT. THOUGH SURFACE TEMPS WILL REMAIN NEAR OR BELOW
FREEZING BY TUESDAY MORNING...THIS STRONGER SRLY FLOW WILL INTRODUCE
AN IMPRESSIVELY LARGE WARM NOSE INTO THE LOWER LEVELS. ONCE
AGAIN...THIS LOOKS LIKE A GOOD SET UP FOR SOME FREEZING RAIN AT THE
ONSET THROUGH 12Z...EVENTUALLY CHANGING TO ALL RAIN AS TEMPS CONTINUE
TO WARM AT THE SURFACE AND ALOFT THROUGH THE DAY TUESDAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 355 PM EST SUN MAR 1 2015
THE MODELS REMAIN IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE
PATTERN CONTINUING TO RULE ACROSS THE CONUS THROUGH THE END OF THE
WORKWEEK...BEFORE DAMPENING A BIT NEXT WEEKEND. A POSITIVELY
TILTED TROUGH OUT WEST WILL RESULT IN DEEP SOUTHWEST FLOW SETTING
UP ACROSS THE MISSISSIPPI VALLEY. THIS WILL ALLOW FOR A STOUT
BAROCLINIC ZONE TO MEANDER THROUGH THE OHIO AND TENNESSEE VALLEYS
THROUGH THE MIDDLE OF THE WEEK...WITH MUCH WARMER AND WETTER AIR
BEING ADVECTED INTO THE REGION. ANOTHER SHARP COOL DOWN WILL
FOLLOW...WITH ANY LINGERING PRECIPITATION GOING OVER TO SNOW
BEFORE ENDING THE WEEK MUCH COLDER AND DRIER.
DETAILS ON WHERE THE AXIS OF HEAVIER PRECIPITATION SETS UP AND
LINGERS WILL LIKELY CONTINUE TO VARY OVER THE COMING DAYS. AS
SUCH...HAVE CONTINUED TO STICK TO A GENERAL BLEND OF THE
SOLUTIONS...INCLUDING THE QPF AMOUNTS. IN GENERAL...THE MODELS
CONTINUE TO PAINT 2 TO 3 INCHES OF PRECIPITATION ACROSS THE AREA
BETWEEN TUESDAY AFTERNOON AND THURSDAY MORNING. THE BULK OF THIS
WILL FALL TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...WITH HEAVIER
AMOUNTS STARTING OUT IN THE NORTHWEST...AND THEN EVENTUALLY
SPREADING TO THE SOUTHEAST WITH TIME. THIS WILL BE MORE THAN
ENOUGH TO CAUSE FLOODING CONCERNS AND WILL CONTINUE TO HIGHLIGHT
THIS THREAT IN AN ONGOING HYDROLOGIC OUTLOOK.
PRECIPITATION MAY START OUT AS A WINTRY MIX OF FREEZING RAIN AND
RAIN FOR THE NORTHEAST PORTION OF THE AREA EARLY TUESDAY...
BEFORE QUICKLY GOING OVER TO JUST RAIN AS MUCH WARMER AIR ADVECTS
INTO THE REGION. A SURFACE WARM FRONT WILL LIFT THROUGH DURING THE
DAY...WITH THE BETTER RAINFALL AMOUNTS LIKELY FALLING WEST OF I-75
AND NEAR THE I-64 CORRIDOR...AS SOME DOWNSLOPING MAY CUT INTO
TOTALS TO THE SOUTHEAST. THE COLD FRONT WILL FOLLOW AND VERY
GRADUALLY SLIDE SOUTHEAST THROUGH THE AREA TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...PROVIDING THE BULK OF THE HEAVIER RAINFALL.
MUCH COLDER AIR WILL MOVE IN WEDNESDAY NIGHT INTO THURSDAY BEHIND
THE FRONT...WITH ANY LINGERING PRECIPITATION GOING OVER TO
SNOW...WITH SOME LIGHT ACCUMULATIONS POSSIBLE. SOME OF THE MODELS
ARE INDICATING THAT THE COLD AIR WILL MAKE IT IN BEFORE THE DEEPER
MOISTURE EXITS...IN PARTICULAR THE ECMWF...RESULTING IN THE
POTENTIAL FOR A GOOD WINDOW OF HEAVY WET SNOW. THIS IS NOT A
TYPICAL OUTCOME FOR THIS PATTERN...BUT WILL STILL NEED TO BE
WATCHED IN THE COMING DAYS.
AFTER ENJOYING HIGHS IN THE 50S TUESDAY AND WEDNESDAY...READINGS
WILL FALL BACK INTO THE 20S AND 30S FOR THURSDAY...WITH LOWS
BOTTOMING OUT NEAR THE 10 DEGREE MARK FRIDAY MORNING. HIGHS WILL
RETURN TO THE 40S FOR SATURDAY AND SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 641 PM EST SUN MAR 1 2015
NEAR LIFR CIGS WILL CONTINUE TO PUSH SOUTH ACROSS EASTERN KENTUCKY
THIS EVENING. THIS WILL ESSENTIALLY PUT CIGS AT OR BELOW AIRPORT
MINIMUMS THROUGH MUCH OF THE NIGHT WITH LITTLE IMPROVEMENT
EXPECTED. IN ADDITION...VISIBILITIES WILL BE SHARPLY REDUCED AT
TIMES...ALSO WITH A CHANCE TO GO UNDER AIRPORT MINIMUMS AT TIMES.
THIS WILL YIELD A VERY BAD CONDITIONS FOR AVIATION CUSTOMERS. CIGS
SHOULD BREAK UP AND LIFT TOMORROW MORNING AS THE FRONTAL BOUNDARY
SHIFTS SOUTH OF THE AREA. THIS WILL ALLOW FOR A RETURN TO VFR
CONDITIONS BY MIDDAY TOMORROW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
920 PM EST SUN MAR 1 2015
.SYNOPSIS...
LOW PRESSURE WILL APPROACH THE REGION FROM OHIO VALLEY THIS
EVENING AND MOVING THROUGH THE REGION LATER TONIGHT INTO MONDAY.
THIS SYSTEM WILL BRING SOME SNOW TO THE FORECAST AREA. HIGH
PRESSURE WILL BUILD TOWARD THE AREA MONDAY NIGHT AND TUESDAY FROM
THE WEST. ANOTHER LOW WILL CROSS THE REGION WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
920 PM UPDATE...A WEAK AREA OF LOW PRES WILL PASS SOUTH OF THE
GULF OF MAINE OVERNIGHT AND INTENSIFY RAPIDLY MON MORNING AS IT
BEGINS TO LIFT OUT ACROSS THE MARITIMES. SNOW IS FALLING ACROSS
SOUTHERN MAINE AND WILL OVERSPREAD THE DOWN EAST REGION OVER THE
NEXT 1 TO 2 HOURS. THE LATEST RAP AND HRRR HAVE MOST OF THE SNOW
OUT OF THE AREA BY 10Z AND THIS LOOKS REASONABLE BASED ON THE
LATEST RADAR TRENDS. AREAS ALONG THE COAST WILL PICK UP THE MOST
SNOWFALL WITH AMOUNTS DROPPING OFF TO THE NORTH AND WEST. EXPECT
SOME SPOTS ALONG AND NEAR THE COAST MAY PICK UP A FEW INCHES OF
SNOW...BUT UNLIKELY THAT MANY AREAS RECEIVE ADVISORY LEVEL
SNOWFALL. WILL MAINTAIN THE CURRENT ADVISORIES BUT SUSPECT THE
MIDNIGHT SHIFT WILL BE ABLE TO TAKE THEM DOWN EARLY IN THE
MORNING. ALSO MADE SOME TWEAKS TO RAISE THE HOURLY TEMPS AND
OVERNIGHT LOWS A FEW DEGREES.
PREVIOUS DISCUSSION...
THINGS TO FOCUS ON THIS TERM WILL BE SNOWFALL AMOUNTS AND SNOW
SQUALL POTENTIAL ON MONDAY.
18Z SURFACE ANALYSIS SHOWED HIGH PRES S OF THE REGION RIDGING
ACROSS THE STATE OF MAINE. MID AND HIGH CLOUDS MOVING NE PER THE
LATEST SATELLITE IMAGERY WILL CAP ANY FURTHER PROGRESSION OF
TEMPERATURES THIS AFTERNOON. READINGS ACROSS NORTHERN AND WESTERN
AREAS HIT THE MID/UPPER 20S WHILE CENTRAL AND DOWNEAST CLOSED IN
AROUND 30. TEMPERATURES WILL FALL BACK AFTER SUNSET BUT W/THE
CLOUDS MOVING IN, ANY FURTHER DROP WILL BE SLOW OR EVEN READINGS
LEVELING OFF ESPECIALLY DOWNEAST AND THE COAST. NORTHERN AREAS
COULD SEE TEMPERATURES FALL OFF QUICKER AS INITIAL CLOUD SHIELD IS
THIN PER THE OBS. SNOW IS FORECAST TO BREAK OUT ACROSS THE
SOUTHERN AND DOWNEAST AREAS THIS EVENING. THE LATEST RUNS OF THE
RAP AND HRRR 3KM DOING WELL PER THE RADAR TRENDS AND METARS. THIS
SET OF GUIDANCE SHOWS SNOW SETTING UP LATER THAN PREVIOUSLY
EXPECTED. THEREFORE, PULLED BACK ON THE TIMING BY A FEW HRS. LOW
PRES MOVING E FROM THE OHIO VALLEY IS SHOWN BY THE MODEL GUIDANCE
TO RE-DEVELOP OFF THE MAINE COAST LATER TONIGHT W/AN INVERTED TROF
SETTING UP FOR A TIME ACROSS EASTERN SECTIONS. SOME FORCING IS
THERE AND W/TEH LLVL CONVERGENCE, THERE COULD BE A BRIEF PERIOD OF
MODERATE SNOW WHERE RATIOS OF 15-20:1 COULD BE REALIZED W/2-4 INCHES
OF SNOW FROM 06-12Z. THE HIGHEST SNOWFALL WILL BE ACROSS THE COAST
AND GIVEN THE 3-4 INCH AMOUNTS SHOWN, DECIDED TO ISSUE A WINTER
WEATHER ADVISORY FOR SNOW. THIS WAS COORDINATED W/GYX. FURTHER N
AND W, SNOWFALL AMOUNTS WILL DROP OFF AS DYNAMICS WILL BE WEAKER
W/A GENERAL 1-3 INCHES AT BEST.
FOR MONDAY, SNOWFALL WILL COME TO AN END QUICKLY ACROSS THE W AND
DOWNEAST REGION WHILE EASTERN AREAS INCLUDING EASTERN SECTION OF
AROOSTOOK COUNTY WILL HANG ON TO A PERIOD OF SNOW THROUGH 10 AM
OR SO. THINGS WILL TRANSITION TO A MORE SHOWERY NATURE FOR THE
SNOW W/A GOOD CHANCE FOR SOME SNOW SQUALLS. THE NAM AND GFS
SOUNDINGS POINT TO STEEPENING LAPSE RATES(6/5-7.0C/KM) AT
850-700MBS AND FORECAST CAPE OF 70+ JOULES. THIS WILL BE IN
ASSOCIATION W/AN ARCTIC FRONT THAT IS FORECAST TO SLIDE ACROSS THE
REGION MONDAY AFTERNOON. THE BTV SNOW SQUALL PARAMETER SHOWED 2
AREAS OF SQUALL POTENTIAL W/ONE ACROSS NORTHERN AND WESTERN AREAS
AND THE SECOND AREA ACROSS EASTERN MAINE. TEMPERATURES WILL DROP
OFF SHARPLY BEHIND THIS BOUNDARY AFTER 19Z(2 PM). A QUICK INCH OF
SNOW CAN BE EXPECTED W/THE SQUALLS ALONG W/WIND GUSTS UP TO 30
MPH. THIS SITUATION IS SIMILAR TO THE SQUALL EVENT THAT OCCURRED A
WEEK AGO(2/23)WHERE MOIST OFF THE OPEN ST. LAWRENCE COMBINED W/THE
FRONT AIDING IN SOME HEFTY SNOW SQUALLS/SNOW SHOWERS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
THE MAIN FORECAST CONCERN FOR THE SHORT TERM IS A QUICK MOVING
SHORTWAVE WHICH WILL AFFECT MOST OF NEW ENGLAND TUESDAY NIGHT INTO
WEDNESDAY. THE COMBINATION OF DPVA AND WAA WILL PROVIDE SUFFICIENT
LIFT TO PRODUCE LIGHT TO MODERATE SNOW ACROSS OUR CWA DURING THIS
TIME FRAME...WITH CONDITIONS EXPECTED TO DRY OUT QUICKLY WEDNESDAY
AFTERNOON. HAVE FOLLOWED CLOSELY TO CONSALL QPF WHICH RESULTS IN
A GENERAL 3 TO 5 INCHES OF SNOWFALL. THE HIGHEST AMOUNTS WILL
OCCUR DOWNEAST...BUT WITH TEMPS IN THE LOWER 40S WEDNESDAY
AFTERNOON...MUCH OF THE SNOW WILL COMPACT OR MELT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE UPPER LEVEL FLOW WILL BECOME ZONAL AND PROGRESSIVE DURING THE
EXTENDED FORECAST PERIOD...BRINGING A SERIES OF VERY WEAK
SHORTWAVES ACROSS THE NORTHEAST. THIS WILL RESULT IN SEASONABLY
COLD CONDITIONS WITH OCCASIONAL SNOW SHOWERS.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR DROPPING TO MVFR LATE THIS EVENING AND THEN IFR TO
LOW END MVFR OVERNIGHT FOR ALL TERMINALS. CONDITIONS ARE FORECAST
TO IMPROVE TO VFR FOR KBGR AND KBHB MIDDAY MONDAY W/THE NORTHERN
TERMINALS GOING FROM IFR TO MVFR.
SHORT TERM: MVFR TO IFR CONDITIONS SHOULD PREVAIL ACROSS THE CWA
TUESDAY NIGHT INTO WEDNESDAY MORNING IN ASSOCIATION WITH THE
AFOREMENTIONED SNOWFALL. CONDITIONS WILL IMPROVE WEDNESDAY
AFTERNOON.
&&
.MARINE...
NEAR TERM: PER COORDINATION W/GYX, DECIDED TO GO W/A GALE WARNING
FOR MONDAY AFTERNOON INTO THE EVENING DUE TO THE ARCTIC FRONT
MOVING ACROSS THE WATERS. NW WINDS W/CAA WILL ALLOW FOR WINDS TO
HIT 25 TO 30 W/GUSTS UP TO 35 KTS. BUFKIT PROFILES SHOW GUST
POTENTIAL TO 40 KTS OVER THE OUTER WATERS. MIDNIGHT CREW HAD THIS
HANDLED WELL AND STAYED CLOSE TO IT.
SHORT TERM: A SMALL CRAFT ADVISORY WILL LIKELY BE NEED FOR OUR
COASTAL MARINE ZONES TUESDAY NIGHT INTO WEDNESDAY AS STORM SYSTEMS
CROSSES THE AREA...CREATING BREEZY SOUTHWEST WINDS AND HIGH WAVES.
&&
.CLIMATE...
FEBRUARY ENDED AS THE ALL-TIME COLDEST MONTH ON RECORD
AT BANGOR AND THE COLDEST FEBRUARY ON RECORD AT CARIBOU. MORE
INFORMATION ON THE RECORD COLD MONTH IS AVAILABLE ON THE NEWS
HEADLINES ON THE TOP OF OUR WEB PAGE AT: WEATHER.GOV/CAR
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST
MONDAY FOR MEZ029-030.
MARINE...GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR
ANZ050>052.
&&
$$
NEAR TERM...CB/HEWITT
SHORT TERM...BERDES
LONG TERM...BERDES
AVIATION...CB/HEWITT/BERDES
MARINE...CB/HEWITT/BERDES
CLIMATE...CB
AREA FORECAST DISCUSSION
NWS CARIBOU ME
630 PM EST SUN MAR 1 2015
.SYNOPSIS...
LOW PRESSURE WILL APPROACH THE REGION FROM OHIO VALLEY THIS
EVENING AND MOVING THROUGH THE REGION LATER TONIGHT INTO MONDAY.
THIS SYSTEM WILL BRING SOME SNOW TO THE FORECAST AREA. HIGH
PRESSURE WILL BUILD TOWARD THE AREA MONDAY NIGHT AND TUESDAY FROM
THE WEST. ANOTHER LOW WILL CROSS THE REGION WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
630 PM UPDATE...LOW PRES OFF THE DELMARVA COAST THIS EVENING WILL
JOIN FORCES WITH A SYSTEM MOVING IN FROM THE WEST. THE SFC LOW
WILL PASS JUST SOUTH OF THE GULF OF MAINE OVERNIGHT AND INTENSIFY
MON AS IT LIFTS NE ACROSS THE EASTERN MARITIMES. CLOUDS CONTINUE
TO STREAM ACROSS THE CWA EARLY THIS EVENING AND WILL LOWER AND
THICKEN UP. SNOW WILL BREAK OUT ACROSS DOWN EAST AREAS LATER THIS
EVENING AND SPREAD NORTH. THE HEAVIEST SNOWFALL STILL LOOKS TO BE
CONFINED TO AREAS ALONG AND NEAR THE COAST WITH AMOUNTS TO DROP
OFF TO THE NORTH. LITTLE/NO SNOW EXPECTED ACROSS NW MAINE. THE
MAIN CHANGE WITH THIS UPDATE WERE TO SLOW THE TIMING OF THE SNOW
A BIT BASED ON THE LATEST OBSERVATIONS...RADAR TRENDS...AND NEAR
TERM MODELS. THE SMOWFALL AMOUNTS WERE ALSO TWEAKED DOWN A BIT
ACROSS FAR NORTHERN AND NORTHWEST MAINE.
PREVIOUS DISCUSSION...
THINGS TO FOCUS ON THIS TERM WILL BE SNOWFALL AMOUNTS AND SNOW
SQUALL POTENTIAL ON MONDAY.
18Z SURFACE ANALYSIS SHOWED HIGH PRES S OF THE REGION RIDGING
ACROSS THE STATE OF MAINE. MID AND HIGH CLOUDS MOVING NE PER THE
LATEST SATELLITE IMAGERY WILL CAP ANY FURTHER PROGRESSION OF
TEMPERATURES THIS AFTERNOON. READINGS ACROSS NORTHERN AND WESTERN
AREAS HIT THE MID/UPPER 20S WHILE CENTRAL AND DOWNEAST CLOSED IN
AROUND 30. TEMPERATURES WILL FALL BACK AFTER SUNSET BUT W/THE
CLOUDS MOVING IN, ANY FURTHER DROP WILL BE SLOW OR EVEN READINGS
LEVELING OFF ESPECIALLY DOWNEAST AND THE COAST. NORTHERN AREAS
COULD SEE TEMPERATURES FALL OFF QUICKER AS INITIAL CLOUD SHIELD IS
THIN PER THE OBS. SNOW IS FORECAST TO BREAK OUT ACROSS THE
SOUTHERN AND DOWNEAST AREAS THIS EVENING. THE LATEST RUNS OF THE
RAP AND HRRR 3KM DOING WELL PER THE RADAR TRENDS AND METARS. THIS
SET OF GUIDANCE SHOWS SNOW SETTING UP LATER THAN PREVIOUSLY
EXPECTED. THEREFORE, PULLED BACK ON THE TIMING BY A FEW HRS. LOW
PRES MOVING E FROM THE OHIO VALLEY IS SHOWN BY THE MODEL GUIDANCE
TO RE-DEVELOP OFF THE MAINE COAST LATER TONIGHT W/AN INVERTED TROF
SETTING UP FOR A TIME ACROSS EASTERN SECTIONS. SOME FORCING IS
THERE AND W/TEH LLVL CONVERGENCE, THERE COULD BE A BRIEF PERIOD OF
MODERATE SNOW WHERE RATIOS OF 15-20:1 COULD BE REALIZED W/2-4 INCHES
OF SNOW FROM 06-12Z. THE HIGHEST SNOWFALL WILL BE ACROSS THE COAST
AND GIVEN THE 3-4 INCH AMOUNTS SHOWN, DECIDED TO ISSUE A WINTER
WEATHER ADVISORY FOR SNOW. THIS WAS COORDINATED W/GYX. FURTHER N
AND W, SNOWFALL AMOUNTS WILL DROP OFF AS DYNAMICS WILL BE WEAKER
W/A GENERAL 1-3 INCHES AT BEST.
FOR MONDAY, SNOWFALL WILL COME TO AN END QUICKLY ACROSS THE W AND
DOWNEAST REGION WHILE EASTERN AREAS INCLUDING EASTERN SECTION OF
AROOSTOOK COUNTY WILL HANG ON TO A PERIOD OF SNOW THROUGH 10 AM
OR SO. THINGS WILL TRANSITION TO A MORE SHOWERY NATURE FOR THE
SNOW W/A GOOD CHANCE FOR SOME SNOW SQUALLS. THE NAM AND GFS
SOUNDINGS POINT TO STEEPENING LAPSE RATES(6/5-7.0C/KM) AT
850-700MBS AND FORECAST CAPE OF 70+ JOULES. THIS WILL BE IN
ASSOCIATION W/AN ARCTIC FRONT THAT IS FORECAST TO SLIDE ACROSS THE
REGION MONDAY AFTERNOON. THE BTV SNOW SQUALL PARAMETER SHOWED 2
AREAS OF SQUALL POTENTIAL W/ONE ACROSS NORTHERN AND WESTERN AREAS
AND THE SECOND AREA ACROSS EASTERN MAINE. TEMPERATURES WILL DROP
OFF SHARPLY BEHIND THIS BOUNDARY AFTER 19Z(2 PM). A QUICK INCH OF
SNOW CAN BE EXPECTED W/THE SQUALLS ALONG W/WIND GUSTS UP TO 30
MPH. THIS SITUATION IS SIMILAR TO THE SQUALL EVENT THAT OCCURRED A
WEEK AGO(2/23)WHERE MOIST OFF THE OPEN ST. LAWRENCE COMBINED W/THE
FRONT AIDING IN SOME HEFTY SNOW SQUALLS/SNOW SHOWERS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
THE MAIN FORECAST CONCERN FOR THE SHORT TERM IS A QUICK MOVING
SHORTWAVE WHICH WILL AFFECT MOST OF NEW ENGLAND TUESDAY NIGHT INTO
WEDNESDAY. THE COMBINATION OF DPVA AND WAA WILL PROVIDE SUFFICIENT
LIFT TO PRODUCE LIGHT TO MODERATE SNOW ACROSS OUR CWA DURING THIS
TIME FRAME...WITH CONDITIONS EXPECTED TO DRY OUT QUICKLY WEDNESDAY
AFTERNOON. HAVE FOLLOWED CLOSELY TO CONSALL QPF WHICH RESULTS IN
A GENERAL 3 TO 5 INCHES OF SNOWFALL. THE HIGHEST AMOUNTS WILL
OCCUR DOWNEAST...BUT WITH TEMPS IN THE LOWER 40S WEDNESDAY
AFTERNOON...MUCH OF THE SNOW WILL COMPACT OR MELT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE UPPER LEVEL FLOW WILL BECOME ZONAL AND PROGRESSIVE DURING THE
EXTENDED FORECAST PERIOD...BRINGING A SERIES OF VERY WEAK
SHORTWAVES ACROSS THE NORTHEAST. THIS WILL RESULT IN SEASONABLY
COLD CONDITIONS WITH OCCASIONAL SNOW SHOWERS.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR DROPPING TO MVFR LATER THIS EVENING AND THEN IFR
OVERNIGHT FOR ALL TERMINALS. CONDITIONS ARE FORECAST TO IMPROVE TO
VFR FOR KBGR AND KBHB MIDDAY MONDAY W/THE NORTHERN TERMINALS
GOING FROM IFR TO MVFR.
SHORT TERM: MVFR TO IFR CONDITIONS SHOULD PREVAIL ACROSS THE CWA
TUESDAY NIGHT INTO WEDNESDAY MORNING IN ASSOCIATION WITH THE
AFOREMENTIONED SNOWFALL. CONDITIONS WILL IMPROVE WEDNESDAY
AFTERNOON.
&&
.MARINE...
NEAR TERM: PER COORDINATION W/GYX, DECIDED TO GO W/A GALE WARNING
FOR MONDAY AFTERNOON INTO THE EVENING DUE TO THE ARCTIC FRONT
MOVING ACROSS THE WATERS. NW WINDS W/CAA WILL ALLOW FOR WINDS TO
HIT 25 TO 30 W/GUSTS UP TO 35 KTS. BUFKIT PROFILES SHOW GUST
POTENTIAL TO 40 KTS OVER THE OUTER WATERS. MIDNIGHT CREW HAD THIS
HANDLED WELL AND STAYED CLOSE TO IT.
SHORT TERM: A SMALL CRAFT ADVISORY WILL LIKELY BE NEED FOR OUR
COASTAL MARINE ZONES TUESDAY NIGHT INTO WEDNESDAY AS STORM SYSTEMS
CROSSES THE AREA...CREATING BREEZY SOUTHWEST WINDS AND HIGH WAVES.
&&
.CLIMATE...FEBRUARY ENDED AS THE ALL-TIME COLDEST MONTH ON RECORD
AT BANGOR AND THE COLDEST FEBRUARY ON RECORD AT CARIBOU. MORE
INFORMATION ON THE RECORD COLD MONTH IS AVAILABLE ON THE NEWS
HEADLINES ON THE TOP OF OUR WEB PAGE AT: WEATHER.GOV/CAR
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST
MONDAY FOR MEZ029-030.
MARINE...GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR
ANZ050>052.
&&
$$
NEAR TERM...CB/HEWITT
SHORT TERM...BERDES
LONG TERM...BERDES
AVIATION...CB/HEWITT/BERDES
MARINE...CB/HEWITT/BERDES
CLIMATE...CB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
649 PM EST SUN MAR 1 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 422 PM EST SUN MAR 1 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF EXTENDING FROM
HUDSON BAY INTO THE NRN PLAINS. WITHIN TROF...NEXT SHORTWAVE OF
INTEREST IS NOW OVER THE DAKOTAS/MN. CLOSER TO HOME...SOME
-SHSH/FLURRIES HAVE SPREAD FROM WRN UPPER MI INTO PORTIONS OF CNTRL
UPPER MI TODAY IN VCNTY OF SFC TROF WHICH IS NOW ROUGHLY BISECTING
UPPER MI.
TONIGHT...SHORTWAVE NOW OVER THE DAKOTAS WILL SWING ACROSS THE WRN
GREAT LAKES THIS EVENING. AREA OF DEEP LAYER FORCING PER QVECTORS
SHIFTS ACROSS UPPER MI LATE THIS AFTN AND EVENING. WITH ASSOCIATED
BRIEF PERIOD OF DEEP MOISTURE...850MB TEMPS AROUND -18C...AND A
ROUGHLY 3KFT DGZ LAYER BTWN ROUGHLY 2K AND 5KFT...WOULD NORMALLY BE
CONCERNED ABOUT SEEING SEVERAL HRS OF HEALTHY LAKE ENHANCED SNOW IF
THE LAKE WASN`T MOSTLY ICE COVERED. THAT SAID...THE BRISK SW TO W
WINDS OF THE LAST COUPLE OF DAYS HAVE OPENED UP SOME NOTABLE GAPS IN
THE ICE...SO THERE WILL BE AN OPPORTUNITY FOR LOCALIZED MORE
PERSISTENT LES AND SOME SNOW ACCUMULATION. FROM TODAYS MODIS AND VIS
SATELLITE IMAGERY...A COUPLE OF IMPORTANT GAPS IN THE ICE ARE NOTED
FROM AROUND THE HURON ISLANDS DOWN PAST GRANITE ISLAND AND OVER TO N
OF MUNISING...AND ALSO IN THE AREA E OF THE APOSTLE ISLANDS WHICH
HAS CERTAINLY HAD A TENDENCY TO OPEN UP OVER THE LAST FEW WEEKS WHEN
WINDS ARE SW. WILL THUS HIT HIGHEST POPS AND 1-2 INCHES OF SNOW
DOWNWIND OF THESE OPEN WATER AREAS THIS EVENING (JUST N OF IRONWOOD
TO THE PORCUPINE MTNS AND ALSO ALGER COUNTY). STRONG NEGATIVE
DYNAMICS TAKE OVER DURING THE OVERNIGHT...SO LES INTENSITY WILL
DIMINISH RATHER QUICKLY AFTER MIDNIGHT. AWAY FROM THESE AREAS...
WNW/NW FLOW LES SHOULD BE NO MORE THAN SCT WITH ACCUMULATIONS UNDER
1 INCH. ELSEWHERE...EXPECT SOME FLURRIES IN MOST AREAS AS SHORTWAVE
PASSES. TEMPS IN THE INTERIOR W TOWARD THE WI BORDER SHOULD FALL
DOWN TOWARD ZERO WITH CLEARING SKIES OVERNIGHT. OTHERWISE...MIN
TEMPS SHOULD BE WITHIN A FEW DEGREES OF 10F.
ANY LINGERING LES TO THE E OF MARQUETTE WILL END BY MON AFTN UNDER
WAA/BACKING WINDS WITH PASSAGE OF SFC HIGH PRES RIDGE (BY MID AFTN
850MB TEMPS ARE FCST TO BE AROUND -12C). WHILE THERE MAY BE SOME
STRATOCU DEVELOPMENT EVEN WHERE SKIES ARE CLEAR TO START THE
DAY...EXPECT ALL AREAS TO BECOME SUNNY DURING THE DAY WITH DRY AIR
MASS AND DEPARTURE OF 850MB THERMAL TROF. HIGH TEMPS WILL RANGE FROM
AROUND 20 TO THE UPPER 20S...COOLEST OVER THE FAR E...CLOSER TO
DEPARTING THERMAL TROF.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 PM EST SUN MAR 1 2015
...WIDESPREAD SNOW TUESDAY MAY EVENTUALLY NEED A HEADLINE...
PRIMARY HIGHER IMPACT WEATHER THROUGH THE NEXT WEEK IS LIMITED TO
WIDESPREAD SNOW EXPECTED TO AFFECT THE AREA ON TUESDAY AND TUESDAY
EVENING. OTHERWISE...WARM UP EARLY IN THE WEEK WILL BE REPLACED BY A
COOL DOWN WEDNESDAY INTO THURSDAY IN WAKE OF THE TUESDAY SYSTEM. MAY
BE SOME LAKE EFFECT WEDNESDAY AND WEDNESDAY NIGHT BUT CHANCES WILL
BE HELD DOWN AS LAKE SUPERIOR REMAINS MOSTLY ICE COVERED. TEMPS
REBOUND AGAIN BY NEXT FRIDAY AND COULD STAY AT SIMILAR LEVELS INTO
NEXT WEEKEND.
HIGH PRESSURE EXITS EAST ON MONDAY EVENING WITH CLOUDS INCREASING
THROUGH THE NIGHT AHEAD OF A TWO-PIECED LOW PRESSURE SYSTEM HEADING
TOWARD REGION. NORTHERN STREAM WAVE AND ITS ASSOCIATED LOW SLIDES FM
NORTHERN MANITOBA TO NORTHERN ONTARIO BY DAYBREAK ON TUESDAY.
MEANWHILE THE SOUTHERN STREAM WAVE WILL PUSH OVER THE CENTRAL PLAINS
AS THE SFC LOW ARRIVES ALONG THE NEB/IOWA BORDER. MOISTURE ADVECTION
AHEAD OF THE LOW-MID LEVEL TROUGH MAXIMIZES OVERNIGHT BTWN H85 AND
H5. LIFT IS PRETTY STRONG WITHIN THE MOIST ADVECTION...SO SHOULD SEE
LGT SNOW BEGIN TO DEVELOP AFTER MIDNIGHT TOWARD WI BORDER WITH
LOWEST 100MB GRADUALLY SATURATING. HINTS ARE THERE THAT THE INITIAL
SNOW COULD BE DRIVEN BY FGEN...BUT WHERE MAX RIBBON OF HEAVIER SNOW
SETS UP IS NOT CERTAIN. 12Z NAM SHOWS IT MORE OVER WESTERN CWA...BUT
THIS IS AT ODDS WITH NAM DOMINATED SREF OUTPUT AND SEEMS TOO FAR
NORTH AS IT IS ALSO FARTHER NORTH WITH SOUTHERN STREAM SFC LOW ON
INTO TUESDAY. WILL KEEP WITH IDEA OF HEAVIER QPF/SNOW ON TUESDAY ON
EDGE OF GREATER H85-H7 MOISTURE TRANSPORT WHICH MAINLY IS MAXIMIZED
JUST TO THE SOUTH AND SOUTHEAST OF UPR MICHIGAN OUT AHEAD OF
SOUTHERN STREAM SFC LOW CROSSING LOWER MICHIGAN. H7 MIXING RATIOS
GFS/ECMWF STAY BLO 3G/KG THROUGHOUT TUESDAY. MIXING RATIOS INTO THE
SYSTEM AND BLEND OF QPF FM GFS/ECMWF ALONG WITH SLR/S CENTERED ON
15:1...SUGGEST ADVY LEVEL SNOWFALL SCNTRL CWA INTO THE EASTERN CWA.
WILL CONTINUE TO MENTION IN HWO/EHWO GRAPHICS.
PHASING BTWN THE NORTHERN STREAM WAVE AND SOUTHERN STREAM WAVES
NEVEN REALLY TAKES OFF SO THIS SYSTEM SHOULD STAY PROGRESSIVE ON
TUESDAY NIGHT AS MAIN CORE OF UPPER JET ENERGY STAYS OUT AHEAD OF
THE TROUGH. CHANCE POPS LINGER EARLY TUESDAY EVENING IN THE
EAST...BUT OTHERWISE POPS WITH THE SYSTEM WILL BE OUT OF THE AREA.
INITIALLY LAKE EFFECT IN WAKE OF THE SYNOPTIC SNOW ON TUESDAY
EVENING PROBABLY STAYS ON THE LIGHT SIDE DUE TO MARGINALLY COLD AIR
/H85 TEMPS WARMER THAN -15C/ AND MAINLY ICE COVERED LAKE SUPERIOR.
GFS SOUNDINGS SHOW INCREASE OF MOISTURE H8-H7 LATE TUESDAY NIGHT
INTO WEDNESDAY WHILE COLD AIR ADVECTION WITH H85 TEMPS FALLING BLO
-20C OVER LK SUPERIOR RESULTS IN INVERSIONS RISING UP TO A MAX OF
8KFT WEDNESDAY MORNING OVER EASTERN LK SUPERIOR. DESPITE THE HIGH
ICE COVERAGE...SCT POPS FOR LAKE EFFECT SNOW SHOWERS AND ALSO
FARTHER DOWNSTREAM OVER LAND AREAS WITH SOME HELP FM DAYTIME HEATING
AS THE HYBRID LAKE EFFECT SEASON IS UNDERWAY DUE TO HIGHER SUN
ANGLE. WITH NW WINDS UP TO 30 MPH ALONG THE LK SUPERIOR
SHORELINES...PROBABLY WILL HAVE BLSN/POOR VSBY IN THE SNOW BELTS
NEAR LK SUPERIOR EAST OF MQT. EVEN MINUS BLSN...LES WILL BE GOOD AT
REDUCING VSBY AS THE SNOWFLAKES WILL BE BECOMING SMALLER. H85 TEMPS
CONTINUE TO FALL BLO -25C BY LATE IN THE DAY ON WEDNESDAY...SO TEMPS
WILL BE STEADY OR SLOWLY FALL THROUGH THE DAY.
ARRIVAL OF HIGH PRESSURE RIDGE AND WINDS BACKING W-WSW BY THURSDAY
MORNING WILL DIMINISH ANY SNOW SHOWERS AS WINDS BECOME MORE
OFFSHORE. TEMPS OVER MUCH OF THE INTERIOR ON WEDNESDAY NIGHT COULD
TANK WELL UNDER 10 BLO ZERO. MAY SEE MARGINALLY LOW WIND CHILLS ON
THURSDAY MORNING...BUT FARTHER INLAND WHERE TEMPS WILL BE COLDEST
EXPECT THE WINDS TO BE NEARLY CALM. STILL COLD ON THURSDAY AS CORE
OF COLDER TEMPS ALOFT SLOWLY HEADS ACROSS EASTERN CANADA.
WARM FRONT MOVES TOWARD UPPER LAKES THURSDAY NIGHT INTO FRIDAY
MORNING. WARMING FIRST OCCURS ALOFT THEN MAKES ITS WAY TO SFC BY
FRIDAY AFTN. GFS SOUNDINGS SHOW MID LEVEL MOISTURE QUICKLY SWEEPS
ACROSS LEAVING SCT-BKN LOW CLOUDS LATER ON FRIDAY. MOISTURE AND LIFT
DOES NOT SYNC UP...SO NOT EXPECING MUCH IN WAY OF LGT SNOW. BETTER
LINKING OF LOW AND MID LEVEL MOISTURE IS OVER NORTHERN LK SUPERIOR
AND NORTHERN ONTARIO. DECENT AGREEMENT IN THIS IDEA FM GFS AND
ECMWF. COLD AIR NOT AS EMPHATIC FOR NEXT WEEKEND WITH GFS AND ECMWF
SHOWING H85 TEMPS MAINLY WARMER THAN -12C. GIVEN THE RUN-TO-RUN
DIFFERENCES IN MODELS AND DIFFERENCES IN MODEL SOLUTIONS...WILL JUST
RUN WITH CONSENSUS FRIDAY THROUGH SUNDAY. RESULT IS DAYTIME TEMPS IN
THE 20S TO NEAR 30 DEGREES AND ONLY SMALL CHANCES OF LGT SNOW MAINLY
OVER THE NORTH AND EAST CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1245 PM EST SUN MAR 1 2015
ANOTHER DISTURBANCE PASSING ACROSS THE AREA THIS EVENING SHOULD GIVE
A BOOST TO LAKE EFFECT -SHSN DESPITE A MOSTLY ICE COVERED LAKE
SUPERIOR. RECENT SW WINDS MAY HAVE OPENED UP AN AREA OF WATER E OF
THE APOSTLE ISLANDS. IF SO...SOME PERIODS OF IFR CONDITIONS IN -SHSH
MAY OCCUR AT KIWD THIS EVENING UNDER LOW-LEVEL WNW FLOW.
OTHERWISE...MVFR CONDITIONS SHOULD BE THE RULE AT KIWD/KCMX TONIGHT
WITH OCNL -SHSN. BACKING WINDS MORNING WILL BRING A RETURN OF VFR
CONDITIONS TO KIWD ON MON MORNING AND TO KCMX MON AFTERNOON. AT
KSAW...EXPECT VFR CONDITIONS TO PREVAIL TONIGHT THRU MON UNDER
DOWNSLOPE WNW FLOW. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 310 PM EST SUN MAR 1 2015
SEEMS THAT POTENTIAL FOR GALES IS INCREASING TUESDAY NIGHT INTO
WEDNESDAY IN WAKE OF COLD FRONT THAT MOVES THROUGH ON TUESDAY.
STRONGEST WINDS WOULD BE OVER THE EASTERN HALF OF LK SUPERIOR.
OTHERWISE...EXPECT WINDS THROUGH THE WEEK TO BE 15 TO 25 KTS.
LATEST OFFICIAL ICE CONCENTRATION ON LK SUPERIOR IS AROUND 95 PCT.
EVEN WITH STRONG WINDS AT TIMES THIS WEEK...EXPECT THE HIGHER ICE
COVERAGE TO PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...VOSS
MARINE...JLA
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 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 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 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 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 WILMINGTON NC
1000 PM EST SUN MAR 1 2015
.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN THROUGH MONDAY MORNING. A COLD FRONT
WILL MOVE THROUGH MONDAY AFTERNOON FOLLOWED BY COOL HIGH PRESSURE
TUESDAY. TEMPERATURES WILL RISE WELL ABOVE NORMAL WEDNESDAY AHEAD
OF A STRONG COLD FRONT THAT WILL CROSS THE AREA WEDNESDAY NIGHT.
LOW PRESSURE ALONG THE FRONT MAY KEEP WEATHER CONDITIONS UNSETTLED
ON THURSDAY. CHILLY HIGH PRESSURE WILL BUILD ACROSS THE CAROLINAS
FRIDAY INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 10 PM SUNDAY...NO CHANGES TO A DRIZZLY AND MIST-LADENED
FORECAST FOR THE OVERNIGHT PERIOD. MEASURABLE RAINFALL IS WINDING
DOWN AS LIGHT SHOWERS EDGE OFF THE COAST IN CONJUNCTION WITH
EXITING SHORT-WAVE ENERGY. A FEW SPRITZES CANNOT BE RULED OUT BUT
RAIN-BUCKET READINGS WILL REMAIN SCANT ASIDE FROM DRIZZLE TRACES.
MID-LEVEL DRYING IS UNDERWAY IN WESTERLY WIND FLOW BUT BELOW 950MB
FULLY SATURATED AIR WILL REMAIN ENTRENCHED AS A STABLE WEDGE HOLDS
ITS GROUND WHILE SLOWLY BEING SCRUBBED ALOFT BY 30KT DRIER WEST
WINDS. TEMPERATURES EXPECTED TO LEVEL OUT AFTER MIDNIGHT FOR THE
MOST PART AS BOUNDARY LAYER WEST WINDS SEE AN UPTICK IN SPEEDS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...PROGRESSIVE REGIME THROUGH THE PERIOD. ONE
WEDGE OF HIGH PRESSURE WILL COMPLETELY BREAK DOWN MON MORNING
AHEAD OF THE NEXT COLD FRONT WHICH WILL MOVE ACROSS THE EASTERN
CAROLINAS MON AFTERNOON. THERE COULD BE SOME VERY LIGHT
PRECIPITATION AROUND ON MON...DIFFICULT TO SAY WHETHER ISOLATED
SPOTS WILL RECEIVE MEASURABLE RAINFALL. WILL CONFINE POPS TO NEAR 20
PERCENT OR JUST BELOW ON MON. A VERY PRONOUNCED NEAR SURFACE
INVERSION WILL KEEP LOW CLOUDS/FOG AROUND FOR THE FIRST PART OF THE
MORNING. THIS STRONG INVERSION DOES FINALLY BREAK DOWN AND SO WE
MAY AT LEAST SEE SOME GLIMPSES OF SUNSHINE DURING MON.
ONCE THE COLD FRONT MOVES THROUGH...ANOTHER WEDGE OF HIGH PRESSURE
WILL BUILD ACROSS THE CAROLINAS MON NIGHT INTO TUE AS HIGH PRESSURE
MOVES OUT OF THE MID-WEST AND ACROSS THE MID-ATLANTIC STATES. THIS
WILL LOCK IN LOW-LEVEL MOISTURE...WITH WIDESPREAD LOW CLOUDS
EXPECTED TO REDEVELOP LATER MON NIGHT AND THEN PERSIST INTO TUE AS
COLD AIR ADVECTION REDEVELOPS ON LOW-LEVEL NE FLOW. ISENTROPIC
UPGLIDE IS EXPECTED TO DEVELOP MON NIGHT AS MOIST S TO SW OR WSW
WINDS ABOVE 2 KFT TOP THE COOL DOME OF AIR NEAR THE SURFACE.
ALSO...A COASTAL TROUGH IS EXPECTED TO DEVELOP LATE MON NIGHT AND
TUE. THIS TROUGH WILL LIFT ATLANTIC MOISTURE OVER THE TOP OF THE
LOW-LEVEL INVERSION AND NOT ONLY KEEP SKIES CLOUDY...BUT BRING MORE
WET WEATHER. THERE IS NO RISK OF ANY FREEZING OR FROZEN
PRECIPITATION. QPF AMOUNTS WILL BE LIGHT.
THE HIGH DOES MOVE OFF THE COAST LATE TUE AND TUE NIGHT AND THE
MODELS ARE IN A HURRY TO BREAK DOWN THE WEDGE. ALTHOUGH IT MAY
EVOLVE SLOWER THAN CURRENTLY PORTRAYED...IT DOES LOOK LIKE THE NEXT
COLD FRONT WILL BE STRONGER AND ITS PROXIMITY SHOULD ALLOW A WARMER
RETURN FLOW TO DEVELOP OVERNIGHT AT ALL LEVELS. WILL SHOW TEMPS
TRENDING HIGHER THROUGH THE NIGHT AS INCREASINGLY SOUTHERLY WINDS
DEVELOP.
TEMPS WILL BE BELOW NORMAL THROUGH THE PERIOD WITH MON LIKELY
CONSIDERABLY WARMER THAN TUE. HIGHS MON WILL BE IN THE UPPER 50S AND
LOWER 60S WITH SOME MID 60S POSSIBLE ALONG THE SOUTH SANTEE RIVER
AREA. WE WILL HAVE TO SUBTRACT A GOOD 10 DEGREES FROM THOSE VALUES
ON TUE. LOWS WILL BE MAINLY IN THE UPPER 30S AND LOWER 40S MON
NIGHT. LOWS TUE EVE WILL BE VERY NEAR THE HIGHS OF THE DAY AND
THEN MOVE UPWARDS FROM THERE DURING THE NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...VERY WARM START TO THE EXTENDED PERIOD WITH
WEDNESDAY BEING THE WARMEST DAY IN QUITE A WHILE. UPPER RIDGE WILL
HOLD ON UP THROUGH THE SOUTHEAST AS DEEP TROUGH DIGS DOWN THROUGH
THE MID WEST. THIS WILL AID IN KEEPING A DRIER AND WARMER DAY OVER
THE COASTAL CAROLINAS. ALTHOUGH OVERALL MOISTURE THROUGH THE COLUMN
IS GENERALLY HIGH WITH UP TO 1.3 INCHES OF PCP WATER WED
MORNING...THE SOUNDINGS AND MOISTURE PROFILES KEEP IT CONFINED TO
VERY LOW LEVELS AND VERY HIGH WITH A DECENT DRY LAYER THROUGH THE
MID LEVELS. THIS MAY ALLOW SOME BREAKS IN THE CLOUDS TO HELP PUSH
TEMPS WELL INTO THE 70S. THE COAST WILL NOT BE AS FORTUNATE AS
SOUTHERLY FLOW WILL BRING THE COOLER OCEAN AIR OVER THE BEACHES
ADVECTING INLAND A BIT. ALSO THE POTENTIAL FOR SEA FOG WILL EXIST AS
THE WARMER AIR RUSHES OVER THE COOLER WATERS. BY LATE WED SHWRS WILL
INCREASE AS COLD FRONT DRAWS CLOSER. WILL KEEP LOW END POPS OVER
PORTIONS OF AREA...MAINLY INLAND ON WED BUT EXPECT BEST CHC OF PCP
TO COME WED EVE INTO THURS. A STRONG COLD FRONT WILL CROSS THE AREA
WED NIGHT WITH PLENTY OF CAA TO FOLLOW. SEEMS LIKE MODELS ARE
COMING BACK TO AN EARLIER FROPA FOR WED NIGHT INSTEAD OF THURS. MAY
SEE MAX TEMPS FOR THURS AT MIDNIGHT WED NIGHT BEFORE DROPPING BEHIND
FRONT...ESPECIALLY ALONG COASTAL LOCATIONS WHERE FRONT WILL PASS
THROUGH AFTER MIDNIGHT. THE SHALLOW COOL AIR WILL COME RUSHING IN
BUT MID TO UPPER TROUGH HANGS BACK TO THE WEST. THIS WILL LEAD TO
SHORTWAVE ENERGY RIDING UP ALONG THE EAST SIDE OF THE TROUGH THROUGH
THE SOUTHEAST PRODUCING WAVES OF LOW PRESSURE DEVELOPING ALONG FRONT
WHICH SHOULD REMAINED ALIGNED SW TO NE JUST TO OUR SOUTH. THEREFORE
CLOUDS AND PCP SHOULD LINGER THROUGH THURS AND POSSIBLY LONGER.
ALTHOUGH COLD AIR WILL BE LOCKED IN AT THE SFC...WARMER AIR ALOFT
SHOULD KEEP ALL PCP AS A COLD RAIN BEHIND FRONT AT THIS POINT. THE
GFS DOES SHOW MAIN SHORTWAVE SWINGING OFF THE COAST BY FRI MORNING
AS SFC HIGH BUILDS OVER THE CAROLINAS...BUT A BROAD TROUGH REMAINS
OVER THE EAST WITH MORE OF A ZONAL FLOW ALOFT BUT THERE WILL BE
POTENTIAL FOR OTHER SHORTWAVES TO MOVE THROUGH. FOR NOW WILL REMAIN
MORE OPTIMISTIC FOR FRI INTO THE WEEKEND WITH A DRIER ALTHOUGH
COOLER FORECAST.
TEMPS WILL TAKE A DIVE ONCE COLD FRONT SHIFTS SOUTH WED NIGHT WITH
850 TEMPS UP AROUND 12C WED AFTN DROPPING DOWN JUST BELOW 0C BY FRI
MORNING. THIS STRONG CAA AND POSSIBLY LINGERING CLOUDS AND PCP WILL
KEEP VERY COOL TEMPS FOR THURS AND FRI. THE LATEST GUIDANCE SHOWS
MAX TEMPS ONLY REACHING INTO THE 40S ON THURS AND NOT EVEN REACHING
40 ON FRI IN MANY PLACES. FOR NOW...WILL TREND COOLER BUT NOT GET
THAT EXTREME JUST YET AS MODELS HAVE NOT REMAINED VERY CONSISTENT
WITH THIS SYSTEM FOR LATE WEEK. HESITANT ESPECIALLY ON FRI AS
SUNSHINE WILL MAKE ITS WAY OUT AND THIS TIME OF YEAR THE SUN IS
PLAYING A BIGGER ROLE IN WARMING.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
AS OF 03Z...RATHER LOW CONFIDENCE WITH THE NEXT SET OF TAFS AS
FRONT PRETTY MUCH LAYS OVER TOP OF US THROUGH THE FORECAST PERIOD.
CEILINGS WILL LIKELY BOUNCE FROM IFR TO MVFR BEFORE REMAINING
PREDOMINATELY IFR OVERNIGHT. LIGHT PRECIP ALONG THE COAST WILL
MOVE OUT OF THE REGION IN A FEW HOURS...AND THE HRRR MODEL SEEMS
TO HAVE A REASONABLE HANDLE ON IT. A WEAK TROUGH OF LOW PRESSURE
WILL GIVE US MAINLY WESTERLY WINDS OVERNIGHT...QUITE LIGHT. IFR
CONDITIONS WILL CONTINUE THROUGH THE MORNING HOURS ON MONDAY
BEFORE LIFTING TO MVFR OR BETTER. FRONT DROPS SOUTH OF THE REGION
MONDAY AFTERNOON...WITH WINDS SHIFTING TO THE NORTHEAST.
EXTENDED OUTLOOK...BECOMING VFR LATE MON. PERIODS OF MVFR/SHOWERS
TUE/WED. RAIN/IFR THUR. VFR DEVELOPING FRI.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 PM SUNDAY...PRESSURE GRADIENT WEAKENING AS WEDGE REMNANTS
ARE ALL BUT UNIDENTIFIABLE. REMNANTS ARE CAUSING SQUIRRELINESS IN
WIND DIRECTION...BUT WIND-SPEEDS NOT A HAZARD. GRADIENT TO REMAIN
WEAK AND WESTERLY FLOW LATE WILL CONTINUE TO RUN 10 KT OR LESS.
SEAS 4 TO 5 FT TO SUBSIDE TO 2 TO 4 FT INTO DAYBREAK.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...MARINERS SHOULD EXPECT CHANGEABLE WIND
DIRECTIONS THIS PERIOD. WINDS MON MORNING WILL BE WESTERLY...BUT
WITH THE PASSAGE OF A COLD FRONT WILL SHIFT TO N DURING THE
AFTERNOON. NE WINDS WILL BE NEAR SMALL CRAFT ADVISORY LEVELS MON
NIGHT AS A SURGE DEVELOPS IN RESPONSE TO A BUILDING WEDGE OF HIGH
PRESSURE. THE WIND DIRECTION WILL VEER TO EASTERLY DURING TUE AND
THEN SE AND S BY TUE EVE AS HIGH PRESSURE TO OUR NORTH MOVES FURTHER
OFFSHORE. WINDS OVERNIGHT TUE WILL VEER TO SW AHEAD OF A STRONG COLD
FRONT. THE STRONGEST WINDS ARE EXPECTED MON NIGHT...UP TO 20 TO 25
KT. SEAS WILL BE HIGHEST MON NIGHT INTO TUE...UP TO 4 TO 7 FT. SEAS
MAY APPROACH 6 FT TUE NIGHT...MAINLY ACROSS THE NORTHERN OFFSHORE
WATERS.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...SOUTHERLY WINDS WILL CONTINUE THROUGH WED UP
TO 15 TO 20 KTS KEEPING SEAS GENERALLY IN THE 4 TO 6 FT RANGE BUT
WILL INCREASE WED NIGHT INTO THURS AS COLD FRONT MOVES THROUGH. THE
TIGHTENED GRADIENT FLOW WILL PRODUCE WINDS UP NEAR 20 KTS AS THEY
SHIFT MORE ABRUPTLY AROUND FROM SW TO N BEHIND FRONT OVERNIGHT WED.
STRONG CAA AND TIGHTENED GRADIENT WILL KEEP SEAS UP TO 4 TO 7 FT
THURS. THE FRONT WILL LINGER TO THE SOUTH AS HIGH PRESSURE BUILDS
DOWN INTO THE WATERS FROM THE NW. THIS MAY KEEP A PROLONGED PERIOD
OF SCA CONDITIONS IN STRONG NORTHERLY WINDS THROUGH THURS INTO FRI.
WINDS WILL LIGHTEN THROUGH LATE FRI AND BECOME MORE VARIABLE INTO
THE WEEKEND AS HIGH PRESSURE SHIFTS CLOSER OVERHEAD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...RJD
LONG TERM...RGZ
AVIATION...DL
AREA FORECAST DISCUSSION...COR
NWS WILMINGTON NC
642 PM EST SUN MAR 1 2015
.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN THROUGH MONDAY MORNING. A COLD FRONT
WILL MOVE THROUGH MONDAY AFTERNOON FOLLOWED BY COOL HIGH PRESSURE
TUESDAY. TEMPERATURES WILL RISE WELL ABOVE NORMAL WEDNESDAY AHEAD
OF A STRONG COLD FRONT THAT WILL CROSS THE AREA WEDNESDAY NIGHT.
LOW PRESSURE ALONG THE FRONT MAY KEEP WEATHER CONDITIONS UNSETTLED
ON THURSDAY. CHILLY HIGH PRESSURE WILL BUILD ACROSS THE CAROLINAS
FRIDAY INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 642 PM SUNDAY...PATCHY DRIZZLE AND MIST ACCOMPANIED BY
LIGHT RAIN SHOWERS ENSHROUDED THE FORECAST AREA THIS EARLY
EVENING. A VARIETY OF REDUCED VISIBILITIES PLAGUED SE NC AND NE
SC...WITH A DECK OF LOW CEILINGS CAPPING SKIES IN A DAMP LOW-LVL
ATMOSPHERE. MEASURABLE RAINFALL PROBABILITIES WILL DWINDLE AS
SHORT-WAVE PERTURBATIONS PASS AFT 6Z OR SOONER...AS AGREED BY THE
MAJORITY OF NEAR TERM MODEL SOLUTIONS. COUNT ON PERIODS OF DRIZZLE
HOWEVER AND MIST FOR THE OVERNIGHT PERIOD AS A STUBBORN AND SHALLOW
BUT STABLE COOL WEDGE HANGS ON BENEATH PREDOMINANT SW WIND FLOW
ALOFT AS REVEALED IN KLTX VAD WIND PROFILE TIME LAPSE. AS A
CONSEQUENCE HOURLY TEMPERATURES WILL DROP ONLY QUITE SLOWLY AS RH
VALUES REMAIN PEGGED IN DESCENDING DZ/-RA. RAIN RATES OF TRACE TO
0.02 INCHES PER HOUR WILL PREVAIL THROUGH EVENING BEFORE THE RAIN
EXITS TO THE NE LATER TONIGHT...LEAVING A SLOWLY FADING WEDGE AND
OCCASIONAL DRIZZLE AND FOG IN ITS WAKE. LOWS DAYBREAK MONDAY UPPER
30S INLAND TO LOWER 40S CLOSER TO THE COAST...AND MIDDLE 40S AREA
BEACHES AND ICW CORRIDOR.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...PROGRESSIVE REGIME THROUGH THE PERIOD. ONE
WEDGE OF HIGH PRESSURE WILL COMPLETELY BREAK DOWN MON MORNING
AHEAD OF THE NEXT COLD FRONT WHICH WILL MOVE ACROSS THE EASTERN
CAROLINAS MON AFTERNOON. THERE COULD BE SOME VERY LIGHT
PRECIPITATION AROUND ON MON...DIFFICULT TO SAY WHETHER ISOLATED
SPOTS WILL RECEIVE MEASURABLE RAINFALL. WILL CONFINE POPS TO NEAR 20
PERCENT OR JUST BELOW ON MON. A VERY PRONOUNCED NEAR SURFACE
INVERSION WILL KEEP LOW CLOUDS/FOG AROUND FOR THE FIRST PART OF THE
MORNING. THIS STRONG INVERSION DOES FINALLY BREAK DOWN AND SO WE
MAY AT LEAST SEE SOME GLIMPSES OF SUNSHINE DURING MON.
ONCE THE COLD FRONT MOVES THROUGH...ANOTHER WEDGE OF HIGH PRESSURE
WILL BUILD ACROSS THE CAROLINAS MON NIGHT INTO TUE AS HIGH PRESSURE
MOVES OUT OF THE MID-WEST AND ACROSS THE MID-ATLANTIC STATES. THIS
WILL LOCK IN LOW-LEVEL MOISTURE...WITH WIDESPREAD LOW CLOUDS
EXPECTED TO REDEVELOP LATER MON NIGHT AND THEN PERSIST INTO TUE AS
COLD AIR ADVECTION REDEVELOPS ON LOW-LEVEL NE FLOW. ISENTROPIC
UPGLIDE IS EXPECTED TO DEVELOP MON NIGHT AS MOIST S TO SW OR WSW
WINDS ABOVE 2 KFT TOP THE COOL DOME OF AIR NEAR THE SURFACE.
ALSO...A COASTAL TROUGH IS EXPECTED TO DEVELOP LATE MON NIGHT AND
TUE. THIS TROUGH WILL LIFT ATLANTIC MOISTURE OVER THE TOP OF THE
LOW-LEVEL INVERSION AND NOT ONLY KEEP SKIES CLOUDY...BUT BRING MORE
WET WEATHER. THERE IS NO RISK OF ANY FREEZING OR FROZEN
PRECIPITATION. QPF AMOUNTS WILL BE LIGHT.
THE HIGH DOES MOVE OFF THE COAST LATE TUE AND TUE NIGHT AND THE
MODELS ARE IN A HURRY TO BREAK DOWN THE WEDGE. ALTHOUGH IT MAY
EVOLVE SLOWER THAN CURRENTLY PORTRAYED...IT DOES LOOK LIKE THE NEXT
COLD FRONT WILL BE STRONGER AND ITS PROXIMITY SHOULD ALLOW A WARMER
RETURN FLOW TO DEVELOP OVERNIGHT AT ALL LEVELS. WILL SHOW TEMPS
TRENDING HIGHER THROUGH THE NIGHT AS INCREASINGLY SOUTHERLY WINDS
DEVELOP.
TEMPS WILL BE BELOW NORMAL THROUGH THE PERIOD WITH MON LIKELY
CONSIDERABLY WARMER THAN TUE. HIGHS MON WILL BE IN THE UPPER 50S AND
LOWER 60S WITH SOME MID 60S POSSIBLE ALONG THE SOUTH SANTEE RIVER
AREA. WE WILL HAVE TO SUBTRACT A GOOD 10 DEGREES FROM THOSE VALUES
ON TUE. LOWS WILL BE MAINLY IN THE UPPER 30S AND LOWER 40S MON
NIGHT. LOWS TUE EVE WILL BE VERY NEAR THE HIGHS OF THE DAY AND
THEN MOVE UPWARDS FROM THERE DURING THE NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...VERY WARM START TO THE EXTENDED PERIOD WITH
WEDNESDAY BEING THE WARMEST DAY IN QUITE A WHILE. UPPER RIDGE WILL
HOLD ON UP THROUGH THE SOUTHEAST AS DEEP TROUGH DIGS DOWN THROUGH
THE MID WEST. THIS WILL AID IN KEEPING A DRIER AND WARMER DAY OVER
THE COASTAL CAROLINAS. ALTHOUGH OVERALL MOISTURE THROUGH THE COLUMN
IS GENERALLY HIGH WITH UP TO 1.3 INCHES OF PCP WATER WED
MORNING...THE SOUNDINGS AND MOISTURE PROFILES KEEP IT CONFINED TO
VERY LOW LEVELS AND VERY HIGH WITH A DECENT DRY LAYER THROUGH THE
MID LEVELS. THIS MAY ALLOW SOME BREAKS IN THE CLOUDS TO HELP PUSH
TEMPS WELL INTO THE 70S. THE COAST WILL NOT BE AS FORTUNATE AS
SOUTHERLY FLOW WILL BRING THE COOLER OCEAN AIR OVER THE BEACHES
ADVECTING INLAND A BIT. ALSO THE POTENTIAL FOR SEA FOG WILL EXIST AS
THE WARMER AIR RUSHES OVER THE COOLER WATERS. BY LATE WED SHWRS WILL
INCREASE AS COLD FRONT DRAWS CLOSER. WILL KEEP LOW END POPS OVER
PORTIONS OF AREA...MAINLY INLAND ON WED BUT EXPECT BEST CHC OF PCP
TO COME WED EVE INTO THURS. A STRONG COLD FRONT WILL CROSS THE AREA
WED NIGHT WITH PLENTY OF CAA TO FOLLOW. SEEMS LIKE MODELS ARE
COMING BACK TO AN EARLIER FROPA FOR WED NIGHT INSTEAD OF THURS. MAY
SEE MAX TEMPS FOR THURS AT MIDNIGHT WED NIGHT BEFORE DROPPING BEHIND
FRONT...ESPECIALLY ALONG COASTAL LOCATIONS WHERE FRONT WILL PASS
THROUGH AFTER MIDNIGHT. THE SHALLOW COOL AIR WILL COME RUSHING IN
BUT MID TO UPPER TROUGH HANGS BACK TO THE WEST. THIS WILL LEAD TO
SHORTWAVE ENERGY RIDING UP ALONG THE EAST SIDE OF THE TROUGH THROUGH
THE SOUTHEAST PRODUCING WAVES OF LOW PRESSURE DEVELOPING ALONG FRONT
WHICH SHOULD REMAINED ALIGNED SW TO NE JUST TO OUR SOUTH. THEREFORE
CLOUDS AND PCP SHOULD LINGER THROUGH THURS AND POSSIBLY LONGER.
ALTHOUGH COLD AIR WILL BE LOCKED IN AT THE SFC...WARMER AIR ALOFT
SHOULD KEEP ALL PCP AS A COLD RAIN BEHIND FRONT AT THIS POINT. THE
GFS DOES SHOW MAIN SHORTWAVE SWINGING OFF THE COAST BY FRI MORNING
AS SFC HIGH BUILDS OVER THE CAROLINAS...BUT A BROAD TROUGH REMAINS
OVER THE EAST WITH MORE OF A ZONAL FLOW ALOFT BUT THERE WILL BE
POTENTIAL FOR OTHER SHORTWAVES TO MOVE THROUGH. FOR NOW WILL REMAIN
MORE OPTIMISTIC FOR FRI INTO THE WEEKEND WITH A DRIER ALTHOUGH
COOLER FORECAST.
TEMPS WILL TAKE A DIVE ONCE COLD FRONT SHIFTS SOUTH WED NIGHT WITH
850 TEMPS UP AROUND 12C WED AFTN DROPPING DOWN JUST BELOW 0C BY FRI
MORNING. THIS STRONG CAA AND POSSIBLY LINGERING CLOUDS AND PCP WILL
KEEP VERY COOL TEMPS FOR THURS AND FRI. THE LATEST GUIDANCE SHOWS
MAX TEMPS ONLY REACHING INTO THE 40S ON THURS AND NOT EVEN REACHING
40 ON FRI IN MANY PLACES. FOR NOW...WILL TREND COOLER BUT NOT GET
THAT EXTREME JUST YET AS MODELS HAVE NOT REMAINED VERY CONSISTENT
WITH THIS SYSTEM FOR LATE WEEK. HESITANT ESPECIALLY ON FRI AS
SUNSHINE WILL MAKE ITS WAY OUT AND THIS TIME OF YEAR THE SUN IS
PLAYING A BIGGER ROLE IN WARMING.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...RATHER LOW CONFIDENCE WITH THE NEXT SET OF TAFS AS
FRONT PRETTY MUCH LAYS OVER TOP OF US THROUGH THE FORECAST PERIOD.
CEILINGS WILL LIKELY BOUNCE FROM IFR TO MVFR BEFORE REMAINING
PREDOMINATELY IFR OVERNIGHT. LIGHT PRECIP ALONG THE COAST WILL
MOVE OUT OF THE REGION IN A FEW HOURS...AND THE HRRR MODEL SEEMS
TO HAVE A REASONABLE HANDLE ON IT. A WEAK TROUGH OF LOW PRESSURE
WILL GIVE US MAINLY WESTERLY WINDS OVERNIGHT...QUITE LIGHT. IFR
CONDITIONS WILL CONTINUE THROUGH THE MORNING HOURS ON MONDAY
BEFORE LIFTING TO MVFR OR BETTER. FRONT DROPS SOUTH OF THE REGION
MONDAY AFTERNOON...WITH WINDS SHIFTING TO THE NORTHEAST.
EXTENDED OUTLOOK...BECOMING VFR LATE MON. PERIODS OF MVFR/SHOWERS
TUE/WED. RAIN/IFR THUR. VFR DEVELOPING FRI.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 642 PM SUNDAY...PRESSURE GRADIENT CONTINUES TO WEAKEN WITH
THE DYING COASTAL TROUGH NOW CLOSE TO THE COAST. WINDS AT 41013
HAVE GONE S AROUND 15 KT. ENE 10 TO 15 KT OVER THE NEARSHORE
WATERS WILL CONTINUE WITH WINDS BECOMING LIGHT AND VARIABLE
OVERNIGHT. CLOSER TO DAYBREAK LIGHT OFFSHORE FLOW WILL DEVELOP AS
WEAK HIGH CENTERED OVER GA/SC BECOMES MORE DOMINANT. GRADIENT
REMAINS WEAK AND WESTERLY FLOW LATE IN THE PERIOD WILL CONTINUE TO
RUN 10 KT OR LESS. SEAS 3 TO 5 FT THIS AFTERNOON AND EVENING WILL
CONTINUE THE DOWNWARD TREND OVERNIGHT...FALLING TO 2 TO 4 FT BY
THE END OF THE PERIOD.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...MARINERS SHOULD EXPECT CHANGEABLE WIND
DIRECTIONS THIS PERIOD. WINDS MON MORNING WILL BE WESTERLY...BUT
WITH THE PASSAGE OF A COLD FRONT WILL SHIFT TO N DURING THE
AFTERNOON. NE WINDS WILL BE NEAR SMALL CRAFT ADVISORY LEVELS MON
NIGHT AS A SURGE DEVELOPS IN RESPONSE TO A BUILDING WEDGE OF HIGH
PRESSURE. THE WIND DIRECTION WILL VEER TO EASTERLY DURING TUE AND
THEN SE AND S BY TUE EVE AS HIGH PRESSURE TO OUR NORTH MOVES FURTHER
OFFSHORE. WINDS OVERNIGHT TUE WILL VEER TO SW AHEAD OF A STRONG COLD
FRONT. THE STRONGEST WINDS ARE EXPECTED MON NIGHT...UP TO 20 TO 25
KT. SEAS WILL BE HIGHEST MON NIGHT INTO TUE...UP TO 4 TO 7 FT. SEAS
MAY APPROACH 6 FT TUE NIGHT...MAINLY ACROSS THE NORTHERN OFFSHORE
WATERS.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...SOUTHERLY WINDS WILL CONTINUE THROUGH WED UP
TO 15 TO 20 KTS KEEPING SEAS GENERALLY IN THE 4 TO 6 FT RANGE BUT
WILL INCREASE WED NIGHT INTO THURS AS COLD FRONT MOVES THROUGH. THE
TIGHTENED GRADIENT FLOW WILL PRODUCE WINDS UP NEAR 20 KTS AS THEY
SHIFT MORE ABRUPTLY AROUND FROM SW TO N BEHIND FRONT OVERNIGHT WED.
STRONG CAA AND TIGHTENED GRADIENT WILL KEEP SEAS UP TO 4 TO 7 FT
THURS. THE FRONT WILL LINGER TO THE SOUTH AS HIGH PRESSURE BUILDS
DOWN INTO THE WATERS FROM THE NW. THIS MAY KEEP A PROLONGED PERIOD
OF SCA CONDITIONS IN STRONG NORTHERLY WINDS THROUGH THURS INTO FRI.
WINDS WILL LIGHTEN THROUGH LATE FRI AND BECOME MORE VARIABLE INTO
THE WEEKEND AS HIGH PRESSURE SHIFTS CLOSER OVERHEAD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...RJD
LONG TERM...RGZ
MARINE...III/RJD/RGZ/MJC
AVIATION...DL
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
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 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 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 CHARLESTON WV
659 PM EST SUN MAR 1 2015
.SYNOPSIS...
COLD FRONT CROSSES LATE TONIGHT. HIGH PRESSURE BRINGS DRIER
WEATHER MONDAY INTO MONDAY NIGHT. ANOTHER WARM/COLD FRONT COMBO
TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AREAS OF PCPN CONTINUES ALONG A NEARLY STATIONARY FRONT ALONG
SOUTHEAST OH...EXTENDING SOUTHWEST INTO CENTRAL KY. ABUNDANT
CLOUDS AND LIGHT RAIN WILL PREVAIL THROUGH MIDNIGHT. THEN...A COLD
FRONT WILL PUSH LATER OVERNIGHT TAKING MOST PCPN EAST OF THE AREA
BY EARLY MONDAY MORNING. LOWERED POPS ACROSS THE SOUTHERN COAL
FIELDS UNTIL THE COLD FRONT PASSES LATE OVERNIGHT.
TEMPERATURES REMAIN ABOVE FREEZING AT LEAST THROUGH MIDNIGHT OVER
THE HIGHER ELEVATIONS OF OUR NORTHEAST MOUNTAINS. THEREFORE...THE
THREAT FOR FREEZING RAIN HAS DIMINISHED AND THE ADVISORY FOR
POCAHONTAS COUNTY WILL BE ALLOW TO EXPIRE AT 7 PM.
PREVIOUS DISCUSSION BELOW...
THE WIDESPREAD PRECIPITATION WILL BE CUT OFF FOR THE MOST PART
TONIGHT AS A COLD FRONT CROSSES THE AREA. MODELS DO SUGGEST ONE
LAST W-E DAGGER OF PRECIPITATION BEHIND THE FRONT TONIGHT...AS ONE
LAST TRAILING UPPER LEVEL S/W TROUGH MOVES THROUGH. CONSIDERED
EXTENDING THE PERRY-MORGAN ADVISORY FOR THIS BUT THERE SHOULD NOT BE
A FREEZING RAIN THREAT AND ADDITIONAL SNOW AMOUNTS SHOULD BE AN INCH
OR LESS.
OTHERWISE UPSLOPE FLOW SUPPORTS SNOW SHOWERS IN THE MOUNTAINS
OVERNIGHT INTO MON WITH UP TO AN INCH OR SO THERE. LOW LEVEL
MOISTURE WILL KEEP PLENTY OF CLOUDS AROUND MON...A MORNING CU
PROCESS IN THE MORNING...MIXING UP INTO A STRATOCU DECK THAT SHOULD
START TO BREAK UP IN THE AFTERNOON. IT SHOULD CLEAR FURTHER AS HIGH
PRESSURE BUILDS INTO THE AREA AT THE END.
USED HRRR AND THEN NAM/MET FOR TEMPS...A BIT SHARPER BAROCLINIC ZONE
TONIGHT AND A BIT LOWER ON HIGHS MON COMPARED WITH PREVIOUS WITH
TEMPERATURES NOT RISING MUCH UNTIL AFTER 15Z.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
A PROLONGED WET SYSTEM APPROACHES THE FORECAST AREA ON TUESDAY AND
ULTIMATELY DECIDES TO TAKE ITS TIME MOVING THROUGH THE WILD AND
WONDERFUL STATE. THE GFS IS THE MOST PROGRESSIVE OF THE BUNCH
WHILE THE EURO AND NAM ARE SIMILAR KEEPING A FIRE HOSE POINTED AT
US FOR AT LEAST 24 HOURS. THIS FORECAST MORE CLOSELY FOLLOWS THE
WETTER/SLOWER MODELS. ITS WORTH MENTIONING THAT THERE IS SOME
UNCERTAINTY IN THE LOCATION IN WHICH THE HEAVIEST RAIN FALLS...SO
THE QPF IS LIKELY BLENDED OVER A LARGER PORTION OF THE AREA THAN
WHAT WILL ACTUALLY HAPPEN.
THE MOISTURE TAP FOR THIS SYSTEM EXTENDS ALL THE WAY BACK TO THE
BAJA PENINSULA...SO REGARDLESS THIS WILL BE A RATHER JUICY SYSTEM
WITH ATMOSPHERIC RIVER POTENTIAL. A 70+ KT SWLY LLJ DEVELOPS
ENHANCING LOW LEVEL MOISTURE ADVECTION. ALL SAID AND DONE 2 INCHES
OF QPF SOUNDS REASONABLE FOR MOST PLACES...THIS COUPLED WITH
SNOWPACK MELTING IN THE WARMER TEMPERATURES THAT WE WILL
EXPERIENCE WILL CAUSE A SCENARIO WHERE FLOODING IS A LARGE
CONCERN.
ALSO OF CONCERN IS THE STRONGER WINDS IN THE MOUNTAINS...DEPENDING
ON HOW MUCH SNOW MELT OCCURS AND HOW THAWED AND SATURATED THE GROUNDS
ARE THIS COULD BE ANOTHER POTENTIAL HAZARD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
FRONTAL BOUNDARY WILL BE EAST OF THE AREA THURSDAY MORNING...WITH
COLDER AIR FILTERING INTO THE REGION...AND ANY LINGERING
PRECIPITATION CHANGING OVER TO SNOW. EXPECTING LIGHT ACCUMULATIONS
EARLY THURSDAY...PARTICULARLY ACROSS THE HIGHER TERRAIN COUNTIES.
HIGH PRESSURE WILL THEN BUILD IN BEHIND THE DEPARTING FRONT...FOR
CONTINUED COOL...BUT DRY CONDITIONS.
&&
.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
WIDESPREAD IFR CEILINGS EXPECTED ACROSS MOST OF THE WESTERN SITES
INCLUDING CKB TO THE NORTH WHILE ABUNDANT LOW LEVEL MOISTURE
ASSOCIATED WITH A NEARLY STATIONARY FRONTAL BOUNDARY REMAINS
ACROSS SOUTHEAST OH...AND AREAS OF MOSTLY RAIN MOVE EAST NORTHEAST
ACROSS THE NORTHERN HALF OF OUR CWA.
MVFR CONDITIONS TO REMAIN AT BKW AND EKN...BUT EKN COULD SEE A
REDUCTION IN CEILINGS TO IFR AFTER 02Z DUE TO INCOMING PCPN.
VSBYS WILL IMPROVE BEHIND THE COLD FRONT EXPECTED TO PASS LATE
OVERNIGHT TONIGHT. THIS FRONT ROLLS THROUGH W TO E BETWEEN 06Z AND
09Z.
MON WILL BRING IMPROVING CONDITIONS WITH MOUNTAIN SNOW SHOWERS
ENDING BY LATE MORNING...AND MORNING CU THAT WILL EVOLVE INTO AN
AFTERNOON STRATOCU DECK. THESE CLOUD HEIGHTS WILL RISE...BUT MAY
REMAIN BELOW 3KFT...BUT START TO BREAK UP IN THE LOWLANDS IN THE
AFTERNOON...AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE NW.
LIGHT S SFC FLOW WILL BECOME MODERATE W OVERNIGHT TONIGHT AND
THEN MODERATE NW FOR MON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: GUIDANCE SHOW WIDESPREAD IFR AT MOST SITES
TONIGHT. CONDITIONS COULD IMPROVE EARLIER THAN ANTICIPATED.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06
CRW CONSISTENCY L L L L L L L L H H H H
HTS CONSISTENCY M M M M L L L H H H H H
BKW CONSISTENCY L L L L L L H M L L L L
EKN CONSISTENCY L L L L L L L L L M M M
PKB CONSISTENCY H H H H L M M H H H H H
CKB CONSISTENCY L L L L L L L L H H H H
AFTER 00Z TUESDAY...
IFR POSSIBLE IN RAIN SHOWERS TUESDAY INTO WEDNESDAY...AND PERHAPS
SNOW AT THE END WEDNESDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/SL/30
NEAR TERM...TRM
SHORT TERM...JW
LONG TERM...SL
AVIATION...ARJ
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 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
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 STATE COLLEGE PA
726 PM EST SUN MAR 1 2015
.SYNOPSIS...
WEAK LOW PRESSURE AND A DISTURBANCE AT UPPER LEVELS OF THE
ATMOSPHERE WILL TRACK NORTHEAST UP THE OHIO VALLEY AND CROSS
PENNSYLVANIA THIS EVENING. THIS PAIR OF WEATHER FEATURES WILL
BRING PERIODS OF LIGHT TO BRIEFLY MODERATE SNOW...THEN SOME MIXED
PRECIPITATION TO SOUTH-CENTRAL PA AND THE LOWER SUSQ VALLEY INTO
THIS EVENING. HIGH PRESSURE WILL BRING FAIR AND COLD CONDITIONS
TO REGION MONDAY AND MONDAY NIGHT. A STRONGER AREA OF LOW PRESSURE
WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY AND EARLY
WEDNESDAY...BRINGING MAINLY RAIN TO THE AREA. COLDER TEMPERATURES
WILL FOLLOW FOR THE LATER PART OF THE WEEK.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
DID ADJUST THE AREA OF FREEZING RAIN SOME...TO FIT IN WITH THE
CURRENT OBS.
EARLIER DISCUSSION BELOW.
BRIGHT BANDING AND ELEVATED CCS SHOWING THE PRECIP TRANSITION ZONE
WELL AS IT TRANSLATES NORTH OF THE MD BORDER INTO THE SOUTH
CENTRAL MOUNTAINS AND FAR LOWER SUSQ RIVER VALLEY. 3" OF NEW SNOW
O.G. NEAR GREENCASTLE FROM A TRUSTED WEATHER SPOTTER AND NOW
FREEZING RAIN OCCURRING AT 27F. SLEET HAD BRIEFLY MIXED IN EARLIER
ACROSS SOUTHERN YORK. A GENERAL 2-4" IS EXPECTED SOUTH OF
INTERSTATE 80 AND EAST OF ROUTE 99...WITH THE ADDITIONAL
CHANGEOVER TO ICE ACROSS SOUTHERN PORTIONS OF THE SOUTH CENTRAL
MOUNTAINS AND LOWER SUSQ RIVER VALLEY ADDING ANOTHER .1 TO .15"
OF ICE ON TOP IN THOSE AREAS.
OVERALL SCENARIO PLAYING OUT WITH WITH PERIODS OF SNOW (OF
VARYING INTENSITY) CONTINUING TO INCREASE IN AREAL COVERAGE THIS
AFTERNOON FROM SOUTHWEST TO NORTHEAST. STRONG VERTICAL SHEAR
EVIDENT ACROSS THE REGION WITH 150+ KT 250 MB JET SLICING ENE
ACROSS THE NORTHERN OHIO VALLEY AND EASTERN GLAKS. BOUNDARY LAYER
CONVERGENCE AND FORCING IS BEST ACROSS SOUTHERN PA THIS AFTERNOON
AND EVENING...IN VICINITY OF 850 MB JET FEATURES...FIRST OF WHICH
HAS SPAWNED A FEW HOURS OF MODERATE TO LOCALLY HEAVY PRECIP RATES
FROM NORTHERN MARYLAND INTO MY SOUTHEAST COUNTIES. THIS IS PROGGED
TO EXIT EASTWARD BY LATE AFTERNOON/EVENING BEFORE A MORE BROAD
AREA OF BOUNDARY LAYER CONVERGENCE DEVELOPS AS THE UPPER TROF
NEARS.
12Z RAP HANDLED THE ONGOING CHANGEOVER QUITE WELL FOR AREAS ALONG
THE MD BORDER...AND EXPECT MDT TO BE CHANGING OVER IN THE NEXT
HOUR OR TWO...STARTING WITH A MIXTURE OF SLEET AND THEN MAINLY
LIGHT FREEZING RAIN AFTERWARD WITH AROUND 0.10 INCH QPF. WILL
CONTINUE TO RIDE WITH A BLEND OF CURRENT AND UPCOMING HIGH RES
GUIDANCE FOR ICE ACROSS OUR SRN ZONES...UNLESS WE SEE REASON TO
SIGNIFICANTLY DEVIATE.
WE WILL CONTINUE TO HOLD OFF ON ANY UPGRADES TO WINTER STORM/ICE
STORM WARNINGS AT THIS TIME...AS AMOUNTS ARE EXPECTED TO REMAIN IN
THE .1 TO .15" RANGE OVERALL...WITH SOME APPROACHING .20" ON TOP
OF THE 2-4" OF SNOW ACCUM.
ELSEWHERE...GOOD CONSISTENCY OF PAST SEVERAL MODEL/ENSEMBLE CYCLES
CONTINUES THIS AFTERNOON WITH RESPECT TO PTYPE...WITH BULK OF
THIS WINTRY EVENT FALLING AS SNOW TO THE NORTH OF THE RT22/322
CORRIDOR IN CENTRAL PENN. AMOUNTS AND DISTRIBUTION HAVE BEEN
TRICKY GIVEN THE LACK OF FORCING FARTHER NORTH...BUT IN GENERAL IT
APPEARS THAT 2-4" WILL BE COMMON FOR MOST...WHILE BETTER UPSLOPE
AND MOISTURE TRANSPORT INTO THE WEST CENTRAL MOUNTAINS AND LAUREL
HIGHLANDS PRODUCE MAX AMOUNTS THERE...GENERALLY UP TO 6" BUT WE
COULD SEE SOME SPOT AMOUNTS COME IN HIGHER.
TEMPS WILL WILL CONTINUE TO SLOWLY RISE TO A LATE DAY HIGH IN THE
UPPER 20S ACROSS THE CENTRAL AND NORTHERN MTNS...AND LOWER TO MID
30S ACROSS THE LOWER SUSQ VALLEY AND LAUREL HIGHLANDS RESPECTIVELY.
WINDS WILL BE SOUTH TO SW AT 5-8 KTS IN MOST PLACES THROUGH TODAY.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH MONDAY NIGHT/...
PRECIP LOOKS TO TAPER OFF IN ALL AREAS DURING THE LATE EVENING
THROUGH VERY EARLY MORNING HOURS OF MONDAY.
LOW TEMPS TONIGHT /UNDER PLENTY OF LINGERING AND MORE
SHALLOW...WARMER LOWER CLOUDS/ WILL RANGE FROM NEAR 20 DEG IN THE
NORTH TO 30F IN ACROSS THE SOUTH.
BLUSTERY AND COLDER CONDITIONS WILL MAKE A RETURN ON MONDAY AS
SYSTEM NUMBER ONE SLIDES OFF TO OUR EAST. OTHER THAN THE USUAL
POST FRONTAL SNOWS SHOWERS...FAVORING WESTERN HIGHER
ELEVATIONS...CONDITIONS WILL BE GRADUALLY IMPROVING OVERALL
THROUGHOUT THE DAY.
DID NOT MAKE ANY LARGE CHANGES TO MONDAY.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE AND ITS FAIR WEATHER AND LIGHT WIND WILL BE SHORT
LIVED MONDAY NIGHT INTO TUESDAY WHEN THE NEXT IN THE SERIES OF
STORM SYSTEMS IS SLATED TO ENTER THE LOCAL WEATHER SCENE. THIS ONE
PROMISES MORE OF A MESSY OUTCOME AS IT SHOULD TRACK WELL TO OUR
NW...MEANING WARM AIR EVENTUALLY INVADING THE REGION...WITH A SNOW
TO SLEET/FREEZING RAIN AND EVEN RAIN SCENARIO.
SNOW AMOUNTS DO NOT LOOK TO BE THE BIGGEST PART OF THE MIDWEEK
STORM AS WE ARE PROGGED TO WARM ALOFT RATHER QUICKLY. WITH A DEEP
SNOW PACK AND A LOT OF COLD AIR TO DISPLACE...WE WILL LIKELY SEE
A PERIOD OF ICING BEFORE WARM AIR EVENTUALLY CHANGES EVERYTHING TO
RAIN TUESDAY NIGHT INTO WEDNESDAY.
MAIN CHANGE WAS TO ADJUST POPS SOME TUE INTO TUE NIGHT.
THINK MAIN TYPE OF PCPN WILL BE RAIN TUE NIGHT INTO WED. DID
PUT SMALL AMTS OF .01 ICE ACROSS THE AREA...GIVEN THAT OBJECT
TEMPS WILL STILL LIKELY BE COLD. TEMPERATURES TUE NIGHT MAY
DROP A LITTLE...BEFORE COMING BACK UP LATE.
RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS WITH THE PASSAGE OF
THE TRAILING COLD FRONT EARLY WEDNESDAY.
FOR WED...TOOK SNOW SHOWERS OUT OF THE NW. TIGHT THICKNESS PATTERN
ACROSS THE AREA...SUPPORT A LARGE TEMPERATURE GRADIENT FROM NW PA
TO SE PA. THERE COULD BE A FEW SHOW SHOWERS ACROSS THE FAR
NW...BUT IT LOOKS LIKE MAINLY NW OF OUR AREA. LEFT POPS UP...THINK
FRONT WILL BE SLOW TO MOVE OUT.
A TREND TOWARD COLDER WEATHER AGAIN LATER IN THE WEEK...GIVEN
SPLIT FLOW.
PUSH OF ARCTIC AIR WILL BRING TEMPS AND POPS BACK WELL BELOW
NORMAL FOR LATE THURSDAY INTO FRIDAY. THE ONLY GOOD THING SEEMS TO
BE EACH ARCTIC SHOT IS A LITTLE LESS POTENT THAN THE LAST AS WE
LEAVE THE RECORD COLD OF FEBRUARY BEHIND.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
ONE LAST BAND OF HEAVIER SNOW ASSOCIATED WITH COLD FRONT TRACKING
THROUGH CENTRAL PENNSYLVANIA FROM KIPT TO KUNV TO KAOO AT 00Z.
WHAT REMAINS OF THE LIGHT PRECIPITATION OVER THE SOUTHEAST
SECTIONS CONTINUES TO BE IN THE FORM OF LIGHT FZRA OR PL. KJST
HAS CREPT INTO THE WARM SECTOR...AND IS NOW 34 DEGREES WITH PLAIN
RAIN.
EXPECT PRECIPITATION TO LIGHTEN CONSIDERABLY FROM WEST TO EAST OVER
THE NEXT 3 TO 6 HOURS. THIS WILL INTRODUCE A SLOW IMPROVEMENT IN
FLYING CONDITIONS OVERNIGHT...BUT MANY LOCATIONS WILL REMAIN IFR
TO MVFR OVERNIGHT.
CONDITIONS WILL SLOWLY IMPROVE ON MONDAY...BUT EXPECT RESTRICTIONS
TO LINGER IN THE WESTERN AND NORTHERN HIGHER TERRAIN ON COLD NORTHWEST
WINDS AND TYPICAL OROGRAPHIC SNOW SHOWERS.
BRIEF RESPITE LATER MONDAY INTO EARLY TUESDAY...BEFORE THE NEXT
SYSTEM PUSHES ANOTHER ROUND OF PRECIPITATION AND REDUCED FLYING
CONDITIONS INTO THE AREA LATER TUESDAY AND WEDNESDAY.
OUTLOOK...
TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE.
WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
FRI...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 2 AM EST MONDAY FOR PAZ019-027-
028-037-041-042-045-046-049>053-056>059-063>066.
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR PAZ004>006-
010>012-017-018-024-033.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR
PAZ025-026-034>036.
&&
$$
SYNOPSIS...DEVOIR/LAMBERT/MARTIN
NEAR TERM...DEVOIR/LAMBERT/MARTIN
SHORT TERM...DEVOIR/LAMBERT/MARTIN
LONG TERM...LA CORTE/LAMBERT/MARTIN
AVIATION...JUNG
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
851 PM CST SUN MAR 1 2015
.UPDATE...
TEMPERATURES HAVE WARMED ABOVE FREEZING ACROSS ALL OF NORTH TEXAS
THIS EVENING AND ADDITIONAL FREEZING PRECIPITATION IS NOT EXPECTED
DURING THE OVERNIGHT HOURS. IT WILL CONTINUE TO BE CLOUDY THOUGH
AND THERE WILL BE SOME SCATTERED LIGHT RAIN OR DRIZZLE THROUGH THE
NIGHT. 00Z FWD SOUNDING WAS COMPLETELY SATURATED FROM JUST ABOVE
THE SURFACE TO ALMOST 750MB. WEAK WARM ADVECTION ABOVE THE COLD
SURFACE LAYER WILL CONTINUE TO SUPPORT THE CLOUDS AND LIGHT
PRECIPITATION. TEMPERATURES WILL REMAIN GENERALLY STEADY THROUGH
THE OVERNIGHT HOURS. NO SIGNIFICANT CHANGES TO THE CURRENT
FORECAST OTHER THAN TO ADJUST HOURLY TEMPERATURES AND LOWER POPS A
BIT THROUGH THE OVERNIGHT HOURS AS PRECIPITATION IS EXPECTED TO BE
SPOTTY IN NATURE.
DUNN
&&
.AVIATION...
/ISSUED 608 PM CST SUN MAR 1 2015/
/00Z TAFS/
CHALLENGES CONTINUE WITH CIGS/VSBY CATEGORIES AND MORE -RA/-DZ
ARRIVING OVERNIGHT...AS ANOTHER MID LEVEL IMPULSE ARRIVES LATER
THIS EVENING AND ASSOCIATED WAA ABOVE THE FRONTAL INVERSION
OCCURS. WILL PREVAIL IFR CIGS...WITH MVFR VSBYS AND -RA OR -DZ
ARRIVING BETWEEN MID EVENING AND MIDNIGHT...THEN CONTINUING MONDAY
MORNING WITH CIGS FALLING INTO LIFR...THOUGH CONFIDENCE IS NOT
HIGH ATTM DUE TO NORTH WINDS REMAINING UP AROUND 10 KTS OR
SLIGHTLY HIGHER. THESE WIND SPEEDS SHOULD KEEP THE NEAR SURFACE
LAYER A LITTLE MORE MIXED THAN WITH PREVIOUS NIGHTS.
MOS GUIDANCES CONTINUE TO STRUGGLE ON OVERALL CONDITIONS AND HAVE
BASICALLY TRASHED THEM AND FOLLOWED THE NAM12 BUFR AND RUC BAK40
SOUNDINGS CLOSELY FOR THIS FORECAST...AS THEY APPEAR MORE REASONABLE
ON TRENDS. EXPECT CONDITIONS TO SLOWLY IMPROVE AND RISE BACK INTO
IFR FOR A WHILE MONDAY AFTERNOON AS SURFACE TEMPERATURES WARM.
SURFACE RIDGE SHOULD SHIFT E/SE OF THE AREA FINALLY BY MONDAY
EVENING AND WE COULD SEE BETTER CHANCES FOR FOG AND LIFR
CONDITIONS MONDAY NIGHT.
05/
&&
.PREV DISCUSSION... /ISSUED 355 PM CST SUN MAR 1 2015/
THE WEATHER PATTERN ACROSS NORTH TEXAS IS NOT EXPECTED TO CHANGE
MUCH TONIGHT THROUGH MONDAY WITH SHALLOW...COLD AIR REMAINING AT
THE SURFACE AND CONTINUED WARM AIR ADVECTION ABOVE THE ARCTIC AIR.
THIS PATTERN WILL RESULT IN CONTINUED AREAS OF LOW CLOUDS AND
DRIZZLE/LIGHT RAIN TONIGHT THROUGH MONDAY. THE ONLY GOOD NEWS IS
THAT THERE IS NOT MUCH...IF ANY...ADDITIONAL COLD AIR ADVECTION
NEAR THE SURFACE ACROSS THE REGION AND TEMPERATURES SHOULD REMAIN
ABOVE FREEZING OVERNIGHT. THEREFORE...FREEZING DRIZZLE IS NOT
EXPECTED TONIGHT. THE ONLY EXCEPTION MAY BE ACROSS THE EXTREME
NORTHWEST ZONES WHERE TEMPS MAY COOL BACK DOWN TO 32 DEGREES FOR A
FEW HOURS AFTER DARK. EVEN IF TEMPS DO COOL TO 32 DEGREES NO
TRAVEL IMPACTS ARE EXPECTED.
MONDAY WILL SEE A SLOW WARM UP AS MUCH OF THE SNOW COVER FINALLY
MELTS AND SOME WEAK SURFACE WARM AIR ADVECTION BEGINS AS WINDS
TURN TO THE EAST. THE WIND SHIFT WILL BE IN RESPONSE TO
DEVELOPING SURFACE LOW PRESSURE ACROSS THE CENTRAL ROCKIES.
SURFACE WARM AIR ADVECTION WILL BEGIN IN EARNEST MONDAY NIGHT AS
THE DEEPENING SURFACE LOW MOVES ONTO THE CENTRAL HIGH PLAINS AND
THE GULF FULLY OPENS UP. THIS WILL RESULT IN MUCH WARMER OVERNIGHT
LOWS MONDAY NIGHT THAN WE HAVE SEEN THE PAST SEVERAL DAYS AND EVEN
THE DEVELOPMENT OF SOME FOG ALONG WITH DRIZZLE/LIGHT RAIN.
TUESDAY WILL BE THE WARMEST DAY OF THE WEEK EVEN THOUGH SKIES WILL
BE MOSTLY CLOUDY. EXPECT AFTERNOON HIGHS TUESDAY IN THE UPPER 60S
TO LOWER 70S. SOME MIDDLE 70S ARE EVEN POSSIBLE IN THE WEST DUE TO
SOUTHWESTERLY WINDS BEHIND A PASSING PREFRONTAL TROUGH. SHOWERS
AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE TUESDAY AS A DEEP
UPPER TROUGH MOVES INLAND FROM THE PACIFIC. PREVIOUS MODEL RUNS
WERE INDICATING SOME DECENT INSTABILITY AND WIND SHEAR TUESDAY
AFTERNOON WITH THE POTENTIAL FOR STRONG THUNDERSTORMS. ALL MODELS
HAVE BACKED OFF ON THE AMOUNT OF MID LEVEL INSTABILITY THAT WILL
BE AVAILABLE SO WILL KEEP THUNDERSTORM COVERAGE ISOLATED WITH THE
EXCEPTION OF THE NORTHEAST ZONES WHERE CAPE SHOULD BE A BIT
HIGHER.
A COLD FRONT IS PROGGED TO MOVE ACROSS NORTH TEXAS TUESDAY NIGHT
AND BRING ADDITIONAL FOCUS FOR SHOWERS AND ISOLATED THUNDERSTORMS.
THE FRONT WILL ALSO BRING SHARPLY FALLING TEMPERATURES ALONG WITH
INCREASING NORTH WINDS. THINGS SHOULD GET A BIT MORE INTERESTING
ON WEDNESDAY AS THE COLD AIR DEEPENS ACROSS THE REGION AND LARGE
SCALE LIFT INCREASES. WE EXPECT A MIX OF RAIN AND SLEET IN THE
NORTHWEST ZONES AFTER SUNRISE WEDNESDAY WITH A MIX OF
PRECIPITATION MOVING INTO THE CENTRAL ZONES BY MIDDAY.
TEMPERATURES WILL MOST LIKELY FALL TO NEAR FREEZING ACROSS THE
NORTHWEST HALF OF THE REGION BY LATE AFTERNOON WEDNESDAY AND
ACROSS ALL ZONES SHORTLY AFTER SUNSET. PRECIPITATION SHOULD
TRANSITION TO A MIX OF SLEET AND SNOW FROM NORTH TO SOUTH
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT AS THE WARM NOSE
DISAPPEARS AND THE DENDRITIC GROWTH ZONES BEGINS TO SATURATE.
IT IS MUCH TOO EARLY TO ASSESS THE AMOUNT OF WINTER PRECIPITATION
FOR THIS MID WEEK SYSTEM OR THE POTENTIAL IMPACTS. WHAT WE DO
KNOW IS THAT THE GFS AND ECMWF SOLUTIONS ARE COMING A BIT MORE IN
ALIGNMENT WITH REGARDS TO THE TIMING OF THE BEST LIFT...THE
STRENGTH OF THE FRONT(IE. HOW COLD IT WILL GET) AND THE AMOUNT OF
MOISTURE THAT WILL BE AVAILABLE. IT IS MUCH TO EARLY TOO PUT A
SLEET/SNOW AMOUNT WITH ANY DEGREE OF CONFIDENCE SINCE
ACCUMULATIONS WILL LARGELY HINGE ON JUST HOW COLD IT WILL GET WHEN
THE HEAVIEST PRECIP OCCURS. ONE THING THAT IS A BIT CONCERNING IS
THAT THE MODELS DO TEND TO UNDERESTIMATE SHALLOW ARCTIC AIR AND
FOR THAT REASON I HAVE UNDERCUT MOS GUIDANCE A FEW DEGREES FOR
LOWS WEDNESDAY NIGHT. WE WILL NOT OUTLOOK THIS POTENTIAL STORM
YET BUT AWAIT MORE RUN TO RUN MODEL CONSENSUS. WE WILL CONTINUE TO
ADVERTISE THE POTENTIAL FOR ANOTHER WINTER EVENT IN BOTH THE
HAZARDOUS WEATHER OUTLOOK AND GRAPHICALLY.
THE LOW LEVELS OF THE ATMOSPHERE SHOULD BEGIN TO DRY OUT ON
THURSDAY AS THE COLD AIR DEEPENS BUT WE WILL LINGER SOME LIGHT
WINTER PRECIP OR A MIX IN THE SOUTHERN ZONES THURSDAY MORNING.
MODELS CONTINUE TO INDICATE THAT THE LOW LEVEL TEMPERATURES WILL
MODIFY SOME ON THURSDAY WITH THE RETURN OF THE SUN. OUR FORECAST
MAY BE TOO WARM THURSDAY IF THE FEED OF UPPER LEVEL MOISTURE
ASSOCIATED WITH A CUT OFF LOW NEAR BAJA KEEPS SKIES CLOUDY.
ALSO...WILL HAVE TO CONSIDER THAT ANY TYPE OF SNOW COVER WOULD
ALSO AFFECT HIGH TEMPERATURES THURSDAY. EVEN IF TEMPS DO WARM
ABOVE FREEZING THURSDAY...THEY WILL MOSTLY LIKELY FALL BACK INTO
THE 20S THURSDAY NIGHT WHICH WOULD REFREEZE ANY RESIDUAL WATER.
THE EXTENDED MODELS KEEP THE GULF SHUT OFF THURSDAY NIGHT THROUGH
SUNDAY WHICH SHOULD KEEP TEMPERATURES BELOW NORMAL WITH MINIMAL
RAIN CHANCES.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 34 44 44 70 42 / 30 40 40 40 60
WACO, TX 36 45 45 73 48 / 30 30 30 30 60
PARIS, TX 36 45 42 68 41 / 40 50 50 60 60
DENTON, TX 33 42 42 71 38 / 30 30 40 40 60
MCKINNEY, TX 33 42 42 69 40 / 40 40 50 40 60
DALLAS, TX 34 44 44 70 42 / 30 40 50 40 60
TERRELL, TX 35 44 44 69 44 / 40 40 40 40 60
CORSICANA, TX 37 46 46 71 48 / 40 40 30 40 60
TEMPLE, TX 36 45 45 71 50 / 30 30 30 30 50
MINERAL WELLS, TX 33 39 39 70 38 / 20 20 40 30 60
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
608 PM CST SUN MAR 1 2015
.AVIATION...
/00Z TAFS/
CHALLENGES CONTINUE WITH CIGS/VSBY CATEGORIES AND MORE -RA/-DZ
ARRIVING OVERNIGHT...AS ANOTHER MID LEVEL IMPULSE ARRIVES LATER
THIS EVENING AND ASSOCIATED WAA ABOVE THE FRONTAL INVERSION
OCCURS. WILL PREVAIL IFR CIGS...WITH MVFR VSBYS AND -RA OR -DZ
ARRIVING BETWEEN MID EVENING AND MIDNIGHT...THEN CONTINUING MONDAY
MORNING WITH CIGS FALLING INTO LIFR...THOUGH CONFIDENCE IS NOT
HIGH ATTM DUE TO NORTH WINDS REMAINING UP AROUND 10 KTS OR
SLIGHTLY HIGHER. THESE WIND SPEEDS SHOULD KEEP THE NEAR SURFACE
LAYER A LITTLE MORE MIXED THAN WITH PREVIOUS NIGHTS.
MOS GUIDANCES CONTINUE TO STRUGGLE ON OVERALL CONDITIONS AND HAVE
BASICALLY TRASHED THEM AND FOLLOWED THE NAM12 BUFR AND RUC BAK40
SOUNDINGS CLOSELY FOR THIS FORECAST...AS THEY APPEAR MORE REASONABLE
ON TRENDS. EXPECT CONDITIONS TO SLOWLY IMPROVE AND RISE BACK INTO
IFR FOR A WHILE MONDAY AFTERNOON AS SURFACE TEMPERATURES WARM.
SURFACE RIDGE SHOULD SHIFT E/SE OF THE AREA FINALLY BY MONDAY
EVENING AND WE COULD SEE BETTER CHANCES FOR FOG AND LIFR
CONDITIONS MONDAY NIGHT.
05/
&&
.PREV DISCUSSION... /ISSUED 355 PM CST SUN MAR 1 2015/
THE WEATHER PATTERN ACROSS NORTH TEXAS IS NOT EXPECTED TO CHANGE
MUCH TONIGHT THROUGH MONDAY WITH SHALLOW...COLD AIR REMAINING AT
THE SURFACE AND CONTINUED WARM AIR ADVECTION ABOVE THE ARCTIC AIR.
THIS PATTERN WILL RESULT IN CONTINUED AREAS OF LOW CLOUDS AND
DRIZZLE/LIGHT RAIN TONIGHT THROUGH MONDAY. THE ONLY GOOD NEWS IS
THAT THERE IS NOT MUCH...IF ANY...ADDITIONAL COLD AIR ADVECTION
NEAR THE SURFACE ACROSS THE REGION AND TEMPERATURES SHOULD REMAIN
ABOVE FREEZING OVERNIGHT. THEREFORE...FREEZING DRIZZLE IS NOT
EXPECTED TONIGHT. THE ONLY EXCEPTION MAY BE ACROSS THE EXTREME
NORTHWEST ZONES WHERE TEMPS MAY COOL BACK DOWN TO 32 DEGREES FOR A
FEW HOURS AFTER DARK. EVEN IF TEMPS DO COOL TO 32 DEGREES NO
TRAVEL IMPACTS ARE EXPECTED.
MONDAY WILL SEE A SLOW WARM UP AS MUCH OF THE SNOW COVER FINALLY
MELTS AND SOME WEAK SURFACE WARM AIR ADVECTION BEGINS AS WINDS
TURN TO THE EAST. THE WIND SHIFT WILL BE IN RESPONSE TO
DEVELOPING SURFACE LOW PRESSURE ACROSS THE CENTRAL ROCKIES.
SURFACE WARM AIR ADVECTION WILL BEGIN IN EARNEST MONDAY NIGHT AS
THE DEEPENING SURFACE LOW MOVES ONTO THE CENTRAL HIGH PLAINS AND
THE GULF FULLY OPENS UP. THIS WILL RESULT IN MUCH WARMER OVERNIGHT
LOWS MONDAY NIGHT THAN WE HAVE SEEN THE PAST SEVERAL DAYS AND EVEN
THE DEVELOPMENT OF SOME FOG ALONG WITH DRIZZLE/LIGHT RAIN.
TUESDAY WILL BE THE WARMEST DAY OF THE WEEK EVEN THOUGH SKIES WILL
BE MOSTLY CLOUDY. EXPECT AFTERNOON HIGHS TUESDAY IN THE UPPER 60S
TO LOWER 70S. SOME MIDDLE 70S ARE EVEN POSSIBLE IN THE WEST DUE TO
SOUTHWESTERLY WINDS BEHIND A PASSING PREFRONTAL TROUGH. SHOWERS
AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE TUESDAY AS A DEEP
UPPER TROUGH MOVES INLAND FROM THE PACIFIC. PREVIOUS MODEL RUNS
WERE INDICATING SOME DECENT INSTABILITY AND WIND SHEAR TUESDAY
AFTERNOON WITH THE POTENTIAL FOR STRONG THUNDERSTORMS. ALL MODELS
HAVE BACKED OFF ON THE AMOUNT OF MID LEVEL INSTABILITY THAT WILL
BE AVAILABLE SO WILL KEEP THUNDERSTORM COVERAGE ISOLATED WITH THE
EXCEPTION OF THE NORTHEAST ZONES WHERE CAPE SHOULD BE A BIT
HIGHER.
A COLD FRONT IS PROGGED TO MOVE ACROSS NORTH TEXAS TUESDAY NIGHT
AND BRING ADDITIONAL FOCUS FOR SHOWERS AND ISOLATED THUNDERSTORMS.
THE FRONT WILL ALSO BRING SHARPLY FALLING TEMPERATURES ALONG WITH
INCREASING NORTH WINDS. THINGS SHOULD GET A BIT MORE INTERESTING
ON WEDNESDAY AS THE COLD AIR DEEPENS ACROSS THE REGION AND LARGE
SCALE LIFT INCREASES. WE EXPECT A MIX OF RAIN AND SLEET IN THE
NORTHWEST ZONES AFTER SUNRISE WEDNESDAY WITH A MIX OF
PRECIPITATION MOVING INTO THE CENTRAL ZONES BY MIDDAY.
TEMPERATURES WILL MOST LIKELY FALL TO NEAR FREEZING ACROSS THE
NORTHWEST HALF OF THE REGION BY LATE AFTERNOON WEDNESDAY AND
ACROSS ALL ZONES SHORTLY AFTER SUNSET. PRECIPITATION SHOULD
TRANSITION TO A MIX OF SLEET AND SNOW FROM NORTH TO SOUTH
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT AS THE WARM NOSE
DISAPPEARS AND THE DENDRITIC GROWTH ZONES BEGINS TO SATURATE.
IT IS MUCH TOO EARLY TO ASSESS THE AMOUNT OF WINTER PRECIPITATION
FOR THIS MID WEEK SYSTEM OR THE POTENTIAL IMPACTS. WHAT WE DO
KNOW IS THAT THE GFS AND ECMWF SOLUTIONS ARE COMING A BIT MORE IN
ALIGNMENT WITH REGARDS TO THE TIMING OF THE BEST LIFT...THE
STRENGTH OF THE FRONT(IE. HOW COLD IT WILL GET) AND THE AMOUNT OF
MOISTURE THAT WILL BE AVAILABLE. IT IS MUCH TO EARLY TOO PUT A
SLEET/SNOW AMOUNT WITH ANY DEGREE OF CONFIDENCE SINCE
ACCUMULATIONS WILL LARGELY HINGE ON JUST HOW COLD IT WILL GET WHEN
THE HEAVIEST PRECIP OCCURS. ONE THING THAT IS A BIT CONCERNING IS
THAT THE MODELS DO TEND TO UNDERESTIMATE SHALLOW ARCTIC AIR AND
FOR THAT REASON I HAVE UNDERCUT MOS GUIDANCE A FEW DEGREES FOR
LOWS WEDNESDAY NIGHT. WE WILL NOT OUTLOOK THIS POTENTIAL STORM
YET BUT AWAIT MORE RUN TO RUN MODEL CONSENSUS. WE WILL CONTINUE TO
ADVERTISE THE POTENTIAL FOR ANOTHER WINTER EVENT IN BOTH THE
HAZARDOUS WEATHER OUTLOOK AND GRAPHICALLY.
THE LOW LEVELS OF THE ATMOSPHERE SHOULD BEGIN TO DRY OUT ON
THURSDAY AS THE COLD AIR DEEPENS BUT WE WILL LINGER SOME LIGHT
WINTER PRECIP OR A MIX IN THE SOUTHERN ZONES THURSDAY MORNING.
MODELS CONTINUE TO INDICATE THAT THE LOW LEVEL TEMPERATURES WILL
MODIFY SOME ON THURSDAY WITH THE RETURN OF THE SUN. OUR FORECAST
MAY BE TOO WARM THURSDAY IF THE FEED OF UPPER LEVEL MOISTURE
ASSOCIATED WITH A CUT OFF LOW NEAR BAJA KEEPS SKIES CLOUDY.
ALSO...WILL HAVE TO CONSIDER THAT ANY TYPE OF SNOW COVER WOULD
ALSO AFFECT HIGH TEMPERATURES THURSDAY. EVEN IF TEMPS DO WARM
ABOVE FREEZING THURSDAY...THEY WILL MOSTLY LIKELY FALL BACK INTO
THE 20S THURSDAY NIGHT WHICH WOULD REFREEZE ANY RESIDUAL WATER.
THE EXTENDED MODELS KEEP THE GULF SHUT OFF THURSDAY NIGHT THROUGH
SUNDAY WHICH SHOULD KEEP TEMPERATURES BELOW NORMAL WITH MINIMAL
RAIN CHANCES.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 36 44 44 70 42 / 40 40 40 40 60
WACO, TX 37 45 45 73 48 / 40 30 30 30 60
PARIS, TX 36 45 42 68 41 / 50 50 50 60 60
DENTON, TX 35 42 42 71 38 / 40 30 40 40 60
MCKINNEY, TX 36 42 42 69 40 / 40 40 50 40 60
DALLAS, TX 36 44 44 70 42 / 40 40 50 40 60
TERRELL, TX 38 44 44 69 44 / 50 40 40 40 60
CORSICANA, TX 36 46 46 71 48 / 50 40 30 40 60
TEMPLE, TX 36 45 45 71 50 / 40 30 30 30 50
MINERAL WELLS, TX 36 39 39 70 38 / 30 20 40 30 60
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
350 AM EST MON MAR 2 2015
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A RATHER COMPLEX UPPER
LEVEL PATTERN ACROSS THE CONUS THIS MORNING. MAIN NORTHERN STREAM
FLOW IS DIPPING SOUTH FROM CANADA IN THE FORM OF A LONGWAVE TROUGH
OVER THE GREAT LAKES/NORTHEASTERN STATES. ANOTHER SIGNIFICANT
FEATURE IS THE DEEP TROUGH/CLOSED LOW SPINNING OVER SOUTHERN
CALIFORNIA. THIS FEATURE MAY BE ON THE OTHER SIDE OF THE
CONTINENT...BUT IT WILL HAVE AN INFLUENCE ON OUR WEATHER DURING THE
NEXT SEVERAL DAYS. CURRENTLY A LARGE AREA OF UPPER LEVEL RIDGING
EXISTS TO OUR SOUTH EXTENDING FROM THE BAY OF CAMPECHE TO THE
WESTERN CARIBBEAN. AS THE TROUGH OVER THE SOUTHWEST BEGINS TO EJECT
EASTWARD IN THE NEXT 24-36 HOURS...IT WILL FORCE THE DOWNSTREAM
PATTERN/RIDGE TO AMPLIFY NORTHWARD OVER THE EASTERN GULF OF MEXICO
AND FLORIDA PENINSULA. THE BUILDING UPPER RIDGE WILL PROVIDE OUR
AREA WITH A SPRING-LIKE FORECAST THE NEXT SEVERAL DAYS CONSISTING OF
MAINLY DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES.
AT THE SURFACE...A MUCH WEAKER PRESSURE PATTERN THAN IN DAYS PAST IS
PROVIDING ONLY A LIGHT EASTERLY FLOW. CONTINENTAL HIGH PRESSURE
CURRENTLY OVER THE UPPER MIDWEST WILL QUICKLY BE SLIDING EASTWARD
AND OFF THE ATLANTIC SEABOARD DURING THE NEXT 2 DAYS. THIS HIGH WILL
EVENTUALLY FIND A HOME OF THE WESTERN ATLANTIC AND END UP RIDGING
BACK TO THE WEST OVER THE FL PENINSULA AND EASTERN GULF OF THE
MIDDLE PORTION OF THE WEEK.
CONSIDERABLE AREA OF LOW CLOUDS/FOG HAS BEEN EXPANDING SOUTHWARD
FROM THE NORTHERN PENINSULA TOWARD THE I-4 CORRIDOR THE PAST SEVERAL
HOURS. WATCHING THE VISIBILITY VALUES CLOSELY AS MAY NEED TO
CONSIDER A DENSE FOG ADVISORY FOR SOME AREA IN THE NEAR FUTURE.
FORECAST DILEMMA THE NEXT FEW HOURS WILL BE HOW FAR SOUTH THIS AREA
OF FOG CAN GET BEFORE THE SUN RISES AND STARTS TO MIX IT OUT. NONE
OF THE MODEL MEMBERS CURRENTLY ARE HANDLING THIS AREA OF FOG VERY
WELL...SO SIMPLY TRACKING ITS CURRENT MOVEMENT AND SPEED TO
DETERMINE A BEST GUESS AS TO WHICH AREAS WILL BE IMPACTED BEFORE
SUNRISE. APPEARS AS THOUGH THIS FOG WILL MAKE IT AT LEAST SOUTH TO
PARTS OF MANATEE/HARDEE/NORTHERN HIGHLANDS. SOMETIMES ALL THE SKILL
IN THE WORLD WILL NOT HELP YOU IN THE TRICKY ART OF FORECASTING FOG.
SOMETIMES IT IS JUST A "WAIT AND SEE...THROW YOUR HANDS UP...PULL
YOUR HAIR OUT" TYPE OF NIGHT.
&&
.SHORT TERM (TODAY THROUGH TUESDAY)...
THE DOMINANT PLAYER IN OUR WEATHER THE NEXT TWO DAYS WILL BE THE
BUILDING UPPER RIDGE FROM THE WESTERN CARIBBEAN. THIS RIDGE WILL BE
BUILDING/STRENGTHENING OVERHEAD THROUGH TODAY...AND REACH ITS MOST
AMPLIFIED STATE TUESDAY INTO EARLY WEDNESDAY. MID LEVEL TEMPERATURES
WILL BE MODERATING OVER TIME AS WELL AS THE RIDGE AND ITS LARGE
SCALE SUPPRESSION TAKES OVER. FORECAST SOUNDINGS BOTH LATER TODAY
AND TUESDAY SHOW VERY POOR LAPSE RATES ALOFT...SO EVEN THROUGH WE
WILL SEE SEA-BREEZE FORMATION EACH OF THE NEXT FEW AFTERNOONS...AND
THE LOWER LEVELS ARE FAIRLY MOIST FOR EARLY MARCH...ANY UPDRAFTS ARE
GOING TO REALLY STRUGGLE AND DO NOT ANTICIPATE EVEN ISOLATED SHOWER
ACTIVITY TO BE ABLE TO BECOME ESTABLISHED. FORECAST POPS ARE GOING
TO BE BELOW 10% THROUGH THE SHORT TERM.
IN TERMS OF TEMPERATURES...IT WILL BE AN ABOVE AVERAGE PERIOD BOTH
DAY AND AT NIGHT. THERE IS LITTLE REASON GIVEN THE LOWER LEVEL
PROFILE AND LARGE SCALE SUBSIDENCE...THAT HIGH TEMPERATURES WILL
CLIMB INTO THE UPPER 70S TO LOWER 80S NORTH OF I-4...AND LOWER TO
MIDDLE 80S SOUTH OF I-4. THE ONLY PLACES THAT MAY STRUGGLE TO REACH
80 WILL BE ALONG THE IMMEDIATE COAST...WHERE SEA-BREEZE FORMATION BY
THE EARLY AFTERNOON HOURS WILL SHIFT WINDS ONSHORE OFF THE
RELATIVELY COOLER SHELF WATERS. IT IS POSSIBLE THAT THE BEACHES MAY
BRIEFLY GET UP NEAR 80 BEFORE THE SEA-BREEZE KICKS IN AND DROPS
TEMPS BACK DOWN THROUGH THE 70S. HOWEVER...EITHER WAY...TEMPS WILL
BE QUITE PLEASANT REGION-WIDE FOR THE SHORT TERM PERIOD. LOW
TEMPERATURES THE NEXT COUPLE OF NIGHTS SHOULD RANGE FROM THE UPPER
50S AROUND LEVY/CITRUS COUNTIES...TO THE LOWER AND MIDDLE 60S
FURTHER SOUTH TOWARD I-4...AND THE REMAINDER OF OUR SOUTHERN ZONES.
MOST LIKELY THE MAIN FORECAST DILEMMA DURING THE SHORT TERM WILL BE
THE POTENTIAL FOR FOG OVER LAND EACH NIGHT...AND EVENTUALLY THE
INCREASING THREAT FOR SEA FOG OVER THE NEARSHORE MARINE WATERS. THE
SREF/NARRE ARE SHOWING HIGH PROBABILITIES OF SEA FOG BY LATER TODAY.
GENERALLY SPEAKING...THE ENSEMBLE GUIDANCE IS A BIT TOO
AGGRESSIVE/FAST IN DEVELOPING SEA FOG...AND WITH THE GENERAL FLOW
STILL OUT OF THE EAST (OTHER THAN THE SEA-BREEZE)...WOULD NOT
ANTICIPATE MUCH MORE THAN PATCHY FOG (IF THAT) THROUGH TONIGHT FOR
THE COASTAL WATERS. BASED ON A MORE FAVORABLE SYNOPTIC SETUP FOR SEA
FOG...THE THREAT SHOULD NOT REALLY INCREASE UNTIL LATER
TUESDAY...AND ESPECIALLY ON WEDNESDAY AS WINDS SHIFT MORE TO THE
SOUTH. OVER LAND...THE SUPPRESSION OF THE UPPER RIDGE OVERTOP A
GENERALLY MOIST BOUNDARY LAYER DURING THE OVERNIGHT HOURS IS
FAVORABLE FOR FOG DEVELOPMENT... AND WILL CONTINUE TO HIGHLIGHT
AREAS OF FOG IN THE FORECAST EARLY THIS MORNING AND AGAIN MONDAY
NIGHT/EARLY TUESDAY MORNING.
&&
.LONG TERM (WEDNESDAY THROUGH NEXT SUNDAY)...
THROUGH THU; THE AREA WILL BE UNDER DEEP LAYER RIDGING WITH A STABLE
WARM AND GENERALLY DRY AIRMASS. AN ELONGATED UPPER RIDGE CENTERED
NEAR THE YUCATAN CHANNEL SLIDES EAST-NORTHEAST TO THE BAHAMAS...AS
A LONG WAVE TROUGH TRACKS EASTWARD ACROSS THE MID-CONUS...WHILE
SURFACE HIGH PRESSURE IN THE OPEN ATLANTIC RIDGES ACROSS FL INTO THE
GULF. THIS RESULTS IN SOUTHERLY WINDS WHICH WITH INCREASING LOW
LEVEL MOISTURE PROVIDES THE POTENTIAL FOR SOME SEA FOG.
DURING THU AND THROUGH FRI; THE LONG WAVE TROUGH CROSSES THE EASTERN
CONUS AS IT DAMPENS OUT...WITH AN ACCOMPANYING FRONTAL BOUNDARY
SAGGING IN ALONG THE GULF COAST/ ECMWF/ OR ACROSS NORTHERN GULF
WATERS THROUGH ROUGHLY THE NORTHERN HALF OF FL/ GFS/ AND BECOMING
DIFFUSE. IN EITHER CASE THERE WILL BE ENOUGH MOISTURE AND LIFT
AROUND THE AREA FOR ISOLATED TO LOW END SCATTERED SHOWERS WITH
A FEW STORMS. THE UPPER RIDGE OVER THE BAHAMAS SETTLES
SOUTHEASTWARD.
SAT AND SUN; THE UPPER RIDGE BUILDS BACK IN SOUTH OF THE AREA WHILE
A LONG WAVE TROUGH DEEPENS OVER THE CENTRAL CONUS...WITH NEARLY
ZONAL FLOW ACROSS THE GULF AND FL. THE BOUNDARY MEANDERS IN
PLACE...WITH THE ECMWF LIFTING IT SLIGHTLY NORTHWARD FROM THE GULF
COAST WHILE THE GFS LOCATES IT ACROSS CENTRAL FL WITH A LOW PRESSURE
CENTER FORMING ON THE OPEN ATLANTIC PORTION. HIGH PRESSURE MOVING
EAST ACROSS THE EASTERN CONUS WILL BRIDGE THE BOUNDARY WITH NORTH
AND NORTHEAST WINDS FILTERING IN OVER THE AREA. TEMPERATURES COOL
THROUGH THE WEEKEND...DOWN TO NEAR NORMAL OR BELOW IN THE NORTH
WHILE THE SOUTH WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...
TRACKING AN EXPANDING AREA OF LOW CLOUDS/FOG MOVING DOWN TOWARD THE
I-4 CORRIDOR. SIGNIFICANT VIS AND/OR CIG RESTRICTIONS LOOK LIKELY
THE NEXT SEVERAL HOURS FOR KLAL. TOUGH CALL AS TO WHETHER KTPA/KPIE
WILL BE IMPACTED BEFORE SUNRISE. CURRENTLY HAVE LOW END MVFR IN THE
TAF ALREADY AFTER 09Z FOR THESE TERMINALS...BUT WILL BE MONITORING
TRENDS CLOSELY AND WILL AMEND LOWER IF NECESSARY. FURTHER
SOUTH...THE FOG IS MORE PATCHY IN NATURE...ALTHOUGH KPGD/KFMY/KRSW
MAY SEE PERIODIC IFR/MVFR VIS RESTRICTIONS BEFORE SUNRISE. AFTER ANY
MORNING FOG/LOW CLOUDS BURN OFF...THE MAJORITY OF THE DAY LOOKS TO
FEATURE PREVAILING VFR CONDITIONS WITH GENERALLY LIGHT EASTERLY
WINDS SHIFTING WESTERLY MID/LATE AFTERNOON FOR THE COASTAL TERMINALS
OF KTPA/KPIE/KSRQ.
&&
.MARINE...
WINDS AND SEAS WILL REMAIN LOW ACROSS THE EASTERN GULF OF MEXICO
THROUGH THE MIDDLE OF THE WEEK. A GENERAL EASTERLY FLOW REGIME
THROUGH TUESDAY WILL BE INTERRUPTED EACH AFTERNOON NEAR THE COAST BY
SEA BREEZE DEVELOPMENT WHICH WILL TURN THE WINDS LOCALLY ONSHORE.
WINDS BECOME MORE SOUTHERLY ON WEDNESDAY AS A COLD FRONT APPROACHES
FROM THE NORTHWEST. THIS FRONT IS FORECAST TO PASS THROUGH THE
FORECAST WATERS DURING THURSDAY OR THURSDAY NIGHT WITH A WIND SHIFT
TO THE NORTH AND NORTHEAST. AHEAD OF THIS FRONT...THE POTENTIAL FOR
THE DEVELOPMENT OF AREAS OF SEA FOG WILL INCREASE. ALTHOUGH PATCHY
SEA FOG IS POSSIBLE TODAY AND TUESDAY...IF SIGNIFICANT SEA FOG AREAS
ARE GOING TO DEVELOP...THE MOST LIKELY TIME FRAME WILL BE TUESDAY
NIGHT THROUGH THURSDAY MORNING. THE PASSAGE OF THE COLD FRONT LATER
THURSDAY WILL END THE SEA FOG THREAT.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY VALUES WILL REMAIN WELL ABOVE CRITICAL LEVELS
DURING THE NEXT SEVERAL DAYS...DESPITE ABOVE NORMAL TEMPERATURES. NO
SIGNIFICANT FIRE WEATHER CONCERNS ARE EXPECTED OUTSIDE OF OVERNIGHT
AND EARLY MORNING AREAS OF FOG THE NEXT SEVERAL NIGHT.
FOG POTENTIAL...
PATCHY/AREAS OF FOG ARE EXPECTED TO DEVELOP DURING THE LATE NIGHT
AND EARLY MORNING HOURS THROUGH THE MIDDLE OF THE WEEK. SOME OF THE
FOG IS LIKELY TO BECOME LOCALLY DENSE AT TIMES. WIDESPREAD DENSE FOG
IS NOT ANTICIPATED AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 79 65 78 64 / 10 0 0 0
FMY 84 65 83 64 / 10 10 0 0
GIF 82 64 82 64 / 10 10 10 0
SRQ 81 64 78 63 / 10 0 0 0
BKV 82 61 82 58 / 10 10 10 10
SPG 80 65 78 65 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT SERVICES...RUDE
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
411 AM EST MON MAR 2 2015
.UPDATE...
NEW OBS HAVE COME IN AND ARE INDICATING THE PATCHY DENSE FOG IS
BECOMING MORE WIDESPREAD. GOING TO ISSUE A DENSE FOG ADVISORY.
&&
.PREV DISCUSSION... /ISSUED 344 AM EST MON MAR 2 2015/
SHORT TERM /TODAY THROUGH TUESDAY/...
A COLD FRONT CURRENTLY STRETCHES FROM CENTRAL NEW YORK STATE BACK TO
SOUTHWEST LOUISIANA THIS MORNING. THERE IS SOME SPOTTY PRECIPITATION
ASSOCIATED WITH THE BOUNDARY...CURRENTLY MOVING ACROSS CENTRAL
ALABAMA. THE TREND FOR THE LAST FEW HOURS IS FOR THE PRECIP TO
DWINDLE AS IT MOVES ACROSS THE CWFA. THE HRRR MODEL SUPPORTS THIS
CONTINUING TREND.
WEAK WEDGE WILL CONTINUE TO ERODE AWAY THIS MORNING AS THE COLD
FRONT APPROACHES THE CWFA. EXPECT THE LOW CLOUDS AND FOG TO LIFT A
BIT AFTER SUNRISE...BUT SKIES WILL REMAIN CLOUDY. ANTICIPATE THAT
THE FRONT WILL MOVE ACROSS NORTHERN GEORGIA...AND POSSIBLY MAKE IT
AS FAR SOUTH AS THE ATLANTA METRO BY EARLY AFTERNOON. NOT CONFIDENT
ON EXACTLY WHERE THE FRONT WILL STALL...BUT IT SHOULD BE SOMEWHERE
IN THE VICINITY OF THE INTERSTATE 20 CORRIDOR. TEMPERATURES ON THE
SOUTH SIDE OF THE BOUNDARY WILL BE MUCH WARMER AND HAVE THE
POTENTIAL TO REACH THE MIDDLE TO UPPER 60S IN THE SOUTHERLY
FLOW...NORTH OF THE BOUNDARY TEMPS WILL RANGE FROM THE MIDDLE 40S IN
THE HIGHER ELEVATIONS TO UPPER 50S NEAR CENTRAL GA. THE MAX TEMPS
TODAY WILL DEPEND HIGHLY UPON EXACTLY HOW FAR SOUTH THIS WEAK FRONT
WILL MAKE IT.
WEAK WEDGING WILL TRY AND SET UP IN THE NORTHEAST OVERNIGHT AND
TUESDAY AS HIGH PRESSURE SHIFTS OFFSHORE. THIS WILL CREATE A SHARP
MAX TEMP GRADIENT DURING THE DAY ON TUESDAY. AREAS SOUTH OF THE WEAK
FRONT COULD REACH ALL THE WAY INTO THE LOWER 70S...WHILE AREAS NORTH
OF THE FRONT...IN THE WEDGE...WILL REMAIN THE IN UPPER 40S TO NEAR
50. AGAIN...THE MAX TEMP FORECAST WILL HIGHLY DEPEND UPON WHERE THE
WEAK FRONT AND WEDGE SET UP. THE MORAL OF THE STORY IS...TODAY AND
TUESDAY WILL HAVE HIGH BUST POTENTIAL FOR MAX TEMPS.
AREAS OF FOG AND DRIZZLE SHOULD CONTINUE THROUGH MID MORNING.
VISIBILITIES BETWEEN ONE QUARTER AND ONE HALF OF A MILE ARE POSSIBLE
DURING THE MORNING COMMUTE. IF THE PATCHY DENSE FOG BECOMES MORE
WIDESPREAD...WILL HAVE TO CONSIDER ISSUING A DENSE FOG ADVISORY FOR
PORTIONS OF THE CWFA.
THE HRRR KEEPS MOST OF THE FORECAST AREA PRETTY DRY...WITH JUST
SPOTTY AREAS OF PRECIP TODAY. THE BEST PLACES FOR MEASURABLE
RAINFALL SHOULD BE ALONG THE AL/GA BORDER AND NORTH OF INTERSTATE 20
TODAY. PATCHY LIGHT RAIN AND DRIZZLE IS EXPECTED TO DEVELOP ONCE
AGAIN NORTH OF THE WEAK FRONT OVERNIGHT. BY TUESDAY...A LITTLE
INSTABILITY BEGINS TO DEVELOP ACROSS THE AREA. SOME SURFACE
INSTABILITY IS POSSIBLE SOUTH OF THE BOUNDARY...BUT THERE IS ALSO
SOME POTENTIAL FOR ELEVATED INSTABILITY NORTH OF THE BOUNDARY.
OVERALL...JUST THINK THE MENTION OF A SLIGHT CHANCE OF THUNDER
SHOULD SUFFICE.
NLISTEMAA
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MEDIUM RANGE MODELS REMAIN CONSISTENT AND IN RELATIVELY GOOD
AGREEMENT THROUGH THE MAJORITY OF THE EXTENDED FORECAST PERIOD.
STILL SHOWING THE WORK WEEK DOMINATED BY SOUTHWESTERLY UPPER FLOW
AHEAD OF THE DEEP WESTERN U.S. TROUGH. THIS KEEPS THE REGION IN A
FAIRLY WARM PATTERN UNTIL THURSDAY BEHIND THE SHARP SURFACE FRONT
THE SWEEPS THROUGH WEDNESDAY/WEDNESDAY NIGHT. STILL SEEING ENOUGH
INSTABILITY FOR CHANCE COVERAGE OF THUNDERSTORMS WEDNESDAY. STRONG
LOW/MID-LEVEL WINDS ALSO STILL HAVE ME A BIT CONCERNED ABOUT AT
LEAST ISOLATED SEVERE THUNDERSTORM POTENTIAL. GOOD LOW-LEVEL FORCING
AHEAD OF THE FRONT BUT UPPER SUPPORT IS LACKING WITH THE MAIN UPPER
TROUGH/SHORT WAVE LAGGING FAR BEHIND THE FRONT. GFS AND ECMWF ALSO
STILL INSIST ON BRINGING IN MUCH COLDER AIR AS EARLY AS LATE
WEDNESDAY NIGHT WITH RESIDUAL MOISTURE AND THE INFLUENCE OF THE
UPPER SYSTEM SQUEEZING OUT SOME LOW QPF PRECIPITATION. UPPER FLOW
REMAINS SOUTHWESTERLY THROUGH THURSDAY AND LOWEST THICKNESSES REMAIN
WELL NORTH OF THE STATE. WILL NEED TO WATCH TRENDS FOR THE
POSSIBILITY OF SOME WINTRY MIX ACROSS THE NORTH. GFS AND ECMWF BOTH
SHOW A GOOD TEMPERATURE RECOVERY INTO THE WEEKEND AFTER A THE SHOT
OF COOL AIR THURSDAY THROUGH FRIDAY MORNING AS THE UPPER FLOW
REMAINS GENERALLY ZONAL OVER THE SOUTHEASTERN U.S. AND THE HEART OF
THE COLDEST AIR REMAINS WELL NORTH OF THE STATE. MAINLY DRY AS
WELL...HOWEVER BOTH MODELS SHOW SOME PRECIPITATION POSSIBLY SURGING
NORTH INTO CENTRAL GEORGIA SATURDAY AS SURFACE LOW PRESSURE SPINS UP
OFF THE GEORGIA/CAROLINA COAST. NOT REAL CONFIDENT WE WILL SEE
ANYTHING SIGNIFICANT WITH THIS BUT SLIGHT CHANCE OR LOW CHANCE POPS
MAY BE APPROPRIATE.
20
AVIATION...
06Z UPDATE...
LOW CIGS AND DRIZZLE EXPECTED TO HANG AROUND UNTIL AT LEAST MID
MORNING...WHEN A WEAK FRONT BEGINS TO APPROACH THE NORTHERN
TERMINAL SITES. THE FRONT LOOKS TO STALL AND WASH OUT SOMEWHERE
ACROSS NORTHERN GA LATER TODAY AND TONIGHT. HRRR HAS BACKED OFF ON
THE ORGANIZED SHOWERS ALONG/AHEAD OF THE FROPA...SO HAVE REMOVED
THE PROB30 FOR SHOWERS DURING THE MIDDAY PERIOD. MAY HAVE A BRIEF
PERIOD OF IFR CIGS DURING THE AFTERNOON...BUT DO EXPECT CIGS TO GO
BACK BELOW 010 AFTER DARK. WINDS ARE GOING TO BE LIGHT AND
VARIABLE WITH THE WEAK FRONT/TROUGH OVERHEAD. GENERALLY...WINDS
SHOULD TRY TO SWITCH AROUND TO THE NW BY EARLY AFTERNOON.
OVERNIGHT...A SWITCH TO THE NE IS POSSIBLE AS THE SURFACE HIGH
MOVES OFFSHORE.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 63 46 50 48 / 40 60 70 50
ATLANTA 58 49 60 55 / 40 60 60 40
BLAIRSVILLE 53 44 48 48 / 90 60 70 70
CARTERSVILLE 52 46 56 53 / 60 60 70 60
COLUMBUS 65 58 73 59 / 40 30 20 20
GAINESVILLE 59 45 48 46 / 40 60 70 60
MACON 66 56 69 57 / 20 40 40 20
ROME 49 45 57 54 / 80 60 60 60
PEACHTREE CITY 59 51 62 56 / 40 40 40 30
VIDALIA 69 57 69 60 / 20 30 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR THE FOLLOWING
ZONES: BALDWIN...BANKS...BARROW...BARTOW...BIBB...BLECKLEY...
BUTTS...CARROLL...CHATTAHOOCHEE...CHEROKEE...CLARKE...CLAYTON...
COBB...COWETA...CRAWFORD...CRISP...DEKALB...DODGE...DOOLY...
DOUGLAS...EMANUEL...FAYETTE...FORSYTH...GLASCOCK...GREENE...
GWINNETT...HALL...HANCOCK...HARALSON...HARRIS...HEARD...HENRY...
HOUSTON...JACKSON...JASPER...JEFFERSON...JOHNSON...JONES...
LAMAR...LAURENS...MACON...MADISON...MARION...MERIWETHER...
MONROE...MONTGOMERY...MORGAN...MUSCOGEE...NEWTON...NORTH
FULTON...OCONEE...OGLETHORPE...PAULDING...PEACH...PIKE...POLK...
PULASKI...PUTNAM...ROCKDALE...SCHLEY...SOUTH FULTON...SPALDING...
STEWART...SUMTER...TALBOT...TALIAFERRO...TAYLOR...TELFAIR...
TOOMBS...TREUTLEN...TROUP...TWIGGS...UPSON...WALTON...WARREN...
WASHINGTON...WEBSTER...WHEELER...WILCOX...WILKES...WILKINSON.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
344 AM EST MON MAR 2 2015
.SHORT TERM /TODAY THROUGH TUESDAY/...
A COLD FRONT CURRENTLY STRETCHES FROM CENTRAL NEW YORK STATE BACK TO
SOUTHWEST LOUISIANA THIS MORNING. THERE IS SOME SPOTTY PRECIPITATION
ASSOCIATED WITH THE BOUNDARY...CURRENTLY MOVING ACROSS CENTRAL
ALABAMA. THE TREND FOR THE LAST FEW HOURS IS FOR THE PRECIP TO
DWINDLE AS IT MOVES ACROSS THE CWFA. THE HRRR MODEL SUPPORTS THIS
CONTINUING TREND.
WEAK WEDGE WILL CONTINUE TO ERODE AWAY THIS MORNING AS THE COLD
FRONT APPROACHES THE CWFA. EXPECT THE LOW CLOUDS AND FOG TO LIFT A
BIT AFTER SUNRISE...BUT SKIES WILL REMAIN CLOUDY. ANTICIPATE THAT
THE FRONT WILL MOVE ACROSS NORTHERN GEORGIA...AND POSSIBLY MAKE IT
AS FAR SOUTH AS THE ATLANTA METRO BY EARLY AFTERNOON. NOT CONFIDENT
ON EXACTLY WHERE THE FRONT WILL STALL...BUT IT SHOULD BE SOMEWHERE
IN THE VICINITY OF THE INTERSTATE 20 CORRIDOR. TEMPERATURES ON THE
SOUTH SIDE OF THE BOUNDARY WILL BE MUCH WARMER AND HAVE THE
POTENTIAL TO REACH THE MIDDLE TO UPPER 60S IN THE SOUTHERLY
FLOW...NORTH OF THE BOUNDARY TEMPS WILL RANGE FROM THE MIDDLE 40S IN
THE HIGHER ELEVATIONS TO UPPER 50S NEAR CENTRAL GA. THE MAX TEMPS
TODAY WILL DEPEND HIGHLY UPON EXACTLY HOW FAR SOUTH THIS WEAK FRONT
WILL MAKE IT.
WEAK WEDGING WILL TRY AND SET UP IN THE NORTHEAST OVERNIGHT AND
TUESDAY AS HIGH PRESSURE SHIFTS OFFSHORE. THIS WILL CREATE A SHARP
MAX TEMP GRADIENT DURING THE DAY ON TUESDAY. AREAS SOUTH OF THE WEAK
FRONT COULD REACH ALL THE WAY INTO THE LOWER 70S...WHILE AREAS NORTH
OF THE FRONT...IN THE WEDGE...WILL REMAIN THE IN UPPER 40S TO NEAR
50. AGAIN...THE MAX TEMP FORECAST WILL HIGHLY DEPEND UPON WHERE THE
WEAK FRONT AND WEDGE SET UP. THE MORAL OF THE STORY IS...TODAY AND
TUESDAY WILL HAVE HIGH BUST POTENTIAL FOR MAX TEMPS.
AREAS OF FOG AND DRIZZLE SHOULD CONTINUE THROUGH MID MORNING.
VISIBILITIES BETWEEN ONE QUARTER AND ONE HALF OF A MILE ARE POSSIBLE
DURING THE MORNING COMMUTE. IF THE PATCHY DENSE FOG BECOMES MORE
WIDESPREAD...WILL HAVE TO CONSIDER ISSUING A DENSE FOG ADVISORY FOR
PORTIONS OF THE CWFA.
THE HRRR KEEPS MOST OF THE FORECAST AREA PRETTY DRY...WITH JUST
SPOTTY AREAS OF PRECIP TODAY. THE BEST PLACES FOR MEASURABLE
RAINFALL SHOULD BE ALONG THE AL/GA BORDER AND NORTH OF INTERSTATE 20
TODAY. PATCHY LIGHT RAIN AND DRIZZLE IS EXPECTED TO DEVELOP ONCE
AGAIN NORTH OF THE WEAK FRONT OVERNIGHT. BY TUESDAY...A LITTLE
INSTABILITY BEGINS TO DEVELOP ACROSS THE AREA. SOME SURFACE
INSTABILITY IS POSSIBLE SOUTH OF THE BOUNDARY...BUT THERE IS ALSO
SOME POTENTIAL FOR ELEVATED INSTABILITY NORTH OF THE BOUNDARY.
OVERALL...JUST THINK THE MENTION OF A SLIGHT CHANCE OF THUNDER
SHOULD SUFFICE.
NLISTEMAA
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MEDIUM RANGE MODELS REMAIN CONSISTENT AND IN RELATIVELY GOOD
AGREEMENT THROUGH THE MAJORITY OF THE EXTENDED FORECAST PERIOD.
STILL SHOWING THE WORK WEEK DOMINATED BY SOUTHWESTERLY UPPER FLOW
AHEAD OF THE DEEP WESTERN U.S. TROUGH. THIS KEEPS THE REGION IN A
FAIRLY WARM PATTERN UNTIL THURSDAY BEHIND THE SHARP SURFACE FRONT
THE SWEEPS THROUGH WEDNESDAY/WEDNESDAY NIGHT. STILL SEEING ENOUGH
INSTABILITY FOR CHANCE COVERAGE OF THUNDERSTORMS WEDNESDAY. STRONG
LOW/MID-LEVEL WINDS ALSO STILL HAVE ME A BIT CONCERNED ABOUT AT
LEAST ISOLATED SEVERE THUNDERSTORM POTENTIAL. GOOD LOW-LEVEL FORCING
AHEAD OF THE FRONT BUT UPPER SUPPORT IS LACKING WITH THE MAIN UPPER
TROUGH/SHORT WAVE LAGGING FAR BEHIND THE FRONT. GFS AND ECMWF ALSO
STILL INSIST ON BRINGING IN MUCH COLDER AIR AS EARLY AS LATE
WEDNESDAY NIGHT WITH RESIDUAL MOISTURE AND THE INFLUENCE OF THE
UPPER SYSTEM SQUEEZING OUT SOME LOW QPF PRECIPITATION. UPPER FLOW
REMAINS SOUTHWESTERLY THROUGH THURSDAY AND LOWEST THICKNESSES REMAIN
WELL NORTH OF THE STATE. WILL NEED TO WATCH TRENDS FOR THE
POSSIBILITY OF SOME WINTRY MIX ACROSS THE NORTH. GFS AND ECMWF BOTH
SHOW A GOOD TEMPERATURE RECOVERY INTO THE WEEKEND AFTER A THE SHOT
OF COOL AIR THURSDAY THROUGH FRIDAY MORNING AS THE UPPER FLOW
REMAINS GENERALLY ZONAL OVER THE SOUTHEASTERN U.S. AND THE HEART OF
THE COLDEST AIR REMAINS WELL NORTH OF THE STATE. MAINLY DRY AS
WELL...HOWEVER BOTH MODELS SHOW SOME PRECIPITATION POSSIBLY SURGING
NORTH INTO CENTRAL GEORGIA SATURDAY AS SURFACE LOW PRESSURE SPINS UP
OFF THE GEORGIA/CAROLINA COAST. NOT REAL CONFIDENT WE WILL SEE
ANYTHING SIGNIFICANT WITH THIS BUT SLIGHT CHANCE OR LOW CHANCE POPS
MAY BE APPROPRIATE.
20
&&
AVIATION...
06Z UPDATE...
LOW CIGS AND DRIZZLE EXPECTED TO HANG AROUND UNTIL AT LEAST MID
MORNING...WHEN A WEAK FRONT BEGINS TO APPROACH THE NORTHERN
TERMINAL SITES. THE FRONT LOOKS TO STALL AND WASH OUT SOMEWHERE
ACROSS NORTHERN GA LATER TODAY AND TONIGHT. HRRR HAS BACKED OFF ON
THE ORGANIZED SHOWERS ALONG/AHEAD OF THE FROPA...SO HAVE REMOVED
THE PROB30 FOR SHOWERS DURING THE MIDDAY PERIOD. MAY HAVE A BRIEF
PERIOD OF IFR CIGS DURING THE AFTERNOON...BUT DO EXPECT CIGS TO GO
BACK BELOW 010 AFTER DARK. WINDS ARE GOING TO BE LIGHT AND
VARIABLE WITH THE WEAK FRONT/TROUGH OVERHEAD. GENERALLY...WINDS
SHOULD TRY TO SWITCH AROUND TO THE NW BY EARLY AFTERNOON.
OVERNIGHT...A SWITCH TO THE NE IS POSSIBLE AS THE SURFACE HIGH
MOVES OFFSHORE.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 63 46 50 48 / 40 60 70 50
ATLANTA 58 49 60 55 / 40 60 60 40
BLAIRSVILLE 53 44 48 48 / 90 60 70 70
CARTERSVILLE 52 46 56 53 / 60 60 70 60
COLUMBUS 65 58 73 59 / 40 30 20 20
GAINESVILLE 59 45 48 46 / 40 60 70 60
MACON 66 56 69 57 / 20 40 40 20
ROME 49 45 57 54 / 80 60 60 60
PEACHTREE CITY 59 51 62 56 / 40 40 40 30
VIDALIA 69 57 69 60 / 20 30 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....20
AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1231 AM EST MON MAR 2 2015
.PREV DISCUSSION... /ISSUED 1029 PM EST SUN MAR 1 2015/
EVENING UPDATE...
AREA WINDS ARE SWINGING AROUND MORE SOUTHERLY NOW AND HELPING TO
ERODE THE EFFECTS OF THE COOL WEDGE. THIS HAS WARRANTED BUMPING UP
THE EXPECTED LOWS BY A FEW DEGREES OR MORE. OTHERWISE... STILL
EXPECT AREAS OF LIGHT RAIN... DRIZZLE AND PATCHY FOG TO PREVAIL
THROUGH MONDAY MORNING... SO ONLY MADE ADJUSTMENTS TO THE LOW TEMPS
AT THIS TIME. /39
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
/ISSUED AT 258 PM EST SUN MAR 1 2015/
WEDGE HOLDING THIS AFTERNOON WITH WIDESPREAD CLOUDS AND PATCHES OF
RAIN/DRIZZLE. HIGH PRESSURE SHOULD BE WEAKENING OVERNIGHT WITH
DECREASING EASTERLY FLOW...HOWEVER LOWER LAYERS OF THE ATMOSPHERE
REMAIN SATURATED AND SHOULD HAVE LOW CLOUDS WITH SOME FOG/DRIZZLE
THROUGH THE NIGHT. NO OBVIOUS FEATURES TO KEY IN ON...BUT RAIN
COMING ACROSS AL INTO NORTH GA MAY BE WITH A WEAK SHORT WAVE SO HAVE
HIGHEST POPS IN THAT AREA THROUGH TONIGHT. UPPER FLOW GOES MOSTLY
ZONAL TO WEST/SOUTHWEST MONDAY AND MONDAY NIGHT. THIS KEEPS THE
NORTH IN A ZONE OF DEEPER MOISTURE AND WEAK WAVES SO HAVE KEPT
HIGHER POPS NORTH...DECREASING INTO CENTRAL GEORGIA MONDAY AND
MONDAY NIGHT.
TEMPERATURE TREND SHOULD BE NEARLY STEADY OVERNIGHT AND HAVE TRIED
TO ADJUST FOR THIS. AT LEAST NO FREEZING TEMPERATURES IN THE
FORECAST.
41
LONG TERM /TUESDAY THROUGH SUNDAY/...
/ISSUED AT 258 PM EST SUN MAR 1 2015/
START TUESDAY WITH ANOTHER WEDGE IN PLACE SO HAVE BROUGHT
TEMPERATURES DOWN ACROSS THE NE BELOW GUIDANCE. STILL LOOKING AT A
SLOW MOVING FRONT MOVING INTO THE CWA ON WEDNESDAY WITH THE GFS THE
FASTEST SOLUTION AND THE NAM THE SLOWEST. HAVE GONE AHEAD AND BUMPED
UP POPS INTO THE CATEGORICAL RANGE FOR WEDNESDAY AND WEDNESDAY NIGHT
ACROSS THE NORTH SINCE GUIDANCE IS VERY SLOW WITH PUSHING THE FRONT
THROUGH. STILL LOOKING AT A CHANCE OF THUNDERSTORMS IN THE FORECAST
TUESDAY NIGHT INTO WEDNESDAY...WITH THE BEST CHANCES ACROSS NORTH
AND THE NORTHERN PORTIONS OF CENTRAL GEORGIA ON WEDNESDAY WITH
MUCAPE VALUES AROUND 300 J/KG /JUST SLIGHTLY LESS THAN YESTERDAY/.
NOT QUITE AS MUCH AREA WITH 40KTS OF LOW LEVEL SHEAR BUT STILL
SOMETHING TO WATCH.
MODELS ARE PERSISTENT WITH BRINGING IN FREEZING TEMPERATURES TO THE
NORTHWEST LATE WEDNESDAY NIGHT INTO THURSDAY MORNING...WHILE
CONTINUING PRECIPITATION. STILL THINK TEMPS MAY BE A BIT ON THE
COOLER SIDE SO HAVE ADJUSTED UPWARD A BIT...BUT THIS STILL LEAVES
SOME LOW TEMPS AT OR BELOW FREEZING THURSDAY MORNING. BUFR
SOUNDING AT KCHA SHOWS A BRIEF PERIOD OF FREEZING RAIN WEDNESDAY
NIGHT FOLLOWED BY SLEET AND THEN SNOW BY 12Z THURSDAY AS THE
COLUMN COOLS. THE BUFR SOUNDING AT BRASSTOWN IS SIMILAR BUT
SLIGHTLY DELAYED AND KEEPS THE POTENTIAL FOR SNOW INTO MID
THURSDAY MORNING. GIVEN THIS AND SURFACE TEMPS...HAVE GONE AHEAD
AND MENTIONED SNOW/SLEET LATE WEDNESDAY NIGHT INTO THURSDAY
MORNING FOR PARTS OF NORTH GEORGIA...MAINLY THE NW. WILL NEED TO
WATCH THIS TIME PERIOD CLOSELY AS THE GFS BUFR SOUNDING EVEN HINTS
AT BRINGING SOME FREEZING RAIN TRANSITIONING TO SLEET INTO THE
METRO AREA THURSDAY MORNING. TEMPS ARE A LITTLE TOO WARM TO
MENTION IT THAT FAR SOUTH IN THE GRIDS YET...BUT AGAIN SOMETHING
THAT NEEDS TO BE WATCHED CLOSELY.
PRECIP SHOULD PUSH OUT BY FRIDAY AND HAVE LEANED TOWARDS THE DRIER
GFS FOR THE REMAINDER OF THE LONG TERM.
PREVIOUS LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... WARM PATTERN
STILL APPEARS TO BE IN STORE FOR THE REGION TO START OUT THE
EXTENDED FORECAST PERIOD AS UPPER-LEVEL FLOW BECOMES STRONG
SOUTHWESTERLY AHEAD OF THE WESTERN U.S. TROUGH. CANNOT RULE OUT SOME
CHANCE FOR PRECIPITATION MONDAY NIGHT THROUGH TUESDAY NIGHT WITH
AMPLE MOISTURE AND THE POTENTIAL FOR WEAK MID/UPPER-LEVEL SHORT
WAVES EJECTING FROM THE DEEP TROUGH. HOWEVER THE LACK OF LOW-LEVEL
FORCING AND THE UNCERTAIN NATURE OF THE TIMING ANY OF THESE
TRANSIENT MID/UPPER FEATURES LEADS ME TO KEEP POPS CHANCE AT BEST
THROUGH THAT TIME FRAME. STRONG SURFACE TROUGH ASSOCIATED WITH THE
APPROACHING UPPER TROUGH WEDNESDAY THROUGH WEDNESDAY NIGHT BRINGS
THE BEST CHANCES FOR ORGANIZED PRECIPITATION TO THE FORECAST AREA
WITH SUFFICIENT INSTABILITY FOR AT LEAST SCATTERED THUNDERSTORMS.
INSTABILITY IS WANING SOME AS THE FRONT PUSHES IN BUT IS HIGH ENOUGH
WHEN COMBINED WITH RELATIVELY STRONG LOW/MID-LEVEL WINDS TO KEEP US
ON OUR TOES FOR AT LEAST SOME MARGINAL ISOLATED SEVERE POTENTIAL.
STILL TOO UNCERTAIN TO INCLUDE ANY MENTION RIGHT NOW. GFS...AND TO A
LESSER EXTENT THE ECMWF...CONTINUE TO BRING IN FAIRLY COLD AIR INTO
THE FORECAST AREA WEDNESDAY NIGHT WHILE KEEPING SOME LIGHT QPF OVER
THE REGION THROUGH THURSDAY. WITH THE MAIN UPPER TROUGH LIFTING AND
FILLING SOME AS IT SWEEPS THROUGH I AM STILL A BIT LEARY THAT THE
BEST COLD AIR WILL MAKE TOO BIG OF AN INTRUSION INTO THE AREA VS
GETTING SHUNTED OFF TO THE EAST. I HAVE BEEN LEANING TOWARD THE
SLIGHTLY WARMER AND DRIER ECMWF THE PAST FEW RUNS AND AM INCLINED TO
CONTINUE THAT TREND IN LIGHT OF THE LATEST COUPLE OF RUNS OF THE GFS
ALSO SHOWING THIS SAME TREND IN FLATTENING THE FLOW ACROSS THE
REGION IN THE WAKE OF THE LIFTING UPPER TROUGH.
20
&&
.AVIATION...
06Z UPDATE...
LOW CIGS AND DRIZZLE EXPECTED TO HANG AROUND UNTIL AT LEAST MID
MORNING...WHEN A WEAK FRONT BEGINS TO APPROACH THE NORTHERN
TERMINAL SITES. THE FRONT LOOKS TO STALL AND WASH OUT SOMEWHERE
ACROSS NORTHERN GA LATER TODAY AND TONIGHT. HRRR HAS BACKED OFF ON
THE ORGANIZED SHOWERS ALONG/AHEAD OF THE FROPA...SO HAVE REMOVED
THE PROB30 FOR SHOWERS DURING THE MIDDAY PERIOD. MAY HAVE A BRIEF
PERIOD OF IFR CIGS DURING THE AFTERNOON...BUT DO EXPECT CIGS TO GO
BACK BELOW 010 AFTER DARK. WINDS ARE GOING TO BE LIGHT AND
VARIABLE WITH THE WEAK FRONT/TROUGH OVERHEAD. GENERALLY...WINDS
SHOULD TRY TO SWITCH AROUND TO THE NW BY EARLY AFTERNOON.
OVERNIGHT...A SWITCH TO THE NE IS POSSIBLE AS THE SURFACE HIGH
MOVES OFFSHORE.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 61 46 52 51 / 30 50 50 40
ATLANTA 55 45 61 56 / 30 50 40 40
BLAIRSVILLE 55 42 50 46 / 60 50 60 60
CARTERSVILLE 50 42 59 53 / 50 40 50 50
COLUMBUS 61 50 74 59 / 30 30 30 20
GAINESVILLE 52 43 50 49 / 40 50 60 50
MACON 61 53 70 58 / 20 30 30 20
ROME 50 42 61 54 / 60 40 60 60
PEACHTREE CITY 55 47 65 56 / 30 40 40 30
VIDALIA 65 56 71 60 / 20 20 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
1230 AM EST MON MAR 2 2015
.UPDATE...
ISSUED AT 911 PM EST SUN MAR 1 2015
UPDATED FORECAST TO TOSS IN SOME FOG THROUGH THE OVERNIGHT HOURS
AS SOME LOCALLY DENSE FOG HAS DEVELOPED. WILL ALSO UPDATE THE ZFP
AND HWO TO INCLUDE A MENTION OF FOG. FREEZING RAIN THREAT APPEARS
TO BE MINIMAL AS BEST RETURNS WILL LIKELY OCCUR WELL AHEAD OF
AREAS WHERE TEMPERATURES ARE REACHING THE FREEZING MARK.
THUS...WILL LIMIT THE FORECAST TO JUST RAIN OR SNOW FOR THE
REMAINDER OF THE NIGHT. AGAIN...ANY SNOW WILL BE MINOR AND HAVE
VERY LITTLE IMPACT. IN FACT...LATEST OBS ARE HANGING UP MUCH
HIGHER THAN EXPECTED TO THIS POINT...WITH MID TO UPPER 30S STILL
BE REPORTED ACROSS THE NORTHERN PORTION OF THE AREA WITH LOW TO
MID 40S TO THE SOUTH.
UPDATE ISSUED AT 641 PM EST SUN MAR 1 2015
UPDATED TO REMOVE POPS THROUGH THE EVENING AS WE REMAIN DRY
SLOTTED. HOWEVER...THE COLD FRONT...CURRENTLY PUSHING SOUTH ACROSS
NORTHERN KENTUCKY WILL SLIP SOUTH LATER THIS EVENING AND
OVERNIGHT. AS THIS HAPPENS...A MID LEVEL WAVE WILL PUSH EAST WITH
MOISTURE RAPIDLY INCREASING ALONG THE FRONTAL ZONE. THIS WILL MEAN
INCREASING PRECIPITATION CHANCES INTO THE OVERNIGHT HOURS. AS THE
FRONT SLIPS SOUTH...PRECIPITATION WILL END FROM NORTH TO SOUTH
THROUGH THE OVERNIGHT HOURS. PRECIPITATION WILL LIKELY HOLD ON THE
LONGEST IN SOUTHEAST KENTUCKY. ADJUSTED THE POPS TO REFLECT THE
HIGHEST PRECIPITATION CHANCES (CATEGORICAL) IN SOUTHEAST
KENTUCKY...TRAILING OFF TO JUST CHANCE IN THE NORTH...WHERE THE
FRONT WILL PUSH THROUGH MUCH FASTER THIS EVENING. HRRR CONTINUES
TO SHOW A GOOD HANDLE ON PRECIPITATION COVERAGE THIS EVENING...SO
WILL CONTINUE TO FOLLOW IT FAIRLY CLOSELY WITH EXPECTED ARRIVAL OF
MORE WIDESPREAD PRECIPITATION OVERNIGHT. THE PATTERN WOULD SUGGEST
TEMPERATURES WILL HAVE A TOUGH TIME COOLING FAST ENOUGH TO ALLOW
FOR MUCH FREEZING RAIN AND WITH GROUND TEMPERATURES FAIRLY WARM
GOING INTO THINGS TONIGHT...NOT NEARLY AS CONCERNED ABOUT ICING
TONIGHT. HOWEVER...THE CONVECTIVE NATURE OF THE HRRR WOULD SUGGEST
SOME PRECIPITATION RATES COULD GET FAIRLY GOOD LATER
TONIGHT...PERHAPS ALLOWING A QUICK CHANGEOVER TO SNOW IN THE
HEAVIER SHOWERS. THIS WOULD SEEM REASONABLE AND WILL HAVE TO WATCH
FOR THIS AS THIS COULD PUT DOWN A QUICK COATING OF SNOW IN SOME
AREAS...LEADING TO SOME SLICK ROADS. AT THE SAME
TIME...TEMPERATURES ARE NOT EXPECTED TO FALL MUCH BELOW FREEZING
FOR MUCH OF THE AREA...SO ANY SNOW MAY NOT LAST ON ROADS GIVEN THE
WARMTH TODAY. THUS...IT MAY JUST BE A VERY SHORT TERM ISSUE TO
CONTEND WITH OVERNIGHT FOR THOSE DRIVING ACROSS EASTERN
KENTUCKY...ESPECIALLY SOUTHEAST KENTUCKY. WE MAY CONSIDER DOING A
SHORT TERM SPS IF THE HEAVIER SNOW BURSTS APPEAR TO BE MORE LIKELY
LATER ON. ALL FORECAST CHANGES HAVE BEEN INCORPORATED INTO THE
UPDATE WITH THE MAIN IMPACTS TO JUST HAVE LESS FREEZING RAIN
POTENTIAL.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 320 PM EST SUN MAR 1 2015
ZONAL FLOW WILL HOLD ON THROUGH THE NIGHT AS A WEAK SURFACE BOUNDARY
FINALLY SHIFTS EASTWARD AND OUT OF THE REGION BY 12Z MONDAY MORNING.
THIS WILL LEAD TO CONTINUED RAIN CHANCES LATE THIS AFTERNOON AND
EVENING...POSSIBLY MIXING WITH SOME FREEZING RAIN AND EVENTUALLY
SNOW BEFORE TAPERING OFF MONDAY MORNING/EARLY AFTERNOON. AS ROAD
TEMPERATURES WARM THROUGHOUT TODAY...EXPECT THEM TO LAG BEHIND THE
AIR TEMPERATURE FALLING OVERNIGHT BY AT LEAST AN HOUR OR
TWO...THOUGH A FAIRLY STRONG WARM NOSE EXISTS BETWEEN 6 AND 12Z
ACROSS EASTERN KY. EXPECT THE FREEZING RAIN TO OCCUR AS THE RAIN IS
SWITCHING OVER TO SNOW...WITH SOME MIXING POSSIBLE THROUGH 12Z. MOST
OF THE IMPACTS WILL LIKELY BE OVER THE NORTHER HALF OF THE
CWA...WHERE TEMPS WILL BE THE COLDEST.
UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE IS EXPECTED TO TAKE
HOLD DURING THE DAY TOMORROW. DRY AIR WILL QUICKLY CUT OFF ANY
LINGERING PRECIP BY LATE TOMORROW MORNING ACROSS EASTERN KY...AND
ALLOW FOR SOME BREAKING UP OF THE ONGOING CLOUD COVER. UNDER LIGHT
WINDS...AND WITHOUT THE INFLUENCE OF THE SOUTHERLY FLOW WE HAD
TODAY...EXPECT TEMPS TO BE SLIGHTLY COOLER IN THE AFTERNOON...ONLY
REACHING THE UPPER 30S TO LOW 40S. THIS SYSTEM WILL BE VERY SHORT
LIVED UNFORTUNATELY...AS THE HIGH PRESSURE QUICKLY SHIFTS EAST OF
THE REGION BY 6Z TUESDAY...WINDS BECOME MORE SRLY ONCE MORE...AND WE
START TO SEE THE INFLUENCES OF OUR NEXT APPROACHING SYSTEM.
CLOUDS WILL BE INCREASING THROUGHOUT THE NIGHT TUESDAY NIGHT...AS A
SURFACE LOW PRESSURE SYSTEM APPROACHES FROM THE CENTRAL
PLAINS...FOLLOWING THE UPPER LEVEL RIDGING PATTERN AND SHIFTING
NORTH EASTWARD THROUGH THE DAY TUESDAY. WITH STRONG SRLY FLOW
PULLING IN DECENT GULF MOISTURE...EXPECT PRECIP TO BEGIN WELL AHEAD
OF THIS SYSTEM...WITH POPS EXPECTED IN EASTERN KY AS EARLY AS LATE
TUESDAY NIGHT. THOUGH SURFACE TEMPS WILL REMAIN NEAR OR BELOW
FREEZING BY TUESDAY MORNING...THIS STRONGER SRLY FLOW WILL INTRODUCE
AN IMPRESSIVELY LARGE WARM NOSE INTO THE LOWER LEVELS. ONCE
AGAIN...THIS LOOKS LIKE A GOOD SET UP FOR SOME FREEZING RAIN AT THE
ONSET THROUGH 12Z...EVENTUALLY CHANGING TO ALL RAIN AS TEMPS CONTINUE
TO WARM AT THE SURFACE AND ALOFT THROUGH THE DAY TUESDAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 355 PM EST SUN MAR 1 2015
THE MODELS REMAIN IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE
PATTERN CONTINUING TO RULE ACROSS THE CONUS THROUGH THE END OF THE
WORKWEEK...BEFORE DAMPENING A BIT NEXT WEEKEND. A POSITIVELY
TILTED TROUGH OUT WEST WILL RESULT IN DEEP SOUTHWEST FLOW SETTING
UP ACROSS THE MISSISSIPPI VALLEY. THIS WILL ALLOW FOR A STOUT
BAROCLINIC ZONE TO MEANDER THROUGH THE OHIO AND TENNESSEE VALLEYS
THROUGH THE MIDDLE OF THE WEEK...WITH MUCH WARMER AND WETTER AIR
BEING ADVECTED INTO THE REGION. ANOTHER SHARP COOL DOWN WILL
FOLLOW...WITH ANY LINGERING PRECIPITATION GOING OVER TO SNOW
BEFORE ENDING THE WEEK MUCH COLDER AND DRIER.
DETAILS ON WHERE THE AXIS OF HEAVIER PRECIPITATION SETS UP AND
LINGERS WILL LIKELY CONTINUE TO VARY OVER THE COMING DAYS. AS
SUCH...HAVE CONTINUED TO STICK TO A GENERAL BLEND OF THE
SOLUTIONS...INCLUDING THE QPF AMOUNTS. IN GENERAL...THE MODELS
CONTINUE TO PAINT 2 TO 3 INCHES OF PRECIPITATION ACROSS THE AREA
BETWEEN TUESDAY AFTERNOON AND THURSDAY MORNING. THE BULK OF THIS
WILL FALL TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...WITH HEAVIER
AMOUNTS STARTING OUT IN THE NORTHWEST...AND THEN EVENTUALLY
SPREADING TO THE SOUTHEAST WITH TIME. THIS WILL BE MORE THAN
ENOUGH TO CAUSE FLOODING CONCERNS AND WILL CONTINUE TO HIGHLIGHT
THIS THREAT IN AN ONGOING HYDROLOGIC OUTLOOK.
PRECIPITATION MAY START OUT AS A WINTRY MIX OF FREEZING RAIN AND
RAIN FOR THE NORTHEAST PORTION OF THE AREA EARLY TUESDAY...
BEFORE QUICKLY GOING OVER TO JUST RAIN AS MUCH WARMER AIR ADVECTS
INTO THE REGION. A SURFACE WARM FRONT WILL LIFT THROUGH DURING THE
DAY...WITH THE BETTER RAINFALL AMOUNTS LIKELY FALLING WEST OF I-75
AND NEAR THE I-64 CORRIDOR...AS SOME DOWNSLOPING MAY CUT INTO
TOTALS TO THE SOUTHEAST. THE COLD FRONT WILL FOLLOW AND VERY
GRADUALLY SLIDE SOUTHEAST THROUGH THE AREA TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...PROVIDING THE BULK OF THE HEAVIER RAINFALL.
MUCH COLDER AIR WILL MOVE IN WEDNESDAY NIGHT INTO THURSDAY BEHIND
THE FRONT...WITH ANY LINGERING PRECIPITATION GOING OVER TO
SNOW...WITH SOME LIGHT ACCUMULATIONS POSSIBLE. SOME OF THE MODELS
ARE INDICATING THAT THE COLD AIR WILL MAKE IT IN BEFORE THE DEEPER
MOISTURE EXITS...IN PARTICULAR THE ECMWF...RESULTING IN THE
POTENTIAL FOR A GOOD WINDOW OF HEAVY WET SNOW. THIS IS NOT A
TYPICAL OUTCOME FOR THIS PATTERN...BUT WILL STILL NEED TO BE
WATCHED IN THE COMING DAYS.
AFTER ENJOYING HIGHS IN THE 50S TUESDAY AND WEDNESDAY...READINGS
WILL FALL BACK INTO THE 20S AND 30S FOR THURSDAY...WITH LOWS
BOTTOMING OUT NEAR THE 10 DEGREE MARK FRIDAY MORNING. HIGHS WILL
RETURN TO THE 40S FOR SATURDAY AND SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1230 AM EST MON MAR 2 2015
NEAR LIFR CIGS WILL CONTINUE AS RAIN SHOWERS PUSH SOUTH ACROSS
EASTERN KENTUCKY OVERNIGHT. THIS WILL ESSENTIALLY PUT CIGS AT OR
BELOW AIRPORT MINIMUMS THROUGH MUCH OF THE NIGHT WITH LITTLE
IMPROVEMENT EXPECTED. VISIBILITIES WILL ALSO BE SHARPLY REDUCED
AT TIMES DUE TO THE PRECIPITATION AND SOME FOG THAT HAS BEGUN TO
FORM ACROSS THE AREA...MEANING THERE WILL ALSO BE A GOOD CHANCE
THAT VSBYS WILL FALL BELOW AIRPORT MINIMUMS AT TIMES. CIGS SHOULD
BREAK UP AND LIFT TOMORROW MORNING AS THE FRONTAL BOUNDARY SHIFTS
SOUTH OF THE AREA. THIS WILL ALLOW FOR A RETURN TO VFR CONDITIONS
BY MIDDAY TOMORROW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...AR
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1223 AM EST MON MAR 2 2015
.SYNOPSIS...
LOW PRESSURE WILL APPROACH THE REGION FROM OHIO VALLEY THIS
EVENING AND MOVING THROUGH THE REGION LATER TONIGHT INTO MONDAY.
THIS SYSTEM WILL BRING SOME SNOW TO THE FORECAST AREA. HIGH
PRESSURE WILL BUILD TOWARD THE AREA MONDAY NIGHT AND TUESDAY FROM
THE WEST. ANOTHER LOW WILL CROSS THE REGION WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATE...A WEAK AREA OF LOW PRES WILL PASS SOUTH OF THE GULF OF
MAINE OVERNIGHT AND INTENSIFY RAPIDLY MON MORNING AS IT BEGINS TO
LIFT OUT ACROSS THE MARITIMES. SNOW IS FALLING ACROSS SOUTHERN
MAINE AND WILL OVERSPREAD THE DOWN EAST REGION OVER THE NEXT 1 TO
2 HOURS. THE LATEST RAP AND HRRR HAVE MOST OF THE SNOW OUT OF THE
AREA BY 10Z AND THIS LOOKS REASONABLE BASED ON THE LATEST RADAR
TRENDS. AREAS ALONG THE COAST WILL PICK UP THE MOST SNOWFALL WITH
AMOUNTS DROPPING OFF TO THE NORTH AND WEST. EXPECT SOME SPOTS
ALONG AND NEAR THE COAST MAY PICK UP A FEW INCHES OF SNOW...BUT
UNLIKELY THAT MANY AREAS RECEIVE ADVISORY LEVEL SNOWFALL. WILL
MAINTAIN THE CURRENT ADVISORIES BUT SUSPECT THE MIDNIGHT SHIFT
WILL BE ABLE TO TAKE THEM DOWN EARLY IN THE MORNING. ALSO MADE
SOME TWEAKS TO RAISE THE HOURLY TEMPS AND OVERNIGHT LOWS A FEW
DEGREES.
PREVIOUS DISCUSSION...
THINGS TO FOCUS ON THIS TERM WILL BE SNOWFALL AMOUNTS AND SNOW
SQUALL POTENTIAL ON MONDAY.
18Z SURFACE ANALYSIS SHOWED HIGH PRES S OF THE REGION RIDGING
ACROSS THE STATE OF MAINE. MID AND HIGH CLOUDS MOVING NE PER THE
LATEST SATELLITE IMAGERY WILL CAP ANY FURTHER PROGRESSION OF
TEMPERATURES THIS AFTERNOON. READINGS ACROSS NORTHERN AND WESTERN
AREAS HIT THE MID/UPPER 20S WHILE CENTRAL AND DOWNEAST CLOSED IN
AROUND 30. TEMPERATURES WILL FALL BACK AFTER SUNSET BUT W/THE
CLOUDS MOVING IN, ANY FURTHER DROP WILL BE SLOW OR EVEN READINGS
LEVELING OFF ESPECIALLY DOWNEAST AND THE COAST. NORTHERN AREAS
COULD SEE TEMPERATURES FALL OFF QUICKER AS INITIAL CLOUD SHIELD IS
THIN PER THE OBS. SNOW IS FORECAST TO BREAK OUT ACROSS THE
SOUTHERN AND DOWNEAST AREAS THIS EVENING. THE LATEST RUNS OF THE
RAP AND HRRR 3KM DOING WELL PER THE RADAR TRENDS AND METARS. THIS
SET OF GUIDANCE SHOWS SNOW SETTING UP LATER THAN PREVIOUSLY
EXPECTED. THEREFORE, PULLED BACK ON THE TIMING BY A FEW HRS. LOW
PRES MOVING E FROM THE OHIO VALLEY IS SHOWN BY THE MODEL GUIDANCE
TO RE-DEVELOP OFF THE MAINE COAST LATER TONIGHT W/AN INVERTED TROF
SETTING UP FOR A TIME ACROSS EASTERN SECTIONS. SOME FORCING IS
THERE AND W/TEH LLVL CONVERGENCE, THERE COULD BE A BRIEF PERIOD OF
MODERATE SNOW WHERE RATIOS OF 15-20:1 COULD BE REALIZED W/2-4 INCHES
OF SNOW FROM 06-12Z. THE HIGHEST SNOWFALL WILL BE ACROSS THE COAST
AND GIVEN THE 3-4 INCH AMOUNTS SHOWN, DECIDED TO ISSUE A WINTER
WEATHER ADVISORY FOR SNOW. THIS WAS COORDINATED W/GYX. FURTHER N
AND W, SNOWFALL AMOUNTS WILL DROP OFF AS DYNAMICS WILL BE WEAKER
W/A GENERAL 1-3 INCHES AT BEST.
FOR MONDAY, SNOWFALL WILL COME TO AN END QUICKLY ACROSS THE W AND
DOWNEAST REGION WHILE EASTERN AREAS INCLUDING EASTERN SECTION OF
AROOSTOOK COUNTY WILL HANG ON TO A PERIOD OF SNOW THROUGH 10 AM
OR SO. THINGS WILL TRANSITION TO A MORE SHOWERY NATURE FOR THE
SNOW W/A GOOD CHANCE FOR SOME SNOW SQUALLS. THE NAM AND GFS
SOUNDINGS POINT TO STEEPENING LAPSE RATES(6/5-7.0C/KM) AT
850-700MBS AND FORECAST CAPE OF 70+ JOULES. THIS WILL BE IN
ASSOCIATION W/AN ARCTIC FRONT THAT IS FORECAST TO SLIDE ACROSS THE
REGION MONDAY AFTERNOON. THE BTV SNOW SQUALL PARAMETER SHOWED 2
AREAS OF SQUALL POTENTIAL W/ONE ACROSS NORTHERN AND WESTERN AREAS
AND THE SECOND AREA ACROSS EASTERN MAINE. TEMPERATURES WILL DROP
OFF SHARPLY BEHIND THIS BOUNDARY AFTER 19Z(2 PM). A QUICK INCH OF
SNOW CAN BE EXPECTED W/THE SQUALLS ALONG W/WIND GUSTS UP TO 30
MPH. THIS SITUATION IS SIMILAR TO THE SQUALL EVENT THAT OCCURRED A
WEEK AGO(2/23)WHERE MOIST OFF THE OPEN ST. LAWRENCE COMBINED W/THE
FRONT AIDING IN SOME HEFTY SNOW SQUALLS/SNOW SHOWERS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
THE MAIN FORECAST CONCERN FOR THE SHORT TERM IS A QUICK MOVING
SHORTWAVE WHICH WILL AFFECT MOST OF NEW ENGLAND TUESDAY NIGHT INTO
WEDNESDAY. THE COMBINATION OF DPVA AND WAA WILL PROVIDE SUFFICIENT
LIFT TO PRODUCE LIGHT TO MODERATE SNOW ACROSS OUR CWA DURING THIS
TIME FRAME...WITH CONDITIONS EXPECTED TO DRY OUT QUICKLY WEDNESDAY
AFTERNOON. HAVE FOLLOWED CLOSELY TO CONSALL QPF WHICH RESULTS IN
A GENERAL 3 TO 5 INCHES OF SNOWFALL. THE HIGHEST AMOUNTS WILL
OCCUR DOWNEAST...BUT WITH TEMPS IN THE LOWER 40S WEDNESDAY
AFTERNOON...MUCH OF THE SNOW WILL COMPACT OR MELT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE UPPER LEVEL FLOW WILL BECOME ZONAL AND PROGRESSIVE DURING THE
EXTENDED FORECAST PERIOD...BRINGING A SERIES OF VERY WEAK
SHORTWAVES ACROSS THE NORTHEAST. THIS WILL RESULT IN SEASONABLY
COLD CONDITIONS WITH OCCASIONAL SNOW SHOWERS.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR DROPPING TO MVFR LATE THIS EVENING AND THEN IFR TO
LOW END MVFR OVERNIGHT FOR ALL TERMINALS. CONDITIONS ARE FORECAST
TO IMPROVE TO VFR FOR KBGR AND KBHB MIDDAY MONDAY W/THE NORTHERN
TERMINALS GOING FROM IFR TO MVFR.
SHORT TERM: MVFR TO IFR CONDITIONS SHOULD PREVAIL ACROSS THE CWA
TUESDAY NIGHT INTO WEDNESDAY MORNING IN ASSOCIATION WITH THE
AFOREMENTIONED SNOWFALL. CONDITIONS WILL IMPROVE WEDNESDAY
AFTERNOON.
&&
.MARINE...
NEAR TERM: PER COORDINATION W/GYX, DECIDED TO GO W/A GALE WARNING
FOR MONDAY AFTERNOON INTO THE EVENING DUE TO THE ARCTIC FRONT
MOVING ACROSS THE WATERS. NW WINDS W/CAA WILL ALLOW FOR WINDS TO
HIT 25 TO 30 W/GUSTS UP TO 35 KTS. BUFKIT PROFILES SHOW GUST
POTENTIAL TO 40 KTS OVER THE OUTER WATERS. MIDNIGHT CREW HAD THIS
HANDLED WELL AND STAYED CLOSE TO IT.
SHORT TERM: A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FOR OUR
COASTAL MARINE ZONES TUESDAY NIGHT INTO WEDNESDAY AS STORM SYSTEMS
CROSSES THE AREA...CREATING BREEZY SOUTHWEST WINDS AND HIGH WAVES.
&&
.CLIMATE...
FEBRUARY ENDED AS THE ALL-TIME COLDEST MONTH ON RECORD
AT BANGOR AND THE COLDEST FEBRUARY ON RECORD AT CARIBOU. MORE
INFORMATION ON THE RECORD COLD MONTH IS AVAILABLE ON THE NEWS
HEADLINES ON THE TOP OF OUR WEB PAGE AT: WEATHER.GOV/CAR
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MEZ029-030.
MARINE...GALE WARNING FROM 3 PM THIS AFTERNOON TO 4 AM EST TUESDAY FOR
ANZ050>052.
&&
$$
NEAR TERM...CB/HEWITT/MCW
SHORT TERM...BERDES
LONG TERM...BERDES
AVIATION...CB/HEWITT/MCW/BERDES
MARINE...CB/HEWITT/MCW/BERDES
CLIMATE...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
450 AM EST MON MAR 2 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM EST MON MAR 2 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW OVER
NAMERICA WITH ARCTIC BRANCH TROF EXTENDING FM HUDSON BAY INTO THE
GREAT LKS. SHRTWV/AREA OF SOME LO/MID CLDS ASSOCIATED WITH SOME MSTR
BTWN H9 AND H7 SHOWN ON THE 00Z INL RAOB ARE PASSING THRU UPR MI
EARLY THIS MRNG. IN CONCERT WITH THE COLD NW LLVL FLOW E OF HI PRES
RDG SHIFTING INTO MN THAT IS ADVECTING H85 TEMPS AS LO AS -18C TO
-19C INTO THE AREA...SOME SCATTERED SN SHOWERS ARE IMPACTING UPR MI
DESPITE EXTENSIVE ICE COVER ON LK SUP. THE MOST NMRS SN SHOWERS
APPEAR TO BE OVER THE W TO THE S OF HOUGHTON AND OVER ALGER
COUNTY...LOCATIONS THAT ARE DOWNWIND OF WIDER BREAKS IN THE ICE
COVER OVER WRN LK SUP NEAR THE MN ARROWHEAD/E OF THE BAYFIELD
PENINSULA AND OVER AN AREA TO THE E OF THE KEWEENAW. LOOKING TO THE
NW...THERE IS A SHRTWV RDG WITHIN THE ARCTIC BRANCH MOVING E OVER
SCENTRAL CANADA SUPPORTING THE SFC HI MOVING INTO MN. 12HR H5 HGT
RISES UP TO 100-120M HAVE BEEN OBSVD UNDER THE NVA AHEAD OF THIS
FEATURE. WITHIN THE SRN BRANCH...THERE IS A CUTOFF LO MOVING OFF THE
PACIFIC INTO SRN CA.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS INTO THIS MRNG
AND THEN ANTICIPATED CLRG WITH APRCH OF SHRTWV RDG/SFC HI PRES.
FOCUS FOR LATER TNGT WL SHIFT TOWARD POPS ASSOCIATED WITH DVLPG WAA
BTWN SFC HI PRES SHIFTING TO THE E AND FALLING MSLP TO THE W IN
ADVANCE OF SRN BRANCH SHRTWV LIFTING INTO THE PLAINS AND DEEPENING
ARCTIC BRANCH TROF INTO THE NRN PLAINS.
TODAY...WITH APRCH OF SHRTWV RDG AXIS/SFC HI PRES THIS MRNG...
MODELS SHOW H5 HGT RISES UP TO 180M BTWN 06Z-18Z. SHARPENING/
LOWERING SUBSIDENCE INVRN TO AOB 3K FT AGL AND INCRSGLY ACYC H925
FLOW SHOULD RESULT IN STEADY DIMINISHING TREND TO THE LES W-E WITH
ACTIVITY OVER THE E ENDING BY NOON. AS SKIES TURN MOSUNNY THIS AFTN
WITH RDG AXIS SHIFTING E ACRS THE CWA...EXPECT TEMPS TO TOP OUT IN
THE 20S WITH MIXING TO H85-875.
TNGT...AS SHRTWV RDG EXITS TO THE E...SFC HI PRES IS FCST TO DRIFT
INTO NEW ENGLAND. INCRSG SW FLOW BTWN THE DEPARTING HI AND FALLING
MSLP FM NW ONTARIO THRU THE PLAINS IN ADVANCE OF DIGGING SHRTWV THAT
WL BE DEEPENING THE ARCTIC BRANCH TROF IN SCENTRAL CANADA AND SHRTWV
LIFTING NE INTO THE PLAINS FM SRN BRANCH CUTOFF LO NOW OVER SRN CA
WILL BRING WAA/ISENTROPIC ASCENT BACK TO THE UPR LKS. THE MAJORITY
OF THE MODELS SHOW A BAND OF LGT PCPN UP TO 0.05 TO 0.10 INCH BY 12Z
NEAR THE WI BORDER WELL TO THE N OF H85 WARM FNT ASSOCIATED WITH SRN
BRANCH LO PRES CENTER FCST TO TAKE SHAPE IN THE CENTRAL PLAINS. THIS
BAND OF PCPN APPEARS TO BE RELATED TO HIER LVL FGEN IN THE H7-5 LYR
AND MID LVL MOISTENING WITH H7 SPECIFIC HUMIDITY FCST TO INCRS UP TO
2 G/KG BY 12Z. BUT POPS/PCPN AMNTS WL BE LIMITED BY LINGERING LOWER
LVL DRY AIR AS WELL AS PRESENCE OF SHARPER DEEP LYR QVECTOR STILL
FARTHER TO THE SW. GIVEN THE LINGERING LLVL DRY AIR AND FCST SHARPER
DYNAMIC SUPPORT/H85 WARM FNT/ISENTROPIC ASCENT TO THE SW...WENT NO
HIER THAN HI CHC POPS LATE NEAR THE WI BORDER ATTM. EXPECT THE
LOWEST MIN TEMPS OVER THE E CLOSER TO RETREATING HI PRES/CORE OF
DRIER AIR.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 331 AM EST MON MAR 2 2015
PRIMARY IMPACT IN THE LONG TERM WILL BE TUE AS MODERATE SNOW MOVES
THROUGH THE AREA.
AT 12Z TUE A NRN STREAM SYSTEM WILL BE OVER NRN MANITOBA WHILE A SRN
STREAM SYSTEM IS OVER THE CENTRAL PLAINS. LIGHT SNOW SHOULD BE
ONGOING LATE MON NIGHT INTO TUE MORNING...MAINLY OVER THE SRN/SWRN
CWA. SRN STREAM ENERGY STAYS MAINLY S OF THE CWA ON TUE AS THE NRN
STREAM SYSTEM MOVES INTO FAR NRN ONTARIO. GENERALLY MODERATE SNOW
WILL FALL ACROSS MOST OF THE REGION IN THE BROAD AREA OF
WAA/ISENTROPIC ASCENT ALONG WITH LARGER SCALE FORCING AS THE TROUGH
MOVES IN FROM THE W. SNOW RATIOS SHOULD BE BETWEEN 15-1 AND 18-1
AS TEMP PROFILES DO NOT SHOW THE DGZ BEING PARTICULARLY DEEP...BUT
DEEP ENOUGH TO KEEP RATIOS FROM BEING AS LOW AS 10-1. GENERALLY
PREFER A BLEND OF MODEL QPF FROM THE 00Z/02 GFS...12Z/01
ECMWF...00Z/02 NAM/NAM DNG...00Z/02 REGIONAL GEM AND 00Z/02 CONSALL.
THESE MODELS ARE IN GENERAL AGREEMENT ON QPF AMOUNTS...BUT THERE IS
STILL SOME DIFFERENCES...LIKELY DUE TO CHALLENGES OF SYSTEM PHASING.
PREFERRED MODEL BLEND GIVES QPF AMOUNTS OF 0.20-0.28
INCHES...RESULTING IN SNOWFALL AMOUNTS RANGING FROM AROUND 2.5
INCHES SCENTRAL TO 3-5 INCHES ELSEWHERE. LOOKING AT THE HIGHER END
OF PREFERRED GUIDANCE...QPF AMOUNTS UP TO 0.35 INCHES ARE NOT OUT OF
THE QUESTION...WHICH WOULD ALLOW FOR QPF AMOUNTS UP TO 5-6 INCHES.
THE LOW END OF PREFERRED GUIDANCE WOULD RESULT IN 2-3.5 INCHES OF
SNOW. LOOKING LIKE AN ADVISORY WILL BE NEEDED FOR TUE AS MOST OF THE
SNOW FALLS IN LESS THAN 12 HOURS DURING THE DAY AND CRITERIA IS 3-6
INCHES. WILL ALLOW THE DAY SHIFT TO TAKE ANOTHER LOOK AT THINGS
GIVEN VARIABILITY OF EXACT AMOUNTS AND PLACEMENT DUE TO COMPLEXITIES
OF SYSTEM PHASING.
WITH 850MB TEMPS AS WARM AS -9C ON TUE...SFC HIGH TEMPS WILL BE IN
THE MID TO UPPER 20S. ANOTHER COLDER PERIOD WILL FOLLOW THE PASSAGE
OF A STRONG COLD FRONT TUE AFTERNOON/EVENING AND A SECONDARY COLD
FRONT TUE NIGHT/WED MORNING. 850MB TEMPS WILL DECREASE TO A MINIMUM
OF -25C TO -30C WED INTO WED NIGHT. THIS WILL RESULT IN TEMPS
FALLING INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO BY LATE WED
MORNING...THEN INCREASING TO THE SINGLE DIGITS ABOVE ZERO DURING
PEAK HEATING WED AFTERNOON. SFC HIGH PRESSURE WILL START TO WORK
INTO THE AREA FROM THE W WED NIGHT...WHICH SHOULD ALLOW FOR VERY
COLD TEMPERATURES UNDER THE LINGERING COLD AIRMASS WITH LOWS WED
NIGHT FALLING TO AROUND -20 ALONG THE WI BORDER IN GOGEBIC AND IRON
COUNTIES. TEMPERATURE MODERATION WILL THEN OCCUR FRI THROUGH THE
WEEKEND.
WITH LAKE SUPERIOR NEARLY COMPLETELY ICE COVERED...LES
COVERAGE/INTENSITY IS SIGNIFICANTLY REDUCED...BUT SCATTERED LIGHT
LES IS EXPECTED TUE NIGHT INTO THU IN NW WIND SNOWBELTS. BLOWING
SNOW WILL BE AN ISSUE ALONG LAKE SUPERIOR AS WNW WINDS INCREASE
BEHIND THE COLD FRONTS...WITH GUSTS UP TO 40MPH POSSIBLE ALONG THE
SHORE LATE TUE INTO WED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1206 AM EST MON MAR 2 2015
WNW WINDS IN WAKE OF SFC LOW PRES TROF COULD RESULT IN SOME SCT -SHSN
AND TEMPORARY MVFR CIGS OVERNIGHT AT KIWD AND KCMX. ARRIVAL OF DRIER
AIR AND BACKING WINDS MON MORNING WILL BRING A RETURN OF VFR
CONDITIONS TO KIWD AND KCMX LATE MORNING. AT KSAW...EXPECT VFR
CONDITIONS TO PREVAIL TONIGHT THRU MON MORNING UNDER DOWNSLOPE WNW
FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EST MON MAR 2 2015
NW WINDS UP TO 30 KTS OVER EASTERN LAKE SUPERIOR EARLY WILL DIMINISH
QUICKLY THIS MORNING WITH ARRIVAL OF HI PRES RIDGE. LIGHT S WINDS
WILL THEN INCREASE UP TO 25 KTS ON TUE IN ADVANCE AN APPROACHING LO
PRES. ONCE THE LO PASSES TO THE E ON TUE NIGHT...TIGHTENING PRES
GRADIENT AND STRONG COLD AIR ADVECTION AHEAD OF ARCTIC HI PRES
MOVING INTO THE NORTHERN PLAINS WILL LIKELY BRING A PERIOD OF NW
GALES INTO WED. LATEST OFFICIAL ICE CONCENTRATION ON LK SUPERIOR IS
AROUND 95 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK...EXPECT
THE HIGHER ICE COVERAGE TO PERSIST AS TEMPERATURES STAY BELOW
FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
332 AM EST MON MAR 2 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 422 PM EST SUN MAR 1 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF EXTENDING FROM
HUDSON BAY INTO THE NRN PLAINS. WITHIN TROF...NEXT SHORTWAVE OF
INTEREST IS NOW OVER THE DAKOTAS/MN. CLOSER TO HOME...SOME
-SHSH/FLURRIES HAVE SPREAD FROM WRN UPPER MI INTO PORTIONS OF CNTRL
UPPER MI TODAY IN VCNTY OF SFC TROF WHICH IS NOW ROUGHLY BISECTING
UPPER MI.
TONIGHT...SHORTWAVE NOW OVER THE DAKOTAS WILL SWING ACROSS THE WRN
GREAT LAKES THIS EVENING. AREA OF DEEP LAYER FORCING PER QVECTORS
SHIFTS ACROSS UPPER MI LATE THIS AFTN AND EVENING. WITH ASSOCIATED
BRIEF PERIOD OF DEEP MOISTURE...850MB TEMPS AROUND -18C...AND A
ROUGHLY 3KFT DGZ LAYER BTWN ROUGHLY 2K AND 5KFT...WOULD NORMALLY BE
CONCERNED ABOUT SEEING SEVERAL HRS OF HEALTHY LAKE ENHANCED SNOW IF
THE LAKE WASN`T MOSTLY ICE COVERED. THAT SAID...THE BRISK SW TO W
WINDS OF THE LAST COUPLE OF DAYS HAVE OPENED UP SOME NOTABLE GAPS IN
THE ICE...SO THERE WILL BE AN OPPORTUNITY FOR LOCALIZED MORE
PERSISTENT LES AND SOME SNOW ACCUMULATION. FROM TODAYS MODIS AND VIS
SATELLITE IMAGERY...A COUPLE OF IMPORTANT GAPS IN THE ICE ARE NOTED
FROM AROUND THE HURON ISLANDS DOWN PAST GRANITE ISLAND AND OVER TO N
OF MUNISING...AND ALSO IN THE AREA E OF THE APOSTLE ISLANDS WHICH
HAS CERTAINLY HAD A TENDENCY TO OPEN UP OVER THE LAST FEW WEEKS WHEN
WINDS ARE SW. WILL THUS HIT HIGHEST POPS AND 1-2 INCHES OF SNOW
DOWNWIND OF THESE OPEN WATER AREAS THIS EVENING (JUST N OF IRONWOOD
TO THE PORCUPINE MTNS AND ALSO ALGER COUNTY). STRONG NEGATIVE
DYNAMICS TAKE OVER DURING THE OVERNIGHT...SO LES INTENSITY WILL
DIMINISH RATHER QUICKLY AFTER MIDNIGHT. AWAY FROM THESE AREAS...
WNW/NW FLOW LES SHOULD BE NO MORE THAN SCT WITH ACCUMULATIONS UNDER
1 INCH. ELSEWHERE...EXPECT SOME FLURRIES IN MOST AREAS AS SHORTWAVE
PASSES. TEMPS IN THE INTERIOR W TOWARD THE WI BORDER SHOULD FALL
DOWN TOWARD ZERO WITH CLEARING SKIES OVERNIGHT. OTHERWISE...MIN
TEMPS SHOULD BE WITHIN A FEW DEGREES OF 10F.
ANY LINGERING LES TO THE E OF MARQUETTE WILL END BY MON AFTN UNDER
WAA/BACKING WINDS WITH PASSAGE OF SFC HIGH PRES RIDGE (BY MID AFTN
850MB TEMPS ARE FCST TO BE AROUND -12C). WHILE THERE MAY BE SOME
STRATOCU DEVELOPMENT EVEN WHERE SKIES ARE CLEAR TO START THE
DAY...EXPECT ALL AREAS TO BECOME SUNNY DURING THE DAY WITH DRY AIR
MASS AND DEPARTURE OF 850MB THERMAL TROF. HIGH TEMPS WILL RANGE FROM
AROUND 20 TO THE UPPER 20S...COOLEST OVER THE FAR E...CLOSER TO
DEPARTING THERMAL TROF.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 331 AM EST MON MAR 2 2015
PRIMARY IMPACT IN THE LONG TERM WILL BE TUE AS MODERATE SNOW MOVES
THROUGH THE AREA.
AT 12Z TUE A NRN STREAM SYSTEM WILL BE OVER NRN MANITOBA WHILE A SRN
STREAM SYSTEM IS OVER THE CENTRAL PLAINS. LIGHT SNOW SHOULD BE
ONGOING LATE MON NIGHT INTO TUE MORNING...MAINLY OVER THE SRN/SWRN
CWA. SRN STREAM ENERGY STAYS MAINLY S OF THE CWA ON TUE AS THE NRN
STREAM SYSTEM MOVES INTO FAR NRN ONTARIO. GENERALLY MODERATE SNOW
WILL FALL ACROSS MOST OF THE REGION IN THE BROAD AREA OF
WAA/ISENTROPIC ASCENT ALONG WITH LARGER SCALE FORCING AS THE TROUGH
MOVES IN FROM THE W. SNOW RATIOS SHOULD BE BETWEEN 15-1 AND 18-1
AS TEMP PROFILES DO NOT SHOW THE DGZ BEING PARTICULARLY DEEP...BUT
DEEP ENOUGH TO KEEP RATIOS FROM BEING AS LOW AS 10-1. GENERALLY
PREFER A BLEND OF MODEL QPF FROM THE 00Z/02 GFS...12Z/01
ECMWF...00Z/02 NAM/NAM DNG...00Z/02 REGIONAL GEM AND 00Z/02 CONSALL.
THESE MODELS ARE IN GENERAL AGREEMENT ON QPF AMOUNTS...BUT THERE IS
STILL SOME DIFFERENCES...LIKELY DUE TO CHALLENGES OF SYSTEM PHASING.
PREFERRED MODEL BLEND GIVES QPF AMOUNTS OF 0.20-0.28
INCHES...RESULTING IN SNOWFALL AMOUNTS RANGING FROM AROUND 2.5
INCHES SCENTRAL TO 3-5 INCHES ELSEWHERE. LOOKING AT THE HIGHER END
OF PREFERRED GUIDANCE...QPF AMOUNTS UP TO 0.35 INCHES ARE NOT OUT OF
THE QUESTION...WHICH WOULD ALLOW FOR QPF AMOUNTS UP TO 5-6 INCHES.
THE LOW END OF PREFERRED GUIDANCE WOULD RESULT IN 2-3.5 INCHES OF
SNOW. LOOKING LIKE AN ADVISORY WILL BE NEEDED FOR TUE AS MOST OF THE
SNOW FALLS IN LESS THAN 12 HOURS DURING THE DAY AND CRITERIA IS 3-6
INCHES. WILL ALLOW THE DAY SHIFT TO TAKE ANOTHER LOOK AT THINGS
GIVEN VARIABILITY OF EXACT AMOUNTS AND PLACEMENT DUE TO COMPLEXITIES
OF SYSTEM PHASING.
WITH 850MB TEMPS AS WARM AS -9C ON TUE...SFC HIGH TEMPS WILL BE IN
THE MID TO UPPER 20S. ANOTHER COLDER PERIOD WILL FOLLOW THE PASSAGE
OF A STRONG COLD FRONT TUE AFTERNOON/EVENING AND A SECONDARY COLD
FRONT TUE NIGHT/WED MORNING. 850MB TEMPS WILL DECREASE TO A MINIMUM
OF -25C TO -30C WED INTO WED NIGHT. THIS WILL RESULT IN TEMPS
FALLING INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO BY LATE WED
MORNING...THEN INCREASING TO THE SINGLE DIGITS ABOVE ZERO DURING
PEAK HEATING WED AFTERNOON. SFC HIGH PRESSURE WILL START TO WORK
INTO THE AREA FROM THE W WED NIGHT...WHICH SHOULD ALLOW FOR VERY
COLD TEMPERATURES UNDER THE LINGERING COLD AIRMASS WITH LOWS WED
NIGHT FALLING TO AROUND -20 ALONG THE WI BORDER IN GOGEBIC AND IRON
COUNTIES. TEMPERATURE MODERATION WILL THEN OCCUR FRI THROUGH THE
WEEKEND.
WITH LAKE SUPERIOR NEARLY COMPLETELY ICE COVERED...LES
COVERAGE/INTENSITY IS SIGNIFICANTLY REDUCED...BUT SCATTERED LIGHT
LES IS EXPECTED TUE NIGHT INTO THU IN NW WIND SNOWBELTS. BLOWING
SNOW WILL BE AN ISSUE ALONG LAKE SUPERIOR AS WNW WINDS INCREASE
BEHIND THE COLD FRONTS...WITH GUSTS UP TO 40MPH POSSIBLE ALONG THE
SHORE LATE TUE INTO WED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1206 AM EST MON MAR 2 2015
WNW WINDS IN WAKE OF SFC LOW PRES TROF COULD RESULT IN SOME SCT -SHSN
AND TEMPORARY MVFR CIGS OVERNIGHT AT KIWD AND KCMX. ARRIVAL OF DRIER
AIR AND BACKING WINDS MON MORNING WILL BRING A RETURN OF VFR
CONDITIONS TO KIWD AND KCMX LATE MORNING. AT KSAW...EXPECT VFR
CONDITIONS TO PREVAIL TONIGHT THRU MON MORNING UNDER DOWNSLOPE WNW
FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 310 PM EST SUN MAR 1 2015
SEEMS THAT POTENTIAL FOR GALES IS INCREASING TUESDAY NIGHT INTO
WEDNESDAY IN WAKE OF COLD FRONT THAT MOVES THROUGH ON TUESDAY.
STRONGEST WINDS WOULD BE OVER THE EASTERN HALF OF LK SUPERIOR.
OTHERWISE...EXPECT WINDS THROUGH THE WEEK TO BE 15 TO 25 KTS.
LATEST OFFICIAL ICE CONCENTRATION ON LK SUPERIOR IS AROUND 95 PCT.
EVEN WITH STRONG WINDS AT TIMES THIS WEEK...EXPECT THE HIGHER ICE
COVERAGE TO PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...VOSS
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1210 AM EST MON MAR 2 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 422 PM EST SUN MAR 1 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF EXTENDING FROM
HUDSON BAY INTO THE NRN PLAINS. WITHIN TROF...NEXT SHORTWAVE OF
INTEREST IS NOW OVER THE DAKOTAS/MN. CLOSER TO HOME...SOME
-SHSH/FLURRIES HAVE SPREAD FROM WRN UPPER MI INTO PORTIONS OF CNTRL
UPPER MI TODAY IN VCNTY OF SFC TROF WHICH IS NOW ROUGHLY BISECTING
UPPER MI.
TONIGHT...SHORTWAVE NOW OVER THE DAKOTAS WILL SWING ACROSS THE WRN
GREAT LAKES THIS EVENING. AREA OF DEEP LAYER FORCING PER QVECTORS
SHIFTS ACROSS UPPER MI LATE THIS AFTN AND EVENING. WITH ASSOCIATED
BRIEF PERIOD OF DEEP MOISTURE...850MB TEMPS AROUND -18C...AND A
ROUGHLY 3KFT DGZ LAYER BTWN ROUGHLY 2K AND 5KFT...WOULD NORMALLY BE
CONCERNED ABOUT SEEING SEVERAL HRS OF HEALTHY LAKE ENHANCED SNOW IF
THE LAKE WASN`T MOSTLY ICE COVERED. THAT SAID...THE BRISK SW TO W
WINDS OF THE LAST COUPLE OF DAYS HAVE OPENED UP SOME NOTABLE GAPS IN
THE ICE...SO THERE WILL BE AN OPPORTUNITY FOR LOCALIZED MORE
PERSISTENT LES AND SOME SNOW ACCUMULATION. FROM TODAYS MODIS AND VIS
SATELLITE IMAGERY...A COUPLE OF IMPORTANT GAPS IN THE ICE ARE NOTED
FROM AROUND THE HURON ISLANDS DOWN PAST GRANITE ISLAND AND OVER TO N
OF MUNISING...AND ALSO IN THE AREA E OF THE APOSTLE ISLANDS WHICH
HAS CERTAINLY HAD A TENDENCY TO OPEN UP OVER THE LAST FEW WEEKS WHEN
WINDS ARE SW. WILL THUS HIT HIGHEST POPS AND 1-2 INCHES OF SNOW
DOWNWIND OF THESE OPEN WATER AREAS THIS EVENING (JUST N OF IRONWOOD
TO THE PORCUPINE MTNS AND ALSO ALGER COUNTY). STRONG NEGATIVE
DYNAMICS TAKE OVER DURING THE OVERNIGHT...SO LES INTENSITY WILL
DIMINISH RATHER QUICKLY AFTER MIDNIGHT. AWAY FROM THESE AREAS...
WNW/NW FLOW LES SHOULD BE NO MORE THAN SCT WITH ACCUMULATIONS UNDER
1 INCH. ELSEWHERE...EXPECT SOME FLURRIES IN MOST AREAS AS SHORTWAVE
PASSES. TEMPS IN THE INTERIOR W TOWARD THE WI BORDER SHOULD FALL
DOWN TOWARD ZERO WITH CLEARING SKIES OVERNIGHT. OTHERWISE...MIN
TEMPS SHOULD BE WITHIN A FEW DEGREES OF 10F.
ANY LINGERING LES TO THE E OF MARQUETTE WILL END BY MON AFTN UNDER
WAA/BACKING WINDS WITH PASSAGE OF SFC HIGH PRES RIDGE (BY MID AFTN
850MB TEMPS ARE FCST TO BE AROUND -12C). WHILE THERE MAY BE SOME
STRATOCU DEVELOPMENT EVEN WHERE SKIES ARE CLEAR TO START THE
DAY...EXPECT ALL AREAS TO BECOME SUNNY DURING THE DAY WITH DRY AIR
MASS AND DEPARTURE OF 850MB THERMAL TROF. HIGH TEMPS WILL RANGE FROM
AROUND 20 TO THE UPPER 20S...COOLEST OVER THE FAR E...CLOSER TO
DEPARTING THERMAL TROF.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 PM EST SUN MAR 1 2015
...WIDESPREAD SNOW TUESDAY MAY EVENTUALLY NEED A HEADLINE...
PRIMARY HIGHER IMPACT WEATHER THROUGH THE NEXT WEEK IS LIMITED TO
WIDESPREAD SNOW EXPECTED TO AFFECT THE AREA ON TUESDAY AND TUESDAY
EVENING. OTHERWISE...WARM UP EARLY IN THE WEEK WILL BE REPLACED BY A
COOL DOWN WEDNESDAY INTO THURSDAY IN WAKE OF THE TUESDAY SYSTEM. MAY
BE SOME LAKE EFFECT WEDNESDAY AND WEDNESDAY NIGHT BUT CHANCES WILL
BE HELD DOWN AS LAKE SUPERIOR REMAINS MOSTLY ICE COVERED. TEMPS
REBOUND AGAIN BY NEXT FRIDAY AND COULD STAY AT SIMILAR LEVELS INTO
NEXT WEEKEND.
HIGH PRESSURE EXITS EAST ON MONDAY EVENING WITH CLOUDS INCREASING
THROUGH THE NIGHT AHEAD OF A TWO-PIECED LOW PRESSURE SYSTEM HEADING
TOWARD REGION. NORTHERN STREAM WAVE AND ITS ASSOCIATED LOW SLIDES FM
NORTHERN MANITOBA TO NORTHERN ONTARIO BY DAYBREAK ON TUESDAY.
MEANWHILE THE SOUTHERN STREAM WAVE WILL PUSH OVER THE CENTRAL PLAINS
AS THE SFC LOW ARRIVES ALONG THE NEB/IOWA BORDER. MOISTURE ADVECTION
AHEAD OF THE LOW-MID LEVEL TROUGH MAXIMIZES OVERNIGHT BTWN H85 AND
H5. LIFT IS PRETTY STRONG WITHIN THE MOIST ADVECTION...SO SHOULD SEE
LGT SNOW BEGIN TO DEVELOP AFTER MIDNIGHT TOWARD WI BORDER WITH
LOWEST 100MB GRADUALLY SATURATING. HINTS ARE THERE THAT THE INITIAL
SNOW COULD BE DRIVEN BY FGEN...BUT WHERE MAX RIBBON OF HEAVIER SNOW
SETS UP IS NOT CERTAIN. 12Z NAM SHOWS IT MORE OVER WESTERN CWA...BUT
THIS IS AT ODDS WITH NAM DOMINATED SREF OUTPUT AND SEEMS TOO FAR
NORTH AS IT IS ALSO FARTHER NORTH WITH SOUTHERN STREAM SFC LOW ON
INTO TUESDAY. WILL KEEP WITH IDEA OF HEAVIER QPF/SNOW ON TUESDAY ON
EDGE OF GREATER H85-H7 MOISTURE TRANSPORT WHICH MAINLY IS MAXIMIZED
JUST TO THE SOUTH AND SOUTHEAST OF UPR MICHIGAN OUT AHEAD OF
SOUTHERN STREAM SFC LOW CROSSING LOWER MICHIGAN. H7 MIXING RATIOS
GFS/ECMWF STAY BLO 3G/KG THROUGHOUT TUESDAY. MIXING RATIOS INTO THE
SYSTEM AND BLEND OF QPF FM GFS/ECMWF ALONG WITH SLR/S CENTERED ON
15:1...SUGGEST ADVY LEVEL SNOWFALL SCNTRL CWA INTO THE EASTERN CWA.
WILL CONTINUE TO MENTION IN HWO/EHWO GRAPHICS.
PHASING BTWN THE NORTHERN STREAM WAVE AND SOUTHERN STREAM WAVES
NEVEN REALLY TAKES OFF SO THIS SYSTEM SHOULD STAY PROGRESSIVE ON
TUESDAY NIGHT AS MAIN CORE OF UPPER JET ENERGY STAYS OUT AHEAD OF
THE TROUGH. CHANCE POPS LINGER EARLY TUESDAY EVENING IN THE
EAST...BUT OTHERWISE POPS WITH THE SYSTEM WILL BE OUT OF THE AREA.
INITIALLY LAKE EFFECT IN WAKE OF THE SYNOPTIC SNOW ON TUESDAY
EVENING PROBABLY STAYS ON THE LIGHT SIDE DUE TO MARGINALLY COLD AIR
/H85 TEMPS WARMER THAN -15C/ AND MAINLY ICE COVERED LAKE SUPERIOR.
GFS SOUNDINGS SHOW INCREASE OF MOISTURE H8-H7 LATE TUESDAY NIGHT
INTO WEDNESDAY WHILE COLD AIR ADVECTION WITH H85 TEMPS FALLING BLO
-20C OVER LK SUPERIOR RESULTS IN INVERSIONS RISING UP TO A MAX OF
8KFT WEDNESDAY MORNING OVER EASTERN LK SUPERIOR. DESPITE THE HIGH
ICE COVERAGE...SCT POPS FOR LAKE EFFECT SNOW SHOWERS AND ALSO
FARTHER DOWNSTREAM OVER LAND AREAS WITH SOME HELP FM DAYTIME HEATING
AS THE HYBRID LAKE EFFECT SEASON IS UNDERWAY DUE TO HIGHER SUN
ANGLE. WITH NW WINDS UP TO 30 MPH ALONG THE LK SUPERIOR
SHORELINES...PROBABLY WILL HAVE BLSN/POOR VSBY IN THE SNOW BELTS
NEAR LK SUPERIOR EAST OF MQT. EVEN MINUS BLSN...LES WILL BE GOOD AT
REDUCING VSBY AS THE SNOWFLAKES WILL BE BECOMING SMALLER. H85 TEMPS
CONTINUE TO FALL BLO -25C BY LATE IN THE DAY ON WEDNESDAY...SO TEMPS
WILL BE STEADY OR SLOWLY FALL THROUGH THE DAY.
ARRIVAL OF HIGH PRESSURE RIDGE AND WINDS BACKING W-WSW BY THURSDAY
MORNING WILL DIMINISH ANY SNOW SHOWERS AS WINDS BECOME MORE
OFFSHORE. TEMPS OVER MUCH OF THE INTERIOR ON WEDNESDAY NIGHT COULD
TANK WELL UNDER 10 BLO ZERO. MAY SEE MARGINALLY LOW WIND CHILLS ON
THURSDAY MORNING...BUT FARTHER INLAND WHERE TEMPS WILL BE COLDEST
EXPECT THE WINDS TO BE NEARLY CALM. STILL COLD ON THURSDAY AS CORE
OF COLDER TEMPS ALOFT SLOWLY HEADS ACROSS EASTERN CANADA.
WARM FRONT MOVES TOWARD UPPER LAKES THURSDAY NIGHT INTO FRIDAY
MORNING. WARMING FIRST OCCURS ALOFT THEN MAKES ITS WAY TO SFC BY
FRIDAY AFTN. GFS SOUNDINGS SHOW MID LEVEL MOISTURE QUICKLY SWEEPS
ACROSS LEAVING SCT-BKN LOW CLOUDS LATER ON FRIDAY. MOISTURE AND LIFT
DOES NOT SYNC UP...SO NOT EXPECING MUCH IN WAY OF LGT SNOW. BETTER
LINKING OF LOW AND MID LEVEL MOISTURE IS OVER NORTHERN LK SUPERIOR
AND NORTHERN ONTARIO. DECENT AGREEMENT IN THIS IDEA FM GFS AND
ECMWF. COLD AIR NOT AS EMPHATIC FOR NEXT WEEKEND WITH GFS AND ECMWF
SHOWING H85 TEMPS MAINLY WARMER THAN -12C. GIVEN THE RUN-TO-RUN
DIFFERENCES IN MODELS AND DIFFERENCES IN MODEL SOLUTIONS...WILL JUST
RUN WITH CONSENSUS FRIDAY THROUGH SUNDAY. RESULT IS DAYTIME TEMPS IN
THE 20S TO NEAR 30 DEGREES AND ONLY SMALL CHANCES OF LGT SNOW MAINLY
OVER THE NORTH AND EAST CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1206 AM EST MON MAR 2 2015
WNW WINDS IN WAKE OF SFC LOW PRES TROF COULD RESULT IN SOME SCT -SHSN
AND TEMPORARY MVFR CIGS OVERNIGHT AT KIWD AND KCMX. ARRIVAL OF DRIER
AIR AND BACKING WINDS MON MORNING WILL BRING A RETURN OF VFR
CONDITIONS TO KIWD AND KCMX LATE MORNING. AT KSAW...EXPECT VFR
CONDITIONS TO PREVAIL TONIGHT THRU MON MORNING UNDER DOWNSLOPE WNW
FLOW. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 310 PM EST SUN MAR 1 2015
SEEMS THAT POTENTIAL FOR GALES IS INCREASING TUESDAY NIGHT INTO
WEDNESDAY IN WAKE OF COLD FRONT THAT MOVES THROUGH ON TUESDAY.
STRONGEST WINDS WOULD BE OVER THE EASTERN HALF OF LK SUPERIOR.
OTHERWISE...EXPECT WINDS THROUGH THE WEEK TO BE 15 TO 25 KTS.
LATEST OFFICIAL ICE CONCENTRATION ON LK SUPERIOR IS AROUND 95 PCT.
EVEN WITH STRONG WINDS AT TIMES THIS WEEK...EXPECT THE HIGHER ICE
COVERAGE TO PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...VOSS
MARINE...JLA
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
330 AM EST MON MAR 2 2015
.SYNOPSIS...
A COLD FRONT WITH LIMITED MOISTURE WILL MOVE THROUGH THE AREA
TODAY. HIGH PRESSURE BEHIND THE FRONT WILL BUILD INTO THE AREA
FROM THE NORTH TONIGHT INTO TUESDAY. A WARM FRONT WILL MOVE NORTH
THROUGH THE AREA TUESDAY INTO TUESDAY NIGHT. A STRONG COLD FRONT
WILL MOVE THROUGH THE AREA THURSDAY. HIGH PRESSURE WILL BUILD INTO
THE REGION FROM THE NORTH FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /TODAY/...
AS OF 330 AM MON...CURRENTLY...MOST AREAS STILL ABOVE 1/4 MILE
VISIBILITY DUE TO LIGHT SFC WINDS KEEPING SFC A BIT MIXED...THOUGH
SHOULD WINDS DECOUPLE MAY HAVE SOME AREAS OF DENSE FOG DEVELOPING
TOWARDS SUNRISE. DUE TO LOW CONFIDENCE ON THIS HAPPENING...WILL
REFRAIN FROM ISSUING A DFA ATTM.
FOR TODAY...REINFORCING COLD FRONT WILL PUSH THROUGH E NC LATE
THIS MORNING/EARLY AFTERNOON. NOT MUCH FORCING OR MOISTURE
ASSOCIATED WITH THE FRONT THOUGH NOT ENOUGH CONFIDENCE TO REMOVE
THE INHERITED 20 POP FROM GRIDS. ANY ISOLATED SHOWERS WILL MOVE
OFFSHORE WITH THE FRONT AFTER AROUND NOON TODAY...FOLLOWED BY
PARTIAL CLEARING FROM NW TO SE AS COLUMN DRIES. BASED ON LOW LEVEL
THICKNESS VALS AND MO CLOUDY SKIES FOR A BETTER PART OF THE DAY...
SHOULD SEE HIGHS IN THE 50S (LOW 50S NE TO UPPER 50S SW).
&&
.SHORT TERM /TONIGHT/...
AS OF 330 AM MON...SKIES SHOULD BE MOSTLY CLEAR TO START THE
NIGHT AS TRANSITORY HIGH SCOOTS BY TO THE NORTH. MUCH DRIER AIR
MASS WILL FILTER INTO THE REGION WITH LIGHT WINDS...AND OVERNIGHT
LOWS WILL FALL WELL INTO THE 30S. TEMPS MAY BOTTOM OUT AROUND
MIDNIGHT BEFORE LEVELLING OFF AND THEN RISING TOWARDS DAYBREAK AS
INC ISENTROPIC LIFT OCCURS DUE TO WARMING ALOFT AND INC MID/HIGH
CLOUD COVER MOVES IN FROM THE SW.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...AN ACTIVE WEATHER PATTERN IS EXPECTED THIS
WEEK AS TRANSIENT SYSTEMS IN A SPLIT FLOW REGIME AFFECT THE
FORECAST AREA. LARGE SWINGS IN TEMPERATURE WILL BRING SPRINGLIKE
WARMTH DURING MIDWEEK FOLLOWED BY A CHANCE OF WINTRY PRECIP AND
COLD ON THURSDAY. THE UNSEASONABLY COLD TEMPERATURES WILL PREVAIL
THROUGH LATE IN THE WEEK.
HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTH INTO EARLY TUESDAY.
A WARM FRONT IS THEN FORECAST TO SLOWLY RETREAT TO THE NORTH
TUESDAY AFTERNOON AND EVENING. PATCHY TO PERHAPS WIDEPSREAD LIGHT
RAIN IS EXPECTED AS THE BOUNDARY TRAVERSES THE AREA INTO TUESDAY
EVENING. LATEST GUIDANCE SUGGESTS THAT PRECIPITATION HOLDS OFF
UNTIL SURFACE WARNS ABOVE FREEZING TUESDAY SO NOT EXPECTING ANY P
TYPE ISSUES ALTHOUGH THERE IS LIKELY TO BE A LARGE TEMPERATURE
GRADIENT ACROSS THE AREA AS THE WEDGE INLAND RETARDS THE FRONTAL
PROGRESS UNTIL EVENING. THUS THE IMMEDIATE COAST COULD MAKE INTO
THE 60S LATE WHILE DEEPER INLAND LOCATIONS REMAIN IN THE 40S. THE
WARM FRONT IS FORECAST TO FINALLY MOVE NORTH OF THE AREA TUESDAY
NIGHT AS THE WEDGE ERODES WITH TEMPERATURES LIKELY WARMING INTO
THE 60S THROUGHOUT THE AREA. THUS WILL NEED TO FORECAST A NON
DIURNAL TEMPERATURE CYCLE WITH TUESDAYS "HIGHS" LIKELY TO BE
TUESDAY NIGHTS "LOWS" AS THE WARM SECTOR SURGES NORTH ACROSS
EASTERN NC.
MODELS ARE IN GOOD AGREEMENT FOR UNSEASONABLY MILD TEMPERATURES (FOR
A CHANGE) ON WEDNESDAY WITH HIGHS INTO THE 70S AWAY FROM ANY
COOLING ONSHORE BREEZES. COULD SEE SEA FOG/STRATUS ALONG THE SOUTH
FACING COASTLINES WHICH COULD LIMIT TEMPERATURES. THE MODELS
CONTINUE TO TREND LATER WITH RAIN CHANCES TO LATE WEDNESDAY INTO
WED NIGHT AS AN ANA FRONT TYPE PRECIP REGIME SETS UP BEHIND THE
INCOMING SFC BNDRY.
THERE ARE LARGE DIFFERENCES IN THE MODELS REGARDING THE SPEED OF
A STRONG COLD FRONT WHICH WILL MOVE THROUGH THE AREA THURSDAY. THE
GFS IS CONSIDERED TOO FAST WITH THE FRONT MAKING IT TO THE CRYSTAL
COAST BY 12Z THURSDAY WHILE THE NAM IS CONSIDERED TOO SLOW WITH
THE FRONT STILL WEST OF THE COASTAL PLAIN AT THIS TIME. THE ECMWF
WAS THE COMPROMISE CHOICE WITH THE FRONT MOVING INTO THE NW ZONES
LATE WEDNESDAY NIGHT AND THEN THROUGH THE REMAINDER OF THE AREA
LATE THURSDAY MORNING. PRECIP CHANCES SHOULD INCREASE AS THE
FRONT MOVES THRU AND BRINGS THE NEXT ROUND OF ARCTIC AIR TO THE
REGION. THERMAL PROFILES FAVOR A CHANGEOVER TO FROZEN
PRECIPITATION FROM NORTH TO SOUTH DURING THURSDAY BEFORE ENDING
LATER THU AFTERNOON OR EVENING AND WILL CONTINUE A LOW CONFIDENCE
CHANCE OF SNOW AND SLEET. TOO EARLY TO GET INTO MUCH DETAIL ABOUT
POSSIBLE ACCUMULATIONS AS YET BUT PRECIP LOOKS TO BE MOVING THRU
QUICKLY WHICH WOULD LIMIT AMOUNTS.
PRECIP ENDS LATE THU/THU EVENING FROM NW TO SE, WITH STRONG HIGH
PRESSURE BUILDING EAST OVER THE REGION FROM THE TENNESSEE VALLEY
AREA INTO SATURDAY. THICKNESSES FALL QUICKLY BEHIND THE FRONT FRIDAY
WITH HIGHS ONLY EXPECTED IN THE 40S FRIDAY AND UPPER 40S TO LOWER
50S SATURDAY/SUNDAY. LOWS THU AND FRIDAY WILL DROP WELL INTO THE 20S.
THE FORECAST FOR LATE IN THE WEEKEND IS VERY UNCERTAIN WITH A
LARGE SPREAD IN THE GUIDANCE (GFS DRY/ECMWF WETTER). WILL
CONTINUE TO INDICATE DRY WEATHER SUNDAY UNTIL PERIOD COMES INTO
BETTER FOCUS.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1 AM SUN...WIDESPREAD LIFR CONDITIONS CURRENTLY WITH
CEILINGS 2-500 FT. IN ADDITION TO THE LOW CIGS AREAS OF FOG 1/2 TO
1 MILE ARE OCCURRING. COULD SEE VSBYS DROP EVEN FURTHER IF WINDS
DECOUPLE...THOUGH RIGHT NOW EXPECT LIGHT SFC FLOW TO KEEP DENSE
FOG AT BAY FOR THE MOST PART. CONDITIONS LOOK TO SLOWLY IMPROVE
MONDAY MORNING WITH MVFR THEN FINALLY VFR BY AROUND NOON. COLD
FRONT WILL MOVE THROUGH THE TERMINALS LATE MORNING/EARLY AFTERNOON
WITH WINDS VEERING BECOMING NORTH 10KT POSSIBLY GUSTING A LITTLE
HIGHER.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...DRIER AIR SPREADS INTO THE AREA WITH VFR
CONDITIONS EXPECTED INTO EARLY TUESDAY THEN A WARM FRONT WILL
RETREAT SLOWLY TO THE NORTH TUESDAY AFTERNOON AND EVENING WITH
POSSIBLY SOME LOWER FLIGHT CATEGORIES AS MOISTURE INCREASES OVER
THE AREA WITH PATCHY TO WIDESPREAD LIGHT RAIN EXPECTED. A COLD
FRONT WILL APPROACH FROM THE WEST WEDNESDAY NIGHT AS SURFACE FLOW
SHIFTS SOUTHWEST AND MAY BECOME GUSTY WEDNESDAY AFTERNOON WITH
ONLY WIDELY SCATTERED RAIN SHOWERS FORECAST. A STRONG COLD FRONT
WILL CROSS THE REGION LATE WED NIGHT AND MOVE OFFSHORE THU. GOOD
CVRG OF RAIN WED NIGHT AND EARLY THU WITH PRECIP DIMINISHING
LATE...POSS MIXED WITH SOME SNOW OR SLEET INLAND. SUB VFR
CONDITIONS ARE A GOOD BET LATER WED NIGHT AND MUCH OF THU. STRONG
HIGH PRESSURE BUILDS IN FOR A RETURN TO PREDOMINANT VFR CONDITIONS
LATE IN THE WEEK.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 330 AM MON. CURRENT OBS SHOWING SEAS 3 TO 5 FT WITH A WSW
WIND 10 TO 15 KT. FOR TODAY...THE WSW WINDS WILL BECOME NORTH THIS
AFTERNOON AND INC BEHIND A COLD FRONT. WE EXPECT A NORTHERLY SURGE
THIS AFTERNOON...AND RIGHT NOW ALL BUT ALBEMARLE SOUND AND THE
RIVERS SHOULD SEE SCA DEVELOPING. HRRR AND NSSL WRF INDICATE
ENOUGH OF A SURGE TO PRODUCE SCA WIND GUSTS EASTERN PAMLICO SOUND
BEGINNING AROUND 18Z. THE GUSTY WINDS WILL SLOWLY VEER NE AND
DIMINISH TONIGHT...WITH VARIOUS SCA HEADLINES ENDING AROUND 9Z AS
SEAS TAKE A BIT LONGER TO RESPOND TO DIMINISHING WINDS.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...STRONG WINDS AND ROUGH SEAS WILL PREVAIL
OVER THE MARINE AREA DURING THE PERIOD AS A SERIES OF WEATHER
SYSTEMS TRAVERSE THE WATERS. WINDS WILL BRIEFLY DIMINISH TUE MORN
THEN BEGIN TO RAMP UP FROM THE S LATE TUE AS A WARM FRONT LIFTS N
THRU THE AREA. SEAS WILL DIMINISH EARLY TUE THEN BUILD BACK UP TO
4 TO 6 FT BY TUE EVENING HIGHEST FAR OUTER CNTRL WTRS. GUSTY SSW
WINDS WILL DEVELOP TUE NIGHT AND CONT WED AHEAD OF APPROACHING
COLD FRONT...SEAS WILL BUILD TO 5 TO 9 FEET OUTER WTRS WED. THE
COLD FRONT WILL CROSS THE EASTERN NC COASTAL WATERS LATE WEDNESDAY
NIGHT/EARLY THU WITH STRONG HIGH PRESSURE BUILDING IN FROM THE
WEST THURSDAY, LEADING TO GUSTY N WINDS THU WITH SEAS OF 5 TO 9
FEET. WINDS/SEAS WILL SLOWLY DECREASE AS COLD AIR ADVECTION WANES
LATE FRIDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR AMZ130-131-
135>137-150-152-154-156-158.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 1 AM EST
TUESDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM EST
TUESDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 4 AM EST
TUESDAY FOR AMZ150.
&&
$$
SYNOPSIS...JME/TL
NEAR TERM...TL
SHORT TERM...TL
LONG TERM...JME/BTC
AVIATION...JME/BTC/TL
MARINE...JME/BTC/TL
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1123 PM CST SUN MAR 1 2015
.UPDATE...
ADJUSTED PRECIP/WX AND TEMPS... ONCE AGAIN...
&&
.DISCUSSION...
HAD TO FIX TEMPS ACROSS NWRN OK... CLOUDS BUILDING IN ACROSS NWRN
OK HAVE ALLOWED FOR MORE INSOLATION THIS EVENING... KEEPING TEMPS
IN THE LOWER 30S/UPPER 20S THROUGH 11PM. ADJUSTED FOR THIS TREND
THROUGH THE MORNING HOURS... AND MUCH LIKE THE PREVIOUS UPDATE...
OVERNIGHT LOWS WILL BE A FEW DEGREES WARMER THAN PREVIOUSLY
THOUGHT.
WATCHING RADAR TRENDS... THE HRRR HAS COME IN MORE AGGRESSIVE WITH
PRECIP ACROSS NRN TX... NOT SURE HOW MUCH STOCK TO PUT IN THIS AT
THE MOMENT SINCE ITS TRACK RECORD WITH WEAK FORCING IS NOT ALL
THAT GREAT. HOWEVER... GETTING BETTER ECHOS ON KFWS IN NORTH TX...
WITH DRIZZLE REPORTED AT A FEW SITES NORTH OF THE METROPLEX.
DECIDED TO BUMP UP POPS A SKOSH ACROSS TEXOMA... MAY HAVE BEEN A
LITTLE TOO BULISH EARLIER THIS EVENING. KEPT PRIMARY PRECIP TYPE
DRIZZLE OVERNIGHT.
JTK
&&
.PREV DISCUSSION... /ISSUED 1100 PM CST SUN MAR 1 2015/
DISCUSSION...
AVIATION DISCUSSION FOR THE 06Z TAFS IS BELOW.
AVIATION...
OVERALL...WILL NOT MAKE ANY SIGNIFICANT CHANGES TO THE PREVIOUS
TAFS.
GENERALLY BELIEVE VFR/MVFR CONDITIONS WILL PREVAIL WITH THE
HIGHEST CHANCES FOR VFR CONDITIONS OVER NORTHERN OKLAHOMA.
CONDITIONS WILL SLOWLY WORSEN TO MVFR AT ALL LOCATIONS BY 01Z...
AND PERHAPS IFR SOUTH OF KCSM-KSWO AFTER 01Z.
MBS
PREV DISCUSSION... /ISSUED 913 PM CST SUN MAR 1 2015/
UPDATE...
ADJUSTED PRECIP/WX AND TEMPS...
DISCUSSION...
JUST A QUICK UPDATE TONIGHT... PULLED BACK CHANCES FOR RA/DZ EARLY
THIS EVENING AND FZRA/FZDZ OVERNIGHT ACROSS SRN OK/TEXOMA AND WRN
N TX. SHORT RANGE GUIDANCE FROM THE RAP/HRRR HAVE TRIMMED BACK
CHANCES FOR LIGHT PRECIP... HOLDING THEM S/SE OF THE RED RIVER.
FROM EARLY RADAR TRENDS... THIS SOLUTION SEEMS PROBABLE. AS FOR
PRECIP TYPE... HAD TO REIN IN TEMPS THIS EVENING AS EARLIER
FORECAST WAS DROPPING THEM TOO FAST. WHERE PRECIP CHANCES
EXIST... TEMPS WILL HOVER AT OR JUST ABOVE FREEZING. THEREFORE...
CONTINUED WITH LIGHT RA/DZ CHANCES THROUGH MONDAY MORNING. KEPT
FOG CHANCES GOING OVERNIGHT... BUT DROPPED TO PATCHY AS N/NE WINDS
ACROSS NRN OK DON`T ALWAYS BODE WELL FOR WIDESPREAD FOG
DEVELOPMENT. HOWEVER... WITH THAT SAID... WITH LIGHT WINDS AND
PLENTY OF MOISTURE ON THE GROUND... PATCHES OF LIGHT FOG ARE
LIKELY OVERNIGHT.
JTK
PREV DISCUSSION... /ISSUED 238 PM CST SUN MAR 1 2015/
DISCUSSION...
WITH THIS ISSUANCE...WE WILL NOT ISSUE ANY NEW WINTER WEATHER
ADVISORIES. HOWEVER...A SPECIAL WEATHER STATEMENT WILL BE ISSUED
TO HIGHLIGHT AREAS THAT COULD SEE VERY LIGHT FREEZING PRECIP. NOT
OUT OF THE QUESTION ONE MAY BE NEEDED LATE TONIGHT AND EARLY
MONDAY ACROSS PORTIONS OF WESTERN NORTH TEXAS AND SOUTHERN
OKLAHOMA WHERE FREEZING DRIZZLE OR VERY LIGHT FREEZING RAIN
SHOWERS MAY DEVELOP. THERE ARE ALREADY TRAVEL ISSUES ACROSS THE
REGION...AND THIS WILL BE COMPOUNDED LATE TONIGHT AS SLUSHY/WET
UNTREATED ROADWAYS AND WALKWAYS REFREEZE. ADDITIONAL IMPACTS FROM
ANY LIGHT PRECIP IS CURRENTLY EXPECTED TO BE SHORT IN DURATION AND
NOT EXPECTED TO ADD MUCH TO REFREEZING ISSUE. ALL SHORT TERM
GUIDANCE NOT VERY AGGRESSIVE WITH ANY DENSE FOG/FREEZING FOG
ISSUES BUT WE WILL GO AHEAD AND MENTION FOG IN THE FORECAST.
TURN OVER TO NON-FREEZING/FROZEN PRECIP LATE TOMORROW MORNING FOR
A WHILE...AT LEAST UNTIL NEXT SURGE OF ARCTIC AIR ARRIVES LATE
TUESDAY. TRENDS OF MODELS STILL SHOW POSSIBILITY OF MAINLY LIGHT
RAIN TRANSITIONING TO FREEZING RAIN AND SLEET BEFORE ENDING AS
SNOW ON WEDNESDAY. NO SIGNIFICANT AMOUNTS EXPECTED. PRIOR TO THIS
TRANSITION THERE WILL BE A CHANCE FOR A FEW STORMS MAINLY OVER FAR
SOUTHEAST PORTIONS OF OKLAHOMA. NO SEVERE WEATHER CURRENTLY
EXPECTED.
THEREAFTER...MODERATION OF TEMPERATURES AND DRY WEATHER EXPECTED
INTO NEXT WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 33 26 39 37 / 30 10 10 30
HOBART OK 34 25 36 35 / 20 10 10 20
WICHITA FALLS TX 36 29 39 37 / 30 20 10 40
GAGE OK 33 22 38 37 / 30 10 10 10
PONCA CITY OK 32 22 40 37 / 20 10 10 30
DURANT OK 37 32 42 40 / 40 30 30 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
04/99
AREA FORECAST DISCUSSION
NWS MEDFORD OR
820 PM PST SUN MAR 1 2015
.DISCUSSION...ALREADY MADE A FEW UPDATES THIS EVENING TO RAISE
POPS ALONG THE COAST OVERNIGHT. A SYSTEM IS DROPPING SOUTH ALONG
THE OREGON COAST THIS EVENING, AND WHILE THE COLDEST CLOUD TOPS
ARE MOVING THROUGH RIGHT NOW, THE DEEPER MOISTURE IS EXPECTED
OVERNIGHT. IT HAS NOT YET RAINED AT ANY OF THE UPSTREAM OBS SITES,
BUT RADAR SHOWS RAIN APPROACHING THE NORTH OREGON COAST, AND THIS
WILL SPREAD SOUTH THROUGH THE NIGHT. ALL THE 02/00Z GUIDANCE
SHOWS AT LEAST A FEW HUNDREDTHS OF RAIN ALONG MUCH OF THE COAST BY
MONDAY MORNING WITH THE RAP BEING THE MOST BULLISH IN SHOWING UP
TO 0.10 INCH OVER THE COOS COAST. I DIDN`T GO THAT HIGH WITH
AMOUNTS, BUT I DID RAISE POPS TO CATEGORICAL FOR THE IMMEDIATE
COAST TONIGHT AND BUMPED UP QPF AS WELL. RAIN IS STILL NOT
EXPECTED TO MAKE MUCH PROGRESS INLAND, AND THE REST OF THE
FORECAST FOR TONIGHT REMAINS UNCHANGED. -WRIGHT
&&
.AVIATION...FOR THE 02/00Z TAF CYCLE...VFR CONDITIONS WITH MOSTLY
CLEAR SKIES WILL PREVAIL THROUGH THIS EVENING FOR MOST OF THE
FORECAST AREA. TONIGHT INTO MONDAY MORNING, A WEAK LOW WILL MOVE
SOUTH WITH INCREASING CLOUDS FOR THE AREA FROM NORTH TO SOUTH. SKIES
WILL MAINLY REMAIN VFR BUT ALONG THE COAST AND INTO THE UMPQUA BASIN
EXPECT AREAS OF MVFR CIGS TO DEVELOP BETWEEN 03-10Z AND CONTINUE
INTO MONDAY MORNING WITH A CHANCE OF LIGHT RAIN MAINLY AT THE COAST.
AREAS OF MOUNTAIN OBSCURATION WILL ALSO DEVELOP MONDAY MORNING,
MAINLY FROM THE CASCADES WEST. SK
&&
.MARINE...UPDATED 2 PM PST, SUNDAY, 1 MAR, 2015...HIGH CONFIDENCE
EXISTS THAT AREAS OF MODERATE NORTHERLY WINDS WILL PERSIST THROUGH
WEDNESDAY AND WILL BE STRONGEST DURING THE AFTERNOONS AND EVENINGS
AND IN THE OUTER WATERS AND SOUTH OF CAPE BLANCO. A THERMAL TROUGH
ALONG THE COAST AND HIGH PRESSURE OFFSHORE THIS EVENING WILL BE
FOLLOWED BY A LOW WITH LIGHT RAIN LATE TONIGHT INTO MONDAY MORNING.
THE PATTERN OF A THERMAL TROUGH AT THE COAST AND HIGH PRESSURE
OFFSHORE WILL DEVELOP AGAIN TUESDAY THEN WINDS WEAKEN LATE IN THE
WEEK AS THE HIGH BUILDS EASTWARD. SK
&&
.PREV DISCUSSION... /ISSUED 102 PM PST SUN MAR 1 2015/
DISCUSSION...01/12Z NAM/GFS IN.
MOSTLY CLEAR SKIES PREVAIL ACROSS THE MEDFORD CWA THIS
AFTERNOON...ALTHOUGH SOME CUMULUS IS STARTING TO DEVELOP OVER THE
RIDGES.
IT IS DIFFICULT TO DETERMINE A WAVE NUMBER AROUND THE HEMISPHERE
TODAY BUT IT DOESN`T APPEAR TO BE A FACTOR WITH AN OMEGA BLOCK IN
PLACE OVER THE EASTERN PACIFIC. THE COLDEST AIR REMAINS OVER
NORTHEAST AND FAR NORTHERN CANADA.
A STRONG RIDGE REMAINS IN PLACE ALONG 135W AND IT ISN`T GOING
ANYWHERE ANYTIME SOON. THE ANCHOR LOWS FOR THE BLOCK ARE CURRENTLY
OVER CALIFORNIA AND OUT NEAR 40N 160W. CURRENTLY THERE IS DRY
NORTHEAST FLOW ALOFT OVER THE AREA. ALL OF THIS SUPPORTS THE DRY
OFFSHORE LOW LEVEL FLOW PATTERN.
HOWEVER...A STRONG SHORT WAVE WILL MOVE DOWN THE FRONTSIDE OF THE
RIDGE TONIGHT INTO MONDAY...AND THIS WAVE DOES SPEND SOME TIME
OVER THE WATER...SO IT MAY BRING SOME PRECIPITATION TO THE AREA
ALONG THE COAST AND OVER THE COASTAL WATERS TONIGHT INTO MONDAY.
AFTER THAT...OFFSHORE LOW LEVEL FLOW AND DRY WEATHER WILL RETURN
TO THE AREA MONDAY NIGHT. THE RIDGE WILL GRADUALLY WEAKEN IN
PLACE THROUGH THURSDAY...SO THE OFFSHORE FLOW WILL WEAKEN AS WELL.
EVENTUALLY SOME HIGH LEVEL MOISTURE WILL MAKE IT OVER THE RIDGE
AND OVER THE CWA AROUND THE MIDDLE OF THE WEEK...BUT NO ADDITIONAL
PRECIPITATION IS EXPECTED.
LONG TERM DISCUSSION...THURSDAY THROUGH SUNDAY. MODELS SHOW GOOD
AGREEMENT THAT THE UPPER LEVEL HIGH PRESSURE RIDGE WILL REMAIN
OVER THE REGION BRINGING WARMING TEMPERATURES AND DRY WEATHER.
SOME AREAS OF LATE NIGHT AND EARLY MORNING VALLEY FOG ARE POSSIBLE
FOR WEST SIDE VALLEYS LATE IN THE WEEK AND PARTLY CLOUDY SKIES ARE
ALSO POSSIBLE WITH A WEAK FRONT MOVING OVER THE RIDGE WELL TO THE
NORTH THURSDAY INTO FRIDAY. OTHERWISE EXPECT MAINLY SUNNY SKIES
OVER THE AREA.
GFS, GFS ENSEMBLES AND ECMWF ARE TRENDING SLOWER WITH THE UPSTREAM
TROUGH AFFECTING THE PACNW AND DO NOT SHOW THE RIDGE SHIFTING EAST
UNTIL AROUND TUESDAY OF NEXT WEEK. /CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST MONDAY FOR PZZ356.
SMALL CRAFT ADVISORY FOR WINDS FROM 7 PM MONDAY TO 1 AM PST
TUESDAY FOR PZZ356.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST MONDAY
FOR PZZ350-356.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 PM PST MONDAY FOR PZZ370.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST TUESDAY
FOR PZZ370-376.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 1 AM PST TUESDAY FOR
PZZ376.
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1132 PM CST SUN MAR 1 2015
.UPDATE...
UPDATED FOR 06Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 801 PM CST SUN MAR 1 2015/
UPDATE...
THE CURRENT FORECAST LOOKS VERY GOOD THIS EVENING. THE ONLY
UPDATE MADE WAS TO ADD FREEZING DRIZZLE TO NORTHERN ZONES AS IT
LOOKS LIKE THE BULK OF THE PRECIP WILL SHIFT SOUTH AS THE LOW
LEVEL JET CONTINUES TO VEER. OTHERWISE...INTERMITTENT LIGHT
RAINFALL WILL CONTINUE ACROSS MUCH OF THE MIDSOUTH OVERNIGHT AS
WEAK UPGLIDE PERSISTS. WILL CONTINUE TO WATCH HOW THE 0 DEGREE
ISOTHERM EVOLVES THIS EVENING BUT BELIEVE THE CURRENT FORECAST HAS
THE FREEZING PRECIP HANDLED VERY WELL.
TVT
PREV DISCUSSION... /ISSUED 545 PM CST SUN MAR 1 2015/
UPDATE...
UPDATED FOR 00Z AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 329 PM CST SUN MAR 1 2015/
DISCUSSION...SURFACE ANALYSIS THIS AFTERNOON CONTINUES TO
INDICATE AN INVERTED SURFACE TROUGH LOCATED ACROSS THE MID SOUTH
THIS AFTERNOON. TEMPERATURES THROUGHOUT THE DAY HAVE REMAINED
NEARLY STEADY WITH UPPER 30S TO LOWER 40S PREVALENT ALONG AND WEST
OF THE MISSISSIPPI RIVER AND LOWER 40S TO LOWER/MIDDLE
50S...ESPECIALLY ACROSS NORTHEAST MISSISSIPPI. POTENTIAL FOR LIGHT
FREEZING DRIZZLE ACROSS THE NORTHERN THIRD OF THE MID SOUTH LATE
TONIGHT AND YET ANOTHER ROUND OF WINTRY PRECIPITATION WHICH COULD
BE SIGNIFICANT ARE THE PRIMARY CONCERNS IN THIS AFTERNOON/S
FORECAST.
WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES CONTINUE TO
INDICATE SUBTLE MID LEVEL SHORTWAVES EMBEDDED WITHIN SOUTHWEST
FLOW ALOFT ACROSS THE LOWER MISSISSIPPI VALLEY. THIS WILL PROVIDE
A FOCUS FOR PRECIPITATION TONIGHT ACROSS THE MID SOUTH...MAINLY IN
THE FORM OF RAIN. AS TEMPERATURES COOL LATER TONIGHT...THERE IS A
POTENTIAL FOR LIGHT FREEZING DRIZZLE TO DEVELOP ACROSS THE
NORTHERN THIRD OF THE MID SOUTH WHERE MOISTURE IS EXPECTED TO BE
MORE LIMITED. CONFIDENCE ISN/T PARTICULARLY HIGH ENOUGH AT THIS
MOMENT TO CONSIDER HEADLINES BUT THE EVENING SHIFT WILL CONTINUE
TO MONITOR SHORT TERM TRENDS AND ASSESS THE NEED FOR ONE IF
CONDITIONS WARRANT.
NOT MUCH CHANGE IN THE PATTERN IS EXPECTED DURING THE DAY MONDAY
BUT THE MAIN FOCUS FOR RAIN WILL SHIFT SOUTH...MAINLY SOUTH OF
I-40. A WARM FRONT IS EXPECTED TO DEVELOP AND PUSH NORTH ACROSS
THE MID SOUTH MONDAY NIGHT WITH LOW TEMPERATURES OCCURRING DURING
THE EVENING AND GRADUALLY RISING THROUGHOUT THE NIGHT. MODELS
CONTINUE TO INDICATE OVERALL INSTABILITY WILL REMAIN LIMITED AND
KEPT OVERALL THUNDERSTORMS TO MINIMAL MENTION. CONFIDENCE IN
STRONG/THUNDERSTORM POTENTIAL REMAINS LOW ALSO. TEMPERATURES ON
TUESDAY WILL REACH THE UPPER 60S TO PERHAPS THE LOWER 70S SOUTH OF
I-40.
THE MAIN FOCUS FOR THIS WEEK WILL BE THE POTENTIAL OF YET ANOTHER
ROUND OF WINTRY PRECIPITATION THAT IS EXPECTED WEDNESDAY INTO
WEDNESDAY NIGHT...WHICH COULD DEVELOP INTO A SIGNIFICANT WINTER
STORM AS ANOTHER ARCTIC COLD FRONT MOVES THROUGH THE LOWER
MISSISSIPPI VALLEY. THE OPERATIONAL GFS CONTINUES TO BE THE COLDER
OF THE SOLUTIONS WITH THE NAM/CANADIAN BEING SLIGHTLY ON THE WARM
SIDE. OPTED TO USE THE ECMWF AS THE MODEL OF CHOICE AS IT SEEMS TO
BE BLENDING THE SOLUTIONS THE BEST AT THIS TIME. SEVERAL
PRECIPITATION TYPES ARE EXPECTED INCLUDING RAIN...FREEZING
RAIN...SLEET...AND SNOW. EXACT PRECIPITATION TYPES AND AMOUNTS
ARE STILL SOMEWHAT DIFFICULT TO PIN DOWN AT THIS MOMENT DUE TO
MODEL UNCERTAINTY AND SEVERAL CHANGES TO THE FORECAST MAY BE
FORTHCOMING IN SUBSEQUENT FORECASTS. STAY TUNED...
BELOW NORMAL TEMPERATURES ARE EXPECTED BEHIND THE FRONT THROUGH
THE REMAINDER OF THE LONG TERM FORECAST.
CJC
&&
.AVIATION...
06Z TAFS
DRIER AIR HAD WORKED DOWN THE NORTH INTO JBR THIS EVENING...WITH
IMPROVEMENT TO MVFR. HRRR GUIDANCE SUGGEST THE SOUTHWARD CATEGORY
IMPROVEMENT WILL SLOW AND POSSIBLY TOP WITH CIGS PREVAILING NEAR
THE IFR/MVFR THRESHOLD AT MEM TOWARD SUNRISE.
FOR THE DAYTIME MONDAY PERIODS...WENT SLIGHTLY MORE OPTIMISTIC
THAN LAMP GUIDANCE WITH RESPECT TO CIGS AT ALL BUT TUP. CIGS WILL
THEN LIKELY DROP BACK TO IFR MONDAY EVENING...WITH THE APPROACH OF
A MARINE LAYER WARM FRONT FROM THE SOUTH.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
525 AM CST MON MAR 2 2015
.AVIATION...
RAIN WILL CONTINUE TO DEVELOP AND AFFECT MUCH OF THE AREA THROUGH
THE PERIOD. VISBYS SHOULD GRADUALLY IMPROVE LATE THIS MORNING
BEFORE DETERIORATING AGAIN LATE TONIGHT. IFR AND LIFR CEILINGS
WILL BE PREVALENT. WINDS SHOULD BE OUT OF THE NORTHEAST AT AROUND
8-10 KNOTS...BECOMING LIGHT AND VARIABLE TONIGHT. TAFS ALREADY
OUT.
&&
.PREV DISCUSSION... /ISSUED 423 AM CST MON MAR 2 2015/
SHORT TERM...TODAY THROUGH WEDNESDAY
LIGHT SHOWERS HAVE BEEN ONGOING ACROSS SOUTHERN ARKANSAS DURING THE
OVERNIGHT HOURS AND WILL CONTINUE TO SPREAD NORTH THROUGH THE
MORNING HOURS. WRF AND HRRR AGREE WITH PRECIP INCREASING IN AREA
THROUGH 18Z ACROSS MUCH OF SOUTHERN AND SOUTHEAST ARKANSAS.
PRECIPITATION ACROSS THE NORTHERN HALF OF THE STATE SHOULD BE
MINIMAL IF ANYTHING AT ALL. HOWEVER...IF ANY PRECIP DOES FALL
TEMPERATURE PROFILE WOULD SUPPORT FREEZING RAIN. WENT WITH LOW POPS
AND NO ICE ACCUMULATIONS ACROSS NORTH CENTRAL ARKANSAS...WITH NO
POPS ACROSS THE NORTHERN TWO ROWS OF COUNTIES. BY MONDAY
AFTERNOON...PRECIPITATION CHANCES WILL BE SMALL. AS A RESULT WENT
WITH ONLY SLIGHT CHANCE POPS THROUGH 12Z TUESDAY.
BY 12Z TUESDAY...WARM FRONT WILL HAVE LIFTED NORTH THROUGH ARKANSAS
AND BROUGHT A RETURN OF MOIST SOUTHERLY FLOW. WITH THE INCREASE IN
MOISTURE...POPS ALSO BEGIN TO INCREASE. TUESDAY WILL BE THE WARMEST
DAY OF THE WEEK...HOWEVER MODELS AGREE THAT TEMPERATURES MAY NOT BE
AS WARM AS PREVIOUSLY ADVERTISED. DID TREND MAX TEMPS DOWN A COUPLE
OF DEGREES ON TUESDAY...AS A RESULT IT DOES NOT APPEAR ANYWHERE IN
THE STATE WILL TOP 70 DEGREES.
STRONG COLD FRONT WILL ENTER NW ARKANSAS BEFORE 6Z WEDNESDAY...WITH
WINTER WEATHER RETURNING TO THE FORECAST BY 12Z WEDNESDAY.
CONFIDENCE IS INCREASING THAT HAZARDOUS WINTER WEATHER WILL BE
LIKELY WEDNESDAY MORNING THROUGH THURSDAY MORNING. AS A RESULT...A
WINTER STORM WATCH HAS BEEN ISSUED WITH SIGNIFICANT SNOWFALL
EXPECTED.
THE MAIN ISSUE WITH AND MOST DIFFICULT PART OF THE FORECAST WILL BE
THE INITIAL TRANSITION TO WINTRY PRECIPITATION ACROSS THE NORTH WITH
MODELS STRUGGLING TO GET A HANDLE ON HOW MUCH WARM AIR THERE WILL BE
ALOFT. ECMWF AND NAM HAVE A LARGER WARM NOSE WHEN COMPARED TO THE
GFS. FOR THIS FORECAST DID TREND THE FRONTAL TIMING...AND SFC
TEMPERATURE CURVE WITH THE ECMWF...AS WELL AS TEMPERATURES ALOFT.
LOOKING AT SNOWFALL TOTALS...THERE IS SOME CONCERN WHEN LOOKING AT
BOTH GFS AND SREF ENSEMBLE SNOWFALL TOTAL PLUMES. THE MEANS LINE UP
WELL WITH THE CURRENT FORECAST...HOWEVER THERE IS DECENT GROUPING
WITH SOME OF THE SOLUTIONS THAT ARE WELL ABOVE THE MEAN. NEEDLESS TO
SAY...THIS IS SOMETHING THAT WILL NEED TO CONTINUE TO BE WATCHED IN
THE COMING FORECASTS.
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
FRONTAL BOUNDARY SHOULD BE WELL TO THE SOUTH OF THE REGION AT THE
START OF THE PERIOD. PRECIPITATION WILL GRADUALLY WIND DOWN DURING
THE OVERNIGHT HOURS...AND SHOULD LARGELY BE CLEAR OF THE REGION BY
12Z THURSDAY. THERE MIGHT BE BRIEF LIGHT SNOW IN THE FAR SOUTHEAST
THURSDAY MORNING.
COLD TEMPERATURES WILL CONTINUE ON THURSDAY. MODELS CONTINUE TO BE
IN FRIGHTENINGLY GOOD AGREEMENT ON THIS. MOST AREAS WILL ONLY REACH
THE 30S...AND IT IS QUITE LIKELY THAT AREAS WITH THE THICKEST SNOW
PACK WILL STAY BELOW FREEZING. THE COLDEST PERIOD WILL BE THURSDAY
NIGHT/EARLY FRIDAY MORNING...WITH ALL LOCATIONS IN THE TEENS. THERE
MAY EVEN BE A FEW PLACES IN THE SINGLE DIGITS. IT IS ALSO QUITE
LIKELY THAT FRIDAY MORNING...WE WILL BE STARING DOWN THE BARREL OF
DAILY RECORD LOWS IN A FEW PLACES.
THE AIRMASS WILL MODERATE ON FRIDAY AND INTO THE WEEKEND...AS WINDS
TAKE ON MORE OF A SOUTHERLY COMPONENT AND THE HIGH SHIFTS EASTWARD.
HOWEVER...READINGS WILL REMAIN WELL BELOW SEASONAL AVERAGES THROUGH
THE REMAINDER OF THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 40 34 55 35 / 20 30 70 70
CAMDEN AR 41 37 65 51 / 50 30 50 80
HARRISON AR 40 34 56 27 / 10 30 60 50
HOT SPRINGS AR 40 37 59 43 / 50 30 60 70
LITTLE ROCK AR 39 35 59 42 / 40 30 60 80
MONTICELLO AR 43 40 65 53 / 50 40 50 80
MOUNT IDA AR 39 37 58 41 / 50 30 70 70
MOUNTAIN HOME AR 40 33 55 30 / 10 30 60 50
NEWPORT AR 41 36 56 36 / 20 30 70 70
PINE BLUFF AR 39 37 62 46 / 50 30 60 80
RUSSELLVILLE AR 41 35 56 39 / 30 30 70 60
SEARCY AR 38 35 57 39 / 30 30 70 80
STUTTGART AR 39 36 59 42 / 50 30 60 80
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH LATE WEDNESDAY
NIGHT FOR BAXTER-BOONE-FULTON-INDEPENDENCE-IZARD-JACKSON-MARION-
NEWTON-SEARCY-SHARP-STONE.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE
WEDNESDAY NIGHT FOR CLEBURNE-CONWAY-FAULKNER-GARLAND-JOHNSON-
LOGAN-LONOKE-MONROE-MONTGOMERY-PERRY-POLK-POPE-PRAIRIE-PULASKI-
SALINE-SCOTT-VAN BUREN-WHITE-WOODRUFF-YELL.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH LATE WEDNESDAY
NIGHT FOR ARKANSAS-BRADLEY-CALHOUN-CLARK-CLEVELAND-DALLAS-DESHA-
DREW-GRANT-HOT SPRING-JEFFERSON-LINCOLN-OUACHITA-PIKE.
&&
$$
AVIATION...57
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
423 AM CST MON MAR 2 2015
.SHORT TERM...TODAY THROUGH WEDNESDAY
LIGHT SHOWERS HAVE BEEN ONGOING ACROSS SOUTHERN ARKANSAS DURING THE
OVERNIGHT HOURS AND WILL CONTINUE TO SPREAD NORTH THROUGH THE
MORNING HOURS. WRF AND HRRR AGREE WITH PRECIP INCREASING IN AREA
THROUGH 18Z ACROSS MUCH OF SOUTHERN AND SOUTHEAST ARKANSAS.
PRECIPITATION ACROSS THE NORTHERN HALF OF THE STATE SHOULD BE
MINIMAL IF ANYTHING AT ALL. HOWEVER...IF ANY PRECIP DOES FALL
TEMPERATURE PROFILE WOULD SUPPORT FREEZING RAIN. WENT WITH LOW POPS
AND NO ICE ACCUMULATIONS ACROSS NORTH CENTRAL ARKANSAS...WITH NO
POPS ACROSS THE NORTHERN TWO ROWS OF COUNTIES. BY MONDAY
AFTERNOON...PRECIPITATION CHANCES WILL BE SMALL. AS A RESULT WENT
WITH ONLY SLIGHT CHANCE POPS THROUGH 12Z TUESDAY.
BY 12Z TUESDAY...WARM FRONT WILL HAVE LIFTED NORTH THROUGH ARKANSAS
AND BROUGHT A RETURN OF MOIST SOUTHERLY FLOW. WITH THE INCREASE IN
MOISTURE...POPS ALSO BEGIN TO INCREASE. TUESDAY WILL BE THE WARMEST
DAY OF THE WEEK...HOWEVER MODELS AGREE THAT TEMPERATURES MAY NOT BE
AS WARM AS PREVIOUSLY ADVERTISED. DID TREND MAX TEMPS DOWN A COUPLE
OF DEGREES ON TUESDAY...AS A RESULT IT DOES NOT APPEAR ANYWHERE IN
THE STATE WILL TOP 70 DEGREES.
STRONG COLD FRONT WILL ENTER NW ARKANSAS BEFORE 6Z WEDNESDAY...WITH
WINTER WEATHER RETURNING TO THE FORECAST BY 12Z WEDNESDAY.
CONFIDENCE IS INCREASING THAT HAZARDOUS WINTER WEATHER WILL BE
LIKELY WEDNESDAY MORNING THROUGH THURSDAY MORNING. AS A RESULT...A
WINTER STORM WATCH HAS BEEN ISSUED WITH SIGNIFICANT SNOWFALL
EXPECTED.
THE MAIN ISSUE WITH AND MOST DIFFICULT PART OF THE FORECAST WILL BE
THE INITIAL TRANSITION TO WINTRY PRECIPITATION ACROSS THE NORTH WITH
MODELS STRUGGLING TO GET A HANDLE ON HOW MUCH WARM AIR THERE WILL BE
ALOFT. ECMWF AND NAM HAVE A LARGER WARM NOSE WHEN COMPARED TO THE
GFS. FOR THIS FORECAST DID TREND THE FRONTAL TIMING...AND SFC
TEMPERATURE CURVE WITH THE ECMWF...AS WELL AS TEMPERATURES ALOFT.
LOOKING AT SNOWFALL TOTALS...THERE IS SOME CONCERN WHEN LOOKING AT
BOTH GFS AND SREF ENSEMBLE SNOWFALL TOTAL PLUMES. THE MEANS LINE UP
WELL WITH THE CURRENT FORECAST...HOWEVER THERE IS DECENT GROUPING
WITH SOME OF THE SOLUTIONS THAT ARE WELL ABOVE THE MEAN. NEEDLESS TO
SAY...THIS IS SOMETHING THAT WILL NEED TO CONTINUE TO BE WATCHED IN
THE COMING FORECASTS.
&&
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
FRONTAL BOUNDARY SHOULD BE WELL TO THE SOUTH OF THE REGION AT THE
START OF THE PERIOD. PRECIPITATION WILL GRADUALLY WIND DOWN DURING
THE OVERNIGHT HOURS...AND SHOULD LARGELY BE CLEAR OF THE REGION BY
12Z THURSDAY. THERE MIGHT BE BRIEF LIGHT SNOW IN THE FAR SOUTHEAST
THURSDAY MORNING.
COLD TEMPERATURES WILL CONTINUE ON THURSDAY. MODELS CONTINUE TO BE
IN FRIGHTENINGLY GOOD AGREEMENT ON THIS. MOST AREAS WILL ONLY REACH
THE 30S...AND IT IS QUITE LIKELY THAT AREAS WITH THE THICKEST SNOW
PACK WILL STAY BELOW FREEZING. THE COLDEST PERIOD WILL BE THURSDAY
NIGHT/EARLY FRIDAY MORNING...WITH ALL LOCATIONS IN THE TEENS. THERE
MAY EVEN BE A FEW PLACES IN THE SINGLE DIGITS. IT IS ALSO QUITE
LIKELY THAT FRIDAY MORNING...WE WILL BE STARING DOWN THE BARREL OF
DAILY RECORD LOWS IN A FEW PLACES.
THE AIRMASS WILL MODERATE ON FRIDAY AND INTO THE WEEKEND...AS WINDS
TAKE ON MORE OF A SOUTHERLY COMPONENT AND THE HIGH SHIFTS EASTWARD.
HOWEVER...READINGS WILL REMAIN WELL BELOW SEASONAL AVERAGES THROUGH
THE REMAINDER OF THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 40 34 55 35 / 20 30 70 70
CAMDEN AR 41 37 65 51 / 50 30 50 80
HARRISON AR 40 34 56 27 / 10 30 60 50
HOT SPRINGS AR 40 37 59 43 / 50 30 60 70
LITTLE ROCK AR 39 35 59 42 / 40 30 60 80
MONTICELLO AR 43 40 65 53 / 50 40 50 80
MOUNT IDA AR 39 37 58 41 / 50 30 70 70
MOUNTAIN HOME AR 40 33 55 30 / 10 30 60 50
NEWPORT AR 41 36 56 36 / 20 30 70 70
PINE BLUFF AR 39 37 62 46 / 50 30 60 80
RUSSELLVILLE AR 41 35 56 39 / 30 30 70 60
SEARCY AR 38 35 57 39 / 30 30 70 80
STUTTGART AR 39 36 59 42 / 50 30 60 80
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH LATE WEDNESDAY
NIGHT FOR BAXTER-BOONE-FULTON-INDEPENDENCE-IZARD-JACKSON-MARION-
NEWTON-SEARCY-SHARP-STONE.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE
WEDNESDAY NIGHT FOR CLEBURNE-CONWAY-FAULKNER-GARLAND-JOHNSON-
LOGAN-LONOKE-MONROE-MONTGOMERY-PERRY-POLK-POPE-PRAIRIE-PULASKI-
SALINE-SCOTT-VAN BUREN-WHITE-WOODRUFF-YELL.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH LATE WEDNESDAY
NIGHT FOR ARKANSAS-BRADLEY-CALHOUN-CLARK-CLEVELAND-DALLAS-DESHA-
DREW-GRANT-HOT SPRING-JEFFERSON-LINCOLN-OUACHITA-PIKE.
&&
$$
SHORT TERM...65 / LONG TERM...57
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
347 AM MST MON MAR 2 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 338 AM MST MON MAR 2 2015
STG SW FLOW ALOFT WILL CONTINUE TODAY IN ADVANCE OF A WEATHER
DISTURBANCE WHICH WILL MOVE ACROSS NRN AREAS TONIGHT. SHOULD
CONTINUE TO SEE OROGRAPHIC SNOWS IN ZN 31 AND PORTIONS OF ZN 33 THRU
THIS AFTN ALTHOUGH ACTIVITY MAY DECREASE IN ZN 33 BY MIDDAY. OVER
NERN CO A SFC LOW WILL BE NR DENVER WITH GUSTY SLY WINDS DEVELOPING
OVER THE PLAINS WITH DRY CONDITIONS EXPECTED THRU THE AFTN. HIGHS
OVER NERN CO ARE GOING TO BE QUITE VARIABLE DUE TO LINGERING SNOW
COVER IN SOME AREAS. IN ADDITION WITH A SFC LOW NR DENVER
CIRCULATION AROUND THIS LOW MAY ALLOW FOR LOW CLOUD COVER MUCH OF
THE DAY OVER NRN PORTIONS OF THE URBAN CORRIDOR INTO WELD COUNTY.
THUS READINGS OVER NRN AREAS OF URBAN CORRIDOR MAY NOT GET OUT OF
THE LOWER 30S WHILE SRNS ARAS RISE INTO THE LOWER TO MID 40S. OVER
THE PLAINS WHERE SNOW COVER IS LESS READINGS COULD RISE WELL INTO
THE 40S WHERE GUSTY SSW WINDS OCCUR.
FOR TONIGHT A DISTURBANCE WILL TRACK ACROSS THE CO-WY BORDER AREA
WHICH WILL ENHANCE SNOWFALL IN THE MTNS WITH HEAVY SNOW IN ZNS 31
AND 33. OVER NERN CO APPEARS DOWNSLOPE FLOW WILL BE IN PLACE THRU
THE EVENING HOURS BEFORE A STG CDFNT MOVES IN AFTER MIDNIGHT.
TIMING OF THIS FNT IS STILL NOT CERTAIN BUT IT WILL PROBABLY COME IN
FASTER THAN MODELS SHOW ONCE THE DISTURBANCE MOVES EAST OF THE AREA.
FOR NOW WILL HAVE IT NR THE WY BORDER BY MIDNIGHT AND THEN THRU
DENVER BY AROUND 3 AM OR SO. QG FIELDS SHOW STG MID LVL DESCENT
LATE TONIGHT WITH INITIAL FNT PASSAGE SO NOT SURE HOW MUCH PRECIP
WILL DVLP AS BEST CHANCES MAY HOLD OFF UNTIL AFTER 12Z TUE. FOR NOW
WILL KEEP HIGHEST POPS NR THE WY BORDER WITH ONLY CHC POPS AFTER
MIDNIGHT FURTHER SOUTH TOWARDS DENVER.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 346 AM MST MON MAR 2 2015
VERY STRONG WEST-SOUTHWESTERLY FLOW ALOFT IS ON THE DECREASE
TUESDAY FOR THE FORECAST AREA AS AN UPPER TROUGH MOVES THIS WAY.
BY TUESDAY NIGHT LATE...THE AXIS IS OVER THE CWA WITH MODERATE
WESTERLY FLOW AT THE JET LEVEL. THE TROUGH AXIS IS OVER THE FAR
EASTERN CWA BY 18Z WEDNESDAY. THE FLOW ALOFT IS WEAK AND WESTERLY
WEDNESDAY NIGHT WITH ANOTHER WEAK UPPER TROUGH TO OUR IMMEDIATE
WEST. THERE IS WEAK UPWARD QG VERTICAL VELOCITY FOR THE CWA
TUESDAY AFTERNOON THROUGH TUESDAY NIGHT. DOWNWARD SYNOPTIC SCALE
ENERGY IS PROGGED WEDNESDAY AND WEDNESDAY NIGHT. THE BOUNDARY
LAYER FLOW IS STRONG UPSLOPE ON TUESDAY INTO TUESDAY EVENING...
THEN MORE NORMAL DIURNAL PATTERNS ARE EXPECTED OVERNIGHT TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. FOR MOISTURE...IT LOOKS PRETTY DEEP
FOR THE MOUNTAINS TUESDAY MORNING...THEN FOR ALL THE CWA BY
AFTERNOON...CONTINUING THROUGH MUCH OF TUESDAY NIGHT. MODELS HAVE
SLOWED THINGS DOWN A BIT FROM YESTERDAY`S 00Z RUNS. MOISTURE
DECREASES ON WEDNESDAY FROM NORTHWEST TO SOUTH/SOUTHEAST. THINGS
ARE PRETTY MUCH DRIED OUT BY 00Z LATE WEDNESDAY AFTERNOON. THE
QPF FIELDS SHOW A TAD OF MEASURABLE SNOWFALL OVER THE MOUNTAINS
AND NORTHERN PLAINS TUESDAY MORNING...THE OVER THE WESTERN THREE
QUARTERS OF THE CWA BY AFTERNOON. THERE IS A BIT OVER ALL THE CWA
ON ALL THE MODELS ALL TUESDAY NIGHT. THERE IS TINY BIT PROGGED
OVER THE SOUTHERN HALF OF THE CWA WEDNESDAY MORNING. THEN EVEN
LESS JUST FOR THE SOUTH CENTRAL CWA WEDNESDAY AFTERNOON. THERE IS
NOTHING WEDNESDAY NIGHT. FOR POPS...THERE IS SOME HELP FROM
OROGRAPHICS IN THE MOUNTAINS AS WELL AS WEAK SYNOPTIC SCALE ENERGY
AND COLD AIR ADVECTION. WILL GO WITH 80% PLUS POPS TUESDAY INTO
TUESDAY EVENING THERE. THE FOOTHILLS AND ASSOCIATED PLAINS WILL
SEE STRONG COLD AIR ADVECTION AND PRETTY STRONG UPSLOPE IN THE
BOUNDARY LAYER. THE UPSLOPE IS NOT VERY DEEP HOWEVER...UNDER 700
MB ON ALL THE MODELS. WILL NEED 70% PLUS POPS IN THE THOSE AREAS
TO INTO THE EVENING TUESDAY ANYWAY. THE FURTHER EAST IN THE PLAINS
YOU GO WILL NEED LOWER POPS. WILL DIMINISH THE POPS EVERYWHERE
AFTER 06Z TUESDAY NIGHT...WITH SOME "CHANCE"S OF LESS OVER THE
SOUTHERN CWA WEDNESDAY MORNING.. AFTER THAT NO POPS THROUGH THE
EXTENDED. FOR TEMPERATURES...TUESDAY`S HIGHS ARE 9-16 C COLDER
THAN TODAY`S HIGHS. WEDNESDAY`S ARE CLOSE TO TUESDAY`S. FOR THE
LATER DAYS...THURSDAY THROUGH SUNDAY...THERE IS WEAK UPPER LEVEL
FLOW FOR THE CWA. THE DIRECTION OF THE FLOW IS GENERALLY
NORTHWESTERLY ALL FOUR DAYS WITH UPPER RIDGING AROUND. IT STILL
LOOKS DRY ALL FOUR DAYS...BUT TEMPERATURES LOOK TO STAY BELOW
SEASONAL NORMAL.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 338 AM MST MON MAR 2 2015
DENVER CYCLONE WAS LOCATED JUST WEST OF DIA WITH LOW CLOUDS AND
PATCHY FOG TO THE NW...NORTH AND EAST. AT SOME POINT EXPECT LOW
CLOUDS AND FOG WILL EVENTUALLY AFFECT THE AIRPORT ONCE WINDS BECOME
MORE W OR NW IN THE 14Z-15Z TIME PERIOD. MAY SEE DENSE FOG WITH
VISIBILITIES DOWN TO 1/4 FOR A FEW HOURS. LATEST HRRR KEEPS LOW
CLOUDS AND SOME FOG AROUND THRU MUCH OF THE AFTN AS THE CYCLONE IS
LOCATED EAST OF DIA. AS FOR WINDS THEY WILL BECOME LIGHT WNW BY MID
MORNING AND THEN NNW BY MIDDAY THRU MUCH OF THE AFTN.
FOR TONIGHT DEPENDING ON WHERE CIRCULATION CENTER IS COULD STILL SEE
SOME LINGERING LOW CLOUDS IN THE EVENING BEFORE LOW LVL FLOW BECOME
MORE WLY IN ADVANCE OF A CDFNT WHICH WILL ARRIVE AROUND 09Z.
GUSTY NLY WINDS WILL OCCUR WITH THE FNT PASSAGE WITH A CHC OF SOME
LIGHT SNOW HOWEVER AT THIS TIME IT APPEARS BEST CHC FOR SNOW WILL
BE AFTER 12Z ON TUE.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 5 PM MST TUESDAY FOR COZ031.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 5 PM MST
TUESDAY FOR COZ033.
&&
$$
SHORT TERM...RPK
LONG TERM...RJK
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS ALBANY NY
924 AM EST MON MAR 2 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION LATE TODAY INTO EARLY
TUESDAY...BEFORE ANOTHER STORM SYSTEM APPROACHES FROM THE WEST.
THIS SYSTEM IS EXPECTED TO BRING MORE UNSETTLED WEATHER LATE
TUESDAY INTO WEDNESDAY...INCLUDING THE POTENTIAL FOR A WINTRY MIX
OF PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 924 AM EST...THE DEPARTING UPPER LEVEL SHORTWAVE IS TAKING
SOME MOISTURE OFF LAKE ONTARIO TO CAUSE SOME ADDITIONAL SNOW
SHOWERS. THESE ARE BEING ENHANCED BY THE UPSLOPE FLOW INTO THE
HIGH TERRAIN AS WELL. AS A RESULT...A FEW ADDITIONAL SNOW SHOWERS
WILL CONTINUE THIS MORNING...WITH A FRESH COATING OF SNOW POSSIBLE
IN HIGH TERRAIN AREAS. MOST VALLEY AREAS WILL BE DRY WITH A MIX OF
SUN AND CLOUDS AND A PASSING FLURRY IN SPOTS.
MOST OF THE SNOW SHOWERS WILL BE DONE BY THE AFTN...ALTHOUGH THE
LATEST 3KM HRRR SUGGESTS THAT THE SRN ADIRONDACKS AND SRN GREEN
MOUNTAINS COULD SEE AN INSTABILITY-FORCED SNOW SHOWER THIS AFTN IN
SPOTS THANKS TO STRENGTHENING COLD AIR ADVECTION IN PLACE.
WITH THIS STRONG CAA ONGOING...WINDS BECOME STRONG AND GUSTY FROM
THE NORTHWEST. CLOUDS WILL BE SLOW TO ERODE THROUGH THE DAY BUT
THE WINDS SHOULD HELP MIXING...AND HIGHS TODAY ARE EXPECTED TO
REACH THE 30S IN MANY AREAS...WITH 20S IN HIGHER ELEVATIONS. WINDS
COULD GUSTS OVER 30 MPH...ESP FOR THE CAPITAL REGION...BERKSHIRES...AND
OTHER HIGH TERRAIN AREAS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
STRONG GUSTY WINDS WILL GRADUALLY DIMINISH THROUGH THE NIGHT...AND
TREND TO CALM BY DAYBREAK. THE SKY IS EXPECTED TO CLEAR IN MOST
AREAS THROUGH THE NIGHT AS WELL AS RELATIVELY STRONG LOW LEVEL
RIDGING BUILDS IN. THE LIGHT WINDS AND CLEAR SKY SHOULD SUPPORT
LOWS IN THE SINGLE NUMBERS BUT BELOW ZERO IN NORTHERN AREAS.
THE NEXT SYSTEM APPROACHES THROUGH THE DAY TUESDAY WITH
INCREASING AND THICKENING CLOUDS THROUGH THE DAY. BY LATE
AFTERNOON...LIGHT SNOW SHOULD SPREAD ACROSS THE REGION WITH SOME
LIGHT ACCUMULATIONS POSSIBLE THROUGH THROUGH THE AFTERNOON/EVENING
COMMUTE. HIGHS TUESDAY IN THE 20S TO NEAR 30.
PRECIPITATION BECOMES MORE STEADY TUESDAY NIGHT AS A WARM LAYER
ALOFT TRACKS RAPIDLY THROUGH THE REGION. SO...AFTER ABOUT 1-4
INCHES OF SNOW ACROSS THE REGION...PRECIPITATION IS EXPECTED TO
TRANSITION THROUGH A PERIOD OF SLEET AND FREEZING RAIN...
ESPECIALLY ALONG AND SOUTH OF THE MOHAWK VALLEY TO SOUTHERN
VERMONT. PRECIPITATION MAY REMAIN MAINLY SNOW AND SLEET IN THE
SOUTHERN ADIRONDACKS...LAKE GEORGE AND NORTHERN SARATOGA REGION.
ICE ACCUMULATIONS SHOULD BE A TENTH OF AN INCH OR LESS...AND IN
SOME CASES JUST A TRACE...BUT SOME AREAS WHERE SOME ENHANCEMENT
OCCURS MAYBE JUST OVER A TENTH OF AN INCH. THERE IS STILL A LOT OF
UNCERTAINTY AS TO WHAT AREAS HAVE THE BEST CHANCES FOR 4 OR MORE
INCHES OF SNOW AND HOW FAR NORTH ANY FREEZING RAIN CAN GET. SO...
NO WINTER WEATHER ADVISORIES YET...BUT MORE DETAILS WILL BECOME
CLEARER LATER TODAY AND TONIGHT...AND SOME HEADLINES ARE LIKELY AS
THIS EVENT DRAWS NEARER. TEMPERATURES MAY DROP A DEGREE OR TWO
TUESDAY NIGHT...THEN RISE A FEW DEGREES TOWARD DAYBREAK.
STEADY PRECIPITATION IS EXPECTED TO END QUICKLY WEDNESDAY MORNING
AS THE BOUNDARY LAYER THERMAL GRADIENT TRACKS EAST AND SOUTH OF
THE REGION. KEEPING SCATTERED RAIN AND SNOW SHOWERS AS THE LOW
LEVEL COLD FRONT TRACKS THROUGH AND SOME LAKE EFFECT CLOUDINESS
AND SNOW SHOWER ACTIVITY COULD BEGIN TO DEVELOP. WEST TO
NORTHWEST WINDS SHOULD HELP MIXING AND TEMPERATURES SHOULD REACH
THE MID TO UPPER UPPER 30S IN NORTHERN AREAS TO LOWER TO MID 40S
IN SOUTHERN AREAS...DEPENDING ON WHETHER VERY COLD FROZEN GROUND
LIMITS SURFACE WARMING.
A TRAILING PIECE OF UPPER ENERGY TRACKS OFF THE MID ATLANTIC
COAST WEDNESDAY NIGHT...WITH INCREASING FRONTOGENESIS AND FORCING
ALONG AND JUST NORTH OF THE BOUNDARY LAYER THERMAL GRADIENT. THE
NORTHERN PERIPHERY OF THE PRECIPITATION SHIELD COULD EXTEND
THROUGH THE EASTERN CATSKILLS...MID HUDSON VALLEY AND NW CT. LOTS
OF SPREAD IN GUIDANCE FOR THIS POTENTIAL TRAILING SYSTEM. SO
PUTTING HIGH CHANCES FOR SNOW IN SOUTHERN AREAS...AND GENERAL
CHANCES FOR SNOW IN CENTRAL AND NORTHERN AREAS...AS THERE IS A
SMALL CHANCE THAT THIS SYSTEM COULD TRACK FAR ENOUGH NORTH TO GIVE
SOME LIGHT SNOW ACCUMULATIONS A BIT MORE NORTH...BUT AGAIN...
THERE IS LOTS OF UNCERTAINTY AND DETAILS FOR WEDNESDAY NIGHT WILL
GET CLEARER LATER TODAY AND TOMORROW.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THE PERIODS STARTS OUT THURSDAY MORNING WITH A SLOW MOVING FRONTAL
BOUNDARY DRAPED ACROSS THE MID ATLANTIC REGION. A WAVE ALONG THE
FRONT COULD POTENTIALLY SPREAD SOME SNOWFALL ACROSS AT LEAST THE
SOUTHERN HALF OF THE AREA. GFS/ECMWF/GGEM HAVE TRENDED SLIGHTLY
NORTHWARD WITH QPF SO WILL MENTION CHANCE POPS FOR NOW. ALSO PLUME
DIAGRAM FOR ALB FROM THE GFS ENSEMBLES SHOW SEVERAL MEMBERS WITH
AROUND 0.25 INCH QPF AMOUNTS...SO THERE IS UNCERTAINTY.
DETERMINISTIC QPF LOOKS RELATIVELY LIGHT AT THIS TIME...BUT HEAVIER
PRECIP IS FORECAST ACROSS THE MID ATLANTIC REGION. IF THE UPSTREAM
UPPER LEVEL TROUGH BECOMES DEEPER THAN WHAT IS CURRENTLY
FORECAST...THE FRONT/WAVE COULD SPREAD FARTHER NORTH INTO OUR AREA.
WILL HAVE TO WATCH THIS CLOSELY.
BY LATE THURSDAY THIS SYSTEM SHOULD BE EXITING THE EASTERN
SEABOARD...AS THE UPPER TROUGH PUSHES EASTWARD ACROSS THE GREAT
LAKES AND INTO THE NORTHEAST CONUS. A SURFACE RIDGE OF HIGH PRESSURE
LOOKS TO QUICKLY BUILD IN THURSDAY NIGHT...WHICH WILL RESULT IN VERY
COLD TEMPERATURES IN THE SINGLE DIGITS TO BELOW ZERO.
MAINLY DRY WEATHER IS THEN EXPECTED FOR FRIDAY THROUGH SUNDAY...WITH
A GRADUAL MODERATING TREND AS A W-SW FLOW REGIME SETS UP. THERE
COULD BE A FEW SNOW SHOWERS ACROSS THE WESTERN ADIRONDACKS SATURDAY
INTO EARLY SUNDAY...AS A WEAK DISTURBANCE APPROACHES. AFTER A COLD
DAY FRIDAY...TEMPERATURES MAY ACTUALLY WARM TO NEAR NORMAL FOR
SATURDAY INTO SUNDAY AS BOTH THE GFS AND ECMWF ARE INDICATING.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
CYCLONIC NW FLOW REGIME WILL RESULT IN PLENTY OF CLOUDS AND GUSTY
WINDS TODAY. CONDITIONS WILL GENERALLY BE VFR...ALTHOUGH A PERIOD
OF MVFR WILL BE POSSIBLE FOR A SHORT TIME THIS MORNING ESPECIALLY
AT KALB/KPSF WHERE SCT -SHSN WILL OCCUR. SKIES WILL CLEAR TONIGHT
AS HIGH PRESSURE BUILDS IN FROM THE WEST.
WINDS WILL BECOME W-NW AND STEADILY INCREASE TO BETWEEN 12-18 KTS
THIS MORNING WITH GUSTS OF 25 TO 30 KTS COMMON BY THIS AFTERNOON.
STRONGEST WINDS WILL BE AT KALB/KPSF. WIND SPEEDS WILL DECREASE
THIS EVENING AND ESPECIALLY OVERNIGHT AS HIGH PRESSURE APPROACHES.
OUTLOOK...
TUE: MODERATE OPERATIONAL IMPACT. LIKELY SN IN THE AFTERNOON.
TUE NT-WED: MODERATE OPERATIONAL IMPACT. SN/MIXED PCPN TO RAIN.
WED NT-THU: MODERATE OPERATIONAL IMPACT. CHC SN.
FRI: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 5 DAYS. DRY
WEATHER IS EXPECTED THIS AFTERNOON THROUGH TUESDAY MORNING.
HOWEVER...ANOTHER STORM SYSTEM WILL IMPACT THE REGION LATE TUESDAY
INTO WEDNESDAY...WITH THE POSSIBILITY OF SNOW...MIXED
PRECIPITATION AND/OR RAIN.
TEMPERATURES MAY BRIEFLY RISE ABOVE FREEZING DURING THE DAY TODAY...
BEFORE ANOTHER COLD AIR MASS SETTLES IN FOR TONIGHT INTO TUESDAY.
WITH THE CONTINUED COLD CONDITIONS IN PLACE...ICE WILL CONTINUE TO
STRENGTHEN AND THICKEN ON AREA RIVERS...STREAMS...CREEKS...LAKES...
AND PONDS.
A BRIEF WARMUP MAY OCCUR ON WEDNESDAY...BUT THE SHORT TIMING AND
MAGNITUDE OF THE WARMTH WILL LIKELY NOT BE ENOUGH TO CAUSE ANY HYDRO
CONCERNS. ANOTHER COLD AIR MASS WILL BUILD IN LATE WEDNESDAY INTO
THURSDAY...WITH TEMPERATURES FALLING BACK BELOW FREEZING.
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...NAS
NEAR TERM...FRUGIS/NAS
SHORT TERM...NAS
LONG TERM...JPV
AVIATION...JPV
HYDROLOGY...NAS
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
922 AM EST MON MAR 2 2015
.UPDATE...
HAVE MADE SOME MINOR CHANGES TO GRIDS TO UPDATE BASED ON
TRENDS...AND REDUCED POPS ACROSS EXTREME NORTH FOR THE MORNING
HOURS. HAVE SENT A REFRESH TO THE PRODUCTS ALREADY FOR THE
EXPIRATION OF THE DENSE FOG ADVISORY.
TDP
&&
.PREV DISCUSSION... /ISSUED 637 AM EST MON MAR 2 2015/
PREV DISCUSSION... /ISSUED 411 AM EST MON MAR 2 2015/
UPDATE...
NEW OBS HAVE COME IN AND ARE INDICATING THE PATCHY DENSE FOG IS
BECOMING MORE WIDESPREAD. GOING TO ISSUE A DENSE FOG ADVISORY.
PREV DISCUSSION... /ISSUED 344 AM EST MON MAR 2 2015/
SHORT TERM /TODAY THROUGH TUESDAY/...
A COLD FRONT CURRENTLY STRETCHES FROM CENTRAL NEW YORK STATE BACK TO
SOUTHWEST LOUISIANA THIS MORNING. THERE IS SOME SPOTTY PRECIPITATION
ASSOCIATED WITH THE BOUNDARY...CURRENTLY MOVING ACROSS CENTRAL
ALABAMA. THE TREND FOR THE LAST FEW HOURS IS FOR THE PRECIP TO
DWINDLE AS IT MOVES ACROSS THE CWFA. THE HRRR MODEL SUPPORTS THIS
CONTINUING TREND.
WEAK WEDGE WILL CONTINUE TO ERODE AWAY THIS MORNING AS THE COLD
FRONT APPROACHES THE CWFA. EXPECT THE LOW CLOUDS AND FOG TO LIFT A
BIT AFTER SUNRISE...BUT SKIES WILL REMAIN CLOUDY. ANTICIPATE THAT
THE FRONT WILL MOVE ACROSS NORTHERN GEORGIA...AND POSSIBLY MAKE IT
AS FAR SOUTH AS THE ATLANTA METRO BY EARLY AFTERNOON. NOT CONFIDENT
ON EXACTLY WHERE THE FRONT WILL STALL...BUT IT SHOULD BE SOMEWHERE
IN THE VICINITY OF THE INTERSTATE 20 CORRIDOR. TEMPERATURES ON THE
SOUTH SIDE OF THE BOUNDARY WILL BE MUCH WARMER AND HAVE THE
POTENTIAL TO REACH THE MIDDLE TO UPPER 60S IN THE SOUTHERLY
FLOW...NORTH OF THE BOUNDARY TEMPS WILL RANGE FROM THE MIDDLE 40S IN
THE HIGHER ELEVATIONS TO UPPER 50S NEAR CENTRAL GA. THE MAX TEMPS
TODAY WILL DEPEND HIGHLY UPON EXACTLY HOW FAR SOUTH THIS WEAK FRONT
WILL MAKE IT.
WEAK WEDGING WILL TRY AND SET UP IN THE NORTHEAST OVERNIGHT AND
TUESDAY AS HIGH PRESSURE SHIFTS OFFSHORE. THIS WILL CREATE A SHARP
MAX TEMP GRADIENT DURING THE DAY ON TUESDAY. AREAS SOUTH OF THE WEAK
FRONT COULD REACH ALL THE WAY INTO THE LOWER 70S...WHILE AREAS NORTH
OF THE FRONT...IN THE WEDGE...WILL REMAIN THE IN UPPER 40S TO NEAR
50. AGAIN...THE MAX TEMP FORECAST WILL HIGHLY DEPEND UPON WHERE THE
WEAK FRONT AND WEDGE SET UP. THE MORAL OF THE STORY IS...TODAY AND
TUESDAY WILL HAVE HIGH BUST POTENTIAL FOR MAX TEMPS.
AREAS OF FOG AND DRIZZLE SHOULD CONTINUE THROUGH MID MORNING.
VISIBILITIES BETWEEN ONE QUARTER AND ONE HALF OF A MILE ARE POSSIBLE
DURING THE MORNING COMMUTE. IF THE PATCHY DENSE FOG BECOMES MORE
WIDESPREAD...WILL HAVE TO CONSIDER ISSUING A DENSE FOG ADVISORY FOR
PORTIONS OF THE CWFA.
THE HRRR KEEPS MOST OF THE FORECAST AREA PRETTY DRY...WITH JUST
SPOTTY AREAS OF PRECIP TODAY. THE BEST PLACES FOR MEASURABLE
RAINFALL SHOULD BE ALONG THE AL/GA BORDER AND NORTH OF INTERSTATE 20
TODAY. PATCHY LIGHT RAIN AND DRIZZLE IS EXPECTED TO DEVELOP ONCE
AGAIN NORTH OF THE WEAK FRONT OVERNIGHT. BY TUESDAY...A LITTLE
INSTABILITY BEGINS TO DEVELOP ACROSS THE AREA. SOME SURFACE
INSTABILITY IS POSSIBLE SOUTH OF THE BOUNDARY...BUT THERE IS ALSO
SOME POTENTIAL FOR ELEVATED INSTABILITY NORTH OF THE BOUNDARY.
OVERALL...JUST THINK THE MENTION OF A SLIGHT CHANCE OF THUNDER
SHOULD SUFFICE.
NLISTEMAA
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MEDIUM RANGE MODELS REMAIN CONSISTENT AND IN RELATIVELY GOOD
AGREEMENT THROUGH THE MAJORITY OF THE EXTENDED FORECAST PERIOD.
STILL SHOWING THE WORK WEEK DOMINATED BY SOUTHWESTERLY UPPER FLOW
AHEAD OF THE DEEP WESTERN U.S. TROUGH. THIS KEEPS THE REGION IN A
FAIRLY WARM PATTERN UNTIL THURSDAY BEHIND THE SHARP SURFACE FRONT
THE SWEEPS THROUGH WEDNESDAY/WEDNESDAY NIGHT. STILL SEEING ENOUGH
INSTABILITY FOR CHANCE COVERAGE OF THUNDERSTORMS WEDNESDAY. STRONG
LOW/MID-LEVEL WINDS ALSO STILL HAVE ME A BIT CONCERNED ABOUT AT
LEAST ISOLATED SEVERE THUNDERSTORM POTENTIAL. GOOD LOW-LEVEL FORCING
AHEAD OF THE FRONT BUT UPPER SUPPORT IS LACKING WITH THE MAIN UPPER
TROUGH/SHORT WAVE LAGGING FAR BEHIND THE FRONT. GFS AND ECMWF ALSO
STILL INSIST ON BRINGING IN MUCH COLDER AIR AS EARLY AS LATE
WEDNESDAY NIGHT WITH RESIDUAL MOISTURE AND THE INFLUENCE OF THE
UPPER SYSTEM SQUEEZING OUT SOME LOW QPF PRECIPITATION. UPPER FLOW
REMAINS SOUTHWESTERLY THROUGH THURSDAY AND LOWEST THICKNESSES REMAIN
WELL NORTH OF THE STATE. WILL NEED TO WATCH TRENDS FOR THE
POSSIBILITY OF SOME WINTRY MIX ACROSS THE NORTH. GFS AND ECMWF BOTH
SHOW A GOOD TEMPERATURE RECOVERY INTO THE WEEKEND AFTER A THE SHOT
OF COOL AIR THURSDAY THROUGH FRIDAY MORNING AS THE UPPER FLOW
REMAINS GENERALLY ZONAL OVER THE SOUTHEASTERN U.S. AND THE HEART OF
THE COLDEST AIR REMAINS WELL NORTH OF THE STATE. MAINLY DRY AS
WELL...HOWEVER BOTH MODELS SHOW SOME PRECIPITATION POSSIBLY SURGING
NORTH INTO CENTRAL GEORGIA SATURDAY AS SURFACE LOW PRESSURE SPINS UP
OFF THE GEORGIA/CAROLINA COAST. NOT REAL CONFIDENT WE WILL SEE
ANYTHING SIGNIFICANT WITH THIS BUT SLIGHT CHANCE OR LOW CHANCE POPS
MAY BE APPROPRIATE.
20
AVIATION...
12Z UPDATE...
VSBYS CURRENTLY BOUNCING AROUND ACROSS THE NORTHERN TERMINAL
SITES. VSBYS COULD LOWER BACK DOWN TO AROUND 1/2SM AROUND
SUNRISE. CIGS AND VSBYS SHOULD IMPROVE BY MID MORNING AS A FRONT
APPROACHES. MVFR CIGS POSSIBLE FOR A BRIEF TIME THIS
AFTERNOON...AND THEN LOWER AGAIN THIS EVENING TO IFR AND POSSIBLY
LIFR OVERNIGHT AS RAIN MOVES IN. WINDS ARE EXPECTED TO SHIFT TO
THE NW BY MID MORNING ALSO. SPEEDS SHOULD BE RATHER LIGHT AND
AVERAGE 6KT OR LESS. A WIND SHIFT TO THE NE IS LIKELY OVERNIGHT.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 63 46 50 48 / 40 60 70 50
ATLANTA 58 49 60 55 / 40 60 60 40
BLAIRSVILLE 53 44 48 48 / 90 60 70 70
CARTERSVILLE 52 46 56 53 / 60 60 70 60
COLUMBUS 65 58 73 59 / 40 30 20 20
GAINESVILLE 59 45 48 46 / 40 60 70 60
MACON 66 56 69 57 / 20 40 40 20
ROME 49 45 57 54 / 80 60 60 60
PEACHTREE CITY 59 51 62 56 / 40 40 40 30
VIDALIA 69 57 69 60 / 20 30 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
637 AM EST MON MAR 2 2015
.PREV DISCUSSION... /ISSUED 411 AM EST MON MAR 2 2015/
UPDATE...
NEW OBS HAVE COME IN AND ARE INDICATING THE PATCHY DENSE FOG IS
BECOMING MORE WIDESPREAD. GOING TO ISSUE A DENSE FOG ADVISORY.
PREV DISCUSSION... /ISSUED 344 AM EST MON MAR 2 2015/
SHORT TERM /TODAY THROUGH TUESDAY/...
A COLD FRONT CURRENTLY STRETCHES FROM CENTRAL NEW YORK STATE BACK TO
SOUTHWEST LOUISIANA THIS MORNING. THERE IS SOME SPOTTY PRECIPITATION
ASSOCIATED WITH THE BOUNDARY...CURRENTLY MOVING ACROSS CENTRAL
ALABAMA. THE TREND FOR THE LAST FEW HOURS IS FOR THE PRECIP TO
DWINDLE AS IT MOVES ACROSS THE CWFA. THE HRRR MODEL SUPPORTS THIS
CONTINUING TREND.
WEAK WEDGE WILL CONTINUE TO ERODE AWAY THIS MORNING AS THE COLD
FRONT APPROACHES THE CWFA. EXPECT THE LOW CLOUDS AND FOG TO LIFT A
BIT AFTER SUNRISE...BUT SKIES WILL REMAIN CLOUDY. ANTICIPATE THAT
THE FRONT WILL MOVE ACROSS NORTHERN GEORGIA...AND POSSIBLY MAKE IT
AS FAR SOUTH AS THE ATLANTA METRO BY EARLY AFTERNOON. NOT CONFIDENT
ON EXACTLY WHERE THE FRONT WILL STALL...BUT IT SHOULD BE SOMEWHERE
IN THE VICINITY OF THE INTERSTATE 20 CORRIDOR. TEMPERATURES ON THE
SOUTH SIDE OF THE BOUNDARY WILL BE MUCH WARMER AND HAVE THE
POTENTIAL TO REACH THE MIDDLE TO UPPER 60S IN THE SOUTHERLY
FLOW...NORTH OF THE BOUNDARY TEMPS WILL RANGE FROM THE MIDDLE 40S IN
THE HIGHER ELEVATIONS TO UPPER 50S NEAR CENTRAL GA. THE MAX TEMPS
TODAY WILL DEPEND HIGHLY UPON EXACTLY HOW FAR SOUTH THIS WEAK FRONT
WILL MAKE IT.
WEAK WEDGING WILL TRY AND SET UP IN THE NORTHEAST OVERNIGHT AND
TUESDAY AS HIGH PRESSURE SHIFTS OFFSHORE. THIS WILL CREATE A SHARP
MAX TEMP GRADIENT DURING THE DAY ON TUESDAY. AREAS SOUTH OF THE WEAK
FRONT COULD REACH ALL THE WAY INTO THE LOWER 70S...WHILE AREAS NORTH
OF THE FRONT...IN THE WEDGE...WILL REMAIN THE IN UPPER 40S TO NEAR
50. AGAIN...THE MAX TEMP FORECAST WILL HIGHLY DEPEND UPON WHERE THE
WEAK FRONT AND WEDGE SET UP. THE MORAL OF THE STORY IS...TODAY AND
TUESDAY WILL HAVE HIGH BUST POTENTIAL FOR MAX TEMPS.
AREAS OF FOG AND DRIZZLE SHOULD CONTINUE THROUGH MID MORNING.
VISIBILITIES BETWEEN ONE QUARTER AND ONE HALF OF A MILE ARE POSSIBLE
DURING THE MORNING COMMUTE. IF THE PATCHY DENSE FOG BECOMES MORE
WIDESPREAD...WILL HAVE TO CONSIDER ISSUING A DENSE FOG ADVISORY FOR
PORTIONS OF THE CWFA.
THE HRRR KEEPS MOST OF THE FORECAST AREA PRETTY DRY...WITH JUST
SPOTTY AREAS OF PRECIP TODAY. THE BEST PLACES FOR MEASURABLE
RAINFALL SHOULD BE ALONG THE AL/GA BORDER AND NORTH OF INTERSTATE 20
TODAY. PATCHY LIGHT RAIN AND DRIZZLE IS EXPECTED TO DEVELOP ONCE
AGAIN NORTH OF THE WEAK FRONT OVERNIGHT. BY TUESDAY...A LITTLE
INSTABILITY BEGINS TO DEVELOP ACROSS THE AREA. SOME SURFACE
INSTABILITY IS POSSIBLE SOUTH OF THE BOUNDARY...BUT THERE IS ALSO
SOME POTENTIAL FOR ELEVATED INSTABILITY NORTH OF THE BOUNDARY.
OVERALL...JUST THINK THE MENTION OF A SLIGHT CHANCE OF THUNDER
SHOULD SUFFICE.
NLISTEMAA
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MEDIUM RANGE MODELS REMAIN CONSISTENT AND IN RELATIVELY GOOD
AGREEMENT THROUGH THE MAJORITY OF THE EXTENDED FORECAST PERIOD.
STILL SHOWING THE WORK WEEK DOMINATED BY SOUTHWESTERLY UPPER FLOW
AHEAD OF THE DEEP WESTERN U.S. TROUGH. THIS KEEPS THE REGION IN A
FAIRLY WARM PATTERN UNTIL THURSDAY BEHIND THE SHARP SURFACE FRONT
THE SWEEPS THROUGH WEDNESDAY/WEDNESDAY NIGHT. STILL SEEING ENOUGH
INSTABILITY FOR CHANCE COVERAGE OF THUNDERSTORMS WEDNESDAY. STRONG
LOW/MID-LEVEL WINDS ALSO STILL HAVE ME A BIT CONCERNED ABOUT AT
LEAST ISOLATED SEVERE THUNDERSTORM POTENTIAL. GOOD LOW-LEVEL FORCING
AHEAD OF THE FRONT BUT UPPER SUPPORT IS LACKING WITH THE MAIN UPPER
TROUGH/SHORT WAVE LAGGING FAR BEHIND THE FRONT. GFS AND ECMWF ALSO
STILL INSIST ON BRINGING IN MUCH COLDER AIR AS EARLY AS LATE
WEDNESDAY NIGHT WITH RESIDUAL MOISTURE AND THE INFLUENCE OF THE
UPPER SYSTEM SQUEEZING OUT SOME LOW QPF PRECIPITATION. UPPER FLOW
REMAINS SOUTHWESTERLY THROUGH THURSDAY AND LOWEST THICKNESSES REMAIN
WELL NORTH OF THE STATE. WILL NEED TO WATCH TRENDS FOR THE
POSSIBILITY OF SOME WINTRY MIX ACROSS THE NORTH. GFS AND ECMWF BOTH
SHOW A GOOD TEMPERATURE RECOVERY INTO THE WEEKEND AFTER A THE SHOT
OF COOL AIR THURSDAY THROUGH FRIDAY MORNING AS THE UPPER FLOW
REMAINS GENERALLY ZONAL OVER THE SOUTHEASTERN U.S. AND THE HEART OF
THE COLDEST AIR REMAINS WELL NORTH OF THE STATE. MAINLY DRY AS
WELL...HOWEVER BOTH MODELS SHOW SOME PRECIPITATION POSSIBLY SURGING
NORTH INTO CENTRAL GEORGIA SATURDAY AS SURFACE LOW PRESSURE SPINS UP
OFF THE GEORGIA/CAROLINA COAST. NOT REAL CONFIDENT WE WILL SEE
ANYTHING SIGNIFICANT WITH THIS BUT SLIGHT CHANCE OR LOW CHANCE POPS
MAY BE APPROPRIATE.
20
&&
.AVIATION...
12Z UPDATE...
VSBYS CURRENTLY BOUNCING AROUND ACROSS THE NORTHERN TERMINAL
SITES. VSBYS COULD LOWER BACK DOWN TO AROUND 1/2SM AROUND
SUNRISE. CIGS AND VSBYS SHOULD IMPROVE BY MID MORNING AS A FRONT
APPROACHES. MVFR CIGS POSSIBLE FOR A BRIEF TIME THIS
AFTERNOON...AND THEN LOWER AGAIN THIS EVENING TO IFR AND POSSIBLY
LIFR OVERNIGHT AS RAIN MOVES IN. WINDS ARE EXPECTED TO SHIFT TO
THE NW BY MID MORNING ALSO. SPEEDS SHOULD BE RATHER LIGHT AND
AVERAGE 6KT OR LESS. A WIND SHIFT TO THE NE IS LIKELY OVERNIGHT.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 63 46 50 48 / 40 60 70 50
ATLANTA 58 49 60 55 / 40 60 60 40
BLAIRSVILLE 53 44 48 48 / 90 60 70 70
CARTERSVILLE 52 46 56 53 / 60 60 70 60
COLUMBUS 65 58 73 59 / 40 30 20 20
GAINESVILLE 59 45 48 46 / 40 60 70 60
MACON 66 56 69 57 / 20 40 40 20
ROME 49 45 57 54 / 80 60 60 60
PEACHTREE CITY 59 51 62 56 / 40 40 40 30
VIDALIA 69 57 69 60 / 20 30 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR THE FOLLOWING
ZONES: BALDWIN...BANKS...BARROW...BARTOW...BIBB...BLECKLEY...
BUTTS...CARROLL...CHATTAHOOCHEE...CHEROKEE...CLARKE...CLAYTON...
COBB...COWETA...CRAWFORD...CRISP...DEKALB...DODGE...DOOLY...
DOUGLAS...EMANUEL...FAYETTE...FORSYTH...GLASCOCK...GREENE...
GWINNETT...HALL...HANCOCK...HARALSON...HARRIS...HEARD...HENRY...
HOUSTON...JACKSON...JASPER...JEFFERSON...JOHNSON...JONES...
LAMAR...LAURENS...MACON...MADISON...MARION...MERIWETHER...
MONROE...MONTGOMERY...MORGAN...MUSCOGEE...NEWTON...NORTH
FULTON...OCONEE...OGLETHORPE...PAULDING...PEACH...PIKE...POLK...
PULASKI...PUTNAM...ROCKDALE...SCHLEY...SOUTH FULTON...SPALDING...
STEWART...SUMTER...TALBOT...TALIAFERRO...TAYLOR...TELFAIR...
TOOMBS...TREUTLEN...TROUP...TWIGGS...UPSON...WALTON...WARREN...
WASHINGTON...WEBSTER...WHEELER...WILCOX...WILKES...WILKINSON.
&&
$$
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1022 AM EST MON MAR 2 2015
.SYNOPSIS...
A COLD FRONT WITH LIMITED MOISTURE WILL MOVE THROUGH THE AREA
TODAY. HIGH PRESSURE BEHIND THE FRONT WILL BUILD INTO THE AREA
FROM THE NORTH TONIGHT INTO TUESDAY. A WARM FRONT WILL MOVE NORTH
THROUGH THE AREA TUESDAY INTO TUESDAY NIGHT. A STRONG COLD FRONT
WILL MOVE THROUGH THE AREA THURSDAY. HIGH PRESSURE WILL BUILD INTO
THE REGION FROM THE NORTH FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1020 AM MON...CLEARING LINE STEADILY WORKING TO THE
SOUTHEAST ACROSS THE MIDSTATE REGION AT PRESENT. VISIBILITIES ARE
SLOWLY COMING UP BUT LOW CLOUDS WILL LIKELY PERSIST INTO EARLY
AFTERNOON UNTIL THE FRONT SWEEPS THROUGH. CURRENT FORECAST ON
TRACK.
FOR TODAY...REINFORCING COLD FRONT WILL PUSH THROUGH E NC LATE
THIS MORNING/EARLY AFTERNOON. NOT MUCH FORCING OR MOISTURE
ASSOCIATED WITH THE FRONT THOUGH NOT ENOUGH CONFIDENCE TO REMOVE
THE INHERITED 20 POP FROM GRIDS. ANY ISOLATED SHOWERS WILL MOVE
OFFSHORE WITH THE FRONT AFTER AROUND NOON TODAY...FOLLOWED BY
PARTIAL CLEARING FROM NW TO SE AS COLUMN DRIES. BASED ON LOW LEVEL
THICKNESS VALS AND MO CLOUDY SKIES FOR A BETTER PART OF THE DAY...
SHOULD SEE HIGHS IN THE 50S (LOW 50S NE TO UPPER 50S SW).
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 330 AM MON...SKIES SHOULD BE MOSTLY CLEAR TO START THE
NIGHT AS TRANSITORY HIGH SCOOTS BY TO THE NORTH. MUCH DRIER AIR
MASS WILL FILTER INTO THE REGION WITH LIGHT WINDS...AND OVERNIGHT
LOWS WILL FALL WELL INTO THE 30S. TEMPS MAY BOTTOM OUT AROUND
MIDNIGHT BEFORE LEVELLING OFF AND THEN RISING TOWARDS DAYBREAK AS
INC ISENTROPIC LIFT OCCURS DUE TO WARMING ALOFT AND INC MID/HIGH
CLOUD COVER MOVES IN FROM THE SW.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...AN ACTIVE WEATHER PATTERN IS EXPECTED THIS
WEEK AS TRANSIENT SYSTEMS IN A SPLIT FLOW REGIME AFFECT THE
FORECAST AREA. LARGE SWINGS IN TEMPERATURE WILL BRING SPRINGLIKE
WARMTH DURING MIDWEEK FOLLOWED BY A CHANCE OF WINTRY PRECIP AND
COLD ON THURSDAY. THE UNSEASONABLY COLD TEMPERATURES WILL PREVAIL
THROUGH LATE IN THE WEEK.
HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTH INTO EARLY TUESDAY.
A WARM FRONT IS THEN FORECAST TO SLOWLY RETREAT TO THE NORTH
TUESDAY AFTERNOON AND EVENING. PATCHY TO PERHAPS WIDEPSREAD LIGHT
RAIN IS EXPECTED AS THE BOUNDARY TRAVERSES THE AREA INTO TUESDAY
EVENING. LATEST GUIDANCE SUGGESTS THAT PRECIPITATION HOLDS OFF
UNTIL SURFACE WARNS ABOVE FREEZING TUESDAY SO NOT EXPECTING ANY P
TYPE ISSUES ALTHOUGH THERE IS LIKELY TO BE A LARGE TEMPERATURE
GRADIENT ACROSS THE AREA AS THE WEDGE INLAND RETARDS THE FRONTAL
PROGRESS UNTIL EVENING. THUS THE IMMEDIATE COAST COULD MAKE INTO
THE 60S LATE WHILE DEEPER INLAND LOCATIONS REMAIN IN THE 40S. THE
WARM FRONT IS FORECAST TO FINALLY MOVE NORTH OF THE AREA TUESDAY
NIGHT AS THE WEDGE ERODES WITH TEMPERATURES LIKELY WARMING INTO
THE 60S THROUGHOUT THE AREA. THUS WILL NEED TO FORECAST A NON
DIURNAL TEMPERATURE CYCLE WITH TUESDAYS "HIGHS" LIKELY TO BE
TUESDAY NIGHTS "LOWS" AS THE WARM SECTOR SURGES NORTH ACROSS
EASTERN NC.
MODELS ARE IN GOOD AGREEMENT FOR UNSEASONABLY MILD TEMPERATURES (FOR
A CHANGE) ON WEDNESDAY WITH HIGHS INTO THE 70S AWAY FROM ANY
COOLING ONSHORE BREEZES. COULD SEE SEA FOG/STRATUS ALONG THE SOUTH
FACING COASTLINES WHICH COULD LIMIT TEMPERATURES. THE MODELS
CONTINUE TO TREND LATER WITH RAIN CHANCES TO LATE WEDNESDAY INTO
WED NIGHT AS AN ANA FRONT TYPE PRECIP REGIME SETS UP BEHIND THE
INCOMING SFC BNDRY.
THERE ARE LARGE DIFFERENCES IN THE MODELS REGARDING THE SPEED OF
A STRONG COLD FRONT WHICH WILL MOVE THROUGH THE AREA THURSDAY. THE
GFS IS CONSIDERED TOO FAST WITH THE FRONT MAKING IT TO THE CRYSTAL
COAST BY 12Z THURSDAY WHILE THE NAM IS CONSIDERED TOO SLOW WITH
THE FRONT STILL WEST OF THE COASTAL PLAIN AT THIS TIME. THE ECMWF
WAS THE COMPROMISE CHOICE WITH THE FRONT MOVING INTO THE NW ZONES
LATE WEDNESDAY NIGHT AND THEN THROUGH THE REMAINDER OF THE AREA
LATE THURSDAY MORNING. PRECIP CHANCES SHOULD INCREASE AS THE
FRONT MOVES THRU AND BRINGS THE NEXT ROUND OF ARCTIC AIR TO THE
REGION. THERMAL PROFILES FAVOR A CHANGEOVER TO FROZEN
PRECIPITATION FROM NORTH TO SOUTH DURING THURSDAY BEFORE ENDING
LATER THU AFTERNOON OR EVENING AND WILL CONTINUE A LOW CONFIDENCE
CHANCE OF SNOW AND SLEET. TOO EARLY TO GET INTO MUCH DETAIL ABOUT
POSSIBLE ACCUMULATIONS AS YET BUT PRECIP LOOKS TO BE MOVING THRU
QUICKLY WHICH WOULD LIMIT AMOUNTS.
PRECIP ENDS LATE THU/THU EVENING FROM NW TO SE, WITH STRONG HIGH
PRESSURE BUILDING EAST OVER THE REGION FROM THE TENNESSEE VALLEY
AREA INTO SATURDAY. THICKNESSES FALL QUICKLY BEHIND THE FRONT FRIDAY
WITH HIGHS ONLY EXPECTED IN THE 40S FRIDAY AND UPPER 40S TO LOWER
50S SATURDAY/SUNDAY. LOWS THU AND FRIDAY WILL DROP WELL INTO THE 20S.
THE FORECAST FOR LATE IN THE WEEKEND IS VERY UNCERTAIN WITH A
LARGE SPREAD IN THE GUIDANCE (GFS DRY/ECMWF WETTER). WILL
CONTINUE TO INDICATE DRY WEATHER SUNDAY UNTIL PERIOD COMES INTO
BETTER FOCUS.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1020 AM SUN...VSBYS SLOWLY COMING UP BUT LIFR/IFR CIGS
PERSISTING. CONDITIONS LOOK TO SLOWLY IMPROVE THIS MORNING WITH
MVFR LATE MORNING THEN FINALLY VFR BY AROUND NOON. COLD FRONT WILL
MOVE THROUGH THE TERMINALS EARLY AFTERNOON WITH WINDS VEERING
NORTH 10KT POSSIBLY GUSTING A LITTLE HIGHER. MAINLY CLEAR SKIES
EARLY THIS EVENING WITH SCT/BKN HIGH CLOUDS AND LIGHT NE WINDS.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...DRIER AIR SPREADS INTO THE AREA WITH VFR
CONDITIONS EXPECTED INTO EARLY TUESDAY THEN A WARM FRONT WILL
RETREAT SLOWLY TO THE NORTH TUESDAY AFTERNOON AND EVENING WITH
POSSIBLY SOME LOWER FLIGHT CATEGORIES AS MOISTURE INCREASES OVER
THE AREA WITH PATCHY TO WIDESPREAD LIGHT RAIN EXPECTED. A COLD
FRONT WILL APPROACH FROM THE WEST WEDNESDAY NIGHT AS SURFACE FLOW
SHIFTS SOUTHWEST AND MAY BECOME GUSTY WEDNESDAY AFTERNOON WITH
ONLY WIDELY SCATTERED RAIN SHOWERS FORECAST. A STRONG COLD FRONT
WILL CROSS THE REGION LATE WED NIGHT AND MOVE OFFSHORE THU. GOOD
CVRG OF RAIN WED NIGHT AND EARLY THU WITH PRECIP DIMINISHING
LATE...POSS MIXED WITH SOME SNOW OR SLEET INLAND. SUB VFR
CONDITIONS ARE A GOOD BET LATER WED NIGHT AND MUCH OF THU. STRONG
HIGH PRESSURE BUILDS IN FOR A RETURN TO PREDOMINANT VFR CONDITIONS
LATE IN THE WEEK.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 7 AM MON. CURRENT OBS SHOWING SEAS 3 TO 5 FT WITH A WSW
WIND 10 TO 15 KT. MAINTAINING DENSE FOG ADVISORY THROUGH 10AM FOR
ALL WATERS AS VSBYS RANGING GENERALLY 1/2 TO 2 MILES. FOR
TODAY...THE WSW WINDS WILL BECOME NORTH THIS AFTERNOON AND INC
BEHIND A COLD FRONT. WE EXPECT A NORTHERLY SURGE THIS
AFTERNOON...AND RIGHT NOW ALL BUT ALBEMARLE SOUND AND THE RIVERS
SHOULD SEE SCA DEVELOPING. HRRR AND NSSL WRF INDICATE ENOUGH OF A
SURGE TO PRODUCE SCA WIND GUSTS EASTERN PAMLICO SOUND BEGINNING
AROUND 18Z. THE GUSTY WINDS WILL SLOWLY VEER NE AND DIMINISH
TONIGHT...WITH VARIOUS SCA HEADLINES ENDING AROUND 9Z AS SEAS TAKE
A BIT LONGER TO RESPOND TO DIMINISHING WINDS.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...STRONG WINDS AND ROUGH SEAS WILL PREVAIL
OVER THE MARINE AREA DURING THE PERIOD AS A SERIES OF WEATHER
SYSTEMS TRAVERSE THE WATERS. WINDS WILL BRIEFLY DIMINISH TUE MORN
THEN BEGIN TO RAMP UP FROM THE S LATE TUE AS A WARM FRONT LIFTS N
THRU THE AREA. SEAS WILL DIMINISH EARLY TUE THEN BUILD BACK UP TO
4 TO 6 FT BY TUE EVENING HIGHEST FAR OUTER CNTRL WTRS. GUSTY SSW
WINDS WILL DEVELOP TUE NIGHT AND CONT WED AHEAD OF APPROACHING
COLD FRONT...SEAS WILL BUILD TO 5 TO 9 FEET OUTER WTRS WED. THE
COLD FRONT WILL CROSS THE EASTERN NC COASTAL WATERS LATE WEDNESDAY
NIGHT/EARLY THU WITH STRONG HIGH PRESSURE BUILDING IN FROM THE
WEST THURSDAY, LEADING TO GUSTY N WINDS THU WITH SEAS OF 5 TO 9
FEET. WINDS/SEAS WILL SLOWLY DECREASE AS COLD AIR ADVECTION WANES
LATE FRIDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST TUESDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM EST
TUESDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR AMZ150.
&&
$$
SYNOPSIS...JME/TL
NEAR TERM...HSA/TL
SHORT TERM...TL
LONG TERM...JME/BTC
AVIATION...HSA/TL/JME
MARINE...HSA/TL/JME
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
700 AM EST MON MAR 2 2015
.SYNOPSIS...
A COLD FRONT WITH LIMITED MOISTURE WILL MOVE THROUGH THE AREA
TODAY. HIGH PRESSURE BEHIND THE FRONT WILL BUILD INTO THE AREA
FROM THE NORTH TONIGHT INTO TUESDAY. A WARM FRONT WILL MOVE NORTH
THROUGH THE AREA TUESDAY INTO TUESDAY NIGHT. A STRONG COLD FRONT
WILL MOVE THROUGH THE AREA THURSDAY. HIGH PRESSURE WILL BUILD INTO
THE REGION FROM THE NORTH FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 7 AM MON...CURRENTLY...MOST AREAS STILL ABOVE 1/4 MILE
VISIBILITY DUE TO LIGHT WRLY WINDS KEEPING SFC A BIT MIXED...AND
WILL MAINTAIN SPS FOR FOG THROUGH 10AM.
FOR TODAY...REINFORCING COLD FRONT WILL PUSH THROUGH E NC LATE
THIS MORNING/EARLY AFTERNOON. NOT MUCH FORCING OR MOISTURE
ASSOCIATED WITH THE FRONT THOUGH NOT ENOUGH CONFIDENCE TO REMOVE
THE INHERITED 20 POP FROM GRIDS. ANY ISOLATED SHOWERS WILL MOVE
OFFSHORE WITH THE FRONT AFTER AROUND NOON TODAY...FOLLOWED BY
PARTIAL CLEARING FROM NW TO SE AS COLUMN DRIES. BASED ON LOW LEVEL
THICKNESS VALS AND MO CLOUDY SKIES FOR A BETTER PART OF THE DAY...
SHOULD SEE HIGHS IN THE 50S (LOW 50S NE TO UPPER 50S SW).
&&
.SHORT TERM /TONIGHT/...
AS OF 330 AM MON...SKIES SHOULD BE MOSTLY CLEAR TO START THE
NIGHT AS TRANSITORY HIGH SCOOTS BY TO THE NORTH. MUCH DRIER AIR
MASS WILL FILTER INTO THE REGION WITH LIGHT WINDS...AND OVERNIGHT
LOWS WILL FALL WELL INTO THE 30S. TEMPS MAY BOTTOM OUT AROUND
MIDNIGHT BEFORE LEVELLING OFF AND THEN RISING TOWARDS DAYBREAK AS
INC ISENTROPIC LIFT OCCURS DUE TO WARMING ALOFT AND INC MID/HIGH
CLOUD COVER MOVES IN FROM THE SW.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...AN ACTIVE WEATHER PATTERN IS EXPECTED THIS
WEEK AS TRANSIENT SYSTEMS IN A SPLIT FLOW REGIME AFFECT THE
FORECAST AREA. LARGE SWINGS IN TEMPERATURE WILL BRING SPRINGLIKE
WARMTH DURING MIDWEEK FOLLOWED BY A CHANCE OF WINTRY PRECIP AND
COLD ON THURSDAY. THE UNSEASONABLY COLD TEMPERATURES WILL PREVAIL
THROUGH LATE IN THE WEEK.
HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTH INTO EARLY TUESDAY.
A WARM FRONT IS THEN FORECAST TO SLOWLY RETREAT TO THE NORTH
TUESDAY AFTERNOON AND EVENING. PATCHY TO PERHAPS WIDEPSREAD LIGHT
RAIN IS EXPECTED AS THE BOUNDARY TRAVERSES THE AREA INTO TUESDAY
EVENING. LATEST GUIDANCE SUGGESTS THAT PRECIPITATION HOLDS OFF
UNTIL SURFACE WARNS ABOVE FREEZING TUESDAY SO NOT EXPECTING ANY P
TYPE ISSUES ALTHOUGH THERE IS LIKELY TO BE A LARGE TEMPERATURE
GRADIENT ACROSS THE AREA AS THE WEDGE INLAND RETARDS THE FRONTAL
PROGRESS UNTIL EVENING. THUS THE IMMEDIATE COAST COULD MAKE INTO
THE 60S LATE WHILE DEEPER INLAND LOCATIONS REMAIN IN THE 40S. THE
WARM FRONT IS FORECAST TO FINALLY MOVE NORTH OF THE AREA TUESDAY
NIGHT AS THE WEDGE ERODES WITH TEMPERATURES LIKELY WARMING INTO
THE 60S THROUGHOUT THE AREA. THUS WILL NEED TO FORECAST A NON
DIURNAL TEMPERATURE CYCLE WITH TUESDAYS "HIGHS" LIKELY TO BE
TUESDAY NIGHTS "LOWS" AS THE WARM SECTOR SURGES NORTH ACROSS
EASTERN NC.
MODELS ARE IN GOOD AGREEMENT FOR UNSEASONABLY MILD TEMPERATURES (FOR
A CHANGE) ON WEDNESDAY WITH HIGHS INTO THE 70S AWAY FROM ANY
COOLING ONSHORE BREEZES. COULD SEE SEA FOG/STRATUS ALONG THE SOUTH
FACING COASTLINES WHICH COULD LIMIT TEMPERATURES. THE MODELS
CONTINUE TO TREND LATER WITH RAIN CHANCES TO LATE WEDNESDAY INTO
WED NIGHT AS AN ANA FRONT TYPE PRECIP REGIME SETS UP BEHIND THE
INCOMING SFC BNDRY.
THERE ARE LARGE DIFFERENCES IN THE MODELS REGARDING THE SPEED OF
A STRONG COLD FRONT WHICH WILL MOVE THROUGH THE AREA THURSDAY. THE
GFS IS CONSIDERED TOO FAST WITH THE FRONT MAKING IT TO THE CRYSTAL
COAST BY 12Z THURSDAY WHILE THE NAM IS CONSIDERED TOO SLOW WITH
THE FRONT STILL WEST OF THE COASTAL PLAIN AT THIS TIME. THE ECMWF
WAS THE COMPROMISE CHOICE WITH THE FRONT MOVING INTO THE NW ZONES
LATE WEDNESDAY NIGHT AND THEN THROUGH THE REMAINDER OF THE AREA
LATE THURSDAY MORNING. PRECIP CHANCES SHOULD INCREASE AS THE
FRONT MOVES THRU AND BRINGS THE NEXT ROUND OF ARCTIC AIR TO THE
REGION. THERMAL PROFILES FAVOR A CHANGEOVER TO FROZEN
PRECIPITATION FROM NORTH TO SOUTH DURING THURSDAY BEFORE ENDING
LATER THU AFTERNOON OR EVENING AND WILL CONTINUE A LOW CONFIDENCE
CHANCE OF SNOW AND SLEET. TOO EARLY TO GET INTO MUCH DETAIL ABOUT
POSSIBLE ACCUMULATIONS AS YET BUT PRECIP LOOKS TO BE MOVING THRU
QUICKLY WHICH WOULD LIMIT AMOUNTS.
PRECIP ENDS LATE THU/THU EVENING FROM NW TO SE, WITH STRONG HIGH
PRESSURE BUILDING EAST OVER THE REGION FROM THE TENNESSEE VALLEY
AREA INTO SATURDAY. THICKNESSES FALL QUICKLY BEHIND THE FRONT FRIDAY
WITH HIGHS ONLY EXPECTED IN THE 40S FRIDAY AND UPPER 40S TO LOWER
50S SATURDAY/SUNDAY. LOWS THU AND FRIDAY WILL DROP WELL INTO THE 20S.
THE FORECAST FOR LATE IN THE WEEKEND IS VERY UNCERTAIN WITH A
LARGE SPREAD IN THE GUIDANCE (GFS DRY/ECMWF WETTER). WILL
CONTINUE TO INDICATE DRY WEATHER SUNDAY UNTIL PERIOD COMES INTO
BETTER FOCUS.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 7 AM SUN...WIDESPREAD LIFR CONDITIONS CURRENTLY WITH
CEILINGS 2-500 FT. IN ADDITION TO THE LOW CIGS AREAS OF LIGHT
FOG/BR WITH VSBYS 1 TO 2 MILES ARE OCCURRING. A LIGHT SW TO W WIND
PREVENTING WIDESPREAD DENSE FOG. CONDITIONS LOOK TO SLOWLY
IMPROVE THIS MORNING WITH MVFR MID TO LATE MORNING THEN FINALLY
VFR BY AROUND NOON. COLD FRONT WILL MOVE THROUGH THE TERMINALS
EARLY AFTERNOON WITH WINDS VEERING NORTH 10KT POSSIBLY GUSTING A
LITTLE HIGHER. MAINLY CLEAR SKIES EARLY THIS EVENING WITH SCT/BKN
HIGH CLOUDS AND LIGHT NE WINDS.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...DRIER AIR SPREADS INTO THE AREA WITH VFR
CONDITIONS EXPECTED INTO EARLY TUESDAY THEN A WARM FRONT WILL
RETREAT SLOWLY TO THE NORTH TUESDAY AFTERNOON AND EVENING WITH
POSSIBLY SOME LOWER FLIGHT CATEGORIES AS MOISTURE INCREASES OVER
THE AREA WITH PATCHY TO WIDESPREAD LIGHT RAIN EXPECTED. A COLD
FRONT WILL APPROACH FROM THE WEST WEDNESDAY NIGHT AS SURFACE FLOW
SHIFTS SOUTHWEST AND MAY BECOME GUSTY WEDNESDAY AFTERNOON WITH
ONLY WIDELY SCATTERED RAIN SHOWERS FORECAST. A STRONG COLD FRONT
WILL CROSS THE REGION LATE WED NIGHT AND MOVE OFFSHORE THU. GOOD
CVRG OF RAIN WED NIGHT AND EARLY THU WITH PRECIP DIMINISHING
LATE...POSS MIXED WITH SOME SNOW OR SLEET INLAND. SUB VFR
CONDITIONS ARE A GOOD BET LATER WED NIGHT AND MUCH OF THU. STRONG
HIGH PRESSURE BUILDS IN FOR A RETURN TO PREDOMINANT VFR CONDITIONS
LATE IN THE WEEK.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 7 AM MON. CURRENT OBS SHOWING SEAS 3 TO 5 FT WITH A WSW
WIND 10 TO 15 KT. MAINTAINING DENSE FOG ADVISORY THROUGH 10AM FOR
ALL WATERS AS VSBYS RANGING GENERALLY 1/2 TO 2 MILES. FOR
TODAY...THE WSW WINDS WILL BECOME NORTH THIS AFTERNOON AND INC
BEHIND A COLD FRONT. WE EXPECT A NORTHERLY SURGE THIS
AFTERNOON...AND RIGHT NOW ALL BUT ALBEMARLE SOUND AND THE RIVERS
SHOULD SEE SCA DEVELOPING. HRRR AND NSSL WRF INDICATE ENOUGH OF A
SURGE TO PRODUCE SCA WIND GUSTS EASTERN PAMLICO SOUND BEGINNING
AROUND 18Z. THE GUSTY WINDS WILL SLOWLY VEER NE AND DIMINISH
TONIGHT...WITH VARIOUS SCA HEADLINES ENDING AROUND 9Z AS SEAS TAKE
A BIT LONGER TO RESPOND TO DIMINISHING WINDS.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...STRONG WINDS AND ROUGH SEAS WILL PREVAIL
OVER THE MARINE AREA DURING THE PERIOD AS A SERIES OF WEATHER
SYSTEMS TRAVERSE THE WATERS. WINDS WILL BRIEFLY DIMINISH TUE MORN
THEN BEGIN TO RAMP UP FROM THE S LATE TUE AS A WARM FRONT LIFTS N
THRU THE AREA. SEAS WILL DIMINISH EARLY TUE THEN BUILD BACK UP TO
4 TO 6 FT BY TUE EVENING HIGHEST FAR OUTER CNTRL WTRS. GUSTY SSW
WINDS WILL DEVELOP TUE NIGHT AND CONT WED AHEAD OF APPROACHING
COLD FRONT...SEAS WILL BUILD TO 5 TO 9 FEET OUTER WTRS WED. THE
COLD FRONT WILL CROSS THE EASTERN NC COASTAL WATERS LATE WEDNESDAY
NIGHT/EARLY THU WITH STRONG HIGH PRESSURE BUILDING IN FROM THE
WEST THURSDAY, LEADING TO GUSTY N WINDS THU WITH SEAS OF 5 TO 9
FEET. WINDS/SEAS WILL SLOWLY DECREASE AS COLD AIR ADVECTION WANES
LATE FRIDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR AMZ130-131-
135>137-150-152-154-156-158.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 1 AM EST
TUESDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM EST
TUESDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 4 AM EST
TUESDAY FOR AMZ150.
&&
$$
SYNOPSIS...JME/TL
NEAR TERM...TL
SHORT TERM...TL
LONG TERM...JME/BTC
AVIATION...JME/BTC/TL
MARINE...JME/BTC/TL
AREA FORECAST DISCUSSION
NWS MEDFORD OR
305 AM PST MON MAR 2 2015
.DISCUSSION...A WEAK SHORTWAVE WILL QUICKLY MOVE SOUTH ALONG THE
OREGON COAST THIS MORNING. SO FAR MEASURABLE RAINFALL HAS BEEN
CONFINED TO THE COAST. RADAR SHOWS RETURNS INLAND OVER
JOSEPHINE...WESTERN JACKSON AND SISKIYOU COUNTY, BUT DEWPOINTS
STILL REMAIN LOW, SO SUSPECT LITTLE IF ANYTHING IS REACHING THE
GROUND. THE RAP KEEPS MOST OF THE PRECIPIATION OFFSHORE, BUT IT
DOES SHOW SOME QPF WEST OF THE CASCADES. THE HRRR RADAR REFLECTIVITY
ALSO SHOWS LIGHT RETURNS IN THE SAME AREAS, BUT SUSPECT IT`S
SUGGESTING VIRGA. THEREFORE WE`LL CONTINUE TO KEEP THE HIGHEST
POPS OVER THE WATERS AND COAST WITH A SLIGHT CHANCE FURTHER INLAND
IN DOUGLAS...JOSEPHINE AND WESTERN JASCKSON COUNTY.
THE SHORTWAVE WILL MOVE SOUTH LATE THIS MORNING WITH DRY
CONDITIONS EXPECTED MOST LOCATIONS THE REST OF THE DAY. A FEW
SHOWERS ARE POSSIBLE FOR THE CASCADES AND SISKIYOUS IN THE
AFTERNOON WITH LITTLE IF ANY QPF.
THE MODELS ARE IN GOOD AGREEMENT ADVERTISING A DRY AND MILD
PATTERN FOR THE REST OF THE WEEK THROUGH NEXT WEEKEND. AN UPPER
RIDGE NEAR 140 W WILL SHIFT EAST AND STRENGTHEN THE LATTER PART OF
THE WEEK INTO NEXT WEEKEND. GUIDANCE SUGGEST TEMPERATURES IN
MEDFORD COULD GET NEAR 70 DEGREES WHICH IS ABOUT 14 DEGREES ABOVE
CLIMO. IT`S POSSIBLE IT COULD HAPPEN WITH TEMPERATURES WARMING
ALOFT. MODELS SHOW 850 MB TEMPERATURES WARMING FRIDAY INTO NEXT
WEEKEND WITH THE GFS SHOWING TEMPERATURES NEAR 12C SATURDAY...13C
SUNDAY AND NEXT MONDAY. -PETRUCELLI
&&
.AVIATION...FOR THE 02/06Z TAF CYCLE...A FRONT WILL BRING LIGHT RAIN
TO THE COAST AND WESTERN UMPQUA OVERNIGHT ALONG WITH MVFR CIGS AND
POSSIBLE MVFR VIS. THE FRONT WILL BRING CLOUDS AND SPOTTY RAIN TO
OTHER AREAS OF THE WEST SIDE OVERNIGHT, BUT CONDITIONS ELSEWHERE ARE
EXPECTED TO REMAIN VFR THROUGH MONDAY. -WRIGHT
&&
.MARINE...UPDATED 230 AM PST, MONDAY, 2 MAR, 2015...HIGH CONFIDENCE
EXISTS THAT AREAS OF MODERATE NORTHERLY WINDS WILL PERSIST THROUGH
WEDNESDAY AND WILL BE STRONGEST DURING THE AFTERNOONS AND EVENINGS
BEYOND 5 NM AND SOUTH OF CAPE BLANCO. A DISTURBANCE ALOFT WILL BRING
LIGHT RAIN TO THE AREA THIS MORNING. THE PATTERN OF A THERMAL TROUGH
AT THE COAST AND HIGH PRESSURE OFFSHORE WILL DEVELOP AGAIN TUESDAY
WITH NORTHERLY CHOP. WINDS ARE EXPECTED TO WEAKEN LATE IN THE WEEK
AS THE HIGH BUILDS EASTWARD. /FB
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 7 PM THIS EVENING TO 1 AM
PST TUESDAY FOR PZZ356.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST THIS
EVENING FOR PZZ350-356.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 PM PST THIS EVENING FOR
PZZ370.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST TUESDAY
FOR PZZ370-376.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 1 AM PST TUESDAY FOR
PZZ376.
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
440 AM CST MON MAR 2 2015
...SIGNIFICANT WINTER STORM TO IMPACT THE MIDSOUTH MIDWEEK...
.DISCUSSION...
CURRENTLY...1035MB HIGH PRESSURE SITUATED OVER NORTHERN MISSOURI
THIS MORNING WITH AN INVERTED TROF/STATIONARY FRONT EXTENDING FROM
NRN ALABAMA INTO THE LOWER MS VALLEY. DRIER...COLDER AIR IS
WORKING INTO THE NORTHERN HALF OF THE MIDSOUTH ON BRISK NORTH
WINDS. SEEMS LIKE THE WINDOW FOR ANY FREEZING RAIN OR DRIZZLE IS
CLOSING WITH THIS ADVECTION OF LOW LEVEL DRY AIR INTO NORTHERN
AREAS. PATCHY LIGHT RAIN AND FOG IS COMMON ACROSS NE MS NEAR THE
FRONTAL BOUNDARY. TEMPS RANGE FROM THE UPPER 20S NORTH TO THE
LOWER 50S ACROSS MONROE COUNTY INVOF FRONTAL BOUNDARY.
TODAY...ANOTHER COLD DAY ACROSS THE MIDSOUTH AS THE SURFACE HIGH
TRAVELS FROM THE MID MS VALLEY INTO THE OHIO VALLEY. THIS WILL
KEEP THE MIDSOUTH IN COOL NE FLOW. EXPECT SOME SUN ACROSS THE
NORTHERN TIER WITH CLOUDS AND SCATTERED RAIN AND DRIZZLE ACROSS
THE SOUTH. TEMPS WILL RANGE FROM AROUND 40 IN NE AR TO THE UPPER
40S IN MONROE COUNTY. TEMPS WILL BE FALLING THERE FOR THE NEXT FEW
HOURS AS THE BOUNDARY SHIFTS SOUTH.
TONIGHT AND TUESDAY...FRONTAL BOUNDARY WILL LIFT NORTH AS A WARM
FRONT LATER TONIGHT AND EARLY TUESDAY BRINGING A RESPITE FROM
THIS COLD SNAP. TEMPS WILL SLOWLY RISE TONIGHT WITH A CHANCE OF
SHOWERS AND THEN CLIMB INTO THE 60S AND MAYBE SOME LOWER 70S
ACROSS SOUTHERN AREAS ON TUESDAY AFTERNOON. AS A COLD FRONT
APPROACHES EXPECT NUMEROUS SHOWERS AND A FEW THUNDERSTORMS TO
DEVELOP OVER THE NW HALF OF THE MIDSOUTH THROUGH THE DAY.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...AN ARCTIC FRONT WILL PUSH
ACROSS THE MIDSOUTH. EXPECT RAIN...HEAVY AT TIMES TUESDAY NIGHT AS
PRECIPITATION SHIFTS POST FRONTAL AND STRONG OVERRUNNING
COMMENCES. 00Z MODELS ARE DISPLAY SIMILAR IDEAS THOUGH THERE ARE
TIMING DIFFERENCES. FAVORED THE ECMWF TIMING WHICH IS IN BETWEEN
THE FAST GFS AND MUCH SLOWER NAM. BY 12Z WED EXPECT THE FRONT TO
BE LOCATED FROM SAVANNAH TO CLARKSDALE. THROUGH THE DAY THE COLD
AIR WILL DEEPEN WITH RAIN TRANSITIONING TO FREEZING RAIN...SLEET
AND EVENTUALLY SNOW. ALL THE MODELS HAVE HEAVY AMOUNTS OF QPF
BEHIND THE FRONT WITH A GOOD DEAL AS FREEZING RAIN...SLEET AND
SNOW. THE PERIOD OF FREEZING RAIN SHOULD BE SHORT LIVED ACROSS
NORTHERN AREAS AS THE COLD AIR DEEPENS QUICKLY AND TRANSITIONS TO
SLEET. A LITTLE MORE FREEZING IS LIKELY ACROSS SOUTHERN
AREAS...AROUND A TENTH OR SO BEFORE CHANGING OVER TO SLEET. THERE
IS A SIGNIFICANT WARM LAYER ALOFT TO OVERCOME SO IT SEEMS THAT
MUCH OF THE WINTER PRECIP WILL FALL IN THE FORM OF SLEET BEFORE
EVENTUALLY CHANGING TO SNOW. COULD SEE SEVERAL INCHES OF SLEET AND
SNOW ACROSS THE NORTH HALF OF THE MIDSOUTH WITH LESSER...THOUGH
STILL SIGNIFICANT AMOUNTS...TO THE SOUTH. TEMPS WILL BE FALLING
INTO THE 20S DURING THE DAY. ISSUED A WINTER STORM WATCH ALONG AND
NORTH OF A LINE FROM SAVANNAH TN TO CLARKSDALE STARTING EARLY WED
FOR NORTHERN LOCATIONS AND AROUND NOON ALONG THE I-40 CORRIDOR AND
CONTINUING THROUGH WEDNESDAY NIGHT. LIKELY THAT THE WATCH WILL
NEED TO BE EXTENDED FURTHER SOUTH OVER THE NEXT DAY OR SO.
THURSDAY AND FRIDAY...LINGERING SNOW SHOWERS WILL END IN THE
MORNING WITH VERY COLD AIR BUILDING IN FOR THE END OF THE WEEK.
TEMPS WILL BE WAY BELOW NORMAL...EVEN MORE SO IF THERE IS ANY KIND
OF SIGNIFICANT SNOW PACK.
SATURDAY AND SUNDAY...00Z GFS KEEPS COOL HIGH PRESSURE OVER THE
AREA THROUGH THE WEEKEND WHILE THE ECWMF HAS A SYSTEM MOVING OUT
OF THE SOUTHERN PLAINS. SMALL POPS WILL BE INTRODUCED.
SJM
&&
.AVIATION...
06Z TAFS
DRIER AIR HAD WORKED DOWN THE NORTH INTO JBR THIS EVENING...WITH
IMPROVEMENT TO MVFR. HRRR GUIDANCE SUGGEST THE SOUTHWARD CATEGORY
IMPROVEMENT WILL SLOW AND POSSIBLY TOP WITH CIGS PREVAILING NEAR
THE IFR/MVFR THRESHOLD AT MEM TOWARD SUNRISE.
FOR THE DAYTIME MONDAY PERIODS...WENT SLIGHTLY MORE OPTIMISTIC
THAN LAMP GUIDANCE WITH RESPECT TO CIGS AT ALL BUT TUP. CIGS WILL
THEN LIKELY DROP BACK TO IFR MONDAY EVENING...WITH THE APPROACH OF
A MARINE LAYER WARM FRONT FROM THE SOUTH.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH LATE WEDNESDAY
NIGHT FOR CLAY-CRAIGHEAD-CROSS-GREENE-LAWRENCE-MISSISSIPPI-
POINSETT-RANDOLPH.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE
WEDNESDAY NIGHT FOR CRITTENDEN-LEE AR-PHILLIPS-ST. FRANCIS.
MO...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH LATE WEDNESDAY
NIGHT FOR DUNKLIN-PEMISCOT.
MS...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE
WEDNESDAY NIGHT FOR ALCORN-BENTON MS-COAHOMA-DESOTO-
MARSHALL-PANOLA-QUITMAN-TATE-TIPPAH-TUNICA.
TN...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH LATE WEDNESDAY
NIGHT FOR CROCKETT-DYER-GIBSON-HENRY-LAKE-LAUDERDALE-OBION-
WEAKLEY.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE
WEDNESDAY NIGHT FOR BENTON TN-CARROLL-CHESTER-DECATUR-
FAYETTE-HARDEMAN-HARDIN-HAYWOOD-HENDERSON-MADISON-MCNAIRY-
SHELBY-TIPTON.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
1100 AM CST MON MAR 2 2015
.DISCUSSION...
OVERALL SHORT TERM FORECAST ON TRACK. CLOUDY WITH LIGHT RAIN AND
SHOWERS EXPECTED TODAY OVER MAINLY CENTRAL TO SOUTHERN AR. SHORTWAVE
WILL GRADUALLY MOVE THROUGH THE AREA...AND RAIN CHANCES WILL LOWER
THIS AFTERNOON. THEN A WARM FRONT IS EXPECTED TO LIFT NORTHWARD
LATER TODAY AND TONIGHT AND KEEP SMALL CHANCES OF RAIN IN THE
FORECAST. TEMPS TONIGHT REMAIN ABOVE FREEZING THEREFORE ONLY RAIN IS
FORECAST. MOST UNCERTAINTY IS WITH THE WEDNESDAY TO THURSDAY
FORECAST WITH RAIN STARTING...THEN COLDER AIR FILTERS IN OVER AR
FROM THE NORTH WITH A COLD FRONT...AND WINTER WEATHER WILL BE SEEN.
AMOUNT OF MOISTURE WILL BE THE KEY...AND AMOUNTS OF SNOW...FREEZING
RAIN AND SLEET ALL DEPEND ON THE AVAILABLE MOISTURE. CURRENT WINTER
STORM WATCH IS IN EFFECT WITH THE POTENTIAL OF 1-3, 2-4, 4 TO 6 INCH
SNOW AMOUNTS WITH ISOLATED HIGHER AMOUNTS...AND ICING POTENTIAL WITH
LESS THAN A TENTH...A FEW TENTHS...TO SOUTHERN AREAS POSSIBLY
REACHING A QUARTER OR HIGHER ICING AMOUNTS. OTHERWISE...WILL UPDATE
FORECAST WITH IN LATE MORNING WITH ONLY MINOR CHANGES EXPECTED AT
THIS TIME. (59)
&&
.PREV DISCUSSION... /ISSUED 525 AM CST MON MAR 2 2015/
.AVIATION...
RAIN WILL CONTINUE TO DEVELOP AND AFFECT MUCH OF THE AREA THROUGH
THE PERIOD. VISBYS SHOULD GRADUALLY IMPROVE LATE THIS MORNING
BEFORE DETERIORATING AGAIN LATE TONIGHT. IFR AND LIFR CEILINGS
WILL BE PREVALENT. WINDS SHOULD BE OUT OF THE NORTHEAST AT AROUND
8-10 KNOTS...BECOMING LIGHT AND VARIABLE TONIGHT. TAFS ALREADY
OUT.
&&
.PREV DISCUSSION... /ISSUED 423 AM CST MON MAR 2 2015/
SHORT TERM...TODAY THROUGH WEDNESDAY
LIGHT SHOWERS HAVE BEEN ONGOING ACROSS SOUTHERN ARKANSAS DURING THE
OVERNIGHT HOURS AND WILL CONTINUE TO SPREAD NORTH THROUGH THE
MORNING HOURS. WRF AND HRRR AGREE WITH PRECIP INCREASING IN AREA
THROUGH 18Z ACROSS MUCH OF SOUTHERN AND SOUTHEAST ARKANSAS.
PRECIPITATION ACROSS THE NORTHERN HALF OF THE STATE SHOULD BE
MINIMAL IF ANYTHING AT ALL. HOWEVER...IF ANY PRECIP DOES FALL
TEMPERATURE PROFILE WOULD SUPPORT FREEZING RAIN. WENT WITH LOW POPS
AND NO ICE ACCUMULATIONS ACROSS NORTH CENTRAL ARKANSAS...WITH NO
POPS ACROSS THE NORTHERN TWO ROWS OF COUNTIES. BY MONDAY
AFTERNOON...PRECIPITATION CHANCES WILL BE SMALL. AS A RESULT WENT
WITH ONLY SLIGHT CHANCE POPS THROUGH 12Z TUESDAY.
BY 12Z TUESDAY...WARM FRONT WILL HAVE LIFTED NORTH THROUGH ARKANSAS
AND BROUGHT A RETURN OF MOIST SOUTHERLY FLOW. WITH THE INCREASE IN
MOISTURE...POPS ALSO BEGIN TO INCREASE. TUESDAY WILL BE THE WARMEST
DAY OF THE WEEK...HOWEVER MODELS AGREE THAT TEMPERATURES MAY NOT BE
AS WARM AS PREVIOUSLY ADVERTISED. DID TREND MAX TEMPS DOWN A COUPLE
OF DEGREES ON TUESDAY...AS A RESULT IT DOES NOT APPEAR ANYWHERE IN
THE STATE WILL TOP 70 DEGREES.
STRONG COLD FRONT WILL ENTER NW ARKANSAS BEFORE 6Z WEDNESDAY...WITH
WINTER WEATHER RETURNING TO THE FORECAST BY 12Z WEDNESDAY.
CONFIDENCE IS INCREASING THAT HAZARDOUS WINTER WEATHER WILL BE
LIKELY WEDNESDAY MORNING THROUGH THURSDAY MORNING. AS A RESULT...A
WINTER STORM WATCH HAS BEEN ISSUED WITH SIGNIFICANT SNOWFALL
EXPECTED.
THE MAIN ISSUE WITH AND MOST DIFFICULT PART OF THE FORECAST WILL BE
THE INITIAL TRANSITION TO WINTRY PRECIPITATION ACROSS THE NORTH WITH
MODELS STRUGGLING TO GET A HANDLE ON HOW MUCH WARM AIR THERE WILL BE
ALOFT. ECMWF AND NAM HAVE A LARGER WARM NOSE WHEN COMPARED TO THE
GFS. FOR THIS FORECAST DID TREND THE FRONTAL TIMING...AND SFC
TEMPERATURE CURVE WITH THE ECMWF...AS WELL AS TEMPERATURES ALOFT.
LOOKING AT SNOWFALL TOTALS...THERE IS SOME CONCERN WHEN LOOKING AT
BOTH GFS AND SREF ENSEMBLE SNOWFALL TOTAL PLUMES. THE MEANS LINE UP
WELL WITH THE CURRENT FORECAST...HOWEVER THERE IS DECENT GROUPING
WITH SOME OF THE SOLUTIONS THAT ARE WELL ABOVE THE MEAN. NEEDLESS TO
SAY...THIS IS SOMETHING THAT WILL NEED TO CONTINUE TO BE WATCHED IN
THE COMING FORECASTS.
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
FRONTAL BOUNDARY SHOULD BE WELL TO THE SOUTH OF THE REGION AT THE
START OF THE PERIOD. PRECIPITATION WILL GRADUALLY WIND DOWN DURING
THE OVERNIGHT HOURS...AND SHOULD LARGELY BE CLEAR OF THE REGION BY
12Z THURSDAY. THERE MIGHT BE BRIEF LIGHT SNOW IN THE FAR SOUTHEAST
THURSDAY MORNING.
COLD TEMPERATURES WILL CONTINUE ON THURSDAY. MODELS CONTINUE TO BE
IN FRIGHTENINGLY GOOD AGREEMENT ON THIS. MOST AREAS WILL ONLY REACH
THE 30S...AND IT IS QUITE LIKELY THAT AREAS WITH THE THICKEST SNOW
PACK WILL STAY BELOW FREEZING. THE COLDEST PERIOD WILL BE THURSDAY
NIGHT/EARLY FRIDAY MORNING...WITH ALL LOCATIONS IN THE TEENS. THERE
MAY EVEN BE A FEW PLACES IN THE SINGLE DIGITS. IT IS ALSO QUITE
LIKELY THAT FRIDAY MORNING...WE WILL BE STARING DOWN THE BARREL OF
DAILY RECORD LOWS IN A FEW PLACES.
THE AIRMASS WILL MODERATE ON FRIDAY AND INTO THE WEEKEND...AS WINDS
TAKE ON MORE OF A SOUTHERLY COMPONENT AND THE HIGH SHIFTS EASTWARD.
HOWEVER...READINGS WILL REMAIN WELL BELOW SEASONAL AVERAGES THROUGH
THE REMAINDER OF THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 40 34 55 35 / 20 30 70 70
CAMDEN AR 41 37 65 51 / 50 30 50 80
HARRISON AR 40 34 56 27 / 10 30 60 50
HOT SPRINGS AR 40 37 59 43 / 50 30 60 70
LITTLE ROCK AR 39 35 59 42 / 40 30 60 80
MONTICELLO AR 43 40 65 53 / 50 40 50 80
MOUNT IDA AR 39 37 58 41 / 50 30 70 70
MOUNTAIN HOME AR 40 33 55 30 / 10 30 60 50
NEWPORT AR 41 36 56 36 / 20 30 70 70
PINE BLUFF AR 39 37 62 46 / 50 30 60 80
RUSSELLVILLE AR 41 35 56 39 / 30 30 70 60
SEARCY AR 38 35 57 39 / 30 30 70 80
STUTTGART AR 39 36 59 42 / 50 30 60 80
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH LATE WEDNESDAY
NIGHT FOR BAXTER-BOONE-FULTON-INDEPENDENCE-IZARD-JACKSON-MARION-
NEWTON-SEARCY-SHARP-STONE.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE
WEDNESDAY NIGHT FOR CLEBURNE-CONWAY-FAULKNER-GARLAND-JOHNSON-
LOGAN-LONOKE-MONROE-MONTGOMERY-PERRY-POLK-POPE-PRAIRIE-PULASKI-
SALINE-SCOTT-VAN BUREN-WHITE-WOODRUFF-YELL.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH LATE WEDNESDAY
NIGHT FOR ARKANSAS-BRADLEY-CALHOUN-CLARK-CLEVELAND-DALLAS-DESHA-
DREW-GRANT-HOT SPRING-JEFFERSON-LINCOLN-OUACHITA-PIKE.
&&
$$
AVIATION...57
AREA FORECAST DISCUSSION
NWS TUCSON AZ
925 AM MST MON MAR 2 2015
.SYNOPSIS...A STRONG LOW PRESSURE SYSTEM NEAR CENTRAL AND SOUTHERN
CALIFORNIA WILL BRING WINDY CONDITIONS AS WELL AS PERIODS OF VALLEY
RAIN AND MOUNTAIN SNOW BY MID DAY TODAY THROUGH TONIGHT.
PRECIPITATION CHANCES WILL LESSEN CONSIDERABLY FOR MIDWEEK WITH DRY
CONDITIONS AREAWIDE AND WARMER TEMPERATURES BY THE END OF THE WEEK.
&&
.DISCUSSION...9 AM WATER VAPOR IMAGERY THIS MORNING SHOWED THE UPPER
LOW JUST OFF THE SRN CA COAST. BASED ON TRENDS THE CENTER HAS
STOPPED DIGGING S AND IS MOVING ENE. IT WILL OPEN UP AS IT MOVES ENE
ACROSS SRN CA THIS MORNING AND UP INTO NRN AZ THIS AFTERNOON.
REGIONAL DOPPLER RADARS PAINTED SHOWERS ACROSS WRN AZ MOVING SLOWLY
TO THE E. AREAS OF MODERATE RAIN ARE IN THIS BAND WITH AJO RECORDING
0.35" BETWEEN 8 AND 9 AM. BASED ON CURRENT MOVEMENT AND HRRR DATA
THE LEADING EDGE OF THIS BAND OF SHOWERS WILL BE MOVING INTO SE
PINAL/ERN PIMA/SANTA CRUZ COUNTY BETWEEN 1 AND 3 PM...GIVE OR TAKE
AN HOUR. THE CENTRAL TO NE MOUNTAINS WILL START A LITTLE EARLIER DUE
TO THE STRONG UPSLOPE FLOW. SNOW LEVELS WILL BE CRASHING THIS
AFTERNOON...DOWN TO AROUND 6500 FEET WITH SNOW PICKING UP IN
INTENSITY. WILL MAINTAIN CURRENT WINTER STORM FOR THE WHITES AND
WINTER WEATHER ADVISORIES PINALENO/CATALINA/RINCON MTNS THAT GO INTO
EFFECT AFTER 11 AM. WIND ALSO AN ISSUE TODAY ESPECIALLY IN THE
MOUNTAINS AND COCHISE COUNTY WHERE A WIND ADVISORY IS IN EFFECT.
HAVE SEE SOME WIND GUSTS IN THE MOUNTAINS IN THE 30-45 MPH RANGE
THIS MORNING. SHOWER ACTIVITY CONTINUING THIS EVENING ACROSS ERN
ZONES BEFORE ENDING EARLY TUESDAY MORNING. MORE ON THE REST OF THE
FORECAST IN THE AFTERNOON DISCUSSION.
&&
.AVIATION...VALID THRU 03/12Z.
AN APPROACHING STORM SYSTEM WILL BE IMPACTING THE AREA THRU THIS
EVENING. EXPECT SCT CUMULUS NEAR 4-6K FT AGL WITH BKN-OVC LAYERS ABV
THROUGH 25K FT...THEN AFT 02/18Z BECOMING BKN-OVC 4-6K FT WITH
MULTIPLE LAYERS ABV AND IFR/MVFR CONDS OVER MTNS AND NEAR SHOWERS.
ISOLD SHOWERS THIS MORNING WILL BECOME WIDESPREAD THIS AFTERNOON.
CLOUDS AND SHOWERS DIMINISHING FROM THE WEST BEHIND THE COLD FRONT
WHICH WILL BE NEAR KTUS 02/23Z AND KDUG NEAR 03/05Z. SFC WINDS S
8-16 KTS THEN INCREASING TO 15-25 KTS WITH HIGHER GUSTS TO 40 KTS IN
ADVANCE OF APPROACHING COLD FRONT. STRONG SOUTHERLY JET TODAY WITH
WINDS 30-50 KTS 5-10K FT MSL. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.
&&
.FIRE WEATHER...STRONG GUSTY WINDS...ESPECIALLY IN THE MOUNTAINS AND
THE LOWER ELEVATIONS S AND E OF TUCSON...WILL CONTINUE INTO THIS
EVENING BEFORE DIMINISHING. SHOWERS OVER WESTERN PIMA COUNTY THIS
MORNING WILL CONTINUE TO PUSH EAST ACROSS SE AZ AS A COLD FRONT
MOVES EAST. THE SHOWERS WILL DIMINISH TONIGHT AS THE COLD FRONT
MOVES INTO NEW MEXICO. ANOTHER WEATHER SYSTEM WILL IMPACT THE AREA
ON WEDNESDAY FOR ANOTHER CHANCE OF SHOWERS. DRY AND WARMER THURSDAY
ONWARD.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING 11 AM MST THIS MORNING TO 1 AM MST TUESDAY
ABOVE 6500 FEET FOR AZZ510-511.
WINTER WEATHER ADVISORY 11 AM MST THIS MORNING TO 1 AM MST
TUESDAY ABOVE 6500 FEET FOR AZZ514.
WIND ADVISORY UNTIL 8 PM MST THIS EVENING ABOVE 5000 FEET FOR
AZZ512>515.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS RENO NV
306 PM PST MON MAR 2 2015
.SYNOPSIS...
A TROUGH ACROSS THE REGION WILL INCREASE CLOUD COVER AND PROVIDE
CHANCES FOR SNOW SHOWERS ESPECIALLY ALONG THE SIERRA INTO
TOMORROW. AREAS OF SNOW SHOWERS WITH LIGHT SNOW ACCUMULATIONS
ARE POSSIBLE ACROSS EASTERN PERSHING AND CHURCHILL COUNTIES INTO
TUESDAY MORNING AS WELL. DRY NORTHERLY FLOW WILL DEVELOP TUESDAY
AND WEDNESDAY FOLLOWED BY A WARMING TREND FOR THE END OF THE WEEK.
&&
.SHORT TERM...
ISOLATED SNOW SHOWERS HAVE FORMED ACROSS THE SIERRA THIS AFTERNOON
AND WILL CONTINUE TO DEVELOP THROUGH THE EVENING. AN ADDITIONAL
COUPLE OF INCHES OF SNOW ARE POSSIBLE IN THE HIGHER TERRAIN WITH
TRACE AMOUNTS FOR WESTERN NEVADA. THE SHOWERS WILL BE CONVECTIVE,
SIMILAR TO THIS PAST WEEKEND, BUT NOT NEARLY AS PERSISTENT.
HOWEVER, IF A STRONG STORM DEVELOPS THEN LOCALIZED HIGHER AMOUNTS
OF SNOW MAY RESULT.
A MORE DISTINCT SHORTWAVE ASSOCIATED WITH THE NORTHWARD PORTION OF
THE TROUGH WILL DROP ACROSS PERSHING AND CHURCHILL COUNTIES LATE
TONIGHT. MODELS DIFFER WITH THE TIMING OF THE SHORTWAVE AS THE NAM
SWINGS IT THROUGH THE INTERSTATE 80 CORRIDOR FROM RENO EASTWARD
DURING THE 12-15Z TIMEFRAME, WHILE THE GFS IS A COUPLE OF HOURS
EARLIER. THE HRRR SHOWS THE BAND STRENGTHENING SOUTH OF INTERSTATE 80
AROUND 12Z, AND DROPPING QUICKLY SOUTH WHICH WILL HELP TO LIMIT
SNOW AMOUNTS. ALTHOUGH SNOW ACCUMULATIONS SHOULD REMAIN AROUND AN
INCH, LOCALLY HEAVIER AMOUNTS WILL BE POSSIBLE UNDER MORE WELL
DEVELOPED SHOWERS THROUGH EARLY TUESDAY MORNING. SOME ENHANCEMENT
NEAR AREA LAKES WILL BE POSSIBLE SINCE TEMPERATURE DIFFERENTIALS
BETWEEN LAKE SURFACES AND THE LOWER TROPOSPHERE ARE GREATER THAN
5C. FOG MAY DEVELOP IN AREAS NORTH OF INTERSTATE 80 IF THE HIGH
CLOUDS CLEAR OUT QUICKLY ENOUGH, BUT THE EXTENT OF THE FOG WILL BE
LOCALIZED AND LIKELY AFFECT THE TYPICAL LOCATIONS, SUCH AS THE
MARTIS AND SIERRA VALLEYS. OTHERWISE, HIGH LEVEL CLOUDS LEFTOVER
FROM THE SHORTWAVE WILL LIMIT RADIATIONAL COOLING RESULTING IN
DECREASED CHANCES FOR FOG DEVELOPMENT TUESDAY MORNING.
VERY DRY MID-LEVEL AIR WILL WORK ITS WAY INTO THE SIERRA AND WESTERN
NEVADA TUESDAY/WEDNESDAY AHEAD OF THE UPPER LEVEL RIDGE, WHICH WILL
BRING AN END TO CHANCES FOR PRECIPITATION THROUGH THE REMAINDER OF
THE WEEK. A WARMING TREND WILL START MIDWEEK WITH TEMPERATURES
CLIMBING INTO THE HIGH 60S FOR WESTERN NEVADA AND THE MID 50S FOR
THE SIERRA BY FRIDAY. WEISHAHN
.LONG TERM...THURSDAY THROUGH MONDAY...
BY THURSDAY THE UPPER RIDGE RE-ESTABLISHES ITSELF OVER THE SOUTHWEST
AND REMAINS OVER THE AREA THROUGH THE WEEKEND. THIS WILL BRING
MOSTLY CLEAR SKIES, LIGHT WINDS, AND WELL ABOVE AVERAGE
TEMPERATURES TO THE REGION FOR THE WEEKEND.
DAYTIME TEMPERATURES WILL RISE 10 TO 12 DEGREES ABOVE NORMAL WITH
SIERRA VALLEYS EASILY REACHING THE UPPER 50`S AND POSSIBLY LOW
60`S DURING THE DAY. WESTERN NEVADA WILL SEE TEMPERATURES RISE
BACK TO THE MID TO UPPER 60`S THROUGH THE WEEKEND. CLEAR SKIES AND
INCREASED SNOW COVER WILL ALLOW TEMPERATURES TO REMAIN COOL OVERNIGHT,
WITH NEAR FREEZING TEMPERATURES IN WESTERN NEVADA AND LOW 20`S FOR
SIERRA VALLEYS.
BY THE END OF THE WEEKEND MODELS ARE IN GOOD AGREEMENT WITH THE MEAN
RIDGE AMPLIFYING OVER THE EASTERN PACIFIC AND ALLOWING A LARGE CLOSED
LOW TO DEVELOP UNDER IT AROUND 150W. THIS COULD STRENGTHEN THE
SUBTROPICAL JET WHILE A POSITIVE RIDGE ANOMALY BUILDS SOUTHWEST OF
THE ALEUTIAN ISLANDS DURING THE NEXT WEEK. MODELS ARE INDICATING A
TROUGH DEVELOPING ALONG THE WEST COAST NEXT WEEK. OF COURSE,
SIGNIFICANT MODEL INCONSISTENCIES REMAIN ABOUT JUST HOW DEEP THE
TROUGH WILL BE AND ESPECIALLY HOW FAR SOUTH COLD AIR WILL BE
ENTRAINED. TOLBY
&&
.AVIATION...
SCATTERED CONVECTIVE SHOWERS REMAIN THROUGHOUT THE REGION WITH THE
STRONGEST SHOWERS WEST OF THE SIERRA CREST. CONTINUED SHOWERS
REMAIN POSSIBLE AT ALL TERMINALS THROUGH 06Z WITH BRIEF PERIODS OF
MFVR CONDITIONS POSSIBLE MAINLY AT KTVL/KTRK. SURFACE WINDS WILL
REMAIN ERRATIC NEAR CONVECTIVE SHOWERS WITH GUSTS OF 20KTS
POSSIBLE. CURRENT HRRR SHOWS A SECOND WAVE OF CONVECTIVE SHOWERS
MOVING THROUGH NW NEVADA POTENTIALLY IMPACTING KNFL AROUND 10Z.
MODERATE MID-LEVEL CLOUDS EXPECTED THROUGH MONDAY NIGHT, HOWEVER ANY
POSSIBLE CLEARING WOULD ALLOW FOG TO DEVELOP IN SIERRA VALLEYS.
LIGHT NORTH SURFACE WINDS WITH VFR CONDITIONS FOR TUESDAY. TOLBY
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1039 AM PST Mon Mar 2 2015
.Synopsis...
Another wave drops down from the north today bringing scattered
showers, mainly for the northern Sierra Nevada, and a slight
chance of thunderstorms. The mountains may see some light snowfall
accumulation. Drier and milder weather returns Tuesday and
continues through the remainder of the week.
&&
.Discussion...
Scattered showers continue this morning with the best coverage
over the Sierra. Main forecast challenge today will be snow amounts
with convective bands over the Sierra. Snow levels are currently
around 5000 feet and expect snow amounts 2-4 inches above this
level with locally higher amounts with stronger convection.
Strengthening March sun will help melt snow off roadways between
bands. Updated forecast to raise Sierra precip amounts/chances
more in line with HRRR which will likely handle this convective
scenario better. Will maintain isolated thunderstorm threat over
the valley given 250 j/g of cape forecast by NAM Buf sounding.
.Previous Discussion...
Satellite imagery shows the next wave dropping quickly southward
off the coast of Oregon and northwest California. Lots of
cloudiness has overspread NorCal overnight and even a few showers
are beginning to develop across the far southern portion of the
forecast area from far eastern Stanislaus County into Tuolumne
County. Temperatures are a little milder early this morning across
much of the region, though Redding and Red Bluff are running 10
degrees cooler compared to 24 hours ago due to the lack of north
winds compared to yesterday.
Most of the energy with this next wave is expected to remain
offshore or right along the coast, but there will be enough for
scattered showers inland across NorCal today along with enough
instability forecast this afternoon for a slight chance for a few
thunderstorms over the southern portion of the forecast area
(generally Sacramento area southward in the valley).
While available moisture for this system will be quite meager,
satellite imagery is showing TPW of around 1/2 inch being drawn
back north ahead of this next wave, so there will be potential for
a tenth or two of QPF in the northern Sierra along with an inch or
two of snowfall accumulation over the higher elevations.
Snow levels expected to start out around 3500-4500 feet this
morning then rise slightly by this afternoon.
High pressure begins to rebuild over the area later tonight and
Tuesday with a return of generally light north to east winds
bringing a drying and moderating airmass. Another even weaker
wave is forecast to drop southward Wednesday slowing the warming
trend, but even milder weather is expected behind this feature for
the second half of the week.
&&
.Extended Discussion (Friday through Monday)
No significant weather impacts through next Monday as high pressure
ridge builds and remains in control over the West Coast. A mostly
clear sky resulting in more dry weather will rule with above
normal temperatures and light winds. Daytime highs are expected
in the 60s to 70s within the valley and 50s to 60s over the
mountains through Monday. Patchy morning fog may form in northern
San Joaquin Valley and southern Sac Valley. Models show a minimal
threat of precipitation next Tuesday, then increasing the
potential mid to late next week. JClapp
&&
.Aviation...
Mainly VFR conditions across the Valley the next 24 hours, with
scattered -SHRA possible during the day. For the mountains,
widespread IFR/LIFR conditions will continue through this evening.
Snow levels will be around 4000 ft. Across the Valley...south
winds 5-15 kt will become light tonight.
Dang
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBANY NY
1234 PM EST MON MAR 2 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION LATE TODAY INTO EARLY
TUESDAY...BEFORE ANOTHER STORM SYSTEM APPROACHES FROM THE WEST.
THIS SYSTEM IS EXPECTED TO BRING MORE UNSETTLED WEATHER LATE
TUESDAY INTO WEDNESDAY...INCLUDING THE POTENTIAL FOR A WINTRY MIX
OF PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1215 PM EST...THE DEPARTING UPPER LEVEL SHORTWAVE IS TAKING
SOME MOISTURE OFF LAKE ONTARIO TO CAUSE SOME ADDITIONAL SNOW
SHOWERS. THESE ARE BEING ENHANCED BY THE UPSLOPE FLOW INTO THE
HIGH TERRAIN AS WELL. AS A RESULT...A FEW ADDITIONAL SNOW SHOWERS
WILL CONTINUE INTO THIS AFTERNOON...WITH A FRESH COATING OF SNOW
POSSIBLE IN HIGH TERRAIN AREAS. MOST VALLEY AREAS WILL BE DRY WITH
A MIX OF SUN AND CLOUDS AND A PASSING FLURRY IN SPOTS.
MOST OF THE SNOW SHOWERS WILL BE DONE BY THE AFTN...ALTHOUGH THE
LATEST 3KM HRRR SUGGESTS THAT THE SRN ADIRONDACKS AND SRN GREEN
MOUNTAINS COULD SEE AN INSTABILITY-FORCED SNOW SHOWER THIS AFTN IN
SPOTS THANKS TO STRENGTHENING COLD AIR ADVECTION IN PLACE.
WITH THIS STRONG CAA ONGOING...WINDS BECOME STRONG AND GUSTY FROM
THE NORTHWEST. CLOUDS WILL BE SLOW TO ERODE THROUGH THE DAY BUT
THE WINDS SHOULD HELP MIXING...AND HIGHS TODAY ARE EXPECTED TO
REACH THE 30S IN MANY AREAS...WITH 20S IN HIGHER ELEVATIONS. WINDS
COULD GUSTS OVER 30 MPH...ESP FOR THE CAPITAL REGION...BERKSHIRES...AND
OTHER HIGH TERRAIN AREAS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
STRONG GUSTY WINDS WILL GRADUALLY DIMINISH THROUGH THE NIGHT...AND
TREND TO CALM BY DAYBREAK. THE SKY IS EXPECTED TO CLEAR IN MOST
AREAS THROUGH THE NIGHT AS WELL AS RELATIVELY STRONG LOW LEVEL
RIDGING BUILDS IN. THE LIGHT WINDS AND CLEAR SKY SHOULD SUPPORT
LOWS IN THE SINGLE NUMBERS BUT BELOW ZERO IN NORTHERN AREAS.
THE NEXT SYSTEM APPROACHES THROUGH THE DAY TUESDAY WITH
INCREASING AND THICKENING CLOUDS THROUGH THE DAY. BY LATE
AFTERNOON...LIGHT SNOW SHOULD SPREAD ACROSS THE REGION WITH SOME
LIGHT ACCUMULATIONS POSSIBLE THROUGH THROUGH THE AFTERNOON/EVENING
COMMUTE. HIGHS TUESDAY IN THE 20S TO NEAR 30.
PRECIPITATION BECOMES MORE STEADY TUESDAY NIGHT AS A WARM LAYER
ALOFT TRACKS RAPIDLY THROUGH THE REGION. SO...AFTER ABOUT 1-4
INCHES OF SNOW ACROSS THE REGION...PRECIPITATION IS EXPECTED TO
TRANSITION THROUGH A PERIOD OF SLEET AND FREEZING RAIN...
ESPECIALLY ALONG AND SOUTH OF THE MOHAWK VALLEY TO SOUTHERN
VERMONT. PRECIPITATION MAY REMAIN MAINLY SNOW AND SLEET IN THE
SOUTHERN ADIRONDACKS...LAKE GEORGE AND NORTHERN SARATOGA REGION.
ICE ACCUMULATIONS SHOULD BE A TENTH OF AN INCH OR LESS...AND IN
SOME CASES JUST A TRACE...BUT SOME AREAS WHERE SOME ENHANCEMENT
OCCURS MAYBE JUST OVER A TENTH OF AN INCH. THERE IS STILL A LOT OF
UNCERTAINTY AS TO WHAT AREAS HAVE THE BEST CHANCES FOR 4 OR MORE
INCHES OF SNOW AND HOW FAR NORTH ANY FREEZING RAIN CAN GET. SO...
NO WINTER WEATHER ADVISORIES YET...BUT MORE DETAILS WILL BECOME
CLEARER LATER TODAY AND TONIGHT...AND SOME HEADLINES ARE LIKELY AS
THIS EVENT DRAWS NEARER. TEMPERATURES MAY DROP A DEGREE OR TWO
TUESDAY NIGHT...THEN RISE A FEW DEGREES TOWARD DAYBREAK.
STEADY PRECIPITATION IS EXPECTED TO END QUICKLY WEDNESDAY MORNING
AS THE BOUNDARY LAYER THERMAL GRADIENT TRACKS EAST AND SOUTH OF
THE REGION. KEEPING SCATTERED RAIN AND SNOW SHOWERS AS THE LOW
LEVEL COLD FRONT TRACKS THROUGH AND SOME LAKE EFFECT CLOUDINESS
AND SNOW SHOWER ACTIVITY COULD BEGIN TO DEVELOP. WEST TO
NORTHWEST WINDS SHOULD HELP MIXING AND TEMPERATURES SHOULD REACH
THE MID TO UPPER UPPER 30S IN NORTHERN AREAS TO LOWER TO MID 40S
IN SOUTHERN AREAS...DEPENDING ON WHETHER VERY COLD FROZEN GROUND
LIMITS SURFACE WARMING.
A TRAILING PIECE OF UPPER ENERGY TRACKS OFF THE MID ATLANTIC
COAST WEDNESDAY NIGHT...WITH INCREASING FRONTOGENESIS AND FORCING
ALONG AND JUST NORTH OF THE BOUNDARY LAYER THERMAL GRADIENT. THE
NORTHERN PERIPHERY OF THE PRECIPITATION SHIELD COULD EXTEND
THROUGH THE EASTERN CATSKILLS...MID HUDSON VALLEY AND NW CT. LOTS
OF SPREAD IN GUIDANCE FOR THIS POTENTIAL TRAILING SYSTEM. SO
PUTTING HIGH CHANCES FOR SNOW IN SOUTHERN AREAS...AND GENERAL
CHANCES FOR SNOW IN CENTRAL AND NORTHERN AREAS...AS THERE IS A
SMALL CHANCE THAT THIS SYSTEM COULD TRACK FAR ENOUGH NORTH TO GIVE
SOME LIGHT SNOW ACCUMULATIONS A BIT MORE NORTH...BUT AGAIN...
THERE IS LOTS OF UNCERTAINTY AND DETAILS FOR WEDNESDAY NIGHT WILL
GET CLEARER LATER TODAY AND TOMORROW.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THE PERIODS STARTS OUT THURSDAY MORNING WITH A SLOW MOVING FRONTAL
BOUNDARY DRAPED ACROSS THE MID ATLANTIC REGION. A WAVE ALONG THE
FRONT COULD POTENTIALLY SPREAD SOME SNOWFALL ACROSS AT LEAST THE
SOUTHERN HALF OF THE AREA. GFS/ECMWF/GGEM HAVE TRENDED SLIGHTLY
NORTHWARD WITH QPF SO WILL MENTION CHANCE POPS FOR NOW. ALSO PLUME
DIAGRAM FOR ALB FROM THE GFS ENSEMBLES SHOW SEVERAL MEMBERS WITH
AROUND 0.25 INCH QPF AMOUNTS...SO THERE IS UNCERTAINTY.
DETERMINISTIC QPF LOOKS RELATIVELY LIGHT AT THIS TIME...BUT HEAVIER
PRECIP IS FORECAST ACROSS THE MID ATLANTIC REGION. IF THE UPSTREAM
UPPER LEVEL TROUGH BECOMES DEEPER THAN WHAT IS CURRENTLY
FORECAST...THE FRONT/WAVE COULD SPREAD FARTHER NORTH INTO OUR AREA.
WILL HAVE TO WATCH THIS CLOSELY.
BY LATE THURSDAY THIS SYSTEM SHOULD BE EXITING THE EASTERN
SEABOARD...AS THE UPPER TROUGH PUSHES EASTWARD ACROSS THE GREAT
LAKES AND INTO THE NORTHEAST CONUS. A SURFACE RIDGE OF HIGH PRESSURE
LOOKS TO QUICKLY BUILD IN THURSDAY NIGHT...WHICH WILL RESULT IN VERY
COLD TEMPERATURES IN THE SINGLE DIGITS TO BELOW ZERO.
MAINLY DRY WEATHER IS THEN EXPECTED FOR FRIDAY THROUGH SUNDAY...WITH
A GRADUAL MODERATING TREND AS A W-SW FLOW REGIME SETS UP. THERE
COULD BE A FEW SNOW SHOWERS ACROSS THE WESTERN ADIRONDACKS SATURDAY
INTO EARLY SUNDAY...AS A WEAK DISTURBANCE APPROACHES. AFTER A COLD
DAY FRIDAY...TEMPERATURES MAY ACTUALLY WARM TO NEAR NORMAL FOR
SATURDAY INTO SUNDAY AS BOTH THE GFS AND ECMWF ARE INDICATING.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
WITH AN UPPER LEVEL SHORTWAVE TROUGH MOVING OVER THE
REGION...THERE MAY BE A FEW MORE SNOW SHOWERS AND FLURRIES AROUND.
MOST OF THESE WILL BE LOCATED OVER HIGH TERRAIN AREAS...SO EXPECT
LITTLE TO NO IMPACT FOR VSBYS/CIGS AT THE VALLEY TERMINALS...WITH
PERHAPS A BRIEF PERIOD OF MVFR VSBYS POSSIBLE AT KPSF OVER THE
NEXT FEW HOURS.
OTHERWISE...BKN-OVC CIGS OF 3500-5000 FT WILL BE IN PLACE THROUGH
THE EARLY EVENING HOURS WITH VFR CONDITIONS. NW WINDS OF 10-20
KTS WILL GUSTS 20-30 KTS AT TIMES...ESP FOR KALB/KPSF. WINDS WILL
START TO DIMINISH THIS EVENING WITH THE LOSS OF DAYTIME
HEATING/MIXING.
OVERNIGHT...HIGH PRESSURE WILL BUILD INTO THE AREA. THIS WILL
ALLOW WINDS TO DIMINISH AND BECOME NEARLY CALM TOWARDS MIDNIGHT -
2AM. ALSO...SKIES WILL BECOME NEARLY CLEAR AS WELL FOR ALL SITES.
SOME MID/HIGH LEVEL CLOUDS WILL INCREASE ON TUESDAY MORNING...AS
ANOTHER STORM SYSTEM RAPIDLY APPROACHES THE AREA. SKIES WILL
BECOME BKN-OVC BY EARLY TUESDAY AFTERNOON...WITH PRECIP ARRIVING
LATER IN THE DAY IN THE FORM OF SNOW.
OUTLOOK...
TUE PM: MODERATE OPERATIONAL IMPACT. LIKELY SN IN THE LATE AFTERNOON.
TUE NT-WED: HIGH OPERATIONAL IMPACT. SN/PL/FZRA.
WED NT- THU: LOW OPERATIONAL IMPACT. CHC -SHRA.
FRI-SAT: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 5 DAYS. DRY
WEATHER IS EXPECTED THIS AFTERNOON THROUGH TUESDAY MORNING.
HOWEVER...ANOTHER STORM SYSTEM WILL IMPACT THE REGION LATE TUESDAY
INTO WEDNESDAY...WITH THE POSSIBILITY OF SNOW...MIXED
PRECIPITATION AND/OR RAIN.
TEMPERATURES MAY BRIEFLY RISE ABOVE FREEZING DURING THE DAY TODAY...
BEFORE ANOTHER COLD AIR MASS SETTLES IN FOR TONIGHT INTO TUESDAY.
WITH THE CONTINUED COLD CONDITIONS IN PLACE...ICE WILL CONTINUE TO
STRENGTHEN AND THICKEN ON AREA RIVERS...STREAMS...CREEKS...LAKES...
AND PONDS.
A BRIEF WARMUP MAY OCCUR ON WEDNESDAY...BUT THE SHORT TIMING AND
MAGNITUDE OF THE WARMTH WILL LIKELY NOT BE ENOUGH TO CAUSE ANY HYDRO
CONCERNS. ANOTHER COLD AIR MASS WILL BUILD IN LATE WEDNESDAY INTO
THURSDAY...WITH TEMPERATURES FALLING BACK BELOW FREEZING.
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...NAS
NEAR TERM...FRUGIS/11/NAS
SHORT TERM...NAS
LONG TERM...JPV
AVIATION...FRUGIS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1215 PM EST MON MAR 2 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION LATE TODAY INTO EARLY
TUESDAY...BEFORE ANOTHER STORM SYSTEM APPROACHES FROM THE WEST.
THIS SYSTEM IS EXPECTED TO BRING MORE UNSETTLED WEATHER LATE
TUESDAY INTO WEDNESDAY...INCLUDING THE POTENTIAL FOR A WINTRY MIX
OF PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1215 PM EST...THE DEPARTING UPPER LEVEL SHORTWAVE IS TAKING
SOME MOISTURE OFF LAKE ONTARIO TO CAUSE SOME ADDITIONAL SNOW
SHOWERS. THESE ARE BEING ENHANCED BY THE UPSLOPE FLOW INTO THE
HIGH TERRAIN AS WELL. AS A RESULT...A FEW ADDITIONAL SNOW SHOWERS
WILL CONTINUE INTO THIS AFTERNOON...WITH A FRESH COATING OF SNOW
POSSIBLE IN HIGH TERRAIN AREAS. MOST VALLEY AREAS WILL BE DRY WITH
A MIX OF SUN AND CLOUDS AND A PASSING FLURRY IN SPOTS.
MOST OF THE SNOW SHOWERS WILL BE DONE BY THE AFTN...ALTHOUGH THE
LATEST 3KM HRRR SUGGESTS THAT THE SRN ADIRONDACKS AND SRN GREEN
MOUNTAINS COULD SEE AN INSTABILITY-FORCED SNOW SHOWER THIS AFTN IN
SPOTS THANKS TO STRENGTHENING COLD AIR ADVECTION IN PLACE.
WITH THIS STRONG CAA ONGOING...WINDS BECOME STRONG AND GUSTY FROM
THE NORTHWEST. CLOUDS WILL BE SLOW TO ERODE THROUGH THE DAY BUT
THE WINDS SHOULD HELP MIXING...AND HIGHS TODAY ARE EXPECTED TO
REACH THE 30S IN MANY AREAS...WITH 20S IN HIGHER ELEVATIONS. WINDS
COULD GUSTS OVER 30 MPH...ESP FOR THE CAPITAL REGION...BERKSHIRES...AND
OTHER HIGH TERRAIN AREAS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
STRONG GUSTY WINDS WILL GRADUALLY DIMINISH THROUGH THE NIGHT...AND
TREND TO CALM BY DAYBREAK. THE SKY IS EXPECTED TO CLEAR IN MOST
AREAS THROUGH THE NIGHT AS WELL AS RELATIVELY STRONG LOW LEVEL
RIDGING BUILDS IN. THE LIGHT WINDS AND CLEAR SKY SHOULD SUPPORT
LOWS IN THE SINGLE NUMBERS BUT BELOW ZERO IN NORTHERN AREAS.
THE NEXT SYSTEM APPROACHES THROUGH THE DAY TUESDAY WITH
INCREASING AND THICKENING CLOUDS THROUGH THE DAY. BY LATE
AFTERNOON...LIGHT SNOW SHOULD SPREAD ACROSS THE REGION WITH SOME
LIGHT ACCUMULATIONS POSSIBLE THROUGH THROUGH THE AFTERNOON/EVENING
COMMUTE. HIGHS TUESDAY IN THE 20S TO NEAR 30.
PRECIPITATION BECOMES MORE STEADY TUESDAY NIGHT AS A WARM LAYER
ALOFT TRACKS RAPIDLY THROUGH THE REGION. SO...AFTER ABOUT 1-4
INCHES OF SNOW ACROSS THE REGION...PRECIPITATION IS EXPECTED TO
TRANSITION THROUGH A PERIOD OF SLEET AND FREEZING RAIN...
ESPECIALLY ALONG AND SOUTH OF THE MOHAWK VALLEY TO SOUTHERN
VERMONT. PRECIPITATION MAY REMAIN MAINLY SNOW AND SLEET IN THE
SOUTHERN ADIRONDACKS...LAKE GEORGE AND NORTHERN SARATOGA REGION.
ICE ACCUMULATIONS SHOULD BE A TENTH OF AN INCH OR LESS...AND IN
SOME CASES JUST A TRACE...BUT SOME AREAS WHERE SOME ENHANCEMENT
OCCURS MAYBE JUST OVER A TENTH OF AN INCH. THERE IS STILL A LOT OF
UNCERTAINTY AS TO WHAT AREAS HAVE THE BEST CHANCES FOR 4 OR MORE
INCHES OF SNOW AND HOW FAR NORTH ANY FREEZING RAIN CAN GET. SO...
NO WINTER WEATHER ADVISORIES YET...BUT MORE DETAILS WILL BECOME
CLEARER LATER TODAY AND TONIGHT...AND SOME HEADLINES ARE LIKELY AS
THIS EVENT DRAWS NEARER. TEMPERATURES MAY DROP A DEGREE OR TWO
TUESDAY NIGHT...THEN RISE A FEW DEGREES TOWARD DAYBREAK.
STEADY PRECIPITATION IS EXPECTED TO END QUICKLY WEDNESDAY MORNING
AS THE BOUNDARY LAYER THERMAL GRADIENT TRACKS EAST AND SOUTH OF
THE REGION. KEEPING SCATTERED RAIN AND SNOW SHOWERS AS THE LOW
LEVEL COLD FRONT TRACKS THROUGH AND SOME LAKE EFFECT CLOUDINESS
AND SNOW SHOWER ACTIVITY COULD BEGIN TO DEVELOP. WEST TO
NORTHWEST WINDS SHOULD HELP MIXING AND TEMPERATURES SHOULD REACH
THE MID TO UPPER UPPER 30S IN NORTHERN AREAS TO LOWER TO MID 40S
IN SOUTHERN AREAS...DEPENDING ON WHETHER VERY COLD FROZEN GROUND
LIMITS SURFACE WARMING.
A TRAILING PIECE OF UPPER ENERGY TRACKS OFF THE MID ATLANTIC
COAST WEDNESDAY NIGHT...WITH INCREASING FRONTOGENESIS AND FORCING
ALONG AND JUST NORTH OF THE BOUNDARY LAYER THERMAL GRADIENT. THE
NORTHERN PERIPHERY OF THE PRECIPITATION SHIELD COULD EXTEND
THROUGH THE EASTERN CATSKILLS...MID HUDSON VALLEY AND NW CT. LOTS
OF SPREAD IN GUIDANCE FOR THIS POTENTIAL TRAILING SYSTEM. SO
PUTTING HIGH CHANCES FOR SNOW IN SOUTHERN AREAS...AND GENERAL
CHANCES FOR SNOW IN CENTRAL AND NORTHERN AREAS...AS THERE IS A
SMALL CHANCE THAT THIS SYSTEM COULD TRACK FAR ENOUGH NORTH TO GIVE
SOME LIGHT SNOW ACCUMULATIONS A BIT MORE NORTH...BUT AGAIN...
THERE IS LOTS OF UNCERTAINTY AND DETAILS FOR WEDNESDAY NIGHT WILL
GET CLEARER LATER TODAY AND TOMORROW.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THE PERIODS STARTS OUT THURSDAY MORNING WITH A SLOW MOVING FRONTAL
BOUNDARY DRAPED ACROSS THE MID ATLANTIC REGION. A WAVE ALONG THE
FRONT COULD POTENTIALLY SPREAD SOME SNOWFALL ACROSS AT LEAST THE
SOUTHERN HALF OF THE AREA. GFS/ECMWF/GGEM HAVE TRENDED SLIGHTLY
NORTHWARD WITH QPF SO WILL MENTION CHANCE POPS FOR NOW. ALSO PLUME
DIAGRAM FOR ALB FROM THE GFS ENSEMBLES SHOW SEVERAL MEMBERS WITH
AROUND 0.25 INCH QPF AMOUNTS...SO THERE IS UNCERTAINTY.
DETERMINISTIC QPF LOOKS RELATIVELY LIGHT AT THIS TIME...BUT HEAVIER
PRECIP IS FORECAST ACROSS THE MID ATLANTIC REGION. IF THE UPSTREAM
UPPER LEVEL TROUGH BECOMES DEEPER THAN WHAT IS CURRENTLY
FORECAST...THE FRONT/WAVE COULD SPREAD FARTHER NORTH INTO OUR AREA.
WILL HAVE TO WATCH THIS CLOSELY.
BY LATE THURSDAY THIS SYSTEM SHOULD BE EXITING THE EASTERN
SEABOARD...AS THE UPPER TROUGH PUSHES EASTWARD ACROSS THE GREAT
LAKES AND INTO THE NORTHEAST CONUS. A SURFACE RIDGE OF HIGH PRESSURE
LOOKS TO QUICKLY BUILD IN THURSDAY NIGHT...WHICH WILL RESULT IN VERY
COLD TEMPERATURES IN THE SINGLE DIGITS TO BELOW ZERO.
MAINLY DRY WEATHER IS THEN EXPECTED FOR FRIDAY THROUGH SUNDAY...WITH
A GRADUAL MODERATING TREND AS A W-SW FLOW REGIME SETS UP. THERE
COULD BE A FEW SNOW SHOWERS ACROSS THE WESTERN ADIRONDACKS SATURDAY
INTO EARLY SUNDAY...AS A WEAK DISTURBANCE APPROACHES. AFTER A COLD
DAY FRIDAY...TEMPERATURES MAY ACTUALLY WARM TO NEAR NORMAL FOR
SATURDAY INTO SUNDAY AS BOTH THE GFS AND ECMWF ARE INDICATING.
&&
.AVIATION /17Z MONDAY THROUGH FRIDAY/...
CYCLONIC NW FLOW REGIME WILL RESULT IN PLENTY OF CLOUDS AND GUSTY
WINDS TODAY. CONDITIONS WILL GENERALLY BE VFR...ALTHOUGH A PERIOD
OF MVFR WILL BE POSSIBLE FOR A SHORT TIME THIS MORNING ESPECIALLY
AT KALB/KPSF WHERE SCT -SHSN WILL OCCUR. SKIES WILL CLEAR TONIGHT
AS HIGH PRESSURE BUILDS IN FROM THE WEST.
WINDS WILL BECOME W-NW AND STEADILY INCREASE TO BETWEEN 12-18 KTS
THIS MORNING WITH GUSTS OF 25 TO 30 KTS COMMON BY THIS AFTERNOON.
STRONGEST WINDS WILL BE AT KALB/KPSF. WIND SPEEDS WILL DECREASE
THIS EVENING AND ESPECIALLY OVERNIGHT AS HIGH PRESSURE APPROACHES.
OUTLOOK...
TUE: MODERATE OPERATIONAL IMPACT. LIKELY SN IN THE AFTERNOON.
TUE NT-WED: MODERATE OPERATIONAL IMPACT. SN/MIXED PCPN TO RAIN.
WED NT-THU: MODERATE OPERATIONAL IMPACT. CHC SN.
FRI: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 5 DAYS. DRY
WEATHER IS EXPECTED THIS AFTERNOON THROUGH TUESDAY MORNING.
HOWEVER...ANOTHER STORM SYSTEM WILL IMPACT THE REGION LATE TUESDAY
INTO WEDNESDAY...WITH THE POSSIBILITY OF SNOW...MIXED
PRECIPITATION AND/OR RAIN.
TEMPERATURES MAY BRIEFLY RISE ABOVE FREEZING DURING THE DAY TODAY...
BEFORE ANOTHER COLD AIR MASS SETTLES IN FOR TONIGHT INTO TUESDAY.
WITH THE CONTINUED COLD CONDITIONS IN PLACE...ICE WILL CONTINUE TO
STRENGTHEN AND THICKEN ON AREA RIVERS...STREAMS...CREEKS...LAKES...
AND PONDS.
A BRIEF WARMUP MAY OCCUR ON WEDNESDAY...BUT THE SHORT TIMING AND
MAGNITUDE OF THE WARMTH WILL LIKELY NOT BE ENOUGH TO CAUSE ANY HYDRO
CONCERNS. ANOTHER COLD AIR MASS WILL BUILD IN LATE WEDNESDAY INTO
THURSDAY...WITH TEMPERATURES FALLING BACK BELOW FREEZING.
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...NAS
NEAR TERM...FRUGIS/11/NAS
SHORT TERM...NAS
LONG TERM...JPV
AVIATION...JPV
HYDROLOGY...NAS
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1236 PM EST MON MAR 2 2015
.PREV DISCUSSION... /ISSUED 922 AM EST MON MAR 2 2015/
UPDATE...
HAVE MADE SOME MINOR CHANGES TO GRIDS TO UPDATE BASED ON
TRENDS...AND REDUCED POPS ACROSS EXTREME NORTH FOR THE MORNING
HOURS. HAVE SENT A REFRESH TO THE PRODUCTS ALREADY FOR THE
EXPIRATION OF THE DENSE FOG ADVISORY.
TDP
PREV DISCUSSION... /ISSUED 637 AM EST MON MAR 2 2015/
PREV DISCUSSION... /ISSUED 411 AM EST MON MAR 2 2015/
UPDATE...
NEW OBS HAVE COME IN AND ARE INDICATING THE PATCHY DENSE FOG IS
BECOMING MORE WIDESPREAD. GOING TO ISSUE A DENSE FOG ADVISORY.
PREV DISCUSSION... /ISSUED 344 AM EST MON MAR 2 2015/
SHORT TERM /TODAY THROUGH TUESDAY/...
A COLD FRONT CURRENTLY STRETCHES FROM CENTRAL NEW YORK STATE BACK TO
SOUTHWEST LOUISIANA THIS MORNING. THERE IS SOME SPOTTY PRECIPITATION
ASSOCIATED WITH THE BOUNDARY...CURRENTLY MOVING ACROSS CENTRAL
ALABAMA. THE TREND FOR THE LAST FEW HOURS IS FOR THE PRECIP TO
DWINDLE AS IT MOVES ACROSS THE CWFA. THE HRRR MODEL SUPPORTS THIS
CONTINUING TREND.
WEAK WEDGE WILL CONTINUE TO ERODE AWAY THIS MORNING AS THE COLD
FRONT APPROACHES THE CWFA. EXPECT THE LOW CLOUDS AND FOG TO LIFT A
BIT AFTER SUNRISE...BUT SKIES WILL REMAIN CLOUDY. ANTICIPATE THAT
THE FRONT WILL MOVE ACROSS NORTHERN GEORGIA...AND POSSIBLY MAKE IT
AS FAR SOUTH AS THE ATLANTA METRO BY EARLY AFTERNOON. NOT CONFIDENT
ON EXACTLY WHERE THE FRONT WILL STALL...BUT IT SHOULD BE SOMEWHERE
IN THE VICINITY OF THE INTERSTATE 20 CORRIDOR. TEMPERATURES ON THE
SOUTH SIDE OF THE BOUNDARY WILL BE MUCH WARMER AND HAVE THE
POTENTIAL TO REACH THE MIDDLE TO UPPER 60S IN THE SOUTHERLY
FLOW...NORTH OF THE BOUNDARY TEMPS WILL RANGE FROM THE MIDDLE 40S IN
THE HIGHER ELEVATIONS TO UPPER 50S NEAR CENTRAL GA. THE MAX TEMPS
TODAY WILL DEPEND HIGHLY UPON EXACTLY HOW FAR SOUTH THIS WEAK FRONT
WILL MAKE IT.
WEAK WEDGING WILL TRY AND SET UP IN THE NORTHEAST OVERNIGHT AND
TUESDAY AS HIGH PRESSURE SHIFTS OFFSHORE. THIS WILL CREATE A SHARP
MAX TEMP GRADIENT DURING THE DAY ON TUESDAY. AREAS SOUTH OF THE WEAK
FRONT COULD REACH ALL THE WAY INTO THE LOWER 70S...WHILE AREAS NORTH
OF THE FRONT...IN THE WEDGE...WILL REMAIN THE IN UPPER 40S TO NEAR
50. AGAIN...THE MAX TEMP FORECAST WILL HIGHLY DEPEND UPON WHERE THE
WEAK FRONT AND WEDGE SET UP. THE MORAL OF THE STORY IS...TODAY AND
TUESDAY WILL HAVE HIGH BUST POTENTIAL FOR MAX TEMPS.
AREAS OF FOG AND DRIZZLE SHOULD CONTINUE THROUGH MID MORNING.
VISIBILITIES BETWEEN ONE QUARTER AND ONE HALF OF A MILE ARE POSSIBLE
DURING THE MORNING COMMUTE. IF THE PATCHY DENSE FOG BECOMES MORE
WIDESPREAD...WILL HAVE TO CONSIDER ISSUING A DENSE FOG ADVISORY FOR
PORTIONS OF THE CWFA.
THE HRRR KEEPS MOST OF THE FORECAST AREA PRETTY DRY...WITH JUST
SPOTTY AREAS OF PRECIP TODAY. THE BEST PLACES FOR MEASURABLE
RAINFALL SHOULD BE ALONG THE AL/GA BORDER AND NORTH OF INTERSTATE 20
TODAY. PATCHY LIGHT RAIN AND DRIZZLE IS EXPECTED TO DEVELOP ONCE
AGAIN NORTH OF THE WEAK FRONT OVERNIGHT. BY TUESDAY...A LITTLE
INSTABILITY BEGINS TO DEVELOP ACROSS THE AREA. SOME SURFACE
INSTABILITY IS POSSIBLE SOUTH OF THE BOUNDARY...BUT THERE IS ALSO
SOME POTENTIAL FOR ELEVATED INSTABILITY NORTH OF THE BOUNDARY.
OVERALL...JUST THINK THE MENTION OF A SLIGHT CHANCE OF THUNDER
SHOULD SUFFICE.
NLISTEMAA
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MEDIUM RANGE MODELS REMAIN CONSISTENT AND IN RELATIVELY GOOD
AGREEMENT THROUGH THE MAJORITY OF THE EXTENDED FORECAST PERIOD.
STILL SHOWING THE WORK WEEK DOMINATED BY SOUTHWESTERLY UPPER FLOW
AHEAD OF THE DEEP WESTERN U.S. TROUGH. THIS KEEPS THE REGION IN A
FAIRLY WARM PATTERN UNTIL THURSDAY BEHIND THE SHARP SURFACE FRONT
THE SWEEPS THROUGH WEDNESDAY/WEDNESDAY NIGHT. STILL SEEING ENOUGH
INSTABILITY FOR CHANCE COVERAGE OF THUNDERSTORMS WEDNESDAY. STRONG
LOW/MID-LEVEL WINDS ALSO STILL HAVE ME A BIT CONCERNED ABOUT AT
LEAST ISOLATED SEVERE THUNDERSTORM POTENTIAL. GOOD LOW-LEVEL FORCING
AHEAD OF THE FRONT BUT UPPER SUPPORT IS LACKING WITH THE MAIN UPPER
TROUGH/SHORT WAVE LAGGING FAR BEHIND THE FRONT. GFS AND ECMWF ALSO
STILL INSIST ON BRINGING IN MUCH COLDER AIR AS EARLY AS LATE
WEDNESDAY NIGHT WITH RESIDUAL MOISTURE AND THE INFLUENCE OF THE
UPPER SYSTEM SQUEEZING OUT SOME LOW QPF PRECIPITATION. UPPER FLOW
REMAINS SOUTHWESTERLY THROUGH THURSDAY AND LOWEST THICKNESSES REMAIN
WELL NORTH OF THE STATE. WILL NEED TO WATCH TRENDS FOR THE
POSSIBILITY OF SOME WINTRY MIX ACROSS THE NORTH. GFS AND ECMWF BOTH
SHOW A GOOD TEMPERATURE RECOVERY INTO THE WEEKEND AFTER A THE SHOT
OF COOL AIR THURSDAY THROUGH FRIDAY MORNING AS THE UPPER FLOW
REMAINS GENERALLY ZONAL OVER THE SOUTHEASTERN U.S. AND THE HEART OF
THE COLDEST AIR REMAINS WELL NORTH OF THE STATE. MAINLY DRY AS
WELL...HOWEVER BOTH MODELS SHOW SOME PRECIPITATION POSSIBLY SURGING
NORTH INTO CENTRAL GEORGIA SATURDAY AS SURFACE LOW PRESSURE SPINS UP
OFF THE GEORGIA/CAROLINA COAST. NOT REAL CONFIDENT WE WILL SEE
ANYTHING SIGNIFICANT WITH THIS BUT SLIGHT CHANCE OR LOW CHANCE POPS
MAY BE APPROPRIATE.
20
&&
.AVIATION...
18Z UPDATE...
VFR CIGS ENCROACHING FROM THE EAST FOR AHN/MCN AND METRO TAFS.
SHOULD SEE CONTINUED VFR FOR A WHILE AHN BUT MCN/METRO TAFS MAY BE
IN AND OUT FOR A WHILE. EXPECT ALL TO DROP TO MVFR LATER THIS
EVENING AND IFR AROUND 06Z OR SHORTLY THEREAFTER. COULD SEE LIFR
CONDITIONS BY SUNRISE ESPECIALLY FOR THE METRO TAFS WITH -RA.
WINDS NW 5-10KT INITIALLY SHIFTING TO NE WITH THE LOWER CIGS AT
06Z. WINDS SHOULD CONTINUE TO SWING AROUND TO E OR SE BY TUESDAY
MIDDAY.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON ALL ELEMENTS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 63 46 50 48 / 40 60 70 50
ATLANTA 58 49 60 55 / 40 60 60 40
BLAIRSVILLE 53 44 48 48 / 90 60 70 70
CARTERSVILLE 52 46 56 53 / 60 60 70 60
COLUMBUS 65 58 73 59 / 40 30 20 20
GAINESVILLE 59 45 48 46 / 40 60 70 60
MACON 66 56 69 57 / 20 40 40 20
ROME 49 45 57 54 / 80 60 60 60
PEACHTREE CITY 59 51 62 56 / 40 40 40 30
VIDALIA 69 57 69 60 / 20 30 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
445 PM CST MON MAR 2 2015
.SHORT TERM...
317 PM CST
THROUGH WEDNESDAY...
.SHORT TERM...THROUGH WEDNESDAY
AS MENTIONED IN THE EARLIER UPDATE... A WINTER WEATHER ADVISORY
WAS ISSUED FOR THE ENTIRE AREA EARLIER IN THE SHIFT FOR LATE
TONIGHT THROUGH TUESDAY MORNING. MODELS ARE STILL SHOWING
PRECIPITATION BEGINNING AS SNOW NORTH OF INTERSTATE 80...AND SOME
FORM OF SNOW...SLEET OR FREEZING RAIN IN THE FAR SOUTH. IT COULD
BE A PRETTY GOOD BURST OF WET SNOW INITIALLY BEFORE THE TRANSITION
BEGINS.
A WARM FRONT WILL LIFT THROUGH THE AREA DURING THE MORNING HOURS.
THIS IS THE PERIOD WHERE MODELS A SHOWING A MORE SIGNIFICANT PUSH
OF PRECIPITATION. WE ARE COMING OUT OF A PRETTY COLD AIR
MASS..AND DEWPOINTS ARE STILL VERY LOW ACROSS THE AREA...WITH
DEWPOINTS ABOVE FREEZING NOT VERY CLOSE. TEMPERATURES LOOK TO
REMAIN BELOW FREEZING THROUGH AT LEAST MID MORNING AREA WIDE.
MODEST PRECIPITABLE WATER VALUES IN EXCESS OF 0.75 INCHES COUPLED
WITH A 35-40 KT LOW LEVEL JET FEEDING INTO THE LOW LEVEL FRONTAL
ZONE WOULD SUGGEST MODEST PRECIPITATION RATES DURING THIS TIME WHEN
THE LOW LEVEL (925-850 MB) TEMPERATURES ARE HEADING ABOVE
FREEZING. SOME OF THE RECENT NAM/GFS WAS SLIGHTLY COOLER IN THE
THERMAL PROFILE FOR THIS PERIOD SUGGESTING THAT SNOW/SLEET MAY
DOMINATE...ESPECIALLY FOR THE NORTHERN METRO AREA AND POINTS NORTH
TOWARD WISCONSIN... AND IF PRECIPITATION RATES CONTINUE A BIT
HEAVIER THIS MAY SLOW THE LOW LEVEL WARMING. BUT THE SIGNAL IS
STILL THERE FOR A SNOW-SLEET-FZRA TRANSITION AND ICE ACCUMULATION
POTENTIAL.
WHERE THE UNCERTAINTIES REMAIN IS IN REGARDS TO HOW MUCH ICE
ACCUMULATION WILL OCCUR AND HOW FAR NORTH THE IMPACTS ARE FELT. ICE IS
EXPECTED TO BE THE LEAST NORTH TOWARDS WISCONSIN AND IN THE
ROCKFORD AREA WHERE IT MAY JUST BE AN ALL SNOW/SLEET SITUATION
WHERE ADVISORY CRITERIA MAY NOT BE TECHNICALLY SATISFIED. GIVEN
THE UNCERTAINTY AND THE RUSH-HOUR TIME...FEEL IT IS THE SAFER CALL
WITH SOME SNOW/SLEET AS WELL. AND IN NW INDIANA...THE BETTER
MOISTURE ADVECTION IS FOCUSED HERE WHERE THERE IS HIGHER POTENTIAL
FOR ICE ACCUMULATION...BUT IT WILL BE A RACE AGAINST SURFACE TEMPS
AS WELL WHICH LOOK TO WARM THROUGH THE MORNING. AS MENTIONED
EARLIER...MEANWHILE...THE ECMWF/GEM ARE MORE SUPPORTIVE OF A
SNOW/SLEET SOLUTION IN MANY AREAS...ESPECIALLY NORTH OF INTERSTATE
80. IT LOOKS LIKE THE TRANSITION TIME FOR MIXED PRECIPITATION
SOUTH OF I-80 WILL OCCUR BEFORE DAYBREAK BASED ON THE NAM AND
EARLY LOOKS AT THE RAP CLOSE TO THAT TIME FRAME. IT WOULD LIKELY
BE AFTER 6-7 AM WHEN THAT TRANSITION OCCURS IN THE METRO
AREA...BUT CONFIDENCE ON THAT TIMING IS NOT SUPER HIGH.
WHILE WE ARE LOSING THE DEEPER MOISTURE IN THE AFTERNOON...WE ARE
GETTING SOME DECENT MID LEVEL FRONTOGENESIS WHICH SHOULD STILL ALLOW
US TO WRING OUT SOME PRECIPITATION IN THE AFTERNOON WHICH COULD BE A
SNOW-RAIN MIX IN THE NW...LIKELY RAIN IN THE SE...WITH EVEN SOME
-SN/DZ/FZDZ POSSIBLE ACROSS THE CHICAGO METRO AREA LATE IN THE
AFTERNOON AND EVENING.
THE UPPER TROUGH AXIS WILL GRADUALLY MOVE THROUGH THE AREA WHILE
SURFACE HIGH PRESSURE NOSES IN FROM THE NORTHWEST. EXPECT COLDER
CONDITIONS WITH SOME HIGH CLOUDS MOVING THROUGH. HIGHS WILL BE IN
THE TEENS WEDNESDAY AND THURSDAY...WITH LOWS EARLY THURSDAY MORNING
BOTTOMING OUT AT OR BELOW ZERO. WITH THE HIGH STILL TO THE
EAST...WIND CHILLS...YES WE ARE STILL DISCUSSING WIND CHILLS IN
EARLY MARCH...GET DOWN TO -10 TO -20 BELOW. A CLIMATE SECTION TO
THE AFD WILL BE FORTHCOMING.
KMD
&&
.LONG TERM...
317 PM CST
THURSDAY THROUGH MONDAY...
THE EXTENDED PERIOD WILL START OUT VERY COLD AS A 1040 MB ARCTIC
HIGH SHIFTS ACROSS THE REGION. WITH 925 AND 850 MB TEMPERATURES
PROGGED TO BE AROUND -18 CELSIUS...THIS SHOULD ONLY ALLOW FOR HIGHS
IN THE MIDDLE TO UPPER TEENS...FOLLOWING A BITTERLY COLD AND
POTENTIALLY RECORD COLD MORNING. THE GOOD NEWS IS THAT THIS WILL BE
A PROGRESSIVE HIT OF ARCTIC AIR. IN FACT...TEMPERATURES SHOULD
QUICKLY RECOVER BY FRIDAY AS A GUSTY SOUTH-SOUTHWESTERLY FLOW SETS
UP ALONG THE NORTHWESTERN PERIPHERY OF THE EXITING SURFACE RIDGE OF
HIGH PRESSURE. THIS SHOULD SUPPORT HIGHS INTO THE LOW 30S
FRIDAY...AND POSSIBLY WELL INTO THE 30S FOR THE WEEKEND. A WEAK COLD
FRONT MAY DROP ACROSS THE AREA OVER THE WEEKEND...BUT IT APPEARS THE
DEEPER COLD WILL BE AIMED TO OUR NORTHEAST. PRECIPITATION CHANCES
ALSO APPEAR TO BE MINIMAL DURING MUCH OF THE EXTENDED PERIOD.
KJB
&&
.CLIMATE...
417 PM CST
A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN
JEOPARDY ON WEDNESDAY AND THURSDAY.
HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT
STAND THE BEST CHANCE TO BE REACHED ORBROKEN HAVE A STAR (*) NEXT TO
THEM.
WED 3/4 THU 3/5
ROCKFORD
RECORD LOW-11 (2002)-11 (2002)
RECORD LOW MAX 14 (2002)* 17 (1960)*
CHICAGO
RECORD LOW-12 (1873) 0 (1978)*
RECORD LOW MAX 17 (1890)* 12 (1901)
KMD/KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* LIGHT/VARIABLE WINDS THIS AFTERNOON BEFORE FLOPPING SOUTHEAST BY
EARLY EVENING. SOUTH-SOUTHEAST WINDS BECOMING GUSTY 20-25 KT BY
TUESDAY MORNING.
* SNOW...MIXING WITH SLEET THEN CHANGING TO FREEZING RAIN/RAIN
EARLY TUESDAY MORNING. VFR CONDITIONS TO QUICKLY DETERIORATE TO
IFR/LIFR IN PRECIP.
KJB
//DISCUSSION...UPDATED 18Z...
IT WILL CONTINUE TO BE A QUIET WEATHER DAY ACROSS THE AREA TODAY. A
SURFACE RIDGE OF HIGH PRESSURE PUSHING ACROSS THE AREA THIS
AFTERNOON WILL RESULT IN A PERIOD OF LIGHT AND VARIABLE
WINDS...THOUGH THE WINDS SHOULD SETTLE INTO A SOUTHEASTERLY DIRECTION
BY EARLY THIS EVENING. OTHERWISE VFR CONDITIONS EXPECTED.
THE WEATHER WILL BECOME MUCH MORE PROBLEMATIC BY DAYBREAK TUESDAY.
WINDS WILL INCREASE OUT OF THE SOUTHEAST AND BECOME GUSTY DURING THE
MORNING. SNOW WILL ALSO DEVELOP OVER THE AREA JUST PRIOR TO
DAYBREAK...BEFORE MIXING WITH SLEET AND CHANGING OVER TO A PERIOD OF
FREEZING RAIN BY MID MORNING TUESDAY. IT CURRENTLY APPEARS THAT
ABOUT A 1 TO 3 HOUR PERIOD OF SNOW AND SLEET WILL OCCUR FROM ROUGHLY
11 UTC THROUGH 13 TO 15 UTC. DURING THIS PERIOD IFR VIS IN SNOW AND
LOWERING CIGS ARE LIKELY. CIGS WILL CONTINUE TO DETERIORATE INTO THE
IFR AND LIFR CATEGORIES DURING THE MORNING AS WARMER AIR ALOFT
BEGINS TO CHANGE THE SNOW AND SLEET OVER TO SOME FREEZING RAIN.
SURFACE TEMPERATURES SHOULD ALSO BE ON A WARMING TREND DURING THE
MORNING...AND ARE EXPECTED TO WARM ABOVE FREEZING BY MIDDAY...SO ANY
LINGERING PRECIP AFTER THIS TIME WILL LIKELY NO LONGER PRODUCE A
FREEZING THREAT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM-HIGH IN PRECIP TIMING/TREND EARLY TUESDAY. MEDIUM IN
CIG/VIS IMPACTS.
* HIGH ALL OTHER ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...MVFR CIGS. GUSTY WEST WINDS.
WEDNESDAY...MVFR CIGS.
THURSDAY AND FRIDAY...VFR.
SATURDAY AND SUNDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
224 PM...HIGH PRESSURE OVER THE SOUTHERN LAKES AND OHIO VALLEY
WILL MOVE EAST TO THE MID ATLANTIC AND NEW ENGLAND TUESDAY MORNING
AS LOW PRESSURE FORMS OVER THE CENTRAL PLAINS TONIGHT. THIS LOW
WILL QUICKLY MOVE NORTHEAST TUESDAY AND BE ABSORBED BY STRONGER
LOW PRESSURE OVER NORTHERN ONTARIO...AS A COLD FRONT MOVES ACROSS
LAKE MICHIGAN. THE GRADIENT WILL SLOWLY INCREASE AHEAD OF THIS LOW
TONIGHT INTO TUESDAY MORNING WITH 30 KTS EXPECTED BY TUESDAY
MORNING AND THERE COULD BE SOME LOW END GALE GUSTS BUT CONFIDENCE
REGARDING FREQUENCY IS LOW. WINDS WILL SHIFT TO THE SOUTHWEST IN
THE AFTERNOON AND THEN TO THE NORTHWEST TUESDAY NIGHT. SPEEDS WILL
LIKELY REMAIN IN THE 30 KT RANGE...ESPECIALLY ACROSS THE SOUTHERN
TWO THIRDS...AS HIGH PRESSURE BUILDS ACROSS THE PLAINS WEDNESDAY
AND COLD AIR OVERSPREADS THE REGION. THIS HIGH WILL EXTEND FROM
THE SOUTHERN PLAINS TO THE OHIO VALLEY THURSDAY AS WINDS TURN MORE
WESTERLY AND BEGIN TO SLOWLY DIMINISH. BUT AS THE HIGH DEPARTS
THURSDAY NIGHT...THE GRADIENT WILL TIGHTEN AS LOW PRESSURE MOVES
ACROSS NORTHERN ONTARIO WITH A PERIOD OF SOUTHWEST WINDS TO 30 KTS
ON FRIDAY...WITH SOME LOW END GALES POSSIBLE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...3 AM TUESDAY TO NOON
TUESDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...3
AM TUESDAY TO NOON TUESDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...6 AM TUESDAY TO 6 PM WEDNESDAY.
&&
$$
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
NWS CHICAGO/ROMEOVILLE IL
418 PM CST MON MAR 2 2015
.SHORT TERM...
317 PM CST
THROUGH WEDNESDAY...
.SHORT TERM...THROUGH WEDNESDAY
AS MENTIONED IN THE EARLIER UPDATE... A WINTER WEATHER ADVISORY
WAS ISSUED FOR THE ENTIRE AREA EARLIER IN THE SHIFT FOR LATE
TONIGHT THROUGH TUESDAY MORNING. MODELS ARE STILL SHOWING
PRECIPITATION BEGINNING AS SNOW NORTH OF INTERSTATE 80...AND SOME
FORM OF SNOW...SLEET OR FREEZING RAIN IN THE FAR SOUTH. IT COULD
BE A PRETTY GOOD BURST OF WET SNOW INITIALLY BEFORE THE TRANSITION
BEGINS.
A WARM FRONT WILL LIFT THROUGH THE AREA DURING THE MORNING HOURS.
THIS IS THE PERIOD WHERE MODELS A SHOWING A MORE SIGNIFICANT PUSH
OF PRECIPITATION. WE ARE COMING OUT OF A PRETTY COLD AIR
MASS..AND DEWPOINTS ARE STILL VERY LOW ACROSS THE AREA...WITH
DEWPOINTS ABOVE FREEZING NOT VERY CLOSE. TEMPERATURES LOOK TO
REMAIN BELOW FREEZING THROUGH AT LEAST MID MORNING AREA WIDE.
MODEST PRECIPITABLE WATER VALUES IN EXCESS OF 0.75 INCHES COUPLED
WITH A 35-40 KT LOW LEVEL JET FEEDING INTO THE LOW LEVEL FRONTAL
ZONE WOULD SUGGEST MODEST PRECIPITATION RATES DURING THIS TIME WHEN
THE LOW LEVEL (925-850 MB) TEMPERATURES ARE HEADING ABOVE
FREEZING. SOME OF THE RECENT NAM/GFS WAS SLIGHTLY COOLER IN THE
THERMAL PROFILE FOR THIS PERIOD SUGGESTING THAT SNOW/SLEET MAY
DOMINATE...ESPECIALLY FOR THE NORTHERN METRO AREA AND POINTS NORTH
TOWARD WISCONSIN... AND IF PRECIPITATION RATES CONTINUE A BIT
HEAVIER THIS MAY SLOW THE LOW LEVEL WARMING. BUT THE SIGNAL IS
STILL THERE FOR A SNOW-SLEET-FZRA TRANSITION AND ICE ACCUMULATION
POTENTIAL.
WHERE THE UNCERTAINTIES REMAIN IS IN REGARDS TO HOW MUCH ICE
ACCUMULATION WILL OCCUR AND HOW FAR NORTH THE IMPACTS ARE FELT. ICE IS
EXPECTED TO BE THE LEAST NORTH TOWARDS WISCONSIN AND IN THE
ROCKFORD AREA WHERE IT MAY JUST BE AN ALL SNOW/SLEET SITUATION
WHERE ADVISORY CRITERIA MAY NOT BE TECHNICALLY SATISFIED. GIVEN
THE UNCERTAINTY AND THE RUSH-HOUR TIME...FEEL IT IS THE SAFER CALL
WITH SOME SNOW/SLEET AS WELL. AND IN NW INDIANA...THE BETTER
MOISTURE ADVECTION IS FOCUSED HERE WHERE THERE IS HIGHER POTENTIAL
FOR ICE ACCUMULATION...BUT IT WILL BE A RACE AGAINST SURFACE TEMPS
AS WELL WHICH LOOK TO WARM THROUGH THE MORNING. AS MENTIONED
EARLIER...MEANWHILE...THE ECMWF/GEM ARE MORE SUPPORTIVE OF A
SNOW/SLEET SOLUTION IN MANY AREAS...ESPECIALLY NORTH OF INTERSTATE
80. IT LOOKS LIKE THE TRANSITION TIME FOR MIXED PRECIPITATION
SOUTH OF I-80 WILL OCCUR BEFORE DAYBREAK BASED ON THE NAM AND
EARLY LOOKS AT THE RAP CLOSE TO THAT TIME FRAME. IT WOULD LIKELY
BE AFTER 6-7 AM WHEN THAT TRANSITION OCCURS IN THE METRO
AREA...BUT CONFIDENCE ON THAT TIMING IS NOT SUPER HIGH.
WHILE WE ARE LOSING THE DEEPER MOISTURE IN THE AFTERNOON...WE ARE
GETTING SOME DECENT MID LEVEL FRONTOGENESIS WHICH SHOULD STILL ALLOW
US TO WRING OUT SOME PRECIPITATION IN THE AFTERNOON WHICH COULD BE A
SNOW-RAIN MIX IN THE NW...LIKELY RAIN IN THE SE...WITH EVEN SOME
-SN/DZ/FZDZ POSSIBLE ACROSS THE CHICAGO METRO AREA LATE IN THE
AFTERNOON AND EVENING.
THE UPPER TROUGH AXIS WILL GRADUALLY MOVE THROUGH THE AREA WHILE
SURFACE HIGH PRESSURE NOSES IN FROM THE NORTHWEST. EXPECT COLDER
CONDITIONS WITH SOME HIGH CLOUDS MOVING THROUGH. HIGHS WILL BE IN
THE TEENS WEDNESDAY AND THURSDAY...WITH LOWS EARLY THURSDAY MORNING
BOTTOMING OUT AT OR BELOW ZERO. WITH THE HIGH STILL TO THE
EAST...WIND CHILLS...YES WE ARE STILL DISCUSSING WIND CHILLS IN
EARLY MARCH...GET DOWN TO -10 TO -20 BELOW. A CLIMATE SECTION TO
THE AFD WILL BE FORTHCOMING.
KMD
&&
.LONG TERM...
317 PM CST
THURSDAY THROUGH MONDAY...
THE EXTENDED PERIOD WILL START OUT VERY COLD AS A 1040 MB ARCTIC
HIGH SHIFTS ACROSS THE REGION. WITH 925 AND 850 MB TEMPERATURES
PROGGED TO BE AROUND -18 CELSIUS...THIS SHOULD ONLY ALLOW FOR HIGHS
IN THE MIDDLE TO UPPER TEENS...FOLLOWING A BITTERLY COLD AND
POTENTIALLY RECORD COLD MORNING. THE GOOD NEWS IS THAT THIS WILL BE
A PROGRESSIVE HIT OF ARCTIC AIR. IN FACT...TEMPERATURES SHOULD
QUICKLY RECOVER BY FRIDAY AS A GUSTY SOUTH-SOUTHWESTERLY FLOW SETS
UP ALONG THE NORTHWESTERN PERIPHERY OF THE EXITING SURFACE RIDGE OF
HIGH PRESSURE. THIS SHOULD SUPPORT HIGHS INTO THE LOW 30S
FRIDAY...AND POSSIBLY WELL INTO THE 30S FOR THE WEEKEND. A WEAK COLD
FRONT MAY DROP ACROSS THE AREA OVER THE WEEKEND...BUT IT APPEARS THE
DEEPER COLD WILL BE AIMED TO OUR NORTHEAST. PRECIPITATION CHANCES
ALSO APPEAR TO BE MINIMAL DURING MUCH OF THE EXTENDED PERIOD.
KJB
&&
.CLIMATE...
417 PM CST
A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN
JEOPARDY ON WEDNESDAY AND THURSDAY.
HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT
STAND THE BEST CHANCE TO BE REACHED ORBROKEN HAVE A STAR (*) NEXT TO
THEM.
WED 3/4 THU 3/5
ROCKFORD
RECORD LOW-11 (2002)-11 (2002)
RECORD LOW MAX 14 (2002)* 17 (1960)*
CHICAGO
RECORD LOW-12 (1873) 0 (1978)*
RECORD LOW MAX 17 (1890)* 12 (1901)
KMD/KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LIGHT/VARIABLE WINDS THIS AFTERNOON BEFORE FLOPPING SOUTHEAST BY
EARLY EVENING. SOUTH-SOUTHEAST WINDS BECOMING GUSTY 20-25 KT BY
TUESDAY MORNING.
* SNOW...MIXING WITH SLEET THEN CHANGING TO FREEZING RAIN/RAIN
EARLY TUESDAY MORNING. VFR CONDITIONS TO QUICKLY DETERIORATE TO
IFR/LIFR IN PRECIP.
KJB
//DISCUSSION...UPDATED 18Z...
IT WILL CONTINUE TO BE A QUIET WEATHER DAY ACROSS THE AREA TODAY. A
SURFACE RIDGE OF HIGH PRESSURE PUSHING ACROSS THE AREA THIS
AFTERNOON WILL RESULT IN A PERIOD OF LIGHT AND VARIABLE
WINDS...THOUGH THE WINDS SHOULD SETTLE INTO A SOUTHEASTERLY DIRECTION
BY EARLY THIS EVENING. OTHERWISE VFR CONDITIONS EXPECTED.
THE WEATHER WILL BECOME MUCH MORE PROBLEMATIC BY DAYBREAK TUESDAY.
WINDS WILL INCREASE OUT OF THE SOUTHEAST AND BECOME GUSTY DURING THE
MORNING. SNOW WILL ALSO DEVELOP OVER THE AREA JUST PRIOR TO
DAYBREAK...BEFORE MIXING WITH SLEET AND CHANGING OVER TO A PERIOD OF
FREEZING RAIN BY MID MORNING TUESDAY. IT CURRENTLY APPEARS THAT
ABOUT A 1 TO 3 HOUR PERIOD OF SNOW AND SLEET WILL OCCUR FROM ROUGHLY
11 UTC THROUGH 13 TO 15 UTC. DURING THIS PERIOD IFR VIS IN SNOW AND
LOWERING CIGS ARE LIKELY. CIGS WILL CONTINUE TO DETERIORATE INTO THE
IFR AND LIFR CATEGORIES DURING THE MORNING AS WARMER AIR ALOFT
BEGINS TO CHANGE THE SNOW AND SLEET OVER TO SOME FREEZING RAIN.
SURFACE TEMPERATURES SHOULD ALSO BE ON A WARMING TREND DURING THE
MORNING...AND ARE EXPECTED TO WARM ABOVE FREEZING BY MIDDAY...SO ANY
LINGERING PRECIP AFTER THIS TIME WILL LIKELY NO LONGER PRODUCE A
FREEZING THREAT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM-HIGH IN PRECIP TIMING/TREND EARLY TUESDAY. MEDIUM IN
CIG/VIS IMPACTS.
* HIGH ALL OTHER ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...MVFR CIGS. GUSTY WEST WINDS.
WEDNESDAY...MVFR CIGS.
THURSDAY AND FRIDAY...VFR.
SATURDAY AND SUNDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
224 PM...HIGH PRESSURE OVER THE SOUTHERN LAKES AND OHIO VALLEY
WILL MOVE EAST TO THE MID ATLANTIC AND NEW ENGLAND TUESDAY MORNING
AS LOW PRESSURE FORMS OVER THE CENTRAL PLAINS TONIGHT. THIS LOW
WILL QUICKLY MOVE NORTHEAST TUESDAY AND BE ABSORBED BY STRONGER
LOW PRESSURE OVER NORTHERN ONTARIO...AS A COLD FRONT MOVES ACROSS
LAKE MICHIGAN. THE GRADIENT WILL SLOWLY INCREASE AHEAD OF THIS LOW
TONIGHT INTO TUESDAY MORNING WITH 30 KTS EXPECTED BY TUESDAY
MORNING AND THERE COULD BE SOME LOW END GALE GUSTS BUT CONFIDENCE
REGARDING FREQUENCY IS LOW. WINDS WILL SHIFT TO THE SOUTHWEST IN
THE AFTERNOON AND THEN TO THE NORTHWEST TUESDAY NIGHT. SPEEDS WILL
LIKELY REMAIN IN THE 30 KT RANGE...ESPECIALLY ACROSS THE SOUTHERN
TWO THIRDS...AS HIGH PRESSURE BUILDS ACROSS THE PLAINS WEDNESDAY
AND COLD AIR OVERSPREADS THE REGION. THIS HIGH WILL EXTEND FROM
THE SOUTHERN PLAINS TO THE OHIO VALLEY THURSDAY AS WINDS TURN MORE
WESTERLY AND BEGIN TO SLOWLY DIMINISH. BUT AS THE HIGH DEPARTS
THURSDAY NIGHT...THE GRADIENT WILL TIGHTEN AS LOW PRESSURE MOVES
ACROSS NORTHERN ONTARIO WITH A PERIOD OF SOUTHWEST WINDS TO 30 KTS
ON FRIDAY...WITH SOME LOW END GALES POSSIBLE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...3 AM TUESDAY TO NOON
TUESDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...3
AM TUESDAY TO NOON TUESDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...6 AM TUESDAY TO 6 PM WEDNESDAY.
&&
$$
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
NWS CHICAGO/ROMEOVILLE IL
323 PM CST MON MAR 2 2015
.SHORT TERM...
317 PM CST
THROUGH WEDNESDAY...
.SHORT TERM...THROUGH WEDNESDAY
AS MENTIONED IN THE EARLIER UPDATE... A WINTER WEATHER ADVISORY
WAS ISSUED FOR THE ENTIRE AREA EARLIER IN THE SHIFT FOR LATE
TONIGHT THROUGH TUESDAY MORNING. MODELS ARE STILL SHOWING
PRECIPITATION BEGINNING AS SNOW NORTH OF INTERSTATE 80...AND SOME
FORM OF SNOW...SLEET OR FREEZING RAIN IN THE FAR SOUTH. IT COULD
BE A PRETTY GOOD BURST OF WET SNOW INITIALLY BEFORE THE TRANSITION
BEGINS.
A WARM FRONT WILL LIFT THROUGH THE AREA DURING THE MORNING HOURS.
THIS IS THE PERIOD WHERE MODELS A SHOWING A MORE SIGNIFICANT PUSH
OF PRECIPITATION. WE ARE COMING OUT OF A PRETTY COLD AIR
MASS..AND DEWPOINTS ARE STILL VERY LOW ACROSS THE AREA...WITH
DEWPOINTS ABOVE FREEZING NOT VERY CLOSE. TEMPERATURES LOOK TO
REMAIN BELOW FREEZING THROUGH AT LEAST MID MORNING AREA WIDE.
MODEST PRECIPITABLE WATER VALUES IN EXCESS OF 0.75 INCHES COUPLED
WITH A 35-40 KT LOW LEVEL JET FEEDING INTO THE LOW LEVEL FRONTAL
ZONE WOULD SUGGEST MODEST PRECIPITATION RATES DURING THIS TIME WHEN
THE LOW LEVEL (925-850 MB) TEMPERATURES ARE HEADING ABOVE
FREEZING. SOME OF THE RECENT NAM/GFS WAS SLIGHTLY COOLER IN THE
THERMAL PROFILE FOR THIS PERIOD SUGGESTING THAT SNOW/SLEET MAY
DOMINATE...ESPECIALLY FOR THE NORTHERN METRO AREA AND POINTS NORTH
TOWARD WISCONSIN... AND IF PRECIPITATION RATES CONTINUE A BIT
HEAVIER THIS MAY SLOW THE LOW LEVEL WARMING. BUT THE SIGNAL IS
STILL THERE FOR A SNOW-SLEET-FZRA TRANSITION AND ICE ACCUMULATION
POTENTIAL.
WHERE THE UNCERTAINTIES REMAIN IS IN REGARDS TO HOW MUCH ICE
ACCUMULATION WILL OCCUR AND HOW FAR NORTH THE IMPACTS ARE FELT. ICE IS
EXPECTED TO BE THE LEAST NORTH TOWARDS WISCONSIN AND IN THE
ROCKFORD AREA WHERE IT MAY JUST BE AN ALL SNOW/SLEET SITUATION
WHERE ADVISORY CRITERIA MAY NOT BE TECHNICALLY SATISFIED. GIVEN
THE UNCERTAINTY AND THE RUSH-HOUR TIME...FEEL IT IS THE SAFER CALL
WITH SOME SNOW/SLEET AS WELL. AND IN NW INDIANA...THE BETTER
MOISTURE ADVECTION IS FOCUSED HERE WHERE THERE IS HIGHER POTENTIAL
FOR ICE ACCUMULATION...BUT IT WILL BE A RACE AGAINST SURFACE TEMPS
AS WELL WHICH LOOK TO WARM THROUGH THE MORNING. AS MENTIONED
EARLIER...MEANWHILE...THE ECMWF/GEM ARE MORE SUPPORTIVE OF A
SNOW/SLEET SOLUTION IN MANY AREAS...ESPECIALLY NORTH OF INTERSTATE
80. IT LOOKS LIKE THE TRANSITION TIME FOR MIXED PRECIPITATION
SOUTH OF I-80 WILL OCCUR BEFORE DAYBREAK BASED ON THE NAM AND
EARLY LOOKS AT THE RAP CLOSE TO THAT TIME FRAME. IT WOULD LIKELY
BE AFTER 6-7 AM WHEN THAT TRANSITION OCCURS IN THE METRO
AREA...BUT CONFIDENCE ON THAT TIMING IS NOT SUPER HIGH.
WHILE WE ARE LOSING THE DEEPER MOISTURE IN THE AFTERNOON...WE ARE
GETTING SOME DECENT MID LEVEL FRONTOGENESIS WHICH SHOULD STILL ALLOW
US TO WRING OUT SOME PRECIPITATION IN THE AFTERNOON WHICH COULD BE A
SNOW-RAIN MIX IN THE NW...LIKELY RAIN IN THE SE...WITH EVEN SOME
-SN/DZ/FZDZ POSSIBLE ACROSS THE CHICAGO METRO AREA LATE IN THE
AFTERNOON AND EVENING.
THE UPPER TROUGH AXIS WILL GRADUALLY MOVE THROUGH THE AREA WHILE
SURFACE HIGH PRESSURE NOSES IN FROM THE NORTHWEST. EXPECT COLDER
CONDITIONS WITH SOME HIGH CLOUDS MOVING THROUGH. HIGHS WILL BE IN
THE TEENS WEDNESDAY AND THURSDAY...WITH LOWS EARLY THURSDAY MORNING
BOTTOMING OUT AT OR BELOW ZERO. WITH THE HIGH STILL TO THE
EAST...WIND CHILLS...YES WE ARE STILL DISCUSSING WIND CHILLS IN
EARLY MARCH...GET DOWN TO -10 TO -20 BELOW. A CLIMATE SECTION TO
THE AFD WILL BE FORTHCOMING.
KMD
&&
.LONG TERM...
317 PM CST
THURSDAY THROUGH MONDAY...
THE EXTENDED PERIOD WILL START OUT VERY COLD AS A 1040 MB ARCTIC
HIGH SHIFTS ACROSS THE REGION. WITH 925 AND 850 MB TEMPERATURES
PROGGED TO BE AROUND -18 CELSIUS...THIS SHOULD ONLY ALLOW FOR HIGHS
IN THE MIDDLE TO UPPER TEENS...FOLLOWING A BITTERLY COLD AND
POTENTIALLY RECORD COLD MORNING. THE GOOD NEWS IS THAT THIS WILL BE
A PROGRESSIVE HIT OF ARCTIC AIR. IN FACT...TEMPERATURES SHOULD
QUICKLY RECOVER BY FRIDAY AS A GUSTY SOUTH-SOUTHWESTERLY FLOW SETS
UP ALONG THE NORTHWESTERN PERIPHERY OF THE EXITING SURFACE RIDGE OF
HIGH PRESSURE. THIS SHOULD SUPPORT HIGHS INTO THE LOW 30S
FRIDAY...AND POSSIBLY WELL INTO THE 30S FOR THE WEEKEND. A WEAK COLD
FRONT MAY DROP ACROSS THE AREA OVER THE WEEKEND...BUT IT APPEARS THE
DEEPER COLD WILL BE AIMED TO OUR NORTHEAST. PRECIPITATION CHANCES
ALSO APPEAR TO BE MINIMAL DURING MUCH OF THE EXTENDED PERIOD.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LIGHT/VARIABLE WINDS THIS AFTERNOON BEFORE FLOPPING SOUTHEAST BY
EARLY EVENING. SOUTH-SOUTHEAST WINDS BECOMING GUSTY 20-25 KT BY
TUESDAY MORNING.
* SNOW...MIXING WITH SLEET THEN CHANGING TO FREEZING RAIN/RAIN
EARLY TUESDAY MORNING. VFR CONDITIONS TO QUICKLY DETERIORATE TO
IFR/LIFR IN PRECIP.
KJB
//DISCUSSION...UPDATED 18Z...
IT WILL CONTINUE TO BE A QUIET WEATHER DAY ACROSS THE AREA TODAY. A
SURFACE RIDGE OF HIGH PRESSURE PUSHING ACROSS THE AREA THIS
AFTERNOON WILL RESULT IN A PERIOD OF LIGHT AND VARIABLE
WINDS...THOUGH THE WINDS SHOULD SETTLE INTO A SOUTHEASTERLY DIRECTION
BY EARLY THIS EVENING. OTHERWISE VFR CONDITIONS EXPECTED.
THE WEATHER WILL BECOME MUCH MORE PROBLEMATIC BY DAYBREAK TUESDAY.
WINDS WILL INCREASE OUT OF THE SOUTHEAST AND BECOME GUSTY DURING THE
MORNING. SNOW WILL ALSO DEVELOP OVER THE AREA JUST PRIOR TO
DAYBREAK...BEFORE MIXING WITH SLEET AND CHANGING OVER TO A PERIOD OF
FREEZING RAIN BY MID MORNING TUESDAY. IT CURRENTLY APPEARS THAT
ABOUT A 1 TO 3 HOUR PERIOD OF SNOW AND SLEET WILL OCCUR FROM ROUGHLY
11 UTC THROUGH 13 TO 15 UTC. DURING THIS PERIOD IFR VIS IN SNOW AND
LOWERING CIGS ARE LIKELY. CIGS WILL CONTINUE TO DETERIORATE INTO THE
IFR AND LIFR CATEGORIES DURING THE MORNING AS WARMER AIR ALOFT
BEGINS TO CHANGE THE SNOW AND SLEET OVER TO SOME FREEZING RAIN.
SURFACE TEMPERATURES SHOULD ALSO BE ON A WARMING TREND DURING THE
MORNING...AND ARE EXPECTED TO WARM ABOVE FREEZING BY MIDDAY...SO ANY
LINGERING PRECIP AFTER THIS TIME WILL LIKELY NO LONGER PRODUCE A
FREEZING THREAT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM-HIGH IN PRECIP TIMING/TREND EARLY TUESDAY. MEDIUM IN
CIG/VIS IMPACTS.
* HIGH ALL OTHER ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...MVFR CIGS. GUSTY WEST WINDS.
WEDNESDAY...MVFR CIGS.
THURSDAY AND FRIDAY...VFR.
SATURDAY AND SUNDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
224 PM...HIGH PRESSURE OVER THE SOUTHERN LAKES AND OHIO VALLEY
WILL MOVE EAST TO THE MID ATLANTIC AND NEW ENGLAND TUESDAY MORNING
AS LOW PRESSURE FORMS OVER THE CENTRAL PLAINS TONIGHT. THIS LOW
WILL QUICKLY MOVE NORTHEAST TUESDAY AND BE ABSORBED BY STRONGER
LOW PRESSURE OVER NORTHERN ONTARIO...AS A COLD FRONT MOVES ACROSS
LAKE MICHIGAN. THE GRADIENT WILL SLOWLY INCREASE AHEAD OF THIS LOW
TONIGHT INTO TUESDAY MORNING WITH 30 KTS EXPECTED BY TUESDAY
MORNING AND THERE COULD BE SOME LOW END GALE GUSTS BUT CONFIDENCE
REGARDING FREQUENCY IS LOW. WINDS WILL SHIFT TO THE SOUTHWEST IN
THE AFTERNOON AND THEN TO THE NORTHWEST TUESDAY NIGHT. SPEEDS WILL
LIKELY REMAIN IN THE 30 KT RANGE...ESPECIALLY ACROSS THE SOUTHERN
TWO THIRDS...AS HIGH PRESSURE BUILDS ACROSS THE PLAINS WEDNESDAY
AND COLD AIR OVERSPREADS THE REGION. THIS HIGH WILL EXTEND FROM
THE SOUTHERN PLAINS TO THE OHIO VALLEY THURSDAY AS WINDS TURN MORE
WESTERLY AND BEGIN TO SLOWLY DIMINISH. BUT AS THE HIGH DEPARTS
THURSDAY NIGHT...THE GRADIENT WILL TIGHTEN AS LOW PRESSURE MOVES
ACROSS NORTHERN ONTARIO WITH A PERIOD OF SOUTHWEST WINDS TO 30 KTS
ON FRIDAY...WITH SOME LOW END GALES POSSIBLE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...3 AM TUESDAY TO NOON
TUESDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...3
AM TUESDAY TO NOON TUESDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...6 AM TUESDAY TO 6 PM WEDNESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS DODGE CITY KS
348 PM CST MON MAR 2 2015
...UPDATED LONG TERM SECTION...
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 140 PM CST MON MAR 2 2015
AN AREA OF LOW PRESSURE AT THE SURFACE WILL DEEPEN ALONG THE LEE
OF THE ROCKIES EARLY TONIGHT WHICH WILL KEEP A TIGHT SURFACE
PRESSURE GRADIENT IN PLACE ACROSS WESTERN KANSAS. THESE GUSTY
WINDS WILL KEEP THE ATMOSPHERE NEAR THE SURFACE MIXED AND BASED ON
EXPECTED CLOUD COVER THE TEMPERATURES OVERNIGHT ARE NOT EXPECTED
TO FALL MUCH. LOWS TONIGHT ACROSS WESTERN KANSAS WILL BE AROUND 32
DEGREES. THE SOUTHERLY WINDS TONIGHT WILL ALSO DRAW MORE HUMID AIR
BACK INTO THE SOUTHWEST KANSAS WHICH WILL RESULT IN AREAS OF FOG
DEVELOPING, ESPECIALLY AFTER MIDNIGHT. AT THIS TIME DENSE FOG IS
NOT ANTICIPATED GIVEN THE MIXING EXPECTED NEAR THE SURFACE
OVERNIGHT.
A COLD FRONT WILL CROSS WESTERN KANSAS ON TUESDAY AS AN UPPER
LEVEL TROUGH CROSSES THE CENTRAL HIGH PLAINS. THE LOW CLOUDS AND
AREAS OF FOG AHEAD OF THIS SURFACE BOUNDARY WILL SHIFT EAST EARLY
IN THE DAY AS THE SOUTH WINDS BECOME NORTHWEST AT 20 TO 25 MPH.
SUBSIDENCE AND DRYING THE THE LOWER LEVELS MAY GIVE RISE TO SOME
BRIEF CLEARING LATE MORNING, HOWEVER AFTERNOON CLOUDS ARE EXPECTED
TO RETURN BASED LINGERING MOISTURE IN THE 900 TO 850MB LEVEL AND
SOME AFTERNOON WARMING. MODELS DO INDICATED SOME COOLING WILL
OCCUR DURING THE AFTERNOON BEHIND THIS FRONT SO WILL FAVOR AN
EARLY HIGH AROUND 40 ACROSS NORTH CENTRAL AND WEST CENTRAL KANSAS.
GIVEN A LATER FRONTAL PASSAGE THE HIGHS WILL BE WARMER FURTHER
SOUTH.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 PM CST MON MAR 2 2015
A CHANGE OF IMPORTANCE WAS MADE IN THE FORECAST REGARDING TUESDAY
NIGHT AND WEDNESDAY -- THAT BEING THE INCREASE IN SNOW CHANCES.
THE ENTIRE NEW 12Z SUITE OF MODELS, INCLUDING BOTH GLOBAL AN
LIMITED AREA HIGH- RESOLUTION, SHOW ANYWHERE FROM FIVE-HUNDREDTHS
OF AN INCH OF QPF TO TWO-TENTHS OF AN INCH, PRIMARILY ACROSS FAR
SOUTH CENTRAL KANSAS NEAR THE OKLAHOMA BORDER. ALL THE MODELS ARE
APPARENTLY STILL TRYING TO PLAY CATCH UP TO WHAT THE REAL
ATMOSPHERE IS WANTING TO DO...SINCE TWO AIR STREAMS ARE INVOLVED.
THE PHASING/INTERACTION BETWEEN THE NORTHERN AND SOUTHERN BRANCH
JET STREAMS IS ALWAYS A PROBLEMATIC CHALLENGE, EVEN TWO DAYS OUT.
AS SUCH, IT APPEARS MORE JET ENERGY FROM THE NORTHERN BRANCH MAY
BECOME INVOLVED WITH THE SOUTHERN BRANCH LATE TUESDAY AND TUESDAY
NIGHT, EFFECTIVELY SLOWING THE ENTIRE TROUGH AXIS DOWN ENOUGH TO
DELAY THE ONSET OF THE 700MB FRONT.
A SLOWER 700MB ARCTIC FRONT PASSAGE WOULD MEAN MORE TIME FOR
PACIFIC AND GULF MOISTURE TO WORK ITS WAY FAR ENOUGH NORTHWEST TO
REALIZE PRECIPITATION...AND IT APPEARS THAT IS WHAT THE MODELS ARE
ALL TRYING TO DO NOW. FROM LATE TUESDAY NIGHT THROUGH MIDDAY
WEDNESDAY, THE GFS, NAM12, AND ECMWF ALL SHOW A TIGHT 700MB
BAROCLINIC ZONE MOVING FAIRLY SLOWLY SOUTH THROUGH THE PERIOD...WITH
A MOISTENING OF THE 800-600MB AIRMASS TO THE POINT OF SATURATION,
ESPECIALLY BY 12Z WEDNESDAY AS THE MOIST SOUTHWEST MOMENTUM
REACHES THE ADVANCING FRONT. THIS SOUTHWEST TO NORTHEAST
ORIENTATION OF INCREASED FRONTOGENESIS WOULD SUPPORT THE LIFT
NECESSARY TO PRODUCE AT LEAST SUSTAINED LIGHT PRECIPITATION, IF
NOT A CORRIDOR OF BANDED HEAVIER PRECIPITATION. ALL THIS IS
JUSTIFICATION ENOUGH TO INCREASE POPS ACROSS THE BOARD, INCLUDING
SOME 55+ LIKELY POPS ACROSS FAR SOUTH CENTRAL KANSAS ALONG THE
OKLAHOMA BORDER. AT THIS TIME, ONE TO TWO INCHES OF SNOW IS IN
THE LATEST OFFICIAL FORECAST FOR THIS NEXT EVENT IN THE LIKELY
POPS AREA (MAINLY ASHLAND TO COLDWATER TO MEDICINE LODGE AND
KIOWA) WITH A HALF INTO TO INCH FARTHER NORTH.
BEYOND THIS STORM, A WARMING TREND IS STILL ANTICIPATED LATE IN THE
WEEK AS WE ENTER A WEST-NORTHWEST DOWNSLOPE FLOW REGIME. WIDESPREAD
50S APPEAR LIKELY BY FRIDAY WHICH WOULD CONTINUE INTO THE WEEKEND. A
VERY MINOR NORTHWEST FLOW DISTURBANCE WILL LIKELY ROTATE THROUGH THE
PATTERN AT SOME POINT DURING THE UPCOMING WEEKEND, BUT THERE WILL BE
NEGLIGIBLE BAROCLINICITY AND MOISTURE TO WORK WITH TO PRODUCE ANY
PRECIPITATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1112 AM CST MON MAR 2 2015
THE RAP, HRRR AND NAM BUFR SOUNDINGS WERE ALL IN GOOD AGREEMENT
WITH LOW LEVEL MOISTURE INCREASING ACROSS SOUTHWEST KANSAS THIS
AFTERNOON AND OVERNIGHT. AT THIS TIME THE DEPTH OF THIS LOW LEVEL
MOISTURE WILL BE SHALLOW ENOUGH THAT DRIZZLE/FREEZING DRIZZLE WILL
NOT BE AN ISSUE. DENSE FOG ALSO IS NOT ANTICIPATED GIVEN THAT THE
SURFACE WINDS WILL BE AT 15 TO 20 KNOTS AND THE 0-1KM MEAN WINDS
WILL BE INCREASING TO NEAR 50 KNOTS OVERNIGHT. VISIBILITIES AS LOW
AS ONE MILE HOWEVER WILL BE POSSIBLE AT TIMES OVERNIGHT AND
CEILINGS ARE EXPECTED TO FALL BACK INTO THE LIFR CATEGORY AFTER
00Z TUESDAY AT GCK AND DDC AND AFTER 03Z AT HYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 33 45 15 27 / 10 10 20 20
GCK 32 42 13 25 / 10 10 30 20
EHA 34 46 15 25 / 10 10 50 20
LBL 33 50 16 26 / 10 10 50 20
HYS 31 41 12 27 / 10 10 30 10
P28 30 49 18 29 / 10 10 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...UMSCHEID
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
143 PM CST MON MAR 2 2015
...UPDATED SHORT TERM DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 140 PM CST MON MAR 2 2015
AN AREA OF LOW PRESSURE AT THE SURFACE WILL DEEPEN ALONG THE LEE
OF THE ROCKIES EARLY TONIGHT WHICH WILL KEEP A TIGHT SURFACE
PRESSURE GRADIENT IN PLACE ACROSS WESTERN KANSAS. THESE GUSTY
WINDS WILL KEEP THE ATMOSPHERE NEAR THE SURFACE MIXED AND BASED ON
EXPECTED CLOUD COVER THE TEMPERATURES OVERNIGHT ARE NOT EXPECTED
TO FALL MUCH. LOWS TONIGHT ACROSS WESTERN KANSAS WILL BE AROUND 32
DEGREES. THE SOUTHERLY WINDS TONIGHT WILL ALSO DRAW MORE HUMID AIR
BACK INTO THE SOUTHWEST KANSAS WHICH WILL RESULT IN AREAS OF FOG
DEVELOPING, ESPECIALLY AFTER MIDNIGHT. AT THIS TIME DENSE FOG IS
NOT ANTICIPATED GIVEN THE MIXING EXPECTED NEAR THE SURFACE
OVERNIGHT.
A COLD FRONT WILL CROSS WESTERN KANSAS ON TUESDAY AS AN UPPER
LEVEL TROUGH CROSSES THE CENTRAL HIGH PLAINS. THE LOW CLOUDS AND
AREAS OF FOG AHEAD OF THIS SURFACE BOUNDARY WILL SHIFT EAST EARLY
IN THE DAY AS THE SOUTH WINDS BECOME NORTHWEST AT 20 TO 25 MPH.
SUBSIDENCE AND DRYING THE THE LOWER LEVELS MAY GIVE RISE TO SOME
BRIEF CLEARING LATE MORNING, HOWEVER AFTERNOON CLOUDS ARE EXPECTED
TO RETURN BASED LINGERING MOISTURE IN THE 900 TO 850MB LEVEL AND
SOME AFTERNOON WARMING. MODELS DO INDICATED SOME COOLING WILL
OCCUR DURING THE AFTERNOON BEHIND THIS FRONT SO WILL FAVOR AN
EARLY HIGH AROUND 40 ACROSS NORTH CENTRAL AND WEST CENTRAL KANSAS.
GIVEN A LATER FRONTAL PASSAGE THE HIGHS WILL BE WARMER FURTHER
SOUTH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 409 AM CST MON MAR 2 2015
A STRONG SHORTWAVE TROUGH DROPPING OUT OF WESTERN CANADA TODAY AND
TONIGHT WILL PHASE WITH THE UPPER LOW/TROUGH SYSTEM THAT HAS BEEN
SITUATED OVER CALIFORNIA AND NEVADA THE PAST FEW DAYS AND MOVE EAST
ACROSS THE NORTHERN AND CENTRAL CONUS THROUGH THE NEXT FEW DAYS.
THIS WILL PUSH A COLD FRONT SOUTH ACROSS WESTERN KANSAS TUESDAY
MORNING. TEMPERATURES MAY ONLY RISE A LITTLE OR HOLD STEADY ACROSS
WEST CENTRAL KANSAS WHERE THE FRONT WILL BE COMING THROUGH EARLIEST
IN THE DAY. LOCATIONS ALONG THE OKLAHOMA BORDER INTO SOUTH CENTRAL
KANSAS COULD SEE TEMPERATURES RISING INTO THE 40S DURING THE MORNING
BEFORE FALLING BACK AFTER THE FRONT MOVES THROUGH. MODEL SOUNDINGS
ARE NOT OVERLY MOIST IMMEDIATELY BEHIND THE FRONT AND SKIES SHOULD
BE PARTLY TO MOSTLY CLOUDY DURING THE DAY.
BY TUESDAY NIGHT THE UPPER TROUGH BEGINS TO MOVE OUT ACROSS THE
CENTRAL PLAINS. WILL CONTINUE TO CARRY THE SLIGHT CHANCE TO CHANCE
POPS DURING THE NIGHT INTO WEDNESDAY MORNING AS MODEL SOUNDINGS
MOISTEN UP SOMEWHAT AND MID LEVEL FRONTOGENETIC FORCING MOVES OVER
THE AREA. PRECIPITATION CHANCES WILL DIMINISH WITH DECREASING CLOUDS
BY WEDNESDAY AFTERNOON AS THE UPPER TROUGH MOVES THROUGH.
THE REMAINDER OF THE WEEK WILL SEE NORTHWEST FLOW ALOFT OVER THE
CENTRAL HIGH PLAINS. THIS WILL RESULT IN DRY WEATHER WITH
TEMPERATURES MODERATING INTO THE 50S FOR THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1112 AM CST MON MAR 2 2015
THE RAP, HRRR AND NAM BUFR SOUNDINGS WERE ALL IN GOOD AGREEMENT
WITH LOW LEVEL MOISTURE INCREASING ACROSS SOUTHWEST KANSAS THIS
AFTERNOON AND OVERNIGHT. AT THIS TIME THE DEPTH OF THIS LOW LEVEL
MOISTURE WILL BE SHALLOW ENOUGH THAT DRIZZLE/FREEZING DRIZZLE WILL
NOT BE AN ISSUE. DENSE FOG ALSO IS NOT ANTICIPATED GIVEN THAT THE
SURFACE WINDS WILL BE AT 15 TO 20 KNOTS AND THE 0-1KM MEAN WINDS
WILL BE INCREASING TO NEAR 50 KNOTS OVERNIGHT. VISIBILITIES AS LOW
AS ONE MILE HOWEVER WILL BE POSSIBLE AT TIMES OVERNIGHT AND
CEILINGS ARE EXPECTED TO FALL BACK INTO THE LIFR CATEGORY AFTER
00Z TUESDAY AT GCK AND DDC AND AFTER 03Z AT HYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 33 45 15 28 / 10 10 20 20
GCK 32 42 13 26 / 10 10 30 20
EHA 34 46 15 26 / 10 10 30 20
LBL 33 50 16 27 / 10 10 30 20
HYS 31 41 12 28 / 10 10 30 10
P28 30 49 18 30 / 10 10 30 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...GERARD
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1115 AM CST MON MAR 2 2015
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1112 AM CST MON MAR 2 2015
AT 12Z MONDAY A 500MB TROUGH/LOW WAS JUST OFF THE SOUTHERN
CALIFORNIA COAST WITH A +110KT 250MB JET STREAK LOCATED ON THE
WEST SIDE OF THIS UPPER LEVEL SYSTEM. FURTHER NORTH ANOTHER UPPER
LEVEL TROUGH WAS LOCATED ACROSS SOUTHWEST CANADA. OVER THE CENTRAL
PLAINS A WEST TO SOUTHWESTERLY FLOW WAS PRESENT AT THE 700MB TO
500MB LEVEL. AT THE 850MB LEVEL A WEDGE OF -6C TO -7C TEMPERATURES
WAS LOCATED FROM AMARILLO TO DODGE CITY TO NORTH PLATE. A
SOUTHEASTERLY WIND IN THE SURFACE TO 850MB LEVEL WAS ADVECTING
MORE HUMID AIR BACK INTO PANHANDLE OF TEXAS AND TOWARDS SOUTHWEST
KANSAS. SURFACE OBSERVATIONS INDICATED LOW CLOUDS HAD BEEN
SPREADING INTO SOUTHWEST KANSAS BETWEEN 12Z AND 15Z.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CST MON MAR 2 2015
A STRONG RIDGING UPPER JET WILL INTENSIFY ACROSS THE UPPER MIDWEST
TODAY, INTENSIFYING THE SOUTHWEST FLOW ALOFT ACROSS THE SOUTHERN
ROCKIES INTO THE HIGH PLAINS. ADDITIONALLY A BROAD RIDGE OF SURFACE
HIGH PRESSURE WILL SHIFT EAST OF THE MISSISSIPPI VALLEY TODAY,
CREATING A SURFACE PRESSURE GRADIENT ACROSS THE CENTRAL HIGH PLAINS
AND STRONG SOUTHERLY WINDS. NUMERICAL MODELS ARE INDICATING
IMPRESSIVE BOUNDARY LAYER WARM ADVECTION TODAY AS A RESULT OF THIS
SOUTHERLY RETURN FLOW, HOWEVER THE MAGNITUDE OF WARMUP MAY BE
IMPEDED BY INCREASING STRATUS ACROSS SOUTHWEST KANSAS INTO CENTRAL
KANSAS BY LATE IN THE DAY. ADDITIONALLY THE NMM/ARW AND THE NAM ALL
SHOW SMALL AREAL COVERAGE OF A TRACE TO 0.01" QPF THIS AFTERNOON
ASSOCIATED WITH WARM MOIST ADVECTION. THIS MIGHT INDICATE A SLIGHT
CHANCE FOR PRECIPITATION, HOWEVER THE NAM AND GFS THERMODYNAMIC
MODEL SOUNDINGS INDICATE IMPRESSIVE DRY LAYERS IN THE MID LEVELS
AND NEAR THE GROUND WHICH ARE NOT VERY CONDUCIVE TO GETTING
HYDROMETEORS TO THE SURFACE. PRECIPITATION MAY NOT BE LIKELY
HOWEVER CLOUD COVER WILL INCREASE TODAY. OVERCAST SKIES WILL
LIKELY IMPEDE INSOLATION, KEEPING TEMPERATURES FROM CLIMBING MUCH
ABOVE THE FREEZING POINT ON THE LOWER PLAINS OF CENTRAL KANSAS
HOWEVER, WARMER TEMPERATURES INTO THE 40S MAY BE POSSIBLE IN THE
FAR SOUTHWEST SECTIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 409 AM CST MON MAR 2 2015
A STRONG SHORTWAVE TROUGH DROPPING OUT OF WESTERN CANADA TODAY AND
TONIGHT WILL PHASE WITH THE UPPER LOW/TROUGH SYSTEM THAT HAS BEEN
SITUATED OVER CALIFORNIA AND NEVADA THE PAST FEW DAYS AND MOVE EAST
ACROSS THE NORTHERN AND CENTRAL CONUS THROUGH THE NEXT FEW DAYS.
THIS WILL PUSH A COLD FRONT SOUTH ACROSS WESTERN KANSAS TUESDAY
MORNING. TEMPERATURES MAY ONLY RISE A LITTLE OR HOLD STEADY ACROSS
WEST CENTRAL KANSAS WHERE THE FRONT WILL BE COMING THROUGH EARLIEST
IN THE DAY. LOCATIONS ALONG THE OKLAHOMA BORDER INTO SOUTH CENTRAL
KANSAS COULD SEE TEMPERATURES RISING INTO THE 40S DURING THE MORNING
BEFORE FALLING BACK AFTER THE FRONT MOVES THROUGH. MODEL SOUNDINGS
ARE NOT OVERLY MOIST IMMEDIATELY BEHIND THE FRONT AND SKIES SHOULD
BE PARTLY TO MOSTLY CLOUDY DURING THE DAY.
BY TUESDAY NIGHT THE UPPER TROUGH BEGINS TO MOVE OUT ACROSS THE
CENTRAL PLAINS. WILL CONTINUE TO CARRY THE SLIGHT CHANCE TO CHANCE
POPS DURING THE NIGHT INTO WEDNESDAY MORNING AS MODEL SOUNDINGS
MOISTEN UP SOMEWHAT AND MID LEVEL FRONTOGENETIC FORCING MOVES OVER
THE AREA. PRECIPITATION CHANCES WILL DIMINISH WITH DECREASING CLOUDS
BY WEDNESDAY AFTERNOON AS THE UPPER TROUGH MOVES THROUGH.
THE REMAINDER OF THE WEEK WILL SEE NORTHWEST FLOW ALOFT OVER THE
CENTRAL HIGH PLAINS. THIS WILL RESULT IN DRY WEATHER WITH
TEMPERATURES MODERATING INTO THE 50S FOR THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1112 AM CST MON MAR 2 2015
THE RAP, HRRR AND NAM BUFR SOUNDINGS WERE ALL IN GOOD AGREEMENT
WITH LOW LEVEL MOISTURE INCREASING ACROSS SOUTHWEST KANSAS THIS
AFTERNOON AND OVERNIGHT. AT THIS TIME THE DEPTH OF THIS LOW LEVEL
MOISTURE WILL BE SHALLOW ENOUGH THAT DRIZZLE/FREEZING DRIZZLE WILL
NOT BE AN ISSUE. DENSE FOG ALSO IS NOT ANTICIPATED GIVEN THAT THE
SURFACE WINDS WILL BE AT 15 TO 20 KNOTS AND THE 0-1KM MEAN WINDS
WILL BE INCREASING TO NEAR 50 KNOTS OVERNIGHT. VISIBILITIES AS LOW
AS ONE MILE HOWEVER WILL BE POSSIBLE AT TIMES OVERNIGHT AND
CEILINGS ARE EXPECTED TO FALL BACK INTO THE LIFR CATEGORY AFTER
00Z TUESDAY AT GCK AND DDC AND AFTER 03Z AT HYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 36 32 42 15 / 10 10 10 20
GCK 37 30 38 13 / 10 10 10 30
EHA 41 35 44 15 / 10 10 10 30
LBL 40 30 45 16 / 10 10 10 30
HYS 34 31 37 12 / 10 10 10 30
P28 36 33 46 18 / 10 10 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...RUSSELL
LONG TERM...GERARD
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
405 PM EST MON MAR 2 2015
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL CROSS THE AREA THIS EVENING. HIGH
PRESSURE WILL RIDGE ACROSS THE AREA ON TUESDAY FROM THE WEST.
ANOTHER LOW WILL CROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
SNOW SHOWERS/SQUALLS THIS EVENING AND THEN MUCH COLDER.
WIND CHILLS WILL BE THE MAIN CONCERN OVERNIGHT INTO TUESDAY
MORNING.
20Z SURFACE ANALYSIS SHOWED THE ARCTIC FRONT MAKING ITS WAY SE
ACROSS THE REGION. THE FIRST BATCH OF SNOW SHOWERS/SQUALLS OUT
AHEAD OF THE BOUNDARY THIS AFTERNOON PER THE RADAR. ANOTHER ROUND
SETTING UP AND WILL DIVE SE W/THE UPPER LEVEL SUPPORT EARLY THIS
EVENING. THE LATEST RUN OF THE HRRR 3KM AND RAP MODEL DOING WELL
W/THE PLACEMENT OF THE SNOW MATCHING UP W/THE RADAR TRENDS. LAPSE
RATES ARE STEEPENING ATTM ESPECIALLY FROM 850-700MBS(7.0 C/KM).
THIS COMBINED W/DECENT SHEAR AT 0-3KM OF 35 KTS AND FORECAST CAPE
80+ JOULES WILL BE ENOUGH TO GET SOME MORE SQUALLS GOING. 12Z
UPPER AIR ANALYSIS SUPPORTED THE MODEL SOUNDINGS W/DEEP MOISTURE
THROUGH 700MBS. THE HEAVIEST ACTIVITY WILL RESIDE FROM THE ST.
JOHN VALLEY DOWN THROUGH CARIBOU-PRESQUE ISLE DOWN INTO HOULTON.
ANOTHER AREA OF HEAVY SNOW SHOWERS/SQUALLS IS FORECAST TO DROP
ACROSS PORTIONS OF CENTRAL MAINE INCLUDING THE MILLINOCKET-PATTEN
AREA ALONG ROUTE 11 AND PORTIONS OF I-95. BRIEF HEAVY SNOW BURSTS
W/WIND GUSTS TO 35 MPH WILL LEAD TO BRIEF WHITEOUTS AND VSBY 1/4
OF A MILE OR LESS. CONDITIONS ARE EXPECTED TO IMPROVE LATER THIS
EVENING AS SKIES BEGIN TO CLEAR AND THE FRONT PUSHES TO THE COAST.
WINDS WILL REMAIN UP AT 15 TO 25 MPH SUSTAINED THROUGH THE
OVERNIGHT PERIOD W/GUSTS AT LEAST 30 MPH. THESE WINDS COMBINED
W/THE ARCTIC AIRMASS MOVING IN WILL LEAD TO SOME DANGEROUS WIND
CHILLS ACROSS THE NORTHERN 1/2 OF THE CWA. WIND CHILL ADVISORIES
REMAIN UP FOR NORTHERN AREAS THROUGH TUESDAY MORNING. ATTM, IT
LOOKS LIKE THE CENTRAL HIGHLANDS AND DOWNEAST WILL SEE WIND CHILLS
STAY ABOVE ADVISORY CRITERIA OF -20F.
FOR TUESDAY, HIGH PRES IS FORECAST TO RIDGE ACROSS THE REGION
W/DAYTIME TEMPERATURES BELOW NORMAL FOR EARLY MARCH. CLOUDS WILL
BE ON THE INCREASE LATER IN THE AFTERNOON IN ADVANCE OF THE NEXT
SYSTEM TO AFFECT OUR REGION. THIS IS EXPLAINED MORE IN THE SHORT
TERM SECTION BELOW.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
LOOKING FOR ANOTHER SNOW EVENT TUESDAY NIGHT JUST AHEAD OF A WARM FRONT
MOVING FROM WEST TO EAST THROUGH THE AREA SOUTH OF THE PARENT LOW
PASSING WELL TO OUR NORTH. TEMPERATURES WILL BE RISING THROUGH THE
NIGHT TUESDAY NIGHT, BUT THINK THAT FOR THE VAST MAJORITY OF
AREAS, THIS WILL BE AN ALL SNOW EVENT, PERHAPS ENDING AS JUST A BIT
OF LIGHT RAIN NEAR THE COAST. LOOKING FOR ABOUT 3 TO 5 INCHES OF
SNOW.
AFTER THE WARM FRONT PASSES LATE TUESDAY NIGHT, WE ARE LOOKING FOR
A WARM DAY WEDNESDAY WITH HIGHS ABOVE FREEZING FOR PRETTY MUCH
EVERYWHERE, AND EVEN IN THE LOW 40S DOWNEAST. THE WARMTH IS
SHORT LIVED, HOWEVER, AS THE COLD FRONT MOVES THROUGH LATE
WEDNESDAY. THURSDAY WILL BE MUCH COOLER WITH TEMPERATURES NEAR
STEADY IN THE TEENS TO LOW 20S. THERE MAY BE A FEW SNOW SHOWERS
WITH AND BEHIND THE FRONT LATE WEDNESDAY INTO THURSDAY, BUT
NOTHING MAJOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
LOOK FOR BELOW AVERAGE TEMPERATURES TO PERSIST FRIDAY THROUGH
EARLY NEXT WEEK. WE DO NOT FORESEE ANY MAJOR STORMS, BUT THERE
COULD BE A FEW WEAK ONES BEYOND FRIDAY AFTER WEAK HIGH PRESSURE
OVER THE AREA WEAKENS. TOO MUCH MODEL DISAGREEMENT TO TIME THE
WEAK SYSTEMS THIS FAR OUT.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
NEAR TERM: VFR FOR THE MOST PART FOR ALL TERMINALS INTO TUESDAY.
THE EXCEPTION WILL BE THIS EVENING AS SOME SNOW SQUALLS COULD
BRING CONDITIONS DOWN BRIEFLY TO MVFR/IFR MAINLY FOR THE NORTHERN
TERMINALS.
SHORT TERM: IFR OR WORSE AREAWIDE TUESDAY NIGHT WITH SNOW.
PRECIPITATION TAPERING OFF WEDNESDAY THROUGH THURSDAY WITH
GENERALLY VFR, THOUGH MVFR COULD LINGER IN THE NORTH ESPECIALLY
WEDNESDAY.
&&
.MARINE...
NEAR TERM: GALES ARE STILL EXPECTED THIS EVENING AND OVERNIGHT AS
CAA HITS THE WATERS AND THE PRES GRADIENT TIGHTENS. GUST POTENTIAL
IS POSSIBLE FOR GUSTS TO 40 KTS. WINDS ARE EXPECTED TO DROP BACK
TO SCA LEVELS BY EARLY TUESDAY MORNING. THE SCA LOOKS TO BE SHORT
LIVED AS HIGH PRES RIDGES IN FROM THE SOUTH. SEAS ARE COMING UP
BUT AT LEAST A FOOT UNDER WHAT WAS PREVIOUSLY FORECAST. STAYED
CLOSE TO MIDNIGHT CREW`S ASSESSMENT OF THOSE WAVE HEIGHTS
BUILDING W/A RANGE OF 5 TO 8 FT OVERNIGHT AND THEN COMING DOWN ON
TUESDAY. FREEZING SPRAY WILL BE DEVELOPING LATER THIS EVENING
RIGHT INTO EARLY TUESDAY MORNING W/SOME MODERATE ICE ACCRETION.
SHORT TERM: EXPECT PROLONGED SMALL CRAFT CONDITIONS TUESDAY NIGHT
THROUGH THURSDAY NIGHT. WINDS WILL SHIFT FROM SOUTH TO NORTHWEST
AS A SYSTEM MOVES THROUGH. SEAS WILL PEAK AROUND 9 FEET ON
WEDNESDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL ADVISORY FROM 2 AM TO 7 AM EST TUESDAY FOR
MEZ001>004.
MARINE...FREEZING SPRAY ADVISORY FROM 1 AM TO 10 AM EST TUESDAY FOR
ANZ050>052.
GALE WARNING UNTIL 6 AM EST TUESDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...FOISY
LONG TERM...FOISY
AVIATION...HEWITT/FOISY
MARINE...HEWITT/FOISY
AREA FORECAST DISCUSSION
NWS CARIBOU ME
100 PM EST MON MAR 2 2015
.SYNOPSIS...
LOW PRESSURE SOUTH OF NOVA SCOTIA WILL RAPIDLY MOVE OFF TO THE
THIS AFTERNOON. AN ARCTIC COLD FRONT WILL CROSS THE AREA THIS
EVENING. HIGH PRESSURE WILL BUILD TOWARD THE AREA TONIGHT AND
TUESDAY FROM THE WEST. ANOTHER LOW WILL CROSS THE REGION TUESDAY
NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1245 PM UPDATE...MADE AREAL ADJUSTMENTS TO THE SNOW
SHOWERS/SQUALLS USING THE RADAR & THE LATEST HRRR 3KM MODEL
SHOWING AN AREA SNOW SHOWERS/SQUALLS DEVELOPING ACROSS NORTHERN
AND EASTERN AREAS. A SPECIAL WEATHER STATEMENT WAS ISSUED TO
ACCOUNT FOR THIS ACTIVITY. NAM AND RAP SOUNDINGS STILL INDICATE
STEEPENING LAPSE RATES W/DEEP MOISTURE THROUGH 700MBS. FORECAST
CAPE HAS INCREASE TO 100+ JOULES SINCE THE PREVIOUS RUNS IN THE
HEAVIER ACTIVITY. A QUICK INCH OF SNOW COULD ACCUMULATE W/WIND
GUSTS OF 35 MPH & VBSY 004.
MARINE...FREEZING SPRAY ADVISORY FROM 1 AM TO 10 AM EST TUESDAY FOR
ANZ050>052.
GALE WARNING UNTIL 6 AM EST TUESDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...MIGNONE
LONG TERM...MIGNONE
AVIATION...HEWITT/MIGNONE
MARINE...HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
452 PM EST MON MAR 2 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 451 PM EST MON MAR 2 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW OVER N AMERICA.
FEATURES OF INTEREST FOR THE SHORT TERM FCST ARE A NRN STREAM
SHORTWAVE DROPPING THRU ALBERTA/SASKATCHEWAN AND THE SRN STREAM TROF
OVER CA/NV...IN PARTICULAR THE SHORTWAVE OVER SRN CA/SRN NV WHERE
CONVECTION IS NOTED. THESE TWO WAVES WILL BRING A WIDESPREAD
SYNOPTIC SNOW TO THE AREA TUE. ABUNDANT SUNSHINE HAS BEEN THE RULE
ACROSS THE AREA THIS AFTN UNDER DRY AIR MASS ASSOCIATED WITH SFC
HIGH OVER THE MID MISSISSIPPI VALLEY AND WRN GREAT LAKES REGION.
SUNSHINE WORKING ON THE FORESTED TERRAIN OF UPPER MI HAS RESULTED IN
TEMPS RISING WELL INTO THE 20S OVER MOST OF THE AREA. COOLEST
CONDITIONS (AROUND 20F) ARE OVER THE FAR E...CLOSER TO THE DEPARTING
850MB THERMAL TROF...AND AT MANY LOCATIONS ALONG LAKE SUPERIOR WHERE
LAKE/ICE BREEZE HAS DEVELOPED.
LATEST MODEL RUNS CONTINUE TO SHOW THE 2 AFOREMENTIONED SHORTWAVES
REMAINING UNPHASED AS THEY AFFECT THE AREA TUE. THE SRN WAVE WILL
ACCELERATE OUT OF THE SW INTO THE DOWNSTREAM CONFLUENT FLOW...AND IT
WILL BE THE DRIVER OF THE SNOW THAT SPREADS INTO THE UPPER LAKES. IT
APPEARS 1 MAIN STREAK OF PCPN OR AT LEAST MORE ORGANIZED/HEAVIER
PCPN WILL DEVELOP TONIGHT TO THE SW. THIS PCPN WILL STREAK NE ACROSS
SD INTO CNTRL MN IN ASSOCIATION WITH A COUPLED UPPER JET
STRUCTURE/ENHANCED UPPER DIVERGENCE FROM LEFT EXIT OF 150KT JET
TRANSLATING OUT OF THE SRN ROCKIES AND THE RIGHT ENTRANCE OF 125KT
JET STREAK OVER ND INTO NRN ONTARIO. MORE PCPN WILL BEGIN TO GET
ORGANIZED FARTHER E LATE IN THE NIGHT AS MID LEVEL FRONTOGENESIS AND
BROADER WAA/ISENTROPIC ASCENT BEGIN TO SATURATE DRIER AIR AT THE
LOWER LEVELS. MODELS ARE NEARLY IDENTICAL IN TIMING THE PCPN INTO
WRN AND SRN UPPER MI IN THE 08-12Z TIME FRAME...AND STARTING ACROSS
THE N AND E AROUND OR SHORTLY AFTER 12Z. SO...LITTLE ADJUSTMENT WILL
BE REQUIRED WITH ONSET TIMING. ACCUMULATIONS AROUND ONE HALF INCH
MAY OCCUR ALONG THE WI BORDER BY 12Z.
ON TUE...THE BEST UPPER DIVERGENCE ASSOCIATED WITH A WEAKENING
COUPLED UPPER JET STRUCTURE QUICKLY SHIFTS NE ACROSS NE MN/WRN LAKE
SUPERIOR INTO NRN ONTARIO. MEANWHILE...WAA/ISENTROPIC
ASCENT/FRONTOGENETICALLY FORCED PCPN WILL QUICKLY EXPAND/INCREASE IN
INTENSITY AS AIR MASS SATURATES AND DEEP LAYER FORCING PROVIDED BY
SHORTWAVE ARRIVES. ON THE 285K SFC (ROUGHLY 700-750MB)...MIXING
RATIOS AROUND 2.5G/KG ARE AVBL...SUGGESTING SOMETHING AROUND 3
INCHES OF SNOW FOR 6-9HRS OF ASCENT. HOWEVER...GIVEN THE OTHER
FACTORS AT PLAY...A WIDESPREAD FAIRLY UNIFORM 3-5 INCH SNOW IS
EXPECTED ACROSS THE ENTIRE FCST AREA TUE...WHICH FALLS NICELY INLINE
WITH THE CONSENSUS QPF NUMBERS FROM THE MODELS CONVERTED TO SNOW
USING A 15 TO 1 OR SO SNOW RATIO. WITH SOUTHERLY LOW-LEVEL FLOW UP
LAKE MICHIGAN FOR SEVERAL HRS AND AIR MASS JUST COLD ENOUGH TO
SUPPORT ENHANCEMENT...THERE SHOULD BE SOME BOOST TO SNOW TOTALS
DOWNWIND OF LAKE MICHIGAN THOUGH ICE COVER WILL LIMIT THE
ENHANCEMENT OVER WHAT IT COULD BE. THAT AREA IS MORE LIKELY TO SEE
ACCUMULATIONS CLOSER TO 5 INCHES THAN 3...AND NOT OUT OF THE
QUESTION THAT SOME 6 INCH AMOUNTS COULD OCCUR. FORCING QUICKLY
SHIFTS E TUE AFTN...RESULTING IN SNOW RAPIDLY DIMINISHING W TO E
DURING THE MID AND LATE AFTN HRS. IN FACT...IT MAY END COMPLETELY
OVER PORTIONS OF THE WEST LATE IN THE AFTN. WITH SNOW RATIO LIKELY
UNDER 20 TO 1...THIS SYSTEM WILL ACHIEVE THE WETTER SNOW TYPE ADVY
CRITERIA OF AN AVG SNOWFALL OF AT LEAST 3IN/12HR OVER THE ENTIRE
FCST AREA. SO...ADVY WILL BE HOISTED ACROSS THE BOARD.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 402 PM EST MON MAR 2 2015
AT THE START OF THE LONG TERM PERIOD...UPPER MICHIGAN WILL SEE THE
SYNOPTIC PRECIPITATION QUICKLY COMING TO AN END OVER THE EASTERN
THIRD OF THE CWA. THIS IS DUE TO THE DRY MID LEVEL AIR MOVING OVER
THE AREA BEHIND THE COLD FRONT AND AHEAD OF THE MAIN SHORTWAVE
TROUGH THAT WILL MOVE THROUGH ON TUESDAY. THEN...AS COLDER AIR
SURGES INTO THE AREA...GENERALLY AFTER MIDNIGHT TUESDAY
NIGHT...SHOULD SEE THE POTENTIAL FOR LAKE EFFECT INCREASE FROM WEST
TO EAST. 850MB TEMPS WILL FALL FROM AROUND -11C AT 00Z WEDNESDAY
TO -26C AT 18Z WEDNESDAY...PROVIDING PLENTY OF OVER LAKE
INSTABILITY WHERE THERE IS OPEN WATER. THAT IS THE BIG QUESTION FOR
THE LAKE EFFECT FORECAST. VISIBLE SATELLITE SHOWS SEVERAL LARGER
AREAS OF OPEN WATER AND SLUSH OVER WESTERN...NORTH CENTRAL...AND
SOUTH CENTRAL LAKE SUPERIOR. THOSE AREAS HAVE NOT BEEN REPRESENTED
IN THE MODELS AT THIS POINT...SO I DON/T FEEL THE MODELS ARE
INDICATING THE LAKE EFFECT POTENTIAL IN THE QPF FIELDS.
THUS...HAVE PERFORMED SIGNIFICANT HAND EDITS TO THE GRIDS...BOTH IN
RAISING POPS AND HIGHLIGHTING AREAS DOWNWIND OF THE CURRENT OPEN
WATER AREAS. WITH THE STRONG WEST TO WEST-NORTHWEST WINDS TUESDAY
NIGHT INTO WEDNESDAY...THOSE AREAS OF OPEN WATER WILL LIKELY EXPAND
AND MOVE...SO THAT DOES INCREASE THE UNCERTAINTY OF THE LAKE EFFECT
SOME...BUT EVEN WITH THE COLD AIR...THINK THE WINDS WILL LIMIT THE
ICE COVER EXPANDING AT LEAST THROUGH WEDNESDAY. WHILE THE LAKE
EFFECT WON/T BE TOO STRONG INITIALLY TUESDAY NIGHT...THE CLOUD WILL
BE WITHIN THE DGZ AND LEAD TO A FLUFFY INCH OR SO OF ACCUMULATION.
THEN ON WEDNESDAY...INVERSION HEIGHTS WILL RISE TO 7-9KFT AS A
SHORTWAVE MOVES THROUGH AND SUPPORT MODERATE TO POTENTIALLY EVEN
LOCALLY HEAVY SNOWFALL. WITH THE COLD AIR BEING IN PLACE ON
WEDNESDAY...SNOWFLAKE SIZE SHOULD BE SMALL AND KEEP ACCUMULATIONS
IN THE COUPLE INCH RANGE FOR THE WEST-NORTHWEST WIND AREAS DOWNWIND
OF THE OPEN WATER. IN ADDITION...RECENT SNOWFALL AND THE STRONG
WINDS WILL LIKELY LEAD TO PATCHY/AREAS OF BLOWING SNOW...ESPECIALLY
OVER THE KEWEENAW AND NEAR LAKE SUPERIOR EAST OF MARQUETTE. WHEN
COMBINED WITH THE FINE FLAKED LAKE EFFECT SNOW...THIS WILL LEAD TO
VISIBILITIES BEING REDUCED BELOW 1 MILE AND IN THE STRONGER BANDS
LIKELY BELOW 1/2MI. FORTUNATELY...WITH WINDS MORE OUT OF THE WEST TO
WEST-NORTHWEST...THE IMPACT FOR AREAS EAST OF MARQUETTE WILL BE
FOCUSED MORE IN THE AREAS TO THE EAST OF MUNISING AND GENERALLY LESS
POPULATED AREAS.
HIGH PRESSURE RIDGE WILL BEGIN TO MOVE INTO THE AREA WEDNESDAY
NIGHT...DECREASING WINDS AND INCREASING SUBSIDENCE (LOWERING
INVERSION HEIGHTS). A WEAK SURFACE TROUGH MOVING OVER EASTERN LAKE
SUPERIOR AROUND MIDNIGHT WILL SHIFT WINDS MORE TO THE NORTHWEST FOR
A BRIEF PERIOD OF TIME BEFORE BACKING BACK TO THE WEST BY THURSDAY
AFTERNOON. WILL SHOW A GRADUALLY DECREASING TREND TO THE POPS FOR
THAT TIME PERIOD WHILE FOLLOWING THE WIND DIRECTIONS.
SHOULD SEE TEMPERATURES MODERATING BOTH ALOFT AND AT THE SURFACE
FRIDAY THROUGH THE WEEKEND AS 500MB FLOW BEGINS TO TURN A LITTLE
MORE WEST-NORTHWESTERLY. THIS SHOULD LEAD TO TEMPERATURES WARMING
TOWARDS MORE NORMAL VALUES FOR THIS TIME OF YEAR (INTO THE LOWER
30S). BUT THE CONFIDENCE ON PRECIPITATION OCCURRENCE IS LOW DUE TO
DIFFERENCES IN THE WAY THE MODELS HANDLE A COUPLE WAVES COMING ON
SHORE IN NORTHERN BRITISH COLUMBIA. THE 12Z GFS/GEM SLIDE THE WAVES
SOUTHEAST THROUGH THE AREA LATE FRIDAY NIGHT INTO SATURDAY...WITH
ANOTHER ONE ARRIVING ON SUNDAY. MEANWHILE...THE 12Z ECMWF SHOWS THE
WAVES BECOMING SEPARATED AND SPLITTING THE CWA THROUGH THE WEEKEND.
EITHER WAY WITH THE LIMITED DEEP MOISTURE...WOULDN/T EXPECT MUCH
MORE THAN LIGHT PRECIP ACCUMULATION THROUGH THE WEEKEND AND WILL
ONLY MENTION SLIGHT CHANCES.
A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH THE AREA SUNDAY NIGHT
INTO MONDAY...LIKELY PULLING IN THE LAST SURGE OF COLD AIR FOR A
WHILE THROUGH THE AREA. EXPECT THERE TO BE SOME PRECIP ASSOCIATED
WITH THE SHORTWAVE...BUT THEN WITH WINDS TURNING NORTHERLY BETWEEN
THE DEPARTING SURFACE TROUGH AND A HIGH IN THE DAKOTAS...SHOULD SEE
A PERIOD OF LAKE EFFECT IN THE NORMAL SNOW BELTS. WITH THE FAVORABLE
850MB TEMPS (AROUND -14 TO -18C MONDAY)...WILL TREND POPS UP TO
MID/HIGH END CHANCES FOR NOW UNTIL WE ARE ABLE TO GET A BETTER
HANDLE ON THE ICE SITUATION ON LAKE SUPERIOR.
BEHIND THIS WAVE...GFS/ECMWF DETERMINISTIC AND ENSEMBLE MEMBERS ARE
SHOWING THE RIDGE THAT HAS BEEN PERSISTENT OVER THE WESTERN CONUS
AND ALASKA FOR THE LAST MONTH TO SHIFT EAST INTO THE CENTRAL CONUS
AROUND THE MIDDLE OF NEXT WEEK. THIS WILL LEAD TO TEMPERATURES
WARMING TO ABOVE NORMAL VALUES AND START MELTING SOME OF THE
SNOWPACK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1240 PM EST MON MAR 2 2015
VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THIS AFTN/EVENING
UNDER DRY AIR MASS ASSOCIATED WITH HIGH PRES MOVING FROM THE MID
MISSISSIPPI VALLEY TO THE MID ATLANTIC STATES. LATE TONIGHT...SW
FLOW BTWN THE HIGH AND AN APPROACHING LOW PRES TROF WILL BRING A
RAPID INCREASE IN MOISTURE WHICH WILL LEAD TO SNOW DEVELOPMENT. AS
THE SNOW SPREADS NE...MVFR CONDITIONS SHOULD DEVELOP AT KIWD AROUND
09Z AND AT KCMX/KSAW AROUND 12Z. BY MID TO LATE MORNING...ALL
TERMINALS SHOULD SEE IFR CONDITIONS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 451 PM EST MON MAR 2 2015
GENERALLY LIGHT WINDS CURRENTLY ACROSS LAKE SUPERIOR WILL BECOME S
AND RAMP UP TONIGHT AND TUE TO 15-25KT IN ADVANCE OF AN APPROACHING
LO PRES TROF. ONCE THE TROF PASSES TO THE E TUE NIGHT...TIGHTENING
PRES GRADIENT AND STRONG COLD AIR ADVECTION AHEAD OF ARCTIC HIGH
PRES MOVING INTO THE NORTHERN PLAINS WILL LIKELY BRING A PERIOD OF
NW GALES INTO WED...MAINLY ACROSS CNTRL AND ERN LAKE SUPERIOR. AFTER
WED...NO GALE FORCE WINDS ARE EXPECTED THRU THE REMAINDER OF THE
WEEK. LATEST OFFICIAL ICE CONCENTRATION ON LAKE SUPERIOR IS AROUND
94 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK...THE HIGHER ICE
COVERAGE SHOULD PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 AM EST /6 AM CST/ TO 7 PM EST /6
PM CST/ TUESDAY FOR MIZ001>007-009>014-084-085.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING FOR
LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
402 PM EST MON MAR 2 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM EST MON MAR 2 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW OVER
NAMERICA WITH ARCTIC BRANCH TROF EXTENDING FM HUDSON BAY INTO THE
GREAT LKS. SHRTWV/AREA OF SOME LO/MID CLDS ASSOCIATED WITH SOME MSTR
BTWN H9 AND H7 SHOWN ON THE 00Z INL RAOB ARE PASSING THRU UPR MI
EARLY THIS MRNG. IN CONCERT WITH THE COLD NW LLVL FLOW E OF HI PRES
RDG SHIFTING INTO MN THAT IS ADVECTING H85 TEMPS AS LO AS -18C TO
-19C INTO THE AREA...SOME SCATTERED SN SHOWERS ARE IMPACTING UPR MI
DESPITE EXTENSIVE ICE COVER ON LK SUP. THE MOST NMRS SN SHOWERS
APPEAR TO BE OVER THE W TO THE S OF HOUGHTON AND OVER ALGER
COUNTY...LOCATIONS THAT ARE DOWNWIND OF WIDER BREAKS IN THE ICE
COVER OVER WRN LK SUP NEAR THE MN ARROWHEAD/E OF THE BAYFIELD
PENINSULA AND OVER AN AREA TO THE E OF THE KEWEENAW. LOOKING TO THE
NW...THERE IS A SHRTWV RDG WITHIN THE ARCTIC BRANCH MOVING E OVER
SCENTRAL CANADA SUPPORTING THE SFC HI MOVING INTO MN. 12HR H5 HGT
RISES UP TO 100-120M HAVE BEEN OBSVD UNDER THE NVA AHEAD OF THIS
FEATURE. WITHIN THE SRN BRANCH...THERE IS A CUTOFF LO MOVING OFF THE
PACIFIC INTO SRN CA.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS INTO THIS MRNG
AND THEN ANTICIPATED CLRG WITH APRCH OF SHRTWV RDG/SFC HI PRES.
FOCUS FOR LATER TNGT WL SHIFT TOWARD POPS ASSOCIATED WITH DVLPG WAA
BTWN SFC HI PRES SHIFTING TO THE E AND FALLING MSLP TO THE W IN
ADVANCE OF SRN BRANCH SHRTWV LIFTING INTO THE PLAINS AND DEEPENING
ARCTIC BRANCH TROF INTO THE NRN PLAINS.
TODAY...WITH APRCH OF SHRTWV RDG AXIS/SFC HI PRES THIS MRNG...
MODELS SHOW H5 HGT RISES UP TO 180M BTWN 06Z-18Z. SHARPENING/
LOWERING SUBSIDENCE INVRN TO AOB 3K FT AGL AND INCRSGLY ACYC H925
FLOW SHOULD RESULT IN STEADY DIMINISHING TREND TO THE LES W-E WITH
ACTIVITY OVER THE E ENDING BY NOON. AS SKIES TURN MOSUNNY THIS AFTN
WITH RDG AXIS SHIFTING E ACRS THE CWA...EXPECT TEMPS TO TOP OUT IN
THE 20S WITH MIXING TO H85-875.
TNGT...AS SHRTWV RDG EXITS TO THE E...SFC HI PRES IS FCST TO DRIFT
INTO NEW ENGLAND. INCRSG SW FLOW BTWN THE DEPARTING HI AND FALLING
MSLP FM NW ONTARIO THRU THE PLAINS IN ADVANCE OF DIGGING SHRTWV THAT
WL BE DEEPENING THE ARCTIC BRANCH TROF IN SCENTRAL CANADA AND SHRTWV
LIFTING NE INTO THE PLAINS FM SRN BRANCH CUTOFF LO NOW OVER SRN CA
WILL BRING WAA/ISENTROPIC ASCENT BACK TO THE UPR LKS. THE MAJORITY
OF THE MODELS SHOW A BAND OF LGT PCPN UP TO 0.05 TO 0.10 INCH BY 12Z
NEAR THE WI BORDER WELL TO THE N OF H85 WARM FNT ASSOCIATED WITH SRN
BRANCH LO PRES CENTER FCST TO TAKE SHAPE IN THE CENTRAL PLAINS. THIS
BAND OF PCPN APPEARS TO BE RELATED TO HIER LVL FGEN IN THE H7-5 LYR
AND MID LVL MOISTENING WITH H7 SPECIFIC HUMIDITY FCST TO INCRS UP TO
2 G/KG BY 12Z. BUT POPS/PCPN AMNTS WL BE LIMITED BY LINGERING LOWER
LVL DRY AIR AS WELL AS PRESENCE OF SHARPER DEEP LYR QVECTOR STILL
FARTHER TO THE SW. GIVEN THE LINGERING LLVL DRY AIR AND FCST SHARPER
DYNAMIC SUPPORT/H85 WARM FNT/ISENTROPIC ASCENT TO THE SW...WENT NO
HIER THAN HI CHC POPS LATE NEAR THE WI BORDER ATTM. EXPECT THE
LOWEST MIN TEMPS OVER THE E CLOSER TO RETREATING HI PRES/CORE OF
DRIER AIR.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 402 PM EST MON MAR 2 2015
AT THE START OF THE LONG TERM PERIOD...UPPER MICHIGAN WILL SEE THE
SYNOPTIC PRECIPITATION QUICKLY COMING TO AN END OVER THE EASTERN
THIRD OF THE CWA. THIS IS DUE TO THE DRY MID LEVEL AIR MOVING OVER
THE AREA BEHIND THE COLD FRONT AND AHEAD OF THE MAIN SHORTWAVE
TROUGH THAT WILL MOVE THROUGH ON TUESDAY. THEN...AS COLDER AIR
SURGES INTO THE AREA...GENERALLY AFTER MIDNIGHT TUESDAY
NIGHT...SHOULD SEE THE POTENTIAL FOR LAKE EFFECT INCREASE FROM WEST
TO EAST. 850MB TEMPS WILL FALL FROM AROUND -11C AT 00Z WEDNESDAY
TO -26C AT 18Z WEDNESDAY...PROVIDING PLENTY OF OVER LAKE
INSTABILITY WHERE THERE IS OPEN WATER. THAT IS THE BIG QUESTION FOR
THE LAKE EFFECT FORECAST. VISIBLE SATELLITE SHOWS SEVERAL LARGER
AREAS OF OPEN WATER AND SLUSH OVER WESTERN...NORTH CENTRAL...AND
SOUTH CENTRAL LAKE SUPERIOR. THOSE AREAS HAVE NOT BEEN REPRESENTED
IN THE MODELS AT THIS POINT...SO I DON/T FEEL THE MODELS ARE
INDICATING THE LAKE EFFECT POTENTIAL IN THE QPF FIELDS.
THUS...HAVE PERFORMED SIGNIFICANT HAND EDITS TO THE GRIDS...BOTH IN
RAISING POPS AND HIGHLIGHTING AREAS DOWNWIND OF THE CURRENT OPEN
WATER AREAS. WITH THE STRONG WEST TO WEST-NORTHWEST WINDS TUESDAY
NIGHT INTO WEDNESDAY...THOSE AREAS OF OPEN WATER WILL LIKELY EXPAND
AND MOVE...SO THAT DOES INCREASE THE UNCERTAINTY OF THE LAKE EFFECT
SOME...BUT EVEN WITH THE COLD AIR...THINK THE WINDS WILL LIMIT THE
ICE COVER EXPANDING AT LEAST THROUGH WEDNESDAY. WHILE THE LAKE
EFFECT WON/T BE TOO STRONG INITIALLY TUESDAY NIGHT...THE CLOUD WILL
BE WITHIN THE DGZ AND LEAD TO A FLUFFY INCH OR SO OF ACCUMULATION.
THEN ON WEDNESDAY...INVERSION HEIGHTS WILL RISE TO 7-9KFT AS A
SHORTWAVE MOVES THROUGH AND SUPPORT MODERATE TO POTENTIALLY EVEN
LOCALLY HEAVY SNOWFALL. WITH THE COLD AIR BEING IN PLACE ON
WEDNESDAY...SNOWFLAKE SIZE SHOULD BE SMALL AND KEEP ACCUMULATIONS
IN THE COUPLE INCH RANGE FOR THE WEST-NORTHWEST WIND AREAS DOWNWIND
OF THE OPEN WATER. IN ADDITION...RECENT SNOWFALL AND THE STRONG
WINDS WILL LIKELY LEAD TO PATCHY/AREAS OF BLOWING SNOW...ESPECIALLY
OVER THE KEWEENAW AND NEAR LAKE SUPERIOR EAST OF MARQUETTE. WHEN
COMBINED WITH THE FINE FLAKED LAKE EFFECT SNOW...THIS WILL LEAD TO
VISIBILITIES BEING REDUCED BELOW 1 MILE AND IN THE STRONGER BANDS
LIKELY BELOW 1/2MI. FORTUNATELY...WITH WINDS MORE OUT OF THE WEST TO
WEST-NORTHWEST...THE IMPACT FOR AREAS EAST OF MARQUETTE WILL BE
FOCUSED MORE IN THE AREAS TO THE EAST OF MUNISING AND GENERALLY LESS
POPULATED AREAS.
HIGH PRESSURE RIDGE WILL BEGIN TO MOVE INTO THE AREA WEDNESDAY
NIGHT...DECREASING WINDS AND INCREASING SUBSIDENCE (LOWERING
INVERSION HEIGHTS). A WEAK SURFACE TROUGH MOVING OVER EASTERN LAKE
SUPERIOR AROUND MIDNIGHT WILL SHIFT WINDS MORE TO THE NORTHWEST FOR
A BRIEF PERIOD OF TIME BEFORE BACKING BACK TO THE WEST BY THURSDAY
AFTERNOON. WILL SHOW A GRADUALLY DECREASING TREND TO THE POPS FOR
THAT TIME PERIOD WHILE FOLLOWING THE WIND DIRECTIONS.
SHOULD SEE TEMPERATURES MODERATING BOTH ALOFT AND AT THE SURFACE
FRIDAY THROUGH THE WEEKEND AS 500MB FLOW BEGINS TO TURN A LITTLE
MORE WEST-NORTHWESTERLY. THIS SHOULD LEAD TO TEMPERATURES WARMING
TOWARDS MORE NORMAL VALUES FOR THIS TIME OF YEAR (INTO THE LOWER
30S). BUT THE CONFIDENCE ON PRECIPITATION OCCURRENCE IS LOW DUE TO
DIFFERENCES IN THE WAY THE MODELS HANDLE A COUPLE WAVES COMING ON
SHORE IN NORTHERN BRITISH COLUMBIA. THE 12Z GFS/GEM SLIDE THE WAVES
SOUTHEAST THROUGH THE AREA LATE FRIDAY NIGHT INTO SATURDAY...WITH
ANOTHER ONE ARRIVING ON SUNDAY. MEANWHILE...THE 12Z ECMWF SHOWS THE
WAVES BECOMING SEPARATED AND SPLITTING THE CWA THROUGH THE WEEKEND.
EITHER WAY WITH THE LIMITED DEEP MOISTURE...WOULDN/T EXPECT MUCH
MORE THAN LIGHT PRECIP ACCUMULATION THROUGH THE WEEKEND AND WILL
ONLY MENTION SLIGHT CHANCES.
A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH THE AREA SUNDAY NIGHT
INTO MONDAY...LIKELY PULLING IN THE LAST SURGE OF COLD AIR FOR A
WHILE THROUGH THE AREA. EXPECT THERE TO BE SOME PRECIP ASSOCIATED
WITH THE SHORTWAVE...BUT THEN WITH WINDS TURNING NORTHERLY BETWEEN
THE DEPARTING SURFACE TROUGH AND A HIGH IN THE DAKOTAS...SHOULD SEE
A PERIOD OF LAKE EFFECT IN THE NORMAL SNOW BELTS. WITH THE FAVORABLE
850MB TEMPS (AROUND -14 TO -18C MONDAY)...WILL TREND POPS UP TO
MID/HIGH END CHANCES FOR NOW UNTIL WE ARE ABLE TO GET A BETTER
HANDLE ON THE ICE SITUATION ON LAKE SUPERIOR.
BEHIND THIS WAVE...GFS/ECMWF DETERMINISTIC AND ENSEMBLE MEMBERS ARE
SHOWING THE RIDGE THAT HAS BEEN PERSISTENT OVER THE WESTERN CONUS
AND ALASKA FOR THE LAST MONTH TO SHIFT EAST INTO THE CENTRAL CONUS
AROUND THE MIDDLE OF NEXT WEEK. THIS WILL LEAD TO TEMPERATURES
WARMING TO ABOVE NORMAL VALUES AND START MELTING SOME OF THE
SNOWPACK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1240 PM EST MON MAR 2 2015
VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THIS AFTN/EVENING
UNDER DRY AIR MASS ASSOCIATED WITH HIGH PRES MOVING FROM THE MID
MISSISSIPPI VALLEY TO THE MID ATLANTIC STATES. LATE TONIGHT...SW
FLOW BTWN THE HIGH AND AN APPROACHING LOW PRES TROF WILL BRING A
RAPID INCREASE IN MOISTURE WHICH WILL LEAD TO SNOW DEVELOPMENT. AS
THE SNOW SPREADS NE...MVFR CONDITIONS SHOULD DEVELOP AT KIWD AROUND
09Z AND AT KCMX/KSAW AROUND 12Z. BY MID TO LATE MORNING...ALL
TERMINALS SHOULD SEE IFR CONDITIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EST MON MAR 2 2015
NW WINDS UP TO 30 KTS OVER EASTERN LAKE SUPERIOR EARLY WILL DIMINISH
QUICKLY THIS MORNING WITH ARRIVAL OF HI PRES RIDGE. LIGHT S WINDS
WILL THEN INCREASE UP TO 25 KTS ON TUE IN ADVANCE AN APPROACHING LO
PRES. ONCE THE LO PASSES TO THE E ON TUE NIGHT...TIGHTENING PRES
GRADIENT AND STRONG COLD AIR ADVECTION AHEAD OF ARCTIC HI PRES
MOVING INTO THE NORTHERN PLAINS WILL LIKELY BRING A PERIOD OF NW
GALES INTO WED. LATEST OFFICIAL ICE CONCENTRATION ON LK SUPERIOR IS
AROUND 95 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK...EXPECT
THE HIGHER ICE COVERAGE TO PERSIST AS TEMPERATURES STAY BELOW
FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 AM EST /6 AM CST/ TO 7 PM EST /6
PM CST/ TUESDAY FOR MIZ001>007-009>014-084-085.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING FOR
LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1240 PM EST MON MAR 2 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM EST MON MAR 2 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW OVER
NAMERICA WITH ARCTIC BRANCH TROF EXTENDING FM HUDSON BAY INTO THE
GREAT LKS. SHRTWV/AREA OF SOME LO/MID CLDS ASSOCIATED WITH SOME MSTR
BTWN H9 AND H7 SHOWN ON THE 00Z INL RAOB ARE PASSING THRU UPR MI
EARLY THIS MRNG. IN CONCERT WITH THE COLD NW LLVL FLOW E OF HI PRES
RDG SHIFTING INTO MN THAT IS ADVECTING H85 TEMPS AS LO AS -18C TO
-19C INTO THE AREA...SOME SCATTERED SN SHOWERS ARE IMPACTING UPR MI
DESPITE EXTENSIVE ICE COVER ON LK SUP. THE MOST NMRS SN SHOWERS
APPEAR TO BE OVER THE W TO THE S OF HOUGHTON AND OVER ALGER
COUNTY...LOCATIONS THAT ARE DOWNWIND OF WIDER BREAKS IN THE ICE
COVER OVER WRN LK SUP NEAR THE MN ARROWHEAD/E OF THE BAYFIELD
PENINSULA AND OVER AN AREA TO THE E OF THE KEWEENAW. LOOKING TO THE
NW...THERE IS A SHRTWV RDG WITHIN THE ARCTIC BRANCH MOVING E OVER
SCENTRAL CANADA SUPPORTING THE SFC HI MOVING INTO MN. 12HR H5 HGT
RISES UP TO 100-120M HAVE BEEN OBSVD UNDER THE NVA AHEAD OF THIS
FEATURE. WITHIN THE SRN BRANCH...THERE IS A CUTOFF LO MOVING OFF THE
PACIFIC INTO SRN CA.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS INTO THIS MRNG
AND THEN ANTICIPATED CLRG WITH APRCH OF SHRTWV RDG/SFC HI PRES.
FOCUS FOR LATER TNGT WL SHIFT TOWARD POPS ASSOCIATED WITH DVLPG WAA
BTWN SFC HI PRES SHIFTING TO THE E AND FALLING MSLP TO THE W IN
ADVANCE OF SRN BRANCH SHRTWV LIFTING INTO THE PLAINS AND DEEPENING
ARCTIC BRANCH TROF INTO THE NRN PLAINS.
TODAY...WITH APRCH OF SHRTWV RDG AXIS/SFC HI PRES THIS MRNG...
MODELS SHOW H5 HGT RISES UP TO 180M BTWN 06Z-18Z. SHARPENING/
LOWERING SUBSIDENCE INVRN TO AOB 3K FT AGL AND INCRSGLY ACYC H925
FLOW SHOULD RESULT IN STEADY DIMINISHING TREND TO THE LES W-E WITH
ACTIVITY OVER THE E ENDING BY NOON. AS SKIES TURN MOSUNNY THIS AFTN
WITH RDG AXIS SHIFTING E ACRS THE CWA...EXPECT TEMPS TO TOP OUT IN
THE 20S WITH MIXING TO H85-875.
TNGT...AS SHRTWV RDG EXITS TO THE E...SFC HI PRES IS FCST TO DRIFT
INTO NEW ENGLAND. INCRSG SW FLOW BTWN THE DEPARTING HI AND FALLING
MSLP FM NW ONTARIO THRU THE PLAINS IN ADVANCE OF DIGGING SHRTWV THAT
WL BE DEEPENING THE ARCTIC BRANCH TROF IN SCENTRAL CANADA AND SHRTWV
LIFTING NE INTO THE PLAINS FM SRN BRANCH CUTOFF LO NOW OVER SRN CA
WILL BRING WAA/ISENTROPIC ASCENT BACK TO THE UPR LKS. THE MAJORITY
OF THE MODELS SHOW A BAND OF LGT PCPN UP TO 0.05 TO 0.10 INCH BY 12Z
NEAR THE WI BORDER WELL TO THE N OF H85 WARM FNT ASSOCIATED WITH SRN
BRANCH LO PRES CENTER FCST TO TAKE SHAPE IN THE CENTRAL PLAINS. THIS
BAND OF PCPN APPEARS TO BE RELATED TO HIER LVL FGEN IN THE H7-5 LYR
AND MID LVL MOISTENING WITH H7 SPECIFIC HUMIDITY FCST TO INCRS UP TO
2 G/KG BY 12Z. BUT POPS/PCPN AMNTS WL BE LIMITED BY LINGERING LOWER
LVL DRY AIR AS WELL AS PRESENCE OF SHARPER DEEP LYR QVECTOR STILL
FARTHER TO THE SW. GIVEN THE LINGERING LLVL DRY AIR AND FCST SHARPER
DYNAMIC SUPPORT/H85 WARM FNT/ISENTROPIC ASCENT TO THE SW...WENT NO
HIER THAN HI CHC POPS LATE NEAR THE WI BORDER ATTM. EXPECT THE
LOWEST MIN TEMPS OVER THE E CLOSER TO RETREATING HI PRES/CORE OF
DRIER AIR.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 331 AM EST MON MAR 2 2015
PRIMARY IMPACT IN THE LONG TERM WILL BE TUE AS MODERATE SNOW MOVES
THROUGH THE AREA.
AT 12Z TUE A NRN STREAM SYSTEM WILL BE OVER NRN MANITOBA WHILE A SRN
STREAM SYSTEM IS OVER THE CENTRAL PLAINS. LIGHT SNOW SHOULD BE
ONGOING LATE MON NIGHT INTO TUE MORNING...MAINLY OVER THE SRN/SWRN
CWA. SRN STREAM ENERGY STAYS MAINLY S OF THE CWA ON TUE AS THE NRN
STREAM SYSTEM MOVES INTO FAR NRN ONTARIO. GENERALLY MODERATE SNOW
WILL FALL ACROSS MOST OF THE REGION IN THE BROAD AREA OF
WAA/ISENTROPIC ASCENT ALONG WITH LARGER SCALE FORCING AS THE TROUGH
MOVES IN FROM THE W. SNOW RATIOS SHOULD BE BETWEEN 15-1 AND 18-1
AS TEMP PROFILES DO NOT SHOW THE DGZ BEING PARTICULARLY DEEP...BUT
DEEP ENOUGH TO KEEP RATIOS FROM BEING AS LOW AS 10-1. GENERALLY
PREFER A BLEND OF MODEL QPF FROM THE 00Z/02 GFS...12Z/01
ECMWF...00Z/02 NAM/NAM DNG...00Z/02 REGIONAL GEM AND 00Z/02 CONSALL.
THESE MODELS ARE IN GENERAL AGREEMENT ON QPF AMOUNTS...BUT THERE IS
STILL SOME DIFFERENCES...LIKELY DUE TO CHALLENGES OF SYSTEM PHASING.
PREFERRED MODEL BLEND GIVES QPF AMOUNTS OF 0.20-0.28
INCHES...RESULTING IN SNOWFALL AMOUNTS RANGING FROM AROUND 2.5
INCHES SCENTRAL TO 3-5 INCHES ELSEWHERE. LOOKING AT THE HIGHER END
OF PREFERRED GUIDANCE...QPF AMOUNTS UP TO 0.35 INCHES ARE NOT OUT OF
THE QUESTION...WHICH WOULD ALLOW FOR QPF AMOUNTS UP TO 5-6 INCHES.
THE LOW END OF PREFERRED GUIDANCE WOULD RESULT IN 2-3.5 INCHES OF
SNOW. LOOKING LIKE AN ADVISORY WILL BE NEEDED FOR TUE AS MOST OF THE
SNOW FALLS IN LESS THAN 12 HOURS DURING THE DAY AND CRITERIA IS 3-6
INCHES. WILL ALLOW THE DAY SHIFT TO TAKE ANOTHER LOOK AT THINGS
GIVEN VARIABILITY OF EXACT AMOUNTS AND PLACEMENT DUE TO COMPLEXITIES
OF SYSTEM PHASING.
WITH 850MB TEMPS AS WARM AS -9C ON TUE...SFC HIGH TEMPS WILL BE IN
THE MID TO UPPER 20S. ANOTHER COLDER PERIOD WILL FOLLOW THE PASSAGE
OF A STRONG COLD FRONT TUE AFTERNOON/EVENING AND A SECONDARY COLD
FRONT TUE NIGHT/WED MORNING. 850MB TEMPS WILL DECREASE TO A MINIMUM
OF -25C TO -30C WED INTO WED NIGHT. THIS WILL RESULT IN TEMPS
FALLING INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO BY LATE WED
MORNING...THEN INCREASING TO THE SINGLE DIGITS ABOVE ZERO DURING
PEAK HEATING WED AFTERNOON. SFC HIGH PRESSURE WILL START TO WORK
INTO THE AREA FROM THE W WED NIGHT...WHICH SHOULD ALLOW FOR VERY
COLD TEMPERATURES UNDER THE LINGERING COLD AIRMASS WITH LOWS WED
NIGHT FALLING TO AROUND -20 ALONG THE WI BORDER IN GOGEBIC AND IRON
COUNTIES. TEMPERATURE MODERATION WILL THEN OCCUR FRI THROUGH THE
WEEKEND.
WITH LAKE SUPERIOR NEARLY COMPLETELY ICE COVERED...LES
COVERAGE/INTENSITY IS SIGNIFICANTLY REDUCED...BUT SCATTERED LIGHT
LES IS EXPECTED TUE NIGHT INTO THU IN NW WIND SNOWBELTS. BLOWING
SNOW WILL BE AN ISSUE ALONG LAKE SUPERIOR AS WNW WINDS INCREASE
BEHIND THE COLD FRONTS...WITH GUSTS UP TO 40MPH POSSIBLE ALONG THE
SHORE LATE TUE INTO WED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1240 PM EST MON MAR 2 2015
VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THIS AFTN/EVENING
UNDER DRY AIR MASS ASSOCIATED WITH HIGH PRES MOVING FROM THE MID
MISSISSIPPI VALLEY TO THE MID ATLANTIC STATES. LATE TONIGHT...SW
FLOW BTWN THE HIGH AND AN APPROACHING LOW PRES TROF WILL BRING A
RAPID INCREASE IN MOISTURE WHICH WILL LEAD TO SNOW DEVELOPMENT. AS
THE SNOW SPREADS NE...MVFR CONDITIONS SHOULD DEVELOP AT KIWD AROUND
09Z AND AT KCMX/KSAW AROUND 12Z. BY MID TO LATE MORNING...ALL
TERMINALS SHOULD SEE IFR CONDITIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EST MON MAR 2 2015
NW WINDS UP TO 30 KTS OVER EASTERN LAKE SUPERIOR EARLY WILL DIMINISH
QUICKLY THIS MORNING WITH ARRIVAL OF HI PRES RIDGE. LIGHT S WINDS
WILL THEN INCREASE UP TO 25 KTS ON TUE IN ADVANCE AN APPROACHING LO
PRES. ONCE THE LO PASSES TO THE E ON TUE NIGHT...TIGHTENING PRES
GRADIENT AND STRONG COLD AIR ADVECTION AHEAD OF ARCTIC HI PRES
MOVING INTO THE NORTHERN PLAINS WILL LIKELY BRING A PERIOD OF NW
GALES INTO WED. LATEST OFFICIAL ICE CONCENTRATION ON LK SUPERIOR IS
AROUND 95 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK...EXPECT
THE HIGHER ICE COVERAGE TO PERSIST AS TEMPERATURES STAY BELOW
FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING FOR
LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1255 PM EST MON MAR 2 2015
.SYNOPSIS...
A COLD FRONT WITH LIMITED MOISTURE WILL MOVE THROUGH THE AREA
TODAY. HIGH PRESSURE BEHIND THE FRONT WILL BUILD INTO THE AREA
FROM THE NORTH TONIGHT INTO TUESDAY. A WARM FRONT WILL MOVE NORTH
THROUGH THE AREA TUESDAY INTO TUESDAY NIGHT. A STRONG COLD FRONT
WILL MOVE THROUGH THE AREA THURSDAY. HIGH PRESSURE WILL BUILD INTO
THE REGION FROM THE NORTH FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1 PM MON...MUCH OF FORECAST AREA CLEAR WITH THE EXCEPTION
OF THE OUTER BANKS AND EVEN THERE SKIES WILL CLEAR SHORTLY. TEMPS
IN THE CLEAR AREA AT FORECAST HIGHS SO HAVE BUMPED UP AFTERNOON
HIGHS ANOTHER COUPLE OF DEGREES. NO OTHER CHANGES.
FOR TODAY...REINFORCING COLD FRONT WILL PUSH THROUGH E NC LATE
THIS MORNING/EARLY AFTERNOON. NOT MUCH FORCING OR MOISTURE
ASSOCIATED WITH THE FRONT THOUGH NOT ENOUGH CONFIDENCE TO REMOVE
THE INHERITED 20 POP FROM GRIDS. ANY ISOLATED SHOWERS WILL MOVE
OFFSHORE WITH THE FRONT AFTER AROUND NOON TODAY...FOLLOWED BY
PARTIAL CLEARING FROM NW TO SE AS COLUMN DRIES. BASED ON LOW LEVEL
THICKNESS VALS AND MO CLOUDY SKIES FOR A BETTER PART OF THE DAY...
SHOULD SEE HIGHS IN THE 50S (LOW 50S NE TO UPPER 50S SW).
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 330 AM MON...SKIES SHOULD BE MOSTLY CLEAR TO START THE
NIGHT AS TRANSITORY HIGH SCOOTS BY TO THE NORTH. MUCH DRIER AIR
MASS WILL FILTER INTO THE REGION WITH LIGHT WINDS...AND OVERNIGHT
LOWS WILL FALL WELL INTO THE 30S. TEMPS MAY BOTTOM OUT AROUND
MIDNIGHT BEFORE LEVELLING OFF AND THEN RISING TOWARDS DAYBREAK AS
INC ISENTROPIC LIFT OCCURS DUE TO WARMING ALOFT AND INC MID/HIGH
CLOUD COVER MOVES IN FROM THE SW.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...AN ACTIVE WEATHER PATTERN IS EXPECTED THIS
WEEK AS TRANSIENT SYSTEMS IN A SPLIT FLOW REGIME AFFECT THE
FORECAST AREA. LARGE SWINGS IN TEMPERATURE WILL BRING SPRINGLIKE
WARMTH DURING MIDWEEK FOLLOWED BY A CHANCE OF WINTRY PRECIP AND
COLD ON THURSDAY. THE UNSEASONABLY COLD TEMPERATURES WILL PREVAIL
THROUGH LATE IN THE WEEK.
HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTH INTO EARLY TUESDAY.
A WARM FRONT IS THEN FORECAST TO SLOWLY RETREAT TO THE NORTH
TUESDAY AFTERNOON AND EVENING. PATCHY TO PERHAPS WIDEPSREAD LIGHT
RAIN IS EXPECTED AS THE BOUNDARY TRAVERSES THE AREA INTO TUESDAY
EVENING. LATEST GUIDANCE SUGGESTS THAT PRECIPITATION HOLDS OFF
UNTIL SURFACE WARNS ABOVE FREEZING TUESDAY SO NOT EXPECTING ANY P
TYPE ISSUES ALTHOUGH THERE IS LIKELY TO BE A LARGE TEMPERATURE
GRADIENT ACROSS THE AREA AS THE WEDGE INLAND RETARDS THE FRONTAL
PROGRESS UNTIL EVENING. THUS THE IMMEDIATE COAST COULD MAKE INTO
THE 60S LATE WHILE DEEPER INLAND LOCATIONS REMAIN IN THE 40S. THE
WARM FRONT IS FORECAST TO FINALLY MOVE NORTH OF THE AREA TUESDAY
NIGHT AS THE WEDGE ERODES WITH TEMPERATURES LIKELY WARMING INTO
THE 60S THROUGHOUT THE AREA. THUS WILL NEED TO FORECAST A NON
DIURNAL TEMPERATURE CYCLE WITH TUESDAYS "HIGHS" LIKELY TO BE
TUESDAY NIGHTS "LOWS" AS THE WARM SECTOR SURGES NORTH ACROSS
EASTERN NC.
MODELS ARE IN GOOD AGREEMENT FOR UNSEASONABLY MILD TEMPERATURES (FOR
A CHANGE) ON WEDNESDAY WITH HIGHS INTO THE 70S AWAY FROM ANY
COOLING ONSHORE BREEZES. COULD SEE SEA FOG/STRATUS ALONG THE SOUTH
FACING COASTLINES WHICH COULD LIMIT TEMPERATURES. THE MODELS
CONTINUE TO TREND LATER WITH RAIN CHANCES TO LATE WEDNESDAY INTO
WED NIGHT AS AN ANA FRONT TYPE PRECIP REGIME SETS UP BEHIND THE
INCOMING SFC BNDRY.
THERE ARE LARGE DIFFERENCES IN THE MODELS REGARDING THE SPEED OF
A STRONG COLD FRONT WHICH WILL MOVE THROUGH THE AREA THURSDAY. THE
GFS IS CONSIDERED TOO FAST WITH THE FRONT MAKING IT TO THE CRYSTAL
COAST BY 12Z THURSDAY WHILE THE NAM IS CONSIDERED TOO SLOW WITH
THE FRONT STILL WEST OF THE COASTAL PLAIN AT THIS TIME. THE ECMWF
WAS THE COMPROMISE CHOICE WITH THE FRONT MOVING INTO THE NW ZONES
LATE WEDNESDAY NIGHT AND THEN THROUGH THE REMAINDER OF THE AREA
LATE THURSDAY MORNING. PRECIP CHANCES SHOULD INCREASE AS THE
FRONT MOVES THRU AND BRINGS THE NEXT ROUND OF ARCTIC AIR TO THE
REGION. THERMAL PROFILES FAVOR A CHANGEOVER TO FROZEN
PRECIPITATION FROM NORTH TO SOUTH DURING THURSDAY BEFORE ENDING
LATER THU AFTERNOON OR EVENING AND WILL CONTINUE A LOW CONFIDENCE
CHANCE OF SNOW AND SLEET. TOO EARLY TO GET INTO MUCH DETAIL ABOUT
POSSIBLE ACCUMULATIONS AS YET BUT PRECIP LOOKS TO BE MOVING THRU
QUICKLY WHICH WOULD LIMIT AMOUNTS.
PRECIP ENDS LATE THU/THU EVENING FROM NW TO SE, WITH STRONG HIGH
PRESSURE BUILDING EAST OVER THE REGION FROM THE TENNESSEE VALLEY
AREA INTO SATURDAY. THICKNESSES FALL QUICKLY BEHIND THE FRONT FRIDAY
WITH HIGHS ONLY EXPECTED IN THE 40S FRIDAY AND UPPER 40S TO LOWER
50S SATURDAY/SUNDAY. LOWS THU AND FRIDAY WILL DROP WELL INTO THE 20S.
THE FORECAST FOR LATE IN THE WEEKEND IS VERY UNCERTAIN WITH A
LARGE SPREAD IN THE GUIDANCE (GFS DRY/ECMWF WETTER). WILL
CONTINUE TO INDICATE DRY WEATHER SUNDAY UNTIL PERIOD COMES INTO
BETTER FOCUS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1020 AM SUN...VSBYS SLOWLY COMING UP BUT LIFR/IFR CIGS
PERSISTING. CONDITIONS LOOK TO SLOWLY IMPROVE THIS MORNING WITH
MVFR LATE MORNING THEN FINALLY VFR BY AROUND NOON. COLD FRONT WILL
MOVE THROUGH THE TERMINALS EARLY AFTERNOON WITH WINDS VEERING
NORTH 10KT POSSIBLY GUSTING A LITTLE HIGHER. MAINLY CLEAR SKIES
EARLY THIS EVENING WITH SCT/BKN HIGH CLOUDS AND LIGHT NE WINDS.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...DRIER AIR SPREADS INTO THE AREA WITH VFR
CONDITIONS EXPECTED INTO EARLY TUESDAY THEN A WARM FRONT WILL
RETREAT SLOWLY TO THE NORTH TUESDAY AFTERNOON AND EVENING WITH
POSSIBLY SOME LOWER FLIGHT CATEGORIES AS MOISTURE INCREASES OVER
THE AREA WITH PATCHY TO WIDESPREAD LIGHT RAIN EXPECTED. A COLD
FRONT WILL APPROACH FROM THE WEST WEDNESDAY NIGHT AS SURFACE FLOW
SHIFTS SOUTHWEST AND MAY BECOME GUSTY WEDNESDAY AFTERNOON WITH
ONLY WIDELY SCATTERED RAIN SHOWERS FORECAST. A STRONG COLD FRONT
WILL CROSS THE REGION LATE WED NIGHT AND MOVE OFFSHORE THU. GOOD
CVRG OF RAIN WED NIGHT AND EARLY THU WITH PRECIP DIMINISHING
LATE...POSS MIXED WITH SOME SNOW OR SLEET INLAND. SUB VFR
CONDITIONS ARE A GOOD BET LATER WED NIGHT AND MUCH OF THU. STRONG
HIGH PRESSURE BUILDS IN FOR A RETURN TO PREDOMINANT VFR CONDITIONS
LATE IN THE WEEK.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 7 AM MON. CURRENT OBS SHOWING SEAS 3 TO 5 FT WITH A WSW
WIND 10 TO 15 KT. MAINTAINING DENSE FOG ADVISORY THROUGH 10AM FOR
ALL WATERS AS VSBYS RANGING GENERALLY 1/2 TO 2 MILES. FOR
TODAY...THE WSW WINDS WILL BECOME NORTH THIS AFTERNOON AND INC
BEHIND A COLD FRONT. WE EXPECT A NORTHERLY SURGE THIS
AFTERNOON...AND RIGHT NOW ALL BUT ALBEMARLE SOUND AND THE RIVERS
SHOULD SEE SCA DEVELOPING. HRRR AND NSSL WRF INDICATE ENOUGH OF A
SURGE TO PRODUCE SCA WIND GUSTS EASTERN PAMLICO SOUND BEGINNING
AROUND 18Z. THE GUSTY WINDS WILL SLOWLY VEER NE AND DIMINISH
TONIGHT...WITH VARIOUS SCA HEADLINES ENDING AROUND 9Z AS SEAS TAKE
A BIT LONGER TO RESPOND TO DIMINISHING WINDS.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...STRONG WINDS AND ROUGH SEAS WILL PREVAIL
OVER THE MARINE AREA DURING THE PERIOD AS A SERIES OF WEATHER
SYSTEMS TRAVERSE THE WATERS. WINDS WILL BRIEFLY DIMINISH TUE MORN
THEN BEGIN TO RAMP UP FROM THE S LATE TUE AS A WARM FRONT LIFTS N
THRU THE AREA. SEAS WILL DIMINISH EARLY TUE THEN BUILD BACK UP TO
4 TO 6 FT BY TUE EVENING HIGHEST FAR OUTER CNTRL WTRS. GUSTY SSW
WINDS WILL DEVELOP TUE NIGHT AND CONT WED AHEAD OF APPROACHING
COLD FRONT...SEAS WILL BUILD TO 5 TO 9 FEET OUTER WTRS WED. THE
COLD FRONT WILL CROSS THE EASTERN NC COASTAL WATERS LATE WEDNESDAY
NIGHT/EARLY THU WITH STRONG HIGH PRESSURE BUILDING IN FROM THE
WEST THURSDAY, LEADING TO GUSTY N WINDS THU WITH SEAS OF 5 TO 9
FEET. WINDS/SEAS WILL SLOWLY DECREASE AS COLD AIR ADVECTION WANES
LATE FRIDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST TUESDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM EST
TUESDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR AMZ150.
&&
$$
SYNOPSIS...JME/TL
NEAR TERM...HSA/TL
SHORT TERM...TL
LONG TERM...JME/BTC
AVIATION...HSA/TL/JME
MARINE...HSA/TL/JME
AREA FORECAST DISCUSSION
NWS PENDLETON OR
230 PM PST MON MAR 2 2015
.SHORT TERM...TONIGHT THROUGH THURSDAY. THE TAIL END OF A BACKDOOR
COLD FRONT IS MAKING ITS WAY ACROSS EASTERN WASHINGTON AND NORTHEAST
OREGON. DOPPLER RADAR AT SPOKANE IS SHOWING A WIDE SWATH OF WEAK
RETURNS (LESS THAN 20 DBZ). LATEST HRRR KEEP REFLECTIVITIES THIS LOW
THROUGH EARLY TUESDAY MORNING WITH 12-HOUR QPF AMOUNTS LESS THAN A
TENTH OVER MOST OF THE AREA. THIS INCREASES CONFIDENCE THAT ANY
SNOWFALL TONIGHT WILL BE LIGHT AND MAINLY ISOLATED TO SCATTERED
OROGRAPHIC SHOWERS. THE ONE EXCEPTION WILL BE OVER THE WALLOWA
MOUNTAINS WHERE A NORTHERLY FLOW ALOFT AND MOISTURE WILL BRING 3-6
INCHES OF SNOW IN THE HIGHER TERRAIN. THE WALLOWA VALLEY...IMNAHA
VALLEY...AND THE NORTHERN PLATEAU OF WALLOWA COUNTY WILL LIKELY
RECEIVE 1-3 INCHES OVERNIGHT DUE TO THE 20:1 SNOW-TO-LIQUID RATIO
AND LOW LEVEL UPSLOPE. PRECIPITATION WILL TAPER OFF TONIGHT AND
EARLY TUESDAY MORNING. A DRY NORTHERLY FLOW ALOFT FOLLOWING THE
SYSTEM WILL CAUSE OVERNIGHT TEMPERATURES TONIGHT TO FALL INTO THE
TEENS AND 20S...AND SINGLE DIGITS AND TEENS TUESDAY NIGHT. IT WILL
BE BREEZY TONIGHT IN THE LOWER COLUMBIA BASIN RESULTING IN WIND
CHILLS IN THE TEENS. A FEW LOCATIONS MAY BEAT THEIR RECORD LOWS FOR
TUESDAY NIGHT.
A DRY FORECAST IS IN STORE TUESDAY AFTERNOON THROUGH THURSDAY. A
WARMING TREND BEGINS WEDNESDAY AS HIGH PRESSURE ALOFT BUILDS.
AFTERNOON TEMPERATURES WILL CLIMB INTO THE 50S ACROSS THE REGION ON
THURSDAY--ABOUT 5 DEGREES ABOVE SEASONAL AVERAGE. WISTER
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY. TOWARD THE END OF THE
WEEK A DISTURBANCE WILL PASS TO THE NORTH OF THE AREA AS STRONG HIGH
PRESSURE DOMINATES OUR WEATHER INTO THE WEEKEND WITH DRY CONDITIONS.
AFTERNOON TEMPERATURES ARE FORECAST TO CLIMB ABOVE NORMAL AND INTO
THE 60S ACROSS SOME LOCATIONS BY THE WEEKEND.
&&
.AVIATION...LCL MVFR CEILINGS WILL PERSIST INTO THIS EVENING AS A
DISTURBANCE MOVES THROUGH THE REGION. WNW SFC WINDS WILL SHIFT TO
THE NORTH THAT WILL USHER SOME COLDER AIR INTO THE REGION TONIGHT.
DECREASING CLOUDS WILL ACCOMPANY THE COLDER AIR AND A RETURN TO VFR
CONDITIONS ARE EXPECTED AFTER 02Z EXCEPT AFTER 06Z ALONG THE
FOOTHILLS OF THE BLUE MOUNTAINS THAT INCLUDES TAF SITES KPDT AND
KALW. THE VFR CONDITIONS WILL CONTINUE INTO TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 23 43 19 50 / 10 0 0 0
ALW 27 44 24 53 / 20 0 0 0
PSC 23 48 18 52 / 10 0 0 0
YKM 25 46 21 51 / 10 0 0 0
HRI 22 47 18 53 / 10 0 0 0
ELN 23 48 19 51 / 10 0 0 0
RDM 16 45 12 52 / 10 0 0 0
LGD 22 40 13 47 / 20 10 0 0
GCD 20 41 15 50 / 20 10 0 0
DLS 28 52 24 57 / 20 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
85/97/97
AREA FORECAST DISCUSSION
NWS PORTLAND OR
949 AM PST MON MAR 2 2015
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE ALONG THE SOUTH OREGON AND
NORTH CALIFORNIA COAST EARLY THIS MORNING WILL CONTINUE TO DROP SOUTH
TODAY. DRIER NORTH FLOW ALOFT WILL SETTLE OVER SW WASHINGTON AND NW
OREGON LATER TODAY. ANOTHER WEAK DISTURBANCE SLIDES SOUTH ALONG THE
EASTERN CASCADE SLOPES TONIGHT. HIGH PRESSURE WILL THEN DOMINATE THE
WEATHER PATTERN MID-WEEK THROUGH THE WEEKEND.
&&
.SHORT TERM...MORNING WATER VAPOR IMAGERY SHOWS AN SMALL AND COMPACT
UPPER LEVEL LOW DIVING SOUTH ALONG THE N CALIFORNIA COAST. INFRA-RED
IMAGERY INDICATES RAPID CLEARING ALONG THE WA AND N OREGON COAST AS
OF 17Z. KRTX DUAL-POL DOPPLER RADAR NOT SHOWING MUCH IN THE WAY OF
ANY APPRECIABLE ECHOES. THE LATEST HRRR RUN DEPICTS THESE TRENDS
WELL. CASCADE WEB CAMS ALSO SHOWING CLEARING SKIES. OVERALL QPF WITH
THE DEPARTING SYSTEM WAS RATHER ANEMIC...ALTHOUGH THE HOODOO SKI AREA
CAM SHOWS A DUSTING OF SNOW IN THE PARKING LOT. SKIES WILL CONTINUE
TO CLEAR NORTH TO SOUTH TODAY...ALTHOUGH THE INTERIOR VALLEYS WILL
TAKE LONGER DUE TO THE EXTENSIVE MID-CLOUD LAYER THAT EXISTS.
BRISK NLY FLOW ALOFT WILL BE OVER THE FORECAST AREA TONIGHT AND TUE.
THE LATEST NAM HINTS AT A WEAK BACK-DOOR SYSTEM SLIDING S ALONG THE
ERN CASCADE SLOPES TONIGHT WITH SOME VERY SPOTTY QPF ASSOCIATED WITH
IT. THE 00Z ECMWF ALSO SHOWED THIS FEATURE. WILL KEEP THE MINIMAL
POPS FOR THE HIGHER CASCADES TONIGHT...BUT NOT OVERLY CONFIDENT
ANYTHING WILL OCCUR. BIGGER STORY FOR TONIGHT WILL BE WIDESPREAD
FREEZING TEMPS. MAY ALSO SEE A LITTLE EAST WIND DEVELOP IN THE GORGE
LATE TONIGHT AS THE NAM SHOWS A -3 TO -4 KTTD-KDLS GRADIENT BY 12Z
TUE.
UPPER RIDGE WILL THEN BE THE DOMINANT FEATURE...AS IT HAS BEEN FOR
MOST THE WINTER. SOME LOW-LEVEL OFFSHORE FLOW PERSISTS THROUGH WED SO
NIGHT AND MORNING FOG WILL BE RATHER LOCALIZED. OVERNIGHT LOWS WILL
DROP TO NEAR OR BELOW FREEZING TUE NIGHT...WITH THE LATEST GUIDANCE
SHOWING LOWS IN THE MID TO UPPER 20S FOR MANY INLAND VALLEYS.
WEISHAAR
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
WEDNESDAY NIGHT THROUGH SUNDAY...THE MEAN UPPER RIDGE POSITION
LINGERS WHERE IT HAS BEEN MUCH OF THIS WINTER...OVER THE NE PACIFIC
AND ALONG THE WEST COAST. THIS SHOULD KEEP THE PACIFIC JET STREAM
WELL TO OUR NORTH...AS WELL AS ANY CHANCES OF SIGNIFICANT
PRECIPITATION. THEREFORE OUR FORECAST REMAINS DRY THROUGH NEXT
WEEKEND. CONDITIONS MAY BECOME INCREASINGLY FAVORABLE FOR FOG IN THE
VALLEYS...AS MOST GUIDANCE PUSHES THE UPPER RIDGE AXIS ONSHORE LATE
IN THE WEEK. OTHERWISE EXPECT A GRADUAL RETURN TO ABOVE NORMAL
TEMPERATURES WHICH MAY LAST INTO NEXT WEEKEND. WEAGLE
&&
.AVIATION...SOME AREAS OF IFR/MVFR LINGERING THIS MORNING AS LOW
PRESSURE DROPS SOUTHWARD ALONG THE OREGON COAST. EXPECT VFR ALL
AREAS BY 21Z AS CLOUDS LIFT/CLEAR...ASIDE FROM SOME SCT MTN
OBSCURATIONS. DRIER NORTHERLY FLOW WILL KEEP SKIES CLEAR TONIGHT
MOST AREAS...THOUGH SOME PATCHY FOG MAY FORM IN THE TYPICAL FOG-
PRONE VALLEYS. KEUG/KHIO MAY SEE SOME FOG/FREEZING FOG BY DAYBREAK
TUESDAY. TEMPS TONIGHT WILL LIKELY GET BELOW FREEZING IN MOST
OUTLYING VALLEYS.
KPDX AND APPROACHES...MAINLY VFR THROUGH TONIGHT. LIGHT-MODERATE
N-NW FLOW SFC AND ALOFT...DIMINISHING TONIGHT. SCATTERED LOWER
CLOUDS AROUND 1000-1500 FT THIS MORNING SHOULD LIFT/CLEAR OUT BY
20Z. WEAGLE
&&
.MARINE...WEAK LOW PRESSURE PRESENTLY JUST OFFSHORE OF NEWPORT
WILL CONTINUE TO PUSH SOUTHWARD TODAY...WITH NORTHERLY FLOW
INCREASING THIS AFTERNOON AS HIGH PRESSURE BUILDS INTO
WASHINGTON. WILL MAINTAIN SCA FOR WINDS IN OUR SOUTHERN WATERS
THROUGH THIS EVENING...AS WINDS MAY GUST UP TO 25 KT BEHIND THIS
SYSTEM. THE GUSTY N WINDS COMBINED WITH A LITTLE BIT OF SWELL WILL
CONTINUE TO WHIP UP STEEP SEAS IN OUR SOUTHERN WATERS...ESPECIALLY
OUTSIDE OF 30 NM OFFSHORE. WINDS DECREASE TONIGHT AS HIGH PRESSURE
BUILDS OVER THE REGION...TURNING LIGHT OFFSHORE. A THERMAL TROUGH
BUILDING NORTH FROM CA MAY CAUSE ANOTHER INCREASE IN N WINDS
MIDWEEK...MAINLY FOR OUR SOUTHERN WATERS. OTHERWISE A STRONG UPPER
LEVEL RIDGE WILL KEEP CONDITIONS BENIGN FOR THE REST OF THE
WEEK...AS THE PACIFIC STORM TRACK STAYS WELL TO OUR NORTH. WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 PM PST THIS EVENING FOR
COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
AFTERNOON FOR WATERS FROM CASCADE HEAD TO FLORENCE OR FROM
10 TO 60 NM.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEDFORD OR
931 AM PST MON MAR 2 2015
.UPDATE...
UPDATES HAVE BEEN MADE TO THE FORECAST FOR SKY COVERAGE,
PROBABILITIES OF PRECIPITATION, AND RESULTANT WEATHER FOR TODAY
THROUGH THIS EVENING. BTL
&&
.DISCUSSION...
AN UPPER LEVEL TROUGH IS SHEARING APART AS IT MOVES SOUTHEASTWARD
THROUGH THE AREA TODAY. COLD AIR ALOFT DID RESULT IN A FEW SNOW
SHOWERS ACROSS THE HIGHER RIDGES AND MOUNTAIN PEAKS EARLIER THIS
MORNING AND THERE HAVE BEEN A FEW HUNDREDTHS OF AN INCH OF RAIN
ALONG AND NEAR THE COAST, COASTAL MOUNTAINS, AND UMPQUA BASIN.
THIS UPPER LEVEL TROUGH WILL CONTINUE TO SHEAR TODAY WITH MOST OF
THE LOWER LEVEL MOISTURE ENDING UP WEST OF THE CASCADES WHILE THE
MID AND UPPER LEVEL MOISTURE WILL BE GREATEST AS ONE HEADS EAST
FROM THE CASCADES. THIS MEANS THAT CLOUDS ARE EXPECTED TO
INCREASE EXCEPT OVER THE SOUTHWESTERN-MOST PORTION OF THE AREA
TODAY AS SURFACE HEATING CAUSES SOME WEAK TO MODERATE INSTABILITY.
LIMITED MOISTURE AT THE VARIOUS KEY LEVELS THROUGH THE
TROPOSPHERE WILL RESULT IN MOSTLY JUST SOME LIGHT SHOWERS OVER
SOUTHEASTERN PORTIONS OF THE FORECAST AREA AND THE MOUNTAINS
THROUGH THIS AFTERNOON. WITH TEMPERATURES IN/NEAR THE DENDRITIC
GROWTH ZONE IN THE MOUNTAINS ABOVE 6KFT TODAY, IT WILL BE
POSSIBLE TO SEE SOME SNOW FLAKES WITH LITTLE OR NO APPARENT CLOUD
COVER. PRECIPITATION AMOUNTS WILL BE A TRACE TO A FEW HUNDREDTHS
WHERE IT DOES OCCUR. BTL
&&
.AVIATION...FOR THE 02/12Z TAF CYCLE...A FRONT WILL BRING LIGHT RAIN
TO THE COAST AND WESTERN UMPQUA THIS MORNING ALONG WITH MVFR CIGS
AND LCL IFR CIGS. THE FRONT WILL BRING CLOUDS AND SPOTTY RAIN TO
OTHER AREAS OF THE WEST SIDE, BUT CONDITIONS ELSEWHERE ARE EXPECTED
TO REMAIN VFR THROUGH MONDAY. /FB
&&
.MARINE...UPDATED 230 AM PST, MONDAY, 2 MAR, 2015...HIGH CONFIDENCE
EXISTS THAT AREAS OF MODERATE NORTHERLY WINDS WILL PERSIST THROUGH
WEDNESDAY AND WILL BE STRONGEST DURING THE AFTERNOONS AND EVENINGS
BEYOND 5 NM AND SOUTH OF CAPE BLANCO. A DISTURBANCE ALOFT WILL BRING
LIGHT RAIN TO THE AREA THIS MORNING. THE PATTERN OF A THERMAL TROUGH
AT THE COAST AND HIGH PRESSURE OFFSHORE WILL DEVELOP AGAIN TUESDAY
WITH NORTHERLY CHOP. WINDS ARE EXPECTED TO WEAKEN LATE IN THE WEEK
AS THE HIGH BUILDS EASTWARD. /FB
&&
.PREV DISCUSSION... /ISSUED 305 AM PST MON MAR 2 2015/
DISCUSSION...A WEAK SHORTWAVE WILL QUICKLY MOVE SOUTH ALONG THE
OREGON COAST THIS MORNING. SO FAR MEASURABLE RAINFALL HAS BEEN
CONFINED TO THE COAST. RADAR SHOWS RETURNS INLAND OVER
JOSEPHINE...WESTERN JACKSON AND SISKIYOU COUNTY, BUT DEWPOINTS
STILL REMAIN LOW, SO SUSPECT LITTLE IF ANYTHING IS REACHING THE
GROUND. THE RAP KEEPS MOST OF THE PRECIPITATION OFFSHORE, BUT IT
DOES SHOW SOME QPF WEST OF THE CASCADES. THE HRRR RADAR REFLECTIVITY
ALSO SHOWS LIGHT RETURNS IN THE SAME AREAS, BUT SUSPECT IT`S
SUGGESTING VIRGA. THEREFORE WE`LL CONTINUE TO KEEP THE HIGHEST
POPS OVER THE WATERS AND COAST WITH A SLIGHT CHANCE FURTHER INLAND
IN DOUGLAS...JOSEPHINE AND WESTERN JACKSON COUNTY.
THE SHORTWAVE WILL MOVE SOUTH LATE THIS MORNING WITH DRY
CONDITIONS EXPECTED MOST LOCATIONS THE REST OF THE DAY. A FEW
SHOWERS ARE POSSIBLE FOR THE CASCADES AND SISKIYOUS IN THE
AFTERNOON WITH LITTLE IF ANY QPF.
THE MODELS ARE IN GOOD AGREEMENT ADVERTISING A DRY AND MILD
PATTERN FOR THE REST OF THE WEEK THROUGH NEXT WEEKEND. AN UPPER
RIDGE NEAR 140 W WILL SHIFT EAST AND STRENGTHEN THE LATTER PART OF
THE WEEK INTO NEXT WEEKEND. GUIDANCE SUGGEST TEMPERATURES IN
MEDFORD COULD GET NEAR 70 DEGREES WHICH IS ABOUT 14 DEGREES ABOVE
CLIMO. IT`S POSSIBLE IT COULD HAPPEN WITH TEMPERATURES WARMING
ALOFT. MODELS SHOW 850 MB TEMPERATURES WARMING FRIDAY INTO NEXT
WEEKEND WITH THE GFS SHOWING TEMPERATURES NEAR 12C SATURDAY...13C
SUNDAY AND NEXT MONDAY. -PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...
- SMALL CRAFT ADVISORY FOR WINDS FROM 4 PM THIS AFTERNOON TO 1 AM
PST TUESDAY FOR PZZ356.
- SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST THIS
EVENING FOR PZZ350-356.
- SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST THIS EVENING FOR
PZZ370.
- SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST TUESDAY
FOR PZZ370-376.
- HAZARDOUS SEAS WARNING UNTIL 10 PM PST THIS EVENING FOR PZZ370-376.
- SMALL CRAFT ADVISORY FOR WINDS UNTIL 1 AM PST TUESDAY FOR
PZZ376.
$$
BTL/MAP/FB
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
327 PM CST MON MAR 2 2015
.DISCUSSION...
A LONG WAVE TROUGH EXTENDS FROM THE HUDSON BAY VORTEX
SOUTHWESTWARD INTO THE DESERT SOUTHWEST WHERE IT WILL REMAIN
ANCHORED FOR A FEW DAYS WHILE THE REST OF THE TROUGH MOVES EAST.
THE TROUGH IS POSITIVELY TILTED AND WILL KICK A SURFACE CYCLONE
ACROSS THE CENTRAL PLAINS ON TUESDAY AND SEND ANOTHER STRONG COLD
FRONT THROUGH NORTH AND CENTRAL TEXAS.
WINDS WILL VEER OVERNIGHT AS LOW PRESSURE DEEPENS IN THE LEE OF
THE ROCKIES. A WARM FRONT NEAR THE TEXAS COAST WILL BEGIN MOVING
NORTH WITH LOCAL WINDS VEERING SOUTHEAST. THE RETURN OF LOW LEVEL
WARM ADVECTION WILL RESULT IN SCATTERED LIGHT RAIN...AREAS OF FOG
OVERNIGHT AND TEMPERATURES HOLDING NEAR STEADY OR SLOWLY WARMING
TONIGHT.
TUESDAY WILL BE MUCH WARMER AND BREEZY BUT SKIES SHOULD REMAIN
MOSTLY CLOUDY. SCATTERED SHOWERS ARE EXPECTED AREA WIDE MOST OF
THE DAY. INSTABILITY FOR THUNDERSTORMS WILL BE BEST OVER THE
NORTHEAST COUNTIES DURING THE AFTERNOON. INSTABILITY WILL WEAKEN
IN THE EVENING...THUS THUNDERSTORM ACTIVITY WILL BECOME MORE
ISOLATED OVERNIGHT AS THE COLD FRONT MOVES ACROSS THE RED RIVER
SHORTLY AFTER MIDNIGHT.
WE FEEL THE NAM SERIES IS TOO SLOW WITH WEDNESDAYS COLD FRONT AND
HAVE SIDED WITH THE GFS/ECMWF MODEL SOLUTIONS FOR THIS FORECAST.
THE FRONT WILL WORK THROUGH THE CWA WEDNESDAY MORNING WITH
TEMPERATURES HOLDING STEADY OR SLOWLY FALLING ONCE IT PASSES AND
STRONG NORTH WINDS THE REST OF THE DAY. LIFT ALONG THE FRONT AND
FORCING FOR ASCENT FROM ABOVE WILL KEEP SHOWERS/RAIN GOING MOST OF
THE DAY. AS THE DEPTH OF THE COLD DEEPENS...RAIN WILL TRANSITION
TO A WINTRY MIX OF FREEZING RAIN AND SLEET...THEN TO ALL SLEET.
THERE MAY BE SOME SNOW MIXED IT AS THE PRECIPITATION STARTS TO
END...BUT IT SHOULD NOT BE THE PREDOMINANT PRECIPITATION TYPE FOR
THIS EVENT. WE EXPECT THIS TRANSITION TO BEGIN ALONG THE RED RIVER
AROUND MID MORNING WEDNESDAY...ACROSS THE METROPLEX SHORTLY AFTER
MIDDAY AND AROUND WACO/KILLEEN/PALESTINE BY SUNSET.
THE MAIN AREA OF OUR CONCERN IS THE SOUTHEAST PORTION OF THE
CWA...GENERALLY SOUTHEAST OF A COMANCHE TO CANTON LINE WITH FOCUS
ON WACO/KILLEEN TO ATHENS/PALESTINE...WHERE WE THINK SLEET COULD
ACCUMULATE UP TO 1/2 INCH AND FREEZING RAIN UP TO 1/10 INCH. THIS
IS DUE TO A STRONG FRONTOGENESIS SIGNATURE AROUND 700MB AND THE
RIGHT- REAR ENTRANCE REGION OF A 200 KNOT UPPER JET OVER THIS
REGION. WE WILL BE ISSUING A SPECIAL STATEMENT WITH THIS PACKAGE
TO HIGHLIGHT THE POTENTIAL FOR SLEET/ICE TO CAUSE HAZARDOUS
IMPACTS WEDNESDAY NIGHT INTO THURSDAY. THIS IS AN EVOLVING SYSTEM
AND THE ACTUAL LOCATION AND MAGNITUDE OF THE SLEET AND ICE WILL
LIKELY CHANGE SOME AS NEW DATA IS RECEIVED.
AS FOR THE METROPLEX...ONCE TEMPERATURES FALL TO FREEZING OR
BELOW...PRECIPITATION WOULD BEGIN TO ACCUMULATE ON MIX-MASTERS..
OVERPASSES AND BRIDGES...FOLLOWED BY ROADWAYS SHORTLY AFTERWARD.
THE INTENSITY OF THE SLEET AND DURATION WILL GOVERN HOW FAST
IMPACTS DEVELOP DURING THE AFTERNOON/EVENING COMMUTE. IF AROUND
ONE-TENTH OR MORE OF SLEET ACCUMULATES BY DARK...THEN IMPACTS
WOULD LAST THROUGH THE THURSDAY MORNING COMMUTE.
THE PRECIPITATION WILL BE ENDING OVER THE SOUTHEAST COUNTIES BY
MIDDAY THURSDAY. OTHERWISE...IT WILL REMAIN DRY AND COLD INTO
FRIDAY. THE COLD AIR WILL MOVE EAST LATE FRIDAY WITH WINDS
RETURNING TO THE SOUTH. THIS WILL BRING WARMER TEMPERATURES FOR
THE WEEKEND AND A SLIGHT CHANCE OF RAIN OVER THE SOUTHEAST
COUNTIES. ANOTHER UPPER TROUGH MAY PASS ACROSS THE REGION ON
SUNDAY WHICH COULD BRING SLIGHTLY COOLER TEMPERATURES FOR SUNDAY
AND MONDAY. 75
&&
.AVIATION...
/ISSUED 1225 PM CST MON MAR 2 2015/
FOR THE 18Z TAFS...THE DURATION OF IFR CIGS AND VSBYS IS THE
PRIMARY FORECAST CONCERN.
CLOUD HEIGHTS WERE GENERALLY RANGING FROM 3 TO 5 HUNDRED FEET
ABOVE GROUND LEVEL ACROSS NORTH TEXAS AT NOON/18Z. HRRR FORECAST
SOUNDINGS INDICATE SHALLOW LIFT WILL PERSIST IN THE LOWEST FEW
THOUSAND FEET OF THE ATMOSPHERE TODAY...WHICH DOES NOT BODE WELL
FOR THE PROSPECTS OF HAVING CLOUD HEIGHTS CLIMB MUCH THROUGHOUT THE
DAY TODAY. DESPITE THE CLOUD COVER...THERE IS STILL SOME HEATING
AT THE SURFACE. DESPITE PERSISTENT NORTHEASTERLY WINDS AT THE
SURFACE...THERE IS NO STRONG COLD AIR ADVECTION...SO THINK
TEMPERATURES WILL RISE TO AROUND 40 DEGREES OR JUST ABOVE FOR
TODAY`S HIGH. HOWEVER...RECENT WIDESPREAD SNOW/SLEET MELT ACROSS
THE DFW AREA HAS LEFT THE GROUND VERY DAMP. CURRENT THINKING IS
THAT ANY INCREASE IN TEMPERATURE WILL BE MET WITH AN INCREASE IN
DEW POINT DUE TO EVAPORATION KEEPING CEILING HEIGHTS MORE OR LESS
STEADY THROUGHOUT THE DAYLIGHT HOURS TODAY.
FOR TONIGHT...THINK THAT CLOUD HEIGHTS AND VISIBILITIES WILL TEND
TO REMAIN STABLE. A STRONG LOW-LEVEL JET IS EXPECTED TO DEVELOP BY
EARLY TOMORROW MORNING WHICH SHOULD START TO PROVIDE ENOUGH LOW-
LEVEL WARM AIR ADVECTION TO LOWER THE NEAR SURFACE STABILITY
PROFILES A BIT. EVEN IF WE MAINTAIN SOME INVERSION...A SMALLER
DEPTH OF THE INVERSION COMBINED WITH THE STRONGER WINDS ALOFT
SHOULD PROMOTE SOME BETTER MIXING THAT RESULTS IN AN INCREASE IN
CLOUD HEIGHTS TOWARDS 1000 FEET AGL. WENT WITH A FEW HOURS OF
LOW-LEVEL WIND SHEAR IN THE TAFS TOMORROW MORNING TO ACCOUNT FOR
THE LOW-LEVEL JET...AND THEN SLOWLY IMPROVED CIGS THROUGHOUT THE
DAY ON TUESDAY.
WHAT TO WATCH FOR...AS DEW POINTS CLIMB ON THE NOSE OF THE LOW-
LEVEL JET AND WARM AIR INCREASES IN INTENSITY...THERE IS SOME
POTENTIAL FOR ADVECTION FOG IF NEAR SURFACE WINDS CAN REMAIN
DECOUPLED FROM THE INFLUENCE OF THE LOW-LEVEL JET. CONFIDENCE IN
THIS WAS NOT HIGH ENOUGH TO BRING VISIBILITIES DOWN TO ONE HALF
MILE OR BELOW TOMORROW MORNING WITH THE ONSET OF THE STRONGER WARM
AIR ADVECTION...HOWEVER THIS IS SOMETHING WE`LL BE WATCHING
CLOSELY OVER THE NEXT 12-18 HOURS. CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 40 65 39 39 27 / 40 40 60 80 50
WACO, TX 42 69 48 48 28 / 30 30 50 80 70
PARIS, TX 39 63 38 40 24 / 40 60 60 80 60
DENTON, TX 39 65 35 37 25 / 40 40 60 70 50
MCKINNEY, TX 40 64 37 38 25 / 40 50 60 80 50
DALLAS, TX 41 67 40 41 27 / 40 40 60 80 50
TERRELL, TX 41 67 42 43 27 / 40 50 60 80 60
CORSICANA, TX 43 68 46 47 28 / 40 40 60 80 70
TEMPLE, TX 42 68 50 50 28 / 30 30 40 70 70
MINERAL WELLS, TX 39 69 35 37 26 / 30 30 60 60 50
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/75
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1225 PM CST MON MAR 2 2015
.AVIATION...
FOR THE 18Z TAFS...THE DURATION OF IFR CIGS AND VSBYS IS THE
PRIMARY FORECAST CONCERN.
CLOUD HEIGHTS WERE GENERALLY RANGING FROM 3 TO 5 HUNDRED FEET
ABOVE GROUND LEVEL ACROSS NORTH TEXAS AT NOON/18Z. HRRR FORECAST
SOUNDINGS INDICATE SHALLOW LIFT WILL PERSIST IN THE LOWEST FEW
THOUSAND FEET OF THE ATMOSPHERE TODAY...WHICH DOES NOT BODE WELL
FOR THE PROSPECTS OF HAVING CLOUD HEIGHTS CLIMB MUCH THROUGHOUT THE
DAY TODAY. DESPITE THE CLOUD COVER...THERE IS STILL SOME HEATING
AT THE SURFACE. DESPITE PERSISTENT NORTHEASTERLY WINDS AT THE
SURFACE...THERE IS NO STRONG COLD AIR ADVECTION...SO THINK
TEMPERATURES WILL RISE TO AROUND 40 DEGREES OR JUST ABOVE FOR
TODAY`S HIGH. HOWEVER...RECENT WIDESPREAD SNOW/SLEET MELT ACROSS
THE DFW AREA HAS LEFT THE GROUND VERY DAMP. CURRENT THINKING IS
THAT ANY INCREASE IN TEMPERATURE WILL BE MET WITH AN INCREASE IN
DEW POINT DUE TO EVAPORATION KEEPING CEILING HEIGHTS MORE OR LESS
STEADY THROUGHOUT THE DAYLIGHT HOURS TODAY.
FOR TONIGHT...THINK THAT CLOUD HEIGHTS AND VISIBILITIES WILL TEND
TO REMAIN STABLE. A STRONG LOW-LEVEL JET IS EXPECTED TO DEVELOP BY
EARLY TOMORROW MORNING WHICH SHOULD START TO PROVIDE ENOUGH LOW-
LEVEL WARM AIR ADVECTION TO LOWER THE NEAR SURFACE STABILITY
PROFILES A BIT. EVEN IF WE MAINTAIN SOME INVERSION...A SMALLER
DEPTH OF THE INVERSION COMBINED WITH THE STRONGER WINDS ALOFT
SHOULD PROMOTE SOME BETTER MIXING THAT RESULTS IN AN INCREASE IN
CLOUD HEIGHTS TOWARDS 1000 FEET AGL. WENT WITH A FEW HOURS OF
LOW-LEVEL WIND SHEAR IN THE TAFS TOMORROW MORNING TO ACCOUNT FOR
THE LOW-LEVEL JET...AND THEN SLOWLY IMPROVED CIGS THROUGHOUT THE
DAY ON TUESDAY.
WHAT TO WATCH FOR...AS DEW POINTS CLIMB ON THE NOSE OF THE LOW-
LEVEL JET AND WARM AIR INCREASES IN INTENSITY...THERE IS SOME
POTENTIAL FOR ADVECTION FOG IF NEAR SURFACE WINDS CAN REMAIN
DECOUPLED FROM THE INFLUENCE OF THE LOW-LEVEL JET. CONFIDENCE IN
THIS WAS NOT HIGH ENOUGH TO BRING VISIBILITIES DOWN TO ONE HALF
MILE OR BELOW TOMORROW MORNING WITH THE ONSET OF THE STRONGER WARM
AIR ADVECTION...HOWEVER THIS IS SOMETHING WE`LL BE WATCHING
CLOSELY OVER THE NEXT 12-18 HOURS.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 1131 AM CST MON MAR 2 2015/
MORNING KFWD SOUNDING SHOWS THE SWALLOW ARCTIC AIR CONTINUING TO
MODIFY SLOWLY OVERNIGHT WITH A SHARPE INVERSION NOW AROUND 1200
FEET AND AROUND 50 DEGREES (10C) AT 850 MB (5000 FEET). AS A
RESULT OUR LOW CLOUDS WILL HANG IN TODAY WITH HIGH TEMPERATURES
ONLY 5 TO 9 DEGREES ABOVE THE MORNING LOWS. COOLEST HIGHS WILL BE
OVER THE NORTHWEST COUNTIES WHERE SNOWFALL WAS HEAVIEST. AS WINDS
VEER EAST AND SOUTHEAST OVERNIGHT...WE WILL SEE DEWPOINTS BEGIN TO
RISE AS A WARM FRONT NEARS FROM THE SOUTH. WE WILL LIKELY SEE FOG
ACROSS MOST OF THE CWA TONIGHT.
FIRST LOOK AT THE MORNING MODELS DO NOT SHOW ANY MAJOR CHANGES
NEEDED. WE/LL BE WORKING ON WEDNESDAY AFTERNOON THROUGH THURSDAY
MORNING PRECIP TYPE AND AMOUNTS FOR THE AFTERNOON PACKAGE. 75
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 40 65 39 39 27 / 40 40 60 70 50
WACO, TX 42 69 48 48 28 / 30 30 50 70 60
PARIS, TX 39 63 38 40 24 / 40 60 60 70 60
DENTON, TX 39 65 35 37 25 / 40 40 60 60 50
MCKINNEY, TX 40 64 37 38 25 / 40 50 60 70 50
DALLAS, TX 41 67 40 41 27 / 40 40 60 70 50
TERRELL, TX 41 67 42 43 27 / 40 50 60 70 60
CORSICANA, TX 43 68 46 47 28 / 40 40 60 70 60
TEMPLE, TX 42 68 50 50 28 / 30 30 40 70 60
MINERAL WELLS, TX 39 69 35 37 26 / 30 30 60 60 50
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/